Application of NLO and Antibacterial Activity of Tricine Doped Potassium Metal Ion Crystal

We have successfully produced Tricine Potassium Nitrate (TPN) single crystal synthesis using the solution growth method in this study. The powder X-ray diffraction (PXRD) technique was used to identify the phases of TPN crystals. Fourier transform infrared (FT-IR) analysis was performed to examine the functional groups contained in the produced crystals. To measure optical transparency, a UV-VIS-NIR investigation was conducted between 200 and 800nm. TPN crystal's photoluminescence (PL) spectrum was recorded. Vickers' hardness tester was used to investigate the mechanical characteristics of the formed crystal.Thermal gravimetric/differential thermal analysis was used to investigate the thermal behaviors of the produced crystals. The surface morphology of the formed crystal was determined using a field emission scanning electron microscope. Wet etching experiments were used to investigate the TPN crystal's growth feature. The shock damage threshold technique was used to determine the shock strength at which the crystal poses a risk. The Kurtz-Perry technique was used to investigate the effectiveness of the developed crystals' second harmonic generation (SHG). The antibacterial activity of TPN grown crystal against various standard bacterial strains.

Effects of ultrasonic surface rolling and plasma nitriding on microstructure and properties of 690TT alloy

To enhance surface mechanical properties of 690TT alloy, a surface hardening layer was obtained by ultrasonic surface rolling treatment (USRT) and plasma nitriding (PN). The surface morphology, mechanical properties, wear performances and corrosion performance were investigated by XRD, TEM, using a hardness tester, tensile tester, wear tester and electrochemical workstation in simulated sea water, respectively. The results showed that USRT as the pre-treatment can strengthen the performance of PN treatment samples. The USRT+PN treated sample showed existence of dislocation tangles and twin grains. Corrosion resistance in simulated sea water was enhanced. The surface microhardness increased by 180 % compared with the untreated sample, the cross-sectional hardness gradually decreased till the depth of 1mm. The tensile strength increased by a factor of 90% while the elongation decreased by only 40%. The wear scar was narrower and shallower than the untreated sample and the wear rate was significantly dropped. This paper aims at providing a new method for surface strengthening of 690TT alloy.

Combined Effect of a Laser Cladded Coating and Surface Texture on Tribological Performance Under Dry Sliding and Starved Lubrication

Fe-based alloy coating was laser cladded on gray cast iron using Ni-Cu alloy as an intermediate layer. The cross section of the laser cladded coating was characterized by optical microscopy (OM), scanning electron microscopy (SEM) equipped with energy dispersive spectrometry (EDS), X-ray diffraction (XRD), and a Vickers hardness tester. A microdimple texture was created by reciprocating an electrolyte jet with prefabricated mask (REJP) machining on an Fe-based alloy coating. The tribological performances of untextured and textured coatings were examined through interrupted wear tests using an in-house developed reciprocating ball-on-plate tribotester under dry sliding and starved lubricated conditions. The results show that the presence of microdimple edges in the nonconformal contact region has a detrimental effect on the friction performance under dry sliding. However, the microdimples can be beneficial for trapping debris to preserve a smoother contacting surface and thus a lower volume wear track compared to untextured coatings. Due to its role in oil reservoirs and debris entrapment, the microdimple textured coating can maintain a low friction coefficient for a long time period after lubricant oil cutoff and results in a lower volume wear track under starved lubrication. Graphical abstract

Contriving and Assessment of Magnesium Alloy Composites Augmented with Boron Carbide VIA Liquid Metallurgy Route

In modern engineering low-density composites plays a vital role of which magnesium alloys are very effective due to its high strength with better corrosion resistance and neat cast ability. In this work a micron sized Boron carbide ceramic (B4C) of about 100 microns is diffused as a reinforcement with AZ91 for preparing a magnesium metal matrix composite (MMMC) through stir casting route. A modified pit furnace setup is used for doing stir casting with varying volume fractions of 0％ and 3% of boron carbide for doing the composites. Furthermore mechanical and metallurgical properties like Tensile test is made through universal testing machine, Micro-hardness through Vickers hardness tester and Micro structure through Optical Microscopy is done for investigation.

Production and Assessment of AZ91 Reinforced with Nano SiC through Stir Casting Process

Magnesium, a light weight alloy used in multiple engineering industrial applications because of its good Physical, Chemical and Thermal characteristics. Magnesium composites play an important role in partial or entire replacement of numerous alloys.This current work deals with Nano silicon carbide of about 100nm was incorporated with AZ91magnesium alloy through liquid state composite processing. Two samples are made using 0% Nano SiC and 3% Nano SiC and are characterized through tensile test in Universal Testing Machine, Micro hardness test in Vickers hardness tester and Microstructure in Optical Microscopy. From the study it was clear that there is a peak increase in hardness of about 36% when compared to as casted AZ91.

Study of the technological properties of excipients in the development of the composition of orally dispersible tablets

Introduction. The article presents the results of studying the technological properties of individual excipients widely used in the compositions of existing orally dispersed tablets (ODT) for subsequent planning a multifactorial experiment. Samples of excipients were analyzed according to such pharmacopoeial indicators as description, flowability, bulk density, compressibility, fractional composition, solubility in water.Aim. The aim of the work is to create a list and study the technological properties of candidate substances for the role of auxiliary substances in the composition being developed by the ODT.Materials and methods. The technological properties of excipient samples were studied according to the methods of the State Pharmacopoeia of the XIV edition using the flowability tester GTL (ERWEKA, Germany), the bulk density tester SVM 221 (ERWEKA, Germany), the tablet press PGR-10 (LabTools, Russia) and the tablet hardness tester TBH 125 TDP (ERWEKA, Germany).Results and discussion. As a result of the study, experimental data on the technological properties of excipient samples were collected, and the selected samples were compared according to pharmaceutical and technological indicators.Conclusion. In the course of the study, a list of auxiliary substances for the development of the composition of ODT was formed and studies of their technological properties were carried out. The obtained experimental data will allow to develop an optimal matrix of a multifactorial experiment for the development of the composition of ODT and justify the choice of excipients.

DEVICES FOR DETERMINING THE STRENGTH OF SNOW AND ICE FORMATIONS

В статье представлен анализ существующих средств определения прочности снежно-ледовых образований, выявлены их недостатки, преимущества и отличительные способности. Целью данной работы является разработка компактных средств измерения прочности компонентов дорожных покрытий и обеспечения контроля качества уплотнения полотна сооружаемых зимних дорог по глубине покрытия. Предложено техническое решение, которое позволяет достичь более высокого технического результата по сравнению с известными аналогами, который заключается в повышении точности измерений, упрощении фиксации шарового элемента в корпусе, обеспечении фиксации подвижных элементов при транспортировке и расширении функциональных возможностей за счет определения прочности на поверхности и по глубине снежного покрова с наконечниками разного профиля, а также позволяет снизить стоимость изготовления и трудоемкость работ при измерениях. Предложенный прибор (твердомер) позволяет расширить область применения, как для свежевыпавшего снега, так и для лежалого, за счёт применения разных нижних поверхностей профиля наконечников в виде конуса, цилиндра или шара. Шаровая поверхность увеличивает площадь соприкосновения нижней поверхности его со снежными образованиями для свежевыпавшего снега. Прибор спроектирован, изготовлен и позволяет определять прочностные свойства снежно-ледовых образований при выполнении научно-исследовательских работ. The article presents an analysis of the existing means for determining the strength of snow-ice formations, reveals their disadvantages, advantages and distinctive abilities. The purpose of this work is to develop compact means for measuring the strength of road pavement components and ensuring quality control of the compaction of the roadbed of winter roads under construction by the depth of the pavement. A technical solution is proposed that allows achieving a higher technical result in comparison with known analogues, which consists in increasing the measurement accuracy, simplifying the fixing of the ball element in the housing, ensuring the fixation of the moving elements during transportation and expanding the functionality by determining the strength on the surface and in depth snow cover with tips of different profiles, and also allows you to reduce the manufacturing cost and laboriousness of work during measurements. The proposed device (hardness tester) allows you to expand the field of application, both for freshly fallen snow, and for old, due to the use of different lower surfaces of the profile of the tips in the form of a cone, cylinder or ball. The spherical surface increases the contact area of ​​its lower surface with snow formations for freshly fallen snow. The device has been designed, manufactured and allows to determine the strength properties of snow-ice formations during scientific research.

Synthesis and Characterization of Ti-Sn Alloy for Orthopedic Application

Titanium (Ti)-based alloys (e.g., Ti6Al4V) are widely used in orthopedic implant applications owing to their excellent mechanical properties and biocompatibility. However, their corrosion resistance needs to be optimized. In addition, the presence of aluminum and vanadium cause alzheimer and cancer, respectively. Therefore, in this study, titanium-based alloys were developed via powder metallurgy route. In these alloys, the Al and V were replaced with tin (Sn) which was the main aim of this study. Four sets of samples were prepared by varying Sn contents, i.e., 5 to 20 wt. %. This was followed by characterization techniques including laser particle analyzer (LPA), X-ray diffractometer (XRD), scanning electron microscope (SEM), computerized potentiostate, vicker hardness tester, and nanoindenter. Results demonstrate the powder sizes between 50 and 55 µm exhibiting very good densification after sintering. The alloy contained alpha at all concentrations of Sn. However, as Sn content in the alloy exceeded from 10 wt. %, the formation of intermetallic compounds was significant. Thus, the presence of such intermetallic phases are attributed to enhanced elastic modulus. In particular, when Sn content was between 15 and 20 wt. % a drastic increase in elastic modulus was observed thereby surpassing the standard/reference alloy (Ti6Al4V). However, at 10 wt. % of Sn, the elastic modulus is more or less comparable to reference counterpart. Similarly, hardness was also increased in an ascending order upon Sn addition, i.e., 250 to 310 HV. Specifically, at 10 wt. % Sn, the hardness was observed to be 250 HV which is quite near to reference alloy, i.e., 210 HV. Moreover, tensile strength (TS) of the alloys were calculated using hardness values since it was very difficult to prepare the test coupons using powders. The TS values were in the range of 975 to 1524 MPa at all concentrations of Sn. In particular, the TS at 10 wt. % Sn is 1149 MPa which is comparable to reference counterpart (1168 MPa). The corrosion rate of Titanium-Sn alloys (as of this study) and reference alloy, i.e., Ti6Al4V were also compared. Incorporation of Sn reduced the corrosion rate at large than that of reference counterpart. In particular, the trend was in decreasing order as Sn content increased from 5 to 20 wt. %. The minimum corrosion rate of 3.65 × 10−9 mm/year was noticed at 20 wt. % than that of 0.03 mm/year of reference alloy. This shows the excellent corrosion resistance upon addition of Sn at all concentrations.

Hydroxyapatite Film Coating by Er:YAG Pulsed Laser Deposition Method for the Repair of Enamel Defects

There are treatments available for enamel demineralization or acid erosion, but they have limitations. We aimed to manufacture a device that could directly form a hydroxyapatite (HAp) film coating on the enamel with a chairside erbium-doped yttrium aluminum garnet (Er:YAG) laser using the pulsed laser deposition (PLD) method for repairing enamel defects. We used decalcified bovine enamel specimens and compacted α-tricalcium phosphate (α-TCP) as targets of Er:YAG-PLD. With irradiation, an α-TCP coating layer was immediately deposited on the specimen surface. The morphological, mechanical, and chemical characteristics of the coatings were evaluated using scanning electron microscopy (SEM), scanning probe microscopy (SPM), X-ray diffractometry (XRD), and a micro-Vickers hardness tester. Wear resistance, cell attachment of the HAp coatings, and temperature changes during the Er:YAG-PLD procedure were also observed. SEM demonstrated that the α-TCP powder turned into microparticles by irradiation. XRD peaks revealed that the coatings were almost hydrolyzed into HAp within 2 days. Micro-Vickers hardness indicated that the hardness lost by decalcification was almost recovered by the coatings. The results suggest that the Er:YAG-PLD technique is useful for repairing enamel defects and has great potential for future clinical applications.

Effect of TiB2 Content on Properties of Nickel-Coated Graphite Self-Lubricating Coating Prepared by Laser Cladding

To improve the anti-wear and friction-reducing properties of self-lubricating coatings, Ni60/Nickel-coated graphite/TiB2 composite coatings with different contents were prepared by laser cladding. The coating properties were characterized by X-ray diffractometer (XRD), scanning electron microscope (SEM), energy spectrometer (EDS), electrochemical workstation, micro-Vickers hardness tester, and friction and wear tester. The results showed that with the increase in TiB2 content, the graphite morphology changed from spherical at 0 wt.% TiB2 content to a little black graphite alone at 14 wt.% TiB2 to irregular agglomerates at 22 wt.% TiB2. Furthermore, the hardness of the coatings increased with increasing TiB2 content, and the 63% Ni60 + 15% nickel-coated graphite + 22% TiB2 coating had the highest hardness. TiC and Cr7C3 were generated in the coatings with the addition of nickel-coated graphite, creating a dispersion reinforcement effect, so that the hardness of these coatings was higher than that of the 86% Ni60 + 0% nickel-coated graphite + 14% TiB2 coating without the addition of nickel-coated graphite. In addition, the 71% Ni60 + 15% Ni-coated graphite + 14% TiB2 coating had the lowest friction coefficient, wear loss, and wear volume, thus exhibiting excellent friction reduction and anti-wear properties. The 71% Ni60 + 15% nickel-coated graphite + 14% TiB2 coating had excellent corrosion resistance.