Search

The present study examined the long–term characteristics and relationship of atmospheric ammonia (NH3) with other trace gases (NO, NO2, SO2 and CO) at highly polluted urban agglomeration of Delhi, India. Measurements of ambient trace gases (NH3, NO, NO2, SO2, and CO) and meteorology were recorded at the observational site of Delhi from 2011–2022. Overall mean mixing ratios of ambient NH3, NO, NO2, SO2 and CO were 18.9 ± 5.0 ppb, 19.9 ± 4.8 ppb, 19.1 ± 5.3 ppb, 2.15 ± 0.38 ppb, and 1.47 ± 0.42 ppm, respectively during 2011—2022. During study, a significant diurnal and seasonal variation in mixing ratios of NH3, NO, NO2, and CO were observed except SO2 mixing ratio. During all the seasons, the mixing ratios of trace gases were observed higher during nighttime and lower during daytime. Correlation analysis reveals that the higher loading of NO, NO2 and CO influenced the mixing ratio of NH3 at the study site of Delhi. [ABSTRACT FROM AUTHOR]

The room temperature gas sensor has attracted sufficient attention due to the fact that low-power products are more suitable for practical environments. However, developing gas sensors with low detection limits remains challenging. In this paper, a room-temperature sensor was prepared by in situ growth of WO 3 nanospheres on SnO 2 inverse opal (IO) by aerosol assisted chemical vapor deposition (AACVD) method, detecting ppb level of ammonia. The WO 3 nanospheres are directly fabricated on IO, and their elemental composition, morphology and structure is characterized using XRD, SEM and TEM. The results show that WO 3 nanospheres have been prepared on SnO 2 IO successfully. It showes that the WO 3 /SnO 2 (WS) type sensor has a detection limit as low as 1 ppb at room temperature from the gas sensitivity data. In addition, the sensor's response value to 100 ppm NH 3 reached 65 %. Its excellent sensing performance depends on the distinctive morphology features of WO 3 and SnO 2. The hierarchical characteristic effectively enhances the sensing performance for NH 3. Consequently, this presents a feasible solution for fabricating the room temperature NH 3 sensor. [ABSTRACT FROM AUTHOR]

This study introduces an innovative approach for preparing gas sensors involving the formation of metal oxides from metal–organic framework materials via a two-step calcination process. A gas-sensitive material capable of detecting NH 3 at a concentration of 11 ppb at room temperature was developed using a simple and facile experimental method. Compared with materials produced in previous studies by one-step calcination, the C-doped ZnO developed in this study had a dispersed cubic porous morphology with a higher specific surface area and smaller pore size. During two-step calcination, urea acts as a structure-directing agent and increases the gas adsorption capacity of the final material. Additionally, the incorporation of urea slightly reduced the material's band gap. Further examinations confirmed the material's exceptional selectivity and long-term stability in detecting NH 3 , and response tests at 59 %, 75 %, and 85 % relative humidity indicated its tolerance to high-humidity environments. These outstanding characteristics suggest that the proposed fabrication method can produce metal-oxide materials with substantially enhanced gas-sensing performance. [Display omitted] [ABSTRACT FROM AUTHOR]

In this study, delay line surface acoustic wave devices were prepared using a 128° Y-cut LiNbO3 piezoelectric substrate. Pure MoS2 and composite materials of MoS2 and SiO2 with various morphologies were sprayed to form sensitive layers. By adjusting the amount of NH4OH catalyst in the precursors, the particle sizes of SiO2 nanospheres were successfully controlled at 70, 200, and 300 nm by the sol-gel method. SiO2 nanospheres were then added to the precursor for preparing rosette-shaped MoS2, and nanocomposites were synthesized by the hydrothermal method. As a result, two types of composite material were obtained, namely, the S-M structure and the M-S structure. As ammonia gas sensors, the results showed that all the sensors exhibited negative frequency shifts as the NH3 gas concentration increased. Surface area and pore size distribution analyzer (BET) analysis showed that the highest specific surface area of 115.57 m²/g occurred on the S-M structural composite material. The sensor using the S-M structural composite material has a sensitivity of 1932 Hz/ppm to NH3 gas. The sensing linearity R-squared value is approximately 0.99, with continuous dynamic sensing at NH3 gas concentrations of 5-50 ppm. Finally, we revealed that decorating MoS2 with SiO2 nanospheres can improve the adsorption of ammonia molecules and significantly enhance sensitivity. [ABSTRACT FROM AUTHOR]

Bi2S3/Ti3C2Tx nanomaterials were successfully prepared through a simple hydrothermal method. Various methods were used for their characterization, including XRD, XPS, SEM, EDS, and BET, along with testing their gas-sensing properties. The results showed that the response value to 100 ppm ammonia at room temperature reached 107%, which was 14.1 times higher than that of pure few-layer MXene. After undergoing anti-humidity interference testing, we observed that Bi2S3/Ti3C2Tx exhibited a higher response value in real-time monitoring of ammonia as humidity increased. Specifically, under 90% humidity conditions, its response value reached 1.32 times that of normal humidity conditions. This exceptional moisture resistance ensures that the sensor can maintain stability, and even exhibit superior performance, in harsh environments. Therefore, it possesses excellent selectivity, high-moisture-resistance, and long-term stability, making it significant in the field of medical and health monitoring. [ABSTRACT FROM AUTHOR]

With the deep integration of industries such as the Internet of Things (Iot), big data, and artificial intelligence, sensors are becoming more and more interconnected and intelligent, which also poses a higher challenge to the development of gas sensors with excellent gas sensitive performance. WO 3 -based gas sensors are widely used in the detection of H 2 S and NH 3 gases because of their unique electrical characteristics. This paper reviews the progress of WO 3 -based chemoresistive gas sensors for the difficult-to-remove reducing gases H 2 S and NH 3. First, the sensing mechanism of pure-phase WO 3 as well as the enhancement of WO 3 sensing through modification strategies, including the construction of heterojunctions, the electronic and chemical sensitization mechanisms of noble metal modifications, the protonation/deprotonation process of polyaniline (PANI), and photoexcitation, are discussed. In addition, the application of WO 3 gas sensors using different nanostructures (such as quantum dots, nanoparticles, nanowires, nanotubes, nanofibers, and flowers) for the detection of H 2 S and NH 3 gases is summarized in detail. Although pure-phase WO 3 can effectively detect toxic and hazardous gases, it still has the disadvantages of low sensitivity, poor selectivity and high operating temperature. Metal oxide semiconductor (MOS) compounding, ion doping, noble metal modification, organic conductive polymer compounding, carbon-based material loading, transition metal-disulfide compounds (TMDCs) modification, and light can effectively improve the gas-sensitive properties. Finally, the challenges and prospects of WO 3 -based H 2 S and NH 3 gas sensors are also thoroughly analyzed and discussed. [Display omitted] [ABSTRACT FROM AUTHOR]

Greenhouse gas and NH3 emissions are exacerbated by the inappropriate timing and excessive application of nitrogen (N) fertilizers in wheat cultivation in China. In this study, the impacts on N2O, CO2, and NH3 emissions of a delayed and reduced N application regime on the Huang-Huai-Hai Plain were investigated. The treatments comprised the control (N0), conventional N at 270 kg N ha−1 (N270) and optimized N application of 180 kg N ha−1 (N180), N180 + biochar at 7.5 t ha−1 (N180B7.5), N180 + biochar at 15 t ha−1 (N180B15), N180 + DMPP (a nitrification inhibitor; N180D), N180D + biochar at 7.5 t ha−1 (N180DB7.5), and N180D + biochar at 15 t ha−1 (N180DB15). Reduced N application (N180) lowered N2O and NH3 emissions. Biochar application resulted in a 4–25% and 12–16% increase in N2O and NH3 emissions, respectively. Application of DMPP significantly decreased N2O emissions by 32% while concurrently inducing a 9% increase in NH3 emissions. Co-application of DMPP and biochar significantly reduced the activity of nitrification enzymes (HAD, NOO), resulting in a reduction of 37–38% in N2O emissions and 13–14% in NH3 emissions. No significant differences in CO2 emissions were observed among the various N treatments except the N0 treatment. Application of DMPP alone did not significantly affect grain yield. However, biochar, in combination with DMPP, effectively increases grain yield. The findings suggest that the N180DB15 treatment has the potential to reduce emissions of N2O and NH3 while concurrently enhancing soil fertility (pH, SOC) and wheat yield. [ABSTRACT FROM AUTHOR]

Bi2S3/Ti3C2Tx nanomaterials were successfully prepared through a simple hydrothermal method. Various methods were used for their characterization, including XRD, XPS, SEM, EDS, and BET, along with testing their gas-sensing properties. The results showed that the response value to 100 ppm ammonia at room temperature reached 107%, which was 14.1 times higher than that of pure few-layer MXene. After undergoing anti-humidity interference testing, we observed that Bi2S3/Ti3C2Tx exhibited a higher response value in real-time monitoring of ammonia as humidity increased. Specifically, under 90% humidity conditions, its response value reached 1.32 times that of normal humidity conditions. This exceptional moisture resistance ensures that the sensor can maintain stability, and even exhibit superior performance, in harsh environments. Therefore, it possesses excellent selectivity, high-moisture-resistance, and long-term stability, making it significant in the field of medical and health monitoring. [ABSTRACT FROM AUTHOR]

Ammonia (NH3) has received considerable attention as a major reduced nitrogen. However, accurate estimates of the deposition amount are difficult due to its complex behavior characterized by bidirectional exchange between the atmosphere and the surface. We observed the vertical profile of NH3 concentration in a deciduous forest in Japan for 1 year to further advance the studies on NH3 bidirectional exchange in Asia, especially focusing on the process near the forest floor. The observation period lasted from September 29, 2020, to September 28, 2021, including leafy and leafless periods. Using the denuder sampling technique, we measured NH3 concentration in the forest at three heights (above the forest canopy, 30 m, and near the forest floor, 2 m and 0.2 m). NH3 concentrations tended to be highest at the top of the canopy (30 m). Focusing on the concentration near the forest floor, the concentrations at 0.2 m were frequently higher than those at 2 m regardless of the leafy and leafless period, thus suggesting NH3 emissions from the forest floor. NH3 concentration near the forest floor showed strong positive correlations with air temperature during the leafy period. The NH3 emissions from the forest floor during the leafy period were possibly due to the decomposition of leaf litter with increased air temperature. The decrease in leaf area index might induced the increase in NH3 concentration and emission. NH3 emission during the leafless period was also possibly dependent on the state of the deposition surface, apart from air temperature, relative humidity, and leaf area index. [ABSTRACT FROM AUTHOR]

Abstract Ammonia (NH3) has received considerable attention as a major reduced nitrogen. However, accurate estimates of the deposition amount are difficult due to its complex behavior characterized by bidirectional exchange between the atmosphere and the surface. We observed the vertical profile of NH3 concentration in a deciduous forest in Japan for 1 year to further advance the studies on NH3 bidirectional exchange in Asia, especially focusing on the process near the forest floor. The observation period lasted from September 29, 2020, to September 28, 2021, including leafy and leafless periods. Using the denuder sampling technique, we measured NH3 concentration in the forest at three heights (above the forest canopy, 30 m, and near the forest floor, 2 m and 0.2 m). NH3 concentrations tended to be highest at the top of the canopy (30 m). Focusing on the concentration near the forest floor, the concentrations at 0.2 m were frequently higher than those at 2 m regardless of the leafy and leafless period, thus suggesting NH3 emissions from the forest floor. NH3 concentration near the forest floor showed strong positive correlations with air temperature during the leafy period. The NH3 emissions from the forest floor during the leafy period were possibly due to the decomposition of leaf litter with increased air temperature. The decrease in leaf area index might induced the increase in NH3 concentration and emission. NH3 emission during the leafless period was also possibly dependent on the state of the deposition surface, apart from air temperature, relative humidity, and leaf area index. Graphical Abstract

Abstract Urea is the most used fertilizer because of its significance on world food security but it is also the toughest fertilizer to manage. It is readily available to the plant and it is vulnerable to loss in various ways, causing environmental pollution and huge economic losses. Urea application requires a sound knowledge for its effective management, which will increase its availability to plants and reduce possible losses. Ammonia (NH3) and oxides of nitrogen (N) pollute the environment, and nitrate ( $${\text{NO}}_{3}^{ - }$$ NO 3 - ) leaching alters the aquatic ecosystem, which lowers the nitrogen use efficiency (NUE) of applied urea. Nitrate-contaminated drinking water causes human and animal health risks, whereas the emission of nitrous oxide (N2O) in the atmosphere is significant to ozone layer depletion and climate change. This review discusses the processes in the soil after urea application in the soil–plant system, which includes the loss mechanisms, and the significant factors affecting the N availability and losses. This review also shows that the judicial management of urea in soil–plant systems and maintaining the best management practices and technologies ensure sustainable agricultural development and decrease the risk of environmental contamination. Finally, the review summarizes the potential mechanisms of the applied urea in the soil with their mineralization and loss pathways and delivers the scientific reference to achieve sustainable crop production and reduce the risk of N losses. Graphical Abstract

Because of its current and future intensive use, the synthesis of sustainable ammonia is of major concern. This study focuses on highlighting the mechanistic behaviours of NH3 production from molecular nitrogen and hydrogen on ruthenium materials supported on cerium‐based ternary intermetallics. An interesting activity is reported for Ru/CeTX materials (T=Sc, Ti; X=Si, Ge) with an ammonia production rate around 0.60 mmolNH3 h−1 g−1 at only 300 °C and 1 bar. While the activity at 400 °C appeared attributable to the N≡N cleavage activation, this low‐temperature activity is no longer correlated with this parameter, but rather to the behaviour regarding hydrogen and especially the ability of cerium‐based intermetallic materials to desorb hydrogen from the structure, supporting an associative‐type mechanism. [ABSTRACT FROM AUTHOR]

In this work, zinc nanoparticles were prepared using the low-temperature plasma method at different times 3 min, 5 min, 7 min, 9 min, where the initial reactions of zinc lead to the formation of nanoparticles. The metal interacts with the ionized plasma under different conditions and may turn into an oxide such as exposing the sample to air and raising the temperature of the solution a few degrees as a result of high voltage and within a certain range. The atmospheric pressure plasma system acts as the cathode, while the zinc metal strip acts as the anode. A series of techniques were used, including the use of X-ray diffraction (XRD), ultraviolet-visible spectroscopy and scanning electron microscopy (FESEM). The X-ray diffraction results showed that the samples have polycrystalline structures with hexagonal and cubic structures with a time difference, and the X-ray diffraction results showed the conversion of zinc particles into zinc oxides. FESEM images reveal particle size and shape. The ZnO nanoparticles prepared by the mentioned method seem to form different nanoshapes such as starfish and mushroom nanoparticles. The UV-visible results showed that the samples had an energy gap of about 3.4 eV at a time of 3 min, and this value decreases with increasing reaction time. The appearance of zinc oxides increases gradually with the passage of time. These results provide credibility for the fabrication of ZnO nanostructures for use in future gas sensing applications, despite the inhomogeneity of particle size among ZnO particles, the sensor was also fabricated to detect nitrogen gas (NH3) with different concentrations (17.25 ppm, 46.38 ppm, 78.58 ppm). at room temperature. The ZnO sample showed the highest sensitivity (88.1%) at 7 min. The sensitivity showed different results and increased with reaction time and gas concentration. However, response and recovery time are moderate and decrease as reaction time increases. [ABSTRACT FROM AUTHOR]

An e‐nose is built on a single graphene field effect transistor (GFET), based on a graphene/Si3N4/p‐Si stack of layers. Multichannel data acquisition, enabling to mimic the architecture of a sensor array, is achieved by steering the gate potential, thus yielding a virtual array of 2D chemiresistors on a single sensing layer. This setting allows for the detection of volatile compounds with a remarkable discrimination capability, boosted by intensive machine learning analysis and accuracy maximization through the choice of the number of virtual sensors. Sensing of gas phase NH3 is tested, along with a set of possible interferents, and discrimination of NH3+NO2 mixtures is successfully probed. High throughput in terms of sensitivity is achieved by tracking the shift of the minimum of the GFET transfer curve versus NH3 concentration. With this readout scheme, a 20‐fold sensitivity increase over a 5–50 ppm range is registered to the same layer used as a chemiresistor. High discrimination capability is probed by leveraging machine learning algorithms, from principal component analysis (PCA) to Uniform Manifold Approximation and Projection (U‐MAP) and, finally, to a Deep Neural Networks (DNN) where input neurons are the virtual sensors created by the gate voltage driving. For the tested case, the DNN maximum accuracy is achieved with 21 virtual sensors. [ABSTRACT FROM AUTHOR]

Whether farmers should consider the role of arbuscular mycorrhizal fungi (AMF) in agriculture is a hotly debated topic. We aimed to investigate the role of indigenous AMF in reducing nitrogen (N) loss from paddy fields via runoff, leaching, NH3 volatilization, and N2O emission. We conducted a pot experiment employing a mycorrhiza‐defective rice mutant (non‐mycorrhizal) as the control, grown in soil containing indigenous AMF. The corresponding AMF treatment used the progenitor of this mutant with the same soil. The plants were fertilized with nitrogen, phosphorus and potassium 6 weeks after sowing. The root colonization was 23% in mycorrhizal rice, and no typical AMF structures were observed in the roots of non‐mycorrhizal rice. Our findings indicated that the mycorrhizal system exhibited lower N concentrations of runoff and leachate further compounded by reduced fluxes of N2O and NH3. This led to 14% decrease (mycorrhizal rice 111 kg N ha−1; the non‐mycorrhizal rice: 129 kg N ha−1) in cumulative N loss within 3 days post‐fertilization. While this AMF effect was consistent across the four tested N loss pathways, differences were observed between NH4+‐N and NO3−‐N in the runoff pathway. Notably, our results revealed no evidence of trade‐offs in AMF effect on N loss among the tested pathways. Additionally, mycorrhizal rice had larger shoots and roots than their non‐mycorrhizal counterparts. Our study underscores the potential benefits of indigenous AMF in paddy fields for mitigating water pollution and reducing greenhouse gas emission. [ABSTRACT FROM AUTHOR]

Assessing ammonia in water is very important for fish farmers as it is one of the pollutants that may affect the water quality. In water, ammonia can be found either in the form of unionised ammonia (NH3) or ionised ammonia (NH4 +), which contribute to a total ammonia nitrogen (TAN). In assessing the ammonia toxicity, NH3 provides a more accurate measure of toxicity and needs to be monitored consistently, rather than relying solely on TAN. However, the method of measuring NH3 in water can be complex and challenging. Therefore, the ability to determine the correlation between NH3 and other parameter which is easier to be measured (such as pH) is crucial to enable the estimation of NH3. This study was conducted to determine the correlation between NH3 and pH based on the data collected from Redgold Aquatics ornamental fishponds located in Sik, Kedah. The pH was assessed by a commercial measuring device, while the NH3 was calculated using an appropriate mathematical equation that requires the data of pH, TAN, and temperature. The correlation and regression analysis were conducted via t h e IBM SPSS tool and Microsoft Excel. The result shows that NH3 and pH are highly correlated with regression equation of NH3 = 0.01pH -- 0.07. In addition, factors that may affect the total ammonia value have been discussed thoroughly in this work. The analysis of these water quality parameters may assist farmers in estimating the toxic ammonia, NH3 from the known water pH. [ABSTRACT FROM AUTHOR]

A facile and prudent approach has been developed to deposit cobalt ferrite (CoFe2O4) films on the surface of the precursor solution by purging ammonia vapors over it. The vigorous technique to control the thickness of the film attributes spectacular characteristics to this approach. The study of CoFe2O4 films has been carried out by using FE-SEM, AFM, XRD, and UV-Visible spectroscopy. FE-SEM micrographs confirm the formation of the thin films composed of nanoparticles. The AFM micrographs indicate an increase in the root mean square roughness value with purged NH3 concentration due to the aggregation of nanoparticles. The observed XRD spectra show a cubic spinel structure of CoFe2O4 films with an increase in crystallite size in the range of 20–45 nm on increasing the NH3 concentration. UV – Visible spectroscopic investigations show a decrease in the band gap energy from 2.84 to 2.37 eV on account of the increased concentration of NH3 vapors. [ABSTRACT FROM AUTHOR]

Urea is the most used fertilizer because of its significance on world food security but it is also the toughest fertilizer to manage. It is readily available to the plant and it is vulnerable to loss in various ways, causing environmental pollution and huge economic losses. Urea application requires a sound knowledge for its effective management, which will increase its availability to plants and reduce possible losses. Ammonia (NH3) and oxides of nitrogen (N) pollute the environment, and nitrate ( NO 3 - ) leaching alters the aquatic ecosystem, which lowers the nitrogen use efficiency (NUE) of applied urea. Nitrate-contaminated drinking water causes human and animal health risks, whereas the emission of nitrous oxide (N2O) in the atmosphere is significant to ozone layer depletion and climate change. This review discusses the processes in the soil after urea application in the soil–plant system, which includes the loss mechanisms, and the significant factors affecting the N availability and losses. This review also shows that the judicial management of urea in soil–plant systems and maintaining the best management practices and technologies ensure sustainable agricultural development and decrease the risk of environmental contamination. Finally, the review summarizes the potential mechanisms of the applied urea in the soil with their mineralization and loss pathways and delivers the scientific reference to achieve sustainable crop production and reduce the risk of N losses. [ABSTRACT FROM AUTHOR]

Agonistic behavior is a problem of animal welfare in commercial turkey fattening. In this study, possible influences of the barn layout and the climate of the barn on the behavior of fattening turkeys on a commercial farm were investigated. The study was conducted on a turkey farm with two comparable barns. A modified ventilation system was installed in the trial barn to improve the removal of NH3 and CO2. The drinkers were rearranged to increase the animals' free floor area. In each barn, 3600 male turkeys (B.U.T. 6) were housed. Videos were recorded continuously from housing until removal for three consecutive fattening periods. NH3 and CO2 values were recorded. Turkeys showed increased activity (p < 0.001) and comfort behavior in the trial barn during late fattening (p = 0.002). Agonistic behavior increased during late fattening, particularly around the drinkers (p < 0.001). NH3 levels differed at the beginning of fattening. The study shows that extending the resting area contributes to increased activity and comfort behavior. The rearrangement of drinkers showed no positive effects on agonistic behavior, as the distance between individual drinkers was too small. Due to behavioral differences being most evident in late fattening, no conclusions can be drawn concerning the influence of CO2 and NH3. [ABSTRACT FROM AUTHOR]

Successfully made adsorbent of activated carbon made from purple corn cob which aims to minimize ammonia (NH3) levels found in water in fish farming with cage ponds. Activated carbon using carbonization method with a change in temperature that is between 550°C, 600°C, and 650°C and activation using Na2CO3 solution as activator. Activated carbon that has been obtained has exceeded the standard of SNI No.06-3730-1995, with characteristics including carbon yield ranging from 79.71% to 89.85%, moisture content ranging from 11.3% to 25.4%, volatile matter content ranging from 10.10% to 24.5%, ash content ranging from 9.7% to 9.9%, and fixed carbon content ranging from 65.7% to 79.7%. Then test results were obtained such as CO2 functional groups were found to enhance the adsorption process. Activated carbon displays the presence of a predominantly amorphous structure but also revealed a crystalline carbon structure. The highest peak was obtained at 29.7° with Miller index (201). The activated carbon displays the presence of pores on the scattered surface with carbon elements dominating. Adsorption mechanism to reduce ammonia (NH3) using activated carbon due to intermolecular interaction process. So that when testing the application for ammonia absorption, the best results were obtained in the sample with an adsorbent mass of 1.50 g at a carbonization temperature of 650°C with an adsorption capacity value of 546.34 mg/g and ammonia reduction of 82%. This research can open up opportunities for the potential development of new materials, especially for fish farming through cage techniques.

Molybdenum oxides and sulfides stand out as promising materials for chemiresistive gas sensors. In this study, we tailored MoS2/MoO2 heterostructures, adapting pyrolysis-assisted in situ sulfidation of hydrothermally grown MoO3 by tuning the concentration of the sulfur source. The MoS2 flakes adorning a MoO2 cuboid rod heterostructure represent the n-type semiconducting property, confirmed by Hall measurement. Notably, the sensor demonstrated dual selectivity toward NH3 and NOx at room temperature. To our knowledge, the dual selectivity of the MoS2/MoO2 heterostructure has not been reported previously. The heterostructure, characterized by a higher carrier concentration, displayed enhanced sensitivity, yielding responses of 10.3 and 8.4% to 10 ppm of NH3 and NOx, respectively. The lowest detection limits were 0.32 ppm for NH3 and 0.29 ppm for NOx. Furthermore, the heterostructure sensor exhibited commendable cyclic stability and device reproducibility. A long-term stability assessment over 50 days revealed that the response of the sensor remained at 98.6 and 98.4% toward NH3 and NOx, respectively. Our results show that the optimized n–n heterojunction between MoO2 and MoS2 offers superior sensitivity to NH3 and NOx at room temperature. The results could have potential for the development of dual gas sensors suitable for real-time applications. [ABSTRACT FROM AUTHOR]

Electrochemical nitrate reduction (NO3−RR) has been recognized as a promising strategy for sustainable ammonia (NH3) production due to its environmental friendliness and economical nature. However, the NO3−RR reaction involves an eight-electron coupled proton transfer process with many by-products and low Faraday efficiency. In this work, a molybdenum oxide (MoOx)-decorated titanium dioxide nanotube on Ti foil (Mo/TiO2) was prepared by means of an electrodeposition and calcination process. The structure of MoOx can be controlled by regulating the concentration of molybdate during the electrodeposition process, which can further influence the electron transfer from Ti to Mo atoms, and enhance the binding energy of intermediate species in NO3−RR. The optimized Mo/TiO2-M with more Mo(IV) sites exhibited a better activity for NO3−RR. The Mo/TiO2-M electrode delivered a NH3 yield of 5.18 mg h−1 cm−2 at −1.7 V vs. Ag/AgCl, and exhibited a Faraday efficiency of 88.05% at −1.4 V vs. Ag/AgCl. In addition, the cycling test demonstrated that the Mo/TiO2-M electrode possessed a good stability. This work not only provides an attractive electrode material, but also offers new insights into the rational design of catalysts for NO3−RR. [ABSTRACT FROM AUTHOR]

Processed manure products have the potential to substitute chemical fertilizers and the use of these products may increase resource efficiency in the food system and decrease emissions of ammonia (NH3) and greenhouse gasses (GHG). The yields of maize and grass, as well as emissions, have been determined from a processed manure product: liquid ammonium sulfate from nitrogen stripping animal manure (AS), in comparison to a regular mineral fertilizer, calcium ammonium nitrate (CAN), in a greenhouse experiment and a field demonstration using a sandy and a clay soil. NH3 emissions were determined by comparing AS with a dairy manure as a reference. The yield of both crops, their nitrogen nutrient use efficiency (NUE), and nitrous oxide (N2O) emissions were not significantly different, while NH3 emission was lower from AS compared to the dairy manure. As a side-effect, the sulfur (S) contents of the grass in the fields fertilized with AS were much higher than in the non-fertilized control. We conclude that AS, produced here with a pH < 5.5, can be used as an alternative for CAN in Dutch dairy systems, or similar other system, if S leaching losses do not pose a problem for the environment. Meanwhile, care should be taken not to exceed S in feed above toxic levels for ruminants. [ABSTRACT FROM AUTHOR]

The coupled combustion of coal with the carbon-free fuel NH 3 is an effective technology for reducing CO 2 emissions. Based on elemental analysis, proximate analysis, Fourier Transform infrared spectroscopy (FTIR), Carbon-13 Nuclear Magnetic Resonance (13C NMR), and X-ray photoelectron spectroscopy (XPS) characterizations, a coal macromolecular model was constructed. The combustion characteristics of coal/NH 3 co-firing were investigated by reactive force field molecular dynamics simulations (ReaxFF MD). The transformation mechanism of elemental N was elucidated. The influence of temperature, oxygen concentration, and NH 3 co-firing ratio (CR) on products was investigated. The results showed that during the non-isothermal combustion phase, the coal macromolecules decomposed more rapidly when the heating rate was low. In the isothermal phase, high temperatures promoted secondary reactions. The production of inorganic gases increased with increasing temperature. As the molar fraction of NH 3 increased, the production of CO 2 and CO was effectively reduced. There were three main pathways for NO formation. As NH 3 decomposed to form NH 2 , NH 2 was subsequently converted to NH, and NH reacted with O 2 to form NO. The NH 2 could also react with O radicals to form HNO, which was then converted to NO. Besides, both thermal NO x and prompt NO x were generated since the N 2 was involved in the reaction. In addition, the production of NO x increased significantly at oxygen concentrations greater than 1.4. [Display omitted] • The molecular model of coal was constructed based on experimental characterization. • Coal/NH 3 co-combustion characteristics were studied using ReaxFF MD. • The lower heating rates during heating contributed to decomposition of molecules. • High temperature promoted the secondary decomposition of tar in combustion systems. • The mechanisms for the conversion of nitrogen-containing products were revealed. [ABSTRACT FROM AUTHOR]

Herein, unloaded WO3 (WO3) and Pt‐loaded WO3 (Pt‐WO3) nanobars are successfully synthesized through simple hydrothermal and impregnation methods. X‐ray diffractometer analysis confirms the formation of a monoclinic WO3 structure. Surface analysis reveals that the Pt impregnation results in a significant increase in the specific surface area of WO3 nanobars. The gas‐sensing performance of sensors based on nanobars is measured toward ammonia (NH3) with varying NH3 concentrations at different operating temperatures. Compared with the pristine WO3 sensor, the Pt‐WO3‐based sensor with an optimal Pt content of 1 wt% exhibits a relatively low optimum operating temperature of 250 °C and a superior response of 960–50 ppm NH3. Furthermore, the Pt‐WO3‐based sensor also displays fast response, excellent NH3 selectivity to ammonia, moderate humidity dependence, and good stability. Therefore, the developed hydrothermal and impregnation methods could be a suitable alternative procedure for the synthesis of Pt‐WO3 nanobars useful for advanced NH3‐sensing applications. [ABSTRACT FROM AUTHOR]

This study employs density functional theory (DFT) calculations at the B3LYP/6-311+g(d,p) level to investigate the interaction of XH3 gases (X = N, P, As) with the Mn-phthalocyanine molecule (MnPc). Grimme's D3 dispersion correction is applied to consider long-range interactions. The adsorption behavior is explored under the influence of an external static electric field (EF) ranging from −0.514 to 0.514 V/Å. Chemical adsorption of XH3 molecules onto the MnPc molecule is confirmed. The adsorption results in a significant decrease in the energy gap (Eg) of MnPc, indicating the potential alteration of its optical properties. Quantum theory of atoms in molecules (QTAIM) analysis reveals partially covalent bonds between XH3 and MnPc, and the charge density differenc (Δρ) calculations suggest a charge donation-back donation mechanism. The UV-vis spectrum of MnPc experiences a blue shift upon XH3 adsorption, highlighting MnPc's potential as a naked-eye sensor for XH3 molecules. Thermodynamic calculations indicate exothermic interactions, with NH3/MnPc being the most stable complex. The stability of NH3/MnPc decreases with increasing temperature. The direction and magnitude of the applied electric field (EF) play a crucial role in determining the adsorption energy (Eads) for XH3/MnPc complexes. The Eg values decrease with an increasing negative EF, which suggests that the electrical conductivity (σ) and the electrical sensitivity (ΔEg) of the XH3/MnPc complexes are influenced by the magnitude and direction of the applied EF. Overall, this study provides valuable insights into the suggested promising prospects for the utilization of MnPc in sensing applications of XH3 gases. [ABSTRACT FROM AUTHOR]

Solar radiation triggers atmospheric nitrous acid (HONO) photolysis, producing OH radicals, thereby accelerating photochemical reactions, leading to severe secondary pollution formation. Missing daytime sources were detected in the extensive HONO budget studies carried out in the past. In the rural North China Plain, some studies attributed those to soil emissions and more recent studies to dew evaporation. To investigate the contributions of these two processes to HONO temporal variations and unknown production rates in rural areas, HONO and related field observations obtained at the Gucheng Agricultural and Ecological Meteorological Station during spring and autumn were thoroughly analyzed. Morning peaks in HONO frequently occurred simultaneously with those of ammonia (NH3) and water vapor both during spring and autumn, which were mostly caused by dew and guttation water evaporation. In spring, the unknown HONO production rate revealed pronounced afternoon peaks exceeding those in the morning. In autumn, however, the afternoon peak was barely detectable compared to the morning peak. The unknown afternoon HONO production rates were attributed to soil emissions due to their good relationship to soil temperatures, while NH3 soil emissions were not as distinctive as dew emissions. Overall, the relative daytime contribution of dew emissions was higher during autumn, while soil emissions dominated during spring. Nevertheless, dew emission remained the most dominant contributor to morning time HONO emissions in both seasons, thus being responsible for the initiation of daytime OH radical formation and activation of photochemical reactions, while soil emissions further maintained HONO and associated OH radial formation rates at a high level, especially during spring. Future studies need to thoroughly investigate the influencing factors of dew and soil emissions and establish their relationship to HONO emission rates, form reasonable parameterizations for regional and global models, and improve current underestimations in modeled atmospheric oxidation capacity. [ABSTRACT FROM AUTHOR]

The potential of Zn, Co and Mn doped Silicon, Carbon, Germanium, Aluminum Nitride (Si60, C60, Ge60, Al30N30) nanocages for N2-RR to produce the NH3 are examined by theoretical methods. The possible reaction steps of N2-RR on Zn, Co and Mn doped Silicon, Carbon, Germanium, Aluminum Nitride (Si60, C60, Ge60, Al30N30) nanocages are examined by theoretical methods. Results shown that the ∆Eadsorption of Silicon, Carbon, Germanium, Aluminum Nitride (Si60, C60, Ge60, Al30N30) nanocages are valuable. The Zn, Co and Mn doped Silicon, Germanium, Aluminum Nitride (Si60, Ge60, Al30N30) nanocages are done the N2-RR with lower potential than Zn, Co and Mn doped Carbon nanocages. The abilities of Zn, Co and Mn doped nanocages in this study for N2-RR are higher than C nanotube, BN nanotube and graphene derivatives in previous works. Finally, the Zn, Co and Mn doped Silicon, Carbon, Germanium, Aluminum Nitride (Si60, C60, Ge60, Al30N30) nanocages have high efficiency for N2-RR. [ABSTRACT FROM AUTHOR]

ABSTRACT: This work was designed to assess the impact of varying zeolite concentrations in diet and litter to enhance broiler's growth performance, immunity, and litter quality. A complete random arrangement was used for distributing 525 unsexed “Cobb 500” broiler chicks into seven treatments (75 chick / treatment), each treatment divided into 3 replicates (25 chicks / replicate). The 1st group (control one) received the recommended basal diet. Zeolite has been introduced to the basal diet (ZD) of the second, third, and fourth groups at concentrations of 5, 10, and 15 g/kg, respectively. The 5th, 6th and 7th groups used zeolite mixed with litter (ZL) at 0.5, 1, and 1.5 kg/m2 of litter, respectively. Due to the obtained results, adding zeolite with levels 15 g/kg of diet and 1.5 kg/1 m2 of litter, a significant improvement occurred in live body weight (LBW), body weight gain (BWG), feed intake (FI), feed conversion ratio (FCR) and European production efficiency factor (EPEF). Also, transaminase enzymes (ALT and AST), creatinine, white blood cells (WBCs) and different Immunoglobulins were significantly increased with different zeolite levels, except urea concentrations which showed reduced due to different zeolite treatments. In addition, spleen relative weight hasn't been affected by zeolite treatments, even though thymus and bursa relative weights had been affected significantly. Moreover, the antibodies' production to Newcastle disease virus (NDV) and Avian influenza virus (AIV) had increased significantly with adding zeolite with levels 10 g/kg of diet and 1.5 kg/1m2 of litter. Litter quality traits (NH3 concentration, pH values, and Moisture content) were improved with zeolite addition. So, zeolite could be employed in both feed and litter of broilers to maximize their production, immunity and improve farm's climate.

Greenhouse gas and NH3 emissions are exacerbated by the inappropriate timing and excessive application of nitrogen (N) fertilizers in wheat cultivation in China. In this study, the impacts on N2O, CO2, and NH3 emissions of a delayed and reduced N application regime on the Huang-Huai-Hai Plain were investigated. The treatments comprised the control (N0), conventional N at 270 kg N ha−1 (N270) and optimized N application of 180 kg N ha−1 (N180), N180 + biochar at 7.5 t ha−1 (N180B7.5), N180 + biochar at 15 t ha−1 (N180B15), N180 + DMPP (a nitrification inhibitor; N180D), N180D + biochar at 7.5 t ha−1 (N180DB7.5), and N180D + biochar at 15 t ha−1 (N180DB15). Reduced N application (N180) lowered N2O and NH3 emissions. Biochar application resulted in a 4–25% and 12–16% increase in N2O and NH3 emissions, respectively. Application of DMPP significantly decreased N2O emissions by 32% while concurrently inducing a 9% increase in NH3 emissions. Co-application of DMPP and biochar significantly reduced the activity of nitrification enzymes (HAD, NOO), resulting in a reduction of 37–38% in N2O emissions and 13–14% in NH3 emissions. No significant differences in CO2 emissions were observed among the various N treatments except the N0 treatment. Application of DMPP alone did not significantly affect grain yield. However, biochar, in combination with DMPP, effectively increases grain yield. The findings suggest that the N180DB15 treatment has the potential to reduce emissions of N2O and NH3 while concurrently enhancing soil fertility (pH, SOC) and wheat yield.

Ammonia (NH3) gas is prevalent in industrial production as a health hazardous gas. Consequently, it is essential to develop a straightforward, reliable, and stable NH3 sensor capable of operating at room temperature. This paper presents an innovative approach to modifying SnO2 colloidal quantum dots (CQDs) on the surface of Ti3C2Tx MXene to form a heterojunction, which introduces a significant number of adsorption sites and enhances the response of the sensor. Zero-dimensional (0D) SnO2 quantum dots and two-dimensional (2D) Ti3C2Tx MXene were prepared by solvothermal and in situ etching methods, respectively. The impact of the mass ratio between two materials on the performance was assessed. The sensor based on 12 wt% Ti3C2Tx MXene/SnO2 composites demonstrates excellent performance in terms of sensitivity and response/recovery speed. Upon exposure to 50 ppm NH3, the frequency shift in the sensor is −1140 Hz, which is 5.6 times larger than that of pure Ti3C2Tx MXene and 2.8 times higher than that of SnO2 CQDs. The response/recovery time of the sensor for 10 ppm NH3 was 36/54 s, respectively. The sensor exhibited a theoretical detection limit of 73 ppb and good repeatability. Furthermore, a stable sensing performance can be maintained after 30 days. The enhanced sensor performance can be attributed to the abundant active sites provided by the accumulation/depletion layer in the Ti3C2Tx/SnO2 heterojunction, which facilitates the adsorption of oxygen molecules. This work promotes the gas sensing application of MXenes and provides a way to improve gas sensing performance.

The present study investigates the functionalization of a commercial Metal-Organic Framework (MOF) named "MIL-53(Al)" using an NH 3 impulse dielectric barrier discharge (IDBD) plasma treatment. The main objective of this research is to assess the efficacy of the IDBD treatment in grafting nitrogenous groups onto the MOF's organic ligand. Additionally, the impact of the plasma functionalization on the hydrogen adsorption capacities of the "MIL-53(Al)" after IDBD treatment is also studied. In order to accomplish these objectives, plasma diagnostics and comprehensive material characterization techniques are utilized. Structural and thermal analysis by HT-XRD and TGA-MS respectively, indicate the excellent thermal and chemical stability of the material against high temperatures and ammonia. Chemical analysis of the materials by XPS shows that the IDBD treatment effectively functionalizes the MIL-53(Al) by substituting a carbon with a nitrogen within the organic ligand. Finally, the analysis of the hydrogen adsorption capacities at 1 bar and 25 °C reveals that the amount of hydrogen stored in the MIL-53(Al) treated by IDBD is significantly higher. Specifically, the amount of hydrogen stored surpassed the untreated MIL-53(Al) by approximately 50%. [Display omitted] • A post-synthetic modification process of MIL-53(Al) by IDBD plasma treatment is proposed and investigated. • NH radicals present in the plasma phase seem to contribute to graft amino groups onto MIL-53(Al) organic ligand. • Successful functionalization by IDBD treatment of MIL-53(Al) by substituting carbon with nitrogen within the organic ligand. • A 50% increase in hydrogen storage capacity for MIL-53(Al) treated by IDBD is obtained. [ABSTRACT FROM AUTHOR]

Rapid growth in the annual production of organic solid waste has become a huge challenge worldwide. Aerobic composting technology is one of the mainstream technologies based on utilizing organic solid waste resources. However, during the composting process, microorganisms are highly active, constantly decomposing organic matter and often produce large amounts of foul-smelling gases that are released in atmosphere, especially ammonia (NH3) and hydrogen sulfide (H2S) ; these gases have serious impacts on human and animal health as well as environmental quality. The present study focuses on summarizing the generation mechanism and transformation pathway of NH3 and H2S during the aerobic composting process of organic solid waste. Concerning the aspects of controlling endogenous parameters (C / N ratio, aeration rate, initial moisture content, and initial pH) and exogenous material addition (chemical, physical, and biological additives), this study introduces the synergistic emission reduction technologies of NH3 and H2S. Furthermore, this study proposes prospects for future research directions based on the research status quo in this field. A review of existing research has shown that various composting parameters interact with each other and must be considered and optimized together. The effect of regulating the endogenous parameters within the compost pile is limited. However, further optimization of the endogenous parameters and coupling of exogenous material addition can improve the emission reduction efficiency of NH3 and H2S during composting; this will help in promoting the green and efficient development of aerobic composting technology. [ABSTRACT FROM AUTHOR]

Context: The abilities of Co-Al18P18, Ni-Al21N21, Fe-B24N24, Mn-B27P27, Ti-C60 and Cu-Si72 as catalysts for N2-RR to create the NH3 are investigated by theoretical levels. The ∆Eadoption and ∆Eformation of Co-Al18P18, Ni-Al21N21, Fe-B24N24, Mn-B27P27, Ti-C60 and Cu-Si72 are investigated. The ∆Eadsorption of N2-RR intermediates and ΔGreaction of reaction steps of N2-RR on Co-Al18P18, Ni-Al21N21, Fe-B24N24, Mn-B27P27, Ti-C60 and Cu-Si72 are examined. In acceptable mechanisms, the *NN → *NNH step is potential limiting step and *NN → *NNH step in enzymatic mechanism is endothermic reaction. The ∆Greaction of *NHNH2 → *NH2NH2 step on Co-Al18P18, Ni-Al21N21, Fe-B24N24, Mn-B27P27, Ti-C60 and Cu-Si72 are -0.904, -0.928, -0.860, -0.882, -0.817 and -0.838 eV, respectively. The Co-Al18P18 and Ni-Al21N21 have the highest ∆Greaction values for reaction steps of N2-RR. Finally, it can be concluded that the Co-Al18P18, Ni-Al21N21, Fe-B24N24 and Mn-B27P2 have acceptable potential for N2-RR by acceptable pathways. Methods: The structures of Co-Al18P18, Ni-Al21N21, Fe-B24N24, Mn-B27P27, Ti-C60 and Cu-Si72 and N2-RR intermediates are optimized by PW91PW91/6-311+G (2d, 2p) and M06-2X/cc-pVQZ as theoretical levels in GAMESS software. The convergence for force set displacement of Co-Al18P18, Ni-Al21N21, Fe-B24N24, Mn-B27P27, Ti-C60 and Cu-Si72 and N2-RR intermediates are 1.5 × 105 Hartree/Bohr and 6.0 × 10-5 Angstrom. The Opt = Tight and MaxStep = 30 are considered to optimize Co-Al18P18, Ni-Al21N21, Fe-B24N24, Mn-B27P27, Ti-C60 and Cu-Si72 and N2-RR intermediates. The frequencies of Co-Al18P18, Ni-Al21N21, Fe-B24N24, Mn-B27P27, Ti-C60 and Cu-Si72 and N2-RR intermediates are calculated. [ABSTRACT FROM AUTHOR]

Autoclave devices are used to perform high‐temperature sterilization processes under pressure. Autoclaves can be integrated with an absorption refrigeration cycle to utilize the waste heat generated at high temperature during the process. Today, many studies are carried out on the evaluation of energy resources. In this study, it is designed to obtain a cooling load by adding an integrated sub‐cycle to the waste steam heat of the autoclave device in a sterilization unit. In the lower cycle, the ammonia/water absorption refrigeration cycle is used. According to the energy analysis; With the condition that the cooling temperature is 7°C, the generator temperature of 95°C and a cooling load of 130.9 W occurred with 531.7 W of waste heat received by the absorption cooling system. Accordingly, an efficiency of COP 0.246 was obtained. The energy analysis of the absorption refrigeration cycle can improve the energy efficiency of the autoclave and save energy. In addition, the obtained cooling load will be preserved in medical supplies that need to be kept cold. [ABSTRACT FROM AUTHOR]

• A new capture process of NH3-containing gas treatment with ionic liquids was designed. • MOGA method was employed to optimize the process operational parameters. • The comparison of water scrubbing and IL-based process was carried out. • TPC of enhanced process can be reduced by 32.41 % than water scrubbing. Ammonia (NH 3) emission has caused serious environment issues and aroused worldwide concern. The emerging ionic liquid (IL) provides a greener way to efficiently capture NH 3. This paper provides rigorous process simulation, optimization and assessment for a novel NH 3 deep purification process using IL. The process was designed and investigated by simulation and optimization using ionic liquid [C 4 im][NTF 2 ] as absorbent. Three objective functions, total purification cost (TPC), total process CO 2 emission (TPCOE) and thermal efficiency (η eff) were employed to optimize the absorption process. Process simulation and optimization results indicate that at same purification standard and recovery rate, the novel process can achieve lower cost and CO 2 emission compared to benchmark process. After process optimization, the optimal functions can achieve 0.02726 $/Nm3 (TPC), 311.27 kg CO 2 /hr (TPCOE), and 52.21% (η eff) for enhanced process. Moreover, compared with conventional process, novel process could decrease over $ 3 million of purification cost and 10000 tons of CO 2 emission during the life cycle. The results provide a novel strategy and guidance for deep purification of NH 3 capture. SYNOPSIS: This work guides to optimization of the process for NH 3 capture and NH 3 resource recovery based on ionic liquids. [Display omitted] [ABSTRACT FROM AUTHOR]

Copyright of Journal of Agro-Environment Science is the property of Journal of Agro-Environment Science Editorial Board and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Boron nitride (BN) is environment friendly chemical compound extracted from identical numbers of boron (B) and nitrogen (N) atoms. This research wants to evaluate the efficiency of BN nanosheet for removing of water contaminant. The changes of charge density (Q) have shown a more important charge transfer toward BN nanosheet which acts as the electron acceptor while CH3OH, CHBr2, NaOH and NH3 molecules act as the electron donors. Based on nuclear quadrupole resonance analysis, BN nanosheet represent s enough capability for adsorbing CH3OH, CHBr2, NaOH and NH3 through electric potential values of hydrogen, carbon, nitrogen, oxygen, bromine and boron atoms during adsorption of organic molecule (adsorbate) on BN nanosheet (adsorbent). Besides, NMR spectroscopy exhibited the remarkable peaks around carbon, nitrogen, oxygen and bromine atoms through the adsorption procedure of CH3OH, CHBr2, NaOH and NH3 on the BN nanosheet with the fluctuations in the chemical shielding behaviors of isotropic and anisotropy attributes. All the measured thermodynamic parameters extracts from IR spectrums have exhibit the most stability energy for CHBr2 and CBr2–BN. This work can evaluate the adsorption of different organic contaminants of CH3OH, CHBr2, NaOH and NH3 on the BN-based nanosheet and correspondingly can introduce helpful information for using this nanomaterial in water treatment. [ABSTRACT FROM AUTHOR]

Due to the co-combustion of hydrogen-rich atmosphere and coal in power plants has a great influence on NO X emission, it has been studied by more and more researchers. Therefore, the study of the effect of hydrogen-rich atmosphere on coal pyrolysis mechanism provides a theoretical basis for subsequent application in power plants. In this paper, reaction molecular dynamics simulation is used to investigate the pyrolysis mechanism of Henan anthracite coal within the temperature range of 300–3600 K. The consistency between the activation energy, TG curve, and gas release characteristics derived from the ReaxFF simulation and the experimental results provides evidence for the validity of this method in investigating the pyrolysis mechanism of coal. Furthermore, the pyrolysis behavior of Henan anthracite coal in N 2 , H 2 , and NH 3 atmospheres with varying temperatures are studied. The pyrolysis of Henan anthracite coal can be categorized into three distinct stages under varying atmospheric conditions, as revealed by the simulation findings. Compared with N 2 pyrolysis atmosphere, H 2 and NH 3 pyrolysis atmospheres can reduce the release of CO, reduce the activation energy, promote the degree of pyrolysis and accelerate the pyrolysis process. NH 3 atmosphere has more obvious influence on the coal pyrolysis process. Also, HCN (NO X precursor) generation reactions during pyrolysis are revealed in N 2 , H 2 and NH 3 atmosphere. H 2 and NH 3 pyrolysis atmospheres can increase the number of HCN generation reactions and change the distribution of HCN generation reactions. The analysis of HCN formation reaction shows that CN and H 2 CN are the main precursors of HCN. • Henan coal pyrolysis is studied via ReaxFF MD. • The macromolecular model of Henan coal has been verified. • In NH 3 atmosphere, the activation energy of Henan coal pyrolysis is reduced. • The HCN generation reaction in different atmosphere is proposed. [ABSTRACT FROM AUTHOR]

Regarding two-dimensional (2D) nanomaterials as gas sensors, we have studied the adsorption of gas molecules (NH3, NO2, NO) on the graphitic GaN sheet (PL-GaN) using density functional theory calculations. "Langmuir" adsorption of gas molecules of NH3, NO2, and NO on the graphitic GaN sheet has been accomplished using density functional theory. The changes in charge density have shown a more important charge transfer on the hexagonal honeycomb nanosheet of gallium nitride (GaN) which acts as the electron acceptor while gas molecules act as the stronger electron donors through adsorption on the graphitic-like GaN surface. The adsorption of NH3, NO 2 , and NO, respectively, on GaN nanosheet has more contribution with high expansion curves of hydrogen, nitrogen and oxygen. The results extracted from PDOS curves after optimization show the electron transferring from nitrogen and oxygen of gas molecules (adsorbate/donor) towards gallium in the active site of GaN surface (adsorbent/acceptor). GaN nanosheet represents enough capability for adsorbing gases of NH3, NO2, and NO through charge transfer from nitrogen and oxygen atoms to the gallium atom regarding the intra-atomic and interatomic interactions. Concerning the change of physicochemical properties of the PL-GaN sheet before and after molecule adsorption, the PL-GaN nanosheet can be applied as an appropriate selective gas sensor for NH3, NO2 and NO detection. [ABSTRACT FROM AUTHOR]

The research effort in the microcombustor field has recently increased due to the demand for high-performance systems in microelectromechanical and micro power generation devices. To address rising concerns about pollutants from fossil sources, zero-carbon fuels such as hydrogen (H2) and ammonia (NH3) have been considered as an alternative in microcombustion processes. In a microcombustor, the surface area-to-volume ratio is much higher compared to conventional combustion systems, resulting in faster heat transfer rates and more intense combustion reactions. However, achieving efficient mixing of fuel and an oxidizer in a microcombustor can be challenging due to its small size, particularly for highly reactive fuels like H2. For NH3, challenges in microcombustion involve a low reactive, high ignition temperature (923 K vs. 793 K of H2) and high concentration of NOx combustion products. Therefore, studying the performance of these fuels in microcombustors is important for developing clean energy technologies. In this paper, to explore features of non-premixed NH3/air and H2/air combustion in micro-scale combustors, an Ansys Fluent numerical investigation was conducted on a Y-shaped microcombustor. Results show that for combustion with H2, stationary flames can be achieved even at lower equivalence ratios. Additionally, the pollutants generated from H2 in the flame are generally twice those of NH3. The overall efficiency of the microcombustor is two times greater for NH3 conditions than for H2 conditions. [ABSTRACT FROM AUTHOR]

Mixing carbon-free fuel ammonia into pulverized coal boiler can effectively reduce CO2 emissions from power plants, which has attracted more and more attention in recent years. However, ammonia and coal co-combustion increases the path of NOx formation. The study of NO reduction mechanism in high temperature reduction zone of ammonia and coal co-combustion process is particularly critical to achieve a low-nitrogen emission. Considering that the high-temperature reduction zone is not an oxygen free environment, it is necessary to explore the influence mechanism of micro-oxygen in reduction zone on NO reduction by unburned ammonia coupled coal char. In this paper, the influence mechanism of micro-oxygen concentration (0, 0.5%, 1.0%, 1.5% and 2.0%) on NH3/NO homogeneous and NH3/char/NO heterogeneous reduction is studied in a high temperature horizontal tubular furnace. The temperature range is 1 373−1 773 K. The results show that the efficiency of homogeneous reduction of NO by NH3 increases with the temperature increase under high temperature and oxygen-free environment. When the temperature is higher than 1573 K, the homogeneous reduction of NO by NH3 decreases slightly with the increase of temperature. The optimal reduction temperature of unburned ammonia for NO is 1 573 K. Char significantly improves the efficiency of NO reduction by NH3 at high temperature, and broadens the optimal reduction temperature of NO to 1 673 K. The reduction of NO by char and NH3 is synergistic. Compared with the absence of oxygen, when the temperature is not higher than 1 500 K and the oxygen concentration is within 2.0%, the micro-oxygen promotes the formation of the reduced free radical NH2/NH, which promotes the homogeneous reduction of NO by NH3. Further increasing the temperature is conducive to the oxidation of NH2/NH, so that the homogeneous reduction efficiency of NO by NH3 in the presence of oxygen is lower than that in the absence of oxygen. In the heterogeneous reduction system of NH3/char/NO, when the temperature is not higher than 1 473 K and the oxygen concentration is not higher than 0.5%, the heterogeneous reduction efficiency of NO under micro-oxygen is higher than that without oxygen. With the further increase of oxygen concentration and temperature, the oxidation reaction of NHi with oxidizing radicals such as OH/O is faster than the NO reduction by NHi/char, the reduction efficiency of NO in the NH3/char/NO heterogeneous system decreases. The results indicate that there is an optimal oxygen concentration to promote the reduction of NO by NH3/char in the high temperature reduction zone.

Agonistic behavior is a problem of animal welfare in commercial turkey fattening. In this study, possible influences of the barn layout and the climate of the barn on the behavior of fattening turkeys on a commercial farm were investigated. The study was conducted on a turkey farm with two comparable barns. A modified ventilation system was installed in the trial barn to improve the removal of NH3 and CO2. The drinkers were rearranged to increase the animals’ free floor area. In each barn, 3600 male turkeys (B.U.T. 6) were housed. Videos were recorded continuously from housing until removal for three consecutive fattening periods. NH3 and CO2 values were recorded. Turkeys showed increased activity (p < 0.001) and comfort behavior in the trial barn during late fattening (p = 0.002). Agonistic behavior increased during late fattening, particularly around the drinkers (p < 0.001). NH3 levels differed at the beginning of fattening. The study shows that extending the resting area contributes to increased activity and comfort behavior. The rearrangement of drinkers showed no positive effects on agonistic behavior, as the distance between individual drinkers was too small. Due to behavioral differences being most evident in late fattening, no conclusions can be drawn concerning the influence of CO2 and NH3.

Abstract This study aimed to identify the factors causing NH3 emissions in the South Korean Peninsula and West Sea region. To analyze the trends of NH3 and other air pollutants, such as NOx, CO, and NR-PM1, we collected samples from six supersites across the peninsula, a roadside in Seoul, and the West Sea over different sampling periods, ranging from 1 month to 1 year. The highest NH3 concentrations were found at rural areas, ascribed to agricultural activities, particularly NH4NO3 decomposition at high summer temperatures. Areas with low population densities recorded the lowest NH3 concentrations, attributed to the lack of anthropogenic activities. A roadside field experiment confirmed the close link between ambient NH3 and vehicle emissions in urban regions by showing a strong correlation between CO and NOx concentrations and that of NH3. Moreover, we examined oceanic emissions near the eastern coast of South Korea in the West Sea. Long-range transportation studies confirmed that most of the pollutants (NH3, CO, and PM1) were transported by wind from the northeastern region of China. A maritime origin study showed that oceanic emissions and NH4NO3 decomposition in the atmosphere owing to high temperatures were the causing NH3 pollution. These findings provided valuable insights into the emission sources of NH3 in primary air pollutants in South Korea, highlighting the contributions of land-based and oceanic sources. Our study can help inform policymakers and stakeholders for developing effective regional air pollution control strategies.