Repellent activity of Vitex negundo and Curcuma longa herbal extract against simulium species in India.

BACKGROUND OBJECTIVES: At present the use of synthetic pesticides to manage insects and other arthropods creates a number of issues that are related to the environment and public health. The goal of the present study was to find the repellent activity of Vitex negundo and Curcuma longa herbal extract against the wild species Simulium (blackfly) bite. METHODS: We have studied Simulium biting behavior and tested the repellency of herbal extract obtained from Vitex negundo L. (Lamiales: Lamiaceae) and Curcuma lonaga L. (Zingiberal: Zingiberaceae) along with their essential oils in three locations in Arunachal Pradesh, India on human volunteers' resistance to Simulium (blackflies). The reported herbal extracts were incorporated to topical drug delivery vehicle as a cream and gel. RESULTS: The methanolic extract of Vitex negundo cream and gel formulation showed >2 h safety at 5% concentration and >5 h safety at 10% concentration at all the testing sites followed by ethyl acetate extract. Whereas, chloroform extract of Curcuma longa cream and gel formulation provided >1 h safety at 5% concentration and >4 h safety at 10% concentration. INTERPRETATION CONCLUSION: At an optimum concentration of 10%, the methanolic extract of vitex negundo cream provided complete protection times (CPTs) 320.4, 358.6, and 346.4 minutes, respectively. This finding offers confirmation of the methanolic extract and chloroform extract potential for use in new blackfly repellents.

Mesoporous Single Atom-Cluster Fe-N/C Oxygen Evolution Electrocatalysts Synthesized with Bottlebrush Block Copolymer-Templated Rapid Thermal Annealing.

Current electrocatalysts for oxygen evolution reaction (OER) are either expensive (such as IrO2, RuO2) or/and exhibit high overpotential as well as sluggish kinetics. This article reports mesoporous earth-abundant iron (Fe)-nitrogen (N) doped carbon electrocatalysts with iron clusters and closely surrounding Fe-N4 active sites. Unique to this work is that the mechanically stable mesoporous carbon-matrix structure (79 nm in pore size) with well-dispersed nitrogen-coordinated Fe single atom-cluster is synthesized via rapid thermal annealing (RTA) within only minutes using a self-assembled bottlebrush block copolymer (BBCP) melamine-formaldehyde resin composite template. The resulting porous structure and domain size can be tuned with the degree of polymerization of the BBCP backbone, which increases the electrochemically active surface area and improves electron transfer and mass transport for an effective OER process. The optimized electrocatalyst shows a required potential of 1.48 V (versus RHE) to obtain the current density of 10 mA/cm2 in 1 M KOH aqueous electrolyte and a small Tafel slope of 55 mV/decade at a given overpotential of 250 mV, which is significantly lower than recently reported earth-abundant electrocatalysts. Importantly, the Fe single-atom nitrogen coordination environment facilitates the surface reconstruction into a highly active oxyhydroxide under OER conditions, as revealed by X-ray photoelectron spectroscopy and in situ Raman spectroscopy, while the atomic clusters boost the single atoms reactive sites to prevent demetalation during the OER process. Density functional theory (DFT) calculations support that the iron nitrogen environment and reconstructed oxyhydroxides are electrocatalytically active sites as the kinetics barrier is largely reduced. This work has opened a new avenue for simple, rapid synthesis of inexpensive, earth-abundant, tailorable, mechanically stable, mesoporous carbon-coordinated single-atom electrocatalysts that can be used for renewable energy production.

Promising Phytoconstituents in Diabetes-related Wounds: Mechanistic Insights and Implications.

BACKGROUND: The onset of diabetes mellitus (DM), a metabolic disorder characterized by high blood glucose levels and disrupted glucose metabolism, results in 20% of people with diabetes suffering from diabetes-related wounds worldwide. A minor wound, such as a cut or abrasion, can lead to infections and complications in diabetic patients. We must understand the mechanism/s contributing to this delayed wound healing to develop effective prevention strategies. The potential benefits of bioactive phytochemicals for diabetic wound healing have been reported in numerous studies. METHOD: A bioactive compound may have multiple actions, including antioxidants, antiinflammatory, antimicrobial, and angiogenesis. Compounds derived from these plants have shown promising results in wound healing, inflammation reduction, collagen synthesis, and neovascularization improvement. RESULTS: Consequently, this review provides an update to our understanding of how phytoconstituents promote wound healing in diabetics. A thorough literature review was conducted on diabetes, wound healing, and phytoconstituents for this study. Only English publications until June 2023 were included in the search, which used multiple search engines and the main keywords. Summing up, phytochemical-based interventions might improve the quality of life for diabetics by improving wound healing. CONCLUSION: However, to fully understand the efficacy and safety of these phytochemicals in managing diabetic wounds, more research and clinical trials are needed.

Exploration of the anti-diabetic potential of hydro-ethanolic leaf extract of Koenigia polystachya L.: an edible wild plant from Northeastern India.

BACKGROUND: Globally, medicinal plants are used to treat diseases like diabetes. The present study evaluates the possible antioxidant, acute oral toxicity, the in-vitro and in-vivo antidiabetic potential of the hydro-ethanolic leaf extract of Koenigia polystachya (HELeKP) against beta-cell damage in experimentally induced diabetes mellitus. The DPPH (2,2-diphenyl-1-picrylhydrazine), ABTS [2,2'-azino bis-(3-ethylbenzothiazoline-6-sulfonic acid)], H2O2 (Hydrogen peroxide), superoxide radical scavenging activity and NO (Nitric oxide) assay estimated the in-vitro antioxidant assay of HELeKP. The acute oral toxicity study was evaluated per the OECD (Organization for Economic Cooperation and Development) test guidelines 425. Diabetes was stimulated in rats with a single dose of Streptozotocin (STZ), and after confirmation of diabetes, HELeKP was given orally for 21 days. Blood/serum samples were gathered and examined for biochemical changes, while tissue samples were evaluated for histopathological alterations. RESULTS: The IC50 value of the HELeKP for all the anti-oxidant assays confirms the free radical scavenging activity. The data on acute oral toxicity revealed that the HELeKP used in the study was comparatively very safe. The outcomes of the in-vivo study suggested that the extract significantly reduced (p < 0.001) the fasting glucose level in STZ-induced diabetic rats. Furthermore, the lipid profile level was significantly normalized (p < 0.01, p < 0.001) in diabetic rats. The histopathological observation of the pancreas in HELeKP-treated rats showed significant beta-cell restoration. CONCLUSIONS: Based on the outcomes of this study, the HELeKP-treated rats have significant free radical scavenging and anti-diabetic potential. Therefore, it can be recommended as a beneficial functional vegetable for consumption.

Noninvasive and Contactless Characterization of Electronic Properties at the Semiconductor/Dielectric Interface Using Optical Second-Harmonic Generation.

Optical second-harmonic generation (SHG) is a reliable technique for probing material surface and interface characteristics. Here, we have demonstrated a non-destructive, contactless SHG-based semiconductor/dielectric interface characterization method to measure the conduction band offset and quantitatively evaluate charge densities at the interface in oxide and at the oxide surface. This technique extracts the interface-trapped charge type (donor/acceptor) and qualitatively analyzes the process-induced variation in interface states (Dit), oxide, and oxide surface state density. These qualitative and quantitative analyses provide us with a glimpse into the band bending. The metrology method is validated through a detailed characterization of the Si/HfO2 interface. An optical setup has been developed to monitor the time-dependent second-harmonic generation (TDSHG) from the semiconductor/oxide interface. The temporal characteristics of TDSHG are explained with its relationship to the filling of Dit and spatio-temporal trapping of photoexcited charge in oxide and at the oxide surface. A numerical solver, based on plausible carrier dynamics, is used to model the experimental data and to extract the electronic properties at the Si/HfO2 interface.

A delve into the pharmacological targets and biological mechanisms of Paederia foetida Linn.: a rather invaluable traditional medicinal plant.

Drug development from herbal medicines or botanical sources is believed to have a prominent role in the exploration of novel counteractive drugs that has sparked much interest in recent times. Paederia foetida is one such medicinal plant used in both traditional and folkloric medicine. Several parts of the herb are locally utilised as a natural curative agent for several ailments since time immemorial. Paederia foetida indeed possesses anti-diabetic, anti-hyperlipidaemic, antioxidant, nephro-protective, anti-inflammatory, antinociceptive, antitussive, thrombolytic, anti-diarrhoeal, sedative-anxiolytic, anti-ulcer, hepatoprotective activity, anthelmintic and anti-diarrhoeal activity. Furthermore, growing evidence shows many of its active constituents to be effective in cancer, inflammatory diseases, wound healing and spermatogenesis as well. These investigations shed light on possible pharmacological targets and attempts to establish a mechanism of action for these pharmacological effects. These findings contrast the significance of this medicinal plant for further research and for the exploration of novel counteractive drugs to establish a mechanism of action before being employed to healthcare. Pharmacological activities of Paederia foetida and their mechanism of action.

Atypical performance of CoO-accelerated interface tweaking in hierarchical cobalt phosphide/oxide@P-doped rGO heterostructures for hybrid supercapacitors.

Designing two-dimensional (2D) heterostructures based on suitable energy materials is a promising strategy to achieve high-performance supercapacitors with hybridized transition metal and carbonaceous-based electrodes. The influence of each component and its content on the capacitor performance necessitates deeper insights. In this study, a 2D/2D heterostructure made of hierarchical pseudocapacitive cobalt phosphide/oxide and P-doped reduced graphene oxide (PrGO) nanosheets (CoP/CoO@PrGO) was fabricated using porous zeolitic-imidazolate framework precursor. The decoration of 2D leaf-like CoP/CoO hybrid onto PrGO could create a unique interface with a large number of active sites, CoO-driven creation of pseudocapacitive surface POx species, and high P content (∼3 at.%) in PrGO, thus promoting the Faradaic reaction, electrical conductivity, and overall charge storage. This framework yields a high specific capacitance of 405 F g-1 at 5 A g-1 and excellent cycling stability (over 100 % after 10,000 cycles), superior to those of pristine CoP@PrGO (300 F g-1 at 5 A g-1). Furthermore, the fabricated asymmetric supercapacitor delivers reasonable energy density of 4.2 Wh kg-1 at a power density of 785 W kg-1 and cycling stability of âˆ¼100 % after 10,000 cycles. Therefore, CoP/CoO@PrGO with its unique interfacial properties can promote the development of heterostructure electrode for high-performance supercapacitors.

Potential injectable hydrogels as biomaterials for central nervous system injury: A narrative review.

Numerous modalities exist through which the central nervous system (CNS) may sustain injury or impairment, encompassing traumatic incidents, stroke occurrences, and neurodegenerative diseases such as Alzheimer's disease and Parkinson's disease. Presently available pharmacological and therapeutic interventions are incapable of restoring or regenerating damaged CNS tissue, leading to substantial unmet clinical needs among patients with CNS ailments or injuries. To address and facilitate the recovery of the impaired CNS, cell-based repair strategies encompass multiple mechanisms, such as neuronal replacement, therapeutic factor secretion, and the promotion of host brain plasticity. Despite the progression of cell-based CNS reparation as a therapeutic strategy throughout the years, substantial barriers have impeded its widespread implementation in clinical settings. The integration of cell technologies with advancements in regenerative medicine utilizing biomaterials and tissue engineering has recently facilitated the surmounting of several of these impediments. This comprehensive review presents an overview of distinct CNS conditions necessitating cell reparation, in addition to exploring potential biomaterial methodologies that enhance the efficacy of treating brain injuries.

Simplified inelastic electron tunneling spectroscopy based on low-noise derivatives.

A standard experimental setup for Inelastic Electron Tunneling Spectroscopy (IETS) performs the measurement of the second derivative of the current with respect to the voltage ([Formula: see text]) using a small AC signal and a lock-in based second harmonic detection. This avoids noise arising from direct differentiation of the current-voltage characteristics (I-V) by standard numerical methods. Here we demonstrate a noise-filtering algorithm based on Tikhonov Regularization to obtain IET spectra (i.e. [Formula: see text] vs. V) from measured DC I-V curves. This leads to a simple and effective numerical method for IETS extraction. We apply the algorithm to I-V data from a molecular junction and a metal-insulator-semiconductor tunneling device, demonstrating that the computed first/second derivatives have a workable match with those obtained from our lock-in measurements; the computed IET spectral peaks also correlate well with reported experimental ones. Finally, we present a scheme for automated tuning of the algorithm parameters well-suited for the use of this numerical protocol in real applications.

Real-time observation of delayed excited-state dynamics in InGaN/GaN quantum-wells by femtosecond transient absorption spectroscopy.

This work employs femtosecond transient absorption spectroscopy to investigate the ultrafast carrier dynamics of bound states in In0.14Ga0.86N/GaN quantum wells. The ground state (GS) dynamics usually dominate these characteristics, appearing as a prominent peak in the absorption spectra. It is observed that the excited state also contributes to the overall dynamics, with its signature showing up later. The contributions of both the ground and excited states in the absorption spectra and time-resolved dynamics are decoupled in this work. The carrier density in the GS first increases and then decays with time. The carriers populate the excited state only at a delayed time. The dynamics are studied considering the Quantum-Confined Stark Effect-induced wavelength shift in the absorption. The relevant microscopic optoelectronic processes are understood phenomenologically, and their time constants are extracted. An accurate study of these dynamics provides fundamentally essential insights into the time-resolved dynamics in quantum-confined heterostructures and can facilitate the development of efficient light sources using GaN heterostructures.

Effect of deletions in the α-globin gene on the phenotype severity of ß-thalassemia.

Thalassemia is the most common inherited hemoglobinopathy worldwide. Variation of clinical symptoms in this hemoglobinopathy entails differences in disease-onset and transfusion requirements. The aim of this study was to investigate the role of α-globin gene deletions in modulating the clinical heterogeneity of ß-thalassemia (ß-thal) syndromes. A total number 270 ß-thal subjects were enrolled. Hematological parameters were recorded. ß-Globin mutations were determined by amplified refractory mutation system-polymerase chain reaction (ARMS-PCR), gap-PCR and Sanger sequencing. α-Globin gene deletions were determined by multiplex PCR. Out of 270 ß-thal subjects, 19 carried ß+/ß+, 74 had ß0/ß0 and 177 had the ß0/ß+ genotype. When we determined the severity of the different ß-thal subjects in coinherited with the α gene deletion, it was revealed that, 84.2% ß+/ß+ subjects carried a non severe phenotype and did not have an α gene deletion. Of the ß0/ß0 individuals, 95.9% presented a severe phenotype, irrespective of α-globin gene deletions. In cases with the ß0/ß+ genotype, 19.2% subjects also carried a deletion on the α gene. Of these, 61.8% presented a non severe phenotype and 38.2% were severely affected. Only in the ß0/ß+ category did α gene deletions make a significant contribution (p < 0.001) toward alleviation of clinical severity. Therefore, it can be stated that α-globin gene deletions play a role in ameliorating the phenotype in patients with a ß+/ß0 genotype.

Reduced Auger Coefficient through Efficient Carrier Capture and Improved Radiative Efficiency from the Broadband Optical Cavity: A Mechanism for Potential Droop Mitigation in InGaN/GaN LEDs.

Efficiency droop at high carrier-injection regimes is a matter of concern in InGaN/GaN quantum-confined heterostructure-based light-emitting diodes (LEDs). Processes such as Shockley-Reed-Hall and Auger recombinations, electron-hole wavefunction separation from polarization charges, carrier leakage, and current crowding are identified as the primary contributors to efficiency droop. Auger recombination is a critical contributor owing to its cubic dependence on carrier density, which can not be circumvented using an advanced physical layout. Here, we demonstrate a potential solution through the positive effects from an optical cavity in suppressing the Auger recombination rate. Besides the phenomenon being fundamentally important, the advantages are technologically essential. The observations are manifested by the ultrafast transient absorption pump-probe spectroscopy performed on an InGaN/GaN-based multi-quantum well heterostructure with external DBR mirrors of varying optical confinement. The optical confinement modulates the nonlinear carrier and photon dynamics and alters the rate of dominant recombination mechanisms in the heterostructure. The carrier capture rate is observed to be increasing, and the polarization field is reducing in the presence of optical feedback. Reduced polarization increases the effective bandgap, resulting in the suppression of the Auger coefficient. Superluminescent behavior along with enhanced spectral purity in the emission spectra in presence of optical confinement is also demonstrated. The improvement is beyond the conventional Purcell effect observed for the quantum-confined systems.

Tuning the Chemical and Mechanical Properties of Conductive MoS2 Thin Films by Surface Modification with Aryl Diazonium Salts.

Molybdenum disulfide (MoS2) is a promising material for applications in sensors, energy storage, energy conversion devices, solar cells, and fuel cells. Because many of those applications require conductive materials, we recently developed a method for preparing a conductive form of MoS2 (c-MoS2) using dilute aqueous hydrogen peroxide in a simple and safe way. Here, we investigate modulating the chemical and mechanical surface properties of c-MoS2 thin films using diazonium chemistry. In addition to a direct passivation strategy of c-MoS2 with diazonium salts for electron-withdrawing groups, we also propose a novel in situ synthetic pathway for modification with electron-donating groups. The obtained results are examined by Raman spectroscopy and X-ray photoelectron spectroscopy. The degree of surface passivation of pristine and functionalized c-MoS2 films was tested by exposing them to aqueous solutions of different metal cations (Fe2+, Zn2+, Cu2+, and Co2+) and detecting the chemiresistive response. While pristine films were found to interact with several of the cations, modified films did not. We propose that a surface charge transfer mechanism is responsible for the chemiresistive response of the pristine films, while both modification routes succeeded at complete surface passivation. Functionalization was also found to lower the coefficient of friction for semiconducting 2H-MoS2, while all conductive materials (modified or not) also had lower coefficients of friction. This opens up a pathway to a palette of dry lubricant materials with improved chemical stability and tunable conductivity. Thus, both in situ and direct diazonium chemistries are powerful tools for tuning chemical and mechanical properties of conductive MoS2 for new devices and lubricants based on conductive MoS2.

First-principles based simulations of electronic transmission in ReS2/WSe2 and ReS2/MoSe2 type-II vdW heterointerfaces.

Electronic transmission in monolayer ReS[Formula: see text] and ReS[Formula: see text] based van der Waals (vdW) heterointerfaces are studied here. Since ReS[Formula: see text]/WSe[Formula: see text] and ReS[Formula: see text]/MoSe[Formula: see text] type-II vdW heterostructures are suitable for near infrared (NIR)/short-wave infrared (SWIR) photodetection, the role of interlayer coupling at the heterointerfaces is examined in this work. Besides, a detailed theoretical study is presented employing density functional theory (DFT) and nonequilibrium Green's function (NEGF) combination to analyse the transmission spectra of the two-port devices with ReS[Formula: see text]/WSe[Formula: see text] and ReS[Formula: see text]/MoSe[Formula: see text] channels and compare the near-equilibrium conductance values. Single layer distorted 1T ReS[Formula: see text] exhibits formation of parallel chains of 'Re'-'Re' bonds, leading to in-plane anisotropy. Owing to this structural anisotropy, the charge carrier transport is very much orientation dependent in ReS[Formula: see text]. Therefore, this work is further extended to investigate the role of clusterized 'Re'  atoms in electronic transmission.

Defect Engineering of Graphene to Modulate pH Response of Graphene Devices.

Graphene-based pH sensors are a robust, durable, sensitive, and scalable approach for the sensitive detection of pH in various environments. However, the mechanisms through which graphene responds to pH variations are not well-understood yet. This study provides a new look into the surface science of graphene-based pH sensors to address the existing gaps and inconsistencies among the literature concerning sensing response, the role of defects, and surface/solution interactions. Herein, we demonstrate the dependence of the sensing response on the defect density level of graphene, measured by Raman spectroscopy. At the crossover point (ID/IG = 0.35), two countervailing mechanisms balance each other out, separating two regions where either a surface defect induced (negative slope) or a double layer induced (positive slope) response dominates. For ratios above 0.35, the pH-dependent induction of charges at surface functional groups (both pH-sensitive and nonsensitive groups) dominates the device response. Below a ratio of 0.35, the response is dominated by the modulation of charge carriers in the graphene due to the electric double layer formed from the interaction between the graphene surface and the electrolyte solution. Selective functionalization of the surface was utilized to uncover the dominant acid-base interactions of carboxyl and amine groups at low pH while hydroxyl groups control the high pH range sensitivity. The overall pH-sensing characteristics of the graphene will be determined by the balance of these two mechanisms.

Gradual Carrier Filling Effect in "Green" InGaN/GaN Quantum Dots: Femtosecond Carrier Kinetics with Sequential Two-Photon Absorption.

Quantum dots (QDs) allow for a significant amount of strain relaxation, which is helpful in GaN systems where a large lattice mismatch needs to be accommodated. InGaN QDs with a large indium composition are intensively investigated for light emitters requiring longer wavelengths. These are especially important for developing high-efficiency white light sources. Understanding the carrier dynamics in this large lattice-mismatched system is essential to improving the radiative efficiency while circumventing high defect density. This work investigates femtosecond carrier and photon dynamics in self-organized In0.27Ga0.73N/GaN QDs grown by molecular beam epitaxy using transient differential absorption spectroscopy, which measures the differential absorption coefficient (Δα) with and without an optical pump. Due to 3D quantum confinement and the small effective mass of InGaN, the low density of states in the conduction band is easily filled with electrons. In contrast, the GaN barrier region is replete with a high density of electrons due to a large effective mass. This contrast in carrier density creates a unique phenomenon in the dynamics, showing a change in the differential absorption coefficient (Δα) sign from negative to positive with time. The ultrafast microscopic processes indicate that right after the optical pump and first photon absorption, the valence (conduction) band states are depleted (replete) of electrons. This ground-state bleaching process makes Δα negative, and the probe beam is not absorbed. The electrons are then gradually transferred from the GaN barrier into InGaN QDs, which absorb the second photon from the probe beam (excited-state absorption), making Δα positive. The presence of excited-state carriers with a long lifetime is indicative of the enhanced availability of carriers for radiative recombination. This effect also promotes stimulated emission and amplified spontaneous emission, which can be used to develop lasers and superluminescent LEDs, respectively. Measurements with multiple pump powers and temperatures further confirm that the efficacy of InGaN QDs is enhanced by this effective mass contrast and 3D reservoir of carriers from the GaN barrier. This effect can be used to improve the internal quantum efficiency of GaN-based light emitters.

Drug Repurposing: Hydroxyurea Therapy Improves the Transfusion-Free Interval in HbE/Beta-Thalassemia-Major Patients with the XmnI Polymorphism.

Aims: HbE/ß-thalassemia is the most prevalent form of severe ß-thalassemia in Asian countries. Hydroxyurea (HU) is the most common drug used for the management of sickle-cell anemia but not thalassemia. In this study, we aimed to assess clinical HU response among the Bengali HbE/ß-thalassemia patients with respect to the XmnI γGglobin polymorphism and elucidate the association between this polymorphism and HU response efficacy. Materials and Methods: We enrolled 49 transfusion-dependent patients with HbE/ß-thalassemia. Fetal hemoglobin levels were measured using high-performance liquid chromatography and complete blood counts were determined pre- and post-HU therapy. Polymerase chain reaction-restriction fragment length polymorphism analyses were performed for genotyping the XmnI γGglobin polymorphism. Results: A total of 30 (61.22%) patients were found to be responders, whereas the remaining 19 (38.78%) were nonresponders. We found 33 patients with the heterozygous (C/T) and three with the homozygous mutant (T/T) genotype status. We obtained a statistically significant correlation (p < 0.001) between the XmnI polymorphism genotype and transfusion-free interval. Patients with the XmnI polymorphism were found to be good responders for HU therapy and showed increased hemoglobin levels. Conclusions: Our findings indicate that HU is a potential drug candidate for thalassemia management, particularly for HbE/ß-thalassemia. These results hold implications in repurposing HU as an effective and efficient therapy for HbE/ß-thalassemia.

Low-field mobility in an electrostatically confined 2D rectangular nanowire: effect of density of states and phonon confinement.

Transport in GaN-based nanoscale devices is of supreme importance for various applications. While the transport in bulk and two-dimensional (2D) structures is relatively well understood, understanding one-dimensional (1D) transport is still at its nascent stage. More importantly, the nanoscale structures may not operate at an explicit dimension of 2D and 1D. The understanding of the transport becomes limited on such an occasion. Here, we investigate the evolution of low-field mobility in GaN-based nanostructures for increasing quantum confinement in a uniform framework. We have used a split-gate architecture to change the degree of quantum confinement electrostatically. The low-field mobility is experimentally determined, which is then matched using scattering theory. It is shown that acoustic phonon, polar optical phonon, and scattering from piezoelectric fields dominate these devices. Contrary to intuition, the piezoelectric fields play the most determining role in low-field regimes. In addition, the evolving density of states and 2D phonon confinement, in addition to electron confinement, lead to a non-monotonic change in mobility. A decrease in the number of states near conduction band minima tends to increase mobility by reducing the number of final scattering states for the electrons. A larger overlap between confined electrons and phonons aggravates scattering and reduces mobility. These two competing effects can lead to many possible values for mobility during device operation.

Critical insights into the effects of plastic pyrolysis oil on emission and performance characteristics of CI engine.

Pyrolysis is an encouraging solution considering the facts of energy demand and waste plastic management as it produces liquid fuel for compression ignition engine application. This study provides critical insights into the effects of waste plastic oil on the emission and performance characteristics of compression ignition engines. Though most of the studies have shown a negative influence, promising outcomes have been noticed in a few specific cases. A maximum of 71%, 80%, 76%, 71%, 21%, and 13% decrease in nitrogen oxide emission, carbon monoxide emission, unburnt hydrocarbon emission, smoke emission, exhaust gas temperature, and brake-specific fuel consumption, respectively, have been noticed with waste plastic oil or its blends at certain operating conditions. Nevertheless, the presence of long carbon chains, higher aromatic content, and non-homogeneous air-fuel mixture owing to the wide product distribution in plastic oil are the few reasons which affected the emission and performance characteristics of the engines. More rigorous investigations are needed to improve the quality of the fuel and to establish correlations between the fuel properties and pyrolysis parameters. In addition, the effects of incorporating exhaust gas recirculation, emulsification process, and use of additives with waste plastic oil need to be explored more for reducing the emissions with satisfactory engine performance, and in this regard, the use of bio-additives with waste plastic oil can provide a new direction to this research field. Further, studies on the economic feasibility and the impact of waste plastic oil on engine materials are also required.

Vibration-based biomimetic odor classification.

Olfaction is not as well-understood as vision or audition, nor technologically addressed. Here, Chemical Graph Theory is shown to connect the vibrational spectrum of an odorant molecule, invoked in the Vibration Theory of Olfaction, to its structure, which is germane to the orthodox Shape Theory. Atomistic simulations yield the Eigen-VAlue (EVA) vibrational pseudo-spectra for 20 odorant molecules grouped into 6 different 'perceptual' classes by odour. The EVA is decomposed into peaks corresponding to different types of vibrational modes. A novel secondary pseudo-spectrum, informed by this physical insight-the Peak-Decomposed EVA (PD-EVA)-has been proposed here. Unsupervised Machine Learning (spectral clustering), applied to the PD-EVA, clusters the odours into different 'physical' (vibrational) classes that match the 'perceptual', and also reveal inherent perceptual subclasses. This establishes a physical basis for vibration-based odour classification, harmonizes the Shape and Vibration theories, and points to vibration-based sensing as a promising path towards a biomimetic electronic nose.