Total Penetration Research Articles

Current Situation, Problems and Suggestions of Agricultural Futures Market in China

The agricultural futures market occupies a central position in China's financial landscape, wielding substantial influence over the sustainable development of the national economy. Apart from its core roles in price discovery and risk management for agricultural products, this market acts as a catalyst for efficient allocation of resources and continuous financial innovation. Furthermore, it enhances market liquidity and amplifies China's global economic impact. As China's financial sector matures, the agricultural futures market will continue its dual role of bolstering agricultural prosperity and financial dynamism, despite encountering various challenges. This study explores the present state of China's agricultural futures market, evaluating metrics such as total market turnover and penetration. Analysis identifies several critical issues, including inadequate liquidity, susceptibility to market manipulation, speculative activities, and uncertain economic policies. To address these challenges, the paper proposes targeted strategies. The research outcomes carry significant implications for nurturing the sustainable and resilient growth of China's agricultural futures market.

Incubating frozen-thawed buffalo sperm with olive fruit extracts counteracts thawing-induced oxidative stress and improves semen quality

Freezing-thawing procedures and semen manipulation for in vitro fertilization induce oxidative stress, which in turn leads to impaired sperm quality. The aim of this study was to evaluate whether incubation of frozen-thawed buffalo semen with olive fruit extracts (OFE), known to contain a high concentration of phenolic antioxidants, would improve semen quality by reducing oxidative stress.Frozen sperm (4 ejaculates/4 bulls/3 replicates) were thawed and diluted to 30 × 106/mL in IVF medium with 0, 72, 143, and 214 μL/mL of OFE, corresponding to 0 (D0-control), 50 (D50), 100 (D100), and 150 (D150) μM hydroxytyrosol. Sperm viability, acrosome integrity, membrane functionality, motility, and sperm kinetics were evaluated immediately after thawing (T0) and after 1 (T1) and 2 h (T2) of incubation at 38.7 °C. Based on the results, sperm biological antioxidant potential (BAP) and ROS levels (ROMs) were assessed in D0 and D100 groups at T1 and T2. To assess the effect of OFE on fertilizing ability, heterologous penetration rates were also evaluated, using bovine abattoir-derived oocytes.The treatment with OFE at all concentrations tested increased (P < 0.05) the percentage of acrosome intact spermatozoa compared to the D0-control at T1, but the effect was more evident (P < 0.01) with D100 (54.5 ± 3.0, 60.5 ± 1.5, 65.2 ± 3.3, and 62.5 ± 1.7, with D0, D50, D100, and D150 OFE, respectively). Total motility, progressive motility, rapid velocity, and progressive velocity decreased (P < 0.05) at T2 only in the D0-control group. The percentage of rapidly progressive sperm and the progressive motility tended to increase (P < 0.10) at T1 and T2, respectively, in D100 compared to D0 (24.7 ± 4.1 vs 16.4 ± 1.6 and 22.8 ± 2.7 vs 17.0 ± 1.2, respectively). The treatment with D100 OFE of frozen-thawed sperm increased (P < 0.05) some kinetic parameters (VAP and WOB). Spermatozoa incubated with D100 OFE exhibited higher (P < 0.01) total and normospermic oocyte penetration rates compared to D0 (86.5 ± 1.4 vs 78.5 ± 0.7, and 70.6 ± 1.5 vs 63.8 ± 1.1, respectively). Additionally, D100 OFE increased sperm BAP concentrations at both T1 and T2, while ROS levels were unaffected. These results suggest that incubating frozen-thawed buffalo semen with OFE is an effective strategy for preserving semen quality and in vitro fertilization ability by enhancing sperm antioxidant capacity.

INFLUENCE OF MANUFACTURING CHARACTERISTICS OF HIGHLY CROSS-LINKED POLYETHYLENE ON FEMORAL HEAD PENETRATION IN TOTAL HIP ARTHROPLASTY: A TEN- TO 20-YEAR FOLLOW-UP STUDY

Highly cross-linked polyethylene (HXLPE) has decreased wear and revision rates in total hip replacement (THR) at a long-term. However, the effect of HXLPE manufacturing characteristics on femoral head penetration has not been clearly defined yet. We report this single-institution study to investigate the clinical and radiological results of different HXLPE liners in THR.In this retrospective cohort analysis of our prospective database, we identified 904 THRs performed between 2000 and 2013. Seven different HXLPE liner types were assessed: remelted (3), annealed (2), sequentially annealed (1) and vitamin E-infused (1). The linear femoral head penetration rate was measured at six weeks, one year, and annually thereafter, using the Roman Software v1.70 package.Thirty hips were revised for the following reasons: aseptic loosening (11), dislocation (12), periprosthetic femoral fracture (6), and infection (1). No hip was revised for wear or osteolysis. 741 THRs were evaluated for a mean follow-up of 15 years (range, 10 to 20). The mean total penetration 15 years after THR was 0.17 mm in the sequentially annealed, and 0.16 mm in the vitamin E-infused groups, whereas it was 0.26 mm in the melted 95 kGy, 0.27 mm in the melted 5 Mrad and 0.25 mm in the melted 100 kGy groups (p=0.001). From one to 15 years after surgery, the mean wear was 0.206 mm in cups with an acetabular inclination greater than 50º and 0.105 mm in those placed between 35º and 50º (p&lt;0.001).Although HXLPE characteristics can result in a different wear performance in patients undergoing THR at a mean follow-up of 15 years, the clinical results are excellent. The position of the acetabular component can influence on the femoral head penetration of modern HXLPEs. Nevertheless, these patients should continue to be monitored to detect future problems.

Microbiological and Molecular Investigation of Antimicrobial Resistance in Staphylococcus aureus Isolates from Western Romanian Dairy Farms: An Epidemiological Approach.

Antimicrobial therapy is the most frequently used medical intervention for bovine mastitis in the dairy industry. This study aims to monitor the extent of the antimicrobial resistance (AMR) problem in Staphylococcus aureus in the dairy industry in Western Romania. Twenty farms were selected by random sampling in a transverse epidemiological study conducted across four counties in Western Romania and divided into livestock units. This study assessed the association between the resistance genes to phenotypic expression of resistance and susceptibility. Isolates of S. aureus were identified and q-PCR reactions were used to detect antibiotic resistance genes. One hundred and fifty bovine and 20 human samples were positive for S. aureus. Twenty five percent of bovine isolates (30/120) and none(0/30) of the human isolates were methicillin-resistant S. aureus (MRSA). All isolates were susceptible to fosfomycin, ciprofloxacin, netilmicin, and resistant to ampicillin and penicillin. S. aureus isolates regarded as phenotypically resistant (R) were influenced by the origin of the samples (human versus bovine, χ2 = 36.510, p = 0.013), whether they were methicillin-resistant S. aureus (χ2 = 108.891, p < 0.000), the county (χ2 = 103.282, p < 0.000) and farm of isolation (χ2 = 740.841, p < 0.000), but not by the size of the farm (χ2 = 65.036, p = 0.306). The multiple antibiotic resistance index was calculated for each sample as the number regarded as phenotypically resistant (R)/total antibiotics tested (MARI = 0.590 ± 0.023) was significantly higher (p < 0.000) inmethicillin-resistant S. aureus (0.898 ± 0.019) than non-methicillin-resistant S. aureus (0.524 ± 0.024) isolates. For the antibiotics tested, the total penetrance (P%) of the resistance genes was 59%, 83% for blaZ, 56% for cfr, 50% for erm(B), 53% for erm(C), 57% for mecA and 32% for tet(K). Penetrance can be used as a parameter for guidance towards a more accurate targeting of chemotherapy. P% in S. aureus was strongly positively correlated with the multiple antibiotic resistance index (r = +0.878, p < 0.000) with the potential to use the same limit value as an antibiotic management decision criterion. Considering cow mastitis, the penetrance value combined with the multiple antibiotic resistance index suggests that penetrance could serve as a useful parameter for more precise targeting of chemotherapy for S. aureus.

FOREST HARVESTING: HOW MACHINE TRAFFIC CAN AFFECT SOIL COMPACTION VARIABILITY

The forestry sector has seen an increase in wood demand in recent years, requiring greater mechanization and sustainability in forestry operations, operational excellence, and productivity of stands. The effect of harvesting machine traffic on the soil alters its physical properties, causing degradation, soil compaction, and reducing the volumes of wood produced by commercial forests. Thus, the objective of the present study was to evaluate the spatial variability of soil physical attributes after harvesting and skidding operations, carried out by a harvester and forwarder respectively, in a commercial eucalyptus plantation. The study was conducted in two areas in the municipalities of Itanagra-BA and Entre Rios-BA. Samples were collected in three layers (0-0.20 m; 0.20–0.40 m; 0.40–0.60 m) and the following items were evaluated: total porosity, bulk density, and soil penetration resistance. Operations performed by the harvester and forwarder altered soil resistance, with a greater effect on sandy loam soils, decreasing their density and porosity. Regarding the number of forwarder passes, the seventh pass generated the peak resistance, altering soil recovery capacity, causing additional compaction. Operational planning, to reduce the effects of compaction in areas most susceptible to physical soil degradation, is essential in the forestry area, especially when moisture values are high, a factor that favors soil compaction and reduces stand productivity.

Low-velocity impact responses and failure of sandwich structure with carbon fiber composite honeycomb cores

The objective of this study is to examine the response and failure of honeycomb sandwich structures made of carbon fiber reinforced polymer (CFRP) composites under low-velocity impacts. Four impact tests with varying energies are performed to induce four distinct damage states in the sandwich structure: no discernible damage, damage to the top face sheet and a portion of the core, damage to the lower face sheet, and total penetration. The damage characteristics of the sandwich structures is analyzed by using industrial tomography technology (CT) without destroying them. A refined finite element model is established to further explain the deformation behavior and energy absorption mechanism of the structure, clarifying the effects of the honeycomb core's structural parameters, such as wall thickness, cell side length, and core height. To enhance the precision of simulation outcomes, a model for the onset and progression of damage in plain woven composites is incorporated into the user-defined material subroutine. The experiments and simulations demonstrate a high level of consistency in terms of peak loads, failure mode, and energy absorption.

Interaction of Mechanical Characteristics in Workpiece Subsurface Layers with Drilling Process Energy Characteristics

The performance properties of various types of parts are predominantly determined by the subsurface layer forming methods of these parts. In this regard, cutting processes, which are the final stage in the manufacturing process of these parts and, of course, their subsurface layers, play a critical role in the formation of the performance properties of these parts. Such cutting processes undoubtedly include the drilling process, the effect of which on the mechanical characteristics of the drill holes subsurface layers is evaluated in this study. This effect was evaluated by analyzing the coincidence of the energy characteristics of the short hole drilling process with the mechanical characteristics of the drilled holes’ subsurface layers. The energy characteristics of the short-hole drilling process were the total drilling power and the cutting work in the tertiary cutting zone, which is predominantly responsible for the generation of mechanical characteristics in the subsurface layers. As mechanical characteristics of the drill holes’ subsurface layers were used, the microhardness of machined surfaces and total indenter penetration work determined by the instrumented nanoindentation method, as well as maximal indenter penetration depth, were determined by the sclerometry method. Through an analysis of the coincidence between the energy characteristics of the drilling process and the mechanical characteristics of the subsurface layers, patterns of the effect of drilling process modes, drill feed, and cutting speed, which essentially determine these energy characteristics, on the studied mechanical characteristics have been established. At the same time, the increase in the energy characteristics of the short-hole drilling process leads to a decrease in the total indenter penetration work and the maximum indenter penetration depth simultaneously with an increase in the microhardness of the drilled holes’ subsurface layers.

Towards economic growth in Sub-Saharan Africa: is there a synergy between insurance market development and ICT diffusion?

ABSTRACT This study contributes to the literature by investigating the intervening role of information and communication technology (ICT) diffusion on insurance and economic growth in Sub-Saharan Africa (SSA). This study uses the generalized method of moments technique based on 36 countries, spanning 2007–2020. First, the empirical findings reveal that insurance penetration (i.e. total, life and nonlife) and ICT diffusion induce economic growth in SSA. Second, the evidence suggests that ICT boosts the role of insurance in affecting economic growth. Third, the individual ICT variables such as fixed broadband, telephone and internet propel the impact of total and life penetration on growth. Additionally, fixed broadband was remarkable in enhancing the effect of nonlife penetration on growth. The findings imply that though insurance enhances economic growth, its impact is more revealing through the intervening role of ICT infrastructure. Therefore, insurers must embrace technology and leverage ICT development to improve their performance on growth.

Effect of Biochar on NO3--N Transport in Loessial Soil and Its Simulation

The objective of this study was to explore the effects of different amounts of biochar on the migration process and characteristics of NO3--N in loessial soil. In this study, six groups of mixed soil samples with biochar and loessial soil mass ratios of 0% (T0), 1% (T1), 2% (T2), 3% (T3), 4% (T4), and 5% (T5) were used as research objects. NO3--N was used as the tracer. Through the indoor soil column solute transport simulation tests, the effects of different biochar application amounts on the NO3--N transport process in loessial soil were simulated and studied. The results showed that the breakthrough curve of NO3--N in loessial soil shifted to the right with the increasing of biochar application, and the peak value gradually decreased. The initial penetration time, complete penetration time, and total penetration time increased with the increasing of biochar application amount. The total penetration time of NO3- in the T1, T2, T3, T4, and T5 treatments was 1.26, 2.31, 2.72, 3.22, and 3.57 times that of T0, respectively. The R2 was &gt; 0.997 and RMSE was &lt; 2.083 of the two-zone model (TRM). Compared with the convection-dispersion equation (CDE), the TRM model had higher fitting accuracy and could better simulate the NO3--N migration process in loessial soil after the application of different contents of biochar. The analysis of the fitting parameters of the TRM model showed that the average pore velocity, hydrodynamic dispersion coefficient, and water content ratio in the movable zone gradually decreased with the increasing of biochar application, whereas the dispersion and mass exchange coefficient showed an increasing trend. The results showed that biochar application could effectively enhance the ability of loessial soil to fix NO3--N, reduce the leakage of NO3--N to groundwater, and play an important role in maintaining soil fertility and preventing groundwater pollution.

Experimental investigation of the performances of thick CFRP, GFRP, and KFRP composite plates under ballistic impact

Abstract This study discusses the experimental results of the ballistic impact on thick-layered carbon fibre-reinforced polymer (CFRP), glass-based FRP (GFRP), and Kevlar-based FRP (KFRP) composite plates. Ten 10 mm plates of each type were manufactured via the hand lay-up and vacuum bagging techniques to produce plates with a thickness of 2 mm each, which were bonded together using epoxy adhesive and hot pressed at 75°C to obtain thick layered plates with a total thickness of 20 mm each. The specimen plates were tested according to the NIJ 0108.01 standard in a special firing room using a 9 mm G2 Elite handgun with a full metal jacketed round nose 9 mm × 19 mm Mu1-TJ bullets moving at a velocity of approximately 358 m/s. The results indicated that no total penetration occurred on any of the plates. The bullets were destroyed by impact, and the penetration depths of the CFRP, GFRP, and KFRP plates were 11.10, 9.95, and 22.22%, respectively. The layered structures in these plates appear to have changed the penetration behaviour compared with previous studies. In this study, delamination was the primary failure mode.

Comparative study of the adaptation of alkasite versus self-adhesive flowable restorations

Aim To compare the adaptation of self-adhesive flowable composite versus alkasite restorations with or without the use of an adhesive system. Materials and Methods A total of 30 noncarious maxillary premolars were selected and mounted 2 mm below the cemento–enamel junction in acrylic blocks. Trapezoidal class V cavities were prepared on the buccal surface of each tooth. The gingival margins of the prepared cavities were located 1 mm above cemento–enamel junction. All cavity margins were not bevelled. During the experiment time, all samples were kept in artificial saliva renewed daily at 37°C in an incubator to prevent dehydration. These were randomly divided into three groups (n = 10). Alkasite restorative material was applied in a bulk fill technique using a universal adhesive in samples of group I, while those of group II did not have any adhesive using the same restorative material and those of group III were restored using self-adhesive flowable composite (vertise flow). Specimens of the three tested groups were subjected to 500 thermal cycles from 5 to 55°C with 30 s. Dwell time and 15 s transfer time. They were all immersed in methylene blue dye 2% for 24 h in an incubator. Then all samples were examined under stereomicroscopy at ×40 to determine the percentage of gap free length along the entire margins. All specimens were then sectioned buccolingually to detect the percentage of internal gap length along the restoration/tooth interface. Results Regarding the marginal adaptation, the highest % of marginal free gap was recorded for group I, while the lowest was recorded for group II. Concerning the internal adaptation, it was found that the highest % of free gap was related to group I and III while the lowest was related to group II. Comparing the marginal versus internal % of gap free margins it was found that group I versus II showed a statistically significant difference. Also, group III versus II showed a significant difference. While group I versus III recorded no statistically significant difference. This was true at both marginal and internal % of free gaps. These findings indicated the responsibility of group II for the recorded differences since group II showed the least % of free gap margins and the highest percentage of total dye penetration values. Conclusions Within the limitations of this in vitro study, the adhesive system was effective in increasing the percentage of free gaps of tested groups whether marginal or internal. Recommendations The use of any composite material is not recommended without an adhesive system. Further in vitro studies providing more precise gap measurement are required.

Single and repeated impact behavior of material extrusion-based additive manufactured PLA parts

The advent of Additive Manufacturing (AM) for producing components or parts made of thermoplastic polymers have increased the necessity of a deep knowledge of their mechanical properties. In particular, the mechanical performance under impact loads is still not fully investigated and requires a thorough knowledge. In this paper, polylactic acid (PLA) samples were produced by material extrusion (MEX) technology and subjected to low velocity impact (LVI) tests by using different impactors’ geometries and impact energies. Initially, the PLA filament and MEX-printed samples were subjected to a physico-chemical evaluation through TG, DSC and FTIR analyses. The FTIR and DSC analyzes highlighted phase transitions specific to semicrystalline PLA polymer, while the TG analysis showed that the used printing temperature (220 °C) does not affect the thermal behavior of the filament. The mechanical assessment consisted of single and repeated LVI tests on the same sample until total penetration or failure were reached. The samples subjected to impact tests were analyzed by digital radiography to detect the internal damage and failure mechanisms. The impactor shape has a strong effect on the mechanical strength of the tested samples. For single impacts, the peak load was higher for the 20 mm diameter hemispherical impactor (H20), while the lowest value was experienced by the samples tested with 10 mm diameter hemispherical impactor (H10). The lowest value of specific absorbed energy was recorded with the truncated conical (TC) impactor. For multiple impacts, with the H10 and TC impactors it was possible to impact the sample 4 times, respectively; 2 times with the H20 impactor.

Analysis of wetability properties for kraft paper and corrugated cardboard

Corrugated cardboard and kraft paper are widely used in the packaging industry, providing versatility of use and protection for products. The analysis of the wettability properties of these materials is extremely important, as it allows us to understand how they react to humidity. This research aimed to study the wettability properties of corrugated paper (PO) and kraft paper in order to expand knowledge about the quality of packaging produced with them. The study was conducted in the laboratory using corrugated cardboard (PO) with waves of type "A", "B", "C" "E" and kraft paper obtained from coils with and without coating. The wettability tests performed were total immersion, absorption time and drop penetration method. The collected data was interpreted using descriptive and graphical analysis generated by the R program. The research concluded that for the total immersion test, both materials absorbed more water in the vertical position. In the droplet absorption and penetration time tests, cardboards with type “E” waves showed the highest results when compared to other materials, providing a superior barrier for products that will be transported in boxes of this type. Furthermore, the coated Kraft paper also demonstrated good performance for drop penetration testing, confirming the coating's effectiveness as a moisture barrier.

The Use of Large Metal Heads in Thin Vitamin E–Doped Cross-Linked Polyethylene Inserts Does Not Increase Polyethylene Wear in Total Hip Arthroplasty: 5-Year Results From a Randomized Controlled Trial

BackgroundVitamin E–doped cross-linked polyethylene (VEPE) has encouraged the use of larger heads in thinner liners in total hip arthroplasty (THA). However, there are concerns about wear and mechanical failure of the thin liner, especially when metal heads are used. The aim of this randomized controlled trial was to investigate if the use of a large metal head in thin VEPE liner would increase polyethylene wear compared with a standard 32-mm metal head and to compare periacetabular radiolucencies and patient-reported outcomes in THA. MethodsThere were 96 candidates for uncemented THA who were randomly allocated to either the largest possible metal head (36 to 44 mm) that could be fitted in the thinnest available VEPE liner (intervention group) or a standard 32-mm metal head (control group). The primary outcome was proximal head penetration, measured with a model-based radiostereometric analysis. Secondary outcomes were periacetabular radiolucencies and patient-reported outcomes. The midterm results of the trial at 5 years are presented. ResultsThe median total proximal head penetration (interquartile range) was −0.04 mm (−0.12 to 0.02) in the intervention group and −0.03 mm (−0.14 to 0.05) in the control group (P = .691). The rates of periacetabular radiolucencies were 1 of 44 and 4 of 42 (P = .197), respectively. Patient-reported hip function and health-related quality of life did not differ between the groups, but participants in the intervention group reported a higher level of activity (median University of California Level of Activity score 7 versus 6, P = .020). There were 5 revisions caused by dislocations (2), periprosthetic fracture (1), stem subsidence (1), or iliopsoas impingement (1). ConclusionsLarge metal heads in thin VEPE liners did not increase liner wear and were not associated with liner failure 5 years after THA.

Head, acetabular liner composition, and rate of revision and wear in total hip arthroplasty: a Bayesian network meta-analysis

Total hip arthroplasty (THA) is a common procedure for patients suffering from hip pain e.g. from osteoarthritis, osteonecrosis, or hip fractures. The satisfaction of patients undergoing THA is influenced by the choice of implant type and material, with one key factor being the selection of the appropriate material combination for the bearing surface. In this Bayesian network meta-analysis, we investigated the impact of material combinations for the bearing surface on the longevity of hip implants. The wear penetration rate per year and the total wear penetration in the liner resulting from different material combinations, as well as the survival rate at last follow-up, were examined. We analyzed a total of 663,038 THAs, with 55% of patients being women. Mean patient age was 59.0 ± 8.1 years and mean BMI 27.6 ± 2.6 kg/m2. The combination of an aluminium oxide (Al2O3) head and an Al2O3 liner demonstrated the lowest wear penetration at last follow-up and the lowest rate of wear penetration per year. Additionally, the combination of a crosslinked polyethylene (XLPE) liner and a zircon oxide (ZrO2) head demonstrated the lowest rate of revision at last follow-up. These findings underscore the importance of careful material selection for hip implant bearing surfaces to optimize their longevity and patient satisfaction after THA.

Optimizing the installation of hybrid power plants in non-interconnected islands

This paper proposes a comprehensive optimization approach based on linear programming (LP) for the installation of multiple hybrid power plants (HPPs) in non-interconnected islands. Contrary to the state-of-the-art solutions, the proposed approach optimizes simultaneously the size, location, and technology of each HPP to minimize the long-term electricity cost of the island. The optimization problem is formulated as a LP problem to ensure convergence and global optimum solution. Moreover, a series of system constraints are included in the optimization problem, e.g., power reserves, transmission constraints, maximum renewables' direct penetration limit etc., to ensure the secure and reliable operation of the grid; this is compatible with the actual preventive measures imposed by the network operator in real non-interconnected islands. Simulations are executed in a real Greek Island (Rhodes), confirming the applicability of the proposed method as an optimization tool for network planning studies in non-interconnected islands. The results indicate that the optimal installation of HPPs can yield an annual network cost reduction exceeding 7.9 million €, equating to over 6 % of Rhode's annual cost, as well as a total renewable penetration as high as 51.8 %.

Water-blocking Asphyxia of N95 Medical Respirator During Hot Environment Work Tasks With Whole-body Enclosed Anti-bioaerosol Suit

BackgroundDuring hot environment work tasks with whole-body enclosed anti-bioaerosol suit, the combined effect of heavy sweating and exhaled hot humid air may cause the N95 medical respirator to saturate with water/sweat (i.e., water-blocking). Methods32 young male subjects with different body mass indexes (BMI) in whole-body protection (N95 medical respirator + one-piece protective suit + head covering + protective face screen + gloves + shoe covers) were asked to simulate waste collecting from each isolated room in a seven-story building at 27-28°C, and the weight, inhalation resistance (Rf), and aerosol penetration of the respirator before worn and after water-blocking were analyzed. ResultsAll subjects reported water-blocking asphyxia of the N95 respirators within 36-67 min of the task. When water-blocking occurred, the Rf and 10-200 nm total aerosol penetration (Pt) of the respirators reached up to 1270-1810 Pa and 17.3-23.3%, respectively, which were 10 and 8 times of that before wearing. The most penetration particle size of the respirators increased from 49-65 nm before worn to 115-154 nm under water-blocking condition, and the corresponding maximum size-dependent aerosol penetration increased from 2.5-3.5% to 20-27%. With the increase of BMI, the water-blocking occurrence time firstly increased then reduced, while the Rf, Pt, and absorbed water all increased significantly. ConclusionsThis study reveals respirator water-blocking and its serious negative impacts on respiratory protection. When performing moderate-to-high-load tasks with whole-body protection in a hot environment, it is recommended that respirator be replaced with a new one at least every hour to avoid water-blocking asphyxia.

Experimental Study on Bearing Behavior and Soil Squeezing of Jacked Pile in Stiff Clay

In order to study the bearing behavior and soil-squeezing of jacked piles in stiff clay, two groups of pile penetration tests were performed, with a rough pile that can reproduce the quick-shear behavior of the pile–soil interface, i.e., group 1 in stiffer clay, and group 2 in softer clay for comparison. For each group, the adjacent pile was additionally penetrated at different pile spacings to study the soil-squeezing effect on an adjacent pile. The results show that the penetration resistance increased rapidly at the beginning and then increased at a lower rate. This is because the resistance at the pile end increased rapidly at the beginning and then kept stable with fluctuations, whereas the resistance at the pile side continually increased due to the increasing contact area. Therefore, the ratio of the resistance at the pile end to the total penetration resistance exhibited a softening behavior, which first increased to a peak and then gradually decreased. In addition, there was soil-squeezing stress and soil-squeezing displacement in the ground and adjacent piles due to pile penetration. In stiffer clay, the soil-squeezing stress was larger than that in softer clay due to the higher strength, whereas the soil-squeezing displacement was smaller than that in softer clay due to the low compressibility. In addition, the nonlinear equation form y = ae−bx can be employed to describe the effect of pile spacing on the vertical flotation, horizontal deviation, and pile strain of the adjacent pile.

The impact of digitalization on the sustainability of social orders

The study presents the critical revision of the usual conceptual foundations of complex systems, since the impact of many factors of digitalization directly determines today the viability of societies. The article analyzes the impact of digitalization on the stability of social orders. The purpose of this study is to clarify the possibilities of the impact of digitalization on the stability of social systems. The subject of the article is the social order of modern society in the context of digitalization processes. In modern realities, formed by the total penetration of information and communication technologies into all spheres of human activity, the level of unpredictability and riskiness is clearly increasing, which primarily causes changes in the ontological foundations of social systems. Unprecedented transformations, which have become permanent, have a complex impact on the order that has developed in societies. The author of the article examines in detail the complex impact of digitalization on the stability of social orders. The nature of digitalization processes is presented. Using practical examples, some directions of the influence of advanced technologies on the social fabric are identified. The positive and negative consequences of the manifestation of digitalization processes are highlighted. Vectors of transformation of social institutions are revealed. It is revealed that despite the prevalence of technical and technological elements in public life and the decrease in the humanitarian component and a number of qualities of the human capital of society, which are at a high level of digital development, increase their own stability and functionality. In conclusion, generalizations are presented that constitute a theoretical and methodological basis for subsequent studies of the impact of digitalization on the stability of social orders.

PHYSICAL ATTRIBUTES OF SOIL AND WHEAT PRODUCTIVITY AS A FUNCTION OF COVERING PLANTS AND MECHANICAL CHISELING

Soil compaction is a main physical problem in many growing areas. The use of ground cover crops for soil decompaction has been a subject of many studies. That has promising results both used alone and in association with mechanical chiseling. The objective of this study was to evaluate the influence of cover crops associated or not with mechanical chiseling, for that, on the physical attributes of the soil, and the wheat grain yield, in an Ultisol from the Central Depression of RS. The experimental design used was randomized blocks with 3 replications in each block, in a 2 x 5 factorial scheme. Where the factor A: soil chiseling - chiseled and non-chiseled, and P fator: cover crops – pigeon pea (Cajanus cajan), Crotalaria juncea (Crotalaria juncea), pearl millet (Pennisetum americanum) and velvet bean (Mucuna aterrima). The chiseling was adjusted to a depth of 0.30m, with 5 rods spaced 0.3m apart. The determinations carried out were: macroporosity, microporosity, total soil porosity, bulk density (BD), penetration resistance (RP), and grain yield. The physical attributes of the soil showed improvements in the second year evaluated, highlighting the treatments with pearl millet and velvet bean that showed higher differences. The maximum RP of the Soil was observed at a depth of 0.25m with 1.64 Mpa. There was a significant difference in the RP of the soil between the treatments of factor A at depths of 0.15 - 0.20 and 0.25m. Mechanical chiseling provided a 15% increase in wheat grain yield compared to non-chiseling treatment, while P factor treatments did not provide any gain.