Surface Modification on Nickel Rich Cathode Materials for Lithium-Ion Cells: A Mini Review.

Nickel-rich (Ni-rich) layered oxides are considered as the most promising cathode candidates for lithium-ion cells owing to their high theoretical specific capacity. However, the higher nickel content endows structural deformation through unwanted phase transitions and parasitic side reactions that lead to capacity fading upon prolonged cycling. Hence, a deep understanding of the chemistry and structural behaviour is essential for developing Ni-rich Lithium Nickel Cobalt Manganese oxide (NCM) cathode-based high-energy batteries. The present review focuses on the different challenges associated with Ni-rich NCM materials and surface modification as a strategy to solve the issues associated with NCM materials, assessment of several coating materials, and the recent developments in the surface modification of Ni-rich NCMs, with an in-depth discussion on the impact of coating on the degradation mechanism.

Prediction of passing probability and risk evaluation along undivided road under heterogeneous traffic.

This study focuses on the safety part of the passing manoeuvre. Passing is considered as one of the most complex, unavoidable and challenging manoeuvres on two lane roads. A binary logistic regression model was developed to determine the probability of passing or aborting based on field data. The result shows that the probability of passing is affected by the factors such as speed of passing vehicle, speed of overtaken vehicle, speed of opposing vehicle, clearance time, and the total passing time. Risk assessment is an important aspect which should be addressed while assessing the passing operations. In the present study, a risk chart was developed based on clearance time and vehicle interaction. An overall risk table was developed for all possible combinations of risk. The study revealed that the selected road stretch along NH-66 in Kerala, India is more susceptible to passing crashes due to insufficient clearance time. This paper brings out a rational methodology for calculating a safety measure in terms of risk index factor which could be used in simulation softwares for adequate passing sight distance operational analysis.

Female Caregivers and Stroke Severity Determines Caregiver Stress in Stroke Patients.

BACKGROUND: Stroke is among the major causes of short- and long-term disability. This study aimed to understand the caregivers (CGs) stress in stroke survivors. MATERIALS AND METHODS: A 22-item questionnaire was administered to 201 CGs of stroke survivors. The variables tested were physical and mental health, social support, financial, and personal problems. CGs were divided into Group A (Barthel index [BI] <75) and B (BI >75) according to patient's BI, according to gender (male and female CG) and relation; spouses (wife, husband), daughters, sons, daughter-in-law, grandchildren, and rest (father, mother, brother, sister, and in-laws). Data were analyzed using SPSS software version-21. Data were analyzed to determine which variables of the patient effects the CG stress. RESULTS: Majority of the CGs (74.62%) were females. 65% of CGs graded their burden as moderate to severe. 81% of CGs had left their work for caregiving. More than half of the CGs felt sleep disturbance and physical strain. Psychological instability and financial burdens were reported in 3/4th of CGs. Group A CGs faced more sleep, financial, health, and social life disturbance. Patient's bladder and bowel problems, shoulder pain, patients noncooperative attitude for medication administration, and physiotherapy were more upsetting for Group A CGs. Female CGs were subjected to more sleep disturbance, physical and psychological stress, faced more difficulty regarding the patient's bladder, bowel, personal hygiene needs, and physiotherapy. Female CGs felt less motivated in caregiving than male CGs. Wives and daughters-in-law experienced more burden. Time spent and burden perceived was more by female CGs (χ2 = 15.199, P = 0.002) than males (χ2 = 11.931, P = 0.018); wives and daughters than other relations (χ2 = 32.184, P = 0.000), (χ2 = 35.162, P = 0.019). CONCLUSION: Our study showed that caregiving burden was predominantly shouldered by females CGs. CGs faced physical, psychological, and socioeconomic burden. The burden was more evident in female CGs and in patients with severe stroke.

Nonparallel Stacks of Donor and Acceptor Chromophores Evade Geminate Charge Recombination.

We report a nonparallel stacked arrangement of donor­acceptor (D­A) pairs for prolonging the lifetime of photoinduced charge-separated states. Hydrogen­hydrogen steric repulsion in naphthalimide-naphthalene (NIN) dyad destabilizes the planar geometry between the constituent units in solution/ground state. Sterically imposed nonplanar geometry of the dyad allows the access of nonparallel arrangement of the donor and acceptor stacks having triclinic space group in the crystalline state. Antiparallel trajectory of excitons in nonparallel D­A stacks can result in lower probability of geminate charge recombination, upon photoexcitation, thereby resulting in a long-lived charge-separated state. Upon photoexcitation of the NIN dyad, electron transfer from naphthalene to the singlet excited state of naphthalimide moiety results in radical ion pair intermediates that survive >10,000-fold longer in the aggregated state (τcra > 1.2 ns) as compared to that of monomeric dyad (τcrm < 110 fs), monitored using femtosecond transient absorption spectroscopy.

AIEE phenomenon: tetraaryl vs. triaryl pyrazoles.

Tetraarylpyrazoles are synthesized from commercially available materials in three steps and found to exhibit Aggregation Induced Emission Enhancement (AIEE) characteristics. Removing one aryl unit from tetraarylpyrazole leads to Aggregation Caused Quenching (ACQ), thus the number of aryl groups plays an important role in exploring such a phenomenon.

Syntheses of normal, expanded, strapped and N-confused calixbenzophyrins from a single starting material.

The syntheses and spectral and structural characterization of hitherto unknown p-benzene incorporated normal, expanded, strapped and N-confused calixbenzophyrins are achieved; altogether five new macrocycles from a single starting material are reported. The binding studies of the strapped macrocycle revealed that the molecule is selective towards Fe(III) ions.

Fluorine interaction controlled AIEE phenomenon in an expanded calixbenzophyrin and its vapoluminescent response: turn on emission with volatile ketones and esters.

Fluorine interaction assisted AIEE characteristic in an expanded calixbenzophyrin is presented by single-crystal X-ray-diffraction analysis and molecular modelling approaches. Selective exposure to volatile organic compounds such as ketones and esters results in the breaking of fluorine interaction, leading to enhanced monomer emission.

4,4,9,9-Tetraphenyl pyrroloindolizine: a structural analogue of calix[2]pyrrole.

Synthesis, spectral and structural characterization of a pyrroloindolizine derivative having structural similarity with calix[2]pyrrole is described. Here, two pyrrole rings are connected with two meso-carbon atoms having an N,α-linkage and an α,ß-linkage to afford the smallest analogue in the calixpyrrole family. Detailed NMR spectroscopic studies along with single crystal X-ray analysis confirm the assigned structure of the molecule.