Mass Analysis of Ballistic Electron Spectra

The metal/semiconductor interface is of vital importance to a number of electronic devices. The energy barrier that forms at this interface can dominate the overall electronic properties of a device. A poor interface can prevent a device from reaching its full potential. Thus, a better understanding of the mechanisms that determine this barrier could aid in the optimization of an interface for a particular application. For the current project, electrons were shot into gold films deposited on a molybdenum disulfide (2) semiconductor at different voltages using a scanning tunneling microscope in a ballistic electron configuration. The number of electrons entering the 2 as a function of voltages can be used to determine the energy barrier, or threshold voltage, at this interface by fitting individual spectrum to the theory. For this project, spectra were taken in a grid fashion (10x10) to examine the energy barrier at different locations on the sample to investigate how impurities affect the quality of the interface. To do so each spectrum had to be fitted individually, a time consuming task. To make this process more efficient, a program was written in MATLAB to automate this process. The program was used to prepare the raw data to fit to theory. The fitted data was used to create an energy barrier map of the interface, displaying areas where it is easy or hard for electrons to traverse the interface. This current map lacks the resolution to identify impurities. However, in the future a 500x500 matrix should be sufficient

Out-of-plane electron transport in finite layer MoS2

Ballistic electron emission microscopy (BEEM) has been used to study the processes affecting electron transport along the [0001] direction of finite layer MoS2 flakes deposited onto the surface of Au/Si(001) Schottky diodes. Prominent features present in the differential spectra from the MoS2 flakes are consistent with the density of states of finite layer MoS2 calculated using density functional theory. The ability to observe the electronic structure of the MoS2 appears to be due to the relatively smooth density of states of Si in this energy range and a substantial amount of elastic or quasi-elastic scattering along the MoS2/Au/Si(001) path. Demonstration of these measurements using BEEM suggests that this technique could potentially be used to study electron transport through van der Waals heterostructures, with applications in a number of electronic devices

A Decision-Analytic Model to Assess the Cost-Effectiveness of Etelcalcetide vs. Cinacalcet.

INTRODUCTION: Etelcalcetide is a novel intravenous calcimimetic for the treatment of secondary hyperparathyroidism (SHPT) in haemodialysis patients. The clinical efficacy and safety of etelcalcetide (in addition to phosphate binders and vitamin D and/or analogues [PB/VD]) was evaluated in three phase III studies, including two placebo-controlled trials and a head-to-head study versus the oral calcimimetic cinacalcet. OBJECTIVE: The objective of this study was to develop a decision-analytic model for economic evaluation of etelcalcetide compared with cinacalcet. METHODS: We developed a life-time Markov model including potential treatment effects on mortality, cardiovascular events, fractures, and subjects' persistence. Long-term efficacy of etelcalcetide was extrapolated from the reduction in parathyroid hormone (PTH) in the phase III trials and the available data from the outcomes study in cinacalcet (EVOLVE trial). Etelcalcetide was compared with cinacalcet, both in addition to PB/VD. We applied unit costs averaged from five European countries and a range of potential etelcalcetide pricing options assuming parity price to weekly use of cinacalcet and varying it by a 15 or 30% increase. RESULTS: Compared with cinacalcet, the incremental cost-effectiveness ratio of etelcalcetide was €1,355 per QALY, €24,521 per QALY, and €47,687 per QALY for the three prices explored. The results were robust across the probabilistic and deterministic sensitivity analyses. CONCLUSIONS: Our modelling approach enabled cost-utility assessment of the novel therapy for SHPT based on the observed and extrapolated data. This model can be used for local adaptations in the context of reimbursement assessment

Large-field magnetoresistance of nanometer scale nickel films grown on molybdenum disulfide

The magnetoresistance of thin nickel films grown on molybdenum disulfide was measured in perpendicular magnetic fields as high as 90 kOe. Films with thicknesses of 20 nm provided continuous surfaces for measurement. The magnetoresistance was found to be linear with respect to the applied magnetic field with no sign of saturation. There was also no evidence of hysteresis or temperature dependence between 100 to 300 K. STM measurement showed the deposited Ni forms a continuous film of extremely small nanoclusters. However, the field dependence of magnetoresistance was found to be significantly larger than bulk Ni, which is in turn larger than Ni with nanoscale grains. We expect the unusual magnetoresistance behavior to arise from some property of the Ni-MoS2 interface

How can students-as-partners work address challenges to student, faculty, and staff mental health and well-being?

Mental health has emerged as a critical area of attention in higher education, and educational research over the last 15 years has focused increasingly on emotions and wellbeing at all stages of education (Hill et al., 2021). While definitions of well-being vary, most are premised on “good quality of life” (Nair et al., 2018, p. 69). Within the last few years, we have experienced an intersection of several forces that undermine or threaten good quality of life. These include the uncertainties prompted by the COVID-19 pandemic (Hews et al., 2022, U.S. Surgeon General, n.d.), climate change (Charlson et al., 2021), racism and social injustices (Williams & Etkins, 2021), the cost-of-living crisis (Montacute, 2023), and the lack of motivation and higher incidence of mental health issues associated with growing concerns about job prospects and income (Chowdhury et al., 2022). This fifth iteration of Voices from the Field explores some of the ways in which students-as-partners work can address challenges to the mental health and well-being of students, faculty, and staff. This focus, proposed by members of the IJSaP Editorial Board, both responds to the intersecting realities named above and remains true to the goal of this section of the journal, which is to offer a venue for a wide range of contributors to address important questions around and aspects of students-as-partners work without going through the intensive submission, peer-review, and revision processes. The prompt we included in the call for this iteration of Voices was: “In what ways can students-as-partners work address challenges to the mental health and well-being of students, staff, and faculty posed by the current realities in the wider world (socio-political, environmental, economic, etc.) that affect higher education?

Ultra-flat Au Surfaces on Finite Layer MoS2

We have developed a method for creating ultra-flat Au surfaces by sputtering Au onto thin films of MoS2. This method is more cost effective than current technologies. Our Au surfaces are subatomically flat over relatively large areas making them useful for self assembled monolayer (SAM) research

Electrical Transport Measurements on Ni Films Deposited on MoS₂

MoS2 is a semiconductor with attractive characteristics that make it a possible replacement material for silicon in electronics devices. It is therefore important to study the behavior of metals that are in contact with MoS2. We have investigated the electrical resistance of a thin film of nickel grown on MoS2 as a function of temperature with and without a magnetic field applied. The Ni-MoS2 structure exhibits semiconducting behavior. We present evidence that electron transport proceeds via hopping