wavelength absorption
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2021 ◽  
pp. 116687
Author(s):  
Jean Boulvert ◽  
Thomas Humbert ◽  
Vicente Romero-García ◽  
Gwénaël Gabard ◽  
Edith Roland Fotsing ◽  
...  

2021 ◽  
Vol 945 (1) ◽  
pp. 012034
Author(s):  
Jin Han Tan ◽  
Jin Chung Sin ◽  
Sze Mun Lam

Abstract The palm oil industry generated thick brownish liquid waste known as POME (palm oil mill effluent). POME is one of the wastes that can seriously threaten the survival of aquatic life if discharged untreated. In this study, efficient photocatalytic degradation of POME by CuFe2O4 decorated on BiOCl (BiOCl/CuFe2O4) was reported. The Z-scheme BiOCl/CuFe2O4 composite was successfully fabricated via a precipitation-hydrothermal method. The fourier-transform infrared spectroscopy (FTIR) result clearly displayed the presence of BiOCl and CuFe2O4 in the composite photocatalyst. Compared to pure BiOCl, the composite photocatalyst demonstrated a redshift in the wavelength absorption and great visible light absorbing ability. The photodegradation experiments indicated that the BiOCl/CuFe2O4 demonstrated exceptional POME degradation and decolourization efficiencies of 60% and 68%, respectively after 720 min illumination when compared to the single-phase component photocatalysts. The photocatalytic enhancement of BiOCl/CuFe2O4 can be attributed to the efficient charge carrier separation via the Z-scheme heterojunction.


2021 ◽  
Vol 16 (1) ◽  
Author(s):  
Shubi Zhao ◽  
Yiqun Luo ◽  
Zong Chang ◽  
Chenchen Liu ◽  
Tong Li ◽  
...  

AbstractThe second near infrared window is considered to be the optimal optical window for medical imaging and therapy as its capability of deep tissue penetration. The preparation of the gold nanorods with long wavelength absorption and low cytotoxicity is still a challenge. A series gold nanorods with large aspect ratio have been synthesized. Strong plasma absorption in the second near infrared window from 1000 to 1300 nm could be observed. The biocompatibility of the synthesized gold nanorods is dramatically improved via coating by bovine serum albumin (BSA), while the optical properties of which remains. The breast cancer tumor-bearing mouse could be well treated by the prepared gold nanorods with the NIR-II light intensity as low as 0.75 W/cm2. In summary, these results demonstrate the feasibility of using low illumination dose to treat tumor in the NIR-II region via the large aspect ratio gould nanoparticles.


2021 ◽  
Author(s):  
Joshua Lothringer ◽  
David Sing ◽  
Zafar Rustamkulov ◽  
Hannah Wakeford ◽  
Kevin Stevenson ◽  
...  

Abstract Aerosols have been found to be nearly ubiquitous in substellar atmospheres. Evidence for the composition and conditions whereby these aerosols form remains limited (Cushing et al. 2006, Saumon & Marley 2008, Burningham 2021). Theoretical models and observations of muted spectral features suggest that silicate clouds play an important role in exoplanets between at least 950 and 2,100 K (Gao et al. 2020). However, some giant planets are thought to be hot enough to avoid condensation of even the most refractory elements (Lothringer et al. 2018, Kitzmann et al. 2018). Here, we present the near-UV transmission spectrum of an ultra-hot Jupiter WASP-178b (~2,450 K), that exhibits significant NUV absorption indicating the presence of gaseous refractory elements in the middle atmosphere. This short-wavelength absorption is among the largest spectral features ever observed in an exoplanet in terms of atmospheric scale heights. Bayesian retrievals indicate the broadband UV feature on WASP-178b is caused by refractory elements including silicon and magnesium bearing species, which are the precursors to condensate clouds at lower temperatures. Silicon in particular has not been detected in exoplanets before, but the presence of SiO in WASP-178b is consistent with theoretical expectation as the dominant Si-bearing species at high temperatures. These observations allow us to re-interpret previous observations of HAT-P-41b and WASP-121b to suggest that silicate cloud formation begins on exoplanets with equilibrium temperatures between 1,950 and 2,350 K.


2021 ◽  
Vol 2103 (1) ◽  
pp. 012152
Author(s):  
V A Klinkov

Abstract Advanced for the infrared region of the spectrum chalcogenide glass composition As30.5S44.5I25 with small germanium additives were investigated. The concentration dependences of some physical and chemical properties indicate an increase in the performance of glasses due to the modification of the glass network. The character of the change in the short-wavelength absorption edge with an increase in the content of germanium atoms had an exponential character, shifting from 597 to 582 nm. A non-monotonic dependences were also found for the values of density, refractive index, and glass transition temperature. A joint analysis of the results obtained and structural studies described in the literature for similar glass systems made it possible to propose possible structural groups of glass compositions under investigation.


2021 ◽  
Author(s):  
Anna Ryś ◽  
Lucyna Samek

Abstract. The evaluation of black carbon (BC) sources is very important, especially in environmental sciences. This study shows how the contributions of biomass burning and fossil fuel/traffic to PM2.5 mass can be assessed. MABI was used for this purpose and gave the possibility to measure the transmission of light at different wavelengths. Absorption coefficients were calculated from measurements data and recalculated for concentrations of eBC. The samples of PM2.5 fraction were collected from February 1, 2020 to March 27, 2021 every third day in Krakow, Poland (50°04' N, 19°54'47" E). The concentrations of equivalent BC (eBC) from fossil fuel/traffic and biomass burning were in the range 0.82–11.64 μg m−3) and 0.007–0.84 μg m−3, respectively. At the same time, PM2.5 concentrations varied from 3.14 to 55.24 μg m−3. It means that about 18 % of PM2.5 mass belongs to eBC and 11.3 % of this value comes from biomass burning. The eBC contribution is the significant part of PM2.5 mass and we observed seasonal variation of the eBC concentration during the year with the peak in winter. The contribution of biomass burning to PM2.5 mass is more stable during the whole year. The eBC concentration during workdays is a bit higher than during weekend days but biomass burning is similar for both days (work and weekend taken as the mean for the whole period).


Crystals ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 1103
Author(s):  
Abdulrahman A. Alsimaree ◽  
Omar M. Alatawi ◽  
Paul G. Waddell ◽  
David P. Day ◽  
Nawaf I. Alsenani ◽  
...  

Two new pyrrolylquinoline-substituted heteroaromatic-containing compounds bearing a central boron bridge have been prepared by a short, high-yielding sequence consisting of Suzuki-coupling of 8-bromoquinoline and N-Boc 2-pyrroleboronic acid, thermolytic tert-butyloxycarbonyl deprotection, and subsequent boron chelation (either using boron trifluoride or triphenylborane). Both derivatives display longer wavelength absorption maxima (λabsmax) than a previously reported indolopyridine-BPh2 analogue, in agreement with the smaller HOMO-LUMO energy gap predicted by DFT quantum chemical calculations. Both of the pyrrolylquinoline-boron chelates display weak emission (quantum yields 0.3–0.9%) and the BPh2 complex displays a very broad, long-wavelength emission (λemmax = 715 nm, MeCN), which may be due to dimer emission and results in a large pseudo-Stokes’ shift (7753 cm−1) for this compound.


2021 ◽  
Vol 10 (3) ◽  
pp. 395-402
Author(s):  
Septi Beladini ◽  
A.B. Susanto ◽  
Ali Ridlo

Paparan sinar ultraviolet yang terus menerus dapat menyebabkan kerusakan pada kulit. Upaya pencegahan dapat dengan menggunakan sediaan krim tabir surya. Rumput laut K. alvarezii adalah salah satu organisme laut yang diduga mengandung senyawa yang dapat dijadikan sebagai agen tabir surya alami. Tujuan dari penelitian ini adalah mengetahui karakteristik krim tabir surya dari ekstrak K. alvarezii. Sampel yang digunakan pada penelitian ini adalah rumput laut K. alvarezii kering yang diperoleh dari PT. Rumah Rumput Laut, Bogor. Rumput laut K. alvarezii diekstraksi dengan pelarut yaitu n-heksana, etil asetat, metanol Krim tabir surya dibuat menurut Mishara, (2018), dengan menambahkan empat ekstrak rumput laut K. alvarezii yang berbeda, kemudian dilakukannya uji yang meliputi uji organoleptik, uji stabilitas, uji tipe emulsi, uji clycling test, uji nilai pH, uji nilai SPF,. Hasil penelitian menunjukkan keempat ekstrak K. alvarezii memiliki serapan panjang gelombang pada daerah ultraviolet, untuk hasil analisis sediaan krim tabir surya menunjukkan krim tabir surya dari ekstrak K. alvarezii stabil secara fisik selama penyimpanan 28 hari, tidak ada perubahan warna dan bau, tidak terdapat pertumbuhan jamur, tipe emulsi  krim minyak dalam air dan memiliki nilai SPF >15 sehingga termasuk dalam kategori tabir surya ultra  Continuous exposure to ultraviolet rays can cause damage to the skin. Prevention efforts can use sunscreen cream preparations.seaweed K. alvarezii is a marine organism that is thought to contain compounds that can be used as natural sunscreen agents. The purpose of this study was to determine the characteristics of the sunscreen cream fromextract K. alvarezii. The sample used in this study was theseaweed K. alvarezii driedobtained from PT. Seaweed House, Bogor.seaweed was K. alvarezii extracted with solvents, namely n-hexane, ethyl acetate, methanol and distilled water. Sunscreen cream made, by adding four seaweed extract K. alvarezii different, then do a test covering the organoleptic test, stability test, test emulsion type,test clyclingtest, test the pH value, test the SPF value, . The results showed that the four extracts of K. alvarezii had wavelength absorption in the ultraviolet area, for the analysis of sunscreen cream preparations showed that the sun cream fromextract K. alvarezii was physically stable during 28 days of storage, no change in color and odor, no growth. fungus, a type of oil-in-water cream emulsion and has an SPF value of> 15 so it is included in the ultra sunscreen category. 


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