Design and Performance Validation of a Variable-Span Arch (VSA) End-Effector for Dragon Fruit Harvesting

The Sea Ice Mechanics Initiative (SIMI) is a five-year U. S. Navy Office of Naval Research (ONR) program. The main SIMI field experiment was in the Beaufort Sea from September 1993 through April 1994, with numerous other small field experiments, laboratory experiments, and modeling efforts. The goals of this program are to understand sea ice constitutive laws and fracture mechanics over the full range of geophysical scales, to determine the scaled responses to applied external forces, and to develop physically-based constitutive and fracture models. About twenty principal investigators are working to achieve these goals along with their associates. The SIMI experiments include ice stress, strain, strength, tilt, motion, temperature, and response to controlled load experiments. This work will provide new ice information for loads on structures and for Arctic operations, both private and government. INTRODUCTION The goals of the Sea Ice Mechanics Initiative (SIMI) Arctic research program are stated in the SIMI Summary Plan (Curtin,1993), These are:Understand sea ice constitutive laws and fracture mechanics over the full range of geophysical scales and determine the scaled responses to applied external forces.Develop physically-based constitutive and fracture models. These goals were developed at the Sea Ice Mechanics Workshop (Curtin, 1991), along with an assessment of the limits of current understanding, a list of priority research issues, and state-of-the-art methods for the many aspects of sea ice mechanics. Individual projects within the program were defined around the scale size used in the ice mechanics work. This paper describes SIMI, focusing on the field program initiated in September 1993. BACKGROUND The Office of Naval Research held a Sea Ice Mechanics Workshop at Airlie, Virginia on November 12-14, 1990, where sea ice mechanics was examined from different perspectives, both methodological (theoretical modeling, laboratory experiments, and field observations) and behavioral (material, structural, and acoustical aspects). The Workshop proceedings (Curtin, 1991) outline limits of current understanding, prioritizes research issues, and documents innovative methods of approach. The workshop participants included representatives from government agencies and laboratories as well as from universities, the oil industry, and other private sector engineers and scientists. The Workshop Proceedings were used to shape the five-year (1992-96) SIMI program. ONR sponsored another workshop at Dunsmuir Lodge, Sidney, British Columbia, Canada on October 12-14, 1992 (Curtin, 1993). During this workshop, the detailed plan for SIMI was worked out. The main field experiment included a drifting camp in the Beaufort Sea collecting data from Fall 1993 through Spring 1994. The SIMI plan and the field program are described below in a quote from Curtin (1991). "A major question in understanding and predicting the mechanical behavior of Arctic sea ice involves the effect of size on the dynamics. The notion that the scales of a specimen alone influences the operative physics has fundamental implications."

This paper presents an H-shaped piezoelectric stack energy harvester designed to capture energy from track vibrations between railway sleepers. The harvester achieved an impressive maximum output power of 29.64 mW, demonstrating the efficient conversion of mechanical energy into electrical power. At a frequency of 3Hz under a load of 8kN, the optimal performance was achieved with an external resistance of 550 kΩ. In the impact load test with an energy of 3J, 54 LEDs were lit up, demonstrating its potential for wireless sensor applications. The performance of the harvester was validated through theoretical modeling, finite element analysis, and experimental testing. This energy harvester provides a reliable power source for wireless sensors used in monitoring railway systems, enhancing track safety and maintenance. The developed harvester offers an effective solution for energy harvesting in railway environments.

A field experiment using 5 treatments viz., T1 -Dark blue polythene mulch, T2 - Light blue polythene mulch, T3-Black polythene mulch, T4 -Paddy straw mulch and T5 – control was conducted to investigate the impact of various types of mulch material on growth, yield, and quality of Summer Squash (Cucurbita pepo L.) Cv. Pusa Alankar under the valley conditions of Srinagar Garhwal. The experiment was laid out in a randomised complete block design with five replications. The effect of mulching materials on almost all the growth, yield, and quality parameters under study was found to be statistically significant. The results revealed that the treatment T2 had maximum plant height (81.33 cm) and plant spread (61.12 cm) at harvest. It also showed the maximum collar diameter (1.92 cm) and the minimum days taken for the appearance of the first female flower (30.29 days). Moreover, it exhibited a higher fruit setting percentage of 78.52%, the minimum days taken to the first fruit harvesting (41.28 days) and the maximum number of fruits per plant (7.38), average fruit length (25.26 cm), and yield per plant (3.46 kg). In contrast, the treatment T4 resulted in the maximum plant height at 15 DAT (21.21 cm), average fruit weight (484 g) and fruit diameter (4.68 cm). On the other hand, treatment T1 demonstrated significant effects in terms of plant height at 45 DAT (46.73 cm), plant spread at 30 DAT (32.08 cm), and the number of harvestings (5.05). The experimental findings were diverse, with each treatment showing its influence on different parameters. However, considering the results, the treatment T2 - Light blue polythene mulch appears to be the most suitable option for enhancing the production of summer squash under the valley conditions of Srinagar Garhwal.

The field experiment was conducted in the shade net house at National Seed Project, Department of Horticulture, College of Agriculture, SKRAU, Bikaner during kharif season 2024. The experiment comprised nine treatment combinations, each replicated three times. It was laid out in randomized block design with three levels of inorganic fertilizers (Control, 50% NPK and 100% NPK) and two treatments of organic manures (Wool waste @ 10 t/ha and Vermicompost @ 10 t/ha). The experimental results revealed that the treatment T9 (NPK-100% + 10t/ha wool waste) gave significant maximum results in growth parameter viz; vine length at final harvest (3.59 m), no. of primary branches per vine (6.42), days to first flower initiation (32.10), days to first fruit set (35.01), days to first fruit harvest (42.87) and per cent fruit set (94.46%) yield and yield attributes viz; number of fruits per vine (12.88), fruit length (17.88 cm), fruit diameter (4.58), weight of fruit (138.99 g), number of pickings (7.12), fruit yield per vine (1.79 kg) fruit yield per plot (53.47 kg) and fruit yield per hectare (59.60 t/ha).

We investigated the relationship between the elastic modulus, G and the reaction probability, p for polymer networks. First, we pointed out that the elastic modulus is expressed by G = {(fp∕2 - 1) + O((p - 1)(2))} Nk(B)T∕V (percolated network law), which does not depend on the local topology of the network structure or the existence of the loops. Here, N is the number of lattice point, V is the system volume, f is the functionality of the cross-link, k(B) is the Boltzmann constant, and T is the absolute temperature. We also conducted simulations for polymer networks with triangular and diamond lattices, and mechanical testing experiments on tetra-poly(ethylene glycol) (PEG) gel with systematically tuning the reaction probability. Here, the tetra-PEG gel was confirmed to be a potential candidate for ideal polymer networks consisting of unimodal strands free from defects and entanglements. From the results of simulations and experiments, it was revealed, for the first time, that the elastic modulus obeys this law in the wide range of p (p(c) ≪ p ≤ 1), where p(c) is the reaction probability at gelation threshold.

The effect of the extent of polymerisation of a slag structure on the strength of alkali-activated slag binders

Cable yarding systems constitute an adapted solution for steep-slope harvesting in mountain forests. However, it requires many specific skills for both forest managers and operators. The objectives of this research were to: (1) develop a CableHelp model for the set-up of cable yarding systems where inputs are operational field data and outputs are load path and tensile forces, and (2) to validate it with field experiments. The results show a high accuracy between the data predicted by the model and field measurements. Furthermore, this work stresses the importance of taking into account both the mainline effect and the friction between skyline and intermediate supports to properly calculate the skyline tension and load path. The CableHelp model shows great adaptability and ensures highly accurate predictions for any position on the line profile and for different configurations: single-span or multiple-span profiles, uphill or downhill yarding and for different kinds of carriage. A direct application of this research is to optimize the set-up of cable lines in order to reduce equipment wear, as well as operating cost, while respecting operator safety.

In this report, we have studied graft compatibility of five scion cultivar Pusa Shyamala, Pusa hybrid -6, Pusa Kranti, Mahy 80 and Gopi 75 when grafted onto Kavach and CO2. As per data two scion, Mahy 80 and Gopi 75 when grafted on Kavach and CO2 showed maximum graft success from 82 to 88%. Moreover, in field experiment was having six treatments i.e. Mahy 80 grafted on Kavach, Mahy 80 when grafted on CO2, Gopi 75 grafted on Kavach, Gopi 75 grafted on CO2, Mahy 80 (non-grafted), Gopi 75 (non-grafted) with five replications. Among all treatments graft combination of Mahy 80 onto Kavach significantly enhanced plant height of 33.13, 56.84 and 78.07 cm at 30, 60 and 90 DAT respectively. Similarly, Mahy 80 onto Kavach reported maximum number of branches per plant, average fruit weight (153.14 g), fruit yield per plant (1.50 kg plant-1), fruit yield per hectare (41.75 t ha-1) while earliness in terms of days to first harvest (67.24 days) and maximum number of fruits per plant (13.13) was reported in Gopi 75 grafted onto Kavach. Therefore, we claim that for Mewar region scion Mahy 80 onto Kavach rootstock will be suitable grafted seedling of brinjal.

Thermal environment analysis in large-diameter SPB shield considering the coupling heat transfer effects of slurry heat transfer and ventilation system

Because of the unclear understanding of the characteristics associated with coupled rock breaking using multiple water jets, a numerical model combining smoothed particle hydrodynamics (SPH) and the finite element method (FEM) was established to investigate the rock-breaking capacity of a high-pressure, double-stranded water jet structure. The effectiveness of this model was verified through field experiments. The study further examined the specific energy required for rock breaking using the high-pressure double water jets and analyzed the effects of jet pressure, nozzle diameter, jet impact angle, and impact point spacing on rock-breaking volume. The results demonstrate that the rock-breaking ability of a high-pressure double water jets is better than that of a single water jet. When the impact angle of the high-pressure double water jets was 15° and the distance between impact points was 2.0 d, the rock damage effect was the best. By comparing the specific energies for rock breaking of a single water jet and a double water jet, it was concluded that the best rock-breaking nozzle diameter is 1.6 mm. Furthermore, an orthogonal testing approach was employed to determine the main and secondary factors influencing the rock-breaking energy of the high-pressure double water jet. The order of significance was found to be jet pressure > impact angle > impact point spacing > nozzle diameter. These findings provide valuable guidance and reference for application in the coal mining industry.

Despite two centuries of research, the mechanisms underlying the formation of species’ elevational range limits remain poorly understood. The climatic variability hypothesis highlights the role of climatic conditions in shaping species’ thermal tolerance and distribution ranges, while the species interactions–abiotic stress hypothesis underscores the relative importance of biotic factors and abiotic stress along environmental gradients. We emphasize Darwin's perspective on the ubiquity of interspecific competition across climatic gradients and the importance of understanding how climate modulates biotic interactions to shape species distributions. Niche theory provides a comprehensive framework, combined with empirical research, to explore how environmental gradients influence species traits, leading to context-dependent species interactions that constrain distributions. In particular, the application of the concept of environmentally weighted performance can further elucidate these complex ecological mechanisms. Future research should integrate multiple approaches, including field and laboratory manipulative experiments, theoretical modeling, and interdisciplinary collaboration, to improve our understanding of species distributions in mountain regions and to inform biodiversity conservation strategies in the face of rapid environmental change.

A common theme in recent social psychology research studies is the testing of laboratory-derived theories and mechanisms in so-called ecologically valid settings (that is, in field experiments). Stapel and Lindenberg (p. [251][1]) show that environmental signs of disorder, such as uncollected trash

Properties of block copolymers were studied by SALS, dynamic mechanical testing, DSC, and stress-strain and dichroism experiments. Crystallization of hard segments provides a superstructure for the elastomer phase consisting of uncrystallized hard and soft segments.

ABSTRACTPrevious studies on vegetation–flow interactions have underestimated the morpho‐biomechanical complexity of riparian plants. By integrating mechanical testing and flume experiments, the study deciphered the morpho‐mechanical adaptations of Myricaria laxiflora (a Three Gorges riparian shrub) across its dormant period, early growth period, and growth boom period, while analysing the flow structure responses in the wake area. Biomechanically, stem stiffness showed minimal variation between the dormant and early growth periods, but the bending modulus increased twelvefold during the growth boom period. Aquatic morphological changes were jointly determined by frontal area and mechanical properties: Under maximum flow rates, the greatest bending occurred during the early growth period, followed by the dormant period and then the growth boom period. From the dormant to growth boom periods, the vertical frontal area expansion zone shifted from regions distal to the bed to areas adjacent to the bed, causing a corresponding descent in velocity inflection points within downstream mean velocity profiles. During early growth and growth boom periods, the development of small leaves and lateral branches enhanced frontal area, but elevated flow rates triggered vegetation reconfiguration, thereby weakening overall flow resistance. Turbulence analysis revealed spatially expanded sweep dominance during the growth boom period, intensified ejections and vortices at shear boundary layers lateral to vegetation, amplified inward/outward interactions linked to lateral branch growth, small and dense leaf morphology promoting turbulence dissipation, flexible stems homogenising wake flow and stabilising vortical structures.

Design and control of an apple harvesting robot