Channel Pattern Research Articles

A Morphological Assessment On The Effects Of Embankments On Sediment Transport In Sandy Estuaries

Many large estuaries around the world are engineered to some degree for both flood protection of coastal communities and maintenance of economically vital shipping routes. Engineering challenges arise due to the highly dynamic morphological nature of estuaries, where the complex processes of sediment transport are driven by an interplay between the turbulent flows of rivers and tides. Naturally, the planforms of sandy estuaries have the tendency to converge landwards exponentially, where deviations from this shape provide alternating space and constrictions where tidal sandbars and channels form (Leuven et al., 2018-a; 2018-b). In the case of embankment by bank protection and dikes, such topographically forced channels can develop deep scour holes that endanger bank stability. Our objective is to study effects of channel and planform dynamics on scour depth variation near protected banks. To this end, we conducted scale experiments of estuaries with completely fixed banks in the tilting tidal flume the Metronome (Kleinhans et al., 2017). We study the effects of these fixed banks on the morphological behaviour of the channel pattern through one experiment, two repeat experiments, and a control without fixed banks. By collection of much longer timeseries than available in nature, we use the experiments to shed light on the topographic forcing and channel dynamics of these systems, and on the repeatability of Metronome experiments.

Integrating Microseismic Monitoring for Predicting Water Inrush Hazards in Coal Mines

The essence of roof water inrush in coal mines fundamentally stems from the development of water-bearing fracture zones, facilitating the intrusion of overlying aquifers and thereby leading to water hazard incidents. Monitoring rock-fracturing conditions through the analysis of microseismic data can, to a certain extent, facilitate the prediction and early warning of water hazards. The water inflow volume stands as the most characteristic type of data in mine water inrush accidents. Hence, we investigated the feasibility of predicting water inrush events through anomalies in microseismic data from the perspective of water inflow volume variations. The data collected from the microseismic monitoring system at the 208 working face were utilized to compute localization information and source parameters. Based on the hydrogeological conditions of the working face, the energy screening range and its calculation grid characteristics were determined, followed by the generation of kernel density cloud maps at different depths. By observing these microseismic kernel density cloud maps, probabilities of roof water-conducting channel formation and potential locations were inferred. Subsequently, based on the positions of these roof water-conducting channels on the planar domain, the extension depth and expansion direction of the water-conducting channels were determined. Utilizing microseismic monitoring data, a quantitative assessment of water inrush risk was conducted, thereby establishing a linkage between microseismic data and water (inrush) data, which are two indirectly related datasets. The height of microseismic events was directly proportional to the trend of water inflow in the working face. In contrast, the occurrence of water inflow events and microseismic events exhibited a specific lag effect, with microseismic events occurring prior to water inrush events. Abnormalities in microseismic monitoring data partially reflect changes in water-conducting channel patterns. When connected with coal seam damage zones, water inrush hazards may occur. Therefore, abnormalities in microseismic monitoring data can be regarded as one of the precursor signals indicating potential floor water inrushes in coal seams.

Analisis Efisiensi Pemasaran Jamur Tiram Putih (Pleurotus Ostreatus) di Kelurahan Air Rambai Kecamatan Curup Kabupaten Rejang

Research on marketing efficiency analysis of white oyster mushrooms (Pleurotus Ostreatus) in Air Rambai Village, Curup District, Rejang Lebong Regency aims to determine marketing channels, and analysis of marketing margins, as well as to determine whether the marketing efficiency of white oyster mushrooms in Air Rambai Village, Curup District.This research was conducted in March 2022 in Air Rambai Village, Curup District, Rejang Lebong Regency with farmers in Air Rambai Village. Data analysis used in this research is marketing channel analysis, marketing margin analysis, and marketing efficiency analysis. This data analysis was used for farmers and the 12 retailer respondents in Air Rambai Village, Curup District, Rejang Lebong Regency.Based on the results of data analysis, it can be seen that the marketing channel of white oyster mushrooms in Air Rambai Village, Curup District, Rejang Lebong Regency has two marketing channel patterns where the first marketing channel pattern sells white oyster mushrooms directly to end consumers, and the second marketing channel pattern is farmers sell to traders. retailers and then traders resell to final consumers. The marketing margin in the first marketing channel is Rp. 0, while in the second marketing channel it is Rp. 11,583. and the marketing efficiency of white oyster mushrooms in Air Rambai Village, Curup District, Rejang Lebong Regency is said to be efficient.

Fittability and mechanical properties of laser shock liquid warm microforming of AZ31B magnesium alloy foils with complex features

Difficult-to-form materials and complex mold characteristics have an important effect on the fittability and mechanical properties of microforming components. This study focuses on the fittability and mechanical properties of laser shock liquid warm microforming based on AZ31B magnesium alloy foils and a complex microcamera shell die. The characteristics of formed parts under varying temperatures and laser energies were discussed. Single-pulse and double-pulse forming experiments were conducted and compared. At 140 °C and 1260 mJ, double-pulse forming achieved a maximum depth of 184.5 μm, demonstrating near-perfect workpiece conformity to the die. In contrast, single-pulse forming did not achieve such results. This implies that double-pulse forming notably improves the fittability of workpieces and effectively mitigates springback. Finite element simulations corroborate the experimental findings. Moreover, simulation elucidates phenomena observed during experiments, including springback and crack formation. Additionally, the study delves into the microhardness, thickness distribution, and surface roughness of the formed parts. The results indicate that double-pulse forming yields workpieces with superior microhardness, reduced roughness, and a more uniform thickness distribution. Microstructural analysis reveals that grain refinement and substantial occurrence of twinning in the double-pulse forming process are the primary factors contributing to enhanced plasticity. The study also conducts a failure analysis of formed parts at room temperature, revealing the presence of numerous river patterns and cleavage planes, indicative of brittle fracture. Conversely, warm forming avoids fracture failure.

Analisis Efisiensi Saluran Pemasaran Jamur Tiram Putih (Studi Kasus di Desa Banjar Dewa Kecamatan Banjar Agung Kabupaten Tulang Bawang)

The aim of this study is to analyze the marketing channels for white oyster mushrooms and the efficiency of marketing channels for white oyster mushrooms in Banjar Dewa Village, Banjar Agung District, Tulang Bawang Regency. This type of study is descriptive qualitative research. The population of all farmers cultivating white oyster mushrooms is 14 people in Banjar Dewa Village, Banjar Agung District, Tulang Bawang Regency, with a sampling technique using Purposive Sampling with a sample of one farmer cultivating white oyster mushrooms with the criteria of producing the largest white oyster mushroom cultivation in the area. The method for collecting data in the following research is observation and interviews. The analysis technique in the following research uses marketing cost analysis, marketing margin, marketing profit, and marketing efficiency. The results of this research show that there are two marketing channel patterns for white oyster mushrooms, namely the first channel pattern, farmers sell white oyster mushrooms directly to end consumers, and the second channel pattern, farmers sell to retailers and then the retailers sell them back to end consumers. The marketing margin value in the first channel pattern is IDR 0, while marketing in the second channel pattern is IDR 11,000. The farmer's share value in the first channel pattern is 100%, the second channel pattern is 56%. The two marketing channels for white oyster mushrooms are said to be efficient in terms of marketing margin and farmer's share. The most efficient marketing channel for white oyster mushrooms is the first marketing channel with the lowest margin value and the highest farmer's share value.

3D vat photopolymerization printing of hydrophilic silicone-based microfluidic devices and the effect of cellulose nanocrystals as additives for improved printing accuracy

The lack of an ideal silicone-based ink material with optimal printability has significantly limited the potential to fabricate silicone-based microfluidic devices via 3D vat photopolymerization (VPP) printing. Oftentimes, photoabsorbers are incorporated into the ink material for better control of the photocuring depth in order to avoid excessive curing of unwanted parts. However, the search for a suitable photoabsorber without staining the ink material remains challenging due to the need to retain the clear interface in the final printed product. Herein, we present the fabrication of highly precise and transparent microfluidic devices using hydrophilic silicone-based ink via 3D VPP printing upon photocuring depth adjustment with cellulose nanocrystals (CNC). With the optimal CNC content, the ink material demonstrates enhanced printing accuracy with highly precise replication of channel patterns consisting of near zero deviation in width dimension down to 100 µm. Moreover, the addition of optimal CNC content exhibits no distinct final color and has no negative impact on the pre-gel viscosity and the gel point of the developed ink material. Moving on, the printed devices exhibit excellent fluid manipulation with various solvents for up to 24 hours, with incubation temperature up to 100ºC for 5 hours, and with a continuous flow rate up to 20 mL/min. The sustainable hydrophilicity, good organic solvent resistance, and excellent biocompatibility properties of the printed material further eliminate the need for additional surface modification to suit its application with either organic solvents or biological cells. To the best of our knowledge, the approach to tuning the photocuring depth of ink material with CNC is not widely reported. Besides, the successful fabrication of a highly detailed, neutral-colored, and highly functional hydrophilic silicone-based microfluidic device via 3D VPP printing upon the incorporation of CNC introduces a new avenue in terms of printing material and fabrication method for the mass production of microfluidic devices.

Depositional Facies and Sequence Stratigraphy of Kodiak Butte, Western Delta of Jezero Crater, Mars

AbstractHigh‐resolution 2D and 3D data remotely acquired by SuperCam's Remote Micro‐Imager and Mastcam‐Z aboard the Perseverance rover enabled us to characterize the stratigraphic architecture and sedimentary record of the Kodiak butte, an isolated remnant of the western delta fan of Jezero crater. Using these data, we build up on previous interpretations of the butte interpreted as a prograding Gilbert‐type deltaic series. We characterize three individual stratigraphic Units 0 to 2 on the eastern and northern faces of the butte. Each Unit displays the same vertical succession of prodeltaic/lacustrine bottomsets, delta slope toesets and foresets, and fluvially influenced topsets of a deltaic plain with a braided river pattern, shown by 11 individual sedimentary facies. We infer that these individual Units record the formation of three distinct deltaic mouth bars successively across time and space. For the first time on another planet than Earth, we are able to construct a precise sequence stratigraphic framework to highlight lake‐level fluctuations at the time the Kodiak butte was emplaced, during the latest stages of deltaic activity. We identify four hydrogeological cycles indicated by alternating rises and falls of the lake‐level on the order of 5–10 m. These were most probably linked to climatic events and variations controlling lake water inputs in probable relation to an astronomical control.

Flood dynamics on the upper Letaba River, South Africa, deduced from luminescence dating

ABSTRACT The Letaba River is one of several east-flowing rivers in the semiarid region of northeast South Africa. There is strong seasonality of river discharge and patterns of geomorphic behaviour along bedrock- and sediment-dominated reaches in these rivers, and in response to extreme seasonal flood events. This paper presents new luminescence ages on sediment samples from five sites in upper (headwater) reaches of the Letaba River catchment outside of Kruger National Park, South Africa, combined with evidence from reach-scale geomorphology and sediment sample analysis. River reaches are mainly mixed bedrock-alluvial with a patchwork of poorly sorted coarse sand bars overlying an abraded extended bedrock channel system. Luminescence ages from river sediment deposits (n = 13) cluster around three time periods of the last 400 years, 500–1100 BP, and 1400 BP. This suggests different reworked populations are present, which are a result of the partial bleaching of quartz grains and, thus, a mixed luminescence signal as flood-transported sediments are progressively moved from one depositional sink to another. This pattern of luminescence ages is quite different to lowland river systems in the same region where ages on the whole are significantly younger. Flood processes and dynamics in headwater reaches of semiarid rivers are often not considered but can yield a better understanding of system sensitivity to climate and event forcing.

Thermoelectric performance analysis of the novel direct-expansion photovoltaic thermal heat pump/power heat pipe compound cycle system in summer

Photovoltaic thermal heat pump technology has outstanding cogeneration ability by utilizing renewable energy to be accepted as a decarbonization pathway in the residential sector. However, existing photovoltaic thermal heat pumps consume higher energy under better external heat source conditions. To address this problem, a novel direct-expansion photovoltaic thermal heat pump/power heat pipe compound cycle system for heating and power generation as well as refrigeration, whose core equipment was a photovoltaic thermal module with straggled honeycomb fluid channel pattern on the serpentine arrangement, was proposed, manufactured, and studied with the method of experiment. The thermoelectric performance was compared between the heat pump and power heat pipe cycle modes, investigated under typical weather conditions, and discussed in contrast to the literature. The results showed that the average photoelectric conversion efficiency and coefficient of photothermal performance of the PVT modules, as well as COP of the novel system were 10.6%, 51.0%, and 6.19, respectively, at the average ambient temperature of 27.0 °C, average solar radiation intensity of 581 W/m2 and water temperature of 18.3–55.6 °C. And daily average COPs of the novel system under sunny, cloudy, and overcast conditions were 15.12, 7.40, and 3.17, respectively. The conclusion drawn from the experimental results is that the COP of the novel system was 10.0%–60.0% higher than that in the literature under similar outdoor conditions. The payback period of the additional cost of the novel system compared with the existing direct-expansion photovoltaic thermal heat pump was within 2.5 years. The novel system represents a practical response to the need to achieve total decarbonization of the residential sector.

Fluvial Morphology in Different Permafrost Environments—A Review

This review presents a synthesis of the interaction between the hydro-morphological processes on interfluves and channels within fluvial catchments in permafrost regions. Both in modern and ancient permafrost catchments, this integrated landscape is quite diverse because of a variegated extent of frozen ground, density of vegetation cover, snow thickness, and other local factors. Moreover, temporal changes in environmental conditions are expressed in the morphological evolution of catchments. Channel patterns vary between single- and different multi-channel forms while the interfluves show a high diversity ranging from complete stability to intense denudation by surface runoff. It appears that braided channels, despite their high energy, were only significant during short intervals of peak discharge and transported only limited amounts of eroded sediment, while other channel patterns required more subdued annual discharge variability. Further, denudational processes on interfluves were a specific characteristic of landscape evolution during subsequent ice ages, especially in conditions of snow-rich and poorly vegetated, seasonal frost, or discontinuous permafrost resulting in the formation of extended planforms (cryopediments). In contrast, interfluves appeared to be rather stable on continuously frozen soils.

The Guangya submarine fan in the South China Sea: A distinctive channelized slope-through fan

Submarine fans play a crucial role in understanding deep-sea sedimentary processes, establishing source-to-sink linkages, and identifying deep-water hydrocarbon reservoirs. Various types of submarine fans have been documented. Here we present findings on the Guangya submarine fan in the Southwest subbasin (SWSB) of the South China Sea (SCS), by analyzing multibeam bathymetric and two-dimensional multichannel seismic data. Bathymetric data reveal that the Guangya fan, covering an area of ~22,500 km2, comprises seven leveed channels, leading to a large composite lobe off the channel mouths. Different from typical submarine fans, the Guangya fan exhibits an elongated shape, extending longitudinally from the shelf edge through the slope to the abyssal plain, while laterally confined within a trough-like morphology in the southwestern tip of the SWSB and beyond. Lacking a typical feeding canyon, the fan appears to be self-fed by the leveed channels that serve as the primary depositional element. In contrast to the radial channel pattern in typical fans, the channels within the Guangya fan form a unique braid to dendritic pattern, genetically linked to channel merging and intersecting effects. Long wavelength and low wave height cyclic steps are identified, highlighting the occurrence of energetic supercritical turbidity currents. Seismic stratigraphic analysis shows that the Guangya fan primarily consists of high-amplitude reflections, indicating its coarser-grained or sandy turbidite-dominated nature. The fan has been evolved since the Pliocene, and mainly comprises depositional elements including channel fills, levees, lobes, and mass transport deposits. The specific tectonic context at the convergence of the conjugate margins, bounding the funnel-shaped SWSB, significantly influences the development of the Guangya fan. The Guangya fan could be originated from a shelf-edge staging area predominantly fed by the Mekong River during sea-level lowstands.

Independent and dynamic manipulation of surface waves radiation for quadruplex polarization channels enabled by programmable coding metasurface.

Flexible manipulation of surface waves (SWs) radiation has been continuously intriguing enormous interests of researchers due to its promising application prospects, and metasurfaces exhibit unparalleled capability to efficiently control SWs radiation. However, existing schemes still suffer from the bottlenecks of single radiation channel and immutable radiation pattern, which are difficult to satisfy the requirements of high-integration intelligent metadevices. Herein, an ingenious strategy of the SWs radiation metadevice is proposed to independently and dynamically manipulate SWs directional radiation in four polarization channels. The waveguide port and the guided wave structure are designed to excite and propagate the desired SWs, and the programmable coding metasurface can independently convert SWs into x-polarized radiation waves, y-polarized radiation waves, left-handed circular polarized radiation waves and right-handed circular polarized radiation waves and dynamically control the corresponding radiation angles by adjusting the ON/OFF states of two positive-intrinsic-negative diodes in each spin-decoupled meta-atom. Numerous simulation and experimental results of the proof-of-concept prototype are in good agreement with the theoretical predictions, which verify the feasibility of our proposed methodology. The innovative design of four-channel SWs radiation metadevice with high radiation efficiency and broad radiation bandwidth offers an excellent platform for flexibly manipulating SWs radiation, and possesses tremendous potential in engineering application.

A new braiding index to assess river regulation effects in multi‐thread channels: Insights from a highly regulated Himalayan river

AbstractRiver regulation by dams and embankments drastically reduce/alter flow, which affects the natural channel pattern. Existing braiding indices have seldom incorporated the effects of diurnal flow variations caused by hydropeaking, leading to over/underestimation of the braiding intensity. These indices consider only the visible wet channels, ignoring the existence of dry channels that are activated only episodically during phases of water release from hydropower dams. We have extracted the dry channels (those that are periodically wet) coursing across the channel belt of the highly regulated River Tista from Landsat images between 1977 and 2014, using Normalized Difference Wetness Index values. These were combined with existing wet channel widths and numbers to formulate the Regulated Braiding Index (RBi) for characterizing channel braiding in the Tista's course over the Himalayan foothill plains. Overall, the widths and numbers of wet channels decreased by 63% and 25%, respectively, during the regulated years (2003 and 2014) as compared to pre‐dam years (1977 and 1995) due to the collective operation of 14 upstream dams/barrages (having cumulative ~89 million m3 reservoir capacity), whose operations reduced the braiding intensity (eliciting lower RBi values). Further, the number of high braiding reaches decreased by half while low braiding stretches rose by 10% in comparison to the pre‐dam period due to reduced/regulated flow. Comparative analysis of derived RBi values with three existing braiding indices revealed that RBi values consistently decreased near barrages, bridges, and within embankment‐confined reaches, unlike the other indices, thus providing a better framework for assessing expected river regulation effects.

Manajemen Rantai Pasok Produk Beras di Penggilingan Padi Sumber Baru Kecamatan Sidoarjo, Kabupaten Sidoarjo

Research Objectives 1) To analyze the institutions and supply chain members of the rice commodity in the New Sumber Padi Mill; 2) Analyze the supply chain management of rice commodities at the New Sumber Padi Mill; 3) Analyze supply chain trading margins and value chain analysis at the New Source Rice Mill. The analytical method used is descriptive qualitative analysis, quantitative descriptive analysis, and qualitative design. The institutions and supply chain members involved in the rice supply chain at the Sumber Baru Rice Mill are farmers, middlemen, rice millers, retailers, and consumers. The supply chain channel pattern has three supply chain channel patterns. The product flow occurs from farmers selling grain to rice in the hands of consumers. The financial flow of the two-channel patterns is equally profitable. Then the information flow occurs because each has a two-way flow of information between institutions and supply chain members. The trading system margin for each trading system channel is different. The highest added value is in the rice mill.

Activity and community structure of nitrifiers and denitrifiers in nitrogen-polluted rivers along a latitudinal gradient

Nitrogen (N) cycling in rivers is particularly active and dynamic due to excess nutrient inputs worldwide. However, the multidimensional spatial patterns of the activity and community structure of N-cycling microorganisms in rivers remain unclear, limiting our understanding of river ecological functions, especially N removal capacity. Here, we measured the nitrification and denitrification rates and identified nitrifying and denitrifying microorganisms using high-throughput sequencing of archaeal amoA, bacterial amoA, nirK, and nirS genes in channel sediments, riparian rhizosphere soils, and riparian bulk soils of 30 N-polluted rivers across China. Results showed that in the lateral dimension, nitrification rates in sediments did not differ significantly from those in rhizosphere and bulk soils, but denitrification rates were higher in sediments than in bulk soils. However, the archaeal amoA gene abundance in sediments was considerably lower than that in rhizosphere and bulk soils, and bacterial amoA gene abundance in sediments was greater than that in rhizosphere soils. In the vertical dimension, both nitrification and denitrification rates in riparian bulk soils decreased with soil depth, and topsoils harbored more nitrifying and denitrifying microbes than subsoils. Denitrification but not nitrification rates increased with latitude and altitude but decreased with increasing mean annual temperature and precipitation. Overall, these results provide new insights into the multidimensional spatial patterns of river N cycling at a large scale, which is crucial to evaluating the N removal function of global rivers.

Marketing Channel Patterns And Marketing Costs Of Imported Buffalo Meat By Badan Urusan Logistik (Bulog) In Bandung City

This research was held at Badan Urusan Logistik (Bulog), PT. Yoga Mandiri Utama, retailers in the (Market) Ciroyom, Caringin, and Astana Anyar in January 2017 to February 2017. The aim of this research is to determine the pattern of the distribution channel and marketing costs of imported buffalo meat of Badan Urusan Logistik (Bulog) in Bandung City. The method of this research is case study. Analysis of data using analysis costs, margins, and profits. Based on the research, it is known that some distribution channel patterns are formed, channel one: Producer - Bulog - Consumers, channels two: Producer - Bulog - PT. Yoga Utama Mandiri - Consumer, channels three: Producer - Bulog - PT.Yoga Mandiri Utama - Wulandari's catering, channels four: Producer - Bulog - PT. Yoga Utama Mandiri - Supplier - Retailers - Consumer. Total costs incurred by each marketing channel patterns is channel one Rp10.670,00 per kilogram, channel two Rp2.840,00 per kilogram, channel three Rp3.740,00 per kilogram, and channel four Rp4.640,00 Rp per kilogram. The amount of profit earned by each of marketing pattern is channels one Rp330,00 per kilogram, channel two Rp Rp2.160,00 per kilogram, channel three Rp4.260,00 per kilogram, and channel four Rp6.360,00 per kilogram

Submarine‐channel meandering reset by landslide filling, Taranaki Basin, New Zealand

AbstractLandslides are among the largest mass movements on Earth. As such, the deposits of landslides, also known as mass‐transport deposits, are significant architectural elements of continental margins, especially those receiving sediment from large deltas. Landslide dams have been shown to alter the courses of rivers and submarine channels. However, there are fewer examples of landslides completely filling submarine channels and examples of the subsequent stratigraphic evolution. A three‐dimensional seismic‐reflection dataset (<90 Hz) from the deep‐water (>1500 m) Taranaki Basin, offshore the North Island of New Zealand, was used to explore the response of a sequence of channel deposits to landslide filling. The basal channel system initially meandered like a river, with successive channel positions in close proximity, as it aggraded >250 ms two‐way travel time. This systematic, organised evolution is governed by the memory of early channel evolution, which sets the sea floor geomorphology that guides channel‐forming turbidity currents. Later, a channel approximately twice as wide as underlying channels cut off a number of channel bends, probably as a result of an increase in the discharge of channel‐forming turbidity currents. This last channel was filled with submarine landslides, which transported and deposited sediment as debris flows based on the presence of blocks within a matrix comprising chaotic, lower amplitude seismic facies. These debris‐flow deposits smoothed over the sea floor, effectively wiping the memory of channel evolution. As a result, the subsequent channel pattern bears no resemblance to the basal system. Submarine‐channel resetting by landslide filling is common in settings with frequent catastrophic basin‐margin collapses, like offshore New Zealand.

River pattern influences the composition of small indigenous species (SIS) of fish in deltaic Rajbari district, Bangladesh

Bangladesh is endowed with diverse rivers providing huge ecosystem services, but the diversity status and the abundance of the small indigenous species (SIS) are not identical in all rivers due to the natural water flow regime and anthropogenic challenges. Therefore, the present study endeavors to elucidate the composition and conservation status of SIS fish from four rivers namely, the Padma, the Gorai, the Chandana and the Horai rivers of Rajbari District, Bangladesh. Data were meticulously collected through fish sampling in each season, field observations, focus group discussions, and individual interviews by using a semi-structured questionnaire spanning from May 2021 and April 2022. The number of SIS in the Padma, the Gorai, the Chandana and the Horai rivers of Rajbari were 60, 36, 33 and 26, respectively, whereas a predominant concentration of fishes was notably observed in the benthopelagic zone of these rivers. Among the 60 riverine SIS, 23 fish were common in the four rivers. Additionally, Cyprinidae (>30%) was observed to be the most abundant SIS in the studied rivers. The fishermen in the research area used seven major fishing equipment of which cast nets are the most common for catching fish species. The abundance of SIS during the rainy season was the highest for all the studied rivers than the other seasons and 12 SIS were available throughout the year. Notably, the least concerned SIS outnumbered the other categories whereas, more than 10% was under the vulnerable category in the four rivers. The leading threats to the fish diversity were pollution followed by illegal and overfishing, siltation, reduced depth, degeneration of rivers and others. Consequently, to safeguard the existing SIS, reducing human pressure, implementing fishing regulations strictly, establishing and administering fish sanctuaries, and raising public awareness can be helpful for the sustainability of aquatic resources in deltaic areas.

Effect of Silicon Carbide Fiber Length on the Flexural Strength and Flexural Modulus of Short Silicon Carbide Fiber-Reinforced Resin.

Silicon carbide fibers have superior flexural properties and chemical stability compared to glass fibers. We investigated the flexural strength and modulus of an experimental, short silicon carbide fiber-reinforced resin. Short silicon carbide fibers with lengths of ~0.5, 1, 2, and 3 mm were prepared and silanized. Urethane dimethacrylate and triethylene glycol dimethacrylate were mixed at a 70:30 wt% ratio and used as the matrix resins. Each length of short silicon carbide fibers and the matrix resin were combined using a mixing machine and then used for specimen preparation. The three-point bending test conditions were in accordance with ISO 4049:2009. The fracture surfaces of the specimens after the three-point bending test were observed using secondary electron images. The data were statistically analyzed with a one-way analysis of variance and Tukey's HSD test (α = 0.05). The flexural strength and modulus of the specimens containing 2 mm or 3 mm silicon carbide fibers were significantly higher than the other specimens. The river pattern was observed more clearly in specimens containing shorter silicon carbide fibers, although this pattern was observed in all specimens.

Micropillar‐based channel patterning in high‐loading graphite anodes for superior Li‐ion batteries

AbstractThis study presents a low‐cost, one‐step electrode patterning method that uses a template with micropillars to indent a hexagonal array of channels in high‐loading graphite anodes for faster electrolyte infiltration and Li‐ion transport. In contrast to prior studies on using laser micro‐machining, active material losses could be completely avoided by the proposed methodology. The process can also be made roll‐to‐roll and continuous. Furthermore, the very small volume fraction of the introduced channels (<1 wt.%) has little impact on practically attainable energy density or specific energy. Yet, thus introducing pore channels significantly reduces electrolyte infiltration time and improves rate performance.