scholarly journals Investigating the Correlation of Microplastic Pollution Between Seawater and Marine Salt Using Micro-Raman Spectroscopy

2021 ◽  
Vol 8 ◽  
Author(s):  
Vo Thi Kim Khuyen ◽  
Dinh Vu Le ◽  
Le Hung Anh ◽  
Axel René Fischer ◽  
Christina Dornack
Keyword(s):  
Raman Spectroscopy ◽  
Biosphere Reserve ◽  
Pollution Source ◽  
Sea Salt ◽  
Contamination Level ◽  
Plastic Pollution ◽  
Potential Health ◽  
Micro Raman Spectroscopy ◽  
Can Gio Mangrove ◽  
Marine Salt

Microplastics (MPs) are synthetic polymer pieces with a size of less than 5 mm that are ubiquitous in the marine environment. They have been recently detected in several wild species and sea products. An indispensable condiment in human food is marine salt that is produced from seawater. Since toxicity studies report potential health impacts when plastic debris is ingested, more attention must be paid to the MP contamination of sea salt and the underlying reasons for this. The central aim of this study is to evaluate the MPs contamination level of sea salt in correlation with the MPs contamination level of seawater in Vietnamese areas. Micro-Raman spectroscopy was employed to determine MPs in the samples collected from three artificial salt pans of Vietnam. The result revealed the presence of MPs in all study areas—Vung Tau (VT;14.54 MPs/L seawater and 114.67 MPs/kg salt), Ly Nhon (LN; 13.14 MPs/L seawater and 63.59 MPs/kg salt), and Can Thanh (9.42 MPs/L seawater and 93.69 MPs/kg salt). The comparisons highlight close correlations in the percentage, shape, size, and color of MPs, especially polyethylene, polyethylene terephthalate, and polypropylene particles extracted from the seawater and its salt. This study proved that seawater is a plastic pollution source for salts produced by traditional seawater evaporation. The study also alerts the prevalence of MPs in the environment and human consumables, thereby indicating that actions must be taken to reduce the pollution of water sources in Vung Tau and at the UNESCO Can Gio Mangrove Biosphere Reserve and improve salt production and refinery processes in order to minimize the number of MPs in final salt products for safe consumption.

Micro-Raman Spectroscopy Evaluation of the Local Mechanical Stress in Shallow Trench Isolation CMOS Structures: Correlation with Defect Generation and Diode Leakage

1998 ◽  
Author(s):  
I. De Wolf ◽  
G. Groeseneken ◽  
H.E. Maes ◽  
M. Bolt ◽  
K. Barla ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Mechanical Stress ◽  
Defect Formation ◽  
Active Area ◽  
Wet Oxidation ◽  
Leakage Currents ◽  
Shallow Trench Isolation ◽  
Micro Raman Spectroscopy ◽  
Silicon Devices ◽  
Trench Isolation

Abstract It is shown, using micro-Raman spectroscopy, that Shallow Trench Isolation introduces high stresses in the active area of silicon devices when wet oxidation steps are used. These stresses result in defect formation in the active area, leading to high diode leakage currents. The stress levels are highest near the outer edges of line structures and at square structures. They also increase with decreasing active area dimensions.

Micro-Raman spectroscopy of Shang oracle bone inscriptions

2021 ◽  
Vol 37 ◽  
pp. 102910
Author(s):  
Jhih-Huei Liu ◽  
Weiying Ke ◽  
Ming-chorng Hwang ◽  
Kuang Yu Chen
Keyword(s):  
Raman Spectroscopy ◽  
Micro Raman Spectroscopy

scholarly journals Use of WetSEM® capsules for convenient multimodal scanning electron microscopy, energy dispersive X-ray analysis, and micro Raman spectroscopy characterisation of technetium oxides

2021 ◽  
Author(s):  
D. J. Bailey ◽  
M. C. Stennett ◽  
J. Heo ◽  
N. C. Hyatt
Keyword(s):  
Raman Spectroscopy ◽  
Low Cost ◽  
Powder Materials ◽  
Spectroscopy Analysis ◽  
X Ray ◽  
Micro Raman Spectroscopy ◽  
Hazard And Risk ◽  
Sem Imaging ◽  
General User ◽  
532 Nm

AbstractSEM–EDX and Raman spectroscopy analysis of radioactive compounds is often restricted to dedicated instrumentation, within radiological working areas, to manage the hazard and risk of contamination. Here, we demonstrate application of WetSEM® capsules for containment of technetium powder materials, enabling routine multimodal characterisation with general user instrumentation, outside of a controlled radiological working area. The electron transparent membrane of WetSEM® capsules enables SEM imaging of submicron non-conducting technetium powders and acquisition of Tc Lα X-ray emission, using a low cost desktop SEM–EDX system, as well as acquisition of good quality μ-Raman spectra using a 532 nm laser.

scholarly journals Eco-Friendly Poly(Vinyl Alcohol) Nanofiber-Based Air Filter for Effectively Capturing Particulate Matter

2021 ◽  
Vol 11 (9) ◽  
pp. 3831
Author(s):  
Han-Jung Kim ◽  
Dong-In Choi ◽  
Sang-Keun Sung ◽  
Su-Han Lee ◽  
Sang-Jin Kim ◽  
...  
Keyword(s):  
Particulate Matter ◽  
Quality Factor ◽  
Vinyl Alcohol ◽  
Nonwoven Fabric ◽  
Poly Vinyl Alcohol ◽  
Contamination Level ◽  
Plastic Pollution ◽  
Air Filters ◽  
Air Filter ◽  
Filter Surface

Due to the increasing use of polypropylene-based nonwoven dust masks and air filters, environmental problems that occur due to the plastic pollution resulting from the disposal of these materials have also increased. Hence, an eco-friendly air filter based on PVA nanofibers (NFs) was fabricated by electrospinning on a nonwoven fabric, and its performance was evaluated as a filter capable of blocking or capturing particulate matter. The quality factor of the optimized PVA NF-based air filter was found to be 0.010606 Pa−1, which is lower than that of a HEPA filter (0.015394 Pa−1), but higher than that of a cabin air filter (0.010517 Pa−1) and a dust mask (0.009102 Pa−1). The contamination level of the PVA NF-based filter was analyzed by optical and structural analyses of the filter surface. Finally, the filter was soaked in water to selectively remove the contaminated PVA NF layer, and the remaining nonwoven fabric was able to be reused to make the filter.

scholarly journals Comparison of Microplastic Pollution in Beach Sediment and Seawater at UNESCO Can Gio Mangrove Biosphere Reserve

2021 ◽  
pp. 2100044
Author(s):  
Vo Thi Kim Khuyen ◽  
Dinh Vu Le ◽  
Axel René Fischer ◽  
Christina Dornack
Keyword(s):  
Biosphere Reserve ◽  
Beach Sediment ◽  
Can Gio Mangrove

scholarly journals Influence of Different Conditioning Treatments on The Bond Integrity of Root Dentin to rGO Infiltrated Dentin Adhesive. SEM, EDX, FTIR and MicroRaman Study

Polymers ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 1555
Author(s):  
Firas Alqarawi ◽  
Mazen Alkahtany ◽  
Khalid Almadi ◽  
Afnan Gassem ◽  
Faris Alshahrani ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Bond Strength ◽  
Strength Test ◽  
Control Group ◽  
Micro Raman Spectroscopy ◽  
Fiber Posts ◽  
Root Canal Disinfection ◽  
Reduced Graphene ◽  
Root Dentin ◽  
Push Out

The present study aimed to synthesize and equate the mechanical properties and dentin interaction of two adhesives; experimental adhesive (EA) and 5 wt.% reduced graphene oxide rGO) containing adhesive. Scanning electron microscopy (SEM)-Energy-dispersive X-ray spectroscopy (EDX), Micro-Raman spectroscopy, push-out bond strength test, and Fourier Transform Infrared (FTIR) spectroscopy were employed to study nano-bond strength, degree of conversion (DC), and adhesive-dentin interaction. The EA was prepared, and rGO particles were added to produce two adhesive groups, EA-rGO-0% (control) and rGO-5%. The canals of sixty roots were shaped and prepared, and fiber posts were cemented. The specimens were further alienated into groups based on the root canal disinfection technique, including 2.5% sodium hypochlorite (NaOCl), Photodynamic therapy (PDT), and ER-CR-YSGG laser (ECYL). The rGO nanoparticles were flake-shaped, and EDX confirmed the presence of carbon (C). Micro-Raman spectroscopy revealed distinct peaks for graphene. Push-out bond strength test demonstrated highest values for the EA-rGO-0% group after NaOCl and PDT conditioning whereas, rGO-5% showed higher values after ECYL conditioning. EA-rGO-0% presented greater DC than rGO-5% adhesive. The rGO-5% adhesive demonstrated comparable push-out bond strength and rheological properties to the controls. The rGO-5% demonstrated acceptable DC (although lower than control group), appropriate dentin interaction, and resin tag establishment.

scholarly journals Knowledge about Microplastic in Mediterranean Tributary River Ecosystems: Lack of Data and Research Needs on Such a Crucial Marine Pollution Source

2020 ◽  
Vol 8 (3) ◽  
pp. 216 ◽  
Author(s):  
Cristiana Guerranti ◽  
Guido Perra ◽  
Tania Martellini ◽  
Luisa Giari ◽  
Alessandra Cincinelli
Keyword(s):  
Marine Pollution ◽  
Distribution Patterns ◽  
Pollution Source ◽  
Freshwater Ecosystems ◽  
Abundance Distribution ◽  
Plastic Pollution ◽  
Marine Systems ◽  
Final Destination ◽  
Lack Of Information ◽  
Freshwater Environments

Plastic debris occurring in freshwater environments, which can either come from the surrounding terrestrial areas or transported from upstream, has been identified as one of the main sources and routes of plastic pollution in marine systems. The ocean is the final destination of land- based microplastic sources, but compared to marine environments, the occurrence and effects of microplastics in freshwater ecosystems remain largely unknown. A thorough examination of scientific literature on abundance, distribution patterns, and characteristics of microplastics in freshwater environments in Mediterranean tributary rivers has shown a substantial lack of information and the need to apply adequate and uniform measurement methods.

scholarly journals New minerals tsangpoite Ca5(PO4)2(SiO4) and matyhite Ca9(Ca0.5□0.5)Fe(PO4)7 from the D'Orbigny angrite

2018 ◽  
Vol 83 (02) ◽  
pp. 293-313 ◽  
Author(s):  
Shyh-Lung Hwang ◽  
Pouyan Shen ◽  
Hao-Tsu Chu ◽  
Tzen-Fu Yui ◽  
Maria-Euginia Varela ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Raman Spectroscopy ◽  
Electron Diffraction ◽  
Grain Boundary ◽  
Electron Probe ◽  
Formation Mechanisms ◽  
Formula Unit ◽  
Micro Raman Spectroscopy ◽  
The Common ◽  
Oxygen Atoms

AbstractTsangpoite, ideally Ca5(PO4)2(SiO4), the hexagonal polymorph of silicocarnotite, and matyhite, ideally Ca9(Ca0.5□0.5)Fe(PO4)7, the Fe-analogue of Ca-merrillite, were identified from the D'Orbigny angrite meteorite by electron probe microanalysis, electron microscopy and micro-Raman spectroscopy. On the basis of electron diffraction, the symmetry of tsangpoite was shown to be hexagonal,P63/morP63, witha= 9.489(4) Å,c= 6.991(6) Å,V= 545.1(6) Å3andZ= 2 for 12 oxygen atoms per formula unit, and that of matyhite was shown to be trigonal,R3c, witha= 10.456 (7) Å,c= 37.408(34) Å,V= 3541.6 (4.8) Å3andZ= 6 for 28 oxygen atoms per formula unit. On the basis of their constant association with the grain-boundary assemblage: Fe sulfide + ulvöspinel + Al–Ti-bearing hedenbergite + fayalite–kirschsteinite intergrowth, the formation of tsangpoite and matyhite, along with kuratite (the Fe-analogue of rhönite), can be readily rationalised as crystallisation from residue magmas at the final stage of the D'Orbigny meteorite formation. Alternatively, the close petrographic relations between tsangpoite/matyhite and the resorbed Fe sulfide rimmed by fayalite + kirschsteinite symplectite, such as the nucleation of tsangpoite in association with magnetite ± other phases within Fe sulfide and the common outward growth of needle-like tsangpoite or plate-like matyhite from the fayalite–kirschsteinite symplectic rim of Fe sulfide into hedenbergite, infer that these new minerals and the grain-boundary assemblage might represent metasomatic products resulting from reactions between an intruding metasomatic agent and the porous olivine–plagioclase plate + fayalite-kirschsteinite overgrowth + augite + Fe sulfide aggregates. Still further thermochemical and kinetics evidence is required to clarify the exact formation mechanisms/conditions of the euhedral tsangpoite, matyhite and kuratite at the grain boundary of the D'Orbigny angrite.

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