Case Study regarding the test of the new screw compressor with high delivery pressure - 45 bara - on the test bench (with air)

Screw compressors, which are part of positive displacement compressors, can find an increasing use in gas industry and beyond due to their advantages. Maximal parameters of these devices, done by Comoti under GHH-Rand license stop at a maximum flow of 3000 Nm3/hour and 26 bara discharge pressure. The needs of potential beneficiaries have imposed the necessity to design and manufacture a new family of screw compressors and oil injection able to develop a discharge pressure of 45 bara with flow rates up to 5000 Nm3/hour. This paper presents the design and experimental test phases – for the first screw compressor with discharge of pressure up to 45 bara – CU90 HP. Continue research and development have allowed to this type of screw-compressor – to find a market position, diversifying its size range in the last decade in a manner more explosive, if we refer to other types of compressors

Traffic Noise Pollution in a Historical City Center - Case Study Project within Environmental Engineering Field of Study

Abstract Noise reduction for urban areas, especially noise generated by traffic is one of the major problems in today's European cities. This paper is focused on more aspects that are addressing to traffic noise, like pavement, driver's behavior, frequency of stops, pick hours, traffic agglomerations, etc. Research leading to this paper was conducted within the project "Adaptation to the Climate Change" developed in partnership with Environmental protection Agency Sibiu, focusing for this case study on traffic related pollution in a historical city center of Sibiu. Were considered three types of pavements (cobblestones, streets covered with dense asphalt, and graded asphalt road surfaces), three types of vehicles (small passenger car, family car and SUV), and testing's were done using 3M Quest SoundPro Sonometer. Higher noise levels were registered for cobblestone and dense asphalt surfaces. Acoustic measurements and maps emphasizing studied are presented, and the identified parameters considered to be related to the traffic noise are given

Probabilistic functional tractography of the human cortex revisited

In patients with pharmaco-resistant focal epilepsies investigated with intracranial electroencephalography (iEEG), direct electrical stimulations of a cortical region induce cortico-cortical evoked potentials (CCEP) in distant cerebral cortex, which properties can be used to infer large scale brain connectivity. In 2013, we proposed a new probabilistic functional tractography methodology to study human brain connectivity. We have now been revisiting this method in the F-TRACT project (f-tract.eu) by developing a large multicenter CCEP database of several thousand stimulation runs performed in several hundred patients, and associated processing tools to create a probabilistic atlas of human cortico-cortical connections. Here, we wish to present a snapshot of the methods and data of F-TRACT using a pool of 213 epilepsy patients, all studied by stereo-encephalography with intracerebral depth electrodes. The CCEPs were processed using an automated pipeline with the following consecutive steps: detection of each stimulation run from stimulation artifacts in raw intracranial EEG (iEEG) files, bad channels detection with a machine learning approach, model-based stimulation artifact correction, robust averaging over stimulation pulses. Effective connectivity between the stimulated and recording areas is then inferred from the properties of the first CCEP component, i.e. onset and peak latency, amplitude, duration and integral of the significant part. Finally, group statistics of CCEP features are implemented for each brain parcel explored by iEEG electrodes. The localization (coordinates, white/gray matter relative positioning) of electrode contacts were obtained from imaging data (anatomical MRI or CT scans before and after electrodes implantation). The iEEG contacts were repositioned in different brain parcellations from the segmentation of patients' anatomical MRI or from templates in the MNI coordinate system. The F-TRACT database using the first pool of 213 patients provided connectivity probability values for 95% of possible intrahemispheric and 56% of interhemispheric connections and CCEP features for 78% of intrahemisheric and 14% of interhemispheric connections. In this report, we show some examples of anatomo-functional connectivity matrices, and associated directional maps. We also indicate how CCEP features, especially latencies, are related to spatial distances, and allow estimating the velocity distribution of neuronal signals at a large scale. Finally, we describe the impact on the estimated connectivity of the stimulation charge and of the contact localization according to the white or gray matter. The most relevant maps for the scientific community are available for download on f-tract. eu (David et al., 2017) and will be regularly updated during the following months with the addition of more data in the F-TRACT database. This will provide an unprecedented knowledge on the dynamical properties of large fiber tracts in human.Peer reviewe

EXPERIMENTAL RESEARCHES CONCERNING THE DETERMINING OF THE OPTIMAL PROCESSING PARAMETERS AT THE ELECTRO- DISCHARGE MACHINING OF SEVERAL STEEL QUALITIES

Abstract The experimental researches described in this paper sought to verify an earlier theoretical study of the authors on the elementary processes which accompany the processing by electrodischarge machining of the steels qualities OLC 60, 50 VCr 11, 35 CrNi 45. The changes in physical-chemical and technological parameters were determined and compared

The optimization of welding regimes for obtaining corrosion resistant welded constructions

Most of the technological equipment has welded metal structures in its composition, which are strongly affected by the corrosion phenomenon. In order to achieve a reduction of the corrosion phenomenon it is very important that the welded joints are made using optimal parameters of the welding regime. In the research were made 6 different welded specimens, respectively 3 for the welded T-shaped joint and 3 for the cross-welded joint. The welded joints were made of 10 mm thick using S 355JR steel by the MAG welding process and using welding wire G4 Si 1 as an additive. For the 6 specimens were made analyzes of the metallographic structure thus observing what are parameters of the welding regime that allows to obtain the welded joints with high corrosion resistance

Constructive Optimization of Vulcanization Installations in Order to Improve the Performance of Conveyor Belts

Conveyor belts of special importance must have superior mechanical characteristics. The joining by vulcanization of the conveyor belts allows to obtain superior performances, but it has been found that at the vulcanizing joint of the conveyor belts, there is a “bell”-type defect. This type of defect can cause the quick removal of the conveyor belts from use; thus, within this paper, we realized the constructive optimization of vulcanization installations using the finite element method (FEM). Thus, the FEM analysis was performed for the installation used at the present time, which has four spacers for stiffening, moving to the next stage to a stiffening system with seven spacers and, in the last stage, it was proposed to use a stiffening plate. The joined conveyor belts were of type ST 2000, and by the constructive optimization of the vulcanizing press type DSLQ, the bell-type defect was greatly reduced. Also, an analysis of the effects that the constructive optimization of the vulcanization installation has on the resistance to extraction of the metallic insert from the rubber matrix of the costs determined by the proposed constructive modifications, has been performed

Considerations on determining the explosion risk and the areas with explosion hazard in a natural gas compressor station

Compressor stations are important components within natural gas transportation networks. The current paper analyses some of the safety aspects involved in the operation of such facilities – on the one hand related to the explosion risk for employees working in compressor stations and on the other hand related to determining to the areas with increased explosion hazard in such a station, in order to help reducing work-related accidents and the occurrence of professional illnesses. The explosion risk is determined based on a method devised by the National Institute for Research and Development for Environmental Protection Bucharest, while the explosion hazard areas are determined and displayed with the help of the software package AutoCAD Plant 3D

CURRENT STAGE OF HOMOLOGATION OF THE FIRST ROMANIAN RABBIT BREED – TRANSYLVANIAN GIANT RABBIT

The paper presents the current state of the homologation process of the first Romanian rabbit breed. Animal production very often takes into account aspects such as conservation of national genetic resources, but also an improved productivity. These two issues are the main reasons for creating the first rabbit breed in Romania: Transylvanian Giant Rabbit Breed. We point out here our latest scientific achievements – accomplished during 2011