Methane–air detonation experiments at NIOSH Lake Lynn Laboratory

The methane–air detonation experiments are performed to characterize high pressure explosion processes that may occur in sealed areas of underground coal mines. The detonation tube used for these studies is 73 m long, 105 cm internal diameter, and closed at one end. The test gas is 97.5% methane with about 1.5% ethane, and the methane–air test mixtures varied between 4% and 19% methane by volume. Detonations were successfully initiated for mixtures containing between 5.3% and 15.5% methane. The detonations propagated with an average velocity between 1512 and 1863 m/s. Average overpressures recorded behind the first shock pressure peak varied between 1.2 and 1.7 MPa. The measured detonation velocities and pressures are close to their corresponding theoretical Chapman-Jouguet (CJ) detonation velocity (D_CJ) and detonation pressure (P_CJ). Outside of these detonability limits, failed detonations produced decaying detached shocks and flames propagating with velocities of approximately 1/2 D_CJ. Cell patterns on smokefoils during detonations were very irregular and showed secondary cell structures inside primary cells. The measured width of primary cells varied between 20 cm near the stoichiometry and 105 cm (tube diameter) near the limits. The largest detonation cell (105 cm wide and 170 cm long) was recorded for the mixture containing 15.3% methane.     

Statistical fault detection using PCA-based GLR hypothesis testing

Safe process operation requires effective fault detection (FD) methods that can identify faults in various process parameters. In the absence of a process model, principal component analysis (PCA) has been successfully used as a data-based FD technique for highly correlated process variables. Some of the PCA detection indices include the T² or Q statistics, which have their advantages and disadvantages. When a process model is available, however, the generalized likelihood ratio (GLR) test, which is a statistical hypothesis testing method, has shown good fault detection abilities. In this work, a PCA-based GLR fault detection algorithm is developed to exploit the advantages of the GLR test in the absence of a process model. In fact, PCA is used to provide a modeling framework for the develop fault detection algorithm. The PCA-based GLR fault detection algorithm provides optimal properties by maximizing the detection probability of faults for a given false alarm rate. The performance of the PCA-based GLR fault detection algorithm is illustrated and compared to conventional fault detection methods through two simulated examples, one using synthetic data and the other using simulated continuously stirred tank reactor (CSTR) data. The results of these examples clearly show the effectiveness of the developed algorithm over conventional methods.     

Enhancing mesophilic anaerobic co-digestion of slaughterhouse waste with household waste under a pilot-scale reactor

Journal of Material Cycles and Waste Management - In this investigation, mesophilic co-digestion of both slaughterhouse waste (SHW) with household waste (HSW) was carried out using a 50 L...     

Solar photo-oxidation of recalcitrant industrial wastewater: a review

Conventional methods to clean wastewater actually lead to incomplete treatments, calling for advanced technologies to degrade recalcitrant pollutants. Herein we review solar photo-oxidation to degrade the recalcitrant contaminants in industrial wastewater, with focus on photocatalysts, reactor design and the photo-Fenton process. We discuss limitations due to low visible-light absorption, catalyst collection and reusability, and production of toxic by-products. Photodegradation of refractory organics by solar light is controlled by pH, photocatalyst composition and bandgap, pollutant properties and concentration, irradiation type and intensity, catalyst loading, and the water matrix.

     

Respiratory,hepatic, renal,and hematological disorders among adolescent females environmentally exposed to pesticides,Menoufia governorate,Egypt

Environmental Science and Pollution Research - Adolescent females are often environmentally exposed to pesticides by living near agricultural fields, by using pesticides at home, or by having...     

Reducing ammonia emission by aluminum sulfate addition in litter and its influence on productive,reproductive, and physiological parameters of dual-purpose breeding hens

Environmental Science and Pollution Research - This research investigated the impact of aluminum sulfate (AS) as amendment to different types of litter (new, reused, and mixed litters) for reducing...     

Taguchi optimization of geopolymer concrete produced with rice husk ash and ceramic dust

Environmental Science and Pollution Research - Metakaolin, fly ash, and mostly granulated blast furnace slag (GBFS) are traditionally used in the production of geopolymer. This study, adding to the...     

Association of heat shock protein70-2 genotypes with hypertension among textile workers occupationally exposed to noise

Environmental Science and Pollution Research - Noise exposure is a primary cause of hearing loss with a broad range of auditory and non-auditory effects. It is one of the occupational health risks...     

Pharmacological and ameliorative effects of Withania somnifera against cadmium chloride–induced oxidative stress and immune suppression in Nile tilapia,Oreochromis niloticus

This study was carried out to evaluate the effects of dietary supplementation of aqueous extract of Withania somnifera (W. somnifera) against cadmium chloride–induced toxicity in the Nile tilapia, Oreochromis niloticus. Five experimental groups were designed: group (I) was free from cadmium chloride and W. somnifera and served as a control, group (II) was exposed to 1.775 mg L^?1 of cadmium chloride only (which is equivalent to 1/4 96-h LC50), while groups (III), (IV), and (V) were exposed to 1.775 mg cadmium chloride L^?1 with co-supplementation of dietary W. somnifera in doses of 1.0, 2.0, and 3.0 mL kg^?1 body weight (bwt), respectively. The experiment lasted for 4 weeks. In the second and fourth weeks of the experiment, the following indicators were evaluated: hematological (hemogram and blood protein profile), biochemical (activities of serum liver enzymes, namely alanine transaminase (ALT) and aspartate transaminase (AST)), immunological (immunoglobulin M (IgM), serum lysozyme), and tissue antioxidant changes (malondialdehyde (MDA) levels and activities of catalase (CAT) and superoxide dismutase (SOD)). Additionally, gene expressions of glutathione-S-transferase (GST) in the liver were assessed. At the end of the experiment, all fish in all groups were experimentally challenged with Aeromonas hydrophila and the relative protection survival (RPS) was demonstrated. The results revealed that groups exposed to cadmium chloride toxicity and co-supplemented with dietary aqueous extract of W. somnifera at high doses showed significant ameliorative effects in hemogram parameters, total protein, globulin, IgM, and lysozyme against cadmium chloride–induced toxicity compared to the control group and the group exposed to a sublethal dose of cadmium chloride without co-suplemntation of W. somnifera. The results showed also that groups supplemented orally with W. somnifera at high doses have higher antioxidant activities of CAT and SOD and reduction of MDA formation. Levels of gene expressions of GST in the liver were higher in W. somnifera extract-supplemented groups more than those in the group exposed to cadmium chloride–induced toxicity without W. somnifera supplementation. In addition, the results revealed improved RPS with the dietary supply of W. somnifera extract in high doses. In conclusion, this study showed that the dietary supplementation of W. somnifera extract to diets of O. niloticus could be suggested as an effective way to overcome cadmium chloride–induced toxicity because it improves blood parameters and antioxidants, and it can be used as an immunostimulant against the invading bacterial pathogens.

     

Impact of ginseng on neurotoxicity induced by cisplatin in rats

Environmental Science and Pollution Research - Over the years, many researches have shown the potential protective effects of ginseng for preventing and treating neurological damage and their...