Cadmium Element Research Articles

Electron-interface-phonon interactions and its ternary effects on in ZnS/CdxZn1-xS core-shell heterostructures

Within the framework of dielectric continuum mode (DCM), random-element isodisplacement model (REIM) and standard quantization procedure, the electron-interface-phonon interactions and its ternary effects in ZnS/CdxZn1-xS core-shell heterostructures are investigated. The dispersion curves, the electron-phonon couplings and its ternary mixed crystal effects of interface optical (IO) phonons in ZnS/CdxZn1-xS core-shell heterostructures are calculated and discussed in detail. The results indicate that the IO phonons are more dispersive in low quantum number. With the increase of the cadmium element concentration, the IO phonon frequencies decrease linearly in high frequency range (HF-range), and decreases non-linearly in low frequency range (LF-range). The numerical results also indicate that the IO phonons with lower quantum number play a significant role in electron-phonon interactions. The electron-phonon coupling strengths increase linearly in HF-range, and increase non-linearly in LF-range with the increasing cadmium element concentration. The IO phonons in HF-range have prominent contributions to electron-phonon interactions.Within the framework of dielectric continuum mode (DCM), random-element isodisplacement model (REIM) and standard quantization procedure, the electron-interface-phonon interactions and its ternary effects in ZnS/CdxZn1-xS core-shell heterostructures are investigated. The dispersion curves, the electron-phonon couplings and its ternary mixed crystal effects of interface optical (IO) phonons in ZnS/CdxZn1-xS core-shell heterostructures are calculated and discussed in detail. The results indicate that the IO phonons are more dispersive in low quantum number. With the increase of the cadmium element concentration, the IO phonon frequencies decrease linearly in high frequency range (HF-range), and decreases non-linearly in low frequency range (LF-range). The numerical results also indicate that the IO phonons with lower quantum number play a significant role in electron-phonon interactions. The electron-phonon coupling strengths increase linearly in HF-range, and increase non-linearly in LF-range with the incr...

Interface optical phonons and its ternary mixed effects in ZnS/CdxZn1-xS quantum dots

Taking into account cadmium element concentrations, the interface optical (IO) phonons, electron-phonon couplings in ZnS/CdxZn1-xS quantum dots are investigated theoretically within the framework of macroscopical dielectric continuum model (MDCM) and modified random-element isodisplacement model (MREIM). The numerical results indicate that the cadmium element concentrations have important effects on the properties of IO phonons and electron-phonon interactions in a single ZnS/CdxZn1-xS quantum dot. The dependences between IO phonon frequencies and cadmium element concentrations are linearly decreases in high frequency range (HF-range), and are non-linearly decreases in low frequency range (LF-range). The numerical results also suggest that the dependent relations between the absolute value of electron-phonon coupling strengths and cadmium element concentration are linear relationship in high frequency range (HF-range), and are non-linear relationship in low frequency range (LF-range), especially in higher cadmium element concentration range.

A study of some physical properties and chemical and biological water to the Tigris River near the Alshuhadah Bridge and evaluated for different purposes for the period (2012-2014)

The research investigates some physical, chemical and biological properties of the Tigris water River near the Alshuhadah Bridge and evaluated these properties for drinking, irrigation industrial and construction purposes for the period (2012-2014), and until July for the year (2014) due to the lack of data for the rest of the year.
 Through the analysis of properties results it had been found that there is some variation during the months of the year, as well as between the annual averages for the three years where the Cadmium element did not record any value, which was equal to zero, as well as the iron element except for the month of May for the year (2013). In addition, it was noted that the Tigris River water near the Alshuhadah bridge in the month of May for the year (2012 ) and the month of July of the year (2013) within the class (C2) which is a brackish water and it needs to filtering operations for some crops which are sensitive to salinity and that due to lack of the total dissolved salts in the water in the mentioned two months(July and May), while it found in the rest of the three years months within the class ( C3) which is a high-salinity water and cannot be used without continuouslydrainage. The value of (PH) of the water was found within the permissible limits for drinking, irrigation and industrial purposes and has taken the baseband side during the three years with except for the month of December for the year (2012) and the month of April for the year ( 2014) which was neutral in pH (PH = 7), while it noticed that in the month of May for the year (2014) was acidic (PH =6.89) and the value of (TDS), sodium and nitrate for the three years within the permissible limits for drinking purposes. In addition, the value of the absorbed vital oxygen was within the permissible limits for irrigation purposes. Also the value of chlorides, carbonates and boron for the three years was within the permissible limits for drinking and irrigation, while the rest items values fluctuated between the permitted and non-permitted to be used for these purposes, Besides that, the values of calcium, magnesium, sodium and chlorides for the three years was within the allowed boundaries for the purposes of building and construction. While the usage of water for industrial purposes for affected components in industry, it had fluctuated between permitted and non-permitted for using.
 

Growth and characterization of pure and cadmium dichloride doped aminoethanoic acid (AEA) single crystals

Organic and semiorganic centrosymmetry single crystals of pure and cadmium dichloride doped aminoethanoic acid was successfully grown by slow evaporation solution growth technique. The solubility of the grown crystals was studied for different temperatures upto 50 °C. The single crystal X-ray diffraction analysis shows that the grown crystal belongs to monoclinic system and their unit cell parameter values were determined. The presence of various functional groups was identified by Fourier transform infrared spectroscopy. UV–Vis spectrum shows a wide optical transmittance in the visible region and the obtained lower cut off wavelength is around 252 nm. The presence of 0.31 mg of cadmium element per litre of water was measured by AAS analysis which indicates the effect of dopant in the material. TG/DTA study reveals that the organic complex has slightly more stable than the semiorganic complex and it has high thermal stability of about 193 °C. Vickers microhardness tester confirms the reverse indentation size effect of the crystals and found that the crystals belongs to soft material category by Meyer law. Dielectric study was carried out on the grown crystals which represent the lower value of dielectric constant while increase the frequency.

Cd元素在土壤–水稻系统中的富集和分布

本文选取四川某地为研究区，配套采集了33套水稻土壤和水稻植株样本，分析测试了水稻籽实、茎、叶三部分以及对应土壤中Cd元素的含量；同时测试了土壤中Cd元素不同赋存形态的分量数据。通过对以上数据的分析处理，得出以下结论：该区域水稻中Cd元素超标率达到84.8%，最高达11.85 mg/kg，已经超过了国家食品卫生标准的59倍；从富集情况看，Cd从土壤迁移到水稻各部分迁移能力为籽实 > 茎 >叶；从土壤中Cd的相态来看，离子交换态和水溶态占全量的30.62%，碳酸盐结合态在弱酸性环境下容易释放出来被吸收，占比也达到了8.45%，对于水稻作物来讲，具有一定的安全威胁；从相态的变异系数来看，只有水溶态以及残渣态均超过了50%，尤其是水溶态，达到了152.5%，显示出这两种相态在土壤中分布不均匀；理论上，当样本数量增加到45个，籽实中Cd与土壤中水溶态相关性达到显著正相关；土壤中pH值与水稻茎、叶、籽实以及地上部分均呈负相关，与土壤中Cd含量显著正相关，结合土壤中Cd形态与pH和有机质的相关性分析，pH升高，碳酸盐结合态、腐殖酸结合态、铁锰结合态、强有机结合态均有较大程度的提高，水溶态降低；提高有机质含量有助于降低土壤中Cd活跃形态，同时降低地上部分中Cd含量。 33 sets of paddy soil and rice plants were sampled from a certain place of Sichuan province. Cadmium contents in these rice plant samples, including their rice seeds, stems, leaves, and their corresponding soil system have been analyzed and tested. Component data of cadmium elements in different forms have been screened as well. Based on the data mentioned above, the following conclusions can be drawn: 84.8% of cadmium contents in the rice plants samples were above the regulatory limits, and the maximum cadmium level reached 11.85 mg/kg, 59 times higher than the National Quality Standard for food. In terms of the enrichment, migration abilities of cadmium from soil to 3 parts of rice plants in descending order were: seeds, stem, and leaf. In terms of phase distribution, ion-exchangeable and water-soluble cadmium make up 30.62% of the total cadmium. Carbonate cadmium that was easily released and absorbed in weak acidic environment became security threats to the rice crops, accounting for 8.45%. The coefficient of variation of phase state showed that only the water-soluble and residua were more than 50% and cadmium in water soluble state was most impressive, up to 152.5%. It showed the two phases were not distributed uniformly in the soil. When the amount of samples increases to a certain extent, cadmium element in the rice seeds was directly proportional to the water-soluble. pH of soil was negatively correlated to rice stems, leaves, seeds and the aboveground and was positively correlated with cadmium content. A correlation analysis of cadmium phases, pH and organism showed that the carbonate, humate, iron-manganese and organic increased a lot as pH increased, while the water-soluble decreased as pH increased. The increase of organic matter content contributed to decrease active phases of cadmium in soil, and decreased cadmium content in the aboveground parts as well.

Bioremediation of Lead and Cadmium Contaminated soil by Sesbania rostrata plant and AM fungi Glomus mosseae

This study was conducted to determine the activity of plant Sesbania rostrata and two isolate from arbuscular mycorrhizae fungi (A,B) as a bioremediation of soil polluted by cadmium and lead elements in north and south of Baghdad city. The results showed that the average of soil pollution by cadmium and lead elements in north of Baghdad was less than the average of soil pollution in the south of Baghdad which recorded 10.0, 9.0 mg/kg and 27.0, 25.0 mg/kg respectively. The plant Sesbania recorded ability to accumulate the lead element in shoot system 19.65 mg/kg and in root system 27.2 mg/kg and for cadmium element 19.6, 24.6 mg/kg in shoot and root respectively. The results showed that the isolate A from soil pollution is more effected than isolate B which isolated from uncontaminated soil.

Numerical study of the influence of ZnTe thickness on CdS/ZnTe solar cell performance

At present most of II–VI semiconductor based solar cells use the CdTe material as an absorber film. The simulation of its performance is realized by means of various numerical modelling programs. We have modelled a solar cell based on zinc telluride (ZnTe) thin film as absorber in substitution to the CdTe material, which contains the cadmium element known by its toxicity. The performance of such photovoltaic device has been numerically simulated and the thickness of the absorber layer has been optimized to give the optimal conversion efficiency. A photovoltaic device consisting of a ZnTe layer as absorber, CdS as the buffer layer and ZnO as a window layer was modelled through Solar Cell Capacitance Simulator Software. Dark and illuminated I-V characteristics and the results for different output parameters of ZnO/CdS/ZnTe solar cell were analyzed. The effect of ZnTe absorber thickness on different main working parameters such as: open-circuit voltage Voc , short-circuit current density Jsc , fill factor FF, photovoltaic conversion efficiency η was intensely studied in order to optimize ZnTe film thickness. This study reveals that increasing the thickness of ZnTe absorber layer results in higher efficiency until a maximum value and then decreases slightly. This maximum was found to be 10% at ZnTe optimum thickness close to 2 µ m.

Bioremediation of Lead and Cadmium Contaminated soil by Sesbania rostrata plant and AM fungi Glomus mosseae

This study was conducted to determine the activity of plant Sesbania rostrata and two isolate from arbuscular mycorrhizae fungi (A,B) as a bioremediation of soil polluted by cadmium and lead elements in north and south of Baghdad city. The results showed that the average of soil pollution by cadmium and lead elements in north of Baghdad was less than the average of soil pollution in the south of Baghdad which recorded 10.0, 9.0 mg/kg and 27.0, 25.0 mg/kg respectively. The plant Sesbania recorded ability to accumulate the lead element in shoot system 19.65 mg/kg and in root system 27.2 mg/kg and for cadmium element 19.6, 24.6 mg/kg in shoot and root respectively. The results showed that the isolate A from soil pollution is more effected than isolate B which isolated from uncontaminated soil.

Investigation of cadmium pollution in contaminated industrial area in Guilan province industrial estates

Toxicity and accumulation of cadmium in body organs by eating contaminated food has an important role in endangering a human's health. Using Environmental Protection Agency (EPA) reports, site 1, site 2 and site 3 were selected as polluted sites and site 4 was selected as the control site. Seedlings of buttonwood were prepared for 12 months then root, stem, and leaf samples were harvested and the amounts of cadmium element in stem and leaf organs together with the growth parameters were measured. This study determines the amount of cadmium accumulated in Platanus occidentalis. The respective cadmium concentrations in the root, leaf, and stem in site 1 were 382, 98, and 87; in site 2 they were 591, 122, and 94; and in site 3 they were 633, 151, and 104 mg/kg dry weight (DW). Furthermore, the comparison between accumulation and transfer of cadmium in the study showed more absorption of this metal by the root than that by the stem and leaf. The result of this research shows that buttonwood has the potential for cadmium accumulation without any serious damage to its growth. To control the extent of contamination in industrial areas, petrochemical industries, power plants and vast contaminated municipal areas, there is a great need for planting plants like buttonwood.

Investigation of heavy metal pollution of trees in a contaminated industrial area in the north of Iran

Phytoremediation is the technology of purging soils and water systems from heavy pollutant metals. Cadmium is one of the heavy elements, which is environmentally important due to its toxicity to humans and animals. Toxicity and accumulation of cadmium in body organs through eating contaminated food has an important role in endangering human's health. To this end, trees of buttonwood were prepared and irrigated with nutrient solution containing cadmium chloride in 10, 15 and 20 mM for 12 months. Then the root, stem and leaf samples were harvested and the amounts of cadmium element in stem, root and leaf organs together with the growth parameters were measured. This study determined the amount of cadmium accumulated by Platanus occidentalis. Furthermore, the comparison between accumulation and transfer of cadmium in the study showed that absorption of this metal by the root is more than its amount in stem and leaf. The result of this research shows that buttonwood has the potential for cadmium accumulation without any serious damage to its growth. Regarding the extent of contaminated industrial areas, petrochemical industry, power plants and vast contaminated municipal areas, there is a great need for planting fast-growing and tolerant plants like buttonwood.

Different morphologies of ZnO nanorods and their sensing property

Different morphologies of one-dimensional (1D) ZnO nanocrystals were successfully synthesized by hydrothermal process with cetyltrimethylammonium bromide (CTAB), sodium dodecyl sulfate (SDS) and polyethylene glycol (PEG) assisted. The morphology and structure of crystals were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) analysis. Gas sensors have been fabricated using the 1D ZnO crystals to examine the responses to NO 2 and CO gases over a range of operating temperature from 150 to 450 °C. The effect of surfactant and calcination condition, as well as morphologies obtained by different synthesized methods on sensing property were systematically investigated. The response of NO 2 was greatly enhanced from 239.5 to 470.0 by the addition of 5% cadmium element as dopant during CTAB-assisted low temperature hydrothermal process. The effect of Cd loading on the gas sensing property and the sensing mechanism were discussed.

Influence of Cadmium on the Growing Rate of the Zea Mays Seedlings Roots

SUMMARY Cadmium element influenced the roots growing, was found in the performed study; an inhibition of the growing, directly proportional wi th the concentration of the applied heavy metal was noticed. The study on the accumulation of some toxic elements at plants is very important, as measures are necessary to prevent the destruction of the terrestrial and aquatic ecosystems. (Onac, 2005). In the same time, the abs ence of some elements such as Copper, Cobalt, Manganese from the food of animals would lead to severe physiologic diseases (Maxim, 2008). The Dobrogean corn sort was used. In order to determine the radi cle system length growing, daily measuring was made, beginning from the 5 th day. The data were processed with the student T test. Analyzing the data on the roots growing rate from Tab.1, it is noticed that the growing rate was not uniform. T he highest growing rate was observed at the witness variant, followed by the S 2 variant with high grow during the 11-13 days inter val. At the S 3 variant, the highest was during the interval of 9- 11 days. The S 5 and S 6 variants had the highest rate in the interval of 5-7 days, and t hen recorded a regression. Tab.1

Scientific Serial

Wiedemantis Annalen der Physik, January.—Double refraction in glass plates vibrating transversely, by W. Konig. In a long glass plate or rod vibrating transversely, there is at the nodes double refraction of a peculiar kind. This has been subjected to a detailed experimental study, and the results discussed fully from the theoretical point of view. The author has been successful in obtaining photographic records of these phenomena, copies of which accompany the paper.—On the tones produced by vibrating sheets of gas in flames, by V. Henson. A photographic study of vibrating flames.—On the absorption of light in coloured glass, by R. Zgismondy. The colour of a glass, and hence its absorption spectrum, depends, not only upon the nature of the colouring material present, but also upon the composition of the colourless glass itself. Experiments were therefore carried out with twelve glasses of different composition, varying from pure sodium and potassium silicate on the one hand to pure lead silicate on the other. Borax and fused boron trioxide were also examined. The colouring oxides included the oxides of copper, chromium, cobalt, nickel, manganese, iron and uranium. For these glasses the constant A = E/gS was determined, where S is the specific gravity of the glass, g the number of milligrams of the colouring oxide per gram of glass, and E the extinction coefficient. The results are expressed graphically.—On the decrement of the electrical vibrations on the charging of condensers, by A. F. Sundell and Hj. Tallqvist. Although in many researches on damped vibrations the experimental figures for the time of oscillation agree well with those deduced theoretically, in the case of the decrement of these vibrations the agreement is either very rough, or there is no agreement at all. In the present series of experiments it is shown that if the necessary corrections are introduced, the experimental and theoretical results agree exactly.—On the melting point of gold, by L. Holborn and A. Day (see p. 330).—On the expansion of some metals at high temperatures, by L. Holborn and A. Day. The coefficients of expansion of platinum, palladium, silver, 20 per cent, platinum-iridium nickel, constantin, wrought iron and steel were determined for temperatures between 0° and 1000°C, where the melting-points allowed.—On the irregularity of the Weston cadmium element with 143 per cent, amalgam in the neighbourhood of 0° C, by W. Jaeger. It is shown that in the neighbourhood of 0° C. the irregular variations of this cell may amount to as much as two millivolts, although at 10° C. different elements agree to within a few tenths of a millivolt.—Communication to the knowledge of the phenomena in induction apparatus, by K. K. Johnson.—On surface tension, by H. Hulshof. The necessary existence of surface tension is deduced from the assumption of a continuous density variation in the capillary layer.—On the numerical relation between the two elasticity constants in isotropic media, according to the molecular theory, by W. Voigt.—On the electrical analogue to the Zeeman effect, by W. Voigt.—On the change of the form of vibration of light when propagated through a dispersive and absorbing medium, by W. Voigt.—Calculation of the conductivity of gases, by J. Stark.—A criticism of the mode of derivation of Wien's spectrum equation, by E. Jahnke, O. Lummerand E. Pringsheim.—On the history of telegraphy, by L. Lewin.