bluuebunny/crossref_metadata_2025_split huggingface dataset:
Sorptive–Flotation of Copper(II) from Water Using Different Types of Powdered Activated Carbons as Sorbents and Oleic Acid as Surfactant
Authors: Ghazy S.E. , Samra S.E. , El-Morsy S.M. 
Published: October 2002

Different types of powdered activated carbon, viz. charcoal (PACh), graphite (PG) and three samples (PACI, PACII and PACIII) prepared from olive stones generated as plant wastes and modified with aqueous oxidizing agents, viz. H2O2, HNO3 and (NH4)2S2O8, were separated from aqueous solution by flotation using oleic acid (HOL) as a surfactant. The effects of initial temperature, initial pH of the suspension, initial carbon and surfactant concentrations, stirring times and the presence of foreign ions on the flotation efficiency of the carbon samples were investigated. Under optimum conditions, separation of the carbon samples was almost complete (~100%). The separation of CuII-loaded carbon was also examined in the presence and absence of sulphide ions as activators. Nearly 100% CuII was removed at pH 7 after stirring for 30 min or on raising the temperature of the solution to 30°C or higher. In addition, CuII may be separated quantitatively at pH 3 and room temperature if sulphide ions are used as activators. The procedure was extended to the recovery of CuII added to some natural water samples. On the basis of IR analyses and neutralization titrations of the surface groups, a mechanism for the sorption and flotation processes is advanced.
Adsorptive and Membrane-Type Separations: A Bibliographical Update (2000)
Authors: Ray Martyn S. 
Published: October 2002

This paper continues a series of annual bibliographic updates (data from 1985) of the published literature on selected particulate processes (see Ray 1990–2000). It provides a useful and quick reference source to the journal literature for the year 2000 (taken from the 50 most important chemical engineering journals) for researchers in this area. The references included here have been divided into the following subject groups: theory, design data, adsorbents, PSA and cyclic systems and applications, liquid-phase adsorption ion exchange, chromatography and related separations, membranes and membrane-type separations. Adsorption and related separations for industrial and environmental applications are described in detail in Dabrowski (1999) which also contains extensive bibliographies prepared by this author. A complete bibliographic listing of the chemical engineering journal literature from 1959 to 2000 (with subsequent six-monthly updates) is available on a CD-ROM database*. Full details are available from www.rmitpublishing.com.au , or the author (MSR).
Systematic Controller Design Methodology for Variable-Speed Wind Turbines
Authors: Hand M. Maureen , Balas Mark J. 
Published: October 2002

Variable-speed, horizontal axis wind turbines use blade-pitch control to meet specified objectives for three regions of operation. This paper provides a guide for controller design for the constant power production regime. A simple, rigid, non-linear turbine model was used to systematically perform trade-off studies between two performance metrics. Minimization of both the deviation of the rotor speed from the desired speed and the motion of the actuator is desired. The robust nature of the proportional-integral-derivative controller is illustrated, and optimal operating conditions are determined. Because numerous simulation runs may be completed in a short time, the relationship between the two opposing metrics is easily visualized. Traditional controller design generally consists of linearizing a model about an operating point. This step was taken for two different operating points, and the systematic design approach was used. The surfaces generated by the systematic design approach using the two linear models are similar to those generated using the non-linear model. The gain values selected using either linear model-based design are similar to those selected using the non-linear model-based design. The linearization point selection does, however, affect the turbine performance. Inclusion of complex dynamics in the simulation may exacerbate the small differences evident in this study. Thus, knowledge of the design variation due to linearization point selection is important.
Case Study: Acoustic Design of a Restored Theatre in Thessaloniki
Authors: Tsinikas N. P. 
Published: October 2002

This paper discusses the acoustics of a restored theatre in Thessaloniki, Greece. The paper presents the acoustic design principles, discusses the employment of these principles and concludes with an assessment of the success of the design. The acoustic design changes included improvement of direct sound, provision of ceiling and walls reflections, positioning of diffusers, optimising reverberation time and minimising background noise levels. Steeper seating rakes were constructed in the stalls, boxes and balconies. Curved ceiling reflectors were positioned in a new wire frame false ceiling. Lateral wall reflectors were introduced, as were curved side walls near the stage to act as diffusers. Diffusers were positioned in the rear walls and in balcony fronts. Reverberation times were predicted, measured and compared with earlier data, based on the change of volume, the number and design of seats and the volume per seat ratio. Finally, noise level measurements were obtained in most of the spaces in the theatre. Assessment of the success of the design is based on measurement results and on the subjective acceptance by theatre goers.
On the Performance of Base-Isolated Buildings
Authors: Talbot J.P. , Hunt H.E.M. 
Published: October 2002

Base isolation is a means of reducing the transmission of vibration into buildings and was first used in the 1960s. Since then many buildings have been mounted on springs of various types in order to reduce the effects of ground-borne vibration from roads and railways. For most applications, the building rests on steel springs or laminated rubber bearings. A typical objective is a reduction in vibration transmission of at least 10 dB for frequencies above 10 Hz, but, while difficult to verify, such performance is probably rarely ever achieved. Current practice suggests that the choice of spring type has a significant effect on the efficiency of the vibration isolation, as well as having implications on the cost and implementation of the system. However, there remain unanswered a number of fundamental questions concerning the specification and design of isolation bearings for buildings. For example, what is the most appropriate stiffness of the bearings for a given application and to what extent is damping an important part of a good system? This paper reviews current methods of predicting isolation performance and introduces an alternative model which aims to model more fully the behaviour of base-isolated buildings. The benefits of a power-flow approach in assessing isolation performance are also discussed and it is argued that this enables a more appropriate measure of performance to be defined than one based on vibration amplitudes alone.
Is There a Systematic Disagreement between Intensity-Based and Pressure-Based Sound Transmission Loss Measurements?
Authors: Machimbarrena María , Jacobsen Finn 
Published: October 2002

Conventional and intensity-based sound transmission loss measurements have frequently been compared in the literature. Looking at published results determined under laboratory conditions, one would come to the conclusion that it is only possible to obtain good agreement between the two methods in a very restricted frequency range. It has often been reported that the intensity method gives lower values of the sound reduction index than the conventional method at low frequencies and higher at high frequencies. The purpose of this paper is to demonstrate with experimental data that excellent agreement between the two methods can be obtained in a fairly wide frequency range (80 Hz-6.3 kHz), provided that the measurements are carried out under optimum conditions. As pointed out by several authors, the only reason for systematic deviations between the two methods is the effect of having a partition that is highly absorbing in the receiving room.
Flightlessness and phylogeny amongst endemic rails (Aves: Rallidae) of the New Zealand region
Authors: Trewick S. A. 
Published: October 2002

The phylogenetic relationships of a number of flightless and volant rails have been investigated using mtDNA sequence data. The third domain of the small ribosomal subunit (12S) has been sequenced for 22 taxa, and part of the 5′ end of the cytochrome–bgene has been sequenced for 12 taxa. Additional sequences were obtained from outgroup taxa, two species of jacana, sarus crane, spur–winged plover and kagu. Extinct rails were investigated using DNA extracted from subfossil bones, and in cases where fresh material could not be obtained from other extant taxa, feathers and museum skins were used as sources of DNA.Phylogenetic trees produced from these data have topologies that are, in general, consistent with data from DNA–DNA hybridization studies and recent interpretations based on morphology.Gallinula chloropus(moorhen) groups basally withFulica(coots),Amaurornis(=Megacrex)ineptusfalls within theGallirallus/Rallusgroup, andGallinula(=Porphyrula)martinicais basal toPorphyrio(swamphens) and should probably be placed in that genus. Subspecies ofPorphyrio porphyrioare paraphyletic with respect toPorphyrio mantelli(takahe). The Northern HemisphereRallus aquaticusis basal to the south–western PacificRallus(orGallirallus) group. The flightlessRallus philippensis dieffenbachiiis close toRallus modestusand distinct from the volantRallus philippensis, and is evidently a seperate species.Porzana(crakes) appears to be more closely associated withPorphyriothanRallus. Deep relationships among the rails remain poorly resolved.Rhynochetos jubatus(kagu) is closer to the cranes than the rails in this analysis.Genetic distances between flightless rails and their volant counterparts varied considerably with observed 12S sequence distances, ranging from 0.3 % (Porphyrio porphyrio melanotusandP. mantelli mantelli) to 7.6 % (Rallus modestusandRallus philippensis). This may be taken as an indication of the rapidity with which flightlessness can evolve, and of the persistence of flightless taxa. Genetic data supported the notion that flightless taxa were independently derived, sometimes from similar colonizing ancestors. The morphology of flightless rails is apparently frequently dominated by evolutionary parallelism although similarity of external appearance is not an indication of the extent of genetic divergence. In some cases, taxa that are genetically close are morphologically distinct from one another (e.g.Rallus (philippensis) dieffenbachiiandR. modestus), whilst some morphologically similar taxa are evidently independently derived (e.g.Porphyio mantelli hochstetteriandP. m. mantelli).
Quantification in tissue near–infrared spectroscopy
Authors: Delpy D. T. , Cope M. 
Published: October 2002

In near–infrared spectroscopy (NIRS) of tissue, light attenuation is due to: (i) absorption from chromophores of fixed concentration, (ii) absorption from chromophores of variable concentration, and (iii) light scatter. NIRS is usually concerned with trying to quantify the concentrations of chromophores in category (ii), in particular oxy– and deoxyhaemoglobin (HbO2and Hb) and cytochrome oxidase.In the absence of scatter the total light absorption in the medium is a linear sum of that due to each chromophore. In a scattering medium like tissue, this linear summation is distorted because the optical path length at each wavelength may differ. This distorted spectrum is then superimposed upon a further wavelength–dependent attenuation arising from light loss due to scatter, which is a complex function of the tissue absorption and scattering coefficients (μaandμs), scattering phase function, and tissue and measurement geometry. Consequently, quantification of NIRS data is difficult.Over the past 20 years many differing approaches to quantification have been tried. The development of methods for measuring optical path length in tissue initially enabled changes in concentration to be quantified, and subsequently methods for absolute quantification of HbO2and Hb were developed by correlating NIRS changes with an independent measurement of arterial haemoglobin saturation. Absolute determination of tissue optical properties, however, requires additional information over and above the detected intensity at the tissue surface, which must then be combined with a model of light transport to deriveμaandμs. The additional data can take many forms, e.g. the change in intensity with distance, the temporal dispersion of light from an ultrashort input light pulse, or phase, and modulation depth changes of intensity–modulated light. All these approaches are now being actively pursued with considerable success. However, all the approaches are limited by the accuracy of the light transport models, especially in inhomogeneous media.
Localized near–infrared spectroscopy and functional optical imaging of brain activity
Authors: Tamura Mamoru , Hoshi Yoko , Okada Fumihiko 
Published: October 2002

Changes in cerebral blood flow (CBF) and cerebral metabolic rates (CMRO2) have been used as indices for changes in neuronal activity. Near–infrared spectroscopy (NIRS) can also measure cerebral haemodynamics and metabolic changes, enabling the possible use of multichannel recording of NIRS for functional optical imaging of human brain activity. Spatio–temporal variations of brain regions were demonstrated during various mental tasks. Non–synchronous behaviour of cerebral haemodynamics during the neuronsl activation was observed. Gender– and handedness–dependent lateralization of the function between right and left hemispheres was demonstrated by simultaneous measurement using two NIR instruments during the mirror–drawing task. A lack of interhemispheric integration was observed with schizophrenic patients. These observations suggest an application for NIRS in psychiatric disease management, as an addition to clinical monitoring at the bedside.A time–resolved 64–channel optical imaging system was constructed. This consisted of three picosecond laser diodes and 64 channels of TAC and CFD systems. Image reconstruction for phantom model systems was performed. Time–resolved quantitative optical imaging will become real in the very near future.
Potential and attainable food production and food security in different regions
Authors: De Vries F.W. T. Penning , Rabbinge R. , Groot J. J. R. 
Published: October 2002

Growing prosperity in the South is accompanied by human diets that will claim more natural resources per capita. This reality, combined with growing populations, may raise the global demand for food crops two– to four–fold within two generations. Considering the large volume of natural resources and potential crop yields, it seems that this demand can be met smoothly. However, this is a fallacy for the following reasons. (i) Geographic regions differ widely in their potential food security: policy choices for agricultural use of natural resources are limited in Asia. For example, to ensure national self–sufficiency and food security, most of the suitable land (China) and nearly all of the surface water (India) are needed. Degradation restricts options further. (ii) The attainable level of agricultural production depends also on socio–economic conditions. Extensive poverty keeps the attainable food production too low to achieve food security, even when the yield gap is wide, as in Africa. (iii) Bio–energy, non–food crops and nature ‘compete’ with food crops for natural resources.
Global and regional food security are attainable, but only with major efforts. Strategies to achieve alternative aims will be discussed.
Meeting water requirements of an expanding world population
Authors: Falkenmark Malin 
Published: October 2002

Water availability in the root zone (‘green water’) is a critical component of plant production, but is often deficient in many Third World regions. When deficient, runoff water (‘blue water’) can be added. Focusing on ten physiographic regions in Africa and Asia, characterized by mainly or partly dry climates and rapid population growth, this study analyses whether in a 30–years' perspective enough blue water could be provided to allow food self–sufficiency. It is assumed that for food self–sufficiency some 900 cubic metres of water per person per year has to be provided. In judging the realism it is assumed that a maximum 25 per cent increase in water mobilization	rate would be manageable in a 30–year period. The study suggests that by 2025, water scarcity will make regions populated by some 55 % of the world's population dependent on food imports. For water–wasting regions in Central Asia, water saving might, however, free the water needed. The paper closes by proposing some urgent measures.
Inhibition of the Plastidic ATP/ADP Transporter Protein Primes Potato Tubers for Augmented Elicitation of Defense Responses and Enhances Their Resistance against Erwinia carotovora
Authors: Linke Christoph , Conrath Uwe , Jeblick Wolfgang , Betsche Thomas , Mahn Andreas , Düring Klaus , Neuhaus H. Ekkehard 
Published: October 2002

Abstract
Tubers of transgenic potato (Solanum tuberosum) plants with decreased activity of the plastidic ATP/ADP transporter AATP1 display reduced levels of starch, modified tuber morphology, and altered concentrations of primary metabolites. Here, we demonstrate that the spontaneous production of hydrogen peroxide, the endogenous content of salicylic acid, and the levels of mRNAs of various defense-related genes are similar in tuber discs of wild-type and AATP1(St) antisense plants. However, upon challenging the tissue with fungal elicitors or culture supernatants of the soft rot-causing pathogenErwinia carotovora subsp. atroseptica, the AATP1(St) antisense tubers exhibit highly potentiated activation of defense responses when compared with wild-type tissue. The augmented defense responses comprise enhanced accumulation of transcripts of five defense-related genes (β-1,3-GLUCANASE B2 andA1, CHITINASE B3 and A2, and Phe AMMONIA-LYASE) and enhanced elicitation (up to 21-fold) of the early hydrogen peroxide burst. The potentiated activation of cellular defense responses inAATP1(St) antisense tubers is not accompanied by a precedent increase in endogenous salicylic acid levels, but is associated with a strongly enhanced resistance of the tissue to E. carotovora. From these results, we conclude that inhibition of primary metabolic reactions induces a primed state that sensitizes the potato tubers for improved elicitation of various cellular defense responses, which likely contribute to enhancedE. carotovora resistance.
The Role of Auxin, pH, and Stress in the Activation of Embryogenic Cell Division in Leaf Protoplast-Derived Cells of Alfalfa
Authors: Pasternak Taras P. , Prinsen Els , Ayaydin Ferhan , Miskolczi Pál , Potters Geert , Asard Han , Van Onckelen Harry A. , Dudits Dénes , Fehér Attila 
Published: October 2002

Abstract
Culturing leaf protoplast-derived cells of the embryogenic alfalfa (Medicago sativa subsp. varia A2) genotype in the presence of low (1 μm) or high (10 μm) 2, 4-dichlorophenoxyacetic acid (2,4-D) concentrations results in different cell types. Cells exposed to high 2,4-D concentration remain small with dense cytoplasm and can develop into proembryogenic cell clusters, whereas protoplasts cultured at low auxin concentration elongate and subsequently die or form undifferentiated cell colonies. Fe stress applied at nonlethal concentrations (1 mm) in the presence of 1 μm2,4-D also resulted in the development of the embryogenic cell type. Although cytoplasmic alkalinization was detected during cell activation of both types, embryogenic cells could be characterized by earlier cell division, a more alkalic vacuolar pH, and nonfunctional chloroplasts as compared with the elongated, nonembryogenic cells. Buffering of the 10 μm 2,4-D-containing culture medium by 10 mm2-(N-morpholino)ethanesulfonic acid delayed cell division and resulted in nonembryogenic cell-type formation. The level of endogenous indoleacetic acid (IAA) increased transiently in all protoplast cultures during the first 4 to 5 d, but an earlier peak of IAA accumulation correlated with the earlier activation of the division cycle in embryogenic-type cells. However, this IAA peak could also be delayed by buffering of the medium pH by 2-(N-morpholino)ethanesulfonic acid. Based on the above data, we propose the involvement of stress responses, endogenous auxin synthesis, and the establishment of cellular pH gradients in the formation of the embryogenic cell type.
Linamarase Expression in Cassava Cultivars with Roots of Low- and High-Cyanide Content
Authors: Santana Marı́a Angélica , Vásquez Valeria , Matehus Juan , Aldao Rafael Rangel 
Published: October 2002

Abstract
This paper reports the expression and localization of linamarase in roots of two cassava (Manihot esculentaCrantz) cultivars of low and high cyanide. Two different patterns of linamarase activity were observed. In the low-cyanide type, young leaves displayed very high enzyme activity during the early plant growing stage (3 months), whereas in root peel, the activity increased progressively to reach a peak in 11-month-old plants. Conversely, in the high-cyanide cultivar (HCV), root peel linamarase activity decreased during the growth cycle, whereas in expanded leaves linamarase activity peaked in 11-month-old plants. The accumulation of linamarin showed a similar pattern in both cultivars, although a higher concentration was always found in the HCV. Linamarase was found mainly in laticifer cells of petioles and roots of both cultivars with no significant differences between them. At the subcellular level, there were sharp differences because linamarase was found mainly in the cell walls of the HCV, whereas in the low-cyanide cultivar, the enzyme was present in vacuoles and cell wall of laticifer cells. Reverse transcriptase-PCR on cassava tissues showed no expression of linamarase in cassava roots, thus, the transport of linamarase from shoots to roots through laticifers is proposed.
The Expression of HAK-Type K+ Transporters Is Regulated in Response to Salinity Stress in Common Ice Plant
Authors: Su Hua , Golldack Dortje , Zhao Chengsong , Bohnert Hans J. 
Published: October 2002

Abstract
Four transcripts homologous to K+ transporters of the HAK/KT/KUP family have been characterized from the common ice plant (Mesembryanthemum crystallinum). We report tissue-specific expression of McHAK1 andMcHAK4 transcripts abundant in roots, leaves, and stems.McHAK2 was predominantly present in stems andMcHAK3 in root tissues. By in situ hybridizations, the McHAKs showed signals in the leaf vascular bundles, mesophyll, and epidermal cells as well as in epidermal bladder cells. In mature roots, transcripts were mainly localized to the vasculature, and in differentiated root tips, the strongest signals were obtained from the epidermis. Expression of McHAK1, McHAK2, and McHAK4 complemented a yeast mutant defective in low- and high-affinity K+ uptake. Growth of the yeast mutant was restored at low-millimolar K+ concentrations and was inhibited by Rb+ and Cs+ but was not affected by Na+. Transcript levels of McHAK1 andMcHAK4 increased by K+ starvation and by salt stress of 400 mm NaCl in leaves and roots. Expression of McHAK2 and McHAK3 was stimulated in leaves and was transiently induced in roots in response to high salinity with prestress transcript levels restored in salt-adapted plants. We discuss possible roles for such transporters in ion homeostasis at high salinity.