In order to simultaneously improve the strength and decoration properties of plantation wood, a multi-effect modifier was prepared by compounding acid red 18050(G) with melamine-modified urea ...formaldehyde resin (MUF). Various compounding methods for MUF synthesis such as adding dye with the first part urea (U1G) or with the second part urea (U2G), or direct blending with MUF resin (BG) were tested. Chinese fir plantation wood was impregnated with these modifiers separately, and its color, color fastness, and dyeing mechanism were studied. The results showed that G had good compatibility with MUF and could prolong its storage time, and all compound modifiers exhibited permeability and coloring effect on Chinese fir wood. Compared with G-dyed wood under the same conditions, all the compound dyed wood had better color fastness to water, and the U2G-dyed was the best, the color fastness to xenon light of U2G dyed wood was greatly improved.. Fourier transform infra-red (FTIR) analysis showed that compared with MUF-modified wood, the dye affected MUF hydroxyl-methylation reaction in U1G, lowered the polycondensation degree, and extended its storage time. The dye might have promoted the ionic reaction between resin amino and dye sulfonic groups in U2G, thus displaying better color fastness.
Introduction:
Modified ultrafiltration (MUF) is employed at the termination of cardiopulmonary bypass (CPB) in pediatric and neonatal patients undergoing congenital heart surgery to reduce the ...accumulation of total body water thus increasing the concentration of red blood cells and the other formed elements in the circulation. Modified ultrafiltration has been reported to remove circulating pro-inflammatory mediators that result in systemic inflammatory response syndrome (SIRS) postoperatively.
Methods:
Four hundred patients undergoing cardiac surgery requiring cardiopulmonary bypass and weighing less than or equal to 12 kg were retrospectively evaluated for the effectiveness of MUF. After the termination of CPB, blood was withdrawn through the aortic cannula and passed through a hemoconcentrator attached to the blood cardioplegia set and returned to the patient through the venous cannula. The entire CPB circuit volume in addition to the patient’s circulating blood volume were concentrated until the hematocrit value displayed on the CDI cuvette within the MUF circuit reached 45% or there was no more volume to safely remove. At the same time a full unit of FFP can be infused as water is being removed, thus maintaining euvolemia.
Results:
MUF was performed in all 400 patients with no MUF-related complications. Following the conclusion of MUF, anecdotal observations included improved surgical hemostasis, improved hemodynamic parameters, decreased transfusion requirements, and decreased ventilator times.
Conclusions:
Complete MUF enables the clinician to safely raise the post-CPB hematocrit to at least 40% while potentially removing mediators that could result in SIRS. In addition a full unit of FFP can be administered while maintaining euvolemia.
•Model of integrated scheduling at terminals with uncertain factors are formulated.•A PSO (particle swarm optimization) algorithm is stated for solving the problem.•Numerical studies are conduced to ...test the model and the PSO algorithm.•Operation of parallel discharging and loading is our further study direction.
This paper proposes a PSO (particle swarm optimization)-based integrated optimization of container terminal scheduling with uncertain factors. It explores uncertain factors of yard truck travel speed, yard crane speed and unit time of yard crane hoisting/lowing operation, which are not considered in classical literature. On the basis of it, an integrated scheduling optimization model is suggested. The objective of the model is to minimize the operation time of the yard crane with the coordination of the quay crane and yard truck. To solve this difficult combinatorial problem, the PSO algorithm is developed. PSO is evaluated for combinatorial problems with uncertain factors, which represents a new application of PSO. Different from published literatures, our study findings can be presented in two aspects. One is in the modeling. This includes (i) formalizing the description of the purpose of the model; (ii) a real-world coordination of three equipments that incorporate in uncertain circumstances. The other is that the PSO algorithm is applied to deal with integrated scheduling with uncertain factors whose results can be gotten in permitted time with stability and satisfactory. Numerical experiments show that the model gives systemic simulation for the whole scheduling process with uncertain factors. And the results are stable and acceptable in allowable CPU time. Furthermore, compared with the results in determined context, the model with uncertain factors can get a more stable solution and guarantee the objective function to achieve sufficiently optimal results.
A low-cost sepiolite (SEP) was used to replace wheat flour (WF) as a filler applied to melamine-urea-formaldehyde (MUF) resin. Three-ply plywood was fabricated with different SEP/WF formulations, and ...its wet shear strength and formaldehyde emission were tested. Scanning electron microscopy (SEM) and X-ray diffraction (XRD) were used to explain why the performance of the plywood improved. Results showed that the wet shear strength of the plywood increased with the addition of SEP in the filler. When using SEP to replace 80% of the WF, the wet shear strength was improved by 27.8%, which was attributed to the penetration network with hydrogen bonds formed by SEP and MUF resin. Using SEP in the filler formulation created a smoother, denser, and more regular cross-section to prevent moisture intrusion, which improved the water resistance of the adhesive and thus further increased the wet shear strength of the resultant plywood. The tunnel structure of SEP could accelerate the free formaldehyde emission of the plywood. As a result, using SEP replace 80% WF as a filler, the formaldehyde emission of the plywood was reduced by 7.8% due to the tunnel release effect.
To improve the safety of ammonium nitrate explosives, the melamine urea-formaldehyde resin (MUF resin) was selected for the preparation of three typical nitramine explosives ...(cyclotetramethylenetetranitramine, HMX; cryclo-trimethylenetrinitramine, RDX; and hexanitrohexaazaisowurtzitane, CL-20) based green polymer-bonded explosives (GPBXs) via interfacial polymerization. Meanwhile, the corresponding composite particles prepared by physical mixing and drying bath methods were studied and compared. The particle morphology, crystal structure, thermal stability, and safety performance of the resultant composite particles were characterized by scanning electron microscopy (SEM), powder X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectra, differential scanning calorimeter (DSC), and impact sensitivity test, respectively. SEM results showed that MUF was successfully coated on the surface of the three explosives, and different composite particles prepared by the same method have their own unique characteristics. Such effect is attributed to the resin’s ability to isolate and buffer external stimuli. It is obvious that the interfacial polymerization is an effective desensitization technique to prepare core-shell composite particles for explosives.
Soil properties, enzyme activity, and microbial functional diversity coevolve with soil processes. Consequently, activity and diversity of soil enzymes could be used for evaluating the natural ...processes in ecosystems and their changes but, for applied management strategies, useful cost-effective methods and synthetic indicators are required. The aim of this study was to use API ZYM (API) assay to evaluate the fingerprint of soil enzyme activity and microbial functional diversity in relation to soil processes. To strengthen the results, a parallel measurement of enzyme activities was performed with microplate-fluorometric (FA) assay. Seven soil profiles classified as
Haploxeralf
, located in two Mediterranean areas under
xeric
moisture and
mesic
temperature soil regimes, were selected. The Synthetic Enzyme Index (SEI) was calculated as the sum of 16 enzyme activities determined according to the two methods (SEI–API and SEI–FA). Moreover, the enzyme activities were used to assess the microbial functional diversity through the calculation of the Shannon’s diversity index (H’ API and H’ FA). The results showed a relationship between SEI–API and SEI–FA which was described by a linear model. Moreover, a significant linear regression was also found between the Shannon’s diversity indices calculated according to the two methods, H’ API and H’ FA. Significant differences were found from surface A to deep Bt genetic horizons in a decreasing gradient of enzyme activity and microbial functional diversity. For subsurface horizons, the SEI–API was significantly higher in E than AB horizons, suggesting that API method can detect the different biochemical behaviour in eluviation processes occurring in Haploxeralfs. API ZYM assay proved to be suitable for a general biochemical evaluation and for assessing microbial functional diversity in soils of different origin, composition, and land uses. For this reason, it can be proposed as a simple cost-effective method to use during the soil survey.
Factors determining C turnover and microbial succession at the small scale are crucial for understanding C cycling in soils. We performed a microcosm experiment to study how soil moisture affects ...temporal patterns of C turnover in the detritusphere. Four treatments were applied to small soil cores with two different water contents (matric potential of −0.0063 and −0.0316MPa) and with or without addition of 13C labelled rye residues (δ13C=299‰), which were placed on top. Microcosms were sampled after 3, 7, 14, 28, 56 and 84 days and soil cores were separated into layers with increasing distance to the litter. Gradients in soil organic carbon, dissolved organic carbon, extracellular enzyme activity and microbial biomass were detected over a distance of 3mm from the litter layer. At the end of the incubation, 35.6% of litter C remained on the surface of soils at −0.0063MPa, whereas 41.7% remained on soils at −0.0316MPa. Most of the lost litter C was mineralised to CO2, with 47.9% and 43.4% at −0.0063 and −0.0316MPa, respectively. In both treatments about 6% were detected as newly formed soil organic carbon. During the initial phase of litter decomposition, bacteria dominated the mineralisation of easily available litter substrates. After 14 days fungi depolymerised more complex litter compounds, thereby producing new soluble substrates, which diffused into the soil. This pattern of differential substrate usage was paralleled by a lag phase of 3 days and a subsequent increase in enzyme activities. Increased soil water content accelerated the transport of soluble substrates, which influenced the temporal patterns of microbial growth and activity. Our results underline the importance of considering the interaction of soil microorganisms and physical processes at the small scale for the understanding of C cycling in soils.
This work attempted to manufacture glued-laminated timber (Glulam) bonded with melamine-urea-form-aldehyde (MUF) resin adhesives at various melamine contents from 20% to 50% under high frequency (HF) ...heating for a very short time. Two preparation methods were employed to prepare MUF resin adhesives with different melamine contents: one-batch method of synthesizing MUF resins in a single batch, and two-batch method of mixing urea-formaldehyde (UF) resin with melamine-formaldehyde (MF) resin that had been synthe-sized separately. As the melamine content increased, the gelation time and peak temperature of MUF resins decreased. The adhesion performance of plywood showed that the one-batch MUF resin adhesive with 50% mel-amine content only satisfied the standard requirement of water resistance. Thus, the one-batch MUF resin adhe-sive with 50% melamine content was applied for bonding wood lamina from four softwood species such as Japanese larch, Korean red pine, Korean pine and Japanese cedar to manufacture Glulam under HF heating. All Glulam samples bonded with the one-batch MUF resin adhesives with 50% melamine content except those from Korean Red Pine satisfied the requirement in water soaking or boiling water delamination test as an exterior grade Glulam. The presence of rosin in Korean Red Pine was believed to be responsible for its poor adhesion. These results showed that the one-batch MUF resin adhesives with 50% melamine content provided acceptable water resistance with exterior grade Glulam manufactured under HF heating.
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