Research on heat transfer during the drying process of agricultural seeds

Development of computers and software made possible CFD (Computational Fluid Dynamics) modeling of heat transfer phenomena in drying process of agricultural seeds. Validation of the mathematical model of the heat transfer process in a porous medium was achieved by measuring the seed temperature at several points of the seed layer in a dryer. The CFD simulation obtained the temperature profile in the seed layer on the three thicknesses studied. Simulation and experiment allow optimization of the drying process by increasing the quality of dried seeds with low energy consumption. The results of the simulation and experimental data give a dry layer optimum thickness of the 100 mm for all tested seeds

Valorization on the energy potential of Pistia stratiotes in sustainable agriculture-review

Of late years, aquatic plants have received increased attention due to their energy potential in sustainable agriculture. Pistia stratiotes also belongs to this category. A vital aspect in sustainable agriculture, to which there is a growing tendency, is the use of environmentally friendly methods. Aquatic plants are used as raw materials for various applications, such as food industry, health, agriculture and aquaculture, ecosystem management, being an essential renewable resource. Due to population growth, both developed and developing countries are mainly facing problems related to future energy security and the proper use of natural resources. As the search for renewable energy resource intensifies, there is a growing drive to identify and develop promising, environmentally friendly, low-carbon and low-carbon bioenergy raw materials. Fuel demand is rising, while food costs and waste are gradually rising. It is therefore necessary to address waste management and reduce pollution caused by excessive energy use and industrialization. The current study focuses on the potential for harnessing renewable energy in the Nile lettuce (Pistia stratiotes), namely, highlighting the process of residual biomass, biofuel and compost

Use of the experimental modal analysis for analytical lifetime estimation of a bogie frame

The fatigue strength validation by tests of the railway bogie frames requires existence of an expensive laboratory and a long time for testing of about 6 to 10 months. Considering these aspects, the European norms admit that fatigue tests can be replaced by finite elements analysis (FEA), with the condition that analytical model to be correctly realized and validated by tests. Experimental modal analysis (EMA) provides a powerful tool for validation of the FEA model by experimental data. The article presents an application for assessment of the fatigue strength of a three-axle locomotive bogie frame. Using Ansys, was carried out the structural analysis of the bogie frame, resulting the modal model characterized by the modal parameters: Eigen frequencies and Eigen shapes. The analytical model was validated by an EMA application carried out on the bogie frame and correlation analysis of the EMA and FEA models. Using a special measuring wheel set, were determined the wheelrail interaction forces for various locomotive running conditions. The analytical structural model, validated through experimental data, and the data files containing the wheel-rail interaction forces, constitutes the input data for the nCode program that evaluates the bogie frame lifetime using appropriate stress curves and a recognized accumulation of damage hypothesis, e.g. the Palmgren-Miner

Analytical evaluation of the lifetime of a three-axle bogie frame using the analytical model validated through experimental modal analysis

The fatigue strength validation by tests of the railway bogie frames requires existence of an expensive laboratory and a long time for testing, of about 6 to 10 months. Considering these aspects, the european norms admit that fatigue tests can be replaced by finite elementes analysis, with condition that analytical model to be correctly realized and validated by tests. Experimental modal analysis provides a powerful tool for validation of the FEA model through experimental data. The article presents an application for analytical assessment of the fatigue strength for a three-axle locomotive bogie frame, before sending it to the laboratory fatigue tests. Using Ansys, it was carried out the structural analysis of the bogie frame, rezulting the modal model characterized by the modal parameters: eigenfrequencies and eigenshapes. The analytical model was validated through an EMA application carried out on the bogie frame and correlation analysis of the EMA and FEA models. The analytical model and data files containing the simulated vertical, transverse and twist loads, applied to the bogie frame according to EN13749/2011, constitutes the input data for nCode program, that evaluates the bogie frame lifetime using appropriate stress curves and a recognized hypothesis of damage accumulation

Evaluation of hand transmitted chainsaw vibrations during wood cutting

Forestry workers are exposed to vibrations from chainsaws which usually are not taken into consideration from the negative impact point of view on their health. However, in time, these vibrations could cause trepidation disease which will affect the worker neuro-muscular and locomotory apparatus. One mean to mitigate the vibrations impact is to measure and determine the worker’s exposure level to vibrations during worktime and to dispose the proper measures to reduce their negative impact. Within this paper will be presented experimental results obtained for vibration data recorded on a chainsaw during wood cutting in real life conditions. The equivalent vibration was measured at both front and end handles level and the biggest value was used for calculation of the human exposure level

System for measurement of interaction forces between wheel and rail for railway vehicles

Determination of the interaction forces between wheel and rail of railway vehicles is essential for assessment of the vehicle dynamic characteristics from point of view of running safety and rail loading as well as for approval the vehicle and alignment them to the Technical Specification for Interoperability. The direct measurement of transverse and vertical interaction forces using the existing full-disk wheel is practical impossible due to the impossibility of separating the two types of forces. To avoid this impediment it was realized a measuring wheelset fitted with 12 spokes achieved as force transducers for measurement of the vertical forces and 12 spokes achieved as force transducers for measurement of the transverse forces. The measuring wheelset was calibrated as a force transducer and was used to determine the wheel and rail interaction forces for LE-MA 6000kW electric locomotive made by Softronic Craiova. The article presents the measuring wheelset, the calibration principle and the calibration characteristics as well as some time history of the main parameters which characterize the running safety and rail loading, determined in the on-track tests

Automation and Remote Control of an Aquatic Harvester Electric Vehicle

Electric boats are evolving, following the trend of imposing electric powered vehicles in all transportation solutions. For a research project, a reed and aquatic weed harvester, the author’s goal is to develop an experimental electrical vehicle aimed at solving several particular problems such as: small speed, big throttle, high maneuverability, big load capacity, small draught and affordable cost. The solution comprises of one electric motor powered by a converter supplied from Li-Ion batteries, which drives a hydraulic pump for simultaneous operation of two lateral-placed paddle wheels and one complex mechanism of cutter and conveyor. The control system of this vehicle consists of one remote controller, with bidirectional radio communication to three on-board controllers used for the management of the electro-hydraulic actuators, the electric motor and the battery storage system. The hardware and the software architectures are presented, underlining the automated operations designed to increase the safety, the maneuverability and the predictability of the vehicle. The advantages of the use of control electronics is the increasing operability of the vehicle by supervising the available stored energy and the predicted consumption of energy, the fast and remote assistance in case of operational failure using online diagnose and the operation optimization by selecting the best load profile for the cutter and for the paddles. The results of this research are the validation of the proposed hardware and software architectures used for the control of an electro-hydraulic vehicle and the feasibility of using radio communication and remote diagnose for vehicle control

Experimental modal analysis of an electric locomotive body

The study of the structural dynamics is essential for understanding and assessing of any engineering product performance, knowledge of dynamic structural response being fundamental to ensuring a sustainable and safe product functioning. From all techniques for structural response assessment, the experimental modal analysis (EMA) provides one of the most comprehensive tools for collecting the experimental data, relevant for structure investigation and assessing of the structural response under normal or imposed operating conditions. Once identified the structure in terms of modal model, it can begin to its optimization to face new challenges or functioning tasks. The article presents an experimental modal analysis application, performed on a LEMA 6000kW electric locomotive body on the production cycle of SC Softronic Craiova. The application was made to validate the dynamic finite elements model realised in order to certify the crashworthiness locomotive design and to evaluate the body interaction with bogie and track to avoid the locomotive structural resonance phenomena

Experimental modal analysis of an electric locomotive body

The study of the structural dynamics is essential for understanding and assessing of any engineering product performance, knowledge of dynamic structural response being fundamental to ensuring a sustainable and safe product functioning. From all techniques for structural response assessment, the experimental modal analysis (EMA) provides one of the most comprehensive tools for collecting the experimental data, relevant for structure investigation and assessing of the structural response under normal or imposed operating conditions. Once identified the structure in terms of modal model, it can begin to its optimization to face new challenges or functioning tasks. The article presents an experimental modal analysis application, performed on a LEMA 6000kW electric locomotive body on the production cycle of SC Softronic Craiova. The application was made to validate the dynamic finite elements model realised in order to certify the crashworthiness locomotive design and to evaluate the body interaction with bogie and track to avoid the locomotive structural resonance phenomena

Experimental research on obtaining pelletized feed recipes with applicability in semi-intensive aquaculture systems

Romanian aquaculture can be economically sustainable and viable if the farm is profitable, the farm's income is secure, and the products are accepted by customers. In many cases, improving environmental sustainability can lead to optimizing economic sustainability. For example, a more efficient use of food and nutrients or reduced water and energy consumption are not only beneficial for the environment, but can also reduce costs. Growth in polyculture system, which represents the growth of several species of fish in the same space (pond, pool, basin, etc.), and diversification of supply can increase consumer confidence and thus economic sustainability. The diet must provide the fish with the nutrients necessary for growth (proteins with a plastic role) and provide the energy necessary for physiological processes. Quality food ensures good development, facilitates reproduction and prevents extremely harmful diseases in an aquaculture system. The paper presents a series of experimental recipes for pelletized feed made using an experimental model of small capacity. Nutrient pellets made for feeding fish from the Cyprinid family were analyzed in terms of gross energy value, ash content, moisture, mechanical durability over time, bulk density etc