Flow Distance Research Articles

Gone with the wind: Negative genetic and progeny fitness consequences of habitat fragmentation in the wind pollinated dioecious tree Brosimum alicastrum.

Habitat fragmentation negatively affects population size and mating patterns that directly impact progeny fitness and genetic diversity; however, little is known about the effects of habitat fragmentation on dioecious, wind pollinated trees. We assessed the effects of habitat fragmentation on population sex ratios, genetic diversity, gene flow, mating patterns and early progeny vigor in the tropical dioecious tree, Brosimum alicastrum. We conducted our study in three continuous and three fragmented forest sites in a Mexican tropical dry forest. We used eight microsatellite loci to characterize the genetic diversity, gene flow via pollen distances and mean relatedness of progeny. We compared early progeny vigor parameters of seedlings growing under greenhouse conditions. Sex ratios did not deviate from 1:1 between habitat conditions, except for one population in a fragmented habitat, which was female biased. The genetic diversity of adult trees and their offspring was similar in both habitat conditions. Pollen gene flow distances were similar across habitat types; however, paternity correlations were greater in fragmented than in continuous habitats. Germination rates did not differ between habitat conditions; however, progeny from fragmented habitats produced fewer leaves and had a lower foliar area, total height, and total dry biomass than progeny from continuous habitats. Changes in mating patterns, because of habitat fragmentation, have negative effects on early progeny vigor. We conclude that negative habitat fragmentation effects on mating patterns and early progeny vigor may be a serious threat to the long-term persistence of tropical dioecious trees. This article is protected by copyright. All rights reserved.

Paper-based sensors for visual detection of alkaline phosphatase and alpha-fetoprotein via the distance readout

The development of paper-based sensors with the distance readout is particularly attractive for the point-of-care testing (POCT) of biomarkers. Herein, we report a paper-based sensor that can convert the viscosity change caused by the hydrogel degradation into the variance of water flow distance on the paper. The detection of alkaline phosphatase (ALP) and alpha-fetoprotein (AFP) is demonstrated as examples. Copper alginate (Cu-Alg) hydrogel can be formed when mixing the aqueous solutions of Cu2+ and alginate. The introduction of pyrophosphate ion (PPi) induces the gel-sol transition due to the high affinity between Cu2+ and PPi. However, in the presence of ALP, the gel-sol transition is prevented due to the hydrolysis of PPi by ALP. In these processes, the viscosity changes of the hydrogels are translated into the differences of the flow distances on the pH test papers. In addition, the tilt of the papers can increase the accuracy of detection. The detection of AFP is also fulfilled via the construction of the paper-based immunosensor using the ALP-linked AFP detection antibody. The developed paper-based sensors show excellent performance for the quantitative detection of biomarkers in real samples with remarkable selectivity. Overall, this convenient method has great potential in POCT applications.

Investigation of the effect of matrix-interface formed with silane-based coupling agents on physico-chemical behavior and flow distance of dental composites

Flowable restorative composites that are unique for clinical application performances, both in mechanical and physico-chemical properties as well as flowability, were developed through the modification of A200 and M8000 silica particle surfaces with various silane-based coupling agents. The presence of the coupling agent used in particle surface modification for matrix-particle interface formation was specified with thermogravimetric analysis and Brunauer–Emmett–Teller surface area analysis while the bonding was specified with Fourier Transform Infrared and X-Ray Photoelectron spectroscopy analysis. Flexural strength, compressive strength and water sorption, which are considered to be important tests in this field, were conducted and studied. Flowability was examined keeping clinical application performances in mind. The increase in silanization activity that is dependent on the length and volume of the active unit belonging to the coupling agent decided by the dispersion of modified silica particles in the matrix is linearly related to the active unit quantity of the coupling agent. Active unit quantity, which is also linearly related to the flowability of the composite, affects mechanical and physico-chemical properties of the composites. The flow distances and rates of the produced composites are in the range of 0.63–3.43 cm and 0.11–0.57 mm/s, respectively. different composites in the flowable composites class, which are generally adopted in the area of dental composites, have been produced. The created interface changed the rheologies of the composites, resulting in a change in flow distances and rates, and composites exhibiting similar flow behavior as commercial flowable composites were obtained.

Influence of powder size on the moldability and sintered properties of irregular iron-based feedstock used in low-pressure powder injection molding

Initially used for shaping irregular ceramic powders, manufacturing metallic parts via low-pressure powder injection molding (LPIM) from irregular powders has received very little attention. This study investigates the processability of irregular powders for fabricating high-density and low-cost metallic parts using the LPIM process. Three irregular iron-based powder lots were mixed with a low-viscosity binder, injected, debound, and sintered to evaluate their molding and sintering performances via viscosity measurements, real-scale injections, metallographic analysis, and tensile tests. The results revealed that feedstocks formulated from fine and coarse powders exhibit good moldability, predicted by their moldability indexes and validated by spiral flow distances. Furthermore, the feedstock formulated with the finer powder (i.e., 1250 mesh providing a powder particle size <10 μm) produced a homogeneous microstructure along with a low content of oxygen impurities, leading to the highest sintered relative density of ∼90%, an ultimate tensile strength of ∼225 MPa, and an elongation at break of ∼24%. These results confirm that the cost-effective irregular iron powders present a promising alternative to fabricating metallic parts via low-pressure powder injection molding compared to their relatively high-cost spherical powder counterparts (i.e., carbonyl iron powder).

The formation and proximity mechanism of population flow networks under multiple traffic in China

Population flow within a specific spatial range can promote social and economic reaggregation and diffusion. However, few empirical studies have paid close attention to population flow networks (PFNs) under different traffic. Tencent migration data were used to analyse the spatial patterns and aims to identify how proximity affects PFNs among 338 Chinese cities in 2018. The results indicated that the weighted average distance of population flow by highways and railways are 252.39 km and 566.16 km, showed restriction by distance decay in space. However, the weighted average distance of population flow by aviation was 1282.71 km, was less affected by geospatial constraints. PFNs involving highways, railways, and aviation display core-periphery, corridor, and hub-spoke structures, respectively. China's PFNs forms a diamond structure under multiple traffic, with Beijing, Shanghai, Shenzhen, Guangzhou, Chongqing, and Chengdu as the vertices. Negative binomial regression models were used to determine how proximities affect PFNs under multiple traffic. The estimated coefficients for geographical proximity, institutional proximity, and cultural proximity were significantly positive at the 1 % level. The influence of climate proximity on the PFNs may be complex, with a positive impact on PFNs on highways and railways but a negative impact on PFNs involving aviation.

Absent Right Coronary Artery in an Active Young Female

Absent Right Coronary Artery in an Active Young Female

Defining the Extent of Mine-Influenced Groundwater in a Mineralized and Agricultural Area Using Multiple Lines of Evidence

Mine-influenced groundwater (MIW) at a former copper mine site has affected an alluvial aquifer that also contains groundwater with solutes characteristic of natural mineralization and agricultural activities. Many of the solutes are common to at least two of three potential sources, and some solutes (e.g., sulfate and uranium) are common to all three. This precludes the conventional use of one, or several, characteristic solutes to identify the extent of MIW. So, we used five independent lines of evidence (LOE) to define the extent of MIW in the alluvial aquifer. The five LOE are multivariate statistical analysis of an extensive groundwater analyte suite, groundwater sulfur isotope (δ34SSO4) data, probabilistic calculations of groundwater velocity and flow distance, isotopic (3H/3He) estimates of groundwater age, and extent of nitrate in groundwater originating from agricultural activities.

The development of a paper-based distance sensor for the detection of Pb2+ assisted with the target-responsive DNA hydrogel

Due to the serious risks of lead pollution to human health, it plays a great role in constructing a simple, inexpensive, portable, and user-friendly strategy for Pb2+ detection in environmental samples. Herein, a paper-based distance sensor is developed to detect Pb2+ assisted with the target-responsive DNA hydrogel. Pb2+ can activate DNAzyme to cleave its substrate strand, which results in the hydrolysis of the DNA hydrogel. The released water molecules trapped in the hydrogel can flow along the patterned pH paper due to the capillary force. The water flow distance (WFD) is significantly influenced by the amount of water released from the collapsed DNA hydrogel triggered by the addition of various Pb2+ concentrations. In this way, Pb2+ can be quantitatively detected without using specialized instruments and labeled molecules, and the limit of detection (LOD) of Pb2+ is 3.0 nM. Additionally, the Pb2+ sensor works well in lake water and tap water. Overall, this simple, inexpensive, portable, and user-friendly method is very promising for quantitative and in-field detection of Pb2+ with excellent sensitivity and selectivity.

Roadmap for the exposé of radiation flows (Xflows) experiment on NIF.

The goal of the Xflows experimental campaign is to study the radiation flow on the National Ignition Facility (NIF) reproducing the sensitivity of the temperature (±8eV, ±23μm) and density (±11 mg/cc) measurements of the COAX platform [Johns et al., High Energy Density Phys. 39, 100939 (2021); Fryer et al., High Energy Density Phys. 35, 100738 (2020); and Coffing et al., Phys. Plasmas 29, 083302 (2022)]. This new platform will enable future astrophysical experiments involving supernova shock breakout, such as Radishock (Johns et al., Laboratory for Laser Energetics Annual Report 338, 2020) on OMEGA-60 [Boehly et al., Rev. Sci. Instrum. 66, 508 (1995)], and stochastic media (such as XFOL on OMEGA). Greater energy and larger physical scale on NIF [Moses et al., Eur. Phys. J. D 44, 215 (2007)] will enable a greater travel distance of radiation flow, higher density, and more manufacturable foams and enable exploration of a greater range of radiation behavior than achievable in the prior OMEGA experiments. This publication will describe the baseline configuration for the Xflows experimental campaign and the roadmap to achieve its primary objectives.

Long-term degradation of high molar mass poly(ethylene oxide) in a turbulent pilot-scale pipe flow

The long-term drag reduction capability of poly(ethylene oxide) with a nominal molar weight of Mw=4×106 g/mol dissolved in water was investigated in a pilot-scale pipe flow device (inner diameter of test section 26 mm) at a Reynolds number of 105. A total loss of the initially high (75%) drag reduction capability was observed over a flow distance of several ∼10 km while the molar weight of the polymer was still Mw∼5×105 g/mol. Mechanical degradation in the turbulent flow as well as ageing of the polymer dissolved in water caused this loss in drag reduction capability. A simple ansatz of two independent, statistical polymer chain scission mechanisms was used to describe the polymer degradation empirically using a modified Brostow model. This empirical description was applied successfully and suggested that the polymer exhibited at least 15 cleavage points for mechanical degradation.

Effect of thermo-velocity barriers on fish: influence of water temperature, flow velocity and body size on the volitional swimming capacity of northern straight-mouth nase (Pseudochondrostoma duriense).

Water temperature and flow velocity directly affect the fish swimming capacity, and thus, both variables influence the fish passage through river barriers. Nonetheless, their effects are usually disregarded in fishway engineering and management. This study aims to evaluate the volitional swimming capacity of the northern straight-mouth nase (Pseudochondrostoma duriense), considering the possible effects of water temperature, flow velocity and body size. For this, the maximum distance, swim speed and fatigue time (FT) were studied in an outdoor open-channel flume in the Duero River (Burgos, Spain) against three nominal velocities (1.5, 2.5 and 3m s-1 ) and temperatures (5.5, 13.5 and 18.5°C), also including the changes between swimming modes (prolonged and sprint). Results showed that a nase of 20.8cm mean fork length can develop a median swim speed that exceeds 20.7BL s-1 (4.31 m s-1 ) during a median time of 3.4s in sprint mode, or 12.2BL s-1 (2.55 m s-1 ) for 23.7s in prolonged mode under the warmest scenario. During prolonged swimming mode, fish were able to reach further distances in warmer water conditions for all situations, due to a greater swimming speed and FT, whereas during sprint mode, warmer conditions increased the swim speed maintaining the FT. In conclusion, the studied temperature range and flow velocity range influence fish swimming performance, endurance and distance travelled, although with some differences depending on the swimming mode. The provided information goes a step forward in the definition of real fish swimming capacities, and in turn, will contribute to establish clear passage criteria for thermo-velocity barriers, allowing the calculation of the proportion of fish able to pass a barrier under different working scenarios, as well designing of the optimized solutions to improve the fish passage through river barriers.

Long runout distance of a block breccia density flow along a half-graben axis: latest Jurassic rift climax in East Greenland

A basinally isolated breccia–pebbly sandstone couplet occurs in the axial part of the latest Jurassic rift-climax half-graben in Wollaston Forland, East Greenland. Synrift breccias are otherwise restricted to a narrow zone along the scarp of the basin-margin Dombjerg Fault. Towards the north the Dombjerg Fault sidesteps en echelon towards the east where it continues in the Thomsen Land Fault. The breccia part of the couplet was transported by a noncohesive debris flow and the pebbly sandstone by a high-density turbidity flow. The couplet is located about 15 km east of the Dombjerg scarp and flowed southwards along the half-graben axis. It is interpreted to have been derived from the southern end of the Thomsen Land Fault. This gives a runout distance of at least 25 km. Other isolated breccias have been reported towards the south along the half-graben axis, giving a runout distance of up to 40 km along the roughly horizontal half-graben axis. The angularity of the clasts is remarkable and reflects derivation directly from the fault scarp during a single catastrophic event. The occurrence of breccias thus cannot be taken as evidence of short transport and deposition at the foot of a scarp or steep slope.

Towards techno-economics of green hydrogen as a primary combustion fuel for recreational vehicle vapor absorption refrigeration system

The drive towards the integration of hydrogen in the global primary energy mix to achieve a carbon–neutral and sustainable society requires both minor and major technological modifications in current energy systems. In this study, the viability of green hydrogen as a combustion fuel and its economics have been investigated for an absorption–desorption-based cooling system. Specially designed burners have been retrofitted with the portable ammonia-water-based cooling system (cooling area: 1.4 ft3). Furthermore, the effect of hydrogen flow and the distance from the burner has been investigated and optimized. The system has been compared with both electrical resistive heating using a 12 V DC power supply and propane gas. An increase in hydrogen flow rate leads to high cooling rates. Furthermore, the reduction in the distance between flame and heating surface improves the heat transfer rate. The system running on hydrogen exhibited highest performance compared to both electricity and propane at optimum flow rate and distance. The optimum flow rate and distance was observed to be 29.2l/h and 2 cm respectively. System running on optimum hydrogen conditions consumed 77.37Wh energy with is 9.10% less compared system running on electric resistance heating and 29% less compared to system running on propane. In terms of carbon–neutral economics, 1 kg of hydrogen can potentially replace 3.28 kg of propane (costing around 3.60 to 4.30 USD). Whereas, 8–9 kg of CO2 reduction can be achieved per kg of hydrogen being used. The 3.30 to 4.30 USD/kg may be considered a competitive cost of green hydrogen in comparison to propane as a combustion fuel for the portable refrigeration sector. These results are the first time, highlighting the efficient use of hydrogen in space cooling.

Alterations in Coronary Resistance Artery Network Geometry in Diabetes and the Role of Tenascin C.

Geometrical alterations in the coronary resistance artery network and the potential involvement of Tenascin C (TNC) extracellular matrix protein were investigated in diabetic and control mice. Diabetes was induced by streptozotocin (STZ) injections (n = 7-11 animals in each group) in Tenascin C KO (TNC KO) mice and their Wild type (A/J) littermates. After 16-18 weeks the heart was removed and the whole subsurface network of the left coronary artery was prepared (down to branches of 40 m outer diameter), in situ pressure-perfused and studied using video-microscopy. Outer and inner diameters, wall thicknesses and bifurcation angles were measured on whole network pictures reconstructed into collages at 1.7 m pixel resolutions. Diabetes induced abnormal morphological alterations including trifurcations, sharp bends of larger branches, and branches directed retrogradely (p 0.001 by the 2 test). Networks of TNC KO mice tended to form early divisions producing parallelly running larger branches (p 0.001 by the 2 probe). Networks of coronary resistance arteries were substantially more abundant in 100-180 m components, appearing in 2-5 mm flow distance from orifice in diabetes. This was accompanied by thickening of the wall of larger arterioles ( 220 m) and thinning of the wall of smaller (100-140 m) arterioles (p 0.001). Blood flow should cover larger distances in diabetic networks, but interestingly STZ-induced diabetes did not generate further geometrical changes in TNC KO mice. Diabetes promotes hypertrophic and hypotrophic vascular remodeling and induces vasculogenesis at well defined, specific positions of the coronary vasculature. TNC plays a pivotal role in the formation of coronary network geometry, and TNC deletion causes parallel fragmentation preventing diabetes-induced abnormal vascular morphologies.

The influence of particle size on the spread distance and angle of friction of granular materials

To produce a hazard map and thus provide mitigation measures against natural catastrophic events such as landslides, avalanches, and debris flows, it is necessary to determine the spread distance of such flows. There is a well-documented relationship between the angle of friction and the debris flow volume, allowing one to determine the possible distance a debris flow can travel. However, the effect of mean particle size (d50) and the sorting coefficient (Sc) on the final spread distance (Df) has received mere attention. In this study, a mini conical-shaped mould was used to measure the final spread distance (Df) and angle of friction (αf) for various dry granular material samples both in air and in water. Experimental results indicated that a granular material sample with a smaller d50 travel a longer distance compared to a sample with a higher d50. However, a sample with a smaller d50 results in a smaller angle of friction than the one with a higher d50. Conversely, a well-sorted sample has a smaller spread distance and larger angle of friction. Results also indicated that the spread distance in air is slightly larger and the angle of friction is slightly smaller than in water.

A Study on the Comparative Analysis of the FLO-2D Model According to Debris Flow Sediment Amount

It is very important to predict the extent of the damage in order to reduce or prevent damage by the debris flow. In the Republic of Korea, various methods are used to understand the characteristics and to estimate the occurrence of the debris flow in an undamaged area, such as simulating disasters using the estimation of debris flow sediment amount based on field survey data. In this study, the runout distance of debris flow was analyzed by using different methods for estimating the debris flow sediment amount, at Wondeok-eup, Samcheok-si, Gangwon-do, where debris flow occurred due to Typhoon Mitak in 2019. The simulation results of the damage area were compared with the actual damage area. The result showed that the simulations generally corresponded to the actual area of damage caused by the sedimentation of debris flow. However, the estimation of damage area varied according to the used method of calculating the debris flow sediment amount.

Proposal of Hazard Connectivity Index for debris flow disaster management

The concept of connectivity and its index have been widely discussed and applied to environmental studies such as ecology, hydrology, geomorphology and hydrosedimentology. Supposing that this concept is very useful also in disaster risk management, we define the hazard connectivity associated to debris flows as the connectivity degree between the debris flow occurrence (trajectory) and the point of interest (location of house, person, and so on). Based on this definition, the Hazard Connectivity Index (HCI) associated to debris flow is proposed as: HCI = L/(x+L), where x is the shortest distance between the debris flow trajectory and the point of interest; and L is the runout distance of the debris flow or just mass movement. The HCI value varies from 0 to 1, being that its higher value indicates larger hazard condition. The HCI application to one case study showed that it can be useful in the analysis of the debris flow related hazard.

Pilot study to explain runout distances of debris flow and immature debris flow considering depositing rate

In Japan, many debris flows and sediment-laden floods cause serious damage to human life and property. Effective measures require high-accuracy reproduction and prediction of runout distance (bed variation reach) via numerical simulations. One possible method to increase the accuracy of numerical simulation results involves reviewing the methods used to evaluate depositing rate for flows that contain many different sizes of sediments. This study performed experiments using an artificial channel and high-speed cameras to identify parameters that govern depositing rate. The channel implemented exhibited a change in slope point; thus, the slope of the upper reach differed from the slope of the lower reach. The experiments showed that the equation representing depositing rate is closely related to flow velocity. Additionally, the equation of depositing rate can be determined if other parameters are consistently considered.

Analysing the Impacts of Parking Price Policies with the Introduction of Connected and Automated Vehicles

It is known that parking prices can affect multiple characteristics such as traffic flow, delays, and congestion. Connected and autonomous vehicles (CAVs) do not need drivers and may return to the origin, if necessary, avoiding parking fees. However, if the destination area is not near the origin, it may not be economically viable to return. Hence, in the present study, four scenarios were tested to find the optimal parking strategy: (i) enter and park inside area (ii) enter, drop off and return to the origin (iii) enter, drop off and return to outside parking and (iv) enter and drive around. Different parking prices were used to determine the suitable option. The ‘Balanced’ scenario with multiple parking choices was found to be better compared to other scenarios, where the flow and travel distance were moderately (-19 and -26.3%) affected. Emissions were reduced significantly with CAVs.

Noise pollution of the road network of the city by road transport

The article is devoted to the analysis of noise pollution of a residential area by road traffic. It is noted that car noise is a great danger to human health, especially in large cities and industrial centers. Field studies of the noise characteristics of traffic flows in busy, dangerous sections of the road network of a large city have been carried out. It is shown that the level of car noise exceeds the maximum permissible sound level for any measured value of the flow intensity and distance from the road up to 35 m. The dependence of noise on the parameters of traffic flows is studied, analytical dependences are obtained, and correlation and regression analyzes are carried out. Measures have been proposed to reduce the level of automobile noise in busy sections of the road network of a large city.