scholarly journals Nano-Fibrous Networks from Co-Assembly of Amphiphilic Peptide and Polyelectrolyte

Polymers ◽  
2021 ◽  
Vol 13 (22) ◽  
pp. 3983
Author(s):  
Thomas Babut ◽  
Mona Semsarilar ◽  
Marc Rolland ◽  
Damien Quemener
Keyword(s):  
Electrostatic Interactions ◽  
Water Pressure ◽  
Tape Casting ◽  
Spray Coating ◽  
Small Scale ◽  
Material Structure ◽  
Supported Membranes ◽  
Production Methods ◽  
Filtration Membranes ◽  
Fibrous Network

Organize the matter on an increasingly small scale is sought in order to increase the performance of materials. In the case of porous materials, such as filtration membranes, a compromise must be found between the selectivity provided by this nanostructuring and a permeability in particular linked to the existing pore volume. In this work, we propose an innovative waterborne approach consisting in co-assembling peptide amphiphiles (PA) which will provide nanostructuring and polyelectrolytes which will provide them with sufficient mechanical properties to sustain water pressure. C16-V3A3K3G-NH2 PA nanocylinders were synthesized and co-assembled with poly(sodium 4-styrenesulfonate) (PSSNa) into porous nano-fibrous network via electrostatic interactions. The ratio between C16-V3A3K3G-NH2 and PSSNa was studied to optimize the material structure. Since spontaneous gelation between the two precursors does not allow the material to be shaped, various production methods have been studied, in particular via tape casting and spray-coating. Whereas self-supported membranes were mechanically weak, co-assemblies supported onto commercial ultrafiltration membranes could sustain water pressure up to 3 bars while a moderate permeability was measured confirming the existence of a percolated network. The produced membrane material falls into the ultrafiltration range with a pore radius of about 7.6 nm.

Type of Slope Failure Identified from Pore Water Pressure and Moisture Content Measurements

2015 ◽  
Vol 744-746 ◽  
pp. 690-694
Author(s):  
Muhammad Rehan Hakro ◽  
Indra Sati Hamonangan Harahap
Keyword(s):  
Moisture Content ◽  
Pore Pressure ◽  
Slope Failure ◽  
Pore Water Pressure ◽  
Water Pressure ◽  
Failure Process ◽  
Small Scale ◽  
Content Increase ◽  
Sudden Increase ◽  
Model Slope

Rainfall-induced landslides occur in many parts of the world and causing a lot of the damages. For effective prediction of rainfall-induced landslides the comprehensive understanding of the failure process is necessary. Under different soil and hydrological conditions experiments were conducted to investigate and clarify the mechanism of slope failure. The failure in model slope was induced by sprinkling the rainfall on slope composed of sandy soil in small flume. Series of tests were conducted in small scale flume to better understand the failure process in sandy slopes. The moisture content was measured with advanced Imko TDR (Time Domain Reflectrometry) moisture sensors in addition to measurements of pore pressure with piezometers. The moisture content increase rapidly to reach the maximum possible water content in case of higher intensity of rainfall, and higher intensity of the rainfall causes higher erosion as compared to smaller intensity of the rainfall. The controlling factor for rainfall-induced flowslides was density of the slope, rather than intensity of the rainfall and during the flowslide the sudden increase in pore pressure was observed. Higher pore pressure was observed at the toe of the slope as compared to upper part of the slope.

scholarly journals Fabrication Techniques for Graphene Oxide-Based Molecular Separation Membranes: Towards Industrial Application

Nanomaterials ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 757
Author(s):  
Ohchan Kwon ◽  
Yunkyu Choi ◽  
Eunji Choi ◽  
Minsu Kim ◽  
Yun Chul Woo ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Large Scale ◽  
Spray Coating ◽  
Dip Coating ◽  
Small Scale ◽  
Scale Production ◽  
Separation Membranes ◽  
Current Review ◽  
Slot Die ◽  
Continuous Fabrication

Graphene oxide (GO) has been a prized material for fabricating separation membranes due to its immense potential and unique chemistry. Despite the academic focus on GO, the adoption of GO membranes in industry remains elusive. One of the challenges at hand for commercializing GO membranes lies with large-scale production techniques. Fortunately, emerging studies have acknowledged this issue, where many have aimed to deliver insights into scalable approaches showing potential to be employed in the commercial domain. The current review highlights eight physical methods for GO membrane fabrication. Based on batch-unit or continuous fabrication, we have further classified the techniques into five small-scale (vacuum filtration, pressure-assisted filtration, spin coating, dip coating, drop-casting) and three large-scale (spray coating, bar/doctor blade coating, slot die coating) approaches. The continuous nature of the large-scale approach implies that the GO membranes prepared by this method are less restricted by the equipment’s dimensions but rather the availability of the material, whereas membranes yielded by small-scale methods are predominately limited by the size of the fabrication device. The current review aims to serve as an initial reference to provide a technical overview of preparing GO membranes. We further aim to shift the focus of the audience towards scalable processes and their prospect, which will facilitate the commercialization of GO membranes.

scholarly journals The Triumph of Large-Scale Agriculture and Its Socioeconomic Impact

2018 ◽  
Vol 43 (2) ◽  
pp. 95-106
Author(s):  
András Schlett ◽  
Judit Beke
Keyword(s):  
Rural Areas ◽  
Large Scale ◽  
Socioeconomic Impact ◽  
Small Scale ◽  
Production Methods ◽  
Advantages And Disadvantages ◽  
Key Drivers

Large-scale farming that utilizes industrial methods to intensify production is becoming more significant worldwide. This study explores this phenomenon and sheds light on its consequences. Contingency factors serve as key drivers when determining the advantages and disadvantages of both large-scale and small-scale farming. Significant shifts in agro-production methods have fundamentally altered ownership and production structures in agriculture and had a disastrous impact on the livelihoods of people living in rural areas.

scholarly journals Durability of Road and Bridge Concrete and Spray-Coating Waterproof Material

2021 ◽  
Vol 31 (4) ◽  
pp. 227-235
Author(s):  
Liang Wei
Keyword(s):  
Bridge Deck ◽  
Water Pressure ◽  
Spray Coating ◽  
Internal Force ◽  
Drain Pipe ◽  
The Road ◽  
Before And After ◽  
High Elongation ◽  
Research Gap ◽  
The Impact

Different from traditional waterproof methods for road and bridge concrete, the spray-coating waterproof material can effectively prevent rainwater and other corrosive liquids from entering the concrete structure, and it has a few functional advantages such as anti-carbonization, resistance to sulfate attack, and high elongation. Existing studies have discussed the impact of the microstructure of waterproof material on the structure of waterproof coating, the optimization of the mix ratios of waterproof material, and the influencing factors of the waterproof performance of waterproof material, etc., however, few researches have concerned about the mechanical properties of concrete after coated with the spray-coating waterproof material. Therefore, to fill in this research gap, this paper researched the durability of road and bridge concrete and the spray-coating waterproof material. At first, it analyzed the bridge deck water pressure and the internal force of the drain pipe structure under multiple drainage methods, and calculated the water pressure at the gutter inlet, the stress, and the permeability coefficient of the waterproof coating. Then, this paper elaborated on the experimental methods for measuring the durability of the road and bridge before and after coated with the spray-coating waterproof material, and introduced the methods for testing the waterproof material and the concrete. At last, this paper gave the corresponding experimental results, the analysis, and the conclusion.

scholarly journals General Theory of Subglacial Cavitation and Sliding of Temperate Glaciers

1968 ◽  
Vol 7 (49) ◽  
pp. 21-58 ◽  
Author(s):  
L. Lliboutry
Keyword(s):  
Frictional Force ◽  
Atmospheric Pressure ◽  
Hydraulic System ◽  
Water Pressure ◽  
Realistic Model ◽  
Point Of View ◽  
Small Scale ◽  
Sliding Velocity ◽  
Surface Slope ◽  
Geometrical Progression

AbstractEarlier theories of Weertman and the present author are reviewed and compared; both are insufficient to account for the facts observed at the tongue of the Allalingletscher.A calculation of the stresses and heat flow at the bed of a glacier with a sinusoidal profile is given which takes account of any degree of subglacial cavitation. The sliding due to plasticity and that due to pressure melting are related to this degree of cavitation and it is shown that these two terms are additive. There results an expression for the frictionfωin terms of the total sliding velocityuand the height of the bumpsa. For a given and large enough value ofu,fω(a) exhibits two maxima which are equal and independent ofu.The paper then considers a more realistic model of the bed consisting of a superposition of sine waves all having the same roughnessr, andadecreasing in a geometrical progression. The biggestamay be inferred from the overall profile of the bedrock; the resulting frictional force can be regarded either as part of the total frictional forcefin an overall view for whichf=ρghsinαholds, or else as a correction to such a value on the small scale (the best point of view for crevasse studies). To a first approximation Coulomb’s law of friction holds provided one takes account of the interstitial water pressure at the ice-rock interface.This interstitial pressurepis next related to the thickness of the glacierh. If the subglacial hydraulic system is at atmospheric pressure,pis proportional toh. Next, if the sliding velocity is not too large, the surface slope approaches 1.6r≈ 0.12 and kinematic waves (which move four times as fast as the ice) disappear rapidly. If the hydraulic system is not at atmospheric pressure the surface slope is smaller and flow instabilities can occur.

scholarly journals PROTOTYPE DESIGN OF MICRO HYDRO USING TURBINE ARCHIMEDES SCREW FOR SIMULATION OF HIDROPOWER PRACTICAL OF ELECTRO ENGINEERING STUDENTS

2019 ◽  
Vol 3 (1) ◽  
pp. 6
Author(s):  
Antonius Ibi Weking ◽  
Yanu Prapto Sudarmojo
Keyword(s):  
Energy Source ◽  
Power Plants ◽  
Engineering Students ◽  
Low Cost ◽  
Water Pressure ◽  
Water Discharge ◽  
Small Scale ◽  
Engineering Department ◽  
Influence Of Water ◽  
Turbine Speed

Development of new and renewable energy source always developed by world researchers which one of those is energy source from water, because it’s friendly for environment and low cost. Water is one of energy source which it’s have big potential in all Indonesian territory. The main problem from microhydropower plants is a water discharge which it’s flow is not continued every year because influenced by weather season. Micro Hydro is a microhydro power plants (MHP)in a small scale. A micro hydro can be operated in a certain of time if it has a enough water supply. To knowing a right of micro hydro’s  characteristic is not easy thing to learn it. It is because a characteristic each of micro hydro’s installation location is considered specific location.               One type of micro hydro is using Archimedes Screw Turbine. Udayana University of Electrical Engineering Department in this time not have a facility for hydropower field to use this model, so a college student not yet to receive a knowledge of this. Through this research, a writer want to expand a college student’s knowledge in hydropower field with create a prototype of micro hydro with Archimedes Screw Turbine to hydropower practical in laboratory. In this research the effect of screw’s height angle conversion and effect of water pressure conversion has to be researched. In this study will discuss the influence of water pressure and slope of the altitude angle on the rotation produced by the Archimedes screw turbine so that it can be seen the voltage, current, power generated by the generator, torque and efficiency . The result of from handmade equipment for this research in angle 40­0 with biggest generator round (rpm) is 3768 (rpm) and highest power is 10.92057 watt, torque adalah 0.60 Nm dan efisiensi sebesar 14 %. The torque which resulted from water pressure 24 psi is 0,73 Nm and efficience 18,01 %. The voltage, current, and output power which resulted in generator is 85,8 Volt, 0,1963 Ampere and 16,85 Watt. For generator speed round in the pressure 24 Psi is 4582 rpm, while turbine speed round which resulted from the pressure 24 Psi is 383 rpm before coupled with generator and 222 rpm after coupled with generator.

scholarly journals Experimental insights into consolidation rates during one-dimensional loading with special reference to excess pore water pressure

2020 ◽  
Vol 15 (12) ◽  
pp. 3571-3591
Author(s):  
Bartłomiej Szczepan Olek
Keyword(s):  
Pore Water ◽  
Large Scale ◽  
Pore Water Pressure ◽  
Water Pressure ◽  
Small Scale ◽  
Coefficient Of Consolidation ◽  
Consolidation Process ◽  
Factors Affecting ◽  
Fine Grained ◽  
Fine Grained Soil

AbstractConsolidation rate has significant influence on the settlement of structures founded on soft fine-grained soil. This paper presents the results of a series of small-scale and large-scale Rowe cell consolidation tests with pore water pressure measurements to investigate the factors affecting the consolidation process. Permeability and creep/resistance structure factors were considered as the governing factors. Intact and reconstituted marine clay from the Polish Carpathian Foredeep basin as well as clay–sand mixtures was examined in the present study. The fundamental relationship correlating consolidation degrees based on compression and pore water pressure was assessed to indicate the nonlinear soil behaviour. It was observed that the instantaneous consolidation parameters vary as the process progresses. The instantaneous coefficient of consolidation first drastically increases or decreases with increase in the degree of consolidation and stabilises in the middle stage of the consolidation; it then decreases significantly due to viscoplastic effects occurring in the soil structure. Based on the characteristics of the relationship between coefficient of consolidation and degree of dissipation at the base, the consolidation range that complies with theoretical assumptions was established. Furthermore, the influence of coarser fraction in clay–sand mixtures in controlling the consolidation rates is discussed.

scholarly journals Modeling of Some Operating Parameters Required for the Development of Fixed Bed Small Scale Pyrolysis Plant

Resources ◽  
2019 ◽  
Vol 8 (2) ◽  
pp. 79 ◽  
Author(s):  
Bacskai ◽  
Madar ◽  
Fogarassy ◽  
Toth
Keyword(s):  
Fixed Bed ◽  
Gas Production ◽  
Design Stage ◽  
Small Scale ◽  
Material Structure ◽  
Mathematical Function ◽  
Operating Characteristics ◽  
Biomass Waste ◽  
Experimental Apparatus ◽  
Pyrolysis Unit

In recent years, we have read a lot of research aimed at creating a small, easy-to-mobilize pyrolysis unit. But these devices were not efficiently designed. According to literature data, small equipment (5.0–50 kW) has to be considered differently on the combustion aspects, compared to a larger pyrolysis unit. The main purpose of our research is to determine the operating characteristics of a small fixed bedding CHP (combined heat and power) pyrolysis power plant. At the design stage, it is also critical to know the properties of the biomass (usually different biological wastes) used on the input side. The use of a wide diversity of biomass waste may result in the volume of material remains and the energy produced is not usable in the right form. To obtain a clear picture of the combustion conditions, a fixed bedding pilot pyrolysis device was made. With the measurements in the experimental apparatus, we have a clearer picture of the changes in some of combustion parameters. We have examined exactly how the size and hardness of biomass materials affect the efficiency of pyrolysis. By modelling the “mass change”—with the knowledge of the material content, physical characteristics, and the parameters of the pyrolysis equipment—the amount of the expected material remains, and combustion conditions can be predicted with a mathematical function. We have found an appropriate mathematical model (R2 = 0.8758) to describe the relationship between gas production and material structure for a given period.

Structure Data from Light Scattering Studies of Aerogel

1984 ◽  
Vol 32 ◽  
Author(s):  
Arlon J. Hunt ◽  
Paul Berdahl
Keyword(s):  
Light Scattering ◽  
Optical Materials ◽  
Scattered Light ◽  
Average Density ◽  
Scattering Data ◽  
Small Scale ◽  
Material Structure ◽  
Structure Parameters ◽  
Microporous Structure ◽  
The Fourier Transform

ABSTRACTThis paper reports a recent advance in the understanding of the structure of microporous optical materials such as aerogel through the interpretation of light scattering data. The Fourier transform of the densitydensity correlation function is used to relate measurements of the angular dependence of scattered light to material structure parameters. The results of the approach fit the unusual dependence of the intensity of scattered light as a function of angle for two polarizations. The fit shows that light scattering from aerogels may be interpreted as having two origins; one from the small scale structure of linked particles that comprise the material, and the second due to weak fluctuations in the average density of the microporous structure over distances significantly larger than the pore size.

The Commercialisation of British Turkey Production

Rural History ◽  
2009 ◽  
Vol 20 (2) ◽  
pp. 209-228 ◽  
Author(s):  
JOHN MARTIN
Keyword(s):  
United Kingdom ◽  
Disease Control ◽  
Mass Production ◽  
Small Scale ◽  
Supply Side ◽  
Seasonal Activity ◽  
Production Sector ◽  
Production Methods ◽  
The United Kingdom ◽  
Improved Methods

AbstractSince the 1930s turkey production in the United Kingdom has been transformed from a small scale, seasonal activity catering exclusively for the Christmas market, to an intensive mass production sector dominated by all year round producers, of which Bernard Matthews is the best known. This revolution in production methods reflects improved methods of disease control, enhanced nutritional understanding, and the development of more productive strains of turkeys with better conformation. These supply side changes have been accompanied by a succession of very successful marketing campaigns to persuade consumers of the merits of eating turkey throughout the year. This article investigates the reasons for the commercialisation of the turkey industry since the 1930s.

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