Ionization In Diesel Combustion For On-Board Diagnostics And Engine Control

Diesel engines have been known for their high thermal efficiency and specific power output, but there is concern about engine-out NOx and particulate matter emissions. To meet the current emission standards, advanced diesel engines are fitted with electronically controlled fuel injection systems and sophisticated and expensive after-treatment devices. Further improvements are still needed to meet future goals in better fuel economy and the more stringent emission standards. In order to meet these goals, there is a need for the control of the combustion process to reduce engine-out emissions in real-time and reduce the demand on the after-treatment devices. This requires a signal indicative of the in-cylinder conditions to be fed in the ECU (Engine Control Unit). The most promising sensors in internal combustion engines are the cylinder gas pressure transducer and the combustion produced ion current sensor. Ion current probes have many advantages over pressure transducers because they are less expensive, more rugged, and are sensitive to the in cylinder gas temperature, and the composition of the combustion products. The ion current technique has been used in some SI engines, based on an understanding of the ionization produced from the combustion of a homogeneous charge. This is not the case in diesel engines where different types of flames are produced from the combustion of the heterogeneous mixture. This study investigates in details the characteristics of the ion current signal in diesel engines and its use for combustion diagnostics and feedback control of the engine. Experimental investigations and CFD simulation models are used to understand the characteristics of the ion current signal under different operating conditions. The investigations proved that the ion current signal carry basic information about combustion. 3-D mathematical models developed gave more insight into the distribution of the ionized species in the combustion chamber and enhanced the development of feedback control of the combustion process and enable the engine to autonomously operate properly on fuels of a wide range of physical and chemical properties. In addition, algorithms have been developed to use the signal for on-board diagnostics of different combustion, performance and engine-out emissions parameters

Updates in Thalassemia

Beta-thalassemia is a genetic disease caused by mutations in the β-globin gene, resulting in partial or complete deficiency of β-chain. Deficiency of β-chain was accompanied by excess unmatched α-globin chains with subsequent dyserythropoiesis, oxidative stress, and chronic anemia. The main therapeutic option is blood transfusion that improves the anemic status but unfortunately exacerbates iron overload status. Till now, the only curative measure is allo-hematopoietic stem cell transplantation. New diagnostic and therapeutic modalities are now available. These include the preimplantation genetic diagnosis and new tools in the assessment of iron overload. Also, new therapeutic options aimed at different targets are being developed; for example, therapies that stimulate the synthesis of γ-globin and reduce the synthesis of α-globin, as well as the iron excess, dyserythropoiesis, and oxidative stress. However, the most likely ideal approach is efficient prevention, through genetic counseling, carrier detection, and prenatal diagnosis

FACEBOOK AND ENGLISH LANGUAGE LEARNING: EFL LEARNERS’ EXPERIENCES (A QUALITATIVE STUDY)

The purpose of this quantitative study was to identify the EFL learners’ practices and understand their experiences with SNSs (social networking sites) as a tool for English language learning. The study results were obtained from a survey of 144 undergraduate Jordanian EFL learners in the English and Translation Departments at Yarmouk University in Jordan. In the quantitative phase of the study, the research questions focused on the actual practices and strategies of EFL students on SNSs. This study was guided by the following research questions: To what extent do Jordanian EFL learners use Facebook as a tool for language learning? And what language learning practices do Jordanian EFL learners engage in on Facebook? The results revealed that most participants felt comfortable using Facebook in English language learning. However, less than half of them used Facebook on a regular basis to learn English. In addition, they tended to read and observe discussions in English rather than participate in them or produce language output. The results also revealed that learners’ practices or behaviors in the SNS environment changed depending on certain factors, such as the context, audience, sense of belonging, self – confidence, and the learners’ needs and interests. The results of the study brought to light some implications in the context of formal and informal language learning. The study might raise learner, teacher, and educator awareness about SNSs as a tool for language learning, particularly for countries with limited resources. The results also showed the need for a theoretical and pedagogical framework for the teaching and learning process that identifies the best practices and ways to avoid any harm in a SNS environment. Integrating SNSs in language teaching and learning is a topic that requires further study. Using SNSs inside and outside the classroom to practice different language skills is an important topic for future research.  Article visualizations

SOCIAL NETWORKING SITES AND ENGLISH LANGUAGE LEARNING: JORDANIAN EFL LEARNERS’ PRACTICES AND EXPERIENCES

The purpose of this qualitative study was to identify the EFL learners’ practices and understand their experiences with SNSs (social networking sites) as a tool for English language learning. The study was conducted in richer information and a deeper insight was gained through a qualitative case study. In the qualitative phase, 12 participants were purposefully selected and interviewed in order to explain further the statistical results, develop a rich descriptive picture of their lived experiences using social networking to improve their English language learning, and identify the factors and barriers that influence their practices. This study was guided by the following research question: How do these Facebook practices affect their language learning experiences? The results revealed that most participants felt comfortable using Facebook in English language learning. However, less than half of them used Facebook on a regular basis to learn English. In addition, they tended to read and observe discussions in English rather than participate in them or produce language output. The results also revealed that learners’ practices or behaviors in the SNS environment changed depending on certain factors, such as the context, audience, sense of belonging, self – confidence, and the learners’ needs and interests.  Article visualizations

Effects of light intensity on Orthosiphon stamineus Benth. seedlings treated with different organic fertilizers.

The main objective of this study was to investigate the effects of varying light intensities and different organic fertilizers on the growth performance of O. stamineus seedlings through measurement of Relative Height Growth Rate (RHGR) and biomass production. Randomized Complete Block Design (RCBD) was used. Orthosiphon stamineus was arranged accordingly into three blocks or replicates. The three blocks represented the percentage light intensity. Block 1 (30% of light), Block 2 (50% of light) and Block 3 (100% of light). Each Block had four treatments and 25 plants of O. stamineus. The treatments were chicken dung, cow dung, oil palm empty fruit bunch (EFB) and control. The four treatments were arranged randomly in each block. Growth parameters measured were plant height, biomass (aerial portion, root biomass and total biomass within sixth month’s period. The 50% Relative Light Intensity (RLI) was better than 30 and 100% RLI. The chicken dung is better than oil palm EFB and cow dung

β-Thalassemia: Genotypes and Phenotypes

β-Thalassemias are extremely heterogeneous at the molecular level. More than 200 disease-causing mutations have been identified. The majority of mutations are single nucleotide substitutions. Rarely, β-thalassemia results from gross gene deletion. The degree of globin chain imbalance is determined by the nature of the mutation of the β-gene. β0 refers to the complete absence of production of β-globin on the affected allele. β+ refers to alleles with some residual production of β-globin (around 10%). In β++, the reduction in β-globin production is very mild. The broad spectrum of β-thalassemia alleles can produce a wide spectrum of different β-thalassemia phenotypes. In this chapter, we review the molecular basis of the marked heterogeneity of the thalassemia syndromes or in other words the genotype-phenotype relationship in β-thalassemia