The rebirth and eco-friendly energy production of an artificial lake: A case study on the tidal power in South Korea

Overtopping-type wave power conversion devices represent one of the most promising technology to combine reliability and competitively priced electricity supplies from waves. While satisfactory hydraulic and structural performance have been achieved, the selection of the hydraulic turbines and their regulation is a complex process due to the very low head and a variable flow rate in the overtopping breakwater set-ups. Based on the experience acquired on the first Overtopping BReakwater for Energy Conversion (OBREC) prototype, operating since 2016, an activity has been carried out to select the most appropriate turbine dimension and control strategy for such applications. An example of this multivariable approach is provided and illustrated through a case study in the San Antonio Port, along the central coast of Chile. In this site the deployment of a breakwater equipped with OBREC modules is specifically investigated. Axial-flow turbines of different runner diameter are compared, proposing the optimal ramp height and turbine control strategy for maximizing system energy production. The energy production ranges from 20.5 MWh/y for the smallest runner diameter to a maximum of 34.8 MWh/y for the largest runner diameter.

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Large weir construction causes the loss of seasonal habitat in riverine wetlands: a case study of the Four Large River Projects in South Korea

Ecological Engineering ◽

10.1016/j.ecoleng.2020.105839 ◽

2020 ◽

Vol 152 ◽

pp. 105839

Author(s):

Ran-Young Im ◽

Ji Yoon Kim ◽

Jun Nishihiro ◽

Gea-Jae Joo

Keyword(s):

South Korea ◽

Large River ◽

Riverine Wetlands

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A Qualitative Case Study on Influencing Factors of Parents’ Child Abuse of North Korean Refugees in South Korea

Healthcare ◽

10.3390/healthcare9010049 ◽

2021 ◽

Vol 9 (1) ◽

pp. 49

Author(s):

Wonjung Ryu ◽

Hyerin Yang

Keyword(s):

Child Abuse ◽

South Korea ◽

Influencing Factors ◽

Acculturative Stress ◽

North Korean Refugees ◽

Korean Parents ◽

Before And After ◽

Maternal Parenting Stress ◽

Past Experiences

The purpose of this study is to investigate the influencing factors of parental child abuse by North Korean refugees who are living in South Korea. In-depth interviews were conducted with five parents who escaped from North Korea. The study identified three categories of factors impacting child abuse: the weakening of family functions from past experiences before and after defection, the stress of adapting to the culture of an unfamiliar society, and low parenting self-efficacy. North Korean parents suffered from emotional and functional crises from past traumatic events and, at the same time, experienced additional acculturative stress as a “minority” after entering South Korea, even as they continued to deal with Maternal Parenting Stress. These complex factors have been shown to lead to child abuse in migrant societies. This study contemplated the context of child abuse through specific examples. The results could provide thoughtful insights into child abuse among migrants and refugee parents, and provide evidence-based intervention plans for its prevention.

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Photovoltaic Cleaning Optimization: A Simplified Theoretical Approach for Air to Water Generator (AWG) System Employment

Energies ◽

10.3390/en14144271 ◽

2021 ◽

Vol 14 (14) ◽

pp. 4271

Author(s):

Lucia Cattani ◽

Paolo Cattani ◽

Anna Magrini

Keyword(s):

Energy Loss ◽

Energy Production ◽

New Technologies ◽

Optimization Procedure ◽

System Size ◽

Design Tool ◽

Semiempirical Model ◽

Photovoltaic Panel ◽

Water Amount

Photovoltaic panel efficiency can be heavily affected by soiling, due to dust and other airborne particles, which can determine up to 50% of energy production loss. Generally, it is possible to reduce that impact by means of periodic cleaning, and one of the most efficient cleaning solutions is the use of demineralized water. As pauperization of traditional water sources is increasing, new technologies have been developed to obtain the needed water amount. Water extracted from the air using air to water generator (AWG) technology appears to be particularly suitable for panel cleaning, but its effective employment presents issues related to model selection, determining system size, and energy efficiency. To overcome such issues, the authors proposed a method to choose an AWG system for panel cleaning and to determine its size accordingly, based on a cleaning time optimization procedure and tailored to AWG peculiarities, with an aim to maximize energy production. In order to determine the energy loss due to soiling, a simplified semiempirical model (i.e., the DIrt method) was developed as well. The methodology, which also allows for energy saving due to an optimal cleaning frequency, was applied to a case study. The results show that the choice of the most suitable AWG model could prevent 83% of energy loss related to soling. These methods are the first example of a design tool for panel cleaning planning involving AWG technology.

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