Light Bulb Research Articles

Enhanced flame-retardant phase change materials with good shape stability for thermal management

Phase change materials (PCMs) have become pivotal components in many fields such as energy storage, thermal management, and photothermal conversion. However, challenges including leakage, flammability, and low thermal conductivity have impeded their broad application. In this work, a cross-linked solid-solid PCM (SPEG) using polyethylene glycol (PEG) and styrene-maleic anhydride copolymer (SMA) was synthesized. To enhance flame retardancy and thermal conductivity, black phosphorus (BP) and expandable graphite (EG) were introduced into the PCM matrix, yielding the target product (SPEG-BP/EG PCM) with enhanced properties. The analysis demonstrated that the SPEG-BP/EG sample with the ratio BP/EG of 1:1 (SPEG-BP/EG-1) exhibited a notable decrease in peak heat release rate and total heat release by 55.2 % and 13.2 %, respectively, compared to the SPEG sample. Moreover, thermal conductivity was improved from 0.18 W m−1 K−1 (SPEG) to 0.59 W m−1 K−1 for SPEG-BP/EG-1. The inclusion of SMA in crosslinking facilitated the transition of PEG's phase change behavior from solid-liquid to solid-solid, maintaining an enthalpy efficiency of 64.0 %. SPEG-BP/EG-1 exhibited excellent dimensional stability and cycling performance in open heating/cooling cycle tests, remaining chemically stable even after 60 heating/cooling cycles, as confirmed by DSC analysis. Furthermore, thermal management performance was evaluated using an LED light bulb, revealing a notable reduction of 9.4 °C in the maximal working temperature facilitated by SPEG-BP/EG PCM. This work presented a comprehensive strategy to mitigate the challenges of flammability, low thermal conductivity, and leakage associated with conventional PCM (PEG), thereby having great potential in practical applications in thermal management.

Effect of the Addition of an Ultraviolet B Light Bulb for 6 Months to the Enclosure of Client-Owned Cockatiels (Nymphicus hollandicus) on Serum 25-Hydroxyvitamin D Concentrations

BackgroundThe objective of this study was to determine the effects of ultraviolet B (UVB) radiation on the serum concentration of 25-hydroxyvitamin D [25(OH)D] in pet cockatiels (Nymphicus hollandicus) living in their home environments. MethodsThirty client-owned cockatiels were allocated to an intervention group, consisting of exposure to a commercial coil fluorescent bulb, or a control group, with no exposure to supplemental lighting. Blood samples were collected at baseline (Day 0) and 6 months after simple randomization for measurement of 25(OH)D (Day 180). A linear mixed model was used to determine if serum 25(OH)D concentrations were influenced by time, group, age, or sex. ResultsAt baseline, median 25(OH)D concentration for the whole study population was 13nmol/L (range, 0.0-15.0nmol/L). At the end of the study, median 25(OH)D concentration for the whole study population was 6.5 nmol/L (0.0-15.0nmol/L), for the UVB group was 3 nmol/L (0.0-8.0nmol/L) and for the control group was 7.5nmol/L (6.0-11.0nmol/L). There was a statistically significant 50% reduction in 25(OH)D concentrations from the baseline to the final sampling period for the overall population, but no differences by group, age, or sex. Conclusion and clinical relevanceThe addition of a UVB bulb for 6 months to the enclosures of cockatiels did not increase their serum 25(OH)D concentrations. There was an unexplained decrease in both groups when comparing Day 0 to the Day 180 sampling period. The 50% attenuation in the UVB lighting group, although not statistically significant, may be clinically relevant and deserves further investigation.

Development of HPTLC method for simultaneous determination of quercetin and kaempferol in leaf extract of Hibiscus mutabilis

The aim of this study was to develop and validate a densitometric High-Performance Thin-Layer Chromatography (HPTLC) method for the simultaneous quantification of quercetin (Q) and kaempferol (K) in Hibiscus mutabilis leaf extracts. The analyses were performed on silica gel 60 F254 plates using a mobile phase composed of toluene, formic acid, and ethyl acetate (6:0.4:4, v/v/v). Detection was carried out at a wavelength of 272 nm using a deuterium and tungsten light source. The method exhibited excellent linearity over the concentration range of 100–600 ng/spot for quercetin and 500–3000 ng/spot for kaempferol, with determination coefficients (r2) of 0.9989 and 0.9973, respectively. The method showed no interferences from the plant matrix. The relative standard deviation (RSD) values for intra- and inter-day precision were less than 2% for both flavonoids. Recovery rates ranged from 97.69% to 99.20% for quercetin and from 89.91% to 95.87% for kaempferol. The limits of detection (LOD) were 190.23 ng/spot for quercetin and 187.23 ng/spot for kaempferol, while the limits of quantification (LOQ) were 570.10 ng/spot for quercetin and 566.12 ng/spot for kaempferol. This validated HPTLC method is reliable, precise, and accurate, making it suitable for the quality control of Hibiscus mutabilis leaf extracts. The study’s findings can be broadly applied to the quality control of herbal products, pharmacological research, and the development of nutraceuticals. The method’s ability to provide rapid and accurate quantification makes it an invaluable tool for researchers across various disciplines.

Flexible BTO piezoelectric generator fabricated by hydrothermal method with the assistance of lignocellulose and carbon nanomaterials

It is of great significance to develop piezoelectric composites with mechanical flexibility and high electromechanical coupling characteristics for the collection and conversion of mechanical energy. In this work, a barium titanate (BTO) based piezoelectric composite was prepared by hydrothermal synthesis and high-temperature carbonization with the assistance of cellulose nanofibers (CNF), graphene oxide (GO) and carboxylated carbon nanotubes (C-CNT). C-CNT, GO and CNF can provide growth sites for BTO, but compared with C-CNT, CNF and GO have stronger interaction with BTO, which can improve the compatibility between BTO and CNF/polyvinylidene fluoride (PVDF) matrix. The tensile strength of the composite membrane prepared by GO-CNF-BTO treated at 1100 °C can reach 23.36 ± 8.30 MPa. After further hot pressing and polarization treatment, its longitudinal piezoelectric coefficient (d33) reaches 9.8 ± 2.6 pC·N−1. Correspondingly, the open-circuit voltage (VOC) and short-circuit current (ISC) increases to 11.64 V and 824 nA, respectively. In addition, the assembled piezoelectric generator (PEG) can charge for small commercial capacitors, as well as light small bulbs and electronic screens. It also has good piezoelectric output stability and sensing performance, which can effectively convert the mechanical energy from human motion into electrical energy. This work provides a reference for the performance improvement of flexible piezoelectric devices.

(Invited) Next-Generation Photonic Source Based on Lateral GaAs/AlgaAs Heterostructure Devices

Quantum communications and remote sensing protocols rely on preparing individual quanta of light, or photons, as carriers of quantum information. While it is easy to generate many-photon classical states of light (e.g., a light bulb or a laser), it is challenging to generate single quanta or pairs of entangled quanta on-demand. Yet, only in this latter regime can the fundamentally quantum nature of light be exploited to achieve performance exceeding classical bounds.We are developing a single-photon source based on combining a one-parameter single electron pump (Figure 1a,b) – an electrically controlled, on-demand, high-fidelity emitter of single electrons [1] – with a lateral p-n junction [2] (Figure 1c,d) in which injected single electrons recombine with holes to produce single photons. These devices are realized in undoped GaAs/AlGaAs heterostructures and designed to be ambipolar. Such a quantum light source could lead to a paradigm shift in metrology, providing a quantum redefinition of two of the seven SI base units, the ampere and the candela. It is also possible in principle to realize scalable source arrays on a single chip. I will discuss progress towards realizing and characterizing these sources, including work on optimizing collection efficiency and Purcell enhancement using a lateral distributed Bragg reflector in a concentric ring geometry. Beyond fundamental studies, the proposed photon source will find practical use in quantum communications protocols (QKD), where it can offer fast data transmission rates, and quantum sensing with LiDAR, where it could outperform laser-based systems in the few-photon regime for low-power, stealth applications.[1] B. Buonacorsi et al, “Non-adiabatic single-electron pumps in a dopant-free GaAs/AlGaAs 2DEG”, Appl. Phys. Lett. 119, 114001 (2021).[2] L. Tian et al, “Stable electroluminescence in ambipolar dopant-free lateral p-n junctions”, Appl. Phys. Lett. 123, 061102 (2023). Figure 1

‘Now you’ve said it, it’s like a big light bulb!’: enacting post observation feedback suggestions

Teaching observations have become a ubiquitous feature of teacher education programmes, development schemes and assessment regimes. Whilst the processes and procedures of classroom observation are well documented, the feedback which follows teaching observations has been given less attention. Most research into teaching observations focuses on eliciting teachers’ perspectives on their experiences of being observed. In contrast, we examine two aspects vital to teacher development and enhanced teaching practice: (1) post observation feedback talk; (2) teachers’ enactment of feedback following the feedback session. This article argues that examining feedback talk and how talk may influence enactment can help both observers and teachers maximise the effectiveness of teaching observations. We focus on suggestions, a common way of helping teachers to develop and improve. We analyse empirical examples of authentic post observation feedback talk to explore how suggestions are made and responded to, identifying features of suggestions which prompt teacher understanding and enactment. Analysis enables us to provide observers with concrete advice on how to make suggestions, thus showing the practical affordances and methodological warrant of analysing feedback talk.

LED-based standard source providing CIE standard illuminant A for replacing incandescent standard lamps

The calibration scheme for illuminance meters using incandescent standard lamps have long served the industry. However, phasing out of incandescent standard lamps presents difficulties for maintaining calibration schemes. The National Metrology Institutes have received strong addresses for an alternative light source. To address this, an LED-based standard source providing CIE standard illuminant A (Illuminant A standard LED) was developed. The developed standard LED realized an CIE standard illuminant A spectrum using a customized LED package. The spectral distribution mismatch index according to CIE251:2023, was 2.5 %. The aging characteristic after post-assembly was approximately 0.2 % – 0.1 % after 100 h operation, which is superior that of traditional standard lamps. Moreover, the standard LED can be used with actual calibration schemes, and calibrated illuminance meters with sufficient measurement uncertainty for practical use. Illuminant A standard LED have great potential to replace incandescent standard lamps.

Tungsten Wire—From Lamp Filaments to Reinforcement Fibers for Composites in Fusion Reactors

The use of drawn tungsten wire marked a breakthrough in electric lighting which led to a significant advancement in human society and technology. Nowadays, thermal light sources using tungsten filaments are being more and more replaced by semiconductor‐based light‐emitting diodes (LEDs). Despite the lower visibility of incandescent lamps in everyday life, new markets and applications for drawn tungsten wires are opening up, which makes this complex material a highly‐studied subject. One of these applications is the use of heavily drawn tungsten wires as high‐performance reinforcement fibers for new composites that can withstand the extreme environment present in a nuclear fusion reactor. The main advantage of tungsten wires for this class of composites is their ductility and high strength. It can be used to increase the high‐temperature strength of copper‐based heat sink materials as well as the fracture toughness of bulk tungsten considered for the use of highly loaded reactor wall components. These new applications for tungsten wire has also given new impetus to the study of their fundamental properties.

Light bulbs have energy ratings - so why can't AI chatbots?

Light bulbs have energy ratings - so why can't AI chatbots?

Three-terminal high-output triboelectric nanogenerator to achieve alternating current/direct current collaborative output by coupling three-dimensional porous structure, triboelectrification and corona discharge

Nowadays, the comprehensive consideration of output performance, durability, and industrial environmental recycling has been the focus of triboelectric nanogenerator (TENG) research in recent years. Herein, the melamine formaldehyde (MF) foam with the feature of three-dimensional porous structure, soft contact and eco-friendly is used to design a novel three-terminal high-output TENG (TH-TENG) to efficiently harvest rotating mechanical energy based on the coupling of electrostatic induction, triboelectrification and corona discharge. The simplified sliding TENG model has been demonstrated to have excellent electrical output of 532.81 μA m−2, with the outstanding resistance to heat and humidity of the output for maintaining 95.1 % and 82.1 % under the condition of 40 ℃ and 60 % RH, 20 ℃ and 80 % RH after 100 k cycles, respectively. Furthermore, the TH-TENG achieves efficient collaborative output of DC and AC through persistent directional movement and reciprocating movement with alternant connection of electrodes, where the upper-sided and lower-sided TENGs achieve DC with power density of 3.54 and 4.97 W m−3 Hz−1, and middle-sided TENG achieves AC with power density of 0.66 W m−3 Hz−1, respectively. The TH-TENG can drive 2540 LEDs and 8 incandescent lamps, and continuously power 36 hygrothermographs in parallel for smart farm. This work has enriched charge density enhancement strategy through the industrial recyclable MF foam.

Hybrid dual-mode high-output triboelectric nanogenerator for achieving alternating current/direct current collaborative output

The large-scale practical application of triboelectric nanogenerators (TENGs) mainly depends on the limitations of output performance. On the basis of previous theory, this paper proposes a comprehensive strategy on the coupling of triboelectrification, corona discharge, volume effect, and space volume utilization of charge capture to enhance TENGs’ output. Thereby, a hybrid dual-mode high-output TENG (HDH-TENG) is proposed to efficiently harvest natural mechanical energy through a rotation-driven sliding-TENG (RS-TENG) and a magnetic-driven contact-separation TENG (MC-TENG). The simplified sliding-TENG with the combination of PU foam and vertical-radial electrodes achieves AC/DC collaborative output with charge density of 173.3 and 175.2 µC m−2, respectively. The simplified contact-separation TENG with the PU foam achieves AC output with charge density of 108.8 µC m−2. Furthermore, the integrated RS-TENG and MC-TENG achieve efficient collaborative output of DC with power density of 6.4 W m−2 Hz−1 and AC with power density of 128.6 mW m−2 Hz−1 through persistent directional sliding and contact separation, respectively, where a record-high constant current density output reached 1.9 mA m−2 Hz−1. The HDH-TENG can drive 6575 LEDs and 12 incandescent lamps, and continuously and stably power 52 hygrothermographs. This work further provides a new strategy for charge density enhancement of TENGs.

Hypersensitivity of Intrinsically Photosensitive Retinal Ganglion Cells in Migraine Induces Cortical Spreading Depression.

Migraine is a complex disorder characterized by episodes of moderate-to-severe, often unilateral headaches and generally accompanied by nausea, vomiting, and increased sensitivity to light (photophobia), sound (phonophobia), and smell (hyperosmia). Photophobia is considered the most bothersome symptom of migraine attacks. Although the underlying mechanism remains unclear, the intrinsically photosensitive retinal ganglion cells (ipRGCs) are considered to be involved in photophobia associated with migraine. In this study, we investigated the association between the sensitivity of ipRGCs and migraines and cortical spreading depression (CSD), which may trigger migraine attacks. The pupillary responses closely associated with the function of ipRGCs in patients with migraine who were irradiated with lights were evaluated. Blue (486 nm) light irradiation elicited a response from ipRGCs; however, red light (560 nm) had no such effect. Melanopsin, a photosensitive protein, phototransduces in ipRGCs following blue light stimulation. Hypersensitivity of ipRGCs was observed in patients with migraine. CSD was more easily induced with blue light than with incandescent light using a mouse CSD model. Moreover, CSD was suppressed, even in the presence of blue light, after injecting opsinamide, a melanopsin inhibitor. The hypersensitivity of ipRGCs in patients with migraine may induce CSD, resulting in migraine attacks.

Exploring electroacoustic conversion in a standing-wave thermo-acoustic generator: An experimental study

Thermoacoustic generators (TAGs) present an attractive solution for converting low-grade thermal energy into useable electrical power. Despite their relatively modest fabrication, TAGs face significant efficiency challenges that impede their broader adoption. Current research efforts in thermoacoustics are primarily focused on overcoming these limitations. A critical factor influencing TAG efficiency is the design of the acoustic-to-electric (ATE) device. This component plays a vital role in converting the acoustic energy generated within the thermoacoustic engine (TAE) into electricity. Despite its importance, the impact of ATE design on overall TAG performance has often been overlooked in previous studies. This research aims to address this gap by investigating how different ATE configurations influence the efficiency of power conversion within thermoacoustic systems. Specifically, this study delves into the potential of electromagnetic devices: linear alternators and loudspeakers, as ATE converters in a Standing Wave Thermoacoustic Generator (SWTAG) framework using air at atmospheric conditions. Firstly, a comparative analysis was conducted between two types of linear alternators—moving magnet and moving coil and tested with different magnet types (rare earth and ferrie anisotropic) to evaluate their impact on voltage generation. Secondly, the influence of various factors on energy conversion using loudspeakers was investigated, including loudspeaker type (paper cone vs. polypropylene cone), housing geometry (diameter and length), housing material (galvanized steel vs. PVC), open versus closed ATE housing design and utilizing dual loudspeakers. The generated electricity was utilized to power a light bulb. Linear alternators resultsMoving coil configuration outperformed the moving magnet design due to its lighter weight. Rare earth disc magnets generated higher voltage outputs compared to ferrie anisotropic magnets. The moving coil configuration achieved a maximum voltage output of 454 mV, while the moving magnet design reached a maximum of 312 mV. Both linear alternator configurations displayed low overall efficiencies. This is likely due to a mismatch between the magnet and coil diameters, leading to inefficiencies in capturing the generated magnetic field. Loudspeakers resultsPaper cone loudspeakers demonstrated superior performance due to their greater displacement capability. The Saknyo-Paper cone loudspeaker configuration achieved a voltage output of 4.11 V. Optimal voltage generation was achieved when the loudspeaker diameter matched the ATE device housing diameter. Galvanized steel housing offered better performance than PVC housing due to reduced vibration losses. The voltage outputs for the galvanized steel and PVC configurations were 4.11 V and 2.21 V, respectively. Closing the loudspeaker housing resulted in decreased voltage output due to wave interference. The voltage outputs for the galvanized steel and PVC configurations were 3.33 V and 1.62 V, respectively. Dual loudspeakers significantly enhanced voltage generation compared to a single loudspeaker. The maximum voltage recorded for the dual loudspeaker configuration was 6.5 V.The developed thermoacoustic generator achieved an output voltage exceeding the target of 6 V and thermal-to-electric efficiency of 3.42 % with an output electric power of 10.56 W, surpassing previous air-powered TAGs operating at atmospheric conditions. The generator successfully illuminated a light bulb, demonstrating its ability to generate useable electricity. This study provides valuable insights into optimizing the design of acoustic-to-electric conversion devices in TAGs. The findings highlight the importance of factors such as material selection, housing geometry, and magnet type for maximizing energy conversion efficiency.

Comprehensive Modeling of High‐Performance All‐Inorganic Cs2TiBr6‐Based Perovskite Solar Cells

The perovskites are desirable materials for photovoltaic and other renewable green energy technologies. Lead‐based perovskite solar cells (PSC) have recently gained considerable attention due to the abrupt rise in power conversion efficiency, but lead's well‐known toxicity prevents its large‐scale commercialization. One compelling option is Cs2TiBr6, which offers a nontoxic alternative. Herein, the electronic and optical characteristics of Cs2TiBr6 absorber material using density functional theory employing the WIEN2K tool are investigated. The energy band structure of Cs2TiBr6 shows an indirect bandgap of 2.2 eV. Additionally, optical properties are calculated, and the suitability of this material as an absorber for indoor and outdoor photovoltaic devices is investigated. The Cs2TiBr6 material has a peak absorption coefficient of 39.57 × 104 cm−1 and optical conductivity of 1.98 × 1015s−1, demonstrating its suitability as an absorber material. After that, a PSC is modeled using SCAPS‐1D by using the computed parameters. The performance of the modeled perovskite is enhanced by optimization of various parameters, resulting in the achievement of a high‐performance Cs2TiBr6‐based PSC, boasting a power conversion efficiency of 19.9% for air mass AM1.5 G spectra and power conversion efficiency of 16.76% for light emitting diode and 17.18% for incandescent light for indoor light conditions.

A spectrophotometric analysis of extracted water-soluble phenolic metabolites of lichens

Main conclusionRainwater most probably constitutes a relatively effective solvent for lichen substances in nature which have the potential to provide for human and environmental needs in the future.The aims were (i) to test the hypothesis on the potential solubility of lichen phenolic compounds using rainwater under conditions that partly reflect the natural environment and (ii) to propose new and effective methods for the water extraction of lichen substances. The results of spectrophotometric analyses of total phenolic metabolites in rainwater-based extracts from epigeic and epiphytic lichens, employing the Folin–Ciocalteu (F.–C.) method, are presented. The water solvent was tested at three pH levels: natural, 3, and 9. Extraction methods were undertaken from two perspectives: the partial imitation of natural environmental conditions and the potential use of extraction for economic purposes. From an ecological perspective, room-temperature water extraction (‘cold’ method) was used for 10-, 60-, and 120-min extraction periods. A variant of water extraction at analogous time intervals was an ‘insolation’ with a 100W light bulb to simulate the heat energy of the sun. For economic purposes, the water extraction method used the Soxhlet apparatus and its modified version, the ‘tea-extraction’ method (‘hot’ ones). The results showed that those extractions without an external heat source were almost ineffective, but insolation over 60- and 120-min periods proved to be more effective. Both tested ‘hot’ methods also proved to be effective, especially the ‘tea-extraction’ one. Generally, an increase in the concentration of phenolic compounds in water extracts resulted from an increasing solvent pH. The results show the probable involvement of lichen substances in biogeochemical processes in nature and their promising use for a variety of human necessities.

Mineralogical Characteristics of Color-Changing Garnet and the Effect of Light Path Length on Color

The color-changing garnet displays the “alexandrite effect”, changing from green in daylight to purplish-red under incandescent light. The mineralogical characteristics of color-changing garnet is analyzed using Raman spectroscopy, ultraviolet-visible (UV-Vis) spectroscopy, an electron probe, and laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS). The color of garnets with different thicknesses was calculated using the International Commission on Illumination (CIE 1976) L*a*b* uniform color system. The results revealed the presence of rutile inclusions in color-changing garnet. Strong absorption in both the blue-violet zone and orange-yellow zone was the main cause for the color-changing effect of garnet. The distribution pattern of rare earth elements (REE) was left-leaning, showing the enrichment of heavy rare earth elements (HREE) and depletion of light rare earth elements (LREE). As the total Cr and V concentrations increased, the area of the 574 nm absorption peak in the UV-Vis spectrum also increased, leading to a more significant variation in color ΔE*ab. The light path length of the gemstone had a significant impact on the extent of the color-changing effect. The color difference reached a maximum and the color-changing effect was most visible when the thickness of the gemstone was 5 mm.

Fractal phototherapy: impact on the structure and function of the retina of rabbits with modelled retinal pigment epithelium atrophy

It is believed that in degenerative diseases of the retina, photostimulation by fractal dynamics signals activates neuroplasticity, thereby increasing the efficiency of visual rehabilitation. Previously, we showed a positive effect of fractal phototherapy (FF) on the electroretinogram (ERG) of healthy rabbits and demonstrated the safety of long-term photostimulation courses for the retina. The purpose of this work is to study the effect of FF on the functional activity and morphology of the retina in rabbits with a model of retinal pathology. Material and methods. We modelled an atrophy of retinal pigment epithelium (RPE) on both eyes of 50 rabbits. 30 days after the administration of bevacizumab, the animals were divided into two groups of 25 animals each. In the main group, photostimulation was performed using a device for FF, while in the control group incandescent lamps were used that create radiation of constant intensity. In both groups, 20-minute binocular light stimulation sessions were performed daily, five times a week. ERG and optical coherence tomography of the retina were performed before and after courses of treatment which lasted 1 week, 1 and 3 months. Results. Long-term courses of FF were shown to be safe for the morphology of the retina of animals with the RPE atrophy model. In all periods of observation, biochemical studies revealed no statistically significant changes in the content of norepinephrine and dopamine in the tear as compared with baseline values. In the main group, a slight positive effect of FF on rod and cone ERG was found after 5 FF sessions, while a significant increase in the amplitude of the transient and steady-state pattern-ERG (PERG), most pronounced after a 1-month FF course, was observed. Conclusions. A positive effect of FF on the functional activity of retinal ganglion cells (RGC) may suggest that prescribing a course of FF lasting up to 1 month (20 sessions) in diseases accompanied by a pathology of RGC is advisable, whereas for patients with a pathology of the macular region, such as AMD, an effective improvement in the activity of photoreceptors and bipolar cells could probably be achieved through a 1-week course of FF, conducted under the control of electroretinography.

Incandescent Lamp from Black Body Perspective

The incandescent lamp from black body perspective was investigated using commercial lamps of various watts. The major component of the incandescent lamp is the tungsten filament. The resistance of the tungsten filament was measured using a digital multimeter at an initial laboratory temperature. Light produced from lamp was separated into visible colours by an equilateral triangular glass prism. Deduced resistances were used to obtain equivalent temperatures by power-law parameterization. The Wien’s displacement law was used to estimate Peak wavelengths at different temperatures. The diameter of the tungsten was measured after dissecting the lamp, and this was used to determine its cross-sectional area. Both Wien’s displacement law and Stefan-Boltzmann expressions were applied in determining the filament’s spectral emissive power (SEP) in comparison with that of the visible spectrum. Planck’s graph of intensity using peak wavelength of tungsten filament as reference was juxtaposed with the intensity of visible spectrum using OriginPro 2016 SR0 b9.3.226. The maximum temperature attained was 2852.87 K with (SEP) of 1478955.24 Wm-2 for the 200W lamp. For the 100W lamp, the (SEP) obtained was 749347.9078 Wm-2 at 2489.14 K. Both temperatures, and even as low as 1250 K, were in agreement with Wien’s displacement law. The percentage estimation of visible spectrum in the radiation was about fourteen percent (14 %) while the rest was infra red radiation. This low visible light produced may be as a result of the non-ideal black body nature of the tungsten filament; and so, the incandescent lamp may be considered a quasi-black body.

Incandescent Lamp from Black Body Perspective

The incandescent lamp from black body perspective was investigated using commercial lamps of various watts. The major component of the incandescent lamp is the tungsten filament. The resistance of the tungsten filament was measured using a digital multimeter at an initial laboratory temperature. Light produced from lamp was separated into visible colours by an equilateral triangular glass prism. Deduced resistances were used to obtain equivalent temperatures by power-law parameterization. The Wien’s displacement law was used to estimate Peak wavelengths at different temperatures. The diameter of the tungsten was measured after dissecting the lamp, and this was used to determine its cross-sectional area. Both Wien’s displacement law and Stefan-Boltzmann expressions were applied in determining the filament’s spectral emissive power (SEP) in comparison with that of the visible spectrum. Planck’s graph of intensity using peak wavelength of tungsten filament as reference was juxtaposed with the intensity of visible spectrum using OriginPro 2016 SR0 b9.3.226. The maximum temperature attained was 2852.87 K with (SEP) of 1478955.24 Wm-2 for the 200W lamp. For the 100W lamp, the (SEP) obtained was 749347.9078 Wm-2 at 2489.14 K. Both temperatures, and even as low as 1250 K, were in agreement with Wien’s displacement law. The percentage estimation of visible spectrum in the radiation was about fourteen percent (14 %) while the rest was infra red radiation. This low visible light produced may be as a result of the non-ideal black body nature of the tungsten filament; and so, the incandescent lamp may be considered a quasi-black body.

EFFECT OF SUPPLEMENTARY LIGHT ON GROWTH, FLOWERING AND CUT FLOWER QUALITY IN TWO CULTIVAR OF CARNATION PLANT

This study was conducted to investigate the effects of different types of light and some factors on some vegetative growth and flowering of two cultivars of carnation plant (Dianthus caryophyllus L.). The results showed the maximum leaves number, leaf area per plant, internodes number and intermodal length were recorded under 14h incandescent (41.09 leaves/plant, 363.91 cm2, 18.70 node/plant, and 7.675 cm) respectively, and the increase was significant. While the effect of triple interaction, which showed a significant effect in all characteristics, the largest leaf area per plant (578.66 cm2) was obtained from the moonlight cultivar when cultured on the media containing 60% local compost and exposed to the 14h incandescent, Also, the maximum vase life was found in the Ormea cultivar (17.47 days) when the cultivar was exposed to the 14h incandescent and was cultured on medium that included 60% local compost. The best grade flower was obtained when the Ormea cultivar was cultured on a medium containing 30% and 60% local compost under 14 hours of incandescent light, reaching 3.89.