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Promoting safe tires with low external rolling noise increases the environmental efficiency of road transport. Although tire builders have been striving to reduce emitted noise, the issue's sophisticated nature has made it difficult. This article aims to make the problem straightforward, relying on recent significant improvements in statistical science. In this regard, the prediction ability of new methods in this field, including support vector machine, relevance vector machine, and convolutional neural network, along with the new architecture of the neural network is compared. Tire noise is measured under the coast-by condition. Two training strategies are proposed: extracting features from a tread pattern image and directly importing an image to the model. The relevance vector method, which is trained using the first strategy, has provided the most accurate results with an error of 0.62 dB(A) in predicting the total noise level. This precise model is used instead of experimentation to analyze the sensitivity of tire noise to its parameters using a small central composite design. The parametric study reveals striking tips for reducing noise, especially in terms of interactions between parameters that have not previously been shown. Finally, a novel two-stage approach for reducing noise by tread pattern optimization is proposed, inspired by two regression models derived from statistical investigation and variance analysis. Changes in tread pattern specifications of two case studies and their randomization have resulted in a reduction of 3.2 dB(A) for a high-noise tire and 0.4 dB(A) decrement for a quieter tire. [ABSTRACT FROM AUTHOR]

In the present study, a hollow MgO/SiO2 nanocatalyst with high alkaline properties was prepared. This heterogeneous catalyst was prepared in several steps to create a great active area and decrease the density of the catalyst. The alkaline hollow catalyst framework was applied for the reaction of cyclohexanone, malononitrile and benzaldehyde for synthesis of 1 H-isocromene therough the Michael addition and aldol condensation reaction at room temperature. In this method, all of the done reactions were excellent in the yields of products and reaction times. At the end of the reaction, the nanocatalyst separated by simple filtration and reuse in several runs elsewhere. In the present study, hollow MgO/SiO2 nanocatalyst with great base properties was made. Thisheterogeneous catalyst was a synthesis in several steps to create a great active area and decreasethe density of the catalyst [ABSTRACT FROM AUTHOR]

(6R)-1-((3S)-3'-Amino-6-chloro-2',2'-dicyano-2-oxo-7'-propyl-6',7',8',8a'-tetrahydro-2'h-spir... 0.73 g, 88% yield, 35 min, white solid; m.p.: 237-239 °C, IR (KBr): v = 3663, 3553, 3372, 3216, 2908, 2856, 2216, 1743, 1662, 1589, 1475, 1431, 1289, 1184, 1098, 1015, 832, 651, 606 cm SP -1 sp ; SP 1 sp H NMR (400 MHz, DMSO-d6) 10.84 (s, 2H, NH,NH), 8.34 (s, 1H, NH), 7.87 (s, 2H, CH, NH), 7.28 (s, 2H, NH2), 6.76-7.14 (m, 6H), 5.77 (s, 1H), 4.12 (s, 1H), 2.50 (s, 3H), 1.50 (s, 6H), 1.05-1.18 (d, J = 53.6 Hz, 9H), 0.79 (s, 6H), 0.16 (s, 2H); SP 13 sp C{ SP 1 sp H} NMR (100 MHz, DMSO I d i SB 6 sb ) 173.9, 173.70, 158.4, 156.8, 156.8, 148.8, 147.1, 141.2, 131.0, 129.5, 129.1, 127.0, 126.7, 126.2, 126.0, 125.9, 125.75, 122.7, 121.3, 120.7, 116.8, 116.6, 115.6, 114.8, 110.9, 110.6, 81.3, 80.6, 54.8, 53.8, 52.85, 39.8, 39.6, 38.6, 38.4, 38.1, 38.1, 37.4, 29.8, 19.2, 14.0; MS (EI), m/z (%) = 835 ([M] SP + sp , 0.8), 834 (1.5), 444 (24), 412 (67),392 (26), 323 (36), 308 (38), 187 (50), 166 (64), 114 (45), 77 (30), 58 (60), 41 (100). [Extracted from the article]

In this research, it was displayed an efficient method for the one‐pot reaction of cyclohexanone, benzaldehyde and malononitrile for the synthesis of 4H‐chromenes by using CoFe2O4/lamellar mesopore silica anchored to melamine as a magnetic nanocatalyst. This nanocatalyst was prepared in several steps and discriminated by XRD, FT‐IR, SEM, VSM, TGA and BET techniques. The catalyst has a large active base site that has functionalized in both the surface and the pore of nanostructure. The advantages of magnetic nanocatalyst were simple accessible, heterogeneous nanocatalyst, easy work up and reusability. The various derivatives of 4H‐chromenes were synthesized in the presence of CoFe2O4/lamellar mesopore silica/melamine magnetic nanocatalyst with the excellent yields and appropriate times. The products were identified by the melting point, FT‐IR, 1H NMR, 13C NMR and C.H.N techniques. [ABSTRACT FROM AUTHOR]

Designing protocols for the preparation of nanocatalyst in order to increase the yield of an organic reaction is a challenging task in modern chemistry. CaMgFe2O4 is a base nanocatalyst that prepared through sol‐gel method. This nanocatalyst has used for the synthesis of 1H‐isocromenes, 4H‐chromenes and ortho‐aminocarbonitrile tetrahydronaphthalenes through the multi‐component reactions. The starting materials for all of the reactions are cyclohexanone, benzaldehyde and malononitrile and the reaction followed with Michael addition and cyclization. Therefore, the different multicomponent reactions from the same materials arranged by using CaMgFe2O4 base nanocatalyst. The catalyst identified with XRD, EDX, SEM, VSM and XPS techniques and the organic compounds recognized with melting point, FT‐IR, 1H NMR and 13C NMR analyses. [ABSTRACT FROM AUTHOR]

A facile and rapid multicomponent synthesis of pharmaceutically diverse 1H‐isochromenes, 4H‐chromenes, and ortho‐aminocarbonitrile tetrahydronaphthalenes has been developed from benzaldehyde, malononitrile, and cyclohexanone. Three different methods from the same reactants, solvent, temperature, and catalyst lead to three products with excellent yields. All the reactions were followed with the Michael addition and cyclization. In this study, morpholine was used as an active metal‐free base catalyst that increases the yields of products and decreases the time of reactions. [ABSTRACT FROM AUTHOR]