LIBS Detection Characteristics of Trace Heavy Metal in Different Buffer Gases

Author(s):  
Zhenzhen Wang ◽  
Renwei Liu ◽  
Ruomu Hu ◽  
Wangzheng Zhou ◽  
Junjie Yan ◽  
...  
Author(s):  
K. N. Colonna ◽  
G. Oliphant

Harmonious use of Z-contrast imaging and digital image processing as an analytical imaging tool was developed and demonstrated in studying the elemental constitution of human and maturing rabbit spermatozoa. Due to its analog origin (Fig. 1), the Z-contrast image offers information unique to the science of biological imaging. Despite the information and distinct advantages it offers, the potential of Z-contrast imaging is extremely limited without the application of techniques of digital image processing. For the first time in biological imaging, this study demonstrates the tremendous potential involved in the complementary use of Z-contrast imaging and digital image processing.Imaging in the Z-contrast mode is powerful for three distinct reasons, the first of which involves tissue preparation. It affords biologists the opportunity to visualize biological tissue without the use of heavy metal fixatives and stains. For years biologists have used heavy metal components to compensate for the limited electron scattering properties of biological tissue.


Author(s):  
Heinz Gross ◽  
Katarina Krusche ◽  
Peter Tittmann

Freeze-drying followed by heavy metal shadowing is a long established and straight forward approach to routinely study the structure of dehydrated macromolecules. Very thin specimens such as isolated membranes or single macromolecules are directly adsorbed on C-coated grids. After rapid freezing the grids are transferred into a suitable vacuum equipment for freeze-drying and heavy metal shadowing.To improve the resolution power of shadowing films we introduced shadowing at very low specimen temperature (−250°C). To routinely do that without the danger of contamination we developed in collaboration with Balzers an UHV (p≤10-9 mbar) machine (BAF500K, Fig.2). It should be mentioned here that at −250°C the specimen surface acts as effective cryopump for practically all impinging residual gas molecules from the residual gas atmosphere.Common high resolution shadowing films (Pt/C, Ta/W) have to be protected from alterations due to air contact by a relatively thick C-backing layer, when transferred via atmospheric conditions into the TEM. Such an additional C-coat contributes disturbingly to the contrast at high resolution.


2008 ◽  
Vol 42 (2) ◽  
pp. 24
Author(s):  
WILLIAM G. WILKOFF
Keyword(s):  

2010 ◽  
Vol 21 (1) ◽  
pp. 1-6
Author(s):  
Hans-Joachim Trappe

Zusammenfassung. Musik (M) spielt im Leben eines jeden Menschen nicht nur eine wichtige Rolle, sondern hat auch Effekte auf Herzfrequenz (HF), Herzfrequenzvariabilität (HRV) und auf andere physiologische Parameter. Bei Musikern sind die Beeinflussungen von HF, HRV und autonomen Nervensystem größer als bei Musik-Zuhörern. Obgleich M als subjektives Empfinden zu interpretieren ist, zeigen Studien, dass objektive Parameter unter verschiedenen Umständen eindeutig durch Musik beeinflusst werden. Es wurde nachgewiesen, dass M als Prämedikation zu einer signifikant niedrigen Ängstlichkeitsrate führte als Midazolam (p < 0,001). M wird auch bei anderen Situationen eingesetzt, bei depressiven Menschen, alten Menschen, zur Schmerztherapie und im Rahmen der Intensiv- bzw. Palliativmedizin. M sollte jedoch individuell nach den Wünschen der Pt ausgewählt werden. Nur so lassen sich die gewünschten Effekte erreichen, Ängste vermeiden und führen zu einer Verbesserung der Lebensqualität (QoL). Die besten M-Effekte sind durch klassische oder meditative M zu erreichen, Heavy Metal or Techno-M ist ineffektiv oder gar schädlich und kann zu Stress oder lebensgefährlichen Arrhythmien führen. Es gibt viele Komponisten, deren M zu einer Verbesserung der QoL führt, besonders Bach, Mozart oder italienische Komponisten sind hier zu nennen.


1994 ◽  
Vol 92 (2) ◽  
pp. 364-368 ◽  
Author(s):  
Ulrich Galli ◽  
Hannes Schuepp ◽  
Christian Brunold

2020 ◽  
Vol 2 (1) ◽  
Author(s):  
Rizki Andalia ◽  
Mulia Aria Suzanni ◽  
Rini Rini

Lipstick or lip dye is a cosmetic dose that serves to coloring, decorative the lips, as a moisturizing material and protect the lips from exposure the sun to provide optimum results. Lipstick should not contain chemicals such as lead (Pb) because the Pb is a heavy metal that is very dangerous when continuously used on the skin, because it will be absorbed into the blood and attack the body organ causing the onset of disease. According to BPOM that the lead rate on the lipstick does not exceed the permissible limit of 20 mg/kg or 20 ppm.This research aims to know the levels contained in the samples are 4 brands of matte lipstick that are sold in the Aceh market in Banda Aceh City with the method of atomic absorption spectrophotometry (AAS). The results showed that on the 4 brands of lipstick matte contain heavy metal lead (Pb) with a rate still qualified allowed by BPOM  is samples A, B, C, and D, respectively at 0.24 ppm; 0.10 ppm; 2.87 ppm and 1.32 ppm, so that the 4 brands of lipstick matte are still used.


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