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Bismuth vanadate (BiVO4) is a promising photoactive material for the design of photoelectrochemical (PEC) analytical devices for the non-enzymatic detection of glucose.

A proper tailoring of the defect structure and varying composition of Eu3+ and Tb3+ dopant ions generate a wide range of color characteristics such as near white, yellow, orange and red in MgF2.

The present study combines density functional theory (DFT) based calculations and experimental techniques to investigate the formation of equiatomic quaternary “low-activation" high entropy alloys (HEAs) for nuclear fission/fusion applications. DFT based techniques are adopted to screen the formation of possible single-phase ternary and quaternary alloys in chemical space consisting of the low-activation elements (Ti, V, Cr, Mn, Fe, Ta and W). The results indicate that TaTiVW and CrFeMnV can be formed in a single body centred cubic phase (BCC). Based on the DFT based screening, HEAs are fabricated by a vacuum arc melting process. Further characterisation by X-ray diffraction, energy dispersive X-Ray analysis, X-ray fluorescence and scanning electron microscopy confirms the formation of TaTiVW in a BCC single phase. Microstructures of CrTiVW and CrTaVW in as-cast conditions, consist of two BCC phases with very similar lattice parameters. CrTaTiW and CrTaTiV showed evidence of C15 Laves formation comprising of TaCr2 and TiV2, respectively.

This study focused on the feasibility of utilizing waste rubber tyre as coarse aggregate in concrete as a partial replacement of brick aggregate (BA). Within this context, fresh and hardened properties were investigated on concrete made with three different percentage replacements (0, 10 and 20% by volume) of BA by waste rubber tyre aggregate (WRTA). The WRTA was washed with tap water (H2O) and treated with 20% sodium hydroxide (NaOH) for 2 hours. It was found that the workability and dry density of concrete decrease with an increasing percentage of WRTA. In case of mechanical properties, the compressive strength decreases with the increasing content of both treated and untreated WRTA. The maximum decrease was observed for 20% of both treated and untreated WRTA, which was 41-46% for treated and 47-54% for untreated lower than the reference concrete for all curing ages. It was observed that the concrete made with tyre treated with NaOH provides better strength than untreated tyre aggregate. This behavior could be attributed to the better bonding between cement paste and rubber aggregates as a result of the increased surface roughness by NaOH.

Wheat cultivation under a dual-purpose (DP) system holds great potential to provide additional fodder for livestock with marginal grain reduction. This study explores the potential of wheat as a DP...

Our knowledge of biochar as a tool for soil carbon (C) sequestration and soil quality in semi-arid regions remains limited in recent years. Moreover, there is a lack of understanding on the comparison between effects of biochar rates on soil organic C (SOC) and nitrogen (N) mineralization in organic C poor soils. Interactive effects of corncob-biochar (B), prepared at 450 °C pyrolysis temperature, and wheat straw (W) on soil native and fresh organic matter were investigated in sandy loam alkaline calcareous soil. The corncob-biochar was applied alone and in combination with wheat straw (WB) at rates equivalent to 0 t ha-1 (unamended control), 22.5 t ha-1 (B1, W1, W1B1), and 45 t ha-1 (B2, W2, W2B2). After treatment applications, soils were incubated under laboratory conditions for 61 days and periodic CO2 evolution rates were measured to calculate the cumulative CO2 efflux and priming effects. The lowest CO2 efflux was found in B2 treatment, whereas CO2 efflux was lower in W1B1 than in W1 treatment. Biochar alone and with wheat straw significantly reduced net C mineralization (NCM) compared to wheat straw only treatments and the effects became stronger as biochar rate increased. This was reflected in data on the priming effect, which also showed that increased biochar rates induced a stronger negative priming (− 87 to − 67%) on SOC. Biochar with wheat straw at both rates enhanced microbial biomass C (MBC) compared to the control, W1, B1, and B2 treatments. However, the W1B1 and W2B2 treatments decreased water-extractable organic C (WEOC) contents compared to W1 and W2. Microbial metabolic quotient (qCO2) and MBC/TOC ratio increased with biochar rate, suggesting more efficient utilization of labile C by microorganisms at higher biochar rate. Biochar alone and with wheat straw reduced soil mineral nitrogen (N) contents than the control treatment and resulted in net negative N mineralization or net N immobilization. Our findings indicate that biochar can reduce decomposition of soil organic matter to facilitate C and N sequestration in low organic C soils. However, our study also suggests the co-application of biochar and organic amendments/residues as labile C source to induce co-metabolism to improve microbial functions and C utilization efficiency in soils that are deficient in organic C.

Cement industry-derived pollutants appear to play multiple roles in stimulating abiotic stress responses in plants. Cement dust deposition on agriculture fields can affect soils, photosynthesis, transpiration and respiration of plants. Here, we characterised the acute physiological responses of Malus × domestica leaves to different cement dust concentrations. The cement dust was sprinkled over plants daily for 2 months at 10 and 20 g/plant, with 0 g/plant serving as the control. Leaf physiological responses revealed significant increases in oxidative stress and antioxidant enzyme activity levels. Additionally, ascorbic acid, soluble sugar, free amino acid, and pigment levels decreased after exposure to cement dust. Macroscopic morphometric parameters, such as weight, dry matter content, and lengths and widths of leaves and buds, were significantly reduced in the cement-treated groups. A histological analysis of leaves and buds revealed decreased cellular areas, cellular damage, and abridged leaf thickness, while an ion leakage assay confirmed the negative effects on tissue integrity. These results provide evidence that cement dust is a hazardous pollutant that induces abiotic stress responses and has degradative effects on leaf health, pigment and biochemical metabolite levels, and anatomical features. Studies to determine the elemental residues of cement dust present in edible plant parts and the adverse impacts of their consumption on human health are strongly recommended.

This research investigates the flexural and durability performances of reinforced concrete (RC) beams made with induction furnace steel slag aggregate (IFSSA) as a replacement for fired clay brick aggregate (FCBA). To achieve this, 27 RC beams (length: 750 mm, width: 125 mm, height: 200 mm) were made with FCBA replaced by IFSSA at nine replacement levels of 0%, 10%, 20%, 30%, 40%, 50%, 60%, 80%, and 100% (by volume). Flexural tests of RC beams were conducted by a four-point loading test, where the deflection behavior of the beams was monitored through three linear variable displacement transducers (LVDT). The compressive strength and durability properties (i.e., porosity, resistance to chloride ion penetration, and capillary water absorption) were assessed using the same batch of concrete mix used to cast RC beams. The experimental results have shown that the flexural load of RC beams made with IFSSA was significantly higher than the control beam (100% FCBA). The increment of the flexural load was proportional to the content of IFSSA, with an increase of 27% for the beam made with 80% IFSSA than the control beam. The compressive strength of concrete increased by 56% and 61% for the concrete made with 80% and 100% IFSSA, respectively, than the control concrete, which is in good agreement with the flexural load of RC beams. Furthermore, the porosity, resistance to chloride ion penetration, and capillary water absorption were inversely proportional to the increase in the content of IFSSA. For instance, porosity, chloride penetration, and water absorption decreased by 43%, 54%, and 68%, respectively, when IFSSA entirely replaced FCBA. This decreasing percentage of durability properties is in agreement with the flexural load of RC beams. A good linear relationship of porosity with chloride penetration resistance and capillary water absorption was observed.

Monophasic and homogeneous Ni 10 Zr 7 nanocrystalline alloy films were successfully grown at room temperature by co-sputtering in an indigenously developed three-gun DC/RF magnetron sputtering unit. The films could be produced with long-range crystallographic and chemical order in the alloy, thus overcoming the widely acknowledged inherent proclivity of the glass forming Ni–Zr couple towards amorphization. Crystallinity of these alloys is a desirable feature with regard to improved efficacy in applications such as hydrogen storage, catalytic activity and nuclear reactor engineering, to name a few. Thermal stability of this crystalline phase, being vital for transition to viable applications, was investigated through systematic annealing of the alloy films at 473 K, 673 K and 923 K for various durations. While the films were stable at 473 K, the effect of annealing at 673 K was to create segregation into nanocrystalline Ni (superparamagnetic) and amorphous Ni + Zr (non-magnetic) phases. Detailed analyses of the physical and magnetic structures before and after annealing were performed through several techniques effectual in analyzing stratified configurations and the findings were all consistent with each other. Polarized neutron and X-ray reflectometry, grazing incidence x-ray diffraction, time-of-flight secondary ion mass spectroscopy and X-ray photoelectron spectroscopy were used to gauge phase separation at nanometer length scales. SQUID based magnetometry was used to investigate macroscopic magnetic properties. Simulated annealing performed on this system using molecular dynamic calculations corroborated well with the experimental results. This study provides a thorough understanding of the creation and thermal evolution of a crystalline Ni–Zr alloy.

The Alt Right Are Not Alright Academic explorations complicating both the Internet and whiteness have often focussed on the rise of the “alt-right” to examine the co-option of digital technologies to extend white supremacy (Daniels, “Cyber Racism”; Daniels, “Algorithmic Rise”; Nagle). The term “alt-right” refers to media organisations, personalities, and sarcastic Internet users who promote the “alternative right”, understood as extremely conservative, political views online. The alt-right, in all of their online variations and inter-grouping, are infamous for supporting white supremacy online, “characterized by heavy use of social media and online memes. Alt-righters eschew ‘establishment’ conservatism, skew young, and embrace white ethnonationalism as a fundamental value” (Southern Poverty Law Center). Theoretical studies of the alt-right have largely focussed on its growing presence across social media and websites such as Twitter, Reddit, and notoriously “chan” sites 4chan and 8chan, through the political discussions referred to as “threads” on the site (Nagle; Daniels, “Algorithmic Rise”; Hawley). As well, the ability of online users to surpass national boundaries and spread global white supremacy through the Internet has also been studied (Back et al.). The alt-right have found a home on the Internet, using its features to cunningly recruit members and to establish a growing community that mainstream politically extreme views (Daniels, “Cyber Racism”; Daniels, “Algorithmic Rise; Munn). This body of knowledge shows that academics have been able to produce critically relevant literature regarding the alt-right despite the online anonymity of the majority of its members. For example, Conway et al., in their analysis of the history and social media patterns of the alt-right, follow the unique nature of the Christchurch Massacre, encompassing the use and development of message boards, fringe websites, and social media sites to champion white supremacy online. Positioning my research in this literature, I am interested in contributing further knowledge regarding the alt-right, white supremacy, and the Internet by exploring the sinister conducting of Zoom-bombing anti-racist events. Here, I will investigate how white supremacy through the Internet can lead to violence, abuse, and fear that “transcends the virtual world to damage real, live humans beings” via Zoom-bombing, an act that is situated in a larger co-option of the Internet by the alt-right and white supremacists, but has been under theorised as a hate crime (Daniels; “Cyber Racism” 7). Shitposting I want to preface this chapter by acknowledging that while I understand the Internet, through my own external investigations of race, power and the Internet, as a series of entities that produce racial violence both online and offline, I am aware of the use of the Internet to frame, discuss, and share anti-racist activism. Here we can turn to the work of philosopher Michel de Certeau who conceived the idea of a “tactic” as a way to construct a space of agency in opposition to institutional power. This becomes a way that marginalised groups, such as racialised peoples, can utilise the Internet as a tactical material to assert themselves and their non-compliance with the state. Particularly, shitposting, a tactic often associated with the alt-right, has also been co-opted by those who fight for social justice and rally against oppression both online and offline. As Roderick Graham explores, the Internet, and for this exploration, shitposting, can be used to proliferate deviant and racist material but also as a “deviant” byway of oppositional and anti-racist material. Despite this, a lot can be said about the invisible yet present claims and support of whiteness through Internet and digital technologies, as well as the activity of users channelled through these screens, such as the alt-right and their digital tactics. As Vikki Fraser remarks, “the internet assumes whiteness as the norm – whiteness is made visible through what is left unsaid, through the assumption that white need not be said” (120). It is through the lens of white privilege and claims to white supremacy that online irony, by way of shitposting, is co-opted and understood as an inherently alt-right tool, through the deviance it entails. Their sinister co-option of shitposting bolsters audacious claims as to who has the right to exist, in their support of white identity, but also hides behind a veil of mischief that can hide their more insidious intention and political ideologies. The alt-right have used “shitposting”, an online style of posting and interacting with other users, to create a form of online communication for a translocal identity of white nationalist members. Sean McEwan defines shitposting as “a form of Internet interaction predicated upon thwarting established norms of discourse in favour of seemingly anarchic, poor quality contributions” (19). Far from being random, however, I argue that shitposting functions as a discourse that is employed by online communities to discuss, proliferate, and introduce white supremacist ideals among their communities as well as into the mainstream. In the course of this article, I will introduce racist Zoom-bombing as a tactic situated in shitposting which can be used as a means of white supremacist discourse and an attempt to block anti-racist efforts. By this line, the function of discourse as one “to preserve or to reproduce discourse (within) a closed community” is calculatingly met through shitposting, Zoom-bombing, and more overt forms of white supremacy online (Foucault 225-226). Using memes, dehumanisation, and sarcasm, online white supremacists have created a means of both organising and mainstreaming white supremacy through humour that allows insidious themes to be mocked and then spread online. Foucault writes that “in every society the production of discourse is at once controlled, selected, organised and redistributed according to a certain number of procedures, whose role is to avert its powers and danger, to cope with chance events, to evade ponderous, awesome materiality” (216). As Philippe-Joseph Salazar recontextualises to online white supremacists, “the first procedure of control is to define what is prohibited, in essence, to set aside that which cannot be spoken about, and thus to produce strategies to counter it” (137). By this line, the alt-right reorganises these procedures and allocates a checked speech that will allow their ideas to proliferate in like-minded and growing communities. As a result, online white supremacists becoming a “community of discourse” advantages them in two ways: first, ironic language permits the mainstreaming of hate that allows sinister content to enter the public as the severity of their intentions is doubted due to the sarcastic language employed. Second, shitposting is employed as an entry gate to more serious and dangerous participation with white supremacist action, engagement, and ideologies. It is important to note that white privilege is embodied in these discursive practices as despite this exploitation of emerging technologies to further white supremacy, there are approaches that theorise the alt-right as “crazed product(s) of an isolated, extremist milieu with no links to the mainstream” (Moses 201). In this way, it is useful to consider shitposting as an informal approach that mirrors legitimised white sovereignties and authorised white supremacy. The result is that white supremacist online users succeed in “not only in assembling a community of actors and a collective of authors, on the dual territory of digital communication and grass-roots activism”, but also shape an effective fellowship of discourse that audiences react well to online, encouraging its reception and mainstreaming (Salazar 142). Continuing, as McBain writes, “someone who would not dream of donning a white cap and attending a Ku Klux Klan meeting might find themselves laughing along to a video by the alt-right satirist RamZPaul”. This idea is echoed in a leaked stylistic guide by white supremacist website and message board the Daily Stormer that highlights irony as a cultivated mechanism used to draw new audiences to the far right, step by step (Wilson). As showcased in the screen capture below of the stylistic guide, “the reader is at first drawn in by curiosity or the naughty humor and is slowly awakened to reality by repeatedly reading the same points” (Feinburg). The result of this style of writing is used “to immerse recruits in an online movement culture built on memes, racial panic and the worst of Internet culture” (Wilson). Figure 1: A screenshot of the Daily Stormer’s playbook, expanding on the stylistic decisions of alt-right writers. Racist Zoom-Bombing In the timely text “Racist Zoombombing”, Lisa Nakamura et al. write the following: Zoombombing is more than just trolling; though it belongs to a broad category of online behavior meant to produce a negative reaction, it has an intimate connection with online conspiracy theorists and white supremacy … . Zoombombing should not be lumped into the larger category of trolling, both because the word “trolling” has become so broad it is nearly meaningless at times, and because zoombombing is designed to cause intimate harm and terrorize its target in distinct ways. (30) Notwithstanding the seriousness of Zoom-bombing, and to not minimise its insidiousness by understanding it as a form of shitposting, my article seeks to reiterate the seriousness of shitposting, which, in the age of COVID-19, Zoom-bombing has become an example of. I seek to purport the insidiousness of the tactical strategies of the alt-right online in a larger context of white violence online. Therefore, I am proposing a more critical look at the tactical use of the Internet by the alt-right, in theorising shitposting and Zoom-bombing as means of hate crimes wherein they impose upon anti-racist activism and organising. Newlands et al., receiving only limited exposure pre-pandemic, write that “Zoom has become a household name and an essential component for parties (Matyszczyk, 2020), weddings (Pajer, 2020), school and work” (1). However, through this came the strategic use of co-opting the application by the alt-right to digitise terror and ensure a “growing framework of memetic warfare” (Nakamura et al. 31). Kruglanski et al. label this co-opting of online tools to champion white supremacy operations via Zoom-bombing an example of shitposting: Not yet protesting the lockdown orders in front of statehouses, far-right extremists infiltrated Zoom calls and shared their screens, projecting violent and graphic imagery such as swastikas and pornography into the homes of unsuspecting attendees and making it impossible for schools to rely on Zoom for home-based lessons. Such actions, known as “Zoombombing,” were eventually curtailed by Zoom features requiring hosts to admit people into Zoom meetings as a default setting with an option to opt-out. (128) By this, we can draw on existing literature that has theorised white supremacists as innovation opportunists regarding their co-option of the Internet, as supported through Jessie Daniels’s work, “during the shift of the white supremacist movement from print to digital online users exploited emerging technologies to further their ideological goals” (“Algorithmic Rise” 63). Selfe and Selfe write in their description of the computer interface as a “political and ideological boundary land” that may serve larger cultural systems of domination in much the same way that geopolitical borders do (418). Considering these theorisations of white supremacists utilising tools that appear neutral for racialised aims and the political possibilities of whiteness online, we can consider racist Zoom-bombing as an assertion of a battle that seeks to disrupt racial justice online but also assert white supremacy as its own legitimate cause. My first encounter of local Zoom-bombing was during the Institute for Culture and Society (ICS) Seminar titled “Intersecting Crises” by Western Sydney University. The event sought to explore the concatenation of deeply inextricable ecological, political, economic, racial, and social crises. An academic involved in the facilitation of the event, Alana Lentin, live tweeted during the Zoom-bombing of the event: Figure 2: Academic Alana Lentin on Twitter live tweeting the Zoom-bombing of the Intersecting Crises event. Upon reflecting on this instance, I wondered, could efforts have been organised to prevent white supremacy? In considering who may or may not be responsible for halting racist shit-posting, we can problematise the work of R David Lankes, who writes that “Zoom-bombing is when inadequate security on the part of the person organizing a video conference allows uninvited users to join and disrupt a meeting. It can be anything from a prankster logging on, yelling, and logging off to uninvited users” (217). However, this beckons two areas to consider in theorising racist Zoom-bombing as a means of isolated trolling. First, this approach to Zoom-bombing minimises the sinister intentions of Zoom-bombing when referring to people as pranksters. Albeit withholding the “mimic trickery and mischief that were already present in spaces such as real-life classrooms and town halls” it may be more useful to consider theorising Zoom-bombing as often racialised harassment and a counter aggression to anti-racist initiatives (Nakamura et al. 30). Due to the live nature of most Zoom meetings, it is increasingly difficult to halt the threat of the alt-right from Zoom-bombing meetings. In “A First Look at Zoom-bombings” a range of preventative strategies are encouraged for Zoom organisers including “unique meeting links for each participant, although we acknowledge that this has usability implications and might not always be feasible” (Ling et al. 1). The alt-right exploit gaps, akin to co-opting the mainstreaming of trolling and shitposting, to put forward their agenda on white supremacy and assert their presence when not welcome. Therefore, utilising the pandemic to instil new forms of terror, it can be said that Zoom-bombing becomes a new means to shitpost, where the alt-right “exploits Zoom’s uniquely liminal space, a space of intimacy generated by users via the relationship between the digital screen and what it can depict, the device’s audio tools and how they can transmit and receive sound, the software that we can see, and the software that we can’t” (Nakamura et al. 29). Second, this definition of Zoom-bombing begs the question, is this a fair assessment to write that reiterates the blame of organisers? Rather, we can consider other gaps that have resulted in the misuse of Zoom co-opted by the alt-right: “two conditions have paved the way for Zoom-bombing: a resurgent fascist movement that has found its legs and best megaphone on the Internet and an often-unwitting public who have been suddenly required to spend many hours a day on this platform” (Nakamura et al. 29). In this way, it is interesting to note that recommendations to halt Zoom-bombing revolve around the energy, resources, and attention of the organisers to practically address possible threats, rather than the onus being placed on those who maintain these systems and those who Zoom-bomb. As Jessie Daniels states, “we should hold the platform accountable for this type of damage that it's facilitated. It's the platform's fault and it shouldn't be left to individual users who are making Zoom millions, if not billions, of dollars right now” (Ruf 8). Brian Friedberg, Gabrielle Lim, and Joan Donovan explore the organised efforts by the alt-right to impose on Zoom events and disturb schedules: “coordinated raids of Zoom meetings have become a social activity traversing the networked terrain of multiple platforms and web spaces. Raiders coordinate by sharing links to Zoom meetings targets and other operational and logistical details regarding the execution of an attack” (14). By encouraging a mass coordination of racist Zoom-bombing, in turn, social justice organisers are made to feel overwhelmed and that their efforts will be counteracted inevitably by a large and organised group, albeit appearing prankster-like. Aligning with the idea that “Zoombombing conceals and contains the terror and psychological harm that targets of active harassment face because it doesn’t leave a trace unless an alert user records the meeting”, it is useful to consider to what extent racist Zoom-bombing becomes a new weapon of the alt-right to entertain and affirm current members, and engage and influence new members (Nakamura et al. 34). I propose that we consider Zoom-bombing through shitposting, which is within “the location of matrix of domination (white supremacy, heteropatriarchy, ableism, capitalism, and settler colonialism)” to challenge the role of interface design and Internet infrastructure in enabling racial violence online (Costanza-Chock). Conclusion As Nakamura et al. have argued, Zoom-bombing is indeed “part of the lineage or ecosystem of trollish behavior”, yet these new forms of alt-right shitposting “[need] to be critiqued and understood as more than simply trolling because this term emerged during an earlier, less media-rich and interpersonally live Internet” (32). I recommend theorising the alt-right in a way that highlights the larger structures of white power, privilege, and supremacy that maintain their online and offline legacies beyond Zoom, “to view white supremacy not as a static ideology or condition, but to instead focus on its geographic and temporal contingency” that allows acts of hate crime by individuals on politicised bodies (Inwood and Bonds 722). This corresponds with Claire Renzetti’s argument that “criminologists theorise that committing a hate crime is a means of accomplishing a particular type of power, hegemonic masculinity, which is described as white, Christian, able-bodied and heterosexual” – an approach that can be applied to theorisations of the alt-right and online violence (136). This violent white masculinity occupies a hegemonic hold in the formation, reproduction, and extension of white supremacy that is then shared, affirmed, and idolised through a racialised Internet (Donaldson et al.). Therefore, I recommend that we situate Zoom-bombing as a means of shitposting, by reiterating the severity of shitposting with the same intentions and sinister goals of hate crimes and racial violence. References Back, Les, et al. “Racism on the Internet: Mapping Neo-Fascist Subcultures in Cyber-Space.” Nation and Race: The Developing Euro-American Racist Subculture. Eds. Jeffrey Kaplan and Tore Bjørgo. Northeastern UP, 1993. 73-101. Bonds, Anne, and Joshua Inwood. “Beyond White Privilege: Geographies of White Supremacy and Settler Colonialism.” Progress in Human Geography 40 (2015): 715-733. Conway, Maura, et al. “Right-Wing Extremists’ Persistent Online Presence: History and Contemporary Trends.” The International Centre for Counter-Terrorism – The Hague. Policy Brief, 2019. Costanza-Chock, Sasha. “Design Justice and User Interface Design, 2020.” Proceedings of the 33rd Annual ACM Symposium on User Interface Software and Technology. Association for Computing Machinery, 2020. Daniels, Jessie. “The Algorithmic Rise of the ‘Alt-Right.’” Contexts 17 (2018): 60-65. ———. “Race and Racism in Internet Studies: A Review and Critique.” New Media & Society 15 (2013): 695-719. ———. Cyber Racism: White Supremacy Online and the New Attack on Civil Rights. Rowman and Littlefield, 2009. De Certeau, Michel. The Practice of Everyday Life. First ed. U of California P, 1980. Donaldson, Mike. “What Is Hegemonic Masculinity?” Theory and Society 22 (1993): 643-657. Feinburg, Ashley. “This Is The Daily Stormer’s Playbook.” Huffington Post 13 Dec. 2017. . Foucault, Michel. “The Discourse on Language.” The Archaeology of Knowledge and the Discourse on Language. Ed. A.M. Sheridan Smith. Pantheon, 1971. 215-237. Fraser, Vicki. “Online Bodies and Sexual Subjectivities: In Whose Image?” The Racial Politics of Bodies, Nations and Knowledges. Eds. Barbara Baird and Damien W. Riggs. Newcastle: Cambridge Scholars Publishing, 2015. 116-132. Friedberg, Brian, Gabrielle Lim, and Joan Donovan. “Space Invaders: The Networked Terrain of Zoom Bombing.” Harvard Shorenstein Center, 2020. Graham, Roderick. “Race, Social Media and Deviance.” The Palgrave Handbook of International Cybercrime and Cyberdeviance. Eds. Thomas J. Holt and Adam M. Bossler, 2019. 67-90. Hawley, George. Making Sense of the Alt-Right. Columbia UP, 2017. Henry, Matthew G., and Lawrence D. Berg. “Geographers Performing Nationalism and Hetero-Masculinity.” Gender, Place & Culture 13 (2006): 629-645. Kruglanski, Arie W., et al. “Terrorism in Time of the Pandemic: Exploiting Mayhem.” Global Security: Health, Science and Policy 5 (2020): 121-132. Lankes, R. David. Forged in War: How a Century of War Created Today's Information Society. Rowman & Littlefield, 2021. Ling, Chen, et al. “A First Look at Zoombombing, 2021.” Proceedings of the 42nd IEEE Symposium on Security and Privacy. Oakland, 2021. McBain, Sophie. “The Alt-Right, and How the Paranoia of White Identity Politics Fuelled Trump’s Rise.” New Statesman 27 Nov. 2017. . McEwan, Sean. “Nation of Shitposters: Ironic Engagement with the Facebook Posts of Shannon Noll as Reconfiguration of an Australian National Identity.” Journal of Media and Communication 8 (2017): 19-39. Morgensen, Scott Lauria. “Theorising Gender, Sexuality and Settler Colonialism: An Introduction.” Settler Colonial Studies 2 (2012): 2-22. Moses, A Dirk. “‘White Genocide’ and the Ethics of Public Analysis.” Journal of Genocide Research 21 (2019): 1-13. Munn, Luke. “Algorithmic Hate: Brenton Tarrant and the Dark Social Web.” VoxPol, 3 Apr. 2019. . Nagle, Angela. Kill All Normies: Online Culture Wars from 4chan and Tumblr to Trump and the Alt-Right. Zero Books, 2017. Nakamura, Lisa, et al. Racist Zoom-Bombing. Routledge, 2021. Newlands, Gemma, et al. “Innovation under Pressure: Implications for Data Privacy during the COVID-19 Pandemic.” Big Data & Society July-December (2020): 1-14. Perry, Barbara, and Ryan Scrivens. “White Pride Worldwide: Constructing Global Identities Online.” The Globalisation of Hate: Internationalising Hate Crime. Eds. Jennifer Schweppe and Mark Austin Walters. Oxford UP, 2016. 65-78. Renzetti, Claire. Feminist Criminology. Routledge, 2013. Ruf, Jessica. “‘Spirit-Murdering' Comes to Zoom: Racist Attacks Plague Online Learning.” Issues in Higher Education 37 (2020): 8. Salazar, Philippe-Joseph. “The Alt-Right as a Community of Discourse.” Javnost – The Public 25 (2018): 135-143. Selfe, Cyntia L., and Richard J. Selfe, Jr. “The Politics of the Interface: Power and Its Exercise in Electronic Contact Zones.” College Composition and Communication 45 (1994): 480-504. Southern Poverty Law Center. “Alt-Right.” . Wilson, Jason. “Do the Christchurch Shootings Expose the Murderous Nature of ‘Ironic’ Online Fascism?” The Guardian, 16 Mar. 2019. .

The Fractional Open-Circuit Voltage (FOCV) based Maximum Power Point Tracking (MPPT) method, typically used in low power energy harvesting circuits, is not truly dynamic and wastes harvestable energy in each MPPT cycle. Commercial-off-the-shelf (COTS) energy harvesting chips offer provision for externally setting the MPPT reference using more accurate and dynamic algorithms like Perturb-and-Observe (P&O), Incremental Conductance (INC) etc., but this can come at the cost of increased power consumption and sensing complexity. To address this issue, a simple low power implementation of the P&O method in an energy harvesting wireless sensor node (WSN) is presented in this paper. With only two additional analog load switches (SOT23 package), and no extra current or voltage sensor, the proposed method achieves dynamic MPPT with a power overhead of only eight microwatts.

To understand the impacts of fertilizer treatment and ryegrass growth on the dynamic changes of soil water is essential to use available soil water and rainfall sagaciously and develop a sustainable artificial ryegrass land in Sichuan Basin area and the similar areas in the world. In the current research, the dynamic changes of soil water were measured under different nitrogen fertilizer treatments by field experiment and EPIC model (Environment Policy Integrated Climate) simulation in the hilly region of Sichuan Basin area from 2011 to 2015. Results revealed that the EPIC model simulated the dynamic changes of soil water well, as the simulated and observed values of forage yield, leaf area index and ryegrass height exhibited a good correlation. When the nitrogen fertilizer was 150 kg/hm2 the soil water consumed by ryegrass during January to May period recovered well during June to September, it is more sustainable treatment than other experimental treatments, considering in a long period. Furthermore, our simulation demonstrated that the roots especially distributed in 0–50 cm soil has a significant effect on available soil water in 0–1 m soil. Root distributed in 0–20 cm and 60–100 cm soil affected the available soil water in 0–50 cm and 60–100 cm soil respectively.

Induction furnace steel slag is a secondary product obtained when molten steel is separated from the impurities in the steel-producing furnaces. Though numerous studies have been published on the mechanical strength of concrete/mortar made with steel slag as fine aggregate, relatively few studies focus on the shrinkage, durability (i.e., porosity, water absorption, and resistance to chloride penetration) at ambient temperature, and especially the mechanical and durability performances after exposure to elevated temperatures. Within this context, the present study investigates mechanical strength, shrinkage, and durability of mortar made with different contents of steel slag powder (SSP) at two different water-to-cement (w/c) ratios before and after exposure to elevated temperatures (120, 250, 400 and 600 °C). Mortars made with SSP showed significantly higher mechanical strength and better durability than mortar made with 100% natural sand (control mortar). Compressive, tensile, and flexural strength increased by 45%, 72% and 56%, respectively, when SSP entirely replaced natural sand. Porosity, water absorption, and chloride penetration decreased by 42%, 61% and 52%, respectively, for 100% SSP mortar. Furthermore, the shrinkage of the mortar decreased with increasing percentages of SSP. Conversely, residual compressive strength after heat exposure was lower for 100% SSP mortar than for the control mortar. Therefore, this study presents a first step towards the successful utilization of SSP in cementitious mortar.

This paper presents a bidirectional CLLC converter solution for the dc-dc stage in plug-in electric vehicle (PEV) on-board battery chargers. The proposed architecture allows the converter to operate at resonance for the bidirectional constant-power (CP) load range with a variable bus voltage, while frequency modulation is employed for the constant-current (CC) load range in the grid-to-vehicle (G2V) mode with a fixed bus voltage, resulting in a limited bus voltage range. This enables the use of 650-V Gallium nitride (GaN) devices for the primary and secondary sides’ switches. The design flow is presented and a 1-kW high-frequency prototype is implemented. GaN reverse conduction characteristics are investigated and employed for the high-frequency current rectification. The prototype operates with soft switching across the operational range, achieving an efficiency of up to 95.7%, with the resonant inductances integrated in the transformer.

This study evaluates the mechanical, durability, and residual compressive strength (after being exposed to 20, 120, 250, 400 and 600 &deg, C) of mortar that uses recycled iron powder (RIP) as a fine aggregate. Within this context, mechanical strength, shrinkage, durability, and residual strength tests were performed on mortar made with seven different percentages (0%, 5%, 10%, 15%, 20%, 30% and 50%) of replacement of natural sand (NS) by RIP. It was found that the mechanical strength of mortar increased when replaced with up to 30% NS by RIP. In addition, the increase was 30% for compressive, 18% for tensile, and 47% for flexural strength at 28 days, respectively, compared to the reference mortar (mortar made with 100% NS). Shrinkage was observed for the mortar made with 100% NS, while both shrinkage and expansion occurred in the mortar made with RIP, especially for RIP higher than 5%. Furthermore, significantly lower porosity and capillary water absorption were observed for mortar made with up to 30% RIP, compared to that made with 100% NS, which decreased by 36% for porosity and 48% for water absorption. As the temperature increased, the strength decreased for all mixes, and the drop was more pronounced for the temperatures above 250 &deg, C and 50% RIP. This study demonstrates that up to 30% RIP can be utilized as a fine aggregate in mortar due to its better mechanical and durability performances.

Researchers and scientists have agreed upon a commitment to lower greenhouse gases (GHG) emission values by 40–70% compared to 2010 values and to keep the temperature rise at 1.5 °C by mid-century. Several proposed solutions have been put forward by scientific community to fulfill this commitment. Biochar is an emerging solution to problems relating soil and environmental degradation due post green revolution measures taken by humanity to boost agricultural production. Being rich in carbon and having greater stability, biochar has several benefiting properties such as surface area, porosity, water holding capacity, adsorption capacity, and cation exchange capacity that may persist for decades or even centuries. These properties greatly help in sustainably maintaining soil and environmental health and increasing crop production. Besides, biochar has been proven to have great carbon sequestration capacity. Biochar in its original form and after physical or chemical activation has been found to be an excellent CO2 adsorbent with stable recyclability and regeneration. It also increases soil aeration, hence decreasing the activities of methanogens and consequently reducing methane emissions. Biochar increases the C:N ratio of the soil which according to several researchers may help reduce nitrous oxide emissions from the soil. Biochar has also been proven an effective sorbent for organic and inorganic wastes including heavy metals and pesticides. This sorbent capacity of biochar comes from its greater surface area and microporosity which can be further increased by techniques employed during pyrolysis. In its climate change mitigation efforts, biochar is a suitable alternative to fossil fuel driven energy production. Biochar has been used in the production of clean energy sources such as for sorption of hydrogen, development of super capacitors, as solid acid catalyst for biodiesel production and as cathodes in fuel cell systems such as Direct Carbon Fuel Cell (DCFC) and Microbial Fuel Cell (MFC). This chapter provides with ample examples from previous and ongoing studies that makes biochar a potential candidate among solutions being put forward by scientific community to mitigate the adverse effects of climate change.

Fe23Zr6 intermetallic phase is formed in SS-15Zr alloy which is a promising material for high level metallic waste immobilization. We have studied thethermodynamic properties, viz., specific heat at constant volume (CV), entropy (S) and vibrational Helmholtz free energy (Fvib) of Fe23Zr6 phase as a function of pressure and temperature using density functional theory. The phase is found to be dynamically stable and increase of temperature or decrease of pressure makes the phase more stable. Constant volume specific heat (CV) of the phase at high temperatures (T > 500 K) does not change with temperature.

Structural and electronic properties of c-Fe 2 Zr, t-FeZr 2 and o-FeZr 3 intermetallic phases in the presence of s-, p- and d -block fission metals (FMs), viz., Rb, Sr, In, Sn, Sb, Te, Cs, Ba, Y, Nb, Mo, Tc, Ru, Rh, Pd, Ag and Cd are studied using density functional theory (DFT). The mono-vacancy and di-vacancy formation energies of Fe and Zr in these intermetallics are also calculated. It has been found that s -block FMs are less weakly bounded to the intermetallics than the p − and d − block FMs. The solution energies of p − and d − block fission atoms are either slightly positive or negative. The high solution energies of s-block FMs suggest that these FMs are highly insoluble in the Fe-Zr intermetallics. The solution energy hierarchy of the FMs follow the trend as Cs > Rb > Ba > Sr > Ag > Cd > Y > Mo > Nb > In > Te > Sn > Tc > Sb > Pd > Ru > Rh. We also report the site preferences of these FMs in Fe-Zr intermetallics based on their incorporation/solution energies. The electronic property analysis indicate a predominant metallic bonding with small covalent and ionic contributions. Finally, these intermetallics have been compared in terms of their potentials to accommodate these FMs.

The nine-switch converter is a multiport converter having two three-phase terminals and a dc-link, just like a 12-switch back-to-back (BTB) converter, but with 25% reduction of active switch count. However, the reduction from 12-switch to 9-switch may not always be an efficient choice considering losses in the switches. Only the load–source combination for the ac–ac common frequency mode and the source–source combination for the ac–dc different frequency (ac–dc DF) mode have been reported, so far, to yield relatively lower loss for the nine-switch converter. This paper shows that the nine-switch converter can have relatively lower loss even with a load–source combination, instead of only source–source combination in its ac–dc DF mode—when the upper terminal is connected to a dc load and the lower terminal is connected to an ac source. Mathematical proof is presented with derivation of the particular operating parameters for which the nine-switch converter will have comparatively lower losses. The analysis is validated with simulation and experimental results of a 1-kW system. Finally, the benchmark of the application criteria of the nine-switch converter for having lower conduction loss than the BTB converter is updated in this paper.

Polymorphic transformations in LaPO4 are investigated as a function of pressure using density functional theory (DFT) based calculations under the generalized gradient approximation. The monazite-type (P21/n) → barite-type (Pbnm) structural transformation is identified at 16.2 GPa and experimentally, no transformation is observed near this pressure. A discontinuity in the pressure-volume relation (of 4.16% volume discontinuity compared to the monazite structure at the same pressure) and unit-cell dimensions is observed around 28 GPa, which matches well with the previous experimental results. The pressure of discontinuity matches the DFT calculated monazite-type (P21/n) → post barite-type (P212121) structural transformation pressure. The equation of state, single crystal elastic constants and phonon dispersion curves of the different polymorphs as a function of pressure are determined. Both the barite-type (Pbnm) and post barite-type (P212121) structures are mechanically and dynamically stable at 27 GPa indicating that the monazite-type (P21/n) → barite-type (Pbnm) phase transformation may be hindered by a kinetic barrier. The phase transformation in monazite-type LaPO4 is driven by a softening of the C25 single crystal elastic constant. Moreover, a small displacement and tilting of PO4 tetrahedra as a function of pressure leads to a change in the La chemical environment and creates space for the construction of LaO12 polyhedra from LaO9 due to a phase transformation.

Structural, mechanical and thermal properties of θ-Fe 3 C cementite, o-Fe 7 C 3 and h-Fe 7 C 3 , the common carbides in steels and earth's inner core, are calculated upto 450 GPa pressure and 2000 K temperature range using classical molecular dynamic (MD) simulations. A thorough evaluation of phase stability and elastic properties of several iron-carbides (γ′-FeC, η-Fe 2 C, ζ-Fe 2 C, h-Fe 7 C 3 , o-Fe 7 C 3 , χ-Fe 5 C 2 , θ-Fe 3 C, γ′-Fe 4 C, γ″-Fe 4 C and α′-F 16 C 2 ) is performed using four MD potentials (namely, MEAM, Tersoff and EAM/FS) for broad comparison of these potentials at static condition. The MD calculated pressure-volume, pressure-elastic constants and volume-temperature relations for θ-Fe 3 C, o-Fe 7 C 3 and h-Fe 7 C 3 phases are thoroughly compared with available experimental and first principles calculated values to assess the range of applicability and deficiencies of these interatomic potentials. Our enthalpy calculations suggest that o-Fe 7 C 3 is more stable than Eckstrom-Adcock hexagonal iron carbide (h-Fe 7 C 3 ) upto 450 GPa and 2000 K (Earth's core condition) which is in agreement with recent experiment. Our MD calculated longitudinal sound velocities match well with experiments (within 2%) upto 75 GPa and starts deviating from Birch's law at high pressures due to nonlinear interaction of phonon modes. The MD calculated pressure-volume-temperature relation of θ-Fe 3 C phase reproduces experimental values and pressure-volume-temperature relation of o-Fe 7 C 3 phase is predicted upto 200 GPa and 2000 K. The MD calculated melting temperatures of θ-Fe 3 C and Fe 7 C 3 using two-phase simulations match well with experimental values within their errorbars at 50 GPa and higher pressures.

Low and declining soil organic matter contents pose a significant threat to soil fertility, crop productivity and economic returns in arid and semi-arid agroecosystems. Holistic approaches are required to build and sustain soil organic matter in such soils to enhance nutrient use efficiencies and meet food security. Biochar is emerging as an attractive option for multiple benefits to soil-plant systems and carbon sequestration, especially in low fertility soils. We conducted a two-year maize-wheat rotation field experiments during 2015 and 2016 to test the effects of biochar on crop productivity, soil properties and phosphorous use efficiency (PUE) when applied with organic P sources as either farmyard manure (FYM) or poultry manure (PM) and diammonium phosphate (DAP) chemical fertilizer. Biochar was applied at two rates (0 and 10 t ha −1 ) whereas percentage of organic-inorganic P sources were 0, 25, 50 and 100% respectively. Biochar and manures were incorporated only once at the start of the field experiments whereas chemical fertilizers were applied during each crop cycle. Analysis of the two-year data revealed that biochar and P sources significantly and positively changed crop and soil quality attributes. Application of biochar significantly increased biological and grain yields of maize and wheat, soil organic carbon (SOC), and available nitrogen (N) and P contents without any negative effects on soil pH and electrical conductivity (EC). Addition of 50% P each from organic (FYM or PM) and chemical fertilizer increased biological and grain yields of maize, however, wheat biological and grain yields were higher with 100% PM or FYM in the presence of biochar. SOC and P contents were the highest when biochar was integrated with 100% P from FYM under maize crop. Biochar enhanced PUE from organic P sources more than the chemical fertilizer for both crops. Grain and biological yields of both crops correlated positively with SOC, soil N and soil P contents. We also found strong correlations between SOC, PUE and harvest index (HI) suggesting the benefits of increasing SOC contents under biochar-related integrated nutrient management practices. Overall results from these field experiments indicate potential of biochar to enhance plant nutrition, crop productivity and soil quality in nutrient poor alkaline calcareous soil under maize-wheat cropping system. Long-term farmers’ participatory field experiments, however, are required to extrapolate the potential of biochar integrations into current cereal-based cropping systems of Pakistan.

Three-phase power factor correction rectifiers followed by a dc–dc isolated converter are widely used for conversion of three-phase ac to isolated dc output used for high-power telecommunication loads. In this paper, a reduced device count nine-switch converter topology, which integrates the two stages of a conventional three-phase ac–dc power supply with an isolated dc output voltage for telecom applications is proposed. A novel modulation scheme using three separate 120 $^{\circ }$ phase-shifted high-frequency carriers for the three legs of the proposed converter is developed to drive the switches. It is shown that such modulation scheme leads to interleaved operation of the three dc–dc resonant converters integrated within the proposed topology resulting in low output dc voltage ripple. Justification is provided for the choice of the SiC MOSFET as the enabling technology for the converter. The proposed system with the modulation scheme is validated with a 1.5-kW laboratory prototype, which meets the Energy Star 80PLUS platinum efficiency standard for all loads.

We report plane-wave based density functional theory (DFT) investigation of structural, elastic and lattice dynamical properties of Fe-rich C15-Fe2Zr and Zr-rich FeZr2 intermetallic compounds. These intermetallics dominantly appear in the Fe-Zr alloys which are potential candidates for immobilization of nuclear metallic waste. The calculated elastic constants and phonon dispersions show that both phases are mechanically and dynamically stable. The calculated bulk moduli as a function of temperature show that the Fe-rich C15 phase is less compressible and also less sensitive to temperature than the Zr-rich C16 phase. Furthermore, the C15-Fe2Zr phase has a lower thermal expansion co-efficient but higher thermal conductivity as compared to the C16-FeZr2 phase; while the heat capacities (CP and CV) of both the phases are almost identical above 450 K.

This paper presents and examine a mathematical system of equations which describes the dynamics of pine wilt disease (PWD). Firstly, we examine the model with constant controls. Here, we investigate the disease equilibria and calculate the basic reproduction number of the disease. Secondly, we incorporate time dependent controls into the model and then analyze the conditions that are necessary for the disease to be controlled optimally. Finally, the numerical results for the model are presented.

In an asymmetrical pulse-width-modulated half-bridge (APWM HB) series resonant converter, an auxiliary LC network is provided for ensuring zero-voltage switching (ZVS) over a wide range of line and load variations. However, it comes at the cost of increased number of components and reduced efficiency and reliability. This paper presents a novel design methodology for the standard APWM HB resonant topology, which uses the magnetizing current and eliminates the need for extra components. The converter with the proposed design methodology operates at the resonant frequency of the tank and features load-independent ZVS for a wide range of input voltage variation with minimal magnetizing current. Empirical formulae are derived to design the resonant network and the magnetizing inductance of the high-frequency transformer systematically in a flowchart-based manner. The proposed design is validated by using simulations as well as experiments and is compared with a reference APWM HB series resonant converter design that uses an auxiliary LC circuit for ZVS. Two separate experimental prototypes of the two converters rated for 30 W, 48 V/5 V with a switching frequency of 500 kHz were built and tested in the laboratory. It was found that the converter with the proposed design methodology, apart from having lower component count, is about 3% more efficient than the reference topology at the rated power.

Atmospheric Particulate Matter (PM) is considered one of the most critical air pollutants in terms of its detrimental health impacts, environmental degradations and visibility. Particles size, their chemical composition and atmospheric levels are important factors for determining their adverse health impacts. In this paper various aspects of PM2.5 are analysed including PM2.5/PM10 ratios and association with meteorological parameters using data collected from January 2014 to September 2015 in Makkah Saudi Arabia. During the study period, mean PM2.5/PM10 ratio was found to be 0.64, whereas median and maximum ratios were 0.69 and 0.99, respectively. Diurnal, weekly and annual cycles of PM10, PM2.5 and their ratios were analysed, which demonstrated considerable variations during various hours of the day, days of the week and months of the year. PM2.5/PPM10 ratios were lower in summer (June and July) and higher in winter (November and December), likewise the ratios were lower during afternoon and higher in the morning and evening. As expected, there was a positive correlation between PM10 and PM2.5 (r = 0.51) and both PM10 and PM2.5 showed negative association with relative humidity and positive with wind speed and temperature. Furthermore, PM2.5/PM10 ratios were lower ( 0.70) at higher relative humidity (35–90%), indicating a shift towards high PM2.5 concentrations at higher relative humidity. Polar plots showed lowest ratios at high wind speed (> 3 m s–1) blowing from west and southwest direction in summer, and highest ratios at low wind speed (< 2 m s–1) in winter. Polar plots were successfully applied to show the interaction between various meteorological parameters and PM2.5/PM10 ratios. Further work on source apportionment and receptor modelling of PM is required to help develop air quality index and prepare an effective air quality plan for Makkah.

A high-frequency transformer isolated dc-dc converter with high step-up ratio (more than 10) is normally used to interface the low voltage (∼30V) photovoltaic (PV) modules with the high voltage (∼380V) distribution bus of the dc data center. The requirement of high step-up gain of voltage compromises the efficiency of this converter due to the increased conduction loss in the low voltage side of the transformer. This paper presents a GaN-based isolated dc-dc converter that achieves both high step-up voltage gain and high efficiency with minimal component count. The converter utilizes a half-bridge series-resonant circuit, with duty-ratio controlled pulse width modulation. A new equivalent circuit of the primary side network of the converter is proposed that determines the optimum values of magnetizing inductance and deadtime for minimizing circulating current without affecting the soft-switching of the switches. The design is verified with a 240W laboratory prototype. The experimental result proves the claimed advantages and demonstrates the California Energy Commission (CEC) efficiency of 96.03% and the European efficiency (EU) of 95.56%.

The nine-switch single-stage three-phase ac-dc isolated converter integrates a three-phase active front-end ac-dc converter and a three-phase high-frequency galvanically isolated dc-dc converter in one stage, leading to a device count reduction of 25% compared to an equivalent two-stage configuration. The advantage of the nine-switch converter can be truly realized if it can achieve similar efficiency and input current quality as a two-stage converter. In this article, a design methodology is proposed, which ensures zero-voltage switching of the bottom and the middle switches of the nine-switch converter for the entire line cycle and also reduces its input current total harmonic distortion below 5%. By implementing space vector pulsewidth modulation, the dc-link voltage of the nine-switch converter is reduced to the level of an equivalent two-stage converter. The analytical claims are verified with a 3-kW laboratory prototype operating at 400-V ac input, 800-V dc-link voltage, and 380-V isolated dc output voltage.

Declining soil quality is commonplace throughout Southern Asia and sustainable strategies are required to reverse this trend to ensure food security for future generations. One potential solution to halt this decline is the implementation of integrated nutrient management whereby inorganic fertilisers are added together with organic wastes. These organic materials, however, are often quickly broken down in soil and provide only a transitory improvement in soil quality. Biochar, which can potentially persist in soil for centuries, may offer a more permanent solution to this problem. To address this, we undertook a 2-year field trial to investigate the interactions between conventional NPK fertilisers, farmyard manure (FYM) and biochar in a maize cropping system. Biochar application to the nutrient poor soil increased maize yields after year one by approximately 20% although the yield increase was lower in the second year (ca. 12.5%). Overall, there was little difference in grain yield between the 25 t ha −1 and the 50 t ha −1 biochar treatments. In terms of soil quality, biochar addition increased levels of soil organic carbon, inorganic N, P and base cations and had no detrimental impact on pH and salinity in this calcareous soil. Overall, this field trial demonstrated the potential of biochar to induce short-term benefits in crop yield and soil quality in maize cropping systems although the long-term benefits remain to be quantified. From a management perspective, we also highlight potential conflicts in biochar availability and use, which may limit its adoption by small scale farming systems typical of Southern Asia.

Density functional theory (DFT) based first-principles investigation has been performed to study the cohesive, elastic and electronic properties of Fe–Zr binary intermetallics across the composition range. Our initial calibration of underlying DFT approximations provides good agreement of lattice parameters and bulk moduli with experimental results. Ground state stability analysis indicates C15-Fe2Zr Laves phase to be the most stable and t-FeZr2 to be more stable than c-FeZr2. All Fe–Zr intermetallics are mechanically stable as estimated from their calculated elastic constants. The calculated elastic moduli, in general, decrease with increasing Zr concentration. Anisotropies in bulk, shear and Young moduli are also presented. All the binary intermetallic phases exhibit G/B value of less than 0.57 and hence are ductile due to the presence of dominant metallic bonding arising from Fe d–Zr d interactions with a small component of covalent character.