scholarly journals Degradasi Tirosina Menggunakan Mangkinfoto Berasaskan TiO2

2012 ◽  
Author(s):  
Rusmidah Ali ◽  
Siti Salamah Maisoan @ Selamat
Keyword(s):  
Amino Acid ◽  
Metal Ions ◽  
Uv Light ◽  
Degradation Process ◽  
Aqueous System ◽  
Visible Spectroscopy ◽  
Photo Degradation ◽  
Efficient System ◽  
Catalyst Powder ◽  
Uv Visible

Asid amino merupakan bahan asas dalam tisu tumbuhan dan haiwan. Tirosina (Tr) salah satu jenis asid amino yang mengandungi gelang aromatik, telah dipilih sebagai sampel untuk proses degradasi dalam medium akueus. Ini bertujuan melihat kesan penggunaan mangkinfoto dalam sinaran ultralembayung (λ < 400 nm) atau cahaya matahari ke atas molekul tirosina. Kajian telah dijalankan menggunakan sistem cahaya, mangkin serbuk TiO2, hidrogen peroksida, H2O2 dan ion logam. Penambahan ion logam seperti Ni2+, Cu2+, Ag+, Mn2+, Co2+, Fe2+ dan Cd2+ dan agen pengoksidaan, iaitu hidrogen peroksida adalah untuk mendapatkan kaedah yang paling cekap. Keputusan menunjukkan penambahan H2O2 dan ion Fe2+ dan Ni2+ berjaya meningkatkan kecekapan proses degradasifoto tirosina. Ion Ni2+ memberikan keputusan terbaik berbanding ion-ion lain. Ion Cu2+, Ag+, Mn2+ dan Cd2+ merencat proses degradasi. Keputusan juga menunjukkan cahaya matahari adalah setanding dengan cahaya ultralembayung. Kepekatan H2O2 terbaik adalah 5.0 x 10-2M dan semakin banyak TiO2 digunakan semakin baik peratus degradasi tirosina. Oleh itu kaedah optimum untuk proses degradasifoto ialah Tr 2.5 x 10-4 M + TiO2 + H2O25.0 x 10-3 M + Mn+ 1.0 x 10-2 M. Proses degradasifoto dikaji menggunakan spektroskopi ultralembayung-nampak pada julat panjang gelombang 400-200 nm. Kata kunci: Tirosina; degradasifoto; serbuk TiO; akueus Amino acid is a basic component in plant or animal tissue. Tyrosine (Tr), an amino acid which contains aromatic ring, was chosen as a sample for a photodegradation process in an aqueous system. The purpose of the experiment is to study the effect of photocatalysis under UV (λ < 400 nm) or sunlight on tyrosine. The experiment was carried out by using UV light, catalyst powder (TiO2), hidrogen peroxide H2O2 and metal ions system. The addition of oxidising agent H2O2 and metal ions such as Ni2+, Cu2+, Ag+, Mn2+, Co2+, Fe2+ and Cd2+ were used in order to achieve the most efficient system. Results showed that the system with added H2O2 and metal ions such as Ni2+ and Fe2+ had successfully enhanced the process of the tyrosine photodegradation. Other metal ions system such as Cu2+, Ag+, Mn2+ and Cd2+ were found to inhibit the degradation process. The results also showed that sunlight was comparable to ultraviolet light. The best H2O2 concentration was 5.0 x 10-2 M and the percentage of tyrosine degradation increased with the addition of more TiO2) by mass. Therefore, the optimum condition for tyrosine photodegradation process was in Tr 2.5 x 10-4 M + TiO2 + H2O2 5.0 x 10-3 M + H2O2 1.0 x 10-2 M. The dissappearance of tyrosine in the photo degradation process was monitored by UV-visible spectroscopy between 400-200 nm. Key words: Tyrosine; photodegradation; TiO2 powder; akueus

UV Light Stability of α-Cyclodextrin/Resveratrol Host - Guest Complexes and Isomer Stability at Varying pH

2009 ◽  
Vol 62 (8) ◽  
pp. 921 ◽  
Author(s):  
Kerrilee E. Allan ◽  
Claire E. Lenehan ◽  
Amanda V. Ellis
Keyword(s):  
Inclusion Complex ◽  
Uv Light ◽  
Sodium Dodecyl ◽  
Molar Absorptivity ◽  
Photo Degradation ◽  
Light Stability ◽  
Uv Visible ◽  
The Stability ◽  
Ph Range ◽  
Cis Isomer

trans-Resveratrol is an antioxidant that readily isomerizes to the cis isomer under UV irradiation. Here we report on the UV-Visible analysis of the stability of both trans- and cis-resveratrol isomers in the presence of UV light over a pH range of 2.0–9.0 in a phosphate-borate buffer that contains sodium dodecyl sulphate and acetonitrile. The molar absorptivity of the trans-resveratrol solution absorbing at 320 nm (3.88 eV) and 305 nm (4.07 eV) was 33000 and 34000 M–1 cm–1, respectively. Results indicate that trans-resveratrol has a slower isomerization within a pH range of 5.0–8.0. A pH > 8.0 results in almost immediate isomerization of the sample, whereas at pH 2.0 a photo-degradation product appears at 260 nm (4.77 eV). This was not apparent at pH 8.0. By including trans-resveratrol into a trans-resveratrol/α-cyclodextrin host–guest inclusion complex in pH 8.0 buffer isomerization was greatly reduced, with enhanced trans-resveratrol photostability.

scholarly journals Differential surface characterizations of cotton fibers coated with TiO2 and ZnO nanoparticles for nano-based analysis of fabrics

2021 ◽  
Vol 16 ◽  
pp. 155892502110438
Author(s):  
Parshuram Singh ◽  
Sapna Balayan ◽  
Rajendra Kumar Sarin ◽  
Utkarsh Jain
Keyword(s):  
Electron Microscopy ◽  
Uv Light ◽  
Natural Fibers ◽  
Vital Role ◽  
Cotton Fibers ◽  
Visible Spectroscopy ◽  
X Ray ◽  
Uv Visible ◽  
Unit Component ◽  
Scanning Electron

Fibers are the unit component for product development. They can be divided into two types: synthetic and natural fibers. Recently, emerging nanotechnology has played a vital role in advancing next-generation fabrics. The nanomaterials provide several unique properties such as higher conductivity, self-cleaning, water-resistant, and others. Owing to their advanced properties, the fabrics are being developed by coating and integrating with nanomaterials. Therefore, in the presented work two cotton samples were modified with titanium dioxide (TiO2) and zinc oxide (ZnO). These samples were further examined under various techniques including scanning electron microscopy (SEM), UV-visible spectroscopy, X-ray fluorescence (XRF), and Fourier-transform infrared spectroscopy (FTIR). Furthermore, these samples were evaluated at varying wavelengths with UV light and the obtained results demonstrated that the nano-coated fiber samples can be differentiated at 365 nm.

scholarly journals Effect of ultraviolet light on the degradation of Low-Density and High-Density Polyethylene characterized by the weight loss and FTIR

2019 ◽  
Vol 1 (2) ◽  
pp. 26-31
Author(s):  
Prakash Bhuyar ◽  
Nurul Aqilah Binti Mohd Tamizi ◽  
Mohd Hasbi Ab. Rahim ◽  
Gaanty Pragas Maniam ◽  
Natanamurugaraj Govindan
Keyword(s):  
Weight Loss ◽  
High Density Polyethylene ◽  
Uv Light ◽  
Incident Light ◽  
Degradation Process ◽  
Sem Analysis ◽  
Ftir Spectrum ◽  
Physical Treatment ◽  
Photo Degradation ◽  
Vibrational Energies

In this study, the research was made to understand the knowledge widely related to the degradation process of polyethylene polymer. The mode of treatment that involves in the degradation process of polyethylene is physical treatment while the method of degradation used is photo-degradation of UV light. By using the physical treatment of UV irradiation light, it helps by affecting the bonding that holds the polymer together to break and weakens the plastic. From the result obtained in FTIR and SEM analysis, in FTIR spectrum of LDPE shows higher transmittance compared to FTIR spectrum of HDPE both UV-treated for 30 days. This indicates the high transmittance have few bonds to absorb light in the LDPE sample, low transmittance in HDPE sample means has high population of bonds which have vibrational energies corresponding to the incident light. For SEM result, the polyethylene for LDPE plastic sheet shows the best results for degradation and managed to reduce the weight loss at 87.5% compared to HDPE plastic which at 21.6%.

scholarly journals Simultaneous Preparation of Facial and Meridional Isomer of Cobalt-Amino Acid Complexes and their Characterization

2009 ◽  
Vol 2 (1) ◽  
pp. 91-98 ◽  
Author(s):  
M. M. Alam ◽  
S. M. S. Islam ◽  
S. M. M. Rahman ◽  
M. M. Rahman
Keyword(s):  
Amino Acid ◽  
Ir Spectroscopy ◽  
Chemical Analysis ◽  
Sufficient Information ◽  
Carboxyl Group ◽  
Direct Impact ◽  
Acid System ◽  
Visible Spectroscopy ◽  
Uv Visible

Preparation and characterization of various complexes of cobalt (III)-amino acid system, especially cobalt (III) glycinato and cobalt (III) alaninato complexes are reported. The identification of the various isomers of these complexes is also reported. The various isomers are separated from their mixture by fractional crystallization. Each of these complexes has been characterized by observing physical characteristics, chemical analysis, UV-visible spectroscopy and IR-spectroscopy. The direct impact of geometry of the complexes to IR stretching frequencies and UV-visible spectral data of amino and carboxyl group in the complexes provided sufficient information about the geometry. A prediction about the geometries of the synthesized has also been focused.   Keywords: Cobalt; Amino acid; Isomers; UV-visible; IR. © 2010 JSR Publications. ISSN: 2070-0237 (Print); 2070-0245 (Online). All rights reserved.  DOI: 10.3329/jsr.v2i1.2032                 J. Sci. Res. 2 (1), 91-98 (2010)    

Preparation and Optoelectronic Properties of In2O3 Microtubes

2014 ◽  
Vol 936 ◽  
pp. 123-126
Author(s):  
Shuai Chen ◽  
Yun Ze Long ◽  
Hong Di Zhang ◽  
Shu Liang Liu ◽  
Ling Zhi Liu ◽  
...  
Keyword(s):  
Uv Light ◽  
Optoelectronic Properties ◽  
Outer Diameter ◽  
X Ray Diffraction ◽  
Visible Spectroscopy ◽  
Strong Response ◽  
X Ray ◽  
Inner Diameter ◽  
Uv Visible ◽  
Scanning Electron

Ultrathin indium oxide (In2O3) microtubes were successfully fabricated by electrospinning, magnetron sputtering and followed calcination. The hollow In2O3tubes were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD) and UV-visible spectroscopy. Outer diameter of the microtubes was in the range of 700-900 nm, and inner diameter was about 400-600 nm. Optoelectronic properties of the In2O3tubes were investigated by irradiation of UV light with different wavelengths (254, 308 and 365 nm). It was found that the In2O3microtubes had a fast and strong response to UV irradiation.

scholarly journals Synthesis and Characterization of some Mixed Ligand Complexes Containing (8-hydroxyquinoline) and (2 - picoline) with some Metal Ions

2013 ◽  
Vol 10 (2) ◽  
pp. 396-404
Author(s):  
Baghdad Science Journal
Keyword(s):  
Magnetic Susceptibility ◽  
Metal Ions ◽  
Molar Conductivity ◽  
Mixed Ligand ◽  
Synthesis And Characterization ◽  
Conductivity Measurements ◽  
Visible Spectroscopy ◽  
Ft Ir ◽  
Uv Visible

Complexes of some metal ions ( Mn(I? ) , Co(??) , Ni(??) ,Cu (??) , Zn(I?) , Cd (??) , and Hg(??) ) with 8-hydroxyquinoline (Oxine) and 2- Picoline (2-pic ) have been synthesized and characterized on the basis of their FT-IR. and Uv-visible spectroscopy ,atomic absorption molar conductivity measurements and magnetic susceptibility ,from the results obtained the following general formula has been given for prepared complexes [M (oxine)2 (2-pic)2]where M = M(??) = Mn , Co , Ni , Cu , Zn , Cd , Hg(oxine)- = ionic ligand 8-hydroxyquinolin (oxinato)(2- pic) = 2- picoline

scholarly journals Preliminary Characterization of Melanin Isolated from Fruits and Seeds of Nyctanthes arbor-tristis

2009 ◽  
Vol 1 (3) ◽  
pp. 655-661 ◽  
Author(s):  
P. Kannan ◽  
D. Ganjewala
Keyword(s):  
Ir Spectroscopy ◽  
Metal Ions ◽  
Ir Spectrum ◽  
Alkaline Extraction ◽  
Visible Spectroscopy ◽  
Tissue Weight ◽  
Different Temperatures ◽  
Uv Visible ◽  
The Stability

Melanin from Nyctanthes arbor-tristis fruits and seeds was isolated and purified by alkaline extraction, acid hydrolysis and organic solvents. Each, fruit and seed yielded melanin 50 mg/100g tissue weight. The melanins of fruit and seeds were analyzed by UV-visible and infrared (IR) spectroscopy for characterization. The IR spectrum of fruit and seed melanins did not match with each other and the seed melanin could be distinguished by their sharp peat at 285 nm from the fruit melanin in IR spectrum. Two melanins have shown absorptions above and below 1600 cm-1 in their respective IR spectrum. The melanins thus characterized were tested for their stability after incubating at different temperatures and in presence of oxidants (KMnO4 and K2Cr2O7) and metal ions (Mg++ and Zn++) for a specified period. The stability of the melanin was assessed by measuring changes in the absorbance at 285 nm. The results revealed that the fruit melanin was more stable at 50 ºC while the seed melanin was quite stable at 25 ºC. However, their stability was markedly affected by oxidants and metal ions.  Keywords: Melanin; Nyctanthes arbor-tristis; UV-visible spectroscopy; IR-spectroscopy; Oxidant. © 2009 JSR Publications. ISSN: 2070-0237 (Print); 2070-0245 (Online). All rights reserved. DOI: 10.3329/jsr.v1i3.2005               J. Sci. Res. 1 (3), 655-661 (2009)  

scholarly journals Correlation for Photocatalytic Degradation Kinetics of Carboxylic Acids using Electrochemically Synthesized Al2S3 Nanoparticles and Study of Antibacterial Activity

2020 ◽  
Vol 32 (6) ◽  
pp. 1443-1450
Author(s):  
H.C. Charan Kumar ◽  
R. Shilpa ◽  
Sannaiah Ananda
Keyword(s):  
Antibacterial Activity ◽  
Carboxylic Acids ◽  
Uv Light ◽  
Degradation Kinetics ◽  
Visible Region ◽  
Volumetric Method ◽  
Isokinetic Temperature ◽  
Visible Spectroscopy ◽  
Tauc Plot ◽  
Uv Visible

Aluminium sulfide (Al2S3) nanoparticles were successfully synthesized by electrochemical method. Further, the synthesized nanoparticles were used as a photocatalyst for degradation of trichloroacetic acid, chloroacetic acid, acetic acid and degradation kinetics was studied by volumetric method using NaOH under various experimental conditions. The Al2S3 nanoparticles were characterized by UV-visible spectroscopy, X-ray diffraction and SEM-EDAX. The study of UV-visible spectroscopy indicates that Al2S3 nanoparticles shows maximum intensity peak at 222 nm in the UV region and there is no absorption peak in the visible region, therefore the synthesized nanoparticles is active under UV light and band gap energy was found to be 3.07 eV, which was calculated using Tauc plot. The structure of Al2S3 was found to be tetragonal structure and average crystal size was found to be 25.76 nm, which was calculated using Debye-Scherrer′s formula. The SEM results showed that Al2S3 appears as nanoflakes with agglomerated. The presence of aluminium and sulfur was confirmed using EDAX spectra. The photocatalytic activity of the synthesized Al2S3 nanoparticles was examined by taking three carboxylic acids by volumetric method. Taft LFER was tested, the isokinetic temperature β was calculated for oxidation of carboxylic acids. The antibacterial activity was investigated for synthesized nanoparticles by using Bacillus subtilis MTCC 2763 and Escherichia coli MTCC 40 of different bacteria.

scholarly journals Wet Synthesis of Elongated Hexagonal ZnO Microstructures for Applications as Photo-Piezoelectric Catalysts

Materials ◽  
2020 ◽  
Vol 13 (13) ◽  
pp. 2938 ◽  
Author(s):  
Rosanna Pagano ◽  
Chiara Ingrosso ◽  
Gabriele Giancane ◽  
Ludovico Valli ◽  
Simona Bettini
Keyword(s):  
Uv Light ◽  
Low Cost ◽  
Renewable Energy Sources ◽  
Degradation Process ◽  
Blue Dye ◽  
Present Contribution ◽  
Wurtzite Phase ◽  
Photo Degradation ◽  
Uv Photons ◽  
Wet Synthesis

It is well known that energetic demand and environmental pollution are strictly connected; the side products of vehicle and industrial exhausts are considered extremely dangerous for both human and environmental health. In the last years, the possibility to simultaneously photo-degrade water dissolved pollutants by means of ZnO nanostructures and to use their piezoelectric features to enhance the photo-degradation process has been investigated. In the present contribution, an easy and low-cost wet approach to synthetize hexagonal elongated ZnO microstructures in the wurtzite phase was developed. ZnO performances as photo-catalysts, under UV-light irradiation, were confirmed on water dissolved methylene blue dye. Piezoelectric responses of the synthetized ZnO microstructures were evaluated, as well, by depositing them into films onto flexible substrates, and a home-made layout was developed, in order to stimulate the ZnO microstructures deposited on solid supports by means of mechanical stress and UV photons, simultaneously. A relevant increment of the photo-degradation efficiency was observed when the piezopotential was applied, proposing the present approach as a completely eco-friendly tool, able to use renewable energy sources to degrade water solved pollutants.

scholarly journals Efficiency for Sorption Behaviour of Polymeric Resins of (2-hydroxybenzaldehyde) with Aliphatic and Aromatic Diamines Towards Different Metal Ions

2017 ◽  
Vol 60 (3) ◽  
pp. 128-133
Author(s):  
Ambreen Shah ◽  
Asif Ali Shah ◽  
Sobia Shafaq [email protected] Shah
Keyword(s):  
Thermal Analysis ◽  
Metal Ions ◽  
Metal Uptake ◽  
Thermodynamic Quantity ◽  
Visible Spectroscopy ◽  
Aromatic Diamines ◽  
Sorption Behaviour ◽  
Ft Ir ◽  
Uv Visible ◽  
Polymeric Resins

Aliphatic and aromatic polymeric resins of (2-hydroxybenzaldehyde) with 1,2-propylenediamineand 1,4-phenylenediamine were synthesised and characterised employing elemental and thermal analysis,FT-IR and UV-visible spectroscopy. The metal uptake behaviour of synthesised polymers (PMBHBPn,PMBHBPh) towards different metal ions were investigated and optimised by variety of conditions. Thesorption data of these metal ions were followed Langmuir, Freundlich, and Dubinin-Radushkevich(D-R) isotherms. The Freundlich parameters were computed at 1/n = 0.26 ± 0.02, 0.309 ± 0.02, 0.35 ±0.05, 0.368 ± 0.04 and 0.23 ± 0.01, A = 3.9 ± 0.03, 4.31 ± 0.02, 4.683 ± 0.01, 5.43 ± 0.03, and 2.81 ± 0.05mmol/g for Cu(II), Co(II), Ni(II), Fe(III) and Cd(II) ions, respectively. The variation of sorptionwith temperature gives thermodynamic quantity (DH) in the range of (AH = 36.33 - 52.14 KJ/mol) for(PMBHBPn) and (39.21-56.29 KJ/mol) for (PMBHBPh). The sorption procedure could preconcentratemetal ions, and it can be determined by atomic absorption spectrophotometer.

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