Structural analysis of silicon solar arrays

Engineering mechanics in structural design of silicon solar array

Further investigation of whether correlations amongst data are invalidating the conclusion of a statistically significant trend in Antarctic minke body condition over time

A statistically significant decline in body condition in the Antarctic minke whale over the JARPA period was reported in Konishi et al. (2008). Subsequently, however, questions were raised in the IWC Scientific Committee as to whether the model used had adequately accounted for the data structure in JARPA (de la Mare, 2011), i.e. whether neglect of correlations in the data had led to negative bias in the confidence interval estimated for the decline. Earlier a jack-knife approach with year as the sampling unit was used to account for within-year correlations, and showed that while the confidence interval estimates reported originally had been negatively biased, the estimated decline remained statistically significant at the 5% level. This approach did not, however, take account of possible betweenyear correlations. This paper investigates the possibility that such correlations could have biased these interval estimates appreciably. The results show no sign of appreciable interannual auto-correlation, and indicate that the decline reported by Konishi et al. (2008) remains statistically significant at the 5% level. We suggest that his constitutes sufficient statistical evidence to confirm this significance, so that this matter might now be regarded as resolved by the Scientific Committee

Search for the Elusive Higgs Boson Using Jet Structure at LHC

We consider the production of a light non-standard model Higgs boson of order 100~\GEV with an associated $W$ boson at CERN Large Hadron Collider. We focus on an interesting scenario that, the Higgs boson decays predominately into two light scalars $\chi$ with mass of few GeV which sequently decay into four gluons, i.e. $h\to 2\chi \to 4g$. Since $\chi$ is much lighter than the Higgs boson, it will be highly boosted and its decay products, the two gluons, will move close to each other, resulting in a single jet for $\chi$ decay in the detector. By using electromagnetic calorimeter-based and jet substructure analyses, we show in two cases of different $\chi$ masses that it is quite promising to extract the signal of Higgs boson out of large QCD background.Comment: 20 pages, 7 figure

A flexible model for dimensioning mixed service 3G wireless networks

In this paper we present an approximate closed form solution for dimensioning mixed service 3G wireless networks for defined service and quality constraints. Both web-browsing services alone, as well as a mixture of web and circuit voice services are considered. Dimensioning is achieved through knowledge of the distribution of the latency delay experienced by end users of the 3G network. The parameters defining the distribution are shown to be dependent on a range of network and service parameters. This allows the dimensioning of 3G wireless networks under a wide range of quality and service conditions

Maximal mass of uniformly rotating homogeneous stars in Einsteinian gravity

Using a multi domain spectral method, we investigate systematically the general-relativistic model for axisymmetric uniformly rotating, homogeneous fluid bodies generalizing the analytically known Maclaurin and Schwarzschild solutions. Apart from the curves associated with these solutions and a further curve of configurations that rotate at the mass shedding limit, two more curves are found to border the corresponding two parameter set of solutions. One of them is a Newtonian lens shaped sequence bifurcating from the Maclaurin spheroid sequence, while the other one corresponds to highly relativistic bodies with an infinite central pressure. The properties of the configuration for which both the gravitational and the baryonic masses, moreover angular velocity, angular momentum as well as polar red shift obtain their maximal values are discussed in detail. In particular, by comparison with the static Schwarzschild solution, we obtain an increase of 34.25% in the gravitational mass. Moreover, we provide exemplarily a discussion of angular velocity and gravitational mass on the entire solution class.Comment: 4 pages, 4 figures, 1 table, submitted to A&A, corrected eq. for W, W' in 3.

Productive uses of domestic water: opportunity or threat?

This paper argues that small-scale productive uses of water such as for garden irrigation, keeping livestock, post-harvest crop processing and other micro-enterprises should receive better consideration in the planning of domestic water supply systems. Currently opportunities are being lost to maximize the impacts on poverty alleviation of improvements in water supply, and sustainability is undermined by failing to address the productive needs of users. An agenda for possible policy change, implementation actions and further research is included based upon the outcomes of an earlier international symposium

Prostate cancer radiotherapy: potential applications of metal nanoparticles for imaging and therapy

Prostate cancer (CaP) is the most commonly diagnosed cancer in males. There have been dramatic technical advances in radiotherapy delivery, enabling higher doses of radiotherapy to primary cancer, involved lymph nodes and oligometastases with acceptable normal tissue toxicity. Despite this, many patients relapse following primary radical therapy, and novel treatment approaches are required. Metal nanoparticles are agents that promise to improve diagnostic imaging and image-guided radiotherapy and to selectively enhance radiotherapy effectiveness in CaP. We summarize current radiotherapy treatment approaches for CaP and consider pre-clinical and clinical evidence for metal nanoparticles in this condition

Diboson-Jets and the Search for Resonant Zh Production

New particles at the TeV-scale may have sizeable decay rates into boosted Higgs bosons or other heavy scalars. Here, we investigate the possibility of identifying such processes when the Higgs/scalar subsequently decays into a pair of W bosons, constituting a highly distinctive "diboson-jet." These can appear as a simple dilepton (plus MET) configuration, as a two-prong jet with an embedded lepton, or as a four-prong jet. We study jet substructure methods to discriminate these objects from their dominant backgrounds. We then demonstrate the use of these techniques in the search for a heavy spin-one Z' boson, such as may arise from strong dynamics or an extended gauge sector, utilizing the decay chain Z' -> Zh -> Z(WW^(*)). We find that modes with multiple boosted hadronic Zs and Ws tend to offer the best prospects for the highest accessible masses. For 100/fb luminosity at the 14 TeV LHC, Z' decays into a standard 125 GeV Higgs can be observed with 5-sigma significance for masses of 1.5-2.5 TeV for a range of models. For a 200 GeV Higgs (requiring nonstandard couplings, such as fermiophobic), the reach may improve to up to 2.5-3.0 TeV.Comment: 23 pages plus appendices, 9 figure

QCD and Hadron Dynamics

Perturbative QCD predicts and describes various features of multihadron production. An amazing similarity between observable hadron systems and calculable underlying parton ensembles justifies the attempts to use the language of quarks and gluons down to small momentum scales, to approach the profound problems that are commonly viewed as being entirely non-perturbative.Comment: Talk at the Royal Society meeting "Structure of Matter", London, May 200

Productivity and profitability of cattle stall-fed for beef on smallholder farms in Malawi

Presents the results of biological and financial analyses performed on the productivity and profitability of cattle stall-fed for beef on smallholder farms in Malawi