Search

Exposure to high doses of ammonia gas can result in lethal injuries to humans. This case series presents 5 fatalities and an injured individual, caused by acute ammonia exposure, which occurred in the rubber industry. One of the fatalities and the survivor were reported in an incident of ammonia gas cylinder explosion, whereas the other 4 fatalities were accidentally exposed to gaseous ammonia, where they had started working at a reopened rubber factory that had been abandoned for a long time. Autopsy, scene investigation, and the toxicological findings of the deceased and the clinical forensic examination of the survivor revealed corrosive burns on the skin and the oropharynx, diffuse alveolar damage, and high level of ammonia in blood and the scene. These cases highlight how the comprehensive death investigation helps the forensic practitioner to conclude ammonia exposure as the cause of death/injury where there is a possibility of gas inhalation.

Recently, ammonia has become more attractive for carbon-neutral transportation. Both aqueous ammonia and gaseous ammonia can be utilized for direct ammonia hydroxide exchange membrane fuel cells (D...

A 2D/0D heteronanostructure (HNS) employing WSe2 as 2D nanosheets and Fe3O4 as 0D nanoparticles has been facilely synthesized at room temperature using a simple wet chemical route. The process invo...

Excessive emission of ammonia (NH3) gives rise to a number of negative effects on the environment and human health. Photocatalysis is an efficient method to eliminate gaseous NH3; however, photocat...

In this article, we report an efficient and mild synthetic route for the construction of substituted quinazolines from functionalized 2-aminobenzophenones with various benzaldehydes using cat. TMSOTf and hexamethyldisilazane (HMDS) under neat, metal-free and microwave irradiation conditions in which gaseous ammonia was formed in situ. This synthetic protocol provided the desired quinazolines with a broad substrate scope in good to excellent yields. Some structures were confirmed by X-ray single-crystal diffraction analysis.

In Vietnam, practical applications of biological methods in air pollution control are highly limited. This study evaluated and compared the ammonia removal performance in air of a cow-manure biofilter, commercial compost biofilter, and biotrickling filter with K3 biomedium cultured with attached microorganisms from activated sludge. The results indicated that with an inlet NH3 concentration of 65-80 mg/m3 (95-117 ppm), the treatment efficiency was highly promising with an output concentration in the range of 2-5 mg/m3 (3.0-7.5 ppm) and elimination capacity of 3-9 gNH3/m3.h. With an inlet concentration below 200 mg/m3, all three experimental models could remove ammonia to meet the emission standard (QCVN 19:2009/BTNMT) of 50 mg/m3. The study results indicated that the investigated biological technologies have potential for use in removing ammonia and other odorous gases in polluted air. This study investigated the removal of gaseous ammonia using cow manure, compost, and K3 material as biomedium in biofilters and biotrickling filters.

The prevention of emergencies (accidents) at potentially hazardous objects is an urgent problem of modern production. The most common method of assessing the hazards and accidents of production is to develop formalized models of events – the use of the Fault Tree Analysis (FTA) method. Tree of failures is a directed logical tree that describes the occurrence of an accident from result to cause. Ammonia refrigeration units are used to produce artificial cold at food and processing enterprises. They are potentially hazardous objects, and accidents due to ammonia toxicity and the location of businesses in settlements can have serious consequences. Some features of emergency modelling are considered on the example of ammonia transportation pipelines within the ammonia refrigeration unit. The causes of pipeline damages that can lead to emergencies at ammonia pipelines are identified. Ammonia leaks and emissions can only occur if pipelines are broken or destroyed. Based on the analysis of emergencies on pipelines, the variant of the graph of tree of failures is developed for pipelines of ammonia refrigeration units. The initiating event in the emergency sequence is the emission (spillage) of ammonia. A probable scenario of accident development in the case of damage to pipelines with liquid and gaseous ammonia is developed. Leakage or emission of ammonia will occur if the pipeline leaked, which can lead to the formation of a toxic cloud indoors or outdoors, the intoxication of personnel, the migration of a toxic cloud within the enterprise or beyond. Through the research of the mutual effects of failures of the main elements of the pipeline we identified possible scenarios for the development of an emergency and using the construction of tree of failures shows the causes of failures of the elements of the pipeline. As a result, the FTA logic-probabilistic model can used to analyse the technogenic hazard of ammonia pipelines, enabling the prediction of accidents and emergencies.

The influence of the parameters (laser linewidths and profiles) of the CO2 laser based on the main molecular isotope on the absorption coefficient of a gaseous compound is analyzed using ammonia as an example. Results of application of the CO2 laser for the determination of the gaseous ammonia content are considered and possible errors in calculating the gas concentration caused by the neglect of the specific spectral linewidth of the CO2 laser are analyzed.

International audience; From theoretical calculations validated by the results of experiments, it was shown that the properties of the washing liquid that flows into biotrickling filters at livestock facilities determine the maximum ammonia removal efficiency (RE) that can be achieved. For a well-designed biotrickling filter not limited by hydrodynamic conditions, the ammonia driving force is mainly controlled by the pH, and also by the electrical conductivity (EC L), although to a lesser extent. With the washing liquid at a given temperature, therefore, the removal efficiency depends on the gaseous ammonia concentrations to be treated (C Gin ; usually lower than 20 mg NH3 m-3) and on the values of the pair (pH, EC L). Theoretical prediction of the maximum removal efficiency that can be achieved by simply measuring the properties of the washing liquid, in line or from samples, could be a useful diagnostic tool to identify possible failure of the apparatus and to manage the electrical conductivity to guarantee removal efficiency at a desired rate.

Palladium-catalyzed hydroaminocarbonylation of alkenes for the synthesis of primary amides has long been an elusive aim. Here, we report an efficient catalytic system which enables inexpensive NH4Cl to be utilized as a practical alternative to gaseous ammonia for the palladium-catalyzed alkene-hydroaminocarbonylation reaction. Through appropriate choice of the palladium precursors and ligands, either branched or linear primary amides can be obtained in good yields with good to excellent regioselectivities. Primary mechanistic studies were conducted and disclosed that electrophilic acylpalladium species were capable of capturing the NH2-moiety from ammonium salts to form amides in the presence of CO with NMP as a base.

Correction for ‘Graphene materials as a superior platform for advanced sensing strategies against gaseous ammonia’ by Kumar Vikrant et al., J. Mater. Chem. A, 2018, 6, 22391–22410.

In this work we present a Eu(III) tris-benzoylacetonate complexes as efficient luminescent chemosensor for gaseous ammonia. It is shown that luminescent and sensor properties of studied samples can be varied by using organic solvents. In dependence of organic solvent type it is possible to create each of one-time-use express sensor systems and continuous monitoring systems. The mechanism of the effect of ammonia vapors on intensification of the Eu(III) luminescence has been suggested using the data of IR spectroscopy and quantum chemistry calculations.

A real-time colorimetric sensor array (CSA) offers the advantages of diversity and accuracy for the quantification of multiple analytes; however, traditional sensors require a complex fabrication process. Therefore, to take full advantage of this sensing platform, we have developed a simple CSA system composed of a polymer, a reducing agent, and different pH indicators. Distinctive color response patterns were classified by extracting the hidden information, (i.e., red, green, and blue (RGB) values) from the indicators. This triple-channel sensing platform is further applied for statistical analysis, to quantify different concentrations of ammonia and other analytes. The sensor array showed a limit of detection of 0.3 ppm, which is well below the diagnostic criteria for ammonia concentration in the breath of healthy individuals and of patients with end-stage renal disease. As this sensor would be able to quantify gaseous ammonia in the breath, it is relevant to the point-of-care diagnosis of patients with renal diseases.

A list of gaseous odorants such as ammonia (and hydrogen sulfide) are generally collected using rigid containers or flexible bags for quantitative analysis. The aim of this investigation was to assess the stability of polyester aluminum bags used for gaseous ammonia sampling and storage. To this end, ammonia standards were prepared at two concentration levels of low (7.8 ppm) and high concentrations (39 ppm) and stored in the polyester ammonia bags for durations of 0, 1, 2, 4, and 6 days. These samples were then analyzed at each interval by an impinger-based indophenol method utilizing a spectrophotometer. At each pre-set period, three different mass loadings of ammonia samples were collected from the storage bag to obtain response factors (RF) for comparison between different elapsed times set for the storage. Subsequently, the relative recovery values for each interval were computed by dividing the RF for each sampling day by that of the 0th day. The relative recovery values for low and high concentration standards decreased with increasing storage time as 82.9% (day 1) to 36% (day 6) and 89.9% (day 1) to 59.7% (day 6), respectively. As such, the potentially superior recovery of ammonia from polyester aluminum bags was demonstrated (e.g., relative to other storage options introduced previously) to support its practical merit as storage media.

Infinite coordination polymers are recognized as excellent platform for functionalization. Dithienylethene motifs, which are one of the most attractive functional moieties, were incorporated into an infinite coordination polymer, to deliver a “smart” porous material that can response to external stimuli. The obtained dithienylethene-based infinite coordination polymers (named Cu-DTEDBA) share the advantages of both infinite coordination polymers (porosity and stability) and dithienylethene motifs (photochromism). The physical and chemical properties of Cu-DTEDBA were characterized by FTIR, TEM, SEM, XRD, TGA, UV–vis, EDX and BET. Moreover, the combination of dithienylethene and infinite coordination polymers gives rise to a synergistic effect, which induces functional behaviors of ammonia sensor applications. Both open and closed forms of Cu-DTEDBA exhibit distinct colorimetric change upon exposure to gaseous ammonia, which is not observed in dithienylethene free molecules.

Nowadays the legislative regulation on emissions of Diesel engines is stringent such that an aftertreatment system is necessary. To reduce vehicle NO x emission, a selective catalytic reduction (SCR) system is widely used for Diesel-engine applications. In the SCR system, the gaseous ammonia plays a significant role which is utilized as the reduction to eliminate the NO x emission. To facilitate the NO x reduction, a NO x sensor and an ammonia sensor placed before the SCR catalyst are a good strategy. However, physical sensors would increase the system cost and diagnosis challenge. To reduce the number of physical sensors, in this paper, observers are designed with the assist of extended Kalman filter (EKF) to estimate the NO x or ammonia concentrations before the SCR catalyst. Simulation results show that the designed observers based on EKF can achieve the prescribed objectives quite well. HighlightsEKF algorithm is applied to SCR system.Inputs and states are estimated simultaneously.Proposed method is verified via a well-developed simulator.

Ammonia (NH3) is one of the most abundant inorganic pollutants present in air. Efficient and rapid detection of ammonia is important to maintain the quality of air in both indoor as well as outdoor environment. Among various sensing principles, resistive sensing is a very popular option for the accurate detection of ammonia levels. Further, out of all the materials for sensing applications, polyaniline (PANI) is reported as a highly recommendable option for the construction of such sensing system. Specifically, the utility of PANI modifed by a facile electrospinning method has been demonstrated in the fabrication of efficient sensing systems for gaseous ammonia. This review was organized to offer insight into the potential utility of electrospinning approaches in the construction of PANI-based chemoresistive sensors for gaseous ammonia. The reliability of diverse electrospun PANI-based sensing systems for ammonia was assessed based on a comprehensive evaluation of their performance with respect to key sensing parameters (e.g., sensitivity, selectivity, response time, and limit of detection).

Chemi-resistive ammonia sensors based on α-MoO3 are a simple and selective technology for measuring the concentration of gaseous ammonia [1-4]. Typically, the sensor consists of an interdigitated electrode substrate covered with the α-MoO3 film [2-4]. The measured electrical resistance of the α-MoO3 film on the substrate changes as a function of gaseous ammonia concentration to which the film is exposed. α-MoO3 is a n-type semiconductor [4], meaning that the electrical conductivity of α-MoO3 is dominated by free electrons as opposed to holes. The mechanism of ammonia sensing by n-type semiconducting metal oxides is commonly attributed to the alteration of the charge depletion layer (Λ) of the metal oxide particles through the reaction of ammonia with adsorbed oxygen species [4-10]. For n-type semiconducting metal oxides, the charge depletion layer model predicts that the resistance of the sensing film (α-MoO3) decreases with increasing concentration of reducing gas, such as ammonia, to which the sensor is exposed. In addition to the charge depletion layer model, other sensing mechanisms have been suggested, such as the partial reduction by ammonia of the surface of the MoO3 film and the formation of oxygen vacancies in the MoO3 lattice [1, 2, 11]. It is generally understood that the sensitivity of the sensor can be tailored based on the particle size and morphology of the metal oxide film [5-10]. Therefore, as initial work, sensors with α-MoO3 films of varying morphology on gold-interdigitated electrodes with alumina substrate (DropSens P/N: IDEAU200) were fabricated by Reactive Spray Deposition Technology (RSDT) and tested for sensitivity to ammonia in synthetic air at 400ºC. This work was presented at the 236th ECS meeting as an oral presentation, “Ammonia-Sensing Properties of α-MoO3 Fabricated by Reactive Spray Deposition Technology (RSDT).” From these sensors, the sensor with the strongest response to ammonia was selected for further testing in ammonia and synthetic air at 400ºC with constant 1V DC bias across the sensor. This additional testing consisted of three 12-hour cycles, in which six ammonia concentrations were tested: 0.1, 0.3, 0.5, 1, 3, and 4.9ppm. Between each concentration, the sensor was flushed with synthetic air. Between each 12-hour cycle, the sensor was held at 400ºC in synthetic air for approximately 12 hours. For each ammonia concentration in each cycle, the sensing response (S) was calculated as S=Rgas/Rair where Rgas is the resistance of the sensor for a particular concentration of ammonia and Rair is the resistance of the sensor for the air flush immediately before the particular concentration of ammonia. Sensing results are shown in Figure 1. The results from cycle to cycle are quite repeatable; however, the results consistently depart from the prediction of the charge depletion layer model between 3ppm and 4.9ppm. In an attempt to assess whether these unexpected results could be attributed to morphological or crystallographic changes in the MoO3 film, SEM images and XRD plots were compared before and after the three 12-hour test cycles. SEM images were taken on both the gold and alumina portions of the electrode. Figures 2 and 3 show the SEM images and XRD plots, respectively. Neither SEM nor XRD results suggest that the unexpected sensing behavior may be attributed to morphological and/or crystallographic changes of the MoO3 film. To better explain the sensing behavior, additional testing, including electrochemical impedance spectroscopy (EIS) and X-Ray photoelectron spectroscopy (XPS), will be performed on the sensor. XPS has been reported to provide information regarding the partial reduction of the surface of the MoO3 film [1]. EIS can be used to develop equivalent circuits that are representative of the sensor. It has been shown that different properties of the sensing film, such as grain size and particle contact, correspond to different equivalent circuits [12]. Therefore, EIS data at varying ammonia concentrations can help to develop an understanding of the film properties involved in the sensing mechanism. Results from EIS, XPS, SEM, and XRD, along with an understanding of the charge depletion layer model, will be used to propose a thorough ammonia sensing mechanism for α-MoO3. References 1. A. Prasad, etal. Thin Solid Films. 436 2003 pp. 46-51. 2. P. Gouma, etal. IEEE Sensors Journal. 18 (1) 2010 pp. 49-53 3. A. Güntner, etal. Sensors and Actuators B. 223 2016 pp. 266-273. 4. D. Kwak, etal. ACS Appl. Mater. Interfaces. 11 2019 pp. 10697-10706 5. C. Rout, etal. Nanotechnology. 18 2007. 6. M. Franke, etal. Small. 2 (1) 2006 pp. 36-50. 7. P. Feng, etal. Appl. Phys. Letters. 87 (213111) 2005 8. Y. Chen, etal. Nanotechnology. 17 2006 pp. 4537-4541. 9. V. Sysoev, etal. Nano Letters. 6 (8) 2006 pp. 1584-1588. 10. H. Ogawa, etal. Journal of Applied Physics. 53 1982 pp. 4448-4455. 11. A. Prasad, etal. Sensors and Actuators B. 93 2003 pp. 25-30. 12. N. Barsan, etal. Fresenius Journal of Analytical Chemistry. 365 1999 pp. 287-304. Figure 1

As an adsorbent of gaseous ammonia, cobalt hexacyanocobaltate (CoII3[CoIII(CN)6]2) was proved to have good sorption even at high temperatures, with thermal recyclability in sorption–desorption cycles. The maximum sorption capacities evaluated with a dual-site Langmuir model are 25.2, 18.6, 8.6, and 2.1 mmol g−1 at 20, 100, 150, and 250 °C, respectively.

Ammonia (NH3) as a free gaseous molecule is produced in mammalian cells via an array of metabolic pathways. Its importance as a metabolic product and a fundamental element in the make-up of macromolecules has been recognized, but its participation and contribution to cellular signaling processes have been largely overlooked. This chapter discusses the endogenous generation, metabolism, and biological functions of gaseous ammonia under physiological and pathological conditions, such as hyperammonemia and hepatic encephalopathy. The role of ammonia as a gasotransmitter is specially examined, considering its unique and different properties from those of other gasotransmitters.

Background:Evidence concerning the health effects of exposure to fine particulate matter less than 2.5 μm in diameter (PM2.5) and particulate components such as ammonium (NH4+) is limited. We aimed to investigate gaseous ammonia (NH3), particulate ammonium (NH4+), the total concentration of these po

Although much of the toxicology of gases (matter consisting of particles that has neither a defined volume nor a defined shape at standard temperatures and pressures) is applicable to the toxicology of vapors, this chapter focuses on substances that meet the criteria for classical gases. The chapter is divided into two overarching sections: general principles and specific toxic gases. Issues pertaining to toxicokinetics and basic dosimetric adjustments for human risk assessment are covered in the general principles section. The section on specific toxic gases covers gases that are of veterinary significance as well as the toxic gases that humans (including veterinarians) are likely to be exposed to in clinical and agricultural settings, such as carbon monoxide, hydrogen sulfide, oxides of nitrogen (silo filler’s disease), gaseous ammonia (including anhydrous ammonia), and smoke inhalation.

Strategies of regulated irrigation and fertilization are one of the most practical ways in saving irrigation water and N-fertilizer of farmland in arid and semi-arid regions. A field experiments were conducted in the two winter seasons of 2012/2013 and 2013/2014 on clay soil to investigate the effect of 3, 4 and 5 irrigation events and their interaction with two N-fertilization levels using ammonia gas; 75 and 90 kg N fed−1 which represent 100% and 120% of nitrogen recommended dose, respectively on wheat water consumptive use, grain yield, yield components and water productivity (WP) of three Egyptian wheat varieties; Misr-1, Misr-2 and Sakha-94 and compare the estimated wheat crop evapotranspiration (ETc) values computed using Hargreaves, Penman–Monteith and Class A pan methods with the measured actual wheat evapotranspiration (ETa) to evaluate the suitable method for estimating the reference evapotranspiration in North Nile Delta conditions. The obtained results showed that the irrigation treatments (3 events) gave the lowest values for water consumptive use, grain, straw, biological yield and 1000-grain weight. Nitrogen fertilizer in ammonia up to 90 kg N fed−1 decreased all characters studied except grain yield which has no any significant differences between both N levels. Significant differences were detected among the three wheat varieties in all characters studied during both seasons and their interaction with the other treatments combined. Misr-1 cultivar was superior and gave the highest value of all studied characters and yield response to water factor (Ky) followed by Misr-2 while Sakha-94 showed the lowest values in all studied characters. Thus, Misr-1 cultivar proved to be more tolerant cultivar to drought followed by Misr-2 and Sakha-94. WP decreased with increasing irrigation events and nitrogen levels, and reached the maximum values at three irrigation treatments (3 events) and at 90 kg N fed−1. So, irrigating the wheat 4 events during growing seasons and application of 75 kg N fed−1 in the form of ammonia gave the highest values of yield and yield components of Misr-1 wheat cultivar under North Nile Delta condition. Also, results showed that FAO Penman–Monteith is a suitable method for North Delta, Egypt, because of the least amount of error and least percentage deviation between ETa and ETc comparing with the other evaluated methods.