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Fulltext A Heuristic Approach for Optical Transceiver Placement to Optimize SNR and Illuminance Uniformities of an Optical Body Area Network

Masroor K, Jeoti V, Drieberg M, Cheab S, Rajbhandari S

Sensors (Basel), 2021 Apr 22;21(9).
PMID: 33922288 DOI: 10.3390/s21092943

The bi-directional information transfer in optical body area networks (OBANs) is crucial at all the three tiers of communication, i.e., intra-, inter-, and beyond-BAN communication, which correspond to tier-I, tier-II, and tier-III, respectively. However, the provision of uninterrupted uplink (UL) and downlink (DL) connections at tier II (inter-BAN) are extremely critical, since these links serve as a bridge between tier-I (intra-BAN) and tier-III (beyond-BAN) communication. Any negligence at this level could be life-threatening; therefore, enabling quality-of-service (QoS) remains a fundamental design issue at tier-II. Consequently, to provide QoS, a key parameter is to ensure link reliability and communication quality by maintaining a nearly uniform signal-to-noise ratio (SNR) within the coverage area. Several studies have reported the effects of transceiver related parameters on OBAN link performance, nevertheless the implications of changing transmitter locations on the SNR uniformity and communication quality have not been addressed. In this work, we undertake a DL scenario and analyze how the placement of light-emitting diode (LED) lamps can improve the SNR uniformity, regardless of the receiver position. Subsequently, we show that using the principle of reciprocity (POR) and with transmitter-receiver positions switched, the analysis is also applicable to UL, provided that the optical channel remains linear. Moreover, we propose a generalized optimal placement scheme along with a heuristic design formula to achieve uniform SNR and illuminance for DL using a fixed number of transmitters and compare it with an existing technique. The study reveals that the proposed placement technique reduces the fluctuations in SNR by 54% and improves the illuminance uniformity up to 102% as compared to the traditional approach. Finally, we show that, for very low luminous intensity, the SNR values remain sufficient to maintain a minimum bit error rate (BER) of 10-9 with on-off keying non-return-to-zero (OOK-NRZ) modulation format.

Matched MeSH terms: Light
Fulltext EFFECTS OF DIFFERENTEXPOSURE TIMES OF LED LIGHTS ON POSTHARVEST PERFORMANCES OF FRESH-CUT PINEAPPLE(Ananas comosusL. cv. Josapine)

LEONG JIA Q, WAN ZALIHA WAN SEMBOK

UMT Journal of Undergraduate Research, 2019;1(1):68-79.
MyJurnal

Pineapple is one of the most important commercial fruit crops served in fresh-cut form which is convenientfor the consumers. However, fresh-cut pineapple induces the activity of phenolic compounds which triggers the generation of brown or dark pigments. Browning incidence (BI) directly influences the fruit’s acceptability and marketability. Therefore, different exposure times (5mins, 10mins, 15mins and 20mins)and typesof LED lights (white, red and blue) were applied on fresh-cut pineapple stored at 5oC storage for twelve days to reduce BI. A significant interaction between the two factors was recorded in lightness coefficient, chroma, total phenolic and ascorbic acid (AA)contents. Regardless of exposure times, all types of LED lights, mainly the blue light, succeeded in delaying BI in fresh-cut pineapple. In conclusion, blue light had a tendency todelay BI andmaintaintheother postharvest quality attributes of fresh-cut pineapple.

Matched MeSH terms: Light
Fulltext Car license plate detection method for Malaysian plates-styles by using a web camera

Al-Ghaili, Abbas M., Syamsiah Mashohor, Abdul Rahman Ramli, Alyani Ismail

Pertanika Journal of Science & Technology, 2010;18(2):-.
MyJurnal

Recently, license plate detection has been used in many applications especially in transportation systems. Many methods have been proposed in order to detect license plates, but most of them work under restricted conditions such as fixed illumination, stationary background, and high resolution images. License plate detection plays an important role in car license plate recognition systems because it affects the accuracy and processing time of the system. This work aims to build a Car License Plate Detection (CLPD) system at a lower cost of its hardware devices and with less complexity of algorithms’ design, and then compare its performance with the local CAR Plate Extraction Technology (CARPET). As Malaysian plates have special design and they differ from other international plates, this work tries to compare two likely-design methods. The images are taken using a web camera for both the systems. One of the most important contributions in this paper is that the proposed CLPD method uses Vertical Edge Detection Algorithm (VEDA) to extract the vertical edges of plates. The proposed CLPD method can work to detect the region of car license plates. The method shows the total time of processing one 352x288 image is 47.7 ms, and it meets the requirement of real time processing. Under the experiment datasets, which were taken from real scenes, 579 out of 643 images were successfully detected. Meanwhile, the average accuracy of locating car license plate was 90%. In this work, a comparison between CARPET and the proposed CLPD method for the same tested images was done in terms of detection rate and efficiency. The results indicated that the detection rate was 92% and 84% for the CLPD method and CARPET, respectively. The results also showed that the CLPD method could work using dark images to detect license plates, whereas CARPET had failed to do so.

Matched MeSH terms: Light; Lighting
Extraction and characterization of gelatin from different marine fish species in Malaysia

Irwandi, J., Faridayanti, S., Mohamed, E.S.M., Hamzah, M.S., Torla, H.H., Che Man, Y.B.

International Food Research Journal, 2009;16(3):381-389.
MyJurnal

Gelatins from the skin of four local marine fish, namely “kerapu” (Epinephelus sexfasciatus), “jenahak” (Lutjianus argentimaculatus), “kembung” (Rastrelliger kanagurta), and “kerisi” (Pristipomodes typus) have been successfully extracted by acid extraction. Results characterization showed that the fish gelatins were comparable to the fish gelatins from other fish species previously reported. They appeared snowy white in color with crystal-like and light texture. The gelatine extracted from “kerapu” had the strongest fishy odor, followed by the gelatines derived from “jenahak”, “kembung” and “kerisi”. In terms of bloom strength, the gelatin extracted from “kerapu” was found to be the strongest one compared to others, with the bloom value of more than 2000 g. The gelatins developed in this study contained almost all essential amino acids, with glycine being the most predominant one.

Matched MeSH terms: Light
Fulltext The effect of storage on the quality attributes of ultraviolet-irradiated and thermally pasteurised pineapple juices

Chia, S. L., Rosnah, S., Noranizan, M. A., Wan Ramli, W. D.

International Food Research Journal, 2012;19(3):1001-1010.
MyJurnal

The effect of storage time on the quality of ultraviolet-irradiated and thermally pasteurised pineapple juice was evaluated. The juices were irradiated with ultraviolet light (UV-C) at wavelength 254 nm (53.42 mJ/cm2, 4.918 s), thermally pasteurised at 800C for 10 minutes and stored at 40C for 13 weeks. There were significant changes in the total soluble solids, pH, titratable acidity and turbidity of UV-irradiated juice during storage, whereas for the same quality attributes of thermally pasteurised juice remained stable throughout the storage time. There were no significant changes in total phenolics for both treatments throughout the storage period. Other quality parameters (ascorbic acid, colour L, hue angle and chroma) were significantly affected by the storage time. Regarding the microbiological analysis, the total plate counts and yeast and mould counts of the UV-irradiated juice increased gradually throughout the 13 weeks of storage while these parameters remained unchanged in the thermally pasteurised juice with almost no microorganism growth. UV-irradiated pineapple juice preserved better quality attributes (TSS, pH, titratable acidity, ascorbic acid, turbidity, total phenolic, L (lightness), hue angle and chroma) than the thermal pasteurised juice during the storage time. Hence, UV irradiation has great potential as an alternative technology to thermal pasteurisation in producing products of high nutritive values.

Matched MeSH terms: Light
Fulltext Direct synthesis of nanodiamonds by femtosecond laser irradiation of ethanol

Nee CH, Yap SL, Tou TY, Chang HC, Yap SS

Sci Rep, 2016 Sep 23;6:33966.
PMID: 27659184 DOI: 10.1038/srep33966

Carbon nanomaterials exhibit novel characteristics including enhanced thermal, electrical, mechanical, and biological properties. Nanodiamonds; first discovered in meteorites are found to be biocompatible, non-toxic and have distinct optical properties. Here we show that nanodiamonds with the size of <5 nm are formed directly from ethanol via 1025 nm femtosecond laser irradiation. The absorption of laser energy by ethanol increased non-linearly above 100 μJ accompanied by a white light continuum arises from fs laser filamentation. At laser energy higher than 300 μJ, emission spectra of C, O and H in the plasma were detected, indicating the dissociation of C2H5OH. Nucleation of the carbon species in the confined plasma within the laser filaments leads to the formation of nanodiamonds. The energy dependence and the roles of the nonlinear phenomenon to the formation of homogeneous nanodiamonds are discussed. This work brings new possibility for bottom-up nanomaterials synthesis based on nano and ultrafast laser physics.

Matched MeSH terms: Light
Fulltext Microfluidic systems for dielectrophoretic separation of fluorescent particles

Yunus, N.A.M., Jaafar, H., Halin, I.A., Green, N.G.

ASM Science Journal, 2014;8(1):29-35.
MyJurnal

This paper presents a suitable and unique system for observing dielectrophoretic particle separation in a microfluidic device. Details presented on the experimental setup used will enable real time examination, monitoring and analysis of carboxylate-modified latex sphere particles in a colloidal mixture. Observations of the particles were made possible through an optical setup that illuminates the particles that went through the microelectrode array in the microchannel that was controlled by two analog signal generators. Through the setup, it was easily observed that the latex sphere particles move at a flow rate of 0.2 μl/s without colliding or overlapping on each other and successfully separated in two bands left and right. The new separation of one finest particles size for finest purification with respect to frequency was also observed, obtained and analysed.

Matched MeSH terms: Light; Lighting
Fulltext Physicochemical characteristics and sensory properties of selected Malaysian commercial chicken burgers

International Food Research Journal, 2011;18(4):1349-1357.
MyJurnal

Ten selected brands of commercial chicken burgers were analysed for their proximate composition, texture profiles, colour and sensory properties. Results show commercial chicken burgers consisted of moisture, proteins, fat and ash in the range of 46.72-69.37%, 11.08-18.77%, 9.08-20.54%, and 1.50-2.96%, respectively. Meanwhile, texture profiles comprised of hardness ranging from 8003.25-19038.15g, while chewiness had the value ranging from 650.78-1275.78 g. On the other hands, cohesiveness had the value ranging from 0.223-0.371, while springiness recorded the value in the range from 0.141-0.443. Colour analysis of cooked burgers resulted in lightness (L*) ranging from 48.21-73.59, redness (a*) from 0.75-9.08, and yellowness (b*) from 21.56-31.24. In sensory evaluation, the most acceptable colour of chicken burger was the one which had the medium lightness (L*) with the value of 63.96), medium redness (a*) with the value of 7.00) and the highest yellowness (b*) intensity value at 31.24. In addition, the most acceptable texture was the one with medium hardness value of 12590 g, high chewiness value of 1195.42 g, high cohesiveness value of 0.371, and medium springiness value of 0.254. It can be concluded that the Malaysian commercial chicken burgers complied with the Food Act of Malaysia and contained different levels of chemical compositions, textural characteristics and colour properties.

Matched MeSH terms: Light
Fulltext Green technology and innovative changes

Ahmad Zaidee Laidin, Loganathan, P.

ASM Science Journal, 2011;5(1):77-77.
MyJurnal

Awareness and sensitivity on the subject of green technology are currently commanding the attention of the world in the light of rising energy costs and the threat of global warming. Many countries are now recognizing the benefits of researching into and using green technology to reduce their carbon and water footprints and to minimize waste. (Copied from article).

Matched MeSH terms: Light
Fulltext Optical tomography: real time image reconstruction for various flow regimes in gravity flow conveyor

Abdul Rahim, R., Pang, J.F., Chan, K.S., Leong, L.C., Fazalul Rahiman, M.H.

ASM Science Journal, 2007;1(1):27-36.
MyJurnal

In this study, real-time imaging was monitored for flowing solid particles when various baffles were created to block certain areas of the pipe. The generated flow regimes were full-flow, three-quarter-flow, half-flow and quarter-flow. A vertical pneumatic conveyor was designed to hold a 85 mm inner diameter pipeline. The four projection optical tomography systems used, applied the parallel beam projection approach and use infrared light sources so that the sensor was free of noise from the surrounding visible light source. The two orthogonal and two rectilinear projections were axial, but ideally they should have been in the same layer. The sensor readings could be related to the varying light intensity effects of the dropping particles and were used to provide cross-sectional distribution information for the conveyor. By using computer programming, the information was reconstructed to produce coloured images and concentration was obtained by reference to a colour code. The results obtained from this study showed how imaged flow followed the artificial flow regime. This study could benefit industrial production lines in maintaining the desired flow rates.

Matched MeSH terms: Light
Raman spectroscopy and X-ray photo-spectroscopy analysis of graphite media irradiated at low doses

Bradley DA, Siti Rozaila Z, Khandaker MU, Almugren KS, Meevasana W, Abdul Sani SF

Appl Radiat Isot, 2019 May;147:105-112.
PMID: 30852298 DOI: 10.1016/j.apradiso.2019.02.016

We explore the utility of controlled low-doses (0.2-100 Gy) of photon irradiation as initiators of structural alteration in carbon-rich materials. To-date our work on carbon has focused on β-, x- and γ-irradiations and the monitoring of radiotherapeutic doses (from a few Gy up to some tens of Gy) on the basis of the thermoluminescence (TL) signal, also via Raman and X-ray photo-spectroscopy (XPS), providing analysis of the dose dependence of single-walled carbon nanotubes (SWCNT). The work has been extended herein to investigate possibilities for analysis of structural alterations in graphite-rich mixtures, use being made of two grades of graphite-rich pencil lead, 8H and 2B, both being in the form produced for mechanical pencils (propelling or clutch pencils). 2B has the greater graphite content (approaching 98 wt %), 8H being a mixture of C, O, Al and Si (with respective weight percentages 39.2, 38.2, 9.8 and 12.8). Working on media pre-annealed at 400 °C, both have subsequently been irradiated to penetrating photon-mediated doses. Raman spectroscopy analysis has been carried out using a 532 nm laser Raman spectrometer, while for samples irradiated to doses from 1 to 40 Gy, XPS spectra were acquired using Al Kα sources (hv ∼1400 eV); carbon KLL Auger peaks were acquired using 50 eV Pass Energy. At these relatively low doses, alterations in order-disorder are clearly observed, defect generation and internal annealing competing as dominating effects across the dose range.

Matched MeSH terms: Light
Generation of novel n-p-n (CeO2-PPy-ZnO) heterojunction for photocatalytic degradation of micro-organic pollutants

Rajendran S, Hoang TKA, Trudeau ML, Jalil AA, Naushad M, Awual MR

Environ Pollut, 2022 Jan 01;292(Pt B):118375.
PMID: 34656681 DOI: 10.1016/j.envpol.2021.118375

Recently, hetero junction materials (p-n-p and n-p-n) have been developed for uplifting the visible light activity to destroy the harmful pollutants in wastewater. This manuscript presents a vivid description of novel n-p-n junction materials namely CeO2-PPy-ZnO. This novel n-p-n junction was applied as the photocatalyst in drifting the mobility of charge carriers and hence obtaining the better photocatalytic activity when compared with p-n and pure system. Such catalyst's syntheses were successful via the copolymerization method. The structural, morphological and optical characterization techniques were applied to identify the physio-chemical properties of the prepared materials. Additionally, the superior performance of this n-p-n nanostructured material was demonstrated in the destruction of micro organic (chlorophenol) toxic wastes under visible light. The accomplished ability of the prepared catalysts (up to 92% degradation of chlorophenol after 180 min of irradiation) and their profound degradation mechanism was explained in detail.

Matched MeSH terms: Light
Effects of nitrogen/bismuth-doping on the photocatalyst composite of carbon dots/titanium dioxide nanoparticles (CDs/TNP) for enhanced visible light-driven removal of diclofenac

Hui KC, Ang WL, Yahya WZN, Sambudi NS

Chemosphere, 2022 Mar;290:133377.
PMID: 34952025 DOI: 10.1016/j.chemosphere.2021.133377

The present work demonstrates the coupling of titanium dioxide, TiO2 nanoparticles (TNP) with N-doped, Bi-doped, and N-Bi co-doped rice husk-derived carbon dots (CDs) via a facile dispersion method, forming respective photocatalyst composites of CDs/TNP, N-CDs/TNP, Bi-CDs/TNP and N-Bi-CDs/TNP. Characterization analyzes verified the successful incorporation of respective CDs samples into TNP, forming photocatalyst composite with narrowed band gap and quenched photoluminescence intensity. Photocatalytic activity of TNP and the respective composites was investigated for photodegradation of diclofenac (DCF) under both simulated sunlight and natural sunlight irradiation. The as-prepared N-Bi-CDs/TNP composite showed the best photocatalytic performance among all composites, able to completely degrade 5 ppm of DCF within 60 min and 180 min under both types of visible light irradiation, respectively. The N-Bi-CDs/TNP composite also showed a TOC removal efficiency up to 87.63%. N-Bi-CDs, worked as photosensitizer and electron reservoir, contributed to the outstanding photocatalytic activity of N-Bi-CDs/TNP, whereby the recombination was prolonged and light absorption was shifted towards the visible light region. Furthermore, the composite of N-Bi-CDs/TNP also demonstrated good stability and reusability over repeated degradation cycles. The photodegradation of DCF resulted into several intermediates, which were identified from LC-MS analysis. The present work could provide an insight on the application of heteroatoms doped and co-doped carbon dots in semiconductor oxide as high performance photocatalysts.

Matched MeSH terms: Light
Effects of different light source and media on growth and production of phycobiliprotein from freshwater cyanobacteria

Khatoon H, Kok Leong L, Abdu Rahman N, Mian S, Begum H, Banerjee S, et al.

Bioresour Technol, 2018 Feb;249:652-658.
PMID: 29091850 DOI: 10.1016/j.biortech.2017.10.052

The aim of this study was to determine the effect of different light sources and media (wastewater and BBM) on the growth of Pseudanabaena mucicola and its phycobiliprotein production. Results showed that P. mucicola grown in white light using wastewater as medium attributed higher biomass (0.55 g L-1) and when extracted with water, also showed significantly higher (P 

Matched MeSH terms: Light
Chitosan functionalized bismuth oxychloride/zinc oxide nanocomposite for enhanced photocatalytic degradation of Congo red

Ranjithkumar R, Van Nguyen C, Wong LS, Thiruvengadam Nandagopal JG, Djearamane S, Palanisamy G, et al.

Int J Biol Macromol, 2023 Jan 15;225:103-111.
PMID: 36481334 DOI: 10.1016/j.ijbiomac.2022.11.302

The industrial discharge of dye pollutant contaminated wastewater is the major cause of water and soil pollution. Photocatalysis is a promising and green remediation technology, which has received widespread attention in the remediation of hazardous dyes from aqueous environment and convert them into harmless compounds. Herein, we report the synthesis of chitosan (CS) functionalized bismuth oxychloride/zinc oxide (BiOCl/ZnO) nanocomposite by a modified hydrothermal route. The physiochemical characterization revealed that the synthesized nanocomposite have crystalline, agglomerated spherical along with rod shaped morphology and size range from 35 to 160 nm. FTIR peaks at 825, 727, 662 and 622 cm-1 specified the presence of BiO and ZnO bonds, whereas peak at 1635 cm-1 revealed the existence of amine groups which confirms the presence of CS in the synthesized CS-BiOCl/ZnO nanocomposite. Catalytic property of synthesized nanocomposite was evaluated by the degradation of Congo red (CR) under UV-light irradiation. CR dye degradation percentage was found to be 93 % within a short period of 40 min by utilizing UV-light. Furthermore, reusability of CS-BiOCl/ZnO photocatalyst was also investigated, and it remained significant photocatalytic activity after three consecutive cycles. Hence, the results obtained in this study revealed that CS-BiOCl/ZnO nanocomposite can be used as a potential photocatalyst to remediate organic pollutants in various industries.

Matched MeSH terms: Light
Fabrication of Ni/TiO2 visible light responsive photocatalyst for decomposition of oxytetracycline

Park J, Lam SS, Park YK, Kim BJ, An KH, Jung SC

Environ Res, 2023 Jan 01;216(Pt 3):114657.
PMID: 36328223 DOI: 10.1016/j.envres.2022.114657

Nickel-impregnated TiO2 photocatalyst (NiTP) responding to visible light was prepared by the liquid phase plasma (LPP) method, and its photoactivity was evaluated in degrading an antibiotic (oxytetracycline, OTC). For preparing the photocatalyst, nickel was uniformly impregnated onto TiO2 (P-25) powder, and the nickel content increased as the number of LPP reactions increased. In addition, the morphology and lattice of NiTP were observed through various instrumental analyses, and it was confirmed that NiO-type nanoparticles were impregnated in NiTP. Fundamentally, as the amount of impregnated nickel in the TiO2 powder increased sufficiently, the band gap energy of TiO2 decreased, and eventually, the NiTP excited by visible light was synthesized. Further, OTC had a decomposition reaction pathway in which active radicals generated in OTC photocatalytic reaction under NiTP were finally mineralized through reactions such as decarboxamidation, hydration, deamination, demethylation, and dehydroxylation. In effect, we succeeded in synthesizing a photocatalyst useable under visible light by performing only the LPP single process and developed a new advanced oxidation process (AOP) that can remove toxic antibiotics.

Matched MeSH terms: Light
Acoustic evaluation of photobiomodulation effect on in vitro human blood samples

Suardi N, Germanam SJ, Rahim NAYM

Lasers Med Sci, 2023 Apr 14;38(1):99.
PMID: 37059895 DOI: 10.1007/s10103-023-03766-6

Although positive photobiomodulation response on wound healing, tissue repair, and therapeutic treatment has been widely reported, additional works are still needed to understand its effects on human blood. This research carried out acoustic measurements using A-scan (GAMPT) ultrasonic techniques to elucidate the photobiomodulation effects on in vitro human blood samples as therapeutic treatment measures. The human blood samples were irradiated using a 532-nm laser with different output laser powers (60 and 80 mW) at various exposure times. The ultrasonic velocity measured in the human blood samples after laser irradiation showed significant changes, most of which were within the acceptance limit for soft tissues (1570 [Formula: see text] 30 m/s). Abnormal cells (echinocyte and crenation) were observed due to excessive exposure during laser treatment.

Matched MeSH terms: Light
Fulltext Image-based 3D canopy reconstruction to determine potential productivity in complex multi-species crop systems

Burgess AJ, Retkute R, Pound MP, Mayes S, Murchie EH

Ann Bot, 2017 Mar 01;119(4):517-532.
PMID: 28065926 DOI: 10.1093/aob/mcw242

BACKGROUND AND AIMS: Intercropping systems contain two or more species simultaneously in close proximity. Due to contrasting features of the component crops, quantification of the light environment and photosynthetic productivity is extremely difficult. However it is an essential component of productivity. Here, a low-tech but high-resolution method is presented that can be applied to single- and multi-species cropping systems to facilitate characterization of the light environment. Different row layouts of an intercrop consisting of Bambara groundnut ( Vigna subterranea ) and proso millet ( Panicum miliaceum ) have been used as an example and the new opportunities presented by this approach have been analysed.
METHODS: Three-dimensional plant reconstruction, based on stereo cameras, combined with ray tracing was implemented to explore the light environment within the Bambara groundnut-proso millet intercropping system and associated monocrops. Gas exchange data were used to predict the total carbon gain of each component crop.
KEY RESULTS: The shading influence of the tall proso millet on the shorter Bambara groundnut results in a reduction in total canopy light interception and carbon gain. However, the increased leaf area index (LAI) of proso millet, higher photosynthetic potential due to the C4 pathway and sub-optimal photosynthetic acclimation of Bambara groundnut to shade means that increasing the number of rows of millet will lead to greater light interception and carbon gain per unit ground area, despite Bambara groundnut intercepting more light per unit leaf area.
CONCLUSIONS: Three-dimensional reconstruction combined with ray tracing provides a novel, accurate method of exploring the light environment within an intercrop that does not require difficult measurements of light interception and data-intensive manual reconstruction, especially for such systems with inherently high spatial possibilities. It provides new opportunities for calculating potential productivity within multi-species cropping systems, enables the quantification of dynamic physiological differences between crops grown as monoculture and those within intercrops, and enables the prediction of new productive combinations of previously untested crops.

Matched MeSH terms: Light
Hydrothermal synthesis and photocatalytic application of ZnS-Ag composites based on biomass-derived carbon aerogel for the visible light degradation of methylene blue

Shanmugam P, Parasuraman B, Boonyuen S, Thangavelu P, AlSalhi MS, Zheng ALT, et al.

Environ Geochem Health, 2024 Feb 17;46(3):92.
PMID: 38367085 DOI: 10.1007/s10653-024-01871-1

A facile and cost-effective hydrothermal followed by precipitation method is employed to synthesize visible light-driven ZnS-Ag ternary composites supported on carbon aerogel (CA). Extensive studies were conducted on the structural, morphological, and optical properties, confirming the successful formation of ternary nanocomposites. The obtained results evidently demonstrate the successful loading of ZnS and Ag onto the surface of the CA. High-resolution transmission electron microscopy analysis revealed that ZnS and Ag nanoparticles (AgNPs) were uniformly distributed on the surface of the CA with an average diameter of 18 nm. The biomass-derived CA, containing a hierarchical porous nano-architecture and an abundant number of -NH2 functional groups on the surface, can greatly prevent the agglomeration, stability and reduce particle size. Brunauer-Emmett-Teller analysis results indicated specific surface areas of 4.62 m2 g-1 for the CA, 48.50 m2 g-1 for the CA/ZnS composite, and 62.62 m2 g-1 for the CA/ZnS-Ag composite. These values demonstrate an increase in surface area upon the incorporation of ZnS and Ag into the CA matrix. Under visible light irradiation, the synthesized CA/ZnS-Ag composites displayed remarkably improved photodegradation efficiency of methylene blue (MB). Among the tested samples, the CA/ZnS-Ag composites exhibited the highest percentage of photodegradation efficiency, surpassing ZnS, CA, and CA/ZnS. The obtained percentages of degradation efficiency for CA, ZnS, CA/ZnS, and CA/ZnS-Ag composites were determined as 26.60%, 52.12%, 68.39%, and 98.64%, respectively. These results highlight the superior photocatalytic performance of the CA/ZnS-Ag composites in the degradation of MB under visible light conditions. The superior efficiency of the CA/ZnS-Ag composite can be attributed to multiple factors, including its elevated specific surface area, inhibition of electron-hole pair recombination, and enhanced photon absorption within the visible light spectrum. The CA/ZnS-Ag composites displayed consistent efficiency over multiple cycles, confirming their stable performance, reusability, and enduring durability, thereby showcasing the robust nature of this composite material.

Matched MeSH terms: Light
Ultra-short laser pulse generated by a microring resonator system for cancer cell treatment

Jalil MA, Ong CT, Saktioto T, Daud S, Aziz MS, Yupapin PP

Artif Cells Nanomed Biotechnol, 2013 Jun;41(3):152-8.
PMID: 22947143 DOI: 10.3109/10731199.2012.700520

A microring resonator (MRRs) system incorporated with a add/drop filter is proposed in which ultra-short single, multi-temporal, and spatial optical soliton pulses are simulated and used to kill abnormal cells, tumors, and cancer. Chaotic signals are generated by a bright soliton pulse within a nonlinear MRRs system. Gold nanoparticles and ultra-short femtosecond/picosecond laser pulses' interaction holds great interest in laser nanomedicine. By using appropriate soliton input power and MRRs parameters, desired spatial and temporal signals can be generated over the spectrum. Results show that short temporal and spatial solitons pulse with FWHM = 712 fs and FWHM = 17.5 pm could be generated. The add/drop filter system is used to generate the high-capacity, ultra-short soliton pulses in the range of nanometer/second and picometer/second.

Matched MeSH terms: Low-Level Light Therapy/instrumentation*; Low-Level Light Therapy/methods

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