Hydrazine Method Research Articles

A clinic-pathological research explored the significance of ascorbic acid and iron levels in serum and saliva in premalignant disorder patients at Kanpur, Uttar Pradesh.

Oral submucous fibrosis (OSMF), or OSMF, is a well-known, potentially premalignant condition of the oral cavity. Monitoring OSMF widespread effects necessitate interventions in at-risk individuals, ideally before the disease becomes aggressive. Ascorbic acid and iron, for instance, are significant micronutrients in the pathogenesis of OSMF. This study aimed to investigate the significance of ascorbic acid and iron levels in serum and saliva in patients with premalignant disorder (OSMF) and to correlate variations in ascorbic acid and iron levels with histopathological grading. The present study was conducted on 195 patients over a period of 10 months. These patients were divided into two groups, Group I (n = 88, Control), Group II (n = 107, clinically diagnosed and histopathologically confirmed cases of OSMF). Serum and salivary ascorbic acid were analyzed by the dintrophenyl hydrazine method, whereas serum and salivary iron were analyzed by the dipyridyl method. Paired t-test and Fisher test were used to compare between the mean and to find the level of significance P value. The serum and salivary ascorbic acid levels consistently decreased with the progression of histopathological grading of OSMF. Serum and salivary iron levels were also decreased in OSMF patients, and it came as significant. Excess collagen synthesis during OSMF may have been promoted with ascorbic acid and iron. As a reason, serum and salivary monitoring may be significant in detecting and diagnosing OSMF early on.

Potent anticancer effects of vitamin C and vitamin C-rich fruit extract (Citrus sinensis L.) on human lung cancer cells

Introduction: Studies have shown that synthetic agents are connected with some complications. This work was designed to study the effects of vitamin C and Citrus sinensis fruit extract (CSFE) on viability, DNA synthesis, and apoptosis stimulation in human lung cancer cells (COR-L105). Methods: The total contents of the phenolics, flavonoids, and ascorbic acid in CSFE were assessed through the Folin-Ciocalteu, aluminum chloride, and dinitrophenyl hydrazine methods, respectively. The cytotoxicity of vitamin C and CSFE on COR-L105 cells was evaluated by the cell viability assay. Measurement of the DNA synthesis was done through the BrdU solution assay. The expression levels of some apoptosis regulatory genes were also evaluated. Results: The total phenolic, flavonoids, and ascorbic acid contents of CSFE were 94.31 ± 2.27 gallic acid equivalents (mg/g) of dry extract, 63.26 ± 2.86 quercetin equivalents (mg/g) of dry extract, and 59 mg/L, respectively. The 50% cytotoxicity concentration (CC50) values of vitamin C and CSFE on cancer cells were 54.6 and 82.7.6 μg/mL, respectively. Vitamin C and CSFE dose-dependently declined the amount of DNA production in the cancer cells. The expression levels of caspase-3 and Bax genes were markedly (P < 0.001) elevated by vitamin C and CSFE, while they reduced the level of Bcl-2 gene (P < 0.05). Conclusion: The findings showed the potent anticancer effects of vitamin C and CSFE against human lung cancer cell lines. DNA synthesis reduction and apoptosis induction can be considered as possible mechanisms of action. However, further surveys are necessary to clarify the accurate mechanism and their efficacy.

Investigation of phenolic compounds, in vitro antioxidant and enzyme inhibition activities of methanol and aqueous extracts of different parts of Glaucosciadium cordifolium

The present study was designed to evaluate the biological potentials and phenolic composition of different parts of Glaucosciadium cordifolium, which is less investigated and known as a wild endemic species to Turkey. The antioxidant activity of the plant was determined using 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2'-Azinobis-(3-Ethylbenzthiazolin-6-Sulfonic Acid) (ABTS), iron chelating capacity, and a ?-carotene / linoleic acid emulsion assay. The total phenol and flavonoid contents of the plant were determined using the Folin-Ciocalteu and aluminum chloride methods, respectively. The study of the enzyme inhibition activity of the plant was carried out for acetylcholinesterase, butyrylcholinesterase, ?-glucosidase, ?-amylase, and tyrosinase. The antiglycation activity of the aqueous extract of the plant was evaluated using established methods such as browning, a Nitroblue-tetrazolium (NBT) assay, the 2,4-dinitrophenyl hydrazine (DNPH) method, a Congo red assay, and fluorescent Bovine Serum Albumin (BSA). The HPLC profiling of the phenolics revealed that 18 standard phenolic compounds were found in different amounts in various extracts of the plant parts. According to our bioactivity results, the methanol extract obtained from the flower parts of the plant contained higher amounts of phenolic compounds and flavonoids, which also demonstrated the highest DPPH radical scavenging activity. In addition, the methanol extracts obtained from the leaves and roots were found to be the most active extracts against the acetylcholinesterase enzyme, as well as moderately active against the tyrosinase enzyme. The antiglycation capacity of the extract followed this order: G. cordifolium leaves > stems > roots > flower. As a result, our study indicated that G. cordifolium extracts have strong antioxidant potential, good enzyme inhibitory effects and antiglycation potential. Further studies on G. cordifolium with in vivo bioassays need to be carried out to seek the importance of the plant in pharmaceutical techniques.

Low Plasma Ascorbate Levels in Type 2 Diabetic Patients With Adequate Dietary Vitamin C.

Background Dietary intake of antioxidative vitamin C plays a protective role in the prevention of oxidative damage in diabetics, demanding increased requirement of vitamin C. Hyperglycemia results in impaired uptake of vitamin C in the cell. The present study was conducted to compare the plasma ascorbate levels in type 2 diabetic patients and controls consuming adequate dietary vitamin C. Methodology Fifty consented type 2 diabetes mellitus (T2DM) patients who were on treatment with oral hypoglycemic drugs and consuming adequate vitamin C in diet were taken in the study and 50 healthy controls equitably matched for age, gender between 40 and 70 years, and dietary intake of vitamin C were compared. Dietary intake of vitamin C was estimated by a food frequency questionnaire. Subjects consuming more than 35 mg/d of vitamin C were included in the study. Fasting blood sugar was estimated by glucose oxidase and peroxidase method and estimation of ascorbic acid was done by using 2, 4 dinitro phenyl hydrazine method. Result The mean ± standard deviation levels of plasma ascorbate levels in diabetic subjects were 0.22 ± 0.12 mg/dL, which were significantly lower as compared with controls with plasma ascorbate level of 0.47 ± 0.15 mg/dL. In diabetic subjects, insignificant positive correlation was observed between these parameters with r -value 0.168 and p -value 0.245. Conclusion This study concludes that even with the recommended dietary intake of vitamin C low plasma ascorbate levels were found among T2DM patients, which necessitates increased demand and dietary advice to diabetic patients on consuming foods rich in vitamin C more than the recommended daily allowance.

Development of magnetically separable mesoporous N doped TiO2-SiO2 coated Fe3O4 nanomaterial as solar photocatalyst for environmental application

Present paper deals with the synthesis of visible light sensitive, easily separable mesoporous magnetic titania material having Fe3O4 in the core as solar photocatalyst. Core Fe3O4 was synthesized by two different methods for comparative evaluation. Top titania layer was found to be mesoporous thus providing more active sites. Synthesized materials were characterized by UV–vis, XPS, XRD, TEM and Raman. Core Fe3O4 prepared from Fe(II) and Fe(III) salts showed higher magnetic moment having nanosized particles. On the other hand, the hydrazine method resulted in the formation of tubular iron oxide having low magnetic moment. XRD and Raman spectra support the formation of porous anatase phase on the top and below SiO2 layer properly shielded magnetic core. The final magnetic moment of 7.8 emu in case of iron oxide obtained from Fe(II) and Fe(III) salts indicates that the magnetic separation by applying an external magnetic field is easy. Nitrogen doping of top titania layer increases the visible light absorption and photocatalytic efficiency. Comparative evaluation towards the photocatalytic decomposition of para-nitrophenol and methylene blue was carried out to observe the effect of N doping. The synthesized material is found to be stable and reusable for at least five times without any marked change in the catalytic activity and magnetic moment. Synergistic effect of mesoporosity, presence of oxygen vacancy and N doping on titania facilitates the higher rate of MB and p-NP degradation under visible light.

Effect of a dentifrice containing different particle sizes of hydroxyapatite on dentin tubule occlusion and aqueous Cr (VI) sorption.

BackgroundDentin hypersensitivity is a common negative oral condition that can be treated with dentifrice containing hydroxyapatite (HA). The study evaluated the effect of nano-HA dentifrice on plugging the dentinal tubules for an anti-sensitivity reaction compared to a dentifrice containing common-sized particles. Also, the adsorption capacity of different particle sizes of HA mixed in a dentifrice and which is the optimal particle size was considered.MethodsFourty premolar dentine discs and fourty molar dentine discs were randomly divided into 4 groups: distilled water group, ordinary dentifrice group and 80, 300 nm HA dentifrice group. Each dentin disc was brushed with a dentifrice twice daily at 7600 rpm under 100 g force for 2 mins for 7 consecutive days and divided into two parts, half of the dentin disc was detected by the scanning electron microscope (SEM) and energy dispersive spectrometer (EDS), the other half was brushed with distilled water and observed by SEM. One milliliter dentifrice solution (80 nm HA dentifrice, 300 nm HA dentifrice, ordinary dentifrice) was added to 50 ml potassium dichromate solution for 1, 14, and 28 d. The residual Chromium (Cr6+) concentration in the supernatant was measured by the diphenylcarbon phthalocyanine hydrazine method. The elemental constitution in the precipitate was detected by EDS. The Kruskal-Wallis test was used to analyze surface mineralization and different plugging rates of dentinal tubules. The absorption capacity of dentifrices were also evaluated by the Kruskal-Wallis test. ResultsThe plugging rate in the HA dentifrice group was higher than that in the ordinary dentifrice group, and the 80 nm HA dentifrice group showed the best result. The atomic percentages of Ca and P of 80 nm dentifrice group on the surface of dentinal tubules were the highest. The 80 nm HA dentifrice group showed the best adsorption and stable effect of Cr6+, followed by the 300 nm HA dentifrice group. The 300 nm HA dentifrice and the ordinary dentifrice showed desorption phenomenon.ConclusionsThe dentifrice containing HA, especially the 80 nm HA dentifrice, exerts good dentinal tubule occlusion and surface mineralization effect. This dentifrice was also a good adsorbent of Cr6+.

Fully integrated high-throughput methodology for the study of Ni- and Cu-supported catalysts for glucose hydrogenation

Abstract A high-throughput (HT) methodology was applied for the synthesis, characterization and catalytic testing of silica and alumina supported Cu- and Ni-based catalysts for glucose hydrogenation. A design of Experiment (DoE) approach was also used in all steps. The deposition and reduction of both metals was performed using the chemical reduction with hydrazine method. In total, 36 catalysts were synthetized, characterized and tested in 5 days. The amount of metal deposited on the support was chosen as the discriminative and determining parameter. The catalysts were tested at low temperature (130 °C) in the hydrogenation of glucose to sorbitol. The results showed that the chemical reduction-precipitation method could be performed using fully automatized robots. The deposition of the metals strongly depended on the nature of the support, the temperature of the reduction and hydrazine/H2O ratio. The maximum metal precipitation occurred at higher temperature (70 °C) and lower N2H4/H2O ratio (0.04 mol/mol) in both cases. The results clearly showed that glucose conversion is higher for the catalysts synthesized at 70 °C compared to the catalysts synthesized at 50 °C, irrespective of the metal precursors, supports and hydrazine/water ratios employed during catalysts syntheses. With a total timespan of around 5 days we showed that HT methods applied to all the steps (synthesis, characterization and testing) can significantly reduce the time needed to develop a new catalytic process.

Nutritional and mineral composition of selected green leafy vegetables

Green Leafy Vegetables (GLV) is essential for healthy life. The analysis of nutritional composition and some essential major elements such as calcium, magnesium, potassium and sodium of the leaves of Cardiospermum halicacabum, Premna latifolia, Delonix elata, Argyreia pomacea, Mollugo pentaphylla and Pisonia grandis were carried out using standard methods. The results ranged as follows; moisture (62.86 ±2.55 - 77.80 ±3.27%), ash (7.33 ± 0.38 - 12.49 ±0.22 %), fat (2.18 ±0.09 - 4.75 ±0.22 %), fiber (7.88 ±0.61 - 15.30 ±0.59 %), protein (0.53 ±0.04 -3.52 ±0.06 %) and carbohydrate (0.89 ±0.09 - 5.65 ±0.11%). Vitamin C content was determined using a well-established 2, 4-dinitrophenyl hydrazine method (DNPH). Vitamin C content of GLVs ranged from 134.50 ±2.61 mg/100g for D. elata to 12.43 ±3.44 mg/100g for A. pomacea. Total phenolic content was in the range of 4.28 ±1.2mg GAE/100g for M. pentaphylla and 46.07 ±3.42 mg GAE/100g for D. elata. The mineral elements were ranged as follows: Sodium (116.4 ±3.8 - 190.2 ±2.6 mg/100g), potassium (94.5 ±2.9 - 127.3 ±2.4 mg/100g), calcium (84.9 ±2.2 - 272.6 ±2.8mg/100g) and magnesium (28.3 ±2.5 - 103.6 ±4.2 mg/100g). The results suggest that the green leafy vegetables contain considerable amount of essential micronutrients in addition to the presence of high amounts of vitamin C. The results also indicate that the high intake of GLVs could provide nutritional requirements necessary for the normal growth thus giving adequate protection against diseases arising from malnutrition.

To Study The Serum Vitamin –D And Oxidative Stress Status In Rheumatoid Arthritis

Aim and objectives: Rheumatoid arthritis (RA) is a chronic autoimmune systemic disease characterized predominantly by synovial inflammation, leading to joint destruction. The study was undertaken to analyze the vitamin –D and oxidative stress status in Rheumatoid arthritis
 
 Materials and methods: The Study includes Patients diagnosed as RA by using RA factor within the age group of30 to 60 years and comprised of 20 age matched control group. To assess oxidative stress, serum Malonyldialdehyde (MDA) was by thiobarbituric acid method and antioxidant level was assessed by estimation of serum vitamin C by dinitrophenyl hydrazine method. And vitamin D total is estimated by chemiluminescent immunoassay.
 Results: There is a significant decreased level of vitamin -D in the RA patients (37.58±5.7ng/ml) as compared to healthy controls (58.5±5.6ngl/ml). There is a a significant increased levels of MDA in the RA patients (7.6±1.09) as compared to healthy controls (8.4±2.8). There is a significant decreased level of vitamin -c in the RA patients (0.6±0.3mg/dl) as compared to healthy controls (1.0±0.31mg/dl).
 
 Conclusion: Low levels of Vitamin D deficiency in RA patients is associated with inflammation which leads to Increased oxidative stress status , which may lead to connective tissue degradation leading to joint and periarticular deformities in rheumatoid arthritis.

NEW FLAVONOIDS FROM THE AERIAL PARTS OF POLYGONUM EQUISETIFORME SM (POLYGONACEAE)

<p><strong>Objective: </strong>The current study was to deal the isolation and identification of secondary metabolites from <em>Polygonum equisetiforme</em> and evaluation of antioxidant activity of its extract.</p><p><strong>Methods: </strong>The methanol-water extract (7:3) of the air-dried aerial parts of <em>Polygonum equisetiforme</em> was fractionated and separated to obtain the isolated compounds by different chromatographic techniques. Structures of these compounds were elucidated by UV and 1D⁄2D H⁄ C NMR spectroscopy and compared with the literature data. The crude extract was evaluated for <em>in vitro</em> antioxidant activity using the 2,2 diphenyl dipicryl hydrazine (DPPH) method.</p><p><strong>Results: </strong>Ten secondary metabolites were isolated from <em>Polygonum equisetiforme</em> in this study. Of which three new flavonoids named as 3,5,7,2’,5’ pentahydroxyflavone 3-<em>O</em>-b-D-glucopyranoside (1), 3,5,7,2’,5’ pentahydroxyflavone 3-<em>O</em>-b-D-glucopyranoside 8 C-sulphated (2) and quercetin 3-<em>O-β</em>-D-glucucorinde 6''-methyl ester 8-sulphated (3) as well as quercetin 3-<em>O-β</em>-D-glucucorinde methyl ester (4), quercetin 3-<em>O-</em>β-D-glucopyranoside (5), quercetin 7-<em>O-β-</em>D-glucopyranoside (6),<em> </em>quercetin(7)<sub>, </sub>myricetin (8), <em>P</em><sub>-</sub>methoxy gallic acid methyl ester (9) and gallic acid (10). The antioxidant potential of <em>P. equisetiforme</em> extract was evaluated by investigating it's total phenolic and flavonoid content and DPPH radical scavenging activity whereby the extract showed significant antioxidant activity (IC<sub>50 </sub>= 37.45 μg/ml). The total phenolic and flavonoid content was found to be 130.79±5.502 and 45.8±1.63 μg/ml, respectively.</p><p><strong>Conclusion: </strong><em>Polygonum equisetiforme</em> is a promising medicinal plant, and our study tends to support the therapeutic value of this plant as an antioxidant drug.</p>

Effect of oxidative pre-treatment on hydrogen spillover for a Ni/SiO2 catalyst

The chemisorption and hydrogenating properties of Ni/SiO2 catalysts prepared by the hydrazine method then calcined at 400°C with various times were investigated. Metal dispersion and activity in benzene hydrogenation increased with increasing calcination time whereas desorbed amounts of hydrogen significantly decreased. Dilution of a calcined sample by the support led to a sharp increase of both hydrogen storage by the support and catalytic activity. Metal dispersion and hydrogen storage capacity influenced the reaction mechanisms of hydrogenation of benzene which, therefore, is believed to occur on the metal phase or/and on the support by the hydrogen spillover mechanism. The metal active phase would be composed of an ensemble of metallic and oxidized nickel species.

CYTOTOXIC AND ANTIOXIDANT ACTIVITIES OF SECONDARY METABOLITES FROM PULICARIA UNDULATA

<p><strong>Objective:</strong><strong> </strong>To evaluate the <em>in vitro</em> cytotoxicity, antioxidant activities and structure-activity relationship of secondary metabolites isolated from <em>Pulicaria undulata</em>.</p><p><strong>Methods: </strong>The methylene chloride-methanol (1:1) extract of the air-dried aerial parts of <em>Pulicaria undulata</em> was fractionated and separated to obtain the isolated compounds by different chromatographic techniques. Structures of the isolated compounds were determined on the basis of the extensive spectroscopic analysis, including 1D and 2D NMR and compared with the literature data. The crude extract and the isolated compounds were evaluated for <em>in vitro</em> antioxidant activity using the 2,2 diphenyl dipicryl hydrazine (DPPH) method and cytotoxic assay using human breast cancer (MCF-7) and hepatoma (Hep G2) cell line.</p><p><strong>Results: </strong>Nine secondary metabolites were isolated from <em>Pulicaria undulata</em> in this study. Of which two terpenoidal compounds; 8-epi-ivalbin and 11β, 13-dihydro-4H-xanthalongin 4-<em>O</em>-β-D-glucopyranoside firstly isolated from the genus <em>pulicaria</em> and three flavonoids; eupatolitin, 6-methoxykaempferol, and patulitrin firstly isolated from <em>P. undulata</em>. 6-methoxykaempferol (IC<sub>50</sub> 2.3 µg/ml) showed the most potent antioxidant activity. The highest cytotoxic effect against MCF-7 and Hep G2 cells was obtained with eupatolitin (IC<sub>50</sub> 27.6 and 23.5 µg/ml) respectively. The structure-activity relationship was also examined and the findings presented here showed that 3, 5, 7, 4' and 3, 5, 4', 5'-hydroxy flavonoids were potent antioxidant and has cytotoxic activity.</p><p><strong>Conclusion: </strong><em>Pulicaria undulata</em> is a promising medicinal plant, and our study tends to support the therapeutic value of this plant as antioxidant drug and in the treatment of cancer.</p>

Fabrication and performance of solid oxide fuel cell anodes from core–shell structured Ni/yttria-stabilized zirconia (YSZ) powders

A core–shell structured nickel/yttria-stabilized zirconia (Ni/YSZ) powder was synthesized by the hydrazine method from an aqueous nickel chloride solution (NiCl2·6H2O) with YSZ particles, which were prepared by a hydrothermal technique. The cationic surfactant cetyltrimethyl ammonium bromide (CTAB) was added to form the core–shell structure. Nano-sized YSZ shell particles were homogeneously coated onto the surface of the spherical Ni core particles. It was found that the addition of CTAB was crucial for the formation of the core–shell structured Ni/YSZ powder. The size of the YSZ shell particles affected the morphology of the Ni/YSZ core–shell powder. Finer YSZ shell particles led to a denser coverage of the Ni core particle. During the heat treatment of the Ni/YSZ core–shell powder in air, the Ni was partly oxidized to NiO, and a three-dimensional network structure of NiO and YSZ was obtained. The enhanced electrical conductivity in the Ni/YSZ anode because of the core–shell structured powder was considered to be due to the improved connectivity between the Ni and YSZ particles. The maximum power densities and the polarization resistances of the Ni/YSZ anode from the core–shell structured powder were 0.38, 0.57, and 0.84W/cm2 and 1.01, 0.52, and 0.25Ωcm2 at 700, 750, and 800°C, respectively.

Characteristics and Preparation of Gas Sensor Using Nano-ZnO Powders

Nanorod ZnO and spherical nano ZnO for gas sensors were prepared by hydrothermal reaction method and hydrazine method, respectively. The nano-ZnO gas sensors were fabricated by a screen printing method on alumina substrates. The gas sensing properties were investigated for hydrocarbon gas. The effects of Co concentration on the structural and morphological properties of the nano ZnO:Co were investigated by X-ray diffraction and scanning electron microscope (SEM), respectively. XRD patterns revealed that nanorod and spherical ZnO:Co with a wurtzite structure were grown with (1 0 0), (0 0 2), (1 0 1) peaks. The sensitivity of nanorod and spherical ZnO:Co sensors was measured for 5 ppm CH4 and CH3CH2CH3 gas at room temperature by comparing the resistance in air with that in target gases. The highest sensitivity to the CH4 and CH3CH2CH3 gas of spherical nano ZnO:Co sensors was observed at Co 6 wt%. The spherical nano ZnO:Co sensor exhibited a higher sensitivity to hydrocarbon gas than nanorod ZnO.

The effect of reduction methods and stabilizer (PVP) on the properties of polyacrylonitrile (PAN) composite nanofibers in the presence of nanosilver

There are many studies which use different types of reduction methods that affect the final properties of composite material containing silver nitrate (AgNO3). The use of poly(N-vinylpyrrolidone) (PVP) in the composite also affects the final properties of composite material. However, as seen from the literature, it is difficult to find any studies focusing on polymer composite nanofibers reduced using different reduction methods and studies with different PVP loadings which are compared to each other, although it is very important to determine the most suitable reduction method and PVP loading for final composite properties. Thus, in this work, the effect of different reduction methods on polyacrylonitrile (PAN) composite nanofibers incorporating AgNO3 and the comparison of different amounts of stabilizer (PVP) are studied in detail to determine the most suitable reduction method and the effect of PVP loading on the structure and the properties of the final product. PAN composite nanofibers having different amounts of PVP are reduced by four different methods namely arc-sol method, hydrazine method, arc-web method, and reflux method and characterized by electrical conductivity, mechanical testing, and thermal and SEM analyses. It has been observed that the hydrazine method provides higher breaking strength, electrical conductivity, enthalpy, smallest diameter, and lower cyclization temperature (Tc) than other reduction methods. Presence of PVP results in an increase of breaking strength and cyclization temperature, a decrease of enthalpy and the electrical conductivity. While highest breaking strength was obtained by hydrazine reduction with highest PVP loading, highest electrical conductivity was obtained by hydrazine reduction without PVP. As a direct result of the incorporation of AgNO3 with or without PVP, insulator pure PAN (10−12 S/cm) becomes semi-conductive material (10−7 S/cm), which can be used as an antistatic material.

Comparative studies on performance evaluation of DI diesel engine with high grade low heat rejection combustion chamber with carbureted alcohols and crude jatropha oil

Abstract Search for renewable fuels such as vegetable oils and alcohols (ethanol and methanol) has become pertinent in the context of fossil fuel crisis and vehicle population explosion. The drawbacks associated with vegetable oils (high viscosity and low volatility) and alcohols (low cetane number) for use in diesel engines call for a hot combustion chamber, with its significant characteristics of higher operating temperature, maximum heat release, higher brake thermal efficiency and ability to handle the lower calorific value fuel. Investigations were carried out to evaluate the performance of a direct injection compression ignition engine with high grade low heat rejection (LHR) combustion chamber consisting of air gap insulated piston with 3 mm air gap with superni (an alloy of nickel) crown, air gap insulated liner with superni insert and ceramic coated cylinder head fueled with crude jatropha oil and carbureted alcohol (ethanol/methanol) with varied injection timings and injector opening pressures. Carbureted alcohol was inducted into the engine through a variable jet carburetor, installed at the inlet manifold of the engine at different percentages of crude vegetable oil at full load operation on mass basis. Comparative studies were made with engine with LHR combustion chamber with data of conventional engine with test fuels of diesel, crude vegetable oil and carbureted alcohol at recommended injection timing and optimized injection timing. Comparative studies were also made with methanol operation with data of ethanol operation on both versions of the combustion chamber with different operating conditions. Performance parameters, exhaust emissions and combustion characteristics were determined at full load operation of the engine with varied injection timings and injector opening pressures. Aldehydes were measured by the dinitrophenyl hydrazine (DNPH) method. Combustion diagnosis was carried out with a miniature piezoelectric pressure transducer, top dead center (TDC) encoder and special pressure–crank angle software package. The optimum injection timing was observed to be 32° bTDC with conventional engine while it was 29° bTDC for insulated engine with vegetable oil operation. The maximum induction of alcohol (methanol/ethanol) in conventional engine was found to be 35%, while it was 60% for the engine with LHR combustion chamber at recommended injection timing (27° bTDC). However, the maximum induction of alcohol was observed to be 55% with engine with LHR combustion chamber at its optimum injection timing. With maximum induction of methanol, at an injector opening pressure of 190 bar, engine with LHR combustion chamber at its optimum injection timing increased peak brake thermal efficiency by 3%; at full load operation brake specific energy consumption comparable, decreased exhaust gas temperature by 3%, decreased coolant load by 6%, volumetric efficiency comparable, increased formaldehyde levels by 30%, decreased acetaldehyde levels by 35%, decreased particulate emissions by 20%, decreased nitrogen oxide levels by 14%, increased peak pressures by 3% and maximum rate of pressure rose by 3%, when compared with ethanol operation on engine with LHR combustion chamber at its optimum injection timing.

Performance evaluation of medium grade low heat rejection diesel engine with carbureted methanol and crude jatropha oil

Abstract Vegetable oils and alcohols (ethanol and methanol) are important substitutes for diesel fuel as they are renewable in nature. However drawbacks associated with vegetable oils (high viscosity and low volatility) and alcohols (low cetane number) call for engine with hot combustion chamber with its significant characteristics of higher operating temperature, maximum heat release, higher brake thermal efficiency (BTE) and ability to handle the lower calorific value fuel. Methanol was inducted into the engine through a variable jet carburetor, installed at the inlet manifold of the engine at different percentages of crude vegetable oil at full load operation on mass basis. Crude vegetable oil was injected at near end of compression stroke. Performance was evaluated with engine with LHR combustion chamber consisting of air gap (3mm) insulated piston with superni (an alloy of nickel) crown and air gap insulated liner with superni insert with mixture of carbureted methanol and crude vegetable oil with varied injector opening pressure and injection timing. Comparative studies were made with crude vegetable oil operation on engine with LHR combustion chamber at similar operating conditions. Performance parameters and exhaust emissions were determined at various values of brake mean effective pressure. Aldehydes were measured by the 2,4, dinitrophenyl hydrazine (DNPH) method. Combustion characteristics were measured with top dead center (TDC) encoder, pressure transducer, console and special pressure–crank angle software package at full load operation of the engine. The optimum injection timing with crude vegetable oil operation on LHR combustion chamber was 29° bTDC. The maximum induction of methanol was 55% at recommended injection timing (27° bTDC), while it was 50% at optimum injection timing. With maximum induction of methanol, at an injector opening pressure of 190 bar, at recommended injection timing, engine with LHR combustion chamber increased peak brake thermal efficiency by 6%; at full load operation it decreased brake specific energy consumption by 2%, exhaust gas temperature by 16%, coolant load by 11%, volumetric efficiency by 6%, sound levels by 8%, particulate matter by 45%, NOx emissions by 46%, increased formaldehyde emissions and acetaldehyde emissions drastically, increased peak pressure by 23% and maximum rate of pressure rise by 17% when compared with crude jatropha oil operation at similar operating conditions.

Ciprofloxacin degradation from aqueous solution by Fenton oxidation: reaction kinetics and degradation mechanisms

Pharmaceutical wastewater from a large number of manufacturing units is extremely contaminated by ciprofloxacin (CIP), an antibiotic drug. In this work, aqueous CIP solution was treated by Fenton oxidation (FO). The effects of typical process parameters on drug mineralization have been reported. The optimal Fe2+/H2O2 molar ratio of 0.125 and pH of 3.5 were determined with 15 mg L−1 initial CIP at 25 °C temperature. Maximum CIP, COD and TOC removal of 74.4, 47.1 and 37.9% were obtained under the optimal conditions. The mean oxidation number of carbon determined in terms of COD and TOC values was in accordance with that from the oxidation number of individual carbon atom. The concentration of hydroxyl radicals was measured using the N,N-dimethyl phenyl hydrazine method using dimethyl sulphoxide as a probe. Thirteen fragments appeared in the mass spectra and the proposed mechanism explored the routes of daughter ion formation. The cleavage of the piperazine ring was more effective in CIP oxidation due to high nucleophilic character of lone pair of electrons present on the nitrogen atom. A simple 2nd order kinetic model was proposed for the oxidation of CIP and degradation products (DPs) with respect to OH˙ concentration. The rate constants of 3.13 × 103, 4.89 × 103 M−1 s−1 were estimated for CIP and DPs. The initial concentration of OH˙ was found to be 11.67 μM.

RELATION BETWEEN SALIVARY AND SERUM VITAMIN C LEVELS AND DENTAL CARIES EXPERIENCE IN ADULTS - A BIOCHEMICAL STUDY

AbstractThe aim of this study was to estimate the vitamin C levels in saliva and serum of caries free and caries active adults and to correlate the vitamin C level with DMFT index (D=decayed, m=missing, f=filled, t=teeth) index. The present study included eighty healthy adults who were divided into four groups; Control, Group- I, Group II and Group- III with a DMFT index 0, <3, <10 and > 10 respectively. Saliva and serum samples were collected from all the four groups. The vitamin C of saliva and serum was estimated by dinitro phenyl hydrazine (DNPH) method. One-way ANOVA was used to compare the vitamin C levels of saliva and serum. Only differences with 'p'value <0.05 were considered statistically significant. Saliva and serum vitamin C level decreases with increase in caries activity and is statistically significant suggesting the powerful antioxidant property of vitamin C.

Evaluation of micronutrient status in serum and saliva of oral submucous fibrosis patients: A clinicopathological study

Background:Oral submucous fibrosis (OSMF) is one of the most commonly occurring potentially malignant disorders in India and south East Asian countries where betel chewing is common practice. Iron and ascorbic acid are important agents for collagen synthesis.Aims:The aims of this study were to estimate the levels of iron and ascorbic acid in serum and saliva in patients with OSMF and to correlate change in levels of iron and ascorbic acid with the histopathological grading of OSMF.Materials and Methods:The study group comprised of 65 clinically diagnosed and histopathologically confirmed cases of OSMF; 21 age- and sex-matched controls were also enrolled in the study. Serum and salivary ascorbic acid were analyzed by the dintrophenyl hydrazine method whereas serum and salivary iron were analyzed by the dipyridyl method.Results:The serum and salivary ascorbic acid levels consistently decreased with the progression of histopathologiocal grading of OSMF. Serum and salivary iron levels were also decreased in OSMF patients, but this was not significant.Conclusion:Ascorbic acid and iron may have been used for the excessive collagen synthesis occurring during progression of OSMF. Hence, serum and salivary monitoring may play a crucial role in the early diagnosis and prognosis of OSMF.