Loose Grains Research Articles

Influence of edge scour on lateral responses of monopiles with precast microbial reinforcement

Microbiologically Induced Calcite Precipitation (MICP) technology offers a promising method for stiffness reinforcement of offshore wind turbines (OWTs). However, edge scour around microbial reinforcement raises concerns about potential stiffness degradation. This study examines the effects of edge scour on the lateral responses of rigid piles reinforced with precast microbial reinforcement using a low-pH one-phase grouting method. Results from static tests, validated by numerical simulations, demonstrated that MICP technology bonded loose sand grains with the pile, forming a bio-reinforced pile with a larger diameter in the shallow soil layer, which significantly enhanced the original pile's bearing capacity and stiffness. However, edge scour reduced the embedment depth of the bio-reinforced pile, leading to a decrease in its bearing capacity and stiffness. Geometrically, protection width was found to have a relatively greater influence on stiffness and capacity compared to protection thickness. Additionally, symmetric cyclic loading tests were conducted to evaluate the effects of edge scour on backbone curves, secant stiffness, and damping ratio. Although MICP-based reinforcement notably enhanced both the secant stiffness and damping ratio of the piles, its effectiveness was completely lost once the scour depth reached the reinforcement thickness of the bio-reinforced soil block.

Separating Light Impurities from the Combed Heap in the Adapter Case

Introduction. It is possible to increase the separating of loose grain on the lattice bottom of the combine harvester feeder house by removing most of the light impurities from the combed heap using an inertial cleaning system built into the combing adapter body.Aim of the Study. The study is aimed at developing an inertial system for separating light impurities in the combing header body and optimizing its main parameters.Materials and Methods. The object of the study was a large-scale model of a pneumatic cleaning device to simulate the motion of air and components of a combed grain heap inside the combing adapter body. It was a two-factor experiment with three variations of the air flow velocity (4.5; 5.5; 6.5 m/s) and the width of the air channel (0.26; 0.29; 0.32 m). The studies were conducted on a combed heap of Moskovskaya 56 wheat with a moisture content of about 12%. As a parameter for optimization and response function, a portion of the combed heap was selected from the body of the installation with an air flow.Results. According to the results of the experimental studies, it was found that the air flow velocity has a greater effect on separating glumes than the width of the air channel. A simultaneous increase in both factors leads to an improved separation. At the same time, if increasing the air flow velocity ensures a stable increase in the proportion of the combed heap and is limited only by the air velocity at which grain appears in the combed heap along with the glumes, then changing the channel width allows achieving the parameter optimal value.Discussion and Conclusions. The use of an inertial cleaning system makes it possible to remove almost completely light impurities from the combed heap. The optimal parameters of the device are: channel width 0.28...0.3 m, air flow velocity 6...6.5 m/s.

Pollination efficiency of important insect visitors on pomegranate (Punica granatum) under mid hill conditions of Himachal Pradesh

Insect pollinators are found to be highly significant in enhancing the quality fruit production and productivity. The experiment was conducted during April–May 2020 and 2021 at Dr Y. S. Parmar University of Horticulture and Forestry, Nauni, Solan, Himachal Pradesh to determine the pollination indices of significant insect pollinators visiting pomegranate (Punica granatum L.). The data on pooled basis from two years revealed that Bombus haemorrhoidalis visited most number of flowers during the day (4.96 flowers/min) followed by Apis mellifera (4.24), Apis cerana (3.95), Apis dorsata (3.76) and Episyrphus balteatus (3.09). The time spent on each flower was maximum by A. cerana (17.10 sec/flower) followed by E. balteatus (17.04 sec), A. dorsata (14.20 sec), A. mellifera (13.07 sec) and haemorrhoidalis (5.36 sec) irrespective of different day hours. A. mellifera (5.43 bees/m2/2 min) activity was maximum followed by A. cerana (5.06), E. balteatus (2.91 visitors/m2/2 min), B. haemorrhoidalis (1.72) and A. dorsata (1.37). Data on loose pollen grains for the two years revealed that A. dorsata adhered maximum number of loose pollen grains (357.00 thousand) followed by B. haemorrhoidalis (283.00 thousand), A. mellifera (98.00 thousand), cerana (41.00 thousand) and solitary bees (28.00 thousand). A. mellifera scored highest pollination index and A. dorsata scored least pollination index. A. mellifera, A. cerana and B. haemorrhoidalis are the primary pollinators that increase pomegranate pollination efficiency whereas A. dorsata, E. baltaeatus and solitary bees are supplementary insects improving pollination in various crops including pomegranate. A. mellifera, A. cerana, B. haemorrhoidalis and A. dorsata were main foragers of pomegranate flowers ensuring effective and efficient pollination.

In-situ reconditioning mechanism for fixed abrasive pads based on the wear behavior of loose grains

C-plane sapphire (α-Al2O3) is a commonly used substrate material for integrated circuits and Light-emitting diodes (LEDs). Efficient, stable, and low-damage lapping processes are used to ensure surface smoothness and meet application requirements. Fixed abrasive pads (FAPs) are typically used for the lapping of sapphire substrates, but the pads are prone to be glazed or even failed. In this study, loose alumina grains were used for in-situ reconditioning of fixed diamond abrasive pads. The material removal rate and surface roughness of the lapped sapphire substrate were calculated, the types and size distributions of the wear debris were analyzed, the surface morphology of the FAP after lapping was examined, and an online monitoring system was used to track the friction coefficient between the FAP and the sapphire substrate. In order to determine the ideal size and concentration of loose grains and to reveal the in-situ reconditioning mechanisms for the fixed diamond abrasive pads, the effects of the size and concentration of loose alumina grains in the lapping slurry on the in-situ reconditioning of the FAP were investigated. This was done by examining the wear behavior of loose alumina grains during the lapping processes of sapphire substrates.

The influence of swirl intensity on the prediction model of wheat picking speed

AbstractTo study the effect of swirl intensity on the picking speed of wheat particles, a test bench for the transportation status of bulk grain particles was developed, and a theoretical model for the picking speed of wheat particles transported by swirl was established. Firstly, the critical conveying speed is determined through theoretical analysis and budgeted using the C&K model. Then, experiments are conducted to pick up loose grain particles in different flow fields. The particles in the swirling field are gradually rolled up from the windward end and sequentially pushed backwards to be picked up and transported. The picking speed of loose grain particles shows a trend of first increasing and then decreasing with the increase of swirling intensity. Using dimensionless swirl intensity as a variable, a predictive model for the effect of swirl intensity on particle picking speed during swirl conveying of wheat particles is derived.Practical applicationsWhen conveying bulk grain particles through a swirling flow, the intensity of swirling flow is closely related to the picking speed of bulk grain particles. This is extremely important for setting the wind speed of the conveying system, as it directly affects the energy consumption, particle crushing, and conveying efficiency of the entire system. Therefore, it is extremely important to predict the picking speed of bulk grain particles under different swirling strengths to control the corresponding wind speed. Therefore, this study conducts in‐depth research on this issue.

Development and performance evaluation of sunflower straw cellulose ether ecological sand-fixing material

Sunflowers are widely cultivated as a cash crop in the Inner Mongolia Autonomous Region, China. However, due to the lack of efficient resource utilization techniques, most of the sunflower stalks are discarded. In the Hetao irrigation area, the problem of desertification has prompted the limited use of sunflower straw to construct physical sand barriers for windbreaks and sand stabilization. In response to this, this study focuses on synthesizing a cellulose ether sand-fixing material using sunflower straw, the primary agricultural waste in Denkou County, Hetao irrigation district. This material enhances the effective adhesion between sand grains, reduces porosity among loose sand grains, and inhibits sand grain movement. The findings from this study conclusively demonstrate that the sand-fixing materials under investigation meet international standards for mechanical properties. They effectively transform loose, unconnected sand grains into a state with strong adhesion properties.

Роторный сепаратор очесанного зернового вороха в наклонной камере комбайна

Preliminary separation minimizes damage of free grain by the working parts of the thresher when stripping standing crops. For this purpose, it is advisable to use the inclined chamber of a combine harvester. The purpose of this study is to evaluate the separating ability of a rotary separator depending on its design parameters and operating mode. The research included two stages. In the first series of experiments, the distance between the rod rings was changed (6; 8; 10; 12, and 14 mm), in the second series: the peripheral speed of the rotor surface (1 to 3 m/s). Experimental studies were carried out on winter wheat of the “Moskovskaya 56” variety with a moisture content of 12%. The inclination angle of the experimental installation body in all variants of the experiment was 45°, and the supply of stripped grain heap was 1 kg/s. Based on the results of laboratory studies, it was established that the intensity of separation of free grain increases as the distance between the rod rings of the device increases and the peripheral speed of the rotors decreases. The maximum passage of loose grain (100%) corresponds to a peripheral speed of the rotors of 1 m/s and a distance between the rod rings of 14 mm. The reserves for increasing the productivity of a rotary separator are an increase in the diameter of the rotors and a decrease in their peripheral speed. When these parameters change by 30 to 35%, the transport capacity of the inclined chamber remains at an acceptable level.

Determination of tribotechnical properties of composite samples during friction on 40Kh steel

The paper presents the results of tribotechnical tests of samples of ornamental textolite (OT), ornamental structural textolite (OST) and oxafen. The influence of the surface roughness of a 40Kh steel counter-tile on the coefficients of friction from sliding speed, friction moments from pressure and jamming load from sliding speed is considered. The tests were performed on a friction machine with a vertical axis of rotation of the spindle according to the “plane-ring” scheme when the friction pair was lubricated with MGE-10A hydraulic oil. The test loads and sliding speeds were changed stepwise. It has been found that with a decrease in the surface roughness of steel counter-tiles, the friction coefficients decrease when friction occurs on polymer composite materials. OST samples had the best indicators for reducing the coefficient of friction from the sliding speed and the moment of friction from pressure, followed by OT and oxafen samples. The bully resistance of OT samples is higher than that of OST and oxafene samples. Oxsofen samples had the highest resistance to abrasive wear by loose grain, followed by OST and OT samples.

Toward Adaptive Manufacturing Development: Implementation of Artificial Intelligence for Identifying Leather Defects

Artificial intelligence was the powerful approach that was proven to be impactful for solving several problems. In the leather inspection cases, artificial intelligence also contributed some research works that effected for leather inspection process. In this research, we employed NasNet architecture conducted by using fine-tunning transfer learning method to distinguish the types of leather defects. We used 3600 images that was distributed into six classes which are folding marks, grain off, growth marks, loose grains, pinhole and non-defective. Our proposed solution successfully achieved accuracy for training data is 0.9788 with loss of 0.0198. While the maximum accuracy in validation data is 0.8059 with loss of 0.2126. In the testing data, our experiment obtained accuracy of 0.8603 with loss of 0.1603. These results indicated that our proposed solution was suitable to recognize the characteristics of leather defects and suitable to distinguish them.

Dynamics of water vapour sorption on composite LiCl/(silica gel): An innovative configuration of the adsorbent bed

Adsorption Heat Conversion (AHC) is energy and environment saving alternative to conventional compression systems. The growth of specific power of AHC systems is a prerequisite for the wider spreading of AHC. To enhance the power, an innovative adsorbent bed configuration was suggested, namely, a compact adsorbent layer prepared by gluing to heat exchanger surface ready-made grains instead of uniform adsorbent coating. The main goal was a comparative study of water sorption dynamics on loose and glued grains of a composite LiCl/(silica gel) to evaluate the power enhancement. The grains were glued to aluminium foil with various binders, both organic and inorganic, the effect of the binder nature was studied. The effective heat transfer coefficient was evaluated under typical conditions of adsorption chilling cycle. The main findings are: (a) the effective heat transfer coefficient is increased up to 1.5 times when using inorganic binders; (b) organic binders do not affect heat transfer; (c) heat transfer intensification leads to accelerating initial stage of the ad/desorption; (d) at longer times, a desorption slowdown is observed due to hindered mass transfer or LiCl crystallisation. The factors controlling the adsorption kinetics are determined and recommendations are formulated for designing innovative bed configuration.

Pollination Ecology of Rocket (Eruca vesicaria (L.) Cav. ssp. sativa (Mill.) Thell) in the Semi-Arid Environments of Northwest India: Native Bees Are the Major Pollinators

Several insect species visit the flowers of a plant to obtain floral rewards in the form of pollen and/or nectar. In return, we would anticipate that those visitors would contribute to the reproductive success of the plant. Do these visitors contribute equally towards the reproductive success of the plant? This issue has been the interest of many pollination ecologists. To find a solution to this problem, I investigated the pollination ecology of rocket (Eruca vesicaria (L.) Cav. ssp. sativa (Mill.) Thell), an important leafy vegetable used as salad. I captured the flower visitors with a hand net from the experimental field and had these identified. I also recorded the number of loose pollen grains carried on the body of the visitors of different species and deposited on the stigmas. Effects of single and multiple visits of visitors on the seed set of rocket flowers were also determined. Abundances and foraging rates of the flower visitors of this species were recorded and their values were used to calculate their respective contributions towards the reproductive success of this species. Five species of Hymenoptera, three of Diptera, one of Lepidoptera, and one of Coleoptera visited the flowers of the rocket. Apis florea was the most abundant among the flower visitors, followed by the dipterous flies, Apis mellifera, Apis dorsata, Andrena savignyi, and Andrena leaena in descending order. The number of loose pollen grains carried and deposited, foraging behaviors, foraging rates, and abundances did not provide conclusive measures to differentiate the contributions of different flower visitors towards the reproductive success of the rocket. However, the data recorded on abundances, foraging behaviors, and foraging rates together could do so. Accordingly, Andrena savignyi was the most efficient pollinator of rocket, followed by Andrena leaena, Apis dorsata, Apis mellifera, and Apis florea; dipterous flies were the least efficient pollinators of this plant species. In rocket, 28.84% of pollination was brought by Andrena savignyi, 24.69% by Andrena leaena, 20.34% by Apis dorsata, 18.37% by Apis mellifera, and 7.7% by Apis florea; dipterous flies caused only 0.06% pollination. Butterflies were very rare and Coccinella sp. was not a pollinator of this plant. Therefore, not all the pollinators of rocket contributed equally towards its reproductive success (seed production). Bees brought about 99.94% of total pollination and melittophily distinctly predominated over other pollination modes. However, among the bees, native bees together are the major pollinators in the flowers of rockets and accomplished more than 81.5% pollination. Therefore, the conservation of native bees is most important for the pollination of crops such as rockets.

Water Adsorption Dynamics on Metal-Organic Framework MOF-801: Comparative Study of Loose and Glued Grains, and Coatings.

Adsorption heat transformation and storage (AHTS) is an environmentally benign and energy-saving alternative to common compression chillers and heat pumps. The low specific power (SP) of adsorption systems is a key drawback that hinders their broader dissemination. The optimization of adsorption dynamics is a prerequisite for SP enhancement. In this work, we studied the dynamics of water vapor adsorption on MOF-801-a promising adsorbent for AHTS. For the first time, two configurations of compact MOF-801 bed, namely, grains glued to the surface of a metal support and thin adsorbent coatings, are prepared, and their porous structure is characterized. The water adsorption dynamics is compared with a common loose grains configuration. The main findings are: (a) the binder can both accelerate and decelerate the water adsorption, and its chemical nature is subject to careful selection; (b) at the initial time, heat transfer between the support and adsorbent bed controls the adsorption rate, and, at a longer time, mass transfer starts to affect it; (c) polyvinylpyrrolidone, bentonite, thermal grease, and hydroxyethylcellulose increase the heat transfer coefficients and accelerate adsorption; polyvinyl alcohol and polyaniline slow it down; and (d) for the coatings prepared with polyvinylpyrrolidone, an SP of 1.6-5.1 kW/kg can be achieved, which is about twice that for the loose grains. The new configurations can be recommended for effective but expensive adsorbents such as MOFs, and their implementation will contribute to the further spread of AHTS technology.

Surface relaxivity estimation of coals using the cutting grain packing method for coalbed methane reservoirs

Low-field nuclear magnetic resonance (NMR) has been widely used to express the pore-size distributions of conventional and unconventional reservoirs. Based on the equation 1T2=ρFs1r, the determination of the surface relaxivity ρ can help to quantitatively convert the transverse relaxation time T2 to pore radius (r). The existing calculation of ρ using NMR requires supplementary and expensive destructive or non-destructive methods, and consolidated cylinders are required as samples to be well tested. However, the operation of multiple drilling projects and the production of many drilling cuttings are barriers to making rapid measurement of the ρ value of the unconsolidated coal cuttings challenging. In this study, an NMR grain packing method is proposed using different coal grains. The surface-to-volume ratio was transformed into the ratio of the derivative of an arbitrary pore volume to its volume, and the governing NMR equation was established by considering only the NMR porosity and T2 distribution. Sphere and cubic-like models were also constructed. The results showed that the coal with different grain sizes had different relaxation responses, and the different assemblies with the same wgrain/wgrain,c also exhibited some relaxation differences, which might be affected by the diversity in grain packing patterns and grain morphology, resulting in the variation in porosity. In addition, the water film distribution on the grain surface and the soluble minerals in the coal contribute to the variation in ρ values by influencing the relaxation properties of the voids between grains and the pores in the grains. The T2 spectrum indicated that the macropores contributed the most to the porosity, owing to the loose grain packing, and the larger grains might not strictly obey the fast diffusion limit. For the sphere-like model, the ρ values of the Ji15 and Ji17 coals were in the range of 19.47–44.04 μm/s and 36.50–46.66 μm/s, respectively; whereas for the cubic-like model, the corresponding ρ values of these two coals ranged from 24.16 μm/s to 54.64 μm/s and from 45.29 μm/s to 57.90 μm/s, respectively. Finally, different methods of ρ calculation are compared, and its potential field application is discussed.

Influence of screw blades on the performance of a screw‐drive granary robot

AbstractA granary robot with screw‐drive mechanisms can perfectly adapt to a loose grain terrain. The design of the helical wheels is significant for the driving performance of this robot. Because this robot moves due to the action of the blade on the grain, the parameters of the helical blade are especially important among all factors. Therefore, to determine the effect of blades on the performance of a screw‐drive granary robot, a screw robot–corn coupling model is established based on the coupling of the discrete element method and multibody dynamics. The model can analyze the interaction of the screw wheel with the grain particles. Then a robot with two helical wheels is designed, manufactured, and tested to verify the accuracy of the coupling model. The cosimulation created with this model has good accuracy compared with the experiment, and the mean relative errors of sinkage, velocity, and slip ratio are 3.43%, 1.21%, and 13.87%, respectively. Finally, the effects of the height, axial length, helix angle, and number of screw blades on the driving performance of the robot are studied with single‐factor simulations. The trends of the torque, slip, and drawbar efficiency varying with these parameters of the screw blade are obtained, which can provide critical insights for the preliminary design of a screwed granary robot.

Abrasive Wear Resistance of Ultrafine Ausferritic Ductile Iron Intended for the Manufacture of Gears for Mining Machinery.

The purpose of this study was to experimentally determine the abrasion wear properties of ausferritic ductile iron austempered at 250 °C in order to obtain cast iron of class EN-GJS-1400-1. It has been found that such a cast iron grade makes it possible to create structures for material conveyors used for short-distance transport purposes, required to perform in terms of abrasion resistance under extreme conditions. The wear tests addressed in the paper were conducted at a ring-on-ring type of test rig. The test samples were examined under the conditions of slide mating, where the main destructive process was surface microcutting via loose corundum grains. The mass loss of the examined samples was measured as a parameter characteristic of the wear. The volume loss values thus obtained were plotted as a function of initial hardness. Based on these results, it has been found that prolonged heat treatment (of more than 6 h) causes only an insignificant increase in the resistance to abrasive wear.

Analisis Kerusakan Jalan menggunakan Metode Asphalt Institute

Pavement is a hard layer of skin (surface) that is placed on a soil formation after the completion of earthworks, or it can also be defined as a structure that separates the wheels of the vehicle from the subgrade. Road damage is a condition where the structural and functional roads are no longer able to provide optimal service to the traffic that crosses the road. Claret road, which is located in East Penfui Village, Kupang Regency, is the main route that connects several hamlets in East Penfui Village, namely hamlets 3, 4 and 5. Within these hamlets there are densely packed housing. Damage is starting to appear on this road from Sta 0–Sta 800. Visible damage includes longitudinal cracks, crocodile skin cracks, curling, loose grains, holes, poor drainage, and low quality of driving comfort. Using the asphal institute method, an average condition value of 54.86 was obtained, requiring additional types of patch and layer handling.

Preventing Enzymatic Damage to Hides by Timely Inhibition of Trypsin Activity with Soybean Flour during Bating Process

Enzymatic bating is important for producing clean, soft, and high-yield leather. However, it is prone to cause damage to hide collagen fibers and result in loose grain or damaged grain surface due to the longer enzymatic hydrolysis time of the grain layer than the middle layer caused by the slow mass transfer and the rapid hydrolysis reaction of the bating agent in hide. Considering trypsin is the most common bating agent, soybean flour (SF) that contains environmental friendly Kunitz trypsin inhibitor (KTI) was used after delimed hides were treated with trypsin for a certain time to opportunely inhibit its activity in the grain and avoid bating defects. The fluorescence micrographs of hides bated with fluorescently labelled trypsin and KTI showed that KTI could cover only the surface layers when it was added after bating for a certain time, whereas trypsin could penetrate the hide completely. When sufficient SF was added to the bating float at 2 h, the damage to hide collagen caused by trypsin was effectively reduced. In particular, the grain surface remained intact after bating for 8 h. The decrease in the strength of leather caused by bating was also reduced. In addition, the usage of SF scarcely affected the fiber dispersion of the middle layer, thereby ensuring the softness of leather. In summary, opportunely inhibiting the activity of trypsin in the grain could prevent hide damage and improve the quality of leather.

STUDY OF THE PROPERTIES OF RAPESEED AS A DRYING OBJECT

The study of the properties of rapeseed as an object of drying involves knowledge of physico-mechanical, hygroscopic, chemical and thermophysical, characteristics. The physico-mechanical properties of seeds include: size and shape, aerodynamic properties, surface condition, specific gravity, porosity and flowability of the grain mass, packing density of the grain mass, bulk and absolute weight, color, hydraulic resistance. The chemical and mineral composition of rapeseed was analyzed, it is rich in oil content (40-45%), proteins (25-26%), and also rich in potassium (979 mg) and phosphorus (840 mg).Hygroscopic characteristics include studies of the equilibrium humidity of rapeseed under the influence of relative humidity and air temperature. The need to dry rape to 8% reduces biochemical processes in the middle of the material, which improves the quality and does not spoil the seeds. Thermophysical characteristics increase with an increase in the temperature of the coolant and the moisture content of rapeseed. Formulas for calculating the specific heat capacity and thermal conductivity coefficient of rapeseed from the humidity of the material and the temperature of the heat carrier are given. To determine the qualitative characteristics of rapeseed, a method of determining biochemical parameters is presented. Determining biochemical indicators such as germination and germination energy of rapeseed before and after drying allows finding rational regimes. Determined factors of intensification during drying of rapeseed are as follows: increase in driving force, increase in kinetic coefficients, increase in the contact surface of the grain with the coolant. An increase in driving force due to an increase in the difference in moisture content and temperature of the coolant and grain. An increase in the kinetic coefficients is achieved due to an increase in the coefficients of heat transfer, thermal conductivity and drying. An increase in the contact surface of the grain with the coolant is possible due to the activation of the surface and the creation of a loose, pseudo-liquefied or suspended grain layer.

Super hard and brittle material removal mechanism in fixed abrasive lapping: Theory and modeling

Currently, the problems of inefficient fixed abrasive lapping (FAL) for super hard and brittle material wafers (such as sapphire) with fixed abrasive pads (FAPs), restrict the development of the semiconductor industry. Most importantly, the mechanisms of FAL processes are still unclear, often analyzed based on the theoretical models of chemical mechanical polishing (CMP). However, the material removal models of CMP are specific to loose abrasives, do not effectively apply to the lapping processes for super hard and brittle material wafers with a FAP. In this paper, the spherical crown model modified by elastic-plastic mechanics and brittle-plastic transformation mechanism was applied to super hard and brittle material removal mechanism in FAL processes. In consideration of the influences of the yielding abrasives embedded in the FAP matrix and the matrix surface topography on the wafer-pad contact, a material removal model suitable for super hard and brittle material wafers lapped by FAPs was obtained. The loads applied on the fixed abrasives and the matrix asperities during the elastic-plastic-brittle deformation processes of wafers were analyzed, respectively. The model indicates that the back-off of the abrasives embedded in the FAP matrix intensifies along with the decrease of the matrix hardness and the increase of the abrasive size, respectively. The penetrating depth of the fixed abrasive can be raised by increasing matrix hardness, applied pressure, abrasive size, and decreasing abrasive number, as same as the elastic recovery of the super hard and brittle material slid by the abrasive after unloading. The pad matrix surface dressed by loose grains greatly affects the MRR of wafers. The predicted MRR of sapphire wafers based on the FAL model is consistent with experimental data. Finally, the keys to improving the processing efficiency of super hard and brittle material wafers are clarified in detail.

Abundance, foraging behavior and pollination efficiency of insects visiting the flowers of Aonla (Emblica officinalis)

Many insect species visit the flowers of a plant and play an important role in their pollination. Of late, the interest of the pollination biologists has been to determine their relative contribution towards the reproductive success of the plant. Such information is lacking on the pollinators of Aonla (Emblica officinalis Gaertn.), a plant of very high nutritive and medicinal importance. Therefore, let’s attempt to make this study to generate such information on this plant. The study was conducted on three varieties of Aonla (viz. Chakaiya, NA-7 and NA-10) for two years. An entire range of flower visitors of this fruit plant was captured with hand net from its field during its flowering period and were identified. On the basis of foraging mode, the flower visitors were characterized as pollinators and non-pollinators. Their abundances, foraging rates, activity durations and number of pollen grains carried on the surface were recorded, and these parameters were used to determine their relative contribution towards the reproductive success of this plant. Among the 12 insect species visiting the flowers of Aonla at the study site, 5 belonged to Hymenoptera, 6 to Diptera and one to Lepidoptera. Apis dorsata was the most abundant visitor having maximal foraging rate and carried maximal number of loose pollen grains, followed by A. mellifera, A. florea and Sarcophaga sp; other visitors had lesser values of these parameters. On the basis of these parameters, melittophilous mode of pollination was found to predominate in Aonla. However, the plant was found to be benefitted from the multispecies pollinator guild, and the pollinator diversity seemed to matter for maximization of pollination in Aonla. Therefore, there is a dire need to conserve the pollinator diversity