Analele Universităţii "Dunărea de Jos" din Galaţi. Fascicula XIV, Inginerie mecanică = Annals of “Dunarea de Jos“ University of Galati. Fascicle XIV, Mechanical Engineering

ASSESSMENT OF THE IMPACT OF CLIMATE CHANGE ON THE ECOSYSTEM OF BALTA ALBĂ LAKE, BUZĂU COUNTY

2026-01-19T11:28:25+02:00

This study provides data on the impact of climate change on the Balta Albă Buzău natural reserve. Lake Amara, as part of the reserve, dried up first, followed by Balta Albă Lake, which now contains a reduced amount of water; in certain years, the water has receded tens of meters from its former shores. The lake is nationally and internationally recognized for the health benefits of its mineralized waters and sapropelic muds, which constitute the biotope of this lake. The present paper presents a study of the physical-chemical quality indicators of the water and mud from Balta Albă Lake, Buzău County. Experimental analyses were performed for the following physical-chemical parameters: pH, dissolved salts, and the content of calcium, magnesium, chlorides, and sulfates. The research aims to assess the influence of the significant water retreat on the mineral content of the lake’s water and mud, the lake being renowned for over 200 years for its curative properties for various conditions.

VALORIZATION OF LIVESTOCK MANURE AS A MEANS OF ENVIRONMENTAL PROTECTION IN RURAL REGIONS

2026-01-19T11:29:16+02:00

The study was conducted both to highlight the negative environmental impacts associated with livestock manure and to assess the potential use of manure as a sustainable alternative to chemical fertilizers. To this end, three distinct samples of cattle manure at different stages of fermentation were collected. The main physico-chemical quality parameters analyzed were: pH, moisture content, organic matter, salt content, nitrate and ammoniacal nitrogen, phosphates, and potassium. Livestock manure represents a major source of pollution in rural areas, potentially causing diseases in animals and humans and contributing to the increase of the carbon footprint if storage regulations are not properly followed prior to its use as fertilizer. This research aims to determine the nutritional quality of the studied manure in order to evaluate its applicability as agricultural soil amendment.

STUDY OF THE PENDULAR MOTIONS OF THE FORESTRY GRAPPLE

2026-01-19T11:29:55+02:00

In this paper, an analysis of the dynamics of the technological work processes of forestry grapples was carried out. The purpose of the paper is to highlight the dynamic effects of shock-type actions on the movement of the loaded grapple. Several constructive grapples variants were proposed and the influence of the position of the center of mass on the oscillations of the working tool in perpendicular planes was analyzed. The simulation of the movements was performed in the Matlab environment and the rotation velocities diagrams for both slewing and swaying motions of the grapple were obtained, for sudden commands performed by a less experienced operator. The results will form the basis for developing a solution for reducing the amplitudes of these movements, to improve the stability of the grapple in the working process.

VIBRATION ANALYSIS OF ROLLING BEARINGS

2026-01-19T11:30:36+02:00

Machine failures in modern industry led to decreased production and reduced competitiveness. Bearings are important parts in machine construction and their operation has a significant impact on the function and lifespan of the machine as a whole. Vibration measurement is the main non-invasive method for locating and predicting failures of rotating machinery components. The paper details using
vibration analysis, specifically Power Spectral Density (PSD) analysis of acceleration signals from a bearing's damaged inner race, as a cost-effective and reliable method to diagnose bearing failures. This technique identifies deviations from normal vibration patterns in rotating equipment, helping to predict and
prevent potential failures.

CONSIDERATIONS REGARDING ELECTROMAGNETIC RADIATION POLLUTION GENERATED BY OFFICE COMPUTERS

2026-01-19T11:31:12+02:00

Considering the potential negative effects of the exposure of the human body to electromagnetic fields, it is necessary to experimentally determine their parameters and compare them with the limit values provided by the regulations. The paper presents an introduction to the issue of electromagnetic pollution, followed by a case study on the evaluation of the parameters of the electromagnetic field generated by office computers in a public institution. The study was based on measurements made in two rooms belonging to a higher education institution, and based on the data obtained, maps of the electromagnetic fields corresponding to the operation of computers were drawn up, to identify any exceedances of the admitted limits. Following the analyses, areas where the electric field parameters exceeded the permissible limits were identified, and remedial measures were proposed for these areas.