Increase In Feed Rate Research Articles

DESIGNING, FABRICATION AND PERFORMANCE EVALUATION OF AGRICULTURAL COMPOSTER FOR ECONOMICAL BIOWASTE MANAGEMENT

In the last few years, the rapid increase of human population are creating many environmental problems because of intensification of human activities. A huge amount of wastes are generated from industries including food and agriculture industries. It is essential to protect the natural resources. It can be done with best management practices of agriculture waste in future Composting is the best method to handle the food, agricultural and industrial waste. The main objective of this research is the design and fabrication of an indigenous composter to conserve the agriculture waste. Composter structure is based on two shells. One is inner shells which is having diameter of 48 inches and outer shell having diameter of 52 inches. Between these two shells heat in the form of steam is circulated to give high temperature for pasteurization of compost. Raw material is added in the inner shell. Two gears are attached with this composter structure. One is driving gear which is also small gear attached with motor. Other one is larger gear which is adjusted according to our desire RPM requirement. Larger gear further rotates the shaft present in the inner shell of composter. Gear motor is used having the power of 3355 Watt Watt. Material used for this composter was mild steel. A boiler was attached to this composter to flow the steam in outer shell of composter. Agriculture waste considered for this research corn straw waste. The analysis have been done in a composter for compost effecting parameters. The effect of three independent parameters pressure, RPM and feeding rate was analyzed on the composting time of waste. Results indicated that increase in the RPM the time of composting also increase because of oxygen cannot consumed fully at higher RPM. Whereas the increase in feeding rate decrease the time of composting because the greater number of microbial activities generated in the composting process and compost prepared in less time. In case of pressure, higher the pressure the time of composting decreases because at higher pressure the time rise quickly and thermophilic conditions occurs quickly. At RPM 12 and feeding rate 15kg in 62.89± 2.26 time compost was prepared it was the least time as compare to others. At 10 RPM and 1 bar pressure composting time notice was 65.33±2.60. In combination of feeding rate and pressure, at feeding rate 15kg and pressure 0.5 bar least time noticed 63.00± 2.35.

Experimental study on machining properties of a high-strength composite material with Ti-555 titanium alloy matrix

Targeted at a composite material with a novel Ti-555 high-strength titanium alloy matrix developed using the method of "reinforcement wet grinding-spark plasma sintering-heat treatment", a study is conducted on the machining performance during the machining process. Orthogonal experiment method, single factor experiment comparison method and empirical model analysis method are adopted to explore the pattern of changes in cutting force, surface roughness and the wearing of cutting tools under different parameters. There are a number of points revealed by the experimental results as follows. In the machining process, due to the high-strength and hardness of the composite material with Ti-555 high-strength titanium alloy matrix, the selection of machining parameters is limited, and the highest machining speed reaches up to merely 45 m/min. Most affected by the depth of machining, the cutting force increases as machining depth and feed rate are on the rise. The empirical model of cutting force is constructed using the least square regression method, the level of significance is high as indicated by the F test method. and feed rate will make difference to surface roughness. Not only will a greater feed rate increase roughness value, it will also aggravate the wearing of the tool.

Elucidating energy requirements for size reduction of malted maize, soybean and sorghum milling using attrition mill

• High energy efficiency was achieved using attrition mill for grinding malted maize, sorghum and soybean. • Size reduction of malted maize, sorghum, and soybean depend on germination duration and feed rate. • Malted sorghum consumed lowest energy for size reduction while soybean was the highest. • Feed rate of 0.4 kg/h and germination duration of 72 h were most appropriate for malted maize, sorghum, and soybean milling using attrition mill. Malting involves controlled crop steeping, germination and kilning. Energy consumption patterns of milling malted maize, soybean and sorghum grains using attrition mill were investigated. The crops were conditioned to sprout for 24, 48, 72 and 96 h and dried at 60 °C for 18 h. Malted products were fed separately into attrition mill at 0.2, 0.4, 0.6, 0.8 and 1.0 kg/min. Inlet temperature of feed and machine parts, outlet temperature of flour produced and quantity of fuel consumed were recorded in each case. Standard equations were used to quantify energy input, intensity, output and efficiency, exergy loss and destruction. Energy input for milling malted crops germinated for 24, 48, 72 and 96 h respectively ranged from 0.283 to 0.881 MJ, 0.228–0.567 MJ, 0.193–0.578 MJ and 0.186–0.555 MJ for maize; 0.194–0.45 MJ, 0.254–0.379 MJ, 0.153–0.342 MJ and 0.184–0.36 MJ for sorghum, and 0.176–0.661 MJ, 0.373–0.562 MJ, 0.169–0.683 MJ and 0.189–0.617 MJ for soybean. Energy outputs increase with increase in feed rate. Energy utilization efficiencies of the operation ranged from 70.13 to 88.23% for maize, 71.90 to 91.94% for sorghum and 68.88 to 84.99% for soybean. Exergy loss and destruction of the malted crops were significantly different at p < 0.05. This study revealed that energy requirements for size reduction of malted maize, sorghum, and soybean depend on germination duration and feed rate. Attrition mill was appropriate for grinding malted maize, sorghum and soybean, and feed rate of 0.4 kg/h was recommended.

3D FE modeling and experimental analysis of residual stresses and machining characteristics induced by dry, MQL, and wet turning of AA6061-T6

The present research study aimed to investigate the influences of turning environments and parameters on machining temperature (MT), machining forces (MFs), and axial surface residual stresses (ASRS) in turning operation of AA6061-T6. Turning environments included DRY, minimum quantity lubrication (MQL), and WET modes, and turning parameters consisted of cutting speed (), feed rate (), depth of cut (), tool nose radius (), side cutting edge angle (SCEA), and back rake angle (BRA). A 3D finite element (FE) model was developed to predict MT, MFs, and ASRS for different turning environments and parameters and was validated by experimental measurements. The results showed that increasing feed rate led to a higher tensile ASRS while using tools with a nose radius of 0.4 resulted in lower ASRS. In addition, the deviation of SCEA from 0° to positive or negative values caused higher tensile ASRS. ASRS increased with decreasing BRA from 0° to –15°. The variation of ASRS was found to be more sensitive to thermal effects than to mechanical ones. The results further confirmed that in a turning process, the competition between the machining forces and temperature was the fundamental factor that determined the extent of residual stresses.

Kinematics characteristics of the flip-flow screen with a crankshaft-link structure and screening analysis for moist coal

The flip-flow screen is an effective solution for the screening of high-water and fine materials. In this study, a flip-flow screen with crankshaft-link structure (FFSCLS) was proposed, and kinematic model governing the vibration of the screen are also presented. Kinematics characteristics of the FFSCLS was obtained using vibration experiments and analysis unit, and the classification performance under different operational conditions were studied by the screening experiments and analysis system to reveal the mechanism of deep screening about moist fine coal. The results show that the vibration experiment result of the flip-flow screen can be fully described by the kinematic model with the maximum deviation was within 6.84%. The moving directions of the outer and the inner screen boxes are opposite and the phase difference is 180° along X -axis. The trajectories of the outer and inner screen boxes are approximate ellipse. The acceleration amplitude along X -axis of the inner and outer screen boxes reached 9.8 and 16.2 m∙s−2 with rotational speed of the driving motor n of 575 r∙min−1. The rotational speed n showed significant influences on the kinematics and screening efficiency of the FFSCLS. The vibration of the outer screen box increases rapidly while that of the inner screen box increases slowly with the increase of n. in addition, with the increase of the rotational speed of driving motor n, the screening efficiency first increased and then decreased. With the increase of feeding rate Q, the screening efficiency gradually decreased. It was found that the screening efficiency was higher than 85.82% when n = 575 r∙min−1, and Q ≤ 3 kg∙s−1. This indicated that the FFSCLS has excellent performance for moist coal screening.

Physiological Mechanisms of Variable Nutrient Accumulation Patterns Between Diapausing and Non-Diapausing Fall Webworm (Lepidoptera: Arctiidae) Pupae

Diapause is a highly advantageous strategy for winter survival for insects living in temperate environments. However, insects typically do not feed during diapause and are therefore presented with a complicated energetics problem. The fall webworm, Hyphantria cunea, overwinter as diapausing pupae, but adults of this species lose their ability to feed due to the degeneration of their mouthparts. Thus, the energy reserves stored before diapauses contribute to the survival rate and fitness of the adults after emergence. In this study, we tested the hypothesis that diapause-destined larvae of H. cunea reserve more energy by increasing feeding rate, feeding efficiency, or both, during the diapause preparation phase compared with non-diapause-destined larvae. We observed higher digestive efficiency, increased lipase and amylase activity, and lower protease activity in diapause-destined larvae compared to non-diapause-destined larvae. These differences in digestive physiology during diapause preparation lead to greater body size and mass, increased lipid and carbohydrate content, and lower soluble protein content in diapausing pupae, relative to non-diapause pupae - results consistent with our hypothesis. We conclude that diapause-destined fall webworm reserve more energy than non-diapause-destined individuals by increasing feeding efficiency, and that this increase in efficiency is at least partially driven by increased lipase and amylase activities in the midgut. This is in contrast to non-diapause-destined larvae, which likely reserve greater protein than diapause-destined larvae to help maintain their physiological function.

Dietary oxidized fish oil negatively affected the feed utilization, health status and fillet quality of juvenile Amur sturgeon, A. schrenckii

This study was carried out to explore the effects of dietary oxidized fish oil on growth, feed utilization, health status and fillet quality of juvenile Amur sturgeon (A. schrenckii) (initial mean body weight = 70.0 ± 0.02 g). An 8-week experiment with diets containing 6% fresh fish oil (FFO) or 6% oxidized fish oil (OFO) was conducted. The peroxide values (POV) of fresh and oxidized fish oil were 9.14 and 384.73 meq/kg, respectively. The results indicated that compared to the FFO group, dietary OFO had no significant influence on growth (P > 0.05), but increased feeding rate (FR) and decreased productive protein value (PPV) significantly (P < 0.05). The fish in the OFO group had lower serum high-density lipoprotein cholesterol (HDL-C), albumin (ALB), and the ratio of ALB to globulin (GLOB), and higher serum malonaldehyde (MDA) and superoxide anion free radical (O2−) than those in the FFO group (P < 0.05). OFO induced inflammatory cell infiltration in the liver, and the expressions of hepatic inflammatory cytokines were significantly up regulated in the fish fed with OFO (P < 0.05). The fish in the OFO group showed abnormal yellow skin, and the yellowness value of the dorsal muscle was significantly elevated in comparison with the FFO group (P < 0.05). The contents of muscle protein, lipid, and glycogen were significantly declined by dietary OFO (P < 0.05). Dietary OFO affected the muscle essential amino acid (EAA) composition remarkably, among which the proportions of Ile and Met were reduced while Leu was promoted significantly (P < 0.05). The fish fed with OFO had significantly higher n-6 polyunsaturated fatty acids (PUFA) proportion and n-6 PUFA/n-3 PUFA ratio (P < 0.05) than the fish fed with FFO, but there were no changes in the proportion of saturated (SFA), monounsaturated fatty acid (MUFA) and n-3 PUFA (P > 0.05). The total free amino acid (FAA) was enhanced significantly by dietary OFO, but the delicious amino acid (DAA) proportion was decreased in the muscle of the fish fed with OFO (P < 0.05). In summary, dietary OFO had no significant influence on growth, but decreased feed utilization of Amur sturgeon. Dietary OFO impaired the health status of Amur sturgeon by inducing oxidative stress, lowering serum HDL-C, ALB and causing liver damage. Dietary OFO adversely affected the fillet quality of Amur sturgeon by altering body color, muscle proximate composition, glycogen content, EAA, fatty acid and FAA profiles.

Low and High Speed Orthogonal Cutting of AA6061-T6 under Dry and Flood-Coolant Modes: Tool Wear and Residual Stress Measurements and Predictions.

The present research work aimed to study the effects of cutting environments and conditions on tool wear and residual stresses induced by orthogonal cutting of AA6061-T6. Cutting environments included dry- and flood-coolant modes and cutting conditions consisted of cutting speed and feed rate. A 2D finite element (FE) model was developed to predict tool wear and residual stresses and was validated by experimental measurements including machining forces, tool wear, and residual stresses. This was obtained by exploring various magnitudes of the shear friction factor and heat transfer coefficient and choosing proper coefficients using the calibration of the predicted results with the measured ones. The experimental results showed that the effect of cutting environment including dry and flood-coolant modes was negligible on machining forces. The experimental investigation also demonstrated that increasing feed rate raised machining forces, tool wear and residual stresses in both cutting environments. Low Speed Cutting (LSC) led to the highest value of tool wear and High Speed Cutting (HSC) provided the lowest values of resultant machining forces and residual stresses in both modes. Flood-coolant mode reduced tool wear and slightly decreased tensile residual stresses in comparison with dry mode. As a result, low feed rate and high-speed cutting under flood-coolant mode were proposed in order to improve tool wear and residual stress in orthogonal cutting of AA6061-T6.

An Investigative Study into the C. flumenia and its Interactions with its Surrounding Ecosystem

his research focused on the physical characteristics of Corbicula flumenia, an invasive species of clam found in the American River, and how these characteristics give it a possible survival advantage over native clam species of the river. Clams were collected from the American River and dissected, while river water and soil samples were also collected. The water and soil were analyzed for levels of coliforms such as E. coli, since this could be a food source that gives the Asian Clam an advantage over native species. The Asian clams were analyzed for their feeding efficiency of E. coli compared to algae and also compared for anatomical differences to the native species by measuring cirri size, which could increase feeding rates within these clams, giving them a competitive edge over their native competitors. It was found that there was much E. coli in the water and soil, but no significant correlation was found between clam cirri size and feeding rate. The Asian clam’s DNA and protein expression was analyzed for genetic mutations that contribute to the species’ invasive advantage.

Effects of the Feeding Rate on Growth Performance, Body Composition, and Hematological Properties of Juvenile Mandarin Fish Siniperca scherzeri in a Recirculating Aquaculture System

The effects of feeding rate (0.5%, 1.0%, 1.5%, 2.0%, 2.5%, and 3.0% body weight [BW] per day [BW day−1]) on the growth, body composition, and blood properties of juvenile mandarin fish, Siniperca scherzeri, (initial BW 18.4 ± 0.2 g) were investigated in a water recirculating aquaculture system. Triplicate groups of fish were fed an experimental diet (55.4% protein, 14.1% lipid) for 10 weeks. Weight gain and specific growth rate increased with increasing feeding rates of up to 2.5% BW day−1, after which no significant increase in growth was observed. Feed efficiency, protein efficiency ratio, and protein retention were not significantly different among the fish fed 1–2.5% BW day−1 but decreased significantly in those fed 3.0% BW day−1. The lipid content of fish fed 2.5% BW day−1 was significantly higher than that at 0.5–1.5% BW day−1. The total plasma cholesterol content was significantly lower in fish fed 0.5 BW day−1 than fish provided with other feeding rates. Based on the growth, feed efficiency, body composition, and blood content analyses, including regression analysis, the optimal feeding rate for juvenile S. scherzeri weighing between 18 g and 54 g was estimated at 1.88–2.80% BW day−1 depending on weight gain, specific growth rate, and feed efficiency under 26.9 °C conditions.

Experimental Investigation of Tool Wear in Machining of SiC Based Al-MMC

ABSTRACT The machining of hard particle reinforced metal matrix composite material is always challenging. The machining behaviour of aluminium-based metal matrix composites (Al-MMCs) can be entirely different from conventional materials. This paper presents an experimental study of the effect of cutting parameters like cutting speed on surface quality and tool wear. Even the matrix material can be ductile, but hard particles and their binding with matrix material can bring a difference in the machinability of composite materials, specially MMCs. Three different MMC compositions, i.e. MMC reinforced with 15%, 20% and 25% SiC, were machined at various cutting speeds and feed rates. Tool wear and surface roughness of the machined surface of MMC were examined. Increased content of SiC increases the mechanical properties like hardness and compressive strength but was found detrimental to tool and surface quality. Tool wear was found increasing with both increasing feed rate and cutting speed. Application of image processing for measurement and prediction of tool wear is attempted by capturing the images of tool insert and processing using a MATLAB® based algorithm. Results are in line with many other research and establish the scope of future work for non-contact measurement of tool wear in real-time.

Morphological study of the particle-to-fiber transition threshold during electrohydrodynamic processing of chitosan solution

In this work, solutions of low molecular weight chitosan with the concentration of 4 and 5 wt.% were subjected to electrohydrodynamic forming at the feed rate of 0.1 and 0.2 ml/h. Using a statistical analysis of the electron scanning microscopy data, it was shown that at the concentration of 4 wt.%, spherical particles of two types are formed: most of the particles are with the average diameter about of 260 nm, and particles with a larger diameter of about 480 nm. A transition through the particle-to-fiber threshold was observed with an increase in the concentration of the solution to 5 wt.%. This led to the formation of both spherical particles with a monomodal distribution and average diameter of 207 nm and elongated particles of a fiber-like shape with diameter of 157 nm and length of 1401 nm. At the same time, an increase in the solution feed rate resulted in a strong decrease in the average diameter of spherical particles to 150 nm and an elongation of fiber-like objects by 1.5 times. The particle-to-fiber threshold can be observed when the dynamic viscosity of the solution changes in the range of about 10–14 cP.

Design, Simulation and Experimentation of an Axial Flow Sunflower-Threshing Machine with an Attached Screw Conveyor

Sunflower threshing is one of the most interesting field processes for making the sunflower ready for seed handling, drying, cleaning and oil extraction. One of the biggest problems observed during the sunflower threshing process is the accumulation of threshed crop on the first third of the threshing roller and passing off some unthreshed parts of sunflower heads. To solve the aforementioned problem and optimize the efficiency of the sunflower threshing process, this research was focused on devising and testing a sunflower threshing machine with a close threshing box system equipped with a screw conveyor that evenly distributed the feedstock of sunflower heads on the entire length of the threshing roller. The machine was tested to assess the seed damage rate, unthreshed seed percentage, threshing efficiency, machine productivity, power requirements and specific energy consumption. The evaluation was done under different roller rotational speeds (150, 200, 250 and 300 rpm) and feeding rates (600, 700, 800 and 900 kg/h). The obtained results revealed that the threshing evaluation parameters were affected significantly by the roller rotational speed and feeding rate. The threshing efficiency was observed to rise with the rise in the roller rotational speed, and it also rose with the increasing feed rate up to 800 kg/h and then started to descend. The unthreshed seed percentage decreased with the increase in the roller rotational speed for all feed rates, and it decreased with the increasing feed rate up to 800 kg/h and then started to increase at the higher feed rates. The damaged seed percentage, power requirement and machine productivity increased with the increase of the roller speed and feed rate. The Buckingham π theorem was followed to find an equation to predict the threshing efficiency, resulting in an equation with an R2 value of 0.9309. With elimination of the blockage problem and better threshing efficiency, this machine could be a good choice for small- to medium-sized sunflower farms.

Fixed-bed column dynamics of ultrasound and Na-functionalized diatomite to remove phosphate from water.

A continuous fixed-bed column study was used to evaluate phosphate adsorption performance of U-D-Na which was functionalized by the cheap NaCl reagent after simple ultrasonic purification of diatomite. In this work, various effect factors, including flow rate, initial phosphate concentration, and the bed height, on breakthrough performance of fixed column were investigated. Experimental results demonstrated that the breakthrough time declined with the increase of inlet phosphate concentration and feed rate, whereas the increase of bed height turned out to significantly extend the breakthrough time. The dynamic adsorption process could be well fitted by the Thomas model, with a correlation coefficient R2 > 0.9000 under main operating conditions. A thrice loop of effective regeneration was achieved with 0.1 M hydrochloric acid eluent and deionized water. The maximum removal rate for phosphate was more than 95% in the column adsorption process. The results proved that U-D-Na could be used as a better alternative phosphate adsorbent for wastewater in a continuous column sorption process.

Research on Dilution of Laser Cladding Assisted by Pulsed Current Based on Orthogonal Experiment

With characteristics of high cladding efficiency, small grain size and low porosity, follow-up feeding pulse current assisted laser cladding can realize online self-healing of cracks on the cladding layer and get a crack-free cladding layer. It is a very promising new laser cladding technology. In this study, effects of cladding parameters (laser power, scanning speed, powder feed rate, pulse current, pulse frequency and pulse width) on dilution rate of coating were discussed through a six-factor three-level orthogonal experimental design method. Results demonstrated that laser power, scanning speed and powder feed rate can influence dilution ratio greatly, while pulse current, pulse frequency and pulse width influence the dilution ratio slightly. Among the top three major factors, laser power can influence the dilution ratio mostly, followed by powder feed rate and scanning speed. The dilution ratio increases with the increase of laser power, scanning speed and pulse width, but it decreases with the increase of powder feed rate and pulse frequency. With the increase of pulse current, the dilution ratio decreases firstly and then increases.

Thermal sensitivity of juvenile rabbitfishes Siganus doliatus and S. lineatus (Siganidae): a key role for habitat?

The majority of our understanding of the effects of climate change on coral reef fishes are currently based on studies of small-bodied species such as damselfishes. By contrast, we know little about the potential impacts of ocean warming on larger species of herbivorous and detritivorous reef fish, despite them being a critical functional group and an essential source of food protein for millions of people. In addition, we know little of the role of habitat in determining species’ thermal sensitivity and the legitimacy of extrapolating thermal performance across closely-related species from different habitat types. Here we test the effect of exposure to increased water temperature during juvenile development on key physiological and behavioral traits of two species of rabbitfish typically associated with different habitats: Siganus doliatus (reef-associated) and S. lineatus (estuarine). Wild-caught juveniles were reared for 14 weeks at temperatures representing present-day ambient conditions (28.0 °C), late-summer ambient conditions (30.0 °C), or those projected on reefs under future global warming scenarios (31.5 °C). We then measured the somatic (growth, condition, immune response) and behavioral (feeding rate, latency to feed and activity level) traits of individuals within each treatment to determine the sensitivity of each species to elevated water temperatures. Overall, both species showed comparatively robust levels of thermal tolerance, based on previously-documented responses of small-bodied reef fishes. However, two very different patterns emerged. The reef-associated S. doliatus showed a greater physiological response to temperature, with negative effects on hepatosomatic condition and immune function observed in individuals exposed to the 31.5 °C treatment. By contrast, there were no negative physiological effects of temperature observed in S. lineatus and instead we recorded behavioral changes, with individuals at 30 °C and 31.5 °C displaying altered feeding behavior (increased feeding rate and decreased latency to feed). These distinct responses observed between congeners are likely due to their evolutionary history and flag the potential inaccuracies that could arise from extrapolating effects of ocean warming across even closely-related species adapted to different habitats.

Feed management of Litopenaeus vannamei in a high density biofloc system

One area with significant potential for improvement in commercial shrimp production is feed management. Consequently, feed management is critical to optimize especially in intensive systems. Hence, the purpose of this study was to observe the response of Litopenaeus vannamei to different feed inputs in an intensive production system. The growth trial was conducted in an outdoor biofloc recirculating aquaculture system consisting of 24, 0.75m2 culture tanks stocked at a density of 160 shrimp/m2 (initial weight 0.17 g) and grown for 63 days. Treatments consisted of seven varying feeding rates (30%, 60%, 90%, 105%, 120%, 135%, and 150%) which was offered 4 times per day, and an eighth treatment that was fed 150% of the standard feeding rate using a belt feeder that fed six times daily. At the conclusion of the trial, significant differences in final weight and feed conversion ratio were observed. Regression analysis performed on the first three feeding rates (30%, 60% and 90%) determined that natural foods were responsible for approximately 280 g of total shrimp biomass, or 17% of maximum biomass gain. Results indicated that increasing feed rates over 100% of the standard rate led to an increase in final weight, albeit shrimp growth shows signs of approaching plateau, and FCR increases. Results demonstrate efficacy of culturing shrimp in high density biofloc systems across a range of feed inputs and achieving desirable growth (1.27–1.55 g/week), final weight (11.62–14.15), feed conversion ratios (1.04–1.19), and survival (94.17–96.94). Restrictive feeding produces the most efficient use of feed, albeit at a cost of total weight gain. As maximum gain is approached, there is an inflection point at 101% of the standard feeding rate where growth and feed utilization decline rapidly leading to increase in FCR and smaller gains in growth. Hence, a goal for maximum gain will be offset by increased FCR. Consequently, to maximize nutrient utilization it is recommended to feed below maximum gain.

Ultrasonic-assisted grinding experiments on quartz glass and investigation of factors influencing surface roughness

In order to study the grinding mechanism of quartz glass, a three-factor four-level orthogonal test under ultrasonic grinding and non-sonic grinding conditions was designed to investigate the laws of spindle speed, feed rate and depth of cut on the surface roughness of quartz glass. The extreme difference analysis and the analysis of influencing factors were carried out for ultrasonic grinding and non-ultrasonic grinding experiments. The experimental results show that the surface roughness of ultrasonic grinding quartz glass decreases with the increase of spindle speed, increases with the increase of feed speed and increases with the increase of depth of cut. The surface roughness of non-sonic grinding quartz glass increases with increasing spindle speed, increases with increasing feed rate, and decreases with increasing depth of cut. This study provides important implications for the study of the grinding mechanism of quartz glass.

Research on CFRP inner wall roughness during vibration drilling of CFRP/Ti based on acoustic emission

Aiming at the quality problem of the CFRP inner wall in the CFRP/Ti laminated material assisted vibration drilling technology, the acoustic emission (AE) signals of different processing parameters during drilling are collected. Analyze the relationship between the characteristics of the acoustic emission signals and the roughness of the CFRP inner wall under different processing parameters and different number of holes. The test results and analysis show that other parameters are kept unchanged during the test process, only one parameter is changed. When the amplitude and spindle speed increase, the AERMS value increases while the CFRP inner wall roughness decreases. When the feed rate increases, the AERMS value and CFRP inner wall roughness increase simultaneously. The energy ratio of the wavelet packet of the AE signals is also closely related to the roughness of the CFRP inner wall. Therefore, in the actual machining process, the CFRP inner wall roughness can be monitored by monitoring the AE signals to improve the processing efficiency.

Investigation of machinability properties of aluminium matrix hybrid composites

In this study, machinability properties of aluminium matrix boron carbide (B 4 C) and carbon nanofiber (CNF) reinforced hybrid composite material produced by powder metallurgy in drilling were investigated. In the study, the samples produced with hot pressing technique having 6 different volume rates were used. The drilling operations were performed using drills with 3 point angles (90°–118°–135°) at 30–45-67.5 m/min cutting speed and 0.1–0.15–0.225 mm/rev feed rate. As a result of the experiments, the thrust force, moment, and surface roughness were measured and the delamination factor forming at hole exits was calculated. In addition, the effect of reinforcement rate on the machinability was also investigated. In all drill types, it was determined that as the feed rate increased, the thrust force increased and as the reinforcement rate increased, moment values also increased. Surface roughness values increased with the increased feed rate but decreased as the cutting speed increased. As the drill point angle increased, the surface roughness value decreased but the hole exit damage increased. • Low volume rate carbon nanofiber reinforcement had a positive effect on machinability properties. • As the drill point angle increased, the surface roughness value decreased but the hole exit damage increased. • Surface roughness decreased with the increase in the amount of reinforcement. • The two most effective parameters in hole exit damage are the point angle and feed rate.