Modelling of liquid-liquid dispersions in batch stirred vessels

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Selective Photodegradation Using Titanate Nanostructures

Adsorption and photocatalytic degradation are considered as the most important ways of treating water from organic compounds. It would be very useful if the adsorption and photocatalytic properties are combined in the same catalyst used in the treatment. Titania is one of the best well-known photocatalysts. However, due to its poor selectivity, it is unfavorable for photocatalytic removal of highly toxic low-level organic pollutants in wastewater in the presence of other less toxic high-level pollutants. Recent trials to introduce selectivity for titania have been achieved via controlling the catalyst morphology or by modifying the catalyst surface. This chapter summarizes the control of selectivity of titanate nanostructures toward adsorption and/or photocatalytic degradation of toxic organic dyes. In the first part, the effect of morphologies of titanites on selective photocatalytic degradation of three food dyes (color yellow sunset, red allura, and red carmoisine) was discussed. In changing the morphology of titanite, each dye is being preferably adsorbed by one morphology and decomposing more rapidly. In the second part, the selective adsorption and/or photocatalytic degradation of methylene blue dye from mixed dye solution using sodium titanate (NaTNT), cobalt-doped titanate nanotubes (co-doped TNT), and the decorated one with gold nanoparticles has been discussed

Mechanical pretreatment of waste paper for biogas production

In the anaerobic digestion of lignocellulosic materials such as waste paper, the accessibility of microorganisms to the fermentable sugars is restricted by their complex structure. A mechanical pretreatment with a Hollander beater was assessed in order to reduce the biomass particle size and to increase the feedstock’ specific surface area available to the microorganisms, and therefore improve the biogas yield. Pretreatment of paper waste for 60 min improves the methane yield by 21%, from a value of 210 ml/gVS corresponding to untreated paper waste to 254 ml/gVS. 30 min pretreatment have no significant effect on the methane yield. A response surface methodology was used to evaluate the effect of the beating time and feedstock/inoculum ratio on the methane yield. An optimum methane yield of 253 ml/gVS was achieved at 55 min of beating pretreatment and a F/I ratio of 0.3

Prospects and challenges of concentrated solar photovoltaics and enhanced geothermal energy technologies

Reducing the total emissions of energy generation systems is a pragmatic approach for limiting the environmental pollution and associated climate change problems. Socio economic activities in the 21st century is highly determined by the energy generation mediums, particularly the renewable resources, across the world. Therefore, a thorough investigation into the technologies used in harnessing these energy generation mediums should contribute to their further advancement. Concentrated Solar Photovoltaics (CSP) and Enhanced Geothermal Energy (EGE) are considered as emerging renewable energy technologies with high potential to be used as suitable replacements for fossil products (petroleum, coal, natural gas etc.). Despite the accelerated developments in these technologies, they are still facing many challenges in terms of cost. This review paper presents a detailed background about these renewable energy technologies and their main types such as solar tower, parabolic trough, and so on. Also, the principle challenges impeding the advancement of these energy technologies into commercialisation are discussed. Possible solutions for the main challenges are presented and the future prospects for such energy generation mediums are reported

Effects of mixed nitrogen sources on biodegradation of phenol by immobilized Acinetobacter sp. strain W-17

Using Ca-alginate immobilized cells of Acinetobacter sp. strain W-17, the effects of ammonium-N and nitrate-N on the biodegradation of phenol were investigated. Degradation experiments in three different culture media; minimal salts medium (MSM), simulated (SW) and modified simulated wastewater (MSW) were performed. With the freely suspended cells (cell dry weight 0.2 g/l), complete phenol (500 mg/l) degradation was achieved after incubation for 120 h. Using the immobilized cells, the time was reduced to 24 h in MSM medium, and 15 h in the MSW. The results also indicate that strain W-17 can tolerate to high concentrations of NH4+-N (63 mg/l) and NO3--N (1000 mg/l) without a significant loss in the phenol biodegradation rate. Moreover, the presence of 500 mg/l phenol in the MSW had no considerable effect on the removal of both ammonium-N and nitrate-N. Repeated use of immobilized cells revealed that they could be used as much as five times without loss of activity. Our findings could be extended to enhance biotreatment of phenol contamination in a variety of biological treatment processes. (African Journal of Biotechnology: 2003 2(1): 8-12

Impulsivity, Depression and Aggression among Psychiatric Patients

Aggression in inpatient facilities can generally be conceptualized as an interaction between an individual and the environment in which he or she finds themselves. The aim of this study was to assess impulsivity, depression and aggression among psychiatric patients. Descriptive correlational research design was used in this study. A convenient sample of 100 psychiatric patients from Beni-Ahmad psychiatric hospital in El-Minia, governorate, four tools were utilized to measure the study variables; Personal and clinical data Questionnaires, Barratt Impulsiveness Scale, Beck Depression Inventory and Aggression Questionnaire. Results of the study revealed that, 79% of the patients were in the age group from 20-35 years, 63% of the patients were males, and 52% of the patients were not working, 42% of the patients were schizophrenic, 56% of patients had moderate impulsivity, 58% of patients had extreme level of depression and 51% of the patients had severe level of aggression. In conclusion, more than half of psychiatric patients had moderate impulsivity level, extreme level of depression and severe level of aggression. There were positive correlations between impulsivity, depression and aggression. This study recommended developing and implementing psychosocial program to decrease impulsivity, depression and aggression among the psychiatric patients. Keywords: Impulsivity/ Depression /Aggression / psychiatric patients

Conventional and molecular differentiation between capsular types of Pasteurella multocida isolated from various animal hosts

In this study, ten strains of P. multocida isolated from chicken, cattle, buffalo and sheep had a clinical manifestation of pneumonia were identified by species-specific PCR (PM-PCR) and 460bp products were obtained. Capsular typing of P. multocida is useful for epidemiological evidence and has been assessed by conventional and genotyping assays. According to the results, only one out of the ten strains (10%) which isolated from chicken was detected as capsular type D based on acriflavine test and did not detect the capsular type A for all the ten strains (0%) by using hyaluronidase test. PCR was applied to identify the capsular types using specific primers for each type of P. multocida. The findings of this study showed that a uniform amplicon size was corresponding to 657bp, 851bp and 510bp indicating that it belongs to capsular type D, type F and type E, respectively. So, the ten strains were identified to a one strain isolated from chicken as a type D (10%), one strain of which isolated from cattle as a type F (10%) and eight strains of which isolated from sheep, cattle, buffalo and chicken as a type E (80%). Likewise, the data of multiplex PCR showed that capsular type D, one strain; capsular type F, one strain and capsular type E, eight strains. Thus, the multiplex PCR can be used as a simple, sensitive, rapid, reliable technique for capsular typing identification of P. multocida. We concluded that the P. multocida serogroup E is common in Egypt and has a wide host range