Influence Of Treatment Time Research Articles

Influence of Treatment Time on the Synthesis of Copper Oxide Semiconductor Films by Cathode Cage Plasma Deposition

Influence of Treatment Time on the Synthesis of Copper Oxide Semiconductor Films by Cathode Cage Plasma Deposition

Plasma Immersion Ion Implantation of a Fe-Mn-C Based Steel for Biomedical Applications: Effect of Gases and Treatment Times on the Surface Properties

Current research on biodegradable iron-based alloys mainly focuses at regulating the material degradation rate, as well as its biological behavior, especially from the point of view of the hemocompatibility and cytocompatibility. In fact, fine-tuning of the surface roughness, morphology and chemical composition can improve the functional response of the material. For that purpose, a surface modification strategy, namely plasma immersion ion implantation (PIII), is proposed to perform the selective modification of surface properties without affecting the bulk ones. In this work, the influence of treatment time (timp = 15, 60 and 120 min.) and implanted species (O, N or C) on the surface properties of a Fe-13Mn-1.2C resorbable alloy was investigated. The findings demonstrated that varying the process gas and the exposition time led to a variety of topographies, surface energies and chemical compositions. XPS analyses and depth profiles clearly showed the impact of the process parameters on the surface features and element distribution, due to implanted species penetration into the alloy. The implanted samples showed a delayed clotting time, thus a better hemocompatibility. In contrast, nitrogen-treated surfaces displayed a more pronounced hemolytic behavior, whereas oxygen and methane did not. PIII implantation appears to be a versatile solution for fine-tuning surface topography, composition and biological properties, making the process promising for the improvement of metallic biodegradable vascular implants.

Hydroxyethylidene-1,1-diphosphonic acid surface treatment as insulation technology for iron based soft magnetic composites

In this study, we employed HEDP surface treatment as an insulation coating technology for the preparation of iron-based soft magnetic composites. The coating layer primarily comprises metal chelate, alongside minor quantities of iron oxides and hydroxides. The influence of treatment time on the microstructure, corrosion resistance and electromagnetic properties of the soft magnetic composites is investigated. The findings indicate a substantial enhancement in the corrosion resistance of iron powder treated with HEDP, and the iron powder subjected to a 90-minute treatment exhibited the most uniform and dense coating, yielding optimal magnetic properties. Notably, the sample's loss after a 90-minute treatment is recorded at 360.6 mW/g, indicating a remarkable reduction of 66.88 % when compared to the untreated sample. This research offers a straightforward and cost-effective approach for the industrial-scale production of soft magnetic composite materials with exceptional magnetic characteristics.

Effect of microwave treatment for wine microbial stabilisation: Potential use of a Weibullian mathematical model

The aim of this research was to investigate the efficiency of microwaves (MW) for wine microbiological stabilization and thereby assess the potential application of a Weibullian mathematical model in wine industry. The study focused on (i) the influence of treatment time (come-up time and temperature maintenance) and temperature on a simple wine-like matrix, as well as (ii) the specific resistance of yeast and bacteria selected according to their representativeness in red wines (A. aceti ATCC_15973, S. cerevisiae FX10, B. bruxellensis CRBO_L0619 and AWRI_1499), and finally (iii) the potential usefulness of a new mathematical model adapted to heat treatment to evaluate strain sensitivity. This research aimed to show that microwave treatment decreases the main wine-associated microorganism populations and that the reduction in viable counts mainly depends on the MW treatment temperature. Complete microbiological stabilisation was obtained under a temperature of 50 °C a very short treatment time, except in the case of A. aceti ATCC_15973. Furthermore, the Weibull parameters analyses showed that heat inactivation a wine microorganism studied did not follow first-order kinetics, indicating that we should change our way of studying thermal death curves. The findings from this study suggest that MW could be useful for the wine industry as a complement or an alternative to sulphite utilisation.

Microwave-assisted extraction of hemicellulosic oligosaccharides and phenolics from Robinia pseudoacacia wood

Microwave-assisted autohydrolysis is an environmentally friendly intensification technology that permits the selective solubilization of hemicelluloses in form of oligosaccharides in a short time and with low energy consumption. The purpose of this work was to evaluate the suitability of microwave-assisted autohydrolysis to produce oligosaccharides and phenolics with potential prebiotic and antioxidant activities from Robinia pseudoacacia wood. The influence of treatment time (0–30 min) and temperature (200–230 °C) on oligosaccharide production was studied and conditions of 230 °C and 0.25 min resulted in maximum content of xylooligosaccharides (7.69 g XO/L) and more efficient energy consumption. Furthermore, under those conditions, liquors showed high contents of phenols (80.28 mg GAE/g of RW) and flavonoids (44.51 RE/g) with significant antioxidant activities (112.07 and 102.30 mg TE/g, measured by ABTS and FRAP tests, respectively). Additionally, the solubilized hemicelluloses were structurally characterized by HPAEC-PAD, MALDI-TOF-MS, FTIR and TGA/DSC, and HPLC-ESI-MS analysis allowed the tentative identification of 17 phytochemicals.

Influence of Treatment Time and Temperature on the Surface Property of Active Screen Plasma-Nitrided EN41B Low Alloy Steel

Influence of Treatment Time and Temperature on the Surface Property of Active Screen Plasma-Nitrided EN41B Low Alloy Steel

Analysis of lignin content in alkaline treated hemp fibers: thermogravimetric studies and determination of kinetics of different decomposition steps

Hemp (Cannabis sativa L.) is a plant of which, its ease of cultivation, structure and properties, provide it great potential for industrial applications; nevertheless, the unfavorable content of lignin complicates its processing, especially in the textile area. Thus, an appropriate knowledge of the delignification process would lead to treating hemp fibers as cotton fibers. In this work, hemp has been treated with an alkaline liquor [NaOH 1 M] at 110 °C during different times and afterwards, the substrates were chemically characterized in order to determine their lignin content and also analyzed by thermogravimetry (TGA). Through the correlation analysis, the relationship between lignin content, onset temperature of cellulose decomposition and loss of mass at the different decomposition steps were established. A hyperbolic kinetic model to explain the influence of alkaline treatment time on lignin content and also on the loss of mass at the four steps of decomposition of the samples by TGA up to 600 °C has been developed. Although it has been found that the degradation of lignin occurred across the entire temperature range, results have shown that the influence of treatment time has become clearly relevant on lignin content, Step2 (180.5 °C-273.5 °C) where a fraction of 10 to 16% of lignin was degraded, and Step3 273.5 °C-396.5 °C) where cellulose was mainly decomposed and 20% of lignin was also degraded.

Evaluation of inter- and intra-fraction 6D motion for stereotactic body radiation therapy of spinal metastases: influence of treatment time

BackgroundThe objective of this study was to analyze the amplitude of translational and rotational movements occurring during stereotactic body radiotherapy (SBRT) of spinal metastases in two different positioning devices. The relevance of intra-fractional imaging and the influence of treatment time were evaluated.MethodsTwenty patients were treated in the supine position either (1) on a body vacuum cushion with arms raised and resting on a clegecel or (2) on an integrated SBRT solution consisting of a SBRT table top, an Orfit™ AIO system, and a vacuum cushion. Alignments between the cone beam computed tomography (CBCT) and the planning computed tomography allowed corrections of inter- and intra-fraction positional shifts using a 6D table. The absolute values of the translational and rotational setup errors obtained for 329 CBCT were recorded. The translational 3D vector, the maximum angle, and the characteristic times of the treatment fractions were calculated.ResultsAn improvement in the mean (SD) inter-fraction 3D vector (mm) from 7.8 (5.9) to 5.9 (3.8) was obtained by changing the fixation devices from (1) to (2) (p < 0.038). The maximum angles were less than 2° for a total of 87% for (1) and 96% for (2). The mean (SD) of the intra-fraction 3D vectors (mm) was lower for the new 1.1 (0.8) positioning fixation (2) compared to the old one (1) 1.7 (1.7) (p = 0.004). The angular corrections applied in the intra-fraction were on average very low (0.4°) and similar between the two systems. A strong correlation was found between the 3D displacement vector and the fraction time for (1) and (2) with regression coefficients of 0.408 (0.262–0.555, 95% CI) and 0.069 (0.010–0.128, 95% CI), respectively. An accuracy of 1 mm would require intra-fraction imaging every 5 min for both systems. If the expected accuracy was 2 mm, then only system (2) could avoid intra-fractional imaging.ConclusionsThis study allowed us to evaluate setup errors of two immobilization devices for spine SBRT. The association of inter- and intra-fraction imaging with 6D repositioning of a patient is inevitable. The correlation between treatment time and corrections to be applied encourages us to move toward imaging modalities which allow a reduction in fraction time.

Influence of Treatment Time and Temperature on Surface Property of Active Screen Plasma-Nitrided EN24 Low Alloy Steel

Influence of Treatment Time and Temperature on Surface Property of Active Screen Plasma-Nitrided EN24 Low Alloy Steel

Microwave Treatment to Reduce Refractoriness of Carbonic Concentrates

The article presents studies into the microwave treatment effect on higher recovery of noble metals from rebellious carbonic ore. The rate of refractoriness of carbonic concentrates was determined using a package of thermal testing techniques. Bitumen is an additional criterion of the refractoriness rate of mineral dressing products. The influence of treatment time on heating of a sample is studied at different microwave capacities. The process of heating of dry concentrates in electrolytic solution is analyzed. The applicability of microwave treatment of flotation concentrates toward higher recovery of gold from rebellious carbonic ore is proved.

Organic-solvent-free extraction of carotenoids from yeast Rhodotorula glutinis by application of ultrasound under pressure.

The extraction of Rhodotorula glutinis carotenoids by ultrasound under pressure (manosonication) in an aqueous medium has been demonstrated. The influence of treatment time, pressure, and ultrasound amplitude on R. glutinis inactivation and on the extraction of carotenoids was evaluated, and the obtained data were described mathematically. The extraction yields were lineal functions of those three parameters, whereas inactivation responded to a more complex equation. Under optimum treatment conditions, 82% of carotenoid content was recovered. Extraction of carotenoids in an aqueous medium was attributed to the capacity of ultrasound for cell disruption and emulsification. Cavitation caused the rupture of cell envelopes and the subsequent formation of small droplets of carotenoids surrounded by the phospholipids of the cytoplasmic membrane that would stabilize the emulsion. Analysis of the dispersed particle size of the extracts demonstrated that a fine, homogeneous emulsion was formed after treatment (average size: 230 nm; polydispersity <0.22). This research describes an innovative green process for extracting carotenoids from fresh biomass of R. glutinis in which only two unit operations are required: ultrasonic treatment, followed by a centrifugation step to discard cell debris. The extract obtained thanks to this procedure is rich in carotenoids (25 mg/L) and could be directly incorporated as a pigment in foods, beverages, and diet supplements; it can also be utilized as an ingredient in drugs or cosmetics.

The influence of treatment time on multi-walled carbon nanotubes functionalized by poly(ethylene glycol)

The paper reports an influence of treatment duration on the characteristics of multi-walled carbon nanotubes (MWCNTs) functionalised by poly(ethylene glycol) (PEG) for the first time. MWCNTs covalently functionalised with PEG (MWCNTs-PEG) are successfully prepared and characterised by several techniques including FE-SEM, EDX, Raman spectroscopy and TGA. The FE-SEM images show that an average tube diameter of the MWCNTs-PEG is increased by 21% in comparison to pristine MWCNTs. According to the TGA analysis and EDX measurements, the highest weight loss of 21.31 wt% and the highest ratio of oxygen to carbon (O/C) of 22.26 % are simultaneously achieved for the treatment time of 6 h. The results allow us to conclude that the optimum time to obtain the best functionalisation result is 6 h.

Influence of Treatment Time on Performance of Cr(III)-Based Conversion Coatings on Hot Dip Zn–55Al–1.6Si Coated Steel Sheet

In this work, the effect of treatment time on the performance of Cr(III) conversion coatings (TCC) on hot dip Zn–55Al–1.6Si (Zn55Al) coated steel sheet were investigated. The surface 3D morphology and roughness of TCCs were examined by a 3D topography instrument and the structure, chemical composition, and elemental depth distribution were studied by means of scanning electron microscope (SEM), X-ray photoelectron spectroscopy (XPS), and auger electron spectroscopy (AES). The results indicated that during the formation of TCC, the macro-roughness of Zn55Al surface was reduced, but the micro-roughness increased, which are considered to be key factors in enhancing the adhesion strength of epoxy primers. The AES depth profiles showed a two-layer TCC for both dendritic and inter-dendritic regions and chemical composition analysis of XPS showed that the surface of TCC was mainly oxides, fluoride and a small number of hydroxides. Overall, Zn55Al specimen prepared in a diluted commercial Cr(III)-based solution for 180 s at 40 °C performed a better adhesion strength to epoxy primer and had the largest polarization resistance among all TCCs in this work. Additionally, longer Cr(III) passivation process (TCP) treatment time will increase the sensitivity of the TCC to micro-cracks.

Silicon photovoltaic modules at end-of-life: Removal of polymeric layers and separation of materials

An eco-friendly process to recover valuable materials deriving from silicon based photovoltaic panels at end-of-life has been proposed. In particular, in this paper a new two-step process to separate and recover glass, Si and metals has been investigated and discussed. A preliminary mechanical treatment to remove fluorinated polymers allows to exclude dangerous emissions of hydrofluoric acid and fluorinated compounds coming out from conventional heat treatments. A subsequent thermal treatment allows the complete removal of the residual polymers and the separation of valuable materials. The influence of treatment time, temperature and atmosphere, during the polymers degradation has been evaluated and the by-products have been examined. The process efficiency has been assessed by determining the quantity and quality of the recovered materials. The results have shown that the combination of the two mechanical/thermal processes allows energy efficiency and environmental sustainability with respect to conventional recovery treatments. The optimal operating conditions for the thermal treatment have turned out 500 °C for 1 h in oxidizing atmosphere. The quality of the recovered materials has been determined by analysing the residual carbon content after the thermal treatment. The gaseous products of the polymeric degradation have been characterized by gas chromatography-mass spectrometry (GC–MS) analysis.

In-situ growth of nanostructured catalytic coatings via one-step plasma electrolytic oxidation

In the present work, we reported the in-situ preparation of nanostructured PEO catalysts on Al substrate in a corrosive aluminate solution. The influence of treatment time on the structure, composition, and performance of the coatings was studied in detail, and the film formation mechanism was proposed with consideration of the PEO theoretical basis. The morphology study showed that the obtained samples were highly porous and evenly covered with spherical nanoparticles with diameters of 15–25 nm. The coating treated for 60 min showed a high porosity of 30.5 ± 1.3%, in addition, an oxide film with a unique branch-like structure was formed when the duration was 120 min. The composition analysis suggested that the nanostructured coatings mainly consisted of Al2O3, and the doped Fe3O4 and CuO were enriched on the upper surface of the layer. Owing to the superior structure and high-content of active component, the specimen treated for 120 min exhibited the highest activity during the catalytic test.

Construction of Hydrophobic Wood Surface and Mechanical Property of Wood Cell Wall on Nanoscale Modified by Dimethyldichlorosilane

Dimethyldichlorosilane was used to improve the hydrophobicity of wood surface. The water contact angle of the treated wood surface increased from 85° to 143°, which indicated increased hydrophobicity. The nanomechanical properties of the wood cell wall were evaluated using a nanoindentation test to analyse the hydrophobic mechanism on the nano scale. The elastic modulus of the cell wall was significantly affected by the concentration but the influence of treatment time is insignificant. The hardness of the cell wall for treated samples was significantly affected by both treatment time and concentration. The interaction between treatment time and concentration was extremely significant for the elastic modulus of the wood cell wall.

Physico-chemical induced modification of seed germination and early development in artichoke (Cynara scolymus L.) using low energy plasma technology

In this study, low pressure non-thermal radiofrequency nitrogen plasma at very low power has been used to treat the artichoke seeds on the powered cathode for the first time. The influence of treatment time on the surface physical properties, germination rate, seedling growth, and enzyme activity of the seeds has been investigated. Results showed that plasma treatment considerably improved the germination rate and seedling growth. The root length grew by 28.5% and 50% and root dry weight increased by 13% and 53%, respectively, for 10 and 15 min of treatment. The same trend has been found for the shoot growth parameters although the greater stimulatory efficacy on root has been obtained. The nitrogen plasma treatment substantially made the seeds' surface hydrophilic which leads to 36.9% improvement in seed's water uptake at 15 min of treatment. Our study showed the activity of peroxidase and catalase enzymes slightly increased after the plasma treatment.

Impact of time on ultrasonic cavitation peening via detection of surface plastic deformation

During ultrasonic cavitation peening, bubbles repeatedly form and collapse, which leads to high impact loads on the treated surface. At the initial stage of ultrasonic cavitation peening, the most obvious change is plastic deformation instead of mass loss on the treated specimen surface. Meanwhile the plastic deformation is beneficial for mechanical surface properties. As the cavitation exposure time increases, erosion and damage are inflicted on the metal surface due to the increase in the number of collapse events. In this respect, the treatment time is a key parameter to improve the specimen surface properties during this manufacturing process. However, the influence of treatment time on the surface properties has not yet been thoroughly investigated. In this paper, it is the first time to utilize the plastic deformation to evaluate the optimal treatment time at different input power. The plastic deformation can be deduced by the mass loss and the volume change on the treated specimen surface. Using plastic deformation, the modification of surface hardness and roughness are investigated at different cavitation exposure intervals and vibration amplitudes. It is found that significant improvement of the microhardness on the treated surface occurs at the end of incubation period. Higher vibration amplitudes of the horn tip lead to shorter incubation period and higher microhardness.

Effect of low-energy nitrogen ion treatment of highly ordered pyrolytic graphite on oxygen reduction reaction activity

We systematically investigated highly ordered pyrolytic graphite film doped by low-energy atomic nitrogen ion of 20 eV, addressing major issues that include the effect of treatment time on the oxygen reduction reaction activity of highly ordered pyrolytic graphite film, and the influence of treatment time on the chemical and physical structures of highly ordered pyrolytic graphite surface. From the experimental results, it was clarified that the treatment for 60 s or less in nitrogen plasma was effective to modify the highly ordered pyrolytic graphite surface with improved oxygen reduction reaction performance, where the oxygen reduction reaction current increases by about 2 times as compared to that of untreated specimen. Moreover, we discussed the content of various C–N bonds, the strain which derived from the substitution of carbon and nitrogen, and a modification of the highly ordered pyrolytic graphite surface due to treatment, on the basis of the results of Raman spectroscopy, X-ray photoelectron spectroscopy, and atomic force microscopy.

Synthesis of guanidine-containing copolymers and their applications in the sorption of transition metals

2,2-Diallyl-1,1,3,3-tetraethylguanidinium chloride copolymers with N-substituted maleimides have been prepared by free radical copolymerization. Specific surface area and porosity of the copolymers under investigation have been determined by using the low-temperature adsorption method. Sorption capacity of the copolymers toward Re(VII), Mo(VI), Ni(II) and Cu(II) ions has been investigated. The influence of treatment time, temperature and pH on sorption of metal ions was studied. Copyright © 2016 John Wiley & Sons, Ltd.