Envelope Structure Research Articles

Phenomenon of courtyards being roofed and its significance for building energy efficiency

Courtyard building is an important type of vernacular architecture, widely distributed in different climate zones around the world. Traditionally, courtyards are characterized by opening to the sky, providing buffer spaces for ventilation and light for the surrounding buildings. However, in Hebei, China, local buildings are showing an evolution trend characterized by the courtyards being roofed (CBR). This spontaneous evolution presents the diversity of CBR technologies (CBRTs), including light-transmitting CBRTs (T-CBRTs) and non-light-transmitting CBRTs (NT-CBRTs). Based on field measurements and simulation technology, the improvement effect of CBR on building energy efficiency (EE) is analyzed, and the EE of different CBRTs is compared. The results show that, T-CBRT and NT-CBRT can reduce the annual total energy consumption of open courtyards by 19.97% and 15.41% respectively without upgrading the original envelope structure. The analysis of the impact mechanism shows that CBRT increases the temperature of the courtyard and the room by improving the solar energy collection efficiency and expanding the heat storage space, which effectively reduces the heat leakage caused by the envelope and ventilation, and shortens the heating time. The light transmittance of the roof material is the most critical parameter affecting the EE of T-CBRT, and the roof height largely determines the performance of NT-CBRT. Multi-layer glass or concrete panels are not the best choice for CBRT roofing materials, and plastic films or polycarbonate sheets with high light transmittance and anti-aging are recommended. CBR is considered as a promising development direction because it can reduce the economic burden of energy consumption for local farmers by improving the EE of buildings.

Sublimation of refractory minerals in the gas envelopes of accreting rocky planets

Protoplanets growing within the protoplanetary disk by pebble accretion acquire hydrostatic gas envelopes. Due to accretion heating, the temperature in these envelopes can become high enough to sublimate refractory minerals which are the major components of the accreted pebbles. Here we study the sublimation of different mineral species and determine whether sublimation plays a role during the growth by pebble accretion. For each snapshot in the growth process, we calculate the envelope structure and the sublimation temperature of a set of mineral species representing different levels of volatility. Sublimation lines are determined using an equilibrium scheme for the chemical reactions responsible for destruction and formation of the relevant minerals. We find that the envelope of the growing planet reaches temperatures high enough to sublimate all considered mineral species when M ≳ 0.4 M⊕. The sublimation lines are located within the gravitationally bound envelope of the planet. We make a detailed analysis of the sublimation of FeS at around 720 K, beyond which the mineral is attacked by H2 to form gaseous H2S and solid Fe. We calculate the sulfur concentration in the planet under the assumption that all sulfur released as H2S is lost from the planet by diffusion back to the protoplanetary disk. Our calculated values are in good agreement with the slightly depleted sulfur abundance of Mars, while the model over predicts the extensive sulfur depletion of Earth by a factor of approximately 2. We show that a collision with a sulfur-rich body akin to Mars in the moon-forming giant impact lifts the Earth’s sulfur abundance to approximately 10% of the solar value for all impactor masses above 0.05 Earth masses.

ALMA Reveals Hidden Morphologies in the Molecular Envelope of VY Canis Majoris

The J = 2 → 1 transition of CO near 230 GHz and the J = 3 → 2 line of HCN at 265 GHz have been imaged in the envelope of the red hypergiant star, VY Canis Majoris (VY CMa), using the Atacama Large Millimeter Array (ALMA) with angular resolutions 0.″2–1.″5; single-dish data were added to provide sensitivity up to 30″. These images reveal a far more complex envelope, with previously unseen outflows extending 4″–9″ from the star. These new structures include an arc-like outflow with an angular separation of ∼9″ northeast from the stellar position (“NE Arc”), twin fingerlike features approximately 4″ to the north/northeast (“NE Extension”), and a roughly spherical region observed ∼7″ E of the star (“E Bubble”). The NE Arc appears to be decelerating from base (V LSR ∼ 7 km s−1) to tip (V LSR ∼ 18 km s−1), while the NE Extension is blueshifted with V LSR ∼ −7 km s−1. Among the new features, HCN is only detected in the NE Arc. In addition, known structures Arc 1, Arc 2, and NW Arc, as well as other features closer to the star, are closely replicated in CO, suggesting that the gas and dust are well mixed. The CO spectra are consistent with the kinematic picture of VY CMa derived from HST data. Arc 2, however, has added complexity. Preliminary results from CO suggest 12C/13C ∼ 22–38 across the envelope. The additional presence of at least three major episodic mass ejection events significantly broadens the current perspective of the envelope structure and mass-loss history of VY CMa.

Construction of Building an Energy Saving Optimization Model Based on Genetic Algorithm

The building envelope structure is the cause of a major part of energy consumption, with exterior walls and windows being the main energy-consuming components. Traditional building energy conservation measures often overlook the demand for human comfort, especially in areas characterized by hot summers and warm winters. For this paper, the authors concentrated on indoor comfort, with a focus on optimizing the heat transfer coefficient of windows and exterior walls using a genetic algorithm. They used a genetic algorithm to explore the performance optimization of exterior walls and windows in the enclosure structure. To aid this effort, they constructed a building energy-saving optimization model. In addition, they created an optimization model in an attempt to reduce building energy consumption. They took the heat transfer coefficients of the outer window and the outer wall as the optimization parameters of the established model, and they compiled the optimization program using MATLAB. The experimental results showed that the heat transfer coefficients of exterior walls and windows in cold regions are 0.4459 and 2.7875, respectively, while the heat transfer coefficients in warm winter and hot summer regions are 0.66, 1.98, 1.026, and 1.59. The conducted work provides a reference for the optimization design of the heat transfer coefficient of external walls and windows as a measure to enhance building energy efficiency.

Building Thermal and Energy Performance of Subtropical Terraced Houses under Future Climate Uncertainty

Due to global temperature increases, terraced house (TH) residents face a threat to their health due to poor indoor thermal environments. As buildings are constructed by low-income residents without professional guidance, this study aims to investigate the indoor thermal comfort and energy resilience of THs under the future climate and determine the optimal passive design strategies for construction and retrofitting. By exploring the effects of building envelope structures, adjusting the window-to-wall ratio (WWR) and designing shading devices, EnergyPlus version 22.0 was used to optimize the thermal environment and cooling load of THs throughout their life cycle under future climate uncertainties. Unimproved THs will experience overheating for nearly 90% of the hours in a year and the cooling load will exceed 60,000 kWh by 2100 under the Representative Concentration Pathways (RCP) 8.5 scenario. In contrast, optimization and improvements resulted in a 17.3% reduction in indoor cooling load by increasing shading devices and the WWR, and using building envelope structures with moderate thermal insulation. This study can guide TH design and renovation, significantly reducing indoor cooling load and enabling residents to better use active cooling to combat future overheating environments.

Assessment of auditory perception abilities using temporal envelope and fine structure processing in children with self-limited epilepsy with centrotemporal spikes

ObjectivesChildren with self-limited epilepsy with centrotemporal spikes (SeLECTS) exhibit difficulty processing spoken messages without hearing loss. The temporal envelope and fine structure processing abilities are the fundamental aspects of the normal listening process. There is limited literature on the temporal envelope and fine structure processing in children with SeLECTS. We evaluated the temporal envelope and fine structure processing in children with SeLECTS. DesignThe study included 35 children with SeLECTS and 50 typically developing children (TDC). The temporal envelope processing was measured using the temporal modulation transfer function (TMTF) and temporal fine structure using the temporal fine structure low-frequency (TFS LF) test. The TMTF was measured for the modulation rates 4, 8, 16, 32, 64 and 128 Hz. The TFS LF was done for 250, 500 and 750 Hz. ResultsThe difference in modulation detection thresholds at 4 Hz was not found to be significant, whereas there was a significant difference in modulation detection thresholds observed for all the other modulation frequencies (p < 0.05) between the children with SeLECTS and TDC. The thresholds at 250, 500 and 750 Hz were higher (poorer) for children with SeLECTS than the TDC and was significant (p < 0.05). ConclusionsThe TMTF and TFS LF tests were of practical use in evaluating temporal envelope and fine structure processing abilities in children with SeLECTS. The results suggest that children with SeLECTS have a poor temporal envelope and fine structure processing compared to the TDC.

Research on indoor dynamic temperature based on circulating water heating

During the heating season, cities in northeast China primarily emphasize the implementation of large-scale CHP central heating systems. However, the heat-electricity constraints associated with these heating units hinder the integration of clean energy sources such as wind power, photovoltaic, and other renewable energies. Despite efforts to reduce carbon emissions and address concerns related to urban haze formation, energy conservation, and emission reduction, coal remains the predominant energy source for heating.In light of these challenges, this paper aims to investigate the heat transfer characteristics of buildings during the heating season. It also examines the feasibility of implementing heating regulations and provides a theoretical foundation for establishing a regional heat model that incorporates low-carbon energy islands. The proposed model combines wind power, photovoltaic power generation, and other renewable energy sources supplemented with coal power.By employing the concentrated heat capacity method, this study develops a mathematical model to simulate the dynamic thermal process involved in heating buildings. The model encompasses various components, including the dynamic heat transfer model of the building’s envelope structure, which considers its heat storage characteristics, as well as the radiator model and the indoor air heat balance equation. Furthermore, the model comprehensively accounts for the influence of different indoor and outdoor disturbances on the heat transfer process, including the effects of solar radiation.To validate the model, a simulation program is implemented using Matlab. This program is capable of hourly calculations to determine the indoor temperature. By comparing the simulated temperature values with the measured ones, the rationality and accuracy of the model are verified.

Thermal performance of double-layer pipe-embedded envelope with low-grade energy for heating

Heat dissipation through a non-transparent envelope contributes significantly to the heating load during winter. The traditional single-layer pipe-embedded external wall (SPEW) can utilize low-grade energy to reduce the heat transfer through the envelope but can hardly be used for direct room heating. This study proposes a double-layer pipe-embedded external wall (DPEW) to utilize low-temperature hot water to reduce heat loss and provide indoor heating in winter. A numerical model of DPEW is developed to analyze its heat transfer performance. After experimental validations, the model is used to investigate the heat transfer performance of DPEW with different water temperatures, ambient temperatures, and envelope structures. The results show that (1) for the outer pipes of DPEW, water with a temperature lower than the room temperature (e.g., 12 °C) can be employed to reduce heat loss through the wall; for inner pipes of DPEW, water with a temperature slightly higher than the room temperature (e.g., 22 °C) can be employed for direct room heating; (2) the insulation layer thickness of the DPEW can be reduced to be significantly smaller than that of a conventional wall; an insulation layer between the two layers of embedded pipes is necessary to reduce heat transfer between water pipes; (3) the effect of water temperature on the heating capacity of DPEW is more significant than that of ambient temperature; increasing the pipe diameter and decreasing the pipe spacing can improve the heating capacity of DPEW.

Light Curves of Type IIP Supernovae from Neutrino-driven Explosions of Red Supergiants Obtained by a Semianalytic Approach

Type IIP supernovae (SNe IIP) mark the explosive death of red supergiants (RSGs), evolved massive stars with an extended hydrogen envelope. They are the most common supernova type and allow for the benchmarking of supernova explosion models by statistical comparison to observed population properties rather than by comparing individual models and events. We construct a large synthetic set of SNe IIP light curves (LCs) using the radiation hydrodynamics code SNEC and explosion energies and nickel masses obtained from an efficient semianalytic model for two different sets of stellar progenitor models. By direct comparison, we demonstrate that the semianalytic model yields very similar predictions as alternative phenomenological explosion models based on 1D simulations. We find systematic differences of a factor of ∼2 in plateau luminosities between the two progenitor sets due to different stellar radii, which highlights the importance of the RSG envelope structure as a major uncertainty in interpreting the LCs of SNe IIP. A comparison to a volume-limited sample of observed SNe IIP shows decent agreement in plateau luminosity, plateau duration, and nickel mass for at least one of the synthetic LC sets. The models, however, do not produce sufficient events with very small nickel mass M Ni < 0.01 M ⊙ and predict an anticorrelation between plateau luminosity and plateau duration that is not present in the observed sample, a result that warrants further study. Our results suggest that a better understanding of RSG stellar structure is no less important for reliably explaining the LCs of SNe IIP than the explosion physics.

Prolonged hypothermic storage of oocytes of the European common frog Rana temporaria in a gas mixture of oxygen and carbon monoxide.

The maximum hypothermic storage time of amphibian oocytes is several hours, which is due to the peculiarities of the structure of the cell envelope. The authors of this paper have already demonstrated the possibility of increasing the storage period of unfertilized oocytes of the common frog (Rana temporaria) up to 5-7 days. The aim of the current study was to determine the possibility of using a 6.5 atm gaseous mixture of carbon monoxide and oxygen, for prolonged hypothermic preservation of unfertilized oocytes for 4 to 12 days. After four days, oocytes stored under CO+O2 conditions exhibited fertilization and hatching rates that were 1.6 and 2.2-fold higher than control, respectively. While no oocytes in the control group survived to day twelve, oocytes held under CO +O2 gas exhibited a 39±14% (38 out of 99 oocytes in total) fertilization rate, however only 1±2% (1/99) of those hatched. This approach is promising for the storage of genetic material from female amphibians, particularly in respect to managing and restoring endangered species, but may also be applicable to oocytes of other classes of vertebrates.

Direct interaction between fd phage pilot protein pIII and the TolQ–TolR proton-dependent motor provides new insights into the import of filamentous phages

Filamentous phages are one of the simplest examples of viruses with a protein capsid that protects a circular single-stranded DNA genome. The infection is very specific, nonlytic, and can strongly affect the physiology or provide new pathogenic factors to its bacterial host. The infection process is proposed to rely on a pore-forming mechanism similar to that of certain nonenveloped eukaryotic viruses. The Ff coliphages (including M13, fd, and f1) have been intensively studied and were used to establish the sequence of events taking place for efficient crossing of the host envelope structure. However, the mechanism involved in the penetration of the cell inner membrane is not well understood. Here, we identify new host players involved in the phage translocation mechanism. Interaction studies by a combination of invivo biochemical methods demonstrate that the adhesion protein pIII located at the tip of the phage binds to TolQ and TolR, two proteins that form a conserved proton-dependent molecular motor in the inner membrane of the host cell. Moreover, invivo cysteine cross-linking studies reveal that the interactions between the pIII and TolQ or TolR occur between their transmembrane helix domains and may be responding to the proton motive force status of the cell. These results allow us to propose a model for the late stage of filamentous phage translocation mediated by multiple interactions with each individual component of the host TolQRA complex.

Thermal assessment of vertical enclosing structures taking into account thermal effects

Introduction. The hot and unfavorable climate, affecting both the person and the building as a whole, increases more and more every year. This trend of temperature increase is noted not only in the cities of the southern region of the Russian Federation, but also in the world, which is caused by the problem of global warming. Identification of the values of thermal effects on buildings and structures in the aspect of increasing the energy efficiency of buildings is a priority.&#x0D; &#x0D; Materials and methods. The calculation method is presented in the form of a formulaic mathematical model and a numerical method using a software package. The object of the study is a residential building with a frame system construction and frame scheme. Enclosing structures are made of aerated concrete blocks with the device of wet and ventilated facade.&#x0D; &#x0D; Results. Qualitative and quantitative results of the study are presented in the form of graphical calculations. The results of the energy audit of enclosing structures under conditions of loading by thermal influences are obtained. Temperature dependences between the surface outside of the envelope and inside are established. Critical temperatures on the surface of enclosing structures outside the room at which unfavorable conditions are observed on the surface inside are determined. Problems in the field of determining the threat of external thermal factors on the enclosing structures taking into account their vulnerable parts in the application of two methods of thermal loads control in the conditions of unsteady heat transfer have been solved.&#x0D; &#x0D; Conclusions. A calculation procedure using the finite element method by means of a software package under conditions of thermal effects on the enclosing structures has been developed, which allows to predict the temperature shifts on the wall surface inside the room. A comparative analysis of the advantages and disadvantages of the recommended structures used for building envelope design is carried out. The conditions for energy efficiency improvement in the application of two methods of thermal load control under unsteady heat transfer conditions have been identified, and recommendations for improving the energy efficiency of building envelope structures have been developed.

Research on low‐carbon evaluation of clean energy use in rural residential buildings based on Analytic Hierarchy Process method

AbstractAs an important part of the construction industry, rural residential buildings are characterized by low energy utilization, unreasonable structure, and low consumption level, so it is particularly important to study the low carbon transformation and evaluation system. In this study, the coefficient of variation method was used to identify the important factors affecting the low‐carbon transformation of rural residential buildings, and the evaluation system of low‐carbonization of rural residential buildings was determined by Analytic Hierarchy Process (AHP), and the system was used in a rural residential building low‐carbonization evaluation study. The results show that “Energy utilization,” “Envelope structure,” and “Economic factors” have obvious influence on the low carbonization of buildings, with the weights of 36.4%, 24.5%, and 19.5%, respectively. Among the secondary indicators, the top four weightings are “clean energy utilization rate” (0.152), “external wall insulation system” (0.090), “window performance” (0.088), and “electricity consumption” (0.084), which are the most critical factors influencing the low carbonization level of clean energy utilization in rural residential buildings. Finally, based on the constructed low‐carbonization evaluation system, we propose targeted solution strategies to provide a theoretical basis for establishing an effective assessment system for the low‐carbonization of clean energy in rural residential buildings.

Comparative analysis of residential building envelopes newly implementing the building insulation code in Damascus

The selection of envelope construction technique has the highest impact on sustaining indoor thermal comfort while reducing energy consumed for heating and cooling. Numerous insulation codes are implemented worldwide to improve building envelope modification. Each country has set envelope transmittances criteria, materials, techniques and simulation tools differently based on its climate zones and construction sector adaptability. The housing sector in Syria is the focus of energy conservation being responsible of half of the energy consumption in the country. Syrian post-conflict residential buildings are challenged by the new implementation of Building Insulation Code. This code has opted for a “fabric first” dwellings design approach with mandatory U-value standards. Hence, like many energy-related regulations in Syria it has been dropped because the construction sector has not been able to cope with them, forced by speculators to keep costs low. Another reason is that building thermal performance modeling has not been used to comply with the new insulation code in Syria. The research aims to examine the potential relevance of the Insulation Code in informing post-war social housing envelope structures in Damascus. It evaluates compliant building envelope structures compared to conventional building in terms of transmittance properties, simulated thermal loads (IESVE) and cost–energy trade-off. The research findings reveal an improvement in U-values of 78.5%, 31.5%, 92.7% and 90.2% achieved in compliant cases 1, 3, 4 and 5, respectively, compared to conventional case-2. The simulation demonstrated best improvement in total heating loads up to 85% achieved in case-4. Hence, the improved U-value lead to improvement in winter heating loads but overheating in summertime. The simulation was found useful but not enough to optimize envelope performance through interdisciplinary decision that contributes positively to Syrian post-war circumstances. The cost analysis found an increase in wall initial construction costs, amounting to 36.4%, 27.3%, 54.6% and 45.5% in cases 1, 3, 4 and 5 with long payback periods. These findings spark a new agenda for Insulation Code improvement. The proposed simplified criteria offer practitioners more understanding to customize their own list of envelope structure parameters based on the climatic zone resulting in a shift in envelope selection from input to a more output oriented.

Under the background of green architecture, the aesthetic elements of Henan's traditional ancient architecture and modern architecture based on BIM technology

With the introduction of the "double carbon" target in China, green building has gradually become a trend in the development of China's construction industry. The combination of traditional architecture and modern architecture based on the concept of green architecture has become a new pursuit for architects. Based on this, this study integrates the aesthetic elements of traditional ancient architecture in Henan with modern architecture in the context of green building design. This paper first introduces the basic theory of the green building evaluation system and compares and analyzes the green building evaluation system at home and abroad. Secondly, the feasibility of using BIM technology in green buildings is demonstrated in terms of usage cost, and the application of BIM technology in green building evaluation is introduced with the modernization design of an ancient building in Henan. Finally, we calculated and analyzed the key indicators of the energy performance of a building in Henan. According to the results, the studied case building has a 13% reduction in the system-integrated part-load performance coefficient and a 6.6% reduction in the integrated heat gain coefficient of the envelope structure.

Structure and its transformation of elliptical nege-like virus Tanay virus.

Negeviruses that infect insects are recently identified virus species that are phylogenetically related to several plant viruses. They exhibit a unique virion structure, an elliptical core with a short projection. Negeviruses encode two structural proteins, a glycoprotein that forms a short projection, and an envelope protein that forms an elliptical core. The glycoprotein has been reported only in the negeviruses' genes, and not in phylogenetically related plant viruses' genes. In this report, we first describe the three-dimensional electron cryo-microscopy (cryo-EM) structure of Tanay virus (TANAV), one of the nege-like viruses. TANAV particle demonstrates a periodical envelope structure consisting of three layers surrounding the centred viral RNA. The elliptical core dynamically changes its shape under acidic and even low detergent conditions to form bullet-like or tubular shapes. The further cryo-EM studies on these transformed TANAV particles reveal their overall structural rearrangement. These findings suggest putative geometries of TANAV and its transformation in the life cycle, and the potential importance of the short projection for enabling cell entry to the insect hosts.

New Strategies to Kill Metabolically-Dormant Cells Directly Bypassing the Need for Active Cellular Processes.

Antibiotic therapy failure is often caused by the presence of persister cells, which are metabolically-dormant bacteria capable of surviving exposure to antimicrobials. Under favorable conditions, persisters can resume growth leading to recurrent infections. Moreover, several studies have indicated that persisters may promote the evolution of antimicrobial resistance and facilitate the selection of specific resistant mutants; therefore, in light of the increasing numbers of multidrug-resistant infections worldwide, developing efficient strategies against dormant cells is of paramount importance. In this review, we present and discuss the efficacy of various agents whose antimicrobial activity is independent of the metabolic status of the bacteria as they target cell envelope structures. Since the biofilm-environment is favorable for the formation of dormant subpopulations, anti-persister strategies should also include agents that destroy the biofilm matrix or inhibit biofilm development. This article reviews examples of selected cell wall hydrolases, polysaccharide depolymerases and antimicrobial peptides. Their combination with standard antibiotics seems to be the most promising approach in combating persistent infections.

The role of CenKR in the coordination of Rhodobacter sphaeroides cell elongation and division.

Cell elongation and division are essential aspects of the bacterial life cycle that must be coordinated for viability and replication. The impact of misregulation of these processes is not well understood as these systems are often not amenable to traditional genetic manipulation. Recently, we reported on the CenKR two-component system (TCS) in the Gram-negative bacterium Rhodobacter sphaeroides that is genetically tractable, widely conserved in α-proteobacteria, and directly regulates the expression of components crucial for cell elongation and division, including genes encoding subunit of the Tol-Pal complex. In this work, we show that overexpression of cenK results in cell filamentation and chaining. Using cryo-electron microscopy (cryo-EM) and cryo-electron tomography (cryo-ET), we generated high-resolution two-dimensional (2D) images and three-dimensional (3D) volumes of the cell envelope and division septum of wild-type cells and a cenK overexpression strain finding that these morphological changes stem from defects in outer membrane (OM) and peptidoglycan (PG) constriction. By monitoring the localization of Pal, PG biosynthesis, and the bacterial cytoskeletal proteins MreB and FtsZ, we developed a model for how increased CenKR activity leads to changes in cell elongation and division. This model predicts that increased CenKR activity decreases the mobility of Pal, delaying OM constriction, and ultimately disrupting the midcell positioning of MreB and FtsZ and interfering with the spatial regulation of PG synthesis and remodeling.IMPORTANCEBy coordinating cell elongation and division, bacteria maintain their shape, support critical envelope functions, and orchestrate division. Regulatory and assembly systems have been implicated in these processes in some well-studied Gram-negative bacteria. However, we lack information on these processes and their conservation across the bacterial phylogeny. In R. sphaeroides and other α-proteobacteria, CenKR is an essential two-component system (TCS) that regulates the expression of genes known or predicted to function in cell envelope biosynthesis, elongation, and/or division. Here, we leverage unique features of CenKR to understand how increasing its activity impacts cell elongation/division and use antibiotics to identify how modulating the activity of this TCS leads to changes in cell morphology. Our results provide new insight into how CenKR activity controls the structure and function of the bacterial envelope, the localization of cell elongation and division machinery, and cellular processes in organisms with importance in health, host-microbe interactions, and biotechnology.

ENERGY EFFICIENCY POLICY IN CIVIL ENGINEERING: OPPORTUNITIES AND PROSPECTS FOR APPLICATION

Objective. To analyze the problems of implementation of modern energy efficient systems in Ukraine. The advantages of modern technologies over outdated ones are presented. The results of the study should form the basis for the development of recommendations for improving energy efficiency in civil engineering. Problems. Today in Ukraine, solving the problem of energy saving in civil engineering remains a constant priority. Overcoming this obstacle largely determines Ukraine’s recovery from the economic crisis. According to estimates, energy consumption for heating budgetary institutions in Ukraine is 2 … 3 times higher than in the EU countries for the same needs. This is based on the obsolescence of Ukraine’s building stock from the time of intensive construction in the 1960s and 1980s. Analysis. Many countries are already successfully implementing new technologies, materials, and designs that help improve the energy efficiency of buildings. Examples include: a construction concept based on the idea of creating a building that does not require active heating and cooling – a «passive house», the use of SIP panels made from recycled materials, the use of double-glazed windows with «warm edge» technology, the creation of energy-efficient envelope structures such as the construction projects «The Edge», «ZEB Pilot House», «BedZed». Scientific novelty. Analysis of current problems of energy efficiency policy implementation in Ukraine in terms of various aspects, such as legal, economic, technical, social, etc. Cases of successful implementation of energy efficient measures and technologies in civil engineering in European countries are considered. Practical significance. The analysis of the real energy status of the country’s building stock is the basis for the development and support of energy efficiency policy. The considered cases of energy efficient technologies implementation can become an important source of information for Ukrainian construction specialists, which will significantly improve the energy efficiency of new buildings, reduce energy dependence on critical infrastructure, save money for civilians and improve the comfort of living conditions.

Research on the influence of foundation pit excavation on the lateral force and deformation of side shield tunnels based on full-scale experiments

To explore the internal force and deformation response law of the Hangzhou subway shield segment under the influence of the excavation and unloading of the side foundation pit, the self-developed “shield segment hydraulic loading system” was used to carry out full-scale loading tests on the three-ring staggered assembled segments. A preloading loading test were performed before the formal experiment to determine the loading method of the initial confining pressure. Analyzed the change mechanism of the internal force and deformation of the segment structure are influenced by factors such as the foundation pit and the tunnel clear distance. A numerical model is established based on the experimental results, and the influencing parameters that are difficult to complete in the experiment, such as the depth of the tunnel, are analyzed in detail. The research results show that the equal load maintains a balanced state of the segment to the greatest extent, and its internal force and deformation results are large, which is suitable for this experiment. After the excavation of the foundation pit, the maximum positive and negative bending moment increases, while the maximum axial force decreases. The average maximum recovery rate of tunnel section is 15.6%. Moreover, the additional internal force and deformation of the segment will increase with increasing deformation parameters of the envelope structure and decrease with increasing clear distance between the foundation pit and the tunnel. The bending moment of the segment is more sensitive to changes in the confining pressure, the convergence change can be controlled within a limited range, and the trend of the change in the internal force of the bolt shows differences. The numerical model established in this paper can better analyze the stress state of the tunnel. When the tunnel is buried deep in the slightly upper position of the excavation surface of the foundation pit, the unloading effect that is received is largest.