Maximum Carrying Capacity Research Articles

Short-Term Combined Exercise Improves Inflammatory Profile in the Retina of Obese Mice.

Excess of adipose tissue increases the concentration of proinflammatory cytokines, triggering a subclinical inflammatory condition. This inflammatory profile contributes to retina damage, which can lead to retinal dysfunction and reduced vision. Regularly practicing both aerobic and strength exercises is well known for promoting anti-inflammatory effects on different organs in the peripheral and central regions. However, the effects of combined physical exercise (CPE; strength + aerobic) on the inflammatory process in the retina tissue are not yet known. This study aimed to investigate the effects of CPE on the inflammatory profile of the retina in obese mice. Swiss mice were distributed into control, sedentary obese, and trained obese groups. The trained obese group was subjected to short-term CPE, 1 h/day, for 7 days. The CPE was composed of aerobic and strength exercises in the same exercise session. The strength exercise protocol consisted of 10 climbing series, with 12 ± 1 dynamic climbing movements at 70% of the maximum voluntary carrying capacity (MVCC), and the aerobic exercise protocol consisted of 30 min of treadmill running, with an intensity of 75% of the exhaust velocity. Subsequently, the retina was excised and analyzed by Western blot. Obese animals presented impairment on glucose homeostasis and elevated levels of proinflammatory proteins in the serum and retina; however, CPE was effective in reversing these parameters, independently of changes in body adiposity. Therefore, for the first time, we have shown that short-term CPE can be an important strategy to treat an inflammatory profile in the retina.

Application of the Extended Gompertz Model in Analyzing Insurance Growth

The South African insurance sector is experiencing a positive growth as the nation is on high quality economic growth and development. However, there is little attention with regards to research on the growth analysis, hence the researchers aim to bridge the gap by analyzing the growth using a mathematically based approach. To verify the wide spread phenomenon behind insurance growth an extended Gompertz model (EGM) which is a member of the unified Richards family was used. The quantitative approach by means of functional limits, the cumulative distribution approach, initial value problem (IVP) and the qualitative derivative approach were used to fully analyze the model. We managed to derive a cumulative function was derived which can be used to estimate the number of insurance growth indicators.
 The maximum carrying capacity of an insurance industry was estimated using the IVP which in our case is time dependent hence does not concur with other Gompertz related works. Using both the qualitative and derivative approach, a growth function which produced the same pattern with the original Gompertz curve with K(t) as the asymptotically stable and non-constant growth limit were deduced. Hence we can conclude that the growth of insurance sectors does follow a sigmoid shape with non-constant maturity levels. Lastly, we performed a statistical analysis of the nexus between insurance sector growth and economic development using GDP and insurance indicators (net premiums) data. From the statistical analysis done the results showed a positive relationship between the two. This showed that, insurance sector indeed plays a significant role towards economic development and as such their growth patterns should be well attended.

Novations in creation and ensuring the competitiveness of BELAZ quarry machinery

The development tasks of OJSC “BELAZ” – Management Company of Holding “BELAZ-HOLDING”, are defined, which consist in using and introducing the latest achievements in the field of technical sciences and innovative technologies created on their basis into the design and production processes of mining equipment; development of new competitive products and promising sales markets, diversification of exports. Together with scientific organizations, studies have been carried out that have allowed us to develop new and improve existing methodological approaches to solving urgent problems in all problematic areas of creating modern mining dump trucks especially and in excess of extra heavy lifting capacity. OJSC “BELAZ” is the only manufacturer and supplier of dump trucks with a carrying capacity of 450–500 tons. As a result of research on the creation of such machines, the model of a short-base maneuverable dump truck with a rigid frame of a special design was first recommended, which reduces the center of gravity and loading height of a mining dump truck, designed according to the 4 × 4 scheme (two drive axles) with double axle busbar and the use of existing tires with a maximum carrying capacity of 104 tons. The proposed and comprehensively tested new layout solutions give reason to believe that the development of dump trucks with a carrying capacity of up to 600 tons is a reality when mastering the production of tires with a carrying capacity of more than 110 tons. А new generation of dump trucks with hydromechanical transmissions is designed; work is underway to create robotic complexes for the mining industry. Particular attention is paid to computerization, digitalization and environmental friendliness of mining equipment, ensuring the reliability of technology by creating and applying new structural materials and technologies for large parts and systems.

Deformation and cracking characteristics of ring-shaped granite with inclusion under diametrical compression

This paper presents the results of an experimental investigation on the deformation and cracking behaviors of ring-shaped granite specimens. Diametrical compression tests were conducted on ring-shaped granite specimens with inclusion and those without inclusion for comparison. The inclusion materials were of different strengths, stiffness, and sizes. Strain gauges (SGs) were amounted at the boundary of the hole to trace the strain evolutions, and digital image correlation (DIC) technique was used to identify the crack initiation and propagation process. The results indicated that the inclusion has a positive effect on the enhancement of the carrying capacity. The maximum carrying capacity of the specimen with low-strength inclusion decreases with increasing the inclusion diameter, while it first decreases and then increases when the inclusion diameter increases from 10 to 20 mm for the high-strength infilled specimens. The results of the strain evolutions analyzed by the SGs and DIC methods indicate that a lager hole diameter and a lower inclusion strength lead to a more intensive strain concentration around the hole. Due to the mismatch in the deformation at the rock–cement mortar interface, serious strain concentrations are induced, and hence leading to three types of failure, i.e., debonding between the interface, tensile crack in the granite, and tensile crack in the inclusion material.

Analyzing Hydrodynamic Energy Consumption to Predict Carrying Capacity Index

Summary Implementing efficient fluid-carrying capacity of drilled cuttings is an essential process for a good drilling program, either for a better rate of penetration (ROP) or a safer drilling operation. In this paper, I present a methodology that is based on the transfer function representation, which can be used to analyze the consumed fluid energy used in lifting the drilled cuttings in vertical wells to estimate the maximum carrying capacity index (CCI), which leads to performance at the desired ROP. The consumed hydrodynamic energy equation has been formulated using a second-order differential equation as a function of the drilling fluid, cuttings properties, and drilling operating parameters. Therefore, it allows an accurate quantitative monitoring of the fluid's CCI, which is the best alternative method to the currently empirical model. Moreover, it determines the perfect hydrodynamic energy required for any designed ROP to prevent excessive or poor hole-cleaning performance.

Research on Regional System Planning Method of Rural Habitat in Gully Regions of the Loess Plateau, under the Background of Rural Vitalization Strategy in China

Against the background of the Rural Vitalization Strategy in the gully regions of the Loess Plateau, large number of residents living in gullies move to tableland. On the one hand, this causes the disappearance of slope villages and gully villages; on the other hand, it increases ecological pressure on tableland, which was originally densely populated. The villages’ locations, the developing conditions, and the ecological carrying capacity of the surrounding villages have influence on the development direction of these villages and regional system planning. Through comparative analysis of different analysis methods for determining ecological carrying capacity, this paper takes the limiting factor analysis method as the main method and improves it according to the local conditions. Through the analysis of maximum ecological carrying capacity, current carrying capacity, and current population, we can determine which villages have the potential to support more immigrants and which ones should be integrated with others to improve the human settlement environment. At the same time, villages are graded so that the present and future human settlements’ environment can be further analyzed and predicted, which can be also adopted as an important guide for the local villages’ relocation and combination. Finally, we select a representative region to prove the general applicability of our planning method in the Loess Plateau.

Sustainable shellfish aquaculture in Saldanha Bay, South Africa

The carrying capacity for bivalve shellfish culture in Saldanha Bay, South Africa, was analysed through the application of the well-tested EcoWin ecological model, in order to simulate key ecosystem variables. The model was set up using: (i) oceanographic and water-quality data collected from Saldanha Bay, and (ii) culture-practice information provided by local shellfish farmers. EcoWin successfully reproduced key ecological processes, simulating an annual mean phytoplankton biomass of 7.5 µg Chl a l–1 and an annual harvested shellfish biomass of about 3 000 tonnes (t) y–1, in good agreement with reported yield. The maximum annual carrying capacity of Small Bay was estimated as 20 000 t live weight (LW) of oysters Crassostrea gigas, or alternatively 5 100 t LW of mussels Mytilus galloprovincialis, and for Big Bay as 100 000 t LW of oysters. Two production scenarios were investigated for Small Bay: a production of 4 000 t LW y–1 of mussels, and the most profitable scenario for oysters of 19 700 t LW y–1. The main conclusions of this work are: (i) in 2015–2016, both Small Bay and Big Bay were below their maximum production capacity; (ii) the current production of shellfish potentially removes 85% of the human nitrogen inputs; (iii) a maximum-production scenario in both Big Bay and Small Bay would result in phytoplankton depletion in the farmed area; (iv) increasing the production intensity in Big Bay would probably impact the existing cultures in Small Bay; and (v) the production in Small Bay could be increased, resulting in higher income for farmers.

Principle and Performance Analysis for Heterpolar Permanent Magnet Biased Radial Hybrid Magnetic Bearing

In order to solve the nonlinear problem and strong coupling of three-pole magnetic bearings, a heterpolar permanent magnet biased radial structure is proposed. Firstly, the structure and working principle of the heterpolar permanent magnet biased radial hybrid magnetic bearing are introduced, and the mathematical models of suspension forces are established by the equivalent magnetic circuit method. Secondly, in the case of the same volume and the same ampere-turn, the force-current characteristics and maximum carrying capacity of the couple-piece type three-pole structure and the heterpolar permanent magnet biased radial structure are obtained through theoretical analysis and 3D finite element method (FEM) analysis, respectively, and the data obtained are analyzed and compared. Finally, the theory analysis and experiment results show that compared with the couple-piece type three-pole structure, the nonlinearity among the suspension forces and the control currents of the heterpolar permanent magnet biased radial structure is obviously reduced, and the maximum bearing capacity of the heterpolar permanent magnet biased radial structure is increased by 29.4%, which proves the rationality of the radial heterpolar permanent magnet biased radial structure and parameters.

Design of a Paralleled SiC MOSFET Half-Bridge Unit With Distributed Arrangement of DC Capacitors

Discrete silicon carbide (SiC) mosfet s are usually connected in parallel to increase their current carrying capacity. However, unequal switching losses and unequal transient current overshoot can limit the maximum switching frequency and maximum current carrying capacity of the paralleled unit. In this article, a paralleled half-bridge unit is proposed to improve the transient current sharing performance, which is characterized by a distributed arrangement of dc capacitors. First, the main causes of the transient current imbalance in traditional power layout are analyzed theoretically for the first time. Then, the traditional power layout is optimized by the ANSYSEM cosimulation techniques to improve the transient current sharing performance. The layout of the gate driver is also optimized to reduce the transmission delay of the gate drive signal. The double pulse tests are carried out to verify the current sharing performance under normal and short-circuit operating conditions. Compared with traditional power layout, the difference in a transient current overshoot of the low-side paralleled SiC mosfet s is decreased significantly from 10.22% to 2.78% and the difference in switching losses is also reduced. A boost converter is constructed based on the paralleled half-bridge unit. A more uniform temperature distribution indicates the improved current sharing performance by optimizing the power layout.

Estimating the climatic capacity of food security in Henan Province, China under the future climate change scenarios

To explore the effects of future climate change on food production in Henan Province, the climate potential productivity and its change characteristics in Henan Province were calculated by agro-ecological zone (AEZ) model. This study was based on the production potential and climate resource carrying capacity of summer maize and winter wheat, combined with the observation data of 111 meteorological stations in Henan Province from 1961 to 2017 and the meteorological data under two emission scenarios of RCP4.5 and RCP8.5 in 2041-2080. With the grain demand index under different living standards, we analyzed climate carrying capacity and surplus space of Henan Pro-vince. The results showed that the average climatic potential productivity of maize was 18408.87 kg·hm-2 from 1961 to 2017, with high values in the middle and east, and low values in the west. Compared with the reference period (1981-2010), climatic potential productivity of maize under RCP4.5 and RCP8.5 decreased by 13.0% and 8.0% respectively, with the high value center shifting from the east to the southwest of Henan. The average climatic potential productivity of wheat was 10889.79 kg·hm-2, which was high in the middle region and low in the north. Compared with the reference period, climatic potential productivity of wheat under RCP4.5 and RCP8.5 decreased by 18.6% and 21.7%, respectively. Under the current condition of subsistence and well-off food demand, the maximum carrying capacity of climate resources respectively could support 252 million and 183 million people. In 2070s (2071-2080), the average supporting population of the maximum climate resource carrying capacity (Cmax) would decrease. Compared with the reference period, Cmax under the level of well-off and subsistence would decrease by 9.7% and 18.4% respectively in RCP4.5 scenario, and 7.7% and 16.6% respectively in RCP8.5 scenario. Under current climate condition, the relative surplus rate of climate resources in Henan Province ranged from -93.0% to 356.9%. Compared with the reference period, the relative residual rate of climate resources in the future would reduce nearly 40%.

Co-ingestion of carbohydrate and whey protein induces muscle strength and myofibrillar protein accretion without a requirement of satellite cell activation.

Muscle development is controlled by the balance between muscle protein synthesis and protein degradation. Protein supplementation has been widely known to enhance muscle protein synthesis, and carbohydrate supplementation may attenuate protein degradation. The purpose of this study was to compare the effects of whey protein plus carbohydrate (CP), whey protein (WP), and placebo (PLA) supplements on resistance training adaptations. Two-month old rats were trained by ladder climbing every 3 days for 8 weeks. PLA, WP, or CP was given immediately after each exercise session. Non-exercise rats were used as a sedentary control (SED). Total body composition was assessed and blood samples were collected before, middle, and end of training. The flexor hallucis longus (FHL) was excised 24 h after the last exercise session. Following training, maximal carrying capacity was significantly greater in CP than PLA and WP. This improved training performance in CP paralleled an increase in total muscle and myofibrillar protein content. Muscle and fiber cross sectional areas (CSA) were significantly increased by exercise training, with a concomitant increase in myonuclear domain. CP significantly elevated IGF-1 protein expression over SED, but there were no significant differences in myostatin, Pax7, MyoD, or myogenin across treatment groups. There was also no difference in the number of total nuclei in each fiber CSA among groups. Corticosterone levels were significantly elevated in PLA and WP over 8 weeks of training, whereas this change in corticosterone over time was not observed in the CP group. The results suggest that the greater improvement of maximal caring capacity for CP compared with PLA and WP was associated with a greater increase in myofibrillar protein content. Satellite cell activation did not appear to contribute to the observed gains in muscle hypertrophy and strength.

Safety analysis of the 100 kA HTS current lead for CFETR

Based on the Agreement of Institute of Plasma Physics Chinese Academy of Sciences (ASIPP) and Ministry of Science and Technology of China during the Thirteen Five-Years Plan (so called 13∙5 plan), a dedicated test facility of superconducting magnet for China Fusion Engineering Test Reactor (CFETR) will be constructed in Hefei, China. A pair of high temperature superconducting (HTS) current leads rated at 100 kA for the CFETR magnet test facility is being designed at ASIPP. Because magnetic energy stored in the toroidal field magnet is 134 Giga Joules which are 3 times higher than the ITER case, HTS current leads must work at nominal current without performance degradation during the HTS current lead quench. In order to verify the safety and reliability of HTS current lead, the analysis of static magnetic field is done by ANSYS iteration to predict the maximum current carrying capacity of HTS module. This paper also give the numerical calculation of loss of flow accident(LOFA) of HTS current lead and temperature margin analysis of HTS module. The analysis results indicate that the HTS module has a current carrying capacity of 165 kA without external field at 65 K and a current carrying capacity of 149 kA with external 30 mT vertical field at 65 K. The LOFA time is about 580 s and the burnout time is about 30 s, which is better than the requirement of the toroidal field coil fast discharge time of 24 s.

Experimental Study and Numerical Simulation on Failure Process of Reinforced Concrete Box Culvert

Culvert is an important part of roads whose healthy operation is related to the efficiency and safety of road transportation. Therefore, it is very important to evaluate the safety of culvert structure by load test. Four types of prefabricated reinforced concrete box culverts (integral BC, round hinged BC, flat seam BC, and mortise BC) were designed in this paper. By designing a scale model test, the sensor system was used to test the mechanical properties of BC, which included dial indicators, strain gauges, and a pressure sensor. The finite element analysis based on material nonlinearity and contact nonlinearity of round hinged BC and integral BC was carried out. After validating the finite element models, mechanical properties of reinforcement and concrete of BCs were analyzed. The experimental results show that the failure mode of BC was tensile failure of concrete at the bottom of top slab under bending action, and integral BC had the maximum carrying capacity. The contact behaviour of sliding and rotating at hinge joints caused the first principal tensile stress of concrete at the internal surface of the side wall below hinge joints.

Carrying Capacity of a Population Diffusing in a Heterogeneous Environment

The carrying capacity of the environment for a population is one of the key concepts in ecology and it is incorporated in the growth term of reaction-diffusion equations describing populations in space. Analysis of reaction-diffusion models of populations in heterogeneous space have shown that, when the maximum growth rate and carrying capacity in a logistic growth function vary in space, conditions exist for which the total population size at equilibrium (i) exceeds the total population that which would occur in the absence of diffusion and (ii) exceeds that which would occur if the system were homogeneous and the total carrying capacity, computed as the integral over the local carrying capacities, was the same in the heterogeneous and homogeneous cases. We review here work over the past few years that has explained these apparently counter-intuitive results in terms of the way input of energy or another limiting resource (e.g., a nutrient) varies across the system. We report on both mathematical analysis and laboratory experiments confirming that total population size in a heterogeneous system with diffusion can exceed that in the system without diffusion. We further report, however, that when the resource of the population in question is explicitly modeled as a coupled variable, as in a reaction-diffusion chemostat model rather than a model with logistic growth, the total population in the heterogeneous system with diffusion cannot exceed the total population size in the corresponding homogeneous system in which the total carrying capacities are the same.

A Preliminary Model for the Migration of Sulfide Droplets in a Magmatic Conduit and the Significance of Volatiles

Abstract A close relationship between Ni–Cu–(PGE) sulfide deposits and magmatic conduit systems has been widely accepted, but our present understanding still rests on empirical inductions that sulfide liquids are entrained during magma ascent and aggregated at hydrodynamic traps such as the opening of a conduit into a larger magma body. In this contribution, a preliminary quantitative model for the dynamics of mm-scale sulfide droplets in a vertical magmatic conduit is developed, examining such limiting parameters as the size, transport velocity and the magmas’ maximum carrying capacity for sulfide droplets. Addition of numerous dense sulfide droplets significantly reduces magma buoyancy and rapidly increases the bulk viscosity, and the resulting pressure gradient in the propagating conduit dyke restricts the maximum volume fraction of droplets that can be carried by ascending magma. For sulfide droplets alone, the maximum carrying capacity is low, but it will be improved dramatically by the addition of volatiles which reduces the density and viscosity of silicate melt. Potential volatile degassing during decompression further facilitates sulfide entrainment by reducing bulk magma density, and the formation of buoyant compound vapour-sulfide liquid bubble drops also greatly enhances the carrying capacity. The breakdown of compound drops by detachment of parts of the vapour bubble or sulfide droplet may occur at low pressure, which liberates sulfide liquids from rising compound drops, potentially to collect in traps in the conduit system. When sulfide-laden magma flows through a widening conduit, many droplets can be captured by the re-circulation flow just downstream of the expanding section, followed by sulfide liquid accumulation and enhanced chemical interaction via diffusive exchange with the recirculating magma, potentially resulting in an economic, high-tonnage ore body. We apply our models to the emplacement of sulfide-rich magmatic suspensions at Noril’sk and show that the disseminated mineralization in intrusions could have formed when magmas carrying re-suspended sulfide liquid entrained from pre-existing sulfide accumulations in the conduit system reached their limiting sulfide carrying capacity as dictated by buoyancy and were deflected into blind sills flanking the principal conduit for flood basalt volcanism.

A class of linear quadratic dynamic optimization problems with state dependent constraints

In this paper, we analyse a wide class of discrete time one-dimensional dynamic optimization problems—with strictly concave current payoffs and linear state dependent constraints on the control parameter as well as non-negativity constraint on the state variable and control. This model suits well economic problems like extraction of a renewable resource (e.g. a fishery or forest harvesting). The class of sub-problems considered encompasses a linear quadratic optimal control problem as well as models with maximal carrying capacity of the environment (saturation). This problem is also interesting from theoretical point of view—although it seems simple in its linear quadratic form, calculation of the optimal control is nontrivial because of constraints and the solutions has a complicated form. We consider both the infinite time horizon problem and its finite horizon truncations.

Traveling concentration pulses of bacteria in a generalized Keller–Segel model

We formulate a Markovian response theory for the tumble rate of a bacterium moving in a chemical field and use it in the Smoluchowski equation. Based on a multipole expansion for the one-particle distribution function and a reaction-diffusion equation for the chemoattractant field, we derive a polarization extended model, which also includes the recently discovered angle bias. In the adiabatic limit we recover a generalized Keller–Segel equation with diffusion and chemotactic coefficients that depend on the microscopic swimming parameters. Requiring the tumble rate to be positive, our model introduces an upper bound for the chemotactic drift velocity, which is no longer singular as in the original Keller–Segel model. Solving the Keller–Segel equations numerically, we identify traveling bacterial concentration pulses, for which we do not need a second, signaling chemical field nor a singular chemotactic drift velocity as demanded in earlier publications. We present an extensive study of the traveling pulses and demonstrate how their speeds, widths, and heights depend on the microscopic parameters. Most importantly, we discover a maximum number of bacteria that the pulse can sustain—the maximum carrying capacity. Finally, by tuning our parameters, we are able to match the experimental realization of the traveling bacterial pulse.

Evaluation of Technical Specifications of Gradation Course Base Subdrain Layer Structure on Road

Subdrain layer is a type of pavement that can reduce excess water from rainwater so that it can seep into the ground. The purpose of this research is to find the relationship between the optimal water velocity to pass through the base layer and maximum carrying capacity. Sieve analysis was carried out to obtain aggregate gradation variations by modifying the Bina Marga Standards 2010. There are 5 different types of gradations used based on the reduction in the percentage of filler specifications of 8%, 5%, 4%, 3%, and 0%. Calculation of fillers is used to find out the weight of aggregate each sieve size. In addition, the compaction test was carried out on ASTM D Modified 1883 - 87 to obtain optimum water content by using from the maximum dry density curve. The results of compaction the maximum dry density varies with the range 1,911-1,981 gr/cm3. The results of the maximum dry density show that the optimum water content varies between 9-10%. Next, the test sample is reused for CBR testing which aims to determine the carrying capacity of the test sample. Results tend to decrease when the filler is reduced. Obtained CBR test results is in the range of 62-74%. The sample is reused for the infiltration test to find the speed of the water capable of passing the test sample. Based on the results of the infiltration test, the constant infiltration rate varies from 3.143 to 6.750 mm/minute. The constant speed tends to increase when the percentage of filler decreases.

THE MANUFACTURE OF THE PROTOTYPE FIXED CRANE HARBOR AS THE ADDER DEVICE INSIGHT FOR CRANE OPERATOR NOVICE

Fixed cranes are tools used in the process of loading and unloading containers/materials from trucks and vice versa. Most of the young crane (beginners) operators in the port area are still unfamiliar in carrying out these tools, therefore the authors conduct research to make the fixedprototype crane that has functions and controls (including joystick) that allows the original device to remain valid. Insight enhancers in using real fixed cranes. The circuit built from Arduino Uno, DC motor (Gear Hoist and Gear Slewing), servo motor, and joystick as input for motion controllers from all systems. Fixed crane prototypes that have been made above are the best of the hoist system or the best slewing system todetermine the load that can be carried by the system. From the results of these calculations that the prototype fixed crane made has a maximum carrying capacity in terms of hoist and slewing of 90 grams

Minimizing Energy Loss by Coupling Optimization of Connection Topology and Cable Cross-Section in Offshore Wind Farm

The cable cross section of an offshore wind farm power system is conventionally determined on the basis of the maximum current carrying capacity. However, this criterion cannot be matched and optimized with connection topology, which may lead to a large overall resistance level in the topology, thereby causing severe energy loss. In this pursuit, the present work envisages the establishment of a coupling optimization method of connection topology and cable cross-section planning for the first time. Based on this method, the power system of a small discrete wind farm is optimized and its results are compared with the results of the traditional design methods. The results indicate that an optimal matching of connection topology and cable cross section can be achieved using the proposed method. Besides, the optimal topology obtained uses more branches, and the large cross-section cables are reasonably used on the large-current cable segments, thus dramatically reducing the energy loss and minimizing the total cost of the power system. The proposed method is very versatile and suitable for the optimization of power systems containing any number of wind turbines and substations. Moreover, it can be combined with any evolutionary algorithm.