143 research outputs found
Hygrothermal Effects of Air Cavities Behind Claddings on Building Envelopes
Air cavity behind claddings within building envelope provides an approach to mitigating building moisture-related issues as well as improving the building?s thermal performance. However, studies in literature commonly assume the cavity air as still and thus neglect the influence of mixed convection on the performance of building envelope. In addition, the drying performance of the air cavities remains unknown, and commonly a rectangular unicellular cavity is improperly assumed to simplify the investigation of the hygrothermal performance of a cladding system. Moreover, the literature lacks a study of the effect of humid air in the air cavity on heat and mass transfer. Therefore, it necessitates advanced problem formulation and solving to comprehensively study the effects of air cavities behind claddings on the performance of building envelope. The specific objectives are to 1) investigate potential of self-drying siding with raised air cavities for building envelopes; 2) study the effects of the cavity depth in mixed convection of air cavity for building envelopes; 3) analyze the effects of humid air in an air cavity on mass and heat transfer with phase change at the wall. To achieve these objectives, firstly, this study redefines the drying potential of air cavity taking into account the air cavity depth related to the shape irregularity and the inlet and outlet uncertainties. Then the formulated problems of mixed convection of air cavities behind sidings are solved with a perturbation method and SIMPLER algorithm. The results show that the drying performance is found to be heavily dependent on the cavity depth. Further, increasing the ratio of the siding depth to the air cavity depth amplifies the cavity air?s velocity, temperature, and mass fraction at cavity walls, as well as the heat and mass transfer across cavities. Consequently, this study demonstrated that humid air with the phase change and the cavity depth have the significant effects on the hygrothermal performance of building envelopes. The outcome of this study provides valuable guidance on the thermal performance evaluation of air cavity and has the potential of improving the design of claddings for the overall hygrothermal performance of building envelope
Higher Education on Buildings: Case Study in the North Dakota Region
Because of the growing demand for local skilled professionals to improve the health, energy efficiency, and sustainability of residential and commercial buildings in North Dakota, this case study reports the current situation of higher education relating to buildings in the stateâs vicinity, including Minnesota, Montana, North Dakota, and South Dakota. In this region, 116 programs relating to buildings were found in 41 postsecondary institutions, and both their majors and courses were then studied with frequency lists. The frequency information was analyzed over nine sets of curriculum areas at both graduate and undergraduate levels for the four states. After the current state of buildings in North Dakota was investigated, strategies were then proposed to rectify current issues regarding higher education on buildings, including but not limited to forming a comprehensive and interdisciplinary program on buildings (e.g., architectural engineering), providing more graduate programs, developing more courses in areas that lack adequate coursework, and increasing student enrollment. These strategies will greatly promote the health, energy efficiency, and sustainability for new and existing buildings in the four-state region of Minnesota, Montana, North Dakota, and South Dakota
Ultrafast and Ultralight Network-Based Intelligent System for Real-time Diagnosis of Ear diseases in Any Devices
Traditional ear disease diagnosis heavily depends on experienced specialists
and specialized equipment, frequently resulting in misdiagnoses, treatment
delays, and financial burdens for some patients. Utilizing deep learning models
for efficient ear disease diagnosis has proven effective and affordable.
However, existing research overlooked model inference speed and parameter size
required for deployment. To tackle these challenges, we constructed a
large-scale dataset comprising eight ear disease categories and normal ear
canal samples from two hospitals. Inspired by ShuffleNetV2, we developed
Best-EarNet, an ultrafast and ultralight network enabling real-time ear disease
diagnosis. Best-EarNet incorporates the novel Local-Global Spatial Feature
Fusion Module which can capture global and local spatial information
simultaneously and guide the network to focus on crucial regions within feature
maps at various levels, mitigating low accuracy issues. Moreover, our network
uses multiple auxiliary classification heads for efficient parameter
optimization. With 0.77M parameters, Best-EarNet achieves an average frames per
second of 80 on CPU. Employing transfer learning and five-fold cross-validation
with 22,581 images from Hospital-1, the model achieves an impressive 95.23%
accuracy. External testing on 1,652 images from Hospital-2 validates its
performance, yielding 92.14% accuracy. Compared to state-of-the-art networks,
Best-EarNet establishes a new state-of-the-art (SOTA) in practical
applications. Most importantly, we developed an intelligent diagnosis system
called Ear Keeper, which can be deployed on common electronic devices. By
manipulating a compact electronic otoscope, users can perform comprehensive
scanning and diagnosis of the ear canal using real-time video. This study
provides a novel paradigm for ear endoscopy and other medical endoscopic image
recognition applications.Comment: This manuscript has been submitted to Neural Network
The possible mechanisms of ferroptosis in sepsis-associated acquired weakness
Sepsis is a life-threatening organ dysfunction caused by a dysregulated host response to infection, and its morbidity and mortality rates are increasing annually. It is an independent risk factor for intensive care unit-acquired weakness (ICU-AW), which is a common complication of patients in ICU. This situation is also known as sepsis-associated acquired weakness (SAW), and it can be a complication in more than 60% of patients with sepsis. The outcomes of SAW are often prolonged mechanical ventilation, extended hospital stays, and increased morbidity and mortality of patients in ICUs. The pathogenesis of SAW is unclear, and an effective clinical treatment is not available. Ferroptosis is an iron-dependent type of cell death with unique morphological, biochemical, and genetic features. Unlike other forms of cell death such as autophagy, apoptosis, and necrosis, ferroptosis is primarily driven by lipid peroxidation. Cells undergo ferroptosis during sepsis, which further enhances the inflammatory response. This process leads to increased cell death, as well as multi-organ dysfunction and failure. Recently, there have been sporadic reports suggesting that SAW is associated with ferroptosis, but the exact pathophysiological mechanisms remain unclear. Therefore, we reviewed the possible pathogenesis of ferroptosis that leads to SAW and offer new strategies to prevent and treat SAW
The α1âadrenergic receptor is involved in hepcidin upregulation induced by adrenaline and norepinephrine via the STAT3 pathway
Elevated body iron stores are associated with hypertension progression, while hypertension is associated with elevated plasma catecholamine levels in patients. However, there is a gap in our understanding of the connection between catecholamines and iron regulation. Hepcidin is a key ironâregulatory hormone, which maintains body iron balance. In the present study, we investigated the effects of adrenaline (AD) and norepinephrine (NE) on hepatic hepcidin regulation. Mice were treated with AD, NE, phenylephrine (PE, α1âadrenergic receptor agonist), prazosin (PZ, α1âadrenergic receptor antagonist), and/or propranolol (Pro, ÎČâadrenergic receptor antagonist). The levels of hepcidin, as well as signal transducer and activator of transcription 3 (STAT3), ferroportin 1 (FPN1), and ferritinâlight (FtâL) protein in the liver or spleen, were assessed. Six hours after AD, NE, or PE treatment, hepatic hepcidin mRNA levels increased. Pretreatment with PZ, but not Pro, abolished the effects of AD or NE on STAT3 phosphorylation and hepatic hepcidin expression. When mice were treated with AD or NE continuously for 7 days, an increase in hepatic hepcidin mRNA levels and serum hepcidin concentration was also observed. Meanwhile, the expected downstream effects of elevated hepcidin, namely decreased FPN1 expression and increased FtâL protein and nonâheme iron concentrations in the spleen, were observed after the continuous AD or NE treatments. Taken together, we found that AD or NE increase hepatic hepcidin expression via the α1âadrenergic receptor and STAT3 pathways in mice. The elevated hepatic hepcidin decreased FPN1 levels in the spleen, likely causing the increased iron accumulation in the spleen
HI content of massive red spiral galaxies observed by FAST
A sample of 279 massive red spirals was selected optically by Guo et al.
(2020), among which 166 galaxies have been observed by the ALFALFA survey. In
this work, we observe HI content of the rest 113 massive red spiral galaxies
using the Five-hundred-meter Aperture Spherical radio Telescope (FAST). 75 of
the 113 galaxies have HI detection with a signal-to-noise ratio (S/N) greater
than 4.7. Compared with the red spirals in the same sample that have been
observed by the ALFALFA survey, galaxies observed by FAST have on average a
higher S/N, and reach to a lower HI mass. To investigate why many red spirals
contain a significant amount of HI mass, we check color profiles of the massive
red spirals using images observed by the DESI Legacy Imaging Surveys. We find
that galaxies with HI detection have bluer outer disks than the galaxies
without HI detection, for both ALFALFA and FAST samples. For galaxies with HI
detection, there exists a clear correlation between galaxy HI mass and g-r
color at outer radius: galaxies with higher HI masses have bluer outer disks.
The results indicate that optically selected massive red spirals are not fully
quenched, and the HI gas observed in many of the galaxies may exist in their
outer blue disks.Comment: 11 pages, 9 figures, accepted by MNRAS; Table 1 is available in the
source file
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