bluuebunny/crossref_metadata_2025_split huggingface dataset:
Holocene fluctuations in vegetation and human population demonstrate social resilience in the prehistory of the Central Plains of China
Authors: Ren Xiaolin , Xu Junjie , Wang Hui , Storozum Michael , Lu Peng , Mo Duowen , Li Tuoyu , Xiong Jianguo , Kidder Tristram R 
Published: January 2021

Abstract
Archaeologists and palaeoclimatologists have focused on the impact of climate on the prehistoric civilizations around the world; however, social resilience in the face of the climate change remains unclear, especially during the Neolithic and Bronze Age in the Central Plains of China (CPC). In this paper, we present palynological results from the Dahecun Core, Henan Province, China. Our pollen data indicate a warm and wet climate condition from 9200 to 4000 cal BP, which then switches to a cool and dry climatic condition during the Neolithic-Bronze Age transition (∼4000–3600 cal BP). We analyze 14C dates from archaeological sites to demonstrate four episodes of population increase and present vegetation dynamics, determined from available pollen data, to provide evidence for the synchronous shifts in vegetation and human population during the Neolithic. Our results indicate that the aridification in the early Bronze Age did not cause population collapse, highlighting the importance of social resilience to climate change. The pollen, radiocarbon dates and archaeobotanical records from the CPC provides new evidence that supports the claim that the development of agriculture and complex societies, under the stress of a dry climate, set the stage for the dramatic increase of human population around 3800–3400 cal BP.
Finite-velocity diffusion in the presence of a force
Authors: Cáceres Manuel O 
Published: January 2021

Abstract
We have studied a Cattaneo–Fick diffusion process in the presence of a deterministic force. Specifically, analytic results for the stationary probability distribution are solved for stable and unstable potentials. It is shown that the finite support as well as the shape of the stationary density are controlled by the telegrapher’s parameters (relaxation time T and velocity of propagation θ). We have found the occurrence of a multimodality transition depending on the critical exponent of the potential and parameters T, θ. This research is motivated by the study of exact results for generic Smoluchoswki-like processes with finite-velocity diffusion.
Crack width evaluation of Reinforced Concrete beam in flexure
Authors: Dash Bimalendu , Markandeya Raju P , Mishra Kapileswar 
Published: January 2021

Abstract
Crack width evaluation of flexural RC member is evaluated analytically by two significant formulas given by researchers and four standard code i.e. IS 456-2000, BSEN 1992-1-1-2004, ECP 203-2007, ACI 318-95 and compared. Parameters such as clear cover, the effect of diameter, variation of depth, number of bars with the same cross-section and increasing external moment are considered for computing the crack width. From the study of results of this study, it can be concluded that clear covers estimated based on IS 456 2000 are highest and those estimated based on EGYPTIAN CODE; 203-2007 are lowest as compared to other codes and mathematical models considered in this study. It can also be concluded that crack width increases with increase in clear cover or external moment while it decreases with increase in reinforcement diameter, depth of the beam or number of bars.
Reliability analysis of doubly Reinforced Concrete Beams retrofitted by plate bonding
Authors: Markandeya Raju P , Lal Mohiddin Sk. 
Published: January 2021

Abstract
This paper concerns the safety of the simply supported reinforced concrete beams subjected to only bending loads: so that the reliability index and probability of failure are to be calculated. Reliability index was carried out by using Hasofer-Lind method for the doubly reinforced beam with and without retrofitted beams having externally bonded plates (porous and solid) with variable thickness for the limit state in bending. Reliability index can be calculated by using MS-EXCEL. The reliability index for control beam is 0.4022 and the FR-A4 beam is 3.9791. So, the reliability index is high for retrofitted beam only. The Probability of failure (3.5E-05) for FR-C4 beam is very low under the combination of porous plate and 3mm plate thickness.
Mathematical Model for Natural Frequency of Prestressed Concrete beam using STAAD.Pro.
Authors: Markandeya Raju P , Pavan Kumar M , Adiseshu S , Sai Sravan Kumar V V 
Published: January 2021

Abstract
The problem of assessing the variation in natural frequency of a prestressed and un-prestressed beam has been of considerable interest to Structural Engineers. The objective of the present work is to find the effect of pre-stressing on Natural frequency of a Concrete beam and thereby establishing a relationship between the natural frequency of 1st mode of vibration and other modes. Conventional methods were used to calculate the natural frequency of 1 to 5 modes of vibration for un-prestressed beams while STAAD.Pro was used for assessing the same for prestressed beams. A 20 m span beam with different live loads and cross-sections were considered for the study. From the results, it was observed that as the cross-section of the beam increases, the natural frequency decreases. Comparing the natural frequency of 1st mode of vibration for beams with and without prestressing, it can be observed that within the scope of this work, the natural frequency of the un-prestressed beam with live load 15 kN/m is more than that for the prestressed beam. For the other two load-carrying capacities, it is vice-versa. It was also observed that the % difference of Natural frequency of a particular mode of vibration w.r.t mode 1 natural frequency is almost constant. In other words, the effect of live load and cross-section is negligible on the % difference of Mode i to Mode 1 natural frequency. Based on this characteristic, a mathematical model has been developed.
A comparative study of slope stability analysis of Manganese slag stabilized soil to an ordinary soil
Authors: Parimi Sumanjali , Satyanarayana P V V 
Published: January 2021

Abstract
Slopes are required in the construction of Highways, Railways, Earthen dams, canal banks, levees and at many other locations. The construction of embankment over the ground is not possible in a vertical way. The Soil can be piled up with slope only. The cost of earthwork is minimum if the slopes are steepest but the Steeper slopes are not safe as per stability conditions because it may fail in shear. The only force acting on the piled earth is gravity force. This gravitational force produces shear in the soil and causes slippage. The failure lead to loss of property and life. There is a lesser chance of slippage of soil if we provide more bottom width compared to its top width. But it requires more area and more earth to fill. So, it is uneconomical.
In the present study, the soil was collected from the highway extension project, from the geotechnical investigation it was identified that the soil shear strength was quite low. To improve shear characteristics and to decrease the dry density of soil, it is to be stabilized with a lightweight material, possessing good frictional characteristics. A waste by-product was identified from the industry of nearest village called Manganese (Mn) slag. The soil was stabilized with various percentages of Mn slag, from the geotechnical characterization, an optimum % of slag is selected as 10 %. An embankment slope is assumed for further slope stability analysis. The analysis is carried out on two slopes, one is made with ordinary soil and the other is soil stabilized with optimum Mn slag %. Both stabilized soil embankment and ordinary soil embankment are analysed by using the Method of slices and the final results were compared.
Effect of bamboo fibres and lime on engineering properties of expansive soil
Authors: Prasad D S V , Sivannarayana Ch , Sunitha P 
Published: January 2021

Abstract
Shear strength, differential settlements and lofty compressibility, extensive soil usually create a problem for civil engineers and geotechnical engineers. Stabilization is one of the oldest ways to augment the soil quality of problematic soil. In current time, it has been experienced to the totalling of fibres improves the ductility performance of the soil close by tumbling the maturity of fractures throughout the contraction. This paper illustrates the outcome of lime plus bamboo fibres on strength performance black cotton soil blending with different percentages by conducting California Bearing Ratio, Modified Proctor Compaction as well as Unconfined Compressive Strength at various curative periods. The test result indicates that strength characteristics of the most viable combination of black cotton soil-lime sample combined with bamboo fibres are considerably better than un-treated black cotton soil and also the strength of soil increased due to increase in the curing period.
Effect of various mineral and chemical admixtures on the improvement of subgrade CBR
Authors: Ponnada Sudheer , Rajeswararao K , Markandeya Raju P 
Published: January 2021

Abstract
Increase in the rate of traffic volume and heavy vehicle loads gave a revolution in highway construction technology, this increase is due to continuous growth in economic activities. Therefore, it is necessary to construct highly durable and serviceable road structures on any type of soil. In continuation, a good subgrade can influence the thickness of road structure, increases the strength pavement, and reduce the cost of road structure construction. California bearing ratio (CBR) is a generally utilized in-direct technique to evaluate the strength’ of subgrade and it directly gives the pavement thickness in pavement analysis and design work. So, if increasing in the CBR value results thicknesses of the pavement will decrease and it, in turn, reduces the construction cost of the pavement structure. In the present investigation, the collected soil samples are Black Cotton soils from Dharmapuri, Vizianagaram, AP. Same soil stabilized with various replace percentages of Fly ash and Ground Granulated Blast Furnace Slag (GGBS) (i.e. up to 10%) and NaOH (i.e. 5%). The Atterberg limits, Free swell Index, and CBR tests were completed on original and stabilized soils. Finally, authors observed that the considered BC soil stabilized with mineral admixture (Fly ash and GGBS) and chemical admixture (NaOH) results in more than 400% increase in CBR with 35% decrease in pavement thickness, and 23% decrease in pavement construction cost.
Sustainable materials in the production of pavement base and subbase courses
Authors: Ram Kumar B A V , Ramakrishna G 
Published: January 2021

Abstract
The use of sustainable materials in construction is the need of the hour amidst the depletion of natural resources at a rapid rate. The significance of green roads is increasing day by day and green approach for road construction can be only achieved by the use of sustainable construction materials. In the present study, an effort has been made to make base and subbase courses sustainable using Reclaimed Asphalt Pavement (RAP) and Ground Granulated Blast Furnace Slag (GGBS) along with a very less quantity of cement. RAP used in the present study was obtained from the in situ milling of NH-16 at Srikakulam. To meet the gradation requirements as per IRC Ground Granulated Blast Furnace Slag (GGBS) was used along with RAP. Upon initial trial tests, it was concluded that unbound specimens made with RAP and GGBS have failed to meet the minimum unconfined compressive strength(UCS) requirements as per IRC: SP-89:2010 due to which cement by weight of 2% of total mix was added to meet the UCS requirement of 4.5 MPa at seven days. The optimum proportion of RAP that can be used to replace virgin aggregate (VA) was found to be 30% based on UCS test results. The durability studies of GGBS stabilized RAP/VA mixes were found to be satisfactory. The retained strength of the samples after durability studies is 91.43% which is greater than 80% as specified by IRC: SP-89:2010.
Compressive strength of concrete with partial replacement of Fine Aggregate with crushed Electronic waste plastic
Authors: Veerabhadram Kandalam , Satya Bhavya B L , Mani Bhaskar S 
Published: January 2021

Abstract
Electronic waste (E-waste) of about 53.6 MT is generated globally with 7.3 kg per capita, wherein India generates about 1.72 MT. Out of the total generated e-waste, only 17.4% is recycled properly. The e-waste constitutes both organic and inorganic compounds while handling. Plastic waste is one of the inorganic compounds of e-waste, which has majorly become a massive problem owing to its non-degradable property. Moreover, a very less percentage of this is being reused/recycled every year. This also has many negative impacts on the environment so there is a necessity to study its uses alternately. Therefore, it is preliminarily desired to attempt in replacing the fine aggregate to certain percentage viz 0%, 10%, 15%, 20% by using available plastic components of e-waste available from circuit boards, body cabinets of a computer after crushing. In this paper, an attempt has been made to observe the effects of partially replacing fine aggregate with e-waste (plastic). The impact of alternative material to fine aggregate in material compositions is determined by testing the physical (Density) & strength (Compressive and Flexural) properties of concrete. Testing for these impacts helps in understanding the extent up to which these wastes can be used in concrete. Thereby, the usage of natural materials in construction practices can be reduced. Finally, it is inferred that the usage of e-waste plastic particles as a part of the reuse mechanism helps in improving sustainability due to less usage of sand.
Verification of irregularities in a reinforced concrete tall structure
Authors: Raju Penumatcha Krishnam , Ravindra Vipparthy 
Published: January 2021

Abstract
Building plans with simple, regular and compact arrangements are preferred to perform well during the occurrence of earthquakes. In practice, planning a regular layout may not be possible in all occasions due to irregular shape of building sites in the plan as well as in elevation due to uneven ground conditions. It is a challenge both for the architect and structural designer to plan and design such buildings. Further, the planning is to be made in compliance with the rules and regulations of the local approving authorities, which sometimes may lead to irregular shapes both in plan and elevation. Most of the times, the owner’s and / or builder’s requirement is to be fulfilled such that the project is viable to them. This is a challenge for the practising professionals designing the structures that are built in earthquake zones of III, IV and V. The earthquake resistant design code i.e., IS 1893 (Part 1) was revised in the year 2016 and adopting the provisions of building irregularities with more restrictions on their allowable limits. This paper addresses the identification or verification of the existence of building irregularities in a 17 storey multipurpose tall structure with two parking, two commercial and 13 residential floors. From the results, it is opined that there is a need for a review of the procedure and some of the limits set on irregular building configurations particularly Stiffness, Excessive openings, Out-of-plane offsets, Strength, In-plane discontinuity and Irregular modes of oscillation.
Influence of rare-earth element doping on interface and mechanical properties of WC particles reinforced steel matrix composites
Authors: Li Zulai , Zhao Wei , Zhang Donglan , Shan Quan , Zhang Fei , Wang Xingyu 
Published: January 2021

Abstract
In this paper, WC particles reinforced steel matrix composites (WCP/SMC) doped with rare-earth elements Y, Ce, La, and Nd, are manufactured via powder metallurgy sintering. The interface and mechanical properties of WCP/SMC are theoretically and experimentally investigated. The microstructures are observed through SEM, EDS and XRD. The properties are determined by compression and micro-hardness tests. The effects of rare-earth element doping on interface and mechanical properties of composites are investigated. The results indicate that composites mainly consist of α-Fe, W2C, WC, and Fe3W3C. In addition, the doping can accelerate the inter-atomic diffusion of the atoms in the interfacial reaction zone, promote the formation of Fe3W3C phase, and widen the interfacial reaction zone. Doping of rare-earth elements can reduce the hardness difference between the interfacial reaction zone and the composite matrix from 10.15 to 5.71 GPa and increases the compressive strength from 296.7 to 659.2 MPa. First-principles calculations indicate that doping of rare earth can reduce the interfacial, formation, and dissolution energy between the WC particles and the iron matrix. Thus, the stability of the interfacial reaction zone and bonding between the WC particles and the matrix is improved. By comparing the results with first-principles based calculations, composites doped with Nd have the best relative reaction interface bonding and mechanical properties.
Technical research on vacuum distillation to purify magnesium to 99.99% purity
Authors: Tian Yuan , Zhang Xiaopan , Qu Tao , Lyu Fei , Du Hao , Shi Lei , Yang Bin , Dai Yongnian 
Published: January 2021

Abstract
In this study, the distribution and evaporation principles of impurities in distilled magnesium metal were investigated using a low vacuum (8 × 104 Pa) distillation purification experiment and theoretical analysis. Provided all other factors remain unchanged (distillation time, pressure, and total area of evaporation), the optimum temperature for preparing high-purity Mg (99.99%) is 750 °C. A detailed analysis of purified Mg was obtained by inductively coupled plasma mass spectrometer (ICP-MS) for 10 major impurity elements. After distillation at 750 °C, low vapor pressure impurities in condensed magnesium, including Si, Mn, Al, Fe, Cu, Ni, and Sn were significantly reduced as other impurities were slightly reduced. Our analysis confirmed a decrease in the following impurities: Fe, Si, Mn, Cu, and Al were reduced from 21.8, 78.6, 68.4, 4.4, and 39.4 ppm to 1.2, 9.3, 6.0, 1.0, and 5.4 ppm, respectively; satisfying the 99.99% Mg standard. The evaporation rate and separation coefficient were calculated under experimental conditions. To better describe the distillation process of metallic magnesium under low vacuum conditions, the mean free path is also calculated in this study under actual conditions.
Cobalt-based alloy surfacing process optimization and surfacing material performance analysis
Authors: Xue Haitao , Zhou Dong , Guo WeiBing , Luan Xiaoping , Li Tao , Zhao Jianglong 
Published: January 2021

Abstract
In order to solve the problem of the failure of the UMCo50 process burner, the orthogonal test was used to optimize the UMCo50 cobalt-based alloy TIG surfacing process, better joint performance was obtained for welding current of 120 A, surfacing speed of 12 cm min−1, interpass temperature of 50 °C and surfacing layer of 2 ∼ 3 layers; Tungsten inert gas(TIG) welding and plasma transferred arc weld(PTAW) surfacing were used to surfacing UMCo50 welding wire and T800 cobalt-based alloy powder on UMCo50 base metal. The structure, hardness, high temperature wear resistance and heat corrosion resistance of the surfacing layer were compared. The results show that UMCo50 surfacing layers are α-Co (fcc) and ε-Co (hcp); T800 alloy surfacing layers are mainly Co3Mo2Si, CoMoSi, α-Co and ε-Co. The Laves phase in the T800 alloy surfacing layer significantly improves its hardness and high temperature wear resistance; Under the same test conditions, the heat and corrosion resistance of the UMCo50 surfacing layer is significantly better than that of the T800 surfacing layer.
Tension modeling and precise tension control of roll-to-roll system for flexible electronics
Authors: Jeong Jaehyeong , Gafurov Anton Nailevich , Park Pyoungwon , Kim Inyoung , Kim Hyun-Chang , Kang Dongwoo , Oh Dongho , Lee Taik-Min 
Published: January 2021

Abstract
This study proposes the design of a roll-to-roll system for flexible electronics that enables accurate and precise tension control. It analyzes the factors for change in the tension of a roll-to-roll system and develops a tension model for each section to successfully predict the tension that is applied to such a system, the sagging of film according to tension, and deformation due to residual stress. This series of modeling processes allow engineers to design a roll-to-roll system for flexible electronics. Both a velocity control method for the tension between in-feeder and out-feeder—where there is no change of roller radius—and torque control method for the tension in modules like the rewinder, where the roll radius changes, are proposed. A roll-to-roll system according to the proposed design procedure and tension control methods was manufactured and experimented on under various test conditions. The accuracy and precision of velocity control between the in-feeder and the out-feeder were 100.01% and 1.15%, respectively, whereas those of torque control between the out-feeder and the rewinder were 99.9% and 1.35%, respectively, both at one sigma. The experiments confirmed that the two proposed types of tension control methods were accurate and precise. The experimental result with a monitoring sensor showed that the modeling was valid and that an accurate roll-to-roll system minimizing tension reduction was built. This study successfully demonstrated roll-to-roll system design and control techniques that are applicable to various pieces of roll-to-roll process equipment.
How can the MHC mediate social odor via the microbiota community? A deep dive into mechanisms
Authors: Schubert Nadine , Nichols Hazel J , Winternitz Jamie C 
Published: January 2021

AbstractGenes of the major histocompatibility complex (MHC) have long been linked to odor signaling and recently researchers’ attention has focused on MHC structuring of microbial communities and how this may in turn impact odor. However, understanding of the mechanisms through which the MHC could affect the microbiota to produce a chemical signal that is both reliable and strong enough to ensure unambiguous transmission of behaviorally important information remains poor. This is largely because empirical studies are rare, predictions are unclear, and the underlying immunological mechanisms governing MHC–microbiota interactions are often neglected. Here, we review the immunological processes involving MHC class II (MHC-II) that could affect the commensal community. Focusing on immunological and medical research, we provide background knowledge for nonimmunologists by describing key players within the vertebrate immune system relating to MHC-II molecules (which present extracellular-derived peptides, and thus interact with extracellular commensal microbes). We then systematically review the literature investigating MHC–odor–microbiota interactions in animals and identify areas for future research. These insights will help to design studies that are able to explore the role of MHC-II and the microbiota in the behavior of wild populations in their natural environment and consequently propel this research area forward.