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A new power and refrigeration cycle is examined in the present study. The system proposed is a combination of organic Rankine cycle (ORC) and an ejector refrigeration cycle (ERC). An ERC is introduced into the ORC to recover heat from partial expansion of the ORC fluid. The heat recovery is enhanced with the incorporation of recuperator, evaporator and superheater as heat exchangers. Among the various working fluids opted for, R245fa and R236ea have been considered in the present work. The properties of the combined cycle state points are evaluated through Engineering Equation Solver (EES) software. The impact of decision variables (such as hot source temperature, turbine expansion ratio, extraction ratio, and separator temperature) on performance parameters (such as exergy destruction, energy efficiency of power generation, exergy efficiency of power generation, energy efficiency of combined system, exergy efficiency of combined system, COP, and cooling power ratio) is examined and reported. The series heater configuration in ORC has improved system performance by recovering waste heat more effectively. At the same parametric conditions, the energy and exergy performances of R245fa are higher than those of R236ea. [ABSTRACT FROM AUTHOR]

In this study, in order to simplify the extraction process of taxifolin, cut costs and energy sources, improve extraction efficiency, and promote comprehensive application of taxifolin. Taxifolin was extracted from the trunk of Larix gemlini by ultra-high pressure assisted micellar green solvent extraction technology, using Larix gemlini of Heilongjiang Province as raw material. Based on the total content of taxifolin in different parts of larch root and trunk, tea saponin was selected as the most appropriate surfactant from candidate surfactants. The extraction process was optimized by response surface experiment, investigating effects of solid-liquid ratio, extraction pressure, extraction times and micellar concentration on the extraction rate of taxifolin. Results showed that, the optimal extraction process conditions were selected as follows: The tea saponin concentration was 8%, the solid-liquid ratio was 1:11.5, the extraction pressure was 157 MPa, the extraction times were 3 times, the holding time was 5 min. The experiment was repeated for 3 times under the optimum condition, and the actual extraction rate of taxifolin was 84.35%±1.2%, which was basically consistent with the predicted value of 84.98%. Compared with different extraction processes such as microwave extraction, ultrasonic extraction and reflux extraction, the energy consumption and CO2 emission per unit of raw material of ultra-high pressure assisted micelle extraction were the lowest, which was 1.64×10−4 kW·h·g−1 and 1.29×10−4 kg/g respectively. To summarize, the extraction of taxifolin from larch by ultra-high pressure assisted micellar green solvent extraction technology could be used widely which was environmentally friendly, simple, stable, reasonable and reliable.

[Display omitted] • The suitable extraction ratio for commercialized compost is 1:30. • Dry samples could be more effectively for maturity evaluation. • The extraction ratio of dry samples should be at least 1:30 but not exceed 1:50. • Carbon and nitrogen transformations were the decisive factors influencing the GI. • The concentration thresholds of DN, DOC, NH 4 + were 164 mg/L, 257 mg/L, 73 mg/L. The phytotoxicity of the compost aqueous extracts determines the maturity. To improve the accuracy of compost maturity evaluation using the seed germination index (GI) method, different extraction methods (different moisture content and extraction ratio) were designed to obtain samples with various phytotoxic level. This study analyzed the effects of different extraction condition of compost samples on GI, and established the relationship between phytotoxicity and GI. The results showed that the moisture content and extraction ratio of the compost significantly affected the GI. The extraction ratio for the compost with 60–70 % moisture content was 1:10 (ratio of compost mass to extract volume). However, commercial compost, which must have a moisture content of 30–45 %, had an extraction ratio of 1:30 (w:v). More importantly, compost extraction based on dry weight, with a moisture content of 10–15 %, more effectively reflected the phytotoxicity variations during composting. In such cases, the extraction ratio should be at least 1:30 (w:v) but not exceed 1:50 (w:v). The relationship between phytotoxicity and GI showed that dissolved organic carbon and dissolved nitrogen were the most important factors influencing GI, followed by NH 4 +, electrical conductivity, K, volatile fatty acids, Zn, and Cu. For composts with a GI greater than 70 %, the dissolved organic carbon, dissolved nitrogen, and NH 4 + concentrations were below 257, 164, and 73 mg/L, respectively. These findings provide an optimized standard method for compost maturity evaluation using GI and a concentration threshold of key phytotoxicity is proposed to achieve accurate control of compost maturity. [ABSTRACT FROM AUTHOR]

The paraffin–naphthenic fractions (with boiling points below 310°C) prepared from three high-viscosity naphthenic crude oils, classified as types B1 and B2 (according to Petrov's classification), were subjected to thiocarbamide complexation. The molecular composition of polycyclic hydrocarbon biomarkers and C11–C13 adamantanes in the oil samples suggested a predominantly marine genotype of the precursor organic matter (OM). The molecular composition also suggested source rocks of a clayey type. Nonetheless, the biomarkers detected in one sample indicated some contribution of terrigenous components to the precursor OM. All the oils were generated under the conditions of the main oil generation zone and, presumably, underwent microbial transformations in the deposits. The compositions of C10–C14 adamantanes in the initial paraffin–naphthenic fraction, in the thiocarbamide adduct, and in the filtrate that remained after the adduction were comparatively characterized for each oil sample. The test conditions allowed us to have adamantane more than 100-fold concentrated (in the adduct), to quantify it in the oils, and to evaluate the concentrations of C11–C14 alkyladamantanes in the oils using adamantane as an internal standard. C10–C14 adamantanes exhibited selective adduction ability, with the extraction ratios of individual components being different. Taking into account these extraction ratios, the component concentrations were evaluated on crude oil basis: 2.7 to 7.6×10–3 wt % for adamantane and 87 to 267×10–3 wt % for total C10–C14 adamantanes. The identification of adamantanes in the initial paraffin–naphthenic fractions, adducts, and filtrates revealed the presence of some other tricyclanes (probable precursors of alkyladamantanes) as well as decaline homologues. Like adamantanes, these compounds exhibited selective ability to complex with thiocarbamide. [ABSTRACT FROM AUTHOR]

The key fragment element samarium (Sm) has a large neutron absorption cross section, which can hinder the absorption of neutrons by uranium and negatively affect the nuclear reaction. In order to realize the nuclear fuel cycle, the extraction of Sm was studied on the basis of electrolytic refining after the dry process. The electrochemical properties of SmCl3 and SnCl2 in LiCl-KCl molten system were systematically investigated by cyclic voltammetry (CV), square wave voltammetry (SWV), and open circuit potential (OCP). The diffusion coefficients of the Sn(II) and Sm(III) electrode processes were calculated to be 3.55–5.93 × 10−5 and 2.33–3.97 × 10−5 cm2 s−1, respectively. The co-reduction of Sm(III) and Sn(II) ions was studied. Sm was recycled by constant current electrolysis on the liquid Sn electrode, and the average extraction rate was about 94.23%. The samples were characterized and analyzed by X-ray diffraction analysis (XRD) and scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy (SEM), and the results showed that Sm extraction from liquid tin is feasible. [ABSTRACT FROM AUTHOR]

In order to improve the utilization of spent fuel, electrolysis is used to recover fissile elements from nuclear waste samarium. The electrochemical behaviors of Sm(III) and Pb(II) were examined by CV, SWV, and OCP techniques in LiCl–KCl molten salts at 773 K. The redox mechanism of Sm(III) ions on the liquid Pb thin film electrode was analyzed. The results demonstrate that Sm(III) electro-reduction at the inert W electrode only occurred in a soluble–soluble electrochemical transition Sm(III)/Sm(II). Additionally, the kinetic parameters of samarium and lead ions were computed. The activation energies of diffusion for Sm(III) and Pb(II) were 32.92 kJ mol−1 and 35.21 kJ mol−1, respectively. SmPb3 and Sm2Pb intermetallic compounds were derived using constant potential electrolysis and constant current electrolysis at the Pb electrode in a molten salt system. The cathodic deposition output was characterized by XRD and SEM–EDS. The ICP-AES results showed that the average extraction ratio of Sm on the Pb electrode was about 94.23%. [ABSTRACT FROM AUTHOR]

Neurotoxin β-N-methylamino-L-alanine (BMAA) is hypothesized as an important pathogenic factor for neurodegenerative diseases such as amyotrophic lateral sclerosis/parkinsonism-dementia complex (ALS-PDC). Comparative study on the accuracy of BMAA analyzed by the regular LC-MS/MS methods is still limited for different biological matrices. In this study, a free-BMAA sample of cyanobacterium and BMAA-containing positive samples of diatom, mussel, scallop, and oyster were extracted with varied extraction ratios (ER) ranging from 1:20 to 1:2000. These extracts were then purified by MCX cartridges. After SPE purification, these different biological samples were analyzed by two common LC-MS/MS analysis methods, a direct analysis without derivatization by a hydrophilic interaction liquid chromatography (HILIC)-MS/MS and pre-column 6-aminoquinolyl-N-hydroxysuccinimidyl carbamate (AQC) derivatization combined with a C18 column. The results suggested that the recoveries of BMAA spiked in the cyanobacterial sample were close to 100% in the total soluble form extracts with the ER of 1:100 (g/mL) and the precipitated bound form extracts with the ER of 1:500. The recommended ER for the precipitated bound form of BMAA in diatoms and the total soluble form of BMAA in mollusks are 1:500 and 1:50, respectively. The quantitative results determined by the AQC derivatization method were lower than those determined by the direct analysis of the HILIC method in diatom and mollusk samples. The results of the HILIC method without the derivatization process were closer to the true value of BMAA in cyanobacteria. This work contributes to the performance of the solid-phase extraction (SPE) purification protocol and the accuracy of BMAA analysis by LC-MS/MS in diverse biological samples. [ABSTRACT FROM AUTHOR]

Variations in rock fragmentation are very likely to occur in a sublevel-caving operation. This study conducted a comprehensive test in an iron ore mine to monitor rock fragmentation. The results show a clear trend in fragmentation variations from start to end of production from a ring. These variations suggest an increase in coarse and oversized fragments with increasing material extraction from the rings that can be linked to increased overburden and drill hole deviations in the upper part of the rings. These problems can be addressed by shortening the drill hole length or directional drilling but need further investigations. [ABSTRACT FROM AUTHOR]

Neurotoxin β-N-methylamino-L-alanine (BMAA) is hypothesized as an important pathogenic factor for neurodegenerative diseases such as amyotrophic lateral sclerosis/parkinsonism-dementia complex (ALS-PDC). Comparative study on the accuracy of BMAA analyzed by the regular LC-MS/MS methods is still limited for different biological matrices. In this study, a free-BMAA sample of cyanobacterium and BMAA-containing positive samples of diatom, mussel, scallop, and oyster were extracted with varied extraction ratios (ER) ranging from 1:20 to 1:2000. These extracts were then purified by MCX cartridges. After SPE purification, these different biological samples were analyzed by two common LC-MS/MS analysis methods, a direct analysis without derivatization by a hydrophilic interaction liquid chromatography (HILIC)-MS/MS and pre-column 6-aminoquinolyl-N-hydroxysuccinimidyl carbamate (AQC) derivatization combined with a C18 column. The results suggested that the recoveries of BMAA spiked in the cyanobacterial sample were close to 100% in the total soluble form extracts with the ER of 1:100 (g/mL) and the precipitated bound form extracts with the ER of 1:500. The recommended ER for the precipitated bound form of BMAA in diatoms and the total soluble form of BMAA in mollusks are 1:500 and 1:50, respectively. The quantitative results determined by the AQC derivatization method were lower than those determined by the direct analysis of the HILIC method in diatom and mollusk samples. The results of the HILIC method without the derivatization process were closer to the true value of BMAA in cyanobacteria. This work contributes to the performance of the solid-phase extraction (SPE) purification protocol and the accuracy of BMAA analysis by LC-MS/MS in diverse biological samples.

Copyright of Journal of China University of Petroleum is the property of China University of Petroleum and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

An improved method of (NH4)2SO4 roasting followed by water leaching to utilize zinc oxidized ores was studied. The operating parameters were obtained by investigating the effects of the molar ratio of (NH4)2SO4 to zinc, roasting temperature, and holding time on zinc extraction. The roasting process followed the chemical reaction control mechanism with the apparent activation energy value of 41.74 kJ·mol−1. The transformation of mineral phases in roasting was identified by X-ray diffraction analysis combined with thermogravimetry-differential thermal analysis curves. The water leaching conditions, including the leaching temperature, leaching time, stirring velocity, and liquid-to-solid ratio, were discussed, and the leaching kinetics was studied. The reaction rate was obtained under outer diffusion without product layer control; the values of the apparent activation energy for two stages were 4.12 and 8.19 kJ·mol−1. The maximum zinc extraction ratio reached 96% while the efficiency of iron extraction was approximately 32% under appropriate conditions. This work offers an effective method for the comprehensive use of zinc oxidized ores. [ABSTRACT FROM AUTHOR]

Copyright of Food Research & Development is the property of Food Research & Development Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

OBJECTIVE: To optimize the water extraction by central composite design/response surface methodology. METHODS: Central composite design/response surface methodology was adopted. Independent variables were reflux time and solvent fold, the dependent variable was extraction ratio. Level of independent variables were regressed by multiple linear and fitted by binomial. Response surface methodology was used to optimize extraction process. Prediction was carried out by comparing observed and predicted values. RESULTS: Optimal extraction technology was: extracted 2 times by 11.8 times the amount of water with 2.4 h each time. The deviation between observed and predicted values was 3.34%. The regression coefficients of binomial fitting complex model r=0.917 0. CONCLUSIONS: Central composite design/response surface methodology is a simple method with high precision and good predictability. [ABSTRACT FROM AUTHOR]

The pharmacokinetics of linezolid clearance (CL LZD ) during continuous hemodiafiltration (CHDF) has not been comprehensively analyzed. Here, we examined CL LZD by CHDF in a patient with septic shock and disseminated intravascular coagulation due to methicillin-resistant Staphylococcus aureus . The extraction ratio of LZD by CHDF was 22.6%, and the protein-binding rate was 17.9% ± 7.7%. In addition, it was determined that the calculated total body clearance of LZD was 30.2 mL/min, plasma elimination half-life was 8.66 h, and the CL LZD by the dialyzer used for CHDF was 23.0 mL/min. From the obtained pharmacokinetics, the CL LZD of patients continuing CHDF was estimated to be approximately half of the reported CL LZD for healthy subjects. In addition, the LZD concentration of the sepsis patient who underwent CHDF remained higher than the minimum inhibitory concentration and was similar to the LZD concentrations reported in normal renal function patients. Although further studies are warranted, when LZD is administered to patients treated with CHDF, the present findings suggest that dose regulation is not required. [ABSTRACT FROM AUTHOR]

This paper examines the effect of different geological and mining factors on roof stability in underground coal mines by combining field observations, laboratory testing, and numerical modeling. An underground coal mine in western Pennsylvania is selected as a case study mine to investigate the underlying causes of roof falls in this mine. Three-dimensional distinct element analyses were performed to evaluate the effect of different parameters, such as the variation of immediate roof rock mass strength properties, variation of discontinuity mechanical properties, orientations and magnitudes of the horizontal in-situ stresses, and the size of pillars and excavations on stability of the immediate roof. The research conducted in this paper showed that the bedding planes play an important role on the geo-mechanical behavior of roofs in underground excavations. Therefore, an appropriate numerical modeling technique which incorporates the effect of discontinuities should be employed to simulate the realistic behavior of the discontinuous rock masses such as the layered materials in roof strata of the underground coal mines. The three-dimensional distinct element method used in this research showed the capability of this technique in capturing the important geo-mechanical behavior around underground excavations. [ABSTRACT FROM AUTHOR]

Data on the mineral, phase, and elemental compositions of a zinc clinker as zinc production waste have been given and the possibility of hydrometallurgical processing using HCl solutions has been investigated. The kinetics of the clinker interacting with HCl solutions of 50-200 g/L in the temperature range of 50-90°C has been studied. The high efficiency of the muriatic acid for the decomposition of both the magnetic fraction and the general clinker sample with the 95-99% extraction of iron and nonferrous metal in solution and the more than 3.5-fold reduction in the clinker mass have been determined. The possibility of processing the filtrate extraction from the decomposition of the clinker by HCl using 100% tributyl phosphate as an extracting agent while obtaining oxide product containing >97% Fe suitable for producing iron-oxide pigment has been shown. [ABSTRACT FROM AUTHOR]