Research on deformations which appear in within the metal structures of mining equipment

Metal structures of the mining equipment are made of a steel with good weldability and mechanical characteristics corresponding and namely St 52.3 steel that allows the use of these metal structures in heavy duty. Metal structures of the mining equipment are very large structures and strong requested mechanical, and in these conditions during exploitation can occur large deformations at these that may cause a decrease in the exploitation safety of mining equipment. Research has followed in principal the analyze of deformations appear in metallic structures, and for realizing the researches has been used both a dimensional analysis and one that is based on the finite element method

The optimization of welding regime parameters at shielded metal arc welding (SMAW) by mathematical modeling

The realized researches followed the determining of mathematical models that allow the optimization of the welding process in order to obtain welded joints with certain values of the mechanical characteristics. Thus, there were established mathematical models of dependence of mechanical characteristics of welded joints (Rm, Rp02, Z, A, KCV 20°C) of each parameter of welding regime (Iw, Uw), and also, mathematical models that offer cumulative dependence of mechanical characteristics of both parameters of welding regime.The researches have been carried out using steel E 36-4 as base material and as filler material basic electrodes, type E7018 and the applied welding procedure was the process: shielded metal arc welding (SMAW)

The Trigger Mechanism of Recurrent Solar Active Region Jets Revealed by the Magnetic Properties of a Coronal Geyser Site

Solar active region jets are small-scale collimated plasma eruptions that are triggered from magnetic sites embedded in sunspot penumbral regions. Multiple trigger mechanisms for recurrent jets are under debate. Vector magnetic field data from SDO-HMI observations are used to analyze a prolific photospheric configuration, identified in extreme ultraviolet observations as a `Coronal Geyser', that triggered a set of at least 10 recurrent solar active region jets. We focus on interpreting the magnetic fields of small-scale flaring sites aiming to understand the processes that govern recurrent jet eruptions. We perform a custom reprocessing of the SDO-HMI products, including disambiguation and uncertainty estimation. We scrutinized the configuration and dynamics of the photospheric magnetic structures. The magnetic configuration is described via the analysis of the photospheric magnetic vertical fields, to identify the process is responsible for driving the jet eruptions. We report that the two widely debated magnetic trigger processes, namely magnetic flux cancellation and magnetic flux emergence, appear to be responsible on a case by case basis for generating each eruption in our set. We find that 4 of 10 jets were due to flux cancellation while the rest were clearly not, and were more likely due to flux emergence.Comment: 19 pages, 6 figure, and 1 table. The Astrophysical journal, In pres

Researches on corrosion cracking phenomenon that occurs on welded of agricultural equipment

Welded construction equipments for agriculture are strongly stressed in terms of mechanics, but also in terms of environmental action and thus in many cases appears their wear by corrosion cracking phenomenon. After research it was noted that after a certain period of use of equipment, metallographic structure of welded steel structures has changed substantially and at the same time a change in the chemical composition of steel was also observed. In terms of chemical composition a reduction in carbon content was mainly observed, and an increase in sulfur content,determined mainly by the presence of large quantities of sulfur in the atmosphere. This sulfur in the atmosphere at the same time determines the acid action on metallic materials, by forming with water from precipitation of H2S. Key words

Optimal spectral lines for measuring chromospheric magnetic fields

This paper identifies spectral lines from X-ray to infrared wavelengths which are optimally suited to measuring vector magnetic fields as high as possible in the solar atmosphere. Instrumental and Earth's atmospheric properties, as well as solar abundances, atmospheric properties and elementary atomic physics are considered without bias towards particular wavelengths or diagnostic techniques. While narrowly-focused investigations of individual lines have been reported in detail, no assessment of the comparative merits of all lines has ever been published. Although in the UV, on balance the Mg+ h and k lines near 2800 Angstroms are optimally suited to polarimetry of plasma near the base of the solar corona. This result was unanticipated, given that longer-wavelength lines offer greater sensitivity to the Zeeman effect. While these lines sample optical depths photosphere to the coronal base, we argue that cores of multiple spectral lines provide a far more discriminating probe of magnetic structure as a function of optical depth than the core and inner wings of a strong line. Thus, together with many chromospheric lines of Fe+ between 2585 and the h line at 2803 Angstrom, this UV region promises new discoveries concerning how the magnetic fields emerge, heat, and accelerate plasma as they battle to dominate the force and energy balance within the poorly-understood chromosphere.Comment: Accepted for publication in the Astrophysical Journal. 12 pages, 2 figures, and 1 tabl

Mining the ESO WFI and INT WFC archives for known Near Earth Asteroids. Mega-Precovery software

The ESO/MPG WFI and the INT WFC wide field archives comprising 330,000 images were mined to search for serendipitous encounters of known Near Earth Asteroids (NEAs) and Potentially Hazardous Asteroids (PHAs). A total of 152 asteroids (44 PHAs and 108 other NEAs) were identified using the PRECOVERY software, their astrometry being measured on 761 images and sent to the Minor Planet Centre. Both recoveries and precoveries were reported, including prolonged orbital arcs for 18 precovered objects and 10 recoveries. We analyze all new opposition data by comparing the orbits fitted before and after including our contributions. We conclude the paper presenting Mega-Precovery, a new online service focused on data mining of many instrument archives simultaneously for one or a few given asteroids. A total of 28 instrument archives have been made available for mining using this tool, adding together about 2.5 million images forming the Mega-Archive.Comment: Accepted for publication in Astronomische Nachrichten (Sep 2012

739 observed NEAs and new 2-4m survey statistics within the EURONEAR network

We report follow-up observations of 477 program Near-Earth Asteroids (NEAs) using nine telescopes of the EURONEAR network having apertures between 0.3 and 4.2 m. Adding these NEAs to our previous results we now count 739 program NEAs followed-up by the EURONEAR network since 2006. The targets were selected using EURONEAR planning tools focusing on high priority objects. Analyzing the resulting orbital improvements suggests astrometric follow-up is most important days to weeks after discovery, with recovery at a new opposition also valuable. Additionally we observed 40 survey fields spanning three nights covering 11 sq. degrees near opposition, using the Wide Field Camera on the 2.5m Isaac Newton Telescope (INT), resulting in 104 discovered main belt asteroids (MBAs) and another 626 unknown one-night objects. These fields, plus program NEA fields from the INT and from the wide field MOSAIC II camera on the Blanco 4m telescope, generated around 12,000 observations of 2,000 minor planets (mostly MBAs) observed in 34 square degrees. We identify Near Earth Object (NEO) candidates among the unknown (single night) objects using three selection criteria. Testing these criteria on the (known) program NEAs shows the best selection methods are our epsilon-miu model which checks solar elongation and sky motion and the MPC's NEO rating tool. Our new data show that on average 0.5 NEO candidates per square degree should be observable in a 2m-class survey (in agreement with past results), while an average of 2.7 NEO candidates per square degree should be observable in a 4m-class survey (although our Blanco statistics were affected by clouds). At opposition just over 100 MBAs (1.6 unknown to every 1 known) per square degree are detectable to R=22 in a 2m survey based on the INT data, while our two best ecliptic Blanco fields away from opposition lead to 135 MBAs (2 unknown to every 1 known) to R=23.Comment: Published in Planetary and Space Sciences (Sep 2013

CONSIDERATIONS CONCERNING THE VALORIZATION OF THE JUICE OBTAINED FROM SUGAR SORGHUM STALK FROM ALCOHOL

 With a high production per hectare, sugar sorghum is a high value technical plant for farmers because from an average production of 70-80 t/ha, a high quantity of juice can be obtained, which can be used as such in the food industry (natural sweetener) or processed for the purpose of obtaining alcohol. The alcohol has a higher value/liter, can be stored more easily and its uses are multiple: in the food, pharmaceutical, chemical industry, etc

Pine Pitch Canker and Insects: Regional Risks, Environmental Regulation, and Practical Management Options

Producción CientíficaPine pitch canker (PPC), caused by the pathogenic fungus Fusarium circinatum (Nirenberg and O’ Donnell), is a serious threat to pine forests globally. The recent introduction of the pathogen to Southern Europe and its spread in Mediterranean region is alarming considering the immense ecological and economic importance of pines in the region. Pines in forests and nurseries can be infected, resulting in severe growth losses and mortality. The pathogen is known to spread in plants for planting and in seeds, and results from recent studies have indicated that F. circinatum may also spread through phoretic associations with certain insects. With this review, we aim to expand the current understanding of the risk of insect-mediated spread of PPC in different parts of Europe. Through the joint action of a multinational researcher team, we collate the existing information about the insect species spectrum in different biogeographic conditions and scrutinize the potential of these insects to transmit F. circinatum spores in forests and nurseries. We also discuss the impact of environmental factors and forest management in this context. We present evidence for the existence of a high diversity of insects with potential to weaken pines and disseminate PPC in Europe, including several common beetle species. In many parts of Europe, temperatures are projected to rise, which may promote the activity of several insect species, supporting multivoltinism and thus, further amplifying the risk of insect-mediated dissemination of PPC. Integrated pest management (IPM) solutions that comply with forest management practices need to be developed to reduce this risk. We recommend careful monitoring of insect populations as the basis for successful IPM. Improved understanding of environmental control of the interaction between insects, the pathogen, and host trees is needed in order to support development of bio-rational strategies to safeguard European pine trees and forests against F. circinatum in future.European Cooperation in Science and Technology (COST Action FP1406 PINESTRENGTH)Ministerio de Economía, Industria y Competitividad - Fondo Europeo de Desarrollo Regional (project AGL2015-69370-R)Portuguese Foundation for Science and Technology (contract IF/00471/2013/CP1203/CT0001)Russian Foundation for Basic Research (grant 17-04-01486)Saint Petersburg State Polytechnical University (project 2019-0420

RESEARCHES REGARDING THE OBTAINING OF JUICE FROM SUGAR SORGHUM STALK

Sugar sorghum is a technical plant with high energy value due to the high productivity obtained per hectare. By pressing of sugar sorghum strains it can be obtained a juice that can be further used in various forms: alcohol, ethanol, etc