Grinding Method Research Articles

Cocrystallization of methyltestosterone with salicylic acid and 2,2′-disulfanediyldibenzoic acid - Effect on solubility of methyltestosterone and growth of leishmania parasite (amastigotes and promastigotes)

Methyltestosterone is a class II anabolic androgenic steroidal drug, structurally resembled to natural testosterone, produced by body. Two cocrystals of methyltestosterone with thiosalicylic acid and salicylic acid were successfully furnished by using solid state grinding method with the aim to study changes in biological activities and solubility. During cocrystallization the coformer thiosalicylic acid dimerize into 2, 2′-disulfanediyldibenzoic acid and furnished co-crystal I. Characterization of cocrystals 1 and II was carried out on the basis of single-crystal X-ray diffraction technique, IR spectroscopy, DSC/TGA analysis. The solubility of prepared cocrystals I and II were found to be significantly improved in different dissolution media i.e. phosphate buffer (pH 6.8, 7.4), 0.1 N HCl and distill water. Methyltestosterone and both cocrystals were found to be non-cytotoxic while tested against BJ human normal fibroblast cell line. Non-cytotoxic cocrystals I and II were further evaluated for anti-leishmanial activity (amastigotes and promastigotes). Both cocrystal I (IC50 = 11.9 µM) and II (IC50 = 27.2 µM) shows potent anti-leishmanial activity against L. major promastigote (extracellular / in blood parasite stage) and amastigote (intracellular / inside macrophage cell) stage in comparison to the standard drugs miltefosine (IC50 = 25.5 ± 0.42 µM) and methyltestosterone (IC50 = 37.42±0.57 µM). Infected macrophage cellular assay together with AFM analysis are carried out to study the effect of synthesized cocrystals on growth of amastigotes stage of L. major. The promising result demonstrates the effect of cocrystallization on solubility and anti-leishmanial potential of anabolic androgenic steroidal drug methyltestosterone for the first time.

Physical and functional properties of low temperature ground turmeric (Curcuma longa) powder

Turmeric (Curcuma longa) rhizome (var. Salem) sample was ground according to two different grinding parameters viz., four grinding methods and two feed temperatures. The effect of grinding methods and feed temperature on some functional and physical properties was evaluated. The average values of the flow property viz., bulk density (506.78 to 537.94 kg/m3), tapped density (611.35 to 635.72 kg/m3), Hausner ratio (1.150 to 1.225) and compressibility index (13.07 to 18.34%) and functional property viz., water absorption index (3.88 to 4.46), water solubility index (16.17 to 26.51%), water holding capacity (268.40% to 307.19%) and oil absorption index (210.57% to 258.04%) with respect to different grinding methods and feed temperatures varied. The ground sample with chilled water circulation method with the ambient temperature feed (L2T0) was found the most suitable for better flow parameters and functional properties.

Enhancing Solubility and Dissolution Rate of Antifungal Drug Ketoconazole through Crystal Engineering.

To improve the solubility and dissolution rate of the BCS class II drug ketoconazole, five novel solid forms in 1:1 stoichiometry were obtained upon liquid-assisted grinding, slurry, and slow evaporation methods in the presence of coformers, namely, glutaric, vanillic, 2,6-dihydroxybenzoic, protocatechuic, and 3,5-dinitrobenzoic acids. Single-crystal X-ray diffraction analysis revealed that the hydroxyl/carboxylic acid. . .N-imidazole motif acts as the dominant supramolecular interaction in the obtained solid forms. The solubility of ketoconazole in distilled water significantly increased from 1.2 to 2165.6, 321.6, 139.1, 386.3, and 191.7 μg mL-1 in the synthesized multi-component forms with glutaric, vanillic, 2,6-dihydroxybenzoic, protocatechuic, and 3,5-dinitrobenzoic acid, respectively. In particular, the cocrystal form with glutaric acid showed an 1800-fold solubility increase in water concerning ketoconazole. Our study provides an alternative approach to improve the solubility and modify the release profile of poorly water-soluble drugs such as ketoconazole.

Synthesis, characterization, antibacterial properties, mode of action and molecular docking studies of copper pyridyl complexes against drug-resistant bacteria

A series of four new copper complexes containing pyridyl-based ligands of the type [Cu(Cl)2(L)2] were prepared by solid-state methods and evaluated for antibacterial activity. Their elemental analysis showed that the grinding method produced pure complexes. FTIR spectroscopy confirmed the coordination of ligands to copper ions by identifying shifts in vibrational frequencies. Furthermore, their successful synthesis was confirmed by the coordinating bonds being shifted to lower frequencies. Electronic spectra and magnetic susceptibility data proved the complexes to be d9 tetrahedral complexes. Thermal studies of the copper complexes indicated that they had good thermal stability. In the thermal analysis, a recurring pattern emerges as each copper complex experiences multiple mass losses and exhibits characteristic transitions in DSC profiles, shedding light on their distinct thermal behaviors. The mass spectra of the copper complexes showed that the data agreed with the elemental analysis and other elucidation techniques. The complexes displayed characteristic molecular ion peaks and adducts consistent with their calculated masses, substantiating the successful synthesis of these complexes and enhancing understanding of their composition and stability. The copper complexes also displayed solubility in highly polar and heavy solvents thus reduced the chances of forming good-quality crystals. The copper complexes were more effective against Gram-positive bacteria, with CuL4 performing best, notably against MRSA and S. aureus. All of the active complexes were bacteriostatic against MRSA and S. aureus based on the time kill kinetics. Additionally, it was shown that the CuL4 and Cu4PY-H disrupted the S. aureus cell membrane more effectively than the AgSD control. Finally, the CuL4 membrane disruption studies were not significantly different to the AgSD control on MRSA. The results of cell membrane disruption were supported by molecular docking scores, where CuL4 outperformed the other active compounds, and the trends corroborated the experimental results.

Fabrication of PCD face grinding wheel with positive rake angle by femtosecond laser and its performance evaluation in cemented carbide grinding

Super-hard abrasive grinding is considered to be the main approach to realize precision and ultra-precision machining of difficult-to-machine materials such as cemented carbide, engineering ceramics, titanium alloys and superalloy materials encountered. However, heavy grinding force, high grinding temperature and poor surface integrity are prone to be encountered in conventional negative rake angle grinding of difficult-to-machine materials. In response to these problems, a novel concept of positive rake angle grinding is first proposed and an abrasive grain regularly arranged binder-less polycrystalline diamond face grinding wheel with positive rake angle has been designed and fabricated by femtosecond laser ablation. To evaluate the grinding performance of the face grinding wheel with positive rake angle, grinding experiments of YG8 cemented carbide are conducted and compared with the traditional electroplated diamond grinding tool with equivalent abrasive grain dimension and distribution. The results show that compared with the conventional negative rake angle grinding, the normal and tangential forces in positive rake angle face grinding are reduced by 30.3 % ∼ 36.4 % and 21.1 % ∼ 29.3 %, respectively, and the ratio of normal to tangential force is reduced by 12.6 % ∼ 20.3 %. The surface roughness and average depth of subsurface metamorphic layer are also significantly smaller. The laser fabricated polycrystalline diamond face grinding wheel also has better wear resistance in the grinding of cemented carbide. Therefore, it can be concluded that better ground surface quality is obtained by the novel grinding wheel with positive rake angle. The innovative grinding method can fill the research gap on the grinding mechanism of positive rake angle grinding and further enrich the grinding theory of difficult-to-machine materials.

АНАЛИЗ ПРОЦЕССОВ ФОРМИРОВАНИЯ МИКРОПРОФИЛЯ ПОВЕРХНОСТЕЙ ДЕТАЛЕЙ МАШИН НА ЭТАПАХ ОБРАБОТКИ И ПРИРАБОТКИ В УСЛОВИЯХ ГРАНИЧНОГО ТРЕНИЯ

An approach is proposed which is based on the theory of random processes and which allows carrying out an objective comparative analysis of the results of forming of surface roughness profiles of sliding friction joint elements both after machining and during operational run-in. The research relevance is determined by the task of forming a surface roughness profile by various technological methods, which corresponds to or is close to the operational one formed during the running-in of the sliding friction joint elements, that would allow manufacturing products which would start operating in conditions close to normal wear. The studies evaluate the influence of technological factors on forming roughness profiles by turning options and round grinding methods followed by surface plastic deformation by diamond smoothing, electromechanical machining, etc., as well as the influence of the run-in processes carried out on the test bench. A qualitative assessment of the forms of amplitude-frequency characteristics of models forming element surfaces is accepted as the identity criterion of processes forming microprofiles of element surfaces. The paper presents a method of experimental verification of the surface roughness profile for stationarity and ergodicity, which can be used to analyze other random sequences appearing in the practice of tribotechnological research. The construction of autocorrelation functions of the surface roughness profile before and after running-in makes it possible to find out the influence of technological heredity on forming a microprofile while surface machining and running-in of parts. The calculation of indicators to evaluate the theoretical spectral densities of roughness profiles and the construction of amplitude-frequency characteristics of forming surface roughness by various technological methods and during run-in allows choosing an effective method of machining parts, which significantly reduces the run-in time of sliding friction pairs. Studies have shown that surface plastic deformation should be used as the finishing treatment of parts, which allows to obtain a roughness profile of sliding friction surfaces close to the operational one.

Experimental investigation on the feasibility of high-efficiency and precision grinding of silicon carbide ceramics with monolayer brazed diamond wheel

To explore the feasibility of high efficiency and precision grinding of brittle ceramics, the experimental grinding tests were conducted on SiC ceramics with monolayer brazed diamond wheels. The monolayer diamond grinding wheel with 80/100 mesh size diamond grains was brazed using high-frequency induction techniques. The binarization method was proposed to quantitatively characterize the brittle removed areas from the whole ground surface and oblique polishing method was used to assess the subsurface damage depth of the ground SiC samples. The results show that the maximum undeformed chip thickness (agmax) plays a crucial role in the material removal mode. When agmax increases from 0.08 µm to 1 µm, the brittle-removal ratio increases rapidly from 8.20 % to 48.24 % and the subsurface damage depth increase from 3.48 µm to 9.14 µm by 162.6 %. The grinding wheel speed also has a significant influence on the brittle-removal ratio. With the gradual increase of grinding wheel speed (vs) from 20 m/s to 160 m/s, the brittle-removal ratio of the ground surface decreases from 34.24 % to 25.56 %, and the depth of subsurface damage decreases from 5.68 µm to 3.58 µm by 36.97 %. The effect of the grinding depth on the ground surface and subsurface is comparatively not remarkable. The influence of grinding parameters on the grinding process of SiC ceramics indicate that high speed, creep infeed and deep depth grinding method makes it possible to realize high efficiency and low damage machining for SiC ceramics with monolayer diamond wheel.

Mechanosynthesis of Stable Salt Hydrates of Allopurinol with Enhanced Dissolution, Diffusion, and Pharmacokinetics.

Allopurinol (ALO) is a medication that treats gout and kidney stones by lowering uric acid synthesis in the blood. The biopharmaceutics classification system (BCS) IV drug exhibits poor aqueous solubility, permeability, and bioavailability. To overcome the bottlenecks of ALO, salts with maleic acid (MLE) and oxalic acid (OXA) were synthesized using the solvent-assisted grinding method. The novel multicomponent solids were characterized by PXRD, DSC, TGA, FT-IR, and SEM images. The crystal structures of these salts with variable stoichiometry were obtained using Rietveld refinement from the high-resolution PXRD data. The proton from the dicarboxylic acid is transferred to the most basic pyrimidine "N" of ALO. The N-H···N hydrogen-bonded ALO homodimer is replaced by the N+-H···O- ionic interactions in ALO-OXA (2:1:0.4) and ALO-MLE (1:1:1) salt hydrates. The organic salts improved solubility and dissolution up to 5-fold and the diffusion permeability up to 12 times compared to the native drug in a luminal pH 6.8 phosphate buffer medium. The salt hydrates were exceptionally stable during storage at 30 ± 5 °C and 75 ± 5% relative humidity. Superior dissolution and diffusion permeability of the ALO-MLE salt resulted in improved pharmacokinetics (peak plasma concentration) that offers a promising solid dosage form with enhanced bioavailability and lower dosage formulation.

Solid State Fabrication of Copper Nanoclusters and Supraparticles

In this study, we present solid state processes for the fabrication of copper nanoclusters (NCs) and hierarchical supraparticles (SPs). To achieve this, copper salt and thiols are mixed and are then grinded for 10–15 min, and the nano-products are thereby obtained. Interestingly, it was found in this study that the formation of the NCs or SPs is completely dependent on the grinding methods that are used: with mechanical grinding, the products are several nanometer-sized NCs, whereas manual grinding in an agate mortar can obtain Cu SPs with diameters as low as 10 nm all the way up to 200 nm. The photoluminescence emission wavelength of the nano-products is located at ~680 nm. The Stokes shift of the obtained nanomaterials is more than 300 nm. The emission quantum yields of the Cu NCs and SPs are as high as 47.5% and 63%, respectively. Due to their facile fabrication processes and their favorable optical properties, the two as-prepared types of copper nano-materials exhibit great potential for bio-imaging and bio-sensing applications.

Constructing PTFE@LATP composite solid electrolytes with three-dimensional network for high-performance lithium batteries

The NASICON-type lithium aluminum titanium phosphate (LATP) solid-state electrolytes is considered as a promising candidate for next-generation all-solid-state lithium batteries (ASSLBs) with high energy density. However, LATP possesses highly interfacial impedance, causing poor electrochemical performance of ASSLBs and seriously hindering its practical application. Herein, the (polytetrafluoroethylene) PTFE@LATP composite solid electrolytes with three-dimensional network have been constructed by combining sol-gel and solid state grinding methods. The electrochemical performance test results show that the introduction of 24 wt% PTFE can effectively reduce the interface impedance of LATP (LATP:2010.0 Ω, PTFE@LATP:126.9 Ω), increased ion conductivity of LATP (LATP:5.50 × 10−5 S∙cm−1, PTFE@LATP:7.56 × 10−4 S∙cm−1), further significantly improve the electrochemical window (LATP:3.2 V, PTFE@LATP:5.0 V), rate capability (corresponds to 95.2% of the initial discharge capacity) and cycling stability (the capacity of the full cell is changed from 140.1 mAh∙g−1 to 88.3 mAh∙g−1 after 500 cycles at 1 C) of ASSLBs. Mechanism research indicates that PTFE@LATP with the excellent electrochemical performance benefits from PTFE@LATP CSEs with three-dimensional network and electrode possess well interface compatibility, it conducive to preventing the occurrence of interface side reactions and promoting the rapid migration of lithium ions. This work provides a theoretical basis and practical guidance for the further development of CSEs with higher electrochemical performance.

CoCe composite catalyst for the CH4/CO2 reforming reaction: Synergistic effects between Co and Ce species

The greenhouse gases CH4 and CO2 can be use as feedstock to prepare syngas (CO + H2) by CH4/CO2 reforming reaction, and the syngas can be used to produce high value-added chemicals through Fischer-Tropsch reaction. That is, the CH4/CO2 reforming reaction can provide an effective way to rationally use CO2 and CH4. The CoCe catalysts were prepared by impregnation method and grinding method, respectively, and the physicochemical properties were characterized by H2-TPR, XRD, BET, Quasi in-situ XPS and CO2-TPD. The synergistic effects between Co and Ce species can promote the CH4 and CO2 molecules to be continuously and rapidly activated, so that the CoCe catalysts exhibited good catalytic activity for the CH4/CO2 reforming reaction. The preparation methods can affect the dispersion of the Co species and the thermal stability of the oxygen vacancies on the CoCe catalysts to affect catalytic activity. The impregnation method is conducive to the Co species dissolving into the CeO2 lattice to form oxygen vacancies with high thermal stability, and the Co species on the CeO2 surface were in a highly dispersed state, which can provide more stable catalytic activity centers. Thus, the catalysts prepared by impregnation method displayed superior catalytic performances for CH4/CO2 reforming reaction. And the CH4 and CO2 conversions can reach 43.4% and 29.0% at the reaction temperature of 600 °C, respectively.

A grinding process method of solid end mills groove with segmented unequal helical angles by cutting edges offset and interference

Solid end mills with variable helical angles within a certain range can effectively mitigate cutting vibration and enhance the machining quality. However, the grinding process for these helical grooves is complex, and the existing disclosed process method cannot grind those helical grooves accurately. This study proposes a two-pass grinding method for the helical groove with variable helical angles. First, a cutting edge model with variable helical angles is established by edge offset to guide the grinding process. Second, to ensure the required cross-section parameters while avoiding overcutting and edge discontinuity, a novel optimization algorithm for determining the grinding wheel posture, and calculation rules of related process parameters for the two-pass grinding process are proposed. Finally, the verification is conducted and the results show that the maximum relative error of cross-section parameters is 1.254 % in simulation machining, which indicates the theoretical modeling of posture optimization and cutting edge are correct, and the two-pass grinding process is effective. Furthermore, this approach can be extended to grinding other complex structures with helical grooves.

Stable and efficient As2O3 removal from simulated flue gas using Al2O3/CaSiO3 prepared by anhydrous grinding and calcination method

CaSiO3 exhibits good arsenic capture performance, but it falls short of meeting the actual needs of power plants due to its susceptibility to acidic gases that inhibit its arsenic capture ability. In this study, an Al2O3/CaSiO3 adsorbent was prepared by combining the anhydrous grinding and calcining methods. Arsenic vapor capture was conducted in flue gas containing or free of SO2 and HCl within the temperature range of 800–1000 ℃. The research indicated that the preparation method used in this study resulted in uniform Al2O3 doping that was less prone to agglomeration, thereby creating a good pore structure. The Al2O3/CaSiO3 adsorbent exhibited the strongest arsenic capture capacity when the atomic molar ratio of Al/Si was 1:5, with an arsenic capture amount of 871.2 mg/kg, which was significantly higher than the capture capacity of the control group calcium silicate. The doping of Al atoms altered the structure and charge distribution of CaSiO3 silica-oxygen chains, resulting in the formation of Al active sites with higher adsorption energy, which is more favorable for the adsorption of arsenic. Although the Al2O3/CaSiO3 adsorbent reacts with acidic gases to form CaSO4 and CaCl2, which can inhibit arsenic capture, it still maintains a high arsenic capture rate. Al2O3/CaSiO3 has excellent arsenic removal, sintering resistance, and acid resistance, making it a promising composite adsorption material for arsenic removal.

Achieving High Pseudocapacitance Anode SnP2O7@C By an in Situ Self-Nanocrystallization Method for Ultrastable Sodium Storage

Title: High Pseudocapacitance Anode SnP2O7@C by In Situ Self-Nanocrystallization Method for Ultrastable Sodium StorageThe rich resource and cheap price of Na have attracted attention in energy storage research and the market, becoming an optional choice for Li-ion batteries. The large radius of sodium-ion leads to a high diffusion barrier that restricted the development of sodium-ion batteries. Therefore, anodes with high capacity and stable cyclability are urgently addressed before further utilization.The mechanism of sodium-ion batteries can be classified into three categories: intercalation, alloying and conversion. Anode based on alloying and conversion mechanism became a research hotspot due to superior theoretical capacity. In pursuit of surpassing capacity, recent studies concentrated on anode with mixed mechanism, which had the potential to marriage the benefit of alloying and conversion mechanisms. However, the large volume expansion and short lifetime hindered the application in batteries.Here, we demonstrated an ultrastable sodium battery based on a novel anode, pomegranate-like SnP2O7 nanoparticles with a mixed mechanism homogeneously dispersed in the N-doped carbon matrix. Without the constraint of the grinding method, in situ self-nanocrystallization method has been first used to generate ultra-fine SnP2O7 particles.The results of the Ex-situ transmission electron microscope (TEM) characterization exhibited that the size range of SnP2O7 particles was efficiently decreased by the new fabrication method, from 66 to 20nm. During cycling tests, the nanostructure SnP2O7 particles remained well distributed in the N-doped carbon matrix rather than aggregation under long cycling tests. The self-nanocrystallization SnP2O7 nanoparticles ameliorated the diffusion of sodium-ion, which attained the acceleration of reaction kinetics. The N-doped carbon matrix contributed to the conductivity of composite material and meanwhile form strong adhesion with the carbon matrix to maintain the nanostructure SnP2O7 particles active during charge and discharge cycling. The pomegranate-like SnP2O7@C nanomaterial enhanced the pseudocapacitance to attain higher capacity and fast-charging storage. Under the capacitive-controlled behaviour test at 0.4mVs-1, the calculated capacitive showed a dominant contribution of total capacity, made up 75.7% of all. The participation of capacitive promoted avert the slow diffusion of sodium ion and obviate the destruction of the structure. The SnP2O7 carbon matrix anode exhibited superior specific capacity 403 mAh g-1 at 200 mA g-1 and cycling stability (185 mAh g-1 at 1000 mA g-1). The cycling stability of SnP2O7 nanomaterial has been ameliorated by the protection of N-doped carbon. The coulombic efficiency of SnP2O7@C showed no obvious changes and maintained around 100%, while the CE of SnP2O7 had appreciable variation. A new fabrication route of conversion and alloying anode nanomaterial was introduced in this work and has the potential to be utilized in large-scale manufacture. Figure 1

An enzyme-based system for extraction of small extracellular vesicles from plants

Plant-derived nanovesicles (NVs) and extracellular vesicles (EVs) are the next generation of nanocarrier platforms for biotherapeutics and drug delivery. EVs exist not only in the extracellular space, but also within the cell wall. Due to the limitations of existing isolation methods, the EVs extraction efficiency is low, and a large amount of plant material is wasted, which is of concern for rare and expensive medicinal plants. We proposed and validated a novel method for isolation of plant EVs by enzyme degradation of the plant cell wall to release the EVs. The released EVs can easily be collected. The new method was used for extraction of EVs from the roots of Morinda officinalis (MOEVs). For comparison, nanoparticles from the roots (MONVs) were extracted using the grinding method. The new method yielded a greater amount of MOEVs, and the vesicles had a smaller diameter compared to MONVs. Both MOEVs and MONVs were readily absorbed by endothelial cells without cytotoxic effect and promoted the expression of miR-155. The promotion of miR-155 by MOEVs was dose-dependent. More importantly, we found that MOEVs and MONVs were enriched toward bone tissue. These results support our hypothesis that EVs in plants could be efficiently extracted by enzymatic cell wall digestion and confirm the potential of MOEVs as therapeutic agents and drug carriers.

Accelerated Wound Healing with a Diminutive Scar through Cocrystal Engineered Curcumin.

Pharmaceutical cocrystals ( Regulatory Classification of Pharmaceutical Co-Crystals Guidance for Industry; Food and Drug Administration, 2018) are crystalline solids produced through supramolecular chemistry to modulate the physicochemical properties of active pharmaceutical ingredients (APIs). Despite their extensive development in interdisciplinary sciences, this is a pioneering study on the efficacy of pharmaceutical cocrystals in wound healing and scar reducing. Curcumin-pyrogallol cocrystal (CUR-PYR) was accordingly cherry-picked since its superior physicochemical properties adequately compensate for limitative drawbacks of curcumin (CUR). CUR-PYR has been synthesized by a liquid-assisted grinding (LAG) method and characterized via FT-IR, DSC, and PXRD analyses. In vitro antibacterial study indicated that CUR-PYR cocrystal, CUR+PYR physical mixture (PM), and PYR are more effective against both Gram-negative (Pseudomonas aeruginosa and Escherichia coli) and Gram-positive (Staphylococcus aureus and Bacillus subtilis) bacteria in comparison with CUR. In vitro results also demonstrated that the viability of HDF and NIH-3T3 cells treated with CUR-PYR were improved more than those received CUR which is attributed to the effect of PYR in the form of cocrystal. The wound healing process has been monitored through a 15 day in vivo experiment on 75 male rats stratified into six groups: five groups treated by CUR-PYR+Vaseline (CUR-PYR.ung), CUR+PYR+Vaseline (CUR+PYR.ung), CUR+Vaseline (CUR.ung), PYR+Vaseline (PYR.ung), and Vaseline (VAS) ointments and a negative control group of 0.9% sodium chloride solution (NS). It was revealed that the wounds under CUR-PYR.ung treatment closed by day 12 postsurgery, while the wounds in other groups failed to reach the complete closure end point until the end of the experiment. Surprisingly, a diminutive scar (3.89 ± 0.97% of initial wound size) was observed in the CUR-PYR.ung treated wounds by day 15 after injury, followed by corresponding values for PYR.ung (12.08 ± 2.75%), CUR+PYR.ung (13.89 ± 5.02%), CUR.ung (16.24 ± 6.39%), VAS (18.97 ± 6.89%), and NS (20.33 ± 5.77%). Besides, investigating histopathological parameters including inflammation, granulation tissue, re-epithelialization, and collagen deposition signified outstandingly higher ability of CUR-PYR cocrystal in wound healing than either of its two constituents separately or their simple PM. It was concluded that desired solubility of the prepared cocrystal was essentially responsible for accelerating wound closure and promoting tissue regeneration which yielded minimal scarring. This prototype research suggests a promising application of pharmaceutical cocrystals for the purpose of wound healing.

THEORETICAL RESEARCH OF PROCESS REGULARITIES OF GRINDING STRUCTURAL-HETEROGENEOUS ORGANIC MATERIALS

For the efficient functioning and successful development of the animal production sector, the key condition is correct feeding of animals. This feeding is only possible if enough feed is produced, nutrient losses during harvesting are reduced, and feed is correctly prepared for feeding. The introduction of concentrated feed helps to achieve a balance between energy, protein and amino acid content in the animal ration. Technologists compose and select components of feed rations based on the species, age group, morphological and biological characteristics of animals, as well as other factors. Despite the chosen technology and feeding strategy, concentrated feeds such as processed cereals based on wheat, barley, corn and other crops continue to be the main source of nutrients for animals. The quality of grinding concentrated feed is important for animal productivity. This treatment results in the formation of numerous particles with a larger surface area, which promotes faster digestion and better absorption. Grinding is one of the most high-energy processes used in animal feed technology. Since plant residues are structurally uneven, this makes it difficult to use conventional grinding methods efficiently, which reduces their energy efficiency and requires the use of several grinding stages with appropriate equipment. In order to ensure efficient processing of agricultural plant residues, it is important to create an appropriate technical infrastructure, given the significant energy costs associated with traditional processes of preparing biomass for granulation. To do this, it is necessary to conduct research aimed at solving the problem of energy-efficient grinding of structurally heterogeneous materials, in particular materials that contain a large amount of moisture. This is what determines the relevance of this research topic.

Nanoplasmonic engineering construction of europium oxide incorporated on graphene oxide surface and its nano heterojunction through the zinc oxide nanoparticles for water-clean

The redesigned engineering building of europium (III) oxide nanoparticles and zinc oxide nanoparticles on the electron carrier surface of graphene oxide nanosheet is the main target to increase the effectiveness of the electron transfer and photogeneration of reactive oxygen species for the photocatalytic and adsorption process. The hybrid nanocomposite fabricates by the precipitation and grinding method and characterization of the nanocomposite perform by various techniques, such as field emission scanning electron microscopy (FEG-SEM), FT-IR spectroscopy, zeta potential, and UV–visible spectrophotometer. The hybrid nanocomposite's stability is performed through the cyclic voltammetry technique by measuring the CV-cycle's multi-cycles. The adsorption process and photocatalytic activity are detected by using the UV–visible spectroscopy, where the degradation efficiency of characterized absorption peaks of pollutants was followed. The ability of the modified surface of hybrid nanocomposite against the pollutants for example methylene blue dye, p-nitrocatechol, p-nitrophenol, and removal of the chromium heavy metal to obtain the clean water was performed successfully. The rate constant and efficiency of the fabricated nanocatalyst were calculated, the photodegradation of methylene blue was 0.005 min−1 (efficiency 68 %), in sodium hydroxide was 0.03764 min−1 (efficiency 94 %), and in hydrogen peroxide was 0.02837 min−1 (efficiency 96 %). The p-nitrocatechol has photodegradation at 5.7564 min−1 (efficiency 89 %), p-nitrophenol 0.00492 min−1 (efficiency 74 %), and chromium ions adsorption appeared at 0.13381 min−1 (efficiency 54 %). The study confirms the hybrid nanocomposite is a promising candidate as a novel membrane for clean water production.

Experimental Research and Transfer Matrix Method for Analysis of Transmission Loss in Multilayer Constructions with Devulcanized Waste Rubber

According to circular economy principles, the recycling and reuse of tyre rubber waste are among the most advanced and ecological waste disposal technologies. Each year, about 19 million tons of tyres are produced, and this number increases every year. One of the most innovative ways to recycle rubber waste is devulcanization. There are many methods of rubber devulcanization, but the most popular is chemical devulcanization. Also, pre-process treatment is important before devulcanization. In this article, devulcanized rubber granules were used for the preparation of rubber samples. Two of the samples were obtained via the grinding method and one via chemical devulcanization. In total, 15 different rubber samples were produced for experimental measurements. Multilayer constructions, with two solid layers of plasterboard on both sides (GKB (a standard gypsum board) and GKFI (an enhanced-strength and surface-hardness gypsum board)) and the porous acoustic material of the rubber sample inside, were produced. Measurements were made in an impedance tube and compared with the results of a transfer matrix method (TMM) analysis. The same trends of resonant frequencies were determined. According to the results, the resonant frequencies depended on the thickness of the material, since transmission loss (TL) values depended on the mass of the construction. According to the test results of transmission loss, constructions with 50 mm thick rubber samples had results that were, on average, 3 dB better than those of structures with 25 mm thick samples and 5 dB better than those of structures with 12 mm thick rubber samples. In addition, it was found that higher-density plasterboards (GKFI) increased the overall transmission loss value of the structure by 5 dB. The same trends were determined using the TMM method. The test results showed that multilayered constructions with devulcanized waste rubber had high transmission loss results and could be used for sound-insulating structures.

Subsurface damage inhibiting and synchronous removal behavior of Cf/SiC composites with laser-induced controllable ablation during abrasive belt grinding

Aiming at improving the machinability of Cf/SiC composites, this study proposed laser-induced controlled ablation grinding (LICAG) method. Cf/SiC composites samples with various ablating depths were prepared through picosecond laser, which were then ground by abrasive belt. The results showed that Cf/SiC composites were sublimated in laser ablating zone, resulting in dentate grooves covered with loose SiO2 oxides products. The grinding force and temperature during LICAG could be decreased by up to 64.0% and 58.8%, respectively, compared with conventional grinding (CG). Carbon fiber fracture was reduced, SiC matrix and carbon fibers were removed almost synchronously during LICAG; therefore, the surface quality was improved. Moreover, subsurface micro cracks were found near the grinding surface but did not propagate downward along the fibers. Grinding chips of CG were primarily broken fibers and broken SiC matrix; on the contrary, those generated during LICAG were mostly regular fiber bundles connected to SiC matrix.