12 research outputs found
ON THE PHOTOLUMINESCENCE AND OPTICAL PROPERTIES OF ZINC OXIDE THIN FILMS PREPARED BY THERMAL OXIDATION
Zinc oxide (ZnO) thin films were prepared by thermal oxidation of vacuum evaporated metallic zinc films. Some structural investigation, performed by X-ray diffraction technique, showed that films are polycrystalline and have a würtzite structure. We also determined some structural parameters of the films. The optical absorption was studied in the wavelength range from 300 nm to 1700 nm. Photoluminescence spectra at temperatures 293 K and 78 K have been analysed
ON THE PHOTOLUMINESCENCE AND OPTICAL PROPERTIES OF ZINC OXIDE THIN FILMS PREPARED BY THERMAL OXIDATION
Zinc oxide (ZnO) thin films were prepared by thermal oxidation of vacuum evaporated metallic zinc films. Some structural investigation, performed by X-ray diffraction technique, showed that films are polycrystalline and have a würtzite structure. We also determined some structural parameters of the films. The optical absorption was studied in the wavelength range from 300 nm to 1700 nm. Photoluminescence spectra at temperatures 293 K and 78 K have been analysed
THE PRODUCTION CAPACITY OF LEACHATE COLECTED FROM PIATRA NEAMT LANDFILL
Lately it was seen an growth and range broadening of activities in all sectors of economy and society and therefore, the management of waste is a problem facing the entire planet. This paper purpose an analysis of a Romanian Landfill, concerning leachate production. Mathematical models applied on landfill products create an environmental background in which concerns waste management in Romania
THE PRODUCTION CAPACITY OF LEACHATE COLECTED FROM PIATRA NEAMT LANDFILL
Lately it was seen an growth and range broadening of activities in all sectors of economy and society and therefore, the management of waste is a problem facing the entire planet. This paper purpose an analysis of a Romanian Landfill, concerning leachate production. Mathematical models applied on landfill products create an environmental background in which concerns waste management in Romania
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
Fractographic and Microhardness Evaluation of All-Ceramic Hot-Pressed and CAD/CAM Restorations after Hydrothermal Aging
All-ceramic dental restorations have great advantages, such as highly esthetical properties, a less complex fabrication, and a similar abrasion resistance to enamel. Despite these advantages, ceramic materials are more prone to fracture due to their brittle microstructure. The main aim of this in vitro study was to determine the difference in hot-pressed and milled glass-ceramic mechanical properties such as fracture resistance and microhardness (VHN). Four types of ceramics, two hot-pressed and two milled, feldspathic glass-ceramics and zirconia-reinforced glass-ceramics were selected in this study and tested using the static loading test and Vicker’s testing. Hydrothermal aging, consisting of different baths with temperatures between 5 degrees Celsius and 55 degrees Celsius, was chosen as the in vitro aging method. Statistical analyses are performed using SPSS Statistics software at a significance level of p < 0.05. Micro-hardness values decrease after hydrothermal aging. The static loading test reveals a significant difference between the feldspathic hot-pressed glass-ceramic, which fractures at lower forces, and milled zirconia-reinforced lithium silicate glass-ceramic, which fractures at greater forces (N). Fractographic analysis of the fractured fragments resulted in the static loading test revealing different surface features about the crack origins and propagations under a stereomicroscope
Microbiological Assessment of Broiler Compound Feed Production as Part of the Food Chain—A Case Study in a Romanian Feed Mill
Compound feed and the raw materials used in their production are potential vectors of microbiological contamination in the food chain. The purpose of this study was to microbiologically asses raw materials (maize, wheat, soybean meal, and sunflower meal), and broiler compound feed (starter, grower, and finisher) from a representative feed mill in Romania; the microbiological contaminants that were analyzed were yeasts and molds, Salmonella spp., Escherichia coli, and Clostridium perfringens. Our study occured during the years 2019 and 2020; in 2019, 191 samples of raw materials and 360 samples of compound feed were analyzed and in 2020, 143 samples of raw materials and 241 samples of compound feed were analzyed. Among the tested samples of raw materials, the mean values of the yeasts and molds for maize, wheat, soybean, and sunflower meal were 1.3 × 103, 9.5 × 102, 6.4 × 102, and 7.4 × 102 cfu/g in 2019 and 1.5 × 103, 1.0 × 103, 5.2 × 102, and 7.1 × 102 cfu/g in 2020. In the analyzed compound feed samples, the mean amounts for the starter, grower, and finisher were 5.9 × 102, 4.2 × 102, and 4.2 × 102 cfu/g in 2019 and 5.3 × 102, 6.5 × 102, and 5.8 × 102 cfu/g in 2020. Potentially toxigenic fungi from Aspergillus, Penicillium, and Fusarium genera have been identified as the most common in all of the samples. In the raw materials, in both years the highest numbers of Aspergillus-positive samples were recorded: 66.6% in 2019 and 100% in 2020 for the maize samples, 50% in 2019 and 75% in 2020 for the wheat samples, 76% in 2019 and 87.5% in 2020 for the soybean meal samples and 71.4% in 2019 and 100% in 2020 for the sunflower meal. In the starter compound feed, the Aspergillus genera was prevailing in 2019 (46.6%), while in 2020, the species of the Penicillium and Cladosporium genera were identified in the majority of the samples (50%); for the grower and finisher compound feed, the Aspergillus genera was predominantly identified in 2019 (60% and 72.2% of the samples, respectively) and 2020 (61.5% and 46.6%, respectively). All of the results of the bacteriological analysis for determining the contamination with Salmonella spp., E. coli, and Clostridium perfringens were negative. Based on the results obtained in this study, monitoring and analysis of microbiological hazards in a feed mill will help to control and prevent contamination and have a direct impact on food safety
iJobs – An online implementation of the JOBS II program for fostering reemployment: A feasibility and acceptability study
The current study aimed to test the feasibility and acceptability of iJobs, an online adaptation of the JOBS II program (Curran et al., 1999). iJobs is a two-week internet intervention for the unemployed, consisting of five modules. This study is an open-label trial with an uncontrolled, within-group, pre-posttest, and follow-up design. Out of the 56 participants allocated to the intervention, 36 completed (Mage = 25 years; 57.1 % females) the post-test (36 % dropout), and 34 the three months follow-up. The protocol-compliant participants followed the modules with great engagement (mean quality of assignments completion above 4 points out of 5 for each module). The online platform's usability was high (84.86 points out of 100). Participants reported high overall satisfaction with the program. Our results suggest that iJobs is a feasible intervention and was accepted by its beneficiaries. Relative to baseline, inoculation against setbacks (d = 0.64), job search self-efficacy (d = 0.50), and self-esteem (d = 0.28) increased significantly, while future career anxiety in the COVID-19 context decreased significantly (d = 0.34). No significant differences were found for depression, anxiety, and job-search behaviors. At three months follow-up, 55.9 % of the participants found employment, 5.9 % were in a job selection process, and 38.2 % were still unemployed. Job satisfaction was high among the employed