Tungsten Filament Bulb Research Articles

Planck’s Constant from Stefan’s Radiation Law: A study of gray radiations of Tungsten Filament Bulb

Abstract This study introduces a straightforward approach to determine Planck's constant in an undergraduate course at the college or university level through the analyses the current-voltage (I-V) characteristic of a tungsten filament bulb. Unlike conventional methods, this analysis does not require the use of a color filter or an additional photodiode to select a specific wavelength or measure the emitted energy density from the filament. The temperature of the filament was computed by measuring the resistance of the filament. The obtained temperature and the input power of the filament are then used to estimate the emissivity of the filaments using Stefan-Boltzmann's law, which is found to be lower than that of a perfect black body, i.e. unity. Therefore, the radiation emitted from the tungsten filament can be classified as gray radiation. The maximum energy density (intensity) of the emitted radiation is determined by calculating the consumed power of the filament. Finally, the obtained values of temperature, Stefan's constant, and the intensity of the emitted radiation are used to calculate Planck's constant. The calculated value of Planck's constant is found to be 6.102x10-34 Js, which closely matches the standard value of Planck's constant (6.626x10-34 Js). This close correlation between the two values validates the effectiveness of the present method.

Synergistic Pd/Ag-Catalyzed Domino Reaction: Access to Tetrahydropyrano[4,3-c]pyran and Hexahydrofuro[2,3-b]pyran.

We report the Pd-catalyzed and Ag-mediated temperature-dependent divergent synthesis of tetrahydropyrano[4,3-c]pyran and hexahydrofuro[2,3-b]pyran derivatives from a single substrate, alkynols. The reaction involves homocoupling of alkynols to form two C-O bonds and one C-C bond, resulting in tetrahydropyrano[4,3-c]pyran cores at a high temperature (110 °C). Exposing tetrahydropyrano[4,3-c]pyrans to a 200 W tungsten filament bulb yields tetrahydrofuro[2,3-b]pyrans. At lower temperatures (30-60 °C), alkynols produce hexahydrofuro[2,3-b]pyrans. The density functional theory study explains temperature-dependent selectivity.

Estimation of constants of thermal radiation using tungsten filament bulb.

The concept of black body is of primary importance in studying the energy transfer of thermal electromagnetic radiation at all wavelengths. Several physical bodies like incandescent lamps, electric heaters, stoves, the sun and the other stars, microwave background radiation, etc, are considered to be black bodies as their radiation spectra fits the black body radiation curve. The planck’s constant , quantises the energy emitted by a black body in integral multiples of , being the frequency of the emitted radiation. We present here an experiment using a low cost apparatus to estimate the value of Planck Constant by studying the radiation of a 40 W tungsten filament bulb within the accuracies of 10%. Such an experiment can be easily implemented in undergraduate college laboratories. The experiment can also be used to verify the Stefan-Boltzmann law and Wien’s displacement law.

Using the Arduino with MakerPlot software for the display of electrical device characteristics

This paper shows how very simple circuitry attached to an Arduino microcontroller with MakerPlot software can be used for the display of electrical characteristic curves of three commonly available devices: an ohmic resistor, an LED, and a tungsten-filament bulb.

Fabrication via Ultrasonication and Study of Silicon Nanoparticles

AbstractPhotoluminescent porous silicon (PSi) were prepared by an electrochemical etch of n-type silicon under the illuminationwith a 300 W tungsten filament bulb for the duration of etch. The red photoluminescence emitting at 620 nm with anexcitation wavelength of 450 nm is due to the quantum confinement of silicon nanocrystal in porous silicon. As-preparedPSi was sonicated, fractured, and centrifuged in toluene to obtain photoluminescence silicon quantum dots. BET and BHJmethods were employed to study the specific surface area of as-prepared PSi. Optical characterization of redphotoluminescent silicon nanocrystal was investigated by UV-vis and fluorescence spectrometer. Also SEM and TEMimages of porous silicon and nanoparticles were investigated.Keywords: Silicon Nanoparticle, Electrochemical Etching, Porosity, Ultrasonication 1. Introduction Since the discovery of photoluminescent porous sili-con (PSi) [1] it has been gaining growing popularity andgreat potential in chemical sensor

Photoluminescence Enhancement of Silole-Capped Silicon Quantum Dots Based on Förster Resonance Energy Transfer.

Photoluminescent porous silicon were prepared by an electrochemical etch of n-type silicon under the illumination with a 300 W tungsten filament bulb for the duration of etch. The red photoluminescence emitting at 650 nm with an excitation wavelength of 450 nm is due to the quantum confinement of silicon quantum dots in porous silicon. HO-terminated red luminescent PS was obtained by an electrochemical treatment of fresh PS with the current of 150 mA for 60 seconds in water and sodium chloride. As-prepared PS was sonicated, fractured, and centrifuged in toluene solution to obtain photoluminescence silicon quantum dots. Dichlorotetraphenylsilole exhibiting an emission band at 520 nm was reacted with HO-terminated silicon quantum dots to give a silole-capped silicon quantum dots. The optical characterization of silole-derivatized silicon quantum dots was investigated by UV-vis and fluorescence spectrometer. The fluorescence emission efficiency of silole-capped silicon quantum dots was increased by about 2.5 times due to F6rster resonance energy transfer from silole moiety to silicon quantum dots.

Fabrication and Characterization of Photoluminescent Silicon Nanoparticles for Drug Delivery Applications

Photoluminescent silicon nanoparticles containing camptothecin (CPT) were fabricated by using a CPT-derivatized porous silicon (PSi). PSi samples displaying red photoluminescence (PL) were prepared by an electrochemical etch of n-type silicon under the illumination with a 300 W tungsten filament bulb for the duration of etch. For the drug-derivatized PSi, luminescent PSi was oxidized and derivatized with CPT. Silicon nanoparticles containing CPT were obtained by fracturing of luminescent PSi with ultrasono-method. Optical characteristic of drug-derivatized silicon particles were investigated in aqueous buffer solution. The release of CPT was measured by UV-vis spectrometer. The intensity of fluorescence of the silicon nanoparticles was measured with a drug release. The concentration of released drug exhibited non-linear relationship with a release time.

Study of Heat Loss from Hot Tungsten Filament Bulb Using AT89C51 Based Data Acquisition System

Study of Heat Loss from Hot Tungsten Filament Bulb Using AT89C51 Based Data Acquisition System

LIGHT EMITTING DIODES IN BIO-IMAGING

Light-emitting diodes (LEDs) can and are currently integrated into light microscopes. They have numerous advantages as illumination sources. Most notably, they provide intensity (brightness) and spectral control during bio-imaging. For transmitted light imaging, LEDs can replace the traditional tungsten filament bulb, while offering longer life, little-to-no color temperature shift resulting from an intensity change, reduced emission in the infrared region, (a property important for live cell imaging), and reduced cost of ownership. For fluorescent imaging, in which the typical illumination sources are mercury or xenon lamps, LEDs offer the advantages of a longer lifespan, greater spatial and temporal stability, elimination of the need for mechanical shutters and neutral density filters, significantly lower cost of ownership, and reduction of photon dose at the specimen. Additionally, LEDs permit vibration-free, high-speed spectral and temporal modulation. This modulation allows more information to be obtained for a given photon dose.

Spectrophotometers

Spectrophotometers

Statically scanned single and tandem low-coherence interferometers

Statically scanned single and tandem Michelson interferometer configurations are compared for the remote measurement of thermally induced group delay change in optically dispersive glass samples. A broadband tungsten filament bulb was used to illuminate the single interferometer, and a much narrower spectral bandwidth superluminescent diode (SLD) was used to illuminate the tandem interferometer. For a BK7 glass sample, measurements of thermally induced group delay changes were made with <0.5 fs root mean square error for optical path delay (OPD) scan lengths of only 260 µm when applied to low-coherence interferograms with signal-to-noise ratios as low as 6.5 dB. These results demonstrate the power of dispersive Fourier transform spectrometry (DFTS) applied to noisy, dispersion distorted low-coherence interferograms captured with non-mechanical, short path length scans. Further, following experimentally observed source bandwidth-induced measurement resolution limitations between the different illuminating sources, simulations were performed to examine this feature.

Chemical Sensor Based on Porous Silicon Dual Transducers

Novel porous Si exhibiting dual optical properties, both Fabry-Perot fringe (optical reflectivity) and photoluminescence, were developed and used as chemical sensors. Porous Si samples were prepared by an electrochemical etch of p-type silicon under the illumination with a 300 W tungsten filament bulb for the duration of etch. The surface of porous Si was characterized by FT-IR instrument. The porosity of samples was about 80%. Both reflectivity and photoluminescence were simultaneously measured under the exposure of organic vapors. The shift of Fabry-Perot fringe to the longer wavelength under the exposure of chloroform vapors was obtained. The steady-state photoluminescence spectra and quenching photoluminescence under the exposure of various organic vapors were obtained. A set of organic compounds were analyzed by both quenching photoluminescence and change of optical thickness.

Light-Emitting Diodes Are Better Illumination Sources for Biological Microscopy than Conventional Sources

Light-emitting diodes (LEDs) can be easily and inexpensively integrated into modern light microscopes. There are numerous advantages of LEDs as illumination sources; most notably, they provide brightness and spectral control. We demonstrate that for transmitted light imaging, an LED can replace the traditional tungsten filament bulb while offering longer life; no color temperature change with intensity change; reduced emission in the infrared region, which is important for live cell imaging; and reduced cost of ownership. We show a direct substitution of the typical tungsten bulb with a commercially available LED and demonstrated the color stability by imaging a histology section over a wide range of light intensities. For fluorescent imaging, where the typical illumination sources are mercury or xenon lamps, we demonstrate that LEDs offer advantages of providing a longer lifespan, having a more constant intensity output over time, more homogeneous illumination, and significantly lower photon dose. Our LED equipped system was used to image and deconvolve dual fluorescently labeled cells, as well as image cells undergoing mitosis expressing green fluorescent protein-histone 2B complex. The timing of the stages of mitosis is well established as an indicator of cell viability.

An interesting phenomenon

Before the tungsten filament bulb and the fluorescent tube disappear from the market, a very interesting phenomenon regarding their operation in a series is examined here. Reported by some electricians, the phenomenon is significant since it provides insight to the initiation of arc. Also, its maintenance is in a fluorescent tube with the help of a tungsten filament bulb instead of a choke.

Effect of Raceme‐Localized Supplemental Light on Soybean Reproductive Abscission1

The percentage of soybean [Glycine max (L.) Merr.] reproductive structures that abscise is a potentially important yield factor. To better understand the involvement of light in the abscission of reproductive structures, a series of in vitro raceme‐culture and growthchamber experiments were conducted. In the in vitro raceme‐culture experiments, racemes with four to six flowers at or past anthesis were excised from the soybean plant (genotype 1X93‐100), embedded in a complete nutrient, solid agar medium, and subjected to various light treatments. A series of three experiments indicated that the racemes contain a photoreceptor, possibly phytochrome, capable of regulating sucrose accumulation. In each of the growth chamber studies, supplemental light was supplied directly to individual soybean flowers via fiber optic light guides. The light source (a tungsten filament bulb) increased the photon flux to the flowers by 10‐fold. The first growth chamber experiment showed that flowers receiving supplemental light were more intense sinks for 14C‐sucrose than were controls (intensity value of 1.0 vs. 0.4 ✕ 10−7, intensity = [dps of flower/dps of raceme]/[kg dry wt of flower]). In a second study, 42% of flowers treated with supplemental light set pods, while only 26% of control flowers set pods. A third experiment showed that red supplemental light produced 55% fruit set, compared to 41% set for far‐red light, and 35% for controls (far‐red not statistically different than control, but all other comparisons are significantly different). These experiments indicate that both photoassimilate accumulation and abscission in young soybean reproductive structures may be regulated by light quality.

LIGHTING AND CYANOSIS

The frequency with which observers detected cyanosis at differing arterial oxygen saturation levels has been estimated in postoperative patients recovering from anaesthesia. The frequency in the light of a fluorescent tube, which meets the Medical Research Council's requirements, has been compared to that obtained using an examination lamp fitted with a tungsten filament bulb. There was no significant difference between the results obtained in the two lighting conditions. The differences in the frequencies of cyanosis examined at 5 per cent arterial oxygen saturation intervals were highly significant.