A critical review of acoustic modeling and research on building façade

2021 ◽  
pp. 1351010X2110227
Author(s):  
Zhongyu Hu ◽  
Tarek Zayed ◽  
Li Cheng

Noise pollution has been impacting negatively on living comfort and working environment for a long time. Acoustic treatment on building façade is one of the effective means to tackle this issue. Numerous articles were published over the past decades to address the acoustic related problems of building façade. However, a systematic review of the research development on façade acoustic technology is lacking. Therefore, this paper examines the published research articles from seven selected journals, in terms of the annual number of articles, citation counts, co-authorships, research locations, and keywords. The analyses show that interest in façade acoustics increased during the last two decades. Researchers from Europe and areas with a high density of tall buildings made significant contributions to this development. Based on keyword analysis, articles are categorized into three groups. These include sound insulation studies, studies on the effect of façade on street noise, and noise reduction techniques. The surveyed research topics comprise numerical modeling, experimental studies, ISO standard development, and analyses on annoyance level. Potential future directions are presented based on a summary of the limitations of the existing research. This paper offers researchers and engineers an in-depth understanding of the state-of-the-art of the current façade acoustic research. Additionally, potential future directions are identified based on the findings and limitations of the previous studies.

Author(s):  
Zoya Veselovska ◽  
Nataliia Veselovska

The problem of studying the prеvalencе of allergic diseases of the eye and the search for new approaches and effective means to correct this condition does not lose its relevance. The presented data on the state of profound biochemical studies of the tear film in allergic conditions justify the expediency of the use of eye drops of a new generation. As a result of experimental studies on the effect on the lipid layer ectoine was discovered the mechanism of its therapeutic action. This paper presents compelling evidence that new eye drops based on natural molecules ectoine which are able to restore and maintain the functional state of the lipid layer of the tear film in the pharmacotherapy of аllergic diseases of anterior surface of the eye. The analyzes of multiple experimental data revealed the clear evidence of mechanisms of action on the eye and the first clinical experience with a new pharmacological agent testifies to its strong anti-inflammatory and regenerative effect due to the stabilization of the lipid layer of the tear film and the protection of the front surface of the eye tissue from the hyperosmolarity. It was confirmed by the subjective and objective reducing eye irritation and dryness in reducing itching and burning from the conjunctiva, to improve the moisture level of the surface of the eye, to reduce discomfort of the eyes. The drug can be used in children older than 2 years and adults, when wearing contact lenses, ophthalmic surgery and after an eye injury. Based on this, it can be conclude that the appearance in the arsenal of new-generation antiallergic eye drops (EYE-t) with sufficient efficacy and safety profile can be regarded as a promising alternative approach to the treatment of allergic and inflammatory eye diseases.


1984 ◽  
Vol 345 (0) ◽  
pp. 218-225 ◽  
Author(s):  
MASAHITO YASUOKA ◽  
HIDEKI TACHIBANA ◽  
HIROSHI TANAKA ◽  
AKIHIRO TAMURA

2020 ◽  
Vol 11 (3) ◽  
Author(s):  
V. V. Lomaha ◽  
O. Yu. Tsapko ◽  
Yu. V. Tsapko ◽  
O. P. Bondarenko

Reducing the fire prevention of timber is not only an economic task, but also has a social and environmental focus. From economic, technological and environmental perspective, an important problem in ensuring the viability and safe operation of construction sites is the development of fire-retardant coatings for wooden structures. The construction is increasingly looking for new highly effective means of fire protection of wood and wood products which should not only ensure the standardized fire resistance of wood, but also to maintain its operational parameters to solve environmental safety and durability. Studies of the effect of the radiation panel on the ignition of the wood sample have set the parameters of the flame ignition, which makes it possible to influence this process. It is proved that they consist in the formation of a layer of organic material on the surface, which provides heating to a critical temperature, when the intensive decomposition of the material begins with the release of the required amount of combustible gases and their ignition. This makes it possible to determine the effect of fire protection and the properties of protective compositions on the process of slowing down the rate of burning of wood. Experimental studies have confirmed that the untreated sample of wood, under the thermal action of the radiation panel has taken up, the flames spread over the entire surface, which led to its combustion. The application of a fire retardant varnish under the influence of temperature leads to a layer of foam coke and inhibition of heat transfer of high-temperature flame to the material and its ignition. Thanks to this, it became possible to determine the conditions for changing the parameters of combustion and braking during fire protection of wood, by forming a barrier for thermal conductivity. Thus, there is reason to argue for the possibility of directional control of the processes of fire protection of wood by the use of fireproof coatings that can form a protective layer on the surface of the material, which slows down the rate of burning of wood.


Author(s):  
E. I. Marukovich ◽  
E. B. Demchenko

The analysis of the performed researches has shown that the offered calculation technique is an effective means of management of formation process in casting. The found dependences and experimental data allow to calculate the specific value of the exactм heat flux in a given range of technological parameters obtained during a series of successful experiments for a particular casting method.Having the results of studies of the temperature regime of the mold during casting of a certain size and profile, it is possible to calculate the thermal state of the mold for the same casting process, but for the production of castings of any other size and profile.Having a certain amount of information on the temperature regime of the mold at different casting methods, you can use the solutions obtained to become the owner of a database containing the necessary information for solving the problems of solidification of the casting. In the subsequent design of equipment and equipment there is no need for additional experimental studies and analysis of the results.


Author(s):  
E. Fanina

A set of experimental studies is carried out to determine the acoustic characteristics of three-dimensional panels of fixed thickness made of carbon-based composite material installed in the opening between the reverberation chambers. Sound insulation indices are determined when they are excited by a diffuse sound field in wide frequency ranges. The reverberation time in model chambers with different partition configurations is calculated. The optimal configuration of the partition with pyramidal cells to reduce the reverberation time in the rooms is determined. The use of graphite in the form of thin membrane applied to various surfaces can significantly reduce the sound pressure levels in the room and increase the sound insulation indices of air noise. In addition to thin membrane, graphite can be used as an additive in composite materials for sound insulation purposes. It is shown that the characteristics of such panels are quite universal. The measured acoustic characteristics of composite panels are compared with similar characteristics of traditional materials. It is determined that the composition belongs to the I group of fire-retardant efficiency and can be recommended for use as a fire-retardant material. The developed acoustic material is an effective absorbing agent that solves problems in architectural acoustics, echo cancellation in construction and architecture. Similar to metamaterials, natural and artificial graphites allow to solve these problems with small volumes and masses using simple and inexpensive technologies.


NANO ◽  
2009 ◽  
Vol 04 (06) ◽  
pp. 325-338 ◽  
Author(s):  
PAWAN TYAGI

Molecular spin devices (MSDs) are the most promising candidate for futuristic quantum computation, having potential to resolve spin scattering issue which compromise the utility of conventional spin devices. The MSDs have been extensively reviewed from the view points of device physics and the application of target molecules, such as single molecular magnets. Fabrication of a competent MSD still remains an intractable task. In this review, we first describe the experimental studies where spin state of molecule and/or electrode affected the device transport, especially under magnetic field. Then, we correlated the number of theoretical and experimental results from various domains of nanomagnetism to highlight the scope and future directions panoramically. Finally, the key designs of various MSDs, including our recently developed multilayer edge molecular electrode, have been discussed. A multilayer edge molecular electrode, prepared by bridging the molecular clusters on the exposed edges of a customized ferromagnet–insulator–ferromagnet junction, can be a promising platform for testing the variety of molecular magnets.


2020 ◽  
Vol 17 (1) ◽  
pp. 52-61 ◽  
Author(s):  
Paddy C. Dempsey ◽  
Chuck E. Matthews ◽  
S. Ghazaleh Dashti ◽  
Aiden R. Doherty ◽  
Audrey Bergouignan ◽  
...  

Background: Recent updates to physical activity guidelines highlight the importance of reducing sedentary time. However, at present, only general recommendations are possible (ie, “Sit less, move more”). There remains a need to investigate the strength, temporality, specificity, and dose–response nature of sedentary behavior associations with chronic disease, along with potential underlying mechanisms. Methods: Stemming from a recent research workshop organized by the Sedentary Behavior Council themed “Sedentary behaviour mechanisms—biological and behavioural pathways linking sitting to adverse health outcomes,” this paper (1) discusses existing challenges and scientific discussions within this advancing area of science, (2) highlights and discusses emerging areas of interest, and (3) points to potential future directions. Results: A brief knowledge update is provided, reflecting upon current and evolving thinking/discussions, and the rapid accumulation of new evidence linking sedentary behavior to chronic disease. Research “action points” are made at the end of each section—spanning from measurement systems and analytic methods, genetic epidemiology, causal mediation, and experimental studies to biological and behavioral determinants and mechanisms. Conclusion: A better understanding of whether and how sedentary behavior is causally related to chronic disease will allow for more meaningful conclusions in the future and assist in refining clinical and public health policies/recommendations.


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