Comparative analysis of cooling energy performance between water-cooled VRF and conventional AHU systems in a commercial building

2020 ◽  
Vol 170 ◽  
pp. 114992 ◽  
Author(s):  
Byeongmo Seo ◽  
Yeo Beom Yoon ◽  
Byeong Ho Yu ◽  
Soolyeon Cho ◽  
Kwang Ho Lee
2018 ◽  
Vol 15 (3) ◽  
pp. 273-279
Author(s):  
V. M. Malov ◽  
A. V. Zolotarev ◽  
E. B. Eroshevskaya ◽  
I. V. Malov ◽  
A. E. Gorbunov

Objective:Comparative analysis of the results of phacoemulsification (FEC) with the use of developed and classic technologies for fragmentation of the lens nucleus in patients with pseudoexfoliation syndrome (PES).Patients and methods.The proposed technology is gentle crushing of the lens nucleus in patients with PES, you can reduce the pressure on the fibers of the zonule, the probability of damage to the ligaments and posterior capsule of the lens based on the use of phacofragmentation original design. To determine the radius of curvature of the working part of the tool a morphometrical measurement of the curvature of the equatorial zone of the lens cores removed during extracapsular and intracapsular cataract extraction in patients with PEX subluxation of the lens was carried out. A comparative analysis of the operation and the results of surgical treatment of cataract in patients with PEX with the use of the proposed (n = 58) and standard (n = 56) technologies of the nucleus fragmentation in phacoemulsification was made. The following ultrasound parameters were estimated: the average capacity in % (AVEUS), the average values of the absolute time ultrasound (APT) and average values of effective (EPT) time of ultrasound, in seconds, during phacoemulsification; structural-morphological changes in the posterior epithelium of the cornea according to the endothelial microscopy; the frequency and nature of complications, the visual acuity.Results.Morphometry of the lens nuclei in patients with pseudoexfoliation syndrome allowed to determine the average radius of curvature of the nucleus equator, which is made up 2.89 ± 0.14 mm, according to the performance curve of the Gauss — 2.895– 3.530 mm. These data are taken into account when selecting the radius of curvature of the working part of phacofragmentation (the radius of curvature of 3.0 mm) used with FEC in patients with PES (Patent RU152761 from 25.05.2015). The proposed chopper due to the conformity of the working part curvature of the tool and the Equatorial zone of cataract kernel can reliably capture and grind it, thus eliminating excessive pressure on the ligaments of the crystalline lens in patients with PES. Developed technology contributes to significantly reduction of the energy performance of ultrasound: AVEUS — 2.64–10.00 %; APT — 3.38–14.00 %; EPT — on 3.76– 16.00 % by 6.76 % in patients with different of the lens nucleus density degree, decrease operative and postoperative complications twice, 1.5 times less cell loss back the corneal epithelium. Visual acuity without correction from the first days after surgery was higher than 0.5 (average of 0.70 ± 0.05) in all the patients and increased to an average of 0.91 ± 0.01 within 12 months in patients of the main and 0.85 ± 0.02 — control groups.Conclusion.The developed technology of fragmentation of the lens nucleus reduces the time of phacoemulsification, reduces the ultrasound load, causes a smaller loss of cells at the back of the corneal epithelium, reduces the possible complications of the iris and ciliary body, which increases the efficiency of surgical treatment of cataract in patients with PEX.


2021 ◽  
Author(s):  
◽  
Chi-Yao Hsu

<p>The focus of this research is the concept of the 'Performance Sketch' tool. This is to use detailed simulation software to calculate (plausible) energy performance of designs quickly. Analogous to the Architectural Sketch the Performance Sketch uses high quality tools (detailed simulation) to create an accurate, but simple representation of the essential properties of a building, as opposed to a detailed representation. The aim of this research is to assess the consistency between the predictions produced by performance sketch design tools and the calculations produced by detailed design tools. The Lawrence Berkeley National Laboratory’s (LBNL) computer software COMFEN (COMmercial FENestration) is a performance sketch tool. It makes the power of the complex detailed design simulation package EnergyPlus available in the very early stages of the design process. It uses a single zone, single external façade EnergyPlus model to explore the costs and benefits of alternate façade designs. The hypothesis tested is that the COMFEN (single-zone) energy performance calculation method is plausible for early design analyses. It evaluates the performance sketch approach from three different points of view: first, COMFEN was introduced to various practitioners in the building industry to gather use-case feedback on the performance sketch approach. A list of specifications for performance sketch design tools was developed based on these use-cases. Second, it examines whether the optimum façade identified by COMFEN creates the optimum performance complex building when this optimum façade is incorporated into detailed building models. Finally, refinements of the nature of the performance sketch based on this use-case feedback were tested in EnergyPlus. The thesis concludes by drawing together these three threads into an outline of a practitioner-based definition of an ideal performance sketch which has been tested in practical application.</p>


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