Miracle-dz/UniFAR-FTUs huggingface dataset:
Numerical simulation of internal fluidisation and cavity evolution due to a leaking pipe using the coupled DEM-LBM technique

Motivated by internal fluidisation due to a leaking pipe, this thesis aims to achieve a deeper understanding of the leakage-soil interaction by numerical simulations. The coupled DEM (Discrete Element Method) – LBM (Lattice Boltzmann Method) technique has been regarded as a promising tool to efficiently provide detailed description of fluid-particle systems, especially with intensive fluid-particle interactions. Therefore, FPS-BHAM, a 2D DEM-LBM computer code is developed for this thesis. In this code, DEM models the soil as an assembly of circular particles, and LBM is employed for fluid flow simulations. The Immersed Moving Boundary (IMB) scheme is adopted for the treatment of fluid-particle interaction. Numerical results are validated against existing experimental findings. Different regimes of bed behaviour are demonstrated under various flow rates. The onset of fluidisation is studied by analytically deriving for the flow equation and fluidising pressure, which are compared with numerical solutions. Moreover, deeper insights are made into the post-fluidisation phenomenon. The mechanism underlying a stable cavity is explored, and how a cavity evolves with different factors is also investigated through parametric studies.
Assembling International Equity Datasets -- Review of Studies on the Cross-Section of Common Stocks

This paper reviews the data sources used in the research on the cross-section of international stock returns. Covering the wide range of internationally focused papers I give an overview of the applied data, sample coverage, classification schemes and data cleaning methods. I address the quality concerns in case of the non-U.S. data and methodologically relevant specifics of international data analysis providing references to available solutions. In regards to data cleaning I give an overview of applied screens, pointing out their diversity across studies. On that way I offer a structured insight into challenges and specifics of rapidly increasing amount of papers discussing the cross-section of common stocks in both single-country and multiple country frameworks.
GaAs TUNNETT Diodes and InP Gunn Devices for Efficient Second-Harmonic Power Generation Above 200 GHz

Low-noise operation and significant RF power levels were demonstrated recently with GaAs TUNNETT diodes and InP Gunn devices in fundamental-mode operation at W-band (75-110 GHz) and D-band (110-170 GHz) frequencies. State-of-the-art RF power levels of 100 ± 5 mW at 100-107 GHz from TUNNETT diodes as well as > 200 mW at 103 GHz, > 130 mW around 132 GHz, and > 80 mW at 152 GHz from Gunn devices were measured, which correspond to dc-to-RF conversion efficiencies of 5.8-6.1 % at 100-107 GHz, > 2.3 % at 103-132 GHz, and > 1.4 % at 152 GHz. As shown with the first experimental results, e.g., RF power levels of > 0.3 mW at 283 GHz from Gunn devices and > 0.6 mW at 210 GHz from TUNNETT diodes, both two-terminal devices exhibit strongly nonlinear characteristics. Therefore, second-harmonic power generation was investigated further theoretically and experimentally. State-of-the-art RF power levels of 9 mW at 209 GHz and > 4 mW at 235 GHz from TUNNETT diodes as well as more than 1 mW at 280 GHz from Gunn devices were measured with a submillimeter-wave dry calorimeter. Corresponding dc-to-RF conversion efficiencies were > 1 % at 209 GHz and > 0.6 % at 235 GHz. Simulations revealed a large modulation in the depletion width of the TUNNETT diodes and explained the high up-conversion efficiencies observed. The results from TUNNETT diodes compare favorably with those from Schottky varactor diode frequency multipliers that are driven by transferred-electron oscillators. As expected from the excellent noise performance in the fundamental mode, these free-running oscillators showed clean spectra with a low phase noise of, e.g., well below 94 dBc/Hz at a frequency off the carrier of 500 kHz.
Physical training for loaded marching performance among British Army recruits

Study 1 quantified the validity and repeatability of an automated on-line (ON) gas analysis system during sub-maximal loaded marching (LM) against that of the Douglas Bag (DB) approach. The 95% ratio Limits of Agreement (LoA) revealed the ON system systematically overestimated V02 by -16% (1.16 (x/-i-1.19). The Bland and Altman plots revealed DB repeatability was almost two-fold better than ON (-9% vs. -15%), thus the DB approach should be used subsequently to measure human expired gases. Study 2 investigated the difference between an LM maximal oxygen uptake protocol (LMp) versus a standard running protocol (Rp). The LMp V02max was lower than Rp (48.6 ± 4.3 ml·kg-I·min-I vs. 51.3 ± 4.0 ml·kg-I·min-I, P=0.001). Thus, the quantification of sub-maximal LM exercise intensity will be underestimated by -5% if derived from a running tiOzmax protocol. Study 3 investigated the repeatability of accepted and potential determinants of Loaded Marching Performance (LMP). The LoA revealed the repeatability of Loaded Marching Economy (LME) (0.98 (x/-i-1.09», V02max (1.01 (xl-i-1.07», upper body dynamic strength (1.01 (x/-i- 1.11», and anthropometric measures (1.00 (x/-i- 1.02» to (1.00 (x/-i- 1.07» was reasonable, but dynamic leg strength (1.06 (x/-i-1.14» and isometric strength (1.00 (x/-i-1.12» to (0.99 (x/-i-1.l6» were large. Study 4 established the determinants of 2.4 km LMP from a test battery performed at the beginning of British Army infantry training. The best mathematical model of LMP included the independent variables of LME (r=0.65), 2.4 km run time (r=0.42), and peak static lift strength (r=0.48). This explained 65% of the variation in LMP, and had a prediction error of ± 51 s. Mathematically, LME and 2.4 km run time exerted the greatest influence on LMP, whereas the influence of static lift strength on LMP was small. Study 5 investigated the physical and physiological responses of the established determinants of LMP during 24 weeks of British Army infantry training. Loaded marching performance improved 7.0% (900 s to 837 s, P=0.001), LME 9.6% (2.28 I·min- I to 2.06 I·min- I , P .
Modeling Wave Transformation in the Surf Zone.

Abstract : By drawing a macroscopic analogy between an idealized surf zone and a hydraulic jump, an expression for the spatial change in energy flux due to breaking is developed. Analytical solutions for wave height decay due to shoaling and breaking on a flat shelf and a plane beach are presented and the results compared with laboratory data from Horikawa and Kuo (1966). The agreement is good. Setdown/setup in mean water level, bottom friction losses, and bottom profiles of arbitrary shape are introduced next and the equations transformed for numerical solution. The model is calibrated and verified with laboratory data with good results for the wave decay, but not so favorable results for setup. A test run on a prototype scale profile containing three bar and trough systems demonstrates the model's ability to describe the shoaling, breaking, and wave reformation process. Bottom friction is found to play a negligible role in wave decay in the surf zone when compared with shoaling and breaking.
Modeling and control of thermoacoustic instabilities

This work deals with modeling and control of thermoacoustic combustion instabilities in lean premixed combustion systems. Because of the complex interactions present in thermoacoustic systems, a network modeling approach is used. The model of each network element or subsystem is obtained analytically, numerically, or by making use of experimental techniques. The dynamics of a network system are determined experimentally by making use of a transfer matrix measurement technique. The transfer functions of a premixed flame have been determined experimentally on an atmospheric combustion test facility with a full-scale gas turbine burner, for a wide variety of operating conditions. An analytical model of the dynamic behavior of the reaction zone was made. In this model, the heat release fluctuations are assumed to be caused by fluctuations of the mass fraction of fuel and by fluctuations in the burning velocity. The model proved to be in good agreement with experimental results. Wave propagation in complex three-dimensional geometries is modeled by making use of a modal expansion technique. The modes used for the modal expansion can be obtained analytically for relatively simple geometries, or numerically (finite element method) for geometries of any complexity. By representing the modal expansion in state-space, a very numerically efficient and robust model is obtained. The thermoacoustic network model combines the state-space representations of the sub-systems in one system. The system can be analyzed in the time domain or in the frequency domain. The stability analysis is straightforward and does not require a numerical search. Non linear elements can easily be incorporated in the time domain simulation. This novel method has been validated by comparison with analytic solutions of simple thermoacoustic systems found in literature, by comparison with Finite Element codes, and by comparison with experimental results. An excellent agreement was found for all comparisons. When including non-linear elements in an annular system, a rotating acoustic field is predicted, which corresponds to experimental observations. This result has been verified analytically. Based on network models, a model based controller has been obtained using H∞ optimization. This controller has been tested in simulation and experiment on a single burner rig and proved to suppress acoustic levels by more than 25dB. An adaptive controller, based on a genetic algorithm, has been developed that does not require any knowledge about the system. This controller has been tested and proved to have similar performance as the model-based controllers. An active control system for multi-burner configurations has been developed and proved to perform well in simulations.
Selection for Accelerated Basic Combat Training

Abstract : The U.S. Army asked the U. S. Army Research Institute for the Behavioral and Social Sciences (AI) to develop a tool to select qualified candidates for an accelerated Basic Combat Training (BCT) track. The tool was to incorporate non-cognitive measures to provide broader measurement than an existing procedure which relied on a cognitive test and a physical fitness test. The tool was developed over two phases, a development phase and a validation phase. The results suggested that non-cognitive assessment can contribute to the identification of the most well-prepared Soldiers for a more challenging training regimen. However, the results were not sufficiently consistent across the two phases to suggest a stable model for identifying such Soldiers.
Tools for Autonomous Process Control

There is an ongoing trend towards higher automation level in process control systems. The purpose of a plant is to manufacture some product at a high production rate with a consistent quality, while minimizing the use of resources in terms of energy consumption, raw material and labor. With a higher degree of autonomy in the control system, it is possible to improve all these aspects, thus increasing the profit of the plant. When the control system is not able to solve a task by itself, it should support the human interaction with good software tools. This thesis treats different aspects of autonomous process control. A functional architecture of the control system is presented. The focus is on autonomy on the local control loop level. A list of desired functionality for an autonomous single loop controller is presented. This list consists of methods for initialization, assessment of basic process features, selection and tuning of on-line controller, monitoring of the on-line control performance, and fault diagnosis. Implementation aspects and software architectures of an autonomous single loop controller are also discussed. In particular, sequential control using the graphical language Grafchart is studied. The thesis also gives detailed presentations of three different tools and methods that can be used in an autonomous control system. An interactive tool for preliminary assessment of the process dynamics is presented. It is based on analysis of data from one or more step response experiments. A simple dynamical model, possibly combined with a static non-linear function, can easily be obtained. The model can be used for calculating parameters for a PI or PID controller. A new method for automatic tuning based on relay feedback is developed. A relay with time-varying hysteresis is used in order to achieve excitation over a large frequency interval. An estimation of the frequency response of the process is obtained by frequency domain identification. This estimation is used together with optimization methods for robust PI and PID controller design. A simple strategy for fast set point response is presented. It mimics what experienced process operators often do manually to obtain fast set point step responses with no overshoot. The strategy consists of a short sequence of steps in the control signal. Conditions for good switching times are given. These conditions can be applied with varying degrees of process knowledge. (Less)
Simulating the Effect of Microclimate on Human Behavior in Small Urban Spaces

Author(s): Lam, Fung Ki | Advisor(s): Kalay, Yehuda E | Abstract: This dissertation describes a behavior simulation model which could reveal spatial usage pattern of small urban places in association with the tangible physical built environment and the intangible microclimatic conditions. The simulation model extends the existing environmental assessments which do not include human interactions and human behavior simulations which do not take into account microclimatic conditions. It addresses the problem of predicting and evaluating the impacts of microclimatic conditions on the spatial usage of its human inhabitants, which has been studied, but not successfully implemented in the past. The concept is to carry out a virtual post occupancy evaluation which virtual users would exhibit their spatial usage pattern according to the environmental conditions and physical environment so experienced. Evaluators then could see how virtual users perform under certain conditions and assess if the design intention is achieved.The simulation model is developed using Wei Yan's (Yan, 2005) urban simulation model as a base. In addition Yan's usability-based building model and agent-based behavior model, an environmental model is included. It manages environmental data from user input, database and other simulation programs. It records the shading and air speed profile onto the building model to affect individual user behavior, develops outdoor activity comfort maps which virtual users would use to develop activity option maps, and control collective usage pattern in terms of level of usage, activity type distribution and spatial distribution. To ensure quality results, the environmental model handles only relatively simple computation, like generating outdoor activity comfort maps. It does not handle assessments which require specialized algorithms and processes like air flow simulation and comfort evaluation. Rather, these assessments are handled by certified programs outside the system. The environmental model processes the result and distributes the information to the building model and the agent model to control the behavior of the virtual users at both collective and individual levels. At the collective level, the behavioral pattern is mainly governed by statistics obtained from a year round field study. At individual level, the behavior is based on well studied and defined behavioral rules which are derived from theoretical and practical environment-behavior studies. The simulation generates both graphical and textual outputs. The two dimensional graphical output offers views of paths of virtual users; the three dimensional output offers shows spatial usage as a whole; and textual output provide information of usage and thermal states. It is expected the result of this research to change how architects and environmental behavior experts will approach the design and evaluation of built environments.
Impact of intratumor heterogeneity on diffusion-weighted MRI as a prognostic indicator in lower rectal cancer

Background Diffusion-weighed MRI (DWI) has the potential to reveal intra-tumor pathological heterogeneity consisting of the stroma. The present study investigated the value of intra-tumor heterogeneity evaluated by DWI for predicting the survival of patients with lower rectal cancer (LRC). Methods A total of 172 LRC patients underwent radical surgery between 2009 and 2017. Patients with T1 tumors, distant metastasis, and no pre-operative MRI were excluded. Fifty-eight cases were targeted. Intra-tumor heterogeneity on DWI was quantified by an image analysis (MRI heterogeneous score of DWI: mrHSD). All enrolled cases were divided into two groups (high and low groups) according to median mrHSD. Results Median mrHSD was 0.457 (0.170–0.823), with a higher score indicating a more heterogeneous pattern on DWI. The frequency of a clinical diagnosis of lymph node metastasis and extramural vascular invasion was higher in the high group. Three-year overall survival (OS) and relapse-free survival (RFS) rates were significantly higher in the low group than in the high group (OS: 100% vs 84.6%, p = 0.012; RFS: 85.9% vs 55.6%, p = 0.027). A univariate analysis of RFS showed that the RFS rates of poorly differentiated LRC, a positive circumferential resection margin on MRI, and high mrHSD were worse (p = 0.097, 0.086, and 0.049). A multivariate analysis revealed that high mrHSD tended to be an independent factor for predicting post-operative recurrence (HR: 2.836, p = 0.060). Conclusion The quantitative evaluation of intratumor heterogeneity on DWI has potential as an imaging biomarker for predicting post-operative recurrence.
Narrative Communication Messaging in Raising Public Awareness of Type 2 Diabetes Risk – A Multi-Perspective Cartography

Two recent studies that tested among high British adults and among Americans, reported that half of participants Abstract Objectives: Type 2 diabetes is the seventh leading cause of death and disability worldwide. Estimates suggest that by 2035, 642 million people worldwide will suffer from diabetes. Higher awareness of risks of type 2 diabetes is a prerequisite to prevent or delay the onset of diabetes but, little attention has been paid to identifying effective communication messages to raise public awareness of risks of this disease and this is the focus of this study. Methods: A conjoint based procedure facilitated an experimental design testing the power of narrative persuasion messages as driving awareness of risks of type 2 diabetes based on stability of utilities. The sample comprised 50 Americans recruited by Luc.id, Inc. Results: Similarity in response patterns to messages uncovered three mindsets, each responsive to different messages. We identified effective messages for each mindset and developed a prediction tool assigning a person/group in the population to a sample mindset. Discussion: Members of Mindset1 respond to empowering messages depicting members as having control, as able to modify their behaviors. Members of Mindset2 respond to messages presenting doctors as enhancing the health literacy of members and informing them of ways to prevent diabetes. Members of Mindset3 respond to messages presenting patients as a resource for learning, information, and support. Messages used in campaigns emerged as ineffective across mindsets Conclusion: The prediction tool assigning people to mindsets may enable professionals to detect the psychological mind-set of an individual and drive health behavior changes using effective messaging.
Farmers’ Preferences for Modern Information Communication Technologies in Trinidad

In the island nation of Trinidad, farmers have access to public extension services provided through the Ministry of Agriculture, Land and Fisheries but still struggle to get the information they need in a timely manner. Information Communication Technologies (ICTs) offer opportunities to improve the relationship between Extension and farmers. This study, guided by the Uses and Gratification (U&G) theory, sought to assess Trinidadian farmers’ preferences for mobile ICTs. From a convenience sample of 200 farmers in Trinidad, results showed almost all farmers used text messaging, and most used multimedia messaging and WhatsApp. Farmers were deliberate in their selection of medium for receiving different types of information. Findings suggest two-way ICTs are contextually appropriate for communicating with Trinidadian farmers. This study highlights the importance of understanding the information needs and preferences of farmers to ensure effective extension service delivery. While many ICT mediums are available, communicators must seek to utilize those mediums that are widely accessible and adopted by the target audience. The U&G theory provided an appropriate framework to investigate farmers’ preference for ICTs and allowed a critical discussion on the suitability of ICTs in Trinidad’s extension system. Keywords: Information Communication Technologies (ICT); preferences; mediums; information; extension
Undergraduate research experiences developing virtual reality based educational modules

Over the past several years a number of virtual reality ( VR ) based educational modules have been developed, using undergraduate chemical engineering students as the primary day-to-day program developers. These students had minimal computer programming and no VR experience prior to starting their projects, and some of the students had not yet completed the relevant engineering courses. There have been fourteen different students involved in the project to date, over half of whom worked on the project for only a single term. This paper describes the experiences of this group, including the advantages and disadvantages to all concerned.
Evaluation of Serum Lipid Profile after Different Chemotherapeutic Regimens in Iraqi Patients with Breast Cancer

Objective: To investigate the effect of doxorubicin, cyclophosphamide and taxane chemotherapy on the lipid profile in Iraqi patients with breast cancer. Method: This cohort prospective study was carried out at the Biochemistry Department, Baghdad College of Medical Sciences, and at the Oncology Clinic, Oncology Teaching Hospital, Baghdad, Iraq, during the period from May 2019 to October 2019. It included 56 women with regular menstrual cycle (25-45 years) classified into 3 groups: GI: 29 women with primary breast cancer (before starting chemotherapy), GII: the same 29 women of GI who were finished 4 cycles of anthracycline chemotherapy (course 1) and GIII: which involved another 27 women who had finished both courses of chemotherapy, (course 1) and 4 cycles of taxanes (course 2). Serum cholesterol, LDL, HDL and TG were measured using colorimetric method. Results: The results of the present study showed that the (mean±SEM) of the serum cholesterol was decreased significantly (p<0.05) in GIII compared to GI and highly significantly (p<0.01) compared to GII. While, the serum HDL level was significantly (p<0.05) lower in GIII compared to GI. Concerning the serum LDL level, it was increased significantly (p<0.05) in GII compared to both GI and GIII. While; the serum TG level shows no significant difference between all groups. Conclusion: Iraqi women with breast cancer had an abnormal state of dyslipidemia that become worsened after chemotherapy.