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Accelerating Electric Vehicle Diffusion in South East Asia’s Ride-Hailing Sector: A Diffusion of Innovation Analysis of the Grab-BYD Strategic Partnership
No full textIn the Southeast Asia region, the transport sector is undergoing rapid transformation, being the foremost impact area in the climate agenda over the last few years. Target zero emissions in the transport sector and than focus on EV. This is also the case in the rides sector which is very pivotal in Southeast Asia. A prime example is Grab super app in the region which in partnership with global EV manufacturer BYD is rolling out more than 50,000 EVs across 6 Southeast Asian countries, a first in the region. The author in this paper conducts desk qualitative research where he examines and reconciles information from promotional documents, white papers, and other scholarly and unscholarly literature. This paper utilizes Rogers (1962) Diffusion of Innovation (DOI) theory to explain the collaboration of the manufacturer and the platform in a bid to foster the rapid adoption of EVs among ride-hailing driver-partners. The first of its kind in the region, the partnership positioned itself as an ecosystems orchestrator, and through this collaboration, the partnership transcended the obstacles to the adoption of EVs. Through constructing an entire product with wrapped vehicular access, tailored financing options, extended contractual warranties, and IoT systems, the collaboration targets the ‘early adopter’ and ‘early majority’ segments. This paper contributes to the focus on this distinctive, unprecedented large-scale model diffusion of technology, specifically in the private sector, in emerging markets. The evidence collected suggests that these organized platform collaborations, where technology and dual market are merged, are likely to lead in the intersection of sustainable technology in the Global South
Tidal disruption and evaporation of rubble-pile and monolithic bodies as a source of flaring activity in Sgr A
No full textContext. Sgr A★, the supermassive black hole at the center of the Milky Way, exhibits frequent short-duration flares (e.g., with luminosity > 1034 erg s−1) across multiple wavelengths. The origin of the flares is still unknown.
Aims. We revisited the role of small planetary bodies, originally from the stellar disk, and their tidally disrupted fragments as a source of flaring activity in Sgr A★. In particular, we refined previous models by incorporating material strength constraints on the tidal disruption limit and by evaluating the evaporation dynamics of the resulting fragments.
Methods. We analyzed the tidal fragmentation and gas-induced fragmentation of small planetary bodies with rubble-pile and monolithic structures. Using constraints from recent space missions (e.g., NASA’s OSIRIS-REx and JAXA’s Hayabusa2 missions), we estimated the survivability of fragments under aerodynamic heating and computed their expected luminosity from ablation, modeled as fireball flares analogous to meteor events.
Results. We find that planetary fragments can approach as close as 8 R• due to material strength, where R• denotes the gravitational radius consistent with flare locations inferred from observations. The fireball model yields luminosities from 1034 to 1036 erg/s for fragments whose parent bodies are a few kilometers in size. The derived flare frequency–luminosity distribution follows a power law with the power index 1.83, in agreement with observed values (1.65–1.9), while the flare duration scales as tf ∝ L−1/3, consistent with observational constraints. We considered the discovered young stars around Sgr A★ as the planetary reservoir. Given a small-body population analogous in mass to the primordial Kuiper belt and the common existence of close-in super-Earths as well as long-period Neptunes, we show that this planetary reservoir can provide an adequate supply for the observed flares.
Conclusions. The tidal disruption and thermal evaporation of small bodies offer a plausible explanation for the observed flare properties of Sgr A★
Anomalous reflection coefficient underlying experimentally validated outstanding transmission through metal–dielectric–metal microcavities
No full textAnalytical modelling of light transmission through a metal-insulator-metal geometry embedded in a coupling glass surrounding medium is possible through an extended Fabry-Pérot formula. Two distinct coupled surface plasmon resonance branches are allowed inside such microcavity, where two thin metallic layers act as mirrors delimiting an inner dielectric material. In agreement with transfer-matrix method simulations, the resulting theoretical expressions predict a large and almost constant transmittance even for intracavity thicknesses greater than light’s penetration depth. Results at λ = 800 nm have been validated experimentally and show optical transmittance over 10% until nearly 3 μm. This high transmittance under such unexpected conditions, related to an anomalously high mirror reflection coefficient, sheds light on new possibilities for the design of optical devices. The experimental setup successfully used to corroborate the validity of the transmittance formula over different angular, spectral and geometrical conditions is also presented
Nanosecond green pulse trains generated in a burst-mode by a Cr:YAG Q-switched Nd:YAG laser
No full textWe present the development and characterization of a nanosecond-pulsed Nd:YAG laser operating in burst-mode and passively Q-switched using a Cr:YAG saturable absorber. The system is examined in three configurations: free-running, passively Q-switched, and frequency-doubled using an external KTP crystal. In free-running operation, the laser delivers 618 μs pulse duration with a peak output voltage of 12.47 mV. In the Q-switched regime, four cavity lengths are investigated, showing that shorter cavities significantly reduce the Q-switching threshold while increasing both the repetition rate and the number of pulses within each burst. The optimized 275-mm cavity produces bursts containing up to 22 pulses with 45 ns duration and a 56 mV peak voltage at an intra-burst repetition rate (frep) of 7.142 kHz repetition rate. Pulse energy is estimated from the linear voltage response of an InGaAs fast photodetector to incident optical power. The temporal spacing between consecutive bursts is 13.12 ms, and each burst lasts approximately 250 μs. By integrating an external KTP crystal, second-harmonic generation at 532 nm is achieved, producing 6 ns green pulses with a 65.2 mV peak voltage at an intra-burst repetition rate (frep) of 3.846 kHz. Beam instabilities related to SHG, known as the “green problem,” are also observed. These results provide useful guidelines for optimizing burst-mode Q-switched lasers for efficient nanosecond pulse generation and frequency-doubling applications
Learning from a Pitfall: Atrial Septostomy in LV Failure Under VA-ECMO for Pulmonary Hypertension.
No full textBackground: Atrial septostomy has been successfully used in patients with pulmonary hypertension and in those supported with veno-arterial extracorporeal membrane oxygenation (VA-ECMO) complicated by pulmonary congestion.
Case description: We report a patient on VA-ECMO for decompensated pulmonary hypertension who subsequently developed stress-induced cardiomyopathy and pulmonary congestion. An atrial septostomy was performed, which led to worsening respiratory status due to the creation of a right-to-left shunt, and hemodynamic deterioration resulting from increased left ventricular preload.
Conclusion: The implications of atrial septostomy should be carefully considered prior to decompression as there may be situations especially if right sided pressures are less than left sided pressures where patients may still benefit
Exploring software usage and skills demand in Malaysia’s construction industry
No full textThe Malaysian construction industry is undergoing rapid digital transformation, increasing reliance on specialized software to enhance project efficiency and collaboration. However, a critical software skills gap persists, limiting the ability of professionals to fully leverage emerging technologies such as Building Information Modelling (BIM), data analytics, and cloud collaboration platforms. This study aims to investigate the current demand for software skills, identify technology adoption patterns, and assess gaps between industry needs and educational provisions within Malaysia's construction sector. Data were collected from construction professionals through surveys. Results indicate BIM and project management software are the most valued competencies, with over 80% rating BIM skills as essential. However, significant skill deficits were identified in advanced domains including artificial intelligence, machine learning, virtual and augmented reality. Preferred learning methods emphasize hands on workshops, project-based training, and industry led certification programs over traditional university curricula. The findings highlight a misalignment between current educational offerings and the evolving technological landscape, underscoring the need for enhanced collaboration between academia and industry. This paper recommends prioritizing experiential learning, continuous professional development, and certification to bridge the software skills gap. Addressing these issues will empower construction professionals to better integrate digital tools, fostering improved productivity in Malaysia's construction
Multi-Domain Vibration Diagnosis of Gear Pitting Using a Coupled Torsional-Lateral Spur Gear-Cardan Shaft Model
No full textThis study proposes an in-depth investigation of pitting failures in a complex mechanical transmission system, based on vibration analysis. This system incorporates a spur gear and a Cardan shaft that shows an angular misalignment. A torsionally-laterally coupled dynamic model of 13 degrees of freedom (DOF) is developed using the Lagrangian formulation. This approach accurately represents the dynamic interactions between mesh excitations and kinematic fluctuations induced by the universal joint. The model explicitly incorporates the progressive degradation of mesh stiffness caused by pit distribution on the tooth surface. The dynamic response of the system is numerically simulated under healthy and then defective operating conditions (pitting affecting 25% of the tooth surface). Multi-domain diagnostic analysis is then performed. This method employs time-domain waveform analysis, Fourier transform (FFT) spectral analysis, time-frequency representations (spectrograms), and visualization of lateral displacement orbits. The results clearly highlight the signature of pitting defects: increased vibration amplitude and amplitude modulation in the time-domain signal, the appearance of characteristic sidebands in the frequency spectrum, and a diffuse structure with energy scattered in the time-frequency plane. Crucially, the combined analysis of lateral and torsional responses demonstrates the effective transmission of defect-generated excitations from the gear subsystem to the Cardan shaft subsystem
Experimental Study of Granular Material Flowability in a Heat Exchanger
No full textThis paper presents an experimental investigation of granular material flowability in a heat exchanger. Spherical silicon particles are used as the granular materials in this study. The velocity profile created shows uneven particle velocity where particles towards the outlet flow faster with the velocity reaching 9.09 mm/s and the particles close to the wall flow slower with the velocity reaching 1.63 mm/s. Compared to the Carr classification of flowability proposed in the literature, the angle of repose obtained through the experiment, which is 15°, suggests that the particles are very free flowing. This is supported by the coefficient of rolling resistance which has been obtained as 0.001, suggesting that these particles have a lower rolling friction resistance, leading to a more efficient movement. Moreover, the mass flowrate implies that 140.85 grams of particles flow out per second. These findings suggest that particle size, outlet size, friction factors and the space between the heating elements and the walls affect the flowability of particles in the heat exchanger
Perforation and muffler noise reduction system for a small petrol generator
No full textSouth Africa’s electrical infrastructure deficit and poor maintenance plans have resulted in frequently occurring power outages, which has caused a decline in productivity, alongside an increase in vandalism. As a result, many households and businesses have resorted to alternative energy sources, such as petrol generators. However, petrol generators are loud, reaching acoustic levels of roughly 90 dB, and have proven negative impacts on society and the environment. To reduce the noise intensity produced by small petrol generators, a noise reduction mechanism has been designed. The mechanism incorporates several noise attenuation materials such as porous absorbers and perforated panels. The design also features both passive and active ventilation features for optimal cooling of the generator during use. With flow simulating software embedded in SolidWorks, the temperature, pressure and acoustic power level within the noise reduction mechanism was investigated. The sound box is shown to reduce the noise of the generator to approximately 10 dB, whereas the muffler, can reduce the noise intensity to 37 dB. The overall temperature within the sound box is roughly 75 ˚C, and the maximum pressure was determined to be 103 kPa, which is sufficient for operation of the generator, without compromising its performance and functionality. A modified experimental model was built to validate the numerical results. The results from the experiment produced similar results in terms of decrease in sound when the insulator is added
Physico-chemical and bacteriological quality of groundwater in the Fez–Taza Corridor (Morocco): Impact of urbanization and agricultural activity
No full textThis study assesses the impact of untreated wastewater discharges and agricultural products on the physico-chemical and bacteriological quality of water in the Liasic aquifer of the Fez-Taza corridor. Analysis of the results obtained in this study indicates that the nitrate concentration is too high, reaching a peak value 5 times higher than the norm set by Moroccan standards. What's more, except for aluminium and lead, the concentration of all trace elements studied is below the recommended limits of water quality. From a bacteriological perspective, the groundwater in the Fez-Taza corridor is heavily polluted, with evidence of faecal contamination indicated by elevated levels of total coliforms, faecal coliforms, and faecal streptococci. These results suggests that, in the long term, the use of groundwater may pose a health risk to residences surrounding the Fez-Taza corridor