in this study the effect of different nitrogen source substrates on the amount of chitosan production by aspergillus niger was investigated. a. niger ptcc 5012 from the persian type culture collection (ptcc) was grown on soy bean, corn seed and canola residues at 30 °c for specified cultivation days under sterilized conditions. chitosan was extracted from the fungal mycelia using hot alkaline a...

For the first time, a multi-residue methodfor simultaneous determination of 41LC-amenable pesticides in rice, belonging to different chemical classes has been developed in Iran by LC-MS/MS. The pesticides were analyzed simultaneously in a single run using positive electrospray ionization with multiple reaction monitoring (MRM) after extraction with slightly modified QuEChERS method. The calibra...

The toric residue is a map depending on n + 1 semi-ample divisors on a complete toric variety of dimension n . It appears in a variety of contexts such as sparse polynomial systems, mirror symmetry, and GKZ hypergeometric functions. In this paper we investigate the problem of finding an explicit element whose toric residue is equal to one. Such an element is shown to exist if and only if the as...

It is shown that the extended quadratic residue code of length 20 over GF(7) is a unique self-dual [20, 10, 9] code C such that the lattice obtained from C by Construction A is isomorphic to the 20-dimensional unimodular lattice D 20, up to equivalence. This is done by converting the classification of such self-dual codes to that of skew-Hadamard matrices of order 20.

The largest minimum weight of a self-dual doubly-even binary (n, k, d) code is d = 4bn/24c+ 4. Of such codes with length divisible by 24, the Golay Code is the only (24, 12, 8) code, the Extended Quadratic Residue Code is the only known (48, 24, 12) code, and there is no known (72, 36, 16) code. One may partition the search for a (48, 24, 12) self-dual doubly-even code into 3 cases. A previous ...

In current study, the effects of Iranian rice cooking method (Kateh) on residue levels of 41 pesticides were investigated. The pesticides were selected according to Iranian National Standards Organization (INSO) regulations and covered 18 permitted and 23 banned pesticides belonging to different chemical classes such as organophosphate, triazole, and carbamate. A 250 g portion of rice sample wa...

This paper reviews recently published multi-residue chromatographic methods for the determination of steroid hormones in edible matrices. After a brief introduction on steroid hormones and their use in animal fattening, the most relevant EU legislation regarding the residue control of these substances is presented. An overview of multi-residue analytical methods, covering sample extraction and ...

The toric residue is a map depending on n + 1 divisors on a complete toric variety of dimension n . It appears in a variety of contexts such as sparse polynomial systems, mirror symmetry, and GKZ hypergeometric functions. In this paper we investigate the problem of finding an explicit element whose toric residue is equal to one. Such an element is shown to exist if and only if the associated po...