Ahmed Y. Ali-Mohamed

Estimation of inorganic particulate matter in the atmosphere of Isa Town, Bahrain, by dry deposition

Abstract Inorganic particulate matter was sampled weekly during the period April 1985–April 1986 in Isa Town, Bahrain. The mean annual conductivity of water-soluble inorganic particulate matter was 59.99 μScm −1 ; pH 7.5; total suspended solid 0.06 gdm −3 ; total dissolved solid 63.79 ppm; total hardness as MgCO 3 86.80 ppm; as CaCO 3 208.05 ppm; Cl − 111.27 ppm; Na + 2.18 ppm; and NO 3 − 0.006 M. Each shows seasonal variations in concentration. The average aerosols maxima were recorded in summer. The total suspended solid (TSS) mode of aerosol displays some change, with a mean in winter of 0.039 gdm −3 and a mean value in summer of 0.044 gdm −3 . The aerosols data were influenced differently by some atmospheric parameters such as temperature, humidity, wind speed and direction.

Estimation of atmospheric inorganic water-soluble aerosols in the western region of Bahrain by ion chromatography

Abstract Dry fall aerosol particulate matter was collected in the western rural area of Bahrain. The collection was carried out using an open beaker trap of deionized water placed on the roof of an 8 m high building in seven villages representing the area under study. The water-soluble matter was analyzed for its chemical components by ion chromatography. The data obtained were in good correlation with the meteorological and surface features of Bahrain. The sizes of 108 randomly chosen particles, measured with a photomicrographic microscope, ranged between 6 and 230 μm. The latter value gives an indication that most of these particles were soil-derived.

Estimation of atmospheric inorganic water-soluble particulate matter in Muharraq Island, Bahrain, (Arabian Gulf), by ion chromatography

Inorganic particulate matter was sampled weekly during the period, from March to August of 1996 at eight different sites on Muharraq Island at height of ∼8 m above the ground level. Muharraq is the second most populated of the islands in the country (after the Bahrain island), but in terms of population per square kilometer, it is the most densely populated. Deposited aerosols were chemically analysed by ion chromatography and a comparison was made between these sites. The results were in good correlation with the meteorological and surface features of Bahrain.

Potentiometric determination of fluoride and iodide in natural and processed waters of Bahrain using ion-selective electrodes

Abstract To assess the natural availability of fluoride and iodide in Bahrain, natural and processed waters which included ground water, tap waters, Adari Lake water and streams and waters from reverse osmosis (RO), ion-exchange (IE), multistage flash desalination (MSF) and solar desalination (SD) plants, in addition to blended waters, were monitored for 3 months (Oct.–Dec. 1985). The fluoride ion concentration ranges from 0.45 to 1.51 ± 0.26 mg dm−3 in natural waters; 0.003 to 0.33 ± 0.016 mg dm−3 in the processed waters and 0.15 to 0.24 ± 0.095 mg dm−3 in the blended waters. As for the iodide ion, concentration ranges from 0.02 to 1.08 ± 0.07 mg dm−3 in natural waters; 0.01 to 0.02 ± 0.002 mg dm−3 in both processed and blended water.

Determination of inorganic particulates: (cationic, anionic and heavy metals) in the atmosphere of some areas in Bahrain during the Gulf crisis in 1991

Abstract Inorganic particulate matter was sampled weekly during the period March–May, 1991 at different sites at height of ∼6–9 m above the ground level. Deposited aerosols were chemically analyzed and a comparison was made between these sites. The percentage of tarry matter deposited on the airborne particulate matter was found to be 40% during the Gulf crisis compared to 5% prior to Gulf war (1985/86). Heavy metal analysis are also reported. The results were influenced differently by some atmospheric parameters such as temperature, humidity, rainfall, pressure and wind speed/direction.

Studies on the bacterial activity of cobalt(III) complexes. Part II. Cobalt(III) aminoacidato-complexes

SummaryCobalt(III) complexes of the typetrans-[Co(AA)2(ox)] (where AA = aminoacidato, gly = glycinato, sar = sarcosinato, DL-ala = DL-alaninato, L-ala = L-alaninato; ox = oxalate); [Co(L-val)2CO3] and DL-[Co(en)2sar]I2 where L-val = L-valinato, en = ethylenediamine) have been investigated for their bacterial activity againstEscherichia coli B using well-cultured techniques on EMB agar and in minimal glucose media. The activities decrease in the order:trans-(N)(+)K[Co(sar)2(ox)] >trans-(N)(+)K[Co(L-ala)2(ox)] >trans-(N)(−)K[Co (gly)2(ox)] >trans-(N)(+)K[Co(DL-ala)2(ox)] >trans-(N)(+)K[Co(gly)2(ox)] >trans(+)K[Co(DL-ala)2(ox)] >trans-K[Co(L-val)2CO3].

Diaqua bis-ethylenediamine and tetra aquaethylenediamine nickel(II) sulfate complexes

Interactions of equimolar concentrations of NiIISO4 with ethylenediamine solutions were performed using the method of continuous variations or Jobs method. A series of solutions containing different mole fractions of ethylenediamine:Ni2+(aq) (3:7, 4:6, 5:5, 6:4, 7:3, 8:2, and 9:1) were left to evaporate slowly at room temperature and resulted in the formation, for the first-time, of [Ni(OH2)4(en)]SO4, [Ni(OH2)2(en)2]SO4 and [Ni(en)3]SO4. These complexes were isolated and characterized by their elemental analyses and i.r. spectra.

SYNTHESIS, CHARACTERIZATION, AND MUTAGENICITY STUDIES OF COBALT(II I) BIS(PYRIDINE-2,6-DICARBOXYLATO) COMPLEX

ABSTRACT Attempts were made to synthesize and characterize Co(III) complexes with pyridine-2,6-dicarboxylic acid, pyridine-2,5-dicarboxylic acid, pyridine-3,5-dicarboxylic acid, and pyridine-3,4-dicarboxylic acid using the ‘Field-Durant Green’ solution as starting material (K3[(Co(III)(CO3)3]). Only the pyridine-2,6-dicarboxylic acid forms a stable complex with cobalt(III). Tests carried out on the complex proved it to be a non-mutagenic compound.

Bacterial activity of cobalt(III) complexes. Part IV: Diethylenetriaminemonoacetatocobalt(III) complexes

SummaryThe activities of the diethylenetriaminemonoacetatocobalt(III) complexes, [Co(en)(DTMA)]I2, [CoX2(DTMA)] and [CoCO3(DTMA)]·H2O (DTMA=diethylenetriaminemonoacetato or formally 3-amino-3, 6-diazaoctanato; en=ethylenediamine, X=Cl−, NO2−, NCS−) were studied onEscherichia coli B growing in a minimal glucose medium in both lag- and log-phases. Activities decrease in the order: [Co(NCS)2(DTMA)]> [Co(NO2)2(DTMA)]>[Co(en)(DTMA)]I2>[CoCl2(DTMA)] >[CoCO3(DTMA)]·H2O. The antagonistic activities of the complexes were also studied.

The preparation of trichlorotris(hydrogen-salicylato)rhodate(III) and tetra-μ-(hydrogen-salicylato)diaquadirhodium(II)

The preparation of a new example of a salicylato divalent rhodium complex, namely, tetra-μ-(Hsal)diaquadirhodium(II), and a new trivalent complex, the trichlorotris(Hsal)rhodium(III) ion are reported. The complexes were isolated and characterized by spectrochemical methods including FT-Raman and n.m.r. spectroscopies. The trivalent complex has a monodentate Hsal ligand bonded through a carboxyl oxygen with a facial configuration.