Purbanchal University

The rapid adoption of electric vehicles (EVs) globally demands expanded charging infrastructure; however, their unplanned integration into radial distribution systems (RDS) often causes voltage instability, high power losses, and system inefficiencies. This study optimizes the placement and sizing of solar photovoltaic-battery system (PV-BESS) in Nepal's 30-bus Byasi feeder to mitigate these issues. Employing particle swarm optimization (PSO) and MATLAB/Simulink, the proposed approach reduces active power loss by 56.18 % (477 kW-209 kW) and improves minimum bus voltage by 2.57 % (0.9404-0.9646 p.u.) through integration of 2576 kW PV and 1311 kW BESS. The application of novel energy management strategy further curtails peak demand by 38.3 % (3700 kW-2283 kW). The solution achieves financial viability with approximately 9-year payback period. This research pioneers a comprehensive technical-operational-economic assessment for EV charging-oriented PV-BESS planning in Nepal's RDS, demonstrating how weighted multi-objective optimization balances power loss reduction and voltage improvement while ensuring economic feasibility. The findings provide a replicable framework for sustainable EV infrastructure development in similar distribution networks, highlighting the critical importance of strategic renewable energy integration for grid stability. The study's methodology and results offer valuable insights for utilities and policymakers addressing EV charging infrastructures challenges in developing power systems.

Sclerotium rolfsii Sacc. is a destructive soil-borne pathogen causing collar rot in chili (Capsicum spp.) and several other diseases in many economically important crops. This study evaluated the efficacy of nine fungicides representing different chemical classes (triazoles, strobilurins, benzimidazoles, dithiocarbamates, and contact fungicides) against S. rolfsii using the poisoned food technique under in vitro conditions at 25, 50, and 100 parts per million (ppm) concentrations. Most systemic fungicides significantly inhibited mycelial growth compared to the untreated control, whereas captan, copper oxychloride, and mancozeb showed poor inhibition at lower concentrations. The highest inhibition of mycelial growth over control was observed with carboxin + thiram (91.25

On 26 August 2026 a rock–ice avalanche on the north face of Langtang Lirung, Nepal, initiated a debris flow and flood that ran roughly 100 km down the Lhende Khola, Bhote Koshi and Trishuli. Several contemporaneous reports asserted that satellite radar had tracked a month of accelerating slope movement before failure; that assertion has not been substantiated in published analysis. Using Copernicus Sentinel-1 IW GRD amplitude on a single relative orbit, this note (i) locates the failure independently and (ii) tests directly for a precursory signal. Co- and cross-polarised change between 16 and 28 August is concentrated on the reported detachment coordinate: within 500 m, 30.0% of VV pixels and 25.4% of VH pixels changed by more than 6 dB, against 0.8% and 0.4% respectively across the remainder of a 308 km² scene. Across five pre-event passes from 29 June to 16 August, measured against 80 terrain-matched control patches, VV shows a nominally significant negative trend (−0.20 ± 0.03 dB cycle⁻¹ across independent control draws, p ≈ 0.02) that is produced entirely by the first scene of the series; excluding it, the remaining four dates are flat (+0.01 dB cycle⁻¹, p = 0.99). VH shows a monotonic rise (+0.62 ± 0.03 dB cycle⁻¹, p < 0.01, robust to exclusion of either endpoint) which is rejected by a same-orbit seasonal baseline: in 2025 the equivalent rise occurred earlier and had completed by late June, whereas in 2026 the face was 3.05 dB below the 2025 plateau at the same date and subsequently rose 2.87 dB. The apparent precursor is the completion of a delayed seasonal transition. No precursory signal is present in the freely available amplitude record at 12-day sampling; the detection limit is approximately 1 dB of progressive change over two months.

On 26 August 2026 a rock–ice avalanche detached from Langtang Lirung, Nepal, and released a debris flood that crossed the Nepal–China border. Deformation preceding the failure has since been reported from a multi-month Sentinel-1 stack, and pre-event indications have been identified in commercial optical imagery. Both analyses began from a known failure location. This paper asks a different question: what routine, freely available Sentinel-1 products contained at the last acquisition before failure, and how large a signal would have had to be before they contained something. Three quantities are tested on a 500 m disc over the detachment — backscatter amplitude, interferometric coherence, and line-of-sight displacement from unwrapped phase — each against 120 control discs in the same scene matched on local incidence angle, aspect and slope, and against the source’s own history over the preceding two months. The last usable descending acquisition precedes failure by 50.6 hours. No quantity distinguishes the source from comparable slopes or from its own quiet behaviour: amplitude at the 67.5th percentile of controls, coherence third of five quiet intervals, cumulative displacement at the 31st percentile. The same statistics identify the collapse decisively once it falls inside the observation interval, at z = 4.57 in coherence and below all 120 controls in amplitude, so these are calibrated limits rather than uninformative nulls. No surface disturbance above approximately 2 ha of coherent decorrelation occurred in the twelve days ending 50.6 hours before failure, and no line-of-sight displacement above approximately 13 mm per month occurred over the preceding seven weeks. That bound lies above the rate reported from the multi-month stack, which is the substantive result: the deformation was measurable from orbit using free archived data, but not by the twelve-day products a monitoring service would have been screening.

The half-fringe limit of a repeat-pass interferogram is quoted as a property of the sensor: a quarter wavelength of line-of-sight displacement per pair. On a slope it is not. Sensitivity to downslope motion is f = |m · u|, and at a mountain source f varies with the track, with the site, and across the source itself. We compute f per pixel over 500 m source discs at two rock–ice avalanche sources, Langtang Lirung (Nepal, 2026) and Ronti Peak (India, 2021), on four Sentinel-1 relative orbits, from a 30 m DEM, look azimuths measured from product footprints, and incidence angles measured directly from on-demand interferometric products. Expressed as a downslope rate, the single-pair ceiling is 0.46 m/yr on Langtang descending and 2.77 m/yr on Langtang ascending: a factor of 6.0 between two geometries of the same sensor, over the same source, in the same week. At Ronti the same comparison gives 1.25. How track-dependent the ceiling is, is itself site-dependent. Within a single 500 m disc, f spans 1.3× on Langtang descending and 13.6× on Langtang ascending, so on most geometries the ceiling is not a value for the source but a distribution across it. This accounts physically for a result previously reported as an empirical curiosity — that the best-covered geometry measures worst — because near-normal incidence is simultaneously the condition for full coverage, for insensitivity to downslope motion, and for the widest internal spread in sensitivity. We then measure the other instrument's limit at the same source: the detection floor of single-pair optical pixel-offset tracking, from 28 Sentinel-2 pairs against a prespecified stable-ground control. That floor does not improve with separation (sigma ~ T^0.25) and is set instead by scene-pair condition, which the quantity most easily computed before processing, tile cloud cover, fails to predict. Joint screening on snow and cloud over the source area halves the spread and halves the median floor, and roughly doubles the number of pairs in which a published pre-failure rate of 9.6 m/yr downslope would have been detectable. The floor reproduces at the second site, 5.77 against 5.55 m/yr, once pairs spanning that site's own failure are removed — those decorrelate the control area itself, at twenty-five times the dispersion of a same-separation pair that does not span it. Neither instrument detects the published rate in a single routine product on any geometry examined. A null from a 12-day pair is uninterpretable without the projected ceiling for that specific track, and λ/4 is not sufficient.