Production and characterization of bio-oil from algae using pyrolysis

Pyrolysis of the algae (chlorophyceac) was carried out using fixed bed reactor at 4500C. The mass balance of the pyrolysed algae were liquid fraction (oil) (10%), gaseous product (11%), solid product (char) (79%) and extent of conversion (21%. The proximate analysis of powdered sample was carried out in accordance with the official method of analytical chemistry (AOAC). The moisture content, ash content, volatile matter and fixed carbon determined were 3 + 0.33, 70.3 + 0.5, 6.3 + 0.3 and 20.2 + 0.07 respectively. The result obtained indicate that algae (chlorophyceae) could be used as feedstock for generation of pyrolysed oil which could probably be upgraded to fuel for both domestic and industrial purposes.

Effect of Blanching and Drying Temperatures on Physicochemical Properties of Red Dragon Fruit (Hylocereus polyrhizus) Peel Powder

Large production of red dragon fruit by-products, which are frequently discarded from food industry has become a major waste problem. Converting this waste into useful products with good physicochemical properties could solve the pollution issues. Thus, a study was carried out to investigate the effect of blanching and drying temperatures on physicochemical properties of red dragon fruit peel powder. Dragon fruit peel was pre-treated with hot water at 90 °C for 2 minutes before being dried in hot air oven dryer at 50 °C, 60 °C and 70 °C. Results showed that the powdered sample of blanched and dried at 50 °C had significantly higher fiber, water activity and moisture content than those of unblanched/blanched and dried at 60 °C and 70 °C. Result also showed that the colour of this powder was similar to the fresh dragon fruit peel. When dried at 50 °C, the unblanched and blanched powders exhibited a slightly higher water solubility index compared to those dried at 60 °C and 70 °C. Based on the evaluation of bulk and tapped densities, all powders having the Carr Index in the range of values between 20 and 28 thus can be categorised as slightly poor flowing. For all conditions studied, powder that was blanched and dried at 50 °C was the best condition as it contained the highest amount of fiber with good physicochemical properties.

Adsorption of Pb2+ from waste water using modified and unmodified plantain pseudo stem waste as adsorbent

This study was carried out to evaluate the potentials of plantain pseudo stem waste as adsorbent in the removal of Pb2+ from aqueous solution. Filament obtained from Plantain pseudo stem were dried, cut into chips and ground using electric grinder. The powdered sample obtained was soaked in ethanol for 24 hours and wash with water several times to remove the extractive component. It was then dried in the oven. Modification reaction was carried out on the powdered sample using Fenton reagent (Fe2+/H2O2). Both the modified and unmodified adsorbents were used for the adsorption of Pb2+ from aqueous solution. Factors considered were effect of contact time and effect of adsorbate (Pb2+) concentrations. The results revealed that in all the adsorption studies, the adsorption capacity of modified adsorbent was higher than that of the unmodified adsorbent. However, adsorption capacities increase with increase in contact time and decreases with increase in the adsorbate concentration.

Effect of low sintering temperature on the structural and magnetic properties of M-type strontium hexaferrite

A pure M-type strontium hexaferrite with nominal composition SrFe12O19 was prepared via modified conventional citrate precursor method. The basic idea of investigation was to improve the quality of hexagonal ferrite without high temperature sintering as these ferrites are generally known for high temperature sintering techniques. Thermogravimetric analysis (TGA/DTA) of powdered sample was carried out to identify the desired crystallization point suitable for the formation of M-phase. After dividing the sample into two equal parts, the prepared sample was sintered at two different temperatures, 800˚C and 910˚C. The properties of the material were investigated via using important characterization techniques, XRD, FESEM, FTIR, Raman spectroscopy (RS) and VSM respectively. The XRD confirmed the formation of M-phase along with some impurities of Fe2O3 and these results were strongly supported via both FTIR and RS. On increasing the sintering temperature, the average crystallite size was found to increase from 25nm to 33nm. The FESEM analysis confirmed the formation of densely packed grains some hexagonal platelets along with agglomerates. The magnetic parameters saturation magnetization (Ms), magnetic coericivity (Hc) and squarenes ratio (SQR) were investigated by using VSM. The value of Ms for ferrite sample sintered at 910˚C was found to be 92emu/g but at the same time the Hc value was found in the range of few hundreds of Oestered. This kind of behavior was due to the smaller grain size and the presence of impurity phase which was totally against the nature strontium hexaferrite. Such properties of M-type hexagonal ferrite was found very rare and procured to be an excellent candidate for switching devices, recording media, high frequency applications and many more.

NOVEL FINDINGS OF PHOENIX DACTYLIFERA, DATES FRUIT EARLY-STAGE HABABUK FOR PHYTOCHEMICAL SCREENING, ANTIOXIDANT AND CYTOTOXIC POTENTIALS

Objective: The present study aims to investigate the phytochemical constituents, antioxidant, and cytotoxic activity of the total ethanolic extract of the hababuk stage of date’s fruits Phoenix dactylifera (PDHE). Methods: Extracts PDHE obtained with shade dried and a powdered sample of hababuk stage of date fruits Phoenix dactylifera and subjected to phytochemical screening, in vitro antioxidant activity study by DPPH assay and ABTS assay, in vitro cytotoxic studies carried out for three different cell lines Lung Cancer (A549), Human cervical carcinoma (HeLa) and Breast Cancer (MCF)-7 cells by MTT method and brine shrimp lethality assay using standard procedure. Results: The phytochemical study revealed the presence of important constituents like alkaloids, glycosides, phenolic, flavonoids, carbohydrate, proteins, amino acids, terpenoids, steroids, and saponins. The antioxidant studies of the PDHE compared with standard showed very excellent results IC50 values for DPPH activity and nitric oxide. A good result was also shown by ABTS when compared with that of standard. The brine shrimp lethality assay is considered a useful tool for preliminary assessment of toxicity. The extract showed excellent LC50 value, which correlates with cytotoxicity studies previously established. The MTT study results using the three different cell lines compared with the standard doxorubicin, promising results obtained for HeLa cell lines when compared with other cell lines. Conclusion: Results obtained from the present work indicated that the hebabuk stage of date fruit is a promoising antioxidant and anticancer agent. Further study should be carried out to isolate the bioactive compound responsible for the activity.

Determination of the wetting angle using gas bubble method

Most of the technological processes of coal mining and primary processing (transportation, crushing, and enrichment) depend on the physical and chemical properties of the external surface of coal particles. When determining the wetting angle — the wettability characteristics of the coal surface — the method of preparing the working surface of the sample and the choice of the measurement procedure (a drop of liquid on a solid surface or fixing a gas bubble on the surface of coal placed in water) are of great importance. We present the results of determining the contact angle of wetting using an air bubble. The working surface was prepared by briquetting a powdered sample. Scanning electron microscopy and laser diffraction analysis of the particle size distribution were used for surface characterization and fractional analysis of carbon particles. It is shown that the contact angle of wetting depends on the particle size, mineral composition of coal, and pressing pressure. At the same time, when determining the wetting angle, the optimal particle size and pressing pressure of the briquette are <100 μm and ~500 MPa, respectively. The obtained results can be used to improve technologies for mining, conversion and dressing of coals.

BREAST CANCER ACTIVITY OF ISOLATED COMPOUND FROM TINOSPORA CORDIFOLIA AERIAL

Objectives: The present study undertaken to explore antioxidant and the cell line study of isolated compound from ethanol extract from Tinospora cordifolia belongs to the family Menispermaceae. Methods: The air dried powdered sample of aerial parts of T. cordifolia was extracted in a Soxhlet using five different solvents. Most active ethanol extracts were purified using silica gel column chromatography. Characterized the structure of the isolated compound using Fourier transform infrared spectrum, 1H nuclear magnetic resonance, and liquid chromatography–mass spectrometry studies. Antioxidant and anticancer activity of isolated compound was determined using 2,2-diphenyl-1-picrylhydrazyl and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. Results: Magnoflorine was isolated from most active ethanol extract from aerial parts of T. cordifolia which shows maximum antioxidant activity 64% at the tested concentration 500 μg/ml. The percentage of cell viability varied from 53.3% at the minimum tested concentration 3.12 μg/ml to 1.9% at the maximum tested concentration 100 μg/ml. Conclusion: The isolated characterized compounds would be useful to prepare plant-based pharmaceutical preparation to treat various diseases linked with human diseases.

Solid-State 2H NMR Study for Deuterated Phenylene Dynamics in a Crystalline Gyroscope-Like Molecule

Molecular rotors have earned substantial popularity in recent times, owing to the unique dependence of its crystalline properties on the rotational dynamics of the rotor. We have recently reported the synthesis and crystal structure of a phenylene-bridged macrocage as a gyroscope-like molecule in the crystalline state. The dynamics of the phenylene moiety was probed by solid-state 13C CP/MAS proton dipolar dephasing NMR spectroscopy. Herein, solid-state 2H NMR studies were performed to study the dynamics of the gyroscope-like molecule with a deuterated rotor in the crystalline state. A spectrum with a narrow line shape was obtained at 300 K. The facile exchange among three stationary states, which was observed by X-ray crystallography, was clearly confirmed. Additionally, a crystal-to-crystal phase transition that switches the motion of the rotor was observed in the DSC analysis of the powdered sample.

Safety assessment of oral administration of ethanol extract of Justicia carnea leaf in healthy wistar rats: hematology, antioxidative and histology studies

Background Consumption of medicinal plants has diverse therapeutic benefits and could also have toxic effect. Justicia carnea is a medicinal plant that is used conventionally as blood tonic from time immemorial in Nigeria. The aim of this study is to evaluate the safety of ethanol extract of J. carnea leaf assessing the hematology indices, organ antioxidant system and histology in healthy male wistar rats. Methods Powdered sample was extracted using absolute ethanol and concentrated to obtain a slurry paste of J. carnea ethanol extracts. Acute toxicity was determined in two phases using Lorke method. In subacute study, rats were randomized into six groups of five rats per group: Group 1 (control) received distilled water, group 2, 3, 4, 5, 6 received 50, 100, 500, 800 and 1200 mg/kg body weight of J. carnea ethanol extract once daily using oral gavage. At the end of 14th day of administration, rats were allowed to fast overnight, sacrificed to collect samples for biochemical analysis and histopathological examination. Results The LD50 of extract was greater than 5000 mg/kg body weight. Higher doses (> 500 mg/kg) of extract significantly (p < 0.05) increased RBC, hemoglobin and platelet compared to the control. Liver superoxide dismutase (SOD) activity was significantly (p < 0.05) increased at 1200 mg/kg while other tested doses caused no detrimental effect on glutathione, catalase, SOD and malondialdehyde level in liver and kidney. Histopathological examination of liver and kidney showed mild to severe pathological lesion in a dose dependent manner. Conclusions The results of this study suggests that ethanol extract of J. carnea leaf is relatively safe, could be beneficial in alleviating hematology related abnormalities without causing adverse effects on endogenous antioxidant system. However, caution should be taken as higher dose at 1200 mg/kg could cause noticeable tissue injury.

High Channel Density Ceramic Microchannel Reactor for Syngas Production

Solid oxide fuel cells can operate with carbonaceous fuels, such as syngas, biogas, and methane, using either internal or external reforming, and they represent a more efficient alternative to internal combustion engines. In this work, we explore, for the first time, an alumina membrane containing straight, highly packed (461,289 cpsi), parallel channels of a few micrometers (21 µm) in diameter as a microreformer. As a model reaction to test the performance of this membrane, the dry reforming of methane was carried out using nickel metal and a composite nickel/ceria as catalysts. The samples with intact microchannels were more resistant to carbon deposition than those with a powdered sample, highlighting the deactivation mitigation effect of the microchannel structure. The coke content in the microchannel membrane was one order of magnitude lower than in the powder catalyst. Overall, this work is a proof of concept on the use of composite alumina membrane as microchannel reactors for high temperature reactions.