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Global environmental concerns over increased emissions from the transportation vehicles have driven research instincts towards development of clean energy vehicles. Pure and hybrid electric vehicles coupled with lithium-ion batteries for energy storage are environmental friendly options to realize the future dream of low carbon emissions. However, an efficient battery thermal management system (BTMS) is a prerequisite for safe operation of such high voltage batteries to avoid thermal runaway and degradation, thereby maintaining the temperature uniformity in the battery pack. Thus, the present work numerically investigates the performance of an air cooled battery module for efficient removal of heat generated during the discharge process at different values of air-flow velocity, cell configuration and the number of cells in the battery module. A coupled electrochemical-thermal model is employed to model the discharge behaviour of the battery in conjunction with the two-dimensional flow and heat transfer model to monitor the temperature in and out of each battery cell. A correlation is developed for the maximum temperature in the module as a function of the number of cells in the system. The flow configuration (inline or staggered arrangement) of cells in the stack is observed to have no influence over the velocity and thermal field beyond a critical value of number of cells in the module.

Introduction: Medical education increases mental stress and affects the quality of life in medical students. Tough competition, academic performances, psychological distress, and unhealthy lifestyle add extra burden to the student. The study aimed to compare the quality of life among students of first and final year students. Materials and Methods: This was a cross-sectional study among first and final-year students of Bachelor in Medicine and Bachelor in Surgery (MBBS) degree at National Medical College at Birgunj, Nepal. Pre-designed socio-demographic proforma along with the Kuppuswamy scale was administered to the student. Another scale used was the English version of (World Health Organization Quality of Life-Brief version) WHOQoL-Bref scale. Result: Eighty-one students participated in this study, where 54 students were from the first year and 27 students from an internship. 43.2% of them belonged to the upper socioeconomic class as per the Kuppuswamy scale. The quality of life of interns was higher and better in all domains but was statistically significant in general (0.002), psychological (0.006), environmental (0.002), and overall (0.008) domains. Conclusion: The quality of life of medical students is lower than the general population. It is poorer for the first-year student than the final year interns.

Introduction Varying public views on cannabis use across countries may explain the variation in the prevalence of use, policies, and research in individual countries, and global regulation of cannabis. This paper aims to describe the current state of cannabis use, policies, and research across sixteen countries. Methods PubMed and Google Scholar were searched for studies published from 2010 to 2020. Searches were conducted using the relevant country of interest as a search term (e.g., “Iran”), as well as relevant predefined keywords such as “cannabis,” “marijuana,” “hashish,” “bhang “dual diagnosis,” “use,” “addiction,” “prevalence,” “co-morbidity,” “substance use disorder,” “legalization” or “policy” (in English and non-English languages). These keywords were used in multiple combinations to create the search string for studies’ titles and abstracts. Official websites of respective governments and international organizations were also searched in English and non-English languages (using countries national languages) to identify the current state of cannabis use, policies, and research in each of those countries. Results The main findings were inconsistent and heterogeneous reporting of cannabis use, variation in policies (e.g., legalization), and variation in intervention strategies across the countries reviewed. European countries dominate the cannabis research output indexed on PubMed, in contrast to Asian countries (Thailand, Malaysia, India, Iran, and Nepal). Conclusions Although global cannabis regulation is ongoing, the existing heterogeneities across countries in terms of policies and epidemiology can increase the burden of cannabis use disorders disproportionately and unpredictably. There is an urgent need to develop global strategies to address these cross-country barriers to improve early detection, prevention, and interventions for cannabis use and related disorders.

An intermittent supply of energy from renewable or unconventional resources has resulted in the use of phase change materials (PCM) in thermal energy storage (TES) systems. In this work, melting and heat transfer characteristics in a rectangular enclosure of different aspect ratios (width to height) filled with a phase change material (PCM) have been studied numerically. The n-octadecane has been selected as the PCM (melting temp = 301.35 K, Prandtl number ∼ 60). We considered five different aspect ratios (AR) of the enclosure to delineate the effects of 9-fold variation in the aspect ratio. The simulations were carried out using ANSYS Fluent 19.2. In particular, extensive results have been presented and discussed in terms of the temperature contours, rate of melting and energy storage, and total time required to reach the fully melt condition. Additionally, the effect of the mushy zone parameter (A mush ) on the melting performance has also been investigated. Low values of the A mush were seen to predict the higher rate of melting. At a fixed value of A mush , ∼ 3 times faster melting rate was observed as the value of AR was reduced from 3 to 1/3. Finally, it can be concluded that melting and energy storage rate largely depends on the aspect ratio of the enclosure and the optimal choice of the value of the A mush .

The history of psychiatry as a discipline in Nepal has been poorly studied. We have attempted to summarise historical landmarks to explore how it began and its evolution over time in relation to contemporary political events. Although Nepal has achieved several milestones, from establishing a psychiatric out-patient department with one psychiatrist in 1961 to having more than 500 psychiatric in-patient beds with 200 psychiatrists by 2020, the pace, commitment and dedication seem to be slower than necessary: the current national mental health policy dates back to 1996 and has not been updated since; there is no Mental Health Act; the number of psychiatric nurses and in-patient psychiatric beds has increased only slowly; and there is a dearth of professional supervision in rehabilitation centres. Thus, despite making significant progress, much more is required, at greater intensity and speed, and with wide collaboration and political commitment in order to improve the mental health of all Nepali citizens, including those living in rural areas and or in deprived conditions.

Forced convection heat transfer in power-law fluids has been investigated numerically around four identical circular cylinders in a diamond array in a square enclosure. For the laminar flow, the go...

Stepwise synthesis of aminotetrazole functionalized MgO–SiO2 (MSNT) nanocomposites has been achieved by a simple wet chemical method. The as-synthesized nanomaterial is investigated for the removal...

Introduction: Nepal entered into a lockdown mode since 24th March 2020 to control the spread of COVID-19 infection. Our aim was to evaluate the mental and behavioural impact of lockdown due to COVID-19 pandemic on the general public of Nepal in terms of the point prevalence of sadness, anxiety, feelings and relationship issues due to lockdown. Material And Method: It was a web-based cross-sectional survey conducted by using the Survey Monkey platform during 8th April 2020 and 29th April 2020. The link generated was circulated on Whatsapp platforms. Self-designed clinical profile was made to assess different feelings, leisure activities and relationship changes with family members that are not assessed using scale. The survey link was circulated starting from 8th April 2020 and was closed on 29th April 2020. Results: Of the 142 participants about 35.9% reported being sad, 28.2% had anxiety and about 46.5% of the participants felt lonely. Fear of death (60.6%) and getting infected with corona (52.1%) were the most common stress. Most of them were involved in sexual activities (67.6%) and reading books (42.3%) during lockdown. Some (14.8% and 18.3%) reported marked improvement in relationships with parents and children respectively. Conclusion: The present survey suggests that substantial proportion of the population do not report change in relationship despite reporting sadness, loneliness and change in daily activities. Therefore, social relationship and brotherhood need to be advised in addition to minimising emotional distancing during awareness programs related to COVID-19.

The epidemiological surveillance of canine reproductive disorders was carried out based on total 21852 clinical cases (9159 at the College Clinic, Anand, and 12693 at Polyclinic, Vadodara) attended in dogs over three years. Among them, the overall 486 (2.22 %) and 85 (0.39 %) cases were of gynecological and andrological nature, respectively. Amongst the gynaecological cases, the highest incidence was of pyometra (23.25 %), followed in descending order by mammary tumours (22.22 %), pregnancy diagnosis (16.25 %), elective sterilization (9.88 %), CTVG (7.61 %), proestrus bleeding (5.97 %), pseudo-pregnancy (3.06 %), misalliance (2.67 %), anestrus (2.26 %), dystocia (1.65 %), abortion (1.03 %) and Cesarean (0.82%). Among the andrological cases, the highest cases were of venereal granulomas (31.76 %) followed in descending order by scrotal dermatitis (18.82 %), castration (12.94 %), orchitis (7.06 %), cryptorchidism, paraphimosis and balanoposthitis (5.88 % each), prostatic hyperplasia and testicular tumor (4.70 % each) and testicular hyperplasia (2.35 %). The breed most prone to gynecological disorders was non-descript (51.65 %), Pomeranian (16.25 %), German Shepherd, Labrador (6.79 % each) and Doberman (5.97 %). Maximum cases were in the young age group of 0-5 years (51.02 %), followed by the middle age group of 6-10 years (27.57 %) and older bitches of 11-15 years of age (20.58 %). The major clinical modalities and their management strategies adopted have also been summarized. The results signified the importance of life-threatening diseases like pyometra, mammary tumors, and CTVG in pet dogs in urban areas of middle Gujarat.

In this study, we report the deposition of a thin layer of Cd(OH)₂ over δ-MnO₂ deposited on a fluorine-doped tin oxide (FTO) glass substrate, thereby forming a heterojunction with synergistic effects. Electrodes fabricated by a room-temperature, facile, and cost-effective chemical bath deposition method display enhanced photoactivity when used as cathodes for the hydrogen evolution reaction (HER) in a photoelectrochemical cell, with an observed photocurrent of 0.3 mA/cm² at 0 V vs reversible hydrogen electrode (RHE). The electrodes also showcase a dark electrocatalytic current of 2.9 mA/cm² without illumination. The δ-MnO₂/Cd(OH)₂ nano-heterostructure is analyzed thoroughly via various physicochemical, optical and electrochemical methods to understand the phenomena involved in the conduction characteristics. The enhanced photoconductivity is attributed to effective charge separation and transport by the presence of synergistic materials with optimal band gap energies. These results show promise for the use of birnessite-based materials as sustainable electro- or photocatalysts for the hydrogen evolution reaction.

Background Schizophrenia is one of the worst diseases with its ubiquitous challenges due to its unique psychopathology and life events. Patients with schizophrenia use various coping strategies to overcome distress. The aim of the study was to evaluate the association between perceived stress, quality of life, and coping skills in patients with schizophrenia in remission. A total of 48 consecutive patients of schizophrenia, in remission, attending outpatient department of psychiatry at Academic hospital, South India, who satisfied the inclusion and exclusion criteria were recruited for the present study. The participants were assessed on Positive and Negative Symptoms Scale, Ways of Coping Checklist – Revised and Perceived Stress Scale and WHO Quality of Life. Results were analyzed using appropriate statistical package software v 16.0. Result Highest medial was found in self-controlling and positive reappraisal coping skills. Distancing is associated with high physical domain of quality of life whereas patients with good social support score more in social and physical domain of quality of life. Conclusion Patients with history of schizophrenia even though in remission dwell a stressful life. They often need different kind of social support or cognitive aids. In that view, studying their stress level, ability to cope with it, and quality of life will help us to manage them in better way.

A porous, Cu(II)-metal organic framework (Cu-MOF) constituted of a rigid lactam functionalized ditopic ligand (H2L) was synthesized at room temperature under slow evaporation conditions {H2L = (5-(1-oxo-2,3-dihydro-1H-inden-2-yl)isophthalic acid)}. The single crystal X-ray structure revealed the formation of a 3D framework of Cu-MOF with one-dimensional (1D) channels decorated with lactam groups and exposed metal centers in the crystallographic c-axis. Interestingly, Cu(II) coordinated DMF molecules were eliminated from the Cu(II) metal center on activation of Cu-MOF at a temperature of 150 °C under high vacuum to generate a solvent free framework with pores lined with unsaturated Lewis acidic Cu(II) ions, i.e., Cu-MOF'. The lactam functionalized channels inclined toward the CO2, which interact with the Cu(II) metal sites lined in the channels of Cu-MOF' and exhibit fascinating solvent-free heterogeneous catalytic conversion of CO2 to cyclic carbonates at atmospheric pressure of CO2, under mild conditions. Furthermore, the Cu-MOF' catalyst was easily recycled and reused for several cycles without a significant loss in catalytic activity.

Liver diseases occurring during pregnancy can be serious and can progress rapidly, affecting outcomes for both the mother and fetus. They are a common cause of concern to an obstetrician and an important reason for referral to a hepatologist, gastroenterologist, or physician. Liver diseases during pregnancy can be divided into disorders unique to pregnancy, those coincidental with pregnancy, and preexisting liver diseases exacerbated by pregnancy. A rapid differential diagnosis between liver diseases related or unrelated to pregnancy is required so that specialist and urgent management of these conditions can be carried out. Specific Indian guidelines for the management of these patients are lacking. The Indian National Association for the Study of the Liver (INASL) in association with the Federation of Obstetric and Gynaecological Societies of India (FOGSI) had set up a taskforce for development of consensus guidelines for management of patients with liver diseases during pregnancy, relevant to India. For development of these guidelines, a two-day roundtable meeting was held on 26-27 May 2018 in New Delhi, to discuss, debate, and finalize the consensus statements. Only those statements that were unanimously approved by most members of the taskforce were accepted. The primary objective of this review is to present the consensus statements approved jointly by the INASL and FOGSI for diagnosing and managing pregnant women with liver diseases. This article provides an overview of liver diseases occurring in pregnancy, an update on the key mechanisms involved in its pathogenesis, and the recommended treatment options.

Particle grouping that arises from temporal and spatial variation of air flow is a promising method to facilitate agglomeration and removal of aerosol. We conduct a computational investigation on this phenomenon under an oscillatory flow in a wavy duct using a discrete phase method. This setup is simple and practically feasible. The grouping behavior is affected by the flow Reynolds number, duct wavelength, angular frequency of oscillation, ratio of minimum to maximum duct diameter and velocity ratio. Three different regimes are identified: no grouping, stable/strong grouping and unstable/weak grouping. It is found that a moderate delay of flow response to the imposed pulsations is critical for grouping. Among the investigated values for the periodicity parameters, the strongest grouping takes place when the duct wavelength is four times the maximum duct diameter, and the angular frequency of oscillation is five times the reciprocal of characteristic flow time. Moreover, an increase in the velocity ratio and a decrease in the diameter ratio further enhance the grouping behavior under otherwise identical conditions. Due to the flow complexity in this realistic setup, the criterion for particle grouping is different from that based on an ideal 1D standing wave flow field in the literature.

The structural diversity of Co(II) metal centers is known to influence their physicochemical properties. A novel two-dimensional (2D) Co(II)-MOF {[Co5(HL)4(dpp)2(H2O)2(μ-OH)2]·21H2O} n has been designed and synthesized by adopting a mixed-ligand strategy, using 1,3-di(4-pyridyl)propane (dpp) colinker with a flexible spacer H3L (H3L: 5-(2 carboxybenzyloxy)isophthalic acid). Co(II)-MOF features a 2D network, which is further interpenetrated among the equivalent sets and therefore results in a 3D supramolecular network. Topologically, the entire network can be viewed as a (3,4,8)-connected three-nodal net with the extended point symbol of {4.5.7}4{412.52.710.94}{52.8.92.10}2, duly assigned to the novel topological type smm2. The functional utility of Co(II)-MOF is demonstrated by employing it toward oxygen evolution reaction (OER) in a photoelectrochemical cell, exhibiting appreciable photocurrents of up to 5.89 mA/cm2 when used as an anode in a photoelectrochemical cell, while also displaying encouraging electrocatalytic currents of 9.32 mA/cm2 (at 2.01 V vs RHE) for the OER. Moreover, detailed electrochemical impedance spectroscopy studies confirm enhanced charge-transfer kinetics and improved conductivity under illumination with minimal effect of interfacial phenomena. This work provides a reference for the expanding field of research into applications of MOF materials and establishes MOF materials as favorable candidates for sustainable and efficient design of electrodes for water splitting.

A two-dimensional, tetragonal porous metal organic framework {[Zn2(TBIB)2(HTCPB)2]·9DMF·19H2O}n (1) has been synthesized under hydrothermal conditions by employing 1,3,5-tri(1H-benzo[d]imidazol-1-y...

Laminar natural convection heat transfer in a power-law fluid from an isothermal rotating cylinder placed coaxially in a square duct has been studied numerically over the following ranges of conditions: Grashof number ( 10 ⩽ Gr ⩽ 10 3 ) ; Prandtl number ( 0.72 ⩽ Pr ⩽ 100 ) ; power-law index ( 0.2 ⩽ n ⩽ 1.5 ) and non-dimensional rotational velocity ( 0 ⩽ S ⩽ 4 ) . The spatial variation of the velocity and temperature fields are visualised in terms of the streamline and isotherm patterns, and temperature and vertical velocity at a few locations, respectively. Indeed, a range of flow patterns including twin-celled and single-celled recirculating regions can be observed depending upon the relative strengths of the buoyancy-induced and forced flow. The rate of heat transfer is described in terms of the distribution of the local Nusselt number over the surface of the cylinder together with its surface averaged value. As expected, the mean Nusselt number shows a positive dependence on the both Grashof and Prandtl numbers irrespective of the values of the power-law index and rotational velocity. For a non-rotating cylinder (S = 0), shear-thinning fluid behaviour promotes heat transfer, whereas shear-thickening viscosity impedes it with reference to that in Newtonian fluids otherwise under identical conditions. For the case of a rotating cylinder ( S ≠ 0 ), the rotation has positive influence on the rate of heat transfer at low values of the Grashof or Rayleigh number ( Ra 500 ) irrespective of the type of fluid behaviour, i.e., shear-thinning or shear-thickening or Newtonian. However, at high values of the Grashof or Rayleigh numbers, the gradual increase of rotation of the cylinder first lowers the rate of heat transfer, and then increases it for shear-thickening (n > 1) and Newtonian fluids (n = 1). On the other hand, a reverse trend is seen for shear-thinning fluids. These non-monotonous trends in the overall heat transfer stem from the interactions between the rate of variation of the fluid viscosity and the temperature gradient on the surface of the cylinder. Therefore, a prudent choice of the operating conditions and the fluid behaviour can be used to regulate the rate of heating or cooling from a rotating cylinder. Finally, the present values of the average Nusselt number are correlated in order to facilitate the interpolation of the present results for the intermediate values of Gr, Pr, S and n and/or the estimation of heat transfer duty in a new application.

Experimental measurement of intense light induced refractive index is demonstrated using Fizeau interferometer. Refractive index is induced in a specific region of the sample with intense light pulse of a linearly polarized, Q- switched Nd:YAG laser at 1064nm wavelength. The respective change in optical path difference (OPD) is measured using Fizeau interferometer. The OPD so obtained is mapped in terms of change in refractive index in the area of interaction of pump beam and sample. The measured induced refractive index is then used to calculate thermo-optic coefficient of the ZnPc embedded polymeric sample.

Introduction This study aims to review recent scientific publications and research output in the field of psychiatry, from a series of countries in the Asia-Pacific region (Australia, India, Indonesia, Iran, Lebanon, Malaysia, and Nepal), with a view to identify themes and similarities across regions, as well as to examine the barriers and challenges in mental health research faced by countries in the region. Methods Seven psychiatrists from seven countries reviewed recent published and ongoing research in psychiatry in their respective nations, with respect to themes, as well as any barriers or challenges faced by mental health researchers. Results While the seven nations included in this review vary in terms of research capabilities and economic development level, they share many similarities both in terms of research direction, and with regards to challenges faced. Limitations in the form of sociocultural differences from the West, and a lack of funding were some of the barriers identified. Discussion Mental health research in the region has been progressing well. However, more varied research in the form of qualitative or economic studies are lacking, as are multi-center studies. The similar issues that nations face with regards to research could perhaps benefit from collaborative efforts and initiatives for the furtherance of research in the region.

Due to increasing energy demand caused by growing civilization and human comfort on one hand, and the limited presence of conventional energy resources such as fossil fuels on the other hand, the use of phase change materials (PCM) in thermal energy storage (TES) systems has significantly increased. Typical applications are in building walls, glass windows, heat and cold storage units, textiles, cooling helmets, batteries, solar water heating system, HVAC units, etc. These materials store and release a bulk amount of latent heat during phase change process. Moreover, such materials are more economical and eco-friendly in use. However, the design and optimization of a system utilizing PCM is challenging. The objective of this work is to design and investigate a system yielding high rate of heat transfer to ensure lesser melting time required to achieve thermostat condition. In this work, the effect of asymmetric positioning of a heated circular cylinder on melt fraction, energy storage and temperature profiles is studied numerically for the Lauric acid as PCM (melting temp ~ 319K, Rayleigh number ~ 20,000, Prandtl number ~ 140) confined in a square duct. The simulations have been carried out using ANSYS Fluent 19.2. We considered five different positions/locations of the cylindrical object. It is found that a simple modulation in the location of the heated object, it is possible to tune the rate of heat transfer and thus the performance of TES devices.

This work reports results on the drag and heat transfer from an in-line array of three isothermal spheres falling in a cylindrical confinement filled with Bingham plastic fluids. The effects of dim...

A systematic numerical investigation on heat transfer from a heated sphere settling in aqueous nanofluids has been carried out to elucidate the effect of confinement and the other pertinent dimensionless numbers on heat transfer. In this work, four types of nanoparticles (NPs) have been considered, namely, Al2O3, CuO, SiO2 and ZnO, each of two different diameters of dnp = 20 nm and 80 nm. In order to account for the variation of properties with temperature, the temperature-dependent equations for the viscosity and thermal conductivity of nanofluids are employed here. Extensive results on streamline and isotherm contours, wake characteristics (length), drag coefficient and local and average Nusselt Number have been obtained and discussed to elucidate the effect of Peclet number (Pe), nanoparticle volume fraction (ϕ) and blockage ratio (λ) over the following ranges of conditions: 5 ≤ Pe ≤ 600, 0 ≤ ϕ ≤ 0.05 and 0.1 ≤ λ ≤ 0.9 where λ is the sphere-to-tube diameter ratio. Overall, the recirculation length shows a positive dependence on both Peclet number (Pe) and particle size (dnp) while it exhibits inverse trends with respect to ϕ and λ. A significant enhancement (20–30%) in the rate of heat transfer over the conventional Newtonian fluids is observed and it is seen to increase with the increasing values of the Peclet number. Finally, a simple predictive correlation for the average Nusselt number is developed which includes the conduction limit and, it enables the estimation of the Nusselt number for the intermediate values of the parameters reported in a new application.

In this work, the effects of tilt angle and fluid yield stress on the laminar natural convection from an isothermal square bar cylinder in a Bingham plastic fluid confined in a square duct has been investigated over the following ranges of conditions: Rayleigh number, 102 ≤ Ra ≤ 105; Prandtl number, 10 ≤ Pr ≤ 100; Bingham number, 0 ≤ Bn ≤ 100; aspect ratio, 0.125 ≤ B ≤ 0.5 and angle of inclination, 0° ≤ λ ≤ 45°. Extensive results on the detailed flow and temperature fields are discussed in terms of the streamline and isotherm contours, yield surfaces, local and average Nusselt numbers as functions of the aforementioned parameters. All else being equal, the Rayleigh number promotes yielding of fluid (enhances convection) whereas the Bingham number counters this tendency. For given values of Ra, Pr, λ and B, there exists a limiting Bingham number (Bnmax ) at which the entire body of fluid is frozen so to say and heat transfer occurs solely by conduction and this limiting value of the average Nusselt number is only a function of the geometry of the system, i.e., the values of B and λ. Also, the rate of heat transfer increases with the increasing angle of inclination while a negligible effect is observed for high Bingham number values due to the strong influence of conduction. However, for the intermediate values of Bingham number (0

AimsElectroconvulsive Therapy (ECT) is an important modality of treatment for treatment resistant psychiatric disorders. Young medical students like general public might harbor several misconceptions about ECT. In this pilot survey, we explored the knowledge and attitude about ECT amongst young medical students training in a medical college affiliated to a teaching hospital in Southern Nepal.MethodA 23-item questionnaire in English language with either ‘True’ or ‘False’ response as outcome was developed by reviewing findings from previous studies. Brief information was also taken to record familiarity of medical students with ECT as a treatment procedure. The study was conducted as a departmental pilot survey for quality improvement of Psychiatry Undergraduate Training. A total of 128 medical students in early clinical year enrolled in MBBS curriculum at a teaching hospital in Southern Nepal participated in the survey. The students were not exposed to any specific teaching regarding ECT while participating in the study.ResultThe students were aged between 21 and 28 years with almost equal gender distribution. Among them, 89.1% had heard about ECT before whereas 15.6% knew someone who has received ECT. Although 90.6 % of students believed ECT can be lifesaving many times, a substantial number of students had misconception about ECT such as assuming it as a painful procedure (71.9%). Almost half of them believed ECT can have severe consequences like death or permanent brain damage. Around one fourth to one third believed ECT is inhumane, without scientific proof or a form of punishment for violent angry patients. Surprisingly, a significant higher percentage of male students believed that ‘ECT leads to permanent loss of memory’ (11/34 vs. 3/30, p = 0.04) and ‘ECT is given as a punishment to violent/angry patients’ (15/34 vs. 4/30, p = 0.01).ConclusionSeveral misconceptions about ECT are prevalent in medical students that need to be adequately addressed during their training to develop a positive attitude and basic knowledge about the treatment.

Background TikTok is a recent type of video-sharing and lip-syncing online platform that is influencing adolescents rapidly and is likely to surge in view of increased use of smart-phones, internet use, ‘Lockdown’ period due to COVID-19pandemic and increasing online transactions, teachings and daily affairs worldwide. Case presentation Two teenaged girls from southern Nepal brought by their parents with problematic use of TikTok and behavioural problems that followed .They were engrossed in the mobile application that resulted in impairment at a personal, social, educational and family functioning.In addition to that, parents did not accept it on cultural grounds. However, patients did not consider it problematic .Gradually, they developed symptoms of depression, conduct disorder and oppositional defiant disorder but did not fulfill criteria of any disorder. The provisional diagnosis of Behavioural addiction was considered and Cognitive behavioural therapy planned. These cases posed diagnostic dilemma, challenging treatment sessions and partial success. Conclusions The line between normal and abnormal use of such mobile application is hazy in context of its social acceptability and growing use. The conflict appeared between traditional values and modern means of entertainment poses therapeutic challenge. Authors advise parental involvement, psychotherapeutic means, behavioral therapy and a collaborative approach with adolescents rather than pharmacotherapy for comprehensive treatment.

Multiphysics multiscale electrochemical flow systems are challenging from the viewpoint of understanding their behavior and predicting their performance owing to their large number of design, material, and operational variables. Dimensional analysis offers a method for reducing such complex physical problems to the simplest form to facilitate a qualitative understanding of the system behavior along with quantitative description of the problem defined. This paper reports a dimensional analysis of a flow-by porous electrode, the main constituent of modern electrochemical flow systems. A step-by-step analysis is carried out starting with 15 primitive variables (including cell voltage as performance measure) and resulting in 7 dimensionless variables only to define the system. The paper goes beyond the reduction of number of variables. Physical significance of the identified dimensionless variables is deliberated to understand the role of underlying transport phenomena in the system, mainly in terms of irreversible losses. Further, the reliability of the dimensionless variables is established by performing scale modeling for an all-vanadium redox flow battery (VRFB) system via virtual experiments. Finally, a functional relationship, in the form of an empirical correlation among the dimensionless variables, is derived that can be utilized for predicting cell voltages of a VRFB system at specific conditions.

Exploring new materials for efficient energy storage is imperative to derive uninterrupted energy supply from non-conventional sustainable sources. The present paper reports on the synthesis of a new Cu-MOF (HMRL-1), involving the reaction of a tetracarboxylic linker and Cu2+ salt under solvothermal conditions. Using a simple ultrasonication approach, the as-synthesized MOF has been further used to fabricate a composite with reduced graphene oxide (rGO) (R). The resulting composite (HMRL-1/R) has been explored as a binder-free supercapacitor electrode material for deriving enhanced charge storage capacity. The supercapacitor performance of the composite material has been investigated by cyclic voltammetry (CV), galvanostatic charge-discharge (GCD), and electrochemical impedance spectroscopy (EIS). The electrochemical investigations reveal that HMRL-1/R composite exhibits hybrid capacitive features with a specific capacitance (CS) of 366.6 Fg−1 at 1 Ag−1 and excellent cyclic stability and performance retention, which is much higher than that of pristine HMRL-1 and R due to their synergistic effect. All the findings suggest that as-prepared material is a promising candidate for an electrode material in supercapacitor applications.

The development of new materials capable of fixing CO2 into value-added products has become an exciting research field. Besides mitigating the rising level of CO2, such materials also enable CO2 as a C1 carbon source for useful industrial synthons. This article reports on the stepwise synthesis of a melamine functionalized silica-coated iron oxide (FSNM) material for selective CO2 capture and its catalytic conversion into a useful product. The synthesis of FSNM has been achieved by covalently grafting the melamine group in the pores of mesoporous silica-coated Fe3O4 (Fe3O4@SiO2) particle using isocyanate as a cross-linker. While the Fe3O4 core, owing to its superparamagnetic property, enables the easy retrieval of the material from the reaction mixture and, thus, enhances the recyclability, mesoporous silica coating offers a larger surface area for adsorption. The organic functionalities, containing melamine and carbamide moieties, facilitate the selective adsorption of CO2 on the material with a maximum CO2 uptake of 0.48 mmol/g at 1 bar and 298 K with excellent CO2/N2 selectivity. Moreover, the acid-base interactions between the acidic CO2 and basic amine groups enable the FSNM to catalyze the cycloaddition of CO2 with different epoxides to afford a series of cyclic carbonates, in the presence of tetrabutylammonium bromide (TBAB) as a co-catalyst, under facile and solvent-free conditions. These results strongly support that melamine functionalized Fe3O4@SiO2 affords new aspects towards environmentally friendly and recoverable hybrid adsorbent for adsorption and fixation of CO2 into the valuable products.

The laminar forced convection momentum and heat transfer aspects of a circular disk oriented normal to the flow and maintained at a constant flux or a constant temperature condition in a stream of ...

In this work, the buoyancy-induced convection from an isothermal spheroid is studied in a Bingham plastic fluid. Extensive results on the morphology of approximate yield surfaces, temperature profiles, and the local and average Nusselt numbers are reported to elucidate the effects of the pertinent dimensionless parameters: Rayleigh number, 102 ≤ Ra ≤ 106; Prandtl number, 20 ≤ Pr ≤ 100; Bingham number, 0 ≤ Bn ≤ 103, and aspect ratio, 0.2 ≤ e ≤ 5. Due to the fluid yield stress, fluid-like (yielded) and solid-like (unyielded) regions coexist in the flow domain depending upon the prevailing stress levels vis-a-vis the value of the fluid yield stress. The yielded parts progressively grow in size with the rising Rayleigh number while this tendency is countered by the increasing Bingham and Prandtl numbers. Due to these two competing effects, a limiting value of the Bingham number (Bn max) is observed beyond which heat transfer occurs solely by conduction due to the solid-like behaviour of the fluid everywhere in the domain. Such limiting values bear a positive dependence on the Rayleigh number (Ra) and aspect ratio (e). In addition to this, oblate shapes (e 1) impede it. Finally, simple predictive expressions for the maximum Bingham number and the average Nusselt number are developed which can be used to predict a priori the overall heat transfer coefficient in a new application. Also, a criterion is developed in terms of the composite parameter Bn∙Gr-1/2 which predicts the onset of convection in such fluids. Similarly, another criterion is developed which delineates the conditions for the onset of settling due to buoyancy effects. The paper is concluded by presenting limited results to delineate the effects of viscous dissipation and the temperature-dependent viscosity on the Nusselt number. Both these effects are seen to be rather small in Bingham plastic fluids.

The momentum and thermal energy equations describing the forced convection heat transfer from a heated sphere settling at the axis of a long cylindrical tube filled with a power-law fluid have been solved numerically. The extensive new results reported herein encompass wide ranges of conditions as: Reynolds number, 1 ≤ Re ≤ 100; Prandtl number, 5 ≤ Pr ≤ 100, power-law index, 0.2 ≤ n ≤ 2 and blockage ratio, 0.5 ≤ λ ≤ 0.95. The range of values of the power-law index (n) used here include both the shear-thinning (n 1) fluid behaviours. The overall heat transfer is strongly modulated by Re, n and λ depending upon whether the recirculation region is formed in the rear of the sphere and/or on the proximity of the tube wall. Furthermore, the results reported herein elucidate the effect of the type of thermal boundary condition (isothermal or isoflux) on the surface of the sphere as well as that of the velocity profile (uniform or fully developed Poiseuille profile) in the tube. Overall, the average Nusselt number bears a positive dependence on the Reynolds and Prandtl numbers and blockage ratio. The shear-thinning behaviour (n 1) adversely influences it. The present numerical results (~ 4000 data) have been consolidated by incorporating the blockage factor into an existing expression valid for λ = 0 for Newtonian fluids.

The flexible carboxylate linker, H3L = 5-(2-carboxybenzyloxy)isophthalic acid, and a group of N-donor co-linkers such as 1,2-di(4-pyridyl)ethylene (dpe), 1,2-di(4-pyridyl)ethane (1,2-dpe), 1,2-di(pyridin-4-yl)diazene (dpd), and 1,3-di(4-pyridyl)propane (1,3-dpp), give rise to five new coordination polymers (CPs) with Zn(II) ions. These are {[Zn2(L)(μ-OH)(dpe)(H2O)]}n (1), {[Zn(L)(1,2-dpe)1.5]·H2O}n (2), {[Zn(HL)(dpd)1.5]2·2(H2O)}n (3), {[Zn(HL)(1,3-dpp)]}n (4), and {[Zn5(L)4(H2O)2]·8(H2O) (1,2-dpe)}n (5). CP 1 forms a densely packed 3D framework with a rare topological type, ose; 7/3/o5; sqc59. Both CP 2 and 3 form [2+2] metallacyclic units which form a 1D chain that links other chains by strong O–H⋯N type H-bonding to result in a 3D supramolecular network. CP 4 forms a 2D sheet structure stacking over each other by C–H⋯π and π⋯π interactions, to give rise to a 3D H-bonded supramolecular structure with topological type, sql/Shubnikov. CP 5 has two types of SBUs with a 3D anionic network where channels are filled up with the cationic 1,2-dpe ligands and water molecules which shows rare topological type, 6,10T9. The photoluminescence sensing of nitroaromatic compounds, especially 2,4,6-trinitrophenol (TNP), by 1–5 indicates that these CPs could be potential candidates for developing luminescent sensors for selective sensing of these species.

In this work, the effects of the power-law and Bingham plastic viscosity on the flow and heat transfer characteristics of laminar forced convection through non-circular ducts of a range of cross-sections have been investigated numerically over the wide ranges of Peclet number, 10 ⩽ ( Pe = Re · Pr ) ⩽ 10 4 , power-law index, 0.2 ⩽ n ⩽ 2 and Bingham number, 0 ⩽ Bn ⩽ 15 . Two different thermal boundary conditions (constant wall temperature and constant wall heat flux) on the duct wall have been implemented. Extensive results for the flow and temperature fields in terms of the dimensionless velocity and temperature profiles, pressure drop and local and average Nusselt number are presented and discussed both in the developing and fully developed regions. For the sake of conciseness, the results for three duct shapes, namely, semi-circular, four cusped and rectangular, are presented and discussed in detail whereas that for the other shapes are summarised in a tabular form. The dependence of the Poiseuille number ( f · Re ) and asymptotic Nusselt number ( Nu ) on the power-law index ( n ) and Bingham number ( Bn ) is studied under fully developed (hydrodynamically and thermally) conditions. It is shown that the fanning friction factor has a positive dependence on the increasing values of power-law index while an opposite dependence is observed for the Nusselt number. Finally, simple predictive correlations for hydrodynamic entrance length and Nusselt number are developed as functions of the generalised Reynolds number ( Re g ) , Graetz number ( Gz ) , power-law index or the Bingham number. The paper is concluded by comparing the predictions of the power-law model with that of the extended modified power-law (EMPL) model for a semi-circular duct in order to ascertain the influence of the deficiencies of the power-law equation in capturing the zero- and infinite-shear viscosities on the present results.