Some characters of bacterial cellulases in goats' rumen elucidated by metagenomic DNA analysis and the role of fibronectin 3 module for endoglucanase function

Nguyen, Khanh Hoang Viet,Dao, Trong Khoa,Nguyen, Hong Duong,Nguyen, Khanh Hai,Nguyen, Thi Quy,Nguyen, Thuy Tien,Nguyen, Thi Mai Phuong,Truong, Nam Hai,Do, Thi Huyen Asian Australasian Association of Animal Productio 2021 Animal Bioscience Vol.34 No.5

Objective: Fibronectin 3 (FN3) and immunoglobulin like modules (Ig) are usually collocated beside modular cellulase catalytic domains. However, very few researches have investigated the role of these modules. In a previous study, we have sequenced and analyzed bacterial metagenomic DNA in Vietnamese goats' rumen and found that cellulase-producing bacteria and cellulase families were dominant. In this study, the properties of modular cellulases and the role of a FN3 in unique endoglucanase belonging to glycosyl hydorlase (GH) family 5 were determined. Methods: Based on Pfam analysis, the cellulases sequences containing FN3, Ig modules were extracted from 297 complete open reading frames (ORFs). The alkaline, thermostability, tertiary structure of deduced enzymes were predicted by AcalPred, TBI software, Phyre2 and Swiss models. Then, whole and truncated forms of a selected gene were expressed in Escherichia coli and purified by His-tag affinity column for assessment of FN3 ability to enhance enzyme activity, solubility and conformation. Results: From 297 complete ORFs coding for cellulases, 148 sequences containing FN3, Ig were identified. Mostly FN3 appeared in 90.9% beta-glucosidases belonging to glycosyl hydrolase family 3 (GH3) and situated downstream of catalytic domains. The Ig was found upstream of 100% endoglucanase GH9. Rarely FN3 was seen to be situated downstream of X domain and upstream of catalytic domain endoglucanase GH5. Whole enzyme (called XFN3GH5 based on modular structure) and truncate forms FN3, XFN3, FN3GH5, GH5 were cloned in pET22b (+) and pET22SUMO to be expressed in single and fusion forms with a small ubiquitin-related modifier partner (S). The FN3, SFN3 increased GH5 solubility in FN3GH5, SFN3GH5. The SFN3 partly served for GH5 conformation in SFN3GH5, increased modules interaction and enzyme-soluble substrate affinity to enhance SXFN3GH5, SFN3GH5 activities in mixtures. Both SFN3 and SXFN3 did not anchor enzyme on filter paper but exfoliate and separate cellulose chains on filter paper for enzyme hydrolysis. Conclusion: Based on these findings, the presence of FN3 module in certain cellulases was confirmed and it assisted for enzyme conformation and activity in both soluble and insoluble substrate.

The Impacts of Intellectual Property Rights on International Trade Flows in ASEAN Countries

Nguyen Khanh Doanh 대구대학교 경제경영연구소 2006 경제경영연구 Vol.4 No.1

This paper aims at analyzing the impact of intellectual property protection on international trade flows, using ASEAN as a case study. The finding of the paper could be summarized as follows. First, IPR protection is an important determinant of international trade flows. Overall, stronger protection of IPRs increases bilateral trade between ASEAN and the rest of the world. Second, IPR protection in the importing countries (the rest of the world) has positive effect on ASEAN's exports, indicating the market expansion effect. When the impacts of IPR protection are allowed to differ across sectors, stronger effects on exports are found in high tech sectors, such as chemicals and transport equipment and machinery. Third, IPR protection in ASEAN countries has negative effect on their imports from the rest of the world, exhibiting the market power effect. When the impacts of IPR protection are allowed to differ across sectors, strong effects on ASEAN's imports are found in such sectors as food and manufactured goods. Implications being derived from this study are summarized as followed. First, industrializing countries with strong imitative capacities tend to experience the market expansion effect as their IPR regimes become stronger, while for developing countries with weak imitative abilities, the effects of stronger IPR protection in these countries on their imports are ambiguous. Second, most industrializing countries are those which should expect the largest adjustment in domestic output and labor as their fringing production activities are replaced progressively by foreign imports.

An Analysis of the Effect of WiFi Scanning Interval and Pedestrian Walking Speed on Indoor Localization Performance

Khanh Nguyen-Huu(웡후칸),Seon-Woo Lee(이선우) 한국HCI학회 2019 한국HCI학회 학술대회 Vol.2019 No.2

Recently, in the field of indoor localization, wireless radio and dead reckoning techniques are two main branches that received much attention. The former one uses the wireless facility such as WiFi or Bluetooth to estimate the user position in two ways: triangulation and fingerprinting. The latter one uses the inertial sensors to estimate the displacement of the user based on the previous position. In this paper, from several experiments, we pointed out the effect of WiFi scanning interval and pedestrian walking speed to the positioning result. We also used the WiFi fingerprinting technique as a clue to compensate for the accumulated error of the pedestrian dead reckoning system which is implemented on a smartphone to analyze the effect of the two factors above.

Observer-based control for discrete-time Markovian jump systems

Khanh Hieu Nguyen(웬 칸 히에우),Sung Hyun Kim(김성현) 대한전기학회 2021 정보 및 제어 심포지엄 논문집 Vol.2021 No.10

AN INDEPENDENT RESULT FOR ATTACHED PRIMES OF CERTAIN TOR-MODULES

Khanh, Pham Huu Korean Mathematical Society 2015 대한수학회보 Vol.52 No.2

Let (R, m) be a Noetherian local ring, I an ideal of R, and A an Artinian R-module. Let $k{\geq}0$ be an integer and $r=Width_{>k}(I,A)$ the supremum of length of A-cosequence in dimension > k in I defined by Nhan-Hoang [8]. It is shown that for all $t{\leq}r$ the sets $$(\bigcup_{i=0}^{t}Att_R(Tor_i^R(R/I^n,A)))_{{\geq}k}\;and\\(\bigcup_{i=0}^{t}Att_R(Tor_i^R(R/(a_1^{n_1},{\cdots},a_l^{n_l}),A)))_{{\geq}k}$$ are independent of the choice of $n,n_1,{\cdots},n_l$ for any system of generators ($a_1,{\cdots},a_l$) of I.

Power Sharing Method for a Grid connected Microgrid with Multiple Distributed Generators

Khanh-Loc Nguyen,Dong-Jun Won,Seon-Ju Ahn,Il-Yop Chung 대한전기학회 2012 Journal of Electrical Engineering & Technology Vol.7 No.4

In this paper, a grid connected microgrid with multiple inverter-based distributed generators (DGs) is considered. DG in FFC mode regulates the microgrid as a controllable load from the utility point of view as long as its output is within the capacity limit. The transition mode causes a change in frequency of microgrid due to the loss of power transferred between main grid and microgrid. Frequency deviation from the nominal value can exceed the limit if the loss of power is large enough. This paper presents a coordinated control method for inverter-based DGs so that the microgrid is always regulated as a constant load from the utility viewpoint during grid connected mode, and the frequency deviation in the transition mode is minimized. DGs can share the load by changing their control modes between UPC and FFC and stabilize microgrid during transition.

Polystyrene nanoparticles prepared by nanoprecipitation: A recyclable template for fabricating hollow silica

Khanh B. Vu,Thanh Khoa Phung,Thao T.T. Tran,Clement Mugemana,Ha N. Giang,Truong Le Phuc Nhi 한국공업화학회 2021 Journal of Industrial and Engineering Chemistry Vol.97 No.-

Polystyrene was synthesized and applied as a template for fabricating hollow silica nanoparticles. Organic solvent and water were used as a solvent and an anti-solvent, respectively, to produce thepolystyrene nanoparticles via. nanoprecipitation technique. The influence of precipitation method (oneshotor drop), solvent for dissolution of polystyrene, and concentration of polystyrene or CTAB linker onthe diameter of polystyrene nanoparticles was investigated. The hollow silica nanoparticles werefabricated using the as-made polystyrene nanoparticles as a template with the help of CTAB linker. Polystyrene was recovered by the extraction of polystyrene@SiO2 composite with the tetrahydrofuransolvent, and the recovered polystyrene was re-used to make the polystyrene nanoparticles as a templatefor fabricating hollow silica nanoparticles. Our study can be applied for other types of polymericmaterials as long as those polymeric materials form nanoparticles via. nanoprecipitation technique. Incomparison with the polystyrene hard template prepared by emulsion polymerization, the size ofpolystyrene nanoparticles produced by the nanoprecipitation technique can be well-tuned by changingthe polystyrene and linker concentrations.

Barriers of Last Planner System: A Survey in Vietnam Construction Industry

Khanh, Ha Duy,Kim, Soo Yong Korea Institute of Construction Engineering and Ma 2013 Journal of construction engineering and project ma Vol.3 No.4

Construction industry is overwhelmed by delay and often has suffered cost and time overrun. In this context, Last Planner System (LPS) has been considered as a very useful tool for the management of the construction process. Many previous studies have reported its effectiveness in construction performance. This study aims to evaluate the level of importance of the Last Planner processes in the Vietnam construction industry (VCI), and analyze the existing barriers when implementing these processes in construction management. These barriers were collected based on previous studies from International Group for Lean Construction (IGLC). A survey was carried out through questionnaire. The respondents are been experienced people in construction project management. There are four processes of LPS that were investigated including master schedule, phase schedule, lookahead plan, and weekly work plan. The results showed that master schedule is the most important item when performing a construction project in the VCI. The highest degree of agreement belongs to 'owner - contractor' pair with 77.1% importance indices; whereas the lowest belongs to 'consultants - contractors' pair with 63.8% importance indices. Eventually, three barrier factors were extracted from factor analysis technique with 62.2% of variance explained.

Experimental and numerical study on the failure of sandwich T-joints under pull-off loading

Khanh-Hung Nguyen,Yong-Bin Park,Jin-Hwe Kweon,Jin-Ho Choi,Chang-Won Shul,Myung-Seog Yang,Seung-Moon Jun 한국항공우주학회 2012 International Journal of Aeronautical and Space Sc Vol.13 No.2

In this study, the failure mechanism of sandwich-to-laminate T-joints under pull-off loading was investigated by experiment and the finite element method. A total of 26 T-joint specimens were manufactured and tested in order to investigate the effects of both adhesive thickness (0.4, 2.0, and 4.0 ㎜) and environmental conditions on the failure of the joints. The results showed that failure occurred mainly as intralaminar failure in the first layer of the sandwich face, which was contacted to the paste adhesive. The failure load did not significantly change with increasing adhesive thickness in both RTD (Room Temperature and Dry) and ETW (Elevated Temperature and Wet) conditions. In the case of ETW conditions, however, the failure load increased slightly with an increase in adhesive thickness. The joints tested in ETW conditions had higher failure loads than those tested in RTD conditions. In addition to the experiment, a finite element analysis was also conducted to investigate the failure of the joint. The stress inside the first ply of the sandwich face was of interest because during the experiment, failure always occurred there. The analysis results showed good agreement with the trend of experimental results, except for the case of the smallest adhesive thickness. The highest stress was predicted in the regions where initial failure was observed in the experiment. The maximum stress was almost constant when the adhesive thickness was beyond 2 ㎜.

cis-Cyclooctene epoxidation catalyzed by bulk metallophthalocyanines, metallohexadecafluorophthalocyanines and hollow silica-supported metallohexadecafluorophthalocyanine

Khanh B. Vu,Thanh Khoa Phung 한국공업화학회 2016 Journal of Industrial and Engineering Chemistry Vol.40 No.-

We employed a variety of catalysts including metallophthalocyanines and metallohexadecafluor-ophthalocyanines for epoxidation of cis-cyclooctene in water as a green solvent. Manganesephthalocyanine and poly(copper phthalocyanine) are highly active while other metallophthalocyanines(Zn, Cu, Ni, Li) are nearly not active. Similarly, copper and cobalt hexadecafluorophthalocyanines showhighly catalytic activity, but zinc hexadecafluorophthalocyanine is inactive. Moreover, iron phthalocya-nine chloride is also a good catalyst while nickel phthalocyanine-tetrasulfonic acid tetrasodium is a poorcatalyst. Copper hexadecafluorophthalocyanine incorporated into hollow silica exhibits much bettercatalytic activity than bulk copper hexadecafluorophthalocyanine. This supported catalyst also gives astable conversion until the fourth cycle of reaction.