Key Modes Research Articles

Teaching Social Work Practice Skills: A Collaborative Autoethnography Identifying Key Practice Skills and Modes of Delivery in the Art of Social Work Practice

Abstract Social work students must advance their social work skills gaining practice competencies. And, whilst practice learning takes place in field education placements, social work students often also enrol in a dedicated unit/ course whereby the teaching of practice skills is facilitated in class. A practice skills class is another learning space to imbue practice wisdom. Adjunct teaching staff are often employed on short-term university contracts to teach social work students in the area of practice skills. Whilst these practitioners can bring a wealth of experience and expertise to the under-graduate classroom, it cannot be assumed that adjunct teaching staff have formal training in curricula development nor pedagogical delivery. The goal of this article is to identify the critical elements of teaching practice skills and to examine the ways in which teaching content is delivered. This article presents the ‘teaching the teacher’ experience of three social work educators at an Australian university. A collaborative autoethnography identified three themes from the inductive analysis: (i) teaching best practices, (ii) teaching role and (iii) teaching practice skills. Finally, implications for social work are discussed and recommendations shared.

Key Aging Modes and Mechanisms for Extreme Fast Charging of Lithium-Ion Batteries

Enabling extreme fast charging (XFC, charging in 10 to 15 minutes) in a lithium-ion battery (LiB) could play a key role in subsiding consumer’s range anxiety and spur the widespread adoption of electric vehicles (EVs).1,2 Such a high rate of charging induces unique aging modes in LiBs, thereby requiring a comprehensive understanding to enable effective solution strategies to minimize the negative effects of life and performance. This presentation will present a comprehensive understanding of the dominating aging modes and mechanisms of XFC in low- and moderate-loading Gr/NMC LiBs.We will discuss the major limitations of XFC in LiBs by first using experimental and modeling results followed by a comprehensive electrochemical analysis of cycle life aging implications for different charging conditions (e.g., 1C to 9C rate conditions). We will then discuss the aging mechanisms using comprehensive post-testing as well as multimodal and multi-scale microscopy techniques.Solid state diffusion in the negative electrode is not a key limiting factor for the fast charge conditions evaluated. Inadequate Li+ transport through the electrolyte primarily causes performance and distinct aging phenomena in LiBs. Eliminating the Li+ transport limitation within the electrolyte can offer a distinct increase in material utilization, avoiding Li deposition. Under such circumstances, the cathode could degrade in distinct ways depending on the particular NMC (e.g., NMC532 vs. NMC811) variants.NMC811 experiences a greater subsurface crystallographic degradation and interfacial degradation and displays similar extents of sub-particle cracking as compared to NMC532 under comparable charging conditions. Surprisingly, the NMC811 maintains superior electrochemical performance despite the more aggressive degradations. We found the better cycle life performance of NMC811 to be related to its inherently better solid state diffusion, electronic conduction, and radially oriented grain architecture. References S. Ahmed et al., J. Power Sources, 367, 250–262 (2017).Y. Liu, Y. Zhu, and Y. Cui, Nat. Energy, 4, 540–550 (2019).

Variations of Summer Extreme and Total Precipitation over Southeast Asia and Associated Atmospheric and Oceanic Features

Abstract Southeast Asia lies at the heart of heavy precipitation on Earth, and a large amount of latent heat released here provides substantial energy for the global atmospheric circulation. Utilizing gauge-based daily precipitation and the self-organizing map technique, the summertime extreme and total precipitation over Southeast Asia during 1979–2019 are classified into three and five distinct patterns, respectively. The three extreme precipitation clusters are characterized by southern dry and northern wet (C1_extreme), overall wet (C2_extreme), and northern dry and southern wet (C3_extreme) structures. The frequencies of these patterns exhibit increasing trends during the analysis, although they are not statistically significant for C1_extreme. The C1_extreme pattern is accompanied by an anomalous cyclone over the South China Sea in response to negative Indian Ocean sea surface temperature anomalies (SSTAs). The C2_extreme and C3_extreme clusters are characterized by a westward extension of the western Pacific subtropical high, regulated by cool SSTAs over the tropical central-eastern Pacific that are induced by the tropical North Atlantic warming and the tropical Pacific and Atlantic SSTAs, respectively. For total precipitation, the first and second clusters show overall dry distributions, which are mainly composed of nonextreme precipitation. The spatial patterns and atmospheric and oceanic features associated with the other three clusters of total precipitation bear large resemblances to those of C1_extreme, C2_extreme, and C3_extreme, respectively, but their trends exhibit smaller similarities. Comparing the differences between extreme and total precipitation over Southeast Asia could improve our understanding of their regional variabilities and relationships, and potentially their global impacts. Significance Statement We explore the atmospheric and oceanic processes associated with extreme precipitation, and compare them with those for total precipitation over Southeast Asia. The three key modes of summertime extreme precipitation over Southeast Asia are characterized by southern drought and northern flood, overall flood, and northern drought and southern flood structures. Each pattern is closely linked to tropical sea surface temperature anomalies, but in different regions. Total precipitation can be classified into five distinct patterns. The first two modes are largely determined by nonextreme precipitation, while the other three bear large resemblances to the three extreme precipitation modes. These findings provide guidance on what is the key factor in driving each extreme precipitation mode over Southeast Asia, allowing better prediction.

Single-Crystal Diffraction, Raman Spectroscopy, and Density Functional Theory of DTO [N-(1,7-Dinitro-1,2,6,7-tetrahydro-[1,3,5]triazino[1,2-c][1,3,5]oxadiazin-8(4H)-ylidene)nitramide

A combined experimental and modeling study of energetic compound N-(1,7-dinitro-1,2,6,7-tetrahydro-[1,3,5]triazino[1,2-c][1,3,5]oxadiazin-8(4H)-ylidene)nitramide [C5H6N8O7, (DTO)] has been performed. We report its crystal structure, solid-phase heat of formation, and its vibrational and electronic structure obtained by single-crystal X-ray diffractometry, Raman spectroscopy, and density functional theory (DFT). DTO exhibits two adjoining six-membered rings, a triazine ring (C3N3) and an oxadiazine ring (C3N2O) ring containing two nitro functional groups and one nitroamino group. DTO crystallizes with four molecules in its unit cell and presents a density of 1.862 kg/m3 at 298 K, in excellent agreement with both DFT calculations performed both at the molecular level using the B3LYP with the 6-311+G** basis set and the solid-state level using the hybrid functional HSE6 optimized with norm-conserving pseudopotentials. The calculated vibrational structure allows for the symmetry assignment of key Raman modes in terms of atomic movements, and the calculated frequency values are in good agreement with experiment. The solid-phase DFT calculations reveal that the N atoms of the triazine ring contribute mostly to the density of states at the Fermi level. In addition, we present and discuss the computed solid-phase heat of formation (215.9 kJ/mol) and molecular electrostatic potential surface of DTO and compare them to complementary materials.

Anti-PANoptosis is involved in neuroprotective effects of melatonin in acute ocular hypertension model.

Acute ocular hypertension (AOH) is the most important characteristic of acute glaucoma, which can lead to retinal ganglion cell (RGC) death and permanent vision loss. So far, approved effective therapy is still lacking in acute glaucoma. PANoptosis (pyroptosis, apoptosis, and necroptosis), which consists of three key modes of programmed cell death-apoptosis, necroptosis, and pyroptosis-may contribute to AOH-induced RGC death. Previous studies have demonstrated that melatonin(N-acetyl-5-methoxytryptamine) exerts a neuroprotective effect in many retinal degenerative diseases. However, whether melatonin is anti-PANoptotic and neuroprotective in the progression of acute glaucoma remains unclear. Thus, this study aimed to explore the role of melatonin in AOH retinasand its underlying mechanisms. The results showed that melatonin treatment attenuated the loss of ganglion cell complex thickness, retinal nerve fiber layer thickness, and RGC after AOH injury, and improved the amplitudes of a-wave, b-wave, and oscillatory potentials in the electroretinogram. Additionally, the number of terminal deoxynucleotidyl transferase dUTP nick-end labeling-positive cells was decreased, and the upregulation of cleaved caspase-8, cleaved caspase-3, Bax, and Bad and downregulation of Bcl-2 and p-Bad were inhibited after melatonin administration. Meanwhile, both the expression and activation of MLKL, RIP1, and RIP3, along with the number of PI-positive cells, were reduced in melatonin-treated mice, and p-RIP3 was in both RGC and microglia/macrophage after AOH injury. Furthermore, melatonin reduced the expression of NLRP3, ASC, cleaved caspase-1, gasdermin D (GSDMD), and cleaved GSDMD, and decreased the number of Iba1/interleukin-1β-positive cells. In conclusion, melatonin ameliorated retinal structure, prevented retinal dysfunction after AOH, and exerted a neuroprotective effect via inhibition of PANoptosis in AOH retinas.

Forced Response System Identification of Full Aero-Engine Rotordynamic Systems for Prognostics and Diagnostics

Abstract A first-of-its-kind forced-response system identification approach is introduced to measure rotordynamic damping of shaft modes in a full gas turbine aero-engine. The approach involves forced-response modal analysis in which the rotordynamic system is excited with an external shaker, and engine modal characteristics are extracted from rotor shaft response signals. A reduced-order modeling framework capturing full-engine dynamics and coupling between rotor shafts and support static structure was developed and implemented in a Pratt & Whitney Canada PW615 Turbofan engine. The framework was used to guide the design of forced-response system identification experiments. The design study shows that two orthogonal shakers are required to excite both forward- and backward-whirling shaft modes and that excessive forcing amplitudes that produce whirl over 0.4 of journal eccentricity ratio can yield up to 12% lower response magnitudes due to nonlinear bearing characteristics. A statistical analysis of virtual experiments under real engine operating conditions demonstrates feasibility and robustness of the approach, measuring rotordynamic damping for key shaft modes with an uncertainty of up to 15%. General applicability of the approach with similar error levels is suggested for multispool multiframe aero-engine architectures. Guidelines for experimental setup, data acquisition, and processing are established for full-engine forced-response system identification experiments. The new capability shows promise in supporting aero-engine diagnostics and prognostics to improve the life cycle operation of commercial and military engines.

The JWST Early Release Science Program for the Direct Imaging and Spectroscopy of Exoplanetary Systems

The direct characterization of exoplanetary systems with high-contrast imaging is among the highest priorities for the broader exoplanet community. As large space missions will be necessary for detecting and characterizing exo-Earth twins, developing the techniques and technology for direct imaging of exoplanets is a driving focus for the community. For the first time, JWST will directly observe extrasolar planets at mid-infrared wavelengths beyond 5 μm, deliver detailed spectroscopy revealing much more precise chemical abundances and atmospheric conditions, and provide sensitivity to analogs of our solar system ice-giant planets at wide orbital separations, an entirely new class of exoplanet. However, in order to maximize the scientific output over the lifetime of the mission, an exquisite understanding of the instrumental performance of JWST is needed as early in the mission as possible. In this paper, we describe our 55 hr Early Release Science Program that will utilize all four JWST instruments to extend the characterization of planetary-mass companions to ∼15 μm as well as image a circumstellar disk in the mid-infrared with unprecedented sensitivity. Our program will also assess the performance of the observatory in the key modes expected to be commonly used for exoplanet direct imaging and spectroscopy, optimize data calibration and processing, and generate representative data sets that will enable a broad user base to effectively plan for general observing programs in future Cycles.

Development of an intervention to facilitate dissemination of community-based training to respond to out-of-hospital cardiac arrest: FirstCPR.

Out-of-hospital cardiac arrest (OHCA) is a significant public health issue with low survival rates. Prompt bystander action can more than double survival odds. OHCA response training is primarily pursued due to work-related mandates, with few programs targeting communities with lower training levels. The aim of this research was to describe the development process of a targeted multicomponent intervention package designed to enhance confidence and training among laypeople in responding to an OHCA. An iterative, three-phase program development process was employed using a mixed methods approach. The initial phase involved establishment of a multidisciplinary panel that informed decisions on key messages, program content, format, and delivery modes. These decisions were based on scientific evidence and guided by behavioural theories. The second phase comprised the development of the intervention package, identifying existing information and developing new material to fill identified gaps. The third phase involved refining and finalising the material via feedback from panel members, stakeholders, and community members. Through this approach, we collaboratively developed a comprehensive evidence-based education and training package consisting of a digital intervention supplemented with free access to in-person education and training. The package was designed to teach community members the specific steps in recognising and responding to a cardiac arrest, while addressing commonly known barriers and fears related to bystander response. The tailored program and delivery format addressed the needs of individuals of diverse ages, cultural backgrounds, and varied training needs and preferences. The study highlights the importance of community engagement in intervention development and demonstrates the need of evidence-based and collaborative approaches in creating a comprehensive, localised, relatively low-cost intervention package to improve bystander response to OHCA.

Novel hybrid machine learning framework with decomposition–transformation and identification of key modes for estimating reference evapotranspiration

The accurate estimation of reference evapotranspiration (ETo) is a fundamental requirement for precision irrigation and regional water resource planning. In this regard, the application of the standard model, FAO-56 Penman–Monteith, is limited because of insufficient meteorological data. This study aims to improve the accuracy of ETo calculations in regions with scarce meteorological data. A hybrid model integrating two data preprocessing methods (variational mode decomposition (VMD) and Box–Cox transformation (BC)) into a support vector machine (SVM) model (VMD–BC–SVM) is proposed. The model estimates the daily ETo based on the meteorological data (1980–2019) of 10 stations in the Wei River Basin of China. The VMD method was employed to extract multiple intrinsic mode functions (IMFs) and eliminate non-stationarity. This is achieved by decomposing meteorological factors, which are further transformed by BC to alleviate skewness characteristics. The least absolute shrinkage and selection operator regression (LASSO) identifies the key driving modes from the transformed IMFs, which are used as the input of the SVM model. The VMD–BC–SVM estimation model framework based on decomposition–transformation–identification–estimation is proposed. The performance of each of the hybrid VMD–BC–SVM models was further compared with those of the standalone extreme learning machine (ELM) model and two empirical models (Hargreaves–Samani and Priestley–Taylor models). The results revealed that the hybrid models outperformed the single models. The VMD–BC–SVM model achieved higher accuracy compared with the other models. Specifically, the coefficient of correlation (R) and Nash–Sutcliffe efficiency coefficient (NSE) were both greater than 0.96. Furthermore, the mean absolute percentage error (MAPE) and root mean square error (RMSE) were less than 8.41% and 0.38 mm/d, respectively. In terms of the amount of information provided, the VMD–BC–SVM model is superior to empirical models in identifying high-dimensional and nonlinear information. Moreover, the estimation performance is more stable, and the level of uncertainty is lower. This study provides a novel approach for predicting ETo in regions with limited meteorological data.

Insights into Cation Ordering of Double Perovskite Oxides from Machine Learning and Causal Relations

This work investigates the origins of cation ordering of double perovskites using first-principles theory computations combined with machine learning (ML) and causal relations. We have considered various oxidation states of A, A', B, and B' from the family of transition metal ions to construct a diverse compositional space. A conventional framework employing traditional ML classification algorithms such as Random Forest (RF) coupled with appropriate features including geometry-driven and key structural modes leads to highly accurate prediction (~98%) of A-site cation ordering. We have evaluated the accuracy of ML models by entailing analyses of decision paths, assignments of probabilistic confidence bound, and finally introducing a direct non-Gaussian acyclic structural equation model to investigate causality. Our study suggests that the structural modes are the most important features for classifying layered, columnar and rock-salt ordering. For clear layered ordering, the charge difference between the A and A' is the most important feature which in turn depends on the B, B' charge separation. Based on the outputs from ML models, we have designed functional forms with these features to derive energy differences forming clear layered ordering. The trilinear coupling between tilt, rotation, and A-site antiferroelectric displacement in Landau free-energy expansion becomes the necessary condition behind the formation of A-site cation ordering.

‘The body is a tool for remembrance’

This article is a preliminary analysis of the role of the body in core rituals of a North American branch of the Shadhilyya Sufi order. It draws upon fieldwork conducted between 2016 and 2020 to consider how spiritual healing practices involve the human body sensorily and in experiential, imaginative realms, as conveyed through practitioners’ verbal descriptions of what they feel in the body and how they understand their bodies and the bodies of others. I demonstrate how, in these healing practices, the body is instrumentalized in three key modes – as barometer, controller, and ground of energy – that change the way it is experienced. I argue that the ‘ordinary’ – or, non-extraordinary – body is instrumentalized through these healing modalities to become the site of transformation from spirit to material and material to spirit, and that through this the body emerges as central to everyday, lived Sufi practice. The healings discussed incorporate traditional Muslim devotional practices and long-standing Islamic and Sufi rituals such as dhikr (remembrance, recollection of the divine), recitation of the 99 names of the divine, Qur’anic recitation, cupping, and less traditionally Islamic practices such as acupuncture.

Mode-selective ballistic pathway to a metastable electronic phase.

Exploiting vibrational excitation for the dynamic control of material properties is an attractive goal with wide-ranging technological potential. Most metal-to-insulator transitions are mediated by few structural modes and are, thus, ideal candidates for selective driving toward a desired electronic phase. Such targeted navigation within a generally multi-dimensional potential energy landscape requires microscopic insight into the non-equilibrium pathway. However, the exact role of coherent inertial motion across the transition state has remained elusive. Here, we demonstrate mode-selective control over the metal-to-insulator phase transition of atomic indium wires on the Si(111) surface, monitored by ultrafast low-energy electron diffraction. We use tailored pulse sequences to individually enhance or suppress key phonon modes and thereby steer the collective atomic motion within the potential energy surface underlying the structural transformation. Ab initio molecular dynamics simulations demonstrate the ballistic character of the structural transition along the deformation vectors of the Peierls amplitude modes. Our work illustrates that coherent excitation of collective modes via exciton-phonon interactions evades entropic barriers and enables the dynamic control of materials functionality.

Exploration of Somatostatin Binding Mechanism to Somatostatin Receptor Subtype 4.

Somatostatin (also named as growth hormone-inhibiting hormone or somatotropin release-inhibiting factor) is a regulatory peptide important for the proper functioning of the endocrine system, local inflammatory reactions, mood and motor coordination, and behavioral responses to stress. Somatostatin exerts its effects via binding to G-protein-coupled somatostatin receptors of which the fourth subtype (SSTR4) is a particularly important receptor mediating analgesic, anti-inflammatory, and anti-depressant effects without endocrine actions. Thus, SSTR4 agonists are promising drug candidates. Although the knowledge of the atomic resolution-binding modes of SST would be essential for drug development, experimental elucidation of the structures of SSTR4 and its complexes is still awaiting. In the present study, structures of the somatostatin–SSTR4 complex were produced using an unbiased, blind docking approach. Beyond the static structures, the binding mechanism of SST was also elucidated in the explicit water molecular dynamics (MD) calculations, and key binding modes (external, intermediate, and internal) were distinguished. The most important residues on both receptor and SST sides were identified. An energetic comparison of SST binding to SSTR4 and 2 offered a residue-level explanation of receptor subtype selectivity. The calculated structures show good agreement with available experimental results and indicate that somatostatin binding is realized via prerequisite binding modes and an induced fit mechanism. The identified binding modes and the corresponding key residues provide useful information for future drug design targeting SSTR4.

Competitive Binding of Ozanimod and Other Sphingosine 1-Phosphate Receptor Modulators at Receptor Subtypes 1 and 5.

Ozanimod, a sphingosine 1-phosphate (S1P) receptor modulator, binds with high affinity selectively to S1P receptor subtypes 1 (S1P1) and 5 (S1P5), and is approved in multiple countries for treating adults with relapsing forms of multiple sclerosis (MS) or moderately to severely active ulcerative colitis (UC). Other S1P receptor modulators have been approved for the treatment of MS or are in clinical development for MS or UC, but it is unknown whether these compounds bind competitively with each other to S1P1 or S1P5. We developed a competitive radioligand binding assay using tritiated ozanimod and demonstrate full displacement of ozanimod by S1P (endogenous ligand), suggesting that ozanimod binds to the S1P1 and S1P5 orthosteric binding sites. S1P receptor modulators FTY720-p, siponimod, etrasimod, ponesimod, KRP-203-p, and amiselimod-p also completely displacing radiolabeled ozanimod; thus, on a macroscopic level, all bind to the same site. Molecular docking studies support these results and predict the binding of each molecule to the orthosteric site of the receptors, creating similar interactions within S1P1 and S1P5. The absolute free energy perturbation method further validated key proposed binding modes. Functional potency tightly aligned with binding affinities across S1P1 and S1P5 and all compounds elicited S1P1-mediated β-arrestin recruitment. Since all the S1P modulators included in this study display similar receptor pharmacology and compete for binding at the same site, they can be considered interchangeable with one another. The choice of any one particular agent should therefore be made on the basis of overall therapeutic profile, and patients can be offered the opportunity to switch S1P medications without the potential concern of additive S1P pharmacology.

Recent advances in laser welding for joining polymeric components

Laser welding of polymers is a very popular industrial joining process, creating joints with good mechanical performance. However, the implementation of optimized laser welding processes is still quite limited since most industrial applications adopt an empirical approach to adjust the process parameters. The current work provides a summary of new findings on the subject of laser joining of polymers, describing the key operation modes of this joining method, its process parameters and how they affect the joint characteristics. The response of polymers to temperatures generated during laser welding is also discussed, as well as the effect of additives on the weldability of polymers.

Atlas for a Warp Speed Future: Enhancing Usual Operating Modes of the U.S. Government

Operation Warp Speed (OWS) delivered new and effective vaccines to the general public in just 9 months, exploding previously held ideas about the government's role in medical countermeasure (MCM) development as well as what is possible on the timescale of vaccine development. OWS has potential to become a map for action in future pandemic crises. This article examines federal modes of governance that emerged in response to the Covid‐19 crisis, with special attention to how those modes differ from normal government operations. It is at the intersection of crisis modes of action and normal modes of operation that lessons emerge from OWS that may be worth applying in normal times – or not.In “Rules for Operating at Warp Speed,” I outlined how the leadership of OWS was able to accelerate operations under a suspension of the government's usual modes of operation (Arnold, 20201). This included suspension of rules that normally govern transparent and robust federal contracting and relaxing standards for scientific consensus‐building and expertise across government. This article draws from interviews completed in 2020 and 2021 with senior officials at the Department of Defense (DOD), Food and Drug Administration (FDA), and the White House in order to identify the key pandemic modes of action contributing to the success of OWS. It also discusses whether (and how) those modes of action might be adapted to enhance critical infrastructure preparedness in non‐crisis times.

QI Project Promoting NP Compliance with an AOM Bundle in Pediatric Hospital-owned Retail Clinic.

Introduction:The most common diagnosis for pediatric antibiotic prescriptions is acute otitis media (AOM). Therefore, it is logical to focus on AOM when striving to improve antibiotic prescribing in pediatrics. This quality improvement project aimed to improve documentation of diagnostic criteria and physical examination findings in the medical record and improve adherence to recommended antibiotic prescribing recommendations for AOM by nurse practitioners at a children’s hospital-owned pediatric retail clinic.Methods:We used The Institute for Healthcare Improvement’s Quality Improvement methodology to introduce an AOM quality bundle to providers in a pediatric retail clinic. We created Plan-Do-Study-Act ramps and implemented interventions, including NP education, electronic medical record improvements, and parent engagement. The percentage of compliant bundles (all five specific predetermined criteria successfully met) was measured for all patients diagnosed with AOM.Results:Baseline AOM bundle compliance began at a mean of 42%. Pareto analysis of baseline data indicated that antibiotic choice and duration were key failure modes. Antibiotic choice or duration errors occurred in 48% of reviewed charts at project inception. The interventions introduced throughout the project led to steady improvement in the percent of compliant bundles. The goal of 95% compliant bundles was achieved and maintained. At the project’s conclusion, 98% of antibiotic prescriptions were accurate.Conclusions:Implementation of multiple interventions with increasing levels of reliability improved the overall quality of documentation and increased the appropriate antibiotic prescriptions provided for patients diagnosed with AOM and seen by nurse practitioners at the retail clinic.

Facile hydrothermal synthesis of MXene@antimony nanoneedle composites for toxic pollutants removal

A new 2D transition metal carbides family noted that MXene with antimony (Sb) nano-needles composites have demonstrated potential applications for photocatalytic dye degradations applications. Single-step synthesis of novel structures two/one-dimensional MXene@antimony nanoneedle (MX@Sb–H) nanocomposite-based photocatalysts is produced employing hydrothermal technique. The preparations and characterizations were compared with hand mixture preparations of pure TiO2@Sb and MXene (MX@Sb-M). The crystallographic structure was identified employing X-ray diffraction (XRD) studies and main sharp XRD peaks were observed with diffraction angle with orientations planes for all three samples TiO2@Sb, MX@Sb-M and MX@Sb–H. The micro-Raman spectroscopy explored key vibration modes centered at 151.72 and 637.52 cm−1 corresponding to Ti and Sb hybrid composites respectively. Fourier transform infrared spectroscopy (FTIR) spectrum of functional group peaks at 609.16 and 868.80 cm−1 revealed Ti–OH/Sb–O–C stretching. The morphological investigations of horizontal growth for “Sb” nanoneedle on MXene nanosheets were explored by scanning electron microscopy (SEM). The degradation efficiency was calculated. The efficiency calculated were 27%, 38%, 68% and 82% for MB solution, TiO2@Sb added MB, MX-Sb-M added MB and MX-Sb-H added MB solution and the efficiency were 32%, 38%, 50% and 65% for pure RhB solution, TiO2@Sb added RhB, MX-Sb-M added RhB and MX-Sb-H added RhB solution. The photocatalytic activity of TiO2@Sb, MX@Sb-M and MX@Sb–H was examined. Among these MX@Sb–H nanocomposite was demonstrated the high photocatalytic action in expressions of rate stability of photocatalytic dye degradations.

Excited state structural evolution in fluorescent proteins and their model chromophores

The discovery of green fluorescent protein (GFP) has revolutionized molecular and cellular biology. Photocycle in wt-GFP involves generation of a bright fluorescent deprotonated chromophore from feebly fluorescent protonated form via excited-state proton transfer (ESPT). The chromophore loses its fluorescence outside the protein matrix due to ultrafast structural changes (ring twisting motion) during ESPT. To identify the key vibrational modes leading to such structural changes, we recently demonstrated how a systematic analysis of spectral data from non-resonant/resonant impulsive excitation followed by spectral dispersion disentangles vibrations arising in ground/excited electronic states of solute and solvent.

Non-uniform catalyst distribution in fixed-bed reactors to improve dehydrogenation processes

In the design and operation of industrial dehydrogenation reactors, loss of selectivity and catalyst deactivation caused by undesirable by-products are two critical issues. The hypothesis explored in this work has been that it is possible to address these matters by distributing the catalyst non-uniformly in the reactors. However, these constraints are characteristics of large reactors and only observable in that scale, thus testing the proposed hypothesis by experiments in the laboratory would be of limited value. A practical approach is to study the validity of this idea by process simulation. This method allows exploring a varied range of parameters and reveals the qualitative trends when experimenting with large-scale reactors is not feasible. In this study, a comprehensive process simulator is developed for dehydrogenation reactors, allowing the implementation of several catalyst distributions. The simulator includes options for both dissociative and non-dissociative dehydrogenation, with detailed reaction steps, key modes of species mass transfer, and the capability for parametric studies with a wide range of non-uniform patterns that are needed for optimization of catalyst distribution for a specific case. The simulator is also used for exploring other options such as the use of segmented beds with gaps in packing, or the introduction of hydrogen at various locations in the reactor. Results show that it is possible to improve the reactor yield and enhance the catalyst life by using a preferred non-uniform distribution of catalyst. Simulation results also show that the use of hydrogen injection into the segmented catalyst bed is an effective technique for improving the reactor performance and catalyst life, but the injection needs to be at a location inside the reactor and not at the inlet.