Navajo Technical University (NTU) is a public tribal land-grant university in Crownpoint, New Mexico, with sites in the towns of Chinle, Arizona and Teec Nos Pos, Arizona. NTU is the largest tribal college in the country and is a 1994 land grant university. It has been accredited by the Higher Learning Commission since 2005 and is home to the first accredited veterinary technician program on an Indian reservation..
The global persistence of per- and polyfluoroalkyl substances (PFAS), often referred to as “forever chemicals,” poses significant environmental and human health risks, driving regulatory action and intensified research into effective remediation strategies. Photocatalysis has emerged as a promising, sustainable approach for PFAS degradation via light-driven redox processes. Titanium dioxide (TiO2) remains the benchmark photocatalyst due to its chemical stability, low toxicity, and strong oxidative potential; however, its practical application is limited by rapid electron–hole recombination, restricted visible-light absorption, and pH-dependent surface charge behavior, necessitating acidic conditions for optimal performance. These constraints reduce its efficacy against the robust carbon–fluorine bonds characteristic of PFAS and complicate large-scale deployment. Recent advances focus on multifunctional TiO2-based systems, including metal and nonmetal doped systems, carbonaceous composites, heterojunctions, molecularly imprinted polymers, and adsorptive concentrate-and-destroy supports. Integration with advanced oxidation and reactor-level engineering approaches, such as photoelectrocatalysis (i.e., photocatalysis under applied bias) and hybrid oxidants, has further advanced photocatalytic degradation technology under broader operating conditions. This review provides a critical comparative assessment of these strategies, highlighting mechanistic insights, structure–activity relationships, and practical limitations related to pH, stability, and scalability. By consolidating recent innovations and operational considerations, this work offers guidance for the rational design of efficient, field-relevant, and sustainable photocatalytic technologies for global PFAS remediation.
The catalytic performance of metal-organic frameworks (MOFs) depends on their geometry, porosity, and surface functionality. In this study, we synthesized a Zn-BDC MOF having unique topology via the solvothermal method. Single-crystal X-ray diffraction revealed a monoclinic crystal system (Z = 2), with Zn(II) centers in distorted trigonal bipyramidal geometry coordinated to four O atoms from BDC and one O from a DMF guest molecule. Unlike typical MOFs, the BDC ligands here coordinate exclusively in a monodentate fashion, forming a rigid sinusoidal laddertype 3D framework with host-guest cavities. Non-covalent Zn center dot center dot center dot Zn interactions (2.942 & Aring;), hydrogen bonding (3.303 & Aring;), and DMF coordination (O center dot center dot center dot O = 2.590 & Aring;) contribute to the structural integrity. Thermal stability up to 450 degrees C and a surface area of 108.14 m2/g (BET) were observed. Catalytic studies demonstrated the Zn-BDC MOF's efficiency and green catalytic behavior in the N-alkylation of aromatic amines using environmentally benign diethyl carbonate (DEC) under solvent-free conditions. Optimal conditions (10 mol% catalyst, 180 degrees C, 4 h) gave 90% yield for N-ethylation of p-anisidine. Systematic variation confirmed strong dependence on catalyst loading, temperature, and reactant molar ratios. The substrate scope included substituted aromatic amines, delivering yields of 81-91%. These results highlight the Zn-BDC MOF as a thermally stable, recyclable, and efficient heterogeneous catalyst, and thus demonstrating the design of organic polymeric frameworks to play a key role in its catalytic potential.
Microchannels (MICHs) play a critical role in microfluidic, thermal management, and MEMS-based applications, where dimensional precision and surface integrity are essential. Although laser micromachining offers a rapid and flexible fabrication approach, systematic multi-parameter optimization for plexiglas-based microchannels remains limited. In this study, a statistically validated optimization framework was developed for CO₂ laser micromachining of plexiglas substrates. Five key process parameters—laser power, traverse velocity, pulse frequency, spot size, and number of passes—were investigated using Response Surface Methodology (RSM) combined with Central Composite Design (CCD). Scanning Electron Microscopy (SEM) was employed to evaluate channel geometry, surface morphology, and heat-affected zone characteristics. The results indicate that increased laser power significantly enhances channel depth, while higher traverse velocity reduces thermal penetration. Interaction analysis revealed dominant influence of power and traversing on both depth and width responses. The developed regression models demonstrated strong statistical adequacy (R² > 0.97) with prediction errors below 6
Crop classification supports food security by improving resource management and sustainable agricultural planning, particularly in arid regions such as the Navajo Nation, where water scarcity and environmental variability make agriculture essential to the community. This study evaluates a year-wise crop-classification workflow for the Navajo Nation by integrating high-confidence CDL-derived reference samples with multi-temporal Sentinel-2 vegetation indices in Google Earth Engine using a Random Forest classifier. The proposed approach achieved an overall classification accuracy of 86.70% for 2017 and 83.71% for 2022, demonstrating improved performance compared to the original CDL products.
This study presents the design and evaluation of a stand-alone photovoltaic (PV) energy system intended to support the daily electrical needs of an off-grid Navajo Nation household with an estimated energy consumption of 16 kWh per day (objective). Many Navajo homes are located in remote, rural areas where grid access is limited or unavailable(problem statement), (result) making self-sufficient solar power systems essential for ensuring reliable and sustainable electricity. The system configuration developed in this study includes a 4 kW PV array, a 42–45 kWh LiFePO4 battery bank, a 60–80 A MPPT charge controller, and a 4–5 kW pure sine wave inverter, each selected to match local solar conditions, load characteristics, and national electrical standards. The design process accounts for the region’s with high solar irradiance, seasonal weather patterns, daily load profiles, and the need for at least two days of energy autonomy during cloudy or winter periods. Engineering calculations were used to size each component, ensuring efficient energy production, safe storage, and stable AC power delivery to residential appliances. The results demonstrate that the proposed stand-alone PV system can provide dependable, round-the-clock electricity while reducing dependence on fossil-fuel generators and improving overall living conditions for households in the Navajo Nation. By leveraging renewable energy resources and applying best-practice system design principles, this study offers a practical and sustainable pathway to address long-standing energy access challenges in off-grid Indigenous communities.
