Hydrothermally-calcined waste paper ash nanomaterial as an alternative to cement for clay soil modification for building purposes

It has been observed that clay soil cannot be used for building design, unless it is modified by firing or with cement. Either method of stabilization can adversely affect the environment and public health just like indiscriminate dumping or open burning adopted in developing countries as the prevalent disposal technique for waste papers. This paper sought to examine the feasibility of using assorted waste papers to derive an alternative stabilizer to Portland Limestone Cement for modification of clay soil into composite materials suitable for building design. Specifically, clay-based composites were fabricated at 0 %, 5 %, 10 %, 15 %, and 20% replacement levels by weight with cement, and then hydrothermally-calcined waste paper ash nanomaterial (HCWPAN). Water absorption, sorptivity, bulk density, thermal conductivity, specific heat capacity, thermal diffusivity, flaking concentration, flexural strength, and compressive strength were investigated for each of the fabricated samples. Irrespective of the stabilizing agent utilized, 10% loading level was found to be the optimum for possession of maximum mechanical strength by the samples. Only samples with the HCWPAN content were found to be capable of reducing building dead loads and improving thermal insulation efficiency over un-stabilized clay material, if applied as walling elements in buildings. Generally, it was revealed that the cement and HCWPAN have comparable influences on the properties of clay soil, thus indicating that HCWPAN could be utilized as an alternative stabilizer to cement. In addition, the preparation of HCWPAN was found to be more energy-saving than that of the cement

Impact of temperature difference on the features of spray deposited yttrium doped cobalt selenide (YCoSe) thin films for photovoltaic application

In this investigation, spray deposited yttrium doped cobalt selenide (YCoSe) thin materials were synthesized in soda lime glass and the impact of substrate temperature (140 oC, 160 oC, 180 oC and 200 oC) on their elemental composition, surface morphology, structural, electrical and optical properties were investigated using scanning electron microscopy-SEM X-ray diffraction –XRD, four-point probe and UV-VIS spectrophotometer respectively. The EDX plots of the deposited undoped and Y-doped cobalt selenide revealed the major elements: cobalt, selenium and yttrium. This confirms the deposition of CoSe and Y-doped CoSe thin materials. The morphology of undoped CoSe thin materials was very rough containing randomly oriented non-uniform thin particles while addition of Y dopant (0.1 mol%) at substrate temperature of 140 oC gave a homogenous distribution of compact rectangular-like nanograins. The XRD result shows that the films are cubic polycrystalline in nature and the film grown at substrate temperature of 180 oC was seen to give the most excellent crystalline quality and a preferential orientation along (111) direction. From electrical results it was observed that increase in substrate temperature increased the film thickness with decreased resistivity and increased conductivity. The optical properties were found to vary with substrate temperature despite the fact that the variation was not totally linear, as the film deposited at substrate temperature of 160 oC deviated from the linearity in all the optical properties. The energy band gap of the deposited samples ranges from 1.25 eV–1.75 eV. The materials produced could be used in the production of photovoltaic devices

Appraisal of Heavy Metal Contents in Commercial Inorganic Fertilizers Blended and Marketed in Nigeria

Abstract Human food chain toxicity has been shown to be influenced by application of inorganic fertilizers. Three samples of commercial inorganic fertilizers marketed in Nigeria were analysed for their heavy metal contents. The fertilizer samples used were N 15 P 15 K 15 (CF1), N 20 P 10 K 10 (CF2) and N 27 P 13 K 13 (CF3). Molybdenum (Mo) levels were the highest and Vanadium (V), Arsenic (As), Mercury (Hg) and Silver (Ag) were not detected by our analytical method. The concentrations of Mo in the CF1 (2, 570.0 mg/kg), CF2 (2,3000.0 mg/kg) and CF3 (1,340.0 mg/kg), were above the maximum acceptable concentration (20mg/kg) while CF1 (0.129 mg/ha/yr) and CF2 (0.115 mg/ha/yr) were above the maximum annual metal addition to soil (0.079 mg/ha/yr), as established by Canadian standard for fertilizers. Only CF1 (5.805 kg/ha) was above long-term cumulative assessment of metal addition to soil (3.57 kg/ha). Other heavy metals detected were Magnesium(Mg), Iron(Fe), Nickel(Ni), Zinc(Zn), Cadmium(Cd), Manganese(Mn), Cupper(Cu), Cobalt(Co), Lead(Pb), Chromium(Cr) and Boron(B). Cd and Pb mean concentrations of the fertilizer samples examined ranged from 2.84 to 11.32 mg/kg and 7.43 to 9.02 mg/kg respectively. Cd followed significantly (p<0.05) with phosphate percentage by weight of the inorganic fertilizers. Though the concentrations of these non-nutrient/toxic metals were below the recommended levels, it is important to encourage manufacturers to indicate their concentrations on the fertilizer labels in view of their health implications

Investigation of the inhibitive Properties of Irvingia gabonensisExtractan for the Corrosion of Aluminum Alloy (aa4007) in 1 m HCl

Communication in Physical Sciences, 2023, 9(3):193-202 Ajike Eziyi Emea* Lebe Agwu Nnanna, Orji Obinwa, Victor Emeka Ihuomah, Elizabeth Chinyere Nwaokorongwu Received: 13 March 2023/Accepted 29 May 2023 The corrosion efficiency of Irvingiagabonensis leaf extract for aluminium in 1MHCl media was investigated by gravimetric methods. The phytochemical analysis of the plant extract indicated the presence of saponin, alkaloid, flavonoid, and tannin which were considered effective against the corrosion of metals due to the commended chemical structures of the identified phytochemicals.  Observations of results from weight loss experiments showed a progressive enhancement of the inhibitory efficiency with extract concentration and decreasing temperature. The maximum observed inhibition efficiency of the plant extract was  98% under HCl concentration of 1.0 M and a reaction temperature of 318 K

Dual Solution Synthesis and Characterization of Sns:Zns Alloyed Thin Films and Possible Applications in Solar Systems and Others

Communication in Physical Sciences, 2023, 9(2):172-198 Authors: Elizabeth C. Nwaokorongwu, Daniel A. Asiegbu, Lebe Nnanna, Ugochukwu Joseph, Akpu Nwamaka and K.U.P. Okpechi Received: 12 March 2023/Accepted 18 May 2023/ Energy is required for the creation of wealth and sustainability of development. The importance of energy in economic development has been recognized historically but the equitable distribution of energy amongst the masses has generated great concern in recent times.  This study was conducted to investigate the influence of varying annealing temperatures on the synthesis and characterization of SnS:ZnS alloyed thin films for solar applications. SnS:ZnS alloyed thin films were successfully deposited on glass substrates using two solutions-based methods: electroless and SILAR. The deposited alloyed sulphides were annealed between (373-423) K using a master chef annealing machine. The crystallographic studies were done using X-ray diffractometer and scanning electron microscope which indicates that the samples are polycrystalline and have cubic crystal systems. Rutherford Back Scattering analysis confirmed the percentage of the elements of tin, zinc and sulphur in the alloyed sulphide thin films. The results of the findings revealed that alloyed materials were deposited. The deposited materials were uniform and adherent to the substrates. The structural properties show that SnS:ZnS are polycrystalline. The microstructure shows the optical micrograph of the deposited samples. The properties exhibited make the films good material for protective coating, window coating, galvanization of metal and non-metal surfaces to prevent corrosion, etc. These properties also enhanced the material suitability for photovoltaic (PV) in solar energy conversion, sensors for the detection of poisonous substances most especially in the Oil-producing areas, light emitting diode (LED) and flat panel displays for optoelectronic applications