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In this study, an explicit dynamic constitutive model was established for ultra high toughness cementitious composites (UHTCCs). The model, based on the Holmquist–Johnson–Cook (HJC) model, includes tensile and compressive damage evolution, hydrostatic pressure, strain rate, and the Lode angle effect. The proposed model was embedded in LS-DYNA software and then comprehensive tests were carried on a hexahedral brick element formulation under uniaxial, biaxial, and triaxial stress states to verify its rationality through comparisons with results determined by the HJC and Karagozian & Case (K&C) models. Finally, the proposed model was used to simulate the damage caused to UHTCC targets subjected to blast by embedded explosive and projectile penetration, and predictions were compared with corresponding experimental results. The results of the numerical simulations showed that our proposed model was more accurate than the HJC model in predicting the size of the crater, penetration depth, and the distribution of cracks inside the target following the blast or high-speed impact loading.

The synergistic extraction of phenol from aqueous solution with diisopropyl ether (DIPE) and n-pentanol was studied at 298.15 K under 101.3 kPa. The liquid–liquid equilibrium (LLE) data of the quat...

Needle coke wastewater is rich in phenol and poses a great challenge to industrial implementation of phenol extraction because of the low extraction capacity of current industrial extractants. In t...

Global warming is altering both phytoplankton-experienced temperature and light-exposure duration through shifting their niches from low to high latitudes. We explored the growth, physiology, and compositions of a smaller Thalassiosira pseudonana and a larger Thalassiosira punctigera, temperate marine centric diatoms, in responses to a matrix of temperatures (12, 15, 18, and 21 °C) and photoperiods (light:dark cycles of 4:20, 8:16, 16:8, and 24:0). Both T. pseudonana and T. punctigera grew faster under medium temperature and longer photoperiod, under the expected optimal instantaneous light intensity. The biovolume-based pigments content of T. pseudonana responded largely to temperature, while that of T. punctigera responded more to photoperiod duration than to temperature. In T. pseudonana, shortest photoperiod enhanced cellular protein content and alleviated their temperature dependency. Continuous growth light reduced the photosynthetic capacity of T. pseudonana at the lowest temperature and reduced that of T. punctigera across temperatures. Moreover, we found the increasing temperature linearly increased the dark respiration rate (Rd) and molar ratio of carbon to nitrogen (C:N) of T. pseudonana but decreased that of T. punctigera, with the scattered effects of photoperiod. Our results demonstrated that responses of diatoms Thalassiosira across photoperiods and temperatures vary with species and possibly with cell size, suggesting that the poleward shift of the niches of phytoplankton in nature might cause a change in community structure.

The synergistic effect for a solvent mixture of diisopropyl ether and n-Pentanol to extract hydroquinone from aqueous solution was investigated. Liquid–liquid equilibrium data of the quaternary (n-Pentanol + diisopropyl ether + water + hydroquinone) system were measured at T = 298.15 K and P = 101.3 kPa, using various compositions of solvent mixture. It can be seen from the slope of the tie lines that with the increase of distribution coefficients of hydroquinone, the size of the immiscible solution region decreased slightly. The extraction efficiency was evaluated by calculating the separation factor and distribution coefficient. Using the universal quasichemical (UNIQUAC) and nonrandom two-liquid (NRTL) models to correlate with experimental data, the corresponding binary interaction parameters were obtained. The RMSD values of UNIQUAC and NRTL models showed that the calculated results were in good agreement with the liquid–liquid equilibrium data.

Due to the limitation of the existing solvents, the phenols recovery process cannot control phenols concentration to less than 300 mg/L. Therefore, this study presented a synergistic phenols extraction process by using optimal design solvent mixture. The solvent mixture was proposed with the volume ratio of methyl isobutyl ketone (MIBK) to n-pentanol 6:4. The synergistic extraction process was simulated to acquire the parameters with treatment 130 t/h coal gasification wastewater. The removal efficiencies of phenols and treatment costs for the synergistic extraction process had been addressed. The removal efficiency of total phenols can reach to 97.0% after two-stage extraction, and the concentration of total phenols can be decreased from 6273 mg/L to 190 mg/L. Compared with single solvent MIBK, the reduction of phenols emissions is 47.2% by proposed solvent mixture. The operation cost and income of crude phenols showed that synergistic extraction process realized profit about 3.35 CNY/t. Given the removal efficiencies and treatment costs, the solvent mixture (60% MIBK, 40% n-pentanol) is very promising for phenols removal.

This study investigated the dynamic response of one-way square ultra-high toughness cementitious composite (UHTCC) slabs under close-in blast loadings. Six UHTCC slabs and two ordinary concrete slabs with dimensions of 600 mm × 600 mm×60 mm were subjected to blast loadings at scaled distances of 0.043 m/kg1/3, 0.085 m/kg1/3, 0.136 m/kg1/3, 0.271 m/kg1/3, 0.407 m/kg1/3 and 0.356 m/kg1/3 by varying both charge and distance to the slab. The results indicate the UHTCC displayed better blast resistance performance than the ordinary concrete. Under 200 g TNT blast loadings, the UHTCC slabs presented breaching damage and several cracks and could still bear the load, while the ordinary concrete slabs were broken severely and could not bear load anymore. The existing empirical formulae, including McVays’ and UFC 3-340-02, were employed and discussed to predict the failure modes of UHTCC slabs under blast loading. And a formula was proposed to estimate the residual load-carrying capacity of UHTCC slabs and was fitted well with the experimental data. Furthermore, Finite Element (FE) models were developed to study the dynamic response of slabs in LS-DYNA. The findings of this study indicate that the UHTCC has good potential for the constitution of protective structures.

Reinforced concrete (RC) structures under blast loading can occur severe structural damage, including cratering, spalling, and breaching. And these damages could cause danger to the personnel and equipment. In this study, ultra-high toughness cementitious composite (UHTCC) with significant strain-hardening behavior (ultimate tensile strain >3%) was utilized to improve the blast resistance of construction structure. The UHTCC square slabs with a side length of 2000 mm were tested under contact explosions. The cratering and spalling damage of slabs were investigated. A total of six slabs (three RC slabs and three UHTCC slabs) under three different weight of TNT charge (2 kg, 4 kg, and 5 kg) were tested. The results showed the UHTCC slabs presented excellent blast resistance compared with RC slabs. The existing empirical predictions were employed to explore the damage mode of UHTCC slabs compared with the experimental results. The suitability and accuracy of the predictions were discussed. The structured and unstructured discretizations with different mesh size were used in the finite element (FE) model. The simulation results from the unstructured discretizations show better agreement with the experimental results than that from the structured discretizations. The effect of mesh size on the damaged area, damaged depth, deflection-time curves of the slab and the eroded volume fraction were compared and discussed. In addition, the sensitivity analysis of input parameters in the numerical model were conducted. the maximum failure strain, the compressive strength and the mass density of UHTCC were employed as the input parameters to investigate and discuss their effects on the value of output parameters, which include the damaged area, damaged depth and maximum deflection of UHTCC slab.

Liquid–liquid equilibrium (LLE) data for the ternary systems (methyl isobutyl ketone + quinoline or isoquinoline + water) were measured at T = 298.15, 318.15, and 338.15 K and atmospheric pressure. Distribution coefficients and separation factors were calculated to evaluate extraction efficiency. The Hand, Bachman, and Othmer–Tobias equations were applied to verify the reliability of the experimental tie-line data. The NRTL and UNIQUAC models were used to correlate all of the experimental values at different temperatures simultaneously. The binary interaction parameters of these two models were obtained. The root-mean-square deviation between the experimental and calculated data indicates that the NRTL model presents a better prediction than the UNIQUAC model. The effect of temperature on the extraction performance of methyl isobutyl ketone was investigated. The extraction process of quinoline or isoquinoline by methyl isobutyl ketone is exothermic. The increase of temperature is not a benefit to extract ...

This paper presents a comparative study on the perforation resistance of thick panels made of the reactive powder concrete (RPC) and the ultra high toughness cementitious composites (UHTCC). Damage patterns of the target were measured, including the diameter and depth of the cratering and scabbing on the front and rear surfaces. Residual velocities of the projectiles were determined by a high speed camera. The test results showed 46 MPa UHTCC has superior resistance to the tensile damage induced cratering and scabbing while its penetration resistance is comparable to NC with a lower compressive strength (30 MPa). The 123 MPa RPC exhibits much higher penetration resistance than UHTCC and NC, and has improved performance over NC in resisting tensile damage. Besides, based on the framework of the Forrestal formula, a unified semi-analytical model is proposed which can predict the penetration and perforation ballistic parameters of thick concrete panel under projectile impact. Compared to the experimental observations, the proposed model predicts the residual velocity and penetration depth of this test with better results than existing models. Finally, the new model is applied to the available perforation tests of thick concrete panels, and its error used for relatively thin concrete panel is analyzed.

This paper studies the dynamic properties, damage characteristics and failure laws of reactive powder concrete (RPC) subjected to blasts by embedded explosive. The experimental program includes tests of blast resistance carried on RPC targets and high-strength concrete (HSC) targets as control specimens by varying the depth of explosive. Experimental results show that RPC has a superior blast resistance compared to HSC characterized by smaller crater and targets integrity. In the numerical analysis, a modified constitutive model that reflects the basic mechanical properties of RPC, i.e., high strength, tensile ductility and insensitive to strain rate, was adopted by improving the strength surface, damage equation and strain rate effect based on the Kong-Fang model. The modified model was embedded in LS-DYNA software to simulate the failure mode of the RPC targets at different embedding depths of explosives and compared with the predicted results obtained from the Kong-Fang model. The simulation results predicted by the modified Kong-Fang model are suitable for the experimental results.

Dengue virus (DENV) is still a major threat to human health in most tropical and subtropical countries and regions. In the present study, a multi-epitope DNA vaccine that encodes 15 immunogenic and conserved HLA-A*0201-, HLA-A*1101-, HLA-A*2402-restricted CTL epitopes from DENV serotype 1 (DENV-1) was constructed based on the eukaryotic expressing plasmid pcDNATM 3.1/myc-His(-) A. Immunization of HLA-A*0201, HLA-A*1101 and HLA-A*2402 transgenic mice with the recombinant plasmid pcDNATM 3.1/myc-His(-) A-DENV-1-Meg resulted in significantly greater IFN-γ-secreting T-cell responses against most (14/15) CTL epitopes than occurred in mice immunized with the empty plasmid pcDNATM 3.1/myc-His(-) A. Additionally, the epitope-specific T cells directed to some epitopes secreted not only IFN-γ but also IL-6 and/or TNF-α. Finally, the induced epitope-specific T cells also efficiently lysed epitope-pulsed splenocytes and DENV-1-infected splenic monocytes. The present study confirms the immunogenicity of multi-epitope DENV vaccine, suggesting that it may contribute to the development of a universal DENV vaccine.

This study investigates the combined effect of the strain rate and temperature on the compressive properties of hybrid fiber ultra high toughness cementitious composites (UHTCCs) using a Split Hopkinson pressure bar. Specimens were first heated to different exposure temperatures, e.g. ambient temperature, 200, 400, 500, 600 and 800 °C, and subsequently, cooled to ambient temperature. Thereafter, the specimens were tested at four different strain rates. The test results show that the dynamic compressive strength of the UHTCC is enhanced at a temperature of 200 °C, and subsequently, decreases with the increase in exposure temperature. The strain rate sensitivity of UHTCC is largely enhanced with the increase in exposure temperature. The possible mechanism of this phenomenon was discussed based on the high-speed photography of the crack propagation process on the surface of the specimens and microscopic observation of fibers condition on their fracture surfaces. Moreover, an empirical relationship is established to express the dynamic strength enhancement of fire-damaged UHTCC as a function of strain rate.

With low oil prices, the existing coal-to-olefin enterprises are forced to improve profitability by reducing energy consumption. This paper studies the comprehensive energy analysis and integration of coal-based MTO process. Process simulation is established first and is validated by comparing with the industrial data. Energy analysis of the MTO process was then conducted, calculating relevant information of each heat exchange stream. The heat exchanger network synthesis was proposed by using gradual optimization integration strategy based on the T-H diagram. It was found that the hot energy of purified water and steam condensate could be fully utilized. The cold energy of ethylene tower could replace partial −24 °C refrigerant. It was also found that there is the possibility of multi-stage heat transfer in this process. The maximum energy recovery is achieved under the principle of energy cascade utilization and stepwise matching. The result showed that the new design decreases the utility duty and the required exchanger area by 4.76% and 8.63% compared with the industrial process. The capital cost, operation cost and total annual cost of total site are 8.17, 14.64 and 17.27 million $, which are 8.29%, 2.78% and 3.66% less than the industrial design.

MPT63 protein is found only in Mycobacterium tuberculosis complex, including M. tuberculosis and M. bovis. Detection of MPT63-specific IFN-γ-secreting T cells could be useful for the diagnosis of tuberculosis (TB) diseases. In the present study, the HLA-A*0201 restriction of ten predicted MPT63-derived CD8(+) T-cell epitopes was assessed on the basis of T2 cell line and HLA-A*0201 transgenic mice. The diagnostic potential of immunogenic peptides in active pulmonary TB patients was evaluated using an IFN-γ enzyme-linked immunospot assay. It was found that five peptides bound to HLA-A*0201 with high affinity, whereas the remaining peptides exhibited low affinity for HLA-A*0201. Five immunogenic peptides (MPT6318-26 , MPT6329-37 , MPT6320-28 , MPT635-14 and MPT6310-19 ) elicited large numbers of cytotoxic IFN-γ-secreting T cells in HLA-A*0201 transgenic mice. Each of the five immunogenic peptides was recognized by peripheral blood mononuclear cells from 45% to 73% of 40 HLA-A*0201 positive TB patients. The total diagnostic sensitivity of the five immunogenic peptides was higher than that of a T-SPOT.TB assay (based on ESAT-6 and CFP-10) (93% versus 90%). It is noticeable that the diagnostic sensitivity of the combination of five immunogenic peptides and T-SPOT.TB assay reached 100%. These MPT63-derived HLA-A*0201-restricted CD8(+) T-cell epitopes would likely contribute to the immunological diagnosis of M. tuberculosis infection and may provide the components for designing an effective TB vaccine.

Geographical maldistribution of coal and water resource has led to huge water consumption, posing great challenges to the development of coal chemical industries in China. In this study, based on the obtained unit product data of water withdrawal, consumption, and wastewater effluent capacity, the wastewater quantitative information about water quality and relevant energy and reagents consumption for several coal chemical industries were analyzed. Then, the life cycle costs of different types of coal chemical wastewater were analyzed when achieving ICIWD (1st category integrated wastewater discharge) and ZLD (zero liquid discharge) standards. According to the results, the life cycle cost of ICIWD was average 0.94 US$/t water less than that of the wastewater meeting ZLD, because the life cycle boundaries focused on coal chemical industries. Given surface water treatment cost and environment damages value, ICIWD's total cost was 1.07 US$/t water higher than ZLD's. Besides, the consumed water of planning advanced coal chemical projects of 2018 took up 2.8% of total industrial water. Such proportion could even reach over 30% in north and northwest regions. It is suggested that ZLD water policies and water resources appraisal should be introduced to improve and strengthen the rational layout of coal chemical projects.

PPE68 is a Mycobacterium tuberculosis-specific protein which is absent from the vaccine strains of BCG. A panel of 14 PPE68-derived peptides predicted to bind to HLA-A*0201 was synthesized. The HLA-A*0201 restriction of these peptides was determined in T2 cell line and HLA-A*0201 transgenic mice. The specificity of peptides was assessed in pulmonary tuberculosis (TB) patients using IFN-γ enzyme-linked immunospot (ELISPOT) assay, and immunodominant peptides were further used to evaluate their diagnostic potential in HLA-A*0201-positive pulmonary TB patients. 13 out of 14 peptides were identified as high-affinity binders. Of these peptides, 12 peptides induced significant IFN-γ-secreting T cell response in transgenic mice and 9 peptides were efficiently recognized by peripheral blood mononuclear cells of 10 HLA-A*0201-positive TB patients. Four immunodominant HLA-A*0201-restricted epitopes (PPE68126-134, PPE68133-141, PPE68140-148, and PPE68148-156) were recognized by the most of 80 HLA-A*0201-positive TB patients (81, 86, 74, and 84 %, respectively). These epitopes may be used for a potential diagnosis of M. tuberculosis infection.

In this study, we set out to identify dengue virus serotype 2 (DENV-2)-specific HLA-A*2402-restricted epitopes and determine the characteristics of T cells generated to these epitopes. We screened the full-length amino-acid sequence of DENV-2 to find potential epitopes using the SYFPEITHI algorithm. Twelve putative HLA-A*2402-binding peptides conserved in hundreds of DENV-2 strains were synthesized, and the HLA restriction of peptides was tested in HLA-A*2402 transgenic mice. Nine peptides (NS4b(228-237), NS2a(73-81), E(298-306), M(141-149), NS4a(96-105), NS4b(159-168), NS5(475-484), NS1(162-171), and NS5(611-620)) induced high levels of peptide-specific IFN-γ-secreting cells in HLA-A*2402 transgenic mice. Apart from IFN-γ, NS4b(228-237-), NS2a(73-81-) and E(298-306)-specific CD8(+) cells produced TNF-α and IL-6 simultaneously, whereas M(141-149-) and NS5(475-484-) CD8(+) cells produced only IL-6. Moreover, splenic mononuclear cells (SMCs) efficiently recognized and killed peptide-pulsed splenocytes. Furthermore, each of nine peptides could be recognized by splenocytes from DENV-2-infected HLA-A*2402 transgenic mice. The SMCs from HLA-A*2402 transgenic mice immunized with nine immunogenic peptides efficiently killed DENV-2-infected splenic monocytes. The present identified epitopes have the potential to be new diagnostic tools for characterization of T-cell immunity in DENV infection and may serve as part of a universal epitope-based vaccine.

Dengue virus (DENV) is still a major threat to human health in most tropical and subtropical countries and regions. In the present study, a multi-epitope DNA vaccine that encodes 15 immunogenic and conserved HLA-A*0201-, HLA-A*1101-, HLA-A*2402-restricted CTL epitopes from DENV serotype 1 (DENV-1) was constructed based on the eukaryotic expressing plasmid pcDNA

MPT63 protein is found only in Mycobacterium tuberculosis complex, including M. tuberculosis and M. bovis. Detection of MPT63-specific IFN-γ-secreting T cells could be useful for the diagnosis of tuberculosis (TB) diseases. In the present study, the HLA-A*0201 restriction of ten predicted MPT63-derived CD8(+) T-cell epitopes was assessed on the basis of T2 cell line and HLA-A*0201 transgenic mice. The diagnostic potential of immunogenic peptides in active pulmonary TB patients was evaluated using an IFN-γ enzyme-linked immunospot assay. It was found that five peptides bound to HLA-A*0201 with high affinity, whereas the remaining peptides exhibited low affinity for HLA-A*0201. Five immunogenic peptides (MPT6318-26 , MPT6329-37 , MPT6320-28 , MPT635-14 and MPT6310-19 ) elicited large numbers of cytotoxic IFN-γ-secreting T cells in HLA-A*0201 transgenic mice. Each of the five immunogenic peptides was recognized by peripheral blood mononuclear cells from 45% to 73% of 40 HLA-A*0201 positive TB patients. The total diagnostic sensitivity of the five immunogenic peptides was higher than that of a T-SPOT.TB assay (based on ESAT-6 and CFP-10) (93% versus 90%). It is noticeable that the diagnostic sensitivity of the combination of five immunogenic peptides and T-SPOT.TB assay reached 100%. These MPT63-derived HLA-A*0201-restricted CD8(+) T-cell epitopes would likely contribute to the immunological diagnosis of M. tuberculosis infection and may provide the components for designing an effective TB vaccine.