3,295 research outputs found

    Aspects of Higgs Production at the LHC

    Get PDF
    We discuss the main features and predictions of the GLMM model, which is based on a QCD motivated theoretical approach, and successfully describes the experimental data on total, elastic and diffractive cross sections. In addition we calculate the survival probability for a SM Higgs at the LHC, and compare our results with those of the Durham group.Comment: 7 pages, 4 figures, talk at 13th International Confernce on Elastic and Diffractive Scattering, CERN, 29th June - 3rd July 200

    Genotyping of human and animal isolates of Giardia intestinalis : a thesis presented in partial fulfilment of the requirements for the degree of Master of Science in Microbiology at Massey University

    Get PDF
    Giardia intestinalis is an important protozoan parasite that infects humans and animals. It has been suggested that cattle may be a major source of human Giardia infection so a dairy farming region of New Zealand was investigated. This thesis uses three molecular methods to genotype G. intestinalis isolates obtained from human and animal faecal specimens collected in the Waikato region of New Zealand, to determine if giardiasis is a zoonotic disease. Random amplification of polymorphic DNA (RAPD) and amplified fragment length polymorphism (AFLP) fingerprinting techniques were initially assessed for their ability to genotype G. intestinalis isolates. "Clear cut" evidence of zoonosis could not be established by either method, due to a low sample number. To determine the stability of the G. intestinalis genome an axenic culture of G. intestinalis trophozoites was stressed with toxic levels of metronidazole and the survivors, following a number of passages, were examined using AFLP and RAPD analysis. The DNA fingerprints were compared to those of the original wild-type with the results being indicative of an unstable G. intestinalis genome. A third molecular method was employed, which amplifies a portion of the tandemly repeated ribosomal DNA (rDNA). Each cyst contains 512 head to tail tandem repeat copies of the rRNA gene made up of both conserved and variable regions. The use of nested primers increased the sensitivity and specificity of the PCR reaction allowing the amplification of a 505bp rDNA fragment. DNA sequence analysis and alignment of the amplified products facilitated the comparison of G. intestinalis isolates. The relationship of the sequence data was generated and displayed using Splitstree software indicating that zoonosis did occur

    Heat recovery refrigeration in New Zealand dairy sheds : a thesis presented in partial fulfilment of the requirements for the degree of Master of Agricultural Science in Agricultural Engineering at Massey University

    Get PDF
    Increased energy costs initiated an investigation into refrigeration heat recovery as one conservation alternative available for reducing water heating costs on farm dairies. A theoretical energy balance was conducted, from which the potential of recovering refrigeration condenser heat was estimated at up to 60% of the water heating energy requirements. Preliminary tests with heat exchangers lead to the use of a tube-in-tube, counter flow, heat exchanger with fins on the refrigerant side, and cores on the water side, to improve the heat transfer characteristics. The exchanger, designed to provide 300 litres of 60°C water from a 2.25 kw refrigeration system cooling 2000 litres of milk per day, had an area of 0.84 m2, and an overall thermal conductance of 100 W.m-2.°C-1. This heat exchanger was inserted between the compressor and condenser of the refrigeration plant and tested with two condenser systems (air and water), four condenser pressures (6.5 bar, 7.5 bar, 10 bar and 12 bar), two milk inlet temperatures(23°C and l8°C), and two milk final temperatures (4°C and 7°C). In addition, tests on receiver pressure and suction superheat were performed to determine overall system performance. Increasing condenser pressure increased cooling times from 2 hours 32 minutes to 3 hours 17 minutes, after the completion of the 1200 litre morning milking (thus failing to comply with the 3 hour cooling regulation at high condenser pressures.) Also, C.O.P. decreased from 3.05 to 2.35 for the water cooled condenser system (2.70 to 2.00 for the air cooled condenser system due to fan power consumption). Gross heat recovery rose from 4.2 kWh.day-1 .m-3 to 8.l kWh.day-1 .m-3 for the water cooled system, giving water outlet temperatures of 45°C to 64°C as condenser pressure rose. The corresponding ranges for air cooled condensers were 3.8 kWh.day-1 .m-3, to 6.6 kWh .day-1 .m-3, and 38°C to 55°C. Changing milk inlet and final temperatures gave a proportional change in cooling times and total heat recovery, but had no effect on C.O.P. or heat recovery rates. Suction superheating increased total heat recovery by 15%, and water outlet temperatures by 9%. Increases in gross heat recovery with increasing condenser pressure were partially offset by additional compressor power, and yielded nett heat recoveries of 4.0 kWh.day-1 .m-3 to 6.0 kWh.day-1 .m-3 for water cooled, and 3.6 kWh. day-1 .m-3 to 4.3 kWh. day-1 .m-3 for air cooled, condenser systems. The maximum gross and nett heat recoveries (at 12 bar condenser pressure) were applied to the energy requirements of a monitored 220 cow town supply dairy. This analysis showed that the gross heat recovery was 51% of the water heating requirements, but the nett heat recovery dropped to 17% of the total heating and refrigeration demand. Based on current electricity and equipment prices, it is estimated that the payback period for this level of recovery would be 16-17 years. Changing the electricity pricing structure, to reflect up to a 1:3 differential in favour of water heating power costs, results in the 6.5 bar condenser pressure giving optimum results, but the nett returns are significantly lower than those reported. The potential for improved savings is greater from larger capacity systems as the capital investment is not proportionally increased with an increase in scale

    Creating Responsive Information Systems with the Help of SSADM

    Get PDF
    In this paper, a program for a research is outlined. Firstly, the concept of responsive information systems is defined and then the notion of the capacity planning and software performance engineering is clarified. Secondly, the purpose of the proposed methodology of capacity planning, the interface to information systems analysis and development methodologies (SSADM), the advantage of knowledge-based approach is discussed. The interfaces to CASE tools more precisely to data dictionaries or repositories (IRDS) are examined in the context of a certain systems analysis and design methodology (e.g. SSADM)

    Prime Time (for the Basing Relation)

    Get PDF
    It is often assumed that believing that p for a normative reason consists in nothing more than (i) believing that p for a reason and (ii) that reason’s corresponding to a normative reason to believe that p, where (i) and (ii) are independent factors. This is the Composite View. In this paper, we argue against the Composite View on extensional and theoretical grounds. We advocate an alternative that we call the Prime View. On this view, believing for a normative reason is a distinctive achievement that isn’t exhausted by the mere conjunction of (i) and (ii). Its being an achievement entails that (i) and (ii) are not independent when one believes for a normative reason: minimally, (i) must hold because (ii) holds. Apart from its intrinsic interest, our discussion has important upshots for central issues in epistemology, including the analysis of doxastic justification, the epistemology of perception, and the place of competence in epistemology

    Reasons: Wrong, Right, Normative, Fundamental

    Get PDF
    Reasons fundamentalists maintain that we can analyze all derivative normative properties in terms of normative reasons. These theorists famously encounter the Wrong Kind of Reasons problem, since not all reasons for reactions seem relevant for reasons-based analyses. Some have argued that this problem is a general one for many theorists, and claim that this lightens the burden for reasons fundamentalists. We argue in this paper that the reverse is true: the generality of the problem makes life harder for reasons fundamentalists. We do this in two stages. First, we show that reflection on the generality of the distinction between wrong-kind reasons and right-kind reasons shows that not all right-kind reasons are normative reasons. So, not only do reasons-based analyses require a distinction between right-kind reasons and wrong-kind reasons, they also need a distinction between normative right-kind reasons from nonnormative right-kind reasons. We call this the Right Kind of Reasons Problem. In the second stage of the paper, we argue that reasons fundamentalism places tight constraints on its proper solution: in particular, it forbids one from appealing to anything normative to distinguish normative RKRs from nonnormative RKRs. It hence seems that reasons fundamentalists can only appeal to natural facts to solve the problem, but it is unclear which ones can do the job. So, reflection on the generality of the distinction only multiplies the fundamentalist’s problems. We end by exploring several solutions to these problems, and recommend a form of constitutivism as the best

    Development of Bus-Stop Time Models in Dense Urban Areas: A Case Study in Washington DC

    Get PDF
    Bus transit reliability depends on several factors including the route of travel, traffic conditions, time of day, and conditions at the bus stops along the route. The number of passengers alighting or boarding, fare payment method, dwell time (DT), and the location of the bus stop also affect the overall reliability of bus transit service. This study defines a new variable, Total Bus Stop Time (TBST) which includes DT and the time it takes a bus to safely maneuver into a bus stop and the re-entering the main traffic stream. It is thought that, if the TBST is minimized at bus stops, the overall reliability of bus transit along routes could be improved. This study focused on developing a TBST model for bus stops located near intersections and at mid-blocks using ordinary least squares method based on data collection at 60 bus stops, 30 of which were near intersections while the remaining were at mid-blocks in Washington DC. The field data collection was conducted during the morning, mid-day, and evening peak hours. The following variables were observed at each bus stop: bus stop type, number of passengers alighting or boarding, DT, TBST, number of lanes on approach to the bus stop, presence of parking, and bus pad length. The data was analyzed and all statistical inferences were conducted based on 95% confidence interval. The results show that the TBST could be used to aid in improving planning and scheduling of transit bus systems in an urban area

    Investigating the role of central nutrient-sensing neurones using adeno-associated viral manipulation of glucokinase

    No full text
    The primary aim of the work described in this thesis was to investigate the physiological role of glucose sensing neurones within the arcuate nucleus of the hypothalamus (ARC). To this end, recombinant adeno-associated virus encoding glucokinase (rAAV-GKS) was delivered to the ARC of adult male Wistar rats. Glucokinase (GK) catalyses the first reaction in glycolysis and has been hypothesised to act as a regulator of hypothalamic glucose sensing. Furthermore, manipulation of GK has been shown to alter the sensitivity of glucose sensing neurones in vitro. I hypothesised that increasing GK expression in the ARC using rAAV-GKS would influence the sensitivity of glucose sensing neurones in vivo and provide insight into their physiological role. Bilateral administration of rAAV-GKS to the ARC resulted in a 14-fold increase in hypothalamic GK mRNA expression compared to controls. Food intake and body weight gain were significantly increased in rAAV-GKS treated rats compared to controls on standard chow. The increased body weight of the rAAV-GKS group was attributed to a significant increase in adipose tissue with no difference in lean mass. Food intake and body weight gain were also significantly increased in rAAV-GKS treated animals maintained on a high calorie “western-style” diet. Despite their increased adiposity, rAAV-GKS treated rats displayed significantly improved glucose tolerance compared to controls. The increased glucose tolerance of the rAAV-GKS group was associated with increased glucose-stimulated insulin secretion. rAAV-GKS treated rats consumed a significantly greater volume of a 10% glucose solution compared to controls over a 16 hour period. In addition, rAAV-GKS animals showed a clear preference for glucose over standard chow compared to controls over 24 hours and during a 31 day longitudinal study. The results of this work suggest that glucose sensing neurones in the ARC may be involved in the regulation of energy balance and glucose homeostasis. These results are of broader significance considering the proposed use of GK activating drugs in the treatment of type II diabetes mellitus

    Design methodologies for controlling vibrations in buildings

    Get PDF
    Thesis (M.Eng.)--Massachusetts Institute of Technology, Dept. of Civil and Environmental Engineering, 1999.Includes bibliographical references (leaves 44-45).Although vibration absorbers have been employed in mechanical equipment mounting for over 100 years, they have only recently been used for isolating large-scale structures such as bridges and buildings. Their applications range from acoustic to seismic isolation of structures. Virtually any vibration magnitude can be prevented from degrading the performance of a structure. This thesis is intended to provide a practical introduction to the design and suitability of vibration isolators for various environments. It contains a discussion of the past, present and future of vibration isolation associated with buildings. Analysis and design examples are provided to illustrate the design methodology.by Errol Laub.M.Eng

    Urban agriculture as an integral part of urban growth management strategies and the implications on urban form policy: the case of Auckland NZ

    Get PDF
    Urban agriculture potential is examined in three suburbs of increasing density in Auckland, NZ. A review of the relationship between urban indicators (net density and housing patterns) and potential solar energy available at ground level is done. Since soils are generally fertile and water readily available solar access to ground level becomes an indicator of productivity. Using the subtraction method and satellite photography from Auckland council GIS viewer, potentially productive land is estimated in three residential blocks-Mt Eden, Sandrigham and New Lynn. Based on the results the food energy potential of each site is determined. Preliminary results indicate that low density New Lynn has the highest potential for sustainability with surplus food energy. Medium density Sandrigham could meet 50 per cent of its vegetable dietary requirement while high density Mt Eden is unsustainable in UA. Recommendations are suggested as to how UA maybe integrated in urban growth strategies
    • …
    corecore