Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 11 de 11
Filter
Add more filters










Publication year range
1.
Sci Total Environ ; 705: 135940, 2020 Feb 25.
Article in English | MEDLINE | ID: mdl-31846812

ABSTRACT

Sewage sludge is treated by means of cold plasma and stabilization in terms of biological load deactivation is achieved. The plasma is produced by floating electrode dielectric barrier discharge operating with air under atmospheric pressure conditions. The process is presented in detail and the discharge is characterized electrically. Additionally, simulation of the thermal flow inside the process chamber is implemented, using computational fluid dynamics. Deactivation of the serotypes S. Paratyphi B., S. Livingstone, S. Mbandaka and S. Typhimurium, and Escherichia coli and Coliforms, is hereby claimed. The process involves mean electrical power in the range of tens of watts, treatment time in the scale of minutes, and maximum instantaneous temperature <400 K. The present work is a preliminary contribution towards the promotion of advanced methods for the pro-ecological management of biosolids, according to European Regulations.


Subject(s)
Plasma Gases , Sewage , Biosolids , Electricity , Temperature
2.
J Environ Manage ; 195(Pt 2): 186-194, 2017 Jun 15.
Article in English | MEDLINE | ID: mdl-27492877

ABSTRACT

This study investigates the oxidation of municipal wastewater (WW) by complexation with natural polyphenols having radical scavenging activity, such as (3,4,5 tri-hydroxy-benzoic acid) gallic acid (GA) in alkaline pH (>7), under ambient O2 and temperature. Physicochemical and structural characteristics of GA-WW complex-forming are evaluated by UV/Vis spectroscopy. The comparative analysis among UV/Vis spectra of GA monomer, GA-GA polymer, WW compounds, and GA-WW complex reveals significant differences within 350-450 and 500-900 nm. According to attenuated total reflectance (ATR) spectroscopy and thermogravimetric analysis (TGA), these spectra differences correspond to distinct complexes formed. This study suggests a novel role of natural polyphenols on the degradation and humification of wastes.


Subject(s)
Free Radicals/chemistry , Wastewater , Gallic Acid , Oxidation-Reduction , Spectrum Analysis
3.
Langmuir ; 24(8): 3955-9, 2008 Apr 15.
Article in English | MEDLINE | ID: mdl-18324861

ABSTRACT

Adsorption of the insecticide 1-(6-chloro-3-pyridylmethyl)-N-nitroimidazolidin-2-ylideneamine (Imidacloprid) on the hanging mercury drop electrode (HMDE) surface was studied by temperature-dependent stripping voltammetry (TD-SV). At near physiological pH, under reducing conditions, the Gibbs free energy of adsorption, DeltaGADS, shows two distinct temperature-dependent regimes. (a) At 0 degrees < T < 10 degrees C a temperature-independent mechanism occurs with a constant DeltaGADS = -40.5 kJ/mol, resulting in strong chemisorption at high surface coverage. For T < 10 degrees C a considerable enthalpy gain is estimated, and this represents the driving force for the adsorption of Imidacloprid onto the electrode surface. (b) At T > 10 degrees C a temperature-dependent mechanism is operative with DeltaGADS/DeltaT = -91.4 J/K mol, resulting in a rapid weakening of adsorption and low surface coverage. On the basis of the present findings we suggest that the strong chemisorption at T < 10 degrees C at physiological pH under reducing conditions is related to the high specific insecticide activity of Imidacloprid in cool-blooded insects as contrasted to its low efficiency in warm-blooded organisms.


Subject(s)
Hydrophobic and Hydrophilic Interactions , Imidazoles/chemistry , Nitro Compounds/chemistry , Thermodynamics , Adsorption , Chemical Phenomena , Chemistry, Physical , Molecular Structure , Neonicotinoids , Surface Properties , Time Factors
4.
J Phys Chem A ; 109(10): 2223-32, 2005 Mar 17.
Article in English | MEDLINE | ID: mdl-16838994

ABSTRACT

The influence of Pb(II) ions on the properties of the free radicals formed in humic acids and fulvic acids was investigated by electron paramagnetic resonance spectroscopy. It is shown that, in both humic acid and fulvic acid, Pb(II) ions shift the radical formation equilibrium by increasing the concentration of stable radicals. Moreover, in both humic acid and fulvic acid, Pb(II) ions cause a characteristic lowering of the stable radicals' g-values to g = 2.0010, which is below the free electron g-value. This effect is unique for Pb ions and is not observed with other dications. Gallic acid (3,4,5-trihydroxybenzoic acid) and tannic acid are shown to be appropriate models for the free radical properties, i.e., g-values, Pb effect, pH dependence, of humic and fulvic acid, respectively. On the basis of density functional theory calculations for the model system (gallic acid-Pb), the observed characteristic g-value reduction upon Pb binding is attributed to the delocalization of the unpaired spin density onto the Pb atom. The present data reveal a novel environmental role of Pb(II) ions on the formation and stabilization of free radicals in natural organic matter.

5.
Int J Eat Disord ; 25(2): 227-31, 1999 Mar.
Article in English | MEDLINE | ID: mdl-10065401

ABSTRACT

OBJECTIVE: In order to ascertain the most appropriate measure of self-esteem for dieting disordered patients, this study contrasted the construct and convergent validities of two widely used measures. In addition, dieting disordered subgroups were compared on levels of self-esteem. METHOD: One hundred and seventeen male and female patients diagnosed with anorexia nervosa, bulimia nervosa, or eating disorder not otherwise specified completed the Rosenberg Self-Esteem Scale (SES), the Coopersmith Self-Esteem Inventory (SEI), and measures of dieting disorder pathology and depression. RESULTS: No significant differences among the three dieting disorder subgroups were found. In determining convergent validity, regression analyses indicated that the SES was a significant predictor of dieting disorder psychopathology whereas the SEI was not. Of the two self-esteem measures, only the SES showed evidence of convergent validity. DISCUSSION: The results suggest that the SES has sounder construct and convergent validity than the SEI. Hence, the SES may be more appropriate for use with dieting disordered populations.


Subject(s)
Feeding and Eating Disorders/psychology , Psychiatric Status Rating Scales/standards , Self Concept , Adult , Feeding and Eating Disorders/classification , Female , Humans , Male , Prognosis , Reproducibility of Results , Sensitivity and Specificity
7.
J Psychol ; 128(5): 547-58, 1994 Sep.
Article in English | MEDLINE | ID: mdl-7983611

ABSTRACT

We administered a self-report questionnaire to 1,749 adult Australians between 17 and 40 years old to examine the predictive values of self-esteem, depression, locus of control, trait anger, religiosity, psychological reactance, and age in relation to life satisfaction. Results of independent regression analyses showed that all but psychological reactance were significant predictors of life satisfaction. In the stepwise analysis, self-esteem, depression, trait anger, locus of control, and religiosity were significant, and together accounted for 26.3% of the total variance of life satisfaction. In both the stepwise and independent analyses, self-esteem and depression affected levels of satisfaction more than any other variables.


Subject(s)
Personal Satisfaction , Personality , Quality of Life , Adult , Depression , Female , Humans , Internal-External Control , Male , Religion and Psychology , Self Concept , Surveys and Questionnaires
8.
J Soc Psychol ; 134(2): 223-8, 1994 Apr.
Article in English | MEDLINE | ID: mdl-8201818

ABSTRACT

A self-report, attitudinal questionnaire was administered to 1,717 adult Australians between 18 and 40 years old to examine the effects of age and gender on psychological reactance. Analysis yielded a significant age effect: As age increased, the level of reactance tended to decrease. No significant differences in reactance emerged in relation to gender. A significant interaction between age and gender was found.


Subject(s)
Aging/psychology , Defense Mechanisms , Gender Identity , Individuality , Internal-External Control , Adolescent , Adult , Australia , Female , Humans , Male , Personality Inventory
9.
Psychol Rep ; 74(1): 99-103, 1994 Feb.
Article in English | MEDLINE | ID: mdl-8153242

ABSTRACT

Diener, et al.'s 1985 Satisfaction With Life Scale was administered to 1749 adult Australians to examine differences between men and women, university students and nonuniversity students, and among 17- to 22-, 23- to 29-, and 30- to 40-yr.-olds. No significant differences in life-satisfaction emerged in relation to sex or university status, but age showed a significant effect as higher life-satisfaction characterized older subjects. No interactions were found for any combination of the three variables. The results are interpreted in terms of egalitarian sex-role ideologies regarding sex, status-specific criteria in the assessment and conceptualisation of life-satisfaction for university status, and maturity trends in viewing life events concerning age.


Subject(s)
Educational Status , Personal Satisfaction , Quality of Life , Adolescent , Adult , Age Factors , Female , Humans , Male , Personality Inventory , Sex Factors
SELECTION OF CITATIONS
SEARCH DETAIL
...