bluuebunny/crossref_metadata_2025 huggingface dataset:
Characterization of Electron-Beam-Induced Silver Deposition from Liquid Phase
Authors: Park Jonathan J. , Joshi-Imre Alexandra , Ocola Leonidas E. , Divan Ralu
Published: January 2012

Electron-beam-induced deposition (EBID) using gas-phase precursor molecules is an extensively studied fabrication technique. Liquid-phase metal deposition has recently been shown to achieve higher purity levels than traditional gas-phase deposition [1]. The goal of this investigation was to characterize liquid-phase silver deposition for further studies in photonics. A Scanning Electron Microscope (SEM) (FEI Nova 600 NanoLab Dual Beam) was used to deposit silver on polyimide membranes from aqueous AgNO3 solution by accelerating electrons into the solution for silver ion reduction. Atomic Force Microscopy (AFM) and SEM were subsequently used to characterize the size dependence to electron dosage. We observed granular silver deposits with sub-75 nm particle size and 200-250 nm total aggregate diameters. The CASINO (monte CArlo SImulation of electroN trajectory in sOlids) program was used to model electron trajectory in the solution to relate the size to the electron spread.
Influence of Oxide Nanoparticles of Fe, Al and Si on the Sintered Magnesia for the Production of Refractory Material to Be Used in Secondary Ladle Metallurgy
Authors: Gómez Cristian , Das Tushar.K. , Shaji Sadasivan , Rodríguez Edén A. , Guzmán Ana M. , Castillo Alan , García Laura
Published: January 2012

Iron oxide (Fe2O3, 20-40 nm), aluminum oxide (Al2O3, 50 nm) and silicon oxide (SiO2, 20-60 nm) nanoparticles were mixed in different concentrations (1 to 5 wt %) in a magnesium oxide matrix to develop new refractory matrixes as candidates in the lining of secondary ladle metallurgy. To avoid agglomeration of nanoparticles in the magnesium oxide (MgO) matrix, it was carried out a dispersion method of nanoparticles with different dispersants. After that, the powder mixture was sintered at a temperature of 1300 and 1500 °C for 4 hours. The refractory samples obtained were studied using X-ray diffraction (XRD) and scanning electron microscopy with energy dispersive X-ray spectrometer (SEM-with EDX) and also measured their density and porosity. The results showed that the samples sintered at 1500 °C with 5 wt % of Fe2O3 reached the highest density and presented the MgFe2O4 spinel-type phase. With the addition of Al2O3-nanoparticles in the MgO matrix, there were the formation of MgAl2O4 spinel phase and in the case of SiO2-nanoparticles addition it was observed the formation of Mg2SiO4 forsterite phase. It is well known that with the increase in spinel phase in the matrix, there is a significant help to retain quantities of ions of iron and nickel due to the dissolution of the slag into the refractory material extending their lining life.
Effect of Organoclay’s characteristics during the preparation of complex ternary system PP-EP/EVA/Organoclay.
Authors: Yeraldin Olivares M. , Eduardo Ramírez V. , Saúl Sánchez V.
Published: January 2012

In this work, the effect of structural characteristics of organomodified clays on the dispersion degree, mechanical and rheological properties of the nanocomposites PP-EP/EVA/nanoclay has been studied. The studied effects were: degree of chemical modification of the clay, length of substitute groups on the surfactant, and the steric effect caused by surfactant structure. The characterization techniques used were Wide Angle X-ray Diffraction (WAXD), Scanning Transmission Electron Microscopy (STEM), Dynamic Mechanical Analysis (DMA), Tensile Test and Capillary Rheometry. Cloisite 6A, 15A and 20A were used to evaluate the first effect. Better intercalation-exfoliation and mechanical properties were obtained when the clay with lower content of surfactant was used (C20A), these results were attributed to a higher saturation of the system. In order to study the second effect, Cloisite 20A and Cloisite 25A were employed. It was found that the bigger initial intergallery space between these nanoclay’s caused by the longer chains in Cloisite 20A, allows the formation of a structure with better intercalated-exfoliated structure. This was confirmed with the observed increase in mechanical properties. Finally, the third effect was studied with Cloisite 10A and 15A. It was clearly seen that only with Cloisite 15A was possible to obtain an intercalated-exfoliated structure. This was attributed to a major steric effect when using C10A than with 15A.
Effect of Titania Grafting on Behavior of NiMo HDS Catalysts Supported on Nanostructured Silica Materials
Authors: Mendoza-Nieto A. , Puente-Lee I. , Salcedo-Luna C. , Klimova T.
Published: January 2012

In the present work, a comparison study of the NiMo hydrodesulfurization (HDS) catalysts supported on different nanostructured supports of MCM-41 and SBA-15-types and the same ones modified by TiO2 grafting was undertaken. The aim of this study was to inquire on the effect of the characteristics of the primary silica supports on the activity and selectivity of the NiMo catalysts modified with titania in deep HDS. Supports and catalysts were characterized by nitrogen physisorption, small-angle and powder XRD, TPR, UV-vis DRS, and HRTEM, and tested in the simultaneous HDS of dibenzothiophene (DBT) and 4,6-dimethyldibenzothiophene (4,6-DMDBT). It was found that titania grafting on all silica supports resulted in a slight decrease of BET surface area and total pore volume. However, the characteristic p6mm hexagonal pore arrangement of the used nanostructured silica materials was not affected. Powder X-ray diffraction pointed out a good dispersion of Mo and Ni oxide species in all prepared catalysts. TPR characterization of the NiMo catalysts revealed some increase in the metal-support interaction after titania grafting on the silica surface. Further DRS characterization indicated that the best dispersion of Mo oxide species was obtained on the TiSBA-15 support. Titania addition to the silica supports also produced an increase in the dispersion of the sulfided NiMo phase, which was more marked for SBA-15 support than for the MCM-41 (HRTEM). The most active NiMo/Ti-SBA-15 catalyst resulted to be significantly more active (∼40 %) than the conventional NiMo/γ-Al2O3 catalyst in HDS of 4,6-DMDBT.
Theoretical Study of Alkanedithiolated Gold Clusters
Authors: Cabrera-Trujillo J. M. , Jiménez-Cataño R.
Published: January 2012

A reactive molecular dynamics simulation study on the structure, energetics, and chemistry of alkanethiolated gold cluster is presented. Through very recent reactive molecular dynamics force-fields developed by Järvi et al. [1], chemical reactions of alkanedithiolates and star-like shape gold nanoparticles are studied throughout octanedithiolates and stellated cuboctahedral gold clusters models [2] at room temperature. Structure, energetics, reactants, and some products of the reactions are preliminarily analyzed up to 25 ps. In general, preliminary results of this work are in agreement with those reported in the review by Love et al. [3].
Recreation as an ecosystem service in open landscapes in the Mediterranean region in Israel: Public preferences
Authors: Koniak Gili , Sheffer Efrat , Noy-Meir Imanuel
Published: January 2012

In recent years awareness has increased of the importance of open landscapes (natural and semi-natural) for human use, including provision of life-supporting ecological benefits and services. In addition there has been an increase in awareness and demand for recreational activities in nature: cultural, social, sport, and spiritual activities outside of the urban setting. A partial list of all of the environmental benefits or services could add up to dozens of economical, biological, and social benefits. Social benefits such as recreation are just one component of the spectrum of benefits and services that can be derived from natural systems.

In this research we assessed the ecosystem service of recreation in a natural setting in the Mediterranean region in Israel. We focused on two specific benefits: picnics and hikes. We assessed recreationers' preferences using questionnaire-based surveys that were carried out directly at the research site, Ramat Hanadiv Park (RH park), while people were conducting the particular activity (picnic or hike). The research aim was to estimate the preferences of hikers and picnickers for different types of natural vegetation formations. We found that visitors preferred to hike in the open garrigue compared to either the dense scrub or the pine forest, whereas for picnics both the open garrigue and the planted pine forest were preferred over the dense scrub. We tested the attractiveness of each component of the landscape (e.g., trees, flowers, animals, archaeology) for hikers and picnickers. Surveys showed that scenery was highly and unanimously ranked. Flowering plants, birds, native trees, and to some extent gazelles, deer, and butterflies were ranked high, while reptiles, beetles, and cattle received a much lower attractiveness rank. The ranking of archeological sites and pine forest was more variable, and intermediate to the two main groups above. We analyzed these preferences according to different age and population distributions of visitors to the park and found only slight effects of the level of education.

The answers from this research can facilitate land managers and decision-makers in providing the ecosystem service of recreation, and to guide management for obtaining the desired vegetation formations for this aim, according to the preferences of hikers and picnickers.
States and transitions: The trajectory of an idea, 1970-2010
Authors: Walker Brian , Westoby Mark
Published: January 2012

State-and-transition language for ecosystem dynamics was articulated in a 1989 paper written by Imanuel Noy-Meir in collaboration with Westoby and Walker. That paper has been surprisingly influential considering that the publication it appeared in,Journal of Range Management, serves a relatively small community of researchers. Here we trace the wider history within which the paper sits, both the context that led up to its being written and its influence subsequently. Our aim is to explain Noy-Meir's distinctive and constructive role, at several points in the history.
Anxiety and depressive symptoms in clinically isolated syndrome and multiple sclerosis
Authors: Anhoque Carolina Fiorin , Domingues Simone Cristina Aires , Carvalho Thiago , Teixeira Antônio Lúcio , Domingues Renan Barros
Published: January 2012

Depression and anxiety have been reported in patients with multiple sclerosis (MS) and in patients with clinically isolated syndrome (CIS). However, the precise mechanisms that lead to depressive and anxiety symptoms in these patients are still unclear. In this study we evaluated with the Beck Depression Inventory (BDI) and the Beck Anxiety Inventory (BAI) patients with MS and CIS and compared them to controls. We also correlated BDI and BAI scores with clinical parameters. Kruskall-Wallis followed by Dunn's Multiple Comparison Test, Chi-square and Spearman test were used. Patients with MS had higher depressive and anxiety scores than controls. The BDI and BAI scores of patients with CIS were not significantly different from controls. There was a positive correlation between BDI, BAI and EDSS. Our results corroborate the view that MS patients have higher depression and anxiety levels than control subjects. Anxiety and depressive symptoms also seem to progress according to the severity of the disease.
Uma re-análise dos resultados do PISA: problemas de comparabilidade
Authors: Klein Ruben
Published: January 2012

Neste artigo apresenta-se um problema de comparabilidade de resultados entre aplicações do Pisa, em alguns países, em diversos anos e entre países. Esse problema ocorre porque a idade escolar de cada país não é considerada e porque não há uma regra para a data de aplicação da prova em relação aos anos letivos de cada país. A mudança de data da aplicação em um país modifica a composição do alunado entre as séries, tornando os universos não comparáveis. Analisa-se com detalhes o caso do Brasil e mostra-se que os universos de 2000 e 2009 não são comparáveis. Analisa-se também alguns outros países, entre eles Luxemburgo e Chile, que, juntos com o Brasil, foram destacados como tendo a maior evolução de desempenho desde 2000. Em Luxemburgo, não houve melhoria de desempenho de 2003 para 2009 e é preciso investigar porque os resultados de 2000 e 2003 são tão diferentes. O Chile apresenta melhoria de desempenho, mas provavelmente não tão grande quanto o apontado.
Do evergreen and deciduous trees have different effects on net N mineralization in soil?
Authors: Mueller Kevin E. , Hobbie Sarah E. , Oleksyn Jacek , Reich Peter B. , Eissenstat David M.
Published: January 2012

Evergreen and deciduous plants are widely expected to have different impacts on soil nitrogen (N) availability because of differences in leaf litter chemistry and ensuing effects on net N mineralization (Nmin). We evaluated this hypothesis by compiling published data on net Nmin rates beneath co‐occurring stands of evergreen and deciduous trees. The compiled data included 35 sets of co‐occurring stands in temperate and boreal forests. Evergreen and deciduous stands did not have consistently divergent effects on net Nmin rates; net Nmin beneath deciduous trees was higher when comparing natural stands (19 contrasts), but equivalent to evergreens in plantations (16 contrasts). We also compared net Nmin rates beneath pairs of co‐occurring genera. Most pairs of genera did not differ consistently, i.e., tree species from one genus had higher net Nmin at some sites and lower net Nmin at other sites. Moreover, several common deciduous genera (Acer, Betula, Populus) and deciduous Quercus spp. did not typically have higher net Nmin rates than common evergreen genera (Pinus, Picea). There are several reasons why tree effects on net Nmin are poorly predicted by leaf habit and phylogeny. For example, the amount of N mineralized from decomposing leaves might be less than the amount of N mineralized from organic matter pools that are less affected by leaf litter traits, such as dead roots and soil organic matter. Also, effects of plant traits and plant groups on net Nmin probably depend on site‐specific factors such as stand age and soil type.
BEHAVIOR‐BASED ASSESSMENT OF THE AUDITORY ABILITIES OF BRUSHTAIL POSSUMS
Authors: Osugi Mizuho , Foster T. Mary , Temple William , Poling Alan
Published: January 2012

Brushtail possums (Trichosurus vulpecula) were trained to press a right lever when a tone was presented (a tone‐on trial) and a left lever when a tone was not presented (a tone‐off trial) to gain access to food. During training the tone was set at 80 dB(A), with a frequency of 0.88 kH for 3 possums and of 4 kH for the other 2. Once accuracy was over 90% correct across five consecutive sessions, a test session was conducted where the intensity of the tone was reduced by 8 dB(A) over blocks of 20 trials until accuracy over a block fell below 60%. After each test session, training sessions were reintroduced and continued until accuracy was again over 90%, when another test session was conducted. This process continued until there were at least five test sessions at that tone frequency. The same procedure was then used with frequencies of 0.20, 0.88, 2, 4, 10, 12.5, 15, 20, 30, and 35 kHz. Percentage correct and d' decreased approximately linearly for all possums as tone intensity reduced. Both sets of lines were shallowest at the higher frequencies and steepest at the lower frequencies. Hit and false alarm rates mirrored each other at high frequencies but were asymmetric at lower frequencies. Equal d' contours showed that sensitivity increased from 2 to 15 kHz and continued to be high over 20 to 35 kHz. The possums remained sensitive to the 20 to 35 kHz tones even at low intensities. The present study is the first to report the abilities of possum to detect tones over this range of frequencies and its results support the findings of a microelectrode mapping survey of possums' auditory cortex.
Anaerobic and Aerobic Transformations Affecting Stability of Dewatered Sludge during Long‐Term Storage in a Lagoon
Authors: Lukicheva Irina , Tian Guanglong , Cox Albert , Granato Thomas , Pagilla Krishna
Published: January 2012

The goal of this work was to study long‐term behavior of anaerobically digested and dewatered sludge (biosolids) in a lagoon under anaerobic and aerobic conditions to determine the stability of the final product as an indicator of its odor potential. Field lagoons were sampled to estimate spatial and temporal variations in the physical‐chemical properties and biological stability characteristics such as volatile solids content, accumulated oxygen uptake, and soluble protein content and odorous compound assessment. The analyses of collected data suggest that the surface layer of the lagoon (depth of above 0.15 m) undergoes long‐term aerobic oxidation resulting in a higher degree of stabilization in the final product. The subsurface layers (depth 0.15 m below the surface and deeper) are subjected to an anaerobic environment where the conditions favor the initial rapid organic matter degradation within approximately the first year, followed by slow degradation.
HIV and the Bloodborne Pathogen Regulation: implications for the wastewater industry
Authors: Johnson Richard W. , Blatchley Ernest R. , Mason Dana R.
Published: January 2012

ABSTRACT:  The Occupational Safety and Health Administration (OSHA) requires all employers to develop protocols to minimize occupational exposure to bloodborne pathogens and, in the case that occupational exposure cannot be eliminated, to inform their employees of any risk that bloodborne pathogens may present. Compared to most bloodborne pathogens, little information is available on the potential for occupational transmission of HIV from wastewater. To assess this potential, current information relative to human immunodeficiency virus (HIV) physiology, behavior, and analytical methods are reviewed. Information regarding the concentration of HIV in human waste and the survivability of HIV outside the human body is presented relative to the potential for virus transmission. From this information, it appears that the probability of such transmission approaches zero, but it cannot be ruled out entirely. It is more likely that human contact with wastewater will result in the transmission of pathogenic microorganisms other than HIV. Practices which limit or eliminate the risk of occupational transmission of “conventional” pathogens (namely, those practices prescribed under the Bloodborne Pathogen Regulation and the Universal Precautions of the Centers for Disease Control) will probably be effective in limiting HIV transmission from wastewater.
Solvent washing of PCP contaminated soils with anaerobic treatment of wash fluids
Authors: Khodadoust Amid P. , Wagner Julie A. , Suidan Makram T. , Safferman Steven I.
Published: January 2012

ABSTRACT:  A solvent washing procedure for the removal of pentachlorophenol (PCP) from contaminated soils is presented. This procedure can be used in both in‐situ and above‐ground soil washing applications. The in‐situ solvent washing (flushing) of soil was simulated by continuously flushing solvent through a packed bed of soil until the effluent PCP concentrations decrease to below the detection limit. The aboveground (ex‐situ) soil washing was simulated by batch tests (reverse isotherms) conducted on PCP contaminated soil. Acetone was found to be less effective than ethanol in flushing PCP from contaminated soil. Soil solvent flushing was evaluated for 20 × 40, 60 × 80, and 100 × 140 U.S. Mesh size soil fractions loaded with 100 ppm of PCP. The flushing solvent, 95% ethanol, was applied at three different flow rates. Lower solvent flow rates were more effective, for the same solvent throughput, than higher flow rates in extracting PCP thus suggesting that desorption kinetics was rate limiting. The 20 × 40 U.S. Mesh soil was flushed with various ethanol and water mixtures; the 75% ethanol solution removed more PCP than other mixtures. Batch extraction tests, conducted on 20 × 40, 100 × 140 U.S. Mesh size soil and the clay fraction of the same soil, revealed that 50% and 75% ethanol and water solutions consistently removed the highest amounts of PCP. The wash fluids were fed to an expanded‐bed anaerobic granular activated carbon (GAC) bioreactor, where the PCP content of the wash fluid was biodegraded and the ethanol served as the primary substrate.
Probabilistic approach to initial dilution of ocean outfalls
Authors: Huang Hening , Proni John R. , Tsai John J.
Published: January 2012

ABSTRACT:  This paper presents a probabilistic approach to develop initial dilution criteria or standards for ocean outfall design and environmental impact assessment of effluent discharges. In contrast to a currently used worst case approach, in which a particular combination of parameters affecting initial dilution is specified and an associated initial dilution is calculated using a deterministic dilution model, the probabilistic approach provides a framework for combining data for the parameters which are often available in the form of time series or described in statistics. The result of the probabilistic approach is a description of initial dilution as a function of cumulative or exceedance probability, from which the exposure risk level for the marine environment can be estimated and criteria or standards can be defined. The proposed methodology basically consists of implementing a probabilistic method with a deterministic initial dilution model. The probabilistic method could be time domain simulation, Monte Carlo simulation, or first‐order uncertainty analysis; while the deterministic initial dilution model could be a mathematical model, a physical model, or an empirical equation. A case study is presented of the Miami‐Central Outfall on the east coast of South Florida to compare the probabilistic approach with the worst case approach. In this case study, time domain simulation using actual data sets was employed to generate a time series of initial dilution (dilutions were calculated using a semi‐empirical equation). Some statistics of initial dilution were then obtained from the simulated dilution time series. For this case study, the worst case dilution is 17.3 (minimum surface or near‐surface dilution) and the associated cumulative probability is 5.4%.
Behavior of sewage effluent oil and grease in the ocean
Authors: Schulz T. J. , Marczan P. J. , Fane A. G.
Published: January 2012

ABSTRACT:  This paper describes a laboratory and field study of the behavior of sewage oil and grease after discharge to an ocean environment. The laboratory program was used to study the factors affecting coagulation and to determine if discharge through an ocean outfall enhances coagulation leading to an increase in concentration of floatable material on the ocean surface. A field study was conducted at Burwood Beach near Newcastle on the New South Wales coast to quantify the amount of oil and grease reaching the ocean surface from the outfall, to measure the size of particles of grease on the surface near the outfall, and to determine the conditions that lead to the formation of visible slicks and observable floatable material for an outfall discharging primary treated sewage.
Cleaning of excavated soil contaminated with hazardous organic compounds by washing
Authors: Rajput Vijay S. , Higgins Andrew J. , Singley Mark E.
Published: January 2012

ABSTRACT:  Bench‐scale experiments were conducted to investigate the effectiveness of an extraction and washing technique for the cleanup of contaminated soil using surfactants. The organics studied as model contaminants were 1,2,4‐trichlorobenzene (TCB), aniline, phenol, and 2,4‐dichlorophenol (DCP). A sandy loam was used as a model field soil. The results demonstrated the effectiveness of the extraction and washing process for decontamination of the sandy loam soil. As much as 99% of the organic contaminants studied were removed by the process depending upon the compound and the number of washes and rinses. The hydrophilic compounds—aniline, DCP, and phenol—were removed effectively from the soil by washing with deionized water alone. Surfactant washing had no advantage over water washing for these compounds. For the removal of TCB, a combination of washing with surfactant and rinsing with water was required. Alum coagulation was effective in separating clay and colloidal particles from the wash liquid but a relatively high alum dose was required and was observed to enhance adsorption of the contaminants on the clay particles. A small residual contaminant concentration remained in the soil.
Evaluation of four different tertiary filtration plants for turbidity control
Authors: Kuo Jih‐Fen , Chen Ching‐lin , Stahl James F. , Horvath Robert W.
Published: January 2012

ABSTRACT:  The County Sanitation Districts of Los Angeles County operate 10 water reclamation plants (WRPs) for wastewater reclamation and reuse. To comply with State of California's stringent wastewater reclamation criteria, tertiary filtration systems are required at seven of these WRPs. Four types of filters, including mono‐medium gravity (activated carbon or anthracite coal), dual‐media gravity, and dual‐media pressure filters, are used. A study has been conducted to evaluate and to compare the filters' performance. The study started with evaluating turbidity and suspended solids (SS) removal by using plant operational data. Ratios of SS to turbidity were determined and found comparable among the plants. Although all filters provide good turbidity control, removal efficiencies are different among the filtration systems. Some plausible explanations for the apparent differences in removal are provided. Particle size distribution (PSD) measurements were made on samples from various locations at the WRPs to provide insights into particle removal. Typical particle size and volume distributions in the wastewater streams were established. Although turbidity and PSD could not be well correlated, particle removals by the four filtration systems were determined for better understanding of their removal mechanisms.
A filtration technique for algal removal from lagoon effluents
Authors: Truax Dennis D. , Shindala Adnan
Published: January 2012

ABSTRACT:  As part of a comprehensive evaluation of posttreatment techniques for algal removal from lagoon effluents, intermittent sand filtration was evaluated. The main objective of the study was to delineate the filtration process most feasible for upgrading lagoons and to identify optimum design and operating parameters. Experimental procedures were conducted at the site of Starkville, Mississippi's 6.1‐hectare (15‐acre) lagoon. Studies utilized a full‐scale sonic microstrainer supplied by FMC Corporation and pilot‐sized rapid and intermittent sand filters. Microstraining was characterized by low specific flow rates and poor effluent quality. Rapid sand filters were unable to produce desirable effluent quality in conjunction with a sufficient filter run length. Intermittent sand filters were capable of consistently producing an effluent quality comparable to those expected from more complex advanced waste treatment processes. Optimum media gradation and hydraulic loading for the intermittent sand filters were determined. This paper presents the results of the intermittent sand filter studies.
The lateral‐flow sand‐filter system for septic‐tank effluent treatment
Authors: Check G. G. , Waller D. H. , Lee S. A. , Pask D. A. , Mooers J. D.
Published: January 2012

ABSTRACT:  The lateral‐flow sand filter (LFSF) is an alternative system for household septic‐tank effluent treatment that utilizes periodic or continuous surface discharge. The purpose of this study was to document the LFSF system, evaluate its treatment capabilities in laboratory models, and optimize design parameters. Three 5.0‐meter‐long laboratory models, each with a different permeability sand fill, were dosed with septic‐tank effluent for six months. After an initial development period, percentage removals for biochemical oxygen demand (BOD), total organic carbon (TOC), suspended solids, and coliform bacteria from all the models were excellent. Orthophosphate initially was attenuated but showed increasing values after a few months. Recommendations are made as to a suitable permeability range of sand fills to use in the LFSF system, adequate depth of sand fill and overall system dimensions. Laboratory modeling shows that the LFSF system is capable of providing a high level of treatment to household wastewater and that it should be suitable as a remedial or alternative system for household wastewater disposal.
Reaction of iodomethyltin(IV) compounds with (2s)-2,5-dihydro-3,6-dimethoxy-2-isopropylpyrazine
Authors: Dölling Karin
Published: January 2012

Following the Sch?llkopf methodology the reaction of (2S)-2,5-
dihydro-3,6-dimethoxy-2-isopropylpyrazine 1 with iodomethyl trimethylstannane
gives (2S,5S)-2,5-dihydro-3,6-dimethoxy-5-trimethylstannylmethyl-2-
isopropylpyrazine 2 in good yields. The obtained compound was characterized
with elemental analysis and multinuclear (1H, 13C and 119Sn) NMR
spectroscopy.
Corporate Social Performance, Innovation Intensity, and Financial Performance: Evidence from Lending Decisions
Authors: Guiral Andrés
Published: January 2012

This study examines how loan requests for intensifying corporate social performance (CSP) activities and loan requests for increasing innovation intensity affect loan officers' credit judgments and lending decisions. In addition, the impact of a balanced loan request for both CSP and innovation intensity was examined. An experiment was designed by manipulating the purpose of a loan request from a pharmaceutical company in order to create four alternative lending scenarios: (1) a full loan request for intensifying CSP activities; (2) a full loan request for increasing innovation intensity; (3) a loan request for a balanced investment in both CSP and innovation; and (4) a general purpose loan request (control group). The findings support that CSP investment is interpreted by loan officers as an indicator of superior corporate financial performance. However, no clear positive relationship between innovation intensity and lending decisions was found. These results are consistent with the view that lenders could be reluctant to fund innovation intensity initiatives because there may be a considerable time lag between this investment and its payoff. Contrary to expectations, a balanced loan request for both CSP and innovation was not interpreted by loan officers as the most favorable lending scenario for an innovative firm.
Comments by the Auditing Standards Committee of the Auditing Section of the American Accounting Association on the PCAOB Rulemaking Docket Matter 029: PCAOB Release No. 2011-007, Improving Transparency Through Disclosure of Engagement Partner and Certain Other Participants in Audits
Authors: Jones Keith L. , Aier Jagadison K. , Brandon Duane M. , Carpenter Tina D. , Caster Paul , Lisic Ling Lei , Pevzner Mikhail B.
Published: January 2012

In October 2011, the Public Company Accounting Oversight Board (PCAOB or Board) issued a release to solicit public comment on amendments to its standards that would improve the transparency of pubic company audits. The objective of the release was to solicit public comments on a proposed standard that would (1) require registered public accounting firms to disclose the name of the engagement partner in the audit report, (2) amend the Board's Annual Report Form to require registered firms to disclose the name of the engagement partner for each audit report already required to be reported on the form, and (3) require disclosure in the audit report of other independent public accounting firms and other persons that took part in the audit. The PCAOB provided for a 91-day exposure period (from October 11, 2011, to January 9, 2012) for interested parties to examine the release and provide comments. The Auditing Standards Committee of the Auditing Section of the American Accounting Association provided the comments in the letter below to the PCAOB on PCAOB Rulemaking Docket Matter 029: PCAOB Release No. 2011-007, Improving Transparency Through Disclosure of Engagement Partner and Certain Other Participants in Audits.

Data Availability: Information about and access to the release is available at: http://pcaobus.org/Rules/Rulemaking/Docket029/PCAOB_Release_2011-007.pdf
What Makes a “Complete Street” Complete?
Authors: Kingsbury Kevin T. , Lowry Michael B. , Dixon Michael P.
Published: January 2012

The concept of “complete streets” has gained momentum as a way to make communities more livable. This study presented a novel way to assess completeness, given context and public input. The approach was to use a four-dimensional audit for automobiles, transit users, bicyclists, and pedestrians. Although other assessment methods are intended to evaluate operational performance, this study proposed an audit-based assessment method as a valuable addition for planning purposes. Audit results were plotted on four axes to depict a provision profile to compare the balance between the modes. The most significant innovation was a framework to calculate a completeness score according to a community's vision for that particular street. Advantages of the framework were demonstrated through a case study in which 67 streets were assessed in a small, rural community. A review of the results revealed that some streets, as the result of the community-defined context, received completeness scores that were better than expected. Public volunteers provided critical input in the case study, and their role is explained in this paper.
Anticipation of Land use Change through use of Geographically Weighted Regression Models for Discrete Response
Authors: Wang Yiyi , Kockelman Kara M. , Wang Xiaokun (Cara)
Published: January 2012

Geographically weighted regression (GWR) enjoys wide application in regional science, thanks to its relatively straightforward formulation and explicit treatment of spatial effects. The application of GWR to discrete-response data sets and land use change at the level of urban parcels has remained a novelty, however. This paper describes work that combined logit specifications with GWR techniques to anticipate five categories of land use change in Austin, Texas, and controlled for parcel geometry, slope, regional accessibility, local population density, and distances to Austin's downtown and various roadway types. Results of this multinomial logit GWR model suggested spatial variations in—and significant influence of—these covariates, especially roadway vicinity and regional access. A 1% increase in the distance of an undeveloped parcel to the nearest freeway, for example, was estimated, on average, to increase the probability of residential development by 1.2%, while the same increase in distance to a major arterial was estimated to increase the probability by 1.8%. Conversely, proximity to roads (through reductions in such distances) was estimated to boost the likelihood of nonresidential development (e.g., 9.0% in the case of commercial development in response to a 1% decrease in distance to such arterials). The logsum accessibility index was estimated to exert an average positive influence on commercial, office, and industrial development tendencies, while it dampened land use transitions from an undeveloped state to residential uses. Comparisons of results with a spatial autoregressive binary probit (with the use of all developed land use categories as a single response) and GWR binary probit also provided some insights. The latter seemed to surpass the former in its account for spatial effects, as reflected by a lower Akaike information criterion value.
Analysis of House Prices to Assess Economic Impacts of New Public Transport Infrastructure
Authors: Dorantes Lucia Mejia , Paez Antonio , Vassallo Jose Manuel
Published: January 2012

Transportation infrastructure is known to affect the value of real estate property by virtue of changes in accessibility. The impact of transportation facilities is highly localized as well, and it is possible that spillover effects result from the capitalization of accessibility. The objective of this study was to review the theoretical background related to spatial hedonic models and the opportunities that they provided to evaluate the effect of new transportation infrastructure. An empirical case study is presented: the Madrid Metro Line 12, known as Metrosur, in the region of Madrid, Spain. The effect of proximity to metro stations on housing prices was evaluated. The analysis took into account a host of variables, including structure, location, and neighborhood and made use of three modeling approaches: linear regression estimation with ordinary least squares, spatial error, and spatial lag. The results indicated that better accessibility to Metrosur stations had a positive impact on real estate values and that the effect was marked in cases in which a house was for sale. The results also showed the presence of submarkets, which were well defined by geographic boundaries, and transport fares, which implied that the economic benefits differed across municipalities.
Modeling of Effects of Peak Load Pricing on Metropolitan Network and Activities
Authors: Pan Qisheng , Gordon Peter , Moore James , Richardson Harry W.
Published: January 2012

Peak load pricing has long been seen as a way to internalize externalities, as a set of incentives to shift peak hour trips to off-peak periods, and as a mechanism to generate revenues. However, how travelers trade time for money and respond to peak–off-peak pricing differentials is an open question that generates some timely and related questions, including the following: (a) How can the activity location and traffic implications for multiple times of the day in a major metropolitan area be modeled? (b) What are the network effects of peak load pricing on selected routes on level of service and urban development? It is possible to conduct simulations on actual highway networks to treat these questions. None of the urban models, however, can examine simultaneous route choice and time-of-day choice involving millions of travelers, thousands of traffic network zones, and hundreds of thousands of network links in an equilibrium system. This research addressed these questions by extending the Southern California Planning Model so that it could be used to determine the effects of pricing schemes on the time-of-day choice for travel, trip distribution, and network traffic for the greater Los Angeles, California (five-county), metropolitan area. The model estimated improvements in levels of service throughout the highway network for alternative toll charges. The model examined how drivers traded route choice with time-of-day choice against the option of traveling less. The approach also estimated the revenues implied for local jurisdictions as well as the possible effects of altered development pressures on land use throughout the region. The effects of two different toll scenarios were compared, and policy implications were offered.
Cross-Entropy Optimization Model for Population Synthesis in Activity-Based Microsimulation Models
Authors: Lee Der-Horng , Fu Yingfei
Published: January 2012

Microsimulation techniques for disaggregate activity-based travel demand models are expected to synthesize a desired number of fully specified individual activity patterns. A data prerequisite for this technique is the so-called synthetic population, a key input for activity-generating procedures. The iterative proportional fitting method has been widely used to estimate the multiway demographic tables for different geographic areas. This study proposed a cross-entropy optimization model in which generalized constraints for different demographic characteristics of the synthetic population could be included. A quasi-Newton algorithm was devised to solve the proposed problem. Encouraging results obtained from the model application suggested that the proposed method held much promise for generating a more realistic synthetic population with different types of demographic characteristics and could be generally applied in different geographic areas.
Joint Model of Vehicle Type Choice and Tour Length
Authors: Konduri Karthik C. , Ye Xin , Sana Bhargava , Pendyala Ram M.
Published: January 2012

Tour-based microsimulation model systems are increasingly being applied to the forecasting of travel demand. This paper examines the relationship between two dimensions of tours: the type of vehicle (in a household that owns multiple vehicles of different types) chosen to undertake the tour and the overall length (distance traveled) of the tour. These two dimensions are of much interest in the current planning context, in which concerns about energy sustainability and greenhouse gas emissions are motivating planners to seek ways to mitigate the adverse impacts of automotive travel. Moreover, virtually all tour-based models currently used do not explicitly account for choice of vehicle type in the modeling of tour attributes, despite the critical importance of the choice of vehicle type for energy and emissions analysis. This paper presents a joint discrete–continuous model of choice of vehicle type and length of tours. Estimation results suggested that significant common unobserved factors affected vehicle type choice and length of tours. These factors justified the use of modeling approaches with joint simultaneous equations to model tour attributes. The model specification in which vehicle type choice affected tour length performed better than the specification in which tour length affected vehicle type choice. This outcome suggested that choice of vehicle type (and allocation to household members) was a longer-term choice that influenced shorter-term tour-length choices.
Modeling of Job Mobility and Location Choice Decisions
Authors: Habib Muhammad Ahsanul , Miller Eric J. , Mans Bruce T.
Published: January 2012

This paper presents a comprehensive framework for modeling continuous decisions about changing jobs that individuals make over the course of their lives. The key objective of the research was to develop disaggregate econometric models for decision making about job mobility and location choice to implement longitudinal job mobility behavior of people within a dynamic microsimulation-based integrated urban modeling system. The paper includes two behavioral model components: (a) a job mobility model and (b) a job location choice model. The models were implemented empirically with a retrospective survey of the greater Toronto and Hamilton area in Ontario, Canada. The first component investigated the timing of job mobility with the use of a competing risk duration modeling approach for four event types: a job switch, a return to school, short-term unemployment, and withdrawal from the labor force. The second component, job location choice, was empirically estimated by applying the discrete choice methodology. One of the key features of the model was that it examined the influence of current employment in making decisions about the next job location and specified a gain–loss utility structure by the prospect–theoretic, reference-dependent choice modeling approach. A mixed logit model was developed to account for unobserved heterogeneity in the location preferences. These models were expected to be implemented in the Integrated Land Use, Transportation, Environment (ILUTE) modeling system, which had recently been updated with comparable disaggregate behavioral residential location models.
Change in Land use through Microsimulation of Market Dynamics
Authors: Zhou Bin (Brenda) , Kockelman Kara M.
Published: January 2012

Various land use models are now available, but a market-based model with sufficient spatial resolution and defensible behavioral foundations remains elusive. The model system developed in the study described here emphasized the interactions of individual market agents (on both the demand and the supply sides) and enjoyed behavioral foundations for each of the key actors at the level of parcels. Auction (or competition between market agents) was used to simulate price adjustment, and market-clearing prices were endogenously determined by iterative adjustment of the bidding prices for residential and commercial properties. A series of models for households, firms, and land developers and owners was estimated with actual data from Austin, Texas. The estimation results revealed tangible behavioral foundations for the evolution of urban land uses. The model forecasts demonstrated the strengths and limitations of this market simulation approach. Although equilibrium prices in forecast years were generally lower than those that were observed or expected, the spatial distributions of property values, new development, and individual agents were reasonable.
Investigation of Parking Dwell Time at Rest Areas on Rural Highways
Authors: Al-Kaisy Ahmed , Church Brian , Veneziano David , Dorrington Christopher
Published: January 2012

Highway rest areas provide several functions for travelers, including a chance to use the restroom, walk around, stop for a meal, sleep for a while, or pause to use a cellular phone. These activities directly influence dwell time, that is, the time that the traveler in a vehicle spends using a rest area. According to the activity performed at the rest area, the duration of dwell time varies from short to long. Existing information and guidance on parking dwell times at rest areas are generally outdated and are inconsistent among sources. A study was conducted by collecting and analyzing dwell time data from three rest areas in Montana: two located along Interstate highways and one located at the intersection of two state highways. The results showed that the mean dwell time at the three study sites ranged from 14 min 15 s to 23 min 20 s. When dwell times were examined by vehicle type, heavy vehicles had the greatest mean dwell time, followed by recreational vehicles and then cars. Examination of mean dwell times for short- and long-term parking found the short-term means to vary from 8 min 37 s to 10 min 26 s and the long-term means to vary from 4 h 41 min to 5 h 26 min. When data were separated by day and night, average dwell times during the day were significantly shorter than those during the night. This paper updates estimates for rest area dwell times to better represent the current practice and provides a better understanding of the variables that could affect dwell times.