bluuebunny/crossref_metadata_2025_split huggingface dataset:
Heat transfer characteristics in a condenser of closed two‐phase thermosyphon: Effect of entrainment on heat transfer deterioration
Authors: Hashimoto Hiroyuki , Kaminaga Fumito 
Published: August 2002

AbstractCondensation heat transfer in a closed two‐phase thermosyphon is experimentally examined using two different types of test section. Test Section 1 is a straight‐pipe‐type thermosyphon, whereas Test Section 2 has a large‐diameter evaporator compared with a condenser to minimize entrainment at the evaporator. Condensation heat transfer in Test Section 1 shows much lower heat transfer coefficients than those estimated by a Nusselt theory. This low condensation heat transfer occurs due to a working fluid entrainment. It is confirmed from a result of Test Section 2 that the condensation heat transfer is similar to the values predicted by the Nusselt theory as far as the effect of the working fluid entrainment is negligible and flooding does not occur. A new correlation for the heat transfer coefficient considering the effect of entrainment is proposed. © 2002 Wiley Periodicals, Inc. Heat Trans Asian Res, 31(3): 212–225, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/htj.10030
Stress‐induced insomnia treated with kava and valerian: singly and in combination
Authors: Wheatley David 
Published: August 2002

AbstractKava and valerian are herbal remedies that are claimed to have anxiolytic and sedative properties respectively, without dependence potential or any appreciable side effects. In this pilot study, 24 patients suffering from stress‐induced insomnia were treated for 6 weeks with kava (LI‐150), 120 mg daily. This was followed by a 2‐week ‘wash‐out’ period off treatment, and then, five patients having dropped out, 19 received valerian (LI‐156), 600 mg daily, for another 6 weeks. Then there was a further 2‐week period off treatment, and a final 6 weeks of treatment of these 19 patients with the two compounds combined (kava + valerian). Stress was measured in three areas: social, personal and life events; insomnia in three areas also: time to fall asleep, hours slept and waking mood. Total stress severity was significantly relieved by both compounds individually (p < 0.01), with no significant differences between them; and there was also improvement with the combination, significant in the case of insomnia (p < 0.05). On direct questioning, 16 patients (67%) reported no side effects on kava, 10 (53%) on valerian and 10 (53%) on the combination. The ‘commonest’ effect was vivid dreams with kava + valerian (4 cases (21%)) and with valerian alone (3 cases (16%)), followed by gastric discomfort and dizziness with kava (3 cases each (3 %)). These results are considered to be extremely promising but further studies may be required to determine the relative roles of the two compounds for such indications. Copyright © 2001 John Wiley & Sons, Ltd.
Seasonal variation in the energy and water exchanges above and below a larch forest in eastern Siberia
Authors: Ohta Takeshi , Hiyama Tetsuya , Tanaka Hiroki , Kuwada Takashi , Maximov Trofim C. , Ohata Tetsuo , Fukushima Yoshihiro 
Published: August 2002

AbstractThe water and energy exchanges in forests form one of the most important hydro‐meteorological systems. There have been far fewer investigations of the water and heat exchange in high latitude forests than of those in warm, humid regions. There have been few observations of this system in Siberia for an entire growing season, including the snowmelt and leaf‐fall seasons. In this study, the characteristics of the energy and water budgets in an eastern Siberian larch forest were investigated from the snowmelt season to the leaf‐fall season. The latent heat flux was strongly affected by the transpiration activity of the larch trees and increased quickly as the larch stand began to foliate. The sensible heat dropped at that time, although the net all‐wave radiation increased. Consequently, the seasonal variation in the Bowen ratio was clearly ‘U’‐shaped, and the minimum value (1·0) occurred in June and July. The Bowen ratio was very high (10–25) in early spring, just before leaf opening. The canopy resistance for a big leaf model far exceeded the aerodynamic resistance and fluctuated over a much wider range. The canopy resistance was strongly restricted by the saturation deficit, and its minimum value was 100 s m−1 (10 mm s−1 in conductance). This minimum canopy resistance is higher than values obtained for forests in warm, humid regions, but is similar to those measured in other boreal conifer forests. It has been suggested that the senescence of leaves also affects the canopy resistance, which was higher in the leaf‐fall season than in the foliated season. The mean evapotranspiration rate from 21 April 1998 to 7 September 1998 was 1·16 mm day−1, and the maximum rate, 2·9 mm day−1, occurred at the beginning of July. For the growing season from 1 June to 31 August, this rate was 1·5 mm day−1. The total evapotranspiration from the forest (151 mm) exceeded the amount of precipitation (106 mm) and was equal to 73% of the total water input (211 mm), including the snow water equivalent. The understory evapotranspiration reached 35% of the total evapotranspiration, and the interception evaporation was 15% of the gross precipitation. The understory evapotranspiration was high and the interception evaporation was low because the canopy was sparse and the leaf area index was low. Copyright © 2001 John Wiley & Sons, Ltd.
Application of a data‐based mechanistic modelling (DBM) approach for predicting runoff generation in semi‐arid regions
Authors: Mwakalila S. , Campling P. , Feyen J. , Wyseure G. , Beven K. 
Published: August 2002

AbstractThis paper addresses the application of a data‐based mechanistic (DBM) modelling approach using transfer function models (TFMs) with non‐linear rainfall filtering to predict runoff generation from a semi‐arid catchment (795 km2) in Tanzania. With DBM modelling, time series of rainfall and streamflow were allowed to suggest an appropriate model structure compatible with the data available. The model structures were evaluated by looking at how well the model fitted the data, and how well the parameters of the model were estimated. The results indicated that a parallel model structure is appropriate with a proportion of the runoff being routed through a fast flow pathway and the remainder through a slow flow pathway. Finally, the study employed a Generalized Likelihood Uncertainty Estimation (GLUE) methodology to evaluate the parameter sensitivity and predictive uncertainty based on the feasible parameter ranges chosen from the initial analysis of recession curves and calibration of the TFM. Results showed that parameters that control the slow flow pathway are relatively more sensitive than those that control the fast flow pathway of the hydrograph. Within the GLUE framework, it was found that multiple acceptable parameter sets give a range of predictions. This was found to be an advantage, since it allows the possibility of assessing the uncertainty in predictions as conditioned on the calibration data and then using that uncertainty as part of the decision‐making process arising from any rainfall‐runoff modelling project. Copyright © 2001 John Wiley & Sons, Ltd.
Representing elevation uncertainty in runoff modelling and flowpath mapping
Authors: Endreny Theodore A. , Wood Eric F. 
Published: August 2002

AbstractVertical inaccuracies in terrain data propagate through dispersal area subroutines to create uncertainties in runoff flowpath predictions. This study documented how terrain error sensitivities in the D8, Multiple Flow (MF), DEMON, D‐Infinity and two hybrid dispersal area algorithms, responded to changes in terrain slope and error magnitude. Runoff dispersal areas were generated from convergent and divergent sections of low, medium, and high gradient 64‐ha parcels using a 30 m pixel scale control digital elevation model (DEM) and an ensemble of alternative realizations of the control DEM. The ensemble of alternative DEM realizations was generated randomly to represent root mean square error (RMSE) values ranging from 0·5 to 6 m and spatial correlations of 0 to 0·999 across 180 m lag distances. Dispersal area residuals, derived by differencing output from control and ensemble simulations, were used to quantify the spatial consistency of algorithm dispersal area predictions. A maximum average algorithm consistency of 85% was obtained in steep sloping convergent terrain, and two map analysis techniques are recommended in maintaining high spatial consistencies under less optimum terrain conditions. A stochastic procedure was developed to translate DEM error into dispersal area probability maps, and thereby better represent uncertainties in runoff modelling and management. Two uses for these runoff probability maps include watershed management indices that identify the optimal areas for intercepting polluted runoff as well as Monte‐Carlo‐ready probability distributions that report the cumulative pollution impact of each pixel's downslope dispersal area. Copyright © 2001 John Wiley & Sons, Ltd.
The use of Fick's First Law for predicting porewater nutrient fluxes under diffusive conditions
Authors: Lavery Paul S. , Oldham Carolyn E. , Ghisalberti Marco 
Published: August 2002

AbstractPorewater fluxes into or out of the sediments in aquatic systems are frequently estimated using Fick's First Law. This assumes that diffusive processes control the transport of nutrients. As a corollary, advection, bioturbation and chemical processes are assumed not to be significant. Through a series of sediment core incubations, this paper seeks to quantify the uncertainties involved in such assumptions. Duplicate sediment cores were collected from 28 sites along the Swan–Canning Estuary, returned to the laboratory and incubated under oxic or anoxic conditions. Porewater nutrient concentrations, sediment porosity and initial nutrient concentrations in the overlying water were measured. These parameters were used to estimate the expected nutrient fluxes via Fick's First Law. The estimated fluxes were then compared with measured fluxes of nutrients out of the sediments over the incubation period. Severe bioturbation occurred in several of the anoxic treatments, resulting in large releases of nutrients into the overlying water. Aside from these bioturbated cores, phosphate and ammonium fluxes under anoxic conditions are well predicted by Fick's First Law. Nitrate fluxes are predicted well under oxic conditions. For coarse sediments (D10 averaging 0·3 mm) and under redox conditions favourable for nutrient release, Fick's First Law predicted close to 100% of the observed fluxes. For finer grain sediments (D10 < 0·01 mm), Fick's First Law overestimated the observed flux by up to 40%. Under unfavourable oxygen conditions, chemical retardation processes are likely to dominate fluxes, and the error associated with using Fick's First Law is increased. These results confirm the usefulness of using Fick's First Law for a baseline estimate of nutrient fluxes under favourable redox conditions. Much greater care must be taken when using Fick's First Law to estimate nutrient fluxes under unfavourable redox conditions, or under conditions when bioturbation is likely to be severe. Copyright © 2001 John Wiley & Sons, Ltd.
Towards an alternative blueprint for a physically based digitally simulated hydrologic response modelling system
Authors: Beven Keith 
Published: August 2002

AbstractA critique of the Freeze and Harlan blueprint for a distributed physically based hydrological model leads to the conclusion that it will be abandoned. An alternative blueprint as a modelling methodology is proposed that explicitly recognises the potential for equifinality in scale‐dependent model representations. An inductive rather than deductive definition of physically‐based is proposed that reflects the important role of observables in constraining the feasible models. Copyright © 2002 John Wiley & Sons, Ltd.
Diffusion model validation and interpretation of stable isotopes in river and lake ice
Authors: Ferrick M. G. , Calkins D. J. , Perron N. M. , Cragin J. H. , Kendall C. 
Published: August 2002

AbstractThe stable isotope stratigraphy of river‐ and lake‐ice archives winter hydroclimatic conditions, and can potentially be used to identify changing water sources or to provide important insights into ice formation processes and growth rates. However, accurate interpretations rely on known isotopic fractionation during ice growth. A one‐dimensional diffusion model of the liquid boundary layer adjacent to an advancing solid interface, originally developed to simulate solute rejection by growing crystals, has been used without verification to describe non‐equilibrium fractionation during congelation ice growth. Results are not in agreement, suggesting the presence of important uncertainties. In this paper we seek validation of the diffusion model for this application using large‐scale laboratory experiments with controlled freezing rates and frequent sampling. We obtained consistent, almost constant, isotopic boundary layer thicknesses over a representative range of ice growth rates on both quiescent and well‐mixed water. With the 18O boundary layer thickness from the laboratory, the model successfully quantified reduced river‐ice growth rates relative to those of a nearby lake. These results were more representative and easier to obtain than those of a conventional thermal ice‐growth model. This diffusion model validation and boundary layer thickness determination provide a powerful tool for interpreting the stable isotope stratigraphy of floating ice. The laboratory experiment also replicated successive fractionation events in response to a freeze–thaw–refreeze cycle, providing a mechanism for apparent ice fractionation that exceeds equilibrium. Analysis of the composition of snow ice and frazil ice in river and lake cores indicated surprising similarities between these ice forms. Published in 2002 by John Wiley & Sons, Ltd.
Developing a post‐fire flood chronology and recurrence probability from alluvial stratigraphy in the Buffalo Creek watershed, Colorado, USA
Authors: Elliott John G. , Parker R. S. 
Published: August 2002

AbstractStratigraphic and geomorphic evidence indicate floods that occur soon after forest fires have been intermittent but common events in many mountainous areas during the past several thousand years. The magnitude and recurrence of these post‐fire flood events reflects the joint probability between the recurrence of fires and the recurrence of subsequent rainfall events of varying magnitude and intensity. Following the May 1996 Buffalo Creek, Colorado, forest fire, precipitation amounts and intensities that generated very little surface runoff outside of the burned area resulted in severe hillslope erosion, floods, and streambed sediment entrainment in the rugged, severely burned, 48 km2 area. These floods added sediment to many existing alluvial fans, while simultaneously incising other fans and alluvial deposits. Incision of older fans revealed multiple sequences of fluvially transported sandy gravel that grade upward into charcoal‐rich, loamy horizons. We interpret these sequences to represent periods of high sediment transport and aggradation during floods, followed by intervals of quiescence and relative stability in the watershed until a subsequent fire occurred.An alluvial sequence near the mouth of a tributary draining a 0·82 km2 area indicated several previous post‐fire flood cycles in the watershed. Dendrochronologic and radiocarbon ages of material in this deposit span approximately 2900 years, and define three aggradational periods. The three general aggradational periods are separated by intervals of approximately nine to ten centuries and reflect a ‘millennium‐scale’ geomorphic response to a closely timed sequence of events: severe and intense, watershed‐scale, stand‐replacing fires and subsequent rainstorms and flooding. Millennium‐scale aggradational units at the study site may have resulted from a scenario in which the initial runoff from the burned watershed transported and deposited large volumes of sediment on downstream alluvial surfaces and tributary fans. Subsequent storm runoff may have produced localized incision and channelization, preventing additional vertical aggradation on the sampled alluvial deposit for several centuries. Two of the millennium‐scale aggradational periods at the study site consist of multiple gravel and loam sequences with similar radiocarbon ages. These closely dated sequences may reflect a ‘multidecade‐scale’ geomorphic response to more frequent, but aerially limited and less severe fires, followed by rainstorms of relatively common recurrence. Published in 2001 John Wiley & Sons, Ltd.
Portable irrigation system for studying hillslope and wetland runoff generation processes
Authors: Waddington J. M. , Devito K. J. 
Published: August 2002

AbstractThe advantage of an irrigation system is that experiments of varying precipitation duration and intensity can be performed in a controlled situation. An effective portable irrigation system is described for use in experimental plot hillslope and wetland runoff studies. The system consists of four parts:(1) a water pump; (2) a tracer reservoir; (3) a chemical feed pump; and (4) distribution hoses. Relatively uniform water application is achieved by a series of manual valves controlling water flow from the main carrier hose to the distribution hoses. The irrigation system materials are inexpensive and installation and operation costs are minor. The system was used to study runoff generation from a small‐saturated area in a spring‐fed swamp for a range of precipitation intensities and durations. The irrigation system applied a maximum intensity of 14·0mm h−1, for a maximum duration of 180 min, to a 190m2 area. This range of application incorporated all storms up to a one in three year event. The variance of the tracer load was almost three times greater for natural (60%) than with the irrigation system (22%). The irrigation system reduced the uncertainty in the pre‐event water fraction (using a two‐component hydrograph separation) from 3·4% in natural events to only 0·7%. The irrigation system design, operation, calibration and cost are presented. Copyright © 2001 John Wiley & Sons, Ltd.
Early tactile experience of low birth weight children: links to later mental health and social adaptation
Authors: Weiss Sandra J. , Wilson Peggy , Seed Mary St. Jonn , Paul Steven M. 
Published: August 2002

AbstractThe purpose of this study was twofold: to determine (1) the degree to which specific qualities of maternal touch may contribute to the low birth weight infant's emotional and behavioural problems as well as social adaptation, and (2) the relationship between maternal touch and a mother's other caregiving behaviour. The sample included 114 socioculturally diverse infants and their mothers who were videotaped during an infant feeding when the baby was 3 months old. This videotape was analysed to assess dimensions of mother–infant interaction, including maternal touch. Data on perinatal risk and the mother's acceptance versus rejection of the infant were also acquired. Social adaptation and emotional/behavioural problems were measured when the child was 2 years of age.Hierarchical regression analyses indicated that maternal touch accounted for 15% of the variance in the likelihood of a child having emotional/behavioural problems at age 2. Children who received more nurturing touch had significantly fewer internalizing problems (such as depression) while children receiving both more frequent touch and harsh touch had more externalizing problems (such as aggressive behaviour). Infants who were less responsive to their caregivers were especially at risk of developing aggressive/destructive behaviour as a result of frequent touch. But less responsive infants also appeared to benefit most from greater use of diverse types of maternal touch, accounting for 6% of the variance in superior adaptive behaviour at age 2. Nurturing touch was the only quality that showed even a modest relationship to other caregiving behaviour, suggesting that touch may play a distinct role in the infant's psychosocial development. Copyright © 2001 John Wiley & Sons, Ltd.
Language development of pre‐school children born to teenage mothers
Authors: Keown Louise J. , Woodward Lianne J. , Field Jeff 
Published: August 2002

AbstractAn Erratum has been published for this article in
Infant and Child Development 10(4) 2001, 241.This paper compares the language development of pre‐school children born to teenage (n=22) and comparison mothers (n=20) and examines the extent to which differences in language development can be explained by social background, child and parenting factors. Mothers and children were assessed at home using a range of measures, including a structured interview, the language scales of the Child Development Inventory, the HOME Inventory, and videotaped mother‐child interaction. Results showed that children of teenage mothers perform significantly poorer than children of comparison mothers on measures of expressive language and language comprehension. Subsequent analyses showed that these differences are largely explained by differences in the parenting behaviour of teenage and comparison mothers. Specifically, maternal verbal stimulation and intrusiveness accounted for the relationship between teenage motherhood and children's poorer language comprehension, while maternal intrusiveness and involvement with the child account for the relationship between teenage motherhood and children's poorer expressive language development. These findings highlight the importance of early mother–child interaction for children's language development. Copyright © 2001 John Wiley & Sons, Ltd.
Resistance of colon cancer cells to long‐term 5‐fluorouracil exposure is correlated to the relative level of Bcl‐2 and Bcl‐XL in addition to Bax and p53 status
Authors: Violette Sabine , Poulain Laurent , Dussaulx Elisabeth , Pepin Dominique , Faussat Anne‐Marie , Chambaz Jean , Lacorte Jean‐Marc , Staedel Cathy , Lesuffleur Thécla 
Published: August 2002

AbstractDefects in apoptosis have been implicated in chemoresistance of colon cancer cells. We report here the ability to resist to 5‐fluorouracil‐induced apoptosis of 8 colon cancer cell lines differing in p53 and bax status: p53−/0bax+/+ for TC7, SW480, HT‐29; p53+/+bax−/− for LS174T, LoVo; p53+/+ bax+/− for HCT116; p53+/+ or p53+/0bax+/+ for LS513 or HCT‐EB, respectively. To approximate to the in vivo therapy, the cell lines were exposed to a long‐term treatment of 5‐FU. The analysis of proteins implicated in the apoptotic pathway has shown that the independent analysis of p53 or bax status was not sufficient to predict the extent of drug‐resistance of all cell lines. In p53+/+ cell lines but not in p53−/0 cell lines, a low level of the pro‐apoptotic Bax protein was correlated with a greater resistance of cells to 5‐FU. In addition, we found that high levels of anti‐apoptotic Bcl‐2 and Bcl‐xL proteins combined with a low level of Bax were correlated to high 5‐FU resistance of wild‐type p53 cell lines. The same correlation was obtained for 2 out of 3 mutated p53 cell lines. In conclusion, the relative levels of Bcl‐2, Bcl‐xL and Bax may altogether contribute to determine the resistance of a majority of colon tumor cells to long‐term 5‐FU treatment, whatever their p53 status. © 2002 Wiley‐Liss, Inc.