Wide Belt Research Articles

Channel trajectories control deep‐water stratigraphic architecture

AbstractInterpretation of deep‐water channel deposits is challenging because the spatial arrangement of their constituent lithologies is highly variable. This variability is often thought to be a signature of complex interactions between controlling boundary conditions and processes. A three‐dimensional forward stratigraphic model of a sinuous meandering channel is used to explore the production of channelised deep‐water stratigraphy. This model highlights three stages of stratigraphic evolution for channel belts: (1) an initial phase of rapid growth in mean belt width and variability in belt width driven by increasing channel sinuosity; (2) a subsequent phase of reduced belt‐width growth rate because of cutoff processes; and (3) a mature phase during which repeated bend lifecycles act to produce a statistically stable channel‐belt width. When a trajectory defining the vertical movement of a channel over time is added to the model, commonly recognised patterns of deep‐water channel‐belt stratigraphy are produced. These results demonstrate how forward stratigraphic models provide insights into processes governing the evolution of deep‐water stratigraphy that elude interpretations of static outcrops and seismic images of subsurface examples.

A “no-drift” runaway pile-up of pebbles in protoplanetary disks

Context. Forming planetesimals from pebbles is a major challenge in our current understanding of planet formation. In a protoplanetary disk, pebbles drift inward near the disk midplane via gas drag and they may enter a zone of reduced turbulence (dead zone). In this context, we identified that the backreaction of the drag of pebbles onto the gas could lead to a runaway pile-up of pebbles, the so-called no-drift mechanism for the formation of planetesimals. Aims. We improve upon the previous study of planetesimal formation from accumulating pebbles via the no-drift mechanism by investigating the nature and characteristics of the resultant planetesimal belt. Methods. We performed 1D diffusion-advection simulations of drifting pebbles in the outer region of a modeled dead zone by including a pebble-gas backreaction to the radial drift of pebbles and including planetesimal formation via the streaming instability. We independently considered the parameters that regulate gas accretion (αacc) and vertical stirring of pebbles in the disk midplane (αmid). In this study, the pebble-to-gas mass flux (Fp/g) was fixed as a parameter. Results. We find that, for a constant Fp/g, after the criteria of the no-drift mechanism are satisfied, planetesimals initially form within a narrow ring whose width expands as accumulating pebbles radially diffuse over time. The system finally reaches a steady-state where the width of the planetesimal belt no longer changes, followed by a continuous formation of planetesimals. A non-negligible total mass of planetesimals (more than one Earth mass) is formed via the no-drift mechanism for a disk having Fp/g ≳ 0.1 for more than ~10–100 kyr with nominal parameters: a gas mass flux of ≳10−8 M⊙ yr−1, τs ≃ 0.01−0.1, αmid ≲ 10−4, and αacc ≃ 10−3−10−2 at r ≲ 10 au, where r, τs, αmid, and αacc are the heliocentric distance, the Stokes number, and the parameters in a dead zone controlling the efficiencies of vertical turbulent diffusion of pebbles (i.e., scale height of pebbles) and gas accretion of the α-disk (i.e., gas surface density), respectively.

Conditions to Preserve the Sedimentary Record of Channel Planforms in Temperate Rivers of the Northern Hemisphere

AbstractWe aim to identify conditions that influence the preservation of a complete record of channel planforms in the topmost layer of floodplains, prior to the maintenance in the rock record. We have tested a hypothesis that a successive decrease of stream power and channel belt width are necessary to preserve the record of channel planforms in the topmost floodplain layer over 103 to 104‐year time scales. A literature review was conducted for rivers of the temperate zone of the Northern Hemisphere. Stream power, valley, and channel belt widths, paleodischarges, sediment grain‐size, and age of paleochannels were used to identify four groups of rivers with preservation potential ranging from tens of thousands years to annual time scales. The decrease in stream power followed by sustained low stream power, and successive decrease of channel belt width were identified in rivers preserving a 103 to 104‐year record of channel planforms. River valleys with the record of at least two generations of paleochannels, and valley width/channel belt width ratios between 6 and 12, potentially preserve fluvial records over 103 to 104‐year time scales. We analyzed unusually well‐preserved records of channel planforms from the Obra and Sió Rivers (central Europe). A determination of trends in changes of stream power and channel belt widths based on an extensive set of geophysical, geological data, and sediment dating from earlier studies, confirmed the tested hypothesis. The proposed framework can be extended by fluvial records preserved by large, and coastal rivers, with the potential to include ancient fluvial records.

A marble statue from Nis of an early Byzantine imperial woman

The paper presents and analyses the only known Early Byzantine marble life-size statue of a secular woman in the Byzantine empire, which was discovered in the Nis Fortress in 1931. She is dressed in an unpretentious but dignified stola with a wide belt under her breasts, necklace around her neck and cloak on her back, status symbols by which prominent persons were recognisable throughout the Middle Ages. Being aware of the fact that it is not possible to be certain of her identity, we have enough reasons to suggest that this is a statue of an unknown imperial woman (the empress or a woman from the imperial environment) who, like emperors, was presented with the cloak. As such, it was a common part of the city forum of Naisos, as well as a worthy successor to the composition of Tetrarchs and the statue of Constantine the Great. Stylistic analysis indicates the still living ancient heritage united with Christian concepts of the dress design and its resemblance to the dresses of women from the Empress Theodora?s entourage date it back to the 6th century and Justinian?s epoch.

Женские шейно-нагрудные украшения финно-угорских и тюркских народов Урало-Поволжья как источник реконструкции археологического костюма

The costume of the ancient population of the Volga-Ural region cannot be studied without reference to ethnographic materials of such modern Finno-Permian and Turkic ethnic groups as Mordvins, Chuvash, Mari, Udmurts, Tatars and Bashkirs. The paper deals with the systematization of women’s neck and breast adornments of the listed peoples and represents a major step towards the attri-bution, interpretation and reconstruction of similar archaeological artifacts. A general classification of traditional neck and breast adornments was carried out. Seven independent categories were dis-tinguished: single-row or multi-row simple neck and chest necklaces, neck «collars» and neck-breast necklaces with a narrow («ribbons») or wide («breastplates») organic base, shoulder belts and chest buckles. Particular attention was given to the ethnographic concept of «breast¬plate», its genesis and evolution in the Volga-Ural region. The general term includes such items of predominantly female costume as a chest band, adornments and a cloth breastplate with similar functions of the previous products. But the origin of such items may be different. Archaeological analogues of breastplates should be interpreted as adornments. All types of «breastplates» were preserved by the Tatars and Bashkirs and partly by Finno-Ugrian ethnic groups (for example, Zakama Udmurts and Eastern Mari people). Variations in the types of «breastplates» among Finno-Ugric clothing of the Volga-Ural region can be explained by borrowing. But it is impossible to exclude the independent origin of such items.

Floodplain Sediment Storage Timescales of the Laterally Confined Meandering Powder River, USA

AbstractAs sediment is transported through river corridors, it typically spends more time in storage than transport, and as a result, sediment delivery timescales are controlled by the duration of storage. Present understanding of storage timescales is largely derived from models or from field studies covering relatively short (≤102 year) time spans. Here we quantify the storage time distribution for a 17 km length of Powder River in Montana, USA by determining the age distribution of eroded sediment. Our approach integrates surveyed cross‐sections, analysis of historical aerial imagery, aerial LiDAR, geomorphic mapping, and age control provided by optically stimulated luminescence (OSL) and dendrochronology. Sediment eroded by Powder River from 1998 to 2013 ranges from a few years to ∼5,000 years in age; ages are exponentially distributed (r2 = 0.78; Anderson‐Darling p value 0.003). Eroded sediment is derived from Powder River's meander belt (∼900 m wide), which is only 1.25 times its meander wavelength, a value reflecting valley confinement rather than free meandering. The mean storage time, 824 years (95% C.I. 610–1030 years), is similar to the time required to rework deposits of Powder River's meander belt based on an average meander migration rate of ∼1 m/yr, implying that storage time distributions of confined meandering rivers can be quantified from remotely sensed estimates of meander belt width and channel migration rates. Heavy‐tailed storage time distributions, frequently cited from physical and numerical modeling studies, may be restricted to unconfined meandering rivers.

Assessing the palaeohydrology of the lost Saraswati River in the Punjab-Haryana plains, Northwest India from satellite data

It has been suggested over a century ago that the Saraswati was a large river that flowed in the Sutlej-Yamuna interfluve, a region that is now devoid of any such large river system. This large river was commonly related to the Saraswati River described in the Rig-veda, and was correlated with the discovery of several Harappan sites in the region. Presently, there is only the ephemeral Ghaggar River that flows here with its limited discharge along the abandoned course of the ‘lost’ Saraswati. Also, it was hypothesised earlier that this region was drained by the waters from the drainage basins of both the glacier/monsoon-fed Sutlej and Yamuna rivers. It therefore stands to reason that this region should preserve evidence of the record of the past discharge variability that impacted this region prior to the major drainage reorganisation. This study is an attempt to reconstruct the palaeohydrology of the Saraswati River. We investigate the hypothesis, that the ancient Saraswati River used to carry a combined flow of the Sutlej, Ghaggar and Yamuna river catchments. To examine this important question, we use the channel belt width, catchment area and average annual discharge of different rivers presently flowing on Indus-Ganga-Brahmaputra plains in the Himalayan Foreland. We use these variables to establish the empirical scaling relationships between the channel belt width and average annual discharge to the catchment area. We observed rivers having a larger catchment usually carry a higher discharge and have a wider channel belt. Finally, we use these empirical scaling relationships to estimate the channel belt width and average annual discharge of the lost Saraswati River at the time when it possibly carried the combined flow of the Sutlej, Ghaggar, and Yamuna rivers catchments. We obtained the average annual discharge of the Saraswati River of an order of 3000 m3s−1 and channel belt width of about 11 km at the location downstream of the postulated confluence of the Sutlej and Yamuna rivers at Suratgarh.

Multi-Criteria ranking algorithm for high quality of products in high performance drilling Operation: A case study for considering the Wide-Web and Cryo treated drills

Among the most commonly used tools in the industrial business, high-speed steel (HSS) tools rank first. A large web thickness and cryogenic treatment were used to obtain the most significant improvements in machining quality with the HSS tool. The results of this study are presented in this publication. Being stiffer in nature than normal drills, they have always had the ability to drill straighter, deeper, and more exact hole diameters than standard drills. Furthermore, wide-web drills often allow for feed rates that are approximately 20% faster than standard drills, and the strength of a wide belt makes it the ideal tool for deep cuts in hard materials. On the basis of a multi-criteria classification technique, this study discusses how to select the appropriate process parameter to obtain the highest possible level of drilling quality. These findings concern the optimization of drilling settings utilising a strategy to get the lowest possible deviation from cylindricity, surface roughness (Ra), roundness error, and burr. Cylindricity, surface roughness (Ra), roundness error, and burr are all considered in this study. Mistreating the L9 orthogonal die on the CNC milling machine resulted in a series of drilling trials, which were then recorded. The traces were made on the ZE41 block, which was produced by gravity die casting, with a cutting tool of a 4 mm diameter treated HSS drill, which was employed during experimental work in dry cutting circumstances to make the traces. The Combinative Distance-based ASsessment (CODAS) and ANOVA were used to determine the main spindle speed, feed rate, web thickness, Pont Angle, and Cryogenic Treated Drill Tools that had an impact on the response were determined. It is investigated whether information factors have a main or cooperative effect on normal reactions.

Optimizing mangrove conservation efforts with improved understanding of phytosociology-ecology synergy in Sri Lanka

The study aimed to understand the forest structure and ecological factors influencing mangrove distribution in eight mangrove forests across three climatic zones in Sri Lanka. We studied mangrove diversity and vegetation structure with 10m wide belt transects laid of different lengths (n=96) across the land-water gradient. Mangroves along the transect were identified, enumerated, and measured diameter at breast height (DBH). Subsurface water samples were taken in the adjoining lagoon/estuary to assess the environmental parameters (n=144), and water quality parameters were measured. Site-dependent spatial changes in the community structure were depicted through cluster analysis (CA). The forest survey revealed a heterogeneous mixture of 20 true mangrove species across the sites dominated by Avicennia, Rhizophora, and Sonneratia spp. Among the several environmental parameters analyzed by the distance-based redundancy ordination analysis (dbRDA), salinity, dissolved oxygen, and precipitation were found to be controlling factors in mangrove community structure. In addition, discriminant analysis confirmed the presence of ecological-phytosociological influence on mangrove assemblages identified through CA. The significant structural parameters tree density, and taxonomic diversity when tested using the canonical analysis of principal coordinates (CAP), altered the species abundance across the sites surveyed. The results suggest that there is a strong linkage between phytosociology and ecology with the mangrove forest distribution and this relationship needs to be considered wisely to fortify successful restoration practices.

Research on the horizontal reduction effect of urban roadside green belt on atmospheric particulate matter in a semi-arid area

In this study, the horizontal abatement effects of green belts on atmospheric particulate matter at different horizontal distances and plant community structures were investigated in urban roadside green belts in semi-arid areas.We collected mass concentrations of six types of atmospheric particulate matter (PM) per unit time of PM0.3, PM0.5, PM1.0, PM2.5, PM5.0, and PM10 and various meteorological indices, to compare the horizontal reduction efficiency of different distances and plant community structures on different particle sizes, and to establish a support vector machine model. The results showed that 1) the horizontal abatement efficiency of green belts was different for six particle sizes, while the horizontal abatement rate strengthened as the particle size increased. The abatement rate was significantly correlated with microclimatic factors such as temperature and humidity, but less correlated with wind speed. 2) The horizontal abatement rate of roadside green belts on atmospheric particulate matter varies with the increase of horizontal distance in a "single-peak" or "double-peak" pattern, with the best abatement effect of green belts on each particle size at a horizontal distance of 45m. Among the four types of plant community structures, the strongest abatement ability was in the arbor-shrub-herb structure. 3) The correctly tuned prediction model, based on Support Vector Machines, resulted in better horizontal abatement ability of green belts on atmospheric PM. The prediction results showed that the average horizontal abatement rate has the best abatement effect at 45–55 m, peaked at 50 m, and formed stagnant dust at 65 m. In the design of urban road green spaces in semi-arid areas, to achieve the best dust retention effect, the green belt width should be ≥40 m and it is desirable to choose arbor-shrub-herb structures. This study provides a design basis and theoretical support for urban road green space planning in semi-arid areas.

The magnitude of the transverse contraction of the Middle Tien Shan along the “Karabuk” profile at the late orogenic stage

The detailed geological profile “Karabuk” constructed in recent years, crossing the triad of alpine structures “Naryn Depression - Baibichetoo Uplift - Atbashi Depression [[CHECK_DOUBLEQUOT_ENT]] in the central part of Tien Shan, provides new material for studying the style and parameters of deformations at the late phase of the Indian - Eurasian plate collision. Using original methodological techniques and in accordance with the basic principles of balanced sections method, the horizontal deformation of the rock complex of the Cenozoic sedimentary cover (a meridional reduction in the width of the orogenic belt) was determined, starting from the end of the Neogene. Variations in the thickness of the cover layers determined during the research were taken into account. The presented tectonic reconstruction demonstrates the structure of a single Naryn-Atbashi sedimentary basin before the intense deformations at the late orogenic phase. It is significant, that the magnitude of deformations on individual segments of the profile differs markedly. The cover of the Atbashi depression is more deformed, its width has decreased by 6 km (about 17%) in this section, while the borders of the wider Naryn depression have converged by only 3.7 km (8%). The total South-North contraction of the NBA system measured by us during the Cenozoic is about 10 km (12% of its original width). The values of the contraction from south to north (the horizontal component of the deformation) obtained by us compared with the values given by other researchers.

Investigating the Causes and Impacts of Convective Aggregation in a High Resolution Atmospheric GCM

AbstractA ∼50 km resolution atmospheric general circulation model (GCM) is used to investigate the impact of radiative interactions on spatial organization of convection, the model's mean state, and extreme precipitation events in the presence of realistic boundary conditions. Mechanism‐denial experiments are performed in which synoptic‐scale feedbacks between radiation and dynamics are suppressed by overwriting the model‐generated atmospheric radiative cooling rates with its monthly varying climatological values. When synoptic‐scale radiative interactions are disabled, the annual mean circulation and precipitation remain almost unchanged, however tropical convection becomes less aggregated, with an increase in cloud fraction and relative humidity in the free troposphere but a decrease in both variables in the boundary layer. Changes in cloud fraction and relative humidity in the boundary layer exhibit more sensitivity to the presence of radiative interactions than variations in the degree of aggregation. The less aggregated state is associated with a decrease in the frequency of extreme precipitation events, coincident with a decrease in the dynamical contribution to the magnitude of extreme precipitation. At regional scales, the spatial contrast in radiative cooling between dry and moist regions diminishes when radiative interactions are suppressed, reducing the upgradient transport of energy, degree of aggregation, and frequency of extreme precipitation events. However, the mean width of the tropical rain belt remains almost unaffected when radiative interactions are disabled. These results offer insights into how radiation‐circulation coupling affects the spatial organization of convection, distributions of clouds and humidity, and weather extremes.

Did the Boreal Realm extend into the equatorial region? New paleomagnetic evidence from the Tuva–Mongol and Amuria blocks

Fossil organisms of the Boreal Realm in the Tuva–Mongol Block (TMB) and Amuria Block (AMB) are commonly thought to have lived at mid to high latitudes during the Carboniferous Period; however, reliable paleomagnetic constraints have not been available previously to test this hypothesis. Here we report newly obtained combined paleomagnetic and geochronological results from the Upper Mississippian Gunbayan Formation in the AMB and the Lower Pennsylvanian Altan-Ovoo Formation in the TMB. Zircon U–Pb dating of tuff beds from the Gunbayan and Altan-Ovoo formations yield ages of 331.0 ± 2.7 and 315.5 ± 2.4 Ma, respectively. A total of 263 paleomagnetic specimens underwent stepwise thermal demagnetization. After removing the viscous remanent magnetizations of the recent geomagnetic field, stable high-temperature components (HTCs), carried by magnetite, were successfully acquired from 240 specimens. The HTCs of the Gunbayan Formation passed a fold test and a reversal test, and those of the Altan-Ovoo Formation passed a fold test, suggesting that they represent primary remanence magnetizations. We used the elongation/inclination method to test and correct for all the HTC directions of the clastic rocks of the studied formations. Their corresponding paleomagnetic poles are 46.0°N/320.0°E (A=952.0°) at ca. 330 Ma for the AMB and 43.5°N/355.9°E (A=952.9°) at ca. 315 Ma for the TMB. The updated paleomagnetic database indicates with certainty that both the TMB and the AMB were located in northern hemisphere low-latitude regions and close to the equator at ca. 330 Ma, suggesting that the Boreal Realm might have extended into the equatorial region at the onset of the large ice age of the Carboniferous. The paleobiogeographic characteristics and distribution of climate-sensitive lithologies indicate that this realm occupied a wide northern temperate belt during 330–315 Ma.

A Sensor for Measuring the Tension of Cotton Belt

In this paper, the design process of a strain gauge sensor for measuring the tension of cotton belt is presented. The elastic body of the sensor is a single cantilever beam, and a light metal pulley is installed at the end of the beam. When the cotton belt passes through the pulley, the pulley will be subjected to pressure and cause the deformation of the beam. After processing, the electrical signals output by the resistance strain gauges pasted on the elastic body can be converted into the tension of the cotton belt. In this study, first of all, through mechanical calculation, it is determined that there is an approximate linear relationship between the change of the tension of the cotton belt and the output signal of the bridge of the elastomer. Then, through the finite element method, the relationship between the strain of the elastomer and the pressure on the guide wheel is analyzed, and the specific size of the elastomer and the appropriate position of the resistance strain gauge are determined. Finally, the temperature compensation and broken line correction are carried out. The practice shows that the measuring range of the sensor can reach 30N, the sensitivity can reach 2.35mV/V, the maximum linear speed of the 6 mm wide cotton belt passing through the guide wheel of the sensor can reach 2m/s, the working temperature range of the sensor is -30~60°C, and the comprehensive measurement error is less than 0.5%F.S.

The formation of wide exoKuiper belts from migrating dust traps

ABSTRACT The question of what determines the width of Kuiper belt analogues (exoKuiper belts) is an open one. If solved, this understanding would provide valuable insights into the architecture, dynamics, and formation of exoplanetary systems. Recent observations by ALMA have revealed an apparent paradox in this field, the presence of radially narrow belts in protoplanetary discs that are likely the birthplaces of planetesimals, and exoKuiper belts nearly four times as wide in mature systems. If the parent planetesimals of this type of debris disc indeed form in these narrow protoplanetary rings via streaming instability where dust is trapped, we propose that this width dichotomy could naturally arise if these dust traps form planetesimals whilst migrating radially, e.g. as caused by a migrating planet. Using the dust evolution software dustpy, we find that if the initial protoplanetary disc and trap conditions favour planetesimal formation, dust can still effectively accumulate and form planetesimals as the trap moves. This leads to a positive correlation between the inward radial speed and final planetesimal belt width, forming belts up to ∼100au over 10 Myr of evolution. We show that although planetesimal formation is most efficient in low-viscosity (α = 10−4) discs with steep dust traps to trigger the streaming instability, the large widths of most observed planetesimal belts constrain α to values ≥4 × 10−4 at tens of au, otherwise the traps cannot migrate far enough. Additionally, the large spread in the widths and radii of exoKuiper belts could be due to different trap migration speeds (or protoplanetary disc lifetimes) and different starting locations, respectively. Our work serves as a first step to link exoKuiper belts and rings in protoplanetary discs.

Loose Material Filling in the Loading Trough Profile of the Belt Conveyor

The paper presents a mathematical expression of the sizes of the transverse and longitudinal cross-section surfaces and of the volume of the loose material spread on the surface of the conveyor belt before the transverse partition of the belt conveyor, inclination angle of which exceeds the limit transport angle permitted for the belt conveyor of a classic design. Volume and geometric shape of the lose material; transported in the trough (two-roller bench) loading profile; are impacted by the mechanical characteristics of the transported material, width of the conveyor belt, inclination angle of the side rollers, height of the transverse ribs and especially inclination angle of the conveyor. The maximal cross-section surface of the lose material filling at the conveyor with a smooth belt can be (for conveyor belts modified based on the shape of the trough) expressed as the sum of the cap cross-section surface and the surface of the bottom part of the belt filling. The paper describes the jacket curve of the of the cap cross-section using a parabola equation, and the surface curve of the bottom part of the belt filling using a line equation. The size of the cross-section surface of the belt filling along the longitudinal plane of the conveyor belt is defined as the difference between the inclination angle of the conveyor and the discharge angle of the transported material.

Optimization of the cross section of a novel rail running conveyor system

The throughput of a belt conveyor system is the primary design parameter when considering a new installation, determined by the cross-section of the material on the belt, coupled with the belt speed. Optimizing this area not only improves efficiency, but also minimizes capital costs through the optimal selection of equipment. Whilst speed-related optimization has seen considerable attention, the cross-sectional area has largely been neglected due to existing design constraints of the system. Conventional belt conveyors typically utilize a 3-idler troughing configuration, which forms a trapezoidal cross-section with a parabolic surcharge. The rigidity of this support directly limits the geometry of the cross-section that may be considered. A new conveyor system developed at the University of Newcastle supports the conveyor belt by a rail-based carriage, with no relative movement between the belt and carriage. This configuration allows the cross-section of the belt to be freely optimized in order to maximize the material throughput for a given belt width, or alternatively to minimize the belt width for a given throughput. This article utilizes the calculus of variations to optimize the form of this cross section, and demonstrates that an increase in throughput of up to 30% is possible, compared to troughed installations.

Geoecological parameters indicate discrepancies between potential and actual forest area in the forest-steppe of Central Mongolia

BackgroundForest distribution in the forest-steppe of Mongolia depends on relief, permafrost, and climate, and is highly sensitive to climate change and anthropogenic disturbance. Forest fires and logging decreased the forest area in the forest-steppe of Mongolia. The intention of this study was to identify the geoecological parameters that control forest distribution and living-tree biomass in this semi-arid environment. Based on these parameters, we aimed to delineate the area that forest might potentially occupy and to analyse the spatial patterns of actual and potential tree biomass.MethodsWe used a combination of various geographic methods in conjunction with statistical analyses to identify the key parameters controlling forest distribution. In several field campaigns, we mapped tree biomass and ecological parameters in a study area within the Tarvagatai Nuruu National Park (central Mongolia). Forest areas, topographic parameters and vegetation indices were obtained from remote sensing data. Significant correlations between forest distribution and living-tree biomass on one hand, and topographic parameters, climate data, and environmental conditions on the other hand, were used to delineate the area of potential forest distribution and to estimate total living-tree biomass for this area.ResultsPresence of forest on slopes was controlled by the factors elevation, aspect, slope, mean annual precipitation, and mean growing-season temperature. Combining these factors allowed for estimation of potential forest area but was less suitable for tree-biomass delineation. No significant differences in mean living-tree biomass existed between sites exposed to different local conditions with respect to forest fire, exploitation, and soil properties. Tree biomass was reduced at forest edges (defined as 30 m wide belt), in small fragmented and in large forest stands. Tree biomass in the study area was 20 × 109 g (1,086 km2 forest area), whereas the potential tree biomass would reach up to 65 × 109 g (> 3168 km2).ConclusionsThe obtained projection suggests that the potential forest area and tree biomass under the present climatic and geoecological conditions is three times that of the present forest area and biomass. Forest fires, which mostly affected large forest stands in the upper mountains, destroyed 43% of the forest area and 45% of the living-tree biomass in the study area over the period 1986–2017.

Belt width optimization for tire durability enhancement

Tire burst is one of the hot issues in automobile market. Based on the tire burst problem of all-steel radial tire, the shear strain and strain energy density at the end of the belt layer are analyzed to extend the tire durability. A multi-objective optimization model was established by finite element analysis, and the function constraints conditions were set. The optimization scheme was determined using differential evolution (DE) method. The finite element simulation and the durability test of tire specimen show that tire performance has greatly improved after the optimization. The results show that the combination of the finite element analysis technique and the multi-objective optimization method can effectively reduce a lot of labor, material, and financial resources in the structural optimization of mechanical products.

Parametric Optimization of Belt Conveyors by Energy Efficiency Criterion

Purpose. The purpose of this work is to substantiate the optimal values of the belt conveyor parameters, at which the specific energy consumption for the cargo transportation takes on the lowest value. Methodology. The substantiation of the optimal values of the belt conveyor parameters was carried out by minimizing the function of specific energy consumption, which represents the energy consumption for the transportation of a cargo weighing 1 kg at a distance of 1 m. In the course of research, the drive force was determined using the contour bypass meth-od. In this case, the specific loads from the transported cargo, belt and roller supports were presented as functions of the belt width. To establish the optimal values of the conveyor productivity and belt speed, the belt width was presented as a function of these values, taking into account the physical and mechanical properties of the transported cargo, the design features of the roller supports and the belt angle. Findings. I obtained the dependences of specific energy consumption on the design parameters of the conveyor. Their analysis made it possible to identify the opti-mal values of the belt width, conveyor productivity, belt speed, and the optimal ratio of the last two values for dif-ferent types of transported cargo. It is noted that the results obtained can be supplemented by carrying out calcula-tions according to the formula given in this work. It has been established that the optimal value of the belt width depends only on the belt angle and on the coefficients that determine the energy losses, in particular the movement resistance coefficient of the belt; the influence of the specified coefficient increases with an increase in the belt angle. In addition, the optimal value of the belt width does not depend on the conveyor length, its productivity and belt speed. Originality. The dependences of the specific energy consumption on the design parameters of the belt conveyor were obtained, which made it possible to establish the optimal values of the belt width and the ratio of the conveyor productivity to the belt speed. Practical value. The results of this work can be used in the design of energy-efficient belt conveyors, which are characterized by the lowest specific energy consumption for cargo transportation.