Large Chamber Research Articles

Actuators linearization of a large volume environmental simulation chamber via pulse code modulation

Ultra-stable room-sized environmental chambers may involve significant power variations leading to hysteresis and nonlinearities of the stabilization system. This paper describes utilization of a pulse code modulation control which significantly reduces observed nonlinearity of the chamber actuation system. Stability of environmental conditions for temperature ΔT=±25 mK (15–35 °C dynamic range), relative humidity ΔRh=±0.1% (3%–95% dynamic range), and pressure ΔP=±12 Pa (±500 Pa dynamic range) was achieved within 27 m3 chamber volume, which is two orders of magnitude better than the corresponding stabilization achievable using a standard linear proportional–integral–derivative (PID) controller. Utilizing this chamber we have demonstrated two orders of magnitude improvement of the operational relative frequency stability of ultrastable quartz oscillators (USO), reaching 2×10−13 stability at 1-105 s averaging time.

Pulpotomy Treatment of Taurodontic Teeth

Background: Taurodonsia is a dental anomaly that undergoes vertical dilation of the pulp chamber and has a short root. Teeth with taurodonsia affected by caries to the pulp must be treated endodontically first before restoration. Case Report: a 4-year-old girl came in complaining of cavities in her lower jaw. After clinical examination, 84 teeth experienced deep dentin caries and from the results of radiographic photos, it was found that caries was almost close to the pulp horn with a large pulp chamber and short roots. The endodontic treatment carried out is pulpotomy and after that the final restoration uses a stainless steel crown. Conclusion: Taurodontia is a rare occurrence that requires a thorough clinical and radiographic examination to aid diagnosis and appropriate treatment planning. Pulpotomy can be an endodontic treatment option for primary teeth experiencing taurodontia based on objective and subjective considerations of the patient's condition

On the expression of reproductive plasticity in Drosophila melanogaster females in spatial and socially varying environments.

Individuals often adjust their behaviour based on their perception and experiences with the social and/or physical environment. In this study, we examined the extent of reproductive plasticity expressed in mating rates, mating latencies, mating durations, and offspring production in female fruit flies, Drosophila melanogaster , that encountered different numbers of males in different sized chambers. We found that mating latency length decreased with more courting males and smaller environments and that matings durations were longer in larger chambers and in the presence of two males. These results illustrate the sensitivity of these behavioural phenotypes to changes in local environmental conditions.

Data handling of CYGNO experiment using INFN-Cloud solution

The INFN Cloud project was launched at the beginning of 2020, aiming to build a distributed Cloud infrastructure and provide advanced services for the INFN scientific communities. A Platform as a Service (PaaS) was created inside INFN Cloud that allows the experiments to develop and access resources as a Software as a Service (SaaS), and CYGNO is the betatester of this system. The aim of the CYGNO experiment is to realize a large gaseous Time Projection Chamber based on the optical readout of the photons produced in the avalanche multiplication of ionization electrons in a GEM stack. To this extent, CYGNO exploits the progress in commercial scientific Active Pixel Sensors based on Scientific CMOS for Dark Matter search and Solar Neutrino studies. CYGNO, like many other astroparticle experiments, requires a computing model to acquire, store, simulate and analyze data typically far from High Energy Physics (HEP) experiments. Indeed, astroparticle experiments are typically characterized by being less demanding of computing resources with respect to HEP ones but have to deal with unique and unrepeatable data, sometimes collected in extreme conditions, with extensive use of templates and montecarlo, and are often re-calibrated and reconstructed many times for a given data set. Moreover, the varieties and the scale of computing models and requirements are extremely large. In this scenario, the Cloud infrastructure with standardized and optimized services offered to the scientific community could be a useful solution able to match the requirements of many small/medium size experiments. In this work, we will present the CYGNO computing model based on the INFN cloud infrastructure where the experiment software, easily extendible to similar experiments to similar applications on other similar experiments, provides tools as a service to store, archive, analyze, and simulate data.

Wildfire plume ageing in the Photochemical Large Aerosol Chamber (PHOTO-LAC).

Plumes from wildfires are transported over large distances from remote to populated areas and threaten sensitive ecosystems. Dense wildfire plumes are processed by atmospheric oxidants and complex multiphase chemistry, differing from processes at typical ambient concentrations. For studying dense biomass burning plume chemistry in the laboratory, we establish a Photochemical Large Aerosol Chamber (PHOTO-LAC) being the world's largest aerosol chamber with a volume of 1800 m3 and provide its figures of merit. While the photolysis rate of NO2 (jNO2) is comparable to that of other chambers, the PHOTO-LAC and its associated low surface-to-volume ratio lead to exceptionally low losses of particles to the walls. Photochemical ageing of toluene under high-NOx conditions induces substantial formation of secondary organic aerosols (SOAs) and brown carbon (BrC). Several individual nitrophenolic compounds could be detected by high resolution mass spectrometry, demonstrating similar photochemistry to other environmental chambers. Biomass burning aerosols are generated from pine wood and debris under flaming and smouldering combustion conditions and subsequently aged under photochemical and dark ageing conditions, thus resembling day- and night-time atmospheric chemistry. In the unprecedented long ageing with alternating photochemical and dark ageing conditions, the temporal evolution of particulate matter and its chemical composition is shown by ultra-high resolution mass spectrometry. Due to the spacious cavity, the PHOTO-LAC may be used for applications requiring large amounts of particulate matter, such as comprehensive chemical aerosol characterisation or cell exposures under submersed conditions.

Ultralow H2O content analysis with a large-geometry secondary ion mass spectrometer

An improved LG-SIMS (CAMECA IMS 1280-HR) procedure for achieving sub-ppm LOD for water analysis by updating the cooling trap.

Meta-analysis of the correlation between pulmonary hypertension and echocardiographic parameters in patients with chronic kidney disease.

To investigate the correlation between pulmonary hypertension (PH) and echocardiographic parameters in patients with chronic kidney disease (CKD). PubMed, Embase, Web of Science, Cochrane, VIP, CNKI, and Wanfang databases were systematically searched for articles published from inception to 19 May 2023. Study quality was estimated using the Quality Assessment of Case-Control Studies tool. Forest plots were drawn using R language software. The "metacor" function in the "meta" package was utilized for meta-analysis of the r-values and their standard errors. Heterogeneity and sensitivity analyses were carried out, with the main outcomes as r-value, p-value, and I2 value. Eleven studies were included, with 1,809 CKD patients. The correlations between 12 echocardiographic parameters and PH were analyzed. Except for FS and LVEF which were negatively correlated with CKD-PH, the other 10 parameters were positively correlated with CKD-PH. Among them, LA was highly correlated with CKD-PH (0.70 < r < 0.89); LVDD, RA, RV, LVMI, and LVDS were moderately correlated with CKD-PH (0.40 < r < 0.69); while PA, IVS, LVPW, SV, FS, and LVEF were lowly correlated with CKD-PH (0.20 < r < 0.39). The synthesized estimates were stable against heterogeneity. CKD-PH patients may have large cardiac chambers, thickened septal tissue on both sides of the chambers, reduced pulmonary artery flow rates, and decreased left ventricular function.

Use of laser scanning and 3D software in mining design

The article presents the results of laser scanning measurements in horizontal and vertical headings of copper ore mines in Poland. Laser scanners are used primarily for the inventorying of large chambers or workings that are difficult to access. The point clouds obtained from the measurements are processed in CAD programmes, the study then examined examples of their use in underground mining. The examples included the use of scans for modernisation projects and for designing new mine workings. This paper explores the integration of laser scanning and 3D software as a powerful toolset for enhancing various aspects of mining design. Through the accurate capture of spatial data using laser scanning technologies, detailed representations of mining environments can be generated, enabling engineers to create precise digital models of underground workings, open-pit mines, and associated infrastructure. Furthermore, the integration of 3D software facilitates the manipulation and analysis of this captured data, allowing for the development of comprehensive design solutions. By leveraging the capabilities of 3D modelling and simulation tools, mining engineers can conduct virtual assessments of proposed designs, identify potential risks and inefficiencies, and optimize operational layouts to maximize productivity and safety. This paper reviews the methodologies and applications of laser scanning and 3D software in mining design, highlighting their contributions to key aspects such as geological modelling, slope stability analysis, ventilation planning, and equipment optimization.

Research on pressure transmission and sealing performance of pyrophyllite in a cubic large chamber static high-pressure device

Owing to the need for a hydrostatic high-pressure cubic large cavity (hexahedral top) press used in high-pressure research and production of superhard material, two kinds of pyrophyllite powder compacts (A and B) from pyrophyllite mine in South Africa are prepared, and compared with the domestic yellow pyrophyllite powder compacts (Mentougou, Beijing) produced by the same process, to establish experimental methods and physical criteria for evaluating the pressure transmission and sealing performance of pyrophyllite. During the experiment, standard pressure materials such as Bi, Tl, and Ba are used to &lt;i&gt;in-situ&lt;/i&gt; calibrate the pressure at the central positions and sealing edges of the pyrophyllite pressure chambers from the three aforementioned compacts under normal pressure conditions. Additionally, the silver melting point method is employed to obtain the corresponding relationship between chamber pressure at high temperature and system loading when using these three types of pyrophyllite as load-transmitting sealing materials. The results show that under the same hydraulic pressure loading, the difference in pressure at the central position between South African pyrophyllite B powder blocks and domestically produced pyrophyllite powder blocks does not exceed 0.1 GPa. Furthermore, in pressurization process and depressurization processe, the differences in pressure between the central position and the sealing edge of the pyrophyllite blocks are notably similar. Compared with South African pyrophyllite A powder blocks, pyrophyllite B powder blocks exhibit a closer resemblance to domestically produced pyrophyllite powder blocks in terms of high-temperature load transmission and sealing performance. Pyrophyllite B powder blocks from South Africa have the potential to serve as a substitute for domestically produced pyrophyllite without changing the existing superhard material synthesis process, making them promising candidates for use as load-transmitting media and sealing materials. These research findings hold significant academic importance in the realms of high-pressure research and superhard material production. They provide valuable insights into the selection of suitable transmission and sealing materials and the optimization of high-pressure experimental conditions. Additionally, this study presents robust method and criteria for experimental procedures and performance assessment.

Emplacement and ore potential of the Permian Pobei mafic–ultramafic complex, NE Tarim, NW China

A number of mafic–ultramafic intrusions with variable degrees of Ni-Cu sulfide mineralization occur in the northeastern Tarim Block and East Tianshan Orogenic Belt (NW China). Among them, the Pobei complex is composed of a gabbro body intruded by several ultramafic bodies including Poyi and Poshi. These bodies have similar mineralogy and chemical compositions and were derived from a common magma. Olivine crystals from the Poyi and Poshi bodies generally have high Fo contents with the highest Fo value of 89.5 and Ni up to 3300 ppm Ni, indicative of crystallizing from Ni-undepleted, high-Mg basaltic magmas. Sr-Nd-Pb isotopic compositions show that more mafic rocks show relatively low degrees of crustal contamination, whereas more evolved rocks experienced higher degrees of contamination, especially in the upper part of the complex. Olivine crystals from both the Poyi and Poshi bodies show sharp decrease of Ni with decreasing Fo values, indicating sulfide segregation in these two bodies. Gabbros may have potential of reef-type chromite mineralization at the deep level, and V-bearing magnetite mineralization at higher stratigraphic level corresponding to the current surface level, but the potential of PGE mineralization is low. We propose that the ultramafic bodies of the Pobei complex may have been formed from the injection of olivine- and sulfide-laden crystal slurry from the bottom of a large magma chamber. The Ni-Cu mineralization was triggered by the crustal contamination. The Pobei complex was formed by the multiple intrusions of magmas to form the current complex.

Taurodontism in primary molars: A case report

Taurodontism is a development disorder involving large pulp chambers with the furcal areas located closer to the root apex. The crowns of teeth associated with taurodontism appear normal and its distinguishing features are present below the cementoenamel junction. This makes the radiographic evaluation crucial for its diagnosis. Taurodontism is more commonly found in permanent teeth than in deciduous teeth. Taurodontism occurs mostly as a lone anomaly. Still, it is associated with certain syndromes including Down’s syndrome (Trisomy 21), Klinefelter’s syndrome, and a few medical conditions such as hypophosphatasia. From the perspective of endodontics, taurodontism demands greater efforts for root canal therapies than for a tooth with a normal pulp chamber. The reason is larger pulp chambers that pose obturation errors in the tooth and increase failure percentage. This paper discusses taurodontism associated with primary molars in a 4-year-old dental patient.

A patterned human primitive heart organoid model generated by pluripotent stem cell self-organization

Pluripotent stem cell-derived organoids can recapitulate significant features of organ development in vitro. We hypothesized that creating human heart organoids by mimicking aspects of in utero gestation (e.g., addition of metabolic and hormonal factors) would lead to higher physiological and anatomical relevance. We find that heart organoids produced using this self-organization-driven developmental induction strategy are remarkably similar transcriptionally and morphologically to age-matched human embryonic hearts. We also show that they recapitulate several aspects of cardiac development, including large atrial and ventricular chambers, proepicardial organ formation, and retinoic acid-mediated anterior-posterior patterning, mimicking the developmental processes found in the post-heart tube stage primitive heart. Moreover, we provide proof-of-concept demonstration of the value of this system for disease modeling by exploring the effects of ondansetron, a drug administered to pregnant women and associated with congenital heart defects. These findings constitute a significant technical advance for synthetic heart development and provide a powerful tool for cardiac disease modeling.

Investigating methods to quantifying uncertainty in PM2.5 emission rates from cooking by toasting bread

Exposure to airborne fine particulate matter (PM2.5) is linked to multiple negative health effects and indoor sources are important contributors to personal exposure. Cooking is a common indoor source, but reported emission rates have high variability. Methods to quantify uncertainty in PM2.5 cooking emission rates are investigated so that they can be used in probabilistic exposure models to evaluate interventions. Controlled tests were conducted to measure emission rates from the toasting of bread because it is simple and repeatable. Two methods were compared: residential kitchen field tests and large chamber tests. The theoretical peak calculation method was used to determine emission rates from time-resolved PM2.5 concentration measurements. The large chamber tests produced more consistent results than the residential field tests, with a coefficient of variance almost an order of magnitude lower due to the improved control of variables. Then, the emission rates were normally distributed with mean 0.23mg/min and standard deviation 0.067mg/min. However, this distribution may be less representative of normal behaviour. The resulting dataset can be combined with other sources to represent housing stock exposures in probabilistic models, enabling the exploration of exposure uncertainties and interventions. More generally, key recommendations when measuring PM2.5 emission rates include: high temporal resolution measurements; custom calibration factors; identifying periods for emissions, mixing, and decay; constant ventilation rates; quantifying mixing conditions; and ensuring high quality decay data.

Comprehensive investigation of a building integrated crossed compound parabolic concentrator photovoltaic window system: Thermal, optical and electrical performance

Integrating PV solar cells with concentrators into window systems can not only generate electricity for a building, but also has the potential to enhance the thermal resistance of the building's windows without a significant sacrifice of light transmittance for passive daylight. A novel system, known as the crossed compound parabolic concentrator photovoltaic window, has been recently studied for its electrical properties. However, its thermal and optical performance, particularly in terms of the overall heat transfer coefficient (U-value) and total optical transmittance when integrated into a building, remains unexamined. These factors are crucial for predicting the system's impact on a building's energy efficiency and indoor comfort. Therefore, this paper aims to investigate the U-value of this window system under various temperature scenarios and the optical transmittance of the window at different incident angles. The thermal conductance was assessed through numerical simulations using a computational fluid dynamics model, which was validated by experimental measurements conducted in a large climate chamber. The optical transmittance was investigated using a validated 3D ray-tracing model. The total optical transmittance and electricity generation were calculated for typical sunny days in winter and summer under London's climate conditions. Additionally, alternative designs were developed to explore the impact of pitch between adjacent optics on the thermal conductance and optical transmittance of the window. The results showed that the window with a configuration of Dx = Dy = 5 mm (where Dx and Dy represent the horizontal and vertical pitches, respectively, between two adjacent solar optics) achieved the lowest U-value (2.566 W/m2·K). This U-value is slightly lower than that of the original window design, which has a U-value of 2.575 W/m2·K. The original window configuration with Dx = Dy = 1.77 mm produces the highest power output. Specifically, it generates 499.25 Wh/m2 on a typical sunny day in winter and 162.73 Wh/m2 on a typical sunny day in summer. However, it exhibits the lowest transmittance (14.6 % on a typical sunny day in winter and 25.2 % on a typical sunny day in summer, respectively), indicating that it is more suitable for buildings with a higher window-to-wall ratio to ensure an adequate amount of natural light. For buildings with a lower window-to-wall ratio, the CCPC-PV window should be designed with a larger horizontal pitch, such as 15 mm and 30 mm, to meet indoor illuminance requirements while also providing enhanced thermal performance and additional power output.

Taurodontic teeth in cone beam computed tomography: pictorial review

Objective: Taurodontism is a developmental disorder with enlargement of the body of the tooth and lack of cervical constriction, which results in a large pulp chamber and small roots with the apical displacement of furcation. Taurodontism exists in deciduous, and definitive unilateral, and bilateral teeth. We found that taurodontism was also described in 67 syndromes. We proposed a review of the open access literature on taurodontism, a new clinical classification of taurodontic teeth with illustrations from free open access literature, and from our case serie of 15 patients.&#x0D; Material and methods: We performed a systematic search for articles with free full text about taurodontism. The search was performed by one observer in PubMed database. We found 168 articles, and after application of inclusion/exclusion criteria we finally selected 136 articles for the review.&#x0D; Results: we provided 34 figures of taurodontic teeth related to: 1) Unilateral mandibular first premolar, 2) Unilateral mandibular second premolar, 3) Bilateral mandibular first and second premolar, 4) Bilateral upper maxillary first premolars, 5) Bilateral mandibular second molars, 6) Bilateral upper maxillary second premolar and left first molar, 7) Bilateral upper maxillary third molars, 8) Bilateral upper maxillary first and second molars, 9) Bilateral upper maxillary first, second, and third molars, 10) Bilateral upper maxillary molars (third molars, second, and first left upper molars), and mandibular molars (first right, and left mandibular molars, right third molar), 11) Bilateral upper maxillary molars (first, second, third right, and left upper molars), and mandibular molars, 12) Unilateral first mandibular premolar with cleft, 13) Bilateral molars of the mandible and the upper maxilla (adolescent patient who received chemotherapy at the age of 3-years-old to treat retinoblastoma), 14) Unilateral first maxillary molar (Treacher-Collins syndrome).&#x0D; Conclusions: We proposed a new clinical classification of taurodontic teeth based on hypo-, meso-, and hypertaurodontism, and on different types of deciduous, and definitive teeth (42 boxes). We were first to provide free reference images for: 1) upper maxillary second premolar hypertaurodontism, 2) mandibular second premolar mesotaurodontism, 3) upper maxillary third molar meso-and hypertaurodontism, 4) mandibular first molar hypotaurodontism, 5) mandibular third molar mesotaurodontism. We were also first to freely illustrate taurodontism related with chemotherapy, cleft palate patients, and Treacher-Collins syndrome.

Generation of New Aerosol Particles and Their Evolution in Atmospheric Air: Results of Experiments in a Large Aerosol Chamber of RPA Typhoon

—The results of experiments in the Large Aerosol Chamber of RPA Typhoon revealed the appearance of new aerosol particles larger than 15 nm in an aerosol-free volume of atmospheric air isolated from the external environment in darkness 20 min after the air purification. The generation of new particles is associated with the possible presence of precursor gases in the atmospheric air, which, under the influence of cosmic rays penetrating into the chamber, turn into aerosols. The experimentally observed evolution (over several days) of the size spectrum of the resulting particles shows that the generation of new aerosol particles lasts no more than 20 hours. During the evolution, the particles become larger and reach more than 100 nm size. After repeated purification of the air inside the chamber with the removal of newly generated aerosols, no new particles were detected for 10 days.

Библейская сцена «Ревекка» в контексте творческой биографии Сезара Франка

The article examines a large work composed by César Franck in 1881 and practically unexplored in Russian musicology — Rébecca (1881, world premiere in 1883), subtitled by the composer as “a biblical scene for soloists, chorus and orchestra”. The publication conveys a particular polemical pathos, because references to Rébecca in musicological literature in Russia and in other countries, until recently, had always been accompanied by factual inaccuracies. According to Vincent d’Indy’s periodization, the large-scale compositions of his teacher pertaining to the genre of cantata and oratorio (Ruth, Rédemption, and Les Béatitudes) mark the beginning of a new stage in the composer’s artistic biography. The early 1880s — the time of the creation of Rébecca — undoubtedly presents a turning point in Franck’s life: during the last decade of his life he would create masterpieces in almost all the genres to which he will turn to (these include symphonic poems, large chamber ensembles, piano, organ cycles, finally the Symphony in D minor). The creation of Rébecca was accompanied by biographical circumstances, interpreted by some researchers as a “passionate episode” in Franck’s life. This problem is illuminated in the article with the support of evidence provided by French-speaking musicologists. Posing the question of why the biblical plot about Rebecca has attracted the composer at that time, the author touches upon the composer’s personal and worldview aspects. The characterization of the cultural situation of the era in which Franck lived and composed his music provides evidence that the aforementioned factors determined not only the choice of the plot, but also the peculiarities of the genre, composition and intonation drama of the analyzed composition.

Simulation of Large Span Chamber Stability: Hoek Brown and Point Safety Factor Optimization

Simulation of Large Span Chamber Stability: Hoek Brown and Point Safety Factor Optimization

Bipolar ionization rapidly inactivates real-world, airborne concentrations of infective respiratory viruses.

The SARS-CoV-2 (COVID-19) pandemic has highlighted the urgent need for strategies that rapidly inactivate airborne respiratory viruses and break the transmission cycle of indoor spaces. Air ions can reduce viable bacteria, mold, and virus counts, however, most studies use small test enclosures with target microbes and ion sources in close vicinity. To evaluate ion performance in real-world spaces, experiments were conducted in a large, room-size BSL-3 Chamber. Negative and positive ions were delivered simultaneously using a commercially available bipolar air ion device. The device housed Needle Point Bipolar ionization (NPBI) technology. Large chamber studies often use unrealistically high virus concentrations to ensure measurable virus is present at the trial end. However, excessively high viral concentrations bias air cleaning devices towards underperformance. Hence, devices that provide a substantial impact for protecting occupants in real-world spaces with real-world virus concentrations are often dismissed as poor performers. Herein, both real-world and excessive virus concentrations were studied using Influenza A and B, Human Respiratory Syncytial Virus (RSV), and the SARS-CoV-2 Alpha and Delta strains. The average ion concentrations ranged from 4,100 to 24,000 per polarity over 60-minute and 30-minute time trials. The reduction rate was considerably greater for trials that used real-world virus concentrations, reducing infectivity for Influenza A and B, RSV, and SARS-CoV-2 Delta by 88.3-99.98% in 30 minutes, whereas trials using in-excess concentrations showed 49.5-61.2% in 30 minutes. These findings strongly support the addition of NPBI ion technology to building management strategies aimed to protect occupants from contracting and spreading infective respiratory viruses indoors.

Limit analysis on roof failure mechanism of tunnels subjected to sequential excavations

Compared to traditional full-face excavation methods, sequential excavation methods (SEM), such as central diaphragm (CD) and sidewall drift (SD) methods, can significantly reduce rock disturbance and minimize the extent of roof failure in tunnel crowns. Therefore, they are particularly suitable for tunnel projects in weak rock formations and large cross-sectional underground chambers. This paper presents a kinematic approach to predict the roof failure mechanism of tunnels excavated using the CD method. The collapse blocks at the top are influenced by excavation steps and initial in-situ stresses, and the direction of their failure velocity field is typically non-vertical, posing challenges for limit analysis applications. To address this, a tilted velocity field for the collapse failure of the tunnel crown in the CD method is constructed based on the initial normal stress distribution along the tunnel’s top contour, obtaining an upper bound solution for tunnel collapse failure. The proposed method is compared with the full-face excavation method, demonstrating the superiority of the CD method over the full-section method. The rationality of the proposed tilted velocity field mechanism is verified through numerical validation using finite difference methods. Building upon the upper bound solution, safety assessment indicators for tunnels excavated using the CD method, namely allowable rock stress release and safety factor, are proposed. Furthermore, we extend this method to analyze the roof failure mechanism in tunnels constructed using the SD method and confirm its effectiveness through comparison with FDM analysis. Theoretical analysis and numerical validation both indicate that sequential excavation methods can significantly reduce the potential collapse range at the top and improve the safety of tunnel construction.