Increased Absorption Efficiency Research Articles

Indoor air quality improvement using developed polymeric membrane filter

Abstract Carbon dioxide (CO2) levels must be controlled to protect the environment and human health. Previous studies focused on improving indoor air quality (IAQ) by reducing these negative impacts with electrical equipment such as mechanical ventilators and air purifiers; however, passive techniques were lacking. This work develops a prototype membrane filters to improve IAQ by capturing and separating indoor CO2 levels. These filters use polyvinyl alcohol (PVA) membranes and activated carbon (AC) as innovative and effective passive materials at four concentrations. Scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR), and X-Ray diffraction (XRD) were employed to characterize the materials. The effectiveness of CO2 absorption across the four filter types was then assessed through tests conducted in a controlled environment. Subsequently, site monitoring was undertaken to evaluate the most effective filter. The absorption rates of CO2 levels indoors of the developed filters are 17.5%, 8.1%, 4.5%, and 3.4%, respectively, for four filters. The most efficient filter increased absorption efficiency by 47.8% in an unoccupied space and 35.5% in an occupied one. This passive material can be applied in various indoor spaces, including office buildings, residential buildings, and educational facilities, due to its benefits in saving energy and enhancing indoor environmental quality.

CO2 capture performance of AMP-EAE amine blends: Absorption in the microchannel and desorption from saturated solutions

Blended organic amine solutions are considered an effective strategy for developing highly efficient and low energy-consuming absorbents due to the possibility of combining the advantages of single amine. The 2-amino-2-methyl-1-propanol (AMP) and 2-(ethylamino)ethanol (EAE) amine blends were prepared in three molar ratios: blend-1 (nAMP:nEAE = 3:1), blend-2 (nAMP:nEAE = 1:1), and blend-3 (nAMP:nEAE = 1:3). The impacts of gas-liquid flow rate, amine concentration, molar ratio, temperature, and CO2 concentration on absorption performance were investigated using the serpentine microchannel. Additionally, the effects of amine concentration and molar ratio on the desorption performance of saturated solutions were also explored. The performance of amine blends in absorption and desorption was evaluated by measuring absorption rate, efficiency, and loading, as well as desorption efficiency, energy consumption, cycle capacity, and average desorption rate. The desorption results were compared to those of the benchmark solvent, 30 wt% MEA, under identical operating conditions. The results indicate that the 25 wt% blend-2 solution performs exceptionally well, exhibiting a 15 % increase in absorption efficiency compared to the AMP aqueous solution at a gas-liquid ratio of 20. Additionally, the cycle capacity and average desorption rate are 1.7 times higher than those of the 30 wt% MEA solution. Notably, the energy consumption of the 25 wt% blend-2 solution for desorption is only 60 % of the 30 wt% MEA solution.

Diaminated Cellulose Beads as a Sustainable Support for Industrially Relevant Lipases.

Environmentally persistent polystyrene or polyacrylic beads are used as supports in enzyme large-scale bioprocesses, including conversion glucose isomerization for high-fructose corn syrup production, hydrolysis of lactose, and synthesis of active pharmaceutical ingredients. In this paper, we report the development of a novel sustainable and scalable method to produce diaminated cellulose beads (DAB) as highly efficient alternative supports for industrially relevant lipases. Regenerated cellulose beads were grafted with diaminated aliphatic hydrocarbons via periodate oxidation and reductive amination. The oxidation step indicated that aldehyde content can be easily tuned through the reaction time and concentration of reactants. Reductive amination of dialdehyde cellulose was more efficient as the length of the diaminated hydrocarbon compound increased. Morphological analysis of DAB showed that cellulose chemical grafting enabled the preservation of the bead shape and internal structure upon freeze-drying. Enzymatic degradability studies demonstrated that chemical functionalization did not undermine enzyme cellulose hydrolysis. The addition of aminated moieties on cellulose dramatically increased absorption efficiency for all industrially relevant lipases used, reaching 100% for Thermomyces lanuginosus lipase (TLL). Storage and recyclability experiments demonstrated that enzymes were retained and recyclable for at least nine cycles, although the activity gradually declined after each cycle. Medium chain triacylglycerol hydrolysis in a SpinChem reactor using TLL immobilized on 1,6 DAB exhibited higher activity compared to acrylic beads (588 vs 459 U/g) suggesting that biodegradable cellulose-based materials could be a valid and attractive alternative to plastics carriers.

Enhanced far infrared emissivity, UV protection and near-infrared shielding of polypropylene composites via incorporation of natural mineral for functional fabric development

Far infrared radiation in the range of 4–20 µm has been showed to have biological and health benefits to the human body. Therefore, incorporating far-infrared emissivity additives into polymers and/or fabrics hold promise for the development of functional textiles. In this study, we incorporated nine types of natural minerals into polypropylene (PP) film and examined their properties to identify potential candidates for functional textiles and apparels. The addition of 2% mineral powders into PP film increased the far-infrared emissivity (5–14 µm) by 7.65%-14.48%. The improvement in far-infrared emissivity within the range of 5–14 µm, which overlaps with the peak range of human skin radiation at 8–14 µm, results in increased absorption efficiency, and have the potential to enhance thermal and biological effects. Moreover, the incorporation of mineral powders in PP films exhibited favorable ultraviolet (UV) protection and near-infrared (NIR) shielding properties. Two films, specifically those containing red ochre and hematite, demonstrated excellent UV protection with a UPF rating of 50+ and blocked 99.92% and 98.73% of UV radiation, respectively. Additionally, they showed 95.2% and 93.2% NIR shielding properties, compared to 54.1% NIR shielding properties of PP blank films. The UV protection and NIR shielding properties offered additional advantages for the utilization of polymer composite with additives in the development of sportswear and other outdoor garments. The incorporation of minerals could absorb near-IR radiation and re-emit them at longer wavelength in the mid-IR region. Furthermore, the incorporation of minerals significantly improved the heat retention of PP films under same heat radiation treatment. Notably, films with red ochre and hematite exhibited a dramatic temperature increase, reaching 2.5 and 3.2 times the temperature increase of PP films under same heat radiation treatment, respectively (46.8 °C and 59.9 °C higher than the temperature increase of 20.9 °C in the PP film). Films with additives also demonstrated lower thermal effusivity than PP blank films, indicating superior heat insulation properties. Therefore, polypropylene films with mineral additives, particularly those containing red ochre and hematite, showed remarkable heat capacity, UV-protection, NIR-shielding properties and enhanced far infrared emissivity, making them promising candidates for the development of functional textiles.

Efficiency enhancement of GaAs nanowire array-based solar cell by plasmonic Al nanoparticles

Gallium arsenide (GaAs) nanowire (NW) solar cells (SCs) have piqued the interest of researchers because they exhibit superior light-harvesting and anti-reflection properties along with reduced material consumption compared to their planar counterparts. However, the high surface-to-volume ratio associated with these NWs degrades their performance in practical applications. Light trapping is considered one of the most crucial parameters for producing low-cost high-efficiency NW-SCs. Thus, numerous light-trapping strategies have been explored, among which surface plasmon resonance (SPR) based optical absorption enhancement using metal nanoparticles (NPs) has emerged as a potential method. The role of plasmonic aluminum (Al) NPs in the efficiency enhancement of GaAs NW SC has not yet been explored. Therefore, in this study, a vertically aligned GaAs NW SC structure incorporated with Al NPs has been investigated using the finite-difference time-domain (FDTD) method. The sidewalls of GaAs NWs are embellished with uniformly arranged Al NPs with diameters ranging from 30 to 60 nm. The excitation of localized surface plasmon resonance in metal NPs results in significant light absorption enhancement at the GaAs near-band of the proposed structure. The results demonstrate that even with a low aspect ratio (D/P) of 0.3, optimizing the geometrical parameters of the NPs results in a 41.96 % increase in power conversion efficiency (PCE) and a 45 % increase in absorption efficiency at 800 nm for the proposed structure when compared to the bare structure. Hence, our suggested structure which utilizes the light-trapping mechanism of Al NPs proves to be a cost-effective and promising material combination for high-efficiency nanoscale SCs.

Effects of maternal choline supplementation on performance and immunity of progeny from birth to weaning.

The objectives were to investigate whether supplementation with rumen-protected choline (RPC) during late pregnancy in Holstein cows affects offspring immunity and growth, and whether effects are utero-placental, colostrum dependent, or both. A total of 105 multiparous Holstein cows were assigned randomly to a prepartum diet (1.54 Mcal of NEL/kg of DM, and 15.8% CP) without (control) or with added RPC (12.9 g/d of choline ion). Calves (n = 111) were blocked by sex and assigned randomly to colostrum from control cows or colostrum from RPC cows, resulting in 4 treatments in a 2 × 2 factorial arrangement: (1) calves born and fed colostrum from non-supplemented dams (NN; n = 33); (2) calves from non-supplemented dams and fed colostrum from RPC-fed cows (NC; n = 25); (3) calves from RPC-supplemented dams and colostrum from non-supplemented cows (CN; n = 28); and (4) calves from RPC-supplemented dams and colostrum from RPC-fed cows (CC; n = 25). Growth, intakes, and immunity of females were evaluated up to 56 d of age. Growth and intake of male calves was evaluated up to 35 d of age, and physiological and immune responses to intravenous LPS challenge were evaluated from 21 to 35 d of age. Effects of prenatal and colostrum treatments and interactions between treatments were analyzed using mixed models. Calves fed colostrum from RPC-supplemented dams had a 17.4% increase in apparent efficiency of absorption of IgG compared with calves fed colostrum from control dams (27.4 vs. 23.3%). Incidence of fever in the first 21 d of age tended to be less in females born from RPC-supplemented dams compared with females born from control dams (31 vs. 58%). Prenatal RPC females had increased hematocrit and concentrations of red blood cells, leukocytes, neutrophils, and lymphocytes in blood compared with prenatal females born from control dams. Compared with prenatal control females, prenatal RPC females had greater intake of milk replacer (704 vs. 748 ± 9.9 g/d) and starter (45.4 vs. 60.2 ± 5.9 g/d) during the first 21 d of age. In male calves, mean intake of DM was greater (1,074 vs. 976 ± 45 g/d) after the LPS challenge (0 to 8 d) by calves born from dams fed RPC compared with males born from control dams. Calves born from RPC-fed dams also had lower mean rectal temperature (39.0 vs. 39.2°C) and mean respiration rate (35.6 vs. 39.3 breaths/min) compared with males born from control dams. Moreover, serum concentrations of metabolites (i.e., β-hydroxybutyric acid, fatty acids, and glucose), cytokines (i.e., tumor necrosis factor-α) and acute phase proteins (i.e., serum amyloid A) were consistent with less-severe inflammatory response to LPS in males born from dams fed RPC compared with control. Source of colostrum and interaction between prenatal and colostrum treatments had minimal effects on calf responses to LPS. Overall, maternal RPC supplementation during late gestation suggests a positive effect on immunity, in that colostrum from RPC-fed dams increased efficiency of IgG absorption and maternal supplementation with RPC during late gestation, regardless of colostrum source, attenuated responses to LPS.

Acute High Dietary Phosphorus Following Low-Phosphorus Diet Acclimation Does Not Enhance Intestinal Fractional Phosphorus Absorption in Nephrectomized Male Rats.

Dietary phosphorus restriction and phosphorus binders are commonly prescribed for patients with chronic kidney disease (CKD). However, occurrences of non-adherence to these interventions are common. As low-phosphorus (LP) diets have been consistently experimentally shown in vitro to increase intestinal phosphorus absorption efficiency, a bout of non-adherence to diet or binders may cause an unintended consequence of enhanced intestinal phosphorus absorption. Thus, we aimed to determine the effect of a single bout of high-phosphorus (HP) intake after acclimation to a LP diet. Male Sprague Dawley rats with 5/6 nephrectomy (n=36) or sham operation (n=36) were block-randomized to 1 of 3 diets: LP (0.1% P w/w), HP (1.2%), or LP followed by acute HP (LPHP 0.1% then 1.2%). Phosphorus absorption tests were conducted using 33P radioisotope administrated by oral gavage or intravenously (iv). Although the overall two-way ANCOVA model for intestinal fractional phosphorus absorption was non-significant, exploratory comparisons showed intestinal fractional phosphorus absorption efficiency tended to be higher in rats in the LP compared with HP or LPHP groups. Rats in the HP or LPHP groups had higher plasma phosphorus compared with rats in the LP group, but the LPHP group was not different from the HP group. Gene expression of the major intestinal phosphate transporter, NaPi-2b, was lower in the jejunum of rats in the LPHP group compared with rats in the HP group but not different in the duodenum. These results demonstrate that an acute HP load after acclimation to a LP diet does not lead to enhanced intestinal fractional phosphorus absorption efficiency in 5/6 nephrectomized male rats. These data provide evidence against the notion that dietary phosphorus restriction or binder use adversely increases absorption efficiency after a single instance of dietary or binder non-adherence. However, other adverse consequences of fluctuating dietary phosphorus intake cannot be ruled out. © 2022 The Authors. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research.

Spectroscopic and magnetic investigations of the dilute magnetically doped semiconductors BaSn1-xMnxO3 (0.02 ≤ x ≤ 0.1)

Dilute magnetically doped semiconductors (DMSs) are key to fabricating novel spintronic devices with high functionalities, which could be utilized for the next-generation technological development. BaSnO3 is a transparent wide band gap (∼3.1 eV) semiconductor, in which magnetism can be induced through a subtle amount of magnetic impurity doping without deterring its optical transparency. In this work, we report an experimental investigation on the optical spectroscopic and magnetic properties of the DMSs BaSn1-xMnxO3 (0 ≤ x ≤ 0.1), synthesized using standard solid-state-reaction method at high-temperature and ambient pressure, through various spectroscopic, electron paramagnetic resonance (EPR) and temperature- and field-dependent magnetization measurements. All samples are found to be crystallize in the cubic structure with space group Pm3‾m, in which Mn ions are stabilized in the 4+ valence state. We find that the optical band gap monotonically decreases (from 3.1 eV to 2.08 eV) with increase in Mn doping concentration, which in turn leads to an increase in absorption efficiency in the visible region. An enhanced sp-d hybridization between localized d electrons of Mn ions and band electrons is likely the main reason for such band gap reduction. Interestingly, theoretical simulation of EPR spectra suggests that the signal is primarily arising from a combination of two spin systems, i.e., Mn4+ ions and singly ionized oxygen vacancies. The strength of magnetic interaction between Mn4+ ions is also increased for higher doped samples. Moreover, the nature of magnetic interaction is predominantly antiferromagnetic in higher doped samples, as corroborated by the negative value of Curie-Weiss temperature from the inverse susceptibility fitting.

Spectroscopic properties of alkali borate glasses containing Cu2+

Binary alkali borate glasses R2O-B2O3 (R = Li, Na or K) are a model system for oxide glasses due to the major modification of their structure and properties with alkali concentration. The present study correlates optical absorption and electron paramagnetic resonance (EPR) spectroscopy data on binary alkali borate glasses containing Cu2+ in the range 10-33 mol% alkali oxides. These glasses show a color change from light cyan to sky blue with increasing alkali content. The chemical dependence of the spectroscopic properties of Cu2+ in alkali borate glasses is different from what is observed for other divalent transition metal ions (Ni2+, Co2+): (i) there is no change in the coordination of Cu2+ as a function of alkali content, confirming that tetrahedral Cu2+ is rather rare in these glasses as in crystalline oxide materials; (ii) as a consequence, the color change of Cu2+-containing glasses as a function of their chemical composition remains limited; (iii) cation field strength does not significantly influence the spectroscopic properties of Cu2+, the alkali content being the main chemical parameter governing Cu2+ speciation in these glasses; (iv) there is no clustering of Cu2+ ions in low-alkali borate glasses. By correlating the data obtained from optical absorption spectroscopy and from EPR, information is gained on the variation of Cu-site geometry as a function of the alkali content of the glass. In low-alkali glasses, the Cu2+ sites show a higher distortion than in high-alkali glasses and their coordination geometry is less distributed. This may indicate that these sites are connected with rigid superstructural borate units of these glasses. The spectroscopic parameters of Cu2+ in low-alkali glasses show also a noteworthy similarity with those of aqueous Cu2+ complexes. The smaller site distortion in high-alkali glasses is accompanied by a more covalent character of the Cu2+-O π bonds, resulting from a weakening of the B-O bonds that is caused by the progressive conversion of [3]B to [4]B with increasing alkali content. The color of the glasses changes from light cyan to sky blue due to the increase in absorption efficiency in the red portion of the visible spectrum. Indeed, in high-alkali glasses, a greater distribution of the Cu2+ sites causes a broadening of the Cu2+ absorption band. These modifications are explained by considering the influence of axial ligands on the distortion of Cu2+ sites. The intensity of this axial distortion governs the anisotropy of the Cu2+ sites, even if the contribution of axial ligands to the local charge balance of Cu2+ remains minor. The speciation of cupric ions in alkali borate glasses, as derived from this spectroscopic approach, is consistent with a bond-valence model. As these ions are used widely as a structural probe in crystals and glasses, such a combined approach may shed light on the local environment of Cu2+ in oxide glasses.

Impact of the foliar application of potassium nanofertilizer on biomass, yield, nitrogen assimilation and photosynthetic activity in green beans

The agricultural areas of the world face problems that create difficulties when producing food and the excessive use of fertilizers is generating a negative environmental impact. An alternative that appears as a solution to this problem is the use of nanofertilizers. Within nanofertilizers an area of opportunity is the application of macronutrients, which report an increase in absorption efficiency of 19% compared to conventional fertilizers. Potassium (K) is one of the three macronutrients most used in agriculture and its deficiency affects key processes in plant development, limiting crop production. However, the number of publications where K is used as a nanofertilizer is limited, despite this, products in this form are already on the market. Therefore, the aim of this research work was to study the effect of the foliar application of K nanofertilizer on biomass, yield, nitrogen assimilation and photosynthetic activity in green beans cv. ‘Strike’. K was applied in the form of a nanofertilizer in doses of 0, 50, 100 and 200 ppm. The biomass accumulation, yield, nitrate reductase enzyme activity, photosynthetic activity and photosynthetic pigments were evaluated. The dose of 100 ppm of K nanofertilizer obtained a higher accumulation of biomass, nitrate reductase activity, photosynthetic activity, SPAD values and total chlorophyll content. While the 200-ppm dose obtained a higher increase in yield. The results obtained suggest that the application of K nanofertilizers benefits the physiological development of plants. However, more studies are required to compare the application of nanofertilizers with traditional fertilizers.

Artificial light at night (ALAN) causes variable dose-responses in a sandy beach isopod.

Artificial Light at Night (ALAN) is expanding worldwide, and the study of its influence remains limited mainly to documenting impacts, overlooking the variation in key characteristics of the artificial light such as its intensity. The potential dose-response of fitness-related traits to different light intensities has not been assessed in sandy beach organisms. Hence, this study explored dose-responses to ALAN by exposing the intertidal sandy beach isopodTylos spinulosusto a range of light intensities at night: 0 (control), 20, 40, 60, 80 and 100lx. We quantified the response of this species at the molecular (RNA:DNA ratios), physiological (absorption efficiency) and organismal (growth rate) levels. Linear and non-linear regressions were used to explore the relationship between light intensity and the isopod response. The regressions showed thatincreasing light intensity caused an overall ~ threefold decline in RNA:DNA ratios and a ~ threefold increase in absorption efficiency, with strong dose-dependent effects. For both response variables, non-linear regressions also identified likely thresholds at 80lx (RNA:DNA) and 40lx (absorption efficiency). By contrast, isopod growth rates were unrelated (unaltered) by the increase in light intensity at night. We suggest that ALAN is detrimental for the condition of the isopods, likely by reducing the activity and feeding of these nocturnal organisms, and that the isopods compensate this byabsorbing nutrients more efficiently in order to maintain growth levels.

Simulating 50 keV X-ray Photon Detection in Silicon with a Down-Conversion Layer

Simulation results are presented that explore an innovative, new design for X-ray detection in the 20–50 keV range that is an alternative to traditional direct and indirect detection methods. Typical indirect detection using a scintillator must trade-off between absorption efficiency and spatial resolution. With a high-Z layer that down-converts incident photons on top of a silicon detector, this design has increased absorption efficiency without sacrificing spatial resolution. Simulation results elucidate the relationship between the thickness of each layer and the number of photoelectrons generated. Further, the physics behind the production of electron-hole pairs in the silicon layer is studied via a second model to shed more light on the detector’s functionality. Together, the two models provide a greater understanding of this detector and reveal the potential of this novel form of X-ray detection.

Computer materials science of electrical construction composite materials with specified properties

This article is devoted to computer materials science of electrical construction composite materials for obtaining materials with specified properties. The idea, principles and distinctive features of computer materials science are given. An approach to solving a number of problems is described, which makes it possible to fully take into account the presence of random elements that are present in the process of forming composite materials. Implementation of algorithms is implemented, in which results obtained in previous stages affect progress of algorithms execution in subsequent stages. The radar absorbing material is considered in detail using the example of radar absorbing concrete. It has been proved that with multi-factor dependence, it is possible to optimize the composition only using an automated computer system that calculates the composition of the concrete mixture. One possible computer material science problem has shown that in order to increase absorption efficiency, it is necessary to substantially increase the effective absorption volume, which can be achieved by increasing the non-conductive layers in order to reduce the through conductivity of the radar absorbent concrete, i.e., as if to break the material into a large number of small electromagnetic screens. In this case, the volume of interaction of the material with the electromagnetic field extends deep into the material and is made commensurate with the size of the sample. In conclusion, a possible list of tasks and directions for the development of computer materials science is presented.

Rational Design and Simulation of Two-Dimensional Perovskite Photonic Crystal Absorption Layers Enabling Improved Light Absorption Efficiency for Solar Cells

A two-dimensional perovskite photonic crystal structure of Methylamine lead iodide (CH3NH3PbI3, MAPbI3) is rationally designed as the absorption layer for solar cells. The photonic crystal (PC) structure possesses the distinct “slow light” and band gap effect, leading to the increased absorption efficiency of the absorption layer, and thus the increased photoelectric conversion efficiency of the battery. Simulation results indicate that the best absorption efficiency can be achieved when the scattering element of indium arsenide (InAs) cylinder is arranged in the absorption layer in the form of tetragonal lattice with the height of 0.6 μm, the diameter of 0.24 μm, and the lattice constant of 0.4 μm. In the wide wavelength range of 400–1200 nm, the absorption efficiency can be reached up to 82.5%, which is 70.1% higher than that of the absorption layer without the photonic crystal structure. In addition, the absorption layer with photonic crystal structure has good adaptability to the incident light angle, presenting the stable absorption efficiency of 80% in the wide incident range of 0–80°. The results demonstrate that the absorption layer with photonic crystal structure can realize the wide spectrum, wide angle, and high absorption of incident light, resulting in the increased utilization efficiency of solar energy.

Ultrafast electron transfer dynamics in Ag/TiO2 nanocomposite for tailoring of optical nonlinearity

The nanocomposite of titanium dioxide (TiO2) with noble metallic nanoparticles (NPs) are widely used catalysis systems for various photonic applications owing to the well-known ultrafast dynamics process, electron transfer. In this work, the traditional electron transfer mechanism is further improved based on the nanocomposite chip with embedded Ag NPs in TiO2 semiconductor (AgNP:TiO2). Considering the increased absorption efficiency of Ag NPs, the delay time of electron-electron scattering and electron-phonon scattering are measured to indicate the evidence of electron transfer process. It is proved that the enhancement of optical nonlinearity is closely associated with the hot electron transfer between TiO2 and Ag NPs. Benefiting from the electron transfer mechanism induced nonlinearity tailoring of TiO2, low-threshold mode-locked lasers have been realized with AgNP:TiO2 as saturable absorber (SA) with low saturation intensity (decreased by 76.5%). This work not only fills the blank of optical nonlinearity modification by embedded Ag NPs in TiO2 nanocomposites, but also build a bridge between hot electron transfer process and nonlinearity tailoring, suggesting potential applications in ultrafast dynamics and optoelectronics.

Investigations on performance and spectroscopic capabilities of a 3 mm CdTe Timepix detector

High Z sensor materials such as GaAs, CdZnTe or CdTe provide high absorption efficiency for radiation caused by radioactive sources and are therefore suited for the usage in radiation detection devices like gamma cameras. An increase in sensor layer thickness enhances the absorption efficiency further but increases unwanted effects like charge sharing. This work presents the characterization and performance of the first 3 mm CdTe sensor connected to a readout chip of the Medipix/Timepix detector family. The parameters of a developed cluster analysis are shown to fully utilize the detector configuration in a gamma camera. Spectroscopic measurements regarding the common radioactive sources 60Cobalt, 137Cesium, 152Europium and 241Americium are investigated. The absorption efficiency of the 3 mm CdTe sensor is compared to a 0.45 mm CdTe and a 1 mm CdTe detector configuration. The charge sharing effect is successfully reduced with cluster analysis and the thicker sensor profits significantly from the increased absorption efficiency, especially in higher energy ranges (> 100 keV). The information gain of the charge sharing effect regarding cluster size and shape can be further used for identification of the investigated isotopes.

Preparation of NiO/TiO2 Composite Films for Enhanced Dye Sensitized Solar Cell Efficiency

Abstract Spray pyrolysis technique has been applied for preparing many kinds of thin films because this technique offers a lot of advantages, such as inexpensive cost, uncomplicated process and large scale production. Therefore, the spray pyrolysis technique is used for making pure TiO2 and NiO/TiO2 composite films in this report. A NiO/TiO2 composite film is getting attention to be used as a compact layer in dye sensitized solar cell (DSSC) because NiO can be used as a hole collector and a barrier for energy recombination properties. Moreover, the NiO/TiO2 composite film exhibits superhydrophilic properties that can increase absorption efficiency for a dye solution. This study has an objective to improve the efficiency of DSSC by changing the ratio of NiO/TiO2 in the composite films. The pure TiO2 and NiO/TiO2 composite films were prepared at 200℃ by spray pyrolysis technique using a Ti(OCH(CH3)2)4 solution and a mixture of Ti(OCH(CH3)2)4 solution with Ni(NO3)2•6H2O powder, respectively. The effect of the ratio between Ni(NO3)2•6H2O powder and Ti(OCH(CH3)2)4 solution (0.5 atm%, 1 atm%, 2 atm%, and 4 atm% of Ni(NO3)2•6H2O) on the efficiency of DSSCs were studied. The surface morphology, crystal structure and optical properties of TiO2 and NiO/TiO2 composite films on FTO and glass substrates were characterized by using field-emission scanning electron microscope (FE-SEM), X-ray diffractometer (XRD), and UV-VIS spectrophotometer, respectively. The FE – SEM images showed that the films were smooth surface and dense when prepared at 200 ℃. The XRD results of TiO2 and NiO/TiO2 composite films on the FTO substrates showed that the TiO2 crystals were anatase phase because the peak at 25.30 corresponds to (101) planes of anatase. The spectrophotometer results showed that the optical transmittance for all samples were about 80%. For the energy conversion efficiency characterization, it was found that the NiO/TiO2 composite films that were prepared from 0.5 atm% of Ni(NO3)2•6H2O solution had the better energy conversion efficiency than TiO2 films.

Preparation and Characterization of Gradient Compressed Porous Metal for High-Efficiency and Thin-Thickness Acoustic Absorber.

Increasing absorption efficiency and decreasing total thickness of the acoustic absorber is favorable to promote its practical application. Four compressed porous metals with compression ratios of 0%, 30%, 60%, and 90% were prepared to assemble the four-layer gradient compressed porous metals, which aimed to develop the acoustic absorber with high-efficiency and thin thickness. Through deriving structural parameters of thickness, porosity, and static flow resistivity for the compressed porous metals, theoretical models of sound absorption coefficients of the gradient compressed porous metals were constructed through transfer matrix method according to the Johnson–Champoux–Allard model. Sound absorption coefficients of four-layer gradient compressed porous metals with the different permutations were theoretically analyzed and experimentally measured, and the optimal average sound absorption coefficient of 60.33% in 100–6000 Hz was obtained with the total thickness of 11 mm. Sound absorption coefficients of the optimal gradient compressed porous metal were further compared with those of the simple superposed compressed porous metal, which proved that the former could obtain higher absorption efficiency with thinner thickness and fewer materials. These phenomena were explored by morphology characterizations. The developed high-efficiency and thin-thickness acoustic absorber of gradient compressed porous metal can be applied in acoustic environmental detection and industrial noise reduction.

Life Cycle of Wash Oil for Benzol Absorption from Coke Oven Gas

AbstractAn important source of benzol is coke oven gas, which is a by‐product of metallurgical coke production. A cycle of absorption into the washing oil and reverse desorption is a crucial step in this technology. The wash oil itself is a complex mixture of hydrocarbons with higher boiling point. Its washing property is changing during time of use. The concentration of unabsorbed benzene in the coke oven gas leaving the absorption is monitored as an indicator of the washing oil condition. A secondary parameter is the viscosity of the washing oil. The optimal operating conditions of the absorption unit of benzol and the ranges of physical properties, which mainly influence the benzol absorption, were identified. Beside the increasing absorption efficiency, it is significant to prolong the life cycle of wash oil.

Optimization of monoethanolamine for CO2 absorption in a microchannel reactor

In this study, CO2 absorption was performed using a MEA aqueous solution in a circular microchannel, with a diameter of 800 μm and a length of 25 cm. All experiments were carried out at atmospheric pressure with a concentration of 10% molar CO2 in the feed gas. The operational variables were temperature (15–55 °C), input solvent flow rate (0–0.04 l min−1), inlet gas flow rate (1–9 l.min−1), and MEA concentration in the solvent (0–40 wt.%). The results showed that by increasing the concentration of MEA in the solvent, and increasing the solvent flow rate, a significant increase occurred in the absorption percentage and overall gas-based volumetric mass transfer coefficient. Increasing the gas flow rate also caused a reduction in the absorption percentage and an increase in the overall gas-based volumetric mass transfer coefficient. However, the operating temperature within a range of 15–55 °C did not have a significant impact on absorption rate. In optimal operating conditions, the absorption percentage was 100%, and the overall gas-based volumetric mass transfer coefficient of 2685 (kmol h−1 m-3 kPa−1) was reached. The overall gas-based volumetric mass transfer coefficient indicates that, compared with other mass transfer devices, the use of a microchannel-reactor resulted in a higher level of increase in absorption efficiency.