Current Concepts in Engineering Research and Technology Vol. 3

Pilot Scale Sugar Beet Extraction Using Pulsed Electric Field

2026-07-09T07:22:44+00:00

Pulsed electric field (PEF) treatment is considered an important non-thermal method in food processing. However, despite extensive laboratory-scale studies demonstrating its potential for cell membrane permeabilisation, there is still limited pilot-scale evidence on its effectiveness under continuous processing conditions, particularly regarding its impact on extraction efficiency, energy consumption, and downstream pulp handling in sugar beet processing. The aim of this chapter was to evaluate the impact of high-electric-field pulses on sugar extraction from sugar beet strips during continuous pilot-scale extraction. Fresh sugar beet strips were subjected to high-voltage exponential pulses in a continuous-flow PEF system, followed by diffusion extraction, pressing, and drying. The effects of PEF on cell structure, juice yield, and quality parameters such as °Brix, sucrose content, and purity were evaluated. The results indicate that sugar beet strips can be efficiently extracted at moderate temperatures (35–50 °C) when subjected to PEF pre-treatment. The sugar extraction yield of PEF pre-treated samples ranged from approximately 98.5% to 99.8% for extraction times of 30 and 70 minutes at 50 °C, respectively. In comparison, untreated samples exhibited lower sugar extraction yields (92.5% at 50 °C, 30 min; 94% at 50 °C, 70 min). Pressing of PEF pre-treated extracted pulp was more effective than pressing pulp extracted thermally at 70 °C. Drying of PEF pre-treated extracted pulp was also faster than that of pulp from thermally extracted samples. These findings demonstrate that the PEF technique is an energy- and time-efficient method for continuous sugar beet processing.

Novel V/f Control Strategy with Reference Speed Compensation for Equal Torque Sharing in Multi-Induction Motor

2026-07-09T07:25:06+00:00

Load sharing in conventional V/f-controlled multi-induction motor systems is strongly influenced by parameter mismatch, particularly rotor resistance variation arising from manufacturing tolerances. These variations cause unequal torque distribution among motors operating at a common speed, which may reduce the operational reliability of the drive system. This study proposes a V/f control strategy incorporating a reference speed compensator to improve equal torque sharing between induction motors with mismatched rotor resistances. The method modifies the command frequency and corresponding voltage of the second motor drive according to rotor resistance variation while maintaining constant air-gap flux and the required common operating speed. The proposed approach was evaluated through simulation studies using two-motor load-sharing arrangements with 3-hp and 5-hp induction motors under ±7% rotor resistance variation. Under conventional V/f control, both motors maintained the same speed, but torque sharing remained unequal. In the 3-hp system, the torque contributions were 9 Nm and 7 Nm under a 16 Nm load, whereas the proposed compensator produced equal sharing of 8 Nm each. In the 5-hp system, the torque contributions changed from 19 Nm and 25 Nm under conventional control to 22 Nm each with the compensator under a 44 Nm load. The results indicate that the proposed V/f load-sharing scheme can compensate for rotor resistance mismatch by adjusting the voltage and frequency commands, thereby improving torque sharing without affecting speed synchronisation.

Automated Surgical Lighting Systems: A Narrative Review of Sensing, Actuation, and Control Strategies in Smart Operating Rooms

2026-07-09T07:30:45+00:00

Automated surgical lighting is emerging as an important component of the smart operating room, where illumination must respond to surgical workflow, personnel movement, sterility requirements, and visual-task demands. This narrative review examines automated and semi-automated surgical lighting systems through three linked functional layers: sensing, actuation, and control. The sensing layer includes depth and optical tracking, gesture recognition, voice interaction, gaze- and vision-based contextual awareness, and photometric or colourimetric assessment of illumination quality. The actuation layer includes robotic-arm-mounted luminaires and distributed ceiling-mounted light-emitting diode arrays that can redirect or redistribute light to reduce shadowing. The control layer connects these inputs and mechanisms through optimisation-based shadow management, multimodal interaction, sensor fusion, and early artificial-intelligence-enabled contextual reasoning, while retaining human supervision and manual fallback. Across the literature reviewed, automated lighting is associated with fewer manual adjustments, reduced ergonomic interruption, lower cognitive workload in simulated evaluations, and a plausible reduction in contamination risk by limiting contact with surgical-light handles. However, the evidence base remains limited by small samples, simulation-based testing, restricted validation across surgical specialties, and continuing concerns about algorithmic robustness, user trust, regulatory approval, and integration with hybrid operating-room infrastructure. Automated surgical lighting therefore represents a maturing but still clinically evolving technology that requires further multidisciplinary validation before routine adoption.

Sustainable Concrete Production Using Crumb Tire Ash as a Partial Cement Replacement

2026-07-09T07:34:35+00:00

Concrete production relies heavily on cement, which is costly and contributes to environmental pollution through carbon emissions during manufacture. The growing demand for sustainable construction materials has encouraged the use of alternative cementitious materials. This study investigated the feasibility of using Crumb Tire Ash (CTA) as a partial cement replacement in concrete and evaluated its effects on workability, compressive strength and split tensile strength. Discarded waste tyres were collected from local vulcanisers and recycling centres. CTA was produced by burning and milling waste tyre rubber into fine ash. Laboratory tests, including specific gravity, sieve analysis, slump flow, V-funnel and L-box tests, were conducted to assess the physical and rheological properties of the concrete. Cement was replaced with CTA at 0%, 5%, 10% and 15%, and specimens were cured for 7, 21 and 28 days. The results showed that CTA-modified concrete satisfied fresh concrete requirements; however, increasing CTA content reduced filling and passing ability. The density of the concrete increased with curing age and replacement level but remained within the normal-weight range. The highest average compressive strength at 28 days was obtained at 10% CTA replacement (21.57 N/mm²), compared with 21.18 N/mm² for the control. At 28 days, the 10% CTA mix also recorded the highest split tensile strength (23.57 N/mm²). The findings indicate that 10% CTA is the optimum replacement level within the investigated range, while higher replacement levels adversely affect workability and strength.

Effect of a Solar-Powered Fogging System on Heat Stress Mitigation in HF–Deoni Crossbred Dairy Cattle

2026-07-09T10:23:06+00:00

Background: During summer, environmental conditions may exceed the threshold for heat dissipation in dairy cows, increasing heat gain and inducing heat stress. Elevated temperature and heat stress increase respiration rate, rectal temperature and the temperature-humidity index, thereby affecting cow health. Evaporative cooling systems, including foggers, utilise latent heat of evaporation to reduce ambient temperature and improve animal-house microclimate.

Objective: This study evaluated the effectiveness of a solar-powered fogging system for mitigating heat stress and improving thermal comfort in HF–Deoni crossbred dairy cattle.

Methods: The solar-powered cooling system was developed and installed at the Main Agricultural Research Station, University of Agricultural Sciences, Raichur district, Karnataka, India. The system consisted of foggers, a timer switch, solar panels, a battery, a water tank, a charge controller and a hosepipe. Solar panels supplied energy for pump operation, and the four-way fogger assembly dispersed water to reduce air temperature. The system was assessed at three levels of fogger number (6, 12 and 18), fogger height (2.25, 2.50 and 2.75 m) and operational interval (2, 4 and 6 min). Air temperature (AT), relative humidity (RH) and respiration rate (RR) were measured and analysed.

Results: AT, RH and RR were significantly influenced by the treatment combinations. The optimum treatment, consisting of 18 foggers at 2.75 m height and a 4 min interval, reduced AT by 9.2 °C, RR by 49% (29 breaths min-1) and increased RH by 47% (to 66%). Under this treatment, RR decreased from 59 to 30 breaths min-1. Coefficients of variation were 1.44%, 8.30% and 2.62% for AT, RH and RR, respectively. ANOVA confirmed significant individual and interaction effects on RR (P < 0.001; R2 = 0.987).

Conclusion: The system improved the dairy-shed microclimate by reducing AT, increasing RH and lowering RR in HF–Deoni crossbred cows.

Computational Study on Thermal Behavior of Gas Turbine Blades

2026-07-09T10:31:55+00:00

This study examines heat transfer behaviour in gas turbine blades to evaluate the effect of cooling-hole configuration and blade material on temperature distribution and cooling performance. Gas turbine blades operate in high-temperature environments, where effective cooling is essential for maintaining material stability and reducing thermal stress. A gas turbine blade model was developed using Gambit, and the mesh was generated using CFD (FLUENT) software. The k-e turbulence model was applied for the flow and thermal analysis. Two blade configurations, containing 6 and 12 cooling holes, were analysed using titanium-aluminium alloy and nickel-chromium alloy. The analysis compared temperature distribution, pressure variation and cooling behaviour for the selected material and hole configurations. The results show that increasing the number of cooling holes reduces the temperature distribution across the blade. For titanium alloy, the maximum temperature decreased from 619°C to 395°C, corresponding to a reduction of approximately 36.2%. For nickel alloy, the temperature decreased from 665°C to 400°C, corresponding to a reduction of approximately 39.8%. The 12-hole configuration provided more effective heat dissipation and reduced hotspot formation compared with the 6-hole configuration. Nickel alloy showed better suitability for high-temperature turbine applications due to its thermal strength and more uniform temperature distribution, whereas titanium alloy showed lower overall temperatures but comparatively lower high-temperature suitability.

Millimeter-Wave Propagation for 5G in Tropical Environments: A Comprehensive Study of Channel Characteristics and Rain Attenuation at 28 GHz

2026-07-11T09:56:37+00:00

The deployment of 5G networks in tropical regions presents unique challenges, particularly due to the impact of heavy rainfall on millimeter-wave propagation. This study investigates the propagation characteristics of 28 GHz millimeter-wave signals in outdoor environments, focusing on the effects of rain attenuation. Extensive wideband channel measurements were conducted in both line-of-sight and non-line-of-sight scenarios in Malaysia. The measured data, along with simulation results, were utilized to characterize the 5G channel in terms of path loss, power delay profile, delay spread, and angle of arrival, both with and without the presence of rain. Based on these findings, a comprehensive propagation model was developed, capturing the significant impact of rain on signal degradation and key channel parameters. This model serves as a valuable tool for optimizing the design and deployment of 5G networks in tropical environments, enabling robust high-speed communication despite the challenging atmospheric conditions.

Study of the Effect of Stepped Weir with Roller Bucket Stilling Basin Type on Water Jump Length and Energy Dissipation

2026-07-11T10:02:13+00:00

A stepped weir is a modification of a spillway structure that forms a series of steps from the crest to the downstream foot. Its primary purpose is to dissipate the energy of strong, supercritical flow, thereby reducing the risk of downstream riverbed erosion. The increase in water level caused by the weir changes the flow from supercritical to subcritical conditions, which may lead to erosion in the channel below the spillway. A roller bucket stilling basin is therefore used to reduce scour.

The research was conducted in the Hydraulics Laboratory of the Civil Engineering Study Programme, Faculty of Engineering, Muhammadiyah University of Surakarta. The study used an open flume measuring 30 x 60 x 1000 cm with a channel bed slope of 0.0058. Ogee spillways were tested in three-stage, two-stage and one-stage weir configurations, each combined with a roller bucket stilling basin. The experiments were conducted at five discharge levels. The results showed that the three-stage stepped weir with a roller bucket stilling basin was the most effective configuration for dissipating flow energy because it reduced flow turbulence and hydraulic jump length.