Laboratory Scale Experimental Analysis of the Effect of Surfactants on Acid Mist Suppression during Copper Electrowinning

The reduction in acid mist generation is an industrial occupational objective in the electrowinning industry of base metals. The technology of electrowinning as an extractive metallurgical technique of metals proficiently contributed to the recovery of pure base metals. During the process of electrowinning, oxygen bubbles are generated on the anode of the electrowinning cell because of the over potential in the cell due to high voltage. The bubbles formed tend to contain sulfuric acid of the electrolyte in the form of liquid-gas ascending particles of the solution. As these bubbles ascend to the surface of the solution, they burst at the solution-air interface due to the surface tension effect, thus emitting acidic vapors (acid mist) into the atmosphere which poses health problems to workers in the electrowinning tank house. To reduce the amount of acid mist produced during electrowinning, chemical additives (surfactants) are used to affect the surface tension of the electrolyte to suppress the bubbles bursting at the surface of the electrolyte. The most common surfactant used in the copper electrowinning industry was 3M Acid Mist Suppressant FC-1100. The manufacturing of this surfactant has been discontinued by the manufacturer due to environmental issues. As such, a replacement for FC – 1100 was keen through our study. To find a replacement for FC – 1100, this study conducted a laboratory evaluation of several surfactants using aerosol sampling above an electrolyte sparged with oxygen, phase separation during solvent extraction, and electrowinning. Results generated from the study showed a possible replacement for the FC – 1100 which is no longer available to the electrowinning industry -- Abstract, p. ii

Experiences of Nurses and Midwives during the Ebola Outbreak in Liberia, West Africa

The 2014 – 2015 Ebola outbreak in the West African region resulted in many deaths and has been responsible for devastating health and socioeconomic upheaval. The decision of nurses and midwives whether or not to render care during outbreaks is vital for the containment of the disease. The purpose of this study was to explore the experiences of nurses and midwives during the Ebola outbreak in Liberia. A grounded theory method based on Corbin and Strauss (2015) and Charmaz (2014) was used, resulting in a conceptual model describing the process involved in the work decisions made by the study participants. A convenience sample of 30 registered nurses and registered midwives were recruited from three hospitals (10 from each hospital). One of the hospitals was private faith-based, one was private faith-based and received funds from the government, and the third was government managed. Using an interview guide, data were collected through face-to-face, semi-structured, and tape-recorded interviews. The core category identified in the data was “living in fear and terror.” Other categories identified in the data were family, professionalism, God and safety, institutional influences, government efforts, and stigmatization. The work decisions of nurses and midwives were primarily influenced by family responsibilities and demands. The nurses and midwives experienced changes in the dynamics of the nurse-patient relationship and in the nurse-nurse relationship, depending on whether or not they continued working. The findings of this study could be applied to education, practice, research, and health policies related to future disease outbreaks in Liberia and other regions in the world. Nursing curricula should include Ebola nursing care. An intervention study could be designed to test modes of safe touch with patients and the ramifications for practice. The role that faith plays in the decisions made by nurses and midwives should be recognized. Administrators and policy makers need to consider the emotional needs associated with the family, isolation, and stigmatization of nurses and midwives when developing measures and policies for Ebola containment

Determinants of Economic Growth and Poverty Minimization in Liberia: An ARDL Approach

This paper analyses factors that influenced GDP growth rate in Liberia from 1980 to 2015. To carry out this analysis, we used time series data gathered from the World Development Indicators and the African Development Indicators. Applying the advanced autoregressive distributed lags estimation technique to our model, we found that international trade openness, foreign direct investment inflows, changes in the official exchange rate, and political/economic instability have been the main factors influencing GDP growth rate in Liberia over the period studied. The findings further reveal that a rise in international trade openness and official exchange rate have negative effects on GDP growth rate in the short run, but the effects are positive in the long run respectively. FDI inflows and political/economic instability were separately found to have a negative effect on GDP growth rate in the long run. Policy measures as to how to facilitate GDP growth and how to make that growth serve as a tool for poverty minimization are briefly discussed. Keywords: GDP Growth rate; trade openness, poverty minimization, Liberia, Open Door Policy. JEL Classification: O47, F43, C32  

Contributions to the Specific Heat Capacity of Nickel, Iron, and the Alloy Ni\u3csub\u3e3\u3c/sub\u3eFe

The specific heat capacity at constant pressure Cp of a ferromagnetic solid is assumed separable into six contributions - that due to the dilation of the lattice Cd, that due to the harmonic oscillations of the atoms Cvh, that due to the anharmonic oscillations of the electrons Cva, that due to changes in energy distributions of the electrons Cve, that due to changes in the magnetic coupling among the electrons Cvm, and that due to atomic rearrangements Cvw. Expressions appearing in the literature for these contributions, which are assumed to be independent, are reviewed and the validity of each is discussed. Specific heat capacity measurements performed in one of two pulse calorimeters are presented for iron, nickel, and ordered and disordered Ni3Fe from 300 to 1400 K. Pulse Calorimeter II, having been developed during this research, is described in detail. Primary attributes of this apparatus are accurate and simultaneous measurement of the specific heat capacity (±1.05%) and electrical resistivity (±0.48%) at temperature intervals of 0.2 degree while the specimen is heated 100 to 600 degrees above its initial temperature at rates of 5 to 60 degrees/second. All specimens are in the form of rods (0.3-cm nominal diameter) and are of purity greater than 99.8%, contain no voids, and have a minute trace of second phase - possibly an oxide. Comparison of the Cp values on nickel and iron with those in the literature indicates two regions of significant disagreement - at high temperatures and near the Curie temperature Tc of each. Both of these discrepancies are attributed to experimental errors in thermometry and/or methodology. Examples for nickel in iron encountered in this work are given to illustrate these errors. Expressions for Cvd, Cvh, Cva, and Cve are chosen from the literature and used in conjunction with the Cp data of this investigations to calculate Cvm of nickel and iron as a function of temperature T. Some of the parameters requisite to these expressions are taken from the literature and some are obtained from the data treatment. The latter parameters are found to be in reasonable agreement with theory. The Cvm values calculated for nickel and iron are within experimental error of literature values based on experimental calculations. Appropriate integrations of the Cvm: T relationships yield values of the magnetic energy Uvm and entropy Svm which are in agreement with experimental and theoretical treatments of the literature of both materials. Values of the discontinuity ΔCvm in Cvm at the Curie temperature Tc agree with theoretical predictions for this second-order transformation. Plots of Cvm for nickel and iron versus log10 |T - Tc| do not demonstrate the behavior expected of critical phenomena. The Cp of Ni3Fe is found to be a function of the thermal history and temperature of the specimen and of the experimental heating rate for temperatures between 750 and 1050 K. Below 750 K, the Cp decreases as the long-range order of the alloy increases. From theoretical interpretations of Cp data of this investigation for ordered and disordered Ni3Fe between 1.2 and 4.4 K, this change is attributed to a decrease of the density of electron states and to an increase of the Debye temperature upon ordering. Use of rapid heating rates allows measurements on ordered structures of Ni3Fe at temperatures where they are metastable, These measurements reveal that the Curie transformation of a highly ordered metastable structure of Ni3Fe is 70 degrees above that of the disordered structure and that the order-disorder transformation can be suppressed to temperatures 230 degrees above the equilibrium transformation temperature using heating rates of 60 degrees/second. In spite of the suppression, it is possible to calculate Cvm only for the disordered structure of Ni3Fe because the ordered structures could not be maintained to high enough temperatures for completion of the Cvm analysis. The Cvm:T relationship for the disordered structure is obtained in the manner analogous to that for nickel and iron. Values of Uvm and Svm found from these calculations are in excellent agreement with theoretical predictions, whereas the ΔCvm value is not. The energy associated with transforming completely ordered Ni3Fe to completely disordered Ni3Fe at the equilibrium temperature is calculated. Only estimates of the entropy of this transformation could be made since the transformation is carried out in an irreversible manner. The values of the energy and entropy are within experimental error of those found in the literature. Recommendation for further research are listed

EFFECTS OF INCOME DIVERSIFICATION ON FINANCIAL PERFORMANCE OF COMMERCIAL BANKS LISTED IN SIERRA LEONE

The aim of this study was to determine the effect of income diversification on the financial performance of commercial banks in Sierra Leone. A descriptive research design was adopted. A census targeting the listed commercial banks in Sierra Leone from the year 2018 to 2022 was conducted. The statistical significance of each independent variable was tested by performing a t-test at a 5% level of significance. The significance of the regression model was tested by performing an F-test at a 5% significance level. The independent variables' explanatory power was evaluated using the coefficient of determination, R^2. The study found that income diversification was negatively related to financial performance. The results of the t-test indicated that the effect was not statistically significant. It also found that size and capital adequacy had a positive effect, which was statistically significant, while liquidity had a negative impact on financial performance and was not statistically significant. The coefficient of determination for the regression was found to be 35.7%. This implies that the independent variable explained only 35.7% of the changes in the dependent variable. The study concluded that income diversification is a costly affair for commercial banks since it has a negative impact on financial performance. It also concluded that size and capital adequacy had a positive impact on financial performance while liquidity had a negative impact. This study recommends that commercial banks should not commit resources to diversifying their income because diversification appears to be a costly affair. Also, investors should not be concerned about a bank’s income diversification in selecting investment opportunities as diversification of income does not generate positive financial performance.EFFETS DE LA DIVERSIFICATION DES REVENUS SUR LA PERFORMANCE FINANCIÈRE DES BANQUES COMMERCIALES COTÉES EN SIERRA LEONEL'objectif de cette étude était de déterminer l'effet de la diversification des revenus sur la performance financière des banques commerciales en Sierra Leone. Un plan de recherche descriptif a été adopté. Un recensement ciblant les banques commerciales cotées en Sierra Leone de l'année 2018 à 2022 a été réalisé. La signification statistique de chaque variable indépendante a été testée en effectuant un test t à un niveau de signification de 5 %. La signification du modèle de régression a été testée en effectuant un test F à un niveau de signification de 5 %. Le pouvoir explicatif des variables indépendantes a été évalué en utilisant le coefficient de détermination, R^2. L'étude a révélé que la diversification des revenus était négativement liée à la performance financière. Les résultats du test t ont indiqué que l'effet n'était pas statistiquement significatif. Il a également été constaté que la taille et l'adéquation des capitaux avaient un effet positif, qui était statistiquement significatif, tandis que la liquidité avait un impact négatif sur la performance financière et n'était pas statistiquement significative. Le coefficient de détermination pour la régression a été trouvé à 35,7 %. Cela implique que la variable indépendante expliquait seulement 35,7 % des changements de la variable dépendante. L'étude a conclu que la diversification des revenus est une affaire coûteuse pour les banques commerciales car elle a un impact négatif sur la performance financière. Il a également conclu que la taille et l'adéquation des capitaux avaient un impact positif sur la performance financière tandis que la liquidité avait un impact négatif. Cette étude recommande que les banques commerciales ne devraient pas engager de ressources pour diversifier leurs revenus car la diversification semble être une affaire coûteuse. De plus, les investisseurs ne devraient pas se préoccuper de la diversification des revenus d'une banque dans la sélection des opportunités d'investissement car la diversification des revenus ne génère pas de performance financière positive.EFFETTI DELLA DIVERSIFICAZIONE DEI REDDITI SULLA PERFORMANCE FINANZIARIA DELLE BANCHE COMMERCIALI ELICOTTE IN SIERRA LEONELo scopo di questo studio era determinare l'effetto della diversificazione dei redditi sulla performance finanziaria delle banche commerciali in Sierra Leone. È stato adottato un disegno di ricerca descrittivo. È stato condotto un censimento mirato alle banche commerciali elencate in Sierra Leone dal 2018 al 2022. La significatività statistica di ciascuna variabile indipendente è stata testata eseguendo un test t al livello di significatività del 5%. La significatività del modello di regressione è stata testata eseguendo un test F al livello di significatività del 5%. Il potere esplicativo delle variabili indipendenti è stato valutato usando il coefficiente di determinazione, R^2. Lo studio ha scoperto che la diversificazione dei redditi era negativamente correlata alla performance finanziaria. I risultati del test t hanno indicato che l'effetto non era statisticamente significativo. Si è anche scoperto che la dimensione e l'adeguatezza di capitale avevano un effetto positivo, che era statisticamente significativo, mentre la liquidità aveva un impatto negativo sulla performance finanziaria e non era statisticamente significativa. Il coefficiente di determinazione per la regressione è stato trovato essere del 35,7%. Ciò implica che la variabile indipendente spiegava solo il 35,7% delle variazioni della variabile dipendente. Lo studio ha concluso che la diversificazione dei redditi è una questione costosa per le banche commerciali poiché ha un impatto negativo sulla performance finanziaria. Ha anche concluso che la dimensione e l'adeguatezza di capitale avevano un impatto positivo sulla performance finanziaria mentre la liquidità aveva un impatto negativo. Questo studio raccomanda che le banche commerciali non dovrebbero impegnare risorse per diversificare i loro redditi perché la diversificazione sembra essere una questione costosa. Inoltre, gli investitori non dovrebbero preoccuparsi della diversificazione dei redditi di una banca nella selezione delle opportunità di investimento poiché la diversificazione dei redditi non genera una performance finanziaria positiva.EFECTOS DE LA DIVERSIFICACIÓN DE INGRESOS EN EL RENDIMIENTO FINANCIERO DE LOS BANCOS COMERCIALES ENUMERADOS EN SIERRA LEONAEl objetivo de este estudio fue determinar el efecto de la diversificación de ingresos en el rendimiento financiero de los bancos comerciales en Sierra Leona. Se adoptó un diseño de investigación descriptivo. Se realizó un censo dirigido a los bancos comerciales enumerados en Sierra Leona desde el año 2018 hasta el 2022. La significancia estadística de cada variable independiente se probó realizando una prueba t a un nivel de significancia del 5%. La significancia del modelo de regresión se probó realizando una prueba F a un nivel de significancia del 5%. El poder explicativo de las variables independientes se evaluó utilizando el coeficiente de determinación, R^2. El estudio encontró que la diversificación de ingresos estaba relacionada negativamente con el rendimiento financiero. Los resultados del test t indicaron que el efecto no era estadísticamente significativo. También se encontró que el tamaño y la adecuación de capitales tenían un efecto positivo, que era estadísticamente significativo, mientras que la liquidez tenía un impacto negativo en el rendimiento financiero y no era estadísticamente significativa. El coeficiente de determinación para la regresión se encontró que era del 35,7%. Esto implicaba que la variable independiente explicaba solo el 35,7% de los cambios en la variable dependiente. El estudio concluyó que la diversificación de ingresos es un asunto costoso para los bancos comerciales ya que tiene un impacto negativo en el rendimiento financiero. También concluyó que el tamaño y la adecuación de capitales tenían un impacto positivo en el rendimiento financiero mientras que la liquidez tenía un impacto negativo. Este estudio recomienda que los bancos comerciales no deberían comprometer recursos para diversificar sus ingresos porque la diversificación parece ser un asunto costoso. Además, los inversores no deberían preocuparse por la diversificación de ingresos de un banco en la selección de oportunidades de inversión ya que la diversificación de ingresos no genera un rendimiento financiero positivo.EFEITOS DA DIVERSIFICAÇÃO DE RENDA NO DESEMPENHO FINANCEIRO DOS BANCOS COMERCIAIS LISTADOS NA SERRA LEONEO objetivo deste estudo foi determinar o efeito da diversificação de renda no desempenho financeiro dos bancos comerciais na Serra Leoa. Foi adotado um desenho de pesquisa descritivo. Foi realizado um censo direcionado aos bancos comerciais listados na Serra Leoa do ano de 2018 a 2022. A significância estatística de cada variável independente foi testada realizando um teste t a um nível de significância de 5%. A significância do modelo de regressão foi testada realizando um teste F a um nível de significância de 5%. O poder explicativo das variáveis independentes foi avaliado usando o coeficiente de determinação, R^2. O estudo descobriu que a diversificação de renda estava negativamente relacionada ao desempenho financeiro. Os resultados do teste t indicaram que o efeito não era estatisticamente significativo. Também foi constatado que o tamanho e a adequação de capitais tiveram um efeito positivo, que foi estatisticamente significativo, enquanto a liquidez teve um impacto negativo no desempenho financeiro e não foi estatisticamente significativa. O coeficiente de determinação para a regressão foi encontrado como 35,7%. Isso implicava que a variável independente explicava apenas 35,7% das mudanças na variável dependente. O estudo concluiu que a diversificação de renda é um assunto custoso para os bancos comerciais, pois tem um impacto negativo no desempenho financeiro. Também concluiu que o tamanho e a adequação de capitais tiveram um impacto positivo no desempenho financeiro, enquanto a liquidez teve um impacto negativo. Este estudo recomenda que os bancos comerciais não devem comprometer recursos para diversificar sua renda, pois a diversificação parece ser um assunto custoso. Além disso, os investidores não devem se preocupar com a diversificação de renda de um banco na seleção de oportunidades de investimento, pois a diversificação de renda não gera desempenho financeiro positivo.ΕΠΙΠΤΩΣΕΙΣ ΤΗΣ ΠΟΙΚΙΛΙΟΠΟΙΗΣΗΣ ΤΩΝ ΕΣΟΔΩΝ ΣΤΗΝ ΟΙΚΟΝΟΜΙΚΗ ΕΠΙΔΟΣΗ ΤΩΝ ΕΜΠΟΡΙΚΩΝ ΤΡΑΠΕΖΩΝ ΠΟΥ ΕΙΝΑΙ ΚΑΤΑΤΕΘΕΙΣΜΕΝΕΣ ΣΤΗ ΣΙΕΡΑ ΛΕΟΝΕΣκοπός αυτής της μελέτης ήταν να καθοριστεί η επίδραση της ποικιλίας των εσόδων στην οικονομική απόδοση των εμπορικών τραπεζών στη Σιέρρα Λεόνε. Ένα περιγραφικό σχέδιο έρευνας υιοθετήθηκε. Πραγματοποιήθηκε ένας απογραφή που στόχευε στις εμπορικές τράπεζες που είναι καταχωρημένες στη Σιέρρα Λεόνε από το έτος 2018 έως το 2022. Η στατιστική σημαντικότητα κάθε ανεξάρτητης μεταβλητής ελέγχθηκε με εκτέλεση ενός τ-τεστ σε επίπεδο σημαντικότητας 5%. Η σημαντικότητα του μοντέλου παλινδρόμησης ελέγχθηκε με εκτέλεση ενός F-τεστ σε επίπεδο σημαντικότητας 5%. Το εξηγητικό δυναμικό των ανεξάρτητων μεταβλητών αξιολογήθηκε χρησιμοποιώντας το συντελεστή προσδιορισμού, R^2. Η μελέτη διαπίστωσε ότι η ποικιλία των εσόδων ήταν αρνητικά σχετιζόμενη με την οικονομική απόδ JEL: G21, G28, L25, O16  Article visualizations

Determinants of Tax Revenue in Liberia: An Empirical Investigation

The need for the Liberian government to mobilize sufficient revenue for development is becoming increasingly important amid slow growth, increasing demand for infrastructure and citizens’ needs. This paper determines the factors that are likely to drive tax revenue performance. We gathered monthly time series data and employed the Johansen cointegration approach and VECM estimation technique. The empirical results reveal that, in the long run, tax revenue responds positively to real property, income and profit, property income, goods and service tax, administrative fees, import duties, excise tax, grant, loan, inflation and GDP Growth. Conversely, tax revenue responds negatively to social development contribution from agriculture and mining, real exchange rate and population growth.  Given these findings, we recommend, among others, that Liberia over-reliance on direct tax (i.e., PIT and CIT) revenue be mitigated. In particular, we recommend the adoption of a VAT regime in the place of the current GST regim

Reproductive health services for refugees by refugees in Guinea I: family planning.

BACKGROUND: Comprehensive studies of family planning (FP) in refugee camps are relatively uncommon. This paper examines gender and age differences in family planning knowledge, attitudes, and practices among Sierra Leonean and Liberian refugees living in Guinea. METHODS: In 1999, a cross-sectional survey was conducted of 889 reproductive-age men and women refugees from 48 camps served by the refugee-organised Reproductive Health Group (RHG). Sampling was multi-stage with data collected for socio-demographics, family planning, sexual health, and antenatal care. Statistics were calculated for selected indicators. RESULTS: Women knew more about FP, although men's education reduced this difference. RHG facilitators were the primary source of reproductive health information for all respondents. However, more men then women obtained information from non-health sources, such as friends and media. Approval of FP was high, significantly higher in women than in men (90% vs. 70%). However, more than 40% reported not having discussed FP with their partner. Perceived service quality was an important determinant in choosing where to get contraceptives. Contraceptive use in the camps served by RHG was much higher than typical for either refugees' country of origin or the host country (17% vs. 3.9 and 4.1% respectively), but the risk of unwanted pregnancy remained considerable (69%). CONCLUSION: This refugee self-help model appeared largely effective and could be considered for reproductive health needs in similar settings. Having any formal education appeared a major determinant of FP knowledge for men, while this was less noticeable for women. Thus, FP communication strategies for refugees should consider gender-specific messages and channels

Impact of Treasury Single Account (TSA) on Public Sector Performance in Sierra Leone for the 2015-2022

The study explores the impact of Treasury Single Account (TSA) on the performance of public sector in Sierra Leone. This study primarily examined the extent to which TSA has improved Government Collected Revenue (GCR) and Government Expenditure (GE) of the public sector. Secondary data that were sourced from the Ministry of Finance Sierra Leone were used for this research. The observations were recorded on yearly basis from 2015 to 2022. The data were divided into two periods: Pre TSA period (2015 to 2018) and Post TSA period (2019 to 2022). A pre-post analysis (difference in means test) was carried out using statistical package for social sciences version 25. The findings show that TSA implementation has a positive and significant effect on the revenue mobilization in Sierra Leone. However, further findings revealed that Government Expenditure (GE) significantly increased after the implementation of TSA. The study concludes that implementation of Treasury Single Account (TSA) has improved revenue generation in Sierra Leone. The study recommends that periodic appraisal of each revenue generating sector should be implemented so that some un-performing sectors are expose against the performing sectors

Principles of Midwifery Care during Virulent Outbreaks

In recent past virulent disease outbreaks have ravaged different parts of the world. The impact have been felt worldwide. During these outbreaks health workers are usually at high risk for contracting the infections. Rendering maternal antenatal, intrapartum, and postnatal care can be challenging during these outbreaks. Some of these disease that have debuted fearsome outbreaks in the recent past are described briefly in terms of their characteristics, pathology, and treatments. The struggles involved in containing one of the outbreaks are highlighted. The dilemma that ensued as a result of seeking for balance between obligation, heroic midwifery interventions, and sense of calling have been explored. Special emphasis is accorded to highlighting the experiences of midwives during the recent 2014–2015 Ebola outbreak in West Africa. Recommended principles to guide midwifery practices suitable for sustaining the safety of families needing midwifery care and health care providers rendering midwifery care are described

Management of Insect Pests using Chlorpyrifos Applications at Different Growth Stages of Tomato, Solanum lycopersicum L.

Field studies were conducted in Kumasi, Ghana in the major and minor planting seasons of 2013 to evaluate the effect of chlorpyrifos applications at different growth stages of tomato (Solanum lycopersicum L) for the management of insect pests. The treatments were: Chlorpyrifos at 1.5 ml / 0.5 litre of water applied (i) at the vegetative growth stage only (sprayed vegetative), (ii) at the reproductive growth stage only (starting at 50 % flowering (sprayed reproductive) and (iii) throughout the crop’s growth period (sprayed throughout). A control plot that received only water was also maintained. In both seasons, significantly (P < 0.05) less number of Bemisia tabaci Gennadius and Thrips tabaci Linderman were collected from the insecticide-treated tomato plots than the untreated, control plots, but no significant differences were observed among the treatments in the aggregations of Aphis gossypii Glover and Helicoverpa armigera (Hubner). Chlorpyrifos application in the sprayed throughout plots significantly (P < 0.05) reduced damage to tomato fruits in the major season but not in the minor season. Tomato fruits from the sprayed vegetative and sprayed reproductive plots had comparable damage as the fruits from untreated control plots. Chlorpyrifos application also significantly (P < 0.05) increased yield of tomato from the sprayed throughout plots in both seasons. The best protection to the crop against the insect pests was obtained from weekly applications of chlorpyrifos throughout the growth period of the crop (sprayed throughout plots). Key words: Tomato, Chlorpyrifos, insect pests, management, population dynamic