bluuebunny/crossref_metadata_2025_split huggingface dataset:
Solid Surface Enhancement Effects on Chemiluminescence. III. Diaryloxalate as Chemiluminescence Reagent and Inorganic Materials as Media Solids
Authors: Yoshinaga Tetsutaro , Tanaka Yasuo , Ichimura Teijiro , Hiratsuka Hiroshi , Hasegawa Miki , Kobayashi Michio , Hoshi Toshihiko 
Published: October 2002

Abstract
Solid surface enhancement effects on chemiluminescence were studied using many inorganic materials as solid media. The results has been classified as follows: the first group (G-1) which has higher initial intensities and shorter lifetimes compared with the reference chemiluminescence (blank CL; medium solid used is a slide glass)—Al2O3 series including hydroxides and glass fiber filter fall under this group (G-1); the second group (G-2) which has lower initial intensities and longer lifetimes compared with the blank CL—high purity CaCO3 fall under this group (G-2); the third group (G-3) which has higher initial intensities and longer lifetimes compared with the blank CL—SiO2 powder and a silica fiber filter fall under this group (G-3); and the fourth group (G-4) which has lower initial intensities and shorter lifetimes compared with the blank CL—all remaining solid media other than group (G-1)–(G-3) fall under this group (G-4). Furthermore, from a chemiluminescent energy point of view, there exists another group (G-5) which has higher relative luminescent energies or relative quantum yields than the blank one–all the compounds that belong to the group (G-3) and others in group (G-1) and group (G-2), i.e., silica powder (SW-CO type), silica fiber filter (QR-100 type), and high purity calcium carbonate (3N-D type) are members of this group (G-5). Effects of surface condition and particle size on chemiluminescence were also examined.
Fundamental mechanisms of the growth and decay of the PNA teleconnection pattern
Authors: Feldstein Steven B. 
Published: October 2002

AbstractThis investigation performs diagnostic analyses on NCEP/NCAR re‐analysis data, and also does forced, nonlinear, barotropic model calculations to examine the dynamical mechanisms associated with the growth and decay of the Pacific/North American teleconnection pattern (PNA). The diagnostic calculations include projection and composite analyses of each term in the stream‐function‐tendency equation.The results of the diagnostic analyses and model calculations reveal a PNA life cycle that is complete within approximately 2 weeks and is dominated by linear processes. The growth of the two upstream PNA anomaly centres is found to be by barotropic conversion from the zonally asymmetric climatological flow, and the two downstream PNA anomaly centres by linear dispersion. The PNA anomaly growth eventually ceases because of changes in the spatial structure of the anomaly. An analysis of the role of Ekman pumping is performed with a very simple model. The results, although qualitative, suggest that the decay of the PNA may be through Ekman pumping. An examination of the role of transient eddy vorticity fluxes indicates that they play an important role during some stages of the PNA life cycle. Lastly, the model calculations also reveal a crucial role played by the divergence term in maintaining the PNA anomaly in a quasi‐fixed position. Copyright © 2002 Royal Meteorological Society.
Equatorial waves in temperature in the altitude range 4 to 70 km
Authors: Murthy B. V. Krishna , Satheesan K. , Parameswaran K. , Sasi M. N. , Ramkumar Geetha , Bhavanikumar Y. , Raghunath K. , Krishniah M. 
Published: October 2002

AbstractUsing altitude profiles of temperature in the range 4 to 70 km derived from Mesosphere–Stratosphere–Troposphere radar and lidar observations at Gadanki (13.5°N,79.2°E) from 18 January 1999 to 5 March 1999, characteristics of equatorial waves are studied. Two‐dimensional Fourier‐transform analysis of the temperature profiles is carried out to identify the periodicities and their vertical wave numbers. From the characteristics obtained, equatorial slow Kelvin waves with periodicities 15.7 d, 9.4 d, 7.8 d and 6.7 d are identified in the troposphere and stratosphere regions and among these 7.8 d and 6.7 d periodicities are found to penetrate into the mesosphere. Equatorial waves with smaller periodicities in the range 5.2 d to 3.6 d are also observed. The vertical flux of horizontal momentum (zonal) of the identified slow Kelvin‐wave periodicities in the altitude region 4–25 km is estimated. It is found that equatorial waves modulate tropical tropopause temperature and altitude. Copyright © 2002 Royal Meteorological Society.
Chemically Activated Carbons from Olive Stones — Peculiarities of Pore Structure and Interpretation of Nitrogen Adsorption Data
Authors: Hourieh M.A. , Alaya M.N. , El-Sejariah F. , Youssef A.M. 
Published: October 2002

Chemically activated carbons were obtained from olive stones either by carbonization with H3PO4 at 300–600°C or by carbonization with ZnCl2 at 600°C. Nitrogen adsorption at 77 K was determined for all the activated carbons. The adsorption data were interpreted by considering some conventional adsorption models. Maximum activation with H3PO4 occurred at 450°C. However, the adsorption capacities of the ZnCl2-activated carbons were far higher than those of carbons activated with H3PO4. Carbons activated with H3PO4 or ZnCl2 are mainly microporous with the non-micropores representing a small fraction of the total porosity. Although, the nitrogen isotherms are Langmuirian in shape, application of the Langmuir equation led to large monolayer capacities of uncertain confidence. The surface areas and micropore volumes determined by the application of the t-method of de Boer and the αS-method of Sing were comparable and were slightly higher than those determined by the application of the DR model based on micropore filling. The t-method and the αS-method are complementary to each other and would seem to give confident values because they are based on standard reference non-porous materials. The micropore region may be sub-divided into two sub-regions distinguished by the different filling mechanisms involved.
Physicochemical and Catalytic Properties of Vanadia/Titania Catalysts. I. Structural Properties
Authors: El-Nabarawy Th. , Youssef A.M. , Ahmed S.A. Sayed 
Published: October 2002

Titania gels Ta and Tb were precipitated from TiCl4 at pH 3.0 and 9.0, respectively, using ammonia solution. Calcination products were obtained by the thermal treatment of the gels at 300, 400, 600, 750 and 1000°C, respectively. Thermal analysis, X-ray diffraction and FT-IR spectroscopy demonstrated that the anatase → rutile transformation commenced when Ta was calcined at 400°C, with the rutile form predominating when calcination was conducted at 600°C. Calcination at 750°C or 1000°C was associated with complete anatase → rutile conversion. The calcination product of Tb at 400°C was pure anatase, transformation to rutile taking place above this temperature and predominating at 600°C. Rutile was the sole phase present when Tb was calcined at 750°C. Vanadia/titania catalysts were obtained by impregnating Ta and Tb with an aqueous solution of NH4VO4 of concentration sufficient to obtain samples containing 4.0, 6.0, 8.0 or 12.0 wt% V2O5. The calcination products at 400°C and 600°C were characterized by thermal analysis, X-ray diffraction, FT-IR spectroscopy, electronic spectral analysis and magnetic susceptibility measurements. The presence of vanadium enhanced the anatase → rutile transformation. The measured X-ray diffraction lines and FT-IR peaks indicated the existence of vanadium as a separate oxide, mainly V2O5. However, the electronic spectra and magnetic susceptibility measurements predicted the possible existence of a V4+ species.
Surface and Catalytic Properties of the Co3O4/MgO System Doped with Fe2O3
Authors: El-Shobaky H.G. , Shaheen W.M. , Mokhtar M. 
Published: October 2002

The surface and catalytic properties of pure and Fe2O3-doped Co3O4/MgO solids were investigated. The extent of loading was maintained at 38 wt% Co3O4 and the amount of dopant varied between 1.2 wt% and 11.0 wt% Fe2O3. The pure and doped solids were prepared by calcination at 400–1000°C of pure and ferric nitrate-treated magnesium carbonate impregnated with cobalt nitrate solution. The samples thus obtained were examined by TG, DTA and XRD methods, nitrogen adsorption studies at −196°C and the catalysis of H2O2 decomposition at 30–50°C. The results revealed that Fe2O3 treatment of the Co3O4/MgO system followed by calcination at 400°C resulted in an increase in the particle size of the Co3O4 and MgO phases, whilst the opposite effect was observed when the doped solids were calcined at 600°C. Doping of the Co3O4/MgO system followed by calcination at 400°C effected a measurable decrease in its BET surface area with the reverse effect being observed upon heating at 600°C. An increase in the calcination temperature of pure Co3O4/MgO up to 800°C brought about an abrupt decrease in the intensity of all the diffraction lines associated with the Co3O4 phase. These disappeared completely upon heating the system at 900°C or 1000°C due to dissolution of the cobalt oxide in the MgO lattice to form a solid solution. A cobalt ferrite phase was detected in the variously doped solids calcined at 800–1000°C even when the initial solids had been treated with 2.4 wt% Fe2O3. This finding suggests that most of the ferrite phase produced was contained in the outermost surface layers of the treated samples. Treatment of the investigated system with Fe2O3 followed by calcination at 400°C and 800°C led to a progressive decrease in the catalytic activity of the resulting solid due to an increase in the particle size (a decrease in the degree of dispersion) of the catalytically-activeconstituent, i.e. the Co3O4 phase, and due to the conversion of Co3O4 into a CoFe2O4 phase, respectively. In contrast, doping followed by calcination at 600°C led to an increase in the catalytic activity of the resulting solid due to an effective decrease in the particle size of the Co3O4 phase. Calcination of the Fe2O3-doped system at 400–800°C did not modify the mechanism of the catalyzed reaction but changed the concentration of active sites without changing their energetic nature.
Multiparametered Formfinding Method: Application to Tensegrity Systems
Authors: Vassart N. , Motro R. 
Published: October 2002

A method allowing a multiparametered formfinding for prestressed and selfstressed reticulated systems with tensile and compressive members is presented. Known methods, based on geometric analysis and dynamic (dynamic relaxation) considerations have been developed for these systems but they allow generally the evolution of only one parameter. But, in case of shape finding of non-regular new forms or when the sought-after form is subject to a set of geometrical constraints, it becomes obligatory to elaborate a multiparametered form-finding process. The proposed numerical method, which is described in this paper, exploits the force density method, already used for form finding of pure tensile structures. However, equilibrium matrix of pure tensile structures as cable nets systems, admits always an inverse, which might be false when tensile and compressive members coexist in the system. In this paper, different processes allowing to define prestressed (or selfstressed) equilibrium geometry are described. Except for the relational structure which is considered as known at the beginning of the process, two sets of form-finding parameters can be identified for this method: prestress (or selfstress) coefficients of members and coordinates or redundant nodes. The proposed method does not yield a unique geometry but it is very convenient for a multiparametered formfinding, and has produced very interesting results, especially for Tensegrity Systems. Application of this method of multiparametered formfinding to Tensegrity Systems, provides the designer with an efficient way to achieve interesting new selfstressed geometries, such as the generation of double-layer grids by agglomeration of Tensegrity modules.
The American Wind Energy Associations Year 2000 Awards
Authors: de Azua Christine Real 
Published: October 2002

The AWEA announced several Award winners at the ‘Windpower 2000’ conference in Palm Springs, California. The winners received their awards from outgoing AWEA President Robert Gates. Walt Musial and Sandy Butterfield, both of the National Wind Technology Center, jointly won the Technical Achievement Award. Musial and the National Wind Technology Center test team were honored “for developing a capability at the National Wind Technology Center to provide blade and drive train structural component testing to the U.S. wind industry”. Butterfield was recognized “for successfully overseeing development of a U.S.-based certification program.” The National Wind Technology Center (NWTC) is situated in a spectacular setting at the foot of the Rocky Mountains, in the Rocky Flats Environmental Technology Site buffer zone in Golden, Colorado. A few turbines of varying sizes and models can be glimpsed on the open plateau from Route 128 out of Golden. However the small number of turbines belies the importance of this center for the wind power industry. Most of the NWTC's work is carried out indoors, in hangars and computer labs which make it one of the world's unique testing centers.
Clean Development Mechanism for Power Infrastructures for China's Sustainable Development
Authors: Deshun Liu , Sugiyama Taishi 
Published: October 2002

What is the Clean Development Mechanism (CDM)? The establishment of Clean Development Mechanism (CDM) is a significant achievement in the political negotiations on the implementation of United Nations Framework Convention on Climate Change (UNFCCC). CDM is stipulated in Article 12 of the Kyoto Protocol (KP), where assisting developing country Parties in achieving sustainable development is explicitly listed as a purpose in parallel with the others. Developed country Parties are to be assisted in achieving compliance with their quantified emission limitation and reduction commitment (QELRC) under Article 3 by acquiring Certified Emission Reductions (CERs) accrued from the CDM. This win-win mechanism reflects two arguments: the responsibility of developed countries for past greenhouse gas emissions, and the legitimate priority needs of developing countries for their social and economic development and poverty eradication. It should be kept in mind, therefore, that when formulating the strategic policy of the CDM, one important principle to be followed is that CDM projects must be compatible with and supportive of national environments and sustainable development priorities and strategies of developing country Parties.
Measurements of tissue viability in transplantation
Authors: Thorniley M. S. , Simpkin S. , Balogun E. , Khaw K. , Shurey C. , Burton K. , Green C. J. 
Published: October 2002

Near–infrared spectroscopy has primarily been used in monitoring changes in cerebral haemoglobin oxygenatiuon and haemodynamics. However its use as a method for the assessment of tissue viability following transplantation has recently been explored experimentally in our laboratory.
The ability to measure changes in oxygenation and perfusion during harvesting and following transplantation of organs or transfer of free and pedicled flaps is potentially important in reconstructive surgery. We have found that near–infrared spectroscopy is extremely useful in detecting vaso–occlusive events and can accurately and reliably distinguish between arterial, venous or total occlusions. Venous congestion indicated by raised levels of deoxygenated haemoglobin with a concomitant increase in blood volume and the presence and magnitude of reactive hyperaemia are both easily recognizable features by near–infrared spectroscopy. We have shown that near–infrared spectroscopy measurements of venous congestion in kidneys (and other tissues) following prolonged storage correlate with medullary vascular congestion confirmed by angiographical and histological analysis of intrarenal perfusion.
Clinically we have shown that flap perfusion can be improved by altering fluid replacement regimes and the addition of ionotropes. Cerebral near–infrared spectroscopy measurements in a liver transplant model showed statistically significant differences within minutes after the anhepatic phase in cerebral perfusion and oxygenation, between animals transplanted with ischaemically damaged livers compared to those isografted with minimally stored livers. Similarly we have found that near–infrared spectroscopy can be used as a monitor to assess the adequacy of fluid or blood replacement in haemorrhagic and hypovolaemic models. We believe that near–infrared spectroscopy provides a sensitive and reliable postoperative method for the assessment of tissue viability following the transfer of free and pedicled flaps and organs.
Cerebral haemoglobin oxygenation during sustained visual stimulation – a near–infrared spectroscopy study
Authors: Heekeren H. R. , Obrig H. , Wenzel R. , Eberle K. , Ruben J. , Villringer K. , Kurth R. , Villringer A. 
Published: October 2002

Using near–infrared spectroscopy, we investigated the time–course of the concentrations of oxygenated haemoglobin, [oxy–Hb], and deoxygenated haemoglobin, [deoxy–Hb], in the occipital cortex of healthy human adults during sustained visual stimulation. Within a few seconds after stimulation (coloured dodecahedrons) we observed a decrease in [deoxy–Hb], peaking after 13 s (‘initial undershoot’). In the subsequent 1–2 min, in seven out of ten subjects, [deoxy–Hb] gradually returned to a plateau closer to the baseline level. After cessation of stimulation, there was a ‘post–stimulus overshoot’ in the concentration of deoxyhaemoglobin. There was a statistically significant correlation between the size of the ‘initial undershoot’ and the ‘post–stimulus overshoot’.The concentration of oxyhaemoglobin increased upon functional activation. However, in the mean across all subjects there was no initial overshoot. After approximately 19 s it reached a plateau and remained constantly elevated throughout the activation period. After cessation of activation there was a ‘post–stimulus undershoot’ of oxyhaemoglobin.It is important to consider the time–course of haemoglobin oxygenation when interpreting functional activation data, especially those data obtained with oxygenation–sensitive methods, such as BOLD contrast fMRI.
Ageing and physiological functions
Authors: Young Archie 
Published: October 2002

In youth, most physiological functions have generous spare capacity. Even in health, however, increasing age is characterized by progressive erosion of these ‘safety margins’. Examples include the decline of bone mass (towards a threshold for likelihood of fracture), of glomerular filtration rate (towards a threshold for susceptibility to clinical renal failure), of renal tubular function (towards a threshold for clinically important susceptibility to dehydration), of hepatic function (towards a thresholds for accumulation following conventional ‘young adult’ doses of common medications), or of lower limb explosive power (towards thresholds for impaired functional mobility).
Increasing age is also characterized by a rising prevalence of chronic pathologies, complicating attempts to determine the rate or the mechanism of the age–related decline in a physiological function. Nevertheless, it is clear that in many organs the loss of function is largely attributable to the loss of functioning cells, even in the absence of overt disease. This apparently fundamental aspect of ageing remains poorly understood.
Fatty Acid Export from the Chloroplast. Molecular Characterization of a Major Plastidial Acyl-Coenzyme A Synthetase from Arabidopsis
Authors: Schnurr Judy A. , Shockey Jay M. , de Boer Gert-Jan , Browse John A. 
Published: October 2002

Abstract
Acyl-coenzyme A (CoA) synthetases (ACSs, EC 6.2.1.3) catalyze the formation of fatty acyl-CoAs from free fatty acid, ATP, and CoA. Essentially all de novo fatty acid synthesis occurs in the plastid. Fatty acids destined for membrane glycerolipid and triacylglycerol synthesis in the endoplasmic reticulum must be first activated to acyl-CoAs via an ACS. Within a family of nine ACS genes from Arabidopsis, we identified a chloroplast isoform,LACS9. LACS9 is highly expressed in developing seeds and young rosette leaves. Both in vitro chloroplast import assays and transient expression of a green fluorescent protein fusion indicated that the LACS9 protein is localized in the plastid envelope. A T-DNA knockout mutant (lacs9-1) was identified by reverse genetics and these mutant plants were indistinguishable from wild type in growth and appearance. Analysis of leaf lipids provided no evidence for compromised export of acyl groups from chloroplasts. However, direct assays demonstrated thatlacs9-1 plants contained only 10% of the chloroplast long-chain ACS activity found for wild type. The residual long-chain ACS activity in mutant chloroplasts was comparable with calculated rates of fatty acid synthesis. Although another isozyme contributes to the activation of fatty acids during their export from the chloroplast, LACS9 is a major chloroplast ACS.
ACTIN2 Is Essential for Bulge Site Selection and Tip Growth during Root Hair Development of Arabidopsis
Authors: Ringli Christoph , Baumberger Nicolas , Diet Anouck , Frey Beat , Keller Beat 
Published: October 2002

Abstract
Root hairs develop as long extensions from root epidermal cells. After the formation of an initial bulge at the distal end of the epidermal cell, the root hair structure elongates by tip growth. Because root hairs are not surrounded by other cells, root hair formation provides an excellent system for studying the highly complex process of plant cell growth. Pharmacological experiments with actin filament-interfering drugs have provided evidence that the actin cytoskeleton is an important factor in the establishment of cell polarity and in the maintenance of the tip growth machinery at the apex of the growing root hair. However, there has been no genetic evidence to directly support this assumption. We have isolated an Arabidopsis mutant, deformed root hairs 1 (der1), that is impaired in root hair development. The DER1locus was cloned by map-based cloning and encodes ACTIN2 (ACT2), a major actin of the vegetative tissue. The three der1alleles develop the mutant phenotype to different degrees and are all missense mutations, thus providing the means to study the effect of partially functional ACT2. The detailed characterization of theder1 phenotypes revealed that ACT2 is not only involved in root hair tip growth, but is also required for correct selection of the bulge site on the epidermal cell. Thus, the der1mutants are useful tools to better understand the function of the actin cytoskeleton in the process of root hair formation.