15 research outputs found

    Striding towards self sustainability using Aluminium from Tanzanian kaolin for combination Tanning system

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    Content: Sustainability is a key factor which control future leather manufacture. Developing several new technologies is one of the primary agenda for sustainability. However, developing countries are facing several challenges which not only limited to best practice technologies but also finding self sustainability in maximizing the available resources. In the present study, an attempt has been made to explore the potential resource of aluminium from kaolin of Pugu hills, Tanzania for combination tanning. Though, extraction of aluminium from several resources are available, there is limited literature pertaining to Tanzania resources. Moreover, the extracted aluminium is basified and studied for its tanning efficiency. Diffraction and vibrational spectroscopic studies were carried out to assess the confirmation of extracted aluminium. Combination tanning has been carried out with vegetable tannins and dialdehyde starch tanning chemicals, which are from natural resources. Leathers tanned with aluminum and wattle resulted with a shrinkage temperature of 118ÂșC as compared to Al-Dialdehyde starch leathers showed around 90-100ÂșC. Physical strength characteristics such as tensile, tear and grain crack strength met the standard norms. Grain surface of leathers are found to be smooth which has been confirmed through microscopic studies. The study provides a new insight on accomplishing self sustainability through available resources and manufacture of eco-friendly system. Take-Away: 1. Tanzania is endowed with massive kaolin rich in aluminium, which is potential for application in leather industry for sustainable development of leather industry 2. The combination tanning system using aluminium from Tanzania kaolin with wattle tannins or Dialdehyde starch imparts leather with both physical and organoleptic properties that meet the stipulated norms 3. This new tanning system provides new insight on ecofriendly tanning system for the sustainability of leather industry

    Fish bladder-based activated carbon/Co3O4/TiO2 composite electrodes for supercapacitors

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    This research article published by Elsevier B.V., 2019Cobalt oxide/titanium dioxide/activated carbon (Co3O4/TiO2/Ac) composite was synthesized using simple sol-gel method before annealing at 300 °C. Fish bladder derived porous carbon used for the composite was synthesized by pyrolysis followed by chemical activation. Both scanning electron microscopy (SEM) and X-ray diffraction displayed Co3O4 and TiO2 phases well embedded onto the carbon matrices. Cyclic voltammetry in 6 M KOH electrolyte demonstrated that the composite has an excellent specific capacity of 946 Fg-1 for Co3O4/TiO2/Ac as compared to Co3O4/Ac, TiO2/Ac, and Ac with specific capacitances of 845, 340, and 308 F g−1, respectively at 5 mVs−1. Impedance spectroscopy reveals that the composite has good capacitive behavior with a series resistance of 0.6 Ω. Besides, Co3O4/TiO2/Ac maintains 89.7% of the initial capacitance after 2000 cycles. This study shows that the synergistic effect of the metal oxides and the carbon in the composite can enhance capacitance for practical supercapacitor applications

    Antimicrobial dependence of silver nanoparticles on surface plasmon resonance bands against Escherichia coli

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    Nichrous G Mlalila,1,2 Hulda Shaidi Swai,1 Askwar Hilonga,3 Dattatreya M Kadam2 1School of Life Sciences and Bioengineering, Nelson Mandela African Institution of Science and Technology, Arusha, Tanzania; 2ICAR-Central Institute of Post-Harvest Engineering and Technology (ICAR-CIPHET), Ludhiana, Punjab, India; 3Department of Materials Science and Engineering, Nelson Mandela African Institution of Science and Technology, Arusha, Tanzania Abstract: This study presents a simple and trouble-free method for determining the antimicrobial properties of silver nanoparticles (AgNPs) based on the surface plasmon resonance (SPR) bands. AgNPs were prepared by chemical reduction method using silver nitrates as a metallic precursor and formaldehyde (HCHO) as a reducing agent and capped by polyethylene glycol. Effects of several processing variables on the size and shape of AgNPs were monitored using an ultraviolet–visible spectrophotometer based on their SPR bands. The formed particles showing various particle shapes and full width at half maximum (FWHM) were tested against Escherichia coli by surface spreading using agar plates containing equal amounts of selected AgNPs samples. The NPs exhibited higher antimicrobial properties; however, monodispersed spherical NPs with narrow FWHM were more effective against E. coli growth. The NPs prepared are promising candidates in diverse applications such as antimicrobial agents in the food and biomedical industries. Keywords: antimicrobial agent, bandwidth, full width at half maximum, nanoparticles, particle siz

    Effects of spray-drying on w/o/w multiple emulsions prepared from a stearic acid matrix

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    Nichrous Mlalila,1 Hulda Swai,2 Lonji Kalombo,2 Askwar Hilonga3 1School of Life Sciences and Bioengineering, Nelson Mandela African Institution of Science and Technology, Arusha, Tanzania; 2Materials Science and Manufacturing, Council for Scientific and Industrial Research, Pretoria, South Africa; 3Department of Materials Science and Engineering, Nelson Mandela African Institution of Science and Technology, Arusha, Tanzania Abstract: The goal of this study was to explore the effects of spray-drying on w/o/w double emulsions of methyltestosterone (MT) loaded in a stearic acid matrix. MT-loaded nanoparticles were formulated by a water-in-oil-in-water emulsion technique using 50, 75, and 100 mg of stearic acid, 2% and 3% w/v polyvinyl alcohol, 5% w/v lactose, and 0.2% w/v chitosan. The emulsions were immediately spray-dried based on an optimized model of inlet temperature and pump rate, and characterized for optimized responses with regard to particle size, polydispersity index, and zeta potential, for both emulsion and powder samples. Dynamic light scattering analysis shown that the nanoparticles increased in size with increasing concentrations of polyvinyl alcohol and stearic acid. Scanning electron microscopy indicated that the MT-loaded nanoparticles were spherical in shape, had a smooth surface, and were in an amorphous state, which was confirmed by differential scanning calorimetry. These MT-loaded nanoparticles are a promising candidate carrier for the delivery of MT; however, further studies are needed in order to establish the stability of the system and the cargo release profile under normal conditions of use. Keywords: double emulsions, nanoparticles, pump rate, spray-drying, testosteron

    Striding towards self sustainability using Aluminium from Tanzanian kaolin for combination Tanning system

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    Content: Sustainability is a key factor which control future leather manufacture. Developing several new technologies is one of the primary agenda for sustainability. However, developing countries are facing several challenges which not only limited to best practice technologies but also finding self sustainability in maximizing the available resources. In the present study, an attempt has been made to explore the potential resource of aluminium from kaolin of Pugu hills, Tanzania for combination tanning. Though, extraction of aluminium from several resources are available, there is limited literature pertaining to Tanzania resources. Moreover, the extracted aluminium is basified and studied for its tanning efficiency. Diffraction and vibrational spectroscopic studies were carried out to assess the confirmation of extracted aluminium. Combination tanning has been carried out with vegetable tannins and dialdehyde starch tanning chemicals, which are from natural resources. Leathers tanned with aluminum and wattle resulted with a shrinkage temperature of 118ÂșC as compared to Al-Dialdehyde starch leathers showed around 90-100ÂșC. Physical strength characteristics such as tensile, tear and grain crack strength met the standard norms. Grain surface of leathers are found to be smooth which has been confirmed through microscopic studies. The study provides a new insight on accomplishing self sustainability through available resources and manufacture of eco-friendly system. Take-Away: 1. Tanzania is endowed with massive kaolin rich in aluminium, which is potential for application in leather industry for sustainable development of leather industry 2. The combination tanning system using aluminium from Tanzania kaolin with wattle tannins or Dialdehyde starch imparts leather with both physical and organoleptic properties that meet the stipulated norms 3. This new tanning system provides new insight on ecofriendly tanning system for the sustainability of leather industry

    Striding towards self sustainability using Aluminium from Tanzanian kaolin for combination Tanning system

    Get PDF
    Content: Sustainability is a key factor which control future leather manufacture. Developing several new technologies is one of the primary agenda for sustainability. However, developing countries are facing several challenges which not only limited to best practice technologies but also finding self sustainability in maximizing the available resources. In the present study, an attempt has been made to explore the potential resource of aluminium from kaolin of Pugu hills, Tanzania for combination tanning. Though, extraction of aluminium from several resources are available, there is limited literature pertaining to Tanzania resources. Moreover, the extracted aluminium is basified and studied for its tanning efficiency. Diffraction and vibrational spectroscopic studies were carried out to assess the confirmation of extracted aluminium. Combination tanning has been carried out with vegetable tannins and dialdehyde starch tanning chemicals, which are from natural resources. Leathers tanned with aluminum and wattle resulted with a shrinkage temperature of 118ÂșC as compared to Al-Dialdehyde starch leathers showed around 90-100ÂșC. Physical strength characteristics such as tensile, tear and grain crack strength met the standard norms. Grain surface of leathers are found to be smooth which has been confirmed through microscopic studies. The study provides a new insight on accomplishing self sustainability through available resources and manufacture of eco-friendly system. Take-Away: 1. Tanzania is endowed with massive kaolin rich in aluminium, which is potential for application in leather industry for sustainable development of leather industry 2. The combination tanning system using aluminium from Tanzania kaolin with wattle tannins or Dialdehyde starch imparts leather with both physical and organoleptic properties that meet the stipulated norms 3. This new tanning system provides new insight on ecofriendly tanning system for the sustainability of leather industry
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