Studies in the analysis of steel: electroanalytical determination of silicon and iron and colorimetric determination of boron

A study has been made of the suitability for steelworks chemical analysis of two instruments recently introduced by the Princeton Applied Research Corporation, by developing some new analytical applications of these instruments. Two procedures have been developed for the determination of silicon by differential pulse polarography using a PAR 174 Polarographic Analyzer. Both procedures are based on the reduction of β-12-molybdosilicate. The heteropoly acid is formed in the presence of methyl ethyl ketone and excess of molybdate is masked with citrate. Methyl ethyl ketone also stabilises the β-12-molybdosilicate and prevents its transformation to α-12-molybdosilicate. The first method was developed for determining silicon at levels above 0.02 μg.mlˉ¹. The formation of β-12-molybdosilicate at this level takes about 15 to 20 minutes. The second method was developed for determining nanogram amounts of silicon. [Continues.

Effect of Metal Ion Concentration on the Biosorption of Al3+ and Cr6+ by Almond Tree (Terminalia catappa L.) Leaves

The influence of initial metal ion concentration of the batch sorption of Al3+ and Cr6+ onto a low-cost biosorbent was investigated. The experimental results were analysed in terms of Langmuir and Freundlich isotherms. According to the evaluation using Langmuir equation, the monolayer sorption capacity obtained were 1.12mg/g and 2.67mg/g for Al3+ and Cr6+ respectively. The data further showed that sorption of the two metals onto the biomass increased with increase in initial metal ion concentration. The thermodynamic assessment of the metal ion – almond tree (Terminalia catappa L. biomass system indicates the feasibility and spontaneous nature of the process. ?Go was evaluated as ranging from -4.56 to – 6.64 KJ mol-1 and –4.03 to -6.10 KJ mol-1 for Al3+ and Cr6+ sorption respectively. The order of magnitude of the ?Go values indicates an ion exchange physiosorption process. Keywords: Adsorption, Almond tree, Heavy metals removal, Phytoremediation, water treatment

The Development of an Interactive Virtual Laboratory Simulation Software: A Case Study of Basic Physics Experiments

This paper presents the techniques for the development of a web-based interactive virtual laboratory simulation software with a case study of basic Physics experiments to determine the acceleration due to gravity. The virtual learning environment has been developed in the following manner, namely: 1). Determine the computer programs and applications to be used in the software using the hyper text mark-up language (html); 2). Design software content Based on java applets; 3). Model the laboratory interface, experimental materials, equipment and characters necessary for the virtual Physics laboratory; 4). Develop the virtual   laboratory; 5). Collect expert opinions about the virtual laboratory; 6). Finalize and test the virtual laboratory for simulation; and 7). Deployment of the virtual laboratory software for use by clients. The paper also presents the attributes related to the interface of the software and attributes related to the use of the virtual laboratory software as a material in education. The effectiveness of the proposed interactive virtual laboratory software is justified by its deployment for use by secondary school students with positive responses through interactions and questionnaires. Comprehensive techniques on how to compute the acceleration due to gravity and generate the corresponding predictive mathematical models for the experiments have also been presented together with the associated programs written in MATLAB. The limitations of the virtual laboratory simulation software and directions for further improvements are briefly highlighted. Keywords: Hyper text mark-up language (html), interactive virtual laboratory, Java® Applets®, Physics experiment

Cu(II) and Ni(II) Complexes of Sulfamethazine Mixed with Pyrimethamine: Synthesis, Characterization and Antimicrobial Study

Two novel mixed ligand metal –drug complexes of sulfamethazine and pyrimethamine were prepared using CuCl2.2H2O and NiCl2.6H2O.The complexes were characterized by elemental analysis, melting point determination, molar conductivity, FT-IR and Uv-Visible spectroscopy. Based on the analytical and spectra data the complexes were formulated as [M(SUFPRM)Cl2.XH2O,(SUFPRM)=Sulfamethazine+Pyrimethamine, M=Cu, Ni. And the complexes formed possessed octahedral geometry. In the complexes, sulfamethazine and pyrimethamine acted as bidentate ligand coordinating through the sulfonamide N-atom and the pyrimidinicN-atom. The complexes have been tested in vitro against a number of pathogenic bacteria[g+][Eschericha coli, Proteus specie, Klebsiella pneumonia, Salmonella typhi and Bacillus]by using paper disc method. Obtained results indicated that the metal complexes exhibited better antimicrobial activities as compared to the ligand. Keywords: Sulfamethazine, Pyrimethamine, metal-drug complexes, ligands, antimicrobial properties

A Hypothetical Database-Driven Web-Based Meteorological Weather Station with Dynamic Datalogger System

This paper proposes the development and implementation strategies of a hypothetical database-driven web-based meteorological (meteo) weather station with a dynamic datalogger system to provide up-to-the-minute real-time ground-based weather information online to any interested client. The meteo weather station will provide weather data/information for eight parameters namely: relative humidity; solar radiance; wind speed; wind direction; barometric pressure; temperature; nefobasimeter for monitoring and measuring cloud height, thickness and number of layers detection; and rainfall. The hypothetical design present techniques that can be used to capture and log meteo data in a dynamic relational database management system (DRDBMS) and implements a TCP/IP network server. The meteo weather information will be collected from sensors incorporated into measuring instruments and transmitted via 1–Wire network and stored in the TINI’s non–volatile static random access memory (NV-SRAM). The TINI processes and uploads the information over a TCP/IP network via a switch, router, common gateway interface (CGI), very small aperture terminal (VSAT) via an Internet service provider (ISP) to the Internet for any interested user in the world. More so, although the acquired data will be made available as they are being logged to both the Internet and the database (DRDBMS) but the data will be automatically deleted every 24 hours at 00:00G MT from the TINI’s NV-SRAM to free the memory for the next day data at the same 00:00G MT. As a result of this, the DRDBMS which is an object for data/information storage using the MySQL stores the meteo data/information which can be retrieved by any interested client on request. However, the request will be made possible via the use of web pages, where the each meteo data/information will be displayed and accessed using special user login codes (username and password) upon subscription. Keywords: DBMS, Dynamic datalogger, embedded systems, html, hypothetical weather station, JavaScript, meteorology, MySQL, PHP, TCP/IP protocol, Tiny INternet interface (TINI), WAMP server, web development

DMC and VMC Calculations of the Electric Dipole Moment and the Ground-State Total Energy of Hydrazine Molecule Using CASINO-Code

In this study quantum Monte Carlo (QMC) calculations of the electric dipole moment and ground-state total energy of hydrazine (N2H4) molecule using CASINO-code is presented. By employing the restricted Hartree-Fock (RHF) scheme, two QMC techniques were used in this work: variational Monte Carlo (VMC) and diffusion Monte Carlo (DMC) techniques. The optimization of the Slater-Jastrow trial wave-function was done using variance-minimization scheme. The simulations require that the configurations must evolve on the time scale of the electronic motion, and after equilibration, the estimated effective time-step be obtained. In this study, the electric dipole moment of N2H4 molecule was calculated using only the DMC technique. The result obtained gives an electric dipole moment value of 2.0 D, which is in good agreement with the experimental value of 1.85 D. Similarly, the ground-state total energy of N2H4 molecule was calculated using both VMC and DMC methods. It was observed that the result obtained from the VMC technique agrees very-well with the best theoretical value while the DMC technique gave a ground-state total energy value lower than all other theoretical values in literature, suggesting that the DMC result –111.842774 ± 0.00394 a.u., should be the exact ground-state total energy of hydrazine molecule. However, the results from this study are found to be precisely approaching the required order of chemical accuracy. Keywords: Hydrazine (N2H4), QMC, VMC, DMC, CASINO-Code.

Isolation and Identification of Fungi Associated with Raw Groundnut Seeds Sold at Four major markets in Port Harcourt Metropolis, Rivers State

The isolation and identification of fungi associated with raw groundnut seeds obtained from four major markets in Port Harcourt Metropolis was carried out in the Department of Plant Science and Biotechnology Laboratory (Pathology unit) in a Completely Randomized Design (CRD) using standard procedures. The identified fungal isolates include Aspergillus, Penicilium, Mucor, Rhizopus and Fusarium species. Aspergillus spp. with a mean value of 2.0 was the predominant fungi (P<0.05) identified followed by Fusarium spp. (1.1) and the least was Penicillium spp. (0.5). Mile three market recorded the highest (P<0.05) fungal incidence with a mean value of 1.44, followed by Mile one market (1.40) and the lowest was Rumuokoro market (0.70).  Large seeds were more prone to fungal contamination with a mean of 1.2 than small seeds (1.0). Similarly, unwholesome seeds recorded the highest (P<0.05) amount of fungal incidence with a mean of 1.7 than wholesome seeds (0.5). Public awareness should be carried out on personal hygiene of food vendors, market sanitation, storage conditions and management practices for improving the quality of raw groundnut seeds sold in Port Harcourt markets to reduce contamination level. Keywords: Raw groundnut, seed size, healthiness, market and Fungi

Investigating production parameters and impacts of potential emissions from soybean biodiesel stored under different conditions

Biodiesel production parameters and the impact analysis of the potential emissions from both soybean biodiesel and washing water stored in three different environmental conditions were investigated. The effects of the reaction temperature, methanol/oil mole ratio and catalyst concentration on biodiesel yield were considered. And the results showed optimum biodiesel yield of 99% obtained at 54°C, 7 methanol/oil mole ratio and 0.4 wt/wt % catalyst concentration. The potential emissions from both the biodiesel produced and washing water stored (for six weeks) in refrigerator (≤ 10°C), vacuum (50 kPa) and direct exposure to atmosphere were identified and quantified. Impact analysis of the emissions involved their categorization into: terrestrial acidification, freshwater eutrophication, human toxicity, terrestrial ecotoxicity, climate change and freshwater ecotoxicity. Freshwater ecotoxicity category had the most pronounced negative impact of the potential emissions with 5.237710-2 kg 1,4-DB eq. emissions in Atmosphere, 4.702610-2 kg 1,4-DB eq. emissions in Refrigerator and 3.966110-2 kg 1,4-DB eq. emissions in Vacuum. Climate change had the least effect of the emissions with 6.21410-6 kg CO2 eq. in Atmosphere, 3.9310-6 kg CO2 eq. in Refrigerator and 1.6710-6 kg CO2 eq. in Vacuum. The study showed that the order of preference of the storage environments of biodiesel is vacuum environment, refrigerated condition and exposure to atmosphere

Weekend versus weekday hospital deaths: Analysis of in‑patient data in a Nigerian tertiary healthcare center

Aim: This study aims at comparing weekday deaths to weekend deaths of in‑patients of a tertiary hospital in Nigeria.Materials and Methods: This is a 10‑year retrospective survey conducted at the Nnamdi Azikiwe University Teaching Hospital in which the death records of the hospital were accessed from the various wards and health records department to extract relevant data pertaining to the time of hospital death. Tests of statistical significance were done using Chi‑square test at 95% confidence intervals.Results: A total of 3934 deaths were recorded during the period of study. The ages ranged from a few hours to 94 years with a mean age of 38.5 years. The male to female ratio was 1.2:1. An average of 547 weekend deaths and 568 weekday deaths were recorded, giving a ratio of 0.96:1. A ratio of weekend to weekday death rate of 0.99:1 and 0.93:1 for the males and females, respectively was noted. The labor ward, followed by the intensive care unit (ICU) had the highest weekend to weekday death ratio of 1.72:1 (P = 0.0461) and 1.41:1 (P = 0.1440), respectively. Weekend deaths were less in the other wards, with the gynaecological ward having the least ratio of 0.63:1 (P = 0.7360).Conclusion: The rate of hospital deaths was generally found not to vary significantly over the weekends and weekdays in the hospital except for the labor ward which had significantly higher weekend to weekday death rates of 1.72:1. There is therefore need for confidential enquiry into the causes of hospital deaths, especially in the labor ward, in order to identify and prevent avoidable deaths.Keywords: Hospital deaths, in‑patients, weekend deathsNigerian Journal of Clinical Practice • Oct-Dec 2013 • Vol 16 • Issue

Past as global trade governance prelude: reconfiguring debate about reform of the multilateral trading system

This paper peers backwards into the history of the multilateral trading system and its development over the past half century as a means of considering what may lie beyond the horizon for the future of global trade governance. Its purpose is to underscore the necessity and urgency for root-and-branch reform of the multilateral trading system. It achieves this by comparing and contrasting the global trading system of 50 years ago with its modern-day equivalent and its likely future counterpart half-a-century hence. In so doing, the paper throws into sharp relief not only the inadequacies of global trade governance today but also the damaging consequences of not fundamentally reforming the system in the near future, with a particular emphasis on the past, present and future development of the world’s poorest and most marginalised countries