Pharyngeal Pumping Assay v1

The pharynx is a is a neuromuscular pump found at the anterior end of the alimentary tract, consisting of 20 muscles and 20 neurons. A proper feeding rate in worms is coordinated by the precise timing of pharyngeal movements, with one complete cycle of synchronous contraction and relaxation of the corpus and terminal bulb termed a “pump”. A simple way to measure C. elegans feeding is to count how many times worms pump in a minute (pumps per minute). Movement of the grinder (in the terminal bulb) can easily be observed using a stereomicroscope, and because cycles of contraction/relaxation are synchronised along the pharynx, pumps per minute can be measured simply by counting grinder movements.

Acute and chronic toxicity of mixtures of bisphenol A and trace metals (Cd and Pb) to micro-crustacean, Daphnia magna

The occurrence of plastic additives and their ecological impacts have attracted much attention in recent years globally. Among plastic additives, the trace metals (e.g., Cd, Pb) are widely used as color pigments and stabilizers, whereas bisphenol A (BPA) is added to enhance the desired physical characteristics of plastic products. However, these additives can easily leach out of plastic materials and enter the aquatic environment causing risks to aquatic ecosystems. Although the toxicity of a single additive on various aquatic organisms has been studied, the responses of zooplankton exposed to the mixed plastic additives have not been fully understood. Therefore, this study aims to evaluate the effects of the binary mixtures (BPA+Cd, BPA+Pb) and trinary mixture (BPA+Pb+Cd) at the metal concentrations of 5 µg/L and BPA level of 50 µg/ L on the life history traits and food feeding rate of the freshwater micro-crustacean, Daphnia magna. The results showed exposures to these mixtures for 24h could significantly enhance the food feeding rate of D. magna from 2.5 – 5.8 times higher than the control. The survival rate was decreased from 50 – 90% in the organisms exposed to these mixtures after 18 incubated days. We found a synergistic effect of BPA+Pb but an antagonistic effect of BPA+Pb+Cd on the survivorship of D. magna. Similarly, the organisms in the exposures delayed their maturity age and reduced their reproduction. The potent impact order of the mixtures on D. magna was BPA+Cd > BPA+Pb+Cd > BPA+Pb. Our results evidenced the adverse effects of plastic additive mixtures on aquatic organisms. Therefore, the use and disposal of plastic materials and plastic additives should be paid more attention to protect the environment, ecosystem, and human health. Moreover, our findings proved that the toxicity of multi-contaminants on organisms could be unpredictable even the toxicity of a single contaminant is known.

DESIGN AND EXPERIMENTAL STUDY OF FLEXIBLE THRESHING UNIT FOR CHINESE CABBAGE SEEDS

In order to solve the problems of low efficiency of artificial harvesting method and high breakage rate and undepurated rate of traditional threshing method, a new flexible threshing device of Chinese cabbage seeds was designed, which was composed of flexible round head nail teeth and circular tube concave plate. Hertz contact collision theory was used to analyze and determine the structural parameters of the new threshing unit. The interaction force of different threshing elements materials were analyzed by using EDEM. The feasibility of the flexible threshing unit was verified by the comparison test of the distribution of threshed mixture. Finally, the orthogonal test was carried out to study the influence of the movement parameters of each structure on the cleaning rate and the rate of undepurated, and the weight matrix method was used to optimize it. The results indicate that under the condition the rotating speed of the threshing cylinder 750 rpm, the concave clearance 20 mm, and the feeding rate 1.4 kg/s, the threshing performance of the flexible threshing unit was the best. At this time, the breaking rate was 0.064%, and the un-threshing rate was 0.67%, which both met the relevant industry standards.

Anaerobic Treatment for Palm Oil Mill Effluent Using Covered In-the Ground Anaerobic Reactor (CIGAR)

Wastewater from crude palm oil mills contains high organic matter, which potentially produces biogas through anaerobic digestion processes. The design and operation of an anaerobic bioreactor require a good understanding of the reaction kinetic in the bioreactor. This study aimed to evaluate the biogas production from POME and to determine the kinetic parameters of microbial growth and the substrate utilization rates in a CIGAR. An experiment was conducted using a 5-m3 bioreactor with a working volume of 4.4 m3. Wastewater from the Bekri palm oil mill was stored in a 5-m3 tank. After stabilization, the wastewater was loaded into the reactor at a rate of 100 to 250 L/d, corresponding to a COD loading rate of 1.373-3.097 kg·m-3.d-1, and an HRT of 18-44 days. Monod, Contois, Moser, and Shuler kinetic models were evaluated. The results showed that the Shuler model performed best for microbial activities, while the first order reaction model performed best for the substrate utilization kinetic. The maximum specific growth rate (μmax) for the Shuler model was 0.052 d-1 and the saturation constant (Kso) was 0.119. The maximum substrate utilization rate constant (ks) was 2.183 d-1 and biomass yield (Yx/s) 0.024 kg/kg. The maximum average efficiency of anaerobic degradation (34.4%) occurred at a feeding rate of 100 L/d with methane yield of 0.120 Nm3/kg of removed COD. This value is relatively low compared to the maximum potential of 0.350 Nm3/kg CODr.

Growth onset of perylene-based nanocrystals

The wide application of organic nanocrystals requires a deeper understanding of their nucleation mechanisms. In particular, the onset of nucleation still needs to be elucidated, although tremendous efforts have already been made in both experimental and simulation studies. In this research, we conduct molecular dynamics (MD) simulations, supported by quantum mechanical (DFT) calculations, to understand the mechanisms of the nucleation onset of organic perylene nanocrystals. Our DFT calculations indicate that face-to-face and face-to-edge molecular stacking can ultimately lead to the formation of a herringbone-style perylene nanocrystal. On the other hand, the results of MD simulations show the formation of clusters, which continues with the crystal nucleation in the form of unidirectional or multidirectional growth, depending on the feeding rate of perylene molecule in vacuum. This research helps to better understand the control of the growth of organic nanocrystals in modern nanotechnology.

Association of Feed Efficiency, Feeding Rate, and Behaviour with the Milk Performance of Dairy Cows

Identification of the associations of cow feed efficiency with feeding behaviour and milk production is important for supporting recommendations of strategies that optimise milk yield. The objective of this study was to identify associations between measures of feed efficiency, feed intake, feeding rate, rumination time, feeding time, and milk production using data collected from 26 dairy cows during a 3 month period in 2018. Cows averaged (mean ± standard deviation) 2.2 ± 1.7 lactations, 128 ± 40 days in milk, 27.5 ± 5.5 kg/day milk, 1.95 ± 0.69 kg feed/1 kg milk—the measure used to express feed conversion ratio (FCR), 575 ± 72 min/day rumination time, and 264 ± 67 min/day feeding time during the observation period. The coefficient of variation for rumination time (min/d) was 12.5%. A mixed linear model was selected for analyses. The most feed inefficient cows with the highest FCR (≥2.6 kg feed/1 kg milk) showed the lowest milk yield (24.8 kg/day), highest feed intake (78.8 kg), highest feeding rate (0.26 kg/min) and BCS (3.35 point). However, the relative milk yield (milk yield per 100 kg of body weight) was the highest (4.01 kg/day) in the most efficient group with the lowest FCR (≤1.4 kg feed/1 kg milk). Our study showed that the most efficient cows with the lowest FCR (≤1.4 kg feed/1 kg milk) had the highest rumination time (597 min/day; p < 0.05), feeding time (298 min/day; p < 0.05), rumination/activity ratio (4.39; p < 0.05) and rumination/feeding ratio (2.04; p < 0.05). Less active cows (activity time 164 min/day; p < 0.05) were the most efficient cows with the lowest FCR (≤1.4 kg feed/1 kg milk). The behavioural differences observed in this study provide new insight into the association of feed behaviour and feed efficiency with milk performance. Incorporating feeding behaviour into the dry matter intake model can improve its accuracy in the future and benefit breeding programmes.

Assessment of physiological and biochemical indicators of the state of the so-iuy mullet Liza haematocheilus (Temminck & Shlegel, 1845) in the Azov-Black Sea Basin

A comprehensive analysis of the physiological state of the so-iuy mullet, inhabiting the Sea of Azov, has been carried out during its pre-spawning period in 2020–2021. The hematological characteristics of the investigated individuals have been evaluated. It has been revealed that the content of protein and lipids in fish tissues was at the level of average longterm values. The content of protein and lipids in the gonads of females was significantly higher than that of males, which is explained by the forthcoming stage of spawning. It has been determined that the contribution of albumin to the total blood serum protein was minimal, which could be a consequence of the low feeding rate of the fish. At the same time, no stress effect was identified-glucose was within its normal range.

Dilution Optimization of Laser Cladding Assisted by Pulsed Current Based on Genetic Algorithm and Neural Network

The dilution ratio of the Ni coating prepared by the laser cladding under the assistance of the follow-up feeding pulsed current was optimized by combining back propagation (BP) neural network and genetic algorithm. The model was trained according to the results of the 6-factor 3-level orthogonal experiments. A BP genetic neural network forecast model between cladding parameters (laser power, scanning speed, powder feeding rate, pulsed current, pulse frequency and pulse width) and dilution ratio of coating was constructed. On this basis, technological parameters under the target dilution ratio of the coating were optimized by a genetic algorithm. Results demonstrated that the predicted results of the model are very close to the experimental results in term of dilution ratio of the coating, with a relative error no higher than 2.63%. This demonstrates that the model is reliable and effective. The optimal technological parameters are gained when the dilution ratio of the coating is 17.5%, including laser power=1926.3 W, laser scanning speed =·s-1, powder feeding rate= ·min-1, average pulsed current =, pulse frequency=445.6 Hz, pulse width= 108.4 μs.

Effect of Hammer Shape and Impact Area on Hammer Mill Performance under Different Feed Rates

The research aims to compare the performance (PC) and specific energy consumption (Spc.) of the hammer mill when using the T-hammer against the (traditional) rectangular hammer. A homemade mill with four hammers was used in experiment. 36 treatments: 2 hammer shape x 3 impact area (840, 720 and 960 mm2) x 2 feeding rates (1500 and 3000 g min-1) x 3 replicates, with completely random design. The results showed that there was no significant effect of hammer shape on PC at the feed rate of 3000 g min-1, while there was an effect at the rate of 1500 g min-1. An effect was also found for the impact area on the PC at both feeding rates and on Spc., as an inverse relationship appeared between the impact area and mill productivity at the feed rate 1500 g min-1. The area of 720 mm2 surpassed the area 480 and 960 mm2 at the rate of feeding 3000 g min-1, as it recorded 1215.65 g min-1 compared to 950.65 and 882.65 g min-1, respectively. There is effect of feeding rate on PC and Spc. The traditional hammer is recommended for simplicity of design, manufacture and performance at high feed rates compared to the T-shaped hammer.