Simple Procedure Research Articles

Synthesis of Schiff base polymer/black talc nanocomposites based on m-phenylendiamine with enhanced separation performance for lead adsorption

In this study, we have developed a facile in-situ hydrothermal oxidative polymerization method to synthesize poly N,N(1,3-phenylene)dimethanimine/KH550-black talc (PNPD/KH550-BT) nanocomposites for efficient removal of lead (II) (Pb2+) in wastewater. This method employed eco-friendly solvent, offered a simple and cost-effective preparation procedure and resulted in a nanocomposite complex that displayed exceptional resistance to dissolve in various organic solvents, simplifying the separation process. Through the hydrothermal oxidative polymerization process, polymerization was promoted to generate spherical flower-like structures, effectively improving the dispersion of polymers on black talc nanosheets. Substantial concentration of sturdy lead-complexing groups was created, including N–H, –CN, and –NH2, which heightened the attraction to Pb2+ ions and maximized the effective utilization of lead binding sites. Compared with KH550-BT and PNPD, the adsorption performance of PNPD/KH550-BT composites on Pb2+ was significantly enhanced, and the largest adsorption capacity of lead (II) on PNPD/KH550-BT nanocomposites reached 867.1 mg/g. Moreover, the prepared nanocomposites had satisfactory adsorption potential after undergoing 10 cycles, showing good stability during adsorption. This work not only provides a new strategy to control the microstructure of polymer-based composite adsorbent but also presents various promising functionalized nanocomposites based on different polymers and minerals for application in vast fields.

Zeolite Imidazolate Frameworks-8@SiO2-ZrO2 Crystal-Amorphous Hybrid Core-Shell Structure as a Building Block for Water Purification Membranes.

Metal-organic frameworks (MOFs) are emerging as promising materials for water purification membranes, owing to their uniform microporous structures and chemical functionalities. Here, we report a simple procedure for depositing MOF-based nanofiltration membranes on commercial TiO2 ceramic tubular supports, completely avoiding the use of dispersants or binders. Zeolite imidazolate frameworks-8 (ZIF-8) nanocrystals were synthesized in methanol at room temperature and subsequently coated with an amorphous SiO2-ZrO2 gel to generate a dispersion of ZIF-8@SiO2-ZrO2 core-shell nanoparticles. The amorphous SiO2-ZrO2 gel served as a binding agent for the ZIF-8 nanocrystals, thus forming a defect-free continuous membrane layer. After repeating the coating twice, the active layer had a thickness of 0.96 μm, presenting a rejection rate >90% for the total organic carbon in an aquaculture effluent and in a wastewater treatment plant, while reducing the concentration of trimethoprim, here used as a target pollutant. Moreover, the oxide gel provided the MOF-based active layer with good adhesion to the support and enhanced its hydrophilicity, resulting in a membrane with excellent mechanical stability and resistance to fouling during the crossflow filtration of the real wastewater samples. These results implied the high potential of the MOF-based nanocomposite membrane for effective treatment of actual wastewater streams.

Aqueous Extract of Dillenia indica Fruit (AEDI): A Sustainable Biocatalyst for the Synthesis of Pharmacologically Important Bis(indolyl)methanes

AbstractA highly effective green technique for the synthesis of bis(indolyl) methanes mediated by ‘Aqueous Extract of Dillenia indica’ (AEDI) is developed. The reaction involves a simple procedure at a moderate temperature of below 60 °C in air within a short reaction time of 30–60 minutes under conditions free from external promoters, acids, ligands/organic media using our natural water–extracted catalyst, affording moderate to high yield. This protocol offers a mild, effective, and highly economical alternative to the existing protocols and promotes a more environmentally friendly alternative for the protic and Lewis acids catalysts that are already in use.

Determination of erythromycin, clarithromycin and N-desmethyl-erythromycin A residues in pork, beef and lamb based on a simple and fast extraction procedure followed by ultrahigh-performance liquid chromatography with triple quadrupole/linear ion trap mass spectrometry

A modified quick, easy, cheap, effective, rugged and safe (QuEChERS) method was developed for the simultaneous determination of erythromycin (ERY), clarithromycin (CLA) and N-desmethyl-erythromycin A (N-D-ERY) in pork, beef and lamb via ultrahigh-performance liquid chromatography with triple quadrupole/linear ion trap mass spectrometry (UHPLC-QTRAP-MS/MS). The sample preprocessing and detection conditions were optimized, and the obtained parameters of all target compounds met the EU and FDA requirements. In the sample preprocessing procedure, acetonitrile-water (80:20, v/v) was used as an extractant, and a Cleanert MAS-Q cartridge was utilized and achieved good extraction recovery. The matrix-matched calibration curves showed good linearities, with determination coefficients of 0.9983–0.9999. The recoveries ranged from 88.96% to 101.76% with relative standard deviations (RSDs) ≤5.95%, and the intraday and interday RSDs ranged from 2.64% to 6.65% and 3.08–6.38%, respectively. The limits of detection and quantification for the pork, beef and lamb samples were 0.4 μg/kg and 2.0 μg/kg, respectively. The detection limits and detection capabilities were in the range of 2.15–215.16 μg/kg and 2.26–230.32 μg/kg, respectively. This method was successfully applied to the analysis of the pork, beef and lamb samples, demonstrating its applicability and suitability for the routine analysis of ERY, CLA and N-D-ERY residues in meat samples.

Exploring impact of student attitude, parental involvement, and teacher competence on mathematics performance in selected schools in Northern Ghana

The purpose of this study was to see how students’ attitudes towards mathematics influenced their academic achievement in the Savelugu Municipality in the Northern Region of Ghana. The study employed the pragmatic paradigm and quantitative methodology. A 41-item semi-structured questionnaire rated using 5-points Likert scale, and document reviews were used to collect data. A combination of purposive and simple random sampling procedures was used to select 35 junior high school (JHS) in the Savulugu Municipality, questionnaires were administered to 350 JHS students, however, 315 questionnaires were returned. Data obtained from questionnaire were analyzed using Pearson product moment correlation coefficient, t-test, means, standard deviation, and percentages. The results revealed that educational institutions should develop programs to help parents become more active in their children’s education. To influence students’ attitudes towards mathematics study, policymakers and the Ghanaian Educational Service should promote programs such as National Mathematics Day to raise students’ awareness of the importance of mathematics in their daily lives. The Ministry of Education and non-governmental organizations should endeavor to offer enough instructional resources and financial incentives to instructors to help them make teaching relevant in the classroom.

Synthesis, characterization, and investigation the catalytic potential of diammonium phosphate modified with bismuth for the one-pot synthesis of 3,4-dihydropyrimidin-2(1H)-ones through a three-component reaction: An in-depth evaluation using green metrics

A straightforward synthesis of a novel catalyst, bismuth phosphate (Bi(NO3)3/DAP), was achieved using a co-precipitation method. The resulting material underwent thorough characterization employing various techniques, including X-ray diffraction, FTIR, scanning electron microscopy (SEM), and EDX. We investigated the application of Bi(NO3)3/DAP as a catalyst in the 3,4-dihydropyrimidin-2(1H)-ones reaction between urea, ethyl acetoacetate, and various aldehydes. The results demonstrated that the catalyst exhibited excellent catalytic performance, leading to the production of products with impressive yields (89–97 %) in just 15 min in an ethanol medium. Additionally, the heterogeneity of the reaction was confirmed through a hot filtration test. Notably, this catalyst presents notable benefits, such as its easy recovery and ability to be reused for a minimum of five successive cycles, a simple work-up procedure, and the attainment of high product yields. A sustainability evaluation based on green metrics using the E-factor, atom economy (AE), reaction mass efficiency (RME), and optimum efficiency (OE) revealed that the use of a catalyst in the Biginelli reaction enhances environmental sustainability.

Design of efficient alterable bandwidth FIR filterbank for hearing aid system

The lifestyle of any person depends on his ability to hear his surrounding sounds or voices. This is because each of our sense organs works interrelated. Without an ability to proper hearing, he/she cannot respond to the other person leading to a very less or no communication to the society. Although he has a good talent and knowledge within, he cannot be able to communicate or express unless he has a good hearing ability. Also, he faces emotive problems caused by a reduction in self-confidence. So, a requirement of designing an efficient hearing aid is much necessary to resolve the hearing loss problem. In this paper, design of an efficient alterable ten band Finite Impulse Response filter bank for the hearing aid is achieved. Among the various windowing techniques available, Hamming window is preferred to design the FIR filter owing to its relatively sharp main lobe width and also the first few lobes have good attenuation. In this filterbank, variability in the subband bandwidths is achieved by simply altering each subband's bandwidth and center frequency. Unlike fixed filterbank, the proposed design provides the advantage of matching most of the audiograms of different hearing-impaired persons more accurately with simple procedure leading to low cost and low hardware complexity. Also using an FIR filter in the filterbank leads to highly stable design. Thus, a design of highly qualitative filterbank compared to fixed bandwidth designs with high audiogram matching and less matching error is implemented.

Role of nano-magnetized Citrus X sinensis (orange) peels for decontamination of pendimethalin from aqueous resources: a comparative study of untreated and carbonaceous orange peels with nano-magnetized peels

Abstract Biosorption is a low-cost, environment friendly wastewater treatment method that involves a simple procedure for the removal of pesticides and their residues from wastewater. In the present investigation, untreated Citrus X sinensis peels (U-CXSP), activated carbon Citrus X sinensis peels (AC-CXSP) and nano-magnetized Citrus X sinensis peels (NM-CXSP) adsorbents were applied for the uptake of pendimethalin (PDM) from aqueous resources. The laboratory-prepared adsorbents were characterized using SEM, EDX, FTIR, VSM and XRD. Biosorption studies were carried out by varying different parameters, i.e., adsorbents dosage (0.1–0.5 g), time of contact (10–70 min), initial concentration of PDM (5–200 ppm), pH and temperature. The results showed that the removal efficiency of U-CXSP was increased from 97 to 114 mg/g for AC-CXSP adsorbent and increased from 97 to 111 mg/g for NM-CXSP adsorbent. Kinetics data obtained from this study well fitted with pseudo-second-order kinetic model. Adsorption isotherms were studied and the adsorption data well fitted with Langmuir and Freundlich models. Order of the adsorption efficiency is observed as follows: AC-CXSP > NM-CXSP > U-CXSP.

Comparison of competitive and sandwich immunochromatographic analysis in the authentication of chicken in meat products

Cheap chicken meat is often used as an undeclared substitute in meat products. In this study, two formats of the immunochromatographic assay (ICA) of immunoglobulins of class Y (IgY) as a biomarker for chicken authentication were developed. In both competitive ICA (cICA) and sandwich ICA (sICA), gold nanoparticles (GNP) were conjugated with anti-species antibodies. A simple procedure of sample preparation, which took only 30 min, was proposed. Test systems demonstrated high sensitivity and rapidity: visual limits of detection of IgY and assay durations were 12/14 ng/mL and 10/15 min for cICA and sICA, respectively. The absence of cross-reactivity with the mammalian species confirmed the high specificity of the test systems. Good applicability of the assays was confirmed for the detection of chicken in raw meat mixtures: as low as 3% and 0.2% (w/w) of chicken could be revealed in beef and pork by cICA and sICA, respectively. The influence of heat processing of meat-based products on immune recognition and, consequently, the analytical performance of the test systems was revealed. It was shown that sICA is preferable for the detection of IgY even in thermally processed meat. The proposed ICAs can be recommended for rapid on-site control of meat products’ composition.

On the Exact Solution of a Scalar Differential Equation via a Simple Analytical Approach

The existence of the advance parameter in a scalar differential equation prevents the application of the well-known standard methods used for solving classical ordinary differential equations. A simple procedure is introduced in this paper to remove the advance parameter from a special kind of first-order scalar differential equation. The suggested approach transforms the given first-order scalar differential equation to an equivalent second-order ordinary differential equation (ODE) without the advance parameter. Using this method, we are able to construct the exact solution of both the transformed model and the given original model. The exact solution is obtained in a wave form with specified amplitude and phase. Furthermore, several special cases are investigated at certain values/relationships of the involved parameters. It is shown that the exact solution in the absence of the advance parameter reduces to the corresponding solution in the literature. In addition, it is declared that the current model enjoys various kinds of solutions, such as constant solutions, polynomial solutions, and periodic solutions under certain constraints of the included parameters.

Fabrication of superhydrophobic (CuO-SiO2) nanocomposite coating for oil/water separation

ABSTRACT The presence of oil-contaminated water due to oil spill disasters or improper industrial waste dumping is now a worldwide danger to both human health and the sustainability of the environment.The use of superhydrophobic materials has attracted considerable attention in the field of oil-water separation, owing to the increasing demand for effective and economical oil-water separation techniques.A new, easy, and inexpensive flame treatment method was used to make a nanocomposite (CuO-SiO2) in order to improve its hierarchical structure (micro-nano).The anodisation process produced copper oxide (CuO) nanostructures (NSs) on a copper mesh. Subsequently, the nanostructures were modified by dip coating with a solution of room-temperature vulcanised silicone rubber (RTV-SR).The coated mesh demonstrated remarkable characteristics of superhydrophobicity and superoleophilicity, with a water contact angle (WCA) of (160 ± 1 ° ) and an oil contact angle (OCA) of (0 ° ), as determined during the measurement of the surface’s wetability. The coated mesh surface was characterised using X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), and energy dispersive spectroscopy (EDS).The successful separation of kerosene-water and diesel oil-water mixtures is accomplished by using a coated mesh in a simple filtration procedure. Furthermore, it has the capability to separate oils with a high efficiency of (99.8%) for kerosene and (87%) for diesel oil. It also has flux values of (7352.9 L.m -2 .h -1 ) for kerosene and (6112.9 L/m 2 .h) for diesel.

Crystallization and defects regulation of efficient perovskite solar cells via surface induced secondary grain growth with formamidine iodine treatment

Trap–mediated non–radiative loss is a major efficiency and stability obstale for solution–processed perovskite solar cells (PSCs). To address this issue, defect passivation using organic molecules has been identified as an effective strategy due to the ionic nature of the perovskite lattice. Herein, Ostwald ripening by using formamidine iodine (FAI) is reported to inhibit the carrier trap induced recombination via promoting secondary grain growth at perovskite surface. Based on secondary grain growth with FAI treatment, the graded passivation was presented caused by FA+ and I- from FAI. Moreover, the findings from time resolved photoluminescence and space charge–limited current technology indicate enhancements in the crystal quality. Consequently, this approach yielded a remarkable power conversion efficiency (PCE) of 20.62% for the FAI modified MAPbI3 photovoltaics, with significantly improved open–circuit voltage ratio of 3.10%, short–circuit density ratio of 6.11%, fill factor ratio of 9.46% and PCE ratio of 19.06%. Moreover, the device show the excellent stability. This study introduces simple and reproducible procedures for fabricating PSCs, which can be readily extended to diverse optoelectronic device applications.

Spectrophotometric resolution for quantitative analysis of aspirin and rivaroxaban combination therapy in biological fluids using simple and eco-friendly procedure

Patients diagnosed with symptomatic peripheral artery disease (PAD) in the lower extremities have a higher likelihood of suffering from major vascular events. Recently, FDA has approved the combination therapy of aspirin (ASP) and rivaroxaban (ROX) to reduce acute limb ischemia and other comorbidities in (PAD) patients. Zero order and ratio absorption spectra were employed in three simple and accurate spectrophotometric techniques (dual wavelength (DW), ratio difference (RD) and derivative ratio (1DD) for concurrent detection and quantification of ASP and ROX in their pure forms, lab synthetic mixtures and in biological fluid. Our approach involves careful parameter optimization, including solvent selection, sample volumes, and instrumental settings, to reduce the analysis environmental impact. The acquired recovery percentages of accuracy were within 98–102% for pure active pharmaceutical ingredients and 90–110% for pharmaceutical formulations and biological determinations. A comprehensive assessment was done to compare the three methods regarding their ease of use, linearity, sensitivity, conditions, and limitations. The specificity of the proposed methods was evaluated by analyzing the lab synthetic mixtures. The suggested spectrophotometric methods were validated in compliance with ICH guidelines to confirm the validity claims. Also, statistical analysis was done to compare the outcomes obtained from the suggested methods with those obtained from the official ones and they agreed with null hypothesis regarding accuracy and precision. Furthermore, a comprehensive assessment of the environmental sustainability of the developed method was carried out using the Analytical Greenness Calculator, AGREE algorithm. The selected drugs can be efficiently, safely and economically analyzed by the suggested methods in pharmaceutical and biological matrices with no pretreatment or preliminary separation steps and thereby increasing their greenness level.

A systematic review of the operative techniques for treating cubitus varus deformity in children.

A systematic review of the operative techniques for treating cubitus varus deformity in children was performed using research databases including PubMed and Embase. Outcome measurements included mean angular correction of the humerus-elbow-wrist angle, complications, revisions and outcome scores. A total of 45 papers and 911 patients were included. Lateral closing wedge osteotomy (LCWO) (427 patients) was the most common procedure and 5.56% of these patients experienced lateral condylar prominence. This technique had the highest revision rate at 3%. The step-cut osteotomy (111 patients) yielded zero postoperative infections or loss of motion. Distraction osteogenesis (92 patients) was the least common technique. Superficial pin tract infections occurred in 18% of patients and 88.04% of patients reported excellent results, the highest of any technique in this study. The infection rate of dome osteotomy (151 patients) was 9.45% and 4.72% of patients experienced loss of motion. 3D osteotomy (130 patients) had no infections, 87.78% of patients reported excellent outcomes, and 2.22% of patients reported poor outcomes, the lowest of all techniques. For unidimensional correction, LCWO provides a technically simple procedure and reasonable outcomes. Step-cut osteotomy has less lateral condylar prominence but is more complicated than LCWO. Distraction osteogenesis is a minimally invasive alternative to LCWO and step-cut osteotomy, but it has more superficial infections and can be bothersome to patients. For a multidimensional correction, 3D osteotomy is superior to dome osteotomy due to its lower infection rate and higher rate of functionally excellent outcomes.

Exploring Heterotropones and Examining Their Propensity to Undergo [4 + 2] Cycloadditions.

An efficient strategy to obtain a broad array of chiral and achiral heterotropones and their corresponding [4 + 2] cycloadducts is disclosed. This strategy enables access to unique heterotropones and intricate bicyclic structures in high yields and diastereoselectivities through a simple procedure and from easily accessible starting materials.

Facile Preparation of TICT@MOF Solids with Unprecedented PL Quantum Yields

AbstractLuminescent solids exhibit unique optical and electronic properties, and it is important to develop a simple experimental procedure to reduce the mass of weakly emissive hybrid inorganic–organic solids. The instant mixing of (1‐cyano‐2‐[α‐terthiophen‐2‐yl]‐vinyl)carboxylic acid (3TCC) and a metal–organic framework (MOF‐177; ZnO4(BTB)2; BTB = 1,3,5‐benzenetribenzoate) in an organic solvent, followed by evaporation of the solvent, produces solids with distinct photoluminescence (PL) properties, turning over the PL quantum yields (PLQY) of the generated 3TCC@MOF‐177 solids by 2‐ to 40‐fold compared to the 3TCC solution is demonstrated. The new solids are characterized by various methods and optical measurements. Contrarily to the trend in the photophysical results of 3TCC solutions, the anisotropic rotational times of 3TCC@MOF‐177 solids inversely correlate with the corresponding PLQY values depending on the protic solvent used in the initial preparation step in the following order: methanol>ethanol>butanol. This behavior is attributed to the complexation of 3TCC dye with metal clusters within the pores of MOF‐177 and hydrogen bonding of the CN group in the dye with the OH group in the linkers. These factors interplay with the kinetics of dye twisting. These observations reflect the potential of new solid luminescent architectures with remarkable PLQY that can be easily manufactured.

Special moment frame connections with shear-yielding haunches

Steel special moment frame connections with shear-yielding haunches can be used for seismic retrofit and for new construction. In this study, shear-yielding haunch connections were investigated through experimental testing and finite element analysis. Three specimens were tested, each with a W1000 × 591 beam and W1000 × 554 column. The cyclically loaded specimens completed cycles at 0.04 rad prior to low-cycle fatigue of the haunch plates. The monotonically loaded specimen reached 0.064 rad drift. The experimental specimens had 10 to 15% post-yield stiffness, and the fuses reached the ultimate material strength prior to tearing. M-factors for the connection were determined to be 4.7 for life safety and 6.3 for collapse prevention. Finite element models were used to quantify force transfer through the connection and to investigate the retrofit-specific detail. The experiments and finite element models confirmed that a relatively simple design procedure produced acceptable designs.

Recent development and engineering practices of space grid structures in China

Space grid structures are widely used in the field of structural engineering due to their good mechanical properties and simple construction procedures. This paper reviews the development of space grid structures and mainly introduces the development of space grid structures in China in recent years. Some typical applications of space grid structures are introduced and the technical developments are summarized. It shows that China not only has a large number of engineering applications of space grid structures, but also a rapid development of related technologies. Finally, some prospects for space grid structures are discussed.

On k-wave solutions of quasilinear systems of partial differential equations

In this paper, we establish a relation between two seemingly unrelated concepts for solving first-order hyperbolic quasilinear systems of partial differential equations in many dimensions. These concepts are based on a variant of the conditional symmetry method and on the generalized method of characteristics. We present the outline of recent results on multiple Riemann wave solutions of these systems. An auxiliary result concerning a modification of the Frobenius theorem for integration is used. We apply this result in order to show that the conditional symmetry method can deliver larger classes of multiple Riemann wave solutions, through a simpler procedure, than the one obtained from the generalized method of characteristics. We demonstrate that solutions can be interpreted physically as a superposition of k single waves. These theoretical considerations are illustrated by examples of hydrodynamic-type systems in (n+1) dimensions.

Synthesis of geopolymer composites using bauxite residue-based spheres as aggregate: Novel and eco-friendly strategy to produce lightweight building materials

In this study, and for the first time, highly porous red mud-based geopolymer spheres were produced, through a very simple and scalable procedure, and used as lightweight aggregate in the synthesis of geopolymer composites. To further demonstrate the potential of this unexplored route, a comparison with composites containing expanded perlite and expanded vermiculite was also performed. The sample produced with 85 vol% of spheres showed the lowest geometric density (0.84 g/cm3) amongst the studied composites, coupled with a suitable compressive strength (1.0 MPa), low thermal conductivity (175 mW/m K), and excellent thermal stability after exposure to 1000 °C for 2h. The much lower production temperature (80 °C), compared with the commercial expanded aggregates (above 650 °C), and the reuse of significant amounts of bauxite residue (strategy aligned with the circular economy) enables the production of eco-friendly lightweight aggregates for the building sector.