Starting from the fact that the natural gas engineering profession is generally associated with a high occupational risk, the current paper aims to help increase the safety of natural gas wells and ...reduce the risk of work-related accidents, as well as the occurrence of professional illnesses, by applying an assessment method that has proven its efficiency in other industrial areas in combination with a computer-aided design software. More specifically, the paper focuses on two main research directions: assessing the explosion risk for employees working at natural gas wells and indicating areas with a higher explosion hazard by using a modern software that allows their presentation in 3D. The appropriate zoning of industrial areas allows to group the various functional areas function of the probability of the occurrence of a dangerous element, such as an explosive atmosphere and subsequently it allows also to correctly select the electrical and mechanical equipment that will be used in that area, since electrical apparatuses that are otherwise found in normal work environments cannot generally be used in areas with explosion hazard, because of the risk that an electric spark, an electrostatic discharge etc. ignites the explosive atmosphere.
The accidental or historic contamination of soils with hydrocarbons, in areas crossed by oil pipelines or where oil- or gas-extraction installations are located, is a major concern and has ...significant financial and ecological consequences, both for the owners of those areas and for the oil transportation or exploitation companies. Therefore it is very important to find the optimal method for removing the pollution. The current paper presents measures, mainly involving bioremediation, recommended and applied for the depollution of a contaminated area in Romania. While the topic of dealing with polluted soils is well-established in the Romanian speciality literature, bioremediation is a relatively novel approach and this paper presents important considerations in this regard. Contaminated soil samples were taken from 10 different locations within the targeted area and subjected to a thorough physical and chemical analysis, which led to determining a specific scoring table for assessing the bioremediation potential of the various samples. This has allowed the authors to establish for each of the sampled areas the best mix of factors such as nutrients (nitrogen, phosphorus, potassium), gypsum, microelements etc., that would lead to obtaining the best results in terms of the contaminants' biodegradation.
Even if modern processing technologies seem to have gained much ground during recent years, more conventional ones, such as casting, continue to retain their well determined area of applications, ...given the advantages offered in this regard. One major problem is that many aspects related especially to the casting of small-size parts, continue to be based on empirical data and not on scientifically proven information. Therefore, this paper presents a new approach to the problem of determining the optimal shape of the sprue for the centrifugal casting of small-size parts, such as those employed for example in prosthetic applications. The method is based on calculating the trajectory followed by an infinitesimal particle of molten metal from the melting crucible to the casting mould, under the influence of the various forces that intervene.
This paper presents the results of experimental researches referring to the corrosion resistance of A541 class 6 steel with plasma nitriding treatment, steel used in the construction of auxiliary ...components for nuclear power plants. The polarization curves and Evans diagrams for electrode potential and for the intensity of the corrosion current of parts inserted into a 3% NaCl aqueous solution have been traced. The interpretation of the diagrams shows a good corrosion resistance of this steel, with a large passivation interval.
Certain areas of machined parts need to be protected against hardening induced by thermochemical treatments such as plasma nitriding (ion nitriding). When plasma nitriding is applied to metallic ...parts that have a local paint-based protection, the elementary fundamental physical-chemical processes that take place at the cathode change significantly. As a consequence of the observations and conclusions obtained after the experiments with the special protective paints for ion nitriding, this paper presents an analysis of the way in which the basic cathode processes are or not influenced by the presence of protection layers.
The outbreaks of duck pasteurellosis which occur during monsoon period, caused by avian strains of Pasteurella multocida, is a serious problem with high mortality and morbidity affecting younger age ...groups. Polyalthia longifolia (P. longifolia)) leaves which had antibacterial action, was tested for its efficacy against P. multocida by in vitro methods. The successive extracts of the plant materials were tested for its antibacterial effect using microtitre plate technique (to estimate the minimum inhibitory concentration, MIC) and disc diffusion method was performed to estimate the zone of inhibition. Microtitre plate technique was assayed by dissolving the plant extracts in sterile DMSO except the aqueous extracts which were dissolved in sterile distilled water. Various concentrations, 200 ìg, 500 ìg and 1 mg/well, of successive extracts of P. longifolia were used to find out the MIC. Disc diffusion method was performed with successive extracts of P. longifolia leaves at 200 µg, 500 µg and 1 mg concentrations. The results from the above in vitro assay revealed the efficacy of acetonic extract of P. longifolia leaves against duck pasteurellosis. The acetonic extract was further subjected to spectrophotometric, thin layer chromatography and high performance thin layer chromatographic analysis. The results of the present study could describe the antipasteurellosis activity of P. longifolia leaves.
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