The design of interface elements in geotechnical engineering traditionally involves empiricism and lacks a solid fundamental underpinning based on the controlling mechanisms. These design shortcomings exist due to deficiencies in the fundamental understanding of geotechnical interface behaviors and the lack of test methods and devices available to directly measure interface properties in situ. The current work strives to improve the state of geotechnical knowledge and design with regard to interface behavior through fundamental laboratory studies and the development and use of a new in situ testing device. The current investigations are focused across a range of scales from micromechanical interactions to full scale field implementation. A series of laboratory investigations at the micromechanical level have been performed, specifically aimed at investigating the mechanisms controlling granular interactions against conventional and textured friction sleeves, and hook and loop type interactions present within textured geomembrane - geotextile systems. Additionally, a new in situ testing device has been designed and developed, the Multi Piezo Friction Attachment (MPFA), to allow for the characterization of geotechnical interface properties in situ within the context of an effective stress framework. The MPFA simultaneously provides four independent measures of interface friction (f

The failure behavior of collagenous soft tissues is important for clinical problems of plaque rupture and trauma. Cyclic tests require high frequencies that may affect the strength properties of the soft tissues. Experimental results of mechanical response of blood vessels to physiologic loads can be used to model and predict plaque rupture and direct medical therapy or surgical intervention. The goal of the study is to measure the mechanical failure properties of arteries to determine if they are strain rate and cycle dependant and to measure the progressive damage of arteries with time dependent loading. Ring specimens of porcine carotid arteries were preconditioned and then pulled to failure. In all cases, the intima broke first. Ultimate stress increased as a weak function of increasing strain rates. The ultimate stress at 100 mm/s was 4.54 MPa, greater than the 3.26 MPa at 0.1 mm/s. Strain rates between 1 and 100 mm/s correspond to a cyclic frequency of 0.5 Hz to 5 Hz for fatigue testing. In contrast, ultimate strain in arteries was independent of strain rate over the range tested. The creep tests showed a logarithmic relationship between stress magnitude and stress duration for this soft tissue. The creep testing indicates that damage is accumulating above certain threshold stress levels. The values of ultimate strength showed a 35% increase after 10,000 cycling loading. In contrast, the ultimate strain had a 13% decrease after cycling and the difference was statistically significant with p=0.018. The testing results showed that there were no significant differences on strength among fresh arteries and arteries stored at 5¡ã C for up to two weeks. The test results may be useful for developing a mathematical model to predict the behavior of arterial soft tissues and may be extended to estimate fracture and fatigue in the atherosclerotic plaque cap.

This research is to synthesize PANI (polyaniline) thin film for polymer organic solar cells as a hole transport layer on the top of ITO substrate by using electrochemical (cyclic voltammetry) method. The device structure is ITO (150 nm) / PANI (50 nm) / P3HT: PCBM (100 nm) / Al (200 nm). We investigated surface morphology, conductivity, and light transmission of the PANI thin film from different aniline monomer concentration and studied the factors on device efficiency, also compared with the device structured with hole transport layer PEDOT:PSS. In this study, we found PANI thin films synthesized with different aniline monomer concentration, their light transmission over 80% at the range of 450 nm ~ 650nm wavelength and the conductivity up to 0.6 S/cm. It shows that PANI thin film suitably act as hole transport layer. In addition, we found morphology of PANI thin film that varied with different aniline monomer concentration. The power conversion efficiency of the device mainly affected by morphology with different aniline monomer concentration. Comparing to other parameters of concentration, the 0.3M aniline monomer concentration polymerized PANI thin film owned the most appropriate surface morphology, and the power conversion efficiency up to 1.76%.

In this study, WO3 and NiO thin films were deposited on the ITO/Glass substrates by radio frequency (RF) magnetron sputtering, respectively. The physical and electrochromic properties of thin films were investigated. On the other hand, the lithium perchlorate (LiClO4) powder was dispersed in propylene carbonate (PC) solvent to complete 1 M electrolyte. Then, as the 4.5 wt.% of ethyl cellulose and 8 wt.% ethylene carbonate (EC) were added to this electrolyte under stirring, a gel polymer electrolyte (GPE) was formed. Finally, the WO3 and NiO thin films obtained with the optimal deposition parameters were combined with the GPE to set up a complementary electrochromic device (CECD). The effects of the various coloring voltages on the electrochromic properties of CECD are investigated. The memory effect, energy-saving efficient, response time and switch lifetime of CECD are also estimated and discussed. Experimental results reveal that the amorphous thin films can be obtained with the RF power of 100 W and oxygen concentration of 60% at room temperature (RT). The thicknesses of WO3 and NiO films were approximately 530 nm and 180 nm, respectively. The stoichiometric of thin films were 2.99 for O/W ratio and 1.01 for O/Ni ratio. The GPE [(1 M LiClO4+PC)+ethyl cellulose(4.5 wt.%)+EC(8 wt.%)] exhibits a viscosity coefficient of 100 mPa∙s, a maximum ion conductivity (£m) of 7.17 mS/cm, a minimum activation energy (Ea) of 0.033 eV and a average visible transmittance of 82% at RT. The optimal electrochromic CECD (Glass/ITO/WO3/GPE/NiO/ITO/Glass) biased with a coloring/bleaching voltage of ¡Ó2.2 V revealed a transmittance variation (£GT%) of 54.53%, an optical density change (£GOD) of 0.790, an intercalation charge (Q) of 6.28 mC/cm2 and a coloration efficiency (£b) of 125.21 cm2/C at a wavelength (£f) of 550 nm. The chromaticity coordinates of CECD were x=0.289 and y=0.365 under the colored state. In addition, the energy-saving efficient of CECD was 15.19 W/V-m2 over the wavelength range between 380 nm and 780 nm. Also, it presented an open-circuit memory effect that the colored transmittance (£f at 550 nm) was 18.9% in 24 h. The total response time of the CECD was about 4 s for coloring and bleaching steps. After the repeated switch of 1,000 times, the £GT% of CECD was 43.57%. In this study, WO3 and NiO thin films with good adhesion, amorphous, and nearly stoichiometric were successfully deposited by RF sputter. Furthermore, high £m and high transmittance of GPE can be prepared easily and inexpensively. Our results demonstrated that the CECD exhibited the advantages of low applied voltage, high £b, fast response time and long-term memory characteristics.

Verapamil is a commonly used medicine for the treatment of supraventricular arrhythmias, angina and hypertension. Recently, some newly developed applications of Verapamil, such as treating hypomania and chemotherapy for cancers, have been reported. Thus, monitoring the concentration of Verapamil accurately is very important. The major clinical analytical methods of Verapamil concentration determination are high performance liquid chromatography (HPLC) with UV or with fluorescence detector. However, these analytical methods have some disadvantages, like expensive instruments, complex operation, and time-consuming etc. The chemical structure and properties of Verapamil are very stable. The preliminary result of electrochemical analysis doesn¡¦t show any electrochemical activity. In this study, we developed an innovative ozone pre-treatment method to oxidize Verapamil to the smaller molecules and change its structure. Verapamil have excellent electrochemical activity after ozone pre-treatment. The spectroscopy and mass spectrometry show the changes of Verapamil structure. The products of Verapamil treated with ozone are also predicted by mass spectrometry. The gold nanoelectrode ensemble electrodes (GNEE) are used as working electrode for its good catalytic activity of electrochemical reaction, high sensitivity and high selectivity. The overall experimental framework of this study is microchip with GNEE working electrode accompanied by cyclic voltammetry, an electrochemical analytical instrument. Compared with traditional analytical methods, the system has some advantages such as small size, micro sample volume, easy operation, rapid detection and low cost. The limit concentration of Verapamil solution for stable detection in the system is 10 ng/mL. A linear dynamic range with a high correlation factor from 10 ng/mL to 100 £gg/mL was obtained. For the analysis of serum sample, Verapamil present excellent electrochemical activity at 1 ng/mL. A linear dynamic range with a high correlation factor from 1 ng/mL to 100 £gg/mLwas obtained. According to the results, our system for clinical Verapmil concentration analysis has the feasibility of the practical application.

Epidemiologic data suggest that soy consumption may protect against cancer induction in several tissues in humans, including urothelial carcinoma. Genistein have been reported to regulate genes that are involved in several cellular events. However, the molecular mechanism of genistein -induced upregulation of epithelial membrane protein 2 (EMP2), candidate urothelial tumor suppressor, is not entirely understood. At first, we found that the mRNA and protein expression levels of EMP2 were significantly greater in the normal urothelial tissues and human urothelial cells than those in urothelial bladder carcinoma tissues and urothelial cell carcinoma-derived cell lines. Second, EMP2 knockdown via RNA interference markedly enhanced cell proliferation, colony formation, migration and invasiveness. By contrast, EMP2 overexpression suppressed these malignant behaviors. Third, we showed that genistein-induced inhibition in cell proliferation is associated with an increase in EMP2 expression. Using various deleted EMP2 promoter constructs, we defined that the EMP2 core promoter is enough to observe the genistein-induced upregulation of EMP2 transcriptional activity. Using site direct mutagenesis and chromatin immunoprecipitation assays demonstrated that cyclic-AMP response element binding protein 1 (CREB1) acts as a positive regulator of EMP2 transcription by directly binding to its promoter. These results showed EMP2 suppressed urothelial cell carcinoma-derived cell growth, motility and invasion and for the first time that genistein promoted EMP2 expression in urothelial cell carcinoma-derived cells by inducing EMP2 transcriptional activity via CREB1 binding.

The cytoskeleton is a diverse, multi-protein framework that plays a fundamental role in many cellular activities including mitosis, cell division, intracellular transport, cell motility, muscle contraction, and the regulation of cell polarity and organization. Furthermore, cytoskeletal filaments have been implicated in the pathogenesis of a wide variety of diseases including cancer, blood disease, cardiovascular disease, inflammatory disease, neurodegenerative disease, and problems with skin, nail, cornea, hair, liver and colon. Increasing evidence suggests that the distribution and organization of the cytoskeleton in living cells are affected by mechanical stresses and the cytoskeleton determines cell stiffness. We developed a fully nonlinear, constrained mixture model for adherent cells that allows one to account separately for the contributions of the primary structural constituents of the cytoskeleton and extended a prior solution from the finite elasticity literature for use in a sub-class of atomic force microscopy (AFM) studies of cell mechanics. The model showed that the degree of substrate stretch and the geometry of the AFM tip dramatically affect the measured cell stiffness. Consistent with previous studies, the model showed that disruption of the actin filaments can reduce the stiffness substantially, whereas there can be little contribution to the overall cell stiffness by the microtubules or intermediate filaments. To investigate the effect of mechanical stretching on cytoskeletal remodeling and cell stiffness, we developed a simple cell-stretching device that can be combined with an AFM and confocal microscopy. Results demonstrate that cyclic stretching significantly and rapidly alters both cell stiffness and focal adhesion associated vinculin and paxillin, suggesting that focal adhesion remodeling plays a critical role in cell stiffness by recruiting and anchoring F-actin. Finally, we estimated cytoskeletal remodeling by synthesizing data on stretch-induced dynamic changes in cell stiffness and focal adhesion area using constrained mixture approach. Results suggest that the acute increase in stiffness in response to an increased cyclic stretch was probably due to an increased stretch of the original filaments whereas the subsequent decrease back towards normalcy was consistent with a replacement of the highly stretched original filaments with less stretched new filaments.

Shape memory alloys (SMAs) are an important class of smart materials that have the ability to remember a shape. Current practical uses of SMAs are limited to below 100 degrees C which is the limit for the transformation temperatures of most commercially successful SMAs such as NiTi and Cu-based alloys. In recent years, the CoNiGa system has emerged as a new ferromagnetic shape memory alloy with some compositions exhibiting high martensitic transformation temperatures which makes CoNiGa a potential high temperature shape memory alloy (HTSMA). In this study, the microstructural evolution and martensitic transformation characteristics of CoNiGa (mainly Co46Ni27Ga27 and Co44Ni26Ga30 in at.percent) HTSMAs were investigated in as-cast and hot-rolled conditions as a function of different heat treatments. Heat treatment conditions were selected to introduce single, two, and three phase structures, where two precipitate phases (ductile Y and hard Y') do not martensitically transform. Calorimetry, X-ray analysis, scanning and transmission electron microscopy, thermo-mechanical process and cycling techniques are applied to understand the structural and chemical factors influencing the thermal stability and transformation characteristics. The main findings include improvement of ductility, most cyclically stable compositions with narrow transformation hysteresis (<40 degrees C) and transformation temperatures in the range of 100 degrees C to 250 degrees C, formation of new phases and their effects, and associated compositional changes in the matrix, on the transformation temperatures and on the microstructural evolution. In addition, Ms temperature depends linearly on the valence electron concentration (e/a) of the matrix, only if the Ga content is constant, and the samples with narrow transformation hysteresis demonstrate reversible martensitic transformation in constant-stress thermal cycling experiments.

Escherichia coli is the best characterized bacterium; it grows rapidly, and it is easy to manipulate genetically. An increased knowledge about the physiology of this model organism will facilitate the development of engineered E.coli strains for applications such as production of biofuels and biofilm control. The aims of this work were the application of protein engineering to increase E. coli hydrogen production, the identification of the proteins regulating extracellular DNA production (eDNA), and the evaluation of the effect of the proteins synthesizing the signal 3'-5'-cyclic diguanylic acid (c-di-GMP) on biofilm formation. The Escherichia coli hydrogen production rate was increased 9 fold through random mutagenesis of fhlA. Variant FhlA133 (Q11H, L14V, Y177F, K245R, M288K, and I342F) enhances hydrogen production by increasing transcription of the four transcriptional units regulated by FhlA. The amino acid replacements E363G and L14G in FhlA increased hydrogen production 6 fold and 4 fold, respectively. The complete E. coli genome was screened to identify proteins that affect eDNA production. The nlpI, yfeC, and rna mutants increased eDNA production and the hns and rfaD mutants decreased eDNA production. Deletion of nlpI increases eDNA 3 fold while overexpression of nlpI decreases eDNA 16 fold. Global regulator H-NS is required for eDNA with E. coli since deletion of hns abolished eDNA production while overexpression of hns restored eDNA to 70 percent of the wild-type levels. Our results suggest that eDNA production in E. coli is related to direct secretion. Deletions of the genes encoding the diguanylate cyclases YeaI, YedQ, and YfiN increased swimming motility and eDNA as expected for low c-di-GMP levels. However, contrary to the current paradigm, early biofilm formation increased dramatically for the yeaI (30 fold), yedQ (12 fold), and yfiN (18 fold) mutants. Hence, our results suggest that c-di-GMP levels should be reduced for initial biofilm formation because motility is important for initial attachment to a surface.

The thesis aims to develop an ISFET chip compatible miniaturized planar reference. Such planar reference electrode will be constructed by: silica / silica oxide / titanium / palladium / silver / silver chloride / saturated KCl agar / silica nitride / silica. For the size of the reference electrode is only 10mm (length), 5mm (width) and 1mm (height), which is diminished of hundred-fold to the traditional reference electrode. In addition to develop the fabrication techniques of the electrodes, this thesis will be devoted to systematic measuring and analyzing their stability, AC impedence, cyclic voltammery and electrochemical noise characteristics. The results show that the stability is inside 1mV, offset voltage is about -9 mV and the resistance of AC impedence is 400