LED Tube Research Articles

Light spectrum affects growth, metabolite profile, and resistance against fungal phytopathogens of Solanum lycopersicum L. seedlings

Tomato is a widely cultivated and economically important crop worldwide. This study aimed to test the effect of light spectra used in indoor cultivation on the growth, biochemical profile, and resistance of Solanum lycopersicum ‘Bawole Serce’ seedlings against Alternaria alternata, Alternaria solani and Botrytis cinerea. During the phase of first leaf emergence, the seedlings were transferred to a semi-sterile growth room with a controlled environment (20°C, 18-h photoperiod, 50 μmol · m−2 · s−1 PPFD, 65% RH) for a 3-week cultivation period. Five light treatments differing in red/blue (R/B) light ratio were tested: I (LED tube; R/B 5.55), II (fluorescent tube; R/B 0.72), III (fluorescent tube; R/B 1.19), IV (LED panel; R/B 0.51), V (LED panel; R/B 0.20). The best parameters in terms of shoot length, shoot fresh and dry weights, and number of leaves were obtained in treatment I, in contrast to IV and V. Plants from treatments IV and V had the smallest leaf area, perimeter, vertical length, and horizontal width. As for the root system, the highest fresh weight, area, length of the longest root, total length, and the number of root tips and forks were found in treatments I and II. The least developed root systems were observed in IV and V. The greatest chlorophyll, carotenoids and anthocyanins accumulation was enhanced by treatment II. Treatments I−III stimulated the biosynthesis of phenolic compounds. The highest superoxide dismutase activity was detected in plants from treatments I and II. As for A. alternata and A. solani, the level of disease symptoms was significantly higher for treatments IV and V than for I-III. The highest/lowest level of B. cinerea infection was found in treatments II/I, respectively. The least susceptible to infection by all tested pathogens were leaves from treatment I. Light spectrum composition is of practical importance for tomato seedling production.

Assessment of lighting system in library room of E11 building, Universitas Negeri Semarang

Lighting is primary factors for visual comfort in the library. The library of Universitas Negeri Semarang had the illuminance of 97 – 672 lux. Based on SNI 6197-2011, the library must have a minimum illuminance of 300 lux. This study aims to assess the quality of lighting, design the layout and lighting system using Dialux evo 9.2 software. This research was expected for the best layout design to support the lighting system to follow SNI 6197-2011. This research used the library of E11 Building, Universitas Negeri Semarang with dimension of 8.6 m x 5.7 m x 3.4 m. This research was carried out by redesigning the layout of the furniture, replacing the type of lamp and armature and calculating the efficiency electricity cost. The results declared that the quality of lighting in the library using TL-D 36W did not achieve SNI 6197-2011. Redesigning of furniture layout and replacing of TL-D with LED tube are solutions to achieve the minimum illuminance. In addition, replacing TL-D with LED Tube can save electricity costs ranging from 64% – 69% per year.

Simulasi Pencahayaan Buatan untuk Ruang Kelas dengan Tipe Armature TL LED dan Bohlam LED

Classroom light intensity is one of the essential factors in the learning process. Several factors affect light intensity in the classroom, i.e., determination of classroom design, position of objects in the classroom, window design, shading devices, type of lamp, and type of lamp armature. The research aims to determine the effect of armature lamp type. The results of this research are expected to increase the efficiency of electricity costs and use the classroom optimal lighting system according to Indonesian National Standard (SNI). Two types of lamp armature used in this research i.e. LED tube armature and LED bulb armature. This research used E11-210 classroom in E11 Building of Electrical Engineering Department, Universitas Negeri Semarang with the size of 12m x 9m x 3.5m. Simulation in this research used Dialux Evo 9 software. The results of observations and simulations show that E11-210 classroom had not followed SNI yet, in 350 lux. Based on simulation results, it shows that using LED tube armature and LED bulb armature will get light intensity of E11-210 classroom that follow SNI 6197:2011. Simulation results show that the use of LED tube armature (Powerbalance Gen2 RC463B) in E11-210 classroom will increase efficiency of electricity costs by 27.81%. Meanwhile, the use of LED bulb armature (Luxspace Ace Acccent RS750B) in E11-210 classroom will increase efficiency of electricity costs by 33.96%.

Heat load due to LED lighting of in-door strawberry plantation

This paper investigates heat load due to LED lighting of in-door strawberry plantation. A double-chamber experimental room was designed and constructed at Chiang Mai University, Thailand. There are 180 strawberry plants inside the inner experimental room. Air temperature and moisture of the room can be adjusted using an air conditioner. LED tubes was used to supply light for photosynthesis of the strawberry plant. The air temperature, air moisture, and condensed water from evaporator were measured. Using energy balance and mass balance equations, it was found that, during the use of LED lighting, the condensed water from the experimental room was increased. Calculated heat load of the room were also increased. Approximately 60% of the heat load is from condensation when there is no lighting load. While providing lighting from LED, heat loads from LED and condensation can be almost 100% of total heat load. Increased condensation heat load is the result of evapotranspiration by strawberry plant.

Porphyrin-based thick-film bulk-heterojunction solar cells for indoor light harvesting

A thick-film (∼200 nm) porphyrin-based P1:PC71BM BHJ solar cell achieves an optimized PCE of 18.2%, under a 300 lux illumination of a 3000 K LED tube.

Application of Wireless Power Transmission Led Lighting System in Propagation of Chrysanthemum and Strawberry

ABSTRACT Wireless power transmission has been recently used to charge batteries in portable devices. This is the first study to combine this technology with light-emitting diodes (WPT-LP) for plant tissue culture application. We also present the comparison of the in vitro growth of chrysanthemum and strawberry plantlets under the new LED lighting system; LED - Uni-Pack (LP) system; LED tube and fluorescent light (FL). The results showed that fresh weight (1.42 g), dry weight (118.67 mg), plant height (5.68 cm), leaf area (3.59 cm2) and chlorophyll content (47.9 μg g-1) of chrysanthemum plantlets under the WPT-LP system were higher than those under FL and LED tube. Similar results were also recorded on the strawberry plantlets. Our results suggested that utilizing WPT-LP system saves the culture space considerably compared with the conventional downward lighting system with fluorescent lamps. The results also indicated that the subsequent growth and development of chrysanthemum and strawberry plantlets derived from WPT-LP system were either equal to or better than those from LP system under LED tube or FL.

Growth and Flowering Responses of Petunia to Various Artificial Light Sources with Different Light Qualities

This study was carried out to investigate the effect of artificial light sources with different light qualities on the growth and flowering characteristics of a herbaceous long-day plant, Petunia × hybrida Hort. Seedlings of petunia cultivar ‘Madness Rose’ were potted, acclimated for one week, and grown in a phytotron equipped with tube- and bulb-type fluorescent lamps (FL tube and bulb), tube-type white light-emitting diodes (LED tube), halogen lamps (HL), metal halide lamps (MH), and high pressure sodium lamps (HPS) for 10 weeks. The temperature, photoperiod, and photosynthetic photon flux density (PPFD) in the phytotron were 22 ± 2℃, 16 h, and 25 ±2 μmolㆍm -2 ㆍs -1 , respectively. Light sources combined with HL promoted stem elongation, and plant height and internode length decreased with increasing red to far-red (R:FR) ratio. FL tube + LED tube, HPS, and FL tube promoted branching, whereas plants grown under light sources combined with HL did not have any branches. Days to flowering (from longest to shortest) occurred as follows: FL tube + HL > FL tube + HL > MH > HPS = FL tube + FL bulb > FL tube + LED tube > LED tube > FL tube, indicating that reducing the R:FR ratio of the light sources promoted flowering. Only 20% of plants grown under an FL tube flowered, whereas under all other treatments, 100% of plants flowered. At 10 weeks after treatment, plants grown under HPS and MH had (cumulatively) 12 open flowers, and those grown under FL tube + FL bulb, LED tube, FL tube + LED tube, and HPS treatment had approximately seven flower buds. These results suggest that light sources with low R:FR ratios promote flowering and stem elongation in petunia, but they reduce its ornamental value due to overgrowth and poor branching.

Improving the quality of cold merchandising unit: an application of quality function deployment

Quality of hot and cold merchandisers are an important tool if food is to be held and displayed properly to entice consumers to buy and to drive food to go sale. In this paper, QFD tool used to translate the voice of the customer to technical aspects in order to set an action plan to improve the double door cold merchandising unit. It was found that eliminating the moisture from the door glass, sliding door mechanism durability, and light system durability are the most important requirements, while increasing insulation efficiency, anti moisture solutions, using LED tubes, and electricity fluctuation solution, was found to be the most important technical descriptors. HOQ presented in this work contributed in prioritising company's R&D directions. Further research efforts will be continuing the balance steps of QFD process, other future work suggestions could be using QFD tool to assess voice of the customers for other products.

Comparison of LED vs CFL tungsten bulb of internal wiring system of electrical installation

We try our best to initiate in order to reduce the total load of inter wiring system of our campus by replacing the LED bulbs & LED tube light in place of CFL & Filament bulbs. Our aim is to provide a permanent solution of tripping problem as well as to reduce the power consumption. Here we are comparing the load estimation of overall internal wiring system before & after replacement by this investigation. We also present a comparative practical approach to improve the energy efficiency by using new technology.

Blue Light Hazard and Risk Group Classification of 8 W LED Tubes, Replacing Fluorescent Tubes, through Optical Radiation Measurements

In this paper, the authors discuss the results of a measurement survey of artificial optical radiation emitted by 8 W LED tubes suitable for the substitution of 18 W fluorescent lamps used for general lighting. For both types of lamps, three different color temperatures were chosen, 3000 K, 4000 K, and 6000 K. These measurements were performed to evaluate the photobiological safety of the sources. The radiance and irradiance values have been measured in a wide range of wavelengths (180–3000 nm). The measurement results obtained for the LED tubes have been compared to those of similar measurements obtained for fluorescent lamps. The analysis has been focused on the range of wavelengths 300–700 nm, the blue light range, which turned out to be defining for the risk groups of the lamps. This classification is a function of the maximum permissible exposure time as indicated in the European Standard EN 62471 on the photobiological safety of lamps and lamp systems.

Techno-Economic Analysis of LED Lighting: A Case Study in UTeM's Faculty Building

Abstract This paper examines the feasibility of adopting LED lamp in replacing the conventional fluorescent lamp. Analysis and comparison have been carried out on the two lighting systems in terms of electrical and photometrical performance. A case study on UTeM's building has also been presented, which focuses on the economic evaluation. In addition, various lighting energy saving strategies have been proposed. The economic benefits of the respective energy saving measures have been successfully quantified. The study suggests that LED tubes has great potential to replace fluorescent lamps, mainly driven by the cost savings.

Thermal Analysis of High-Power LED Tube Lamp

Heat dissipation of high-power LED lamps has become a key technology to LED package due to the improvement of the LED output power. A detailed simulation of temperature distribution of three chips high-power LED tube lamp was made by finite element method. Based on the consistency of the LED lamp experimental and simulation results, the analyses of the effect of thermal conductivities of PCB, thermal grease, heat sink, convection coefficients and the length of the lamp on the junction temperature were made, which provide an effective reference for the thermal design.