Land Use Land Cover Change within Kakum Conservation Area in the Assin South District of Ghana, 1991-2015

Kakum Conservation Area is roughly 1187km2, extending over large portions of forest reserves in the Assin South District of Ghana. The district hosts the remaining biodiversity hotspots within highly fragmented rainforest of West Africa. Although the conservation has been gazetted as protected area, it has since been impacted by illegal chainsaw logging, expanding agricultural land use and built construction to meet the housing needs of the rapidly growing population of the district. However, there is paucity of data on the magnitude, rate and types of land cover change occurring in the district. This study seeks to address these by examining the magnitude, the rate and direction of change in land cover between 1991 and 2015. The study objective was achieved using supervised classification and post classification change detection of remotely sensed Landsat satellite imagery of the district taken in 1991, 2001 and 2015. The results show that, within the study period, the population of the area increased by 2.9%, thick forest decreased by 8.2km2, light forest increased by 5.3km2 and built environment increased by 2.9km2 per annum. These results are considered potential hindrance to sustainable development, including biodiversity conservation in the forest reserves and climate change mitigation in general. There is therefore need for measures to end deforestation and stimulate reforestation of the lost forest cover. The district needs to initiate an enquiry into the effectiveness of the current forest reserve management practices and sustainability of land use systems in the district

Thermoelectric prospects of nanomaterials with spin-orbit surface bands

Nanostructured composites and nanowire arrays of traditional thermoelectrics like Bi, Bi(1-x)Sb(x) and Bi(2)Te(3) have metallic Rashba surface spin-orbit bands featuring high mobilities rivaling that of the bulk for which topological insulator behavior has been proposed. Nearly pure surface electronic transport has been observed at low temperatures in Bi nanowires with diameter around the critical diameter, 50 nm, for the semimetal-to semiconductor transition. The surface contributes strongly to the thermopower, actually dominating for temperatures T < 100 K in these nanowires. The surface thermopower was found to be -1 T microvolt/(K^2), a value that is consistent with theory. We show that surface electronic transport together with boundary phonon scattering leads to enhanced thermoelectric performance at low temperatures of Bi nanowire arrays. We compare with bulk n-BiSb alloys, optimized CsBi(4)Te(6) and optimized Bi(2)Te(3). Surface dominated electronic transport can be expected in nanomaterials of the other traditional thermoelectrics.Comment: 18 pages, 3 figure

Assessing the Effect of Seedling Age and Time of Urea Supergranule Application on Rice Growth, Yield and Nitrogen Use efficiency

Nitrogen is the most limiting nutrient in tropical soils and nitrogen fertilizer application to rice is subject to losses. Good synchrony of nitrogen availability to crop’s need is a strategy to reduce losses and improve efficiency. A pot experiment was conducted to assess the effect of seedling age and time of urea supergranule application on rice growth, yield and nitrogen use efficiency. The experiment consisted of 10, 14, 21 and 28-day old seedlings and urea supergranule applied at 0, 7, 14 and 21 days after transplanting with a check treatment without nitrogen application. Results indicated significant effect of seedling age on growth, yield and nitrogen use efficiency. Highest grain yield, nitrogen uptake, agronomic use efficiency of nitrogen and nitrogen recovery efficiency were obtained with 10 and 14-day old seedlings, while the lowest values were observed for 28-day old seedlings. Urea supergranule applied at 7 or 14 days after transplanting gave the highest rice growth parameters while the lowest performances were obtained with urea supergranule applied at 0 and 21 days after transplanting. The interactive effect showed better growth, yield and nitrogen use efficiency of rice when urea supergranule was applied at 7 or 14 days after transplanting seedlings of 10 and 14-day old. The results suggested that even though application of urea supergranule at 7 and 14 days after transplanting increased rice yield over 0 and 21 days after transplanting, for the aged seedlings of 21 and 28-day old, the variation of urea supergranule application time could not compensate for the decrease of yield due to old seedlings transplanting

The utilisation of End-of-Life Plastics for the production of paver blocks: A waste management and disposal strategy

The volume of municipal solid waste in developing countries continues to grow, yet disposal and management have become significant challenges.&nbsp; As a result, a proper disposal strategy is required.&nbsp; The feasibility of making paver blocks from plastic waste for construction work was investigated in this study.&nbsp; Paver blocks manufactured from plastic waste (PP and HDPE) and sand in varied proportions were evaluated for compressive strength, water absorption, and abrasion resistance.&nbsp; Paver blocks were manufactured with plastic (PP and HDPE) to sand ratios of 30:70%, 40:60%, 50:50%, 60:40%, and 70:30%, or PP30, PP40, PP50, PP60, and PP70, and HDPE30, HDPE40, HDPE50, HDPE60, and HDPE70. &nbsp;The paver blocks were inspected after 28 days.&nbsp; Compressive strength, LA abrasion, and water absorption of paver blocks increased from 30% to 40% HDPE, then fell to 70%.&nbsp; As paver block PP content grew from 30% to 70%, abrasion and water absorption decreased.&nbsp; The compressive strength of PP paver blocks declined from 30% to 50% PP, then increased somewhat, and then fell to 60% and 70% PP.&nbsp; PP60 and HDPE40 paver blocks had the highest compressive strength, abrasion value, and water absorption.&nbsp; HDPE40 pavers have lesser water absorption and more abrasion than PP60 pavers.&nbsp; PP60 water absorption and abrasion were 0.53% and 11%; HDPE40 was 0.03% and 24.2%.&nbsp; PP60 and HDPE50 have compressive strength, abrasion resistance, and water absorption of 20.09 MPa, 11%, and 0.53%, respectively, and 13.06 MPa, 12.1%, and 0.03%

Prevalence of attention-deficit/hyperactivity disorder among primary school children in Oforikrom, Ghana based on the disruptive behavior disorders rating scale

OBJECTIVE: To determine the prevalence of attention-deficit/hyperactivity disorder (ADHD) among primary school children in Oforikrom, Kumasi, Ghana. METHODS: 10 of 35 primary schools in Oforikrom were readily available. Of 2000 children aged 5 to 13 years selected, 1540 (77%) of their parents/guardians consented to participate. Their parents/guardians and six teachers from each school were asked to complete the Disruptive Behavior Disorders Rating Scale to screen children for the presence of ADHD, oppositional defiant disorder, or conduct disorder. Children who displayed symptoms (pretty much or very much) in most related items as determined by parents and/or teachers were considered positive cases. RESULTS: The mean age of 1540 pupils was 9 ± 2.16 years. Most (31%) were primary 4 pupils. 5% of pupils displayed ADHD symptoms (attention deficit disorder subtype in 36%, hyperactivity disorder subtype in 27%, and combined subtype in 37%). Of them, 51% were male. Most (19%) of those who displayed the symptoms were in primary 5. CONCLUSION: The prevalence of ADHD among primary school children in Oforikrom was 5%. 51% of those with ADHD symptoms were male. Most (19%) of those with ADHD symptoms were in primary 5

Carbothermal Upgrading of the Awaso Bauxite Ore using Sawdust and Coconut Shells as Reductant

Ghana’s bauxite is exported in the raw state with no value addition. One way to achieve value addition is to carbothermally upgrade the ore into magnetic and nonmagnetic fractions, followed by separation using a magnet. This work investigates the carbothermal upgrading of the Awaso bauxite ore using reductant generated from locally available saw dust (SD) and coconut shells (CNS). Composite pellets of bauxite-reductant were prepared, air-dried and cured for 72 hours. The cured pellets were placed in a fire-clay crucible and heated in a custom-made gas-fired furnace for 30 minutes. The fired composite pellets were separated into magnetic and non-magnetic portions using a low intensity hand-held magnet. The various portions were then characterised using XRD, XRF and SEM analyses. XRD results showed magnetite as the predominant species present in the magnetic fraction whilst the non-magnetic fraction showed alumina as the predominant peaks along with some traces of unreduced hematite, silica, carbon and titania but no hercynite.  Keywords: Bauxite, Palm Nut Shells, Gas-Fired Furnace, Hercynite, Cha

Phosphorus adsorption, rice dry matter yield, and P use efficiency as influenced by phosphorus fertilizer rates in rainfed lowland soils in Togo

The study focused on improving phosphorus (P) fertilizer recommendation in rainfed lowland rice soils in Togo. Phosphorus adsorption was conducted on four soils to determine their P adsorption characteristics and standard phosphorus requirement (SPR). The adsorption maximum ranged from 143 to 200 mg P/kg. The amount of P adsorbed range from 62.70 to 74.85 mg P/kg. Greenhouse experiment was conducted to determine rice response to phosphorus rates based on the SPR values, and to assess rice P uptake and use efficiency. Five phosphorus rates, Control: 0 mg P kg−1, P recommended rate (RR): 5 mg P kg−1, 4 × RR: 20 mg P kg−1, 50% SPR and 100% SPR were used. Results indicated no significant difference between the Control treatment and the P recommended rate (RR), and between the 50% SPR and the 100% SPR with reference to shoot dry matter yield. P uptake and P use efficiency were significantly and positively influenced by the various P fertilizer rates. From the study, the blanket P recommended rate is inappropriate, however, site-specific P fertilizer rate of 50% SPR may be recommended to improve rainfed lowland rice yields in Togo

Effects of Harvest Time and Storage Form on Insect Population and Damage of Maize

The aim of this study was to determine the effects of harvest time and storage form on population levels of insect pests and their damage on stored maize. Maize was cultivated on a total land area of 19 x 23m2 during the major season (April to August 2020) and minor season (September to December 2020). Maize was harvested at three stages; early harvest, mid harvest and late harvest. Harvested maize was stored in three ways; husked, de-husked and shelled. Analysis of variance (ANOVA) was applied to the data through Sisvar version 5.6. Insect pests that were sampled during the study were Sitophilus zeamais, Cathartus quadricollis, Carpophilus dimidiatus and Tribolium castaneum. Carpophilus dimidiatus were sampled from treatments during the major season whereas Tribolium castaneum was sampled during the minor season. Sitophilus zeamais and Cathartus quadricollis were sampled in both seasons.  In the major season, late harvest shelled maize (LHS) recorded 689% more S. zeamais numbers as compared to early harvest husked maize (EHH). Mid-harvest husked maize (MHH) had 307% less number of S. zeamais compared to LHS in the minor season. Late-harvest shelled maize (LHS) had the highest percentage insect damaged kernels (86.94%) in the major season