Volume 16 – Issue 2

In this paper, we show a method of pure metrics construction on a semiRiemannian 4-manifold of neutral signature with respect to Golden structures. As an illustration, by applying the method, we exhibit explicitly pure metrics on Walker 4-manifolds. Moreover, we present some examples for 4-dimensional Golden-Walker structures.

In this study, we dealt with the natural lift curves of the spherical indicatrices of a spacelike curve with null binormal.Furthermore, some interesting results about the original curve were obtained depending on the assumption that the natural lift curves should be the integral curve of the geodesic spray on the tangent bundle T(S^2_1) and T(Λ) .

In this paper we construct a new morphism of matrix coalgebras, than we prove that it is an epimorphism and also that its kernel is a coideal in the matrix coalgebra. Finally we give a generalization on this type of morphism between two matrix coalgebras.

In this paper, the some characteristic properties of ruled surfaces which are generated by the Darboux frame of the transversal intersection curve of two surfaces were given in 3-dimensional Euclidean space E^3. Also, the relations between the integral invariants of the closed ruled surfaces were showned. Finally, the examples for parametric-parametric and imlicit-implicit surfaces were given.

Using some new generalizations of Young’s inequality we apply a new refinement of Holder’s inequalities in order to give several new variants of Hardy-type inequalities following the method of Pachpatte.

The experimental study was focused on the effects of ultraviolet radiation in maize (Zea mays) at both cytogenetic and metabolic levels. Caryopses with uniform genophond were let to germinate in INCUCELL room in controlled environmental conditions before exposure to UV-C radiation for two different time durations. Biochemical investigation carried out by spectrophotometric method showed that photosynthesis pigments in seedling green tissue was lowered with 30%-40% denoting cell metabolism perturbation because of UV exposure during plant early ontogenetic stages. Several main types of chromosomal changes were highlighted in root meristem tissue – namely micronuclei and chromosomal aberrations: expelled and lagging chromosomes, inter-chromatin bridges – totalizing 4 to 4.5 % of total analyzed cells which suggested DNA injuries in developing plantlets.

This study is aimed at determining the drying speed of Myrtus communis L. by fluidization according to parameters of influence. It is based on exploiting the results of previous experimental studies, as well as the similarity between drying kinetic and chemical kinetic in order to establish a universal model. The considered parameters are: drying air temperature Tp, product absolute humidity Ns and drying air speed va.

This paper covers the design and construction of a system to provide support to decrease false assumptions in the detection of breast cancer. The main purpose of this work was to avoid the false assumptions in the detection process with cost effective manner. A model of decrease in false assumptions in breast cancer detection system was proposed with three modules: the first was pre-processing the mammogram image which was from removing the irrelevant parts, the second was formation of homogeneous blocks and that have done segmentation of the image and the third module was colour quantization that helped to break the colours among different regions. Our proposed system reduces the false assumptions during the detection of breast cancer.

A hip implant is used when the natural hip joint (consisting in the hip bone and the femur) is affected and no longer able to perform its function. One of the main problems that arise when an orthopaedic implant is used is the wear caused by the friction that occurs in the joint. As the wear decreases the lifetime of the implant, which makes it necessary to replace it, research on methods of reducing the wear occurring in the joint implant will continue until this necessity is eliminated and the patient’s locomotion can be performed as comfortably as possible. Therefore, the purpose of our work is to present the process of making and testing a hip implant joint prototype, where sliding friction is replaced by rolling friction, thereby reducing wear.