Min Immersion Time Research Articles

Morphological and Electrical Properties of gold nanoparticles /macroPorous Silicon for CO2 Gas

In this work, the fine structure macro-porous silicon (macroPS) substrate was prepared by photo-electro-chemical etching of n-type silicon wafer. Ultraviolet illumination condition of wavelength 360nm wavelength and intensity of about 100mW/cm2 with etching current density of about 50 mA/cm2 and etching time 5 min was employed. The Hybrid device gold nanoparticles /macroPorous Silicon (AuNPs/macroPS) was fabricated by deposition AuNPs into mPS substrate Via immersion plating process of macroPS in the solution of HAuCl4 with the (10-3M) concentration and 2min immersion time. The characteristics of PS before and after immersion process were investigated by scanning electron microscopy (SEM), EDS, X-Ray diffraction (XRD), photoluminescence (PL) and Infrared spectroscopy (FTIR). The J-V characteristics of sandwich structure showed that the maximum sensitivity of the AuNPs/macro PS was about (90.5%)for compared with macro-PS substrate. The current-voltage characteristics were performed in primary vacuum with a base pressure of about 0.2mbar and CO2 with 1mbare concentrations. Significant enhancement was observed in sensitivity of the AuNPs/macroPS hybrid device and temporal response after deposition the AuNPs.

RETRACTED ARTICLE: Development and characterization of hot dip aluminide coated stainless steel 316L

Stainless steel (SS) grade 316L is used for orthopedic implants due to its biocompatibility; yet the effort should be done to minimize the carcinogenic and inflammatory effects related to SS 316L implants. In this research, aluminide coating of Al–Si alloy on SS 316L is characterized by using optical microscopy, energy dispersive spectroscopy (EDS), nano-indentation and corrosion testing technique. Hot dip aluminizing process is used to coat the SS 316L specimens at 765 °C for 2 min immersion time. Half of the specimens are also diffusion treated in a Muffle furnace at 550 °C for 4 h to produce diffused specimens of SS 316L. Microstructural examination shows the formation of flat coating/substrate interface due to Si addition. EDS analysis confirms the formation of complex intermetallic at the coating/substrate interface which finally results in increasing the hardness and corrosion resistance properties of coating.

Optimization of AgNPs/mesoPS Active Substrates for Ultra–Low Molecule Detection Process

In this study, the effects of the sizes of AgNPs and the resulting hotspot nanogaps on the SERS spectra have been studied extensively. The optimal condition of AgNPs/mesoPS active substrate for efficient, high reproducibility and excellent stability was obtained at lowest nanogaps. The maximum EFs of about 1.4 × 105 and 1.2 × 105 were obtained for 10− 5 M Cy3 dye solution concentration at two average AgNP sizes of (282.95 and 338.1) nm and corresponding average nanogaps of (22.28 and 26.43) nm respectively. The better reproducibility with minimum variation of SERS intensity of about (14%) after six month aging in air was obtained for more uniform AgNPs deposited on mesoPS surface with peak nanogaps of 10 nm at 8 min immersion time. The detection limit for Cy3 dye molecules adsorbed on AgNPs/mesoPS active substrate prepared at 8 min has been evaluated as 10− 14 M and the high EF of about 5.3 × 1012 was obtained when using this concentration.

Effect of different immersion times and sintering temperatures on translucency of monolithic nanocrystalline zirconia

PurposeThe objective of the study was to investigate the effect of different immersion times, in coloring liquid, and sintering temperatures on translucency of monolithic nanocrystalline zirconia. Materials and methodsForty five specimens of nanocrystalline zirconia were obtained by cutting InCoris TZI blocks into slices using a stainless steel disc mounted on a custom made milling machine. The slices were divide into three groups (n = 15) according to immersion times (3,5 and 7 min) then each group was further subdivided into 3 subgroups (n = 5) according to the sintering temperatures (1400°c, 1500°c and 1600°c). CIE-Lab coordinates were measured for each slice against black and white backgrounds using Vita easy shade spectrophotometer and translucency parameter (TP) was calculated. One way analysis of variance combined with a Tukey-post hoc test were used to analyze the data obtained (P = 0.05). ResultsResults of the present study showed that at temperature 1400°c there was statistically significant decrease in TP between 7 min immersion time and the other two groups, while there was no statistically significant difference in TP using different immersion times at temperatures 1500°c and 1600°c. ConclusionOur results showed that the best translucency was obtained by the combination between lower dipping times and higher sintering holding temperatures.

Inhibition of Filiform Corrosion on Organic-Coated Magnesium-Containing Galvanized Steel By Smart-Release Ion Exchange Pigments

Zinc-(1-2 w%) Magnesium-(1-2 w%) Aluminium coated galvanized steel presents a superior corrosion resistance over conventional galvanized steel as a result of the Al and Mg additions to the bulk composition of the coating. It has been previously demonstrated that cathodic delamination does not occur on organically-coated ZMA galvanized steel due to the unfavourable potential gradient formed between the intact interface and the defect. Contrary, the potential at the intact interface is more negative than the potential at the defect thus triggering anodic undermining in the form of filiform corrosion. Smart-release exchange pigments have been proven to be a promising approach towards the suppression of undermining corrosion. In the current research, the ability of hydrotalcite (HT) based pigments on the inhibition of induced filiform corrosion on organic coated ZMA galvanized steel has been investigated. This paper describes a systematic kinetic study on the inhibitory effect of anion exchange HT-based pigments on filiform corroding hot dipped Zn-(1-2 w%)Mg-(1-2 w%)Al galvanized steel. The samples were alkaline degreased in 1M KOH and 1M NaOH at 70oC and 3 min immersion time and were coated with a model organic coating of 15.5% PVB containing the exchange pigments via bar casting. Filiform corrosion was then initiated via scribing the samples and introducing a corrosive electrolyte in the defect. The kinetics of filiform corrosion were followed by optical recording over a period of six weeks. It is positively demonstrated that the addition of smart-release pigments in the organic coating greatly suppresses the rate of filiform corrosion. The inhibitory effect of the pigments has been further investigated by systematically varying the volume fraction of the pigment on the organic coating presenting the reduction of filiform corrosion rate with respect to the concentration of the pigment in the organic coating. The effect of anion exchange HT-based pigments on filiform kinetics is analysed and described in terms of an inhibition mechanism.

Evaluation of the etching and chrome plating on the ABS, PVC, and PVC/ABS blends surface

ABSTRACTAs replacement for acrylonitrile‐butadiene‐styrene (ABS), which is commonly used in the manufacture of chrome parts, polyvinyl chloride (PVC) and PVC/ABS blend parts were produced by injection process, etched in sulfochromic solution in different concentrations, immersion time, and temperature, and they were subsequently chrome‐plated by conventional method. After etching, the sample surfaces were analyzed by Scanning Electron Microscopy (SEM), Atomic Force Microscopy (AFM), roughness, and contact angle, and compared with the ABS surface. The metal deposition was assessed by visual inspection and adhesion test. The roughness influenced the adhesion of the metal layer directly. The chemical etching increased the surface wettability. To achieve a good metal layer adhesion, higher temperatures, immersion time, and etching solution concentration were necessary. A concentration of 350 g/L chromic acid and 400 g/L sulfuric acid, a 70 °C temperature and a 15 min immersion time resulted in good adhesion in PVC and PVC/ABS blends. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 44571.

Hurdle technology for minimally processed radishes: a response surface methodology approach

Response surface methodology was used to determine the optimum processing conditions that yielded maximum vitamin C content, minimum discoloration and minimum polyphenoloxidase activity after 4 days of refrigerated storage of minimally processed radishes. Ascorbic acid (0–2 %), sodium chloride (0–1 %) and immersion time (0–2 min) at 50 °C were the factors investigated related to polyphenoloxidase activity (PPO), vitamin C (VITC) and total color difference (ΔE). Experiments were conducted according to a Box-Behnken Design with three factors at three different levels. For each response, second order polynomial models were developed using multiple linear regression analysis. Analysis of variance (ANOVA) was performed to check the adequacy and accuracy of the fitted models. The response surfaces showing the interaction of process variables were constructed and analyzed. Based on desirability function, optimum operating conditions were found to be 2 % of ascorbic acid, 0 % of NaCl and 1.5 min of immersion time at 50 °C. At this optimum point, relative PPO activity, relative VITC content and ΔE values were 0.218, 3.227 and 4.929, respectively.

An Evaluation of the Solubility of Four Endodontic Sealers in Different Solvents (An In Vitro Study)

Background: Complete removal of filling material from the root canal is an essential requirement for endodontic retreatment. The purpose of the present study is to evaluate and compare the dissolving capabilities of various solvents (Xylene, Eugenate Desobturator, Eucalyptol, EDTA and Distilled water (as a control)) on four different types of sealer (Endofill, Apexit Plus, AH Plus and EndoSequence bioceramic sealer). Materials and method: Eighty samples of each sealer were prepared according to the manufacturers' instructions and then divided into ten groups (of 8 samples) for immersion in the respective solvents for 2 and 5 min immersion periods. Each sealer specimen was weighed to obtain its initial mass. The specimens were immersed in the tested solvents for 2 and 5 min, followed by rinsing with double distilled water and blotted dry with an absorbent paper, then they were reweighed to determine its final mass. The mean of weight loss was determined for each material in each solvent during the specified immersion period, and the values were subjected to statistical analysis. Results: Clear differences were shown in the solubility profile of these root canal sealers in the tested solvents. The result of the present study shows that Xylene had the greatest capacity for dissolving Endofill, Apexit Plus and AH Plus. Eugenate Desobturator, Eucalyptol and EDTA showed a highly significant dissolving capability on these sealers with variations between these subgroups; EndoSequence BC sealer is insoluble in these tested solvents. Regarding the immersion time, higher values of solubility were obtained at 5 min than that at 2 min immersion time. Conclusion: The results showed that Xylene, Eugenate Desobturator, Eucalyptol and EDTA can be used for the removal of Endofill, Apexit Plus and AH Plus during endodontic retreatment with variations between these subgroups; D.W (control group) showed the least capacity for dissolving these sealers. EndoSequence BC sealer is insoluble in the tested solvents.

The Effect of Immersion Time and Immersion Temperature on the Corrosion Behavior of Zinc Phosphate Conversion Coatings on Carbon Steel

The formation and corrosion performance of zinc phosphate coating on carbon steel at different temperatures and immersion times was studied. The corrosion performance of coatings was investigated using potentiodynamic polarization and electrochemical impedance spectroscopy. The characterization and composition of coatings were studied by SEM and EDS analysis. The corrosion resistance in 3.5%wt. NaCl solution was increased in the presence of zinc phospoate conversion coatings. The effect of immersion time and coating temperature were studied on anti-corrosion behavior of coatings. Coating temperature showed a significant effect in phosphate conversion coating and higher corrosion resistance was obtained with 45 oC operating temperature. Also the experimental results indicated that the corrosion resistance increased with increasing the immersion time. This behavior can be related to the increase of the phosphate coating continuity which formed on the surface. Surface analysis results indicated that the coating obtained from 20 min immersion time was more uniform and continuous.

Mechanical Properties of All-Cellulose Composites Made from Pineapple Leaf Microfibers

Pineapple leaf microfibers were firstly prepared using steam explosion, and all-cellulose composites were subsequently prepared using a surface selective dissolution process with the solvent of lithium chloride and N,N-dimethylacetamide (LiCl/DMAc). Mechanical properties and surface morphology of all-cellulose composites with immersion times of pineapple leaf microfibers in the solvent of LiCl/DMAc were investigated using tensile testing and scanning electron microscopy, respectively. The tensile strength of the all-cellulose composites with 120 min-immersion time was approximately 28 times higher than that of the pineapple leaf microfiber mats. These biocomposites made from pineapple leaf microfibers could be one of the potential alternatives to replace glass fiber reinforced composites.

Optimization of osmo-vacuum drying of pear (Pyrus communis L.) using response surface methodology

In the two-stage optimization of the osmotic dehydration and vacuum drying of the pear slices using response surface methodology, using face-centred central composite design (FCC), it was shown that the independent variables for osmotic dehydration were temperature (25–55 °C), solution concentration (50–70 % w/w), and immersion time (60–120 min) and for vacuum drying were vacuum pressure (10–30 kPa), drying temperature (50–70 °C) and drying time (180–300 min). Statistical analysis of results showed that the linear terms of all process variables in both stages have a significant effect on the responses. The second-order polynomial models for all response variables were found to be statistically significant with high values of R2 (>0.8). The optimum osmotic dehydration conditions for maximum water loss, minimum solute gain and maximum weight reduction were: 55 °C temperature, 50 % sucrose solution concentration, and 115 min immersion time. Dehydrated pear slices at optimized osmotic dehydration conditions were then subjected to vacuum drying. Optimum drying conditions of 10 kPa vacuum pressure, 55 °C temperature and 250 min drying time were established for vacuum drying of pear. At this optimum point, moisture content (MC), rehydration ratio and shrinkage were found to be 23.26 % (w.b.), 1.46 and 67.45 %, respectively. Separate validation experiment was conducted at the derived optimum conditions to verify the predictions and adequacy of the models. Two-stage optimization led to obtaining the best condition for production of dried quince slices with lowest MC, and shrinkage.

Detection of Malathion Resistance in Hyalomma anatolicum anatolicum from Bathinda District, Punjab.

Objective:The resistance status against malathion in Hyalomma anatolicum anatolicum ticks collected from Bathinda district, Punjab, was evaluated by adult immersion test (AIT).Materials and Methods:Technical grade malathion was used for conduction of AIT with 2 min immersion time protocol. The regression graph of probit mortality of ticks was plotted against log values of increasing concentrations of malathion and was utilized for the determination of slope of mortality, LC50, LC95 (95% confidence interval [CI]) and resistance factor (RF). The reproductive parameters of treated ticks viz. egg mass weight, reproductive index (RI), and percentage inhibition of oviposition (% IO) were also studied.Results:The increasing concentration of malathion showed an upward trend in per cent tick mortality. The slope of mortality (95% CI) was 2.489 ± 0.719 (2.489 ± 0.719) and value of goodness of fit (R2) was 0.799. The LC50 (95% CI) and LC95 (95% CI) values were recorded as 9099.2 (8378.6–9881.7) and 41,511.3 (35,060.2–49,149.4) ppm, respectively, with RF as 16.60 indicating level II resistance status. A negative dose-dependent slope of egg mass weight (−91.79 ± 25.15 [−171.8 to −11.76]) was recorded as the survived ticks laid significantly (P = 0.0355) fewer eggs. The mean RI of treated ticks decreased with increasing concentrations of drug and the slope (95% CI) was −0.293 ± 0.059 (−0.482 to −0.105). Further, a dose-dependent significant increase (P = 0.0157) in the mean % IO was recorded in treated ticks.Conclusions:The results of the current study would be useful in the formulation and implementation of effective tick strategies in the region.

Response Surface Methodology of Glutamine, Asparagine and 2,4- Dichlorophenoxyacetic Acid for Agave americana L. Embryo Number and their Optimization in a RITA® Automatic Bioreactor System

Response surface methodology was used to investigate the effect of different concentrations of 2,4-dicholorophenoxyacetic acid (2,4-D), asparagine and glutamine on a number of embryos from callus of Agave americana L generated with 0.5mg/L of 2,4-D, treatments obtained according to an experimental design with response surface Box-Behnken with three repetitions at the central point with 0, 1 and 2 mg L -1 2, 4-D; 0, 200 and 500 mg L -1 glutamine and 0, 500 and 1000 mg L -1 asparagine. The embryo number was optimized using the RITA® automatic bioreactors system using a Programmable Logic Controller (PLC) and a Light Dependent Resistor (LDR) varying the immersion frequencies with similar solid and liquid treatments at the same time for comparative purposes. The results showed that interaction between asparagine and glutamine had a statistically significant effect and the largest embryo number was obtained with the higher concentration of the two amino acids, the coefficient of determination (R2) calculated from the validation data for RSM model was 0.92, The use of the RITA® bioreactor had a positive effect on embryo number at 1 min of immersion time and a frequency of 12 times a day comparing with the liquid system but not at others frequencies, possibly because of the physical conditions inside the reactor. Response surface design was an experimental strategy which led to raise the embryo number using asparagine and glutamine as supplement of MS medium in the callus differentiation A. americana L. and using the RITA reactors automatic system was effective to improve the multiplication rate.

Crystalline ha coating on peek via chemical deposition

• Hydroxyapatite crystalline particles successfully chemically deposited on PEEK. • All process was done in room temperature and eliminates subsequent sintering. • Three dimensional porous treated layer were produced via this method. Polyether ether ketone (PEEK) has a similar elastic modulus to bone and can be a suitable alternative to metallic implants. However, PEEK is bioinert and does not integrate well with the surrounding tissues. The current commercial method for solving this problem is by coating PEEK substrates with calcium phosphates via plasma spraying. However, this method produces a low bonding strength between the substrate and the coating layer, as well as non-uniform density of the coating. In this study, chemical deposition was used to deposit HA crystalline particles on PEEK substrate without any subsequent crystallisation process therefore producing crystalline treated layer. EDX results confirmed the deposition of HA, and the XRD results confirmed that the treated layer was crystalline HA. FT-IR analysis confirmed the chemical bonding between HA and the substrate. Surface roughness increased from 24.27 nm to 34.08 nm for 3 min immersion time. The water contact angle showed an increase in wettability of the treated sample from 71.6 to 36.4 degrees, which in turn increased its bioactivity. The proposed method is a suitable alternative to other conventional methods as high temperature was not involved in the process which could damage the surface of the substrate.

Effect of cobalt electroless deposition on nickel hydroxide electrodes

The effects of cobalt additive on the positive electrode surface of nickel alkaline batteries are investigated. Electrode surface modifications by electroless cobalt deposits were made at different immersion times. The performance of nickel hydroxide electrodes was studied by optical techniques, such as scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDAX) and electrochemical methods as cyclic voltammetry, charge–discharge curves and electrochemical impedance spectroscopy (EIS). According to these results, electroless cobalt deposits obtained with 5 min of immersion time in the electroless-bath exhibit a better electrode performance.

Fabrication of an ultraviolet photoconductive sensor using novel nanostructured, nanohole-enhanced, aligned aluminium-doped zinc oxide nanorod arrays at low immersion times

Novel nanostructured thin-film arrays of nanohole-enhanced aligned aluminium (Al)-doped zinc oxide (ZnO) nanorods were prepared using sonicated sol–gel and immersion methods for metal–semiconductor–metal (MSM)-type ultraviolet (UV) photoconductive sensor applications. These nanorod arrays were grown on a glass substrate coated with ZnO nanoparticle thin film as a seed layer at immersion times ranging from 10 to 120min. Notably, the nanoholes appeared on the nanorods after the annealing process due to the evaporation of water and impurities. The photocurrent properties for the Al-doped ZnO nanorod arrays were significantly improved, increasing by more than five-fold compared to the seed layer when the sensor was illuminated with 365nm UV light at a density of 750μA/cm2. Interestingly, the highest responsivity using the Al-doped ZnO nanorod arrays was 1350.84A/W with an improved photocurrent-to-dark current ratio of 22.7, achieved for the samples prepared with a 50min immersion time and a gap between metal contacts of 0.07mm. Our results show that high-performance UV photoconductive sensors can be achieved using a novel structure of nanohole-enhanced aligned Al-doped ZnO nanorod arrays prepared at low immersion times which reduces fabrication time and cost.

Applying porous polyimide films in fibrous dye-sensitized solar cells

Fibrous dye-sensitized solar cells (DSSCs) were fabricated using porous polyimide films prepared by the phase inversion technique and their photovoltaic characteristics were investigated. A titanium wire was used as the photoelectrode substrate and a platinum wire as the counter electrode. The platinum wire was coated with a porous polyimide film to prevent direct contact between the two electrodes while facilitating electrolyte penetration through the pores. The pore size and pore size distribution of the porous polyimide films were controlled by varying the immersion time in nonsolvent. With increased immersion time, the pore size distribution gradually broadened as the pore size increased, enhancing electrolyte penetration. Increased electron transport owing to the enhanced electrolyte penetration resulted in enhanced photovoltaic performances of the fibrous DSSC. The fibrous DSSC with 60min immersion time had a short-circuit current density (Jsc) of 0.0372mA/cm2, an open-circuit voltage (Voc) of 0.182V, and a fill factor (FF) of 0.33.

Investigation of PEG adsorption on copper in Cu2+-free solution by SERS and AFM

The surface adsorption behavior of polyethyleneglycols (PEG), a wide-used additive in damascene copper plating, was investigated in acidic Cu2+-free electrolyte in the presence of PEG and Cl− by in situ surface enhanced Raman spectroscopy (SERS) and atomic force microscopy (AFM) under potentiostatic conditions. Both SERS and AFM studies indicate that the adsorption amount of PEG gradually increases within ∼30min immersion time at all the examined potentials prior to reaching steady status. It is demonstrated that, at relatively negative potentials in the examined range (−0.15V to −0.35V(SCE)), more PEG are adsorbed on the surface and form less-compact clusters in piles. In situ AFM images show that, in the damascene plating electrolyte containing PEG, Cl− and large amount of H2SO4, the adsorbed PEG appear to be flat-cone shaped clusters with a bottom diameter of several tens of nanometers, and a height of several nanometers. The diameters of the adsorbed clusters increase with time and the cathodic polarization, while the heights of the adsorbed clusters do not increase obviously. The present results suggest that PEG mainly contribute to the slow deposition rate at the external surface of nanometer-sized vias and trenches, for the dimensions of adsorbed PEG clusters are too big to move into the tiny structures.

Optimization of Osmo-convective Dehydration Process for the Development of Honey-ginger Candy Using Response Surface Methodology

Osmotic dehydration of ginger with honey is an interesting alternative for the development of confectionary-based functional food with extended shelf life. Response surface methodology (RSM) was used to investigate the effects of process variables on solid gain, water loss, and overall acceptability of honey-ginger candy. The process variables included blanching time (6–10 min), osmotic solution temperature (30–50°C), immersion time (90–150 min), and convective drying temperature (50–70°C). The honey to ginger ratio was 4:1 (w/w) during all the experiments. Ginger cubes were blanched before osmotic dehydration to increase the permeability of the outer cellular layer of tissue. After osmotic concentration of ginger with honey, convective dehydration was done to final moisture content of 3–5% (w.b.) to make it a shelf-stable product. Finally, osmo-convectively dried ginger was coated with sucrose for candy preparation. The optimum osmo-convective process conditions for maximum solid gain, water loss, and overall acceptability of honey-ginger candy were 7.07 min blanching time, 50°C solution temperature, 150 min immersion time, and 60°C convective drying temperature.

Cast joining of cast iron to aluminium casting matrix

The present study focused on reinforcing Al–Si–Cu alloy with a cast iron insert and using Zn–xAl–3Si–0·5Mg (wt-%) intermediate alloys by the cast joining technique to take advantage of lightness and stiffness of the hybrid structure. The experimental set-up consisted of coating the insert using hot dipping method followed by immersing the coated insert into the Al melt and allowing the system to cool down to the room temperature. The quality of Al–Fe joints in terms of morphology, thickness, chemistry and microhardness was evaluated as a function of coating composition and immersion time in the Al melt. Characteristics of reaction layer at the coating/insert interface and its effects on the joint properties were determined using microstructural analysis and thermodynamic calculations. Combination of a suitable coating containing 27 wt-%Al and optimised process parameters, including 1 min immersion time, resulted in the formation of an Al–Fe joint with promising characteristics.