Morphology Study of Particle Breakage Mechanisms in a Horizontal Stirred Mill: Automated and Manual Point Counting Approaches

High-speed stirred mills are utilized to grind particles below 10mm. Grinding sulphide minerals to as low as 10mm achieve adequate mineral liberation for successful downstream mineral processing operations, such as flotation and leaching. Particle breakage mechanism such as fracture or abrasion, determines the morphological surface features of the product particles. It is anticipated that particles, which break along grain boundaries (intergranular) produce rough surfaces, whereas particles that break across the grain boundaries (transgranular) possess smoother surfaces. In this study, particles are ground in a stirred mill and their morphological features were analyzed using automated and manual detection methods. Literature and conventional belief are that high-speed stirred mills break particles by attrition. This paper showed that fracture is also an important breakage mechanism along with attrition. Breakage mechanism is a factor of input stress intensity, in the form of the mill agitator speed, and type of mineral. It is observed that at higher agitator speed galena fractures along the grain boundaries, whereas quartz, abrade across the grain boundaries.

Impacts of bird abundance, activity height and light intensity on the number of birds captured by mist netting

To understand better the impact on mist net capture rates of the activity height of birds, light intensity, bird richness and abundance, we compared data from mist nets and point counts at the Jianfengling Forest Area, Hainan Island. Mist-nets were operated for a total of 7135 net-hours. A total of 587 individuals of 45 bird species were captured. The total mean capture rate was 8.6 ± 10.4 per 100 net-hours. A total of 4932 individuals of 107 bird species were recorded by visual observation alone and 7616 individuals of 120 species were recorded in a visual and aural combination. The Grey-cheeked Fulvetta (Alcippe morrisonia) was the most abundant species, accounting for 38.7% of total captures, 27.9% of visual observations and 22.2% of visual + aural observations. The capture number was correlated with the number observed. Thirty-one species were more likely to be captured than observed. Canopy species, such as members of the Corvidae and Dicruridae, were seldom captured. For all ground feeding species, the capture number was greater than that of observation. Some cryptic species, such as the Lesser Wren Babbler (Napothera epilepidota), Spotnecked Babbler (Stachyris striolata) and Cuckoo Owl (Glaucidium cuculoides) also had a higher relative capture rate than that of observations. There was a significant relationship between light intensity and the number of birds captured.

Population assessment and habitat associations of the Visayan Hornbill(Penelopides panini)in Northwest Panay,Philippines

Background:Seven out of ten hornbill species in the Philippines are threatened with extinction.Among these is the endangered Visayan Hornbill(Penelopides panini),found on the islands of Panay and Negros.Threatened by habitat loss and hunting,its population size is thought to have declined from 1800 individuals 20 years ago to less than 1000.However,a recent study on Negros estimated 3564 individuals across three core forest blocks.This study aims to quantify the Visayan Hornbill population size in and around the Northwest Panay Peninsula Natural Park(NWPPNP)on Panay,the largest contiguous low-elevation forest landscape remaining across its range,and its broad habitat associations across a gradient of environmental degradation.Methods:Hornbills were surveyed using 10-min distance sampling point counts(n=367)along transects(average length 1.1 km).Environmental variables were recorded along transects,while habitat was classified into primary forest,secondary forest,plantation,or open habitat.Distance software was used to estimate population densities stratified by habitat,with the overall population estimate taken as a mean of habitat density estimates weighted by habitat area.Using generalized linear mixed models,hornbill occurrence was modelled using combinations of nine environmental variables as main and two-way fixed effects.Results:Surveys covered 204.4 km^(2) of the 374.8 km^(2) Northwest Panay Peninsula.Hornbills were not recorded in plantations or open habitats.Hornbill density was significantly higher in primary forest(17.8 individuals/km~2±26.9%CV)than in secondary forest(3.7 individuals/km^(2)±33.2%CV;z=15.212,P<0.001).The overall population estimate for the NWPPNP and environs is 2109 individuals,and 2673 individuals for the entire Northwest Panay Peninsula.Hornbill presence was best explained by a model including distance from the Park boundary alongside five interaction effects and transect as a random effect.Distance,and the interaction between distance and medium-sized trees were significant predictors of hornbill presence.Conclusions:Our study evidences the habitat preference of the Visayan Hornbill,highlights the importance of the NWPPNP for the species'conservation,and provides strong evidence for re-assessing the global population size.

Avian Species Diversity and Population Dynamics at Eastern Al Dabasin Bridge, Khartoum, Sudan

Birds play a vital role in monitoring ecosystem health and biodiversity because they are relatively easy to observe and have been extensively studied. However, ongoing threats such as habitat destruction, fragmentation, and environmental changes have significantly impacted their populations and distribution patterns. This study focuses on assess the variety and relative richness of bird species at Eastern Al Dabasin Bridge in Khartoum, Sudan, as well as evaluating their current conservation status furthermore examines human activities impacting bird populations. Monthly surveys, conducted using the Point Counts method across wet and dry seasons between 7:00 a.m. and 10:00 a.m., documented species counts and locations. Identification utilized visual characteristics such as size, color, and vocalizations. A total of 3708 birds, representing 80 species from 17 orders and 41 families, were recorded. The most frequently observed species were the House Sparrow, Spur-winged Lapwing, Greater Blue-eared Starling, Laughing Dove, and Black Kite. Bird abundance peaked in June and December, with richness affected by seasonal and environmental conditions. All species observed were classified as Least Concern, underscoring the importance of conservation and sustainable management to protect local biodiversity and safeguard the long-term viability of bird populations in the area, it is essential to adopt a holistic approach to environmental management. This should include measures for pollution reduction, habitat rehabilitation, and the promotion of community education on the importance of conservation.