ISOLATION AND IDENTIFICATION OF IRONSULPHUR
OXIDZING THIOBACIULLI FROM
IRAN ENVRONMENTS
text
article
1997
eng
Two hundred samples were taken from various sites in Iran, including coal storage areas, waste water in the Tabas and Zirab coal mines, and sulphur containing acid springs in Ramsar and Abask , and were screened for Thlobacillus ferruuxidans. During this investigation , seven strains were isolated which could oxidize sdphm , pyrite , thiosdphate and ferrous iron as the sole energy source. Macroscopic, microscopic and biochemical studies showed that the isolates were T. f e r r ooxidans
Journal of Sciences, Islamic Republic of Iran
University of Tehran
1016-1104
8
v.
3
no.
1997
https://jsciences.ut.ac.ir/article_31248_1ae1ce1f984a64eede9b43824434a011.pdf
GROWTH RESPONSE AND CATION -
INTERACTION IN HIPPOPHAE RHAMNOIDES L
text
article
1997
eng
The interaction between sodium and calcium, magnesium and calcium and the
combined effect of sodium, magnesium and calcium was observed on the growth and
ion uptake of Hippophae rhamnoides L. The results demonstrated that an addition of
sodium with calcium, (set a, Na 2.5 + Ca 5 mM) showed prominent increase in fresh
weight of roots and shoots. The dry weight (average) of roots decreased and that of
shoots increased but the percent dry weight of both roots and shoots decreased
following an increase in percent water content. An addition of magnesium with
calcium, (set b, Mg 2.5 + Ca 5 mM) showed an increase in fresh and dry weight
(average and percentage of root and shoot), while percent water content decreased.
The addition of sodium and magnesium with calcium , (set c, Na 2.5 +Mg 2.5 + Ca
5 mM) showed an increase in fresh and dry weight (average) of roots and shoots, while percentage dry weight of roots decreased and that of shoots increased and the
percentage water content of roots increased and that of shoots decreased. The
treatments of sets a, b and c increased the uptake of all ions studied. However, a
difference in ion uptake within treatments occurred. It appears that the presence of
calcium mitigates the adverse effects of sodium and magnesium by preventing their
uptake and enhances the uptake of potassium
Journal of Sciences, Islamic Republic of Iran
University of Tehran
1016-1104
8
v.
3
no.
1997
https://jsciences.ut.ac.ir/article_31249_f2848db8d343db9371dd09349b37f438.pdf
ELECTROCHEMICAL BEHAVIOUR OF U(V1)
NITRATE IN CHLOROFORM AT A MERCURY
ELECTRODE
THE DEPENDENCE ON SUPPORTING
ELECTROLYTE
text
article
1997
eng
The mechanistic aspects of the electrochemical reduction of U(V1) nitrate at a
mercury electrode in chloroform, using three different supporting electrolytes, are
described. In the presence of tetrabutylarnmonium perchlorate (TBAP) as a neutral
electrolyte, UO (NO ) , reduced in two irreversible electrochemical steps to form a U(V1)-U(V) binuclear complex and U(IV), respectively. In the presence of 0.75 M
piperidinium perchlorate (PP) + 0.25 M piperidine (P) as supporting electrolyte, the
reduction of U0 ( NO ) occurred according to a one-electron irreversible process to U (V). The same behaviour was observed in the presence of 0.5 M tributylamrnonium perchlorate + 0.3 M tributylamine. The diffusion coefficients of U(VI) and U(VI)- U(V) binuclear complex determined by chronoamperometric measurement are 8.8 cm s and 5.37 10 cm s respectively
Journal of Sciences, Islamic Republic of Iran
University of Tehran
1016-1104
8
v.
3
no.
1997
https://jsciences.ut.ac.ir/article_31250_4faf9da37077eb035bc9b26042482069.pdf
AROMATIZATION OF HANTZSCH 1,4-
DIHYDROPYRIDINES WITH ZINC
CHLOROCHROMATE NONAHYDRATE
text
article
1997
eng
Hantzsch 1 ,4- dihy&opyridines are rapidly oxidized to the corresponding pyridine
derivatives using zinc chlorochromate nonahydrate [Zn(C1CrO ) .9H O] in
dichloromethane at room temperature. In addition to aromatization, no loss of the 4-
substituent is observed
Journal of Sciences, Islamic Republic of Iran
University of Tehran
1016-1104
8
v.
3
no.
1997
https://jsciences.ut.ac.ir/article_31251_b4b835f5f1b3b61ead46c1e56c9c1c93.pdf
REGIOSPECIFIC SYNTHESIS OF 1,6-
DIMETHY L-9,lO-ANTHRACENEDIONE
text
article
1997
eng
Treatment of acetyl- 1,4-benzoquinone with isoprene gave the corresponding
regioselective adduct (I). Rearrangement of the adduct (1) in pyridine and
methanol gave 2-acetyl-5, 8-dihydro-6-methyl- 1,4-dihydroxynaphthalene (2).
Silver oxide oxidation of the rearranged product (2) gave 2-acetyl-5,8-dihydro-
6-methyl- 1,4naphthalenedione (3). Regioselective addition of trans-piperylene
to this compound (3) gave the c&esponding adduct (4). Treatment of the
resulting cycloadduct (4) with manganese dioxide gave the regiospecific 1,6-
dimethyl-9, 10-anthracenedione (5). Each of the foregoing reactions proceeds in
high yield
Journal of Sciences, Islamic Republic of Iran
University of Tehran
1016-1104
8
v.
3
no.
1997
https://jsciences.ut.ac.ir/article_31252_63ff1be82cae7709c98cda1cdcb6a90a.pdf
ALKALOIDS OF PAPAVERACEAE (XVI) [I].
ALKALOIDS OF PAPAVER FUGAX
POPULATION TAROM
text
article
1997
eng
Papaverfugax Poiret population Tarom was shown to contain one major alkaloid,
mecamberine (0.4%), and six minor alkaloids, roemerine, pronuciferine, protopine,
thebaine, nornuciferine and salutaridine. Nornuciferine was detected for the first time
in P. fugax
Journal of Sciences, Islamic Republic of Iran
University of Tehran
1016-1104
8
v.
3
no.
1997
https://jsciences.ut.ac.ir/article_31253_c94f96a5f6a55b858ab83d349f279334.pdf
THE ACTIVATION OF CARBON DIOXIDE AT A
MAGNESIUM (1 00) SURFACE
THE ROLE OF OXYGEN TRANSIENTS
text
article
1997
eng
X-ray photoelectron and high resolution electron energy loss spectroscopic
(XPS-HREELS) studies have shown that the adsorption of carbon dioxide at
Mg(100) surfaces at 80K is followed by a dissociative reaction leading to the
formation of a metastable surface carbonate above 80K. The formation of a
carbonate species is proposed to proceed through oxidation of C0 (g) by an
active oxygen surface transient O formed by dissociation of dioxygen or
dissociative chemisorption of carbon dioxide. The O(1s) data establish that oxidation
and carbonate formation occur simultaneously suggesting that dissociative
chemisorption involves the formation of an oxygen adatom which can
either form oxide or react with C0 to form carbonate
Journal of Sciences, Islamic Republic of Iran
University of Tehran
1016-1104
8
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3
no.
1997
https://jsciences.ut.ac.ir/article_31254_098b846e6e9a0730aaaf7526051f2c11.pdf
SYNGENETIC STRONTIUM ORE DEPOSITION
AT THE BASE OF ASMARI FORMATION,
BANGESTAN ANTICLINE, BEHBAHAN, IRAN
text
article
1997
eng
Detailed petrographic, geochemical and strontium isotope studies, combined with
field observation and rnicrofacies investigations indicate that syngenetic celestite at
the base of Asmari Formation at the Bangestan anticline, Behbahan region, was
deposited directly from Tertiary seawater in an intrasupratidal to supratidal
environment. During diagenesis, the precipitated celestite underwent several textural
and mineralogical modifications, the most important of which was the formation of
diagenetic crystallization rhythmites. Fluid inclusion geotherrnometry and rmR
analyses suggest that the fluid medium, in which recrystallization of the celestite took
place, was among other constituents rich in immature hydrocarbons. It is demonstrated that the celestite concretions were subjected to several low temperature thermal events, the maximum of which did not exceed 255?C
Journal of Sciences, Islamic Republic of Iran
University of Tehran
1016-1104
8
v.
3
no.
1997
https://jsciences.ut.ac.ir/article_31255_b2209d6e9274b5e791580c45037c0905.pdf
THE PC-TAU METHOD ON THE SOLUTION OF
A MODEL OF AN ISOLATED COSMIC STRING
text
article
1997
eng
In this paper, we adapt the operational Tau Method for personal computers
and apply it to a system of two nonlinear second order ordinary differential
equations which are related to general relativity. The interesting behaviour this
problem exhibits in its numerical treatment is discussed. In this problem, we try
to use the Tau perturbation term to locate the correct solution of this nonlinear
problem. The results of this experiment and those which are going to be given
in another paper show that in some problems the effect of nonlinearity could
prevent the correct solution from being located properly
Journal of Sciences, Islamic Republic of Iran
University of Tehran
1016-1104
8
v.
3
no.
1997
https://jsciences.ut.ac.ir/article_31256_d714d599c2c8a5a31918b2326233d014.pdf
INITIAL RAMIFICATION INDEX OF
NONINVARIANT VALUATIONS ON FINITE
DIMENSIONAL DIVISION ALGEBRAS
text
article
1997
eng
Let D be a division ring with centre K and dim, D< ? a valuation on K and v a
noninvariant extension of ? to D. We define the initial ramfication index of v over
?, ?(v/ ?) .Let A be a valuation ring of o with maximal ideal m, and v , v ,…, v noninvariant extensions of w to D with valuation rings A , A ,…, A .
If B= A , it is shown that the following conditions are equivalent: (i) B is a finite A-module, (ii) B is a free A-module, (iii) [B/mB: A/m] = [D: k], (iv) e(v / ?) f(v / ?)= [D: K] and ? (v / ?)= e(v / ?). It is also proved that if ? (v/ ?) = e(v/ ?), and any of (i) - (iv) holds, then v is invariant
Journal of Sciences, Islamic Republic of Iran
University of Tehran
1016-1104
8
v.
3
no.
1997
https://jsciences.ut.ac.ir/article_31257_15f75ef1d10234576e559849154d710f.pdf
HIGH LATITUDE GAMMA RAYS
ASSOCIATED WITH VIRGO
text
article
1997
eng
A more detailed analysis is made of the energy spectrum of the diffuse component
of extragalactic gamma rays over the range of 0.3- 10 GeV, obtained fromthe EGRET
instrument at the Compton Gamma Ray Observatory. The derived excess energy
spectrum of high galactic latitude, b > 60°, using intercept method shows that it is
correlated with Virgo cluster (over lsr) and average Virgo intensity is about 20 percent of total diffuse extra galactic intensity. The Virgo predicted models seem to be overestimated
Journal of Sciences, Islamic Republic of Iran
University of Tehran
1016-1104
8
v.
3
no.
1997
https://jsciences.ut.ac.ir/article_31258_9633a4a76c2f86667c0aed8e8f61a9d8.pdf
DESIGN OF A SIMPLE LASER SYSTEM FOR
NEPHELOMETRIC DETERMINATION OF
ANIONS
text
article
1997
eng
A simple analytical system suitable for nephelometric measurements is introduced
in this article. The electronic and optical components are simplified so that the
apparatus is easily assembled from materials that are generally available. This
instrument is designed for the efficient measurement of anions, and microgram
quantities of ions may be determined by a convenient method of titration. Using this
systarn, the ion detection is performed on several species, and the preliminary results
are reported here. The results from the determination of sulfate and chloride ions show a good detection limit(10 M), and a linearity range of 10 -10 M
Journal of Sciences, Islamic Republic of Iran
University of Tehran
1016-1104
8
v.
3
no.
1997
https://jsciences.ut.ac.ir/article_31259_f449b35761ae503aca167a5eb48d1e9c.pdf