Miracle-dz/UniFAR-FTUs huggingface dataset:
Fractal Applications in Fluid Mechanics of Enhancing Oil Recovery from Low-Permeability Oil Reservoirs by Gemini Surfactant Flooding

Gemini surfactant flooding is a promising technique to enhance oil recovery from medium-high permeability oil reservoirs. The screening of the surfactants is mainly based on their capability of lowering the surface tension between oil and water. However, gemini surfactants with high capability of lowering the surface tension do not necessarily enhance oil recovery from low-permeability oil reservoirs. Based on the fractal analyses of low-permeability cores and molecular spacer group, the fluid mechanics of gemini surfactant flooding in low-permeability oil reservoir is discovered. The fractal dimensions of the spacer group of gemini surfactants should match the fractal dimensions of the pore structures of low-permeability oil reservoirs.
Modelling, simulation, and experimental evaluation of a crossflow heat exchanger for an aircraft environmental control system

Abstract Crossflow heat exchangers play a significant role in the operation of an aircraft's environmental control system (ECS). The bleed air supplied by an aircraft engine, at high pressure and high temperature, requires regulation and control in order to be used for various pneumatic services. In the present investigation, the transient temperature response of crossflow plate-and-fin ECS heat exchangers, having a large core capacity with both fluids unmixed, is investigated numerically and experimentally for perturbations experienced in temperature. A non-linear lumped model of crossflow heat exchangers with a state-space solution valid for equal fluid velocities is derived and evaluated, in terms of fluid placement and number of lumps (sections) required. Dependency of the heat transfer coefficient on flowrates is incorporated in the dynamic modelling of the heat exchanger. Two models are derived, and the variation of the mean exit temperatures of both fluids with time is compared for the two alternative models, with consideration of the number of transfer units and heat capacitance rate ratios. One model requires axial lumping of the primary surface alone, as done in most of the existing models, and the second involves incorporating the effect of secondary surfaces (fins) on the heat exchanger transient performance. To quantify the importance of modelling the fins, a comparison of both simulation models with experimentally obtained data from a physical model is presented. By including fins and complex non-linearities in modelling of the ECS heat exchangers, a precise representation of the heat exchanger dynamics and accurate temperature responses are predicted. The model developments reported in this article can lead to improved aircraft ECS design and optimization.
Development of a Computer Vision Tracking System for Automated 3D Reconstruction of Concrete Bridges

Concrete bridge inspection is nowadays primarily a slow, subjective, non-comprehensive and costly set of procedures. Automation of the acquisition method is especially desirable for economical and repeatability reasons. Digital data is normally derived from well established non-destructive testing techniques, high resolution cameras and, more recently, by 3D laser scanning. This latter technique has some advantageous aspects in terms of reliability, repeatability, completeness and intuitiveness of the analysis of the resulting 3D reconstruction of the concrete structure. Statical laser scanning is, though, impractical for a variety of different reasons. A possible way of overcoming such difficulties is represented by dynamical measurement, achieved by moving in a prescribed manner the laser scanner during the scanning process. This procedure, on the other hand, requires a reliable tracking system for the laser scanner position and orientation. This work focuses on the development of such system, based primarily on computer vision measurement systems. A compact and lightweight 3D laser scanner has been placed on an automated carrier able to move along a standard inspection by-bridge, and a system of cameras and transducers has been designed to measure the carrier position and orientation based on the assumption of rigid body motion of the by-bridge multi-link arm during inspection operations. Several experimental tests have been performed to assess the viability of the proposed system and to evaluate its performance.Copyright © 2014 by ASME
A Study of Macrophages in the Aging Liver and in the Host Response to Engineered Lung Scaffolds

Macrophages are innate immune cells that contribute to tissue remodeling and homeostasis, respond to foreign antigens, and regulate the recruitment and activation of auxiliary immune cells. In chronic disease or a foreign body reaction, macrophages drive inflammation, leading to tissue damage and fibrosis. As such, understanding the developmental and phenotypic diversity of macrophages is of interest in both the pathobiology of disease as well as the design of novel therapeutics and materials. This dissertation examines macrophage biology in two contexts: the aging liver and the host response to engineered lung scaffolds. The liver contains two subsets of macrophages: a stable population of embryonically-derived Kupffer cells and a transient population of monocyte-derived macrophages. The dynamics of hepatic macrophages during the process of aging is unknown and may influence the development of chronic liver disease. Studies presented here demonstrate an increase in hepatic macrophages from naturally aged (19-months-old) mice compared to young counterparts (3-months-old). Macrophages from aged livers express significantly greater amounts of CD11b surface antigen and upregulate arginase strongly after exposure to interleukin-4, suggesting monocytic origins and a predisposition towards an alternatively activated phenotype. Aged livers also exhibit increased triglycerides and pro-inflammatory signals, including monocyte chemoattractant protein (MCP-1). Inhibiting MCP-1 signaling reduced lipids and inflammation but did not significantly alter the macrophage population. Additional methods to modulate hepatic macrophages remain to be studied in the context of age-associated pathologies. Following implantation of biomaterials, macrophages are recruited and polarize to a classical or alternatively activated phenotype, which can influence the outcome of the foreign body response. A positive outcome is associated with reduced inflammation and is crucial for the success of animal-derived organs to be used for xenotransplantation. Studies presented herein demonstrate that the removal of the foreign Gal-epitope from decellularized porcine lung scaffolds improves the host response in non-human primates, in part by reducing CD86 expression on macrophages and preventing substantial adaptive immune recognition upon reimplantation. Taken together, these studies further the understanding of macrophage biology in the aging liver and in the host response to Gal-epitopes and demonstrate novel strategies to reduce inflammation in chronic disease and tissue engineering contexts.
Recent Austrian Activities in Bridge Monitoring

Structural monitoring methods have been continuously developed over the last decades. Several applications of different systems and approaches have shown a constant trend towards support of conventional visual inspection using objective measurement data. The focus is on monitoring and surveillance of bridges which represent exceptionally sensible engineering structures. Knowledge gained from long-standing activities in the area of bridge monitoring in Austria are presented in this paper.
Power converter based method for suppressing power capacitor harmonic current

The damage to power capacitors caused by harmonic pollution was very serious in recent years due to the wide spread of power electronic related, nonlinear loads. The violent failure of power capacitors may result in power interruption and even accidents in industry. In this paper, a novel converter based protection method is proposed for protecting the power capacitor from harmonic damage. A power converter, serially connected to the power capacitor, is used to generate the harmonic components of utility voltage in the proposed method. Hence, the harmonic voltage across the power capacitor is cancelled. It means that the voltage dropped in the power capacitor will be maintained as sinusoidal, despite the waveform distortion of the utility voltage; the current flowing through the power capacitor is then also sinusoidal. Therefore, the power capacitor will not be damaged by the harmonic. A prototype is developed and tested to verify the performance of the proposed method. The test results show that the proposed method has the expected performance.
A Evolution Model of the Express Freight Network

A Evolution Model of the Express Freight Network is proposed based on the evolution theory of complex weighting network. The freight demands and space distance are considered into the preferential attachment scheme. Applying the model on the evolution of the express freight trains service network by China Railway Express, results show that the model is capable to embody the evolution laws with some indices slightly better than the real network.
Design models for anticipating future usage

In usage centred design designers need to consider a variety of users operating the intended product in a variety of ways in a variety of contexts. By tuning their design to potential ways of operation designers can prevent usability problems from occurring. In the project it was explored how design models, such as drawings, foam models and computer simulations, can assist designers to anticipate future usage. In the first instance operation of design models was compared to usage of actual products. Being non-functioning turned out to be the most relevant limitation of design models to observing 'natural' usage. The role of practitioners' expertise in anticipating future usage was also considered within the project. Practitioners predicted usability problems on the basis of various design models, with and without observing users operating the design models. In general it did not matter so much which design model the predictions were based upon, and whether users were observed or not. There were however large differences in the numbers of predictions between practitioners, each with a particular approach and personal knowledge and experience. It was shown that aspects such as empathy and sensitivity may be more important than 'hard' ergonomics knowledge
Lane Change Algorithm for Autonomous Vehicles via Virtual Curvature Method

This paper addresses the lane changing problem of autonomous vehicles when there is no road infrastructure support. The autonomous vehicle should drive from the current lane to the adjacent lane in the absence of a reference path to guide the vehicle to the new lane. We suggest an algorithm that incorporates a virtual road curvature with bicycle model for lane change guidance. As the name suggests, the virtual road curvature does not physically exist. It is a user assigned radius of a curved path which connects the current lane to the adjacent lane. Since the lateral sensor readings during lane changing maneuver are erroneous, the steering angle along with the virtual curvature is fed into a bicycle model to estimate the lateral position during the transition to the next lane. Details of the algorithm and the virtual road curvature determination are presented in the paper. In contrast to other lane changing methods, controller switching is not required and the same controller is for both lane keeping and lane changing. The algorithm is verified experimentally and the results are comparable with lane changing with physical transition lane.
Yucca Mountain drift scale test progress report

The Drift Scale Test (DST) is part of the Exploratory Studies Facility (ESF) Thermal Test being conducted underground at the potential high-level nuclear waste repository at Yucca Mountain, Nevada. The purpose of the ESF Thermal Test is to acquire a more in-depth understanding of the coupled thermal, mechanical, hydrological, and chemical processes likely to be encountered in the rock mass surrounding the potential geological repository at Yucca Mountain. These processes are monitored by a multitude of sensors to measure the temperature, humidity, gas pressure, and mechanical displacement, of the rock formation in response to the heat generated by the heaters. In addition to collecting passive monitoring data, active hydrological and geophysical testing is also being carried out periodically in the DST. These active tests are intended to monitor changes in the moisture redistribution in the rock mass, to collect water and gas samples for chemical and isotopic analysis, and to detect microfiacturing due to heating. On December 3, 1998, the heaters in the DST were activated. The planned heating phase of the DST is 4 years, and the cooling phase following the power shutoff will be of similar duration. The present report summarizes interpretation and analysis of thermal, hydrological, chemical, and geophysical data for the first 6 months; it is the first of many progress reports to be prepared during the DST.
Preliminary implementation of improved heat transfer and impingement-direction ice growth modeling in numerically simulated ice accretion (LEWICE/X

Experimental observations have shown that discrete rime ice growths called feathers, which grow in approximately the direction of water droplet impingement, play an important role in the growth of ice on accreting surfaces for some thermodynamic conditions. An improved physical model of ice accretion has been implemented in the LEWICE 2D panel-based ice accretion code maintained by the NASA Lewis Research Center. The LEWICE/X model of ice accretion explicitly simulates feather growth within the framework of the LEWICE model. Water droplets impinging on an accreting surface are withheld from the normal LEWICE mass/energy balance and handled in a separate routine; ice growth resulting from these droplets is performed with enhanced convective heat transfer approximately along droplet impingement directions. An independent underlying ice shape is grown along surface normals using the unmodified LEWICE method. The resulting dual-surface ice shape models roughness-induced feather growth observed in icing wind tunnel tests. Experiments indicate that the exact direction of feather growth is dependent on external conditions. Data is presented to support a linear variation of growth direction with temperature and cloud water content. Test runs of LEWICE/X indicate that the sizes of surface regions containing feathers are influenced by initial roughness element height. This suggests that a previous argument that feather region size is determined by boundary layer transition may be incorrect. Simulation results for two typical test cases give improved shape agreement over unmodified LEWICE. Thesis Supervisor: R. John Hansman Title: Associate Professor
Control of Yaw Disturbance Using Fuzzy Logic Based Yaw Stability Controller

Yaw stability is an important consideration for the vehicle directional stability and handling behavior during emergency maneuvers. In order to maintain the desired path of the vehicle, in presence of disturbances due to cross wind, different road conditions, and tire deflections, a fuzzy logic based yaw stability controller is proposed in this paper. Proposed control system receives yaw rate error, steering angle given by the driver, and side slip angle as inputs, for calculating the additional steering angle as output, for maintaining the yaw stability of the vehicle. As the side slip angle cannot be measured directly in a vehicle, it was estimated using a model based Kalman observer. A two-degrees-of-freedom vehicle model is considered in the present work. The effect of disturbance on yaw rate and yaw rate error of the vehicle is simulated for sinusoidal, step maneuver and compared with the existing fuzzy control system which uses two inputs such as steering angle and yaw rate. The simulation results show better performance of the proposed fuzzy based yaw controller as compared with existing control system. Proposed fuzzy based yaw stability controller can be implemented in steer-by-wire system for an active front steering of a road vehicle.
Generation of 33 GHz stable pulse trains by subharmonic electrical modulation of a monolithic passively mode-locked semiconductor laser

The first successful demonstration of subharmonic hybrid mode-locking of a monolithic semiconductor laser is reported. 33 GHz pulse trains with reduced phase noise are obtained from the laser by modulating its saturable absorber electrically at cavity subharmonic frequencies of 16.5, 11, and 8.25 GHz. Amplitude modulation as low as -17.4 dBc is observed under 16.5 GHz modulation.
Lane keeping control strategy with direct yaw moment control input by considering dynamics of electric vehicle

This article presents the alternative lane keeping control strategy with direct yaw moment control (DYC) that utilizes the transverse driving torque distribution. With the sophisticated structure of today’s electric vehicle, the small-size motor can be placed into each driving wheel so that the DYC input can be easily and precisely achieved by controlling the in-wheel-motors independently. The information of road position is acquired by vision system via CCD camera and on-board image processing system. As a feature of the proposed system, the lateral deviation detected by CCD camera is converted into the desired yaw rate for tracing the desired lane. Then, the yaw moment control input is theoretically determined to achieve the desired yaw rate from the viewpoint of vehicle dynamics. This article presents the theoretical analysis of lane keeping control characteristics using linear vehicle model on planar motion, and experimental study using micro-scale electric vehicle to verify the effectiveness of the proposed strategy.
Three degree-of-freedom piezoelectric ultrasonic micro-motor with a major diameter of 350 µm

A three degree-of-freedom (DOF) micro-motor comprising a hollow cylindrical transducer with slots novelly inserted, mounted to a lead zirconium titanate (PZT) piezoelectric element, was developed. Reversible rotation about three orthogonal axes was obtained at frequencies above 190 kHz. The peak torque about the transverse (x and y) and longitudinal (z) axes was 1.33, 1.23 and 2.38 nNm, respectively, at 21.2 VRMS. An electrical control scheme was employed to demonstrate the ability to operate these micro-motors at the low speeds necessary for many applications, including minimally invasive surgery (MIS). This micro-motor represents a significant step towards the development of true microscopic multi-DOF actuators, which can be integrated with MIS equipment, for example, in order to provide surgeons with better operability, dexterity and control deep within a patient's body.
Contribution of Surface Finish Monitoring Signals in CNC Taper Turning

On-line monitoring systems eliminate the need for post-process evaluation, reduce production time and costs, and enhance automation of the process. The cutting forces, mechanical vibration and acoustic emission signals obtained using dynamometer, accelerometer, and acoustic emission sensors respectively have been extensively used to monitor several aspects of the cutting processes in automated machining operations. Notwithstanding, determining the optimum selection of on-line signals is crucial to enhancing system optimization requiring a low computational load yet effective prediction of cutting process parameters. This study assess the contribution of three types of signals for the on-line monitoring and diagnosis of the surface finish (Ra) in automated taper turning operations. Systems design were based on predictive models obtained from regression analysis and artificial neural networks, involving numerical parameters that characterize cutting force signals (Fx, Fy, Fz), mechanical vibration (ax, ay, az), and acoustic emission (EARMS).
Impak pembangunan tebingan sungai ke atas persekitaran fizikal dan manusia

Development and environment are two phenomena which very synonym in recent development. Generally, development demands will bring positive or negative impact to the environment. Therefore, this paper work will discuss the study of the impact of Malacca River bank development at Bandar Hilir, Malacca to the environment, especially to human environment. The finding of this study shows that the impact of Malacca River bank construction and beautify can be classified into four main impacts. The impacts are restructuring of layout, tourists attraction, infrastructure development and environmental quality. The finding of this study also shows that river bank development and environmental changes give new shift to local society benefits to generate higher quality and dynamic life. In effort to attain the prosperous and equipoise in this river bank development, it is not involved only the administration, but also need the involvement of all parties such as the NGOs, mass media and society.
Advances in Experimental Study on Seismic Performance of Double C Steel Joints with Gusset Plate

It requires higher seismic performance of buildings. Double C steel structures with gusset plate have better seismic performance than general concrete structures and steel structures, and few studies have looked at its bending joints. Through the experimental analyses on seismic performance of Double C steel joints with gusset plate, we get the conclusion that this type of joints have high bending capacity, stable strength degradation, obvious initial stiffness degradation, good energy dissipation and ductility, and look forward to the development and application prospect of this compound section.
Percutaneous Transforaminal Endoscopic Discectomy for Lumbar Disc Herniation: A Retrospective Study

Aim: To explore the long-term outcome of patients with lumbar disc herniation (LDH) performed with percutaneous transforaminal endoscopic discectomy technique (PTED). Materials and methods: In this retrospective study, we collected the medical records from 974 patients with LDH who received PTED operation from May 2010 to July 2015. Follow-up measurements were performed at 1, 3, 6 and 12 months after surgery. Before and after surgery, visual analogue scale (VAS) was used for evaluating pain in leg and low back. Oswestry Disability Index (ODI) was used for evaluating the recovery of function. Japanese Orthopaedic Association (JOA) and modified MacNab criteria were used for clinical efficacy evaluation. Results: We found that the mean value of VAS and ODI were significantly decreased at each follow-up time points compared with that before operation (each p<0.01). The JOA showed significantly improving after the surgery through the follow-up period (each p<0.05). Furthermore, according to the modified MacNab criteria, the overall response of clinical efficiency was excellent in 32.7% patients and good in 54.9% patients. Conclusion: PTED performed with broad, easy, and immediate surgery (BEIS) technique is an effective endoscopic discectomy approach for the treatment of LDH.
Crystallization of Aluminium Alloys

The structure and properties of cast metals and alloys are in a high degree influenced by crystallization conditions. By the technological interventions into the crystallization process the mechanical properties and structural parameters of castings can be enhanced. The present contribution deals with the regularities of crystallization of alloys Al-Si produced by die casting process.