•A novel sensor system was established combining MFC, gas flow meter and pH meter.•Variations of sensor signals were more valuable for diagnosis of anaerobic process.•MFC exhibited compatible signal variations with pH and gas flow meters.•Transient responses of sensor signals were observed subject to disturbances.Process diagnosis is essential to ensure anaerobic fermentation stable and efficient. Here, a novel sensor system combining microbial fuel cell (MFC), gas flow meter and pH meter was developed to evaluate its feasibility for probing the anaerobic process established on a model high-rate bioreactor. Repeated transient responses of electrical signal, proton concentration, and gas flow rate, were observed subject to external disturbances. The transient response lasted from <1 h to 6 h. In addition, MFC obtained compatible signal variations with other sensors, and biofilm MFC (MFCBiofilm) resulted in better agreements than control MFC (MFCControl). These results revealed that 1) the composite sensor system was capable to probe anaerobic process, suggesting a novel approach for process analysis and diagnosis of biogas or biohydrogen production; 2) the variations of sensor signals might provide more valuable information for process diagnosis than sensor signals themselves.

To inform the modelling ammonia of emissions from manure surfaces and provide basic knowledge of the characteristics of airflow at the emission surface, laboratory experiments were performed using a scale model of a growing/finishing pig house with water in the pit and a clean slatted floor with various opening areas: 100%, 33.3% and 16.7%. At 100% opening area the headspace formed an integral part of the room airspace and this configuration was used as the reference treatment. The pig house model had two sidewall inlets and exhaust in the middle of the ceiling. The effects of room ventilation rate, slatted floor opening and headspace height in slurry pit on air velocity, turbulence intensity (Ti) and airflow pattern at manure surface were investigated.The mean air velocity at manure surface increased as ventilation rate increased with a constant inlet opening. Increasing the opening ratio of the slatted floor increased the air exchange rate in the slurry pit, resulting in a higher air velocity above manure surface. For 33.3% and 16.7% floor slat openings, the mean air velocity at the manure surface decreased as headspace height increased and this resulted in an increased mean Ti above the manure surface for 50 mm and 82 mm headspace heights, respectively. However, no significant differences were found in the mean Ti between four ventilation rates for 26 mm headspace height. Tests using smoke visualisation showed that the supply air travelled longer distances parallel to the manure surface at lower headspace heights than at higher heights before returning to the room space. Ammonia emission results from previous experiments can be explained by using the results of measurements of air velocity and Ti.A statistical model was developed to calculate the mean air velocity as a function of ventilation rate, opening ratio of the slatted floor and headspace height in the slurry pit (coefficient of determination R2 = 0.97). The mean air velocity was more sensitive to the ventilation rate than to the slatted floor opening ratio and the headspace height in the pit. Moreover, the mean air velocity was much more sensitive to variations in the ventilation rate at higher ventilation rates than at lower ventilation rates. However, the mean air velocity was much more sensitive at lower floor slat opening ratios and headspace heights than at higher ones.

A concrete slatted floor system that consists of a narrow-gap slatted floor and beneath it a slope bottom for separation of faeces and urine in pig houses was investigated. In the experiments, four concrete slatted floors with one of two slat profiles and one of two gap widths, and a steel wire slatted floor were studied to estimate their manure separation performance under practical conditions. To evaluate urine collection efficiency, seven slope gradients and two surface roughnesses of the slope bottom were investigated under laboratory conditions.The lowest percentage of faeces drainage (0.36%) and good urine drainage performance were obtained by a concrete slatted floor with 5 mm-wide gaps and a trapezoidal profile without sharp edges, indicating that separation of faeces and urine can be achieved on the surface of this slatted floor. Using the wet surface area of the slope bottom as an indicator of urine collection efficiency and emission source, a statistical model was developed based on slope gradient, surface roughness, amount of water and water drop height. It was found that the wet surface area of the slope bottom decreased as the slope gradient increased, but increased with increasing surface roughness. The wet surface area was much more sensitive to the variations of slope gradient at lower compared with higher gradient ranges. However, contrary sensitivity responses were obtained for surface roughness.A slope gradient of 20° with a surface coated with fine cement performed best and is recommended for the slope bottom design in the concrete slatted floor system.

Evaporative pad cooling systems are efficient in decreasing the inside air temperature of animal houses located in those regions characterised by hot and dry summers, but their suitability for hot and humid climates is not yet clear. The climate in China varies greatly from the North to the South, thus, an evaluation of the suitability of the evaporative pad cooling system to different climatic regions could be helpful for the environmental design of animal houses throughout China. In this paper, the suitability of an evaporative pad cooling system in poultry houses to the summer climate was evaluated using a fuzzy mathematical method to analyse 20-year's weather data from nine representative cities with various climates in China. The results of the evaluation showed that the average air temperature inside poultry houses could be lowered below 28 °C by using the evaporative pad cooling system for over 65% of the days in one hot season for Beijing, Xi'an and Jinan, while the temperature of about 70% days could be controlled to below 30 °C for the remaining cities. This indicates that evaporative cooling pads can meet the cooling requirements of poultry houses in the regions selected and this provides a scientific basis for the extension and application of evaporative pad cooling systems in China.

This study presents experimental validation of the kinetic parameters for fast pyrolysis of corn stalk to predict their behaviours in a horizontal entrained-flow reactor (HER). All experiments were performed in the temperature range from 792 to 1031 K and at a constant feed rate of 0.3 kg h−1. The computational fluid dynamics (CFD) method was applied to simulate the time–temperature profile for the reactants in the HER. CFD modelling results are validated by experimental particle image velocimetry (PIV) measurements and are used in combination with previous kinetic data for the fast pyrolysis of corn stalk to predict behaviour in the HER. Gas-plus-vapour pyrolysis predictions are found to be in reasonable agreement with the values measured from pyrolysis experiments of corn stalk in HER. The kinetic parameters determined at a high heating rate are capable of predicting pyrolysis yield starting from experiments performed at a laboratory scale or in industrial-scale pilot plant facilities.

Sound waves technology has been applied to different plants. It has been found that sound waves were at different frequencies, sound pressure levels (SPLs), exposure periods, and distances from the source of sound influence plant growth. Experiments have been conducted in the open field and under greenhouse growing conditions with different levels of audible sound frequencies and sound pressure levels. Sound waves at 1 kHz and 100 dB for 1 h within a distance of 0.20 m could significantly promote the division and cell wall fluidity of callus cells and also significantly enhance the activity of protective enzymes and endogenous hormones. Sound waves stimulation could increase the plant plasma-membrane H+-ATPase activity, the contents of soluble sugar, soluble protein, and amylase activity of callus. Moreover, sound waves could increase the content of RNA and the level of transcription. Stress-induced genes could switch on under sound stimulation. Sound waves at 0.1–1 kHz and SPL of (70±5) dB for 3 h from plant acoustic frequency technology (PAFT) generator within a distance ranged from 30 to 60 m every other day significantly increased the yield of sweet pepper, cucumber and tomato by 30.05, 37.1 and 13.2%, respectively. Furthermore, the yield of lettuce, spinach, cotton, rice, and wheat were increased by 19.6, 22.7, 11.4, 5.7, and 17.0%, respectively. Sound waves may also strengthen plant immune systems. It has been proved that spider mite, aphids, gray mold, late blight and virus disease of tomatoes in the greenhouses decreased by 6.0, 8.0, 9.0, 11.0, and 8.0%, respectively, and the sheath blight of rice was reduced by 50%. This paper provides an overview of literature for the effects of sound waves on various growth parameters of plant at different growth stages.

The effectiveness of slightly acidic electrolyzed water (SAEW) in reducing Escherichia coli, Salmonella typhimurim, Staphylococcus aureus or bacterial mixtures on stainless steel surfaces was evaluated and compared its efficacy with composite phenol solution for reducing total aerobic bacteria in animal transport vehicles. Stainless steel surfaces were inoculated with these strains individually or in a mixture, and sprayed with SAEW, composite phenol, or alkaline electrolyzed water for 0.5, 1, 1.5 and 2 min. The bactericidal activity of SAEW increased with increasing available chlorine concentration and spraying duration. The SAEW solution of 50 mg l−1 of available chlorine concentration showed significantly higher effectiveness than composite phenol in reducing the pathogens on stainless steel surfaces (P < 0.05). Complete inactivation of pathogens on stainless steel surfaces were observed after treatment with alkaline electrolyzed water followed by SAEW at 50 mg l−1 of available chlorine concentration for 2 min or alkaline electrolyzed water treatment followed by SAEW treatment at 90 mg l−1 of available chlorine concentration for 0.5 min. The efficacy of SAEW in reducing total aerobic bacteria in animal transport vehicles was also determined. Vehicles in the disinfection booth were sprayed with the same SAEW, alkaline electrolyzed water and composite phenol solutions using the automatic disinfection system. Samples from vehicle surfaces were collected with sterile cotton swabs before and after each treatment. No significant differences in bactericidal efficiency were observed between SAEW and composite phenol for reducing total aerobic bacteria in the vehicles (P > 0.05). SAEW was also found to be more effective when used in conjunction with alkaline electrolyzed water. Results suggest that the bactericidal efficiency of SAEW was higher than or equivalent to that of composite phenol and SAEW may be used as effective alternative for reducing microbial contamination of animal transport vehicles.