Assessing the Performance of Photocatalytic Oxidation of Volatile Organic Compounds in Three Different Scaled Set-ups

Volatile organic compounds (VOCs) are considered a major group of indoor air contaminants with several proven adverse health effects. Ultraviolet photocatalytic oxidation process (UVPCO) is a promising technology for the removal of VOC contaminants in indoor air environments. In addition, adequate efficiency of PCO has been proven in laboratory conditions. However, when PCO is scaled up and applied in real conditions, there are some limitations that need to be addressed. Several factors are involved in the efficiency of the PCO process such as humidity, flow rate (residence time), inlet of contaminant concentration, light source, etc. To the best of our knowledge, most of the research conducted in this area has been performed in a bench-scale reactor with long residence times of several minutes and at high VOCs concentrations (hundreds ppm level), which are far from being real indoor conditions. The main objective of this research is to study the scaling effect on isobutanol removal efficiency under the conditions relevant to real indoor applications. For this purpose, full-scale (0.6 m × 0.6 m), pilot-scale (four parallel ducts, 0.3 m × 0.3 m each) and bench-scale (9 cm × 7 cm) test set-ups were used to study the VOCs removal efficiencies via PCO in the gas phase. First, three experimental set-ups for testing TiO2 photocatalyst are described. Then, the isobutanol removal efficiency is evaluated in the condition, which is close to the real application, considering the low-level contaminant concentration and high flow rate. The relative humidity in this study is kept in the comfort zone (RH ~ 50±5 %). The performance of UVC-PCO of the three scales is compared and discussed. For isobutanol with 0.003 mg/m3 inlet contaminant concentration, around 24%, 56%, and 68% removal efficiencies were achieved in the full, pilot, and bench-scale systems, respectively

EEG Findings in Infants With Neonatal Abstinence Syndrome Presenting With Clinical Seizures

Neonatal abstinence syndrome (NAS) refers to a constellation of signs occurring in newborn infants who were exposed to opioids or opiates in utero. These manifestations include poor feeding, gastrointestinal disorders, abnormal sleep patterns, and neurological signs such as jitteriness, tremors, and seizures (1, 2). Myoclonus, jitteriness, and tremors often may be interpreted as seizures and therefore treated as epileptic seizures. Objective: To determine whether seizure like activity observed in infants with NAS correlate with electroencephalogram (EEG) findings. Design/ Method: We reviewed the standard EEG or video electroencephalogram (VEEG) of infants with NAS who were admitted because of seizure-like clinical activity. The exclusion criteria were major neurological anomalies, hypoxic ischemic encephalopathy, metabolic disorders, or with clinical diagnosis other than NAS. Results: Forty neonates met study criteria; 28 had standard EEG recordings and 18 had VEEG. Mean gestational age was 38.5 weeks. The onset of seizure-like clinical activity was as early as day 1 and as late as day 16 of life. The clinical seizure-like activity described at the referring hospital were jerking, rhythmic movement of the extremities, or tremors. Only three (7.5%) neonates had epileptic seizures. There were increased sharp transients in frontal, central, temporal, and or occipital regions. VEEG showed disturbed non-rapid eye movement (REM) sleep with frequent arousal, jittery movements, or sleep myoclonus. Conclusion: Clinical seizure-like activity correlates poorly with epileptic seizures in infants with NAS. In neonates with NAS, a VEEG would be useful to determine if the clinical seizure-like activity is of epileptic origin or not, prior to initiation of anti-seizure medications

TiO 2 photocatalyst for removal of volatile organic compounds in gas phase – A review

Heterogeneous photocatalytic oxidation process (PCO) is a promising technology for removing indoor volatile organic compounds (VOCs) contaminants. Titanium dioxide (TiO2) has been regarded as the most suitable photocatalyst for its cost effectiveness, high stability and great capability to degrade various VOCs. However, no TiO2-based photocatalysts completely satisfy all practical requirements given photoexcited charge carriers’ short lifetime and a wide band gap requiring ultraviolet (UV) radiation. Strategies for improving TiO2 photocatalyst activities by doping with different metal and/or non-metal ions and by coupling with other semiconductors have been examined and reported. These techniques can improve PCO performance through the following mechanisms: i) by introducing an electron capturing level in the band gap that would generate some defects in the TiO2 lattice and help capture charge carriers; ii) by slowing down the charge carrier recombination rate and increasing VOCs degradation. This paper reports the outcomes of a comprehensive literature review of TiO2 modification techniques that include approaches for overcoming the inherent TiO2 limitations and improving the photocatalytic degradation of VOCs. Accordingly, it focuses on the recent development of modified-TiO2 used for degrading gas phase pollutants in ambient conditions. Modification techniques, such as metal and non-metal doping, co-doping, and the heterojunction of TiO2 with other semiconductors, are reviewed. A brief introduction on the basics of photocatalysis and the effects of controlling parameters is presented, followed by a discussion about TiO2 photocatalyst modification for gas phase applications. The reported experimental results obtained with PCO for eliminating VOCs are also compiled and evaluated

Investigating Determinants of Banking Leverage in Selected Iranian Banks

The purpose of this study is to investigate the effect of intra-organizational and macro factors affecting banking leverage in selected Iranian banks in the presence of heterogeneous slope coefficients and cross-sectional dependence of residuals. For this purpose, the mean group estimators were used from 1999 to 2018 for selected 10 banks. Diagnostic tests showed that the hypotheses of cross-sectional dependence and heterogeneity of slope coefficients can not be rejected, so, the Augmented Mean Group estimator (AMG) was used. According to the results, the variables of credit risk and liquidity risk have positive and significant effects while the bank size has a negative and significant effect on bank leverage. Among macro and extra-organizational factors, inflation and real interest rates have positive effects and economic growth has a significant negative effect on the financial leverage of selected banks

Anthropometric, Body Composition, and Biochemical Measurements in Morbidly Obese Patients Prior to Bariatric Surgery

Background: Obesity is the most important risk factor for occurrence of chronic diseases. Morbid obesity could be accompanied by imbalance of body composition and serum levels of nutrients. Therefore, the aim of this study was to compare body composition and serum levels of nutrients in the bariatric surgery candidates with standard values.Methods: In this cross-sectional study, 100 morbid obese patients (22 men and 78 women) were enrolled. Their anthropometric and biochemical measurements were evaluated based on the standard protocols. Body composition was measured using the dual X-ray absorptiometry (DEXA) method. Independent t-test was used to compare the mean of quantitative variables between genders and measurements with the standard values to estimate any deficiency.Results: Grade 3 obesity (73%), abdominal obesity (100%), abnormal waistto-hip ratios (95%), abnormal body fat and fat-free mass percentages (100%), normal android-to-gynoid fat ratios (96%), and moderate body shape profiles (100%) were prevalent among the participants. Also, a deficiency of vitamin D (91%), vitamin B12 (19%), and iron (17% serum iron and 3% serum ferritin) was noticed. Serum levels of vitamin A (7%) and zinc (4%) were higher than normal among a part of population. There were no significant differences in the distributions of these indicators by gender.Conclusion: People with morbid obesity had abnormal amounts of fat and muscle tissue. Also, they were deficient regarding vitamin D, vitamin B12, and iron. Moreover, vitamin A and zinc levels in some people were higher than normal. Further studies are needed to confirm these findings in larger populations

EEG Findings in Infants With Neonatal Abstinence Syndrome Presenting With Clinical Seizures

Neonatal abstinence syndrome (NAS) refers to a constellation of signs occurring in newborn infants who were exposed to opioids or opiates in utero. These manifestations include poor feeding, gastrointestinal disorders, abnormal sleep patterns, and neurological signs such as jitteriness, tremors, and seizures (1, 2). Myoclonus, jitteriness, and tremors often may be interpreted as seizures and therefore treated as epileptic seizures.Objective: To determine whether seizure like activity observed in infants with NAS correlate with electroencephalogram (EEG) findings.Design/ Method: We reviewed the standard EEG or video electroencephalogram (VEEG) of infants with NAS who were admitted because of seizure-like clinical activity. The exclusion criteria were major neurological anomalies, hypoxic ischemic encephalopathy, metabolic disorders, or with clinical diagnosis other than NAS.Results: Forty neonates met study criteria; 28 had standard EEG recordings and 18 had VEEG. Mean gestational age was 38.5 weeks. The onset of seizure-like clinical activity was as early as day 1 and as late as day 16 of life. The clinical seizure-like activity described at the referring hospital were jerking, rhythmic movement of the extremities, or tremors. Only three (7.5%) neonates had epileptic seizures. There were increased sharp transients in frontal, central, temporal, and or occipital regions. VEEG showed disturbed non-rapid eye movement (REM) sleep with frequent arousal, jittery movements, or sleep myoclonus.Conclusion: Clinical seizure-like activity correlates poorly with epileptic seizures in infants with NAS. In neonates with NAS, a VEEG would be useful to determine if the clinical seizure-like activity is of epileptic origin or not, prior to initiation of anti-seizure medications

The Effect of Bariatric Surgery on Polycystic Ovary Syndrome (PCOS) Symptoms and Related Hormones Improvement in Women with Morbid Obesity

Background: Obesity is associated with developing polycystic ovary syndrome (PCOS). The present study investigated whether weight loss after bariatric surgery could improve symptoms and related hormones in women with morbid obesity.Methods: In a retrospective observational study, 50 women aged 18-40 years with body mass index (BMI)=42.3 kg/m2 who underwent laparoscopic Roux-en-Y gastric bypass (RYGB) were enrolled. Evaluation of anthropometric data, serum testosterone, luteinizing hormone (LH), follicle-stimulating hormone (FSH), prolactin (PRL), fasting plasmaglucose (FPG), and lipid profile were measured preoperatively and at 1-year follow-upResults: Of 50 women, 32 (64%) women were diagnosed to have PCOS. The mean BMI at 1-year follow-up was 27.05 kg/m2. Hirsutism and irregular menstruation resolved entirely among 68.8% (11/16) and 100% (18/18) at 1-year follow-up. There was a significant decrease in total serum testosterone (2.1±0.2 to 0.9±0.1 ng/mL) and LH (8.5±3.36 to 5.02±2.4 mIU/mL) at 1-year follow-up, whether changes in levels of serum FSH, PRL were not significant.Conclusion: Bariatric surgery was effective in weight loss and improvement of PCOS symptoms and related hormones in women with morbid obesity. Thus, women with PCOS and morbid obesity should be eligible for bariatric surgery

Photo-oxidation of Polypropylene Fiber and Effective Parameters: A Review

Production of polypropylene is growing for applications in different types of textiles. The main limitations in some of their applications are attributed to its low photostability and related property changes. There are several factors that have considerable effects on the process of photo-oxidation and the resulting photostability. From polymer production up to its usage the recognition of these parameters is necessary in order to control the degradation and to improve the useful life period of the products. In this paper, first the photo-oxidation mechanism of polypropylene in the presence of air is reviewed and then the effects of different factors including additives are examined. The incorporation of additives and light stabilizers in polymers are important in order to preserve their long-term use in the environment. Besides the complex mechanisms of photostabilization, this review presents an in-depth account of the behavior of the additives with respect to the photochemical oxidation of polypropylene and the interactions involved. Stabilization of polypropylene was improved in the presence of a mixture of photostabilizers, exhibiting an enhanced irradiation resistance. It would appear that the origin and composition of the pigment and its interaction with photostabilizers are all important factors. Several analytical techniques were employed to evaluate the stabilization effectiveness of the additives and degradation process; finally the techniques and the experimental methods for evaluation of photo-oxidation level and photo-oxidation products are introduced. Thedifferences in the views are highlighted and the shortcomings are explained

Laughter isn’t always the best medicine, sometimes it’s one of the symptoms

Gelastic seizure is a rare type of seizure characterized by bouts of uncontrolled, stereotyped laughter and often associated with hypothalamic hamartomas. In this case study we review a patient with a low grade ganglioglioma in the temporal lobe, a rare type of brain tumor that commonly causes seizures. The 8-year-old ambidextrous patient presented with seizures starting four days prior to presentation, happening multiple times daily and with each seizure lasting for 5–15 s. The patient’s neurological examination was normal between episodes, and VEEG recorded ictal laughing events originating focally from the anterior temporal and/or inferior frontal region. Seizures were stopped with Levetiracetam, however given MRI findings surgical intervention was additionally deemed necessary. MRI head with contrast showed 8 mm nodular enhancing lesion located in the anteroventral portion of the right temporal pole with surrounding edema that extended to the anterior margin of the fusiform gyrus. The patient recovered well from surgery with no neurological deficits, is no longer on any antiseizure medications and remains seizure free at 3-year follow-up

Study on Ablation Behavior of Phenolic Composites Prepared with Different Amounts of Zirconia and Asbestos Fiber

Ablative materials play a strategic role in aerospace industry. These materialsproduce a thermal protection system which protects the structure, theaerodynamic surfaces and the payload of vehicles and probes duringhypersonic flight through a planetary atmosphere. In this work, we investigated the effect of refractory zirconium oxide on mechanical, heat stability and ablation properties of asbestos/phenolic/zirconia composites. The asbestos/phenolic/zirconia composites were produced with different percentages of zirconia filler from 7 to 21% with average size of 7 μm and different number of layers of asbestos, say 3 to 6 layers. These ablative composites were made by an autoclave curing cycle process.The densities of the composites were in the range of 1.68 to 1.88 g/cm3. Ablation properties of composites were determined by oxy-acetylene torch environment and burn-through time, erosion rates and back surface temperature in the first required 20 seconds. Thermal stability of the produced materials was estimated by means of thermal gravimetric analysis, in both air and nitrogen which consisted of dynamic scans at a heating rate of 10°C/min from 30 to 1000°C with bulk samples of about 20±1 mg. The results showed that when the amount of zirconia was raised from 7% to 21%, the erosion rate and the back surface temperature of composites increased byabout 24% and 26% respectively, and the heat capacity of the composites increased by about 85%. Also, the result showed that when the thickness of composites of 4.2 mm was increased to 10.1mm the burn-through time raised by about 226% and erosion rate dropped by about 41%. These composites displayed the maximum flexural strength when the amount of zirconia was about 14%