Journal articles on the topic 'Absorption'
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1
Pulungan, Ainil Fithri, Effendy DLP., and Siti MS. "Simultaneous Spectrophotometric Determination of Paracetamol, Propyphenazone and Caffeine By Using Absorption Ratio Method." Asian Journal of Pharmaceutical Research and Development 6, no. 5 (October 18, 2018): 5–8. http://dx.doi.org/10.22270/ajprd.v6i5.412.
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The Absorption Ratio method involves measuring the absorbance at two wavelengths, namely the iso-absorptive point and the maximum wavelength. Its method could be an option in determining the level of a drug. The aim of this study was to determine whether the absorption ratio method can be used to determine the levels of paracetamol (PCT), propyphenazone (PRO) and caffeine (CAF) in tablet form. The absorption ratio method was used to determine the levels of the mixed drug compound without the separation stage and using the maximum wavelength and iso-absorptif point. The result of the study showed that the absorption ratio method used to solve multicomponent problems in tablet form can be performed and satisfy the validation requirements of the method according to international Conference on Harmonization Q2 (R1) (ICH) guidelines. The absorption ratio method was a simple and accurate to be used determine PCT, PRO, CAF in tablet form.
Keywords : Paracetamol, propyphenazone, caffeine, absorption ratio
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Pongayi Ponnusamy Selvi and Rajoo Baskar, Pongayi Ponnusamy Selvi and Rajoo Baskar. "Mass Transfer Enhancement for CO2 Absorption in Structured Packed Absorption Column." Journal of the chemical society of pakistan 41, no. 5 (2019): 820. http://dx.doi.org/10.52568/000803/jcsp/41.05.2019.
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The acidic gas, Carbon dioxide (CO2) absorption in aqueous ammonia solvent was carried as an example for industrial gaseous treatment. The packed column was provided with a novel structured BX-DX packing material. The overall mass transfer coefficient was calculated from the absorption efficiency of the various runs. Due to the high solubility of CO2, mass transfer was shown to be mainly controlled by gas side transfer rates. The effects of different operating parameters on KGav including CO2 partial pressure, total gas flow rates, volume flow rate of aqueous ammonia solution, aqueous ammonia concentration, and reaction temperature were investigated. For a particular system and operating conditions structured packing provides higher mass transfer coefficient than that of commercial random packing.
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Kulish, M. R. "Influence of absorption saturation on the shape of CdSe absorption edge." Semiconductor Physics Quantum Electronics and Optoelectronics 17, no. 4 (November 10, 2014): 349–52. http://dx.doi.org/10.15407/spqeo17.04.349.
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Li, Ming Fu, Zhi Kai Zhuang, Jin Zhang, Gan Ran Deng, Wen Wei Lian, Jun Yan He, and Tao Huang. "Study on Undegummed Pineapple Leaf Fibers’ Moisture Absorptions." Advanced Materials Research 1048 (October 2014): 66–71. http://dx.doi.org/10.4028/www.scientific.net/amr.1048.66.
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Programmable constant-temperature/humidity test chamber owned by Natural Fiber Laboratory, Institute of Agricultural Machinery, Chinese Academy of Tropical Agricultural Sciences, is adopted to analyze undegummed pineapple fibers’ moisture absorptions. Study and analysis on moisture absorptions, moisture-absorption isothermsand moisture-absorption isohumes with constant temperature and inconstant humidities are carried out and the results show that fibers’moisture absorptions present roughly a regularity of such three stages as 0~20%, 20~80% and 80~100% (RH). In low-moisture stage, moisture absorption rates are higher; in middle-moisture stage, they level off; in high- moisture stage, moisture absorption rates are the highest. Fibers’moisture absorption amounts decrease along with temperature rise; but under the condition of high humidity, they increase along with temperature rise and also increase along with humidity rise. Study on undegummed pineapple fibers’moisture absorptions may provide theoretical basis for undegummed pineapple fiber preservation and textile processing in some special industries.
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Lampel, Johannes, Johannes Zielcke, Stefan Schmitt, Denis Pöhler, Udo Frieß, Ulrich Platt, and Thomas Wagner. "Detection of O<sub>4</sub> absorption around 328 and 419 nm in measured atmospheric absorption spectra." Atmospheric Chemistry and Physics 18, no. 3 (February 6, 2018): 1671–83. http://dx.doi.org/10.5194/acp-18-1671-2018.
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Abstract. Retrieving the column of an absorbing trace gas from spectral data requires that all absorbers in the corresponding wavelength range are sufficiently well known. This is especially important for the retrieval of weak absorbers, whose absorptions are often in the 10−4 range. Previous publications on the absorptions of the oxygen dimer O2–O2 (or short: O4) list absorption peaks at 328 and 419 nm, for which no spectrally resolved literature cross sections are available. As these absorptions potentially influence the spectral retrieval of various trace gases, such as HCHO, BrO, OClO and IO, their shape and magnitude need to be quantified. We assume that the shape of the absorption peaks at 328 and 419 nm can be approximated by their respective neighbouring absorption peaks. Using this approach we obtain estimates for the wavelength of the absorption and its magnitude. Using long-path differential optical absorption spectroscopy (LP-DOAS) observations and multi-axis DOAS (MAX-DOAS) observations, we estimate the peak absorption cross sections of O4 to be (1.96 ± 0.20) × 10−47 cm5 molec−2 and determine the wavelength of its maximum at 328.59 ± 0.15 nm. For the absorption at 419.13 ± 0.42 nm a peak O4 cross-section value is determined to be (5.0 ± 3.5) × 10−48 cm5 molec−2.
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Liu, Ji-Feng. "Theoretical reconsideration on the hydrogen bonding and coordination interactions of chlorophyll a in aqueous solution." Journal of Porphyrins and Phthalocyanines 15, no. 03 (March 2011): 202–10. http://dx.doi.org/10.1142/s1088424611003148.
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In the present work, explicit water molecule and solvent-field effects on the absorption spectrum of chlorophyll a have been studied using time-dependent density functional theory (TDDFT) method. Calculated results show that the one complex and two water coordinated complexes formed by concerted coordination and hydrogen-bonding interactions would be the most preferable conformations of chlorophyll a in aqueous surroundings. Moreover, four obvious absorption bands are assigned by comparing the theoretically simulated absorption spectra with the experimental ones. The theoretical study shows that the explicit water molecule interactions slightly influence the first absorption band. However, the water coordination and hydrogen-bonding interactions can significantly affect the second absorption band which has a strong red-shift. The solvent-field effect due to the polarity of water on absorptions in Q-bands is relatively smaller than that on absorptions in B-bands. As a consequence, our theoretical study on the absorption spectra in the 350–400 nm region presents that the absorption strength in this region was influenced by the explicit coordination and hydrogen bonding interactions from water molecules, significantly.
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Chen, J., and D. S. Venables. "A broadband optical cavity spectrometer for measuring weak near-ultraviolet absorption spectra of gases." Atmospheric Measurement Techniques Discussions 3, no. 5 (October 27, 2010): 4571–602. http://dx.doi.org/10.5194/amtd-3-4571-2010.
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Abstract. Accurate absorption spectra of gases in the near-ultraviolet (300 to 400 nm) are essential in atmospheric observations and laboratory studies. This paper describes a novel incoherent broadband cavity-enhanced absorption spectroscopy (IBBCEAS) instrument for measuring very weak absorption spectra from 335 to 375 nm. The instrument performance was validated against the 3B1−X1A1 transition of SO2. The measured absorption varied linearly with SO2 column density and the resulting spectrum agrees well with published spectra. Using the instrument, we report new absorption cross-sections of O3, acetone, 2-butanone, and 2-pentanone in this spectral region, where literature data diverge considerably. In the absorption minimum between the Huggins and Chappuis bands, our absorption spectra fall at the lower range of reported ozone absorption cross-sections. The spectra of the ketones agree with prior spectra at moderate absorptions, but differ significantly at the limits of other instruments' sensitivity. The collision-induced absorption of the O4 dimer at 360.5 nm was also measured and found to have a maximum cross-section of ca. 4.0 × 10−46 cm5 molecule−2. We demonstrate the application of the instrument to quantifying low concentrations of the short-lived radical, BrO, in the presence of stronger absorptions from Br2 and O3.
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Chen, J., and D. S. Venables. "A broadband optical cavity spectrometer for measuring weak near-ultraviolet absorption spectra of gases." Atmospheric Measurement Techniques 4, no. 3 (March 1, 2011): 425–36. http://dx.doi.org/10.5194/amt-4-425-2011.
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Abstract. Accurate absorption spectra of gases in the near–ultraviolet (300 to 400 nm) are essential in atmospheric observations and laboratory studies. This paper describes a novel incoherent broadband cavity-enhanced absorption spectroscopy (IBBCEAS) instrument for measuring very weak absorption spectra from 335 to 375 nm. The instrument performance was validated against the 3B1-X1A1 transition of SO2. The measured absorption varied linearly with SO2 column density and the resulting spectrum agrees well with published spectra. Using the instrument, we report new absorption cross-sections of O3, acetone, 2-butanone, and 2-pentanone in this spectral region, where literature data diverge considerably. In the absorption minimum between the Huggins and Chappuis bands, our absorption spectra fall at the lower range of reported ozone absorption cross-sections. The spectra of the ketones agree with prior spectra at moderate absorptions, but differ significantly at the limits of other instruments' sensitivity. The collision-induced absorption of the O4 dimer at 360.5 nm was also measured and found to have a maximum cross-section of ca. 4.0×10−46 cm5 molecule−2. We demonstrate the application of the instrument to quantifying low concentrations of the short-lived radical, BrO, in the presence of stronger absorptions from Br2 and O3.
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Okoshi, Katsuya, Yosuke Minowa, Nobunari Kashikawa, Toru Misawa, Daichi Kashino, Hajime Sugai, Kazuya Matsubayashi, Atsushi Shimono, and Shinobu Ozaki. "Multiple Mg ii Absorption Systems in the Lines of Sight to Quadruply Lensed Quasar H1413+1143." Astronomical Journal 162, no. 5 (October 4, 2021): 175. http://dx.doi.org/10.3847/1538-3881/ac0bbb.
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Abstract We find multiple Mg ii absorption systems at redshift z = 1.66, 2.069, and 2.097 in the spatially resolved spectra of the quadruply gravitationally lensed quasar H1413+1143 utilizing the Kyoto tridimensional spectrograph ii (Kyoto 3D ii) spectrograph on board the Subaru telescope. Here we present the first measurement of differences in Mg ii absorption strength of the multiple intervening absorbers, which include ones identified as damped Lyα (DLA) absorption systems. Our detection of the significant Mg ii absorptions in the spatially resolved spectra reveals the inhomogeneous chemical enrichment on scales of about 12 kpc within the separation of the four sight lines. For the DLA system at z = 1.66, the rest equivalent widths (EWs) of the Mg ii absorption lines between the four spatially resolved lines of sight change by factors of up to ∼6, which trace the variations in the H i absorption strength. This suggests that inhomogeneous cold absorbers that give rise to the strong H i/Mg ii absorptions dwell on a scale of about 6–12 kpc between the four lines of sight. We also investigate the degree of variation in the EW of the absorption lines between the lines of sight. We find that the systems giving rise to strong absorptions in the spectra of the quadruply lensed quasars tend to have a high degree of variation in absorption strength between the lines of sight toward the lensed quasars.
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Kremkau, FW. "Molecular Absorption of Ultrasound in Biological Tissues." Physiology 4, no. 1 (February 1, 1989): 26–29. http://dx.doi.org/10.1152/physiologyonline.1989.4.1.26.
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Attenuation of ultrasound in tissues is due primarily to macromolecular absorption. Biomacromolecules have higher absorptions than the constituent molecules of which they are made. Absorption dependencies on structure and solvation are probably interrelated. Underlying absorption processes are enhanced or new processes are added under conditions of high concentration, aggregation, or cross-linking.
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W, Zoelyn, and Mei Ie. "PERAN ORIENTASI PASAR DAN ORIENTASI KEWIRAUSAHAAN DALAM MEMPREDIKSI KINERJA DENGAN DIMEDIASI KAPASITAS ABSORPTIF." Jurnal Muara Ilmu Ekonomi dan Bisnis 7, no. 1 (April 30, 2023): 161–75. http://dx.doi.org/10.24912/jmieb.v7i1.23228.
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Orientasi pasar diartikan sebagai kemampuan individu dalam memahami pelanggan dan menghadapi pesaing. Orientasi kewirausahaan merupakan kemampuan individu dalam berinovasi, bertindak proaktif dan mengambil risiko. Kapasitas absorptif merupakan kemampuan individu dalam mengidentifikasi hal baru dan menerapkan ke dalam usaha. Kinerja UKM merupakan kualitas layanan yang diberikan usaha untuk mencapai keunggulan kompetitif. Penelitian ini diadakan dengan tujuan agar mengetahui kontribusi pada orientasi pasar dan orientasi kewirausahaan terhadap kinerja UKM dan efek mediasi kapasitas absorptif. Penyebaran kuesioner dilakukan oleh peneliti secara online kepada 100 anggota yang berperan menjadi pelaku UKM bidang kuliner di Jakarta Barat. Teknik mengambil sampel menggunakan non-probability sampling yang berpendekatan purposive sampling. PLS-SEM menjadi metode yang dipakai untuk melakukan analisis data yang menggunakan software SmartPLS versi 3.3.9 untuk mengukur tingkat signifikansinya. Penelitian ini menghasilkan orientasi pasar berpengaruh positif namun tidak signifikan terhadap kinerja UKM. Orientasi kewirausahaan memberikan pengaruh yang positif dan signifikan kepada kinerja UKM. Kapasitas absorptif memberikan dampak positif secara signifikan kepada kinerja UKM. Kapasitas absorptif memediasi dengan positif secara signifikan dampak orientasi pasar kepada kinerja UKM. Kapasitas absorptif memediasi dengan positif secara signifikan dampak orientasi kewirausahaan kepada kinerja UKM. Orientasi pasar berpengaruh positif dan signifikan terhadap kapasitas absorptif. Orientasi kewirausahaan berpengaruh positif dan signifikan terhadap kapasitas absorptif. Market orientation is defined as an individual's ability to understand customers and face competitors. Entrepreneurial orientation is an individual's ability to innovate, act proactively and take risks. Absorption capacity is an individual's ability to identify new things and implement them into business. SME performance is the quality of services provided by businesses to achieve competitive advantage. This research was conducted with the aim of knowing the contribution of market orientation and entrepreneurial orientation to the performance of SMEs and the mediating effect of absorptive capacity. Questionnaires were distributed by researchers online to 100 members who played the role of culinary SMEs in West Jakarta. The sampling technique uses non-probability sampling with a purposive sampling approach. PLS-SEM is the method used to perform data analysis using SmartPLS version 3.3.9 software to measure its significance level. This research resulted in market orientation having a positive but not significant effect on the performance of SMEs. Entrepreneurial orientation has a positive and significant influence on the performance of SMEs. Absorption capacity has a significant positive impact on SME performance. Absorption capacity mediates a significantly positive impact of market orientation on SME performance. The absorptive capacity mediates the positive and significant impact of entrepreneurial orientation on SME performance. Market orientation has a positive and significant effect on absorptive capacity. Entrepreneurial orientation has a positive and significant effect on absorptive capacity.
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Burda, C., and Mostafa A. El-Sayed. "High-density femtosecond transient absorption spectroscopy of semiconductor nanoparticles. A tool to investigate surface quality." Pure and Applied Chemistry 72, no. 1-2 (January 1, 2000): 165–77. http://dx.doi.org/10.1351/pac200072010165.
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At the high laser excitation intensities used in our experiments, more than 50 electron-hole pairs are formed in colloidal semiconductor nanoparticles used in our studies. At this density of charge carriers, new transient absorptions are observed in the femtosecond transient spectra in the 450 to 700 nm region with unresolved fast rise (<100 fs) and two decay components of 660 fs and >150 ps. The absorption at 510 nm could be quenched with the adsorption of electron acceptors (e.g., benzoquinone, 1,2-naphthoquinone), whereas the low-energy transient absorption was not affected. For CdS NPs, we found that passivation eliminated most of the transient absorption. The transient absorptions are thus proposed to result from either trap-state absorption, trapped dimers (or complexes) and/or Stark-shifted exciton absorption resulting from surface electric field of the uncompensated trapped electron-hole pairs. All these possibilities require effective surface trapping at these high levels of excitation.
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Lampel, Johannes, Denis Pöhler, Oleg L. Polyansky, Aleksandra A. Kyuberis, Nikolai F. Zobov, Jonathan Tennyson, Lorenzo Lodi, et al. "Detection of water vapour absorption around 363 nm in measured atmospheric absorption spectra and its effect on DOAS evaluations." Atmospheric Chemistry and Physics 17, no. 2 (January 27, 2017): 1271–95. http://dx.doi.org/10.5194/acp-17-1271-2017.
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Abstract. Water vapour is known to absorb radiation from the microwave region to the blue part of the visible spectrum with decreasing efficiency. Ab initio approaches to model individual absorption lines of the gaseous water molecule predict absorption lines up to its dissociation limit at 243 nm.We present the first evidence of water vapour absorption near 363 nm from field measurements using data from multi-axis differential optical absorption spectroscopy (MAX-DOAS) and long-path (LP)-DOAS measurements. The identification of the absorptions was based on the recent POKAZATEL line list by Polyansky et al. (2017). For MAX-DOAS measurements, we observed absorption by water vapour in an absorption band around 363 nm with optical depths of up to 2 × 10−3. The retrieved column densities from 2 months of measurement data and more than 2000 individual observations at different latitudes correlate well with simultaneously measured well-established water vapour absorptions in the blue spectral range from 452 to 499 nm (R2 = 0.89), but the line intensities at around 363 nm are underestimated by a factor of 2.6 ± 0.5 by the ab initio model. At a spectral resolution of 0.5 nm, we derive a maximum cross section value of 2.7 × 10−27 cm2 molec−1 at 362.3 nm. The results were independent of the used literature absorption cross section of the O4 absorption, which overlays this water vapour absorption band. Also water vapour absorption around 376 nm was identified. Below 360 nm no water vapour absorption above 1.4 × 10−26 cm2 molec−1 was observed. The newly found absorption can have a significant impact on the spectral retrievals of absorbing trace-gas species in the spectral range around 363 nm. Its effect on the spectral analysis of O4, HONO and OClO is discussed.
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Nelson, Peter L. "Personality Trait Absorption: An Exploratory Study of Opportunity and Capacity in Relation to Cannabis Use." Imagination, Cognition and Personality 15, no. 1 (September 1995): 75–101. http://dx.doi.org/10.2190/ttd8-89pe-jnvw-ab5n.
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Although the Tellegen Absorption Scale has been widely employed in recent years as a measure of personality Trait Absorption, it is argued that this simple score does not sufficiently discriminate true capacity for Absorption nor does it reveal the level of opportunity made for absorptive experiencing. This study operationalizes Capacity and Opportunity as two additional subscales appended to the Tellegen scale and, by employing the technique of Principal Components Analysis, five useful sub-dimensions are generated. Following on from this Author's earlier suggestion that personality Trait Absorption may be linked to cannabis use and depression, an exploratory study was conducted into the relationship of cannabis use, gender, self-perceived motivation loss and depression to observed levels of overall Absorption as well as to levels of Capacity and Opportunity for absorptive experiencing.
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Lee, Joo-Ha, Do Guen Yoo, and Bo Yeon Lee. "Effective Absorption Capacity Examined by Isothermal Calorimetry: Effect of Pore Structure and Water-to-Cement Ratio." Advances in Materials Science and Engineering 2020 (June 24, 2020): 1–8. http://dx.doi.org/10.1155/2020/7692751.
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The accurate measurement of effective absorption capacity is crucial for highly absorptive materials when they are used within cement-based materials. In this study, a method for examining effective absorption capacity using isothermal calorimetry is reviewed and investigated in detail to accommodate different circumstances. Specifically, the effect of different pore structures and water-to-cement ratios in determining effective absorption capacity is experimentally examined using activated carbon fibre and powdered activated carbon. The results suggest that the method may be suitable for porous materials with micropores but not suitable for those with mesopores. Also, the results indicate that the effective absorption capacity value can change with the water-to-cement ratio used. These findings can be used to find the effective absorption capacity of highly absorptive materials more accurately using the isothermal calorimetry method.
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Wang, Xiao Hua. "Synthesis of Acrylic High-Oil Absorption Resins." Advanced Materials Research 502 (April 2012): 222–26. http://dx.doi.org/10.4028/www.scientific.net/amr.502.222.
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Through suspension polymerization , the influences of different crosslinking agent, initiator, disperser and reaction temperature on oil absorption rate of cetane methacrylate highly oil absorptive resin were studied. The oil absorption ability of the resin for different oil was investigated. The results show the oil absorption capacity of synthesized resins was good with crosslinker divinylbenzene(DVB), initiator benzoyl peroxide(BPO) and disperser polyvinyl alcohol(PVA). Suitable process conditions were: crosslinker DVB 1.0%, initiator BPO 1.2%, disperser PVA 0.8%, reaction temperature 70°C, and oil absorptive power of obtained resin is about 36.6g.g-1 for CC14.
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Yuan, Fang, Qiang Chen, Yuejun Zheng, and Yunqi Fu. "Dual-Mechanism Absorptive Metasurface with Wideband 20 dB RCS Reduction." Crystals 12, no. 4 (April 2, 2022): 493. http://dx.doi.org/10.3390/cryst12040493.
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This paper presents a dual-mechanism method to design a single-layer absorptive metasurface with wideband 20 dB RCS reduction by simultaneously combining the absorption and phase cancellation mechanisms. The metasurface comprises two kinds of absorbing unit cells with 10 dB absorption performance but different reflection phases. The impedance condition for 20 dB RCS reduction is theoretically analyzed considering both the absorption and the phase cancellation based on the two unit cells, and the relationship between the surface impedance and the reflection phase/amplitude is revealed. According to these analyses, two unit cells with absorption performance and different reflection phases are designed and utilized to realize the absorptive metasurface. Numerical and experimental results show that the single-layer absorptive metasurface features wideband 20 dB RCS within 11.5–16 GHz with a thickness of only 3 mm.
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Gotoh, Tamihiro. "Defect absorption in selenium films by photothermal deflection spectroscopy." European Physical Journal Applied Physics 89, no. 1 (January 2020): 10301. http://dx.doi.org/10.1051/epjap/2020190247.
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Sub-gap absorption spectra of selenium films are investigated by photothermal deflection spectroscopy. The selenium films are prepared by vacuum evaporation of selenium pellets. Raman spectroscopy reveals that as-deposited films are amorphous, and the films annealed at 100 °C are trigonal crystal. Photothermal deflection spectroscopy is extended to infrared light of 0.31 eV with maintaining high sensitivity, and detects weak absorption at energies below the band gap. Five absorption peaks and tail absorption are observed in selenium films, and the absorption peak energies are 1.32, 1.08, 0.47, 0.41 and 0.34 eV, respectively. These absorption tail and peaks are derived from selenium, and the origin of these absorptions is explained based on the oxygen impurity and the defect structure of the selenium film.
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Rusli, M., R. S. Nanda, H. Dahlan, M. Bur, and M. Okuma. "Sound Absorption Characteristics of Composite Panel Made from Coconut Coir and Oil Palm Empty Fruit Bunches Fibre with Polyester." International Journal of Automotive and Mechanical Engineering 18, no. 3 (September 21, 2021): 9022–28. http://dx.doi.org/10.15282/ijame.18.3.2021.14.0691.
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The development of pure natural fibres as sound absorptive material remains overlooked due to their lack of mechanical and moist properties, low durability, and vulnerability to be damaged by the environment. Certain fibre treatments are needed to improve such disadvantages. This paper investigates sound absorption characteristics of coconut fibre (coir) and oil palm fibre made from empty fruit bunches (OPEFB) fibre bonded by polyester that can protect them from the ambient environment in order to increase their durability. Two types of fibre-polyester composites have been tested. The first is the fibre-polyester composite (FPC) type, which is totally coated with polyester as the composite matrix. Another type is the fibre-polyester bonded composite (FPBC), in which the polyester is brushed into slice by a slice of the fibre layer in order to coat and bond the fibre, although porous among the fibre remains possible. A two-channel impedance tube is used in the measurement within 200 Hz to 3000 Hz of the frequency range. It is found that FPBC type panel has almost similar sound absorption characteristics to its purely natural fibre as it is able to maintain the panel porosity. The coconut coir fibre panel and its composite have a maximum absorption coefficient of almost 100% within the frequency range 1500-2000 Hz, considerably better than the OPEFB fibre, with only about 80% of the absorption coefficient. If the FPC layer exists, the sound absorption is reduced, and the frequency peaks are also shifted. Additions of the FPC panel layer thickness produced lower sound absorptions and shifted the peaks to the lower frequency range. The FPBC panel type is viable to protect the fibre from the environment without changing its sound absorption characteristics.
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Taheri, Mohammad Ali, Firouz Payervand, Farzad Ahmadkhanlou, Sara Torabi, and Farid Semsarha. "Investigating Ultraviolet-Visible Absorption of Pure Water and Normal Saline under the Treatment of Taheri Consciousness Fields." Scientific Journal of Cosmointel 3, no. 13 (February 9, 2024): 25–30. http://dx.doi.org/10.61450/joci.v3i13.172.
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UV-Vis spectroscopy is a spectrophotometric technique that relies on the absorption of light by species within the ultraviolet to visible range (200 to 700 nanometers). The study of water absorption has been conducted over the decades from the 1930s to the 1980s to investigate electron transfer levels in various studies. The investigation of the absorptive properties of solutions provides significant information about changes in their internal environment, reactions, and molecular interactions. In this study, with the aim of investigating the effectiveness of T-Consciousness Fields on water molecules and examining the potential changes in the physical properties of water, we have focused on the changes in light absorption in the ultraviolet-visible range by water molecules in the presence of T-Consciousness Fields 1, 2, and 3. Additionally, alongside observing the effects of T-Consciousness Fields on the absorptive properties of pure water, the absorptive properties of normal saline are investigated to provide a valuable basis for comparison. In this study, absorptive properties of normal saline are also examined using UV-Vis absorption spectroscopy. Changes in absorption between the control and samples subjected to T-Consciousness Fields 1, 2, and 3 are obtained compared to the standard deviations of changes caused by the control for each wavelength. According to the results obtained for pure water, T-Consciousness Field 1 has led to significant changes in the visible region, exceeding the standard deviation. In the case of normal saline samples, the absorption resulting from the samples in the visible region in the case of T-Consciousness Field 1 shows a decreasing trend, and in the case of T-Consciousness Field 2, it exhibits an increasing trend. Furthermore, the changes in absorption in the sample treated with T-Consciousness Field 3 fall within the range of the average standard deviation of absorption values for the sample and control. A detailed analysis of absorption regions and a comparison of the effectiveness of the three applied T-Consciousness Fields on pure water and normal saline are in the authors' agenda.
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Qi, Honglong, Tian Sang, La Wang, Xin Yin, Jicheng Wang, and Yueke Wang. "Dual-Band Light Absorption Enhancement in Hyperbolic Rectangular Array." Applied Sciences 9, no. 10 (May 16, 2019): 2011. http://dx.doi.org/10.3390/app9102011.
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The effect of dual-band light absorption enhancement in a hyperbolic rectangular array (HRA) is presented. The enhanced light absorption of the HRA results from the propagating surface plasmon (PSP) resonance, and a dual-band absorption with low and flat sideband level can be realized. The impedance theory is used to evaluate the absorption properties of the HRA, and shows that the input impedances of the HRA varied abruptly around the absorption bands to meet the impedance matching. The absorption spectra of the HRA can be estimated using the effective medium theory (EMT), and its accuracy can be improved as the number of film stacks is increased. The dual-band absorptions of the HRA are very robust to the variations of the width and the number of film stack. Potential application in refractive index sensing can be achieved by utilizing the two absorption bands.
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Ba, YinYing, MengLin Wang, KunFeng Zhang, QiJun Chen, JiaJia Wang, Hang Lv, YanYan Jiang, and Renbing Shi. "Intestinal Absorption Profile of Three Polygala Oligosaccharide Esters in Polygalae Radix and the Effects of Other Components in Polygalae Radix on Their Absorption." Evidence-Based Complementary and Alternative Medicine 2019 (July 2, 2019): 1–12. http://dx.doi.org/10.1155/2019/1379531.
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Oligosaccharide esters, which are among the main active components of Polygalae Radix (PR), demonstrate significant pharmacological activities in the human nervous system. In our previous research, some other constituents in PR were able to improve the bioavailability of oligosaccharide esters such as sibiricose A5 (SA5), sibiricose A6 (SA6), and 3,6′-disinapoyl sucrose (DISS), but the related components and their underlying mechanisms remain unknown. The present study aimed to investigate the intestinal absorptive profile of SA5, SA6, and DISS and the absorptive behavior influenced by the coadministration of polygalaxanthone III and total saponins of PR (TS) using an in vitro everted rat gut sac model, along with the possible mechanisms that may influence absorption. The results showed that TS could significantly enhance the absorption of SA5, SA6, and DISS monomers. Verapamil, a P-glycoprotein inhibitor, was able to elevate the absorption of SA5 and SA6, and an absorption experiment using Rho123 led us to conclude that TS influenced the absorption of SA5 and SA6 in a manner similar to that of a P-glycoprotein inhibitor. Sodium caprate, a paracellular absorption enhancer, was found to increase the absorption of SA5, SA6, and DISS. Results showed that the absorption mechanisms of SA5 and SA6 may combine active transport with paracellular passive penetration, while DISS’s absorption was dominated by paracellular passive penetration. However, the relationship between polygala saponins and the absorption of SA5, SA6, and DISS by paracellular passive penetration remain to be examined. This is the direction of our future research.
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Herreman, Kevin. "Which absorption coefficients are correct?" Journal of the Acoustical Society of America 155, no. 3_Supplement (March 1, 2024): A91. http://dx.doi.org/10.1121/10.0026917.
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Each year absorptive material samples are sent to various accredited acoustic laboratories around the country by manufacturers who want to verify the performance of their products. Results are published as indisputable validation of the product absorption performance by the manufacturer. As no recent interlaboratory study results for ASTM C423—Standard Test Method for Sound Absorption and Sound Absorption Coefficients by the Reverberation Room Method are available, the Owens Corning Acoustic Research Center initiated a private interlaboratory study. A small set of accredited acoustical laboratories tested a set of the original National Voluntary Laboratory Accreditation Program reference panels. The resulting data and differences in the measured absorption coefficients will be reviewed.
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Okoshi, Katsuya, Yosuke Minowa, Nobunari Kashikawa, Suzuka Koyamada, and Toru Misawa. "Multiple Absorption Systems in the Lines of Sight to Quadruply Lensed Quasar H1413+1143 As a Probe of the Circumgalactic medium around Dwarf Galaxy." Proceedings of the International Astronomical Union 14, S344 (August 2018): 305–8. http://dx.doi.org/10.1017/s1743921318006683.
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AbstractWe present the first measurement of differences in MgII absorption strength in multiple intervening absorbers, which are also identified as (sub-)Damped Lyman alpha absorption systems, in the four spectra of the quadruply lensed quasar H1413+1143, often referred to the “Cloverleaf”, from highly spatial resolution and high signal-to-noise spectroscopy with an optical multi-mode spectrograph, the Kyoto tridimentional spectrograph II on board the Subaru telescope. The detection of significant MgII absorptions in multiple components in the spatially-resolved spectra suggests that chemical enrichment differs at least on scale of about 10 kpc within the separation of sightlines. For, a DLA system at redshift zabs = 1.66, the rest equivalent widths of MgII absorption lines change by factors up to 6, which is similar to those of HI absorption lines. This suggests that (inhomogeneous) cold absorbers which give rise to strong HI/MgII absorptions dwell on a scale within 10 kpc in the circumgalactic medium (CGM).
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Hargrove, J. "Water dimer absorption of visible light." Atmospheric Chemistry and Physics Discussions 7, no. 4 (July 27, 2007): 11123–40. http://dx.doi.org/10.5194/acpd-7-11123-2007.
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Abstract. Laboratory measurements of water vapor absorption using cavity ring-down spectroscopy revealed a broad absorption at 405 nm with a quadratic dependence on water monomer concentration, a similar absorption with a linear component at 532 nm, and only linear absorption at 570 nm in the vicinity of water monomer peaks. D2O absorption is weaker and linear at 405 nm. Van't Hoff plots constructed at 405.26 nm suggest that for dimerization, Keq=0.056±0.02 atm−1, ΔH°301 K=−16.6±2 kJ mol−1 and ΔS°301 K=−80±10 J mol−1 K−1. This transition peaks at 409.5 nm, could be attributed to the 8th overtone of water dimer and the 532 nm absorption to the 6th overtone. It is possible that some lower overtones previously searched for are less enhanced. These absorptions could increase water vapor feed back calculations leading to higher global temperature projections with currently projected greenhouse gas levels or greater cooling from greenhouse gas reductions.
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Bastl, C. P., G. Schulman, and E. J. Cragoe. "Low-dose glucocorticoids stimulate electroneutral NaCl absorption in rat colon." American Journal of Physiology-Renal Physiology 257, no. 6 (December 1, 1989): F1027—F1038. http://dx.doi.org/10.1152/ajprenal.1989.257.6.f1027.
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Glucocorticoids, not aldosterone, may regulate basal colonic NaCl transport. Aldosterone induces spironolactone-inhibitable, amiloride-inhibitable conductive Na absorption but basal transport is electroneutral and amiloride and spironolactone resistant. We examined in vivo the Na absorptive pathway induced by glucocorticoid receptor specific doses of glucocorticoid using various amiloride analogues. Doses of dexamethasone sufficient to co-occupy aldosterone receptors produced amiloride-sensitive Na absorption in proximal and distal colon. Low doses of dexamethasone or the specific glucocorticoid RU26988 markedly stimulated Na absorption but did so by an amiloride-resistant mechanism. The Na-H antiport inhibitor, 5-N-ethyl-N-isopropylamiloride (NENIA) eliminated glucocorticoid-induced Na and Cl absorption without changing transmural potential difference (PD) in proximal and distal colon (Ki = 0.7 x 10(-7) M). NENIA had no effect on aldosterone-induced transport. NENIA (10(-5) M) almost eliminated Na absorption in adrenal intact animals if infused early in the experimental protocol. With time, NENIA resistance developed, corresponding with the previously documented rise in endogenous aldosterone. Thus glucocorticoids induce an electroneutral Na absorptive pathway that may be the luminal Na-H antiport, suggesting that glucocorticoids regulate adrenal-dependent electroneutral Na absorption in rat colon.
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Jin, Li, Jun Zhou, and Puxiang Lai. "Tunable absorption characteristics in multilayered structures with graphene for biosensing." Journal of Innovative Optical Health Sciences 13, no. 04 (June 10, 2020): 2050017. http://dx.doi.org/10.1142/s1793545820500170.
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Graphene derivatives, possessing strong Raman scattering and near-infrared absorption intrinsically, have boosted many exciting biosensing applications. The tunability of the absorption characteristics, however, remains largely unexplored to date. Here, we proposed a multilayer configuration constructed by a graphene monolayer sandwiched between a buffer layer and one-dimensional photonic crystal (1DPC) to achieve tunable graphene absorption under total internal reflection (TIR). It is interesting that the unique optical properties of the buffer-graphene-1DPC multilayer structure, the electromagnetically induced transparency (EIT)-like and Fano-like absorptions, can be achieved with pre-determined resonance wavelengths, and furtherly be tuned by adjusting either the structure parameters or the incident angle of light. Theoretical analyses demonstrate that such EIT- and Fano-like absorptions are due to the interference of light in the multilayer structure and the complete transmission produced by the evanescent wave resonance in the configuration. The enhanced absorptions and the huge electrical field enhancement effect exhibit potentials for broad applications, such as photoacoustic imaging and Raman imaging.
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DUCHEK, STEPHANIE. "DESIGNING ABSORPTIVE CAPACITY? AN ANALYSIS OF KNOWLEDGE ABSORPTION PRACTICES IN GERMAN HIGH-TECH FIRMS." International Journal of Innovation Management 19, no. 04 (August 2015): 1550044. http://dx.doi.org/10.1142/s1363919615500449.
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The concept of absorptive capacity was introduced by Cohen and Levinthal in 1989 as an important condition for high innovativeness. Since then it has been enhanced through reconceptualisations and extended by various empirical studies. Despite the growing interest in the concept, the processes and practices of absorptive capacity have largely remained a "black box". To fill this gap, the paper develops a practice-based approach of absorptive capacity and provides an in-depth empirical investigation to shed more light on the practice of knowledge absorption. Drawing on the case studies of two German high-tech firms, the paper focusses on practices designed by the management to facilitate knowledge absorption and shows how these practices were actually enacted. The paper contributes to a better understanding of the complex construction of absorptive capacity and gives useful insights for a successful management of knowledge absorption.
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Van Clief-Stefanon, Lyrae. "Absorption." Callaloo 34, no. 3 (2011): 866. http://dx.doi.org/10.1353/cal.2011.0188.
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Menzies, Victoria, Ann Gill Taylor, and Cheryl Bourguignon. "Absorption." Journal of Holistic Nursing 26, no. 4 (December 2008): 297–302. http://dx.doi.org/10.1177/0898010107307456.
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Xu, Wanting, Na Liu, and Zhongchen Lu. "Recent Progress of Iron-Based Magnetic Absorbers and Its Applications in Elastomers: A Review." Materials 17, no. 16 (August 15, 2024): 4058. http://dx.doi.org/10.3390/ma17164058.
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As a result of continuing scientific and technological progress, electromagnetic waves have become increasingly pervasive across a variety of domains, particularly within the microwave frequency range. These waves have found extensive applications in wireless communications, high-frequency electronic circuits, and several related fields. As a result, absorptive materials have become indispensable for dual-use applications across both the military and civilian domains because of their exceptional electromagnetic wave absorption properties. This paper, beginning with the operating mechanisms of absorptive materials, aims to provide an overview of the strategies that have been used to enhance the absorption performance of iron-based magnetic absorbers (IBMAs) and discuss the current research status of absorptive material components. The fabrication of a ferromagnetic absorber in terms of morphology, heterointerface coupling, and macrostructural enhancements and the effect of powder characteristics on their electromagnetic properties are discussed. Additionally, the application of IBMAs in elastomers is summarized. Finally, this paper summarizes the limitations of existing ferromagnetic absorber materials and offers a perspective on their potential future developments. The objective of the ongoing research is to fabricate absorptive components that have thin profiles, lightweight construction, wide absorption frequency ranges, and strong absorption capabilities.
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Kemp, Adrienne W. "Absorption sampling and the absorption distribution." Journal of Applied Probability 35, no. 2 (June 1998): 489–94. http://dx.doi.org/10.1239/jap/1032192864.
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The inverse absorption distribution is shown to be a q-Pascal analogue of the Kemp and Kemp (1991) q-binomial distribution. The probabilities for the direct absorption distribution are obtained via the inverse absorption probabilities and exact expressions for its first two factorial moments are derived using q-series transformations of its probability generating function. Alternative models for the distribution are given.
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Kemp, Adrienne W. "Absorption sampling and the absorption distribution." Journal of Applied Probability 35, no. 02 (June 1998): 489–94. http://dx.doi.org/10.1017/s0021900200015114.
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The inverse absorption distribution is shown to be a q-Pascal analogue of the Kemp and Kemp (1991) q-binomial distribution. The probabilities for the direct absorption distribution are obtained via the inverse absorption probabilities and exact expressions for its first two factorial moments are derived using q-series transformations of its probability generating function. Alternative models for the distribution are given.
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Erika Mulyana Gultom and M. Turmuzi Lubis. "APLIKASI KARBON AKTIF DARI CANGKANG KELAPA SAWIT DENGAN AKTIVATOR H3PO4 UNTUK PENYERAPAN LOGAM BERAT Cd DAN Pb." Jurnal Teknik Kimia USU 3, no. 1 (March 31, 2014): 5–10. http://dx.doi.org/10.32734/jtk.v3i1.1493.
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This research aims to determine the optimum conditions ofactivated carbon made of palm shells activated with H3PO4as an absorber of heavy metals such as Cd and Pb. The research methodology includes the preparation of activated carbon, absorption, and testing. Absorption stage is done by varying the concentration of heavy metals are 5 ppm, 10 ppm, 15 ppm, 20 ppm and activated carbon mass per run, which is0.5 grams. Another variable are the contact time with intervals of 5 minutes and the pH arranged heavy metals 2-9. Testing activated carbon absorption to heavy metals using atomic adsorption spectrofotometric (AAS). The results showed that the most optimum absorption is concentration of 10 ppm, 40 minutes and pH absorption3-4. Absorption of heavy metals Cd and Pb obtained 84,61 % and 80,13 %.
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Panchenko, T. V. "Optical absorption of Bi12SiO20:Sn crystals." Functional materials 22, no. 2 (June 30, 2015): 169–74. http://dx.doi.org/10.15407/fm22.02.169.
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Saleh, R., C. J. Hennigan, G. R. McMeeking, W. K. Chuang, E. S. Robinson, H. Coe, N. M. Donahue, and A. L. Robinson. "Absorptivity of brown carbon in fresh and photo-chemically aged biomass-burning emissions." Atmospheric Chemistry and Physics Discussions 13, no. 5 (May 2, 2013): 11509–36. http://dx.doi.org/10.5194/acpd-13-11509-2013.
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Abstract. Experiments were conducted to investigate light absorption of organic aerosol (OA) in fresh and photo-chemically aged biomass-burning emissions. The experiments considered residential hardwood fuel (oak) and fuels commonly consumed in wild-land and prescribed fires in the United States (pocosin pine and gallberry). Photo-chemical aging was performed in an environmental chamber. We constrained the light-absorption properties of the OA using conservative limiting assumptions, and found that both primary organic aerosol (POA) in the fresh emissions and secondary organic aerosol (SOA) produced by photo-chemical aging absorb light to a significant extent, and are categorized as brown carbon. This work presents the first direct evidence that SOA produced in aged biomass-burning emissions is absorptive. For the investigated fuels, SOA is less absorptive than POA in the long visible, but exhibits steeper wavelength-dependence (larger Absorption Ångström Exponent) and is more absorptive in the short visible and near-UV. Light absorption by SOA in biomass-burning emissions might be an important contributor to the global radiative forcing budget.
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Oramasionwu, Gloria E., Tom D. Thacher, Sunday D. Pam, John M. Pettifor, and Steven A. Abrams. "Adaptation of calcium absorption during treatment of nutritional rickets in Nigerian children." British Journal of Nutrition 100, no. 2 (August 2008): 387–92. http://dx.doi.org/10.1017/s0007114507901233.
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Nutritional rickets in Nigerian children has been effectively treated with Ca supplementation. High values of Ca absorption efficiency have been observed in untreated children, but whether Ca absorption efficiency changes during treatment with Ca is unknown. Our objective in conducting this study was to identify the effect of Ca therapy on Ca absorptive efficiency in children with primary Ca-deficient nutritional rickets. Twelve children with radiographically active rickets, 2 to 14 years of age (median 39 months) participated in the study. We assessed dietary Ca intake via dietary recalls, and measured biochemical markers of Ca and vitamin D homeostasis. Fractional Ca absorption was measured using a dual tracer stable isotope method, before and after 2 weeks of treatment with 15·0 mmol elemental Ca daily. Ten children had adequate urine collection for inclusion in the analysis. Usual dietary Ca intake was 4·2 (sd 1·0) mmol/d. The median Ca absorption prior to treatment was 72 % (range 52–97 %) and decreased significantly to 57 % (31–84 %) (P = 0·004) after 2 weeks of supplementation. We conclude that Nigerian children with rickets adapt to Ca supplementation with a small decrease in Ca absorptive capacity, but retain very high absorptive levels during supplementation. Overall Ca absorption efficiency was comparable with that identified in other populations with low Ca intakes. These data demonstrate that although absorptive capacity is regulated by supplementation, recovery from rickets likely occurs through efficient use of both dietary and supplemental Ca.
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Maeshima, Hiroshi, Kosei Matsumoto, Yasuhiro Hirahara, Takao Nakagawa, Ryoichi Koga, Yusuke Hanamura, Takehiko Wada, et al. "Infrared Absorption and Its Sources of CdZnTe at Cryogenic Temperature." Journal of Electronic Materials 51, no. 2 (January 3, 2022): 564–76. http://dx.doi.org/10.1007/s11664-021-09361-1.
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AbstractTo reveal the causes of infrared absorption in the wavelength region between electronic and lattice absorptions, we measured the temperature dependence of the absorption coefficient of p-type low-resistivity ($$\sim 10^2~ \Omega \mathrm{cm}$$ ∼ 10 2 Ω cm ) CdZnTe crystals. We measured the absorption coefficients of CdZnTe crystals in four wavelength bands ($$\lambda =6.45$$ λ = 6.45 , 10.6, 11.6, 15.1$$~\mu $$ μ m) over the temperature range of $$T=8.6$$ T = 8.6 -300 K with an originally developed system. The CdZnTe absorption coefficient was measured to be $$\alpha =0.3$$ α = 0.3 -0.5 $$\mathrm{cm}^{-1}$$ cm - 1 at $$T=300$$ T = 300 K and $$\alpha =0.4$$ α = 0.4 -0.9 $$\mathrm{cm}^{-1}$$ cm - 1 at $$T=8.6$$ T = 8.6 K in the investigated wavelength range. With an absorption model based on transitions of free holes and holes trapped at an acceptor level, we conclude that the absorption due to free holes at $$T=150$$ T = 150 -300 K and that due to trapped-holes at $$T<50$$ T < 50 K are dominant absorption causes in CdZnTe. We also discuss a method to predict the CdZnTe absorption coefficient at cryogenic temperature based on the room-temperature resistivity.
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King, Janet C. "Does Zinc Absorption Reflect Zinc Status?" International Journal for Vitamin and Nutrition Research 80, no. 45 (October 1, 2010): 300–306. http://dx.doi.org/10.1024/0300-9831/a000037.
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Unlike iron, zinc absorption is influenced by dietary zinc intake, not zinc status. As dietary zinc increases, the total amount of absorbed zinc increases while the percent absorbed declines. The gastrointestinal tract maintains whole-body zinc homeostasis by adjusting endogenous zinc losses to the amount absorbed. At intakes below about 9 mg/day, zinc absorption occurs primarily by a saturable (carrier) process involving ZIP4, ZnT1, and other transporters. There is no evidence that past zinc intakes, or status, influences zinc absorption. Instead, current zinc intake is the chief determinant of zinc absorption. Supplemental zinc taken with water in the post-absorptive state initially is absorbed more efficiently than food zinc, but absorption efficiency declines within 24 hours presumably due to down-regulation of the zinc transporters. More research is needed to understand the effect of physiological state on zinc absorption.
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MAENG, INHEE, SEUNG HYUN BAEK, HWA YEON KIM, GYEONG-SIK OK, SUNG-WOOK CHOI, and HYANG SOOK CHUN. "Feasibility of Using Terahertz Spectroscopy To Detect Seven Different Pesticides in Wheat Flour." Journal of Food Protection 77, no. 12 (December 1, 2014): 2081–87. http://dx.doi.org/10.4315/0362-028x.jfp-14-138.
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This study investigated the feasibility of detecting pesticides using terahertz (THz) spectroscopy in high-density polyethylene and/or wheat flour mixtures. The absorption spectra of seven pesticides (dicofol, chlorpyrifos, chlorpyrifos-methyl, daminozide, imidacloprid, diethyldithiocarbamate, and dimethyldithiocarbamate) were measured in the frequency range 0.1 to 3 THz at room temperature. Five of the seven pesticides exhibited specific absorption peaks in the low-energy THz range. The two remaining pesticides had no specific absorption peaks in this frequency range, but they exhibited different frequency-dependent refractive indices. The absorption coefficients of imidacloprid increased with its increasing weight ratio in high-density polyethylene, and the fitted power absorptions and refractive indices using a Maxwell-Garnett effective medium model were comparable to the measured data. Imidacloprid was also identified from its characteristic absorption peaks in wheat flour mixtures, and a linear relationship between the absorption coefficient and the weight ratio was observed. Our results show the potential of detection of selected pesticides in foods, such as wheat flour, using THz spectroscopy.
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Sharon, Maheshwar, Ritesh Vishwakarma, Abhijeet Rajendra Phatak, Golap Kalita, Nallin Sharma, and Madhuri Sharon. "Microwave wide band absorption by carbon from Corn cob-1." JOURNAL OF ADVANCES IN PHYSICS 12, no. 2 (August 30, 2016): 4204–12. http://dx.doi.org/10.24297/jap.v12i2.53.
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Corn cob, an agricultural waste, is paralyzed at different temperatures (700oC, 800oC and 900oC). Microwave absorption of carbon in the frequency range of 2 GHz to 8 GHz is reported. Carbon activated  with 5% nickel nitrate showed more than 90% absorption of microwave in the frequency range from 6 GHz to 8 GHz, while carbon activated  with 10% Nickel nitrate treated corn cob showed 90% absorption in the frequency range of 2.5 GHz to 5 GHz. Carbon showing the best absorption are characterized by XRD, Raman spectra and SEM . It is suggested that corn cob treatment  alone with KOH did not improve the microwave absorption, whereas treatment along with nickel nitrate improved the absorption property much better. It is proposed that treatment with nickel nitrate helps in creating suitable pores in carbon  which improved the absorption behavior because while treating carbon with 1N HCl helps to leach out nickel creating equivalent amount of pores in the carbon.
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Yeo, C. J., J. A. Bastidas, R. E. Schmieg, and M. J. Zinner. "Meal-stimulated absorption of water and electrolytes in canine jejunum." American Journal of Physiology-Gastrointestinal and Liver Physiology 259, no. 3 (September 1, 1990): G402—G409. http://dx.doi.org/10.1152/ajpgi.1990.259.3.g402.
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After a meal, the absorption of water and electrolytes from the jejunal lumen increases. This meal-induced jejunal absorption occurs in jejunal segments out of normal gastrointestinal continuity. The experimental model used 25-cm proximal jejunal Thiry-Vella loops in awake dogs (n = 72 observations) to evaluate the mechanisms involved in meal-induced jejunal absorption, seeking to define the source or sources of the proabsorptive signal. Specifically, we evaluated the jejunal absorptive response to a standard meal, a standard meal plus cholinergic blockage using atropine, a sham-fed meal, a gavage-fed meal, and gastric distension with balloon and gavage water. Both the standard meal and the gavage-fed meal induced a prompt, sustained, and significant (P less than 0.0001) increase in the absorption of H2O, Na+, and Cl-. Atropine significantly reduced the magnitude of the postmeal absorptive response (P less than 0.05) compared with the standard meal alone. The sham-fed meal, gastric balloon distension, and gavage water did not alter jejunal absorption. Vagal nerve integrity after cervical esophageal manipulation was verified by gastric acid output and gastrin response to stimuli. These data support a role for cholinergic modulation of meal-stimulated jejunal absorption via a cephalic-phase-independent and gastric-distension-independent mechanism.
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Gallardo, Pedro, Nancy Olea, and Francisco V. Sepúlveda. "Distribution of aquaporins in the colon of Octodon degus, a South American desert rodent." American Journal of Physiology-Regulatory, Integrative and Comparative Physiology 283, no. 3 (September 1, 2002): R779—R788. http://dx.doi.org/10.1152/ajpregu.00218.2002.
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Octodon degus is a desert rodent of northern Chile, adapted to survive with a limited supply of water. This rodent has a high degree of fecal dehydration, related to colon water absorption. With the hypothesis that aquaporins (AQPs) might be present in the colon epithelium of O. degus and involved in fluid absorption, we studied colon water absorption in vivo and the distribution of AQPs and Na+ transporters by immunocytochemistry. AQP-1 was found in apical and basolateral membranes of surface-absorptive and crypt epithelial cells. AQP-8 was found in the cytoplasm of enterocytes of surface colon. AQP-3 immunolabeling, on the other hand, was absent from the epithelium but present in a subepithelial fibroblast layer, pericryptal cells, and muscularis mucosae. The hydration state did not modify the amount of immunostaining for any of the AQPs. Colon water absorption was markedly decreased by the mercurial agent p-chloromercuribenzenesulfonic acid and was not affected by water deprivation. The NHE3 isoform of Na+/H+exchanger and α-1 subunit of the Na+-K+-ATPase were found in apical and basolateral membranes of surface-absorptive cells, respectively. These results suggest that colon water absorption is mostly transcellular and mediated by water channels like AQP-1. Apical Na+/H+ exchanger and basolateral Na+-K+-ATPase in surface cells could be part of the Na+ absorption pathway. It is hypothesized that this transport is necessary to provide an osmotic gradient for water absorption. The roles of AQP-8 and AQP-3 in water absorption remain to be established.
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Ohkohchi, Nobuhiro, Tadashi Andoh, Ryoji Ohi, and Shozo Mori. "Defined Formula Diets Alter Characteristics of the Intestinal Transport of Amino Acid and Peptide in Growing Rats." Journal of Pediatric Gastroenterology and Nutrition 10, no. 4 (May 1990): 490–96. http://dx.doi.org/10.1002/j.1536-4801.1990.tb10035.x.
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SummaryRecently defined formula diets are widely used for patients with digestive diseases. Long‐term administration of such diets is presumed to change the absorptive characteristics of the small intestine. We investigated the influence of the defined formula diet on the absorptive capacity of growing rats by measuring the potential difference of sugars, amino acid, half‐maximum concentration (kt) of these substrates, the activities of disaccharidase and dipeptidase, and the portal amino acid concentrations. There was no significant difference in the body weight of rats fed amino acid or peptide diets and those given the normal chow, but the administration of the defined formula diets reduced the absorption of amino acid and small peptide per serosal area and kt. On the other hand, absorption of sugars was not significantly influenced by the type of the diets. The differences in the absorptions of amino acid and peptide following the administration of the defined formula diet might be associated with the change in the resistance of the unstirred water layer or the alteration in the active transport system of amino acids or peptides in the small intestine. No significant differences were observed between the influences of the amino acid and the peptide diets.
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Wei, X. F., J. F. Ruan, C. G. Xie, H. Yuan, and J. Song. "Two-Colour Mid-Infrared Optical Absorption under Electric Field in an InAs/GaSb-Based Type II and Broken-Gap Quantum Well." Applied Mechanics and Materials 130-134 (October 2011): 4122–25. http://dx.doi.org/10.4028/www.scientific.net/amm.130-134.4122.
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The optical absorptions are calculated in an InAs/GaSb-based type II and broken-gap quantum well under applied electric field. Two absorption peaks were observed through intraband transitions within the same material layer. The absorption induced by the interlayer transition is rather weak due to the small overlap of electron and hole wavefunctions. The optical absorption can be significantly affected by the applied electric field. Our results suggest that InAs/GaSb-based type II and broken-gap QWs can be employed as two-colour photodetectors, which can be controlled by the applied electric field.
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Krełowski, Jacek. "Diffuse Interstellar Bands – The Unidentified Part of the Interstellar Absorption Spectrum." Symposium - International Astronomical Union 135 (1989): 67–86. http://dx.doi.org/10.1017/s0074180900125112.
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The unidentified (since 1921) diffuse interstellar bands (DIBs) are discussed together with their relations to other interstellar absorptions sucn as: continuous extinction, polarization and atomic or molecular absorption lines. It is shown that DIBs do not form the absorption spectrum of one agent, but probably of several (3 or more). DIBs as well as other interstellar absorptions are usually formed in several clouds along a line-of-sight. Thus, they suffer Doppler splitting; the first high resolution profiles free of the latter effect are described. Since single interstellar clouds may differ not only in radial velocities but also in many physical (optical) parameters, the observed interstellar absorptions are ill-defined averages over all clouds situated along any line-of-sight. It is of basic importance to determine not only the single cloud profiles of diffuse bands, but also their relations to other interstellar absorptions in the same clouds. Intensity ratios of DIBs are shown to be sensitive to the shapes of extinction curves, depletion patterns of elements and molecular abundances in the considered clouds. The sensitivity of the DIBs to the variation in polarization is less documented but probably also present. Thus the diffuse lines are presented as the unidentified part of the absorption spectrum of interstellar matter. Their identification depends on the determination of their relations to other interstellar absorptions which must be determined precisely.
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Wariyah, Chatarina, Mary Astuti, Supriyadi Supriyadi, and Chairil Anwar. "CALCIUM ABSORPTION KINETIC ON INDONESIAN RICE." Indonesian Journal of Chemistry 8, no. 2 (June 17, 2010): 252–57. http://dx.doi.org/10.22146/ijc.21630.
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Calcium absorption kinetic from three varieties rice i.e. low-, medium-, and high amylose content were evaluated. Three calcium salt (calcium acetate, -lactate and - gluconate) were used as a fortifican. Each rice was soaked at the calcium salts at soaking temperatures of 80, 90 and 100 oC, for 30 min and the calcium content was analyzed periodically. Reaction rate constant was determined from slope of curve of the relation of soaking time and absorbed calcium. The activation energy was determined by Arrhenius equation. The research showed that rice calcium absorption follows the first-order kinetic and absorption rate tends to decrease with increasing temperature. Calcium absorptions were affected by calcium salt solubility. Calcium acetate was absorbed easier than calcium lactate and calcium lactate was absorbed easier than calcium gluconate, but the absorption rate constant of calcium acetate was lower than that of calcium lactate, and calcium lactate was lower than calcium gluconate. Based on amylose content of rice, the higher the amylose content, the lower calcium absorption rate. The activation anergy of the high amylose rice was higher than that of low amylose content. Keywords: amylose content, calcium absorption, reaction kinetic, calcium salt
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Lee, Yiu-Yin. "Chaotic Vibration and Perforation Effects on the Sound Absorption of a Nonlinear Curved Panel Absorber." Mathematics 11, no. 14 (July 20, 2023): 3178. http://dx.doi.org/10.3390/math11143178.
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This study is the first to investigate the effect of chaotic vibration on the sound absorption of a curved perforated panel. Previous studies on the effect of nonlinear vibration on the sound absorption of a panel absorber have focused on periodic responses only. In this study, a sound absorption formula was derived by considering the panel impedance and perforation impedance. The numerical integration method was adopted to generate various chaotic vibrational responses, which were used to compute the corresponding sound absorptions. Several interesting findings that have never been observed in any previous studies on acoustic absorption were derived. First, in the chaotic and highly nonlinear cases, as the excitation frequency increased, the corresponding response frequencies decreased. This was opposite to the typical trend in linear cases, in which higher excitation frequencies corresponded to higher response frequencies. Second, in chaotic cases, absorption mainly occurred due to panel vibration effects. This is also in stark contrast to the findings of studies on perforated vibrating panels, in which the absorption effect mainly originates from perforations. Additionally, the absorption bandwidths are much wider and can shift to higher frequencies; however, the peak absorption coefficients were approximately 20% lower than in the case of the perforation effect only. Third, in the quasi-chaotic case, the absorption curve in the case of the perforation effect plus the vibration effect was between the absorption curves of the perforation effect only and the perforation effect plus the vibration effect.
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Lane, John S., Edward E. Whang, David A. Rigberg, Oscar J. Hines, David Kwan, Michael J. Zinner, David W. McFadden, Jared Diamond, and Stanley W. Ashley. "Paracellular glucose transport plays a minor role in the unanesthetized dog." American Journal of Physiology-Gastrointestinal and Liver Physiology 276, no. 3 (March 1, 1999): G789—G794. http://dx.doi.org/10.1152/ajpgi.1999.276.3.g789.
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Traditionally, intestinal glucose absorption was thought to occur through active, carrier-mediated transport. However, proponents of paracellular transport have argued that previous experiments neglected effects of solvent drag coming from high local concentrations of glucose at the brush-border membrane. The purpose of this study was to evaluate glucose absorption in the awake dog under conditions that would maximize any contribution of paracellular transport. Jejunal Thiry-Vella loops were constructed in six female mongrel dogs. After surgical recovery, isotonic buffers containingl-glucose as the probe for paracellular permeability were given over 2-h periods by constant infusion pump. At physiological concentrations ofd-glucose (1–50 mM), the fractional absorption ofl-glucose was only 4–7% of total glucose absorption. Infusion of supraphysiological concentrations (150 mM) of d-glucose,d-maltose, ord-mannitol yielded low-fractional absorptions ofl-glucose (2–5%), so too did complex or nonabsorbable carbohydrates. In all experiments, there was significant fractional water absorption (5–19%), a prerequisite for solvent drag. Therefore, with even up to high concentrations of luminal carbohydrates in the presence of significant water absorption, the relative contribution of paracellular glucose absorption remained low.
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Nguyen, Huong, and Erling Nilsson. "The effect of furniture on room acoustic parameters and its dependence on different suspended ceilings' sound absorptive properties." INTER-NOISE and NOISE-CON Congress and Conference Proceedings 268, no. 3 (November 30, 2023): 5709–18. http://dx.doi.org/10.3397/in_2023_0814.
Full textAbstract:
In ordinary public rooms such as classrooms and offices, the base line of acoustical treatment is an absorbent suspended ceiling. Due to the non-uniform distribution of the absorptive material, the scattering as well as the absorption properties of furniture will have a significant influence on room acoustic parameters such as reverberation time, speech clarity and sound strength. In particular, the absorption of the sound scattered energy will depend on the absorbing efficiency of the suspended ceiling. This effect is not accounted for in classical diffuse field models such as Sabine's formula. Measurements were conducted in the reverberant room with varying degrees of furnishing for several ceiling treatments ranging from highly reflective to highly absorptive. Using Sabine's formula and the Statistical Energy Analysis model, this paper discusses the scattering effect of furniture on room acoustic parameters such as reverberation time, speech clarity and sound strength as well as how the equivalent scattering absorption area is related to the absorbing efficiency of the suspended ceiling. It is concluded that a novel method for the quantification of furniture is needed to include both absorption and scattering effects of furniture on reverberation time and its dependence on the suspended ceilings' absorptive properties.