No abstract

<p>This article tries to present the basic elements of the main guidelines, international standards and methodologies (methods) used in project management. In this category we include: the PMBOK®Guide (elaborated by the Project Management Institute), the PRINCE method (elaborated by the British Office of Government Commerce), the ISO 21500:2012 standard (elaborated by the International Organization for Standardization) etc. At the basis of these guidelines, standards and methodologies stay a great practice experience. Depending on the particularity and type of project, of management philosophy and culture of the organization that runs the project, we can choose to apply a certain guide, standard or methodologies (methods). The stated goal of these guidelines, standards and methodologies (methods) is to provide an optimum framework, the best practice for manage project to success. Applying these guidelines, standards and methodologies (methods) may be prerequisite project success, being a necessary but not always sufficient.</p>

A facile, ecofriendly, and cost-effective method was developed to prepare a microporous material based on natural chemically modified bentonite with silver ions (BN-Ag0). This material presents a good catalytic activity against Malachite Green (MG) dye and bacteriostatic activity against a newly isolated bacterium from sewage sludge named hereafter “ISO SS” and Escherichia coli (E. coli). BN-Ag0 was characterized by the following methods: energy-dispersive X-ray spectroscopy (EDX), scanning electron microscopy (SEM), Brunauer–Emmett–Teller (BET), Fourier-transform infrared (FTIR) spectroscopy, temperature programmed desorption (TPD) and X-ray Diffraction (XRD). The new bacterium ISO SS, was isolated using the technique of isolating a pure culture of anaerobically stabilized sludge. A mandatory characterization of ISO SS isolated strains from anaerobic stabilized sludge was performed in the process of identifying bacterial species. The cationic clay-based nanomaterial showed appreciable antibacterial activity against ISO SS, a Gram-negative bacterium. It also showed good activity against E. coli bacteria. As a catalyst in the catalytic ozonation of MG dye, BN-Ag0 significantly improves the oxidation time of the dye, due to its good adsorption and catalytic properties. The catalytic and antibacterial activities of the natural bentonite (BN) and of BN-Ag0 were examined using performant characterization techniques. The lifetime of the BN-Ag0 catalyst was also evaluated. Results obtained are expected to provide valuable findings for the preparation of a good microporous material with multiple functionalities.

No abstract

No abstract

Water jet cutting is one of the newest techniques in non-conventional machining processes. It is a flexible technology since the same equipment can be used to cut virtually any material, such as steel stainless steel, high-nickel alloys and polymer composites (usually, for these materials, the water jet is mixed with an abrasive material, the process being known as abrasive water jet cutting - AWJC) . Compared with the classical technologies, water jet cutting presents the following advantages: very low side forces during machining, it is rapid, it is silent, no thermal distortion, a good cutting accuracy and minimal burrs. To optimize the process, it is necessary to analyze the influence of process parameters on the quality of cut. The aim of this paper is to analyze the influence of distance between the cutting head and the working sample on the quality of cut, quantified by the following parameters: width of the processed surface at the jet inlet, jet outlet, deviation from perpendicularity, inclination angle and roughness.

The main context in which abrasive water cutting is used is the reduction of thermal deformation induced by thermal (plasma arc PAC, oxyfuel OFC, laser) of electrothermal (electroerosion EDM) cutting methods. Although it is not the cheapest or time-efficient technique it can be used on a wide variety of metallic and non-metallic materials. Among other benefits are the lack of burrs, high precision and improved surface finish, low setup time and stress-free cutting. This leads to no secondary processing required in many other applications. Depending on the material hardness the cutting thickness can reach up to 300 [mm]. The present study proposes an analysis of high-pressure abrasive water jet cutting of a 19 [mm] thick plate. The aluminium alloy used in this study was Al-6061-T651. This alloy is being used especially in the aeronautics industry due to is excellent welding properties. The experiments were conducted using multiple input and output factors. The design of experiments (DOE) takes into account input factors and offers models for responses. The study was organised according to response surface methodology, with an I-optimal design type and a quadratic design model. The input factors were: cutting pressure, standoff distance, programmed quality of the cut. The responses analysed were: entrance (Iw) and exit (Ow) width of cut, and taper angle (α). An ANOVA analysis was performed for each response. This interpretation implies the significance (p-value) that the input factors have on the variation of the responses. For Iw and Ow a reduced 2FI model was proposed, while for θ a linear model was suggested. The p-value obtained for each response is smaller than 0.0001, which classifies the models as significant. The ANOVA fit statistics determine the R-squared error between 0.964 and 0.995, meaning that the responses are well defined by the input value variations. This high confidence in the results leads to accurate mathematical models.

This paper presents a study concerning the noise level in an enclosure, perceived through the envelope of the building, as a result of the activities carried outside the enclosure. The building chosen for measurements was a teaching laboratory designed for applicative activities and equipped with installations and devices used in laboratory work. To establish the sound pressure level transmitted from outside the building to inside, three types of noise sources were established: a diffuser, a group of people who discuss, and the rainfall intensity on the roof of the enclosure. Measurements were performed both inside and outside the building in different points. The impact on indoor activities due to noise from the outside has been evaluated. The results on the sound pressure level perceived inside the enclosure indicate that the sound pressure level varies depending on the intensity of the outdoor activities.