PELATIHAN TEKNIK PEWARNAAN BAGI PENGRAJIN TENUN DESA NEKMESE KECAMATAN AMARASI SELATAN

ABSTRAKKegiatan pengabdian kepada masyarakat ini bertujuan memperkenalkan dan melatih para pengrajin untuk menggunakan teknik pewarnaan celup dengan zat warna napthol, yang dapat menjaga warna tetap awet dan kualitas hasil tenun lebih baik. Kain Tenun NTT memiliki banyak motif yang sangat menarik dan sudah terkenal tidak hanya di Indonesia tetapi juga di Luar Negeri. Untuk mempertahankan kualitas kain tenun, maka pengrajin harus memperhatikan teknik pewarnaan. Selama ini pengrajin tenun Desa Nekmese menggunakan wantex sebagai bahan untuk pewarna, tetapi kelemahannya warna kain tenun akan luntur jika dicuci. Dengan kegiatan pengabdian ini pengrajin mendapat tambahan pengetahuan teknik pewarnaan dengan menggunakan zat warna napthol yang dapat menjaga kualitas warna kain tenun. Kegiatan pengabdian ini dilakukan dengan menggunakan pendekatan pelatihan dan praktek langsung, sehingga peserta bisa memahami setiap prosesnya serta hasil pengabdian peserta sudah mampu mengalikasikan teknik pewarnaan celup dengan zat warna napthol. Kata kunci: teknik pewarnaan; pengrajin tenun; zat warna napthol. ABSTRACTThis Community Service activity aims to introduce and train craftsmen to use the dyeing technique with naphthol dyes, which can keep the color durable and the quality of the weaving better. NTT Woven Fabrics have many very interesting motifs and are well known not only in Indonesia but also abroad. To maintain the quality of woven fabrics, craftsmen must pay attention to coloring techniques. So far, the weaving craftsmen of Nekmese Village use wantex as a dye, but the weakness is that the color of the woven fabric will fade when washed. With this service activity, craftsmen get additional knowledge of coloring techniques using naphthol dyes that can maintain the color quality of woven fabrics. This service activity is carried out using a training approach and direct practice so that participants can understand each process and the results of the service participants can apply dyeing techniques with naphthol dyes. Keywords: coloring technique; weavers; naphthol dye.

Using CaCO3-doped package to improve correlated color temperature uniformity of white light-emitting diodes

<span>The white light-emitting diode (WLED) has been the most advance lighting method currently, however, the fabrication process of this configuration still has drawbacks which negatively affect its color quality. This research was conducted to provide a method for WLED’s lighting output enhancement. Since CaCO₃ particles are excellent for thermal stability enhancement, especially when being combined with an adhesive substance, we decided to integrate CO₃ particles into resin matrix such as melamine formaldehyde (MF) and investigate their influences on the optical properties, including color uniformity and lumen output, of the WLED. The results showed that CaCO3 and MF resin are beneficial to the light scattering efficiency, which results in higher luminous flux and chromatic quality for WLED packages. In addition to that, the appropriate amounts of MF resin and CaCO₃ for reaching the best lumen efficiency and color quality are figured out at 1% and 10%, respectively. Moreover, another advantage of using MF resin and CaCO₃ for fabricating WLEDs is cost effectiveness. Hence, it has turned out that CaCO₃ and MF resins can be potential materials for next high-quality WLED generations.</span>

The effect green YF3:ER3+,YB3+ phosphor on luminous flux and color quality of multi-chip white light-emitting diodes

The purpose of this paper is to demonstrate the advantages of the green phosphor YF₃:Er³⁺,Yb³⁺combined with multi-chip package to the enhancement of lighting efficiency of modern WLEDs. In an effort to improve the quality of WLEDs and create a new generation of lighting device, green phosphor YF₃:Er³⁺,Yb³⁺is added into the phosphor compounding of the WLED package to improve the color quality and lighting capacity. Through experiments, WLEDs with YF₃:Er³⁺,Yb³⁺green phosphor has shown improved results in lighting performance specifically in color homogeneity and light output of WLEDs in the ACCT range from 5600-7000 K. However, the color quality scale (CQS) declines gradually. Therefore, if the appropriate concentration and size of YF₃:Er³⁺,Yb³⁺ are determined, the performance of MCW-LEDs will be enhanced and become more stable.

Cranberry (Vaccinium macrocarpon) Juice Precipitate Pigmentation Is Mainly Polymeric Colors and Has Limited Impact on Soluble Anthocyanin Loss

Anthocyanins degrade in fruit juice during storage, reducing juice color quality and depleting the health-promoting components of juice. Common water-soluble products of anthocyanins’ chemical degradation are known, but little is known about the contribution of the insoluble phase to loss processes. Cranberry juice and isolated anthocyanins were incubated at 50 °C for up to 10 days to determine polyphenol profiles and degradation rates. Anthocyanin-proanthocyanidin heteropolymers were analyzed via Matrix Assisted Laser Desorption/Ionization (MALDI)- Time of Flight (TOF) Mass Spectrometry (MS). Formation of soluble protocatechuic acid accounted for 260 ± 10% and insoluble materials for 80 ± 20% of lost soluble cyanidin-glycosides in juice, over-representations plausibly due to quercetin and (epi)catechin in cranberry juice and not observed in the values of 70 ± 20% and 16 ± 6% in the purified anthocyanin system. Loss processes of soluble peonidin-glycosides were better accounted for, where 31 ± 2% were attributable to soluble vanillic acid formation and 3 ± 1% to insoluble materials in cranberry juice and 35 ± 5% to vanillic acid formation and 1.6 ± 0.8% to insoluble materials in the purified anthocyanin system. Free anthocyanins were below quantifiable levels in precipitate, implying most anthocyanins in precipitate were polymeric colors (PCs). PCs in the precipitate included cyanidin- and peonidin-hexosides and -pentosides covalently bonded to procyanidins. Therefore, formation of cranberry juice precipitate does not deplete a large portion of soluble anthocyanins; rather, the precipitate’s pigmentation results from PCs that are also present in the soluble phase.

Improvement of double-layer phosphor structure WLEDS in color homogeneity and luminous flux

The concept of the analysis is to put a CaAl2O4:Mn2+ green phosphor layer on top of the YAG:Ce3+ yellow phosphor layer. After that, find the added CaAl2O4:Mn2+ concentration appropriate for the highest luminous flux (LF) and color homogeneity (CH). In this analysis, five equivalent WLEDs were applied but with distinct color temperatures, including 5600 K - 8500 K. The findings showed that CaAl2O4:Mn2+ brings great benefits to increase not only the luminous flux but also the color homogeneity. Especially, the higher the CaAl2O4:Mn2+ concentration, the more the luminous flux released by WLEDs, owing to the risen content of the light of green in WLEDs. Nevertheless, as the CaAl2O4:Mn2+ concentration raised significantly, a small reduction in the color rendering metric (CRI) and color quality scale (CQS) occurred. This is supported by simulation and calculation according to the theory of Monte Carlo. The paper results are the crucial contribution to the manufacture of WLEDs with better optical performance and color homogeneity of remote phosphor configurations.

Enhancing light scattering effect of white LEDs with ZnO nanostructures

Pc-LEDs, the lighting method that blends blue LED light with yellow light from phosphor to discharge white radiation, is one of the most advance known for high lumen output. However, pc-LEDs has inferior due to angular CCT deviation, which prevent pc-LEDs from reaching better performance. As a result, this research is conducted to address the need of pc-LEDs development by introducing a configuration doped with ZnO nanoparticles. The finite-difference time-domain (FDTD) method and the phosphor layer containing ZnO were applied in the experiments. The effect of ZnO-filled on the performance of color quality pc-LEDs is confirmed through calculated results. In particular, the uniformity of scattered light is improved with the presence of ZnO. In addition, ZnO particles also minimize the deviation of color temperature and enhance the color quality. Although there is a small decline in lumen output to achieve better color temperature uniformity, however, with suitable concentrations such as 0.25% N-ZnO, 0.25% S-ZnO, and 0. 75% R-ZnO, the decline is acceptable. The research on ZnO pc-LEDs demonstrates that this affordable and simple configuration can improve lighting properties and create other directions to enhance white light