Dokra works in Bikna: The pinnacle of excellence of the ancient crafts.

The name Dokra or Dhokra was formally used to indicate a group of nomadic people scattered over Bengal, Orissa and Madhya Pradesh in India and now is applied generally to a variety of shaped and decorated products created by the ‘lost wax’ process. One of such important group of families are located in Bankura at Bikna village ,West Bengal .The traditional theme of these metal sculptures include images of Hindu God and goddess along with figures of people, elephants etc and also include various ornaments and decorated things. This technique was traced far as ancient Chola Dynasty to make various Chola bronzes statues. First an image was made of wax or other medium like dhuna .This was covered with clay and allow drying, a tiny hole was made on it. When it heated the molten brass replaced the original impression as the wax subjected to vaporize due to heat. Villagers involve in these craft making process they neither have any agricultural land nor any other source of income. It becomes difficult to lead their lives depending totally on these product materials as they hardly get reliable prices and hold the demands throughout the year. A case study made on it tries to promote the product materials along with the artisans’ lives to draw government and other organizational attention to enlightening their craftsmanship, enhance souvenir industry and give better way of life to the people involved in it.

Enhanced Magnetic Properties of Mn-Ni Codoped Cobalt Ferrite Nanoparticles Corroborated with Microstructural Analysis

Magnetic nanoparticles including ferrites are very potential candidates for its versatile application in the fields of engineering, bio medicine and electronics. Here we report the enhancement of magnetic properties of Mn-Ni co-doped cobalt ferrite nanoparticles which have been synthesized using coprecipitation technique. TEM study depicts the single phase nanocrystalline ferrite formation. Cation distribution between the tetrahedral and octahedral sites changes due to doping which is responsible for enhancement of magnetic properties. An exhaustive Rietveld analysis confirmed the rearrangement of the cations between the tetrahedral and octahedral sites. Also the results suggests strengthening of A-B and A-A interactions while weakening of B-B interaction for doped sample. ``Law of Approach'' technique is found to be useful and utilized to extract the detail of magnetic parameters like anisotropy constant, anisotropy field, coercivity

Carbon-based adsorbents from naturally available Bermuda grasses : removal of TDS and arsenic ions

In the present study, we have reported the synthesis of nano porous carbon material (GC) by the thermal treatment of the commonly available Bermuda grasses, and metal oxides doped bio-compatible polymer chitosan-GC based porous cross-linked composites (CHGCCZ) as adsorbent materials for the removal of total dissolved solids (TDS) and efficient removal of arsenic (As(V)) ions from aqueous medium, respectively. The synthesized adsorbents have been characterized by FTIR, PXRD, FESEM, TGA, and the systematic investigations have shown that the incorporation of GCs into cross-linked matrix makes them porous, more resistant to degradation, and suitable adsorption matrix for the toxic As(V) removal. The presence of As(V) ions is quantified by Inductively Coupled Plasma Optical Emission Spectroscopy (ICP-OES) measurements. The amount of TDS and arsenic concentration was reduced to the minimum value of 103 ppm (average value∼119 ppm) from 414 ppm and 7.7 ppm from very high concentration of 10.15 ppm, respectively. The recyclability test has also been performed after regeneration of the CHGCCZ and the initial findings has been found to be promising. Therefore, we have systematically investigated the efficacy of TDS removal by GCs and As(V) adsorption properties of metal oxide doped cross-linked CHGCCZ composite from the aqueous system and demonstrated the regeneration process for CHGCCZ in our study

Er3+-Doped Nanoengineered Yttria-Stabilized Zirconia Alumino-Silicate Fiber for Efficient CW and Mode-Locked Laser Operation

We report on the development of efficient continuous wave (CW) and mode-locked ring fiber lasers utilizing an Er3+-doped nanoengineered yttria-stabilized zirconia alumino (YSZA)-silicate fiber as the gain element. With the proper design of the material composition, the YSZA fiber host presents superior features to eliminate the Er3+ cluster effects and enhance the radiative emission over commercial silica fibers, thus significantly increasing the fiber laser efficiencies. Through cavity analysis and optimization, we successfully demonstrate a 975-nm pumped single-mode Er3+-doped CW YSZA-silicate fiber laser with a slope efficiency of 43%, which is corresponding to the quantum efficiency of 69%. Because of the special dispersion property of the Er3+-doped YSZA-silicate fiber, we are able to build a stable soliton mode-locked 1565-nm fiber laser with 3.2-nJ pulse energy, 644-fs pulsewidth, and 4.96-kW peak power

Satb2 acts as a gatekeeper for major developmental transitions during early vertebrate embryogenesis

Zygotic genome activation (ZGA) initiates regionalized transcription underlying distinct cellular identities. ZGA is dependent upon dynamic chromatin architecture sculpted by conserved DNA-binding proteins. However, the direct mechanistic link between the onset of ZGA and the tissue-specific transcription remains unclear. Here, we have addressed the involvement of chromatin organizer Satb2 in orchestrating both processes during zebrafish embryogenesis. Integrative analysis of transcriptome, genome-wide occupancy and chromatin accessibility reveals contrasting molecular activities of maternally deposited and zygotically synthesized Satb2. Maternal Satb2 prevents premature transcription of zygotic genes by influencing the interplay between the pluripotency factors. By contrast, zygotic Satb2 activates transcription of the same group of genes during neural crest development and organogenesis. Thus, our comparative analysis of maternal versus zygotic function of Satb2 underscores how these antithetical activities are temporally coordinated and functionally implemented highlighting the evolutionary implications of the biphasic and bimodal regulation of landmark developmental transitions by a single determinant

Enhanced Erbium-Zirconia-Yttria-Aluminum Co-Doped Fiber Amplifier

An efficient optical amplifier is demonstrated using an improved erbium-zirconia-yttria-aluminum co-doped fiber (Zr-EDF) as the gain medium. With a combination of both Zr and Al, we could achieve a high erbium doping concentration with an absorption loss of around 80.0 dB/m at 980 nm. The Zr-EDF is obtained from a fiber preform, which is fabricated in a ternary glass host, i.e., a zirconia-yttria-aluminum co-doped silica fiber, using a modified chemical vapor deposition, in conjunction with a solution doping process. At the optimum length of 1 m, the Zr-EDF amplifier produces a flat gain of 38 dB within a wavelength region between 1530 and 1565 nm with a gain variation of less than 3 dB when the input signal power and 980 nm pump power are fixed at -30 dBm and 130 mW, respectively. The highest gain of 40.3 dB is obtained at 1560 nm wavelength. Compared with the previous Zr-EDF amplifier, the proposed Zr-EDFA shows improved gain, particularly at longer wavelengths. The gain is enhanced by about 15.8 dB at a wavelength of 1560 nm for an input signal of -30 dBm

Sub 100 NS TM Gain-Switched Fiber Laser Pumped by Rectangular Pulse Er: Yb Fiber Laser and Effect on Tissue Ablation

A nano-second mode-locked Er: Yb fiber laser has been employed to generate gain-switched pulses of sub-100 ns duration from a thulium fiber laser cavity with a wavelength near water absorption peak. Potential application in tissue ablation surgery is under study

Palladium(ii)-catalyzed stereoselective synthesis of C-glycosides from glycals with diaryliodonium salts

An efficient palladium(ii) mediated C-glycosylation of glycals with diaryliodonium salts is described, providing a new strategy for the synthesis of 2,3-dideoxy C-aryl glycosides with excellent stereoselectivity. The C-glycosylation of a diverse range of glycals, including d-glucal, d-galactal, d-allal, l-rhamnal, l-fucal, l-arabinal, d-maltal, and d-lactal, occurred effectively and the corresponding C-glycosides were obtained in moderate to good yields. This protocol is commended as a significant addition to the field of carbohydrate chemistry due to the rich functional group compatibility, broad range of substrate scope and exceptional α-stereoselectivity.Ministry of Education (MOE)Nanyang Technological UniversityNational Research Foundation (NRF)We thank Nanyang Technological University (RG120/18) and the Ministry of Education (MOE 2013-T3-1-002) and National Research Foundation (NRF2016NRF-NSFC002-005), Singapore, for their financial support

Fabrication of CR: Yagdoped Silica Optical Fiber Using Modified Powder in Tube Technique

Fabrication of Cr-YAG doped silica optical fiber suitable for tunable laser source using a modified powder in tube technique is reported for the first time. Initial performance along with its optical and material characterization is also presented