120 research outputs found

    NGHIÊN CỨU KHẢ NĂNG CHỐNG CHỊU VÀ HẤP THU CHÌ Pb, Zn CỦA DƯƠNG XỈ PTERIS VITTATA L.

    Get PDF
    Phytoremendiation is a new treatment technique in pollution which has been studying and developing in recent years. In comparison to the other techniques, this is proved to be more effective, economical and be able to prevent negative consequences. The results from the experiment named “the study about the resistibility and absorptivity  of the Pteris vittata fern to Pb and Zn” have shown that Pteris vittata can be able to resist Pb contained in the earth at a concentration of 3000 mg/kg, despite the fact that  its best level of Pb resistance and absorptivity is less than 1000 mg/kg of earth. In the case of Zn, this fern species can withstand to a concentration of 1500 mg/kg of earth. Whereas, Pteris Vittata can absort and store up the most when the Zn concentration in earth is 300 mg/kg. The content of Pb and Zn in fronds and roots of Pteris Vittata increases when the concentration of these two elements in earth rises up. Pteris vittata’s ability to store Pb and Zn is reduced by time, however, the effectiveness to eliminate these two elements increases as a consequence of increasing its biomass

    PHÂN TÍCH NGUYÊN TỐ VẾT LẮNG ĐỌNG TRONG KHÔNG KHÍ QUA RÊU BARBULA INDICA TẠI THÀNH PHỐ BẢO LỘC SỬ DỤNG KỸ THUẬT HUỲNH QUANG TIA X PHẢN XẠ TOÀN PHẦN

    Get PDF
    In this investigation, the Total Reflection X-ray Fluorescence (TXRF) technique detected 24 elements: Al, P, S, Cl, K, Sr, Sc, Ti, Mn, Fe, Co, Cu, Zn, As, Br, Ba, La, Eu, Tb, Dy, Ta, Pb, Th, and U in Barbula indica moss collected at Baoloc (Vietnam) from November 2019 to March 2020. Factor analysis was used to explain contamination sources at the sampling sites. This study showed that the passive moss biomonitoring and TXRF techniques are efficient and very suitable for detecting trace elements due to atmospheric deposition in developing countries, especially Vietnam and some Asian countries.Trong nghiên cứu này, kỹ thuật huỳnh quang tia X phản xạ toàn phần (TXRF) được ứng dụng đã xác định được 24 nguyên tố, bao gồm: Al, P, S, Cl, K, Sr, Sc, Ti, Mn, Fe, Co, Cu, Zn, As, Br, Ba, La, Eu, Tb, Dy, Ta, Pb, Th, và U trên rêu Barbula Indica tại thành phố Bảo Lộc (Việt Nam) từ tháng mười một năm 2019 đến tháng ba năm 2020. Kết quả cũng đã dự đoán những nguồn ô nhiễm mang lại. Ở nghiên cứu này cho thấy việc sử dụng mẫu rêu có sẵn, và kỹ thuật TXRF là hiệu quả, rất thuận lợi để xác định sự lắng động các nguyên tố vết trong không khí cho những quốc gia đang phát triển, đặc biệt là Việt Nam và các nước Châu Á

    Thuật toán xác định tính chất mã của ngôn ngữ chính quy

    Get PDF
    We present an extension of the test proposed by Sardinas and Patterson (1953) for deciding whether a set of words is a code. As a consequence, we obtain an effective algorithm that decides in O(k){\cal O}(k) time whether a given regular language is a code, where kk is the finite index of the syntactic congruence of this language.Trong bài báo này, chúng tôi trình bày một thuật toán mới mở rộng thuật toán Sardinas-Patterson xác định tính chất mã của một ngôn ngữ. Từ đó nhận được một thuật toán với độ phức tạp cỡ O(k){\cal O}(k) để nhận biết một ngôn ngữ chính quy cho trước là mã hay không, với kk là chỉ số hữu hạn của tương đẳng cú pháp thỏa ngôn ngữ đó

    NGHIÊN CỨU TỐI ƯU HÓA QUÁ TRÌNH THỦY PHÂN CELLULOSE TÁCH TỪ RƠM RẠ THÀNH ĐƯỜNG TAN CỦA NÂM MỐC ASPERGILLUS TERRIUS ĐỂ SẢN XUẤT ETHANOL - NHIÊN LIỆU SINH HỌC

    Get PDF
    SUMMARY OPTIMIZATION OF THE CELLULOSE (FROM RICE STUBBLE/STRAW) HYDROLYSIS INTO GLUCOSE USING FUNGI ASPERGILLUS TERRIUS IN ETHANOL-BIOFUEL PRODUCTION The cellulose hydrolysis into glucose using Aspergillus terrius AF67 in ethanol-biofuel production was studied. By using the design of experiments with main factors (the concentrations of cellulose and enzyme) a regression equation was found. Based on this equation, the influent evaluation of two above factors on hydrolysis yield was implemented and with some supplementary experiments, the maximal yield was found:  ymax = 15.876 mg/ml. Keywords. Aspergillus terrius AF6

    COPPER HEXACYANOFERRATE (II): SYNTHESIS, CHARACTERIZATION, AND CESIUM, STRONTIUM ADSORBENT APPLICATION

    Get PDF
    Low-cost nanoscale copper hexacyanoferrate (CuHF), a good selective adsorbent for cesium (Cs+) removal, was prepared using the chemical co-precipitation method. Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), energy-dispersive X-ray spectroscopy (EDS), and high-resolution transmission electron microscopy (HR-TEM) were conducted to determine the CuHF morphology. Copper hexacyanoferrate, Cu13[Fe(CN)6]14.(2K).10H2O, has a cubic structure (space group F-43m) in the range of 10-30 nm and a Brunauer-Emmett-Teller (BET) surface area of 462.42 m2/g. The removal of Cs+ and Sr2+ is dependent on pH; the maximum adsorption capacity (qmax) of CuHF is achieved at a pH = 6. From the Langmuir model, qmax = 143.95 mg/g for Cs+ and 79.26 mg/g for Sr2+, respectively. At high concentrations, Na+, Ca2+, and K+ ions have very little effect on Cs+ removal, and Na+ and K+ ions have a higher affinity for removing Sr2+ than Ca2+ at all concentrations. CuHF has a high affinity for alkaline cations in the order: Cs+ > K+ > Na+ > Ca2+ > Sr2+, as proposed and discussed

    NGHIÊN CỨU SỬ DỤNG CO2 TỪ KHÍ THẢI ĐỐT THAN ĐỂ NUÔI VI TẢO SPIRULINA PLATENSIS

    Get PDF
    UTILIZATION OF CO2 CAPTURED FROM THE COAL-FIRED FLUE GAS FOR GROWING  SPIRULINA PLATENSIS SP4 The paper presents the results concerning the utilization of CO2 captured from the coal-fired flue gas for growing the  Spirulina platensis SP4 in laboratory condition. Several research results on the conversion of CO32- and HCO3- in algal suspension and CO2 intake efficiency by the alga were presented. The growth and  biomass quality of  Spirulina platensis SP4 using CO2 from fired-coal flue gas were equivalent to that of the alga grown in the pure CO2 experimental lot

    Bài tập quản trị tác nghiệp

    No full text
    279 tr. ; 21 cm
    corecore