Current Issue (Volume - 3 | Issue - 6) at IgMin Research

In this paper we present a physics-based model for hot carrier surface mobility in semiconductor devices and sensors which incorporates the band structure and interface/surface effects. This model can be utilized within the generalized hydrodynamic model (HDM), for semiconductor device and sensor simulation [1]. The proposed non-local surface mobility model is essentially needed in the hydrodynamic transport modelling of hot carriers as an energy-dependent model. Unfortunately, most of the involved parameters in the hydrodynamic simulation of s...emiconductor devices and sensors are obtained from Monte Carlo simulation in the bulk of a homogenous semiconductor. However, the correct simulation of the dynamic behaviors of hot carrier transport across semiconductor surfaces and junctions, needs to consider the main variable gradients, such as the carrier density, energy (or temperature) and velocity gradients. In particular, the velocity gradient plays a significant role in the transport of hot carriers in 2D electron/hole gas devices. Therefore, our mobility model focuses on the role of velocity gradients of hot carriers and the underlying carrier gas viscosity, to interpret the well-known surface mobility reduction, near the Si/SiO2 interface in nano devices and nano sensors. Unlike previous surface mobility models, which are primarily based on the local electric field and fitting of experimental data, our model is physics-based on the hot carrier energy and velocity gradients. Therefore, our model is also considered truly non-local and fully hydrodynamic.Read more

Copper is one of the most demanded minerals by the global industrial sector, with approximately 20 million tons mined worldwide each year. Silver, another important technical and precious metal, sees production around 26 kt/y. The general trend of declining average grades in these deposits has made mining low-grade ores a reality for many mines worldwide. Sensor-based sorting has emerged as a significant pre-concentration solution for these cases. This study investigates the applicability of this technique to copper ore samples from the Cerro d...o Andrade deposit, located in Caçapava do Sul, southern Brazil. The primary product of interest is copper (Cu), with silver (Ag) as a by-product. Pre-concentration tests are ongoing at the UFRGS Mineral Processing Laboratory (LAPROM) using a dual-energy X-ray transmission (DE-XRT) sensor sorter. Thirty-two ore samples were analyzed (64-16 mm size fraction). Relative density histograms and false-color images were generated. This data, along with Cu and Ag grades, was assessed in Excel to estimate recoveries (metallurgical and mass), concentration factors, and Cu and Ag grades in tailings fractions. Some scenarios of tailings generation and reuse were also explored. The analyzed samples had an average of 0.83% Cu and 7.31 g/t Ag. Pre-concentration simulations produced Cu grades in the product ranging from 0.9% to 1.0% and Ag grades of 7.8 to 8.8 g/t in the Range A. Waste grades ranged from 0.02% to 0.20% Cu and 0.7 - 2.2 g/t Ag. Range B exhibited more stable Cu and Ag grades in the product (around 0.9% Cu and 11 g/t Ag). Mass recoveries ranged from 92% - 77% in the Range A and reached 70% in the Range B. Metallurgical recoveries remained high: 99% - 95% Cu in the Range A and above 94% in the Range B. Silver recoveries were also promising (99% - 93% in Range A, 90% in Range B). Considering a feed of 1,000 kt/y, estimated ROM mass after pre-concentration ranged from 833-675 kt/y of product and 167 - 325 kt/y of coarse tailings. Reuse possibilities as remineralizers and civil aggregates hold promise. These preliminary findings indicate strong potential, demonstrating the potential for achieving significant outcomes through the implementation of sensor-based sorting pre-concentration in the Andrade Project.Read more

Physical literacy is a multidimensional construct encompassing physical competence, motivation, confidence, knowledge, and understanding, enabling individuals to engage in lifelong physical activity. This study aimed to adapt the Physical Literacy Scale for Adults (PLAS), originally developed by Naylor, et al. (2024), into Turkish and to evaluate its psychometric properties. The study used a convenience sampling method to include 454 adult participants (40.1% female, 59.9% male; mean age = 30.38 years). The translation process employed the tran...slation–back translation technique, ensuring semantic and conceptual equivalence. Construct validity was examined through exploratory factor analysis (EFA) and confirmatory factor analysis (CFA), while internal consistency was assessed using Cronbach's alpha. The EFA revealed a five-factor structure—Motivation, Social, Confidence, Physical (Coordination and Strength), and Knowledge—explaining 64.64% of the total variance. The CFA results indicated acceptable model fit (χ²/df = 2.062, RMSEA = .06, CFI = .90, GFI = .85, SRMR = .07). Cronbach's alpha coefficients ranged from .76 to .87 across subscales, with an overall reliability of .88. These findings suggest that the Turkish version of PLAS is a valid and reliable instrument for assessing physical literacy in adult populations.Read more