scholarly journals Study of Physico-Chemical Interactions during the Production of Silver Citrate Nanocomposites with Hemp Fiber

Nanomaterials ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 2560
Author(s):  
Alexandru Cocean ◽  
Iuliana Cocean ◽  
Georgiana Cocean ◽  
Cristina Postolachi ◽  
Daniela Angelica Pricop ◽  
...  
Keyword(s):  
Thin Layer ◽  
Chemical Processes ◽  
Laser Deposition ◽  
Vibrational Modes ◽  
Hemp Fiber ◽  
X Ray ◽  
Eds Analysis ◽  
Physico Chemical ◽  
Silver Target ◽  
Hemp Fabric

In the study presented in this paper, the results obtained by producing nanocomposites consisting of a silver citrate thin layer deposited on hemp fiber surfaces are analyzed. Using the pulsed laser deposition (PLD) method applied to a silver target with impurities of nickel and iron, the formation of the silver citrate film is performed in various ways and the results are discussed based on Fourier Transform Infrared (FTIR) and Scanning Electron Microscopy coupled with Energy Dispersive X-Ray (SEM-EDX) spectroscopy analyses. A mechanism of the physico-chemical processes that take place based on the FTIR vibrational modes and the elemental composition established by the SEM-EDS analysis is proposed. Inhibition of the fermentation process of Saccharomyces cerevisae is demonstrated for the nanocomposite material of the silver citrate thin layer, obtained by means of the PLD method, on hemp fabric. The usefulness of composite materials of this type can extend from sensors and optoelectronics to the medical fields of analysis and treatment.

scholarly journals X-ray and UV Radiation Damage of dsDNA/Protein Complexes

Molecules ◽  
2021 ◽  
Vol 26 (11) ◽  
pp. 3132
Author(s):  
Paweł Wityk ◽  
Dorota Kostrzewa-Nowak ◽  
Beata Krawczyk ◽  
Michał Michalik ◽  
Robert Nowak
Keyword(s):  
Dna Damage ◽  
Simple Model ◽  
Uv Radiation ◽  
Protein Complexes ◽  
Chemical Processes ◽  
Model Systems ◽  
Degradation Pathways ◽  
X Ray ◽  
Physico Chemical ◽  
Sensitization Process

Radiation and photodynamic therapies are used for cancer treatment by targeting DNA. However, efficiency is limited due to physico-chemical processes and the insensitivity of native nucleobases to damage. Thus, incorporation of radio- and photosensitizers into these therapies should increase both efficacy and the yield of DNA damage. To date, studies of sensitization processes have been performed on simple model systems, e.g., buffered solutions of dsDNA or sensitizers alone. To fully understand the sensitization processes and to be able to develop new efficient sensitizers in the future, well established model systems are necessary. In the cell environment, DNA tightly interacts with proteins and incorporating this interaction is necessary to fully understand the DNA sensitization process. In this work, we used dsDNA/protein complexes labeled with photo- and radiosensitizers and investigated degradation pathways using LC-MS and HPLC after X-ray or UV radiation.

The Analysis of Morphology Characteristics of Iron Plaque on the Roots of Carex cinerascens

2014 ◽  
Vol 675-677 ◽  
pp. 140-144
Author(s):  
Chun Ying Liu ◽  
Xiao Feng Gong ◽  
Ju Yun Yang
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Chemical Properties ◽  
Amorphous Coating ◽  
X Ray ◽  
Eds Analysis ◽  
Physico Chemical ◽  
Root Surfaces ◽  
Morphology Characteristics ◽  
Scanning Electron

The physico-chemical properties of iron plaques formed on the root surfaces ofCmarex cinerascensunder laboratory conditions were determined using Scanning Electron Microscopy (SEM) and Energy Dispersive X-Ray Spectrometry (EDS) analysis. Iron plaques were present as an amorphous coating on root surfaces with an uneven distribution. EDS analysis showed that iron plaques were composed of Fe , Si, Al and lesser amounts of Ca in plaqued root surfaces.

Structural and dielectric proper ties of CaCu3Ti4O12 thin film. deposited using laser ablation.

2003 ◽  
Vol 785 ◽  
Author(s):  
V. Gupta ◽  
R.R. Das ◽  
A. Dixit ◽  
P. Bhattacharya ◽  
R.S. Katiyar
Keyword(s):  
Thin Films ◽  
Substrate Temperature ◽  
Pulsed Laser ◽  
Laser Deposition ◽  
Vibrational Modes ◽  
X Ray Diffraction ◽  
Metal Insulator ◽  
X Ray ◽  
Si Substrates ◽  
Micro Raman Spectroscopy

ABSTRACTCaCu3Ti4O12 (CCT) thin films were deposited on Pt/TiO2/SiO2/Si substrates using pulsed laser deposition technique. During the thin films deposition, the substrate temperature was varied in the range of 700–800 °C with a constant O2 pressure of 200 mTorr. X-ray diffraction showed the polycrystalline nature of the films. The dielectric properties of the films were studied in metal insulator configuration. Films grown at higher substrate temperature exhibited highest value of dielectric permittivity (∼2200). Micro Raman spectroscopy was used to study the vibrational modes of the CCT thin films in comparison with the bulk ceramics.

scholarly journals Physico-Chemical Properties of the Pyrolytic Residue Obtained by Different Treatment Conditions of Meat and Bone Meal

2021 ◽  
Vol 68 (1) ◽  
pp. 229-238
Author(s):  
Marija Zupančič ◽  
Nataša Čelan Korošin
Keyword(s):  
Chemical Properties ◽  
Environmentally Friendly ◽  
Meat And Bone Meal ◽  
Bone Meal ◽  
Heating Rates ◽  
X Ray ◽  
Eds Analysis ◽  
Treatment Conditions ◽  
Animal Bone ◽  
Physico Chemical

The depletion of phosphate rock reserves has led to the search for new, alternative and environmentally friendly products and processes. One of the safe and environmentally friendly sources of phosphate is animal bone char (ABC), the residue from the pyrolysis of meat and bone meal (MBM), a slaughterhouse waste material. The presented study investigated the physico-chemical properties of the residues (ABC) obtained from the pyrolysis of MBM under different treatment conditions. Two different end temperatures (600 °C and 1000 °C) and five different heating rates (5 °C min−1, 10 °C min−1, 20 °C min−1, 50 °C min−1 and 100 °C min−1) were used. The ABC samples obtained were characterised by X-ray powder diffraction, IR spectroscopy, elemental CHNS analysis and SEM/EDS analysis. The results showed the strong influence of both the pyrolysis end temperature and the heating rate on the morphology and chemical composition of the final products.

Development of a method for multielemental determination in water by EDXRF with radioisotopic source of 238Pu.

2019 ◽  
Vol 7 (2A) ◽  
Author(s):  
Camilo Fuentes Serrano ◽  
Juan Reinaldo Estevez Alvares ◽  
Alfredo Montero Alvarez ◽  
Ivan Pupo Gonzales ◽  
Zahily Herrero Fernandez ◽  
...  
Keyword(s):  
Thin Layer ◽  
Expanded Uncertainty ◽  
Considerable Decrease ◽  
X Ray ◽  
Precipitation Efficiency ◽  
Method Of Determination ◽  
Sensitivity Curves ◽  
Order Of Magnitude ◽  
Metrological Parameters

A method for determination of Cr, Fe, Co, Ni, Cu, Zn, Hg and Pb in waters by Energy Dispersive X Ray Fluorescence (EDXRF) was implemented, using a radioisotopic source of 238Pu. For previous concentration was employed a procedure including a coprecipitation step with ammonium pyrrolidinedithiocarbamate (APDC) as quelant agent, the separation of the phases by filtration, the measurement of filter by EDXRF and quantification by a thin layer absolute method. Sensitivity curves for K and L lines were obtained respectively. The sensitivity for most elements was greater by an order of magnitude in the case of measurement with a source of 238Pu instead of 109Cd, which means a considerable decrease in measurement times. The influence of the concentration in the precipitation efficiency was evaluated for each element. In all cases the recoveries are close to 100%, for this reason it can be affirmed that the method of determination of the studied elements is quantitative. Metrological parameters of the method such as trueness, precision, detection limit and uncertainty were calculated. A procedure to calculate the uncertainty of the method was elaborated; the most significant source of uncertainty for the thin layer EDXRF method is associated with the determination of instrumental sensitivities. The error associated with the determination, expressed as expanded uncertainty (in %), varied from 15.4% for low element concentrations (2.5-5 μg/L) to 5.4% for the higher concentration range (20-25 μg/L).

The interaction of a manganese-oxidising bacterium as part of a biofilm growing on distribution pipe materials

2000 ◽  
Vol 41 (4-5) ◽  
pp. 295-300 ◽  
Author(s):  
F. Murdoch ◽  
P.G. Smith
Keyword(s):  
Biofilm Formation ◽  
Bacterial Activity ◽  
Confocal Laser ◽  
Pipe Surface ◽  
X Ray ◽  
Pseudomonas Spp ◽  
Eds Analysis ◽  
Large Clusters ◽  
Pipe Materials ◽  
Confocal Laser Microscope

The deposition of manganese within a biofilm growing on the surface of high-density polyethlene (HDPE) and polyvinychloride (PVC) was studied over a period of four months. The manganese rich water used in the study was inoculated with a manganese oxidising Pseudomonas spp. The level of Mn2+ in the water was monitored and was found to decrease as the biofilm formation increased. This was confirmed by energy dispersive X-ray spectroscopy (EDS) analysis which showed the detection of manganese was dependent on the presence of a biofilm. After two months a 100% removal of Mn2+ was observed in all the flasks inoculated by the Pseudomonas spp. and manganese micro-nodules, the formation of which were reported in Murdoch and Smith (1999), were being formed in large clusters across the surfaces of both the HDPE and PVC. The manganese peak area from the EDS spectrum analysis of the micro-nodules was significantly larger than was measured in the biofilm when these micro-nodules were absent. The scanning confocal laser microscope (SCLM) images of three-week samples showed high bacterial activity around areas where manganese micro-nodules were starting to form on the pipe surface.

Nucleophilicity and its parametrization

1989 ◽  
Vol 54 (1) ◽  
pp. 117-135
Author(s):  
Oldřich Pytela ◽  
Vítězslav Zima
Keyword(s):  
Regression Analysis ◽  
Linear Correlation ◽  
Correlation Equation ◽  
Chemical Processes ◽  
General Tendency ◽  
Orbital Interaction ◽  
Physico Chemical ◽  
Physical And Chemical ◽  
Two Parameter ◽  
Better Than

The method of conjugate deviations based on the regression analysis has been suggested for construction of a new nucleophilicity scale. This method has been applied to a set of 28 nucleophiles participating in 47 physical and chemical processes described in literature. The two-parameter nucleophilicity scale obtained represents-in the parameter denoted as ND-the general tendency to form a bond to an electrophile predominantly on the basis of the orbital interaction and-in the parameter denoted as PD-the ability to interact with a centre similar to the proton (basicity). The linear correlation equation involving the ND, PD parameters and the charge appears to be distinctly better than the most significant relations used. The correlation dependences have the physico-chemical meaning. From the position of individual nucleophiles in the space of the ND and PD parameters, some general conclusions have been derived about the factors governing the reactivity of nucleophiles.

Sign in / Sign up

Export Citation Format

Share Document