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1

Large scale calculation for holography using SSD

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Sugiyama A., Akiyama H., Hashikawa S., Shimobaba T., Kakue T., Ito T.
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vol. 6
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issue 3
87-89
EN
Computer based holography such as electro-holography and digital holography advances because the resolution of an imaging display and a sensing device such as a liquid crystal display (LCD) and a charge coupled device (CCD) becomes higher. The higher resolution of an imaging device requires a more powerful computing system. On the other hand, a solid state drive (SSD) develops as a storage device of computers. We studied the effectiveness of an SSD for a large-scale digital holography calculation. When the calculation data scale exceeds the main memory capacity, the SSD system showed better performance compared with a hard disk drive (HDD) system at computational speed and stability.
2

Native frame rate single SLM color holographic 3D display

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Zaperty W., Kozacki T., Kujawinska M.
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vol. 6
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issue 3
93-95
EN
In this paper we present a single SLM color holographic 3D display with a spatial only multiplexing method. The SLM is illuminated simultaneously with three beams. A color (RGB) filter mask placed in front of the SLM surface distributes illuminating beams to respective component holograms. After propagation, modulated wavefronts overlap in space and create a real color 3D image. The display works with a native SLM frame rate, but with the cost of spatial bandwidth product reduction. In the paper we present the method's capabilities and discuss its limitations. Finally, we present the display implementation and resulting color holographic reconstruction of a computer generated 3D object.
3

Photochemical bonding of special optical fibers

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Ertman S., Bielska M., Czapla A., Domosławski K., Chychłowski M., Reszka K., Woliński T. R.
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vol. 6
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issue 3
114-116
EN
The most popular method for permanent connecting of optical fibers is thermal bonding with fusion or filament splicers. However, this method in some cases is not suitable, for example if the connected fibers are made of materials with different melting temperatures (i.e. silica and soft glass fibers) or in the case of microstructured optical fibers filled with materials which are highly sensitive to high temperature (i.e. organic materials such liquid crystals). In this work we will present some practical issues of an alternative method of permanent connecting various types of optical fibers by gluing with the use of photo-curable adhesives.
4

Time efficient method for defocus error compensation in tomographic phase microscopy

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Kostencka J., Kozacki T., Dudek M., Kujawińska M.
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vol. 6
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issue 3
102-104
EN
We present a holographic method for defocus error compensation in tomographic phase microscopy, which enables high quality reconstruction in the presence of a meaningful run-out error of the measurement system. The proposed method involves indirect determination of the sample displacement from the in-focus plane. The sought quantity is deduced from the transverse movement of the rotating sample, which can be determined with high precision using correlationbased techniques. The proposed solution features improved accuracy and reduced computation time compared to the conventional autofocusing-based approach. The validity of the concept is experimentally demonstrated by tomographic reconstruction of an optical microtip.
5

Computer holography becoming practical

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Makowski M.
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vol. 6
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issue 3
80
EN
This editorial contains the overview of the contents of the latest volume of the Photonics Letters of Poland, devoted mainly to holography. The published papers from international research groups show a slow but constant approach of holography towards practical applications in the future. This includes both scientific measurement techniques and future consumer electronics display devices.
6
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Functional features and hygienic aspects of LED lamps

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Janosik E., Marzec S., Marczak W., Nowicka J., Zachara J.
Medycyna Środowiskowa - Environmental Medicine
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2015
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vol. 18
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issue 4
15-22
EN
Aim of the study: The aim of this study was to identify characteristics of the LED lamps and their influence on perceptual abilities and feeling of a human. Materials and methods: Technical parameters of ten chosen LED sources of light were determined. The sources varied among each other, according to the shape, colour temperature, colour rendering index and also name of the manufacturer. For each of the analysed sources of light, the illuminance, lighting uniformity, lighting luminance and degree of glare were determined. Moreover, also a subjective evaluation of the lighting conditions created by those lighting sources was performed. Results and conclusions: The study results have shown that the majority of the analysed sources of light provided their users with a good visibility and comfort of vision, but on the other hand, if used in an inappropriate way, they may be the reason for the unaccepted glare. It has been stated that the appropriate use and earlier – the well-thought-out choice of the LED sources of light are crucial. One has to consider the luminous flux, the colour temperature, the shape, as well as the manufacturer, who guarantees the quality and the safety class of the LED source of light.
PL
Cel badań: Celem badań było poznanie właściwości ledowych źródeł oświetleniowych i ich wpływu na możliwości percepcyjne człowieka oraz jego samopoczucie. Materiał i metodyka badań: Określono parametry techniczne dziesięciu, wybranych źródeł LED, różniących się między sobą kształtem, mocą, temperaturą barwową, wskaźnikiem oddawania barw, a nawet marką producenta. Dla każdego, badanego źródła wyznaczono natężenie oświetlenia, równomierność oświetlenia, luminancję świetlną oraz stopień olśnienia, a także dokonano subiektywnej oceny warunków oświetlenia, stwarzanych przez te źródła. Wyniki i wnioski: Wykazano, że większość z badanych źródeł LED zapewnia dobrą widoczność i wygodę widzenia, ale jednocześnie przy nieprawidłowym stosowaniu może być powodem nieakceptowalnego olśnienia. Stwierdzono, że bardzo istotne jest prawidłowe użytkowanie oraz wcześniej – przemyślany wybór źródła LED, biorący pod uwagę strumień świetlny, temperaturę barwową, kształt, a tak- że markę producenta, która gwarantuje jakość i klasę bezpieczeństwa źródła LED.
7

Analysis of computational complexity in holographic lens-less projection

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Kowalczyk A., Bieda M., Makowski M., Ducin I., Kakarenko K., Suszek J., Sobczyk A.
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vol. 6
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issue 3
84-86
EN
In lens-less projection the illuminating wavefront must be modified, so that after propagation on a certain distance it would form an image on the screen. Formed images will be displayed with a frame rate minimum of 20fps in the case of an animated movie. Thus, the speed of computing is extremely important. Computing might be performed by the central processing unit (CPU) or the graphics processing unit (GPU). Reaching a compromise between computational complexity (as well as the time of computing) and the quality of an obtained image is needed. This leads to a need for a proper iteration number of an algorithm, its parameters and size of computing matrices.
8

Fast calculation of a computer-generated hologram for RGB and depth images using a wavefront recording plane method

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Okada N., Shimobaba T., Ichihashi Y., Oi R., Yamamoto K., Kakue T., Ito T.
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vol. 6
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issue 3
90-92
EN
n a three-dimensional display by a computer-generated hologram (CGH), fast computation of CGH is required. In this paper, in order to accelerate CGH generation, the following two methods are used; the first method is band-limited double-step Fresnel diffraction. Compared with convolution-based diffraction, such as an angular spectral method, the proposed method requires less computational time and memory. The second method is a wavefront recording plane (WRP) method which reduces the calculation amount by placing WRPs in the vicinity of an object. We succeeded in speeding up CGH calculation by combining both methods.
9

Crystal growth and Characterization of an NLO material: L-cysteinium Sodium Nitrate Chloride (LCSNC)

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Azeezaa V., Pragasam J. A., Sunitha T. G.
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vol. 6
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issue 3
105-107
EN
In the present work, L-Cysteinium Sodium Nitrate Chloride (LCSNC) an organic nonlinear optical material has been synthesized by a slow evaporation method. The crystalline nature was confirmed by single crystals X-ray diffraction analysis. The UV-Vis transmittance spectrum shows that the crystal has a good optical transmittance in the entire visible region with lower cutoff wavelength 203 nm. The various functional groups and chemical compositions of the grown crystal have been derived from FTIR spectral analysis. Both dielectric constant and dielectric loss decrease with an increase in frequency. The SHG efficiency was measured by employing the powder Kurtz method.
10

Experimental study of noise and image resolution in holographic projection with different spatial division techniques

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Kakarenko K., Ducin I., Makowski M., Kowalczyk A., Bieda M., Suszek J.
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vol. 6
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issue 3
96-98
EN
In lens-less projection it is reasonable to display on the Spatial Light Modulator various holographic phase distributions and decide which gives the best results on the projection screen. The merit functions are high contrast and low noise ratio in projected images. For that reason we designed holograms to be displayed on the light modulator in 7 different methods. In particular, different resolutions and placements of mosaics of sub-holograms were examined.
11
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Patient dose and lifetime cancer risk from contrast-enhanced radiography examination in a tertiary health institution in Delta State, South-South, Nigeria

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Eze E. M., Chiegwu H. U., Zira J. D., Omojola A. D., Asogwa O. C., Okon E. E., Ihefobi C.
World News of Natural Sciences
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2023
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vol. 46
87-100
EN
Contrast-enhanced radiography examination requires multiple exposures and may sometimes involve the patient receiving a higher radiation dose than expected. The study was aimed at determining the mean entrance skin doses (ESDs), dose area products (DAPs) and effective doses (Eff) for 6 interventional procedures. The study was compared to similar guidelines and articles, with the aim of fashioning out a local diagnostic reference level in the region and it also determined the lifetime cancer risk for 3 out of the 6 contrast-enhanced procedures. The study used a 3-phase ceiling-mounted digital radiography (DR) X-Ray Unit (POLYRAD PREMIUM CS-Radiologia). A total of 140 investigations were carried out and the average patient age was 45.35 years. Patient doses were estimated using thermoluminescent dosimeters (TLDs) [Lithium Fluoride doped with Magnesium and Titanium (LiF: Mg, Ti)]. Patient ESDs and DAPs for barium enema (BE), barium meal (BM), barium swallow (BS), hysterosalpingogram (HSG), intravenous urogram (IVU) and micturating cystourethrogram (MCU) ranged from 7.51-12.01 mGy and 7.25-13.65 Gy.cm2, while the effective doses (Eff) ranged from 1.45-4.10 mSv. The DAP for BE, BM, BS and IVU was lower compared to the United Kingdom (UK), Ireland and Japan but HSG and MCUG were higher compared to the UK reports. The lifetime cancer risk for BS (46 per million) and IVU (114 per million) was comparable to the United Kingdom (UK) Health Protection Agency (HPA), while the lifetime cancer risk was doubled for BE compared to the UK HPA report. The study proved useful in areas where the use of contrast-enhanced radiography is still in use. The study has demonstrated that lower ESD and DAP can be achieved, which is comparable to the fluoroscopy modality.
12

Optimized computation method for real - time holographic formation of color images

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Makowski M., Ducin I., Kakarenko K., Kowalczyk A., Bieda M., Suszek J.
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vol. 6
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issue 3
81-83
EN
A simple method is presented of decreasing the calculation time of CGH for lensless Fourier holograms. The proposed method takes advantage of the fact that modern displays are rectangular with a high image proportion ratio of 16:9 or even higher. The CGH was calculated on a matrix of 512×1024 points. The use of small rectangular calculation matrices allowed three times fasters calculation with sustained contrast and noise ratio and greatly improved resolution.
13
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Determination of Track Density of Animal Bones using CN-85 Detector

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Kadhim Y. A., Kadhim N. F., Najam L. A.
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vol. 26
138-145
EN
The aim of the study is to calculate the alpha emitters in bone samples of some animals by counting the tracks of alpha particles emitted from radioactive nuclei (Pb-210, Po-210, Ra-226) using the CN-85 detector. The detectors were kept with the samples in closed clear plastic cups at a 2 cm distance for 60 days. The track density in the detector, and, hence, the alpha emitters from the bones were counted with an optical microscope after etching the detectors with an etchant solution (NaOH). The results showed that the optimum etching time of CN-85 when using to detect alpha emitted from natural radionuclides were 40 mins and the highest track density were found in chicken, beef, and sheep respectively.
14
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Decontamination of Treated Wastewater By means of a Modern Ultraviolet LED Reactor System

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Adewale A. O., Abraham O. A., Paul O. I., Latifah O. O., Kayode A. B.
World News of Natural Sciences
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2022
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vol. 45
18-36
EN
Poor sanitation systems have been a significant contributor to high death rates in many low-income countries since they tend to promote the spread of waterborne diseases. Both the public and commercial sectors have a strong interest in developing and upgrading the health systems in these countries. Chemical oxidants that are commonly used (e.g., chlorine) signify the method most commonly used to disinfect wastewater due to some practical rewards. Nevertheless, a lot of evidence shows that harmful by-products of disinfection (DBPs) have a direct link to DBP generation. This research investigates the use of UV-LEDs to sterilize the secondary household sewage treatment system. Though UV-LED treatment has grown in popularity recently, it is still a cutting-edge method for treating domestic sewage. Domestic sewage was pretreated via an affordable pretreatment structure containing a settler inclined at an angle and a sand-medium screen before being fed into a novel flow-through ultraviolet LED reactor. Reusing processed wastewater from treatment plants that use UV-based combination processes shows outstanding potential due to a negligible impact on the environment relative to disinfection byproducts generation and effective microorganism-based disinfection at high yields, but more research is needed to confirm this (more than a three-log reduction is typical).
15
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Raport z działalności PKiM oraz PFN w latach 2021–2022

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Tymiński Z.
Acta Societatis Metheoriticae Polonorum
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2023
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vol. 14
183-191
EN
The Polish Fireball Network (PFN), has been undergoing continuous development. Since then, several large grants have been obtained, which were at least partly used for modernization purposes. In recent years, two more grants have been obtained, which allowed for the expansion and modification of the existing PFN infrastructure. In 2021, the PFN76 Kozienice was modernized, but also the PFN14 Zielona Góra station was reactivated and the new PFN77 Suhora station was launched in 2022. Thanks to these improvements, the tracking of meteoroids entering the Earth Atmosphere above Poland became more accurate, which facilitates the search for meteorites and increases the chances of finding new fresh meteorites in Poland. On the night of May 10, 2021, PFN stations registered an exceptionally slow bolide. The phenomenon named PF100521 Wykrot appeared over central Poland in the Mazowieckie Voivodeship at 21:32 UT and calculations showed that some meteorites may have fallen. This phenomenon was used to conduct a series of analyzes to show how observational uncertainties affect the final results. Two variants of the results are presented in this work.
16
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Adsorption behavior of pharmaceutically active dexketoprofen as sustainable corrosion Inhibitor for API X80 carbon steel in acidic medium

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Nkem B. I., Abosede O. J.
World News of Natural Sciences
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2019
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vol. 27
22-37
EN
The inhibition of X80 carbon steel corrosion in 1 M HCl solution by dexketoprofen (DKP) was studied using weight loss (WL), electrochemical impedance spectroscopy (EIS), potentiodynamic polarization (PDP) and scanning electron microscopy (SEM) techniques. The results indicated that DKP acts by way of adsorption as an effective protective inhibitor in the aggressive acid medium. The inhibition efficiency of DKP increased with concentration but was lower at higher temperature. The results of potentiodynamic polarization showed that DKP molecule behaved as a mixed type inhibitor by reducing both the anodic and the cathodic electrochemical reactions. Dexketoprofen was adsorbed on the X80 steel surface in accordance with Langmuir adsorption isotherm. SEM analyses supported formation of protective film on the X80 steel in the presence of DKP.
17
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Pochodzenie materii meteorytowej

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Kozłowski S.
Acta Societatis Metheoriticae Polonorum
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2023
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vol. 14
100-113
EN
In this article, I briefly review the history of the elements in the Universe, starting from cosmic inflation and ending at the creation of elements and minerals that we find in meteorites.
18

Compact and Wide-band Hybrid Metal-Insulator Plasmonic Directional Coupler

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Noghani M. T., Samiei M. H. V.
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vol. 6
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issue 3
108-110
EN
A compact and wideband plasmonic directional coupler is proposed based on a hybrid metal-insulator slab waveguide (HMISW). A transfer matrix method (TMM) is adopted to analyze the multilayer structure. The hybrid waveguide is composed of a metallic layer of silver and two dielectric layers of silica (SiO2) and silicon (Si) with high index contrast. Coupling length and maximum transferred power are optimized according to dielectric layer thicknesses. It is shown that submicron coupling length is achieved with a wide bandwidth and high efficiency, being advantageous to conventional directional couplers.
19
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Heating-times of tungsten filament incandescent lamps

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Dulli C. A.
World News of Natural Sciences
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2017
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vol. 15
86-97
EN
Electricity provides power to incandescent lamps to heat the filament hot enough so that it provides light for illumination. The time taken to achieve a state of full brilliance after being turned on is so fast that it may be presumed to be adiabatic, hence it is deemed adiabatic heating time. In view of the fact that in actual practice simultaneously black-body radiation cools the filament, the General Electric in its bulletin provides a better time scale describing heating and cooling of filament. These are average times required for the filament to warm up to 90 per cent light output after the circuit is closed, or to cool down to 10 per cent after the circuit is opened, respectively. The exercise of estimating luminous flux and heating-times for typical 10, 100, 500 and 1000 W lamps have been undertaken for the first time for the benefit of students. This problem involves three disciplines electricity, optics and heat. The first describes the power needed to heat the filament quickly, optics then helps us in determining the light output and discipline of heat provides methods for solving the heat equation in order to estimate time to light or time to darkness. The study reveals that the supposition of linear configurations for the filaments neither matches luminous flux nor the heating-times. HS Leff’s suggestion of introducing a shadow factor which reduces the exposed surface area, as it so happens in the coiled filaments, successfully explains the measured observations.
20
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Cooling-times of tungsten filament lamps

100%
Dulli C. A.
World News of Natural Sciences
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2017
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vol. 13
52-62
EN
During steady-state operation, hot-coiled filaments in incandescent lamps provide luminous flux for illumination, but when switched off, the temperature, as well as the light output drops quite fast. The cooling-time of a lamp is the time required for the hot filament to cool down to ten per cent light output after the circuit is opened. In this paper, the exercise of estimating luminous flux and cooling-times for typical 10, 100, 500 and 1000 W lamps has been undertaken for the first time for the benefit of students. This problem involves three disciplines: electricity, optics and heat. Information drawn from field of Electrical studies allows us to understand the power that quickly heats the filament, followed by that from optics that helps us in determining the light output, while heat studies are responsible for understanding the cooling of the hot filament. This last is largely explained through the Stefan-Boltzmann law. In this paper, we show that the supposition of linear configurations for the filaments neither matches luminous flux nor the cooling-times. Both fall short. H.S. Leff’s suggestion of introducing a shadow factor that reduces the exposed surface area, as it so happens in the coiled filaments, successfully explains the measured observations.
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