A Novel Design of Hybrid Hydrophilic-Superhydrophobic Surfaces for Fog Harvesting

The continuous growth in the human population and climate change exacerbates the problems related to water scarcity. Harvesting the atmospheric water can mitigate the water scarcity in many regions around the globe. Fog collection using hybrid hydrophilic-superhydrophobic surfaces has the capacity to achieve a higher water collection rate. In this paper, a new method and materials are introduced to create the hybrid surfaces. The method includes additive manufacturing- to make sheets with holes-, mixing and casting polymeric matrix composite, and a controlled spray coating mechanism. The materials comprised of hydrophobic coating on top of the acrylic printed sheet and hydrophilic composite. The ratios of the pitches to diameters of the hydrophilic regions varied during the experiments to obtain the best water generation. The water collection rate for the sample with diameters of 583 um and a pitch of 1600 um has achieved 57% more than the untreated hydrophilic sample. The contrast in wettability accomplished by this novel method has the potential to be implemented on a large scale for atmospheric water harvesting.

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Research on the Marketing Strategy of Online Education -- Taking New Oriental as an Example

Journal of Management Science & Engineering research ◽

10.30564/jmser.v2i2.1922 ◽

2020 ◽

Vol 2 (2) ◽

Author(s):

Jialu Chen ◽

Yingxiao Han ◽

An Li

Keyword(s):

Online Learning ◽

Online Education ◽

Online Teaching ◽

Large Scale ◽

Target Market ◽

Growth Trend ◽

Continuous Growth ◽

Financial Investment ◽

Marketing Mode ◽

Marketing Costs

In recent years, with the development of society and the progress of science and technology, online learning has penetrated into people's daily life, and people's demand for high-quality curriculum products is more and more strong. From a macro perspective, the continuous growth of national financial investment in education, the continuous upgrading of China's consumption structure, the development of 5G technology and the popularization of AI intelligence make online teaching less limited. The online education industry is showing an explosive growth trend. More and more online education institutions are listed for financing, and the market value is soaring. However, in 2019, except for GSX, the latest online learning platforms such as New Oriental, Speak English Fluently and Sunlands, have been in a state of loss. Most of these agencies seize the market by increasing advertising investment, but at the same time, they also bring huge marketing costs, which affect the financial performance of the company. With the enhancement of Matthew effect, large-scale educational institutions occupy a large market through free classes and low-price classes, while small and medium-sized institutions with weak capital strength are often unable to afford high sales costs, facing the risk of capital chain rupture. Taking new Oriental online as an example, this paper analyzes the problems existing in the marketing strategies of online education institutions. It also puts forward suggestions on four aspects, which are target market, differentiated value, marketing mix and marketing mode, so as to make sure that online education institutions can control marketing expenses and achieve profits by improving course quality, expanding marketing channels and implementing precise positioning.

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Dryland Degradation and Expansion: Implications for Mexican Policies from the Earth System Perspective

Environmental Policy and Law ◽

10.3233/epl-201024 ◽

2020 ◽

pp. 1-4

Author(s):

Gabriel Lopez Porras

Keyword(s):

Climate Change ◽

Ecosystem Services ◽

Science Policy ◽

Land Degradation ◽

Water Scarcity ◽

Large Scale ◽

Earth System ◽

Sustainable Land Management ◽

System Perspective ◽

The Earth

Despite international efforts to stop dryland degradation and expansion, current dryland pathways are predicted to result in large-scale migration, growing poverty and famine, and increasing climate change, land degradation, conflicts and water scarcity. Earth system science has played a key role in analysing dryland problems, and has been even incorporated in global assessments such as the ones made by the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services. However, policies addressing dryland degradation, like the ‘Mexican programme for the promotion of sustainable land management’, do not embrace an Earth system perspective, so they do not consider the complexity and non-linearity that underlie dryland problems. By exploring how this Mexican programme could integrate the Earth system perspective, this paper discusses how ’Earth system’ policies could better address dryland degradation and expansion in the Anthropocene.

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Janus Membrane with Novel Directional Water Transport Capacity for Efficient Atmospheric Water Capture

Nanoscale ◽

10.1039/d1nr01120k ◽

2021 ◽

Author(s):

Jing Wu ◽

Baona Ren ◽

Haohong Pi ◽

Xin Zhao ◽

Miaomiao Hu ◽

...

Keyword(s):

Fresh Water ◽

Water Transport ◽

Water Scarcity ◽

Low Cost ◽

Transport Capacity ◽

Atmospheric Water ◽

Human Survival ◽

Survival And Development ◽

Energy Independence

Fresh water scarcity becomes a crisis to human survival and development. Atmospheric water capture with remarkable advantages such as energy-independence, low-cost, etc., has been supposed as a promising way to...

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

Nanomaterials ◽

10.3390/nano11030757 ◽

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.

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Applying Biomimetic Principles to Thermoelectric Cooling Devices for Water Collection

Environment and Natural Resources Research ◽

10.5539/enrr.v7n3p27 ◽

2017 ◽

Vol 7 (3) ◽

pp. 27

Author(s):

Kyle B Davidson ◽

Bahram Asiabanpour ◽

Zaid Almusaied

Keyword(s):

Large Scale ◽

Cost Effective ◽

Thermoelectric Cooling ◽

Device Structure ◽

Cooling Systems ◽

Cooling Devices ◽

Water Collection ◽

Maximum Water ◽

The Ideal

The shortage of freshwater resources in the world has developed the need for sustainable, cost-effective technologies that can produce freshwater on a large scale. Current solutions often have extensive manufacturing requirements, or involve the use of large quantities of energy or toxic chemicals. Atmospheric water generating solutions that minimize the depletion of natural resources can be achieved by incorporating biomimetics, a classification of design inspired by nature. This research seeks to optimize thermoelectric cooling systems for use in water harvesting applications by analyzing the different factors that affect surface temperature and water condensation in TEC devices. Further experiments will be directed towards developing a robust, repeatable system, as well as an accurate measurement system. Surface modifications, device structure and orientation, and power generation will also be studied to better understand the ideal conditions for maximum water collection in thermoelectric cooling systems.

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Working towards sustainable urban water management: the vulnerability blind spot

Water Science & Technology ◽

10.2166/wst.2011.774 ◽

2011 ◽

Vol 64 (12) ◽

pp. 2362-2369 ◽

Cited By ~ 14

Author(s):

L. Werbeloff ◽

R. Brown

Keyword(s):

Water Management ◽

Water Scarcity ◽

Large Scale ◽

Holistic Approach ◽

Blind Spot ◽

Response Strategy ◽

Urban Water ◽

Urban Water Management ◽

Sustainable Urban Water Management ◽

Diversity Strategy

The unprecedented water scarcity in Australia coincides with the adoption of a new urban water rhetoric. The ‘Security through Diversity’ strategy has been adopted in a number of Australian cities as a new and innovative approach to urban water management. Although this strategy offers a more holistic approach to urban water management, in practice, the Security through Diversity strategy is largely being interpreted and implemented in a way that maintains the historical dependence on large scale, centralised water infrastructure and therefore perpetuates existing urban water vulnerabilities. This research explores the implementation of Security through Diversity as the new water scarcity response strategy in the cities of Perth and Melbourne. Through a qualitative study with over sixty-five urban water practitioners, the results reveal that the practitioners have absorbed the new Security through Diversity language whilst maintaining the existing problem and solution framework for urban water management. This can be explained in terms of an entrenched technological path dependency and cognitive lock-in that is preventing practitioners from more comprehensively engaging with the complexities of the Security through Diversity strategy, which is ultimately perpetuating the existing vulnerability of our cities. This paper suggests that greater engagement with the underlying purpose of the security though diversity strategy is a necessary first step to overcome the constraints of the traditional technological paradigm and more effectively reduce the continued vulnerability of Australian cities.

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A Simple Method to Create Superhydrophobic Aluminium Surfaces

Materials Science Forum ◽

10.4028/www.scientific.net/msf.706-709.2874 ◽

2012 ◽

Vol 706-709 ◽

pp. 2874-2879 ◽

Cited By ~ 10

Author(s):

R. Jafari ◽

Masoud Farzaneh

Keyword(s):

Contact Angle ◽

Stearic Acid ◽

Synergistic Effects ◽

Low Cost ◽

Contact Angle Hysteresis ◽

Spray Coating ◽

Superhydrophobic Surfaces ◽

Water Contact ◽

Simple Method ◽

Static Contact

Superhydrophobic surfaces were prepared using a very simple and low-cost method by spray coating. A high static water contact angle of about 154° was obtained by deposition of stearic acid on an aluminium alloy. However, this coating demonstrated a high contact angle hysteresis (~ 30º). On the other hand, superhydrophobic surfaces with a static contact angle of about 162º and 158º, and a low contact angle hysteresis of about 3º and 5º were respectively obtained by incorporating nanoparticles of SiO2and CaCO3in stearic acid. The excellent resulting hydrophobicity is attributed to the synergistic effects of micro/nanoroughness and low surface energy. A study of the wettability of these surfaces at temperatures ranging from 20 to-10 °C showed that the superhydrophobic surface becomes rather hydrophobic at supercooled temperatures.

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