Optical Engineering Of Iii-Nitride Nanowire Light-Emitting Diodes And Applications,
2021
New Jersey Institute of Technology
Optical Engineering Of Iii-Nitride Nanowire Light-Emitting Diodes And Applications, Ha Quoc Thang Bui
Dissertations
Applications of III-nitride nanowires are intensively explored in different emerging technologies including light-emitting diodes (LEDs), laser diodes, photodiodes, biosensors, and solar cells. The synthesis of the III-nitride nanowires by molecular beam epitaxy (MBE) is investigated with significant achievements. III-nitride nanowires can be grown on dissimilar substrates i.e., silicon with nearly dislocation free due to the effective strain relaxation. III-nitride nanowires, therefore, are perfectly suited for high performance light emitters for cost-effective fabrication of the advanced photonic-electronic integrated platforms. This dissertation addresses the design, fabrication, and characterization of III-nitride nanowire full-color micro-LED (µLED) on silicon substrates for µLED display technologies, high-efficient …
Intermittent Dynamics Of Dense Particulate Matter,
2021
New Jersey Institute of Technology
Intermittent Dynamics Of Dense Particulate Matter, Chao Cheng
Dissertations
Granular particle systems are scattered around the universe, and they can behave like solids when there exist strong force-bearing networks, so that the granular system can resist certain stress without deformation. When such a network is not present, particles yield to small stress and behave like a fluid. A wide range of systems exhibit intermittent dynamics as they are slowly loaded, with different dynamical regimes governing many industrial and natural phenomena. While a significant amount of research on exploring intermittent dynamics of granular systems has been carried out, not much is known about the connection between particle-scale response and the …
Investigation Of Topological Phonons In Discrete Mechanical Metamaterials,
2021
New Jersey Institute of Technology
Investigation Of Topological Phonons In Discrete Mechanical Metamaterials, Kai Qian
Dissertations
The study of topological mechanical metamaterials is a new emerging field that focuses on the topological properties of artificial mechanical structures. Inspired by topological insulators, topological mechanism has attracted intensive attention in condensed matter physics and successfully connected the quantum mechanical descriptions of electrons with the classical descriptions of phonons. It has led to experiments of mechanical metamaterials possessing topological characteristics, such as topologically protected conducting edges or surfaces without back-scattering. This dissertation presents a new experimental approach for mechanically engineering topological metamaterials based on patterning magnetically coupled spinners in order to localize the propagation of vibrations and evaluate different …
Uavs For Vegetation Monitoring: Overview And Recent
Scientific Contributions,
2021
National Agricultural and Food Research and Technology Institute-INIA
Uavs For Vegetation Monitoring: Overview And Recent Scientific Contributions, Ana I. De Castro, Yeyin Shi, Joe Mari Maja, Jose M. Pena
Department of Mechanical and Materials Engineering: Faculty Publications
This paper reviewed a set of twenty-one original and innovative papers included in a special issue on UAVs for vegetation monitoring, which proposed new methods and techniques applied to diverse agricultural and forestry scenarios. Three general categories were considered: (1) sensors and vegetation indices used, (2) technological goals pursued, and (3) agroforestry applications. Some investigations focused on issues related to UAV flight operations, spatial resolution requirements, and computation and data analytics, while others studied the ability of UAVs for characterizing relevant vegetation features (mainly canopy cover and crop height) or for detecting different plant/crop stressors, such as nutrient content/deficiencies, water …
Three-Dimensional Shape Analysis Of
Peripapillary Retinal Pigment Epithelium-Basement Membrane Layer Based On Oct
Radial Images,
2021
University of Nebraska - Lincoln
Three-Dimensional Shape Analysis Of Peripapillary Retinal Pigment Epithelium-Basement Membrane Layer Based On Oct Radial Images, Junfei Tong, Pengfei Dong, Sachin Kedar, Deepta Ghate, Linxia Gu
Department of Mechanical and Materials Engineering: Faculty Publications
The peripapillary retinal pigment epithelium-basement membrane (ppRPE/BM) layer angle was recently proposed as a potential index for estimating intracranial pressure noninvasively. However, the ppRPE/BM layer angle, measured from the optical coherence tomography (OCT) scans, varied across the radial directions of the optic disc. This made the ppRPE/BM layer angle difficult to be utilized in its full potential. In this study, we developed a mathematical model to quantify the ppRPE/BM layer angles across radial scans in relation to the ppRPE/BM 3D morphology in terms of its 3D angle and scanning tilt angles. Results showed that the variations of the ppRPE/BM layer …
On The Comparison Of Flow Physics Between Minimal And
Extended Flow Units In Turbulent Channels,
2021
University of Nebraska-Lincoln
On The Comparison Of Flow Physics Between Minimal And Extended Flow Units In Turbulent Channels, Ethan A. Davis, Siamak Mirfendereski, Jae Sung Park
Department of Mechanical and Materials Engineering: Faculty Publications
Direct numerical simulations were performed to study the effects of the domain size of a minimal flow unit (MFU) and its inherent periodic boundary conditions on flow physics of a turbulent channel flow in a range of 200 ≤ Reτ ≤ 1000. This was accomplished by comparing turbulent statistics with those computed in sub-domains (SD) of extended domain simulations. The dimensions of the MFU and SD were matched, and SD dynamics were set to minimize artificial periodicities. Streamwise and spanwise dimensions of healthy MFUs were found to increase linearly with Reynolds number. It was also found that both MFU …
Understanding Of Aerosol Transmission Of Covid 19 In Indoor Environment - Part 2: Approaches To Mitigation,
2021
CUNY New York City College of Technology
Understanding Of Aerosol Transmission Of Covid 19 In Indoor Environment - Part 2: Approaches To Mitigation, Adama Barro, Cathal O'Toole, Jacob S. Lopez, Matthew Quinones, Sherene Moore
Publications and Research
The challenge we face in implementing solutions for new HVAC ventilation and filtration design, is to effectively improve air quality for virus mitigation without losing performance efficiency. The purpose of this improvement is to decontaminate the occupied enclosed areas, reducing the transmission of the corona virus aerosol transmission. Our research seeks reliable approaches to mitigate the further spread of aerosol transmission in indoor spaces. The methodology is to examine innovative HVAC engineering solutions that combat epidemiological problems of Covid-19 for the post-pandemic era, by researching scholarly articles and ASHRAE journals. We are achieving the goal of finding highly efficient resolutions …
Mixed Mode Crack Propagation In Iliac Bone,
2021
University of Nebraska-Lincoln
Mixed Mode Crack Propagation In Iliac Bone, E. Baesu, Dm. Iliescu, Bv. Radoiu, S. Halichidis
Department of Mechanical and Materials Engineering: Faculty Publications
Bone is a complex material that can be regarded as an anisotropic elastic composite material. The problem of crack propagation in hu- man bone is analyzed by using a generalization of the maximum tensile stress criterion (MTS). The results concern the critical stress for crack propagation and the direction of the crack path in Iliac bone.
Special Issue “Cfd Modeling Of Complex Chemical Processes:
Multiscale And Multiphysics Challenges”,
2021
McMaster University
Special Issue “Cfd Modeling Of Complex Chemical Processes: Multiscale And Multiphysics Challenges”, Li Xi, De-Wei Yin, Jae Sung Park
Department of Mechanical and Materials Engineering: Faculty Publications
No abstract provided.
Improving Accuracy Of Unmanned Aerial System Thermal
Infrared Remote Sensing For Use In Energy Balance Models In
Agriculture Applications,
2021
University of Nebraska - Lincoln
Improving Accuracy Of Unmanned Aerial System Thermal Infrared Remote Sensing For Use In Energy Balance Models In Agriculture Applications, Mitchell S. Maguire, C.M.U. Neale, Wayne E. Woldt
Department of Mechanical and Materials Engineering: Faculty Publications
Unmanned aerial system (UAS) remote sensing has rapidly expanded in recent years, leading to the development of several multispectral and thermal infrared sensors suitable for UAS integration. Remotely sensed thermal infrared imagery has been used to detect crop water stress and manage irrigation by leveraging the increased thermal signatures of water stressed plants. Thermal infrared cameras suitable for UAS remote sensing are often uncooled microbolometers. This type of thermal camera is subject to inaccuracies not typically present in cooled thermal cameras. In addition, atmospheric interference also may present inaccuracies in measuring surface temperature. In this study, a UAS with integrated …
Anisotropic Scaffolds For Peripheral Nerve And Spinal Cord Regeneration,
2021
University of Nebraska Medical Center
Anisotropic Scaffolds For Peripheral Nerve And Spinal Cord Regeneration, Wen Xue, Wen Shi, Yunfan Kong, Mitchell Kuss, Bin Duan
Department of Mechanical and Materials Engineering: Faculty Publications
The treatment of long-gap (>10 mm) peripheral nerve injury (PNI) and spinal cord injury (SCI) remains a continuous challenge due to limited native tissue regeneration capabilities. The current clinical strategy of using autografts for PNI suffers from a source shortage, while the pharmacological treatment for SCI presents dissatisfactory results. Tissue engineering, as an alternative, is a promising approach for regenerating peripheral nerves and spinal cords. Through providing a beneficial environment, a scaffold is the primary element in tissue engineering. In particular, scaffolds with anisotropic structures resembling the native extracellular matrix (ECM) can effectively guide neural outgrowth and reconnection. In …
Six-Sigma Quality Management Of Additive Manufacturing,
2021
The Pennsylvania State University
Six-Sigma Quality Management Of Additive Manufacturing, Hui Yang, Prahalad Rao, Timothy Simpson, Yan Lu, Paul Witherell, Abdalla R. Nassar, Edward Reutzel, Soundar Kumara
Department of Mechanical and Materials Engineering: Faculty Publications
Quality is a key determinant in deploying new processes, products, or services and influences the adoption of emerging manufacturing technologies. The advent of additive manufacturing (AM) as a manufacturing process has the potential to revolutionize a host of enterprise-related functions from production to the supply chain. The unprecedented level of design flexibility and expanded functionality offered by AM, coupled with greatly reduced lead times, can potentially pave the way for mass customization. However, widespread application of AM is currently hampered by technical challenges in process repeatability and quality management. The breakthrough effect of six sigma (6S) has been demonstrated in …
Dynamics Of Running Processes In The Area Of Underless Water Intake,
2021
TIIAME
Dynamics Of Running Processes In The Area Of Underless Water Intake, D.R. Bazarov, M.P. Tashkhanova, A. Gayur, M. Sapaeva
Irrigation and Melioration
The paper analyzes the dynamics of channel processes based on the results of field studies of the Amudarya River at the site of the damless water intake to the Karshi Magistralny Canal (KMK) and developed recommendations for improving the water intake conditions. Based on the results of field studies of the head section of the inlet channel, an assessment of the state of the Amudarya river bed in the water intake zone was made. The results of studies of the hydraulic and alluvial regimes of the Amu Darya River in the area of the damless water intake are generalized The …
Determination Of The Optimal Hydromodule Of Irrigation Network For Drip Irrigation,
2021
Research Institute of Irrigation and Water Problems
Determination Of The Optimal Hydromodule Of Irrigation Network For Drip Irrigation, R.Zh. Karshiev, A. Urazkeldiev, A.H. Radjabov, A.I. Ernazarov
Irrigation and Melioration
Most of the irrigation canals operating in the country were built in the 60s and 80s of the XX century, their hydraulic parameters were designed and adapted to the irrigation regimes of agricultural crops, mainly for surface irrigation, and the average hydromodule values were 0,8-1,0 l / s. , the hydraulic parameters of the channel are designed to carry large volumes of water in a short period of time. Over the next 3-4 years, the introduction of water-saving technologies in the irrigation of agricultural crops by farms and "Clusters" requires the improvement of hydraulic methods of irrigation management, the use …
Assessment Of The Impact Of Climate Change On Hydrological Processes In The Chirchik River Basin,
2021
TIIAME
Assessment Of The Impact Of Climate Change On Hydrological Processes In The Chirchik River Basin, Kh.Sh. Gafforov, Sh.D. Sh.D.Tursunboev
Irrigation and Melioration
The importance of assessing past and future climate differences plays an important role in future planning in relation to climate change. This situation requires urgent and concerted action in several areas: technology, infrastructure, politics, economics, and the environment. The article evaluates the impact of changes in precipitation intensity on the water level in the global circulation model (GCM) RCP 4.5 and 8.5 scenarios in the 2030s, 2050s, and 2070s. This study is a useful reference for improving water resource management and ensuring the sustainability of agricultural products in the future, as well as for improving operational water management and agricultural …
Assessment Of The Impact Of Climate Change On Hydrological Processes In The Chirchik River Basin,
2021
TIIAME
Assessment Of The Impact Of Climate Change On Hydrological Processes In The Chirchik River Basin, В.K. Saliev
Irrigation and Melioration
The article examines the assessment of the state and problems of irrigation water use in the republic in the past and in the near future. A comparative analysis of the state of water resources use for the period of the last 30 years from 1989 to 2019 was carried out.According to the estimates, own water withdrawal for 5 years (2014/15-2018/19) shows that an average of 53.2 m3, including 50.5 billion m3 from rivers At present (2018-2019), an average of 57.06 billion m3 of water is taken for irrigation of 4.289 million hectares of land, against 63.02 billion m3 approved in …
Environmental Damage Caused By Transport Equipment Waste,
2021
TIIAME
Environmental Damage Caused By Transport Equipment Waste, M. Radkevich, K. Shipilova, M. Abdukodirova, O. Pochugevski
Irrigation and Melioration
The article suggests a new approach to the monetary assessment of the damage caused to the environment by the processed waste of the transport sector. The proposed assessment method is based on the waste collection factor, all types of irretrievable losses and the volume of necessary compensatory release of materials. Based on a survey among vehicle owners, it was found that the solid waste collection rate is about 50 %, while the waste collection rate for operating fluids does not exceed 32 %. In this regard, the bulk of the damage to the environment is caused by liquid waste. Calculations …
Research Of Stress-Deformed State Of Multi-Connected Complex Shell Structures,
2021
TIIAME
Research Of Stress-Deformed State Of Multi-Connected Complex Shell Structures, Т.М. Маvlanov, Sh.O. Khudainazarov, B. Yalgashev, O.S. Nurova
Irrigation and Melioration
Conducting numerical experiments for complex structurally inhomogeneous structures allows us to understand the qualitative picture of the effect of various parameters in a wide range of studies and to give sound recommendations at the design stage for conducting laboratory model and field experiments. In this paper, on the basis of the classical theory of elasticity, the basic equations characterizing the stress-strain state of complex multiply connected shell structures are given and a specific problem is solved. At the same time, some of the structural elements have viscoelastic properties. When solving the problem, the behavior of the structure for the n-th …
To The Determination Of The Critical Circuit Speed Of The Sharing Drum,
2021
Jizzakh Polytechnic Institute
To The Determination Of The Critical Circuit Speed Of The Sharing Drum, Kh. Kh. Igamberdiev, A.B. Mukhitdinov
Irrigation and Melioration
The article is devoted to the theoretical definition of the critical circumferential speed of the stripping drum of a kena harvester, which depends on the drum diameter, diameter and weight of the stems. It was determined from the equality of the change in the momentum of the stem during impact, i.e. from a shock impulse acting on the stem. The shock impulse is determined when the drum blade touches the stem in the process of stripping, which acts on the mass of the entire stem. The duration of the impact of the drum stripping on the stem was determined from …
An Innovative Seeder For Sowing Non-Loose Seeds Of Saxaul And Cherkez,
2021
TIIAME
An Innovative Seeder For Sowing Non-Loose Seeds Of Saxaul And Cherkez, E.T. Farmonov
Irrigation and Melioration
The main reasons for the absence of a seeder for mechanized sowing of non-loose seeds of fodder plants in deserts are analyzed in the article. The author has developed a technology for sowing non-loose seeds (saxaul and cherkez), which prevents clogging, crushing and breakage in the seeder hopper, and provides for uniform and stable sowing at a set rate and shallow depth over the entire field area without reducing the biological germination. An innovative seeder with a universal sowing unit is recommended. Field tests of the innovative seeder with the proposed universal sowing unit were conducted in February 2020, as …
