386 research outputs found
On the generalized Hartley-Hilbert and Fourier-Hilbert transforms
In this paper, we discuss Hartley-Hilbert and Fourier-Hilbert transforms on a certain class of generalized functions. The extended transforms considered in this article are shown to be well-defined, one-to-one, linear and continuous mappings with respect to δ and Δ convergence. Certain theorems are also established
Geological Alterations and Chemical Treatment of a Polluted Limestone Foundation
A large factory for the production of concentrated sulphuric acid is constructed in 1977 and located in the west of Iraq near Al-Kaim city. The footings carrying the installations rest on calcareous rocks which extend deep into the ground. For many years, about 1.5 tons per day of acid seeped and percolated into the ground apart from frequent accidents when larger amounts took their path down into the ground. A record of the footings movement revealed that the footings experienced significant heave and settlement indicating a cyclic movement which depends on the frequency of seepage. The results of the past geotechnical and geochemical investigations have been carefully studied in order to trace the geological alterations occurring in the ground due to the percolation of sulphuric acid over years. It appeared that at certain depths the limestone rock has been almost converted to dough and that a significant amount of dolomitization has taken place in the factory ground. Contaminated samples have been obtained from boreholes executed in the factory site. Many chemical materials have been chosen to treat the contaminated samples. Among these materials are sodium silicate, sodium carbonate, sodium silicate plus calcium chloride, barium sulfate, aluminum oxide, ferric oxide and bentonite. Unconfined compression, ultrasonic wave, physical, wet chemical and XRD tests were performed on intact, contaminated and treated specimens. The results proved that sodium silicate is the best alternative to be used for chemical grouting of the ground. The use of calcium chloride with sodium silicate did not show an additional advantage. Samples contaminated to the degree of having the form of dough have almost regained their original solid state strength when treated with sodium silicate
Modeling Through Traffic Speed at Roundabouts Along Urban and Suburban Street Arterials
A total of 30 roundabouts with different dimensions and characteristics were selected from three cities in Jordan. The collected data included the approaching road free flow speed (FFS), area type, entry width, circulating roadway width, exit width, roundabout internal and external circle diameters, circulating roadway super elevation, entry deviation angle, and drive curve. The regression analysis showed that the entry width, internal circulating diameter, entry deviation angle, approaching FFS, and drive curve were significant in determining the average and 85th percentile roundabout circulating speed. The developed model was compared with other international models developed in the United States and Italy
Combined effect of frustration and dimerization in ferrimagnetic chains and square lattice
Within the zero-temperature linear spin-wave theory we have investigated the
effect of frustration and dimerization of a Heisenberg system with alternating
spins and on one- and two-dimensional lattices. The combined
effect most visibly appears in the elementary excitation spectra. In contrast
to the ground state energy that decreases with dimerization and increases with
frustration, the excitation energies are shown to be suppressed in energy by
both dimerization and frustration. The threshold value of frustration that
signals a transition from a classical ferrimagnetic state to a spiral state,
decreases with dimerization, showing that dimerization further helps in the
phase transition. The correlation length and sublattice magnetization decrease
with both dimerization and frustration indicating the destruction of the
long-range classical ferrimagnetic. The linear spin wave theory shows that in
the case of a square lattice, dimerization initially opposes the
frustration-led transition to a spiral magnetic state, but then higher
magnitudes of lattice deformation facilitate the transition. It also shows that
the transition to spiral state is inhibited in a square lattice beyond a
certain value of dimerization.Comment: 8 pages, latex, 12 postscript figure
Generating Individual Patient Preferences for the Treatment of Osteoarthritis Using Adaptive Choice-Based Conjoint (ACBC) Analysis.
INTRODUCTION: To explore how adaptive choice-based conjoint (ACBC) analysis could contribute to shared decision-making in the treatment of individual patients with osteoarthritis (OA). METHODS: In-depth case study of three individuals randomly selected from patients with OA participating in an ACBC analysis exercise. Eleven members of a research users' group participated in developing an ACBC task on medication preferences for OA. Individual medication priorities are illustrated by the detailed analysis of ACBC output from three randomly selected patients from the main sample. RESULTS: The case study analysis illustrates individual preferences. Participant 1's priority was avoidance of the four high-risk side effects of medication, which accounted for 90% of the importance of all attributes, while the remaining attributes (expected benefit; way of taking medication; frequency; availability) accounted only for 10% of the total influence. Participant 3 was similar to participant 1 but would accept a high risk of one of the side effects if the medication were available by prescription. In contrast, participant 2's priority was the avoidance of Internet purchase of medication; this attribute (availability) accounted for 52% of the importance of all attributes. CONCLUSIONS: Individual patients have preferences that likely lead to different medication choices. ACBC has the potential as a tool for physicians to identify individual patient preferences as a practical basis for concordant prescribing for OA in clinical practice. Future research needs to establish whether accurate knowledge of individual patient preferences for treatment attributes and levels translates into concordant behavior in clinical practice
Evaluating Carbon Footprint in the Life Cycle Design of Residential Concrete Structures in Jordan
The construction industry is a significant source of greenhouse gas emissions, and there is a growing global interest in reducing the environmental impact of carbon dioxide emissions associated with building construction and operation. Concrete, the most commonly used material in construction, is known to release a substantial amount of environmentally harmful waste throughout its life cycle, including production, construction, operation, and demolition. The worldwide production and consumption of concrete contribute to approximately 5% of all human-related CO2 emissions each year. To assess the carbon footprint of concrete manufacturing and its application in construction projects, a comprehensive approach called life cycle assessment (LCA) is necessary. This paper presents a new process-based LCA approach to analyze carbon emissions and evaluate the carbon footprint of concrete from raw material extraction to the end-of-life stage. To address carbon emissions throughout the life cycle of concrete structures in the Middle East, the study adopts a case study approach, focusing on selected concrete structures in Jordan. The findings from these case studies highlight that the operational phase of concrete structures is the primary contributor to carbon emissions. By thoroughly examining the carbon cycle within structures and their interactions with the surrounding ecosystem, significant reductions in CO2 emissions, environmental deterioration, and its consequences can be achieved. Doi: 10.28991/CEJ-2023-09-07-07 Full Text: PD
The hyperfine properties of a hydrogenated Fe/V superlattice
: We study the effect of hydrogen on the electronic, magnetic and hyperfine
structures of an iron-vanadium superlattice consisting of three Fe monolayers
and nine V monolayers. The contact charge density ({\rho}), the contact
hyperfine field (Bhf) and the electronic field gradient (EFG) at the Fe sites
for different H locations and H fillings are calculated using the first
principle full-potential linear-augmented-plane-wave (FP-LAPW) method . It is
found that sizeable changes in the hyperfine properties are obtained only when
H is in the interface region.Comment: 6 pages, 2 figures, 3 tables, ICAME 2011 conference (Kobe, Japan
Systematic review of studies investigating ventilator associated pneumonia diagnostics in intensive care
Abstract Background Ventilator-associated pneumonia (VAP) is an important diagnosis in critical care. VAP research is complicated by the lack of agreed diagnostic criteria and reference standard test criteria. Our aim was to review which reference standard tests are used to evaluate novel index tests for suspected VAP. Methods We conducted a comprehensive search using electronic databases and hand reference checks. The Cochrane Library, MEDLINE, CINHAL, EMBASE, and web of science were searched from 2008 until November 2018. All terms related to VAP diagnostics in the intensive treatment unit were used to conduct the search. We adopted a checklist from the critical appraisal skills programme checklist for diagnostic studies to assess the quality of the included studies. Results We identified 2441 records, of which 178 were selected for full-text review. Following methodological examination and quality assessment, 44 studies were included in narrative data synthesis. Thirty-two (72.7%) studies utilised a sole microbiological reference standard; the remaining 12 studies utilised a composite reference standard, nine of which included a mandatory microbiological criterion. Histopathological criteria were optional in four studies but mandatory in none. Conclusions Nearly all reference standards for VAP used in diagnostic test research required some microbiological confirmation of infection, with BAL culture being the most common reference standard used
Information security: Listening to the perspective of organisational insiders
Aligned with the strategy-as-practice research tradition, this article investigates how organisational insiders understand and perceive their surrounding information security practices, how they interpret them, and how they turn such interpretations into strategic actions. The study takes a qualitative case study approach, and participants are employees at the Research & Development department of a multinational original brand manufacturer. The article makes an important contribution to organisational information security management. It addresses the behaviour of organisational insiders – a group whose role in the prevention, response and mitigation of information security incidents is critical. The article identifies a set of organisational insiders’ perceived components of effective information security practices (organisational mission statement; common understanding of information security; awareness of threats; knowledge of information security incidents, routines and policy; relationships between employees; circulation of stories; role of punishment provisions; and training), based on which more successful information security strategies can be developed
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