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Search Results: 1 - 10 of 32268 matches for " Peter Fsadni "
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The Impact of Microbiological Pollutants on School Indoor Air Quality  [PDF]
Peter Fsadni, Bezzina Frank, Claudia Fsadni, Stephen Montefort
Journal of Geoscience and Environment Protection (GEP) , 2017, DOI: 10.4236/gep.2017.55004
Abstract: Asthma is common in children with allergens and mould influencing the development of the disease. Since children spend most of their time outside their homes within the school environment, school indoor air quality can directly influence their respiratory health. This study aims to identify microbiological contaminants in Maltese schools. The association between contaminants, respiratory health and school characteristics has been analysed. Five primary schools were selected with 9 to 11 years old students participating. Standardised health questionnaires, lung function tests, and school characterisation were performed. Dust samples were analysed for fungi, bacteria and allergens were performed. Penicillium/Aspergillus/Paecilomyces/Variotii (PenAsp) group had the highest median indoor concentration followed by Mycobacterial and Streptomyces species. There was a significant negative correlation between PenAsp and Mycobacterium spp levels in all the participating schools (r = ?0.42; p = 0.03). Cat allergen in classroom dust correlated positively with the number of cat owners (r = 0.43; p = 0.041). High exposure to fungi, bacteria and allergens was significantly associated with upper and lower airway atopy. School/classroom characteristics and cleaning protocols were significantly associated with exposure to these pollutants. In conclusion, fungi, bacteria, endotoxin, cat and dog allergens have been found to have a direct influence on school indoor air quality in the Maltese Islands. A significant association was observed between these contaminants and upper and lower airway atopy. Specific school, classroom, cleaning and maintenance characteristics have been identified as having a direct impact on indoor air quality.
Micro bubble formation and bubble dissolution in domestic wet central heating systems
Fsadni Andrew M.,Ge Yunting
EPJ Web of Conferences , 2012, DOI: 10.1051/epjconf/20122501016
Abstract: 16 % of the carbon dioxide emissions in the UK are known to originate from wet domestic central heating systems. Contemporary systems make use of very efficient boilers known as condensing boilers that could result in efficiencies in the 90-100% range. However, research and development into the phenomenon of micro bubbles in such systems has been practically non-existent. In fact, such systems normally incorporate a passive deaerator that is installed as a ‘default’ feature with no real knowledge as to the micro bubble characteristics and their effect on such systems. High saturation ratios are known to occur due to the widespread use of untreated tap water in such systems and due to the inevitable leakage of air into the closed loop circulation system during the daily thermal cycling. The high temperatures at the boiler wall result in super saturation conditions which consequently lead to micro bubble nucleation and detachment, leading to bubbly two phase flow. Experiments have been done on a test rig incorporating a typical 19 kW domestic gas fired boiler to determine the expected saturation ratios and bubble production and dissolution rates in such systems.
Two-phase distribution in the vertical flow line of a domestic wet central heating system
Fsadni A.-M.,Ge Y.T.
EPJ Web of Conferences , 2013, DOI: 10.1051/epjconf/20134501030
Abstract: The theoretical and experimental aspects of bubble distribution in bubbly two-phase flow are reviewed in the context of the micro bubbles present in a domestic gas fired wet central heating system. The latter systems are mostly operated through the circulation of heated standard tap water through a closed loop circuit which often results in water supersaturated with dissolved air. This leads to micro bubble nucleation at the primary heat exchanger wall, followed by detachment along the flow. Consequently, a bubbly two-phase flow characterises the flow line of such systems. The two-phase distribution across the vertical and horizontal pipes was measured through a consideration of the volumetric void fraction, quantified through photographic techniques. The bubble distribution in the vertical pipe in down flow conditions was measured to be quasi homogenous across the pipe section with a negligible reduction in the void fraction at close proximity to the pipe wall. Such a reduction was more evident at lower bulk fluid velocities.
Natural Rights, Morality, and the Law  [PDF]
Drum Peter
Beijing Law Review (BLR) , 2011, DOI: 10.4236/blr.2011.21004
Abstract: It is argued that despite attempts to discount the importance of natural rights for morality, they are fundamental to it; therefore, so too are natural rights to the legitimacy of the law.
Price Stability and the Growth Maximizing Rate of Inflation for Ghana  [PDF]
Peter Quartey
Modern Economy (ME) , 2010, DOI: 10.4236/me.2010.13021
Abstract: Monetary policy in Ghana, which is typical of many central banks, over the years, has focused on ensuring price stability or low inflation. The aim of the policy of price stability is to provide a stable environment for real sector activities to flourish. However, the outcome of the policy on real sector activities has not been subjected to any empirical investigation and this forms the focus of the study. For instance, the Central Bank has focused on single digit inflation and whether such a low rate is growth maximizing is yet to be ascertained. The study therefore investigates the revenue maximizing and the ‘growth maximizing’ rate of inflation for Ghana using data from Bank of Ghana and WDI. The study finds that economic performance is higher under low inflation era than when inflation is high. It also established the revenue maximizing rate of inflation using the Laffer curve approach is lower than the growth maximizing rate of inflation. Also, from the results, it can be deduced that the single digit inflation target set by the Central bank is not growth maximizing.
Aristotle’s Definition of Place and of Matter  [PDF]
Peter Drum
Open Journal of Philosophy (OJPP) , 2011, DOI: 10.4236/ojpp.2011.11006
Abstract: The accuracy of Aristotle’s definition of place is defended in terms of his form-matter theory. This theory is in turn defended against the objectionable notion that it entails matter is ultimately characterless.
Adapted Caussinus-Mestre Algorithm for Networks of Temperature series (ACMANT)  [PDF]
Peter Domonkos
International Journal of Geosciences (IJG) , 2011, DOI: 10.4236/ijg.2011.23032
Abstract: Any change in technical or environmental conditions of observations may result in bias from the precise values of observed climatic variables. The common name of these biases is inhomogeneity (IH). IHs usually appear in a form of sudden shift or gradual trends in the time series of any variable, and the timing of the shift indicates the date of change in the conditions of observation. The seasonal cycle of radiation intensity often causes marked seasonal cycle in the IHs of observed temperature time series, since a substantial portion of them has direct or indirect connection to radiation changes in the micro-environment of the thermometer. Therefore the magnitudes of temperature IHs tend to be larger in summer than in winter. A new homogenisation method (ACMANT) has recently been developed which treats in a special way the seasonal changes of IH-sizes in temperature time series. The ACMANT is a further development of the Caussinus-Mestre method, that is one of the most effective tool among the known homogenising methods. The ACMANT applies a bivariate test for searching the timings of IHs, the two variables are the annual mean temperature and the amplitude of seasonal temperature-cycle. The ACMANT contains several further innovations whose efficiencies are tested with the benchmark of the COST ES0601 project. The paper describes the properties and the operation of ACMANT and presents some verification results. The results show that the ACMANT has outstandingly high performance. The ACMANT is a recommended method for homogenising networks of monthly temperature time series that observed in mid- or high geographical latitudes, because the harmonic seasonal cycle of IH-size is valid for these time series only.
Random but System-Wide Unique Unlinkable Parameters  [PDF]
Peter Schartner
Journal of Information Security (JIS) , 2012, DOI: 10.4236/jis.2012.31001
Abstract: When initializing cryptographic systems or running cryptographic protocols, the randomness of critical parameters, like keys or key components, is one of the most crucial aspects. But, randomly chosen parameters come with the intrinsic chance of duplicates, which finally may cause cryptographic systems including RSA, ElGamal and Zero-Knowledge proofs to become insecure. When concerning digital identifiers, we need uniqueness in order to correctly identify a specific action or object. Unfortunately we also need randomness here. Without randomness, actions become linkable to each other or to their initiator’s digital identity. So ideally the employed (cryptographic) parameters should fulfill two potentially conflicting requirements simultaneously: randomness and uniqueness. This article proposes an efficient mechanism to provide both attributes at the same time without highly constraining the first one and never violating the second one. After defining five requirements on random number generators and discussing related work, we will describe the core concept of the generation mechanism. Subsequently we will prove the postulated properties (security, randomness, uniqueness, efficiency and privacy protection) and present some application scenarios including system-wide unique parameters, cryptographic keys and components, identifiers and digital pseudonyms.
Enlarged cauda equina nerve roots in Cerebrotendinous Xanthomatosis  [PDF]
Peter Kalina
Open Journal of Clinical Diagnostics (OJCD) , 2011, DOI: 10.4236/ojcd.2011.13006
Abstract: CXT is a rare inherited autosomal recessive lipid storage disease due to the impaired metabolic pathway of cholesterol secondary to a deficiency in 27- sterol hydroxylase, an enzyme in the synthesis of chenodeoxycholic acid (CDCA), a primary bile acid. Abnormal bile acid synthesis leads to elevated plasma Cholestanol (a derivative of cholesterol) accumulation, especially in the lens, central nervous system (CNS) and tendons.
Spinal Cord Compression by Thoracic Vertebral Hemangioma—A Case Report  [PDF]
Peter Kalina
Open Journal of Medical Imaging (OJMI) , 2012, DOI: 10.4236/ojmi.2012.21005
Abstract: A 68 year old with lower extremity numbness, vibratory sensation loss, coldness and burning of his feet, unsteady gait, frequent falls and a sensory level had an MRI demonstrating aT7 and T8 vertebral body/posterior element lesion with epidural extension, cord compression and foraminal extension (Figures 1-5). Decompressive laminectomy/resection confirmed vertebral hemangioma, a common benign neoplasm that typically remains asymptomatic, found incidentally in 10% of the population. Progressive vertebral body hemangiomas may cause cord or nerve root compression due to epidural tumor extension, expanded bone, hematoma or fracture. Radiographs demonstrate course vertical striations caused by thick trabeculae. CT in indolent lesions demonstrates fat density while compressive lesions demonstrate soft tissue density. Indolent lesions follow fat signal on MRI; symptomatic lesions are T1 isointense/T2 hyperintense. Work-up for aggressive hemangiomas includes angiography to determine vascularity, identify feeding/draining vessels and identify blood supply to the cord. Biopsy helps differentiate hemangioma, lymphoma, myeloma or metastasis. Management of symptomatic hemangiomas includes vertebroplasty for pain, radiation for pain, compression or pre-op and decompressive laminectomy for epidural disease. Embolization of feeding vessels may be performed pre-op or may be curative. Hemangioma causing cord compression and neurologic symptoms by extraosseous extension is much less common than benign hemangioma. Imaging features may suggest potential for progression.
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