Effect of Crude Protein Levels in Concentrate and Concentrate Levels in Diet on In vitro Fermentation

Dung, Dinh Van,Shang, Weiwei,Yao, Wen Asian Australasian Association of Animal Productio 2014 Animal Bioscience Vol.27 No.6

The effect of concentrate mixtures with crude protein (CP) levels 10%, 13%, 16%, and 19% and diets with roughage to concentrate ratios 80:20, 60:40, 40:60, and 20:80 (w/w) were determined on dry matter (DM) and organic matter (OM) digestibility, and fermentation metabolites using an in vitro fermentation technique. In vitro fermented attributes were measured after 4, 24, and 48 h of incubation respectively. The digestibility of DM and OM, and total volatile fatty acid (VFA) increased whereas pH decreased with the increased amount of concentrate in the diet (p<0.001), however CP levels of concentrate did not have any influence on these attributes. Gas production reduced with increased CP levels, while it increased with increasing concentrate levels. Ammonia nitrogen ($NH_3$-N) concentration and microbial CP production increased significantly (p<0.05) by increasing CP levels and with increasing concentrate levels in diet as well, however, no significant difference was found between 16% and 19% CP levels. Therefore, 16% CP in concentrate and increasing proportion of concentrate up to 80% in diet all had improved digestibility of DM and organic matter, and higher microbial protein production, with improved fermentation characteristics.

Estimation of methane emissions from local and crossbreed beef cattle in Daklak province of Vietnam

Carlos Alberto Ramirez-Restrepo,Dung Van Tien,Ngoan Le Duc,Mario Herrero,Phung Le Dinh,Dung Dinh Van,Sen Le Thi Hoa,Cuong Vu Chi,Cesar Solano-Patino,Amy M. Lerner,Timothy D. Searchinger 아세아·태평양축산학회 2017 Animal Bioscience Vol.30 No.7

Objective: This study was aimed at evaluating effects of cattle breed resources and alternative mixed-feeding practices on meat productivity and emission intensities from household farming systems (HFS) in Daklak Province, Vietnam. Methods: Records from Local Yellow×Red Sindhi (Bos indicus; Lai Sind) and 1/2 Limousin, 1/2 Drought Master, and 1/2 Red Angus cattle during the growth (0 to 21 months) and fattening (22 to 25 months) periods were used to better understand variations on meat productivity and enteric methane emissions. Parameters were determined by the ruminant model. Four scenarios were developed: (HFS1) grazing from birth to slaughter on native grasses for approximately 10 h plus 1.5 kg dry matter/d (0.8% live weight [LW]) of a mixture of guinea grass (19%), cassava (43%) powder, cotton (23%) seed, and rice (15%) straw; (HFS2) growth period fed with elephant grass (1% of LW) plus supplementation (1.5% of LW) of rice bran (36%), maize (33%), and cassava (31%) meals; and HFS3 and HFS4 computed elephant grass, but concentrate supplementation reaching 2% and 1% of LW, respectively. Results: Results show that compared to HFS1, emissions (72.3±0.96 kg CH4/animal/life; least squares means± standard error of the mean) were 15%, 6%, and 23% lower (p<0.01) for the HFS2, HFS3, and HFS4, respectively. The predicted methane efficiencies (CO2eq) per kg of LW at slaughter (4.3±0.15), carcass weight (8.8±0.25 kg) and kg of edible protein (44.1±1.29) were also lower (p<0.05) in the HFS4. In particular, irrespective of the HSF, feed supply and ratio changes had a more positive impact on emission intensities when crossbred 1/2 Red Angus cattle were fed than in their crossbred counterparts. Conclusion: Modest improvements on feeding practices and integrated modelling frameworks may offer potential trade-offs to respond to climate change in Vietnam.

Polarization dependence of the metamagnetic resonance of cut-wire-pair structure by using plasmon hybridization

Van Dung, Nguyen,Yoo, YoungJoon,Lee, YoungPak,Tung, Nguyen Thanh,Tung, Bui Son,Lam, Vu Dinh 한국물리학회 2014 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol. No.

Synthesis of Carbon Nanotubes on Steel Foils

Nguyen Van Chuc,Nguyen Duc Dung,Phan Ngoc Hong,Le Dinh Quang,Phan Hong Khoi,Phan Ngoc Minh 한국물리학회 2008 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.52 No.5

Carbon nanotubes (CNTs) were synthesized by using a thermal chemical vapor deposition (CVD) at 800 ℃ in a mixture of C₂H₂, H₂ and N₂ gases with steel foils as both catalysts and substrates. More than 2 grams of CNTs were grown on approximately 7 grams of steel foil with a 0.5 cm² surface area after 30 minutes of growth. The effects of CVD parameters, such as the growth temperature and the deposition time, on the size and the morphology of the CNTs were studied using scanning electron microscopy (SEM). We found that the optimized temperature and growth time for having high quality CNTs were 800 ℃ and 30 minutes, respectively. The purity of the CNTs was evaluated by using thermogravimetric analysis (TGA) and the result showed that the carbon content was approximately 93 wt.%. The graphite crystallinity of the CNTs was analyzed by using Raman spectroscopy. The steel foil was found to maintain its catalytic behavior after several growths. The technique holds great promise for use in mass production (approximately 120 grams CNTs per day) with signicantly reduced cost. Carbon nanotubes (CNTs) were synthesized by using a thermal chemical vapor deposition (CVD) at 800 ℃ in a mixture of C₂H₂, H₂ and N₂ gases with steel foils as both catalysts and substrates. More than 2 grams of CNTs were grown on approximately 7 grams of steel foil with a 0.5 cm² surface area after 30 minutes of growth. The effects of CVD parameters, such as the growth temperature and the deposition time, on the size and the morphology of the CNTs were studied using scanning electron microscopy (SEM). We found that the optimized temperature and growth time for having high quality CNTs were 800 ℃ and 30 minutes, respectively. The purity of the CNTs was evaluated by using thermogravimetric analysis (TGA) and the result showed that the carbon content was approximately 93 wt.%. The graphite crystallinity of the CNTs was analyzed by using Raman spectroscopy. The steel foil was found to maintain its catalytic behavior after several growths. The technique holds great promise for use in mass production (approximately 120 grams CNTs per day) with signicantly reduced cost.

Synthesis of Nano Titanium Dioxide and Its Application in Photocatalysis

Truong Van Chuong,Le Quang Tien Dung,Dinh Quang Khieu 한국물리학회 2008 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.52 No.5

This paper presents a simple way to synthesize titaniumdioxide nanotubes by using a microwave- assisted reaction of TiO2 particles and NaOH solution. The main advantage of the introduction of microwave into the reaction system is the extremely rapid kinetics for synthesis. This method is simple and easy to reproduce. Structural and microstructural characterizations of titania nanotubes were accomplished using X-ray diffraction (XRD), scanning-electron microscopy (SEM) and transmission-electron microscopy (TEM) techniques. The specific surface area was calculated using the Brunauer-Emmett-Teller model and was found to be 52 m2/g. A high photocatalysis of our TiO2 nanotubes was obtained. This paper presents a simple way to synthesize titaniumdioxide nanotubes by using a microwave- assisted reaction of TiO2 particles and NaOH solution. The main advantage of the introduction of microwave into the reaction system is the extremely rapid kinetics for synthesis. This method is simple and easy to reproduce. Structural and microstructural characterizations of titania nanotubes were accomplished using X-ray diffraction (XRD), scanning-electron microscopy (SEM) and transmission-electron microscopy (TEM) techniques. The specific surface area was calculated using the Brunauer-Emmett-Teller model and was found to be 52 m2/g. A high photocatalysis of our TiO2 nanotubes was obtained.

Rapid and label-free detection of H5N1 virus using carbon nanotube network field effect transistor

Vu Van Thu,Phuong Dinh Tam,Phuong Trung Dung 한국물리학회 2013 Current Applied Physics Vol.13 No.7

DNA hybridization-based detection techniques are widely used in genetics, medicine, and drug discovery. However, the current techniques are usually based on labels and reagents that are time consuming and complex to implement. In this study, we report a label-free DNA sensor based on single-walled carbon nanotube field effect transistor (SWCNTFET) for selective DNA hybridization detection of H5N1 virus. A network of single-walled carbon nanotubes (SWCNTs) acts as the conductor channel. ProbeDNA sequences were adsorbed onto SWCNTs. The developed DNA sensor can effectively detect full-complementary DNA with concentration as low as 1.25 pM. The sensitivity of the DNA sensor reached approximately 0.28 nM/nA. The effect of the parameters, including DNA probe concentration, its complementary concentration,mismatched sequence, and hybridization time, on the sensor response was also studied. The results showed the potential application of the DNA sensor for medical, environmental, and epidemic detection.

Polarization Dependence of the Metamagnetic Resonance of Cut-wire-pair Structure by Using Plasmon Hybridization

Nguyen Van Dung,유영준,이영백,Nguyen Thanh Tung,Bui Son Tung,Vu Dinh Lam 한국물리학회 2014 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.65 No.1

The influence of lattice constants on the electromagnetic behavior of a cut-wire-pair (CWP)structure has been elucidated. In this report, we performed both simulations and experiments todetermine the influence of polarization on the metamagnetic resonance of the CWP structure. Thekey finding is the result of an investigation on the plasmon hybridization between the two CWs,which showed that the polarization of the incident wave was affected. Good agreement betweennumerical simulation and measurement is achieved.

Metamaterial Perfect Absorber Using the Magnetic Resonance of Dielectric Inclusions

Nguyen Van Dung,Bui Son Tung,Bui Xuan Khuyen,Young Joon Yoo,YoungPak Lee,Joo Yull Rhee,Vu Dinh Lam 한국물리학회 2016 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.68 No.8

In this report, we introduce a stable metamaterial perfect absorber at GHz frequency based on a novel design of a Mie-type resonance. A single perfect absorption peak is achieved at 9.54 GHz, and the influence of the structural parameters on the absorption behavior is studied; the results were consistent with dielectric-resonator theory. The absorption is demonstrated to be polarizationinsensitive; furthermore, the absorber structure can work for a wide incident angle without any change in the resonance peak. Our absorber structure can also control 47% of the resonance peak’s position by changing the temperature of the dielectric layer. Our absorber structure can also be applied as an electromagnetic-wave absorber for wide-incident-angle, thermally-controllable devices.

Photocatalytic removal of Rhodamine B in water using g-C3N4/MIL-53(Fe) material under LED visible light with persulfate activation

Nguyen Trung Dung,Nguyen Van Hiep,Manh B. Nguyen,Vu Dinh Thao,Nguyen Nhat Huy 한국화학공학회 2021 Korean Journal of Chemical Engineering Vol.38 No.10

Photocatalysis is usually considered as one of the most effective methods for treating non-biodegradable pollutants commonly found in textile wastewater. In this study, the photocatalyst of g-C3N4/MIL-53(Fe) was synthesized by the hydrothermal method and applied for the removal of Rhodamine B (RhB) in water. The photocatalytic material was characterized by X-ray diffraction, Fourier-transform infrared spectroscopy, scanning electron microscopy, energy-dispersive X-ray spectroscopy, Brunauer-Emmett-Teller analysis, UV-Vis diffuse reflectance spectroscopy, and X-ray photoelectron spectroscopy. The results showed that the g-C3N4 doped MIL-53(Fe) with 97 wt% of MIL- 53(Fe) works effectively under visible light and the presence of oxidants (Na2S2O8). RhB removal efficiency can be more than 99% with 20mg/L of RhB, 300mg/L of catalyst, 200mg/L of Na2S2O8, and pH 3. In addition, the photocatalytic degradation mechanism of RhB with g-C3N4/MIL-53(Fe) was also proposed, which could be improved and studied for a wide range of applications in textile wastewater treatment.

Improvement of Gamma-amino Butyric Acid Production by an Overexpression of Glutamate Decarboxylase from Pyrococcus horikoshii in Escherichia coli

Le Vo, Tam Dinh,Pham, Van Dung,Ko, Ji-Seun,Lee, Seung Hwan,Park, Si Jae,Hong, Soon Ho 한국생물공학회 2014 Biotechnology and Bioprocess Engineering Vol.19 No.2

In this study, the effect of glutamate decarboxylase from Pyrococcus horikoshii on gamma-aminobutyric acid (GABA) production was investigated in Escherichia coli for the first time. E. coli with overexpressed P. horikoshii glutamate decarboxylase was cultured at various pH levels and temperatures to determine the optimum conditions for GABA production. The highest final GABA concentration, 5.07 g/L, was obtained from 10 g/L of monosodium glutamate (MSG) with a GABA yield of 83% at $30^{\circ}C$ and pH 3.5. When P. horikoshii glutamate decarboxylase was introduced into a GABA aminotransferase knock-out E. coli XBT strains, 5.69 g/L of GABA was produced with a GABA yield of 93%.