Search

Purpose: This study assessed recent trends in the incidence of urologic cancer and patient survival in Korea.Materials and Methods: The incidence of urologic cancer in Korea was calculated based on the Korea National Cancer Incidence Database and the South Korean Statistical Information Service Database. Data from 2000 to 2020 were used to determine the incidence, death, prevalence, and survival rates of urologic cancer.Results: Urologic cancer was diagnosed in 27,514 cases, accounting for 11.1% of the total cancer incidence. In 2020, there were 16,815 prostate cancer cases, 5,946 kidney cancer cases, and 4,753 bladder cancer cases. The age-standardized rate (ASR) for the incidence of prostate, kidney, and bladder cancer increased from 2000 to 2020. The overall ASR was 56 per 100,000 in 2020. In 2000, the ASRs for prostate, kidney, and bladder cancer were 2.9, 3.1, and 4.8 per 100,000, respectively, whereas they were 32.7, 11.6, and 9.3 per 100,000, respectively, in 2020. Urologic cancer has also seen a steady increase in the death rate, prevalence rate, and relative survival rate over the past 20 years. The 5-year relative survival rates for patients diagnosed with prostate cancer, kidney cancer, and bladder cancer during the 5-year period from 2015 to 2019 were 94.4%, 84.7%, and 76.5%, respectively. Among urologic cancers, prostate cancer had the highest survival rate, and bladder cancer had the lowest.Conclusions: The survival rate for urologic cancer is increasing; however, the incidence and prevalence rates continue to rise.

This article proposes a current-scaling gain-compen-sation algorithm for motor drive applications under the locked-rotor condition. In heavy industrial applications, such as elevators and cranes, initial commissioning tests are performed with the rotor locked. To compensate for errors in the current-scaling gain, the proposed method controls the current in the d–q axis using two-phase current-sensing methods in a stationary reference frame. The three-phase scaling gains are then estimated using the resulting d -axis current command and output voltage and are compensated for using these estimations. The proposed method delivers accurate compensations by considering the inequality between phase resistances. The effectiveness of the proposed algorithm is verified through simulations and experiments.

Pelubiprofen (PEL), which is a commercialized non-steroidal anti-inflammatory drug (NSAID), is associated with the risk of gastrointestinal (GI) adverse events following long-term exposure and has poor water-soluble properties. Here, a new pelubiprofen tromethamine (PEL-T) with improved solubility, permeability, GI safety, and absorption, compared to PEL, has been developed. The nuclear magnetic resonance spectroscopy (NMR), differential scanning calorimetry (DSC), and Fourier transform infrared spectroscopy (FT-IR) results confirmed that the PEL-T was well formed. The powder of PEL-T showed the presence of additional 6H protons at δ 3.66–3.61 in the 1H NMR spectrum, and shifted the sharp endothermic peaks at 129 °C in DSC, and the spectrum of distinct absorption peaks in FT-IR. In addition, compared with PEL, PEL-T showed a significantly improved solubility in various media and an increased permeability coefficient (Kp) in Caco-2 cells. Furthermore, compared to PEL oral administration, PEL-T was found to significantly reduce the damaged area in an acute gastric damage rat model. The pharmacokinetic study of the PEL-T powder showed higher maximum plasma concentration (Cmax) and area under the plasma concentration–time curve from 0 h to the last time point (AUCt) than those of the PEL powder. Taken together, our data suggest that PEL-T is a recommendable candidate with enhanced gastrointestinal safety and better absorption compared with commercial PEL.

This study numerically verified the enhanced efficiency of a steel reheating furnace when applying oxy-fuel combustion instead of air-fuel combustion. Only radiation heat transfer was considered to analyze the periodically transient slab heating for an axial-fired furnace. The radiation field was computed without flow field calculation by dividing the entire furnace into ten subzones of which the temperatures were calculated by taking the overall heat balance for all the subzones. A total of five cases, 2 for air-fuels and 3 for oxy-fuels, was analyzed to compare the slab heating behavior between air-fuel and oxy-fuel combustion. The modified 5-gas WSGGM was used for oxy-fuel combustion cases to fulfill the characteristics of CO2 and H2O enriched medium, while ordinary 4-gas WSGGM was used for air-fuel combustion cases. From the efficiency analysis for the total of five cases, it was predicted that oxy-fuel combustion gave an approximately 50% enhancement in efficiency compared to air-fuel combustion.

Mitochondrial calcium overload is a crucial event in determining the fate of neuronal cell survival and death, implicated in pathogenesis of neurodegenerative diseases. One of the driving forces of calcium influx into mitochondria is mitochondria membrane potential (ΔΨm). Therefore, pharmacological manipulation of ΔΨm can be a promising strategy to prevent neuronal cell death against brain insults. Based on these issues, we investigated here whether nobiletin, a Citrus polymethoxylated flavone, prevents neurotoxic neuronal calcium overload and cell death via regulating basal ΔΨm against neuronal insult in primary cortical neurons and pure brain mitochondria isolated from rat cortices. Results demonstrated that nobiletin treatment significantly increased cell viability against glutamate toxicity (100 µM, 20 min) in primary cortical neurons. Real-time imaging-based fluorometry data reveal that nobiletin evokes partial mitochondrial depolarization in these neurons. Nobiletin markedly attenuated mitochondrial calcium overload and reactive oxygen species (ROS) generation in glutamate (100 µM)-stimulated cortical neurons and isolated pure mitochondria exposed to high concentration of Ca2+ (5 µM). Nobiletin-induced partial mitochondrial depolarization in intact neurons was confirmed in isolated brain mitochondria using a fluorescence microplate reader. Nobiletin effects on basal ΔΨm were completely abolished in K+-free medium on pure isolated mitochondria. Taken together, results demonstrate that K+ influx into mitochondria is critically involved in partial mitochondrial depolarization-related neuroprotective effect of nobiletin. Nobiletin-induced mitochondrial K+ influx is probably mediated, at least in part, by activation of mitochondrial K+ channels. However, further detailed studies should be conducted to determine exact molecular targets of nobiletin in mitochondria.

NOx reduction characteristics of syngas fuel were numerically investigated for the 2 MW pilot-scale heavy oil furnace of KITECH (Korea Institute of Industrial Technology). The secondary fuel, syngas, was fed into the furnace with two purposes: partial replacement of main fuel and reburning of NOx. Some portion of syngas was fed into the flame zone to replace partially the heavy oil, while the other portion was fed into the furnace downstream to reduce NOx generation. The numerical prediction was verified by comparing it to the experimental results. The syngas of KITECH’s experiment, which assumedly had been produced from biomass, had a very low calorific value and contained 3% hydrocarbon. This study investigated the precise behavior of NOx generation and NOx reduction as well as the thermo-fluidic characteristics inside the furnace, which were unavailable from the experiment. In addition to 3% hydrocarbon syngas, 5% and 7% hydrocarbon syngas were numerically tested as reburning fuels to analyze the effect of hydrocarbon proportion to NOx reduction. The prediction shows that the 3% hydrocarbon syngas is equally effective as 7% hydrocarbon syngas in reducing NOx.

A method for the identification of mechanical parameters based on integral calculation is presented. Both the moment of inertia and the friction constant are identified by the method developed here, which is based on well-known mechanical differential equations. The mechanical system under test is excited according to a pre-determined low-frequency sinusoidal motion, minimizing the distortion, and increasing the accuracy of the results. The parameters are identified using integral calculation, increasing the robustness of the results against measurement noise. Experimental data are supported by simulation, confirming the effectiveness of the proposed technique. The performance improvements shown here are of use in the design of speed and position controllers and observers. Owing to its simplicity, this method can be readily applied to commercial inverter products.

This paper proposes a design guideline for the feedback gain of the adaptive full-order observer in the speed sensorless control of induction machines. The performance of the adaptive full-order observer is dependent on its feedback gain. This paper presents a pole placement method for the observer feedback gain design to improve the estimation performance of the speed adaptive observer. In the proposed method, the observer poles can be chosen independently of the induction motor poles. Instead, they can be positioned according to the operating speed. An analysis and experimental results obtained with the proposed method reveals better performances under general operating conditions.

The aim of this study was to investigate the relationship between the chemical composition and antioxidant activity of roasted jinpi extract (RJE) under various roasting conditions (e.g., 100–155 °C). The total phenolic contents, flavonoid content, and antioxidant activities in RJE increased with increased roasting temperature, and the highest efficacy was observed at 155 °C. The narirutin and hesperidin contents in RJE reached 15.32 and 11.50 mg/g, respectively, under this optimal temperature (155 °C). The roasting process caused the Maillard reaction to occur which increased the amounts of 2,4-diamino-5-(3′,4′-dichlorophenyl)-6-methyl pyrimidine (DDMP) and 5-hydroxymethlyfurfural (5-HMF) but decreased the total sugar content in RJE. Among the compounds contained in RJE, DDMP had the strongest diethylene glycol, 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity, which was determined by DPPH-HPLC analysis. These results suggest that roasting jinpi under optimal conditions increases the amount of phenolics and flavonoids and thereby enhances the antioxidant activity of jinpi.

Citrus canker caused by Xanthomonas citri subsp. citri (Xcc) has been quarantined by many countries in the world. Recently, the usage of methyl bromide should be limited, application by gamma irradiation on the agricultural production is raised as an alternative method. In this study, the level of gamma irradiation which could decrease of population of Xcc in the suspension or on the surface of citrus fruit was investigated. The D10 value of Xcc, which is radiation dose required to reduce the number of the microorganism, was 55 and 28 Gy in the suspension and on the surface of citrus fruit, respectively. Furthermore, disease severity was suppressed on the citrus leaves inoculated with Xcc suspension pre-treated with gamma irradiation. Based on this study, it is suggested that Xcc on the citrus fruit could be eradicated by gamma irradiation and the results of this study may be valuable for application of gamma ray in quarantine activity

The autoignition characteristics of a binary component fuel droplet inside a rapid compression machine (RCM) were investigated. An RCM is an experimental setup for simulating a single compression stroke of an internal combustion engine. During the experimental time, the temperature and pressure inside the reaction chamber were temporally varied, and the ignition of a binary component droplet occurred when sufficient fuel vapor was generated around the droplet. n-Heptane was selected as the base fuel, and a specific volumetric ratio of iso-octane and n-decane was added as fuel additives. The droplet was placed at the center of the reaction chamber by suspending at the tip of a thermocouple, and its transient temperature was measured. The initial droplet diameter was in the range of 450−1000 μm, and the temporal variation of droplet diameter was measured by analyzing images from a high-speed charge-coupled device array camera. In the single component experiments, a monotonic increase of the ignition delay w...

The dispersion characteristics of hydrogen leaking through a small hole from a high-pressure source were investigated experimentally to develop guidelines for determining safety distances for hydrogen stations. Tests were carried out for leaking holes with diameters of 0.5, 0.7 and 1.0 mm and for release pressures of 100, 200, 300 and 400 bar. For these realistic hydrogen leaking conditions, the Froude numbers are so large that the buoyancy effect, manifested by the hydrogen jets bending upward, can be expected to be negligible. Flow visualization was performed using an Nd-YAG laser to confirm that the buoyancy effect was negligible. By letting a thin laser sheet penetrate the center line of a hydrogen jet conveying Al2O3 particles, the particles were illuminated and the hydrogen jet was visualized. The hydrogen concentration was measured by sampling hydrogen at five points along the jet centerline, based on the large Froude number. The measured data were always lower than the isentropic prediction.

This study was conducted to investigated effects of water relation of mulching and trickle irrigation on the external and internal fruit quality in Satsuma mandarin grafted on trifoliate orange rootstock in a orchard assigned to randomly three groups; whole period of Tyvex mulching (TM), Tyvex mulching with trickle irrigation once a week from October 22 to harvesting season (WM) and non-mulching treatment (NM). The average soil moisture content in the TM was lower than the WM during the time of trickle irrigation from Oct. 21 to Nov. 28. The leaf water potential was at the level of Ψmax of -1.5 to -2.5 MPa during whole period of Tyvex mulching treatment but gradually increased at the point of supplement of water. The water and osmotic potential in juice vesicle was decreased by drought but increased again in response to the supply of water in WM. The total soluble solids (TSS) in fruit juice was increased by drought stress, but diminished in response to supply of water after drought. The content of titratible acidity was increased by drought stress but gradually decreased due to supplement of water after drought, reached it at the level of 1%. It was suggested that the accumulation of the total soluble solids compensates the degree of active osmoregulation and the decrease in content of acidity accounts for the fast respiration and water uptake resulted of the water after drought.

When a large amount of CO2 is released from a tank due to material or mechanical defects in a CO2 carrier, both humans and the carrier itself may be in serious danger. The released CO2 can damage the carrier because CO2 is released at a low temperature. In addition, the released CO2 can be hazardous to humans because it may cause an oxygen deficiency over a large area. Thus, if a detection system senses a CO2 leak from a storage tank, jettisoning and ventilation systems are both activated. The jettisoning system completes the evacuation of liquid CO2 from the defective tank, and the ventilation system vents the CO2 gas that has accumulated inside the ship to the outside. The impact of the released CO2 on humans depends on the stack location and the features of the jettisoning system and the ventilation system. To reduce the hazards associated with CO2 leaks, the location of the stack should be carefully chosen on the basis of multiple factors, such as the ship speed, the jettisoning rate, and the leakage rate. This study numerically investigates the dispersion of CO2 released by jettisoning and ventilation with respect to stack location, mass flow rate, and ship speed.

a b s t r a c t This experimental study was performed to investigate the flow characteristics in the jettisoning flow line of a liquid CO2 carrier. When a pressurized liquid CO2 container loses mechanical integrity, possibly by material or mechanical defects, the liquid inventory should be drained out rapidly for safety reasons using the so-called jettisoning process. In the course of jettisoning, the liquid CO2 undergoes two phase change stages, from liquid to liquid + vapor and from liquid + vapor to solid + vapor. Consequently, the jettisoning release rate is affected by the characteristics of these phase changes. In this study, liquid CO2 was discharged through a small tube, representing a jettisoning flow line. The temperature and pressure were measured along the tube, and the locations of the phase changes were inferred from the measured data. The experimental results showed that active nucleation occurred near the tube tip and that the phase change into solid and vapor occurred just after leaving the pipe, irrespective of the tube length in this study. © 2013 The Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.

Speed germination success and robust vegetative growth of citrus rootstock through improved sowing methods and fertilizer inputs offer the usage of root system for the citrus. The current study evaluated the influence of seed coat removal and different fertilizer concentrations on plant germination and plant growth of spontaneous rootstock siblings. Decoated and coated seeds of diploid and tetraploid plants were sown in tubes. Commercial fertilizer concentrations of 0, 2, 4, 6, 8 and were added. The experimental layout followed a randomized block factorial design (seed coat removal fertilizer concentration) for each rootstock. Fertilizer concentrations were 0, 10, 20 and of the fertilizer for the resistance of the strength on the salt level. The germination rate of seeds without testa sown in vitro was improved (67-80%) compared to that of nontreated seeds. The eventual tree height of the seeds without testa in the diploid group was increased due to higher fertilization compared to that in the nontreated group. The removal of seed testa promoted the seed germination of both diploid and tetraploid trifoliate orange and resulted in greater height. Their vegetative development was also increased due to the increased fertilization of the rootstock. The Fv/Fm value for the diploid plants was 0.4 and 0.8 for the tetraploid ones under salt stress after 11 days of treatment. The removal of seed testa may improve the seed germination of trifoliate orange. Tetraploid trifoliate orange appears to possess resistance to salt stress compared to the diploid variety.

In higher plants, glutamate decarboxylase (GAD, EC 4.1.1.15) is known as a key enzyme in the synthesis of γ-aminobutyric acid (GABA), which is not only a valuable food component for animals, but is also a signaling molecule in plants. Although the completion of the soybean genome sequencing has made it possible for the identification of GAD gene families, the systematic analysis of GAD genes in soybean has not yet been reported. Based on the recently released soybean whole-genome sequences, in this study, we identified five GAD genes that contain conserved residues and calmodulin (CaM)-binding domain in the C-terminal region. This indicates that the putative soybean GADs (GmGADs) are Ca2+/CaM-binding proteins. An abundance of GmGAD4 and 5 transcripts have been observed in cotyledons, whereas GmGAD1 and 3 were expressed in hypocotyls and roots of 7-day-old soybean sprouts. In addition, we have determined a positive correlation between the expression of GmGAD genes and GABA accumulation during the germination process. Furthermore, the induction of GmGAD1, 4, and 5 transcripts following infection of hypocotyls with Phytophthora sojae suggests that GABA may play a role in the resistance mechanism. Taken together, our comparative genomic analysis of GAD genes and encoded proteins in soybean is the first step toward the functional dissection of this family, and we present information that will assist future studies on GABA metabolism and signaling research.

A hydrogen supplying system for hydrogen fuel cell cars is anticipated to utilize highly pressurized hydrogen gas at pressures up to 700 bar. In this highly pressurized environment, large amount of hydrogen can be leaked from a relatively small hole caused by material and mechanical defects. A leaked hydrogen jet can reach very far in distance and the size of the leak plays an important role in determining the safety of hydrogen recharge facilities. This study numerically investigated the concentration distribution and the mass flux of hydrogen leaked from a highly pressurized source through a hole whose size is less than 1.0 mm. Numerical analysis was performed in axisymmetric coordinates on the assumption that the hydrogen jet has a huge Froude number and that buoyancy forces can be negligible. The predicted hydrogen concentration along the centerline of a hydrogen jet was compared with experimental data for verification of the numerical analysis and it satisfied the hyperbolic decay characteristics and matched the experiment well. The mass fluxes for the various hole lengths of this study were found to be 5%–20% less than those predicted using an isentropic flow assumption.

Citrus ‘Hallabong’ powders were prepared using hot air and freeze drying methods, and their physicochemical and flow properties were measured. The yields of the powders from whole fruit and pressed cake by hot air drying method were 17.5 and 22.0%, while those by freeze drying method were 20.0 and 22.5%, respectively. Vitamin C was high in freeze-dried whole fruit powders (220.8–364.7 mg/100 g) compared with those in hot air-dried ones (80.1–114.6 mg/100 g). Browning index of freeze-dried powders was significantly lower than those of hot air-dried ones. Bulk densities, compaction densities, and Hausner ratios of the powders were significantly higher in freeze drying method compared with hot air drying method. Water solubilities and hygroscopicities of freeze-dried powders were higher than those of hot air-dried ones. In conclusion, ‘Hallabong’ powders can be made using freeze drying method with high quality in terms of vitamin C content, color, and water solubility.

We report on the effect of an AlGaN interlayer with a low Al composition, which is inserted between multiple quantum wells (MQWs) and an AlGaN electron blocking layer (EBL) in light-emitting diodes (LEDs). The band diagram shows that this interlayer reduces the hole barrier height between the last GaN barrier in MQWs and the AlGaN EBL to enhance the hole injection. The optical output power at 20 mA of LEDs with interlayer is increased by 20% more than that of LEDs without an interlayer. This improvement is attributed to the enhanced radiative recombination rate, which is due to a more uniform hole distribution and higher hole concentration in MQWs.

In this study, we compare the quality of the mango cv. Irwin cultivated in Jeju and Okinawa by evaluating the total soluble solids (TSS) and antioxidant activity (AA) from ethanol extracts of the fruit. TSS and AA were higher in fruit cultivated at the Research Institute of Climate Change and Agriculture in Jeju (RICA) and Okinawa farm, where the low tree height cultivation method is used, than in fruit cultivated on farm in Jeju. Also, the mangiferin content of the Okinawa farm was higher than those produced on the RICA and Jeju farm house. These results suggest that the lowering tree height cultivation method improves the quality of the mango cv. Irwin.

A transient radiative slab heating analysis was performed to investigate the effect of various fuel mixtures on the performance of an axial-fired reheating furnace. The various fuel mixtures tested were assumed to be attained by mixing COG (coke oven gas) and BFG (blast furnace gas), which are the two main byproduct gases found in the integrated steel mill industry. The numerical prediction of radiative heat transfer was calculated using an FVM radiation solving method, which is a well-known and efficient method for curvilinear coordinates. The WSGGM (weighted sum of gray gas model) was also adopted to calculate the radiative heat transfer in composition dependent media. The entire furnace was divided into fourteen sub-zones to calculate the radiative thermal characteristics of the furnace without flow field calculations. Each sub-zone was assumed to have homogeneous media and wall temperatures. All of the medium and wall temperatures were computed by calculating the overall heat balance using some relevant assumptions. The overall heat balance was satisfied when the net heat input equaled the three sources of heat loss in each sub-zone, wall loss, skid loss, and slab heating loss.

A 3D unsteady numerical simulation of a reheating furnace was performed to obtain the optimal slab residence time. Too long residence time decrease the efficiency of the reheating furnace, whereas too short residence time cannot satisfy the required heating quality of a slab. The total five cases of residence times – 6032 s, 6496 s, 6960 s, 7424 s and 7888 s – were investigated for the optimum residence time analysis with the two slab requirements, those of emission temperature and uniformity. In this study, the slab emission temperature should be in the range between 1373 K and 1573 K. The skid mark severity of an emitted slab should be lower than 50 K to satisfy the uniformity requirement. The numerical analysis was done for the identical geometry and operating condition of the reheating furnace using FLUENT. Slabs were assumed to move very quickly that it took no time for them to move next positions. The quick movements of slabs were processed with the own developed User-Defined Function program. Among the five cases of residence times, the residence time of 7427 s turned out to be most efficient.

This study revealed the behavior of droplets formed through leak process in deep water. There was a threshold depth named the universal attraction depth (UAD). Droplets rose upward in the zone below the UAD called the rising zone, and settled down in the zone above the UAD called the settling zone. Three mass loss modes were identified and formulated: dissolution induced by mass transfer, condensation by heat transfer and phase separation by pressure decrease. The first two were active for the settling zone, and all the three were effective for the rising zone. In consequence, the life time of the droplets in the rising zone was far shorter than that of the droplets in the settling zone.

The extracts of two native berries from the Jeju Island of Korea were used to assess polyphenolics and flavonol levels, superoxide dismutase (SOD)-like enzyme activity, free radical scavenging activity, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide cell viability, protective effects against H2O2-induced cow pulmonary artery endothelium (CPAE) cell cytotoxicity and inhibition of low density lipoprotein (LDL) peroxidation. The total content of the flavonols and phenolic compounds in the leaves was higher than the fruit for both berries. In the free radical scavenging and SOD-like enzyme assay, all extracts showed strong antioxidative effects. The CPAE viability was greatly reduced and the survival rate was near 37% when the cells were treated with 1.0 mM H2O2 for 24 h. The extracts also inhibited lipid peroxidation in human LDL, measured as reduction in malondialdehyde production. The results showed that the leaf extracts of Empetrum nigrum significantly protected human LDL from Cu2+-induced oxidation. E. nigrum is suggested as an excellent potential source of natural antioxidants. PRACTICAL APPLICATIONS The results of these two Korean native berry species, especially Shiromi species, showed very strong effects on the inhibition of low density lipoprotein (LDL) oxidation and free radical scavenging. The LDL and free radicals have known close relations with coronary artery and cerebrovascular atherosclerosis. The antioxidative effects of these berries were stronger than existing commercial products. From these results, Korean native berry species might be very useful for the development of functional food for antioxidants preventing oxidative stress-related diseases like atherosclerosis. Making a new commercial product with Korean Shiromi berry will have good prospects.

Numerical analysis of slab heating characteristics in a reheating furnace has been accomplished using FLUENT, a commercial software. The phenomena in the furnace are periodically transient because the slabs are transported toward a rolling mill with every time interval controlled. Unsteady calculation has been performed to obtain a periodically transient solution. A User-Defined Function (UDF) program has been developed to process the movement of slabs because FLUENT cannot handle the movement using its default functions. When the mean temperature of a slab emitted to the rolling mill does not change, calculation is considered to have converged and is stopped. This convergence criterion is appropriate for achieving an analytical solution. With the boundary and initial conditions given, over 55 new slabs are inserted to get a converged solution. Skid posts and beams are included in the calculation because they disturb radiation heat transfer from hot combustion gas to the slabs. This article examines what the slabs experience in the furnace before they are emitted to the rolling mill and whether a slab emitted to the rolling mill satisfies the required slab conditions, such as target temperature and skid severity.

Ge and Sn as n-type dopants in (001) β-Ga2O3 films were investigated using plasma-assisted molecular beam epitaxy. The Ge concentration showed a strong dependence on the growth temperature, whereas the Sn concentration remains independent of the growth temperature. The maximum growth temperature at which a wide range of Ge concentrations (from 1017 to 1020 cm−3) could be achieved was 675 °C while the same range of Sn concentration could be achieved at growth temperature of 750 °C. Atomic force microscopy results revealed that higher growth temperature shows better surface morphology. Therefore, our study reveals a tradeoff between higher Ge doping concentration and high quality surface morphology on (001) β-Ga2O3 films grown by plasma-assisted molecular beam epitaxy. The Ge doped films had an electron mobility of 26.3 cm2 V−1 s−1 at the electron concentration of 6.7 × 1017 cm−3 whereas the Sn doped films had an electron mobility of 25.3 cm2 V−1 s−1 at the electron concentration of 1.1 × 1018 cm−3.

In this study, the unknown wall temperature profile of a cylinder was predicted by applying the inverse method. The temperature profile of the cylinder wall was predicted from the given temperature data at measurement points near the cylinder wall. The cylinder was assumed to represent a typical pipe in a bundle of heat exchange tubes operating in a high temperature system. Radiative heat transfer was incorporated as one of major heat transfer modes to consider a hot gas flow passing over the cylinder. The corresponding inverse problem was solved by minimizing an objective function by applying the iterative conjugate gradient method. A multi-block grid composed of three different blocks was used for better computational accuracy and convenience in locating the measurement points. A new method, which could be applicable to non-symmetric geometry, was adopted to solve the adjoint equation. In this study, the effects of number and location of the measurement points were numerically investigated. When the measurement points were too close to the cylinder, the predicted temperature profile exhibited larger fluctuations. The results have also shown that an appropriate number of measurement points were required to improve the prediction of the boundary temperature profile.

Transient radiative heating characteristics of slabs in a walking beam type reheating furnace is predicted by the finite-volume method (FVM) for radiation. The FVM can calculate the radiative intensity absorbed and emitted by hot gas as well as emitted by the wall with curvilinear geometry. The non-gray weighted sum of gray gas model (WSGGM) which is more realistic than the gray gas model is used for better accurate prediction of gas radiation. The block-off procedure is applied to the treatment of the slabs inside which intensity has no meaning. Entire domain is divided into eight sub-zones to specify temperature distribution, and each sub-zone has different temperatures and the same species composition. Temperature field of a slab is acquired by solving the transient 3D heat conduction equation. Incident radiation flux into a slab is used for the boundary condition of the heat conduction equation governing the slab temperature. The movement of the slabs is taken into account and calculation is performed during the residence time of a slab in the furnace. The slab heating characteristics is also investigated for the various slab residence times. Main interest of this study is the transient variation of the average temperature and temperature non-uniformity of the slabs.

A numerical program has been developed and applied to investigate the heating characteristics of the slab in a bench scale reheating furnace. Its numerical results were validated by comparison with the experimental data obtained in the test facility in POSCO company

Aeroponics, used mainly for the production of virus-free seed potato (Solanum tuberosum L.) in South Korea, poses several problems, particularly, the risk of blackout and lenticle hypertrophy. Recently, a capillary culture system that supplies nutrient solution through wicks was developed to overcome these problems. In a capillary culture system, the nutrients that the plant cannot take up remain in the solid media in which they accumulate, while the plant roots adhere to the wicks. In this study, a complete nutrient solution, a NPK fertilizer, and different levels of the controlled release fertilizers of Multicote, Osmocote, and Magamp K, were tested with water supplied through wicks. The final fresh weight per plant, in the nutrient solution plot weighed 72.9 g while that from the Multicote (100 g/box) plot weighed 66.4 g. The total tuber yield per square meter, in the Multicote (100 g/box) plot and Osmocote (80 g/box) plot were 13 and 4% higher, respectively, than that of the nutrient solution plot. The degree of the root penetration into the styrofoam bed of the controlled release fertilizer plot was only 13% of the nutrient solution plot.

The concentration of a constituent in a fruit, which is often related to fruit quality, is caused by changes in the accumulation of a constituent, water, or both. In this study, changes in dry matter percentage and sugar concentration of 'Hayward' kiwifruits were analyzed with respect to the accumulation of dry matter, sugars, or water during growth in 1995 and 1996. Fruit growth curve by fresh weight and water content showed a clear double sigmoid curve, whereas that based on dry matter did not. Percentage of dry matter, which increased until the end of stage II, decreased immediately after the start of stage III, and then recovered gradually. The decrease in dry matter was accompanied by a rapid inflow of water into the fruit, which indicates that the increase in water import into fruits is responsible for the re-starting of rapid growth at the beginning of stage III. During the latter half of stage III, dry matter content increased without an increase in water content. Starch concentration increased during stages I and II to reach a plateau at the beginning of stage III. Toward the end of stage III, starch concentration decreased, and total sugar concentration increased rapidly. Since no change in water content occurred during this period, the increase in total sugar content reflected directly to the concentration.