Residual Solution Research Articles

Facile fabrication of ZIF‐8 embedded millimeter‐sized porous polyethersulfone beads for selective dye removal

ZIF‐8 particles show excellent selective adsorbing ability for methyl blue (MB). However, the main problem of ZIF‐8 particles as adsorbents is the difficulty of recovery from residual solution after use due to the nano‐sized dimension. In this study, ZIF‐8 particles were embedded into polyethersulfone (PES) polymer and a phase‐inversion method was used to synthesize millimeter‐sized beads. Such composite beads showed an excellent MB adsorption performance (50 ppm MB in 40 ml aqueous solution can be fully absorbed by 400 mg of ZIF‐8/PES within 1 h). Moreover, due to millimeter size and good floatability (hydrophobic nature of polymer), such ZIF‐8/PES beads are easy to handle and can be fully recovered from dye solution after adsorption without using complex processes such as centrifugation. Through this study, a facile method was offered to synthesize millimeter‐sized beads containing adsorbents, making the adsorption process less complicated and much easier to operate. POLYM. COMPOS., 39:3896–3902, 2018. © 2017 Society of Plastics Engineers

Thermal residual solutions of beams, plates and shells due to laminated object manufacturing with gradient cooling

Laminated object manufacturing (LOM) results in thermal residual stresses and deformations due to its material mismatch among layers and gradient cooling. The manufacturing and cooling processes in a laminated workpiece are decomposed into many turns. Through-thickness cooling gradients are considered in each layer forming turn. The thermal residual strains in each turn are deduced. The total thermal residual stresses are obtained by composing the strains in all turns. The workpieces with geometries of a beam, plate and shell are considered. For a beam or plate, the analytical solutions of the stresses and deformations in the axial and transverse directions are deduced separately and then synthesized to the total solutions. One-dimensional beams and two-dimensional plates have very similar solutions. For a symmetrical hollow cylinder or sphere, the analytical solutions of thermal residual stresses with through-thickness cooling gradients are also formulated. The numerical examples show that the assumption of synchronous cooling results in big errors and cooling gradients also induce thermal residual stresses and deformations. Four gradient cooling models are summarized according to various LOM manufacturing techniques and the thermal residual level is proportional to the cooling gradient. Processing sequence in functional gradient materials has a strong impact on thermal residual level.

Highly selective separation and recovery of Pd(II) from the automotive catalyst residue with the thiocarbamoyl substituted azothiacalix[4]arene derivative

ABSTRACTNew ligand, namely, 5, 11, 17, 23-tetrakis-((p-chlorophenyl) azo)-25,26,27,28-tetrakis ((dimethylthio carbamoyl)oxy) thiacalix[4]arene (CADTTCA), has been investigated for separation and recovery of Pd(II) through solvent extraction technique. Experimental parameters such as contact time, diluents, effect of H+ and Cl− concentration, and acid durability have been thoroughly investigated. The loading capacity toward Pd(II) was determined to be 113 mg/L using 0.25 mM CADTTCA. The extractant showed high selectivity and extractability for Pd(II) than the other metal ions present in automotive catalyst residue (ACR) solution containing platinum group (PGMs) metal ions (i.e., Pd(II), Pt(IV), Rh(II), La(III), Al(III) and Ce(III)). The recovery percentage of Pd(II) was 98% after five extraction-scrubbing-stripping cycles. The probable extraction mechanisms were established through the FT-IR spectral analysis.

Microbial Contamination of Eye Drops in out Patient in Iraq


 Acontaminated ophthalmic solutions represent a potential cause of avoidable ocular infection. This study aimed to determine the magnitude and pattern of microbial contamination of eye drops in out patient at the department of ophthalmology, at Baghdad national hospital, Iraq. Fifty four vials from the out patient clinic were obtained for microbial examination after an average use of 2 weeks. The dropper tip and the residual eye drop were examined for contamination. The specimens were cultured, the number of colonies counted, the organisms identified. Eight (15%) out of 54 analyzed vials were contaminated , most bacteria identified belonged to the normal commensal flora of the eye. Isolated contaminants were Staphylococcus auereus, Micrococcus , Neisseria catarrhalis, Gram negative Rods, Candida albicans, and Staph epidermidus.The dropper tip was more often contaminated (n=5) than the residual solution (n=2) and only one vial showed acontamination of both the drop and the tip (n=1) . Our data show acontamination rate of 15%, which is in the medium range of data puplished on the contamination of eye drops elsewhere (0.07% to 35.8%).
 Key words : Microbial Contamination, Eye Drops

3D seismic residual statics solutions derived from refraction interferometry

ABSTRACTWe apply interferometric theory to solve a three‐dimensional seismic residual statics problem to improve reflection imaging. The approach calculates the static solutions without picking the first arrivals from the shot or receiver gathers. The static correction accuracy can be significantly improved by utilising stacked virtual refraction gathers in the calculations. Shots and receivers may be placed at any position in a three‐dimensional seismic land survey. Therefore, it is difficult to determine stationary shots and receivers to form the virtual refraction traces that have identical arrival times, as in a two‐dimensional scenario. To overcome this problem, we use a three‐dimensional super‐virtual interferometry method for residual static calculations. The virtual refraction for a stationary shot/receiver pair is obtained via an integral along the receiver/shot lines, which does not require knowledge of the stationary locations. We pick the maximum energy times on the interferometric stacks and solve a set of linear equations to derive reliable residual static solutions. We further apply the approach to both synthetic and real data.

Effect of different extraction processes on the recovery of ghee residue proteins

Ghee residue (GR) is the by-product of ghee industry, possessing huge nutritional potential that still lacks in its valorization. This investigation was aimed to recover proteins from GR, by processing with different treatments such as boiling water (30 min), washing with 50% alcohol, isoelectric precipitation, boiling in sodium tri polyphosphate concentration (STPP) solution (1, 2, 3% strength, 30 min) and employing ultrafiltration membrane process. Extraction of proteins from the processed ghee residue (PGR) was observed to be of lower proteins purity. Commonly used acid precipitation method also failed to precipitate proteins from GR, but ultrafiltration resulted in efficient concentration of these proteins. Decrease in concentration of ghee residue and increase in dissolving time,significantly increased solubility of GR. Similarly, addition of sodium tri polyphosphate concentration (STPP) and dissolving time also significantly improved GR solubility. Ghee residue solution was concentrated up to 5.2 ultrafiltration (UF) folds, after that membrane flux approached to zero. Further, ultrafiltration of GR solution resulted in 97% recovery and 70% purity of GR proteins. Findings of this study could significantly increase the profit of organized dairy plants and significantly reduce the waste disposal problem. About 1,00,000 tonnes of proteins can be recovered annually from GR only; that can satisfy yearly protein requirement of about 45,66,000 healthy persons and might help the nation in combating severe problem of protein energy malnutrition.

Two-stage stochastic variational inequalities: an ERM-solution procedure

We propose a two-stage stochastic variational inequality model to deal with random variables in variational inequalities, and formulate this model as a two-stage stochastic programming with recourse by using an expected residual minimization solution procedure. The solvability, differentiability and convexity of the two-stage stochastic programming and the convergence of its sample average approximation are established. Examples of this model are given, including the optimality conditions for stochastic programs, a Walras equilibrium problem and Wardrop flow equilibrium. We also formulate stochastic traffic assignments on arcs flow as a two-stage stochastic variational inequality based on Wardrop flow equilibrium and present numerical results of the Douglas–Rachford splitting method for the corresponding two-stage stochastic programming with recourse.

High selectivity and extractability of palladium from chloride leach liquors of an automotive catalyst residue by azothiacalix[4]arene derivative

Pd(II) is a noble metal in the platinum group metals (PGMs) and has been used extensively in automobile catalysts. However, its resources are strictly limited; thus, the recovery of Pd(II) from wastes or secondary sources currently has great importance. A new ligand, namely, 11,17,23-tetrakis-[(p-methoxyphenyl)azo]-25,26,27,28-tetrakis[(dimethyl thiocarbamoyl)oxy]thiacalix[4]arene (MADTTCA), was investigated for the extraction of Pd(II) from a hydrochloric acid medium using chloroform as a diluent. Extraction data indicate that the extraction efficiency depends on the concentration of HCl, from 0.1–5.0M. The equilibrium extraction time of MADTTCA was achieved with a short contact time (15min), which made MADTTCA a suitable candidate for industrial applications. Notably, the maximum uptake capacity of MADTTCA for Pd(II) was found to be 417mg/L using 1.0mM MADTTCA. On the basis of the obtained data, the stoichiometric ratio between Pd(II) and MADTTCA was found to be 1:1. MADTTCA was shown to be highly effective at extracting Pd(II) from simulated mixed metal and automotive catalyst residue (ACR) solutions composed of six metal ions (PGMs), such as Pd(II), Pt(IV), Rh(II), Al(III), La(III) and Ce(III). More than 99.9% of the extracted Pd(II) was stripped with 0.1M thiourea in a 1.0M HCl solution. The title extractant was able to be recycled and reused at least five times without a significant loss of its extraction features. All of the obtained results revealed that MADTTCA can be used for the selective recovery of Pd(II) from ACR solutions.

Partial delignification of wood and membrane preparation using a quaternary ammonium ionic liquid

This work determined that southern yellow pine wood can almost be completely dissolved in the quaternary ammonium ionic liquid tetrabutylammonium acetate with dimethyl sulfoxide (in a 2:8 mass ratio), after minimal grinding, upon heating at 85 °C for three dissolution/reconstitution cycles, each 1.5 h. Approximately 34.6% of the native lignin and 67.4% of the native carbohydrates present in the original wood can subsequently be extracted, respectively, and were assessed. A gradual decrease in lignin with increased extraction cycles resulted in increased crystallinity index of the cellulose II in the cellulose-rich residue, as confirmed by X-ray diffraction. An increasingly homogeneous macrostructure in the cellulose-rich residue was also evident from scanning electron microscopy images. Membranes cast directly from either wood or cellulose-rich residue solutions in the same tetrabutylammonium acetate/dimethyl sulfoxide system, were prepared using a papermaking-like process. Morphological and mechanical studies indicated that lignin extraction made the membranes more uniform and flexible. Systematic increases in the fibril lengths and orientations of the recovered materials were also found with decreasing lignin contents on the basis of atomic force microscopy analysis. This work demonstrates that relatively efficient partial separation of pine wood and subsequent membrane preparation are possible using a quaternary ammonium ionic liquid.

Sorption of palladium(II) using organophosphorus derivatives based onthiacalix[4]arene impregnated resins from hydrochloric media

ABSTRACTThe sorption kinetics of Pd(II) from hydrochloric acid solutions by 1 and 2 impregnated Amberlite XAD-7 resins (3 and 4) have been systematically studied. Both impregnated resins selectively and efficiently adsorb Pd(II) from single metal solution and automotive catalyst residue solution. In comparison between 3 and 4, 4 showed more efficiency toward Pd(II) with respect to contact time, loading, and stripping capacities. 3 and 4 were characterized by XRD and SEM analyses before and after Pd(II) sorption. We also studied the reusability of 3 and 4 and both the resins offer excellent performance for three times.

Recovery of critical metals from dilute leach solutions – Separation of indium from tin and lead

The strategic metal indium is recovered from solutions containing tin and lead that are typical of those obtained from leach solutions of metal component fractions of electronic waste including the leach solutions from indium tin oxide thin film conductive layers that contain only indium and tin. Almost total recovery of the metals can be achieved from nitric, perchloric and acetic acid leach solutions using a novel cylindrical mesh electrode electrolysis cell under appropriate conditions. The optimum separation of indium from tin and lead is achieved by a novel three-stage process from nitric acid media in the presence of SCN− as a complexing agent. Lead is removed from dilute indium-tin-lead solutions in the first stage from 0.1molL−1 nitric acid solution by electrodeposition over an 8h period in the absence of SCN− to give a residual solution containing a maximum of 2mgL−1 of lead (97% recovery). Tin is removed in the second stage by electrodeposition over an 8h period from the solution after addition of 0.02molL−1 SCN− to give a maximum residual electrolyte tin concentration of 3mgL−1 (94% recovery). In the third stage indium is recovered at the anode of the cylindrical mesh electrode cell as an oxy-hydroxide phase by increasing the SCN− concentration to 0.1molL−1 and carrying out the electrolysis for a period of 24h to give a residual solution containing 1mgL−1 of indium (98% recovery).

Assessment of the Effects Exerted by Acid and Alkaline Solutions on Bone: Is Chemistry the Answer?

The treatment of corpses with extremely acid or basic liquids is sometimes performed in criminal contexts. A thorough characterization by chemical analysis may provide further help to macroscopic and microscopic analysis; 63 porcine bone samples were treated with solutions at different pH (1-14) for immersion periods up to 70 days, as well as in extremely acidic sulfuric acid solutions (9 M/18 M) and extremely basic sodium hydroxide. Inductively coupled optical emission spectrometry (ICP-OES)/plasma mass spectrometry (ICP-MS), Fourier transform infrared spectroscopy (FT-IR), energy dispersive X-ray analysis (EDX), X-ray powder diffraction (XRPD), and scanning electron microscopy (SEM) showed that only the sulfuric acid solution 18 M was able to completely dissolve the sample. In addition, chemical analysis allowed to recognize the contact between bone and substances. Hydrated calcium sulfate arose from extreme pH. The possibility of detecting the presence of human material within the residual solution was demonstrated, especially with FT-IR, ICP-OES, and EDX.

Optimizing the lanthanum adsorption process onto chemically modified biomaterials using factorial and response surface design

The rare metals' potential to pollute air, water, soil, and especially groundwater has received lot of attention recently. One of the most common rare earth group elements, lanthanum, is used in many industrial branches, and due to its toxicity, it needs to be eliminated from all residual aqueous solutions. The goal of this study was to evaluate the control of the adsorption process for lanthanum removal from aqueous solutions, using cellulose, a known biomaterial with high adsorbent properties, cheap, and environment friendly. The cellulose was chemically modified by functionalization with sodium β-glycerophosphate. The experimental results obtained after factorial design indicate optimum adsorption parameters as pH 6, contact time 60 min, and temperature 298 K, when the equilibrium concentration of lanthanum was 250 mg L−1, and the experimental adsorption capacity obtained was 31.58 mg g−1. Further refinement of the optimization of the adsorption process by response surface design indicates that at pH 6 and the initial concentration of 256 mg L−1, the adsorption capacity has maximum values between 30.87 and 36.73 mg g−1.

Water osmosis in separating acidic HCl/glyphosate liquor by continuous diffusion dialysis

Abstract Acidic HCl/glyphosate liquor is the intermediate product during the production of glyphosate herbicide. The liquor contains about 2.4 mol/L ( M ) HCl, 1.1 M glyphosate and 35 wt% other organic components, which can be separated by continuous diffusion dialysis (DD) to recover HCl. The residual solution is further precipitated to obtain glyphosate product at pH around 1.5. The continuous DD dialyzer equipped with commercial membrane TWDD-III shows high water osmosis coefficients of 2.23–5.98 × 10 −4 m/h, while the self-prepared QPPO/PVA membrane shows the lower values of 1.95–2.93 × 10 −4 m/h. The water osmosis is mainly attributed to the high content of organic solvent in the acidic liquor. The water osmosis reduces the Gly concentration and productivity together with the HCl recovery ( R H ), but the recovered HCl concentration (C d-H ) and Gly rejection ( η Gly ) are less affected. The flow rate and flow ratio between water and acidic liquor are optimized (0.63 L/(m 2 h), 3:1) to obtain C d-H of 1.01 M, R H of 80.9% and η Gly of 83.2% for the commercial membrane. The residual solution contains only 0.43 M Gly and thus needs to be highly concentrated to obtain 60.7% Gly productivity with the purity of 71.3%. The QPPO/PVA membrane under optimized running conditions (0.83 L/(m 2 h), 2:1) can obtain C d-H of 0.95 M, R H of 68.1% and η Gly of 94.2%. The residual solution contains 0.65 M Gly and thus needs less to be concentrated to precipitate Gly product due to the lower water osmosis.

Residual symmetry, interaction solutions, and conservation laws of the (2+1)-dimensional dispersive long-wave system**Project supported by the National Natural Science Foundation of China (Grant Nos. 11371293 and 11505090), the Natural Science Foundation of Shaanxi Province, China (Grant No. 2014JM2-1009), the Research Award Foundation for Outstanding Young Scientists of Shandong Province, China (Grant No. BS2015SF009), and the Science and Technology Innovation Foundation

We explore the (2+1)-dimensional dispersive long-wave (DLW) system. From the standard truncated Painlevé expansion, the Bäcklund transformation (BT) and residual symmetries of this system are derived. The introduction to an appropriate auxiliary dependent variable successfully localizes the residual symmetries to Lie point symmetries. In particular, it is verified that the (2+1)-dimensional DLW system is consistent Riccati expansion (CRE) solvable. If the special form of (CRE)-consistent tanh-function expansion (CTE) is taken, the soliton-cnoidal wave solutions and corresponding images can be explicitly given. Furthermore, the conservation laws of the DLW system are investigated with symmetries and Ibragimov theorem.

Carcass orientation and drip time affect potential surface water carryover for broiler carcasses subjected to a post-chill water dip or spray

To estimate the potential for residual antimicrobial solution carryover, surface water accumulation and loss was measured on post-chill carcasses that were either dipped or sprayed with water. For all experiments, broilers were slaughtered, soft or hard scalded, defeathered, and eviscerated. Carcasses were immersion chilled, allowed to drip, and post-chill carcass weight (CW) recorded. For water dip treatment, carcasses were dipped for 0.5 min in water and hung by a wing (n = 33) or a leg (n = 30) and CW recorded at 0, 0.5, 1, 2, and 5 min post-dip. For water spray treatment, individual carcasses were hung by either the wings (n = 35) or legs (n = 34) from a shackle suspended from a scale. Water was sprayed at 80 psi and post-spray CW recorded. Initial water accumulation (0 min) for dipped carcasses was not significantly different (P > 0.05) for carcasses hung by the leg (101.0 g) or wing (108.8 g). Following the 5 min drip time, 31 g of water remained on the carcasses hung by the leg and only 10 g on carcasses hung by the wing (P < 0.05). When carcasses were sprayed with water, initial water accumulation (0 min) was 62 g for carcasses hung by the legs and 60 g for carcasses hung by the wings (P > 0.05). Following the 5 min drip time, 1 g or no water remained on the sprayed carcasses (P > 0.05). Carcasses that were dipped and hung by a leg for 5 min retained significantly more water (31 g) than carcasses that were dipped and hung by a wing (10 g) or sprayed carcasses hung either way (0.3 g) (P < 0.05). Post-chill water dip resulted in significantly higher initial carcass water accumulation than spraying (105 g vs. 61 g, P < 0.05). Carcass orientation during dripping only affected the amount of retained water for dipped carcasses. Dipped carcasses hung by a leg have the highest potential for residual carcass antimicrobial solution carryover and sprayed carcasses hung by either orientation have the lowest potential for residual antimicrobial solution carryover.

A Family of Non-rough Cycles in a System of Two Coupled Delayed Generators

In this paper, we consider the nonlocal dynamics of the model of two coupled oscillators with delayed feedback. This model has the form of a system of two differential equations with delay. The feedback function is non-linear, finite and smooth. The main assumption in the problem is that the coupling between the generators is sufficiently small. With the help of asymptotic methods we investigate the existence of relaxation periodic solutions of a given system. For this purpose, a special set is constructed in the phase space of the original system. Then we build an asymptotics of the solutions of the given system with initial conditions from this set. Using this asymptotics, a special mapping is constructed. Dynamics of this map describes the dynamics of the original problem in general. It is proved that all solutions of this mapping are non-rough cycles of period two. As a result, we formulate conditions for the coupling parameter such that the initial system has a two-parameter family of nonrough inhomogeneous relaxation periodic asymptotic (with respect to the residual) solutions.

Comparison of methods of zeta potential and residual turbidity of pectin solutions using calcium sulphate/aluminium sulphate as a precipitant

The affinity of calcium ion binding from CaO used in the most common process of purification of sugar beet juice is relatively low. Therefore, large amounts of this compound are required. This paper presents the theoretical basis of a novel sugar beet juice purification method based on the application of the binary system CaSO4/Al2(SO4) . In order to monitor the process of coagulation and precipitation of pectin in the presence of CaSO4/Al2(SO4)3, two methods were compared: measurement of the zeta potential and of residual solution turbidity. The zeta potential of pectin solution was determined by electrophoretic method, while the residual turbidity was determined by spectrophotometry. Two model solutions of pectin (0.1 % w/w) were investigated. Studies were performed with 10 different concentrations of the binary solution CaSO4/Al2(SO4)3 (50 - 500 g dm-3). The amount of the precipitant CaSO4/Al2(SO4)3 (1:1 w/w) needed to achieve the minimum solution turbidity and charge neutralization of pectin particles (zero zeta potential) were measured and compared. Colloidal destabilization occurred before a complete neutralization of the surface charge of pectin particles (zeta potential ~ 0 mV). Optimal quantities (490 - 705 mg g-1 pectin) of the applied binary mixture, were obtained using both methods. This is much lower than the amount of CaO that is commonly used in the conventional process of sugar beet juice purification (about 9 g? g-1 pectin). The use of these precipitants could be important from both economic and environmental point of view.

Neurodegenerative Diseases: Where To Go From Now? Thought Provoking Through Ca2+/cAMP Signaling Interaction

Science is not always linear! Imagine this scenario: The PhD researcher and his supervisor are formulating their experiment. During the experiment course, there is on the bench a residual solution containing Verapamil, an L-type Ca2+ channel blocker (CCB). In a relapse, the PhD researcher decides to add this solution in an isolated smooth muscle preparation. The smooth muscle was prior relaxed with a drug that increased the cAMP cytosolic concentration. According to the classical receptor theory, addition of verapamil in the smooth muscle preparation should enhance the relaxation of the smooth muscle! To his surprise, the PhD researcher observed an incredible contraction of the smooth muscle! Perplexed with this result, the PhD researcher and his supervisor did not know how to explain this phenomenon immediately

Factors influencing the aggregation behavior of residual associative polymer in produced oily fluids

The influence of emulsified oil, suspended solids, Fe3+, Fe2+, cationic water clarifier and sulfate-reducing (SR) bacteria on the aggregation behavior of residual hydrophobic modified polyacrylamide in treated oily wastewater from polymer flooding was studied by fluorescence spectroscopy and dynamic light scattering. The result of I1/I3 showed that the polarity of hydrophobic microdomains increased, whereas the size of the hydrophobic microdomains may be decreased, where the value of I1/I3 represents the ratio of the intensity of peak I1 (374.0 nm) to that of peak I3 (385.0 nm) of the vibration fine structure of pyrene monomer emission in residual polymer solution. The results of the ratio of I1 at 48 h to I1 at 0 h (I1,48h/I1,0h) indicated that oil and cationic water clarifier could inhibit the aggregation to some extent, while Fe2+ and suspended solids were helpful for aggregation, and Fe3+ and SR bacteria had no significant influence on the aggregation of polymer.