Indonesia has been blessed with excellent solar heat distribution, which can be used as renewable energy to heat water. Various technologies have been developed to utilize these inexhaustible thermodynamic resources, in the form of photons arrays, converted into concentrated heat for daily use, i.e., solar water heater. This renewable-based water heating system can provide significant energy efficiency, benefit the environment, and reduce energy use costs. This experimental study attempts to harvest the energy from the sun using a cylindrical through collector (CTC) type solar concentrator. The CTC was made of the solar reflective film (SRF) affixed to concentrator collector surfaces which was then mounted on an adjustable angle frame of the concentrator collector support. The heat generated from the concentrator was stored in water, and phase change material is embedded in the system to retain the heat longer. The research was carried out in Langsa City, Aceh, Indonesia. The results showed that water heaters using CTC systems could produce 16 L of hot water retained at 40–60 °C for four hours. With the addition of beeswax, the water temperature of the same capacity can be maintained at 40–60 °C for around 5 h. This technology demonstrated an excellent result that produces as much as 60 L of water per day, increasing solar thermal energy efficiency. This technology presented a great potential for replication or even for further development on an industrial scale. 相似文献
A small series of nitro group-bearing enamides was designed, synthesized (NEA1–NEA5), and evaluated for their inhibitory profiles of monoamine oxidases (MAOs) and β-site amyloid precursor protein cleaving enzyme 1 (β-secretase, BACE1). Compounds NEA3 and NEA1 exhibited a more potent MAO-B inhibition (IC50 value = 0.0092 and 0.016 µM, respectively) than the standards (IC50 value = 0.11 and 0.14 µM, respectively, for lazabemide and pargyline). Moreover, NEA3 and NEA1 showed greater selectivity index (SI) values toward MAO-B over MAO-A (SI of >1652.2 and >2500.0, respectively). The inhibition and kinetics studies suggested that NEA3 and NEA1 are reversible and competitive inhibitors with Ki values of 0.013 ± 0.005 and 0.0049 ± 0.0002 µM, respectively, for MAO-B. In addition, both NEA3 and NEA1 showed efficient BACE1 inhibitions with IC50 values of 8.02 ± 0.13 and 8.21 ± 0.03 µM better than the standard quercetin value (13.40 ± 0.04 µM). The parallel artificial membrane permeability assay (PAMPA) method demonstrated that all the synthesized derivatives can cross the blood–brain barrier (BBB) successfully. Docking analyses were performed by employing an induced-fit docking approach in the GLIDE module of Schrodinger, and the results were in agreement with their in vitro inhibitory activities. The present study resulted in the discovery of potent dual inhibitors toward MAO-B and BACE1, and these lead compounds can be fruitfully explored for the generation of newer, clinically active agents for the treatment of neurodegenerative disorders. 相似文献
Natural frequencies are important dynamic characteristics of a structure. Therefore, the exact solution pertaining to free vibration of stepped circular plate elastically restrained against rotation, translation, and internal elastic ring support resting on an arbitrary variable elastic foundation using Green Function is presented in this paper. Thus, an accurate and direct modeling technique is introduced for modeling stepped circular plate on an arbitrary variable elastic foundation with arbitrary boundary conditions and internal elastic ring support. The effect of the translational along with rotational support flexibilities, as well as, the elastic coefficient of Winkler foundation and other parameters are assessed. Finally, some numerical examples are shown in order to present the efficiency and simplicity of the Green Function in the new formulation. 相似文献
This note looks at the two similarity solutions of the Navier Stokes equations in polar coordinates. In the second solution an initial value problem is reduced into generalized stationary KDV and hence integrable. 相似文献
Two simple and sensitive methods for the determination of indapamide in pure and in dosage forms are developed. These methods
are based on the oxidation of indapamide with iron(III) in acidic medium. The liberated iron(II) reacts with 1,10-phenanthroline
(Method A) and the ferroin complex is colorimetrically measured at λmax 509 nm against reagent blank. Method B is based on the reduction of Fe(III) by the drug. Iron(II) forms a colored complex
(λmax 522 nm) with 2,2′-bipyridyl. Optimization of the experimental conditions is described. Beer’s law is obeyed in the concentration
range 1.0–12 μg ml−1 and 4.0–18 μ g ml−1 for A and B, respectively. The apparent molar absorptivity and Sandell sensitivity for method A is 3 × 104 L mol−1 cm−1 and 0.0188 μ g cm−2, while for method B is 2.3 × 104 L mol−1 cm−1 and 0.0159 μg cm−2. The detection and quantification limits are calculated. The developed methods are applied successfully for the determination
of indapamide in pure and in tablet form without interference from common excepients.
Received November 10, 2000. Revision April 6, 2001. 相似文献
Photodynamic therapy (PDT) is a light-based cancer therapy approach that has shown promising results in treating various malignancies. Growing evidence indicates that cancer stem cells (CSCs) are implicated in tumor recurrence, metastasis, and cancer therapy resistance in colorectal cancer (CRC); thus, targeting these cells can ameliorate the prognosis of affected patients. Based on our bioinformatics results, SOX2 overexpression is significantly associated with inferior disease-specific survival and worsened the progression-free interval of CRC patients. Our results demonstrate that zinc phthalocyanine (ZnPc)-PDT with 12 J/cm2 or 24 J/cm2 irradiation can substantially decrease tumor migration via downregulating MMP9 and ROCK1 and inhibit the clonogenicity of SW480 cells via downregulating CD44 and SOX2. Despite inhibiting clonogenicity, ZnPc-PDT with 12 J/cm2 irradiation fails to downregulate CD44 expression in SW480 cells. Our results indicate that ZnPc-PDT with 12 J/cm2 or 24 J/cm2 irradiation can substantially reduce the cell viability of SW480 cells and stimulate autophagy in the tumoral cells. Moreover, our results show that ZnPc-PDT with 12 J/cm2 or 24 J/cm2 irradiation can substantially arrest the cell cycle at the sub-G1 level, stimulate the intrinsic apoptosis pathway via upregulating caspase-3 and caspase-9 and downregulating Bcl-2. Indeed, our bioinformatics results show considerable interactions between the studied CSC-related genes with the studied migration- and apoptosis-related genes. Collectively, the current study highlights the potential role of ZnPc-PDT in inhibiting stemness and CRC development, which can ameliorate the prognosis of CRC patients. 相似文献
In this paper, an upper bound analysis is developed to calculate the rolling torque in the wire flat rolling process. Streamlines are defined parametrically in the deforming region and the formulation of the admissible velocity field are developed. The internal and frictional power terms are obtained from the upper bound solution. Through the analysis, the rolling torque is obtained. Furthermore, the effects of the roll speed, wire diameter, and reduction in height on the rolling torque are studied. In addition, the experimental and numerical investigations are performed to verify the proposed theoretical model. A very good agreement is obtained between the analytical results with those from the simulation and the experiment.
Nonlinear Dynamics - The objective of this study is to develop, simulate and verify experimentally a model of a nonlinear spring, based on the principle of a cantilevered beam with a mass on its... 相似文献