This study aims to estimate the quantity of healthcare waste categorically generated in four different healthcare in Dar es Salaam city namely, Muhim

The heterocumulenes carbon dioxide (CO(2)), carbonyl sulfide (OCS), and carbon disulfide (CS(2)) were treated with bis(2,2,5,5-tetramethyl-2,5-disila-1-azacyclopent-1-yl)tin {[(CH(2))Me(2)Si](2)N}(2)Sn, an analogue of the well-studied bis[bis(trimethylsilyl)amido]tin species [(Me(3)Si)(2)N](2)Sn, to yield an unexpectedly diverse product slate. Reaction of {[(CH(2))Me(2)Si](2)N}(2)Sn with CO(2) resulted in the formation of 2,2,5,5-tetramethyl-2,5-disila-1-oxacyclopentane, along with Sn(4)(μ(4)-O){μ(2)-O(2)CN[SiMe(2)(CH(2))(2)]}(4)(μ(2)-N═C═O)(2) as the primary organometallic Sn-containing product. The reaction of {[(CH(2))Me(2)Si](2)N}(2)Sn with CS(2) led to formal reduction of CS(2) to [CS(2)](2-), yielding [{[(CH(2))Me(2)Si](2)N}(2)Sn](2)CS(2){[(CH(2))Me(2)Si](2)N}(2)Sn, in which the [CS(2)](2-) is coordinated through C and S to two tin centers. The product [{[(CH(2))Me(2)Si](2)N}(2)Sn](2)CS(2){[(CH(2))Me(2)Si](2)N}(2)Sn also contains a novel 4-membered Sn-Sn-C-S ring, and exhibits a further bonding interaction through sulfur to a third Sn atom. Reaction of OCS with {[(CH(2))Me(2)Si](2)N}(2)Sn resulted in an insoluble polymeric material. In a comparison reaction, [(Me(3)Si)(2)N](2)Sn was treated with OCS to yield Sn(4)(μ(4)-O)(μ(2)-OSiMe(3))(5)(η(1)-N═C═S). A combination of NMR and IR spectroscopy, mass spectrometry, and single crystal X-ray diffraction were used to characterize the products of each reaction. The oxygen atoms in the final products come from the facile cleavage of either CO(2) or OCS, depending on the reacting carbon dichalogenide.

While policy and decision-makers are striving to enhance food security amidst maddening impacts of climate change, climate smart agriculture is thought of as a promising breakthrough for responding to climate change impacts in Tanzania and elsewhere in the world as it strives to increase food productivity; build resilience of agricultural systems to climate change impacts and reduce agricultural greenhouse gas emission. Studies show that agricultural sector is both, a cause and a victim of climate change. It significantly contributes greenhouse gases to the atmosphere. However, achieving climate change mitigation through agriculture without compromising food security is a huge policy and research challenge, some scientists say, it is practically impossible. This study sought to determine tradeoffs and preferences of smallholder farmers on the attributes climate smart agricultural practices, specifically modeling choices of smallholder farmers using choice experiment method. Upon estimating three different models, positive utilities were observed in high productivity, Moderate and low GHG emission as well as on moderate and high resilient farming systems. Smallholder farmers showed a complete disutility on low and moderate agricultural productivity, high GHG emission and low resilient farming systems. The models therefore justified the fact that, attaining more yield without a compromise in greenhouse gas emission reduction targets is a blue-sky dream. In order to concisely inform policy, more research on farmers' preference and tradeoff on the attributes is needed to establish a scientific and logical progression about the tradeoffs people are willing to make with regard to the attributes of climate smart agriculture practices.

Previous studies have shown that CO 2 can insert into divalent Sn and Ge bis(silylamides) to give mixtures of silylated isocyanates and bis(silyl)carbodiimides, albeit rather sluggishly. In order to more effectively utilize the divalent metal bis(silylamides) in synthesis, more active and selective reactions to form only isocyanates or carbodiimides were needed. We have now shown that the more electropositive Group 2 complexes react with CO 2 virtually instantaneously under the very mild conditions of room temperature and atmospheric pressure CO 2 . We have also demonstrated that CO 2 can react under high pressure directly with the solid Mg bis(silylamides) to produce an unusual, high melting point solid. Different products are obtained when the cyclic, tied-back complex Mg[N(SiMe 2 CH 2 ) 2 ] 2 (Et 2 O) 2 is used in place of Mg[N(SiMe 3 ) 2 ] 2 (THF) 2 . Various Zn bis(silylamides) can be designed to afford either the silyl isocyanate or the bis(alkyl)carbodiimide in near quantitative conversions in ∼100% selectivities. Lastly, we have shown that the tied-back Zn complex can react with CO 2 at room temperature and 4 atm CO 2 pressure to cleave CO 2 and generate a product containing a stable, [Zn 4 O] 6+ core with a bridging 4 -O atom.

This study aims to assess the parameters removal efficiency of waste stabilization ponds of Swaswa area in Dodoma municipality. The study was done by analysing nine parameters in groups of biochemical and nutrients parameters. One year (2010) analysis was done in monthly intervals from January to December. Some of parameters were analysed in situ while the rest are taken to Dar es Salaam for laboratory analysis where by the water samples were taken in 4 o C equipment for transportation. Results show very low removal efficiency for most of parameters from no removal at all to 26.7% (BOD 5 , pH, TDS, E.C, Total alkalinity, and Total hardness, NO 3 -N and PO 4 -P) from the influent to the final effluent. Only turbidity shows an excellent removal of 98.8%. The removal efficiencies were also compared to general removal efficiencies from other studies and find out results from this study are very low. This low removal efficiency may be due to incomplete construction of Swaswa ponds where the third stage of maturation is missing. This stage is essential for polishing water and nutrient as well as pathogen removal. There is need of frequent awareness campaign to a community for the reuse of wastewater for agriculture and its possible impacts. Ponds should be modified and addition of maturation ponds constructed. Further studies are required for pathogen removal assessment and impacts of reuse wastewater to the food crops.