bluuebunny/crossref_metadata_2025 huggingface dataset:
Microbial-Induced Calcite Precipitation Study on the Plasticity and Compaction Characteristics of Lateritic Soil Treated with Bacillus Megaterium in Urea-CaCl2 Culture Medium
Authors: Osinubi K J , Eberemu A O , Ijimdiya T S , Etim R K
Published: March 2021

An ecofriendly method of soil improvement known as Microbial Induced Calcite Precipitation (MICP) has received significant recognition in the past decade. This study presents a report on the capability of MICP in modifying the plasticity and compaction properties of lateritic soil bio-treated with different suspension densities of a ureolytic microorganisms - Bacillus megaterium (B. megaterium). Specimens were prepared with liquid limit moisture of the natural soil in three mix ratios of B. megaterium (B) and cementation reagent (C) (urea medium): 25 % B: 75 % C, 50 % B: 50 % C and 75 % B: 25 % C. Another set of specimens were prepared at optimum moisture content (OMC) equivalent covering 1/3 pore volume of B. megaterium and 2/3 pore volume of urea medium introduced in three sequences at 6-hour interval to steadily initiate MICP mechanisms. The results of the various mix ratios indicated improvement in plasticity index (PI) with higher B. megaterium suspension density. The best improved PI value was obtained for specimen treated with 75 % B: 25 % C mix ratio at B. megaterium suspension density of 2.40 × 109 cells/ml with an equivalent maximum 5.3 % CaCO3 content. The maximum dry density (MDD) and OMC values marginally increased with higher B. megaterium suspension density as well as calcite content. The micrographs obtained from scan electron microscope (SEM) showed changes from untreated to bio-treated state, which resulted in non-uniform precipitation of calcite in the soil. The variation in elemental quantifications displayed by the X-ray energy dispersive spectroscopy (EDS) validate the formation of calcite within voids and on surface of the soil particles.
Effect of curing method on unconfined compressive strength of silty sand treated with Bacillus Megaterium
Authors: Eberemu A O , Onah M , Osinubi K J
Published: March 2021

Laboratory tests were carried out to evaluate the effect of curing method on the unconfined compressive strength (UCS) of silty sand treated with Bacillus megaterium. (B. megaterium) using the Microbial Induced Calcite Precipitation (MICP) technique. Compaction test was conducted using the British Standard light (BSL) energy. UCS tests were performed on two sets of specimens treated with varying B. megaterium suspension densities and cementation reagent using trial mix ratio of 50% B. megaterium (B) and 50 % cementation reagent (C) (i.e., 50B-50C) for the treated specimen and 100 % cementation reagent (C) (i.e., 100C) for the control specimen. One set of specimens extruded from compaction mould was air-cured at room temperature for 24 hours, while the second set of specimens were placed in sealed polythene bags immediately after extrusion from the moulds. The results obtained show that the peak UCS values of the air-cured specimens and the sealed specimens are 448.8 kN/m2 and 19.8 kN/m2, respectively, for treatment with B. megaterium suspension density of 6.0 x 108 cells/ml. The study shows that the UCS of silty sand treated with B. megaterium is sensitive to curing method.
Performance evaluation of asphalt concrete mixture incorporating calcite powder as filler substitute for sustainable pavement construction
Authors: Modupe A E , Aladegboye O J , Alejolowo E A , Orogbade B O , Akade G O , Akinmolayan O P
Published: March 2021

The increasing cost and paucity of conventional pavement construction materials has in recent times become very worrisome and a serious challenge in the road construction industry. This has spurred the search for a less expensive and environmentally friendly material, readily available and suitable for the purpose of constructing sustainable pavements both in the rural and urban areas of developing countries. In this research, the suitability of calcite powder in asphalt as filler in substituted proportions was investigated through tests on the modified samples for enhanced engineering properties. This was achieved by partially replacing conventional filler with calcite in proportion of “10%, 20%, 30%, 40% and 50%” respectively. After the production of the modified bituminous concrete at the various proportions, the samples produced were placed in a water bath for 30 minutes at a temperature of 60°C before conducting the Marshall stability test and flow. Marshall stability values of 37.7 kN, 37.9 kN, 34.0 kN, 35.0 kN, 28.9 kN and corresponding flow values of 12.0 mm, 11.3 mm, 10.5 mm, 9.60 mm, 10.3 mm, were obtained for the modification proportions respectively. The stability values were observed to be higher than the control mix and likewise satisfy the minimum requirement of 3.33 kN or 340 kg according to the Marshal mix design specification for wearing course surfacing. Similarly, the flow values obtained where found to be within the specified range of 8 – 17 mm at 0.25mm units. Percentage air voids (Vv) values of 3.7%, 5.2%, 4.7%, 3.0%, and 5.9% obtained where also found to satisfy the required range of 3-5% according to the specification. Voids filled with bitumen (VFB) values of 78.58%, 69.56%, 69.73%, 76.63%, and 58.93% derived where also within specified range 75 – 85 % of the specification. The X-Ray diffraction (XRD) micrograph showed the distinct presence of calcium and oxygen in the hot mix asphalt modified with calcite, while the scanning electron microscope (SEM) provided an in-depth perspective of the concrete grains in the hot mix matrix and the improved bonding of the aggregates, bitumen and calcite due the presence of calcium. The results have shown the possibility of calcite utilization in bituminous mixes, towards reducing cost of construction and best suitable for medium trafficked roads, parking lots and walkways.
Investigation of geotechnical properties of soil samples in Isu-Njaba Imo State
Authors: Ekeleme A C , Ibearugbulem O H , Ugwu E I , Njoku C E , Amanamba E C , Ibe O P , Igwegbe E W , Okpara P C
Published: March 2021

The properties of the geotechnical characteristics of soil samples from Isu-Njaba borrow pit was carried out in this study. Ten soil samples from the depth of 3m were taken from the pit at day1, day7 and day14 respectively. The tests carried out on the soil samples include sieve analysis, natural moisture content, Atterberg limit, compaction and California bearing ratio tests in line with standards. From the results, the fine soil content is 4.19%, and the soil samples contain more of sand and gravel and are uniformly graded. Thus the soil is classified as A-2-4 soil in line with AASHTO standard of soil classification. The obtained liquid limit is 38.02%, plastic limit of 27.53% and plasticity index of 10.49%. The results from the test on compaction showed the maximum dry density to be 1.56 Mg/m and optimum moisture content as 14.30%. The values of the California bearing ratio for the non-soaked soil is 20.64%, and 12.63% for the soaked soil. The study showed that the soil samples from Isu-Njaba borrow-pit could be applied as materials for sub grade, sub base and base purposes, as most of the properties meet the specifications of the Federal Ministry of Works and Housing guidelines for road construction.
Suitability of using borrow pit soils collected from Southwestern Nigeria as landfill liners
Authors: Akinwumi I I , Afolayan O D , Okeke C A U , Badiru O O , Jolayemi K J
Published: March 2021

Effective waste disposal system is essential in preventing the infiltration of leachate into the groundwater and in achieving the sustainable development goal of ensuring clean water. One of the ways to provide an adequate disposal system is through the provision and use of engineered landfills for waste containment instead of open dumps. Consequently, this study evaluates the suitability of using soils from six borrow pits collected from six states in Southwestern, Nigeria. To assess the suitability of the soils, laboratory tests were carried out to determine the index properties, mechanical and hydraulic properties of the collected soil samples. The results showed that the soil samples collected from the selected borrow pits in Ogun, Oyo and Ekiti States could be effectively employed for the containment of inert waste. In contrast, the soil samples collected from the selected borrow pits in Osun, Lagos and Ondo States needs to be improved such that their unconfined compressive strengths satisfy the standard requirement (≥200 kN/m2). This study provides readily accessible soil data for use by engineering professionals involved in selecting suitable soil for use as landfill liners in Southwestern, Nigeri.
Influence of GIS on sustainable pavement maintenance: a comparative review
Authors: Ngene B U , Bassey D E , Busari A A , Bamigboye G O , Nworgu A T
Published: March 2021

Road transportation remains dominant in passenger and freight movements across Africa. Yet, a majority of the countries in Africa do not perform proactively in ensuring the sustainability of highway infrastructure. This research reviews recent literature in recognizing the state-of-the-practice on the application of GIS-based techniques in sustainable pavement maintenance, hence promoting a systematic approach for highway maintenance management. Furthermore, it compares contemporary maintenance practices in the five major African regions to highlight the differences and similarities. Most countries have since implemented institutional reforms such as the provision of road funds and agencies, thereby making substantial improvements on road maintenance. However, several challenges, including inadequate financing, lack of technical expertise, poor administration, and lack of continuous research and development still hinder sustainable road maintenance in Africa. Hence, most African countries still depend solely on budget financing while adopting delayed and reactive approaches to highway maintenance activities. The study revealed that sustainable methods of pavement maintenance have neither been incorporated in policy nor practices involving highway pavement management in most African nations. And as such, it encourages respective road agencies to integrate GIS-based techniques into road maintenance management at all functional levels to promote sustainability.
Effect of iron ore tailings on the plasticity and compaction properties of selected tropical soils
Authors: Yohanna P , Sani R O , Ishola K , Ijimdiya T S , Eberemu A O , Osinubi K J
Published: March 2021

The workability of any soil, when used as a construction material, is greatly affected by its plasticity and compaction characteristics. This research investigates the effect of iron ore tailings (IOT) on the plasticity and compaction properties of lateritic soil (LTS) and black cotton soil (BCS). Atterberg limit and compaction test using three energies, British standard Light, BSL, British standard Heavy, BSH, and West Africa standard, WAS were carried out. These tests were conducted on mixed ratios of 0, 2, 4, 6, 8, and 10 % of IOT mixed each with LTS and BCS separately. A Statistical conceptual model was developed using Minitab R15 to predict the values of the maximum dry density (MDD) and optimum moisture content (OMC) from the computed laboratory results. Analysis was then carried out on the predicted results using origin pro version 8 to test the efficacy of results obtained. The result of specific gravity test shows increase with IOT concentration. An improvement on the plasticity of the modified soil was noted. The liquid limit for both LTS and BCS decreased with increasing IOT concentration. Values drop from 43.4 to 42.7% for LTS and 56 to 52.6% for BCS at 0 and 10% of IOT content, respectively. Plastic limit increased with increasing IOT concentration for LTS and decreased for BCS. In the case of the Plasticity index, values decreased for LTS and marginally increased for BCS treated with IOT. MDD values increased and thereafter drop for LTS treated with IOT while for BCS values increased from natural up to 10% IOT content. OMC values increased for LTS treated with IOT and decreased for BCS treated with IOT. The effectiveness of the developed model was validated using the values of the correlation coefficient obtained from the statistical analysis, which showed a solid relationship between predicted and measured values. Plasticity index values obtained for IOT stabilized BCS did not meet up to the standard requirement when used as a sub-base and base course material respectively. However, the treatment of LTS and BCS with 8-10% IOT improved the soil properties and can be used for pedestrian walkways.
Fresh Characteristics of High-Performance Self-Compacting Concrete using Induction Furnace Slag as Supplementary Cementitious Material
Authors: Mark O G , Ede A N , Arum C , Jolayemi K J , Ojuawo I , Ajimalofin D , Adediran J , Babatunde I , Olimaro G B
Published: March 2021

Using wastes products in concrete contributes towards sustainability in civil engineering construction. Producing high-performance-self-compacting concrete (HPSCC), using induction furnace slag (IFS) contributes positively to the sustainability of concrete technology. Many researchers have developed self-compacting concrete (SCC), but there are minimal investigations reported considering the high-performance in the development of SCC. The aim of this paper is to determine the fresh characteristics of HPSCC, using IFS as a supplementary cementitious material. Tests were conducted on filling ability, passing ability, as well as resistance to segregation of the fresh HPSCCs, containing IFS at percentage replacement of 0%, 10%, 20%, 30%, 40% and 50%. Slump flow and T50cm slump flow tests were conducted to determine the filling ability. L-Box test was used to determine the passing ability. V-funnel at T5minutes test was conducted to determine the resistance to segregation. The results showed that the slump flow ranged between 652 and 687 mm, the T50cm slump flow ranged between 2.59 and 3.97 seconds, the L-box value ranged between 0.81 and 0.95, while V-funnel at T5minutes ranged between 1.88 and 3.11. The fresh properties criteria, according to EFNARC were fulfilled, except for few concretes with IFS content greater than 20%. It is therefore recommended that induction furnace slag be incorporated as a supplementary cementitious material (SCM) when producing HPSCC.
Review of the mechanical and durability properties of natural fibre laminate-strengthened reinforced concrete beams
Authors: Ede A N , Ben-Ejeagwu B , Akpabot A I , Oyebisi S O , Olofinnade O M , Mark O G
Published: March 2021

The brittle nature of concrete has always necessitated the need for various forms of reinforcement that will absorb the tensile stress that is responsible for cracking. Conventionally, steel rebar embedded in concrete, giving rise to reinforced concrete structures has turned out to be a composite material that has been most used for infrastructural development around the world. The ductility impacted on concrete by steel rebar has been very efficient, though reinforced concrete structures are prone to durability challenges when exposed to adverse environmental conditions. Most times, repairing deficient concrete structures is more economical and sustainable than total replacement. Various approaches have been successfully implemented around the world in strengthening weakening reinforced concrete structures, nevertheless, bonding of fiber reinforced polymer (FRP) composites to the soffit of weak beams is turning out to be a viable option. Of particular interest is the adoption of naturally occurring fibers for laminates used for beam strengthening. In this era of Sustainable Development Goals (SDGs), in which the world is striving to reduce the effects industrial productions on the environment, advances in adopting renewable materials is highly welcomed. This research reviews the past works on the use of natural fibre-based composites in strengthening deficient reinforced concrete beams. The outcome of this research will go a long way in contributing towards the achievement of the SDGs.
Suitability of using post-consumer polyethylene terephthalate wastes in cement-based hollow sandcrete blocks
Authors: Davies I E E , Olofinnade O M
Published: March 2021

In recent times, efforts are channeled towards limiting the impact of waste plastic pollution on the environment. This study examines the beneficial utilization of polyethylene terephthalate (PET) wastes, which is a non-biodegradable waste materials as a partial substitute for sand in the production of non-load bearing hollow sandcrete blocks. The physical and mechanical properties such as density and compressive strength of the hollow sandcrete blocks using PET waste as a replacement for fine aggregate at 5%, 10%, 30% and 50% were determined. Tests results show that the density of the produced sandcrete blocks decreases as the waste PET content increases. Results showed that the density varied from 1391.33 kg/m3 for 50%PET content to 1954.54 kg/m3 for 5%PET content, while the density of the reference sandcrete was 2002.15 kg/m3 for 7 days. The values of densities ranged between 1453.88 kg/m3 for PET 50% and 1851.09 kg/m3 for PET 5% and the density of reference sandcrete was 1991.77 kg/m3 at 28 days. The sandcrete blocks also demonstrate a similar reduction trend in compressive strength as the PET content increases. The compressive strength ranged between 1.140 N/mm2 for 50%PET and 2.564 N/mm2 for 5%PET content and 1.510 N/mm2 for 50%PET to 2.991 N/mm2 for 5%PET respectively, as the curing age increases from 7 to 28 days. The hollow sandcrete block containing an optimum 5% replacement percentage of sand with PET waste showed comparable strength to the conventional sandcrete blocks. This will help to mitigate the menace of marine plastic pollution and promote responsible consumption.
Strength Evaluation of Aluminium Fibre Reinforced Particle Board made from Sawdust and Waste Glass
Authors: Atoyebi O D , Ajamu S O , Odeyemi S O , Ojo D J , Ramonu J A L
Published: March 2021

This research investigated the effects of aluminium shavings on particleboards produced from sawdust and waste glass using Urea formaldehyde as binder. Twelve (12) boards were produced and each had different variations of sawdust, waste glass and aluminium shavings with a constant volume of adhesive used. The boards were tested for physical properties such as density, Thickness swelling (TS) and Water absorption (WA) and mechanical properties such as modulus of rupture (MOR) and modulus of elasticity (MOE). The effects of the aluminium shavings on the boards were observed in the MOR and MOE values such that these values for board A1 were 3.30 N/mm2 and 10.45 N/mm2 for 20% aluminium shavings content but reduced to 3.16 N/mm2 and 8.97 N/mm2 respectively for board A2 with 10% aluminium shavings content. This trait was observed in other boards with the same content except in boards B1 and B2 where the MOR and MOE values increased with the values for B1 being 2.06 N/mm2 and 6.98 N/mm2 and 2.91 N/mm2 and 10.17 N/mm2 respectively. The values for density of the boards increased as the sawdust decreased and also as the glass content increased. The boards with the highest values for thickness swelling and water absorption were the first three as they possess the highest quantity of sawdust. From the results, none of the boards produced met up to the requirements for use for structural purposes, board B3 possesses the highest MOR value while board D3 possesses the highest MOE value. Therefore, the boards can serve non-structural purposes such as partitions and indoor uses.
Electrochemical control of high carbon steel corrosion using rosemary oil in citric acid medium
Authors: Odunlami O A , Abatan O G , Busari A A , Alao G T , Loto R T , Olomukoro O T
Published: March 2021

The Inhibition efficiency of Rosemary oil (Rosmarinus officinalis) for corrosion control of high carbon steel was done in citric acid medium by weight loss method. The Rosmarinus officinalis was administered in the proportion of 0%, 0.50%, 1.00%, 1.50%, 2.00% and 2.50% concentration. This study unveiled that the inhibition efficiency performed excellently with maximum percentage of 88.3% at room temperature in 0.5M citric acid solution. This has shown the effectiveness of Rosmarinus officinalis inhibitor in corrosion analysis of high carbon steel.
Prediction of a singly reinforced concrete beam steel using artificial neural network
Authors: Olawale S O A , Akintunde O P , Afolabi M O , Agbede O A
Published: March 2021

This paper presents the prediction of a singly reinforced concrete beam using Artificial Neural Networks (ANN). The method was adopted for cost optimization of the structural element and compared with the requirements of Eurocode 2 design. The code provisions for the design of a singly reinforced beam can vary from place to place. The use of a system immune from the code variation is an excellent means of predicting the reinforcement’s need of a rectangular concrete beam. In this work, an artificial neural network (ANN) is employed to forecast the reinforcement of such a beam. Artificial neural network has the potential to simulate the data that are hard to produce in arithmetical analysis. The scheme was established using the MATLAB tool kit. The design variables were the depth of the beam, the width of the beam, and the moments. A forward pass supervised backward propagation training. The regression analysis of the results is one to one match. The predicted and target values are completely in accord.
Factors affecting sustainable infrastructure delivery in South Africa - a case of Gauteng province
Authors: Jacobs J , Aigbavboa C , Thwala W , Dithebe K
Published: March 2021

Infrastructure plays a crucial role in the economic growth and development of any country; therefore, it is important to ensure adequate investments for the delivery of infrastructure services. This paper assessed factors affecting the development of sustainable infrastructure in South Africa. The identified factors can be utilised by government as reference to enhance the delivery of sustainable infrastructure. To achieve the objective of the study, Quantitative data was collected. The study used a sample size of 57 out of the 65 questionnaires (a response rate of 87.7%) which were answered by professionals in the built environment viz. Architects, Property Developers, Quantity Surveyors, Engineers, Construction and Project Managers. The data collected was then analysed and interpreted using IBM Statistical Package for Social Science (SPSS) computer software to provide mean item scores, standard deviations and Cronbach’s alpha. Given the explored factors which affect the delivery of sustainable infrastructure, the results have established that due to developers habit of building to maximise profit only, not for end-users’ comfort and the initial high cost required to develop sustainable infrastructure were the major factors that affect the delivery of sustainable infrastructure. It is recommended that the government develop clear, stable and credible policies that will attract investors who will be committed to inject financial resources into infrastructure development and alter the existing building regulations to complement the sustainable development goals.
Examining the Potential Recovery of Compost from Mixed Fruit Wastes from a Campus Eatery Wastes
Authors: Olukanni D O , Ogedengbe V O , Ogundare O J
Published: March 2021

The burning and open dumping of wastes is a common practice in developing countries such as Nigeria. These practices are causes of environmental concern as they generate air pollutants, contaminate surface and underground water resources, and breed disease vectors, consequently affecting public health. Nevertheless, composting has been identified as a sustainable technique to efficiently manage and dispose these wastes while also recovering a marketable resource. This study was aimed at assessing the potential recovery of compost from mixed fruit wastes as a method of proper disposal. Fruit wastes generated within a university campus were mixed with dry leaves and manure and decomposed in a composting process for 6 weeks. The physico-chemical properties such as temperature, pH level, moisture content, and NPK value of the resulting compost were determined during and after the process. The experimental results indicated a temperature range of 25°C to 56°C and pH level ranging from 6.6 to 8.1 during the composting process. The moisture content of the compost pile was detected to gradually reduce from 56% to 40% during the experiment. The NPK ratio of the final compost product was evaluated to be 0.61:0.40:0.73. The compost produced in this study could be used for agricultural purposes to supply nutrients to growing plants and the soil.
Assessment of hydrogen sulfide emission levels on the floors of some selected bakeries in southwestern Nigeria
Authors: Odunlami O A , Abatan O G , Busari A A , Alao G T , Elehinafe F B , Emekekwue C O
Published: March 2021

The hydrogen sulfide (H S) emission and oxygen (O2) level was measured within four bakeries in Ota, Ogun State. This was done to know the effect of H2S on the people working in bakeries and those walking into bakeries for business purposes. The data obtained was analyzed and the H2S emission level was around the new recommendation for airborne of 1 ppm recommended for 8 hours by ACGIH (American Conference Governmental Industrial Hygenist [1]. The highest mean concentrations of H2S were; bakery 1 (0.4 ppm), bakery 2 (0.73 ppm), bakery 3 (1.0ppm), H2S emission was not detected by the gas analyzer in bakery 4. O2 level (20.8ppm) remained constant all through the study, which is the expected ambient O2 value, this is because of the cross ventilation within the bakeries. Though literatures have shown that ovens emit some harmful gases like CO, NOx, VOC and H2S, the concentrations of these gases can be reduced if there is cross ventilation within the bakery and exhaust stacks positioned high enough towards the roof, out of the building. The stack effect happens, when warm air moves or flow upwards in the building. The warm air rises because it is lighter than cold air, when it rises, it escapes out of the upper levels of the building through ventilation openings, windows or leakages. The rising warm air reduces the pressure at the base of the building, forcing cold air to infiltrate through either open doors, windows, or other openings and leakage in lower levels of the building. The H2S emission level was higher during the heating periods than the baking periods in all the bakeries considered due to the combustion process taking place during heating. The electrically fired ovens gave lower H2S concentrations than the wood fired ovens. To ensure safety for workers and consumers in Bakeries, regular inspection of bakeries should become a priority for the various agencies involved.
Rheological characteristics of metal oxide nanocomposite and its application in enhanced oil recovery
Authors: Sowunmi A , Efeovbokhan V E , Orodu O D , Azeta O
Published: March 2021

A nanocomposite is a mixture of a nanoparticle and a complementary substance. In crude oil recovery, it is most commonly the combination of a nanoparticle and a polymer. In enhanced oil recovery, metal oxide nanoparticles may be combined with polymers and injected into a reservoir after water flooding to achieve greater recovery of crude oil; however, current research in this area is limited. In this work, rheological properties and oil recovery potential of two nanocomposites: alumina/xanthan gum and alumina/guar gum; were investigated. The viscosity of different concentrations of the nanocomposites was measured using the Model 800 OFITE Viscometer, and core flooding experiment was done using a Reservoir Permeability Tester. For both nanocomposites, it was observed that their viscosities increased with increasing concentration of alumina nanoparticles and the effect was higher as polymer concentration was increased. For the core flooding experiments, the xanthan gum and alumina composite achieved total recovery of 72.8 % while the guar gum alumina nanocomposite achieved total recovery of 69.3 %. The use of alumina combinations of nanocomposite is, therefore, promising and should be explored further.
A review of the mineralogical and geotechnical properties of some residual soils in relation to the problems of road failures: A case study of Nigeria
Authors: Sani R O , Olofinnade O M , Akinwumi I I , Afolayan O D
Published: March 2021

Poor geotechnical and mineralogical properties of soils used for road construction are a significant factor responsible for pavement failures. This is because most soils encountered at failed portions of some pavements do not meet the specifications according to relevant standards. It is with this in mind that this study carried out a systemic review on some residual soils in Nigeria, with a focus on their locations, geotechnical, and mineralogical properties in comparison to standards specified in the Nigerian specification for road and bridges. This study also reviewed how these properties have contributed to various road failures in different regions of the country. It was observed that the geotechnical and mineralogical properties of most residual soils in some regions of Nigeria did not meet up with the standards stipulated by the Nigerian Specification for road materials. Reviews carried out on the place of geotechnical and mineralogical characteristics on various road failures in Nigeria showed that a high volume of research works was carried out in the south-western and southeastern parts of the country compared to the Northern region.
A review on the mechanical strength of aluminium - clay composites
Authors: Udoye N E , Fayomi O S I , Inegbenebor A O
Published: March 2021

The innovation in the usage of cheaper materials with better quality has been in the mind of many scientists. Recently, more requests have been on the utilization of agro-industrial product to produce materials to curb ecological hazards. Clay could be an alternative to SiC and Al2O3 due to their cheaper rate and availability. Reinforcements can be integrated into the melt using cheap and globally recognized stir casting method. Low - cost eco-friendly waste products that are easily accessible like clay, nanoclay, kaolinite, mica, and carbon are utilized as reinforcement in aluminium alloy. This review paper studied the various compositions of aluminium alloy composites for manufacturing purposes and its usage in automobile, aircraft, marine and the transportation industry. The study revealed that the addition of clay as reinforcement increases the properties of the composites.
Progresses on mild steel protection toward surface service performance in structural industrial: An Overview
Authors: Fayomi O S I , Olusanyan D , Ademuyiwa F T , Olarewaju G
Published: March 2021

Mild steel has been widely used in domestic and industrial applications due to its excellent properties. Their property in engineering application makes it one of the leading engineering materials with multifaceted usage. Despite this growing interest in manufacturing because of cost and durability, challenges arising from wear, corrosion and structural damages has been a concern and the need to search for continuous way-out become necessary. This overview provides concise progresses on mild steel toward active protection for service performance.
Development and construction of automatic three-phase power changeover control circuit with alarm
Authors: Abdulkareem A , Somefun T E , Oguntosin V , Ogunade F
Published: March 2021

One primary reason for Nigeria economic underdevelopment is the inconsistency of power supply, and as a result of this fact, immediate attention is required. The criticality of an uninterrupted power supply cannot be overemphasised. Therefore, is this work, a new approach is applied to switch power from a three-phase source to another without human interference. This work presents an automatic three (3) phase power changeover circuit with an alarm that turns power supply from Power Holding Company of Nigeria (PHCN) to a power generator at an instant of interruption or outage from PHCN. The signal is introduced to notify the user of the restoration of the PHCN supply and automatically carries out this process. This process is achieved by using logic control circuits, three-phase sequence monitors, phase(s) failure monitor, overload relay, and contacting relays for practical switching which takes approximate 30 seconds.
Characterisation of freeform, structured surfaces in T-spline spaces and its applications
Authors: Wang Jian , Zou Renqi , Colosimo Bianca Maria , Lu Wenlong , Xu Long , Jiang Xiangqian Jane
Published: March 2021

In advanced manufacturing, surface topographical designs with deterministic freeform and embedded structures have proven to contain effective, additive functionalities. These surfaces need to be geometrically characterised regarding the designed form and structures. However, this is problematic since existing characterisation techniques such as polynomial form removal, Gaussian/spline/wavelet filtration, field-based statistical parameterisation, spectral and fractal analysis do not provide satisfying results. In this paper, we, therefore, propose to characterise the complex surfaces in T-spline spaces, i.e. basis spline spaces along with T-junctions, using an efficient T-spline fitting algorithm. Several case studies show that the proposed method is compatible and has notable potentials for the challenging characterisation tasks, including non-Euclidean freeform removal, edge-reserving filtration with multiscale analysis, scattered data interpolation and smoothing, and smart large-data downsampling or compression.
Elmendorf constructions for 𝐺-categories and 𝐺-posets
Authors: Rubin Jonathan
Published: March 2021

We introduce new Elmendorf constructions for equivariant categories and posets, and we prove that they are compatible with the classical topological one. Our constructions are more concrete than their model-categorical counterparts, and they give rise to new proofs of the Elmendorf theorems for equivariant categories and posets.
Cega: a single particle segmentation algorithm to identify moving particles in a noisy system
Authors: Masucci Erin M. , Relich Peter K. , Ostap E. Michael , Holzbaur Erika L. F. , Lakadamyali Melike
Published: March 2021

We developed an approach, called Cega, to analyze the motility of kinesin motors translocating on microtubules in complex and noisy systems. Cega separates the fluorescent signatures of moving motors from background noise using the Kullback-Leibler divergence and produces coordinates of moving particles for downstream single particle tracking.
Secreted therapeutics: monitoring durability of microRNA-based gene therapies in the central nervous system
Authors: Sogorb-Gonzalez Marina , Vendrell-Tornero Carlos , Snapper Jolanda , Stam Anouk , Keskin Sonay , Miniarikova Jana , Spronck Elisabeth A , de Haan Martin , Nieuwland Rienk , Konstantinova Pavlina , van Deventer1 Sander J , Evers Melvin M , Vallès Astrid
Published: March 2021

The preclinical development of microRNA-based gene therapies for inherited neurodegenerative diseases is accompanied by translational challenges. Due to the inaccessibility of the brain to periodically evaluate therapy effects, accessible and reliable biomarkers indicative of dosing, durability and therapeutic efficacy in the central nervous system are very much needed. This is particularly important for viral vector-based gene therapies, in which a one-time administration results in long-term expression of active therapeutic molecules in the brain. Recently, extracellular vesicles have been identified as carriers of RNA species, including microRNAs, and proteins in all biological fluids, whilst becoming potential sources of biomarkers for diagnosis. In this study, we investigated the secretion and potential use of circulating miRNAs associated with extracellular vesicles as suitable sources to monitor the expression and durability of gene therapies in the brain. Neuronal cells derived from induced pluripotent stem cells were treated with adeno-associated viral vector serotype 5 carrying an engineered microRNA targeting huntingtin or ataxin3 gene sequences, the diseases-causing genes of Huntington disease and spinocerebellar ataxia type 3, respectively. After treatment, the secretion of mature engineered microRNA molecules was confirmed, with extracellular microRNA levels correlating with viral dose and cellular microRNA expression in neurons. We further investigated the detection of engineered microRNAs over time in the CSF of non-human primates after a single intrastriatal injection of adeno-associated viral vector serotype 5 carrying a huntingtin-targeting engineered microRNA. Quantifiable engineered microRNA levels enriched in extracellular vesicles were detected in the CSF up to two years after brain infusion. Altogether, these results confirm the long-term expression of adeno-associated viral vector serotype 5-delivered microRNAs and support the use of extracellular vesicle-associated microRNAs as novel translational pharmacokinetic markers in ongoing clinical trials of gene therapies for neurodegenerative diseases.
Minimizing treatment complexity of combat-related soft tissue injuries using a dedicated tension relief system and negative pressure therapy augmented by high-dose in situ antibiotic therapy and oxygen delivery: a retrospective study
Authors: Topaz Moris , Ashkenazi Itamar , Barzel Oren , Biswas Seema , Atar Dan , Shadmi Nurit , Siev-Ner Itzhak
Published: March 2021

Background

Following combat-related, extensive soft tissue injury from gunshot wounds or blasts, prolonged duration from injury to full wound closure is associated with infection, increased morbidity and mortality, failure to mobilize, poor functional outcome and increased cost. The purpose of this study was to evaluate a novel treatment enabling early primary closure of combat wounds.

Methods

This was a retrospective study of 10 soldiers and civilians with extensive combat-related soft tissue limb injuries (5 gunshot wounds, 5 blasts) treated using the TopClosure® Tension Relief System (TRS) with simultaneous administration of regulated oxygen-enriched and irrigation negative pressure-assisted wound therapy (ROINPT) via the Vcare α® device.

Results

Nine patients were treated during the acute phase of injury and one was treated following removal of a flap due to deep infection 20 years after injury and flap reconstruction. Two patients had upper limb injury and the rest lower limb injury. With the aid of the TRS and/or ROINPT, immediate primary closure during reconstruction was achieved in 6 patients and delayed primary closure in three. Only one patient required a skin graft to close a small area of the wound after most of the wound had been closed by delayed primary closure. Wound closure was achieved within 0–37 days (median: 12.5 days, interquartile range: 2.75–19.75) from injury.

Conclusions

The TRS is a novel device for effective, early skin stretching and secure wound closure through the application of stress relaxation and mechanical creep, achieving primary closure of large defects using a simplified surgical technique and reducing the need for closure using skin grafts and flaps and the use of tissue expanders. Delivering supplemental oxygen to the wound by ROINPT reverses the reduced oxygen levels inherent in conventional negative pressure-assisted wound therapy, mitigating anaerobic contamination and reducing infection. Irrigation may accelerate the evacuation of infectious material from the wound and provide a novel method for antibiotic administration. The combination of TRS and ROINPT devices allow for early primary closure with improved functionality of combat-related limb injuries.
Improved Hybrid Bag-Boost Ensemble With K-Means-SMOTE–ENN Technique for Handling Noisy Class Imbalanced Data
Authors: Puri Arjun , Kumar Gupta Manoj
Published: March 2021

A class imbalance problem plays a vital role while dealing with classes with rare number of instances. Noisy class imbalanced datasets create considerable effect on the machine learning classification of classes. Data resampling techniques commonly used for handling class imbalance problem show insignificant behavior in noisy imbalanced datasets. To cure curse of data resampling technique in noisy class imbalanced data, we have proposed improved hybrid bag-boost with proposed resampling technique model. This model contains proposed resampling technique used for handling noisy imbalanced datasets. Proposed resampling technique comprises K-Means SMOTE (Synthetic Minority Oversampling TEchnique) as an oversampling technique and edited nearest neighbor (ENN) undersampling technique used as noise removal. This resampling technique is used to mitigate noise in imbalanced datasets at three levels, i.e. first clusters datasets using K-Means clustering technique, SMOTE inside clusters for handling imbalance by inducing synthetic instances of class in minority and lastly, using ENN technique to remove instances that create noise afterwards. Experiments were performed using 11 binary imbalanced datasets by varying attribute noise percentages, and by using area under receiver operating curve as performance metrics. Experimental results confirmed that proposed model shows better results than the rest. Moreover, it is also confirmed that proposed technique performs better with an increased noise percentage in binary imbalanced datasets.
Epicuticular Wax Rice Mutants Show Reduced Resistance to Rice Water Weevil (Coleoptera: Curculionidae) and Fall Armyworm (Lepidoptera: Noctuidae)
Authors: Bernaola Lina , Butterfield Timothy S , Tai Thomas H , Stout Michael J
Published: March 2021

Plant structural traits can act as barriers for herbivore attachment, feeding, and oviposition. In particular, epicuticular waxes (EWs) on the aerial surfaces of many land plants offer protection from biotic and abiotic stresses. In rice (Oryza sativa L.), mutations that reduce EWs have been previously reported. However, whether such mutations affect rice water weevil (Lissorhoptrus oryzophilus Kuschel) and fall armyworm (Spodoptera frugiperda Smith) performance has not been investigated yet. These pests cause significant economic problems in important rice-producing areas of the United States. The aim of our study was to characterize the EWs of EW mutants and wild-type rice plants by gas chromatography–mass spectrometry and compare the resistance of mutant and wild-type plants against rice water weevil and fall armyworm. We hypothesized that mutants with reduced EWs would have weaker resistance to pests than wild-type plants. Three mutant lines (6-1A, 7-17A, and 11-39A) and their wild-type parent (cv. ‘Sabine’) were used to test this hypothesis. Levels of EWs were significantly lower in mutant lines than in the wild-type, and qualitative differences in EW composition were also observed. Reduction in EWs significantly affected performance of insects in experiments conducted under greenhouse conditions. Experiments with rice water weevils were conducted in arenas in which females were given a choice of the mutants and the wild-type for oviposition. Number of first instars emerging from the three EW mutants (an indication of oviposition preference) was higher on the three EW mutants than on wild-type plants with normal wax levels. Similarly, in no-choice experiments using whole plants or detached leaves, weight gains of armyworms on leaves were higher on the mutant lines than on the wild-type. These results indicate that EW traits are involved in rice resistance to weevils and armyworms. Understanding the plant traits that contribute to resistance to rice pests will be helpful for the development of resistant varieties for reducing pest insect damage.
Feasibility and safety of left atrial appendage closure in a patient with previous foramen ovale occlusion: a case report
Authors: Matta Mario , Maltese Ludovica , Ugo Fabrizio , Di Ruocco Maria Virginia , Rametta Francesco
Published: March 2021

Background

Left atrial appendage (LAA) closure is an alternative to chronic oral anticoagulation for stroke prevention in patients with atrial fibrillation (AF) at high bleeding risk. Patients with a previous percutaneous closure of a patent foramen ovale (PFO) present an increased risk for developing AF during their life, and the presence of an atrial septal device renders future percutaneous left atrial access more challenging. Very few cases of LAA occlusion in patients with a preexisting PFO closure device have been previously reported.

Case summary

A 74-years old woman was admitted to our hospital for symptomatic severe anaemia during direct oral anticoagulant treatment. Her past medical history reported an ischaemic stroke at the age of 55, at that time a PFO was diagnosed and a STARFlex™ PFO occluder (NMT Medical, Boston, MA, USA) was implanted. During the current hospitalization, the patient underwent a colonoscopy that showed colonic angiodysplasias unsuitable for endoscopic treatment and LAA closure was indicated for stroke prevention. After a multimodality pre-procedural planning that included a transoesophageal echocardiogram, a cardiac computed tomography scan and a three-dimensional cardiac model printing, the procedure was planned and the LAA successfully occluded.

Discussion

LAA closure can be performed safely and effectively in patients carrying a previously implanted PFO occlusion device. In complex settings, a pre-procedural multimodality imaging is critical for improving the procedural safety and success rate. We describe the first case of percutaneous LAA closure in a patient with a prior PFO occlusion with the implantation of a STARflex™ septal occlusion device.
Comparison of long-term skeletal stability following maxillary advancement using rigid external distraction in growing and non-growing patients with cleft lip and palate: a systematic review and meta-analysis
Authors: Nimbalkar Kunal Ashok , Datana Sanjeev , Agarwal Shiv Shankar , Chopra Sukhbir Singh , Bhandari Sujit Kumar
Published: March 2021

Objectives

To compare the long-term skeletal stability following maxillary advancement using Rigid External Distraction (RED) in growing and non-growing patients with Cleft Lip and Palate (CLP).

Methods

Data sources: A systematic literature search was performed according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines from database inception till August 2020 in MEDLINE-PubMed, Cochrane Central Register of Controlled Trials (CENTRAL), Science Direct, Google Scholar and a manual search in the institutional library. Study eligibility criteria, participants and intervention: All available literature published in English, with a minimum of six human subjects with well-defined age range either 7–14.9 years or 15–30 years, follow up period of a minimum of 12 months assessing the skeletal stability as horizontal change at Point A (Subspinale) following maxillary advancement using a RED device, without the use of rigid internal fixation or bone grafts were included in the study. Study appraisal and synthesis method: The quality assessment of selected articles was done using the Newcastle-Ottawa scale. The meta-analysis was carried out with Q statistic method, I-squared statistics, fixed-effect model to estimate pooled mean and Begg-Mazumdar bias indicator.

Results

Selected nine articles that were qualitatively assessed for relapse rate following maxillary advancement using a RED device, showed consistent and stable results. The meta-analysis found no significant difference in long-term skeletal stability of maxillary advancement by RED device in growing and non-growing patients with CLP [(growing group: Pooled proportion = 0.2927; 95% CI = 0.1534 to 0.4319) (non-growing group: Pooled proportion = 0.23077; 95% CI = 0.09854 to 0.36300)].

Limitations

No study, as revealed by the search, was available that compared the two groups as defined by the inclusion criteria. Data for the two groups were retrieved from different studies and meta-analysed.

Conclusion

RED is an effective modality for correction of maxillary hypoplasia secondary to CLP, requiring large maxillary advancement. The technique can be used in young and adult patients with similar long-term results.

PROSPERO registration number

CRD42020205513