Improved determination of particulate absorption from combined filter pad and PSICAM measurements

Filter pad light absorption measurements are subject to two major sources of experimental uncertainty: the so-called pathlength amplification factor, β, and scattering offsets, o, for which previous null-correction approaches are limited by recent observations of non-zero absorption in the near infrared (NIR). A new filter pad absorption correction method is presented here which uses linear regression against point-source integrating cavity absorption meter (PSICAM) absorption data to simultaneously resolve both β and the scattering offset. The PSICAM has previously been shown to provide accurate absorption data, even in highly scattering waters. Comparisons of PSICAM and filter pad particulate absorption data reveal linear relationships that vary on a sample by sample basis. This regression approach provides significantly improved agreement with PSICAM data (3.2% RMS%E) than previously published filter pad absorption corrections. Results show that direct transmittance (T-method) filter pad absorption measurements perform effectively at the same level as more complex geometrical configurations based on integrating cavity measurements (IS-method and QFT-ICAM) because the linear regression correction compensates for the sensitivity to scattering errors in the T-method. This approach produces accurate filter pad particulate absorption data for wavelengths in the blue/UV and in the NIR where sensitivity issues with PSICAM measurements limit performance. The combination of the filter pad absorption and PSICAM is therefore recommended for generating full spectral, best quality particulate absorption data as it enables correction of multiple errors sources across both measurements

Opportunities and Challenges in Professional Education-related Faculty Development in the US

The authors outline important opportunitiesand challenges relating to formal education-relatedfaculty development on a large scale. Questions exploredare: What major opportunities exist regarding movingtowards educational professional qualification for USHigher Education institutions, their faculty and students,industry, and society as a whole? How can resources besynergistically integrated to support such an effort?What are the major challenges or barriers present thatmust be overcome in order to create such a system? Inresponse to these questions, a concept map is presentedto explore how faculty educational development couldsupport and greatly enhance an entire system revolvingaround faculty development in teaching and learning.Utilizing and reflecting upon the literature, major issuesconsidered that relate to the questions above includevarious roles in the higher education engineeringcommunity; relationships between educational research,student learning outcomes, and engineering faculty;resources supporting engineering education, and theimplication of different faculty reward structures.Analysis indicates that pieces already in place offer greatpotential to create the Engineering Education of 2020 for“The Engineer of 2020” if key barriers are addressed

A Review of Professional Qualifications, Development, and Recognition of Faculty Teaching in Higher Education around the World

Recent discussion within the engineering education community has included how to documentprogressive skills in scholarly teaching and whether a philosophy of engineering education canimprove the practice of engineering education. As these types of discussions move forward, itwill be helpful to provide some context as to how these ideas might formally manifestthemselves. This paper provides a global overview of models for faculty development andrecognition in teaching in higher education.Few would disagree with the idea that educating the next generation of leaders in both academiaand industry is at the heart of what higher education is all about. However, in the US, whilemany faculty are dedicated to becoming outstanding educators, the general assumption is thatholding a PhD in a core technical area is sufficient to be qualified as an academic educator. Thisno longer holds true (and maybe never did). In order to address this issue, a number of modelshave been proposed and/or implemented in other parts of the world (Europe, Australia, Asia).These models seek to provide both professional qualification and recognition for educatorsworking in higher education. Accordingly, the research question addressed in this paper is: whatmodels for professional development and recognition in higher education have been explored orimplemented around the world? The approaches used to address this question are: conversationswith leaders in engineering education, participation in conference discussions on this topic, and aliterature survey.As a result of these efforts, this paper first reports an overview of existing model types. Majordifferences in the types of models are explained in terms of duration, incorporation withpromotion and tenure, and what components of educational practice are included in the model.Next, the various characteristics of individual models are documented in terms of content andpracticum components, contexts for implementation, and how the models work within theirvarious contexts. Finally, due to the inherently political and emotional nature of considering theuse of these models with the US, a brief reflection on experiences and lessons learned from thesemodels is presented as relevant to US higher education

Drug design on quantum computers

Quantum computers promise to impact industrial applications, for which quantum chemical calculations are required, by virtue of their high accuracy. This perspective explores the challenges and opportunities of applying quantum computers to drug design, discusses where they could transform industrial research and elaborates on what is needed to reach this goal

Uncertainty budgets for liquid waveguide CDOM absorption measurements

Long path length liquid waveguide capillary cell (LWCC) systems using simple spectrometers to determine the spectral absorption by colored dissolved organic matter (CDOM) have previously been shown to have better measurement sensitivity compared to high-end spectrophotometers using 10 cm cuvettes. Information on the magnitude of measurement uncertainties for LWCC systems, however, has remained scarce. Cross-comparison of three different LWCC systems with three different path lengths (50, 100, and 250 cm) and two different cladding materials enabled quantification of measurement precision and accuracy, revealing strong wavelength dependency in both parameters. Stable pumping of the sample through the capillary cell was found to improve measurement precision over measurements made with the sample kept stationary. Results from the 50 and 100 cm LWCC systems, with higher refractive index cladding, showed systematic artifacts including small but unphysical negative offsets and high-frequency spectral perturbations due to limited performance of the salinity correction. In comparison, the newer 250 cm LWCC with lower refractive index cladding returned small positive offsets that may be physically correct. After null correction of measurements at 700 nm, overall agreement of CDOM absorption data at 440 nm was found to be within 5% root mean square percentage error

The Application of 199 Hg NMR and 199m Hg Perturbed Angular Correlation (PAC) Spectroscopy to Define the Biological Chemistry of Hg II : A Case Study with Designed Two- and Three-Stranded Coiled Coils

The use of de novo designed peptides is a powerful strategy to elucidate Hg II –protein interactions and to gain insight into the chemistry of Hg II in biological systems. Cysteine derivatives of the designed Α-helical peptides of the TRI family [Ac-G-(L a K b A c L d E e E f K g ) 4 -G-NH 2 ] bind Hg II at high pH values and at peptide/Hg II ratios of 3:1 with an unusual trigonal thiolate coordination mode. The resulting Hg II complexes are good water-soluble models for Hg II binding to the protein MerR. We have carried out a parallel study using 199 Hg NMR and 199m Hg perturbed angular correlation (PAC) spectroscopy to characterize the distinct species that are generated under different pH conditions and peptide TRI 14L9C/Hg II ratios. These studies prove for the first time the formation of [Hg{(TRI 14L9C) 2 -(TRI 14L9C[bond]H)}], a dithiolate–Hg II complex in the hydrophobic interior of the three-stranded coiled coil (TRI 14L9C) 3 . 199 Hg NMR and 199m Hg PAC data demonstrate that this dithiolate–Hg II complex is different from the dithiolate [Hg(TRI 14L9C) 2 ], and that the presence of third Α-helix, containing a protonated cysteine, breaks the symmetry of the coordination environment present in the complex [Hg(TRI 14L9C) 2 ]. As the pH is raised, the deprotonation of this third cysteine generates the trigonal thiolate–Hg II complex Hg(TRI 14L9C) 3 − on a timescale that is slower than the NMR timescale (0.01–10 14ms). The formation of the species [Hg{(TRI 14L9C) 2 (TRI 14L9C[bond]H)}] is the result of a compromise between the high affinity of Hg II to form dithiolate complexes and the preference of the peptide to form a three-stranded coiled coil.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/57382/1/9178_ftp.pd

A Proposed Teaching and Learning Curriculum for SPEED Based on Current National Trends

We propose an introductory level teaching and learning curriculum for the ASEE COMPLEETE program (COMPetencies in Learning for Engineering and Engineering Technology Educators). COMPLEETE is an initiative for a national program to build and recognize educator excellence in engineering and engineering technology at three levels. The proposed curriculum for the introductory level is compared with curricula from nine well-established existing programs. The content is specifically targeted to benefit engineering and engineering technology instructors in higher education, integrate with the values and programs already offered within ASEE, serve as a foundation for further development at higher levels, and be flexible to suit the needs of a diverse instructional community. The nine existing programs were coded under the overarching COMPLEETE criteria and then analyzed for commonalities and alignment. The proposed core competency areas were found to comprehensively represent existing programs. They are: learning theory, student development, instructional design, instructional facilitation methods, assessing and providing feedback to learners, instructional technology, and reflective practice. The proposed curriculum lays a foundation for those offering faculty development services to compare against, and challenges the engineering and engineering technology community of educators to address key competency areas all faculty should develop within 3-5 years of beginning teaching

Light-Induced Charge Separation in Photosystem I from Different Biological Species Characterized by Multifrequency Electron Paramagnetic Resonance Spectroscopy

Photosystem I (PSI) serves as a model system for studying fundamental processes such as electron transfer (ET) and energy conversion, which are not only central to photosynthesis but also have broader implications for bioenergy production and biomimetic device design. In this study, we employed electron paramagnetic resonance (EPR) spectroscopy to investigate key light-induced charge separation steps in PSI isolated from several green algal and cyanobacterial species. Following photoexcitation, rapid sequential ET occurs through either of two quasi-symmetric branches of donor/acceptor cofactors embedded within the protein core, termed the A and B branches. Using high-frequency (130 GHz) time-resolved EPR (TR-EPR) and deuteration techniques to enhance spectral resolution, we observed that at low temperatures prokaryotic PSI exhibits reversible ET in the A branch and irreversible ET in the B branch, while PSI from eukaryotic counterparts displays either reversible ET in both branches or exclusively in the B branch. Furthermore, we observed a notable correlation between low-temperature charge separation to the terminal [4Fe-4S] clusters of PSI, termed FA and FB, as reflected in the measured FA/FB ratio. These findings enhance our understanding of the mechanistic diversity of PSI's ET across different species and underscore the importance of experimental design in resolving these differences. Though further research is necessary to elucidate the underlying mechanisms and the evolutionary significance of these variations in PSI charge separation, this study sets the stage for future investigations into the complex interplay between protein structure, ET pathways, and the environmental adaptations of photosynthetic organisms

Probing a Homoleptic PbS 3 Coordination Environment in a Designed Peptide Using 207 Pb NMR Spectroscopy: Implications for Understanding the Molecular Basis of Lead Toxicity

No AbstractPeer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/78235/1/8353_ftp.pd

Measurement uncertainties in PSICAM and reflective tube absorption meters

The nature and magnitude of measurement uncertainties (precision and accuracy) associated with two approaches for measuring absorption by turbid waters are investigated here: (a) point source integrating cavity absorption meters (PSICAM), and (b) reflective tube absorption meters (AC-9 and AC-s – both WET Labs Inc., USA). Absolute measurement precision at 440 nm was quantified using standard deviations of triplicate measurements for the PSICAM and de-trended, bin averaged time series for the AC-9/s, giving comparable levels (< 0.006 m-1) for both instruments. Using data collected from a wide range of UK coastal waters, PSICAM accuracy was assessed by comparing both total non-water absorption and absorption by coloured dissolved organic material (CDOM) measured on discrete samples by two independent PSICAMs. AC-9/s performance was tested by comparing total non-water absorption measured in situ by an AC-9 and an AC-s mounted on the same frame. Results showed that the PSICAM outperforms AC-9/s instruments with regards to accuracy, with average spread in the PSICAM total absorption data of 0.006 m-1 (RMSE) compared to 0.028 m-1 for the AC-9/s devices. Despite application of a state of the art scattering correction method, the AC-9/s instruments still tend to overestimate absorption compared to PSICAM data by on average 0.014 m-1 RMSE (AC-s) and 0.043 m-1 RMSE (AC-9). This remaining discrepancy can be largely attributed to residual limitations in the correction of AC-9/s data for scattering effects and limitations in the quality of AC-9/s calibration measurements