VISUAL OBSERBATION OF HCFC141b GAS HYDRATE FORMATION/DECOMPOSITION PROCESS OUTSIDE OF A TUBE

In order to design a kind of heat exchanger suitable to the indirect-touched gas hydrate cool storage vessel, a visual observation of HCFC141b gas hydrate formation/decomposition process was presented through a self-designed small-scale visualization apparatus of gas hydrate cool storage. Based on the shooted photos and recorded temperatures, the formation/decomposition process of HCFC141b are described, some characteristics are concluded, and some suggestions of designing heat exchanger are indicated according to the specific characteristics of HCFC141b gas hydrate formation/decomposition process.

Modal identification based on Hilbert-Huang Transform of structural response with S VD preprocessing

In recent years, Empirical mode decomposition and Hilbert spectral analysis have been combined to identify system parameters. Singular-Value Decomposition is pro- posed as a signal preprocessing technique of Hilbert-Huang Transform to extract modal parameters for closely spaced modes and low-energy components. The proposed method is applied to a simulated airplane model built in Automatic Dynamic Analysis of Mechanical Systems software. The results demonstrate that the identified modal parameters are in good agreement with the baseline model.

New fast algorithm for hypercomplex decomposition and hypercomplex cross-correlation

In order to calculate the cross-correlation of two color images treated as vector in a holistic manner,a rapid vertical/parallel decomposition algorithm for quaternion is presented.The calculation for decomposition is reduced from 21 times to 4 times real number multiplications with the same results.An algorithm for cross-correlation of color images based on decomposition in time domain is put forward,in which some properties pointed out in this paper can be utilized to reduce the computational complexity.Simulation results show the effectiveness and superiority of the proposed method.

Competitive Complexation of Copper and Zinc by Sequentially Extracted Humic Substances from Manure Compost

Chicken manure with similar content of copper and zinc was changes of organic carbon and humus substance complexed chosen to conduct a composting experiment to investigate the copper （HS-Cu） and zinc （HS-Zn）, which were extracted by water （H2O）, sodium hydroxide （NaOH）, and sodium pyrophate-NaOH mixture （Na4P2O7-NaOH）, sequentially. Distributions of copper and zinc in fulvic acids （FA） and humic acids （HA） in the three extracts were studied. During manure composting, the concentrations of copper and zinc increased from about 500 mg kg^-1 in the raw material to 1 100 mg kg^-1 in the final products. HS-Cu in H2O, NaOH, and Na4P2O7-NaOH extracts occupied 6.7, 26.7, and 19% averagely of total copper and HS-Zn represented 2.7, 13.7, and 17% averagely of total zinc in compost, respectively. In water extracts, both HA and FA mainly complexed with Cu and the mole ratio of Cu to Zn was 2.8 in HA fractions and was 2.6 in FA fractions, respectively. HA mainly complexed with copper, so that the ratios of HA-Cu to HA-Zn averaged 3.4 in NaOH extracts. FA had a similar potential to complex with copper and zinc, so that the ratio of FA-Cu to FA-Zn was close to 1. In Na4P2O7-NaOH extracts, HA or FA had a similar potential to complex with copper and zinc. The ratio of HS-Cu to HS-Zn was close to 1. With manure composting, Na4P2O7-NaOH extractable HS-Zn increased to a level as high as HS-Cu. This indicated that more and more stable complexes of HS-Zn were formed in the late decomposition period. The competition between copper and zinc to be complexed with humic substance became weaker and weaker with the decomposition process.

Diversity of the Formicidae (Hymenoptera) carrion communities in Lisbon (Portugal): preliminary approach as seasonal and geographic indicators

The value of the Formicidae (Insecta,Hymenoptera) community in forensic investigations is poorly studied in Portugal.In order to better understand the structure and dynamics of this group of insects in cadavers and their putative value in forensic investigations,studies were carried out in Lisbon area during one year.Piglet carcasses were used as a model of human decomposition.The entomofauna attracted to the carcasses was collected over a period of about 2 months in each season of the year.The collection of ants was performed at regular intervals,daily in the first 23 days and then with intervals of 2,3 or 5 days until the end of the experiment.Five stages of cadaveric decomposition were recognized with the ants being present in all of them.Three hundred and nine specimens were captured: 7 in autumn,6 in winter,90 in spring and 206 in summer.These specimens belong to three subfamilies and seven different species.Four of them had never been mentioned before as being associated to cadavers in this geographical area.Spring and summer had the greater diversity of species and a larger number of individuals.Temnothorax luteus was the dominant species in spring and Tapinoma nigerrimum in summer.Corroborating the information of other similar studies carried out in the Iberian Peninsula,the sarcosaprophagous Formicidae community found in Lisbon is unique and different from other studied locations,which supports the need to perform regional studies.Our results shown that ants do not present a definite pattern of succession,but some species have the potential to be seasonal or geographic indicators.