Decrease In Total Nitrogen Content Research Articles

Immobilization of fluorenone derived π-acceptors on poly (GMA-co-EGDMA) for the removal of refractory nitrogen species from bitumen derived gas oil

A pretreatment process employing porous polymer support coupled with electron withdrawing π-acceptors has been developed for the selective removal of refractory nitrogen compounds from gas oil via charge transfer complex (CTC) mechanism. Copolymer of glycidyl methacrylate and ethylene glycol dimethacrylate, poly (GMA-co-EGDMA) was used as the porous polymer support for the immobilization of fluorenone based π-acceptors. In order to study the effect of various π-acceptors, 2,7-dinitro-9-fluorenone (DNF); 2,4,7-trinitro-9-fluorenone (TriNF) and 2,4,5,7-tetranitro-9-fluorenone (TENF) were immobilized on poly (GMA-co-EGDMA) via hydroxylamine (ON) linker. BET, CHNOS elemental analysis, SEM and TG/DTA were employed for determining the chemical and physical properties of the synthesized compounds. Characterization by FT-IR revealed the immobilization of π-acceptor on the polymers. Total Nitrogen/Sulfur analyzer affirmed the decrease in total nitrogen and sulfur content of bitumen derived light gas oil (LGO) after pre-treatment with immobilized polymers. This decrease in total nitrogen content of gas oil is a direct consequence of the formation of charge transfer complexes between π-acceptors immobilized polymer and heterocyclic nitrogen species present in gas oil. Furthermore, spectroscopic features of the charge transfer interactions between π-acceptors and basic and non-basic nitrogen species were confirmed by UV–vis spectrophotometer. 13C NMR was used to calculate the decrease in aromatic content after treatment. The optimized polymers were successful in removing up to 14.4% of the total nitrogen content in a single contact using 25wt% of the immobilized polymers with respect to LGO while only 1.4% of the total sulfur moieties were removed at 25°C.

Physico‐chemical and functional properties of proteins from green mussel (Perna viridis) during ice storage

AbstractThe effect of ice storage on the properties of proteins from green mussel (Perna viridis) has been investigated. Ice storage of green mussel for a period of 19 days revealed a marginal increase in moisture and decrease in total nitrogen content. There was significant reduction (P < 0.05) in non‐protein nitrogen content and calcium activated adenosine triphosphatase enzyme activity. The solubility of the total proteins in high ionic strength buffer decreased marginally. The ice storage of green mussel had a significant effect on association‐dissociation/denaturation phenomenon of proteins as revealed by gel filtration profile, reduced viscosity values and sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS‐PAGE) pattern. The dynamic viscoelastic behaviour of green mussel meat in the temperature range of 30–90 °C revealed higher storage modulus (G′) values at a later part of ice storage. The emulsion capacity of green mussel did not show significant variation (P < 0.05) during ice storage. Copyright © 2006 Society of Chemical Industry

Fluid and gas migration in the North German Basin: fluid inclusion and stable isotope constraints

Fluid inclusions have been studied in minerals infilling fissures (quartz, calcite, fluorite, anhydrite) hosted by Carboniferous and Permian strata from wells in the central and eastern part of the North German Basin in order to decipher the fluid and gas migration related to basin tectonics. The microthermometric data and the results of laser Raman spectroscopy reveal compelling evidence for multiple events of fluid migration. The fluid systems evolved from a H2O–NaCl±KCl type during early stage of basin subsidence to a H2O–NaCl–CaCl2 type during further burial. Locally, fluid inclusions are enriched in K, Cs, Li, B, Rb and other cations indicating intensive fluid–rock interaction of the saline brines with Lower Permian volcanic rocks or sediments. Fluid migration through Carboniferous sediments was often accompanied by the migration of gases. Aqueous fluid inclusions in quartz from fissures in Carboniferous sedimentary rocks are commonly associated with co-genetically trapped CH4–CO2 inclusions. P–T conditions estimated, via isochore construction, yield pressure conditions between 620 and 1,650 bar and temperatures between 170 and 300°C during fluid entrapment. The migration of CH4-rich gases within the Carboniferous rocks can be related to the main stage of basin subsidence and stages of basin uplift. A different situation is recorded in fluid inclusions in fissure minerals hosted by Permian sandstones and carbonates: aqueous fluid inclusions in calcite, quartz, fluorite and anhydrite are always H2O–NaCl–CaCl2-rich and show homogenization temperatures between 120 and 180°C. Co-genetically trapped gas inclusions are generally less frequent. When present, they show variable N2–CH4 compositions but contain no CO2. P–T reconstructions indicate low-pressure conditions during fluid entrapment, always below 500 bar. The entrapment of N2–CH4 inclusions seems to be related to phases of tectonic uplift during the Upper Cretaceous. A potential source for nitrogen in the inclusions and reservoirs is Corg-rich Carboniferous shales with high nitrogen content. Intensive interaction of brines with Carboniferous or even older shales is proposed from fluid inclusion data (enrichment in Li, Ba, Pb, Zn, Mg) and sulfur isotopic compositions of abundant anhydrite from fissures. The mainly light δ34S values of the fissure anhydrites suggest that sulfate is either derived through oxidation and re-deposition of biogenic sulfur or through mixing of SO 2−4 -rich formation waters with variable amounts of dissolved biogenic sulfide. An igneous source for nitrogen seems to be unlikely since these rocks have low total nitrogen content and, furthermore, even extremely altered volcanic rocks from the study area do not show a decrease in total nitrogen content.

Degradation of mangrove leaf litter in the St Lucia Estuary as influenced by season and exposure

Rates of degradation of leaves of Avicennia marina (Forssk.) Vierh. and Bruguiera gymnorrhiza (L.) Lam. were investigated in St Lucia Estuary in the warm and cool seasons at three positions on the shore, viz. where leaves were constantly submerged, where they were exposed only at low spring tides and where they were inundated only at high spring tides. Degradation occurred more rapidly in A. marina than in B. gymnorrhiza and leaves constantly submerged decomposed at a faster rate than those exposed for most of the time. Decomposition rates were consistently lower in the cool season. The concentration of nitrogen in all leaves increased over the decomposition period, although there was a decrease in total nitrogen content with rapid decomposition. While under certain conditions degradation proceeds at a rapid rate, because of the lower additions of nitrogen to the system from decomposing leaves, there do not appear to be significant ecological advantages from this rapid decomposition. There were sharp decreases in the phosphorus and potassium contents of the leaves, presumably largely due to leaching. This work has emphasized the importance of mangrove leaf litter as a source of, and substrate for, nutrient release. Die afbraaktempo van blare van Avicennia marina (Forssk.) Vierh. en Bruguiera gymnorrhiza (L.) Lam. is gedurende die warm en koel seisoene op drie verskillende plekke op die kus van die St Luciariviermond ondersoek, naamlik waar die blare deurlopend ondergedompel is, waar dit slegs gedurende lae springgety ontbloot is en waar dit slegs gedurende hoë springgety bedek word. Afbraak het vinniger plaasgevind by A. marina as in B. gymnorrhiza en blare wat deurlopend ondergedompel is het teen 'n vinniger tempo vergaan as dié wat vir die grootste deel van die tyd ontbloot was. Afbraaktempo's was deurgaans laer gedurende die koelseisoen. Die stikstofkonsentrasie in al die blare het gedurende die afbraakperiode toegeneem alhoewel daar tydens snelle afbraak 'n afname in totale stikstofinhoud was. Alhoewel daar onder sekere toestande afbraak teen 'n versnelde tempo plaasvind, wil dit voorkom asof daar, vanweë die stadiger toevoeging van stikstof tot die sisteem van die verrottende blare, nie 'n merkbare ekologiese voordeel van die vinnige afbraak is nie. Daar was skerp afnames in die fosfaat- en kaliuminhoud van die blare, vermoedelik hoofsaaklik vanweë uitloging. Hierdie werk het die belangrikheid van manglietblaarval as 'n bron van, en substraat vir vrystelling van voedingstowwe beklemtoon.

Studies on permeability changes in cotton (Gossypium hirsutum) caused byVerticillium albo-atrum

The present work demonstrates permeability changes inVerticillium-infected cotton tissues. Permeability was determined by measuring the exosmosis rate of electrolytes. The roots and leaves showed more electrolytic leakage as compared to the stem. This leakage while continues in the leaf tissue, a fall was recorded later for the roots. The stem tissues were affected least. The ash analysis of the diseased leaves showed a marked decrease in the potassium and sodium ions as compared to the healthy tissues. Calcium showed increased accumulation in diseased tissues. There was a decrease in total nitrogen content of diseased leaves while the infected root and stem tissues did not show much difference from the healthy tissues. The total carbohydrate content of the diseased leaves was considerably low but the roots showed an increase over the healthy tissues.

RNA AND PROTEIN METABOLISM IN SENESCENT SHOOT APICES OF ‘ALASKA’ PEAS

Senescence of shoot apices of Pisum sativum L. ‘Alaska’ as measured by cessation of stem elongation was delayed by removal of flowers. Analyses of total RNA, nitrogen, protein and inorganic phosphorus in shoot tips of deflowered and control (flower‐ and fruit‐bearing) plants throughout ontogeny revealed that the levels of all these metabolites declined during senescence. Also throughout ontogeny shoot tips of control and deflowered plants were compared with respect to their ability to enzymically degrade RNA and to take up and incorporate P32‐orthophosphate into RNA. The specific activity of ribonuclease increased as senescence progressed while the absolute activity appeared to decrease in correlation with a decrease in total nitrogen content. Compared with nonsenescing shoot tips, senescing shoot tips accumulated less P32 but exhibited an apparent enhancement of P32 incorporation into RNA, which was attributed to a reduction in the endogenous phosphorus pool causing a smaller dilution of the accumulated P32. It is concluded that decreases in the levels of RNA, protein and inorganic phosphorus and in the tran‐spirational uptake of nutrients are factors correlated with senescence of the shoot apex.

RNA and Protein Metabolism in Senescent Shoot Apices of 'Alaska' Peas

Senescence of shoot apices of Pisum sativum L. ‘Alaska’ as measured by cessation of stem elongation was delayed by removal of flowers. Analyses of total RNA, nitrogen, protein and inorganic phosphorus in shoot tips of deflowered and control (flower- and fruit-bearing) plants throughout ontogeny revealed that the levels of all these metabolites declined during senescence. Also throughout ontogeny shoot tips of control and deflowered plants were compared with respect to their ability to enzymically degrade RNA and to take up and incorporate P32-orthophosphate into RNA. The specific activity of ribonuclease increased as senescence progressed while the absolute activity appeared to decrease in correlation with a decrease in total nitrogen content. Compared with nonsenescing shoot tips, senescing shoot tips accumulated less P32 but exhibited an apparent enhancement of P32 incorporation into RNA, which was attributed to a reduction in the endogenous phosphorus pool causing a smaller dilution of the accumulated P32. It is concluded that decreases in the levels of RNA, protein and inorganic phosphorus and in the tran-spirational uptake of nutrients are factors correlated with senescence of the shoot apex.

Effects of growth inhibitors on response of rat's uterus to estrogen.

SummaryAminopterin, beryllium, cadmium, and strychnine proved effective in reducing the physiological activity of estradiol. All compounds except strychnine effected a decrease in total nitrogen content in the uteri of ovariectomized rats receiving estradiol. Such inhibition was associated with a decrease of water in the uterine tissue and the absence of fat and glycogen. Thus, the inhibitory process is associated with these physiological changes.