Search

Abstract This research study is performed on the self-compacting geopolymer concrete (SCGC) combining coal bottom ash (CBA) and metakaolin (MK) as a substitution for GGBFS alone and combined for analysing the fresh properties (slump flow, V-Funnel, and T50 flow), mechanical characteristics (compressive, splitting tensile and flexural strengths) and durability tests (permeability and sulfate attack test). Though, total 195 SCGC samples were made and tested for 28 days. It has been revealed that the consumption of CBA and MK as a substitution for GGBFS alone and combine in the production of SCGC is decreased the workability of SCGC while mechanical characteristics of SCGC are enhanced by utilizing CBA and MK as a substitution for GGBFS alone and combine up to 10%. In addition, the compressive, splitting tensile and flexural strengths were calculated by 59.40 MPa, 5.68 MPa, and 6.12 MPa while using the 5CBA5MK as a substitution for GGBFS in the production of SCGC after 28 days correspondingly. Furthermore, the permeability is decreased by growing the quantity of CBA and MK by the weight of GGBFS alone and jointly in the production of SCGC after 28 days. Besides, the minimum change in length of the SCGC specimen is recorded by 0.062 mm at 7.5MK7.5CBA while the maximum change in length is calculated by 0.11 mm at 10CBA10MK as a substitution for GGBFS at 180 days correspondingly. In addition, the embodied carbon is recorded reduce as the addition of CBA while it is getting higher when the accumulation of MK alone or combined with CBA in SCGC. Besides, response models for prediction were constructed and confirmed using ANOVA at an accuracy rate of 95%. The models' R2 fluctuated from 88 to 99%. It has been observed that the utilization of CBA and MK alone and together up to 10% as substitution for GGBFS in geopolymer concrete provides the best results therefore it is suggested for structural applications.

This paper describes a new class of boundary value fractional-order differential equations of the $ q $-Hilfer and $ q $-Caputo types, with separated boundary conditions. The presented problem is converted to an equivalent integral form, and fixed-point theorems are used to prove the existence and uniqueness of solutions. Moreover, several special cases demonstrate how the proposed problems advance beyond the existing literature. Examples are provided to support the analysis presented.

Lightweight fibre-reinforced concrete integrates the advantages of lightweight aggregates with the strength-enhancing properties of fibres, resulting in a lighter composite with enhanced impact and mechanical performance. However, achieving an optimal balance between structural weight, and performance remains a challenging endeavour. This study investigates the mechanical properties, impact energy absorptions, flexural toughness, and crack resistance of lightweight fibre-reinforced concrete with the coarse aggregate entirely replaced with lightweight expanded clay aggregate (LECA). Concrete mixes containing 0 %, 0.5 %, 0.75 %, and 1.0 % Polypropylene fibre (PPF) and 10 % micro-silica were experimentally investigated. Predictions for concrete mixes with up to 2 % PPF were made using regression models developed from experimental data. The experimental and predicted results were analysed using response surface methodology. The findings reveal significant enhancements of up to 300 % and 570 % in toughness indices I5 and I10 at 1 % PPF, coupled with a 55.4 % increase in residual strength. Furthermore, an optimised slab thickness of 47 mm containing 1.73 % PPF yielded optimal impact energy absorption of 680 J and 2384 J and crack resistance of 3823 MPa and 16279 MPa at service and ultimate loading, respectively. These metrics represent improvements of 4.8, 15.2, 37, and 56 times, respectively, compared to the control samples. These substantial advancements highlight the potential of lightweight fibre-reinforced LECA concrete in engineering applications where balancing impact energy absorption, crack resistance, and structural weight is crucial. This innovative approach promises a transformative impact on the construction industry, paving the way for more efficient and resilient infrastructure.

Traditional randomized clinical trials are regarded as the gold standard for assessing the efficacy of chemotherapy. However, this procedure has drawbacks such as high cost, time consumption, and limited patient exploration of treatment regimens. We develop a multi-objective optimization-based framework to address these limitations and determine the best chemotherapy dosing and treatment duration. The proposed framework uses patient-specific biological parameters to create a mathematical model of cell population dynamics in the patient’s body. The framework employs evolutionary heuristic search methods (simulated annealing and genetic algorithms) and a prescriptive analytics approach to optimize therapy sessions that transition from treatment to relaxation. We carefully adjust the chemotherapy dose during treatment to reduce tumor cells while preserving host cells (such as effector-immune cells). We strategically time the relaxation sessions to aid recovery, considering the ability of tumors and healthy cells to regenerate. We use a combined optimization method to determine the length of the session and the amount of drug to be administered. We compare quadratic and linear optimal control solvers for drug administration while genetic algorithms and simulated annealing are used to optimize session length. This approach is especially important in limited healthcare resources, ensuring efficient allocation while accurately identifying high-risk patients to optimize resource allocation and utilization.

This study aims to create a theoretical model of business sustainability with financial literacy antecedents. The antecedents of financial literacy are intellectual capital and risk attitudes. The research location is in the province of East Java, Indonesia. Batik SMEs are only found in Indonesia because it is a cultural heritage belonging to Indonesia that does not exist in other countries. The sampling technique used was purposive sampling, with 222 respondents from the batik SMEs spread across six cities. The data was taken using a questionnaire on a Likert scale. Data analysis uses SEM (structural equation modeling) with the SmartPLS application. The study results show that risk attitudes toward financial literacy have a positive effect. The effect of financial literacy on the business sustainability of the batik industry has a positive influence. The impact of intellectual capital on the business sustainability of the batik industry has a positive effect. Risk attitudes have no significant positive impact on business sustainability. Financial literacy has yet to be able to mediate intellectual capital’s influence on the batik SME’s business sustainability. This needs to be explored further with further research. Furthermore, financial literacy can mediate risk attitudes towards the business sustainability of batik SMEs.

Although Basalt fibre reinforced concrete (BFRC) has a proven record of outstanding behaviour, concerns regarding the decline in its performance beyond certain content remains a major concern. To address this concern, a varying content of Silica Fume (SF) was introduced into the BFRC mix, and their combined influence on concrete's mechanical and impact resistance was investigated using experimental and Response Surface Analysis (RSA). Using regression models developed from experimental results, 13 responses of statistically designed experiments were predicted. The findings revealed significant improvement in the concrete performance with increases between 28% and 65% in compressive strength, 35%–107% in split tensile strength, 11%–46% in flexural strength and 117%–150% in the impact resistance. Therefore, appropriate proportions of BF and SF can be utilised as an eco-friendly sustainable material in concrete.

Coastal protection structures are essential defenses against wave energy, safeguarding coastal communities. This study aims to refine coastal protection strategies by employing a semicircular breakwater (SBW) model. Through a combination of physical and computational models, the hydrodynamic properties of the SBW under regular wave conditions were thoroughly examined. The primary objectives included delineating the hydrodynamic characteristics of SBWs, developing a computational model to validate experimental findings. Hydrodynamic characteristics of the SBW model were scrutinized across various wave conditions. Experimental testing in a wave flume covered a range of relative water depths (d/h) from 0.667 to 1.667, wave steepness (Hi/L) spanning 0.02 to 0.06 and wave periods ranging from 0.8 to 2.5 s. Notably, analysis of an emerged SBW with d/h = 0.667 revealed superior wave reflection, while an alternative submerged SBW with d/h = 1.000 showed the highest energy loss. These findings are further corroborated by the validation of computational models against experimental outcomes for d/h = 0.667, 1.000, 1.333 and 1.667. Moreover, the investigation of forces revealed an inverse correlation between horizontal forces and wave height, while vertical forces showed nuanced variations, including a slightly decreasing average vertical force with greater relative wave period (B/L) for different immersion scenarios.

Diphtheria, a potentially life-threatening infectious disease, is primarily caused by the bacterium Corynebacterium diphtheriae. This pathogen induces a range of severe symptoms, including respiratory distress, cardiac arrhythmias, and, in extreme cases, fatal outcomes. This paper aim to unravel the transmission dynamics of diphtheria infection within the Caputo fractional derivatives framework, establishing the solutions’ existence and uniqueness. Through forward normalized sensitivity analysis, we scrutinize the key parameters influencing the basic reproduction number, a pivotal metric in understanding and controlling the spread of the disease. The results indicate that reducing the values of the interaction rate, transmission rate, and birth rate plays a key role in curtailing diphtheria transmission. Furthermore, employing an effective numerical tool, we present graphical representations that delineate the influence of various crucial model parameters on infection dynamics.

Fibre-reinforced concrete (FRC) is an emerging construction material. However, improving its mechanical properties using sustainable materials remains a concern. In this paper, a combination of experimental and numerical techniques is applied to investigate the combined influence of kenaf (K) and polypropylene fibre (PPF) on the mechanical properties of KPPFRC. The optimal design component of Response Surface Methodology was utilised with combined fibre content between 0.5% and 2%. The results show a general increase in the mechanical properties with KF being the main contributing factor, and corresponding decreases in all responses with the increase in PPF. Nonetheless, the predicted optimal volume fraction of 1.5% consisting of 1.0 kg kF and 0.51 kg PPF gives a 100%, 174% and 100% rise in compressive, split tensile, and flexural strength respectively compared to the control sample. Hence, these optimal proportions of KF and PPF can be utilised as an eco-friendly sustainable material in concrete.

AbstractRisk oversight by bank boards has become complex due to the evolving nature of risk and thus the need for risk committees to effectively and adequately monitor bank risktaking. The risk taking capability of a financial institution is largely a function of its risk management committee composition. While studies have examined the effect of risk committee dynamics on several organisational variables, few studies examined the relationship between risk committee composition and the risktaking behaviours of banks. However, these few studies are limited to examining the effect of the existence of a standalone risk committee. Hence, the main purpose of this study is to examine the effect of banks’ board risk committee composition on the risktaking behaviour of deposit money banks in Nigeria. The study used a sample of twelve deposit money banks listed on the Nigerian Exchange Group (NGX) from 2009 to 2020. Data were analysed using DriscollKraay’s Robust Standard Errors for Panel Regressions with Cross-Sectional Dependence (SCC) model to address heteroskedasticity and cross-sectional dependence. The results showed that risk committee independence and financial expertise reduce risk-taking. It, therefore, showed that the independence and financial expertise of the risk committee provide the needed competency and independence to effectively monitor risk-taking. The study, therefore, recommends, among others, the review of the composition of the board risk committee to reflect independence and expertise. The study differs from other studies by examining risk committee composition rather than its existence.

The recurring instability of commercial banks’ performance in Nigeria have triggered stakeholders to deploy efforts toward providing solutions where the desired result is yet to be achieved. Consequently, this study examined the moderating effect of bank size on the relationship between interest rate, liquidity, and performance of the banks in Nigeria. An ex-post-facto research design was adopted, where the bank-specific data were sourced from the published annual financial statements of 12 commercial banks listed on the Nigerian Stock Exchange and the macroeconomic data were extracted from the WDI database for a ten-firm-year period from 2011 to 2020. The analysis was done using the panel regression technique with the support of Stata software version 14.2. Findings on the direct effects showed a significant and negative relationship between deposit rate and performance, and both the lending rate and loan-to-deposit ratio have positive and significant relationships with performance. Meanwhile, the intervention effects showed that the bank size has positively moderated the relationship between deposit rate and performance; whereas bank size has negatively moderated the relationship between loan-to-deposit ratio and performance. Therefore, the study recommended that banks should grow their assets to enable them to achieve economies of scale and cost efficiency.

In this paper, we introduce a generalized fractional operator in the setting of Hilfer fractional derivatives, the ψ-Hilfer generalized proportional fractional derivative of a function with respect to another function. The proposed operator can be viewed as an interpolator between the Riemann-Liouville and Caputo generalized proportional fractional operators. The properties of the proposed operator are established under some classical and standard assumptions. As an application, we formulate a nonlinear fractional differential equation with a nonlocal initial condition and investigate its equivalence with Volterra integral equations, existence, and uniqueness of solutions. Finally, illustrative examples are given to demonstrate the theoretical results.

In this paper, advertising competition among m firms is studied in a discrete-time dynamic game framework. Firms maximize the present value of their profits which depends on their advertising strategy and their market share. The evolution of market shares is determined by the firms' advertising activities. By employing the concept of the discrete-time potential games of González-Sánchez and Hernández-Lerma (2013), we derived an explicit formula for the Nash equilibrium (NE) of the game and obtained conditions for which the NE is an overtaking optimal. Moreover, we analyze the asymptotic behavior of the overtaking NE where the convergence towards a unique steady state (turnpike) is established.

This article analyses the death penalty for apostasy. Islam as moral and religious teaching recognizes the existence of such punishment. This can be traced from a number of verses from the Qur'an and the hadith of the Prophet which explain the concept of the death penalty aimed at certain criminal acts (jarimah) such as apostasy. However, is this the true understanding of the hadith to kill apostates? is still relevant to be applied in the present context, especially when the death penalty has received a very harsh response from human rights activists, both at national and international level? As a response to these questions, the writing analyzes the issue using a descriptive analysis method by making the hadith originating from Ibn Abbas as the research object and by using the theory of sunnah tasyri and ghairu tasyri' by Mahmud Syaltut. The comparison with positive law in Indonesia is also made at the end. In summary, the death penalty for apostasy is no longer relevant in the contemporary context. However, there is an exception when an apostate also commits rebellion (bughat) against the state.

The whole world is still shaken by the new corona virus and many countries are starting opting for the lockdown again after the first wave that already killed thousands of people. New observations also show that the virus spreads quickly during the cold period closer to winter season. On the other side, the number of new infections decreases considerably during hot period closer to summer time. The geographic structure of our planet is such that when some countries (in a hemisphere) are in their winter season, others in the other hemisphere are in their summer season. However, we have observed in the world some countries undertaking national lockdown during their summer time, which result in their economy to be hugely hit. Other factors, beside the lockdown, have also impacted negatively the socio-economic situation in affected countries. These include, among others, the human immunodeficiency virus (HIV) susceptible to combine to the new corona virus. The new corona virus is indeed recent and many of its effect and impact on the society are still unknown and are still to be uncovered. Hence we use here the of Atangana-Baleanu fractional derivative to mathematically express and analyses a model of HIV disease combined with COVID-19 to assess the pandemic situation in many countries affected, such as South Africa, United Kingdom (UK), China, Spain, United States of America (USA), and Italy. A way to achieve that is to perform stability and bifurcation analysis. It is also possible to investigate in which conditions the combined model contains a forward and a backward bifurcation. Moreover, utilizing the techniques of Schaefer and Banach fixed point theorems, existence and uniqueness of solutions of the generalized fractional model were presented. Also, the Atangana-Baleanu fractional (generalized) HIV-COVID-19 con-infection model is solved numerically via well-known and effective numerical scheme and a predicted prevalence for the COVID-19 is provided. The global trend shown by the numerical simulation proves that the disease will stabilize at a later stage when adequate measures are taken.

Health volatility due to the Covid-19 pandemic presented a new-fangled trial to the banking industry with a spillover effect of monetary policy volatility, which extremely affected the performance of the banking industry in Nigeria. It has become a matter of concern to assess monetary policy volatility and performance of the banking industry in Nigeria. The paper used annual time series data that spanned the period of 2008 to 2020. The paper employed Autoregressive Distributed Lag (ARDL) and Exponential Generalized Autoregressive Conditional Heteroskedasticity (EGARCH) as its techniques of estimation. Based on the ARDL result, it was exposed that monetary policy volatility had a negative impact on the activities of the banking industry in Nigeria within the study time. In addition, according to the EGARCH test result, the paper generalized that monetary policy volatility had constantly been accompanied by a new volatility. Therefore, as a result of the universal financial predicament experienced in 2008, this caused a higher monetary policy volatility in 2020 in the face of Covid-19. The paper observed that a rise in monetary policy volatility led to a decline in the performance of the banking industry in Nigeria within the study period, and the current monetary policy volatility led to its uncertain volatility in the period ahead. The paper recommended based on the findings that banks through the Central Bank of Nigeria should employ tactical monetary policy strategies to reduce monetary policy volatility during the Covid-19 pandemic toward enhancing the performance of Nigeria’s banking industry.

تعد فترة الحروب الصليبية مرحلة إتصال بين المسلمين والمسيحيين في أوقات الحرب والسلم، لان الطبيعة البشرية فرضت عليهم أن يتقاتلوا أحياناً، وأن يتهادنوا أحياناً آخرى، ففي أوقات السلم كان يتم الإتصال الحضاري ولاسيما التجارة بينهم على نطاق واسع. ويلاحظ مدى تطور الحضارة الاسلامية على الاهتمام الفائق بالخدمات التي تساعد على التبادل التجاري من منشأت وخانات وتخصيص فئات من الناس للخدمات التجارية والإعفاءات الجمركية، فضلاً عن الاعمال المصرفية وسك العملات المختلفة. وكانت أهم العوامل التي حتمت على الطرفين الاسلامي والمسيحي في بلاد الشام ومصر على درجة كبيرة من الاهمية لحياة كل من الجانبين، على الرغم من المواجهة العسكرية التي كانت قائمة بينهما، وهي عوامل بلا ادنى شك ساعدت كثيراً في بعض الاحيان على حدة التوتر أو على الاقل جعلت أهل الحرب ينشغلون بحربهم وأهل التجارة ينشغلون بتجارتهم. وقد تطرقت في هذا البحث الى التجارة في عهد الحروب الصليبية، فقد أشرت الى وسائل الإتصال ما بين الجانبين، إضافة الى السلع التجارية المتبادلة، كذلك ذكرت الطرق التجارية التي يتم من خلالها إيصال المواد ما بين الجانبين.

It has been argued that increasing demand for high compensation by executives and powers in the hand of executives have contributed to increased risk-taking in the banking industry. The study aims to examine the effect of CEO Pay, CEO Ownership Power, and Expert Power on risk-taking of listed deposit money banks in Nigeria. A sample of 12 deposit money banks for the period 2009 – 2019 was studied and analysed using panel regression. The study found that CEO pay and CEO Expert power have no significant effect on risk-taking of listed deposit money banks in Nigeria. In contrast, CEO Ownership power was found to influence risk-taking significantly. The study recommends strengthening the influence of independent directors on the board to mitigate the influence of powerful CEOs.

Abstract The present paper describes the implicit fractional pantograph differential equation in the context of generalized fractional derivative and anti-periodic conditions. We formulated the Green’s function of the proposed problems. With the aid of a Green’s function, we obtain an analogous integral equation of the proposed problems and demonstrate the existence and uniqueness of solutions using the techniques of the Schaefer and Banach fixed point theorems. Besides, some special cases that show the proposed problems extend the current ones in the literature are presented. Finally, two examples were given as an application to illustrate the results obtained.

Floating Production Storage and Offloading (FPSO) platforms are the most used floating structures in the offshore oil and gas industry. They are generally kept in place with the aid of mooring lines anchored to the seabed. In deep waters, the responses of mooring lines become more significant and difficult to be accurately captured through experiments or numerical quasi-static models. Thus, this paper assesses the influence of water depth, mooring line diameter as well as added inertia and drag coefficients on the behaviour of a deepwater turret-moored FPSO platform. The commercial software, AQWA, is used to conduct fully coupled time-domain dynamic analysis for the FPSO subjected to a unidirectional random wave. The results highlighted the influence of water depths and mooring line diameter in reducing surge motions and increasing mooring line tensions, at the same time furnishes valid information on the fluctuation trend of these responses. Drag and inertia coefficients were found to have little impact on the dynamic motions of FPSO.

Abstract This study investigates the solutions of an impulsive fractional differential equation incorporated with a pantograph. This work extends and improves some results of the impulsive fractional differential equation. A differential equation of an impulsive fractional pantograph with a more general anti-periodic boundary condition is proposed. By employing the well-known fixed point theorems of Banach and Krasnoselskii, the existence and uniqueness of the solution of the proposed problem are established. Furthermore, two examples are presented to support our theoretical analysis.

Abstract One of the control measures available that are believed to be the most reliable methods of curbing the spread of coronavirus at the moment if they were to be successfully applied is lockdown. In this paper a mathematical model of fractional order is constructed to study the significance of the lockdown in mitigating the virus spread. The model consists of a system of five nonlinear fractional-order differential equations in the Caputo sense. In addition, existence and uniqueness of solutions for the fractional-order coronavirus model under lockdown are examined via the well-known Schauder and Banach fixed theorems technique, and stability analysis in the context of Ulam–Hyers and generalized Ulam–Hyers criteria is discussed. The well-known and effective numerical scheme called fractional Euler method has been employed to analyze the approximate solution and dynamical behavior of the model under consideration. It is worth noting that, unlike many studies recently conducted, dimensional consistency has been taken into account during the fractionalization process of the classical model.

Abstract Motivated by the Hilfer and the Hilfer–Katugampola fractional derivative, we introduce in this paper a new Hilfer generalized proportional fractional derivative, which unifies the Riemann–Liouville and Caputo generalized proportional fractional derivative. Some important properties of the proposed derivative are presented. Based on the proposed derivative, we consider a nonlinear fractional differential equation with nonlocal initial condition and show that this equation is equivalent to the Volterra integral equation. In addition, the existence and uniqueness of solutions are proven using fixed point theorems. Furthermore, we offer two examples to clarify the results.

Abstract In this research, we present the stability analysis of a fractional differential equation of a generalized Liouville–Caputo-type (Katugampola) via the Hilfer fractional derivative with a nonlocal integral boundary condition. Besides, we derive the relation between the proposed problem and the Volterra integral equation. Using the concepts of Banach and Krasnoselskii’s fixed point theorems, we investigate the existence and uniqueness of solutions to the proposed problem. Finally, we present two examples to clarify the abstract result.

Introduction Access to sanitation facilities (toilets or latrines) greatly improves human health. Low community sanitation coverage may lead to increased exposure to pathogens for households both with and without a sanitation facility.Methods We created a retrospective cohort using Demographic and Health Surveys from 1990 through 2018. Using regression with matched women as a random intercept, we assessed the association between community-level sanitation coverage and neonatal mortality (Poisson model, n=1 254 862 live births, 187 datasets), small birth size (logit model, n=1 058 843 live births, 187 datasets) and anaemia (logit model, n=1 304 626 women, 75 datasets).Results Among women with household sanitation, the incidence of neonatal death (incidence rate ratio: 0.85, 95% CI 0.77 to 0.93), the odds of small birth size (OR: 0.81, 95% CI 0.76 to 0.87) and anaemia (OR: 0.82, 95% CI 0.79 to 0.85) were lower for women in communities with 100% sanitation coverage compared with 1%–30% (p≤0.001 for all). There was no difference in neonatal deaths between women in communities with 31%–99% sanitation coverage compared with 1%–30% (p≥0.05). Among women without household sanitation, there were no differences in neonatal mortality by community sanitation (p≥0.05). The odds of small birth size were decreased (OR: 0.91, 95% CI 0.87 to 0.97, p=0.003) for women in communities with 61%–99% sanitation coverage compared with 1%–30%; there was no association with the other community sanitation categories (p≥0.05). The odds of anaemia were increased (OR: 1.08, 95% CI 1.06 to 1.11, p

For over three (3) decades, there has been an increase in research on energy sources from the production of oil using flexible marine risers, such as marine hoses. Marine hoses are conduits for special use as rubberized structures with hybrid polymer composites for offshore platforms in the oil and gas industry. This scientometric study uses qualitative, quantitative, and computational approaches. Data were retrieved using a research methodology that was created for this study using the SCOPUS and Web of Science (WoS) databases. This study provides a bibliometric literature review on marine hoses with an emphasis on the advancements made in the field from recent developments, geographical activity by countries, authorship histories, partnerships, funding sources, affiliations, co-occurrences, and potential research areas. The study found that the USA had the most publications, but there were fewer co-occurrences with connections outside the cluster. Due to the difficulty of adaptation, acceptability, qualification, and deployment of marine hoses in the offshore marine industry, this topic contains more conference papers than journal papers. Therefore, more funding sources and collaborations on marine hoses are required to advance the research. This study makes a contribution to scholarship on advances made in petroleum exploration and production for (un)loading hoses.

Recent activities in the oil and gas industry have shown an increasing need for monitoring engagements, such as in shipping, logistics, exploration, drilling, or production. Hence, there is a need to have asset management of these offshore assets (or facilities). Much of the offshore infrastructure is currently approaching or past its operational life expectancy. The study presents an overview on asset management of offshore facilities towards monitoring, safe practices, maintenance, and sustainability. This study outlines the major considerations and the steps to take when evaluating asset life extensions for an aging offshore structure (or asset). The design and construction of offshore structures require some materials that are used to make the structural units, such as offshore platform rigs, ships, and boats. Maintaining existing assets in the field and developing new platforms that are capable of extracting future oil and gas resources are the two key issues facing the offshore sector. This paper also discusses fault diagnosis using sensors in the offshore facilities. The ocean environment is constantly corrosive, and the production activities demand extremely high levels of safety and reliability. Due to the limited space and remote location of most offshore operations, producing cost-effective, efficient, and long-lasting equipment necessitates a high level of competence. This paper presents the guidelines on asset monitoring, sustainable maintenance, and safety practices for offshore structures. In this study, the management of offshore structures were also presented with some discussions on fault monitoring using sensors. It also proposes sustainable asset management approaches as guidelines that are advised, with policy implications.

Diverse forms of offshore oil and gas structures are utilized for a wide range of purposes and in varying water depths. They are designed for unique environments and water depths around the world. The applications of these offshore structures require different activities for proper equipment selection, design of platform types, and drilling/production methods. This paper will provide a general overview of these operations as well as the platform classifications. In this paper, a comprehensive review is conducted on different offshore petroleum structures. This study examines the fundamentals of all types of offshore structures (fixed and floating), as well as the applications of these concepts for oil exploration and production. The study also presents various design parameters for state-of-the-art offshore platforms and achievements made in the industry. Finally, suitable types of offshore platforms for various water depths are offered for long-term operations. An extension of this study (Part II) covers sustainable design approaches and project management on these structures; this review helps designers in understanding existing offshore structures, and their uniqueness. Hence, the review also serves as a reference data source for designing new offshore platforms and related structures.

The study examined the impact of foreign capital inflow on manufacturing sector growth in Nigeria using time series data from 1986 to 2019. The study specifically sought to examine the causal relationship between foreign capital inflows and the growth of the manufacturing sector in Nigeria in the long run The study employed the Autoregressive Distributed Lag (ARDL) estimation technique to account for the impact of foreign capital inflows on the manufacturing sector growth in Nigeria. The study utilized the Contribution of Manufacturing Sector to Gross Domestic Product (MGDP) as proxy for manufacturing sector growth. Manufacturing sector growth was the dependent variable while foreign direct investment (FDI), foreign portfolio investment (FPI) and foreign Aid (FOA) were the independent variables, and were regarded as proxies for foreign capital inflows. The study results revealed that foreign capital inflows through the FDI had a significant positive impact on contributions of the manufacturing sector to gross domestic product (GDP). The study also revealed that foreign capital inflows through the FPI had a significant positive impact on contributions of the manufacturing sector to the GDP. The study further revealed that foreign capital inflows through the FOA had a significant positive impact on contributions of the manufacturing sector to the GDP. Based on these findings, the study has recommended that the Nigerian government should promote foreign capital inflows through the FDI in order to achieve the desired level of manufacturing sector growth in the country’s economy in the long run. The government should also encourage foreign capital inflows through the FPI in order to attain the desired level of manufacturing sector growth in the Nigerian economy. Finally, the government should also support foreign capital inflows through the FOA in order to attain the desired level of manufacturing sector growth in the Nigerian economy in the long run.

An evidence for Crimean-Congo hemorrhagic fever virus (CCHFV) was found in Hyalomma impeltatum ticks collected from sheep in North Kordofan in the Sudan. Based on sequencing of the partial segment S, the detected virus belongs to lineage I with closest similarity to CCHFV strains from Senegal. So far, this lineage is unknown in the Sudan. Keywords: Hyalomma ticks, Crimean-Congo hemorrhagic fever virus, Sheep, Sudan

Offshore structures exist in a variety of forms, and they are used for a variety of functions in varied sea depths. These structures are tailored for certain environments and sea depths. Different actions for suitable equipment selection, platform type design, and drilling/production processes are required for the applications of these offshore structures, as given in Part I. This paper is the second part, which outlines various processes, loads, design approaches and project management of offshore platforms. To achieve these, proper planning must be conducted for lifting, transportation, installation, design, fabrication, and commissioning of these offshore platforms. Some historical developments of some offshore structures are presented, and some project planning routines are undertaken in this research. The ultimate goal is to provide a general overview of the many processes of offshore platform design, construction, loadout, transportation, and installation. Some discussions on the design parameters such as water depth and environmental conditions were presented. It also lists various software programs used in engineering designs covering software programs for structural analysis, 3D rendering, computer-aided design (CAD), hydrodynamic design, oceanic flow analysis, offshore structures analysis, mathematical modelling, coding/algorithm development software, and programming software to aid analytical calculations. The review also includes information on cutting-edge offshore platforms and industry advancements. Ultimately, for long-term operations, various types of offshore platforms for specific seawater depths are available.

The increasing energy demand has led to more explorations in the oil and gas industry. To achieve this, marine risers and pipelines are used to convey fluid and other resources to meet the increasing demand. In recent years, hybrid flexible composite risers have become more adaptable. Flexible risers have already proven to be a popular riser solution for various floating production systems in shallow to deepwater in many parts of the world due to their good dynamic behaviour and dependability. The hybrid flexible composite riser is made up of numerous layers of plastics, flexible pipes, composites, and steel. Some innovative monitoring methods, such as Fiber Optics Bragg Gratings (FBG), are based on a clamped composite structure with embedded optical fibre. This study presents characteristics of the monitoring techniques of composite flexible riser technology. The advantages of the monitoring techniques include aiding composite riser measurements, recording data from riser deformation, improving integrity assurance, and dependability of design from stable readings. It also proposes some design approaches as guidelines that are advised, with some policy implications.

The research work in this paper attempts to describe the outbreak of Coronavirus Disease 2019 (COVID-19) with the help of a mathematical model using both the Ordinary Differential Equation (ODE) and Fractional Differential Equation. The spread of the disease has been on the increase across the globe for some time with no end in sight. The research used the data of COVID-19 cases in Nigeria for the numerical simulation which has been fitted to the model. We brought in the consideration of both asymptomatic and symptomatic infected individuals with the fact that an exposed individual is either sent to quarantine first or move to one of the infected classes with the possibility that susceptible individual can also move to quarantined class directly. It was found that the proposed model has two equilibrium points; the disease-free equilibrium point (DFE) and the endemic equilibrium point (E1). Stability analysis of the equilibrium points shows (E0) is locally asymptotically stable whenever the basic reproduction number, R01. Sensitivity analysis of the parameters in the R0 was conducted and the profile of each state variable was also depicted using the fitted values of the parameters showing the spread of the disease. The most sensitive parameters in the R0 are the contact rate between susceptible individuals and the rate of transfer of individuals from exposed class to symptomatically infected class. Moreover, the basic reproduction number for the data is calculated as R0≈1.7031. Existence and uniqueness of solution established via the technique of fixed point theorem. Also, using the least square curve fitting method together with the fminsearch function in the MATLAB optimization toolbox, we obtain the best values for some of the unknown biological parameters involved in the proposed model. Furthermore, we solved the fractional model numerically using the Atangana-Toufik numerical scheme and presenting different forms of graphical results that can be useful in minimizing the infection.

Following the rising technological advancements on composite marine structures, there is a corresponding surge in the demand for its deployment as ocean engineering applications. The push for exploration activities in deep waters necessitates the need for composite marine structures to reduce structural payload and lessen weights/loads on platform decks. This gain is achieved by its high strength–stiffness modulus and light-in-weight attributes, enabling easier marine/offshore operations. Thus, the development of composite marine risers considers critical composite characteristics to optimize marine risers’ design. Hence, an in-depth study on composite production risers (CPR) is quite pertinent in applying composite materials to deep water applications. Two riser sections of 3 m and 5 m were investigated under a 2030 m water depth environment to minimise structural weight. ANSYS Composites ACP was utilized for the CPR’s finite element model (FEM) under different load conditions. The choice of the material, the fibre orientation, and the lay-up configurations utilised in the modelling technique have been reported. In addition, the behaviour of the composite risers’ layers under four loadings has been investigated under marine conditions. Recommendations were made for the composite tubular structure. Results on stresses and weight savings were obtained from different composite riser configurations. The recommended composite riser design that showed the best performance is AS4/PEEK utilising PEEK liner, however more work is suggested using global design loadings on the CPR.

The behavior of different mooring line materials has a significant influence on the behavior of the mooring system and, consequently, the dynamic responses of the floating platform. Although there have been previous studies on FPSOs and their mooring systems, the influence of mooring line failure scenarios associated with different mooring materials has received less attention, particularly for turret-moored FPSOs with taut moorings. Thus, this paper investigates the behavior of different mooring line materials in intact, single-line, and double-line damaged conditions on the hydrodynamic responses of the FPSO, restoring behavior, mooring, and riser tensions considering wave conditions in the Gulf of Mexico. Mooring lines including Aramid, HMPE, polyester, and steel wire were considered in the middle segment, which was the segment of interest in this study. The restoring forces of the mooring system were found to increase with increasing mooring stiffness, and a higher stiffness resulted in a higher loss of restoring force in the case of single-line failure. In all cases, the submerged weight and material stiffness had a significant influence on dynamic responses, mooring tension, transient responses, riser tension, and especially on the ability of the mooring system to resist the case of single-line failure. Each material was observed to behave differently in each degree of freedom (DOF), showing the necessity to pay close attention to the selection of mooring material for specific objectives.

In recent times, the utilisation of marine composites in tubular structures has grown in popularity. These applications include composite risers and related SURF (subsea umbilicals, risers and flowlines) units. The composite industry has evolved in the development of advanced composites, such as thermoplastic composite pipes (TCP) and hybrid composite structures. However, there are gaps in the understanding of its performance in composite risers, hence the need for this review on the design, hydrodynamics and mechanics of composite risers. The review covers both the structure of the composite production riser (CPR) and its end-fittings for offshore marine applications. It also reviews the mechanical behaviour of composite risers, their microstructure and strength/stress profiles. In principle, designers now have a greater grasp of composite materials. It was concluded that composites differ from standard materials such as steel. Basically, composites have weight savings and a comparative stiffness-to-strength ratio, which are advantageous in marine composites. Also, the offshore sector has grown in response to newer innovations in composite structures such as composite risers, thereby providing new cost-effective techniques. This comprehensive review shows the necessity of optimising existing designs of composite risers. Conclusions drawn portray issues facing composite riser research. Recommendations were made to encourage composite riser developments, including elaboration of necessary standards and specifications.

This article focuses on the idea of multiculturalism in Javanese mythical believing (Kejawen) communities within the paradigm of Qur'anic studies. The discussion of the research emphasizes the axiological shift of QS. Al-Kafirun (109) in the milieu of Urip Sejati community of Yogyakarta, Indonesia. “Urip Sejati” is a Javanese religious society that has developed as a minority group because it is domiciled near to various centers of Islamic civilization as pesantren, historic mosques, and colleges in Krapyak. This research has been held since 2018 by doing literary studies, observations, and interviews through the leaders of Urip Sejati community. The structure of this article features a complex process of analysis on transmission and transformation of Qur'anic interpretations in the paradigm of sociology. It also analyzes the patterns of the phenomenon in a synchronic and diachronic paradigm to get through a worldview reading. On its formal form, the reception of Q.109: 6 in the membership of Urip Sejati contains informative and performative suppositions. This verse became a major foundation for the construction of multiculturalism because it contains the doctrine acknowledged as a verse that supports pluralities.

Tubular pipe structures have been used in various applications—domestic, aviation, marine, manufacturing and material testing. The applications of tubular pipes have been considered greatly in the installation of tubular pipes, marine risers and pipe bending. For the investigation of plastic strains and the mechanical behaviour of a tube under bending, considerations were made utilising an exponent model with assumptions on the plane strain. The bending moment, wall thickness effect, cross-sectional distribution, stresses during bending and neutral layer boundaries were all presented as necessary theoretical formulations on the physics of tubular pipe bending. This model was based on the analytical and numerical investigation. In principle, the application can be observed as the spooling of pipes, bending of pipes and reeling. Comparisons were made on two models developed on the finite element analysis in Simscale OpenFEA, namely the linear-elastic and the elasto-plastic models. This study presents visualization profiles using plastic strain to assess its effect on the tubular pipes. This can increase due to the limitation of plastic deformation on the composite materials selected.