cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Assessment of Improvement Areas for Increasing the Capacity of Ethio-Djibouti Railway Line
Creators: name: Yohannes, Melkamu
Publisher: name: National Academic Digital Repository of Ethiopia
Year: 2018

description: Ethio-Djibouti railway line can support the economic growth of the country by allowing transportation of more goods than now, reduce greenhouse gas emission (environmental friendly), reduce road congestion, allows the country to increase the variety of export goods. This research aims to analyze the capacity issues of Ethio-Djibouti railway line and identify and assess possible capacity improvement areas to satisfy the railway transport demand of Ethiopia for the coming 50years time period. To attain the objective of the research firstly practical capacity of the existing EthioDjibouti railway line is done by UIC405 analytical method; secondly railway transportation demand for both freight and passenger is assessed along the corridor; it"s obvious that the capacity of the existing railway will saturate in the future, the saturation year is identified by comparing the practical capacity of Ethio-Djibouti railway line with railway transportation demand analysis done along the corridor. Finally possible capacity expansion plan mainly infrastructure improvement is identified in this research. The single track section of Ethio-Djibouti railway practically can accommodate 33 trains/day. The section from Dire Dawa to Negad starting from 2030GC; the section from Awash to DireDawa starting from 2036GC and the section from Adama to Awash starting from 2037GC will become saturated and needed capacity improvement. To satisfy the increasing railway transportation demand along Ethio-Djibouti railway line increasing the number of trains operating on the line can be the solution; but the sections infrastructure capacity wouldn"t allow to add more trains in the saturation years. Therefore, in 2030GC the single track railway from DireDawa to Djibouti; in the year of 2036GC the section from Awash to Dire Dawa and in the year of 2037 GC the railway line section from Adama to Awash should have to be changed to double track in order to fulfill the demand. The double track section from Sebeta to Adama can practically accommodate 64 trains/day but the demand analysis shows that starting from 2059GC the line will become saturated in this case infrastructure expansion is not necessary because it can satisfy the demand on the specified time window.
The Hydration Structure of Carbon Monoxide by Ab Initio Methods
Creators: name: Awoonor-Williams, Ernest
name: Rowley, Christopher N.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Chemical Physics (physics.chem-ph)
subject: FOS: Physical sciences

description: The solvation of carbon monoxide (CO) in liquid water is important for understanding its toxicological effects and biochemical roles. In this paper, we use ab initio molecular dynamics (AIMD) and CCSD(T)-F12 calculations to assess the accuracy of the Straub and Karplus molecular mechanical (MM) model for CO(aq). The CCSD(T)-F12 CO--H2O potential energy surfaces show that the most stable structure corresponds to water donating a hydrogen bond to the C center. The MM-calculated surface it incorrectly predicts that the O atom is a stronger hydrogen bond acceptor than the C atom. The AIMD simulations indicate that CO is solvated like a hydrophobic solute, with very limited hydrogen bonding with water. The MM model tends to overestimate the degree of hydrogen bonding and overestimates the atomic radius of the C atom. The calculated Gibbs energy of hydration is in good agreement with experiment (9.3 kJ/mol calc. vs 10.7 kJ/mol exptl.). The calculated diffusivity of CO(aq) in TIP3P-model water was 5.19 x 10-5 cm2/s calc., more than double the experimental value of 2.32 x 10-5 cm2/s
A fuzzy-based approach to strategic bidding in competitive electricity markets
Creators: name: Widjaja., Moeljono
Publisher: name: Monash University
Year: 2021

description: This thesis was scanned from the print manuscript for digital preservation and is copyright the author.
 Researchers can access this thesis by asking their local university, institution or public library to
 make a request on their behalf. Monash staff and postgraduate students can use the link in the References field.
Mass Exit Attacks on the Lightning Network
Creators: name: Sguanci, Cosimo
Publisher: name: University of Illinois at Chicago
Year: 2023

description: The Lightning Network (LN) is currently the most popular scaling solution for the Bitcoin blockchain, consisting of payment channels between nodes holding different amounts of BTC. The security of the LN relies on the ability of honest users to close a channel in case of fraudulent behavior by settling their balances, which requires having a transaction confirmed on the Bitcoin blockchain within a pre-agreed time period. We study the susceptibility of the LN to attacks that seek to exploit periods of high congestion on the Bitcoin blockchain and the consequent delay in confirming LN users' transactions. In this scenario, a small coalition of adversarial nodes forces a large set of honest protocol participants to interact with the blockchain: we formulate the problem of finding a worst-case coalition of k adversarial nodes as a graph max-cut problem. We focus on two types of attacks. In the first one, a set of k nodes becomes unresponsive with the goal of locking the funds of many channels for a period of time longer than required by the LN protocol. In the second type of attack, a coalition of k nodes attempts to steal funds by submitting many closing transactions that settle channels using expired channel states. We perform our analysis via simulations that make use of historical data about unconfirmed transactions in the Bitcoin mempool, in periods of high congestion of the blockchain. We show that, under historically-plausible congestion conditions, both attacks can be carried out by a small coalition. These findings highlight the importance of watchtower services, which monitor channels to detect channel breaches and react accordingly: these services must adopt sophisticated strategies to avoid the loss of users' funds.
The nature of the light variability of magnetic Of?p star HD 191612
Creators: name: Krticka, J.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: A small fraction of hot OBA stars host global magnetic fields with field strengths of the order of 0.1-10 kG. This leads to the creation of persistent surface structures (spots) in stars with sufficiently weak winds as a result of the radiative diffusion. These spots become evident in spectroscopic and photometric variability. This type of variability is not expected in stars with strong winds, where the wind inhibits the radiative diffusion. Therefore, a weak photometric variability of the magnetic Of?p star HD 191612 is attributed to the light absorption in the circumstellar clouds. We study the nature of the photometric variability of HD 191612. We assume that the variability results from variable wind blanketing induced by surface variations of the magnetic field tilt and modulated by stellar rotation. We used our global kinetic equilibrium (NLTE) wind models with radiative force determined from the radiative transfer equation in the comoving frame (CMF) to predict the stellar emergent flux. Our models describe the stellar atmosphere in a unified manner and account for the influence of the wind on the atmosphere. The models are calculated for different wind mass-loss rates to mimic the effect of magnetic field tilt on the emergent fluxes. We integrate the emergent fluxes over the visible stellar surface for individual rotational phases, and calculate the rotationally modulated light curve of HD 191612. The wind blanketing that varies across surface is able to explain a part of the observed light variability in this star. The mechanism is able to operate even at relatively low mass-loss rates. The remaining variability is most likely caused by the flux absorption in circumstellar clouds. The variable wind blanketing is an additional source of the light variability in massive stars. The presence of the rotational light variability may serve as a proxy for the magnetic field.
description: 5 pages, accepted for publication in A&A
Assessing the implementation of physical activity-promoting public policies in the Republic of Ireland: a study using the Physical Activity Environment Policy Index (PA-EPI)
Creators: name: VOLF, KEVIN
name: Kelly, Liam
name: van Hoye, Aurelie
name: Garcia Bengoechea, Enrique
name: Mac Phail, Ann
name: WOODS, CATHERINE
Publisher: name: University of Limerick
Year: 2023
Subjects: subject: Health sciences
subject: FOS: Health sciences
subject: Sports science and exercise

description: Background Government policy can promote physical activity (PA) as part of a multilevel systems-based approach. The Physical Activity Environment Policy Index (PA-EPI) is a monitoring framework which assesses the implementation of government policy by drawing on the experience of national stakeholders. This study is the frst to assess the extent of policy implementation in the Republic of Ireland using the PA-EPI tool, and to provide information on how policy implementation can be improved, with the intention of maximizing its impact on population levels of PA. Methods This mixed-methods research study, comprising eight steps, was carried out in 2022. Information documenting the evidence for implementation of PA policy, across all 45 PA-EPI indicators, was collected via systematic document analysis, and validated via survey and interview with government ofcials. Thirty-two nongovernment stakeholders rated this evidence on a fve-point Likert scale. Aggregated scores were reviewed by stakeholders who collectively identifed and prioritized critical implementation gaps. Results Of the 45 PA-EPI indicators, one received an implementation rating of ‘none/very little’, 25 received a rating of ‘low’ and 19 received a ‘medium’ rating. No indicator was rated as fully implemented. The indicators that received the highest level of implementation related to sustained mass media campaigns promoting PA and PA monitoring. Ten priority recommendations were developed. Conclusions This study reveals substantial implementation gaps for PA policy in the Republic of Ireland. It provides recommendations for policy action to address these gaps. In time, studies utilizing the PA-EPI will enable cross-country comparison and benchmarking of PA policy implementation, incentivizing improved PA policy creation and implementation.
Bayesian Evolution Models for Jupiter with Helium Rain and Double-diffusive Convection
Creators: name: Mankovich, Christopher
name: Fortney, Jonathan J.
name: Moore, Kevin L.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: FOS: Physical sciences

description: Hydrogen and helium demix when sufficiently cool, and this bears on the evolution of all giant planets at large separations at or below roughly a Jupiter mass. We model the thermal evolution of Jupiter, including its evolving helium distribution following results of ab initio simulations for helium immiscibility in metallic hydrogen. After 4 Gyr of homogeneous evolution, differentiation establishes a thin helium gradient below 1 Mbar that dynamically stabilizes the fluid to convection. The region undergoes overstable double-diffusive convection (ODDC), whose weak heat transport maintains a superadiabatic temperature gradient. With a generic parameterization for the ODDC efficiency, the models can reconcile Jupiter's intrinsic flux, atmospheric helium content, and radius at the age of the solar system if the Lorenzen et al. H-He phase diagram is translated to lower temperatures. We cast the evolutionary models in an MCMC framework to explore tens of thousands of evolutionary sequences, retrieving probability distributions for the total heavy element mass, the superadiabaticity of the temperature gradient due to ODDC, and the phase diagram perturbation. The adopted SCvH-I equation of state favors inefficient ODDC such that a thermal boundary layer is formed, allowing the molecular envelope to cool rapidly while the deeper interior actually heats up over time. If the overall cooling time is modulated with an additional free parameter to imitate the effect of a colder or warmer EOS, the models favor those that are colder than SCvH-I. In this case the superadiabaticity is modest and a warming or cooling deep interior are equally likely.
description: 13 pages, 12 figures, accepted for publication in ApJ
Newsletter 4. CHESS SETUP getting bigger
Creators: name: Edenway
Publisher: name: Zenodo
Year: 2018
Subjects: subject: newsletter
subject: https://shoutout.wix.com/so/9MGtLKoU#/main

description: CHESS SETUP: STEP 4 CHESS SETUP getting bigger and brighter Welcome to our 4th newsletter, we wish you a pleasant reading
Low velocity impact of composite aerospace structures under prestress
Creators: name: Whittingham., Brendan Owen
Publisher: name: Monash University
Year: 2021

description: This thesis was scanned from the print manuscript for digital preservation and is copyright the author.
 Researchers can access this thesis by asking their local university, institution or public library to
 make a request on their behalf. Monash staff and postgraduate students can use the link in the References field.
The Zeeman Effect in the 44 GHz Class I Methanol Maser Line toward DR21(OH)
Creators: name: Momjian, E.
name: Sarma, A. P.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: We report the detection of the Zeeman effect in the 44 GHz Class I methanol maser line toward the star forming region DR21(OH). In a 219 Jy/beam maser centered at an LSR velocity of 0.83 km s$^{-1}$, we find a 20-$σ$ detection of $zB_{\text{los}} = 53.5 \pm 2.7$ Hz. If 44 GHz methanol masers are excited at $n \sim 10^{7-8}$ cm$^{-3}$, then the $B~vs.~n^{1/2}$ relation would imply from comparison with Zeeman effect detections in the CN($1-0$) line toward DR21(OH) that magnetic fields traced by 44 GHz methanol masers in DR21(OH) should be $\sim$10 mG. Together with our detected $zB_{\text{los}} = 53.5$ Hz, this would imply that the value of the 44 GHz methanol Zeeman splitting factor $z$ is $\sim$5 Hz mG$^{-1}$. Such small values of $z$ would not be a surprise, as the methanol molecule is non paramagnetic, like H$_2$O. Empirical attempts to determine $z$, as demonstrated, are important because currently there are no laboratory measurements or theoretically calculated values of $z$ for the 44 GHz methanol transition. Data from observations of a larger number of sources are needed to make such empirical determinations robust.
description: 11 pages, 3 figures, accepted for publication in ApJ
Erratum for "Axion Dark Matter Coupling to Resonant Photons via Magnetic Field" [arXiv:1512.05547]
Creators: name: McAllister, Ben T.
name: Parker, Stephen R.
name: Tobar, Michael E.
Publisher: name: arXiv
Year: 2016
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: A recent comment highlights a discussion at the PATRAS Workshop on Axions, WIMPs and WISPs relating to a recent publication. We respond to this comment, and detail a calculation error in the original letter.
description: 2 pages, 1 figure
Optimization of Brake Disc Thickness and Radius Using Different Disc Brake Materials by FEM
Creators: name: Aden, Egueh
Publisher: name: National Academic Digital Repository of Ethiopia
Year: 2017

description: The main purpose of this study is the optimization of disc brake materials by changing the radius and the thickness of the disc using different materials to choose the optimum disc brake material. The modelling of disc brake is made in CATIA software, the thermal and structure analysis is done using ANSYS workbench. In this research, a transient thermal and structural analysis was carried out to investigate the temperature variation across the disc and the total heat flux using ANSYS software. The thermal-structural analysis is then used to determine the deformation established and stresses in the disc. In all cases when the dimensions of disc model increase temperature, deformation and equivalent stress decrease. For example the deformation of cast iron decreases 7.0616e-5m to 5.4009e-5m when we change the model. For the side of the material by varying the properties of the materials, the better material for this study is the aluminium alloys 7075 with silicon carbide SiC/AL7075 because it has the minimum deformation 3.6367e-5 for model3. Finally this thesis suggests the SiC/AL7075 to be used disc brake material for the future with the model3.
GraDD: A Graph Machine Learning and Natural Language Processing Approach to Automatic Dementia Detection
Creators: name: Stoppa, Edoardo
Publisher: name: University of Illinois at Chicago
Year: 2023

description: Alzheimer's Disease is a progressive neurodegenerative disease that has no cure, with a lengthy and costly diagnosis process. One of the earliest signs of Dementia is difficulty in producing language, and that is why Computer-Aided Dementia Detection through Natural Language Processing is emerging as a viable solution for an early diagnosis. Our work makes three main contributions. First, we have developed a framework used for the extraction of manually engineered features from dementia-related audio files and transcripts. The framework is open-source and easily extensible, making it possible for other researchers to contribute by adding new features or new groups of features. Second, we have built a machine learning performance evaluation framework that standardizes the entire performance analysis process. Last, we propose a new approach to Automatic Dementia Detection, based on Graph Machine Learning. We demonstrate that the method is promising given the encouraging results, even if it's still far from the current state-of-the-art performance.
Proteo-metabolomics and patient tumor slice functional studies point to the centrality of amino acids for re-wired mitochondria in fibrolamellar carcinoma
Creators: name: Donald Long Jr., Don Long
Publisher: name: Zenodo
Year: 2024
Subjects: Machine Learning
Concordance Analysis
Correlation Analysis
Differential Protein Expression
Proteomics
Metabolomics
Data Imputation
Data processing
Figure Generation

description: The uploaded folders contain (1) scripts for performing core analyses detailed in our manuscript, (2) scripts for generating all of the main figures in our manuscript, and (3) data that serves as input for the scripts. Be sure to create a folder entitled "the_results" in your present working directory after download.
description: Fibrolamellar carcinoma (FLC) is a rare, early-onset liver cancer.  The five-year survival rate is low, and there is a critical need for new therapeutics.  The primary driver in FLC is the fusion oncoprotein, DNAJ-PKAc, which remains challenging to target therapeutically.  It is critical, therefore, to expand understanding of the FLC molecular landscape to identify druggable pathways/targets. We have performed the most comprehensive characterization of FLC in both proteomics (n = 23 patient samples; n = 8485 proteins) and metabolomics (n = 26 patient samples; n = 135 metabolites). Additionally, we have conducted respirometry analyses as well as RNAi- and small molecule inhibitor-mediated loss of function assays in FLC tumor tissue slices from patients.  We propose a model of cellular energetics in FLC that centers on amino acids.  Our model points to proline anabolism that is very likely mediated by ornithine aminotransferase hyperactivity and ornithine transcarbamylase hypoactivity with serine and glutamine catabolism fueling the process. We also highlight a dependency of FLC tumors on VDAC, which functions as a gatekeeper for mitochondrial metabolites including pyruvate. The metabolic rewiring in FLC proposed by our model, with a particular emphasis on mitochondria, can be exploited for therapeutic vulnerabilities.
Loop corrections to pion and kaon neutrinoproduction
Creators: name: Siddikov, Marat
name: Schmidt, Ivan
Publisher: name: arXiv
Year: 2016
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: High Energy Physics - Experiment (hep-ex)
subject: FOS: Physical sciences

description: In this paper we study the next-to-leading order corrections to deeply virtual pion and kaon production in neutrino experiments. We estimate these corrections in the kinematics of the Minerva experiment at FERMILAB, and find that they are sizable and increase the leading order cross-section by up to a factor of two. We provide a code, which can be used for the evaluation of the cross-sections, taking into account these corrections and employing various GPD models.
description: 11 pages, 5 figures. Next-to-leading order corrections to the approach suggested in our earlier arXiv:1210.4825, arXiv:1301.7014 and arXiv:1401.1547
Performance and Energy Management for Multi-Hop Traffic in Wireless Sensor Networks (WSNS) Towards Railway Track Failure Monitoring Application
Creators: name: Fantaye, Haileyesus
Publisher: name: National Academic Digital Repository of Ethiopia
Year: 2015

description: Wireless Sensor Network (WSN) is an innovative ad-hoc network with distributed sensing and processing capacities made up of collection of sensor nodes. The sensors transmit information to the sink. The routing protocols for WSNs are based mostly on efficiency of energy and some deal with real-time requirements. In this paper, a comparative study between Low Energy Adaptive Clustering Hierarchy (LEACH), Stable Election Protocol (SEP) and Hierarchical Adaptive Balanced energy-efficient Routing Protocol (HABRP) would be conducted being heterogeneous sensors are employed in order to attain an energy-efficient routing protocol in the sensor network field. The paper typically discusses an energy management of routing protocol in order to attain the safety analysis of a railway track monitoring. A sensor network in mesh topology has been used to detect the cracks with incorporated camera embedded along the railway track for proper end-to-end data delivery with minimum communication energy. The simulation has been done by MATLAB software environment. On the design process of railway track failure monitoring our desired routing protocol HABRP satisfies an improvement compared with LEACH by 76%.This system furnishes a cheap, reliable, flexible, and intellectual alternative for the existing system.
Using 21-cm absorption surveys to measure the average HI spin temperature in distant galaxies
Creators: name: Allison, J. R.
name: Zwaan, M. A.
name: Duchesne, S. W.
name: Curran, S. J.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: We present a statistical method for measuring the average HI spin temperature in distant galaxies using the expected detection yields from future wide-field 21cm absorption surveys. As a demonstrative case study we consider a simulated all-southern-sky survey of 2-h per pointing with the Australian Square Kilometre Array Pathfinder for intervening HI absorbers at intermediate cosmological redshifts between $z = 0.4$ and $1$. For example, if such a survey yielded $1000$ absorbers we would infer a harmonic-mean spin temperature of $\overline{T}_\mathrm{spin} \sim 100$K for the population of damped Lyman $α$ (DLAs) absorbers at these redshifts, indicating that more than $50$ per cent of the neutral gas in these systems is in a cold neutral medium (CNM). Conversely, a lower yield of only 100 detections would imply $\overline{T}_\mathrm{spin} \sim 1000$K and a CNM fraction less than $10$ per cent. We propose that this method can be used to provide independent verification of the spin temperature evolution reported in recent 21cm surveys of known DLAs at high redshift and for measuring the spin temperature at intermediate redshifts below $z \approx 1.7$, where the Lyman-$α$ line is inaccessible using ground-based observatories. Increasingly more sensitive and larger surveys with the Square Kilometre Array should provide stronger statistical constraints on the average spin temperature. However, these will ultimately be limited by the accuracy to which we can determine the HI column density frequency distribution, the covering factor and the redshift distribution of the background radio source population.
description: 11 pages, 9 figures, 1 table. Proof corrected version
Thermally Polarized 129Xe Phantom for MR Imaging and Elastography in 9.4T MRI
Creators: name: Canavesi, Irene
Publisher: name: University of Illinois at Chicago
Year: 2023

description: Respiratory diseases account for three of the top ten causes of death worldwide, causing more than 8 million deaths per year. One of the ways to tackle the problem is the improvement of early-diagnostic techniques: it can be accomplished first by meeting the demand for high quality images of the lungs’ airways to identify airspace obstructions and secondly, addressing the need for quantifying mechanical properties of the lung parenchyma, whose changes are often associated with disabling lung diseases. Magnetic resonance imaging with hyperpolarized 129Xe gas is a promising non-invasive imaging technique for high-resolution airspace imaging, and 129Xe magnetic resonance elastography (MRE) could be an interesting technique for estimating lung parenchyma mechanical properties. The presented study aimed to develop a 129Xe phantom for quality assessment in a pre-clinical MRI at 9.4 Tesla. Given the transiency of gas polarization, in order to have a long-lasting phantom, 129Xe is highly pressurized instead of hyperpolarized: the SNR is improved just by increasing 129Xe density inside the phantom. We provide a method to create a 129Xe phantom with easy accessible materials both MRI compatible and able to withstand high pressures. The phantom is filled with a customizable Xenon-Oxygen mixture to replicate different T1 relaxation times. Inside the phantom, a silicon gel is used to enable both proton and Xenon imaging, assisting with image registration and interpretation. The diffusion of the Xenon inside the gel has been demonstrated, showing a large chemical shift relative to the 129Xe in the gas phase (193 ppm). The solubility of the gas can be utilized in future works to demonstrate, for the first time, the feasibility of 129Xe MRE.
Advancements in the engineering and scientific basis of the design of fishways : with an emphasis on the Murray-Darling Basin, Australia
Creators: name: White., Lindsay
Publisher: name: Monash University
Year: 2021

description: This thesis was scanned from the print manuscript for digital preservation and is copyright the author.
 Researchers can access this thesis by asking their local university, institution or public library to
 make a request on their behalf. Monash staff and postgraduate students can use the link in the References field.
Evidence for the Direct Detection of the Thermal Spectrum of the Non-Transiting Hot Gas Giant HD 88133 b
Creators: name: Piskorz, Danielle
name: Benneke, Bjorn
name: Crockett, Nathan R.
name: Lockwood, Alexandra C.
name: Blake, Geoffrey A.
name: Barman, Travis S.
name: Bender, Chad F.
name: Bryan, Marta L.
name: Carr, John S.
name: Fischer, Debra A.
name: Howard, Andrew W.
name: Isaacson, Howard
name: Johnson, John A.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: FOS: Physical sciences

description: We target the thermal emission spectrum of the non-transiting gas giant HD 88133 b with high-resolution near-infrared spectroscopy, by treating the planet and its host star as a spectroscopic binary. For sufficiently deep summed flux observations of the star and planet across multiple epochs, it is possible to resolve the signal of the hot gas giant's atmosphere compared to the brighter stellar spectrum, at a level consistent with the aggregate shot noise of the full data set. To do this, we first perform a principal component analysis to remove the contribution of the Earth's atmosphere to the observed spectra. Then, we use a cross-correlation analysis to tease out the spectra of the host star and HD 88133 b to determine its orbit and identify key sources of atmospheric opacity. In total, six epochs of Keck NIRSPEC L band observations and three epochs of Keck NIRSPEC K band observations of the HD 88133 system were obtained. Based on an analysis of the maximum likelihood curves calculated from the multi-epoch cross correlation of the full data set with two atmospheric models, we report the direct detection of the emission spectrum of the non-transiting exoplanet HD 88133 b and measure a radial projection of the Keplerian orbital velocity of 40 $\pm$ 15 km/s, a true mass of 1.02$^{+0.61}_{-0.28}M_J$, a nearly face-on orbital inclination of 15${^{+6}_{-5}}^{\circ}$, and an atmosphere opacity structure at high dispersion dominated by water vapor. This, combined with eleven years of radial velocity measurements of the system, provides the most up-to-date ephemeris for HD 88133.
description: 9 pages, 6 figures; accepted for publication in ApJ
Cost Overrun and Impact Assessment of Addis Ababa's Light Rail Transit Construction Project
Creators: name: Weyessa, Ewnetu
Publisher: name: National Academic Digital Repository of Ethiopia
Year: 2014

description: Transportation is the back bone of success in economic activities, it is necessary that a mass transit system like rail systems be constructed for efficient transportation of commuters. As a result of the growing emphasis on environmentally "clean" alternatives to private vehicles, transport ministries and public transport companies have been concentrating more on the expansion or development of transport systems that combine urban, suburban and regional transport, in which light rail systems linked to subway systems and major railways form a cohesive network (ILO, 1994). To facilitate rapid change and development the Ethiopian national urban transport policy (ENUTP) requires ensuring adequate efficient and high quality transport infrastructure to guarantee efficient mobility of goods and people .Although the proposed ENUTP of goods and people seeks to achieve these goals there are challenges which slow it down the most adequate being inadequate infrastructure in the current network arising from certain constraints. (Yetenayet, 2012) To alleviate this problem Ethiopia in its GTP (Growth and Transformation Plan) plans to construct more than 2395 Km standard gauge railway by Phase-one. As part of this phase – one plan, Ethiopia is constructing a Metropolitan electric railway in Addis Ababa which has a total length of 34.25 km (North-South line 16.9 km and East-West line 17.35 km) the two lines (North-South and East-West) use common track of about 2.7 km. and is designed to fit for elevated, at grade and below grade transportation and access. It has a high carrying capacity of 15,000 PPH (passengers per hour). (ERC,2014) The construction cost management of such a large project is very demanding and the construction cost of light rail transit project is relatively high in comparison road projects. Therefore the main purpose of this research is to assess the construction cost management practices being conducted in Addis Ababa's light rail transit project with the aim of identifying the presence and cause of cost overrun in the project and discuss mitigation measures which can be implemented in future railway projects.
The collapse modelling of thin-walled square steel sections subjected to combined bending and torsion and its relation to predicting the roll-over strength of passenger car roofs
Creators: name: John., White Gary
Publisher: name: Monash University
Year: 2021

description: This thesis was scanned from the print manuscript for digital preservation and is copyright the author.
 Researchers can access this thesis by asking their local university, institution or public library to
 make a request on their behalf. Monash staff and postgraduate students can use the link in the References field.
Stress and Fatigue Analysis of Solder Joints Subjected to Extreme Aging for Normal and Over-molded PCBs
Creators: name: Bashirzadeh, Milad
Publisher: name: University of Illinois at Chicago
Year: 2023

description: Electronic device applications in the automotive industry have expanded significantly during the past two decades. These electronic devices usually experience extreme temperature ranges (between -40°C to 140°C) from typical weather and day-to-night cycles or generated heat from the engine of the car. The electronic components inside these devices use solder alloys in their interconnection assembly. Thus, it is essential the interconnection assemblies won’t fail prematurely from the extreme temperature cycles. Therefore, it is critical to understand the material properties evolution of the solder alloys in the form of solder joints from thermal-cycle loads. Engineers and scientists have been conducting research in discovering methods to improve the lifespan of the solder joints exposed to thermal-cycle aging. In this study, overmolding was used as a potential method to improve the lifecycle of solder joints. Overmolding is an epoxy resin that can be injected molded onto the electronic components and solder joint by using a special mold. The performance of these samples was compared to the normal samples (without overmolding) and quantitatively measured. The prepared samples went under accelerated life test to mimic the extreme weather conditions that an automobile will experience in real life and to quicken the event. Multiple experimental techniques such as Knoop hardness, polarized light microscopy (PLM), x-ray diffraction (XRD), scanning electron microscopy- energy dispersive x-ray (SEM-EDS,) and high energy x-ray diffraction (HEXRD) were used to characterize the material properties and investigate the failure mechanism in the solder alloys exposed to extreme temperature ranges. Meanwhile, electrical impedance measurements are conducted on all the electronic modules to assess their reliability during the environmental test (thermal-mechanical loads). xiii In the results sections, the physics of fatigue and failure in solder alloys will be explained. This will include the dynamic recrystallization, grain coarsening of β-Sn and increase in the thickness of the primary intermetallic layer. Additionally, the mechanical property degradation of the solder joint from thermal cycle loads has been quantitatively measured in terms of hardness and elastic modulus. Furthermore, the improvement of the overmolding on the solder joint life cycle has been demonstrated using the characteristic lifetime from Weibull analysis. The results for an FEA model simulating a solder joint under extreme temperatures will be discussed, as well.
Dynamo-driven plasmoid formation from a current-sheet instability
Creators: name: Ebrahimi, F.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Plasma Physics (physics.plasm-ph)
subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: Axisymmetric current-carrying plasmoids are formed in the presence of nonaxisymmetric fluctuations during nonlinear three-dimensional resistive MHD simulations in a global toroidal geometry. We utilize the helicity injection technique to form an initial poloidal flux in the presence of a toroidal guide field. As helicity is injected, two types of current sheets are formed from 1) the oppositely directed field lines in the injector region (primary reconnecting current sheet), and 2) the poloidal flux compression near the plasma edge (edge current sheet). We first find that nonaxisymmetic fluctuations arising from the current-sheet instability isolated near the plasma edge have tearing parity but can nevertheless grow fast (on the poloidal Alfven time scale). These modes saturate by breaking up the current sheet. Second, for the first time a dynamo poloidal flux amplification is observed at the reconnetion site (in the region of the oppositely directed magnetic field). This fluctuation-induced flux amplification increases the local Lundquist number, which then triggers a plasmoid instability and breaks the primary current sheet at the reconnection site. The plasmoids formation driven by large-scale flux amplification, i.e. a large-scale dynamo, observed here has strong implications for astrophysical reconnection as well as fast reconnection events in laboratory plasmas.
description: 5 pages, 5 figures
Risks and Risk Management of Addis Ababa Light Rail Transit System Project
Creators: name: Wubshet, Bekele
Publisher: name: National Academic Digital Repository of Ethiopia
Year: 2015

description: Risk management of construction projects is increasingly felt critical to the success of projects in general and large projects in particular. Addis Ababa Light Rail Transit project is a large and complex project involving the construction of civil works and assembly of considerable electromechanical components. The project is undertaken through EPC Turnkey Contract. A research proposal was prepared to identify the risks that may thwart the success of this flagship Project of the city. Assessing the project risk management practice was also of prime concern. In order to understand the theoretical background, the research embarked upon intensive literature survey. Archival records including contract documents, reports, and correspondences were investigated. Questionnaires were distributed to respondents from the Employer and the Employer's representative. To supplement the low population of respondents and to further refine the responses, interviews were carried out with selected professionals involved in the project. The findings have shown that the project is exposed to the vagaries of various risks. These risks have the tendency of severely affecting one or more of the project objectives and even the wider public as well. Despite of this risk prevalence, the Employer has not instituted formal risk management system. The method of risk management is not structured and process oriented. The term risk itself is not also properly understood and the conventional practice of managing risks has wider departures from the internationally accepted practice. Furthermore, the research has given evidence that the way risk identification, analysis and treatment methods are handled is unsatisfactory. From among the three steps of risk management, risk analysis is the least practiced. Risk treatments are addressed through contract provisions by way of insurance and bonds. Although the contract document clearly allocates risks to both the Employer and the Contractor in acceptable manner, most respondents replied that the contractor carries most of the risks. This entails that most of the respondents have no detailed understanding of the contract clauses that specifically dwell on risk allocation.
Entrustable Professional Activities in an Intern Preparedness Course: Perceptions and Entrustment Decisions
Creators: name: Aiyer, Meenakshy K
Publisher: name: University of Illinois at Chicago
Year: 2023

description: Entrustable Professional Activities (EPA) have created a frameshift in undergraduate medical education. This retrospective cross-sectional study addressed the fourth-year medical students’ perceptions of their EPA knowledge and skills before and after the completion of the intern preparedness course (IPC) provided at the end of their medical curriculum. Pre- and Post-IPC survey and course debriefing data were used to assess students’ perception of their preparedness and comfort with performing EPAs before and after IPC. This study also studied the correlation between the faculty ad hoc entrustment decisions and the students’ observed behaviors on the OSCE checklist in the delivering bad news station. A total of 43 students and 17 students completed the pre and post IPC surveys respectively. The majority of the students were comfortable performing 10 of the 13 EPAs after participating in the intern preparedness course. There was a statistically significant increase in the comfort of the students obtaining informed consent for test after the completion of IPC. Students noted that there were opportunities to practice and receive feedback on all of the EPAs within the curriculum, but these depended in part on rotation, site, and faculty/residents. In the delivering bad news OSCE station, significant correlations exist between faculty ad hoc entrustment decision and specific observable behaviors in the checklist. Opportunities exist within the medical school curriculum to practice and receive feedback on all the EPAs, but experiences are variable and gaps remain. A boot camp experience can help fill the gaps and ensure that all students have the requisite skills. Assessment checklists can also help identify task behaviors that most strongly impact entrustment decisions. Curriculum developers need to plan carefully to embed the EPAs systematically in the curriculum.
Structural Analysis and Dynamic Simulation of Heavy Haul Train Coupler With Draft Gear for Rotational Effect
Creators: name: Awel, Mohammed
Publisher: name: National Academic Digital Repository of Ethiopia
Year: 2015

description: Coupler and draft gear package is the most important parts of heavy haul train .In my thesis basic consideration is the structural analysis and rotational behaviour effects of heavy haul train coupler and draft gear .The structural analysis of the coupler and draft gear was analyzed by ANSYS software and the 3D modeling by CATIA .The important of structural analysis is used to determine the strength of the coupler material, the maximum deformation and stress that acted on the coupler simply determined .Those helps us to determine the critical part needs more maintenance , and also used to determine which part is wear easily. Finally the structural analysis of coupler with draft gear is important in order to increasing the performance of the heavy haul train, decreasing of the train derailment due to coupler effects. When a locomotive coupler rotates at an angle, the lateral component of the coupler force has an adverse effect on the locomotive's safety, particularly in heavy haul trains. In this paper, a model of four locomotives and three couplers, a 100-ton heavy haul train is developed to analyse the rotation behaviour of the locomotive's coupler system and its effect on the dynamic behaviour of such a train's when operating on straight and curved tracks. The train model includes detailed coupler and draft gear with which to consider the hysteretic characteristics of the rubber draft gear model, the friction characteristics of the coupler knuckles, and the alignment-control characteristics of the coupler shoulder. The results indicate that the coupler's rotation behaviour differs between the lateral force, longitudinal force and vertical forces, significantly affecting the locomotive's running performance under the braking condition. A larger coupler rotation angle generates a larger lateral component, which increases the wheel set's lateral force and the derailment coefficient. Decreasing the maximum coupler free angle can improve the locomotive's operational performance and safety. Based on these results, the recommended maximum coupler free angle is 5◦.the dynamic simulation of individual coupler rotational angle due to parameter variation of forces. This parameter variation helps as to understand the coupler maximum rotational angles due to the lateral forces.
Heat and mass transfer in a 0.09 m I.D. circulating fluidized bed
Creators: name: White., Colin Craig
Publisher: name: Monash University
Year: 2021

description: This thesis was scanned from the print manuscript for digital preservation and is copyright the author.
 Researchers can access this thesis by asking their local university, institution or public library to
 make a request on their behalf. Monash staff and postgraduate students can use the link in the References field.
Hawking radiation is corpuscular
Creators: name: Mück, Wolfgang
Publisher: name: arXiv
Year: 2016
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: The total number of Hawking quanta emitted during the evaporation of a Schwarzschild black hole is proportional to the square of the initial mass or, equivalently, to the Bekenstein entropy. This simple, but little appreciated, fact is interpreted in terms of the recent discovery of black hole soft hair.
description: 6 pages, v.3: added reference
On the selection of damped Lyman alpha systems using MgII absorption at 2
Creators: name: Berg, T. A. M.
name: Ellison, S. L.
name: Prochaska, J. X.
name: Sanchez-Ramirez, R.
name: Lopez, S.
name: D'Odorico, V.
name: Becker, G.
name: Christensen, L.
name: Cupani, G.
name: Denney, K.
name: Worseck, G.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: The XQ-100 survey provides optical and near infrared coverage of 36 blindly selected, intervening damped Lyman alpha systems (DLAs) at 2 < z < 4, simultaneously covering the MgII doublet at 2796A, 2803A, and the Ly-alpha transition. Using the XQ-100 DLA sample, we investigate the completeness of selecting DLA absorbers based on their MgII rest-frame equivalent width (W2796) at these redshifts. Of the 29 DLAs with clean MgII profiles, we find that six (20% of DLAs) have W2796 < 0.6A. The DLA incidence rate of W2796 < 0.6A absorbers is a factor of ~5 higher than what is seen in z~1 samples, indicating a potential evolution in the MgII properties of DLAs with redshift. All of the W2796 < 0.6A DLAs have low metallicities (-2.5 < [M/H] < -1.7), small velocity widths (v90 < 50 km/s), and tend to have relatively low N(HI). We demonstrate that the exclusion of these low W2796 DLAs results in a higher mean N(HI) which in turn leads to a ~7% increase in the cosmological gas density of HI of DLAs at 2 < z < 4; and that this exclusion has a minimal effect on the HI-weighted mean metallicity.
description: Accepted into MNRAS Letters. 6 pages, 2 figures
Azimuthal Magnetorotational Instability at low and high magnetic Prandtl numbers
Creators: name: Guseva, A.
name: Hollerbach, R.
name: Willis, A. P.
name: Avila, M.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Fluid Dynamics (physics.flu-dyn)
subject: FOS: Physical sciences

description: The magnetorotational instability (MRI) is considered to be one of the most powerful sources of turbulence in hydrodynamically stable quasi-Keplerian flows, such as those governing accretion disk flows. Although the linear stability of these flows with applied external magnetic field has been studied for decades, the influence of the instability on the outward angular momentum transport, necessary for the accretion of the disk, is still not well known. In this work we model Keplerian rotation with Taylor-Couette flow and imposed azimuthal magnetic field using both linear and nonlinear approaches. We present scalings of instability with Hartmann and Reynolds numbers via linear analysis and direct numerical simulations (DNS) for the two magnetic Prandtl numbers of $1.4 \cdot 10^{-6}$ and $1$. Inside of the instability domains modes with different axial wavenumbers dominate, resulting in sub-domains of instabilities, which appear different for each $Pm$. The DNS show the emergence of 1- and 2-frequency spatio-temporally oscillating structures for $Pm=1$ close the onset of instability, as well as significant enhancement of angular momentum transport for $Pm=1$ as compared to $Pm=1.4 \cdot 10^{-6}$.