Highest DS Research Articles

Effect of the temperature and ultrasound on salt impregnation process of haddock

The influence of different brine temperatures (5, 15 and 25 °C) and ultrasound on the salt gain (SG) and water gain (WG) kinetics of haddock cubes during vacuum impregnation (VI) process was evaluated. Samples were taken from salt solution (4 g NaCl/ 100 g solution) after 0, 20, 40, 60, 100, 140 and 180 min of brining process for salt and moisture analysis. Ultrasound assisted VI and increasing temperature in the salt solution increased (P < 0.05) the salt content, and SG value in the haddock cubes. Furthermore, ultrasound assisted VI enhanced the water diffusion into the cubes and resulted in an increase in WG value. The ultrasound process increased the salt effective diffusion coefficient (Ds) and the highest Ds was found at 25 °C brine temperature. Azuara, Diffusive, Peleg, Weibull, Z and L models were tested to predicting SG and WG kinetics and Azuara was the best model during brining process of haddock cubes.

Synthesis of Polyanionic Cellulose Carbamates by Homogeneous Aminolysis in an Ionic Liquid/DMF Medium.

Polyanionic cellulose carbamates were synthesized by rapid and efficient homogeneous aminolysis of cellulose carbonate half-esters in an ionic liquid/DMF medium. Cellulose bis-2,3-O-(3,5-dimethylphenyl carbamate), as a model compound, reacted with different chloroformates to cellulose carbonates. These intermediates were subjected to aminolysis, for which both the reactivity of different chloroformates towards C6-OH and the reactivity/suitability of the respective carbonate half-ester in the aminolysis were comprehensively studied. Phenyl chloroformate and 4-chlorophenyl chloroformate readily reacted with C6-OH of the model cellulose derivative, while 4-nitrophenyl chloroformate did not. The intermediate 4-chlorophenyl carbonate derivative with the highest DS (1.05) was then used to evaluate different aminolysis pathways, applying three different amines (propargyl amine, β-alanine, and taurine) as reactants. The latter two zwitterionic compounds are only sparingly soluble in pure DMF as the typical reaction medium for aminolysis; therefore, several alternative procedures were suggested, carefully evaluated, and critically compared. Solubility problems with β-alanine and taurine were overcome by the binary solvent system DMF/[EMIM]OAc (1:1, v/v), which was shown to be a promising medium for rapid and efficient homogeneous aminolysis and for the preparation of the corresponding cellulose carbamate derivatives or other compounds that are not accessible by conventional isocyanate chemistry. The zwitterionic cellulose carbamate derivatives presented in this work could be promising chiral cation exchangers for HPLC enantiomer separations.

The effect of salinity stress on the amount of proline, chlorophyll and sodium and potassium ions in different rice cultivars in hydroponic environment

Introduction Among the cereals, rice is the most important human food source after wheat and has a major place in human nutrition in terms of production and cultivation. This plant is susceptible to salt stress and its response to salt stress varies with growth stages, concentration and duration of impact. Materials and methods This study was carried out in factorial experiment in a completely randomized design with three replications in the research greenhouse of Sari University of Agricultural Sciences and Natural Resources in 1977-98. The first factor was 71 rice genotypes and the second factor was salinity stress with 4 levels. The germinated seeds were transferred to hydroponic medium to prepare the culture medium from Yoshida nutrient solution (Yoshida et al., 1994). Chlorophyll extraction of rice leaf by Arnon method (1997), Proline amino acid extraction from leaf tissue by Bets et al. (1973) and for determination of sodium and potassium ions from leaf by Hamada and Elnai method (1994) used. The data obtained from these traits were analyzed by SAS and SPSS statistical software and compared by means of Duncan's multiple range test and clustering of genotypes by cluster analysis of tolerant cultivars based on this. Attributes were identified. Results and discussion Results of analysis of variance for different physiological traits under salinity stress showed that genotype, salinity and their interaction effects were statistically significant at the 5% probability level for all measured traits. Comparison of mean salinity levels in all measured traits was significant at 5% probability level. It showed that proline amino acid content and leaf tissue sodium content increased with increasing salinity and zero (normal) level with minimum and salinity level 9 The highest Ds was obtained and the chlorophyll pigment and potassium content of leaf tissue decreased with increasing salinity level and the highest (zero) level and the lowest salinity level was 9 dS / m. Within plant cells, proline acts as an osmotic preserving agent between the cytoplasm and the cell vacuole, and proline protects the plant against free radical damage. In the present experiment, proline content increased significantly with increasing salinity dose. This increase was higher in tolerant cultivars than in susceptible cultivars. An important effect of increasing salinity is leaf senescence and the main factor causing leaf senescence is the decrease in chlorophyll content under salinity stress. In this study, total chlorophyll a, chlorophyll a and chlorophyll b also decreased significantly under salinity stress, which was in line with the results of Bori Boncast et al. (2013) and (Wijita et al., 2018). Higher concentrations of potassium ions in the leaves of tolerant cultivars exposed to salinity can be a adaptive response to high potassium ion storage in stomach cells in salinity stress (Fallah 2015). Aerial is one of the mechanisms of plant tolerance against salinity stress. The results of this study are in line with the results of Hong et al. (2012).Conclusions The results of this study showed that salinity stress significantly decreased chlorophyll pigment and leaf potassium ion content and significantly increased proline amino acid and sodium ion content of leaf. Mean comparison between cultivars under salinity stress showed that Shastak Mohammadi, Nemat, Tarom Ghali, GASMAL, Neda, Roshan, NONABOKRA, FL478, Dilmani and Barley at 9 dS m-1 were the most tolerant cultivars to salinity and salinity stress. Saleh, Rashti Cold, IRBLZFU, IR39595, IR29, Black tip and Dorfak at 9 dSm-1 were the most susceptible cultivars to salinity stress. Acknowledgements Thanks to Sari University of Agriculture and Natural Resources and the Genetics and Plant Breeding Laboratory for providing some of the cost of this research as well as for providing plant specimens.

Atributos químicos e físicos do solo cultivado com forrageiras invernais e soja em sucessão

Muitos produtores resistem em adotar a presença dos animais nas lavouras, pois acreditam que possa compactar o solo e causar redução na produtividade da cultura em sucessão. Diante disso, objetivou-se avaliar os atributos químicos e físicos do solo após o cultivo de forrageiras invernais sob manejos de pastejo e soja em sucessão em sistema de integração lavoura-pecuária. O experimento foi conduzido em um LATOSSOLO VERMELHO sob o delineamento de blocos ao acaso, em esquema de faixas, com três repetições. Foram testados diferentes forrageiras invernais (aveia BRS 139, aveia preta IPR 61, aveia branca IPR Esmeralda, Triticale 111 Tpolo e o consórcio de Triticale 111 TPolo e aveia IPR Esmeralda), manejos de pastejo (sem pastejo, um pastejo e dois pastejos) e profundidades do solo (0-0,05, 0,05-0,10 e 0,10-0,20 m). Foram determinados os seguintes atributos: nitrogênio total (NT), carbono orgânico total (COT), relação carbono e nitrogênio (C/N), matéria orgânica do solo (MOS), porosidade total (Pt), macroporosidade (Mac), microporosidade (Mic) e densidade aparente (Ds). As forrageiras utilizadas para pastejo no período de inverno resultaram em diferentes teores de MOS, NT e Mac. O cultivo do Triticale 111 TPolo resultou em menor Mic e Pt quando manejado sob dois pastejos nas camadas de 0,05-0,10 e 0,10-0,20 m e a maior Ds foi encontrada na camada superficial, independentemente da forrageira e manejo. As forrageiras invernais quando submetidas a pressões de pastejo não modificaram os atributos do solo entre as profundidades avaliadas.

Preparation and Characterization of Surface-Modified Nanocellulose Fibers for Water-Based Coating Application

Nanocellulose fibers (NCF) is a renewable biodegradable polymer in nature. It has extensively interest as a reinforcement material in nanocomposites due to its nanoscale advantages. However, the efficiency of NCF dispersion in polymer matrix has limitation due to its self-agglomeration.The objective of this research was to prepare surface-modified NCF using three different acids; succinic anhydride, phthalic anhydride and citric acid. The molar ratios of acid to anhydroglucose units in NCF used in this work were 6:1, 8:1 and 10:1. The effects of acid types and molar ratios toward physical properties were studied. The results showed that succinic anhydride-modified NCF provided the highest DS range from 0.46-0.86. Dispersion of succinic anhydride-modified NCF provided good stability in water for 30 days. The succinic anhydride-modified NCF of 1:6 molar ratio is suitable for emulsion coating application.

Analisis Kinerja Simpang Bersinyal di Simpang Papar Untuk Perencanaan Jalan Tol Kertosono-Kediri

The Papar intersection is a very congested route because the location is in the Kertosono-Kediri toll road planning area for the economic distribution of the Western and Southern East Java Provinces. There needs to be a traffic engineering management so that the intersection is not increasingly saturated. As a benchmark is the forecasting of traffic performance carried out for 2 years from 2019 to 2021. The intersection of the Simpang Papar due to the construction of the Kertosono-Kediri toll road will decrease the value of the DS by developing the Kertosono-Kediri toll road so that the DS value is below 1 (one). The lowest 2021 DS is 0.17, while the highest DS is 0.46. Based on the results of forecasting, the intersection of Papar after the construction of the Kertosono - Kediri toll road has increased the volume of traffic along with the growth in vehicle numbers. The lowest 2045 DS year is 0.94, while the highest DS is 2.51. The solution to dealing with traffic congestion in the year 2045 is by traffic monitoring, especially the signal settings and vehicle restrictions. Keywords— traffic performance, degree of saturation, signal intersection, toll planning

Analisis Kinerja Simpang Tak Bersinyal di Simpang Mengkreng Untuk Perencanaan Jalan Tol Kertosono – Kediri

The mengkreng intersection is a very congested route because its location is near Nganjuk, Kediri and Jombang Regencies for the economic distribution of the West and East Java Provinces. Traffic engineering management is needed so that the intersection is not increasingly saturated. As a benchmark, traffic performance forecasting is carried out for 3 years from 2019 to 2022. Based on forecasting results, the Mengkreng intersection will decrease its DS value by carrying out the Kertosono - Kediri toll road development plan so that the DS value is below 1 (one). In 2019 the lowest DS was 0.79, while the highest DS was 1.61. While in 2022 the lowest DS is 0.45, while the highest DS is 2.72. The solution to deal with traffic congestion in 2045 is through traffic engineering and vehicle restrictions.

Kajian Analisis Lalulintas Simpang Bersinyal di By Pass Krian Untuk Perencanaan Pelebaran Jalan dan Fly Over

Krian Bypass intersection is a very crowded route because of its location near Sidoarjo and Mojokerto Regencies for the economic distribution of Surabaya City. There needs to be phase regulation, road widening or fly over so that the intersection traffic volume is not getting saturated. As a benchmark is the forecasting of traffic performance carried out for 3 years from 2018 to 2021. Based on the results of forecasting, the Krian Bypass intersection will decrease its DS value by widening the road so that the green time cycle will be low and turn right impact the DS value below 1 (one). The lowest 2018 DS is 1.61, while the highest DS is 2.49. While the lowest year 2021 DS is 2.72, while the highest DS is 4.85. For the solution with the right turn phase for each intersection to the north DS = 1.02, U-RT = 0.82, S = 1.38, S-RT = 0.69, T = 1.24, T-RT = 0.78, B = 1.79, B-RT = 0.04 . The solution for forecasting the flow of Krian Bypass in 2021. The calculation results made with effective width engineering, turn right and green time can reduce the DS value (Degree of Saturation) still shows DS value&gt; 0.75 - 1, then fly over is constructed with a scenario of 20% vehicles through existing and 80% of vehicles through fly over. Year 2021 The impact of fly over shows North DS = 0.4, South = 0.51, East = 0.56, and West = 0.45

Testing zinc chloride as a new catalyst for direct synthesis of cellulose di- and tri-acetate in a solvent free system under microwave irradiation

This research demonstrates the effect of ZnCl2 as a catalyst on the esterification of commercial cotton cellulose using acetic anhydride in order to obtain di- and tri-cellulose acetates under microwave irradiation. It was discovered that microwave irradiation significantly increased the yield and reduced the reaction time. It was found that the maximum yield for cellulose triacetates was 95.83% under the reaction conditions that were as follows: 3min reaction time, 200mg of ZnCl2 catalyst and 20ml of Ac2O for 5g cellulose. However, the cellulose acetate obtained in this manner had the highest DS (2.87). The cellulose di-acetate was produced with the maximum yield of 89.97% and with the highest DS (2.69) using 25ml Ac2O, 200mg of ZnCl2 for 5g cellulose and in 3min reaction time. The effect of some factors such as the amount of used catalyst, the quantity of acetic acid anhydride and the reaction time of the esterification process have been investigated. The production of di- and tri-cellulose acetate and the degree of substitution were confirmed using Fourier-transform infrared (FTIR) and nuclear magnetic resonance (NMR). The thermal stability was investigated using thermo gravimetric analysis (TGA), differential thermal analysis (DTA) and differential scanning calorimetry (DSC). The molecular weight and the degree of polymerization were obtained using Gel Permeation Chromatography (GPC). The analysis confirmed the successful synthesis of di- and tri-cellulose acetate without degradation during the reaction; these results were found to be in contrast to some recent studies. The present study reveals that ZnCl2 is a new catalyst; it is effective as well as inexpensive and is a low toxicity catalyst for usage in cellulose esterification.

Microwave-assisted carboxymethylation of cellulose extracted from brewer's spent grain

Cellulose was extracted from brewer's spent grain (BSG) by alkaline and bleaching treatments. The extracted cellulose was used in the preparation of carboxymethyl cellulose (CMC) by reaction with monochloroacetic acid in alkaline medium with the use of a microwave reactor. A full-factorial 23 central composite design was applied in order to evaluate how parameters of carboxymethylation process such as reaction time, amount of monochloroacetic acid and reaction temperature affect the average degree of substitution (DS¯) of the cellulose derivative. An optimization strategy based on response surface methodology has been used for this process. The optimized conditions to yield CMC with the highest DS¯ of 1.46 follow: 5g of monochloroacetic acid per gram of cellulose, reaction time of 7.5min and temperature of 70°C. This work demonstrated the feasibility of a fast and efficient microwave-assisted method to synthesize carboxymethyl cellulose from cellulose isolated of brewer's spent grain.

Homogeneous tritylation of cellulose in 1-allyl-3-methylimidazolium chloride and subsequent acetylation: the influence of base.

Homogeneous tritylation of cellulose in 1-allyl-3-methylimidazolium chloride (AmimCl) ionic liquid with triphenylmethy chloride as regents, pyridine or 1-butylimidazole (BIM) as base was investigated, and subsequent acetylation of the 6-O-functionalized products was further studied. The structure of products was analyzed by FTIR and (13)C NMR spectroscopy and base influences on the structure were discussed as well. The solution with pyridine as base underwent heterogeneous-homogeneous-heterogeneous process and the obtained trityl cellulose (TC) had organized structure with trityl group located completely at C-6 position of cellulose with maximum DS(trityl) of nearly 1. In the case of BIM as base, the solution was homogeneous for the whole reaction, but the highest DS(trityl) was about 0.22, with trityl group located not only at position 6 but also partially at position 2. Subsequent acetylation of the TC led to products with a preferred functionalization of the unprotected secondary OH-groups.

Polymer Electrolyte Membrane Based on Sulfonated Poly(Ether Ketone Ether Sulfone) (S-PEKES) with Low Methanol Permeability for Direct Methanol Fuel Cell Application

Poly(ether ketone ether sulfone), (PEKES), was synthesized by the nucleophilic aromatic substitution polycondensation between bisphenol S and 4,4′-difluorobenzophenone (system A), and between bisphenol S and 4,4′-dichlorobenzophenone (system B). The oxidative stability was characterized by using a Fenton's reagent. S-PEKES membranes show a higher thermal stability than that of Nafion 117 and comparable to that of S-PEEK 150XF. The proton conductivity values of S-PEKES of the highest DS are comparable to those of Nafion 117 and S-PEEK. The methanol permeability of the synthesized and fabricated S-PEKES membrane is lower than that of Nafion 117 by at least an order of magnitude.

Oil-in-water emulsion films stabilized by polymeric surfactants based on inulin with different degree of hydrophobic modification

Oil-in-water emulsion films stabilized by hydrophobically modified inulin polymeric surfactants with different degree of substitution, DS, of alkyl chains on the inulin backbone, were studied. Four different graft co-polymers with increasing DS were used. Equivalent film thickness, h w, and disjoining pressure, Π, were measured at different NaCl concentrations and 2 × 10 −5 mol dm −3 concentration of polymers. At a constant capillary pressure of about 36 Pa h w decreases with increase of NaCl concentration till a critical concentration, C el,cr, of 5 × 10 −2 mol dm −3 is reached above which the thickness remains constant indicating a transition from electrostatic to steric stabilization. For the four polymeric surfactants this dependence was virtually the same except for the polymer with the highest DS where above C el,cr a jump in the thickness to a Newton Black Film (NBF) was observed. For a wide range of NaCl concentrations (up to 2 mol dm −3) the measured disjoining pressure isotherms, Π vs. h w, showed in all cases a jump to NBF at a critical film thickness and critical disjoining pressure, which again indicates a transition from electrostatic to steric stabilization. This transition occurred at lower film thickness and lower capillary pressure as the DS was increased. A reduction in disjoining pressure at the transition point occurs with increase of degree of substitution. The results were discussed in relation to loop-size induced changes in steric repulsion.

N‐alkylation of chitosan by β‐halopropionic acids in the presence of various acceptors

AbstractN‐carboxyethylation of chitosan by β‐halopropionic acids in the presence of various proton and halogen ion acceptors was investigated. It has been observed that carboxyethylation of chitosan in aqueous medium is accompanied by the by‐processes of hydrolysis and dehydrohalogenation of the β‐halopropionic acids yielding β‐hydroxypropionic acid, bis(2‐carboxyethyl) ether, and acrylic acid. Degree of carboxyethyl substitution (DS) of chitosan and the relative rates of the by‐processes varied significantly depending on the conditions used and nature of the proton or halogen ion acceptor. At carboxyethylation of chitosan with the alkaline β‐bromopropionates, the DS increased in the order Cs+ &lt; Rb+ &lt; K+ ∼ Na+ &lt; Li+. For alkaline earth salts BrCH2CH2COOM0.5 (M = Be2+, Mg2+, Ca2+, Sr2+, Ba2+), the highest DS was obtained with strontium and barium salts, which could be subsequently removed from the reaction mixture by precipitation as sulfates. Among the organic bases applied (tetrabutylammonium hydroxide, triethylamine, trimethylamine, pyridine, 4‐N,N‐dimethylaminopyridine, 2,6‐lutidine, and 1,5‐diazabicyclo[4.3.0] non‐5‐ene), the highest DS was obtained using a moderately strong base triethylamine. For the halogen acceptors (Pb2+, Ag+, Tl+), the stoichiometrically highest DS was achieved in a system comprising iodopropionic acid plus Tl+ and a comparable conversion rate was obtained using also a combination of chloropropionic acid and Ag+. A novel alternative preparative approach—gel‐state synthesis—was suggested that provides for the highest DS at the optimum reaction conditions. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008

CreA-mediated carbon catabolite repression of β-galactosidase formation inAspergillus nidulansis growth rate dependent

Carbon catabolite repression by the CreA-transcriptional repressor is widespread in filamentous fungi, but the mechanism by which glucose triggers carbon catabolite repression is still poorly understood. We investigated the hypothesis that the growth rate on glucose may control CreA-dependent carbon catabolite repression by using glucose-limited chemostat cultures and the intracellular β-galactosidase activity of Aspergillus nidulans, which is repressed by glucose, as a model system. Chemostat cultures at four different dilution rates (D=0.095, 0.068, 0.045 and 0.015 h−1) showed that formation of β-galactosidase activity is repressed at the two highest Ds, but increasingly derepressed at the lower Ds, the activity at 0.015 h−1 equalling that in derepressed batch cultures. Chemostat cultures with the carbon catabolite derepressed A. nidulans mutant strain creAΔ4 revealed a dilution-rate independent constant β-galactosidase activity of the same range as that found in the wild-type strain at D=0.015 h−1. Two other enzymes – isocitrate lyase, which is almost absent on glucose due to a CreA-independent mechanism; and galactokinase, which is formed constitutively and independent of CreA – were measured as controls. They were formed at constant activity at each dilution rate, both in the wild-type strain as well as in the carbon catabolite derepressed mutant strain. We conclude that the growth rate on glucose is a determinant of carbon catabolite repression in A. nidulans, and that below a certain growth rate carbon catabolite derepression occurs.

CreA-mediated carbon catabolite repression of β-galactosidase formation in Aspergillus nidulans is growth rate dependent

Carbon catabolite repression by the CreA-transcriptional repressor is widespread in filamentous fungi, but the mechanism by which glucose triggers carbon catabolite repression is still poorly understood. We investigated the hypothesis that the growth rate on glucose may control CreA-dependent carbon catabolite repression by using glucose-limited chemostat cultures and the intracellular β-galactosidase activity of Aspergillus nidulans, which is repressed by glucose, as a model system. Chemostat cultures at four different dilution rates (D=0.095, 0.068, 0.045 and 0.015 h−1) showed that formation of β-galactosidase activity is repressed at the two highest Ds, but increasingly derepressed at the lower Ds, the activity at 0.015 h−1 equalling that in derepressed batch cultures. Chemostat cultures with the carbon catabolite derepressed A. nidulans mutant strain creAΔ4 revealed a dilution-rate independent constant β-galactosidase activity of the same range as that found in the wild-type strain at D=0.015 h−1. Two other enzymes – isocitrate lyase, which is almost absent on glucose due to a CreA-independent mechanism; and galactokinase, which is formed constitutively and independent of CreA – were measured as controls. They were formed at constant activity at each dilution rate, both in the wild-type strain as well as in the carbon catabolite derepressed mutant strain. We conclude that the growth rate on glucose is a determinant of carbon catabolite repression in A. nidulans, and that below a certain growth rate carbon catabolite derepression occurs.

An experimental study on the carboxymethylation of granular potato starch in non-aqueous media

The optimal reaction conditions for the carboxymethylation of granular potato starch in mixtures of water and organic liquids were determined. The reaction was carried out with pellets of NaOH and sodium monochloro acetate (SMCA) powder as the carboxymethylation reagent. Different alcohols, from methyl alcohol up to the three isomers of butyl alcohol, and acetone were compared in terms of the degree of substitution, DS, and the reaction efficiency, RE. Gelatinisation of the starch granules was avoided at all times. For ethyl alcohol and isopropyl alcohol the effect of the water fraction was studied. The highest RE and the highest DS were obtained for isopropyl alcohol with 10wt% water. For this system the effect of the temperature, the NaOH to SMCA molar ratio and the theoretical DS was studied in detail. The DS obtained in a single reaction step was limited to about 1.3, with an RE of 0.6. The modification was also carried out in three consecutive steps; resulting in granular carboxymethyl potato starch with a DS of 2.2. The results for the DS and the RE, obtained in this work, are considerably higher than the values reported in the literature.