Let A = K[x1, . . . , xn] denote the polynomial ring in n variables over a field K. We will classify all the Gotzmann ideals of A with at most n generators. In addition, we will study Hilbert functions H for which all homogeneous ideals of A with the Hilbert function H have the same graded Betti numbers. These Hilbert functions will be called inflexible Hilbert functions. We introduce the notio...

microalloyed cast steels are a group of microalloyed steels in which reliable mechanical properties could be achieved by heat treatment. in this work, the heat treatment processes were carried out on the cast specimens as the step samples by different thicknesses and zr content. the results show that after homogenization, variations in thickness have no effect on the hardness. also, after hea...

The Hilbert transform plays an important role in the theory and practice of signal processing. A generalization of the Hilbert transform, the fractional Hilbert transform, was recently proposed, and it presents physical interpretation in the definition. In this paper, we develop the discrete fractional Hilbert transform, and apply the proposed discrete fractional Hilbert transform to the edge d...

in this paper we develop a natural generalization of schauder basis theory, we term operator-valued basis or simply ov-basis theory, using operator-algebraic methods. we prove several results for ov-basis concerning duality, orthogonality, biorthogonality and minimality. we prove that the operators of a dual ov-basis are continuous. we also dene the concepts of bessel, hilbert ov-basis and obt...

Let C denote the category of Hilbert modules which are similar to contractive Hilbert modules. It is proved that if H0, H ∈ C and if H1 is similar to an isometric Hilbert module, then the sequence 0 → H0 → H → H1 → 0 splits. Thus the isometric Hilbert modules are projective in C. It follows that ExtC (K, H) = 0, whenever n > 1, for H, K ∈ C. In addition, it is proved that (Hilbert modules simil...

ni-hard4 white cast iron is excellent wear resistant material and has been widely used in wearaffected equipment operated under extreme conditions, such as in mineral processing, cement, copper and iron manufacturing. in this study the effect of titanium addition (1.2, 0.7 and 0.2 wt.%) to the ni-hard 4 cast iron with the nominal composition of si= 1.5%, mn=0.5%, c=3%, p=0.05%, s= 0.05%, mo= 0....

honing is a process for finishing surfaces to obtain smooth surface. this process is used for finalpolish of inner parts such as engines cylinders. optimizing this process has always been a bigchallenge for mass production of cylinder blocks of internal combustion engines. honing processhas some variable parameters, thus to get their optimum rates the automobile cylinders were tested.in this re...