A computer model for heat exchange processes in mobile air-conditioning systems

The last few years have seen a rapid growth in the number of cars equipped with airconditioning systems. The space available to fit the system is limited and the under bonnet environment is hostile. Moreover, the depletion of the stratospheric ozone has led to legislation on the phasing out of the chlorofluorocarbons (CFCs) and hydrochlorofluorocarbons (HCFCs ). These substances are used as refrigerants in most refrigeration, heat pump and air-conditioning systems in service today. The aim of this research project was to study existing air-conditioning systems used in automotive applications to develop a model that simulates the components of these systems. This provides a better understanding of the effect of using different refrigerants in the system and its performance. Experimental studies of the performance of the different heat exchanger geometries used provided inputs to the model developed. Automotive air-conditioning condensers and evaporators simulation models were developed and used to compare the performance of these heat exchangers using CFC and HCFC refrigerants and the non-ozone depleting replacements. Thermodynamic properties of the new refrigerants were derived from the equation of state. The evaporator was simulated taking into consideration the mass transfe r associated with the heat transfer in humid conditions. Two types of compact heat exchangers were modelled, round tube with plane fin and plate tube with corrugated fin. These cover most automotive, domestic and industrial applications. The basic performance data of various geometries were determined experimentally. An existing thermal wind tunnel was re-instrumented and modified to improve accuracy at the low air velocities was used in this study. A new data logger linked to a personal computer was used with newly written software to collect and analyse the test data. The results for all geometries tested were correlated and presented in non-dimensional form. The test data were used to determine the effect of various geometrical parameters on the performance for an optimisation of condenser and evaporator designs. The model developed is being used by industrial collaborators for the design of heat exchangers in automotive air-conditioning systems

Investigating Successful Enterprise Resource Planning Implementation in Higher Education Institutions

This thesis investigates the successful implementation of Enterprise Resource Planning (ERP) in Higher Educational Institutions (HEIs). ERP is a business management system that has emerged to support organisations with a system of integrated applications to enhance their Information Technology (IT) infrastructures, enhance business processes and deliver a high quality of services. Research indicates limited success for implementing numerous ERP ventures and failure rates estimated between 60% and 90%. The failure of ERP implementation in higher education institutions (HEIs) worldwide is much higher in comparison to other sectors, such as banking or manufacturing, yet limited research has been conducted on this issue. There is a lack of sufficient knowledge, expertise and training to implement such sophisticated integrated systems and top management lacks the ability to take appropriate decisions for ERP implementation. However, merely focusing on several factors influencing ERP implementation may not suffice, as there is a need for a systematic decision-making process for adopting and implementing ERP systems in HEIs. The limited number of ERP applications being used in HEIs has resulted in inadequate research and many issues which require further exploration. Despite this, all the implications for successful implementation of ERP systems have yet to be assessed in HEIs, making it a relevant area for study and creating a need for a unique piece of research work. Thus, the researcher demonstrates that it is of high importance to investigate this area and contribute towards successful ERP implementations. The present study adopted an interpretivist research philosophy and the approach was inductive in nature. To collect the data from the selected case studies, a semi structured interview protocol was designed in accordance with the research objectives which was aimed at getting the views and opinions of both the higher management personnel as well as technical level staff from the selected sample of universities. The study was focused on the implementation of ERP systems for higher education institutions in Jordan. Jordan has the highest demand for higher education in the region and the number of enrolments is growing annually. The demand for ERP systems in Jordan is rising owing to the rapid growth of the Internet and mobile users and the increase in the literacy rate. The content analysis technique was used supported by NVivi11 software to process the data gathered from the sample. The key success factors identified from the participants were split into technical, organizational, project and project support categories. This research made several contributions to knowledge. These included 1) the identification and characterisation of three new sector and context-specific KSFs, namely: the selection of the right ERP system; the need for qualified IT staff for in-house maintenance and fair vendor relations. 2) The development of a framework for enhancing ERP implementation. 3) Evaluation measures of ERP performance from an organisational, technical, project, and project support system perspective. 4) Development of a synthesized model that contains mapped and prioritised KSFs on the ERP implementation lifecycle based on their importance for successful implementation. In addition to these reflected theoretical contributions, this research also highlights the implications on the practices of higher education institutes, particularly for, but not limited to, Jordanian HEIs. The research findings provide an insight into the KSFs that are important for the successful implementation of ERP systems, identifying two new implementation lifecycle stages, the influential factors being mapped across the lifecycle phases providing a more detailed and in-depth understanding of what is required

“The Single Thin Ray That Fell upon the Vulture Eye”: Systemic Grammar and Its Use in Edgar A. Poe’s “The Tell-Tale Heart”

This paper argues that Edgar Allan Poe applies many linguistic techniques in his short story “The Tell-Tale Heart” in order to express the dilemma of a character caught up in the trap of a confused identity, lost subjectivity, and uncontrolled performances. Poe’s story is analyzed in detail to examine the psychology of the performed actions. We analyze some aspects of clause construction, paying attention to ‘who is doing what to whom.’ This analysis is twofold: defining clause construction and discussing why this analysis is relevant and why Poe’s story was chosen for this kind of analysis. In addition, we prove through the grammatical and linguistic choices made by Poe the madness and the instability of the main character in the story. We will be selective in choosing the lines to be discussed, as we focus on the lines that show the main character’s detachment from himself and the rational world he belongs to. The language Poe uses in describing the mad act of killing the old man is highly committed to the psychology and ideology of the text along with its complexities in defining why a man would do what the narrator did

Towards Sustainable Wastewater Reuse in the Middle East and North Africa

Water has a precious value, and each drop must be accounted for in water scarce regions such as the Middle East and North Africa. Therefore, wastewater has to be reclassified as a renewable water resource rather than as waste. This helps in augmenting water availability, and at the same time in preventing environmental pollution. Utilization of this resource requires collection, treatment, and use of all generated wastewater. Although reuse of wastewater is recognized in most water-scarce countries, the reuse of wastewater is still very low. This paper analyzes the major components of a sustainable wastewater reuse scheme. It also reviews the different methods that are frequently used to quantify and report progress and achievements in wastewater reuse. The paper also introduces an alternative yardstick named by the author as the Wastewater Reuse Index (WRI) that has a value between 0-100; WRI is calculated by dividing the amounts of wastewater being actually reused by the total amounts of wastewater generated at country level. WRI enables water resource managers and policymakers to put a figure on the gap between achievements at different junctures. Moreover, WRI recognizes water saving efforts such as low water consumption and reducing losses; thus, WRI highlights the way forward for improving the reuse efficiency as an integral part of water resources management. The paper highlights the major barriers to extensive reuse of the reclaimed wastewater in the MNEA countries

Effect of land-use/land-cover change on the future of rainfed agriculture in the Jenin Governorate, Palestine

An article in International Journal of Global Environmental, Vol. 16, Nos. 1/2/3, 2017Land cover has been changed by humans throughout history. At the global level, population growth and socio-economic development have a significant impact on land resources. Recently, scholars added climate change as one of the major factors affecting land-cover transformation. In the West Bank of Palestine, the situation is more complicated, where geopolitical constraints due to the Israeli occupation and lack of control over land resources. In the West Bank, fertile land represents 16%, 87% of the cultivated land is rainfed, 11% is pastureland and 2% is irrigated. This paper focuses on the problems of agricultural land shrinkage by time and tries to reveal the major factors behind this change. The study area is Jenin, a major agricultural area in the West Bank, Palestine. Statistical data, aerial photos and related attribute data were analyzed by using GIS software. The study showed that urban growth is the major threat on agricultural lands

Fuzzy TOPSIS method in the selection of Investment Boards by incorporating operational risks

Multi Criteria Decision Making (MCDM) involves not only attributes that are precise or crisp, but also values that are not deterministic. Currently, Fuzzy TOPSIS presents a solution for decision makers when dealing with real world data that are usually multi attributes and involves a complex decision making process. In this work, an application of this method is demonstrated in the selection of Investment Boards by taking into account the operational risks involved

Feline patent Toxoplasma-like coccidiosis among feral cats (Felis catus) in Doha city, Qatar and its immediate surroundings

Doha city has a high feral cat population and studies of hospital records in Doha have shown that human toxoplasmosis also occurs. Clearly, there is a need to understand the role of cats as vectors of human toxoplasmosis in the city and as a first step we assessed the extent of patent Toxoplasma-like coccidial infections among feral cats. Oocysts in cat faeces were detected between June 2008 and April 2010, from a range of locations radiating out of the city centre in concentric semi circular/elliptic rings and by north, west and south divisions within each of the rings. In total 4,652 cats were sampled and overall prevalence of oocysts was 9.1%. Prevalence was 10.1% in the first summer, and then dropped to 8.4% in the following winter and further to 6.8% in the next summer before rising to 10.6% in the final winter of the study; this interaction between annual period and season was significant. There were also significant changes in prevalence across each of the consecutive months of the study, but no clear pattern was evident. Prevalence did not vary significantly by city sector and there was no difference in prevalence between the host sexes. We conclude therefore, that despite minor and significant perturbations, the prevalence of patent Toxoplasma-like coccidial infections among cats in Doha is remarkably stable throughout the year, across years and spatially within the city’s districts.Qatar National Research Funds Student grant UREP 05 – 060 – 3 – 01

Seroprevalence of Toxoplasma gondii infection in feral cats in Qatar

Background: Cats are essential in the life cycle of Toxoplasma gondii as they can shed the environmentally resistant oocysts after acquiring infection. Human populations living in cities with high densities of feral cats are therefore likely to be at risk of infection. The current study is the first to estimate the seroprevalence of T. gondii in the feral cat population in Qatar. We investigated the seroprevalence of T. gondii among 495 adult cats from urban and suburban districts in Qatar. Using results from the Modified Agglutination Test, we fitted statistical models with host sex, area and season as explanatory factors and seropositivity as the outcome. Results: The analysis revealed an overall seroprevalence of 82%. Seroprevalence was significantly higher in the summer season (P = 0.006). No significant difference was detected (P > 0.05) between seroprevalence in female and male cats and in cats from urban and suburban districts of Qatar. Conclusions: Despite the seasonal difference, the observed seroprevalence of T. gondii suggests high environmental contamination throughout the year, with some female cats generating more intense responses compared to males. Both findings merit further investigations.NPRP grant number NPRP 4-164-4-001 from Qatar National Research Fun

Intestinal Parasitic Infections among Long-Term-Residents and Settled Immigrants in Qatar in the Period 2005 to 2011

Abstract. The expanding economy of Qatar in the last two decades has attracted immigrants, often from countries with poor socio-economic levels. Many arrive with patent intestinal parasitic infections, and recent analyses have indicated consistently rising trends in the prevalence of some infections. Here, we examined 18,563 hospital records of subjects in Qatar seeking medical assistance for a variety of ailments, combining data from 2009 to 2011 with the earlier dataset from 2005 to 2008 to enable trends to be identified across a 7-year period. We found that 8.6% were infected with one or more species of parasites, however in contrast to the earlier period (2005–2008), in the latter 3 years there were falling trends of prevalence providing some optimism that parasitic infections among the resident immigrants have begun to decline. We identified also geographic regions from which resident workers still maintain a relatively high prevalence of helminth infections despite their long-term residence in Qatar.This publication was made possible by a grant from Qatar National Research Fund (QRNF) at Qatar Foundation through National Priorities Research Program (NPRP) (Project No. NPRP 4-1283-3-327

Seroprevalence and epidemiological correlates of Toxoplasma gondii infections among patients referred for hospital-based serological testing in Doha, Qatar

Background. The city of Doha in Qatar has a high density of feral cats and there is a high risk of toxoplasmosis for the resident human population. No data currently exist for the prevalence of infection with Toxoplasma gondii in the city. Methods. We analysed the serological response to Toxoplasma gondii of 1625 subjects referred for routine hospital based serological tests in Doha, Qatar. Prevalence of current/recent infection was assessed through an enzyme-linked immunosorbent assay (ELISA) for the presence of specific anti-T. gondii IgM antibodies, and previous history of infection through IgG. Results. Overall prevalence of IgG responses was 29.8% and this did not differ between the sexes nor between the three years of the study although there was a marked age effect. Among children less than 1 year old prevalence was 22.9%, but then dropped to 45 years). The prevalence of IgG antibody also varied significantly with region of origin, with higher rates for subjects from Africa, followed by those from the Eastern Mediterranean or Asia and lowest rates for subjects from the Arabian Peninsula. No IgM antibodies were detected in any subjects younger than 19 years, but prevalence increased to plateau at 7 - 9% in subjects aged over 20 years, and also varied with region of origin. In this case prevalence was highest among subjects from the Arabian Peninsula and least among those from Asia. Prevalence of IgM was higher among male subjects but did not vary between the three years of the study. Conclusion. Although these data are based on a selected subset of the population, they nevertheless provide the first evidence that toxoplasmosis is endemic in Qatar in the human population, and that both age and region of origin play a role in the epidemiology of the infection. Concerns relating to the role of high density of feral cats in sustaining the infection were highlighted