Variation in contents of total and soluble nitrogen i e. coefficient of ripeness in beaten cheese during ripening and keeping in brine

U radu je opisana dinamika sadržaja ukupnog i topivog dušika, odnosno koeficijenta zrelosti u autohtonom makedonskom bienom siru. Dinamika navedenih komponenata praćena je u toku zrenja i čuvanja sira u salamuri u toku 279 dana. Rezultati analiza pokazuju da se ukupne količine dušika kreću od 6,21-6,91, a topivog dušika od 0,277-0,824 g na 100 g suhe supstance sira. Koeficijent zrelosti kreće se od 4,00-12,85. Podaci ukazuju da se vrijednosti topivog dušika, odnosno koeficijenta zrelosti znatno mijenjaju, dok ukupne vrijednosti dušika do kraja istraživanja nisu pokazale velike promjene.Dynamics of total and soluble nitrogen contents i.e. coefficient of ripening of autochthonous Macedonian beaten cheese were studied during 279 days of ripening and keeping cheese in brine. According to analytical data quantity of total nitrogen ranges from 6.21-6.91 g soluble nitrogen from 0.277-0.824 g calculated on 100 g of total solids of cheese. Coefficient of ripening ranges from 4.00-12.85%. Data indicate considerably changes in values of ripening coefficient, but values of total nitrogen do not change considerably up to the end of investigation

An Architecture for Computer-Aided Detection and Radiologic Measurement of Lung Nodules in Clinical Trials

Computer tomography (CT) imaging plays an important role in cancer detection and quantitative assessment in clinical trials. High-resolution imaging studies on large cohorts of patients generate vast data sets, which are infeasible to analyze through manual interpretation

Persistence on therapy and propensity matched outcome comparison of two subcutaneous interferon beta 1a dosages for multiple sclerosis

To compare treatment persistence between two dosages of interferon β-1a in a large observational multiple sclerosis registry and assess disease outcomes of first line MS treatment at these dosages using propensity scoring to adjust for baseline imbalance in disease characteristics. Treatment discontinuations were evaluated in all patients within the MSBase registry who commenced interferon β-1a SC thrice weekly (n = 4678). Furthermore, we assessed 2-year clinical outcomes in 1220 patients treated with interferon β-1a in either dosage (22 µg or 44 µg) as their first disease modifying agent, matched on propensity score calculated from pre-treatment demographic and clinical variables. A subgroup analysis was performed on 456 matched patients who also had baseline MRI variables recorded. Overall, 4054 treatment discontinuations were recorded in 3059 patients. The patients receiving the lower interferon dosage were more likely to discontinue treatment than those with the higher dosage (25% vs. 20% annual probability of discontinuation, respectively). This was seen in discontinuations with reasons recorded as “lack of efficacy” (3.3% vs. 1.7%), “scheduled stop” (2.2% vs. 1.3%) or without the reason recorded (16.7% vs. 13.3% annual discontinuation rate, 22 µg vs. 44 µg dosage, respectively). Propensity score was determined by treating centre and disability (score without MRI parameters) or centre, sex and number of contrast-enhancing lesions (score including MRI parameters). No differences in clinical outcomes at two years (relapse rate, time relapse-free and disability) were observed between the matched patients treated with either of the interferon dosages. Treatment discontinuations were more common in interferon β-1a 22 µg SC thrice weekly. However, 2-year clinical outcomes did not differ between patients receiving the different dosages, thus replicating in a registry dataset derived from “real-world” database the results of the pivotal randomised trial. Propensity score matching effectively minimised baseline covariate imbalance between two directly compared sub-populations from a large observational registry

Scaling Parameters for Dynamic Diffusion-Reaction over Porous Catalysts

The effect of diffusion resistance in porous solid catalysts on reaction rate during periodic cycling of CO concentration is shown for CO oxidation over Pt/Al2O3 by numerical simulation. At some cycling frequencies, the average reaction rate during cycling is higher than the steady-state rate at the mean CO concentration, as expected for this nonlinear, reactant-inhibited reaction. In order to identify major aspects of dynamic diffusion-reaction behavior, a simple kinetic mechanism that shows the main features of CO oxidation and other reactions with significant inhibition by reactants is investigated. A single dimensionless parameter group, the dynamic diffusion coefficient, is added when going from steady-state to unsteady-state diffusion-reaction equations. In the dynamic diffusion coefficient, the rate at which the gas-phase reactant diffuses is reduced by the surface adsorption capacity of the catalyst. The frequency at which the peak average rate occurs is controlled by the dynamic diffusion coefficient

Nonlinear frequency response of a chromatographic column. part I: Application to estimation of adsorption isotherms with inflection points

A new method to determine adsorption isotherms is suggested. The method is based on analysis of the nonlinear frequency response of a chromatographic column. Due to the fact that higher order frequency response functions (FRTs) are included in the analysis, the method is in particular useful to determine isotherms with more complex shapes, e.g., isotherms possessing inflection points. By theoretical derivation of the first-, second-, and third-order FRFs and their analysis, it is shown that the first, second, and third derivatives of the corresponding adsorption isotherm can be estimated from the low frequency asymptotes. The analysis presented is made for the adsorption of a single component. The description of the chromatographic column is based on the equilibrium-dispersion model. The extension of the method considering the possibility of a finite mass transfer rate in the column is also presented

Evaluation of periodic operation of a trickle-bed reactor based on empirical modeling

In this paper, we propose a new procedure for fast evaluation of the potential of periodic operations in trickle-bed reactors, based on empirical modeling. Step response experiments, with different input amplitudes, were performed on a laboratory trickle-bed reactor, in order to derive a simple nonlinear dynamic model. a-methylstyrene (AMS) hydrogenation was used as a test reaction and the feed AMS concentration was used as the modulated input. An empirical nonlinear model was postulated and used for simulation of periodic operations. The simulation of a periodic operation with sinusoidal modulation of the inlet AMS concentration with 40 % amplitude resulted up to 35% higher time-averaged conversion than the corresponding steady-state one

Nonlinear Frequency Response Analysis of the Ferrocyanide Oxidation Kinetics. Part I. A Theoretical Analysis

In this work, a nonlinear frequency response (NLFR) analysis was used for a first time in a theoretical study of nonlinear behavior of electrochemical (EC) ferrocyanide oxidation as a simple model reaction. Analytical expressions of the first- and second-order frequency response functions (FRFs) are derived. The first-order FRF is equivalent to the EC admittance and contains information about the linear behavior of the system, whereas the second-order FRF contains additional nonlinear information. The influence of different parameters, such as the heterogeneous rate constant, solution resistance, double-layer capacitance, diffusion coefficients of the reacting species, and electrode rotation rate on the characteristics of the first- and second-order FRFs was checked and discussed. It was found that the second-order FRF is more sensitive to the changes of the studied parameters than the first-order FRF. Experimental verification of the NLFR analysis of EC ferrocyanide oxidation is presented in Part II of this wor