67 research outputs found
Recently Discovered Manuscripts by Naguib Mahfouz, and the Polemic Around his Famous Novel \u27Awlad Haratina\u27
No full textThe Arabic Cultural program is organizing a lecture about recently rediscovered manuscripts by Naguib Mahfouz, and the polemic around his famous novel Awlad Haratina. The lecture (in Arabic) will be given by Muhammad Shuair, writer and journalist, author of the book: Awlad Haratina: Qissat al-Riwaya al-Muharrama
The Museum Explorer: User Experience Enhancement In A Museum
Get PDFA learner in an informal learning environment, such as a museum, encounters various challenges. After initial assessment, a set of methods were proposed that may enhance a learner’s experience in a museum using computer aided technologies. The most important insight was the need to support the museum visitor in three phases of activity: prior to the visit, during the visit, and after the visit. We hypothesized that software tools that could help connect these three phases would be helpful and valuable supports for the visitor. To test and evaluate our hypothesis, a system called “The Museum Explorer” was built and instantiated using the collection in the Museum of Antiquities located at the University of Saskatchewan. An evaluation of the Museum Explorer was conducted. Results show that the Museum Explorer was largely successful in achieving our goals.
The Museum Explorer is an integrated solution for visitors in museums across the pre-visit, visit, and post-visit phases. The Museum Explorer was designed to provide a means to connect and transfer user experience across the major phases of a museum visit. For each phase of a visitor’s experience, a set of tools was built that provides intelligent and interactive communication features. To assist visitors selecting artefacts to visit, a recommender system allows users to select a set of constraints. To better manage interactivity, features and functions were offered based on context.
A study was conducted with volunteer museum visitors. Results from the study show that the Museum Explorer is a useful support. Analysis of the usage data captured by the Museum Explorer has revealed some interesting facts about users’ preferences in the domain that can be used by future researchers
Teaching an Undergraduate Introductory Finite Element Analysis Course: Successful Implementation for Students Learning
No full textFour-Terminal Square Piezoresistive Sensors for MEMS Pressure Sensing
Get PDFThe sensitivity of four-terminal piezoresistive sensors commonly referred to as van der Pauw (VDP) structure is investigated. The VDP sensor is considered to be fabricated on (100) silicon due to its potential application in MEMS (microelectromechanical systems) pressure sensors. The sensitivity of the VDP sensor may be affected by misalignment during the etching/diffusion process, the nonuniformity of piezoresistive coefficients through the sensor thickness, and pad size with respect to the sensor size. For this particular analysis, the effect of VDP stress sensitivity on variations in pad sizes and through-the-thickness -coefficient variation are studied as the effect of misalignment has already been investigated by researchers. Two three-dimensional (3D) finite element analysis (FEA) models are first developed for both traditional VDP resistance and equivalent four-wire bridge measurements. Then, the FEA models are validated with the closed form analytical solutions for point contacts (“zero” pad size) under different biaxial loads. Once the FEA models are validated, additional simulations are conducted to understand the influence of different parameters on the voltage measurements for an equivalent four-wire bridge configuration. It is observed that pad size and through-the-thickness nonuniformity in piezoresistive constants adversely affect the sensor sensitivity
Dynamic Analysis of a Microscale Cricket Filiform Hair Socket
No full textFiliform hairs of crickets are of great interest to engineers because of their highly sensitive response to low velocity air currents. In this study, the cercal sensory system of a common house cricket has been analyzed. The sensory system consists of two antennae like appendages called cerci that are situated at the rear of the cricket’s abdomen. Each cercus is covered with 500–750 flow sensitive hairs that are embedded in a complex viscoelastic socket that acts as a spring -dashpot system and guides the movement of the hair. When the hair deflects due to the drag force induced on its length by a moving air-current, the spiking activity of the neuron and the combined spiking activity of all hairs are extracted by the cercal sensory system. The hair has been experimentally studied by few researchers though its characteristics are not fully understood. The socket structure has not been analyzed experimentally or theoretically from a mechanical standpoint. Therefore, this study aims to understand the dynamic response of socket and its interaction with the filiform hair. First, a 3D Finite Element Analysis (FEA) model, representing hair and hair-socket, has been developed. Then the dynamic analysis is conducted utilizing the appropriate load and boundary conditions based on the physical conditions that an insect experiences. These numerical analyses aid to understand the dynamic response of the hair and hair-socket system. The operating principles of the hair and hair-socket could be used for the design of highly responsive MEMS devices such as fluid flow sensors or micro-manipulators.
Copyright © 2015 by ASM
Nano-Indentation for Characterizing Mechanical Properties of Soft Materials
No full textWe have attempted to apply the computer-based finite element analysis (FEA) method to accurately measure the mechanical properties (e.g., hardness and elasticity) of a soft material by an indentation test. First, an axisymmetric model has been developed using commercially available FEA code ANSYS. The FEA model consisted of a thin Al-film resting on Si-substrate. A spherical indenter has been used to indent the Al-film, which traveled a predefined depth during the loading and unloading cycles. First, numerical simulations were conducted to get the force vs. displacement plot, which was later used to determine the modulus of elasticity and hardness of Al-film. The effects of substrate modulus and indentation depth were thoroughly investigated to determine the modulus and hardness of Al-film. The effect of friction, considered at the interface of indenter and Al-film, was found to offer minimum impact for relatively small indentation depth. The induced force on the Al-film by the indenter has been found to be higher with increasing indentation depth when friction was considered. However the contact stiffness, represented by the slope of the unloading curve, has been found almost the same with and without considering friction. The variation of substrate modulus has been found to be ineffective to capture the Al-film modulus for relatively small indentation depth. However for higher indentation depth, the substrate modulus has been found to offer profound effect to capture the film modulus. The hardness of the Al-film has also been found to be relatively unaffected with variation of substrate modulus. However, the hardness of the Al-film has been found to be higher with friction for relatively high indentation depth. Results obtained from this preliminary research are important to continue further investigation and to characterize the mechanical properties of other soft-materials, e.g., biofilms to minimize its detrimental effects and utilize its favorable aspects in industrial and biomedical applications.
Copyright © 2013 by ASM
EFFECTS OF INORGANIC PHOSPHORUS AND POTASSIUM ALONG WITH COWDUN.G AND VERMICOMPOST ON GROWTH, YIELD AND NUTRIENT CONTENT OF BRRI dhan62
Get PDFA Thesis
Submitted to the Faculty of Agriculture,
Sher-e-Bangla Agricultural Lniversity,Dhaka,
In partial fulfillment of the requirements for the degree of
MASTER OF SCIENCE
IN
AGRICULTURAL CHEMISTRY
SEMESTER. JAN-JUN, 2014An experiment was conducted at the experimental field of the farm of Sher-e-Bangla
Agricultural University during the period from May to October, 2014 to study the
effects of different combinations of cowdung (CD) and vermicompost (VC) along
with P and K on BRRI dhan62 using RCBD with three replications. The treatments
were - Control. 'F1 - 100% inorganic fertilizer (IF), T2 —25 % P from + 75% p
from IF. T3 —50 % P from CD + 50% P from IF, 1'4 75 % P from CD + 25% P from
IF. T5 — 25 %Pfrom VC +75%Pfrom IF, T6-50%P from VC± 50%Pfrom IF,
T7 — 75 %P from VC + 25% P from IF. T8— 25% K from CD + 75% K from IF, T950%
K from CD + 50% K from IF. T10— 75% K from CD + 25% K from IF. T11 —25
% K from VC + 75% K from IF, T12 —50% K from VC + 50% K from IF. T13 —75%
K from VC 25% K from IF. Most of the growth and yield parameters differed
significantly due to the combinations of organic and inorganic sources of P and K.
Ilighest plant height. effective tillers bilE', total tillers hill1, longest panicle were
produced by 50% K from VC + 50% K from IF while 50% p each from VC and
produced the highest number of filled grains panicleT The highest grain yield was
obtained from 50% K from VC + 50% K from IF which was statistically similar to
50% p from VC + 50% P from IF. The highest straw yield was observed from 50% P
from VC + 50% P from IF which was statistically similar to 50% K from VC + 50%
K from IF. The highest P and S content in grain was observed from 50% p from VC +
50% p from IF while highest K content in grain was observed from 50% K from VC ±
50% K from IF. The overall results suggest that farmers can be advised to use 50% P
or K from VC and 50% from IF for better growth and nutrient content of BRRI
dhan62 under the agro climatic condition of Sher-e-Bangla Agricultural University
Characterize Dynamic Response of Cantilevers for Measuring Properties of Viscous Fluids
No full textMiniaturized devices are essential to precisely determine the rheological properties of viscous fluid when the available sample volume is inadequate. In this paper, we have attempted to apply the finite element analysis (FEA) method to characterize the dynamic response of a mini cantilever beam to measure the rheological properties of viscous fluid. First, the dynamic response of a mini cantilever beam, partially submerged in viscous fluid, is experimentally measured, and then compared with corresponding FEA solutions. Once the FEA model is validated, further numerical analysis is conducted to investigate how the modal response would change with changing density and viscosity associated with different viscous fluids. The numerical simulations are also repeated with changing the dip-length to investigate the sensitivity analysis. It seems from numerical results that the resonant frequency, Q-factor, time constant and depth of penetration of acoustic wave are dominantly influenced by viscosity of submerged liquid. Results obtained from this study can be used to design the optimized MEMS based test set up for measuring the rheological properties of viscous fluid.
Copyright © 2012 by ASM
Sensitivity Analysis of Planar Piezoresistive Sensors for MEMS Applications
No full textIn this study, the sensitivity of two-dimensional four-terminal piezoresistive sensors commonly referred to as “van der Pauw (VDP)” structure is investigated and analyzed. VDP sensors have the potential to obviate some of the limitations of resistor based sensors such as size and temperature effects. In this study, we will consider the VDP sensor to be fabricated on (100) silicon due to its potential application in MEMS pressure sensors or electronic packaging stress measurements. The sensitivity of the VDP sensor may be affected by misalignment (i.e., orientation) during the etching/diffusion process, the size of the sensor relative to the size of the underlying diaphragm, pad size where the current and voltage are determined, and on their global positions. In this study, we have presented how the VDP stress sensitivity is affected by variations in pad size and sensor orientation with respect to the wafer flat direction. First, a 3D finite element analysis (FEA) model is developed representing a piezoresistive VDP sensor fabricated on (100) silicon diaphragm. Then, the FEA model is validated with the closed form analytical solution for different bi-axial loads. Once the FEA model is validated, additional simulations are conducted to understand the influence of different parameters on the resistance measurements. The change in resistivity of the VDP will then be analyzed to predict its sensitivity under a certain set of sensor parameters.
Copyright © 2016 by ASM
Numerical Analysis to Predict Dynamic Response of Mini Cantilever Beam Partially Submerged in Viscous Fluids
No full textThis research employed the finite element analysis (FEA) method to predict the dynamic response of a mini cantilever beam partially submerged in viscous media. First, the FEA method was validated by comparing the numerical results with corresponding experiments. Then, extensive numerical analyses were performed to investigate the variation of modal response in terms of resonant frequency and Q-factor with changing fluid viscosity and density. The resonant frequency of the beam was found to be reduced with increasing the fluid viscosity and density. The Q-factor was also reduced with increasing fluid viscosity. However, it did not changed significantly by changing fluid density. Numerical analyses were also repeated with varying the depth of beam (one-third, two-third and full) submerged in viscous media. The beam was found to be the most sensitive to respond in resonant frequency and Q-factor when submerged by one-third in viscous media. Results obtained from this numerical study can be used to design the optimized MEMS based test set up for measuring the rheological properties of viscous fluid.
Copyright © 2011 by ASM
- …
