68 research outputs found
Autotrophic denitrification of synthetic nitrate-contaminated groundwater in up-flow fixed-bed bioreactor by pumice as porous media
Background: Background: Increasing nitrate concentrations in groundwater resources is considered a
common environmental and public health problem worldwide. In this research, an autotrophic up-flow
bioreactor with pumice as media was used to study the effects of the sulfur-to-nitrogen (S/N) ratio and empty
bed contact time (EBCT) on nitrate removal efficiency and byproducts.
Methods: Experiments were carried out in a 3.47 L up-flow, fixed-bed reactor with 3 sampling ports. To
evaluate the overall impact of S/N ratio and EBCT on the performance of the bioreactor, several phases with
different S/N ratios and EBCTs were applied.
Results: At a constant S/N ratio of 3.85 g/g, as EBCT decreased from 24 hours to 2 hours, the nitrate removal
efficiency decreased from 98% to 64%. On the other hand, at the desired EBCT of 4 hr, as S/N ratio decreased
from 3.85 to 1.51 g/g, nitrate removal efficiency was reduced from 85% to 32%. Changing the EBCT and S/N
ratio also affected the effluent nitrite and sulfate concentrations as byproducts. At the S/N ratio of 3.85 g/g
and EBCT of 24 hours, effluent nitrite and sulfate concentrations were 0.1 mg NO2--N/L and 463 mg SO4
2-/L,
respectively. Decreasing the S/N ratio to 1.51 g/g and the EBCT to 4 hours caused drastic changes in effluent
nitrite and sulfate concentrations.
Conclusion: The results indicated that the autotrophic denitrification with thiosulfate as electron donor and
pumice as media was feasible and applicable for nitrate contaminated groundwater
Study of Phosphorus Uptake by Activated Sludge at Various COD:P Ratios
Bioenvironmental Engineerin
Copper, Cadmium and Ferrous Removal by Membrane Bioreactor
AbstractOne of the important concerns in Tehran municipal landfill is the production of leachate and its potential for water resources pollution. This paper investigates the removal of heavy metals from landfill leachate by using a membrane Bioreactor (MBR). The leachate was collected from a landfill in the vicinity of Tehran nearly 1 year old, The results of this study indicated that the system provided high removals of Fe, Cu and Cd equal to 96%, 23% and 84% respectively and heavy metal concentration in MBR effluent is a function of aeration ratio and bioaccumulation. Among the metals investigated in the present study it can be concluded that the extracellular adsorption, is the principal removal process of the metals, compared to other removal mechanisms such as bioaccumulation or intracellular accumulation
Comparison of Intravenous Midazolam Drip with Intermittent Intravenous Diazepam in the Treatment of Refractory Serial Seizures in Children
How to Cite this Article: Fayyazi A, Karimzadeh P, Torabian S, Damadi S, Khaje A. Comparison of Intravenous Midazolam Drip with Intermittent Intravenous Diazepam in The Treatment of Refractory Serial Seizures in Children. Iran J Child Neurol 2012; 6(3): 15-19. ObjectiveSerial seizures occur commonly in inpatient epileptic children. This type ofseizure due to its characteristics has a significant impact on the patient’s health.Untreated serial seizures lead to status epilepticus; therefore, finding a moreeffective treatment for such patients is essential. This study was performed tocompare the outcome of intermittent intravenous diazepam in the pediatricneurology clinic and intravenous midazolam in the pediatric intensive care unit(PICU), in order to introduce an alternative treatment for serail seizures.Materials & MethodsIn this study, 38 inpatient children aged 6 mo-15 years with refractory serialseizures were treated by first line antiepileptic drugs and then randomlytreated with either intermittent intravenous diazepam in the neurology ward orintravenous midazolam in PICU.ResultsFourteen (70%) diazepam group patients and 13 (72.2%) midazolam grouppatients had good response to treatment, there was no significant differencebetween the two groups. Four midazolam group patients and two diazepamgroup patients needed mechanical ventilation and were intubated duringtreatment, with no significant difference between the two groups. Durationsof mechanical ventilation and PICU and hospital stay were not significantlydifferent between the two groups.ConclusionIntermittent intravenous diazepam is an effective alternative therapy formidazolam drip in the treatment of serial seizures due to similar therapeuticeffects and fewer side effects.ReferencesHaut SR. Seizure clustering. Epilepsy Behav 2006Feb;8(1):50-5.Caraballo RH, Cersosimo RO, Fejerman N. Benign focal seizures of adolescence: a prospective study. Epilepsia 2004 Dec;45(12):1600-3.Haut SR, Swick C, Freeman K, Spencer S. Seizureclustering during epilepsy monitoring. Epilepsia 2002 Jul;43(7):711-5.Yen DJ, Chen C, Shih YH, Guo YC, Liu LT, Yu HY,et al. Antiepileptic drug withdrawal in patients with temporal lobe epilepsy undergoing presurgical video-EEG monitoring. Epilepsia 2001 Feb;42(2):251-5.Rose AB, McCabe PH, Gilliam FG, Smith BJ, Boggs JG,Ficker DM et al. Occurrence of seizure clusters and status epilepticus during inpatient video-EEG monitoring.Neurology 2003 Mar;60(6):975-8.Newmark ME, Dubinsky S. The significance of seizure clustering: a review of 343 outpatients in an epilepsy clinic. In:Dreifuss FE, editor. Chronopharmacology intherapy of the epilepsies. New York: Raven Press; 1990.p. 89-103.Newmark ME, Penry JK. Catamenial epilepsy. In: Dam,Gram L, Penry JK. editors. Advances in epileptology:XII Epilepsy International Symposium.1980. p. 433-9.8. Bauer J, Burr W. Course of chronic focal epilepsy resistantto anticonvulsant treatment. Seizure 2001 Jun;10(4):239-46.9. Balish M, Albert PS, Theodore WH. Seizure frequencyin intractable partial epilepsy:a statistical analysis.Epilepsia 1991 Sep-Oct;32(5):642-9.Lombroso CT. Intermittent home treatment of status andclusters of seizures. Epilepsia 1989;30 (Suppl 2):S11-4.Mitchell WG. Status epilepticus and acute repetitiveseizures in children, adolescents and young adults:etiology, outcome and treatment. Epilepsia. 1996; 37(Suppl 1):S74-80.Haut SR, Shinnar S, Moshe SL, O’Dell C, Legatt AD.The association between seizure clustering and status epilepticus in patients with intractable complex partial seizures. Epilepsia. 1999 Dec;40(12):1832-4.Dreifuss FE, Rosman NP, Cloyd JC, Pellock JM,Kuzniecky RI, Lo WD et al. A comparison of rectaldiazepam gel and placebo for acute repetitive seizures.New Engl J Med. 1998 Jun;338(26):1869-75.Kriel RL, Cloyd JC, Hadsall RS, Carlson AM, Floren KL,Jones-Saete CM. Home use of rectal diazepam for clusterand prolonged seizures: efficacy, adverse reactions,quality of life, and cost analysis. Pediatr Neurol. 1991Jan-Feb;7(1):13-7.Ozdemir D, Gulezb P, Uranb N, Yendur G, Kavakli T,Aydin A. Efficacy of continuous midazolam infusion andmortality in childhood refractory generalized convulsive status epilepticus. Seizure. 2005 Mar;14(2) 129-32.16. Bhattacharyya M, Kalra V, Gulati S. Intranasal midazolam vs rectal diazepam in acute childhood seizures. PediatrNeurol. 2006 May;34(5):355-9.Lahat E, Goldman M, Barr J, Bistritzer T, BerkovitchM. Comparison of intranasal midazolam with intravenous diazepam for treating febrile seizures in children:prospective randomised study. BMJ. 2000Jul;321(7253):83-6.Hayashi K, Osawa M, Aihara M, Haginoya K, KatoI, Kaneko K et al; Research Committee on Clinical Evidence of Medical Treatment for Status Epilepticusin Childhood. Efficacy of intravenous midazolam forstatus epilepticus in childhood. Pediatr Neurol. 2007Jun;36(6):366-72.Scott RC, Besag FM, Neville BG. Buccal midazolam and rectal diazepam for treatment of prolonged seizures in childhood and adolescence: a randomised trial. Lancet.1999 Feb;353(9153):623-26
Determining the best practicable control technology and its associated emission levels for Iron and Steel industry in Iran
Industrial effluent limitations should be established regarding the special characteristics of each sector with emphasis given to the local context, whereas, in Iran, a uniform “Wastewater Effluent Standard” is employed throughout the country in which no specific industrial effluent limitations have been considered. This gap highlights the essential need for a transparent and scientifically proven methodology for determining effluent emission limit values (ELVs) at the sector level. In this research, an integrated approach is proposed based on the application of the Best Practicable Control Technology Currently Available (BPT) concept. The modelling framework includes a series of sequential steps comprising two main sections: 1. identifying the effluent emission datasets, and 2. computing the emission levels associated with the BPT (BPT-AELs). To identify the datasets, the methodology follows two different procedures: 1. a detailed analysis of the environmental performance of this sector in the country to determine the plants reflecting BPT, and 2. screening their emission datasets through statistical analysis. The Best Available Techniques (BAT) principle is employed as a reference element for determining the best representative plants, and the results indicate that corrective measures in accordance with the BAT considerations should be implemented in many of the plants under consideration. The comparison of the derived BPT-AELs with the existing standards show that they are mainly lower than the standard levels and are reasonable estimations for the involved parameters. Conclusively, this methodology presents a reliable and practical stepwise process at the sector level, which can be developed for other industries
Emulating the Human Mind: A Neural-symbolic Link Prediction Model with Fast and Slow Reasoning and Filtered Rules
Link prediction is an important task in addressing the incompleteness problem
of knowledge graphs (KG). Previous link prediction models suffer from issues
related to either performance or explanatory capability. Furthermore, models
that are capable of generating explanations, often struggle with erroneous
paths or reasoning leading to the correct answer. To address these challenges,
we introduce a novel Neural-Symbolic model named FaSt-FLiP (stands for Fast and
Slow Thinking with Filtered rules for Link Prediction task), inspired by two
distinct aspects of human cognition: "commonsense reasoning" and "thinking,
fast and slow." Our objective is to combine a logical and neural model for
enhanced link prediction. To tackle the challenge of dealing with incorrect
paths or rules generated by the logical model, we propose a semi-supervised
method to convert rules into sentences. These sentences are then subjected to
assessment and removal of incorrect rules using an NLI (Natural Language
Inference) model. Our approach to combining logical and neural models involves
first obtaining answers from both the logical and neural models. These answers
are subsequently unified using an Inference Engine module, which has been
realized through both algorithmic implementation and a novel neural model
architecture. To validate the efficacy of our model, we conducted a series of
experiments. The results demonstrate the superior performance of our model in
both link prediction metrics and the generation of more reliable explanations
The application of hybrid model for identifying and ranking indicators for assessing the sustainability of waste water treatment systems
This paper proposes a combination of the Fuzzy Delphi and Fuzzy Analytic Hierarchy Process (FAHP) as an efficient tool for dealing with complex decision-making problems and to prove that integrating the Fuzzy Delphi and FAHP modeling is an objective and practical process. The application of these methods allows a large amount of information to be aggregated in a rigorous manner. The suggested fuzzy set theory helps to represent the uncertainty and vagueness of human’s subjective thinking process in dealing with decision problems. This hybrid approach enables decision-makers to evaluate priorities more efficiently and objectively and make the decision process more reliable. Therefore, the main goal of the present research is to develop this decision support approach to identify the key evaluation criteria and indicators in the process of selecting industrial wastewater treatment technology (WTT) from a sustainability perspective based on expert opinion and questionnaires. Since a realistic evaluation needs to be conducted in an actual condition, Iran’s steel industry was selected as the case study. In this research, based on the findings of the literature review and Fuzzy Delphi method screening, several evaluation criteria and indicators are identified. Then, the FAHP is employed to examine their relationships under a hierarchy structure and to determine their weights and priorities. The findings of this paper can be applied as a reference for the steel industry in decision-making for the selection of the optimal wastewater treatment technology. In addition, other industries can apply this feasible and practical approach in their decision-making process with respect to their differences in capacities, limitations, wastewater characteristics and local conditions
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