• Journal of the Korea Organic Resources Recycling Association
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• 제24권4호
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• pp.95-103
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• 2016

The objective of this study was to investigate feasibility of semi-dry anaerobic digestion using dairy cattle manure and to evaluate solidified fuel value of semi-dry anaerobic digestate. To evaluate semi-dry anaerobic digestion using dairy cattle manure, 950 mL bottle type anaerobic reactor was set in the constant temperature room maintained at $35^{\circ}C$. To produce anaerobic digestate for making solidified fuel, acrylic cylindrical anaerobic digester(1,000 mm width ${\times}$ 450 mm height) was set in the constant room temperature to carry out batch test of semi-dry anaerobic digestion using same dairy cattle manure. Moisture content of dairy cattle manure and inoculum solution for anaerobic digestion were 80.64% and 96.83%, respectively. The dairy cattle manure and the inoculum solution was mixed by 1:1 ratio(v/v) for anaerobic digestion. Water content and VS/TS(Volatile Solids/Total Solids) of mixture of substrate and inoculum were 89.74% and 83.35%, respectively. In case of non-inoculated anaerobic digester, the biogas was not produced. By the semi-dry anaerobic digestion, the calorific value of the digestate was reduced by 20% compare to fresh dairy cattle manure. In other hand, ash content increased from 15% to 18.4%. The contents of Cr, Pb, Cd and S of pellet produced from anaerobically digested dairy cattle manure were not against the standard regulation for livestock manure solidified fuel. Therefore, it can be used as fuel that anaerobic digestate produced after semi-dry anaerobic digestion using dairy cattle manure.

• Journal of the Korean Crystal Growth and Crystal Technology
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• 제13권3호
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• pp.122-126
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• 2003

In this study, $Zn_{0.86}Mn_{0.14}$Te epilayer of 0.7 $\mu\textrm{m}$-thickness was grown on GaAs(100) substrate by using hot wallepitaxy. GaAs(100) substrate was removed from $Zn_{0.86}Mn_{0.14}$Teepilayer by the selective etching solution. The crystal structure and the lattice constant of only Z $n_{0.86}$ M $n_{0.14}$Te epilayer were investigated to be zincblende and 6.140 $\AA$ from X-ray diffraction pattern, respectively. Mn composition x of $Zn_{1-x}Mn_x$Te epilayer was found to be 0.14 using this lattice constant and Vegard's law. The crystal quality of the epilayer was confirmed to be very good due to 256 arcsec-full-width at half-maximum of the double crystal rocking curve. The absorption spectra from the transmission ones were obtained to measure the band gap energy of $Zn_{0.86}Mn_{0.14}$Te epilayer from 300 K to 10 K. With the decreasing temperature,. strong absorption regions in the absorption spectra were shifted to higher energy side and the absorption peak meaning the free exciton formation appeared near the absorption edge. The band gap energy values of $Zn_{0.86}Mn_{0.14}$Te epilayer at 0 K and 300 K were found to be almost 2.4947 eV and 2.330 eV from the temperature dependence of the free exciton peak position energy of $Zn_{0.86}Mn_{0.14}$Te epilayer, respectively. The free exciton peak position energy of $Zn_{0.86}Mn_{0.14}$Te epilayer without GaAs substrate was larger 15.4 meV than photoluminescence peak position energy at 10 K. This energy difference between two peaks was analysed to be Stokes shift.

• Nuclear Engineering and Technology
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• 제5권1호
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• pp.38-43
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• 1973

The spin-rotation constants of the proton and tile fluorine nucleus in C $H_4$, Si $H_4$, Ge $H_4$, C $F_4$, Si $F_4$ and Ge $F_4$ were determined experimentally by the molecular beam magnetic resonance method. From the Hamiltonian and the high field approximation, the quantized energy level is given by the following equation. W $m_{I}$ $m_{J}$=- $g_{I}$ $m_{I}$H- $g_{J}$ $m_{J}$H- $C_{av}$ $m_{I}$ $m_{J}$, where $c_{av}$ is one third of the trace of the C tensor. In the nuclear resonance experiment, the proton and the fluorine nuclear resonance curves consist of many unresolved lines given by v=- $g_{J}$H- $C_{av}$ $m_{I}$, and a Gaussian approximation is made to correlate $c_{av}$ to the experimentally obtained half-width of the resonance curve. In the rotational resonance experiment, the five resonance peaks as predicted by v=- $g_{I}$H- $c_{av}$ $m_{I}$, $m_{I}$=0, $\pm$1 and $\pm$2, were all observed. The magnitude of car was determined by measuring the frequency distance between two adjacent peaks. The sign of $c_{av}$ was determined by the side peak suppression technique. The technique is described, and the sign and magnitude of the spin-rotation constant cav are summarized as following: for C $H_4$ -10.3$\pm$0.4tHz(from the rotational resonance), for SiH +3.71$\pm$0.08kHz(from the nuclear resonance), for Ge $H_4$+3.79$\pm$0.13kHz(from the nuclear resonance), for C $F_4$, -6.81$\pm$0.08kHz(from the rotational resonance), for Si $F_4$, -2.46$\pm$0.06kHz(from the rotational resonance), and finally for Ge $F_4$-1.84$\pm$0.04kHz(from the rotational resonance).onal resonance).esonance).

• Radiation Oncology Journal
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• 제15권4호
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• pp.393-402
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• 1997

Purpose : When an x-ray beam of small field size is irradiated to target area containing an air cavity, such as larynx, the underdosing effect is observed in the region near the interfaces of air and soft tissue. With a larynx model, air cavity embedded in tissue-equivalent material, this study is intonded for examining Parameters, such as beam quality, field size, and cavity size, to affect the dose distribution near the air cavity. Materials and Methods : Three x-rar beams, 4-, 6- and 10-MV, were employed to Perform a measurement using a 2cm $(width){\times}L$ (length in cm, one side of x-ray field used 2cm (height) air cavity in the simulated larynx. A thin window parallel-plate chamber connected to an electrometer was used for a dosimetry system. A ratio of the dose at various distances from the cavity-tissue interface to the dose at the same points in a homogeneous Phantom (ebservedlexpected ratio, O/E) normalized buildup curves, and ratio of distal surface dose to dose at the maximum buildup depth were examined for various field sizes. Measurement for cavity size effect was performed by varying the height (Z) of the air cavity with the width kept constant for several field sizes. Results : No underdosing effect for 4-MV beam for fields larger than $5cm\times5cm$ was found For both 6- and 10-MV beams, the underdosing portion of the larynx at the distal surface was seen to occur for small fields, $4cm\times4cm\;and\;5cm\times5cm$. The underdosed tissue was increased in its volume with beam energy even for similar surface doses. The relative distal surface dose to maximum dose was changed to 0.99 from 0.95, 0.92, and 0.91 for 4-, 6-, and 10-MV, respectively, with increasing field size, $4cm\times4cm\;to\;8cm\times8cm$, For 6- and 10-MV beams, the dose at the surface of the cavity is measured less than the predicted by about two and three percent. respectively. but decrease was found for 4-MV beam for $5cm\times5cm$ field. For the $4cm\timesL\timesZ$ (height in cm). varying depth from 0.0 to 4.8cm, cavity, O/E> 1.0 was observed regardless of the cavity size for any field larger than about $8cm\times8cm$. Conclusion : The magnitude of underdosing depends on beam energy, field size. and cavity size for the larynx model. Based on the result of the study. caution must be used when a small field of a high quality x-ray beam is irradiated to regions including air cavities. and especially the region where the tumor extends to the surface. Low quality beam. such as. 4-MV x-ray, and larger fields can be used preferably to reduce the risk of underdosing, local failure. In the case of high quality beams such as 6- and 10-MV x-rays, however. an additional boost field is recommended to add for the compensation of the underdosing region when a typically used treatment field. $8cm\times8cm$, is employed.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• 제39권3호
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• pp.197-210
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• 2003

The non-float midwater pair trawl was effective in the mouth opening and control of the working depth in midwater and bottom. In contrast, we confirmed that it was difficult to keep the net at surface above 30 m of the depth by means of the full scale experiment in the field and the model test in the circulation water channel. To solve this problem, the kites were attached to the head rope of the non-float midwater pair trawl. In this study, four kinds of the model experiments were carried out with the purpose of applying the kite to the korean midwater pair trawl. The results obtained can be summarized as follows: 1. The working depth of the non-float midwater pair trawl with the kite was shallower than that of the proto type and non-float type. The working depth of the kite type was approximately 20m with 2 kites and about 5m with 4 kites under 4.0 knot. The working depth was almost constant but the depth of the head rope sank approximately 15m and 10m according to the increase in the front weight and the wing-end weight, respectively. The changing aspect of the working depth was constant, but the depth of the head rope sank approximately 22m according to the increase in the lower warp length (dL). 2. The hydrodynamic resistance of the kite type was almost increased in a linear form in accordance with the flow speed increase from 2.0 to 5.0 knot. The increasing grate of the hydrodynamic resistance tended to increase in accordance with the increase in flow speed. The hydrodynamic resistance of the kite type was larger approximately 5～10 ton larger than that of the non-float type and the proto type. The hydrodynamic resistance of the kite type increased approximately 3ton with the changing of the front weight from 1.40 to 3.50 ton and approximately 4 ton with the changing of the wing-end weight from 0 to 1.11 ton and approximately 5.5 ton with the changing lower warp length (dL) from 0 to 40 m, respectively. 3. The net height of the kite type was increased approximately 10 m with the change in the kite area from $2,270mm^2$ to 4,540 $\textrm{mm}^2$. The net height of the kite type was aproximately 50 m and 30 m larger than that of the proto type and the non-float type, respectively. The changed aspect of the net width was approximately 5m with the variation of the flow speed from 2.0 to 5.0 knot. 4. The filtering volume of the kite type was larger than that of the proto type and the non-float type by 28%, 34% at 2.0 knot of the flow speed and 42%, 41% at 3.0 knot, and 62%, 45% at 4.0 knot, and 74%, 54% at 5.0knot, respectively. The optimal towing speed was approximately 3.0 knot for the proto type and was over 4.0 knot for the non-float type, and the optimal towing speed reached 5.0 knot for the kite type. 5. The opening efficiency of the kite type was approximately 50% and 25% larger than that of the proto type and the non-float type, respectively.

• Applied Chemistry for Engineering
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• 제21권6호
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• pp.648-652
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• 2010

Catalytic activities of the partial oxidation of methane (POM) to hydrogen were investigated over Pd(5)/Ti-SPK and Pd(5)/Zr-SPK in a fixed bed flow reactor (FBFR) under atmosphere, and the catalysts were characterized by BET, XPS, XRD. The BET surface areas, pore volume and pore width of Horvath-Kawaze, micro pore area and volume of t-plot of Pd(5)/Ti-SPK and Pd(5)/Zr-SPK were $284m^2/g$, $0.233cm^3/g$, 3.9 nm, $30m^2/g$, $0.015cm^3/g$ and $396m^2/g$, $0.324cm^3/g$, 3.7nm, $119m^2/g$, $0.055cm^3/g$, repectively. The nitrogen adsorption isotherms were type IV with hysteresis. XPS showed that Si 2p and O 1s core electronlevels of Ti-SPK and Zr-SPK substituted Ti and Zr shifted to slightly lower binding energies than SPK. The oxidation states of Pd on the surface of catalysts were $Pd^0$ and $Pd^{+2}$. XRD patterns showed that crystal structures of fresh catalyst changed amorphous into crystal phase after reaction. The conversion and selectivity of POM to hydrogen over Pd(5)/Ti-SPK and Pd(5)/Zr-SPK were 77, 84% and 78, 72%, respectively, at 973 K, $CH_4/O_2$ = 2, GHSV = $8.4{\times}10^4mL/g_{cat}{\cdot}h$ and were kept constant even after 3 days in stream. These results confirm superior activity, thermal stability, and physicochemical properties of catalyst in POM to hydrogen.

• Journal of the Korean GEO-environmental Society
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• 제15권12호
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• pp.117-128
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• 2014

Generally, when constructing a tunnel close to existing structures, the tunnel must be built at a constant distance from the structures that is more than width of tunnel to minimize the impact of interference between an existing structures and new tunnel. Spacing of these closed tunnels should be designed considering soil state, size of tunnel and reinforcement method. Particularly when the ground is soft, a care should be taken with the tunnel plans because the closer the tunnel is to the existing structures, the greater the deformation becomes. As methods of reviewing the effect of cavities on the stability of a tunnel, field measurement, numerical analysis and scaled model test can be considered. In the methods, the scaled model test can reproduce the engineering characteristics of a rock in a field condition and the shape of structures using the scale factor even not all conditions cannot be considered. In this study, when construction of a tunnel close to existing structures, the method and considering factors of the scaled model test were studied to predict the actual tunnel behavior in planning stage. Furthermore, model test results were compared with the numerical analysis results for verifying the proposed model test procedure. Also, practical results were derived to verify the stability of a tunnel vis-a-vis cavities through the scaled model test, which assumed spacing distances of 0.25 D, 0.50 D, and 1.00 D between the cavities and tunnel as well as the network state distribution. The spacing distances of 1.0 D is evaluated as the critical distance by the results of model test and numerical analysis.

• Korean Journal of Environmental Agriculture
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• 제20권4호
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• pp.203-210
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• 2001

In order to environmentally use wood chips manufactured from low valued forest resources by forest tendering, wood chips were used for the evaluation on chips characteristics, decomposition capability of organic wastes, and field experiment and determination of conditions for decomposer. Bioclusters manufactured by Cryptomeria japonica, commercially available wood chips in Japan, showed higher pore ratio, water reservation and water resistance, and higher cellulose content with lower hot water solubles than domestic wood chips. The useful size of wood chips for swine manure decomposition was 10 (length) ${\times}$ 5 (width) ${\times}$ 2 (thickness) mm, and cellulose contents and alkali solubles of Pinus densiflora and Populus tomentiglandulosa were similar to those of bioclusters. According to the decomposition ratio depending on wood species, it was ordered as Pinus densiflora > Pinus koraiensis > Cryptomeria japonica. The swine manure decomposition ratio depending on treatment hours by Pinus koraiensis was constant with the ratio of 15 to 16 g per hour by 1 kg of chip, indicating of daily swine decomposition amount of 390 kg by 1 ton of chips which was equal to the amount of daily swine manure production by 70 swines. Analyzing by long term used wood chips during 40 days treatment, the treated wood chips characteristically showed stable total nitrogen content, suitable pH, high accumulation of inorganic contents such as calcium, phosphorus, potassium and sodium, and no odor. During winter, the inner temperature of decomposer was kept at $43^{\circ}C$, but air bubble was occurred due to high pH and viscosity of swine manure. The most appropriate mixing ratio between wood chips and swine manure was 1 versus 2 or 3, and at more than ratio 1 versus 3, ammonia gas was caused because of anaerobic fermentation status by high moisture content of wood chips. The mixing interval of decomposer was 3 mins. per hour for the best swine decomposition.

• The Korean Journal of Nuclear Medicine Technology
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• 제16권1호
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• pp.12-16
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• 2012

Purpose : In conventional PET image reconstruction, iterative reconstruction methods such as OSEM (Ordered Subsets Expectation Maximization) have now generally replaced traditional analytic methods such as filtered back-projection. This includes improvements in components of the system model geometry, fully 3D scatter and low noise randoms estimates. SharpIR algorithm is to improve PET image contrast to noise by incorporating information about the PET detector response into the 3D iterative reconstruction algorithm. The aim of this study is evaluation of SharpIR reconstruction method in PET/CT. Materials and Methods: For the measurement of detector response for the spatial resolution, a capillary tube was filled with FDG and scanned at varying distances from the iso-center (5, 10, 15, 20 cm). To measure image quality for contrast recovery, the NEMA IEC body phantom (Data Spectrum Corporation, Hillsborough, NC) with diameters of 1, 13, 17 and 22 for simulating hot and 28 and 37 mm for simulating cold lesions. A solution of 5.4 kBq/mL of $^{18}F$-FDG in water was used as a radioactive background obtaining a lesion of background ratio of 4.0. Images were reconstructed with VUE point HD and VUE point HD using SharpIR reconstruction algorithm. For the clinical evaluation, a whole body FDG scan acquired and to demonstrate contrast recovery, ROIs were drawn on a metabolic hot spot and also on a uniform region of the liver. Images were reconstructed with function of varying iteration number (1~10). Results: The result of increases axial distance from iso-center, full width at half maximum (FWHM) is also increasing in VUE point HD reconstruction image. Even showed an increasing distances constant FWHM. VUE point HD with SharpIR than VUE point HD showed improves contrast recovery in phantom and clinical study. Conclusion: By incorporating more information about the detector system response, the SharpIR algorithm improves the accuracy of underlying model used in VUE point HD. SharpIR algorithm improve spatial resolution for a line source in air, and improves contrast recovery at equivalent noise levels in phantoms and clinical studies. Therefore, SharpIR algorithm can be applied as through a longitudinal study will be useful in clinical.

• Archives of Reconstructive Microsurgery
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• 제5권1호
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• pp.24-34
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• 1996

There are many kinds of free flaps for management of extensive soft tissue defect of extremities in orthopaedic field. Free vascularized scapular flap is one of the most useful and relatively easy to application. This flap has been utilize clinically from early eighties by many microsurgical pioneers. Authors performed 102 cases of this flap from 1984 to 1995. We have to consider about the surgical anatomy of the flap, technique of the donor harvesting procedures, vascular varieties and anatomical abnormalities and success rate and the weak points of the procedure. This flap nourished by cutaneous branches from circumflex scapular vessels emerges from the lateral aspect of the subscapular artery 2.5-5cm from its lateral origin passing through the triangular space(bounded by subscapularis, teres minor, teres major, long head of triceps). The terminal cutaneous branch runs posteriorly around the lateral border of the scapular and divided into two major branches, those transeverse horizontally and obliquely to the fascial plane of overlying skin of the scapular body. We can utilize these arteries for scapular and parascapular flap. The vascular pedicle ranged from 5 to 10 cm long depends on the dissection, usually two venae comitantes accompanied circumflex scapular artery and its major branches. The diameter of the circumflex scapular artery is more than 1mm in adult, rare vascular variation. Surgical techniques : The scapular flap can be dissected conveniently with prone or lateral decubitus position, prone position is more easier in my experience. There are two kinds of surgical approaches, most of the surgeon prefer elevation of the flap from its outer border towards its base which known easier and quicker, but I prefer elevation of the flap from its outer border because of the lowering the possibilities of damage to vasculature in the flap itself which runs just underneath the subcutaneous tissue of the flap and provide more quicker elevation of the flap with blunt finger dissection after secure pedicle dissection and confirmed the course from the base of the pedicle. There are minimal donor site morbidity with direct skin closure if the flap size is not so larger than 10cm width. This flap has versatility in the design of the flap shape and size, if we need more longer and larger one, we can use parascapular flap or both. Even more, the flap can be used with latissimus dorsi musculocutaneous flap and serratus anterior flap which have common vascular pedicle from subscapular artery, some instance can combined with osteocutaneous flap if we include the lateral border of the scapular bone or parts of the ribs with serratus anterior. The most important shortcoming of the scapular free flap is non sensating, there are no reasonable sensory nerves to the flap to anastomose with recipient site nerve. Results : Among our 102 cases, overall success rate was 89%, most of the causes of the failure was recipient site vascular problems such as damaged recipient arterial conditions, and there were two cases of vascular anomalies in our series. Patients ages from 3 years old to 62 years old. Six cases of combined flap with latissimus dorsi, 4 cases of osteocutaneous flap for bone reconstruction, 62 parascapular flap was performed - we prefer parascapular flap to scapular. Statistical analysis of the size of the flap has less meaningful because of the flap has great versatility in size. In the length of the pedicle depends on the recipient site condition, we can adjust the pedicle length. The longest vascular pedicle was 14 cm in length from the axillary artery to the enter point cutaneous tissue. In conclusion, scapular free flap is one of the most useful modalities to manage the large intractable soft tissue defect. It has almost constant vascular pedicle with rare anatomical variation, easy to dissect great versatility in size and shape, low donor morbidity, thin and hairless skin.