Adsorption of carbon dioxide and methane on alkali metal exchanged silicoaluminophosphate zeolite

Aluminosilicate zeolites remain the most widely used microporous materials for important industrial gas separation applications. Aluminophosphate molecular sieves (AlPO-n) are the first microporous materials synthesized without silica. Substitution of silica in the AlPO-n framework result in the formation of silicoaluminophosphate (SAPO-n) molecular sieve. In this study, Na-SAPO-34 zeolite was synthesized and ion exchanged with alkali metal cations (K+ and Li+) using a two-step ion exchange procedure, with each step lasting for 24 hours. The prepared materials were characterized using X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), inductive coupled plasma optical emission spectroscopy (ICP-OES), and Fourier transform infrared spectroscopy (FTIR). Thermal analysis was carried out using thermographymetric analyzer (TGA) and differential scanning calorimetry (DSC). The textural properties (surface area, pore size and pore volume) were calculated from N2 adsorption isotherm at 77 K. Equilibrium adsorption isotherms and adsorption capacity were measured volumetrically at 273, 298 and 323 K respectively for CO2 and at 298 K for CH4 at pressure of 101.3 KPa. The corresponding isosteric heats of adsorption of CO2 was calculated using the Clausius-Claperon equation. The Langmuir, Freundlich and Sips models were applied to correlate the adsorption isotherm data. The equilibrium performance of the prepared materials for CO2 separation from CO2/ CH4 mixtures operating at room temperature were calculated based on working capacity, regenerability and selectivity. The results showed that although all the prepared materials show changes in structural properties, the structure did not collapse after ion exchange. All the prepared materials showed high preference for CO2 over CH4. At 273 K, the 1st stage K+ ion exchange material had the highest CO2 adsorption capacity (2.90 mmol/g), whereas at 323 K, the 1st stage Li+ material had the highest capacity (1.90 mmol/g). However, at 298 K, the adsorption capacity did not improve. The 1st stage K+ material had highest adsorption capacity for CH4 (0.54 mmol/g) at 298 K. Sips model provides the best fit with experimental data. The 1st stage K+ ion exchange material had the highest heat of adsorption reflecting stronger interaction between the extra framework cation and CO2. Based on the adsorbent performance evaluation, all the prepared materials showed potential for CO2 removal from CO2/ CH4 mixtures at room temperature with the exception of the 2nd stage K+ ion exchange material. The lithium ion exchange series had higher working capacity and regenerability than the potassium ion exchanged series at 298 K. This study showed that adsorption capacity of CO2 and CH4 depends not only on temperature but also on the properties of the exchangeable cation such as size, charge, location, and distribution within the channels and cavities of the prepared materials

Lipoma of the transverse colon: Review of literature and a case report in a young Nigerian female

Colonic lipomas are rare benign tumour of the gastrointestinal tract(GIT); however, they remain the commonest nonepithelial(mesenchymal) benign neoplasm of the GIT tract. The majority remains asymptomatic. They can mimic malignant tumours of the GI tract. We present a review of literature and our experience with the management of a case of this rare tumour. A 35year old woman presented to us with an upper abdominal pain of six  weeks,vomiting and passage of bloody  mucoid stool of four weeks. A huge palpable mass in the epigastric region.  Contrast-enhanced Computed tomography revealed a well-defined, 18cm, fatty tissue mass in the transverse colon. She had a right hemicolectomy. Histology confirmed the diagnosis revealing a submucous lipoma. One year follow up, she remained symptom-free with no evidence of recurrence. This study raises the awareness of this rare tumour as a cause of GIT symptoms and highlights the challenges in differentiating it from the more common malignancy of the colon. Keywords: Colonic lipoma, lipoma of transverse colon, Non-epithelial tumour Nigerian femal

Export of Agricultural Raw Materials, Exchange Rate and Economic Growth in Nigeria: An ARDL Approach to Cointegration

This paper investigated the long run cointegration between export of agricultural raw materials, exchange rate and economic growth in Nigeria. An annual time series data was used for the period of 32 years from 1981 to 2013, and Auto Regressive Distributed Lags (ARDL) cointegration approach was employed in achieving the objective of the study. The result revealed that, both short run and long run models were cointegrated. Agricultural raw material export and exchange rate are instatistically and negatively related to GDP with the exception of exchange rate. Therefore, this paper suggested as part of its policy recommendation that, the Federal Republic of Nigeria in line with  its transformation agenda should focus more on human capital, infrastructural and agricultural sector development, and not only increase export of agricultural raw materials, but also encourage exportation of processed agricultural products for achieving inclusive economic growth and development. Keywords: Agricultural raw materials export, Exchange rates, GDP, ARDL cointegration, Nigeria.

Solid pseudopapillary neoplasm of the pancreas in Sub-Saharan Africa: A case report and review of literature

Solid pseudopapillary neoplasm of the pancreas is a rare indolent malignant tumor mostly found in young women in the second and third decades of life. Only about 3000 cases have been reported in English literature, with none in the West African region. Here, we report to the best of our knowledge, the first histologically confirmed case of solid pseudopapillary neoplasm of the pancreas in West Africa. A 29-year-old woman with a slow-growing left upper abdominal mass of 10 months. Abdominal ultrasound and computed tomography scans revealed a cystic-solid mass arising from the tail of the pancreas. She underwent surgical excision of the mass, with post-operative histopathology findings in keeping with solid pseudopapillary neoplasm of the pancreas. This case report highlights the importance of improved abdominal imaging, histopathology and the need for increased awareness as a differential diagnosis of an intra-abdominal tumor, especially in young women

Reliability, Availability, Maintainability, and Dependability Analysis of Cold Standby Series-Parallel System

This paper dealt with the evaluation reliability, availability, maintainability, dependability, mean time between failures, and mean time to failure of series-parallel system. The system under investigation has four subsystems, namely subsystem A containing two units in cold standby, subsystem B and C possess one unit each, and subsystem D has two units in cold standby. Through the transition diagram of each subsystem and the Markov birth–death process, Chapman Kolmogorov forward equations are derived. Both failure and repair rates of units in each subsystem are assumed to follow exponential distribution. The objective is to derive the corresponding reliability models of dependability, availability, maintainability, and reliability and capture the effect of system parameters on reliability, availability, maintainability, and dependability and to determine the critical subsystems. On the basis of numerical results obtained, the system’s performance has been evaluated. Moreover, the outcome of this study shows that the ideal system reliability can be achieved when the overall system failure rate is low and the supporting units are activated

Broadening Nigeria’s Revenue Base: Exploring Blue Economy Activities

The study explores appropriate mechanism for diversifying Nigeria’s revenue to tap from the opportunities offered by the blue economy. The study conceptually reviewed extant literature as a basis for acquiring an in depth understanding of the phenomenon with a view to offer practical recommendations on the issue. The study discovered that blue economy has the potential of augmenting government revenue if the financial and environmental issues bedeviling the development of the sector are properly addressed. Thus, the study recommends political will and strong institutions for effective running and implementation of blue economy strategies in the nation based on the existing international standards. It also suggested that, to boost revenue from blue economy, Area-based Management needs to be established

Premium arrangement in the contemporary real estate transaction in Bauchi

The premium arrangement in the real estate enables lessors to receive a lump sum of money and forfeit a part of rental income, while the lessee enjoys some profit rents. This transaction was not operational in the study area. This study investigated the position of the lessor on the awareness and practice of premium arrangement on the real estate transaction in Bauchi metropolis, using multiple regression and structural equation modelling with AMOS graphics. The analyses (both) multiple regression and structural equation modelling with AMOS revealed that the awareness and practice of premium arrangement in Bauchi metropolis have been a factor that can significantly influence the real estate transactions with corresponding benefits to both lessors and lessees in the study area. It was therefore recommended that the parties’ privy in the premium transaction to acknowledge the benefits to the lessor appeared to out-weigh the benefits to the lessee, thus the parties should be enjoined to comply with the existing rules and covenants of their leas

SWOT analysis of land area-based and value-based property rating

The property rating can be on Value-based rating Assessment (VbRA) or Area-based Rating Assessment (AbRA). This study examined the suitable assessment of Bauchi metropolis, Nigeria. The materials used were published books and journal articles, and SWOT technique was applied to analyse the identified variables, then the strengths, weaknesses, opportunities and threats were sorted out. The facts from the SWOT matrix were assimilated into existing local scenario to strategically decide the appropriate assessment procedure for raising the local revenue for financing the provision and maintenance of municipal infrastructure and facilities. The study found Area-based Rating Assessment (AbRA) as the most appropriate rating assessment procedure for the study area

Fishers ICTs use for early warning reception, it’s effect on Livelihood Resilience and sustainability in East Coast Malaysia

Climate change is posing a serious threat to agriculture and hence food security of nations. Achieving sustainable development goals (SDGs) is thus contingent on adaptation measures that are aimed to reduce vulnerability and build resilience. The ICTs are recognized for strengthening Livelihood Resilience (LR), by providing the necessary support for learning process, flexibility in operations or actions and robustness for continued functionality. Yet, empirical literature is scarce on the effect it has on LR, The research while filling this gap, claims initial application of Protective Motivation Theory to assess the effect of ICTs on LR of agricultural communities like Fisher Folks in Malaysia. Findings reveals Social networking as the main reason for use of ICTs by fisher folks, while early warning dissemination is always channelled through radio with other ICTs complementing. The Multiple Regression revealed additional source of income, threat appraisals (perceived vulnerable and severity of flood), coping appraisal of (self-efficacy) to be key determinants of adaptive behaviour and hence are precursor for LR. Thus it can be said that both ICTs Use and PMT constructs affect the LR, suggesting a focus on innovative use of ICTs for adaptation motivation in flood risk reduction communication

Underlying structure of job competency scale in climate-smart agricultural extension service

Climate change could reduce agricultural productivity in lower latitude communities, thereby threatening the food security and livelihoods of farm families. Climate smart agriculture (CSA) has been identified as an approach that could sustainably enhance productivity and mitigate the exacerbating effect of climate change on agriculture. For CSA technologies to be accepted, there is a need for special advisory services delivered by competent extension agents. This study assessed the structure of such competencies among 341 Malaysian extension workers selected randomly. The data obtained from a structured questionnaire was subjected to Varimax rotation of the principal component analysis. The KMO obtained was 0.847 while Bartlett's Test was significant (p < 0.001). Assessment of internal consistency revealed a Cronbach alpha of 0.926. Using Kaiser's criterion, seven components explaining 76.053% variance were extracted. However, parallel analysis streamlined and retained five components. This implied that CSA competency among Malaysian extension workers had a five component structure. This should be taken into consideration when designing trainings to make sure the relevant aspects are covered. It could also be beneficial in climate change adaptation and mitigation programmes