Nitrogen Gas Flow Rate Research Articles

Cold Plasma Effects on Functional Compounds of Siriguela Juice

The effects of glow discharge plasma on siriguela (purple mombin) juice quality were investigated through an experimental design changing the processing time (5–15 min) and the nitrogen gas flow rate (10–30 mL/min). Selected physicochemical properties and bioactive compounds were evaluated pre- and post-processing. No significant changes were found for vitamin C, and the processing did not affect the color of the product. Pigments, total phenolics, antioxidant activity, and B vitamins were increased due to the plasma processing. An increase in antioxidant activity was also observed. Polyphenol oxidase activity showed a decrease of about 20% (20 mL/min of N2/15 min), whereas peroxidase presented a slight activation (6%) in some processing conditions. The plasma processing imparted a positive or an adverse effect on the bioactive compounds in siriguela juice showing the importance of the optimization of food processing by cold plasma for real application. This behavior is related to the time intensity of the treatment, which can promote the extraction of the bioactive compound from the juice pulp followed by degradation at higher times or processing intensity. Due to the low pH of siriguela juice, no microbial contamination was found in the processed juices.

Intermediate pyrolysis of Acacia cincinnata and Acacia holosericea species for bio-oil and biochar production

Ever-increasing energy requirements coupled with the desire to cope with global warming have motivated researchers to look for alternative energy resources. Lignocellulosic biomass is an abundant renewable energy resource which can be exploited to reduce the dependency on fossil fuel resources. Acacia cincinnata and Acacia holosericea are fast-growing tree species which produce large quantities of biomass within short span of time and does not require major agricultural inputs to grow. This study is aimed at the intermediate pyrolysis process of Acacia cincinnata and Acacia holosericea species to produce biofuels such as bio-oil, biochar and gaseous product. Mass balance was done to calculate the yields of different products along with the characterisation of bio-oil and biochar produced. Experiments were carried out in a fixed-bed reactor at the pyrolysis temperature of 500 °C, heating rate of 25 °C/min and nitrogen gas flowrate of 100 cm3/min for the biomass feedstock having particle size between 0.5 and 1 mm. Comprehensive thermochemical characterisation of biomass samples was carried out prior to pyrolysis experiments. The chemical composition of bio-oil samples produced was determined using Gas Chromatography-Mass Spectroscopy (GC–MS) technique. Ultimate analysis, calorific values, pH values and the ash contents in the bio-oil samples were also determined. Bio-oil produced were reported to be complex mixtures of heterocyclic and phenolic compounds resulting from the thermal degradation of basic components of biomass with the calorific values obtained in the range of 23.46–30.65 MJ/kg. Biochar samples produced in the study were characterised with the help of ultimate analysis, FTIR analysis, calorific values, pH values and SEM and EDX analysis. Properties of biochars indicated suitability for energy as well as other applications such as soil remediation and adsorption purposes. Study revealed a decent potential of Acacia cincinnata and Acacia holosericea species as biofuels resources.

Chlorination of Titanium Carbonitride (TiC0.7N0.3) for Production of TiCl4

The chlorination of titanium carbonitride (TiC0.7N0.3) was conducted on the effect of temperature, reaction time and nitrogen gas flow rate for low-temperature production of titanium tetrachloride (TiCl4). Statistical design of experiments (DOE) was employed to analyze the interaction of the parameters. The chlorinated samples were characterized by X-Ray diffraction (XRD), scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDX) analysis. The DOE results showed that the flow rate of nitrogen (N2) gas was the most influential parameter followed by temperature and chlorination time. The highest weight loss for TiC0.7N0.3 sample was obtained to be about 79.52% at 500 °C for 60 minutes under N2 gas with the flow rate of 200 mL.min−1. The XRD patterns showed a strong decrease in intensity of TiC0.7N0.3 peaks. The XRD and SEM/EDX analyses also showed some free carbon in the residues after the chlorination process that could be formed from the chlorination of TiC in solid solution with TiN.

Thermocatalytic conversion of non-edible Neem seeds towards clean fuel and chemicals

In this work, a non-edible seed Neem (Azadirachta indica) was used to find out it’s potential to produce fuels and chemicals using thermo-catalytic pyrolysis. The physiochemical characterization confirmed the seed’s bioenergy potential. Thermal and catalytic pyrolysis were carried out at optimum conditions (500 °C temperature, 80 °C min−1 heating rate, 0.5 mm particle size and 80 mL min−1 nitrogen gas flow rate) which produced maximum liquid yield (49.53 wt. % at thermal, 54.06 wt. % and 52.08 wt. % for K2CO3 and Zeolite respectively at Biomass/Catalyst ratio 8:1). The comparative study of thermal and catalytic pyrolytic liquid confirmed that the yield as well as fuel properties of pyrolytic liquid were enhanced with the use of catalysts. It was also noticed that the energy content of gases increased with increasing pyrolysis temperature. Further, with increase in pyrolysis temperature, the amounts of hydrogen and hydrocarbons increased significantly, but at the same time, the formation of carbon dioxide was reduced.

The Influence of Ultrasonic Vibration Frequency on the Properties of TiN Coated Biomedical Ti–13Zr–13Nb

Bare biomedical grade titanium alloys are prone to degradation when in a body fluid environment. Surface coatings such as Physical Vapor Deposition (PVD) can serve as one of the options to minimize this issue. Past reports showed that the PVD coated layer consists of pores, pinholes, and columnar growths which act as channels through which the aggressive medium attacks the substrate. Duplex and multilayer coatings seem able to address this issue to varying extents but at the expense of manufacturing time and cost. In this paper, the effect of an ultrasonic vibration frequency on PVD TiN coated Ti–13Zr–13Nb biomedical alloy was studied. Disk type samples were prepared and coated with TiN at fixed conditions: bias voltage (−125 V), substrate temperature (300 °C), and nitrogen gas flow rate (300 standard cubic centimeters per minute (SCCM)). An ultrasonic vibration was then subsequently applied to the TiN coated samples at frequencies of 8 kHz and 16 kHz for 5 min. All TiN coated samples treated with ultrasonic vibrations exhibited a higher corrosion resistance than the untreated ones. Microstructure analysis under Field Emission Scanning Electron Microscopy (FESEM) confirmed that the coated sample at frequencies of 16 kHz produced the most compact coating. It is believed that the hammering effect of the ultrasonic vibration reduced the micro channels’ size in the coating and thus decelerated the corrosion’s attack.

Synthesis of Silicon Nitride Ceramic Fibers and the Effect of Nitrogen Atmosphere on their Morphology

The effect of nitrogen gas flow rate on the morphology of silicon nitride fibers obtained via carbothermal nitridation heat treatment method was investigated. A precursor containing silicon, oxygen and carbon was obtained by a sol-gel method from a mixture of tetraethyl orthosilicate, polyvinyl alcohol, H2O and ethanol. A white wool-like product was obtained by heat treating the precursor placed in an alumina crucible under a 0.5 MPa nitrogen gas pressure at 1500oC with different nitrogen gas flow rates. The mass-based production rates of the samples obtained from the precursor powder were 20-30% for the different nitrogen gas flow rates. X-ray diffraction analysis revealed that the samples contained α-Si3N4 as the major phase along with β-Si3N4, Si2N2O and a small amount of amorphous product as minor phases. Unique twisted fibers with diameters of several hundreds of nanometers were found among the straight fibers by SEM observation. Elemental analysis using energy dispersive X-ray spectroscopy indicated that silicon and nitrogen were contained in the twisted fibers along with approximately 68 at.% of oxygen and several at.% of aluminum, which might have come from the crucible material. The SiAlON-like structures might have been formed by the partial dissolution of Al and O in the Si3N4 fibers. It was considered that the twisted morphology of some fibers might be formed by co-existing of β-SiAlON and/or amorphous phase regions in the Si3N4 fiber and resultant distortion of the fibers.

Effect of CrN barrier on fuel-clad chemical interaction

Abstract Chromium and chromium nitride were selected as potential barriers to prevent fuel-clad chemical interaction (FCCI) between the cladding and the fuel material. In this study, ferritic/martensitic HT-9 steel and misch metal were used to simulate the reaction between the cladding and fuel fission product, respectively. Radio frequency magnetron sputtering was used to deposit Cr and CrN films onto the cladding, and the gas flow rates of argon and nitrogen were fixed at certain values for each sample to control the deposition rate and the crystal structure of the films. The samples were heated for 24 h at 933 K through the diffusion couple test, and considerable amount of interdiffusion (max. thickness: 550 μm) occurred at the interface between HT-9 and misch metal when the argon and nitrogen were used individually. The elemental contents of misch metal were detected at the HT-9 through energy dispersive X-ray spectroscopy due to the interdiffusion. However, the specimens that were sputtered by mixed gases (Ar and N 2 ) exhibited excellent resistance to FCCI. The thickness of these CrN films were only 4 μm, but these films effectively prevented the FCCI due to their high adhesion strength (frictional force ≥1,200 μm) and dense columnar microstructures.

Fabrication of Nitride Thin Films on Si Substrates by Atomic Layer Deposition Technique

AbstractRecently, Plasma Assisted Atomic Layer Deposition Technique will easily control the thickness and the composition of semiconductor films. The radical generated by using the plasma techniques, gave the decrease of the defect into the semiconductor films. In this investigation, the relationship between microwave plasma power, nitrogen gas flow rate and concentration of generated nitrogen radical, was evaluated. At the first, Plasma emission spectrum at microwave plasma power (0 to 400W) was measured using a mixed 200sccm argon gas and 10sccm nitrogen gas. Next, the plasma emission spectrum was measured in the mixing of nitrogen gas flow rate (0 to 40sccm) with 200sccm argon gas flow rate. At that time, the microwave plasma power was set to 200W. Nitrogen radical spectrum were identified from all the emission spectrum, and the nitrogen radical intensity was calculated. As a result, the nitrogen radical intensity became the largest at 200sccm argon gas flow rate and 10sccm nitrogen gas flow rate. In addition, the nitrogen radical intensity increased in proportion to the microwave plasma power. The concentration of generated nitrogen radical could be controlled by changing the microwave plasma power and the nitrogen gas flow rate. Mentioned above, nitride thin films will be obtained on Si Substrates by microwave generated remote plasma assisted atomic layer deposition technique.

Foaming of industrial lean methyldiethanolamine solution in the presence of hydrocarbon and fatty acid based corrosion inhibitors

In natural gas sweetening alkanolamine processes one of the regularly used chemical is the corrosion inhibitor. For better operation of the plant it is essential to understand the effect of their presence on foaming of industrial lean Methyldiethanolamine (MDEA) used as solvents at different temperatures. This study aimed at investigating the effect of HydroCarbon Based (HCB) and fatty acid based corrosion inhibitor having chemical name Bis(2-Hydroxyethyl)Cocoalkylamine (BHCL) on the foaming tendency of industrial real lean MDEA solutions. Experiments were conducted with different operating parameters, including liquid volume of the solution, foaming time, flow rate of nitrogen gas, concentration of the corrosion inhibitors, temperature of the solution, and gas diffuser pore size using the Foam Scan instrument. With the increase in solution volume and foaming time foaming happens to be more. The foaming tendency of lean MDEA solutions decreased with increasing temperature in absence of corrosion inhibitors but showed different behavior in their presence. At small diffuser pore size and high gas flow rate, the final foam volume increased in the presence of HCB but decreased with the BHCL inhibitor. Optimizing the operating parameters to minimize foaming was verified to be a function of the type of inhibitor used.

Production of Tomato Stalk Biochar and its Usage in Hydrophonic Agriculture

Tomato stalk is a waste remained after harvesting in agricultural productions. These wastes can be utilized as biochar for various purposes such as fuel, absorbent and soil improver. In this study, in order to waste utilization, biochar production from tomato stalk under different experimental conditions was carried out and effect of temperature, nitrogen gas flow and heating rate on yield of biochar was investigated. Characterization of biochar was performed with FTIR, TGA and SEM analysis. The highest biochar yield was obtained at the temperature of 773 K, heating rate of 5 K/min and inert gas flowrate of 500 ml/min. The highest yielded tomato stalk biochar was used as a supporting material for the tomato seedling planted in the hydroponic system of greenhouse. The tomato stalks obtained as a waste after harvesting in greenhouse were used for biochar production and biochars were applied as supporting material in greenhouse again, so, zero waste idea for a greenhouse was carried out. It has been observed that the supporting material provided a little more growth in the tomato seedling because of water and nutrient holding capacity.

Solar pyrolysis of scrap tire: optimization of operating parameters

Pyrolysis of scrap tire using concentrated solar radiation is a novel way to upgrade feedstock. In this investigation, best operating condition for maximizing pyro-oil yield was determined. The parameters varied were the temperature of the reactor, flow rate of nitrogen gas and size of the feed particles. The maximum pyro-oil yield was 52 wt% at 400 °C of reactor temperature and nitrogen flow rate of 6 lpm for a feed size of 4 cm3. The pyro-oil and char were characterized according to ASTM standards. This research showed the feasibility of converting scrap tire into pyro-oil by using solar energy via pyrolysis and analysis showed the potential of pyro-oil and char as a valuable source of chemicals.

Influence of Nitrogen Gas Flow Rate on The Microstructural and Mechanical Properties of Tin Deposited Carbon Steel Synthesized by Cae

This paper reports on the preparation of titanium nitride (TiN) thin films on carbon steel plates, using cathodic arc evaporation CAE PVD technique. We studied and discussed the effect of various nitrogen gas flow rates on microstructural and mechanical properties of TiN-coated carbon steel plates. The coating properties investigated in this work included the surface morphology, thickness of deposited coating, adhesion between the coating and substrate, coating composition, coating crystallography, hardness and surface characterization using a field emission scanning electron microscope (FE-SEM) with energy dispersive X-ray (EDX), Xray diffraction (XRD) with glazing incidence angle (GIA) technique, scratch tester, hardness testing machine, surface roughness tester and atomic force microscope (AFM). SEM analyses showed that all the films had columnar and dense structures with clearly defined substrate-film interfacial layers. The hardness of TiN-coated carbon steel was noted six times more than the hardness of uncoated one. An increase in nitrogen gas flow rate showed; decrease in the formation of macro-droplets, average roughness (Ra) and root-mean-square (RMS) values in CAE PVD technique. During XRD-GIA studies, it was observed that by increasing the nitrogen gas flow rate, the main peak [1,1,1] shifted toward the lower angular position. Microhardness of TiN-coated carbon steel showed about six times increase in hardness than the uncoated one. Scratch tester results showed an average adhesion between the coating material and substrate. Thanks to the high resolution power could be observed that by increasing nitrogen gas flow rate there was percentage increase in the bearing ratio while percentage decrease in histogram.

Microwave plasma application in decomposition and steam reforming of model tar compounds

Plasma methods can be considered as a novel and efficient way of tar disposal from process gases. In this lab-scale study, a microwave plasma reactor has been developed and tested for the conversion of tar surrogates, i.e. benzene, toluene, and 1-methylnaphthalene, in a nitrogen stream. The effect of tar concentration, gas flow rate and steam addition on conversion effectiveness has been analyzed. It was demonstrated that the process efficiency can be as high as c.a. 98% with the initial tar concentration of 10g/Nm3, the nitrogen gas flow rate being 30L/min and the steam-to-carbon ratio equal to 3. The conversion efficiency decreased with increasing tar concentration and gas flow rate. At the same time, the increase in the steam addition significantly enhanced the conversion rate. It has been revealed that the main products of the tar model compounds plasma conversion were: acetylene, soot, benzene derivatives (e.g. benzonitrile, phenylethyne, naphthalene and others) and cyanides. Their amounts were significantly decreased in favor of CO, CO2, and H2 by steam addition. Additionally, optical emission spectroscopy has been applied for the purpose of microwave plasma diagnostic and identification of the reactive species in the plasma zone. Moreover, a quantitative analysis of the main gaseous and aromatic byproducts has been conducted by means of gas chromatography.

Characterization of the optimal catalytic pyrolysis conditions for bio-oil production from brown salwood (Acacia mangium Willd) residues

Fast growing trees have recently attracted interest as a possible feedstock for bio-energy because they are environmentally friendly and provide a sustainable energy source. This work demonstrated the production of bio-oil and related chemicals by the catalytic pyrolysis of brown salwood (Acacia mangium Willd) residue in a continuous pyrolysis reactor using 1.00 wt % of dolomite catalyst. The effects of temperature (440–580 °C), biomass feed rate (0.3–0.9 kg h−1), and nitrogen gas flow rate (80–160 cm3 min−1) and their reciprocal interaction were determined; these parameters were adjusted systematically to optimize the experimental design using Box-Behnken design. Response surface methodology based on 3 levels of experimental design was used to determine the parameters that affected the production of bio-oil and the product distribution. The optimum conditions were determined to be a reaction temperature of 540 °C, a biomass feed rate of 0.45 kg h−1 and a nitrogen gas flow rate of 155.00 cm3 min−1 with a constant amount of 1.0 wt% dolomite catalyst. We obtained a maximum bio-oil yield of 44.78 ± 0.47 wt% through the use of response surface methodology. The modified quadratic regression model revealed the optimal application of temperature and feed rate in accordance with the residence time; meanwhile, the nitrogen gas flow rate was also considered. The bio-oil was characterized using GC-MS, FTIR, and physicochemical and elemental analyses. Brown salwood residues were shown to be applicable to thermal processes, and catalytic pyrolysis was shown to be a potential candidate to produce bio-oil and value-added chemicals for several applications.

Characterization of the external and internal flow structure of an aerated-liquid injector using X-ray radiography and fluorescence

In the present study, the internal flowfield of aerated-liquid fuel injectors is examined through X-ray radiography and X-ray fluorescence. An inside–out injector, consisting of a perforated aerating tube within an annular liquid stream, sprays into a quiescent environment at a fixed mass flow rate of water and nitrogen gas. The liquid is doped with bromine (in the form of NaBr) to create an X-ray fluorescence signal. This allows for reasonable absorption and fluorescence signals, and one or both diagnostics can be used to track the liquid distribution. The injector housing is fabricated from beryllium (Be), which allows the internal flowfield to be examined (as Be has relatively low X-ray attenuation coefficient). Two injector geometries are compared, illustrating the effects of aerating orifice size and location on the flow evolution. Time-averaged equivalent pathlength and line-of-sight averaged density ρ(y) reveal the formation of the two-phase mixture, showing that the liquid film thickness along the injector walls is a function of the aerating tube geometry, though only upstream of the nozzle. These differences in gas and liquid distribution (between injectors with different aerating tube designs) are suppressed as the mixture traverses the nozzle contraction. The averaged liquid velocity (computed from the density and liquid mass flow rate) reveals a similar trend. This suggests that at least for the current configurations, the plume width, liquid mass distribution, and averaged liquid velocity for the time-averaged external spray are insensitive to the aerating tube geometry.

Determination of pyrolysis properties of sirnak (Avgamasya) asphaltite by thermal analysis methods

ABSTRACTIn this study, pyrolysis properties of Sırnak asphaltite have been determined by thermal analysis methods. According to proximate and elemental analysis results, air-dried sample contains 0.56% moisture, 46.51% ash, 34.02% volatile matter, 18.91% fixed carbon, 42.1% C, 3.57% H, 0.50% N, 5.55% S, and 48.28% O by weight. For the determination of pyrolysis properties of the sample, DTA and TGA of thermal analysis methods have been used. DTA and TGA experiments have been carried out by using approximately 10 mg sample, under 50 ml/min nitrogen gas flow rate, from ambient to 900°C temperature range. To investigate the effects of particle size and heating rate on pyrolysis properties, TGA experiments have been carried out by using three different particle sizes and five different heating rates. By examining the TG/DTG thermograms, three different temperature regions have been found that depend on moisture loss, volatile release, and mineral matter decomposition. Also, by using TG/DTG data of the samples, apparent activation energies and Arrhenius constants were calculated by Arrhenius and Coats-Redfern kinetic models, and the results were compared with each other.

Potential use of olive stone biochar as a hydroponic growing medium

In this study, biochar production from olive stone was carried out under different conditions and effects of temperature, nitrogen gas flow and heating rate on yield of biochar were investigated. The highest biochar yield was obtained under the carbonization temperature of 773K, heating rate of 5K/min and nitrogen gas flow of 500ml/min. Characterization of biochar was performed with FTIR, TGA, SEM and BET analysis. In order to investigate the potential use of biochar in hydroponic system as solid media, it was evaluated for cultivating tomato seedling, and a comparison between using biochar and other materials such as perlite and coco peat for hydroponic growth was presented.Experimental study showed that the tallest tomato seedling was achieved with the media includes olive stone biochar. In conclusion, olive stone biochar can be used as effective solid media material for soilless agriculture methods like hydroponic system.

Simultaneous quantitative determination of 13 active components in the traditional Chinese medicinal preparation Suanzaoren oral liquid by HPLC coupled with diode array detection and evaporative light scattering detection.

To control the quality of different forms of Suanzaoren decoction, an effective and reliable method for the simultaneous determination of 13 major components (neomangiferin, mangiferin, spinosin, liquiritin apioside, liquiritin, 6'''-feruloylspinosin, senkyunolide I, timosaponin BII, isoliquiritoside, timosaponin C, jujuboside A, jujuboside B, and timosaponin AIII) was developed and validated for the first time in this study using high-performance liquid chromatography with diode array detection and evaporative light scattering detection. The chromatographic separation was performed on a Venusil MP C18 column (250mm×4.6mm, 5μm) at 30°C with a gradient of acetonitrile/redistilled water as the mobile phase. Diode array detection was carried out at a wavelength of 275nm. The drift tube temperature and the nitrogen gas flow rate of the evaporative light scattering detection were set at 50°C and 1.6L/min, respectively. The newly developed method was successfully applied to the determination of 13 components in lab-prepared Suanzaoren oral liquid, Suanzaoren mixture, and clinical Suanzaoren granules, and this study showed that this was a useful way to comprehensively evaluate the quality of Suanzaoren decoction in different forms of the preparation.

Flash Pyrolysis of Lemon Grass (Cymbopogon flexuosus) for Bio-oil Production in an Electrically Heated Fluidized Bed Reactor

Bio-oil, a hopeful substitute as an alternative fuel has gained significant attention due to the predicted shortness of conventional fuels and environmental concern. Bio-oils have attracted a lot of interest, as they are liquid energy carriers and general sources of chemicals. In this study, the pyrolysis characteristics of lemon grass were studied to evaluate their potential use as source of bio-oil. Flash pyrolysis of the lemon grass was carried out on a fluidized bed reactor with nitrogen gas atmosphere. The effects of operating parameters such as temperature, particle size and sweep (nitrogen) gas flow rate were investigated. During this study, the maximum yield of pyrolysis bio-oil 50.6 wt% can be achieved under the operation conditions of 450 °C process temperature, 1.0 mm particle size at sweep gas flow rate of 1.75 m3/h. At the end of the study the bio-oil obtained from the flash pyrolysis was analyzed for physical, elemental and chemical compositions by using Fourier transform infra-red (FTIR) spectroscopy, gas chromatography mass spectroscopy (GC-MS) and 1H NMR spectroscopy.

The Effect of Nitrogen Gas Flow Rate on the Cr-Containing DLC (Diamond-Like Carbon) Coating by AEGD Hybrid-CVD Coating Process

The development of electric and hybrid automobiles has gained momentum with the growth of interest in the field of miniaturization of electrode materials. In particular, technologies that improve the electrical property of stainless steel, while maintaining corrosion resistance, are gaining interest in terms of maintaining specific resistivity. The study on metal doping in diamond-like carbon coating is currently in progress to enhance the characteristics of conductivity and corrosion resistance with excellent properties such as corrosion resistance and lubrication coating. It is the process of using Cr arc with DLC coating to actuate AEGD. The change of I(D)/I(G) (Graphite peak (G) and disordered bond peak (D)) ratio and G-peak position in Cr-containing DLC film causes graphitization and thus lowers the basic electric resistance. Simultaneous input of nitrogen gas leads to deposition of CrN by a specific ratio of Cr and N in the DLC coating, and the nitrogen atoms replace hydrogen in bonding to increase the sp3 bond structure in the DLC film, in which CrN is not deposited, to result in specific resistivity of a specific value or less.