EVALUATION OF THE REVERBERATION TIME IMPROVEMENT IN A SPEAKING HALL

To improve a room's acoustic parameters there have been studied several variants of acoustic materials and devices that can be placed on the ceiling of the hall. The main objective of the study was the reverberation time measurement and calculation. By using the acoustic panel made from polystyrene, covered with jute on the both sides, has ensured the largest reverberation time decrease. Thus, we can say that the analyzed room can be used for speech activity (courses, conferences etc.

EVALUATION OF THE REVERBERATION TIME IMPROVEMENT IN A SPEAKING HALL

To improve a room's acoustic parameters there have been studied several variants of acoustic materials and devices that can be placed on the ceiling of the hall. The main objective of the study was the reverberation time measurement and calculation. By using the acoustic panel made from polystyrene, covered with jute on the both sides, has ensured the largest reverberation time decrease. Thus, we can say that the analyzed room can be used for speech activity (courses, conferences etc.

EVALUATION OF THE AMMONIA AIR POLLUTION AND CLIMATIC FACTORS INTERACTIONS, CASE STUDY 2008 BACAU CITY ROMANIA

Atmospheric pollution present interest for monitoring and analysis when one or more substances or mixture of pollutants are present in the atmosphere in quantities or for a period that can be dangerous for humans, animals or plants and contribute to endangering the activity or welfare of persons. The present research was aimed to establish a link between meteorological factors (temperature, wind, atmospherically humidity, solar radiation, air pressure) and the ammonia air pollutant. Particularities of research methodology consisted in establishing a connection between meteorological factors in Bacau area and its air quality, taking into account both direct and inverse effects induced by geographical complexity and economic activities. The correlations between ammonia air pollution and analyzed climatic factors variation were realized by graphical interpretations and observing the appropriate links of dependency. In one of the case (2008.08.20) a better dispersion of pollutants occurs in the case of sunshine duration over a longer period, without or with low nebulosity

EVALUATION OF THE AMMONIA AIR POLLUTION AND CLIMATIC FACTORS INTERACTIONS, CASE STUDY 2008 BACAU CITY ROMANIA

Atmospheric pollution present interest for monitoring and analysis when one or more substances or mixture of pollutants are present in the atmosphere in quantities or for a period that can be dangerous for humans, animals or plants and contribute to endangering the activity or welfare of persons. The present research was aimed to establish a link between meteorological factors (temperature, wind, atmospherically humidity, solar radiation, air pressure) and the ammonia air pollutant. Particularities of research methodology consisted in establishing a connection between meteorological factors in Bacau area and its air quality, taking into account both direct and inverse effects induced by geographical complexity and economic activities. The correlations between ammonia air pollution and analyzed climatic factors variation were realized by graphical interpretations and observing the appropriate links of dependency. In one of the case (2008.08.20) a better dispersion of pollutants occurs in the case of sunshine duration over a longer period, without or with low nebulosity

DETERMINATION OF THE REAL VALUES OF KINEMATIC INDEX CORRESPONDING TO THE MECHANICAL SEPARATION PROCESS

This article presents the methodology for determining the real values of kinematic indices which characterizes the mechanical separation of a mixture of solid particles. Mechanical separation of a mixture of solid-solid on surface provided with holes is the most common method of separation. To optimize equipment that performs this operation, both theoretical and practical characteristics are determined. Kinematic indices are part of the theoretical characteristics, helping to identify behavior of solid particles on a surface flat swing. Starting from an experimental batch, real values of the kinematic indices corresponding to up, down and sideways movement on the sieve were determined for the following types of real particles: grain, large grain beans, small grain beans and soybeans

DETERMINATION OF THE REAL VALUES OF KINEMATIC INDEX CORRESPONDING TO THE MECHANICAL SEPARATION PROCESS

This article presents the methodology for determining the real values of kinematic indices which characterizes the mechanical separation of a mixture of solid particles. Mechanical separation of a mixture of solid-solid on surface provided with holes is the most common method of separation. To optimize equipment that performs this operation, both theoretical and practical characteristics are determined. Kinematic indices are part of the theoretical characteristics, helping to identify behavior of solid particles on a surface flat swing. Starting from an experimental batch, real values of the kinematic indices corresponding to up, down and sideways movement on the sieve were determined for the following types of real particles: grain, large grain beans, small grain beans and soybeans

Hazardous Waste Advanced Management in a Selected Region of Poland

This article presents a study on hazardous waste management in the Malopolskie region of Poland. The study was based on the information obtained during three years from 2016 to 2018, and following analysis, it was found that in 2016 there was the highest amount of 24,872.13 tons of hazardous waste produced, of which only a three-fold lower amount was disposed of. In this study, various types of hazardous waste were analyzed, including the waste from construction materials and asbestos. The predominant share of 50% of the mass of analyzed hazardous waste was felt on the generated one. Waste recovered in installations had a lower share of 43%, with a significant and favorable increase of over 5000.00 tons. In the context of the correctness of environmental aspects, it was considered an advisable solution that would optimize treatment conditions, and at the same time minimize the costs of hazardous waste management

EXPLOITATION OF ORGANIC ULTRAFILTRATION MEMBRANES IN THE REMOVAL OF PEPTONE FROM WASTEWATER

In the present paper an ultrafiltration experiment was carried out for testing the polyacrylonitrile (PAN) membrane in the process of peptone separation from wastewater. The evaluation of the applied ultrafiltration process consisted in the monitoring and the recording of the parameters as well as of some indicators that will reveal the PAN membrane efficiency (the percentage of peptone retention on the membrane surface, the volume and quality of the resulting permeate in the pre-established time period). The obtained results showed that the peptone retention efficiency was noticeably, around 20 % and the obtained permeate volume did not decrease greatly, only by 2.5 L over 300 minutes experiment

Assessment of Cadmium and Copper Adsorption by Two Agricultural Soils from Romania and Tunisia: Risk of Water Resource Pollution

Using treated wastewater for irrigation is a good solution for conserving water, but it is also in part responsible for groundwater and water surface pollution by heavy metals, especially copper and cadmium. The soil can be a barrier to retaining these pollutants and protecting the water resource. This study presents an assessment of the adsorption of copper and cadmium by two agricultural soils from Tunisia and Romania to evaluate the risk of water pollution. At first, the two soils were characterized with a scanning electron microscope and different physico-chemical analyses. Before adsorption, the elemental analysis performed with an SEM showed a very low amount of cadmium and copper in both soils (0.01%). The Tunisian soil was considered clayey soil, and the Romanian soil was sandy clayey soil. All experimental kinetics and isotherms were well correlated (R2 > 0.9) with the pseudo-first-order kinetic model and the modified and extended Redlich–Peterson binary adsorption model. For an initial concentration of both pollutants of 0.1 mmol·L−1, the amounts retained and the adsorption percentage of copper and cadmium by the two soils indicate that the Romanian soil (qCu = 0.87 μmol·g−1; % Cu = 98%; qCd = 0.88 μmol·L−1; % Cd = 99%) retained both pollutants better than the Tunisian soil (qCu = 0.65 μmol·g−1, %Cu = 83%; qCd = 0.73 μmol·g−1; %Cd = 93%). Copper presents the greatest risk of water resource pollution, especially in Tunisia. The SEM confirmed the soil adsorption of Cu and Cd and estimated that the retention mechanisms of these two heavy metals are mainly related to the amount of phosphorus, chloride, sulfur and carbon by complexation and precipitation reactions

ANALYSIS OF WATER QUALITY FOR TWO RIVERS LOCATED NEAR A MINING AREA

The paper presents a study that was focused on the analysis of the existence of metals in the rivers located near the salt mine Targu Ocna, Romania. The points identified near mining areas and the proposal for performing analyzes regarding the presence of metals in surface waters are the Slanic River and the Trotus River. The purpose of this study is to analyze the physico-chemical parameters: (pH, electrical conductivity, dissolved oxygen, turbidity, temperature), selected heavy metals (Fe, Mn, Zn, Cr), Mg and Al of the Slanic River and the Trotus River located near the salt mine and to investigate the level of metal contamination due to mining activities. The samples were collected at two points in the Slanic River and two points for the Trotus River. The physico-chemical parameters were measured in-situ with portable equipment and within the Water Analysis Laboratory of “Vasile Alecsandri” University of Bacau. The values registered for the physico-chemical parameters were compared with the permissible limits by the legislation