Different methods for the synthesis of pyridine derivatives as well as the chemical reactivity profiles and structures of these substances are reviewed. The utility of these compounds as precursors is emphasized in the synthesis of many heterocycles that are pharmacologically active organic compounds and agrochemicals. This review results from a literature survey containing some synthetic methods and applications of pyridine derivatives.

The number of types of wire welding that circulate on the market and the development of welding technology, especially related to current welding, create a lack of information related to the quality of welding results for several types of materials. This can cause the strength of the welding connection to not be maximized. Therefore, this study aims to optimize the use of three types of wire welding and three current welding on the strength of the welding connection in two types of material testing using the response surface methodology. Box-Behnken, coupled with the RSM and the desirability function, was used to optimize the strength of the welding connection of the wire types (RD-46, LB-52, and RB-26), and current welding (100, 130, and 160 A) against two types of material testing (IWF-150 and ASTM-A517-G70). The strength of the welding connection observed in response included the tensile strength, Charpy impact-absorbed energy, hardness values in the welding metal and the hardness values in the main metal. Optimization of the strength of the welding connection in this study recommends the application of wire types RB-26, current welding of 100 A, and ASTM-A517-G70 material testing with the highest desirability value of 71.6%. Optimization of tensile strength, Charpy impact-absorbed energy, hardness values in welding metal, and hardness values in main metal by applying this parameter are 575.64 MPa, 110.69 J, 216.75 (HV10) and 126.6 (HV10), respectively. The results proved that an appropriate welding connection strength could be achieved using wire welding types and current welding in material testing.

In this article, hyperelastic material models that state consistent polynomial expansions of the stored energy function are discussed. The approach follows from the multiplicative decomposition of the deformation gradient. Some advantages of the third-order expansion model over the five-parameter Rivlin model using Treloar’s experimental data are shown. The models are qualitatively and quantitatively compared to highlight these advantages of the discussed model.

This study presents data on the development and research of cryogenic-vibration grinding process modes which would ensure an efficient grinding process of complex composite systems with a high degree of heterogeneity of components in their composition of products such as fluoroplast, bismuth oxide and tungsten carbide. The general regularities of low-temperature processing and grinding of non-degassed elastomers are established. A method has been tested that establishes the regularities of cryogenic grinding and ultrasonic homogenization of a complex mechanical system, the microstructure and dispersed compositions of the ground material have been determined.

Reaction of N-cyanoguanidine with acid chlorides and aroylisothiocyanates gave the respective; N-(N-cyanocarbamimidoyl)aryl-2-carboxamides 1-5 and N-[(N-cyanocarbamimidoyl)carbamothioyl]benzamides 6-10, which have a Neonictinoid insecticide’s active group moiety (=N–CN). They have more toxicological activity against wheat Aphid (Schizaphis graminum) than Spodoptera littoralis.

Due to the complicated problems coming from excessive applications of insecticides, searching for safe substitutes to these insecticides has become a necessity. Thus, the insect growth regulators are candidates to be used in such concern. Comparative studies of the effects of three compounds, 2-benzoyl-N-phenylhydrazine-1-carbothioamide (1), 2-(cyanoacetyl)-N-phenylhydrazine-1-carboxamide (2) and N-(2-(2-cyanoacetyl)hydrazinecarbonothioyl)furan-2-carboxamide (3) (an insect growth regulator inhibiting chitin synthesis), were conducted on Spodoptera littoralis (Boisduval, 1833). The compounds, orally administered, caused larval mortality proportional to the concentrations in the food source. larvae were unable to complete the molting process and died in the old larval cuticle. Larvae contaminated by sublethal doses completed their development to adulthood. N-(2-(2-cyanoacetyl)hydrazinecarbonothioyl)furan-2-carboxamide (3) is more active than the other compounds have LC50 17.082 ppm for 2nd instar larvae and 60.832 ppm for 4th instar larvae.

The beam-column joints are designed to have sufficient capacity under earthquake loads. This requirement needs design details of reinforcement that fulfill the seismic criteria and adequate compaction of concrete. Using Self Compacting Concrete (SCC) material can solve the difficulty of compacting conventional concrete due to the close reinforcement distance. This study aimed to analyze the behavior of the Exterior Beam-column Joints (EBJ) using SCC as materials with a variation of shear reinforcements to withstand cyclic lateral loads. The analysis was carried out using the ANSYS software and the Finite Element Method. The analysis included hysteresis curves, stress contours, ductility, stiffness, and structural strength. The performance of an EBJ without shear reinforcement (EBJ-S1 model) was compared to other EBJs using horizontal (EBJ-S2 model) and diagonal (EBJ-S3 model) shear reinforcements in the joint zones. The results showed that horizontal and diagonal shear reinforcement in the joint zones affected the performance of the EBJs in resisting cyclic lateral loads as the representative of earthquake loads. The EBJ without shear reinforcement could withstand compressive stresses of 3.33 to 17.22 MPa, while both EBJs using horizontal and diagonal shear reinforcement achieved the same compressive stresses range of 3.33 to 20 MPa. The EBJ with diagonal reinforcement performed a wider compressive area of stress contour than the EBJ of horizontal reinforcement. The EBJ-S3 model achieved the highest ductility value of 4.733 with diagonal shear reinforcements because it achieved the highest ultimate displacement of the other EBJ models.

In this review we systematized the theoretical and experimental data concerning the versatile approaches for the synthesis of N-acylphenothiazines. The aim of the study was to compile the literature reported worldwide in the past 20 years. This article also reviewed the analysis of pharmacological activities of these heterocycles as one of the promising chemotherapeutic objects for the modern bioorganic and medicinal chemistry. It has been hypothesized that the enormous biological potential of these moieties is due to the radical nature in the acyl moiety. Therefore, the present review will be a good contribution to the literature and will provide the platform for the medicinal chemistry researchers to carry out more studies aiming the N-acylphenothiazine moieties as the novel chemotherapeutic agents.

Peru is a country with plenty of renewable energy sources. However, its power demand depends on more than 50% of fossil fuels. Specifically, the power coming from the sun only represents 1% of the Peruvian energy matrix even though the territory has high radiation indexes. Therefore, the current analysis aims to search for the research situation of photovoltaic energy. Hence, this research looked for literature from RENATI and EBSCO, which provided 398 pieces of academic investigation. After applying the Prisma methodology to select the most relevant thesis and papers, we analyzed 48 elements. We found that the on-grid technology was the most viable in economic terms for projects related to business and electrification. At the same time, off-grid systems have been preferred for sanitation applications. Nonetheless, all the reviewed literature showed that photovoltaic technology positively impacted the environment and was as effective as conventional sources.

Biologically active organic compounds continue to attract great interest due to the wide variety of interesting applications observed for these compounds. This review results from the literature survey containing the organic compounds that are used as insect growth regulators with a focus on their mode of action and some synthetic routes.