Membrane Distillation: Basics, Advances, and Applications

Membrane technology as an emerging separation process has become competitive with other separation techniques in recent decades. Among pressure-driven and isothermal membrane processes, membrane distillation (MD) as a thermally driven process has come out to put an end to hardships of such processes like distillation. MD process can be used in a wide variety of applications such as desalination and wastewater treatment. Generally, MD is a process which water is a main component of the feed solution and only water vapor can pass through a hydrophobic membrane pores. With four main configurations different from each other by their condensation procedure, the performance of MD process is limited due to the lack of appropriate module, membrane, and energy consumption rate. In recent years, many experiments have been carried out to find well-suited membrane type and module. Also, applying solar or waste heat as heat source and the capability of coupling with other processes like forward osmosis and osmotic distillation distinguish MD process from other membrane processes. This chapter addresses membrane characteristics, MD applications, transport mechanisms, and process challenges

A model of the factors predicting English language teacher immunity: A path analysis

Language teacher immunity, recently put forth by Hiver and Dornyei (2015), refers to “a robust armoring system that emerges in response to high-intensity threats and allows teachers to maintain professional equilibrium and instructional effectiveness” (Hiver, 2017, p. 669). Due to the pure novelty of this construct, its significance to the practice of teaching and rarity of research on it, the present study aimed to develop a model on the predictors of this newly-developed concept. Based on the theories in the related literature, a model was proposed in which four traits of six HEXACO personality traits, job insecurity, and reflective teaching were considered as predicting factors. Through running Path Analysis using AMOS with Maximum Likelihood Estimate on the quantitative data obtained from 483 English language teachers from Iran, a revised model was obtained in which agreeableness, extroversion and emotionality were proved to have effects on language teacher immunity indirectly through job insecurity and reflective teaching which had direct effects on it. The strongest paths were from Job Insecurity (JI) to Reflective Teaching (RT) and Language Teacher Immunity (LTI) with considerable negative regression weights meaning that JI can have negative effects on both of them. The findings of the current research provide implications for both teachers and teacher trainers, highlighting the predictors of teacher immunity

Prevalence of Seizure In PKU: An Analytic Historical Study

ObjectivePhenylketonuria (PKU) is an autosomal recessive metabolic genetic disorder characterized by a deficiency in the hepatic enzyme phenylalanine hydroxylase (PAH) which can cause problems with brain development, leading to progressive mental retardation, brain damage, and seizures. In this study we evaluated the frequency of seizure, EEG abnormality and behavioral disorders.Materials & Methods In this case study, 94 PKU children aged between 1 month and 23 years who were referred to Mofid children Hospital between 2009 and 2010 were enrolled.Patients were age and sex matched. Statistical tests were used for comparing patients' data.Results The mean age of patients was 8.4 years. Parents were relatives in 80.9% of the cases (76 patients). Of all, 43% (45 patients) had seizure but EEG was abnormal only in 81% of them (35 patients out of 43 patients). Totally, EEG was abnormal in 67% of the cases (63 patients) of whom 44.4% (28 patients of 63 patients) did not have seizure. Therefore, there was a significant relationship between seizure and EEG abnormality. The phenylalanine level ranged from 8mg/dL to 50mg/dL (mean: 18.88 mg/dL) at the time of diagnosis and from 0.4mg/dL to 18mg/dL (mean: 7.37mg/dL) at the time of evaluation. On the other hand,we observed abnormal behaviors in all EEG abnormalities and there was a significant relationship between EEG abnormality and behavioral disorders.ConclusionIn our study, the prevalence of seizure was less than EEG abnormality and there was a significant relationship between EEG abnormalities and behavioral disorders in patients with Phenylketonuria regardless of seizure.The authors believe that treatment of EEG abnormalities may lead to the correction of behavioral disorders in these patients.

Periodic Fever, Aphthous Stomatitis, Pharyngitis, and Cervical Adenitis (PFAPA) Misdiagnosed as Recurrent Urinary Tract Infection

Recurrent fever is common in children and specific infections account for the fever in most cases. PFAPA is not an uncommon cause of periodic fever during childhood. On the other hand, in patients with vesicoureteral reflux (VUR), urinary tract infection usually presents with fever.Here, we report two PFAPA cases in patients with VUR in whom recurrent episodes of fever were misdiagnosed as UTI. Keywords: PFAPA Syndrome; Periodic Fever Syndrome; Vesico-Ureteral Reflux; Urinary Tract Infections; Child

Effect of Duration and Frequency of Acoustic Doppler Velocimetry Measurement on Calculation of Turbulent Flow Characteristics

Acoustic Doppler velocimetry (ADV) is one of the most suitable devices for measuring flow characteristics. Determination of measurement frequency and duration, in a way that the results are calculated with the lowest error, is very important. The goal of this study was to determine the optimum measurement frequency and duration to save money and time. 3D instantaneous subcritical flocharacteristicsts are measured at 200, 100, 25, and 5Hz frequencies for a duration of 3 minutes, in a laboratory flume with an aspect ratio of less than 5. Then, 3D averaged velocities, shear velocity, turbulence intensity, and Reynolds shear stress are calculated. Results show that the reduction of error is independent of the number of measured data and its dependence is on the data collection duration and frequency. For measurements of 3D averaged velocity components, the appropriate measurement frequency and duration are 1Hz and 50 seconds, respectively. To determine the shear velocity, using logarithmic law, reducing the frequency and duration, results in a maximum error of 13%. For calculation of turbulence flow characteristics, like turbulence intensity and Reynolds shear stress, the measurement frequency, and duration of up to 25Hz and 50-70sec, respectively, results in an error of less than 10%

Progress in Reactors for High-Temperature Fischer-Tropsch Process: Determination Place of Intensifier Reactor Perspective

High-temperature Fischer-Tropsch (HTFT) process aims to produce lighter cuts such as gasoline and diesel. For many years there have been studies and improvements on HTFT process to make the existing reactors more efficient. Recent studies proposed new configurations such as dual-type membrane reactor and coupling configurations reactor, which improved the performances of this process. This achievement persuades us to update the existing knowledge about the available reactors for HTFT process. In this article, features and performances overview of two classes of reactors are reviewed. The first class consists of the reactors which are based on older studies, and the second one includes recent studies which are called product intensifier reactors. Finally, it is shown that the product intensifier reactors have higher CO conversions and lower selectivity of undesired by-products which results in higher production yield of gasoline. Furthermore, the place of product intensifier reactor among common reactors with regard to the influence of the process parameters on the product distribution has been estimate

Blockade of the Naloxone-induced Aversion in Morphine-conditioned Wistar Rats by L-Arginine Intra-central Amygdala

AbstractObjective(s)Single injection of naloxone, a selective antagonist of morphine, prior to the drug conditioning testing was used to investigate on morphine dependence.Materials and MethodsConditioning to morphine (2.5-10 mg/kg, s.c.) was established in adult male Wistar rats (weighing 200-250 g) using an unbiased procedure. Nitric oxide agents were microinjected into the central amygdala prior to naloxone-paired place conditioning testing.ResultsThe results showed that morphine produced a significant dose-dependent place preference in animals. Naloxone (0.1-0.4 mg/kg, i.p.) injections pre-testing of the response to morphine (7.5 mg/kg, s.c.) caused a significant aversion at the higher doses (0.4 mg/kg, i.p.). This response was reversed by microinjection of L-arginine (0.3-3 µg/rat, intra-central amygdala) prior to naloxone on the day of the testing. The response to L-arginine was blocked by pre-injection of NG-nitro-L-arginine methyl ester (L-NAME) (intra-central amygdala).ConclusionA single injection of naloxone on the test day of morphine place conditioning may simply reveal the occurrence of morphine dependence in rats, and that the nitric oxide in the central amygdala most likely plays a key role in this phenomenon

Risk assessment of occupational exposure to BTEX in the National Oil Distribution Company in Iran

BACKGROUND: This study evaluated the quantitative, carcinogenic and non-carcinogenic risk of exposure to BTEX using lifetime cancer risk (LCR) and hazard quotient (HQ) in the National Company for Distribution of Petroleum Products in Iran.METHODS: In this risk assessment method, the data were collected in different parts of the company. In order to determine the concentration of BTEX, sampling was carried out in different parts using activated carbon. A Gas Chromatography–Flame Ionization Detector (GC-FID) was used for analysis. Analysis and sampling was conducted according to the NIOSH 1500 method. For carcinogenic risk assessment, LCR was calculated. For non-carcinogenic risk assessment, HQ was calculated.RESULTS: The carcinogenetic risk of benzene was definite for loading and deep handling units, and safety officer, and was probable rank for sealing, inspection gate, security, loading 1, and deep handling units. The carcinogenic risk of ethylbenzene was definite for quality control and loading 1 units, was probable for deep handling and loading 2 units, and safety officer, and was possible for sealing, inspection gates, security units. The non-carcinogenic risk of toluene was acceptable for deep handling, clothing, inspection gates, and sealing units, but was unacceptable for officer safety, quality control, loading 1, and loading 2 units. The non-carcinogenic risk of xylene was acceptable for the inspection gate unit, but was unacceptable for security, sealing, officer safety, quality control, deep handling, loading 1, loading 2 units.CONCLUSIONS: This risk assessment method used was a comprehensive and quantitative method, so it determined risk accurately. Commensurate with the risk level of each part of the company, the appropriate corrective actions must be carried out

A New Method for Investigating Bioequivalence of Inhaled Formulations: A Pilot Study on Salbutamol

Purpose: An efficient, cost-effective and non-invasive test is required to overcome the challenges faced in the process of bioequivalence (BE) studies of various orally inhaled drug formulations. Two different types of pressurized meter dose inhalers (MDI-1 and MDI-2) were used in this study to test the practical applicability of a previously proposed hypothesis on the BE of inhaled salbutamol formulations. Methods: Salbutamol concentration profiles of the exhaled breath condensate (EBC) samples collected from volunteers receiving two inhaled formulations were compared employing BE criteria. In addition, the aerodynamic particle size distribution of the inhalers was determined by employing next generation impactor. Salbutamol concentrations in the samples were determined using liquid and gas chromatographic methods. Results: The MDI-1 inhaler induced slightly higher EBC concentrations of salbutamol when compared with MDI-2. The geometric MDI-2/MDI-1 mean ratios (confidence intervals) were 0.937 (0.721–1.22) for maximum concentration and 0.841 (0.592–1.20) for area under the EBC-time profile, indicating a lack of BE between the two formulations. In agreement with the in vivo data, the in vitro data indicated that the fine particle dose (FPD) of MDI-1 was slightly higher than that for the MDI-2 formulation. However, the FPD differences between the two formulations were not statistically significant. Conclusion: EBC data of the present work may be considered as a reliable source for assessment of the BE studies of orally inhaled drug formulations. However, more detailed investigations employing larger sample sizes and more formulations are required to provide more evidence for the proposed method of BE assay

Patency rate and factors affecting the clinical outcome of patients with aortoiliac artery occlusion undergoing intra-arterial stenting

Background Occluding plaques are commonly found inthe infrarenal aorta and the iliac artery in patients with peripheralarterial disease (PAD). Aortoiliacocclusive disease(AIOD) occurs commonly in patients with PAD.Methods: This is a prospective study was carried out between2015 and 2017 in Sina hospital. Patients with occlusionin aortoiliac artery and its branches were included.Stent was placed for patients, if they had any obstructionor stenosis in aortoiliac artery in angiography. Patientswere examined in terms of clinical status and ABI calculationand underwent Color Doppler ultrasound of aortoiliacartery to determine patency rate at 1, 3, 12, and 24months after stent placement.Results: The mean age of patients was 64.60 (±10.41).The main symptoms of the patients were claudication(41.8%), ulcer (27.3%), pain at rest (20%), and gangrene(20%). The lesion was bilateral in 21 patients (38.2%).According to TASC stratification, lesions were of type A in26 patients (47.3%), type B in 4 patients (7.3%), type Cin 5 patients (9.1%), and type D in 20 patients (36.4%).The six-month, one-year, and two-year patency rates were89.1%, 83.6%, and 72.7%, respectively. The mean annualABI of patients was 0.79 (±0.11) and two year ABIwas 0.68 (±0.1).Conclusion: It seems that stenting and angioplasty areeffective in improving patients’ conditions and result in agood short and medium-term patency