In the present work, a series of butyl methacrylate/1-hexene copolymers were synthesized, and their efficiency as viscosity index improvers, pour point depressants, and shear stabilizers of lube oil was investigated. The effect of 1-hexene molar ratio, type, and concentration of Lewis acids on the incorporation of 1-hexene into the copolymer backbone was investigated. The successful synthesis of the copolymers was confirmed through FTIR and 1H NMR spectroscopy. Results obtained from quantitative 1H NMR and GPC revealed that an increase in the molar ratio of 1-hexene to butyl methacrylate, along with concentration of Lewis acids led to an increase in 1-hexene incorporation and a reduction in Mn and Ð. Similar trends were observed when the Lewis acid changed from AlCl₃ to organometallic acids. The maximum 1-hexene incorporation (26.4%) was achieved for sample BHY3, with a [1-hexene/BMA] ratio of 4 mol% and a [Yb(OTf)₃/BMA] ratio of 2.5 mol%. Evaluation of the synthesized copolymers as lube oil additives demonstrated that the viscosity index was more significantly influenced by samples with higher molecular weight. Sample BHA13 represents maximum VI of 137. The copolymer containing Yb(OTf)₃ as a catalyst exhibited superior efficiency as a pour point depressant. Furthermore, sample BHY3 showed the lowest shear stability index (6.4).

In response to the challenges of climate change, this study explores the use of moringa pod powder as reinforcement in the manufacture of compressed earth bricks to promote sustainable building materials. The objective is to evaluate the impact of African locust bean pod powder on the mechanical properties of the bricks. Two types of soils from Togo were characterized according to geotechnical standards. Mixtures containing 8% African locust bean pod powder at various particle sizes (0.08 mm, 2 mm, and between 2 and 5 mm) were formulated and tested for compression and tensile strength. The results show that the addition of African locust bean pod reduces the mechanical strength of the bricks compared to the control sample without pods, with strengths ranging from 0.697 to 0.767 MPa, compared to 0.967 to 1.060 MPa for the control. However, the best performances for the mixtures were obtained with a fineness of less than 2 mm. This decrease in performance is attributed to several factors, including inadequate water content and suboptimal preparation and compaction methods. Optimizing formulation parameters is necessary to maximize the effectiveness of African locust bean pods. This work highlights the valorization of agro-industrial waste, paving the way for a better understanding of bio-based materials and future research for sustainable construction.

The global economic recession has caused pessimism in terms of prospects of sales recovering in the future. The present study is an attempt to investigate the cost stickiness behavior by focusing on specific characteristics of companies. The research was done through documentary analysis and access to quantitative data, with the use of statistical methods for analysis as panel data. The statistical population of the actual study included all companies listed on the India stock exchange from 2017 to 2021. They were selected after screening 128 listed companies. The regression method was used to examine the relationship between variables and to present a forecast model. The results of testing the first hypothesis showed that companies’ costs are sticky and according to the results of this hypothesis, an increase in costs when the level of activity increases is greater than the level of reduction in costs when the volumes of the activities are decreased. The results of the second hypothesis showed a remarkable relationship between the cost stickiness and specific characteristics of companies (size, number of employees, long-term assets, financial leverage, and accuracy of profits forecast). Based on the third hypothesis, there is a notable difference between cost stickiness at different levels of specific characteristics of companies. Therefore, the results show that environmental uncertainty such as COVID-19, increases cost stickiness.

We have studied the effect of the series resistance on the heating of the cathode, which is based on carbon nanotubes and serves to realize the field emission of electrons into the vacuum. The experiment was performed with the single multi-walled carbon nanotube (MCNT) that was separated from the array grown by CVD method with thin-film Ni-Ti catalyst (nickel 4 nm/Ti 10 nm). The heating of the cathode leads to the appearance of a current of the thermionic emission. The experimental voltage current characteristic exhibited the negative resistance region caused by thermal field emission. This current increases strongly with increasing voltage and contributes to the degradation of the cold emitter. The calculation of the temperature of the end of the cathode is made taking into account the effect of the phenomenon that warms up and cools the cathode. We have developed a method for processing of the emission volt-ampere characteristics of a cathode, which relies on a numerical calculation of the field emission current and the comparison of these calculations with experiments. The model of the volt-ampere characteristic takes into account the CNT’s geometry, properties, its contact with the catalyst, heating and simultaneous implementation of the thermionic and field emission. The calculation made it possible to determine a number of important parameters, including the voltage and current of the beginning of thermionic emission, the temperature distribution along the cathode and the resistance of the nanotube. The phenomenon of thermionic emission from CNTs was investigated experimentally and theoretically. The conditions of this type emission occurrence were defined. The results of the study could form the basis of theory of CNT emitter’s degradation.

"One Village, One Product" is an effective measure to fully tap local resources, develop rural characteristic industries, innovate economic growth methods, and drive rapid regional economic development. Rural tourism is an important component of industrial revitalization in rural revitalization. Under the "one village, one product" model, the development of rural tourism needs to optimize the industrial structure, explore unique culture, vigorously promote the construction of "beautiful rural characteristic countryside", achieve the transformation and upgrading of traditional rural tourism, and promote the high-quality development of rural characteristic tourism.