Instrumental neutron activation analysis of different products from the sugarcane industry in Pakistan--part 1: essential elements for nutritional adequacy

Jaggery, brown sugar, white sugar, and molasses collected from the local sugarcane industry of Pakistan have been analyzed for essential elements in order to estimate their nutritional adequacy. Instrumental neutron activation analysis was used to determine Ca, CI, Co, Cr, Fe, K, Mg, Mn, Na, and Zn through sequential, short, medium, and long irradiation times. Maximum concentrations for most of these elements were determined in molasses, with lower concentrations determined in jaggery and brown sugar; white sugar contained trace amounts of all essential elements. Contributions to the weekly Recommended Dietary Allowance (RDA) values for the elements were estimated only for jaggery, brown sugar, and white sugar because molasses in Pakistan is not consumed as a dietary item. Jaggery contributes the highest percentages of Cr, Mg, Mn, and Zn, whereas the highest percentages of Cl, Fe, K, and Na can be acquired from brown sugar. The contribution of white sugar to the weekly RDAs for these elements is negligible, indicating that white sugar is a poor source of the essential elements. However, the introduction of molasses to the diet can contribute to an adequate intake of these elements.     

Study of the 208Pb(n, γ0)209Pb reaction between 0.8 and 7.7 MeV

The reaction ²⁰⁸Pb(n, γ₀)²⁰⁹Pb was studied from 0.8 to 7.7 MeV to investigate relative contributions of the compound-nucleus and direct and semidirect processes in this energy range. Compound-nucleus reactions dominate below about 5 MeV and semidirect processes above 6 MeV. The direct-semidirect (DSD) model with a complex particle-vibration coupling describes the experimental data in the giant resonance region. A relatively large imaginary term is necessary to obtain a good fit to the data indicating either that the reactions proceed to a large extent in more complicated ways than the simple two-step semidirect reaction or that the model has a serious defect in its present formulation. A second objective was to search for a possible excitation of the isoscalar E2 and the M1 giant resonances by measuring asymmetries around 90° in the angular distribution of the γ-rays. The results indicate no (or very weak) asymmetry effects.     

Citronellal cyclisation over heteropoly acid supported on modified montmorillonite catalyst: effects of acidity and pore structure on catalytic activity

Citronellal cyclisation to isopulegol is an important intermediate step in the production of menthol. Several heteropoly acids (PTA) supported on modified montmorillonite (MM) catalysts were synthesized and then tested in cyclisation reactions. The prepared samples were characterized by XRD, ICP-OES, FTIR, N₂ sorption, NH₃-TPD, pyridine adsorption, amine titration and FE-SEM techniques. Effects of post-treatment were studied on montmorillonite pore structure, acidity and catalytic activity. The catalytic activity and isopulegol selectivity improved with acid-treatment and PTA loading. The amount of Lewis acidity of montmorillonite was enhanced with acid-treatment and PTA impregnation. In cyclisation, highest catalytic activity (31.87 mmol cat g^?1 min^?1) was achieved with 96% isopulegol yield in the use of 20% PTA-MM catalyst. The highest catalytic activity and selectivity were obtained in the presence of higher acidity and strong Lewis acidic sites, whereas effects of pore structure blockage seemed minor. The catalytic activity further decreased with the loss of active acidic sites (L and B) due to PTA decomposition with calcination at a higher temperature.     

National intercomparison exercise, ZH-A for the measurement of hafnium and zirconium in zirconium ores

Summary A national intercomparison exercise was conducted to remove inconsistencies and improve analytical procedures in the measurement of hafnium and zirconium in zirconium ores. The ZH-A series of reference samples, prepared at the Pakistan Institute of Nuclear Science and Technology (PINSTECH), were used for this purpose. It was observed that measurement errors decreased with increasing Hf concentration (~298-17500 ppm) for most techniques, especially for AAS due to the sample preparation procedure required for this technique. Of all the tested techniques most reliable results were obtained with neutron activation analysis (NAA) for the measurement of Hf and Zr in such matrices.     

Effect of <Emphasis Type="Italic">Rol</Emphasis> Genes on Polyphenols Biosynthesis in <Emphasis Type="Italic">Artemisia annua</Emphasis> and Their Effect on Antioxidant and Cytotoxic Potential of the Plant

Flavonoids are famous for their antioxidant capacity and redox potential. They can combat with cell aging, lipid peroxidation, and cancer. In the present study, Artemisia annua hybrid (Hyb8001r) was subjected to qualitative and quantitative analysis of flavonoids through HPLC. Rol genes transgenics of A. annua were also evaluated for an increase in their flavonoid content along with an increase in antioxidant and cytotoxic potential. This was also correlated with the expression level of flavonoids biosynthetic pathway genes as determined by real-time qPCR. Phenylalanine ammonia-lyase and chalcone synthase genes were found to be significantly more highly expressed in rol B (four to sixfold) and rol C transgenics (3.8–5.5-fold) than the wild-type plant. Flavonoids detected in the wild-type A. annua through HPLC include rutin (0.31 mg/g DW), quercetin (0.01 mg/g DW), isoquercetin (0.107 mg/g DW) and caffeic acid (0.03 mg/g DW). Transgenics of the rol B gene showed up to threefold increase in rutin and caffeic acid, sixfold increase in isoquercetin, and fourfold increase in quercetin. Whereas, in the case of transgenics of rol C gene, threefold increase in rutin and quercetin, 5 fold increase in isoquercetin, and 2.6-fold increase in caffeic acid was followed. Total phenolics and flavonoids content was also found to be increased in rol B (1.5-fold) and rol C (1.4-fold) transgenics as compared to the wild-type plant along with increased free radical scavenging activity. Similarly, the cytotoxic potential of rol gene transgenics against MCF7, HeLA, and HePG2 cancer cell lines was found to be significantly enhanced than the wild-type plant of A. annua. Current findings support the fact that rol genes can alter the secondary metabolism and phytochemical level of the plant. They increased the flavonoids content of A. annua by altering the expression level of flavonoids biosynthetic pathway genes. Increased flavonoid content also enhanced the antioxidant and cytotoxic potential of the plant.     

Synthesis of novel Schiff base doped sol–gel silicas

Sulfonamide Schiff bases were doped uniformly in silica sol–gels prepared from liquid precursors by a fast and easy way at room temperature and processed to form xerogels. Schiff bases are efficient chelating agents, bioactive and catalytically active compounds. The structures of the newly synthesized Schiff base doped xerogels were elucidated by their physical (morphology, surface area, porosity), spectral (FTIR) and analytical (CHNSO/Si) data. The powder X-ray diffraction studies were carried out to confirm the formation of single phase. Characterization confirmed that Schiff base molecules are entrapped inside the pores as well as physically bound onto the silica surface. All Schiff base doped xerogels are stable mesoporous materials showing hydrophilic properties. Loadings of Schiff bases from 0.10 to 0.23 g/g of xerogel were obtained resulting amorphous materials. The doping of Schiff bases with xerogel caused change in surface area, pore volume and pore diameter of xerogel without damaging the main framework of siliceous skeleton. Morphology and colour of xerogel was also changed after doping. The entrapment of Schiff bases in xerogel caused increase in their decomposition temperatures. The final Schiff base doped xerogels show remarkable thermal stability.     

Electrochemical determination of some antidiabetic drugs for type 2 diabetic patients

Quantitative determination of rosiglitazone, pioglitazone, glimepiride and glyburide as antidiabetic drugs for type 2 diabetic patients was performed conveniently and economically using cyclic voltammetry (CV) and differential pulse voltammetry (DPV). Carbon paste (CPE) and glassy carbon (GCE) electrodes were successfully used as sensors for these drugs in Briton-Robinson (B-R) as buffer solution. The preparation of CPE and the GCE as ion selective electrodes is based on the construction of 10% standard drug ion pair with reineckate or tungstophosphate imbedded as electroactive material. Working standards were freshly prepared just before the assay by dilution from a 10⁻² mol L⁻¹ drug stock solution. At a scan rate of 100 mV s⁻¹ the cyclic voltammograms showed a well defined anodic peak with high selectivity. The DVP gave a reproducible well defined diffusion controlled peak for each drug at a scan rate of 10 mV s⁻¹. The oxidation peaks were used to determine the tested drug concentrations. The quantitative determination of the four drugs in their pharmaceutical preparations by the proposed electrochemical technique was found to be identical with the values obtained by the standard HPLC method. A mean % recovery of 100 ± 1 was obtained and the % relative standard deviation was 1.62 indicating the high precision of the method and the confidence in its repeatability. The proposed electroanalytical technique using either the CPE or the GCE is economic, selective and can be applied for both the qualitative and quantitative determination of the drugs in their pharmaceutical preparations, without special drug separation.     

Exp-function Method for Generalized Traveling Solutions of Master Partial Differential Equation

In this paper, we use the Exp-function method to construct the generalized travelling solutions of the master partial differential equation. This equation plays a very important role in mathematical physics and engineering sciences. The suggested algorithm is quite efficient and is practically well suited for use in these problems. The results show the reliability and efficiency of the proposed method.     

Study of seasonal variation and source characteristic of PM10 of Shanghai urban atmosphere using PIXE

This study is a one-year monitoring of the inhalable particulate matter (PM10) of Shanghai (from January 2006 to December 2006) to study PM10 pollution. Proton-induced X-ray emission (PIXE) was used to investigate the chemical elements in Shanghai PM10. The study finds seasonal variation in both mass concentration and of chemical elements in PM10. The results of the enrichment factor show that the chemical elements in the inhalable particles could be divided into two categories, soil elements from earth crust and anthropogenic pollution elements. The high enrichment factors suggest that anthropogenic activities were the dominant source for elements such as S, Cu, Cl, Zn, Pb and Br. Strong correlation of K, Ca, Fe and Ti, from factor analysis, indicates these elements coming from earth crust or soil, S, Zn and Pb from industrial pollution and/or traffic and Cl from coal combustion.     

Non-invasive imaging of shallow bubble columns using electrical capacitance tomography

This paper deals with application of non-invasive electrical capacitance tomography to study the hydrodynamics of shallow bed bubble columns. Two bubble columns with different height to diameter ratio were used. Air–kerosene system that represents dielectric two-phase mixture was investigated. The ECT provided good measurement of the gas holdup at different gas velocities compared to the classical pressure measurements. The ECT was able to provide the gas hold up and the bubble velocities distribution across the column diameter at different gas velocities. The study revealed that spatial gas holdup and bubble velocity distributions are sharp with parabolic shape in the small bubble column (H_D/D_C = 5). However, in the large bubble column (H_D/D_C = 4) the gas holdup and bubble velocity profiles were flatter indicating improvement in the mixing homogeneity and leading to well-mixed reactor. 3D graphical visualization of the flow regimes and transition points were also examined using the ECT. In the small bubble column flow regimes were heterogeneous to slugs flow especially at high flow rate, resulted in downward flow near the walls and imperfect mixing.