14C Dating at the Geological Boreholes and Sedimentory in the Lower Mekong Delta

This paper presents the processing and chemical treatment methods for age determination of geological samples using - Task Benzene Synthesizer - and the liquid scintillation analyzer (Tri–Carb 2770 TR/SL) in the laboratory at the Institute of Archaeology (VASS-Vietnam Academy Social Sciences). From that, 15 samples of wood, peat, mollusk shell collected from geological drilling holes LKBT1, LKBT2, LKBT3 at the coastal estuary in Ben Tre were processed and determined ages. The obtained results have helped to elucidate the sedimentation of the coastal estuary in Ben Tre province from the late Pleistocene to the present

Sự suy giảm của màng nhựa acrylic nhũ tương primal AC-261 trong môi trường thời tiết nhân tạo

The degradation of the Primal AC-261 water-based acrylic film (AC-261) in the artifical weathering environment has been studied by fourier-transform infrared (FTIR) and ultraviolet - visible (UV-Vis) spectroscopy, microscope and weight loss analysis. The IR and UV-Vis analysis showed that the level of C-H (alkanes) and C-O- (ester) stretchings decreased while O-H, C=O and C=C (alkene) stretchings increased in the artifical weathering testing process by a QUV weathering chamber equipped with UVB-313 fluorescent lamps and operated under wet-cycle conditions of 8 h UV irradiation at 60 °C, followed by 4 h of dark water condensation at 50 °C. After 96 cycles (1152 hours), the film surface had many black spots and weight loss of the film was 18 %

Nghiên cứu ảnh hưởng của xử lý plasma đến độ bám dính của lớp phủ khâu mạch quang trên nền polypropylen. Phần 1. Nghiên cứu ảnh hưởng của xử lý plasma không khí đến tính chất bề mặt polypropylen.

In this work, polypropylene (PP) was treated by air plasma to improve its adhesion properties. The influence of plasma treatment time was studied. As can be showed from results of static contact angle, the air plasma treatment improved significantly hydrophilic property of PP surface - the contact angle was reduced from 109 to 56o, respectively, before and after 3 minutes plasma treatment. In addition, Scanning Electron Microscope (SEM) images showed that after plasma treatment, the morphology of polymer surface saw rougher than before. The results of Fourier Transformed Infrared Spectroscopy (FT-IR) also presented that newly created hydrophilic functional groups (C=O, O-H) on the polypropylene surface caused by plasma treatment. As a result, the lap-shear strengths of PP after plasma treatment were substantially improved. As can be conclude from the results of this study, the suitable plasma treatment time for PP was 3 minutes

ĐẶC ĐIỂM QUẶNG HÓA VÀ KHOÁNG VẬT CÁC MỎ KẼM CHÌ KHU VỰC LÀNG HÍCH

Chemical and mineralogical characteristics of Zn-Pb ores in Lang Hich areaLang Hich ore deposit consisting of 6 mining places (West Metis, East Metis, Hang Chua, Bac Lau, Mo Ba - 1Aoven, Mo Ba - 1B) was discovered in 1905 and has been exploited since 1913. Anually, the mine have been exploited ~20000 T, inspite of lacking detail investigation in mineralogy and chemistry of ores.Two mineral assemblages have been clafsified in Lang Hich deposit as followed : 1) pyrite-galenite-sphalerite (Metis,Mo Ba), 2) galenite-sphalerite (Bac Lau, Hang Chua). Basically, sphalerites, have low Fe, In contents ; Bi is medium ; Mn and Cd is high, especially, Cd have very high content. While galenite contains Ag at economical value, besides, the presence of Sb is recored. Other investigation also shows the existing of tetraedrite group, an Ag bearing mineral group, and bournonite, a Sb bearing mineral