Current Journal of Applied Science and Technology

Cues of Nature: A Critical Appraisal of Mimicry-inspired Biomedical and Engineering Technologies and Their Translational Prospects

B.K. Manjunath, H.B. Kiran Kumar — Thu, 20 Aug 2026 00:00:00 +0000

Nature is routinely invoked as a design archive for medicine and engineering, and the volume of work claiming biological inspiration has expanded faster than the evidence needed to evaluate it. This critical narrative review examines how cues drawn from living systems have been converted into biomedical and engineering technologies, and asks how far the resulting performance claims withstand scrutiny. The review is deliberately cross-domain. It covers interfacial mimicry, including fibrillar and wet adhesion, liquid repellency, atmospheric water capture and contact-mediated antibacterial surfaces; structural mimicry, including hierarchical toughening architectures, protein fibres, structural colour and radiative thermal control; behavioural and systems mimicry, expressed in soft and bioinspired robotics; and molecular or cellular mimicry, expressed in membrane-camouflaged carriers, matrix-mimetic scaffolds, bioprinted constructs and organ-on-chip platforms. Literature was identified through openly accessible scholarly indexes and bibliographic registries, appraised for design adequacy, measurement validity, replication and external validity, and synthesised thematically rather than catalogued. Three findings recur across otherwise unrelated fields. First, the strongest evidence is almost always mechanistic and laboratory-scale, whereas evidence of durable performance under service conditions, and of clinical benefit, is comparatively sparse. Second, the absence of shared metrology means that headline performance figures are frequently incommensurable between laboratories, which obstructs meta-analytic aggregation and encourages selective reporting. Third, the term mimicry is used far more loosely in engineering than in evolutionary biology, where it denotes a specific signalling relationship, and this semantic drift allows superficial resemblance to be presented as functional equivalence. Areas of comparatively secure evidence include hierarchical toughening in ceramic composites, contact-mediated bacterial killing on nanostructured surfaces, and catechol-based wet adhesion chemistry. Areas of weak or contested evidence include durability of liquid-repellent coatings, sustainability claims attached to biomimetic design, and the assumption that data-driven design tools resolve rather than relocate the underlying validation problem. The review proposes prioritised research directions centred on standardised reporting, service-condition testing and preregistered comparative studies.

Design and Evaluation of a Lightweight, Low-Cost Hybrid Solar–Wind Energy Harvesting System for Portable Power Generation in Long-term Hiking

Dominick Chang — Fri, 07 Aug 2026 00:00:00 +0000

Reliable access to electrical power remains a major challenge during long-distance hiking and expedition travel in which grid electricity is unavailable. This study presents the design, construction, and experimental evaluation of a lightweight, low-cost hybrid solar–wind energy harvesting system for portable power generation. The system integrates a commercially available portable solar panel, a compact vertical-axis wind turbine, independent power-conditioning circuits, INA219 current sensors, Arduino-based monitoring, and USB power-bank energy storage. Indoor calibration experiments established voltage–illuminance and wind-speed–voltage relationships, while outdoor testing quantified actual charging performance under winter field conditions. The solar subsystem harvested approximately 19 Wh over an effective charging period of 4.5 h, corresponding to approximately 1–1.5 full charges of a 3,000 mAh smartphone under the tested conditions. Wind-turbine calibration demonstrated a positive nonlinear relationship between wind speed and electrical output, supporting its role as a complementary energy source under low-light conditions. The hybrid architecture improves reliability, portability, and energy availability for extended outdoor activities while remaining inexpensive and reproducible. The system integrates a commercially available portable solar panel and a compact vertical-axis wind turbine. Wind energy is converted from three-phase alternating current to direct current using a three-phase bridge rectifier. Both the solar and wind outputs are regulated to a standard 5 V direct-current output. Energy is stored in a commercial USB power bank containing internal lithium-ion cells. Under winter conditions, the measured 19 Wh of harvested energy corresponded to approximately 1–1.5 full charges of a 3,000 mAh smartphone per day. With increased solar irradiance and a longer daylight duration during the summer months, seasonal output is expected to increase substantially, potentially supporting multiple full device charges per day under optimal conditions. The hybrid configuration improves system robustness and energy security for extended remote outdoor use.

Building Digital Trust under Uncertainty: How Online Retail Firms in Ghana Manage Cybersecurity and Privacy Risks

Kwasi Owusu-Antwi, Samuel Lomotey, Fortune Edem Amenuvor — Mon, 10 Aug 2026 00:00:00 +0000

The rapid expansion of digital commerce in emerging markets has created significant opportunities for economic participation while simultaneously introducing new challenges related to cybersecurity, data privacy, and consumer trust. Although existing research has extensively examined perceived risk and online purchase behaviour from the consumer perspective, limited attention has been given to how online retail firms strategically manage cybersecurity risks and construct digital trust within emerging market contexts.

This study addresses this gap by exploring how online retail firms in Ghana respond to consumers’ perceived risks associated with internet security breaches and data privacy. Drawing on the Technology-Organization-Environment (TOE) Framework and Perceived Risk Theory, the study adopts a qualitative exploratory research design based on semi-structured interviews with nine participants drawn from nine online retail organisations operating in Ghana. Thematic analysis was employed to identify patterns related to cybersecurity practices, organisational capabilities, environmental influences, and trust-building mechanisms.

The findings reveal four key themes: (1) consumer behaviour as a persistent source of digital vulnerability, (2) cybersecurity as an organisational capability rather than merely a technical function, (3) external partnerships as mechanisms for overcoming resource constraints, and (4) the translation of security practices into consumer trust and confidence.

The study contributes to the digital commerce literature by shifting attention from consumer adoption perspectives towards the organisational processes through which digital trust is created, communicated, and sustained. The findings demonstrate that effective cybersecurity management in emerging markets requires an integrated approach that combines technological investments, organisational readiness, ecosystem collaboration, and consumer-oriented communication strategies. The study provides important implications for online retailers, policymakers, and other digital ecosystem stakeholders seeking to develop secure, trustworthy, and sustainable e-commerce environments in emerging economies.

Green Synthesized TiO₂ Nanoparticles from Calotropis gigantea Leaves for Anti-inflammatory Biomedical Applications

D. Vijayakumar, M. Prabhu, A. Jayas Faniya, M. Keerthika, A. Susmitha — Mon, 10 Aug 2026 00:00:00 +0000

Environmentally sustainable synthesis of nanomaterials offers an alternative to conventional preparation methods that may involve toxic chemicals and high energy consumption. This study synthesised titanium dioxide nanoparticles (TiO₂ NPs) using an aqueous extract of Calotropis gigantea leaves as a reducing and stabilising agent and evaluated their preliminary anti-inflammatory and cellular effects. Reaction parameters, including pH, temperature, and extract concentration, were optimised, and the recovered material was calcined at 450°C for 3 h. Anti-inflammatory activity was assessed using human red blood cell (HRBC) membrane stabilisation and bovine serum albumin (BSA) protein denaturation assays, with diclofenac sodium as the reference standard. HRBC membrane protection increased from 11% at 0.6 mg/mL to 82% at 3.0 mg/mL, with a reported IC₅₀ value of 1.65 mg/mL. Inhibition of BSA denaturation increased from 9% at 500 µg/mL to 60% at 2500 µg/mL, with a reported IC₅₀ value of 1643 µg/mL. Diclofenac sodium showed greater activity in both assays. JC-1 staining of HepG2 cells showed a shift from red to green fluorescence after nanoparticle exposure, indicating changes in mitochondrial membrane potential. The findings demonstrate concentration-dependent membrane stabilisation and protein denaturation inhibition, together with measurable mitochondrial-level interaction. These results support further investigation of green-synthesised TiO₂ nanoparticles, although detailed physicochemical characterisation, quantitative cytotoxicity assessment, and additional mechanistic validation are required before biomedical application can be considered.

Comparative Study of Stromeyer, Basquin and Wöhler Fatigue Models Using Shot-peened and Electroless Nickel Plating Metal

Rimyalegdo Kiébré, Souleymane Ramdé, Vasilieos Kourakos — Tue, 11 Aug 2026 00:00:00 +0000

This study compares the Stromeyer, Basquin, and Wöhler fatigue models for E235 steel under three surface conditions: untreated, shot-peened, and shot-peened followed by electroless nickel coating. Fatigue specimens were extracted from a pump-rotor section selected to represent a region susceptible to service-related cracking. Tests were conducted in air at room temperature under force control, with a mechanical stress ratio of 0.1, a frequency of approximately 60 Hz, and a stopping criterion of 2 × 10^6 cycles or a 2 Hz reduction in test frequency. The experimental results were analysed using the ESOPE software to estimate model parameters, fatigue limits, standard deviations, and rejection rates. For the untreated condition, the Stromeyer model produced a converted fatigue-limit estimate of 344.6 MPa and a rejection rate of 75.82%. Shot peening increased the corresponding estimate to 419.8 MPa and reduced the rejection rate to 31.57%. Following electroless nickel coating, the estimated value decreased to 299.6 MPa, while the rejection rate increased to 86.69%. Among the examined conditions, the shot-peened specimens therefore showed the highest estimated fatigue resistance and the lowest rejection rate. The results indicate that model performance varies substantially with surface condition and experimental scatter. Under the tested conditions, the Stromeyer model provided the most consistent representation of the shot-peened dataset, whereas the untreated and nickel-coated datasets showed greater variability and lower fitting reliability.

Fractal Modeling of Gas Transport in Gas Diffusion Layers (GDLs) for Enhanced Electrochemical Performance of PEMFCs

Tue, 11 Aug 2026 00:00:00 +0000

Proton exchange membrane fuel cells (PEMFCs) are among the most promising technologies for advancing the energy transition, particularly in clean transportation and decentralised power generation. However, improving their performance requires a detailed understanding of mass-transport processes within gas diffusion layers (GDLs), which play a key role in supplying reactants to electrochemically active sites and managing transport limitations.

This study proposes a coupled multiscale and multiphysics approach that links the fractal microstructure of the GDL to the macroscopic electrochemical performance of the fuel cell. The objective is to identify optimisation criteria for the design of high-performance GDLs, with particular emphasis on selecting an optimal fractal tortuosity dimension. The numerical framework, implemented in Python, combines the generation of fractal tortuosity characteristics, the estimation of effective transport properties, and the simulation of polarisation and power-density curves.

The results show that for a fractal tortuosity dimension (D_T< 1.5), gas transport is enhanced, although this improvement occurs at the expense of the available electrochemically active surface area. A value of (D_T= 1.53) therefore appears to provide an optimal compromise, leading to a peak power of 0.86 W/cm² and a voltage efficiency of approximately 57.8%. Conversely, for (D_T> 1.7), the increase in catalytic surface area is associated with stronger limitations in gaseous species transport. These findings demonstrate the relevance of fractal modelling as a useful tool for guiding the design and optimisation of gas diffusion layers in PEMFCs.

Experimental Analysis of the Thermal Field and Energy Balance of a Wood-fired Bakery Oven during the Preheating Phase

Tue, 18 Aug 2026 00:00:00 +0000

Preheating determines the amount of thermal energy stored in refractory components before baking and is therefore central to the operation of a wood-fired bakery oven. This study experimentally characterised the thermal behaviour and energy balance of an industrial wood-fired bakery oven used in Burkina Faso. Exterior wall and flue-gas temperatures were monitored during preheating after a long period of inactivity and during reheating between successive baking cycles. The exterior wall temperatures remained below 60 °C, whereas the oven openings showed greater heat dissipation. The flue-gas temperature exhibited three successive regimes: initial combustion stabilisation, progressive heat storage in the refractory materials, and a later rapid temperature increase associated with a reduction in the instantaneous capacity of the refractories to absorb additional heat. For preheating after prolonged inactivity, the energy balance showed that wall losses accounted for approximately 4% of the fuel energy and flue-gas losses for approximately 35%, while about 61% was stored in the oven. The reported storage efficiency was also approximately 61% during preheating after baking. Although a longer preheating period and greater fuel consumption were required after prolonged inactivity, the proportion of energy stored remained similar. These findings indicate that energy performance during preheating is influenced more strongly by flue-gas and opening losses than by heat transfer through the insulated walls. The results provide an experimental basis for improving preheating management and reducing avoidable heat losses.

Technical Design and Optimal Sizing of a Photovoltaic-Wind Hybrid System for Rural Electrification: Case Study of Tafaghatt, Niger

Moumouni Guero Mohamed, Prodjinonto Vincent — Tue, 18 Aug 2026 00:00:00 +0000

Rural electrification remains one of the most persistent gaps in Sahelian energy access, and this study responds to it with a fully transparent, resource-adapted engineering methodology for sizing a photovoltaic-wind hybrid system rather than another generic feasibility exercise. What sets this work apart within the broader body of Sahelian hybrid-system literature is its combination of decade-long, site-specific satellite climatic data with a sizing method deliberately kept hand-calculable and free of proprietary optimisation software, so that it can be reproduced directly by field engineers and small technical offices, an approach that most comparable village-scale studies bypass in favour of commercial optimisation suites. The village of Tafaghatt, an off-grid settlement about 18 km north of the Aguié department in Niger's Maradi region (13.65° N, 7.71667° E), anchors the case study. Its daily electricity demand, estimated at 160 kWh/day from a disaggregated, appliance-level load inventory and a diversity factor benchmarked against comparable Sahelian villages, is split between the two renewable sources according to what the local resource can actually support: 75% (120 kWh/day) to the photovoltaic subsystem and 25% (40 kWh/day) to wind, a resource-driven allocation whose plausibility is cross-checked here against an independently HOMER Pro-optimised comparable Sahelian case that reached the same ratio. Solar and wind resources were characterised from ten years (2012-2021) of NASA, PVGIS and Meteorum climatic data, cross-validated against one another and processed through a dedicated MATLAB extrapolation script, yielding a mean daily solar irradiation of 5.60 kWh/m²/day and a mean wind speed of 4.49 m/s at the village site. Using the least-favourable-month sizing method, the photovoltaic field comprises 57 monocrystalline modules of 500 Wc (28.5 kWc), backed by a lithium iron phosphate battery bank of 240 kWh nominal capacity sized for 10 hours of autonomy, while the wind subsystem points to a 10 kW, 6.5 m-diameter turbine mounted at 35 m hub height. The complete hybrid system has a total installed capacity of 38.5 kW and should deliver about 64.1 MWh per year. This paper deliberately confines itself to technical design and sizing; the techno-economic feasibility (investment cost, levelised cost of energy, payback) and the environmental impact assessment of this same 38.5 kW configuration are the subject of a forthcoming companion paper. Beyond Tafaghatt, this work offers a fully replicable, resource-adapted sizing methodology for small PV-wind hybrid mini-grids across the Sahel.