Search Results (149)

Molds readily grow on wet books, documents, and other library materials where they ruin them chemically, mechanically, and aesthetically. Poor maintenance of libraries, failures of Heating, Ventilation, and Air Conditioning (HVAC) systems, roof leaks, and storm damage leading to flooding can all result in accelerated fungal growth. Moreover, when fungal spores are present at high concentrations in the air, they can be linked to severe respiratory conditions and possibly to other adverse health effects in humans. Climate change and the accompanying storms and floods are making the dual potential of fungi to biodegrade library holdings and harm human health more common. This essay is intended for microbiologists without much background in mycology who are called in to help librarians who are dealing with mold outbreaks in libraries. Our goal is to demystify aspects of fungal taxonomy, morphology, and nomenclature while also recommending guidelines for minimizing mold contamination in library collections. Full article

Perfusable microvasculature is critical for advancing in vitro tissue models, particularly for neural applications where limited diffusion impairs organoid growth and fails to replicate neurovascular function. This study presents a versatile fabrication platform that integrates mesh-driven design, two-photon lithography (TPL), and modular interfacing to create multi-material, perfusable 3D microvasculatures. Various 2D and 3D capillary paths were test-printed using both polygonal and lattice support strategies. A double-layered capillary scaffold based on the Hilbert curve was used for comparative materials testing. Methods for printing rigid (OrmoComp), moderately stiff hydrogel (polyethylene glycol diacrylate, PEGDA 700), and soft elastomeric (photocurable polydimethylsiloxane, PDMS) materials were developed and evaluated. Cone support structures enabled high-fidelity printing of the softer materials. A compact heat-shrink tubing interface provided leak-free perfusion without bulky fittings. Physiologically relevant flow velocities and Dextran diffusion through the scaffold were successfully demonstrated. Cytocompatibility assays confirmed that all TPL-printed scaffold materials supported human neural stem cell viability. Among peripheral components, lids fabricated via fused deposition modeling designed to hold microfluidic needle adapters exhibited good biocompatibility, while those made using liquid crystal display-based photopolymerization showed significant cytotoxicity despite indirect exposure. Overall, this platform enables creation of multi-material microvascular systems facilitated by TPL technology for complex, 3D neurovascular modeling, blood–brain barrier studies, and integration into vascularized organ-on-chip applications. Full article

We present a thoughtfully curated collection of laboratory demonstrations, simulations, and straightforward experiments that explore the fundamental processes underlying greenhouse effect (GHE), climate, atmospheric physics, and Earth’s energy balance. The objective is to connect theory and practice in climate science education and address common student misconceptions. The activities are structured to guide students in constructing simple models of Earth’s radiative equilibrium. Experimental activities cover essential concepts such as the electromagnetic spectrum, radiation–matter interaction, thermal radiation, and energy balance. Physical experiments include visualizing the spectrum with a homemade spectroscope and an infrared (IR) thermal camera, studying absorption and selective transparency when light interacts with different materials, measuring the power emitted by a heated filament, and using simple models, such as black and white discs or a leaking bucket, to understand radiative equilibrium and steady states. This sequence was piloted in a physics education laboratory class with 85 university students enrolled in mathematics and physics courses for future teachers. To assess comprehension improvement, pre- and post-tests involving the production of drawings and explanations related to the GHE were administered to all students. These activities also aim to promote critical thinking and counter climate misinformation and denial. The results showed a significant improvement in understanding fundamental GHE concepts. Additionally, a small subset of students was interviewed to explore the psychological and social dimensions related to the climate crisis. Full article

With the introduction of the “dual carbon” strategy, public attention to green energy has surged, leading to a notable increase in the demand for natural gas. Consequently, the storage and transportation of liquefied natural gas (LNG) have emerged as critical aspects to ensure its safe and cost-effective utilization. For onshore LNG storage, LNG storage tanks play a pivotal role. However, in extreme scenarios such as fires, these tanks may be exposed to radiant heat, which not only jeopardizes their structural integrity but could also result in LNG leaks, triggering severe safety incidents and environmental disasters. Against this backdrop, this study delves into the evaporation characteristics of large-scale LNG storage tanks under fire radiation conditions. Given the unique properties of LNG and the similarity between the bubble-point lines and heat exchange curves of nitrogen and LNG, liquid nitrogen is employed as a substitute for LNG in experimental investigations to observe evaporation behaviors. Furthermore, the FLUENT 2022R1 software is utilized to conduct numerical simulations on a 160,000-cubic-meter LNG storage tank, aiming to model the intricate process of internal evaporation and the impact of environmental factors. The findings of this research aim to furnish a scientific basis for enhancing the storage safety of large-scale LNG storage tanks. Full article

This paper presents the design of a fault detection system (FDD) based on principal component analysis (PCA) to detect faults in the transient state of distillation processes. The FDD system detects faults due to changes in calorific power and pressure leaks that can occur during the heating of the mixture to be distilled (transient), mainly affecting the quality of the distilled product and the safety of the process and operators. The proposed FDD system is based on PCA with a T2 Hotelling statistical approach, considering data from a real distillation pilot plant process. The FDD system is evaluated with two fault scenarios, performing power changes and pressure leaks in the pilot plant reboiler during the transient state. Finally, the results of the FDD system are analyzed using Accuracy, Precision, Recall, and Specificity metrics to validate its performance. Full article

In the context of increasing climate variability and extreme weather, chilled water systems face mounting challenges due to amplified heating and cooling demands and prevalent pipe leakages. Such leakages reduce system lifespan, raise maintenance costs, and degrade operational efficiency. To overcome the limitations of current methods, such as insufficient interpretability and computational complexity in leak localization, this paper proposes a novel leakage diagnosis and localization scheme based on pressure variation rate analysis in closed chilled water pipeline networks. Hydraulic models under both normal and leakage conditions are established and experimentally validated. Work conditions under various leakage points and flow rates were simulated, and the results reveal that pressure variation rates systematically increase with the leakage flow rate and vary with the distance from the leakage point. Specifically, when a leakage flow rate reaches 20% of the total rated flow, the pressure variation rate is 12.27% at the water supply side of the leaking branch and 20.27% at the return side. Furthermore, other monitoring points can be categorized into three distinct levels with variation rates ranging from approximately 3.36% to 19.65%. Overall, as the leakage flow increases from 2% to 20% of the design flow, the maximum pressure variation rate rises from 0.411% to 20.27%. A threshold of 3% for this novel leakage diagnosis and localization scheme is used for prompt leakage detection. This scheme not only enhances leak localization accuracy but also contributes to more efficient and reliable system operation under the pressure imposed by climate change. Full article

The peak load boiler (PLB) is a heat production facility that uses SA178 Gr. A and SA516 Gr. 70 low-carbon steels as tube and plate materials, respectively. Recently, failures were frequently observed near plugged tubes due to water leakage, raising concerns about corrosion mechanisms and their impact on tube durability. This work investigates the corrosion failure mechanisms using a combination of endoscopy, ultrasound inspection, oxide scale analysis (X-ray diffraction), chemical analysis (ion chromatography and inductively coupled plasma mass spectrometry), and computational fluid dynamics simulations. The undamaged tube near the leaked tube exhibited oxide scale levels comparable to those directly affected. Surface examinations revealed gas-side pits indicative of localized corrosion, while oxide scales were predominantly composed of iron oxides formed under humid conditions and sodium compounds derived from boiler water. Analysis of the leaked water revealed its mixture with combustion gases, forming an acidic, chloride-rich environment that significantly accelerates corrosion. Computational fluid dynamics simulations demonstrated that leaked water vapor facilitated the condensation of acidic ions near affected tubes, promoting dew point corrosion. These phenomena, driven by localized condensation and chemical concentration at the dew point temperature, exacerbate material degradation, emphasizing the importance of targeted prevention strategies. Full article

Steel–concrete–steel (SCS) composite slabs are widely used in critical infrastructures such as nuclear power plants, where systematic performance evaluation through multiple criteria is crucial due to their safety functions. During their use, fires may occur due to fuel or gas leaks, leading to explosions. This article uses ABAQUS 2020 finite element software and combines the different advantages of the implicit heat transfer algorithm and explosion display algorithm to establish a numerical simulation method for dynamic analysis of SCS slab under explosion after fire. Based on different fire conditions and the propagation laws of explosion shock waves, some key dynamic indicators and failure modes of the slab were studied. The results reveal progressive damage mechanisms with increasing fire duration, characterized by expanding damage areas, significant stress fluctuations, and increasing displacement rates. Additionally, the fire surface shows greater vulnerability than the back fire surface. The results provide multiple evaluation criteria for assessing structural performance, including temperature distribution, stress evolution, and damage patterns, which can support engineering decision-making in structural safety management. Full article

Background/Objectives: Mask-wearing-induced discomfort often leads to unconscious loosening of the mask to relieve the discomfort, thereby compromising protective efficacy. This study investigated how leakage flows affect mask-associated thermoregulation and vapor trapping to inform better mask designs. An integrated ambience–mask–face–airway model with various mask-wearing misfits was developed. Methods: The transient warming/cooling effects, thermal buoyancy force, tissue heat generation, vapor phase change, and fluid/heat/mass transfer through a porous medium were considered in this model, which was validated using Schlieren imaging, a thermal camera, and velocity/temperature measurements. Leakages from the top and side of the mask were analyzed in comparison to a no-leak scenario under cyclic respiration conditions. Results: A significant inverse relationship was observed between mask leakage and facial temperature/humidity. An equivalent impact from buoyancy forces and exhalation flow inertia was observed both experimentally and numerically, indicating a delicate balance between natural convection and forced convection, which is sensitive to leakage flows and critical in thermo-humidity regulation. For a given gap, the leakage fraction was not constant within one breathing cycle but constantly increased during exhalation. Persistently higher temperatures were found in the nose region throughout the breathing cycle in a sealed mask and were mitigated during inhalation when gaps were present. Vapor condensation occurred within the mask medium during exhalation in all mask-wearing cases. Conclusions: The thermal and vapor temporal variation profiles were sensitive to the location of the gap, highlighting the feasibility of leveraging temperature and relative humidity to test mask fit and quantify leakage fraction. Full article

The research on the thermal insulation performance of experimental systems in the liquid helium temperature range is relatively scarce. This paper presents the theoretical design and establishment of a liquid helium storage system for insulation research, consisting of a liquid helium Dewar, a daily boil-off rate test subsystem, and a helium recovery subsystem. The passive thermal insulation structure consisted of a multilayer insulation (MLI) system with hollow glass microspheres serving as spacers. Based on self-built data acquisition, experiments were conducted to investigate the liquid helium insulation characteristics of an experimental system. A theoretical thermal analysis of the Dewar was conducted, resulting in the derivation of an expression for the heat leak of the Dewar. The analysis indicates that the evaporation capacity from the liquid helium Dewar was significantly affected by the structure of the neck tube. The overall relative error between the simulated and experimental temperature distribution of the insulation layer is 14.3%, with a maximum error of 22.3%. The system had an average daily boil-off rate of 14.4%, a heat leakage of 7.5 W, and a heat flux of 2.254 W/m², while the effective thermal conductivity of the MLI with hollow glass microspheres was determined to be 2.887 × 10⁻⁴ W/(m·K). Furthermore, the apparent thermal conductivity between different layers of MLI significantly fluctuated with increasing temperature, ranging from a maximum of 5.342 × 10⁻⁴ W/(m·K) to a minimum of 1.721 × 10⁻⁴ W/(m·K). Full article

Hydrofluorocarbons (HFCs) are widely used in refrigeration, air conditioning, heat pumps (RACHP), and various other applications such as aerosols, fire extinguishers, foams, and solvents. Initially, HFCs were adopted as the primary substitutes for ozone-depleting substances (ODSs) regulated under the Montreal Protocol. However, many HFCs are potent greenhouse gases, and as such subject to a global phasedown under the provisions of the Kigali Amendment to the Montreal Protocol. Managing the refrigerant bank of ODSs and HFCs throughout the equipment’s lifecycle—referred to as Lifecycle Refrigerant Management (LRM)—presents a significant challenge but also a significant climate action opportunity. LRM includes the leak prevention, recovery, recycling, reclamation, and destruction (RRRD) of refrigerants. This study employed the GAINS modeling framework to assess the ozone and climate benefits of LRM. The findings indicated that implementing robust LRM practices during the use and end-of-life stages of RACHP equipment could reduce ODS emissions by approximately 5 kt ODP (Ozone Depletion Potential) between 2025 and 2040, and HFC and hydrochlorofluorocarbon (HCFC) emissions by about 39 Gt CO₂e between 2025 and 2050. The implementation of robust LRM measures in conjunction with the ongoing phasedown of HFCs under the Kigali Amendment can yield substantial additional climate benefits beyond those anticipated from the HFC phasedown alone. Full article

This paper introduces a novel thermoelectric generator (TEG)-powered Industrial Internet of Things (IIoT) device that addresses key limitations in the detection of steam leaks in industrial steam pipelines, particularly in steam traps. Existing solutions often rely on battery-powered or wired sensors, which are limited by high maintenance costs, short lifespans, or significant infrastructure investments. The proposed device operates without batteries, using waste heat to provide continuous power, and leverages LoRaWAN for long-range wireless communication, minimizing reliance on costly internal infrastructure. Additionally, the device integrates temperature differential (ΔT) and ultrasonic sensors with edge computing capabilities to enhance real-time leak detection and reduce dependency on cloud computing. By enabling precise, low-maintenance monitoring of steam systems in energy-intensive industries (e.g., petrochemical, pharmaceutical), this technology can significantly reduce energy losses, operational costs, and greenhouse gas emissions. Initial testing demonstrates the device’s ability to detect leaks accurately under varying industrial conditions, offering a robust, scalable solution for Industry 4.0 applications. Full article

In order to identify the leak source in complex heating pipeline networks, a timely and effective simulation of the leakage process was conducted. The open-source computational fluid dynamics software OpenFOAM 5.0 was combined with the PISO algorithm to simulate the pressure during the leakage in water supply networks, transforming the reverse source tracing problem into the solution of an adjoint equation. The validation of the transient adjoint equation for single-phase flow was completed through simulation, and the pressure wave change graph at the moment of the network leakage was solved, which was consistent with the experimental results. Using the open-source finite element analysis software OpenFOAM 5.0, the positioning accuracy of pipeline leak points can be controlled within the range from 92% to 96%. Based on the pressure wave change graph, the position of the leak source in the complex network was determined using the reverse source tracing method combined with the second correlation theory. The results show that the calculation speed of the PISO algorithm combined with the adjoint equation is significantly better than that of the individual SIMPLE and PISO algorithms, thereby proving the superiority of the adjoint method. Full article

Climate change stands out as a significant environmental issue on a global scale, with greenhouse gases being one of its primary drivers. The greenhouse gas process provides a critical framework for understanding the sources, emissions, and environmental impacts of these gases. This article presents an overview of the fundamental elements of the greenhouse gas process in the textile sector and discusses how it should be managed in line with sustainability goals. Carbon dioxide (CO₂), methane (CH₄), nitrous oxides (N₂O), and fluorinated gases are the most common greenhouse gases, each derived from different sources. The textile sector is particularly associated with high greenhouse gas emissions, especially in areas such as energy consumption, water usage, and waste management. Therefore, measurements taken in factories are crucial for identifying emission sources and developing reduction strategies. This article examines in detail the greenhouse gas emissions resulting from various activities at Kıvanç Textile. Energy consumption, particularly the emissions resulting from the fuels used in electricity and heating processes, is evaluated. Additionally, emissions from other important sources such as refrigerant gas leaks, waste management, and transportation are analyzed. The measurement process was carried out in accordance with national and international standards. The greenhouse gas inventory includes data on energy consumption, fuel consumption, refrigerant gas usage, transportation, production process management, and waste management throughout the factory. Based on these data, the total amount and sources of emissions were determined. This study presents a systematic method for calculating a company’s carbon footprint, with data collected in accordance with national and international standards. Such data can provide a reference point for other companies when making similar calculations. All of the businesses of the facility where the study was conducted were examined and calculations were made on a total of 1350 employees. As a result of the detailed study, Kıvanç Textile’s corporate carbon footprint for 2023 was calculated as a total of 68,746.86 tons ${\mathrm{C}\mathrm{O}}_2\mathrm{e}$. According to this data obtained, Kıvanç Textile emitted 50.92 tons of ${\mathrm{C}\mathrm{O}}_2\mathrm{e}$ greenhouse gases per employee. At the same time, it was determined that the production in 2023 was 4,427,082 tons and a greenhouse gas emission of 15.53 tons of ${\mathrm{C}\mathrm{O}}_2\mathrm{e}$ per production (ton) was calculated. This study also includes proposed strategies for reducing emissions. These strategies include energy efficiency measures, the use of renewable energy sources, waste reduction, and the adoption of efficient production processes. In conclusion, this article emphasizes the importance of efforts to measure and reduce greenhouse gas emissions in textile factories. Kıvanç Textile’s greenhouse gas measurements provide a fundamental reference for achieving sustainability goals in the sector. The data obtained will support the factory’s efforts to reduce its carbon footprint and minimize its environmental impacts. Full article

This study presents a comprehensive risk assessment of ammonia leaks, focusing on the quantitative modelling of hazardous area ranges, concentration dynamics, and thermal radiation effects under varying leakage scenarios using the ALOHA 5.4.7 software. The analysis involves two key scenarios: an ammonia gas leak and a pool fire, each modelled under distinct atmospheric conditions. For the gas leak scenario, ammonia concentrations were mapped across ERPG-defined hazard zones, ranging from low-level irritation zones (ERPG-1) to life-threatening exposure levels (ERPG-3), with maximum concentrations reaching 1500 ppm within a 110 m radius. The second scenario examined the impact of thermal radiation from a pool fire, identifying critical radiation zones where exposure to heat fluxes exceeding 10 kW.m⁻² could cause fatal outcomes within 12 m. Despite ALOHA’s strengths in modelling acute exposure risks and providing valuable input for emergency response planning, the study identifies several limitations, particularly regarding the long-term environmental and health impacts of chemical releases and the effects of varying meteorological conditions. These findings suggest that integrating ALOHA with advanced real-time monitoring and AI-based prediction systems could significantly improve its capacity to manage dynamic, rapidly evolving industrial hazards. Full article