Enhancement Of Purity Research Articles

An investigation on purity enhancement through hydrofluoric acid treatment in graphite powder derived from coconut shell

The present research emphasizes a novel approach for synthesizing graphite powder derived from coconut shell (CS) as a precursor, particularly focusing on investigating the effects of hydrofluoric acid (HF) in removing silica and other impurities. The cost-effective pyrolysis technique employed in synthesizing graphite powder entails heating CS to 900 °C, followed by treatment with HF at varying sample-to-acid ratios. Several characterization methods are used to validate the successful synthesis of graphite powder, such as X-ray Diffraction (XRD), Raman Spectroscopy, Fourier-transform Infrared Spectroscopy (FTIR), and Scanning Electron Microscopy (SEM). XRD analysis shows a distinctive graphitic structure, with Gr14 (graphite prepared with a CSCP to HF ratio of 1:4) exhibiting a high graphitization degree of 93.02 %, indicative of excellent crystal structure and high-quality graphite. FTIR analysis of coconut shell charcoal powder (CSCP) reveals the presence of various oxygen-related functional groups, effectively removed by HF washing, leading to graphite with minimal impurities. The Raman spectra of Gr14 demonstrate fewer defects and a more organized structure than other samples. SEM image of CSCP reveals particles with non-uniform morphologies, while the EDX spectra indicate that Gr14 consists of 97.84 % carbon. Treating CSCP with HF enhances the electrical conductivity of the graphite, with Gr14 exhibiting a higher conductivity value. TGA results reveal the improved thermal stability of the graphite. The residual weight of Gr14 is maximum, confirming its exceptional thermal stability and purity. The findings suggest that HF has a significant influence on improving the purity of CS-derived graphite. The study concludes that, among the prepared samples, Gr14 exhibits favorable characteristics, such as minimal impurities, superior crystal structure, higher carbon content, good electrical conductivity, high thermal stability, and fewer defects, comparable to pure graphite. Future research in this study aims to use CS-derived graphite powder for synthesizing nanomaterials like graphene oxide (GO) and reduced graphene oxide (rGO).

Membrane pre-concentration as an efficient strategy to enhance the enrichment of rare earth by MgO precipitation

Taking advantage of the environmentally-friendly properties of a magnesium salt leaching agent, magnesium oxide (MgO) was used as a precipitant to enrich rare earth (RE) from leaching liquor in the magnesium salt system. This approach not only tackles the issue of ammonia–nitrogen pollution but also enables efficient magnesium recycling. However, due to the high concentration of magnesium ions and the low concentration of RE ions in the leaching solution, the precipitation kinetics of RE concentrates are sluggish, leading to low RE purity in the resulting precipitated product. In this work, we proposed a novel strategy that combines complexation-ultrafiltration (UF) pre-concentration with subsequent MgO precipitation to enhance the hydrolysis of MgO, promoting the precipitation of RE. We further improved the RE enrichment efficiency by optimizing membrane type, complexing agent selection, concentration levels, precipitation temperature, and MgO dosage. Under the conditions of concentrating the leaching solution using optimal UF membrane and employing glyphosate as the complexing agent, the RE ions concentration increased from 101 to 3940 mg/L, and we successfully separated magnesium ions with a separation factor of 36.4. A comparison between direct MgO precipitation and the pre-concentration approach revealed an 80 % reduction in precipitation time and an 80 % decrease in MgO usage with pre-concentration. Furthermore, this combined process led to an 8 % increase in RE recovery and a 2.8-fold enhancement in RE purity, and similar results were obtained when using actual mine leaching solutions. Additionally, the glyphosate present in the UF permeate and the precipitated mother liquor can be efficiently reclaimed through resin adsorption. This proposed process holds significant potential for engineering applications aimed at enriching RE.

Small ubiquitin-like modifier-tag and modified protein purification significantly increase the quality and quantity of recombinant African swine fever virus p30 protein.

African swine fever (ASF) is a highly virulent and contagious viral disease caused by the ASF virus (ASFV). It has a significant impact on swine production throughout the world, while existing vaccines and specific treatments remain ineffective. ASFV p30 is a potent antigenic protein that induces protective antibodies immediately after infection; however, most recombinant p30 is insoluble. This study aimed to improve the solubility, yield, and purity of recombinant p30 by tagging it with a small ubiquitin-like modifier (SUMO) and modifying the protein purification process. SUMO fused with ASFV p30 (SUMO-p30) and p30 alone were cloned and expressed in Escherichia coli. SUMO-p30 and p30 solubility and expression levels were analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). Protein purification was modified by combining ammonium sulfate precipitation method with affinity chromatography. In addition, large-scale production of all versions of p30 were compared using SDS-PAGE and western blotting, and the purified p30 was used to develop the indirect enzyme-linked immunosorbent assay (ELISA). The solubility and expression levels of SUMO-p30 were dramatically enhanced compared with that of p30. Modification of the purification process significantly increased purified and soluble SUMO-p30 and p30 yields by 6.59 and 1.02 μg/mL, respectively. Large-scale production confirmed that this procedure increased the quantity of recombinant p30 while maintaining protein purity and immunogenicity. The p30-based indirect ELISA was able to discriminate between positive and negative serum samples with statistically significant differences in mean optical density 450 values (p < 0.001). This study demonstrates the enhancement of solubility, purity, and yield of ASFV p30 expressed in E.coli by SUMO fusion tagging and combining ammonium sulfate precipitation with affinity chromatography for protein purification. These positive effects were sustained in large-scale production. Cleavage and removal of hexahistidine-SUMO tag from the fusion protein by protease may not be suitable when handling a large amount of the protein. However, the SUMO-fused p30 retained strong immunoreactivity to convalescent swine serum, indicating its application in immunization and diagnostic purposes. The expression and purification procedures in this study could be applied to increase solubility, quality, and quantity of other recombinant proteins as well.

Cleaning Process of Diosgenin from Dioscorea nipponica

This investigation employed HPLC and LC-MS techniques to elucidate the enzymolysis and acid hydrolysis mechanisms of diosgenin obtained through a cleaning process. The findings revealed that the enzymolysis led to the cleavage and subsequent recombination of the glycosidic bond at the C-26 position of protodioscin, resulting in the formation of dioscin present in the enzymatic hydrolysis filter residue. Leveraging this observation, a streamlined and eco-friendly method for diosgenin extraction was devised. Incorporating the Box-Behnken response surface methodology alongside wastewater assessment, the optimal parameters for the cleaning process were established: a sulfuric acid concentration of 3 mol · L−1, a solid–liquid ratio of 1:10, an acid hydrolysis temperature of 100 °C, and an acid hydrolysis duration of 3 h. Under these parameters, the yield and purity of diosgenin were 31.07±0.56% and 72.30±0.24% respectively. When benchmarked against the direct acid hydrolysis approach, there was an increase of 133.08% in diosgenin yield, 44.08% enhancement in diosgenin purity, 50% reduction in wastewater generation and acid utilization, and an 83.57% decrease in wastewater’s chemical oxygen demand (COD). This optimized cleaning process is viable for large-scale production and offers a sustainable method for diosgenin production.

Simulation of carbon dioxide direct air capture plant using potassium hydroxide aqueous Solution: Energy optimization and CO2 purity enhancement

While various methods of direct air capture (DAC) technology have been implemented, its widespread effectiveness hinges on achieving optimal design and process improvements, largely owing to the high energy costs involved. Literatures reports a substantial heat demand for high-temperature aqueous solutions DAC (HT DAC), ranging from 1420 to 2250 kWh per ton of CO2, accompanied by electricity consumption rates varying from 366 to 2790 kWh per ton of CO2. The present study adopts the HT DAC method with an aqueous KOH absorbent as its focus, aiming to mitigate energy consumption. Given that a substantial portion of energy consumption in comparable processes can be attributed to the calciner and slaker units, our research centers its attention on the Air Separation Unit (ASU) and the steam cycle unit, investigating their impact on the system's production capacity, the enhancement of CO2 purity, and the augmentation of equipment thermal recovery. Process optimization, results a remarkable increase in heat recovery (21.1 %) and significant reductions in utilities consumption. The outcomes indicate that this facility has the capacity to annually capture around 1.1 million tons of CO2 with a purity of 99 mol% for utilization across various industries. The process design necessitates 5.24 gigajoules (GJ) of heat and 343 kW-hours (kWh) of electricity per ton of captured CO2. Notably, in addition to fulfilling the internal electricity requirements, the facility can export 8 MWh of electricity per ton of captured CO2 to the grid.

An adaptive optical technique for structured beam generation based on phase retrieval using modified Gerchberg–Saxton algorithm

Generation of high-purity structured light beams is challenging due to transverse phase aberrations in the optical setup consisting of components such as spatial light modulators (SLMs), lenses, and mirrors. Several phase compensation approaches have been explored in previous work, of which the Gerchberg–Saxton(GS) phase retrieval algorithm has been quite popular. In this paper, we have proposed and experimentally demonstrated a modified GS algorithm based on aperture optimization for phase compensation and compared its performance for a wide range of topological charges using inline, pre-, and post-phase compensation techniques. We find that the post-compensation configuration provides the best performance, and by employing such phase compensation we can achieve a 35% enhancement in modal purity of the generated orbital angular momentum (OAM) beam while reducing the nearest neighbor cross-talk by 9.37 dB.

Unraveling the Role of Liquid Metal Catalysts in Electrochemical Growth of Solar Si from SiO2 in CaCl2-Based Molten Salt: Enhancement of Crystallization, Purity, and Photoresponse

Unraveling the Role of Liquid Metal Catalysts in Electrochemical Growth of Solar Si from SiO₂ in CaCl₂-Based Molten Salt: Enhancement of Crystallization, Purity, and Photoresponse

Ultrahigh-resolution full-color micro-LED array with enhanced efficiency based on a color conversion technique

Micro-light emitting diodes (μLEDs) with remarkable advantages are becoming mainstream in next-generation display technologies such as augmented reality/virtual reality displays. However, further development of μLEDs still faces significant challenges, including mass transfer yield. Here, we report color conversion layer (CCL)-based, full-color, highly efficient μLED arrays as a solution to address this challenging issue. Further amalgamating CCL with color purity enhancement film enables us to realize 7 μm×7 μm subpixel fluorescent arrays with a color gamut of 95.34% in DCI-P3, resulting in an overall 1588 PPI (pixel per inch). Our results provide a promising technique for fabricating higher PPI-based next-generation display technology.

Effect of the annealing treatment on structural and transport properties of thermoelectric Sm y (Fe x Ni1−x )4Sb12 thin films

The crystallographic and transport properties of thin films fabricated by pulsed laser deposition and belonging to the Sm y (Fe x Ni1-x )4Sb12 filled skutterudite system were studied with the aim to unveil the effect exerted by temperature and duration of thermal treatments on structural and thermoelectric features. The importance of annealing treatments in Ar atmosphere up to 523 K was recognized, and the thermal treatment performed at 473 K for 3 h was selected as the most effective in improving the material properties. With respect to the corresponding bulk compositions, a significant enhancement in phase purity, as well as an increase in electrical conductivity and a drop in room temperature thermal conductivity, were observed in annealed films. The low thermal conductivity, in particular, can be deemed as deriving from the reduced dimensionality and the consequent substrate/film interfacial stress, coupled with the nanometric grain size.

TAF1D Functions as a Novel Biomarker in Osteosarcoma.

Background: The most frequent primary bone cancer in teenagers, osteosarcoma (OS), is particularly aggressive with a high mortality rate. Methods: By combining public databases, OS and non-cancer samples were obtained. The Wilcoxon test and standardized mean difference (SMD) were utilized to evaluate the mRNA expression level of TATA-box binding protein associated factor, RNA polymerase 1 subunit D (TAF1D). The potential of TAF1D to discriminate OS samples from non-cancer samples was revealed by summary receiver operating characteristic curve (sROC). To investigate the prognostic significance, Kaplan‒Meier curve and univariate Cox analysis were performed. Immunohistochemistry (IHC) was used to determine the TAF1D protein expression level. ESTIMATE algorithm and TIMER2.0 database were used to reveal the association between TAF1D expression and the immune microenvironment. Enrichment analysis and potential drug prediction were performed to clarify the underlying molecular mechanisms and possible therapeutic directions of TAF1D. Ultimately, the transcription factors (TFs) and the TAF1D binding site were predicted based on the Cistrome and JASPAR databases. Results: TAF1D was upregulated in OS at the mRNA and protein levels and possessed robust discriminatory power. TAF1D upregulation was suggestive of worse prognosis and enhancement of tumor purity in OS patients. The cell cycle was the most significantly enriched pathway, and NU.1025 was considered to be the potential target agent. Finally, MYC was identified as a TF that regulates the expression of TAF1D. Conclusions: Altogether, TAF1D has the potential to serve as a biological marker and therapeutic target in OS, which could offer new perspectives for OS treatment.

Enhancing the materials circularity: from laboratory waste to electrochemical capacitors

Enhancing the circularity of materials is at the forefront of sustainability; this paper addresses smart reuse of a laboratory waste, i.e., paper towels, as one of the main components (electrodes) in an energy storage device (electrochemical capacitor, EC). We obtained carbon from wastepaper towels by converting them into cellulose through alkali treatment, subsequent enhancement of porosity via nitric acid reflux, and enhancement of chemical purity via controlled annealing. The porous carbon thereby optimized is characterized for chemical structure, surface structure, and morphology as well as electrochemical charge storability. The carbon sample obtained at 800 °C showed graphitization and interconnected morphology displaying a combination of micro and mesopores, superior surface area (∼528 m2/g), desirable pore diameter for efficient ion adsorption (∼3.3 nm), and specific capacitance ∼230 F/g in 1 M KOH and ∼160 F/g in 1 M Na2SO4 electrolytes. Symmetrical electrochemical capacitors are also fabricated using the best performing carbon electrode in the above two electrolytes, which delivered desirable specific energy and specific power with high cycling stability. Given the longer cycling stability of the device and considering the acceptable properties, the present work is a way forward for enhancing the circularity of the laboratory wastepaper towels.

Ultrasensitive Photodetectors Based on Strongly Interacted Layered-Perovskite Nanowires.

Metal-halide layered perovskites, self-assembled quantum wells with alternating insulating interlayer organic cations, and conductive perovskite layers boost the incorporation of multiple functionalities into a single-phase material. Optoelectronic performances in layered perovskites are more sensitive to crystallinity than their 3D counterparts due to the traps and insulating barriers introduced by interlayer cations. Here, we combine the capillary-bridge lithography method for the fabrication of single-crystalline nanowire arrays with strongly interacted layered perovskites for the enhancement of crystallinity and crystallographic orientation purity. Due to regulated nucleation and growth of layered perovskites in capillary bridges and the sulfur-sulfur interaction between interlayer cations, nanowires with pure (101) orientation are realized for underpinning insulating crystal interiors and photoconductive layer edges. Based on these nanowires, ultrasensitive photodetectors are reached with an ultralow dark current of below 10-12 A, an average responsivity of 7.3 × 103 A W-1, an average specific detectivity of 3.9 × 1015 Jones, and a 3 dB bandwidth of 10.3 kHz.

Tuning particle inertial separation in sinusoidal channels by embedding periodic obstacle microstructures.

Inertial microfluidics functions solely based on the fluid dynamics at relatively high flow speed. Thus, channel geometry is the critical design parameter that contributes to the performance of the device. Four basic channel geometries (i.e., straight, expansion-contraction, spiral and serpentine) have been proposed and extensively studied. To further enhance the performance, innovative channel design through combining two or more geometries is promising. This work explores embedding periodic concave and convex obstacle microstructures in sinusoidal channels and investigates their influence on particle inertial focusing and separation. The concave obstacles could significantly enhance the Dean flow and tune the flow range for particle inertial focusing and separation. Based on this finding, we propose a cascaded device by connecting two sinusoidal channels consecutively for rare cell separation. The concave obstacles are embedded in the second channel to adapt its operational flow rates and enable the functional operation of both channels. Polystyrene beads and breast cancer cells (T47D) spiking in the blood were respectively processed by the proposed device. The results indicate an outstanding separation performance, with 3 to 4 orders of magnitude enhancement in purity for samples with a primary cancer cells ratio of 0.01% and 0.001%, respectively. Embedding microstructures as obstacles brings more flexibility to the design of inertial microfluidic devices, offering a feasible new way to combine two or more serial processing units for high-performance separation.

Comparison of carbon molecular sieve and zeolite 5A for CO2 sequestration from CH4/CO2 mixture gas using vacuum pressure swing adsorption

The performance of carbon molecular sieves and zeolite 5A was compared in a four-bed vacuum pressure swing adsorption process. The purpose of the process is to sequester CO2 from a CH4/CO2 mixture gas, such as coal bed methane or landfill gas. This study investigated the effects of the design variables and operating variables on methane purity, recovery, and specific power through simulations of the process using the two adsorbents. The adopted design variables for the investigation are the packing bed length and the diameter of the adsorption bed, and the selected operating variables are the adsorption pressure and vacuum pressure. The simulation results show that zeolite 5A is better than carbon molecular sieve in terms of power, especially under low-pressure operating conditions with a vacuum pressure of 1,000 Pa. However, carbon molecular sieves are better in terms of purity enhancement when the vacuum pressure is higher than approximately 2,000 Pa.

Enhancement of polarization purity in square dielectric resonator antenna using coaxial feed with metal strip loading for point-to-point communication applications

In this paper, a simple technique to enhance the polarization purity in a square dielectric resonator antenna (SDRA) using metal strip loading on the probe feed is presented for point-to-point communication applications. Coaxial feed placed at the commonly used offset location adjacent to the DRA has been studied in this regard. Cross polarized (XP) fields scattered from the feed into the air are found to be one of the reasons behind the deterioration of polarization purity in SDRA. When a thin metal strip is loaded on the probe feed using liquid solder to control these XP fields, the measured result shows an XP isolation of 47 dB at the boresight, 42 dB and 29 dB at the angular region of ±30°in the E-plane and H-plane, respectively. The proposed technique helps to overcome many unavoidable fabrication errors associated with complex machining and drilling processes involved in contemporary DRA designs for XP suppression. The proposed SDRA design offering good XP isolation performance and simple fabrication technique is highly suitable for low cost and high precision applications.

Recent Advances in Microwave Assisted Multicomponent Reactions

AbstractMicrowave (MW) assisted multicomponent reactions (MCRs) provide facile and expeditious procedures for the synthesis of several diversely functionalised molecules. Significant enhancement in selectivity, purity and reproducibility is offered by this process. Shorter reaction times as well as higher product yield are attained efficiently using MW assisted MCRs. The present review focuses on the developments in this field covering literature from 2013–2019 and the topic is categorised based on the final products obtained.

Giant efficiency and color purity enhancement in multicolor inorganic perovskite light-emitting diodes via heating-assisted vacuum deposition

Inorganic perovskites (CsPbX3 (X = I, Br, Cl)) have broad prospection in the field of high-definition displaying due to its excellent optoelectronic characteristics. The vacuum deposition process possesses advantages and competitiveness in the industrialized production. However, the performance of light emitting diodes (LEDs) based on vacuum-deposited is incredibly low. Herein, we proposed a heating-assisted vacuum deposition (HAVD) method to construct inorganic perovskite LEDs (PeLEDs) with enhanced performance. The roughness and crystallinity of perovskite film were improved by regulating the heating treatment of substrates. And the perovskite film exhibited largely rise in luminescence, with decreasing defect density. Consequently, with the optimized temperature, the green PeLEDs exhibited 100-fold improvement of external quantum efficiency (EQE) with the luminance of up to 11 941 cd/m2, and the full width at half-maximum (FWHM) of the electroluminescence (EL) spectra was decreased from 25 to 17 nm. At the same time, the red and blue PeLEDs also exhibited obvious enhancement in EQE and luminance by HAVD method, and both the FWHM of EL spectra dropped below 20 nm, exhibiting excellent high color purity. HAVD strategy has a huge potential to be a new commonly used method for low-cost fabrication of displays and lighting.

Process parametric optimization toward augmentation of silica yield using Taguchi technique and artificial neural network approach

This study was attempted towards the retrieval of silica from rice husk ash to annihilate the local problems of disposal from the rice milling industries for enhancement of silica purity. Optimization of process factors using the Taguchi technique involved variation in sodium hydroxide concentration (NaOH), alkali impregnation volume per unit weight of the rice husk ash, and reaction time for designing the experimental matrix utilizing L16 orthogonal array at four different levels. The maximum silica extraction was 98.26% obtained with 4 N of NaOH, 20 ml/g of alkali volume, and treatment time 60 min. The identical experimental data set was also applied to an artificial neural network model (ANN) with the LM algorithm for predicting the feasibility of the extraction process. Both Taguchi and neural networks suggested a high coefficient of determination and a satisfactory correlation between experimental and predicted silica recovery values. The detailed characterization of the synthesized silica powder and residual rice husk ash was executed using field emission scanning electron microscopy (energy-dispersive spectroscopy), Fourier transform infrared spectroscopy, thermogravimetric, Brunauer Emmett Tellet surface area, and particle size analysis. The simultaneous reuse of residual ash and silicate was performed to ensure the best possible reclamation of silica and reusability of rice husk ash. The detailed cost estimation of the synthesized silica powder further suggested the effectiveness of the optimized process. Thus, a comprehensive approach for enhancement of the silica yield and purity by adopting Taguchi and ANN optimization proved to be useful in this study.

Investigations on the Extreme Frequency Shift of Phosphosilicate Random Fiber Laser

Random fiber lasers (RFLs), which employ random distributed feedback (RDFB) provided by the intrinsic Rayleigh scattering (RS) along the passive fiber, have gained wide attention in the last decade. A major advantage of Raman gain based RFL is wavelength flexibility, and the so-called cascaded Raman conversion can extend the operating wavelength considerably. However, frequently used silica fibers often need multiple Raman shifts to reach the final desired wavelength due to its peak frequency shift of ~13.2 THz. A good alternative is the phosphosilicate fiber which has a gain peak at ~39.8 THz. Nevertheless, the simultaneous existence of silica-related and phosphorus-related gain peaks in the phosphosilicate fiber intensifies the gain competition, further limiting the power scaling and the enhancement of spectral purity, even making it difficult to reach the desired wavelength. In this article, we experimentally explored the influences of the pump wavelength and bandwidth on the lasing performance of a phosphosilicate RFL, and measured the extreme frequency shift of the phosphorus-related Raman gain peak. Besides, by the aid of a modified power balance model, we qualitatively simulated the impacts of pump spectrum and boundary condition on the laser output. The simulation agrees well with the experimental results, and may also explain the parasitic lasing in the prior reports of phosphosilicate RFLs. As a result, the extreme frequency shift of phosphosilicate RFL is measured to be ~1 THz. And through optimizing the pump wavelength and pump bandwidth, 99.24% high spectral purity random lasing at 1237 nm with 33.1 W output power is obtained. This work may help to reveal the gain competition in phosphosilicate RFL and guide the future laser design.

Integrated purification of a nanobody using ammonium sulfate precipitation and Capto MMC

AbstractBACKGROUNDCurrently, nanobodies are undergoing intensive studies due to their characteristics of nanoscale size, high affinity and specificity, and deep tissue penetration. The development of novel and simplified methods to purify nanobodies is required because high purity and high recovery are the limiting factors for the downstream preparation of nanobodies.RESULTSIn this study, ammonium sulfate precipitation (ASP) and electropositive multimodal chromatography (Capto MMC) were integrated for tag‐free nanobody (2D5) purification. ASP was our first choice for protein purification because the process is simple, easy to operate, and has low cost. ASP achieved a 36% reduction in Escherichia coli host cell proteins (HCPs), a 99.1% reduction in E. coli host cell DNA, and an 85.1% reduction in endotoxins with a recovery of 81.7% and a purity enhancement from 6.2% to 73.9%. Capto MMC was seamlessly integrated for 2D5 purification. The recovery of this step was 83.0%. The entire two‐step purification platform yielded 2D5 with 397 ppm of HCPs, 198 ppb of DNA, 204 EU/mL of endotoxins, and total protein recovery of 67.8%. The purity of 2D5 was 97.5%. The purification method was also used to purify a nanobody against PD‐L1 (KPU) with 97.7% purity, &gt; 95.7% recovery, 223 ppm of HCPs, 634 ppb of DNA and 154 EU/mL of endotoxins.CONCLUSIONThe established method had no effect on the affinity of 2D5. A simple and efficient purification platform that integrates ASP and Capto MMC was established, providing a more promising alternative to the conventional affinity chromatography‐based nanobody purification strategy. © 2019 Society of Chemical Industry