Preferencje help
Widoczny [Schowaj] Abstrakt
Liczba wyników

Znaleziono wyników: 6

Liczba wyników na stronie
first rewind previous Strona / 1 next fast forward last
Wyniki wyszukiwania
help Sortuj według:

help Ogranicz wyniki do:
first rewind previous Strona / 1 next fast forward last
EN
The paper deals with the variation of the kappa number, lignin and hexenuronic acid content of the washed and unwashed spruce kraft pulp. The displacement washing was carried out with the spruce kraft pulp having seven level kappa number. It was notice able that the depletion of lignin content after washing depend supon the kappa number of the pulp. The most variation was found in the Klason lignin content of the pulp. The leaching of lignin was least for the pulp with the lowest kappa number. Hexenuronic acid composition of the unwashed pulp was hardly affected by the displacement washing.
PL
W artykule opisano wahania liczby kappa, zawartości ligniny i kwasu heksenuronowego przed i po myciu masy siarczanowej z drewna świerkowego. Mycie wyporowe zastosowano do masy siarczanowej świerkowej o siedmiu poziomach liczby kappa. Zaobserwowano, że spadek zawartości ligniny po myciu zależy od liczby kappa masy. Największe zmiany zaobserwowano w przypadku zawartości w masie ligniny Klasona. Wymywanie ligniny było najmniejsze w przypadku maso najniższej liczbie kappa. Mycie wyporowe miało znaczący wpływ na skład kwasu heksenuronowego w mytej masie.
EN
On machine measurement of artefacts such as single ball, multiple balls or even prismatic shape artefact is gaining popularity for the calibration of five-axis machine tools. However, calibration results can be degraded due to errors from different process variables such as the measurement strategies, rotary axes indexations and artefact dismount and remount cycles. This research investigates the repeatability of uncalibrated indigenous artefact probing and machine tool error parameters calibration against a number of process variables. Uncertainties of the estimated parameters are estimated to quantify the calibration quality.
EN
The touch trigger probe plays an important role in modern metrology because of its robust and compact design with crash protection, long life and excellent repeatability. Aside from coordinate measuring machines (CMM), touch trigger probes are used for workpiece location on a machine tool and for the accuracy assessment of the machine tools. As a result, the accuracy of the measurement is a matter of interest to the users. The touch trigger probe itself as well as the measuring surface, the machine tool, measuring environment etc. contribute to measurement inaccuracies. The paper presents the effect of surface irregularities, surface wetness due to cutting fluid and probing direction on probing accuracy on a machine tool.
PL
Elektrostykowe sondy przełączające grają istotną rolę we współczesnej metrologii z uwagi na ich zwartą i silną konstrukcję, odporność na uszkodzenia, długowieczność i doskonałą powtarzalność. Obok zastosowań we współrzędnościowych maszynach pomiarowych (CMM), sondy te są wykorzystywane do wyznaczenia położenia przedmiotu obrabianego na obrabiarce i oceny dokładności obrabiarek. Tak więc, dokładność pomiaru jest sprawą istotną dla użytkowników. Do powstawania niedokładności pomiaru przyczynia się sama sonda, a także powierzchnia pomiarowa, obrabiarka, środowisko pomiarowe itp. W artykule przedstawiono wpływ nierówności powierzchni, wilgotności powierzchni powodowanej obecnością chłodziwa i kierunku sondowania na dokładność pomiaru na obrabiarce.
EN
To increase the profitability of the pulp and paper industry, additional value added products from lignocelluloses are needed, and consistent with this goal, a biorefinery concept based on the sodium carbonate pre-extraction of Trema orientalis prior to pulping was proposed. The solid content in the sodium carbonate pre-extracted liquor was much lower than the hot water pre-extraction, which affected the pre-hydrolysis yield and overall pulp yield positively. The alkaline pre-extraction had a beneficial effect on delignification in the subsequent soda-AQ-pulping. In addition, the alkaline pre-extraction improved the pulp bleachability. The papermaking properties of the alkaline pre-extracted soda-AQ pulp were very close to non-extracted pulp after D0EpD1 bleaching.
EN
The adsorption of a reactive dye (Procion Red) from aqueous solution onto activated carbon was investigated. The effect of contact time, pH, adsorbent dosage and temperature were studied. The equilibrium data were described well by both Langmuir and Freundlich isotherm model. The adsorption kinetics was tested for pseudo-first-order, pseudo-sec - ond order, intraparticle diffusion and unified approach kinetic models. The unified approach model de scribed the kinetic data in accor dance with the experimental data and the forward and backward rate constants were evaluated from the model fittings. The adsorption is highly pH dependent and adsorption efficiency in creases with the decrease in pH. Thermodynamic parameters of the adsorption process suggested that the process was endothermic. The adsorption capacity of regenerated activated carbon showed more than 70 percent recovery of the adsorption efficiency of the initial virgin adsorbent.
EN
An unsteady convective flow and heat transfer of a micropolar fluid past a continuously moving verticaI porous plate with time dependent suction and in the presence of radiation has been analyzed numericaIly. With appropriate transformations the boundary layer equations are transformed into a set of nonlinear ordinary differentiaI equations. The locaI similarity solutions in time of the transformed dimensionless equations for the flow, microrotation and the heat transfer characteristics are evaIuated using the Nachtsheim-Swigert shooting iteration technique. NumericaI results are presented in the form of velocity, microrotation and temperature profiles within the boundary layer for different parameters entering into the analysis. FinaIly, the skin friction coefficient and rate of heat transfer are tabulated for the pertinent parameters.
first rewind previous Strona / 1 next fast forward last
JavaScript jest wyłączony w Twojej przeglądarce internetowej. Włącz go, a następnie odśwież stronę, aby móc w pełni z niej korzystać.