CONSIDERATIONS CONCERNING THE AUTOMATION OF PROTECTED SPACES

In the last period there is an intensification of the researches oriented towards the automation of the specific activities of the horticultural production in protected spaces. The greenhouses offer a shelter in which a microclimate suitable for plants is maintained, which is obtained by regulating / adjusting the heat and the amount of light coming from the sun, by means of actuation systems (actuators-technical devices that generate an action to reach a specific objective). The paper presents a brief communication on the main drive systems used in greenhouses: ventilation and cooling systems; heating systems; irrigation systems, whose drive systems are mainly composed of electrical devices, especially electric motors or pump

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

Matematičko modeliranje i primena u akustičnim aplikacijama u poljoprivredi

The article presents a discussion and a comparison of modeling methods for acoustic sources, it compares performance models and presents possible applications. The mathematical models are presented and compared: the natural and theoretical model that is based on the theoretical and empirical model of acoustic wave equation of noise spatial variation. The models are compared in terms of sound intensity level (which is calculated by exact formulas from the wave function solution of the acoustic waves equation) and noise levels provided by the theoretical and empirical model. It is shown that in most cases, both are models whose results must be calibrated in order to give results matching reality. Finally we compare the field application of each of the two models.U radu je predstavljeno ispitivanje i poređenje metoda modeliranja za akustične izvore, poređene su performance modela i predstavljene moguće aplikacije. Predstavljeni i poređeni su sledeći matematički modeli: prirodni i teorijski model koji se zasniva na teorijskom i empirijskom modelu jednačine zvučnih talasa prostorne varijacije buke. Modeli su poređeni prema nivou intenziteta zvuka (koji je računat po egzaktnim formulama iz rešenja funkcije talasa jednačine zvučnih talasa) i nivoa buke dobijenih teorijskim i empirijskim modelom. Pokazano je da u najvećem broju slučajeva rezultati oba modela moraju da se kalibrišu da bi se dobili rezultati koji se slažu sa stvarnim vrednostima. Konačno, uporedili smo i poljske aplikacije oba modela

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

Drones and windbreaks

The article presents a possibility of applying the techniques specific to the drones (UAV) in order to estimate the efficiency, and optimize the windbreaks (vegetative barriers, forest curtains).In the first part the article presents a variant of determination of the dynamic and optical porosities of forest protection curtains using one or two drones simultaneously. In the second part, ascertaining some language inaccuracies, it observes that the issue of the efficiency of the forest curtains became a problem of mitigation of wind intensity. Finally, the last proposed application shows that using the drones, you can estimate the protected volumes behind the curtains, basically giving up the optical porosity. In order to achieve these applications, there is an essential condition: records of the magnitude of the wind speed and of the coordinates must not be excessively affected by the wind

Median sternotomy – gold standard incision for cardiac surgeons

Sternotomy is the gold standard incision for cardiac surgeons but it is also used in thoracic surgery especially for mediastinal, tracheal and main stem bronchus surgery. The surgical technique is well established and identification of the correct anatomic landmarks, midline tissue preparation, osteotomy and bleeding control are important steps of the procedure. Correct sternal closure is vital for avoiding short- and long-term morbidity and mortality. The two sternal halves have to be well approximated to facilitate healing of the bone and to avoid instability, which is a risk factor for wound infection. New suture materials and techniques would be expected to be developed to further improve the patients evolution, in respect to both immediate postoperative period and long-term morbidity and mortality

Investigation of Scanning Strategies and Laser Remelting Effects on Top Surface Deformation of Additively Manufactured IN 625

The main drawbacks of the Laser Powder Bed Fusion (LPBF) process are the surface quality and dimensional accuracy of manufactured parts due to the edge and corner effects. These effects can be diminished by using an appropriate balance of the process parameters and scanning strategies. This paper focuses on the assessment of reducing the edge and corner effects that occur in additively manufactured IN 625 alloy via the LPBF technique by varying the hatch angle rotation (by 45°, 67°, and 90°) and volumetric energy density (VED), and using the laser top surface remelting technique (LSR). The edge and corner effects of the cubic samples were quantitatively evaluated on the top surface by 3D laser surface scanning. It was found that the edge and corner effects became more pronounced in the cases of samples built with no contour and hatch angles of 45° and 67°, while the smallest deformations were obtained when the hatch angle was rotated by 90°. Moreover, the heights of both the edge and corner ridges increase as the number of remeltings passing the top layer increases. Conversely, when a lower VED was used for melting the top layer(s) of the samples, the edge and corner ridges were slightly reduced