Molluscs community as a keystone group for assessing the impact of urban sprawl at intertidal ecosystems

Mollusc communities are getting endangered in the aftermath of urban sprawl because artificial structures do not surrogate natural substrates. In this study, we compared the diversity, community and trophic arrangements of molluscs among different models of artificial substrate and their adjacent natural rock, to detect relationships between some abiotic variables and the mollusc communities. Complexity, chemical composition and age were tested as potential drivers of the community. Diversity, community and trophic structure differed between natural and artificial substrates. Complexity at the scale of cm was detected as the most important factor driving the community structure. In addition, a chemical composition based on silica and/or scarce calcium carbonates seems to be relevant for molluscs, as well as for the secondary substrate where they inhabit. However, age did not seem to be a driving factor. Among the different artificial structures, macroscale complexity was detected as the main factor diverging a drastically poor community at seawall from other artificial structures. In this context, macro and microscale complexity, chemical composition and mineral type are variables to consider in future designs of artificial substrates.

Forecast-exploration model of gold deposits of the Toupugol-Khanmeishor ore cluster as a basis for identification of promising areas for geological exploration within the Malyi Ural volcano-plutonic belt in the Polar Urals

A forecast-exploration model of gold deposits of the Toupugol-Khanmeishor ore cluster was developed, which made it possible to recommend geological exploration within other promising areas of the Malyi Ural volcano-plutonic belt (VPB) in the Polar Urals. The studies have demonstrated that the Manyukuyu and Kokpela potential ore clusters of the Tan’yu-Lagorta complex ore district in the southern Malyi Ural VPB represent the most promising targets for the further prospecting for lode gold mineralization assigned to various structural-compositional subtypes of the gold-sulfide-quartz mineral type.

PSI-2 Spices in Free-choice Mineral Offer Gain Advantages to Cattle on Tallgrass Native Range and Promise as Fly Control

This study aims to evaluate effectiveness of two operational management systems for steer gains and fly control. The first strategy evaluated was pasture burn date of March (MAR) or April (APR). The second management strategy was fly control through feeding free-choice mineral with spices (SPICE) or without spices (CON). Eight pastures (n = 281 steers; initial weight 277.7 ± 25.2 kg) were used in a 2 x 2 factorial treatment structure. Steers were weighed individually, randomly assigned to treatment, and grazed for 85 days. Weekly 33% of steers per pasture were photographed and fly numbers counted. ADG was impacted by both burn date and mineral type (P = 0.01). Cattle on the APR-SPICE treatment had a greater ADG than MAR-SPICE and APR-CON with MAR-CON intermediate. Cattle on SPICE gained 4.5 kg (P = 0.12) more than cattle consuming CON mineral. Flies per steer were impacted by burn x mineral x week (P < 0.001). In general, APR-SPICE steers had a greater number of flies weeks 8, 10, and 11 (P < 0.05), corresponding to a time when mineral intake averaged 72% of the formulated intake. The MAR-SPICE steers consumed on average the formulated amount of mineral and through the entire grazing period had lower number of flies than APR-SPICE steers (P < 0.05). The second largest ADG observed with the MAR-CON treatment may be attributed to lower fly numbers as this treatment had one extra week below economic threshold for horn flies. These results are somewhat inconclusive on pasture burn date, but show that the addition of spices to a free-choice complete mineral shows promise as a cost-effective method to increase gains in stocker steers on tallgrass native range. As a fly control method, the spices utilized in this study may be effective if intake is at formulated level.

Clays are not created equal – effects of clay mineral type on soil hydraulic and mechanical properties

<p>Clay minerals dominate the soil colloidal fraction and often carry the largest specific surface area – a property that controls various soil hydraulic and mechanical properties (SHMPs; e.g. water retention, permeability, and internal friction). Differences in microscale structure among clay mineral types in tropical and temperate regions affect the specific surface area and result in higher permeability and internal friction angle values for tropical soils with inactive kaolinite clay minerals. Presently, the soil clay size fraction used to parameterize SHMPs with pedotransfer functions (PTFs) ignores clay mineral type, leading to inconsistent parameter representation. In this study, we present new PTFs informed by clay minerals, enabling enhanced estimation of friction angle and saturated hydraulic conductivity. To capture higher conductivity and lower air entry values in tropical soils, we developed a hierarchical packing model and validated this new PTF approach using literature data from various tropical regions. We leveraged recent global maps of clay minerals to demonstrate that a strong climatic and spatial segregation of active and inactive clays enable spatially resolved consideration of clay mineral type in SHMP estimation. We applied these clay-informed PTFs to improve SHMP representation regionally with implications for a wide range of hydrological and geomechanical Earth surface processes.</p>

The heat exchangers tubes mineral type effect on the refrigeration system performance using different lengths of the capillary tube

An experimental study is conducted to show the influence of the tubes material type of the heat exchanger on the refrigeration system performance. The system is operated by using R134a as a working fluid, 2 mm internal diameter, and different lengths of capillary tubes which were 120, 135, and 150 cm. The experimental results showed that when increasing the refrigerant mass flowrates led to reducing each of the performance coefficient COP, number of transfer unit NTU and evaporator effectiveness ε. However, the highest improvement had appeared for each parameter COP, NTU, and ε which were 21%, 113.38%, and 59.42% respectively at a capillary tube length of 120 cm and [Formula: see text] = 3.19 g/s compared to the length of capillary tube 150 cm. Besides, it was found an increase in [Formula: see text] with the incrementing in the capillary tube length from 120 cm to 150 cm. The biggest percentage of compression power was 23% at the capillary tube length of 150 cm compared to others at [Formula: see text] = 3.71 g/s. Finally, the experimental results of COP and [Formula: see text] were validated by comparing them with other publications.