THE USE OF DRONES AND SENSORS IN AGRICULTURE

This paper presents the possibilities and benefits of using drones in agriculture, especially in precision agriculture. In the first part of the paper, basic notions regarding drones in the agricultural context, legislative and flight safety aspects are presented, defined and clarified. In the second part of the paper, the most used sensors in agriculture are introduced, the benefits and the main stages of using drones in agriculture are presented, related to the life span of a crop and the duration of the agricultural year. This paper encourages and justifies the use of drones both in current agricultural operations and by applying photogrammetric methods and generating digital products such as orthophoto plans, thematic maps and digital terrain models

Ecological briquettes from sunflower seed husk

The paper aims to use the waste of sun-flower hulls in order to obtain some lignocellulosic briquettes as renewable solid fuels. First, the sunflower seed husks were ground, after that they were sorted and only the fractions corresponding to the briquettes and pellets were used. After obtaining the stable briquettes there were determined the physical and caloric properties of briquettes manufactured from sunflower husks, as potential alternative biofuels. The moisture content, ash content and density of the briquettes have been determined and correlated with their calorific properties, namely the calorific value and calorific density. The experimental results have indicated that, even if the self-adhesion of sunflower seed hulls is less than that of wood sawdust, they have a better behaviour in humid environment. Good results make it possible to use these briquettes for both household heating systems and thermal power plant

Ecological briquettes from sunflower seed husk

The paper aims to use the waste of sun-flower hulls in order to obtain some lignocellulosic briquettes as renewable solid fuels. First, the sunflower seed husks were ground, after that they were sorted and only the fractions corresponding to the briquettes and pellets were used. After obtaining the stable briquettes there were determined the physical and caloric properties of briquettes manufactured from sunflower husks, as potential alternative biofuels. The moisture content, ash content and density of the briquettes have been determined and correlated with their calorific properties, namely the calorific value and calorific density. The experimental results have indicated that, even if the self-adhesion of sunflower seed hulls is less than that of wood sawdust, they have a better behaviour in humid environment. Good results make it possible to use these briquettes for both household heating systems and thermal power plant

Vibration-Assisted Welding of 42CrMo4 Steel: Optimizing Parameters for Improved Properties and Weldability

This study advances the vibration-assisted welding (VAW) technique for joining medium-carbon, low-alloy steels, which are typically challenging to weld. Traditional welding methods suggest low linear energy and mandatory pre- and post-heating due to these steels’ poor weldability. However, VAW employs a vibrating table to maintain part vibration throughout the automatic MIG/MAG welding process. This study tested the VAW technique on 42CrMo4 steel samples, achieving satisfactory weld quality without the need for pre- and post-heating treatments. This research revealed that while vibration frequencies between 550 Hz and 9.5 kHz minimally affect the appearance of the weld joint, the oscillation acceleration has a significant impact. The acceleration along the weld axis (ax), combined with the welding speed and vibration frequency, affects the weld surface’s appearance, particularly its scaly texture and size. Lateral acceleration (ay) alters the seam width, whereas vertical acceleration (az) affects penetration depth at the root. Notably, if the effective acceleration (aef) surpasses 40 m/s2, there is a risk of molten metal expulsion from the weld pool or piercing at the joint’s base. The quality of the joints was assessed through macroscopic and microscopic structural analyses, micro-hardness tests in the weld zone, and bending trials. The mechanical properties of the VAW samples were found to be acceptable, with hardness slightly exceeding that of the samples subjected to pre- and post-heating. Moreover, the VAW process significantly reduced energy consumption and operational time. The employed vibration system, with a power rating of 100 W, operates for just a few minutes, resulting in substantially lower energy usage compared to the traditional pre- and post-heating method, which typically requires a 5 kW electric furnace

Carbon Nanoparticle-Supported Pd Obtained by Solar Physical Vapor Deposition

Palladium supported on carbon nanoparticles has been obtained on a specially designed ceramic catalyst, obtained by thermal spraying on a copper substrate, starting from Pd/C targets. Solar physical vapor deposition in argon, an environment-friendly and energy-efficient alternative to arc or chemical vapor deposition, has been employed as a means of target vaporization at CNRS-PROMES facility in Odeillo, France. The obtained nanoparticles have a spherical-porous morphology with diameters ranging from 50 to 120 nm and specific sorption areas of 50,000 m2/g. The XRD diffractograms indicate the presence of dominatingly crystalline short-range ordered graphene oxide layers, in contrast with the amorphous Pd/C starting precursor. The presence of palladium (0.6% wt.) at the surface of the nanoparticles was proved by the EDX and XRD analyses, making the synthesized material useful in applications such as catalysis or gas sorption

Thermal and Sound Insulation Properties of Organic Biocomposite Mixtures

Sustainable building materials with excellent thermal stability and sound insulation are crucial for eco-friendly construction. This study investigates biocomposites made from cellulose pulp reinforced with beeswax, fir resin, and natural fillers like horsetail, rice flour, and fir needles. Eight formulations were obtained, and their thermal resistance, oxidation temperature, and acoustic properties were evaluated. Biocomposites exhibited significant improvements compared to conventional materials. Oxidation temperature onset increased by 60–70 °C compared to polyurethane foam or recycled textiles, reaching 280–290 °C. Sound absorption coefficients ranged from 0.15 to 0.78, with some formulations exceeding 0.5 across mid-frequencies, indicating good sound-dampening potential. These findings demonstrate the promise of these biocomposites for sustainable construction, offering a balance of thermal and acoustic performance alongside environmental and health benefits