scholarly journals Recent advances in Photocatalytic Nitrogen Fixation

Author(s):  
A. Saravanan

Nitrogen fixation is a standout amongst the most significant concoction responses in the biological system of our planet. Under the regularly pressure of the petroleum product exhaustion emergency and anthropogenic worldwide environmental change with ceaseless CO2 emanation in the 21st century, examine focusing on the union of NH3 under gentle conditions in an economical and condition agreeable way is lively and flourishing. Thusly, the focal point of this survey is the cutting edge designing of effective photocatalysts for dinitrogen (N2) obsession toward NH3 amalgamation. Creating green and feasible techniques for NH3 combination under surrounding conditions, utilizing sustainable power source, is firmly wanted, by both modern and logical scientists. Photosynthesis for ammonia synthesis, which has as of late pulled in noteworthy consideration, straightforwardly creates NH3 from daylight, and N2 and H2O by means of photocatalysis. Photocatalysts containing copious surface oxygen-opportunities and coordinative unsaturated metal locales have been demonstrated to be equipped for actuating N2 reduction under fitting photoexcitation. A few impetus materials are examined which incorporate metal oxides, metals sulfides, carbon-based impetuses, and metal nitrides which are for the most part right now being sought after for their better use of their synergist property towards nitrogen fixation. This chapter portrays the photocatalytic reduction systems of nitrate towards unwanted items (nitrite, ammonium) and the more alluring item (dinitrogen).

The International Biological Programme served as a focal point for studies on biological nitrogen fixation during the 1960s. The introduction of the acetylene reduction technique for measuring nitrogenase activity in the field led to estimates becoming available of the contribution of lichens, blue-green algae, nodulated non-legumes and bacterial-grass associations, as well as of legumes. Other studies carried out on the physiology and biochemistry of the process led to the eventual purification and characterization of the nitrogenase enzyme. These studies, collectively, provided the springboard for current work, so essential in view of the present energy crisis, on how to increase the use and efficiency of nitrogen-fixing plants, on the metabolic regulation of the nitrogenase enzyme and on the genetics of the nitrogen-fixing process, both in higher plants and in free-living micro-organisms.


2021 ◽  

Archives and the Cultural Heritage The edited volume Archives and the Cultural Heritage focuses on archives as institutions and to their tense relationship with archives as material. These dynamics are discussed in respect of the past, the present, and the future. The focus lies in the mechanisms the Finnish archive institutions have utilised when taking part in forming the cultural heritage and in debating the importance of the private archives in society. Within social sciences and history from the early 1990s onwards, the effects of globalisation have been seen as a new focal point for research. Momentarily, the archives saw the same paradigm shift as the focus of the archival studies proceeded from state to society. This brought forth the notion that the values of society are reflected in the acquisition of archival material. This archival turn draws attention to the archives as entities formed by cultural practices. The volume discusses cultural heritage within Finnish archives with diverse perspectives and from various time periods. The key concepts are cultural heritage and archives – both as institution and as material. Articles review the formation of archival collections spanning from the 19th to the 21st century and highlight that the archives have never been neutral or objective actors; rather, they have always been an active process of remembering and forgetting, a matter of inclusion and exclusion. The focus is on private archives and on the choices that guided the creation of the archives and the cultural perceptions and power structures associated with them. Although private archives have considerable social and research value, and although their material complements the picture of society provided by documentary data produced by public administrations, they have only risen to the theoretical discussions in the 21st century. The authors consider what has happened before the material ends up in the archive, what happens in the archive and what can be deduced from this. It shows how archival solutions manifest themselves, how they have influenced research and how they still affect it. One of the key questions is whose past has been preserved and whose is deemed worthy of preservation. Under what conditions have the permanently preserved documents been selected and how can they be accessed? In addition, the volume pays attention to whose documents have been ignored or forgotten, as well as to the networks and power of the individuals within the archival institution and to the politics of memory. The Archives and the Cultural Heritage is an opening to a discussion on the mechanisms, practices and goals of Finnish archival activities. It challenges archival organisations to reflect on their own operating models and to make visible their own conscious or unconscious choices. It raises awareness of the formation of the Finnish documentary cultural heritage, produces new information about private archives and participates in the scientific debate on the changing significance of archives in society. The volume is related to the Academy of Finland research project “Making and Interpreting National Pasts – Role of Finnish Archives as Networks of Power and Sites of Memory” (no 25257, 2011–2014/2019), University of Turku. Project partners Finnish Literature Society (SKS) and Society of Swedish Literature in Finland (SLS).


2006 ◽  
Vol 16 (45) ◽  
pp. 4407 ◽  
Author(s):  
Huaizhou Zhao ◽  
Ming Lei ◽  
Xiaolong Chen ◽  
Weihua Tang

2008 ◽  
Vol 460 (1-2) ◽  
pp. 130-137 ◽  
Author(s):  
M. Lei ◽  
H.Z. Zhao ◽  
H. Yang ◽  
B. Song ◽  
L.Z. Cao ◽  
...  

2015 ◽  
Vol 44 (4) ◽  
pp. 479-500 ◽  
Author(s):  
Florence Pasche Guignard

By appropriating both medical and communication technologies, the gender-reveal party has recently emerged as a ritual performance centered on a dramatically staged disclosure of the sex of a gestating fetus. The gender-reveal party is an example of the new forms of ritualization that take place during pregnancy in 21st-century North America. Typically, the focal point of the party is when the future parents cut a cake whose inside color (blue or pink) reveals the sex of the fetus. This article examines the ritual dynamics and creativity at work in the preparation, the performance and the mediated dissemination of this festive occasion. Key elements of the ritual will be described, as well as its conditions of emergence in a context where neither medical nor religious institutions offer ritual options deemed appropriate enough for celebrating joyfully and emotionally during pregnancy.


2019 ◽  

This volume addresses the ‘question of power’ in current constructivist securitisation studies. How can power relations that affect security and insecurity be analysed from both a transdisciplinary and historical point of view? The volume brings together contributions from history, art history, political science, sociology, cultural anthropology and law in order to determine the role of conceptions of power in securitisation studies, which has tended to be dealt with implicitly thus far. Using conceptual theoretical essays and historical case studies that cover the period from the 16th to the 21st century, this book portrays the dominant paradigms of critical security studies, which mostly stem from the field of international relations and see the state as a major focal point in securitisation, in a new light.


2021 ◽  
pp. 4299-4308
Author(s):  
Jinsun Lee ◽  
Ashwani Kumar ◽  
Min Gyu Kim ◽  
Taehun Yang ◽  
Xiaodong Shao ◽  
...  

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