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1.
Langmuir ; 40(15): 7812-7834, 2024 Apr 16.
Article in English | MEDLINE | ID: mdl-38587122

ABSTRACT

Interfacial properties, such as wettability and friction, play critical roles in nanofluidics and desalination. Understanding the interfacial properties of two-dimensional (2D) materials is crucial in these applications due to the close interaction between liquids and the solid surface. The most important interfacial properties of a solid surface include the water contact angle, which quantifies the extent of interactions between the surface and water, and the water slip length, which determines how much faster water can flow on the surface beyond the predictions of continuum fluid mechanics. This Review seeks to elucidate the mechanism that governs the interfacial properties of diverse 2D materials, including transition metal dichalcogenides (e.g., MoS2), graphene, and hexagonal boron nitride (hBN). Our work consolidates existing experimental and computational insights into 2D material synthesis and modeling and explores their interfacial properties for desalination. We investigated the capabilities of density functional theory and molecular dynamics simulations in analyzing the interfacial properties of 2D materials. Specifically, we highlight how MD simulations have revolutionized our understanding of these properties, paving the way for their effective application in desalination. This Review of the synthesis and interfacial properties of 2D materials unlocks opportunities for further advancement and optimization in desalination.

2.
Indian J Otolaryngol Head Neck Surg ; 75(2): 523-528, 2023 Jun.
Article in English | MEDLINE | ID: mdl-36540727

ABSTRACT

The aim of this study was to find out the association of sinonasal candidiasis and Covid-19 infection. A prospective observational study was conducted at a tertiary care centre from April to September 2021, involving all patients with invasive candidiasis of the paranasal sinuses having a history of Covid-19 infection. A total of 18 patients of covid associated sinonasal candidiasis among the 475 cases of fungal rhinosinusitis were studied. All patients had involvement of nose and sinuses and 2 patients had orbital involvement with no loss of vision, while 3 had intracranial extensions and 1 had pulmonary involvement. Mandible was involved in 1 patient alone, while the maxilla and palate were involved in 5 patients. 15 patients were hypertensive, 12 diabetics and 1 had aplastic anaemia. Cultures showed that 8 patients had C. parapsilosis, 5 had C. albicans, 3 had C. tropicalis and 2 had mixed fungal infections. All patients underwent surgical debridement and antifungal administration. They were followed up for a minimum of 3 months. There was only one mortality (with aplastic anaemia), rest 17 were disease free at the time of writing this article. This is perhaps the first case series of post covid sinonasal candidiasis in the world. Invasive sinonasal candidiasis is a newer sequela of COVID-19 infection. Uncontrolled diabetes and over-zealous use of steroids at the time of Covid-19 are few of the known risk factors. Early surgical intervention and anti-fungal treatment should be sought for management.

3.
Indian J Otolaryngol Head Neck Surg ; 75(2): 557-562, 2023 Jun.
Article in English | MEDLINE | ID: mdl-36571095

ABSTRACT

To study the possible association between invasive fungal sinusitis (aspergillosis) and coronavirus disease. An observational study was conducted at a tertiary care centre over 6 months, involving all patients with aspergillosis of the paranasal sinuses suffering from or having a history of COVID-19 infection. 92 patients presented with aspergillosis, all had an association with COVID-19 disease. Maxillary sinus (100%) was the most common sinus affected. Intraorbital extension was seen in 34 cases, while intracranial extension was seen in 5 cases. Diabetes mellitus was present in 75 of 92 cases. All had a history of steroid use during their coronavirus treatment. New manifestations of COVID-19 are appearing over time. The association between coronavirus and aspergillosis of the paranasal sinuses must be given serious consideration. Uncontrolled diabetes and overzealous use of steroids are two main factors aggravating the illness, and both of these must be properly checked.

4.
Mater Today Proc ; 79: 6-10, 2023.
Article in English | MEDLINE | ID: mdl-35946044

ABSTRACT

Due to the recent pandemic situation that has erupted all around us, healthcare facility design is a must. Healthcare providers and administrators must concentrate on the changes that must be made in existing healthcare facilities. The isolated healthcare facilities are essential because the corona virus is spread mainly through close contact (within six feet), such as handshaking (if someone's hands are infected) or touching contaminated surfaces. Healthcare facilities are most susceptible to the spread of the corona virus due to the high number of symptomatic patients admitted. Coronavirus is the leading cause of infectious disease morbidity and mortality worldwide. Thus, if the pandemic situation worsens, new plans and designs for existing healthcare facilities will be required, as well as temporary versions. Societal gains from increased research in this area. In the coming years, healthcare workers will be better trained, and healthcare facilities will be upgraded. This paper proposes new plans and designs to address the issues raised.

5.
Indian J Otolaryngol Head Neck Surg ; 74(Suppl 2): 1597-1604, 2022 Oct.
Article in English | MEDLINE | ID: mdl-36452847

ABSTRACT

Chronic inflammatory disorders of the upper airways are extremely prevalent and they have a major impact on public health.To assess the change in pulmonary function tests in patients of chronic rhinosinusitis undergoing functional endoscopic sinus surgery pre operatively and post operatively.To evaluate the difference in mean of FEV1, FEV1%, FVC, FVC%, FEV1/FVC in patients of chronic rhinosinusitis undergoing functional endoscopic sinus surgery.Prospective observational study.From July 2019 to September 2020 in Department of ENT and Head & Neck surgery, SMS Medical College, Jaipur.There was a significant improvement in the mean FEV1, FEV1%, FVC, and FVC% values post-surgically (p < 0.05). In our study, there was also a significant improvement in the FEV1/FVC value at one month postoperatively, reflecting the effect of FESS on relieving the symptomatic lower airway obstruction.Our study concludes that following Functional Endoscopic Sinus Surgery there is significant improvement in pulmonary function tests reflecting the improvement of asymptomatic lower airway disease in cases of chronic rhinosinusitis.

6.
PLoS One ; 17(8): e0268216, 2022.
Article in English | MEDLINE | ID: mdl-35981008

ABSTRACT

BACKGROUND: The Global Burden of Disease data suggest that respiratory diseases contribute to high morbidity in India. However, the factors responsible for high morbidity are not quite clear. Therefore, the Seasonal Waves Of Respiratory Disorders (SWORD) study was planned to estimate the point prevalence due to respiratory diseases in Indian OPD services and its association with risk factors and change in seasons. METHODS: In this point prevalence observational multicenter study conducted during 2017-18, participating physicians recorded information of consecutive patients in response to a questionnaire. The study was conducted on four predetermined days representing transition of Indian seasons i.e., February (winter), May (summer), August (monsoon), and November (autumn). RESULTS: The eligible number of patients from across 302 sites in India was 25,177. The mean age of study population was 46.1±18.1 years, 14102(56.0%) were males and 11075(44.0%) females. The common diagnoses were: asthma(29.8%), chronic obstructive pulmonary disease (COPD),15.6%, respiratory tract infections (RTIs),11.3%, and tuberculosis(8.7%). All these conditions showed significant seasonal trends (Asthma 31.4% autumn vs. 26.5% summer, COPD 21.1% winter vs. 8.1% summer, RTIs 13.3% winter vs. 4.3% summer, and tuberculosis 12.5% autumn vs. 4.1% summer, p<0.001 for each respectively). After adjustment for risk factors, asthma was significantly associated with exposure to molds (OR:1.12,CI:1.03-1.22), pet animals (OR:1.07,CI:1.01-1.14), recent-travel (OR:1.22,CI:1.13-1.32), and rain-wetting (OR:1.27,CI:1.15-1.40); and RTIs with rain-wetting (OR:1.53,CI:1.34-1.74), and recent-travel (OR:1.17,CI:1.05-1.30). CONCLUSIONS: The SWORD study showed wide seasonal variations in outpatient attendance of patients with common respiratory conditions. Novel risk-factors associated with respiratory diseases were also identified.


Subject(s)
Asthma , Pulmonary Disease, Chronic Obstructive , Respiration Disorders , Respiratory Tract Infections , Animals , Asthma/epidemiology , Female , Humans , Male , Pulmonary Disease, Chronic Obstructive/epidemiology , Respiration Disorders/epidemiology , Respiratory Tract Infections/epidemiology , Seasons , Surveys and Questionnaires
7.
J Assoc Physicians India ; 70(4): 11-12, 2022 Apr.
Article in English | MEDLINE | ID: mdl-35443334

ABSTRACT

The complex relationship between BMI, thyroid and its effects on OSA raises a question on how patients with suspected OSA should be evaluated. Some studies have described an association between thyroid disorders and OSA. Whether this is a direct effect of thyroid disorders, or it is indirectly related to BMI values is an important point to ponder. The aim of this study was to estimate the prevalence of thyroid disorders in relation to BMI in newly diagnosed patients with OSA (AHI > 5/h on diagnostic Polysomnography) at sleep lab of our tertiary care centre. In addition, we compared baseline characteristics of OSA patients with thyroid parameters. MATERIAL: In this hospital based observational study, recently diagnosed OSA on the basis of PSG showing AHI > 5/ h according to the AASM 2012 scoring rules and age more than 18 years were recruited from OPD and in-patients of SMS Medical College Jaipur. Patients on previous CPAP treatment, mixed or predominantly central sleep apnea, known diabetics and language barriers or cognitive or psychiatric disorders that made informed consent difficult to obtain were excluded. OBSERVATION: During the study period, 65 patients with treatment naïve OSA and a mean age of 52.28±10.92 year, a mean body mass index (BMI) of 34.73±7.20 kg/m2 underwent thyroid function tests. In the OSA patients, the prevalence of newly diagnosed clinical hypothyroidism was 12.3%. In Mild OSA the mean FT3 (ng/ml), FT4 (ng/dl), TSH (mIU/l) and mean AHI score was 3.10±0.71, 1.37±0.58, 3.64±1.37 and 7.74±3.55 respectively. Similarly, mean FT3 (ng/ml), FT4 (ng/dl), TSH (mIU/l) and mean AHI score were 2.97±0.93, 1.46±0.79, 6.33±8.05 and 17.42±88.90 respectively in moderate OSA and 3.32±0.58, 1.23±0.46, 3.55±1.82 and 45.54±21.38 respectively in severe OSA. There was a statistically significant difference between mild moderate and severe OSA regarding thyroid profile as well as BMI with p of <0.05. CONCLUSION: The prevalence of hypothyroidism was common among patients with OSA and the severity of OSA correlated with thyroid function tests and BMI.


Subject(s)
Hypothyroidism , Sleep Apnea, Obstructive , Adult , Body Mass Index , Humans , Hypothyroidism/complications , Hypothyroidism/epidemiology , Middle Aged , Obesity/complications , Obesity/epidemiology , Sleep Apnea, Obstructive/complications , Sleep Apnea, Obstructive/diagnosis , Sleep Apnea, Obstructive/epidemiology , Thyrotropin
8.
J Phys Chem B ; 126(6): 1284-1300, 2022 Feb 17.
Article in English | MEDLINE | ID: mdl-35120291

ABSTRACT

To fulfill the increasing demand for drinking water, researchers are currently exploring nanoporous two-dimensional materials, such as hexagonal boron nitride (hBN), as potential desalination membranes. A prominent, yet unsolved challenge is to understand how such membranes will perform in the presence of defects or surface charge in the membrane material. In this work, we study the effect of grain boundaries (GBs) and interfacial electrostatic interactions on the desalination performance of bicrystalline nanoporous hBN using classical molecular dynamics simulations supported by quantum-mechanical density functional theory (DFT) calculations. We investigate three different nanoporous bicrystalline hBN configurations, with symmetric tilt GBs having misorientation angles of 13.2, 21.8, and 32.2°. Using lattice dynamics calculations, we find that grain boundaries alter the areas and shapes of nanopores in bicrystalline hBN, as compared to the nanopores in monocrystalline hBN. We observe that, although bicrystalline nanoporous hBN with a misorientation angle of 13.2° shows an improved water flow rate by ∼30%, it demonstrates reduced Na+ ion rejection by ∼6%, as compared to monocrystalline hBN. We also uncover the role of the nanopore shape in water desalination, finding that more elongated pores with smaller sizes (in 21.8- and 32.2°-misoriented bicrystalline hBN) can match water permeation through less elongated pores of slightly larger sizes, with a concomitant ∼3-4% decrease in Na+ rejection. Simulations also predict that the water flow rate is significantly affected by interfacial electrostatic interactions. Indeed, the water flow rate is the highest when altered partial charges on B and N atoms were determined using DFT calculations, as compared to when no partial charges or bulk partial charges (i.e., charged hBN) were considered. Overall, our work on water/ion transport through nanopores in bicrystalline hBN indicates that the presence of GBs and surface charge can lead, respectively, to a decrease in the ion rejection and water permeation performance of hBN membranes.

9.
Sensors (Basel) ; 22(1)2022 Jan 04.
Article in English | MEDLINE | ID: mdl-35009896

ABSTRACT

Trilateration-based target localization using received signal strength (RSS) in a wireless sensor network (WSN) generally yields inaccurate location estimates due to high fluctuations in RSS measurements in indoor environments. Improving the localization accuracy in RSS-based systems has long been the focus of a substantial amount of research. This paper proposes two range-free algorithms based on RSS measurements, namely support vector regression (SVR) and SVR + Kalman filter (KF). Unlike trilateration, the proposed SVR-based localization scheme can directly estimate target locations using field measurements without relying on the computation of distances. Unlike other state-of-the-art localization and tracking (L&T) schemes such as the generalized regression neural network (GRNN), SVR localization architecture needs only three RSS measurements to locate a mobile target. Furthermore, the SVR based localization scheme was fused with a KF in order to gain further refinement in target location estimates. Rigorous simulations were carried out to test the localization efficacy of the proposed algorithms for noisy radio frequency (RF) channels and a dynamic target motion model. Benefiting from the good generalization ability of SVR, simulation results showed that the presented SVR-based localization algorithms demonstrate superior performance compared to trilateration- and GRNN-based localization schemes in terms of indoor localization performance.


Subject(s)
Algorithms , Neural Networks, Computer , Computer Simulation , Motion , Radio Waves
10.
Indian J Otolaryngol Head Neck Surg ; 74(Suppl 2): 3469-3472, 2022 Oct.
Article in English | MEDLINE | ID: mdl-34631494

ABSTRACT

Coronavirus disease 2019 (COVID-19) has been found to be associated with mucormycosis in few parts of the world, especially India. It is important to look for reasons for this upsurge of cases so that other countries may take proper steps to prevent it. A prospective clinico-demographic study was conducted in SMS Medical College, Jaipur, India from April to May 2021. All patients (235) with COVID associated mucormycosis (CAM) were studied in detail with reference to their diabetic status and steroid intake during treatment of COVID-19. Steroid usage was in 84.3% of patients with methylprednisolone being the most commonly used steroid (66.8%). Majority of the patients had taken steroids for 7-14 days. Diabetes was found in 204 patients and 42.1% of patients were newly diagnosed during/after COVID-19 treatment. The HbA1c levels of diabetic patients ranged from 6.0% to 16.3%. This is perhaps the biggest study in the world shows that the triad of COVID-19, diabetes and steroid usage is a major contributing factor towards mucormycosis. Proper steps should be taken to prevent CAM.

11.
Lung India ; 38(1): 5-11, 2021.
Article in English | MEDLINE | ID: mdl-33402631

ABSTRACT

BACKGROUND: Predictors of survival for interstitial lung disease (ILD) in the Indian population have not been studied. The primary objective of the study was to assess the Modified-Gender Age and Physiology (M-GAP) score to predict survival in patients with ILD seen in clinical practice. We also analyzed the role of demographic and radiological characteristics in predicting the survival of patients with ILD. MATERIALS AND METHODS: In the ILD India registry, data were collected from 27 centers across 19 cities in India between March 2012 and June 2015. A single follow-up was conducted at 18 centers who agreed to participate in the follow-up in 2017. M-GAP score (range 0-5) was calculated with the following variables: age (≤60 years 0, 61-65 years 1, and >65 years 2), gender (female 0, male 1), and forced vital capacity% (>75% 0, 50%-75% 1, and >75% 2). A score of 0-3 and score of 4 and 5 were classified into Stage 1 and 2, respectively. Other predictors of survival, such as the history of tuberculosis, smoking, and the presence of honeycombing on computed tomography scan, were also evaluated. RESULTS: Nine hundred and seven patients were contacted in 2017. Among them, 309 patients were lost to follow-up; 399 were alive and 199 had died. M-GAP was significantly associated with survival. Similarly, other predictors of survival were ability to perform spirometry (hazard ratio [HR]: 0.49, 95% confidence interval [CI]: 0.34-0.72), past history of tuberculosis (HR: 1.57, 95% CI: 1.07-2.29), current or past history of smoking (HR: 1.51, 95% CI: 1.06-2.16), honeycombing (HR: 1.81, 95% CI: 1.29-2.55), a diagnosis of connective tissue disease -ILD (HR: 0.41, 95% CI: 0.22-0.76), and sarcoidosis (HR: 0.24, 95% CI: 0.08-0.77). CONCLUSION: In a subgroup of patients with newly diagnosed ILD enrolled in ILD India registry and who were available for follow-up, M-GAP score predicted survival. Honeycombing at the time of diagnosis, along with accurate history of smoking, and previous history of tuberculosis were useful indices for predicting survival.

12.
World J Clin Cases ; 9(36): 11338-11345, 2021 Dec 26.
Article in English | MEDLINE | ID: mdl-35071564

ABSTRACT

BACKGROUND: Coronavirus disease 2019 (COVID-19) patients who suffer severe infection or comorbidities have an increased risk of developing fungal infections. There is a possibility that such infections are missed or misdiagnosed, in which case patients may suffer higher morbidity and mortality. COVID-19 infection, aggressive management strategies and comorbidities like diabetes render patients prone to opportunistic fungal infections. Mucormycosis is one of the opportunistic fungal infections that may affect treated COVID patients. CASE SUMMARY: We present a case series of four adult males who were diagnosed with mucormycosis post-COVID-19 recovery. All the patients had diabetes and a history of systemic corticosteroids for treatment of COVID-19. The mean duration between diagnosis of COVID-19 and development of symptoms of mucor was 15.5 ± 14.5 (7-30) d. All patients underwent debridement and were started on antifungal therapy. One patient was referred to a higher center for further management, but the others responded well to treatment and showed signs of improvement at the last follow-up. CONCLUSION: Early diagnosis and management of mucormycosis with appropriate and aggressive antifungals and surgical debridement can improve survival.

13.
Phys Chem Chem Phys ; 22(36): 20453-20465, 2020 Sep 23.
Article in English | MEDLINE | ID: mdl-32926026

ABSTRACT

Due to superior water permeability, structural stability, and adsorption capability, h-BN nanosheets are emerging as an efficient membrane for water desalination. In order to cater to the demand for potable water, large size membranes are required to maintain a high desalination rate from water purification systems. These large size membranes usually contain polycrystals with an offset in their mechanical properties from pristine h-BN nanosheets. In this article, molecular dynamics based simulations were performed in conjunction with a hybrid interatomic potential (reactive force field, TIP3P, and Lennard Jones) to simulate the mechanical strength of nanoporous single and bicrystalline h-BN nanosheets under water submerged conditions. The interaction between the atomic configuration of grain boundary atoms and nanopores in the presence of water molecules helps in investigating the viability of defective h-BN nanomembranes for underwater applications. Higher dislocation density enhances the mechanical strength of nanoporous bicrystalline h-BN nanosheets containing twin nanopores, which makes them a better substitute for water submerged applications as compared to the pristine nanosheets. The mechanical strength of nanoporous single crystalline h-BN nanosheets deteriorates with an increase in the number of nanopores, whereas a contrasting trend was observed with bicrystalline h-BN nanosheets.

14.
Lung India ; 37(4): 359-378, 2020.
Article in English | MEDLINE | ID: mdl-32643655

ABSTRACT

BACKGROUND: Interstitial lung disease (ILD) is a complex and heterogeneous group of acute and chronic lung diseases of several known and unknown causes. While clinical practice guidelines (CPG) for idiopathic pulmonary fibrosis (IPF) have been recently updated, CPG for ILD other than IPF are needed. METHODS: A working group of multidisciplinary clinicians familiar with clinical management of ILD (pulmonologists, radiologist, pathologist, and rheumatologist) and three epidemiologists selected by the leaderships of Indian Chest Society and National College of Chest Physicians, India, posed questions to address the clinically relevant situation. A systematic search was performed on PubMed, Embase, and Cochrane databases. A modified GRADE approach was used to grade the evidence. The working group discussed the evidence and reached a consensus of opinions for each question following face-to-face discussions. RESULTS: Statements have been made for each specific question and the grade of evidence has been provided after performing a systematic review of literature. For most of the questions addressed, the available evidence was insufficient and of low to very low quality. The consensus of the opinions of the working group has been presented as statements for the questions and not as an evidence-based CPG for the management of ILD. CONCLUSION: This document provides the guidelines made by consensus of opinions among experts following discussion of systematic review of evidence pertaining to the specific questions for management of ILD other than IPF. It is hoped that this document will help the clinician understand the accumulated evidence and help better management of idiopathic and nonidiopathic interstitial pneumonias.

15.
Lung India ; 37(4): [359-378], July 1, 2020.
Article in English | BIGG - GRADE guidelines | ID: biblio-1117197

ABSTRACT

Interstitial lung disease (ILD) is a complex and heterogeneous group of acute and chronic lung diseases of several known and unknown causes. While clinical practice guidelines (CPG) for idiopathic pulmonary fibrosis (IPF) have been recently updated, CPG for ILD other than IPF are needed. Methods: A working group of multidisciplinary clinicians familiar with clinical management of ILD (pulmonologists, radiologist, pathologist, and rheumatologist) and three epidemiologists selected by the leaderships of Indian Chest Society and National College of Chest Physicians, India, posed questions to address the clinically relevant situation. A systematic search was performed on PubMed, Embase, and Cochrane databases. A modified GRADE approach was used to grade the evidence. The working group discussed the evidence and reached a consensus of opinions for each question following face-to-face discussions. Results: Statements have been made for each specific question and the grade of evidence has been provided after performing a systematic review of literature. For most of the questions addressed, the available evidence was insufficient and of low to very low quality. The consensus of the opinions of the working group has been presented as statements for the questions and not as an evidence-based CPG for the management of ILD. Conclusion: This document provides the guidelines made by consensus of opinions among experts following discussion of systematic review of evidence pertaining to the specific questions for management of ILD other than IPF. It is hoped that this document will help the clinician understand the accumulated evidence and help better management of idiopathic and nonidiopathic interstitial pneumonias.


Subject(s)
Humans , Lung Diseases, Interstitial/diagnosis , Lung Diseases, Interstitial/prevention & control , Lung Diseases, Interstitial/therapy , Idiopathic Pulmonary Fibrosis/complications , Idiopathic Pulmonary Fibrosis/prevention & control
16.
Lung India ; 37(3): 268-271, 2020.
Article in English | MEDLINE | ID: mdl-32367852

ABSTRACT

COVID-19 has emerged as one of the most significant illnesses of the current century. It is caused by severe acute respiratory syndrome coronavirus 2. The world was initially viewing it as a localized outbreak in Wuhan city of China; however, it started spreading quickly to other parts of the world. Globally, half-hearted containment measures and a false sense of safety against this novel coronavirus led to the dissemination of disease. Currently, no effective therapy or vaccine is available to manage this illness. After learning a huge lesson, global efforts would hopefully lead to effective control of this pandemic.

17.
Lung India ; 37(2): 100-106, 2020.
Article in English | MEDLINE | ID: mdl-32108592

ABSTRACT

BACKGROUND: Respiratory disorders are important contributors to disease burden across the world. The aim is to assess the proportionate burden of types of respiratory diseases and their seasonal patterns in India we are performing a field study. The present report describes methodological aspects of a respiratory disease point prevalence survey from India. METHODS: A total of 4108 chest physicians were invited. Acceptance was received from 420 sites. Chest physicians were classified according to location of practice one as medical college, district government hospital, private hospital, and private clinics. Qualifications of practicing chest physicians were postgraduate in chest medicine, including Doctorate of Medicine (68.4%), diploma in chest medicine (22.1%), and Postgraduate in Medicine (9.5%). The study questionnaire was designed to record demographic data, comorbidities, risk factors, and respiratory conditions based on ICD-10. RESULTS: A total of 366 sites provided baseline data, and the response rate of recruitment of the study sites was 8.9% in the baseline phase. However, government and private medical colleges, as well as government and private hospitals across India, were part of recruitment of respiratory patients for this survey. CONCLUSIONS: It is feasible to conduct a large multisite study to assess respiratory disease burden. Challenges include low response rate and logistic issues.

18.
19.
Phys Chem Chem Phys ; 21(24): 13116-13125, 2019 Jun 28.
Article in English | MEDLINE | ID: mdl-31169285

ABSTRACT

The aim of this research article was to investigate the effect of grain boundaries (GBs), and hydrogen functionalisation on the fracture toughness of bi-crystalline hexagonal boron nitride (h-BN) nanosheets. Molecular dynamics based simulations were performed in conjunction with the reactive force field to study the crack tip behaviour in single and bi-crystalline h-BN nanosheets. Atomistic simulations help in predicting a positive effect of the GB plane in the near vicinity of the crack tip. The density of 5|7 dislocation pairs significantly affects the fracture behaviour of bi-crystalline h-BN nanosheets. Additionally, the distance of the GB plane from the crack tip, and limited hydrogen functionalisation of GB atoms, further help in improving the fracture toughness of bi-crystalline h-BN nanosheets. Hydrogen functionalisation helps in inducing out of plane displacement at the GB plane, which helps in arresting or retarding the crack propagation. It can be concluded from the results that instead of deteriorating, geometrical defects such as GBs can also be used to tailor the fracture toughness of h-BN nanosheets. This study on the fracture toughness of bi-crystalline h-BN nanosheets helps in complementing the research on using porous h-BN nanosheets as nanomembranes for water desalination and ion separation.

20.
Lung India ; 36(Supplement): S91, 2019 Nov.
Article in English | MEDLINE | ID: mdl-31939349
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