Blue carbon stock of the Bangladesh Sundarban mangroves: what could be the scenario after a century?

The total blue carbon stock of the Bangladesh Sundarban mangroves was evaluated and the probable future status after a century was predicted based on the recent trend of changes in the last 30 years and implementing a hybrid model of Markov Chain and Cellular automata. At present 36.24 Tg C and 54.95 Tg C are stored in the above-ground and below-ground compartments respectively resulting in total blue carbon stock of 91.19 Tg C. According to the prediction 15.88 Tg C would be lost from this region by the year 2115. The low saline species composition classes dominated mainly by Heritiera spp. accounts for the major portion of the carbon sock at present (45.60 Tg C), while the highly saline regions stores only 14.90 Tg C. The prediction shows that after a hundred years almost 22.42 Tg C would be lost from the low saline regions accompanied by an increase of 8.20 Tg C in the high saline regions dominated mainly by Excoecaria sp. and Avicennia spp. The net carbon loss would be due to both mangrove area loss (~ 510 km2) and change in species composition leading to 58.28 Tg of potential CO2 emission within the year 2115

Mixed leaf meal supplemented with exogenous enzyme and limiting amino acids can completely replace DORB (de-oiled rice bran) in the diet of

Various single leaf meal can substitute costly de-oiled rice bran (DORB) in farm made feed for carps. However, the use of mixed leaf meal (LM) in fish feed is not reported yet. Therefore, Vigna mungo, Ipomoea aquatica and Hygrophila spinosa leaf meals were blended in an equal proportion to prepare LM. DORB was the major energy source in control diet (C) and LM substituted 50% and 100% of DORB in LM20 and LM40 experimental diets, respectively. In addition, control diet (C), LM20 and LM40 diets were supplemented with limiting amino acids and exogenous carbohydrases and denoted as CE, LM20E and LM40E, respectively. Labeo rohita fingerlings were fed till satiation for 60 days. Fish fed with LM20E diet exhibited maximum growth rates and feed conversion (p 0.05). Amylase and aminotransferase activities were positively related with growth indices (p 0.05) while lower superoxide dismutase activities was observed in LM fed groups (p < 0.05). The present study concluded that LM up to 400 g kg–1 could be incorporated as complete DORB replacer in L. rohita diet, however, 200 g kg–1 LM supplemented with 0.98 g L-lysine kg–1 and 1 g exogenous enzyme kg–1 registered the best growth, nutrient utilization, feed conversion ratio, physio-metabolic responses and hematological status

Catalytic conversion of CO2 to biofuel (methanol) and downstream separation in membrane-integrated photoreactor system under suitable conditions

A heterogeneous photocatalyst has been developed using sono-chemical assisted sol-gel method by maintaining aweight ratio of 1:2:3 for hydrogen exfoliation graphene, titanium oxide andcopper sulphateand exhaustively characterized. Rigorous experimentations have been done using newly developed heterogeneous photocatalyst for efficient capturing and maximum conversion of carbon di oxide to methanol by mutual effects of governing conditions, like as catalyst dose, pH, CO2 flow rate and temperature. Optimization study has been carried out employing a statistical approach of response surface methodology which reveals the maximum methanol productivity and yield. Approximately, 134 g/Lh of productivity and 40 mg/gcatof yield were found after 3 h of illumination under UV in an annular type Pyrex reactor at an optimum catalyst dosage of 10 g/L, CO2 flow rate of 3 L/m, pH of 3, and process temperature of 50 °C. By the judicial integration of flat-sheet cross flow microfiltration membrane module for catalyst separation and recycle, a steady state permeate flux 145 L/m2h was achieved at an applied pressure of 3 bar and cross-flow feed rate of 700 L/h

Deposition of nanocrystalline CuS thin film from a single precursor: Structural, optical and electrical properties

Nanocrystalline CuS thin films were fabricated using a metal organic deposition technique taking Cu(SOCCH(3))(2)Lut(2) as the precursor. X-ray diffraction (XRD) technique, field emission scanning electron microscopy (FESEM), atomic force microscopy (AFM), UV-vis absorption spectroscopy, photoluminescence spectroscopy (PL) and Raman spectroscopic techniques were applied for characterization and found that the deposited CuS films were of `covellite' phase with an average particle size of 18 nm. Optical measurements showed significant amount of ``blue shift'' in the band gap energy. Hall measurements of the films showed p-type conduction nature with a carrier concentration in the range 10(12)-10(13) cm(-3)

Fabrication and Therapeutic Process of a Green Silver-Nanoparticle-Embedded Mucilage Microsphere for Pathogenic-Bacteria-Infected Second-Degree Burn and Excision Wounds

Multidrug-resistant bacteria are a serious problem in biomedical applications that decrease the wound healing process and increase the mortality rate. Therefore, in this study, we have prepared a green-synthesized silver-nanoparticle-encapsulated mucilage microsphere (HMMS@GSNP) from Hibiscus rosa sinensis leaves and applied it to pathogen-infected burn and excision wounds. Biophysical properties like size, polydispersity index, absorbance capacity, and drug release were measured by different techniques like field-emission scanning electron microscopy, dynamic light scattering, swelling ratio, etc. The strong antibacterial activity of a HMMS@GSNP microsphere was measured by minimum inhibitory concentration assay, minimum bactericidal concentration assay, and agar well diffusion methods. The HMMS@GSNP microsphere enhanced the cell viability, cell proliferation, migration, antioxidant, and antiinflammation activity compared to untreated GSNP and HMMS, as quantified by MTT assay, BrdU assay, scratch wound assay, reactive oxygen species scavenging assay, and Western blot analysis, respectively. In the in vivo experiment, we used a methicillin-resistant Staphylococcus aureus bacteria-infected, burn-and-excision-wound-created male BALB/c mice model. The HMMS@GSNP-treated burn-and-excision-wound-infected mice showed significant results compared to other groups (untreated, Silverex Ionic Gel, AgNO3, HMMS, and GSNP), and the mice tissues were utilized for bacteria count, immunoblot analysis, histological studies, and real-time polymerase chain reaction. Thus, the HMM@GSNP microsphere is an excellent therapeutic material that can be used as a topical agent for the management of chronic wound therapy

Conductive MoS₂ Quantum Dot/Polyaniline Aerogel for Enhanced Electrocatalytic Hydrogen Evolution and Photoresponse Properties

The low conductivity and poor active sites of MoS₂ sheet present a huge barrier for it is exploitation of catalytic applications in the hydrogen evolution reaction (HER). To alleviate this difficulty, we have synthesized MoS₂ quantum dots (QDs) having greater quantity of catalytic edge sites by breaking up the bulk MoS₂ sheet using the solvent exfoliation technique. The synthesized MoS₂ QDs are embedded into polyaniline (PANI)–<i>N</i>,<i>N</i>′-dibenzoyl-l-cystine (DBC) hydrogel matrix by in situ polymerization of aniline where DBC acts as a gelator, dopant, and cross-linker. The hybrid conducting aerogels (DBC-MoS₂-PANI) thus produced act as an efficient electrocatalyst showing lower HER overpotential in comparison to MoS₂ QDs. It exhibits an optimum overpotential value of 196 mV at 10 mA cm^–2, a favorable Tafel slope of 58 mV/dec, and an excellent cyclic stability. Also, DBC-MoS₂-PANI aerogel is used in photoresponding devices. The DBC-MoS₂-PANI hybrid aerogel exhibits a better photoresponse compared to the DBC-PANI aerogel and MoS₂ QDs upon white light illumination of 1 sun. The hybrid aerogel exhibits a maximum enhancement of photocurrent to the value of 3.95 mA at 2 V bias, and the time-dependent photoillumination shows much faster rise and decay of photocurrent compared to those of DBC-PANI aerogel and MoS₂ QDs