Biodiesel Production from Alkali-Catalyzed Transesterification of Tamarindus indica Seed Oil and Optimization of Process Conditions

Biodiesel is considered a sustainable alternative to petro-diesel owing to several favorable characteristics. However, higher production costs, primarily due to the use of costly edible oils as raw materials, are a chief impediment to its pecuniary feasibility. Exploring non-edible oils as raw material for biodiesel is an attractive strategy that would address the economic constraints associated with biodiesel production. This research aims to optimize the reaction conditions for the production of biodiesel through an alkali-catalyzed transesterification of Tamarindus indica seed oil. The Taguchi method was applied to optimize performance parameters such as alcohol-to-oil molar ratio, catalyst amount, and reaction time. The fatty acid content of both oil and biodiesel was determined using gas chromatography. The optimized conditions of alcohol-to-oil molar ratio (6:1), catalyst (1.5% w/w), and reaction time 1 h afforded biodiesel with 93.5% yield. The most considerable contribution came from the molar ratio of alcohol to oil (75.9%) followed by the amount of catalyst (20.7%). In another case, alcohol to oil molar ratio (9:1), catalyst (1.5% w/w) and reaction time 1.5 h afforded biodiesel 82.5% yield. The fuel properties of Tamarindus indica methyl esters produced under ideal conditions were within ASTM D6751 biodiesel specified limits. Findings of the study indicate that Tamarindus indica may be chosen as a prospective and viable option for large-scale production of biodiesel, making it a substitute for petro-diesel.     

In Vitro and In Vivo Anti-Arthritic Potential of Caralluma tuberculata N. E. Brown. and Its Chemical Characterization

Present research was planned to assess the in vitro and in vivo anti-arthritic potential of Caralluma tuberculata N. E. Brown. methanolic (CTME) and aqueous (CTAQ) extracts. Chemical characterization was done by high-performance liquid chromatography and gas chromatography–mass spectrometry analysis. The Complete Freund’s Adjuvant (CFA) was injected in left hind paw of rat at day 1 and dosing at 150, 300 and 600 mg/kg was started on the 8th day via oral gavage in all groups except normal and disease control rats (which were given distilled water), whereas methotrexate (intraperitoneal; 1 mg/kg/mL) was administered to standard control. The CTME and CTAQ exerted significant (p < 0.01–0.0001) in vitro anti-arthritic action. Both extracts notably reduced paw edema, and restored weight loss, immune organs weight, arthritic score, RBCs, ESR, platelet count, rheumatoid factor (RF), C-reactive protein, and WBCs in treated rats. The plant extracts showed significant (p < 0.05–0.0001) downregulation of tumor necrosis factor-α, Interleukin-6, -1β, NF-κB, and cyclooxygenase-2, while notably upregulated IL-4, IL-10, I-κBα in contrast to disease control rats. The plant extracts noticeably (p < 0.001–0.0001) restored the superoxide dismutase and catalase activities and MDA levels in treated rats. Both extracts exhibited significant anti-arthritic potential. The promising potential was exhibited by both extracts probably due to phenolic, and flavonoids compounds.     

Novel functionalized cellulose derivatives fabricated with Cu nanoparticles: synthesis,characterization and degradation of organic pollutants

Cellulose - In this study, microcrystalline cellulose (MCC) was modified to oxidized cellulose (OC), 6-deoxycellulose hydrazide and 6-deoxycellulose (N,N-diethyl)amine (MCC-Hyd and MCC-DEM)...     

Structural and magnetic properties of nano-crystalline FeCoNiN thin films

Iron cobalt nickel nitride (FeCoNiN) thin films are prepared by sol-gel spin coating route. The structural, magnetic and surface properties of the thin films are evaluated. The crystalline nature of thin films was enhanced upon annealing, leading to increased crystallite size. The X-ray diffraction shows mixed phases with crystallite size in the range of 20–26.93 nm. Thin films show ferromagnetism at room temperature. Coercivity and saturation magnetization are in the range of 642–716 Oe and 2.5–7.5 emu/cm³ respectively. Both coercivity and saturation magnetization increased with annealing of thin films. Magnetic properties are related to the crystallinity of thin films. The increase in crystallite size results into an increase of magnetic properties. Rectangular shaped particles are seen on the surface of thin films. The same type of grains can be seen on the surface of thin films which confirmed the formation of FeCoNiN as predicted by XRD. These novel thin films might be used in memory devices and optoelectronic applications.     

Mild,Selective Oxidation of Aromatic Alcohols Using β-Cyclodextrin-Functionalized Glass Microparticles: Characterization,Stability, and Application

The surface of glass microparticle (GMP) was functionalized with β-cyclodextrin (→ GMP-β-CD) and was characterized by x-ray photoelectron spectroscopy (XPS). GMP-β-CD was used to catalyze oxidation of alcohols into aldehydes and katones with excellent yield (86–92%). The modified surface of GMP-β-CD showed no change or degradation after repeated use as confirmed from XPS analysis after 10 cycles.

[Supplementary materials are available for this article. Go to the publisher's online edition of Synthetic Communications® for the following free supplemental resource(s): Full experimental and spectral details.]     

Simultaneous preconcentration and determination of 2,4‐D,alachlor and atrazine in aqueous samples using dispersive liquid–liquid microextraction followed by high‐performance liquid chromatography ultraviolet detection

Dispersive liquid–liquid microextraction coupled with high‐performance liquid chromatography‐ultraviolet detection as a fast and inexpensive technique was applied to the simultaneous extraction and determination of traces of three common herbicides, 2,4‐D, alachlor and atrazine, in aqueous samples. The critical experimental parameters, including type of the extraction and disperser solvents as well as their volumes, sample pH, salt addition, extraction time and centrifuging time, and speed were investigated and optimized. Under the optimum conditions, the calibration graphs found to be linear in the range of 0.3–200 μg/L with limits of detection in the range of 0.05–0.1 μg/L. The relative standard deviations were in the range of 4.5–6.2% (n = 7). The relative recoveries of well, tap, and river water samples which have been spiked with different levels of herbicides were 92.0–107.0, 82.0–104.0, and 82.0–86.0%, respectively.     

Synthesis of Cholesterol-Conjugated Magnetic Nanoparticles for Purification of Human Paraoxonase 1

Human serum paraoxonase 1 (PON1) is known as an antioxidant and is also involved in the detoxification of many compounds. In this study, a novel purification strategy was employed to purify the PON1 by using cholesterol-conjugated magnetic nanoparticles. Magnetic nanoparticles were synthesized and conjugated with cholesterol through diazotized p-aminohippuric acid. In Fourier transform infrared spectrum of cholesterol-p-aminohippuric acid-Fe₃O₄ nanoparticles, the appearance of peaks at 3,358.3, 1,645 cm⁻¹, and at 2,334.9 cm⁻¹ confirmed the conjugation. The molecular weight of purified PON1 was nearly 45 kDa on sodium dodecyl sulfate (SDS)–polyacrylamide gel electrophoresis (PAGE), and isoelectric point was 5.3. The specific activity was 438 U mg⁻¹ protein, and the purification fold was 515 with 73% yield. The K _m values were 1.3 and 0.74 mM with paraoxon and phenyl acetate, respectively. Western blot of 2D-PAGE confirmed the homogeneity and stability of the enzyme. Mg⁺², Mn⁺², glycerol, (NH₄)₂SO₄, PEG 6000, Triton X-100, and phenylmethylsulfonyl fluoride did not show any effect on activity. Pb⁺², Co⁺², Zn²⁺, ethanol, β-mercaptoethanol, and acetone reduced the activity while Ni²⁺, Cd²⁺, Cu²⁺, iodoacetic acid, SDS, dimethylformamide, DMSO inhibited the activity. In vitro enzyme activity was slightly reduced by acetyl salicylic and acetaminophen and reduced 50% with amino glycosides and ampicillin antibiotics at concentrations of 0.6 and 30 mg ml⁻¹, respectively. This is the first report for the synthesis of cholesterol-conjugated magnetic nanoparticles for simple purification of PON1 enzyme.     

Analysis of Solvent Effect on Mechanical Properties of Poly(ether ether ketone) Using Nano-indentation

Poly (ether ether ketone)(PEEK) is a high-performance semi-crystalline thermoplastic polymer.Exposure of the polymeric surface to solvents can have a strong effect like softening/swelling of polymeric network or dissolution.In this study, nano-indentation analysis was performed to study the effect of acetone on the surface mechanical properties of PEEK using different exposure time.The experiments were performed with a constant loading rate (10 nm/s) to a maximum indentation displacement (1000 nm).A 30-second hold segment was included at the maximum load to account for any creep effects followed by an unloading segment to 80% unloading.The indentation hardness and the elastic modulus were computed as a continuous function of the penetration displacement in the continuous stiffness mode (CSM) indentation.The experimental data showed that the peak load decreased from ~5.2 mN to ~1.7 mN as exposure time in solvent environment increased from 0 to 18 days.The elastic modulus and the hardness of PEEK samples also displayed a decreasing trend as a function of exposure time in the solvent environment.Two empirical models were used to fit the experimental data of hardness as a function of exposure time which showed a good agreement with the experimental values.     

One-sided Perron Differential Inclusions

The main qualitative properties of the solution set of almost lower (upper) semicontinuous one-sided Perron differential inclusion with state constraints in finite dimensional spaces are studied. Using the technique introduced by Veliov (Nonlinear Anal 23:1027–1038, 1994) we give sufficient conditions for the solution map of the above state constrained differential inclusion to be continuous in the sense of Hausdorff metric. An application on the propagation of the continuity of the state constrained minimum time function associated with the nonautonomous differential inclusion and the target zero is given. Some relaxation theorems are proved, which are used afterward to derive necessary and sufficient conditions for invariance.     

Generalizations of Nekrasov-Okounkov Identity

Nekrasov-Okounkov identity gives a product representation of the sum over partitions of a certain function of partition hook length. In this paper, we give several generalizations of the Nekrasov-Okounkov identity using the cyclic symmetry of the topological vertex.