Water Dosage Research Articles

Evaluation of Dominant Parameters in Lipase Transesterification of Cottonseed Oil

Abstract. Eversa Transform was used as an enzymatic catalyst to transform glandless and crude (heavy pigment) cottonseed oils into biodiesel. The oils were reacted with methanol at a 6:1 molar ratio with modified amounts of water, lipase, and temperature. Reactions were conducted in the presence of lipase and water at doses of 2, 5, and 8 wt% and 1, 3, and 6 wt%, respectively. Product composition and conversion were determined using the gas chromatography method of ASTM D6584. Oxidative stability was determined following EN 15751. The conversion to fatty acid methyl esters averaged 98.5% across all samples. Temperature had the most significant effect on conversion (p < 0.0035). Lipase and water dosages did not affect conversion, while each had an effect with temperature that was significant across the difference between 3 and 1 wt% water content and between 8 and 5 wt% enzyme content between the two temperatures (p = 0.0018 and 0.0153), respectively. Induction periods (oxidative stability) of the glandless and crude cottonseed oils were significantly different, but there was no difference between the two oil conversions based on oil type. Keywords: Biodiesel, Cottonseed oil, Fatty acid methyl esters, Lipase, Oxidative stability, Transesterification.

Past and future of sustainable viticulture in Switzerland

Switzerland is a pioneer country in the development of integrated production (IP) and integrated pest management (IPM). The overall goal is sustainability at the ecological, economic and social level to produce high quality grapes. In 1993, the IP-IPM head-organisation VITISWISS was created. The starting points were the improvement of pest management by the biocontrol of spider mites and the control of grape berry moths by mating disruption and an optimal soil management, followed over the years by state-of-the-art sprayer calibration, development of disease forecasting models (AgroMeteo, VitiMeteo), leaf-area adapted dosage of plant protection products, enhanced biodiversity, water and cover crop management. The efforts and the results gained in a continuous education process by the growers are considerable, but not enough for consumers and politics concerned by the use of plant protection products. The absence of acaricides and insecticides as well as forecasting systems available on the internet (www.agrometeo.ch) for the control of downy and powdery mildew, represent the major progresses. Where mechanisation is possible, herbicides can progressively be replaced by mechanical technics, which is not possible in steep vineyards. The general irrational unscientific trend against “synthetic” plant protection products requests alternatives for the control of fungal diseases and for cover crop management under the vine rows to avoid excessive water-nitrogen competition particularly in the actual context of climate change.

External sulfate attack on compressed stabilized earth blocks

Cementitious materials can be damaged by external sulfate attack due to ingress of sulfate ions from external environment. This process causes loss of cohesion, increase in porosity, local expansion, spalling and cracking. The objectives of this work were to study the influence of the capillary absorption time and of the sulfate ions concentration on compressed stabilized earth blocks (CSEB) exposed to sulfate attack. The CSEB were submitted to cycles of capillary absorption of sodium sulfate solution and drying. Two sets of procedures were used to evaluate the wear of the samples. In the first set of procedures, the capillary absorption time was varied. In the second one, the sodium sulfate concentration was varied instead. The CSEB used had the same dosage of earth, cement and water and for each procedure 3 samples were tested. The masses were measured after taking the samples out of the solution and after a 2-week drying time, being that a cyclic process for each procedure. The room temperature and relative humidity allowed crystallization of thenardite and mirabilite. Granulometry, XRD, XRF and SEM tests were used to identify the materials. The results showed that capillary absorption time and sulfate concentration influences the wear of the CSEB.

Feasibility of using cellulose filaments as a viscosity modifying agent in self-consolidating concrete

Nanomodification of concrete represents one of the phenomenal leaps in concrete technology providing innovative tools for engineering cement composites with improved performance. In self-consolidating concrete (SCC), for instance, designing flowable–yet stable and robust–SCC mixtures requires an optimum balance between flowability and stability. This is conventionally achieved by optimizing the dosage of high range water reducing admixtures (HRWRA) indispensable for flowability, while increasing the binder content or introducing viscosity modifying agents (VMA) necessary for stability. This study shows how cellulose filaments (CF)–a new type of nanocellulose materials–can be used as a novel tool for rheology modification and strength enhancement in SCC. CF were incorporated at concentrations ranging from 0.05 to 0.30% per weight of binder in cement pastes and SCC. Rheological and mechanical properties of CF systems were compared to those of plain systems and systems incorporating a commercially available VMA of welan gum type. Results showed that CF serve as a VMA due to the buildup of flexible nanoscale CF networks. As such, a geometry-based percolation model showed that at a concentration of 0.12 wt.%, a network of percolating CF was formed. Beyond this CF content, the yield stress, the plastic viscosity, as well as the HRWRA demand exhibited a substantial increase. CF networks increased mixture viscosity–essential for stability–at low shear rates. On the other hand, at high shear rates, CF networks led to lower apparent viscosity essential for improving pumpability; owing to the streamlining of the flexible nanocellulose fibrils in the direction of flow, thereby imparting a shear thinning behavior. Furthermore, CF imparted improvement in mechanical performance of 12–26% in compression, splitting-tension, and flexure. Research outcomes are expected to contribute towards offering an alternative VMA with strength improvement potential while contributing towards the implementation of sustainable materials for concrete technology.

Phase diagrams of the MgSO4-Al2(SO4)3-(NH4)2SO4-H2O system at 25 and 55 °C and their application in mineral carbonation

A route for the indirect mineral carbonation of blast furnace slag using (NH4)2SO4 as a recyclable reagent has recently been proposed. The main challenges associated with this route are reducing its energy consumption and improving its cost-efficiency. In this process, the recycling of (NH4)2SO4 by evaporation of the carbonation liquor make up a large proportion of the total energy consumption. Thus, controlling the water dosage during leaching of the products of roasting the blast furnace slag with (NH4)2SO4, which are mainly various sulfates of Ca, Mg, Al, and NH4+, is of great importance. In this study, the solubilities of the quaternary MgSO4-Al2(SO4)3-(NH4)2SO4-H2O system were measured at 25 and 55 °C using the isothermal method. The resulting phase diagrams are instructive for determining the lowest liquid-to-solid ratio required for leaching and for recovery of the value-added byproduct, ammonium alum, from the leachate. The results show that the crystalline region of NH4Al(SO4)2·12H2O dominates in the phase diagrams, indicating that it is easily crystallized out and that the use of this route for the separation of aluminum as ammonium alum is feasible. The liquid-to-solid ratios for the leaching unit were calculated to be 4.55 and 1.97 mL/g at 25 and 55 °C, respectively. The liquid-to-solid ratio at 55 °C was reduced by 56.7% compared to the ratio at 25 °C.

Determining major factors controlling phosphorus removal by promising adsorbents used for lake restoration: A linear mixed model approach

Phosphorus (P) removal from lake/drainage waters by novel adsorbents may be affected by competitive substances naturally present in the aqueous media. Up to date, the effect of interfering substances has been studied basically on simple matrices (single-factor effects) or by applying basic statistical approaches when using natural lake water. In this study, we determined major factors controlling P removal efficiency in 20 aquatic ecosystems in the southeast Spain by using linear mixed models (LMMs). Two non-magnetic -CFH-12® and Phoslock®- and two magnetic materials -hydrous lanthanum oxide loaded silica-coated magnetite (Fe-Si-La) and commercial zero-valent iron particles (FeHQ)- were tested to remove P at two adsorbent dosages. Results showed that the type of adsorbent, the adsorbent dosage and color of water (indicative of humic substances) are major factors controlling P removal efficiency. Differences in physico-chemical properties (i.e. surface charge or specific surface), composition and structure explain differences in maximum P adsorption capacity and performance of the adsorbents when competitive ions are present. The highest P removal efficiency, independently on whether the adsorbent dosage was low or high, were 85–100% for Phoslock and CFH-12®, 70–100% for Fe-Si-La and 0–15% for FeHQ. The low dosage of FeHQ, compared to previous studies, explained its low P removal efficiency. Although non-magnetic materials were the most efficient, magnetic adsorbents (especially Fe-Si-La) could be proposed for P removal as they can be recovered along with P and be reused, potentially making them more profitable in a long-term period.

A procedure for characterizing the curing process of cold recycled bitumen emulsion mixtures

Due to the presence of water, emulsion and cement, cold recycled mixtures (CRM) are evolutive materials and thus require a certain curing time to develop their long-term properties. The present study describes a laboratory approach for characterizing the properties of CRM, focusing on their evolutive behaviour. The experimental activities were carried out in parallel at the École de technologie supérieure (ÉTS) in Montréal, Canada and at the Università Politecnica delle Marche in Ancona (UNIVPM), Italy. The evolution of water loss by evaporation and indirect tensile strength (ITS) was measured and analyzed using the Michalis-Menten model, in order to achieve a quantitative characterization of the curing process. The results showed that different dosages of water resulted in different rates of water loss by evaporation, but did not penalize the development of ITS. Moreover, for both CRM, a good correlation was found between water loss and ITS. Finally, the data showed that after 28 days of curing in the selected laboratory conditions, the evaporation process was virtually completed.

Improved process to prepare high-purity anhydrous potassium fluoride from wet process phosphoric acid

ABSTRACTThe production of potassium fluoride (KF) through recovering fluorine from wet process phosphoric acid (WPA) is very attractive as it not only makes a profitable use of the fluorine resource but also purifies WPA to some extent. The current route to prepare KF from WPA was assessed and significantly improved. Both the purity and yield of the KF product are increased with the upgraded process. Key improvements include (1) the recovery of the KF wrapped in the silicon dioxide filter cake with controlled amount of water and (2) the removal of unreacted KOH and meta aluminate impurities in the KF mother liquor with controlled amount of fluosilicic acid solution. The suitable dosage of the wash water and fluosilicic acid solution were recommended, which can be practically controlled by measuring the density and pH of KF mother liquor, respectively. Repeated experiments have verified that the improved process, compared to the current one, successfully increases the purity of KF product from 96 to 99% and the yield from 78 to 93%.

Improving cellulose nanofibrillation of waste wheat straw using the combined methods of prewashing, p-toluenesulfonic acid hydrolysis, disk grinding, and endoglucanase post-treatment

Here we established a new approach for improving the cellulose nanofibrillation of high ash content waste wheat straw (WWS). The results were comprehensively elucidated from the ash removal, delignification, mechanical fibrillation and endoglucanase post-treatment. When water dosage was increased from 50 to 500 times of the WWS weight, the ash content gradually decreased during prewashing process, which facilitated lignin solubilization in subsequent p-toluenesulfonic acid (p-TsOH) hydrolysis. Approximately 80% of lignin in prewashed WWS could be dissolved during acid hydrolysis to result in a relatively higher crystallinity of 59.1%. Compared with the lignocellulosic nanofibrils (LCNF) directly obtained using acid hydrolysis and disk grinding, prewashing-assisted acid hydrolyzed WWS was fibrillated into LCNF with smaller height of 57.0 nm. Mild endoglucanase post-treatment could further produce less entangled LCNF with thinner diameters. In short, this study presented a promising and green pathway to achieve an efficient utilization of agricultural residue wastes to cellulose nanomaterials.

Comparison of ANN and RKS approaches to model SCC strength

Self compacting concrete (SCC) is a high performance concrete that has high flowability and can be used in heavily reinforced concrete members with minimal compaction segregation and bleeding. The mix proportioning of SCC is highly complex and large number of trials are required to get the mix with the desired properties resulting in the wastage of materials and time. The research on SCC has been highly empirical and no theoretical relationships have been developed between the mixture proportioning and engineering properties of SCC. In this work effectiveness of artificial neural network (ANN) and random kitchen sink algorithm(RKS) with regularized least square algorithm(RLS) in predicting the split tensile strength of the SCC is analysed. Random kitchen sink algorithm is used for mapping data to higher dimension and classification of this data is done using Regularized least square algorithm. The training and testing data for the algorithm was obtained experimentally using standard test procedures and materials available. Total of 40 trials were done which were used as the training and testing data. Trials were performed by varying the amount of fine aggregate, coarse aggregate, dosage and type of super plasticizer and water. Prediction accuracy of the ANN and RKS model is checked by comparing the RMSE value of both ANN and RKS. Analysis shows that eventhough the RKS model is good for large data set, its prediction accuracy is as good as conventional prediction method like ANN so the split tensile strength model developed by RKS can be used in industries for the proportioning of SCC with tailor made property.

Lipase-catalyzed synthesis of biodiesel in a hydroxyl-functionalized ionic liquid

In this work, the biodiesel production from soybean oil catalyzed by lipase in a hydroxyl-functionalized ionic liquid (IL), N-methyl-N-propanolpyrrolidinium bis(trifluoromethanesulphonyl)imide ([C1C3OHPyr]NTf2), was investigated. Compared with the conventional solvents (n-hexane and tert-butanol) and the dialkyl-based ILs, the use of [C1C3OHPyr]NTf2 as the reaction medium significantly improved the biodiesel yield. The biodiesel yield was greatly affected by the dosages of IL, water and enzyme, the reaction time, temperature and the methanol/oil molar ratio. The IL phase and the enzyme could be recycled by washing with water and acetone respectively at the end of reaction. The catalytic performance of the recovered lipase decreased due to the blocking of lipase active sites by impurities, nevertheless, high biodiesel yield could be obtained for the recovered lipase via prolonging the reaction time from 2h to 6h.

Biochar improves maize growth by alleviation of nutrient stress in a moderately acidic low-input Nepalese soil

We studied the role of biochar in improving soil fertility for maize production. The effects of biochar on the alleviation of three potential physical-chemical soil limitations for maize growth were investigated, i.e. water stress, nutrient stress and acid stress. Experiments involved soils with two dosages of biochar (0.5% and 2% w:w), as well as ones without biochar, in combination with four different dosages of NPK fertilizer, water and lime. Biochar was produced from the invasive shrubby weed Eupatorium adenophorum using flame curtain kilns. This is the first study to alleviate one by one the water stress, nutrient stress and acid stress in order to investigate the mechanisms of biochar effects on soil fertility.Biochar addition increased soil moisture, potassium (K) and plant available phosphorous (P-AL), which all showed significant positive relationship (p<0.001) with above ground biomass of maize. However, biochar was much more effective at abundant soil watering (+311% biomass) than at water-starved conditions (+67% biomass), indicating that biochar did increase soil moisture, but that this was not the main reason for the positive biomass growth effects. Biochar addition did have a stronger effect under nutrient-stressed conditions (+363%) than under abundant nutrient application (+132%). Biochar amendment increased soil pH, but liming and pH had no effect on maize dry biomass, so acidity stress alleviation was not the mechanism of biochar effects on soil fertility.In conclusion, the alleviation of nutrient stress was the probably the main factor contributing to the increased maize biomass production upon biochar addition to this moderately acidic Inceptisol.

Magnetized Water Effect on Compressive Strength and Dosage of Superplasticizers and Water in Self-Compacting Concrete

AbstractThe use of self-compacting concrete (SCC) has been established; however, novel methods for optimizing and providing suitable workability are still developing. The effect of magnetized water...

High-throughput lipidomics reveal mirabilite regulating lipid metabolism as anticancer therapeutics.

Altered lipid metabolism is an emerging hallmark of cancers. Mirabilite has a therapeutic effect on colorectal cancer (CRC); however, its metabolic mechanism remains unclear. This study aims to explore the potential therapeutic targets of mirabilite protection against colorectal cancer in APCmin/+ mice model. Oral administration of mirabilite was started from the ninth month, while the same dosage of distilled water was given to both the control group and the model group. Based on lipidomics, we collected serum samples of all mice at the 20th week and used a non-targeted method to identify the lipid biomarkers of CRC. Compared with C57BL/6J mice, the metabolic profile of CRC model mice was significantly disturbed, and we identified that 25 lipid-related biomarkers, including linoleic acid, 2-hydroxybutyric acid, 6-deoxocastasterone, hypoxanthine, PC(16:1), PC(18:4), and retinyl acetate, were associated with CRC. According to the abovementioned results, there were six lipid molecules with significant differences that can be used as new targets for handling of CRC through six metabolic pathways, namely, linoleic acid metabolism, retinol metabolism, propanoate metabolism, arachidonic acid metabolism, biosynthesis of unsaturated fatty acids and purine metabolism. Compared with the model group, the metabolic profiles of these disorders tend to recover after treatment. These results indicated that the lipid molecules associated with CRC were regulated by mirabilite. In addition, we identified seven key lipid molecules, of which four had statistical significance. After administration of mirabilite, all disordered metabolic pathways showed different degrees of regulation. In conclusion, high-throughput lipidomics approach revealed mirabilite regulating the altered lipid metabolism as anticancer therapeutics.

Nanopesticides: A recent novel ecofriendly approach in insect pest management

Nanotechnology, a promising field of interdisciplinary research opens up a wide array of opportunities. Large surface areas of the nanoparticles are responsible for their different chemical, optical, mechanical, magnetic properties as compared to large sized bulk materials. It gives major impulses to technical innovations in a variety of industrial sectors in the future which include enhancement in agricultural productivity involving efficient dosage of water and fertilizer, nanocapsules for biocides delivery, vector and pest management and nanosensors for pest detection. Traditional approaches like integrated pest management used in agriculture are insufficient and indiscriminate application of chemical pesticides have adverse effects on environment, animals and human beings. Therefore, nanotechnology provides proficient alternatives for the management of insect pests in agriculture without harming the nature and would offer green.

Long term mechanical properties of alkali activated slag

This article reports a study on the microstructural and long-term mechanical properties of the alkali activated slag up to 180 days, and cement paste is studied as the comparison. The mechanical properties including compressive strength, flexural strength, axis tensile strength and splitting tensile strength are analyzed. The results showed that the alkali activated slag had higher compressive and tensile strength, Slag is activated by potassium silicate (K2SiO3) and sodium hydroxide (NaOH) solutions for attaining silicate modulus of 1 using 12 potassium silicate and 5.35% sodium hydroxide. The volume dosage of water is 35% and 42%. The results indicate that alkali activated slag is a kind of rapid hardening and early strength cementitious material with excellent long-term mechanical properties. Single row of holes block compressive strength, single-hole block compressive strength and standard solid brick compressive strength basically meet engineering requirements. The microstructures of alkali activated slag are studied by X-ray diffraction (XRD). The hydration products of alkali-activated slag are assured as hydrated calcium silicate and hydrated calcium aluminate.

Modelling fresh properties of self-compacting concrete using Neural network technique

The purpose of this paper is to investigate the feasibility of using artificial neural network programming for the prediction of the fresh properties of self-compacting concrete. The input parameters of the neural network were the mix composition influencing the fresh properties of self-compacting concrete namely, the cement content, the dosages of limestone powder and water, fine aggregate, coarse aggregate, and superplasticizer, and other parameter of time of testing (5, 30 and 60 minutes after addition of water). The model is based on a multilayer feed forward neural network. The details of the proposed ANN with its architecture, training and validation are presented in this paper. Six outputs of the ANN models related to the fresh properties were the slump flow, T50, T60, V-funnel flow time, Orimet flow time, and blocking ratio (L-box). The effectiveness of the trained ANN is evaluated by comparing its responses with the experimental data that were used in the training process. The dosage of water was varied from 188 to 208 L/m3, the dosage of SP from 3.8 to 5.8 kg/m3, and the volume of coarse aggregates from 220 to 360 L/m3 (587 to 961 kg/m3). In total twenty mixes were used to measure the fresh properties with different mix compositions. ANN performed well and provided very good correlation coefficients (R2) above 0.957 for slump flow, T50, V-funnel flow time, Orimet flow time, and L-box blocking ratio. The predicting results for T60 was slightly lower (R2=0.823). With the calculated models these properties of new mixes within the practical range of the input variables used in the training can be predicted with an absolute error for slump flow, T50, T60, V-funnel flow time, Orimet flow time, and L-box ratio of 3.3%, 13%, 16%, 14%, 15%, and 22%, respectively. The results show that the ANN model can predict accurately the fresh properties of SCC.

Optimization of degumming parameters in chemical refining process to reduce phosphorus contents in kenaf seed oil

Abstract The degumming process for kenaf seed oil was investigated in this study, and parameters were optimized using response surface methodology with central composite design. The effects of three parameters, specifically temperature (25–85 °C), phosphoric acid dosage (0–0.2% w/w) and water dosage (0–40% w/w), on the phosphorus content in degummed oil were examined. A well-fitting model (R2 = 0.9850) with the probability value less than 0.0001 was successfully generated for the degumming process through multiple linear regressions with backward elimination. The optimal processing conditions in the degumming process for kenaf seed oil were determined to be a temperature of 40 °C, a phosphoric acid dosage of 0.09% w/w and a water dosage of 22.4% w/w, which resulted in a phosphorus content of 6.70 mg/kg. There were no significant differences (p > 0.05) between the experimental values and the predicted values, which demonstrated the adequacy of the fitted model. The degumming process removed 85.9% of the phosphorus content from crude kenaf seed oil. Response surface methodology was useful to optimize and study the interaction effects of the parameters in the degumming process for crude kenaf seed oil.

AERATED CONCRETE MICROWAVE REFLECTION AND TRANSMISSION PROPERTIES IN A WET ENVIRONMENT

Excess water content within the building material could greatly alter the interaction of the microwave with the material. In this study aerated concrete (AEROC) block walls (60x60cm) were investigated for their microwave (2.4 GHz) properties under wetting conditions. The spray wetting of the wall was conducted to simulate the environmental processes such as raining or water damage. 50ml/m² water dosage was applied on the surface of the concrete 21 times in 1 min intervals. The results show a noticeable decrease in microwave penetration power through the material after the sample gets enriched with water. As the water content on the surface of the material rises, so does the transmission loss. During the different water content of the aerated concrete, the reflection loss varied from -15.04 dB (dry wall) to -5.03 dB (wet wall’s surface). The transmission loss continues to rise during the entire length of the experiment, from -4.5 dB as a dry sample to -8.3 dB after 441 ml (1035 ml/m² during 23 min) of sprayed water. The variation of reflected microwave power was approximately ten times, which is quite a significant indicator of alteration of microwave propagation. The results demonstrate wetting process as an considerable factor in assessing microwave propagation in near the sources, such as mobile phone base station antennas, industrial microwave heaters and ovens etc.

Hybrid Cements with Non Silicate Activators

Hybrid cements represent a relatively new type of binders which combines some of the advantages of Ordinary Portland Cement and an application of mineral admixtures and alkali activation. Hybrid cements form then blends containing a low portion of OPC and a high proportion of mineral additions (such as blast furnace flag, fly ash, metakaoline, ...). This paper discusses the properties of mortars based on carbonate based activators. Mixtures composed from Ordinary Portland Cement, ground granulated blast furnace slag, fly ash and mechanically pre-activated fly ash were optimised with the target to achieve sufficient compressive strength. The influence of ratios between powder compounds, the dosage of activator and water to binder ratios are presented.