EXPERIMENTAL RESEARCH ON DETERMINATION OF DEFORMATIONS IN THE CUTTING PROCESS IN WET SANDY SOILS

The active parts of tillage equipment must be checked for wear resistance, under different conditions working with the soil, so that the average life span should be determined wear resistance, to ensure timely changes of parts. Research in the field has shown that there are at least two main forces acting on the active parts: impact and friction, the action of these forces causes wear. In order to test the tillage knives in laboratory conditions, was used a stand made by INMA Bucharest. With the help of this stand, the deformations in the cutting process were determined in different working conditions: at a certain working speed and at a certain humidity of the sandy soil

On the number of solutions of a transcendental equation arising in the theory of gravitational lensing

The equation in the title describes the number of bright images of a point source under lensing by an elliptic object with isothermal density. We prove that this equation has at most 6 solutions. Any number of solutions from 1 to 6 can actually occur.Comment: 26 pages, 12 figure

ASPECTS REGARDING THE PRESERVATION OF FOOD PRODUCTS USING HIGH VOLTAGE PULSED ELECTRIC FIELD

Food preservation is an important link in ensuring their quality. The ways in which this desideratum is achieved include a wide range of conservation, thermal and athermal techniques. The paper presents aspects regarding the preservation of food products using the high voltage pulsed electric field, as well as the current stage of the realization of technical equipment that uses this technology

Metformin plus PIAF combination chemotherapy for hepatocellular carcinoma

Objectives: Metformin, the most used oral antidiabetic drug for the treatment of type 2 diabetus mellitus, has proved encouraging results when used in the treatment of various types of cancer such as triple-negative breast cancer. Despite compelling evidence of a role of metformin as an anticancer drug, the mechanisms by which metformin exerts its oncostatic actions are not fully understood yet. Therefore, we tried to bring new insights by analyzing the anti-neoplastic effect of metformin for hepatocellular carcinoma-derived stem-like cells treated with conventional combination chemotherapy. Methods: Cancer stem-like cells previusly isolated from a hepatocellular carcinoma biopsy were treated with metformin, PIAF chemotherapy regimen and the combination of these two protocols. Measurements of lipid peroxidation, reduced glutathione, fluorescein diacetate and proliferation rates were determined, apart from the autophagy assay and apoptosis determination by chip flow cytometry. Results: Metformin alone and especially metformin in association with PIAF increases oxidative stress within the cells by increasing the levels of lipid peroxids as well as decreasing the levels of reduced glutathione. The MTT cell proliferation assay showed decreased prolife­ration rates for the arm treated with metformin and with the combination of drugs in comparison with the control arm, proving high correlation with the oxidative stress results. The autophagy assay and determination of apoptosis by chip flow cytometry confirmed the results obtained in the previous assays. Conclusion: Metformin could be used in chemotherapy treatments to induce reactive oxygen species and increase the cytostatics effects within the tumor cell. Still, further experiments must be carried out on murine models before we can move on and use this drugs in the adjuvant setting for unresectable primary liver cancer

CONSIDERATIONS ON THE IMPORTANCE OF CULTIVATING SORGHUM TO THE BIOFUEL INDUSTRY FOR PRODUCING BIOETHANOL

Energy crops are crops suitable for the production of products such as biofuels (biodiesel, ecological diesel) and electric or thermal energy. Plants suitable for such energy crops are: woody (energy willow, poplar, paulownia) and grasses (annual crops such as corn, wheat, rapeseed, soybeans, sweet sorghum or perennials: pampas grass, elephant grass). The article presents a series of arguments for growing sugar sorghum on large areas in order to obtain the bioethanol used in the biofuel industry

Finite difference lattice Boltzmann model with flux limiters for liquid-vapor systems

In this paper we apply a finite difference lattice Boltzmann model to study the phase separation in a two-dimensional liquid-vapor system. Spurious numerical effects in macroscopic equations are discussed and an appropriate numerical scheme involving flux limiter techniques is proposed to minimize them and guarantee a better numerical stability at very low viscosity. The phase separation kinetics is investigated and we find evidence of two different growth regimes depending on the value of the fluid viscosity as well as on the liquid-vapor ratio.Comment: 10 pages, 10 figures, to be published in Phys. Rev.

CONSIDERATIONS ON ENERGETIC CROPS POTENTIAL

In order to breathe fresh and clean air, nature and terrestrial atmosphere should be preserved and protected. Carbon emissions represent one of the main enemies of air quality. Recently, carbon emissions have surpassed all the predictions because the excessive industrialization, becoming the determining factor for global warming. A viable alternative to carbon emissions reduction is the utilization of energy sources that can diminish the noxious substances emissions up to zero. This can be done by using the power of wind, sun, water, energy plants, etc. Among the energetic potential plants, the biomass is obtained- a form of renewable energy which final product is biofuel

THE DISEASES AND PESTS CONTROL IN THE FARMING CULTURES, USING BIOPRODUCTS

The making of a performant agriculture is influenced among other things by the applicative working technologies, the phyto-sanitary protection having an important role within these technologies.The current research and studies concerning the methods and equipments of applying of phyto-sanitary treatments, are enrolled in the new trends for applying a long lasting agriculture; the phyto-sanitary protection represents one of the main sources of the environment poluation resources.In the first part of the work is presented a syntesis of the aspects concerning the impact of the phytosanitary treatments used in agriculture upon environment, the methods used these days for diseases and pests control and the future  trends  with referrence to the technologies and products used in  the agricultural ecological practice and at the end are presented products already used or being at the begining using phase