2024-03-29T01:44:56Z
https://jsciences.ut.ac.ir/?_action=export&rf=summon&issue=3953
Journal of Sciences, Islamic Republic of Iran
J.Sci.I.R.I
1016-1104
1016-1104
1995
6
1
PROBING THE ACTIVE SITE OF RHODANESE
WITH DISULFIDE REAGENTS
1995
03
01
https://jsciences.ut.ac.ir/article_31210_1366d5070cec732bd231e121193b6431.pdf
Journal of Sciences, Islamic Republic of Iran
J.Sci.I.R.I
1016-1104
1016-1104
1995
6
1
LIFE HISTORY, BEHAVIOR AND
MORPHOLOGY OF THE IMMATURE STAGES
OF ENOCHRUS QUADRIPUNCTATUS HERBST
IN THE LABORATORY
(COLEOPTERA: HYDROPHILIDAE)
I- LIFE HISTORY AND BEHAVIOR
The life history of Enochrus quadripunctatus Herbst was studied in the
laboratory. The duration of each developmental stage, larval behavior, and preimaginal
mortality rate were determined. It takes the insect a total of 43 days
from hatching to reach the adult stage, with a high mortality rate in the first
stadium. The mortality rate decreases as the beetle passes through the immature
stages. Although the species is basically similar to the other hydrophilids
studied thus far, some differences with those reared in the laboratory, such as
time of each developmental stage, larval behavior, and mortality rate have been
observed.
1995
03
01
https://jsciences.ut.ac.ir/article_31211_f097122d4efca8d13cebceaec79827b2.pdf
Journal of Sciences, Islamic Republic of Iran
J.Sci.I.R.I
1016-1104
1016-1104
1995
6
1
PARTIAL PURIFICATION AND
CHARACTERIZATION OF
B-GALACTOSIDASE FROM
ASPERGILLUS NIGER UV-5
The enzyme pgalactosidase from a mutant strain of A. niger UV-5 was
partially purified using ammonium sulfate and acetone. The saturation range of
60-80% ammonium sulfate was found to yield 60.5% enzyme recovery with 2.4
fold purification. Acetone precipitation at enzyme: acetone ratio of 1 : 1.5
brought about a higher yield i.e. 68% and three-fold purification. The combined
procedures of 1.5 volume solvent fractionation followed by 50% ammonium
sulfate precipitation brought about 8-fold purification with 40% enzyme yield.
The optimum temperature of the enzyme was 65°C and the optimum pH was 4-
5. The pgalactosidase was strongly inhibited by galactose. Comparative study
of partially purified P-galactosidase in the present study with a commercial
lactase from A. oryzae revealed comparable results
1995
03
01
https://jsciences.ut.ac.ir/article_31212_2362d1d6b3185025be48dd7713be5376.pdf
Journal of Sciences, Islamic Republic of Iran
J.Sci.I.R.I
1016-1104
1016-1104
1995
6
1
SYNTHESIS OF 8-HYDROXY-6-METHOXY-
3-UNDECYLISOCOUMARIN AND 2-HY DROXY -
4-METHOXY-6-(2-OXOTRIDECYL) BENZOIC
ACID
Straightforward conversion of (+)-6,8-dimethoxy-3,4-dihydro-3-
undecylisocoumarin (3) to the title isocoumarin was carried out. Hydrolytic ring
opening of (3) afforded the hydroxy acid (4) which was immediately oxidized
to keto acid (5) using chromic acid, Cyclodehydration of (5) afforded the 6,8-
dimethoxy-3-undecylisocoumarin (6) which on selective demethylation of 8-
methoxy group furnished the title isocoumarin (2). The title keto acid (1, R=H)
which was obtained by hydrolytic ring opening of title isocoumarin (2) was
esterified to keto ester (1, R=Me)
1995
03
01
https://jsciences.ut.ac.ir/article_31213_786ae802bbbac3ffba2729b43864c8d7.pdf
Journal of Sciences, Islamic Republic of Iran
J.Sci.I.R.I
1016-1104
1016-1104
1995
6
1
NITROIMIDAZOLES XI [I]. SYNTHESES OF
DISUBSTITUTED
NITROIMIDAZOLYLQUINOLINES
Reaction of substituted-aniline (8) with ethyl (l-methyl-5-nitroimidazole-2-
carbonyl) acetate (9) gave 4-hydroxy-2-(l-methyl-5-nitro-2-imidazolyl)-
substituted-quinolines (lo), which were converted to compound 11 with
phosphorus oxychloride. Substituted-2-(l-methyl-5-nitro-2-imidazo1yl)-4.-
methyl-(or phenyl-) quinolines (14) were prepared through the reaction of 2-
acetyl-5-nitro-1-methyl-imidazole (13) with 0-aminoacetophenones (or Oaminobenzophenones)
in acid medium
1995
03
01
https://jsciences.ut.ac.ir/article_31214_0a680a6106e6ebc4895e6d68a4826418.pdf
Journal of Sciences, Islamic Republic of Iran
J.Sci.I.R.I
1016-1104
1016-1104
1995
6
1
ON THE VISCOSITY OF NATURAL GAS
The existing measuremenJs of the viscosity of gaseous systems can be
extended if use is made of statistical mechanics. In this work, we confine
ourselves to the measurements of the viscosity of multicomponent mixtures of
low-density gases. The method is applied to one sample of natural gas.
1995
03
01
https://jsciences.ut.ac.ir/article_31215_997a0d45773428650b74a7fb8c902ca9.pdf
Journal of Sciences, Islamic Republic of Iran
J.Sci.I.R.I
1016-1104
1016-1104
1995
6
1
KINETICS AND MECHANISM OF AERIAL
OXIDATION OF HYDROQUINONE IN A
DEVELOPER SOLUTION AND
DETERMINATION OF DEVELOPER'S
HALF-LIFE AT 20°C
The aerial oxidation of hydroquinone in a freshly prepared developer solution
at 20°C has been studied through the measurement of concentration changes by a
spectrophotometric method. The concentration of consumed hydroquinone is
directly proportional to time, and the equation tIl2 = C, / 0.0786 was obtained to
calculate the half-life of the developer. In this equation, the half-life is in hours
and the initial concentration of hydroquinone, C,, is in g/l. The following
mechanism for the reaction has also been proposed
1995
03
01
https://jsciences.ut.ac.ir/article_31216_17b12d05f9a917f40fc5009e0d35e2d6.pdf
Journal of Sciences, Islamic Republic of Iran
J.Sci.I.R.I
1016-1104
1016-1104
1995
6
1
AN ACCURATE SOLUTION FOR THE TWODIMENSIONAL
MODEL OF ALBITE USING
STATISTICAL MECHANICS
A two-dimensional model of Al, Si ordering in alkali feldspar is formulated
and used to calcul~tea ccurately the configurational entropy for the model. For
this purpose, a new method called Independent Basic Unit or IBU is introduced.
To compare the results with the exact values, this method is applied to the onedimensional
model of albite. The results given by IBU are found to be accurate
to the extent that the deviation in free energy is less than 0.8%. The reduced
configurational entropy is calculated to 'be 1.065 corresponding to 8.854 J K-1
mol-1 for the two-dimensional model. This value is within 6% of standard
values obtained by using approximate calculations for the same model
1995
03
01
https://jsciences.ut.ac.ir/article_31217_6e57bef2b91d02a2b396973fe5cdcefa.pdf
Journal of Sciences, Islamic Republic of Iran
J.Sci.I.R.I
1016-1104
1016-1104
1995
6
1
A NORM INEQUALITY FOR CHEBYSHEV
CENTRES
In this paper, we study the Chebyshev centres of bounded subsets of normed
spaces and obtain a norm inequality for relative centres. In particular, we prove
that if T is a remotal subset of an inner product space H, and F is a star-shaped
set at a relative Chebyshev centre c of T with respect to F, then llx - qT (x)1I2 2
Ilx-cll2 + Ilc-qT (c) 112 x E F, where qT : F + T is any choice function sending x
to the point qT (x) with Ilx - qT (x)11= SUPfeT Ilx - dl (note that T is called remotal
if such a choice function qT exists). We then use such an inequality to show
that, under some restrictions, a uniquely remotal set is a singleton. Further, we
show that if c is a centre of a remotal subset T of a norrned space E and x E E,
then there exists a. functional f E E* such that I I f I1 I 1 and Ilx - qT (x)1I2 L
I I c - q*(c)112 + 2 If (X - C) 12 - IIx - ~11
1995
03
01
https://jsciences.ut.ac.ir/article_31218_0e03acbeecb266b728185f8d17a4a135.pdf
Journal of Sciences, Islamic Republic of Iran
J.Sci.I.R.I
1016-1104
1016-1104
1995
6
1
A STUDY OF ULTRASONIC ABSORPTION OF
SOME AMINO ACIDS AND THEIR MIXTURES
AT PHYSIOLOGICAL pH
In this paper, the ultrasonic absorption of amino acids was measured using a
small cylindrical resonator at physiological pH and 25°C and a concentration of
0.1. M. The absorption of mixtures of some amino acids was also measured. In
the case of cysteine-histidine, the absorption of mixtures is much larger (more
than twice) than the summation of absorption of the individual amino acid. This
may be due to the weak bonds between the side chain of histidine and the SH
group of cysteine molecules. As for the absorption of proteins, it could also be
due to weak bonds mentioned earlier
1995
03
01
https://jsciences.ut.ac.ir/article_31219_a1026bb34bb54768a831e5fdb403f77c.pdf