bluuebunny/crossref_metadata_2025 huggingface dataset:
Generalizing game-changing species across microbial communities
Authors: Deng Jie , Angulo Marco Tulio , Saavedra Serguei
Published: June 2021

Microbes form multispecies communities that play essential roles in our environment and health. Not surprisingly, there is an increasing need for understanding if certain invader species will modify a given microbial community, producing either a desired or undesired change in the observed collection of resident species. However, the complex interactions that species can establish between each other and the diverse external factors underlying their dynamics have made constructing such understanding context-specific. Here we integrate tractable theoretical systems with tractable experimental systems to find general conditions under which non-resident species can change the collection of resident communities—game-changing species. We show that non-resident colonizers are more likely to be game-changers than transients, whereas game-changers are more likely to suppress than to promote resident species. Importantly, we find general heuristic rules for game-changers under controlled environments by integrating mutual invasibility theory with in vitro experimental systems, and general heuristic rules under changing environments by integrating structuralist theory with in vivo experimental systems. Despite the strong context-dependency of microbial communities, our work shows that under an appropriate integration of tractable theoretical and experimental systems, it is possible to unveil regularities that can then be potentially extended to understand the behavior of complex natural communities.
Potential SiX (X = N, P, As, Sb, Bi) homo-bilayers for visible-light photocatalyst applications
Authors: Somaiya Radha N , Singh Deobrat , Sonvane Yogesh , Gupta Sanjeev K. , Ahuja Rajeev
Published: June 2021

Identifying low-dimensional materials as photocatalysts for photocatalytic water splitting application is a challenge and need for future energy demand. The electrocatalytic activity towards OER/ORR was investigated of the SiX binary compounds.
Preparation of functional magnetic porous organic polymer as sorbent for mercury speciation followed by HPLC-ICP-MS analysis
Authors: He Yifeng , He Man , Chen Beibei , Hu Bin
Published: June 2021

The sulfur containing functional magnetic porous organic polymer based MSPE-HPLC-ICP-MS shows high enrichment factor and low detection limits for mercury speciation.
Necklace-like NiCo2O4@carbon composite nanofibers derived from metal–organic framework compounds for high-rate lithium storage
Authors: Long Zhiwen , Li Rongrong , Dai Zixin , Shi Chu , Wu Caiqin , Wei Qufu , Qiao Hui , Wang Keliang , Liu Ke
Published: June 2021

Necklace-like NiCo2O4@carbon composite nanofibers with an excellent cycling performance exhibit negligible volume expansion and structural integrity even after 500 cycles.
Competing hydrogen evolution reaction: a challenge in electrocatalytic nitrogen fixation
Authors: Chen Jiangyue , Cheng Hui , Ding Liang-Xin , Wang Haihui
Published: June 2021

The electrocatalytic N2 reduction reaction (NRR) under mild conditions is a promising candidate for NH3 synthesis. Nevertheless, competition between the H2 evolution reaction and the NRR results in a low NH3 yield rate and poor faradaic efficiency.
Heterogeneous ZnO-containing catalysts for efficient biodiesel production
Authors: Wang Anping , Quan Wenxuan , Zhang Heng , Li Hu , Yang Song
Published: June 2021

This review introduces recent advances in the catalytic conversion of oils into biodiesel using ZnO functional composite materials.
Nickel hydroxide as a non-noble metal co-catalyst decorated on Cd0.5Zn0.5S solid solution for enhanced hydrogen evolution
Authors: Chen Dan , Xu Yao , Zhang Yingying , Sheng Wenyu , Qian Guangren
Published: June 2021

This study researched the mechanism of a co-catalyst composite, providing new possibilities for non-noble metal photocatalysts.
Nonfullerene acceptors for P3HT-based organic solar cells
Authors: Chatterjee Shreyam , Jinnai Seihou , Ie Yutaka
Published: June 2021

Poly(3-hexylthiophene) (P3HT) is a promising donor for the large-scale organic solar cell fabrication in a cost-effective way. A series of nonfullerene acceptors compatible with P3HT are summarized in this review.
Composition and dimension dependent static and dynamic stabilities of inorganic mixed halide antimony perovskites
Authors: Yang Jack
Published: June 2021

We systematically show that alloys of low-dimensional mixed-halide antimony perovskites exhibit weaker vibrational anharmonicity and electron–phonon coupling strengths, which may enhance their photo-stabilities compared to 3D halide perovskites.
CAPOS: The bulge Cluster APOgee Survey
Authors: Geisler D. , Villanova S. , O’Connell J. E. , Cohen R. E. , Moni Bidin C. , Fernández-Trincado J. G. , Muñoz C. , Minniti D. , Zoccali M. , Rojas-Arriagada A. , Contreras Ramos R. , Catelan M. , Mauro F. , Cortés C. , Ferreira Lopes C. E. , Arentsen A. , Starkenburg E. , Martin N. F. , Tang B. , Parisi C. , Alonso-García J. , Gran F. , Cunha K. , Smith V. , Majewski S. R. , Jönsson H. , García-Hernández D. A. , Horta D. , Mészáros S. , Monaco L. , Monachesi A. , Muñoz R. R. , Brownstein J. , Beers T. C. , Lane R. R. , Barbuy B. , Sobeck J. , Henao L. , González-Díaz D. , Miranda R. E. , Reinarz Y. , Santander T. A.
Published: June 2021

Context.Bulge globular clusters (BGCs) are exceptional tracers of the formation and chemodynamical evolution of this oldest Galactic component. However, until now, observational difficulties have prevented us from taking full advantage of these powerful Galactic archeological tools.

Aims.CAPOS, the bulge Cluster APOgee Survey, addresses this key topic by observing a large number of BGCs, most of which have only been poorly studied previously. Even their most basic parameters, such as metallicity, [α/Fe], and radial velocity, are generally very uncertain. We aim to obtain accurate mean values for these parameters, as well as abundances for a number of other elements, and explore multiple populations. In this first paper, we describe the CAPOS project and present initial results for seven BGCs.

Methods.CAPOS uses the APOGEE-2S spectrograph observing in theHband to penetrate obscuring dust toward the bulge. For this initial paper, we use abundances derived from ASPCAP, the APOGEE pipeline.

Results.We derive mean [Fe/H] values of −0.85 ± 0.04 (Terzan 2), −1.40 ± 0.05 (Terzan 4), −1.20 ± 0.10 (HP 1), −1.40 ± 0.07 (Terzan 9), −1.07 ± 0.09 (Djorg 2), −1.06 ± 0.06 (NGC 6540), and −1.11 ± 0.04 (NGC 6642) from three to ten stars per cluster. We determine mean abundances for eleven other elements plus the mean [α/Fe] and radial velocity. CAPOS clusters significantly increase the sample of well-studied Main Bulge globular clusters (GCs) and also extend them to lower metallicity. We reinforce the finding that Main Bulge and Main Disk GCs, formed in situ, have [Si/Fe] abundances slightly higher than their accreted counterparts at the same metallicity. We investigate multiple populations and find our clusters generally follow the light-element (anti)correlation trends of previous studies of GCs of similar metallicity. We finally explore the abundances of the iron-peak elements Mn and Ni and compare their trends with field populations.

Conclusions.CAPOS is proving to be an unprecedented resource for greatly improving our knowledge of the formation and evolution of BGCs and the bulge itself.
MOND-like behavior in the Dirac–Milne universe
Authors: Chardin Gabriel , Dubois Yohan , Manfredi Giovanni , Miller Bruce , Stahl Clément
Published: June 2021

Aims.Observational data show that the observed luminous matter is not sufficient to explain several features of the present universe, from gravitational structure formation to the rotational velocities in galaxies and clusters. The mainstream explanation is that the missing mass, although gravitationally active, interacts very weakly with ordinary matter. Competing explanations involve changing the laws of gravity at low accelerations, as in MOdified Newtonian Dynamics (MOND). Here, we suggest that the Dirac-Milne cosmology, a matter-antimatter symmetric cosmology where the two components repel each other, is capable of accounting for such an apparent modification of the Newtonian law, without invoking dark matter.

Methods.Using a simple analytical approximation and 1D and 3D simulations, we study rotation curves and virial velocities and compare the mass observed in the simulations to the mass derived assuming Newtonian gravity. Using a modified version of theRAMSEScode, we study the Faber-Jackson scaling relation and the intensity of the additional gravitational field created by antimatter clouds.

Results.We show that, in the Dirac-Milne universe, rotation curves are generically flat beyond a characteristic distance of ≈2.5 virial radii, and that the Tully-Fisher and Faber-Jackson scaling relations with an exponent ≈3 are satisfied. We show that the mass derived from the rotation curves assuming Newtonian gravity is systematically overestimated compared to the mass really present. In addition, the Dirac-Milne universe, featuring a polarization between its matter and antimatter components, presents a behavior similar to that of MOND, characterized by an additional surface gravity compared to the Newtonian case. We show that in the Dirac-Milne universe, at the present epoch, the intensity of the additional gravitational fieldgamdue to the presence of clouds of antimatter is on the order of a few 10−11m s−2, similar to the characteristic acceleration of MOND. We study the evolution of this additional accelerationgamand show that it depends on the redshift, and it is therefore not a fundamental constant.

Conclusions.Combined with its known concordance properties on the SNIa luminosity distance, age, nucleosynthesis, and structure formation, the Dirac-Milne cosmology may then represent an interesting alternative to the standard cosmological model ΛCDM, MOND, and other scenarios for explaining the dark matter (or missing gravity) and dark energy conundrum.
Uniform null controllability for parabolic equations with discontinuous diffusion coefficients
Authors: Dardé Jérémi , Ervedoza Sylvain , Morales Roberto
Published: June 2021

In this article, we study the null-controllability of a heat equation in a domain composed of two media of different constant conductivities. In particular, we are interested in the behavior of the system when the conductivity of the medium on which the control does not act goes to infinity, corresponding at the limit to a perfectly conductive medium. In that case, and under suitable geometric conditions, we obtain a uniform null-controllability result. Our strategy is based on the analysis of the controllability of the corresponding wave operators and the transmutation technique, which explains the geometric conditions.
Dossier « Politiques locales de l’énergie : un renouveau sous contraintes » – Expérimenter une transition énergétique coopérative : épreuves et innovations territoriales collectives autour d’un projet de « centrale photovoltaïque villageoise » (Rhône-Alpes, France)
Authors: Fontaine Antoine
Published: June 2021

Cet article porte sur le développement de projets photovoltaïques citoyens coopératifs en Rhône-Alpes au début des années 2010, dans le contexte d’une politique nationale alors davantage favorable au développement de projets individuels et privés. La première partie de l’article souligne que ces projets émergent de dynamiques et de problématiques à la fois nationales, régionales et locales qui ouvrent simultanément une fenêtre d’opportunité. Dans la seconde partie, l’article analyse les épreuves traversées par l’un de ces collectifs lorsqu’il tente d’ouvrir la politique incitative nationale pour le photovoltaïque à des enjeux territoriaux qu’elle ne prend pas en compte (redistribution et réinvestissement des revenus solaires, innovation paysagère et architecturale). L’analyse donne à voir un collectif innovant qui traverse des épreuves multiples en tentant d’initier une trajectoire territoriale de transition énergétique qu’il juge plus équitable que celle alors à l’œuvre.
Semiconducting character of LaN: Magnitude of the bandgap and origin of the electrical conductivity
Authors: Deng Zihao , Kioupakis Emmanouil
Published: June 2021

Lanthanum nitride (LaN) has attracted research interest in catalysis due to its ability to activate the triple bonds of N2 molecules, enabling efficient and cost-effective synthesis of ammonia from N2 gas. While exciting progress has been made to use LaN in functional applications, the electronic character of LaN (metallic, semi-metallic, or semiconducting) and magnitude of its bandgap have so far not been conclusively determined. Here, we investigate the electronic properties of LaN with hybrid density functional theory calculations. In contrast to previous claims that LaN is semi-metallic, our calculations show that LaN is a direct-bandgap semiconductor with a bandgap value of 0.62 eV at the X point of the Brillouin zone. The dispersive character of the bands near the band edges leads to light electron and hole effective masses, making LaN promising for electronic and optoelectronic applications. Our calculations also reveal that nitrogen vacancies and substitutional oxygen atoms are two unintentional shallow donors with low formation energies that can explain the origin of the previously reported electrical conductivity. Our calculations clarify the semiconducting nature of LaN and reveal candidate unintentional point defects that are likely responsible for its measured electrical conductivity.
The challenges of developing resilient perennial pastures for a Mediterranean environment – a review for Western Australia
Authors: Moore G. A. , Sanford P. , Dolling P. J. , Real D.
Published: June 2021

Perennial pastures are the dominant feedbase in many regions of the world, and offer several advantages when compared with an annual pasture system. In Western Australia (WA) there has been a concerted effort over seven decades to develop new perennial pasture options and expand the adoption of suitable species. The agricultural region of WA (i.e. south-western Australia) is characterised by a Mediterranean climate where the 5–7 month summer drought has proved a considerable challenge with only a small number of the many promising species being adopted commercially. Research, development, and extension have covered a wide range of herbaceous perennial legumes, leguminous and native shrubs, herbs, and temperate and warm season grasses. This paper reviews the literature to determine whether a perennial pasture must satisfy the following criteria to be successful and widely adopted in south-western Australia: (i) sourced from a similar Mediterranean environment and adapted to the target soils; (ii) have a relative advantage over the annual-based system it replaces; (iii) a robust management package; and (iv) a viable seed supply. The findings of this review highlight that perennial pastures must indeed satisfy multiple criteria to be commercially successful. Notably, the requirement for the source of the germplasm to have a good match between climate and soils is less clear because some of the commercially successful species come from diverse environments. We conclude with some key learnings for future perennial pasture development as climate change intensifies the research challenge and the drive for producers to adapt.
Gravitational SIMPs
Authors: Barman Basabendu , Bernal Nicolás
Published: June 2021

We study the impact of thermalization and number-changing processes in the dark sector on the yield of gravitationally produced dark matter (DM).
We take into account the DM production through the s-channel exchange of a massless graviton both from the scattering of inflatons during the reheating era, and from the Standard Model bath via the UV freeze-in mechanism. By considering the DM to be a scalar, a fermion, and a vector boson we show, in a model-independent way, that DM self-interaction gives rise to a larger viable parameter space by allowing lower reheating temperature to be compatible with Planck observed relic abundance. As an example, we also discuss our findings in the context of the ℤ2-symmetric scalar singlet DM model.
Ultralocality and slow contraction
Authors: Ijjas Anna , Sullivan Andrew P. , Pretorius Frans , Steinhardt Paul J. , Cook William G.
Published: June 2021

We study the detailed process by which slow contraction smooths and flattens the universe using an improved numerical relativity code that accepts initial conditions with non-perturbative
deviations from homogeneity and isotropy along two independent spatial directions.
Contrary to common descriptions of the early universe,
we find that the geometry first rapidly converges to an inhomogeneous, spatially-curved and anisotropic ultralocal state in which all spatial
gradient contributions to the equations of motion decrease as an exponential in time to negligible values. This is followed by a second stage in which the geometry converges to a homogeneous, spatially flat and isotropic spacetime. In particular, the decay appears to follow the same history whether the entire spacetime or only parts of it are smoothed by the end of slow contraction.
Modification of short-range repulsive interactions in ReaxFF reactive force field for Fe–Ni–Al alloy*
Authors: Chen Huaqiang , Lang Lin , Yi Shuaiyu , Du Jinlong , Liu Guangdong , Liu Lixia , Wang Yufei , Wang Yuehui , Deng Huiqiu , Fu Engang
Published: June 2021

The short-range repulsive interactions of any force field must be modified to be applicable for high energy atomic collisions because of extremely far from equilibrium state when used in molecular dynamics (MD) simulations. In this work, the short-range repulsive interaction of a reactive force field (ReaxFF), describing Fe–Ni–Al alloy system, is well modified by adding a tabulated function form based on Ziegler–Biersack–Littmark (ZBL) potential. The modified interaction covers three ranges, including short range, smooth range, and primordial range. The short range is totally predominated by ZBL potential. The primordial range means the interactions in this range is the as-is ReaxFF with no changes. The smooth range links the short-range ZBL and primordial-range ReaxFF potentials with a taper function. Both energies and forces are guaranteed to be continuous, and qualified to the consistent requirement in LAMMPS. This modified force field is applicable for simulations of energetic particle bombardments and reproducing point defects' booming and recombination effectively.
Effect of staggered array structure on the flow field of micro gas chromatographic column
Authors: Ge Daohan , Hu Zhou , Zhang Liqiang , Zhu Shining
Published: June 2021

A new design of staggered array semi-packed micro gas chromatographic column was presented based on the micro electromechanical system (MEMS) technology. It was a sensor for gas sample analysis. The internal velocity fields of ten types of semi-packed micro gas chromatographic column were studied. The effects of array spacing and dislocation spacing on the flow field distribution were investigated. The results show that on the basis of ensuring the formation of virtual wall, with the increase of array spacing, the maximum velocity difference between the flow channels in the vertical direction decreases gradually, but the velocity difference in the flow channels a and b increases. When the inlet velocity was set to be 0.18 m/s, the maximum velocity difference in the channel of the staggered semi-packed micro gas chromatography column 3 (CSAC3) was 0.05610 m/s. The maximum velocity difference in the channel a was 0.09160 m/s. The maximum velocity difference in the channel b was 0.02401 m/s. CSAC3 had a more uniform velocity field distribution, which can effectively suppress the laminar flow effect during chromatographic separation, and had a smaller pressure distribution, which puts forward lower requirements for carrier gas system. The staggered array semi-packed micro gas chromatography column proposed in this paper can effectively improve the velocity field distribution and pressure distribution in the channel, and provide a theoretical basis for the design of the new micro gas chromatography column structure.
Modeling of program-target organization and management of competitiveness of territorial reproduction systems in construction
Authors: Krygina A M , Krygina N M , Shchenyatskaya M A , Oberemok M I
Published: June 2021

Abstract.This study examines modern theoretical and methodological approaches to solving the problem of program-target organization and management of meso-competitiveness in construction as a prerequisite for effective practical implementation of transformational development according to key monitoring indicators such as productivity, organizational and technical reliability. Taking into account the inevitability of the involvement of territorial construction complexes in the reproduction processes as a meso-economic competitive territorial-reproduction construction system, the article substantiates the need to develop special program-target methods for regulating these processes. It shows the expediency of combining the competitiveness, productivity of territorial construction complexes and reproduction processes in construction by the program-target method. The adopted programs should essentially become mortgage and investment programs for long-term management of the reproduction of territorial-portfolio land and property complexes in various industries and infrastructures. The study presents the efficiency of using consortium-type structures to implement the idea of forming high-performance cluster systems in construction at regional and inter-regional levels. Mortgage and investment programs for sustainable development of residential construction should become a tool for managing the process of transformational regulation of competitiveness from its local level to the interregional and international levels with a clear system organization.
The problems of historical settlements’ enhancement and the possible solutions
Authors: Blagovidova N G , Iudina N V
Published: June 2021

The paper deals with the problems of historical settlements, which lead to the loss of their status and critical violations of the historical environment. The author analyzes the problems of historical settlements and their particularly vulnerable type – small formations – including social, political, economic, and scientific research. The author points out the need for complex innovative approaches that ensure not only the material restoration, but also the functional development of the historical environment, the introduction of new functions. The tools of working with the historical urban environment and its active functional inclusion in the modern discourse, models of increasing the value characteristics of urban objects, as well as the principles of implementing local potentials, which are laid in the basis of a holistic methodology, are considered. A strategy is proposed that solves the extremely acute issue of the urban significance of historical and cultural monuments on the basis of management tools and spatial planning, and tactical steps for its implementation are highlighted. The methodology obtained as a result of the study can be used as a basis for a national program aimed at developing and strengthening the social and economic role of small historical cities in the country’s settlement system.
Capillary-absorbed moisture transfer in a multiphase soil medium considering the load potential
Authors: Tedeev T R
Published: June 2021

The work presents an analytical solution to the equation of moisture permeability of structural varieties of capillary-absorbed moisture in a multiphase soil system with incomplete water saturation considering the influence of load potential. Researches were carried out and the influence of external load on the moisture profile in a multiphase system, the rate of moisture transfer of a discontinuous flow in general, and the rate of moisture propagation of the wetting boundaries have been shown. For a comparative analysis of the indicators of moisture transfer, functional relationships between the potential and pressure of the structural varieties of capillary-absorbed ground moisture are presented: capillary-gravity, proper-capillary and capillary-osmotic components of ground moisture. In the interval of incomplete water saturation, an attempt was made to create the foundations of capillary moisture transfer in the soil environment considering both the external distributed load and the own weight of the soil.
Features of wooden buildings in Tomsk
Authors: Babinovich N U , Sitnikova E V
Published: June 2021

The article is devoted to analysis and systematization of classical wooden buildings in Tomsk. The relevance of the work is due to the problems of preserving the valuable of Tomsk historical and architectural heritage and this topic is poorly known . Wooden buildings in the classicism style were widely spread in the nineteenth century. They were classified as a residential development and were subjected to reconstruction and demolition in the Soviet period. Currently the wooden classical buildings are the most ancient and already quite rare and therefore it is necessary to conduct the research on its identification, study and systematization.

The novelty of the study is to conduct a comprehensive analysis and identify the typology of wooden buildings in the classicism style of Tomsk. In the course of the work the authors used the following methods: critical analysis of bibliographic sources, comparative architectural analysis and system-structural analysis of information, as well as creative synthesis in the formation of conclusions.

As a result of the conducted bibliographic and field studies the identified objects were divided into four main types according to their volume and spatial characteristics. It is established that the classic wooden building in Tomsk has great historical value. It is the material embodiment of constructive and technical knowledge, architectural and artistic traditions.
Models and prototypes of Voronezh construction of the first third of the 19th
Authors: Yenin A E , Guriev S N , Guriev G S
Published: June 2021

For the first time, the authors of the article publish the results of a comparative study of unique historical and architectural monuments of Voronezh built in the period of classicism, their compositional, decorative, and space-planning features, similarities and differences as compared to the architectural prototypes of Russian capitals, and their correspondence to the “model” projects of the late 18th and early 19th centuries. The results of the architectural-decorative, structural-compositional, morphological, and factor analysis, based on the most outstanding examples of Voronezh architecture of the first half of the 19th century, can enhance the understanding and deepen the scientific knowledge on the origins of the development of the classicist tradition in the provincial architecture of Voronezh. A correlation was found between Moscow buildings of the school of M. F. Kazakov and his contemporaries, as models and prototypes, and the classical architectural monuments of Voronezh. The prototypes of “model” projects designed by the architect V. P. Stasov, which completely correspond to the Voronezh buildings of the first half of the 19th century, were established. The determination of architectural analogues and models of classical Russian architecture, which have become the prototypes of provincial Voronezh architecture, based on the regulation and state control of the construction will significantly expand the attribution of historical and architectural monuments of classicism in Voronezh as an integral part of all-Russian architecture.
Matrix calculation of the period of non-rhythmic flow balanced at a slow rate
Authors: Zobkova N V , Timokhin D K
Published: June 2021

When designing the organization of construction by the flow method, the presence of unbalanced non-rhythmic flows is inevitable. The article deals with the issues of balancing non-rhythmic construction flows at a slow pace on the basis of a matrix algorithm for calculating the parameters of the construction flow. Methods of balancing construction flows are described. The matrix calculation of the parameters of the non-rhythmic flow balanced at a slow rate showed the properties of potential and paradoxical works. From the calculation results it is seen that increasing the rhythm accelerated processes on the allowed organizational downtime between jobs on the hook improves the quality of the construction of the flow, namely increasing the density ratio of the graph, reducing the total amount of organizational downtime, improve utilization of the scope of work. The total duration of the construction flow remains the same when using the properties of potential works and decreases when using paradoxical works.
Rational method for calculating statically indeterminate symmetric systems
Authors: Shagisultanova J N , Panfilov A V
Published: June 2021

Nowadays, the process of calculating structures is more and more entrusted to automatic calculation systems or artificial intelligence. This increases the accuracy and reliability of the calculations, but does not contribute to the understanding of the real work of the structures by the design engineer or architect. The main difficulty in carrying out such calculations is associated with the multifactorial nature of the solutions, and, as a rule, a significant number of unknowns and variables included in the calculation. The calculation is always carried out with the introduction of a certain degree of accuracy, which, in combination with a large number of variables, leads to the appearance of the effect of a cumulative decrease in the degree of reliability of the calculations carried out and the accumulation of statistical error. In turn, this can develop into a critical state. The technique presented in the article allows one to reduce the number of variables when solving problems of calculating statically indeterminate structures without changing the final result of the calculation.
Construction project management technology based on the theory of system stability
Authors: Tsopa N V , Malakhova V V , Fedorkina M S
Published: June 2021

Abstract The paper substantiates possibility and necessity of applying the system stability theory to the management of a construction project. Stability theories of automatic control systems are considered. Sustainability of construction projects is considered based on the sustainability theory of organizational systems. The indicators that characterize the degree of stability of the construction project are determined.

The main indicators of project sustainability are Net Present Income, project payback period, internal rate of return and project profitability. A mechanism for calculating these indicators before and after the application of the project management technology is presented. Approbation of the proposed project management technology based on sustainability indicators was carried out on the example of the construction of the “Villa Rose” cottage village. In the process of management, risks were identified at the stages of project implementation with the help of independent experts. The integral indicator of the project risk has been determined and the project risk management strategies have been selected.
Application of the Townsend-George wake theory to field measurements of wind turbine wakes
Authors: Neunaber Ingrid , Obligado Martin , Peinke Joachim , Aubrun Sandrine
Published: June 2021

As wind turbines are usually clustered in wind farms, knowledge of the evolution of the wind turbine wakes is important because downstream turbines will be exposed to them, causing higher loads and maintenance times. For that reason, wind turbine wakes have been studied intensively and different engineering wake models were derived. However, none of them is constructed from a few basic and robust assumptions, while such a formalism already exists for the axisymmetric turbulent wake. Therefore, we will apply these models to data obtained in a wind farm using a scanning LiDAR. The wakes of two wind turbines are analyzed in four different wind directions chosen so that their wakes will have different degrees of interaction. The axisymmetric wake models are found to perform better than the Jensen wake model, and the main source of improvement is shown to be the presence of a virtual origin. Indeed, a virtual origin is shown to also improve the Jensen wake model significantly. Overall, our results indicate that a view from classical axisymmetric wake theory can help to improve the understanding of the evolution of wind turbine wakes in the atmospheric boundary layer.
Evaluation of the Effects of Actuator Line Force Smearing on Wind Turbines Near-Wake Development
Authors: Cormier Marion , Weihing Pascal , Lutz Thorsten
Published: June 2021

In the present study, the effects of the actuator line force smearing on the predicted near-wake development of a model wind turbine are evaluated. To exclude the uncertainties related to the blade loads computation, the loads of a corresponding blade-resolving simulation are imposed. Three force projection functions are applied, which all radially scale with the local chord length: an isotropic Gauss force distribution, an anisotropic Gauss distribution with distinct projection widths in the chord and thickness directions, and a Gauss-Gumbel projection function which creates an airfoil-like force distribution in the chord direction. Comparisons with corresponding blade-resolving simulations and experimental results show a good agreement of the tip vortex core size, position and circulation. Comparison of the mid-wake instantaneous streamwise velocity with blade-resolving simulations shows a thinner vortex sheet and stronger effects of the trailed vortices in the actuator line simulation. Although the bound vortex shape scales with the projection function, no significant difference was observed in the resulting tip vortices and near-wake flow field between the three projection functions used. It is attributed to the similar projection width in the tip vortex region for all cases considered. With the chosen grid refinement in the tip vortex area and a smearing width that scales with the chord length, tip vortices that compare with high-resolution experiments and high-fidelity blade-resolving simulation could be generated with the actuator line approach.
Verification of induction zone models for wind farm annual energy production estimation
Authors: Forsting A Meyer , Rathmann OS , Laan MP van der , Troldborg N , Gribben B , Hawkes G , Branlard E
Published: June 2021

Fast engineering wake models are the backbone of wind farm annual energy production (AEP) estimators, whereas the addition of induction zone models in existing tools is a more recent response to rising concerns over wind farm blockage associated losses. Here, “blockage” describes the combined induction fields of all wind turbines inside a farm. Unlike the term might suggest, blockage not only reduces flow speeds, but also increases them; for instance along the outer edges of wind farms. Evaluating the overall impact on AEP of these gains and losses necessitates accurate wind farm induction models. Whilst engineering wake models are tuned to predict wind farm performance, existing induction zone models are all derived for accurately predicting the near field induction not the far field value—important for wind farm simulations. This paper presents the induction models implemented in the wind farm simulation tool PyWake, as well as results from novel analytical models and compares their far field predictions to RANS-AD simulations of different turbines. We demonstrate that when including blockage in AEP simulations, the downstream speed-ups need to be included to avoid an unrealistic bias toward AEP loss and that wake expansion significantly impacts induction at rated thrust levels.
Greenhouse gas emissions from food systems: building the evidence base
Authors: Tubiello Francesco N , Rosenzweig Cynthia , Conchedda Giulia , Karl Kevin , Gütschow Johannes , Xueyao Pan , Obli-Laryea Griffiths , Wanner Nathan , Qiu Sally Yue , Barros Julio De , Flammini Alessandro , Mencos-Contreras Erik , Souza Leonardo , Quadrelli Roberta , Heiðarsdóttir Hörn Halldórudóttir , Benoit Philippe , Hayek Matthew , Sandalow David
Published: June 2021

New estimates of greenhouse gas (GHG) emissions from the food system were developed at the country level, for the period 1990–2018, integrating data from crop and livestock production, on-farm energy use, land use and land use change, domestic food transport and food waste disposal. With these new country-level components in place, and by adding global and regional estimates of energy use in food supply chains, we estimate that total GHG emissions from the food system were about 16 CO2eq yr−1 in 2018, or one-third of the global anthropogenic total. Three quarters of these emissions, 13 Gt CO2eq yr−1, were generated either within the farm gate or in pre- and post-production activities, such as manufacturing, transport, processing, and waste disposal. The remainder was generated through land use change at the conversion boundaries of natural ecosystems to agricultural land. Results further indicate that pre- and post-production emissions were proportionally more important in developed than in developing countries, and that during 1990–2018, land use change emissions decreased while pre- and post-production emissions increased. We also report results on a per capita basis, showing world total food systems per capita emissions decreasing during 1990–2018 from 2.9 to 2.2 t CO2eq cap−1, with per capita emissions in developed countries about twice those in developing countries in 2018. Our findings also highlight that conventional IPCC categories, used by countries to report emissions in the National GHG inventory, systematically underestimate the contribution of the food system to total anthropogenic emissions. We provide a comparative mapping of food system categories and activities in order to better quantify food-related emissions in national reporting and identify mitigation opportunities across the entire food system.
Livable of the past-rural affordable settlement in current urban environment
Authors: Samodra F X T B , Irvansyah I
Published: June 2021

In Indonesia, traditional houses were designed according to the rural environment, which had the maximum natural ventilation and minimum building heat gain. Currently, the occupant population and building growth are significant factors affecting energy efficiency. Moreover, technological advances demand electric applications, which results in higher internal heat gain and cooling loads, particularly in the lowland tropical regions, which has a higher temperature than upland areas. On the other hand, the change in an environment still controls the cooling loads with the minimum potency of wind speed to restore the thermal comfort as a new building adaptation model. This study aimed to evaluate the thermal condition and the energy performance of traditional tropical houses using the Ecotect Analysis program for cooling load analysis based on the field study data. The results showed that the highest cooling loads were the result of sol-air and internal heat gain elements. The building envelope’s conduction factor significantly affects indoor temperature fluctuation indicated by a similar trend in heat gains and heat losses.
A literature review on the durability of ferrous and non-ferrous geopolymer concrete for sustainable developments
Authors: Permatasari I W , Oksri-Nelfia L , Siregar P H R , Yuwono B E
Published: June 2021

The usage of cement in concrete caused the release of CO2 emission which can cause global warming. Moreover, cement as main ingredient can result in depletion or even loss of limestone which serves as a water supplier for farmers. Geopolymer concrete does not use cement but industrial byproducts containing aluminate (Al) and silicate (Si) such as slag, fly ash, and metakaolin. Moreover, these materials are from industrial solid waste (slag) so that it becomes an added value for construction. This paper discusses the durability of geopolymer concrete with material derived from the ferrous and non-ferrous melting processes because of the lack of study in durability. In construction, the concrete durability is the main thing that must be considered. Durability analysis aims to make the concrete last a long time, especially in aggressive environments. It refers to high concentrated CO2 level in an urban area or marine environment that has sodium chloride and sodium sulfate levels. Increasing of non-ferrous content can lower total pore volume in geopolymer binder while the macropores are formed. High-calcium ferrous content addition has pore-enhancing effect. The lower the porosity, the lower the permeability in the concrete. It lowers the water content and compounds such as chloride absorbed in concrete. Chloride and CO2 diffusion can cause carbonation in concrete leading to corrosion in steel reinforcement and shrinkage. This literature study aims to enhance knowledge in concrete durability so building construction can last as the planned period. Hence, the utilization of natural resources as construction material can be more efficient.
Solar energy as natural resource utilization in urban areas: Solar energy efficiency literature review
Authors: Ummah H F , Setiati R , Dadi Y B V , Ariq M N , Malinda M T
Published: June 2021

Solar power plant is a power generator that utilizes solar cells to transform solar radiation into electrical energy. Solar cells are a direct energy technology. Electrical energy can be produced without the assistance of moving fluids such as vapour or gas. If it is compared with wind, water and biomasses powers, solar cells utilization tend to be much easier and simpler. The aim of this research is to evaluate urban areas potentials to utilize solar cells as solar power plant. The energy of the sun as a stable electricity source would never be damaged and environmental friendly. A solar power plant system is divided into several sections. Solar cells will transform solar energy into electricity. The electricity produced by solar panels will be stored in an accumulator through a charger controller. This charger controller will act as voltage and current regulator in the accumulator. Rooftop solar power plant utilization has improved as much as 170%. At this moment, there are numerous buildings and housings in urban areas that have already installed rooftop solar panels as electricity generator. Jakarta and Surabaya are two major cities that have already implement rooftop solar power plant on top of office buildings, universities, and housings. Rooftop solar power plant is an environmental friendly and a potential electricity generator to be implemented.
Study of motion comfort on the roof slope to optimize urban farming
Authors: Widhita J , Winansih E , Wahjutami E L
Published: June 2021

One of the efforts of urban food problems can be resolved by urban farming activities with green roofs application on sloping roofs in crowded settlement. The study aims to know the body movements comfort in the planting activity on the green roof for productive plants with a case study of sloping roofs using simulation. This study is an experimental research by using simulation methods. The experimental variables in this study were height, sex and the range of the planting process. The simulation research uses a growing media module which is placed at an angle of 15 degrees and 30 degrees. The obtained data tested T test method to find the differences level of male and female respondents data. After the T test, a simple regression test was performed to determine the effect of the respondent’s height on the range of the planting process. T test results show that male and female data in each module with slopes 15 degrees and 30 degrees have different results. ANOVA test regression analysis results showed a significant influence between height and distance of planting range in male respondents was 47.5 percent in the 15 degrees module and 49.02 percent in the 30 degrees module, while in the female respondents had a 31.64 percent result at modules 15 degrees and 54.44 percent in the 30 degrees module. The results of both data (male and female) showed that the slope of 30 degrees is more comfortable than the slope of 15 degrees.
Rule of thumb for the calculation of overall transfer thermal value in Bandung
Authors: Kusumawati L , Setyowati E , Purnomo A B
Published: June 2021

The rule of thumb for heat transfer in building envelopes is made to make it easier to calculate heat transfer using the OTTV formula from SNI. Using this formula, it often makes it difficult for architects to quickly estimate the heat transfer value of a building. The OTTV formula variable issued by SNI is not an architectural design variable. Only one variable that is in accordance with the field of architecture is the window to wall ratio (WWR). The use of the OTTV formula is very dependent on the location of the building and solar radiation. So to overcome this difficulty, the researcher tries to offer a rule of thumb formula for calculating heat transfer. To get the OTTV formula by rule of thumb by means of design variable regression. With the rule of thumb formula for calculating OTTV, it is hoped that it can make it easier for architects to consider designs that are adapted to local conditions.
Typology of foundation in Banjar traditional architecture: The solution for house foundation in swamp land in Banjarmasin
Authors: Huzairin M D , Oktaviana A
Published: June 2021

In recent years in Banjarmasin there have been a number of cases of failures in house building structures, all of which have occurred in the foundation. This problem must be immediately resolved, through identifying the causes of failure to find the structure and construction model of the ideal foundation for swamp land. One of foundation structure and construction that has proven its resistance to various loads in a period of 75 years to more than 200 years on swampy land is the foundation of traditional Banjar houses. The solution to this problem will begin with the identification of the typology of the foundations of traditional houses in Banjarmasin as a swampy area with a depth of hard soil around 40 meters. The typology that is formulated is based on several variables, namely: the elements of the foundation along with the dimensions and type of material, the connection system between the foundation elements, the maximum bearing capacity of the foundation, and the position of the foundation against the tidal of ground water. The research method is carried out through detailed measurement and photographed of the research object which is also drawn to the standard of detailed engineering design (2 dimensions). The graphic data of the research object is used as the basis for formulating the typology of the Banjar traditional house foundation with variable construction elements, connection systems, bearing capacity, and position on the tidal of ground water. The variables are arranged by matrix and analyzed to get typology grouping. From the results of the study, there are 6 types of foundation system in which all types foundation consist of laid down trunks which distributes the load to the ground through columns that bearing the entire load from above. The trunk foundation is below the lowest tidal ground water line and has a greater bearing capacity than the load it delivers.