Engineering Commons^™

Shape Evolution Of A Long Bubble Penetrating Liquids With Various Viscosities, Cheng-Hsing Hsu, Ching-Chuan Chang, Chia-Chuan Kuo, Kuang-Yuan Kung

Journal of Marine Science and Technology–Taiwan

This paper aims at the effect of gas flow and viscosity of the fluid on the profile of a long bubble. The gas flow controlled by a mass flow controller is injected into a tube filled with liquid silicon oil. The images of bubble profile are captured by a high-speed camera. The fractional converge of the liquid and the hollow ratio of the bubble is estimated by measuring the width of these images. The result shows that the values of Capillary number and Reynolds number increase as the gas flow rate increase under a constant viscosity. However, the hollow ratio …

Effects Of Surface Roughness And Flow Rheology On The Ehl Of Circular Contacts With Power-Law Fluid, Li-Ming Chu, Jaw-Ren Lin, Hsiang-Chen Hsu, Yuh-Ping Chang

Journal of Marine Science and Technology–Taiwan

The coupled effects of surface roughness and flow rheology on the Elastohydrodynamic lubrication (EHL) circular contact problems are analyzed and discussed. The average flow model is adapted for the interaction of the flow rheology of lubricant and surface roughness. The averaged Reynolds type equation, the rheology equations, the elastic deformation equation, and the force balance equation are solved simultaneously. The multilevel multi-integration (MLMI) algorithm and Gauss-Seidel iteration method are utilized to calculate the film thickness and pressure distributions. The effects of flow index, Peklenik number, and standard deviation of composite surface roughness on the film thickness and pressure distributions are …

A Numerical Study Of Cubic Parabolas On Railway Transition Curves, Tsung-I Shen, Che-Hao Chang, Kuan-Yung Chang, Cho-Chien Lu

Journal of Marine Science and Technology–Taiwan

This paper mainly focuses on the design of transition curves of the cubic parabola type in track alignment design. Equations for the transition curves are first derived from the theory of cubic parabolas using calculus techniques. They are then analyzed using numerical analysis methods. The proposed formulation is evaluated by comparison of its calculated results with data in 684 actual cases of transition curves. The accuracy of the proposed method is verified in this study by comparing the estimated results with collected data from actual engineering projects, and the applicability of the new method to the engineering practice of track …

An Improvement Of Wave Refraction-Diffraction Effect In Swan, Aw-Guei Lin

Journal of Marine Science and Technology–Taiwan

SWAN, a wind wave model, has been modified to take into account wave refraction-diffraction effects from the extended mild-slope equation when wind waves pass through a extremely uneven sea bottom in the presence of current. In our modified model, the diffraction correction parameter introduced by Holthuijsen et al. [10] has been adjusted to better predict the combined effect of the higher-order bottom effect, wave-bottom interaction and wave-current interaction. After a preliminary analysis, the influence of the correction parameter is discussed, and a comparison is made between the original and the new phase-decoupled versions of SWAN through some typical examples of …

On The Influence Of The Mode-Shapes Of A Marine Propulsion Shafting System On The Prediction Of Torsional Stresses, Bin Tang, Michael J Brennan

Journal of Marine Science and Technology–Taiwan

Torsional vibration predictions and measurements of a marine propulsion system, which has both damping and a highly flexible coupling, are presented in this paper. Using the conventional approach to stress prediction in the shafting system, the numerical predictions and the experimental torsional vibration stress curves in some parts of the shafting system are found to be quite different. The free torsional vibration characteristics and forced torsional vibration response of the system are analyzed in detail to investigate this phenomenon. It is found that the second to fourth natural modes of the shafting system have significant local deformation. This results in …

An Experimental Study Of Regular Long Crested Waves Over A Crescent Type Shoal, Wen-Kai Weng, Jaw-Guei Lin, Chun-Sien Hsiao

Journal of Marine Science and Technology–Taiwan

Converting the ocean wave energy into electric power is one possibility of the development of alternative and nonpolluting sources of energy. Many researches concerning converters and their converting efficiency of wave power were developed and discussed in the last years. However, converting wave energy into electric power does not only depend upon converting system but condition of sea state essentially. A calm sea state with lower wave energy is difficult to drive converting device working and is unable to satisfy the minimum economical requirement. Unfortunately, wave heights in the sea state around Taiwan are mostly too smaller to extract the …

Vulnerability Analysis Of A Smart Grid With Monitoring And Control System, Maggie Xiaoyan Cheng, Mariesa Crow, Robert F. Erbacher

Computer Science Faculty Research & Creative Works

Large scale power outage is typically the consequence of cascading failures propagated through a power system. To mitigate failure propagation, wide area monitoring and control system is introduced. However, as the physical system is tightly coupled with the cyber system, new threats are introduced due to possible cyber-attacks and failures of the communication system. This paper presents a new framework for vulnerability analysis. Under this framework, we can identify the vulnerable components and the critical components of a cyber physical system. Distinct from previous work, our model considers the interaction between the different components of the cyber physical system and …

Length And Temperature Dependent 1/F Noise In Vertical Single-Walled Carbon Nanotube Arrays, Robert A. Sayer, Jeffrey D. Engerer, N. S. Vidhyadhiraja, Timothy S. Fisher

Birck and NCN Publications

We report measurements of temperature-and length-dependent 1/f noise in vertical single-walled carbon nanotube (SWCNT) arrays. Carbon nanotubes are synthesized in a porous anodic alumina template with sub-micrometer channel lengths ranging from 100 to 700 nm. A significant difference is observed in the 1/f noise magnitude of quasi-ballistic and diffusive SWCNT devices, with quasi-ballistic devices exhibiting 1/f noise levels that are one to two orders of magnitude less than diffusively conducting devices. Furthermore, 1/f noise was measured from 90 to 400 K, and the noise prefactor decreased significantly at temperatures below 250 K. (C) 2013 AIP Publishing LLC. [http://dx.doi.org/10.1063/1.4800856]

Assessment Of Solar Photovoltaic Technologies Using Multiple Perspectives And Hierarchical Decision Modeling, Nasir Jamil Sheikh

Dissertations and Theses

The objective of this research is to build a decision model for a comprehensive assessment of solar photovoltaic technologies using multiple perspectives. These perspectives include: social, technological, economic, environmental, and political (STEEP) with each perspective consisting of multiple criteria. Hierarchical decision modeling and expert judgment quantification are used to provide the relative ranking of the perspectives and criteria. Such modeling is effective in addressing technology evaluations with competing and contrasting perspectives and criteria where both quantitative and qualitative measurements are represented. The model is then operationalized by constructing desirability functions for each criterion. The combined results provide an overall numerical …

Comparative Study Of Artificial Lighting Systems With Different Fixtures Considering Daylight Availability, Leticia Niero Moraes, Anderson Claro

CIBSE & SLL International Lighting Conference, Dublin, 2013

The use of daylight is indicated as a primary factor in energy savings of buildings, since it can reduce the use of electric lighting through control systems. However, the efficiency of systems is also associated with technical characteristics and performance of various elements. The positioning of fixtures, as well as its specifications can contribute for environmental comfort and energy conservation. Such concerns, however, are not part of the currently established practice of lighting design professionals. Considering this gap, this paper seeks to develop a study that addresses the integration of natural and electric light. The methodology is based on evaluating …

12th Annual Undergraduate Student Symposium, Farquhar Honors College

Undergraduate Student Symposium

The Undergraduate Student Symposium, sponsored by the Farquhar College of Arts and Sciences, presents student projects through presentations, papers, and poster displays. The event serves as a “showcase” demonstrating the outstanding scholarship of undergraduate students at NSU. The Symposium is open to undergraduate students from all disciplines. Projects cover areas of student scholarship ranging from the experimental and the applied to the computational, theoretical, artistic, and literary. They are taken from class assignments as well as from independent projects. The projects do not have to be complete; presentations can represent any stage in the concept’s evolution, from proposal and literature …

Helping To Explain Lighting Quality & Energy Efficiency To Non-Experts, Anna Whittaker, Julie Gore, Stuart Mucklejohn

CIBSE & SLL International Lighting Conference, Dublin, 2013

CIBSE & SLL International lighting Conference

15 Ways To Save Energy, Iain Macrae

CIBSE & SLL International Lighting Conference, Dublin, 2013

CIBSE & SLL International Lighting Conference

In-Field Measurment Of Cylindrical Illuminance And The Impact Of Room Surface Reflectance On The Visual Environment, James Duff

CIBSE & SLL International Lighting Conference, Dublin, 2013

CIBSE & SLL International Lighting Conference

Energy And Cost Savings By Using Lighting Controls In Offices, Carmen Munoz Munoz, David Moreno, Paula Esquivias, Ignacio Acosta, Jaime Navarro

CIBSE & SLL International Lighting Conference, Dublin, 2013

CIBSE & SLL International Lighting Conference

Lighting Quality For All, Peter Boyce

CIBSE & SLL International Lighting Conference, Dublin, 2013

CIBSE & SLL International Lighting Conference

Looking At Art In A New Light, Emrah Baki Ulas, Mirjam Roos

CIBSE & SLL International Lighting Conference, Dublin, 2013

CIBSE & SLL International Lighting Conference

Retrofit Electrochromic Glazing In An Open Plan Office: A Case Study, Ruth Kelly, Birgit Painter, John Mardaljevic, Katherine Irvine

CIBSE & SLL International Lighting Conference, Dublin, 2013

CIBSE & SLL International Lighting Conference

Compositional Characterization Of Soil Organic Matter And Hot-Water Extractable Organic Matter In Organic Horizons Using A Molecular Mixing Model, Ankit Balaria, Chris E. Johnson

Civil and Environmental Engineering - All Scholarship

Purpose Microbial decomposition of soil organic matter (SOM) is generally believed to be heterogeneous, resulting in the preferential loss of labile compounds such as carbohydrates and proteins and the accumulation of recalcitrant compounds such as lipids and lignin. However, these fractions are difficult to measure directly in soils. We examined patterns in the biomolecular composition of SOM and hot-water-extractable organic matter (HWEOM) by using a molecular mixing model (MMM) to estimate the content of carbohydrates, protein, lipids, and lignin.

Materials and methods Organic-horizon soils from Spodosols at the Hubbard Brook Experimental Forest in New Hampshire, USA were analyzed for this …

Ceas E-News 04.12.2013, College Of Engineering And Applied Sciences

College of Engineering and Applied Sciences News

Wheelchair ramp, faculty accolades, KAMSC science fair, outstanding seniors, Sigma Gamma Tau

Systematic Design Of 10-Bit 50ms/S Pipelined Adc, Kehan Zhu, Sakkarapani Balagopal, Vishal Saxena

Electrical and Computer Engineering Faculty Publications and Presentations

A systematical design analysis of a 10-bit 50MS/s pipelined ADC is presented. With an opamp-sharing technique, the power consumption is reduced drastically. Simulated in a 130-nm CMOS process, it achieves a 58.9dB signal-to-noise ratio (SNR), a 9.3 effective number of bits (ENOB), 64dB spurious free dynamic range (SFDR) with a sinusoid input of 4.858-MHz 1-V_pp at 50MS/s, and consumes less than 24 mW from a 1.2-V supply.

Pecvd Of GeXS1−X Films For Nano-Ionic Redox Conductive Bridge Memristive Switch Memory, Muhammad Rizwan Latif, Maria Mitkova, Gary Tompa, Elane Coleman

Electrical and Computer Engineering Faculty Publications and Presentations

This study is related to fabrication and characterization of redox conductive bridge memristors (RCBM). An active region in RCBM is formed by chalcogenide glass (ChG) doped with silver (Ag). We report the application of plasma enhanced chemical vapor deposition (PECVD) method for depositing ChG films which gives the advantage of flexibility in the composition and structure not easily achieved with sputtering or thermal evaporation. The growth kinetics of the deposition process, as well as the properties of the films is investigated. Optimal deposition conditions for reliable device performance are determined. The electrical characteristics of the devices fabricated at these conditions …

Standards And Codes, Peter Raynham

CIBSE & SLL International Lighting Conference, Dublin, 2013

CIBSE & SLL International Lighting Conference

Rethinking Daylighting And Compliance, John Mardaljevic

CIBSE & SLL International Lighting Conference, Dublin, 2013

CIBSE & SLL International Lighting Conference

Light Environment In Japanese Office Buildings, Nozomu Yoshizawa, Etsuko Mochizuki,, Toshie Iwata

CIBSE & SLL International Lighting Conference, Dublin, 2013

CIBSE & SLL International Lighting Conference.

Innovations In Light, John Gorse, Mike Simpson

CIBSE & SLL International Lighting Conference, Dublin, 2013

CIBSE & SLL International Lighting Conference

White Light-Informed Optical Properties Improve Ultrasound-Guided Fluorescence Tomography Of Photoactive Protoporphyrin Ix, Brendan P. Flynn, Alisha V. Dsouza, Stephen C. Kanick, Scott C. Davis, Brian W. Pogue

Dartmouth Scholarship

Subsurface fluorescence imaging is desirable for medical applications, including protoporphyrin-IX (PpIX)-based skin tumor diagnosis, surgical guidance, and dosimetry in photodynamic therapy. While tissue optical properties and heterogeneities make true subsurface fluorescence mapping an ill-posed problem, ultrasound-guided fluorescence-tomography (USFT) provides regional fluorescence mapping. Here USFT is implemented with spectroscopic decoupling of fluorescence signals (auto-fluorescence, PpIX, photoproducts), and white light spectroscopy-determined bulk optical properties. Segmented US images provide a priori spatial information for fluorescence reconstruction using region-based, diffuse FT. The method was tested in simulations, tissue homogeneous and inclusion phantoms, and an injected-inclusion animal model. Reconstructed fluorescence yield was linear with PpIX …

Strong Location Privacy: A Case Study On Shortest Path Queries [Invited Paper], Kyriakos Mouratidis

Research Collection School Of Computing and Information Systems

The last few years have witnessed an increasing availability of location-based services (LBSs). Although particularly useful, such services raise serious privacy concerns. For example, exposing to a (potentially untrusted) LBS the client's position may reveal personal information, such as social habits, health condition, shopping preferences, lifestyle choices, etc. There is a large body of work on protecting the location privacy of the clients. In this paper, we focus on shortest path queries, describe a framework based on private information retrieval (PIR), and conclude with open questions about the practicality of PIR and other location privacy approaches.

Wright State University Celebration Of Research, Scholarship And Creative Activities Book Of Abstracts Friday, April 12, 2013, Wright State University Office Of Undergraduate Research And Stemm Activities

Celebration of Undergraduate & Graduate Research, Scholarship, and Creative Activities Materials

The student abstract booklet is a compilation of abstracts from students' oral and poster presentations at Wright State University's second annual Celebration of Research, Scholarship and Creative Activities on April 12, 2013.

The Santa Clara, 2013-04-11, Santa Clara University

The Santa Clara

No abstract provided.