Biological systems routinely produce nanoscopic molecular structures withconsiderably less dispersion in size and shape than encountered in mostmanufactured materials. Indeed, Biological structures are frequently andessentially monodisperse. An example of this uniformity, combined with anintriguing geometry, is the nanometer-scale protein nanorings produced byinteraction of the protein tubulin with certain hydrophobic tri-, tetra- andpentapeptides originally extracted as natural products from marine biosystems.Different peptides produce different sized nanorings, but we focus on thoseproduced by binding to tubulin of the cyclic depsipeptide cryptophycin. Thenanorings that form upon binding of this ligand show a sharp mass distributionindicating that the nanorings are made of 8 tubulin dimers of 100 kDa.

In this submission, we demonstrate how a combination of fluorescence correlationspectroscopy, dynamic light scattering, electron microscopy, analyticalultracentrifugation, small-angle neutron scattering, and modeling is applied toreveal interactions of tubulin and cryptophycin in solution and to characterizetheir structures. We find that the cryptophycin-tubulin nanorings(∼25 nm diameter) are single-walled, appear rigid, are composed of 8tubulin dimers in a single closed ring, and are stable upon dilution tonanomolar concentrations.

Similar studies with a different peptide, the linear pentapeptide dolastatin 10,demonstrated that binding of this peptide to tubulin produces larger nanorings(14 tubulin dimers, ∼45 nm diameter rings), with slightly differentproperties. The ability to adjust the ring size with different peptides, andproduce uniform nanorings with properties that differ slightly between sizeclasses, makes the tubulin-peptide ring structures an appealing structuralsystem.

We demonstrated that an InAs photodiode and a Quantum Dot Infrared Photodiode can be bonded to produce a hybrid broadband infrared photodetector. When cooled to 77 K the InAs photodiode can be used to detect wavelengths from visible to a cutoff wavelength of 3 μm while the Quantum Dot Infrared Photodiode detects wavelengths from 3 to 12 μm. The dark current and spectral response were measured on reference devices and bonded devices. Both sets of devices show similar dark current and spectral response, suggesting that no significant degradation of the devices after the bonding process.

An integrated experimental – simulation – control theory approach designed to enable adaptive control of microstructural evolution in polycrystalline metals is described. A micro-heater array, containing ten addressable channels, is used to create desired temperature profiles across thin polycrystalline films in situ to a scanning electron microscope (SEM). The goal is that on heating with controlled temperature profiles, the evolution of grain growth within the film can be continuously monitored and compared to Monte Carlo simulations of trajectories towards a desired microstructure. Feed-forward and feedback control strategies are then used to guide the microstructure along the desired trajectory.

The motivation of this study is to learn more about the effect of lipid to polymer ratios on the biosensing platform in lipid-based vesicles. Nanoparticles are useful because of their ability to detect cancer in the body with the aid of antibodies. This early detection is crucial in avoiding the rapid spread of tumors. In this study, nanoparticles were synthesized for bio-sensing applications. This was accomplished by combining a long chain lipid (dipalmitoyl-sn-glycero-3-phosphocholine, DPPC) and a short chain lipid (diheptanoyl-sn-glycero-3-phosphocholine, DHPC). After this, the nanoparticles underwent a temperature cycling procedure. Next, the nanoparticles went through a 100nm extrusion filter. This transformed the multilamellar vesicles (MLVs) into unilamellar vesicles (ULVs). The polymer (polypropylene oxide - polyethylene oxide - polypropylene oxide) was then added to the samples, which served as a linker to create a cluster of ULVs. The clustering process was monitored using apparent UV absorption and dynamic light scattering. Dynamic light scattering reflects the hydrodynamic radius of the particle and UV absorption records the change in turbidity. If large clusters are formed, then both the UV absorption and the hydrodynamic radius will increase. Three different polymer to lipid ratios were used: 2.5:1, 1:1, and 0.5:1. The results show that with an increase of polymer to lipid ratios, the aggregation process was facilitated. The nanoparticles were fabricated at the Self-Assembled Functional Nanomaterials (SAFN) lab under the mentorship of Professor Mu-Ping Nieh. The results of this study could provide a more effective way to detect malignant cancer cells in susceptible patients.

A facile technique was adopted to synthesize beautiful lilac bush resembling TiO2-SnO2 microflowers aggregates for photodegradation of Congo Red (CR). The TiO2-SnO2 microflowers in the 2-3 μm range with high surface area (80 m2/g), under optimized conditions of catalyst dosage (0.3 g/L), dye concentration (100 ppm) and pH value is 10, exhibit excellent photocatalytic activity under visible light, whereby, 98.3% of the CR aqueous solution was degraded in 40 min of illumination time and also shows good recyclable photocatalytic activities. Further, the gas sensing properties of the as-synthesized material were evaluated towards detection of a variety of volatile organic compounds, such as acetone, methanol, benzene, ammonia, toluene, diethyl ether, and ethanol.

Oxidation behavior of alumina forming ferritic stainless steel (FeCrAl type stainless steels) grades APM and APMT, which are candidate alloys for fuel cladding, was studied using thermogravimetric analysis under dry air condition, and compared to that of ZIRLO®. In addition to the dry air condition, we also studied the high temperature oxidation behavior of APM and APMT under 100% steam condition in order to compare the effect of environment on the oxidation behavior of these alloys. APM and APMT showed an excellent oxidation resistance at high temperatures compared to ZIRLO® under dry air condition due to a stable Al2O3 oxide scale formed at the surface. Under steam condition, the oxidation rate of APM and APMT was found to be higher compared to that under the dry air condition.

Aluminum alloy 6082 (AA6082) should be a suitable material for use as casings in offshore based sensors due to its mechanical strength and corrosion resistance. However, there is concern with this materials remaining strength after a fire. This paper will discuss the room temperature creep behavior of AA6082 samples after thermal aging at various temperatures. Samples were aged at a constant temperature in the range 373 K to 423 K and for durations ranging from 4 hr to 24 hr. The creep behavior was investigated using loads slightly exceeding the yield strength of aged samples. We propose an empirical model to relate steady state creep rate at room temperature with aging temperature and time. Such empirical relationship can potentially be used in deciding whether AA6082 casings can still be used to carry loads after exposure to elevated temperatures such as platform fires.

The unique and remarkable properties of graphene can be exploited as the basis toa wide range of applications. However, in spite of years of investigations thereare some important graphene properties that are not still fully understood, asfor example, its wettability. There are controversial reported results whethergraphene is really hydrophobic or hydrophilic. In order to address this problemwe have carried out classical molecular dynamics simulations of waternanodroplets shot against graphene surface. Our results show that the contactangle values between the nanodroplets and graphene surfaces depend on theinitial droplet velocity value and these angles can change from 86°(hydrophobic) to 35° (hydrophilic). Our preliminary results indicatethat the graphene wettability can be dependent on spreading liquid dynamics andwhich can explain some of the apparent inconsistencies reported in theliterature.

Nanoparticles have great potential for biomedical applications such as early detection, accurate diagnosis, and personalized treatment of cancer. Assessment of bio-compatibility and toxicity of nanoparticles body is an emerging topic for these applications. To study kinetics of nanoparticles in body, we synthesized indium, gold and platinum nanoparticles in aqueous suspension using pulsed electrical discharge plasmas in water. The average size of synthesized primary nanoparticles for indium, gold, and platinum are 6.2 nm, 6.7 nm, and 5.4 nm, whereas the average size of secondary nanoparticles for indium, gold, and platinum are 315 nm, 72.3 nm, and 151 nm, respectively. Synthesized indium nanoparticles are transported from subcutaneous to serum and brain. The indium content in serum for the synthesized nanoparticles is much higher than that for the In2O3 nanoparticles of 150 nm in primary size. For gold and platinum nanoparticles, preliminary examination of intratracheal administration revealed that administration of synthesized nanoparticles with 10 mg/kg BW (body weight) may cause bleedings and/or emphysema in lung.

Lipid-polymer hybrid nanoparticles (LPHN) have great potential as drug delivery devices for treatment of serious medical issues such as cardiovascular disease, tuberculosis, and cancer. Nanoprecipitation is a commonly used method to synthesize LPHN in a low cost manner. However, this multi-step process proves to be difficult in consistently producing uniformly sized nanoparticles. Here we developed a microfluidic device that utilizes a three-channel pathway and mixer channel to synthesize uniformly sized LPHN in a controlled manner. Dynamic light scattering results of the microfluidic synthesized nanoparticles show decrease in diameter size from 140 nm to 40 nm as the Reynolds number of the channel inflow increases. Transmission electron microscopy confirms the size and morphology of the nanoparticles. Three dimensional structure of the LPHN were observed using atomic force microscopy. The production of higher quality nanoparticles using our microfluidics device can expedite the research and development process of drug delivering lipid polymer nanoparticles.

Study of sorption behavior of radionuclides toward five rock samples drilled in the deep-well R12 in the exocontact zone of Nizhnekansky granitoid massif (“Eniseysky” area) in the range of depth 166 m – 476 m was carried out. The sorption kinetics and Kd values of the long-lived radionuclides of different chemical behavior 137Cs, 226Ra, 79Se, 237+239Np, 239,240Pu, 241,243Am were determined. Experiments were performed under the conditions that are relevant for the future high level waste disposal (atmosphere; composition, pH and Eh of the solutions). Digital radiography demonstrated heterogeneous sorption of all the investigated radionuclides and revealed phases with higher sorption ability. It was established that sorption of metal cations is fast and reaches steady state in a few hours while Se in the form of selenate-ion sorbs insignificantly.

Diamond stands out among single-photon sources due to an intrinsically large band gap, photo-stable emission, room-temperature operation, short excited state lifetimes, and the ability to host hundreds of different color centers. Currently, most of these centers are active in the optical spectrum, but a single-photon source in the infrared would represent a significant advancement. In pursuit of this end, a number of different transition metal atoms have been studied as dopants in the diamond lattice via the GAMESS (General Atomic Molecular and Electronic Structure System) cluster calculation package. The importance of cluster size and electron correlation effects is considered, and excitation energies have been calculated via time-dependent density functional theory.

We considered modification of the defect density of states in CdTe as influenced by a buffer layer in ZnO(ZnS, SnSe)/CdS/CdTe solar cells. Compared to the solar cells employing ZnO buffer layers, implementation of ZnSe and ZnS resulted in the lower net ionized acceptor concentration and the energy shift of the dominant deep trap levels to the midgap of CdTe. The results clearly indicated that the same defect was responsible for the inefficient doping and the formation of recombination centers in CdTe. This observation can be explained taking into account the effect of strain on the electronic properties of the grain boundary interface states in polycrystalline CdTe. In the conditions of strain, interaction of chlorine with the grain boundary point defects can be altered.

Magnetic hyperthermia is a non-invasive cancer treatment method which is usedsynergistically with the current cancer treatments. Improved biocompatibilityand enhanced heating characteristics are the pressing challenges to be addressedin magnetic hyperthermia. Through a novel combinatorial approach, we haveattempted to address both the challenges. Ferrimagneticmagnetite nanoparticles(FMNPs)of size 50 nm were synthesized by thermal decomposition method and wereconverted to hydrophilic phase by 3-Aminopropyltrimethoxysilane (APTMS). SerumAlbumin (SA) from rat was conjugated over the APTMS-FMNPs to convert tobiocompatible phase. The preliminary haemolysis experiments show that SA-FMNPsare non-haemolytic (1.2 % haemolysis). It is observed from the magnetic heatingexperiments that due to better colloidal stability, the Specific Absorption Ratevalue of the SA-FMNPs are higher (2100 W/g) than the FMNPs without SA (1400W/g). Thus we report here that SA conjugation over FMNPs (with a high saturationmagnetization of 75 emu/g) provides a novel combinatorial approach to enhanceboth the biocompatibility and the SAR value for magnetic hyperthermia.

Nano zinc oxide (ZnO) and Calcium doped zinc oxide (CZ) nanopowders were synthesized by sol–gel method from zinc acetate di-hydrate and an adequate quantity of calcium chloride hexa-hydrate. Calcium doped zinc oxide (CZ) were prepared at different Ca concentrations from 1 wt% (CZ1) to 5 wt% (CZ5). The obtained nanopowders were characterized by transmission electron microscopy and X-ray diffraction. The objective of this work is to find a new and highly efficient nanomaterial for the adsorption of heavy metals from waste water. For this reason, the nanopowders were used to uptake heavy metals (Cr, Cd, and Ni) from aqueous solution. The obtained results show that the incorporation of Ca in nanoparticles zinc oxide (ZnO) increases the capacity adsorption of nanopowders and CZ3 is more efficient than the other Ca-doped samples. In this work we studied also the effect of pH and the pyrolysis temperature of the nanopowders on the removal of heavy metal ions from aqueous solution by CZ3.

Plutonium metal is a very unusual element, exhibiting six allotropes at ambient pressure, between room temperature and its melting point, a complicated phase diagram, and a complex electronic structure. Many phases of plutonium metal are unstable with changes in temperature, pressure, chemical additions, or time. This strongly affects structure and properties, and becomes of high importance, particularly when considering effects on structural integrity over long periods of time [1]. This paper presents a time-dependent neutron total scattering study of the local and average structure of naturally aging δ-phase 239Pu-Ga alloys, together with preliminary results on neutron tomography characterization.

Transition metal dichalcogenides (TMDs) are emerging among the potential alternatives to graphene. The monolayer of TMDs can easily be exfoliated mechanically and their electronic properties can also be tuned by controlling the number of layers. TMDs possess an advantage over graphene by controlling band gap magnitude appropriate for the electronic and optoelectronic applications. Here we show, mechanically exfoliated TMDs such as NbSe2 and MoTe2 exhibit metallic and fluctuating conductance behavior respectively. Metallic conduction in NbSe2 was investigated under atmospheric conditions and compered with vacuum conditions. Furthermore, NbSe2 resistance was measured at low temperature up to 5.6 K. The above electronic investigations clearly demonstrate ohmic and fluctuating conduction in NbSe2 and MoTe2 respectively which could be applicable for electronic and optoelectronic devices.