Finite Element Analysis of a Spur Gear Considering Mass Relief Strategies

This paper deals with analyzing the structural influence of mass reliefs in spur gears. For this purpose, a system composed of pinion and a gear was designed, such that for gear several geometries were designed with different reliefs shapes and soul thicknesses. From the proposed geometries, finite element analysis (FEA) was performed, and the tooth stresses of each model were compared with the solid gear. From the results, it was observed that the tooth stresses are reduced in some cases. Besides, from the aforementioned cases, it is possible to observe that the maximum stresses may take place in its core instead of the teeth (rim area). On the other hand, based on other cases, the core thickness plays an important role as a criterion that defines the local stress.

The Relationships among Quality of Online Education, Learning Immersion, Learning Satisfaction, and Academic Achievement in Cooking-Practice Subject

The purpose of this study was to identify the problems of online education perceived by learners in a time when non-face-to-face online lectures are conducted due to the spread of COVID-19, and suggest measures to improve educational outcomes. Therefore, the structural influence of cooking practice on the quality of online lessons, learning immersion, learning satisfaction, and the achievement felt by learners was verified. The sample of the study was a college student majoring in cooking, and a total of 509 responses were used for analysis. The results of the study are as follows: First, it was analyzed that there was a significant influence on learning immersion in the order of content, interaction, and educational environment among the quality of online classes. Second, among the quality of online classes, class content and educational environment showed positive (+) influence on learning satisfaction. Third, learning immersion and learning satisfaction showed a positive influence on academic achievement. Fourth, in the direct effect of online class quality on academic achievement, it was analyzed that only class content had a positive (+) effect. Based on the results of this study, the provision of learning materials with detailed explanations was suggested in the online cooking practice class rather than providing a simple cooking video. In addition, it was suggested that as a way to improve academic achievement of online education, it is necessary to provide content that allows learners to immerse themselves in class, as well as class content and educational environment, and consider learning satisfaction.

The Impact of Halogen Substituents on the Synthesis and Structure of Co-Crystals of Pyridine Amides

Strategies for co-crystal synthesis tend to employ either hydrogen- or halogen-bonds between different molecules. However, when both interactions are present, the structural influence that they may exert on the resulting assembly is difficult to predict a priori. To shed some light on this supramolecular challenge, we attempted to co-crystallize ten aliphatic dicarboxylic acids (co-formers) with three groups of target molecules; N-(pyridin-2-yl)picolinamides (2Pyr-X), N-(pyridin-2-yl)nicotinamides (3Pyr-X), N-(pyridin-2-yl)isonicotinamides (4Pyr-X); X=Cl/ Br/ I. The structural outcomes were compared with co-crystals prepared from the non-halogenated targets. As expected, none of the reactions with 2Pyr-X produced co-crystals due to the presence of a very stable intramolecular N-H···N hydrogen bond. In the 3Pyr series, all six structures obtained showed the same synthons, –COOH···N(py) and –COOH···N(py)-NH, that were found in the non-halogenated parent 3Pyr and were additionally accompanied by structure directing X···O(OH) interactions (X=Br/I). The co-crystals of the unhalogenated parent 4Pyr co-crystals assembled via intermolecular –COOH···N(py) and –COOH···N(py)-NH synthons. Three of the analogues 4Pyr-X co-crystals displayed only COOH···N(py) and –COOH···N(py)-NH interactions. The three co-crystals of 4Pyr-X with fumaric acid (for which no analogues structures with 4Pyr are known) formed –COOH···N(py)-NH and –NH···O=C hydrogen bonds and showed no structure-directing halogen bonds. In three co-crystals of 4Pyr-I in which –COOH···N(py)-NH hydrogen bond was present, a halogen-bond based –I···N(py) synthon replaced the –COOH···N(py) motif observed in the parent structures. The structural influence of the halogen atoms increased in the order of Cl < Br < I, as the size of σ-holes increased. Finally, it is noteworthy that isostructurality among structures of the homomeric targets was not translated to structural similarities between their respective co-crystals.

Structural influence of antibody recruiting glycodendrimers (ARGs) on antitumoral cytotoxicity

A series of Antibody Recruiting Glycodendrimer (ARG) was screened against the melanoma cell line M21. We identified lead ARGs that promote up to 57% of selective cytotoxicity in the presence of human serum as the unique source of immunity effectors.

Structural influence of a dichalcogenopheno-1,3,4-chalcogenodiazole comonomer on the optoelectronic properties of diketopyrrolopyrrole-based conjugated polymers

Dichalcogenopheno-1,3,4-chalcogenodiazole units are newly designed and introduced into dithienyl diketopyrrolopyrrole-based copolymers showing promising optoelectronic characteristics.