Nanoscience and Nanotechnology Commons^™

Investigating Van Der Waals Josephson Junctions With 2h-Nbse2 And 1t’-Wte2, Kristine Lorraine Haley

UNLV Theses, Dissertations, Professional Papers, and Capstones

Josephson junctions have garnered significant attention due to their unique electronic properties and applications in quantum devices. In this thesis, we investigate the fabrication processes and characterization of two-dimensional (2D) Josephson junctions consisting of layered van der Waals materials: niobium diselenide (2H-NbSe₂) and few layered tungsten ditelluride (1T’-WTe₂). The reduction of dimensionality can bring forth unique characteristics in certain materials that are not seen in their bulk counterparts, making them prime candidates for physical exploration. 2H-NbSe₂ is an s-wave superconductor at temperatures near and below 7 K. 1T’-WTe₂ is a semimetal in bulk but …

Towards Highly Sensitive Capacitance Measurements Of A Quantum Anomalous Hall Phase In Van Der Waal Heterostructures, Kayla Cerminara

UNLV Theses, Dissertations, Professional Papers, and Capstones

One of the pioneering achievements in condensed matter physics of the 20th century is the observation of the quantum Hall e↵ect (QHE) in which the Hall resistance in a two-dimensional (2D) sample takes on quantized values in the presence of a strong perpendicular magnetic field. The precise quantization of the hall resistance to one part in a billion has provided a practical, worldwide resistance standard. A long-standing goal has been to realize a similar state of matter but without the need of a strong quantizing magnetic field. The quantum anomalous Hall e↵ect (QAHE) is such a state that is predicted …

A Performance Guide For Four Songs By Francisco Mignone, Amanda Mara Rizzotto Vidal Pessoa

UNLV Theses, Dissertations, Professional Papers, and Capstones

The scope of this document is to demonstrate the richness and diversity to be found in the art song genre from countries outside of the standard repertoire, specifically focusing on the Brazilian composer Francisco Mignone. The purpose of this document is to provide performance practice guidelines for four selected pieces by Francisco Mignone: No Meio do Caminho (1938), Pregão (1947), Si eu sei o que é saudade (1976), and Valsa-Vocalise (1972). They exemplify expressions of Brazilian national identity through the music selected. Furthermore, it provides a brief background on the composer and his compositional style phases, and context for the …

Degradation Of Antibiotics In Aqueous Phase Using Pms Catalytic Decomposition With Zero-Valent Iron Nanoparticles Immobilized In Sba-15, Ahdee Bluma Zeidman

UNLV Theses, Dissertations, Professional Papers, and Capstones

Zero-valent iron nanoparticles (nZVI) have been studied as an option for soil remediation and water treatment for many years. The capability of nZVI to produce oxidation/reduction processes, depending on the reaction conditions, has attracted great interest with their major drawback being reactivity loss through agglomeration. The loss in nZVI surface area has been reported to be prevented through immobilization onto a porous media (e.g., SBA-15, MCM-41, or zeolites). In this work, a mesoporous silica structure (SBA-15) is used as an nZVI supporting material to enhance its reactivity and promote peroxymonosulfate (PMS) catalytic decomposition for the degradation of antibiotics in aqueous …

Mechanical Characteristics Of Cement Paste In The Presence Of Carbon Nanotubes And Silica Oxide Nanoparticles: An Experimental Study, Moses Karakouzian, Visar Farhangi, Marzieh R. Farani, Alireza Joshaghani, Mehdi Zadehmohamad, Mohammad Ahmadzadeh

Civil and Environmental Engineering and Construction Faculty Research

Considering the remarkable characteristics of nanomaterials, previous research studies investigated the effects of incorporating different types of these materials on improving the concrete properties. However, further studies are required to evaluate the complementary hybridization and synergistic influence of nanomaterials. In this research, the combined effect of adding nano silica particles (NS) and multi-walled carbon nanotubes (MWCNT) on enhancing both the compressive and flexural strengths of the cement paste was investigated. Moreover, the morphology of the interface between cement paste and aggregates was studied by scanning electron microscopy (SEM). The mixtures were prepared using three different portions of MWCNT and NS. …

Diamond-Based Microelectrodes Fabricated Using The Diamond Growth Side For Neural Sensing, Cory Rusinek, Bin Fan, Cort H. Thompson, Monica Setien, Yue Guo, Robert Rechenberg, Yan Gong, Arthur J. Weber, Michael F. Becker, Erin Purcell, Wen Li

Chemistry and Biochemistry Faculty Research

Diamond possesses many favorable properties for biochemical sensors, including biocompatibility, chemical inertness, resistance to biofouling, an extremely wide potential window, and low double-layer capacitance. The hardness of diamond, however, has hindered its applications in neural implants due to the mechanical property mismatch between diamond and soft nervous tissues. Here, we present a flexible, diamond-based microelectrode probe consisting of multichannel boron-doped polycrystalline diamond (BDD) microelectrodes on a soft Parylene C substrate. We developed and optimized a wafer-scale fabrication approach that allows the use of the growth side of the BDD thin film as the sensing surface. Compared to the nucleation surface, …

Buckling Of Blue Phosphorus Nanotubes Under Axial Compression: Insights From Molecular Dynamics Simulations, Shiping Jiang, Huiling Wu, Liangzhi Kou, Chun Tang, Chengyuan Wang, Changfeng Chen

Physics & Astronomy Faculty Research

We report on mechanical properties of blue phosphorus nanotubes (BluePNTs) from systematic molecular dynamics simulations, adopting a Stillinger-Weber potential with parameters determined by fitting to energetic and structural data from first-principles calculations. Our results corroborate the previously reported bending poison effect and size-dependent buckling behaviors. Under axial compression, current simulations predict a shell-to-column buckling mode transition for BluePNTs with increasing aspect ratios; further compression of BluePNTs with large aspect ratios results in a column-to-shell buckling mode transition. Associated critical buckling strains can be described by the continuum mechanics theory. We also simulated buckling behavior of black phosphorus nanotubes (BlackPNTs) and …

Mitigating Accumulation Of Aeolian Dust Particles On Solar Power Generator Panels Without Water, Sanjana Das

UNLV Theses, Dissertations, Professional Papers, and Capstones

Accumulation of dust on solar panels poses a serious problem as it can significantly reduce light absorption and electrical energy output. Several factors affect the dust accumulation such as location, dust properties, wind velocity, system orientation, ambient temperature, humidity, and panel surface properties. Experimental and theoretical studies show that short circuit current and maximum power output of photovoltaic panels reduce approximately linearly with dust concentration. Incidentally, the locations with higher solar energy concentrations are also arid or semi-arid regions with higher dust concentrations. In order to avoid loss in power output, most PV installations perform periodic panel cleaning with water. …

Design, Fabrication And Testing Of Monolithic Low-Power Passive Sigma-Delta Analog-To-Digital Converters, Angsuman Roy

UNLV Theses, Dissertations, Professional Papers, and Capstones

Analog-to-digital converters are critically important in electronic systems. The

difficulty in meeting high performance parameters increases as integrated circuit design

process technologies advance into the deep nanometer region. Sigma-delta analog-todigital

converters are an attractive option to fulfill many data converter requirements.

These data converters offer high performance while relaxing requirements on the precision

of components within an integrated circuit. Despite this, the active integrators found within

sigma-delta analog-to-digital converters present two main challenges. These challenges are

the power consumption of the active amplifier and achieving gain-bandwidth necessary for

sigma-delta data converters in deep nanometer process technologies. Both of these

challenges …

In Vitro Studies Of Gold And Gold Silica Nanoparticle Radiosensitization With Kilovoltage X-Rays, Gregory Colarch

UNLV Theses, Dissertations, Professional Papers, and Capstones

Technological advances in the ability to construct and manipulate nanoscale particles have opened up the possibility of using solid metallic nanoparticles and mixed metal nanoshells as a means to increase dose enhancement and treatment efficacy to tumors. In order for nanoparticles to be an effective form of treatment, they must be delivered to tumors in sufficient concentrations so that there is a dose enhancement factor due to ionizing radiation, as well as being essentially non-toxic to healthy cells. Gold nanoparticles and silica-gold nanoshells fit these requirements. Gold has a high atomic number (Z=79), which gives a larger cross section for …

Transport Properties Of Nano-Silica Contained Self-Consolidating Concrete, Borhan Moradi

UNLV Theses, Dissertations, Professional Papers, and Capstones

In this research study, transport properties of various self-consolidating concretes (SCCs) containing nano-particles (SiO2) were investigated. Nano-silica replaced a portion of the cementitious materials at different replacement levels ranging from 1.5 to 7.5% by weight. For the purpose of this investigation, flow, bulk, and transport properties of SCCs were studied. The investigated transport properties were absorption, water penetration, rapid chloride permeability, capillary absorption, rapid migration, and chloride diffusion. Transport properties of nano-silica SCCs were also compared to those of equivalent silica fume (micro silica) contained concretes, as well as those of control mixture (concrete without nano or micro silica).

Test …

Assessing Different Zeolitic Adsorbents For Their Potential Use In Kr And Xe Separation, Breetha Alagappan

UNLV Theses, Dissertations, Professional Papers, and Capstones

Separation of Kr from Xe is an important problem in spent nuclear fuel fission gas management. The energy intensive and expensive cryogenic distillation method is currently used to separate these gases. In this thesis, we have carried out the research into appropriate sorbents for the separation of Kr and Xe using pressure swing adsorption. We have examined zeolites using gas adsorption studies as they have the potential to be more cost effective than other sorbents. Zeolites are microporous aluminosilicates and have ordered pore structures. The pores in zeolites have extra-framework cations are substantially free to move. The mobility of cations …

Lanthanum Halide Nanoparticle Scintillators For Nuclear Radiation Detection, Paul Guss, Ronald Guise, Ding Yuan, Sanjoy Mukhopadhyay, Robert O’Brien, Daniel Robert Lowe, Zhitao Kang, Hisham Menkara, Vivek V. Nagarkar

Mechanical Engineering Faculty Research

Nanoparticles with sizesscintillators, in order to determine the viability of using scintillators employing nanostructured lanthanum trifluoride. Preliminary results of this investigation are consistent with the idea that these materials have an intrinsic response to nuclear radiation that may be correlated to the energy of the incident radiation.

Transparent Actuator Made With Few Layer Graphene Electrode And Dielectric Elastomer, For Variable Focus Lens, Taeseon Hwang, Hyeok-Yong Kwon, Joon-Suk Oh, Jung-Pyo Hong, Seung-Chul Hong, Youngkwan Lee, Hyouk Ryeo Choi, Kwang J. Kim, Mainul Hossain Bhuiya, Jae Do Nam

Mechanical Engineering Faculty Research

A transparent dielectric elastomer actuator driven by few-layer-graphene (FLG) electrode was experimentally investigated. The electrodes were made of graphene, which was dispersed inN-methyl-pyrrolidone. The transparent actuator was fabricated from developed FLG electrodes.The FLG electrode with its sheet resistance of 0.45 kΩ/sq (80 nm thick) was implemented to mask silicone elastomer. The developed FLG-driven actuator exhibited an optical transparency of over 57% at a wavenumber of 600 nm and produced bending displacement performance ranging from 29 to 946 μm as functions of frequency and voltage. The focus variation was clearly demonstrated under actuation to study its application-feasibility in …

Synthesis And Characterizations Of Pyridinium Salts Including Poly(Pyridinium Salt)S And Their Applications, Tae Soo Jo

UNLV Theses, Dissertations, Professional Papers, and Capstones

Pyridinium salts, both molecular and polymeric, are an interesting class of multifunctional materials that exhibit liquid-crystalline and light-emitting properties. Moreover, their properties can be easily tuned by introducing new types of anions or by modifying their chemical structures. This dissertation describes synthesis and characterization of poly(pyridinium salt)s containing macrocounterions and fluorene moieties in their backbones, synthesis and characterization of nanocomposites of poly(pyridinium salt)s with single-walled carbon nanotubes via non-covalent interactions, and synthesis and characterizations of pyridinium salts having different aliphatic linkages and their application in organic acid sensing.

First, all of these ionic polymers were prepared by either ring-transmutation or …

Seismic Characterization Of Select Engineered Nanoparticles In Essentially Saturated Glass Beads, Mohamed Nihad Rajabdeen

UNLV Theses, Dissertations, Professional Papers, and Capstones

A laboratory testing apparatus was developed for the study of seismic body wave propagation through nanoparticles dispersed in pore fluid that is essentially saturating glass beads. First, the responses of water-saturated glass bead specimens were studied to establish baseline signatures. Then the seismic responses in the presence of engineered nanoparticles of various concentrations dispersed in the pore fluid of the specimen chamber were studied to observe variances from baseline.

The testing apparatus incorporates piezoceramic bender elements to actuate and receive seismic body waves through a cylindrical column filled with glass beads and back-saturated at ambient pressure with liquid. The system …

Self-Assembling Organic Semiconductors With Tunable Electronic Properties Based On Novel Asymmetric Phenazine And Bisphenazine, Kyoungmi Jang

UNLV Theses, Dissertations, Professional Papers, and Capstones

Current demands in the area of organic semiconductors focus on both electronic and self-assembling properties. Particularly, one-dimensionally grown nanostructures of small organic semiconductors have drawn much attention for nanodevice fabrication. Self-assembly through various intermolecular interactions has been widely used to produce one-dimensionally grown nanostructures which can be induced by various methods such as rapid solution dispersion, a phase transfer method, vapor annealing, crystallization, and organogelation in conjunction with proper molecular design. Controlling the morphology of the nanostructures plays an important role in achieving desirable properties in optoelectronic device applications. While significant advancements have been made in developing molecular architectures for …

Optical And Raman Characterization Of Ald Alumina Coated Multiwall Carbon Nanotubes And Nanoporous Gold Film, Naod Belai

UNLV Theses, Dissertations, Professional Papers, and Capstones

Due to their large surface to volume ratio nanostructures are inherently unstable. To insure long term stability of nano-devices, they have to be rendered inert to their environment. In this study, nanoporous gold films(NPGF) and multiwall carbon nanotubes were coated with ALD alumina of varying thicknesses. Subsequently, the plasmonic property of the former and electronic property of the latter was monitored by Transmittance and Raman Spectroscopy respectively. Transmittance spectra revealed that NPGF passivated by ALD-alumina maintains its plasmonic properties, i.e. its LSPR supporting properties remained intact. Raman spectra of ALD alumina passivated MWNTs show no coating induced changes in its …

Investigation Of Structural And Magnetic Properties Of Iron Clusters Encapsulated In Carbon, Andrew Mohrland, Eunja Kim, Phillipe Weck, Pang Tao, Kenneth Czerwinski

Festival of Communities: UG Symposium (Posters)

Our goal is to investigate and predict the properties of iron-carbon nanostructures by performing numerical calculations using the density-functional theory. We are interested in which nanostructures are most stable, and in how they are likely to form. We have a particular interest in the magnetic properties of carbon "buckyballs" containing iron particles. These structures have potential for biomedical application, including use in anti-cancer treatment. Lone iron clusters have potential for use as a catalyst designed to reduce vehicle emissions.

Computational Study Of Carbon Nanotubes Under Strain, Jeremy Feliciano, William Wolfs

Festival of Communities: UG Symposium (Posters)

We perform computational studies of carbon nanotubes (CNTs) using molecular dynamics simulations to examine the behavior of single-walled (SW) and multiwalled (MW) CNTs under large compressive and bending strains. We study the effects of defects, heating and chirality on their properties. Research on CNTs holds great promise for developing new advanced materials in applications ranging from high-strength composites to next-generation electronics.

Streaming Potential Generated By A Pressure-Driven Flow Over Superhydrophobic Stripes, Hui Zhao

Mechanical Engineering Faculty Research

The streaming potential generated by a pressure-driven flow over a weakly charged slip-stick surface [the zeta potential of the surface is smaller than the thermal potential (25 mV)] with an arbitrary double layer thickness is theoretically studied by solving the Debye–Huckel equation and Stokes equation. A series solution of the streaming potential is derived. Approximate expressions for the streaming potential in the limits of thin double layers and thick double layers are also given in excellent agreement with the full solution. To understand the impact of the slip, the streaming potential is compared against that over a homogeneously charged smooth …

Fabrication, Characterization And Simulation Of Non-Lithographic Nanostructures And Their Potential Applications, Neelanjan Bhattacharya

UNLV Theses, Dissertations, Professional Papers, and Capstones

The dissertation describes the formation of porous silicon through the pores of porous alumina on a silicon substrate. Porous silicon, by itself, is inherently a non-uniform material that has non-uniform optical and electronic properties. In addition, it is also mechanically fragile material requiring careful material handling. The porous silicon fabricated through the nanosized pores of porous alumina are expected to mitigate these problems, thereby enhancing commercial viability of the device. The porous silicon as well the porous alumina have been synthesized through anodisation for various parameters and also various types of anodizing electrolytes. The porous silicon, so obtained have been …

Macrophages Loaded With Gold Nanoshells For Photothermal Ablation Of Glioma: An In Vitro Model, Amani Riad Makkouk

UNLV Theses, Dissertations, Professional Papers, and Capstones

The current median survival of patients with glioblastoma multiforme (GBM), the most common type of glioma, remains at 14.6 months despite multimodal treatments (surgery, radiotherapy and chemotherapy). This research aims to study the feasibility of photothermal ablation of glioma using gold nanoshells that are heated upon laser irradiation at their resonance wavelength. The novelty of our approach lies in improving nanoshell tumor delivery by loading them in macrophages, which are known to be recruited to gliomas via tumor-released chemoattractive agents. Ferumoxides, superparamagnetic iron oxide (SPIO) nanoparticles, are needed as an additional macrophage load in order to visualize macrophage accumulation in …

On The Effect Of Hydrodynamic Slip On The Polarization Of A Nonconducting Spherical Particle In An Alternating Electric Field, Hui Zhao

Mechanical Engineering Faculty Research

The polarization of a charged, dielectric, spherical particle with a hydrodynamically slipping surface under the influence of a uniform alternating electric field is studied by solving the standard model (the Poisson–Nernst–Planck equations). The dipole moment characterizing the strength of the polarization is computed as a function of the double layer thickness, the electric field frequency, the particle’s surface charge, and the slip length. Our studies reveal that two processes contribute to the dipole moment: ion transport inside the double layer driven by the electric field and the particle’s electrophoretic motion. The hydrodynamic slip will simultaneously impact both processes. In the …

Giant Raman Enhancement On Nanoporous Gold Film By Conjugating With Nanoparticles For Single-Molecule Detection, Lihua Qian, Biswajit Das, Yan Li, Zhilin Yang

Electrical & Computer Engineering Faculty Research

Hot spots have the contradictively geometrical requirements for both the narrowest interstices to provide strong near-field coupling, and sufficient space to allow entrance of the analytes. Herein, a two-step method is employed to create hot spots within hybrid nanostructures, which consist of self-supported nanoporous gold films with the absorbed probes and subsequent nanoparticle conjugates without surface agents or mechanical motion. The molecules confined into 1 nm interstice exhibit 2.9 × 10⁷ times enhancement in Raman scattering compared to pure nanoporous gold. Giant enhancement primarily results from strong near-field coupling between nanopore and nanoparticle, which is theoretically confirmed by finite-difference …

Modulated Nanopores Using Pulse Anodization On Thin Aluminum, Mahesh Babu Gunukula

UNLV Theses, Dissertations, Professional Papers, and Capstones

Nanoporous anodic aluminum oxide has traditionally been made in one of two ways: "Mild Anodization (MA)" or "Hard Anodization (HA)". The former method produces self-ordered pore structures but it is slow and only works for a narrow range of processing conditions; the latter method, which is widely used in the aluminum industry, is faster but it produces films with disordered pore structures. Here we report a novel approach termed "pulse anodization" that combines the advantages of the MA and HA processes. By designing the pulse sequences it is possible to control both the composition and pore structure of the anodic …

Magnetic Sensors For Biodetection, Pranjali Vineet Sneha Deshpande

UNLV Theses, Dissertations, Professional Papers, and Capstones

The objective of thesis is to design magnetic sensor for detection of nanoparticles. Recently integrating the standard laboratory techniques into integrated system on chip is growing attention. Recent development is to combine magnetic markers and magnetoresistive sensors together in magnetic chip. In this thesis two magnetoresistive sensors were studied and designed.

By applying magnetic fields, magnetic nanoparticles can be manipulated on-chip, which can be utilized to pull the molecules to specific binding sites or to test the binding strength and distinguish between specifically and non-specifically bound molecules

Magnetoresistive sensors are compatible with the semiconductor industry which provides electronic signal directly …

Metal Induced Crystallization Of Silicon Thin Films, Sandeep Kumar Raju Sangaraju

UNLV Theses, Dissertations, Professional Papers, and Capstones

Low temperature crystallization of thin film silicon is important for many industrial applications including flat panel displays and silicon thin film solar cells. Unfortunately this remains a major challenge since crystallization temperature of silicon is above 1,000 degrees Celsius, thus limiting to substrates that can tolerate high temperatures. The inability to deposit crystalline thin films on glass substrates is the reason why flat panel display industry uses amorphous silicon for LCD active matrix displays. Thus the ability to deposit crystallized thin film silicon at low temperatures will have significant impact on thin film silicon applications. It has been observed that …

Research On The Transport And Deposition Of Nanoparticles In A Rotating Curved Pipe, Jianzhong Lin, Peifeng Lin, Huajun Chen

Mechanical Engineering Faculty Research

A finite-volume code and the SIMPLE scheme are used to study the transport and deposition of nanoparticles in a rotating curved pipe for different angular velocities, Dean numbers, and Schmidt numbers. The results show that when the Schmidt number is small, the nanoparticle distributions are mostly determined by the axial velocity. When the Schmidt number is many orders of magnitude larger than 1, the secondary flow will dominate the nanoparticle distribution. When the pipe corotates, the distribution of nanoparticle mass fraction is similar to that for the stationary case. There is a “hot spot” deposition region near the outside edge …

Substituent Effect On The Electronic And Assembling Properties Of Asymmetric Phenazine Derivatives, Bin Cao

UNLV Theses, Dissertations, Professional Papers, and Capstones

Currently, one-dimensional (1-D) nanostructures have drawn much interest because of their potential applications for nanoscale optoelectronic devices. Self-assembly (SA) based on π-conjugated systems through various intermolecular interactions has been widely used to produce 1-D nanostructure. Morphology of the assembled structures can be modified by incorporating substituents, which provide additional secondary interactions. Meanwhile, those substituents also influence the electronic properties of the molecules. Previous studies have made little effort to systematically study subsistent effects on both electronic and SA properties.

The primary objective of this research is to generate controllable 1-D structures through SA, and to provide a fundamental understanding of …