The small tea growers (STGs) constitute a significant part of the tea industries in several tea producing countries in the world. STGs constitute 70 percent of the tea cultivation by area and 60 percent of the total tea production by volume. However, low profitability, limited marketing options, inefficient supply chain, and dependency on the large tea estates for processing has emerged as a serious threat to the sustainability of the STGs. Mostly, the STG’s role in the tea supply chain is confined merely to the cultivation of the tea leaves. In India too, the STGs are confronted with similar challenges. India is the second-largest tea producer in the world with about 50 percent of the total tea production coming from the STGs. Notably, considering the economic and environmental benefits, some of the STGs have taken to organic cultivation of tea. Further, some of them who adopted organic cultivation also took to processing and marketing of made tea like hand-made green tea, black tea, and other specialty products by themselves. This study seeks to understand and analyze the role of organic cultivation in providing market linkages and the development of value chain(s) for the STGs. The study was conducted in the state of Assam, which is recognized worldwide for the presence of one of the oldest and the largest tea industries. It used a qualitative value chain approach to analyze the current situation of the STGs involved in the production of organic tea. The study mostly relied on primary data collected from the various actors of the emerging tea value chain through a semi-structured interview schedule, in-depth interviews, and focused group discussions. The processing and marketing of tea by the organic STGs in Assam has indeed led to the development of tea value chain(s) for the STGs. Adoption of sustainable agriculture systems like organic cultivation has opened up new opportunities for the STGs to earn from tea processing and marketing by themselves. Although such developments are in a very initial stage, understandings from the present scenario add to the literature on the development of value chain and market linkages for the smallholders in the tea sector with implications for other agricultural sectors as well. Encouraging the STGs to produce orthodox tea products, especially green and black tea varieties, in larger quantity by mobilizing them for collective actions is likely to locate them in the global tea value chain. The study suggests such suitable policy measures to bring about transformations in the tea sub-sector. Appropriate institutional changes to develop sustainable tea value chain(s) controlled by the STGs would be the key to impart overall sustainability to the industry. Such developments are likely to help the tea industry in Assam and other tea producing regions to meet the changing consumer aspirations and sustain global competition.

Organic-inorganic hybrid perovskite nanocrystals have attracted a lot of attention owing to their excellent optical properties such as high absorption coefficient, high diffusion length, and photoluminescence quantum yield in optoelectronic applications. Despite the many advantages of optoelectronic materials, understanding on how these materials interact with their environments is still lacking. In this study, the fluorescence properties of methylammonium lead bromide (CH3NH3PbBr3, MAPbBr3) nanoparticles are investigated for the detection of volatile organic compounds (VOCs) and aliphatic amines (monoethylamine, diethylamine, and trimethylamine). In particular, colloidal MAPbBr3 nanoparticles demonstrate a high selectivity in response to diethylamine, in which a significant photoluminescence (PL) quenching (~ 100%) is observed at a concentration of 100 ppm. This selectivity to the aliphatic amines may originate from the relative size of the amine molecules that must be accommodated in the perovskite crystals structure with a narrow range of tolerance factor. Sensitive PL response of MAPbBr3 nanocrystals suggests a simple and effective strategy for colorimetric and fluorescence sensing of aliphatic amines in organic solution phase.

n-Nonane, 1¸2¸4-trimethylbenzene (124-TMB), toluene, total xylene (TXYL), isopropyl alcohol (IPA), and methyl ethyl alcohol (MEK) are major volatile organic compounds (VOCs) emitted from printing industries. The absorption amount of a single VOC per unit weight of silicone oil was as follows in the order of 189.5 g/kg-silicone oil for n-nonane, 91.7 g/kg-silicone oil for 124-TMB, and 60.1 g/kg-silicone oil for TXYL. Although hydrophobic VOCs were more absorbed in silicone oil than hydrophilic VOCs such as IPA and MEK, IPA and MEK, which had log Kow values of 1 or less, also were absorbed more than 26.0 g/kg-silicone oil. In two and three mixed VOCs of n-nonane, 124-TMB, and toluene, the absorption amount of each in silicon oil was less than that of single a VOC. The total absorption amount of two mixed VOCs ranged from 47.9 g to 138.7 g/kg-silicone oil, and the total absorption amount of three mixed VOCs was 65.8 g/kg-silicone oil. These results suggest that silicone oil is a promising pretreatment solution capable of absorbing high concentrations of VOCs that are intermittently emitted from printing industries. The absorption information of VOCs obtained in this study can be used as the design parameters of a damping device for the pretreatment of VOCs.

본 논문에서는 유연/인쇄 전자 기술을 활용해 고성능의 유기물 반도체 기반 트랜지스터를 개발하고, 이를 통해 인공지능용 반도체 및 폴리모픽 전자회로에 응용하기 위해 공액구조 고분자 반도체 소재의 광파 어닐링 방법에 따른 특성 향상 효과를 연구하였다. 일반적으로 열처리를 위해 가장 많이 활용되는 핫플레이트의 경우 반도체 소자 특성의 균일도 문제와 높은 온도 및 열-용량으로 인한 플라스틱 기판 사용의 제한, 긴 어닐링 시간 등의 문제로 인해 실제 산업에서 활용하는데 어려움이 있다. 이를 해결하기 위해 광파를 활용한 효과적인 유기물 반도체 필름의 열처리 공정을 개발함으로써 Roll-to-Roll 방식의 고속/대면적 인쇄 공정에 적합한 열처리 방법과 반도체 층 전체의 높은 결정화도 유도를 통한 성능 향상과 소자 균일도 개선을 위한 방법을 개발하였다.

In this study, partially dry transfer is investigated to solve the problem of fully dry transfer. Partially dry transfer is a method in which multiple layers of graphene are dry-transferred over a wet-transferred graphene layer. At a wavelength of 550 nm, the transmittance of the partially dry-transferred graphene is seen to be about 3% higher for each layer than that of the fully dry-transferred graphene. Furthermore, the sheet resistance of the partially drytransferred graphene is relatively lower than that of the fully dry-transferred graphene, with the minimum sheet resistance being 179 Ω/sq. In addition, the fully dry-transferred graphene is easily damaged during the solution process, so that the performance of the organic photovoltaics (OPV) does not occur. In contrast, the best efficiency achievable for OPV using the partially dry-transferred graphene is 2.37% for 4 layers.