Effects Of Different Processing Conditions Research Articles

Highly Efficient Reproducible Perovskite Solar Cells Prepared by Low-Temperature Processing.

In this work, we describe the role of the different layers in perovskite solar cells to achieve reproducible, ~16% efficient perovskite solar cells. We used a planar device architecture with PEDOT:PSS on the bottom, followed by the perovskite layer and an evaporated C60 layer before deposition of the top electrode. No high temperature annealing step is needed, which also allows processing on flexible plastic substrates. Only the optimization of all of these layers leads to highly efficient and reproducible results. In this work, we describe the effects of different processing conditions, especially the influence of the C60 top layer on the device performance.

Effect of different processing conditions on release of ingredients in solutions simulating gastric fluid and saliva

The fundamental understanding of the behavior of various foods in environments that simulate the human organism is of crucial importance. The study of the release of various components in solutions simulating the human gastric fluid and saliva helps in understanding their availability in the human body. In the present study, disintegration of salt and sugar particulates contained in processed agricultural products was examined. Potatoes and bananas were osmotically dehydrated in salt and sucrose solutions, respectively, and then dried using two drying methods, air drying and freeze drying. The dried products were soaked in simulated saliva and gastric fluid at 37°C. During immersion, salt release in saliva and gastric fluid was determined using three methods; electrochemical impedance spectroscopy, for measuring the resistance of the solution, titration with silver nitrate, for measuring the amount of salt in the solution and conductivity measurements, for measuring the conductivity of the solutions. Sugar release was determined by measuring degrees brix of the solutions at regular intervals. One Brix corresponds to 1g of sugars/100g of solution. The results indicated that different process conditions caused different impact on release kinetics of salt and sugar particulates in saliva and gastric fluid, influencing their taste perception and the bioavailability in the human body.

Dynamic particle analysis for the evaluation of particle degradation during compounding of wood plastic composites

A dynamic image analysis method was applied for particle characterisation to study the effect of different process conditions during twin-screw compounding of WPC. The use of distributions based on different types of quantity is discussed with respect to their sensitivity to reveal the effects of different process conditions on particle degradation. Distributions based on length proved to be most suitable to represent the initially broad length distribution of the particles before processing. Sensitivity was strong enough to show differences in particle size after processing depending on process conditions. Particle size was reduced by more than 97% compared to initial size. Degradation was stronger with increasing wood content and when the screw design contained more mixing elements. The effect of screw speed and feed rate was dependent on filler content and screw design.

A novel endo-β-N-acetylglucosaminidase releases specific N-glycans depending on different reaction conditions.

Milk glycoproteins are involved in different functions and contribute to different cellular processes, including adhesion and signaling, and shape the development of the infant microbiome. Methods have been developed to study the complexities of milk protein glycosylation and understand the role of N-glycans in protein functionality. Endo-β-N-acetylglucosaminidase (EndoBI-1) isolated from Bifidobacterium longum subsp. infantis ATCC 15697 is a recently isolated heat-stable enzyme that cleaves the N-N'-diacetyl chitobiose moiety found in the N-glycan core. The effects of different processing conditions (pH, temperature, reaction time, and enzyme/protein ratio) were evaluated for their ability to change EndoBI-1 activity on bovine colostrum whey glycoproteins using advanced mass spectrometry. This study shows that EndoBI-1 is able to cleave a high diversity of N-glycan structures. Nano-LC-Chip-Q-TOF MS data also revealed that different reaction conditions resulted in different N-glycan compositions released, thus modifying the relative abundance of N-glycan types. In general, more sialylated N-glycans were released at lower temperatures and pH values. These results demonstrated that EndoBI-1 is able to release a wide variety of N-glycans, whose compositions can be selectively manipulated using different processing conditions.

In-Situ Synthesis of FeF3/Graphene Composite for High-Rate Lithium Secondary Batteries

Nano-FeF3/graphene composite is successfully fabricated by an in-situ method. The structure and morphology of the samples are characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The effect of different processing conditions and different carbon sources is investigated. The electrochemical performance of FeF3/graphene is examined by discharge/charge and electrochemical impedance measurements. The results show that the less than 5% graphene-containing composite exhibits high capacity, stable cycling, and outstanding rate capability. The ultrafine particle size and the homogeneous network between FeF3 and graphene both contribute to the excellent electrochemical property.

CO methanation over TiO2-supported nickel catalysts: A carbon formation study

A systematic study on titania-supported nickel catalysts was performed in order to evaluate the effect of different process conditions on catalyst stability. Reaction tests and temperature-programmed-hydrogenation analyses were used in order to evaluate the effect of temperature, feed composition, water and reduction conditions on catalyst deactivation and carbon deposition. It was shown that high H2/CO ratios and syngas partial pressures decrease the rate of carbon formation. Moreover, increasing temperature enhanced the formation of more stable carbon species and thus catalyst deactivation. The temperature-programmed hydrogenation analyses also revealed that water reduces the rate of carbon deposition. However, water enhanced catalyst deactivation when the catalysts were reduced at high temperatures. This negative effect of water is probably due to a progressive destruction of the strong-metal-support interaction characteristic of titania-supported nickel catalysts reduced at high temperatures.

A novel ammonia-assisted method for the direct synthesis of Mn3O4 nanoparticles at room temperature and their catalytic activity during the rapid degradation of azo dyes

In this study, we prepared trimanganese tetroxide nanoparticles from MnCl2 solution in an ammonia atmosphere using a new surfactant-free method at room temperature. We analyzed and characterized the effects of different processing conditions, such as the concentrations of manganese and the ammonia source, as well as the reaction time, on the structure, purity, and morphology of the products using powder X-ray diffraction (XRD), scanning electron microscopy, and Fourier transformation infrared spectroscopy (FTIR) techniques. The XRD and FTIR analyses confirmed that the prepared products comprised single phase Mn3O4. At room temperature, the paramagnetic characteristics were also verified by vibrating sample magnetometry. Furthermore, we tested the catalytic activity of the nanoparticles during the degradation of methyl orange and Congo red, which are organic pollutants. Our experiments demonstrated the rapid color removal and reduction in the chemical oxygen demand (>70% and >50% within 10min, respectively) using aqueous solutions of azo dyes.

High-Performance Solution-Processed ZnSnO TFTs with Tunable Threshold Voltages

In this work, we had investigated the solution-processed zinc-tin oxide (ZTO) semiconductors using metal chloride precursors and the sol-gel method. We studied the effects of different processing conditions, such as different procedures of spin-coating and annealing, on thin-film transistor (TFT) characteristics (e.g., mobility, threshold voltages etc.). High-performance In-free solution-processed ZTO TFTs with mobilities up to 10–17 cm2/V⋅s and threshold voltages being tunable from positive to negative (i.e. from enhancement mode to depletion mode) had been achieved. The capability to control operation modes of TFTs provides the freedom to implement higher-performance TFT circuits (e.g. high-gain inverters demonstrated) using only solution-processed n-type ZTO TFTs. Using these two types of ZTO TFTs, depletion-load inverters were implemented, demonstrating enhanced characteristics in inverter characteristics compared to the enhancement-load inverters.

Gate Stack Engineering for High Temperature Silicon Carbide CMOS ICs

The potential to thermally grow SiO2 on silicon carbide has resulted in it becoming the technology of choice to realise high temperature CMOS circuits. The challenge to achieve a high quality gate stack relies on engineering the metal-insulator-semiconductor interfaces to enable reliable high temperature functionality. Here we describe the effect of different process conditions for the formation of the dielectric layer on the characteristics of the resulting devices. The operating characteristics at elevated temperatures depend critically on the quality of the gate stack. Therefore a systematic evaluation of the intrinsic properties of the gate stack and data from reliability tests are needed.

Silica-Aerogel Cotton Composites as Sound Absorber

AbstractIn the research reported in this paper, silica aerogel was synthesized in a cotton nonwoven mat (CNM) and then the composite was used as a sound absorber. The experimental data indicated that using aerogel as a coating on CNM significantly improved sound absorption up to 2,500 Hz. However for higher frequencies silica aerogel coating reduced sound absorption compared to neat CNM. The best sound absorption performance of the CNM coated aerogel happened between 250 and 2,500 Hz. The effects of different processing conditions were studied on the final properties of the silica aerogel and consequently on the sound absorption of the coated CNM. The pore size and surface area of the synthesized silica aerogel had no direct influence on the sound absorption properties of the composites; on the other hand, the density of the silica aerogel was the only critical factor that determined the sound absorption coefficients of the composites.

Extraction Behavior of Lipids Obtained from Spent Coffee Grounds Using Supercritical Carbon Dioxide

AbstractSupercritical carbon dioxide (sc‐CO2) extraction was applied to extract lipids from spent coffee grounds. The effects of different process conditions on the extraction yield and composition of the extracts were investigated by response surface methodology. A comparison of the experimental results with those obtained by conventional solvent extraction was also performed. In all these samples, the main fatty acids were rich in palmitic and linoleic acids. Moreover, a new method was developed and validated for the gas chromatographic analysis of sterols and tocopherols. The results demonstrate that sc‐CO2 extraction is principally a potential candidate method for the extraction of lipids and high value‐added compounds from residues/by‐products.

Effects of Different Processing Conditions on the Mechanical Properties of Dry Noodles

AbstractThis work adopted the method of compressive rod post‐buckling to determine the mechanical properties of dry noodles made under different processing conditions including flour mixing, dough resting and noodle pressing. The results showed that dry noodles had its highest elastic modulus at water addition of 33%, and the bending resistance ability of dry noodles increased as water addition increased. Within a certain range, all mechanical properties of dry noodles increased as mixing time and mixing speed increased. The effect of double resting was better than that of single resting of multidirectional compound pressing was superior to that of unidirectional compound pressing.Practical ApplicationsThe mechanical properties of dry noodles, including elastic modulus and bending resistance ability, which are greatly influenced by different processing conditions, are one of the main texture parameters to evaluate the quality of dry noodles and an aggregative indicator in order to characterize the component and the quality of dry noodles. So far, little research has been conducted to study the effects of processing conditions on the elastic modulus and the bending resistance ability of dry noodles. This work demonstrates a practical way for using instrumental method in order to determine the elastic modulus and bending resistance ability of dry noodles based on the compressive rod post‐buckling principle, which is suitable for quality inspection and control of dry noodle products. Moreover, this article provides a good example of process design and process parameter selection based on production requirements of noodle industry, thus having certain guiding values to the production of dry noodles.

Creation of well-defined particle stabilized oil-in-water nanoemulsions

The preparation of oil-in-water (o/w) nanoemulsions stabilized with silica nanoparticle sols has been investigated. The emulsification was performed using a high shear homogenizer (Microfluidizer TM processor, Microfluidics, USA). The effect of different processing conditions on the droplet size distribution and stability was investigated in emulsions prepared using different types of oils, oil concentration and particle/oil ratios. It was the ability of the particles to attach to, and stabilize the newly created interface, rather than their ability to lower the interfacial tension, what proved important for the drop size of the resulting emulsions. Changes in drop size distribution with time, attributed to Ostwald ripening effects, were observed for the more soluble oils, while stable nanoemulsions with droplet size of ∼100–200nm could be produced using a virtually water-insoluble oil such as squalene.

Structure and Mechanical Properties of Cu/AlN Nano-composites with High Strength and High Conductivity

Abstract This study is aimed to adopt the powder metallurgy method to prepare copper alloy series (Cu/AlN) nanocomposites with high strength and high conductivity. Optical microscopy, transmission electron microscopy, and scanning electron microscopy were used to examine the effect of different process conditions (temperature, pressure, repressing pressure, and resintering temperature) on the structure and mechanical properties of the composites. The results show that the density of the sample increases with the increase of pressure and sintering temperature. The Brinell hardness of the sample increases with the increase of repressing pressure, sintering temperature and AlN nanoparticle content. However, when AlN nanoparticle content is >0.5 wt%, the Brinell hardness of the composites decreases. The bending strength of the sample increases with the increase of repressing pressure and sintering temperature.

Microstructure, Fracture and Mechanical Properties of ECAPed Aluminum P/M Alloy with Respect to the Porosity

The main aim of this paper is to investigate the effects of different processing conditions on the behavior of a P/M (Powder Metallurgy) aluminum alloy with respect to the microstructure, fracture and mechanical properties. Moreover, the evolution of porosity as a consequence of pressing, sintering and ECAPing processes was investigated. A commercial Al-Mg-Si-Cu-Fe powder was used as material to be investigated. Different compacting pressures (400, 500, 600, 700 MPa) were applied. Specimens were dewaxed in a ventilated furnace at 400 °C for 60 min before sintering. Sintering was carried out in a vacuum furnace at 610 °C for 30 min. The specimens were ECAPed for 1 pass. The 2-dimensional quantitative image analysis was carried out by means of SEM and OM for the evaluation of the dimensional and morphological porosity characteristics. The detailed microstructure revealed the main features of sintering processes as well as secondary pores at the prior alloying particle sites. The tensile fracture surfaces in both studied processing condition (as-sintered and ECAP) show limited ductility, with fracture occurring on a plane normal to the tensile stress axis. Examination at higher magnifications revealed predominantly transparticle ductile features. In terms of mechanical properties, ECAP is almost doubling the tensile strength of the as-sintered materials

Study on the Effects of Diluent on Silica/Epoxy Resin Composite Material Phase Change

This study investigates the resulting nanocomposite material formed by hot-forming and molding epoxy resin containing diluent, nanosilica powder, and hardener. The effects of different processing conditions on the composite material, such as post-processing, nanopowder content, thinner amount, etc. The optimal processing conditions can be discovered by analyzing samples with a differential scanning calorimeter (DSC) to discern the glass transition temperature (Tg). Experimental results show that without post-processing, the composite material would not have enough reaction time, and that without thinner, the sample containing 1 wt% nanopowder had the highest Tg. The addition of thinner lowers the Tg of a sample, leading to reduced thermal properties.

A global model study of silane/hydrogen discharges

An algorithm to automatically build a general global chemical model on the basis of a set of chemical reactions is developed for capacitively coupled discharges. The methodology is applied to silane/hydrogen discharge regimes relevant for the deposition of microcrystalline silicon thin films for solar cell fabrication. The input parameters of the model are merely the process conditions such as absorbed power, pressure, gas flow, gas mixture and gap distance as well as the electron energy distribution function. Computational time is less than 30 s for an analytical description of the electron energy distribution and less than 40 s in the case of a look-up table for one set of process parameters for a silane/hydrogen gas mixture. The electron Boltzmann equation solver BOLSIG+ is used to determine the most appropriate electron energy distribution depending on different process conditions of this application. The numerical results of the global model are compared with measurements of silane depletion from the literature and show good agreement. A wide range of process conditions relevant for the deposition of thin-film silicon is covered. An analysis of the effect of different process conditions on the resulting plasma composition is performed. This shows the potential of a global model for silane/hydrogen discharges.

Synthesis, characterization and luminescence properties of thiol-capped CdSe quantum dots at different processing conditions

This work investigated the effect of different processing conditions and surface passivation on the growth and luminescence of CdSe quantum dots (QDs). The synthesis of CdSe QDs by pyrolysis of thiol reagents was performed by using the wet chemical route. In order to modify the size and quality of CdSe QDs, the growth temperature was controlled at 70°C while the relative amount of 2-mercaptoethanol, pH value and synthesis atmosphere were altered for getting an effective surface passivation of mono-disperse CdSe QDs with highly luminescence. The prepared nanocrystals are characterized by X-ray diffraction, transmission electron microscopy (TEM) and photoluminescence (PL) spectroscopy. The XRD pattern showed that the prepared CdSe has a cubic phase with zinc blend structure. The particle size was estimated from broadening of XRD peak using Scherrer’s formula and also from TEM images. The results showed that the synthesis of CdSe nanocrystals in N2 atmosphere has lower particle size compared with synthesis in open air. It is also found that the size of CdSe nanoparticle increases, as the CdSe/2-mercaptoethanol molar ratio is increased. The photoluminescence emission intensity for as-synthesized CdSe nanocrystals at different reaction conditions depicted that, the emission peak intensity strongly affected by the synthesis atmosphere, pH value and CdSe/2-mercaptoethanol molar ratio.

Effects of Different Processing Techniques on the Properties of PLA

PLA has excellent processing property and good thermal stability, which are closely related to the processing technology, and the general processing temperature can be controlled in 170~230°C. Effects of different processing conditions (internal mixing temperature, internal mixing time and internal mixing speed) on the properties of PLA were discussed. The results show that the mechanical properties and other performance of PLA can be obviously enhanced by internal mixing. Internal mixing time and internal mixing speed have little effects on the performance of PLA, but the internal mixing temperature has obvious effect on the properties of PLA. PLA has the optimum properties when the internal mixing time is 5min, internal mixing speed is 20r/min and internal mixing temperature is 190°C. The spherocrystal size and spherocrystal rate of PLA are influenced strongly by the mixing conditions.

Fabrication and Mechanical Characterization of a Microscale Electrophoretic Polymer Based on MEMS Technology

Microscale polyurethane modified epoxy resin film has been fabricated using MEMS tehnologies in the present paper. The effect of different process conditions on the thickness of fabricated film was discussed. The microscale film shows smooth and uniform surface morphology. The tensile test of the film by DMA indicates its tensile strength and Young's modulus are approximately 55MPa and 1.8GPa, respectively. The fracture section of the film was characterized by SEM. In addition, the interface bonding strength of the fabricated film between Ni substrate is much higher than Parylene-C and SU-8. This microscale polymer film is promising in several smart MEMS fields, especially bio-MEMS structures.