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Calcium hexagonal ferrite with zinc and nickel substitutions is prepared by using microwave assisted method of Sol-Gel auto combustion technique. The prepared compounds are found to be in single phase with W-type hexagonal structure of CaZn2Fe16O27, CaNiZnFe16O27 and CaNi2Fe16O27.Calcium Hexaferrites are known to have large values of coercivity Hc but it is observed that the substitution of Zinc and Nickel ions can alter coercivity without any significant change in magnetism. Hexagonal Calcium ferrites are of immense interest due to their attractive features which suit present day magnetics. [ABSTRACT FROM AUTHOR]

This research aims to prepare a nanocolloidal solution of gold by chemical reduction method by tri sodium citrate (TSC) as a reduction agent and using gold chloride as a source of gold ions in aqueous solution at low temperatures (room temperature) and applying the solution as a colorimetric sensor to detect some heavy metal ions. The prepared solution was diagnosed by Transmission electron microscope as well as the XRay Diffraction. The results showed that the shape of the prepared particles is spherical with diameters close to 10 nanometers and with good scattering. The ions of zinc, lead, iron, and copper elements were detected. The nanomaterial gave a very fast color response after adding ions to the solution. And through the results obtained, it is expected that this prepared material can be used in environmental applications. [ABSTRACT FROM AUTHOR]

It was found that during the electrolysis of zinc electrolyte, which contains a colloidal solution of nanodiamonds, a coating is formed on the steel surface by co-deposition of nanodiamonds with zinc ions. The dependence of the friction coefficient in the coating - steel triboconjugation on the concentration of nanodiamonds in the coating has been determined. In particular, the concentration of 5% nanodiamonds makes it possible to achieve the greatest (up to 0.09) decrease in the friction coefficient, while with a concentration of 0.5% nanodiamonds, the friction coefficient is 45% higher. It has been experimentally confirmed that the wear resistance of the coating monotonically increases with increasing concentration from 1% to 7%, which is due to the presence of functional groups in the hybrid zone of nanodiamonds and the passivation of interacting uncompensated σ-bonds during friction, which reduces the adhesion between tribo-conjugated surfaces. [ABSTRACT FROM AUTHOR]

Eggshells are a rich source of calcium and can be easily converted into biogenic hydroxyapatite for biomedical applications. This research aims to to fabricate hydroxyapatite (HA-Es) and 5 mol% zinc-substituted hydroxyapatite (5ZnHA-Es) dense bioceramic using initial powders synthesized from waste eggshells. The as-prepared powders were presureless sintered at 1250°C and after that their mechanical as well as cytotoxic properties were evaluated. TEM micrographs of the starting powders showed that HA-Es and 5ZnHA-Es particles have nano-rod shape and were highly agglomerated. For densification study, it was revealed that 5ZnHA-Es exhibited higher fracture toughness compared to zinc-free sample with 1.55 ± 0.06 MPa.m1/2. This enhancement of the fracture toughness was attributed to the presence of minor β-TCP phase when 5 mol% zinc ion was incorporated into HA, combined with enhanced densification at 1250°C. Cytotoxicity analysis through MTT assay analysis indicated that both HA-Es and 5ZnHA-Es were non-toxic. Nevertheless, the 5ZnHA-Es specimen showed more than 90% of cell viability after 24 h exposure in the MTT assay solution, compared to only 81% for HA-Es sample. This finding inferred that the presence of Zn ion may have promoted cells proliferation more effectively than HA-Es. This work had provided an insight on the feasibility of using natural calcium extracted from waste eggshells as starting material in the preparation of Zn-substituted HA, suitable for biomedical applications. [ABSTRACT FROM AUTHOR]

A new spectrophotometric method for the determination of zinc ions in some drugs was described. The method is based on the complexion reaction of zinc ions with a new reagent. The new reagent was synthesized from a diazonium reaction between Metoclopramide (MCP with (vitamin B6) to produce a new reagent named (5-chloro-N-(dimethylamino) ethyl)-4-(5-hydroxy-3,4-bis(hydroxymethyl)-6methyl pyridine-2-yl) diazeenyl)-2-methoxybenzamide) or termed (BMAZ). The reagent was reacted with trace amount of zinc ions at PH=6 to give an orange-colored solution. The method was simple, rapid, sensitive, selective, accurate and the final orange solution was shown a maximum absorption at 556 nm. Beers law was obeyed in the zinc ions concentration range of (0.075 – 1 µg/ml) with a molar absorptivity (1*10−3 L.mol−1.cm−1) and Sandell's sensitivity (4.54*10 5μg.cm−2) limit of detection (LOD) and limit of quantification are (0.003) µg/ml and (0.01) µg/ml, respectively. The charge of the complex was determined by passing it on a positive and negative ion exchanger and found that the complex is positively charged. It was found that the ions do not interfere when using this reagent because it is only selective for the two ions of zinc and mercury, and when studying reagent with mercury, it was found that the reagent reacts with mercury at different conditions such as pH and solvent. All of the optimum conditions of the method and the properties of the new reagent were studied such as pH of the reaction, the volume of the chemical reagents, and all other necessary conditions. The method was applied to determine the trace amount of zinc ions in some drugs and the method shows accuracy with recovery percentage between (RSD %=0.34, E%=-0.75, Rec%=100.13). [ABSTRACT FROM AUTHOR]

In this project, inhibitor Nano complex of zinc ion (II) with theophylline [Zn(THP)2 (H2O)4] was prepared by sonochemical method according to the modified process. The average particle size of Nano-Synthesized was 22 nm according to transmission electron microscopy (TEM). Electrochemical performance of varying inhibitor Nano complex concentrations on mild steel corrosion in hydrochloric acid (HCl) at various temperatures were studied. As a studied in corrosion methods by weight loss and polarization, it was found that it is indeed a good and effective inhibitor that limits various corrosion processes and has high efficiency at low temperature 35°C and 200 ppm. Moreover, the thermodynamic parameters such as activation energy (ΔE), entropy (ΔS), enthalpy (ΔH), and the free energy (ΔG) of adsorption follow the Langmuir isotherm. [ABSTRACT FROM AUTHOR]

The effects of impurity on the growth of crystal have been the reported by many investigators. In the present study, the effect of small amount of zinc in the solution of crystallization of struvite-K crystals was studied using the SEM, FTIR and EDAX spectroscopic techniques. It was found that, the concentration and volume of zinc ions transform the morphology of struvite-K crystals. However in FT-IR spectroscopy, the vibrational frequencies observed from pure and zinc doped struvite-K crystals, the zinc doped frequencies were found to be slightly different from pure struvite-K crystals. The observed change in the vibrations of zinc doped was due to influence of zinc ions. EDAX techniques revealed that the sample was of a mixed composition. [ABSTRACT FROM AUTHOR]

Increasing demand for zinc (Zn) encourages intensive studies in the field of exploration of new resources. One of the potential secondary resource of Zn is electric arc furnace (EAF) dust. Prior studies regarding element recovery from EAF dust involved the leaching process using lixiviant at ambient and elevated temperature. In general, most lixiviants possessed disadvantage including high concentration and high pulp density requirement, unselective metal recovery and risk to the environment. One of the chemicals could be proposed to solve the problems is glutamic acid. In the form of sodium salt (monosodium glutamate or MSG), the amino acid could be applied as a selective and as powerful ligand to bind Zinc ion. In this study, MSG would be tested for zinc recovery from EAF dust. The effect of leaching parameters such as pH, lixiviant concentration, pulp density and leaching time would be monitored. [ABSTRACT FROM AUTHOR]

Using the new method of direct matrix analysis, the wavelengths of transitions of Fe2+ ions in ZnS were determined. The obtained theoretical numbers of the spectral bands of luminescence coincide with the numbers obtained in previously performed experimental studies, which confirms the correctness of the chosen method of calculation. The developed method makes it possible to purposefully choose from the entire array of transitions in AIIBVI materials doped with iron group ions most suitable for developing IR lasers with the required wavelength and spectral characteristics of the radiation, tunable over a wide range of wavelengths. [ABSTRACT FROM AUTHOR]

In the present work, investigations of structural, magnetic and induction heating properties of surface functionalized zinc ferrite nanoparticles were carried out successfully. The zinc ferrite nanoparticles were prepared by coprecipitation route and further functionalized with oleic acid. The room temperature X-ray diffraction pattern confirmed the typical cubic spinel structure of the prepared nanoparticles. The average crystallite size calculated from Scherrer’s formula was found to be 12.30 nm confirming the nanocrystalline nature of zinc ferrite nanoparticles. The characteristic peaks observed in FT-IR spectrum confirmed the formation of cubic spinel structure and oleic acid coating over zinc ferrite nanoparticles. The room temperature magnetization behaviour revealed the superparamagnetic nature of the prepared nanoparticles. The induction heating behaviour shows a desirable amount (6 mg/mL) of zinc ferrite nanoparticles can able to achieve 42°C temperature for 600 s at 4.0 kA/m. This indicates that the resulting zinc ferrite nanoparticles are promising materials in magnetic hyperthermia treatments. [ABSTRACT FROM AUTHOR]

A new series of Er3+ ions doped zinc bismuth borate glasses have been prepared to evaluate and optimize the structural and spectroscopic properties for photonic applications. The physical properties have been determined using density (ρ) and molar volume (VM) values. The structural properties like, boron–boron separation (dB–B), oxygen packing density (OPD) values were evaluated for the interpretation of physical and structural properties. The visible luminescence spectra exhibit strong 4S3/2→4I15/2 emission transition and weak ²H11/2→4I15/2 emission transition corresponding to the band positions at 552 and 534 nm respectively under 488 nm excitation. The Judd-Ofelt (JO) theory has been applied to interpret the local environment of the Er3+ ions site and covalency of the Er–O bond. The various lasing parameters such as stimulated emission cross-section (σEP) experimental and calculated branching ratios (βR) and radiative lifetime (τcal) have been calculated for the 4S3/2→4I15/2 emission transition. The CIE color coordinates of the prepared glasses lay in the green region of the chromaticity diagram thus suggest the fact that intense green emission can be achieved from the Er3+ doped zinc bismuth borate glasses. [ABSTRACT FROM AUTHOR]

Trivalent Sm3+ ions doped Zinc Telluro-borate glasses have been synthesized following the melt quenching technique and their spectroscopic properties were studied through XRD, FTIR, optical absorption and emission spectra. The fundamental stretching vibrations of various borate and tellurite networks were identified through FTIR spectra. Bonding parameters and Judd-Ofelt intensity parameters have been evaluated from the absorption spectra. From the luminescence spectra along with JO parameters, important radiative parameters such as transition probabilities (AR), branching ratios (βexp) and stimulated emission cross-sections (σEP) for all the observed emission transitions were calculated. Among the prepared glasses, 0.75SZTB glass exhibits higher βR and σEP values for the 4G5/2→6H7/2 transition of the Sm3+ ions thus suggests its suitability for the realization of reddish-orange visible lasers. [ABSTRACT FROM AUTHOR]

Layered double hydroxides containing Zn2+ and Al3+ ions with formula [Zn1-xAlx(OH)2]x+[(NO3-)x/2xmH2O] has been prepared using coprecipitation method at pH 10 to form Zn/Al layered double hydroxides (LDH). Zn/Al LDH then intercalated with Keggin ion of [α-PW12O40]3- to form intercalated Zn/Al LDH. Materials were characterized using X-Ray and IR analyses. Zn/Al LDH and intercalated Zn/Al was applied as adsorbent of Cd(II) using batch system. Analysis of X-Ray and IR on Zn/Al LDH and intercalated Zn/Al with [α-PW12O40]3- showed that synthesis of Zn/Al was successfully conducted which was indicated from diffraction at 11 deg and vibration at around 400-500 cm-1 for Zn-O and Al-O vibrations. Analysis of pH PZC on LDH showed that materials have pH PZC at 5. Adsorption of Cd(II) on Zn/Al LDH and intercalated Zn/Al LDH with [α-PW12O40]3- at showed that intercalated Zn/Al LDH with Keggin ion of [α-PW12O40]3- has higher adsorption capacity than Zn/Al LDH without intercalation. [ABSTRACT FROM AUTHOR]

Zinc ion (Zn2+) is an essential cofactor required by numerous metalloenzymes and is important for structural and regulatory systems in bacterial cells. Zn2+ is a trace element: bacterial cells require only very small quantities. High concentrations of Zn2+ are toxic to microorganisms. In the environment, bacteria may be subject to conditions where Zn2+ is either very limited or s at a toxic level. Due to the limitation of Zn2+ or the toxic effect of high levels of free Zn2+ ions, the bacteria need to carefully control the intracellular level of Zn2+. This paper aims to determine the mechanisms bacteria use to maintain the intracellular Zn2+ concentration and the adaptation mechanisms used by bacteria to grow in a Zn2+-limited environment. The role of Zn2+ in bacterial pathogenesis and virulence capacity will also be discussed. It is known that in bacteria, Zn2+ homeostasis is maintained by Zn2+-uptake/import and Zn2+-efflux/export systems. These two systems provide a balance between the requirement for the metal and its toxicity and therefore is essential for bacterial growth and survival. Metal ions, including Zn2+ have been demonstrated to be involved in various bacterial pathogeneses. Moreover, there is increasing evidence for the importance of Zn2+ in the virulence of various bacteria. Zn2+ is shown to be involved in biofilm formation, bacterial motility, antibiotic resistance, and survival against oxidative stress. Therefore, the ability of bacterial cells to maintain a homeostasis of Zn2+ is crucial for their growth, survival and virulence capacity. [ABSTRACT FROM AUTHOR]

The research regarding the properties of thin films of hydroxyapatite doped with various ions such as zinc elaborated by spin-coating technique have rarely been fabricated and studies in recent years. In the present study Zn doped hydroxyapatite (ZnHAp) synthesized by a sol-gel method were coated on Ti substrates using a spin-coating technique. The thin films was characterized by Scanning Electron Microscopy (SEM) and Glow Discharge Optical Emission Spectroscopy (GDOES). The structural characterizations of ZnHAp thin films showed the presence of Zn and apatitic structure. The GD depth profiles revealed the successful embedding of the Zn ions in HAp structure. In addition, in vitro evaluation of the antifungal properties of ZnHAp demonstrated the potential antifungal effect of ZnHAp thin films against Staphylococcus aureus 0364 biofilm. [ABSTRACT FROM AUTHOR]

The influence of zinc doping on the gel grown calcium hydrogen phosphate dihydrate crystals was studied using the spectroscopic techniques, which included SEM, FTIR and EDAX. It was found that, zinc ions transform the morphology of brushite crystals from rectangular plate shaped crystals to branching microcrystal patterns. However in FT-IR spectroscopy, as compared to undoped brushite crystals few vibrations were shifted to higher value. The observed changes in the vibrations were due to the impact of zinc ions. EDAX techniques is use to determine the percentage composition of elements present in the doped crystals. It revealed that the sample was of a mixed composition. [ABSTRACT FROM AUTHOR]

Zinc hydrogen phosphate (ZnHP) single crystal co-doped with divalent transition metal ions Cobalt (Co2+) and Cadmium (Cd2+) is grown by gel technique in silica hydro gel media. The presence of Co2+ and Cd2+ dopants in the ZnHP crystal was confirmed by Energy Dispersive X-ray Analysis (EDAX).FTIR spectra of the grown crystal depict the stretching and bending vibration of PO4 units, water of crystallization and metal-oxygen bonds. Powder XRD analysis reveals that the grown crystal belongs to monoclinic system with spacegroup P 21. The thermal stability of the grown crystal is rectified from TG-DSC studies. [ABSTRACT FROM AUTHOR]

Coal fly ash (CFA), which is a solid waste generated in large amounts worldwide, is mainly composed of some oxides having high crystallinity, including quartz (SiO2) and mullite (3Al2O3 2SiO2), and unburned carbon as a mesopore material that enables it to act as a dual site adsorbent. To decrease the crystallinity, CFA was modified by sodium hydroxide treatment. The modified fly ash (MFA) contains lower amount of Si and Al and has a higher specific surface area than the untreated fly ash (CFA). The objective of this study is to investigate the competitive adsorption of Pb2+ and Zn2+ from aqueous solutions by CFA and MFA. The effect of pH, contact time and initial concentration was investigated. Effective pH for Pb2+and Zn2+ removal was 4. A greater percentage of Pb2+and Zn2+ was removed with a decrease in the initial concentration of Pb2+and Zn2+. Quasi-equilibrium reached in 240 min. [ABSTRACT FROM AUTHOR]

The ability of activated carbon prepared from rice husk (RH), oil palm empty fruit bunches (EFB) and mixture (Mix) activated carbon in adsorption of Zinc (Zn2+) from aqueous solution was investigated. The Mix activated carbon has prepared from mixture of RH and EFB activated carbon with weight ratio (1:1) The RH and EFB activated carbon were produced by using sodium hydroxide (NaOH) as a dehydrating agent in chemical activation process. EFB activated carbon showed excellent efficiency in removing Zn2+ with their percentage removal up to 100% even at low adsorbent dosage. The study also showed that the adsorption of Zn2+ by EFB, RH and Mix activated carbon is dependent on the adsorbent dosage and initial metal concentration. The adsorption isotherms of the Zn2+ of EFB, RH and Mix activated carbon were determined and compared with Langmuir and Freundlich models. It was showed that Langmuir model was more favorable for RH and Mix activated carbon with correlation coefficient (R²) value is 0.9958 and 0.9847. In contrast, EFB activated carbon was more favorable to the Freundlich and Langmuir model with correlation coefficient (R²) are 0.9967 and 0.9967. [ABSTRACT FROM AUTHOR]

The ability of activated carbon prepared from rice husk (RH), oil palm empty fruit bunches (EFB) and mixture (Mix) activated carbon in adsorption of Zinc (Zn2+) from aqueous solution was investigated. The Mix activated carbon has prepared from mixture of RH and EFB activated carbon with weight ratio (1:1) The RH and EFB activated carbon were produced by using sodium hydroxide (NaOH) as a dehydrating agent in chemical activation process.EFB activated carbon showed excellent efficiency in removing Zn2+ with their percentage removal up to 100% even at low adsorbent dosage. The study also showed that the adsorption of Zn2+ by EFB, RH and Mix activated carbon is dependent on the adsorbent dosage and initial metal concentration. The adsorption isotherms of the Zn2+ of EFB, RH and Mix activated carbon were determined and compared with Langmuir and Freundlich models. It was showed that Langmuir model was more favorable for RH and Mix activated carbon with correlation coefficient (R²) value is 0.9958 and 0.9847. In contrast, EFB activated carbon was more favorable to the Freundlich and Langmuir model with correlation coefficient (R2) are 0.9967 and 0.9967. [ABSTRACT FROM AUTHOR]

Biosorption of zinc ion by non-living macrophytes, Utricularia aurea (U. aurea) is one of the common suspended aquatic species in Asia. The percentage of zinc removal was identified by conducting experiment under batch studies. In this study, the pH used ranged from pH 2, 4, 7, and 9, the time contact were 30, 60, 90 and 120 minutes while the biosorbent sample size ranged from 150 μm, 300 μm, 450 µm and 600 µm at an agitation speed of 125 rpm. From the result, the best size sample for zinc removal was 450 μm with pH 4 at 120 minutes of contact time. The zinc ion was efficiently removed at 87%. Atomic Adsorption Spectrometer (AAS) was used to analyze the heavy metal removal. The result is then compared with the Environment Quality Act 1974 whether the biosorbent is efficient in removing zinc in wastewater treatment plant. [ABSTRACT FROM AUTHOR]

This paper elaborates the effects of cationic disorder on structural, microstructural and magnetic properties of the Zn0.34Co0.66Fe2O4 nano-particles, synthesised by solvothermal method followed by annealing at 1000 °C. The Rietveld refinement of XRD data reveals that nanoparticles are crystallized in spinel structure with Fd-3m space group. The refinement process reveals that the lattice parameter decrease from 8.392 A to 8.373 A and Zn2+ ions migrate from octahedral to tetrahedral sites on annealing. Comparison of FESEM microstructures reveals that particle size increase from 30 nm to 200 nm and morphology of the particles changes from spherical to rhombohedral after subjecting them to annealing at 1000°C. The magnetic data analysis shows that magnetization improves significantly from Ms = 47 emu/g to Ms = 64 emu/g at 300 K where as magnetocrystalline anisotropy and coercivity reduces upon annealing. The change in magnetic parameters on annealing is strongly correlated to redistribution of Zn2+ cations on different sites. [ABSTRACT FROM AUTHOR]

The biosorption of Zinc (II) ions onto a biomaterial - Luffa cylindrica has been studied. This biomaterial was characterized by elemental analysis, surface area, pore size distribution, scanning electron microscopy, and the biomaterial before and after sorption, was characterized by Fourier Transform Infra Red (FTIR) spectrometer. The kinetic nonlinear models fitted were Pseudofirst order, Pseudo-second order and Intra-particle diffusion. A comparison of non-linear regression method in selecting the kinetic model was made. Four error functions, namely coefficient of determination (R²), hybrid fractional error function (HYBRID), average relative error (ARE), and sum of the errors squared (ERRSQ), were used to predict the parameters of the kinetic models. The strength of this study is that a biomaterial with wide distribution particularly in the tropical world and which occurs as waste material could be put into effective utilization as a biosorbent to address a crucial environmental problem. [ABSTRACT FROM AUTHOR]

Structure and optical homogeneity of LiNbO3:Zn (0.03-4.5 mol.%) crystals were searched by photoinduced light scattering and by Raman spectroscopy. The photorefractive effect depends on Zn2+ concentration nonmonotonically. Decrease of photorefractive effect is explained by decrease of structure defects with localized electrons. The Zn2+ cations replace structure defects NbLi and LiNb, trapping levels appear near the bottom of the conduction band and photo electrons recombine with emission under laser radiation. By the Raman spectra the area of the high structure order is found. In this area the own alternation, the alternation of impurity cations and the vacancies along the polar axis is almost perfect. [ABSTRACT FROM AUTHOR]

Metal salphen family has been extensively studied over the past few years and has been reported to be good DNA stabilizers due to its high binding affinity. Binding studies of metal complex with DNA are useful for understanding the interaction mechanism and to provide an insight about the application and design of a novel effective drug target to DNA. In this study, a bis-zinc (II) salphen metal complex derived from 4-methyl-2,6-diformylphenol and 1,2-diaminobenzene (H2L) via condensation reactions has been synthesised. The zinc(II) macrocyclic complex is characterised using standard spectroscopic and structural techniques such as ¹H NMR spectroscopy and FTIR spectroscopy. The binding interaction between the synthesised metal complex with calf thymus-DNA (ct-DNA) has been investigated by preliminary UV/Vis DNA study. From the preliminary UV/Vis DNA study, it shows that Bis-Zn(II) salphen complex has interaction with ct-DNA. [ABSTRACT FROM AUTHOR]

We have fabricated highly sensitive and Cl2 selective flexible sensor by depositing solution processed zinc phthalocyanine nanowires onto the flexible PET substrate and studied its Cl2 sensing characteristics in Cl2 concentration range 5-1500 ppb. The flexible sensor has a minimum detection limit as low as 5 ppb of Cl2 and response as high as 550% within 10 seconds. Interestingly, the sensor exhibited enhanced and faster response kinetics under bending conditions. The gas sensing mechanism of sensor has been discussed on the basis of XPS and Raman spectroscopic studies which revealed that zinc ions were the preferred sites for Cl2 interactions. [ABSTRACT FROM AUTHOR]