Improving the Capacity and Performance of Air-Conditioning Screw Compressors

2006 ◽  
Author(s):  
Thomas Broglia ◽  
Matteo Iobbi ◽  
Nikola Stosic
Keyword(s):  
Air Conditioning ◽  
Screw Compressor ◽  
Standard Pattern ◽  
Collaborative Project ◽  
Compressor Design ◽  
Modelling Procedure ◽  
And Performance ◽  
Specific Duty ◽  
Optimisation Procedure ◽  
Better Than

Traditional compressor design methods make it very difficult to make significant improvements to screw compressors required for refrigeration and air conditioning applications. The principles which determine the optimum design of such machines are reviewed and, in some cases, redefined. These include rotor profiling, configuration and proportions, clearance distribution and bearing clearances and it is shown that there are conflicting requirements for them when attempting to obtain optimum performance. The best result can thus only be obtained by consideration of all the relevant parameters in an optimisation procedure, which leads to rotor designs that vary according to the specific duty of a machine, rather than follow a standard pattern An outline description is given of a process modelling procedure which has been developed to optimise the design of a compressor by the use of multi variable minimisation methods that take simultaneous account of all these parameters As a result of a collaborative project between industry and an academic institution, this procedure was applied to the design of a new refrigeration screw compressor, which was then built and tested. Its performance was then compared with that of the machine it was intended to replace. It is shown that the optimised design was up to 9% better than the original machine.

Application Fuzzy Logic System for Accurate Sheet Trim Shower Position

2019 ◽  
Vol 3 (1) ◽  
pp. 186-192
Author(s):  
Yudi Wibawa
Keyword(s):  
Fuzzy Logic ◽  
Fuzzy Logic Controller ◽  
Dc Motor ◽  
Automation System ◽  
Paper Making ◽  
System A ◽  
Accurate Position ◽  
And Performance ◽  
Better Than ◽  
Logic System

This paper aims to study for accurate sheet trim shower position for paper making process. An accurate position is required in an automation system. A mathematical model of DC motor is used to obtain a transfer function between shaft position and applied voltage. PID controller with Ziegler-Nichols and Hang-tuning rule and Fuzzy logic controller for controlling position accuracy are required. The result reference explains it that the FLC is better than other methods and performance characteristics also improve the control of DC motor.

scholarly journals Applicability and performance of EUCAST’s rapid antimicrobial susceptibility testing (RAST) on primarily sterile body fluids in blood culture bottles in laboratory routine with total lab automation

2021 ◽  
Author(s):  
Jasmin Kaur Jasuja ◽  
Stefan Zimmermann ◽  
Irene Burckhardt
Keyword(s):  
Blood Culture ◽  
Susceptibility Testing ◽  
Reference Method ◽  
Body Fluids ◽  
E Coli ◽  
Mueller Hinton ◽  
Mueller Hinton Agar ◽  
And Performance ◽  
Sterile Body Fluids ◽  
Better Than

AbstractOptimisation of microbiological diagnostics in primarily sterile body fluids is required. Our objective was to apply EUCAST’s RAST on primarily sterile body fluids in blood culture bottles with total lab automation (TLA) and to compare results to our reference method Vitek2 in order to report susceptibility results earlier. Positive blood culture bottles (BACTEC™ Aerobic/Anaerobic/PEDS) inoculated with primarily sterile body fluids were semi-automatically subcultured onto Columbia 5% SB agar, chocolate agar, MacConkey agar, Schaedler/KV agar and Mueller-Hinton agar. On latter, cefoxitin, ampicillin, vancomycin, piperacillin/tazobactam, meropenem and ciprofloxacin were added. After 6 h, subcultures and RAST were imaged and MALDI-TOF MS was performed. Zone sizes were digitally measured and interpreted following RAST breakpoints for blood cultures. MIC values were determined using Vitek2 panels. During a 1-year period, 197 Staphylococcus aureus, 91 Enterococcus spp., 38 Escherichia coli, 11 Klebsiella pneumoniae and 8 Pseudomonas aeruginosa were found. Categorical agreement between RAST and MIC was 96.5%. Comparison showed no very major errors, 2/7 (28.6%) and 1/7 (14.3%) of major errors for P. aeruginosa and meropenem and ciprofloxacin, 1/9 (11.1%) for K. pneumoniae and ciprofloxacin, 4/69 (7.0%) and 3/43 (5.8%) for Enterococcus spp. and vancomycin and ampicillin, respectively. Minor errors for P. aeruginosa and meropenem (1/8; 12.8%) and for E. coli and ciprofloxacin (2/29; 6.5%) were found. 30/550 RAST measurements were within area of technical uncertainty. RAST is applicable and performs well for primarily sterile body fluids in blood culture bottles, partially better than blood-based RAST. Official EUCAST evaluation is needed.

scholarly journals The Potential of Advanced Placement to Improve College Outcomes and Narrow Racial/Ethnic and Socioeconomic Disparities

2021 ◽  
pp. 1932202X2110186
Author(s):  
Sarah Fierberg Phillips ◽  
Brett Lane
Keyword(s):  
Advanced Placement ◽  
Low Income ◽  
Latino Students ◽  
Socioeconomic Disparities ◽  
Low Income Students ◽  
College Outcomes ◽  
Highly Educated ◽  
And Performance ◽  
Racial Ethnic ◽  
Better Than

The U.S. economy requires a highly educated workforce, yet too few black, Latino, and low-income students attend, persist, and graduate from college. The present study examines the college outcomes of participants in a model Advanced Placement® (AP) intervention to shed light on its effectiveness and determine whether improving AP participation and performance is a promising strategy for closing persistent racial/ethnic and socioeconomic disparities in college outcomes. Findings suggest the college outcomes of program participants are better than those of similar students statewide while also highlighting variation within and across subgroups. At the same time, they confirm that AP participation and performance predict college outcomes and suggest that improving AP participation and performance among low-income white, black, and Latino students could be a useful strategy for closing persistent racial/ethnic and socioeconomic disparities in college outcomes.

The closed-subpopulation method and estimation of population size from mark-recapture and ancillary data

2000 ◽  
Vol 78 (2) ◽  
pp. 320-326 ◽  
Author(s):  
Frank AM Tuyttens
Keyword(s):  
Population Size ◽  
Ancillary Data ◽  
Mark Recapture ◽  
Animal Populations ◽  
Accuracy And Precision ◽  
Population Size Estimates ◽  
Minimum Number ◽  
Flexible Framework ◽  
And Performance ◽  
Better Than

The algebraic relationships, underlying assumptions, and performance of the recently proposed closed-subpopulation method are compared with those of other commonly used methods for estimating the size of animal populations from mark-recapture records. In its basic format the closed-subpopulation method is similar to the Manly-Parr method and less restrictive than the Jolly-Seber method. Computer simulations indicate that the accuracy and precision of the population estimators generated by the basic closed-subpopulation method are almost comparable to those generated by the Jolly-Seber method, and generally better than those of the minimum-number-alive method. The performance of all these methods depends on the capture probability, the number of previous and subsequent trapping occasions, and whether the population is demographically closed or open. Violation of the assumption of equal catchability causes a negative bias that is more pronounced for the closed-subpopulation and Jolly-Seber estimators than for the minimum-number-alive. The closed-subpopulation method provides a simple and flexible framework for illustrating that the precision and accuracy of population-size estimates can be improved by incorporating evidence, other than mark-recapture data, of the presence of recognisable individuals in the population (from radiotelemetry, mortality records, or sightings, for example) and by exploiting specific characteristics of the population concerned.

Study on the Preparation and Performance of Carboxymethyl Chitosan Calcium and Carboxymethyl Chitosan Zinc Composite Materials

2016 ◽  
Vol 852 ◽  
pp. 1319-1324 ◽  
Author(s):  
Jing Li ◽  
Chang Ping Wei ◽  
Feng Ming Wang ◽  
Li Dan Dong ◽  
Shuang Sun ◽  
...  
Keyword(s):  
Chloride Solution ◽  
Water Solubility ◽  
Chloroacetic Acid ◽  
Sem Analysis ◽  
Carboxymethyl Chitosan ◽  
X Ray Diffraction ◽  
Test Study ◽  
Alkaline Conditions ◽  
And Performance ◽  
Better Than

In this paper,under alkaline conditions,with chloroacetic acid to modify chitosan,obtained carboxymethyl chitosan. At pH<7 conditions,the obtained carboxymethy chitosan respectively were reacted with calcium chloride solution,zinc chloride solution,after fully reacted,obtained carboxymethyl chitosan calcium and carboxymethyl chitosan zinc .Through infrared spectrum,X-ray diffraction and scanning electron microscopy (sem) analysis means,the structure of the products were characterized.Through the cutting of mice tail hemostasia test ,study the performance of the product.The results showed that the water solubility of carboxymethyl chitosan is better than that of chitosan and with excellent performance,and the performance of carboxymethyl chitosan calcium and carboxymethyl chitosan zinc was better than that of carboxymethyl chitosan.

scholarly journals Pengaruh Model Pembelajaran Kooperatif Tipe Cooperative Integrated Reading and Compositi (CIRC) dan Minat Baca Terhadap Keterampilan Menulis Karangan Deskripsi Siswa Kelas X SMA Negeri 1 Bangkinang

GERAM ◽  
2020 ◽  
Vol 8 (2) ◽  
pp. 18-26
Author(s):  
Fenny Anita
Keyword(s):  
Writing Skills ◽  
Learning Model ◽  
Performance Tests ◽  
Learning Models ◽  
Factorial Experimental Design ◽  
Essay Writing ◽  
Quasi Experimental ◽  
And Performance ◽  
Reading Interest ◽  
Better Than

This research was conducted to explain the effect of the learning model CIRC and reading interest on the results of the descriptive essay writing skills of class X SMA Negeri 1 Bangkinang. This type of research is a quantitative study using a quasi-experimental method and a 2x2 factorial experimental design. The population of this study was students of class X SMA Negeri 1 Bangkinang. Sampling was done by purposive sampling with a sample size of 60 students. Data collection was carried out using two instruments, namely questionnaires and performance tests. Based on the research results, it can be concluded that four things are as follows. First, the skills of writing essays of descriptions of students taught using the learning model CIRC are better than those taught by conventional learning models of class X students of SMA Negeri 1 Bangkinang. Second, the writing skills of students who have high reading interest who are taught using the learning model CIRC are higher than students who have high reading interest who are taught using the conventional learning model of class X students of SMA Negeri 1 Bangkinang. Third, the writing skills of students who have low reading interest who are taught using the learning model CIRC are higher than students who have low reading interest who are taught using the conventional learning model of class X students of SMA Negeri 1 Bangkinang. Fourth, there is no interaction between reading interest and learning models in influencing the writing skills of descriptive essays of class X SMA Negeri 1 Bangkinang.

scholarly journals KUALITAS BELANJA DAERAH DAN HUBUNGANNYA DENGAN KINERJA PEMBANGUNAN DI PROVINSI BANTEN

2018 ◽  
Vol 6 (2) ◽  
pp. 16-31
Author(s):  
Sri Wahyuni ◽  
Bambang Juanda ◽  
Idqan Fahmi
Keyword(s):  
Structural Equation ◽  
Secondary Data ◽  
Equation Model ◽  
Version 2.0 ◽  
Performance Development ◽  
And Performance ◽  
The Relationship ◽  
Quality Map ◽  
Better Than

This study aims to analyze the relevant indicators of spending quality in measuring the quality of regional spending as well as the relationship between the quality of regional spending and the development performance of the regencies/cities of Banten Province. This study uses secondary data from the governance, financial and performance development of the districts/cities of Banten Province between 2009 – 2013. The Data are analyzed using Partial Least Squares Structural Equation Model (PLS–SEM) using SmartPLS software version 2.0 & SmartPLS version 3.0. The Results show that there are 21 indicators out of 40 indicators that are relevant in measuring the quality of the districts/cities spending in Banten Province. The change of the spending quality map from 2009 to 2013 shows that the quality of North Banten (Tangerang Regency, Tangerang City, Tangerang Selatan, Serang Regency, Serang City and Cilegon City) is better than South Banten (Pandeglang and Lebak). In addition, the estimation results from the model used indicate that the quality of the region spending of Banten Provinve has a positive relationship with the performance of development with the value of the indicator 0,678. Keywords : Development Performance, PLS-SEM, Spending Quality

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