Nghiên cứu địa hóa môi trường một số kim loại nặng trong trầm tích sông rạch thành phố Hồ Chí Minh = Geochemical study of selected heavy metal in the aquatic sediments of Hochiminh City

2007 ◽  
Vol 10 (1) ◽  
Author(s):  
Cẩm Loan Thị Từ ◽  
Hà Vy Như Nguyễn ◽  
Thanh Thủy Thị Hoàng
Keyword(s):  
Heavy Metal ◽  
Aquatic Sediments ◽  
Geochemical Study

scholarly journals Multi-Elemental Inductively Coupled Plasma-Optical Emission Spectroscopic Calibration Problems of the Sequential Extraction Procedure for the Fractionation of the Heavy Metal Content from Aquatic Sediments

2015 ◽  
Vol 43 (1) ◽  
pp. 7-14 ◽  
Author(s):  
György Heltai ◽  
Ilona Fekete ◽  
Gábor Halász ◽  
Katalin Kovács ◽  
Márk Horváth ◽  
...  
Keyword(s):  
Heavy Metal ◽  
Sequential Extraction ◽  
Inductively Coupled Plasma ◽  
Heavy Metal Contamination ◽  
Matrix Effects ◽  
Extraction Procedure ◽  
Optical Emission ◽  
Sequential Extraction Procedure ◽  
Aquatic Sediments ◽  
Inductively Coupled

Abstract For the characterisation of the environmental mobility of heavy metal contamination in aquatic sediments, the EU Bureau of Reference has proposed a fractionation by sequential extraction procedure. For its validation, the CRM-701 sample is available containing Cd, Cr, Cu, Ni, Pb, and Zn. In this paper, the matrix-matched calibration problems are presented. A multi-elemental inductively coupled plasma-optical emission technique is employed for the detection of heavy metals in the extracts. It was established that the sensitivities are strongly influenced by the extractants, which causes significant matrix effects: the sensitivities are strongly influenced by the solvents applied in extraction steps; the summarised recoveries show an acceptable agreement with the certified values; however, in the individual extraction steps for certain elements significant differences may occur due to the neglected interferences. Therefore, further optimisation is required utilising the flexible line selection possibility offered by the HORIBA Jobin Yvon ACTIVA-M instrument.

Complementary Z-Contrast Imaging and Digital Image Processing

1985 ◽  
Vol 43 ◽  
pp. 304-305
Author(s):  
K. N. Colonna ◽  
G. Oliphant
Keyword(s):  
Image Processing ◽  
Heavy Metal ◽  
Digital Image Processing ◽  
Digital Image ◽  
Biological Tissue ◽  
Biological Imaging ◽  
Tissue Preparation ◽  
Contrast Imaging ◽  
Imaging Tool ◽  
Z Contrast

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.

Recent Progress In High-Resolution Shadowing For Biological Transmission Electron Microscopy

1990 ◽  
Vol 48 (1) ◽  
pp. 510-511 ◽  
Author(s):  
Heinz Gross ◽  
Katarina Krusche ◽  
Peter Tittmann
Keyword(s):  
Heavy Metal ◽  
High Resolution ◽  
Freeze Drying ◽  
Atmospheric Conditions ◽  
Vacuum Equipment ◽  
Transmission Electron ◽  
Gas Atmosphere ◽  
Gas Molecules ◽  
Residual Gas ◽  
Backing Layer

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.

Heavy Metal Tales

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

Musik und Gesundheit

2010 ◽  
Vol 21 (1) ◽  
pp. 1-6
Author(s):  
Hans-Joachim Trappe
Keyword(s):  
Heavy Metal ◽  
Physiologische Parameter

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.

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