The lecture is in two parts, viz., 'Human civilization and early materials for energy' and 'infor... more The lecture is in two parts, viz., 'Human civilization and early materials for energy' and 'information'. Since the beginning of the civilization from hunters to food gatherers to dwellers until the modern form of civilization, human have invented, discovered huge number of methods for harvesting energies. Almost all the methods were primarily based on renewable methods until fossil fuel based industrialization came into existence which changed every course of life and survival on this earth. The second part of the lecture deals with the 'History of Information Technology'. Materials for information through ages- Early materials and methods for storing information. Advent of paper, ink and other writing surfaces.
Lecture 2: Renewable Energy-Need of the hour is in five parts:
Part 1- Burning of Fossil Fuels an... more Lecture 2: Renewable Energy-Need of the hour is in five parts: Part 1- Burning of Fossil Fuels and Pollution Part 2- Hidden Cost of Fossil Fuels Part 3- Global Warming and its Consequences Part 4- Extinction of Islands and Species Part 5- Renewable Energy, Current Status and Future Directions
Extinction of Islands and Species as a consequence of excessive pollution and air, water and the ... more Extinction of Islands and Species as a consequence of excessive pollution and air, water and the earth.
Citrus is one of the largest and most popular fruit crops commercially grown across the globe. It... more Citrus is one of the largest and most popular fruit crops commercially grown across the globe. It is not only important in terms of economy but is also popular for its nutritional benefits to human and farm animals. Citrus is available in several varieties, all with attractive colors. It is consumed either fresh or in processed form. After processing, approximately 50% of the fruit remains unconsumed and discarded as waste. The latter includes fruit pith residue, peels and seeds. Direct disposal of these wastes to the environment causes serious problems as these contain bioactive compounds. Release of these bioactive compounds to the open landfills cause bad odor and spread of diseases, and disposal to water bodies or seepage to the underground water table deteriorates water quality and harms aquatic life. In this regard, a number of research are being focused on the development of better reuse methods to obtain value-added phytochemicals as well as for safe disposal. The important phytochemicals obtained from citrus include essential oils, flavonoids, citric acid, pectin, etc., which have now become popular topics in industrial research, food and synthetic chemistry. The present article reviews recent advances in exploring the effects of flavonoids obtained from citrus wastes, the extraction procedure and their usage in view of various health benefits.
Cosmetics have always been in demand across the globe among people of all age groups. In the mode... more Cosmetics have always been in demand across the globe among people of all age groups. In the modern cosmetic world, nanostructured materials have proven hugely advantageous in producing cosmeceuticals or ‘nano-cosmeceuticals’ and various beauty products. The application of nanostructured materials in cosmetic products possesses some challenges in terms of short- and long-term safety and environmental issues, despite their growing popularity. The nanostructured particles in cosmeceuticals provide a targeted route of administration due to their high penetrability, site selectivity, high effectiveness, prolonged activity, and drug encapsulation potential. However, standard methods for toxicity evaluation may not be relevant for cosmeceuticals, leading to the need for an alternative methodology. This review article compiles detailed descriptions of all significant aspects of nanostructured materials in the cosmetics industry, which include the synthesis and characterization of relevant ...
The lecture is in two parts, viz., 'Human civilization and early materials for energy' and 'infor... more The lecture is in two parts, viz., 'Human civilization and early materials for energy' and 'information'. Since the beginning of the civilization from hunters to food gatherers to dwellers until the modern form of civilization, human have invented, discovered huge number of methods for harvesting energies. Almost all the methods were primarily based on renewable methods until fossil fuel based industrialization came into existence which changed every course of life and survival on this earth. The second part of the lecture deals with the 'History of Information Technology'. Materials for information through ages- Early materials and methods for storing information. Advent of paper, ink and other writing surfaces.
Lecture 2: Renewable Energy-Need of the hour is in five parts:
Part 1- Burning of Fossil Fuels an... more Lecture 2: Renewable Energy-Need of the hour is in five parts: Part 1- Burning of Fossil Fuels and Pollution Part 2- Hidden Cost of Fossil Fuels Part 3- Global Warming and its Consequences Part 4- Extinction of Islands and Species Part 5- Renewable Energy, Current Status and Future Directions
Extinction of Islands and Species as a consequence of excessive pollution and air, water and the ... more Extinction of Islands and Species as a consequence of excessive pollution and air, water and the earth.
Citrus is one of the largest and most popular fruit crops commercially grown across the globe. It... more Citrus is one of the largest and most popular fruit crops commercially grown across the globe. It is not only important in terms of economy but is also popular for its nutritional benefits to human and farm animals. Citrus is available in several varieties, all with attractive colors. It is consumed either fresh or in processed form. After processing, approximately 50% of the fruit remains unconsumed and discarded as waste. The latter includes fruit pith residue, peels and seeds. Direct disposal of these wastes to the environment causes serious problems as these contain bioactive compounds. Release of these bioactive compounds to the open landfills cause bad odor and spread of diseases, and disposal to water bodies or seepage to the underground water table deteriorates water quality and harms aquatic life. In this regard, a number of research are being focused on the development of better reuse methods to obtain value-added phytochemicals as well as for safe disposal. The important phytochemicals obtained from citrus include essential oils, flavonoids, citric acid, pectin, etc., which have now become popular topics in industrial research, food and synthetic chemistry. The present article reviews recent advances in exploring the effects of flavonoids obtained from citrus wastes, the extraction procedure and their usage in view of various health benefits.
Cosmetics have always been in demand across the globe among people of all age groups. In the mode... more Cosmetics have always been in demand across the globe among people of all age groups. In the modern cosmetic world, nanostructured materials have proven hugely advantageous in producing cosmeceuticals or ‘nano-cosmeceuticals’ and various beauty products. The application of nanostructured materials in cosmetic products possesses some challenges in terms of short- and long-term safety and environmental issues, despite their growing popularity. The nanostructured particles in cosmeceuticals provide a targeted route of administration due to their high penetrability, site selectivity, high effectiveness, prolonged activity, and drug encapsulation potential. However, standard methods for toxicity evaluation may not be relevant for cosmeceuticals, leading to the need for an alternative methodology. This review article compiles detailed descriptions of all significant aspects of nanostructured materials in the cosmetics industry, which include the synthesis and characterization of relevant ...
We report on a simple surfactant/template free chemical route for the synthesis of semi-polycryst... more We report on a simple surfactant/template free chemical route for the synthesis of semi-polycrystalline polyaniline-graphite (SPani-graphite) composite and its application as an electroactive material in electrochemical charge storage. The synthesized material exhibits well-defined poly-crystallographic lattices in high resolution transmission electron micrographs and sharp peaks in x-ray diffraction spectra suggesting crystalline nature of the material. The specific capacitance computed from the galvanostatic charge-discharge (GCD) data obtained from 3-electrode cell configuration using 1 M aq. Na 2 SO 4 as an electrolyte was 111.4 F g − 1 at a current density of 0.1 A g − 1 which rises to 269 F g − 1 at an elevated current density of 1.0 A g − 1. A similar pattern of increase in the specific capacitance values with an increase in the current density was observed in the results obtained from 2electrode symmetric device configuration using polymer gel electrolyte (xanthan gum in 1 M aq. Na 2 SO 4). The specific capacitance computed from the GCD data obtained from the device configuration was 20 F g − 1 at the current density of 1.0 A g − 1. The device delivers an energy density of 1.7 Wh kg − 1 and a power density of 2.48 kWh kg − 1 at an applied current density of 0.5 A g − 1 suggesting an excellent rate capability and power management. In addition, the device exhibits ⁓92 % specific capacitance retention up to 8000 continuous GCD cycles and ⁓80 % coulombic efficiency up to 10,000 continuous GCD cycles indicating excellent cycling stability. The unique feature of increasing specific capacitance with respect to applied current density is attributed to the presence of semi-polycrystalline phases in the SPani-graphite matrix. The material behaves as a surface redox supercapacitor and its unique mechanism of charge storage is discussed in detail in the article.
We report on a template/surfactant free, simple chemical synthesis, material properties, electroc... more We report on a template/surfactant free, simple chemical synthesis, material properties, electrochemical behavior, and device performance of semi-polycrystalline polyaniline-multiwalled carbon nanotube (SPani-MWNT) composite as supercapacitor electrode. The specific capacitances (C sp) exhibit a unique, yet interesting pattern attributable to the presence of crystalline phases in the material. The electrode delivers a C sp of 359 F g − 1 at a current density (CD) of 1 A/g, which declines to a lower value of 257 F g − 1 at 5 A/g and gains a higher value of 444 F g − 1 at 10 A/g in a 3-electrode cell configuration using 1 M aq.Na 2 SO 4 as an electrolyte. Similar pattern of results is observed during performance of SPani-MWNT‖SPani-MWNT in a 2-electrode symmetrical device configuration with polymer gel electrolyte (xanthan gum in 1 M aq.Na 2 SO 4). The device delivers a C sp of 56 F g − 1 , energy density of 5 Wh Kg − 1 , and a power density of 365 W kg − 1 at an applied CD of 0.5 A/g. At a higher CD of 10 A/g, the device delivers energy density of ~4 Wh kg − 1 and power density of 6.7 kW kg − 1. In addition, the device exhibits good electrochemical reversibility with cycling stability, retention of ~80 % of its initial capacitance and 99 % of initial coulombic efficiency over 10,000 continuous GCD cycles at an applied CD of 0.5 A/g. The results indicate excellent rate capability and power management.
Doping of ceria into yttria-stabilized zirconia (YSZ) has been reported to have improved the prop... more Doping of ceria into yttria-stabilized zirconia (YSZ) has been reported to have improved the properties in terms of thermal insulation capability, ionic conductivity, and mechanical- and phase-stability of YSZ for applications as potential electrolyte materials workable at intermediate temperature range (500–700°C). In order to select an appropriate amount of ceria to be added, it is important to understand the effects of the added dopants on phase and microstructure, lattice parameters, and mechanical properties. This paper presents synthesis and characterization (of phase, microstructural, and mechanical properties at micron and nanoscale level) of 8 mol. % Y2O3-ZrO2 (8YSZ) containing 0, 5, and 10 wt. % CeO2 via spark plasma sintering. Microstructural analysis has elicited increased grain growth with increasing CeO2 content in 8YSZ. Phase analysis has indicated formation of solid solution with dilation of 8 YSZ lattice upon CeO2 addition. In contrast, isolated ceria rich zones have been identified through energy dispersive spectroscopy (attachment in transmission electron microscope) affirming the formation of CeO2-8YSZ composite. Microhardness (H), and fracture toughness (KIC) of CeO2-8YSZ electrolytes were observed to degrade by 31·2% and 24.0%, respectively, for 10 wt.% CeO2-8YSZ samples in comparison to that of 8YSZ alone. Whereas, the hardness and reduced modulus of CeO2-8YSZ samples, evaluated using nanoindentation did not reveal any significant difference in the mechanical properties of the developed composites. Difference in the mechanical properties using Vickers indentation is attributed to the presence of porosity, which is negated in the mechanical property evaluation via nanoindentation.
We report on a simple surfactant/template free chemical route for the synthesis of semi-polycryst... more We report on a simple surfactant/template free chemical route for the synthesis of semi-polycrystalline polyaniline-graphite (SPani-graphite) composite and its application as an electroactive material in electrochemical charge storage. The synthesized material exhibits well-defined poly-crystallographic lattices in high resolution transmission electron micrographs and sharp peaks in x-ray diffraction spectra suggesting crystalline nature of the material. The specific capacitance computed from the galvanostatic charge-discharge (GCD) data obtained from 3-electrode cell configuration using 1 M aq. Na 2 SO 4 as an electrolyte was 111.4 F g − 1 at a current density of 0.1 A g − 1 which rises to 269 F g − 1 at an elevated current density of 1.0 A g − 1. A similar pattern of increase in the specific capacitance values with an increase in the current density was observed in the results obtained from 2electrode symmetric device configuration using polymer gel electrolyte (xanthan gum in 1 M aq. Na 2 SO 4). The specific capacitance computed from the GCD data obtained from the device configuration was 20 F g − 1 at the current density of 1.0 A g − 1. The device delivers an energy density of 1.7 Wh kg − 1 and a power density of 2.48 kWh kg − 1 at an applied current density of 0.5 A g − 1 suggesting an excellent rate capability and power management. In addition, the device exhibits ⁓92 % specific capacitance retention up to 8000 continuous GCD cycles and ⁓80 % coulombic efficiency up to 10,000 continuous GCD cycles indicating excellent cycling stability. The unique feature of increasing specific capacitance with respect to applied current density is attributed to the presence of semi-polycrystalline phases in the SPani-graphite matrix. The material behaves as a surface redox supercapacitor and its unique mechanism of charge storage is discussed in detail in the article.
We report on a template/surfactant free, simple chemical synthesis, material properties, electroc... more We report on a template/surfactant free, simple chemical synthesis, material properties, electrochemical behavior, and device performance of semi-polycrystalline polyaniline-multiwalled carbon nanotube (SPani-MWNT) composite as supercapacitor electrode. The specific capacitances (C sp) exhibit a unique, yet interesting pattern attributable to the presence of crystalline phases in the material. The electrode delivers a C sp of 359 F g − 1 at a current density (CD) of 1 A/g, which declines to a lower value of 257 F g − 1 at 5 A/g and gains a higher value of 444 F g − 1 at 10 A/g in a 3-electrode cell configuration using 1 M aq.Na 2 SO 4 as an electrolyte. Similar pattern of results is observed during performance of SPani-MWNT‖SPani-MWNT in a 2-electrode symmetrical device configuration with polymer gel electrolyte (xanthan gum in 1 M aq.Na 2 SO 4). The device delivers a C sp of 56 F g − 1 , energy density of 5 Wh Kg − 1 , and a power density of 365 W kg − 1 at an applied CD of 0.5 A/g. At a higher CD of 10 A/g, the device delivers energy density of ~4 Wh kg − 1 and power density of 6.7 kW kg − 1. In addition, the device exhibits good electrochemical reversibility with cycling stability, retention of ~80 % of its initial capacitance and 99 % of initial coulombic efficiency over 10,000 continuous GCD cycles at an applied CD of 0.5 A/g. The results indicate excellent rate capability and power management.
One of the hugely focused areas of research for addressing the world’s energy and environmental c... more One of the hugely focused areas of research for addressing the world’s energy and environmental challenges is electrochemical water oxidation. Morphological modulation of nanomaterials is essential for producing efficient electrocatalysts to achieve the required results. The purpose can be achieved by controlling synthesis parameters, and this is a key factor which greatly influences the oxygen evolution reaction (OER) performance during electrochemical water splitting. In this study, synthesis of cobalt molybdate (CoMoO4) through a simple and low-cost hydrothermal/solvothermal strategy with tunable morphology is demonstrated. Different morphologies, namely rods-like, buds-like, and sheets-like, referred to as R-CMO, B-CMO, and S-CMO, respectively, have been obtained by systematically varying the solvent media. Their catalytic activity towards OER was investigated in 1.0 M aqueous KOH medium. R-CMO nanoparticles synthesized in an aqueous medium demonstrated the lowest overpotential ...
This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY
Citrus is one of the main fruit crops cultivated in tropical and subtropical regions worldwide. A... more Citrus is one of the main fruit crops cultivated in tropical and subtropical regions worldwide. Approximately half (40–47%) of the fruit mass is inedible and discarded as waste after processing, which causes pollution to the environment. Essential oils (EOs) are aromatic compounds found in significant quantities in oil sacs or oil glands present in the leaves, flowers, and fruit peels (mainly the flavedo part). Citrus EO is a complex mixture of ~400 compounds and has been found to be useful in aromatic infusions for personal health care, perfumes, pharmaceuticals, color enhancers in foods and beverages, and aromatherapy. The citrus EOs possess a pleasant scent, and impart relaxing, calming, mood-uplifting, and cheer-enhancing effects. In aromatherapy, it is applied either in message oils or in diffusion sprays for homes and vehicle sittings. The diffusion creates a fresh feeling and enhances relaxation from stress and anxiety and helps uplifting mood and boosting emotional and physi...
Citrus is one of the main fruit crops cultivated in tropical and subtropical regions worldwide. A... more Citrus is one of the main fruit crops cultivated in tropical and subtropical regions worldwide. Approximately half (40–47%) of the fruit mass is inedible and discarded as waste after processing, which causes pollution to the environment. Essential oils (EOs) are aromatic compounds found in significant quantities in oil sacs or oil glands present in the leaves, flowers, and fruit peels (mainly the flavedo part). Citrus EO is a complex mixture of ~400 compounds and has been found to be useful in aromatic infusions for personal health care, perfumes, pharmaceuticals, color enhancers in foods and beverages, and aromatherapy. The citrus EOs possess a pleasant scent, and impart relaxing, calming, mood-uplifting, and cheer-enhancing effects. In aromatherapy, it is applied either in message oils or in diffusion sprays for homes and vehicle sittings. The diffusion creates a fresh feeling and enhances relaxation from stress and anxiety and helps uplifting mood and boosting emotional and physical energy. This review presents a comprehensive outlook on the composition, properties, characterization, and mechanism of action of the citrus EOs in various health-related issues, with a focus on its antioxidant properties.
Keywords: citrus essential oils; aromatherapy; natural aromatic compounds; therapeutic effects of citrus EOs; characterization of citrus EOs
We report on the synthesis of activated carbon-semi-polycrystalline polyaniline (SPani-AC) compos... more We report on the synthesis of activated carbon-semi-polycrystalline polyaniline (SPani-AC) composite material using in-situ oxidative polymerization of aniline on the carbon surface in an aqueous HCl medium at an elevated temperature of 60 °C. The electroactive polymeric composite material exhibits a uniformly distributed spindle-shaped morphology in scanning electron microscopy (SEM) and well-defined crystallographic lattices in the high-resolution transmission electron microscopy (TEM) images. The X-ray diffraction (XRD) spectrum reveals sharp peaks characteristic of crystalline polyaniline. The characteristic chemical properties of polyaniline are recorded using laser Raman spectroscopy. The cyclic voltammetry curves exhibit features of surface-redox pseudocapacitance. The specific capacitance calculated for the material is 507 F g −1 at the scan rate of 10 mV s −1. The symmetrical two-electrodes device exhibits a specific capacitance of 45 F g −1 at a current density of 5 A g −1. The capacitive retention calculated was found to be 96% up to 4500 continuous charge-discharge cycles and observed to be gradually declining at the end of 10,000 cycles. On the other hand, Coulombic efficiency was observed to be retained up to 85% until 4500 continuous charge-discharge cycles which declines up to 72% at the end of 10000 cycles. The article also presents a detailed description of material synthesis, the formation of polyaniline (Pani) chains, and the role of material architecture in the performance as surface redox supercapacitor electrode.
Citrus fruits are one of the most popular sources of dietary flavonoids, such as hesperidin, hesp... more Citrus fruits are one of the most popular sources of dietary flavonoids, such as hesperidin, hesperetin, naringin, naringenin, quercetin, rutin, diosmin, diosmetin, kaempferol, myricetin, nobiletin, tangeretin, and so on. Flavonoids are polyphenols and aromatic bioactive compounds occurring in plants as secondary metabolites. These participate in various biochemical processes in the human body and help in promoting health. Citrus flavonoids are well-known for their antioxidant and anti-inflammatory properties. They promote wound healing and antimelanoma in addition to free radical scavenging, apoptosis, modulation of lipid metabolism, improvement of insulin sensitivity, and endothelial dysfunction. Citrus flavonoids serve as efficient therapeutics for treating various skin-related issues, such as skin aging/photoaging, skin pigmentation, and maintenance of overall healthy skin. This review is an attempt to compile relevant information from recently published articles addressing the roles of Citrus flavonoids in health-promoting activities, particularly skin health. In addition, it also provides a discussion on the recent progress in developing efficient topical delivery techniques to solve the challenge of flavonoids' poor water solubility and limited permeability into the skin. The review aims to provide a better understanding of the current trends in research and development in Citrus flavonoid biochemistry and their usage in the production of plant-based medicinal and pharma-/nutraceuticals for topical applications.
This is the fifth and last part of this lecture. In this part we shall take up three topics to di... more This is the fifth and last part of this lecture. In this part we shall take up three topics to discuss, viz., Renewable energy methods; Current status of the renewable energy; and Future directions • As of the topics we discussed in the previous parts of this lecture, we have come to an idea there cannot be a possibility of looking back towards continuing the old methods of harvesting energy and risking the life further to a new height of damages beyond control. We should now focus to develop the workable and sustainable energy mechanisms.
Lecture 2: Renewable Energy: Need of the Hour. This lecture is in five parts under topics; Part-1... more Lecture 2: Renewable Energy: Need of the Hour. This lecture is in five parts under topics; Part-1: Burning of Fossil Fuels and Pollution; Part-2: Hidden Costs of Fossil Fuels Part 3: Global Warming and its Consequences Part 4: Extinction of Islands and Species Part 5: Renewable Energy, Current Status and Future Directions
Lecture 2: Renewable Energy: Need of the Hour. This lecture is in five parts under topics; Part-1... more Lecture 2: Renewable Energy: Need of the Hour. This lecture is in five parts under topics; Part-1: Burning of Fossil Fuels and Pollution; Part-2: Hidden Costs of Fossil Fuels Part 3: Global Warming and its Consequences Part 4: Extinction of Islands and Species Part 5: Renewable Energy, Current Status and Future Directions
Lecture 2: Renewable Energy: Need of the Hour. This lecture is in five parts under topics; Part-1... more Lecture 2: Renewable Energy: Need of the Hour. This lecture is in five parts under topics; Part-1: Burning of Fossil Fuels and Pollution; Part-2: Hidden Costs of Fossil Fuels Part 3: Global Warming and its Consequences Part 4: Extinction of Islands and Species Part 5: Renewable Energy, Current Status and Future Directions
Lecture 2: Renewable Energy: Need of the Hour. This lecture is in five parts under topics; Part-1... more Lecture 2: Renewable Energy: Need of the Hour. This lecture is in five parts under topics; Part-1: Burning of Fossil Fuels and Pollution; Part-2: Hidden Costs of Fossil Fuels Part 3: Global Warming and its Consequences Part 4: Extinction of Islands and Species Part 5: Renewable Energy, Current Status and Future Directions; Assignment Questions: 1. Which part of the pollution discussed in this lecture do you think is the most dangerous for the life on the planet and why? 2. Which of the changes in the environment do you find dangerously serious and need immediate solution and why?
Lecture I: A brief history of materials
Part-III: Materials for Information Counting numbers and ... more Lecture I: A brief history of materials Part-III: Materials for Information Counting numbers and road to modern technology
City life has its own advantage. We live a comfortable life. We happen to find every facility at ... more City life has its own advantage. We live a comfortable life. We happen to find every facility at our vicinity, and we become used to a comfortable life. And, this gives us moretime and space to create better things for humankind, either philosophies or commodities.The different commodities, we utilize in our everyday life come from different sources.Food is one such fundamental product which always existed deep in my thoughts. Backat my home, I used to grow certain vegetables, flowers, and cereal grains with mygrandparents in my hometown in India. Food for thought and its cultivation involvesmany elements, namely philosophy, resources, as well as labor. Exploring rural lifeexperiences through seasonal work programs involving working in agricultural farms isone such opportunity to learn and add value to one’s experience and knowledge. Inaddition, the possibilities of building cordial human bondages with people from differentnations also create opportunities of innovations and scientific research in saving soil andresisting climate change.
Translated in Bengali language by Saeem Ferdous, Dhaka, Bangladesh
The New Year's day is observed as a day of joy, music, food, celebrations, hope and eager expecta... more The New Year's day is observed as a day of joy, music, food, celebrations, hope and eager expectations. Everyone hopes for one's self and wishes to others a happy, prosperous, and peaceful life the year throughout; shed old thoughts and adapt to new and novel thoughts; ring out the old and ring in the new! • But, the very next day, the newness we celebrated a day ago appears to fade and so does the energy within! The western concept and philosophy of celebrating new year is often criticized for this reason.
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Videos by Neelima Mahato
Part 1- Burning of Fossil Fuels and Pollution
Part 2- Hidden Cost of Fossil Fuels
Part 3- Global Warming and its Consequences
Part 4- Extinction of Islands and Species
Part 5- Renewable Energy, Current Status and Future Directions
Papers by Neelima Mahato
Part 1- Burning of Fossil Fuels and Pollution
Part 2- Hidden Cost of Fossil Fuels
Part 3- Global Warming and its Consequences
Part 4- Extinction of Islands and Species
Part 5- Renewable Energy, Current Status and Future Directions
Keywords: citrus essential oils; aromatherapy; natural aromatic compounds; therapeutic effects of citrus EOs; characterization of citrus EOs
Part-III: Materials for Information Counting numbers and road to modern technology
Translated in Bengali language by Saeem Ferdous, Dhaka, Bangladesh