667 research outputs found
Assessment of energy and emissions saving solutions in urban rail-based transport systems
Global warming and climate change are indisputable theories. Since the Industrial
Revolution, the mean temperature of the planet has increased by 1°C. Now, temperatures
are approaching a higher stage of +1.5°C and the attention is on both CO2 emissions and
energy consumption. Transportation is a major component of the environmental impact,
accounting for approximately 30% of air pollution and energy consumption. Due to the
rapid urbanization in the EU, with an estimated 74.3% of the population living in cities,
forecasted to rise to 80% by 2050, urban mobility is dramatically increasing its relevance.
Therefore, a reduction in energy consumption and pollutant emissions is a crucial factor to
consider in developing urban transportation and particularly rail-based systems, able to
provide energy saving transport services by improving urban environment. Several methods
and techniques are under development to improve the energy performance of Light Rail
Transport (LRT), which spread from different typologies of power supply to improving
energy efficiency. The purpose of this paper is to start from the last developments and
innovative energy sources for LRT systems. The focus is on two parts: a) trams running on
Hydrogen in parallel with on board batteries with energy saving control techniques, b)
potential renewable energy sources to meet power demand. The comparison is with
traditional power sources and equipment (e.g. Catenary-based). The methods, based on
selected indicators, are under development and test by calculations and simulations with
reference to the case study of the new tramlines in the city of Brescia (Italy)
Robust Bain distortion in the premartensite phase of platinum substituted Ni2MnGa magnetic shape memory alloy
The premartensite phase of shape memory and magnetic shape memory alloys
(MSMAs) is believed to be a precursor state of the martensite phase with
preserved austenite phase symmetry. The thermodynamic stability of the
premartensite phase and its relation to the martensitic phase is still an
unresolved issue, even though it is critical to the understanding of the
functional properties of MSMAs. We present here unambiguous evidence for
macroscopic symmetry breaking leading to robust Bain distortion in the
premartensite phase of 10% Pt substituted Ni2MnGa. We show that the robust Bain
distorted premartensite (T2) phase results from another premartensite (T1)
phase with preserved cubic-like symmetry through an isostructural phase
transition. The T2 phase finally transforms to the martensite phase with
additional Bain distortion on further cooling. Our results demonstrate that the
premartensite phase should not be considered as a precursor state with the
preserved symmetry of the cubic austenite phase
Direct Measurements of the Magnetocaloric Effect in Pulsed Magnetic Fields
The present thesis is devoted to the investigation of the magnetocaloric effect (MCE) by direct measurements in pulsed and quasi-static magnetic fields as well as by analyzing specific-heat data taken in static magnetic fields. The emphasis is on the direct measurement of the adiabatic temperature change Tad in pulsed magnetic fields, because the pulsed-field data allow for an analysis of the sample-temperature response to the magnetic field on a time scale of 10 to 100 ms, which is on the order of typical operation frequencies (10 - 100 Hz) of magnetocaloric cooling devices. Besides extending the accessible magneticfield range to beyond 70 T, the short pulse duration provides nearly adiabatic conditions during the measurement.
In this work, the magnetocaloric properties of various types of solids are investigated: Gadolinium (Gd) with a second-order transition, Ni50Mn35In15 with multiple magnetic transitions, and La(Fe,Si,Co)13 compounds with first and second-order transitions, depending on the Co concentration.
The adiabatic temperature change of a polycrystalline Gd sample has been measured in pulsed magnetic fields up to 70 T and also in quasi-static fields up to 2 T. A very large adiabatic temperature change of Tad 60 K is observed near the Curie temperature (TC = 294 K) for a field change of 70 T. In addition, we find that this maximum temperature change grows with H2=3.
We have studied the MCE in the shape-memory Heusler alloy Ni50Mn35In15 by direct measurements in pulsed magnetic fields up to 6 and 20 T. The results obtained for 6 T pulses are compared with data extracted from specific-heat experiments. We find a saturation of the inverse MCE, related to the firstorder martensitic transition, with a maximum adiabatic temperature change of Tad = 7 K at 250 K and a conventional field-dependent MCE near the second-order ferromagnetic transition in the austenitic phase. Our results disclose that in shape-memory alloys the different contributions to the MCE and hysteresis effects around the martensitic transition have to be carefully considered for future cooling applications.
Finally, a comparative study of the magnetic and magnetocaloric properties of La(Fe,Si,Co)13 alloys is presented by discussing magnetization, Tad, specificheat, and magnetostriction measurements. The nature of the transition can be changed from first to second order as well as the temperature of the transition can be tuned by varying the Co concentration. The MCE of two samples with nominal compositions of LaFe11:74Co0:13Si1:13 and LaFe11:21Co0:65Si1:11 have been measured in pulsed magnetic fields up to 50 T. We find that LaFe11:74Co0:13Si1:13 with a first-order transition (TC = 198 K) shows half of the net MCE already at low fields (2-10 T). Whereas the MCE of LaFe11:21Co0:65Si1:11 with secondorder transition (TC = 257 K) grows gradually.
The MCE in both compounds reaches almost similar values at a field of 50 T. The MCE results obtained in pulsed magnetic fields of 2 T are in good agreement with data from quasistatic field measurements. The pulsed-field magnetization of both compounds has been measured in fields up to 60 T under nearly adiabatic conditions and compared to steady-field isothermal measurements. The differences between the magnetization curves obtained under isothermal and adiabatic conditions give the MCE via the crossing points of the adiabatic curve with the set of isothermal curves. For LaFe11:74Co0:13Si1:13, a S - T diagram has been constructed from specific-heat measurements in static fields, which is used to extract the MCE indirectly. Magnetostriction measurements are carried out for two compounds in both static and pulsed magnetic fields. For LaFe11:74Co0:13Si1:13, the strain shows a sharp increase.
However, due to cracks appearing in the sample an irreversible magneto-volume effect of about 1% is observed in pulsed magnetic fields. Whereas for LaFe11:21Co0:65Si1:11 the data show a smooth increase of the sample length up to 60 T, and a 1.3% volume increase is obtained. We also find that magnetizing the latter sample in the paramagnetic state is tightly bound to the volume increase and this, likewise for the former sample, gives the main contribution to the entropy change
Build Back Better and Long-Term Housing Recovery: Assessing Community Housing Resilience and the Role of Insurance Post Disaster
The purpose of this research is to better understand community housing resilience and the role of insurance using a Build Back Better Long-term Recovery Housing framework to analyze approaches and effects on long-term housing rebuilding and recovery. A comparative case study approach is taken to assess insurance policies and outcomes following Hurricane Katrina in New Orleans and the Canterbury earthquake sequence in Christchurch, New Zealand, both affluent urban communities with strong insurance markets. Framed within the context of Build Back Better, the community housing and insurance resilience assessment is based on five key indicators;governance, community resources, risk reduction, housing rebuilding funding (funding and speed of funding), and time compression (built environment and periods of recovery time). Public and private insurance schemes for both case studies are identified and are considered together with analysis of insurance claims and other sources of financial support. The findings and results show that recovery is the result of highly interdependent Build Back Better processes. The data suggests that insurance and governance systems greatly influences the onset and overall speed of recovery (time compression), thereby performing a major role in long-term recovery. This research provides an original contribution to disaster recovery knowledge by analyzing insurance claims from two well-documented natural disasters. Additionally, the paper proposes for the singular definition of community housing resilience
Systems and Methods for the Spectral Calibration of Swept Source Optical Coherence Tomography Systems
This dissertation relates to the transition of the state of the art of swept source optical coherence tomography (SS-OCT) systems to a new realm in which the image acquisition speed is improved by an order of magnitude. With the aid of a better quality imaging technology, the speed-up factor will considerably shorten the eye-exam clinical visits which in turn improves the patient and doctor interaction experience. These improvements will directly lower associated medical costs for eye-clinics and patients worldwide. There are several other embodiments closely related to Optical Coherence Tomography (OCT) that could benefit from the ideas presented in this dissertation including: optical coherence microscopy (OCM), full-field OCT (FF-OCT), optical coherence elastography (OCE), optical coherence tomography angiography (OCT-A), anatomical OCT (aOCT), optical coherence photoacoustic microscopy (OC-PAM), micro optical coherence tomography (µ OCT), among others. In recent decades, OCT has established itself as the de-facto imaging process that most ophthalmologists refer to in their clinical practices. In a broader sense, optical coherence tomography is used in applications when low penetration and high resolution are desired.
These applications include different fields of biomedical sciences including cardiology, dermatology, and pulmonary related sciences. Many other industrial applications including quality control and precise measurements have also been reported that are related to the OCT technology. Every new iteration of OCT technology has always come about with advanced signal processing and data acquisition algorithms using mixed-signal architectures, calibration and signal processing techniques. The existing industrial practices towards data acquisition, processing, and image creation relies on conventional signal processing design flows, which extensively employ continuous/discrete techniques that are both time-consuming and costly. The ideas presented in this dissertation can take the technology to a new dimension of quality of service
Disaster recovery in urban communities
Recovery after disasters is becoming a more prominent focal area of research as the geography literature on disaster management embraces a resilience approach. The damaging impacts of natural disasters on individuals are often compounded by problems and failures in managing recovery after the event. Such problems and failures in recovery take on specific dimensions when disaster events damage the well-established and well-functioning but costly infrastructure and built environments of affluent urban societies. In these circumstances, the extent and nature of property damage combines with the specific pattern of economic and institutional resources available and the disaster recovery management applied to shape the long-term recovery process. As such events become more common and costly, it is important to develop systematic knowledge of how to have a successful and organized recovery process, and, curiously, especially in the case of developed countries. There is a need for a better understanding of what constitutes a successful recovery process, what happens with this process, what long-term recovery is, and how to use the process to mitigate future disasters. The purpose of this research is therefore to compare and contrast long-term recovery planning and management following major disasters in order to identify common lessons, challenges, and ways to mitigate future losses and damages. Although recovery is not everywhere managed the same, there are important lessons that can be learned from the experiences of others. In particular, it is worth identifying the effects of local institutions on recovery and the learning processes that occur.
This research seeks to understand and assess disaster recovery in urban communities by examining the relationship between disaster resilience, housing and insurance. This dissertation addresses five research questions, which are addressed in separate chapters, each of which will be published separately:
(1) How to assess urban resilience policies supporting disaster risk reduction approaches? The 100 Resilient Cities (100RC) was launched by the Rockefeller Foundation to build worldwide resilience. An evaluation of each member city Resilient Strategies plan took place using directed and summative content analysis to determine whether or not vulnerability and risk narratives were applied in its disaster risk reduction approaches. The results reveal the differences produced among member cities due to the role of actors and power expressed in the policy design and implementation. The overall findings suggest that the 100RC program has not fundamentally addresses issues related to the Sendai Framework for Disaster Risk Reduction goals to reduce disaster risk and vulnerabilities. While many members identified many disaster risks and challenges among shocks and stresses, most were overlooked when designing and implementing key policies for urban resilience. This research was published as a journal article in a special publication focused on reviewing the five-year progress of the Sendai Framework for Disaster Risk Reduction implementation for insight into lessons and planning (Hofmann Zavareh, 2021).
(2) How do urban-rural linkages in sustainability transitions impact disaster recovery management and recovery? Analysis of urban-rural linkages in recovery from the earthquake events in Christchurch, New Zealand reveal how desired transformations were entangled in rural, national and international linkages. Three key findings are found; (1) the elements in urban-rural linkages framework are interconnected; (2) the relationalities assumed in the framework do not always hold, and (3) emphasis on urban-rural linkages may obscure other geographies of recovery. This reveals the complexity of the task to map spatial flows, linkages and partnerships among urban, peri-urban and rural areas managing transition pathways for sustainable development. This research was published as part of a special peer-reviewed book publication focused on Rural-Urban Linkages for Sustainable Development edited by Armin Kratzer and Jutta Kister with Routledge (Winder & Hofmann Zavareh, 2020).
(3) How to analyze natural disaster damage for specific localized regions to obtain calculations of losses for communities managing recovery using economic models? Micro-level assessments of regional and local disaster impacts in tourist destinations provide the opportunity for economic geographers to assist in calculating precise damage assessments at small regional scales that in turn support the tourism sector and other inter-dependent economies facing reconstruction challenges after disasters. To calculate precise damage assessments, a micro-level assessment model is developed. The island of Dominica is chosen as an example for the model using statistical data from the tourism sector to outline and detail the consequences of a disaster specifically for communities. The results highlight the importance of damage assessments on a small-scale level needed for communities to better understand impacts for residents and the local tourism sector. Only after identifying regional impacts, it is then possible to apply adequate disaster recovery financing needed for residents and the tourism sector recovery. This research was published in the Tourism Geographies journal as part of the Tourism in Changing Natural Environments special publication (Schmude et al., 2018).
(4) How to measure long-term community housing recovery using dynamic economic resilience? The research assesses long-term housing recovery and community resilience in the case of Broadmoor, a community located in New Orleans. The community long-term housing measurement is calculated using housing recovery scenarios (dynamic economic resilience). The dynamic economic resilience scenario results provide an indication as to how significant implementation of new disaster recovery policies and procedures can be centered on a more efficient handling of applications for building permits, as well as financial claims for rebuilding or buy-outs, and a more effective management of constrained reconstruction resources for community resilience rebuilding. These results also support recent Munich Re disaster risk modeling studies to improve flood protection in New Orleans. This case demonstrates the role of measuring long-term housing is necessary to better understand the housing recovery processes in different market types. The Broadmoor case also highlights that the speed of recovery was greatly influenced by adopting a community-based approach to managing local and regional resources. This research has been accepted for publication as a journal article in Environmental Hazards (Zavareh & Winder, 2021).
(5) What is the role of insurance in managing overall community recovery and housing resilience? The role of insurance, and government buy-outs in recovery are explored in two case study communities (Broadmoor, New Orleans and Avonside, Christchurch). Analysis of case studies using a framework based on “Build Back Better” demonstrating the role of insurance embedded in the scale of long-term housing recovery processes in different market types. Regardless of how the financing or insurance scheme was employed, the most significant factor appears to be the rate (time compression) at which households were able to successfully access and implement financial resources. These two aspects of time compression are interconnected for the success of financing recovery schemes. Successive events or extreme events as seen in both cases, placed considerable burdens on complex institutional systems (local, state, national) that are often disruptive in a nonlinear recovery process. The cases highlight the speed of recovery as the main influencer of long-term housing recovery, given that personal liability is rather manageable if able to access funding for rebuilding efforts. This suggests that a reconceptualization of what exactly community housing resilience is, is needed as it relates to the field of disaster recovery. Here resilience is the opposite of simply rebuilding, contesting the current housing recovery paradigm in “Build Back Better” and disasters research. This research is currently under review for publication.
There is still much to be learned about disaster resilience, sustainability transitions, measuring disaster damages and losses, as well as housing recovery for long-term community resilience. Future research should aim to provide more robust modeling and attempt to bridge the gaps in literature and knowledge in collaboration with community stakeholders of post-disaster recovery
Resource-based industrialisation in Southern Africa: Domestic policies, corporate strategies and regional dynamics
Abstract: This article analyses policies and strategies adopted by Botswana, Zambia and Zimbabwe in order to develop linkage industries from the mineral sector. Whilst Southern Africa has a strongly integrated regional value chain for equipment and services related to mining, linkage development strategies in the three countries under examination have been formulated within narrow domestic frameworks. The evidence suggests that the success or failure of a resource-based industrialisation approach is country and sector specific, requiring the deployment of different and appropriately tailored policy instruments. Our research uncovered important cross-country variations in terms of opportunities created by specific mineral commodities, ambition and scope of industrial and linkage development strategies, and institutional capabilities to ensure enforcement and coherence with other policies
The Effects of Marriage and Divorce on Women's Nationality in the Iranian Law
As the first and foremost social institution, the family significantly impacts its immediate larger society. Also, the importance of family as a key figure in a healthy society and the necessity of strong relations between spouses make it imperative to devise the required legal devices. As women are prone to suffer and receive more damage in cases of family breakdown, the legislator should develop and establish more protective statutes concerning women's rights. This study uses legal research methods with a qualitative approach. To protect Iranian women's rights, the legislator distinguishes cases where an Iranian woman marries a foreign man and those where Iranian men marry foreign women. In the former case, the wife's change, or retention, of nationality is subject to the laws of the husband’s State. In contrast, in the latter case, the legislator enforces the unity of nationality principle. Marriage between Iranian women and foreign men causes women to experience many changes and limitations regarding their national and inheritance rights. Also, they may lose their Iranian nationality due to their marriage —in cases when the husband’s nationality, due to the law of the husband's State, is forced upon the wife. On the other hand, foreign women married to Iranian men, though forced to accept Iranian nationality, encounter fewer limitations resulting from marriage. Upon Divorce, they are neither forced to accept a nationality, unlike when marriage is celebrated, nor denied their Iranian nationality. They can choose whether to remain an Iranian national or recover their original nationality
Coenzyme Q10 Improves Developmental Competence of Mice Pre_antral Follicle Derived From Vitrified Ovary
    The aim of this study was to investigate the in vitro developmental competence of isolated pre-antral follicles derived from vitrified ovaries in the presence of coenzyme Q10 (CoQ10). Mice pre-antral follicles derived from fresh and vitrified-warmed ovarian tissues were in vitro cultured individually in α-MEM medium supplemented with or without CoQ10, followed by adding human Chorionic Gonadotropin (hCG) to induce ovulation. The follicle development parameters and ovulated oocyte maturationwere assessed.The diameter and development of pre-antral follicles and oocyte maturation rates were significantly higher in CoQ10 pretreatment groups of both vitrified and fresh samples compared to the respective CoQ10free conditions groups. CoQ10 improves the in vitrodevelopment of pre-antral follicles derived from fresh and vitrified –warmed ovaries
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