Total Weight Research Articles

Effects of different management practices on the growth and yield of corn

In Indonesia, corn is an important commodity that serves as the second source of carbohydrates after rice, whose productivity is influenced by management practices applied during cultivation. This research aimed to determine the effects of different management practices on the growth and yield of corn. This research was arranged in a single-factor Randomized Complete Block Design, with different agriculture management practices as treatments, consisting of TI1 = Best Practices (Drip Irrigation + Rice Husk + Mycorrhiza), TI2 = Farmers’ Practices (Furrow Irrigation) + Mycorrhiza, and TI3 = Farmers’ practices (Furrow Irrigation). The data observed were analyzed using Analysis of Variance and followed by the Post Hoc Tukey’s HSD at α= 5%. The results showed that the TI1 produced significantly higher plant height, stem diameter, leaf dry weight, weight of cob with cornhusk and kernel dry weight, and effectively suppressed weed growth compared to TI2 and TI3. TI1 produced a significantly higher number of leaves, root dry weight, and total dry weight compared to TI3, but not significantly different compared to TI2. TI1 produced not significantly different stem dry weight and harvest index compared to TI2 and TI3. The kernel dry weight per plant observed in TI1 was 157.63 g, which was 14.22% and 22.91% higher than in TI2 and TI3, respectively. Based on the coefficient correlation and path analysis, the number of leaves, plant height, and total dry weight should be considered as important plant growth variables to produce high kernel dry weight. 

Innovative Ergonomic Support Belt Design to Mitigate Musculoskeletal Issues in School Backpack Users: An Investigation among Jaipur's Students

Heavy school backpacks contribute to physical strain and musculoskeletal disorders (MSDs) among school-going children. Although it is recommended that a child's backpack be at most 10% of their body weight, maintaining this ratio is challenging, particularly in India, where education systems have introduced weight increments in school backpacks. This study investigates the potential of an ergonomically designed support belt for school backpacks in reducing stress on students' shoulders and backs. The research discusses developing and testing a novel ergonomic belt prototype to enhance backpack support for students. Hundred healthy school children aged 12 to 16 participated in an experiment that compared the newly designed belt system with commercially available backpacks without support belts. The study evaluated the impact of backpack type (support belt vs. commercial backpack) and load levels as a percentage of body weight, with test loads ranging from 10 to 30% of the total backpack weight. Participants' feedback, bag comfort scale, and MSD surveys were analyzed to assess the belt system's effectiveness. According to subjective responses, the ergonomic support belt performed well at load levels of 15 to 20% of body weight. A 10% increase in carrying weight reduced erector spinal muscle activity and increased abdominal oblique muscle activity. The innovative backpack design incorporated side pockets connected by upper and lower straps, effectively distributing weight around the body and preventing excessive pressure on specific areas.

ZOOTECHNICAL RESPONSE, PROFITABILITY INDICES, BLOOD PARAMETERS, ORGAN WEIGHT, CARCASS CHARACTERISTICS AND ORGANOLEPTIC PROPERTIES OF PIGS FED PROCESSED CASSAVA ROOT MEAL

Forty (40) weaned pigs (Large white x Landrace, 10 week old, 14.9±0.18 kg body weight) were used to assess the effect of processed cassava root meal on the zootechnical response, profitability, blood parameters, organ weight, carcass characteristics and organoleptic properties of the pigs. The pigs were randomly allotted into four treatments with ten pigs serving as replicates in a completely randomized design. The experiment lasted for forty-nine (49) days. The feed had 0.00%, 32.50%, 48.80% and 65.00% processed cassava root meal in the diets tagged D1, D2, D3 and D4 respectively. The final weight, total weight gain, average daily weight gain, total feed intake, average daily feed intake and feed conversion ratio were significantly different (P<0.05). There were significant differences (P <0.05) in the profitability indices except the feed cost per kg weight gain. All the hematological parameters were significantly affected (P<0.05) except for the mean corpuscular hemoglobin concentration and platelet. All the serum biochemical parameters were significantly (P<0.05) affected except aspartate aminotransferase, urea, total protein, glucose and triglyceride. The weight of the empty stomach, pancreas and heart were not significantly influenced (P>0.05) across the treatments while others were significantly influenced (P<0.05). All the carcass parameters were significantly influenced by processed cassava root meal (P<0.05) except the bled weight, trotter, picnic shoulder and spare rib. The color and juiciness of the meat were also significantly influenced by processed cassava root meal (P<0.05). In conclusion, up to 48.8% is considered favorable in the diet of weaned pigs.

Large-scale production of non-conventional edible plants for biodiverse school meals.

School feeding programs are important for ensuring food security and promoting child health and development, particularly in low-income countries. In view of this importance, it is possible to increase the quality of these meals by diversifying the vegetables offered and incorporating underutilized plants to improve dietary diversity and nutritional quality into school meals. This study was carried out using the action research methodology following the implementation and development of the "Inova na Horta" project in the city of Jundiaí, São Paulo, Brazil. The project was based on the existing and functioning physical and organizational structure of a municipal organic farm. Vegetables were selected from among 210 non-conventional species and varieties, which were further selected for continuous production based on 8 nutritional, culinary and cultivation criteria. Thirty-four vegetables were selected for continuous cultivation and provisions to the school kitchens. Nine tons of vegetables were produced and provided to 90 municipal schools from 2020-2023. Leafy vegetables accounted for most the production, with a total weight of 6441 kg corresponding to 71.6% of the total harvest. Kitchen teams were trained throughout the project duration. The feasibility of the production and culinary use of 34 biodiverse, nutrient-rich and underutilized food vegetables for school meals was demonstrated. The selected vegetables are nutrient-rich and contain higher amounts of minerals and proteins than the control vegetables (conventional vegetables), thus complementing several nutrients in school meals. This methodology can be replicated by municipalities of various sizes as a public policy of food and nutritional security associated with the valorization of local biodiversity.

Estudio comparativo de las características biométricas, composición proximal de macronutrientes y perfil de ácidos grasos de 3 especies del género Orestias

The objective of this study was to evaluate the differences between three species of the genus Orestias (O. luteus, O. olivaceus and O. agassii) in biometry, proximal macronutrient composition and fatty acid profile. A total of 90 fish were used and total length (TL), standard length (LE) and total weight (W) were measured (n = 30 per species), and 10 fish for each group were measured at random to determine fatty acids. The results showed significant differences (p < 0.05) between species; the highest value was obtained by Orestias agassii (TL of 13.00 ± 0.14 cm, LE of 11.86 ± 0.91 cm and W of 27.54 ± 2.78 g). For fatty acids, slightly high values ​​were evident in PUFA (38.56 ± 0.81%), LC PUFA n-3 (25.70 ± 0.28%) and LC PUFA n-6 (13.92 ± 0.81 %) in O. luteus. A higher content of vaccenic acid (18:1ω11) was also found in O. agassii (6.04 ± 0.01 g 100-1 fatty acid), corresponding to a higher intake of algae. It is recommended to develop work on the enrichment of EPA + DHA sources in feed for these species to demonstrate their aquaculture potential, in the search for healthy nutrition for aquatic species.

Unraveling the spawning and reproductive patterns of tomato hind grouper, Cephalopholis sonnerati (Valenciennes, 1828) from south Kerala waters.

The objective of this study is to provide information on the reproductive biology of tomato hind grouper, Cephalopholis sonnerati (Valenciennes, 1828) for conservation and management purposes. Fish caught by artisanal fishermen from September 2019 to August 2021 were analysed. A total of 280 females, 31 males, and 4 transitional and 178 sex-undetermined fish were analysed. The female to male sex proportion was 9:1, and the fish reached a maximum total body length of 38.5 and 54.5 cm for females and males, respectively. The following microscopic stages were identified: immature, developing, ripe, running ripe/releasing, and spent in both males and females. Several asynchronous development patterns were observed in the studied gonads, including multiple oocyte stages and early and advanced stages of sexual transition. High gonadosomatic index (GSI) for both males and females was recorded in March, May, and November. Running ripe and releasing stages in females were identified in the months from March to June, which indicates the spawning season. The absolute and relative fecundity of the species ranged from 162,723 ± 207,267 and 239 ± 285, respectively. An exponential relationship was found between fecundity and total body length (TL), fecundity and total body weight (TW), and fecundity and gonad weight (GW).

Weight loss benefits on HDL cholesterol persist even after weight regaining.

Obesity-related comorbidities may relapse in patients with weight regain after bariatric surgery. However, HDL cholesterol (HDLc) levels increase after surgery and seem to remain stable despite a gradual increase in BMI. The aim of this study is to analyze the effects of weight regain after bariatric surgery on HDL cholesterol. This is a retrospective, observational, cohort study in patients who underwent bariatric surgery in the Hospital de la Santa Creu i Sant Pau (Barcelona) between 2007 and 2015. Patients without at least 5 years of follow-up after surgery, under fibrate treatment, and those who required revisional surgery were excluded from the analysis. Data were collected at baseline, 3 and 6 months after surgery, and then annually until 5 years post-surgery. One hundred fifty patients were analyzed. 93.3% of patients reached > 20% of total weight loss after surgery. At 5th year, 37% of patients had regained > 15% of nadir weight, 60% had regained > 10%, and 22% had regained < 5% of nadir weight. No differences were found in HDLc levels between the different groups of weight regain, nor in the % of change in HDLc levels between nadir weight and 5 years, or in the proportion of patients with normal HDLc concentrations either. HDLc remains stable regardless of weight regain after bariatric surgery.

Tibia properties in broilers raised on their own commercial diets with different growth rates and sex during a 10-week rearing period.

Genetic selection applied to broilers results in fast growth and an increase in meat yield. However, this situation causes welfare problems in broilers. The aim of this study is to determine the weekly changes in the tibia characteristics in broilers raised on their own commercial diets. In the study, 168 (84 female and 84 male) slow-growing (Hubbard-Isa Red JA) and 168 (84 female and 84 male) fast-growing (Ross-308) day-old broiler chicks were used. Six broilers from each genotype and sex group were weighed weekly and slaughtered to determine the tibia properties during the 10-week fattening period. Fast-growing broilers had higher tibia weight and longer length, diaphysis diameter and medullary canal diameter than those of slow-growing broilers at the same age. In fast-growing genotypes, the cortical index was low only in the 2nd week, and Robusticity and Seedor indices were observed to be better throughout the whole fattening. The ash content of the total tibia in the fast-growing broilers was higher in all of the examined weeks except the 4th week and the 9th week of fattening than that in the slow-growing broilers. Although the amount of ash per unit body weight in the 1st week of fattening was higher in fast-growing broilers, this situation reversed after the 4th week. The level of all minerals examined in total tibia weight is high in fast-growing broilers, and they differed according to the fattening period. When comparing tibia characteristics of two different genotypes fed their own commercial diets, the tibia structure was found to be stronger in fast-growing broilers compared to other genotypes at the same age, but slow-growing broilers were more prominent in terms of body weight. It was observed that the mineral density was higher in male broilers, except in the 1st week.

Plant-Growth-Promoting Rhizobacteria and Arbuscular Mycorrhizal Fungi May Improve Soil Fertility and the Growth, Nutrient Uptake, and Physiological Performance of Batavia Lettuce (Lactuca sativa L. var. longifolia) Plants

A greenhouse experiment was realized to investigate the effects of plant-growth-promoting rhizobacteria (PGPR) and arbuscular mycorrhizal fungi (AMF) on soil quality and the growth, nutrient uptake, and physiological performance of Batavia lettuce (Lactuca sativa L. var. longifolia). For this purpose, six fertilization treatments were applied: (i) inorganic fertilization (I.F.—control, i.e., usual/conventional fertilization), (ii) I.F. + PGPR, (iii) I.F. + PGPR + AMF, (iv) manure (MAN), (v) MAN + PGPR, and (vi) MAN + PGPR + AMF. Soil fertility was influenced by the treatments, and soil respiration (CO2 flux) was significantly increased after applications of PGPR and AMF. Following MAN fertilization in particular, an approximately sixfold higher soil respiration value was recorded following the MAN + PGPR + AMF treatment compared to the control (I.F.). Root, leaf, and total biomass dry weights were significantly affected by the PGPR and AMF applications, mainly following the I.F. treatment. In contrast, K, Mg, and Fe uptake was significantly influenced by PGPR and AMF application following the MAN treatment. The SPAD value, performance index (PI), photosynthetic rate, and stomatal conductance were significantly higher in the I.F. + PGPR + AMF-treated plants compared to the control plants. Overall, these data prove the beneficial roles of PGPR and AMF in soil quality and fertility and the nutrient uptake and physiological performance of lettuce plants. However, further clarification is needed in the near future to test the interaction effects between PGPR, AMF, and the type of fertilizer used (organic or inorganic).

Ultraviolet Shielding Performance of Coconut Coir as a Filler in Low-Density Polyethylene (LDPE) Plastic Mulch

Plastic mulch is a layer of material applied to the soil surface to maintain moisture retention in the soil by preventing evaporation, reduce weed growth by blocking sunlight from reaching underlying weeds, and optimize fertilizer use by minimizing nutrient loss to the environment. However, the degradation of low-density polyethylene (LDPE), a thermoplastic commonly used for mulching, into microplastics due to exposure to UV radiation. This research explored the potential of coconut coir, a natural fiber with a high lignin content ranging from 30 to 46%, as a UV protective agent. The objective was to develop biodegradable plastic-based mulch composites that have better resistance to UV exposure by incorporating coir as a filler material in LDPE-based composites. Different ratios of coconut fiber were used (10%, 20%, 30%, and 40%), and Maleic anhydride grafted polyethylene (PE-g-MAH) was used as a binder at 2% of total weight mixed with LDPE in a rheomixer (80 rpm, 120°C for 10 min). The resulting plastic mulch bio-composites were evaluated for thermal, mechanical, UV resistance, and biodegradability properties. The results showed that the higher addition of coconut coir resulted in a decrease in the thermal and mechanical characteristics of the composite. However, the addition of higher coconut coir in the composite at 40% can provide an increase in the composite's resistance to ultraviolet light exposure, and the properties are easily degraded by the environment (biodegradable). 

Aquaculture Performance and Genetic Diversity of a New [(Crassostrea hongkongensis ♀ × C. gigas ♂) ♂ × C. hongkongensis ♀] Variety of the Oyster “South China No. 1” in Beibu Gulf, China

Crassostrea hongkongensis is an economically important bivalve found in various parts of the South China Sea. A new interspecific backcross ([(Crassostrea hongkongensis ♀ × C. gigas ♂) ♂ × C. hongkongensis ♀]) variety was bred by the South China Sea Institute of Oceanology which named “South China No. 1”. This study aims to explore the effects of stocking density on the growth performance of “South China No. 1”, compared their growth performance and genetic diversity to C. hongkongensis, and found the best place breeding site for “South China No. 1” in Beibu Gulf. The results showed that stocking a density of 20 oysters/substrate can significantly increase the shell height, shell width, total weight, survival rate, daily shell height gain and daily body mass gain. It was found that the shell height and total weight of “South China No. 1” cultured in Fangchenggang were significantly higher than that of those in Beihai and Qinzhou from September 2018 to November 2018. Similarly, the shell width of oysters in Fangchenggang and Qinzhou was also significantly higher in September 2018, and the interaction between site and stocking density had significant effects on the shell width in March 2018 and November 2018. In addition, the shell height and shell width of “South China No. 1” were significantly higher than that of C. hongkongensis in all three sites. At all three sites, the phytoplankton community structure was mostly dominated by Bacillariophyta. In the Hardy–Weinberg equilibrium test, for the seven populations and ten microsatellites, in 10 of the 70 groups, the segregation distortion was significant. These results suggest that a stocking density of 20 oysters/substrate can promote the shell height, shell width and total weight of “South China No. 1” in Beibu Gulf, China. “South China No. 1” has better growth performance compared with C. hongkongensis. Fangchenggang is a suitable place to cultivate the “South China No. 1” breed according to the total weight and sum of all algal genus abundances. The results of this study can be used as a reference to further understand the stocking density and genetic diversity of the “South China No. 1” breed in Beibu Gulf, China.

Multimodal approach utilising a weight management programme prior to bariatric surgery in patients with BMI ≥50 kg/m2: A propensity score matching retrospective cohort study.

We evaluated preoperative weight loss and days from initial consult to surgery in patients with BMI ≥50 kg/m2 who were and were not enrolled in medical weight management (MWM) prior to laparoscopic sleeve gastrectomy. We retrospectively identified patients with BMI ≥50 kg/m2 who had primary sleeve gastrectomy between 2014 and 2019 at two bariatric surgery centres in our healthcare system. Patients presenting after 2017 that received preoperative MWM (n = 28) were compared to a historical cohort of non-MWM patients (n = 118) presenting prior to programme initiation in 2017 on preoperative percent total body weight loss (%TBWL) and days from initial consult to surgery. A total of 151 patients (MWM, 33; non-MWM, 118) met inclusion criteria. BMI was significantly greater in MWM versus non-MWM (p = .018). After propensity score matching, median BMI at initial consult in non-MWM versus MWM no longer differed (p = .922) neither were differences observed on the basis of weight, age, sex, race or ethnicity. After PSM, MWM had significantly lower BMI at surgery (p = .018), lost significantly more weight from consult to surgery (p < .001) and achieved significantly greater median %TBWL from consult to surgery (p < .001). We noted no difference between groups on 6-month weight loss (p = .533). Days from initial consult to surgery did not differ between groups (p < .863). A preoperative MWM programme integrated into multimodal treatment for obesity in patients with a BMI ≥50 kg/m2 resulted in clinically significant weight loss without prolonging time to surgery.

A practical main frame for convex-deformable mobile devices

In the existing mobile devices, such as iPads, the touchscreen & display assembly and the rear cover account for at least 60% of the total device weight. Therefore, device weight can be reduced significantly only by replacing these glass and metallic components with non-glass and polymeric equivalents. Recently, the authors’ research group demonstrated a monolithically polymeric sandwich plate that is convex-deformable, even with solid chips embedded in its cores. In this study, a new design of this sandwich plate is proposed to facilitate its use as a practical main frame of a mobile device. This design is validated by conducting finite element analyses and experiments involving three-dimensionally printed prototype of the proposed sandwich plate design. The plate is fabricated as two separate halves that are then assembled using snap-fits to form a single body. A flexible printed-circuit board with regularly arranged elliptical holes and many solid chips embedded on its upper and lower surfaces is accommodated within the core of the proposed plate. In addition, rib-like side covers and an overall latex coating are used to protect all four sides and the entire outer surface, respectively, without adversely affecting the overall convex deformation of the proposed plate design.

Acute Response to Training after Returning from the Off-Season in Elite Rugby League Athletes.

The purposes of this study were to quantify the physiological response to the initial two-week preseason period in elite male rugby league (RL) athletes, and to determine if a repeated bout effect (RBE) occurs. Eighteen RL players were monitored for the initial two-week preseason period. Blood samples were collected on days (D)1, D2, D4, D5, D8, D9, D11 and D12 to measure creatine kinase (CK). Neuromuscular power was assessed on D1, D5, D8 and D12. During field-based sessions, the external training load was quantified using global positioning system technology, whilst the internal load was quantified using the training impulse and the session rating of perceived exertion. Resistance-based gym session volume was quantified by total repetitions x weight lifted. Perceived measures of fatigue and muscle soreness were assessed on all training days. Two-way (day x week) repeated measures analysis of variance and Bonferroni's corrected post-hoc tests identified significant changes. There were no significant changes in CK activity (649.2 ± 255.0 vs. 673.8 ± 299.1 µL; p = 0.63) or internal training load measures from week 1 to week 2. External training load measures including total distance (4138.1 ± 198.4 vs. 4525.0 ± 169.2 m; p < 0.001) and repeated high-intensity efforts (12.6 ± 1.8 vs. 17.5 ± 1.8 au; p < 0.001) significantly increased in week 2 compared to week 1. Internal training loads and CK activity did not change in response to an increase in external training loads during the initial preseason. The current results provide support for a 'real world' perspective of the RBE phenomenon that may be more applicable for team sport practitioners.

Fatigue Performance Evaluation of Fiber-Reinforced Asphalt Mixtures with Four-Point Bending Beam and Uniaxial Fatigue Tests

This study aimed to evaluate the fatigue cracking potential of aramid fiber–reinforced asphalt mixtures. Three fiber-reinforced asphalt mixtures (FRAMs) were prepared employing a singular aggregate type (diabase stone), one binder type (PG76-22), and two distinct combinations of aramid fibers at varying dosages. Two types of fiber were used at different dosages by weight of mix: polyolefin/aramid (PFA) fibers at a dosage 0.05% and sasobit-coated aramid (SCA) fibers at dosages of 0.01% and 0.02%. Additionally, an unreinforced (control) mix was also produced for comparison purposes. Each of the mixtures was produced at a batch plant, adhering to the fiber manufacturer’s recommended mixing methods, while maintaining a constant binder content of 5.5% based on the total mix weight. Four-point beam (4PB) fatigue, uniaxial fatigue (UF), and Texas overlay tests (OT) were performed to characterize the fatigue and reflective cracking behavior of FRAM. The 4PB test results suggest that FRAM improved the fatigue life at lower strain levels (400 µε and 600 µε); however, at higher microstrain (800 µε) level, FRAM exhibited lower fatigue life than the control mix. Damage characteristic curves obtained from the UF tests showed better fatigue tolerance for reinforced mixtures, regardless of microstrain level. For cycles to failure under tensile loading, UF and OT test results indicated lower fatigue life of reinforced mixtures compared with the control mix. Therefore, under flexural loading the fiber-reinforced asphalt mixtures tend to improve the fatigue life. However, for direct tension load, reinforced mixtures tend to deteriorate the fatigue life when comparing cycles to failure at constant strain amplitude.

EVALUATION OF SELECTED MECHANICAL AND PHYSICAL PROPERTIES OF PARTICLEBOARDS CONTAINING WASTE PLASTICS

This article is focused on the research of particleboards (PB) composed of wood particles from spruce logs and recycled crushed plastic granulates. Crushed plastic granulates sized from 1.0 to 4.0 mm were obtained from worn automobiles by recycling, specifically painted and unpainted bumpers. The proportion of plastic granulate in the particleboards represented 10%, 15%, and 20% of the total weight of the composites. In the production of PB, urea-formaldehyde resin and paraffin emulsion were used as a binder and ammonium nitrate was used as a hardener. The aim of the article was to compare the selected properties of PB containing plastic filler with pure PB. Mechanical properties (tensile and bending strength), and physical properties (water absorption and thickness swelling) were evaluated according to EN 319, EN 310 and EN 317. Based on the results, it can be stated that the bending strength and physical properties of PB containing plastic filler were significantly better compared to pure PB. On the contrary, the tensile strength values were lower in most cases.

Pengaruh Konsentrasi Oksida Logam CuO Sebagai Superkapasitor Berbasis Karbon Aktif

Supercapacitors are promising energy storage devices in future energy technology. In this research, the primary and applied aspects of supercapacitors are developed. Various techniques have been developed specifically to estimate specific capacitances. Various attempts have been made in the literature to increase the specific capacitance value of the electrode materials. Electrode materials with unique structural and electrochemical properties, such as high capacity and cyclic stability, exhibit good supercapacitor performance. Many new electrode materials have been developed to play an essential role in capacitance behavior. This research focuses on the highly efficient application of nanostructured electrode materials such as nanoporous carbon and metal oxide CuO for supercapacitors. Nanopore carbon is made from coconut shell, which is synthesized using a simple heating method. Next, carbon nanopore and CuO nanoparticle composites were carried out with composition variations of 0.5,10,15, and 20% of the total weight. The results of cyclic voltammetry, electrochemical impedance spectroscopy, and charge-discharge tests, maximum results were obtained on a composition of 5% CuO nanoparticles with a capacitance of 280 F/gr and a conductivity of 1.14 X 10-2 S/cm. This result is due to an increase in the surface area between the pore surfaces, so more ions are trapped, causing the filling process to take place quickly.

Zinc Oxide Nanoparticles and Zinc Sulfate Alleviate Boron Toxicity in Cotton (Gossypium hirsutum L.).

Boron toxicity significantly hinders the growth and development of cotton plants, therefore affecting the yield and quality of this important cash crop worldwide. Limited studies have explored the efficacy of ZnSO4 (zinc sulfate) and ZnO nanoparticles (NPs) in alleviating boron toxicity. Nanoparticles have emerged as a novel strategy to reduce abiotic stress directly. The precise mechanism underlying the alleviation of boron toxicity by ZnO NPs in cotton remains unclear. In this study, ZnO NPs demonstrated superior potential for alleviating boron toxicity compared to ZnSO4 in hydroponically cultivated cotton seedlings. Under boron stress, plants supplemented with ZnO NPs exhibited significant increases in total fresh weight (75.97%), root fresh weight (39.64%), and leaf fresh weight (69.91%). ZnO NPs positively affected photosynthetic parameters and SPAD values. ZnO NPs substantially reduced H2O2 (hydrogen peroxide) by 27.87% and 32.26%, MDA (malondialdehyde) by 27.01% and 34.26%, and O2- (superoxide anion) by 41.64% and 48.70% after 24 and 72 h, respectively. The application of ZnO NPs increased the antioxidant activities of SOD (superoxide dismutase) by 82.09% and 76.52%, CAT (catalase) by 16.79% and 16.33%, and POD (peroxidase) by 23.77% and 21.66% after 24 and 72 h, respectively. ZnO NP and ZnSO4 application demonstrated remarkable efficiency in improving plant biomass, mineral nutrient content, and reducing boron levels in cotton seedlings under boron toxicity. A transcriptome analysis and corresponding verification revealed a significant up-regulation of genes encoding antioxidant enzymes, photosynthesis pathway, and ABC transporter genes with the application of ZnO NPs. These findings provide valuable insights for the mechanism of boron stress tolerance in cotton and provide a theoretical basis for applying ZnO NPs and ZnSO4 to reduce boron toxicity in cotton production.

Structural Optimization of 60T Electric Mining Vehicle Frame: Finite Element Simulation Model and Analysis

Based on the research under the ore loading condition of the electric mine vehicle, this paper measures the physical frame of the 60T electric mine vehicle by means of rangefinder, ruler and drawings, and uses the software CATIA to complete the three-dimensional model of the frame and carriage of the electric mine vehicle, combined with the characteristics of ANSYS workbench software. The structure of the model is simplified. By comprehensively applying relevant knowledge of automobile dynamics, the frame load under full load condition is calculated, and the electric mine vehicle frame is applied by using ANSYS workbench software to simulate and optimize the three conditions of stationary, high-speed driving and turning before the mine car, and the position where the stress concentration and deformation of the frame structure are greatest. By increasing the thickness of the support plate and increasing its stress area, the overall weight was increased by 90.35kg, accounting for 0.9% of the total weight, and the weight increase was very small. Mechanical analysis was carried out on the three working conditions of the optimized frame of the mine car, and the stress was reduced by 25%, 24.1% and 39.2% respectively, effectively eliminating the stress concentration. The actual use of the vehicle can extend the service life of the frame, while improving the economy and stability of the vehicle.

Topology optimization of gradient lattice structure filling with damping material under harmonic frequency band excitation

With the rapid development of 3D printing technology, lattice structures have been widely utilized in structural designs aimed at vibration resistance due to their excellent performance. In this study, considering the moderate improvement of vibration suppression property of existing graded lattice, we introduce high-damping material into the optimization framework and further enhance the vibration resistance ability of gradient lattices. This framework extends the existing framework of stiffness and mass distribution to incorporate the distribution of stiffness, mass, and damping, which allows us to consider the damping changes with the cell configuration. Initially, the lattice cells are assigned with two different constitutive materials, one with high stiffness and the other with excellent damping properties. Different from traditional lattice units, we can obtain a series of lattice units with adjustable stiffness , mass and damping in a certain range. Via the homogenization method on the frequency domain, the complex elastic matrices about distribution of these lattice cells controlled by three parameters are obtained. In the meantime, the loss factor of these lattice cells is also obtained. A polynomial-based interpolation technique is employed to characterize the graded lattice units, which is integrated into an optimization process aimed at minimizing the lattice structures’ vibration responses. Several numerical examples are presented to illustrate this framework’s effectiveness, and experimental tests on 3D printed specimens are conducted to validate the numerical results. It’s worth noting that under the condition that the total weight of the structure remains unchanged, this weakens the overall stiffness of the structure (the reduction of first-order natural frequency), but greatly increases the damping of the structure (with a widened resonance peak) to resist the vibration of the structure. For the lattice structures induced by damping materials, the average loss factor is 0.114, which is almost doubled to the average value of those not including the damping material. When comparing the results of the mean displacement amplitude with and without damping materials, the reduction of displacement amplitude of lattice structures is above 25 %. The methodology expands the scope of optimization design for lattice structures, moving beyond stiffness maximization to include vibration mitigation by determining the appropriate distribution of stiff and damping materials, showcasing the practical applicability of the presented methods in engineering practice.