bluuebunny/crossref_metadata_2025 huggingface dataset:
CO
2
-forced Late Miocene cooling and ecosystem reorganizations in East Asia
Authors: Wen Yixiong , Zhang Laiming , Holbourn Ann E. , Zhu Chenguang , Huntington Katharine W. , Jin Tianjie , Li Yalin , Wang Chengshan
Published: January 2023

In parallel with pronounced cooling in the oceans, vast areas of the continents experienced enhanced aridification and restructuring of vegetation and animal communities during the Late Miocene. Debate continues over whether
p
CO
2
-induced global cooling was the primary driver of this climate and ecosystem upheaval on land. Here we present an 8 to 5 Ma land surface temperatures (LST) record from East Asia derived from paleosol carbonate clumped isotopes and integrated with climate model simulations. The LST cooled by ~7 °C between 7.5 and 5.7 Ma, followed by rapid warming across the Miocene–Pliocene transition (5.5 to 5 Ma). These changes occurred synchronously with variations in alkenone and Mg/Ca-based sea surface temperatures and with hydroclimate and ecosystem shifts in East Asia, highlighting a global climate forcing mechanism. Our modeling experiments additionally demonstrate that
p
CO
2
-forced cooling would have altered moisture transfer and pathways and driven extensive aridification in East Asia. We, thus, conclude that the East Asian hydroclimate and ecosystem shift was primarily controlled by
p
CO
2
-forced global cooling between 8 and 5 Ma.
The sea spider
Pycnogonum litorale
overturns the paradigm of the absence of axial regeneration in molting animals
Authors: Brenneis Georg , Frankowski Karina , Maaß Laura , Scholtz Gerhard
Published: January 2023

Regenerative abilities and their evolution in the different animal lineages have fascinated generations of biologists. While some taxa are capable of restoring entire individuals from small body fragments, others can regrow only specific structures or lack structural regeneration completely. In contrast to many other protostomes, including the segmented annelids, molting animals (Ecdysozoa) are commonly considered incapable of primary body axis regeneration, which has been hypothesized to be linked to the evolution of their protective cuticular exoskeleton. This holds also for the extraordinarily diverse, segmented arthropods. Contradicting this long-standing paradigm, we here show that immatures of the sea spider
Pycnogonum litorale
reestablish the posterior body pole after transverse amputation and can regrow almost complete segments and the terminal body region, including the hindgut, anus, and musculature. Depending on the amputation level, normal phenotypes or hypomeric six-legged forms develop. Remarkably, also the hypomeric animals regain reproductive functionality by ectopic formation of gonoducts and gonopores. The discovery of such complex regenerative patterns in an extant arthropod challenges the hitherto widely assumed evolutionary loss of axial regeneration during ecdysozoan evolution. Rather, the branching of sea spiders at the base of Chelicerata and their likely ancestral anamorphic development suggests that the arthropod stem species may have featured similar regenerative capabilities. Accordingly, our results provide an incentive for renewed comparative regeneration studies across ecdysozoans, with the aim to resolve whether this trait was potentially even inherited from the protostome ancestor.
The microbiome stabilizes circadian rhythms in the gut
Authors: Zhang Yueliang , Li Yongjun , Barber Annika F. , Noya Sara B. , Williams Julie A. , Li Fu , Daniel Scott G. , Bittinger Kyle , Fang Jichao , Sehgal Amita
Published: January 2023

The gut microbiome is well known to impact host physiology and health. Given widespread control of physiology by circadian clocks, we asked how the microbiome interacts with circadian rhythms in the
Drosophila
gut. The microbiome did not cycle in flies fed ad libitum, and timed feeding (TF) drove limited cycling only in clockless

per
01

flies. However, TF and loss of the microbiome influenced the composition of the gut cycling transcriptome, independently and together. Moreover, both interventions increased the amplitude of rhythmic gene expression, with effects of TF at least partly due to changes in histone acetylation. Contrary to expectations, timed feeding rendered animals more sensitive to stress. Analysis of microbiome function in circadian physiology revealed that germ-free flies reset more rapidly with shifts in the light:dark cycle. We propose that the microbiome stabilizes cycling in the host gut to prevent rapid fluctuations with changing environmental conditions.
Loss of the E3 ubiquitin ligases UBR-5 or HECD-1 restoresCaenorhabditis elegansdevelopment in the absence of SWI/SNF function
Authors: Lampersberger Lisa , Conte Francesca , Ghosh Subhanita , Xiao Yutong , Price Jonathan , Jordan David , Matus David Q. , Sarkies Peter , Beli Petra , Miska Eric A. , Burton Nicholas O.
Published: January 2023

SWItch/sucrose non-fermenting (SWI/SNF) complexes are a family of chromatin remodelers that are conserved across eukaryotes. Mutations in subunits of SWI/SNF cause a multitude of different developmental disorders in humans, most of which have no current treatment options. Here, we identify an alanine-to-valine–causing mutation in the SWI/SNF subunitsnfc-5(SMARCB1in humans) that prevents embryonic lethality inCaenorhabditis elegansnematodes harboring a loss-of-function mutation in the SWI/SNF subunitswsn-1(SMARCC1/2in humans). Furthermore, we found that the combination of this specific mutation insnfc-5and a loss-of-function mutation in either of the E3 ubiquitin ligasesubr-5(UBR5in humans) orhecd-1(HECTD1in humans) can restore development to adulthood inswsn-1loss-of-function mutants that otherwise die as embryos. Using these mutant models, we established a set of 335 genes that are dysregulated in SWI/SNF mutants that arrest their development embryonically but exhibit near wild-type levels of expression in the presence of suppressor mutations that prevent embryonic lethality, suggesting that SWI/SNF promotes development by regulating some subset of these 335 genes. In addition, we show that SWI/SNF protein levels are reduced inswsn-1; snfc-5double mutants and partly restored to wild-type levels inswsn-1; snfc-5; ubr-5triple mutants, consistent with a model in which UBR-5 regulates SWI/SNF levels by tagging the complex for proteasomal degradation. Our findings establish a link between two E3 ubiquitin ligases and SWI/SNF function and suggest that UBR5 and HECTD1 could be potential therapeutic targets for the many developmental disorders caused by missense mutations in SWI/SNF subunits.
How to unravel a basket: NPC reorganization during meiosis
Authors: Veldsink Annemiek C. , Veenhoff Liesbeth M.
Published: January 2023

While our understanding of the nuclear pore complex (NPC) structure is progressing spectacularly, the organizational principles of its nuclear basket remain elusive. In this issue, King et al. (2022. J. Cell Biol.https://doi.org/10.1083/jcb.202204039) provide new insights into the mechanisms that govern nuclear basket reorganization during meiosis.
PD-1 blockade and CDK4/6 inhibition augment nonoverlapping features of T cell activation in cancer
Authors: Ali Lestat R. , Garrido-Castro Ana C. , Lenehan Patrick J. , Bollenrucher Naima , Stump Courtney T. , Dougan Michael , Goel Shom , Shapiro Geoffrey I. , Tolaney Sara M. , Dougan Stephanie K.
Published: January 2023

We performed single-cell RNA-sequencing and T cell receptor clonotype tracking of breast and ovarian cancer patients treated with the CDK4/6 inhibitor ribociclib and PD-1 blockade. We highlight evidence of two orthogonal treatment-associated phenomena: expansion of T cell effector populations and promotion of T cell memory formation. Augmentation of the antitumor memory pool by ribociclib boosts the efficacy of subsequent PD-1 blockade in mouse models of melanoma and breast cancer, pointing toward sequential therapy as a potentially safe and synergistic strategy in patients.
Immune-interacting lymphatic endothelial subtype at capillary terminals drives lymphatic malformation
Authors: Petkova Milena , Kraft Marle , Stritt Simon , Martinez-Corral Ines , Ortsäter Henrik , Vanlandewijck Michael , Jakic Bojana , Baselga Eulàlia , Castillo Sandra D. , Graupera Mariona , Betsholtz Christer , Mäkinen Taija
Published: January 2023

Oncogenic mutations in PIK3CA, encoding p110α-PI3K, are a common cause of venous and lymphatic malformations. Vessel type–specific disease pathogenesis is poorly understood, hampering development of efficient therapies. Here, we reveal a new immune-interacting subtype of Ptx3-positive dermal lymphatic capillary endothelial cells (iLECs) that recruit pro-lymphangiogenic macrophages to promote progressive lymphatic overgrowth. Mouse model of Pik3caH1047R-driven vascular malformations showed that proliferation was induced in both venous and lymphatic ECs but sustained selectively in LECs of advanced lesions. Single-cell transcriptomics identified the iLEC population, residing at lymphatic capillary terminals of normal vasculature, that was expanded in Pik3caH1047R mice. Expression of pro-inflammatory genes, including monocyte/macrophage chemokine Ccl2, in Pik3caH1047R-iLECs was associated with recruitment of VEGF-C–producing macrophages. Macrophage depletion, CCL2 blockade, or anti-inflammatory COX-2 inhibition limited Pik3caH1047R-driven lymphangiogenesis. Thus, targeting the paracrine crosstalk involving iLECs and macrophages provides a new therapeutic opportunity for lymphatic malformations. Identification of iLECs further indicates that peripheral lymphatic vessels not only respond to but also actively orchestrate inflammatory processes.
Gate-controlled hysteresis curves and dual-channel conductivity in an undoped Si/SiGe 2DEG structure
Authors: Zhang Di , Yuan Guodong , Liu Yumeng , Li Ze , Song Luhang , Lu Jun , Zhang Jieyin , Zhang Jianjun , Luo Junwei
Published: January 2023

Exploring the cryogenic transport properties of two-dimensional electron gas in semiconductor heterostructures is always a focus of fundamental research on Si-based gate-controlled quantum devices. In this work, based on the electrical and magnetic transport characteristics of Si/SiGe heterostructure Hall bar-shaped field effect transistors (FETs) at 10 K and 1.6 K, we study the effects of electron tunneling, which occurs in the heterostructure and populates the oxide/semiconductor interface, on its transport properties. The initial position of dual-channel conduction is determined by the gate-controlled electrical hysteresis curves. Furthermore, we discover that there exist different tunneling mechanisms of electrons in a Si quantum well under the action of gate voltage, and the electron tunneling can well explain the two drain current plateaus appearing in direct-current transfer characteristics. Combining the power-law exponent of electron mobility versus density curve and the gate-related Dingle ratio, we clarify the dominant scattering mechanism, and the result can be supported by different tunneling mechanisms. Our work demonstrates the gate-dependent electronic transport performance in undoped Si/SiGe heterostructure FETs, which has an implication for the development of Si/SiGe heterostructure gate-defined quantum dot quantum computation.
Prediction of π-electrons mediated high-temperature superconductivity in monolayer LiC12
Authors: Liu Ran , Lu Jiajun , Chen Hongxin , Zhao Xiuwen , Hu Guichao , Yuan Xiaobo , Ren Junfeng
Published: January 2023

Prediction and synthesis of two-dimensional high transition temperature (T
C) superconductors is an area of extensive research. Based on calculations of the electronic structures and lattice dynamics, we predict that graphene-like layered monolayer LiC12 is a π-electrons mediated Bardeen–Cooper–Schrieffer-type superconductor. Monolayer LiC12 is theoretically stable and expected to be synthesized experimentally. From the band structures and the phonon dispersion spectrum, it is found that the saddle point of π-bonding bands induces large density of states at the Fermi energy level. There is strongly coupled between the vibration mode in the in-plane direction of the lithium atoms and the π-electrons of carbon atoms, which induces the high-T
C superconductivity in LiC12. The T
C can reach to 41 K under an applied 10% biaxial tensile strain based on the anisotropic Eliashberg equation. Our results show that monolayer LiC12 is a good candidate as π-electrons mediated electron-phonon coupling high-T
C superconductor.
Uniaxial compressions induced complementarity and anisotropic behaviors in CuVP2S6
Authors: Wu Yulong , Li Yonghui , Liu Changlong
Published: January 2023

Uniaxial compressions in layered materials can change their electronic structures and properties. In this work, a bimetallic compound CuVP2S6 is simulated by using Density Functional Theory (DFT) in the presence of uniaxial compressions. Our results clearly show vertical compressions could lead to anisotropic behaviors, which include the compression effect caused by interlayer compression and the anisotropy of intralayer stretching. The vertical compressions change the V–S bonds and the P–S bonds respectively in AA and AB structures. The complementarity between intralayer stretching and interlayer compression could also result in adjustable bandgaps and degeneracy breakdown of V atoms. Results from the electron localization function analysis demonstrate that the free electrons of AA and AB structures tend to delocalize, and ionic features in V–S bonds could be weakened with increasing vertical compressions. Moreover, the two internal binding energies of AA and AB structures and the charge density difference analysis show that the anisotropy in the intralayer stretch and the charge transfer between metal atoms and S atoms increases gradually.
High in vitro activity of gold and silver nanoparticles from Solanum mammosum L. against SARS-CoV-2 surrogate Phi6 and viral model PhiX174
Authors: Pilaquinga Fernanda , Bosch Rafael , Morey Jeroni , Bastidas-Caldes Carlos , Torres Marbel , Toscano Fernanda , Debut Alexis , Pazmiño-Viteri Katherine , Nieves Piña María de las
Published: January 2023

The search for new strategies to curb the spread of the SARS-CoV-2 coronavirus, which causes COVID-19, has become a global priority. Various nanomaterials have been proposed as ideal candidates to inactivate the virus; however, because of the high level of biosecurity required for their use, alternative models should be determined. This study aimed to compare the effects of two types of nanomaterials gold (AuNPs) and silver nanoparticles (AgNPs), recognized for their antiviral activity and affinity with the coronavirus spike protein using PhiX174 and enveloped Phi6 bacteriophages as models. To reduce the toxicity of nanoparticles, a species known for its intermediate antiviral activity, Solanum mammosum L. (Sm), was used. NPs prepared with sodium borohydride (NaBH4) functioned as the control. Antiviral activity against PhiX174 and Phi6 was analyzed using its seed, fruit, leaves, and essential oil; the leaves were the most effective on Phi6. Using the aqueous extract of the leaves, AuNPs-Sm of 5.34 ± 2.25 nm and AgNPs-Sm of 15.92 ± 8.03 nm, measured by transmission electron microscopy, were obtained. When comparing NPs with precursors, both gold(III) acetate and silver nitrate were more toxic than their respective NPs (99.99% at 1 mg ml−1). The AuNPs-Sm were less toxic, reaching 99.30% viral inactivation at 1 mg ml−1, unlike the AgNPs-Sm, which reached 99.94% at 0.01 mg ml−1. In addition, cell toxicity was tested in human adenocarcinoma alveolar basal epithelial cells (A549) and human foreskin fibroblasts. Gallic acid was the main component identified in the leaf extract using high performance liquid chromatography with diode array detection (HPLC-DAD). The FT-IR spectra showed the presence of a large proportion of polyphenolic compounds, and the antioxidant analysis confirmed the antiradical activity. The control NPs showed less antiviral activity than the AuNPs-Sm and AgNPs-Sm, which was statistically significant; this demonstrates that both the S. mammosum extract and its corresponding NPs have a greater antiviral effect on the surrogate Phi bacteriophage, which is an appropriate model for studying SARS-CoV-2.
On the efficient global dynamics of Newton’s method for complex polynomials
Authors: Schleicher Dierk
Published: January 2023

We investigate Newton’s method as a root finder for complex polynomials of arbitrary degrees. While polynomial root finding continues to be one of the fundamental tasks of computing, with essential use in all areas of theoretical mathematics, numerics, computer graphics and physics, known methods may have excellent theoretical complexity but cannot be used in practice, or are practically efficient but lack a successful theory behind them. We provide precise and strong upper bounds for the theoretical complexity of Newton’s method and show that it is near-optimal with respect to the known set of starting points that find all roots. This theoretical result is complemented by a recent implementation of Newton’s method that finds all roots of various polynomials of degree more than a billion, significantly faster than our upper bounds on the complexity indicate, and often much faster than established fast root finders. Newton’s method thus stands out as a method that has strong merits both from the theoretical and from the practical point of view. Our study is based on the known explicit set of universal starting points, for each degreed, that are guaranteed to find all roots of polynomials of degreed(appropriately normalized). We show that this set containsdpoints that converge very quickly to thedroots: the expected total number of Newton iterations required to find alldroots with precisionɛisO(d3 log3d+d log | log ε|), which can be further improved toO(d2 log4d+d log | log ε|). The key argument shows that many root finding orbits are ‘R-central’ in the sense that they stay forever in a disk of radiusR, and each iteration ‘uses up’ an explicit amountAn,k(ℓ)of area within this disk.
Thick hyperbolic repelling invariant Cantor sets and wild attractors
Authors: Ding Yiming , Xiao Jianrong
Published: January 2023

Let D be the set of

β
∈
(
1
,
2
]

such that f

β
is a symmetric tent map with finite critical orbit. For

β
∈
D

, by operating Denjoy-like surgery on f

β
, we constructed a C
1 unimodal map

g
˜

β

admitting a thick hyperbolic repelling invariant Cantor set which contains a wild attractor. The smoothness of

g
˜

β

is ensured by the effective estimation of the preimages of the critical point as well as the prescribed lengths of the inserted intervals. D is dense in

(
1
,
2
]

, and

g
˜

β

can not be

C

1
+
α

because the hyperbolic repelling invariant Cantor set of

C

1
+
α

map has Lebesgue measure equal to zero.
A global-local damage localization and quantification approach in composite structures using ultrasonic guided waves and active infrared thermography
Authors: Balasubramaniam Kaleeswaran , Sikdar Shirsendu , Ziaja Dominika , Jurek Michał , Soman Rohan , Malinowski Paweł
Published: January 2023

The paper emphasizes an effective quantification of hidden damage in composite structures using ultrasonic guided wave (GW) propagation-based structural health monitoring (SHM) and an artificial neural network (ANN) based active infrared thermography (IRT) analysis. In recent years, there has been increased interest in using a global-local approach for damage localization purposes. The global approach is mainly used in identifying the damage, while the local approach is quantifying. This paper presents a proof-of-study to use such a global-local approach in damage localization and quantification. The main novelties in this paper are the implementation of an improved SHM GW algorithm to localize the damages, a new pixel-based confusion matrix to quantify the size of the damage threshold, and a newly developed IRT-ANN algorithm to validate the damage quantification. From the SHM methodology, it is realized that only three sensors are sufficient to localize the damage, and an ANN- IRT imaging algorithm with only five hidden neurons in quantifying the damage. The robust SHM methods effectively identified, localized, and quantified the different damage dimensions against the non-destructive testing-IRT method in different composite structures.
Multiple poles resonances coupling with high sensitivity sensing for multiple bulging black phosphorus-based metasurface
Authors: Yang Nengxun , Wang Yixuan , Li Lingqiao , Ren Yang , He Zhihui , Cui Wei , Yang Zhimin , Lu Shaojun , Wu Xiongxiong , Bai Lang
Published: January 2023

Herein, a multiple bulging black phosphorus (BP)-based metasurface is proposed for studying its reflection responses and sensing performances through the finite-difference time-domain simulation method. It is shown that, the reflection dips are caused by the coupling between dipole resonance modes and poly-poles resonance modes. Moreover, the dipoles resonance modes and poly-poles resonance modes can mutually enhance and inhibit each other, and tunable reflection spectra can be realized by symmetrically and asymmetrically adjusting the bulging of the proposed BP-based metasurface. In addition, the reflection spectra as a function of the polarization of incident light are discussed. We can find that a dipole resonance mode on the vertical side at the direction of ZZ for BP is gradually fully excited, resulting in an additional obvious reflection dip as the polarization angle θ increases from 0° to 90°. Especially, the sensing performance with the maximum of sensitivity S = 1.5 μm/RIU can be realized in the proposed BP-based metasurface. The results may provide a way to design micro-nano plasmonic devices.
Manipulating topological intravalley and intervalley scatterings of inner edge states in hybrid nanoribbons
Authors: Lü Xiao-Long , Xie Hang , Yang Jia-En , Li Ru-Xue , Du Long , Chen Hua-Jin , Zhang Hui-sheng
Published: January 2023

We investigate the formation of inner edge states and their transport properties in hybrid nanoribbons. Some new inner edge states, such as spin-polarized, spin-valley-polarized and valley-polarized antichiral inner edge states, are obtained, different from the current existence of valley- and spin-valley-momentum locked inner edge states. We also obtain general formula of local bond current with the wave-function matching technique and use it to discover three interesting transport phenomena of the intravalley and intervalley scatterings that depend on the propagating direction, propagating path, spin mode and wave-vector mismatches between inner edge states. In particular, these transport phenomena are further used to design topological spin, spin–valley and valley filters and be representative for graphene, silicene, germanene and stanene, supporting a potential application of inner edge states, which are robust against random vacancies.
Visually capture quantum nonlocalities through quantum steering ellipsoid
Authors: Xing Ling-Ling , Yang Huan , Li Ze-Bin , Xu Zong , Kong Min , Zhang Gang
Published: January 2023

Quantum steering ellipsoid (QSE) can faithfully characterize arbitrary bipartite state, and provide a new method to visually investigate and capture various quantum nonlocalities. Note that the dissipation of quantum nonlocalities can be accelerated by the coupling between the system and the decoherence channel, which induces great challenges in detecting quantum nonlocalities. Herein, considering the scenario in which the subsystem of a two-qubit system is coupled with a decoherence channel, the quantum discord (QD) and concurrence are visually characterized and detected by employing the QSE. The results reveal that the QSE y and z semiaxes are responsible for the traits of the QD and concurrence under the bit flip channel. The x and y semiaxes dominate and visualize the QD and concurrence under the phase damping channel. Of particular note is that one can realize the detections of the QD and concurrence via the shape of the QSE. To be clearer, the disappearance of the QD can be ascertained according to a needle-shaped QSE or a vanishing QSE in the Bloch sphere. In contrast, one can witness the concurrence if the total semiaxis length is greater than one. Beyond this, our results visually reveal that quantum entanglement is a stronger quantum nonlocality than the QD from the perspective of geometry, and thus deepens the understanding of the quantum nonlocality.
Fusion product diagnostics based on commercially available chemical vapor deposition diamond detector in large helical device
Authors: Ogawa K. , Isobe M. , Weiss C. , Griesmayer E. , Sangaroon S. , Takada E. , Masuzaki S. , Ohtani H. , Liao L.Y. , Tamaki S. , Murata I. , Osakabe M.
Published: January 2023

Fusion product diagnostics based on four commercially
available single-crystal chemical vapor deposition (s-CVD) diamond
detectors are installed in the Large Helical Device (LHD) in order
to understand energetic ion confinement. Characteristics of s-CVD
diamonds were surveyed using alpha and D-T neutron sources. It is
found that the energy resolutions of s-CVD diamonds for ∼ 5 MeV
alpha particles and 14 MeV neutrons are 1%–3% and ∼ 1.7%,
respectively. Moreover, the response of four s-CVD diamond detectors
to alpha particles and D-T neutrons is almost identical. The
installation positions of the diamond detectors in the vacuum vessel
are searched for, based on the loss points of charged fusion
products reckoned by Lorentz orbit calculations. Energy- and
time-resolved measurement of fusion product flux will progress in
further understanding of energetic ion confinement in LHD.
Human influence on historical heaviest precipitation events in the Yangtze River Valley
Authors: Wang Ziyue , Sun Ying , Zhang Xuebin , Li Tim , Li Chao , Min Seung-Ki , Hu Ting
Published: January 2023

With the recurrence of high-impact extreme events and the growing public demands to understand the causes of the events, event attribution has emerged as a frontier of climate change research. Typically, an event attribution study focuses on one individual extreme event that has just occurred. Studies rarely examine human influence on multiple extreme events in different times of the past. Here we conduct a comprehensive attribution analysis on the four heaviest precipitation events in the Yangtze River Valley during the past 100 years. We start by defining extreme precipitation events as the heaviest precipitation over a fixed size area that is of direct relevance to flood preparedness and management. When examining the events over the historical time, we allow the precise location of the area to change in different years. By definition, four extremely strong events are identified, and they happened in the summer of 1931, 1954, 1998 and 2020. We find that the impacts of greenhouse gases (GHGs) and anthropogenic aerosols (AAs) on these events show clear difference in different time period. The impacts were negligible in the early period and became more and more discernible since the late 20th century. The GHGs have gradually increased the occurrence probability of extreme precipitaiton while the AAs have decreased the occurrence of extrem precipitation. These competing effects from the GHGs and AAs have led to a slight and then gradually increasing human influence on extreme precipitation over time. GHGs have exerted a larger influence on short-duration precipitation events while AAs have had a larger influence on monthly mean precipitation. The more extreme the precipitation event, the clearer the anthropogenic influence.
A short review on Substantial role of Geopolymer in the sustainable construction industry
Authors: Devarajan Parthiban , Sivalinga vijayan Dhanasingh , Sanjay Kumar R , Arun Frait King J
Published: January 2023

Civil engineering has made significant strides in the discovery and application of novel materials during the past several decades. This list of notable substances contains a novel substance referred to as “Geopolymer,” which has been defined as a new bonding material derived from inorganic chemistry via polymerization of alumina-based silicate oxides with sodium, calcium, or potassium-based hydroxide compounds. The mixture of these chemical compounds, when applied, initiates an alkaline activation reaction that leads to the development of a nebulous structure. Unlike most organic or inorganic polymers, geopolymer is exemplified at temperatures below 1000°C. Because geopolymer is more eco-friendly than currently available construction adhesives, its use in building activities is on the rise. This review includes an examination of the history of geopolymer, the essential silicate material required to prepare geopolymer, the presence and reactions of the chemical compounds used to create alkaline activator solutions at different molar ratios, the curing conditions, the engineering characteristics of geopolymer activated specimens, and their resistance to chemicals. This review concludes that geopolymer technology is the best material for several applications in civil engineering in the twenty-first century.
Comparative study of Conventional and other Filter Medium
Authors: Krishnamurthy N R , Nagasai T , Anil Kumar M , Siva Kumar P , Ravi Kumar N
Published: January 2023

In this new era of urbanisation and industrialisation involving new constructions and other conveniences resulting in depletion of huge natural resources. In order to resolve this recurring issue, people have begun their research to find some vital alternative materials to save these natural resources from depletion. A natural resource such as river sand is used extensively in the filtration process of water treatment, which is essential for living. Hence there will be an urgent need to improve the performance of such treatment plants by carrying out appropriate modifications and improvements using other materials such as M- sand, glass etc. Utilization of M-sand not only eco-friendly but also resolves the issues related to, shortage of convention material. In this paper, an attempt was made in regards to M-Sand and Crushed glass, which includes the study of their medium characteristics. In addition to them, Turbidity, Flow rate, Hardness, Sieve tests were conducted and their results are compared with conventional river sand medium.
Influence of loading type and rectangular opening on the behaviour of GFRP stiffened panels
Authors: Anitha Priya Dharshani S. , Meher Prasad A. , Sundaravadivelu R.
Published: January 2023

Stiffened panels are basic parts of ship hulls and decks. Effect of buoyancy and cargo loading on the stiffened panels leads to application of axial loading and pressure loading in out-of-plane direction. Fiber reinforced polymer (FRP) stiffened panels with high corrosion resistance, high strength, high stiffness and light weight is the best alternative for conventional steel stiffened panels. Because conventional steel stiffened panels experience sever corrosion when used for marine structures. For maintenance purpose, rectangular openings are provided in ship decks. The presence of opening leads to reduction in strength, reduction in stiffness, and critical failure patterns for stiffened panels subjected to axial and pressure loading. In this study, behaviour of Glass fiber reinforced polymer (GFRP) stiffened panels with rectangular opening subjected to axial and pressure loading are studied experimentally by conducting tests. GFRP stiffened panels are fabricated in such a way that the plate and stiffeners are monolithic in construction. The effect of type of loading and the rectangular opening on the strength, stiffness and span/deflection ratio of GFRP stiffened panels are discussed. Failure pattern and maximum failure strain of GFRP stiffened panels subjected to axial and pressure loading are presented.
Performance Assessment and Engineering behaviour of Cement Concrete with partially Replaced Foundry Sand as Fine Aggregate
Authors: Sanjay Kumar R , Devarajan Parthiban , vijayan Dhanasingh sivalinga , Kumar Aravind S , Kadavan Akhil S , Rajesh Rohan
Published: January 2023

Metal foundries make heavy use of metal casting. The residual sand, also known as foundry sand, is removed from the foundry after numerous cycles of recycling and reuse have been completed successfully. This article describes the environmentally safe and technically sound uses of foundry sand in civil engineering. Using foundry sand in several engineering applications can solve the problem of foundry sand disposal and other problems. Silica sand is the primary component of foundry sand, which is subsequently coated with a thin layer of carbon, dust, and any leftover binder. Foundry sand can increase the strength and durability of concrete. Foundry sand can be used as a supplement, a partial replacement for fine aggregate, a complete replacement for fine aggregate, or as a replacement for cement in order to achieve a variety of concrete properties. In the present study, the impact of replacing fine aggregate with foundry sand on the compressive strength, split tensile strength, and elastic modulus of concrete with mix proportions of 1:1.45:2.2:1.103 was analysed. Three proportions of foundry sand were substituted for fine aggregates. The replacement percentages for fine aggregate were 10, 20, and 30 percent by weight. During varied curing times, compressive strength, split tensile strength, and elastic modulus tests were conducted on all replacement sand levels (14-days & 28-days) Test findings revealed a modest improvement in compressive strength, split tensile strength, and modulus of elasticity when fine aggregates were replaced with a certain amount of foundry sand. This indicates that foundry sand can be safely utilised in concrete for durability and strength purposes.
Lightweight Heat Resistant Concrete Panels Using Recycled Materials
Authors: Durgadevi S , Udhayakumar K , Praveen M , Krishnakumar R , Natarajan N , Jayaraman A , Vasudevan M
Published: January 2023

The demand for sustainable building materials is increasing day-by-day pertaining to the challenges in meeting the cost, reliability and climate adaptability. In addition to the structural requirements, improvements in the building technology are also trending towards eco-friendly, comfortable and economic housing solutions. The present study deals with the usage of two industrial waste materials (bagasse ash and granite powder) to prepare lightweight and heat resistant concrete panels (M25 grade). The replacement of aggregates was accomplished sequentially by varying the mix proportioning (10%, 15%, 20% and 25%) using granite powder and bagasse ash balls (~10mm dia.). In addition to the weight reduction, coconut fibres and paraffin were also applied in intermittent layers to enhance thermal insulation properties. The temperature profiles were monitored using thermocouple sensors fitted onto the panel surfaces. The physical, mechanical and thermal properties of the casted panels were studied after 28 days of curing. A comparative study was made for solid and hollow light panels in terms of strength and weight. The results indicated that significant temperature reduction is achieved between the surfaces by using the phase changing materials (3%) while the compressive strength of the hollow lightweight panel is satisfactory (23.48 N/mm2). Hence, the prepared concrete panels can be suitably employed in building construction where thermal comfort and reduced weight are in demand.
Use of marble and granite dust waste as partial replacement of fine aggregates in concrete
Authors: Mhamal Aditi A , Savoikar Dr. P. P
Published: January 2023

The growth in Infrastructural development resulted in fast decline of available natural resources. In contrast the marble and granite production has generated a very huge amount of by-products in the form of fine particles which causes large scale environmental pollution. This has led to a major concern in the environmental as well as construction industry due to the disposal of these million tons of fine particles. The purpose of this study is to experimentally investigate the compatibility of marble and granite dust by-product for replacing of fine aggregates in concrete partly. In this work, a mixture of marble and granite dust in ratio 0.5:0.5 is used as a for replacing of sand in different percentages (10%,20%,30%,40%,50%) by weight and cement is partially replaced with slag (GGBS) by a by 40%. Influence of replacement of sand with marble and granite dust on the strength behaviour on concrete was studied at curing ages 7 and 28 days and the results are compared with conventional concrete blocks. A 20% replacement of fine aggregates with marble and granite dust mixture resulted in 23.34% and 14.4% increase in compressive strength was at 7 and 28 days of curing, as compared to controlled concrete. The results of the experimental study show that, mixture of marble and granite dust can partially be used in place of fine aggregate in concrete and saves considerable amount of sand there by preserving the valuable natural resource resulting in sustainable replacement for sand.
A study on Real time strength assessment of concrete by maturity method
Authors: Mahendra Reddy N , kasagani Hanuma , Harshith chowdary U
Published: January 2023

The Nurse-Saul technique is employed to ascertain a member’s strength. Because the concrete members’ strength is being estimated in real-time concrete members. Using the Nurse-Saul maturity method, the member is precisely strengthened at a specific temperature, and after achieving its initial strength, the formwork is removed. The benefits of using the maturity process are covered, along with alternative methods for calibrating indicator of maturity. the capability of a structure, which can be determined in a number of destructive (or) non-destructive ways, is a crucial component for a suitable operational condition in terms of conditional assessment. The maturity approach is one such non-destructive technique that delivers excellent outcomes. Usually, after a mixture has fully cured, test cylinders are cast to measure its strength. The results are then analyzed in a lab (3, 7, 28 days). This technique takes more time to ascertain the strength of a certain mixture. Using the maturity approach, we calculated the member’s temperature and used that information to resolve the problem. Because this maturity process has already been employed by other researchers for standard concrete mix designs, this work will concentrate on unusual concretes. Due to the rarity of experiments on unique concrete, this process was tested using concrete blocks. As a result, this maturity approach is is a method for evaluating the strength of any concrete elements by measuring the temperature of the structure.
A study on the Water Proofing Behaviour of Fly Ash, M-sand and Dust based concrete with varying percentages of different Crystalline Admixtures
Authors: Kumar Kakaraparthi Phani , Rao Mandava Kanta
Published: January 2023

For many years, concrete has been the most commonly used building material. When we focus on sustainable materials, long-term serviceability becomes an issue. There are methods for lowering risks and increasing service life. Crystalline admixtures, also known as permeability-dropping, are marketable products used in little concentrations in cement incorporated materials to enhance concrete durability and promote autogenous crack healing. This paper presents various investigations into the mechanical and long-term durability characteristics of concrete made with Fly ash, M-sand, Dust. In this study, fly ash is used as a 30% substitute for cement, M-sand and Dust is used as a 100% substitute for river sand and two types of crystalline admixtures with different proportions of 0%, 0.5%, 1.0%, and 1.5% were added to the mix. Cubes and Cylinders were casted by mixing M-Crete and Master Pel 760 crystalline admixtures for two grades, M25 & M35 and left for curing period of 28 days. Test methods include compressive strength, split-tensile strength, RCPT, % of water absorption and % of Voids. The test results showed that both crystalline admixtures with Fly ash at 0.5% produced better results and significant rise in compressive strength and tensile strength. Similarly, a decrease in percentages of RCPT, water absorption, voids was observed in both M25 and M35 grades. Finally, Master Pel 760 has shown better performance than M-Crete crystalline admixture. So, the above two crystalline admixtures have the potential to increase the durability and decrease the permeability of concrete.
Flexural Performance of Sustainable Fly Ash Based Concrete Beams
Authors: Saketh Raj B , Kanta Rao M
Published: January 2023

The demand for concrete is high due to its solid strength and flexibility. To produce more concrete requirement of cement is very large. The production of concrete releases CO2 into the atmosphere. This can lead to global warming. By including other substances that have a cementations tendency, cement consumption can be decreased. To lower the cement consumption in concrete, a variety of pozzolanic ingredients are being used. It is being investigated whether fly ash can replace cement. Flexural tests were performed on reinforced concrete beams with fly ash contents ranging from 0% to 60% and binder contents of 400 and 450 kg/m3 with a water binder ratio of 0.4. The beam size is 100X200mm with a length of 1.2 m. It was observed that all the beams failed under compression in both mixes. In both, the mixer’s depth of crack is reduced when compared with the fly ash incorporated beams with no-fly ash concrete beams. The quick spread of the fracture is slowed down by the addition of fly ash to concrete. The filler effect, which aids in pore refinement and prevents the creation of cracks as well as the enlargement of propagated cracks, is initiated in the concrete as the fly ash content rises. According to the experimental findings, the load capacity of RC beams containing 30% fly ash is the greatest of all the beams. The outcomes for exhibit the same behaviour. Compression resistance. Finally, it was shown that, versus ordinary concrete RC beams, the inclusion of fly ash boosted the beam’s capacity to carry loads by up to 40% fly ash replacement. Whenever the fly ash content is increased by up to 40% replacement, the RC beam’s final deflection increases.
Experimental Investigation on Carbonation of Concrete Using SEM –EDX(Scanning Electron Microscopy (SEM) with Energy Dispersive X-Ray Analysis (EDX) & Environmental Scanning Electron Microscope(ESEM) Analysis
Authors: Akhila Jupaka , Rao Nimmagadda Venkat
Published: January 2023

The alkalinity of the concrete protects the reinforcing bars against corrosion, but the carbonation phenomenon accelerates the loss of their motionless coating, favouring corrosion start. Concrete that has been carbonated has a lower pH values which can lead to reinforcement corrosion. Reinforcement corrosion is the most common cause of reinforced concrete degradation Variables such as dimensional carbon dioxide in gress, duration of carbon dioxide ingress, grade of concrete, and CO2 volumetric concentration are all considered in this research. The specimens wereplaced in a chamber with a carbon dioxide gas supply after 28 days of water curing. The specimens were exposed to carbon dioxide for 145 hours and 290 hours, respectively, in a carbon dioxide chamber. The specimens were then cut at 1cm, 2cm, and 3cm intervals from the concrete surface. The powder from crushed concrete specimens was pulverised and sieved through a 90m sieve, with the powder collected as sample powder. In the present study an experimental investigation was conducted on concrete for determining the flexural strength and SEM- EDX & ESEM analysis. The specimens were tested after 28 days of curing as per determined time. The compressive strength, tensile strength and flexural strength of concrete is determined for the 7days,14 days and 28days curing.
Seismic Analysis of Soft Storey Building in Earthquake Zones
Authors: Suresh Kannan S
Published: January 2023

In this paper (G+8) building is modeled like a bare frame, a bare frame with the shear wall, and a bare frame with X bracing by changing the soft storey to different floors. The static analysis effect is determined for all three models with zone IV and zone V using Staad pro-V8i software. The main objective of the research was to assess the impact of a soft storey in various earthquake zones and by varying places of the soft storey from first to the top floor and for frames with different column shapes by seismic analyses in staad pro. The results of variable building models are obtained from the research regarding various parameters such as displacement, storey drift, and base shear. More significantly, comparing different structural systems revealed a reduction in lateral displacement and story drift. The shear wall reduced the Storey Displacement by 98.838% and storey drift by 99.86%. The Steel bracing reduced the Storey Displacement by 97.846 % and storey drift by 92.6%. Finally, it has been found that the Shear wall reduces lateral displacement and storey drift, thus significantly contributing to greater structural stiffness. The analysis results recommended that the shear wall use reinforced concrete frames for the seismic hazard zones and the Steel bracing recommended for the low seismic zones.
Mechanical And Durability Behaviour Of GGBS, M-sand Based Concrete With Varying Percentages Of Two Crystalline Admixtures – An Experimental Study
Authors: Sameera Vajrala Kavya , Keshav Lakshmi
Published: January 2023

This paper presents various investigations into the mechanical and long-term longevity parameters of concrete made with ground granulated blast slag (GGBS). In this experimental study, GGBS is used as a 30% substitute for cement, and two types of crystalline admixtures (CA’s) with different proportions of 0%, 0.5%, 0.75%, and 1% were added to the mix. Cubes and Cylinders were casted by mixing Mcrete and Master Pel 760 crystalline admixtures for two grades, M25 & M35 and left for curing period of 28 days. Test methods includecompressive strength, split tensile strength, Rapid Chloride Permeability test (RCPT), Sorptivity, Percentage of water absorption, Percentage of Voids and carbonation. The test results showed that both CA’s with GGBS at 0.75% produced better results and also significantly increased compressive strength by 12.08% for M25 grade and 16.04% for M35 grade, and tensile strength by 19% for M25 grade and 30.59% for M35 grade. Similarly, a decrease in percentages of 14.7 & 16.9 in RCPT, 8.52 & 11.19 in water absorption, and 11.34 & 10.01 in voids was observed in both M25 and M35 grades. Finally, Master Pel 760 has shown better performance than Mcrete Crystalline admixture. So, the above two CA’s has the potential to increase the durability and decrease the permeability of concrete buildings, particularly those exposed to corrosive conditions.