The study presents a model of the fruits reaction to impact, expressed in a differential equation built on the hypothesis that the fruits are rheological Kelvin – Voight bodies with a linear viscoelastic behavior. The differential equation was integrated using the Runge-Kutta method using a Turbo-Pascal application conceived by the authors. The force-time and force-strain curves have been determined for the impact. These curves simulate the real ones, obtained during experiments and from science literature and they are similar. Knowing these curves helps obtaining the characteristics of the impact, necessary to evaluate the damage degree of the apples and/or the functional and design parameters of the mechanical systems.

Braking process of a vehicle is complex, giving possibility to the driver to reduce car’s speed or to stop it at big speed in a short distance. Using the diagrams registered for different working conditions, defined accordingly with the experimental plan, there have been analyzed the values of deceleration, variation of speed and the covered space for each specified moment of braking. As a result of the experimental researches, we have reached the conclusion that a good behavior at cars braking is registered when the diagrams of deceleration variation in relation with braking time have a symmetric shape.

After the year 1990, the car park and also the number of drivers have almost tripled, being in a complete contradiction with the slow development of the infrastructure, leading to an increase in the percent of material and human damages as a result of traffic accidents. As far as Romania is concerned at the level of the European Union, during 2001-2010 recorded a 25% increase of the number of deceased persons, which places our country on the last but one place in the European top.

Surface waters are the main source of water consumption but at the same time, the majority waste waters are discharged in the surface water bodies. In order to highlight the evolution of environmental quality parameters and especially the evolution of this process and to achieve a set of procedures for improvement of some necessary steps to optimize the system of observation and action in time we propose this study. In the last three years a study has focused on the drawing of a rich map of data for the quality of surface water of the Danube River was developed and the main idea was to consider a great set of data and to organize them in a mathematical model in order to have an exhaustive image of the evolution of the water quality in time. Modelling this database using specific results which belong to numerical mathematical analysis was a desire of ours and the results can be used now in order to present an evolution, to make prediction and to consider the Danube River like a human entity which lives following mathematical rules that could be modelled.

This paper deals with a presentation of inclusion of modern teaching methods in master-level engineering education process at Engineering Faculty in Braila. This paper describes how the courses are laid out in order to achieve the desired goals and how the virtual laboratory experiments should fit into the courses to promote multidisciplinary and interdisciplinary understanding. A practical example of master degree studies will be provided as an example of good practices in supporting of National educational process to become harmonized with European Area of Higher Education.

Modelling the progress of air stream parameters in space and time as applied to a stock-breeding farm is a basis for implementing higher quality microclimate control, based on modern information technology, using powerful mathematical models. It permits, through simulation of control processes and the progress of microclimate parameters within a farm's space, for a given combination of conditions, to choose parameters of control in a way to provide the best conditions for the animals in their inhabited zone, while making the most efficient use of energy, emitted within the premises. Such an approach to microclimate control improves the energy efficiency of the process. This paper aims at algorithmic modelling of different physical processes, represented as separate subroutines, describing the processes within a stream of air, fed into a stock-breeding premise.

Some equivalent stress methods, applicable for life prediction in case of multiaxial loading, are presented in this paper, such as empirical equivalent stresses, frequency and “signed von Mises” stress. To apply the latter method, a calculation program that allows the transformation of a fluctuating load cycle into a fully reversed cycle is developed. The authors extend the equivalent stress concept towards critical plane models. This is illustrated by a calculated equivalent shear stress based on the Yokobori criterion. Both the „signed von Mises” and Yokobori approaches have the advantage of allowing multiaxial fatigue calculations for limited durability, as opposed to classical methods which are applicable only for unlimited durability.

This paper presents an experimental method to determine the relaxation of ,,Young’s modulus” of elasticity and the relaxation time at static compression of apples, maintaining their integrity. We showed the theoretical basis of the method using the creep test by considering the behavior of linear viscoelastic rheological bodies physical model described by the Burgers model composed of elastic and viscous linear elements. It presents the mathematical model to describe the relaxation modulus of elasticity and experimental results for three varieties of local apples: Idared, Jonathan, Golden Delicious. The data obtained is useful in predicting the time of the storage in certain packages. We present a numerical calculation application for evaluation of storage for the three varieties of apples used in experiments.

This paper consists of the study and optimising of the cold cycle in a frozen vegetable plant in La Rioja (Spain). Various investigations have been undertaken to reduce consumption and improve the operability of the equipment used in the process. The paper describes the procedure for determining the operating parameters of the cold cycle, the data obtained and a series of improvement proposals, applied to an actual case study in a frozen vegetable plant in La Rioja (Spain). The study reveals the fragility of the production system insofar as it depends on atmospheric conditions to condense the ammonia in the cold cycle. The analysis of the existing production processes and the products and sub-products generated revealed a heat sink that could be used, based on treated waste water. The study also provides an analysis procedure specific to this type of industry [1].

In this paper is presented the dependence of the efficiency of separation process for system such as solid-gas in the cyclone according to the geometrical characteristics of the inlet and outlet . The measurements were made on a laboratory pilot plant witch permits the modification of cyclone inlet and outlet sections. The determination of the separation efficiency was made by comparing the quantity of material introduced in system and the quantity recovered in the cyclone collection bunker. During the experimental research it were also measured the speed and the temperature of the air stream and the pressure in different points of transport and separation route.

The correct feeding of fresh air in a stock-breeding farm is a decisive factor for achieving high quality microclimate sustenance. Distributed dozed feeding of input air is a method, allowing for the achievement of best microclimate parameters in the animal zone, while at the same time making the most efficient use of the energy, emitted in the premises. The application of this method requires constant control of energy and temperature-humidity processes in the farm on the basis of a mathematical model. This paper aims at developing a model, describing the processes in a stream, fed into stock breeding farm premises.

Based on virtual instrumentation, we developed an ECG monitoring system for fast evaluation of heart health. We use low cost components for data acquisition: USB experiment interface board K8055 designed for computer peripherals and EKG-V2 amplifier module for ECG signal. The system has low power consumption and is very easy to operate. Since the acquisition board works at low sampling frequency for a more accurate representation of ECG signal, a common interpolation detection method was used.

The article presents the risk management analysis of Deepwater Horizon drilling rig into the context of international trend in exploiting oil and gas reserves in high water depth. Legislation influence in oil and gas industry and competent on site risk management entities added value for maintaining risk as low as possible considering development of offshore industry are also presented.

In the present paper is presented a theoretical research about the lifetime determination of pneumohydraulics accumulators under fatigue conditions. Spherical accumulators were analyzed because, as is known, they have indisputable advantages towards the cylindrical accumulators. The analysis presented is based on the methods of fracture mechanics of materials, considering that in the material structure were detected cracks with different shapes and sizes. The proposed method is illustrated with an example of calculation applied to a spherical shape accumulator.

This paper presents the results of an experimental research on the properties of “It” gaskets, which are used to ensure the tightness of flanged joints at pressured vessels. In this work, were considered the vessels working at variable pressure and high temperature. Experimental data are used to determine a general relation for calculating the endurance reduction factor of the flanged joints. This factor is recommended for determining the safe lifetime of the gasket, which is the most sensitive constructive element of flanged joints.

This paper outlines the methodology and the results of the experimental analysis performed by the authors regarding the fatigue behaviour of wraps made of new composite materials, obtained by the reinforcement with glass fibre fabric of an epoxy matrix, applied for repairing metal loss defects on steel pipes of oil, liquid petroleum and natural gas transmission pipelines. The information herein and the aspects explained in this paper must be used for determining the thickness of composite material wraps used to repair pipelines.