Red Filter Research Articles

Using RGB filters and a circularly polarized system to measure the deflection radius of optically anisotropic-polymeric substrates with a sub-grayscale resolution

Transparent optically anisotropic substrates (TOASs) are a crucial component in flexible electronics. Moreover, knowing the deflection radii of TOASs is essential to estimate the residual stresses of the thin films deposited on them. This paper proposes a novel measurement method to measure the deflection radii of polyimide (PI) substrates. Red, green, and blue filters and a circularly polarized system were used in the proposed method to investigate the influence of measurement precision on the wavelength of light adopted. Moreover, the image averaging technique was adopted to significantly reduce the noise in the fringe. Thus, the proposed method could be performed using only one set of image information and the measurement resolution could be improved to the sub-grayscale order. The experimental results reveal that red light can be adopted to precisely measure the deflection radii of PI substrates (error of 2.90%) However, large errors are caused when green light is used (22.35%). The experimental results reveal that blue light cannot be used to obtain any interferometric fringe patterns to calculate the deflection radius.

Research into Methods for Determining Colour Differences in the CIELAB Uniform Colour Space

A problem of qualitative determination of the results of colour image capturing by digital devices based on uniform colour systems arises during analysis of colour images. The article describes methods of determining colour difference as recommended by CIE for the CIELAB system, presents mathematical formulation of the system and its modifications, describes the programme developed for calculating colour difference for each described method, and describes testing of this programme using 14 sample colours from the Munsell Book of Colour. Three groups of red, green and blue filters with 7 filters in each were selected as the study object. The filters were selected based on possibility of their further application for determining colour shift by digital devices. Filter colour difference was studied in the groups with different standard sources of light and using three methods of calculation of this difference. Analysis of the obtained results is presented and conclusions are made on possibility to apply each method in different industrial spheres. The article may be useful for colour analysis specialists, quality inspectors and specialists in digital devices and computer vision.

Interpretation of Benign Gastric Mucosal Lesions Using Narrow-Band Imaging

AbstractThe major drawback of conventional white light endoscopy (WLE) is that it lacks accuracy in diagnosis and differentiation of various benign and premalignant mucosal gastrointestinal lesions. To overcome this, image-enhanced endoscopy techniques, which provide high-definition images with good resolution and contrast enhancement, have been developed. One such technique is narrow-band imaging (NBI). NBI functions by filtering the illumination light. The red component of the standard red, green, and blue filters is rejected and the selected bandwidth of the blue and green light is transmitted. The present review highlights the role of NBI in diagnosis of benign gastric lesions like atrophic gastritis, Helicobacter pylori–related gastritis, intestinal metaplasia, and other rarer conditions. NBI is a simple procedure which does not require any additional equipment and does not have a long learning curve. Use of NBI in daily practice is likely to improve detection of mucosal abnormalities.

Potential use of smartly engineered red mud nanoparticles for removal of arsenate and pathogens from drinking water

The aluminum industrial waste red mud was successfully utilized as a novel adsorbent for the removal of arsenic (As) ions from water. The arsenate (As (V)) adsorption efficacy of red mud nanoparticles was also investigated. Red mud nanoparticles were prepared by ball milling raw red mud for 10 h, yielding particles’ size of 20 nm on average. The As (V) adsorption on these nanoparticles strongly depended on the size of the nanoparticles. As (V) removal increased from 58 to 83% by reducing the size of red mud particles from 200 to 20 nm. Detail kinetics and transport study confirmed the pseudo-second-order kinetic process which was governed by external mass transport. The Freundlich (and Langmuir) isotherms confirm that the arsenate adsorption capacity changes from 2.28 mg/g (1.84 mg/g) to 2.54 mg/g (1.96 mg/g) for reduction of particles from size 200 nm to 20 nm. Water filter columns made with red mud nanoparticles prepared by ball milling for 10 h showed better filtration performance than the filter packed with raw red mud. Both the hydraulic conductivity and the As (V) removal (8 mm/h and 61% respectively) of influent 1 mg/L As (V) by red mud nanoparticles were greater than the raw red mud (3.2 mm/h and 54%). The modified red mud column filters also exhibited a higher efficiency than the raw red mud filters to remove Escherichia coli and Staphylococcus aureus from the water. Overall, this research shows that nanomaterials derived from aluminum processing waste can be a promising material for water filtration.

The OTELO survey

Context. A sample of low-mass Hα emission line sources at z ∼ 0.4 was studied in the context of the mass-metallicty relation (MZR) and its possible evolution. We drew our sample from the OSIRIS Tunable Emission Line Object (OTELO) survey, which exploits the red tunable filter of OSIRIS at the Gran Telescopio Canarias to perform a blind narrow-band spectral scan in a selected field of the Extended Groth Strip. We were able to directly measure emission line fluxes and equivalent widths from the analysis of OTELO pseudo-spectra. Aims. This study aims to explore the MZR in the very low-mass regime. Our sample reaches stellar masses (M*) as low as 106.8 M⊙, where 63% of the sample have M* < 109 M⊙. We also explore the relation of the star formation rate (SFR) and specific SFR with M* and gas-phase oxygen abundances, as well as the M*-size relation and the morphological classification. Methods. The M* were estimated using synthetic rest-frame colours. Using an χ2 minimization method, we separated the contribution of [N II]λ6583 to the Hα emission lines. Using the N2 index, we separated active galactic nuclei from star-forming galaxies (SFGs) and estimated the gas metallicity. We studied the morphology of the sampled galaxies qualitatively (visually) and quantitatively (automatically) using high-resolution data from the Hubble Space Telescope-ACS. The physical size of the galaxies was derived from the morphological analysis using GALAPAGOS2/GALFIT, where we fit a single-Sérsic 2D model to each source. Results. We find no evidence for an MZR evolution from comparing our very low-mass sample with local SFGs from the Sloan Digital Sky Survey. Furthermore, the same is true for M*-size and M*-SFR relations, as we deduce from comparison with recent literature. Morphologically, our sample is mostly (63%) populated by late-type galaxies, with 13% of early-type sources. For the first time, we identify one possible candidate outlier in the MZR at z = 0.4. The stellar-mass, metallicity, colour, morphology, and SFR of this source suggest that it is compatible with a transitional dwarf galaxy.

Transmission-mode all-dielectric metasurface color filter arrays designed by evolutionary search

All-dielectric metasurface (ADM) color filter arrays (CFA) are attractive for replacing conventional organic-dye color filters due to several advantages such as CMOS-compatibility, size scalability, and robustness to degradation. We propose metasurface designs with polygon-shaped unit cells for improving the performance of such filters. Our numerical results predict improvement in color purity for red, green, and blue primary color filters and significant reduction in insertion loss for blue filters as compared to the previously reported designs using simple circular shapes. The proposed differential evolution optimization methodology can be useful for improving the performance of other metasurface spectral filtering structures.

TRAFFIC LIGHT SYSTEMS MENGGUNAKAN VISIBLE LIGHT COMMUNICATION (VLC) SEBAGAI ALAT BANTU TUNANETRA UNTUK MENYEBERANG JALAN

The people with visual impairment have problems in mobility and orientation, especially in the outdoor environment. Recently, traffic lights systems, which is a facility where someone crosses do not support visually implaired people so they still need help from others in crossing the road. In this study, a system that integrates traffic lights is implemented using Visible Light Communication (VLC) technology, where the VLC transmitter is mounted on a traffic light, and the VLC receiver is installed as a wearable device that can be used with the audio information signal. The measurement is done by considering the use of color filters. The measurement results show that the transmitter system has been able to send signals with audio frequencies from 300 Hz to 4000 Hz. Besides that, receiving an information signal consisting of a audio signal from a transmitter mounted on a traffic light with a red, yellow and green color filter can be received by a VLC receiver that is placed on a visually impaired person of good quality with the signal voltage received above 4 Vpp, where the use of a yellow filter shows the best signal reception results with a voltage output of 5.00 Vpp at a frequency of 2400 Hz compared to other color filters.ABSTRAK: Penyandang tuna netra memiliki masalah dalam hal mobilitas dan orientasi, khususnya di lingkungan luar (outdoor). Pada sistem yang terdapat pada lampu lalu lintas (traffic light) yang merupakan fasilitas dimana seseorang menyebrang saat ini belum mendukung penyandang tuna netra, sehingga sampai saat ini masih membutuhkan bantuan orang lain dalam menyebrang jalan. Pada penelitian ini, sebuah sistem yang diintegrasikan pada lampu lalu lintas diimplementasikan menggunakan teknologi Visible Light Communication (VLC), dimana VLC transmitter dipasang pada lampu lalu lintas dan VLC receiver dipasang sebagai wearable device dengan sinyal informasi suara digunakan oleh penyandang tunanetra sehingga dapat menerima informasi mengenai kondisi lampu lalu lintas pada saat itu. Pengujian sistem dilakukan dengan mempertimbangkan penggunaan filter berwarna. Hasil pengukuran menunjukan bahwa sistem transmitter telah dapat mengirimkan sinyal dengan frekuensi suara dari 300 Hz sampai 4000 Hz. Disamping itu, penerimaan sinyal informasi berupa sinyal suara dari transmitter yang terpasang pada lampu lalu lintas dengan filter warna Merah, Kuning dan Hijau telah dapat diterima oleh receiver yang ditempatkan pada penyandang tuna netra dengan kualitas baik dengan tegangan sinyal yang diterima diatas 4 Vpp, dimana penggunaan filter warna kuning menunjukan hasil penerimaan sinyal yang paling baik dengan tegangan output 5,00 Vpp pada frekuensi 2400 Hz dibandingkan dibandingkan penggunaan filter warna lainnya

Enhanced mechanical properties and hydrophilic behavior of magnesium oxide added hydroxyapatite nanocomposite: A bone substitute material for load bearing applications

Hydroxyapatite is a multifunctional biomaterial that combines biocompatibility and bioactivity for various biomedical applications such as bone repairing and bioimaging. In the present study nano-hydroxyapatite (n-HAp) was synthesized using microwave irradiation technique. Subsequently, the MgO was introduced into the n-HAp matrix and various bioactive compositions of HAp-MgO nanocomposites were fabricated. The structural, mechanical, in vivo cell viability, and in vivo imaging properties of these nanocomposites were studied. The XRD results show that the composites sintered at 1200 °C, n-HAp partially decomposed into beta-tricalcium phosphate (β-TCP). The sintered density of the composites varying from 2.72 ± 0.066 to 3.03 ± 0.093 g cm−3 with the addition of 0.0–2.0 wt % of MgO. As increasing the amounts of MgO, a remarkable increase in the mechanical properties of the composite was achieved. The composite HAp-1.0MgO exhibited the highest mechanical properties with a compressive strength of 111.20 ± 5 MPa, fracture toughness 136.98 ± 5 MJ/m3 and revealed much amplification than pure n-HAp. Thus, the addition of MgO acting as an excellent mechanical reinforcing agent. The surface morphology of the composites revealed a significant change in the porous surface to denser. The low contact angle revealed the considerable hydrophilic nature of the composite surface. The biological study of these nano-composites with Drosophila third instar larvae indicated comparable or more favorable biocompatibility in terms of cell viability. Also internalized by Drosophila third instar larvae exhibited fluorescence under green and red filters using epifluorescence microscopy. Thus, the fabricated HAp-MgO nanocomposites with excellent biological properties are expected to be a multifunctional bioactive material for bone tissue regeneration and cell imaging applications.

Challenging a Myth and Misconception: Red-Light Vision in Rats.

Simple SummaryLight substantially influences animal physiology and behavior. Thus, it is a prerequisite to house laboratory animals under optimal light conditions. Different species possess different sets of photoreceptors, resulting in differential perception of the visible-light spectrum. While humans are trichromats with red-, green- and blue-sensitive cones, rats and mice are dichromats possessing ultraviolet- and green-sensitive cones. This led to the common assumption that red light is invisible to rodents and therefore red lights are commonly used in husbandry and experiments to observe animals during their dark phase. The retinal sensitivity of rats to red light though has never been assessed under scotopic conditions (dark-adapted) even though this mimics the setting red observation lights are being used. We examined the sensitivity to far-red light of the dark- and light-adapted rat retina. Our study demonstrates that the rat retina responds to far-red light under both conditions with great sensitivity, indicating that rats are not red-light blind. This should be taken into consideration when using red light to keep the effects of light on the retina and physiology to a minimum and will improve animal well-being and lead to better quality data by decreasing the variable light.Due to the lack of L-cones in the rodent retina, it is generally assumed that red light is invisible to rodents. Thus, red lights and red filter foils are widely used in rodent husbandry and experimentation allowing researchers to observe animals in an environment that is thought to appear dark to the animals. To better understand red-light vision in rodents, we assessed retinal sensitivity of pigmented and albino rats to far-red light by electroretinogram. We examined the sensitivity to red light not only on the light- but also dark-adapted retina, as red observation lights in husbandry are used during the dark phase of the light cycle. Intriguingly, both rods and cones of pigmented as well as albino rats show a retinal response to red light, with a high sensitivity of the dark-adapted retina and large electroretinogram responses in the mesopic range. Our results challenge the misconception of rodents being red-light blind. Researchers and housing facilities should rethink the use of red observation lights at night.

Quality of light and indolbutyric acid in vitro rooting of lavender

Abstract Lavender, an aromatic and medicinal plant, used in the extraction of essential oil, as an ornamental and meliferous plant, can be successfully propagated as long as the light, the nutrient medium and the growth regulators are adequate. The aim of the study was to evaluate the effect of different concentrations of indolebutyric acid (IBA) associated to distinct light spectra, on the in vitro rooting of Lavandula angustifolia. The experiment consisted in the combination of two concentrations of indolebutyric acid in the growth medium (0 and 0.1 mg L-1) and two light spectra, using cellulose acetate filters (blue and red), besides the control (without filter), totaling six treatments with four repetitions. For each repetition five explants were used. After 30 days, the variables evaluated were: survival percentage, number of buds and leaves, shoot length, number of roots, length of the longest root, shoot fresh and dry matter weight. There was a significant interaction among the indolebutyric acid concentrations and the light filters for the variables number of buds, leaves and roots and shoot length. Except for leaf number, promising results were obtained when the explants were held under red filters and with a concentration of 0 mg L-1 of indolebutyric acid in the growth medium. From these results, it can be concluded that the best in vitro rooting of Lavandula angustifolia is obtained when there is no indolebutyric acid in the growth medium associated with the use of the red filter.

How to Reduce the Potential Harmful Effects of Light on Blastocyst Development during IVF

Purpose: Earlier findings revealed the damaging effect of visible light on zygotes and gametes. The aim of our study is to eliminate or significantly reduce the potentially harmful effects of light exposure during in vitro fertilization (IVF) or intracytoplasmic sperm injection (ICSI) and to investigate the effect of light protection on embryo development and implantation. Materials and Methods: To protect sperm cells, oocytes, and embryos from the potential harmful effects of light exposure during laboratory procedures, we created a dark environment for the cells and applied red filters on laboratory lamps and UV or infrared filters in the microscopes in order to eliminate white light exposure of the cells throughout all work stages. Results: The fertilization rate was significantly (p = 0.011) higher in light-protected ICSI cycles. Blastocyst development rates (blastocyst/embryo) were significantly (p < 0.001) higher in light-protected embryos than in those manipulated in conventional light conditions both in IVF (20.9% difference) and ICSI (38.6% difference). Numbers of clinical pregnancies/transfers of ICSI fertilized day 5 blastocysts were also significantly (p = 0.040) higher in light-protected conditions. Conclusions: These data show that light protection has a positive effect on fertilization rate and increases the blastocyst development as well as the number of clinical pregnancies/transfers. Implementation of this light protection method in IVF centers may improve the success rate while maintaining maximal embryo safety.

Could Modifying the Bagolini Glasses Improve the Reliability of Responses?

Aims:Bagolini striated lenses are a useful test of binocular vision, but the variations in the striations (frequency and thickness) can impact on the perceived image. Also, responses can be difficult to interpret in young children. Therefore, the aims of this project were to evaluate the impact of striation frequency and the addition of coloured filters on subjective responses.Methods:Three sets of striated lenses were made (small, medium and large striations), each produced in two forms (both lenses clear, or with a red and blue lens). Also, Bagolini glasses (Optiker Ryser) were used, with and without the addition of red and blue filters. Subjects were asked to report what they perceived, with subsequent questions regarding the number and length of lines.Results:Forty-two adult subjects were tested, with uniocular VA ranging from –0.18 to 1.10 logMAR (mean 0.08 ± 0.25). The number of lines seen when varying the line thickness did not vary between coloured and clear lenses (post-hoc analysis following ANOVA, p > 0.1 in all comparisons). Adding red/blue filters to the original Bagolini glasses did not alter the rates of subjects perceiving a cross (Chi-square, p = 0.8). However, the laser-cut lenses produced a significantly shorter light streak than the original lenses (One-way ANOVA, p < 0.001), but the colour of the filters made no difference to the length of streak perceived (Tukey’s Test, p = 0.20).Conclusions:The addition of coloured filters did not impact on the responses given to the original or laser-cut lenses, suggesting this modification may aid responses in children. However, further evaluation is required with finer striations and thinner lenses to improve the visibility of the lines.

58 Effect of different light sources on the developmental capacity of bovine embryos produced invitro

Under natural conditions, mammalian oocytes and zygotes are never exposed to daylight or artificial light. During assisted reproductive procedures such as invitro production (IVP), oocytes and pre-implantation embryos are exposed to light from time to time before being transferred to recipients. The detrimental effect of visible light is not directly related to the intensity and exposure time, but is also a function of the spectral composition of the light. Recently, a green pass light filter was used during all steps of bovine IVP. Results indicated the protective effect of the filter against harmful blue and infrared regions of the light (Korhonen et al. 2009 Hum Reprod. 24, 308-314; https://doi.org/10.1093/humrep/den432). Data regarding either blue or infrared light are missing. Therefore, the effect of environmental light will be examined on the developmental capacity of bovine oocytes and pre-implantation embryos produced invitro. Three different experimental conditions were set during all IVP steps: (i) light from the microscope filtered with a red pass filter, no artificial light, and no daylight, (ii) artificial light without day light, light from the microscope without a filter, and (iii) artificial and daylight, light from the microscope without a filter, as normally used in the laboratory (control). Bovine cumulus-oocyte complexes were recovered from abattoir-derived ovaries by the slicing method. After 24h of maturation, fertilisation was realised and after 19h of co-culture of cumulus-oocyte complexes and sperm, presumptive zygotes were cultured in SOFaa for 8 days. Cleavage and developmental rates were recorded at Day 3 and Day 7/8 (Day 0=IVF, 10 IVP runs). Blastocysts from all groups were individually stored at −80°C until analyses. Then RT-qPCR (at least 12 replicates) was performed as described previously (Stinshoff et al. 2014 Reprod. Fertil. Dev. 26, 502-510; https://doi.org/10.1071/RD12372) for gene transcripts related to cellular stress (BAX, BCL2L1, HSPA1A, SOD1) and embryo developmental capacity (SLC2A3). The morphological quality of expanded blastocyst was assessed via a differential staining procedure (with propidium iodide and Hoechst, 4 replicates) to determine the number of inner cell masses (ICM), trophectoderms (TE), and total cells and to calculate the ICM/TE ratio. Data were analysed by analysis of variance followed by a Tukey test. Cleavage and developmental rates were similar in all groups of embryos (P&amp;gt;0.05). The relative abundance of all analysed gene transcripts was significantly increased (P ≤ 0.05) in blastocysts stemming from settings (i) and (ii) compared with those from the control group. Blastocysts generated using only artificial light or artificial and daylight did show a significantly increased number of ICM and total cells (86.3±3.2, 56.3±1.4; 183.6±4.0, 161.8±2.8) compared with embryos produced under filtered microscope light without any other light (35.3±0.8; 133.8±1.4; P ≤ 0.05). The number of TE cells was similar (P&amp;gt;0.05) in blastocysts of all groups (i: 98.5±1.3; ii: 97.3±2.6; iii (control): 105.5±2.4). These data suggest that day light exposure might influence bovine embryos at the molecular level, whereas the morphological quality seems to be unaffected when compared with embryos exposed to only artificial light.

Enhanced visualization of retinal vasculature using image processing

AbstractObjectiveTo develop a digital filter that enhances visualization of retinal blood vessels.MethodsFour‐hundred 24‐bit color fundus images were analyzed and properties of red, green, and blue channels were extracted. Then, using hemoglobin absorption coefficients, the relevant weights for gray‐scale conversion that emphasizes retinal vessels were calculated. To evaluate images, edges were detected via convolution‐al 2D Laplacian kernel from the processed images, and the number of edges, number of effective edges, and sum of intensities of edges were evaluated. To validate the clinical usefulness, two independent observers graded 100 fundus photographs from subjects with diabetes mellitus before and after image process described above. Agreement between observers and the diagnosis from fluorescein angiography was calculated using Cohen’s kappa coefficient (κ).ResultsThe values of weights for red, green, and blue channels were calculated to be −0.0572, 0.7335, and 2.2079, respectively. When comparing the images that were processed using the new digital filter based on these values with the original image, gray‐scale, green, red, blue, and green and blue digital filter images, the number of edges, effective edges, and sum of intensities of edges were all found to be significantly higher in the images processed with the new filter (p &lt; 10−16). Cohen’s kappa coefficients (κ) of grading diabetic retinopathy from two independent observers comparing to the diagnosis from fluorescein angiography were 0.36, 0.29 respectively from fundus photographs and 0.61, 0.65 respectively from processed images. And Cohen’s kappa coefficients (κ) on the presence of any grade of diabetic retinopathy from two independent observers comparing to the diagnosis from fluorescein angiography were 0.69, 0.69 respectively from fundus photographs and 0.86, 0.84 respectively from processed images.ConclusionsThe RGB filter developed here was based on actual fundus images. The hemo‐globin absorbance reinforced the edges of retinal blood vessels, verifying that the new RGB filter can en‐hance the visualization of retinal vasculature. Significance: This digital filter was developed targeting hemoglobin for enhancement of retinal vasculature. Because this digital filter is simple to build, it can be applied for fundus camera.

Impact study of polarized light on the eye in a experimental model of dry eye disease

AbstractNow dry eye disease (DED) influences each tenth inhabitant of the planet. Current question of modern ophthalmology are the search for new therapies, one of which is the application of BIOPTRON‐PILER therapy.PurposeTo study of pathophysiological mechanisms of action and clinical efficacy of poly‐ and monochromatic BIOPTRON‐PILER‐light of dry eye disease.MethodsHere, we used rats with an experimental model of the dry eye induced by inflammation of eye anterior surface. BIOPTRON‐PILER therapy was performed using the red filter of the BIOPTRON (Bioptron AG, Zepter Group, Swiss) at 1 day after induction of DED. Only the right eye was treated from the distance of 30 cm for 3 min. Each animal received a course of treatment for 10 days.ResultsAre showed that a fluorescein test carried out immediately after alkali application and on 1, 5 and 10 days demonstrated a gradual increase in corneal epithelization and vascularization. We observed substantial and statistically significant increase of lacrimation in experimental rats on a 1 day after induction of inflammation compared to naïve animals. By the 7 day, the lacrimation decreased to a level with subsequent tendency to further decreased tear production. At the same time, there was no significant reduction in tear production on 7th day in a group of rats with the anterior surface inflammation that received polarized red light treatment, which may indicate a possible anti‐inflammatory effect of such treatment.ConclusionObtained evidence of the positive anti‐inflammatory effect of BIOPTRON‐PILER‐light in experimental model of the dry eye disease.

Performance evaluation of locally produced ceramic filters for household water treatment in Nigeria

This study investigates the production of ceramic water filters from various clay materials and their performances to improve the physical and bacteriological quality of drinking water. Ceramic water filters were prepared by combining clay with sawdust at various ratios. The water absorption rate, flow rate and microbial removal efficiency were analyzed. The results indicated that some clays produced from Ire Ekiti Brown clay at ratio 50:50 and 40:60, Ire Ekiti Red clay at ratio 40:60 and 30:70 and Isan Ekiti Brown clay at ratio 40:60 and 30:70 all have high absorption rates which resulted from the high sawdust content in the mixture; as sawdust possesses high porosity. Also, filters produced ranging from 60:40 to 40:60, 50:50 to 40:60 and 70:30 to 40:60 for Ire Ekiti brown clay sample, Ire Ekiti red clay sample and Igbara Odo Ekiti clay sample respectively and for both Ikere Ekiti white clay and Ara Ekiti clay samples at 40:60 all showed better microbial removal efficiency as they could remove more than 95% of coliform bacteria and Escherichia coli. The Ire Ekiti Brown ceramics filter was considered suitable for producing filter materials based on a recipe combination which varies from 60:40 - 40:60. Ire Ekiti Red and Igbara Odo Ekiti Brown ceramics pot filters both recorded a high flow rate owing to the high porosity of their filter components which is as a result of the higher percentage of the constituents of burn-out material. Of all the ceramic filter produced, 50% to 50% ratio of Igbara odo clay to sawdust gave the best and optimum mix which was found to be highly efficient in the removal of microbes in the water sampled. This research reveals the ability of the ceramic filters made principally from locally available materials (clay and sawdust) for microbial removal in wastewater biotreatment.

The OTELO survey

Context. The evolution of galaxies through cosmic time is studied observationally by means of extragalactic surveys. The usefulness of these surveys is greatly improved by increasing the cosmological volume, in either depth or area, and by observing the same targets in different wavelength ranges. A multi-wavelength approach using different observational techniques can compensate for observational biases. Aims. The OTELO survey aims to provide the deepest narrow-band survey to date in terms of minimum detectable flux and emission line equivalent width in order to detect the faintest extragalactic emission line systems. In this way, OTELO data will complements other broad-band, narrow-band, and spectroscopic surveys. Methods. The red tunable filter of the OSIRIS instrument on the 10.4 m Gran Telescopio Canarias (GTC) is used to scan a spectral window centred at 9175 Å, which is free from strong sky emission lines, with a sampling interval of 6 Å and a bandwidth of 12 Å in the most deeply explored EGS region. Careful data reduction using improved techniques for sky ring subtraction, accurate astrometry, photometric calibration, and source extraction enables us to compile the OTELO catalogue. This catalogue is complemented with ancillary data ranging from deep X-ray to far-infrared, including high resolution HST images, which allow us to segregate the different types of targets, derive precise photometric redshifts, and obtain the morphological classification of the extragalactic objects detected. Results. The OTELO multi-wavelength catalogue contains 11 237 entries and is 50% complete at AB magnitude 26.38. Of these sources, 6600 have photometric redshifts with an uncertainty δ zphot better than 0.2 (1+zphot). A total of 4336 of these sources correspond to preliminary emission line candidates, which are complemented by 81 candidate stars and 483 sources that qualify as absorption line systems. The OTELO survey results will be released to the public on the second half of 2019.

Amblyopia with Eccentric Fixation: Is Inverse Occlusion Still an Option?

ABSTRACTPurpose: To present a treatment protocol for patients with amblyopia and eccentric fixation who do not respond to conventional occlusion therapy.Material and methods: In this consecutive case series, 11 patients were included (age 3.5 to 5.0), all with mixed amblyopia and eccentric fixation, who had only minor improvement of their visual acuity (VA) despite good compliance with 6 hours/day to full time occlusion of the sound eye for at least 6 months. Visual acuity of amblyopic eyes ranged from 20/50 to 20/400 at the time of initiation of inverse occlusion. Total inverse occlusion of the amblyopic eye was prescribed for 4 to 8 weeks to convert the steady eccentric fixation to wandering fixation. No binocular viewing was allowed. Once the fixation became wandering, the sound eye was occluded day and night and in most patients, a red filter was placed before the amblyopic eye to stimulate foveal fixation. In nine patients, the fixation became central and occlusion of the sound eye was continued without red filter. All children continued full time occlusion until VA failed to improve after two consecutive visits despite good compliance.Results: In nine children, the VA improved to at least 20/32 in the amblyopic eye. The VA of the sound eye did not change.Conclusion: Inverse occlusion is still a valuable option if conventional occlusion appears to be insufficient to improve VA in amblyopic eyes with eccentric fixation. Full time inverse occlusion should be performed until the eccentric point is no longer used for fixation and should be followed with full time occlusion of the sound eye. Placing a red filter before the amblyopic eye may be helpful to stimulate foveal fixation.

High transmittance and deep RGB primary electrochromic color filter for high light out-coupling electro-optical devices

We report a transmittance controllable electrochromic color filter (TCECF) by incorporating new electrochromic leuco dyes and their optimized composition. Each primary color red (R), green (G), and blue (B) electrochromic filter has an excellent transmittance of more than 84% at 650 nm, 540 nm, 450 nm, and the color coordinates are controllable from white (0.332, 0.347) to deep-red (0.621, 0.344), deep-green (0.327, 0.646), and deep-blue (0.179, 0.085), respectively. Also, each TCECF has good coloration efficiencies of 188.7 cm2 C-1 (R), 189.3 cm2 C-1 (G), and 147.8 cm2 C-1 (B) with high optical density change. A full color producible electrochromic color filter (ECF) is designed and fabricated by integrating primary RGB color filters with a refractive index matching adhesive layer. The fabricated three-stack full color producible ECF enables high transmittance of about 61% for clear white light extraction, and it can produce various colors including RGB. This TCECF technology will be very useful for high light out-coupling electro-optical applications, such as smart lighting, smart window, and display.

Visibility and Line‐of‐Sight Extinction Estimates in Gale Crater During the 2018/MY34 Global Dust Storm

AbstractNorthern line‐of‐sight extinction within Gale Crater during the 2018 global dust storm was monitored daily using Mars Science Laboratory's Navcam. Additional observations with Mastcam (north) and Navcam (all directions) were obtained at a lower cadence. Using feature identification and georeferencing, extinction was estimated in all possible directions. Peak extinction of &gt;1.1 km−1 was measured between sols 2086 and 2090, an order of magnitude higher than previous maxima. Northern and western directions show an initial decrease, followed by a secondary peak in extinction, not seen in column opacity measurements. Due to foreground topography, eastern direction results are provided only as limits, and southern results were indeterminable. Mastcam red and green filter results agree well, but blue filter results show higher extinctions, likely due to low signal‐to‐noise. Morning results are systematically higher than afternoon results, potentially indicative of atmospheric mixing.