bluuebunny/crossref_metadata_2025_split huggingface dataset:
Dowling–Degos Disease
Authors: Al Hawsawi Khalid , Aser Rehab , Khoj Zaker , Barnawi Ghassan , Alhawsawi Waseem 
Published: April 2021

Abstract
Dowling–Degos disease (DDD) is an uncommon autosomal dominant genodermatosis characterized by reticular hyperpigmentation in the intertriginous areas. Herein, we report a case of follicular DDD which is a very rare variant of DDD. A 45-year-old healthy male presented with 1-year-history of asymptomatic slowly progressive skin lesions in the axillae. Skin examination revealed multiple nonscaly pigmented follicular papules and macules in both axillae but more severe in the right side. No other skin lesions elsewhere in the body. Hair, nails, and mucus membrane were all normal. Skin biopsy showed follicular plugging with the presence of pigmented filiform rete ridges originating from the follicular epithelium. The patient was diagnosed as follicular DDD. The patient was reassured. Electrocautery treatment was used, which leads to a remarkable improvement of the lesions.
Acral Subcorneal Hematoma
Authors: Nassar Ahmed H. , Abu-Aliat Abdullah S. , Hawwam Soha A. 
Published: April 2021

Abstract

Background:
Acral subcorneal hematoma (ASH) is a dark-colored skin lesion of the palms and/or soles due to bleeding. ASH may be difficult to be clinically differentiated from acral melanocytic lesions, resulting in unnecessary biopsies. Few researches reported the importance of dermoscopy in differentiating ASH from acral melanocytic lesions.

Purpose:
This study aims at reporting the dermoscopic features in a series of ASH to facilitate precise diagnosis and to avoid performing unnecessary surgical techniques.

Methods:
Eighteen patients with ASH were studied. Dermoscopic images were obtained using a handheld dermoscope and a dermoscope-adopted phone camera. Paring test was performed on all lesions.

Results:
The preliminary diagnoses of the lesions were ASH in 55.6%, acral melanocytic nevi in 33.3%, and acral lentiginous melanoma in the remaining 11.1%. Dermoscopically, the lesion colors were red-black in 44.4%, black in 27.8%, and brown in the remaining 27.8%. The pigmentation patterns were homogeneous (structureless) in 55.6%, parallel ridge in 27.8%, and negative pseudonetwork in the remaining 16.6%. Over 44% of the lesions had red and/or brown globular satellites. Peripheral red lines with/without radial extensions were noticed around ASH in 55.6%. Paring led to complete removal of pigmentation in all ASH (100%), with the appearance of post-paring blood-tinged serum in 55.6%. No skin biopsies were performed.

Conclusion:
Although there is clinical similarity between ASH and acral melanocytic lesions, dermoscopy and paring test can facilitate a precise diagnosis and markedly decrease the need for unnecessary invasive procedures.
Clinico-Epidemiological Factors Related to Lichen Planus and Its Clinical Variants at a Tertiary Care Hospital
Authors: Gupta Ankit , Nayak Chitra S. 
Published: April 2021

Abstract

Background:
Lichen planus (LP) is an immune_mediated, chronic inflammatory disease involving skin, oral and genital mucosa, nails, and hair with several morphologic variants. The exact etiology remains unclear, but several factors have been implicated.

Purpose:
To study the clinico-epidemiological profile of patients of LP and its clinical variants and to find out whether LP is relatively uncommon in children.

Methods:
This prospective, cross-sectional, descriptive, time-bound, clinico-epidemiological study was conducted in the outpatient department of dermatology at a tertiary care hospital during the period of June 2017 to October 2018. A total of 170 patients were included in the study. Microsoft Excel and SPSS 23 software packages were used for data entry and statistical analysis. The results were averaged for each parameter for continuous data and numbers and percentage for categorical data. Statistical tests were applied wherever necessary.

Results:
The overall prevalence of LP was 0.4% (n = 170) out of 42,127 patients who attended the OPD during the study period. The gender-wise prevalence of LP was 41% among females and 59% among males, and the difference was not statistically significant (P = 0.3). The male-to-female ratio was 1.5:1. The highest prevalence among the variants of LP was of classical form (29%) and lowest was of inverse LP (0.6%). Overall, the mean age of the patients was 36 years, with a standard deviation of 17. There was one instance of LP occurring in both father and son.

Conclusion:
The most common age group of LP was 18 -40 years. Most patients came to seek health care within 1 year of beginning of disease. More than one variant of LP can coexist in the same individual. Childhood LP is not uncommon in the Indian subcontinent.
Effect of Oral Propranolol on Periocular Infantile Capillary Hemangioma
Authors: Bejjanki Kavya M. , Akhtar Kahkashan , Gupta Arushi P. , Kaliki Swathi 
Published: April 2021

PURPOSE:
To evaluate the efficacy of oral propranolol in the treatment of periocular infantile capillary hemangioma (CHI) based on the involvement of embryological facial placodes and their extent of anatomical involvement.

METHODS:
Retrospective study of 27 patients.

RESULTS:
The mean age at the presentation of periocular CHI was 4 months (median, 3 months; range, <1–14 months). There were 11 (41%) males and 16 (59%) females. Based on embryological facial placodes, the involvement was focal in 16 (59%) cases and segmental in 11 (41%) cases. Based on the anatomical distribution, the lesions were preseptal in 4 (15%), postseptal in 13 (48%), and combined in 10 (37%) cases. The duration of use of oral propranolol was 10 months (median, 10 months; range, 4–16 months). Overall, the mean % resolution of periocular CHI was 78% (median, 90%; range, 20%–100%). The mean percentage resolution of focal lesions was 69% (median, 83%; range, 20%–100%), and segmental lesions were 92% (median, 95%; range, 70%–100%). The mean percentage resolution of preseptal component of lesions was 94% (median, 95%; range, 80%–100%) and postseptal component was 74% (median, 85%; range, 20%–100%) over a mean follow-up period of 16 months (median, 15 months; range, 4–37 months). Four (15%) patients exhibited flare-up of lesion after tapering oral propranolol.

CONCLUSION:
Oral propranolol is effective in the treatment of periocular CHI. Segmental and preseptal lesions respond better to the treatment compared to focal and postseptal lesions.
Pheromone deposition/updating strategy in a network: using ant colony optimization (ACO) approach
Authors: Ogban Felix U. , Nentui Roy 
Published: April 2021

The study and understanding of the social behavior of insects has contributed to the definition of some algorithms that are capable of solving several types of optimization problems. The most important and challenging problems that the ants encounters when routing through a network arc, is their ability to searching for the path with a shorter length as well as to minimize the total cost incurred in the process of routing through the network. In this paper, we introduced some features to the existing Ant Colony Optimization (ACO) algorithm to help tackle this problem. First, we defined two kinds of pheromone and then we also defined three kinds of heuristic information to guide the searching direction of ants for this bi-criteria problem. Each of the ants uses the heuristic types and the pheromone types in each iteration based on the probability, controlled by two parameters. These two parameters are adaptively adjusted in the process of the algorithm. Second, we used the information of the partial solutions to modify the bias of ants so that inferior choices will be ignored. Finally, we tested the performance of the experimental results of the algorithm in an application under different Deadline constraints and the performance of the algorithm prove to be more promising, for it outperformed the performance of most of the algorithm we downloaded on line.Keywords: Ant Colony Optimization algorithm, Pheromone Deposition, Pheromone Updating strategy, Cost Minimization, Network Routing, Optimization problem.
Carbothermal Upgrading of the Awaso Bauxite Ore using Sawdust and Coconut Shells as Reductant
Authors: Fosu A. Y. , Fosu N. , Owusu K. B. , Dankwah J. R. 
Published: April 2021

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, Char
Improving Land Tenure Security through Customary Boundary Demarcation- A Case Study
Authors: Asenso-Gyambibi D. , Affam M. , Amoafo E. Y. , Acquah S. B. 
Published: April 2021

In sub-Saharan Africa, one of the barriers to development and wealth creation in the peri urban and rural areas is land tenure insecurity. This is mainly due to a number of factors including the absence of clear unambiguous boundaries between allodial owners and the absence of credible documentation of land rights. This research sought to establish and document over 190 km of the boundary of Juaben paramouncy in a manner that ensured peace, harmony and tenure security. Disputes were resolved through less costly Alternative Dispute Resolution (ADR) mechanisms and Customary Land Secretariat (CLS) that catalogued and maintained up to date register on the land. This resulted in conflicts that have raged on for decades, sometimes leading to injury, property destruction and loss of lives come to an end. The benefits of this improved land tenure security are enhanced agricultural productivity, wealth creation for rural dwellers, peace and stability. Boundary demarcations and documentations established were important steps in the process of reformation and improving land tenure security in the rural communities. Information retrieval was simplified and transaction cost made cheaper. Keywords: Land Tenure Security, Customary Boundary Demarcation (CBD), Alternative Dispute Resolution (ADR)
Understanding the Mechanism of Arsenic Mobilisation and Behaviour in Tailings Dams
Authors: Koomson B. , Asiam E. K. , Skinner W. , Addai-Mensah J. 
Published: April 2021

This study was carried out on leaching of tailings at 30 ᵒC and 40 ᵒC. The mineralogical and chemical composition of the tailings material were determined by Quantitative X-Ray Diffractometry (QXRD) and Scanning Electron Microscopy combined with Energy Dispersive Spectroscopy (SEM-EDAX). The study revealed that the tailings contain sulphides (arsenopyrite and pyrite) which can leach to produce arsenic (As) and other ions in solution. The acid released during leaching depends on the temperature of leaching. More acid was produced at higher temperature (40 ᵒC) than lower temperature (30 ᵒC). It was established that arsenic precipitation from solution was higher at higher temperature (40 ᵒC) than lower temperature (30 ᵒC). Mimicking the study in a typical tailings environment, it could be proposed that As mobilisation will be enhanced at lower temperature (30 ᵒC) than at higher temperature (40 ᵒC). Keywords: Tailings, Leaching, Arsenopyrite, Heavy metals and Temperature
Groundwater Vulnerability Assessment of the Tarkwa Mining Area Using SINTACS Approach and GIS
Authors: Ewusi A. , Ahenkorah I. , Kuma J. S. Y. 
Published: April 2021

Groundwater vulnerability assessment to delineate areas that are susceptible to contamination from mining and anthropogenic activities has become an important element for resource management and landuse planning. In view of the extensive mining in the Tarkwa area, quality of groundwater has become an important issue. This study estimates aquifer vulnerability by applying the SINTACS model which uses seven environmental parameters to evaluate aquifer vulnerability and geographical information system (GIS) in the Tarkwa mining area. Sensitivity analysis has also been carried out to evaluate the relative importance of the model parameters for aquifer vulnerability. The SINTACS model results show that the intrusive rocks within the Tarkwaian and the Birimian rocks are dominated by very high vulnerability classes while the Banket Series is characterised by high vulnerability class. The Huni Sandstones have moderately high vulnerability. In addition, the Kawere Group and the Tarkwa Phyllites displayed medium vulnerability. Analysis from the variogram model shows that all parameters used in the SINTACS model have a strong spatial structure. From statistical analysis, depth to water parameter inflicted the highest impact on the vulnerability of the aquifer followed by effective infiltration, vadose zone media, soil media, aquifer media, topography and hydraulic conductivity in the order of decreasing impact. Sensitivity analysis indicated that the aquifer media, hydraulic characteristics and topography cause large variation in vulnerability index. Depth to water and effective infiltration were found to be more effective in assessing aquifer vulnerability. Keywords: Groundwater, Vulnerability, Tarkwa, SINTACS, GIS
Recycling Waste Polyurethane as a Carbon Resource in Ironmaking
Authors: Dankwah J. R. , Buah W. K. 
Published: April 2021

Globally, major avenues available for dealing with waste Poly-Urethane (PU) are disposal at landfill sites and incineration. However, PU contains high levels of carbon and hydrogen that can be recovered for use as reductant in metal extraction processes. In this work the use of post-consumer PU as reductant for the production of metallic iron from iron oxide was investigated in a horizontal tube furnace through the composite pellet approach. Composite pellets were formed from mixtures of iron oxide and post-consumer PU. The iron oxide-PU composites were heated from room temperature to 1200 °C and then between 1200-1600 °C in a continuous stream of pure argon and the off gas was analysed continuously using an infrared (IR) gas analyser. Elemental analyses of samples of the reduced metal were performed chemically for its oxygen content using a LECO oxygen/nitrogen analyser. The extent of reduction was then determined at two temperatures 1200 °C and 1550 °C. Gas emission studies revealed the emission of large volumes of the reductant gas CO along with CO2. It is further demonstrated that post-consumer PU is effective at reducing iron oxide to produce metallic iron with complete reduction achieved in less than 4 min at 1550 °C. Keywords: Polyurethane, Composite Pellets, Infrared gas Analyser, LECO Carbon/Sulphur Analyser
Appraisal of ANN and ANFIS for Predicting Vertical Total Electron Content (VTEC) in the Ionosphere for GPS Observations
Authors: Yakubu I. , Ziggah Y. Y. , Asafo-Agyei D. 
Published: April 2021

Positional accuracy in the usage of GPS receiver is one of the major challenges in GPS observations. The propagation of the GPS signals are interfered by free electrons which are the massive particles in the ionosphere region and results in delays in the transmission of signals to the Earth. Therefore, the total electron content is a key parameter in mitigating ionospheric effects on GPS receivers. Many researchers have therefore proposed various models and methods for predicting the total electron content along the signal path. This paper focuses on the use of two different models for predicting the Vertical Total Electron Content (VTEC). Artificial Neural Network (ANN) and Adaptive Neuro Fuzzy Inference System (ANFIS) algorithms have been developed for the prediction of VTEC in the ionosphere. The developed ANN and ANFIS model gave Root Mean Square Error (RMSE) of 1.953 and 1.190 respectively. From the results it can be stated that the ANFIS is more suitable tool for the prediction of VTEC. Keywords: Artificial Neural Network, Adaptive Neuro Fuzzy Inference System, Vertical Total Electron
Mining and Metal Pollution: Assessment of Water Quality in the Tarkwa Mining Area
Authors: Ewusi A. , Apeani B. Y. , Ahenkorah I. , Nartey R. S. 
Published: April 2021

The quality of water in mining communities is uncertain since metals associated with acid mine drainage are known to saturate these waters. Previous studies in Tarkwa, an area noted for gold and manganese extraction, have reported large concentrations of aluminium, arsenic, cadmium, copper, lead, manganese and mercury in water samples. This research aimed at investigating the chemistry of groundwater with special focus on the contamination status of trace elements. It also compared levels of metal concentration with those that were determined in previous research works, to identify changes that might have occurred. Thirty-eight water samples from boreholes, hand-dug wells and streams, within the Tarkwa area were obtained and analysed. Results show that 90 % of water in the area is acidic and Eh was determined to be positive, depicting oxidizing conditions. Mean groundwater temperature was 28.9 ºC. Thirty-two samples had either temperature or pH values falling outside the range recommended by the World Health Organisation (WHO). Thirty samples had at least one metal concentration exceeding the WHO guideline values. Among the list of elements that exceeded the guideline, arsenic, manganese, nitrate, nitrite and iron were the most predominant. The dominant ions in the samples were sodium and bicarbonate. High concentrations of Fe and SO42- in some parts of the study area point to the influence of acid mine drainage (AMD). Comparisons of results of metal concentrations with findings from previous research in the area showed a reduction in concentration. Hydrochemical modelling with PhreeqC attributed this reduction to sorption processes. Comparison of levels of metal concentration in the different water supply facilities (borehole, hand-dug well and stream) showed no significant variations. Keywords: Water Quality, Drinking Water, Hydrochemical Modelling, Heavy Metals
Waste Dump Closure and Cost Estimates at AngloGold Ashanti Iduapriem
Authors: Arhinful K. O. A. , Agyei G. 
Published: April 2021

AngloGold Ashanti Iduapriem Mine is a surface gold mine which produces waste rock in its operations. The waste rock forms waste dumps which grow over the years, and will ultimately need to be closed down when they are filled to the maximum capacity. The mine has closure plans for the waste dumps and the closure activity will incur cost. This research was carried out to study the waste dump reclamation and closure plan for the Ajopa waste dump, and estimate the associated cost. The aim of the closure is to establish a permanent stable landscape that is environmentally compatible with surrounding undisturbed land. The waste dump will be closed with a progressive rehabilitation technique. The key activities involved in the reclamation plan, which are earthworks, capping and revegetation were identified and studied into detail. The reclamation plan and cost estimates were prepared on the basis that AngloGold Ashanti Iduapriem Mine would contract with a third-party contractor to fully execute the required closure and reclamation activities. The cost was then estimated using price quotes from vendors or contractors located around the mining area. Results showed that waste dump closure and reclamation programme for Iduapriem Mine are consistent with Ghana Mining and Environmental guidelines. The total closure and reclamation cost was estimated to be US$ 581 488.18. Since any delay in the closure and reclamation could incur additional cost, it was advised that the mine should execute the closure and reclamation plan without delay. Keywords: Waste Dump, Reclamation, Revegetation, Estimates
Evaluation of Groundwater Suitability for Irrigation in the Lambussie-Karni District of Ghana
Authors: Asante-Annor Asare , Bewil P. N. , Boateng D. 
Published: April 2021

The populace of the Lambussie-Karni District are mainly farmers who have resorted to the use of groundwater for irrigation during the dry season because of long drought and inadequate surface water bodies. The temporal variation of the groundwater quality for irrigation in the District was assessed using sixteen boreholes. Richard Plot indicates that groundwater in the study area is within the low salinity to low sodium hazard and medium salinity to low sodium hazard class. Wilcox Plot shows groundwater to be within excellent to good class in the catchment. Irrigation water quality index (IWQI) map was also developed to determine precisely the degree and areal extent of groundwater suitability for irrigation. ArcGIS 10.1 was used to generate thematic maps for sodium adsorption ratio (SAR), residual sodium carbonate (RSC), permeability index (PI), sodium percentage (Na %), HCO3-, pH and electrical conductivity. The results were compared to Food and Agricultural Organisations (FAO) standard guidelines. An IQWI map for the Lambussie- Karni District shows that groundwater is generally suitable for irrigation, about 24.57 % of the district will require crops which can tolerate high amount of salts. A percentage (39.82 %) of the catchment has groundwater, which is highly suitable for crops which are least resistant to salt. Keywords: Groundwater Suitability; Irrigation Water Quality; SAR; IWQI Map; Lambussie-Karni District
The Effect of Clay Pozzolana-Cement-Composite on the Strength Development of a Hydraulic Backfill
Authors: Eshun S. N. , Gidigasu Solomon Senyo Robert , Gawu S. K. Y. 
Published: April 2021

The study sought to investigate the potential application of clay pozzolana as a supplement for cement in hydraulic backfill, using classified tailings from AngloGold Ashanti, Obuasi Mine. The percentage of the Portland cement that could be substituted with the clay pozzolana to produce backfill with best strength was determined. 10%, 25%, 30%, 35% and 40% of the ordinary Portland cement were replaced with clay pozzolana and then mixed with tailings and water. The slurry produced was cast into cylindrical specimen of 50mm diameter by 120mm high and tested for compressive strength after curing for 7, 14, 21, 28 and 56 days. The results indicate that, clay pozzolana-cement composite has potential for application in hydraulic back fill production without increased risk to safety and dilution. It was noted that hydraulic backfill with 10%, 25%, 30% and 35% of the ordinary portland cement replaced with clay pozzolana had strengths greater than those obtained for ordinary portland cement alone. Ten percent (10%) pozzolana content gave the maximum strength followed by 25% pozzolana. It is recommended that for safety and economic considerations, the cement content should be replaced by 25% pozzolana in the production of backfills. Keywords: Hydraulic Backfill, Portland Cement, Clay Pozzolana, Unconfined Compressive Strength