Direct Proportion Research Articles

Investigation of Microstructure and Wear Behaviors of AZ91 Alloy Under Different Heat Treatments

This article aims to experimentally investigate the effect of heat treatment applied to AZ91 magnesium alloys on wear behavior under different applied load conditions. Apart from as-cast AZ91 alloy, AZ91 alloy samples were subjected to both solid-solution treatment (400°C for 16 hours) and three different aging processes (216°C for 4, 8 and, 12 hours) under three different applied loads (10 N, 25 N and, 50 N). Microstructural, characteristic, hardness, friction coefficient, and wear rate behavior under various applied loads were investigated against each other.
 
 The results showed that the wear rate increased in all samples with the applied load, while the friction coefficient decreased. While the highest wear rate was observed only in the solid-solution treated sample, it was observed that the wear rate changed inversely with the aging time. Furthermore, the micro-hardness increased in direct proportion with the aging time. While it was observed that the sample, which was aged for 12 hours, wore 13.6% less under 10 N load than the sample that was only treated with solid-solution, the results showed that the same sample wore about 25% less under 50 N load. The increase in β-precipitates in the structure with the aging period increased the micro-hardness, while the increase in hardness decreased the wear.

Assessment of Outer Space Events on Troposphere and Climate Change over Iraq

The aim of the study is to investigate the effects of space weather on the troposphere, where our climate exists. This work is useful to give us an idea of ​​the interaction between solar activity and some meteorological parameters. The sunspot number (SSN) data were extracted from the World Data Center for the production, preservation, and dissemination of the international sunspot number (SILSO), top net solar radiation (TSR) and temperature 2 meters from the ERA5 model of the Copernicus Climate Change Service (C3S) from the Climate Data Store with 0.25 grid Resolution, providing a rich source of climate data for researchers. This study was conducted from 2008 to 2021 (solar cycle 24 and the beginning of 25) over Iraq located within latitude (38°N-28°S) and longitude (38°W- 49°E). The results that have been reached were a decrease in solar activity in solar cycle 24, accompanied by an increase in the length of the solar cycles, and there was a direct proportion between TSR and temperature. TSR and temperature had almost similar spatial distribution over Iraq. The northern regions received the least amounts, while from the middle toward the southeast regions, they received the highest amount of TSR and temperature over Iraq. There was a reverse regression between sunspot numbers with TSR and positive regression with temperature, but the correlation was not significant.

RAFT emulsion polymerization of methyl methacrylate mediated by protonated poly(2‐(dimethylamino)ethyl methacrylate) macromolecular chain transfer agent: A mechanism study

AbstractSurfactant‐free reversible addition‐fragmentation transfer (RAFT)‐mediated emulsion polymerization has been used in the synthesis of latex particles. Although this method has been developed for some time, some detailed mechanisms are not clear. Herein, RAFT emulsion polymerization of methyl methacrylate (MMA) mediated by protonated poly(2‐(dimethylamino)ethyl methacrylate) (H+‐PDMAEMA) macromolecular chain transfer agent (macro‐CTA) is studied. The effects of the molar ratios of MMA/macro‐CTA and initiator/macro‐CTA, and the macro‐CTA chain length on the emulsion polymerizations are investigated. At the nucleation stage, H+‐PDMAEMA‐CTA is chain extended with MMA dissolved in aqueous phase; and when the length of PMMA block is above a critical length, the formed amphiphilic block copolymer (BCP) chains self‐assemble into micellar particles. The nucleation time in the emulsion polymerization is strongly dependent on the chain length of H+‐PDMAEMA‐CTA, and the molar ratio of free radical initiator/macro‐CTA. The emulsion polymerization rate is in direct proportion to the molar ratio of free radical initiator/macro‐CTA. The size and the size distribution of the latex particles can be tuned through control of the macro‐CTA chain length and MMA/macro‐CTA molar ratio. Monodispersed latex particles can be synthesized under proper conditions. It is expected that well‐defined latex particles with a variety of hydrophilic polymers (or biomacromolecules) on the surfaces can be synthesized by this approach.

Investigation of physical and mechanical properties of nanocarbon black-added lightweight UHPC

The high specific density of concrete significantly increases the dead load in buildings. Using pumice, which is a volcanic material, as an aggregate in concrete decreases the concrete's density. However, pumice causes a decrease in the mechanical properties of concrete owing to its porous structure. The improvement of the mechanical properties of concrete can provide material savings by reducing the cross-sections of the structural elements to be used in buildings. Ultra-high-performance concrete, which has been an important subject of studies in recent years, is an important construction material for civil engineering. In this study, the physical and mechanical properties of lightweight ultra-high-performance concrete (LW-UHPC) with pumice additive were investigated. Nanocarbon black was added to the mixture as 5, 10 and 15% of the cement weight. Significant increases were observed in the mechanical properties of nanocarbon black-added concrete. The addition of nanocarbon black to concrete at a certain ratio increased the compressive strength and flexural strength of concrete by 9.9% and 10.6%, respectively. In addition, it was observed that the sulfate resistance increased in direct proportion to the increase in the amount of nanocarbon black.

Synthesis of Copper/Sulfur Co-Doped TiO2-Carbon Nanofibers as Catalysts for H2 Production via NaBH4 Hydrolysis

Copper/sulfur co-doped titanium dioxide-carbon nanofibers (Cu,S-codoped TiO2 NPs, decorated-CNFs) catalysts were synthesized using the electrospinning process to produce composite nanofibers (NFs). These composite NFs were utilized for the hydrolysis of sodium borohydride (SBH) to generate hydrogen gas (H2), taking advantage of their catalytic properties. The experimental results demonstrated that using 100 mg of composite NFs yielded the highest catalytic activity for H2 production, generating 79 mL of H2 gas within 6 min at 25 °C and 1000 revolutions per minute (rpm) using 1 mmol of SBH. As the catalyst dosage was reduced from 100 mg to 75, 50, and 25 mg, the reaction time increased by 9, 13, and 18 min, respectively. Kinetic studies revealed that the reaction rate followed a first-order reaction, indicating a direct proportionality between the rate of reaction and the catalyst amount. Additionally, it was observed that the concentration of SBH had no influence on the reaction rate, suggesting a zero-order reaction. Increasing the reaction temperature resulted in a reduced reaction time. The activation energy was determined to be 26.16 kJ mol−1. The composite NFs maintained their superior performance over five iterations. These findings suggest that composite nanofibers have the potential to serve as a cost-effective alternative to expensive catalysts in hydrogen production.

The Effect of Principal’s Leadership and Infrastructure Support on Teacher’s Performance

Leadership is a birth from a protracted process of change in a person rather than a position or title. Teacher performance is always the center of attention because it is one of the factors in improving student achievement, so that teacher performance is always considered and various efforts are made to improve teacher performance. The infrastructure resources that Gunung Raja District schools have to support the educational process are insufficient to assist teachers in their instruction and prevent the development of students’ knowledge and abilities. The researcher is motivated to study "The Influence of Principal Leadership and Infrastructure Support on the Performance of Public Elementary School Teachers in Tanjung Raja District" in light of these circumstances. The survey research approach was employed in this study. 262 instructors, including the principals of 26 public primary schools in the Tanjung Raja District, made up the study’s population. Out of a total population of 262 respondents in 26 public elementary schools in Tanjung Raja District, the researchers selected 144 participants In this research, the technique and data collection that researchers use is through questionnaires, observation, and documentation. The conclusions: The effectiveness of the teachers is significantly influenced by the head of the school’s leadership. The performance of the teachers improves in direct proportion to the amount of leadership exercised by school administrators. The infrastructure has a considerable impact on the caliber of instructor performance. The quality of the school’s infrastructure and its infrastructure infrastructure will affect the teacher’s performance. Infrastructure has significantly and significantly impacted the principle of the school’s leadership.

Employee Performance and Work Motivation

This study aims to investigate the effects of work discipline and motivation on the output of KFC Bandung employees. The descriptive quantitative method is used in this investigation. The results of the aforementioned study indicate that employee performance at KFC Bandung is positively impacted by job motivation. Despite the fact that great performance may aid an organisation in achieving its objectives. At KFC Bandung, employee performance is significantly impacted by job satisfaction. This illustrates that an employee's performance improves in direct proportion to their level of job discipline. Workplace rules seldom ever have an impact on how well employees at KFC Bandung perform. When employees lack discipline, businesses find it difficult to achieve perfect results. Discipline fosters a strong work ethic since it moulds employees' personalities.

An Investigation of the Relationship between Fingerprints and Anaerobic Powers of Sports Sciences Students

In this study, the relationship between fingerprints and the anaerobic power of athletes was analyzed in a random sample group in correlation type. Fingerprints have been used electronically for identification in forensic criminology and authentication in business and social life with the development of dermatoglyphics science in the last century and the understanding that fingerprints are unique to the individual. Today, it is known that much research is being carried out to determine genetic characteristics, heredity, gender, character, and ability analysis from fingerprints. In this study, the height and weight measurements of 126 athletes from Cumhuriyet University Faculty of Sports Sciences were taken with the appropriate sampling method, and the vertical jump test was applied to the individuals. The anaerobic power of the athletes was calculated with these collected data. The coding method determined 10 fingerprints of the same sample group, and fingerprint classes and attributes were determined by observation. According to the findings obtained from the data analysis, a significant difference was observed between the anaerobic powers of the athletes according to their fingerprint classes. The anaerobic power of athletes with W2 Normal fingerprint codes has been observed to be higher than those without W2. However, it has been observed that fingerprints in certain codes increase and decrease in direct proportion to anaerobic power. In light of the data obtained in this study, limited but meaningful data were obtained in the direction of detecting sportive skills from fingerprints.

Optimization of Machining Parameters to Minimize Cutting Forces and Surface Roughness in Micro-Milling of Mg13Sn Alloy.

This comprehensive study investigates the micro-milling of a Mg13Sn alloy, a material of considerable interest in various high-precision applications, such as biomedical implants. The main objective of the study was to explore the optimizations of variable feed per tooth (fz), cutting speed (Vc), and depth of cut (ap) parameters on the key outcomes of the micro-milling process. A unique experimental setup was employed, employing a spindle capable of achieving up to 60,000 revolutions per minute. Additionally, the study leveraged linear slides backed by micro-step motors to facilitate precise axis movements, thereby maintaining a resolution accuracy of 0.1 μm. Cutting forces were accurately captured by a mini dynamometer and subsequently evaluated based on the peak to valley values for Fx (tangential force) and Fy (feed force). The study results revealed a clear and complex interplay between the varied cutting parameters and their subsequent impacts on the cutting forces and surface roughness. An increase in feed rate and depth of cut significantly increased the cutting forces. However, the cutting forces were found to decrease noticeably with the elevation of cutting speed. Intriguingly, the tangential force (Fx) was consistently higher than the feed force (Fy). Simultaneously, the study determined that the surface roughness, denoted by Sa values, increased in direct proportion to the feed rate. It was also found that the Sa surface roughness values decreased with the increase in cutting speed. This study recommends a parameter combination of fz = 5 µm/tooth feed rate, Vc = 62.8 m/min cutting speed, and ap = 400 µm depth of cut to maintain a Sa surface roughness value of less than 1 µm while ensuring an optimal material removal rate and machining time. The results derived from this study offer vital insights into the micro-milling of Mg13Sn alloys and contribute to the current body of knowledge on the topic.

Magnetic string matter collapse in rainbow gravity

This work investigates the dynamics of a collapsing magnetic string dust and string fluid in the Plank Era via spherically symmetric rainbow geometry. The field equations are modified and solved to obtain the dynamical quantities, including mass density, pressure, string tension, and magnetic field strength. These quantities are presented graphically. The energy conditions are computed showing that all the dynamical quantities are associated with physical matter. The distance and moment of apparent horizon formation are computed. The magnetic field is found to affect the distance and moment of the apparent horizon’s formation. It accelerates the collapsing process. Further, the dynamical variables are maximum in the collapsing configuration’s center leading to compact object (black hole) formation. The probing particle’s energy affects all the dynamical variables of the fluid in a direct proportion. This resolves the information paradox as a particle with greater energy grasps the information from a particle with lesser energy and takes it out in the real world.

Xanthophyll pigments dietary supplements administration and retinal health in the context of increasing life expectancy trend.

Medicine faces nowadays the trend of increasing life expectancy of human population, with the resulting increase of degenerative age related diseases prevalence, combined with the risks of less tempered sun radiations environment exposure. Under these circumstances, our work pointed out on evaluating the effect of some xanthophyll pigments dietary supplements, actually widely recommended, for prevention of retinal degenerative damages and for slowing down the progression of such age related changes if they have already occurred. These dietary supplements are already well known for their total antioxidant activity, proven by photochemiluminescence method using Total Antioxidant Capacity in Lipid soluble-substances procedure. The study recruited a number of 120 subjects equally divided on genders. The lot included a first group of 60 patients with comparable ages (all of them over 50 years and divided in 2 segments of age: 50-60 and over 60) and suffering from comparable retinal age-related degenerative abnormalities (mild/medium severity age-related macular degeneration according to Wisconsin Age-Related Maculopathy Grading System), and a second group, considered control, including a similar number of healthy, normal retina subjects belonging to same age and gender categories. There were evaluated at baseline the eye medical status and the retinal risk by specific methods: complete eye check-up, Amsler grid, specific standardized questionnaires focused on visual function and its impact on the quality of current life. Both groups, patients and control, received similar dosages of xanthophyll pigments dietary supplements including lutein and zeaxanthin during 18 months after baseline; at the end of this supplementation period a new evaluation was conducted. In the second part of the research all subjects involved received a new dietary supplement in which the same xanthophylls were enriched with C and E vitamins and oligo-elements Zinc and Copper. At the end of three years duration supplementation, the subjects were reevaluated and the paper presents the conclusions on the matter, pointing on the impact of xanthophyll supplements on visual health. Correlation tests were applied to the complete set of data. Correlation tests have values between -1 and +1. The value -1 represents the negative correlation (reverse proportionality) meanwhile the value +1 represents the positive correlation (direct proportionality). The charts show the curves that are fitting experimental data. The dependence is linear in nature, and the value R2, as it approaches more the value 1, represents a better match with the experimental data (the data are in a percentage of approximately 99% on these straight lines of type y = ax + b). In the charts, there were noted the average values of the scores for healthy control patients with "Control", and the average values of the scores for the patients with existing age related degenerative retinal pathology at baseline with "Patients". The retinal function and the impact of visual condition on health were both evaluated at baseline, 18 months and 36 months after baseline, by visual acuity, ophthalmoscopy fundus examination, Amsler test and by asking the subjects to answer the visual function questionnaires: EQ-5D, NEI-VFQ-25, as measures of health status quality and of the influence on welfare. The study revealed that under supplementation both control healthy subjects and patients with known degenerative retinal pathology included in the 50-60 years of age group evolved almost the same way, leading to the conclusion that administered xanthophyll pigments-based supplements, simple or enriched, managed to slow down the progression of abnormal degenerative vision loss to a rate comparable to physiological aging-related vision loss. It was also observed that intake of xanthophyll pigments dietary supplements preserved the general health condition and maintained relatively constant vision on the entire 36th months follow-up research duration in patients presented with existing age related degenerative retinal pathology at baseline. For healthy subjects, evaluation showed an improvement in results after dietary supplementation, with maintenance of constant vision and a significantly increase of general condition, in a positive sense. For subjects over the age of 60 dietary supplements intake was even more effective compared to younger group in providing better control of degenerative processes.

CONTEMPORARY PROBLEMS OF TECHNOLOGICAL RISKS AND THE WAYS OF DEVELOPMENT

The article ‘’Contemporary problems of technological risks and ways of development ‘’ describes the role of technical risks in the economy of Georgia and the search for ways of its development. The problems that stand in this direction are mentioned. Today, in the era of technologies, the degree of technical risks increases in direct proportion of the development of technologies, which has become a heavy burden for users. Today, each of us uses plastic cards or simply has an account in some social network, and all this automatically puts us at technological risk. Therefore, the most frequently discussed issue is precisely the technical risks and possible serve consequences caused by them. Electronic commerce and internet banking are also noteworthy as the object of attack. Thus, we think that the topic is relevant. The paper discusses the changes that have been made to mitigate these risks. The results of the research are given, the analysis of which gives an idea of the quality of the existing technological risks and ways of elimination. The problems that prevent the better development of technological risks throughout the country are mentioned: 1. Lack of support from the government. 2. Unqualified staff. 3. Inadequate legislation in terms of cyber security. 4. Inadequate insurance of cyber risks. The article presents the results of survey conducted within the framework of the study and relevant statistics. 1. The government should find more support for people affected by technological risks. 2. Specialists employed in the field should be retrained. 3. Legislation should be refined and become victim-friendly. 4. Improve cyber security insurance. Taking all this into account will help’ to solve the problems in technological risks throughout the country. The article contains the opinions ad advice of the authors, seen from the point of view of scientists and its implementation in practice will help to effectively conduct the activities of the filed. Keywords: Technological risks. Cyber security. Economy. Plastic cards. Government. Insurance.

The Inflammatory Profile Correlates with COVID-19 Severity and Mortality in Cancer Patients.

The correlation of the inflammatory profile with the severity of the disease in neoplastic patients with SARS-CoV-2 infection was addressed. A database of 1537 patients hospitalized in the pneumology department was analyzed. After applying the inclusion and exclusion criteria, 83 patients (67% males, 33% females) were included. Most of the analyzed patients were hospitalized with a moderate form of disease, explaining the significant percentage of 25% mortality. The frequency of the type of neoplasm was higher for lung cancer, followed by malignant colon tumor. We identified a significant association between the increased value of ferritin (p < 0.0001, OR = 22.31), fibrinogen (p = 0.009, OR = 13.41), and C-reactive protein (p = 0.01, OR = 7.65), respectively, and the level of severity of COVID-19. The results of the univariate logistic regression analysis for predicting the severity of the disease revealed that the increased values of ferritin (p = 0.001, OR = 22.31) and fibrinogen (p = 0.02, OR = 13.41) represent a risk for a serious negative prognosis of COVID-19. Our study demonstrated that the value of the analyzed inflammatory parameters increased in direct proportion to the severity of the disease and that higher values were associated with increased mortality in the study group.

Structural Strengthening of Insufficiently Designed Reinforced Concrete T-Beams using CFRP Composites

This study aims to compare the response of reinforced concrete (RC) T-beams strengthened with carbon fibre-reinforced polymer (CFRP) composite with that of non-strengthened control beams when subjected to monotonic two-point loading until failure for flexural once and shear again. The experimental programme tested eight RC T-beams, which included two reference beams without strengthening and six strengthened beams. The eight beams were divided into two main groups according to strengthening (flexural and shear). Experimental analysis was performed to study the effect of the CFRP laminate width in the flexural group and the spacing of CFRP U-wrap sheets in the shear group on the ultimate load capacity, load-strain relationship, and load-deflection relationship. Results show that increasing the width of the CFRP laminate in the flexural group improves the ultimate strengths to approximately 9.5%, 35%, and 41% for beams with CFRP laminate widths of 50, 100, and 150 mm, respectively, compared with the reference non-strengthened beam. The stiffness of the beams increases in direct proportion to the width of the CFRP laminate. In the meantime, decreasing the spacing of the CFRP laminate in the shear group increases the ultimate strengths to approximately 13.2%, 17.7%, and 23.5% for beams with CFRP U-wrap sheet spacings of 166, 125, and 100 mm, respectively, compared with the reference non-strengthened beam. Therefore, the spacing of the CFRP sheet is inversely proportional to the stiffness of the beam. Doi: 10.28991/CEJ-2023-09-08-05 Full Text: PDF

Media Narrative: On the Question of Structure and Functions

As a research task, the authors made an attempt to analyze the phenomenon of the media narrative in the structural and functional aspect. The selected research material includes the following phenomena: Soviet posters, publications in the mass media (MSK) and videos (motivational content) posted on the TikTok platform. The subject side of the study includes narrative motifs presented in the relevant materials. The relevance of this scientific research is due to the fact that the media narrative has a large "manipulating resource" and can affect the individual or society. The manipulative "power" of the media narrative is increasing in direct proportion to the development of information technologies in modern society. The research methodology is based on the narrative theory of V. Ya. Propp, which involves the decomposition of the plot into composite invariant motifs. The analysis showed that the motive of struggle in the studied media narratives is the key one, it is repeated in all plot constructions - from the narrative of the Soviet poster to modern narrative forms. The importance of this motive is explained by the fact that it is associated with the goals of media exposure, and the recipients begin to reproduce the motives from the materials studied by the authors in reality. That is, we can say that the audience, consuming information containing this kind of media narrative, begins to become a part of it itself, but in reality.

Freeway capacity modeling and analysis for traffic mixed with human-driven and connected automated vehicles considering driver behavior characteristics

Future freeway traffic flow will include both Human-driven Vehicles (HV) and various sizes of Connected Automated Vehicles (CAV) platoons. When following CAV platoons, HV drivers may change the car-following distance for psychological reasons, which could further affect the road capacity under mixed traffic flow. In this paper, we constructed a capacity model that considered the spatial distribution characteristics of mixed traffic flow and the behavioral traits of HV drivers when they follow CAV platoons. We surveyed 331 HV drivers using a questionnaire. 51.1% of drivers opted to increase the car-following distance when following a CAV platoon, and the amount of change in distance increased in direct proportion to the size of the platoon. A Structural Equation Model (SEM) based on survey data was developed to examine the connection between psychological variables and HV drivers’ driving behaviors. These results of the questionnaire were introduced into the capacity model construction, and the trends of capacity with CAV penetration, maximum platoon size, platoon intensity, and time headways were revealed. The results show that previous studies overestimated the capacity under mixed traffic flow, especially when the maximum platoon size is equal to or greater than 6 or the CAV penetration is between [0.6, 0.8], the overestimation of the capacity is higher. CAV penetration, maximum platoon size, and platoon intensity are positively correlated with capacity, while time headway is negatively correlated with capacity. The capacity growth is not significant when CAV penetration is between (0, 0.4]. Six is the ideal size of CAV platoons under mixed traffic flow when considering the impact of CAV platoons on HV drivers’ driving behaviors. By taking measures to promote CAV aggregation and making platoon intensity greater than 0, the capacity will be improved more significantly. For a specific car-following type, a different value of time headway will lead to a different capacity, but the impact trends will be similar.

Analysis of interfacial de-bonding failure on stiffened composite panel

orThis article aimed at the interfacial de-bonding between the stringer and skin when the structure is under post-buckling loads. A four-point bending test was set up, and the cohesive zone model (CZM) was employed considering the effects of through-thickness compression on the inter-laminar shear failure of composite laminates. The numerical result is in good agreement with the experimental one. The results indicate that: embedded defect at the flange/skin interface has a slight influence on the load capacity of the structure, but embedded defect at the flange/radius-filler interface has a significant influence on the load capacity of the structure, and delamination always initiated at the flange/radius-filler interface. The presence of inner corner defects in the filled area has a greater impact on the load capacity of the structure, the load capacity is in direct proportion to the width of corner defects.

Study on the Regulation Mechanism of Quality Deterioration Due to Chilling Stress and Dry Exposure during Anhydrous Storage and Transportation of Yesso Scallop Patinopecten yessoensis.

In this paper, the quality change of Yesso scallop (Patinopecten yessoensis) in the process of anhydrous storage and transportation after cold acclimation and induced dormancy was studied, and the regulation mechanism of quality degradation during storage and transportation in the process of gradient chilling stress and drying exposure was further explored. The results show that, when transferred from hydrous to anhydrous states, the breathing pattern of the scallops changed from aerobic to anaerobic. Their gill filaments were altered and their apparent vitality constantly declined, which was reflected by the edge shrinkage of the pallium and the direct proportions of the edge reduction rate and the stimulus response period. After being in the anhydrous state for 4 d, the AEC value dropped to 67.59%. At this time, if they were placed under hydration again, the scallops resumed a good growth state. By proteomics analysis, it was revealed that cold acclimation and dry exposure mainly led to changes in biological functions and pathways, such as mitochondrial inner membrane and ATP hydrolysis activity. In addition, it can be seen from the functional annotation and enrichment analysis of the metabolite KEGG that cold acclimation promoted the purine metabolism of scallops, while dry exposure inhibited the metabolism of saturated fatty acids. In this study, the infrared sensing mode was used for the first time, too, in order to record the heart-rate changes of the scallops during circulation, which shows that non-destructive vitality monitoring of Lamellibranchia is feasible.

Experimental Study on Axial Compressive Performance of Light-Steel Skeleton–Cement–Fly Ash Foam Wallboard

Foamed cement fly ash is a new type of lightweight construction material that can be combined with a light steel frame to form light-steel skeleton–cement–fly ash foam wallboard (LSSCFAFW). The research on the axial compressive performance of light steel and light concrete composite wallboard is relatively limited. Four pieces of LSSCFAFWs were manufactured, and the impact of stand column quantity and various filler parameters on the LSSCFAFW was investigated. The failure mode of the wallboard and the influence of different parameter variables on its axial compressive performance were obtained through experiments. Moreover, the test results indicated essentially the same damage patterns in terms of stand-column buckling, filler crushing, and self-tapping screw failure. The addition of polypropylene fiber to this wallboard can prevent filler from falling off. The axial compressive performance of the LSSCFAFW demonstrates a direct proportion with the number of columns and cement content, improving as the number of stand columns and the cement content increase. However, the addition of polypropylene fiber to the filler has a minimal effect on the axial compressive performance of this wallboard. Compared to the control group, increasing the number of stand columns, adding 0.4% polypropylene fibers, and increasing the cement dosage to 50% improved the ultimate bearing capacity of the wallboards by 12%, 8%, and 56% respectively. The result of this study can provide references for the research and application of light steel frame to form LSSCFAFW.

Impact Assessment of the Chirp Signal Frequency Change Rate on the Energy Secrecy and Noise Immunity

The article deals with the issues of noise immunity and energy secrecy of chirp signals. The purpose of the article is to study the rate of chirp signal frequency change and its influence on signal parameters, such as the envelope and spectrum of the signal, the degree of its energy secrecy and noise immunity. A study was made of the chirp signal frequency change rate influence on the amplitude spectrum of the transmitted signal. The study showed that an increase in the chirp signal frequency change rate leads to an increase in the slope control of the sawtooth voltage. In this case, the width of the amplitude spectrum changes in direct proportion to the change in the frequency band. Based on the results, the assumption was made about the positive effect of increasing the slope of the control signal on noise immunity and energy secrecy. The effect of the chirp signal frequency change rate on the degree of energy secrecy is studied by means of the author's method to estimate the energy of the transmitted symbol. The simulation results showed that the rate of change in the frequency of the chirp signal does not lead to a change in energy and does not affect the degree of energy secrecy. A study was made of the chirp signal frequency change rate influence on the noise immunity of the transmitted signal. It was proposed to investigate a real high-frequency chirp signal using the weighting method on a set of matched filters. The method made it possible to investigate the noise immunity of chirp signals with different parameters and compare the obtained data with the noise immunity of the GMSK signal of the Gonets-M satellite communication system. As a result, some regularities were found that allow us to evaluate the effect of the rate of change in the frequency of the chirp signal on its noise immunity. Comparison of GMSK and chirp signals made it possible to verify the effect of introducing chirp signals into satellite communication systems. As a result of the study, conclusions were drawn about the influence of the choice of chirp signal frequency change rate on noise immunity and energy secrecy.