Atomic Absorption Spectroscopy and Physical Experiences in Morogoro, Tanzania

Geographical Variation in Mineral Composition of Tanzanian Ginger Roots Analysed by Atomic Absorption Spectroscopy

2026-01-21T11:39:24+00:00

Ginger is an herbaceous perennial native to south-eastern Asia, which thrives in mild climates. Due to its medicinal and health-promoting properties and high nutritional value, ginger has attracted growing interest among both dieticians and consumers. The aim of this study was to assess the composition of mineral elements in various ginger root samples. The study assessed the concentrations of the mineral elements Ca, Cu, Fe, Se, Mg, Zn, Na, P, K, and Mn in samples of ginger roots collected from Kilimanjaro, Morogoro, Iringa, Mbeya and Kagera regions. The collected ginger root samples were cleaned, oven dried, grinded to fine powder and diluted in concentrated acids. The solution samples obtained were analysed for the mineral elements by using an Atomic Absorption Spectroscopy (AAS) method. The mean concentrations of the analyzed elements were calculated and it was found that the ginger samples had higher composition of Calcium (Ca), Magnesium (Mg), Sodium (Na), Iron (Fe), and Potassium (K) followed by Manganese (Mn) then Zinc (Zn) and Copper (Cu) and lastly no amount of Selenium (Se) was detected since its mean concentrations were below the detection limit (0.50) mg/kg for the spectrometer used in this study. The statistical techniques such as mean, standard deviation, and ANOVA were employed to evaluate the data. Geographical relevance emphasises the importance of choosing ginger samples from five different Tanzanian locations and the data show how to comprehend with regional variations in minerals. The findings' nutritional or agricultural ramifications, particularly the high levels of calcium, magnesium, and iron and the lack of selenium, are given for healthy interventions.

Design, Construction and Evaluation of Performance of a Solar Cooker

2026-01-21T11:41:29+00:00

A solar cooker is a device which uses the energy and direct sunlight to heat, cook or pasteurise food or drink. Many solar cookers are presently in use and are relatively inexpensive, low-technology devices, although some are as powerful and as expensive as traditional stoves. This study aimed to showcase the design, construction and performance of a solar cooker. According to a survey, each family utilises two fully grown trees in a year. For this study, the design of solar cooking is strictly based on cost efficiency, easy availability and workability. The solar cooker was constructed using different materials. Each material served a specific function. A solar cooker box was constructed using rectangular panels and aluminium foil. The geometry of the cooker includes the simplest form of an angled panel surrounded by reflectors for enhanced efficiency. The cooker is surrounded by an insulating cardboard box with material which, when heated, retains heat so that it can be used when the sun is low. It is painted black on the outside so as to absorb all the radiation and emit none. The efficiency of this cooker is 89% when there is enough sunlight. The cooker can boil water up to 89℃ which is also a sufficient temperature to cook light foodstuffs and boil tea. Solar cookers operate by converting sunlight into heat through concentration, absorption, and heat trapping (greenhouse effect), and their performance is measured via standardised temperature studies to ensure efficient, clean, and sustainable cooking. The general methodology for solar cooking systems involves harnessing solar radiation and transferring that energy to food in an insulated environment. The specific methods vary by cooker type, such as Box Cookers, Panel Cookers, Concentrating Cookers (Parabolic/Dish), and Indirect Cookers. These decide the specific temperature values, duration, and materials used more precisely. The broader significance of the study is its contribution to sustainable energy or environmental protection. The solar cooker was constructed and tested for its performance by temperature-achievement measurements. It is potentially strong for reducing firewood dependency and environmental deforestation.

Assessment of Mercury and Arsenic Levels in Lemongrass at Kihonda and Mafisa in Morogoro, Tanzania

2026-01-21T11:44:38+00:00

As urbanisation and industrialisation continue to expand, there is a growing concern about the potential contamination of crops with heavy metals from various sources, including industries, infrastructures, pollution and agricultural practices. For instance, the quality and safety of lemongrass can be compromised by environmental factors, including the presence of heavy metals such as mercury and arsenic. The study aims to assess the presence and concentration of heavy metals in lemon grasses. These could have implications for the safety and quality of the lemon for various uses, including culinary and medicinal purposes. The research employs analytical techniques such as atomic absorption spectroscopy (AAS) to determine the levels of mercury and arsenic in the lemon grass samples. The findings of the study provide valuable insights into the environmental conditions and potential health risks associated with the consumption of lemon from Kihonda and Mafisa in Morogoro. High levels of heavy metals in food can cause serious health risks to consumers. The analysis of the concentration of arsenic and mercury in Lemongrass from Kihonda and Mafisa is compared. The concentration of arsenic in Lemongrass from Kihonda is slightly lower than that from Mafisa by 0.00186mg/kg. On the other hand, the concentration of mercury in Lemongrass from Kihonda is higher than that from Mafisa by 0.00493 mg/kg. According to studies, resulting from chronic exposure to heavy metals through contaminated food can lead to various health issues, including neurological disorders, gastrointestinal and kidney problems. It is necessary to know the level of heavy metals for safety. The study enables the readers to know the quality of the lemongrass for various uses, including culinary and medicinal purposes. The findings underscore the importance of continuous monitoring and management of soil and crop practices to ensure food safety to be in compliance with health guidelines. Immediate actions should include enhanced soil management and the adoption of improved agricultural practices.

Effect of Temperature on the Viscosity of Raw and Boiled Honey: A Study from Tabora, Tanzania

2026-01-21T11:46:43+00:00

Honey is a sweet-smelling fluid with a viscous character. Viscosity is a property of fluid by virtue of which a frictional force acts tangentially on the layers of the fluid in motion. The study aimed at investigating and determining the viscosity of the raw and boiled honey from Tabora, Tanzania, at constant and different temperatures. The method of Stokes’ law has been employed in the study. The physical properties, especially the viscosity of raw honey and boiled honey, were determined. Finally, the study revealed types of honey in raw or boiled form that can be used for medical, industrial, business, and food processing. Viscosity is a measure of a fluid's resistance to the movement of a mass through. Honeys viscosity varies with the amount of water, sugar and type. It is determined in this work that the variations in temperature change the viscosity of honey. The viscosity is lowered when honey is heated. The results of this study indicate that Tanzanian honey samples compare well with samples in many parts of the world. The quality of Tanzanian honeys has medicinal, nutritional, antioxidant and viscosity values. The temperature influence on viscosity in honey types is valuable for setting scientific benchmarks for distinguishing raw honey from heat-processed honey, as well as for food processing and packing. The physical properties of honey strengthen knowledge to support improvements in honey handling, storage, and industrial use.

Design and Evaluation of a Passive Solar Dryer for Small-Scale Food Preservation

2026-01-21T11:49:04+00:00

The use of solar energy has great potential for promoting energy efficiency and reducing the environmental impact of energy consumption in the environment. Solar drying is a very old but continuously explored technology that everyone can use to dry food products from meat, vegetables, cereals and dairy products. However, over time, with increased pollution to both the air and water, the sun drying has been deteriorating. Solar drying provides a safe and reliable environment for the quality of the dried products and their preservative duration. Despite the development of solar energy technologies, high costs and competition with inexpensive fossil fuels have historically limited their widespread adoption. Thus, interest was rekindled in the harnessing of solar energy for heating, cooling, the generation of electricity and other purposes. This study focuses on the design and construction of a solar dryer device intended for drying a variety of food products. The local and cheap materials were selected in the design so as to help local farmers reduce the cost of drying. The principle of the dryer allows lighter hot air to rise up the altitude and cool the surface. In the raising process, warm air comes in contact with the food slices and draws the moisture from them. The repeated cycle of this process makes it a very healthy, low-cost cost long-term drying mechanism. In thermodynamic terms, the sun’s power or heat is used to dry up the moisture content of the fruits or vegetables. The construction materials were wood, polyurethane glass, mild steel metal sheet and the trays. The optimum temperature of the dryer was 75°C with a corresponding ambient temperature of 28°C. The rapid rate of drying in the dryer reveals its ability to dry food items reasonably rapidly to a safe moisture level. The capital cost involved in the construction of a solar dryer is much lower compared to that of a mechanical dryer. Also, from the test carried out, the simple and inexpensive solar dryer was designed and constructed using locally sourced materials. The temperature inside the drier was found to be about three times than that of the outside atmospheric temperature. As per our experiment the maximum peak temperature inside the drying chambers was 75⁰C during the mid-day (1.00pm) and an average of 57⁰C in a fully sunny day (from 10:00am to 5:00pm). In seven (7) hours continuous drying in one full sunny day under the same climatic condition and in the same time the solar drier can remove maximum moisture contents from the food contents inside the drier for low moisture content food products. Experimental observation shows that the solar drier can be used as an alternative in case of food preservation and the efficiency is also acceptable. The people can make it on their homes especially in the developing countries where the energy demand is high.This chapter of the book is significant because it advocates the sustainable preservation of food using renewable energy. The creation of a passive solar dryer provides a cheap and environmentally beneficial way to lower post-harvest losses. It promotes further research in sustainable energy and agricultural technologies and helps ensure food security.

Influence of Temperature Variations on the Magnetic Field Strength of Ferromagnetic Materials

2026-01-21T11:51:31+00:00

Permanent magnets are made from materials that will remain magnetised and are hence able to maintain the magnetic field around them continuously. Each ferromagnetic material has a Curie temperature, above which it can no longer be magnetised. As the heat increases, the magnet's kinetic energy increases, making its molecules move faster, and they become more and more sporadic. The purpose of the study is to quantitatively analyse how increasing temperature influences the magnetic field strength of permanent magnets. The investigation of the effect of temperature on the strength of magnets is conducted, emphasising both the scientific and practical significance. The work provides knowledge to understand the properties of magnets and their strength when confronted with different temperatures. The experimental setup involves magnets which are used and tested in various temperature ranges. The measurement method involves compass deflection or magnetic field intensity. Once the results are obtained, further studies will be conducted on the permanent loss of magnetic performance in magnets heated above the Curie temperature. The methodology was based on observations of the effect of temperature on the strength of magnets. The deflections made on the compass needle on a magnet heated at different temperatures from 25°C to 98°C were recorded. The results revealed that a heated magnet has a reduction in magnetic field as the particles inside the magnet move at a faster speed and even sporadic rate. This environment misaligns the magnetic domains, resulting in a decrease in its magnetism. Moreover, various magnet materials respond differently to temperatures. Alnico has the highest service temperature, followed by SmCo, ceramic and then NdFeB. The general conclusions were that the effects of the temperature on the rate of the pull of a magnet are inversely proportional. That is, the temperature of a magnet increases, it becomes weaker, and as the temperature of a magnet decreases, it becomes stronger. The results of the testing show that the magnet at low temperature deflects the needle of the compass at a greater distance compared to the magnet at high temperature. It is the future interest to look at the arrangements for high-temperature electrical resistivity measurements of magnetic materials.

Assessment of Heavy Metals and Associated Human Health Risks in Catfish from Mafisa and Boma Road, Morogoro River

2026-01-21T11:53:54+00:00

Heavy metals, including lead (Pb), arsenic (As), mercury (Hg), cadmium (Cd), chromium (Cr), zinc (Zn), and copper (Cu), are toxic elements that cause significant environmental pollution and consequently health risk. This project aimed at finding the concentration of heavy metals in fish at Morogoro municipal by using an atomic absorption spectrometer (AAS) as the analytical technique. The study was conducted in two sites of the Morogoro River that passes the Mafisa area and the Boma road. The measurements were carried out for Lead(Pb), Mercury (Hg), Arsenic (As), Cadmium(Cd), Chromium(Cr), Zinc(Zn), Copper(Cu) from Industrial Area of Mafisa and results were 0.84,0.05,0.14,0.18,4.50,2.20 mg/kg while that of natural area of Boma Road were 0.12, Not detected,0.08,0.04,0.25,2.30,0.90 mg/kg respectively. The three values of Mafisa, Boma Road and FAO/WHO were compared and found to be completely different. It is concluded that consuming fish from polluted zones such as Mafisa may cause significant health hazards, especially due to long-term exposure to toxic metals like mercury and lead. This study evaluated the concentration levels of selected heavy metals in Clarias gariepinus collected from Mafisa and Boma Road. Assessment of the potential non-carcinogenic health risks to fish consumers in the region was conducted using risk indices such as Estimated Daily Intake (EDI), Target Hazard Quotient (THQ), Reference Dose (RfD) and Hazard Index (HI). HI for Mafisa exceeds 1.