scholarly journals Preparation and Characterization of Sodium Alginate/Chitosan Composite Nanoparticles Loaded with Chondroitin Sulfate

2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
X. B. Yin ◽  
Q. Z. Yu ◽  
B. W. Li ◽  
C. D. Zhang
Keyword(s):  
Particle Size ◽  
Chondroitin Sulfate ◽  
Size Distribution ◽  
Sodium Alginate ◽  
Release Rate ◽  
Raw Materials ◽  
Weight Ratio ◽  
Composite Nanoparticles ◽  
Cumulative Release ◽  
Chitosan Composite

The chondroitin sulfate (CS)/sodium alginate (SA)/chitosan nanoparticles were prepared by electrostatic spraying technology. Laser particle size analyzer measurements indicated that the size of the particles is strongly affected by the weight ratio of raw materials, receiver rotation speed, injection rate, and so on. The size increased and size distribution moved towards the direction of large particle size with the decrease of applied voltage and increased with the increase of the flow rate and weight ratio of SA to CS; there is an optimal value for the effect of stirring rate on particle size and particle size distribution. The effect of different weight ratios of raw materials and pH on the sustained release rate of the product was investigated using a UV-visible spectrophotometer. Results showed the cumulative release rate of these particles was weight ratio of SA to CS and pH-dependent. The cumulative release rate of the CS/SA/chitosan composite nanoparticles with a weight ratio of SA to CS of 2 : 1 was higher at pH 6.8 than that at pH 1.2. By optimizing the process parameters, the CS/SA/chitosan composite particles were prepared, in which most of CS could pass through the stomach and release in the intestinal tract.

scholarly journals Phase evolution, characterisation, and performance of cement prepared in an oxy-fuel atmosphere

2016 ◽  
Vol 192 ◽  
pp. 113-124 ◽  
Author(s):  
Liya Zheng ◽  
Thomas P. Hills ◽  
Paul Fennell
Keyword(s):  
Particle Size ◽  
Compressive Strength ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Carbon Capture ◽  
Raw Materials ◽  
Carbon Capture And Storage ◽  
Phase Evolution ◽  
Chemical Compositions ◽  
Phase And Elemental Compositions

Cement manufacture is one of the major contributors (7–10%) to global anthropogenic CO2 emissions. Carbon capture and storage (CCS) has been identified as a vital technology for decarbonising the sector. Oxy-fuel combustion, involving burning fuel in a mixture of recycled CO2 and pure O2 instead of air, makes CO2 capture much easier. Since it combines a theoretically lower energy penalty with an increase in production, it is attractive as a CCS technology in cement plants. However, it is necessary to demonstrate that changes in the clinkering atmosphere do not reduce the quality of the clinker produced. Clinkers were successfully produced in an oxy-fuel atmosphere using only pure oxides as raw materials as well as a mixture of oxides and clay. Then, CEM I cements were prepared by the addition of 5 wt% gypsum to the clinkers. Quantitative XRD and XRF were used to obtain the phase and elemental compositions of the clinkers. The particle size distribution and compressive strength of the cements at 3, 7, 14, and 28 days' ages were tested, and the effect of the particle size distribution on the compressive strength was investigated. Additionally, the compressive strength of the cements produced in oxy-fuel atmospheres was compared with those of the cement produced in air and commercially available CEMEX CEM I. The results show that good-quality cement can be successfully produced in an oxy-fuel atmosphere and it has similar phase and chemical compositions to CEM I. Additionally, it has a comparable compressive strength to the cement produced in air and to commercially available CEMEX CEM I.

scholarly journals Investigation of Microbial Contamination and Physicochemical Properties of Compounded Medications in Pharmacies

2020 ◽  
Vol 26 (1) ◽  
pp. 82-93
Author(s):  
Reihaneh Radmanesh ◽  
◽  
Mohsen Nabi Meybodi ◽  
Vahid Ramezani ◽  
Maryam Akrami ◽  
...  
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Microbial Contamination ◽  
Raw Materials ◽  
Chemical Properties ◽  
Pharmaceutical Product ◽  
Physical And Chemical ◽  
Made In ◽  
And Chemical Properties

Aims: Any pharmaceutical product made in pharmacy, hospital or factory may be contaminated with microbes. This contamination can originate from raw materials or during production. Hence, it is important to study the physical and chemical properties and stability of compounded drugs. Methods & Materials: In this study, first a specific sample of prescribed medication was ordered from 63 pharmacies in Yazd, Iran. After collecting the samples, the amount of microbial contamination, viscosity and particle size distribution and their stability were investigated and their results were compared to the standard levels. Findings: Based on the results, 31.7% of the samples had discoloration and 23.8% showed creaming phenomenon. In terms of particle size distribution, 57.1% of the samples had a 20-40 μm particle size and 49.2% had a viscosity equal to 2500-3000 centipoise. Regarding stability, 12.6% of the samples underwnet phase change at 30-40°C. About of the amount of hydroquinone in samples, 35% had acceptable amount. In 23.8% of the samples, fungal infection was observed. Conclusion: Contrary to a popular belief that the compounded medicines produced in pharmacies have microbial contamination, the results of this study showed that the microbial contamination of these compounded medications is low.

scholarly journals Preparation and Evaluation of Sodium Alginate Microparticles using Pepsin

2020 ◽  
Vol 10 (2) ◽  
pp. 5-11
Author(s):  
Sankha Bhattacharya ◽  
Vishal Puri ◽  
Shubham Sharma ◽  
Debasish Sahoo ◽  
Pradeep Kumar Pal ◽  
...  
Keyword(s):  
Rheumatoid Arthritis ◽  
Particle Size ◽  
Zeta Potential ◽  
Size Distribution ◽  
Sodium Alginate ◽  
Calcium Chloride ◽  
Active Pharmaceutical Ingredient ◽  
Sulforhodamine B ◽  
Normal Particle ◽  
Preparation And Evaluation

Aim: The main aim of this article is to prepare and evaluate sodium alginate microparticles and evaluate on the basis of their characterization. The drug is dissolved, encapsulated or attached to a microparticles matrix. Depending upon method of preparation microparticles were obtained. Microparticles were developed as a carrier for vaccines and other disease like rheumatoid arthritis, cancer etc. Microparticles were developed to increase the efficacy of active pharmaceutical ingredient to a specific targeted site. Material and Method: Microparticles of Sodium Alginate, Pepsin and Calcium Chloride were prepared in six batches (A-F) with different ratio of sodium alginate and calcium chloride respectively i.e. (0.25:2.5), (0.25:5), (0.25:7.5), (0.5:2.5), (0.5:5), (0.5:7.5) by using a homogenizing method. Microparticles were evaluated for particle size distribution, zeta potential and morphology. Result and Discussion:  The normal particle size of each of the six batches were analyzed by Zeta Sizer (Delsa C Particle Analyzer) and it was found that the Batch B (0.25:5) delivered the best microparticles with size distribution of 1.2731 (µm). All batches were seen under Motic magnifying microscope by using the Sulforhodamine B (M.W. 479.02) color as staining dye. Microparticles was found to be semi spherical in shape. Conclusion: Results of all the six batches was contrasted based on particle size investigation, zeta potential and morphology. Batch B (0.25:5) was considered as the best formulation. Key words:  Micro Particle, Pepsin, Sodium Alginate and Calcium Chloride, Sulforhodamine B, Zeta Sizer.

scholarly journals Plasma Spheroidisation of Irregular Ti6Al4V Powder for Powder Bed Fusion

Metals ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 1763
Author(s):  
Nthateng Nkhasi ◽  
Willie du Preez ◽  
Hertzog Bissett
Keyword(s):  
Particle Size ◽  
Additive Manufacturing ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Metal Powder ◽  
Weight Ratio ◽  
High Strength ◽  
Powder Bed Fusion ◽  
Metal Powders ◽  
Powder Bed

Metal powders suitable for use in powder bed additive manufacturing processes should ideally be spherical, dense, chemically pure and of a specified particle size distribution. Ti6Al4V is commonly used in the aerospace, medical and automotive industries due to its high strength-to-weight ratio and excellent corrosion resistance properties. Interstitial impurities in titanium alloys have an impact upon mechanical properties, particularly oxygen, nitrogen, hydrogen and carbon. The plasma spheroidisation process can be used to spheroidise metal powder consisting of irregularly shaped particles. In this study, the plasma spheroidisation of metal powder was performed on Ti6Al4V powder consisting of irregularly shaped particles. The properties of the powder relevant for powder bed fusion that were determined included the particle size distribution, morphology, particle porosity and chemical composition. Conclusions were drawn regarding the viability of using this process to produce powder suitable for additive manufacturing.

Preparation and Properties of Cross-Linked Polysiloxane Microspheres for Light-Scattering

2017 ◽  
Vol 896 ◽  
pp. 57-61
Author(s):  
Ming Shan Yang ◽  
Peng Wei Yin ◽  
Hong Liang Tong
Keyword(s):  
Particle Size ◽  
Light Scattering ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Ph Value ◽  
Raw Materials ◽  
Narrow Particle Size Distribution ◽  
Vinyl Silane ◽  
Oil Water ◽  
Water Ratio

The narrow particle size distribution of poly (vinyl silicone) microspheres were prepared by the hydrolysis-polycondensation method with vinyl silane (VTMS) as raw materials. And the influences of pH value, oil/water ratio on the morphology, particle size and distribution of the microspheres were studied. The results shows that the particle size of microspheres decrease with the increasing of the PH value of polymerization, and the particle size has no specific linear relationship with the PH value of hydrolysis reaction, while the oil-water ratio is smaller, single particle size distribution is more narrow, more uniform distribution.

Combustion Synthesis of β-SiAlON Using 3D Ball Milling

2017 ◽  
Vol 898 ◽  
pp. 1717-1723 ◽  
Author(s):  
Xue Mei Yi ◽  
Shota Suzuki ◽  
Xiong Zhang Liu ◽  
Ran Guo ◽  
Tomohiro Akiyama
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Combustion Synthesis ◽  
Ball Mill ◽  
Raw Materials ◽  
Raw Material ◽  
Size Distributions ◽  
Particle Size Distributions ◽  
Material Particle

Combustion synthesis (CS) of β-SiAlON was conducted using a 3D ball mill, with a focus on the effect of the 2D/3D ball mill premixing conditions on the CS raw material particle size as well as on the yield and grain shape of the final products. The results showed that the particle size distribution of the raw materials was significantly affected by the premixing conditions. Various particle sizes and particle size distributions could easily be obtained by using a 3D mill instead of a 2D mill due to the complex biaxial rotation movement of 3D milling. The particle size was more sensitive to the rotation ratio (vertical spin/horizontal spin, Vv/Vh) than the rotation rate when using 3D milling. Finally, β-SiAlON with less than 5 mass% unreacted Si was obtained using premix milling conditions of 135×200 [vertical spin (rpm) × horizontal spin (rpm)]. The grain shapes of the final products were clearly influenced by the particle size distribution of the raw mixtures.

Research of the Particle Gradation Technology of Components in PBX Explosive Based on CPM Model

2015 ◽  
Vol 727-728 ◽  
pp. 366-369
Author(s):  
Qiu An Huang ◽  
Geng Guang Xu ◽  
Jian Yu Chen
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Relative Error ◽  
Fine Particles ◽  
Raw Materials ◽  
Maximum Value ◽  
Packing Model ◽  
Packing Efficiency ◽  
Compressible Packing Model

Basedon the assumption of related parameters in compressible packing model, thecompressible packing model was used for the calculation of the explosivespacking efficiency. The accuracy of the calculation was verified by experimentsand the relative error was 2.49%. Besides, the influence of content offineparticles and particle size distribution in explosives on stacking efficiencywas discussed. The results show that the stacking efficiency was increasingwith the particle size distribution increasing from 0~300μm to 0~700μm. Thepacking efficiency reached it’s maximum value when we only increased thecontent of fine particles to 40%. Therefore, the packing efficiency has arelation with particle size distribution of raw materials.

scholarly journals Characterization of Minim-Martap Bauxite and Its Extracted Alumina

2018 ◽  
Vol 4 (4) ◽  
pp. 598-600
Author(s):  
Parfait Aristide Zé ◽  
Cornelius Tsamo ◽  
Richard Kamga
Keyword(s):  
Particle Size ◽  
Relative Humidity ◽  
Ir Spectroscopy ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Acid Treatment ◽  
Raw Materials ◽  
Industrial Processes ◽  
Loss On Ignition

Due to their chemical and mineralogical properties bauxites are composites with multiple applications. In this work, the properties of bauxite collected from Minim-Martap and its extracted alumina were evaluated. Alumina was extracted by adapting the Bayer process at laboratory scale while the characteristics of bauxite and alumina were variably characterized by determining the particle size distribution, relative humidity, loss on ignition, pH, EC, CEC, PZC, XRD, IR, and DSC-TGA. These results show that Minim-Martap bauxite gray bauxite with easily extractable alumina. This bauxite is acidic with a pH of 6.05, PZC of 6.91 and CEC of 15 Meq/100 g which is closer to that of kaolinite clays. This result was confirm by XRD which shows two types of kaolinites: Al2Si2O5(OH)4 with 83.24% and H4Al2Si2O9 with 42.47%, mullite Al2.25Si0.75O4.875 with 67.32%, gibbsite (H2SiO4) with 83.92%. The bauxite is hydroscopic as evident from its humidity results. The IR spectroscopy of bauxite and alumina shows the presence of Al-OH and Si-OH which increase with acid treatment. Minim-martap bauxite and its extracted alumina can be used as raw materials for many industrial processes because of the different properties they possess as revealed by this study.

scholarly journals INFLUENCE OF GRANULOMETRIC COMPOSITION OF AGGREGATES ON THE PROPERTIES OF CONCRETE AND MORTAR MIXTURES

2020 ◽  
pp. 57-63
Author(s):  
М. С. Сайдумов ◽  
Т. С-А. Муртазаева ◽  
А. Х. Аласханов ◽  
В. А. Байтиев
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Raw Materials ◽  
Grain Composition ◽  
Maximum Particle Size ◽  
Fundamental Research ◽  
Scientific Project ◽  
Maximum Particle ◽  
Effect Of Particle Size

Технологические и эксплуатационные свойства бетонных и растворных смесей формируются за счет правильного учета в их рецептуре таких показателей, как форма и характер поверхности зёрен, зерновой состав, межзерновая пустотность, водопотребность и предельный размер частиц. Поэтому для проектирования доброкачественного состава необходимо изучить влияние гранулометрического состава мелкого и крупного заполнителей на основные свойства бетонных и растворных смесей. В работе поставлена цель оптимизировать гранулометрический состав заполнителей. Работа выполнена в рамках исследований по реализации научного проекта № 18-48-200001 «Высококачественные бетоны с повышенными эксплуатационными свойствами на основе местного природного и техногенного сырья», получившего поддержку Российского фонда фундаменталь- ных исследований» (РФФИ). The technological and operational properties of concrete and mortar mixtures are formed due to the correct consideration in their formulation of indicators such as the shape and nature of the surface of the grains, grain composition, intergranularvoidness, water demand and maximum particle size. Therefore, to design a benign composition, it is necessary to study the effect of particle size distribution of small and large aggregates on the basic properties of concrete and mortar mixtures. The goal is to optimize the particle size distribution of aggregates. The work was implemented as part of research on the fulfillment of scientific project No. 18-48-200001 “High-quality concrete with enhanced performance properties based on local natural and secondary raw materials,” which received support from the Russian Foundation for Fundamental Research (RFFR).

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