Parameters Of Processes Research Articles

Global survey of hgcA-carrying genomes in marine and freshwater sediments: Insights into mercury methylation processes

Mercury (Hg) methylation is a microbially mediated process that produces methylmercury (MeHg), a bioaccumulative neurotoxin. A highly conserved gene pair, hgcAB, is required for Hg methylation, which provides a basis for identifying Hg methylators and evaluating their genomic composition. In this study, we conducted a large-scale omics analysis in which 281 metagenomic freshwater and marine sediment samples from 46 geographic locations across the globe were queried. Specific objectives were to examine the prevalence of Hg methylators, to identify horizontal gene transfer (HGT) events involving hgcAB within Hg methylator communities, and to identify associations between hgcAB and microbial biochemical functions/genes. Hg methylators from the phyla Desulfobacterota and Bacteroidota were dominant in both freshwater and marine sediments while Firmicutes and methanogens belonging to Euryarchaeota were identified only in freshwater sediments. Novel Hg methylators were found in the Phycisphaerae and Planctomycetia classes within the phylum Planctomycetota, including potential hgcA-carrying anammox metagenome-assembled genomes (MAGs) from Candidatus Brocadiia. HGT of hgcA and hgcB were identified in both freshwater and marine methylator communities. Spearman's correlation analysis of methylator genomes suggested that in addition to sulfide, thiosulfate, sulfite, and ammonia may be important parameters for Hg methylation processes in sediments. Overall, our results indicated that the biochemical drivers of Hg methylation vary between marine and freshwater sites, lending insight into the influence of environmental perturbances, such as a changing climate, on Hg methylation processes.

Criterion of construction and strategy of functioning of information and telecommunication system with protection against destructive effects

The creation of information and telecommunication systems with the integration of information transmission, reception and processing functions determines the need to find technical solutions to ensure its security and protection while increasing the intensity of information processes, improving technologies for unauthorized access to information areas and creating destructive effects. Joint fulfillment of requirements for information security and maintaining operational properties of the system, which regulate efficiency, efficiency and resource intensity of information exchange, is achieved in accordance with a minimum-margin rule, the essence of which is to find the maximum possible information losses and determine a strategy for achieving minimum values of these losses. Within the framework of the used approach, the best solution is to establish a set of parameters of transmitting and receiving devices and information processing means with the lowest loss value of the target function of information exchange under the most dangerous and effective destructive effects. Goal – justification of the criterion for construction and strategy of functioning of the information and telecommunication system with protection against destructive effects. The criterion of construction and strategy of operation of the information and telecommunication system are justified in order to achieve the best probabilistic-time indicators of information exchange with a balanced set of measures to ensure security and information protection in case of destructive impacts. Due to the variety and variability of the conditions for the manifestation of destabilizing factors, the parameters and reconfiguration schemes of telecommunication channels, as well as the operating modes of information processing devices, were established while achieving the effectiveness of meeting the information needs of subscribers according to the optimality criterion and setting indicators of the efficiency and resource consumption of the system according to the suitability criterion. Possibilities and options for adaptive, situational and reflective control of the information and telecommunication system in the interests of rational distribution of the information resource to achieve target functions and the use of technologies for ensuring security and protecting information from destructive influences are investigated. Automatic control of the system is at the stage of prohibiting destructive effects on the information area by maintaining components in states that most fully correspond to the goals and objectives of information exchange. Situational control of information security during transmission and reception, used, as a rule, at an early stage of implementation of the conflict component in the information process, is based on the identification of destabilizing factors based on the results of classification of current states and neutralization of threats due to the restructuring of the system operation regulations carried out. Reflexive control, the strategy of which is based on prediction and evaluation of changes in the parameters of information processes under destructive effects, is in the form of transferring components of the information and telecommunication system to the state of its own information equilibrium, which helps to maximize the target function of information exchange while minimizing the performance indicators of destructive effects carried out. Due to the expediency of consistent implementation of the above control strategies in assessing the degree of occurrence of threats to the information process, the vector of parameters of information objects and telecommunication channels must from the conditions for neutralizing the full set of predicted destabilizing factors be determined. A reasonable criterion for building an information and telecommunication system makes it possible to jointly search for technical solutions for creating receiving and transmitting devices and information processing means in order to achieve maximum performance indicators of information exchange under established limitations of efficiency and resource intensity. The developed rule for selecting the strategy for controlling components of the information and telecommunication system establishes time-frequency and space-energy distributions of information processes necessary to meet the information needs of subscribers when transmitting, receiving and processing information in different conditions for the manifestation of destructive threats. The obtained results form a methodological basis for building information and telecommunication systems with protection of information coming through their channels with increasing requirements for target functions of information exchange and strengthening system restrictions due to improvement of technologies for unauthorized access to information areas and creation of destructive effects.

Energy-technological quantum parameters of silicon in electronics

Theoretical and experimental material on silicon is presented, which, together with formal and experimental dependencies of energy technological processes, determines the parameters of integrated electronic circuits. It is shown that the fundamentals of quantum physics, the fine structure constants of electricity and magnetism, together with theoretical and experimental data on energy technology processes, make it possible to consider patterns for electronic structural materials. The relationships between Planck's constant, gravitational constant, speed of light, electrical constant, dielectric constant, electrical charges and mass for the element silicon are considered. Methodological issues of formalizing the parameters of energy technological processes, which determine the fine structure constant of silicon, are noted.

Research on construction parameters of stone columns for liquefaction mitigation in coral reef sand areas

For loose coral reef sand with high fines content located in strong earthquake zones, it is necessary to choose stone columns as a liquefaction mitigation ground improvement method that can consider both drainage and densification functions. Taking the Tibar Bay Port project in East Timor as an example, the bottom-feed technology of vibrating stone columns was developed, and typical coral reef sand sites with different fines contents were selected as trial test areas. Experimental research was performed to study the construction parameters for onshore and offshore stone column processes. Tests showed that the vibratory process control parameters, quality acceptance standards, and control procedures proposed through research meet the anti-liquefaction requirements for both drainage and densification effectiveness. The different construction characteristics of onshore and offshore stone columns were also analyzed. Considering the particularity of underwater stone column construction, the research results can be used for stone columns reinforced grounds similar to coral sand onshore and offshore.

Attrition and morphological analysis of CaCO3 corresponding to oxy-fuel circulating fluidized bed conditions

The specific surface area of CaCO3 has always been an essential parameter for various oxy-fuel combustion processes and chemical looping processes. However, the circulating of bed material through the furnace, cyclone and loop-seal in an oxy-fuel circulating fluidized bed (CFB) reactor may trigger the particle size changes as a result of rapid collisions among particles and friction with the inner refractory wall. Rather than considering only the effect of initial particle size, it is significantly important to emphasize on the change in limestone particle size due to in-reactor attrition. In addition, the changes are further enhanced with calcination reaction that occurred under high-temperature conditions. Herein an investigative account of limestone in a lab-scale CFB process was presented by using two types of fluidizing media (Air, CO2) to determine its attrition and morphological changes under simulated operating conditions for riser and loop-seal. A significant difference in attrition index was observed as calcination of limestone occurred at high temperature under air atmosphere which was not observed under CO2 condition. With similar cross-sectional area observed for both the tested (CO2 condition) and re-carbonated limestone, it was concluded that re-carbonation of calcined lime at high CO2 concentration in the loop-seal resulted in a comparable abrasion resistance that further improved desulfurization performance by reducing the amount of ultra-fine particles generated from limestone.

Development and Application of an IoT-Based System for Soil Water Status Monitoring in a Soil Profile.

Soil water content (θ), matric potential (h) and hydraulic conductivity (K) are key parameters for hydrological and environmental processes. Several sensors have been developed for measuring soil θ-h-K relationships. The cost of such commercially available sensors may vary over several orders of magnitude. In recent years, some sensors have been designed in the framework of Internet of Things (i.e., IoT) systems to make remote real-time soil data acquisition more straightforward, enabling low-cost field-scale monitoring at high spatio-temporal scales. In this paper, we introduce a new multi-parameter sensor designed for the simultaneous estimation of θ and h at different soil depths and, due to the sensor's specific layout, the soil hydraulic conductivity function via the instantaneous profile method (IPM). Our findings indicate that a second-order polynomial function is the most suitable model (R2 = 0.99) for capturing the behavior of the capacitive-based sensor in estimating θ in the examined soil, which has a silty-loam texture. The effectiveness of low-cost capacitive sensors, coupled with the IPM method, was confirmed as a viable alternative to time domain reflectometry (TDR) probes. Notably, the layout of the sensor makes the IPM method less labor-intensive to implement. The proposed monitoring system consistently demonstrated robust performance throughout extended periods of data acquisition and is highly suitable for ongoing monitoring of soil water status.

Spreading Behavior of Non-Spherical Particles with Reconstructed Shapes Using Discrete Element Method in Additive Manufacturing.

The spreading behavior of particles has a significant impact on the processing quality of additive manufacturing. Compared with spherical metal material, polymer particles are usually non-spherical in shape. However, the effects of particle shape and underlying mechanisms remain unclear. Here, the spreading process of particles with reconstructed shapes (non-spherical particles decomposed into several spherical shapes by stereo-lithography models) are simulated by integrating spherical particles with the discrete element method. The results show that more cavities form in the spreading beds of particles with reconstructed shapes than those of spheres with blade spreading. Correspondingly, particles with reconstructed shapes have lower packing densities, leading to more uniform packing patterns. Slow propagation speeds of velocity and angular velocity lead to "right-upwards" turning boundaries for particles with reconstructed shapes and "right-downwards" turning boundaries for spherical particles. Moreover, as the blade velocity increases, the packing density decreases. Our calculation results verify each other and are in good agreement with the experiment, providing more details of the behavior of non-spherical particles before additive manufacturing. The comprehensive comparison between polymer non-spherical particles and spherical particles helps develop a reasonable map for the appropriate choice of operating parameters in real processes.

Optimization of Discontinuous Polymer Flooding Processes for Offshore Oilfields Using a Novel PSO–ICA Algorithm

Recently, discontinuous polymer flooding has been proposed and successfully applied in some offshore oilfields. The performance of discontinuous polymer flooding depends on various operational parameters, such as injection timing, polymer concentrations, and crosslinker concentrations of four types of chemical slugs. Because the number of the operational parameters are large and they are nonlinearly related, the traditional reservoir numerical simulation might not simultaneously obtain the optimal results of these operational parameters. In this study, to simulate the discontinuous polymer flooding processes, a simulation model was built using a commercial reservoir simulator (CMG STARS), in which the mechanisms of the four types of chemical slugs were considered, such as polymer viscosification, adsorption, and degradation. Then, a PSO–ICA algorithm was developed by using the PSO algorithm to improve the exploration ability of the ICA algorithm. The codes were written with MATLAB and linked to CMG STARS to perform optimization processes. Finally, the PSO–ICA algorithm was compared with the ICA and PSO algorithms on benchmark functions to verify its reliability and applied to optimize a discontinuous polymer flooding process in a typical offshore oilfield in Bohai Bay, China. The results showed that the developed PSO–ICA algorithm had lower iteration numbers, higher optimization accuracy, and faster convergence rate than these of PSO and ICA, indicating that it was an effective method for optimizing the operational parameters of discontinuous polymer flooding processes. Compared to the continuous polymer flooding, the discontinuous polymer flooding had a higher oil production rate, a lower water cut, and a lower residual oil saturation. The net present value of the optimal scheme of discontinuous polymer flooding reached 7.49 × 108 $, which is an increase of 6% over that of the scheme of continuous polymer flooding. More research including selecting more reasonable parameters of the PSO–ICA algorithm to increase its optimization accuracy and convergence rate, comparing with other available optimization algorithms, and verifying the performance of the optimal scheme of discontinuous polymer flooding in the practical offshore oilfield will be required in the future.

Biohydrogen, Volatile Fatty Acids, and Biomethane from Mezcal Vinasses—A Dark Fermentation Process Evaluation

Mezcal is a drink made in Mexico, the production of which generates vinasses with a high content of organic matter (OM) that is not utilized. However, these residues have the potential to be drawn upon in dark fermentation (DF) processes to obtain biogas rich in biohydrogen, biomethane, and volatile fatty acids (VFAs) with the potential to become biofuels. In the present work, the effect of reaction time (RT) and organic load (OL) was assessed based on the efficiency of removing OM, the production of VFAs, and the generation and composition of biogas in a process of DF fed with mezcal vinasses. The results show that increasing the RT and decreasing the OL increases COD removal but decreases biohydrogen production. The maximum production of H2 (64 ± 21 NmL H2/Lreactor) was obtained with the lowest RT (1 d) and the highest OL (13.5 gCODm3d−1), while the highest accumulation of VFAs (2007 ± 327 mg VFA/L) was obtained with an RT of 3 d. It was determined that RT and OL are key parameters in DF processes for biohydrogen and VFA production.

Comparative analysis of the effectiveness of probiotic enterococcus strains in gastroenteritis in piglets

According to a number of authors, a sharp change in the type of feeding and the effects of stress factors in piglets after weaning lead to disorders not only of metabolism, but also of membrane digestion, which further contributes to a decrease in body resistance and the occurrence of various diseases of the digestive organs.In the course of our study, it was found that the use of probiotic strains Enterococcus faecium L-3 and Enterococcus faecium 1-35 for the treatment of gastroenteritis in piglets during weaning had a similar effect on restoring intestinal enzymatic activity. In piglets that were not treated with probiotics (control 1), enzymatic activity in the digestive tract was only partially normalized during the study. We also evaluated some parameters of the ongoing metabolic processes in the body of weaning piglets by studying the biochemical blood parameters of the experimental groups after prescribing the probiotic strain Enterococcus faecium L-3 (experiment 1) and Enterococcus faecium 1-35 (experiment 2) comparing them with those of the control group of animals.

LIQUID NEURAL NETWORKS: PRINCIPLE OF WORK AND AREAS OF APPLICATION

The article deals with the architecture of liquid neural networks (LNN) and their potential in modern technologies. Thanks to the constant development of algorithms and hardware, neural networks are becoming more and more powerful and efficient, which opens up new opportunities for their application. The authors describe the principle of operation of liquid neural networks, which includes the process of learning and inference, which allows effective use of the natural dynamics of the system to solve various tasks, including classification, prediction, and control. We note that the concept of LNNs arose as an attempt to overcome some of the limitations and problems faced by traditional neural networks. The study considers the basic concepts and principles of LNNs and their application potential in various fields, from robotics to medicine and industry. The study also determines the main advantages and disadvantages of LNNs compared to traditional models. It is possible to use them to process a large stream of data, such as video, audio, or sensory data from various sensor types, allowing robots to receive information about their environment and make decisions based on that data. In medical diagnostics and image processing, liquid neural networks can significantly contribute to the quality and efficiency of diagnostic procedures. LNNs can enable the implementation of automatic control systems that monitor and regulate parameters of production processes or adapt to changes in the environment and optimise parameters to achieve maximum productivity and product quality. The field of LNN lacks standards and is limited to using performance metrics. Establishing standards and objective metrics will allow researchers and engineers to understand and compare different LNN implementations. Although LNNs are relatively efficient in terms of power consumption, their implementation at the hardware level may require new technologies and architectures to optimise performance. As a result, the study outlines the prospects for the further development of this technology. Keywords: liquid neural networks, artificial intelligence, adaptive control, learning efficiency, application potential.

THE ALGORITHM OF RISKS IDENTIFICATION IN THE OPERATING MODEL

The main purpose of creating an operational model is to ensure the synchronization of the organization's strategy and operational functions. The algorithm of the operating system can be represented as a hierarchical sequence of optimization processes aimed at achieving the final goal - value chain map. The operating system of an individual organization has its own process and parametric features that distinguish it from others. The risk factors will reflect these differences and the methods of their prediction and compensation should also be adapted to the specifics of the operating systems. It is impossible to optimize the operating model, to ensure the economic stability of the organization, ignoring objective and subjective sources of risks. Exclusion of risk parameters of operational processes directly affects the overall efficiency of the operational system, reduces uncertainty and unwanted fluctuations in the quality indicators of the operational model. The article examines the hierarchical algorithm of risk identification in the operational model of the organization.

CALCULATION OF THE LOGISTICS SYSTEM CENTER OF THE MAGNUM SUPERMARKET CHAIN IN PETROPAVLOVSK

The logistics system of Magnum supermarkets is the largest in Petropavlovsk, therefore the parameters of transport processes in this system have different directions and values, both in time and in space. Improving the efficiency of the transport logistics system is a priority. One of the factors influencing the efficiency of the transport logistics system is the location of warehouses and stores. In this article, the author calculated the center of the logistics system in order to determine the coordinates of the warehouse location in order to reduce transportation costs. For the calculation, the method of determining the center of gravity of the physical model of the distribution system was used. The results of the work are defined in the form of coordinate values. The calculation method can be used in distribution logistics. The data obtained cannot always be applied in practice, so this calculation method must be used together with other methods for determining the location of the warehouse, for example, the test point method.

Process parameter optimization for laser directed energy deposition (LDED) of Ti6Al4V using single-track experiments with small laser spot size

Single-track experiments are routinely used in the optimization of process parameters in additive manufacturing processes. Most of the process parameter optimization studies use a laser spot size of 1 mm or more. Since laser spot size affects the input energy density and in turn the efficiency of the deposition process, it is important to develop process maps every time a laser of different spot sizes is used. In this work, we determine the process maps for a laser of 0.6 mm spot size. By combining the process maps and the metallographic inspection, we estimate the optimum process parameters (laser power, scan speed, powder feed rate) for building Ti6Al4V components using powder-based laser-directed energy deposition(LDED). Single-tracks corresponding to 64 different parameter combinations are deposited. After eliminating the process parameter combinations resulting in defective tracks, the optimum process parameters of 300 W laser power and 720 mm min−1 scan speed is established by considering the relationship between the process parameters and the geometrical features of the deposit. The experimental results are then used to calibrate the modeling parameters of a three-dimensional finite element model for simulating the deposition process.

A past and present perspective on the European summer vapor pressure deficit

Abstract. The response of evapotranspiration to anthropogenic warming is of critical importance for the water and carbon cycle. Contradictory conclusions about evapotranspiration changes are caused primarily by their brevity in time and sparsity in space, as well as the strong influence of internal variability. Here, we present the first gridded reconstruction of the summer (June, July, and August) vapor pressure deficit (VPD) for the past 4 centuries at the European level. This gridded reconstruction is based on 26 European tree ring oxygen isotope records and is obtained using a random forest approach. According to validation scores obtained with the Nash–Sutcliffe model efficiency, our reconstruction is robust over large parts of Europe since 1600, in particular for the westernmost and northernmost regions, where most tree ring records are located. Based on our reconstruction, we show that from the mid-1700s a trend towards higher summer VPD occurred in central Europe and the Mediterranean region that is related to a simultaneous increase in temperature and decrease in precipitation. This increasing summer VPD trend continues throughout the observational period and in recent times. Moreover, our summer VPD reconstruction helps to visualize the local and regional impacts of the current climate change, as well as to minimize statistical uncertainties of historical VPD variability. This paper provides also new insights into the relationship between summer VPD and large-scale atmospheric circulation, and we show that summer VPD has two preferred modes of variability, namely a NW–SE dipole-like mode and a N–S dipole-like mode. Furthermore, the interdisciplinary use of the data should be emphasized, as summer VPD is a crucial parameter for many climatological feedback processes in the Earth's surface system. The reconstructed summer VPD gridded data over the last 400 years are available at the following link: https://doi.org/10.5281/zenodo.5958836 (Balting et al., 2022).

An observational network of ground surface temperature under different land-cover types on the northeastern Qinghai–Tibet Plateau

Abstract. Ground surface temperature (GST), measured at approximately 5 cm in depth, is a key controlling parameter for subsurface biophysical processes at the land–atmosphere boundary. This work presents a valuable dataset of GST observations at various spatial scales in the Headwater Area of the Yellow River (HAYR), a representative area of high-plateau permafrost on the northeastern Qinghai–Tibet Plateau (QTP). GST was measured every 3 h using 72 iButton temperature loggers (DS1922L) at 39 sites from 2019 to 2020. At each site, GST was recorded in two plots at distances from 2 to 16 m under similar and different land-cover conditions (steppe, meadow, swamp meadow, and bare ground). These sensors proved their reliability in harsh environments because there were only 165 biased measurements from a total of 210 816. A high significant correlation (>0.96, p<0.001) was observed between plots, with a mean absolute error (MAE) of 0.2 to 1.2 °C. The daily intra-plot differences in GST were mainly <2 °C for sites with similar land cover in both plots and >2 °C when GST of bare ground was compared to that of sites with vegetation. From autumn to spring, the differences in GST could increase to 4–5 °C for up to 15 d. The values of the frost number (FN) were quite similar between the plots with differences in FN <0.05 for most of the sites. This dataset complements the sparse observations of GST on the QTP and helps to identify the permafrost distribution and degradation at high resolution as well as to validate and calibrate the permafrost distribution models. The datasets are openly available in the National Tibetan Plateau/Third Pole Environment Data Center (https://doi.org/10.11888/Cryos.tpdc.272945, Şerban and Jin, 2022).

Investigating rough single-fracture permeabilities with persistent homology

Abstract. The permeability of rock fractures is a crucial parameter for flow processes in the subsurface. In the last few decades, different methods were developed to investigate on permeability in fractures, such as flow-through experiments, numerical flow simulations, or empirical equations. In recent years, the topological method of persistent homology was also used to estimate the permeability of fracture networks and porous rocks but not for rough single fractures yet. Hence, we apply persistent homology analysis on a decimetre-scale, rough sandstone bedding joint. To investigate the influence of roughness, three different data sets are created to perform the analysis: (1) 200 µm, (2) 100 µm, and (3) 50 µm resolutions. All estimated permeabilities were then compared to values derived by experimental air permeameter measurements and numerical flow simulation. The results reveal that persistent homology analysis is able to estimate the permeability of a single fracture, even if it tends to slightly overestimate permeabilities compared to conventional methods. Previous studies using porous media showed the same overestimation trend. Furthermore, the expenditure of time for persistent homology analysis, as well as air permeameter measurements and numerical flow simulation, was compared, which showed that persistent homology analysis can be also an acceptable alternative method.

Multi-objective optimization of machining parameters in complete peripheral milling process with variable curvature workpieces

The mechanism of peripheral milling with variable curvature has yet to be revealed. There is an urgent need to develop a composite optimization approach for the full milling process, including rough and fine machining. The influence of curvature on the energy consumption mechanism in peripheral milling is investigated in this paper. Firstly, the geometric parameters of peripheral milling are analyzed, and the material removal rate calculation method with variable curvature is proposed. The effects of workpiece curvature, machining parameters, and tool wear on energy consumption and surface quality are revealed. Secondly, prediction models for machine tool specific energy and surface roughness are developed in accordance with the examined material removal mechanism. Then, the carbon emission calculation method for the complete peripheral milling process is put forward based on the developed energy consumption mechanism. Finally, a genetic algorithm with elite strategy is used to optimize the multi-dimensional and multi-objective machining parameters. The objective is to achieve the maximum machining efficiency, minimize carbon emissions, and attain excellent surface quality during the complete milling process. The research aims to concurrently optimize machining parameters for rough and fine machining processes, thereby enabling effective and environmentally friendly peripheral milling while maintaining machining quality. The determination coefficient R2 for the proposed model exceeds 0.97, while the average accuracy of predictions surpasses 96 %. The research holds particular importance in providing guidance for peripheral milling operations involving workpieces with variable curvature.

Scientific substantiation of complex extraction and processing of secondary resources for the development of alternative sources of energy

Scientific research on the integrated extraction and processing of secondary resources, such as mine water, technogenic waste, and others, in order to develop alternative energy sources in the diversification of coal mines is an urgent scientific task that will help solve the issues on the economic, social and environmental transformation of coal mining regions. In practice, it is necessary to consider several alternative options and assess the possibility of obtaining different end products from the targeted processing of secondary raw materials. The choice of a rational processing option to obtain the target product is very complicated due to the different composition of the feedstock, as well as a significant variety of primary processing methods and parameters of intermediate processes, which causes certain difficulties in forecasts and calculations. Developing a methodology for typifying actions when choosing options for integrated processing of recyclable materials of different states, defining the basic principles and its structure for comparative analysis of the input, intermediate, and output parameters in terms of composition, physical, chemical, and technological characteristics are urgent modern tasks.

Effects of Letrozole Treatment and Vitamin C Supplementation on Morphology, Endoplasmic Reticulum Stress, Programmed Cell Death, and Oxidative Stress in the Small Intestine of Adult Male Rats.

Estrogens are hormones that play an important role in the digestive tract, including in men. Letrozole is an inhibitor of cytochrome P450 aromatase, an enzyme converting androgens to estrogens. The use of letrozole may cause oxidative stress and endoplasmic reticulum stress in the cells. Factors modulating cellular stress may include vitamin C. The purpose of this study was to examine whether letrozole and/or vitamin C supplementation can affect the morphology of the small intestine, the parameters of endoplasmic reticulum stress, programmed cell death markers, and oxidative damage. Three-month-old male rats were divided into four groups and treated with the following: (I) CTRL-water; (II) CTRL+C-L-ascorbic acid; (III) LET-letrozole; and (IV) LET+C-letrozole + L-ascorbic acid. The morphometrical measurements included epithelial thickness, crypt and lumen area, crypt perimeter, nuclei number in the crypt, and the cell size of crypts. The expression levels of PERK, caspase-3, and catalase were determined. Significant differences in the morphometrical measurements and immunoexpression were observed. This may indicate that chronic treatment with letrozole can affect morphology and induce ER stress, oxidative stress, and programmed cell death in the epithelial cells of the small intestine of adult male rats. Vitamin C supplementation exerts an effect on some parameters of the molecular processes.