29 research outputs found
The modernity of the research of Romanian astronomer Constantin Popovici
We present the model of the photogravitational field proposed by the romanian mathematician Constantin Popovici, basic equations. We give the variation of orbital energy in the photogravitational two bodies problem and energy integral. In this case the orbital energy is not conserved
Consideraţii asupra calităţii lucrărilor de afânare adâncă a solului utilizând analiza statistică
The field surveys were conducted within the North-East development region on oderately inclined terrain. The primary data were obtained from the vertical sections of the ground made perpendicular to the forward direction of the soil tiller. The width of the cross-sections was 2 m and the depth of 1.2 m. The primary data obtained from the measurements of the vertical sections made were subsequently processed mathematically. In order to further verify the significance of the differences occurring within a plot, the use of mathematical methods for analyzing the area, volume and shape of the tiled surface has been attempted, which will allow the researcher a larger number of checks under optimal conditionsusing the mathematical statistical apparatus. Key words:deep soil loosening works, soil, statistical analysi
The impact of pig breed on stress levels and meat quality: a study on mangalita purebred and Duroc x Landrace crossbred pigs in Romania
ABSTRACT This study aimed to investigate the impact of pig breed on stress levels and meat quality in two commercial pig farms in the north-eastern part of Romania. One farm raised 52 Mangalita pure-bred pigs and the other 82 Duroc x Landrace crossbred pigs. Serum cortisol, a biomarker of stress, and serum glucose were measured before and after slaughtering, while meat pH was measured at 45 minutes and 24 hours post-mortem. Results showed that the Duroc x Landrace crossbred pigs had higher serum cortisol and glucose values before and after slaughtering compared to the Mangalita purebred pigs. The meat pH values of the two breeds were similar, with the pH45 and pH24 values being 6.67 and 5.48 for Duroc x Landrace crossbred and 6.53 and 5.52 for Mangalita purebred, respectively. These results suggest that pig breed can have an impact on stress levels and meat quality, with Duroc x Landrace crossbred pigs showing higher stress levels and meat quality being not affected by the breed of pig. Further research is needed to confirm these findings and to understand the underlying mechanisms
A Novel Neurotrophic Drug for Cognitive Enhancement and Alzheimer's Disease
Currently, the major drug discovery paradigm for neurodegenerative diseases is based upon high affinity ligands for single disease-specific targets. For Alzheimer's disease (AD), the focus is the amyloid beta peptide (Aß) that mediates familial Alzheimer's disease pathology. However, given that age is the greatest risk factor for AD, we explored an alternative drug discovery scheme that is based upon efficacy in multiple cell culture models of age-associated pathologies rather than exclusively amyloid metabolism. Using this approach, we identified an exceptionally potent, orally active, neurotrophic molecule that facilitates memory in normal rodents, and prevents the loss of synaptic proteins and cognitive decline in a transgenic AD mouse model
Thermal inactivation kinetics of three vegetative bacteria as influenced by combined temperature and pH in a liquid medium
The kinetics of thermal inactivation as affected by combined temperature and liquid pH for three vegetative bacteria— Escherichia coli (ATCC 25922), Listeria monocytogenes (SLCC 5764) and Pseudomonas fluorescens (172)— have been studied using published bench-scale data and additional experimentally determined data from the heating of samples in ampoules of thin-walled glass. These bacteria represent common micro-organisms known to grow in solid and liquid foods. Up to six levels of temperature (52, 54, 56, 58, 60 and 62° C) in combination with up to eight levels of pH (4.0, 4.5, 5.0, 5.5, 6.0, 6.5, 7.0 and 7.5) with exposure times ranging from 10 seconds to five minutes, were used in experimental designs to cover the wide biokinetic range of interest. The carrier liquid, a 2 kg m−3 mucilage of Carbopol® 934 was selected because of the stability of its viscosity over the range of temperature and pH values, and its resistance to bacterial growth. The viscosity of this mucilage closely simulates that of a range of liquid foods. The effect of pH on the rate of thermal inactivation was significant for all three bacteria, especially at the lower exposure temperatures. However, because survivor data showed tailing with longer exposure times, the widely held assumption of first-order kinetics for thermal inactivation of vegetative bacteria is not supported. Concave-up tails appear in the data for P. fluorescens and E. coli and both concave-up and concave-down tails appear in the data for L. monocytogenes. Taken together, data for all three bacteria support the necessity for a model formulation for non-linear survivor kinetics as influenced by combined exposure temperature and liquid pH.J. Chiruta, K.R. Davey and C.J. Thoma
Analysis of spin crossover nanochains using parabolic approximation in the framework of atom–phonon coupling model
International audienc
Determinarea capacitătii antioxidante totale a unor vinuri roşii prin metode electrometrice şi spectrofotometrice
Phenolic compounds from various food matrices can be investigated with
different analytical techniques such as spectrophotometric, cromatographic or
electrochemic methods. Cupric Reducing Antioxidant Capacity method (CUPRAC) is
a convenient assay for determining total antioxidant capacity in food substrates. In
this work, electrochemical and spectrophotometrical approaches were used to
estimate the total antioxidant capacity by means of an alternative of the CUPRAC
assay, as the concentrations of the participating species ([Cu(Nc)2]2+ and
[Cu(Nc)2]1+) can be evaluated by electrochemical and spectrophotometrical methods.
The electrometric–CUPRAC methods have been applied to measure total antioxidant
capacity of different local wines and validated against the spectrophotometric
CUPRAC assay. The electrochemical methods proved to be easy, fast and with low
detection limits. A good correlation for the total antioxidant capacity determined by
CUPRAC spectrofotometric and electrometric method versus total phenol content
(determined by Folin-Ciocalteu Method) was recorded, wich highlights that wines
antioxidant activity results mainly from their phenolics content
Simulations of Edge Effect in 1D Spin Crossover Compounds by Atom-Phonon Coupling Model
5th International Conference on Mathematical Modeling in Physical Sciences (IC-MSquare 2016)International audienceWe used the atom-phonon coupling model to explain and illustrate the behavior of a linear nano-chain of molecules. The analysis of the system’s behavior was performed using Free Energy method, and by applying Monte Carlo Metropolis (MCM) method which take into account the phonon contribution. In particular we tested both the MCM algorithm and the dynamic-matrix method and we expose how the thermal behavior of a 1D spin crossover system varies as a function of different factors. Furthermore we blocked the edge atoms of the chain in its high spin state to study the effect on the system’s behavio