Fine Variation Research Articles

FINE ROOT DENSITY ACROSS SOIL PROFILES IN TROPICAL MOUNTAIN CLOUD FOREST AND ADJACENT MANAGED FIELDS IN VERACRUZ (MEXICO): INFLUENCE OF SOIL PROPERTIES

<p><strong>Background</strong>. Fine roots play a crucial in ecosystem functioning as they supply nutrients and water to plants and represent one of the main pathways for carbon transfer to the soil. <strong>Objective.</strong> This study assessed the vertical distribution of fine root density and analyzed its relationship with soil properties from a land use change perspective in three vegetation cover types (tropical mountain cloud forest, grassland, coffee crop). <strong>Methodology.</strong> Soil samples of known volume per horizon were extracted from the soil profile. In laboratory, fine roots (≤ 2 mm in diameter) were tweezers picked, rinsed with water and subsequently oven-dried (70 °C), and weighed. While, the soil was air-dried for chemical analysis. <strong>Results</strong>. In all soil profiles, average fine root density was greater in grassland (16.06 kg m<sup>-3</sup> ± 3.5, average ± SE) than in tropical mountain cloud forest (8.45 kg m<sup>-3</sup> ± 1.3), and coffee crop (2.73 kg m<sup>-3</sup> ± 0.44). On average, grassland, tropical mountain cloud forest, and coffee crop showed 78.4%, 73.2%, and 65%, respectively, of fine root density on the first soil horizon. <strong>Implications</strong>. Soil properties were strong predictors of fine root density variation. For example, there was a significant positive correlation between fine root density and soil organic carbon, total soil nitrogen, and effective cation exchange capacity (nutrient availability) in all vegetation covers. A significant negative correlation was observed between fine root density and pH in tropical mountain cloud forest but was not correlated in grassland and coffee crop. In all vegetation covers, there was a significant negative correlation between fine root density and soil bulk density and a strong positive correlation between it and soil water content at field capacity. <strong>Conclusion.</strong> This research contributes data that will improve our understanding of fine root density-soil interactions in a changing regional environment.</p>

Effects of chemical compositions in fine particles and their identified sources on hygroscopic growth factor during dry season in urban Guangzhou of South China

Knowledge of aerosol hygroscopicity is essential to assess visibility improvement and aerosol radiative forcing. Aerosol hygroscopicity is highly dependent on emission sources, while the hygroscopicity of different sources remains largely unexplored. In the current study, the hygroscopic growth factor (i.e., f(RH)) and relevant chemical compositions (e.g., water-soluble inorganic ions, carbonaceous fractions and elements) in fine particles were synchronously measured for nearly 3 months within 2019–2020 in an urban site of Guangzhou. The mean value (± standard deviation) of f(RH) at 70% RH was 1.50 (± 0.11). The diurnal cycle in aerosol hygroscopic growth strongly depended on the mass fraction of hydrophilic chemical compositions (e.g., SO42−, NO3− and NH4+) in fine particles and variation in contributions of aerosol sources. A Positive Matrix Factorization model was applied to distinguish the different hygroscopicity of specific source factors in a mixed aerosol. Secondary nitrate and secondary sulfate were more hydrophilic, whereas emissions from primary combustion processes (i.e., ship emission, coal combustion and road traffic) were less hygroscopic. Soil dust was almost insoluble. The hygroscopic growth of each source was parameterized that quantified the emission sources and f(RH) relationship for use of air quality and radiative transfer models either as input or as validation.

Intraspecific variation in molar topography of the early Eocene stem primate Microsyops latidens (Mammalia, ?Primates)

ABSTRACT Variation in postcanine teeth is relevant to answering questions about both taxonomy and diet. In such contexts, understanding the patterns and the amounts of variation present in a single species is fundamentally important. Here we use dental topographic analysis (DTA) to study variation in functional aspects of the lower second molar (n = 51) and lower fourth premolar (n = 41) in a large, stratigraphically controlled sample of the early Eocene stem primate Microsyops latidens, which permits study of fine scale variation through time in a single species, during a period of notable climatic change. To contextualize variation in M. latidens, we used DTA to study extant euarchontan taxa, representing three orders and seven families (n = 96). Previous study of M. latidens suggested that it was highly variable in size and lower molar morphology, potentially giving rise to later species of microsyopids. However, comparison with extant taxa suggests that the dental form of M. latidens shows low levels of intraspecific variation. The dental topography of M. latidens also does not reflect the previously postulated taxonomic split. Our results suggest instead that M. latidens likely did not undergo change in dental topography consistent with a shift in either dietary adaptive niche or ecospace. Taken together, our results suggest low levels of variation in dental form and potentially diet of M. latidens, indicating that this taxon likely remained within a single adaptive zone.

Tris-{Hydridotris(1-pyrazolyl)borato}lanthanide Complexes: Synthesis, Spectroscopy, Crystal Structure and Bonding Properties

Complexes of trivalent lanthanides (Ln) with the hydridotris(1-pyrazolyl)borato (Tp) ligand Ln[η3-HB(N2C3H3)3]3 (LnTp3) were subjected to a joint experimental–theoretical analysis. X-ray diffraction experiments have been performed on CeTp3, NdTp3, SmTp3, GdTp3, and TbTp3 in the nine-fold coordination and on DyTp3, HoTp3, ErTp3, TmTp3, YbTp3, and LuTp3 in the eight-fold coordination form. Density functional theory (DFT) calculations were carried out for all 15 LnTp3 complexes. They extended the X-ray diffraction data available on the LnTp3 compounds and facilitated a straightforward interpretation of trends in the structural parameters. As a result of the joint analysis, significant steric strain in the equatorial coordination sites of the nine-coordinate structures was recognized. Trends in the bonding properties were elucidated by energy decomposition and quantum theory of atoms in molecules (QTAIM) analysis of the electron density distribution. These results revealed the major electrostatic character of the Ln…Tp bonding and fine variation of charge transfer effects across the Ln row.

Quantitative measures and 3D shell models reveal interactions between bands and their position on growing snail shells.

The nature of shell growth in gastropods is useful because it preserves the ontogeny of shape, colour, and banding patterns, making them an ideal system for understanding how inherited variation develops, is established and maintained within a population. However, qualitative scoring of inherited shell characters means there is a lack of knowledge regarding the mechanisms that control fine variation. Here, we combine empirical measures of quantitative variation and 3D modeling of shells to understand how bands are placed and interact. By comparing five‐banded Cepaea individuals to shells lacking individual bands, we show that individual band absence has minor but significant impacts upon the position of remaining bands, implying that the locus controlling band presence/absence mainly acts after position is established. Then, we show that the shell grows at a similar rate, except for the region below the lowermost band. This demonstrates that wider bands of Cepaea are not an artifact of greater shell growth on the lower shell; they begin wider and grow at the same rate as other bands. Finally, we show that 3D models of shell shape and banding pattern, inferred from 2D photos using ShellShaper software, are congruent with empirical measures. This work therefore establishes a method that may be used for comparative studies of quantitative banding variation in snail shells, extraction of growth parameters, and morphometrics. In the future, studies that link the banding phenotype to the network of shell matrix proteins involved in biomineralization and patterning may ultimately aid in understanding the diversity of shell forms found in molluscs.

Intraclade Contact from an I-Language Perspective. The Noun Phrase in the Ligurian/Occitan amphizone

This article aims to compare some traits that characterise the syntax of the noun phrase in the Occitan/Ligurian amphizone (i.e., contact area) that lies at the border between southern France and northwestern Italy. The dialects spoken in this area differ in several syntactic traits that emerged in a situation of contact between dialects of different subgroups (Ligurian and Occitan), two roofing languages (Italian and French), and regional contact languages such as Genoese. In particular, I will elaborate on the syntax of mass and indefinite plural nouns, on the co-occurrence of determiners and possessives, and on the syntax of kinship terms. From an I-language perspective, the fine variation observed at the Occitan/Ligurian border raises two types of research questions: (a) which comparative concepts best capture the observed variation; (b) whether intraclade contact (i.e., contact between languages of the same branch) can contribute relevant evidence and arguments to the debate concerning the biological endowment of the language faculty.

Evaluation of various image transformation techniques for the delineation of coastal sand dune features in Tamil Nadu, South India

Image transformation techniques such as Principal Component Analysis, Minimum Noise Fraction and Independent Component Analysis were used for extracting information from the satellite image in various fields, but its application in landform mapping seems to be very less. The objective of the study is to demonstrate the viability of less explored image transformation techniques for delineating coastal dune complex and associated features using European satellite Sentinel 2 multispectral data. Based on the difference in lithology and vegetation cover the study sites has been chosen to extract coastal dune complex features such as dune ridges, dune with or without vegetation, swale with or without vegetation and water. Overall results of ICA shows enhanced visualization followed by PCA in bringing up the fine variations, identifying micro landforms within the dune complex from the optimum band combinations. Thus, sentinel data coupled with advanced image processing technique like ICA could identify maximum information about the boundaries and micro landform within the coastal sand dune complex in a cost-effective manner. However, in areas with dense vegetation cover none of these techniques has given good results in identifying the boundary or in identifying the micro landforms.

Application of factorial design to analyse the effect of brick powder size on biogas purification results

This study aims to know the effect of differences in grain size variation in fine and coarse bricks in the biogas purification process by reducing carbon dioxide gas levels using the adsorption method, so as to obtain the most suitable size to produce the most optimal purification results. In this research, the biogas purification process uses brick powder as an adsorbent, utilizing the alumina and silica content in bricks to absorb carbon dioxide gas. Testing the purified gas content in biogas using Gas Chromatography - Mass Spectrometry (GCMS). The data processing method used in this study was a factorial design method 23. The variations used in this study were the size of fine and coarse bricks, the purification time variation of 5 minutes and 20 minutes and the flow rate variation was 1 Liter minute−1 and 2 Liter minute−1. Fine size variation, a flow rate of 1 L Min−1 and a purification time of 20 minutes give the best results with the percentage level of carbon dioxide falling reaching 10.319%.

Compressive Strength, Permeability and Porosity Analysis of Pervious Concrete by Variation of Aggregate and Compacting Method

Pervious concrete is one of the innovation from conventional concrete which has interconnected void, thus enabling it to drain water. Compared to conventional concrete, pervious concrete has different physical and mechanical characteristics, but composed by the same material which is Ordinary Portland Cement (OPC), coarse aggregate, water, fine aggregate, and admixture. The use of fine aggregate in pervious concrete mixture is limited due to the fine aggregate can block the interconnected pores thus lowering the permeable ability of the pervious concrete. The objective of this research is to analyze the characteristics of the pervious concrete which is compressive strength, permeability, and porosity with variation of aggregate and compacting method. The pervious concrete mixture consists of 15%, 20%, and 25% of fine aggregate variations and standard rodding, proctor Hammer, and concrete vibrator as the compacting methods used. The amount of cement used on each mixture is 360 kg/m3, w/c = 0.3, and admixture as much as 2.8% of the cement used. The slump, compressive strength, and porosity test is based on ASTM Standard, while the permeability test is based on ACI Standard. The maximum compressive strength test result is 13.103 N/mm2 achieved by the mixture with 25% fine aggregates and compacted using concrete vibrator. The permeability test result ranged from 0.053 cm/s to 1.192 cm/s, and porosity ranged from 2.261% to 41.083%.

Identification of Exploration and Exploitation Balance in the Silkmoth Olfactory Search Behavior by Information-Theoretic Modeling.

Insects search for and find odor sources as their basic behaviors, such as when looking for food or a mate. This has motivated research to describe how they achieve such behavior under turbulent odor plumes with a small number of neurons. Among different insects, the silk moth has been studied owing to its clear motor response to olfactory input. In past studies, the “programmed behavior” of the silk moth has been modeled as the average duration of a sequence of maneuvers based on the duration of periods without odor hits. However, this model does not fully represent the fine variations in their behavior. In this study, we used silk moth olfactory search trajectories from an experimental virtual reality device. We achieved an accurate input by using optogenetic silk moths that react to blue light. We then modeled such trajectories as a probabilistic learning agent with a belief of possible source locations. We found that maneuvers mismatching the programmed behavior are related to larger entropy decrease, that is, they are more likely to increase the certainty of the belief. This implies that silkmoths include some stochasticity in their search policy to balance the exploration and exploitation of olfactory information by matching or mismatching the programmed behavior model. We believe that this information-theoretic representation of insect behavior is important for the future implementation of olfactory searches in artificial agents such as robots.

Tolerance as Implicit Order: Militias and Sexual Violence as Practice in Indonesian Counterinsurgency Operations

ABSTRACT What conditions precipitate militia-inflicted sexual violence during counterinsurgency operations? In our article, we expand on the sexual violence as practice framework by focusing on the issue of commander's tolerance as a form of implicit order. Specifically, we argue that militia-inflicted sexual violence is amplified by two interrelated conditions – the link to the government security forces and the autonomy permitted to the militias in conflict zones. Thus, we refine the logic of sexual violence as practice to understand the finer variations of militia-committed violence. We elaborate our explanations by analyzing Indonesia's peripheral operations in East Timor, Aceh and West Papua.

New Insights Into the Control of Visible Gold Fineness and Deposition: A Case Study of the Sanshandao Gold Deposit, Jiaodong, China

Abstract Mineralogical distribution, textures, electron probe microanalysis of visible gold, laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) trace element analysis of pyrite, and LA-multicollector (MC-)ICP-MS sulfur isotope analysis of sulfide minerals are examined in an ore zone extending obliquely to –4 km depth in the Sanshandao gold deposit Jiaodong, China. We relate these results to the temporal and spatial ore-forming processes in the deposit to further elucidate the controls on the deposition of visible Au and fineness variation. Two generations of Au mineralization are identified. The early generation is represented by beresitization and quartz-pyrite veins in which visible Au grains are associated with pyrite (Py1 and Py2) and are characterized by high fineness [729–961; fineness = 1000×Au/(Au+Ag)]. Py1 and Py2 are both enriched in Co, Ni, and Bi and depleted in As and Au. Texturally, gold and pyrite are pristine crystals, homogeneous in composition. These features are attributed to the sulfidation of the granitic wallrock (fluid/rock interaction) that effectively destabilizes Au in the ore-forming fluids during pyrite deposition. Fineness decreases continuously from 870 at –2650 m depth to 752 at –420 m depth. The Co and Ni contents of Py1 and Py2 decrease significantly from –4000 m to –420 m depth, whereas the As contents increase. The mean δ34S values of Py1 increase from 10.5 to 11.8‰. The spatial variations are interpreted to be related to gradual cooling, decompression, and an enhanced degree of fluid/rock interaction with decreasing depth, which facilitated the initiation of visible gold mineralization at ca. –2700 m depth. The late generation of Au mineralization is represented by quartz-polysulfide veins in which visible Au grains are associated with multiple sulfide minerals (Py3, galena, chalcopyrite, arsenopyrite, and sphalerite). It is characterized by low fineness (549–719), and heterogeneous textures with Ag-rich parts (218–421). Py3, occurring as the rim of pyrite grain, is interpreted to form by replacement via a dissolution-reprecipitation reaction. Py3 is distinctly enriched in As (median of 10 000 ppm) and Au (2.2 ppm), but depleted in Co, Ni, and Bi. The δ34S values of the polysulfide minerals decrease sharply by 4 to 5‰ at depths from –1909 to –1450 m. These features are interpreted to be generated by significant decompression and phase separation of fluid, where most ore elements (e.g., Au, Ag, As, and base metal elements) are destabilized. Our study suggests that remobilization did not affect the generation of visible Au mineralization at Sanshandao.

Microstructure and properties of polycrystalline PZT films obtained by RF magnetron sputtering with fine variation of the composition near morphotropic phase boundary

The article discusses the possibilities of fine composition variation of polycrystalline PZT films at the morphotropic phase boundary. The composition of thin films prepared by RF magnetron sputtering of a ceramic target of stoichiometric composition PbZr0.54Ti0.46O3 was varied by changing the distance from the target to the substrate in the range of 30–70 mm. This made it possible to change the composition by ~1.5%. The study focused on the dielectric properties of the formed self-polarized films. The study found that the resistance to external electric fields depends on the conditions of film preparation.

Offices and Officers of the Constitution, Part I: An Introduction

In this Article, we introduce our planned ten-part series that provides the first comprehensive examination of the offices and officers of the Constitution. This series will explain the original public meaning of twelve clauses of the Constitution that refer to six categories of offices and officers. First, the phrase “officers of the United States” refers to appointed positions in the Executive and Judicial Branches. Second, the phrase “office . . . under the United States” refers to appointed positions in the Executive and Judicial Branches, and also includes non-apex appointed positions in the Legislative Branch. Third, the phrase “Office under the Authority of the United States” includes all “office[s] . . . under the United States,” and extends further to include a broader category of irregular positions. Fourth, the phrase “Officer” of “the Government of the United States” refers to the presiding officers identified in the Constitution. Fifth, the word “Officer,” as used in the Succession Clause, refers to those who hold “office . . . under the United States” and those who are “Officer[s]” of “the Government of the United States.” Sixth, the phrase “Office or Public Trust under the United States” encompasses two categories of positions: “Office[s] . . . under the United States” and “Public Trusts under the United States.” The former category includes appointed positions in all three branches; the latter category includes federal officials who are not subject to direction or supervision by a higher federal authority in the normal course of their duties. Our categorization excludes elected officials from the categories “officer of the United States” and “office . . . under the United States.” Not everyone agrees with our Minimalist View. Professors Akhil Reed Amar and Vikram David Amar have put forward an Intermediate View: the elected President is an “officer of the United States,” but members of Congress are not. Professor Zephyr Teachout advances a Maximalist View: elected and appointed positions, in all three branches, are “offices” and “officers.” And some scholars may embrace a fourth approach. Under a Clause-Bound View, fine variations in the Constitution’s text should not be used to distinguish different kinds of offices and officers. Rather, this view purports to be guided by the specific purposes that animate individual clauses. As a general matter, it is impossible to reject any of these four approaches with 100% certainty. Instead, we make a limited claim: our approach, the Minimalist View, is better than its known rivals. The Framers chose different “office”- and “officer”-language in different clauses of the Constitution. These provisions were altered throughout the Convention to standardize and harmonize how the Constitution refers to offices and officers. And the conduct of President Washington, his cabinet, and the First Congress was consistent with the Minimalist View. This evidence undermines the Intermediate, Maximalist, and Clause-Bound Approaches. Part I, this Article, introduces our planned ten-part series. Part II will expound on the four approaches to understand the Constitution’s “office”- and “officer”-language. Part III will analyze the phrase “officers of the United States,” which appears in the Appointments Clause, the Commissions Clause, the Impeachment Clause, and the Oath or Affirmation Clause. Part IV will trace the history of the “Office . . . under the United States” drafting convention. Part V will consider the meaning of the phrase “office . . . under the United States,” which appears in the Incompatibility Clause, the Impeachment Disqualification Clause, the Foreign Emoluments Clause, and the Elector Incompatibility Clause. Part VI will turn to the phrase “Office under the Authority of the United States,” which appears in the Ineligibility Clause. Part VII will study the Religious Test Clause, which uses the phrase “Office or Public Trust under the United States.” Part VIII will focus on the phrase “Officer” of “the Government of the United States” in the Necessary and Proper Clause. Part IX will elaborate on the word “Officer,” standing alone and unmodified, in the Succession Clause. Part X will conclude the series.

Exposure to crime and pupils’ outcomes: evidence from London

Estimation of unintended costs of crime is scarce, although essential. This paper investigates a prominent indirect cost of crime, i.e. the effect of exposure to crime on achievement of pupils enrolled in primary school. I employ novel geo-referenced data on the universe of crimes from police records in London. The analysis takes advantage of the very fine spatial variation in crimes and in pupils’ residences, precisely measuring the exposure to crime in the surroundings of pupils’ homes. By exploiting the within-school variation in crime, I find that crime occurring where pupils live lowers impact on pupils’ achievement at final exams of primary school. The heterogeneity analysis shows that high-ability and wealthy students are those who suffer the most from exposure to crime. I find evidence of decreasing marginal sensitivity to crime, as pupils living in less criminal areas suffer the most from exposure to crime. Overall, I interpret this evidence as consistent with a story of scarring effect and adaptation.

A Comprehensive Comparative Evaluation of Machine Learning Algorithms on Facebook Comment Dataset

Data mining is an emerging technique with its application in various areas such as health care, education, travel, social media, and banking. The data can be either labeled or unlabeled. When it comes to social media, the various platforms generate an infinite amount of data. This data can be of immense importance as a lot of hidden information can be discovered after data mining. In this paper, machine-learning algorithms such as Decision Trees, SVM, and Linear Regression and their variants are applied on the Facebook comment dataset, obtained from the UCI machine learning repository. The dataset has 40,949 instances and 54 attributes. The goal is to predict the number of comments a Facebook post will get based on various conditions. The results indicate that the Fine Gaussian SVM variation of SVM yielded the highest prediction accuracy. The evaluation was done on different parameters such as average testing accuracy (%), Root Mean Square Error (RMSE), R- Squared, Mean Square Error (MSE), Mean Absolute Error (MAE), prediction speed (Obs/sec), and training time (Machine cycle). It is concluded that SVM is an ideal choice to solve prediction problems associated with social media data.

Analysis, Quantification, and Discussion of the Approximations Introduced by Pulsed 3-D LiDARs

Light detection and rangings (LiDARs) are considered essential for the environmental sensing required by most advanced driver assistance system (ADAS), including autonomous driving. This has led to significant investments resulted in the availability of countless measuring systems that are increasingly performing and less expensive. Nevertheless, the extremely high speed of light still leads to a nonnegligible quantization error in the direct time-of-flight (ToF) measure at the base of pulsed LiDARs—the leading technology for automotive applications. Hence, pulsed 3-D LiDARs analyze the surrounding by approximating and deforming it on concentric spheres whose radii are quantized with a quantization step that, for most commercial systems, is on the order of some centimeters. The deformation and error introduced by such quantization can thus be significant. In this study, we point out the approximations and assumptions intrinsic to 3-D LiDARs and propose a measurement procedure that, through the analysis of the fine variations of the target position, allows an accurate investigation of the axial resolution and error—probably among the few limitations still affecting this technology. To the best of our knowledge, this is the first study focused on the detailed analysis of the quantization error in 3-D LiDARs. The proposed method has been tested on one of the most popular 3-D LiDARs, namely the MRS 6000 by Sick. The obtained results revealed for the MRS 6000 a quantization step of about 6 cm (ToF quantization of about 0.4 ns) and an axial error normally distributed with experimental standard deviation of about 30 mm.

About the Free and Forced Nutation: The Daily Nutation

To explain the nutation phenomenon, Euler chose a geocentric frame of coordinates to present his dynamical equations. In accordance with his formulas, the nutation is caused by a momentum relative to the Earth's center, due to certain external forces. Further, Poinsot presented a special case of the Euler's equations, when any momentum of those certain external forces does not exist. Due to a problematic approximation, Poinsot announced that in this case may take place a nutation period of 10 month, named “free period”, to distinguish it from the Euler's dynamical solution, known as “forced nutation”. After Poinsot, the notion of “free nutation” was extended also to those nutation phenomena which have only a geophysical origin, without a momentum of certain external forces. Usually, the daily nutation is considered as being a free nutation phenomenon. In order to search for a forced daily nutation component, the daily trajectory of the Earth-Moon barycenter inside the Earth is used (a simple scheme of this barycenter trajectory is presented in a geocentric system of axes). Finally, if the ecliptic line is accepted to be described by the Earth-Moon barycenter, it must be accepted, too, that a torque due the Sun and the Moon acts during a sideral day interval on diurnal Earth rotation around its axis. Due to the small value of the nutation constant, a period of 18,6 years is needed to correctly and completely detect the forced daily nutation; this phenomenon permanently presents very fine variations depending on the longitude of the ascending lunar node, the Moon’s declination and the Sun’s ecliptic longitude.

Topography as a factor driving small-scale variation in tree fine root traits and root functional diversity in a species-rich tropical montane forest.

We investigated the variation in tree fine root traits and their functional diversity along a local topographic gradient in a Neotropical montane forest to test if fine root trait variation along the gradient is consistent with the predictions of the root economics spectrum on a shift from acquisitive to conservative traits with decreasing resource supply. We measured five fine root functional traits in 179 randomly selected tree individuals of 100 species and analysed the variation of single traits (using Bayesian phylogenetic multilevel models) and of functional trait diversity with small-scale topography. Fine roots exhibited more conservative traits (thicker diameters, lower specific root length and nitrogen concentration) at upper slope compared with lower slope positions, but the largest proportion of variation (40-80%) was explained by species identity and phylogeny. Fine root functional diversity decreased towards the upper slopes. Our results suggest that local topography and the related soil fertility and moisture gradients cause considerable small-scale variation in fine root traits and functional diversity along tropical mountain slopes, with conservative root traits and greater trait convergence being associated with less favourable soil conditions due to environmental filtering. We provide evidence of a high degree of phylogenetic conservation in fine root traits.

Effect of variations in the composition and size of red sand grains on the quality of K-225 concrete

The effect of variations in the composition and size of red sand grains on the solid quality made in the form of a 15×15×15 cm cubes were investigated. By implementing the standard of SNI K-225 which is a mixture of 1:1.9:2.8 with FAS 0.6 and the composition of red sand consisting of 0, 2, 4, 5, and 6.5% of the weight of fine aggregate and variations in the size of red sand grains of 80, 100, and 120 mesh, the concrete was being treated in a water bath for 28 days. It was tested by the method of water absorption, compressive strength test, Scanning Electron Microscope (SEM) and X-Ray Diffraction (XRD). The test result of SEM indicated that variations of both the composition and size of red sand grains affect the porosity of the concrete. XRD test obtained Ca(OH)2, CaCO3 and SiO2, as the highest intensity element, and the similar crystal structure formed is hexagonal. The maximum compressive strength of the concrete on the composition of 4% with a grain size of 80 mesh red sand that is 32.3 MPa with is linear with the results of testing the water absorption of concrete along with the decreasing variations in the size of red sand grain.