Factors affecting the design and construction of Lamella suspen-dome systems

The suspen-dome system is a new structural form that has become popular in the construction of long-span roof structures. These domes are very slender and lightweight, their configuration is complicated, and hence sequential consideration in the structural design is needed. This paper focuses on these considerations, which include the method for designing cable prestress force, a simplified analysis method, and the estimation of buckling capacity. Buckling is one of the most important problems for dome structures. This paper presents the findings of an intensive buckling study of the Lamella suspen-dome system that takes geometric imperfection, asymmetric loading, rise-to-span ratio, and connection rigidity into consideration. Finally, suggested design and construction guidelines are given in the conclusion of this paper. (c) 2005 Elsevier Ltd. All rights reserved.

Design and construction of an ultrasonic probe for use in a Cryo-Magnet NMR Spectrometer

SINNMR (Sonically Induced Narrowing of the Nuclear Magnetic Resonance spectra of solids), is a novel technique that is being developed to enable the routine study of solids by nuclear magnetic resonance spectroscopy. SINNMR aims to narrow the broad resonances that are characteristic of solid state NMR by inducing rapid incoherent motion of solid particles suspended in a support medium, using high frequency ultrasound in the range 2-10 MHz. The width of the normal broad resonances from solids are due to incomplete averaging of several components of the total spin Hamiltonian caused by restrictions placed on molecular motion within a solid. At present Magic Angle Spinning (MAS) NMR is the classical solid state technique used to reduce line broadening, but: this has associated problems, not least of which is the appearance of many spinning side bands which confuse the spectra. It is hoped that SlNNMR will offer a simple alternative, particularly as it does not reveal spinning sidebands The fundamental question concerning whether the use of ultrasound within a cryo-magnet will cause quenching has been investigated with success, as even under the most extreme conditions of power, frequency and irradiator time, the magnet does not quench. The objective of this work is to design and construct a SINNMR probe for use in a super conducting cryo-magnet NMR spectrometer. A cell for such a probe has been constructed and incorporated into an adapted high resolution broadband probe. It has been proved that the cell is capable of causing cavitation, up to 10 MHz, by running a series of ultrasonic reactions within it and observing the reaction products. It was found that the ultrasound was causing the sample to be heated to unacceptable temperatures and this necessitated the incorporation of temperature stabilisation devices. Work has been performed on the investigation of the narrowing of the solid state 23Na spectrum of tri-sodium phosphate using high frequency ultrasound. Work has also been completed on the signal enhancement and T1 reduction of a liquid mixture and a pure compound using ultrasound. Some preliminary "bench" experiments have been completed on a novel ultrasonic device designed to help minimise sample heating. The concept involves passing the ultrasound through a temperature stabilised, liquid filled funnel that has a drum skin on the end that will enable the passage of ultrasound into the sample. Bench experiments have proved that acoustic attenuation is low and that cavitation in the liquid beyond the device is still possible.

Estimation of global beta and tests of capital asset pricing models

With the rapid globalization and integration of world capital markets, more and more stocks are listed in multiple markets. With multi-listed stocks, the traditional measurement of systematic risk, the domestic beta, is not appropriate since it only contain information from one market. ^ Prakash et al. (1993) developed a technique, the global beta, to capture information from multiple markets wherein the stocks are listed. In this study, the global betas are obtained as well as domestic betas for 704 multi-listed stocks from 59 world equity markets. Welch tests show that domestic betas are not equal across markets, therefore, global beta is more appropriate in a global investment setting. ^ The traditional Capital Asset Pricing Models (CAPM) is also tested with regards to both domestic beta and global beta. The results generally support the positive relationship between stocks returns and global beta while tend to reject this relationship between stocks returns and domestic beta. Further tests of International CAPM with domestic beta and global beta strengthen the conclusion.^

Analysis of global compliance and implementation of the goals of international environmental treaties: A case study of the Convention on Biodiversity (CBD)

The Convention on Biodiversity (CBD) was created in 1992 to coordinate global governments to protect biological resources. The CBD has three goals: protection of biodiversity, achievement of sustainable use of biodiversity and facilitation of equitable sharing of the benefits of biological resources. The goal of protecting biological resources has remained both controversial and difficult to implement. This study focused more on the goal of biodiversity protection. The research was designed to examine how globally constructed environmental policies get adapted by national governments and then passed down to local levels where actual implementation takes place. Effectiveness of such policies depends on the extent of actual implementation at local levels. Therefore, compliance was divided and examined at three levels: global, national and local. The study then developed various criteria to measure compliance at these levels. Both qualitative and quantitative methods were used to analyze compliance and implementation. The study was guided by three questions broadly examining critical factors that most influence the implementation of biodiversity protection policies at the global, national and local levels. Findings show that despite an overall biodiversity deficit of 0.9 hectares per person, global compliance with the CBD goals is currently at 35%. Compliance is lowest at local levels at 14%, it is slightly better at national level at 50%, and much better at the international level 64%. Compliance appears higher at both national and international levels because compliance here is paper work based and policy formulation. If implementation at local levels continues to produce this low compliance, overall conservation outcomes can only get worse than what it is at present. There are numerous weaknesses and capacity challenges countries are yet to address in their plans. In order to increase local level compliance, the study recommends a set of robust policies that build local capacity, incentivize local resource owners, and implement biodiversity protection programs that are akin to local needs and aspirations.^

The geographies of encounter: investigating the spatiality and construction of 'meaningful' encounters with difference through the experiences of international students at University College Cork, Ireland

The purpose of this research is to investigate how international students negotiate encounters with Irish students and construct ‘meaning’ from those encounters in the spaces of the university and city. As cities are increasingly characterised by a multiplexity of diversity, the issue of living with difference is becoming more and more pertinent. In the wake of escalating socio-spatial polarisation, inter-cultural tension, racism, and xenophobia, the geographies of encounter seek to untangle the interactions that occur in the quotidian activities and spaces of everyday life to determine whether such encounters might reduce prejudice, antipathy and indifference and establish common social bonds (Amin 2002; Valentine 2008). Thus far, the literature has investigated a number of sites of encounter; public space, the home, neighbourhoods, schools, sports clubs, public transport, cafes and libraries (Wilson 2011; Schuermans 2013; Hemming 2011; Neal and Vincent 2011; Mayblin, Valentine and Anderrson 2015; Laurier and Philo 2006; Valentine and Sadgrove 2013; Harris, Valentine and Piekut 2014; Fincher and Iveson 2008). While these spaces produce a range of outcomes, the literature remains frustrated by a lack of clarity of what constitutes a ‘meaningful’ encounter and how such encounters might be planned for. Drawing on survey and interview data with full-time international students at University College Cork, Ireland, this study contributes to understanding how encounters are shaped by the construction and reproduction of particular identities in particular spaces, imbuing spaces with uneven power frameworks that produce diverse outcomes. Rather than identifying a singular ‘meaningful’ outcome of encounter as a potential panacea to the issues of exclusion and oppression, the contention here is to recognise a range of outcomes that are created by individuals in a range of ways. To define one outcome of encounter as ‘meaningful’ is to overlook the scale of intensity of diverse interactions and the multiplicity of ways in which people learn to live with difference.

Analysis of Global Compliance and Implementation of the Goals of International Environmental Treaties: A Case study of the Convention on Biodiversity (CBD)

The Convention on Biodiversity (CBD) was created in 1992 to coordinate global governments to protect biological resources. The CBD has three goals: protection of biodiversity, achievement of sustainable use of biodiversity and facilitation of equitable sharing of the benefits of biological resources. The goal of protecting biological resources has remained both controversial and difficult to implement. This study focused more on the goal of biodiversity protection. The research was designed to examine how globally constructed environmental policies get adapted by national governments and then passed down to local levels where actual implementation takes place. Effectiveness of such policies depends on the extent of actual implementation at local levels. Therefore, compliance was divided and examined at three levels: global, national and local. The study then developed various criteria to measure compliance at these levels. Both qualitative and quantitative methods were used to analyze compliance and implementation. The study was guided by three questions broadly examining critical factors that most influence the implementation of biodiversity protection policies at the global, national and local levels. Findings show that despite an overall biodiversity deficit of 0.9 hectares per person, global compliance with the CBD goals is currently at 35%. Compliance is lowest at local levels at 14%, it is slightly better at national level at 50%, and much better at the international level 64%. Compliance appears higher at both national and international levels because compliance here is paper work based and policy formulation. If implementation at local levels continues to produce this low compliance, overall conservation outcomes can only get worse than what it is at present. There are numerous weaknesses and capacity challenges countries are yet to address in their plans. In order to increase local level compliance, the study recommends a set of robust policies that build local capacity, incentivize local resource owners, and implement biodiversity protection programs that are akin to local needs and aspirations.

A comparison of individual cow versus group concentrate allocation strategies on dry matter intake, milk production, tissue changes, and fertility of Holstein-Friesian cows offered a grass silage diet

A diverse range of concentrate allocation strategies are adopted on dairy farms. The objectives of this study were to examine the effects on cow performance [dry matter (DM) intake (DMI), milk yield and composition, body tissue changes, and fertility] of adopting 2 contrasting concentrate allocation strategies over the first 140 d of lactation. Seventy-seven Holstein-Friesian dairy cows were allocated to 1 of 2 concentrate allocation strategies at calving, namely group or individual cow. Cows on the group strategy were offered a mixed ration comprising grass silage and concentrates in a 50:50 ratio on a DM basis. Cows on the individual cow strategy were offered a basal mixed ration comprising grass silage and concentrates (the latter included in the mix to achieve a mean intake of 6 kg/cow per day), which was formulated to meet the cow’s energy requirements for maintenance plus 24 kg of milk/cow per day. Additional concentrates were offered via an out-of-parlor feeding system, with the amount offered adjusted weekly based on each individual cow’s milk yield during the previous week. In addition, all cows received a small quantity of straw in the mixed ration part of the diet (approximately 0.3 kg/cow per day), plus 0.5 kg of concentrate twice daily in the milking parlor. Mean concentrate intakes over the study period were similar with each of the 2 allocation strategies (11.5 and 11.7 kg of DM/cow per day for group and individual cow, respectively), although the pattern of intake with each treatment differed over time. Concentrate allocation strategy had no effect on either milk yield (39.3 and 38.0 kg/d for group and individual cow, respectively), milk composition, or milk constituent yield. The milk yield response curves with each treatment were largely aligned with the concentrate DMI curves. Cows on the individual cow treatment had a greater range of concentrate DMI and milk yields than those on the group treatment. With the exception of a tendency for cows on the individual cow treatment to lose more body weight to nadir than cows on the group treatment, concentrate allocation strategy had little effect on either body weight or body condition score over the experimental period. Cows on the individual cow treatment had a higher pregnancy rate to first and second service and tended to have a higher 100-d in calf rate than cows on the group treatment. This study demonstrates that concentrate allocation strategy had little effect on overall production performance.

Vibro-acoustic analysis and design optimization to improve comfort and sustainability of future passenger aircraft

Due to the interest of general public and the industrial stakeholders, new challenges and demands are rising in aircraft design. The sustainability is taking its place amongst more traditional design factors, such as safety, performances and costs. Sustainability is both environmental and economic, and among the factors contributing to economic sustainability, there is also passengers' comfort. In order to win these two challenges, they must be considered in the early stages of aircraft design. In this work, the focus is on emissions generation and acoustic comfort, aiming at reducing pollution and internal noise in the preliminary design phases. These results can be achieved with both unconventional aircraft configurations and advanced materials, which also require new numerical formulations to be assessed. In this research, on one hand, the windowless configuration for a commercial aircraft is studied with traditional preliminary design methods in order to achieve a weight reduction and consequently a return in terms of emissions and costs. On the other hand, a new class of insulating materials, the acoustic metamaterials, is applied on the passenger cabin lining panels. The complex kinematic behaviour of these advanced materials is studied through the Carrera's Unified Formulation, that enhances a wide class of powerful refined shell and beam theories with a unique formulation.

Brazil's global aspirations and their implications for the relationship with Argentina in the framework of MERCOSUR

Dissertação de mestrado em Relações Internacionais

The construction and optimization of an ion mobility spectrometer for the analysis of explosives and drugs

Today, over 15,000 Ion Mobility Spectrometry (IMS) analyzers are employed at worldwide security checkpoints to detect explosives and illicit drugs. Current portal IMS instruments and other electronic nose technologies detect explosives and drugs by analyzing samples containing the headspace air and loose particles residing on a surface. Canines can outperform these systems at sampling and detecting the low vapor pressure explosives and drugs, such as RDX, PETN, cocaine, and MDMA, because these biological detectors target the volatile signature compounds available in the headspace rather than the non-volatile parent compounds of explosives and drugs.^ In this dissertation research volatile signature compounds available in the headspace over explosive and drug samples were detected using SPME as a headspace sampling tool coupled to an IMS analyzer. A Genetic Algorithm (GA) technique was developed to optimize the operating conditions of a commercial IMS (GE Itemizer 2), leading to the successful detection of plastic explosives (Detasheet, Semtex H, and C-4) and illicit drugs (cocaine, MDMA, and marijuana). Short sampling times (between 10 sec to 5 min) were adequate to extract and preconcentrate sufficient analytes (> 20 ng) representing the volatile signatures in the headspace of a 15 mL glass vial or a quart-sized can containing ≤ 1 g of the bulk explosive or drug.^ Furthermore, a research grade IMS with flexibility for changing operating conditions and physical configurations was designed and fabricated to accommodate future research into different analytes or physical configurations. The design and construction of the FIU-IMS were facilitated by computer modeling and simulation of ion’s behavior within an IMS. The simulation method developed uses SIMION/SDS and was evaluated with experimental data collected using a commercial IMS (PCP Phemto Chem 110). The FIU-IMS instrument has comparable performance to the GE Itemizer 2 (average resolving power of 14, resolution of 3 between two drugs and two explosives, and LODs range from 0.7 to 9 ng). ^ The results from this dissertation further advance the concept of targeting volatile components to presumptively detect the presence of concealed bulk explosives and drugs by SPME-IMS, and the new FIU-IMS provides a flexible platform for future IMS research projects.^

Integrated assessment of agricultural sustainability: the pros and cons of reductionism

In this paper I review a series of theoretical concepts that are relevant for the integrated assessment of agricultural sustainability but that are not generally included in the curriculum of the various scientific disciplines dealing with quantitative analysis of agriculture. I first illustrate with plain narratives and concrete examples that sustainability is an extremely complex issue requiring the simultaneous consideration of several aspects, which cannot be reduced into a single indicator of performance. Following, I justify this obvious need for multi-criteria analysis with theoretical concepts dealing with the epistemological predicament of complexity, starting from classic philosophical lessons to arrive to recent developments in complex system theory, in particular Rosen´s theory of modelling relation which is essential to analyze the quality of any quantitative representation. The implications of these theoretical concepts are then illustrated with applications of multi-criteria analysis to the sustainability of agriculture. I wrap up by pointing out the crucial difference between "integrated assessment" and "integrated analysis". An integrated analysis is a set of indicators and analytical models generating an analytical output. An integrated assessment is much more than that. It is about finding an effective way to deal with three key issues: (i) legitimacy – how to handle the unavoidable existence of legitimate but contrasting points of view about different meanings given by social actors to the word "development"; (ii) pertinence – how to handle in a coherent way scientific analyses referring to different scales and dimensions; and (iii) credibility – how to handle the unavoidable existence of uncertainty and genuine ignorance, when dealing with the analysis of future scenarios.

Construction of the Iowa Highway 60 Precast Prestressed Concrete Pavement Bridge Approach Slab Demonstration Project, HR-1085, 2007

Reconstruction of bridge approach slabs which have failed due to a loss of support from embankment fill consolidation or erosion can be particularly challenging in urban areas where lane closures must be minimized. Precast prestressed concrete pavement is a potential solution for rapid bridge approach slab reconstruction which uses prefabricated pavement panels that can be installed and opened to traffic quickly. To evaluate this solution, the Iowa Department of Transportation constructed a precast prestressed approach slab demonstration project on Highway 60 near Sheldon, Iowa in August/September 2006. Two approach slabs at either end of a new bridge were constructed using precast prestressed concrete panels. This report documents the successful development, design, and construction of the precast prestressed concrete bridge approach slabs on Highway 60. The report discusses the challenges and issues that were faced during the project and presents recommendations for future implementation of this innovative construction technique.