Search results for: nitrogen and gibberellic acid
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 4176

Search results for: nitrogen and gibberellic acid

3996 Anticataract Activity of Betulinic Acid in Chick Embryo Lens Model

Authors: Surendra Bodakhe

Abstract:

In this investigation, anticataract activity was determined using cataract formation in developing chick embryo by hydrocortisone. Lenses were evaluated firstly for the extent of opacity and secondly, for lens glutathione (GSH) levels. Betulinic acid was isolated from the chloroform fraction of the crude ethanolic extract of Bauhinia variegata bark (SBE). Fourteen days old Australorp fertilized eggs were divided into different groups of six eggs each. After 24 hrs incubation in a humidified incubator (37οC), at 15 days of age; hydrocortisone (0.25µM/0.2ml/egg) was administered to the chorioallantoic membrane of chick embryos through a small hole in the egg shell on the air sack. Ascorbic acid (standard) or Betulinic acid (test) were administered at 3, 10 and 20 hr after hydrocortisone administration at a specified dose. The puncture was sealed with a cellophane tape and eggs were incubated for 48 hrs in a humidified incubator at 37οC. After 48 hrs, the lenses were isolated for the determination of the extent of opacity and Glutathione level. The betulinic acid prevented the opacification of the chick embryo lenses induced by hydrocortisone. The betulinic acid also prevented the decline of GSH content caused by hydrocortisone. The results indicate that betulinic acid protect the cataract formation in chick embryo lenses induced by hydrocortisone.

Keywords: betulinic acid, cataract, cloudiness, ovine

Procedia PDF Downloads 321
3995 Evaluating Acid Buffering Capacity of Sewage Sludge Barrier for Inhibiting Remobilization of Heavy Metals in Tailing Impoundment

Authors: Huyuan Zhang, Yi Chen

Abstract:

Compacted sewage sludge has been proved to be feasible as a barrier material for tailing impoundment because of its low permeability and retardation of heavy metals. The long-term penetration of acid mine drainage, however, would acidify the barrier system and result in remobilization of previously immobilized heavy metal pollutants. In this study, the effect of decreasing pH on the mobility of three typical heavy metals (Zn, Pb, and Cu) is investigated by acid titration test on sewage sludge under various conditions. The remobilization of heavy metals is discussed based on the acid buffering capacity of sewage sludge-leachate system. Test results indicate that heavy metals are dramatically released out when pH is decreased below 6.2, and their amounts take the order of Zn > Cu > Pb. The acid buffering capacity of sewage sludge decreases with the solid-liquid ratio but increases with the anaerobic incubation time, and it is mainly governed by dissolution of contained carbonate and organics. These results reveal that the sewage sludge possesses enough acid buffering capacity to consume protons within the acid mine drainage. Thus, this study suggests that an explosive remobilization of heavy metals is not expected in a long-term perspective.

Keywords: acid buffering capacity, barrier, heavy metals, remobilization, sewage sludge

Procedia PDF Downloads 291
3994 Theoretical Study of the Mechanism of the Oxidation of Linoleic Acid by 1O2

Authors: Rayenne Djemil

Abstract:

The mechanism of oxidation reaction of linoleic acid C18: 2 (9 cis12) by singlet oxygen 1O2 were theoretically investigated via using quantum chemical methods. We explored the four reaction pathways at PM3, Hartree-Fock HF and, B3LYP functional associated with the base 6-31G (d) level. The results are in favor of the first and the last reaction ways. The transition states were found by QST3 method. Thus the pathways between the transition state structures and their corresponding minima have been identified by the IRC calculations. The thermodynamic study showed that the four ways of oxidation of linoleic acid are spontaneous, exothermic and, the enthalpy values confirm that conjugate hydroperoxydes are the most favorable products.

Keywords: echanism, quantum mechanics, oxidation, linoleic acid H

Procedia PDF Downloads 419
3993 The Thermochemical Conversion of Lactic Acid in Subcritical and Supercritical Water

Authors: Shyh-Ming Chern, Hung-Chi Tu

Abstract:

One way to utilize biomass is to thermochemically convert it into gases and chemicals. For conversion of biomass, glucose is a particularly popular model compound for cellulose, or more generally for biomass. The present study takes a different approach by employing lactic acid as the model compound for cellulose. Since lactic acid and glucose have identical elemental composition, they are expected to produce similar results as they go through the conversion process. In the current study, lactic acid was thermochemically converted to assess its reactivity and reaction mechanism in subcritical and supercritical water, by using a 16-ml autoclave reactor. The major operating parameters investigated include: The reaction temperature, from 673 to 873 K, the reaction pressure, 10 and 25 MPa, the dosage of oxidizing agent, 0 and 0.5 chemical oxygen demand, and the concentration of lactic acid in the feed, 0.5 and 1.0 M. Gaseous products from the conversion were generally found to be comparable to those derived from the conversion of glucose.

Keywords: lactic acid, subcritical water, supercritical water, thermochemical conversion

Procedia PDF Downloads 294
3992 Chloroform-Formic Acid Solvent Systems for Nanofibrous Polycaprolactone Webs

Authors: I. Yalcin Enis, J. Vojtech, T. Gok Sadikoglu

Abstract:

In this study, polycaprolactone (PCL) was dissolved in chloroform: ethanol solvent system at a concentration of 18 w/v %. 1, 2, 4, and 6 droplets of formic acid were added to the prepared 10ml PCL-chloroform:ethanol solutions separately. Fibrous webs were produced by electrospinning technique. Morphology of the webs was investigated by using scanning electron microscopy (SEM) whereas fiber diameters were measured by Image J Software System. The effect of formic acid addition to the mostly used chloroform solvent on fiber morphology was examined.

Keywords: chloroform, electrospinning, formic acid polycaprolactone, fiber

Procedia PDF Downloads 254
3991 Poly(Lactic Acid) Based Flexible Films

Authors: Fathilahbinti Ali, Jamarosliza Jamaluddin, Arun Kumar Upadhyay

Abstract:

Poly(lactic acid) (PLA) is a biodegradable polymer which has good mechanical properties, however, its brittleness limits its usage especially in packaging materials. Therefore, in this work, PLA based polyurethane films were prepared by synthesizing with different types of isocyanates; methylene diisocyanate (MDI) and hexamethylene diisocyanates (HDI). For this purpose, PLA based polyurethane must have good strength and flexibility. Therefore, polycaprolactone which has better flexibility were prepared with PLA. An effective way to endow polylactic acid with toughness is through chain-extension reaction of the polylactic acid pre-polymer with polycaprolactone used as chain extender. Polyurethane prepared from MDI showed brittle behaviour, while, polyurethane prepared from HDI showed flexibility at same concentrations.

Keywords: biodegradable polymer, flexible, poly(lactic acid), polyurethane

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3990 Simultaneous Nitrification and Denitrification in Suspended Activated Sludge Process Augmented with Immobilized Biomass: A Pilot Study

Authors: Haon-Yao Chen, Cheng-Fang Lin, Pui-Kwan Andy Hong, Ping-Yi Yang, Kok Kwang Ng, Sheng-Fu Yang

Abstract:

Simultaneous nitrification and denitrification (SND) are a natural phenomenon in the soil environment that can be applied in wastewater treatment. At a domestic wastewater treatment plant, we performed a pilot test of installing bioplates with entrapped biomass into a conventional aeration basin for SND, and investigated the effects of bioplate packing ratio, hydraulic retention time, dissolved oxygen level, on/off aeration mode, and supplemental carbon and alkalinity on nitrogen removal. With the pilot aeration basin of 1.3 m3 loaded with mixed liquor suspended solids of 1500-2500 mg/L and bioplates at PR of 3.2% (3.2% basin volume) operated at HRT of 6 h and DO of 4-6 mg/L without supplemental carbon or alkalinity, nitrogen in the wastewater was removed to an effluent total nitrogen (TN) of 7.3 mg/L from an influent TN of 28 mg/L. The bioplate robust cellulose triacetate structure carrying the biomass shows promise in retrofitting conventional aeration basins for enhanced nutrient removal.

Keywords: immobilization, nitrification/denitrification, nutrient removal, total nitrogen

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3989 Time-Course Lipid Accumulation and Transcript Analyses of Lipid Biosynthesis Gene of Chlorella sp.3 under Nitrogen Limited Condition

Authors: Jyoti Singh, Swati Dubey, Mukta Singh, R. P. Singh

Abstract:

The freshwater microalgae Chlorella sp. is alluring considerable interest as a source for biofuel production due to its fast growth rate and high lipid content. Under nitrogen limited conditions, they can accumulate significant amounts of lipids. Thus, it is important to gain insight into the molecular mechanism of their lipid metabolism. In this study under nitrogen limited conditions, regular pattern of growth characteristics lipid accumulation and gene expression analysis of key regulatory genes of lipid biosynthetic pathway were carried out in microalgae Chlorella sp 3. Our results indicated that under nitrogen limited conditions there is a significant increase in the lipid content and lipid productivity, achieving 44.21±2.64 % and 39.34±0.66 mg/l/d at the end of the cultivation, respectively. Time-course transcript patterns of lipid biosynthesis genes i.e. acetyl coA carboxylase (accD) and diacylglycerol acyltransferase (dgat) showed that during late log phase of microalgae Chlorella sp.3 both the genes were significantly up regulated as compared to early log phase. Moreover, the transcript level of the dgat gene is two-fold higher than the accD gene. The results suggested that both the genes responded sensitively to the nitrogen limited conditions during the late log stage, which proposed their close relevance to lipid biosynthesis. Further, this transcriptome data will be useful for engineering microalgae species by targeting these genes for genetic modification to improve microalgal biofuel quality and production.

Keywords: biofuel, gene, lipid, microalgae

Procedia PDF Downloads 279
3988 Application of Chemical Tests for the Inhibition of Scaling From Hamma Hard Waters

Authors: Samira Ghizellaoui, Manel Boumagoura

Abstract:

Calcium carbonate precipitation is a widespread problem, especially in hard water systems. The main water supply that supplies the city of Constantine with drinking water is underground water called Hamma water. This water has a very high hardness of around 590 mg/L CaCO₃. This leads to the formation of scale, consisting mainly of calcium carbonate, which can be responsible for the clogging of valves and the deterioration of equipment (water heaters, washing machines and encrustations in the pipes). Plant extracts used as scale inhibitors have attracted the attention of several researchers. In recent years, green inhibitors have attracted great interest because they are biodegradable, non-toxic and do not affect the environment. The aim of our work is to evaluate the effectiveness of a chemical antiscale treatment in the presence of three green inhibitors: gallicacid; quercetin; alginate, and three mixtures: (gallic acid-quercetin); (quercetin-alginate); (gallic acid-alginate). The results show that the inhibitory effect is manifested from an addition of 1mg/L of gallic acid, 10 mg/L of quercetin, 0.2 mg/L of alginate, 0.4mg/L of (gallic acid-quercetin), 2mg/L of (quercetin-alginate) and 0.4 mg/L of (gallic acid-alginate). On the other hand, 100 mg/L (Drinking water standard) of Ca2+is reached for partial softening at 4 mg/L of gallic acid, 40 mg/L of quercetin, 0.6mg/L of alginate, 4mg/L of (gallic acid-quercetin), 10mg/L of (quercetin-alginate) and 1.6 mg/L of (gallic acid-alginate).

Keywords: water, scaling, calcium carbonate, green inhibitor

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3987 Experimental Assessment of Artificial Flavors Production

Authors: M. Unis, S. Turky, A. Elalem, A. Meshrghi

Abstract:

The Esterification kinetics of acetic acid with isopropnol in the presence of sulfuric acid as a homogenous catalyst was studied with isothermal batch experiments at 60,70 and 80°C and at a different molar ratio of isopropnol to acetic acid. Investigation of kinetics of the reaction indicated that the low of molar ratio is favored for esterification reaction, this is due to the reaction is catalyzed by acid. The maximum conversion, approximately 60.6% was obtained at 80°C for molar ratio of 1:3 acid : alcohol. It was found that increasing temperature of the reaction, increases the rate constant and conversion at a certain mole ratio, that is due to the esterification is exothermic. The homogenous reaction has been described with simple power-law model. The chemical equilibrium combustion calculated from the kinetic model in agreement with the measured chemical equilibrium.

Keywords: artificial flavors, esterification, chemical equilibria, isothermal

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3986 Inhibitory Impacts of Fulvic Acid-Coated Iron Oxide Nano Particles on the Amyloid Fibril Aggregations

Authors: Dalia Jomehpour, Sara Sheikhlary, Esmaeil Heydari, Mohammad Hossien Majles Ara

Abstract:

In this study, we report fulvic acid-coated iron oxide nanoparticles of 10.7 ± 2.7 nm size, which serve to inhibit amyloid fibrillation formation. Although the effect of fulvic acid on tau fibrils was investigated, to our best knowledge, its inhibitory impacts on amyloid aggregation formation have been assessed neither in-vitro nor in-vivo. On the other hand, iron oxide nanoparticles exhibit anti-amyloid activity on their own. This study investigates the inhibitory effect of fulvic acid coated iron oxide nanoparticles on amyloid aggregations formed from the commonly used in-vitro model, lysozyme from chicken egg white. FESEM, XRD, and FTIR characterization confirmed that fulvic acid was coated onto the surface of the nanoparticles. The inhibitory effects of the fulvic acid coated iron oxide nanoparticles were verified by Thioflavin T assay, circular dichroism (CD), and FESEM analysis. Furthermore, the toxicity of the nanoparticles on the neuroblastoma SH-SY5Y human cell line was assessed through an MTT assay. Our results indicate that fulvic acid coated iron oxide nanoparticles can efficiently inhibit the formation of amyloid aggregations while exhibiting negligible in-vitro toxicity; thus, they can be used as anti-amyloid agents in the development of the potential drug for neurodegenerative diseases.

Keywords: Alzheimer’s disease, fulvic acid coated iron oxide nanoparticles, fulvic acid, amyloid inhibitor, polyphenols

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3985 Assessment of Escherichia coli along Nakibiso Stream in Mbale Municipality, Uganda

Authors: Abdul Walusansa

Abstract:

The aim of this study was to assess the level of microbial pollution along Nakibiso stream. The study was carried out in polluted waters of Nakibiso stream, originating from Mbale municipality and running through ADRA Estates to Namatala Wetlands in Eastern Uganda. Four sites along the stream were selected basing on the activities of their vicinity. A total of 120 samples were collected in sterile bottles from the four sampling locations of the stream during the wet and dry seasons of the year 2011. The samples were taken to the National water and Sewerage Cooperation Laboratory for Analysis. Membrane filter technique was used to test for Erischerichia coli. Nitrogen, Phosphorus, pH, dissolved oxygen, electrical conductivity, total suspended solids, turbidity and temperature were also measured. Results for Nitrogen and Phosphorus for sites; 1, 2, 3 and 4 were 1.8, 8.8, 7.7 and 13.8 NH4-N mg/L; and 1.8, 2.1, 1.8 and 2.3 PO4-P mg/L respectively. Basing on these results, it was estimated that farmers use 115 and 24 Kg/acre of Nitrogen and Phosphorus respectively per month. Taking results for Nitrogen, the same amount of Nutrients in artificial fertilizers would cost $ 88. This shows that reuse of wastewater has a potential in terms of nutrients. The results for E. coli for sites 1, 2, 3 and 4 were 1.1 X 107, 9.1 X 105, 7.4 X 105, and 3.4 X 105 respectively. E. coli hence decreased downstream with statistically significant variations between sites 1 and 4. Site 1 had the highest mean E.coli counts. The bacterial contamination was significantly higher during the dry season when more water was needed for irrigation. Although the water had the potential for reuse in farming, bacterial contamination during both seasons was higher than 103 FC/100ml recommended by WHO for unrestricted Agriculture.

Keywords: E. coli, nitrogen, phosphorus, water reuse, waste water

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3984 Esterification Reaction of Stearic Acid with Methanol Over Surface Functionalised PAN Fibrous Solid Acid Catalyst

Authors: Rawaz A. Ahmed, Katherine Huddersman

Abstract:

High-lipid Fats, Oils and Grease (FOGs) from wastewater are underutilized despite their potential for conversion into valuable fuels; this work describes a surface-functionalized fibrous Polyacrylonitrile (PAN) mesh as a novel heterogeneous acid catalyst for the conversion of free fatty acids (FFAs), via a catalytic esterification process into biodiesel. The esterification of stearic acid (SA) with methanol was studied over an acidified PAN solid acid catalyst. Disappearance of the carboxylic acid (C=O) peak of the stearic acid at 1696 cm-1 in the FT-IR spectrum with the associated appearance of the ester (C=O) peak at 1739 cm-1 confirmed the production of the methyl stearate. This was further supported by 1H NMR spectra with the appearance of the ester (-CH₂OCOR) at 3.60-3.70 ppm. Quantitate analysis by GC-FID showed the catalyst has excellent activity with >95 % yield of methyl stearate (MS) at 90 ◦C after 3 h and a molar ratio of methanol to SA of 35:1. To date, to our best knowledge, there is no research in the literature on the esterification reaction for biodiesel production using a modified PAN mesh as a catalyst. It is noteworthy that this acidified PAN mesh catalyst showed comparable activity to conventional Brönsted acids, namely H₂SO₄ and p-TSA, as well as exhibiting higher activity than various other heterogeneous catalysts such as zeolites, ion-exchange resins and acid clay.

Keywords: fats oil and greases (FOGs), free fatty acid, esterification reaction, methyl ester, PAN

Procedia PDF Downloads 204
3983 Inhibition Effect of Natural Junipers Extract towards Steel Corrosion in HCl Solution

Authors: L. Bammou, M. Belkhaouda R. Salghi, L. Bazzi, B. Hammouti

Abstract:

Steel and steel-based alloys of different grades steel are extensively used in numerous applications where acid solutions are widely applied such as industrial acid pickling, industrial acid cleaning and oil-well acidizing. The use of chemical inhibitors is one of the most practical methods for the protection against corrosion in acidic media. Most of the excellent acid inhibitors are organic compounds containing nitrogen, oxygen, phosphorus and sulphur. The use of non-toxic inhibitors called green or eco-friendly environmental inhibitors is one of the solutions possible to prevent the corrosion of the material. These advantages have incited us to draw a large part of program of our laboratory to examine natural substances as corrosion inhibitors such as: prickly pear seed oil, Argan oil, Argan extract, Fennel oil, Rosemary oil, Thymus oil, Lavender oil, Jojoba oil, Pennyroyal Mint oil, and Artemisia. In the present work, we investigate the corrosion inhibition of steel in 1 M HCl by junipers extract using weight loss, potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) methods. The result obtained of junipers extract (JE) shows excellent inhibition properties for the corrosion of C38 steel in 1M HCl at 298K, and the inhibition efficiency increases with increasing of the JE concentration. The inhibitor efficiencies determined by weight loss, Tafel polarisation and EIS methods are in reasonable agreement. Based on the polarisation results, the investigated junipers extract can be classified as mixed inhibitor. The calculated structural parameters show increase of the obtained Rct values and decrease of the capacitance, Cdl, with JE concentration increase. It is suggested to attribute this to the increase of the thickness of the adsorption layer at steel surface. The adsorption model obeys to the Langmuir adsorption isotherm. The adsorption process is a spontaneous and exothermic process.

Keywords: corrosion inhibition, steel, friendly inhibitors, Tafel polarisation

Procedia PDF Downloads 494
3982 Engineering Escherichia coli for Production of Short Chain Fatty Acid by Exploiting Fatty Acid Metabolic Pathway

Authors: Kamran Jawed, Anu Jose Mattam, Zia Fatma, Saima Wajid, Malik Z. Abdin, Syed Shams Yazdani

Abstract:

Worldwide demand of natural and sustainable fuels and chemicals have encouraged researchers to develop microbial platform for synthesis of short chain fatty acids as they are useful precursors to replace petroleum-based fuels and chemicals. In this study, we evaluated the role of fatty acid synthesis and β-oxidation cycle of Escherichia coli to produce butyric acid, a 4-carbon short chain fatty acid, with the help of three thioesterases, i.e., TesAT from Anaerococcus tetradius, TesBF from Bryantella formatexigens and TesBT from Bacteroides thetaiotaomicron. We found that E. coli strain transformed with gene for TesBT and grown in presence of 8 g/L glucose produced maximum butyric acid titer at 1.46 g/L, followed by that of TesBF at 0.85 g/L and TesAT at 0.12 g/L, indicating that these thioesterases were efficiently converting short chain fatty acyl-ACP intermediate of fatty acid synthesis pathway into the corresponding acid. The titer of butyric acid varied significantly depending upon the plasmid copy number and strain genotype. Deletion of genes for fatty acyl-CoA synthetase and acyl-CoA dehydrogenase, which are involved in initiating the fatty acid degradation cycle, and overexpression of FadR, which is a dual transcriptional regulator and exerts negative control over fatty acid degradation pathway, reduced up to 30% of butyric acid titer. This observation suggested that β-oxidation pathway is working synergistically with fatty acid synthesis pathway in production of butyric acid. Moreover, accelerating the fatty acid elongation cycle by overexpressing acetyl-CoA carboxyltransferase (Acc) and 3-hydroxy-acyl-ACP dehydratase (FabZ) or by deleting FabR, the transcription suppressor of elongation, did not improve the butyric acid titer, rather favored the long chain fatty acid production. Finally, a balance between cell growth and butyric acid production was achieved with the use of phosphorous limited growth medium and 14.3 g/L butyric acid, and 17.5 g/L total free fatty acids (FFAs) titer was achieved during fed-batch cultivation. We have engineered an E. coli strain which utilizes the intermediate of both fatty acid synthesis and degradation pathway, i.e. butyryl-ACP and -CoA, to produce butyric acid from glucose. The strategy used in this study resulted in highest reported titers of butyric acid and FFAs in engineered E. coli.

Keywords: butenoic acid, butyric acid, Escherichia coli, fed-batch fermentation, short chain fatty acids, thioesterase

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3981 Process Performance and Nitrogen Removal Kinetics in Anammox Hybrid Reactor

Authors: Swati Tomar, Sunil Kumar Gupta

Abstract:

Anammox is a promising and cost effective alternative to conventional treatment systems that facilitates direct oxidation of ammonium nitrogen under anaerobic conditions with nitrite as an electron acceptor without addition of any external carbon sources. The present study investigates the process kinetics of laboratory scale anammox hybrid reactor (AHR) which combines the dual advantages of attached and suspended growth. The performance & behaviour of AHR was studied under varying hydraulic retention time (HRTs) and nitrogen loading rate (NLRs). The experimental unit consisted of 4 numbers of 5L capacity anammox hybrid reactor inoculated with mixed seed culture containing anoxic and activated sludge. Pseudo steady state (PSS) ammonium and nitrite removal efficiencies of 90.6% and 95.6%, respectively, were achieved during acclimation phase. After establishment of PSS, the performance of AHR was monitored at seven different HRTs of 3.0, 2.5, 2.0, 1.5, 1.0, 0.5 and 0.25 d with increasing NLR from 0.4 to 4.8 kg N/m3d. The results showed that with increase in NLR and decrease in HRT (3.0 to 0.25 d), AHR registered appreciable decline in nitrogen removal efficiency from 92.9% to 67.4 %, respectively. The HRT of 2.0 d was considered optimal to achieve substantial nitrogen removal of 89%, because on further decrease in HRT below 1.5 days, remarkable decline in the values of nitrogen removal efficiency were observed. Analysis of data indicated that attached growth system contributes an additional 15.4 % ammonium removal and reduced the sludge washout rate (additional 29% reduction). This enhanced performance may be attributed to 25% increase in sludge retention time due to the attached growth media. Three kinetic models, namely, first order, Monod and Modified Stover-Kincannon model were applied to assess the substrate removal kinetics of nitrogen removal in AHR. Validation of the models were carried out by comparing experimental set of data with the predicted values obtained from the respective models. For substrate removal kinetics, model validation revealed that Modified Stover-Kincannon is most precise (R2=0.943) and can be suitably applied to predict the kinetics of nitrogen removal in AHR. Lawrence and McCarty model described the kinetics of bacterial growth. The predicted value of yield coefficient and decay constant were in line with the experimentally observed values.

Keywords: anammox, kinetics, modelling, nitrogen removal, sludge wash out rate, AHR

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3980 Prediction of the Solubility of Benzoic Acid in Supercritical CO2 Using the PC-SAFT EoS

Authors: Hamidreza Bagheri, Alireza Shariati

Abstract:

There are many difficulties in the purification of raw components and products. However, researchers are seeking better ways for purification. One of the recent methods is extraction using supercritical fluids. In this study, the phase equilibria of benzoic acid-supercritical carbon dioxide system were investigated. Regarding the phase equilibria of this system, the modeling of solid-supercritical fluid behavior was performed using the Perturbed-Chain Statistical Association Fluid Theory (PC-SAFT) and Peng-Robinson equations of state (PR EoS). For this purpose, five PC-SAFT EoS parameters for pure benzoic acid were obtained using its experimental vapor pressure. Benzoic acid has association sites and the behavior of the benzoic acid-supercritical fluid system was well-predicted using both equations of state, while the binary interaction parameter values for PR EoS were negative. Genetic algorithm, which is one of the most accurate global optimization algorithms, was also used to optimize the pure benzoic acid parameters and the binary interaction parameters. The AAD% value for the PC-SAFT EoS, were 0.22 for the carbon dioxide-benzoic acid system.

Keywords: supercritical fluids, solubility, solid, PC-SAFT EoS, genetic algorithm

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3979 Lipoic Acid Accelerates Wound Healing by Diminishing Pro-Inflammatory Markers and Chemokine Expression in Rheumatoid Arthritis Mouse Model

Authors: Khairy M. A. Zoheir

Abstract:

One of the most severe complications of Rheumatoid arthritis is delayed recovery. lipoic acid possesses antioxidant, hypoglycemic, and anti-inflammatory activity. In the present study, the effects of lipoic acid was investigated on the key mediators of Rheumatoid arthritis, namely, CD4+CD25+ T cell subsets, GITR expressing cells, CD4+CD25+Foxp3+ regulatory T (Treg) cells, T-helper-17 (Th17) cells, and pro-inflammatory cytokines Interleukin-1β (IL-1β), Interleukin-6 (IL-6) and Tumor Necrosis Factor- α (TNF-α)] through flow-cytometry and qPCR analyses. Lipoic acid treated mice showed a significant decrease in the Rheumatoid arthritis, the frequency of GITR-expressing cells, and Th1 cytokines (IL-17A, TNF-αand Interferon- γ (IFN-γ) compared with positive and negative controlled mice. Lipoic acid treatment also down regulated the mRNA expression of the inflammatory mediators compared with the Rheumatoid arthritis mouse model and untreated mice. The number of Tregs also found to be significantly upregulated in lipoic acid treated mice. Our results were confirmed by the histopathological examination. This study showed the beneficial role of lipoic acid in promoting a well-balanced tool for therapy Rheumatoid arthritis.

Keywords: lipoic acid, chemokines, inflammatory, rheumatoid arthritis

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3978 Effects of Post-Emergence Herbicides on Soil Micro-Flora and Nitrogen Fixing Bacteria in Pea Field

Authors: Ali M. Zaid, Muftah Mayouf, Yahya Said Farouj

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The effect of post emergence herbicides on soil micro-flora and nitrogen fixing bacteria was studied in pea field. Pea (Pisum sativum) was grown and treated with one or a mixture of two of several herbicides 2 weeks after sowing. Soil samples were collected 2 weeks after herbicides application. Average number of colony forming units per gram of soil of bacteria, actinomycetes and fungi were determined. Average number of nodules per plant was obtained at the end of the growing season. The results of the study showed MCPB, Bentazon, MCPB+Fluozifop-p-butyl, Bentazon+Fluozifop-p-butyl, Metribuzin, Flouzifop-p-butyl+Metribuzin, Cycloxydin, and Sethoxydin increased the population of soil fungi, with 4 to 10 times compared with the control. The herbicides used showed no significant effects on nitrogen fixing bacteria. The effects of herbicides on soil bacteria and actinomycetes were different. The study showed the use of herbicides could influence the biological balance of soil microflora, which has an important role in soil fertility and microbial ecosystem.

Keywords: herbicides, post emergence, nitrogen fixing bacteria, environmental systems

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3977 The Effect of Heating-Liquid Nitrogen Cooling on Fracture Toughness of Anisotropic Rock

Authors: A. Kavandi, K. Goshtasbi, M. R. Hadei, H. Nejati

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In geothermal energy production, the method of liquid nitrogen (LN₂) fracturing in hot, dry rock is one of the most effective methods to increase the permeability of the reservoir. The geothermal reservoirs mainly consist of hard rocks such as granites and metamorphic rocks like gneiss with high temperatures. Gneiss, as a metamorphic rock, experiences a high level of inherent anisotropy. This type of anisotropy is considered as the nature of rocks, which affects the mechanical behavior of rocks. The aim of this study is to investigate the effects of heating-liquid nitrogen (LN₂) cooling treatment and rock anisotropy on the fracture toughness of gneiss. For this aim, a series of semi-circular bend (SCB) tests were carried out on specimens of gneiss with different anisotropy plane angles (0°, 30°, 60°, and 90°). In this study, gneiss specimens were exposed to heating–cooling treatment through gradual heating to 100°C followed by LN₂ cooling. Results indicate that the fracture toughness of treated samples is lower than that of untreated samples, and with increasing the anisotropy plane angle, the fracture toughness increases. The scanning electron microscope (SEM) technique is also implemented to evaluate the fracture process zone (FPZ) ahead of the crack tip.

Keywords: heating-cooling, anisotropic rock, fracture toughness, liquid nitrogen

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3976 Urea Treatment of Low Dry Matter Oat Silage

Authors: Noor-ul-Ain, Muhammad Tahir Khan, Kashif Khan, Adeela Ajmal, Hamid Mustafa

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The objective of this study was to evaluate the preservative and upgrading potential of urea (70g/kg DM) added to high moisture oat silage at laboratory scale trial and urea was hydrolysed 95%. Microbial activity measured by pH and volatile fatty acids (VFA) and lactate production was reduced (p<0.001) by the urea addition. The pH of oat silage (without treated) was measured 5.7 and increased up to 8.00 on average while; volatile fatty acids (VFA) concentration was decreased. Relative proportions of fermentation acids changed after urea addition, increasing the acetate and butyrate and decreasing the propionate and lactate proportions. The addition of urea to oat silages increased (P<0.001) water soluble and ammonium nitrogen of the forage. These nitrogen fractions represented more than 40% of total nitrogen. After urea addition, total nitrogen content of oat silages increased from 21.0 g/kg DM to 28 g/kg DM. Application of urea at a rate of 70 g/kg DM significantly increased (P<0.001) the in situ degradation of neutral-detergent fibre after 48h of rumen incubation (NDF-situ). The NDF-situ was 200 g/kg NDF higher on oat forages ensiled with urea than on oat forages ensiled without urea. Oat silages can be effectively preserved and upgraded by ensiling with 70 g urea/kg dry matter. Further studies are required to evaluate voluntary intake of this forage.

Keywords: oat, silage, urea, pH, forage

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3975 Statistical Optimization of Distribution Coefficient for Reactive Extraction of Lactic Acid Using Tri-n-octyl Amine in Oleyl Alcohol and n-Hexane

Authors: Avinash Thakur, Parmjit S. Panesar, Manohar Singh

Abstract:

The distribution coefficient, KD for the reactive extraction of lactic acid from aqueous solutions of lactic acid using 10-30% (v/v) tri-n-octyl amine (extractant) dissolved in n-hexane (inert diluent) and 20% (v/v) oleyl alcohol (modifier) was optimized by using response surface methodology (RSM). A three level Box-Behnken design was employed for experimental design, analysis of the results and to depict the combined interactive effect of seven independent variables, viz lactic acid concentration (cl), pH, TOA concentration in organic phase (ψ), treat ratio (φ), temperature (T), agitation speed (ω) and batch agitation time (τ) on distribution coefficient of lactic acid. The regression analysis recommended that the quadratic model is significant (R2 and adjusted R2 are 98.72 % and 98.69 % respectively) for analysis. A numerical optimization had resulted in maximum lactic acid distribution coefficient (KD) of 3.16 at the optimized values for test variables, cl, pH, ψ, φ, T, ω and τ as 0.15 [M], 3.0, 22.75% (v/v), 1.0 (v/v), 26°C, 145 rpm and 23 min respectively. A good agreement between the predicted and experimentally obtained values for distribution coefficient using the optimized conditions was exhibited.

Keywords: Distribution coefficient, tri-n-octylamine, lactic acid, response surface methodology

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3974 Growth and Biochemical Composition of Tetraselmis sp. and Chlorella sp. under Varied Growth Conditions

Authors: M. Alsull

Abstract:

In this study, Tetraselmis sp. and Chlorella sp. isolated from Penang National Park coastal waters, Malaysia, and cultivated under combined various laboratory conditions (temperature, light and nitrogen limitation and starvation). Growth rate, dry weight, chlorophyll a content, total lipids content and total carbohydrates content were estimated at mid-exponential growth phase. Tetraselmis sp. and Chlorella sp. showed remarkably decrease in growth rate, chlorophyll a content and dry weight when maintained under nitrogen limitation and starvation conditions, as well as when grown under 12:12 h light, dark regime conditions. Chlorella sp. showed ability to counter the fluctuation in temperature with no significant effects on the measured parameters; in contrast, Tetraselmis sp. showed a decrease in growth rate, chlorophyll a content and dry weight when grown under 15±1˚C temperature. Cultures maintained under nitrogen full concentration, and 24 h light regime showed decrease in total lipids content, compared with 12:12 h light, dark cycle regime, in the two tested species.

Keywords: microalgae, biochemical composition, temperature, light, nitrogen limitation

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3973 Study the Effect of Lipoid Acid as a Protective Against Rheumatoid Arthritis Through Diminishing Pro-inflammatory Markers and Chemokine Expression

Authors: Khairy Mohamed Abdalla Zoheir

Abstract:

One of the most severe complications of Rheumatoid arthritis is delayed recovery. lipoic acid possesses antioxidant, hypoglycemic, and anti-inflammatory activity. In the present study, the effects of lipoic acid were investigated on the key mediators of Rheumatoid arthritis, namely, CD4+CD25+ T cell subsets, GITR expressing cells, CD4+CD25+Foxp3+ regulatory T (Treg) cells, T-helper-17 (Th17) cells and pro-inflammatory cytokines Interleukin-1β (IL-1β), Interleukin-6 (IL-6) and Tumor Necrosis Factor- α (TNF-α)] through flow-cytometry and qPCR analyses. Lipoic acid-treated mice showed a significant decrease in Rheumatoid arthritis, the frequency of GITR-expressing cells, and Th1 cytokines (IL-17A, TNF-αand Interferon- γ (IFN-γ) compared with positive and negative controlled mice. Lipoic acid treatment also downregulated the mRNA expression of the inflammatory mediators compared with the Rheumatoid arthritis mouse model and untreated mice. The number of Tregs was also found to be significantly upregulated in lipoic acid-treated mice. Our results were confirmed by the histopathological examination. This study showed the beneficial role of lipoic acid in promoting a well-balanced tool for the therapy of Rheumatoid arthritis.

Keywords: lipoic acid, inflammatory markers, rheumatoid arthritis, qPCR

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3972 Biocompatible Ionic Liquids in Liquid-Liquid Extraction of Lactic Acid: A Comparative Study

Authors: Konstantza Tonova, Ivan Svinyarov, Milen G. Bogdanov

Abstract:

Ionic liquids consisting of pairs of imidazolium or phosphonium cation and chloride or saccharinate anion were synthesized and compared with respect to their extraction efficiency towards the fermentative L-lactic acid. The acid partitioning in the equilibrated biphasic systems of ionic liquid and water was quantified through the extraction degree and the partition coefficient. The water transfer from the aqueous into the ionic liquid-rich phase was also always followed. The effect of pH, which determines the state of lactic acid in the aqueous source was studied. The effect of other salting-out substances that modify the ionic liquid/water equilibrium was also investigated in view to reveal the best liquid-liquid system with respect to low toxicity, high extraction and back extraction efficiencies and performance simplicity.

Keywords: ionic liquids, biphasic system, extraction, lactic acid

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3971 Nitrogen and Potassium Fertilizer Response on Growth and Yield of Hybrid Luffa –Naga F1 Variety

Authors: D. R. T. N. K. Dissanayake, H. M. S. K. Herath, H. K. S. G. Gunadasa, P. Weerasinghe

Abstract:

Luffa is a tropical and subtropical vegetable, belongs to family Cucurbiteceae. It is predominantly monoecious in sex expression and provides an ample scope for utilization of hybrid vigor. Hybrid varieties develop through open pollination, produce higher yields due to its hybrid vigor. Naga F1 hybrid variety consists number of desirable traits other than higher yield such as strong and vigorous plants, fruits with long deep ridges, attractive green color fruits ,better fruit weight, length and early maturity compared to the local Luffa cultivars. Unavailability of fertilizer recommendations for hybrid cucurbit vegetables leads to an excess fertilizer application causing a vital environmental issue that creates undesirable impacts on nature and the human health. Main Objective of this research is to determine effect of different nitrogen and potassium fertilizer rates on growth and yield of Naga F1 Variety. Other objectives are, to evaluate specific growth parameters and yield, to identify the optimum nitrogen and potassium fertilizer levels based on growth and yield of hybrid Luffa variety. As well as to formulate the general fertilizer recommendation for hybrid Luffa -Naga F1 variety.

Keywords: hybrid, nitrogen, phosphorous, potassium

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3970 Catalytic Deoxygenation of Propionic Acid in the Vapour Phase

Authors: Hossein Bayahia, Mohammed Saad Motlaq Al-Gahmdi

Abstract:

The gas-phase deoxygenation of propionic acid was investigated in the presence of Co-Mo catalysts in N2 or H2 flow at 200-400 °C. In the presence of N2 the main product was 3-pentanone with other deoxygenates and some light gases: ethane and ethene. Using H2 flow, the catalyst was active for decarboxylation and decarbonylation of acid and the yields of ethane and ethene. The decarboxylation and decarbonylation reactions increased with increasing temperature. Cobalt-molybdenum supported on alumina showed better performance than bulk catalyst, especially at 400 °C in the presence of N2 for the ketonisation of propionic acid to form 3-pentanone as the main product. Bulk and supported catalysts were characterized by surface area porosity (BET), thermogravimetric analysis (TGA) and diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) of pyridine adsorption.

Keywords: deoxygenation, propionic acid, gas-phase, catalyst

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3969 Effects of Folic Acid, Alone or in Combination with Other Nutrients on Homocysteine Level and Cognitive Function in Older People: A Systematic Review

Authors: Jiayan Gou, Kexin He, Xin Zhang, Fei Wang, Liuni Zou

Abstract:

Background: Homocysteine is a high-risk factor for cognitive decline, and folic acid supplementation can lower homocysteine levels. However, current clinical research results are inconsistent, and the effects of folic acid on homocysteine levels and cognitive function in older people are inconsistent. Objective: The objective of this study is to systematically evaluate the effects of folic acid alone or in combination with other nutrients on homocysteine levels and cognitive function in older adults. Methods: Systematic searches were conducted in five databases, including PubMed, Embase, the Cochrane Library, Web of Science, and CINAHL, from inception to June 1, 2023. Randomized controlled trials were included investigating the effects of folic acid alone or in combination with other nutrients on cognitive function in older people. Results: 17 articles were included, with six focusing on the effects of folic acid alone and 11 examining folic acid in combination with other nutrients. The study included 3,100 individuals aged 60 to 83.2 years, with a relatively equal gender distribution (approximately 51.82% male). Conclusion: Folic acid alone or combined with other nutrients can effectively lower homocysteine level and improve cognitive function in patients with mild cognitive impairment. But for patients with Alzheimer's disease and dementia, the intervention only can reduce the homocysteine level, but the improvement in cognitive function is not significant. In healthy older people, high baseline homocysteine levels (>11.3 μmol/L) and good ω-3 fatty acid status (>590 μmol/L) can enhance the improvement effect of folic acid on cognitive function. This trial has been registered on PROSPERO as CRD42023433096.

Keywords: B-complex vitamins, cognitive function, folic acid, homocysteine

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3968 Mechanical Behavior of Hybrid Hemp/Jute Fibers Reinforced Polymer Composites at Liquid Nitrogen Temperature

Authors: B. Vinod, L. Jsudev

Abstract:

Natural fibers as reinforcement in polymer matrix material is gaining lot of attention in recent years, as they are light in weight, less in cost, and ecologically advanced surrogate material to glass and carbon fibers in composites. Natural fibers like jute, sisal, coir, hemp, banana etc. have attracted substantial importance as a potential structural material because of its attractive features along with its good mechanical properties. Cryogenic applications of natural fiber reinforced polymer composites like cryogenic wind tunnels, cryogenic transport vessels, support structures in space shuttles and rockets are gaining importance. In these unique cryogenic applications, the requirements of polymer composites are extremely severe and complicated. These materials need to possess good mechanical and physical properties at cryogenic temperatures such as liquid helium (4.2 K), liquid hydrogen (20 K), liquid nitrogen (77 K), and liquid oxygen (90 K) temperatures, etc., to meet the high requirements by the cryogenic engineering applications. The objective of this work is to investigate the mechanical behavior of hybrid hemp/jute fibers reinforced epoxy composite material at liquid nitrogen temperature. Hemp and Jute fibers are used as reinforcement material as they have high specific strength, stiffness and good adhering property and has the potential to replace the synthetic fibers. Hybrid hemp/jute fibers reinforced polymer composite is prepared by hand lay-up method and test specimens are cut according to ASTM standards. These test specimens are dipped in liquid nitrogen for different time durations. The tensile properties, flexural properties and impact strength of the specimen are tested immediately after the specimens are removed from liquid nitrogen container. The experimental results indicate that the cryogenic treatment of the polymer composite has a significant effect on the mechanical properties of this material. The tensile properties and flexural properties of the hybrid hemp/jute fibers epoxy composite at liquid nitrogen temperature is higher than at room temperature. The impact strength of the material decreased after subjecting it to liquid nitrogen temperature.

Keywords: liquid nitrogen temperature, polymer composite, tensile properties, flexural properties

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3967 Impact of Nitrogen Fertilization on Soil Respiration and Net Ecosystem Production in Maize

Authors: Shirley Lamptey, Lingling Li, Junhong Xie

Abstract:

Agriculture in the semi-arid is often challenged by overuse of N, inadequate soil water, and heavy carbon emissions thereby threatening sustainability. Field experiments were conducted to investigate the effect of nitrogen fertilization levels (0-N₀, 100-N₁₀₀, 200-N₂₀₀, and 300 kg ha⁻¹-N₃₀₀) on soil water dynamics, soil respiration (Rs), net ecosystem production (NEP), and biomass yield. Zero nitrogen soils decreased Rs by 23% and 16% compared to N₃₀₀ and N₂₀₀ soils, respectively. However, biomass yield was greatest under N₃₀₀ compared with N₀, which therefore translated into increased net primary production (NPP) by 89% and NEP by 101% compared to N₀. To a lesser extent, N₂₀₀ increased net primary production by 69% and net ecosystem production by 79% compared to N₀. Grain yields were greatest under N₃₀₀ compared with N₁₀₀ and N₀, which therefore translated into increased carbon emission efficiency (CEE) by 53%, 39% and 3% under N₃₀₀ compared to N₀, N₁₀₀, and N₂₀₀ treatments respectively. Under the conditions of this study, crop yield and CEE may be optimized at nitrogen application rates in the range of 200-300 kg ha⁻¹. Based on these results, there appears potential for 200 kg N ha⁻¹ to be used to improve yield and increase CEE in the context of the rainfall-limiting environment.

Keywords: carbon emission, carbon emission efficiency, C sequestration, N rates, semi-arid

Procedia PDF Downloads 211