scholarly journals THEORETICAL STUDIES CONCERNING RESIDUAL SOIL POLLUTION BY HEAVY METALS

2016 ◽  
Vol 19 (2) ◽  
Author(s):  
CRISTIAN RADU ◽  
VALENTIN NEDEFF ◽  
ALEXANDRA-DANA CHIŢIMUŞ
Keyword(s):  
Heavy Metals ◽  
Soil Pollution ◽  
Chemical Properties ◽  
Contaminated Site ◽  
Residual Soil ◽  
Theoretical Studies ◽  
Physical And Chemical Properties ◽  
Physical And Chemical ◽  
And Chemical Properties

<p>The paper describes a series of theoretical aspects concerning residual soil pollution by heavy metals. Heavy metals, unlike organic and radionuclide pollutants, are considered to be the most persistent/resistant polluting substances in the soil, displaying a tendency for accumulation. The behavior of heavy metals in the soil depends on the physical and chemical properties of the soil, as well as on their origin and source. Knowledge of the properties of heavy metals is very important, having in view the necessity of applying isolation measures for a contaminated site.</p>

scholarly journals Topological Aspects of Boron Nanotubes

2018 ◽  
Vol 2018 ◽  
pp. 1-11 ◽  
Author(s):  
Jia-Bao Liu ◽  
Hani Shaker ◽  
Imran Nadeem ◽  
Muhammad Hussain
Keyword(s):  
Thermal Stability ◽  
Electronic Properties ◽  
Chemical Structure ◽  
Chemical Properties ◽  
Topological Indices ◽  
The Other ◽  
Theoretical Studies ◽  
Physical And Chemical Properties ◽  
Physical And Chemical ◽  
And Chemical Properties

The degree-based topological indices are used to correlate the physical and chemical properties of a molecule with its chemical structure. Boron nanotubular structures are high-interest materials due to the presence of multicenter bonds and have novel electronic properties. These materials have some important issues in nanodevice applications like mechanical and thermal stability. Therefore, they require theoretical studies on the other properties. In this paper, we present certain degree-based topological indices such as ABC, the fourth ABC, GA, and the fifth GA indices for boron triangular and boron-α nanotubes.

Theoretical and Spectroscopic Characterization of API-Related Azoles in Solution and in Solid State

2020 ◽  
Vol 26 (38) ◽  
pp. 4847-4857
Author(s):  
Marta Marín-Luna ◽  
Rosa M. Claramunt ◽  
José Elguero ◽  
Ibon Alkorta
Keyword(s):  
Solid State ◽  
Crystal Packing ◽  
Chemical Properties ◽  
Spectroscopic Characterization ◽  
Complete Characterization ◽  
Theoretical Studies ◽  
Physical And Chemical Properties ◽  
Physical And Chemical ◽  
And Chemical Properties

Azoles are a family of five-membered azacyclic compounds with relevant biological and pharmacological activity. Different subclasses of azoles are defined depending on the atomic arrangement and the number of nitrogen atoms present in the ring: pyrazoles, indazoles, imidazoles, benzimidazoles, triazoles, benzotriazoles, tetrazoles and pentazoles. The complete characterization of their structure and the knowledge about their crystal packing and physical and chemical properties are of vital importance for the advancement in the design of new azole-containing drugs. In this review, we report the latest recent contributions to azole chemistry, in particular, those in which theoretical studies have been performed.

Progress of Removing Heavy Metals by Zero Valent Iron Nanoparticles from Wastewater

2013 ◽  
Vol 726-731 ◽  
pp. 2563-2566
Author(s):  
Jing Jing Guo ◽  
Ming De Fan
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Iron Nanoparticles ◽  
Chemical Properties ◽  
Soil Restoration ◽  
Physical And Chemical Properties ◽  
Carrier Materials ◽  
Zero Valent Iron Nanoparticles ◽  
Physical And Chemical ◽  
And Chemical Properties

Heavy metal pollution is a serious threat to human health. Because of the development of nanotechnology, removal of heavy metal is more convenient and effective. nanozero valent iron (Fe0) particles have high activity and specific surface area. At present, Fe0 nanoparticles have been used in the processing of refractory organics, heavy metals, inorganic salts, soil restoration, and other areas of the environment. But the dispersion and stability of the Fe0 nanoparticles are poor. We can improve physical and chemical properties of Fe0 by adding carrier materials to make iron nanoparticles have better stability, dispersion and the treatment effect. This paper mainly introduced the situation of removing heavy metals by the Fe0 nanoparticles and hybridized Fe0 particles. Hybridized Fe0 has good performance and high removal efficiency to heavy metals. We also discussed what are inadequate and need to be further researched.

scholarly journals Evaluasi sifat fisika, kimia dan kandungan logam berat di dalam nata de coco yang dibuat menggunakan sumber nitrogen dari NPK

2021 ◽  
Vol 12 (2) ◽  
pp. 250-256
Author(s):  
Budi Santosa ◽  
Wirawan Wirawan
Keyword(s):  
Heavy Metals ◽  
Chemical Properties ◽  
Nitrogen Sources ◽  
Total Sample ◽  
Fiber Content ◽  
Physical And Chemical Properties ◽  
Physical Chemical ◽  
Physical And Chemical ◽  
Cu And Zn ◽  
And Chemical Properties

Nata de coco one of the beverage products produced from fermented coconut water using the help of starter Acetobacter xylinum. This product is very popular with people ranging from children to parents because the shape and texture resembles a gel.  This study aims to evaluate the physical, chemical and heavy metal content in nata de coco made using nitrogen sources from NPK. The experimental plan used by The Complete Randomized Plan (RAL) is a single factor, the factor is the concentration of NPK consisting of 5 levels of K1 = 0.25%, K2 = 0.5%, K3 = 1%, K4 = 1.5%, K5 = 2%.  Each treatment was repeated 5 times and the total sample observed a total of 25 pieces. The observed observation parameters of nata thickness, nata weight, total fiber content of nata and metal residue content in nata include Cu, Zn, Pb metals, all of which are observed at the end of fermentation (the 14th day of fermentation). The initial parameters of the formation of nata are observed from the beginning of fermentation until the nata sheet is first formed. The results showed that nata de coco made using nitrogen source from NPK concentration of 0.1% has the best physical and chemical properties namely thickness of nata: 1,438 cm, weight of nata: 309 grams, initial formation of nata 3.2 days and total fiber content of nata: 4.024%. The use of NPK produces residues in the form of heavy metals Cu and Zn while pb heavy metals are undetectable. The higher the concentration of NPK given as a source of nitrogen, the higher the residues of heavy metals Cu and Zn in the nata de coco.

scholarly journals Chains of carbon atoms: A vision or a new nanomaterial?

2015 ◽  
Vol 6 ◽  
pp. 559-569 ◽  
Author(s):  
Florian Banhart
Keyword(s):  
Experimental Situation ◽  
Chemical Properties ◽  
Experimental Information ◽  
Theoretical Studies ◽  
Physical And Chemical Properties ◽  
One Dimensional ◽  
The Past ◽  
The Stability ◽  
Physical And Chemical ◽  
And Chemical Properties

Linear strings of sp1-hybridized carbon atoms are considered as a possible phase of carbon since decades. Whereas the debate about the stability of the corresponding bulk phase carbyne continues until today, the existence of isolated chains of carbon atoms has meanwhile been corroborated experimentally. Since graphene, as the two-dimensional sp2-bonded allotrope of carbon, has become a vast field, the question about the importance of one-dimensional carbon became of renewed interest. The present article gives an overview of the work that has been carried out on chains of carbon atoms in the past one or two decades. The review concentrates on isolated chains of carbon atoms and summarizes the experimental observations to date. While the experimental information is still very limited, many calculations of the physical and chemical properties have been published in the past years. Some of the most important theoretical studies and their importance in the present experimental situation are reviewed.

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