Computer Simulation of Catalytic Oxidation of Gaseous Ammonia in Bubbling Fluidized Bed

Catalytic conversion of ammonia in bubbling fluidized bed has been simulated using three different hydrodynamic models: (a) Kunii and Levenspiel model, (b) Simple two-phase model, and (c) Dynamic two-phase model. The basic differences between the models lie in the assumptions and mass transfer correlations used to describe the hydrodynamics of the fluidized bed. This study compares the predictions of the performance of a fluidized bed reactor by different models, comparing with experimental data of ammonia oxidation using metal oxide catalysts. The predictions from all the models compared well with the experimental data within acceptable levels of error. The variations among the models were found to be insignificant. However, simulation of the model to assess the effect of different hydrodynamic parameters, including gas velocity, bed diameter and particle size, and bed density on conversion showed significant variation among the models

PRECAUTIONARY MEASURES IN OMANI PENAL LEGISLATION – THEORY AND PRACTICE

Punishment is considered a very old penal procedure and it is implemented widely across the globe. The modern theory in the studies of criminal penalty has changed due to the implementation of precautionary measures which plays an important part in the present criminal legislations, whether it is for the replacement of punishment or its implementation in case of loss of responsibility due to mental disease or minor age. This research discusses and explains the precautionary measures in the Omani legislation – theory and implementation through the identification of precautionary measures, its characteristics or features and conditions of implementation are discussed in the first part and in its second part, the situation of the Omani penal legislation towards the precautionary measures is discussed. Moreover, the research adobts the analysis methods by referring to the legal expression, analyzing it and finding its origin and legal content

Gasification conversion and char reactivity of rubber seed shell and high density polyethylene mixtures using steam Co-Gasification process

Due to the recent surge of global energy demand and the fear of climate change, an extensive attention from worldwide in seeking for cleaner alternative means of renewable energy and this has been a topic of interest widely. With the abundance supply of biomass and plastic waste generated annually and finding an effective method in utilizing these wastes, leads to a notion of using these wastes in the co-gasification process. Although there are studies on co-gasification of biomass and waste mixtures, limited studies focused on the understanding of the char reactivity and gasification conversion of this mixture. Hence, an experimental study on steam co-gasification of rubber seed shell and high density polyethylene mixtures in argon atmosphere is carried out using thermogravimetric (TGA) approach under non-isothermal condition. This work presents the surface physical morphology of rubber seed shell (RSS), high density polyethylene (HDPE), and its mixtures. Furthermore, the char conversion and char reactivity of RSS, HDPE, and their mixtures at different proportions are investigated in both pyrolysis and gasification process. The argon gas is supplied at a flowrate of 100 mL min-1and the steam is generated from superheater at 383 K whilst injected at flowrate of 3000 µL h-1into the TGA system

Performance Prediction of Waste Polyethylene Gasification Using CO2 in a Bubbling Fluidized Bed: A Modelling Study

Gasification of carbonaceous materials using CO2 from flue gases is an effective and economic means of waste recycling and environmental CO2 mitigation system. The paper presents investigation on conversion of plastics, such as (poly) ethylene, into valuable gaseous products, primarily Syngas or synthesis gas using CO2 as a gasifying agent instead of conventional steam. Typically, gasification is carried out in a fluidized bed reactor followed by sequential separation of syngas from tar and other undesired gaseous products. In this research work, the effect of operating conditions of the fluidized bed reactor on carbon conversion and H 2/CO mole ratio was examined. For this purpose, a process model of CO2 gasification of waste plastics using fluidized bed reactor was developed in ASPEN PLUS®. Sensitivity analysis concluded that parameters like CO2 – feed ratio, residence time, and gasification temperature serve to control the yield and quality of syngas. This work is licensed under a Creative Commons Attribution 4.0 International License

The Association Between Adverse Childhood Experiences (ACEs), Bullying Victimization, and Internalizing and Externalizing Problems Among Early Adolescents: Examining Cumulative and Interactive Associations

Both adverse childhood experiences (ACEs) and bullying victimization are linked with mental health problems in adolescents. However, little is known about the overlap between the two factors and how this impacts adolescent mental health problems (i.e., internalizing and externalizing problems). The current study analyzed data from 8,085 participants (47.7% female; 44.1% racial/ethnic minority) in the Adolescent Brain Cognitive Development (ABCD) study, baseline (2016–2018, ages 9–10 years) to Year 2. Regression analyses were used to estimate associations between ACEs, bullying victimization and mental health problems, respectively, adjusting for sex, race/ethnicity, country of birth, household income, parental education, and study site. The findings showed that both ACEs and bullying victimization were independently associated with higher internalizing and higher externalizing problems. However, no significant interaction was found between ACEs and bullying victimization. Overall, the results align with the cumulative risk model of adversity, linking cumulative ACEs and bullying victimization to internalizing and externalizing problems in early adolescents

Follow-up of CRT-D patients downgraded to CRT-P at the time of generator exchange

Background: Some patients with cardiac resynchronisation therapy (CRT) experience super-response (LVEF improvements to ≥50%). At generator exchange (GE), downgrading (DG) from CRT-defibrillator (CRT-D) to CRT-pacemaker (CRT-P) could be an option for these patients on primary prevention ICD indication and no required ICD therapies. Long-term data on arrhythmic events in super-responders is scarce. Methods: CRT-D patients with LVEF improvement to ≥50% at GE were identified in four large centres for retrospective analysis. Mortality, significant ventricular tachyarrhythmia and appropriate ICD-therapy were determined, and patient analysis was split into two groups (downgraded to CRT-P or not). Results: Sixty-six patients (53% male, 26% coronary artery disease) on primary prevention were followed for a median of 129 months [IQR: 101–155] after implantation. 27 (41%) patients were downgraded to CRT-P at GE after a median of 68 [IQR: 58–98] months (LVEF 54% ± 4%). The other 39 (59%) continued with CRT-D therapy (LVEF 52% ± 6%). No cardiac death or significant arrhythmia occurred in the CRT-P group (median follow-up (FU) 38 months [IQR: 29–53]). Three appropriate ICD-therapies occurred in the CRT-D group [median FU 70 months (IQR: 39–97)]. Annualized event-rates after DG/GE were 1.5%/year and 1.0%/year in the CRT-D group and the whole cohort, respectively. Conclusions: No significant tachyarrhythmia were detected in the patients downgraded to CRT-P during follow-up. However, three events were observed in the CRT-D group. Whilst downgrading CRT-D patients is an option, a small residual risk for arrhythmic events remains and decisions regarding downgrade should be made on a case-by-case basis.</p

A Student Team in a University of Michigan Biomedical Engineering Design Course Constructs a Microfluidic Bioreactor for Studies of Zebrafish Development

Abstract The zebrafish is a valuable model for teaching developmental, molecular, and cell biology; aquatic sciences; comparative anatomy; physiology; and genetics. Here we demonstrate that zebrafish provide an excellent model system to teach engineering principles. A seven-member undergraduate team in a biomedical engineering class designed, built, and tested a zebrafish microfluidic bioreactor applying microfluidics, an emerging engineering technology, to study zebrafish development. During the semester, students learned engineering and biology experimental design, chip microfabrication, mathematical modeling, zebrafish husbandry, principles of developmental biology, fluid dynamics, microscopy, and basic molecular biology theory and techniques. The team worked to maximize each person's contribution and presented weekly written and oral reports. Two postdoctoral fellows, a graduate student, and three faculty instructors coordinated and directed the team in an optimal blending of engineering, molecular, and developmental biology skill sets. The students presented two posters, including one at the Zebrafish meetings in Madison, Wisconsin (June 2008).Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/78149/1/zeb.2008.0572.pd

A cost effectiveness analysis of salt reduction policies to reduce coronary heart disease in four Eastern Mediterranean countries.

BACKGROUND: Coronary Heart Disease (CHD) is rising in middle income countries. Population based strategies to reduce specific CHD risk factors have an important role to play in reducing overall CHD mortality. Reducing dietary salt consumption is a potentially cost-effective way to reduce CHD events. This paper presents an economic evaluation of population based salt reduction policies in Tunisia, Syria, Palestine and Turkey. METHODS AND FINDINGS: Three policies to reduce dietary salt intake were evaluated: a health promotion campaign, labelling of food packaging and mandatory reformulation of salt content in processed food. These were evaluated separately and in combination. Estimates of the effectiveness of salt reduction on blood pressure were based on a literature review. The reduction in mortality was estimated using the IMPACT CHD model specific to that country. Cumulative population health effects were quantified as life years gained (LYG) over a 10 year time frame. The costs of each policy were estimated using evidence from comparable policies and expert opinion including public sector costs and costs to the food industry. Health care costs associated with CHDs were estimated using standardized unit costs. The total cost of implementing each policy was compared against the current baseline (no policy). All costs were calculated using 2010 PPP exchange rates. In all four countries most policies were cost saving compared with the baseline. The combination of all three policies (reducing salt consumption by 30%) resulted in estimated cost savings of $235,000,000 and 6455 LYG in Tunisia;$39,000,000 and 31674 LYG in Syria; $6,000,000 and 2682 LYG in Palestine and$1,3000,000,000 and 378439 LYG in Turkey. CONCLUSION: Decreasing dietary salt intake will reduce coronary heart disease deaths in the four countries. A comprehensive strategy of health education and food industry actions to label and reduce salt content would save both money and lives

Contrasting cardiovascular mortality trends in Eastern Mediterranean populations: contributions from risk factor changes and treatments

Background Middle income countries are facing an epidemic of non-communicable diseases, especially coronary heart disease (CHD). We used a validated CHD mortality model (IMPACT) to explain recent trends in Tunisia, Syria, the occupied Palestinian territory (oPt) and Turkey. Methods Data on populations, mortality, patient numbers, treatments and risk factor trends from national and local surveys in each country were collated over two time points (1995–97; 2006–09); integrated and analysed using the IMPACT model. Results Risk factor trends: Smoking prevalence was high in men, persisting in Syria but decreasing in Tunisia, oPt and Turkey. BMI rose by 1–2 kg/m2 and diabetes prevalence increased by 40%–50%. Mean systolic blood pressure and cholesterol levels increased in Tunisia and Syria. Mortality trends: Age-standardised CHD mortality rates rose by 20% in Tunisia and 62% in Syria. Much of this increase (79% and 72% respectively) was attributed to adverse trends in major risk factors, occurring despite some improvements in treatment uptake. CHD mortality rates fell by 17% in oPt and by 25% in Turkey, with risk factor changes accounting for around 46% and 30% of this reduction respectively. Increased uptake of community treatments (drug treatments for chronic angina, heart failure, hypertension and secondary prevention after a cardiac event) accounted for most of the remainder. Discussion CHD death rates are rising in Tunisia and Syria, whilst oPt and Turkey demonstrate clear falls, reflecting improvements in major risk factors with contributions from medical treatments. However, smoking prevalence remains very high in men; obesity and diabetes levels are rising dramatically