567 research outputs found

    Massive gravity from descent equations

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    Both massless and massive gravity are derived from descent equations (Wess-Zumino consistency conditions). The massive theory is a continuous deformation of the massless one.Comment: 8 pages, no figur

    MODERN METHODS FOR FOOD PRODUCTS PRESERVATION

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    Bacteria, molds and yeasts are microorganisms that play an essential role in spoiling food. Food products preservation technologies are intended to reduce the intensity of the activity of pathogenic microorganisms that generate decomposition processes. From the point of view of food technologies, heat treatments (pasteurization, sterilization) are the main way of preserving food. The trend is to minimize or replace heat treatments with nonthermal, non-destructive methods, in order to preserve the freshness, nutritional and bioactive value of the food products. This paper presents the working principles and the effects of various modern methods of preservation, thermal and athermal, on food

    STUDY ON THE CONVERSION OF A CONVENTIONAL TRACTOR INTO AN ELECTRIC TRACTOR

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    The paper presents the study on how a classic tractor with internal combustion engine can be modified so that it is powered by a battery-powered electric motor. The article presents equipment and components with which a tractor can be modified so that it can run on electricity. In general, an electric tractor consists of the chassis from which the heat engine, electric motor, battery, control and configuration equipment, software used and communication equipment, of the electronic systems on board the tractor are removed

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

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    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

    CONSIDERATIONS REGARDING THE IMPORTANCE OF THE SORTING OPERATION OF FRUITS AND VEGETABLES

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    For the normal development of daily activity and maintaining health, the body needs a certain amount of energy and complete nutritional factors (proteins, carbohydrates, lipids, vitamins, minerals, water). They are obtained from food, fruits and vegetables occupying a prominent place as a natural source of carbohydrates, alkalizing mineral salts, vitamins and water. Conditioning involves a set of operations aimed at bringing the products to the characteristics provided by standards, specific to a certain direction of capitalization. This article describes the operations included in the conditioning process, the role and importance of presorting and sorting fruits and vegetables, as well as equipment for these operations

    Will spin-relaxation times in molecular magnets permit quantum information processing?

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    Using X-band pulsed electron spin resonance, we report the intrinsic spin-lattice (T1T_1) and phase coherence (T2T_2) relaxation times in molecular nanomagnets for the first time. In Cr7M_7M heterometallic wheels, with MM = Ni and Mn, phase coherence relaxation is dominated by the coupling of the electron spin to protons within the molecule. In deuterated samples T2T_2 reaches 3 μ\mus at low temperatures, which is several orders of magnitude longer than the duration of spin manipulations, satisfying a prerequisite for the deployment of molecular nanomagnets in quantum information applications.Comment: 4 pages, 3 figures, in press at Physical Review Letter

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

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    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

    RESEARCH ON INDUSTRIALIZATION IN OBTAINING BIOFERTILIZERS AND BIOFUELS FROM SEAWEED

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    Obtaining biofertilizers and biofuels from organic products has been of great interest in recent years and is an important step in combating pests and reducing soil chemicals. Seaweed is an great agent in reduction pollution, in the textile industry, in the manufacture of pulp and paper, in distillation, in petrochemistry, metallurgy, chemistry, food, pharmaceuticals, as well as in agriculture as biofertilizers.This article presents stages of research worldwide on the potential of industrialization in obtaining biofuels and biofertilizers from seaweed.The paper highlights technologies and processing methods in obtaining future biofertilizers and biofuels with a low impact on new climate change felt strongly on agriculture
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