• Restorative Dentistry and Endodontics
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• v.32 no.1
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• pp.37-46
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• 2007

The C-shaped canal system is an anatomical variation mostly seen in mandibular second molars, although it can also occur in maxillary and other mandibular molars. The main anatomical feature of C-shaped canals is the presence of fins or web connecting the individual root canals. The complexity of C-shaped canals prevents these canals from being cleaned, shaped, and obturated effectively during root canal therapy, and sometimes it leads to an iatrogenic perforation from the extravagant preparation. The purpose of this study was to provide further knowledge of the anatomical configuration and the minimal thickness of dentinal wall according to the level of the root. Thirty extracted mandibular second molars with fused roots and longitudinal grooves on lingual or buccal surface of the root were collected from a native Korean population. The photo images and radiographs from buccal, lingual, apical direction were taken. After access cavity was prepared, teeth were placed in 5.25% sodium hypochlorite solution for 2 hours to dissolve the organic tissue of the root surface and from the root canal system. After bench dried and all the teeth were embedded in a self-curing resin. Each block was sectioned using a microtome (Accutom-50, Struers, Denmark) at interval of 1 mm. The sectioned surface photograph was taken using a digital camera (Coolpix 995, Nikon, Japan) connected to the microscope. 197 images were evaluated for canal configurations and the minimal thickness of dentinal wall between canal and external wall using 'Root Thickness Gauge Program' designed with Visual Basic. The results were as follows : 1. At the orifice level of all teeth, the most frequent observed configuration was Melton's Type C I (73%), however the patterns were changed to type C II and C III when the sections were observed at the apical third. On the other hand, the type C III was observed at the orifice level of only 2 teeth but this type could be seen at apical region of the rest of the teeth. 2. The C-shaped canal showed continuous and semi-colon shape at the orifice level, but at the apical portion of the canal there was high possibility of having 2 or 3 canals 3. Lingual wall was thinner than buccal wall at coronal, middle, apical thirds of root but there was no statistical differences.

• Cross-Cultural Studies
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• v.52
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• pp.53-78
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• 2018

In the moral culture of the West, love and justice are two commands with roots in ancient times. One is the heritage of Hebraism, and the other belongs to the tradition of Hebraism and Hellenism. The two concepts are the most important virtues required for preserving stability in society. These two commands are compatible, in an exclusive relationship to each other. To ultimately seek their reconciliation, the precise concept analysis and understanding of each of them should be premised on, due to the multi-layered meaning of implications of the two concepts. To this end, we first have started with a lexical meaning and have done a conceptual analysis of what these two concepts are expressing. We have looked at Paul $Ric{\oe}ur$ in his interpretation of the discourse of love and justice. Finally, we looked at how these two concepts are narrated in literature. Through the literary works of Stendal, Albert Camus, and Dostoevsky, we have seen examples of literary configurations that have been embodied in life. In this way, through conceptual analysis, discourse analysis, and narrative analysis of the two concepts, the following conclusions were drawn. Love and justice were not a matter of choice. We could see coldness and unrealism of a society lacking love or with a problem of unclean love, through Stendhal's and Albert Camus' novels and their actual debate. In addition, in unclean paternalism, risk of the power of love blocking certain a certain touch of justice was also confirmed. So, it was necessary for a healthy future society to explore the possibility of the coexistence of love and justice. We confirmed the possibility of compatibility in a 'considerate balance' wherein the 'moral judgment in situation' is required, as Paul $Ric{\oe}ur$ expressed. This ideal situation may be realized when forms of love involving solidarity, mutual care, and compassion with pain like Dostoevsky are combined with the principle of distributional justice. When Albert Camus pursued justice and eventually faced reality and mentioned the need for mercy, he could have made a moral judgment based on this situation. In the end, love protects justice, and justice contributes to the realization of love. Justice reduces super-ethical love to moral categories, and love plays a role in enabling justice to exert its full force.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2019.04a
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• pp.21-22
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• 2019

Melanin is a mixture of pigmented biopolymers synthesized by epidermal melanocytes that determine the skin, eye, and hair colors. Melanocytes produce two different kinds of melanin, eumelanin (dark brown/black insoluble pigments found in dark skin and dark hair and pheomelanin (lighter red/yellow). The biological role of melanin is to prevent skin damage by ultraviolet (UV) radiation. However, the overproduction or deficiency of melanin synthesis could lead to serious dermatological problems, which include melasma, melanoderma, lentigo, and vitiligo. Therefore, regulating melanin production is important to prevent the pigmentation disorders. Myanmar has a rich in natural resources. However, the chemical constituents of these natural resources in Myanmar have not been fully investigated. In the effort to search for compounds with anti-melanin deposition activity from Myanmar natural resources, five plants were collected in Myanmar. Extracts of these collected five plants were tested for anti-melanin deposition activity against a mouse melanoma cell line (B16-F10) induced with ${\alpha}$-melanocyte-stimulating hormone (${\alpha}$-MSH) and 3-isobutyl-1-methylxanthine (IBMX), and their anti-melanin deposition activities were compared with the positive control, arbutin. Among the tested extracts, the CHCl3 extracts of the Premna serratifolia (syn: P. integrifolia) wood showed anti-melanin deposition activities with IC50 values of $81.3{\mu}g/mL$. Hence, this study aims to identify secondary metabolites with anti-melanin deposition activity from P. serratifolia wood of Myanmar. P. serratifolia belongs to the Verbenaceae family and is widely distributed in near western sea coast from South Asia to South East Asia, which include India, Malaysia, Vietnam, Cambodia, and Sri Lanka. People in Tanintharyi region located in the southern part of Myanmar utilize the P. serratifolia, Sperethusa crenulata, Naringi crenulata, and Limonia acidissima as Thanaka, traditional cosmetics in Myanmar. Thanaka is applied in the form of paste onto skins to make it smooth and clear, as well as to prevent wrinkles, skin aging, excessive facial oil, pimples, blackheads, and whiteheads. However, the chemical constituents responsible for their cosmetic properties are yet to be identified. Moreover, the chemical constituents of P. serratifolia was almost uncharacterized. Investigation of the P. serratifolia chemical constituents is thus an attractive endeavor to discover new anti-melanin deposition active compounds. The investigation of the chemical constituents of the active CHCl3 extract of P. serratifolia led to isolation of four new lignoids, premnan A (1), premnan B (2), taungtangyiol C (3), and 7,9-dihydroxydolichanthin B (4), together with premnan C (5) (assumed to be an artifact), one natural newlignoid,(3R,4S)-4-(1,3-benzodioxol-5-ylcarbonyl)-3-[(R)-1-(1,3-benzo dioxol-5-yl)-1-hydroxy methyl]tetrahydro-2-furanone (6), and five known compounds (7-11)1,2). The structures of all isolated compounds were determined on the basis of their spectroscopic data and by comparison with the reported literatures. The absolute configurations of 1-3 and 5 were also determined by optical rotation and circular dichroism (CD) data analyses1). The anti-melanin deposition activities of all the isolated compounds were evaluated against B16-F10 cell line. 7,9-Dihydroxydolichanthin B (4) and ($2{\alpha},3{\alpha}$)-olean-12-en-28-oic acid (11) showed strong anti-melanin deposition activities with IC50 values of 18.4 and $11.2{\mu}M$, respectively, without cytotoxicity2). On the other hand, compounds 1-3, 5, and 7 showed melanogenesis enhancing activities1). To better understand their anti-melanin deposition mechanism, the effects of 4 and 11 on tyrosinase activities were investigated. The assay indicated that compounds 4 and 11 did not inhibit tyrosinase. Furthermore, we also examined the mRNA expression of microphthalmia-associated transcription factor (MITF), tyrosinase (TYR), tyrosinase-related protein-1 (TRP-1), and tyrosinase-related protein-2 (TRP-2). Compounds 4 and 11 down-regulated the expression of Tyr and Mitf mRNAs, respectively. Although the P. serratifolia wood has been used as traditional cosmetics in Myanmar for centuries, there are no scientific evidences to support its effectiveness as cosmetics. Investigation of the anti-melanin deposition activity of the chemical constituents of P. serratifolia thus provided insight into the effectiveness of the P. serratifolia wood as a cosmetic agent.

• Science of Emotion and Sensibility
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• v.21 no.4
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• pp.63-76
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• 2018

The purpose of this study was to investigate the effect of contact type textile electrode structure on heart activity signal acquisition for smart healthcare. In this study, we devised six contact type textile electrodes whose electrode size and configuration were manipulated for measuring heart activity signals using computerized embroidery. We detected heart activity signals using a modified lead II and by attaching each textile electrode to the chest band in four healthy male subjects in a standing static posture. We measured the signals four times repeatedly for all types of electrodes. The heart activity signals were sampled at 1 kHz using a BIOPAC ECG100, and the detected original signals were filtered through a band-pass filter. To compare the performance of heart activity signal acquisition among the different structures of the textile electrodes, we conducted a qualitative analysis using signal waveform and size as parameters. In addition, we performed a quantitative analysis by calculating signal power ratio (SPR) of the heart activity signals obtained through each electrode. We analyzed differences in the performance of heart activity signal acquisition of the six electrodes by performing difference and post-hoc tests using nonparametric statistic methods on the calculated SPR. The results showed a significant difference both in terms of qualitative and quantitative aspects of heart activity signals among the tested contact type textile electrodes. Regarding the configurations of the contact type textile electrodes, the three-dimensionally inflated electrode (3DIE) was found to obtain better quality signals than the flat electrode. However, regarding the electrode size, no significant difference was found in performance of heart signal acquisition for the three electrode sizes. These results suggest that the configuration method (flat/3DIE), which is one of the two requirements of a contact type textile electrode structure for heart activity signal acquisition, has a critical effect on the performance of heart activity signal acquisition for wearable healthcare. Based on the results of this study, we plan to develop a smart clothing technology that can monitor high-quality heart activity without time and space constraints by implementing a clothing platform integrated with the textile electrode and developing a performance improvement plan.

• Journal of Wetlands Research
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• v.25 no.2
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• pp.145-158
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• 2023

Constructed wetlands (CWs) are effective technologies for urban wastewater management, utilizing natural physico-chemical and biological processes to remove pollutants. This study employed a bibliometric analysis approach to investigate the progress and future research trends in the field of CWs. A comprehensive review of 100 most-recently published and open-access articles was performed to analyze the performance of CWs in treating wastewater. Spain, China, Italy, and the United States were among the most productive countries in terms of the number of published papers. The most frequently used keywords in publications include water quality (n=19), phytoremediation (n=13), stormwater (n=11), and phosphorus (n=11), suggesting that the efficiency of CWs in improving water quality and removal of nutrients were widely investigated. Among the different types of CWs reviewed, hybrid CWs exhibited the highest removal efficiencies for BOD (88.67%) and TSS (95.67%), whereas VSSF, and HSSF systems also showed high TSS removal efficiencies (83.25%, and 78.83% respectively). VSSF wetland displayed the highest COD removal efficiency (71.82%). Generally, physical processes (e.g., sedimentation, filtration, adsorption) and biological mechanisms (i.e., biodegradation) contributed to the high removal efficiency of TSS, BOD, and COD in CW systems. The hybrid CW system demonstrated highest TN removal efficiency (60.78%) by integrating multiple treatment processes, including aerobic and anaerobic conditions, various vegetation types, and different media configurations, which enhanced microbial activity and allowed for comprehensive nitrogen compound removal. The FWS system showed the highest TP removal efficiency (54.50%) due to combined process of settling sediment-bound phosphorus and plant uptake. Phragmites, Cyperus, Iris, and Typha were commonly used in CWs due to their superior phytoremediation capabilities. The study emphasized the potential of CWs as sustainable alternatives for wastewater management, particularly in urban areas.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.37 no.3
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• pp.196-213
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• 2001

A split beam ultrasonic transducer operating at a frequency of 70 kHz to use in the fish sizing echo sounder was developed and the acoustic radiation characteristics were experimentally analyzed. The amplitude shading method utilizing the properties of the Chebyshev polynomials was used to obtain side lobe levels below -20 dB and to optimize the relationship between main beam width and side lobe level of the transducer, and the amplitude shading coefficient to each of the elements was achieved by changing the amplitude contribution of elements with 4 weighting transformers embodied in the planar array transducer assembly. The planar array split beam transducer assembly was composed of 36 piezoelectric ceramics (NEPEC N-21, Tokin) of rod type of 10 mm in diameter and 18.7 mm in length of 70 kHz arranged in the rectangular configuration, and the 4 electrical inputs were supplied to the beamformer. A series of impedance measurements were conducted to check the uniformity of the individual quadrants, and also in the configurations of reception and transmission, resonant frequency, and the transmitting and receiving characteristics were measured in the water tank and analyzed, respectively. The results obtained are summarized as follows : 1. Average resonant and antiresonant frequencies of electrical impedance for four quadrants of the split beam transducer in water were 69.8 kHz and 83.0 kHz, respectively. Average electrical impedance for each individual transducer quadrant was 49.2$\Omega$ at resonant frequency and 704.7$\Omega$ at antiresonant frequency. 2. The resonance peak in the transmitting voltage response (TVR) for four quadrants of the split beam transducer was observed all at 70.0 kHz and the value of TVR was all about 165.5 dB re 1 $\mu$Pa/V at 1 m at 70.0 kHz with bandwidth of 10.0 kHz between -3 dB down points. The resonance peak in the receiving sensitivity (SRT) for four combined quadrants (quad LU+LL, quad RU+RL, quad LU+RU, quad LL+RL) of the split beam transducer was observed all at 75.0 kHz and the value of SRT was all about -177.7 dB re 1 V/$\mu$Pa at 75.0 kHz with bandwidth of 10.0 kHz between -3 dB down points. The sum beam transmitting voltage response and receiving senstivity was 175.0 dB re 1$\mu$Pa/V at 1 m at 75.0 kHz with bandwidth of 10.0 kHz, respectively. 3. The sum beam of split beam transducer was approximately circular with a half beam angle of $9.0^\circ$ at -3 dB points all in both axis of the horizontal plane and the vertical plane. The first measured side lobe levels for the sum beam of split beam transducer were -19.7 dB at $22^\circ$ and -19.4 dB at $-26^\circ$ in the horizontal plane, respectively and -20.1 dB at $22^\circ$ and -22.0 dB at $-26^\circ$ in the vertical plane, respectively. 4. The developed split beam transducer was tested to estimate the angular position of the target in the beam through split beam phase measurements, and the beam pattern loss for target strength corrections was measured and analyzed.

• Economic and Environmental Geology
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• v.12 no.3
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• pp.147-176
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• 1979

The Yeonhwa II zinc-lead mine is characterized by a dozen of moderately dipping tabular orebodies of skarn and zinc-lead sulfides, developed in accordance with the ENE-trending bedding thrusts and bedding planes of the Pungchon Limestone and underlying Myobong Formation, mostly along the contacts of a ENE-trending sill and a NW-trending dike of quartz mononite porphyry. The orebodies occur in three groups: (1) the footwall Wolgok orebodies with respect to the sill, (2) the hangingwall Wolgok orebodies, and (3) the Seongok orebodies extended from dike contacts into carbonate beds. Mineral compositions of these orebodies are dominated by calc-silicates (skarn) associated with ore minerals of sphalerite, galena, and chalcopyrite, as well as sulfide gangue of pyrrhotite. A pair of exo- and endo-skerns in the Wolgok footwall contact aureole between the Pungchon Limestone and quartz monzonite porphyry on the -120 level represents a well-developed symmetrical pattern of mineral zoning: a garnet/quartz zone in the center of exoskarn, two zones of pyroxene with ore minerals on both sides of the garnet/quartz zone, further outwards-an epidote/chlorite-bearing hornfelsic zone in the Myobong slate beyond a zone of unaffected limestone, and an epidote-dominated zone of endo skarn on the opposite side toward fresh quartz monzonite porphyry. These features indicate a combination of two effects on the skarn formation: (1) differences in composition of the host rocks(sedimentary and ignous), and (2) progressive outward migration of inner zones on outer zones on the course of metasomatic replacement of the pre-existing minerals. Microprobe analyses of garnet, pyroxene, pyroxenoids, epidote, and chlorite for nine major elements on a total of 23 mineral grains revealed that: the pyroxenes are hedenbergitic, in most zones, with a gradual decrease of Fe- and Mn-contents toward the central zone, whereas the garnets are andraditic in outer zones, but are grossularitic in the central zone. This indicates a reverse relationship of Fe-contents between pyroxene and garnet across the exoskarn zones. Pyroxenoids are lacking in wollastonite but are dominated by pyroxmangite, rhodonite and bustamite, indicating a Mn-rich nature in bulk chemistry. Pseudomorphic fluorite after garnet occurs abundantly reflecting a fluorine-enhanced evidence of the skarn-forming fluids. Epidote contains 0.19-0.25mole fraction of pistacite, and chlorite is Mn-rich but is Mg-poor. Sulfide mineralization took place with the most Fe-rich pyroxene rather than with garnet as indicated by the fact that the highest value of hedenbergite mole fraction occurs in the ore-bearing pyroxene zone. The Yeonhwa II ores are characterized by high zinc and low lead in metal grade, with minor quantity of copper content in almost constant grade. The hangingwall Wolgok and Seongok orebodies, that formed in a more open environment with respect to their local configurations of geologic setting, are more variable in metal grades and ratios, than are the footwall Wolgok orebodies formed in a more closed condition in a narrow interval of sedimentary beds.

• Journal of Biosystems Engineering
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• v.1 no.1
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• pp.15-15
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• 1976

In analyzing the operational characteristics of a rice whitening machine, the internal radial pressure of the machine was measured using strain gage equipment. Changes in cylinder and feed screw configurations, screen type, cylinder speed and counter-pressure levels were examined to determine their impact on the quality and quantity of milled rice and the performance of the machine. The results are summarized as follows: 1. The internal radial pressure in the whitening chamber varied with the surface condition of the grain being processed. During the first or second pass through the machine, pressure was relatively low, reached a maximum after two to three passes with combinations I and II, three to six with combination III and then began to fall. 2. The pitch of the feed screw and the size of the feed gate opening which determine the rate of entry of grain into the whitening chamber, appeared to be the most important factor aff-::cting the degree of radial pressure, quality and quantity of milled rice and the efficiency of the machine. Using a feed screw with a wide pitch (4.8cm), radial pressure was relatively high and head rice recovery ratio \vere quite low. In this case capacity and machine effic?iency were much higher than obtained when using a feed screw with a narrow pitch (2.3cm). Very significant responses in radial pressure, head rice recovery rates and machine capacity were observed with changes in cylinder speed and counter-pressure levels when using the wide pitch feed screw. 3. The characteristics of the screen which surrounds the whitening chamber had an important effect on whitening efficiency. The existence of small protuberances on the original screen resulted in significant increases in both machine capacity and efficiency but without a significant decrease in head rice recovery or development of excessive radial pressure. Further work is required to determine the effects of screen surface conditions and the shape of the cylinderical steel roller on the rate of bran removal, machine efficiency and recovery rates. The size of the slotted perforations 0:1 the screen affects total milled rice recovery. The opening size on the original screen was fabricated to accommodate the round shape of Japonica rice varieties but was not suitable for the more slender Indica type. Milling Indica varieties with this screen resulted in a reduction in total milled rice recovery. 4. An increase in cylinder speed from 380 to 820 rpm produced a positive effect on head rice recovery for all machine combinations at every level of counter-pressure used in the tests. Head rice recovery was considerably lower at 380rpm using a wide screw pitch when compared to the results obtained at speeds from 600 to 820 r.p.m. The effects of cylinder speed On radial pressure, capacity and machine efficiency showed contrasting results, depending on the width of the feed screw pitch. With a narrow feed screw pitch (2.3cm), a direct proportional relationship was observed bet?ween cylinder speed and both radial pressure and machine efficiency. In contrast, using a 4.8 centimeter pitch feed roller produced a series of inverse relationships between the above variables. Based on the results of this study it is recommended when milling Indica type long grain rice varieties that the cylinder speed of the original machine be increased from 500-600 rmp up to a minimum of 800 rpm to obtain a greater abrasive effect between the grain and the screen. The pitch of the feed screw should be also reduced to decr?ease the level of internal radial pressure and to obtain higher machine efficiency and increased quality of milled rice with increased cylinder speeds. Further study on the interaction between cylinder speed and feed screw pitch is recommended. 5. An increase in the counter pressure level produced a negative effect On the head rice recovery with an increase in radial pressure, capacity, and machine efficiency over all combinations and at every level of cylinder speed. 6. Head rice recovery rates were conditioned primarily by the pressure inside the whitening chamber. According to the empirical cha racteristics curve developed in this study, the relationships of head rice recovery ($Y_h$) and machine capacity ($Y_c$/TEX>) to internal radial pressure ($X_p$) followed an inverse quadratic function and a linear function respectively: $$Y_h^\Delta=\frac{1}{{1.4383-0.2951X_p^\ast+0.1425X_p^{\ast\ast}}^2} , (R^2=0.98)$$$$Y_c^\Delta=-305.83+374.37X_p^{\ast\ast}, (R^2=0.88)$$The correlation between capacity and power consumption per unit of brown rice expressed in the following exponential function: $$Y_c^\Delta=1.63Y_c^{-0.7786^\{\ast\ast}, (R^2=0.94)$$These relationships indicate that when radial pressure increases above a certain range (1. 6 to 2.0 kg/$cm^2$ based On the results of the experiment) head ricerecovery decrea?ses in a quadratic relation with a inear increase in capacity but without any decrease in power consump tion per unit of brown rice. On the other hand, if radial pressure is below the range shown above, power consumption increases dramatically with a lin?ear decrease in capacity but without significant increases in head rice recovery. During the operation of a given whitening machine, the optimum radial pressure range or the correct capacity range should be selected by controlling the feed rate and/or counter-pressure keeping in mind the condition of the grain, particulary the hardness. It was observed that the total number of passes is related to radial pessure level, feed rate and counter-pressure level. The higher theradial pressure the fewer num?ber of pass required but with decreased head rice recovery. In particular, when using high feed rates, the total number of passes should be increased to more than three by reducing the counter-pressure level to avoid decreaseases in head rice recovery (less than 65 percent head rice recovery on the basis of brown rice) at every cylinder speed. 7. A rapid rise in grain temperature seemed to have a close relationship with the pressure generated inside the whitening chamber and, subsequently with head rice reco?very rates. The higher the rate of increase, the lower were the resulting head rice recoveries.

• Journal of Biosystems Engineering
• /
• v.1 no.1
• /
• pp.17-48
• /
• 1976

In analyzing the operational characteristics of a rice whitening machine, the internal radial pressure of the machine was measured using strain gage equipment. Changes in cylinder and feed screw configurations, screen type, cylinder speed and counter-pressure levels were examined to determine their impact on the quality and quantity of milled rice and the performance of the machine. The results are summarized as follows: 1. The internal radial pressure in the whitening chamber varied with the surface condition of the grain being processed. During the first or second pass through the machine, pressure was relatively low, reached a maximum after two to three passes with combinations I and II, three to six with combination III and then began to fall. 2. The pitch of the feed screw and the size of the feed gate opening which determine the rate of entry of grain into the whitening chamber, appeared to be the most important factor aff-::cting the degree of radial pressure, quality and quantity of milled rice and the efficiency of the machine. Using a feed screw with a wide pitch (4.8cm), radial pressure was relatively high and head rice recovery ratio \vere quite low. In this case capacity and machine effic\ulcorneriency were much higher than obtained when using a feed screw with a narrow pitch (2.3cm). Very significant responses in radial pressure, head rice recovery rates and machine capacity were observed with changes in cylinder speed and counter-pressure levels when using the wide pitch feed screw. 3. The characteristics of the screen which surrounds the whitening chamber had an important effect on whitening efficiency. The existence of small protuberances on the original screen resulted in significant increases in both machine capacity and efficiency but without a significant decrease in head rice recovery or development of excessive radial pressure. Further work is required to determine the effects of screen surface conditions and the shape of the cylinderical steel roller on the rate of bran removal, machine efficiency and recovery rates. The size of the slotted perforations 0:1 the screen affects total milled rice recovery. The opening size on the original screen was fabricated to accommodate the round shape of Japonica rice varieties but was not suitable for the more slender Indica type. Milling Indica varieties with this screen resulted in a reduction in total milled rice recovery. 4. An increase in cylinder speed from 380 to 820 rpm produced a positive effect on head rice recovery for all machine combinations at every level of counter-pressure used in the tests. Head rice recovery was considerably lower at 380rpm using a wide screw pitch when compared to the results obtained at speeds from 600 to 820 r.p.m. The effects of cylinder speed On radial pressure, capacity and machine efficiency showed contrasting results, depending on the width of the feed screw pitch. With a narrow feed screw pitch (2.3cm), a direct proportional relationship was observed bet\ulcornerween cylinder speed and both radial pressure and machine efficiency. In contrast, using a 4.8 centimeter pitch feed roller produced a series of inverse relationships between the above variables. Based on the results of this study it is recommended when milling Indica type long grain rice varieties that the cylinder speed of the original machine be increased from 500-600 rmp up to a minimum of 800 rpm to obtain a greater abrasive effect between the grain and the screen. The pitch of the feed screw should be also reduced to decr\ulcornerease the level of internal radial pressure and to obtain higher machine efficiency and increased quality of milled rice with increased cylinder speeds. Further study on the interaction between cylinder speed and feed screw pitch is recommended. 5. An increase in the counter pressure level produced a negative effect On the head rice recovery with an increase in radial pressure, capacity, and machine efficiency over all combinations and at every level of cylinder speed. 6. Head rice recovery rates were conditioned primarily by the pressure inside the whitening chamber. According to the empirical cha racteristics curve developed in this study, the relationships of head rice recovery ($Y_h$) and machine capacity ($Y_c$/TEX>) to internal radial pressure ($X_p$) followed an inverse quadratic function and a linear function respectively: $$Y_h^\Delta=\frac{1}{{1.4383-0.2951X_p^\ast+0.1425X_p^{\ast\ast}}^2} , (R^2=0.98)$$ $$Y_c^\Delta=-305.83+374.37X_p^{\ast\ast}, (R^2=0.88)$$ The correlation between capacity and power consumption per unit of brown rice expressed in the following exponential function: $$Y_c^\Delta=1.63Y_c^{-0.7786^\{\ast\ast}, (R^2=0.94)$$ These relationships indicate that when radial pressure increases above a certain range (1. 6 to 2.0 kg/$cm^2$ based On the results of the experiment) head ricerecovery decrea\ulcornerses in a quadratic relation with a inear increase in capacity but without any decrease in power consump tion per unit of brown rice. On the other hand, if radial pressure is below the range shown above, power consumption increases dramatically with a lin\ulcornerear decrease in capacity but without significant increases in head rice recovery. During the operation of a given whitening machine, the optimum radial pressure range or the correct capacity range should be selected by controlling the feed rate and/or counter-pressure keeping in mind the condition of the grain, particulary the hardness. It was observed that the total number of passes is related to radial pessure level, feed rate and counter-pressure level. The higher theradial pressure the fewer num\ulcornerber of pass required but with decreased head rice recovery. In particular, when using high feed rates, the total number of passes should be increased to more than three by reducing the counter-pressure level to avoid decreaseases in head rice recovery (less than 65 percent head rice recovery on the basis of brown rice) at every cylinder speed. 7. A rapid rise in grain temperature seemed to have a close relationship with the pressure generated inside the whitening chamber and, subsequently with head rice reco\ulcornervery rates. The higher the rate of increase, the lower were the resulting head rice recoveries.