Dry Procedure Research Articles

Viability Study of a Safe Method for Health to Prepare Cement Pastes with Simultaneous Nanometric Functional Additions

The use of a mixing method based on a novel dry dispersion procedure that enables a proper mixing of simultaneous nanometric functional additions while avoiding the health risks derived from the exposure to nanoparticles is reported and compared with a common manual mixing in this work. Such a dry dispersion method allows a greater workability by avoiding problems associated with the dispersion of the particles. The two mixing methods have been used to prepare Portland cement CEM I 52.5R pastes with additions of nano‐ZnO with bactericide properties and micro‐ or nanopozzolanic SiO2. The hydration process performed by both mixing methods is compared in order to determine the efficiency of using the method. The hydration analysis of these cement pastes is carried out at different ages (from one to twenty‐eight days) by means of differential thermal analysis and thermogravimetry (DTA‐TG), X‐ray diffraction (XRD), scanning electron microscopy (SEM), and Fourier transform infrared spectroscopy (FTIR) analyses. Regardless of composition, all the mixtures of cement pastes obtained by the novel dispersion method showed a higher retardation of cement hydration at intermediate ages which did not occur at higher ages. In agreement with the resulting hydration behaviour, the use of this new dispersion method makes it possible to prepare homogeneous cement pastes with simultaneous functional nanoparticles which are physically supported on the larger particles of cement, avoiding exposure to the nanoparticles and therefore minimizing health risks. Manual mixing of cement‐based materials with simultaneous nanometric functional nanoparticles on a large scale would make it difficult to obtain a homogenous material together with the health risks derived from the handling of nanoparticles.

Fast and reliable generation of [18F]triflyl fluoride, a gaseous [18F]fluoride source.

A novel strategy for the production of reactive [18F]fluoride has been developed, omitting time consuming azeotropic drying procedures. Gaseous [18F]triflyl fluoride is formed instantaneously at room temperature from hydrated [18F]fluoride, followed by distillation in less than 5 minutes into a dry aprotic solvent, in which dry [18F]fluoride is released in presence of base with >90% radiochemical yield. The reactivity of the [18F]fluoride has been confirmed by reaction with several model compounds and by the synthesis of the PET tracers [18F]fluoroestradiol ([18F]FES) and O-2-[18F]fluoroethyl-l-tyrosine ([18F]FET), providing good isolated radiochemical yields and molar activities of up to 123 GBq μmol-1.

Studies on the Proximate Composition, Quality and Heavy Metal Concentration of Sun-dried Bombay Duck and Sun-dried Ribbon Fish of Cox’s Bazar District of Bangladesh

Proximate composition, quality aspect and heavy metal concentration of sun-dried Bombay Duck (Harpodon nehereus) and sun-dried Ribbon fish (Trichiurus haumela) were studied in a series of laboratory experiments. Sun-dried fishes were collected from a fish market of Cox‟s Bazar town. These sun-dried marine fishes were collected from the stock after first drying procedure. Organoleptically most of these sun-dried fishes were in „B‟ grade that means in „Good‟ condition (SDP 2.33 and 2.35 respectively). Crude Protein, Lipid, Moisture, Ash, TVB-N and TMA-N content (%) of sun-dried Bombay Duck (Harpodon nehereus) was 32.21±1.05 %, 3.51±0.38 %, 37.26±0.70 %, 16.22±0.56 %, 115.45±1.73 mg/100g, 9.37±0.13 mg/100g respectively. Whereas in sun-dried Ribbon fish (Trichiurus haumela) the content (%) of Crude Protein, Lipid, Moisture, Ash, TVB-N and TMA-N was 31.64±1.28 %, 5.06±0.10 %, 35.78±0.97 %, 12.33±0.27 %, 107.69±1.37 mg/100g and 9.91±0.23 mg/100g respectively. Heavy metal concentration i.e. Cd, Cr, Pb, Cu and Zn concentration (ppm) in sun-dried Bombay Duck (Harpodon nehereus) was 0.82, 8.38, 8.28, 2.21, 55.38 ppm. Whereas heavy metal concentration (ppm) in sun-dried Ribbon fish (Trichiurus haumela) was Cd 0.48 ppm, Cr 6.96 ppm, Pb 5.46 ppm, Cu 1.40 ppm, Zn 19.95 ppm.J. Environ. Sci. & Natural Resources, 10(1): 55-60 2017

Studies on the Proximate Composition, Quality and Heavy Metal Concentration of two Sun-Dried Marine Fish (Sun-Dried Silver Pomfret and Sun-Dried Perch) of Cox’s Bazar District of Bangladesh

This research was conducted on the proximate composition, quality aspect and heavy metal concentration of sun-dried Silver Pomfret (Stromateus cinereus) and sun-dried Perch (Lates calcarifer) which were collected from local market of Cox‟s Bazar town. These sun-dried marine fishes were collected from the stock after first drying procedure. Organoleptically most of these sun-dried fishes were in „excellent‟ grade some were in „Good‟ grade. Crude Protein, Lipid, Moisture, Ash, TVB-N and TMA-N content (%) of sun-dried Silver Pomfret (Stromateus cinereus) was 32.25±1.50, 7.75±0.20, 39.59±0.34, 15.75±0.39, 85.68±1.60 and 8.41±0.37 respectively. Whereas in sun-dried Perch (Lates calcarifer) the content (%) of Crude Protein, Lipid, Moisture, Ash, TVB-N and TMA-N was 40.31±2.13, 5.03±0.55, 26.74±0.47, 11.50±0.26, 46.97±1.00 and 8.21±0.12 respectively. Heavy metal concentration i.e. Cd, Cr, Pb, Cu and Zn concentration (ppm) in sun-dried Silver Pomfret (Stromateus cinereus) was 0.68, 5.85, 8.43, 1.15, 24.93 ppm. Whereas heavy metal concentration (ppm) in sun-dried Perch (Lates calcarifer) was Cd 0.65 ppm, Cr 5.6 ppm, Pb 6.28 ppm, Cu 1.04 ppm, Zn 23.8 ppm.J. Environ. Sci. & Natural Resources, 10(1): 25-32 2017

Electrical Heating‐Assisted Multiple Coating Method for Fabrication of High‐Performance Perovskite Fiber Solar Cells by Thickness Control

AbstractAlthough methods for perovskite morphology and thickness control have significantly improved the power conversion efficiency (PCE) of planar solar cell, they are rarely investigated in the field of fiber solar cell. Electrical heating‐assisted multiple coating, as a solution‐based film process, is proposed for the first time to control perovskite coverage and thickness on metal fiber. It solves the challenges by continuous deposition and hot coating technique. Study of film formation mechanism indicates that adding a drying procedure ensures steady deposition during continuous coating. Continuous deposition feature allows improving film coverage and controlling thickness by simply changing the number of coating times, which differentiate this method from other techniques. In addition, electrical heating is applied to accelerate film formation and perovskite transformation. Thus, a fully covered thin film of perovskite is obtained due to the improved perovskite loading and homogeneity. Corresponding devices achieve a high average PCE of 6.58% with a narrow standard deviation of 0.558. Above that, characterizations demonstrate difficulties in balancing high coverage and appropriate thickness accounts for the wide distribution of PCE and poor reproducibility. It is anticipated this method can move the field toward high efficiency and reproducibility goals.

Formation mechanisms of Si3N4 microstructures during silicon powder nitridation

Silicon nitride (Si3N4) was synthesized under a nitrogen gas flow (100mL/min) using a molten salt nitriding method to investigate the effects of the temperature and NaCl content on the α-Si3N4 content in products and their micro-morphologies. Adding NaCl and β-Si3N4 in silicon powders resulted in Si nitridation products divided into two layers. Analysis of the lower product using X-ray diffraction revealed a change in the α-Si3N4 content with changes in the temperature and NaCl content. Analysis of the lower and upper layers using scanning electron microscopy revealed that the upper layer contained Si3N4 nanowires, Si3N4 nanobelts, and clastic oxide impurities; the lower one contained short needle-like and blocky Si3N4. From the microstructures of the products, the product morphology related to that the dry mixing procedure did not correspond to homogenization of the starting Si-Si3N4-NaCl mixtures and the different concentrations of raw materials resulted in different morphologies.

Microbial Investigation of Recreation Effects on Water and Soil in the Tatra National Park

Abstract Tatra National Park is considered as the most visited protected area in Slovakia. Striking a balance between the preservation of natural resources and opportunities for public recreation often forces responsible authorities to make compromises between visitation impacts and protection. In this case, the microbial investigation of recreation effects on water and soil in the Tatra National Park were studied. The study areas were two valleys – Malá Studená, accessible by trail from south with higher human impact and visitation, including mountain huts Téryho and Zamkovského chata and Javorová, accessible from the northern part with a low number of visitors. Soil samples were taken from the main path, 30 cm away from it and water samples from or near the main path in both valleys. The selected colonies, after the cultivation on TSA medium were also analysed according to the dry and semi-extraction procedure of MALDI–TOF method. Most of the obtained strains are endospore forming, psychrotolerant species like Pseudomonas, Bacillus or Paenibacillus away of path, which corresponds with the climate and geographical conditions. But, the relatedness of soil sample strains in both valleys increases with rising altitude, with distance away from path; in contrast, the relatedness of water samples strains in both valleys increases with increasing distance sample areas from chalet and frequent visitors’ places. Water and soil samples were processed for community level physiological profiling using Biolog EcoPlates. The obtained results of carbon source utilization abilities of bacterial communities in both valleys suggested lower diversity in Javorová Valley, which corresponds probably with less visitor intensity, with less anthropogenic impact as well as with less risk of xenobiotics presence in environment.

Optimization and performance evaluation of silk fabrics dried in the domestic dryer

To determine the optimal drying procedure for large load and non-ironing procedure for small load when silk fabrics were drying-cared in daily usage; change in appearance, mechanical properties and microstructure of silk fabrics before and after drying with various drying parameters (heater power, air velocity and drum-rotating speed) were investigated. Results revealed that the performance of silk fabric after drying is more sensitive to air velocity (humidity of drying-air) rather than heater power (temperature). Heater power of 3000W, air velocity of 8.5m/s and drum rotating speed of 45-50rpm (No.2) was proved to be optimal for drying silk fabrics due to its ideal smoothness appearance, dimensional stability and drying efficiency. When consumers dry a small amount of clothes, a drying procedure of heater power of 3000W, air velocity of 8.5m/s and drum-rotating speed of 0rpm (No.6) is more reasonable procedure because it reduces or eliminates ironing. And indicating drying in dryer can be an effective alternative to indoor-drying or sunlight-drying if suitable procedure being set. This finding provided reference for manufacturers to design and improve of dryers, especially for drying procedures optimization of delicate textiles, and consumers a feasible care method without reducing the quality of fabric.

Effect of Different Drying Procedures on the Nutritional Value of the Mantle and Tentacles of Sepia officinalis

AbstractThe aim of this work was to investigate the influence of two different drying methods, traditionally by sun and controlled temperatures of 45, 50, 60 and 70 °C and relative humidity of 20 and 30% on the chemical composition of Sepia officinalis. When compared to fresh samples, lipid content increased under both drying methods whereas protein levels significantly increased only under controlled conditions. Drying procedures increased the percentage of saturated fatty acids mainly in sun‐dried samples and at high temperature (70 °C). A significant decrease in the amount of polyunsaturated fatty acids was detected in sun‐dried samples. No significant differences were found between the levels of polyunsaturated fatty acids of fresh cuttlefish and those under controlled conditions. The highest value of malondialdehyde in mantles was observed in sun‐dried samples, while in tentacles the highest level was seen at 70 °C. The highest level of advanced oxidation protein products was noted in traditionally sun‐dried samples. The results obtained showed that 45–50 °C and 20–30% humidity conserved the value of proteins and lipids more than traditional drying. Results of this study may be suitable for developing a reliable industrial index.

Mesoporous molecular sieves containing niobium(V) as catalysts for the epoxidation of fatty acid methyl esters and rapeseed oil

Niobium-containing mesoporous silica (Nb–SiO2) catalysts, which showed previously promising performances in the liquid-phase epoxidation of alkenes, were here applied to the epoxidation of unsaturated fatty acid methyl esters (FAMEs), selectively hydrogenated FAMEs and rapeseed oil triglyceride with aqueous hydrogen peroxide. Niobium-silica solids were prepared via grafting of niobocene dichloride onto the surface of different porous silica-based supports (non-ordered SiO2, ordered mesoporous MCM-41 and SBA-15 molecular sieves) via a dry impregnation procedure. Promising performance with very good selectivity towards desired monoepoxides were obtained, in particular over a Nb-grafted silica catalyst prepared from a commercial non-ordered silica support.

Fortification of Ogi with Whey Increases Essential Amino Acids Content of Fortified Product.

The inability of humans to synthesize essential amino acids (EAA) necessitates the need to increase the levels of these nutrient molecules in certain foods in which they are deficient. Maize ogi is a typical food product for both infants and adults in Africa, but with poor EAA content. This study therefore sought to assess the possibility of increasing the EAA content in maize ogi by processing it with cheese whey instead of water. Maize ogi and whey-fortified ogi were prepared by the usual procedure of grain soaking, milling, and drying. Samples from both treatments were subjected to proximate composition and amino acid profile analyses using Waters 616/626 LC (HPLC) instrument. L-lysine, L-trytophan, and L-methionine contents in maize ogi remarkably increased from 0.52, 0.15, and 0.90 mg/100 gm sample, respectively, to 0.90, 240, and 1.320 mg/100 gm sample in whey-fortified ogi. There were also significant increases in other EAA contents of whey-fortified ogi relative to its counterpart (normal maize ogi). The sum increase in EAA contents (9,405 mg) correlates with the increase in protein (1 gm) per gram sample. This study demonstrates that cheese whey increases EAA content in maize ogi and suggests that whey-fortified maize ogi may be a preferred alternative to water processed maize ogi.

Quantitative determination of residual 1,4-dioxane in three-dimensional printed bone scaffold

SummaryBackground/ObjectiveA novel porous scaffold poly (lactide-co-glycolide) and tricalcium phosphate (PLGA/TCP) was developed by three-dimensional printing technology for bone defect repair. As a Class 2 solvent with less severe toxicity, content of residual 1,4-dioxane in this newly developed scaffold should be rigorously controlled when it is translated to clinical use. In this study, a headspace gas chromatography-mass spectrometric (HS-GC-MS) method and related testing protocol were developed for quantitative determination of 1,4-dioxane in the PLGA/TCP composite scaffolds.MethodsMatrix effect analysis was used to optimise the pretreatment method of the scaffolds. Then, the procedure for testing 1,4-dioxane using HS-GC-MS was set up. The accuracy, precision, and robustness of this newly developed quantitative method were also validated before quantification of 1,4-dioxane in the scaffolds with different drying procedures.ResultsDimethyl formamide (DMF) was the optimal solvent for dissolving scaffolds for GC-MS with proper sensitivity and without matrix effect. Then, the optimised procedure was determined as: the scaffolds were dissolved in DMF and kept at 90°C for 40 minutes, separated on a HP-5MS column, and detected by mass spectroscopy. Recovery experiments gave 97.9–100.7% recovery for 1,4-dioxane. The linear range for 1,4-dioxane was determined as 1–40 ppm with linear correlation coefficient ≥ 0.9999. Intraday and interday precision was determined as being within relative standard deviation of below 0.68%. The passable drying procedure was related to lyophilising (−50°C, 50 Pa) the scaffolds for 2 days and drying in vacuum (50 Pa) for 7 days.ConclusionThis is the first quantitative method established to test 1,4-dixoane in a novel scaffold. This method was validated with good accuracy and reproducibility, and met the methodological requirements of the Guideline 9101 documented in the Chinese Pharmacopoeia 2015 Edition.The translational potential of this articleThis quantitative method for determination of residual 1,4-dioxane in the novel scaffolds is a key technical method during its translation into clinical use because this method is an important and indispensable file in the enterprise standard when the porous scaffold is registered as a Class III implanted medical device for bone defect repair, which is used to guarantee the safety of the scaffolds. It is also applied to optimise the drying process of scaffolds and to monitor the quality of scaffolds in the industrialisation process. Further, this method provides references for other solvents quantitative determination in porous scaffolds or materials.

Research into technological process of convective fruit drying in a solar dryer

We proposed a generalized procedure of convective fruit drying, which takes into account comprehensive combination of thermal-physical and physical-chemical properties of fruit with their kinematic heat and mass exchange characteristics. We developed a mathematical model of heat, moisture and mass exchange for convective fruit drying, which considers moisture-yielding velocity of the dried material in the operation zone of the heat carrier under conditions of diffusion process of moisture transfer in the dried material. The given model allows us to determine heat and mass exchange characteristics and intensity of the drying process. We proposed the systems of differential equations of heat and moisture transfer in the process of convective fruit drying for parabolic and uniformed original distribution of temperature and moisture content. As a result of the solution of a system of differential equations, we obtained appropriate dependences to determine the energy of bound moisture, moisture content on the surface and in the center of the material, difference of moisture content between the surface and central layers, as well as critical moisture content. The obtained results may be used when predicting the heat and mass exchange processes, for improvement of technology and equipment for fruit drying in the solar dryer, for increasing technological and energy efficiency of the process.

Moisture Influence Reducing Method for Heavy Metals Detection in Plant Materials Using Laser-Induced Breakdown Spectroscopy: A Case Study for Chromium Content Detection in Rice Leaves.

Fast detection of heavy metals in plant materials is crucial for environmental remediation and ensuring food safety. However, most plant materials contain high moisture content, the influence of which cannot be simply ignored. Hence, we proposed moisture influence reducing method for fast detection of heavy metals using laser-induced breakdown spectroscopy (LIBS). First, we investigated the effect of moisture content on signal intensity, stability, and plasma parameters (temperature and electron density) and determined the main influential factors (experimental parameters F and the change of analyte concentration) on the variations of signal. For chromium content detection, the rice leaves were performed with a quick drying procedure, and two strategies were further used to reduce the effect of moisture content and shot-to-shot fluctuation. An exponential model based on the intensity of background was used to correct the actual element concentration in analyte. Also, the ratio of signal-to-background for univariable calibration and partial least squared regression (PLSR) for multivariable calibration were used to compensate the prediction deviations. The PLSR calibration model obtained the best result, with the correlation coefficient of 0.9669 and root-mean-square error of 4.75 mg/kg in the prediction set. The preliminary results indicated that the proposed method allowed for the detection of heavy metals in plant materials using LIBS, and it could be possibly used for element mapping in future work.

Microfibrillated cellulose foams obtained by a straightforward freeze–thawing–drying procedure

Microfibrillated cellulose (MFC) is continuously gaining attention due to its outstanding mechanical properties, in particular high strength-to-weight ratio. Recently, more and more studies target the production of porous materials, such as foams, out of this natural resource. Commonly, an energy-consuming freeze–drying method is utilized for producing pure MFC porous structures from water-based suspensions, which renders these products particularly unattractive for industry. Although alternatives for foam production have been proposed, using either modified MFC or with various additives, the freeze–drying step is still one of the most critical bottle-neck of MFC foam production upscaling. A novel straightforward freeze–thawing–drying procedure assisted by the common additive urea was herein proposed. Such method allows the production of mechanically stable, lightweight MFC structures under low-cost ambient conditions drying. The influence of the cellulose fibril characteristics, the suspension formulation and the process parameters on the final foam properties have been studied in terms of porosity, density and mechanical properties.

Enhancing the Regeneration Process of Consumed NaBH4 for Hydrogen Storage

AbstractSodium borohydride (NaBH4) is regarded as an excellent hydrogen‐generated material, but its irreversibility of hydrolysis and high cost of regeneration restrict its large‐scale application. In this study a convenient and economical method for NaBH4 regeneration is developed for the first time without hydrides used as starting materials for the reduction process. The real hydrolysis by‐products (NaBO2·2H2O and NaBO2·4H2O), instead of dehydrated sodium metaborate (NaBO2), are applied for the regeneration of NaBH4 with Mg at room temperature and atmospheric pressure. Therefore, the troublesome heat‐wasting process to obtain NaBO2 using a drying procedure at over 350 °C from NaBO2·xH2O is omitted. Moreover, the highest regeneration yields of NaBH4 are achieved to date with 68.55% and 64.06% from reaction with NaBO2·2H2O and NaBO2·4H2O, respectively. The cost of NaBH4 regeneration shows a 34‐fold reduction compared to the previous study that uses MgH2 as the reduction agent, where H2 is obtained from a separate process. Furthermore, the regeneration mechanism of NaBH4 is clarified and the intermediate compound, NaBH3(OH), is successfully observed for the first time during the regeneration process.

Effects of aggregates size and glucose addition on soil organic carbon mineralization and Q10 values under wide temperature change conditions

Soil organic carbon mineralization (SOCmin) plays an important role in soil carbon (C) cycling in terrestrial ecosystems. The contribution of soil aggregates (Sa) to SOCmin and the effects of glucose addition on temperature sensitivity of SOCmin (Q10) are not clear. A laboratory incubation experiment has been set to examine the SOCmin of Sa by changing the soil temperature and adding glucose. The undisturbed soil samples (CK) were separated into four aggregate size fractions (<0.25, 0.25–1, 1–2 and 2–4 mm diameter) using a dry sieving procedure. The resulted showed that SOCmin in the 1–2 mm aggregates were higher than that in other size of aggregates. Q10 values of 0.25–1 mm aggregates were significantly higher than that in other size classes (P <0.05) in 10–30 °C range. However, In 30–50 °C range, the Q10 values of 1–2 mm aggregates were significantly higher than that in other size classes (P <0.05). The addition of glucose in soil could break the restrain effect of high temperature on SOCmin. However, glucose addition significantly reduced the Q10 values in 10–30 °C range (P <0.05). Although 1–2 mm aggregates could generate a positive feedback for temperature change in CO2 production, this aggregates were not the main CO2 emission source because of the low aggregates ratio (5.76%). The <1 mm aggregates in our incubation conditions were the main CO2 emission source because of their high aggregates ratio (80.35%) in soil.

Analysis of Manufacturing of Portland Cement Por with the Chemical Components

Portland is pressure driven make by finely beating the clinker made by calcining to early mix a blend of argillaceous and in like way calcareous supplies. It encounters a designed response with water units and sets when related with air or what's increasingly brought down In this paper we are discussing two differentiating structure to fabricate strong that are wet system and dry procedure. Wet methodology minerals are wet ground by including water to shape a slurry and a short period of time later dried. Dry procedure minerals are dry ground to shape a powder like substance.

Low Hysteresis Carbon Nanotube Transistors Constructed via a General Dry-Laminating Encapsulation Method on Diverse Surfaces.

Electrical hysteresis in carbon nanotube thin-film transistor (CNTTFT) due to surface adsorption of H2O/O2 is a severe obstacle for practical applications. The conventional encapsulation methods based on vacuum-deposited inorganic materials or wet-coated organic materials have some limitations. In this work, we develop a general and highly efficient dry-laminating encapsulation method to reduce the hysteresis of CNTTFTs, which may simultaneously realize the construction and encapsulation of CNTTFT. Furthermore, by virtue of dry procedure and wide compatibility of PMMA, this method is suitable for the construction of CNTTFT on diverse surface including both inorganic and organic dielectric materials. Significantly, the dry-encapsulated CNTTFT exhibits very low or even negligible hysteresis with good repeatability and air stability, which is greatly superior to the nonencapsulated and wet-encapsulated CNTTFT with spin-coated PMMA. The dry-laminating encapsulation strategy, a kind of technological innovation, resolves a significant problem of CNTTFT and therefore will be promising in facile transferring and packaging the CNT films for high-performance optoelectronic devices.

Synthesis of Al2O3\u2013SiO2\u2013MgO ceramics with hierarchical porous structure

A series of asymmetric cordierite ceramics with hierarchical porous structure were prepared and characterized. The macroporous support was obtained from natural raw materials (bauxite, silica sand, kaolinite, talc, and alumina) via ceramic technology. The prepared ceramic discs were characterized by a narrow pore size distribution. The average pore size was about 9.5 μm, and the open porosity was estimated to be 30%. Coating the discs with micro/mesoporous cordierite layer was performed using the sol–gel approach. Three-component sols were obtained from organic or inorganic precursors. Corresponding gels were calcined at 1200 °C to form the cordierite structure. The nature of precursor was found to affect the pore volume distribution. Narrow pore volume distribution was observed when organic precursors were used. Another key factor to control the parameters of final material was the drying condition. Supercritical drying of the gels has allowed us to increase the surface area in two orders of magnitude comparing with conventional drying procedure.