Moses Abednego Ollengo

• PhD
• Managing Director at Dedan Kimathi University of Technology

The dire need for environmental conservation has spurred the exploration of novel approaches for developing biodegradable and sustainable materials sourced from natural origins, particularly for engineering applications and these include cellulose. Utilizing coffee husks, a waste product from coffee production, offers a sustainable source of cellul...

Heavy metals pollution of water poses a major environmental challenge due to its antagonistic effects. They are not biodegraded and tend to accumulate in human body to toxic levels linked to some health effects. Therefore, there is need for their removal in water. Technologies that exist such as membrane filtration are limited by their high operati...

The generation of electricity using solar energy is an effective system to overcome the current global energy crisis. In this regard, developing new semiconductor materials can be of great interest in overcoming the challenge of charge carrier recombination and, hence, improving the power conversion efficiency (PCE) in photovoltaic devices, particu...

In the past few years, graphene and graphene-based materials have received enormous interest from the scientific community due to their extraordinary mechanical, electronic, optical and electrochemical properties. The success of graphene applications highly motivates the exploration of other applications such as in designing of antennas, phase modu...

The banking industry has seen a revolutionary moment in adopting mobile banking technology in the last few years. The technology has contributed to many customers keeping off the banking hall for basic and routine transactions. This has largely been attributed to the convenience of mobile banking, including time management and increased privacy. Ho...

Perovskite solar cells (PSCs) are emerging efficient photovoltaic devices, with record-high power conversion efficiencies (PCE) of more than 25.5%. However, PSCs exhibit some drawbacks, such as poor stability upon exposure to moisture or humidity, ultraviolet (UV) radiation and heat, which in turn limits the device lifetime and performance. In addi...

Titanium (IV) oxide (TiO2) is used as a physical blocker of ultraviolet (UV) radiation in many skin-care products. Absorption of TiO2 through the skin is likely to interact with viable tissues because UV radiation absorption generates toxic reactive oxygen species such as hydroxyl radicals. Studies on the acute toxicity of TiO2 nanoparticles in mam...

Common methods of synthesizing metallic nanoparticles are chemical and physical. However, they are expensive and use toxic chemicals. Green synthesis is less costly and safer hence a potential alternative. Silver nanoparticles (Ag NPs) were synthesized using dichloromethane extract of Chrysanthemum cinerariaefolium and colour change from pale green...

The design and fabrication of electronic devices based on graphene nanomaterials are dependent on the tuning of Fermi levels. This can be achieved by doping graphene oxide (GO) with an electron-withdrawing (p-type) or electron-donating (n-type) species that causes changes in the electron density and enhances the electrochemical properties. In this...

The conversion of skin to leather involves structural, chemical and physical changes to the material. The changes to the material is often after every subsequent process that the skin goes through before getting to the final leather. The leather processing involves three sub stages; pretanning, tanning and post tanning. The aim of the study was to...

Tanning is the process by which raw skins and hides are converted to a durable and flexible material which is non-putrescible. Leather has good hydrothermal stability, good mechanical properties, and its resistance to chemical and biological degradation helps it to be used in various applications. Leather can be used for various purposes such as ma...

The aim of this study was to utilise the Nile perch fish skins which are usually a waste from fish filleting companies to make leather and then to determine its physical properties. The skins were processed into leather using chromium(III) sulphate. The physical properties of leathers were determined using standard IUP methods which include: Tensil...

The greatest challenge in graphene-based material synthesis is achieving large surface area of high conductivity. Thus, tuning physico-electrochemical properties of these materials is of paramount importance. An even greater problem is to obtain a desired dopant configuration which allows control over device sensitivity and enhanced reproducibility...

Water hyacinth plant is known to jam water bodies with thousands of tons of floating plant matter. In order to help in its control, it is important to explore ways to create value in its products especially the ones that can find use in water remediation. On the other hand rice husk is not waste anymore for its ash is rich in active silica. Thus, t...

The formation, characterization, and dye sensitized solar cell application of nickel(II), zinc(II) and cadmium(II) ferrocenyl dithiophosphonate complexes were investigated. The multidentate monoanionic ligand [S2PFc(OH)]⁻ (L1) was synthesized. The reaction between metal salt precursors and L1 produced Ni(II) complexes of the type [Ni{S2P(Fc)(OH)}2]...

The most frequently used counter electrode (CE) in dye‐sensitized solar cells (DSSCs) is platinum on fluorine‐doped tin oxide glass. This electrode has excellent electrical conductivity, chemical stability, and high electrocatalytic affinity for the reduction of triiodide. However, the high cost of metallic platinum and the poor electrochemical sta...

Approximately more than 80% of the global population depends on traditional medicine for their basic primary healthcare needs. Africa has a well-established history of botanicals use. These contain a vast array of compounds which can be used to treat various skin related conditions. The rationale for the use of traditional medicine in skin care ste...

Laggera alata is in the Asteraceae family, and. Clausena anisata is in the family of Rutaceae both plants have shown bioactivity against several diseases. Malaria is by far the most important insect transmitted disease. There is no so far vaccine to prevent infection caused by A. gambiae mosquito and the malaria parasite is continually developing r...

The photostabilizing ability of grape seed extract on three common sunscreen absorbers: 2-ethylhexyl-p-methoxcinnamate (EHMC), benzophenone-3 (BP3) and tert-butylmethoxy dibenzoylmethane (BMDBM), was investigated. Samples were exposed to simulated solar radiation and monitored by spectrophotometric and chromatographic methods. The chemical composit...

The plant; Laggera alata is in the Asteraceae family, and has been shown to have bioactivity against several diseases. Malaria is by far the most important insect transmitted disease and so far no vaccine claims to prevent infection transmitted by A. gambiae mosquito. The malaria parasite; Plasmodium falciparum is continually developing resistance...

Clausena anisata extracts are known to show bioactivity against several diseases here we report their larvicidal activity. Dried and ground 600 g of aerial parts of the plant C. anisata were sequentially extracted with solvents of increasing polarity, five fractions were obtained. The oils were obtained by hydro-distillation in a modified Clevenger...

Clausena anisata extracts are known to show bioactivity against several diseases here we report their larvicidal activity. Dried and ground 600 g of aerial parts of the plant C. anisata were sequentially extracted with solvents of increasing polarity, five fractions were obtained. The oils were obtained by hydro-distillation in a modified Clevenger...

Objective: The study concerned the synthesis of a novel photostabilizer based on benzylidenepentanedione chemistry and the evaluation of its potential in developing a broad-spectrum sunscreen formulation containing avobenzone. Methods: 3-(3,4,5-Trimethoxybenzylidene)-2-4-pentanedione (TMBP) was synthesized through a condensation reaction and inc...

Leaching of fluoride, a toxic element, from industrial wastes and fluoride minerals like fluorspar (CaF2) into ground water may cause significant contamination, which may require major treatment before use as drinking water. The present study described the removal of F-on bone char in batch studies as a function of co-existing mineral ions phosphat...

The deleterious effects of ultraviolet (UV) radiation on outdoor workers and sunbathers cannot be over emphasised. To combat photoaging, skin wrinkling, photo-dermatitis, and various forms of skin cancer associated with UV radiation, photoprotection is necessary. The most convenient mode of protection is the use of sunscreens, presented in various...

The photostability of avobenzone, 2-ethylhexyl-4’-methoxy cinnamate and benzophenone-3 in methanol mulberry extract was investigated. The effect of mulberry extracts on the photo absorption capacity of each sunscreen was studied by exposing the samples to simulated solar radiation. The photochemical transformations were then followed by standard sp...

Skin-lightening preparations intended to lighten the skin and remove heavily pigmented areas weaken the skin’s natural defence to ultraviolet (UV) radiation. The remedy has been the use of sunscreen agents either applied separately or incorporated in the skin-lightening products. Some of these agents are known to degrade in sunlight and hence offer...

Skin-lightening preparations intended to lighten the skin and remove heavily pigmented areas weaken the skin’s natural defence to ultraviolet (UV) radiation. The remedy has been the use of sunscreen agents either applied separately or incorporated in the skin- lightening products. Some of these agents are known to degrade in sunlight and hence offe...

Skin-lightening preparations intended to lighten the skin and remove heavily pigmented areas weaken the skin’s natural defence to ultraviolet (UV) radiation. The remedy has been the use of sunscreen agents either applied separately or incorporated in the skin- lightening products. Some of these agents are known to degrade in sunlight and hence offe...

Inorganic sunscreen absorbers in skin-lightening preparations

Laggera alata is in the Asteraceae family, and. Clausena anisata is in the family of Rutaceae both plants have shown bioactivity against several diseases. Malaria is by far the most important insect transmitted disease. There is no so far vaccine to prevent infection caused by A. gambiae mosquito and the malaria parasite is continually developing r...