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Preparation of Hollow Fibre Composite Reverse Osmosis Membrane  [cached]
Fengjuan Li,Wei Wang,Qiang Ren
Modern Applied Science , 2009, DOI: 10.5539/mas.v4n1p82
Abstract: A novel thin-?lm composite (TFC) reverse osmosis (RO) membrane was developed by the interfacial polymerization (IP) of trimesoyl chloride (TMC) and m-phenylene diamine (MPD) on the hollow fibre ultrafiltration polysulphone (PS) membrane. The performance of the TFC membrane was optimized by studying the preparation parameters, which included monomer TMC concentration, monomer MPD concentration and alcohol additive in aqueous solution. The reverse osmosis performance of the resulting membrane was evaluated through permeation experiment with 1000 ppm NaCl at 0.7 MPa. The results showed that the optimum concentration of MPD and TMC were 0.5wt% and 3g/L, respectively. To improve flux, alcohol was added to the aqueous phase, when certain concentration of alcohol was added to the aqueous solution, the flux of the prepared membrane increased from 5.0 to 9.1 L/(m2·h) without loss in salt rejection. The properties and structures of skin layer of RO composite membranes were characterized by AFM. It was found that IP had occurred and the separation layer was formed, and the novel reverse osmosis membrane appears to comprise a thicker, smoother and less cross-linking film structure. Additionally, the TFC membrane exhibits good long-term stability.
Design of Broadband Single Fundamental Mode Hollow Core Bragg Fibre
LIN Chen-Xi,ZHANG Wei,HUANG Yi-Dong,PENG Jiang-De,

中国物理快报 , 2008,
Abstract: The condition of the single fundamental mode (HE11) transmission in hollow core Bragg fibres is investigated theoretically by the transfer matrix method. The influences of core size and cladding parameters on the single HE11 mode bandwidth are analysed, showing that the maximal bandwidth is more sensitive to the core size than the cladding. The numerical results show that sufficiently broad bandwidth of single HE11 mode transmission can be achieved by proper fibre design. A simple and fast method based on improvedhollow metal waveguide model is proposed to optimize fibre structure parameters for the maximal single HE11 mode bandwidth.
A dark hollow beam from a selectively liquid-filled photonic crystal fibre

Zhang Mei-Yan,Li Shu-Guang,Yao Yan-Yan,Fu Bo,Zhang Lei,

中国物理 B , 2010,
Abstract: This paper reports that, based on the electromagnetic scattering theory of the multipole method, a high-quality hollow beam is produced through a selectively liquid-filled photonic crystal fibre. Instead of a doughnut shape, a typical hollow beam is produced by other methods; the mode-field images of the hollow-beam photonic crystal fibre satisfy sixth-order rotation symmetry, according to the symmetry of the photonic crystal fibre (PCF) structure. A dark spot size of the liquid-filled photonic crystal fibre-generated hollow beam can be tuned by inserting liquid into the cladding region and varying the photonic crystal fibre structure parameters. The liquid-filled PCF makes a convenient and flexible tool for the guiding and trapping of atoms and the creation of all-fibre optical tweezers.
Fishing with Otters: a Traditional Conservation Practice in Bangladesh
Mohammed Mostafa Feeroz,Sajeda Begum,Md. Kamrul Hasan
IUCN Otter Specialist Group Bulletin , 2011,
Abstract: Fishing with otters has been practiced in Bangladesh for the last two hundred years. This traditional practice plays an important role in otter conservation in Bangladesh. Among the three species of otters found in Bangladesh, only Lutra perspicillata is currently used for fishing by the fishermen in and around the Sundarbans. Noraile and Khulna districts, near the Sundarbans, are the only districts in the country where this species is bred in captivity, tamed, and used for fishing by the fishermen. These fishermen are completely dependent on this technique for their livelihood. These tamed otters are used for fishing in rivers inside the Sundarbans during winter and pre-monsoon. Fishing occurs outside the Sundarbans only during monsoon. The whole fishing system is unique, involving three people, a boat, a net, two adult tamed otters, and an immature trainee otter. The tamed otters generally do not catch fish by themselves during fishing rather they chase fish towards a special fishing net placed in the water away from the boat. Otters start driving fish to the net from different directions and when they come close to the net, the fishermen pull the net into the boat. Fishing with otters occurs at night, mostly between 2100h and 0500h. Fish are captured during 8 to 12 periods by each fishing group per night. The total nightly weight of captured fish varies from 4 to 12 kg. We recorded 176 otters of different age and sex classes in captivity belonging to 46 fishermen groups in two districts. Among these, 138 adult otters are actively involved in fishing. The remaining animals are infants, juveniles, or very old. These otters breed successfully in captivity and maintain their population. Approximately 300 people are directly involved in this fishing technique and another 2,000 people indirectly depend on this method of fishing for their livelihood. This species of otter is conserved traditionally both in captivity and in the wild in this area.
Saturation Spectroscopy of Iodine in Hollow-core Optical Fibre  [PDF]
Anna Lurie,Philip S. Light,James Anstie,Thomas M. Stace,Paul C. Abbott,Fetah Benabid,Andre N. Luiten
Physics , 2012,
Abstract: We present high-resolution spectroscopy of Iodine vapour that is loaded and trapped within the core of a hollow-core photonic crystal fibre (HC-PCF). We compare the observed spectroscopic features to those seen in a conventional iodine cell and show that the saturation characteristics differ significantly. Despite the confined geometry it was still possible to obtain sub-Doppler features with a spectral width of ~6 MHz with very high contrast. We provide a simple theory which closely reproduces all the key observations of the experiment.
Preparation and Characterization of the Modified Polyvinylidene Fluoride (PVDF) Hollow Fibre Microfiltration Membrane
Preparation and Characterization of the Modified Polyvinylidene Fluoride (PVDF) Hollow Fibre Microfiltration Membrane

Laizhou SONG,Zunju ZHANG,Shizhe SONG,Zhiming GAO,

材料科学技术学报 , 2007,
Abstract: A novel thermally induced graft polymerization technique was used to modify a polyvinylidene fluoride (PVDF) hollow fibre microfiltration membrane. An artificial neural network (ANN) was applied to optimize the prepared condition of the membrane. The optimized dosing of acrylic acid (AA), acrylamide (AM), N, N'-methylenebisacrylamide (NMBA) and potassium persulphate (KSP) designed by ANN was that AA was 40.63 ml/L; AM acted as 6.25 g/L; NMBA was 1.72 g/L and KSP was 1.5 g/L, respectively. The thermal stability of the PVDF modified hollow fibre membrane (PVDF-PAA) was investigated by thermogravimetric (TG) and differential scanning calorimetry (DSC) analysis. The polycrystallinity of the PVDF-PAA membrane was evaluated by X-ray diffraction (XRD) analysis. The complex formation of the modified membrane was ascertained by Fourier transform infrared spectroscopy (FTIR). The morphology of the PVDF-PAA membrane was studied by environmental scanning electron microscopy (ESEM). The surface compositions of the membrane were analyzed by X-ray photoelectron spectroscopy (XPS). The adsorption capacity of Cu2+ ion on the PVDF-PAA hollow fibre membrane was also investigated.
Developments of Liquid-Phase Microextraction Based on Hollow Fiber

WANG Chun,WU Qiuhua,WANG Zhi,HAN Dandan,HU Yanxue,

色谱 , 2006,
Abstract: The liquid-phase microextraction(LPME),based on disposable hollow fiber,has been developed to be a new environmentally benign sample preparation technique which incorporate sampling,extraction and concentration into a single step.The novel technique can be easily manipulated in combination with high performance liquid chromatography,gas chromatography and capillary electrophoresis,and can provide excellent sample clean-up effect and high degree of extraction recovery and enrichment.It is proved to be simple,low-cost and virtually solvent-free.The extraction set-up,extraction mode,basic principles and recent applications of the hollow fiber-based liquid-phase microextraction are reviewed.
Extraction of Cu(II) Ions in Wastewaters Using New Solid/Liquid Phase Microextraction Technique Based on Incorporating Functionalized Carbon Nanotubes into Polypropylene Hollow Fiber
Es’haghi Zarrin,Ahmadpour Ali,Tanha Ali Akbar,Sayfi Ali,Ayati Ali
Open Access Library Journal (OALib Journal) , 2014, DOI: 10.4236/oalib.1100380
Abstract: This research describes a new design of hollow fiber solid-liquid phase microextraction (HF– SLPME) which was developed for the extraction and measurement of Cu(II) ion in water samples combined with atomic absorption spectroscopy. This method consists of an aqueous feed and the functionalized multi-walled carbon nanotubes (F-MWCNTs) with HNO3 and NaClO, dispersed into n-octanol, are held within the pores and the lumen of a porous hollow fiber as the extractor phase. The presented method allows an effective and enriched recuperation of ionic analyte into MWCNTs/organic phase. The effective parameters were investigated. Under the optimized conditions, a sample of industrial waste water was successfully purified using the proposed method. Our results showed that at optimized extraction conditions, the calibration curve was linear in the range of 0.01 - 20 μg/mL of Cu(II) ions in the initial solution with R2 > 0.99 for both F-MWCNTs samples. All experiments were carried out at room temperature (25℃ ± 0.5℃).
Extraction and Determination of Three Chlorophenols by Hollow Fiber Liquid Phase Microextraction - Spectrophotometric Analysis, and Evaluation Procedures Using Mean Centering of Ratio Spectra Method  [PDF]
Zarrin Es'haghi
American Journal of Analytical Chemistry (AJAC) , 2011, DOI: 10.4236/ajac.2011.21001
Abstract: A method termed hollow fiber liquid phase microextraction (HF-LPME) was utilized to extract three chlo- rophenols, 2-chlorophenol (2-CP), 2,4-dichlorophenol (2,4-DCP) and 2,4,6- trichlorophenol (2,4,6-TCP), separately from water. The extracted chlorophenols were then separated, identified, and quantified by UV-Vis spectrophotometry with photodiode array detection (UV-Vis/DAD). In the study, experimental con-ditions such as organic phase identity, acceptor phase volume, sample agitation, extraction time, acceptor phase NaOH concentration, donor phase HCl concentration, salt addition, and UV absorption wavelength were optimized. The statistical parameters of the proposed method were investigated under the selected con-ditions. The analytical characteristics of the method such as detection limit, accuracy, precision, relative standard deviation (R.S.D.) and relative standard error (R.S.E.) was calculated. The results showed that the proposed method is simple, rapid, accurate and precise for the analysis of ternary mixtures.
Investigation of the guided-mode characteristics of hollow-core photonic band-gap fibre with interstitial holes

Yuan Jin-Hui,Yu Chong-Xiu,Sang Xin-Zhu,Zhang Jin-Long,Zhou Gui-Yao,Li Shu-Guang,Hou Lan-Tian,

中国物理 B , 2011,
Abstract: This paper investigates the guided-mode characteristics of hollow-core photonic band-gap fibre (HC-PBGF) with interstitial holes fabricated by an improved twice stack-and-draw technique at visible wavelengths. Based on the simulation model with interstitial holes, the influence of glass interstitial apexes on photonic band-gaps is discussed. The existing forms of guided-mode in part band gaps are shown by using the full-vector plane-wave method. In the experiment, the observed transmission spectrum corresponds to the part band gaps obtained by simulation. The fundamental and second-order guided-modes with mixture of yellow and green light are observed through choosing appropriate fibre length and adjusting coupling device. The loss mechanism of guided-modes in HC-PBGF is also discussed.
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