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1

Effect of sodium sulfide waste water recycling on the separation of chalcopyrite and molybdenite

Wu D., Peng H., Abdalla M.

Physicochemical Problems of Mineral Processing

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2018

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Vol. 54, iss. 3

629--638

EN

The effect of sodium sulfide waste water recycling on the separation of chalcopyrite and molybdenite was investigated in this work. The waste water, which was separated from the slurry after selective flotation, was recycled in the flotation system. This operation significantly improved the subsequent flotation of chalcopyrite and saved the reagent. The results showed that the depression efficiency of sodium sulfide gradually disappeared in the recycling tests due to the consumption. The consumption of sodium sulfide in the separation was not only caused by the adsorption on mineral surfaces but also resulted from the precipitation of metal ions which released from minerals. These effects decreased the solution reducibility and the adsorption of hydrosulfide ions, finally resulting in the less depression for chalcopyrite flotation. After adding a certain amount of sodium sulfide to the recycling, the depression of chalcopyrite performed well and the pulp potential maintained at a relatively lower level. Moreover, the pulp potential was an available parameter to control the flotation separation of chalcopyrite and molybdenite, which made the method easily applied to industry.

2

Wpływ dodatku nanokrzemionki na mikrostrukturę i właściwości autoklawizowanego betonu komórkowego

Li M., Qian X., Peng H., Wu Z

Cement Wapno Beton

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2017

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R. 22/84, nr 4

320--327

PL

Praca dotyczy modyfikacji autoklawizowanego betonu komórkowego [ABK] dodatkiem nanokrzemionki. Wprowadzenie nanokrzemionki spowodowało wzrost wytrzymałości ABK nawet o ponad 20% dla 4,8% dodatku nanokrzemionki, pomimo tego, że wzrósł również stosunek wodno/spoiwowy mieszanek. Obecność nanokrzemionki spowodowała również spadek przewodnictwa cieplnego ABK nawet o 15% dla 4,8% dodatku nanokrzemionki. Powodem tego były zarówno zmiany porowatości i jej rozkładu jak również spadek przewodnictwa cieplnego samej nienapowietrzonej matrycy ABK modyfikowanej nanokrzemionką. Wyniki pokazały również, że obecność nanokrzemionki powoduje wzrost ilości i stopnia wykrystalizowania tobermorytu oraz fazy C-S-H.

EN

Different contents of silicon dioxide nanoparticles [SDN] were used in autoclaved aerated concrete [AAC]. Introduction of SDN results in compressive strength increase up to over 20% for 4.8% SDN dosage, despite increased water/solid ratio in the presence of SDN. SDN presence causes also decrease in thermal conductivity up to over 15% for 4.8% dosage of SDN. This is due to both changes in porosity and pore structure as well as decreased thermal conductivity of SDN modified unaerated hardened matrix. The results showed that SDN increase the amount and degree of crystallinity of tobermorite and C-S-H phase.

3

Influence of FFL-13 Oil on PSA Staple Fiber Properties

Peng H., Zheng G., Sun Y., Wang R.

Autex Research Journal

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2017

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Vol. 17, no. 4

328--333

EN

With the aim of enabling the easy spinning of polysulfonamide (PSA) fibers, FFL-13 oil was successfully prepared. Specific resistance, the coefficient of friction, carding machine, electrostatic, cohesion, scanning tunneling microscopy (STM), and Fourier transform infrared (FTIR) spectroscopic analyses were conducted in this study. Results showed that increase in oil concentration, ambient temperature, and humidity induces decrease in PSA fiber-specific resistance and gradual increase in the antistatic property. Relatively high oil concentration and ambient humidity may cause fibers to become sticky and show increased roller winding. As oil concentration increased, fiber cohesion increased and fiber gliding properties showed an initial increase and subsequent decrease. The ideal oil concentration was determined to be 0.6%. This study proves that STM may effectively be used to determine the optimal oil concentration.

4

Predicting current and future invasion of Solidago canadensis; a study from China

Xu Z., Peng H., Feng Z., Abdulsalih N.

Polish Journal of Ecology

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2014

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Vol. 62, nr 2

263--271

EN

Solidago canadensis, which is native to North America, is considered to be the most widespread invasive alien plant. The invasion of Solidago canadensis in China has resulted in serious environmental problems. Therefore, understanding the relationship between the geographical distribution of S. canadensis and bioclimatic variables, and then predicting the potential distribution of this species is essential for management actions and practices. Although several studies have delineated the potential distribution of S. canadensis in China, how this species would respond to variations in future climatic conditions remains unclear. In the present study, we predicted the potential distribution of S. canadensis under current and future climatic conditions using species distribution models. We also analyzed range shifting of this species under current and future climatic conditions. We arrived at several conclusions. First, the potential distribution of S. canadensis may expand 40% under future climatic condition compare with that of under current condition. Second, mean diurnal range, isothermality, mean temperature of the wettest quarter, mean temperature of the warmest quarter, precipitation of the driest month, and precipitation seasonality (coefficient of variation) are key bioclimatic variables in determine the potential distribution of S. canadensis. Third, expansion of S. canadensis can be partly attributed to the relatively warmer and wetter future bioclimatic condition than current one.

5

A Body Characteristic Index to Evaluate the Level of Risk of Heat Strain for a Group of Workers With a Test

Lu S., Peng H., Gao P.

International Journal of Occupational Safety and Ergonomics

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2014

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Vol. 20, No. 4

647--659

EN

The purpose of this study was to develop a body characteristic index (BCI) based on the distribution of maximal oxygen uptake per body mass (VO2max/mass), body surface area per body mass (BSA/mass), and percentage of body fat (Fat%) to evaluate the relative level of individual physiological responses to heat strain in a group of workers. BCI was based upon the data obtained from 10 males and 10 females exercising for 60 min on a treadmill at 2 relative exercise intensities of 25% and 45% VO2max in mild, warm wet, and hot dry climate condition, separately. BCI was developed into 2 formulas, which were proved to be better predictors for heat strain responses than each individual characteristic, and more sensitive than body type to describe the distributions of individual characteristics and distinguish the differences in physiological responses to heat.

6

An efficient algorithm for estimating the parameters of superimposed exponential signals in multiplicative and additive noise

Bian J., Peng H., Xing J., Liu Z., Li H.

International Journal of Applied Mathematics and Computer Science

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2013

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Vol. 23, no. 1

117--129

EN

This paper considers parameter estimation of superimposed exponential signals in multiplicative and additive noise which are all independent and identically distributed. A modified Newton–Raphson algorithm is used to estimate the frequencies of the considered model, which is further used to estimate other linear parameters. It is proved that the modified Newton–Raphson algorithm is robust and the corresponding estimators of frequencies attain the same convergence rate with Least Squares Estimators (LSEs) under the same noise conditions, but it outperforms LSEs in terms of the mean squared errors. Finally, the effectiveness of the algorithm is verified by some numerical experiments.

7

Characteristics of elastic wave propagation in thick beams - when guided waves prevail?

Peng H., Ye L., Meng G., Sun K., Li F.

Journal of Theoretical and Applied Mechanics

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2011

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Vol. 49 nr 3

807-823

EN

Characteristics of wave propagation in thick beams are analyzed using a three-dimensional (3-D) spectral element method (SEM) for the purpose of damage detection. Analysis of wave propagation in beams of different thickness under excitations with different central frequency reveals that when the thickness of the beam is comparable to the wavelength of the elastic wave, a local wave mode, besides quasi-symmetric and quasi-anti-symmetric modes, exist simultaneously in the beam. In particular, when the wavelength is more than two times the beam thickness, the local wave modes are suppressed and the wave modes in the beam can be regarded as traditional guided waves, i.e., Lamb waves. It is demonstrated that the central frequency of wave signals can be selected according to the dimensions of the beam to obtain simple wave modes like those in thin beams. The characteristics of wave propagation in an intact beam and beams with a lateral crack are analyzed and the results are also validated by experiments, where wave propagation signals in thick steel beams are activated and captured using PZT elements.

PL

Praca przedstawia problem detekcji uszkodzeń w belkach o znacznej grubości za pomocą trójwymiarowej metody elementów spektralnych (SEM) ze szczególnym uwzględnieniem charakterystyk propagacji fal w ośrodku. Analiza rozchodzenia się fal w belkach o różnej grubości poddanych wymuszeniom o różnej częstotliwości centralnej ujawniła, że gdy grubość belki jest porównywalna z długością fali sprężystej, to oprócz quasi-symetrycznych i quasi-antysymetrycznych postaci pojawia się lokalna postać własna fali. Gdy długość fali przekracza co najmniej dwukrotnie grubość belki, postacie lokalne zanikają i postacie fal mogą zostać uznane jako tradycyjne fale prowadzone, tj. fale Lamba. Pokazano, że centralna częstotliwość sygnałów falowych może zostać dobrana do konkretnych rozmiarów belki tak, aby otrzymać proste postacie własne fal przypominające kształt fal rozchodzących się w belkach cienkich. W pracy zbadano charakterystyki propagacji fal w belce nieuszkodzonej i belce z pęknięciem poprzecznym. Rezultaty tych badań zweryfikowano doświadczalnie poprzez generowanie i rejestrację sygnałów w grubych stalowych belkach aktuatorami i czujnikami piezoelektrycznymi.

8

Laser diode array (LDA) end-pumped multi-watt Yb:YAG 1030 nm laser

Cao H., Peng H., Zhang M., Chen Y., Zhang B., Chen B., Zhang J., Wu T., Zhao X., Tan H.

Optica Applicata

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2010

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Vol. 40, nr 3

653--656

EN

A LDA (laser diode array) end-pumped Yb:YAG 1030 nm laser is reported. Using a plano-concave resonator, with input pump power of 11.79 W, 2.55 W TEM00 continuous wave laser at 1030 nm was obtained. The effective focal length of the thermal lens is also calculated.