• Title/Summary/Keyword: CuInS$_2$

Search Result 2,281, Processing Time 0.032 seconds

Comparative Study on Distribution of Heavy Metals of the Surface Sediments in East/West Oceanic Dumping Areas (동/서해병 해역 표층 퇴적물의 중금속 분포 특성 비교)

  • Kim, Pil-Geun;Park, Maeng-Eon;Sung, Kyu-Youl;Lim, Sung-Taek;Oh, Sul-Mi
    • Economic and Environmental Geology
    • /
    • v.42 no.2
    • /
    • pp.121-131
    • /
    • 2009
  • The distribution characteristics of heavy metals for surface sediments in east oceanic dumping area (EDA) and west oceanic dumping area (WDA) are evaluated by grain sizes, minerals, sedimentation rates and compositions of heavy metals. The mean grain sizes in EDA and WDA range from $7.95{\Phi}$ to $8.51{\Phi}$ and $7.42{\Phi}$ to $8.15{\Phi}$, respectively. These are mostly belonging to the M (mud) type. Minerals in the surface sediments consist of illite with chlorite, smectite, and kaolinite. Sedimentation rates estimated by $^{210}Pb$ method in EDA and WDA are 1.11 mm/yr$\sim$1.73 mm/yr and 1.87 mm/yr, respectively. According to the interrelationship, concentrations of Ni, Cu, Cr, and Zn are closely associated with mean grain size, Al, and Fe, whereas concentrations of Cd and Pb are poorly associated with ones. The enrichment factors of these elements are higher than 1.5, suggesting that the concentrations of Cd and Pb in the surface sediments are affected by anthropogenic sources. The $I_{geo}$-class numbers of Cd and Pb in the surface sediments are mostly classified in 2 to 4, showing moderate to strongly polluted. These numbers in EDA are higher than that of WDA, and the highest number is 4, indicative of the strongly polluted class. Our results show that the disposed wastes at EDA include mineralogical wastes, dredged materials from sewage disposals, and sludges from constructions having materials of WDA. The annual amount of oceanic dumping in EDA is double than that in WDA.

Fate of Heavy Metals in Activated Sludge: Sorption of Heavy Metal ions by Nocardia amarae

  • Kim, Dong-wook
    • Proceedings of the Korean Environmental Sciences Society Conference
    • /
    • 1998.10a
    • /
    • pp.2-4
    • /
    • 1998
  • Proliferation of Nocardia amarae cells in activated sludge has often been associated with the generation of nuisance foams. Despite intense research activities in recent years to examine the causes and control of Nocardia foaming in activated sludge, the foaming continued to persist throughout the activated sludge treatment plants in United States. In addition to causing various operational problems to treatment processes, the presence of Nocardia may have secondary effects on the fate of heavy metals that are not well known. For example, for treatment plants facing more stringent metal removal requirements, potential metal removal by Nocardia cells in foaming activated sludge would be a welcome secondary effect. In contrast, with new viosolid disposal regulations in place (Code o( Federal Regulation No. 503), higher concentration of metals in biosolids from foaming activated sludge could create management problems. The goal of this research was to investigate the metal sorption property of Nocardia amarae cells grown in batch reactors and in chemostat reactors. Specific surface area and metal sorption characteristics of N. amarae cells harvested at various growth stages were compared. Three metals examined in this study were copper, cadmium and nickel. Nocardia amarae strain (SRWTP isolate) used in this study was obtained from the University of California at Berkeley. The pure culture was grown in 4L batch reactor containing mineral salt medium with sodium acetate as the sole carbon source. In order to quantify the sorption of heavy metal ions to N amarae cell surfaces, cells from the batch reactor were harvested, washed, and suspended in 30mL centrifuge tubes. Metal sorption studies were conducted at pH 7.0 and ionlc strength of 10-2M. The sorption Isotherm showed that the cells harvested from the stationary and endogenous growth phase exhibited significantly higher metal sorption capacity than the cells from the exponential phase. The sequence of preferential uptake of metals by N. amarae cells was Cu>Cd>Ni. The specific surFace area of Nocardia cells was determined by a dye adsorption method. N.amarae cells growing at ewponential phase had significantly less specific surface area than that of stationary phase, indicating that the lower metal sorption capacity of Nocardia cells growing at exponential phase may be due to the lower specific surface area. The growth conditions of Nocardia cells in continuous culture affect their cell surface properties, thereby governing the adsorption capacity of heavy metal. The comparison of dye sorption isotherms for Nocardia cells growing at various growth rates revealed that the cell surface area increased with increasing sludge age, indicating that the cell surface area is highly dependent on the steady-state growth rate. The highest specific surface area of 199m21g was obtained from N.amarae cell harvested at 0.33 day-1 of growth rate. This result suggests that growth condition not only alters the structure of Nocardia cell wall but also affects the surface area, thus yielding more binding sites of metal removal. After reaching the steady-state condition at dilution rate, metal adsorption isotherms were used to determine the equilibrium distributions of metals between aqueous and Nocardia cell surfaces. The metal sorption capacity of Nocardia biomass harvested from 0.33 day-1 of growth rate was significantly higher than that of cells harvested from 0.5- and 1-day-1 operation, indicatng that N.amarae cells with a lower growth rate have higher sorpion capacity. This result was in close agreement with the trend observed from the batch study. To evaluate the effect of Nocardia cells on the metal binding capacity of activated sludge, specific surface area and metal sorption capacity of the mixture of Nocardia pure cultures and activated sludge biomass were determined by a series of batch experiments. The higher levels of Nocardia cells in the Nocardia-activated sludge samples resulted in the higher specific surface area, explaining the higher metal sorption sites by the mixed luquor samples containing greater amounts on Nocardia cells. The effect of Nocardia cells on the metal sorption capacity of activated sludge was evaluated by spiking an activated sludge sample with various amounts of pre culture Nocardia cells. The results of the Langmuir isotherm model fitted to the metal sorption by various mixtures of Nocardia and activated sludge indicated that the mixture containing higher Nocardia levels had higher metal adsorption capacity than the mixture containing lower Nocardia levels. At Nocardia levels above 100mg/g VSS, the metal sorption capacity of activate sludge increased proportionally with the amount of Noeardia cells present in the mixed liquor, indicating that the presence of Nocardia may increase the viosorption capacity of activated sludge.

  • PDF

Reflectance and Microhardness Characteristics of Sulfide Minerals from the Sambong Copper Mine (삼봉동광산산(三峰銅鑛山産) 유화광물(硫化鑛物)의 반사도(反射度)와 미경도(微硬度) 특성(特性))

  • Chi, Se Jung
    • Economic and Environmental Geology
    • /
    • v.17 no.2
    • /
    • pp.115-139
    • /
    • 1984
  • The Cu-Pb-Zn-Ag hydrothermal vein-type deposits which comprise the Sambong mine occur within calc-alkaline volcanics of the Cretaceous Gyeongsang Basin. The ore mineralization took place through three distinct stages of quartz (I and II stages) and calcite veins (III stage) which fill the pre-existing fault breccia zones. These stages were separated in time by tectonic fracturing and brecciation events. The reflection variations of one mineral depending on mineralization sequence are considered to be resulted from variation in its chemical composition due to different physico-chemical conditions in the hydrothermal system. The reflection power of sphalerite increases with the content of Fe substituted for Zn. Reflectances of the sphalerite grain are lower on (111) than on (100) surface. The spectral profiles depend on the internal reflection color. Sphalerite, showing green, yellow and reddish brown internal reflection, have the highest reflection power at $544m{\mu}$ (green), $593m{\mu}$ (yellow) and $615m{\mu}$ (red) wavelength, respectively. Chalcopyrite is recognized as biaxial negative from the reflectivity data of randomly oriented grains measured at the most sensitivity at $544m{\mu}$. The microindentation hardness against the Fe content (wt. %) for the sphalerite increases to 8.05% Fe and then decreases toward 9.5% Fe content. Vickers hardness of the sphalerite is considerably higher on surface of (100) than on (111). The relationship between Vickers hardness and crystal orientation of the galena was determined to be $VHN_{(111)}$ > $VHN_{(210)}$ > $VHN_{(100)}$. The softer sulfides have the wider variation of the diagonal length in the indentation. Diagonal length in the indentation is pyrite

  • PDF

Liquid-Composting Conditions of By-product Obtained from Degradation of Animal Carcass for Agriculture Recycling (폐가축사체의 농업적 재활용을 위한 가축사체 액상부산물의 액비화 조건 구명)

  • Seo, Young-Jin;Seo, Dong-Cheol;Kang, Se-Won;Lee, Sang-Gyu;Park, Ju-Wang;Choi, Ik-Won;Sung, Hwan-Hoo;Kang, Seog-Jin;Cho, Ju-Sik
    • Korean Journal of Environmental Agriculture
    • /
    • v.32 no.4
    • /
    • pp.348-354
    • /
    • 2013
  • BACKGROUND: Globally, concern about emerging infectious diseases of livestock is growing. For the disposal of the animal carcass, it is necessary to recycle the carcass into an agriculturally usable product. The objective of this study was to investigate the composting conditions of liquid by-product obtained from degradation of animal carcass. METHODS AND RESULTS: Optimum conditions of liquid fertilizer were investigated using different microorganisms, pHs, and volumes of microorganisms (Lactobacillus rhamnosus+Pichia deserticola). Based on the results from the optimum conditions, compost maturity and quality of liquid fertilizer were evaluated for 112 days. The compost maturity of liquid fertilizer were higher in the order of LP(Lactobacillus rhamnosus + Pichia deserticola) > BC(Bacillus cereus) > BS(Bacillus subtilis). The optimum condition under different volumes of LP was injection of 0.5 mL/100 mL. The compost maturity under different pHs were higher in the order of pH 7 > $$5{\geq_-}9{\frac{._-}{.}}11$$. The liquid by-product at 56 days after composting was completely decomposed. The concentrations of T-N, T-P and $K_2O$ in liquid fertilizer at 56 days were 0.94, 0.17 and 3.78%, respectively, and the sum of those concentrations was 4.89%. CONCLUSION(S): Liquid fertilizer of by-product using pig carcass was decomposed with optimum conditions(LP, pH 7, injection of 0.5 mL/100 mL) in 56 days after composting, and was suitable for official standard of commercial fertilizer.

Studies on the Constituents of Gynostemma pentaphyllum Makino (덩굴차(Gynostemma pentaphylum Makino)의 성분에 관한 연구)

  • Lee, Heon-Ok;Ko, Young-Su
    • Korean journal of food and cookery science
    • /
    • v.6 no.4 s.13
    • /
    • pp.69-83
    • /
    • 1990
  • Gynostemma pentaphyllum Makino is a kind of perennial liana plant belonging to the Cucurbitaceae family. Since it was first discovered and reported to the Japanese academy in 1977, it came to be widely known to China and Southeast Asia areas as well as Japan. In Korea its name began to appear in the first half of 1980's, and it is now being nationwidely cultivated and popularized as tea stuffs. Gynostemma pentaphyllum Makino has remarkably strong propagation power. In addition. since it contains a great quantity of beneficial components, especially saponin it is believed to have excellent medical effects, too. This study was undertaken to examine the value of Gynostemma pentaphyllum Makino as a health-promotint tea, by investigating the components creating the flaver of tea and the saponin ingredient making medical effects as well as by inspecting whether Gynostemma pentaphyllum Makino products show different component arrangements according to their growing districts. As raw materials of the experiment, three kinds of Gynostemma pentaphyllum Makino samples produced in Suwon, Geochang and Uleungdo were taken. To accomplish the formerly stated goals, the contained quantity of the proximate composition, free sugar, reducing sugar, free amino acid, minerals, tannin, caffeine and vitamin C were measured respectively and compared between the samples, while the saponin content was compared with heat extracted from panax ginseng. The results of the experiment are as follows: 1. In the case of the proximate composition, the crude fat content was the highest in the Gymostemma pentaphyllum Makino material from Geochang (1.62%), the second in that from Suwon (1.56%), and the lowest in that from Uleungdo (1.0%). In addition the Geochang: produced sample had the greatest quantity of the crude protein and ash contents: the order of the crude Protein content was the Geochang produced (17.83%), the Suwon-produced (15.87%), and the Uleungdo-produced(12.28%), while that of the ash content was the Geochang-produced (14.80%), the Uleungdo-produced(10.17%), and the Suwon-produced(9.34%). 2. As for the reducing sugar contents, the Suwon-produced scored the highest of the three (3.3%), while the Geochang-produced was 1.3% and the Uleungdo-produced 0.5%. The total content of free sugar was 1.07% (the Suwon-produced), and 0.49% (the Geochang-produced) respectively but the sample from Uleungdo showed almost no free sugar content. The contained quantity of fructose and glucose was the highest among the kinds of free sugar both in the Suwon-produced and in the Geochang-produced. 3. The content of amino acid was the highest in the Suwon-produced(1.41%), the second in the Geochang-produced(1.37%), and the lowest in the Uleungdo-produced(0.53%). In the experiment, sixteen kinds of amino acid were extracted-Asp. Thr. Ser. Glu. Gly. Ala. Val. Het. Ileu. Leu. Tyr. Phe. Lys. His. Arg. Try. All of them except glutamic acid and methionine showed the highest quantity score in the Suwon-produced, while the glutamic acid content was the higest in the Uleungdo-produced and the methionine content in the Geochang-produced. The sequential arrangement of the sixteen contents according to their magnitude ranged from glycine, aspartic acid, and glutamic acid (the highest) to tryptophan, serine and lysine (the lowest). 4. Ten kinds of mineral were detected-Ca, Mn, Cd, K, Na, Pb, Mg, Fe, Zn, Cu. Among them, the content of Cd, Na, Mg, Zn and Fe was the highest in the Geochang-produced and that of K in the Suwon-produced. 5. The Geochang-produced materials contained much a larger quantity of tannin (6.3%) than the Suwon-produced (2.6%). Neither caffeine nor vitamin C was detected in the three kinds of materials. 6. In the case of the saponin content the Geochang-produced showd 2.39%, the Uleungdo-produced 1.77% and the Suwon-produced 1.49% respectively. However, it was found also that the saponin content of Gymostemma pentaphyllum Makino was the same kind as that of panax ginseng.

  • PDF

Countermeasure and Outbreak Mechanism of Cochlodinium polykrikoides red tide 1. Environmental characteristics on outbreak and disappearanceof C. polykrikoides bloom (Cochlodinium polykrikoides 적조 발생기작과 대책 1. Cochlodinium polykrikoides 적조 발생과 소멸의 환경특성)

  • Park, Young-Tae;Kim, Young-Sug;Kim, Kui-Young;Park, Jong-Soo;Go, Woo-Jin;Jo, Yeong-Jo;Park, Seong-Yoon;Lee, Young-Sik
    • The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
    • /
    • v.6 no.4
    • /
    • pp.259-264
    • /
    • 2001
  • Typhoon and neap tide on Cochlodinium polykrikoides bloom and water temperature on disappearance of C. polykrikoides bloom were investigated to elucidate the outbreak mechanism of C. polykrikoides blooms at Naro and Namhae coastal area in South Sea of Korea. The first observation of C. polykrikoides blooms were observed when thermocline was disappeared by typhoon, tide, etc. The first blooms of C. polykrikoides were observed on neap tide or before one day from neap tide in 1996-1998 and 2000. However, thermocline was disappeared by typhoon in 1994 and 1999, the first blooms were observed early 12-30 day than 1996-1998 and 2000. The main reason of disappearance of C. polykrikoides blooms after typhoon on 1997-2000 seems to be other environmental change by typhoon rather than low water temperature. In the future, the first C. polykrikoides bloom will be appear around the first neap tide of latter part of August with breaking down of thermocline, but if the thermocline be collapsed by typhoon in July, the C. polykrikoides bloom will be appear at beginning of August. The outbreak of C. polykrikoides blooms will be explain as follows: The vegetative cells, which was germinated by environmental change or already exist in surface water at low level, input to the surface water, and then nutrients and trace metals which were suppled from out side of C. polykrikoides bloom area inflow to surface. The vegetative cells are growth by the nutrients and trace metals at suitable environmental conditions e.g. water temperature, salinity, and sufficient light.

  • PDF

Hazard Analysis for the Application of Good Agricultural Practices(GAP) on Paprika During Cultivation (파프리카의 농산물우수관리제도(GAP)적용을 위한 재배단계의 위해요소 분석)

  • Nam, Min-Ji;Chung, Do-Yeong;Shim, Won-Bo;Chung, Duck-Hwa
    • Journal of Food Hygiene and Safety
    • /
    • v.26 no.3
    • /
    • pp.273-282
    • /
    • 2011
  • This study established hazards which may cause risk to human at farm during cultivation stage of paprika. Samples of plants (paprika, leaf, stem), cultivation environments (water, soil), personal hygiene (hand, glove, clothes), work utensils (carpet, basket, box) and airborne bacteria were collected from three paprika farms (A, B, C) located in Western Gyeongnam, Korea. The collected samples were assessed for biological (sanitary indications and major foodborne pathogens), chemical (heavy metals, pesticide residues) and physical hazards. In biological hazards, total bacteria and coliform were detected at the levels of 1.9~6.6 and 0.0~4.610g CFU/g, leaf, mL, hand or 100 $cm^2$, while Escherichia coli was not detected in all samples. In major pathogens, only Bacillus cereus were detected at levels of ${\leq}$ 1.5 log CFU/g, mL, hand or 100 $cm^2$, while Staphylococuus aureus, Listeria monocytogenes, E. coli O157 and Salmonella spp. were not detected in all samples. Heavy metal and pesticide residue as chemical hazards were detected at levels below the regulation limit, physical hazard factors, such as insects, pieces of metal and glasses, were also found in paprika farms. Proper management is needed to prevent biological hazards due to cross-contamination while physical and chemical hazards were appropriate GAP criteria.

Growth Characteristic and Nutrient Uptake of Water Plants in Constructed Wetlands for Treating Livestock Wastewater (인공습지를 이용한 축산폐수처리장에서 수생식물의 생육특성과 영양염류 흡수특성)

  • Park, Jong-Hwan;Seo, Dong-Cheol;Kim, Seong-Heon;Lee, Choong-Heon;Choi, Jeong-Ho;Lee, Sang-Won;Lee, Dong-Jin;Ha, Yeong-Rae;Cho, Ju-Sik;Heo, Jong-Soo
    • Korean Journal of Environmental Agriculture
    • /
    • v.31 no.4
    • /
    • pp.351-358
    • /
    • 2012
  • BACKGROUND: Constructed wetlands for wastewater treatment are vegetated by wetland plants. Wetland plants are an important component of wetlands, and the plants have several roles in relation to the livestock wastewater treatment processes. The objectives of this study were to investigate the growth characteristics and nutrient absorption of water plants in constructed wetlands for treating livestock wastewater. METHODS AND RESULTS: In this study, livestock wastewater treatment plant by constructed wetlands consisted of $1^{st}$ water plant filtration bed, $2^{nd}$ activated sludge bed, $3^{rd}$ vertical flow(VF), $4^{th}$ horizontal flow(HF) and $5^{th}$ HF beds. Phragmites communis TRINIUS(PHRCO) was transplanted in $3^{rd}$ VF bed, Iris pseudoacorus L(IRIPS) was transplanted in $4^{th}$ HF bed and PHRCO, IRIPS and Typha orientalis PRESEL(THYOR) were transplanted in $5^{th}$ HF. Growth of water plants in constructed wetlands were the highest in October. The IRIPS growth was higher than other plant as 264 g/plant in October. The absorption of nitrogen and phosphorus by IRIS were 3.38 g/plant and 0.634 g/plant, respectively. The absorption of K, Ca, Mg, Na, Fe, Mn, Cu and Zn by water plants were higher in the order of IRIPS > THYOR > PHRCO. CONCLUSION(S): The absorption of nutrients by water plants were higher on the order of IRIPS > THYOR > PHRCO in constructed wetlands for treating livestock wastewater.

Quality Characteristics and Antioxidant Activity of Spirulina added Yogurt (스피루리나 첨가 요구르트의 품질 특성 및 항산화능)

  • Shin, Yu-Mi;Son, Chan-Wok;Sim, Hyun-Jung;Kim, Min-Hee;Kim, Mi-Yeon;Kwon, Oh-Yun;Kim, Mee-Ree
    • Korean journal of food and cookery science
    • /
    • v.24 no.1
    • /
    • pp.68-75
    • /
    • 2008
  • The aim of this study was to evaluate the quality characteristics and antioxidant activity of yogurt containing spirulina. Yogurt base was prepared from skim milk added with $0.25{\sim}1%(w/v)$ spirulina powder and fermented with lactic acid bacteria (S. thermophilus : L. bulgaricus = 1 : 1) at $40^{\circ}C$ for 12 hr. Kiwi puree and oligosaccharides were then added. The addition of 1% spirulina powder stimulated the growth of lactic acid bacteria, which showed the highest viable cell count ($3.4{\times}10^9$ CFU/mL), and increased the titratable acidity (1.10%). The viscosity range of the yogurt was 6,000 to 9,000 cP, and the sugar content of the yogurt was around 18 $^{\circ}Brix$. The antioxidant activities were determined using the DPPH method, and the hydroxyl radical scavenging activity of the yogurt containing spirulina was higher than that of the control. The sensory evaluation scores for appearance, odor, taste, overall acceptability and buying intention were higher in the yogurt containing 0.25% spirulina than in the other groups. The amount of macronutrients in the yogurt containing spirulina was higher than that in the control. In addition, the amounts of micronutrients in the yogurt containing spirulina was significantly increased. According to these results, the optimum concentration of spirulina powder is around 0.25%.

Territorial Expansion the King Võ (Võ Vương, 1738-1765) in the Mekong Delta: Variation of Tám Thực Chi Kế (strategy of silkworm nibbling) and Dĩ Man Công Man (to strike barbarians by barbarians) in the Way to Build a New World Order (무왕(武王, 1738-1765) 시기 메콩 델타에서의 영토 확장 추이: 제국으로 가는 길, '잠식지계(蠶食之計)'와 '이만공만(以蠻攻蠻)'의 변주)

  • CHOI, Byung Wook
    • The Southeast Asian review
    • /
    • v.27 no.2
    • /
    • pp.37-76
    • /
    • 2017
  • $Nguy{\tilde{\hat{e}}}n$ Cư Trinh has two faces in the history of territorial expansion of Vietnam into the Mekong delta. One is his heroic contribution to the $Nguy{\tilde{\hat{e}}}n$ family gaining control over the large part of the Mekong delta. The other is his role to make the eyes of readers of Vietnamese history be fixed only to the present territory of Vietnam. To the readers, $Nguy{\tilde{\hat{e}}}n$ Cư Trinh's achievement of territorial expansion was the final stage of the nam $ti{\acute{\hat{e}}n$ of Vietnam. In fact, however, his achievement was partial. This study pays attention to the King $V{\tilde{o}}$ instead of $Nguy{\tilde{\hat{e}}}n$ Cư Trinh in the history of the territorial expansion in the Mekong delta. King's goal was more ambitious. And the ambition was propelled by his dream to build a new world, and its order, in which his new capital, $Ph{\acute{u}}$ $Xu{\hat{a}}n$ was to be the center with his status as an emperor. To improve my assertion, three elements were examined in this article. First is the nature of $V{\tilde{o}}$ Vương's new kingship. Second is the preparation and the background of the military operation in the Mekong Delta. The nature of the new territory is the third element of the discussion. In 1744, six years after this ascending to the throne, $V{\tilde{o}}$ Vương declared he was a king. Author points out this event as the departure of the southern kingdom from the traditional dynasties based on the Red River delta. Besides, the government system, northern custom and way of dressings were abandoned and new southern modes were adopted. $V{\tilde{o}}$ Vương had enough tributary kingdoms such as Cambodia, Champa, Thủy $X{\tilde{a}}$, Hoả $X{\tilde{a}}$, Vạn Tượng, and Nam Chưởng. Compared with the $L{\hat{e}}$ empire, the number of the tributary kingdoms was higher and the number was equivalent to that of the Đại Nam empire of the 19th century. In reality, author claims, the King $V{\tilde{o}}^{\prime}s$ real intention was to become an emperor. Though he failed in using the title of emperor, he distinguished himself by claiming himself as the Heaven King, $Thi{\hat{e}}n$ Vương. Cambodian king's attack on the thousands of Cham ethnics in Cambodian territory was an enough reason to the King $V{\tilde{o}}^{\prime}s$ military intervention. He considered these Cham men and women as his amicable subjects, and he saw them a branch of the Cham communities in his realm. He declared war against Cambodia in 1750. At the same time he sent a lengthy letter to the Siamese king claiming that the Cambodia was his exclusive tributary kingdom. Before he launched a fatal strike on the Mekong delta which had been the southern part of Cambodia, $V{\tilde{o}}$ Vương renovated his capital $Ph{\acute{u}}$ $Xu{\hat{a}}n$ to the level of the new center of power equivalent to that of empire for his sake. Inflation, famine, economic distortion were also the features of this time. But this study pays attention more to the active policy of the King $V{\tilde{o}}$ as an empire builder than to the economic situation that has been told as the main reason for King $V{\tilde{o}}^{\prime}s$ annexation of the large part of the Mekong delta. From the year of 1754, by the initiative of $Nguy{\tilde{\hat{e}}}n$ Cư Trinh, almost whole region of the Mekong delta within the current border line was incorporated into the territory of $V{\tilde{o}}$ Vương within three years, though the intention of the king was to extend his land to the right side of the Mekong Basin beyond the current border such as Kampong Cham, Prey Vieng, and Svai Rieng. The main reason was $V{\tilde{o}}$ Vương's need to expand his territory to be matched with that of his potential empire with the large number of the tributary kingdoms. King $V{\tilde{o}}^{\prime}s$ strategy was the variation of 'silkworm nibbling' and 'to strike barbarians by barbarians.' He ate the land of Lower Cambodia, the region of the Mekong delta step by step as silkworm nibbles mulberry leave(general meaning of $t{\acute{a}}m$ thực), but his final goal was to eat all(another meaning of $t{\acute{a}}m$ thực) the part of the Mekong delta including the three provinces of Cambodia mentioned above. He used Cham to strike Cambodian in the process of getting land from Long An area to $Ch{\hat{a}}u$ Đốc. This is a faithful application of the Dĩ Man $C{\hat{o}}ng$ Man (to strike barbarians by barbarians). In addition he used Chinese refugees led by the Mạc family or their quasi kingdom to gain land in the region of $H{\grave{a}}$ $Ti{\hat{e}}n$ and its environs from the hand of Cambodian king. This is another application of Dĩ Man $C{\hat{o}}ng$ Man. In sum, author claims a new way of looking at the origin of the imperial world order which emerged during the first half of the 19th century. It was not the result of the long history of Đại Việt empires based on the Red River delta, but the succession of the King $V{\tilde{o}}^{\prime}s$ new world based on $Ph{\acute{u}}$ $Xu{\hat{a}}n$. The same ways of Dĩ Man $C{\hat{o}}ng$ Man and $T{\acute{a}}m$ Thực Chi $K{\acute{\hat{e}}}$ were still used by $V{\tilde{o}}^{\prime}s$ descendents. His grandson Gia Long used man such as Thai, Khmer, Lao, Chinese, and European to win another man the '$T{\hat{a}}y$ Sơn bandits' that included many of Chinese pirates, Cham, and other mountain peoples. His great grand son Minh Mạng constructed a splendid empire. At the same time, however, Minh Mạng kept expanding the size of his empire by eating all the part of Cambodia and Cham territories.