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1.
In this study, a novel Automated Composite Table Algorithm (ACTA) is developed for targeting the water regeneration–recycle network of single contaminant problem. The ACTA is based on Pinch Analysis, but is automated by taking into consideration the possibility of zero liquid discharge (ZLD) for the water network. In the existing literature, the targeting procedure for ZLD network is based on the graphical tool of Limiting Composite Curve (LCC). However, identification of key parameters (i.e. freshwater, wastewater, regenerated water flowrates, along with pre-regeneration concentrations) is very tedious for highly integrated water network system. The magnification around the turning point of LCC is required to identify the correct pinch points and targeting procedure is done iteratively until the reliable network targets can be determined. These limitations are now overcome by the ACTA, which is an improved version of Composite Table Algorithm that is capable of identifying key parameters algebraically for a given post-regeneration concentration. The newly developed ACTA is capable of handling a wide range of problems including ZLD and non-ZLD network, for both fixed load and fixed flowrate problems.  相似文献   

2.
Over the past two decades, various process integration tools have been developed for the synthesis of material resource conservation network (RCN), ranging from pinch analysis and mathematical programming techniques. Note, however, that most of these techniques were developed for grassroots design problems. In other words, the process plants are still at the design stage where the RCN does not exist yet. The grassroots design techniques are not directly applicable for existing process plants that are in operation. For the latter, some degrees of resource conservation may have been in place, though the RCNs of these process plants may not be designed systematically. Hence, this calls for the development of a systematic retrofit procedure in order to reduce both fresh resource and waste discharge flowrates for the process plants. In this work, a three-step procedure based on pinch analysis is proposed for the retrofit of existing RCNs, focusing on direct reuse/recycle scheme for single contaminant problems. A new analysis tool known as the loadflowrate diagram is proposed for the analysis of impurity load received by the material sinks. This tool helps to identify suitable sinks where unutilised sources may be recovered to. Besides, a revised nearest neighbour algorithm is proposed for the revamping of sink-source matches in the RCN. Several literature examples involving water and hydrogen networks are solved to elucidate the newly proposed procedure.  相似文献   

3.
Pinch Analysis is an established method for enhancing the sustainability of industrial processes via efficient use of various resources. It is based on the principle of target identification followed by subsequent system design aided by a problem decomposition strategy based on the Pinch Point. This approach has recently been extended to apply to a broad range of structurally analogous problems in various domains, such as financial management and carbon-constrained energy planning. In this work, a novel graphical methodology for industrial safety risk and environmental management is proposed. In this method, it is assumed that a set of risk or pollution reduction measures is available, and that each measure is characterized by its implementation cost and the degree of benefit that it delivers. These data are then used to generate a source composite curve. Targeting can then be achieved by shifting this curve relative to a pre-defined sink composite curve, which represents the locus of the plant management’s “willingness to pay,” or budget relative to benefits with respect to risk or pollutant reduction. The methodology is then demonstrated on two case studies. The first case is based on the well-known Bhopal incident, while the second case focuses on the reduction of airborne fluoride emissions from brick firing plant.  相似文献   

4.
Some researchers formerly provided the mechanical, physical, and attenuation properties of the fabricated EremurusRhizophora spp. particleboard phantom. In this study, the percentage depth dose (PDD) and the half value layer (HVL) of fabricated EremurusRhizophora spp. particleboard phantom were determined and compared with those of Perspex and water phantoms, with the same standard phantom size (30 cm?×?30 cm?×?30 cm) in the diagnostic energy range using TLD 100H. In addition, the energy range of X-ray was in diagnostic range of energy. The results indicated that the PDD and HVL of the fabricated EremurusRhizophora spp. particleboard phantom were close to those of the Perspex phantom. Likewise, the PDD and HVL of the fabricated EremurusRhizophora spp. particleboard phantom were found in good agreement with those of water phantom. According to the results of this study, the fabricated EremurusRhizophora spp. particleboard phantom can be used as medical phantoms.  相似文献   

5.
In the present study, β-cyclodextrin-grafted chitosan nanoparticles (β-CD-g-CS NPs) were prepared using a new ionic gelation strategy involving a synergistic effect of NaCl (150 mmol/L), 4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid (HEPES, 10 mmol/L), and water bath sonication. This new strategy afforded smaller and more monodisperse β-CD-g-CS NPs vs. the classical ionic gelation method. New HA/β-CD-g-CS NPs were also prepared using the above-mentioned strategy by adding hyaluronic acid (HA) to the β-CD-g-CS copolymer at different weight ratios until the ZP values conversion. The best result was obtained with the weight ratio of w(HA):w(β-CD-g-CS) = 2:1 and furnished new spherical and smooth HA/β-CD-g-CS NPs. Furthermore, the stability of β- CD-g-CS NPs and HA/β-CD-g-CS NPs at 4°C in physiological medium (pH 7.4) was compared for 3 weeks period and showed that HA/β-CD-g-CS NPs were more stable all maintaining their monodispersity and high negative ZP values compared to β-CD-g-CS NPs. Finally, preliminary study of HA/β-CD-g-CS NPs as carrier for the controlled release of the anticancer drug doxorubicin was investigated. These new HA/β-CD-g-CS NPs can potentially be used as drug delivery and targeting systems for cancer treatment.  相似文献   

6.
We have reviewed the methods of extracting current density dependence of the effective activation energy Ueff(J) from experimental data, including transport measurements and magnetic relaxations. Then we applied the method proposed by Maley etc. on our single-phase HgBaCaCuO-1223 sample to obtain the effective activation energy. The effective activation energy Ueff(J, H = 1~T) is extracted from the magnetization relaxation data. On the other hand, Ueff(J) can be theoretically estimated for the model of a sinusoidal washboard potential in superconductors. By comparing the two results we believe that the single curve obtained in the former way can be seen as real current density dependence of effective activation energy Ueff(J). In addition, we have analyzed the reasons why the magnetic decay data at various temperatures can be scaled onto a single curve. The pinning mechanism in the measured temperature range does not change, and the activation energy depends separately on the three variables: T, B, and J are thought as two important factors for this. In the temperature close to zero and near Tc, thermally assisted flux motion would no longer valid since other processes predominate.  相似文献   

7.
Layered α-form ZrNX (X: Cl and Br) compounds with high quality were prepared by chemical vapor transport. The intercalation of alkali metal A (A: Li, Na, K, Rb) was carried out to realize electron doping into the orthogonal [Zr2N2] layers. The Rietveld refinement analysis reveals that the [Zr2N2] crystalline layers in the intercalation compounds shift mutually in the ab plane when compared with the hosts. Magnetic measurements show that the intercalation compounds A x ZrNX are changed into superconductors with transition temperature T c of up to 12 K. Upon the cointercalation of solvent molecules such as THF, T c decreases to as low as 6.1 K with increasing the interlayer spacing d up to 14 Å, which is similar to the d dependence of T c recently found in electron-doped α-form TiNX series. We also succeeded in synthesizing another new polymorph of α-Zr2N2S by the topochemical reaction between α-form ZrNX and Na2S. α-Zr2N2S (space group: Immm, a = 4.1375(1) Å, b = 3.5422(1) Å, and c = 11.5204(3) Å) has the same α-[Zr2N2] layers, whereas the interlayer spacing between two adjacent [Zr2N2] layers is effectively decreased by 1/3 when compared with the parent compounds of ZrNX.  相似文献   

8.
Kinetic-theory, with the assumption of equipartition of granular energy, suggests that the pressure and viscosity of a granular mixture vary monotonically with the mass-ratio. Our simulation results show a non-monotonic behaviour that can be explained qualitatively by a simple model allowing for non-equipartition of granular energy between the species with different mass.  相似文献   

9.
Based on a sample of 189 expatriate managers working for a non-profit organization (NPO), we pursue two objectives in this paper. First, we address the lack of knowledge on expatriates working in the non-profit sector by exploring their dominant career anchors. Our analysis reveals that the dominant anchors are internationalism, dedication to a cause, and lifestyle. Second, we draw on person-environment fit theory to theorize and test the previously unexplored linkages between expatriates’ career anchors and cross-cultural adjustment (CCA). Our analysis shows that different career anchors are positively associated with different dimensions of CCA: autonomy, security, dedication to a cause, and pure challenge with general living adjustment; dedication to a cause, pure challenge, and internationalism with interactional adjustment; and functional competence, managerial competence, pure challenge, and internationalism with work adjustment. Overall, the study is one of the first attempts to explore career anchors and their linkages to CCA among expatriates in NPOs.  相似文献   

10.
We have taken into consideration the Eliashberg equations based on the electron-phonon and the electron-electron-phonon interaction. It has been shown that the Eliashberg equations set generalizes the model based on the canonical transformation, which for the cuprates quantitatively associates with each other the critical temperature (T C ), the Nernst temperature (T ??), and the energy gap at 0 K. Next, we have derived the analytical formulas for the basic thermodynamic parameters. The conducted analysis allowed to designate the T C - T ?? diagram. Finally, we found the limitation from below for the value of T ??, occurring for the critical temperature higher than 150 K.  相似文献   

11.
Forming limit diagram (FLD) is an important performance index to describe the maximum limit of principal strains that can be sustained by sheet metals till to the onset of localized necking. It is useful tool to access the forming severity of a drawing or stamping processes. In the present work, FLD has been determined experimentally for Ti-6Al-4 V alloy at 400 °C by conducting a hemispherical dome test with specimens of different widths. Additionally, theoretical FLDs have been determined using Marciniak Kuczynski (M-K) model. Various yield criteria namely: Von Mises, Hill 1948, Hill 1993 and Cazacu Barlat in combination with different hardening models viz., Hollomon power law (HPL), Johnson-Cook (JC), modified Johnson-Cook (m-JC), modified Arrhenius (m-Arr.), modified Zerilli–Armstrong (m-ZA) have been used in M-K analysis for theoretical FLD prediction. The material properties required for determination of yield criteria and hardening models constants have been calculated using uniaxial tensile tests. The predicted theoretical FLDs results are compared with experimental FLD. It can be observed that influence of yield criterion in M-K analysis for theoretical FLD prediction is predominant than the hardening model. Based on the results; it is observed that the theoretical FLD using Cazacu Barlat and Hill 1993 yield criteria with m-Arr. hardening model has a very good agreement with experimental FLD.  相似文献   

12.
The present study focuses on the green synthesis of silver nanoparticles using aqueous extract of Cardiospermum halicacabum. AgNPs were confirmed by UV–Visible spectrophotometer analysis showed SPR at 424 nm. FT-IR analysis revealed biomolecules capping of the AgNPs. XRD pattern of synthesized AgNPs was found in face-centered-cubic crystal structure and average crystal size was 23 nm. SEM analyses of the synthesized AgNPs determine the spherical shape and EDX spectra confirmed the presence of silver ions. DLS studies revealed that the synthesized AgNPs showed the average size as 74 nm and Zeta potential value of AgNPs was ?34 mv. The C. halicacabum leaf extract synthesized AgNPs efficiency were tested against different bacterial pathogens MTCC-426 Proteus vulgaris, MTCC-2453 Pseudomonas aeruginosa, MTCC-96 Staphylococcus aureus, MTCC-441 Bacillus subtilis and MTCC-735 Salmonella paratyphi, and fungal pathogens Alternaria solani and Fusarium-oxysporum. The antioxidant ability of the AgNPs was tested and the results showed significant DPPH, hydroxyl and superoxide, radical scavenging activities.  相似文献   

13.
A good deal of information regarding the synthesis and optical properties of chemically grown (Cd1?x Sn x )S (x = 0.01–0.40) thin film has been reported. The growth of these films depends on various preparative parameters and deposition conditions. The reactant concentration, pH, deposition temperature, and rate of agitation were found to influence significantly the quality and thickness of the films. The photoconductive studies have been done with the help of rise and decay curves. Lifetime, mobility, and trap depth are calculated for observed parameters. Band gap measurements for the prepared films have been done with the help of optical transmission spectra using UV-VIS-IR spectrophotometer (190–1100 Å). Interesting results of PC rise and decay studies, optical absorption, and transmission spectra have been presented and discussed. Mobility is influenced significantly by Sn composition. The action spectra showed displacement in the absorption edge towards lower energy side by the addition of Sn mole content. The energy gap decreased from 2.1 to 1.9 eV for x = 0.01 and 1.85 eV for x = 0.02.  相似文献   

14.
15.
Nimustine, a chloroethyl nitrosourea derivative (CENU), is an antineoplastic agent, which is used for the treatment of various types of cancer. The present study focuses on the prediction and investigation of binding properties of nimustine with DNA using molecular modeling and UV–Visible spectroscopic technique. The docking study show that nimustine plausibly binds within the major groove of DNA. Further analysis of docking suggests direct interaction of nimustine with the moieties of heterocyclic nitrogenous bases of DNA. The free binding energy value of the best nimustine-DNA docked conformer is predicted as ?4.31 kcal/mol using docking results.The molecular modeling study also reveals that the interaction between nimustine and DNA is majorly governed by van der Waals forces, hydrogen bonding and hydrophobic interactions, whereas the contribution of electrostatic forces stands negligible. Further, UV–Visible spectra of free calf thymus DNA and its complexes with varying concentration of nimustine indicate the binding constant (K a ) value as 3.27 × 103 M?1, which suggests moderate interaction of nimustine with DNA. The spectroscopic results are further used to calculate the binding free energy of the complex using the relation ΔG = ?RT ln (K a ). This accounts for a value of ?4.79 kcal/mol. It corroborates well with the docking outcomes. The results of present study may help in designing and synthesis of new chloroethyl nitrosourea derivatives with improved efficacy and specificity for the target molecules.  相似文献   

16.
This paper reports the anomalous behavior of unloaded quality factor (Q u ) of high T c superconducting (HTSC) microstrip resonator in weak dc magnetic field (Bdc). The Q u behavior increases with the elevated applied Bdc, but beyond the certain Bdc value, decreases linearly with Bdc. We speculate that this behavior may be caused by edge effect. The behavior is modeled both by the coupled-grain model accounting for a distribution of the grain dimension and Coffey-Clem model.  相似文献   

17.
The physical limits are studied theoretically for a mass of fullerenes which may be used to produce a stable crystal, i.e., fullerite. The dependence of the parameters of interfullerene interaction on the mass of fullerene C nc is used to study the evolution of the properties of fullerite as a result of variation of the number of carbon atoms nc in fullerene C nc . The dependences of the energy of activation process and surface energy are calculated for different values of temperature and pressure in the 15 ≤ nc ≤ 147 range. It is demonstrated that fullerite becomes unstable at nc < 20, because small-sized light fullerenes cannot be localized due to weak Van der Waals forces. At the same time, fullerites with nc ≥ 110 exhibit abnormally low values of surface energy; this must bring about the fragmentation of nanoclusters of hollow spherical C nc molecules of such a large size. Four empirical equations are used to estimate the dependence of the melting temperature of fullerite on nc. It is demonstrated that the melting temperature in the case of fullerites from small or large fullerenes is lower than that in the case of fullerites at 50 < nc < 90. It is inferred that the 30 < nc < 100 range is optimal for the formation of stable fullerite.  相似文献   

18.
Nanocrystalline Y1 ? x ? y Gd x Eu y PO4 phosphors have been prepared via precipitation from aqueous solutions. From their luminescence and excitation spectra, the intensity ratio I 615/I 594 of the Eu3+ luminescence bands corresponding to electric dipole and magnetic dipole transitions has been determined as a function of Gd3+ content. The critical concentration and effective energy transfer radius in Y1 ? x ? y Gd x Eu y PO4 have been evaluated. Excitation of Gd3+8 S J ?6 D J and 8 S J ?6 J J transitions to Eu3+ luminescence excitation levels in Y0.99 ? x Gd x Eu0.01PO4 involves efficient energy transfer. Under 250-nm excitation, the Eu3+ luminescence yield in Y0.99 ? x Gd x Eu0.01PO4 is a factor of 2.5–3 higher than that in Y0.99Eu0.01PO4.  相似文献   

19.
The effect of Ag addition on weak link behaviour of a Bi-2223 (Bi1.7Pb0.3Sr2Ca2Cu3O10) polycrystalline sample has been investigated in terms of AC susceptibility, critical current density (J c), electrical resistivity ρ(T)H and upper critical field (H c2). A series of phase pure Bi-2223-Ag x (x = 0.0–0.3) samples are prepared by the solid-state synthesis route. The phase purity, crystal structures and surface morphology are being studied using the X-ray diffraction and scanning electron microscopy (SEM) technique, respectively. The effect of Ag addition on inter- and intragranular coupling has been investigated by means of AC susceptibility and magneto-transport ρ(T)H measurements, and the results are compared with the pure Bi-2223 sample. Enhancement in granular coupling between the grains of the 20 wt% Ag-added Bi-2223 sample has been witnessed. Critical current density (J c) has been estimated using the AC susceptibility technique, and the results are interpreted in terms of inter- and intragranular coupling of the investigated samples. The high field magneto-transport technique has been used to estimate the upper critical field (H c2) and thermally activation flux flow (TAFF) activation energy. The ensuing results revealed that H c2 increases for the 20 wt% Ag-added sample along with enhancement in grain alignment and intergrain connectivity.  相似文献   

20.
We constructed theoretically one-dimensional photonic crystal (1DPC) by using a semiconductor metamaterial in the near-infrared range(NIR) which is composed of Al-doped Z n O(A Z O) and Z n O. The construction of this photonic crystal (PC) is based on a high-temperature superconductor material with the semiconductor metamaterial as constituent layers for this PC. The electromagnetic interactions with this periodic structure are investigated using the transfer matrix method (TMM) in the NIR range. The investigation shows that the reflectance spectra are depending on some parameters of the periodic structure such as the thicknesses of the constituent layers, temperature, and the angle of incidence.  相似文献   

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