Evaluation of pulmonary and postural functions in patients with chest wall deformity (Pectus carinatum)

Objective: The paper deals with the evaluation of the status of pulmonary and postural functions of the patients with pectus carinatum. Further, it deals with the development of pulmonary and postural functions after Welch surgery. Methods: Between the years 2010 and 2011 20 patients (19 men, 1 woman) went through Welch surgery at the Pediatric Clinic of the Faculty Hospital, Prague Motol. The average age of the group was 16,2 ± 1,2 years. Before surgery, pulmonary functions, respiratory muscle strength and posturography were evaluated. The received values were compared with the predicted, i.e. the controlled group, and in order to find mutual dependencies, also among themselves. 7 patients were repeatedly checked for pulmonary functions and posturography in the interval of 8,1 ± 3,0 months after their surgery. Pre and post - surgery values were compared. Results: Dynamic and static hyperinflation and also an increased patency of periphery respiratory tracts was found in 20 pre-surgery patients with PC. Testing of respiratory muscle strength showed significantly lower values than the predicted. Checking for posturography revealed the differences in postural system resulting, especially with complicated postural demands, in medio-lateral instability of the body. Worsening of the balance functions..

Hydrodynamics characteristics of HDS trickle bed test reactor

AbstractLaboratory-scale trickle bed reactors are often used in testing of catalyst life time and activity. One of the important processes is represented by hydrodesulphurization (HDS) of motor fuels and petrochemical fractions. The study of stability of catalysts activity can be influenced both reactions kinetics, hydrodynamics and mass transfer phenomena. In case of ideal behaviour, the liquid could report piston flow. Non-ideal liquid flow can lead to incomplete catalyst particle wetting, which results in poor utilization of the catalytic surface of the particles. It may also expected to occur stagnant zones and imperfect heat transfer and overheating of the catalytic particles. For limitation of this negative phenomena should be diluted catalytic bed by small inert particle provide more contact area. The aim of this study was to determine degree of the effect of hydrodynamic conditions in model trickle bed reactors by residence time distribution method. Objective was to evaluate liquid holdup, axial dispersion and pressure drop of reactor bed consisting of catalyst particles diluted by inert fines to obtain data for process description by PD mathematical model. Hydrodynamic experiments were carried out in model glasses reactor with I.D 30.4mm. Catalyst –trilobe extrudes of 1.3mm O.D. was diluted by fine grain SiC 0.1-0.15mm to obtained complete catalyst wetting and uniform liquid distribution. In presumed range of liquid and gas flow rates, air and water mass flow corresponded to values of hydrogen and hydrocarbons mixture in high-pressure reactor for the study of HDS catalysts. Gas flow was measured by MFC and liquid flow rate was checked by weighing, pressure drop was measured by pressure probe. Along the bed were located three electrodes to measure conductivity signal of responses to impulse of KCl solution. Data acquisition was made by four channel chromatography Clarity SW/HW, with subsequent evaluation by program in Matlab. Simultaneously, the reproducibility of three bed sections of trickle bed catalyst reactor formation of bed diluted by fines was tested by two methods. Effective mean residence time, liquid holdup and axial dispersion were evaluated for each. The range of experimental operation conditions (gas and liquid flow rates) negligible influenced by hydrodynamics was evaluated both experimentally and by hydrodynamics PD model

Hydrocracking of Heavy Vacuum Gas Oil with Petroleum Wax

Petroleum heavy vacuum gas oil (HVGO) containing 10 wt.% of petroleum wax was hydrocracked at 390–430 °C and under the pressure of 18 MPa over a Ni W/amorphous silica-alumina catalyst in a continuous-flow fixed-bed reactor. The hydrocracking of a reference feed (neat HVGO) was carried out under the same reaction conditions. The physico-chemical properties of primary products obtained via laboratory atmospheric-vacuum distillation (heavy naphtha, middle distillates and distillation residue) were evaluated. Most products prepared from the mixed feedstock had a similar or lower density and sulfur content than the products obtained from the hydrocracking of the neat HVGO. The heavy naphtha fractions obtained from mixed feedstock contained slightly more n-alkanes and iso-alkanes and less naphthenes and aromatics. Similarly, middle distillates obtained from the mixed feedstock contained slightly more n-alkanes and less aromatics and had cetane index higher by up to 2 units

Hydrocracking of Heavy Vacuum Gas Oil with Petroleum Wax

Petroleum heavy vacuum gas oil (HVGO) containing 10 wt.% of petroleum wax was hydrocracked at 390–430 °C and under the pressure of 18 MPa over a Ni W/amorphous silica-alumina catalyst in a continuous-flow fixed-bed reactor. The hydrocracking of a reference feed (neat HVGO) was carried out under the same reaction conditions. The physico-chemical properties of primary products obtained via laboratory atmospheric-vacuum distillation (heavy naphtha, middle distillates and distillation residue) were evaluated. Most products prepared from the mixed feedstock had a similar or lower density and sulfur content than the products obtained from the hydrocracking of the neat HVGO. The heavy naphtha fractions obtained from mixed feedstock contained slightly more n-alkanes and iso-alkanes and less naphthenes and aromatics. Similarly, middle distillates obtained from the mixed feedstock contained slightly more n-alkanes and less aromatics and had cetane index higher by up to 2 units