University of Tehran
Journal of Sciences, Islamic Republic of Iran
1016-1104
8
2
1997
06
01
STUDY OF ONTOGENETIC CHANGES IN
CROCUS SATZVUS L. BY STUDY OF PHENOLICS
AND PHENOL OXIDASES IN THE CORM AND
BUD TISSUES
-
31419
EN
Journal Article
1970
01
01
Investigation into total phenolics and their spectrum in the buds and corms of
saffron Crocus and a study of polyphenol oxidase changes in the apical bud during
different stages of growth and development showed that changes in the growth and
development of the apical bud may be related to changes in the composition of
phenolics in the corm. A sudden intense change in content and kind of phenolic
components probably acts as a switch.This change shifts the balance between
endogenous growth promoters and growth inhibitors so that bud growth is resumed
and certain developmental changes in the bud are triggered
https://jsciences.ut.ac.ir/article_31419_8348a341725fe60d05d954c09828bea9.pdf
University of Tehran
Journal of Sciences, Islamic Republic of Iran
1016-1104
8
2
1997
06
01
IN VITRO ANTAGONISTIC EFFECTS OF
TRICHODERMA SPP. ON SEVERAL SOILBORNE
PLANT PATHOGENIC FUNGI
-
31420
EN
Journal Article
1970
01
01
In vitro studies with Trichoderma spp., soil-borne fungal antagonists, demonstrated
that a number of isolates produced volatile and non-volatile metabolites
capable of inhibiting the growth and sporulation of several soil-borne plant
pathogenic fungi. Microscopic observations showed that T. harzianm and T.
viride, isolated from soil samples from Ahwaz and Karaj, adversely affected the
mycelial growth of Rhizoctonia solani, the causal agent of seed, root rot and
damping-off of bean, by hyphal contact, coiling, penetration, necrosis, lysis and
in some cases fraginentation of the pathogen hyphae. T. harzianum hyphae
grew parallel to those of Phytophthora drechsleri, the causal agent of root rot of
cucumber, and produced appendages that attached themselves to P. drechsleri
hyphae. Isolates of T. harzianum from Ahwaz and T. viride from Shahriar ,
Karaj, significantly reduced the germination of pseudosclerotia of
Colletotrichum coccodes, the causal agent of brown stem, root rot and black dot
of potato. The Ahwaz isolate of T. harzianum inhibited mycelial growth and
germination of Phytophthora erythroseptica, the causal agent of pink rot of
potato tubers, without penetrating the pathogen hyphae. Trichoderma spp. also
reduced the mycelial growth and spore germination of Fusarium solani, the
causal agent of black root rot of chickpea
https://jsciences.ut.ac.ir/article_31420_9d30a12d04c368cc50e15d7c1b1365d4.pdf
University of Tehran
Journal of Sciences, Islamic Republic of Iran
1016-1104
8
2
1997
06
01
KINETIC-SPECTROPHOTOMETRIC
DETERMINATION OF TRACE AMOUNTS OF
NITRITE BY THE REACTION OF METHYL
ORANGE FORMATION
-
31421
EN
Journal Article
1970
01
01
The composite diazotization coupling reaction of sulfanilic acid and N, Ndimethylaniline
was used for the precise, accurate, and rapid determination of trace
amounts of nitrite ion (0.02-3 µg/ml). The reaction was monitored
spectrophotometrically by measuring the absorbance of the produced methyl orange
at 510 nm by a fixed the method of 5.0 minutes. The relative standard deviation for
the determination of 0.50 µg/ml of nitrite was 1.8% (n=l 1). The method was used for
the determination of nitrite in sausage and water samples
https://jsciences.ut.ac.ir/article_31421_7e3ea639e41cda592530d05ce2a64f3f.pdf
University of Tehran
Journal of Sciences, Islamic Republic of Iran
1016-1104
8
2
1997
06
01
SELECTIVE TRANSPORT AND EXTRACTION OF
ALKALI METAL CATIONS (Na & K ) THROUGH
CHLOROFORM LIQUID MEMBRANE BY
DIETHYLENE GLYCOL MONOBUTYL ETHER
AND DIETHYLENE GLYCOL DIBUTYL ETHER
-
31422
EN
Journal Article
1970
01
01
A liquid membrane containing diethylene glycol monobutyl ether (2) shows
specificity for K ion in transport while diethylene glycol dibutyl ether (1) was
selective for Na over K . As an extractant, ligand 2 exhibited pronounced extraction
selectivity for K over Na in comparison with ligand 1
https://jsciences.ut.ac.ir/article_31422_a7e15fd0ca9eadb34c3c9427c402db9e.pdf
University of Tehran
Journal of Sciences, Islamic Republic of Iran
1016-1104
8
2
1997
06
01
ALKALOIDS OF PAPAVERACEAE (XV) [ 11.
ALKALOIDS OF PAPAVER PSE UDO-ORIENTALE
POPULATION TAROM
-
31423
EN
Journal Article
1970
01
01
Papaver pseudo-orientale population Tarom was shown to contain two major
alkaloids, isothebaine (0.65%), Orientalidine (0.15%) and four minor alkaloids,
bracteoline, mecambridine, Or and a novel alkaloid, nor-methyl Or .
https://jsciences.ut.ac.ir/article_31423_75789ce7a6a79900a9ba30bf9892717f.pdf
University of Tehran
Journal of Sciences, Islamic Republic of Iran
1016-1104
8
2
1997
06
01
MODIFIED NUMERICAL TABLES FOR THE
CALCULATION OF NON-SPHERICAL
CONTRIBUTION TO SECOND VIRIAL
COEFFICIENTS AND THE CORRELATION
EQUATIONS OF STATE FOR CO,, CS, AND C6H6
-
31424
EN
Journal Article
1970
01
01
A revised analysis of the effect of long-range nonspherical terms in the
intermolecular potential on the second virial coefficient is presented with a
preferred Hartree-Fock-Dispersion functional (HFD-C) spherical core treatment
of the integrations for small intermolecular distances. A set of modified numerical
tables for the accurate calculation of the nonspherical contribution to the
second virial coefficients is presented and a new correlation equation of B~O
for C02, CS2 and C6H6 is reported
https://jsciences.ut.ac.ir/article_31424_4e08631e5b7a344670977ff087cae6c4.pdf
University of Tehran
Journal of Sciences, Islamic Republic of Iran
1016-1104
8
2
1997
06
01
KUSHK ZINC-LEAD DEPOSIT
A TYPICAL BLACK-SHALE-HOSTED DEPOSIT
IN YAZD STATE, IRAN
-
31425
EN
Journal Article
1970
01
01
Kushk zinc- lead deposit is located about 167 km east of the city of Yazd, Iran. The
geographical location of the mine is 31°, 40' N and 55", 40' E. Different rock types
including volcanics and subvolcanics (rhyolites, rhyodacites, dacites, and rhyolitic
tuffs) and sedimentary rocks (shale, limestones and dolomites) crop out in the area.
Mineralization of the deposit occurs in black shale of the late Precambrian time. The
paragenetic sequence of the minerals indicates two stages of mineralization for lead
minerals (galena) and one stage for zinc minerals (sphalerite). The Kushk deposit
bears several similarities to the base metal deposits related to submarine volcanisms
and sedimentation. The deposit is hosted by black shale and is proposed to be similar
to the Rarnrnelsberg (Germany) and Sullivan (British Colombia, Canada) deposits.
The Kushk deposit is believed to be associated with the evolution of Protrozoic
continental rifting in Iran and the mineralization in this deposit passes gradually
outward into an iron rich sulfide zone which is the case in Sullivan-type deposits
https://jsciences.ut.ac.ir/article_31425_ea68810bba02b7d122dca107a41c24fb.pdf
University of Tehran
Journal of Sciences, Islamic Republic of Iran
1016-1104
8
2
1997
06
01
A STUDY OF OPTIMAL DIMENSIONING OF
QUEUES WITH RESPECT TO SOCIAL AND
INDIVIDUAL PROFIT
-
31426
EN
Journal Article
1970
01
01
In this paper, a system of GIG/l/K queue is considered. The optimal
system's capacity (K), when the system is optimized with respect to the benefit
of the entire system (social optimization) and when the criterion for optimality
is individual gains (individual optimization), is determined and compared. In
social optimization, the system capacity is obtained through maximization of
the system's profit. However, when individual gains is the criteria, the system
capacity is determined as a result of customers not joining the system because
they estimate that getting service from the system does not yield them any
profit and therefore leave the system. It is shown by simulation that irrespective
of the traffic intensity, p and arrival and service time distributions with
different failure and acceleration rates, the K obtained from social optimization
of the system is always equal or less than the K obtained from individual
optimization. Thus, the social optimization of the system not only maximizes
the system's profit but also preserves individual gains and prevents the
customer from leaving the system. In this paper, some other interesting results
are also reported.
https://jsciences.ut.ac.ir/article_31426_9b2291df163fcc43fd8b8795223d1760.pdf
University of Tehran
Journal of Sciences, Islamic Republic of Iran
1016-1104
8
2
1997
06
01
A B INITIO CALCULATION OF THE KC1 PHONON
FREQUENCIES
-
31427
EN
Journal Article
1970
01
01
We have calculated the phonon frequencies of KC1 along symmetry directions
using an approach which is a combination of the frozen phonon and force constants
methods. We also calculated Griineisen parameters for all modes at X and L points
in the Brillouin zone. Finally, the slope of acoustic dispersion curves around zone
center were used to calculate the three independent elastic coefficients c11, c44,c12 as
well as the Bulk modulus. Our ab initio calculations are based on pseudopotential
density functional theory within the local density approximation
https://jsciences.ut.ac.ir/article_31427_427ecbe873932fa61c97e401ef18039c.pdf