Profiling Rotors for Limaçon-to-Limaçon Compression-Expansion Machines

2005 ◽  
Vol 128 (4) ◽  
pp. 787-793 ◽  
Author(s):  
Ibrahim A. Sultan

Limaçon-to-limaçon compression-expansion machines have housings and rotors whose profiles are manufactured of limaçon curves. For these machines to perform satisfactorily, extreme care should be given to the geometric particulars of their rotor profile. The main characteristics that govern the quality of the rotor profile are the volumetric efficiency and the prevention of interference. In this work, the interference problem is handled from two different mathematical standpoints: the slope of tangents to both the rotor and housing curves at the apices; and the value of the minimum radial clearance that separates the two limaçon curves. In the first case, mathematical expressions, relating the radii of the limaçon base circles is presented to ensure that interference would not take place during normal operations of the limaçon-to-limaçon machine. The second mode of analysis produces a set of nonlinear equations that can be solved to obtain a value of the radial clearance. This value has to be machined off the rotor profile to prevent interference. A numerical example is given at the end of the paper to prove the validity of the models proposed and graphs are produced to support the claims presented.

Author(s):  
Ramiro Remigio Gaibor Fernández ◽  
Abraham Adalberto Bayas Zamora ◽  
Galo Israel Muñoz Sánchez ◽  
Cristhian Adrián Rivas Santacruz

The objective of the present investigation was to evaluate the physical characteristics of the vermicompost and the quality of the purine of the red Californian (Eisenia foetida) using different substrates of feed for these worms. For this purpose, nine treatments were studied: 75% African palm rachis + 25% cattle manure, 50% African palm rachis + 50% cattle manure, 25% African palm rachis + 75% livestock manure, 50% manure of cattle, 50% of manure of cattle, 25% of manure of cattle, 50% of manure of cattle, 50% of manure of cattle, 50% of rach of coconut + 50% of manure of Livestock, 25% coccus rachis + 75% livestock manure. The substrate made up of 50% of rachis of coconut and 50% of livestock manure can be used in nurseries or nurseries for being the one that registered a value of pH 7.3 plus the closest to the neutral compared to the others, besides this (75% of oil palm rachis and 25% of cattle manure) showed a higher content of humic and fulvic acids (0.87 and 0.45 p / p, respectively), compounds that are important for agriculture by stimulating plant growth, in addition to this reflection 0.06% sulfur content, 4.0 ppm boron, 7.0 ppm copper, 47.5 ppm iron, 6.0 ppm manganese, with a presence of microorganisms of the species Trichoderma, Penicillium, Cladosporium sp. in amounts of 1.91x105 UFC / ml, however in this substrate was obtained between 13.3 and 43.5% less liquid slurry in Comparison with other treatments.


2020 ◽  
Vol 4 (2) ◽  
Author(s):  
Danar Agus Susanto

ABSTRACTIndonesia is the world's largest producer of crude palm oil (CPO). Even so, the trend of international trade in Indonesian CPO products has decreased in the last 10 years with a value of -10.19%. The decline in world demand for CPO can be dealt with by utilizing CPO as a biofuel for domestic use, like biodiesel. The purpose of this study is to determine the competitiveness of Indonesian CPO in global trade and determine the parameters of the quality requirements of CPO and biodiesel. The competitiveness analysis method uses the Revealed Comparative Advantage (RCA) method, while the analysis of the potential quality of CPO as a biofuel is carried out by analyzing the Indonesian National Standard (SNI). CPO trade in the global market is controlled by Indonesia with a market share of 50% and Malaysia 25.6%, with the declining trade trend in the last 10 years relatively (2010-2019) of -6.91%. The level of competitiveness of Indonesian CPO products in 2019 is very strong, but on average in the last 10 years, the level of competitiveness of Indonesian CPO is no better than that of Malaysia. Indonesia has SNI 01-2901-2006 and SNI 7182: 2015 as a determinant of the quality of CPO and biodiesel products developed in Indonesia so that the CPO and biodiesel produced fullfil sacurity and safety aspects when used by consumers.Keywords: crude palm oil (CPO), competitivenessv, quality, Indonesian National Standard (SNI) ABSTRAKIndonesia merupakan negara produsen minyak kelapa sawit mentah/ Crude Palm Oil (CPO) terbesar di dunia. Meskipun demikian, tren perdagangan internasional produk CPO Indonesia mengalami penurunan dalam sepuluh tahun terakhir dengan nilai -10,19%. Penurunan permintaan dunia terhadap CPO, dapat disiasati dengan memanfaatkan CPO sebagai bahan bakar nabati untuk keperluan dalam negeri sebagai biodiesel. Tujuan penelitian ini adalah mengetahui daya saing CPO Indonesia dalam perdagangan global dan mengetahui parameter persyaratan mutu CPO dan biodiesel. Metode analisis daya saing menggunakan metode Revealed Comparative Advantage (RCA), sedangkan analisis potensi kualitas CPO sebagai biofuel dilakukan dengan menganalisis Standar Nasional Indoensia (SNI). Perdagangan CPO dalam pasar global dikuasai oleh Indonesia dengan pangsa pasar 50% dan Malaysia 25,6%, dengan tren perdagangan relatif menurun dalam 10 tahun terakhir (2010-2019) sebesar -6,91%. Tingkat daya saing produk CPO Indonesia pada tahun 2019 sangat kuat, namun secara rata-rata dalam 10 tahun terakhir, tingkat daya saing CPO Indonesia tidak lebih baik dari Malaysia. Indonesia memiliki SNI 01-2901-2006 dan SNI 7182:2015 sebagai penentu kualitas produk CPO dan biodiesel yang dikembangkan di Indonesia, sehingga CPO dan biodiesel yang dihasilkan memenuhi aspek keamanan dan keselamatan ketika digunakan oleh konsumen.Kata kunci: crude palm oil (CPO), daya saing, kualitas, Standar Nasional Indonesia (SNI)


2019 ◽  
Author(s):  
Sabine Keim ◽  
Alexandra von Au ◽  
Lina Maria Matthies ◽  
Stephanie Wallwiener ◽  
Sarah Brugger ◽  
...  

BACKGROUND Background: Many women experience urinary incontinence (UI) during andafter pregnancy due to pelvic floor weakness. First-line therapy is conservative treatment, which nowadays can be facilitated by using digitalsolutions. OBJECTIVE The aim ofthe present study was to investigate the efficacy and effectiveness of pelvinain patients with existing UI. METHODS Methods: In the present observational study we analyzed the effectivenessof pelvina, a certified digital pelvic floor training course, in reducing UI symptoms by regularly applying “The Questionnaire for Urinary Incontinence Diagnosis” (QUID) and furthermore examining quality of life (QoL) by conducting the SF-6D. RESULTS Results: In this prospective study, 373 patients with a median age of 36 years (IQR 33 - 47 years) were included. At baseline the patients had a median QUID of 11 (IQR 11 - 15). During the course, incontinence improved significantly to a QUID of 5 (IQR 2 – 11; p<0.001). Additionally, the patients had also shown a significant impairment in their QoL at baseline with a value of 19 (IQR 16 - 22) in SF-6D. After completing the course, the QoL had risen to 24 (IQR 20 - 26). CONCLUSIONS Conclusion: Use of the certified digital pelvic floor course pelvinasignificantly reduces existing UI due to pelvic floor weakness over the timespan of the course. At the same time QoL is significantly improved. CLINICALTRIAL The present study was approved by the ethics committee of the Heidelberg University Hospital (S-392/2019)


1958 ◽  
Vol 25 (1) ◽  
pp. 32-51 ◽  
Author(s):  
Peggy B. Taylor ◽  
L. F. L. Clegg

The determination of apparent lactic acid has been used as a basis for a rejection test for raw milk. The method consists of precipitation of milk proteins with barium chloride, sodium hydroxide and zinc sulphate, and the addition of ferric chloride to the filtrate to produce the yellow colour of ferric lactate. Lactic acid is not solely responsible for the production of the yellow colour, which, nevertheless, gives a good relationship with keeping quality of milk (measured as hours to the C.O.B. end-point at 22° C.) and the values have been expressed as ‘apparent lactic acid’.The relationship of winter and summer milks to keeping quality has been studied, and a value of 0·03% apparent lactic acid in milk is equivalent to an average keeping quality of 5¾ and 8½ hr. for winter and summer milks, respectively. A value of 0·03% is recommended as the earliest value of apparent lactic acid at which milk could be rejected.The apparent lactic acid in colostrum and late-lactation milk and in milk from cows suffering from mastitis has been determined, and only in late-lactation milk were the values found to be significantly higher than usual in fresh raw milk, and an inverse relationship between yield and apparent lactic acid is suggested.Permanent glass matching disks have been prepared for use in a Lovibond comparator. This permits the intensity of the yellow colour produced with 1% ferric chloride to be determined and the apparent lactic acid in milk estimated.Grateful acknowledgement is made to the management and staff of the Dairy Department of the Reading Co-operative Society and the Farmer's Clean Milk Dairy, Reading, and local milk producers for supplying samples for experiments; to the N.M.T.S. staff in Reading for help in finding suitable farmers, and to the Dairy Husbandry Department of the N.I.R.D. for information about and samples of abnormal and late-lactation milk. Our particular thanks are due Miss Marie Gruber for technical assistance, to Dr N. J. Berridge for the suggestion and help on the work on pH change as an indication of keeping quality (given in the appendix), and to Dr A. T. R. Mattick for the advice given in this work.


JOURNAL ASRO ◽  
2018 ◽  
Vol 9 (1) ◽  
pp. 37
Author(s):  
Riono Riono ◽  
Suparno Suparno ◽  
Adi Bandono

ABSTRAK In carrying out its main duty as a guardian of the territorial water sovereignty republic Indonesia, the strength of the Navy is directed as a strategic force developed under the SSAT. The strength of the Navy can be measured by the arsenal and the quality of the personnel who are responsible for it. The performance, quality of personnel is strongly influenced by the work load it receives. Measurement of personnel workload in Indonesian Warship to determine the class of his current position using the Factor Evaluation System (FES) method that is more oriented on the volume of work and work time. While the mental workload has not been accommodated in the measurement of workload using this method. In this research will carry out the measurement of mental workload of Indonesian Warship personnel for each type of work when the Indonesian Warship operates, using the NASA TLX method integrated with the Fuzzy method. The questionnaire data collection was obtained from 82 respondents Indonesian Warship personnel. From the research results obtained data that of 11 (eleven) types of work in Indonesian Warship at the time of operation, Main Engine Operators work is the work that has the highest mental workload with a value of 74.33. While the type of work that most low-level mental work is to electronics Operators with a value of 58.83.  Keywords: Workload, NASA TLX, FUZZY Method, FES


Author(s):  
Carolin Feldmann ◽  
Thomas Carolus ◽  
Marc Schneider

Fans are main components e.g. in heating, ventilating and air conditioning systems for vehicles or buildings, cooling units of engines and electronic circuits, and household appliances such as kitchen exhaust hoods or vacuum cleaners. End-users increasingly demand a high sound quality of their system or device. The overall objective of a recent research project at the University of Siegen is a multidimensional assessment of fan sound quality. In a first step an advanced novel semantic differential for the assessment of fan-related sounds is established with the aid of carefully designed jury tests. Eventually, this semantic differential is employed for sound quality jury tests of fans in kitchen exhaust hoods, heat pumps and air purifiers as a first case. Finally, a prediction model is suggested, which relates the outcome from the jury tests to objective metrics. A principal component analysis is carried out and yields five main assessment criteria with 23 relevant adjective scales. The results show that the perceived sound quality of fan systems is mainly determined by the loudness and tonality of the sound. The spectral content (represented by the sharpness) as well as the time structure (represented by the roughness) have no significant impact on perceived sound quality of the fan systems investigated.


1995 ◽  
Vol 10 (8) ◽  
pp. 1884-1888 ◽  
Author(s):  
S. Krishnan ◽  
M.I. Chaudhry ◽  
S.V. Babu

Amorphous silicon germanium (a-SiGe) films, deposited on silicon substrates at room temperature in a molecular beam epitaxy system, were transformed into a single-crystal film and doped with phosphorus by exposure to KrF laser pulses. Electron channeling patterns showed that laser exposure resulted in crystallization of the undoped a-SiGe films. The SiGe films were doped by laser irradiation, using a phosphorus spin-on-dopant. The sheet resistance of the doped films decreased with increasing numbers of pulses, reaching a value of about ∼ 5 × 104 ohms/□ after 15 pulses. I-V data from mesa-type n-SiGe/p-Si diode devices were used to determine the effect of laser processing on the quality of the SiGe films.


1989 ◽  
Vol 160 ◽  
Author(s):  
Nigel M. Jennett ◽  
D.J. Dingley ◽  
Y. Ando

AbstractBilayers of Cu/Fe and Cu/V and multilayers of Ni/Fe have been grown under high vacuum and ultra high vacuum conditions respectively with [111] epitaxy. Multilayer layer thicknesses ranged from 3 monolayers to 15 monolayers per layer. Improved epitaxy of the UHV growth was, we believe, due to the better vacuum although perfect material could only be obtained for growth within a narrow and shifting substrate temperature ‘window’. Possible shortfall in the quality of the Cu backing layer epitaxy was averted by a 2hr anneal at 425°C.In the Fe/Ni multilayers the Fe was observed to adopt the FCC lattice rather than the equilibrium BCC lattice for layer thicknesses less than 10 monolayers. This change of structure coincided with a reduction in sample magnetic moment per volume attributed to a collapse of the Fe moment to a value 7 times less than bulk.


2012 ◽  
Vol 504-506 ◽  
pp. 1329-1334 ◽  
Author(s):  
Moises Batista ◽  
Madalina Calamaz ◽  
Franck Girot ◽  
Jorge Salguero ◽  
Mariano Marcos

The forces involved in a cutting process are related, for example, with the power consumption, with the final quality of the workpiece and with the chip geometry obtained, since these forces determine the compression experimented by the chip and therefore its final geometry. The orthogonal cutting process assisted with a High Speed Filmation (HSF) permit obtains a digital filmation of the process with high magnification. This filmation permits to obtain a measurement of the longitudinal changes produced in the chip. This deforms are related with the Shrinkage Factor, ζ. And in this case the Stabler hypothesis is enabled, by that using the shear angle and the rake angle is possible obtain a value of the Shrinkage Factor in a different conditions.


CAUCHY ◽  
2015 ◽  
Vol 4 (1) ◽  
pp. 10 ◽  
Author(s):  
Venny Riana Riana Agustin ◽  
Wahyu Henky Irawan

Tsukamoto method is one method of fuzzy inference system on fuzzy logic for decision making. Steps of the decision making in this method, namely fuzzyfication (process changing the input into kabur), the establishment of fuzzy rules, fuzzy logic analysis, defuzzyfication (affirmation), as well as the conclusion and interpretation of the results. The results from this research are steps of the decision making in Tsukamoto method, namely fuzzyfication (process changing the input into kabur), the establishment of fuzzy rules by the general form IF a is A THEN B is B, fuzzy logic analysis to get alpha in every rule, defuzzyfication (affirmation) by weighted average method, as well as the conclusion and interpretation of the results. On customers at the case, in value of 16 the quality of services, the value of 17 the quality of goods, and value of 16 a price, a value of the results is 45,29063 and the level is low satisfaction


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