Controlled Metal–Support Interactions in Au/CeO2–Mg(OH)2 Catalysts Activating the Direct Oxidative Esterification of Methacrolein with Methanol to Methyl Methacrylate

The strong metal–support interaction (SMSI) between the three components in Au/CeO2–Mg(OH)2 can be controlled by the relative composition of CeO2 and Mg(OH)2 and by the calcination temperature for the direct oxidative esterification of methacrolein (MACR) with methanol to methyl methacrylate (MMA). The composition ratio of CeO2 and Mg(OH)2 in the catalyst affects the catalytic performance dramatically. An Au/CeO2 catalyst without Mg(OH)2 esterified MACR to a hemiacetal species without MMA production, which confirmed that Mg(OH)2 is a prerequisite for successful oxidative esterification. When Au/Mg(OH)2 was used without CeO2, the direct oxidative esterification of MACR was successful and produced MMA, the desired product. However, the MMA selectivity was much lower (72.5%) than that with Au/CeO2–Mg(OH)2 catalysts, which have an MMA selectivity of 93.9–99.8%, depending on the relative composition of CeO2 and Mg(OH)2. In addition, depending on the calcination temperature, the crystallinity of the CeO2–Mg(OH)2 and the surface acidity/basicity can be remarkably changed. Consequently, the Au-nanoparticle-supported catalysts exhibited different MACR conversions and MMA selectivities. The catalytic behavior can be explained by the different metal–support interactions between the three components depending on the composition ratio of CeO2 and Mg(OH)2 and the calcination temperature. These differences were evidenced by X-ray diffraction, X-ray photoelectron spectroscopy, and CO2 temperature-programmed desorption. The present study provides new insights into the design of SMSI-induced supported metal catalysts for the development of multifunctional heterogeneous catalysts.

Numerical simulation for increasing the sand mastic adaptation of repairing the breakwater

As a breakwater gradually becomes obsolete, it becomes vulnerable to loss of its original functions and finally occurs corruption due to cavitation, scours inside, etc. The mortar grouting method, which has been in general applied in many cases, would invoke serious issues such as coastal environmental pollutions because of spilled-out cement before curing on the near sea. Thus, the sand mastic that utilizes the mastic asphalt becomes focused on as a substitute. However, the related study is hard to find in the domestic literature. In this study, therefore, the workability of sand mastic when filling up the cavitation inside a breakwater was evaluated with a 3-D numerical model, FLOW-3D. It was intended to propose the workability index (WI) of sand mastic based on the diffusion diameter. It has been shown that the temperature and the composition ratio of the asphalt are the most significant parameters on the rheologic characteristics of the sand mastic. As a result, it is recommended that the asphalt composition above 16% and the initial temperature above 150℃ when applying with a breakwater with inside cavitation.

Offensive/Defensive Talent and Sporting Success in Football: Evidence From the Big Five European Leagues

Over the past decade, the sustained growth of the football business has been associated with clubs’ interest in investing in players’ talent, which has boosted both the transfer market and players’ salaries. However, players’ talent is heterogeneous, given that both defensive and offensive talent are required. Therefore, clubs have to decide on the optimal talent composition, taking into account the differences in the cost and the productivity of both talents. The article shows that, firstly, clubs’ talent composition (ratio between offensive and defensive talent) presents significant differences over time among the Big Five European leagues. Secondly, the talent composition is consistent with maximizing sporting performance (or profit maximization) in the case of Serie A, but not in the case of Bundesliga. Results for Premier League, LaLiga and Ligue 1, are not conclusive with a few exceptions associated with the top teams.

SIFAT FISIK DAN MEKANIK PAPAN PARTIKEL BERDASARKAN KOMPOSISI LIMBAH KULIT BUAH PINANG DAN LIMBAH KAYU GERGAJIAN DENGAN VARIASI KADAR PEREKAT

This research aimed to analyze the physical and mechanical properties of particleboard based on the composition of raw materials and adhesive content as well as their interaction with the optimum quality of particle boards that meet JIS A 5908-2003 standards. The particleboard was made with a size of 30 cm x 30 cm x 1 cm with a target density of 0.7 g/cm³. The pressing was done at a temperature of 140°C for 8 minutes with a pressure of 25 kg/cm². The composition ratio of betel nut peel waste and sawdust varied, namely 60% betel nut peel waste: 40% sawdust, 50% betel nut peel waste: 50% sawdust, and 40% betel nut peel waste: sawdust 60%. The adhesive used was Urea Formaldehyde with a concentration of 12%, 14%, and 16%. The results showed that all test values met the JIS A 5908: 2003 standard except the MOE test. The optimum value of particle board of betel nut peel and sawdust was with a composition ratio of 50% betel nut peel waste: 50% sawdust, 16% adhesive content, with a density value of 0.6876 g/cm³, a moisture content of 9,4530%, water absorption 34,5306%, thickness expansion 8,2508%, MOE 12432,6243 kg/cm², MOR 205,8462 kg/cm², adhesive firmness 2,2530 kg/cm², screw holding strength 81,6861 kg/cm².Keywords: adhesive content, betel nut peel waste, material composition, mechanical properties, particleboard, physical.Abstrak Penelitian ini bertujuan untuk menganalisis sifat fisik dan mekanik papan partikel berdasarkan komposisi bahan baku dan kadar perekat serta interaksi keduanya terhadap kualitas papan partikel yang optimum serta memenuhi standar JIS A 5908-2003. Papan partikel dibuat dengan ukuran 30 cm x 30 cm x 1 cm dengan target kerapatan 0,7 g/cm³. Pengepresan pada suhu 140°C selama 8 menit dengan tekanan 25 kg/cm². Perbandingan komposisi kulit buah pinang dan serbuk kayu gergaji bervariasi yaitu kulit buah pinang 60% : serbuk kayu gergaji 40%, kulit buah pinang 50% : serbuk kayu gergaji 50% dan kulit buah pinang 40% : serbuk kayu gergaji 60%. Perekat yang digunakan adalah Urea Formaldehida dengan konsentrasi 12%, 14% dan 16%. Hasil penelitian menunjukkan semua nilai uji memenuhi standar JIS A 5908 : 2003 kecuali uji MOE. Nilai papan partikel kulit buah pinang dan serbuk kayu gergaji optimum dengan perbandingan komposisi kulit buah pinang 50% : serbuk kayu gergaji 50%, kadar perekat 16%, dengan nilai densitas 0,6876 g/cm³, kadar air 9,4530%, daya serap air 34,5306%, pengembangan tebal 8,2508%, MOE 12432,6243 kg/cm², MOR 205,8462 kg/cm², Keteguhan rekat 2,2530 kg/cm², kekuatan menahan sekrup 81,6861 kg/cm².Kata kunci : papan partikel, kadar perekat, kulit buah pinang, komposisi bahan, sifat fisik dan mekanik.

Compositional Engineering of FAPbI3 Perovskite Added MACl with MAPbBr3 or FAPbBr3

Many attempts have been made to stabilize α-phase formamidinium lead iodide (α-FAPbI3) using mixed cations or anions with MA+, FA+, Br− and I−. A representative method is to stably produce α-FAPbI3 by adding methylammonium lead (MAPbBr3) to the light absorption layer of a perovskite solar cell and using methylammonium chloride (MACl) as an additive. However, in the perovskite containing MA+ and Br−, the current density is lowered due to an unwanted increase in the bandgap; phase separation occurs due to the mixing of halides, and thermal stability is lowered. Therefore, in this study, in order to minimize the decrease in the composition ratio of FAPbI3 and to reduce MA+, the addition amount of MACl was first optimized. Thereafter, a new attempt was made to fabricate FAPbI3 perovskite by using formamidinium lead bromide (FAPbBr3) and MACl together as phase stabilizers instead of MAPbBr3. As for the FAPbI3-MAPbBr3 solar cell, the (FAPbI3)0.93(MAPbBr3)0.07 device showed the highest efficiency. On the other hand, in the case of the FAPbI3-FAPbBr3 solar cell, the (FAPbI3)0.99(FAPbBr3)0.01 solar cell with a very small FAPbBr3 composition ratio showed the highest efficiency with fast photovoltaic performance improvement and high crystallinity. In addition, the FAPbI3-FAPbBr3 solar cell showed a higher performance than the FAPbI3-MAPbBr3 solar cell, suggesting that FAPbBr3 can sufficiently replace MAPbBr3.