var niger endospores: Topics by WorldWideScience.org

Inelastic electron--dipole-molecule scattering at sub-milli-electron-volt energies: HF and NH_3

Niger is the second poorest country in the world but it has natural resources underground in the form of uranium ores deposits. This uranium is currently mined by two companies incorporated under Nigerian law: Somair and Cominak, operated by the principal shareholder Areva (through its subsidiary Cogema). After a presentation of Somair and Cominak key figures, this document details the working conditions and radiological protection, the environmentally friendly operations, the production traceability, the local economic development, the strengthening of the health care system and the development of the infrastructure. (A.L.B.)

2005-02-01

Indoleacetic Acid and Abscisic Acid Antagonism

Studies of destruction of very-high-n (100var-epsilon) for rotationally inelastic scattering of electrons by a polar target varies approximately as 1/var-epsilon, where var-epsilon is the electron energy.

A study of the effects of MeV alpha particles in PE and PVDC

The effects of low concentrations (10 nm or less) of indoleacetic acid and abscisic acid on the phytochrome-mediated attachment of barley root (Hordeum vulgare L., var. Compana)...Full Text Available

1973-01-01

Application of power system stabilizers and static VAR compensators on a longitudinal power system

We have mapped and studied the effects of MeV alpha-particle bombardment in polyvinylidene chloride (PVDC) and polyethylene (PE). We used 3.5 and 5.0 MeV alpha-particle incident beams and stacked polymer films to separate the contributing effects of the electronic ({var_epsilon}{sub e}) and nuclear ({var_epsilon}{sub n}) stopping powers. The electrical conductance and change in the chemical structures were measured by direct resistivity measurement, Raman microprobe, RBS and FTIR. The results indicate significant differences in the ({var_epsilon}{sub e}) and ({var_epsilon}{sub n}) effects at higher alpha-particle bombardment fluences. {copyright} {ital 1997 American Institute of Physics.}

1997-02-01

Biosorption of Cd(II), Ni(II) and Pb(II) from aqueous solution by dried biomass of aspergillus niger: application of response surface methodology to the optimization of process parameters

Dynamic stability improvement of a longitudinal power system using a power system stabilizer (PSS) and a static VAR compensator (SVC) is reported in this paper. An analytical approach is developed for the determination of PSS parameters. Results from time domain simulations indicate that the PSS and the SVC are very effective in damping system oscillations.

1988-11-01

Inelastic electron--dipole-molecule scattering at sub-milli-electron-volt energies: CH_3I and CH_2Br_2

In this study, the biosorption of Cd(II), Ni(II) and Pb(II) on Aspergillus niger in a batch system was investigated, and optimal condition determined by means of central composite design (CCD) under response surface methodology (RSM). Biomass inactivated by heat and pretreated by alkali solution was used in the determination of optimal conditions. The effect of initial solution pH, biomass dose and initial ion concentration on the removal efficiency of metal ions by A. niger was optimized using a design of experiment (DOE) method. Experimental results indicated that the optimal conditions for biosorption were 5.22 g/L, 89.93 mg/L and 6.01 for biomass dose, initial ion concentration and solution pH, respectively. Enhancement of metal biosorption capacity of the dried biomass by pretreatment with sodium hydroxide was observed. Maximal removal efficiencies for Cd(II), Ni(III) and Pb(II) ions of 98, 80 and 99% were achieved, respectively. The ...

2009-10-15

Complexation of nitrogen and sulphur donor Schiff's base ligand to Cr(III) and Ni(II) metal ions: Synthesis, spectroscopic and antipathogenic studies

Studies of Rydberg-atom destruction in collisions with the polar targets CH_3I and CH_2Br_2 for values of principal quantum number n in the range 100--400 are reported. Analysis of the data using the essentially-free-electron model suggests that, for ultralow electron energies (#approx#80 #mu#eV to 1 meV), the cross section #sigma#(var-epsilon) for rotationally inelastic scattering of electrons by a polar target varies approximately as 1/var-epsilon, where var-epsilon is the electron energy. The Born approximation does not predict such behavior at very low collision energies, and possible reasons for this discrepancy are discussed.

British Library Electronic Table of Contents (United Kingdom)

2,6-Diacetyl pyridine based ligand was synthesized by the reaction of 2,6-diacetyl pyridine with thiocarbohydrazide in presence of acetic acid. The coordination compounds with Cr(III) and Ni(II) metal ions having [Cr(L)X]X2 and [Ni(L)X]X compositions (where L=ligand and X=NO3^-, Cl^- and CH3COO^-) were synthesized and characterized by physicochemical and spectral studies. The studies like elemental analyses, molar conductance measurements, magnetic susceptibility measurements, IR, UV-Vis, NMR, mass and EPR reveal that the complexes are octahedral. The compounds were examined against the pathogenic fungal and bacterial strains like Alternaria brassicae, Aspergillus niger, Fusarium oxysporum, Xanthomonas compestris and Pseudomonas aeruginosa. A. niger causes the diseases Apergillosis and Oto...

2011-01-01

var gene transcription and PfEMP1 expression in the rosetting and cytoadhesive Plasmodium falciparum clone FCR3S1.2

Translocation and Distribution of Picloram in Bean Plants Associated with Nastic Movements

BackgroundThe pathogenicity of Plasmodium falciparum is in part due to the ability of the parasitized red blood cell (pRBC) to adhere to intra-vascular host cell...Full Text Available

Some Enzymic Activities in the Germinating Oil Palm (Elaeis guineensis) Seedling 1

Nastic responses in bean plants (Phaseolus vulgaris L. var. Black Valentine) occur rapidly when very low concentrations of picloram (4-amino-3,5,6-trichloropicolinic acid) are applied...Full Text Available

1969-10-01

Role of Calcium in Serine Transport into Tobacco Cells

In germinating oil palm (Elaeis guineensis var D × P) seedling, an active lipase was present in the shoot but absent from both the kernel and the haustorium. It has an optimum...Full Text Available

1983-12-01

Rapid Phytochrome-mediated Changes in Adenosine 5?-Triphosphate Content of Etiolated Bean Buds ¹

The transport of serine into tobacco (Nicotiana tabacum L. var. Xanthi) cells grown in liquid medium was studied. Serine transport was maximal below pH 4.0. A time-dependent stimulation...Full Text Available

1978-12-01

Purification and properties of adenylyl sulphate:ammonia adenylyltransferase from Chlorella catalysing the formation of adenosine 5?-phosphoramidate from adenosine 5?-phosphosulphate and ammonia

This study was designed to determine the effects of red and far red irradiation on ATP metabolism in etiolated bean buds (Phaseolus vulgaris L. var. Red Kidney). Compared to dark controls,...Full Text Available

1974-01-01

Malate Oxidation and Cyanide-Insensitive Respiration in Avocado Mitochondria during the Climacteric Cycle

Extracts of Chlorella pyrenoidosa, Euglena gracilis var. bacillaris, spinach, barley, Dictyostelium discoideum and Escherichia coli...Full Text Available

1981-06-01

Light and Dark Controls of Nitrate Reduction in Wheat (Triticum aestivum L.) Protoplasts ¹

After preparation on self-generated Percoll gradients, avocado (Persea americana Mill, var. Fuerte and Hass) mitochondria retain a high proportion of cyanide-insensitive respiration,...Full Text Available

1982-11-01

1 2 3 4

Lack of Influence of Phytochrome on Membrane Permeability to Tritiated Water ¹

Protoplasts were isolated from the leaves of nitrate-cultured wheat (Triticum aestivum L. var. Frederick) seedlings. When incubated in the dark, protoplasts accumulated nitrite under...Full Text Available

1982-02-01

Kinetic Properties of Pyrophosphate:Fructose-6-Phosphate Phosphotransferase from Germinating Castor Bean Endosperm 1

The water permeability of tissues was investigated by measuring the efflux of ³HHO from previously loaded (in darkness) etiolated bean buds (Phaseolus vulgaris L. var. Red...Full Text Available

1976-02-01

Indoleacetic Acid and Abscisic Acid Antagonism

Pyrophosphate:fructose-6-phosphate phosphotransferase (PFP) was purified over 500-cold from endosperm of germinating castor bean (Ricinus commiunis L. var. Hale). The kinetic properties...Full Text Available

1984-02-01

GeneSrF and varSelRF: a web-based tool and R package for gene selection and classification using random forest

The phytochrome-mediated attachment of mung bean (Phaseolus vulgaris L., var. Oklahoma 612) root tips on glass is quickly affected by indoleactic acid and abscisic acid at concentrations...Full Text Available

1973-01-01

Effects of NaCl on Proline Synthesis and Utilization in Excised Barley Leaves 1

BackgroundMicroarray data are often used for patient classification and gene selection. An appropriate tool for end users and biomedical researchers should combine user friendliness...Full Text Available

Conversion of Phenylalanine into Tyrosine by Portulaca Callus ¹

Proline accumulation in NaCl-treated excised barley (Hordeum vulgare var Larker) leaves was studied. Leaves were treated by placing the cut end in NaCl solutions and allowing the salt...Full Text Available

1983-07-01

A Model for Predicting Ionic Equilibrium Concentrations in Cell Walls ¹

The incorporation of [¹⁴C]phenylalanine and [1,6-¹⁴C]shikimic acid into tyrosine was investigated in the callus of Portulaca grandiflora, var. JR (L.). By inhibiting...Full Text Available

1981-08-01

Performance of static var compensator control type thyristor controlled reactor and thyristor switched capacitor

Purified cell walls were prepared from roots of Horse bean (Vicia faba L., var. minor) and Yellow Lupine (Lupinus luteus L.). Two methods were used:...Full Text Available

1981-08-01

Metastability and dynamics of the shock-induced phase transition in iron

This paper has the objective of presenting the philosophy of Static Var Compensator (SVC) Control as well the necessary adjustments in the project of control system to guarantee suitable performance under different operating conditions. The verification on the performance of the SVC control has been done by Transient Network Analyzer (TNA/CEPEL) studies, commissioning tests and a factory tests. The SVC is the type of Thyristor Controlled Reactor (TCR) and Thyristor Switched Capacitor (TSC). (author) 3 refs., 12 figs.

1994-12-31

Synthesis, antifungal activity and antibacterial evaluation of some 3-piperazinylmethyl-5-aryl-1H-1,2,4-triazoles.

The shock-induced {alpha}(bcc){r_arrow}{var_epsilon}(hcp) transition in iron begins at 13 GPa on the Hugoniot. In the two-phase region above 13 GPa, the Hugoniot lies well above the equilibrium surface defined by G{sub {alpha}}=G{sub {var_epsilon}}, with G the Gibbs free energy. Also, the phase transition relaxation time {tau} is uncertain, with estimates ranging from {lt}50 ns to {approx}180 ns. Here we present an extensive study of these important aspects, metastability and dynamics, of the {alpha}-{var_epsilon} transition in iron. Our primary theoretical tools are (a) accurate theoretically based free energies for {alpha} and {var_epsilon} phases of iron and (b) accurate calculations of the wave evolution following planar impacts. We define metastable surfaces for forward and reverse transitions by the condition that the thermodynamic driving force G{sub {alpha}}{minus}G{sub ...

1997-02-01

Science.gov (United States)

Some new 3-piperazinylmethyl-5-aryl-1H-1,2,4-triazoles have been prepared and tested for their antifungal and antimicrobial activity. Among them, compounds 3g and 3h exhibited higher antifungal activity than ketoconazole against Cladosporium cladosporoides and Aspergillus niger respectively. PMID:9825120

1998-10-01

Recent process developments at the SOMAIRE uranium mill

Recent process developments at the COMINAK uranium mill

This paper reviews the mill flowsheet applied at the SOMAIR (Societe des Mines de l'Air) uranium mill in Niger. It focuses on the yellow cake quality improvements achieved by molybdenum and zirconium elimination through double yellow cake precipitation in tanks at first stage and through size/density control in a fluidized bed precipitator at second stage. Water saving aspects in the plant are also presented. (author)

2000-09-09

Removal of thorium from simulated acid process streams by fungal biomass: potential for thorium desorption and reuse of biomass and desorbent

This paper reviews the mill flowsheet applied at the COMINAK uranium mill (Compagnie Miniere d'Akouta) in Niger. For ore treatment, it focuses on the major improvements to the operations using sulfonitric pugging and solids/liquid separation using belt filter double filtration after leaching. The precipitation circuits have been improved with molybdenum elimination through caustic washing of the yellow cake. (author)

2000-07-01

High-resolution stratigraphy in a Miocene reservoir of the Niger delta

When thorium was biosorbed by biomass of Rhizopus arrhizus or Aspergillus niger it could be removed by treatment using carbonate solutions, but not by phosphates or distilled water. Desorption was rapid, reaching completion in 15 and 30 min respectively. Desorption efficiency was independent of the desorbent concentration above 0.05 mol dm[sup -3] but was strongly dependent on the biomass concentration, decreasing as the biomass concentration increased for both species. Biomass from both species could be regenerated by desorption using sodium carbonate solutions and reused for biosorption. In both species, the efficiency of biosorption and desorption fell as the number of exposures increased although there was an initial rise in desorption efficiency for R. arrhizus. Biosorption and desorption efficiencies of A. niger biomass showed the steeper decline but both were severely reduced in R. arrhizus after five treatments. There was also a ...

1992-01-01

Genetic Variation of Lodgepole Pine, Pinus contorta var. latifolia, Chemical and Physical Defenses that Affect Mountain Pine Beetle, Dendroctonus ponderosae, Attack and Tree Mortality

High-resolution sequence stratigraphy concepts are applied to Erema, a Miocene onshore field of the Niger delta. The field's production is decreasing and an up-to-date geological model is essential to monitor the production. We aim to show an approach, using subsurface data and sequence stratigraphic concepts, which results in a time-line (Maximum Flooding Surfaces) correlation scheme. This scheme is based upon a facies model and is destined to guide the study of the characterization of reservoir heterogeneities. Using the cored well as a reference point, the facies model consists of shoreface dunes (planar tabular cross-stratified sandstones) changing landward into fluvial distributary deposits (through cross-stratified sandstones) via a tide-influenced coastal plain facies. The stacking pattern of genetic units shows a seaward stepping phase at the reservoir scale (sixty metres thick) with an abrupt deepening at the top of the reservoir. The proposed ...

1994-06-30

British Library Electronic Table of Contents (United Kingdom)

Plant secondary chemistry is determined by both genetic and environmental factors, and while large intraspecific variation in secondary chemistry has been reported frequently, the levels of genetic variation of many secondary metabolites in forest trees in the context of potential resistance against pests have been rarely investigated. We examined the effect of tree genotype and environment/site on the variation in defensive secondary chemistry of lodgepole pine, Pinus contorta var. latifolia, against the fungus, Grosmannia clavigera (formerly known as Ophiostoma clavigerum), associated with the mountain pine beetle, Dendroctonus ponderosae. Terpenoids were analyzed in phloem samples from 887, 20-yr-old trees originating from 45 half-sibling families planted at two sites. Samples were coll...

2011-01-01

Effect of postharvest water deficit stress on gene expression in heads of broccoli (Brassica oleracea var. italica)

British Library Electronic Table of Contents (United Kingdom)

Harvested plant organs such as heads of broccoli (Brassica oleracea L. var. italica) experience a range of stresses that can lead to premature reduction in quality and eventual senescence. Understanding plant responses to stress may open up novel opportunities to extend postharvest life. One of the first stresses experienced by harvested organs is likely to be water deficit stress since severance of the vascular system halts the normal flux of water into the tissue. For broccoli branchlets with their cut ends held in water, transcriptome analysis based on hybridization of broccoli floret mRNA to a heterologous Arabidopsis microarray revealed that the transcript abundance of 431 genes reliably changed within 48h of harvest. Of these, transcripts of 146 genes increased and 34 genes decreased...

2011-01-01

Aspects of the carbon activated production since three Pinus species; Aspectos da producao de carvao ativado a partir de tres especies de pinus SPP

Evolution of oil-generative window and oil and gas occurrence in Tertiary Niger delta basin/sup 1/

Activated charcoal was produced from sawdust of Pinus caribaea var. caribaea, pinus caribaea var. honduenais and pinus cocarpa, with the objective of studying a alternative of more economic uses for forest residues and the products of the first thinning. A chemical process was utilized based on Zn Cl{sub 2} at temperature of 700 deg C and 450 deg C. It was concluded that the temperature of 700 Celsius produced a activated charcoal with better quality and greater adsorption capacity. The temperature of 450 deg C produced a material with adsorption properties for utilization where greater adsorption capacity is not needed. The production of activated charcoal is possible from the three species of tropical pinus studied. (author). 16 refs., 5 tabs

1987-12-31

Evolution of oil-generative window (OGW) in Niger delta basin

Assuming a simple model of delta development involving progradation and uniform burial at 500 m/m.y. (1,640 ft/m.y.) to present depths, oil-genesis nomographs derived from the time-temperature index (TTI) method were constructed for geothermal gradients ranging from 2.2/sup 0/ to 5.1/sup 0/ C/100 m (1.2/sup 0/-2.8/sup 0/ F/100 ft) of the Niger delta and used in mapping the positions (depth, temperature) of the top of the oil-generative window (OGW) at various times between 40 m.y.B.P. and the present. During the active subsidence phase, oil generation within any megasedimentary unit was initiated at a temperature of 140/sup 0/-146/sup 0/C (284/sup 0/-294.8/sup 0/F) and depth of 3,000-5,200 m (9,843-17,060 ft) within 7-11 m.y. after deposition of the potential source rocks. After cessation of subsidence, vertical upward movement of the OGW by 800-1,600 m (2,625-5,249 ft) was accompanied by a temperature lowering of 23/sup 0/-54/sup 0/C (41/sup 0/-97/sup 0/F), ...

1984-11-01

Polygalacturonase ?-Subunit Antisense Gene Expression in Tomato Plants Leads to a Progressive Enhanced Wound Response and Necrosis in Leaves and Abscission of Developing Flowers

Assuming a simple model of delta development involving progradation and uniform subsidence to present depths (rate, 500 m/m.y.; 1640 ft/m.y.), oil-genesis nomographs derived from the TTI method were constructed for various geothermal gradients of the Niger delta (2.2., 2.5., 2.9, 3.6, 4.0, 4.4, and 4.7/sup 0/C/100 m) and utilized in mapping the positions (depth, temperature) of the top of the oil-generative window (OGW) at arbitrarily selected times (40 m.y.B.P., 30 m.y.B.P., 15 m.y.B.P., and the present). About 200 data points were evaluated. During the active subsidence phase, oil generation within any megastructure was initiated at a temperature of 140 to 146/sup 0/C (284 to 294/sup 0/F) and depth of 3000 to 5200 m (9842 to 17,060 ft) within 7 to 11 m.y. after deposition of the potential source rocks. After cessation of subsidence, upward movement of the OGW by 800 to 1600 m (2624 to 5249 ft) was accompanied by a temperature lowering of 23 to 54/sup 0/C (73 to ...

1983-03-01

1 2 3 4

Induction of Porphyrin Synthesis in Etiolated Bean Leaves by Chelators of Iron ¹²

Tomato (Lycopersicon esculentum var. Better Boy) plants were transformed with a tomato leaf wound-inducible polygalacturonase (PG) β-subunit gene in the antisense orientation...Full Text Available

2003-10-01

Flavonols and an oxychromonol from Piliostigma reticulatum

Primary leaves of 7- to 9-day-old etiolated seedlings of Phaseolus vulgaris L. var. Red Kidney infiltrated in darkness with aqueous solutions of α, α′-dipyridyl,...Full Text Available

1974-02-01

British Library Electronic Table of Contents (United Kingdom)

The leaf extract from the plant Piliostigma reticulatum was found to exhibit antimicrobial activity against some bacteria and fungi such as Staphylococcus aureus (NCTC 6571), Escherichia coli (NCTC 10418), Bacillus subtilis (NCTC 8236), Proteus vulgaris (NCTC 4175), Aspergillus niger (ATCC 10578) and Candida albicans (ATCC 10231). Upon investigation of the chemical constituents present in the leaf extract, a total of seven compounds were isolated and their structures were unambiguously established by spectroscopic methods including HR-MS and NMR spectrometry. Four of the isolated compounds were novel, namely 6-C-methyl-2-p-hydroxyphenyloxychromonol (piliostigmol), 1, 6,8-di-C-methylquercetin-3,3prime,7-trimethyl ether, 2, 6,8-di-C-methylquercetin-3,3prime-dimethyl ether, 3 and 3prime,6,8,-...

2008-01-01

Collection and characterization of yellow endosperm sorghums from West Africa for biofortification

British Library Electronic Table of Contents (United Kingdom)

Sorghum is a good candidate crop for breeding to increase provitamin A, i.e., biofortification. Yellow endosperm sorghums contain carotenoids, including precursors of vitamin A, and sorghum is a major staple crop in areas of Asia and Africa where vitamin A deficiency is prevalent. Our objective was to collect and characterize yellow endosperm sorghums as a potential new source of genetic diversity to increase provitamin A content. A set of 164 landraces were collected from southern Niger and northern Nigeria. The most important use of these cultivars was as food. The endosperm exhibited a significant variation in yellow intensity. Lutein, zeaxanthin and ?-carotene were the most abundant carotenoids in the ten landraces with the most intense yellow color. Cluster analysis, principal coordin...

2009-01-01

Biosorption of heavy metals on fungal biomass

A research approach supporting domestication of Baobab (Adansonia digitata L.) in West Africa

A method of using fungi in removing heavy metal from wastewater was discussed. Fungi for this purpose can be obtained inexpensively, and on a constant basis from industrial fermentation processes. The biosorption of lead, cadmium and nickel on fungal stock cultures, was investigated. In these experiments, the fungal stock used was Aspergillus niger and Rhizopus stolonfier. Alkali pre-treatment of the fungal biomass improved the metal biosorptive capacity in comparison to live cells. The effect of alkali treatment, however, varied,showing highest biosorptive capacity for lead and least for nickel. Results showed that metal biosorption of metallic ions increased with an increase in pH from 3.2 to 4.0. Equilibrium times of five hours were observed for the biosorption of lead and cadmium, while the equilibrium time for nickel was three hours. 10 refs., 3 tabs., 7 figs.

1996-09-01

British Library Electronic Table of Contents (United Kingdom)

The Baobab tree (Adansonia digitata L.) is a key multipurpose species for the African region. In the recent years there has been an extended commercial interest for different A. digitata products. As a spectacular African key species there has been a growing interest from NGO?s and various research groups. A research group, focussing on the following countries Burkina Faso, Mali and Niger, has participated in a concerted research action with cross counter disciplinary cooperation between plant physiology, population genetics, tree breeding, food science, and socioeconomics. This paper presents a review and the way knowledge gaps are being addressed using the above mentioned approach. The overall work was initiated in 2005?2006 when a large collection of A. digitata seeds was carried out in...

2011-01-01

Fuel/propellant mixing in an open-cycle gas core nuclear rocket engine

Chemical Composition and Nutritional Value of Unripe Banana Flour (Musa acuminata, var. Nanic?o)

A numerical investigation of the mixing of gaseous uranium and hydrogen inside an open-cycle gas core nuclear rocket engine (spherical geometry) is presented. The gaseous uranium fuel is injected near the centerline of the spherical engine cavity at a constant mass flow rate, and the hydrogen propellant is injected around the periphery of the engine at a five degree angle to the wall, at a constant mass flow rate. The main objective is to seek ways to minimize the mixing of uranium and hydrogen by choosing a suitable injector geometry for the mixing of light and heavy gas streams. Three different uranium inlet areas are presented, and also three different turbulent models (k-var-epsilon model, RNG k-var-epsilon model, and RSM model) are investigated. The commercial CFD code, FLUENT, is used to model the flow field. Uranium mole fraction, axial mass flux, and radial mass flux contours are obtained. copyright 1997 American Institute of Physics.

1997-01-01

British Library Electronic Table of Contents (United Kingdom)

Banana flour obtained from unripe banana (Musa acuminata, var. Nanic?o) under specific drying conditions was evaluated regarding its chemical composition and nutritional value. Results are expressed in dry weight (dw). The unripe banana flour (UBF) presented a high amount of total dietary fiber (DF) (56.24?g/100?g), which consisted of resistant starch (RS) (48.99?g/100?g), fructans (0.05?g/100?g) and DF without RS or fructans (7.2?g/100?g). The contents of available starch (AS) (27.78?g/100?g) and soluble sugars (1.81?g/100?g) were low. The main phytosterols found were campesterol (4.1?mg/100?g), stigmasterol (2.5?mg/100?g) and ?-sitosterol (6.2?mg/100?g). The total polyphenol content was 50.65?mg GAE/100?g. Antioxidant activity, by the FRAP and ORAC methods, was moderated, being 358.67 an...

2011-01-01

Assessing the profitability of reactive power compensation devices

Ultraviolet radiation for the sterilization of contact lenses

A probabilistic method for assessing the profitability of reactive power compensation devices such as capacitors, static VAR compensators and generators, which improve network security, was described. Since network development is limited by environmental constraints, power networks are operated close to their limits. Because of this fact transmission network planning increasingly relies on techno-economic models to improve network security and profitability. The proposed method consists of analyzing large numbers of constrained power system states, extracted from power system simulation exercises. The paper describes details of the method and provides an example of a numerical application on a part of the French power transmission system. 10 refs., 8 figs.

1997-12-31

Ultraviolet radiation for the sterilization of contact lenses

Two sources of ultraviolet (UV) radiation with peak wavelengths in the UV-C or UV-B ranges were compared for their ability to sterilize contact lenses infected with Pseudomonas aeruginosa, Streptococcus pneumoniae, Acanthamoeba castellani, Candida albicans, and Aspergillus niger. Also examined was the effect of prolonged UV light exposure on soft and rigid gas permeable (RGP) contact lenses. The UV-C lamp (253.7 nm, 250 mW/cm2 at 1 cm) was germicidal for all organisms within 20 minutes but caused destruction of the soft lens polymers within 6 hours of cumulative exposure. UV-C caused damage to RGP lenses in less than 100 hours. The UV-B lamp (290-310 nm, 500 mW/cm2 at 1 cm) was germicidal for all organisms tested (except Aspergillus) with a 180-minute exposure and caused less severe changes in the soft lens polymers than did the UV-C lamp, although cumulative exposure of 300 hours did substantially weaken the soft lens material. RGP materials were minimally ...

1990-10-01

The expression of stratigraphic surfaces and deltaic geometries during the scale change from well data to seismic data; Traduction des surfaces stratigraphiques et des geometries deltaiques lors du passage de l`echelle puits a l`echelle sismique

Mechanism of biosorption of Heavy metals by mucor rouxii

The sedimentary geometry is determined by several types of stratigraphic surfaces: transgressive surfaces (TS), maximum flooding surfaces (MFS) and downward shift surfaces (DS). They are organized hierarchically into major and minor surfaces from the facies stacking-pattern. These surfaces which are observable on well logs and cores structure the sedimentary architecture and are, therefore, the best candidates to form major seismic reflectors. The well (logs and cores) to seismic (surface seismic) passage involves inherently a change of observation scale. That is from a high resolution sequence stratigraphy (metric to pluri-metric) to a sequence stratigraphy s.l. (decametric to pluri-decametric). This passage is composed of two phases. The first phase consists of the validation of density and sonic logs whose product corresponds to the acoustic impedance. The second phase allows for the modelling of the geological cross section of a field in a synthetic seismic section which is ...

1996-12-31

Management of storage rot in onion through gamma irradiation and chemicals

Fungi such as Aspergillus niger and Mucor rouxii are capable of removing heavy metals from aqueous solutions. The role various functional groups play in the cell wall of M. rouxii in metal biosorption of lead, cadmium, nickel and zinc was investigated in this paper. The biomass was chemically treated to modify the functional carboxyl, amino and phosphate groups. These modifications were examined by means of infrared spectroscopy. It was found that an esterification of the carboxyl groups and phosphate and a methylation of the amine groups significantly decreased the biosorption of the heavy metals studied. Thus, the carboxylate, amine and phosphate groups were recognized as important in the biosorption of metal ions by M. rouxii biomass. The role the lipids fraction play was not significant. The study showed that Na, K, Ca and Mg ions were released from the biomass after biosorption of Pb,Cd,Ni and Zn, indicating that ion exchange was a key mechanism in the ...

2008-08-15

Induction of mutation in Trichoderma viride for conversion of natural cellulose into glucose

Pre-harvest sprays of bavistin (50% carbendazim) at 100, 200 and 400 g a.i/ha were ineffective in the control of Aspergillus niger van Tieghem in onion. The combination of gamma irradiation (0.1 kGy) with bavistin dust (0.33g a.i/kg bulbs) was effective to an extent of about 79% in reducing storage losses due to sprouting and rottage. This combination treatment was better than dust treatment alone and highly cost effective. Bavistin, when used as pre-harvest spray, did not leave any residue in the tissues, whereas the compound was seen to move deep into the tissues, when used as post-harvest dust treatment. Higher concentrations of carbendazim residues (2.1-3.4 mg/kg bulb) were detected in the outer scales of the bulbs, as compared to that of inner scales (0.6-1.6 mg/kg), and the residue decreased slightly with passage of storage time. (author). 19 refs., 2 tabs.

Local chromatin structure of heterochromatin regulates repeatedDNA stability, nucleolus structure, and genome integrity

The production of cellulolytic enzymes from fungi has been extensively studied. Several mutants of Trichoderma reesei were selected. Most of the studies were carried out on T. reesei, T. viride, T. harzianum, Penicillium funiculosum, Altemaria alternata. Aspergillus phoenicis, A. ustus, A. tamarii, A. japonicus, and A. niger. T. koningii is one of the most active producers of the so-called C, factor, which is indispensable for the rapid and extensive attack on crystal-line cellulose. However, Trichodenna is known to excrete only small amounts of {beta}-glucosidase. Therefore, Trichoderma is supplemented with {beta}-glucosidase from Aspergillus to increase the saccharification rate of cellulose to glucose as the main sugar. Induction of mutations in Trichodenna spp. rather than T. viride as a tool for the enhancement of {beta}-glucosidase activity was reported. Unfortunately, T. reesei is a poor producer of {beta}-glucosidase. On the other hand, T. harzianum M{sub ...

1991-12-31

Wood-polymer composites. Polymerization of methyl-metacrylate in Pinus strobus var. chiapensis wood by gamma radiation

Heterochromatin constitutes a significant portion of the genome in higher eukaryotes; approximately 30% in Drosophila and human. Heterochromatin contains a high repeat DNA content and a low density of protein-encoding genes. In contrast, euchromatin is composed mostly of unique sequences and contains the majority of single-copy genes. Genetic and cytological studies demonstrated that heterochromatin exhibits regulatory roles in chromosome organization, centromere function and telomere protection. As an epigenetically regulated structure, heterochromatin formation is not defined by any DNA sequence consensus. Heterochromatin is characterized by its association with nucleosomes containing methylated-lysine 9 of histone H3 (H3K9me), heterochromatin protein 1 (HP1) that binds H3K9me, and Su(var)3-9, which methylates H3K9 and binds HP1. Heterochromatin formation and functions are influenced by HP1, Su(var)3-9, and the RNA interference (RNAi) ...

2007-05-05

Selection of ancillary data to derive production management units in sweet corn (Zea Mays var. rugosa) using MANOVA and an information criterion

To obtain Pinus wood-plastic composites, wood samples were impregnated with methyl methacrylate and polymerized by the use of gamma rays from a /sup 60/Co at different dose exposure and total dose. The best percentage of polymerization was obtained with the exposure of 2.0 MR of gamma radiation. It was found that the impregnation and polymerization, determined by the density values along the samples were uniform. The density became 2.6 times higher in relation to the control samples. The storage of the impregnated wood samples showed losses of the monomer, even when wrapped with aluminum or polyethylene film. It is recommended that the wood samples should be irradiated soon after impregnation.

1984-12-01

British Library Electronic Table of Contents (United Kingdom)

In production systems where high-resolution harvest data are unavailable there is often a reliance on ancillary information to generate potential management units. In these situations correct identification of relevant sources of data is important to minimize cost to the grower. For three fields in a sweet corn production system in central NSW, Australia, several sets of high-resolution data were obtained using soil and crop canopy sensors. Management units were derived by k-means classification for 2?5 classes using three approaches: (1) with soil data, (2) with crop data and (3) a combination of both soil and crop data. Crop quantity and quality were sampled manually, and the sample data were related to the different management units using multivariate analysis of variance (MANOVA). The ...

2011-01-01

Quantitative easing works: Lessons from the unique experience in Japan 2001-2006

British Library Electronic Table of Contents (United Kingdom)

Abstract: The current financial crisis has now led most major central banks to rely on quantitative easing. The unique Japanese experience of quantitative easing is the only experience which enables us to judge this therapy's effectiveness and the timing of the exit strategy. In this paper, we provide a new empirical framework to examine the effectiveness of Japanese monetary policy during the ''lost'' decade and quantify the effect of quantitative easing on Japan's activity and prices. We combine advantages of Markov-switching VAR methodology with those of factor analysis to establish two major findings. First, we show that the decisive change in regime occurred in two steps: it crept out from late 1995 and established itself durably in February 1999. Second, we show for the first time th...

2011-01-01

On the real effects of inflation in open economies: theory and empirics

British Library Electronic Table of Contents (United Kingdom)

Based on the quarterly data from four open economies (the US, the UK, Canada, and Italy) and estimated correlations and impulse responses within the traditional vector autoregressive (VAR) analysis, we find that inflation, both in the short and long term, negatively affects consumption and investment, and has a positive influence on the current account. We propose an infinite-horizon optimizing model of an open economy with a fixed rate of time preference that explains these empirics. In this type of economy, households consume both durable and non-durable goods, firms operate under costly investment, and all the transactions involving consumption and investment are subject to cash-in-advance (CIA) constraints. Employing the new ?sign restriction? identification procedure due to Uhlig (J M...

2010-01-01

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Corrosion experiments and materials developed for the Japanese HLM systems

British Library Electronic Table of Contents (United Kingdom)

The static corrosion tests in lead-bismuth eutectic (LBE) were conducted from 450degreeC to 600degreeC to understand corrosion behavior and develop corrosion resistant materials for heavy liquid metal systems. While increase of Cr content in steels enhances corrosion resistance in LBE, the effect approaches a constant value above 12wt% of Cr. Corrosion depth in LBE increases with increasing temperature and corrosion attack becomes severe above 550degreeC even under the condition of high oxygen concentration. Nickel dissolution and Pb-Bi penetration occur in 316SS and JPCA above 550degreeC under the condition of high oxygen concentration. When oxygen concentration decreases below the level of Fe oxide formation, corrosion attack on these steels also becomes violent due to dissolution of var...

2011-01-01

Beyond the tropics: forest structure in a temperate forest mapped plot

British Library Electronic Table of Contents (United Kingdom)

Abstract Question: How do the diversity, size structure, and spatial pattern of woody species in a temperate (Mediterranean climate) forest compare to temperate and tropical forests? Location: Mixed evergreen coastal forest in the Santa Cruz Mountains, California, USA. Methods: We mapped, tagged, identified, and measured all woody stems (?1 cm diameter) in a 6-ha forest plot, following Center for Tropical Forest Science protocols. We compared patterns to those found in 14 tropical and 12 temperate forest plots. Results: The forest is dominated by Douglas-fir (Pseudotsuga menziesii) and three species of Fagaceae (Quercus agrifolia, Q. parvula var. shrevei, and Lithocarpus densiflorus), and includes 31 woody species and 8180 individuals. Much of the diversity was in small-diameter shrubs,...

2010-01-01

Projected change in climate thresholds in the Northeastern U.S.: implications for crops, pests, livestock, and farmers

Antifungal activity of the extracts and neolignans from Piper regnellii (Miq.) C. DC. var. pallescens (C. DC.) Yunck

Most prior climate change assessments for U.S. agriculture have focused on major world food crops such as wheat and maize. While useful from a national and global perspective, these results are not particularly relevant to the Northeastern U.S. agriculture economy, which is dominated by dairy milk production, and high-value horticultural crops such as apples (Malus domestica), grapes (vitis vinifera), sweet corn (Zea mays var. rugosa), cabbage (Brassica oleracea var. capitata), and maple syrup (sugar maple, Acer saccharum). We used statistically downscaled climate projections generated by the HadCM3 atmosphere-ocean general circulation model, run with Intergovernmental Panel on Climate Change future emissions scenarios Alfi (higher) and B1 (lower), to evaluate several climate thresholds of direct relevance to agriculture in the region. A longer (frostfree) growing season could create new opportunities for farmers with enough capital to take ...

2008-07-01

Voltage and reactive power control by means of static compensators of vars in electric power systems; Control de voltaje y potencia reactiva mediante compensadores estaticos de Vars en sistemas electricos de potencia

Piper regnellii (Miq.) C. DC. var. pallescens (C. DC.) Yunck (Piperaceae) is a medicinal plant traditionally used in Brazil to treat infectious diseases. The extracts obtained from the leaves of P. regnellii were investigated for their antifungal activities against the yeasts Candida albicans, C. krusei, C. parapsilosis, and C. tropicalis. The EtOAc extract presented gnificant activity against Candida albicans with MIC at 125 {mu}g mL{sup -1}, and a moderate activity against both C. krusei and C. parapsilosis with MIC at 500 {mu}g mL{sup -1}. Candida tropicalis was not inhibited by this extract at concentrations as high as 1000 {mu}g mL{sup -1}. Based on these findings, the EtOAc extract was fractionated by silica gel column chromatography into nine fractions. The hexane and CHCl{sub 3} fractions showed varied levels of antifungal activity against all test yeasts. Further column chromatography separation of the hexane fraction afforded the pure compounds ...

2005-11-15

Total phenolics and antioxidant activity of five medicinal plant; Fenois totais e atividade antioxidante de cinco plantas medicinais

In this thesis a study is made of the of voltage characteristics and reactive power control in the transmission network of the Electric Power Systems (EPS) with static compensators of VARs (SCVs). The necessity of voltage and reactive power control and the application of SCVs as a solution means for three representative operation stages of the EPS, considering balanced operation conditions and fundamental frequency is analyzed: Operation in the presence of incremental voltage changes, quasi-stationary operation or steady state and behavior at the occurrence of big disturbances. The application of SCVs to systems of integral transmission is in general a closed loop control system, reason why the analysis of the interaction of the system EPS-SCV is considered as an essential part of the voltage and reactive power control study. Firstly, the response analysis of the control loop is made for incremental voltage changes, representing the power system by means of its ...

1987-07-01

The preparation of neem oil microemulsion (Azadirachta indica) and the comparison of acaricidal time between neem oil microemulsion and other formulations in vitro

This paper describes total phenolics content and antioxidant activity in the ethanolic extract of leaves, bark and roots of five medicinal plants: Terminalia brasiliensis Camb., Terminalia fagifolia Mart. and Zucc., Copernicia cerifera (Miller) H.E. Moore, Cenostigma macrophyllum Tul. var. acuminata Teles Freire and Qualea grandiflora Mart. The total phenolics content of the plant extracts, determined by the Folin-Ciocalteu method, varied from 250.0 {+-}8,2 to 763,63 {+-}13.03 mg of gallic acid equivalent/g dry EtOH extract. The antioxidant activity of extracts was evaluated using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay system. Extract of bark from T. brasiliensis, the most active, with an EC{sub 50} value of 27.59 {+-} 0.82 {mu}g/mL, was comparable to rutin (EC{sub 50} = 27.80 {+-} 1.38) and gallic acid (EC{sub 50} = 24.27 {+-} 0.31), used as positive controls. The relationship between total phenolic content and antioxidant activity was positive and ...

2007-03-15

British Library Electronic Table of Contents (United Kingdom)

The preparation of neem oil microemulsion and its acaricidal activity in vitro was developed in this study. In these systems, the mixture of Tween-80 and the sodium dodecyl benzene sulfonate (SDBS) (4:1, by weight) was used as compound surfactant; the mixture of compound surfactant and hexyl alcohol (4:1, by weight) was used as emulsifier system; the mixture of neem oil, emulsifier system and water (1:3.5:5.5, by weight) was used as neem oil microemulsion. All the mixtures were stired in 800rpm for 15min at 40^oC. The acaricidal activity was measured by the speed of kill. The whole lethal time value of 10% neem oil microemulsion was 192.50min against Sarcoptes scabiei var. cuniculi larvae in vitro. The median lethal time value was 81.7463min with the toxicity regression equations of Y=-6.0...

2010-01-01

Small heat shock protein LimHSP16.45 protects pollen mother cells and tapetal cells against extreme temperatures during late zygotene to pachytene stages of meiotic prophase I in David Lily

British Library Electronic Table of Contents (United Kingdom)

Plant meiotic prophase I is a complicated process involving the late zygotene and pachytene stages, both crucial for completing synapsis and recombination. Using David Lily (Lilium davidii var. Willmottiae) as our research material, we performed suppression subtractive hybridization to construct EST library of anthers at various stages of development by the pollen mother cells. From this library, we identified small heat shock protein LimHSP16.45 was highly expressed during the late zygotene to pachytene stages. Our results also showed that LimHSP16.45 was almost specifically expressed in the anther compared with the root, stem, or leaf, and in situ expression of LimHSP16.45 mRNAs showed strong signals in the pollen mother cells and tapetal cells. LimHSP16.45 could be induced by heat and c...

2011-01-01

Phytoavailability and fractionation of copper, manganese, and zinc in soil following application of two composts to four crops

Biological control of take-all in wheat by endophytic Bacillus subtilis E1R-j and potential mode of action

Two experiments were conducted to evaluate the effect of compost addition to soil on fractionation and bioavailability of Cu, Mn, and Zn to four crops. Soils growing Swiss chard (Beta vulgaris var. cicla L.) and basil (Ocimum basilicum L.) were amended (by volume) with 0, 20, 40, and 60% Source-Separated Municipal Solid Waste (SS-MSW) compost, and dill (Anethum graveolens L.) and peppermint (Mentha X piperita L.) were amended with 0, 20, 40, and 60% of high-Cu manure compost (by volume). The SS-MSW compost applications increased the concentration of Cu and Zn in all fractions, increased Mn in acid extractable (ACID), iron and manganese oxides (FeMnOX), and organic matter (OM) fractions, but decreased slightly exchangeable-Mn. Addition of 60% high-Cu manure compost to the soil increased Cu EXCH, ACID, FeMnOX, and OM fractions, but decreased EXCH-Mn, and did not change EXCH-Zn. Addition of both composts to soil reduced bioavailability and transfer factors for Cu and ...

2004-09-01

British Library Electronic Table of Contents (United Kingdom)

The bacterial strain E1R-j, isolated as an endophyte from wheat roots, exhibited high antifungal activity to Gaeumannomyces graminis var. tritici (Ggt). Strain E1R-j was identified as Bacillus subtilis based on morphological, physiological and biochemical methods as well as on 16S rDNA analysis. This strain inhibited mycelium growth in vitro of numerous plant pathogenic fungi, especially of Ggt, Coniothyrium diplodiella, Phomopsis sp. and Sclerotinia sclerotiorum. In greenhouse experiments, soil drenches with cell densities of 106, 109 and 1012CFU ml-1 E1R-j reduced significantly take-all disease, caused by Ggt, in wheat seedling by 62.6%, 68.6% and 70.7%, respectively, compared to the inoculated control, 4weeks after sowing. Growth parameters such as lengths and fresh weights of roots and...

2009-01-01

Multivariate statistics in the identification of unknown nuclear material

Determination of volatile metabolites originating from mould growth on wall paper and synthetic media.

The identification, and hence origin determination, of unknown nuclear material that might be found undeclared away from designated locations in the nuclear fuel cycle, is an important task in the frame of nuclear forensics. Material with forensic importance can be found at the microscopic level as particles in environmental samples indicating possible clandestine production of fissile material, and as bulky samples in the case of illicit trafficking of nuclear material. The objective of this work is to present, at a theoretical level, an isotopic finger-printing methodology which would determine the origin of unknown nuclear material with forensic importance. This is demonstrated for the case when the unknown nuclear material is spent nuclear fuel. The methodology is based on multivariate statistics, such as cluster and factor analysis, complemented by spent fuel isotopic composition simulations using the zero-dimensional depletion computer code ORIGEN2. A major source of error in the ...

2004-10-25

Science.gov (United States)

Microbial volatile organic compounds (MVOCs) emitted from the mould species Penicillium expansum, P. chrysogenum, Aspergillus versicolor, A. fumigatus, A. niger and Cladosporium cladosporoides were analyzed by means of solid phase microextraction (SPME) and GCMS. The mould species were cultivated on the synthetic agar dichloran chloramphenicol (DG 18) and on wet wall paper. The production of MVOCs was monitored over several weeks to detect changes in the emission rates between the initial stage and later periods of growth. The cultivation on the synthetic agar resulted in MVOC patterns with a wide variety of signals. In contrast, the growth on wet wall paper led to changed MVOC patterns with less signals. The emission rates were drastically reduced. Components emitted by all six fungi species on wall paper were 2-pentanol and 2-pentanone. 1-Octen-3-ol was emitted by five fungi species. 2-Pentanol was only detected in considerable amounts during the first days of ...

2008-06-05

beta-Lactamases among extended-spectrum beta-lactamase (ESBL)-resistant Salmonella from poultry, poultry products and human patients in The Netherlands

DEFF Research Database (Denmark)

Objectives: The purpose of this work was to study the genetic determinants responsible for extended-spectrum beta-lactamase (ESBL) resistance of Salmonella isolated from Dutch poultry, poultry meat and hospitalized humans. Methods: Thirty-four ESBL-resistant Salmonella isolates from The Netherlands were tested towards 21 antimicrobial agents. PCR and sequencing were used to determine the underlying genetic determinants responsible for the ESBL phenotypes. The transferability of the ESBL phenotypes was tested by conjugation to a susceptible Salmonella enterica serovar Dublin and plasmid purification, restriction fragment length polymorphism (RFLP) and pulsed-field gel electrophoresis (PFGE) were employed to further characterize a subset of the isolates. Results: A great genetic diversity was seen among the isolates. The bla(TEM-52) gene was most predominant and was found among Salmonella enterica serovars Blockley, Thomson, London, Enteritidis phage type 14b, Paratyphi B, Virchow and ...

2005-01-01

Responses of aquatic organisms to metal pollution in a lowland river in Flanders: A comparison of diatoms and macroinvertebrates

Contribution \\`{a} l'etude des binaires des types F, G, K, M IX. HD 191588, nouvelle binaire spectroscopique \\`{a} raies simples de type RS Cvn, systeme triple

The role of macroinvertebrates and diatoms as indicator for metal pollution was investigated by assessing both biota along a metal gradient in the Belgian river the Dommel. Macroinvertebrates and diatoms were sampled in summer and winter and physical-chemical characteristics of the water were measured at four different sample periods and related to sediment characteristics. Although metal concentrations, except cadmium, in the water nowhere exceeded water quality standards, high metal concentrations were measured in the sediment, indicating historical contamination of the Dommel. At the sites that were situated downstream of the pollution source, high levels of conductivity and chloride were measured in the water. Redundancy Analysis (RDA) indicated pH, phosphate and zinc as the significant environmental variables explaining each respectively 7.7%, 11.6% and 22.6% of the macroinvertebrate community composition. Two clusters could be separated, with Gammarus pulex, Leptocerus ...

2008-12-15

CERN Document Server

An accident of misidentification has brought to light the interesting system HD 191588, a new RS CVn-type spectroscopic binary. A radial-velocity study of the primary star, the only seen component, carried out at the Observatoire de Haute-Provence with the Coravel instrument and subsequently at the Cambridge Observatories with a similar one, reveals two orbital motions: a short-period orbit (60 days) and a long-period one (about 4.5 years), so this star is a triple system. The following orbital elements are obtained: (1) for the long-period orbit P = 1667+/-17 days, T = 50901 +/-67 MJD, Gamma = +2.09 +/-0.07 km/s, K = 2.51 +/-0.13 km/s, e = 0.18 +/-0.04, omega = 228deg +/- 14 deg, a1 sin i = 56.7 +/- 3.0 Gm, f(m) = 0.0026 +/-0.0004 M_sun, and (2) for the short-period orbit P = 60.0269 +/-0.0016 days, T = 50482.6 +/-3.3 MJD, gamma is var., K = 24.03 +/- 0.09 km/s, e = 0.012 +/-0.004, omega = 233 deg +/-19deg, a1 sin i = 19.83 +/-0.07 Gm, f(m) = 0.0865 +/-0.0009 ...

2003-01-01

Computerized tomography-guided neurolytic splanchnic nerve block