Physicochemical Method Research Articles

Lignocellulosic Analysis of Corncob Biomass by Using Non-Thermal Pulsed Electric Field-NaOH Pretreatment

In recent years, the second-generation bioethanol and advanced bio-based material production from biomass are focused on the pretreatment process by separating cellulose components from other components such as lignin and hemicellulose. Therefore, a physicochemical pretreatment method is needed by applying a non-thermal pulsed electric field (PEF) and alkali methods to increase the cellulose availabilities with a short process and low energy input. The aim of this study was to analyze the lignocellulose content of corncob biomass by using non-thermal pulsed electric fields (PEF) and NaOH pretreatment. The pretreatment factors used were the electric field strength of PEF and the pretreatment time. Analysis of the structure and elements of the lignocellulose based on the characteristics of the gravimetric method and SEM-EDX for untreated and treated samples. The results showed that pretreatment of corncobs biomass by using PEF optimally at an electric field strength of 9 kV/cm and pretreatment time of 60 seconds that was increasing cellulose of 40.59% when compared with the control and also decreasing the hemicellulose and lignin content of 12.9% and 2.02%, respectively. Under these conditions, the energy per pulse and specific input energy of PEF required 0.0205 J and 8.72 kJ/L, respectively. The microstructure analysis by using SEM-EDX showed significantly visual differences and was an increase in the percentage of C and O atoms between untreated and treated corncob biomass. Furthermore, the corncob biomass treated by using non-thermal PEF and alkali can become effective and efficient for the next process into cellulose-derived products.Keywords: corncob biomass; pulsed electric field; NaOH; pretreatment; cellulose

Feasibility of the use of different types of enzymatically treated cellulosic fibres for polylactic acid (PLA) recycling

In the present study, the potential use of cellulosic microfibers (CMFs) extracted from hemp fiber (HF) and pulp and paper solid waste (mixed sludge (MS), deinked sludge (DS)) as a reinforcing agent in novel bio composite materials produced from recycled Polylactic acid (rPLA) was investigated. CMFs were extracted and treated using physicochemical method followed by enzymatic treatment with laccase and cellulase. The effects of CMFs concentrations (1.5, 3 and 6% w/w) and fiber size (75 μm–1.7 mm) on the mechanical properties (impact and tensile) and biodegradability of the biocomposite samples were investigated. A modified interfacial adhesion between rPLA matrix and the three fibers used, was clearly observed through mechanical tests due to alkali and enzymatic treatments. The use of different types of enzymatically treated cellulosic fibers for polylactic acid (PLA) recycling was assessed by Scaning electron microscopy (SEM), X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR). The combined physicochemical and enzymatic treatments led to a considerable size reduction of the cellulosic fibers (HF, MS and DS) resulting in the enhanced interfacial adhesion between rPLA matrix and fibers. The biocomposite obtained with rPLA with HF gave the most favorable values for Young’s modulus (324.53 ± 3.10 MPa, p-value 0.03), impact strength (27.61 ± 2.94 kJ/m2, p-value 0.01) and biodegradation rate (1.97%).

Multiphase materials based on the Fe73.9Si15.5Cu1Nb3B6.6 alloy obtained by dry and wet high-energy ball milling processes

Novel hybrid materials based on the soft nanocrystalline Fe73.9Si15.5Cu1Nb3B6.6 alloy are designed in this work with the purpose of reducing its particle size and developing different compositional, structural, and magnetic properties depending on the high-energy ball milling time and route employed. Innovative processes combining mixer, vibratory and planetary motions at the same time are carried out under a dry and a wet route, obtaining reduced sub-micron particle size distributions after 2 h of milling. The established approach takes advantage of the nature of amorphous materials to promote the formation of different hybrid compounds and it is supported by the high virulence of the milling process performed at 2000 rpm. On the one hand, the results obtained by the dry route show a structural and magnetic evolution dominated by the presence of ferromagnetic α-Fe3Si nanocrystals. On the other hand, the wet approach that is supported by glycerol evidences the destruction of the α-Fe3Si with the milling time in favor of the non-magnetic β-FeSi2 phase, obtaining a new functionality for the Fe73.9Si15.5Cu1Nb3B6.6 alloy. Their properties as soft magnetic alloys are evaluated and compared depending on the followed route, opening up a new physicochemical method in the development of multiphase compounds with potential applications. With this work, a controlled formation of different hybrid compounds is achieved, revealing an effective mechanism to introduce functional materials with different properties embedded in an amorphous ferromagnetic matrix.

Physicochemical Computer Simulation of Hydrogeochemical, Ecological, and Hydrothermal Processes in the Earth’s Crust

The paper briefly describes some of the problems solved at the Institute of Geochemistry and Analytical Chemistry, Russian Academy of Sciences, to illustrate the possibilities and limitations of the promoted physicochemical computer simulation method. The computer simulation results on the formation of hydrocarbons in the Earth’s crust, acid drainage estimates, and other results of the method, obtained by researchers of the Institute of Geology of Ore Deposits, Petrography, Mineralogy, and Geochemistry, Russian Academy of Sciences, and colleagues of Tomsk Scientific Polytechnic University, are reported in separate papers.

Trapping synthetic dye molecules using modified lemon grass adsorbent

Physicochemical method was used to prepare lemongrass leaf activated carbon (LLAC) for removal of Remazol brilliant violet 5 R (RBV5R) dye from aqueous solutions. The surface area, mesopore surface area, total pore volume and average pore diameter of the LLAC are 836.04 m2/g, 598.6 04 m2/g, 0.472 04 cm3/g and 3.62 nm, respectively. The surface functional groups of LLAC before adsorption showed the existence of C–H, O–H, C-O, C = O, C = C, CH3, N–O and C–N; they are significantly altered after adsorption. The equilibrium data were fitted into Freundlich, Langmuir, Dubinin Radushkevich, Temkin, Koble Corrigan, Vieth Sladek, Radke Prausnitz and Brouers Sotolongo isotherm models. The Koble Corrigan and Freundlich models gave the best fit judging from the correlation coefficient (R2). The monolayer adsorption capacities (qm) obtained for Langmuir and Koble Corrigan isotherm models are 125 and 342.9 mg/g respectively. Kinetic data were fitted using pseudo-first order, pseudo-second order, intraparticle diffusion, Elovich, Boyd and Avrami models respectively. Thermodynamic parameters (ΔS0, ΔH0and ΔG0) were estimated. The mean adsorption energy Ea was 2.811 kJ/mol signifying that the adsorption is physically controlled. This study revealed that lemongrass leaf is effective in removing RBV5R dye from aqueous systems.

Comparability of Raman Spectroscopic Configurations: A Large Scale Cross-Laboratory Study.

The variable configuration of Raman spectroscopic platforms is one of the major obstacles in establishing Raman spectroscopy as a valuable physicochemical method within real-world scenarios such as clinical diagnostics. For such real world applications like diagnostic classification, the models should ideally be usable to predict data from different setups. Whether it is done by training a rugged model with data from many setups or by a primary-replica strategy where models are developed on a 'primary' setup and the test data are generated on 'replicate' setups, this is only possible if the Raman spectra from different setups are consistent, reproducible, and comparable. However, Raman spectra can be highly sensitive to the measurement conditions, and they change from setup to setup even if the same samples are measured. Although increasingly recognized as an issue, the dependence of the Raman spectra on the instrumental configuration is far from being fully understood and great effort is needed to address the resulting spectral variations and to correct for them. To make the severity of the situation clear, we present a round robin experiment investigating the comparability of 35 Raman spectroscopic devices with different configurations in 15 institutes within seven European countries from the COST (European Cooperation in Science and Technology) action Raman4clinics. The experiment was developed in a fashion that allows various instrumental configurations ranging from highly confocal setups to fibre-optic based systems with different excitation wavelengths. We illustrate the spectral variations caused by the instrumental configurations from the perspectives of peak shifts, intensity variations, peak widths, and noise levels. We conclude this contribution with recommendations that may help to improve the inter-laboratory studies.

Efficient preparation of ultrafine powder from waste cellulose by physicochemical method

Consumer waste of cotton cellulose is receiving increasing attention. In this study, in order to recycle waste cotton cellulose fibre into ultrafine powder efficiently, a compact process containing sulfuric acid treatment and stone milling was examined. Scanning electronic microscopy (SEM) and atomic force microscope (AFM) were used to study the morphology of the original cellulose fibre, acid modified fibre and milled cellulose powder. The particle size, crystallinity and strength loss were also explored. The results illustrated that the fibre strength can be largely reduced by acid treatment and high temperature and the crystallinity of the fibre decreased after stone milling. Ultimately, the production efficiency and the output of the micron dry cellulose powder were greatly improved. About 1 kg dry ultrafine powder with particle size around 40 μm was achieved in 1.5 h by stone milling in laboratory. This method shows a great potential for industrial application in the future.

Authentication and Quality Assessment of Meat Products by Fourier-Transform Infrared (FTIR) Spectroscopy

These days, food safety is getting more attention than in the recent past due to consumer awareness, regulations, and industrial competition to offer best quality products. Meat and meat products are very valuable but highly perishable. There is a need for reliable assessment techniques to ensure the safety and quality of these products throughout their shelf life. Classical analytical methods have been replaced with alternative, rapid, simple, and noninvasive methods to enhance productivity and profitability in the meat supply chain. Fourier-transform infrared (FTIR) spectroscopy has become a valuable analytical technique for structural or functional studies related to foods as a rapid, nondestructive, cost-efficient, and sensitive physicochemical fingerprinting method. This technique is readily applicable for routine quality control or industrial applications with a high degree of confidence. FTIR spectroscopy coupled with chemometrics has drawn attention to quality control, safety assessment, and authentication purposes in the meat and meat products domain. This review covers fundamental knowledge on FTIR spectroscopy coupled with chemometric techniques, as well as major applications of this robust method in meat science and technology for adulteration detection, monitoring biochemical and microbiological spoilage and shelf life, determining changes in chemical components such as proteins and lipids.

Sustainable approach to decolourize methyl orange dye from aqueous solution using novel bacterial strain and its metabolites characterization

The present report deals with the identification of new bacteria for the degradation of sulphonated azo dye such as methyl orange because this type of dye is difficult to degrade by the physico-chemical method. Hence, an eco-friendly and efficient technique like biological method was studied to degrade methyl orange. Initially, three strains were isolated from the flasks containing media amended with textile wastewater using the serial dilution process. Out of three strains, micrococcus yunnanensis exhibited a higher decolourization efficacy in 100 mg L−1, and hence, this strain was chosen for further optimization studies and metabolites identification. This is the first report to study the micrococcus species in methyl orange degradation according to our knowledge. The optimum parameters for the decolourization of methyl orange were found to be pH 7, temperature at 30 °C and dye concentration at 100 mg L−1. The carbon source and nitrogen source suited well for the decolourization were observed as 1% glucose and 1% peptone. The metabolites obtained after degradation of methyl orange were analysed using FT-IR and GC–MS analysis. The final product obtained from the degraded sample was found to be N, N-Diethyl-N’-methyl-1,3-propane diamine.

Rapid In-Process Monitoring of Lentiviral Vector Particles by High-Performance Liquid Chromatography

Lentiviral vectors (LVs) are a popular gene delivery tool in cell and gene therapy and they are a primary tool for ex vivo transduction of T cells for expression of chimeric antigen receptor (CAR) in CAR-T cell therapies. Extensive process and product characterization are required in manufacturing virus-based gene vectors to better control batch-to-batch variability. However, it has been an ongoing challenge to make quantitative assessments of LV product because current analytical tools often are low throughput and lack robustness and standardization is still required. This paper presents a high-throughput and robust physico-chemical characterization method that directly assesses total LV particles. With simple sample preparation and fast elution time (6.24 min) of the LV peak in 440 mM NaCl (in 20 mM Tris-HCl [pH 7.5]), this ion exchange high-performance liquid chromatography (IEX-HPLC) method is ideal for routine in-process monitoring to facilitate the development of scalable and robust LV manufacturing processes. Furthermore, this HPLC method is suitable for the analysis of all in-process samples, from crude samples such as LV supernatants to final purified products. The linearity range of the standard curve is 3.13 × 108 to 1.0 × 1010 total particles/mL, and both the intra- and inter-assay variabilities are less than 5%.

MALDI MASS SPECTROMETRY - IN THE ASSESSMENT OF HUMAN MICROBIOTA. CURRENT STATE AND PERSPECTIVES

Mass spectrometry is a modern physicochemical method of analysis that allows for a qualitative and quantitative analysis of the composition of a substancebased on the preliminary ionization of its constituent atoms or molecules. One of the new methods of ionization, thanks to which the mass spectrometric study of macromolecules has become widespread, is matrix-activated laser desorption / ionization (MALDI), which is a pulsed laser irradiation of the substance under study mixed with a matrix.Тhe article presents modern data on the use of the MALDI mass- spectrometry method for conducting genus and species-specific identification of microorganisms in the practice of diagnostic laboratories. The advantages of MALDI-TOF identification in comparison with other methods of microbiota research are considered.The place of mass spectrometry in the system of laboratory diagnostics of various pathogens is indicated.

Methods for determining the botanical origin of honey

The demand for monofloral, original, and special (functional) kinds of honey, or those with geographical indication, is forecast. At the same time, there is a need to improve the methods for determining the botanical and geographical origin of honey. The purpose of the research was to select and apply a variety of techniques for identifying the botanical origin of honey for its correspondence to acacia species. Samples of honey from the Kyiv, Odesa, and Dnipro regions extracted in the spring and summer period were used in the research. Organoleptic, physicochemical, NMR spectrometry, and advanced melissopalynology methods were applied. The tests were carried out at the laboratories of the Department of Certification and Standardization of Agricultural Products, NULES, Ukraine; the Ukrainian Laboratory of Quality and Safety of Agricultural Products; and the Bruker BioSpin GmbH company (Germany). According to the research results, the requirements for acacia honey were met by the organoleptic method for samples B1 and B2; by the physicochemical method for A0 and A2; by NMR spectroscopy for not a single sample, all being assessed as polyfloral; and by pollen analysis for B1 and B2. The conducted studies confirm the need for a comprehensive approach to the identification of the botanical origin of honey for its conformity to acacia species. There is a need to review the physicochemical indicators for the compliance of honey with the acacia species obtained in Ukraine. After all, even the modern NMR spectrometry technique indicated that the specially fabricated sample that did not contain acacia pollen grains was acacia honey. Identification of the botanical origin of monofloral honey, in particular acacia, should be carried out in the following sequence: pollen analysis (by dominant pollen grains), safety (presence of antibiotics, pesticides), physicochemical parameters according to international requirements, organoleptic parameters.

Destroying antimicrobial resistant bacteria (AMR) and difficult, opportunistic pathogen using cavitation and natural oils/plant extract

The present study reports, for the first time, a new and techno-economic strategy for effective removal of antimicrobial resistant bacteria (AMR) and difficult, opportunistic pathogen using cavitation and natural oils/plant extract. A hybrid methodology using natural oils of known health benefits has been discussed in combination with conventional physico-chemical method of hydrodynamic cavitation that not only provides efficient and effective water disinfection, but also eliminates harmful effects of conventional methods such as formation of disinfection by-products apart from reducing cost of treatment. A proof-of concept is demonstrated by achieving exceptionally high rates for practically complete removal of antimicrobial resistant (AMR) and relatively less researched, gram-negative opportunistic pathogen, Pseudomonas aeruginosa and gram-positive methicillin resistant, Staphylococcus aureus using a natural oil-Peppermint oil and two different cavitating reactors employing vortex flow (vortex diode) and linear flow (orifice) for hydrodynamic cavitation. >99% disinfection could be obtained, typically in less than 10 min, using vortex diode with operating pressure drop of 1 bar and low dose of 0.1% peppermint oil as an additive, depicting very high rates of disinfection. The rate of disinfection can be further increased by using simple aeration which can result in significant lowering of oil dose. The conventional device, orifice requires relatively higher pressure drop of 2 bar and comparatively more time (~20 min) for disinfection. The cost of the disinfection was also found to be significantly lower compared to most conventional processes indicating techno-economic feasibility in employing the developed hybrid method of disinfection for effectively eliminating bacteria including AMR bacteria from water. The developed approach not only highlights importance of going back to nature for not just conventional water disinfection, but also for eliminating hazardous AMR bacteria and may also find utility in many other applications for the removal of antimicrobial bacteria.

SERVICE BEHAVIOUR OF THE SELF-STRESSED MEMBERS REINFORCED WITH FRP BARS

Fiber reinforced polymer (FRP) bars, as a structural reinforcement, are characterized by the number of advantages, such as: high strength-to-density ratio; absence of corrosion; resistance to the negative influence of the different aggressive mediums. Nevertheless, a wide practical application of such a bars finds an embarrassment because of the law modulus of elasticity (it varies from 30 GPa to 60 GPa), that leads to the development of the excessive crack opening as well as deflections under the loading. To enhance structural performance of the FRP reinforced concrete members, pretensioning of FRP bars can be considered as a good option. Opposite to the concrete members mechanical pretensioning, physico-chemical method of bars pretensioning based on the self-stressing concrete utilizing is considered. Influence of the controlled initial stress-strain state obtained during early age concrete expansion on the mechanical resistance of the self-stressed concrete members reinforced with both steel and FRP bars was studied.

Bacterial eutrophic index for potential water quality evaluation of a freshwater ecosystem.

Water quality evaluation of freshwater ecosystems has been widely reported based on the physical and chemical parameters of water (e.g., Carlson's trophic state index (TSI)), while the aquatic microorganisms are actually a more intuitive way to reflect the eutrophic levels. This article was based on 27 global freshwater ecosystems including freshwater rivers, lakes, and reservoirs. Bacterial eutrophic index (BEI) was determined as the function of temperature and abundances of Cyanobacteria and Actinobacteria. BEI and TSI values of the freshwater ecosystems were determined and the correlation analysis of TSI and BEI indicated their positive correlation (ρ = 0.452, p < 0.01). Furthermore, an eutrophication classification based on BEI was proposed. It turned out that BEI was a possible feasible method for water quality evaluation. The aquatic microorganism-based method such as BEI should be considered for water quality evaluation of a freshwater ecosystem. Complicated models combined with physicochemical (e.g., TSI) and microbial (e.g., BEI) method are recommended for water quality evaluation of a freshwater ecosystem in future.

ВПЛИВ МЕТОДІВ ОТРИМАННЯ ПОЛІМЕРНИХ КОМПОЗИЦІЙ НА ОСНОВІ ТЕРМОСТІЙКИХ ПОЛІМЕРІВ НА ЯКІСТЬ СУМІЩЕННЯ ЇХ ВИХІДНИХ КОМПОНЕНТІВ

Investigation influence of methods obtaining polymer compositions based on thermostable polymers (aromatic polyamide, fluoropolymer and phenoplast) and dispersed silica on quality of their compound. It had been investigated quality of compound of initial components of polymer compositions based on thermostable polymers according to methods of obtaining it. This parameter had been estimate by uniform distributions of fillers in polymer compositions with help thermal method and microscopy. Investigation data’s had been process with help of methods of mathematical statistics. They are represented in the form of graphical and mathematical dependencies. It had been founded optimal time of mixing initial components of polymer compositions made by mechanical methods of compounding. It had been established that mixing time depend on concentration of dispersed filler in polymers. Based of result of investigations had been obtained mathematical dependences, that describe influence of concentration of initial components in polymer compositions on their mixing time. It had been founded quality of distribution of initial component of compositions made by physicochemical (in situ) method. It had been established influence of concentration of initial components in polymer compositions on quality of their distribution. It had been established regularity of dependence of methods of obtaining polymer composition based on thermostable polymers on quality of compound their initial components. It had been founded optimal technological parameters of compound the initial components of thermostable polymer compositions. And it had been founded optimal methods of their obtaining.

Identification of structural fingerprints for ABCG2 inhibition by using Monte Carlo optimization, Bayesian classification, and structural and physicochemical interpretation (SPCI) analysis

ABSTRACT The human breast cancer resistance protein (BCRP), one of the members of the large ATP binding cassette (ABC) transporter superfamily, is crucial for resistance against chemotherapeutic agents. Currently, it has been emerged as one of the best biological targets for the designing of small molecule drugs capable of eliminating multidrug resistance in breast cancer. In order to gain insights into the relationship between the molecular structure of compounds and the ABCG2 inhibition, a multi-QSAR approach using different methods was performed on a dataset of 294 ABCG2 inhibitors with diverse scaffolds. The best models obtained by different chemometric methods have the following statistical characteristics: Monte Carlo Optimization-based QSAR (sensitivity = 0.905, specificity = 0.6255, accuracy = 0.756, and MCC = 0.545), Bayesian classification model (sensitivity = 0.735, specificity = 0.775, and concordance = 0.757); structural and physicochemical interpretation analysis-random forest method (balance accuracy = 0.750, sensitivity = 0.810, and specificity = 0.700). Additionally, structural fingerprints modulating the ABCG2 inhibitory properties were identified from the best models of each method and also validated with each other. The current modelling study is an attempt to get a deep insight into the different important structural fingerprints modulating ABCG2 inhibition.

Assorted Interactions Prevalent in Uracil and Aqueous Gallic Acid Solution Explored by Physicochemical Contrivance

The solute-cosolute interaction of uracil by gallic acid has been studied through physicochemical investigation in aqueous environment. Here, we have carried out the density (ρ) and viscosity (η) measurements of uracil in w1= 0.001, 0.002 and 0.003 mass fraction of aqueous gallic acid binary mixtures at T= 298.15 K, 303.15 K and 308.15 K at pressure 1.013 bar. Some important parameters have been derived from the above physicochemical method, namely, limiting apparent molar volume (<i>φ_V</i>⁰) and viscosity <i>B</i>-coefficients using extended Masson equation and Jones-Dole equation respectively. The refractive index (<i>n_D</i>) has been done on the same system at T=298.15 K. Lorentz-Lorenz equation has used to evaluate molar refractive index (R_M) and limiting molar index (R_M⁰). The NMR study used to measure the plausible selective site of solute-cosolute interaction.<div><br></div>

Environmental monitoring of the reclaimed sites of JSC “EVRAZ ZSMK”sludge dump

For conservation of technologically disturbed lands, various methods of reclamation are used to prevent their negative impact on the environment. At the same time, technological methods are used, including changing the technology of waste storage, changing the state of storaged products using briquetting and granulation, creating mechanical barriers that prevent the spread of dust or continuous coating with non-dusting material, and the physicochemical method – creation of a protective layer using foam or hydro-dusting in order to stabilize a dusty surface. The most environmentally effective is the biological method – creation of a protective vegetation cover. This method is of particular relevance due to the phytotoxicity of the technogenic substrate for sludge dumps and the difficulties of creating a stable vegetation cover. Taking into account the industrial and environmental characteristics of the waste in sludge dumps of JSC “EVRAZ ZSMK”, an assessment of the physiological state was carried out as part of environmental monitoring and the chemical composition of plants growing in the reclaimed areas of this technogenic object was analyzed. A comprehensive assessment of the environmental safety of the use of sewage sludge from urban wastewater treatment plants on the substrate of the sludge storage facility as the main soil improver is given.

Effect of Flow Rate on Electrochemical Oxidation of Landfill Leachate Using DSA and BDD Anode

The leachate produced in municipal mixed waste landfill contains mostly organic pollutants in various forms. Biological treatment that popularly applied for the treatment only capable of removing biodegradable portion of the organics whilst the recalcitrant parts will leave the system untreated. Therefore, a pretreatment prior to biological process to increase biodegradability of leachate is essential. The physicochemical method such as electrochemical oxidation is an appropriate pretreatment alternative because it has high efficiency in degrading such pollutants. The purpose of this study was to examine the effect of flow rate (1.5 and 5 mL s−1) and anodes (boron-doped diamond (BDD) and dimensionally stable anode (DSA)) on the efficiency of electrochemical oxidation process to degrade leachate. The parameters analyzed were COD, BOD, ratio of BOD5/COD (biodegradability index, BI), TDS and pH. The results showed that the increase in BI when BDD and DSA used were 0.386 and 0.179, respectively. The best COD removal was achieved by BDD and DSA at current density of 30 mA cm−2 with the flow rate of 5 mL s−1. BDD could remove 83 % COD (1.56 g) while DSA 68 % (1.08 g) with specific energy consumption of 0.00268 kWh g−1 and 0.00186 kWh g−1, respectively.