Wyniki wyszukiwania - BazTech

1

Preparation and characterization of low density polyethylene nanocomposites with modified montmorillonite clay

Nour M., Elgazery M., Awad W., Amer M.

Polimery

|

2009

|

T. 54, nr 7-8

536-540

EN

Organically modified montmorillonite clay (OMC) and its iron complex (OMC-Fe) were prepared using 1-acetylpyridinium chloride salicylhydrazone. Low density polyethylene (PE-LD) was compounded with either OMC or OMC-Fe (in amount of 3 or 7 wt. %) using ultrasonic radiation. The morphology of polyethylene composites was characterized by atomic force microscopy (AFM). The thermal stability and flammability properties of polyethylene composites were evaluated using thermogravimetric analysis and cone calorimetry, respectively. The resultant composites exhibited improved flammability relative to the pure polyethylene.

PL

Montmorylonit (MMT) modyfikowano za pomocą surfaktantu (H2ACSH). Z części uzyskanej organicznie modyfikowanej glinki montmorylonitoej (OMC) otrzymywano jej kompleks z kationami żelaza (III) (OMC-Fe). Następnie używając fal ultradźwiękowych przygotowano nanokompozyty polietylenu małej gęstości (PE-LD) z OMC lub OMC-Fe w ilości 3 lub 7 % mas. Metodą mikroskopii sił atomowych (AEM) wykonano charakterystykę morfologiczną próbek nanokompozytów. Stabilność termiczną tych próbek zbadano metodą analizy termograwimetrycznej, a palność za pomocą kalorymetru stożkowego. Stwierdzono, że dodatek OMC lub OMC-Fe do PE-LD praktycznie nie wpływa na stabilność termiczną nanokompozytów w porównaniu z czystym PE-LD, ale zmniejsza ich palność.

2

Evaluation of CMM for flatness measurements

Sidki H. M., Amer M.

Metrology and Measurement Systems

|

2008

|

Vol. 15, nr 4

585-593

EN

Coordinate measuring machine (CMM) is a universal measuring instrument in dimensional metrology. However, the CMM has many sources of errors and deviations that affect its precision and accuracy. Unfortunately, the accuracy of flatness measurement by the CMM is not studied which is very important feature in metrology and industry at present time. A method is introduced to evaluate the accuracy of the flatness measurement of the Zeiss CMM based on flatness measurement of an optical flat. The flatnesses of the optical flat are measured by four different techniques using the CMM. Moreover, the effects of CMM head probe's scanning speed and step width on flatness measurements are examined separately in special measuring subroutines. The flatness of the optical flat surfaces are calibrated using Zygo phase shifting interferometer since it is used as reference for this study. The experimental results show that the CMM's probing points technique can be used for accurate measurements of flatness.

3

Calibration of reference standard quartz rotating plates

Sidki H. M., Amer M., Abd El Aziz F.

Metrology and Measurement Systems

|

2006

|

Vol. 13, nr 4

383-394

EN

An accurate linear polarized optical system for calibrating the quartz plate angles is introduced in this work. The quartz plate parallelism and surface roughness are measured using a phase shifting laser interferometer to study their effects on quartz rotation angles which equals to š18.21 sec. A polynomial regression method is applied to determine and extrapolate quartz rotation angles corresponds to the uncalibrated regions of the visible spectrum. The bi-rotation index values (nL - nR) of the quartz plates for all scanned wavelengths are determined applying the calibrated rotation angles. The uncertainty of the calibrations is evaluated, also the combined uncertainty of calibrations for angles (Δβt ≈ š0.09°) that shows the usefulness of this article.