bluuebunny/crossref_metadata_2025 huggingface dataset:
The impact of El Niño–southern oscillation upon weather regimes over Europe and the North Atlantic during boreal winter
Authors: Moron Vincent , Plaut Guy
Published: March 2003

The influence of the warm and cold sea‐surface temperatures in the eastern and central equatorial Pacific associated with El Niño–southern oscillation (ENSO) on the probability of occurrence of weather regimes (WRs) over the North Atlantic sector is investigated for the period November–March. Five WRs are identified from daily sea‐level pressure anomalies (SLPAs) during 119 winters (1882–2000) over this sector by applying cluster analysis: the positive North Atlantic oscillation (NAO; called ZO for zonal) and negative NAO (called WBL for west blocking) patterns; GA (for Greenland anticyclone), with a positive SLPA shifted north of 60° N; EA (for European anticyclone) with a positive SLPA over Europe but enhanced north–south SLPA gradient over the western and central North Atlantic; and AR (for Atlantic Ridge) with a positive (negative) SLPA over the central North Atlantic (northern and central Europe).

El Niño winters are associated with a significant increase (decrease) in the prevalence of ZO (WBL) in November–December and a significant increase (decrease) in the prevalence of GA and WBL (EA and ZO) in January–March. During La Niña winters, ZO (WBL and AR) occurs significantly less (more) frequently in November–December, and GA and WBL (EA and AR) are less (more) frequent in January–March. So, the anomalies of the WR frequencies are almost inverted between November–December and January–March. The response of the WR frequencies to ENSO extremes is most pronounced in February.

On the inter‐ and multi‐decadal time scales, the typical ENSO signals tend to be stronger during preferred phases of the basinwide westerlies, especially in January–March. The typical El Niño signal in January–March (e.g. more GA and WBL and less ZO and EA than normal) is strong when westerlies are slower than normal, around 1900, 1915 and mainly from 1930 to 1970. The generally reversed association during La Niña winters (e.g. more EA and AR and less GA and WBL than normal) in January–March is strong mainly when westerlies are faster than normal. Anomalies are weaker and quite different during ‘slow westerlies–La Niña’ and ‘fast westerlies–El Niño’ January–March winters. Such a modulation also appears in November–December with reversed association (i.e. stronger ENSO signal during ‘slow westerlies–La Niña’ and ‘fast westerlies–El Niño’ November–December winters), but the difference between the slow and fast westerlies phases is weaker than in January–March. Copyright © 2003 Royal Meteorological Society
Ice core and palaeoclimatic evidence for the timing and nature of the great mid‐13th century volcanic eruption
Authors: Oppenheimer Clive
Published: March 2003

Ice cores from both the Arctic and Antarctic record a massive volcanic eruption in around AD 1258. The inter‐hemispheric transport of ash and sulphate aerosol suggests a low‐latitude explosive eruption, but the volcano responsible is not known. This is remarkable given estimates of the magnitude of the event, which range up to 5 × 1014–2 × 1015 kg (∼200–800 km3 of dense magma), which would make this the largest eruption of the historic period, and one of the very largest of the Holocene. The associated collapse caldera could have had a diameter up to 10–30 km. Palaeoclimate reconstructions indicate very cold austral and boreal summers in AD 1257–59, consistent with known patterns of continental summer cooling following tropical, sulphur‐rich explosive eruptions. This suggests an eruption in AD 1257, producing a stronger climate forcing than hitherto recognized. Copyright © 2003 Royal Meteorological Society
Estimation of transboundary air pollution on the basis of synoptic‐scale weather types
Authors: Helmis C. G. , Moussiopoulos N. , Flocas H. A. , Sahm P. , Assimakopoulos V. D. , Naneris C. , Maheras P.
Published: March 2003

A methodology to estimate annual transboundary atmospheric transport is proposed, taking into account different background meteorological conditions. For this purpose, the 850 hPa synoptic‐scale atmospheric circulation over the area examined was classified on a daily basis into 14 distinct synoptic types, using a database for an extended period of 40 years. The corresponding frequency of appearance of the synoptic types for a normal year was calculated. For selected days representing the synoptic types during this year, the inflow–outflow fluxes of NOx and SO2 were estimated through a balancing box with the aid of a MEMO/TRAPPA modelling system. According to the proposed method, the total inflow–outflow fluxes were calculated using the lateral fluxes for each representative day, being weighted by the annual relative frequency of appearance of the synoptic scale weather types. It was demonstrated that this approach provides similar results to the intensive method based on day‐by‐day calculations. Furthermore, this approach is easier to use, since it is based on the simulations of selected days, and it allows the investigation of the influence of different types of atmospheric circulation on the inflow–outflow budget. Copyright © 2003 Royal Meteorological Society
Sea‐level pressure observations from Dutch ships 1854–1938 incorporated in COADS Release 1c climatology
Authors: Wallbrink H. , Koek F. , Können G. P. , Brandsma T.
Published: March 2003

The quality of the 5.7 million punched sea‐level pressure observations from Dutch ships for 1854–1938 has been under debate due to ambiguities in the gravity correction. The observations were omitted from the 1985 COADS (Comprehensive Ocean–Atmosphere Data Set) Release 1 monthly summaries. We re‐examined the Dutch data with the help of original meteorological ship logs. It is concluded that the Dutch procedure for pressure reduction was consistent throughout time. The Dutch data are incorporated in the recent (2001) COADS Release 1c. This increases the number of COADS pressure observations for 1854–1938 by about 28%. For the 1854–80 subperiod the increase is more than a factor two. Copyright © 2003 Royal Meteorological Society
Antioxidant actions and phenolic and vitamin C contents of common Mauritian exotic fruits
Authors: Luximon‐Ramma Amitabye , Bahorun Theeshan , Crozier Alan
Published: March 2003

Seventeen commonly consumed exotic fruits from Mauritius were analysed for their antioxidant capacity, total phenolics, proanthocyanidins, flavonoids and vitamin C content. Two independent methods were used to evaluate the antioxidant potential of total fruit extracts. The antioxidant activities of the fruits ranged from 1 to 47 µmol Trolox equivalent antioxidant capacity (TEAC) g−1 fresh weight and from 0.3 to 34 micro/mol g fresh weight (FRAP) g−1 fresh weight. Total phenolics in the fruits ranged from 118 to 5638 µg g−1 fresh weight, proanthocyanidins from 7 to 2561 µg g−1 fresh weight, flavonoids from 21 to 712 µg g−1 fresh weight and vitamin C content from 8 to 1426 µg g−1 fresh weight. There were strong correlations between antioxidant activity (assessed by both TEAC and FRAP) and total phenolics and proanthocyanidins. Flavonoids seemed to contribute less to the antioxidant potential of the fruits, while very poor correlations were observed between ascorbate content and antioxidant activity. The highest antioxidant capacities were observed in red and yellow Psidium cattleianum Sabine ‘Chinese guava’, sweet and acid Averrhoa carambola L ‘starfruit’, Syzygium cumini L Skeels ‘jamblon’ and white Psidium guajava L ‘guava’. These fruits were also characterised by high levels of total phenolics. Mauritian exotic fruits are thus a significant source of phenolic antioxidants, which may have potential beneficial effects on health. Copyright © 2003 Society of Chemical Industry
Effects of environmental factors and agricultural techniques on antioxidantcontent of tomatoes
Authors: Dumas Yvon , Dadomo Mario , Di Lucca Giuseppe , Grolier Pascal
Published: March 2003

Antioxidants are believed to be important in the prevention of diseases such as cancer and cardiovascular disease. Lycopene is one of the main antioxidants to be found in fresh tomatoes and processed tomato products. The lycopene content also accounts for the redness of the fruit, which is one of the main qualities for which industry and consumers now look. Other carotenes (such as β‐carotene), vitamin C, vitamin E and various phenolic compounds are also thought to be health‐promoting factors with antioxidant properties. Since the antioxidant content of tomatoes may depend on genetic factors, the choice of variety cultivated may affect the results at harvest. To be able to control the antioxidant content of tomatoes at the field level when growing a given variety, it is necessary to know the effects of both environmental factors and the agricultural techniques used. Temperatures below 12 °C strongly inhibit lycopene biosynthesis and temperatures above 32 °C stop this process altogether. The effects of the temperature on the synthesis of other antioxidants have not yet been properly assessed. The effects of light have been studied more thoroughly, apart from those on vitamin E. The effects of water availability, mineral nutrients (nitrogen, phosphorus, potassium and calcium) and plant growth regulators have been studied, but results are sometimes contradictory and the data often incomplete. During the ripening period, lycopene content of tomatoes increases sharply from the pink stage onwards, but no sufficient attempts have been made so far to assess the changes in the other antioxidants present in the fruit. This paper reviews the present state of the art. Copyright © 2003 Society of Chemical Industry
Effect of tannic acid on in vitro enzymatic hydrolysis of some protein sources
Authors: Martínez Tomás F , Moyano Francisco J
Published: March 2003

The pH‐stat system has been used to assess the effect of tannic acid (TA) on solubility and in vitro enzyme hydrolysis of different proteins. Added TA (from 10 to 50 g kg−1) decreased the extent of hydrolysis of bovine serum albumin. Enzymic hydrolysis of casein, pea meal, soybean meal, and haemoglobin (HB) was increased, as measured by total amino acids released and by the degree of hydrolysis. SDS‐PAGE confirmed the results of the in vitro enzymatic hydrolysis. These findings suggest that, under in vitro conditions, when simulating the gastrointestinal environment of domestic mammals, the negative effects of TA described from in vivo experiments are not necessarily due to reduced hydrolysis of proteins. Copyright © 2003 Society of Chemical Industry
Sorghum kafirin interaction with various phenolic compounds
Authors: Emmambux Naushad M , Taylor John RN
Published: March 2003

The ability of various phenolic compounds to bind and precipitate kafirin, the prolamin protein of sorghum, was investigated with regard to effects on its nutritional and functional uses. The protein–phenolic compound interaction was quantified by haze formation and colorimetric determination of total polyphenol bound. Ferulic acid, catechin and extracted phenolics (flavonoids) from condensed tannin‐free sorghum did not complex kafirin. Only tannic acid and sorghum‐condensed tannins had the ability to complex kafirin. The sorghum‐condensed tannins interacted more strongly than tannic acid. The haze of sorghum‐condensed tannins–kafirin was permanent, indicating a strong interaction. The fact that sorghum‐condensed tannins can bind irreversibly to kafirin indicates that this may play a role in decreasing protein digestibility in high‐tannin sorghum and can cause haze formation in lager beer made from high‐tannin sorghum. However, in condensed tannin‐free sorghum, phenolic compounds may not appear to play a major role in decreasing protein digestibility, as these endogenous phenolics may not bind with kafirin. Copyright © 2003 Society of Chemical Industry
Chemical and physicochemical properties of dried wet masa and dry masa flour
Authors: Bello‐Pérez Luis A , Osorio‐Díaz Perla , Agama‐Acevedo Edith , Solorza‐Feria Javier , Toro‐Vázquez Jorge F , Paredes‐López Octavio
Published: March 2003

Commercial ‘masas’ and dry ‘masa’ flours (DMFs) were evaluated for chemical composition, water retention capacity (WRC), gelatinization, retrogradation and X‐ray diffraction. Both masas and DMF had similar chemical compositions. The masas had higher soluble carbohydrate contents and lower WRCs than DMF. In the same way, DMFs had lower gelatinization temperatures and enthalpies of gelatinization than masas. These results were confirmed by X‐ray diffraction analysis showing a lower degree of crystallinity in DMFs than in masas. The melting temperature in retrogradated samples of both masas and DMFs had a tendency to increase as storage time increased. This increment was more apparent with the enthalpy of melting. These results were probably associated with crystal perfection during starch retrogradation, ie recrystallization of gelatinized starch occurred as a time‐dependent process. Copyright © 2003 Society of Chemical Industry
Short‐term in vivo digestibility assessment of a highly oxidized and polymerized sunflower oil
Authors: González‐Muñoz M José , Bastida Sara , Sánchez‐Muniz Francisco J
Published: March 2003

The aim of this study was to test the in vivo digestibility of a highly polymerized sunflower oil. The true digestibility of both the unheated oil and of an oil heated at frying temperature (180 °C) for 50 h in the presence of air was determined by using a 4 h in vivo test after applying the oil by an oesophageal probe to Wistar rats followed by high‐performance exclusion chromatography analysis of the luminal remaining fat. The true digestibility coefficient of the heated oil did not change significantly with respect to the unheated oil, although it tended to decrease (p < 0.1; 38%). The true digestibility of polymers, dimers, and total oligomers was 30%, 59%, and 38% respectively, whereas those of the unheated oil was much higher (95%, 90%, and 91% respectively). True digestibility did not change for the triacylglycerol monomers. The plasma concentration of triacylglycerol tended to decrease (9.7%; p > 0.05) in the rats receiving the heated oil, suggesting some delay in the absorption mechanism. Data show that thermoxidized compounds from abused oil are poorly but actively hydrolysed and absorbed in vivo. Copyright © 2003 Society of Chemical Industry
Fatty acid composition and sensory quality of Musculus longissimus and carcass parameters in red deer (Cervus elaphus) grazed on natural pasture or fed a commercial feed mixture
Authors: Wiklund Eva , Manley Timothy R , Littlejohn Roger P , Stevenson‐Barry Joanne M
Published: March 2003

The effects of feeding regimen on carcass characteristics, fatty acid composition and sensory quality of Musculus longissimus were studied in 16 male red deer. All animals were farm raised; eight were grazed on pasture and eight were fed a pelleted commercial feed mixture for 10 weeks prior to slaughter. The pellet‐fed deer had a significantly higher dressing percentage than the pasture group. No differences were found in ultimate pH values and muscle glycogen content when comparing the treatment groups. Polar and neutral lipid fatty acid composition of the meat were analysed separately. Meat from pasture‐fed deer showed a high content of the fatty acid 18 : 3 n‐3 in the polar lipid fraction. In the same lipid fraction, the fatty acid 18 : 2 n‐6 was dominant in meat from the pellet fed animals. Similar differences in the neutral lipid fraction were found when comparing fatty acid composition between treatment groups; however, the abundance of these fatty acids was much less. A trained expert panel using a descriptive test assessed the sensory profile of the meat. There was a significant difference between the two treatment groups for the sensory attribute of grassy flavour, with the pellet‐fed animals having less grassy flavour than the animals grazing pasture. It was concluded that further research is needed to explore the effects of various feeding regimens applied to deer on parameters associated with meat lipids, including antioxidants and oxidation products. Copyright © 2003 Society of Chemical Industry
Microbial degradation of rice and barley straws in the sheep rumen and the donkey caecum
Authors: Agbagla‐Dohnani Ahoefa , Cornu Agnès , Nozière Pierre , Besle Jean‐Michel , Dulphy Jean‐Pierre , Doreau Michel , Grenet Elisabeth
Published: March 2003

The chemical composition, intake, digestibility, ultrastructure and microbial degradation of rice straw from Camargue were compared with barley straw. These variables were observed in two different herbivore digestive ecosystems: the sheep rumen and the donkey caecum. The two straws differed essentially in their ash content, which was three times higher in rice, owing to its silica content. Other chemical components were comparable, except a higher phenolic acids‐to‐lignin ratio in rice. Rice straw was better ingested than barley straw. Organic matter and neutral detergent fibre digestibilities were the same in both straws. Dry matter and cell wall disappearances could be adjusted to the exponential modelling equation with lag time, and differed between animals but not between straws. The sheep rumen had a higher extent of degradation, but the donkey caecum had a higher degradation rate. Statistical analysis revealed that cell‐wall components degradation was similar in the two straws except for ferulic acid, which was more degraded in rice straw. Scanning electron microscopy showed important differences in parenchyma degradation, which was much more effective in rice. Copyright © 2003 Society of Chemical Industry
Impact of mass transport on microstructure of Granny Smith apple parenchyma during osmotic dehydration
Authors: Quiles Amparo , Pérez‐Munuera Isabel , Hernando Isabel , Lluch Ma Ángeles
Published: March 2003

The chemical components of foods are organized in microscopic structures that can modify mass transfer. The study of material penetration in foods can be made using X‐ray microanalysis. In order to study the microstructural behaviour when fruit was osmotically dehydrated, a glucose molecule modified with chloral (1,2‐O‐2′,2′,2′‐trichloroethylidene‐α‐D‐glucofuranose) was used as an osmotic standard with chlorine detectable by energy‐dispersive X‐ray analysis. Parenchyma of Granny Smith apple is a simple tissue, so it was chosen as reference. The results show that both the apoplastic and symplastic routes played an active role in mass transfer. The osmotic agent penetrated both the symplast and apoplast well into the depths of the fruit, although greater deterioration of cells was observed near the surface. Copyright © 2003 Society of Chemical Industry
Immobilization of invertase on celite and on polyacrylamide by an absorption procedure
Authors: Mansour Esam H , Dawoud Fathy M
Published: March 2003

Invertase from Saccharomyces cerevisiae was immobilized on celite and on polyacrylamide by an absorption procedure. The properties of the immobilized invertase were characterized and compared with those of soluble invertase. The activity yield for immobilized invertase on celite and on polyacrylamide was 92% and 81% respectively. The optimum pH and temperature for both soluble and immobilized invertase activity were 4.6 and 60 °C respectively. The activity of immobilized invertase is stable in the range pH 4.0–6.5. The immobilized invertase was thermostable when incubated at temperatures ranging from 40 to 60 °C. Immobilized invertase had a high stability when stored at room temperature for 90 days and had an excellent operational stability when used 20 times repeatedly. The invertase immobilized on celite was more stable than invertase immobilized on polyacrylamide. The invertase preparations immobilised by absorption procedures exhibited marked stability towards temperature, pH changes and had high storage and operational stability, suggesting their excellent potential for use as supports. Copyright © 2003 Society of Chemical Industry
Quality characteristics of refined, bleached and deodorized palm olein and banana chips after deep‐fat frying
Authors: Che Man Yaakob B , Ammawath Wanna , Rahman Russly A , Yusof Salmah
Published: March 2003

The changes in quality characteristics of refined, bleached and deodorized (RBD) palm olein used for deep‐fat frying of banana chips (180°C for 3 min at 17 min intervals for 2 h day−1, to give six fryings per day and 30 fryings over five consecutive days) were studied. Four frying systems were used: RBD palm olein without antioxidant (system 1); RBD palm olein with 0.2 g kg−1 α‐tocopherol (system 2); RBD palm olein with 1 g kg−1 oleoresin rosemary (system 3); and RBD palm olein with the combination of 0.1 g kg−1 α‐tocopherol + 0.5 g kg−1 oleoresin rosemary (system 4). Fried oil samples were analysed for fatty acid composition, peroxide value (PV), anisidine value (AnV), totox value, free fatty acids (FFA) value, iodine value, $E_{\rm 1cm}^{1\%}$ at 232 and 268 nm, colour and viscosity. The crispness and sensory evaluation of the banana chips fried in this study were also evaluated. The results showed that RBD palm olein with added antioxidant reduced PV, AnV, totox value, $E_{\rm 1cm}^{1\%}$ at 232 and 268 nm, FFA and viscosity. The order of effectiveness in inhibiting oil oxidation in RBD palm olein was: oleoresin rosemary > α tocopherol + oleoresin rosemary > α‐tocopherol > control. For the crispness, the force values of banana chips fried in all systems were comparable. Sensory evaluation of fried banana chips for each system showed that there was no significant (P > 0.05) difference in terms of colour, flavour, odour, texture and overall acceptability. Copyright © 2003 Society of Chemical Industry
Effects of variety on chemical composition, in situ nutrient disappearance and in vitro gas production of spineless cacti
Authors: Batista Angela M , Mustafa Arif F , McAllister Tim , Wang Yuxi , Soita Henry , McKinnon John J
Published: March 2003

This study determined the chemical composition, in situ ruminal nutrient disappearance and in vitro gas production kinetics of three cactus varieties grown in northeastern Brazil. The varieties were Gigante, IPA‐20 and Miúda. Results of the chemical analysis showed no significant differences in ash, ether extract, crude protein (CP) and neutral detergent fibre (NDF) between the cactus varieties. However, acid detergent fibre was highest (P < 0.05) for IPA‐20, intermediate (P < 0.05) for Gigante, and lowest (P < 0.05) for Miúda. Fractionation of carbohydrate and true protein based on rates of ruminal degradation indicated that the main carbohydrate component was the rapidly degradable fraction, whereas the main true protein component was the intermediately degradable fraction. No differences in carbohydrate or protein fractions were observed between the cactus varieties. Results of the in situ experiment showed no differences in ruminal dry matter (DM, average 803 g kg−1 of DM), CP (900 g kg−1 of CP) and NDF (611 g kg−1 of NDF) disappearance between the three cactus varieties after 48 h of ruminal incubation. Potential gas production at the end of 48 h of incubation was higher (P < 0.05) for Gigante than for the Miúda or IPA‐20 variety. However, rate of gas production and lag time in gas production were similar for the three cactus varieties at 6.8% h−1 and 0.6 h respectively. Our results showed little or no differences in chemical composition or ruminal nutrient degradabilities between the three cactus varieties. Copyright © 2003 Society of Chemical Industry
Evaluating quality of yellow alkaline noodles made from mechanically abraded sprouted wheat
Authors: Chakraborty Monisha , Hareland Gary A , Manthey Frank A , Berglund Lois R
Published: March 2003

Five hard red spring wheat genotypes, with initial falling numbers (FNs) ranging from 62 to 427 s, were mechanically abraded for 30, 60, and 120 s to reduce sequentially α‐amylase activity in the grain. Mechanical abrasion prior to milling significantly increased FN and reduced amylase activity in pre‐harvest sprouted wheat. The abraded grains were milled and the resultant flour samples were evaluated for starch gelatinization properties and yellow alkaline noodle (YAN) quality. Mechanical abrasion on sprouted kernels resulted in significant improvements in starch pasting properties accompanied by marginal decreases in flour ash and protein contents. Initial noodle brightness L* improved in most samples with mechanical abrasion. However, L* values dropped significantly during storage, with the greatest decline seen in the highly sprouted sample. Noodle cooking and textural qualities were relatively unaffected by sprout damage or mechanical abrasion, possibly due to amylase inhibition by the carbonate salts present in the formula. Mechanical abrasion prior to milling was found to reduce amylase activity significantly in moderately sprouted wheat. YAN, however, showed high tolerance to sprout damage, and produced noodles of acceptable texture without mechanical abrasion. Copyright © 2003 Society of Chemical Industry
Effect of year‐to‐year variation and genotype on trypsin inhibitor level in common bean (Phaseolus vulgaris L) seeds
Authors: Piergiovanni Angela R , Pignone Domenico
Published: March 2003

Changes in trypsin inhibitor (TI) level in common bean (Phaseolus vulgaris L) seeds were investigated in relation to protein content, year‐to‐year variation and genotype. Twenty‐one local populations from the Basilicata region (southern Italy) were tested over 3 years (1995–97). The populations were cultivated in the same environment in which they were traditionally cultivated and are currently grown. A wide variation of TI content, expressed as units of inhibitor per milligram of dry matter (TIU mg−1 DM), was found within the populations of the collection (x̄ ± 2σ: 27.67 ± 2.72 in 1995, 25.31 ± 2.82 in 1996, and 23.39 ± 2.14 in 1997). It was found that 16 populations showed a decrease of TI levels from 1995 to 1997; one population showed the opposite trend, in two populations the TI level remained unchanged, and in another two it reached its maximum in the intermediate year. A t‐test showed that only the 1995–97 variation is highly significant (p < 0.02). The increase of TI expression might possibly be related to the drought stress suffered by plants during the vegetative growth stage: rainfall received in 1995 during the growing season was lower (171 mm) than in 1996 (477 mm) and 1997 (388 mm); however, other abiotic or biotic factors cannot be excluded. It is suggested that the extent of TI variation contains a genetic component. Copyright © 2003 Society of Chemical Industry
The influence of selenium on the antioxidant activity of green tea
Authors: Xu Juan , Zhu Shigui , Yang Fangmei , Cheng Licheng , Hu Yun , Pan Genxing , Hu Qiuhui
Published: March 2003

This study was aimed at determining the effects of selenium on the contents of vitamin C, amino acid, total water‐soluble solids and tea polyphenol, and whether the antioxidant activity of selenium‐enriched green tea is enhanced compared with regular green tea by linoleic acid oxidation and the lard oxidation method. The contents of selenium, vitamin C and tea polyphenol in green teas were greatly increased by foliar application of selenium‐enriched fertilizer. No significant differences of the contents of vitamin C, amino acid and tea polyphenol were observed between green tea treated with sodium selenite and that without selenium. The selenium‐enriched green tea exhibited significantly higher antioxidant activity than regular green tea, both in linoleic acid oxidation and in the lard oxidation system. These results suggest that the antioxidant activity of green tea is significantly enhanced by the combination of selenium and green tea constituents compared with that of regular green tea. Copyright © 2003 Society of Chemical Industry
Leguminous trees for the restoration of degraded sodic wasteland in eastern Uttar Pradesh, India
Authors: Mishra A. , Sharma S. D.
Published: March 2003

The study was carried out in sodic lands of Sultanpur District, Uttar Pradesh, India. The barren soils and the soils supporting 3‐, 6‐ and 9‐year‐old plantations of Prosopis juliflora (Swartz) D.C. and Dalbergia sissoo Roxb. Ex. D.C. plantations were examined to assess the rate and extent of changes undergone by physical and chemical properties of the soil. The study brought out that these species indicated the process of soil rehabilitation from the early stages of growth and the extent of rehabilitation increased with the age of the plantation. P. juliflora was found to be more efficient in reclaiming the soil in comparison to D. sissoo. The decline in soil pH and exchangeable sodium percentage (ESP) indicates the desodification and enrichment with organic C, N, P and K indicates improvement in nutrient status of the soil. After 9 years of planting the surface soil was completely desodified as indicated by pH (<8ċ5), ESP (<15) and sodium adsorption ration (<15). A significant increase in organic C, exchangeable Ca2+ and Mg2+ and decrease in exchangeable Na+ reveals that the nutrient status is attaining suitable balance. The physical attributes of the soil also underwent improvement in terms of increase in porosity, water‐holding capacity, field capacity and decline in bulk density. The flocculation of dispersed soil surface and improvement in soil structure was indicated by increased infiltration rate (cm h−1) and soil permeability (cm2). Copyright © 2003 John Wiley & Sons, Ltd.
Rangeland development of the Mu Us Sandy Land in semiarid China: an analysis using Landsat and NOAA remote sensing data
Authors: Runnström M. C.
Published: March 2003

Degradation of the dry semiarid ecosystems in the Mu Us Sandy Land of north central China was explored using high‐resolution satellite images from 1978, 1987 and 1996. This study monitored both changes in grassland biomass production and reclamation activities to detect the nature and scale of land degradation since major economic reforms were introduced in 1978. The position of the high‐resolution images within the vegetation cycles was inspected from National Oceanographic and Atmospheric Administration (NOAA) NDVI images at 10‐day repetition and seasonal precipitation patterns. A model was developed to categorize changes in the vegetation signal activity from 30 × 30 m pixels into vegetation cover development and land‐use changes between 1987 and 1996. A general increase of biomass production was evident despite the rapid increase in numbers of grazing animals. This increase in biomass was confirmed by the NOAA time series, which also revealed annual variability related to the amount and pattern of the seasonal rains. Rangeland conversion to farmland was detected, and this process has increased the area of cultivation almost fivefold. The classified area of cultivation corresponds with reported statistical records, also showing that irrigation features in virtually 100 per cent of the sown area. Signs of declining biological production, indicating land degradation processes, are few. Biomass production has increased, with a gain in the economic output from both crop and animal production. The early start of active measures to halt desertification has increased vegetation cover and lowered wind erosion potential and grasslands seems to be managing the high levels of grazing pressure. Copyright © 2003 John Wiley & Sons, Ltd.
Potentials and constraints of the farmer‐to‐farmer programme for environmental protection in Nicaragua
Authors: Hawkesworth S. , García Pérez J. D.
Published: March 2003

The natural environment in Nicaragua has been damaged by rural development policies geared for the export of cash crops, by uneven land distribution and the near absence of concerns about the environmental effects of the prevailing model of development. The demands made by market forces for the export of primary materials have been reasons for land degradation in the big farms, and the need to survive a poverty stricken existence has forced the peasantry to damage the marginal and fragile land they worked. Successive governments did not address these underlying causes of environmental degradation, and even the opportunities afforded by the environment programme that resulted from the 1979 Sandinista revolution, did not result in significant environmental improvements. The paper briefly considers the constraints faced by the Sandinista administration and how the farmer‐to‐farmer programme (Campesino‐a‐Campesino) was brought about as a result of the impacts of the Sandinista era. The substantive part of the paper considers PCAC's significance as an agroecological programme and its advantages and limitations for improving peasants' livelihoods via dissemination of land‐protective measures. The viability of the programme is assessed by field work carried out examining in detail the case of three communities, and the paper concludes that the gains made in environmental protection and conservation are in jeopardy without structural policy changes. The paper proposes that for the programme to improve its potential, adequate political will, power and organization are necessary to facilitate greater access to secure land tenure among the peasantry. Copyright © 2003 John Wiley & Sons, Ltd.
Trends in relief design and construction in opencast mining reclamation
Authors: Nicolau J.‐M.
Published: March 2003

This paper examines trends in topography design and construction in opencast mining restoration. The greatest geomorphological focus is the protection of aquatic ecosystems downstream of reclaimed sites through the construction of topographies and structures that not only reduce sediments and contaminants to a minimum, but which soften the impact of maximum water flows. From the ecological point of view, the most important focus is the integration of the geomorphological component with those of the soil and vegetation, and the formation of a functional ecosystem with the capacity to maintain itself. The conceptual models of relief that have been used in practice are discussed and criticized: these include the platform‐bank model (geotechnically but not ecologically stable), faithful reproduction of the original topography (inadequate in steep areas), and understanding the hydrological basin as a restoration unit (now considered the most appropriate). Finally, erosion models are reviewed as tools for relief design. The practicality of ‘RUSLE 1.06 for Mined Lands, Construction Sites and Reclaimed Lands’ is underlined owing to its ease of use. Copyright © 2003 John Wiley & Sons, Ltd.
Tackling degradation of a seminatural landscape: options and evaluations
Authors: Boothby J.
Published: March 2003

Degradation of a seminatural pond landscape in North West England has been occurring for at least 150 years. The remaining resource of 35 000 ponds is being reduced by natural succession, but is also being anthropogenically modified, by land development, neglect and from poorly considered management regimes. This paper defines degradation for the individual pond and for the pond landscape. Implications of degradation are drawn. Four existing approaches developed to combat degradation (including legal strictures, planning rules and voluntary conservation schemes) are evaluated with reference to both ecological and socio‐economic principles. Finally, a new planning philosophy and structure in the United Kingdom is assessed for its ability to combat degradation; particular emphasis is placed upon an ecological networks approach which offers new hope for conservation of both pond habitats and for their distinctive fauna and flora. Copyright © 2003 John Wiley & Sons, Ltd.
Oxidation behaviour of a PVD processed Mg‐14Ti alloy
Authors: Pérez P. , Garcés G. , Adeva P.
Published: March 2003

The oxidation behaviour in air of a physical vapour deposited (PVD) Mg‐14Ti (wt. %) alloy was studied in the 325–450°C temperature range. The 2–3 mm thick deposit was grown in two stages. The first half of the deposit was mechanically worked during the process and then, deposition went on without this flailing period. The microstructure of the deposit can be divided into two parts, each one involving half of the total thickness. The oxidation resistance is strongly affected by the microstructure of the deposit, flailed or unflailed. Unflailed part of the deposit presents open boundaries with a high density of defects. Internal oxidation can proceed through this kind of boundaries. This is the reason of anomalous behaviour during the initial stages of oxidation, with maximum mass gain at 350°C. The flailed part shows a few cracks but the grain boundaries are practically free of defects. Flaws and cracks act as the starting point for the development of large intrusions, which contribute substantially to the total mass gain of the alloy, especially with increasing the temperature.
Dental amalgam – the effect of the technology of alloy powder preparation on the corrosion behaviour and the release of mercury
Authors: Joska L. , Bystrianský J. , Novák P.
Published: March 2003

Dental amalgams are based on a broad spectrum of materials differing in their chemical composition, metallurgical treatment, and in the way the initial alloys powders are prepared. In addition to their chemical composition, amalgams based on various powders differ in both their microstructure and the amount of mercury needed for preparation. All these facts may affect electrochemical processes occurring during their interaction with oral fluids, and also mercury release. While verifying the effect of the technology used for the preparation of the high‐copper ternary alloy powder on the properties of resulting amalgams, this study aimed at the mechanism of their interaction with a model saliva solution as well as mercury release was included. Measurements were done in a model saliva solution using standard electrochemical methods and exposition measurements. The interaction of individual types of amalgams with artificial saliva did not reveal any significant differences. The free corrosion potential of all these amalgams in an aerated solution settled in the range of values in which tin oxidation, resulting in a layer of insoluble corrosion producsts, turned out to be the dominant anodic process. The rate of mercury release was the lowest for amalgams based on a gas‐atomized alloy. The highest rate of mercury release, and also its dependence on time, was exhibited by lathe‐cut powder based amalgam. In addition to different volume fraction of the Ag‐Hg phase and the level of its tin alloying, this different behaviour may be explained by differences in the rate at which a layer of tin corrosion products acting as a barrier to mercury release is formed.
Anion effects on the stress corrosion cracking behaviour of aluminium alloys
Authors: Braun R.
Published: March 2003

The stress corrosion cracking behaviour of plate material of the aluminium alloys 2024‐T351, 8090‐T8171, 7475‐T651, and 7075‐T7351 was investigated performing constant load tests. Short transverse tensile specimens were permanently immersed in aerated aqueous 0.6 M Na2Cl solutions with additions of Na2SO4, NaNO3, NaHCO3, NH4HCO3, Na2HPO4, Na2SO3 or Na2CO3. The concentration of the added salts was 0.06 M. The applied stress was 100 MPa, except with 7075‐T7351 specimens, which were loaded at 300 MPa. Environment induced failure was not observed in neutral 0.6 M NaCl solution. The various salts added promoted intergranular stress corrosion cracking with the alloys 2024‐T351, 8090‐T8171, and 7475‐T651. Threshold stresses were generally below 100 MPa. For 8090‐T8171 exposed to chloride containing electrolytes with additions of sulfate, hydrogen phosphate, or sulfite, threshold stresses were approximately 100 MPa or higher. Similar results were obtained for 7475‐T651 plate when immersed in chloride‐hydrogen phosphate and chloride‐carbonate solutions. Alloy 7075‐T7351 was resistant against intergranular stress corrosion cracking. Specimens suffered pitting corrosion during immersion in the corrosive environments. Failure observed with 7075‐T7351, in particular when exposed to the chloride‐nitrate solution, was associated with reduction of cross‐sectional area due to pitting and transgranular stress corrosion cracking.
Untersuchungen zum Einfluss des Stickstoffs auf das Lochkorrosionsverhalten hochlegierter austenitischer Cr‐Ni‐Mo‐Stähle
Authors: Eckstein Ch. , Spies H.‐J. , Zimdars H.
Published: March 2003

Austenitische Stähle mit 18% Chrom und 12% Nickel sowie abgestuften Molybdängehalten von 0.5 bis 3.6% wurden einer Aufstickung in der Gasphase unterzogen. Durch einen gezielten Abtrag der behandelten Proben konnten Korrosionsuntersuchungen an Oberflächen mit Stickstoffgehalten bis 0,45% durchgeführt werden. Als Bewertungskriterien für die Beständigkeit gegen Lochkorrosion wurden das chronopotentiostatisch bei 25°C in 0,5 M NaCl ermittelte Lochkorrosionspotential ULstat und die in künstlichem Meerwasser [DIN 81249‐4] bestimmte Lochkorrosionstemperatur (critical pitting temperature CPT) verwendet. Es zeigte sich, dass der Einfluss des Stickstoffs auf beide Größen sehr gut durch den Faktor 25 in der Wirksumme PRE = Cr + 3.3 · Mo + 25 · N beschrieben werden kann. Eine unterschiedliche Wirksamkeit des Stickstoffs in Abhängigkeit vom Molybdängehalt der Grundlegierung war im verwendeten Zusammensetzungsbereich und den eingesetzten Korrosionssystemen nicht zu erkennen.
Corrosion‐erosion damage of heat exchanger tubes by desalted crude oil flowing at shell side
Authors: Klenowicz Z. , Darowicki K. , Krakowiak S. , Krakowiak A.
Published: March 2003

Heat exchanger tubes were locally heavily damaged by desalted crude forming a shell side stream under the pressure of 2.6 MPa and at the temperature of 385–395 K. Boiler steel tube temperature was 97 K higher compared to that of the crude oil at its inlet to the exchanger. Two types of segmental baffles effected cross vortex type flow that was lowered nearly to a standstill at locations where the highest damage occurred. Close to the baffles where the damage was the highest the flow was completely different from that of the window flow. These were found from analyses of the flow and of locations of perforations. Most of the tube surface was with no damage and was covered with protective organic‐inorganic deposit. Electrochemical investigation proved a cathodic character of the deposited film against bare steel. Metallography examination of the steel showed typical structures that could not affect much the damage. The crude with low water content was not found aggressive when a corrosion test was performed at elevated temperature. The tests excluded the possibility for high rate of electrochemical corrosion at the surfaces with removed protective layers. The only reason of the damage may be cavitation corrosion at the ways of crude slow vortex flow at which temperature was high enough to allow explosions of low volatile components [1].
Predicting the Molecular Arrangements in Polymer‐Based Nanocomposites
Authors: Vacatello Michele
Published: March 2003

Monte Carlo computer simulations have been performed for model polymers containing randomly distributed spherical filler particles (20% in volume) with diameter between 4 times and 28 times the transverse diameter of the chains. By analyzing the results in conjunction with those of previous simulations, a few simple rules are deduced allowing to predict approximately the molecular arrangements in these complex systems.

Schematic two‐dimensional picture of the mutual arrangements of filler particles and chains predicted for system M12.

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Schematic two‐dimensional picture of the mutual arrangements of filler particles and chains predicted for system M12.
Application of the Christensen‐Lo Model to the Reinforcement of Elastomers by Fractal Fillers
Authors: Raos Guido
Published: March 2003

This paper is concerned with the development of a hydrodynamic model for the reinforcement of rubber by colloidal fillers such as silica and carbon black. Each fractal aggregate is replaced by an equivalent effective sphere, and the reinforcing ability of the latter is estimated using the Christensen‐Lo solution of the “three‐phase composite sphere model”. With a single adjustable parameter, the model allows a quantitative interpretation of the small‐strain modulus of rubber loaded with up to 50 PHR of N234 carbon black, which falls just below the filler overlap concentration. No additional contributions to the small‐strain modulus by filler–filler “interactions” are needed to interpret the data.

A branched filler aggregate made up of spherical primary particles (black) and the effective sphere replacing it (gray).

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A branched filler aggregate made up of spherical primary particles (black) and the effective sphere replacing it (gray).
Size‐Dependent Melting Temperature of Polymers
Authors: Jiang Qing , Yang Chun Cheng , Li Jian Chen
Published: March 2003

A general model for all kinds of size‐dependent melting points, free of any adjustable parameter, is extended to illustrate the size‐dependence of the melting temperature of polyethylene (PE). The model prediction for the depression of the melting temperature of PE is consistent with the calorimetric experimental results as shown in the Figure where the melting temperature of lamellae PE crystals as a function of the thickness of the crystals is presented.

The Tm(D) function of PE shown as a solid line in terms of Equation (4). The necessary parameters for use of Equation (4) are shown in Table 1. The symbols ○ and • denote the experimental evidence of Tm(D) of linear alkanes14b and cyclic alkanes,14c respectively. The values of D are determined by D = 0.1273n6 with 0.1273 nm being the orthorhombic CC lattice distance in the c‐direction.5 The symbol □ denotes the experimental evidence of chain‐extended PE.6

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The Tm(D) function of PE shown as a solid line in terms of Equation (4). The necessary parameters for use of Equation (4) are shown in Table 1. The symbols ○ and • denote the experimental evidence of Tm(D) of linear alkanes14b and cyclic alkanes,14c respectively. The values of D are determined by D = 0.1273n6 with 0.1273 nm being the orthorhombic CC lattice distance in the c‐direction.5 The symbol □ denotes the experimental evidence of chain‐extended PE.6
Model Studies of Nitroxide‐Mediated Styrene Miniemulsion Polymerization – Opportunities for Process Improvement
Authors: Ma John W. , Cunningham Michael F. , McAuley Kim B. , Keoshkerian Barkev , Georges Michael K.
Published: March 2003

Modeling studies were performed to investigate how persulfate‐initiated nitroxide‐mediated styrene miniemulsion polymerizations are influenced by changes to the polymerization recipe. By manipulating the initial concentrations of potassium persulfate and nitroxide, and the aqueous phase volume, trends in the predicted polymerization time, number average molecular weight, polydispersity and degree of polymer livingness were identified that indicate operating conditions for improved process performance. Specifically, our model predicts the existence of experimental conditions that simultaneously minimize polymer polydispersity and maximize the livingness of the polymer. The mechanisms responsible for the predicted trends were identified from the predicted molecular weight distributions of the living and dead polymer chains.

Predicted number MWDs at 20% monomer conversion for styrene NMMP systems employing various levels of [KPS]aq,0. Dormant KPS‐initiated polymer radicals.

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Predicted number MWDs at 20% monomer conversion for styrene NMMP systems employing various levels of [KPS]aq,0. Dormant KPS‐initiated polymer radicals.