Excellence in Research and Innovation for Humanity

International Science Index

Commenced in January 1999 Frequency: Monthly Edition: International Abstract Count: 39602

Chemical and Molecular Engineering

1653
67013
Removal of Phenol from Aqueous Solution Using Watermelon (Citrullus C. lanatus) Rind
Abstract:
This study focuses on investigating the effectiveness of watermelon rind in phenol removal from aqueous solution. The effects of various parameters (pH, initial phenol concentration, biosorbent dosage and contact time) on phenol adsorption were investigated. The pH of 2, initial phenol concentration of 40 ppm, the biosorbent dosage of 0.6 g and contact time of 6 h also deduced to be the optimum conditions for the adsorption process. The maximum phenol removal under optimized conditions was 85%. The sorption data fitted to the Freundlich isotherm with a regression coefficient of 0.9824. The kinetics was best described by the intraparticle diffusion model and Elovich Equation with regression coefficients of 1 and 0.8461 respectively showing that the reaction is chemisorption on a heterogeneous surface and the intraparticle diffusion rate only is the rate determining step. The study revealed that watermelon rind has a potential of removing phenol from industrial wastewaters.
1652
67006
Influence of Annealing on the Mechanical αc-Relaxation of Isotactic-Polypropylene: A Study from the Intermediate Phase Perspective
Abstract:
In this work, the influence of annealing on the mechanical αc-relaxation behavior of isotactic polypropylene (iPP) was investigated. The results suggest that the mechanical αc-relaxation behavior depends strongly on the confinement force on the polymer chains in the intermediate phase and the thickness of the intermediate phase. After quenching at 10°C, abundant crystallites with a wide size distribution are formed. The polymer chains in the intermediate phase are constrained by the crystallites, giving rise to one broad αc-relaxation peak. With an annealing temperature between 60°C~105°C, imperfect lamellae melting releases part of the constraint force, which reduces the conformational ordering of the polymer chains neighboring the amorphous phase. Consequently, two separate αc-relaxation peaks could be observed which are labeled as αc1-relaxation and αc2-relaxation. αc1-relaxation and αc2-relaxation describe the relaxation behavior of polymer chains in the region close to the amorphous phase and the crystalline phase, respectively. Both relaxation peaks shift to a higher temperature as annealing temperature increases. With an annealing temperature higher than 105°C, the new crystalline phase is formed in the intermediate phase, which enhances the constraint force on the polymer chains. αc1-relaxation peak is broadened obviously and its position shifts to a higher temperature as annealing temperature increases. Moreover, αc2-relaxation is undetectable because that the polymer chains in the region between the initial crystalline phase and the newly formed crystalline phase are strongly confined.
1651
66955
The Inversion of Helical Twist Sense in Liquid Crystal Phases
Abstract:
The chiral liquid crystal phases from the helicoidal structure, which is characterized by helical pitch and helical twist sense. The knowledge of these parameters is very important for production of displays. The most common method to measure them is based on the selective light reflection phenomenon. Unfortunately, this method has the limit of the measuring range of the used spectrophotometer. In liquid crystal phases three types of helix temperature dependence have been obtained: increased helical pitch with temperature and right-handed helix, decreased helical pitch and left-handed helix and the inversion of both. In this work the inversion of helical twist sense in the chiral organic compounds like antiferroelectric liquid crystals was tested by electronic circular dichroism and vibrational circular dichroism. These results were compared with the results from polarimetry technique. The obtained results confirm that the inversion of helical twist sense in liquid crystalline chiral phase may be connected with the presence of different conformers with opposite handedness.
1650
66925
Enhanced Production of Endo-β-1,4-Xylanase from a Newly Isolated Thermophile Geobacillus stearothermophilus KIBGE-IB29 for Prospective Industrial Applications
Abstract:
Endo-β-1,4-xylanases [EC 3.2.1.8] are one of the major groups of enzymes that are involved in degradation process of xylan and have several applications in food, textile and paper processing industries. Due to broad utility of endo-β-1,4-xylanase, researchers are focusing to increase the productivity of this hydrolase from various microbial species. Harsh industrial condition, faster reaction rate and efficient hydrolysis of xylan with low risk of contamination are critical requirements of industry that can be fulfilled by synthesizing the enzyme with efficient properties. In the current study, a newly isolated thermophile Geobacillus stearothermophilus KIBGE-IB29 was used in order to attain the maximum production of endo-1,4-β-xylanase. Bacterial culture was isolated from soil, collected around the blast furnace site of a steel processing mill, Karachi. Optimization of various nutritional and physical factors resulted the maximum synthesis of endo-1,4-β-xylanase from a thermophile. High production yield was achieved at 60°C and pH-6.0 after 24 hours of incubation period. Various nitrogen sources viz. peptone, yeast extract and meat extract improved the enzyme synthesis with 0.5%, 0.2% and 0.1% optimum concentrations. Dipotassium hydrogen phosphate (0.25%), potassium dihydrogen phosphate (0.05%), ammonium sulfate (0.05%) and calcium chloride (0.01%) were noticed as valuable salts to improve the production of enzyme. The thermophilic nature of isolate, with its broad pH stability profile and reduced fermentation time indicates its importance for effective xylan saccharification and for large scale production of endo-1,4-β-xylanase.
1649
66883
Biosorption Of Chromium (VI) Ions Using Polyaniline Coated Maize Tassels
Abstract:
Hexavalent chromium is toxic and is widely used in many industries hence efficient and economical methods must be explored to remove the chromium(VI) from the environment. The removal of Cr (VI) from aqueous solutions onto polyaniline coated maize tassel was studied in batch mode at varying initial metal concentrations, adsorbent doses, pH and contact times. The residual Cr (VI) concentrations before and after adsorption were analyzed by Ultraviolet–visible spectroscopy. FTIR analysis of the polyaniline coated maize tassel showed the presence of C=C, C=N, C-H, C-N and N-H groups. Adsorption conditions were deduced to be pH of 2, adsorbent dosage 1g/L, Cr(VI) initial concentration of 40mg/L contact time of 150 minutes and agitation speed of 140rpm. Data obtained fitted best to the Langmuir isotherm (R2 = 0.972) compared to the Freundlich isotherm (R2 0.671. The maximum adsorption capacity was found to be 125mg/L. Correlation coefficients for pseudo first order and pseudo second order were 0.952 and 0.971 respectively. The adsorption process followed the pseudo-second order kinetic model. The studied polyaniline coated maize tassel can therefore be used as a promising adsorbent for the removal of Cr (VI) ion from aqueous solution.
1648
66845
Beijerinckia indica Extracellular Extract Mediated Green Synthesis of Silver Nanoparticles with Excellent Antioxidant and Antibacterial Activity against Selected Clinical Pathogens
Abstract:
The present work investigated the use of Beijerinckia indica extracellular extract for the synthesis of silver nanoparticles using AgNO3. The formation of nanoparticles was confirmed by different methods such as physical appearance change, UV-Vis absorbance change, XRD, FTIR, EDX and TEM analysis. The formation of silver nanoparticles was first observed by observing the solution colour change from light yellow to dark brown indicated formation of AgNPs (Silver nanoparticles). The absorbance peak obtained at 430 nm confirmed the synthesis of silver nanoparticles. The phase of silver nanoparticle is confirmed by XRD analysis and it shows that the synthesized nanoparticles are a cubic crystalline phase. FTIR revealed the presence of groups that acts as stabilizing and reducing agents for silver nanoparticles formation. The synthesized silver nanoparticles were generally found to be spherical in shape with size ranging from 5 to 20 nm, as evident by TEM analysis. These nanoparticles found to have excellent antioxidant activity and inhibited the growth of clinical bacterial strains. This work proved that the bacterial extract is a potential eco-friendly candidate for the synthesis of silver nanoparticles with promising antioxidant and antibacterial property.
1647
66802
Surface Modification of Poly High Internal Phase Emulsion by Solution Plasma Process for CO2 Adsorption
Abstract:
An increase in the amount of atmospheric carbon dioxide (CO2) resulting from anthropogenic CO2 emission has been a concerned problem so far. Adsorption using porous materials is feasible way to reduce the content of CO2 emission into the atmosphere due to several advantages: low energy consumption in regeneration process, low-cost raw materials and, high CO2 adsorption capacity. In this work, the porous poly(divinylbenzene) (poly(DVB)) support was synthesized under high internal phase emulsion (HIPE) polymerization then modified with polyethyleneimine (PEI) by using solution plasma process. These porous polymers were then used as adsorbents for CO2 adsorption study. All samples were characterized by some techniques: Fourier transform infrared spectroscopy (FT-IR), scanning electron spectroscopy (SEM), water contact angle measurement and, surface area analyzer. The results of FT-IR and a decrease in contact angle, pore volume and, surface area of PEI-loaded materials demonstrated that surface of poly(DVB) support was modified. In other words, amine groups were introduced to poly(DVB) surface. In addition, not only the outer surface of poly(DVB) adsorbent was modified, but also the inner structure as shown by FT-IR study. As a result, PEI-loaded materials exhibited higher adsorption capacity, comparing with those of the unmodified poly(DVB) support.
1646
66672
Bio-Oil Production and Chromatographic Characterization from the Pyrolysis of Oil Palm Empty Fruit Bunches
Abstract:
Oil palm empty fruit bunches, derived biomass available in Indonesia, is one of the potential biomass to produce biofuels like bio-oil due to its abundant supply and favorable physicochemical characteristics. An interesting alternative of utilising the oil palm empty fruit bunches is in the production of bio-oil by pyrolysis. Pyrolysis of oil palm empty fruit bunches to bio-oil is being considered for national energy security and environmental advantages. The aim of this study was to produce bio-oil by pyrolysis of oil palm empty fruit bunches at various temperature and observe its detailed chemical composition. The biomass was submitted to a pyrolysis in a batch reactor. Experiments were carried out at a temperature range of 450–600°C and heating rate range of 10-20°C/min. The yield of bio-oil was found to be maximum at the temperature of 600°C. The bio-oils detailed compositions were investigated using FTIR and GC-MS. The bio-char produced as a co-product can be a potential soil amendment with multiple benefits including soil fertility and for solid fuel applications that also contributes to the preservation of the environment. The present investigation suggests the suitability of oil palm empty fruit bunches as a potential feedstock for exploitation of energy and biomaterials through pyrolysis process.
1645
66636
Enhanced Enzymatic Saccharification of Waste Sugarcane Leaves Using Salt-Acid Pretreatment
Abstract:
The objective of this study was to develop a combined salt and acid pretreatment strategy for the enhanced enzymatic saccharification of waste sugarcane leaves. Zinc chloride and sulfuric acid were employed as chemical catalysts to examine the enzymatic digestibility with Novozymes Cellic Ctec 2 at a lab scale. Leaves were pretreated using a combination of 1M, 3M, 5M ZnCl₂ and 1.55 % H₂SO₄ (v/v) with a solid loading of 10% (w/v) at 121°C for 60 min. After washing, enzymatic saccharification was conducted on the biomass with an enzyme and solid loading of 10 FPU/g dry weight and 10% (w/v) respectively. Preliminary results indicated a glucose yield of 9.5 g/L per gram of dry weight sugarcane leaves using 3M ZnCl₂ and 1.55% H₂SO₄. This yield showed an improvement over salt treatment and water treatment by 22% and 98% respectively. In addition, this study allowed a yield improvement of 15.8% compared to previously reported studies employing solely concentrated phosphoric acid. Further optimization of key chemical (salt concentration, acid concentration, and solid loading) and enzymatic (enzyme loading, solid loading) parameters will further enhance glucose yield. These findings illustrate the potential of a mild hybrid chemical pretreatment to enhance glucose recovery from lignocellulosic materials such as sugarcane leaves.
1644
66621
Radiation Effects in the PVDF/Graphene Oxide Nanocomposites
Abstract:
Exposure to ionizing radiation has been found to induce changes in poly(vinylidene fluoride) (PVDF) homopolymers. The high-dose gamma irradiation process induces the formation of C=C and C=O bonds and the decreasing of its melting latent heat (LM) and, consequently, of its crystalline order. We have investigated the possibility of preparing nanocomposites of PVDF with graphene oxide (GO) through the radio-induction of molecular bonds between the polymeric material and the carbon nanostructures. This investigation aimed to produce nanocomposites with new properties related to the PVDF beta-crystalline phase such as high piezoelectricity and relaxor ferroelectric behavior. In this work, we discuss how the gamma radiation interacts with the nanocomposite crystalline structure.
1643
66534
Biodiesel Production from Canola Oil Using Trans-Esterification Process with Koh as a Catalyst
Abstract:
Biodiesel is one solution to overcome the use of petroleum fuels. Many alternative feedstocks that can be used among which canola oil. The purpose of this study was to determine the ability of canola oil and KOH for the trans-esterification reaction in biodiesel production. Canola oil has a very high purity that can be used as an alternative feedstock for biodiesel production and expected it will be produced biodiesel with excellent quality. In this case of study, we used trans-esterification process wherein the triglyceride is reacted with an alcohol with KOH as a catalyst, and it will produce biodiesel and glycerol as byproduct and we choose trans-esterification process because canola oil has a 0,445% FFA content. The variables studied in this research include the comparison of canola oil and methanol, temperature, time, and the percent of catalyst used. In this study the method of analysis we use GCMS and FTIR to know what the characteristic in canola oil. Development of canola oil seems to be the perfect solution to produce high-quality biodiesel. The reaction conditions resulted in 97.87% -w methyl ester (biodiesel) product by using a 0.5% wt KOH catalyst with canola and methanol ratio 1:8 at 60°C.
1642
66371
Toluene Methylation with Methanol Using Synthesized HZSM-5 Catalysts Modified by Silylation and Dealumination
Abstract:
Due to its abundance from catalytic reforming and thermal cracking of naphtha, toluene could become more value-added compound if it is converted into xylenes, particularly p-xylene, via toluene methylation. Attractively, toluene methylation with methanol is an alternative route to produce xylenes in the absence of other hydrocarbon by-products for which appropriate catalyst would be utilized. In this study, HZSM-5 catalysts with Si/Al molar ratio of 100 were synthesized via hydrothermal treatment and modified by either chemical liquid deposition using tetraethyl-orthosilicate or dealumination with steam. The modified catalysts were characterized by several techniques and tested for their catalytic activity in a continuous down-flow fixed bed reactor. Various operating conditions including WHSV’s of 5 to 20 h-1, reaction temperatures of 400 to 500 °C, and toluene-to-methanol molar ratios (T/M) of 1 to 4 were investigated for attaining possible highest p-xylene selectivity. As a result, the catalytic activity of parent HZSM-5 with temperature of 400 °C, T/M of 4 and WHSV of 24 h-1 showed 65.36% in p-xylene selectivity and 11.90% in toluene conversion as demonstrated for 4 h on stream.
1641
66342
Correlation Analysis of Reactivity in the Oxidation of Para and Meta-Substituted Benzyl Alcohols by Benzimidazolium Dichromate in Non-Aqueous Media: A Kinetic and Mechanistic Aspects
Abstract:
An observed correlation of the reaction rates with the changes in the nature of substituent present on one of the reactants often reveals the nature of transition state. Selective oxidation of organic compounds under non-aqueous media is an important transformation in synthetic organic chemistry. Inorganic chromates and dichromates being drastic oxidant and are generally insoluble in most organic solvents, a number of different chromium (VI) derivatives have been synthesized. Benzimidazolium dichromate (BIDC) is one of the recently reported Cr(VI) reagents which is neither hygroscopic nor light sensitive being, therefore, much stable. Not many reports on the kinetics of the oxidations by BIDC are seemed to be available in the literature. In the present investigation, the kinetics and mechanism of benzyl alcohol (BA) and a number of para- and meta-substituted benzyl alcohols by benzimidazolium dichromate (BIDC), in dimethyl sulphoxide, is reported. The reactions were followed spectrophotometrically at 364 nm by monitoring the decrease in [BIDC] for up to 85-90% reaction, the temperature being constant. The observed oxidation product is the corresponding benzaldehyde. The reactions were of first order with respect to each the alcohol and BIDC. The reactions are catalyzed by proton, and the dependence is of the form: kobs = a + b[H+]. The reactions thus follow both, an acid-dependent and acid-independent paths. The oxidation of [1,1 2H2]benzyl alcohol exhibited the presence of a substantial kinetic isotope effect ( kH/kD = 6.20 at 298 K ). This indicated the cleavage of a α-C-H bond in the rate-determining step. An analysis of the temperature dependence of the deuterium isotope effect showed that the loss of hydrogen proceeds through a concerted cyclic process. The rate of oxidation of BA was determined in 19 organic solvents. An analysis of the solvent effect by Swain’s equation indicated that though both the anion and cation-solvating powers of the solvent contribute to the observed solvent effect, the role of cation-solvation is major. The rates of the para and meta compounds, at 298 K, failed to exhibit a significant correlation in terms of Hammett or Brown's substituent constants. The rates were then subjected to analyses in terms of dual substituent parameter (DSP) equations. The rates of oxidation of the para-substituted benzyl alcohols show an excellent correlation with Taft's σI and σRBA values. However, the rates for the meta-substituted benzyl alcohols show an excellent correlation with σI and σR0. The polar reaction constants are negative indicating an electron-deficient transition state. Hence the overall mechanism is proposed to involve the formation of a chromate ester in a fast pre-equilibrium and then a decomposition of the ester in a subsequent slow step via a cyclic concerted symmetrical transition state, involving hydride-ion transfer, leading to the product. The first order dependence on alcohol may be accounted in terms of the small value of the formation constant of the ester intermediate. An another reaction mechanism accounting the acid-catalysis involve the formation of a protonated BIDC prior to formation of an ester intermediate which subsequently decomposes in a slow step leading to the product.
1640
66253
Solid-Liquid-Polymer Mixed Matrix Membrane Using Liquid Additives Adsorbed on Activated Carbon Dispersed in Polymeric Membrane for CO₂/CH₄ Separation
Abstract:
Gas separation by selective transport through polymeric membranes is one of the rapid growing branches of membrane technology. However, the tradeoff between the permeability and selectivity is one of the critical challenges encountered by pure polymer membranes, which in turn limits their large-scale application in. To enhance gas separation performances, mixed matrix membranes (MMMs) have been developed. In this study, MMMs were prepared by a solution coating method and tested for CO₂/CH₄ separation using a membrane testing unit at room temperature and a pressure of 100 psig. The fabricated MMMs were composed of silicone rubber dispersed with the activated carbon individually absorbed with various liquid additives including polyethylene glycol (PEG), Triton x-100, and cetyltrimethylammonium bromide (CTAB) coating on different porous supports such as polypropylene (PP), cellulose acetate (CA), and polyethersulfone (PES). This allows for the stabilization of the liquid additives from leakage. The MMMs will be performed and analyzed through their permeability and selectivity of the tested gasses. PEG emulsified silicone rubber MMMs showed superior gas separation on cellulose acetate membrane. However, the effect of activated carbon incorporation will also be studied.
1639
66008
Effects of Ethanolic Extracts of Datura metel L. on Liver Function of Male Albino Rats
Abstract:
The effects of ethanolic extracts of Datura metel on liver function of male albino rats were investigated in this study. The result showed an increase in the serum activities of ALT and AST. ALT and AST increased significantly (p < 0.05) in all the groups, except in group 4 where AST increased non-significantly (p > 0.05) compared with normal control. ALP decreased significantly in groups 3, 4 and 7, and non-significantly in group 5, but increased non-significantly in groups 2 and 6 compared to the control. Total protein levels increased non-significantly (p > 0.05) in groups 2, 4, 5 and 6, but reduced non-significantly in groups 3 and 7 compared with the normal control. The concentrations of total bilirubin and indirect bilirubin increased significantly (p < 0.05) in all groups administered Datura metel extracts when compared with the normal control. Direct bilirubin increased significantly (p < 0.05) in group 2 and 4, but increased non-significantly in groups 3, 5, 6 and 7 when compared with the normal control. Photomicrographs of some of the liver sections from rats administered different extracts (compared with the normal control) show evidence of inflammatory cellular infiltration within the central canal and centrilobular hepatocytes, central canal rupture, degenerating hepatocytes, vacuolations, perivascular necrosis and widened sinusoids. However, portal tract and periportal hepatocytes appear fairly intact. The results of this study show that despite the acclaimed medicinal effects of Datura metel, it could induce liver toxicity and can cause inflammatory cellular infiltration within some regions of the liver. However, low doses of the extracts encourage protein synthesis.
1638
65923
Investigation of Dispersion of Carbon Nanoparticles in Polymer Melt for the Fabrication of Functional Filaments
Abstract:
Nanocomposites have become more and more important as the implementation of nanoparticles in polymer allows additional functions in common industrial parts. Especially in the fabrication of filaments or fibres nanomodification is important, as only very small fillers can be added to the very fine fibres (common diameter is 20 µm, fine filament are 1 µm). Discharging fibres, conductive fibres, and many other functional fibres raise in their importance nowadays. Especially the dispersion quality is essential for the final enhancement of the filament propertied. In this paper, the dispersion of carbon nanoparticles in polymer melt is enhanced by a newly developed sonication unit of ITA and BANDELIN electronic GmbH & Co. KG. The first development steps of the unit fabrication, as well as the first experimental results of the modification of the dispersion, are shown. Special focus will be laid on the sealing of the new sonication unit as well as the positioning and equipment size when being implemented in an existing melt spinning unit. Furthermore, the influence on the thereby manufactured nano-modified filaments will be shown.
1637
65922
Development of a Nanocompound Based Fibre to Combat Insects
Abstract:
Pesticides, which harm crop enemies, but can also interfere with the human body, are nowadays mostly used for crop spraying. Silica particles (SiO2) in the nanometer and micrometer scale offer a physical way to combat insects without harming humans and other mammals. Thereby, they allow foregoing pesticides, which can harm the environment. As silica particles are supplied as a powder or in a suspension to farmers, the silica use in large scale agriculture is not sufficient due to erosion through wind and rain. When silica is implemented in a textile’s surface (nanocompound), particles are locally bound and do resist erosion, but can function against bugs. By choosing polypropylene as a matrix polymer, the production of an inexpensive agritextile with an 'anti-bug' effect is made possible. In the Symposium the results of the manufacturing and filament spinning of silica nanocomposites from a polypropylene basis is compared to the fabrication from nanocomposites based on Polybutylene succinate, a biodegradable composite. The investigation focuses on the difference between degradable nanocomposite and stable nanocomposite. Focus will be laid on the filament characteristics as well as the degradation of the nanocompound to underline their potential use and application as an agricultural textile.
1636
65882
Thermal Energy Storage for Concentrated Solar Power Plant: Thermocline Modelling and Experimental Validation
Abstract:
The paper presents a modelling analysis of the ENEA heat storage (Thermal Energy Storage - TES) system for concentrated solar power (CSP) plants with molten salts. It has been developed a heat exchange model able to perfectly reproduce the performance of the spiral heat exchanger installed in the thermal energy storage systems taken into consideration. Then, in order to analyse the fluidodymanic behaviour of the whole TES system both during the heat charging and discharging phases the aforementioned model has been used as subunit model in the thermo-fluid dynamic simulations assuming pure natural convection inside the device. Finally, the model has been validated through regression of experimental data collected on pilot plant located in ENEA research centre. The proposed mathematical model provides an analytic function of the thermocline profiles inside the TES system useful to evaluate the same system performance as well as to compare TES technology with other heat storage system used in CSP plants.
1635
65856
Preparation of Polymer-Stabilized Magnetic Iron Oxide as Selective Drug Nanocarriers to Human Acute Myeloid Leukemia
Abstract:
Drug delivery to target human acute myeloid leukemia (AML) using a nanoparticulate chemotherapeutic formulation that can deliver drugs selectively to AML cancer is hugely needed. In this work, we report the development of a nanoformulation made of polymeric-stabilized multifunctional magnetic iron oxide nanoparticles loaded with the anticancer drug Doxorubicin (Dox) as a promising drug carrier to treat AML. Dox@PMNP conjugates simultaneously exhibited high drug content, maximized fluorescence, and excellent release properties. Loading efficiencies and release rates for the as-prepared NPs were thoroughly investigated. Nanoparticulate uptake and cell death following addition of Dox@PMNP were then evaluated in four different types of human AML target cells: ML-2, HL-60, TF1-vRaf, and Mono-Mac-1, as well as on normal human SVG-p12 cells. While the unloaded NPs were not toxic to any of the cells, Dox@PMNP was found to be highly toxic to the four AML cell lines, albeit at different inhibitory concentrations, but showed no toxicity towards the normal cells. In comparison, free Dox showed significant potency concurrently to all the cell lines, suggesting huge potentials for Dox@PMNP as selective AML anticancer cargos. Time-course measurements by flow cytometry of the NP uptake showed significant uptake of Dox@PMNP by the different cell lines compared to that of unlabeled control NPs, with a detectable increase in the first 4 hrs post-treatment and increasing with time. Live confocal microscopy imaging confirmed that Dox is indeed delivered to the nucleus in relatively short periods of time, causing apoptotic cell death. These results indicate that the observed cytotoxic effects are dependent on the selective uptake of NPs by cells where Dox is released and then translocated to the nucleus exerting its cytotoxic action. Importantly, this targeted payload may potentially enhance the effectiveness of the drug in AML patients and may further allow physicians to image leukemic cells exposed to Dox@PMNP by MRI.
1634
65717
Estimation of Serum Levels of Calcium and Inorganic Phosphorus in Breast Cancer Patients
Authors:
Abstract:
Breast cancer is a type of cancer which is developed by the formation of a tumor on the breast. This tumor invades and causes different electrolyte imbalance. The present study was designed to measure the serum calcium and inorganic phosphorous levels and to check the frequency of hypercalcemia and hypophosphatemia in breast cancer patients. Serum calcium and phosphorous levels of fifty breast cancer women of 18-70 years of age group and fifty healthy women of same age group were measured by using semi-automated chemistry analyzer ( Humalyzer 3000, Human, Germany ). Significant variation in these levels was observed. The mean calcium value in BC patients was higher 9.398 mg/dl as compared to controls which were 8.694 mg/dl. Whereas the mean value of inorganic phosphorus level was lower 4.060 mg/dl in BC patients as compared to controls having 4.456 mg/dl. In this study, the frequency of hypercalcemia in Breast cancer patients was 10% i.e. only 10 out of 50 Breast cancer patients were suffering from hypercalcemia. Whereas the frequency of hypophosphatemia in this study was only 2 % i.e. only 1 out of 50 patients was suffering from hypophosphatemia. Thus it is concluded that there is a significant change in serum calcium and inorganic phosphorous levels in Breast cancer patients as the disease progresses. So, this study will be helpful for the clinicians to maintain serum calcium and phosphorous levels in Breast cancer patients and also preventing them from further complications.
1633
65669
Near-Miss Deep Learning Approach for Neuro-Fuzzy Risk Assessment in Pipelines
Abstract:
The sustainability of traditional technologies employed in energy and chemical infrastructure brings a big challenge for our society. Making decisions related with safety of industrial infrastructure, the values of accidental risk are becoming relevant points for discussion. However, the challenge is the reliability of the models employed to get the risk data. Such models usually involve large number of variables and with large amounts of uncertainty. The most efficient techniques to overcome those problems are built using Artificial Intelligence (AI), and more specifically using hybrid systems such as Neuro-Fuzzy algorithms. Therefore, this paper aims to introduce a hybrid algorithm for risk assessment trained using near-miss accident data. As mentioned above the sustainability of traditional technologies related with energy and chemical infrastructure constitutes one of the major challenges that today’s societies and firms are facing. Besides that, the adaptation of those technologies to the effects of the climate change in sensible environments represents a critical concern for safety and risk management. Regarding this issue argue that social consequences of catastrophic risks are increasing rapidly, due mainly to the concentration of people and energy infrastructure in hazard-prone areas, aggravated by the lack of knowledge about the risks. Additional to the social consequences described above, and considering the industrial sector as critical infrastructure due to its large impact to the economy in case of a failure the relevance of industrial safety has become a critical issue for the current society. Then, regarding the safety concern, pipeline operators and regulators have been performing risk assessments in attempts to evaluate accurately probabilities of failure of the infrastructure, and consequences associated with those failures. However, estimating accidental risks in critical infrastructure involves a substantial effort and costs due to number of variables involved, complexity and lack of information. Therefore, this paper aims to introduce a well trained algorithm for risk assessment using deep learning, which could be capable to deal efficiently with the complexity and uncertainty. The advantage point of the deep learning using near-miss accidents data is that it could be employed in risk assessment as an efficient engineering tool to treat the uncertainty of the risk values in complex environments. The basic idea of using a Near-Miss Deep Learning Approach for Neuro-Fuzzy Risk Assessment in Pipelines is focused in the objective of improve the validity of the risk values learning from near-miss accidents and imitating the human expertise scoring risks and setting tolerance levels. In summary, the method of Deep Learning for Neuro-Fuzzy Risk Assessment involves a regression analysis called group method of data handling (GMDH), which consists in the determination of the optimal configuration of the risk assessment model and its parameters employing polynomial theory.
1632
65655
Corrosion Behaviour of Nanostructured Beta Titanium Alloy Surface in Fluorides Containing Electrolytes
Abstract:
The process of implant fixation in the bone can be, depending on material’s surface properties, both long-term and complicated. Research aimed at applications of metallic biomaterials should be therefore focused on “bioactivation” of the implant surface. One of the possible ways is nanostructuring of the surface that means covering of the implant by a layer of nanotubes. Nanostructures have the strong effect on materials properties both from biological and also the electrochemical point of view. Studies on this topic are not too frequent, especially focused on interaction with fluoride ions effect, which is very important in the dentistry. The aim of this study is to compare the electrochemical behaviour of titanium beta alloy in polished and nanostructured surface states. Nanostructures were prepared in water based solution with ammonia sulfate and ammonia fluoride. Scanning electron microscope and photoelectron spectroscopy were used for surface characterisation. The layer adherence was tested in accordance with ASTM F1147 and ASTM C633. The electrochemical behaviour was studied in physiological solution and in physiological solution with fluoride ions. The experimental setup consisted of 12 h stabilisation of the open circuit potential, electrochemical impedance spectrum, and potentiodynamic curve measurement. Nanotubes with tubes diameter in the range from 15 nm to 50 nm and thickness 3 micrometers were successfully prepared. The adhesive strength was over 31 MPa which is sufficient for the layers used on implants. The photoelectron spectroscopy showed the increase of the alloying elements concentration in the nanostructured layer. The open circuit potential values of the nanostructured surface were nobler than that of polished surfaces. It was caused by the presence of thicker oxide layer on the surface. Impedance spectra of nanostructured surfaces were more complicated than in the case of polished samples. The equivalent circuits used for analysis had to be more complex. The impedance moduli were higher for polished surfaces; however, the impedance spectra shape points to a more capacitive behaviour of the nanostructured surface. One can assume that lower modulus of nanotubes was partially caused by increased exposed surface. The situation was different in the presence of fluoride ions. The nanostructure was increased corrosion resistance in the case when the combination of pH and fluoride content did not lead to the active dissolution of the material. Increasing aggressiveness of the environment which leads to polished alloy active dissolution caused just changes (not activation) of the nanostructured surface. Impedance spectra clearly showed the electrochemical reaction which takes place on nanotubes bottom. This was also confirmed by scanning electron microscope. Nanostructure lost adhesion because of the layer under corroding. The nanostructured layer with proper adherence was prepared. Exposure in physiological solution leads to the same model of interaction in the case of both systems. The corrosion behaviour of nanotubes was comparable with the polished surface in the physiological solution. Increasing corrosion resistance of nanostructured samples was observed in the electrolytes with fluoride ions. The work was carried out as a part of the 16-14758S project, which is financially supported by Czech Science Foundation.
1631
65646
Study of Lanthanoide Organic Frameworks Properties and Synthesis: Multicomponent Ligands
Abstract:
Coordination polymers, also known as metal-organic frameworks (MOFs) or lanthanoide organic frameworks (LOFs) have been reported due of their promising applications in gas storage, separation, catalysis, luminescence, magnetism, drug delivery, and so on. As a type of organic–inorganic hybrid materials, the properties of coordination polymers could be chosen by deliberately selecting the organic and inorganic components. LOFs have received considerable attention because of their properties such as porosity, luminescence, and magnetism. Methods such as solvothermal synthesis are important as a strategy to control the structural and morphological properties as well as the composition of the target compounds. In this work the first solvothermal synthesis was employed to obtain the compound [Y0.4,Yb0.4,Er0.2(dmf)(for)(H2O)(tft)], by using terephthalic acid (tft) and oxalic acid, decomposed in formate (for), as ligands; Yttrium, Ytterbium and, Erbium as metal centers, in DMF and water for 4 days under 160 °C. The semi-rigid terephthalic acid (dicarboxylic) coordinates with Ln3+ ions and also is possible to form a polyfunctional bridge. On the other hand, oxalate anion has no high-energy vibrational groups, which benefits the excitation of Yb3+ in upconversion process. It was observed that the compounds with water molecules in the coordination sphere of the lanthanoide ions cause lower crystalline properties and change the structure of the LOF (1D, 2D, 3D). In the FTIR, the bands at 1589 and 1500 cm-1 correspond to the asymmetric stretching vibration of –COO. The band at 1383 cm-1 is assigned to the symmetric stretching vibration of –COO. Single crystal X-ray diffraction study reveals an infinite 3D coordination framework that crystalizes in space group P21/c. The other three products, [TR(chel)(ofd)0,5(H2O)2], where TR= Eu3+, Y3, and Yb3+/Er3+ were obtained by using 1, 2-phenylenedioxydiacetic acid (ofd) and chelidonic acid (chel) as organic ligands. Thermal analysis shows that the lanthanoide organic frameworks do not collapse at temperatures below 250 °C. By the polycrystalline X-ray diffraction patterns (PXRD) it was observed that the compounds with Eu3+, Y3+, and Yb3+/Er3+ ions are isostructural. From PXRD patterns, high crystallinity can be noticed for the complexes. The final products were characterized by single X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), energy dispersive spectroscopy (EDS) and thermogravimetric analysis (TGA). The X-ray diffraction (XRD) is an effective method to investigate crystalline properties of synthesized materials. The solid crystal obtained in the synthesis show peaks at 2θ < 10°, indicating the MOF formation. The chemical composition of LOFs was also confirmed by EDS.
1630
65613
Validation of an Impedance-Based Flow Cytometry Technique for High-Throughput Nanotoxicity Screening
Abstract:
Background: New reliable and robust techniques to assess biological effects of nanomaterials (NMs) in vitro are needed to speed up safety analysis and to identify key physicochemical parameters of NMs, which are responsible for their acute cytotoxicity. The central aim of this study was to validate and evaluate the applicability and reliability of an impedance-based flow cytometry (IFC) technique for the high-throughput screening of NMs. Methods: Eight inorganic NMs from the European Commission Joint Research Centre Repository were used: NM-302 and NM-300k (Ag: 200 nm rods and 16.7 nm spheres, respectively), NM-200 and NM-203 (SiO2: 18.3 nm and 24.7 nm amorphous, respectively), NM-100 and NM-101 (TiO2: 100 nm and 6 nm anatase, respectively), and NM-110 and NM-111 (ZnO: 147 nm and 141 nm, respectively). The aim was to assess the biological effects of these materials on human monoblastoid (U937) cells. Dispersions of NMs were prepared as described in the NANOGENOTOX dispersion protocol and cells were exposed to NMs at relevant concentrations (2, 10, 20, 50, and 100 μg/mL) for 24 hrs. The change in electrical impedance was measured at 0.5, 2, 6, and 12 MHz using the IFC AmphaZ30 (Amphasys AG, Switzerland). A traditional toxicity assay, Trypan Blue Dye Exclusion assay, and dark-field microscopy were used to validate the IFC method. Results: Spherical Ag particles (NM-300K) showed the highest toxic effect on U937 cells followed by ZnO (NM-111 ≥ NM-110) particles. Silica particles were moderate to non-toxic at all used concentrations under these conditions. A higher toxic effect was seen with smaller-sized TiO2 particles (NM-101) compared to their larger analogues (NM-100). No interferences between the IFC and the used NMs were seen. Uptake and internalization of NMs was observed after 24 hours exposure, confirming actual NM-cell interactions. Conclusion: Results collected with the IFC demonstrate the applicability of this method for rapid nanotoxicity assessment, which proved to be less prone to nano-related interference issues compared to some traditional toxicity assays. Furthermore, this label-free and novel technique shows good potential for up scaling in directions of an automated high-throughput screening and for future NM toxicity assessment. This study was part of the FP7 EU 'NANoREG', NANO2021 'NorNANoREG', and EuroNanoMed II 'GEMNS' projects.
1629
65580
Synthesis of 5-Substituted 1H-Tetrazoles in Deep Eutectic Solvent
Abstract:
Contagious diseases enact severe public health problems and have upsetting consequences. The cyclic lipopeptides explained by bacteria Bacillus, Paenibacillus, Pseudomonas, Streptomyces, Serratia, Propionibacterium and fungus Fusarium are very critical in confining the pathogens. As the degree of drug resistance upsurges in unparalleled manner, the perseverance of searching novel cyclic lipopeptides is being professed. The intense study has shown the implication of these bioactive compounds extending beyond antibacterial and antifungal. Lipopeptides, composed of single units of peptide and fatty acyl moiety, show broad spectrum antimicrobial effects. Among the surplus of cyclic lipopeptides, only few have materialized as strong antibiotics. For their functional vigor, polymyxin, daptomycin, surfactin, iturin and bacillomycin have been integrated in mainstream healthcare. In our work daptomycin has been a major part of antimicrobial resource since the past decade. Daptomycin, a cyclic lipopeptide consists of 13-member amino acid with a decanoyl side-chain. This structure of daptomycin confers it the mechanism of action through which it forms pore in the bacterial cell membrane resulting in the death of cell. Daptomycin is produced by Streptococccus roseoporus and acts against Streptococcus pneumonia (PSRP), methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant enterococci (VRE). The PDB structure and ligands of daptomycin are available online. The molecular docking studies of these ligands with the lipopeptides were performed and their docking score and glide energy were recorded.
1628
65571
Antioxidant Property and Total Phenol Content of Rice Bran Oil from KDML105 and RD6
Abstract:
Rice bran oil (RBO) has been found to lower the level of serum cholesterol, has antioxidant and anti-carcinogenic property, and attenuate allergic inflammation. These properties of RBO are due to antioxidant compositions, especially, phenolic compounds. The purpose of this study is to determine total phenolic content (TPC) and antioxidant property of two white Thai rice; KDML105 and RD6 using solvent extraction method. The Folin-Ciocalteu colorimetric assay was used to determine TPC and scavenging of free radicals (DPPH) were used to determine antioxidant property expressed as EC50. The result showed that KDML105 had significantly higher (p < 0.05) TPC than RD6 with 9.8 mg gallic acid equivalent/ml of RBO. There was not significantly different of EC50 between two RBO verities. Further study should be performed on different pretreatments to increase the TPC and antioxidant property.
1627
65560
Development of Flipped Classroom in Chemistry on 'Acid-Base' for Enrichment Science Classroom Students
Abstract:
The study aimed to develop flipped classroom in Chemistry on ‘acid-base’ for high school students and study efficiency of students on academic achievement and problem-solving skills. The evaluating result from the experts showed that developed flipped classroom was ranked in high score level. The flipped classroom efficiency E1/E2 was higher than the criteria of 70/70. The flipped classroom was used by 24 students in grade 11 in the second semester of the academic year 2016 at Bodindecha (Sing Singhaseni) School. Sampling group was chosen using a purposive sampling approach. The results revealed that academic achievement and problem solving skills of students after studying flipped classroom was significantly higher at .05 level.
1626
65455
Choosing the Right Lignin for Phenolic Adhesive Application
Abstract:
Based on the source (softwood, hardwood or annual crop) and isolation method (kraft, organosolv, sulfite or pre-enzymatic treatment), there are significant variations in lignin structure and properties. The first step in using lignin as biobased feedstock is to make sure that specific lignin is suitable for intended application. Complete characterization of lignin and measuring its chemical, physical and thermal properties can help to predict its suitability. To replace 100% phenol portion of phenolic adhesive, lignin should have high reactivity toward formaldehyde. Theoretically, lignins with closer backbone structure to phenol should be better candidate for this application. In this study, a number of different lignins were characterized and used to formulate phenolic adhesive. One of the main findings was that lignin sample with higher percentage of hydroxyl-phenyl units was better candidate than lignin with more syringyl units. This could be explained by the fact that hydroxyl-phenyl lignin units have two available ortho positions for reaction with formaldehyde while in syringyl units all ortho and para positions are occupied, and there is no available site in lignin structure to react with formaldehyde.
1625
65375
A Competitive Microcystin-LR Immunosensor Based on Au@MIL-101 and Reduction Graphene Oxide
Abstract:
This study developed an electrochemical immunosensor for ultrasensitive detection of microcystins-LR in water. MIL-101, a porous metal organic frameworks (MOFs) material based on trivalent chromium skeleton were synthesized by hydrothermal synthesis method and loaded the Au nanoparticles to prepare Au@MIL-101 composite materials which were used as a marker to label anti MC-LR. The composite materials have strong catalytic properties to the oxidation of ascorbic acid. Anti-MC-LR was immobilized on glassy carbon electrode surface using electrodeposition graphene oxide (rGO) as a fixed matrix to construct a competitive microcystin-LR immunosensor. The electrochemical immunosensor display linear relationship in the range of 0.05 ng/mL -75μg/mL with linear correlation coefficient of 0.9951 and detection limit of 0.02 ng/mL (S/N=3). This sensor was used to detect microcystins-LR in the water sample. The recovery was 102.43%, which is satisfied. The good testing results indicate that sensor has a great prospect in practical application.
1624
65362
Dielectric Properties of PANI/h-BN Composites
Abstract:
Polyaniline (PANI), the most studied member of the conductive polymers, has a wide range of uses from several electronic devices to various conductive high-technology applications. Boron nitride (BN) is a boron and nitrogen containing compound with superior chemical and thermal resistance and thermal conductivity. Even though several composites of PANI was prepared in literature, the preparation of h-BN/PANI composites is rare. In this work PANI was polymerized in the presence of different amounts of h-BN (1, 3 and 5% with respect to PANI) by using 0.1 M solution of NH4S2O8 in HCl as the oxidizing agent and conductive composites were prepared. Composites were structurally characterized with FTIR spectroscopy and X-Ray Diffraction (XRD). Thermal properties of conductive composites were determined by thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). Dielectric measurements were performed in the frequency range of 106–108 Hz at room temperature. The corresponding bands for the benzenoid and quinoid rings at around 1593 and 1496 cm-1 in the FTIR spectra of the composites proved the formation of polyaniline. Together with the FTIR spectra, XRD analysis also revealed the existence of the interactions between PANI and h-BN. Glass transition temperatures (Tg) of the composites increased with the increasing amount of PANI (from 87 to 101). TGA revealed that the char yield of the composites increased as the amount of h-BN was increased in the composites. Finally the dielectric permittivity of 3 wt.%h-BN-containing composite was measured and found as approximately 17. This work was supported by Marmara University, Commission of Scientific Research Project.