bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effects of wet meadow riparian vegetation on streambank erosion. 2. Measurements of vegetated bank strength and consequences for failure mechanics
Authors: Micheli E. R. , Kirchner J. W. 
Published: September 2002

AbstractWe measured the effect of wet meadow vegetation on the bank strength and failure mechanics of a meandering montane meadow stream, the South Fork of the Kern River at Monache Meadow, in California's Sierra Nevada. Streambanks colonized by ‘wet’ graminoid meadow vegetation were on average five times stronger than those colonized by ‘dry’ xeric meadow and scrub vegetation. Our measurements show that strength is correlated with vegetation density indicators, including stem counts, standing biomass per unit area, and the ratio of root mass to soil mass. Rushes appear better than sedges at stabilizing coarse bar surfaces, while sedges are far more effective at stabilizing actively eroding cut banks.Wet meadow floodplain vegetation creates a composite cut bank configuration (a cohesive layer overlying cohesionless materials) that erodes via cantilever failure. Field measurements and a geotechnical model of cantilever stability show that by increasing bank strength, wet meadow vegetation increases the thickness, width, and cohesiveness of a bank cantilever, which, in turn, increases the amount of time required to undermine, detach, and remove bank failure blocks. At Monache Meadow, it takes approximately four years to produce and remove a 1 m wide wet meadow bank block. Wet meadow vegetation limits bank migration rates by increasing bank strength, altering bank failure modes, and reducing bank failure frequency. Copyright © 2002 John Wiley & Sons, Ltd.
Processes and forms of an unstable alluvial system with resistant, cohesive streambeds
Authors: Simon Andrew , Thomas Robert E. 
Published: September 2002

AbstractAs a response to channelization projects undertaken near the turn of the 20th century and in the late 1960s, upstream reaches and tributaries of the Yalobusha River, Mississippi, USA, have been rejuvenated by upstream‐migrating knickpoints. Sediment and woody vegetation delivered to the channels by mass failure of streambanks has been transported downstream to form a large sediment/debris plug where the downstream end of the channelized reach joins an unmodified sinuous reach. Classification within a model of channel evolution and analysis of thalweg elevations and channel slopes indicates that downstream reaches have equilibrated but that upstream reaches are actively degrading.The beds of degrading reaches are characterized by firm, cohesive clays of two formations of Palaeocene age. The erodibility of these clay beds was determined with a jet‐test device and related to critical shear stresses and erosion rates. Repeated surveys indicated that knickpoint migration rates in these clays varied from 0·7 to 12 m a−1, and that these rates and migration processes are highly dependent upon the bed substrate. Resistant clay beds of the Porters Creek Clay formation have restricted advancement of knickpoints in certain reaches and have caused a shift in channel adjustment processes towards bank failures and channel widening. Channel bank material accounts for at least 85 per cent of the material derived from the channel boundaries of the Yalobusha River system.Strategies to reduce downstream flooding problems while preventing upstream erosion and land loss are being contemplated by action agencies. One such proposal involves removal of the sediment/debris plug. Bank stability analyses that account for pore‐water and confining pressures have been conducted for a range of hydrologic conditions to aid in predicting future channel response. If the sediment/debris plug is removed to improve downstream drainage, care should be taken to provide sufficient time for drainage of groundwater from the channel banks so as not to induce accelerated bank failures. Published in 2002 John Wiley & Sons, Ltd.
26Al and 10Be dating of late pleistocene and holocene fill terraces: a record of fluvial deposition and incision, Colorado front range
Authors: Schildgen Taylor , Dethier David P. , Bierman Paul , Caffee Marc 
Published: September 2002

AbstractCosmogenic 26Al, 10Be, and 14C dating of fluvial fill terraces in steep canyons of the Colorado Front Range provides a temporal framework for analysing episodic aggradation and incision. Results from Boulder Canyon show that terrace heights above the modern channel (grade) can be divided into: (1) Bull Lake (≳100 ka; 20–15 m above grade); (2) Pinedale (32–10 ka; 15–4 m above grade); and (3) Holocene age (<4 m above grade). No pre‐Bull Lake deposits are preserved along Boulder Canyon, and only three small remnants >15 m above grade record Bull Lake deposition. Well‐preserved terraces of Pinedale age suggest that the range of terrace height above grade reflects short‐term fluctuations in the river profile during periods of rapidly changing stream load and power. Net river incision apparently occurred during transitions to interglacial periods. Soil development and stratigraphic position, along with limited cosmogenic and 14C dating, suggest that ∼130 ka terraces in Boulder Canyon correlate with the Louviers Alluvium, and that 32 to 10 ka fills in the canyon correlate with the Broadway Alluvium on the adjacent High Plains. Late Pleistocene incision rates (∼0·15 m ka−1) along Boulder Canyon exceed pre‐late Pleistocene incision rates, and are higher than middle to late Pleistocene incision rates (∼0·04 m ka−1) on the High Plains. This study provides an example of how modern geochronologic techniques allow us to understand better rivers that drain glaciated catchments. Copyright © 2002 John Wiley & Sons, Ltd.
Evaluation Models
Authors: Stufflebeam Daniel 
Published: September 2002

AbstractIn entering a new millennium, it is a good time for evaluators to critically appraise their program evaluation approaches and decide which ones are most worthy of continued application and further development. It is equally important to decide which approaches are best abandoned. In this spirit, this monograph identifies and assesses twenty‐two approaches often employed to evaluate programs. These approaches, in varying degrees, are unique and cover most program evaluation efforts. Two of the approaches, reflecting the political realities of evaluation, are often used illegitimately to falsely characterize a program's value and are labeled pseudo‐evaluations. The remaining twenty approaches are typically used legitimately to judge programs and are divided into questions/methods‐oriented approaches, improvement/accountability approaches, and social agenda/advocacy approaches. The best and most applicable of the program evaluation approaches appear to be Client‐Centered/Responsive, Utilization‐Focused, Decision/Accountability, Consumer‐Oriented, Constructivist, Case Study, Outcome/Value‐Added Assessment, and Accreditation, with the new Deliberative Democratic approach showing promise. The approaches judged indefensible or least useful were Politically Controlled, Public Relations, Accountability (especially payment by results), Clarification Hearing, and Program Theory‐Based. The rest including Objectives‐Based, Experimental Studies, Management Information Systems, Criticism and Connoisseurship, Mixed Methods, Benefit‐Cost analysis, Performance Testing, and Objective Testing Programs were judged to have restricted though beneficial use in program evaluation. All legitimate approaches are enhanced when keyed to and assessed against professional standards for evaluations.
Portable double‐focusing mass‐spectrometer system for field gas monitoring
Authors: Diaz Jorge A. , Giese Clayton F. , Gentry W. Ronald 
Published: September 2002

AbstractTraditional mass‐spectrometry (MS) instruments have been confined to laboratory usage because of their large size, power and high‐vacuum requirements, which make them unsuitable for use in most field environments. Developments in mass spectrometers and small vacuum pump systems have now made possible the development of transportable mass‐spectrometer instruments. A portable MS device based on a miniature double‐focusing (ExB) sector‐field mass spectrometer has been developed for in situ gas analysis and monitoring applications. The device (acronym Portable‐CDFMS) uses a 1.1‐Tesla NdFeB permanent magnet, a lithographically defined electric sector, a molecular‐flow frit inlet, a spiral filament in a closed ion source, and a miniature channeltron detector. The high vacuum is provided with the use of a very compact hybrid turbomolecular and diaphragm pump combination. This MS system weighs 18 lb., is able to detect atmospheric species at the part‐per‐million (ppm) level, and has a mass range up to 200 amu, which makes this miniature mass spectrometer well suited for field applications. © 2001 John Wiley & Sons, Inc. Field Analyt Chem Technol 5: 156–167, 2001
Application of a one‐dimensional thermal flame spread model on predicting the rate of heat release in the SBI test
Authors: Hakkarainen Tuula , Kokkala Matti A. 
Published: September 2002

AbstractA one‐dimensional thermal flame spread model was applied to predict the rate of heat release in the single burning item (SBI) test on the basis of the cone calorimeter data. The input parameters were selected according to the features of the SBI test and using particle board as a model tuning material. The features of the measured and calculated rate of heat release curves were compared for a series of 33 building products. The fire growth rate (FIGRA) indices were calculated to predict the classification in the forthcoming Euroclass system. The model gave correct classification for 90% of the products studied. An essential feature of the model is that only one cone calorimeter test at the exposure level of 50 kW m−2 is needed. The model, therefore, provides a practical tool for product development and quality control. Copyright © 2001 John Wiley & Sons, Ltd.
Essential oil composition of Damask rose (Rosa damascena Mill.) distilled under different pressures and temperatures
Authors: Babu Kiran G. D. , Singh Bikram , Joshi Virendra P. , Singh Virendra 
Published: September 2002

AbstractExperiments were conducted on field distillation unit to distil rose oil and rose water from the fresh flowers of Damask rose (Rosa damascena Mill.) under different pressures and temperatures to study and compare the essential oil composition by GC–FID. The monoterpene hydrocarbons and esters were found to be in traces, and stearoptene content was found to be higher in the oil distilled under high pressure, as compared to oil produced under atmospheric pressure. In general, the percentage of total alcohols (55.25–83.41%) in rose oil increased with the increase in pressure and temperature of the distillation. Physicochemical properties of rose oil distilled at varying level of temperatures and pressures are discussed. A comparative study was also conducted of rose oil constituents from dichloromethane‐extracted rose water and redistilled rose water under atmospheric and higher pressure. At higher pressure early‐eluting components in the GC column were present in traces and decrease in total alcoholic content was observed. It can be concluded that distillation conducted under pressure does not yield good quality oil. However, dichloromethane‐extracted rose oil from rose water carries a higher amount of 2‐phenylethyl alcohol. The total rose alcohol content present in rose water was higher than in rose oil. Copyright © 2002 John Wiley & Sons, Ltd.
Essential oil composition of Curcuma longa L. cv. Roma from the plains of northern India
Authors: Raina V. K. , Srivastava S. K. , Jain Neetu , Ahmad A. , Syamasundar K. V. , Aggarwal K. K. 
Published: September 2002

AbstractPlants of Curcuma longa L. cv. Roma were grown in the agroclimatic conditions of the north Indian plains at Lucknow. The rhizomes and leaves, on hydrodistillation, each gave 2.2% of oils, which were analysed by GC and GC–MS. The rhizome oil contained 84 constituents, comprising 100% of the oil, of which the major ones were 1,8‐cineole (11.2%), α‐turmerone (11.1%), β‐caryophyllene (9.8%), ar‐turmerone (7.3%) and β‐sesquiphellandrene (7.1%). The leaf oil contained 83 components, comprising 97.4% of the total oil, of which the main constituents were terpipolene (26.4%), 1,8‐cineole (9.5%), α‐phellandrene (8%) and terpinen‐4‐ol (7.4%). Copyright © 2002 John Wiley & Sons, Ltd.
Essential oil composition of three Artemisia spp. from Iran
Authors: Sefidkon F. , Jalili A. , Mirhaji T. 
Published: September 2002

AbstractThe essential oils were isolated by steam distillation from the aerial parts of A. aucheri Boiss., A. santolina Schrenk and A. sieberi Besser. The oils were analyzed by capillary GC and GC–MS. The highest oil yield was obtained from A. sieberi (1.02%). The main constituents of the oils were as follows: A. aucheri, verbenone (21.5%), camphor (21.0%) 1,8‐cineole (8.3%) and trans‐verbenol (8.1%); A. santolina, neryl acetate (13.4%), bornyl acetate (10.9%), trans‐verbenol (9.9%), lavendulol (8.8%), linalool (6.9%) and 1,8‐cineole (6.5%); A. sieberi, camphor (49.3%), 1,8‐cineole (11.1%) and bornyl acetate (5.8%). Copyright © 2002 John Wiley & Sons, Ltd.
Essential oil of Salvia officinalis L. from Serbia and Montenegro
Authors: Couladis Maria , Tzakou Olga , Mimica‐Dukić Neda , Jančić Radiša , Stojanović Danilo 
Published: September 2002

AbstractThe content and composition of essential oil in the leaves and flowers of 11 populations of Salvia officinalis L. native in Montenegro (nine populations) and Serbia (two populations) have been studied. The yield of oils was generally higher in the leaves than the flowers. The Serbian populations proved to be the richest in leaf oil (average content 1.66%). Montenegro speciments showed significant interpopulation variation and the yields averaged 1.41% for the leaves and 1.13% for the flowers. The main compounds in the leaves were oxygenated monoterpenes: α‐thujone (15.79 ± 4.9%), β‐thujone (3.49 ± 1.21%), 1.8‐cineol (12.09 ± 3.5%), camphor (11.49 ± 7.69%), borneol (4.17 ± 2.23%) and bornyl acetate (2.19 ± 1.22%). Among the dominant sesquiterpenes were: α‐humulene (7.70 ± 3.12%), viridiflorol (13.19 ± 5.17%) and manool (7.67 ± 2.98%). In the flowers, percentages of α‐thujone and camphor were significantly lower than in the leaves and averaged 9.97 ± 1.49% and 5.82 ± 5.6%, respectively, whereas the ratios of borneol (6.35 ± 2.47%) and sesquiterpenes, particularly manool (13.48 ± 3.56%), were higher. Great variation was found in the proportions of the major compounds between the populations examined. Copyright © 2002 John Wiley & Sons, Ltd.
Constituents of the essential oil of six Helichrysum species from Madagascar
Authors: Cavalli Jean‐François , Ranarivelo Lalasoa , Ratsimbason Michel , Bernardini Antoine‐François , Casanova Joseph 
Published: September 2002

AbstractThe essential oils of six Helichrysum species from Madagascar were investigated and 46 components were identified by GC, GC–MS and 13C‐NMR spectrometry. The main constituents were 1,8‐cineole for H. gymnocephalum (59.7%) and H. bracteiferum (27.3%); β‐pinene for H. selaginifolium (38.2%); (E)‐caryophyllene for H. cordifolium (55.6%), H. faradifani (34.6%) and H. hypnoides (34.0%). Copyright © 2001 John Wiley & Sons, Ltd.
Headspace–SPME analysis of volatiles of the ridge gourd (Luffa acutangula) and bitter gourd (Momordica charantia) flowers
Authors: Fernando L. N. , Grün I. U. 
Published: September 2002

AbstractThe headspace (HS) volatile compounds of the flowers of ridge gourd (Luffa acutangula) and bitter gourd (Momordica charantia) were analysed by solid‐phase microextraction (SPME) coupled with capillary gas chromatography/mass spectrometry (GC–MS). In the ridge gourd, 16 volatiles were positively identified and nine were tentatively identified, while in the bitter gourd 13 compounds were positively identified and six were tentatively identified. Typical compounds that are found in essential oils and fragrances such as terpenes, hydrocarbons and oxygenated terpenes were successfully identified. For the ridge gourd, the results showed that with more than 90% of the headspace, the most abundant volatile compound of the flower is trans‐β‐ocimene. For the bitter gourd flower, the four most abundant compounds were identified as linalool (5% of total headspace), 2‐aminobenzaldehyde (27% of total headspace), 1H‐indole (33% of total headspace) and methyl anthranilate (32% of total headspace), accounting for over 95% of the headspace volatiles of the flower. These results indicate that SPME coupled with GC–MS is a potential alternative for the effective extraction and analysis of odours of rare, exotic, delicate flowers. Copyright © 2001 John Wiley & Sons, Ltd.
Numerical computations of supersonic inlet flow
Authors: Gokhale S. S. , Kumar Venkat Ramana 
Published: September 2002

AbstractAir‐breathing propulsion systems for high‐speed space travel applications are studied. Ramjets and scramjets have been identified as potential candidates. The flow inlets of such systems are modelled with a simulation that can predict all complex inlet flow features, including shock due to forebody, multiple shock reflections, normal shock, shock–boundary layer interaction and associated separation for two‐dimensional and axisymmetric inlets. Computed values are in good agreement with experimental data. Copyright © 2001 John Wiley & Sons, Ltd.
Improved linear interpolation practice for finite‐volume schemes on complex grids
Authors: Lehnhäuser T. , Schäfer M. 
Published: September 2002

AbstractMethods for the computation of flow problems based on finite‐volume discretizations and pressure‐correction methods frequently require the interpolation of control volume face values from nodal values. The simple, often employed central differencing scheme (CDS) leads to a significant loss in accuracy when the numerical grid is non‐regular as it is usual when modelling complex geometries. An alternative technique based on a multi‐dimensional Taylor series expansion (TSE) is proposed, which preserves the CDS‐like sparsity pattern of the discrete system. While the TSE scheme computationally is only slightly more expensive than the CDS approach, it results in a significantly higher accuracy, where the difference increases with the grid irregularity. The method is investigated and compared to the CDS approach for some representative test cases. Copyright © 2002 John Wiley & Sons, Ltd.
Simulation of pressure‐tooling wire‐coating flow with Phan‐Thien/Tanner models
Authors: Ngamaramvaranggul V. , Webster M. F. 
Published: September 2002

AbstractAnnular pressure‐tooling extrusion is simulated for a low density polymer melt using a Taylor–Petrov–Galerkin finite element scheme. This represents industrial‐scale wire‐coating. Viscoelastic fluids are modeled via three forms of Phan‐Thien/Tanner (PTT) constitutive laws employed for short‐die and full specification pressure‐tooling. Effects of variation in Weissenberg number (We) and polymeric viscosity are investigated. Particular attention is paid to mesh refinement to predict accurate results. The impact of variation in shear‐thinning and strain‐softening properties is considered upon the modelling predictions. For the short‐die flow, the influence of the lack of strain softening is identified. For the full‐die flow and more severe deformation rates, the linear PTT model failed to converge. In contrast, the exponential PTT model is found to be more stable numerically and to adequately reflect the material response. Comparing short‐die and full‐die pressure‐tooling results, shear rates increase 10‐fold, while strain rates increase one hundred times. Copyright © 2002 John Wiley & Sons, Ltd.
Large‐scale organization of moist convection in idealized aquaplanet simulations
Authors: Grabowski Wojciech W. 
Published: September 2002

AbstractThis paper discusses results from idealized simulations using a non‐hydrostatic general circulation model with Cloud‐Resolving Convection Parameterization (CRCP, the ‘super parameterization’) pertinent to the large‐scale organization of tropical convection. The essence of tropical dynamics is the intricate balance between large‐scale processes—such as radiative transfer, large‐scale waves, monsoons, Hadley and Walker circulations—and the convective dynamics. Traditional approaches to this problem consider either large‐scale models using convection parameterization or cloud‐resolving models in which large‐scale effects are prescribed. The CRCP merges the two approaches. It uses a 2D cloud‐resolving model to represent the impact of cloud‐scale processes—such as convective motions, precipitation formation and fallout, interaction of clouds with radiative and surface processes—in every column of a large‐scale or global model. The global CRCP model is applied to the idealized problem of a rotating constant‐SST aquaplanet in convective–radiative equilibrium. The aquaplanet has the size and rate of rotation of the Earth. The global CRCP simulations feature pronounced large‐scale organization of convection within the equatorial waveguide. Prominent equatorial ‘super cloud clusters’ spontaneously develop in CRCP global simulations and bear a strong resemblance to the Madden–Julian Oscillation observed in the terrestrial tropics. Model results suggest that convective transport of zonal momentum, supposedly due to the impact of organized convection, plays a significant role in the large‐scale organization of tropical deep convection. Copyright © 2002 John Wiley & Sons, Ltd.
Robust evaluation of fixed‐event forecast rationality
Authors: Clements Michael P. , Taylor Nick 
Published: September 2002

AbstractIn this paper we introduce a new testing procedure for evaluating the rationality of fixed‐event forecasts based on a pseudo‐maximum likelihood estimator. The procedure is designed to be robust to departures in the normality assumption. A model is introduced to show that such departures are likely when forecasters experience a credibility loss when they make large changes to their forecasts. The test is illustrated using monthly fixed‐event forecasts produced by four UK institutions. Use of the robust test leads to the conclusion that certain forecasts are rational while use of the Gaussian‐based test implies that certain forecasts are irrational. The difference in the results is due to the nature of the underlying data. Copyright © 2001 John Wiley & Sons, Ltd.
Homozygous deletion in a neuroblastoma cell line defined by a high‐density STS map spanning human chromosome band 1p36
Authors: Chen Ying Zhang , Soeda Eiichi , Yang Hong Wei , Takita Junko , Chai Ling , Horii Akira , Inazawa Johji , Ohki Misao , Hayashi Yasuhide 
Published: September 2002

AbstractRecent molecular studies have shown a relatively high rate of loss of heterozygosity (LOH) in neuroblastoma (NB) as well as other types of tumors in human chromosome band 1p36. To identify candidate tumor suppressor genes in NB, we searched for homozygous deletions in NB cell lines with PCR according to a high‐density sequence tagged site (STS)‐content map spanning 1p35–36. Among 25 NB cell lines examined, only one cell line, NB‐1, showed no signal with 27 STSs in a 480 kb region in 1p36.2. The sequence analysis has revealed that the defective region included seven known genes (E4, KIF1B, SCYA5, PGD, Cortistatin, DFF45, and PEX14), nine expressed sequence tags (ESTs), and two microsatellite markers. These genes are related to apoptosis, an ubiquitin‐proteasome pathway, a neuronal microtubule‐associated motor molecule, and components of a common translocation machinery. The region between the DFF45 and KIF1B genes was defined as homozygous deletion by Southern blotting. The search in LOH regions with high‐density STSs may be useful for the isolation and identification of tumor suppressor genes in other tumors as well as NBs. © 2001 Wiley‐Liss, Inc.