Experimental Assessment of Cement Integrity under Thermal Cycle Loading Conditions in Geopressured Geothermal Reservoirs

The number of well integrity issues increase as wells are exposed to severe downhole conditions and have longer lifetimes. Techniques for heat extraction from geopressured geothermal reservoirs involve production of hot water and injection of cold water which expose downhole materials to harsh cyclic temperature variations. Heating and cooling make the cement expand and contract as a result of thermal expansion. This volumetric change can influence cement sheaths causing them to fail. Failure of annular cement sheaths can introduce well integrity issues and subsequently lead to sustained casing pressure. This study measures the effect of cyclic thermal loading of cement slurry designs in salt brines. Grain volume porosimeter and Liquid Pressure-pulse Decay Permeameter was used to quantify the presence of thermal fractures as it is capable of measuring brine permeability of cement under reservoir conditions. Scanning Electron Microscopy micrographs with Energy Dispersive Spectroscopy capabilities, Thermogravimetric analysis and X-Ray Photoelectron Spectroscopy were used to study the physical and chemical changes in the cement slurry designs. Five cement designs with a range of chemical additive were subjected to 100 thermal cycles of 40⁰C at 100% relative humidity in salt brine. The experimental result indicates leaching of Ca(OH)2 will occur from the cement irrespective of cement composition which causes the porosity and permeability of the cement sheath to increase. Due to the thermal cycling, the strength of the cement sheath decrease. The study also shows that steel fiber can be added to the design to improve the permeability and increase the strength of the cement sheath under thermal cycle loading conditions. Future work is essential in order to fully understand within which temperature ranges a particular well can be operated, without leaks along the annular cement sheaths. This can be obtained by conducting tests varying the different materials in the cement mix. In addition, experimental tests determining the effect of exposing the formation to drilling fluids prior to cementing and further thermal cycling can be conducted. Effect of various wellbore scaling ratios is also important, as the effects of the total volumes on the obtained results are unknown

Twenty-Five Years after Section 72 of Cama Amendments to Pre-Incorporation Contracts Law in Nigeria.

With the recent global economic downturn, International Oil Corporations (IOCs) are increasingly focused on exploring business opportunities in regions with significant projected growth opportunities such as Africa and Asia. Several IOCs have recently flocked to Nigeria, a prominent West African country, with the recent stable political climate, immense population (about 170 million), and projected double digit growth rate, and so the country has quickly become a destination of choice for small and large international companies, alike, seeking to take advantage of the perceived business opportunities therein. Thus, this paper evaluates the current state of common law and statutory amendments governing pre-incorporation contracts in Nigeria within the context of similar rules in the commonwealth countries around the world. It seeks to provide protection to the company, the promoters, the shareholders and the third parties who have entered into pre-incorporation contracts with the promoters prior to the formal incorporation of the company. In making recommendations for amending the current Nigerian statutory law on pre-incorporation contracts, the authors propose rules that must balance the privacy of the company’s contracts while making sure fairness and equity are extended to all stakeholders. Most of the recommendations suggested take into consideration the peculiar economic environment that Nigerian businesses operate within, i.e., where there is paucity of information and where official facts are not almost readily available, hence, the recommendation for a notarized copy of the pre-contract stating its value in the objects and memorandum of association of the company, especially where the value of the pre-incorporation contract is equal or greater than the total value of the allotted shares of the company

Corporate Social Responsibility Disclosure and Financial Performance of Listed Manufacturing Firms in Nigeria

This paper evaluates the impact of corporate social responsibility disclosure (CSRD) on the financial performance of listed manufacturing firms in Nigeria. In specific terms, the paper examined the influence of four CSRD dimensions (human resources, environment, community and product) on the Earnings per Share (EPS) of the sampled firms. The study utilized a sample size of ten (10) manufacturing firms drawn randomly from seven (7) subsectors of the Nigerian manufacturing industry. Secondary data for the study were collected from the financial statements of the sampled firms and analyzed with the aid of multiple regression analysis. The study finds an overall significant positive association between CSRD and EPS. Furthermore, the study reveals that all the four CSRD dimensions (employee, environment, community and product) have significant positive effect on the EPS. This means that the higher the level of CSRD, the higher the EPS. The study therefore, recommends that management of listed manufacturing firms in Nigeria should increasingly approach CSR and CSRD issues with positive mindset thereby recognizing it as investment rather than liability. Finally, the study recommends that the Financial Reporting Council of Nigeria (FRCN) should make social and environment reporting in the companies’ financial statements mandatory since CSRD is beneficial to the government, the listed manufacturing companies and their stakeholders.   Keywords: Corporate Social Responsibility Disclosure (CSRD), Earnings Per share (EPS), Financial Performance, Manufacturing Firms, Stakeholders

Valor taxonómico de la micromorfología de la hoja y la fitoquímica cuantitativa de Jatropha integerrima Jacq. y Jatropha podagrica Hook. (Euphorbiaceae)-conocidas plantas hortícolas en Nigeria

The leaf micro-morphology and quantitative phytochemistry of J. integerrima and J. podagrica were examined to find useful characters for the delimitation of taxa, following standard protocols as described by previous authors. Both species are hypostomatic (paracytic). Trichome (multicellular, non-glandular) are only present on the adaxial surface of J. integerrima and absent in other epidermal surfaces. Phytochemical analysis also showed little differences in the amount of bioactive compounds present in both species. Phenol contents are the highest in the two species: 37.65% in J. integerrima and 36.13% in J. podagrica. The similarities and differences in the foliar epidermal characters and phytochemical content can be used to delimit the two studies species, as taxonomic characters.Se examinó la micromorfología y la fitoquímica cuantitativa de J. integerrima y J. podagrica para para identificar caracteres útiles para la delimitación taxonómica, siguiendo protocolos estandarizados, descritos por autores anteriores. Ambas especies son hipostómicas (paracíticas). Los tricomas (multicelulares, no glandulares) estaban presentes sólo en la superficie adaxial de J. integerrrima y ausentes en otras superficies epidérmicas. Los análisis fitoquímos también señalaron pequeñas diferencias en la cantidad de compuestos bioactivos presentes en ambas especies. El contenido de fenol es el mayoritario en ambas especies: 37.65% en J. integerrima y 36.13% en J. podagrica. Las semejanzas y diferencias de los caracteres epidérmico-foliares y contenidos fitoquímicos puede

Aeropalynological Investigation of the University of Ilorin, Ilorin, Nigeria

Hay fever allergy could either be from pollen or fungi spores. Using the Hirst model of pollen trap, pollen buckets were constructed; with pollen trap solutions inside them, they were placed in specific locations in the University of Ilorin for four months (December 2012/January 2013 to March/April 2013). Using acetolysis reaction, pollens and spores were recovered from the trap solution and were analyzed and identified in the microscope. Pollen/spore were counted and compared with meteorological parameters i.e. rainfall, sunshine, wind speed, humidity, and temperature. It was observed that pollen/spore concentrations were influenced by these meteorological factors. Hence there is need for us to always determine the amount of these pollen/spore concentrations all year round as it will help to predict the vegetation of a given area as well as helping hay fever sufferers manage their allergies effectively

Dimensions of Vaccination Attitudes in Nigeria: A Study of the Impacts of COVID-19 Vaccine Risk Perception and Acceptance

Nigeria has been affected by the COVID-19 pandemic, and vaccination is a key strategy. However, the country faces vaccination hesitancy, poor risk perception, and low acceptance. This study aimed to assess the direct and interactive impacts of COVID-19 vaccine risk perception and acceptability on COVID-19 vaccination attitudes in the general Nigerian population. In a cross-sectional approach, participants completed a structured questionnaire including demographics, COVID-19 vaccine risk perception, acceptance, and vaccination attitude from April 2-30, 2021. The sample included 1,026 participants from different ethnicities across four regions (Southwest, South, Southeast, and North Central) in Nigeria, which were selected using the convenience sampling method. Multivariate analysis of variance results showed that the COVID-19 vaccine’s risk perception and acceptability have separate and interactive effects on overall vaccination attitudes. Interactively, individuals with high-risk perceptions and low acceptance expressed more skepticism about its benefits, were concerned about its long-term body effects, believed more in its commercialization, and preferred natural immunity. Nigerians’ apprehension about COVID-19 vaccination is impacted by their high-risk perception and low vaccine uptake

Valor taxonómico de la micromorfología de la hoja y la fitoqímica cunatitativa de Jatropha integerrima Jacq. y Jatropha podagrica Hook. (Euphorbiaceae) - conocidas plantas hortícolas en Nigeria

Valor taxonómico de la micromorfología de la hoja y la fitoqímica cuantitativa de Jatropha integerrima Jacq. y Jatropha podagrica Hook. (Euphorbiaceae)-conocidas plantas hortícolas en Nigeria Se examinó la micromorfología y la fitoquímica cuantitativa de J. integerrima y J. podagrica para para identificar caracteres útiles para la delimitación taxonómica, siguiendo protocolos estandarizados, descritos por autores anteriores. Ambas especies son hipostó- micas (paracíticas). Los tricomas (multicelulares, no glandulares) estaban presentes sólo en la superficie adaxial de J. integerrrima y ausentes en otras superficies epidérmicas. Los análisis fitoquímos también señalaron pequeñas diferencias en la cantidad de compuestos bioactivos presentes en ambas especies. El contenido de fenol es el mayoritario en ambas especies: 37.65% en J. integerrima y 36.13% en J. podagrica. Las semejanzas y diferencias de los caracteres epidérmico-foliares y contenidos fitoquímicos pueden ser empleadas para delimitar taxonomicamente ambas especies.Abstract: The leaf micro-morphology and quantitative phytochemistry of J. integerrima and J. podagrica were examined to find useful characters for the delimitation of taxa, following standard protocols as described by previous authors. Both species are hypostomatic (paracytic). Trichome (multicellular, non-glandular) are only present on the adaxial surface of J. integerrima and absent in other epidermal surfaces. Phytochemical analysis also showed little differences in the amount of bioactive compounds present in both species. Phenol contents are the highest in the two species: 37.65% in J. integerrima and 36.13% in J. podagrica. The similarities and differences in the foliar epidermal characters and phytochemical content can be used to delimit the two studies species, as taxonomic characters

Growth Response of Three Leafy Vegetables to the Allelopathic Effect of <i>Vitellaria paradoxa</i>

<p>This study was conducted to evaluate the growth response of three leafy vegetables (<em>Celosia argentea</em>, <em>Amaranthus cruentus </em>and <em>Amaranthus hypochodriacus</em>) to the leaf extract of <em>Vitellaria paradoxa.</em> Forty-five (45) experimental plastic containers were filled with 5 kg of loamy soil each and randomly allocated to the following regimes: control, 20 g, 40 g, 60 g and 80 g of powdered leaves of <em>V. paradoxa</em>, in three (3) replicates for each test crop respectively.<em> </em>It was observed that the response of the three leafy vegetables, grown within different composition of <em>V. paradoxa</em> leaves, are concentration dependent with respect to the studied growth parameters (plant height, leaf number, leaf area, stem girth). This indicated that <em>V. paradoxa </em>has allelopathic potential on the studied vegetables and therefore it could be used for natural weed control.</p

Growth Response of Three Leafy Vegetables to the Allelopathic Effect of &lt;i&gt;Vitellaria paradoxa&lt;/i&gt;

This study was conducted to evaluate the growth response of three leafy vegetables (Celosia argentea, Amaranthus cruentus and Amaranthus hypochodriacus) to the leaf extract of Vitellaria paradoxa. Forty-five (45) experimental plastic containers were filled with 5 kg of loamy soil each and randomly allocated to the following regimes: control, 20 g, 40 g, 60 g and 80 g of powdered leaves of V. paradoxa, in three (3) replicates for each test crop respectively. It was observed that the response of the three leafy vegetables, grown within different composition of V. paradoxa leaves, are concentration dependent with respect to the studied growth parameters (plant height, leaf number, leaf area, stem girth). This indicated that V. paradoxa has allelopathic potential on the studied vegetables and therefore it could be used for natural weed control

Fruit Morphology as Taxonomic Features in Five Varieties of Capsicum annuum L. Solanaceae

Variations in the fruit morphological features of Capsicum annuum varieties were studied. Varieties studied include var. abbreviatum, var. annuum, var. accuminatum, var. grossum, and var. glabriusculum. The fruit morphology revealed attenuated fruit shape with rounded surfaces in var. glabriusculum, and cordate fruit shape with flexuous surface in var. annuum, abbreviatum and accuminatum. The fruit is a berry and may be green, yellow, or red when ripe. The fruit epidermal cell-wall patterns are polygonal in shape with straight and curved anticlinal walls in all the five varieties. The fruit of var. abbreviatum and var. grossum is trilocular, while that of var. accuminatum and annuum is bilocular, and that of var. glabriusculum is tetralocular. Capsicum annuum var. glabriusculum had the highest mean number of seeds (108.4) and var. annuum had the lowest number of seeds (41.3) per fruit. The fruit is conspicuously hollowed in var. glabriusculum, accuminatum, and annuum but inconspicuously hollowed in var. abbreviatum and var. grossum. These features are shown to be good taxonomic characters for delimiting the five varieties of Capsicum annuum