scholarly journals Experimental study of fractional composition of pieces of brittle material during crushing in a single-roll crusher with block stop on the roll

2020 ◽  
Vol 63 (7) ◽  
pp. 554-559
Author(s):  
A. G. Nikitin ◽  
Yu. A Epifantsev ◽  
K. S. Medvedeva ◽  
P. B. Gerike ◽  
A. R. Fastykovskii
Keyword(s):  
Isotropic Material ◽  
Spherical Shape ◽  
Metallurgical Industry ◽  
Tangential Stresses ◽  
Roll Type ◽  
Cement Mixture ◽  
Series Of Experiments ◽  
Materials Used ◽  
Regular Spherical Shape ◽  
Roll Crusher

Processing of bulk materials used in metallurgical industry to obtain necessary grades of size requires application of crushing machines, including a single-roll type. Indicators of crushing process are degree and efficiency of crushing. Degree of crushing is estimated by the ratio of size of initial crushed and resulting pieces, which depends on size of the gap between a roll and a fixed jaw. The Siberian State Industrial University has patented, designed and manufactured a pilot unit, which is a single-roll crusher with block stop on the roll to study crushing process. A series of experiments on different samples (in shape, size and strength) crushing was carried out on the developed unit. Technique of the experiment and the design of a single-roll crusher with block stop on the roll were described. Results of destruction of the samples of isotropic material made of sand-cement mixture of regular (spherical) shape are presented. Samples from isotropic material allow comparison of analytical conclusions of determining position of the plane of action of maximum tangential stresses with experimental data. Samples of anisotropic material (for example, ferroalloy) were also destroyed. It was experimentally determined that the larger is clearance between the roll and the fixed jaw, the larger is the size of fraction of finished product and over-grinding is less than after crushing the same piece with a smaller clearance. The degree of crushing in a single-roll crusher with block stop on the roll cannot be equal to 4 or more. It was proved that destruction of isotropic materials occurs along the plane of action of maximum tangential stresses. Anisotropic materials are destroyed, depending on size of clearance between a roll and a jaw, both on the plane of action of the maximum tangential stresses and on the planes of least resistance.

scholarly journals Preparation of microencapsulated PCMs for energy saving and thermal comfort of buildings

2021 ◽  
Vol 23 (09) ◽  
pp. 277-287
Author(s):  
Ashraf Mohamed Heniegal ◽  
◽  
Omar Mohamed Omar Ibrahim ◽  
Nour Bassim Frahat ◽  
Mohamed Amin ◽  
...  
Keyword(s):  
Thermal Performance ◽  
Chemical Interaction ◽  
Spherical Shape ◽  
Building Envelope ◽  
Scanning Calorimetry ◽  
Indoor Temperature ◽  
New Techniques ◽  
Consumption Energy ◽  
Local Materials ◽  
Regular Spherical Shape

Energy improvement techniques for buildings are among the modern studies that concentrate on new techniques and methods of saving energy and improving the thermal performance in buildings. This research aims to prepare microencapsulated-PCMs (micro-PCMs) by using local materials and studied the influence of using micro-PCMs on thermal performance improvement and PCMs leakage problems improvement. The micro-PCMs of paraffin wax were prepared as the core PCMs materials while the melamine-formaldehyde polymer as the shell. The micro-PCMs were characterized through scanning electron-microscopy (SEM), energy-dispersive X-ray (EDX) spectrometry, Fourier-transform infrared spectroscopy, and differential scanning calorimetry. Analysis results showed the prepared micro-PCMs present a regular spherical shape and confirm that the formation composite of the shell effectively encapsulated the cores. Furthermore, the absence of chemical interaction between the MF and the PW components. The micro-PCM have potential for architectural applications in the building-envelope to store thermal energy, provide indoor-temperature at the comfortable range, and reduce the consumption energy in buildings.

scholarly journals Evaluation of morphological parameters and bioactive compounds in different varieties of beetroot (Beta vulgaris L. ssp. esculenta GURKE var. rubra L.)

2015 ◽  
Vol 21 (3-4) ◽  
Author(s):  
T. Rubóczki ◽  
V. Raczkó ◽  
M. Takácsné Hájos
Keyword(s):  
Manufacturing Industry ◽  
Spherical Shape ◽  
Close Correlation ◽  
Quality Parameters ◽  
Water Soluble ◽  
Soluble Solids ◽  
Fresh Market ◽  
Mona Lisa ◽  
Solids Content ◽  
Regular Spherical Shape

Beetroot consumption based on pickled beets generally in Hungary which is due to the higher yield from second crop harvested in autumn and processed by manufacturing industry. Researches of the past years confirmed its favourable nutritional-physiological effects on human body so demands, as for fresh salad, also increased. The trial aimed at testing the interaction of varieties on quality parameters and in the same time suggestions are made how to use different varieties of beetroot according to its quality. Morphological and sensory evaluations were examined on 10 varieties of beetroot harvested in autumn. The regular spherical shape can reduce the refining loss during the processing of beetroot which is beneficial for the manufacturing industry. In our trial the root shape of Libero, Mona Lisa and Rubin varieties approached most the regular spherical shape (diameter/length – 1.0) which is favoured by not only processing industry but also fresh market. The highest red pigment content (betanin) was observed in Mona Lisa, Akela and Cylindra (34.58–47.66 mg/100 g). A similar trend could be observed in yellow pigments (vulgaxanthins) which proves the close correlation between the quantities of the two pigments (r=0.898). Highest total polyphenol (77.13–83.37 mg GAE/100g) and flavonoid (21.73–22.73 mg CE/100g) contents were detected in Akela, Mona Lisa and Bonel. These varieties are favourable for fresh salad and they can satisfy processing requirements also. Highest water soluble solids content was found in Akela (7.15%). In our conditions nitrate (NO3-N) values below 900 mg/kg were examined in all of the varieties which is favourable in the case of beetroot.

scholarly journals MORPHOLOGY AND ELEMENT COMPOSITION POWDER ALLOY POWDER VNZH-95, OBTAINED BY ELECTROEROSION DISPERSION IN KEROSIN

2020 ◽  
pp. 15-20
Author(s):  
E. V. Ageev ◽  
N. M. Khoriakova ◽  
K. V. Sadova
Keyword(s):  
Elemental Composition ◽  
Alloy Powder ◽  
Spherical Shape ◽  
Working Fluid ◽  
Residence Permit ◽  
Nickel Iron ◽  
The Russian Federation ◽  
Biological Protection ◽  
Regular Spherical Shape ◽  
Electroerosion Dispersion

Residence permits pseudo-alloys are used for the manufacture of cylinder parts, bushings, complex-shaped blanks with curved surfaces: gyroscope rotors, inertial masses, erosion-resistant electrodes, funnel for cumulative charges, biological protection from gamma radiation. Recycling of tungsten pseudo-alloys residence permit is relevant and necessary due to the shortage of tungsten. A promising method of processing waste into fine powders is the method of electroerosive dispersion (EED) that we have chosen. The purpose of the work is to study the morphology and elemental composition of the powder of the VNZh-95 pseudo-alloy obtained by electroerosive dispersion in kerosene. In order to process the waste of the W-Ni-Fe alloy into powder, we used waste in the form of chips from the core of the VNZh-95 pseudo-alloy (Ni ̶ 3.2-3.7, Fe ̶ 1.5-2.0, W ̶ the rest). Kerosene is used as a working fluid. The EED process was carried out on the installation for obtaining powders from conductive materials (patent for the invention of the Russian Federation No. 2449859). The process was carried out at a voltage on the electrodes of 100 ... 110 V, the capacitance of the discharge capacitors 50 μF and a pulse repetition rate of 120 ... 130 Hz. The microstructure of the samples (along the transverse section) was studied using a Quanta 200 3D electron-ion scanning microscope. The powder obtained by the EED method for waste of VNZh-95 alloy in kerosene consists of particles of regular spherical shape (or elliptical) and irregular shape (conglomerates). Microanalysis of particles of electroerosive powder of pseudo-alloy VNZh-95 was carried out using an EDAX energy-dispersive x-ray analyzer built into the Quanta 200 3D scanning electron microscope. As a result of studying the elemental composition of the VNZh-95 pseudo-alloy powder obtained by EED in kerosene, it was found that the main elements are tungsten, nickel, iron, carbon and oxygen.

Structure and Properties of Modifier for Heat Transfer Printing on Cotton Fabric

2011 ◽  
Vol 331 ◽  
pp. 426-429
Author(s):  
Yi Mu ◽  
Lan Wang ◽  
Ming Hua Wu ◽  
Jun Xiong Lin
Keyword(s):  
Heat Transfer ◽  
Spherical Shape ◽  
Decomposition Temperature ◽  
Polymerization Process ◽  
Structure And Properties ◽  
Transfer Printing ◽  
Transmission Electron ◽  
Ft Ir ◽  
Regular Spherical Shape

Modifier for heat transfer printing on cotton fabrics was prepared by semi-continuous emulsion polymerization process with butyl acrylate (BA), styrene (St), acrylonitrile (AN) and cross-linking monomer. FT-IR characterization of modifier groups showed that individual monomer well carried out polymerization. Transmission electron microscopy (TEM) photos demonstrated that latex particles had regular spherical shape and uniform distribution. TGA curves indicated that thermal decomposition temperature of modifier was 439 oC. As for the transfer printing products had good colour fastness, high transfer rate and no formaldehyde.

scholarly journals Synthesis, Characterization, and In Vitro Drug Delivery of Chitosan-Silica Hybrid Microspheres for Bone Tissue Engineering

2019 ◽  
Vol 2019 ◽  
pp. 1-7 ◽  
Author(s):  
Niu Niu ◽  
Shu-Hua Teng ◽  
Hua-Jian Zhou ◽  
Hai-Sheng Qian
Keyword(s):  
Drug Release ◽  
Sol Gel ◽  
Particle Diameter ◽  
Spherical Shape ◽  
Average Particle ◽  
High Dispersity ◽  
Model Drug ◽  
Regular Spherical Shape

Chitosan-silica (CS-SiO2) hybrid microspheres were prepared through the combined process of sol-gel and emulsification-crosslinking. Their composition, morphology, in vitro bioactivity, and drug release behavior were investigated. The results showed that, when 20 wt% SiO2 was incorporated, the as-prepared CS-SiO2 hybrid microspheres exhibited a regular spherical shape, a high dispersity, and a uniform microstructure. Their average particle diameter was determined to be about 24.0 μm. The in situ deposited inorganic phase of the hybrid microspheres was identified as amorphous SiO2, and its actual content was determined by the TG analysis. As compared with the pure chitosan microspheres, the CS-SiO2 hybrid microspheres displayed a greatly improved in vitro bioactivity. Vancomycin hydrochloride (VH) was selected as a model drug. It was demonstrated that the CS-SiO2 hybrid microspheres presented a good capacity for both loading and sustained release of VH. Moreover, the increase of the SiO2 content efficiently slowed down the drug release rate of the CS-SiO2 hybrid microspheres.

Use Wear on Bone and Antler Tools from the Mackenzie Delta, Northwest Territories

1994 ◽  
Vol 59 (2) ◽  
pp. 316-334 ◽  
Author(s):  
Genevieve M. LeMoine
Keyword(s):  
Northwest Territories ◽  
Experimental Results ◽  
Fish Scales ◽  
Mackenzie Delta ◽  
Use Wear ◽  
Similar Materials ◽  
Series Of Experiments ◽  
Materials Used ◽  
Historical Accounts ◽  
Lines Of Evidence

A series of experiments making and using bone and antler tools show that functional identifications of these tools can be made with confidence in some circumstances. Using principles from the field of tribology, the experiments demonstrate that different uses leave different microscopic traces on bone and antler. They also show that when the materials used are similar, the wear produced will be similar. In particular, wet materials, including snow, ice, wet hide, and wet antler all produce nearly identical microscopic patterns. Other groups of similar materials, such as bone, antler, and wood, or fish scales and hair, present the same problem. Although differences can be detected, these may not be preserved on archaeological tool specimens. Application of the experimental results to bone and antler tools from the Mackenzie Delta illustrates that functional identifications of tools can be made with confidence, despite the problem of similar microscopic patterns, when other lines of evidence (ethnographic and historical accounts, distribution of wear) are taken into account. When such information is lacking, functional identifications are more difficult and must be made with more caution.

scholarly journals Effect of Temperature Changes on the Vibration Transmissibility of XPE and PE Packaging Cushioning Material

2021 ◽  
Vol 11 (2) ◽  
pp. 482
Author(s):  
Péter Csavajda ◽  
Péter Böröcz
Keyword(s):  
Effect Of Temperature ◽  
Protective Mechanism ◽  
Package Design ◽  
Temperature Changes ◽  
Vibration Stress ◽  
Vibration Transmissibility ◽  
Characterization Of Properties ◽  
Series Of Experiments ◽  
Materials Used ◽  
Protective Packaging

Polyethylene (PE) and its variations are among the most traditional materials used for cushioning in packaging systems. The role of these materials is to prevent damages during handling and distribution processes from physical events such as vibration stress. This study presents new results on the characterization of properties of PE and XPE (cross-linked polyethylene) packaging materials, which have significant relevance as a protective mechanism due to their vibration transmissibility and frequency curve properties. The main goal of this study is the evaluation of vibration transmissibility of PE and XPE cushion material at varied real temperature and static load conditions through a series of experiments using a vibration tester and climate chamber to determine the peak frequencies, vibration transmissibility, and damping ratios. The results can be used by engineers in the package-design process, and can be useful in different distribution conditions. Three different kinds of static loads and a 0.5 oct/min sine sweep of vibration test were used to find the peak frequencies and vibration transmissibility at −20 °C, 0 °C, 20 °C and 40 °C to estimate the damping ratios. The results provided a better understanding of the materials and can assist in the design of suitable protective packaging systems.

scholarly journals The Manufacture of Synthetic Rutile by Solvent Extraction of Tri-Alkyl Phosphine Oxide from HCl Leaching Solution of Soda-Roasted Ilmenite Ore

Metals ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 588
Author(s):  
Sung-Ho Joo ◽  
Dong Ju Shin ◽  
Dongseok Lee ◽  
Jungshin Kang ◽  
Min-seuk Kim ◽  
...  
Keyword(s):  
Solvent Extraction ◽  
Organic Phase ◽  
Phosphine Oxide ◽  
Inductively Coupled Plasma ◽  
Spherical Shape ◽  
Feed Solution ◽  
Synthetic Rutile ◽  
Inductively Coupled ◽  
Leaching Solution ◽  
Series Of Experiments

To manufacture TiO2, a high-purity synthetic rutile, the recovery of Ti was investigated using a hydro-metallurgical process. Using a feed solution containing 32050 mg/L Ti, 110 mg/L Si, 88 mg/L Nb, 2614 mg/L Fe, and 130 mg/L Zr, solvent-extraction experiments were conducted with alkyl phosphine oxide in conjunction with diluents such as kerosene and xylene. The results showed that the extraction mechanism of both diluents was very similar to slope analysis, which had a value of 1.9; however, the extraction equilibrium constant value of organic–metallic species in xylene as a diluent was lower than in kerosene as a diluent. This result affected the stripping efficiency of Ti in particular; therefore, xylene was selected as a diluent. To recover Ti ion from a leaching solution, a series of experiments was conducted, such as the McCabe–Thiele method and countercurrent simulation test for extraction and stripping of Ti. As a result, Ti and impurities such as Fe and Zr were extracted to 99.9% from Si and Nb under optimal conditions using countercurrent four-stage extraction, with 1 M Cyanex 923 at a ratio of organic phase/ aqueous phase=3. In the stripping test, Ti was selectively stripped to 90.1% from Fe and Zr in the organic phase by 1 M HCl. The obtained powder, which was hydrolyzed from an impurity-free solution, was analyzed to a purity of 99.9% by inductively coupled plasma. The TiO2, which has a spherical shape and a diameter of approximately 2 µm according to SEM, was evident by XRD.

scholarly journals Nanocrystallization of Anthocyanin Extract from Red-Fleshed Apple ′QN-5′ Improved Its Antioxidant Effect through Enhanced Stability and Activity under Stressful Conditions

Molecules ◽  
2019 ◽  
Vol 24 (7) ◽  
pp. 1421 ◽  
Author(s):  
Xiang Zhang ◽  
Heqiang Huo ◽  
Xiaohong Sun ◽  
Jun Zhu ◽  
Hongyi Dai ◽  
...  
Keyword(s):  
Storage Time ◽  
Spherical Shape ◽  
Average Diameter ◽  
Anthocyanin Content ◽  
Capacity Loss ◽  
Transmission Electron ◽  
Scavenging Capacity ◽  
Alkaline Conditions ◽  
Regular Spherical Shape ◽  
Scavenging Rates

Red-flesh apples are known as functional fruits because of their rich anthocyanin. The anthocyanin content of the red flesh apple cultivar ′QN-5′ we bred can reach 361 mg·kg−1 (FW), and showed higher scavenging capacity to DPPH radicals, hydroxyl radicals, and superoxide anion radicals, with scavenging rates of 80.0%, 54.0%, and 43.3%, respectively. We used this particular anthocyanin-rich ′QN-5′ apple as material to examine how nanocrystallization affects the antixodiant effect of anthocyanin. The anthocyanin extract was encapsulated with biocompatible zein to form zein-anthocyanin nanoparticles (ZANPs). Transmission electron microscopy (TEM) scanning showed that ZANPs had a regular spherical shape with an average diameter size of 50–60nm. When the ratio of the zein and the anthocyanin was 1:0.5, the results suggested that the encapsulation efficiency (EE) of the ZANPs could reach as high as 92.8%, and that scavenging rate for DPPH radicals was increased from 87.1% to 97.2% compared to the non-nanocrystallized anthocyanin extract. Interestingly, treatment under alkaline conditions (pH 9.0), high temperature (90 °C), and a storage time of 7 days could decrease the scavenging capacity of the ZANPs for DPPH radicals, but this scavenging capacity loss for ZANPs was significantly lower than that observed in the non-nanocrystallized anthocyanin, suggesting the higher stability of ZANPs is caused by encapsulation. These results would provide a theoretical basis for the application of the anthocyanin in scavenging free radicals under stress conditions.

scholarly journals Synthesis and Spectrophotometric Analysis of Microcapsules Containing Immortelle Essential Oil

Molecules ◽  
2021 ◽  
Vol 26 (8) ◽  
pp. 2390
Author(s):  
Iva Brlek ◽  
Anja Ludaš ◽  
Ana Sutlović
Keyword(s):  
Essential Oil ◽  
Spherical Shape ◽  
Spectrophotometric Analysis ◽  
Core Material ◽  
Textile Materials ◽  
Qualitative And Quantitative ◽  
Evaporation Technique ◽  
Cellulose Component ◽  
Regular Spherical Shape

In this study, microcapsules were prepared by solvent evaporation technique using ethyl cellulose component as wall and essential oil as core material. The synthesis of microcapsules was carried out using different oil masses. The analysis of the microcapsules was carried out using field emission scanning electron microscope (FE-SEM) and UV spectrophotometric analysis using absorption spectrophotometer. The obtained results confirm the regular spherical shape and size of the synthesized microcapsules. The qualitative and quantitative spectrophotometric analysis of the microencapsulated immortelle oil was measured at the wavelength of 265 nm. The calibration diagram was used to calculate the unknown concentrations of the microencapsulated oil. The obtained results confirm the application of the presented method as relevant for the possible determination of microencapsulated oil on textile materials.

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