bluuebunny/crossref_metadata_2025_split huggingface dataset:
A digital elevation analysis: a spatially distributed flow apportioning algorithm
Authors: Kim Sanghyun , Lee Haksu 
Published: May 2004

AbstractAn integrated flow determination algorithm is proposed to calculate the spatial distribution of the topographic index to the channel network. The advantages of a single flow direction algorithm and other multiple flow direction schemes are selectively considered in order to address the drawbacks of existing algorithms. A spatially varying flow apportioning factor is introduced to distribute the contributing area from upslope cells to downslope cells. The channel initiation threshold concept is expanded and integrated into a spatially distributed flow apportioning algorithm to delineate a realistic channel network. The functional relationships between the flow apportioning factors and the expanded channel initiation threshold (ECIT) are developed to address the spatially varied flow distribution patterns considering the permanent channel locations. A genetic algorithm (GA) is integrated into the spatially distributed flow apportioning algorithm (SDFAA) with the objective function of river cell evaluation. An application of a field example suggests that the spatially distributed flow apportioning scheme provides several advantages over the existing approaches; the advantages include the relaxation of overdissipation problems near channel cells, the connectivity feature of river cells and the robustness of the parameter determination procedure over existing algorithms. Copyright © 2004 John Wiley & Sons, Ltd.
Observations on the movement of coarse gravel using implanted motion‐sensing radio transmitters
Authors: McNamara James P , Borden Carter 
Published: May 2004

AbstractMotion‐sensing radio transmitters were implanted in cobbles (72–92 mm diameter) and placed in a stream in south‐west Idaho for 43 days during a snowmelt period. The radios transmit different pulse rates depending on whether the rocks are at rest or in motion. Every 30 s, a datalogger samples the receiver and records the pulse rate of the transmitters. Such information can be used to assess numerous properties of particle transport that are beyond the capabilities of conventional tracking methods. Conclusions include: (i) rocks are more likely to move on rising hydrograph limbs than on falling hydrograph limbs; (ii) the average Shields' parameter is 0·046; (iii) rocks move only a fraction of the time between initial and final motion during an event; (iv) the distributions of motion and rest periods are best modeled by gamma functions rather than exponential, but the distributions approach exponential as the tails are trimmed. Copyright © 2004 John Wiley & Sons, Ltd.
Hydrological responses to conservation practices in a catchment of the Loess Plateau, China
Authors: Huang Mingbin , Zhang Lu 
Published: May 2004

AbstractSince the late 1950s a series of soil conservation practices have been implemented in the Loess Plateau. It is important to assess the impact of these practices on hydrology at the catchment scale. The Jialuhe River catchment, a tributary of the Yellow River, with a drainage area of 1117 km2 in the Loess Plateau, was chosen to investigate the hydrological responses to conservation practices. Parametric and non‐parametric Mann–Kendall tests were utilized to detect trends in hydrological variables or their residuals. Relationships between precipitation and hydrological variables were developed to remove the impact of precipitation variability. Significant linear decreasing trends in annual surface runoff and baseflow were identified during the treated period from 1967 to 1989, and the rate of reduction was 1·30 and 0·48 mm/year, respectively. As result, mean annual surface runoff and baseflow decreased by 32% over the period of 1967 to 1989. Seasonal runoff also decreased during the treated period with the greatest reduction occurring in summer and the smallest reduction in winter. The response of high and low daily flow to conservation practices was greater than average flows. Copyright © 2004 John Wiley & Sons, Ltd.
Displacement and transport of marked pebbles, cobbles and boulders during floods in a steep mountain stream
Authors: Lenzi Mario Aristide 
Published: May 2004

AbstractIn a small experimental catchment of the Dolomites (Rio Cordon, 5 km2) field observations have been carried out on the movement of various sized bed material particles. Displacement length of 860 marked pebbles, cobbles and boulders (0·032 < D < 0·512 m) has been measured along the river bed during individual snowmelt and flood events in the periods 1993–1994 and 1996–1998. Floods were grouped into two categories. The first includes ‘ordinary’ events, which are characterized by peak discharges with a return period of 1–5 years and by an hourly bedload rate not exceeding 20 m3 h−1. The second refers to ‘exceptional’ events with a return period of 50–60 years. A flood of this latter type occurred on 14 September 1994, with a peak discharge of 10·4 m3 s−1 and average hourly bedload rate of 324 m3 h−1. The variation according to grain size of total displacement length Li depends on the degree of mobilization of the individual fractions of the bed surface: Li is independent of Di for smaller, fully mobile grain sizes and decreases rapidly with Di for larger fractions in a state of partial transport. Sustained selective transport without a supply of sediment from upstream leads to the development of a stable coarse armoured surface through progressive winnowing of finer material from the bed surface. With supply unlimited conditions for transport, both the occurrence of extreme events and the duration of a sequences of ‘ordinary’ floods play an important role in the degree of mobilization of the individual fractions of the bed. Copyright © 2004 John Wiley & Sons, Ltd.
Estimating river discharge from very high‐resolution satellite data: a case study in the Yangtze River, China
Authors: Xu Kaiqin , Zhang Jiqun , Watanabe Masataka , Sun Chunpeng 
Published: May 2004

AbstractThe measurement of river discharge is necessary for understanding many water‐related issues. Traditionally, river discharge is estimated by measuring water stage and converting the measurement to discharge by using a stage–discharge rating curve. Our proposed method for the first time couples the measurement of water‐surface width with river width–stage and stage–discharge rating curves by using very high‐resolution satellite data. We used it to estimate the discharge in the Yangtze (Changjiang) River as a case study. The discharges estimated at four stations from five QuickBird‐2 images matched the ground observation data very well, demonstrating that the proposed approach can be regarded as ancillary to traditional field measurement methods or other remote methods to estimate river discharge. Copyright © 2004 John Wiley & Sons, Ltd.
Long‐term carbon storage and hydrological control of CO2 exchange in tundra ponds in the Hudson Bay Lowland
Authors: Macrae M. L. , Bello R. L. , Molot L. A. 
Published: May 2004

AbstractCarbon dioxide fluxes and water balance were examined in 43 tundra ponds in the northern portion of the Hudson Bay Lowland near Churchill, Manitoba. Most of the ponds were hydrologically disconnected from their catchments during dry periods throughout the post‐melt season. However, episodic reconnection occurred following large precipitation events where depression storage was exceeded. Significant shifts in pond chemistry were observed following precipitation events, with the degree of CO2 saturation increasing during these periods. Pond CO2 concentrations rapidly fell to pre‐event levels following events, suggesting that hydrological connectivity can affect the magnitude and direction of CO2 gas fluxes in tundra ponds. Atmospheric CO2 invaded ponds with highly organic sediments for most of the summer, suggesting that terrestrially derived inorganic carbon was insufficient to meet the demands of algal net production. In contrast, ponds with highly mineral sediments continued to evade CO2 during the summer. In a subset of 11 ponds, long‐term rates of carbon accumulation in sediment ranged from 0·6 to 2·2 mol C m−2 year−1. Very strong correlations existed between average sediment accumulation rates and pond perimeters and basin areas suggesting that peat may be a major source of sediment carbon. Aeolian transport is also a potentially large source of sediment carbon. Copyright © 2004 John Wiley & Sons, Ltd.
Introduction to the special issue
Authors: Collins Frank L. , Kaslow Nadine J. , Illfelder‐Kaye Joyce 
Published: May 2004

AbstractThis special issue is a collection of seven articles from the Competencies Conference: Future Directions in Education and Credentialing in Professional Psychology. The articles include an executive summary that provides a broad overview of the conference organization and a summary of the themes that emerged from the six working groups. The workgroups included in this series focused on: (a) Scientific Foundations, (b) Psychological Assessment, (c) Intervention, (d) Individual and Cultural Diversity, (e) Supervision, and (f) Consultation and Interprofessional Collaboration. These article represent one outcome of this conference. Additional articles will appear in Professional Psychology: Research and Practice and The Counseling Psychologist. © 2004 Wiley Periodicals, Inc. J Clin Psychol.
Becoming a competent clinician: Basic competencies in intervention
Authors: Spruill Jean , Rozensky Ronald H. , Stigall Tommy T. , Vasquez Melba , Bingham Rosie Phillips , Olvey Cindy De Vaney 
Published: May 2004

AbstractThis article summarizes the results from the Intervention Work Group of the Competencies Conference: Future Directions in Education and Credentialing in Professional Psychology. The generic charge presented to the Intervention Work Group was “to address issues related to interventions.” The Intervention Work Group identified four competency components of knowledge, skills, and abilities: (a) foundational competencies; (b) intervention planning; (c) intervention implementation; and (d) intervention evaluation competencies. A fifth component that included “practice management” was labeled as “others.” Each component is discussed, including competencies that were deemed an essential knowledge, skill, and/or value. A discussion of training for intervention competence and assessing that intervention competence is included. Future directions for the science and practice of psychology in the intervention arena are summarized. This is one of a series of articles published in this issue of the Journal of Clinical Psychology. Several other articles that resulted from the Competencies Conference will appear in Professional Psychology: Research and Practice and The Counseling Psychologist. © 2004 Wiley Periodicals, Inc. J Clin Psychol.
Defining competencies in psychology supervision: A consensus statement
Authors: Falender Carol A. , Cornish Jennifer A. Erickson , Goodyear Rodney , Hatcher Robert , Kaslow Nadine J. , Leventhal Gerald , Shafranske Edward , Sigmon Sandra T. , Stoltenberg Cal , Grus Catherine 
Published: May 2004

AbstractSupervision is a domain of professional practice conducted by many psychologists but for which formal training and standards have been largely neglected. In this article, supervision is proposed as a core competency area in psychology for which a number of elements reflecting specific knowledge, skills, and values must be addressed to ensure adequate training and professional development of the trainee. Supra‐ordinate factors of supervision viewed as permeating all aspects of professional development are proposed. These include the perspective that professional development is a lifelong, cumulative process requiring attention to diversity in all its forms, as well as legal and ethical issues, personal and professional factors, and self‐ and peer‐assessment. A competencies framework is presented with particular elements representing knowledge (e.g., about psychotherapy, research, etc.), skills (including supervising modalities, relationship skills, etc.), values (e.g., responsibility for the clients and supervisee rests with supervisor, etc.), and meta‐knowledge. Social contextual factors and issues of education and training, assessment, and future directions also are addressed, with specific elements listed. Suggestions for future work in this area are addressed, including the need to refine further and operationalize competences, develop clear expectations for accreditation and licensure regarding supervision competencies, and expand the description of developmental levels of supervisors from minimal to optimal competence. This is one of a series of articles published together in this issue of the Journal of Clinical Psychology. Several other articles that resulted from the Competencies Conference: Future Directions in Education and Credentialing in Professional Psychology will appear in Professional Psychology: Research and Practice and The Counseling Psychologist. © 2004 Wiley Periodicals, Inc. J Clin Psychol.
Novel gel‐entrapped base catalysts for the Claisen–Schmidt reaction
Authors: Chaphekar Sachin S , Samant Shriniwas D 
Published: May 2004

AbstractNovel gel‐entrapped base catalysts (GEBCs) were prepared by entrapping aqueous solutions of bases in a gel matrix of agar agar. The bases used were NaOH, KOH, morpholine and piperidine. Ternary phase diagrams were constructed for the water–base–agar agar system to identify the various phases and especially the solid phase, useful as a solid base catalyst. The 10% NaOH solid gel was used to effect the Claisen–Schmidt reaction between benzaldehydes and acetophenones in ethanol under heterogeneous conditions to obtain 70–100% yield of the products. The solid GEBCs obtained using other bases were also used for the same reaction; however, the yields were lower. The catalyst needed no activation prior to use and could be recycled. Copyright © 2004 Society of Chemical Industry
Late Quaternary deglaciation and climate history of the Larsemann Hills (East Antarctica)
Authors: Verleyen Elie , Hodgson Dominic A. , Sabbe Koen , Vyverman Wim 
Published: May 2004

AbstractThe Late Quaternary climate history of the Larsemann Hills has been reconstructed using siliceous microfossils (diatoms, chrysophytes and silicoflagellates) in sediment cores extracted from three isolation lakes. Results show that the western peninsula, Stornes, and offshore islands were ice‐covered between 30 000 yr BP and 13 500 cal. yr BP. From 13 500 cal. yr BP (shortly after the Antarctic Cold Reversal) the coastal lakes of the Larsemann Hills were deglaciated and biogenic sedimentation commenced. Between 13 500 and 11 500 cal. yr BP conditions were warmer and wetter than during the preceding glacial period, but still colder than today. From 11 500 to 9500 cal. yr BP there is evidence for wet and warm conditions, which probably is related to the early Holocene climate optimum, recorded in Antarctic ice cores. Between 9500 and 7400 cal. yr BP dry and cold conditions are inferred from high lake‐water salinities, and low water levels and an extended duration of nearshore sea‐ice. A second climate optimum occurred between 7400 and 5230 cal. yr BP when stratified, open water conditions during spring and summer characterised the marine coast of Prydz Bay. From 5230 until 2750 cal. yr BP sea‐ice duration in Prydz Bay increased, with conditions similar to the present day. A short return to stratified, open water conditions and a reduction in nearshore winter sea‐ice extent is evident between 2750 and 2200 cal. yr BP. Simultaneously, reconstructions of lake water depth and salinity suggests relatively humid and warm conditions on land between 3000 and 2000 cal. yr BP, which corresponds to a Holocene Hypsithermal reported elsewhere in Antarctica. Finally, dry conditions are recorded around 2000, between 760 and 690, and between 280 and 140 cal. yr BP. These data are consistent with ice‐core records from Antarctica and support the hypothesis that lacustrine and marine sediments on land can be used to evaluate the effect of long‐term climate change on the terrestrial environment. Copyright © 2004 John Wiley & Sons, Ltd.
Surface‐Grafted Polystyrene Beads with Comb‐Like Poly(ethylene glycol) Chains: Preparation and Biological Application
Authors: Byun Jang‐Woong , Kim Jong‐Uk , Chung Woo‐Jae , Lee Yoon‐Sik 
Published: May 2004

AbstractSummary: We prepared surface‐grafted polystyrene (PS) beads with comb‐like poly(ethylene glycol) (PEG) chains. To accomplish this, conventional gel‐type PS beads (35–75 μm) were treated with ozone gas to introduce hydroperoxide groups onto the surface. Using these hydroperoxide groups, poly(methyl methacrylate) (PMMA, $\overline M _{\rm n}$ = 22 000–25 000) was grafted onto the surface of the PS beads. The ester groups of the grafted PMMA were reduced to hydroxyl groups with lithium aluminum hydride (LAH). After adding ethylene oxide (EO) to the hydroxyl groups, we obtained the PS‐sg‐PEG beads, which had a rugged surface and a diameter of 80–150 μm. We could obtain several kinds of the PS‐sg‐PEG beads by controlling the chain lengths of the grafted PMMA and the molecular weights of the PEG chains. The grafted PEG layer was about 30–50 μm thick, which was verified from the cross‐sectioned views of the fluorescamine‐labeled beads. These fluorescence images proved that the beads possessed a pellicular structure. Furthermore, we found that the surface‐grafted PEG chains had the characteristic property of reducing non‐specific protein adsorption on the beads.Cross‐sectioned photograph of fluorescence‐labeled PS‐sg‐PEG beads showing their pellicular structure.imageCross‐sectioned photograph of fluorescence‐labeled PS‐sg‐PEG beads showing their pellicular structure.
Polylactones, 67
Authors: Kricheldorf Hans R. , Rost Simon 
Published: May 2004

AbstractSummary: Spirocyclic initiators were prepared by condensation of Ge(OEt)4 and tetra(ethylene glycol), TEG, or PEG‐2000 ($\overline M _{\rm n}$ = 2 000 Da). These spirocycles were used as initiators for the ring‐expansion polymerization of L‐lactide in chlorobenzene at 120 °C. The resulting cyclic block copolymers were reacted in situ with aliphatic dicarboxylic acid dichlorides (ADADs) or with hexamethylene diisocyanate (HMDI) to achieve chain extension. The reaction conditions were optimized via model reactions. The isolated Ge‐free multiblock copolymers were characterized by viscosity and by 1H NMR measurements. In selected cases SEC measurements and MALDI‐TOF mass spectrometry were conducted. The mass spectra revealed small amounts of cyclic oligo‐ and polylactides, whereas the high molecular weight multiblock copolymers did not “fly”.Structure of spirocyclic Ge‐initiator used here.imageStructure of spirocyclic Ge‐initiator used here.
Simulation of Amorphous Nylon 6 Using SuSi, a Strategy Based on Generation–Relaxation Algorithms
Authors: Alemán Carlos , Curcó David 
Published: May 2004

AbstractSummary: The ability of SuSi to generate microstructures of polymers with hydrogen bonding interactions has been checked. This is a random procedure recently developed to localize independent minima. Calculations were performed on nylon 6, a large number of equilibrated and relaxed atomistic models, i.e. microstructures without torsional strain and atomic overlaps, being generated. Results indicated that the generation algorithm implemented in SuSi underestimates the amount of amide groups involved in hydrogen bonding interactions. This is an expected result since no specific criterion was introduced in it to facilitate the formation of specific interactions. Several modifications have been introduced in the generation algorithm to overcome this limitation. The changes induced by these modifications in the generated microstructures are discussed.A new computational strategy denoted SuSi generates atomistic models of hydrogen bond forming polymers with very reliable results.imageA new computational strategy denoted SuSi generates atomistic models of hydrogen bond forming polymers with very reliable results.
Deconvolution of Molecular Weight Distributions Using Dynamic Flory‐Schulz Distributions
Authors: Fortuny Montserrat , Nele Márcio , Melo Príamo A. , Pinto José Carlos 
Published: May 2004

AbstractSummary: The deconvolution of molecular weight distributions (MWDs) may be useful for obtaining information about the polymerization kinetics and properties of catalytic systems. However, deconvolution techniques are normally based on steady‐state assumptions and very little has been reported about the use of non‐stationary approaches for the deconvolution of MWDs. In spite of this, polymerization reactions are often performed in batch or semi‐batch modes. For this reason, dynamic solutions are proposed here for simple kinetic models and are then used for deconvolution of actual MWD data. Deconvolution results obtained with dynamic models are compared to deconvolution results obtained with the standard stationary Flory‐Schulz distributions. For coordination polymerizations, results show that dynamic MWD models are able to describe experimental data with fewer catalytic sites, which indicates that the proper interpretation of the reaction dynamics may be of fundamental importance for kinetic characterization. On the other hand, reaction dynamics induced by modification of chain transfer agent concentration seem to play a minor role in the shape of the MWD in free‐radical polymerizations.This Figure illustrates that MWDs obtained at unsteady conditions should not be deconvoluted with standard steady‐state Flory‐Schulz distributions.imageThis Figure illustrates that MWDs obtained at unsteady conditions should not be deconvoluted with standard steady‐state Flory‐Schulz distributions.
On the Ergodicity of Dynamic Monte Carlo Simulations of Multichain or Star Systems
Authors: Limpouchová Zuzana , Procházka Karel 
Published: May 2004

AbstractSummary:The behavior of complex polymer structures, e.g., star and comb polymers or shells of polymer micelles, is often studied by dynamic Monte Carlo simulations. The algorithm, which is based on a sequence of independent steps, each of them consisting in dissolving and regrowing a randomly chosen tethered chain by the configuration‐bias Monte Carlo (CBMC) method, is considered. During each step, the remaining self‐avoiding walks (SAWs), which occupy the space, create geometrical restriction for the new SAW and hinder certain conformations. Hence, the reconstruction of the SAW under consideration depends on conformations of the other SAWs forming the system, and therefore, it is not directly evident whether the a priori ergodicity of SAW for a single untethered chain has been retained in the final algorithm for the whole multichain system. The proof of ergodicity of this type of simulations for an arbitrary number of SAWs tethered to the convex core is presented.2D scheme of the alignment of the SAWs.image2D scheme of the alignment of the SAWs.
Change of weight‐bearing pattern before and after plantar reconstruction with free anterolateral thigh flap
Authors: Sekido Mitsuru , Yamamoto Yuhei , Furukawa Hiroshi , Sugihara Tsuneki 
Published: May 2004

AbstractWe reconstructed a large‐sized defect at the weight‐bearing plantar region by a free anterolateral thigh flap successfully. This is the first case report of using the anterolateral thigh flap for reconstruction of the plantar foot. Based on the preoperative and postoperative pedogram examinations, the pressure distribution on the weight‐bearing area reconstructed by the transferred flap was obviously improved and demonstrated a nearly normal pattern. No previous report has compared the weight‐bearing pattern before and after large plantar reconstruction with a free flap. The anterolateral thigh free flap, which provides adequate bulk and contour of the foot, and which withstands weight pressure and shearing force and has the ability to provide recovery of sensation, is considered a good alternative in covering a large weight‐bearing plantar defect. © 2004 Wiley‐Liss, Inc.