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Proper management of biogenic residues, particularly livestock manure and food waste, is a major challenge for Bangladesh. While mono-digestion has traditionally been used on farms for treating manure, inadequate energetic output limits its applicability. Food waste, however, is typically landfilled in current practice. Co-digestion of biowaste emerged as an alternative due to synergistic yield and capacity to handle multiple waste streams. However, its environmental performance is underreported, particularly in developing countries. This study aimed to compare the environmental implications of co-digestion and mono-digestion of livestock manure (poultry and cow manure) with food waste from a life cycle assessment perspective for the regional context of Bangladesh. Two inventory cases were considered, accounting for mechanistically calculated (case M) and experimentally reported synergistic biogas yield (case E). Co-digestion scenarios showed net benefits by reducing three of the five impact categories-considerably reducing climate change (up to 117%), eutrophication potential, and terrestrial ecotoxicity in both cases (54.5 % and 55.7 %, respectively). The highest decrease occurred for climate change by diverting food waste landfilling. However, when synergistic biogas yield was considered, acidification potential and malodor air emissions increased by co-digestion owing to a higher amount of hydrogen sulfide and ammonia in the produced gas, thus entailing significant environmental burdens. The key hotspot in most categories was open storage of digestate, necessitating appropriate post-treatment.

Here we report a jute endophyte Staphylococcus hominis strain MBL_AB63 isolated from jute seeds which showed promising antimicrobial activity against Staphylococcus aureus SG511 when screening for antimicrobial substances. The whole genome sequence of this strain, annotated using BAGEL4 and antiSMASH 5.0 to predict the gene clusters for antimicrobial substances identified a novel antimicrobial peptide cluster that belongs to the class I lantibiotic group. The predicted lantibiotic (homicorcin) was found to be 82% similar to a reported peptide epicidin 280 having a difference of seven amino acids at several positions of the core peptide. Two distinct peaks obtained at close retention times from a RP-HPLC purified fraction have comparable antimicrobial activities and LC–MS revealed the molecular mass of these peaks to be 3046.5 and 3043.2 Da. The presence of an oxidoreductase (homO) similar to that of epicidin 280- associated eciO or epilancin 15X- associated elxO in the homicorcin gene cluster is predicted to be responsible for the reduction of the first dehydrated residue dehydroalanine (Dha) to 2-hydroxypropionate that causes an increase of 3 Da mass of homicorcin 1. Trypsin digestion of the core peptide and its variant followed by ESI–MS analysis suggests the presence of three ring structures, one in the N-terminal and other two interlocking rings at the C-terminal region that remain undigested. Homicorcin exerts bactericidal activity against susceptible cells by disrupting the integrity of the cytoplasmic membrane through pore formation as observed under FE-SEM.

We have previously reported that water addition (∼1000 ppm) to an N-methyl-N-propylpyrrolidinium bis(fluorosulfonyl)imide (C3mpyrFSI) superconcentrated ionic liquid electrolyte (50 mol % NaFSI) promoted the formation of a favorable solid electrolyte interphase (SEI) and resulted in enhanced cycling stability. This study reports the characterization of Na-metal anode surfaces cycled with these electrolytes containing different water concentrations (up to 5000 ppm). Morphological and spectroscopic characterization showed that water addition greatly influences the formation of the SEI and that ∼1000 ppm of water promoted the formation of an active and more uniform deposit, with larger quantities of SEI species (S, O, F, and N) present. Water addition to the electrolyte system is also proposed to promote the formation of a new complex between the FSI anions, water molecules, and sodium cations as components of the SEI. For both dry and wet (∼1000 ppm) electrolytes, the SEIs were mainly composed of NaF, metal oxide (i.e., Na2O), and the complex, suggested to be Na2[SO3-N-SO2F]·nH2O (n = 0-2). Postcycling SEM analysis of the Na-metal electrodes after extensive cycling (500 cycles, 1.0 mA·cm-2, 1.0 mA·.cm-2) was used to estimate the minimal average cycling efficiency (ACE), which was enhanced by water addition: up to ∼99% for the 1000 ppm cell compared to ∼98% for the dry cell. Two distinct deposit morphologies, a microporous and a compact layer deposit, were evident after extended cycling in the wet and dry electrolytes. The presence of both the microporous and compact layer deposits on Na-metal surfaces cycled with the wet electrolyte, along with the distinct chemistry and morphology of the SEI, all contributed to a more stable symmetric cell voltage profile and lower cell polarization. In contrast, a higher fraction of microporous deposits and the absence of compact layer formation in the dry electrolyte were associated with higher cell polarization potentials and the occurrence of dendrites.

The experiment was conducted at agronomy farm of Sher-e-Bangla Agricultural University, Dhaka from November 2017 to April 2018 to investigate the influence of weeding regimes on the performance of white maize varieties. The experiment comprised two varieties viz. YANGNUO-3000 and PSC-121, designated as V1 and V2 respectively combined with four weed control treatments viz. T0 = No weeding, T1 = One hand weeding at 60 DAS (days after sowing), T2 = two hand weeding at 40 DAS and 60 DAS and T3 = Weed free after 40 DAS. The experiment was laid out in RCBD (factorial) with three replications. PSC-121 showed the superior performance in terms of plant height, leaf number plant-1, number of grains cob-1 (468.75), 100 grains weight (35.0837 g), grain yield (8.28 t ha-1), stover yield (6.56 t ha-1) and harvest index (55.58%) over YANGNUO-3000. In the case of weed control treatments, the highest plant height, leaf number plant-1, number of grains cob-1 (464.54), 100 grains weight (37 g), grain yield (9.25 t ha-1) and stover yield (7.46 t ha-1) were reported from T3. All the parameters studied were found lowest with T0. However, in terms of interaction, no single interaction was superior to other alternatives. But in most of the cases V2T3 showed the highest values regarding the maximum plant height, leaf number plant-1, number of grains cob-1 (494.97) and 100 grains weight (38 g). V2T3 showed the highest grain yield (9.33 t ha-1), whereas, V1T0 showed the lowest grain yield (5.49 t ha-1). The lowest weed density and weed biomass (12.17 no. m-2 and 4.33 g·m-2) was recorded from T3. The highest weed control efficiency (94.38%) was also recorded from T3. In the case of variety V2 showed better performance in terms of weed density, weed biomass and WCE (46.32%).

An experiment was conducted during December, 2017 to May, 2018 at the Agronomy field of Sher-e-Bangla Agricultural University, Dhaka to evaluate the performance of white maize variety under different spacing and integrated fertilizer management. The experiment comprised two different factors; (1) two plant spacing viz. S1 (60 cm × 20 cm) and S2 (40 cm × 20 cm) and (2) four levels of integrated fertilizer application viz. T1: All chemical fertilizer (recommended dose), T2: maize straw compost +½ of recommended dose,T3: cowdung+½ of recommended dose and T4: vermicompost +½ of recommended dose. The experiment was set up in split plot design with three replications. Results revealed that both the individual and the interaction treatments had effect on different growth and yield parameters of white maize. In respect of the spacing effect, the wider spacing S1 showed higher plant height, number of leaves plant-1, cob length, cob circumference, number of grains cob-1, shelling percentage, 100 grains weight and harvest index where S2 showed higher grain yield. The integrated fertilizer had significant effect on different growth and yield parameters of white maize. In respect of the integrated fertilizer effect, the highest values in plant height, number of leaves plant-1, leaf area index and crop growth rate, cob length, cob circumference, number of grains cob-1, shelling percentage, 100 grains weight, grain yield, stover yield and biological yield were highest with T3 whereas, the lowest corresponding values were recorded from T2. Among the interaction treatments, higher seed yield was obtained with the interaction treatment S2T3 (10.01 t ha-1) while S1T2 showed significantly the lowest seed yield (5.27 t ha-1). The highest seed yield was mostly attributed to the number of grains per cob (328-433) and 100 seed weights (29.67-33.33 g).

SARS-CoV-2 is the causative agent behind the ongoing COVID-19 pandemic. This virus is a cumulative outcome of mutations, leading to frequent emergence of new variants and their subvariants. Some of them are a matter of high concern, while others are variants of interest for studying the mutational effect. The major five variants of concern (VOCs) are Alpha (B.1.1.7), Beta (B.1.315), Gamma (P.1), Delta (B.1.617.2), and Omicron (B.1.1.529.*/BA.*). Omicron itself has100 subvariants at present, among which BA.1 (21K), BA.2 (21L), BA.4 (22A), BA.5 (22B), and BA.2.12.1 (22C) are the dominant ones. Undoubtedly, these variants and sometimes their progeny subvariants have significant differences in their spike region that impart them the unique properties they harbor. But alongside, the mutations in their non-spike regions could also be responsible elements behind their characteristics, such as replication time, virulence, survival, host immune evasion, and such. There exists a probability that these mutations of non-spike proteins may also impart epistatic effects that are yet to be brought to light. The focus of this review encompasses the non-spike mutations of Omicron, especially in its widely circulating subvariants (BA.1, BA.2, BA.4, BA.5, and BA.2.12.1). The mutations such as in NSP3, NSP6, NSP13, M protein, ORF7b, and ORF9b are mentioned few of all, which might have led to the varying properties, including growth advantages, higher transmission rate, lower infectivity, and most importantly better host immune evasion through natural killer cell inactivation, autophagosome-lysosome fusion prevention, host protein synthesis disruption, and so on. This aspect of Omicron subvariants has not yet been explored. Further study of alteration of expression or interaction profile of these non-spike mutations bearing proteins, if present, can add a great deal of knowledge to the current understanding of the viral properties and thus effective prevention strategies.

The present work investigates the role of two types of carbon nanodots (CNDs) as novel sensitizers of TiO2 to create a visible-light driven photo-catalyst that is not only efficient for solar-driven pollution abatement, but also inexpensive, durable and environmentally-friendly. Two widely available green organic precursors, the Argentinean herb Mate and the Stevia plant have been selected as the carbogenic source to thermally induce the formation of different types of CNDs with different levels of N and P doping and tunable photoluminescence response in the UV–vis-near infrared (NIR) ranges. These CNDs have been successfully assembled with TiO2 to form heterogeneous photocatalysts that are highly active in the visible-light and NIR- driven photodegradation of 2,4-dichlorophenol (2,4-DCP), a persistent chlorinated organic compound present in numerous pesticide formulations.

Prime cities in developing countries, like Dhaka experience haphazard and intense horizontal densification. The livability of dense neighbourhoods needs to be investigated, particularly, the role of housing and planning in mitigating density problems and capitalizing the advantages of high-density living. This article argues that housing form and planned community facilities giving respect to socio-cultural practices can significantly influence Dhaka’s livability. Also, a wider definition of housing should be adopted to facilitate improvements in livability. As well, an integrated approach of residential planning is important in intensified housing development projects or planning for dense areas, encompassing housing standards, community facilities, public transport, open space provision and socio-cultural habits. This paper recommends the Bangladeshi Government to ensure enforcement of residential plans, to establish density zones in Dhaka’s main urban areas to guide spatial and transport develo...

Non-uniform metal deposition and dendrite formation in high density energy storage devices reduces the efficiency, safety, and life of batteries with metal anodes. Superconcentrated ionic liquid (IL) electrolytes (e.g. 1:1 IL:alkali ion) coupled with anode preconditioning at more negative potentials can completely mitigate these issues, and therefore revolutionize high density energy storage devices. However, the mechanisms by which very high salt concentration and preconditioning potential enable uniform metal deposition and prevent dendrite formation at the metal anode during cycling are poorly understood, and therefore not optimized. Here, we use atomic-force microscopy and molecular dynamics simulations to unravel the influence of these factors on the interface chemistry in a sodium electrolyte, demonstrating how a molten salt like structure at the electrode surface results in dendrite free metal cycling at higher rates. Such a structure will support the formation of a more favorable solid electrolyte interphase (SEI) accepted as being a critical factor in stable battery cycling. This new understanding will enable engineering of efficient anode electrodes by tuning interfacial nanostructure via salt concentration and high voltage preconditioning.

Non-uniform metal deposition and dendrite formation in high-density energy storage devices reduces the efficiency, safety and life of batteries with metal anodes. Superconcentrated ionic-liquid electrolytes (for example 1:1 ionic liquid:alkali ion) coupled with anode preconditioning at more negative potentials can completely mitigate these issues, and therefore revolutionize high-density energy storage devices. However, the mechanisms by which very high salt concentration and preconditioning potential enable uniform metal deposition and prevent dendrite formation at the metal anode during cycling are poorly understood, and therefore not optimized. Here, we use atomic force microscopy and molecular dynamics simulations to unravel the influence of these factors on the interface chemistry in a sodium electrolyte, demonstrating how a molten-salt-like structure at the electrode surface results in dendrite-free metal cycling at higher rates. Such a structure will support the formation of a more favourable solid electrolyte interphase, accepted as being a critical factor in stable battery cycling. This new understanding will enable engineering of efficient anode electrodes by tuning the interfacial nanostructure via salt concentration and high-voltage preconditioning. Non-uniform metal deposition and dendrite formation reduce the efficiency, safety and life of batteries with metal anodes. The influence of these factors in a sodium electrolyte now shows how a molten-salt-like structure at the electrode surface results in dendrite-free metal cycling at higher rates.

In this paper, we have made an investigation on a stellar model with Kramer’s Opacity and negligible abundance of heavy elements. We have determined the structure of a star with mass , i.e. the physical variables like pressure, density, temperature and luminosity at different interior points of the star. We have discussed about some equations of structure, mechanism of energy production in a star and energy transports in stellar interior in a star and then we have solved radiative envelope and convective core by the matching or fitting point method and Runge-Kutta method by C Programming language. In future, it will help us to know about the characteristics of new stars.

Luminescent carbon nanodots (CNDs) have been obtained by hydrothermal processing of ascorbic acid (AA) and ethanolamine (EN). The resulting N-doped carbon nanostructures exhibit interesting and tunable emission capabilities with a dual behavior as down-converters and more importantly, as up-converting quantum dots. Herein, we also evaluate the optical response of these CNDs to selectively generate highly reactive oxidative hydroxyls ( OH) upon irradiation with different light-emitting diodes (LEDs) in the visible–NIR range. Finally, the role of the N-doped CNDs as nano-sensitizers to maximize the solar light harvesting and expand the photo-catalytic response of a commonly used UV-active catalyst such as TiO2 was successfully tested in the degradation of an organo-chlorinated compound under visible light.

The effect of water on the properties of superconcentrated sodium salt solutions in ionic liquids (ILs) was investigated to design electrolytes for sodium battery applications with water as an additive. Water was added to a 50 mol % solution of NaFSI [FSI=bis(fluorosulfonyl)imide] in the ionic liquid N-methyl-N-propylpyrrolidinium bis(fluorosulfonyl)imide (C3 mpyrFSI). Although the thermal properties (e.g., glass transition temperature) showed little dependence on the water content, the viscosity and, in particular, the ionic conductivity were strongly affected. The Na|Na symmetrical cell cycling performance was strongly dependent on the applied current density as well as on the water content. At higher current densities (1.0 mA cm-2 ) the polarization profiles showed a water dependence, suggesting that water was actively involved in the formation of an improved solid electrolyte interface layer (SEI) for high-water-content samples (1000-5000 ppm), resulting in improved long-term cycling stability. The initial impedance of cells cycled at 1.0 mA cm-2 (measured after 20 cycles) was elevated after water addition, and large polarizations occured for the "wet" samples. However, with further cycling the wet cells began to exhibit lower polarization and improved stability compared to the "dry" sample. The Na|NaFePO4 cell cycling performance was also demonstrated with minimal effect on the cell capacity, further highlighting the negligible activity of water in these electrolyte systems. In fact, reduced cell polarization and a more clearly defined charge profile were evident after water addition. The work shown here suggests that water may be used as a convenient and inexpensive additive for superconcentrated sodium IL electrolytes for improved device performance.

Converting waste into biogas has the benefits of reducing emission to the atmosphere and adding energy to the society for improving livelihood of the people. An extensive amount of food waste is generated regularly from residential area, student hostels, restaurants, markets. Thus food waste can be a fruitful alternative for biogas production. Therefore, an experimental research work was commenced at the GEKH (Green Energy Knowledge Hub) laboratory of the department of Farm Power and Machinery, Bangladesh Agricultural University to analyze the potentiality of biogas production of different food wastes. Four ladies halls were selected for the study. An approximate amount of total food waste of these halls was estimated through survey and visual inspection. Furthermore, food wastes were collected from these halls for conducting this batch experiment for understanding gas production potential from the wastes. Food wastes such as various vegetable wastes like potato, cauliflower, cabbage, bean; chicken slaughter and fish waste were classified; wastes from the plates were selected for this study. The whole experiment was conducted in an incubator where all the substrates were mixed with a seeding inoculum (same volatile solid ratio) for 54 days retention time with three replications at 35˚C temperature. Total waste production from the four female student halls was 860 kg/day among which vegetable wastes was 40%, slaughter and fish wastes was 20% and wastes from peoples plate was 40%. It was found that slaughter and fish waste mixture and vegetable waste were more potential substrate in biogas production than other selected substrates respectively. The cumulative biogas production of slaughter and fish waste mixture and cumulative bio-methane potentiality of vegetable waste were found 256.13 ml/g VS and 45.17 ml/g VS, respectively. From the total wastes, about 11.68 m³/day methane can be produced for mixed type waste by which 44.16% natural gas consumption of four student halls can be substituted. [J Bangladesh Agril Univ 2020; 18(1.000): 138-144]

Traditional electrolytes currently used for Li-ion and Na-ion devices are not compatible with higher energy-density anodes required for next generation devices, such as Li metal and Na metal anodes. In addition, there is now a recognition that operation at elevated temperatures is desirable for some applications. Therefore, new electrolyte materials are currently actively being investigated for beyond Li-ion technologies. It has recently been shown that, by using an ultra-high concentration of lithium or sodium salt in an ionic liquid (or indeed some organic solvents),it is possible to achieve stable cycling of Li metal and Na metal anodes, often at high rates and current densities, and even in the presence of water. These electrolytes indicate a decoupling of the alkali metal ion dynamics from the bulk with tLi+ or tNa + transport numbers approaching or even exceeding 0.5. We will discuss the structure and transport in these superconcentrated IL systems and the importance of clustering and structural rearrangement in the transport mechanism of the alkali metal cation. It has also been demonstrated that polymerized ionic liquids, such as poly(diallyldimethylammonium) (PDADMA), with either TFSI or FSI counterions, are capable of dissolving even higher concentrations of lithium salt leading to highly conductive solid electrolytes. These materials have high tLi+ and improved mechanical properties and also enable stable Li metal cycling, thus offering exciting opportunities for all solid state lithium batteries. These materials will also be discussed in terms of their phase behavior, conductivity and electrochemical behavior.

Present energy demand is hard to sustain due to increasing energy consumption. Thus new energy storage and supply technologies are required which are reliable, safe, inexpensive and show high energy and power densities. Among various battery chemistries, Na based batteries have been identified as potential efficient stationary energy storage technologies. Electrolytes are an integral component of a sodium battery spatially ionic liquid based electrolytes have attracted great interest1. The use of additives during electrolyte preparation is often carried out to achieve better transport performance, tune the composition of the solid electrolyte interphase, SEI, and alter other characteristics1–3. Recently, electrolyte additives for Na batteries is an emerging area for researchers3 The effect of water on the properties of sodium salt solutions of ionic liquids (ILs) was investigated in order to design electrolytes for sodium battery applications using water as an additive. Water amounts ranging from 100 to 10000 ppm were added to a superconcentrated NaFSI salt (50 mol%) solution in the ionic liquid N-methyl-N-propylpyrrolidinium bis(fluorosulfonyl)imide (C3mpyrFSI)4. While the thermal properties (glass transition temperature) are little dependent on the water content, the viscosity and, in particular the ionic conductivity (fig1a), are strongly affected. Whereas addition of the NaFSI salt to the IL significantly increases viscosity with a concommitant decrease in conductivity, adding water up to 10000 ppm (0.99 wt%) remarkably restores the values close to those of the neat ionic liquid (i.e., reversing the detrimental effect of Na salt addition on conductivity). Na|Na symmetrical cell cycling performance is strongly dependent on the applied current density as well as on the water content (fig1b). At higher current densities (1.0 mAcm-2) the polarisation profiles show a water dependence suggesting that water is being actively involved in the formation of a solid electrolyte interphase (SEI) for high water content samples (1000 – 5000 ppm). The work shown here suggests that water may be a convenient and inexpensive additive in high concentrated ionic liquid electrolytes for sodium which can improve device performance. Reference: Armand, M., Endres, F., MacFarlane, D. R., Ohno, H. & Scrosati, B. Ionic-liquid materials for the electrochemical challenges of the future. Nat. Mater. 8, 621–9 (2009). Yan, Y. et al. Roles of Additives in the Trihexyl(tetradecyl) Phosphonium Chloride Ionic Liquid Electrolyte for Primary Mg-Air Cells. J. Electrochem. Soc. 161, A974–A980 (2014). Komaba, S. et al. Fluorinated ethylene carbonate as electrolyte additive for rechargeable Na batteries. ACS Appl. Mater. Interfaces 3, 4165–4168 (2011). Forsyth, M. et al. Novel Na+ Ion Diffusion Mechanism in Mixed Organic-Inorganic Ionic Liquid Electrolyte Leading to High Na+ Transference Number and Stable, High Rate Electrochemical Cycling of Sodium Cells. J. Phys. Chem. C 120, 4276–4286 (2016). Figure 1

Hypocrisy is the practice of engaging in the behavior or activity for which one critics the other. George Orwell’s ‘Shooting an Elephant’ is an essay where hypocrisy is exposed. Because in one side Orwell claims that imperialism is an evil thing and he hates it more bitterly and at the end of the story he establishes himself as an example of a genuine imperialist by performing his noble duty- that really carries his true identity as a hypocrite. It is an act of hypocrisy not heroics in a sense that he shows no courage to express the truth publicly and likes to impose it on the natives. As an agent of British imperialism Orwell shows the tendency of an act of hypocrite by wearing the musk of imperialism and finally unfolded it through the actions and his attitudes. So this paper is a modest attempt to show how hypocrisy is focused through the actions and the descriptions of the narrator who is bold enough in speaking the truth and exposing the lies. Actually the writer as an agent of the British Raj at first knows what he should do to the natives but he tries to show his innocence which becomes an issue here.

The competency of a locally available granular activated carbon (GAC) in removing color from textile wastewater was studied in a fluidized bed. The characteristics of the fluidized bed with different GAC particles were obtained. A reactive dye was used to prepare the colored water of different dye concentrations. The effects of the GAC particle size, velocity and initial concentration of the colored water on dye removal were investigated. Equilibrium adsorption isotherm and breakthrough curves were generated to determine adsorption characteristics of activated carbon as well as mass transfer coefficients of the fluidized bed. The results of these experiments showed that an increase in liquid velocity and a decrease in particle size increased the color removal. The experiments were also carried out with industrial effluent and the de-colorization achieved was satisfactory. The mass transfer coefficient calculated for the fluidized bed was very low, which suggests that the GAC used in the local industries, although less expensive, may not be economically viable for de-colorization of industrial effluent.