Key Laboratory of Agricultural Engineering in Structure and Environment

Beijing, China

Key Laboratory of Agricultural Engineering in Structure and Environment

Beijing, China

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Zheng W.,China Agricultural University | Zheng W.,University of Illinois at Urbana - Champaign | Li Z.,China Agricultural University | Shah S.,University of Illinois at Urbana - Champaign | And 4 more authors.
Applied Engineering in Agriculture | Year: 2016

Air contaminants emitted from animal buildings may harm the environment and public health. A windbreak wall with slightly acidic electrolyzed water (SAEW) sprayed downwind of the exhaust fans offers a potential approach for the removal of some of these air contaminants, including ammonia and airborne culturable bacteria (CB). This study was conducted to investigate the removal efficiency of ammonia and airborne CB by a proof-of-concept windbreak wall with SAEW spray for a layer breeding house. A windbreak wall with spraying system was placed downwind of an exhaust fan. Tap water and SAEW, a novel environment-friendly disinfectant, were used in the spraying system. Separate sampling manifolds for ammonia and airborne CB were placed at the inlet and the outlet of the windbreak wall, respectively, for ammonia and CB sampling. The windbreak wall with water spray and 70 mg L-1 (available chlorine concentration) SAEW spray both significantly reduced ammonia emissions from the house though the removal was small. The 70 mg L-1 SAEW spray showed a numerically higher ammonia removal efficiency (13.2%) than water spray (8.8%), but no significant difference was found (p = 0.13). The windbreak wall with 70 mg L-1 and 100 mg L-1 SAEW spray both significantly and moderately reduced airborne CB emission from the layer breeding house (p < 0.01) but the two SAEW concentrations yielded similar removal efficiencies (~40%). Additional design improvements are needed to increase the removal efficiency of pollutants. An improved windbreak wall with SAEW spray could be a promising technique for reducing emissions from animal houses. © 2016 American Society of Agricultural and Biological Engineers.


Yu L.,Key Laboratory of Agricultural Engineering in Structure and Environment | Teng G.,Key Laboratory of Agricultural Engineering in Structure and Environment | Li B.,China Agricultural University | Zhang Y.,China Agricultural University | And 3 more authors.
Applied Engineering in Agriculture | Year: 2013

This article describes a remote-monitoring system for poultry production management. This system had three essential components: an on-site data acquisition program, 3G wireless networks, and remote communication software. All data were collected and transmitted via the wireless connection from a remote site. Environmental parameters including ambient temperature, relative humidity, light intensity and CO2 concentration of a compartment housing for a small-group (n=15) of laying hens were measured in a 24 h period with an interval of 10 min. Comparisons were made between the experimental group (data acquired by the system) and the control group (data recorded by the standard measuring instruments). During the collection of environmental parameters, the relative errors were less than 5%. Compared to the wired LANs, the average speeds of this 3G-based network reached 1267 kbps while the real-time communication and data transmission requires a minimum rate of 512 kbps for video, images, and text data. With over 95% accuracy for data acquisition and more than twice of the required speeds for data transmission, the remotemonitoring system based on 3G wireless networks could be an alternative tool for environmental management of poultry farms. © 2013 American Society of Agricultural and Biological Engineers ISSN 0883-8542.


Song W.,China Agricultural University | Song W.,Key Laboratory of Agricultural Engineering in Structure and Environment | Yao L.,China Agricultural University | Ding T.,China Agricultural University | And 3 more authors.
Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering | Year: 2011

The low energy efficiency of solar regenerator has been a common concern in the solar evaporation-dehumidification cooling system. In order to enhance the energy utilization efficiency, a gas-gas heat exchanger was used as an additional heat-recycle unit to capture residual heat from hot air. Two types of regenerators with(GGHEW) and without(GGHEN) gas-gas heat exchanger were studied and their performances were compared. The results showed that both dehumidification capability and efficiency of regenerator were enhanced with the increase of the temperature of water heated by solar energy. The basic performance of regenerator was significantly improved by adding gas-gas heat exchanger. Dehumidification capability of GGHEW was in a range from 40 to 55 g/kg, which was 35-45 g/kg more than that of GGHEN. The regeneration efficiency of GGHEW could reach up to 60% at 90°C of hot water, which was 30%-50% higher than that of GGHEN. It was concluded that installation of gas-gas heat exchanger on the solar regenerator can improve the solar energy utilization efficiency and the regeneration efficiency, which indicates that heat recycle is necessary for solar regenerator.


Gu Z.,Chongqing Academy of Animal Science | Gao Y.,Chongqing Academy of Animal Science | Lin B.,Chongqing Academy of Animal Science | Zhong Z.,Chongqing Academy of Animal Science | And 5 more authors.
Preventive Veterinary Medicine | Year: 2011

The limited space in farrowing crate imposes many challenges, such as prolonged farrowing duration and high piglet stillbirth rate. Although the features of farrowing pens compensate for the drawbacks of farrowing crates, they are associated with high piglet crushing mortality caused by the greater space afforded to sows and their rolling-over behaviour. Therefore, a freedom farrowing pen was designed to overcome the drawbacks of both farrowing crates and farrowing pens. The main features of the freedom farrowing pen are its left anti-crushing bar and detachable right anti-crushing bar on the sides of the sow lying area. It also has a 10. cm-high anti-crushing bar in the non-lying area. Eighteen healthy, multiparous Yorkshire sows (3-7 parity) were averaged and randomly assigned to farrowing crates, farrowing pens, and freedom farrowing pens to compare the effects of the farrowing systems on sow behaviour and performance. Results showed that the farrowing duration and the mean piglet birth intervals were longer for the sows in farrowing crates than for those in farrowing pens and freedom farrowing pens (P< 0.05), but there was no difference between the sows in farrowing pens and those in freedom farrowing pens (P> 0.05). The piglet stillbirth rate was higher for the sows in farrowing crates than for those in farrowing pens and freedom farrowing pens (P< 0.001). Crushing mortality was higher among piglets in farrowing pens (P< 0.001), but there was no difference between piglets in freedom farrowing pens and those in farrowing crates (P> 0.05). The freedom farrowing pen and the farrowing pen allowed sows to turn around and move freely, but because of the different structures of their anti-crushing bars, the increase in sow movement did not cause higher piglet crushing mortality (P> 0.05). Sows in freedom farrowing pens were found to be more protective of their piglets. © 2011 Elsevier B.V.


Ding T.,China Agricultural University | Ding T.,Key Laboratory of Agricultural Engineering in Structure and Environment | Huang Z.,China Agricultural University | Huang Z.,Key Laboratory of Agricultural Engineering in Structure and Environment | And 3 more authors.
Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering | Year: 2010

The technology of liquid desiccant and solar regeneration is the key technical problems of evaporative cooling in high temperature and humidity region, and the most important thing is the dehumidification/regeneration efficiency. The calculating relationship between the humidity content of in/out air and dehumidification efficiency was established through the experimental measurement. And the relationships of temperature of regeneration heat source to regeneration quality, diffusion coefficient and regeneration efficiency were researched. The results showed that with the regeneration temperature increasing, the regeneration quality, diffusion coefficient and regeneration efficiency were rising. When the regeneration temperature was 104°C, the regeneration quality was 10 g/kg, diffusion coefficient 0.277 cm2/s, and regeneration efficiency 55%. But when the regeneration temperature was lower 50°C, the regeneration cannot work. So the effective temperature regeneration was at least 70°C in solar energy mixed solution dehumidification system. Based on the Chung model, the calculation formula of dehumidification efficiency in the multistage cross flow dehumidifier was established for the solar energy dehumidification system, and the dehumidification efficiency was 56.8%. This research for greenhouse facilities dehumidifying technology provides a study basic.


Hassanien R.H.E.,China Agricultural University | Hassanien R.H.E.,Cairo University | Hou T.-Z.,China Agricultural University | Hou T.-Z.,Key Laboratory of Agricultural Engineering in Structure and Environment | And 2 more authors.
Journal of Integrative Agriculture | Year: 2014

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. © 2014 Chinese Academy of Agricultural Sciences.


Gu Z.,Key Laboratory of Agricultural Engineering in Structure and Environment | Gu Z.,China Agricultural University | Xin H.,Iowa State University | Wang C.,Key Laboratory of Agricultural Engineering in Structure and Environment | And 9 more authors.
Preventive Veterinary Medicine | Year: 2010

Modern commercial swine farrowing crates are typically equipped with slatted iron floor to improve management efficiency (e.g., ease of manure handling, cleanliness of the farrowing crates and hence improved animal hygiene). However, the bare and hard floor surface can impair the welfare of the sow-litter because of some undesirable impacts on the pigs, such as foreleg abrasion, large temperature gradients between the cold floor surface and the abdomen of the piglets (hence higher susceptibility to diarrhea), and higher pre-weaning mortality or morbidity. Although straw bedding has been shown to be conducive to providing better environment for the sow-litter, use of straw creates challenges in terms of economics, hygiene and manure handling. This study investigates the use of neoprene mat (NM) in key areas of the farrowing crates - underneath the sow and in the piglet suckling area to improve the microenvironment and hence welfare of the sow-litter. Two experiments were conducted, each involving 12 sow-litters. The first experiment was to evaluate the thickness of a rectangular-shaped NM (7, 10 or 13 mm) vs. the slatted iron floor (control or Ctrl) and collect the corresponding animal response data; while the second follow-up experiment was to verify the benefits of supplying an improved, double concave (or H)-shaped NM with 10 mm thick (CNM10) vs. Ctrl for the farrowing operation. Results of both experiments demonstrated considerable benefits of the NM placement in the farrowing crates. Specifically, the NM reduced the piglet foreleg lesion area and joint swellings (0% for NM vs. 8-10% for Ctrl during suckling periods in both Expts 1 and 2, P < 0.001); reduced pre-weaning piglet crushing mortality (18.5 ± 5.0%, 6.7 ± 3.3% and 9.1 ± 5.2% and for Ctrl, NM7 and NM10 and in Expt 1, P < 0.05); and reduced piglet diarrhea morbidity (0.6 ± 0.2% for CNM10 vs. 2.7 ± 0.3% for Ctrl in Expt 2, P < 0.01). Piglets in the NM litters had smaller temperature gradients between the abdomen and the contact floor surface (3.8 ± 2.3 °C for NM vs. 7.6 ± 0.5 °C for Ctrl in Expt 1, P < 0.001; 9.2 ± 0.5 °C for CNM10 vs. 15.9 ± 0.5 °C for Ctrl in Expt 2, P < 0.001). Moreover, sows in the NM regimens showed longer transition time when changing from standing to lying position (7.4 ± 0.3 s for CNM10 vs. 4.5 ± 0.2 s for Ctrl in Expt 2, P < 0.05), indicative of more floor comfort for the NM condition. Results of this study suggest that supply of NM underneath the sow and in the piglet suckling area is conducive to enhancing comfort, health and welfare of the sow and litter. © 2010 Elsevier B.V.


He H.,China Agricultural University | Zheng L.,China Agricultural University | Li Y.,China Agricultural University | Song W.,China Agricultural University | Song W.,Key Laboratory of Agricultural Engineering in Structure and Environment
Ozone: Science and Engineering | Year: 2015

This research combined micro/nano bubble techniques with ozone disinfection to determine feasibility of applying micro/nano bubble ozonated water in preventing tomato airborne disease. Results indicated that dissolving ozone in micro/nano bubbles is more efficient than using a mixing pump. In our in vitro studies, when dissolved ozone concentration was 1.6 mg/L, a 5.2 to 3.3 log reduction in Alternaria solani Sorauer conidia was observed; with concentration of 1.8 mg/L, there was a 5.0 to 3.7 log reduction in Cladosporium fulvum conidia. Furthermore, spraying ozonated water in a certain concentration range (0.6–1.8 mg/L) had no significant negative effects on tomato growth. © 2015 International Ozone Association.


Zheng W.,China Agricultural University | Zheng W.,Key Laboratory of Agricultural Engineering in Structure and Environment | Kang R.,Sichuan University | Wang H.,Sichuan University | And 4 more authors.
Journal of the Air and Waste Management Association | Year: 2013

Spraying slightly acidic electrolyzed water (SAEW) has been considered as a potential approach to reduce airborne bacteria in laying-hen houses. In this study, the effects of spraying SAEW on airborne bacterial reduction were investigated in a laying-hen house as compared with using diluted didecyl dimethyl ammonium bromide (DDAB). Averaged air temperature reduced by approximate 1 °C and average relative humidity increased by 3% at a stable ventilation rate (about 2.5 m3 hr-1 per bird) in the laying-hen house 30 min after spraying (120 mL m-2). Compared with the control without spraying, the airborne bacterial concentration was reduced by about 0.70 and 0.37 log10 colony-forming units (CFU) m-3 in the 4 hr after spraying 120 mL m-2 SAEW (available chlorine concentration [ACC] of 156 mg L-1) and diluted DDAB (active compound concentration of 167 mg L-1), respectively. Compared with spraying diluted DDAB, spraying SAEW was determined to be more effective for reducing airborne bacterial in laying-hen houses. The effects of spraying SAEW and diluted DDAB on airborne bacterial reduction in the laying-hen house increased with the increasing available chlorine concentrations for SAEW (156, 206, 262 mg L-1) and increasing active compound concentrations for diluted DDAB (167, 333, 500 mg L-1), respectively. Spraying SAEW and diluted DDAB with two levels of spraying volumes (120 and 90 mL m-2) both showed significant differences on airborne bacterial reduction in the laying-hen house (P < 0.05). It is difficult to effectively reduce airborne bacteria in laying-hen houses. This work describes the application of spraying slightly acidic electrolyzed water as a new approach for reducing airborne bacteria in a laying-hen house. The effects of active compound concentrations and spray volumes on the airborne bacterial reductions by spraying SAEW were also investigated. This study provided a new effective and environmentally friendly approach to reduce the airborne bacteria in poultry houses, contributing to bird housing environment management and improving bird health. © 2013 Copyright 2013 A&WMA.


PubMed | Key Laboratory of Agricultural Engineering in Structure and Environment
Type: Journal Article | Journal: Preventive veterinary medicine | Year: 2010

Modern commercial swine farrowing crates are typically equipped with slatted iron floor to improve management efficiency (e.g., ease of manure handling, cleanliness of the farrowing crates and hence improved animal hygiene). However, the bare and hard floor surface can impair the welfare of the sow-litter because of some undesirable impacts on the pigs, such as foreleg abrasion, large temperature gradients between the cold floor surface and the abdomen of the piglets (hence higher susceptibility to diarrhea), and higher pre-weaning mortality or morbidity. Although straw bedding has been shown to be conducive to providing better environment for the sow-litter, use of straw creates challenges in terms of economics, hygiene and manure handling. This study investigates the use of neoprene mat (NM) in key areas of the farrowing crates - underneath the sow and in the piglet suckling area to improve the microenvironment and hence welfare of the sow-litter. Two experiments were conducted, each involving 12 sow-litters. The first experiment was to evaluate the thickness of a rectangular-shaped NM (7, 10 or 13 mm) vs. the slatted iron floor (control or Ctrl) and collect the corresponding animal response data; while the second follow-up experiment was to verify the benefits of supplying an improved, double concave (or H)-shaped NM with 10mm thick (CNM10) vs. Ctrl for the farrowing operation. Results of both experiments demonstrated considerable benefits of the NM placement in the farrowing crates. Specifically, the NM reduced the piglet foreleg lesion area and joint swellings (0% for NM vs. 8-10% for Ctrl during suckling periods in both Expts 1 and 2, P<0.001); reduced pre-weaning piglet crushing mortality (18.5+/-5.0%, 6.7+/-3.3% and 9.1+/-5.2% and for Ctrl, NM7 and NM10 and in Expt 1, P<0.05); and reduced piglet diarrhea morbidity (0.6+/-0.2% for CNM10 vs. 2.7+/-0.3% for Ctrl in Expt 2, P<0.01). Piglets in the NM litters had smaller temperature gradients between the abdomen and the contact floor surface (3.8+/-2.3 degrees C for NM vs. 7.6+/-0.5 degrees C for Ctrl in Expt 1, P<0.001; 9.2+/-0.5 degrees C for CNM10 vs. 15.9+/-0.5 degrees C for Ctrl in Expt 2, P<0.001). Moreover, sows in the NM regimens showed longer transition time when changing from standing to lying position (7.4+/-0.3s for CNM10 vs. 4.5+/-0.2s for Ctrl in Expt 2, P<0.05), indicative of more floor comfort for the NM condition. Results of this study suggest that supply of NM underneath the sow and in the piglet suckling area is conducive to enhancing comfort, health and welfare of the sow and litter.

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