Rotary Friction Welded C45 to 16NiCr6 Steel Rods: Statistical Optimization Coupled to Mechanical and Microstructure Approaches

Abstract This work represents the production of dissimilar friction welded joints between C45 carbon steel and nickel-chromium alloy steel 16NiCr6. Central Composite Response Surface (RSM) methodology, optical microscopy, scanning electron microscopy (SEM), backscattered electron diffraction (EBSD) and bending test were performed for this study. Physicochemical characterization was used to reveal the welded joint microstructures. The bending test was done in order to measure the ultimate bending strength (UBS). As a conclusion, regarding the optimization of the parameters, friction time and the rotation speed were the most effective parameters on the joint strength. These parameters revealed that the maximum bending strength of 1406.892 MPa can be obtained at a rotational speed of 2000 rpm, a friction pressure of 24.77 MPa and a friction time of 13 seconds. On the weld samples it was also noted that the particle size decreases significantly as the units of the parameters increase, which led to note that the optimization of these parameters converges towards an average particle size, where were found a good accommodation between hardness and young’s modulus.

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Experimental Study of Zinc Powder Preparation by Electrochemical Method

Diyala Journal of Engineering Sciences ◽

10.24237/djes.2014.07201 ◽

2014 ◽

Vol 7 (2) ◽

pp. 1-15

Author(s):

Muwafaq Mahdi Abd Al Shammari

Keyword(s):

Particle Size ◽

Average Particle Size ◽

Correlation Coefficients ◽

Zinc Powder ◽

Electrochemical Process ◽

Electrochemical Technique ◽

Average Particle ◽

Optimal Conditions ◽

Effective Parameters ◽

Powder Preparation

This research has been done to study and diagnose operational factors and conditions affecting the zinc powder specification and efficient performance of the electrochemical process .The selection of the optimal conditions for the powder preparation at an average particle size up to 100 μm will be investigated with high productivity and efficiency.The results indicated that the adoption of electrochemical technique was suitable for obtaining zinc powder at average particle size less than of 100μm directly by 77.8% of the total amount prepared, purity of 99.2% and current efficiency (64.9%). The optimal conditions were through using an electrode cathode of stainless steel, zinc as an anode in alkaline medium of sodium hydroxide (200 g/l), zinc ions concentration up to (6 g/l), current density 0.19 amp/cm2 on the cathode electrode, and electrochemical deposition time of (2 hrs.). Also empirical relations obtained by correlating the effective parameters using non-linear regression with correlation coefficients (0.97 and 0.92) and the relation s are:Current efficiency (Y1) = - 884.65 - 2.5 X1 -1351.2 X1X2 + 55.62 X1X3 -0.04 X12 +12945.18 X2 -1715.78 X2X3 + .2.888 X22 - 0.96X3 -0.39X32, R= 0. 97Productivity (Y2) = 6225.1 + 174.3 X1 + 3442.8 X1X2 - 196.6 X1 X3 - 58189.7 X2 + 12689.7 X2 X3 - 1704.0 X2 2 - 1224.7 X3 -2.4 X3 2 , R= 0. 92

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Development of a Mosquito Repellent Formulation Based on Nanostructured Lipid Carriers

Frontiers in Pharmacology ◽

10.3389/fphar.2021.760682 ◽

2021 ◽

Vol 12 ◽

Author(s):

Daniele Carvalho Abrantes ◽

Carolina Barbara Rogerio ◽

Jhones L. de Oliveira ◽

Estefânia V. R. Campos ◽

Daniele Ribeiro de Araújo ◽

...

Keyword(s):

Particle Size ◽

Low Income ◽

Average Particle Size ◽

Physicochemical Characterization ◽

Nanostructured Lipid Carriers ◽

Average Particle ◽

Global Public Health ◽

Rheological Characterization ◽

Cellulose Hydrogel ◽

Thixotropic Behavior

Arboviral diseases are a threat to global public health systems, with recent data suggesting that around 40% of the world’s population is at risk of contracting arboviruses. The use of mosquito repellents is an appropriate strategy to avoid humans coming into contact with vectors transmitting these viruses. However, the cost associated with daily applications of repellents can make their use unfeasible for the low-income populations that most need protection. Therefore, the development of effective formulations offers a way to expand access to this means of individual protection. Consequently, research efforts have focused on formulations with smaller quantities of active agents and sustained release technology, aiming to reduce re-applications, toxicity, and cost. The present study investigates the development of nanostructured lipid carriers (NLCs) loaded with a mixture of the compounds icaridin (synthetic) and geraniol (natural), incorporated in cellulose hydrogel. The NLCs were prepared by the emulsion/solvent evaporation method and were submitted to physicochemical characterization as a function of time (at 0, 15, 30, and 60 days). The prepared system presented an average particle size of 252 ± 5 nm, with encapsulation efficiency of 99% for both of the active compounds. The stability profile revealed that the change of particle size was not significant (p > 0.05), indicating high stability of the system. Rheological characterization of the gels containing NLCs showed that all formulations presented pseudoplastic and thixotropic behavior, providing satisfactory spreadability and long shelf life. Morphological analysis using atomic force microscopy (AFM) revealed the presence of spherical nanoparticles (252 ± 5 nm) in the cellulose gel matrix. Permeation assays showed low fluxes of the active agents through a Strat-M® membrane, with low permeability coefficients, indicating that the repellents would be retained on the surface to which they are applied, rather than permeating the tissue. These findings open perspectives for the use of hybrid formulations consisting of gels containing nanoparticles that incorporate repellents effective against arthropod-borne virus. These systems could potentially provide improvements considering the issues of effectiveness, toxicity, and safety.

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Mechanical Properties and Fabrication of Silicon Carbide Ceramic by NITE Method

Solid State Phenomena ◽

10.4028/www.scientific.net/ssp.124-126.699 ◽

2007 ◽

Vol 124-126 ◽

pp. 699-702

Author(s):

Han Ki Yoon ◽

Young Ju Lee ◽

Yi Hyun Park ◽

Joon Soo Park ◽

Akira Kohyama

Keyword(s):

Mechanical Properties ◽

Bending Strength ◽

Average Particle Size ◽

Bending Test ◽

Average Particle ◽

Pressing Method ◽

Three Point Bending ◽

Nano Powder ◽

Strength Characterization ◽

Sintered Temperature

Nano infiltration transient eutectic ceramic (NITE-SiC) was fabricated by hot pressing method using Al2O3 and Y2O3 as sintering additives. The ratio of the Al2O3/Y2O3 additives was changed between 6:4 and 4:6. The densification and mechanical properties were investigated for the sintered temperature. The starting powder was high purity β -SiC nano-powder with an average particle size of 30nm. The bending strength characterization and densification of NITE-SiC was investigated by the FE-SEM and three point bending test.

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Determination of grinding parameters of fenugreek seed

Journal of Spices and Aromatic Crops ◽

10.25081/josac.2017.v26.i1.802 ◽

1970 ◽

Vol 26 (1) ◽

pp. 16 ◽

Cited By ~ 3

Author(s):

S Balasubramanian ◽

Rajkumar Rajkumar ◽

K K Singh

Keyword(s):

Particle Size ◽

Energy Consumption ◽

Moisture Content ◽

Specific Energy ◽

Feed Rate ◽

Average Particle Size ◽

Specific Energy Consumption ◽

Average Particle ◽

Fenugreek Seeds ◽

Fenugreek Seed

Experiment to identify ambient grinding conditions and energy consumed was conducted for fenugreek. Fenugreek seeds at three moisture content (5.1%, 11.5% and 17.3%, d.b.) were ground using a micro pulverizer hammer mill with different grinding screen openings (0.5, 1.0 and 1.5 mm) and feed rate (8, 16 and 24 kg h-1) at 3000 rpm. Physical properties of fenugreek seeds were also determined. Specific energy consumptions were found to decrease from 204.67 to 23.09 kJ kg-1 for increasing levels of feed rate and grinder screen openings. On the other hand specific energy consumption increased with increasing moisture content. The highest specific energy consumption was recorded for 17.3% moisture content and 8 kg h-1 feed rate with 0.5 mm screen opening. Average particle size decreased from 1.06 to 0.39 mm with increase of moisture content and grinder screen opening. It has been observed that the average particle size was minimum at 0.5 mm screen opening and 8 kg h-1 feed rate at lower moisture content. Bond’s work index and Kick’s constant were found to increase from 8.97 to 950.92 kWh kg-1 and 0.932 to 78.851 kWh kg-1 with the increase of moisture content, feed rate and grinder screen opening, respectively. Size reduction ratio and grinding effectiveness of fenugreek seed were found to decrease from 4.11 to 1.61 and 0.0118 to 0.0018 with the increase of moisture content, feed rate and grinder screen opening, respectively. The loose and compact bulk densities varied from 219.2 to 719.4 kg m-3 and 137.3 to 736.2 kg m-3, respectively.

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Formulating SLN and NLC as Innovative Drug Delivery Systems for Non-Invasive Routes of Drug Administration

Current Medicinal Chemistry ◽

10.2174/0929867326666190624155938 ◽

2020 ◽

Vol 27 (22) ◽

pp. 3623-3656 ◽

Cited By ~ 1

Author(s):

Bruno Fonseca-Santos ◽

Patrícia Bento Silva ◽

Roberta Balansin Rigon ◽

Mariana Rillo Sato ◽

Marlus Chorilli

Keyword(s):

Drug Delivery ◽

Particle Size ◽

Drug Release ◽

Drug Loading ◽

Average Particle Size ◽

Delivery Systems ◽

Average Particle ◽

Minor Importance ◽

Routes Of Administration ◽

Non Invasive

Colloidal carriers diverge depending on their composition, ability to incorporate drugs and applicability, but the common feature is the small average particle size. Among the carriers with the potential nanostructured drug delivery application there are SLN and NLC. These nanostructured systems consist of complex lipids and highly purified mixtures of glycerides having varying particle size. Also, these systems have shown physical stability, protection capacity of unstable drugs, release control ability, excellent tolerability, possibility of vectorization, and no reported production problems related to large-scale. Several production procedures can be applied to achieve high association efficiency between the bioactive and the carrier, depending on the physicochemical properties of both, as well as on the production procedure applied. The whole set of unique advantages such as enhanced drug loading capacity, prevention of drug expulsion, leads to more flexibility for modulation of drug release and makes Lipid-based nanocarriers (LNCs) versatile delivery system for various routes of administration. The route of administration has a significant impact on the therapeutic outcome of a drug. Thus, the non-invasive routes, which were of minor importance as parts of drug delivery in the past, have assumed added importance drugs, proteins, peptides and biopharmaceuticals drug delivery and these include nasal, buccal, vaginal and transdermal routes. The objective of this paper is to present the state of the art concerning the application of the lipid nanocarriers designated for non-invasive routes of administration. In this manner, this review presents an innovative technological platform to develop nanostructured delivery systems with great versatility of application in non-invasive routes of administration and targeting drug release.

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Azithromycin nanosuspension preparation using evaporative precipitation into aqueous solution (EPAS) method and its comparative dissolution study

Current Pharmaceutical Analysis ◽

10.2174/1573412917999200909145745 ◽

2020 ◽

Vol 17 ◽

Author(s):

Mohammad Hossain Shariare ◽

Tonmoy Kumar Mondal ◽

Hani Alothaid ◽

Md. Didaruzzaman Sohel ◽

MD Wadud ◽

...

Keyword(s):

Aqueous Solution ◽

Particle Size ◽

Dissolution Rate ◽

Average Particle Size ◽

Scale Up ◽

Average Particle ◽

Total Drug ◽

Residual Solvent ◽

Dissolution Study ◽

Drug Content

Aim: EPAS (evaporative precipitation into aqueous solution) was used in the current studies to prepare azithromycin nanosuspensions and investigate the physicochemical characteristics for the nanosuspension batches with the aim of enhancing the dissolution rate of the nanopreparation to improve bioavailability. Methods: EPAS method used in this study for preparing azithromycin nanosuspension was achieved through developing an in-house instrumentation method. Particle size distribution was measured using Zetasizer Nano S without sample dilution. Dissolved azithromycin nanosuspensions were also compared with raw azithromycin powder and commercially available products. Total drug content of nanosuspension batches were measured using an Ultra-Performance Liquid Chromatography (UPLC) system with Photodiode Array (PDA) detector while residual solvent was measured using gas chromatography (GC). Results: The average particle size of azithromycin nanosuspension was 447.2 nm and total drug content was measured to be 97.81% upon recovery. Dissolution study data showed significant increase in dissolution rate for nanosuspension batch when compared to raw azithromycin and commercial version (microsuspension). The residual solvent found for azithromycin nanosuspension is 0.000098023 mg/ mL or 98.023 ppb. Conclusion: EPAS was successfully used to prepare azithromycin nanoparticles that exhibited significantly enhanced dissolution rate. Further studies are required to scale up the process and determine long term stability of the nanoparticles.

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Evaluation of the Effects of Filler Fineness on the Properties of an Epoxy Asphalt Mixture

Materials ◽

10.3390/ma14082003 ◽

2021 ◽

Vol 14 (8) ◽

pp. 2003

Author(s):

Wei Xu ◽

Jintao Wei ◽

Zhengxiong Chen ◽

Feng Wang ◽

Jian Zhao

Keyword(s):

Particle Size ◽

Average Particle Size ◽

Asphalt Mixture ◽

Average Particle ◽

Fine Dust ◽

Bonding Structure ◽

Epoxy Asphalt ◽

Mineral Powder ◽

Marshall Stability ◽

Mixture Sample

The type and fineness of a filler significantly affect the performance of an asphalt mixture. There is a lack of specific research on the effects of filler fineness and dust from aggregates on the properties of epoxy asphalt (EA) mixtures. The effects of aggregate dust and mineral powder on the properties of an EA mixture were evaluated. These filler were tested to determine their fineness, specific surface area and mineral composition. The effects of these fillers on the EA mastic sample and mixture were evaluated. The morphology of the EA mastic samples was analyzed using scanning electron microscopy (SEM). The effects of the fillers on the Marshall stability, tensile strength and fatigue performance of the EA mixture were evaluated. The dust from the aggregates exhibited an even particle size distribution, and its average particle size was approximately 20% of that of the mineral powder. The SEM microanalysis showed that the EA mastic sample containing relatively fine dust formed a tight and dense interfacial bonding structure with the aggregate. The EA mixture sample containing filler composed of dust from aggregate had a significantly higher strength and longer fatigue life than that of the EA sample containing filler composed of mineral powder.

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Surface Activity of Humic Acid and Its Sub-Fractions from Forest Soil

Sustainability ◽

10.3390/su13158122 ◽

2021 ◽

Vol 13 (15) ◽

pp. 8122

Author(s):

Shijie Tian ◽

Weiqiang Tan ◽

Xinyuan Wang ◽

Tingting Li ◽

Fanhao Song ◽

...

Keyword(s):

Surface Tension ◽

Particle Size ◽

Humic Acid ◽

Forest Soil ◽

Surface Activity ◽

Self Assembly ◽

Average Particle Size ◽

Gaussian Model ◽

Exponential Model ◽

Average Particle

Surface activity of humic acid (HA) and its six sub-fractions isolated from forest soil were characterized by surface tension measurements, dynamic light scattering, and laser doppler electrophoresis. The surface tension of HA and its sub-fractions reduced from 72.4 mN·m−1 to 36.8 mN·m−1 in exponential model with the increasing concentration from 0 to 2000 mg·L−1. The critical micelle concentration (CMC) and Z-average particle size ranged from 216–1024 mg·L−1 and 108.2–186.9 nm for HA and its sub-fractions, respectively. The CMC have related with alkyl C, O-alkyl C, aromatic C, and carbonyl C (p < 0.05), respectively, and could be predicted with the multiple linear regression equation of CMC, CMC = 18896 − 6.9 × C-296 × alkyl C-331 × aromatic C-17019 × H/C + 4054 × HB/HI (p < 0.05). The maximum particle size was 5000 nm after filtered by a membrane with pore size of 450 nm, indicating HA and its sub-fractions could progressed self-assembly at pH 6.86. The aggregate sizes of number-base particle size distributions were mainly in six clusters including 2 ± 1 nm, 5 ± 2 nm, 10 ± 3 nm, 21 ± 8 nm, 40 ± 10 nm, and >50 nm analyzed by Gaussian model that maybe due to the inconsistency of the components and structures of the HA sub-fractions, requiring further study. It is significance to explore the surface activity of HA and its sub-fractions, which is helpful to clarify the environmental behavior of HA.

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Microstructure Characterization of Ag Nanoparticles Prepared by Hydrothermal Method

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.476-478.1138 ◽

2012 ◽

Vol 476-478 ◽

pp. 1138-1141

Author(s):

Zhi Qiang Wei ◽

Qiang Wei ◽

Li Gang Liu ◽

Hua Yang ◽

Xiao Juan Wu

Keyword(s):

Crystal Structure ◽

Particle Size ◽

Hydrothermal Method ◽

Ag Nanoparticles ◽

Average Particle Size ◽

Average Particle ◽

Face Centered Cubic ◽

Selected Area Electron Diffraction ◽

Transmission Electron ◽

Face Centered

Ag nanoparticles were successfully synthesized by hydrothermal method under the polyol system combined with traces of sodium chloride, Silver nitrate(AgNO3) and polyvinylpyrrolidone (PVP) acted as the silver source and dispersant respectively. The samples by this process were characterized via X-ray powder diffraction (XRD), Brunauer–Emmett–Teller (BET) adsorption equation, transmission electron microscopy (TEM) and the corresponding selected area electron diffraction (SAED) to determine the chemical composition, particle size, crystal structure and morphology. The experiment results indicate that the crystal structure of the samples is face centered cubic (FCC) structure as same as the bulk materials, The specific surface area is 24 m2/g, the particle size distribution ranging from10 to 50 nm, with an average particle size about 26 nm obtained by TEM and confirmed by XRD and BET results.

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Wheat Grinding Process with Low Moisture Content: A New Approach for Wholemeal Flour Production

Processes ◽

10.3390/pr9010032 ◽

2020 ◽

Vol 9 (1) ◽

pp. 32

Author(s):

Waleed H. Hassoon ◽

Dariusz Dziki ◽

Antoni Miś ◽

Beata Biernacka

Keyword(s):

Particle Size ◽

Moisture Content ◽

Average Particle Size ◽

Average Particle ◽

Grinding Process ◽

Mixing Properties ◽

New Approach ◽

Grain Moisture ◽

Flour Production ◽

And Storage

The objective of this study was to determine the grinding characteristics of wheat with a low moisture content. Two kinds of wheat—soft spelt wheat and hard Khorasan wheat—were dried at 45 °C to reduce the moisture content from 12% to 5% (wet basis). Air drying at 45 °C and storage in a climatic chamber (45 °C, 10% relative humidity) were the methods used for grain dehydration. The grinding process was carried out using a knife mill. After grinding, the particle size distribution, average particle size and grinding energy indices were determined. In addition, the dough mixing properties of wholemeal flour dough were studied using a farinograph. It was observed that decreasing the moisture content in wheat grains from 12% to 5% made the grinding process more effective. As a result, the average particle size of the ground material was decreased. This effect was found in both soft and hard wheat. Importantly, lowering the grain moisture led to about a twofold decrease in the required grinding energy. Moreover, the flour obtained from the dried grains showed higher water absorption and higher dough stability during mixing. However, the method of grain dehydration had little or no effect on the results of the grinding process or dough properties.

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