The Survival of the Yorùbá Healing Systems in the Modern Age

This study investigates the philosophy and tradition of the Yorùbá healing system and the reasons for its survival into the modern age. The introduction of western-style healthcare by missionaries—which became consolidated under colonial rule, from any point of view was attempted to stiffen the survival of the former. Intentionally or inadvertently, the Yorùbá healing system was derogatorily deemed primitive and unscientific because of its ritualistic aspects, which were severely condemned. The activities of missionaries in the context of proselytism and colonial governmental policies entailed copious attempts to stifle and do away with the Yorùbá healing system. This study uses historical analysis to synchronize the factors that helped the Yorùbá healing system to survive in a threatening milieu, namely the pressures of western ideology. The study concludes that despite efforts by the propagators of western ideology, the Yorùbá healing system is still a highly favored form of healthcare in Yorùbáland.

Boronic Ester-Polyurethane as a Self-Healing Coating Material for Offshore Top Side Structures Application

Polymer coatings, especially epoxy and polyurethane paint systems, have been widely used to prevent corrosion of metallic components and structures. However, due to environmental and mechanical effects, the barrier efficiency of the coatings may be substantially compromised during transportation and service, as demonstrated by localized scratches, delamination, or stress-related microcracks. Application of a self-healing coating that can restore damages and recover its performance with minimal external intervention could prevent corrosion at the damaged coating. In this present work, the healing efficiency and long-term durability of Boronic Ester (BE) blended with Polyurethane (PU) as a self-healing system for top side coating of offshore platform structures was investigated. The BE was mixed at a ratio of 50:50 with PU resin and applied as a top layer on a PU coated steel plate with a thickness of approximately 300-350 μm. The healing efficiency, mechanical performance, and durability under simulated environmental conditions such as salt spray and UV were investigated according to the related ASTM standards. As a first step, the electrical impedance spectroscopy (EIS) and 3D profilemeter microscope were used to assess the healing ability of the scratched coating at room temperature and humidity level of 85 %. The mechanical performance of the self-healing coating layer was evaluated using a pull off adhesion test to investigate the compatibility of the self-healing system with the existing commercial PU topcoat system, while a long term 3000 hours salt spray and 4200 hours cyclic UV test were performed to evaluate the self-healing coating's durability in harsh conditions. Preliminary assessment using EIS and 3D profilemeter microscopes on the scratched PU/BE self-healing coating revealed significant healing efficiency of more than 80% for healing condition at ambient temperature and humidity level of 85%. The self-healing coating layer also demonstrated excellent adhesion efficiency, with adhesion greater than 300 psi suggesting good compatibility of the BE-PU layer with commercial PU coating. The salt spray and cyclic UV tests that were performed to determine the durability of the self-healing coating revealed that the 50BE/50PU layer remained intact and exhibited good healing performance with more than 80% efficiency even after exposure to harsh conditions. The findings from the study demonstrated that the BE/PU material has the potential to be used as a self-healing system for topside coating of offshore platforms structures, thereby lowering maintenance costs.

Preparation and Mechanical Properties of Microcapsule-Based Self-Healing Cementitious Composites

Self-healing concrete designs can protect against deterioration and improve durability. However, there is no unified conclusion regarding the effective preparation and mechanical properties of self-healing concrete. In this paper, microcapsules are used in cement-based materials, the reasonable dosage of microcapsules is determined, and the self-healing performance of the microcapsule self-healing system under different curing agents is explored. The microcapsules and curing agent are shown to enhance the flexural and compressive strength of mortar specimens at relatively low contents. The optimal microcapsule content in terms of compressive strength is 1–3%. When the content of the microcapsule reaches 7%, the strength of the specimen decreases by approximately 30%. Sodium fluorosilicate is better-suited to the microcapsule self-healing cement-based system than the other two fluorosilicates, potassium fluorosilicate and magnesium, which have similarly poor healing performance as curing agents. Healing time also appears to significantly influence the microcapsule self-healing system; mortar specimens that healed for 28 days are significantly higher than those that healed for 7 days. This work may provide a valuable reference for the design and preparation of self-healing cementitious composite structures.

Conductive Compartmented Capsules Encapsulating a Bitumen Rejuvenator

This paper explores the potential use of conductive alginate capsules encapsulating a bitumen rejuvenator as a new extrinsic self-healing asphalt method. The capsules combine two existing self-healing asphalt technologies: (1) rejuvenator encapsulation and (2) induction heating to create a self-healing system that will provide rapid and effective asphalt pavement repair. The work presents a proof of concept for the encapsulation process, which involves embedding the capsules into the bitumen mortar mixture and the survival rate of the capsules in the asphalt mixture. A drip capsule production process was adopted and scaled up to the production of 20l wet capsules at rate of 0.22 l/min. To prove the effectiveness and its ability to survive asphalt production process, the capsules were prepared and subjected to thermogravimetric analysis (TGA) and uniaxial compression Test (UCT). The test results demonstrated that the capsules had suitable thermal characteristics and mechanical strength to survive the asphalt mixing and compaction process. Scanning electron microscopy (SEM) was employed to investigate physiological properties, such as rejuvenator (oil) and iron particle distribution, within the capsules. The electrical resistance tests proved that the capsules were capable of conducting electrical current. The capsules were also tested for their conductive properties in order to determine whether they are capable of conducting and distributing the heat once subjected to induction heating. The results showed that capsules containing higher amounts of iron (alginate/iron powder in a ratio of 20:80 by weight) can efficiently conduct and distribute heat. To prove its success as an asphalt healing system, conductive alginate capsules encapsulating a bitumen rejuvenator were embedded in a bitumen mortar mix. The samples where then subjected to local damaging and healing events, and the degree of healing was quantified. The research findings indicate that conductive alginate capsules encapsulating a bitumen rejuvenator present a promising new approach for the development of an extrinsic self-healing asphalt pavement systems.

Influencing Factors on the Healing Performance of Microcapsule Self-Healing Concrete

The amounts of the components in a microcapsule self-healing system significantly impact the basic performance and self-healing performance of concrete. In this paper, an orthogonal experimental design is used to investigate the healing performance of microcapsule self-healing concrete under different pre-damage loads. The strength recovery performance and sound speed recovery performance under extensive damage are analyzed. The optimum factor combination of the microcapsule self-healing concrete is obtained. Scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) are carried out on the concrete samples before and after healing to determine the healing mechanism. The results show that the healing effect of self-healing concrete decreases with an increase in the pre-damage load, and the sound speed recovery rate increases with an increase in the damage degree. The influence of the sodium silicate content on the compressive strength and compressive strength recovery rate of the self-healing concrete increases, followed by a decrease. The optimum combination of factors of the microcapsule self-healing system is 3% microcapsules, 30% sodium silicate, and 15% sodium fluosilicate. The results can be used for the design and preparation of self-healing concrete.

Experimental Investigation of the Performance of a Hybrid Self-Healing System in Porous Asphalt under Fatigue Loadings

Self-healing asphalt, which is designed to achieve autonomic damage repair in asphalt pavement, offers a great life-extension prospect and therefore not only reduces pavement maintenance costs but also saves energy and reduces CO2 emissions. The combined asphalt self-healing system, incorporating both encapsulated rejuvenator and induction heating, can heal cracks with melted binder and aged binder rejuvenation, and the synergistic effect of the two technologies shows significant advantages in healing efficiency over the single self-healing method. This study explores the fatigue life extension prospect of the combined healing system in porous asphalt. To this aim, porous asphalt (PA) test specimens with various healing systems were prepared, including: (i) the capsule healing system, (ii) the induction healing system, (iii) the combined healing system and (iv) a reference system (without extrinsic healing). The fatigue properties of the PA samples were characterized by an indirect tensile fatigue test and a four-point bending fatigue test. Additionally, a 24-h rest period was designed to activate the built-in self-healing system(s) in the PA. Finally, a damaging and healing programme was employed to evaluate the fatigue damage healing efficiency of these systems. The results indicate that all these self-healing systems can extend the fatigue life of porous asphalt, while in the combined healing system, the gradual healing effect of the released rejuvenator from the capsules may contribute to a better induction healing effect in the damaging and healing cycles.

Integrated 8 Wisdom Compounds Interaction in Multitasking Healing System: Confinement Energy in 4D Frequency Interconnection

The total energy in multitasking healing system of herbal medicine is extremely important due to an effective recovery of treated cells or organs in human body. This short communication research reports an exact calculation of the total effective mass involve in multitasking healing system of herbal medicine based on a simple smart model from general physics implemented in organic complex compounds found normally in Maluku/ Halmahera Galoba fruits (Zingiberaceae spp.) such as Amomum spp., Hornstedtia spp., Elim alliacea, Etlinger alba (Blume) A.D. Poulsen, et cetera. The invented results shows that the total mass involved in such multitasking healing system is ~24.24% with the total number of on-target atoms of ~93 atoms from 382 total atoms. This finding suggests that the healing time of herbal medicines with multitasking healing system shall be slower that that from FDA pharmaceutical approved products which is one target with ~100% healing system. The value of strong confinement energy in multitasking healing system of such 8 wisdom compounds in herbal medicine based Galoba fruits is about 4 time larger than its weak confinement energy

Graphene Oxide-Modified Microcapsule Self-Healing System for 4D Printing

Self-healing materials as a type of promising smart materials are gradually applied to electronics, biology, and engineering. In this study, we used in situ polymerization to make melamine-formaldehyde (MF) resin microcapsules to wrap the epoxy oxide as a repairing agent and Cu(MI)4Br2 as a latent-curing agent to protect epoxy oxide E-51 from broken melamine-formaldehyde resin microcapsules. In addition, graphene oxide was used as a reinforcing phase through its two-dimensional-layered structure to increase the tensile strength to 41.91 MPa, which is higher than the initial materials. The melamine-formaldehyde capsules and latent-curing agents were uniformly distributed in the materials according to the digital photos and scanning electron microscope (SEM) pictures. It is worth noting that the mechanical strength of the broken materials can be restored to 35.65 MPa after heating to 130°C for 2 h to repair the damage, and the self-healing efficiency reached up to 85.06%. Furthermore, we also fabricated the 4D printed material with a tensile strength of 50.93 MPa through a 3D printer. The obtained materials showed excellent repair effect, with a recovery rate of up to 87.22%. This study confirms that the designed self-healing system has potential applications in many areas due to its excellent self-healing performance, which provides valuable guidance for designing the 4D system.