Blade Length Research Articles

Individual architecture and photosynthetic performance of the submerged form of Drosera intermedia Hayne

Drosera intermedia grows in acidic bogs in parts of valleys that are flooded in winter, and that often dry out in summer. It is also described as the sundew of the most heavily hydrated habitats in peatlands, and it is often found in water and even underwater. This sundew is the only one that can tolerate long periods of submersion, and more importantly produces a typical submerged form that can live in such conditions for many years. Submerged habitats are occupied by D. intermedia relatively frequently. The aim of the study was to determine the environmental conditions and architecture of individuals in the submerged form of D. intermedia. The features of the morphological and anatomical structure and chlorophyll a fluorescence of this form that were measured were compared with analogous ones in individuals that occurred in emerged and peatland habitats. The submerged form occurred to a depth of 20 cm. Compared to the other forms, its habitat had the highest pH (4.71–4.92; Me = 4.71), the highest temperature and substrate hydration, and above all, the lowest photosynthetically active radiation (PAR; 20.4–59.4%). This form differed from the other forms in almost all of the features of the plant’s architecture. It is particularly noteworthy that it had the largest main axis height among all of the forms, which exceeded 18 cm. The number of living leaves in a rosette was notable (18.1 ± 8.1), while the number of dead leaves was very low (6.9 ± 3.8). The most significant differences were in the shape of its submerged leaves, in which the length of the leaf blade was the lowest of all of the forms (0.493 ± 0.15 mm; p < 0.001) and usually the widest. The stem cross-sectional area was noticeably smaller in the submerged form than in the other forms, the xylem was less developed and collaterally closed vascular bundles occurred. Our analysis of the parameters of chlorophyll fluorescence in vivo revealed that the maximum quantum yield of the primary photochemistry of photosystem II is the highest for the submerged form (Me = 0.681), the same as the maximum quantum yield of the electron transport (Me φE0 = 0.183). The efficiency of energy use per one active reaction center of photosystem II (RC) was the lowest in the submerged form (Me = 2.978), same as the fraction of energy trapped by one active RC (Me = 1.976) and the non-photochemical energy dissipation (DI0/RC; Me = 0.916). The ET0/RC parameter, associated with the efficiency of the energy utilization for electron transport by one RC, in the submerged plant reached the highest value (Me = 0.489). The submerged form of D. intermedia clearly differed from the emerged and peatland forms in its plant architecture. The submerged plants had a thinner leaf blade and less developed xylem than the other forms, however, their stems were much longer. The relatively high photosynthetic efficiency of the submerged forms suggests that most of the trapped energy is utilized to drive photosynthesis with a minimum energy loss, which may be a mechanism to compensate for the relatively small size of the leaf blade.

Verification of Euler–Bernoulli beam theory model for wind blade structure analysis

This paper presents a computational tool for analyzing the structural response of wind turbine blades using the advanced Euler–Bernoulli Beam theory. The objective is to achieve efficient computation of blade structural response under aerodynamic loading without sacrificing computational accuracy. This study involves the development of a Python-based computer program as a numerical tool, which utilizes inputs such as blade geometry and aerodynamic loading from Blade Element Momentum theory. The program outputs axially varying moments of inertia, spatial deflections of the blade, and stress distributions within the blade. The numerical tool is verified by comparing the results with both analytical solutions and far more time-consuming commercial finite element solvers. One of the key contribution of this research is the application of the polygon algorithm, which efficiently calculates the moments of inertia of web-stiffened turbine blades along the blade length. It is shown herein that this algorithm significantly reduces computational time while maintaining numerical accuracy as compared to the results obtained from commercially available finite element codes. The study confirms that the advanced Euler–Bernoulli beam theory, when combined with the polygon algorithm, is capable of accurately predicting the structural response of cambered and twisted wind turbine blades during the initial design phase.

Exploring the complexities of plant UV responses; distinct effects of UV-A and UV-B wavelengths on Arabidopsis rosette morphology

UV-B radiation can substantially impact plant growth. To study UV-B effects, broadband UV-B tubes are commonly used. Apart from UV-B, such tubes also emit UV-A wavelengths. This study aimed to distinguish effects of different UV-B intensities on Arabidopsis thaliana wildtype and UVR8 mutant rosette morphology, from those by accompanying UV-A. UV-A promotes leaf-blade expansion along the proximal–distal, but not the medio-lateral, axis. Consequent increases in blade length: width ratio are associated with increased light capture. However, petiole length is not affected by UV-A exposure. This scenario is distinct from the shade avoidance driven by low red to far-red ratios, whereby leaf blade elongation is impeded but petiole elongation is promoted. Thus, the UV-A mediated elongation response is phenotypically distinct from classical shade avoidance. UV-B exerts inhibitory effects on petiole length, blade length and leaf area, and these effects are mediated by UVR8. Thus, UV-B antagonises aspects of both UV-A mediated elongation and classical shade avoidance. Indeed, this study shows that accompanying UV-A wavelengths can mask effects of UV-B. This may lead to potential underestimates of the magnitude of the UV-B induced morphological response using broadband UV-B tubes.Graphical abstract

Control of separation flows of turbine-blade-tip turbines by splitter blades

Gas turbines cannot be directly reversed, and the astern operation of gas turbines still requires additional power transmission equipment to be achieved. To compensate for this deficiency, the application of turbine-blade-tip turbine in gas turbines was proposed. Turbine-blade-tip turbines have the characteristics of extremely low solidity and extremely high diameter-span ratio. Compared with conventional turbine blades, the capacity of turbine blades to restrain gas flow is greatly weakened, the separation flow is obvious when going astern, resulting in low efficiency. For the control problem of low solidity turbine-blade-tip turbines separation flow, a splitter blade control strategy is selected to suppress the separation flow. Adding a splitter blade between original rotor blades effectively improves the ability of rotor blades to restrain gas flow, significantly reduces separation phenomena, and significantly improves efficiency. As the axial chord length of the splitter blade shortens, the inhibitory effect on the separation flow decreases, and the ability of splitter blades to improve the efficiency gradually descends.

Feasibility study of geosynthetic vegetation substrate for hard-surface ecological restoration part 1: Development of designated vegetation

Current ecological restoration techniques often face challenges on steep and hard surfaces (e.g., concrete or rock surfaces) because of their reliance on soil as a vegetation substrate. Two geosynthetic-based ecological restoration techniques are proposed in which a geosynthetic material is used to replace the soil as a vegetation substrate on hard-surface slopes. In the first technique, vegetation is planted directly on a geosynthetic vegetation substrate (GVS), where the GVS provides water to the vegetation and room for the growth of vegetation roots. In the second technique, Hygrophila ringens is first planted on the GVS. This plant exhibits rapid growth initially and then dies after three months, creating a layer of humus over the GVS. Subsequently, herbaceous vegetation can grow over the GVS. The effectiveness of the GVS restoration technique was verified by conducting a one-year-long experimental study. During the experiment, vegetation such as Tall Fescue, Bermuda grass, bentgrass, Chinese holly, and Tifdwarf were grown on the GVS. Vegetation growth parameters such as blade length, biomass production, and species iteration were monitored with respect to the vegetation species and seeding density. The experimental results suggest that both ecological restoration techniques based on the GVS can successfully sustain vegetation on concrete slopes.

Maximisation the autonomous flight performance of unmanned helicopter using BSO algorithm

AbstractThe usage areas of rotary or fixed wing unmanned aerial vehicles (UAV) have become very widespread with technological developments. For this reason, UAV designs differ in terms of aerodynamic design, flight performance and endurance depending on the intended use. In this study, maximising of the autonomous flight performance of the unmanned helicopter produced at Erciyes University using an optimisation algorithm is discussed. For this purpose, the input parameters of the dynamic model are chosen as blade length, blade mass density, blade chord width and blade twist angle of the unmanned helicopter and the proportional, integral, derivative gain coefficients of the lateral axis of the autopilot. The output parameters of the dynamic model are selected as settling time, rise time and maximum overshoot, which are autonomous performance parameters. The dynamic model consisting of helicopter and autopilot parameters is integrated into the back-tracking search optimisation (BSO) algorithm as an objective function. In the optimization process, where mean squared error (MSE) is used as the performance criterion, optimum input and output values were determined. Thus, helicopter and autopilot parameters, which are among the factors affecting autonomous performance, are taken into account with equal importance and simultaneously. Simulations show that the obtained values are satisfactory. With this approach based on the optimisation method, complex and time-consuming dynamic model calculations are reduced, time and cost are saved, and practicality is achieved in applications. Therefore, this approach can be an innovative and alternative method to improve UAV designs and increase flight performance compared to classical methods.

Research on the Effect of Thermal Coating Temperature on the Fatigue Performance of Wind Turbine Blade Bolts

The bolted connection of wind turbine blades is a bridge for transmitting blade loads. In recent years, with the rapid increase in blade length, the fatigue load at the blade root has also been continuously increasing. The bolt fatigue strength has always been a bottleneck in the interface design between blade and wind turbine hub. However, industry standards still hold conservative values for the S/N curve of bolt fatigue, and there are unclear requirements for thermal coatings, The S/N curves provided by the standards in different periods do not meet the actual processing requirements of bolts. In order to study the effect of thermal coating temperature on the fatigue performance of threads and provide a reasonable basis for the subsequent design of long blade bolt connections. Based on the actual processing technology of bolts, experiments were conducted on the S/N fatigue curves of thermal coated bolts at different temperatures. The experimental results prove that the slope of the inclined part of the low-temperature Dacromet test data and the fatigue strength under 2 million cycles are significantly higher than normal temperature Dacromet coated bolts. Low temperature Dacromet can effectively improve the fatigue strength of bolts.

Characterization based on colorimetry, physiology and sensory attributes among traditional jujube cultivars of Sindh, Pakistan

Jujube (Ziziphus spp.) fruit is attaining incredible attention in current global climatic changing scenario as the fruit has significant nutritional value but remained unexplored in past. Fifteen Jujube cultivars were selected at Jujube Research Station Tandojam, Sindh Pakistan, to exploit their morphological, physiochemical, color and sensory attributes. Measured traits like tee shape diverged as semi erect, erect and spreading whereas leaf shape was also found highly variable. Thorn attachment differed as cadoucous, partial and persistent and fruit shape was set as round, oblong, oval and ovate. Maximum leaf blade length was counted by Soofi sanghar (9.0cm) while lowest was found in Gola soghat (5.1cm). Maximum fruit mass was recorded in cultivar Late gola (31.57 g) whereas least was observed in Khirol mukkhri (5.63 g). Maximum stone weight was estimated in Early gola (10.55 g) whereas minimum was recorded in Khirol desi (6.4 g). Highest glucose level was observed in Soofi local (4.46 g 100 mL−1) while lowest glucose level was recorded in Khirol desi and Khirol Ratam (3.53g 100 mL−1). Best cultivars by appearance were Late gola and Early gola followed by Gola saffina, Gola soghat, Soofi sanghar and Soofi local. Findings of this study are useful for varietal improvement and to run successful breeding programmes. Commercially relevant features evaluated in this study are highly beneficial for jujube varietal identification and germplasm conservation

Hydrodynamic characteristics of a waterjet propulsion pump with front straight guide vane

ABSTRACT This research proposes a front straight guide vane (FSGV) to suppress pre-rotation before the waterjet pump, forming a double guide vane (DGV) with the rear guide vane (RGV). To verify its effectiveness, the hydrodynamic characteristics are studied numerically. The simulated external characteristic curve is consistent with the experimental result. The parameter optimisation of FSGV is processed. The result shows that FSGV can improve the adverse inflow pattern significantly and is beneficial to the hydrodynamic characteristics, and the propulsion performance is improved significantly with the increasing blade length and the axial gap. In addition, when the rotating speed is less than 3.29 times the design rotating speed, the influence on the cavitation performance by the DGVs in the impeller can be ignorable. However, the cavitation grows worse if the rotating speed increases far outweighing the design rotating speed, at which the propulsion pump never operates.

Modeling Design of Picohydro Power Generation System Using Crossflow Turbine

The goal of this project is to learn how to use a Crossflow turbine to create a Picohydro power plant system modeling. The manufacturing process, from design to evaluation, is the methodology employed. The turbine type utilized is a crossflow turbine, measuring 26 cm in outer diameter, 17.3 cm in inner diameter of the blade runner, and up to 35 pieces of blades. The calculations show that the distance between the blades is 2.3 cm, the blade length is 8.5 cm, the blade width is 4.4 cm, and the radius of curvature of the blade is 2.8 cm. The test results without load obtained the highest turbine rotation of 421 Rpm produces a voltage of 7.29 V before going through the boost converter.

Experimental cultivation of Neopyropia kitoi (Bangiales, Rhodophyta) for the establishment of a new marine crop in nori cultivation: A field experiment assessment of growth, pigments and free amino acids

To elucidate whether Neoporphyra kitoi strain OHN-1 has superior characteristics as a new marine crop in the nori farm setting, we compared OHN-1 and Neopyropia yezoensis f. narawaensis strain U-51 cultivated under identical conditions during the early nori season. We assessed the growth and the contents of photosynthetic pigments and free amino acids (FAAs), which affect the quality and taste of nori, between OHN-1 and U-51. The blade length of OHN-1 was found to be significantly longer than that of U-51, and OHN-1 exhibited high-yield characteristics. Notably, the blade thickness of OHN-1 was only slightly greater than that of U-51, despite the significant differences between the two strains. The contents of pigments and FAAs related to the taste were also higher in OHN-1 than in U-51. These results obtained with a N. kitoi cultivar demonstrated that N. kitoi has superior growth and quality characteristics in the nori farm setting. Thus, we concluded that N. kitoi could be used as a new marine crop for nori cultivation.

Comparative Analysis of Endodontic ISO Size 06, 08, and 10 Stainless Steel K-Files Used for Glide Path Procedures.

Small-sized stainless steel hand files are conventionally employed in root canal treatment procedures for canal scouting and for glide path establishment, owing to their superior flexibility and proficiency in navigating confined spaces. Given the diversity of brands available in the market, there exists potential variability in their physical characteristics, thereby influencing clinical performance. Consequently, this study aims to conduct a comparative analysis of the design, metallurgy, and mechanical characteristics among seven stainless steel hand file brands across ISO sizes 06, 08, and 10. A total of 315 new 25 mm length stainless steel hand files with apical sizes of 0.06, 0.08, and 0.10 from seven distinct brands were included in the study. A meticulous inspection of all instruments was undertaken to identify any structural deformations that might render them ineligible for the study. The design inspection involved the random selection of instruments from each group, which were examined under various microscopes, including a dental operating microscope, optical microscope, and scanning electron microscope. Furthermore, two instruments from each group underwent energy-dispersive X-ray spectroscopy analysis for elemental composition documentation. Mechanical tests were conducted to evaluate the instruments' resistance to lateral deformation (buckling) and their microhardness. Statistical analysis was executed using the nonparametric Mood's median test, with a predetermined significance level of 0.05. Regarding the instruments design, all files exhibited an active blade length ranging from 16 to 17 mm. However, variations were observed in the number of spirals, tip designs, and sizes, with the API K-File notably larger in sizes 0.06 and 0.08 compared to the other instruments. Despite uniform elements composition, differences in geometric features and mechanical properties were evident. Concerning buckling strength, the API K-File demonstrated superior performance across all tested sizes, while the Dentsply ReadySteel, SybronEndo, and Mani K-Files exhibited lower results (p < 0.05). In microhardness assessments, both the API and Oro K-Files displayed the lowest outcomes, with medians of 531 HVN and 532 HVN, respectively, whereas the SybronEndo K-File exhibited the highest microhardness (657 HVN). Despite similar metallurgical composition, the observed distinctions in geometric features and mechanical properties underscore the impact of the manufacturing process on the characteristics of glide path stainless steel endodontic files. These disparities may ultimately influence their clinical performance.

Seagrass repression by green turtles (Chelonia mydas) around Taiping Island in the south China sea: Experimental evidence and management insights

Seagrass meadows serve as critical marine habitats, offering numerous benefits to both humans and wildlife. Taiping Island, situated in the South China Sea, has been historically known for its abundant seagrass meadows. However, satellite imagery suggested there was a low density of seagrasses around Taiping Island. On the other hand, many green turtles (Chelonia mydas) were observed from the shore. To investigate this phenomenon, we conducted drone surveys of the shallow reefs and discovered a density of 902 ± 601 (mean ± SD) individual turtles per square kilometer during high tides. In addition, we conducted a cage experiment to test the hypothesis that large herbivores are impacting seagrass abundance negatively. The results indicated that the blade lengths of seagrasses in cages were significantly longer than those outside. It is likely that large herbivores such as green sea turtles are the key consumers of seagrass on the shallow reef flats of Taiping Island. Accordingly, further research and management should take into account that the increasing number of sea turtles may deplete the seagrasses and have an impact on the seagrass ecosystems.

SIMULATION OF TRANSIENT PROCESSES IN THE STABILIZATION SYSTEM OF DARRIEUS WIND TURBINE ROTOR ROTATIONS

In the work, the simulation of transient processes of the rotor speed system stabilization of vertical-axis wind turbines, controlled by changes of the blade length, is carried out. It is proved that real roots of the characteristic equation of a closed system with the proportional-integral law of feedback leads to a significantly longer length of transient processes than with complex-connected roots.

SCAMORSA-1: a camber-morphing wind turbine blade with sliding composite skin

Wind turbines form an increasingly important source of renewable and sustainable energy. Traditional rigid wind turbine blades are unable to control the flow of air over their surfaces, resulting in higher loads and lower aerodynamic efficiency at non-optimal wind speeds and angles of attack. This paper presents the design of SCAMORSA-1 (“Sliding CAmber- MORphing Skin Action”), a camber-morphing turbine blade in a Horizontal Axis Wind Turbine (HAWT) for increased aerodynamic efficiency and improved extreme load alleviation. The blade is linearly tapered and comprises three sections: a conventional rigid section, a morphing section, and a fixed blade tip, all covered by functionally graded composite skin. Measured from the root, the rigid section spans 0%-60% of the total blade length and its profile transitions at 20% from SD7062 thick airfoil to the thinner SD7037 airfoil. The rigid section includes carbon fiber composite spars that resist flap-wise bending. The morphing section occupies the next 30% of the span with SD2030 airfoil profile and can seamlessly change camber angle up to 10°. This section is composed of three hybrid ribs connected via two leading-edge composite spars and a trailing-edge synchronizing rod. Each hybrid rib has a solid leading-edge segment connected to a flexible trailing-edge segment via T-slots. The trailing-edge segment, where morphing occurs, is an enhanced version of the corrugated FishBAC design, with hexagonal honeycomb infill that increases the out-of-plane stiffness and allows for morphing deformation without internal buckling. Two of these hybrid ribs have servomotors housed in the leading-edge segment. These integrated actuators in the hybrid ribs actuate flexible carbon fiber ribbons that run through slits in the trailing-edge segment to morph it. At the trailing-edge portion of the morphing section, the composite skin transitions to a thin flexible layer that can slide over the deforming trailing-edge segment via skin sliders. Computational simulations were performed to quantify the performance gains and ensure safe operation of all components. A proof-of-concept model of SCAMORSA-1’s morphing section was manufactured and tested to demonstrate the effectiveness of the design.

Blade-coating-casing rubbing induced vibration responses and wear characteristics

To study the rubbing-induced wear characteristics and vibration responses in a blade-coating-casing system, a dynamic model of the rotating blade-coating-casing system with rubbing is established considering the rotational effect of blades and the aerodynamic force of blades. Then, the wear models were verified by comparing results in the literature. Finally, the numerical simulation is conducted considering the effects of different parameters. The results show that with the increase of Archard coefficient, particle size, Young's modulus, and blade length, the more severe the wear of coatings. The rotational speed has the greatest influence on the circumferential wear amount of coatings and the wear pattern is influenced by the aerodynamic forces.

Genetic variability and QTL mapping of morphological traits and inflorescence prolificacy in African bermudagrass

AbstractAfrican bermudagrass (Cynodon transvaalensis Burtt‐Davy) (2n = 2x = 18) has unique morphological characteristics such as finer leaf blades and shorter internodes that are important to improving turf qualities (i.e., texture and density) as compared to other Cynodon species. It has been extensively used to cross with common bermudagrass (Cynodon dactylon Pers. var. dactylon) in developing high‐quality interspecific [C. dactylon (L.) Pers. × C. transvaalensis Burtt‐Davy] F1 hybrid cultivars for turf use. However, the molecular basis of its morphological variation is unknown. Accordingly, the objectives of this study were to estimate the heritability and identify quantitative trait loci (QTL) associated with morphological and reproductive traits. A first‐generation self‐pollinated (S1) population of 109 individuals was evaluated for plant height (PH), leaf blade width (LBW) and leaf blade length, stem internode diameter and length, and inflorescence prolificacy (IP) in a replicated field trial over three seasons (2018–2020). The broad‐sense heritability estimates ranged from 0.31 (PH) to 0.80 (IP). Twenty‐four QTL were identified and nine of them were consistent ones. Fifteen candidate genes were found at a major and consistent QTL region associated with LBW. Frequent QTL colocations were found among morphological traits and between morphological traits and IP, partially explaining the significant correlation. The findings provide critical information and resources toward understanding the genetic basis associated with morphological and reproductive traits within C. transvaalensis and could contribute to marker‐assisted selection for breeding new turf‐type bermudagrass cultivars.

Two-stage Taguchi-based optimization on dynamically-vented blade flaps to enhance the rotor performance of a Savonius turbine

Among the vertical-axis turbine groups for small-scale wind and hydrokinetic applications, the Savonius type is considered practical due to its simple construction, easy maintenance, and good self-starting characteristics. Unfortunately, it has a poor efficiency due to the exertion of negative torques during its returning sweeps. Recently, the technique of controlled dynamic venting has been shown to reduce this negative torque on a two-bladed Savonius rotor while preserving its omnidirectional capability. That investigation was extended in this numerical study by refining the controllable flaps of the same rotor to improve its performance using a two-stage optimization procedure. In the first stage, the design parameters of the controllable flaps were optimized using the Taguchi and Analysis of Variance (ANOVA) methods. In this analysis, the flap length was found to be the most significant parameter affecting the rotor performance with a contribution ratio of 79.8%, in contrast to a ratio of only 6.7% by the least effective parameter: the flap opening angle. The first optimization stage produced an improvement of 16.7% on the average power coefficient (CP) of the vented rotor, compared to the unvented one, at the optimal tip-speed ratio (TSR) of 1.0. In the second stage, the flap length was refined further to a shorter flap of 22.5% of the blade length, resulting in an improvement of 21% on the same metric at the same TSR. Crucially, these controllable flaps only used an energy cost of 6.1% of the total energy produced by the rotor, a significant improvement from the 12.2% energy cost obtained in the previous study.

Variability Study and DUS Characterization in Kodo Millet (Paspalum scrobiculatum L.)

Variability Study and DUS Characterization in Kodo Millet (Paspalum scrobiculatum L.)

Design and Experiment of Profiling Furrow-Ridge Terrain by Cane Leaf-Chopping and Returning Machine

Design and Experiment of Profiling Furrow-Ridge Terrain by Cane Leaf-Chopping and Returning Machine