bluuebunny/crossref_metadata_2025 huggingface dataset:
Traditional processing increases biological activities of Dendrobium offificinale Kimura et. Migo in Southeast Yunnan, China
Authors: Zhou Di , Zhao Ying , Chen Zhilin , Yan Xiuxiang , Zhao Yanqiang , Gao Lu , Yang Lixin
Published: August 2022

The orchid Dendrobium officinale grows throughout southeast China and southeast Asian countries and is used to treat inflammation and diabetes in traditional Chinese medicine. Tie pi feng dou is a well-known traditional Chinese medicine made from the dried D. officinale stems. Processing alters the physicochemical properties of TPFD; however, it is unclear how processing affects the quality and medicinal value of this plant. Here, we analyzed and compared the chemical composition of fresh stems of D. officinale and TPFD and explored possible explanations for the enhanced medicinal efficacy of processed D. officinale stems using qualitative and quantitative methods. To identify the components of FSD and TPFD, we used ultra-high-performance liquid chromatography combined with mass spectrometry in negative and positive ion modes and interpreted the data using the Human Metabolome Database and multivariate statistical analysis. We detected 23,709 peaks and identified 2352 metabolites; 370 of these metabolites were differentially abundant between FSD and TPFD (245 more abundant in TPFD than in FSD, and 125 less abundant), including organooxygen compounds, prenol lipids, flavonoids, carboxylic acids and their derivatives, and fatty acyls. Of these, 43 chemical markers clearly distinguished between FSD and TPFD samples, as confirmed using orthogonal partial least squares discriminant analysis. A pharmacological activity analysis showed that, compared with FSD, TPFD had significantly higher levels of some metabolites with anti-inflammatory activity, consistent with its use to treat inflammation. In addition to revealing the basis of the medicinal efficacy of TPFD, this study supports the benefits of the traditional usage of D. officinale.
Ultra-broadband MIR super absorber using all silicon metasurface of triangular doped nanoprisms
Authors: Abdelsalam Mostafa , Swillam Mohamed A.
Published: August 2022

Thermo-electric generation offers to be a solid candidate for both dealing with the temperature problems of photo-voltaic cells and increasing its total output power. However, it requires an efficient broadband absorber to harness the power found in the near and mid-infrared regions. In this work, we discuss a new structure of nanoprisms that are made of doped silicon that acts as an ultra-broadband absorber in both regions. We also discuss the effect of the doping concentration. Additionally, we study the effect of a pure silicon thin film on top of the prisms. Finally, we’re able to find an optimized structure that can absorb 92.6% of the input power from 1 to $${15}\,{\upmu }$$

15

μ

m.
Reusing a prepaid health plan’s fecal immunochemical tests for microbiome associations with colorectal adenoma
Authors: Goedert James J. , Wu Zhenyi , Yonehara Cyndee H. , Frankland Timothy B. , Sinha Rashmi , Jones Gieira S. , Wan Yunhu , Ravel Jacques , Zhao Ni , Honda Stacey A.
Published: August 2022

An altered colonic microbiota probably increases colorectal adenoma (CRA) and cancer (CRC) risk, but large, unbiased fecal collections are needed to examine the relationship of gut microbiota diversity and composition to colorectal carcinogenesis. This study assessed whether fecal immunochemical tests (FITs) from CRA/CRC screening may fulfill this requirement. Using FIT, self-collected by members of Kaiser Permanente Hawaii (KPH), as well as interspersed quality control (QC) specimens, DNA was extracted and amplified to generate 16S rRNA microbiome profiles rarified at 10,000 reads. CRA/CRC were diagnosed by colonoscopy and histopathology. Covariates were from electronic KPH records. Of 921 participants’ FIT devices, 538 (58%) yielded at least 10,000 rRNA reads and 1016 species-level variants mapped to 46 genera. Of the 538 evaluable participants, 63 (11.7%) were FIT-negative per protocol, and they were considered negative for CRA/CRC. Of the 475 FIT + participants, colonoscopy and pathologic review revealed that 8 (1.7%) had CRC, 71 (14.9%) had high-risk CRA, 107 (22.5%) had low-risk CRA, and 289 (60.8%) did not have CRA/CRC. Men were 2.27-fold [95% confidence interval (CI) 1.32–3.91] more likely than women to be FIT+ . Men also had 1.96-fold (CI 1.24–3.07) higher odds of low-risk CRA, with similar trends for high-risk CRA and CRC. CRA/CRC were not associated with overweight, obesity, diabetes, or antibiotic prescriptions in this study. QC analysis across 24 batches of FIT devices revealed QC outliers in four batches. With or without exclusion of the four QC-outlier batches, as well as lenient (1000-read) rarefaction, CRA/CRC had no consistent, statistically significant associations with fecal microbiome alpha diversity, beta diversity or genera relative abundance. CRA/CRC had expected associations with male sex but not with microbiome metrics. Fecal microbiome profiling using DNA extracted from at-home collected, re-used FIT devices is feasible, albeit with substantial challenges. Using FITs for prospective microbiome studies of CRA/CRC risk should consider the impact of the current findings on statistical power and requisite sample sizes.
Sequence-dependence of Cy3 and Cy5 dyes in 3ʹ terminally-labeled single-stranded DNA
Authors: Kekić Tadija , Lietard Jory
Published: August 2022

Fluorescence is an ideal tool to see and manipulate nucleic acids, and engage in their rich and complex biophysical properties. Labeling is the preferred approach to track and quantify fluorescence with nucleic acids and cyanine dyes are emblematic in this context. The fluorescent properties of cyanine dyes are known to be sequence-dependent, with purines in the immediate vicinity increasing the fluorescence intensity of Cy3 and Cy5 dyes, and the ability of nucleobases to modulate the photophysical properties of common fluorophores may influence fluorescence measurements in critical assays such as FISH, qPCR or high-throughput sequencing. In this paper, we comprehensively map the sequence-dependence of Cy3 and Cy5 dyes in 3ʹ-fluorescently labeled single-stranded DNA by preparing the complete permutation library of the 5 consecutive nucleotides immediately adjacent to the dye, or 1024 sequences. G-rich motifs dominate the high fluorescence range, while C-rich motifs lead to significant quenching, an observation consistent with 5ʹ-labeled systems. We also uncover GCGC patterns in the extreme top range of fluorescence, a feature specific to 3ʹ-Cy3 and Cy5 oligonucleotides. This study represents the final piece in linking nucleotide identity to fluorescence changes for Cy3, Cy5 and fluorescein in all 3ʹ, 5ʹ, single-stranded and double-stranded DNA formats.
Localized efficacy of environmental RNAi in Tetranychus urticae
Authors: Bensoussan Nicolas , Milojevic Maja , Bruinsma Kristie , Dixit Sameer , Pham Sean , Singh Vinayak , Zhurov Vladimir , Grbić Miodrag , Grbić Vojislava
Published: August 2022

Environmental RNAi has been developed as a tool for reverse genetics studies and is an emerging pest control strategy. The ability of environmental RNAi to efficiently down-regulate the expression of endogenous gene targets assumes efficient uptake of dsRNA and its processing. In addition, its efficiency can be augmented by the systemic spread of RNAi signals. Environmental RNAi is now a well-established tool for the manipulation of gene expression in the chelicerate acari, including the two-spotted spider mite, Tetranychus urticae. Here, we focused on eight single and ubiquitously-expressed genes encoding proteins with essential cellular functions. Application of dsRNAs that specifically target these genes led to whole mite body phenotypes—dark or spotless. These phenotypes were associated with a significant reduction of target gene expression, ranging from 20 to 50%, when assessed at the whole mite level. Histological analysis of mites treated with orally-delivered dsRNAs was used to investigate the spatial range of the effectiveness of environmental RNAi. Although macroscopic changes led to two groups of body phenotypes, silencing of target genes was associated with the distinct cellular phenotypes. We show that regardless of the target gene tested, cells that displayed histological changes were those that are in direct contact with the dsRNA-containing gut lumen, suggesting that the greatest efficiency of the orally-delivered dsRNAs is localized to gut tissues in T. urticae.
Porphyromonas gingivalis-mediated disruption in spiral artery remodeling is associated with altered uterine NK cell populations and dysregulated IL-18 and Htra1
Authors: Tavarna Tanvi , Wolfe Bryce , Wu Xiao-jun , Reyes Leticia
Published: August 2022

Impaired spiral artery remodeling (IRSA) underpins the great obstetrical syndromes. We previously demonstrated that intrauterine infection with the periodontal pathogen, Porphyromonas gingivalis, induces IRSA in rats. Since our previous studies only examined the end stage of arterial remodeling, the aim of this study was to identify the impact of P. gingivalis infection on the earlier stages of remodeling. Gestation day (GD) 11 specimens, a transition point between trophoblast-independent remodeling and the start of extravillous trophoblast invasion, were compared to late stage GD18 tissues. P. gingivalis was found in decidual stroma of GD11 specimens that already had reduced spiral artery remodeling defined as smaller arterial lumen size, increased retention of vascular smooth muscle, and decreased invasion by extravillous trophoblasts. At GD11, P. gingivalis-induced IRSA coincided with altered uterine natural killer (uNK) cell populations, decreased placental bed expression of interleukin-18 (IL-18) with increased production of temperature requirement A1 (Htra1), a marker of oxidative stress. By GD18, placental bed IL-18 and Htra1 levels, and uNK cell numbers were equivalent in control and infected groups. However, infected GD18 placental bed specimens had decreased TNF + T cells. These results suggest disturbances in placental bed decidual stroma and uNK cells are involved in P. gingivalis-mediated IRSA.
High-efficiency modulation of broadband polarization conversion with a reconfigurable chiral metasurface
Authors: Wei Zeyong , Zhao Yunlong , Zhang Yujing , Cai Weiqi , Fan Yuancheng , Wang Zhanshan , Cheng Xinbin
Published: August 2022

A reconfigurable chiral metasurface is demonstrated with a three-layer structure of complementary split ring resonator arrays. Functional layer with tunable elements provides a platform for tunable polarization response and asymmetric transmission.
In situpolymerized synthesis of MnO nanoparticles anchored on N,S co-doped carbon as efficient cathodes for quasi-solid-state zinc ion batteries
Authors: Li Linpo , Wang Yingchao , Jiang Gang , Li Jing , Wang Mingyu , Niu Yanli , Shangguan Enbo
Published: August 2022

MnO nanoparticles confined in N,S co-doped porous C are prepared by employing acrylamide monomers as the chelating agents and carbon source. When serving as a zinc-ion battery cathode, it can exhibit enhanced rate performance and a long lifespan.
Dual-ZIF-derived “reassembling strategy” to hollow MnCoS nanospheres for aqueous asymmetric supercapacitors
Authors: Liu Song , Chen Kun , Xue Changguo , Nie Shibin , Li Jianjun , Zhu Jinbo
Published: August 2022

A facial and novel “reassemble strategy” was demonstrated to synthesize hollow MnCoS nanospheres from dual-ZIF. Optimized MnCoS nanospheres exhibits a high specific capacity of 957 C g−1. An MCS-5//AC ASC delivers a specific energy of 36.9 W h kg−1.
P-doped porous carbon derived from walnut shell for zinc ion hybrid capacitors
Authors: Sun Haibin , Liu Congcong , Guo Dongfang , Liang Shuangshuang , Xie Wenhe , Liu Shenghong , Li Zijiong
Published: August 2022

A P-doped porous carbon cathode material from walnut shell is assembled with zinc foil to form typical ZHCs, which showed excellent energy storage characteristics and long-life cycle stability.
Upconversion fluorescence of MXene nanosheets and the sensitive detection of l-tryptophan
Authors: Wang Feng , Wang Hongye , Cui Xiaoqiang , Liu Yang
Published: August 2022

The unique up-conversion fluorescence behavior of Ti3C2 MXene nanosheets was reported for the first time and was applied in the highly sensitive and selective analysis of l-tryptophan.
Platinum deposition on functionalised graphene for corrosion resistant oxygen reduction electrodes
Authors: Rubio Noelia , Suter Theo , Rana Zahra , Clancy Adam J. , Masuda Seigo , Au Heather , Coulter Gabriel , Sirisinudomkit Pichamon , McMillan Paul F. , Howard Christopher A. , Mattevi Cecilia , Brett Dan J. L. , Shaffer Milo S. P.
Published: August 2022

Functionalisation of graphene with functional groups affords promising supports for electrocatalysts due to their improved durability and enhanced specific activity compared to commercial systems.
Solid solution reinforced V3CrC3TxMXene cathodes for Zn-ion micro-supercapacitors with high areal energy density and superior flexibility
Authors: Wang Haoran , Xue Yaqing , Song Xin , Lei Shulai , Yu Hong , Du Cheng-Feng , Ren Zewei , Guo Ruisheng , Zhou Feng
Published: August 2022

Partial Cr substitution for V in the V4C3TxMXene promotes the capacitance, discharging potential, and cycle stability of in-plane ZMSCs. The device exhibits a high areal energy density of 51.12 μW h cm−2and flexibility index of 100.
Nano-engineering induced Bi dots in situ anchored into modified porous carbon with superior sodium ion storage
Authors: Chen Jun , Xiao Jun , Li Jiayi , Gao Hong , Guo Xin , Liu Hao , Wang Guoxiu
Published: August 2022

As the anode of sodium ion batteries, Bi dots in situ embedded in a 3D porous carbon matrix (Bi@MC) enables high ICE (88.13%) and long cycle life with 100% capacity retention at 2.5 A g−1.
Liquid metal-based electrosynthesis of stratified zinc–organic frameworks
Authors: Zheng Jiewei , Mousavi Maedehsadat , Baharfar Mahroo , Sharma Astha , Kumeria Tushar , Han Jialuo , Kumar Priyank , Kalantar-Zadeh Kourosh , Mayyas Mohannad
Published: August 2022

Post-transition metal-based liquid alloys are emerging as media for undertaking chemical reactions.
Intrareticular electron coupling pathway driven electrochemiluminescence in hydrogen-bonded organic frameworks
Authors: Hou Hanlin , Wang Yunlei , Wang Yufei , Luo Rengan , Zhu Da , Zhou Jun , Wu Xiaojun , Ju Huangxian , Lei Jianping
Published: August 2022

The eclipse-stacked hydrogen-bonded organic framework exhibits ultrafast excited carrier dynamics, thus remarkably accelerates radical annihilation through intrareticular electron coupling pathway for enhanced electrochemiluminescence.
P25-induced polydopamine conformal assembly on Cu2O polyhedra for hydrophilic and stable photoelectrochemical performance
Authors: Sun Lilai , Han Lu , Li Na , Wang Pengbo , Wang Mingyue , Luo Xudong , Li Xibao
Published: August 2022

The hydrophilic Cu2O/PDA/P25 composite photocathode has outstanding PEC water reduction performance.
Language-Fair Fast Mapping and Mutual Exclusivity Tasks for Mono- and Bilingual Preschoolers
Authors: Belogi Solène , Segerer Robin , Volpin Letizia , Skoruppa Katrin
Published: August 2022

Purpose:

Both monolingual and bilingual children use learning constraints and heuristics to acquire new words from their environment. Overall, fast mapping abilities seem to be similar in both populations, but monolinguals rely more than bilinguals on the mutual exclusivity strategy. Our study probes the robustness of these results in a large group of children learning different language combinations, with a newly devised language-fair task that relies as little as possible on previous linguistic knowledge, in order to avoid disadvantaging bilingual children.

Method:

We tested 138 3- to 5-year-old mono- and bilingual children in their dominant language (German, French, Italian, or Turkish) in a computerized task starting with a fast mapping phase, followed by a mutual exclusivity phase, using only invented nonobjects and nonwords.

Results:

As hypothesized, monolingual and bilingual children showed similar results during the initial fast mapping stage, but monolinguals relied significantly more on the mutual exclusivity strategy than their bilingual peers.

Conclusions:

The language-fair design of our task supports the idea that differences in mutual exclusivity strategy use between mono- and bilingual children really stem from their specific linguistic background, and not from potential familiarity differences with respect to the test words. We discuss the implications of our results for bilingual language assessment in clinical or educational contexts.

Supplemental Material:

https://doi.org/10.23641/asha.20669214
Dysphagia and Methamphetamine Use: Considerations for Speech-Language Pathologists
Authors: Faust Lauren G.
Published: August 2022

Purpose:

Methamphetamine use increases the risk of medical conditions that may cause oropharyngeal dysphagia. This tutorial describes what is known about methamphetamine's effects and draws connections to a speech-language pathologist's (SLP's) practice in dysphagia assessment and treatment with this population.

Method:

Methamphetamine's mechanism of action and prevalence of use are explored. Research in speech-language pathology and related fields such as dentistry, pharmacology, psychology, and public health provides insights into how this drug may impact oropharyngeal swallowing function and treatment participation.

Conclusions:

Methamphetamine can have a profound impact on the user's medical, cognitive, and psychosocial status. Although patients with a history of methamphetamine use are commonly seen by SLPs, there is a lack of direct research investigating potential implications of use on swallowing physiology and treatment progress. Future directions for research are discussed.
Building-to-vehicle and vehicle-to-building concepts toward net zero energy building: A small solar house case study in China
Authors: Hou Yingzhen , Zhu Neng , Ni Shenyang , Zhang Zhiyuan
Published: August 2022

In the future, the number of electric vehicles will increase significantly, promoting the integration of renewable energy into buildings and electric vehicles, which helps to achieve energy greening in transportation and architectural fields. The system includes renewable energy, buildings, electric vehicles, and energy storage systems. In this paper, the mathematical model of each system is established, and the electricity consumption of the building and the power generation of PV panels are predicted by the Energyplus software, and the economic evaluation index is proposed. In addition, the research analyses the effect of electric vehicles as electrical vectors in integrated PV panels and storage. The small solar residential data shows that through building-to-vehicle and vehicle-to-building solutions, on-site renewable energy utilization can be achieved, which is also conducive to building a zero-energyconsumption home.
A Case Study for BMPV Systems Optimal Day-Ahead Scheduling and performance evaluation
Authors: Yuan Yue , Chen Yixing
Published: August 2022

Optimal scheduling of a distributed energy resources system (DERs) can be beneficial for utilizing renewable energy and relieving the pressures upon the main electric grid. One of the most popular DER systems is the Building mount photovoltaic (BMPV) system. In this paper, a large office building is taken as a case study to develop an optimal day-ahead strategy for the BMPV system considering 24 hours ahead of energy consumption and PV generation uncertainty. This paper mainly includes BMPV system capacity determination, 24 hours ahead of energy usage and PV generation forecasting, and day-ahead optimal strategy development. Firstly, based on collected history energy demands, weather data, and building information, the install capacity of PV is defined by roof area. Furthermore, the battery capacity is constructed by China's latest photovoltaic energy storage capacity standard. Secondly, the ensemble learning model is established using a time-series algorithm and Long Short-term memory (LSTM) to predict day-ahead energy consumption. Moreover, an interval prediction method is used to forecast the PV generation for the next 24 hours. Finally, the accurate energy consumption prediction and PV generation interval are introduced to establish the BMPV system scheduling strategy. The day-ahead optimization scheduling strategy was developed based on Mixed integer linear programming (MILP), targeting minimal economic cost. As a result of the optimization process, the proposed strategy could save 4.8% in economic costs and reduce the peak load of the main grid effectively. Moreover, it can effectively optimize the energy consumption structure of buildings or even distributed energy systems and can provide feasibility to achieve net-zero energy consumption without sacrificing any comfort of occupancy.
Development of a method for numerical modeling of the separation flow at the entrance to a rectangular exhaust channel with sharp edges
Authors: Logachev Konstantin , Ziganshin Arslan , Huang Yanqiu , Wang Yi , Averkova Olga , Gol’tsov Alexander , Sedova Anna
Published: August 2022

We have developed a method for mathematically simulating flow separation at the entrance to the exhaust channels of rectangular shape, using stationary discrete vortices in an ideal incompressible liquid in full spatial setting. When designing the discrete model, straight and curvilinear quadrangular vortex frames, straight and curvilinear horseshoe-shaped vortices were used. Using the developed computational procedure and computer program, the outline of vortex zone at the entry to the rectangular exhaust channel with sharp edges and the axial velocity of the air flow are determined. The results were compared with studies by different authors, as well as calculations by the methods of the theory of functions of a complex variables for the slotted exhausts and with results earlier obtained by us for calculation the square exhaust opening by means of discrete vortices in non-stationary and quasi-symmetric setting. The further direction of research will be related to the investigation of flows detached at the entrance to the rectangular exhaust hoods by the developed method, as well as by CFD methods. Then it is necessary to identify the regularities of the change of the local resistance coefficient at the entrance to the exhaust hood, shaped by the found outlines of the vortex zones.
Evaluation of the performance of ventilative cooling systems with different control parameters
Authors: Hu Yan , Ai Zhengtao , Zhang Guoqiang
Published: August 2022

To evaluate the performance and energy savings of different ventilative cooling systems, three mixed forms of ventilative cooling were described and the most promising rule-based heuristic control criteria were used as applicable control strategies based on various control parameters. Parametric analyses including the ventilative cooling set-points and control frequencies have been conducted. EnergyPlus was used to perform the aforementioned analyses based on a typical office building. Case studies verified that the use of different control parameters led to different indoor air environment and energy performance in a certain climatic zone. Then, the percentages outside the range indexes (POR) of the three mixed forms of ventilative cooling with various control parameters in five representative climatic zones in China were calculated, the results demonstrated that the ventilative cooling performance was mainly related to the ventilative cooling form in HSCW, HSWW, and temperate climatic zones. While in cold and severe cold climatic zones, it was mainly affected by selection of control parameters and its corresponding set-points. It can provide guidance for the selection of ventilative cooling scheme capable of maintaining indoor environment level with a low energy consumption in different climatic zones of China.
Research on the Influence of Ventilation Mode on the Condensation Risk at the Wall Radiant Terminal
Authors: Li Zhengrong , Yu Wenxuan , Wang Heyu , Feng Xiwen
Published: August 2022

The separate control of indoor heat and humidity in radiant air conditioning has more energy-saving advantages than convection air conditioning that use the same cold source to handle heat and humidity loads, which is in line with the international trend of carbon reduction and emission reduction. However, the surface of the radiation terminal is prone to condensation, which poses a health and safety hazard. In order to reduce the risk of condensation at the wall radiant terminal, this paper uses CFD to study the effect of ventilation mode on the risk of condensation at the wall radiant terminal, and evaluates the risk of condensation by using the term of the minimum supercooling condensation temperature. The simulation results show that the thermal boundary layer on the surface of the radiant terminal under different ventilation velocity is different, which affects the minimum supercooling condensation temperature, and makes the condensation risk of the radiant air conditioning system different. When the wind speed of the attached jet is 1.07 m/s, the thickness of the thermal boundary layer is 0.045 m, and the minimum supercooling condensation temperature at the radiation terminal is 1.79 K. By further increasing the wind speed and reducing the thickness of the thermal boundary layer, the minimum supercooling condensation temperature can be further increased to 2.2 K, reducing the risk of condensation.
Comparative analyses of the air distributions created by attached ventilation with different air outlets
Authors: Li Jiaxing , Li Angui , Ma Yuanqing , Ma Jiangyan , Huang Lin
Published: August 2022

As an innovative ventilation mode, attached ventilation has been widely used in different types of buildings due to its high ventilation efficiency and energy saving. At present, the commonly used air outlet form is slot outlet. Considering the diversity of application places, different air outlet form models (Slot outlet (SO), Rectangular outlet (RO), Circular outlet (CO), Semi-circular outlet (SCO)) were established in this paper. Air distributions of the attached ventilation under different air outlet forms are analyzed and compared. The results show that the attached jet thickness is larger under RO, CO, and SCO form. Compared with SO form, the jet velocities of other three forms decay slowly in the vertical region. The attached ventilation with different outlet forms can form an "air lake" in the occupied zone to ensure the comfort environment. This research provides design references for the design and application of the attached ventilation under different air outlet forms.
Heating performance of heating floor integrated with impinging jet ventilation system
Authors: Zhou Bin , Yang Bin , Li Zhe , Li Angui
Published: August 2022

Radiant floor heating systems provide comfortable indoor thermal environment. Primary air supply systems can be used to remove contaminants in the space heated by radiant floor. In this study, heating performance of integrated system of impinging jet ventilation (IJV) and heating floor was numerically investigated. The lowest floor heating capacity was 0 W/m2 and gradually increased to 50W/m2, and the primary air temperature supplied by IJV were 14, 16 and 18°C, respectively. In terms of contaminant removal efficiency, contaminant removal efficiency (CRE) was applied. The vertical dimensionless temperature distribution was used to analyse the heating performance of HF on supply air. The numerical results showed that the supply air layer of IJV could be heated by 60% to 80% under the heat effect of HF. The same is true for low supply air temperature 14 °C. The integrated system IJV/HF generated the weaken thermal stratification which is beneficial for energy saving. The CRE of IJV/HF system was influenced by the downward airflow of external wall. Sufficient supply air could overcome the downflow and effectively increase the CRE value (> 2).
Phase change materials influence on temperature variatio buildings
Authors: Zhou Hongxia , Andersson André , Olofsson Thomas
Published: August 2022

For the design of sustainable buildings, it is crucial with accurate methods to evaluate how alternative constructions will influence thermal comfort, as well as energy efficiency. This study introduces a model to investigate how the use of phase change materials (PCM)in building envelopes can influence the temperature stratification, which also influences the indoor thermal comfort. PCM is characterized by large latent heat in the melting/solidifying process during phase transition. Applications with PCM have been recognized as possible alternatives in building envelopes to improve thermal comfort as well as energy efficiency. The selection of the properties of the PCM, as well as how and where the PCM was installed in the building envelope, are crucial factors to be considered before application in practice.

In this study, a simplified experimental set-up including a hot-box was used. The PCM material Climsel28 with different layers thicknesses was installed in the sidewall of a hot-box. Extruded polystyrene (XPS) foam boards were used as wall insulation material in the study. XPS was installed as a reference case and in different layer combinations with the PCM. The sequence of the XPS and PCM was varied. Temperature and heat flux were measured in different positions of the hot-box and on the tested walls. A 3D COMSOL model was developed to study the thermal performance of the system. The model was validated in the study using the collected experimental data. The results indicated that the developed COMSOL model can reasonably predict the performance of the system, both with and without the incorporation of PCM. Additionally, the measured temperature stratification were theoretically validated by the COMSOL model. The study gives indicative guidance of how PCMs can be installed in building constructions elements to reduce temperature peak loads and thus also contributing to an improvement of the indoor thermal comfort.
Optimized design and energy consumption simulation of window-wall ratio in Yanqui Library, Jimei University
Authors: Cheng Li , Tao Qiuhua , Tang Yubin
Published: August 2022

The size of the window-to-wall ratio is a key factor affecting the natural lighting, ventilation and energy consumption of a building. Taking the Yanqui Library of Jimei University as the object and combined with different shading conditions, the range of window-wall ratios that simultaneously meet the requirements of natural lighting and energy saving is derived by using Revit, Ecotect and PKPM software simulations around lighting, energy consumption and natural ventilation. The main conclusions are as follows:(1) With the use of external shading, 0.53 is the maximum window-to-wall ratio for west-facing rooms to meet lighting and energy-saving requirements. (2) The window ratio in the west room is not greater than 0.38, and the north-south room is not greater than 0.55, and the average indoor wind speed in the transitional season is not greater than 0.5m/s.
Numerical simulation study on optimization of ventilation airflow organization of a raw coal bunker
Authors: Zhang Qianru , Yang Luying , Shi Xiaoyan , Wang Xin
Published: August 2022

For the problem of gas accumulation in the product bunker of a company’s coal processing plant, three different ventilation schemes are proposed. The first one opens rectangular air inlet louvers on the wall of the product bunker and adds fans on the top for exhaust; the second one sets six ventilation windows evenly on the top of the product bunker for natural ventilation; the third one sends air to the interior of the bunker through small holes evenly distributed on the ventilation pipes and opens six exhaust ports on the wall. Finally, the effect of gas accumulation management of the ventilation scheme is simulated and analyzed through numerical simulation. The ventilation scheme is applicable to the gas accumulation management of raw coal bunkers with different coal storage heights, and provides a technical reference for the gas accumulation management of product bunkers in coal processing plants.
Simulation research on airflow distribution performance of solar greenhouse heating system in northwest China
Authors: Cui Zhijie , Hu Wanling , Zhang Yilin , Ji Tianxu , Li Wenlong , Guan Yong
Published: August 2022

Combined with the structure of the solar greenhouse, this paper proposed a new type of solar greenhouse heating and ventilation system with the framework of the solar greenhouse as the carrier of heating and ventilation. The system’s return air mode, tuyere type, tuyere installation position and aperture ratio were determined by computational fluid dynamics (CFD). The results showed that: 1) When the inlet wind speed was 10m/s and the temperature was 37°C, using the upper return air method, the average temperature of the greenhouse crop area increases by 14.7°C, which was greater than 1.3°C of the lower return air and 2.3°C of the middle return air, the heating effect was the best. 2) Based on the nozzle and slot-type tuyere, five kinds of air outlets were designed. It was found that the use of the nozzle-type air outlet could promote the circulation effect of the airflow in the greenhouse and send more heat to the crop area. 3) When the aperture ratio was controlled at 1.5, the number of air outlets has little effect on the greenhouse heating effect.
A preliminary research on the periodic characteristics of a ventilation system with fluid oscillator
Authors: Liang Bing , Wang Haidong
Published: August 2022

The fluid oscillator is a device that produces periodic alternating jets by supplying a certain pressure of the fluid. In this paper, the fluid oscillator is applied to the field of building ventilation. The supply air direction will change periodically and create a vortex shedding effect in the ventilated environment. By establishing a three-dimensional model of the double feedback fluid oscillator, CFD numerical simulation technology was used to study the indoor flow field characteristics when the fluid oscillator was used for ventilation and the slit air supply. The results show that the influence area of slotted air is small, and the energy is concentrated and distributed. Only a few eddies are generated on both sides of the main jet, and many stagnation zones are generated indoors. Fluid oscillator ventilation into the indoor airflow has a broader range of influence. The flow field distribution is uniform, and the jet energy dissipates quickly. The fluid oscillator will generate many eddy currents inside the room, effectively reducing the airflow stagnation zone in the room. Because the fluid oscillator can accelerate the disturbance of the flow field inside the room, it has a particular reference value to optimize the indoor air distribution.
Numerical study of double-diffusive mixed convection of heavy gas in ventilation room
Authors: Zhang Ying , You Tao , Wen Xiaoqi , Zhao Chenbo , Li Angui
Published: August 2022

More than 90% of the toxic gas in the industrial production process is heavy gas. However, under non-isothermal conditions, due to the uncertainty of the direction of buoyancy, the traditional ventilation method cannot be used to discharge heat and pollutants. In this study, we adopted the method of numerical simulation. The model used in this study is a two-dimensional double-diffusion model. The typical heavy-specific gravity gas sulphur hexafluoride (SF6) is used for the pollutants. When the buoyancy ratio is -1, the diffusion law of heavy gas pollutants under non-isothermal conditions is discussed. The results show that the temperature distribution and the pollutant distribution are mainly affected by the size of the vortex on the surface of the pollution source and the heat source. The temperature ventilation efficiency and the average Nu trend are similar, and put forward the optimal ventilation intensity relational formula in the square cavity.
A novel design of dehumidifier system in underground pumped storage power station
Authors: Yao Huimin , Li Ang , Lv Yuling , Shen Xiong
Published: August 2022

The heavy water condensation problem has led to safety concern for the workers and electrical facilities in the underground pumped storage power station. As for current dehumidification scheme, heat and humidity load are all removed through the air conditioning unit, which has high energy consumption and low efficiency. As a large amount of moisture comes from the external fresh air, in this study, we set the dehumidification system in the underground ventilation tunnel. By using the air inlet channel to lighten the wet load, the heat and humidity parameters of the fresh air are processed as far as possible in the front of the air supply, so as to achieve the purpose of energy saving operation. In this study, numerical modelling was used to simulate the control scheme of the heat and humidity environment. Compared with the traditional method, the two new dehumidification schemes can take about 1/3 of the wet load of the main workshop, and the dehumidification efficiency is improved. Therefore, this study is expected to be a promising tool for reducing air humidity in underground workshops.
Modelling ventilation and convective heat transfer in deeply buried underground tunnels based on boundary layer theory
Authors: Guo Jinnan , Li Angui
Published: August 2022

Underground traffic tunnels serve as the entry and exit buildings for underground spaces. Most of the ventilation and air-conditioning systems in underground spaces rely on traffic tunnels for cooling or preheating to save energy. The temperature distribution of traffic tunnels has always attracted the attention of researchers. In this study, a heat transfer model of a traffic tunnel was established based on energy conservation and boundary layer theory, and the field test was carried out. The calculation model provided in this study was in good agreement with the field measurement results. It is found that the dimensionless air temperature of the traffic tunnel decays exponentially along the tunnel at the same time. The air temperature in the traffic tunnel fluctuates with time, and the simple harmonic fluctuation decreases along the tunnel. In summer, the air temperature decreases and increases exponentially along the tunnel during the day and night, respectively. In this study, a heat transfer model for calculating the temperature distribution of underground traffic tunnels was theoretically established, which provided an important theoretical support for underground traffic tunnels as natural air conditioners. The establishment of heat transfer model of underground traffic tunnel has significant economic and environmental benefits.
Study on the Influence of Moisture Dissipation on the Thermal and Humidity Environment in the Turbine Floor of Underground Pumped Storage Hydropower Plants
Authors: Lu Huimin , Tu Dengkai , Li Junmei , Li Yanfeng
Published: August 2022

The turbine floor of the main plant is an important part in an underground pumped storage hydropower plants.The health of personnel and the safe operation of equipment are endangered due to high space humidity and water seepage through the walls. In this paper, numerical simulations were used to study the thermal and humidity environment of the main plant turbine floor in summer. Two working conditions with and without the dissipation of humidity are computed and compared. The psychrometric chart was also used to analyze the air treatment process in the turbine floor. Results show that the air temperature decreases by 28% and the relative humidity increases by 34% when considering the effect of the moisture dissipation source. The results of temperature and humidity analyzed by the psychrometric chart are similar to those of numerical simulation. And validition of the numerical method is conducted . The research results have a reference significance for predicting the relative humidity distribution of the turbine floor and the arrangement of dehumidification devices at design stage .
Research on spatial local resistance characteristics in a plenum space for an exhaust fan room
Authors: Chen Chao , Su Zhihe , Zhao Shouchong , Li Yanfeng , Tian Wei
Published: August 2022

The local resistance loss is of great importance to the structural design of the exhaust room and the selection of fan equipment. In this study, the resistance characteristics of isotropic multi-inlet and single-outlet plenum spaces are investigated using numerical simulations. Orthogonal experiment method was used to determine the key influencing factors. An empirical formula for the local resistance loss law was proposed and the internal flow characteristics of the plenum space were analysed. Results show that the fan interaction rate is an important factor for the drag loss and that the vortex zone is closely related to the magnitude of the local drag loss. The results can provide a theoretical basis for the structural design of the plenum space and the selection of fan equipment.
Study on ventilation effect for a large space in an underground hydropower station
Authors: Su Zhihe , Li Yanfeng , Tian Wei
Published: August 2022

Due to the urgent need for reducing carbon emissions, an increasing number of pumped storage power stations have been constructed and used considering its obvious advantages of energy saving. However, relevant design guidance and technical research failed to meet the development demand. There is only a small number of studies focusing on the prediction and evaluation of ventilation system in singlestory stations, however, little on the integral connected plant floors. Thus, it is significant to study safety operation technology of deep underground pumped storage power stations, especially in terms of thermal and humidity environment. A reduced-scale (1/30) model based on an engineering project was set up, and numerical simulations were carried out to study the temperature and velocity distribution in the large underground space under the summer design condition (L=21.1×104m3/s, T=19°C, Q=997KW). Results show that the temperature on the right side of the powerhouse is slightly higher than that on the left side, and the gap is approximately from 1°C to 4°C. Moreover, local overheating may occur in some places. The side air supply velocity and location should be paid more attention to in designing air distribution.
Field measurement of indoor environment of underground garage in winter and analysis of its influence on people
Authors: Zheng Zhanjiang , Lei Wenjun , Wang Haocheng , Fu Jinming , Sun Guohong
Published: August 2022

Since the National Fitness has become a national strategy, people’s enthusiasm for fitness has also been increasing. When winter comes, the outdoor temperature becomes unsuitable for people to carry out exercise activities. Therefore, more community residents choose underground garages as a place for fitness activities. Due to the frequently entry and exit of vehicles and ventilation restrictions in the underground garage, whether the internal air quality in an underground garage meets the requirements of personnel activities remains to be studied. In this study, an underground garage in a residential area of Jinan was tested. The parameters involved CO2, CO, PM2.5, temperature and relative humidity. Select areas where people often gather for measurement. According to the test results, the distribution of CO2, CO, PM2.5, temperature and relative humidity in the underground garage were quantitatively analyzed. It is found that the air quality in some areas of the underground garage is poor, and long-term activities in this environment will affect people’s health. To solve this problem, in this study, the area with relatively good air quality in the underground garage is found to provide personnel activities, and the optimization measu.res of winter ventilation in the underground garage were put forward.
Optimization of Ventilation System for a Main Power Plant in an Underground Pumped Storage Power Station
Authors: Lei Chentong , Xu Desheng , Feng Shan , Li Yanfeng , Lu Huimin
Published: August 2022

Pumped storage power station is an economic and reliable means of peak load regulation for power networks. The temperature and humidity control are complicated due to the huge amount of heat and moisture emission in the main power plant. This paper investigates the operating condition of three different ventilation cases in a five-storey underground pumped storage power station. A full-scale model of the main plant was built for numerical simulation. Three ventilation cases were studied by changing the number, area and layout of air supply vents at the top of the main plant. The airflow distribution of three cases in summer condition were calculated and an optimal ventilation case was determined by comparing the jet flow range and temperature in the working zone. The working condition in winter was also simulated and verified in order to ensure the reliability of the ventilation case. Results show that case 1 was determined as a reasonable air supply case. In this paper, a reasonable scheme of ventilation system was proposed in a underground pumped storage power station. The results would be helpful to optimize the air ventilation mode in underground powerhouse of pumped storage power station.
Numerical Simulation of Bus Bar Hole Ventilation in Jinghe Dongzhuang Hydropower Station
Authors: Tong Ren , Zhengye Wang , Hong Zhang , Zhengguang Xu , Xiaoke Chang , Ran Gao
Published: August 2022

Based on the boundary conditions obtained from the actual measurements during the infrastructure period of Jinghe Dongzhuang Power Station, a calculation model of the predicted bus bar hole environment was established, and a full-scale numerical simulation of the bus bar hole environment was performed based on CFD to analyze the effect of air supply velocity changes on the temperature and velocity fields in the working area. The ventilation effect is evaluated and compared by calculating the inhomogeneity coefficient and air distribution characteristic index. The study shows that an appropriate increase in air velocity can reduce the thermal impact of the internal heat source on the surrounding environment and can effectively control the air quality in the work area. Considered comprehensively, the work area has better comfort when V/V0 is slightly greater than 1. The research results have some guiding significance for the design of bus bar hole air supply system in Jinghe Dongzhuang Power Station.
Simulation study on the dynamic velocity field of the supplying jet coupled with the platform piston wind in non-screen door subway stations
Authors: Zhu Jialiang , Wang Lihui , Li Zhiling , Ma Jianan , Ma Changjiang , Yang Xinwei
Published: August 2022

The coupling airflows of platform piston wind and station air-conditioning supply air is the most typical airflow organization of non-screen door subway station platform. By establishing a CFD software model of the coupling process between piston wind and air-conditioning supply air in subway station platform, the velocity field of the coupled airflow in the platform under different vehicle conditions is numerically simulated. It has been found that: when the train enters the station, the maximal piston wind velocity can reach 8 m/s with the air-conditioning supply air near the approach end significantly affected by the piston wind than at other positions. The study can provide a theoretical basis for the optimization of the airflow organization and energy consumption in the non-screen door subway station platform.