8 research outputs found
Numerical Analysis and Field Validation of Airfield Pavement Responses for the SMART Runway at Hill AFB
No full textEngineering zeolite pellets for the adsorption of organic micropollutants
No full textOur use of pharmaceuticals, pesticides and personal care products leads to an increase of organic micropollutants (OMPs) into the aquatic environment. Conventional wastewater treatment plants are not designed for the removal of OMPs and need to be upgraded to reduce OMP contamination. The adsorption of OMPs to zeolites is proposed as an alternative treatment method. Zeolites are synthesized as powders, however they need to be shaped into pellets to be used in water treatment practice. This research focussed on engineering zeolite pellets and which properties of these pellets are important for the adsorption of OMPs. First the influence of the calcination temperature and binder content on the mechanical stability and porosity of the pellets was analysed. Second, the influence of two different preparation techniques (extrusion and high-shear granulation) and the introduction of a polymer on the mechanical stability, porosity and adsorption kinetics of the pellets was assessed. Third, the effect of the porosity on the breakthrough for an empty bed contact time (EBCT) of 20, 5 and 1 minute(s) was determined according to the linear driving force (LDF) model. It was found that an increasing binder content and calcination temperature increased the wear resistance and porosity of the pellets. However, the effect on the porosity is minimal. The introduction of the polymer had opposite effect on extruded and granulated pellets. For extruded pellets, the introduction of the polymer increased the porosity. However, the granulated pellets showed a decrease in porosity. A relation was found between the porosity and the wear resistance and between the porosity and adsorption kinetics. A larger porosity decreased the wear resistance of the pellets and increased the kinetic rate constant. The porosity was of great importance in relation to the breakthrough. First, the porosity in the zeolite pellets determined to a great extent the bulk density of the filter bed. A higher bulk density resulted in a later breakthrough point. The bulk density was also influenced by the shape of the pellet. Spherically-shaped (granulated) pellets had a higher bulk density than rod-shaped (extruded) pellets. Second, the porosity was related to the kinetic rate constant. At lower EBCTs (5 and 1 minute), the kinetic rate constant had an influence on the breakthrough point. For these EBCTs, a higher kinetic rate constant led to a later breakthrough point. It was recommended to optimize the zeolite pellets by making the extruded pellets in a more spherically-shaped form and to start column experiments to validate the LDF-model
The work that parks do: urban environmental management and its alternatives
No full textAs cities come to be seen as both the source of and the possible solution to a variety of environmental concerns, and as hubs of economic activity, it is increasingly important to understand the shifting meanings that are applied to them, their economies, and their connection to the non-human world. In this dissertation, I examine the city as a site of environmental discourse formation, where knowledge about the environment is produced, shaped, and changed, and where notions of “nature” and “society” develop in conjunction with an emerging understanding of environmental responsibility and identity. Through an examination of the establishment of urban parks in Philadelphia from the 19th century to the present, this project sheds light on the processes through which the urban and the natural have been and continue to be constituted. The central concern of this project is to understand how and why a particular knowledge of urban nature emerged, to uncover the techniques employed that produce and reinforce it, and to trace the positioning of subjects within urban, economic, and environmental discourses. To do this, I identify the sites in which this discourse is (re)produced, the disciplinary techniques and specific practices that produce parks as unique kinds of spaces or landscapes in the city, and the consequences of these framings for the way cities are imagined. I employ a range of research methods that includes text analysis, visual discourse analysis, participant observation, and focus group interviewing techniques.Ph.D.Includes bibliographical referencesby Nathaniel Joseph Gabrie
Thermo-physical characterization of Pharmacoatr 603, Pharmacoatr 615 and Mowiolr 4-98
No full textChemical EngineeringApplied Science
The impact of dairy food, vitamin D and calcium consumption on women's health through the life-course
No full textEndometrial and ovarian cancers are hormone related cancers with the most significant risk factors being those related to high estrogen exposure, such as late age at menopause and hormone therapy use. Diet and obesity, two modifiable risk factors, have been implicated in the risk for both cancers. Early life exposures including diet, as well as early onset of puberty, may play a role in the lifetime risk of endometrial and ovarian cancers. Dairy foods, vitamin D and calcium have been implicated in endometrial and ovarian cancer risk, playing either a direct role or an indirect role through their association with body size. A major source of dietary vitamin D and calcium, dairy foods are also sources of animal derived hormones and growth factors which may have physiologic activity in humans. Obesity is a known risk factor for early sexual development in girls, possibly due to estrogen synthesis in adipose tissue. In this study, data from two population based case-control studies and baseline data from a prospective cohort study were used to examine the association between dairy foods, vitamin D and calcium with risk of endometrial cancer, ovarian cancer, and early breast development and body size in pre-pubertal girls, respectively. Endometrial cancer risk was significantly inversely associated with dietary calcium intake in our study. Among post menopausal women, high versus low intake of total calcium was associated with significantly lower risk of endometrial cancer. Less frequent consumption of low-fat cheese was associated with significantly greater risk of endometrial cancer compared to frequent consumption of low-fat type. Effect modification was found by hormone therapy use for total calcium and risk of endometrial cancer, with ‘ever’ users having greater risk compared to ‘never’ users. Milk intake was significantly associated with ovarian cancer risk; significant effect modification by hormone therapy use was found for the association between ovarian cancer risk and total vitamin D intake, with ‘ever’ users having lower risk estimates versus ‘never’ users. Higher dietary calcium intake was associated with lower mean BMI, fat mass and percent body fat among young girls, while higher total milk and dairy intake were associated with higher adiposity measures. Girls in the highest tertile of total milk were significantly more likely to be overweight and above, as were those in the middle tertile of dietary calcium. In conclusion, our results suggest a possible protective role for calcium with risk of endometrial cancer and reduced adiposity in young girls, and an increased risk for ovarian cancer risk with milk intake. Future research should build on these findings by further elucidating calcium’s role in endometrial and ovarian cancer risk and body size in young girls through larger studies focused on high risk populations (i.e., obese and post-menopausal women, young girls) as well as associations with epithelial ovarian cancer tumor sub-types.Ph.D.Includes bibliographical referencesby Susan Gabrie
Gas-Phase Deposition of Ultrathin Aluminium Oxide Films on Nanoparticles at Ambient Conditions
No full textWe have deposited aluminium oxide films by atomic layer deposition on titanium oxide nanoparticles in a fluidized bed reactor at 27 ± 3 °C and atmospheric pressure. Working at room temperature allows coating heat-sensitive materials, while working at atmospheric pressure would simplify the scale-up of this process. We performed 4, 7 and 15 cycles by dosing a predefined amount of precursors, i.e., trimethyl aluminium and water. We obtained a growth per cycle of 0.14–0.15 nm determined by transmission electron microscopy (TEM), similar to atomic layer deposition (ALD) experiments at a few millibars and ~180 °C. We also increased the amount of precursors dosed by a factor of 2, 4 and 6 compared to the base case, maintaining the same purging time. The growth per cycle (GPC) increased, although not linearly, with the dosing time. In addition, we performed an experiment at 170 °C and 1 bar using the dosing times increased by factor 6, and obtained a growth per cycle of 0.16 nm. These results were verified with elemental analysis, which showed a good agreement with the results from TEM pictures. Thermal gravimetric analysis (TGA) showed a negligible amount of unreacted molecules inside the alumina films. Overall, the dosage of the precursors is crucial to control precisely the growth of the alumina films at atmospheric pressure and room temperature. Dosing excess of precursor provokes a chemical vapour deposition type of growth due to the physisorption of molecules on the particles, but this can be avoided by working at high temperatures.ChemE/Chemical EngineeringApplied Science
Can solar radiation management cool earth without reducing precipitation in heavily populated and cultivated regions?
No full textGeoengineering is the large-scale intentional manipulation of climate processes designed to reduce global temperature. Absent the implementation of an effective global mitigation strategy, it may be difficult to avoid experiencing an amount of anthropogenic global warming that would adversely impact both civilization and natural ecosystems without solar radiation management (SRM) geoengineering. One of the major issues with global warming is a possible increase in tropical precipitation over already wet tropical land regions. A major risk associated with stratospheric SRM, an intervention designed to reduce the impacts of global warming, is a reduction of tropical precipitation over land. In this thesis, I will explore the climate response to SRM with a special focus on impacts in tropical regions, particularly with regard to changes in precipitation patterns. Changes in the El Niño Southern Oscillation (ENSO) are either not present in Geoengineering Model Intercomparison Project (GeoMIP) G1-G4 output, or not detectable, due to the short simulation duration and to the large inherent variability of ENSO. The changes in precipitation distribution and monsoon strength relative to anthropogenic global warming or the historical climate under G1-G4 cannot be attributed to changes in ENSO. After determining that no possible marine cloud brightening scheme could be an effective method of cooling Earth without reducing tropical precipitation, in heavily populated, highly cultivated tropical regions, I developed the G4Foam experiment, which achieved significant global cooling and a large redistribution of precipitation from ocean to land. No direct forcing was applied to tropical latitudes, but G4Foam cooled the tropics by 0.6 K, while increasing precipitation in most areas, including areas that typically get less precipitation with global warming. However, the Southern Hemisphere (SH) regional forcing was, as expected, not effective in cooling Northern Hemisphere (NH) continents. In an attempt to cool the entire planet while maintaining tropical precipitation at present day levels, I combined stratospheric solar radiation management and regional ocean albedo enhancement in designing the G4SSAFoam experiment. In this experiment, 1.5 K of global mean cooling was achieved and tropical precipitation remained at or near RCP6.0 levels and slightly above G4SSA levels. However, the spatial distribution of positive and negative precipitation and precipitation minus evaporation (P-E) anomalies in the tropics was heterogeneous, with some heavily populated areas experiencing large increases, while others experience large decreases. The severe cooling of about 2 K in the SH extratropics causes a precipitation reduction of almost 6% in G4SSAFoam when compared to RCP6.0. While P-E anomalies over land in the SH are only negative in certain regions, future research would be needed to determine the full societal and ecological impact of the SH extratropical temperature and precipitation perturbations. The deployment of microbubbles in the ocean is currently not possible and significant innovation would need to occur if a need to conduct geoengineering in the manner of G4Foam arose, for example, in the event of a stratospheric solar radiation management deployment that reduced tropical precipitation to the extent that it or reduced tropical temperature.Ph.D.Includes bibliographical referencesby Corey J. Gabrie
Accessible Ocean Tourism-Opening the blue frontier-Why accessibility matters -bridging the gap
No full textAccessible Ocean Tourism research on the gaps and solutions, keeping in mind the UN Goals- leaving no one behind, UN Disability rights. How islands and coastal communities can bridge the gap. Studying and Outlining policy for governments and institutions, hospitality, universities globally, inclusion in curriculums and career skills/certifications/expertise in tourism sectors.
Author-Elsie Gabriel Founder Young Environmentalists Programme Trust
Founder Ocean School India Foundation
Ambassador for India-Global Ocean Quest
National Coordinator Oceans Climate Reality Project Asia
Consultant Lakshadweep Islands Climate Mitigation
Handicapped Scuba Association Certified
Member Global Sustainable Tourism Council
Member of Association of Accessibility Professionals.
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Accessible Ocean Tourism – Opening the Blue Frontier:
Why Accessibility Matters in Ocean Tourism
Elsie Gabriel
Independent Researcher – Accessible & Sustainable Tourism
Abstract
Accessible Ocean Tourism is a critical yet underdeveloped dimension of sustainable
tourism and the blue economy. This paper examines accessibility as a prerequisite for
equitable participation in ocean-based tourism, with particular attention to persons with
disabilities and other marginalised groups. Drawing on international accessibility
frameworks, tourism policy developments, and applied practice examples, the study
conceptualises the “Blue Frontier” as both an economic opportunity and a social
responsibility. The paper analyses persistent barriers within ocean and coastal tourism,
including inaccessible infrastructure, limited adaptive equipment, insufficient staff training,
fragmented information systems, and weak integration of accessibility into tourism planning
and regulation. Emphasis is placed on the role of human capital, digital skills, inclusive
design, and cross-sector collaboration in operationalising accessible ocean tourism.
Positioned within the broader commitments of the UN 2030 Agenda and the principle of
leaving no one behind, the paper argues that Accessible Ocean Tourism is not a niche
market, but a core pillar of resilient, inclusive, and sustainable coastal destinations.
1. Introduction: The Blue Frontier
The Blue Frontier refers to the vast opportunities offered by oceans and coastal regions,
encompassing leisure tourism, water sports, cruises, coastal attractions, and underwater
exploration. It is closely linked to the broader concept of the Blue Economy, which
promotes sustainable use of ocean resources for economic growth, improved livelihoods,
and ecosystem health. Despite its growth potential, access to ocean tourism remains
uneven, particularly for persons with disabilities.
2. Importance of Accessible Tourism
Accessible tourism enables people with mobility, sensory, and cognitive access
requirements to participate independently, with equity and dignity, through universally
designed tourism products, services, and environments. Accessibility extends beyond
infrastructure to include transport, trained staff, accessible information systems, and
inclusive activities. Demographic trends and spending data demonstrate that travelers with
disabilities represent a substantial and underserved market.
3. Barriers in Ocean and Coastal TourismPersistent barriers include inaccessible websites, limited wheelchair-accessible transport,
lack of adapted hotel rooms, insufficiently trained personnel, unreliable accessibility
information, inaccessible public spaces, and limited availability of adaptive equipment.
These barriers restrict participation and undermine the sustainability and inclusivity of
coastal destinations.
4. Accessibility, Skills, and Sustainability
Human capital plays a central role in accessible tourism. Social skills, empathy,
communication, and personalised service delivery are essential. Digital technologies,
including accessible online platforms, virtual tools, and data systems, offer new
opportunities to enhance inclusive tourist experiences. Integrating accessibility within
sustainability strategies strengthens environmental stewardship, community engagement,
and economic resilience.
5. Examples of Accessible Ocean Tourism
Practical applications include accessible beaches with mobility mats and beach
wheelchairs, adapted diving and snorkelling programmes, accessible boat tours with
ramps and onboard facilities, and inclusive water sports supported by trained staff and
adaptive equipment. Clear, accessible information across digital and physical platforms is
essential to enable informed travel decisions.
6. Conclusion: Leave No One Behind
As oceans cover more than 70 percent of the planet, ensuring equitable access to their
benefits is both a moral and strategic imperative. Accessible Ocean Tourism aligns with the
UN 2030 Agenda by promoting dignity, opportunity, and participation for all. By embedding
accessibility into sustainable tourism frameworks, coastal destinations can ensure that the blue frontier truly leaves no one behind
Elsie Gabrie
