Effects of Display and Ambient Illuminance on Visual Comfort for Reading on a Mobile Device

A psychophysical experiment was carried out to investigate visual comfort when reading on three OPPO Find X3s displays at three luminance levels (100, 250 and 500 cd/m2) at five illuminance levels (0, 10, 100, 500 and 1000 lx). Twenty young observers evaluated visual comfort using a 6-category points method. The results showed that observers felt most comfortable at the illuminance of 500 lx or display luminance of 500 cd/m2. There was an interaction between ambient illuminance and display luminance. High ambient light and display brightness levels provide a more pleasant visual experience. In low ambient light, however, the lower the brightness level, the more comfortable it is to see. Regarding the influence of background colour on visual comfort, the observers felt more comfortable having a grey background than white or black colour. When at dim illuminance, the background colour would have a great influence on visual comfort for negative contrast conditions, but when at higher illuminance, different background lightness levels had a great impact on visual comfort for positive contrast conditions. The above findings are very similar to the display luminance levels of 100 and 250 cd/m2.

Perbandingan kinerja beberapa lampu LED cerdas

ABSTRAK Beberapa waktu terakhir terdapat sebuah teknlogi baru dari lampu LED, yaitu lampu LED cerdas. Sudah cukup banyak penelitian tentang perbandingan performa lampu LED dengan lampu jenis lainnya, namun belum ada penelitian tentang perbandingan kinerja antar merk lampu LED cerdas. Berdasarkan hal tersebut maka dilakukan analisis pengaruh warna cahaya dan tingkat kecerahan terhadap kuat penerangan lampu serta pengaruh tingkat kecerahan terhadap penggunaan energi, daya, faktor daya, tegangan, dan arus pada sembilan merek lampu dengan daya yang sama. Didapatkan hasil lampu Merek A mempunyai unjuk kerja yang lebih baik jika dibandingkan lampu merk lain. Hal ini dikarenakan lampu Merek A mempunyai nilai kuat penerangan yang paling baik di antara merk lampu lainnya pada kedua warna cahaya. Selain itu kuat penerangan lampu Merek A tidak terlalu terpengaruh dengan penurunan tingkat kecerahan. Namun, penggunaan energi listrik pada lampu merek A relatif konstan meskipun tingkat kecerahan diturunkan. ABSTRACT Recently, there has been a new technology for LED bulb, namely smart LED bulb. There have been many studies on comparing the performance of LED bulb with conventional bulb, but there has been no research on performance comparisons between brands of smart LED lamps. Based on this, an analysis of the effect of light color and brightness level on bulb illumination and the effect of brightness level on the use of energy, power, power factor, voltage, and current on nine brands of bulbs with the same power was carried out. The results obtained that A bulb have better performance when compared to other bulbs. This is because A bulbs have the best illumination value among other bulbs in both light colors. In addition, the illumination of the A bulb is not too affected by the decrease in the brightness level. However, the use of electrical energy in A bulb is relatively constant even though the brightness level is lowered.

Pengukuran Kecerahan Langit Arah Zenit di Medan dan Serdang Bedagai Menggunakan Sky Quality Meter

Light pollution is a worldwide problem that affects fewer stars that can be seen at night. This study aims to measure the brightness of the sky in the zenith direction to minimize the effect of light pollution in observing celestial bodies. The research used the observation method of sky brightness level with SQM. Measurement of sky brightness was carried out in two places, namely in Medan and Serdang Bedagai. The SQM is mounted in a zenith direction and set to retrieve data every two seconds. Observations were made on November 10-13, 2018, during the new moon phase. The average value of sky brightness obtained in Medan is 18.05 mpsas and the NELM value is 4.00. Based on the Bortle scale, Medan is included in the ninth class area, namely the inner-city sky. Meanwhile, the average value of sky brightness obtained in Serdang Bedagai is 19.69 mpsas and the NELM value is 5.26. Based on the Bortle scale, Serdang Bedagai belongs to the sixth class area, namely bright suburban sky.

Efisiensi Pewarnaan Batik Tulis dengan Waterglass Menggunakan Roll Saving Pada Kelompok Pengrajin Batik Desa Tampo Kecamatan Cluring Kabupaten Banyuwangi

Batik is a typical Indonesian cloth. Almost all regions have their own batik peculiarities as well as Banyuwangi. From the beginning of the emergence of Banyuwangi batik, several motives have emerged that have philosophical meanings. The development of Banyuwangi batik is increasingly rapid, as evidenced by the increasing number of batik craftsmen. This proves that the typical Banyuwangi batik has a selling value that is in demand by many people. However, the production of the batik craftsmen in Banyuwangi cannot be maximized due to the limited skill of using waterglass which is done manually. So that it has not been able to meet market demand optimally. This is felt by the craftsmen in the Tampo village, Cluring sub-district. Tampo is a batik village in the cluring area because of the many batik craftsmen who produce batik with their own uniqueness. As a solution to the problems faced by batik najikha as one of the batik craftsmen in Tampo, they collaborate in conducting waterglass usage skills training. Empowerment of tampo written batik craftsmen focuses on Najikha's problems, namely; 1) Use of waterglass which is still wasteful; 2) The color of the written batik is not consistent, the brightness level is not the same; 3) The need for color lock technology and tools; 4) It is necessary to transfer the coloring technology using waterglass to the Najikha group; 5) The need for training and assistance to market Banyuwangi written batik nationally; 6) The Najikha group does not yet have a written batik catalog; 7) The absence of good bookkeeping. The PKM team conducts training for craftsmen with results; 1) creation of a roll saving tool; 2) 85% of Najikha's employees are able to use the roll saving tool well; 3) 85% of the color of written batik has increased in quality, brightness and durability; 4) 75% increase in marketing by the two batik Najikha; 5) both Najikhas have batik catalogs; 6) batik Najikha has simple bookkeeping through exel; 7) A significant increase in sales turnover by 65%. Methods and stages in the application of technology: starting from the stage of the situation analysis, the identification of the problem, the use of ineffective and inefficient waterglass. The results of the PKM in the form of a roll saving tool were given to Najikha batik, who then helped market the product by creating a Salem-written batik catalog (web and social media).

Karakteristik Enkapsulat Teh Instan Daun Kenikir (Cosmos caudatus Kunth.) pada Perlakuan Penambahan Emulsifier Tween 80

The aims of research were to know the effect of addition emulsifier tween 80 on the making of Cosmos caudatus Kunth. instant tea, and to determine the addition of the best tween 80 emulsifier to the Cosmos caudatus Kunth. instant tea. This research used a simple randomized block design, wich the concentration of tween 80 as the factor. The concentration of tween 80 used in this research are 0%, 0.5%, 1%, 1.5%, 2%, 2.5%. The data obtained were analyzed by analysis of variance and then processed by the Tukey test. The results showed that the concentration of tween 80 influenced the yield, solubility, total flavonoids, brightness level, redness level, yellowish level, and texture organoleptic tests which included stickiness, dryness and smoothness. The best treatment based on physicochemistry was obtained by adding 1% concentration of tween 80, with a yield value at 11.08 %, solubility at 96.77%, total flavonoids at 9.1041 mg QE/g, the level of brightness (L*) at 36.49, the level of redness (a*) at 19.36, and the level of yellowish (b*) at 30.63. Based on the results of the organoleptic test, respondendts chose treatment without the addition of tween 80, with a stickiness texture value at 4.20 (not sticky),, dryness at 4.60 (dry), and smoothness at 4.75 (smooth). Keywords : Cosmos caudatus Kunth. leaves, instant tea, encapsulation, tween 80

Karakteristrik Enkapsulat Pewarna dari Ekstrak Daun Pepaya (Carica papaya L.) pada Perlakuan Perbandingan Gelatin dan Maltodekstrin

Papaya leaves can be used as a green dye because it contains chlorophyll. Chlorophyll compounds as a green coloring are obtained by extraction and stored in the form of encapsulation powder. This study has two purposes, (i) to know the effect of the gelatin and maltodextrin encapsulants ratio on the encapsulates characteristics of papaya leaf coloring extract, and (ii) to determine the encapsulates comparison treatment of the best gelatin and maltodextrin in producing the characteristic encapsulate extract of papaya leaf coloring. Experiments in this study were using a randomized block design with one treatment, namely the ratio of gelatin and maltodextrin consisting of 7 levels, namely, (1:0), (0:1) (1:1), (1:1.5), (1:2), (1:2.5), (1:3). The results showed that the ratio of gelatin-maltodextrin was highly significant (P<0.05) on yield, total chlorophyll content, solubility, brightness level, redness level (a*), yellowish level (b*) and no effect (P>0.05) on water content. The treatment of gelatin and maltodextrin (1:3) ratio was the best treatment to produce encapsulate sea lettuce extract with yield of 35.27 %, water content of 6.13%, total chlorophyll content of 1192.69 ppm, solubility of 79.12%, brightness level (L*) 39.39, redness level (a*) 16.95 and yellowish level (b*) 14.84. Keywords : papaya leaf extract, gelatin, maltodextrin, encapsulation

Effect of Spirulina Flour on Changes of Color Intensity in Angelfish (Pterophyllum scalare) Strain Three Color

Ornamental fish is a fishery commodity that has promising business opportunities. Ornamental fish will have a high selling value if they have bright and brilliant colors. The advantage of ornamental fish is in the intensity of the color on its body. This study aims to analyze the levels of Spirulina added in feed which can increase the color intensity of the Angelfish juvenille. The method used was an experimental method Completely Randomized Design, consisting of five treatments and four replications. The parameter observed was an increase in color on the head of the fish and analyzed using Kruskal-Wallis.The results showed that giving 3% spirulina flour in commercial feed could provide the best color improvement for angelfish with an increase in color value by 3, and if discontinued addition of spirulina flour can reduce the brightness level of the angelfish.

Physical Characteristics of Edible Film from Breadfruit Peel using Xylitol as Plasticizer

Breadfruit peel derived from peeling waste from processed products made from breadfruit. Currently, breadfruit is only used for its flesh, while the peel of breadfruit is usually discarded or used as animal feed. Breadfruit peel flour has a fiber content of 2.65% and starch of 39.56%. The starch content in this breadfruit peel starch can be used as an ingre-dient for the manufacture of environmentally friendly biodegradable plastic, namely edible film. Edible film is a thin layer used as a food wrapper. This research purposes are to iden-tify the characteristics of edible film made from breadfruit regarding their texture and color. The physical characteristics produced are that the edible film has a texture that is flexible, slippery, and easy to tear, while the more composition of the material added, the brightness level of the edible film will increase.

Pengaruh Ukuran Partikel dan Waktu Maserasi terhadap Ekstrak Virgin Coconut Oil (VCO) Kunyit (Curcuma longa L.) sebagai Pewarna Alami

Turmeric contains a carotenoid that can be used as a natural dye by extracting a carotenoid compound using VCO. This research is meant to know the effect of particle size and time of maseration to VCO turmeric extract as natural dye and to determine the impact the best particle size and time of maseration to produce VCO turmeric extract as natural dye. This experiment used a random group design with two factors. First factor is particle size which is composed of 40, 60, and 80 mesh. Second factor in time of maseration which is composed of 4, 6 dan 8 hours. Data is analyzed with variance analysis and followed by Tukey test. Research shows interactions between particle size and time of maseration have very real impact on carotenoid total, betacarotene level, and the reddish level. Interagency interaction have real impact on brightness level but have no real impact on yield and yellowish level. Best treatment to produce VCO turmeric extract as natural dye are with 40 mesh for particle size and 6 hours for time of maseration with characteristic of yield 73,26±0,15 percent, carotenoid total in the amount of 205,78±0,40 µmol/L, betacarotene level in the amount of 9,99±0,07 mg/g, brightness level 43,06±1,02, reddish level 15,31±0,95, and yellowish level 42,33±0,61. Keywords : Turmeric, VCO, extraction, carotenoid, natural dye