HIFI Research Articles

C 2 Splitter Revamp Surpasses Capacity and Efficiency of 4-Pass Trays

A C2 Splitter in Norco, Louisiana was successfully revamped with Shell HiFi™ Plus trays in 2015 for increased tray capacity. The HiFi Plus tray is a joint development between Sulzer and Shell and is relatively new to the marketplace. These trays are intended for large diameter and high pressure/high liquid loaded applications such as those found in Ethylene Production. Benchmarking the capacity and performance of such trays will be invaluable to the distillation industry. Operating data were taken both before and after the revamp and will be presented in the paper along with tray hydraulic information. This paper will address two main issues, capacity and performance of Shell HiFi™ Plus trays and the very important topic of comparing the new trays against the old 4-Pass tray design. Discussions will include the observed excellent tray efficiency, operational hydraulics and pressure drop of the new trays. In addition, unique features of the HiFi Plus tray will be discussed that enabled this tray efficiency to be achieved.

Research on characteristic spectrum extracting and matching for high-fidelity reproduction.

Reconstructing the spectrum rapidly and accurately is the key to the research on high-fidelity reproduction. A characteristic spectrum extracting and matching method for high-fidelity printing is proposed aiming at the problem of complex conversion between spectrum and ink combination caused by multi-color. The method filters and extracts feature bands of primary ink through derivative spectrum, and a characteristic spectrum multi-threshold coding method is proposed. Considering the problem of subarea judgment in hi-fi printing, an average derivative spectrum is taken as characteristic spectrum of each subarea and a spectrum matching method between target spectrum and average derivative spectrum of sub-spaces is proposed. The results show that the feature bands extracted can represent spectral characteristic of primary color significantly and the precision of color conversion model based on feature bands is higher than the model based on full bands. The spectrum matching method can achieve a high accuracy in sub-space judgments and greatly improve the efficiency of color convention. The spectrum extracting and matching method has the high practicability.

To establish a new and simple method of genotyping of hepatitis B virus by PCR-RFLP to analysis on S region

Objective A method was established for genotyping of hepatitis B virus (HBV A-D genotype),based on the PCR-restriction fragment length polymorphism (RFLP) created by HinfⅠ,EarⅠ,ApoⅠ action on an amplified segment of the S region. Methods Clinical diagnosis research.One hundred and twenty-eight HBV S sequences obtained from GeneBank were analyzed for restriction enzyme sites that would be genotype-specific.Restriction patterns following digestion with restriction enzymes HifⅠ,EarⅠ,ApoⅠ were determined to identify A-D HBV genotypes.The method was used to detect the HBV genotype of fifty severe hepatitis patients due to chronic hepatitis B in China. Then the detection results were confirmed by direct sequencing. Results The new genotyping method was established,named simple PCR-RFLP,which could identify HBV genotypes A to D.Genotypes B,C,B/C and A or D could be determined by a single step digestion with HifⅠ. Eight patients of genotype A/B/C classified by single step digestion with HifⅠ were conformed as genotype B variant by further digestion and direct sequencing.Extracted randomly and diluted into different concentration,three specimens were tested for genotype of HBV repeatedly and respectively.The results were all in accord with the originals,and the lowest detection limit of HBV DNA was 7~9 IU/ml.This was particularly useful in China where genotypes B and C were predominant.Twenty-three of genotype B and ten genotype C patients were classified from these fifty severe hepatitis B patients by a single step digestion with HifⅠ through the simple PCR-RFLP method.The same results were also obtained by direct sequencing of PCR products (Kappa=1.00,P=0.001). The simple PCR-RFLP method was superior to direct sequencing in detecting HBV B/C polyinfection (9 cases and 0 case;χ2=18.00,P=0.001). Conclusions Both the sensitivity and repetitiveness of Simple PCR-RFLP method are satisfactory.It is superior to direct sequencing in detecting HBV B/C polyinfection,and simple,convenient.(Chin J Lab Med,2013,36:420-424) Key words: Hepatitis B virus; Genotype; Polymerase chain reaction; Polymorphism; restriction fragment length

Parameters of adaptability and stability in brazilian and exotic cultivars of white oat

The introduction of exotic germoplasm is one of the most important tools in obtaining genetic variability in breeding programs. However, it presents problems of adaptation and stability on specific conditions of climate and soil. The objective of the study was to evaluate the performance of Brazilian and exotic genotypes of oat (Avena sativa L.) and the parameters of adaptability and stability in different years of cultivation to local conditions in Capao do Leao/RS, Brazil. Experiments were conducted in 2005, 2006 and 2007 using ten US oat cultivars, thirteen brazilian cultivars and one canadian cultivar, in an experimental design of randomized blocks with three replications. The national usually outperformed the foreign genotypes, the latter showing difficulties in adaptation to the studied conditions. Cultivars Assiniboia and Hi-Fi had performances similar to the Brazilian elite genotypes, with adequate average production, good adaptability and phenotypic stability. The introduction of this type of germplasm may increase the gene pool with new groups of genes and/or alleles carrying genetic gains in the improvement of oats.

Swinging through the hi-fi jungle

Swinging through the hi-fi jungle

Stereo and Hi-Fi as a Pastime

Stereo and Hi-Fi as a Pastime

Cohen (A. B.). Hi-fi loudspeakers and enclosures

Cohen (A. B.). Hi-fi loudspeakers and enclosures

From Low Estate to Hi-Fi

From Low Estate to Hi-Fi

Hi-Fi from Microphone to Ear

Hi-Fi from Microphone to Ear