bluuebunny/crossref_metadata_2025_split huggingface dataset:
Safety and Efficacy of Epithelial Island Crosslinking in Keratoconus with Thinnest Pachymetry less than 400µ
Authors: Omar Hisham A. , El-Agha Mohamed-Sameh H. , Hassaballah Mohamed A. , Khalil Noha M. 
Published: April 2021

PURPOSE:
To evaluate the efficacy and safety of epithelial-island crosslinking (EI-CXL) in keratoconus with corneas thinner than 400 µm.

METHODS:
Twenty-six patients (30 eyes) underwent EI-CXL (preserving the epithelium over the thinnest area), using standard protocol (3 mW/cm2 for 30 min). Uncorrected and best spectacle-corrected distance visual acuity (UCDVA, BCDVA), manifest refractive spherical equivalent (SEQ), mean simulated keratometry (Kmean), maximum keratometry (Kmax), and thinnest corneal thickness (TCT) were determined preoperatively and at 1, 3, 6, and 12 months following CXL. Endothelial cell count (ECC) was determined preoperatively and at 6 months. Anterior segment optical coherence tomography (AS-OCT) was done at 1 month to determine the depth of the corneal stromal demarcation line (DL).

RESULTS:
After 1 year, mean UCDVA improved from 1.29 preoperatively to 1.17 (P = 0.001) and BCDVA from 0.62 to 0.57 (P = 0.011). Mean manifest SEQ decreased from -7.63 to-7.32D (P = 0.001). Mean Kmean decreased from 54.92 to 54.81D (P = 0.045), and Kmax from 67.60 to 67.42D (P = 0.072), and mean TCT changed minimally from 377.17 to 375.30 µ (P = 0.11). The mean ECC decreased from 2329 to 2268 cells/mm2 (2.6% decrease, P < 0.001). AS-OCT showed a DL in 29 out of 30 eyes at an average depth of 215.9 µ under the spared epithelium, and 299.9 µ in the de-epithelialized cornea.

CONCLUSION:
EI-CXL halted keratoconus progression over a 1-year period. This was associated with statistically significant endothelial loss, but less than seen with conventional epi-off CXL in thinner corneas.
Improving utilization of conceptual and theoretical framework in nursing research
Authors: Akpabio II 
Published: April 2021

The Nursing and Midwifery Councils of many nations including Nigeria and nursing departments of various Universities and institutions have made it mandatory that conceptual and theoretical framework are used to guide Nursing research presented as part of the requirements for the award of certificates and degrees. However, it is often observed that many researchers are not skilled in the use of conceptual and theoretical framework and many do not also utilize conceptual or theoretical framework to guide studies conducted after graduation from their various educational institutions. Others do so for some parts of the research and do not also explain how the framework can be used to guide implementation of the study findings. Additionally, many publishers of research reports do not also demand for inclusion of framework in papers accepted for publication. This paper is aimed at highlighting the importance of using a conceptual framework to guide a study, the criteria that should guide the appraisal and selection of a framework; challenges that can hinder utilization of framework to guide research work and measures of improving utilization of conceptual framework in nursing research.KEYWORDS: Conceptual, Framework, Nursing, Research, Theoretical.
Internationalisation of Artisanal and Small Scale Mining in Ghana: Opportunities and Challenges
Authors: Agyei G. 
Published: April 2021

The last few years have witnessed internationalisation of small scale mining in Ghana. The entry of migrant artisanal miners has brought losers and winners in the subsector, creating myriad of socio-political problems. However, official attempts to curb it have exacerbated the systemic problem of mineral governance. This paper analyses the emerging challenges and opportunities posed by the entrance of migrant miners into the country with insights into assumptions on resources and conflicts. It takes a closer look at the causes, effects and dynamics of confrontation and collaboration between migrant artisanal and small scale miners and their counterparts in the host nation. It argues that the current governance system of small scale mining based on national control over exploitation is anachronic and not well adapted to competitive, sustainable and fair management of mineral resources. In addition, it proposes a sustainable partnership to harness complimentary skills in order to avoid deepening the resources conflicts which have plagued the mining districts. Keywords: Internationalisation, Artisanal, Small Scale Mining, Sustainability
Selecting Suitable Sites for Mine Waste Dumps Using GIS Techniques at Goldfields, Damang Mine
Authors: Suleman H. A. , Baffoe P. E. 
Published: April 2021

AbstractThe selection of optimal sites for mine waste dumps is a significant problem associated with surface mines operations. A number of factors such as financial, environmental and safety requirements must be simultaneously considered to avoid potential losses. This research used the ModelBuilder tool and several GIS spatial analyst tools to select suitable sites for mine waste dump. The weighted overlay technique was adopted by first determining the necessary criteria and constraints and subsequently developing attributes for each criterion. The criteria used were grouped into a binary category of suitable and unsuitable. A total area of 17.01 km2 was determined as suitable, while 66.10 km2 was classified as unsuitable after overlaying and weighting all the criteria. Out of the suitable areas, an area of 13.62 km2 consisting of 21 sites were determined as optimal. Applying further constraints, 2 out of the 21 optimal sites were determined as the best sites. A step-wise model has been developed using ModelBuilder for selecting an economic but effective site for dumping mine waste using suitable constraints and criteria. This has facilitated the production of suitability maps generated from the various datasets being used for mine waste dump site selection. The final output map that best fits the criteria and constraints can be used by decision makers to set out the areas suitable for mine waste dump sites on the mine concession. The model could be applied as the standard model for selecting sites for mine waste dumps, since there is no standard model available at the moment. Keywords: ModelBuilder, GIS, Constraints, Waste Dumps, Weighted Overlay
An Economic Evaluation of the Loye Quarry of Atiwa Quarries Limited
Authors: Mireku-Gyimah D. , Owusu Ansah N. K. 
Published: April 2021

Atiwa Quarries Limited (AQL) is one of the large operating granite quarries in the Central Region of Ghana. AQL’s current production of 24 000 m3 of aggregates per month cannot meet current demand let alone support a new contract to supply 25 000 m3 of aggregates per month for a major road infrastructure project. Fortunately, AQL has another granite concession at Loye, about 3 km from the first concession, with estimated granite reserves of 6 286 208 m3, which can be developed as a new quarry to meet the demand of the new contract. This will require capital to build infrastructure, purchase equipment, recruit labour and provide working capital. The objective of this paper is to evaluate the economic viability of the new quarry, considering it as a stand-alone project. The yearly revenue was estimated based on projected production of 25 000 m3/month and average price of US$ 15.63/m3. Capital and operating costs were estimated using detailed cost estimation method based on quotations from equipment suppliers and operational unit costs of AQL. It turns out that AQL can generate yearly gross revenue of US 4.69 million but requires total capital of US$ 3.67 million; the yearly operating cost is US$ 1.72 million. Cash flow and sensitivity analyses using Net Present Value (NPV) and Internal Rate of Return (IRR) as criteria, and risk analysis using Monte Carlo simulation method were carried out. The economic analysis indicates that based on AQL’s preferred capital structure of 80% equity and 20% loan, the NPV is $ 5.17 million and the IRR is 53.01%, showing the new quarry is profitable; the sensitivity analysis indicates that the project can withstand up to 40% drop in revenue, or over 60% increase in capital or operating cost. The risk profile indicates a probability of success of 98.2%. The study therefore recommends that AQL invests in the new quarry as it is economically viable. Keywords: Granite Quarry, Net Present Value, Internal Rate of Return, Sensitivity Analysis, Risk Analysis
Assessment of the Challenges in Policy Implementation in the Small Scale Gold Mining Sector in Ghana – A Case Study
Authors: Eshun P. Arroja , Okyere E. 
Published: April 2021

In recent times, stakeholders in the mining sector have expressed concerns about the environmental degradation and the social impacts of uncontrolled Small Scale Mining (SSM) activities in Ghana despite the existence of legislative instruments that define the procedures required for the acquisition of licences and operations of SSM activities in the country. This paper assesses the challenges in policy implementation in the small scale gold mining sector of Ghana by reviewing policies on regularisation and environmental management. It further identifies challenges faced by small scale mining operators in adhering to laid down policies for the smooth operation of the sector and furthermore assesses the views of some principal stakeholders on the benefits and challenges of small scale mining using the Dunkwa mining district as a test case. The methods employed include: field visits to some small scale mining sites within the Dunkwa mining district; interviews and questionnaire administration; and statistical and content analysis of data. The study reveals the following factors, among others, to have contributed largely to the difficulty in regularisation, environmental and social challenges that have plagued the SSM sector: low level of education of majority of miners; bureaucracies and centralisation of licence acquisition processes; lack of sources of finance for SSM projects; lack of geological information on mineable areas; and lack of adequate knowledge of the laws and regulations on mining and environment. In addressing the challenges the following recommendations are made: decentralisation of the regularisation processes to simplify licence acquisition; adequate geological investigations should be undertaken on SSM blocked-out areas to reduce the try and error mining approach adopted by miners; and continuous education and training of miners on good mining and environmental practices. Keywords: Small Scale Mining, Mineral Policies, Environmental Impact, Regularisation, Challenges
Application of Microwave Energy for Production of Iron Nuggets from the Pudo Iron Ore using ‘Pito’ Waste and its Blend with HDPE as Reductant
Authors: Aakyiir M. N. , Dankwah J. R. 
Published: April 2021

The local steel industry is currently facing stiff competition from South East Asia and elsewhere for high grade scrap iron, culminating in a ban by central Government on the export of ferrous scrap. In this work we investigate the potential for producing high grade iron nuggets from the Pudo iron ore in the Upper West Region of Ghana, using carbonaceous materials generated from locally available ‘pito’ waste and its blend with high density polyethylene (HDPE) as reductant. Composite pellets of the ore containing various blends of uncharred ‘pito’ and charred ‘pito’ waste with HDPE were irradiated in a domestic microwave oven and the extent of reduction was determined after 40 min of irradiation. It was observed that highly carburised premium grade iron nuggets can be produced from the Pudo iron ore using ‘pito’ waste (both charred and uncharred) and its blends with HDPE as reductant. The measured extent of reduction ranged from about 47 % to about 96 %, suggesting that the Pudo iron ore is a potential source of iron from which premium grade metallic iron can be produced commercially to feed the local steel industry. From the point of view of chemical reactivity, it appears the effect of hydrogen is more pronounced than the amount of fixed carbon in the ‘pito’ waste and this effect was felt in all the HDPE-‘pito’ waste blends utilised for the investigation. Accordingly dry ‘pito’ waste may be used directly with HDPE as reductant without the need to char the biomass. Keywords: Reduction, Pudo Iron Ore, Waste Biomass, Pito Waste, Extent of Reduction
Optimising Shovel-Truck Fuel Consumption using Stochastic Simulation
Authors: Dumakor N. K. , Temeng V. A. , Bansah K. J. 
Published: April 2021

Stochastic simulation was conducted to analyse the fuel consumption of a shovel-truck system. An example shovel-truck system, comprising a single shovel and four trucks was considered. At 95% confidence interval, the monthly simulated fuel consumption by the shovel-truck system was found to be about 198 127 litres against the actual fuel consumption of 203 772 litres, registering a variance of -2.70%. About 22 000 litres of fuel was consumed per month due to truck waiting. Optimising the fuel consumption and truck waiting time can result in significant fuel savings. The paper demonstrates that stochastic simulation is an effective tool for optimising the utilisation of fossil-based fuels in mining and related industries. Keywords: Stochastic, Simulation Modelling, Mining, Optimisation, Shovel-Truck Material Handling
Performance Evaluation for Mean Sea Level Prediction using Multivariate Adaptive Regression Spline and Artificial Neural Network
Authors: Boye Cynthia Borkai , Amoah Valentine Ikechukwu 
Published: April 2021

Mean sea level (MSL) has been used as a vertical datum for geodetic levelling and mapping in most countries all over the world. This is because the MSL approximates the geoid and serves as a realist reference surface that could be determined mostly through tide measurements over a period of time. However, sea levels have been rising over the years due to global warming and its associated climate change which continuous to melt ice sheets around the Polar Regions. This phenomenon is likely to affect the reliability of MSL, thus it is important to determine the local MSL at regular time periods. This study assessed the performance of Artificial Neural Network (ANN) and Multivariate Adaptive Regression Spline (MARS) models in predicting the MSL. Tide gauge records from the Takoradi Harbour of Ghana were used in the study. Monthly maximum, minimum and mean tidal values were derived from the secondary data and used for both model formulation and model testing. A comparative analysis of both models showed that the ANN model performed better than the MARS model. A Root Mean Square Error (RMSE) of 0.0359 m was obtained for the ANN model, whereas 0.0555 m was obtained for the MARS model. Mean Absolute Percentage Error (MAPE) of 3.1414% was obtained for the ANN model and whereas the MARS model yielded 5.6349%. A Mean Absolute Error (MAE) for the ANN model was 0.0284 m as against 0.0446 m for the MARS model. Correlation coefficient values of 0.9720 and 0.8874 were obtained for the ANN model and the MARS model respectively. An optimum ANN structure was found to be ANN 2-11-1. Based on the outcome of this study, it is recommended that ANN model should be adopted for forecasting local mean sea level for the study area. Keywords: Mean Sea Level, Artificial Neural Network, Multivariate Adaptive Regression Spline
PRODUCCIÓN DE BIOGÁS A PARTIR DE LAS AGUAS RESIDUALES DE CAFÉ INSTANTÁNEO
Authors: Garcia Cabrera Juan Miguel , Córdova Mosquera Rosa Alexandra 
Published: April 2021

Este trabajo de investigación tuvo como propósito evidenciar la producción de biogás generado por medio de una digestión anaerobia de las aguas residuales producidas por la industria procesadora de café instantáneo, ya que debido a la elaboración de este producto se obtienen altos volúmenes de aguas residuales, encontrando en su composición compuestos recalcitrantes. Una de las posibles alternativas en el tratamiento de efluentes recalcitrantes es la aplicación de procesos oxidativos avanzados (POA), influyendo en la disminución de la demanda química de oxígeno (DQO) y del carbono orgánico total; siendo valorado el sustrato del agua residual sintética de café instantáneo mediante el potencial bioquímico del metano (BMP) como principal componente en la generación de biogás. Se caracterizó el inoculo en función de los sólidos volátiles suspendidos, El potencial Bioquímico de metano se realizó a temperatura mesofílica y Termofílica (35 ºC y 55 ºC) con cargas orgánicas de 0,1; 0,2; 0,35 y 0,5 gDQO/gSSV con la presencia de taninos y en cargas orgánicas de 0,2 y 0,35 gDQO/gSSV con remoción de taninos, ambas durante un periodo de 25 días; el agua residual de café instantáneo utilizada presentó concentraciones de DQO que oscilaron entre ≥4000 mg/L y ≥4478 mg/L, aplicando un inóculo procedente de un reactor anaerobio de la industria de pescado EUROFISH. Los procesos fueron monitoreados a través de parámetros como DQO, DBO, SSV, pH, temperatura y rendimiento de metano, mostrando comportamientos diferentes en la degradación de la materia orgánica acorde a las cargas aplicadas.
VALORACIÓN DASOMÉTRICA DE UNA PLANTACIÓN DE Tectona grandis L. f. EN EL CANTÓN BALZAR, PROVINCIA DEL GUAYAS
Authors: Cabrera Verdesoto Cesar Alberto , Osejos Carvajal José Miguel , Ramos Rodriguez Marco Pedro , Jiménez Gonzalez Alfredo , Buste Ponce Yovanny Ramón 
Published: April 2021

En la presente investigación se realizó la valoración dasométrica de una plantación de Tectona grandis L.f. ubicada en la provincia del Guayas, cantón de Balzar, hacienda La Sabana Forestal 1. De acuerdo a los resultados obtenidos se determinó que el diámetro desarrollado es 9.55 cm, en el periodo 2015.m. La altura lograda tiene un promedio de 8,49 m de altura, el incremento medio anual de volumen comercial (m3) por hectárea de la plantación forestal de teca es de 7,68 m3/ha/año, en el periodo 2015. El incremento medio anual del diámetro el resultado fue de 2,73 cm/año, el incremento medio anual altura se obtuvo 2,43 m/año. El incremento medio anual en volumen los resultados obtenidos utilizando el coeficiente general de factor de forma para madera en trozas de 0,5 fue de 6,40 m3/ha/año, y utilizando el coeficiente para Tectona grandis, madera en pie factor de forma 0,6 se obtuvo como resultado 7.68 m3/ha/año. El ICA se lo realizo entre el periodo de los años 2014 y 2015, de lo que se obtuvo los siguientes resultados: el incremento corriente anual del diámetro fue de 2,43 cm., el incremento corriente anual de la altura total fue de 1.73 m., el incremento corriente anual correspondiente al volumen con coeficientes general de factor de forma para madera en trozas de 0,5 se obtuvo como resultado 12,30 m3/ha/año, utilizando el coeficiente para Tectona grandis, madera en pie 0,6 se obtuvo como resultado 14,76 m3/ha/año.
BRECHA DIGITAL Y SU IMPACTO EN LA EDUCACIÓN A DISTANCIA
Authors: Pita Salazar Raquel Azucena , Cevallos Flores Shayla Ayllin , Maldonado Zuñiga Kirenia 
Published: April 2021

Esta investigación se llevó a cabo para presentar la existencia de la brecha digital y le educación en línea, uno de los temas más recientes en la actualidad, la importancia de este trabajo fue conocer sobre su impacto en la sociedad actual y de esta manera obtener conocimientos claros y concretos acerca de la educación digital existente en nuestro país, también constituye un análisis descriptivo de los principales beneficios e inconvenientes que generan las tecnologías de información y comunicación, de igual modo se aborda todo lo relacionado a la brecha digital, es decir el espacio que existe entre aquellos que poseen mayores accesos a las tecnologías y los que no lo tienen, así como también, los diferentes causas y consecuencias de la misma. El objetivo de esta investigación, es diagnosticar la situación actual del país, en materia de tecnologías, información y cultura digital, para determinar las necesidades que tiene, compuesta por distintos estratos sociales y culturales, mediante un estudio, basado en análisis de investigación aplicadas a la educación en línea, que conllevan a una profunda reflexión acerca de la transición al conocimiento digital, y las falencias y obstáculos con los que se encuentran a la hora de hacer uso del mismo. Como conclusiones principales, se destaca la importancia de promover el acceso a las Tecnologías de la Información y Comunicación, no solo, a través de la dotación de equipamiento y conectividad sino por medio de la capacitaciones tecnológicas, convencidos que el aprendizaje tecnológico es esencial para el desarrollo del país.
AVALIAÇÃO DO POTENCIAL DO USO DE PINHÃO MANSO PARA A GERAÇÃO DE BIOCOMBUSTÍVEIS
Authors: Zambrano Gavilanes Freddy , Souza Andrade Diva , Rodrigues Silva Helder , García Cruzatti Luz , Cedeño Palacios Carlos 
Published: April 2021

O pinhão manso (Jatropha curcas L.) tem-se apresentado como uma oleaginosa importante, com aplicações medicinais e industriais. Assim o trabalho aqui apresentado teve como principal objetivo avaliar o potencial do uso de pinhão manso para a geração de biocombustíveis. A Jatropha tem relevância especialmente para o desenvolvimento da bioenergia, pela percentagem de óleo em suas sementes que pode variar de 40-60%, servindo para a fabricação de biodiesel. As cascas de seus frutos podem ser consideradas para a produção de etanol por seu alto conteúdo de celulose. A torta, que fica depois da extração de óleo, é um resíduo sólido rico em nutrientes e proteínas mas limitada, pois possui vários fatores anti-nutricionais e tóxicos como os ésteres de forbol, mas com enorme potencial para a geração de biogás. Embora existam tecnologias para o desenvolvimento dos usos industriais desta espécie, não existe suficiente quantidade de produção dos frutos por planta e gente que se motive a plantar e colher, para suprir a demanda necessária e ser uma cultura altamente lucrativa.
CARACTERISTICAS SENSORIALES DE UN EMBUTIDO AHUMADO A PARTIR DE DIFERENTES FORMULACIONES
Authors: Altamirano Rodriguez Danny , Zambrano-Arauz Carlina Daniela , Zambrano-Arteaga Ramón Ignacio , Arteaga-Solórzano Rudyard Antonio 
Published: April 2021

La presente investigación tuvo como objetivo evaluar las características sensoriales de un embutido (longaniza ahumada) a partir de diferentes formulaciones, se establecieron dos formulaciones (Tratamiento menor; Tratamiento mayor) y se utilizó como testigo una longaniza ahumada de tipo artesanal. Se evaluaron los atributos sensoriales de: (Apariencia, Sabor, Textura, Olor y Calidad General) para lo cual se empleó una prueba hedónica de puntos mediante un panel sensorial con catadores no entrenados. Los datos fueron evaluados estadísticamente mediante Shapiro wilk, ANOVA y Análisis no Paramétrico de Kruskal Wallis al 5% de significación. Los resultados demostraron que el Tratamiento mayor tuvo igual característica organoléptica que el Testigo en el atributo textura p-valor<0,05 mientras que los demás atributos no tuvieron significancia estadística p-valor˃0,05. Se establece que la formulación Tratamiento mayor es de igual característica sensorial con la longaniza artesanal en cuanto a la textura, la misma que puede ser empleada para dimensionar su proceso de elaboración a otra escala.