• 제목/요약/키워드: Root density

검색결과 720건 처리시간 0.031초

화강암질풍화토(花崗岩質風化土)의 역학적(力學的) 성질(性質)에 관(關)한 연구(硏究) -전단강도(剪斷强度)의 영향요소(影響要素)와 견밀도(堅密度)에 대(對)하여- (Studies on the Mechanical Properties of Weathered Granitic Soil -On the Elements of Shear Strength and Hardness-)

  • 조희두
    • 한국산림과학회지
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    • 제66권1호
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    • pp.16-36
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    • 1984
  • 화강암질풍화토(花崗岩質風化土)의 미교란(未攪亂) 시료(試料)를 사용하여 일면(一面) 직접(直接) 전단시험(剪斷試驗)으로 측정(測定)한 전단강도(剪斷强度)와 함수비(含水比), 간극비(間隙比), 건조밀도(乾燥密度), 비중(比重)과의 관계(關係)를 통계(統計) 분석(分析)하였고, 화강암질풍화토(花崗岩質風化土)의 사방시공지(砂防施工地)에 식재(植栽)된 리기다소나무림(林)과 리기테-다소나무림(林)에서 토양단면(土壤斷面)을 만들어 산중식토양경도계(山中式土壤硬度計)로 토양(土壤)의 견밀도(堅密度)를 측정(測定)하고 수근분포(樹根分布)를 조사(調査)하여 통계(統計) 분석(分析)한 결과(結果) 다음과 같다. 1) 함수비(含水比), 간극비(間隙比)와 전단강도(剪斷强度) 간(間)에는 유의적(有意的)인 부(負)의 상관(相關)이며 직접적(直接的)인 관계(關係)에 있었다. 2) 건조밀도(乾燥密度)와 전단강도(剪斷强度) 사이에는 정(正)의 상관(相關)이며 직접적(直接的)인 관계(關係)에 있었다. 3) 비중(比重)과 전단강도(剪斷强度) 간(間)에는 유의적(有意的)인 상관관계(相關關係)를 인정(認定)할 수 없었다. 4) 전단강도(剪斷强度)에 영향(影響)을 미치는 영향요소(影響要素)의 직접효과(直接效果)의 크기는 함수비(含水比)>간극비(間隙比)>건조밀도(乾燥密度)의 순위(順位)이다. 5) 다중선형(多重線型) 회귀방정식(回歸方程式)의 분산분석결과(分散分析結果) 함수비(含水比)만이 회귀성(回歸性)이 인정(認定)되므로 함수비(含水比)를 독립변수(獨立變數)로 하여 전단강도(剪斷强度)를 추정(推定)하기 위한 회귀방정식(回歸方程式)은 제한(制限)된 건조밀도(乾燥密度)의 범위내(範圍內)에서 적합도(適合度)가 매우 높게 평가(評價)되었다. 6) 토양(土壤)의 견밀도(堅密度)는 토심(土深)이 깊어짐에 따라 높아진다. 7) 토양(土壤)의 지표경도(指標硬度)와 수근수(樹根數) 간(間)에는 유의적(有意的)인 부(負)의 상관(相關)이며 직접적(直接的)인 관계(關係)에 있었다. 8) 리기다소나무와 리기테-다소나무의 수근(樹根)은 토심(土深) 20cm까지에 대부분 분포(分布)하고 있었다. 9) 리기다소나무림(林)과 리기테-다소나무림(林)에서 측정(測定)한 토양(土壤)의 지표경도(指標硬度)를 독립변수(獨立變數)로한 회귀방정식(回歸方程式)으로 수근수(樹根數)를 추정(推定)할 수 있었으나 낮은 적합도(適合度)를 나타내었다.

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다양한 규격의 포트에서 코이어더스트를 포함한 혼합상토의 충전밀도 차이에 의해 유발된 물리성 변화 (Changes in Soil Physical Properties in Various Sizes of Container as Influenced by Packing Amount of Coir Dust Containing Root Media)

  • 박은영;최종명
    • 원예과학기술지
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    • 제31권6호
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    • pp.720-725
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    • 2013
  • 수축성이 강한 코이어더스트가 주요 구성물질로 조제된 혼합상토는 충전량에 따라 용기내의 밀도가 달라지고 결과적으로 공극률(TP), 기상률(AFP) 및 용기용수량(CC)의 상대적인 비율이 변화된다. 따라서 충전량 차이에 따라 변화된 상토의 물리성 변화를 구명하여 작물 재배를 위한 기초자료로 제시하고자 본 연구를 수행하였다. 연구 목적을 달성하기 위해 코이어더스트 + 팽연왕겨(8:2, v/v; coir dust + expanded rice hull, CD + ERH로 지칭), 코이어더스트 + 훈탄(6:4; coir dust + carbonized rice hull, CD + CRH), 그리고 코이어더스트 + 분쇄된 수피(8:2; coir dusts + ground and raw pine bark, CD + GRPB)의 세 종류 상토를 조제하였다. 이 후 직경이 6.0, 7.5, 8.5, 10.5 및 12.5cm의 포트에 최적 가비중을 기초로 90, 100, 110, 120 및 130%가 되도록 상토 충전량을 조절한 후 TP, AFP 및 CC 변화를 측정하였다. 모든 규격의 포트에서 상토 충전량이 많아질수록 TP가 감소하였지만 CD + GRPB 상토보다 CD + ERH 또는 CD + CRH 상토의 감소 정도가 컸다. 상토 충전량이 많아질 경우 CC도 감소하였지만, 동일한 충전 비율에서 포트의 크기가 커질수록 CC의 감소한 정도가 컸다. 상토 충전량이 많아질수록 AFP도 뚜렷하게 감소하였다. 그러나 포트의 직경이 7.5cm보다 적을 때에는 동일한 충전 비율에서 CD + CRH 상토의 AFP가 가장 높았고, 포트의 크기가 8.5cm 이상으로 커질 경우 CD + ERH 상토의 AFP가 가장 높았다. 본 연구에서 상토 충전량 증가는 CC보다 AFP에 더 심한 영향을 미쳤으며 근권부의 가스 교환이 작물 생육에 큰 영향을 미침을 고려할 때 AFP의 감소를 방지할 수 있도록 충전량을 조절해야 한다고 판단하였다. 본 연구 결과는 상토를 이용한 용기재배에서 충전량 차이에 따른 물리성 변화를 예측하기 위한 자료로 활용될 수 있을 것이다.

세척인삼 유통 현황과 포장전 2-phenylethyl Alcohol 훈증이 저장성에 미치는 영향 (Marketing of cleaned fresh ginseng and pre-packaging fumigation of 2-phenylethyl alcohol on ginseng storability)

  • 김선익;성봉재;김현호;황용수
    • 농업과학연구
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    • 제38권2호
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    • pp.205-212
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    • 2011
  • The potential factors for quality loss of cleaned fresh ginseng and technology to be associated with the improvement of marketability through pre-packaging fumigation were examined. Major microorganisms isolated from fresh ginseng included Botrytis cinerea, and Erwinia sp. Others such as Cylindrocarpon sp., Fusarium spp., Pennicilium spp., Bacillus spp. were also found at relatively low frequency. The bacterial density of vacuum packaged fresh ginseng rapidly increased during simulated marketing. Little correlation between bacterial growth and package swelling was found. In order to improve packaging method of fresh ginseng, pre-packaging treatment of 2-phenylethyl alcohol (PE, 100 uL/L, 4 hr) was examined. The fumigation treatment effectively inhibited the growth of bacteria density and also effective on keeping firmness of ginseng root, especially in cortical portion. The internal gas compositions of plastic container packaged for ginseng were approximately ranged between 6 to 8% $O_2$and 3 to 4% $CO_2$. The $O_2$ level of fumigation treatment was lower than control whereas $CO_2$ level was higher. The upsurge of ethylene evolution I day after simulated marketing was found only in fumigation treatment but it returned to ordinary level at day 2. The sucrose content of 2-PE treatment was significantly reduced at 5 days after simulated marketing but reducing sugars like glucose and fructose remained at higher level. The difference in sugar levels was reduced after 10 days of simulated marketing. The decay of fresh ginseng began at the lateral or fine root, which is weak to physical damage, in general. The epidermis was more damaged. Plastic container packaging with PE fumigation could be an alternative to vacuum packaging, which allows an aerobic environment and prevents anaerobic respiration. Further study of pre-package fumigation is required to improve technology of fresh ginseng marketing.

Aristolochia ringens extract ameliorates oxidative stress and dyslipidaemia associated with streptozotocin-induced hyperglycaemia in rats

  • Sulyman, Abdulhakeem Olarewaju;Akolade, Jubril Olayinka;Aladodo, Raliat Abimbola;Ibrahim, Rasheed Bolaji;Na'Allah, Asiat;Abdulazeez, Azeemat Titilola
    • 셀메드
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    • 제8권3호
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    • pp.12.1-12.7
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    • 2018
  • The study was designed to assess antioxidant and antidyslipidaemic effects of terpenoid-rich extract from the root of Aristolochia ringens V. Hyperglycemia-induced oxidative stress and dyslipidemia were established in rats by single intraperitoneal administration of 65 mg/kg bw streptozotocin. Based on therapeutic dose determined in previous study, streptozotocin-induced rats were orally administered with 75 and 150 mg/Kg bw of A. ringens extract for 14 days. Total protein, serum lipid profiles and biomarkers of oxidative stress in liver and kidney of the experimental rats were determined. Atherogenic and cardiovascular disease risk indices were computed. Streptozotocin-induced hyperglycaemia significantly (p < 0.05) decreased activities of superoxide dismutase, catalase and glutathione transferase as well as the amount of reduced glutathione in both tissues indicating oxidative stress induced kidney and liver injury due to glucotoxicity. In comparison to non-treated hyperglycaemic rats, activities of the antioxidant enzymes and concentration of glutathione-H were significantly (p < 0.0001) increased, whereas malondialdehyde was reduced in the tissues of rats treated with both 75 and 150 mg/Kg bw of the extract. The extract also caused significant (p < 0.001) reduction in elevated levels of total cholesterol, triglycerides and low density lipoprotein-cholesterol levels, whereas concentration of the attenuated high density lipoprotein-cholesterol was increased in serum of the treated rats. Reduced atherogenic and cardiac risk indices were projected for the A. ringens extract-treated groups. Results from this study showed that extract from A. ringens root was rich in terpenoids and may reduce risks of complications associated with hyperglycemia-induced oxidative stress and dyslipidemia.

골프장에 적합한 켄터키 블루그래스 품종 선발 (Selection of Kentucky Bluegrass(Poa pratensis L.) Cultivar for Golf Courses in Korea)

  • 김경덕;태현숙;김종보;장재일;오성배
    • 한국조경학회지
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    • 제35권1호
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    • pp.88-93
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    • 2007
  • Since the 1990s, the application of Kentucky bluegrass cultivars has increased in newly-constructed Korean golf courses as opposed to the previously-used zoysiagrass. However, there have been few reports studying the selection and characterization of these Kentucky bluegrass cultivars under Korean weather conditions. A total of 12 Kentucky bluegrass cultivars were tested for their adaptability in environmental stresses during summer conditions in Korea in order to select the best Kentucky bluegrass cultivars for use in Korean golf courses. This study found that two Kentucky bluegrass cultivars ('Midnight' and 'Bluestone') maintained their green throughout the summer season and had a high degree of root density, as compared to the other cultivars tested. These two cultivars also had a good rate of coverage in the early growth period. These characteristics make them suitable for application on sports fields and golf courses, which receive many divots and the frequent replacement of turfgrass sod caused by both biotic and abiotic stress. Two other cultivars, the 'Ginney' and 'Nuglade', also displayed good visual quality and high rate of coverage under summer conditions. In conclusion, the 'Midnight' and 'Bluestone' cultivars performed well in areas including the maintenance of their green color, the number of roots and the rate of coverage during the summer months. These characteristics are necessary for golf courses sports fields, which receive many divots and requirethe frequent replacement of turfgrass. further research on a range of Kentucky bluegrass cultivars, including a sensitivity test for many pathogens and recovery rates from a variety of stresses, is required in the near future.

Theory and Practices of Water Pollution Control by Wetland - a Case Study of Reed Wetland in Baiyangdian Lake

  • Li, Guibao;Zhou, Huaidong;Liu, Fang;Wang, Dianwu
    • 한국수자원학회:학술대회논문집
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    • 한국수자원학회 2004년도 학술발표회
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    • pp.72-76
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    • 2004
  • Wetland is an important eco-system on the earth and can effectively control agricultural non-point source pollution. Reed is a typical wetland plant for land/inland water ecotone in north China. The studies indicated that reed had a underground rooted-stem, which formed a 'high speeded-connecting vessels' i.e. reed root channel (RRC) in Baiyangdian lake of Hebei province. It spread predominantly along horizontal direction underground and are mainly distributed at 18-75 cm. The results of field work from healthy reed-wetland (HRW) and regarded reed-wetland (RRW) showed that the reed, averagely, in HRW is 4.2 m height, 1 cm diameter, 65/m2 density; in RRW is 2.4 m height, 3 mm diameter, 86/m2 density. These results indicated the regradation of the function of RRC in RRW. The results of laboratory work of sewage purification from reed soil column (RSC) $(0\~100cm)$ and wheat soil column (WSC) showed that the efficiency of purification to sewage, in RSC, is high than in WSC, especially for phosphorus. The efficiency of purification, in RSC, is $92.6\%$ for total phosphorus, $43.5\%$ for total nitrogen, $54.1\%$ fur COD, respectively; in WSC, is $86.0\%$ for total phosphorus, $241.3\%$ for total nitrogen, $29.8\%$ for COD, respectively.

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Anti-hyperlipidemic Effect of Vitex doniana Ethanol Extract in Poloxamer Induced Hyperlipidemia

  • Sheneni, Victor Duniya;Idakwoji, Precius Adejoh
    • 식품보건융합연구
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    • 제4권4호
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    • pp.1-9
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    • 2018
  • To determine the effect of Vitex doniana (leaves stem and root bark) ethanolic extracts on lipid profiles of Poloxamer 407 (P407) induced hyperlipidemic and normal rats. Fifty four mixed sex rats weighing 100-200g were divided into nine groups comprising six animals per group. At the end of the 21 day, the animals were sacrificed and blood sample were collected for determination of serum levels of: Total cholesterol (TC), Triacylglycerides (TAG), High-density lipoprotein cholesterol (HDL-c) and Low-density lipoprotein cholesterol (LDL-c). The studies showed that all induced treated groups significantly (P<0.05) lower serum levels of TC, TAG, LDL-c and significantly (P<0.05) increased HDL-c when compared to the P407 induced hyperlipidemic control. The normal treated groups showed no significant (P>0.05) difference in the serum levels of TC, TAG, LDL and HDL when compared to the normal control group. Calculation of atherogenic risk predictor indices of the induced treated groups showed that all the extracts significantly (P<0.05) lowered the LDL-c/HDL-c, log (TAG/HDL-c) and significantly (P<0.05) increased HDL-c/TC ratio when compared to the P407 induced hyperlipidemic control group. The atherogenic risk predictor indices of normal treated groups showed no significant difference (P>0.05) in LDL-c/HDL-c, Log (TAG/HDL-c) and HDL-c/TC ratio when compared to the normal control group. The study demonstrates the phytotherapeutic effect of Vitex doniana (leaves, stem and root bark) ethanolic extract in poloxamer 407 induced hyperlipidemia.

감귤선충 (Tylenchulus semipenetrans) 에 대한 DBCP 유제처리효과 (On the Effects of Emulsifiable DBCP for Control of the Citrus-root Nematode, Tylenchulus semipenetrans in Two Citrus Orchards)

  • 이영배;한상찬;박중수
    • 한국응용곤충학회지
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    • 제14권3호
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    • pp.141-146
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    • 1975
  • 감교선출(Tylenchulus semipenetrans)에 대한 DBCP(Dibromo chloropropane) $80\%$ 유제의 처리방법 및 약량과 회수를 규명코저 시험하여 아래와 같은 결과를 얻었다. 1. 약량의 증가에 다라, 점주가 관주처리보다 좋은 효과를 보였다. 2. 온주귤원에서는 배수가 나빠서 2회처리로서 좋은 효과를 볼 수 있었다. 3. 점토함량이 낮은 하귤원에는 3.3-4.4l/10a의 1회점주처리가, 점토함량이 높은 온주귤원에는 4.4l/10a씩 2회점주처리가 좋았다.

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백가수도의 재식밀도에 따른 생육 및 수량 (Effect of Planting Density on Growth and Yield in Cyanachum wilfordii)

  • 최인식
    • 한국자원식물학회지
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    • 제8권2호
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    • pp.209-215
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    • 1995
  • 중부(中部) 내륙지방(內陸地方)에서 백하수오(白何首烏) 재배시(栽培時) 적정(適正) 재식밀도(栽植密度)를 구명(究明)하고자 충북(忠北) 지방(地方) 재래종(在來種)을 공시(供試)하여 10a당(當) 시비(施肥)는 웅비(施肥) 1,000kg, N-P-K=8-4-4kg을 전량(全量) 기비(基肥)로 시용(施用)하였다. 처리(處理)는 휴폭(畦幅)을 주구(주구)로, 주간(株間)을 세구(細區)로 하여, 휴폭(畦幅)은 40, 50, 60cm, 주간(株間)은 10, 15, 20cm로 하여 분류구배치(分劉區配置) 3반복(反復)으로 시험(試驗)을 수행(遂行)하였던 결과(結果)를 요약(要約)하면 다음과 같다. 1. 출현기(出現期)는 5월(月) 25일(日)로 처리간(處理間)에 차이가 없이 균일(均一)하였다. 2. 위장(萎長)은 휴폭간(畦幅間)에서 40cm는 219cm, 50cm는 220cm, 60cm는 225cm 였으나, 주간(株間)에는 10cm에서 225cm, 15cm는 219cm, 20cm는 218cm로 주간(株間)이 좁을수록 길었으며, 엽수(葉數)는 양장(養長)과 같은 경향(傾向)으로, 주간(株間)이 좁으면 엽수(葉數)는 증가(增加)되었다. 3. 근장(根長)은 휴폭(畦幅) 40cm에서 24.5cm, 50cm는 24.6cm, 60cm는 24.2cm로 큰 차이가 없으나, 주간(株間) 10cm에서 23.5cm, 24.4cm, 20cm는 24.9cm로, 주간(株間)이 넓을수록 $0.9\sim1.4cm$가 길었으며, 근수(根數)는 $1.2\siml.4$ 개(個)로 처리간(處理間)에 큰 차이가 없는 경향(傾向)이었다. 4, 10a당(當) 수양(收量)은 휴폭(畦幅) 40cm의 395kg/10a에 비(比)하여 50cm는 11%, 60cm는 4%가 각각(各各) 증수(增收)되었으나, 주간(株間) 10cm의 495kg/10a에 비(比)하여, 15cm는 17%, 20cm는 32%가 각각(各各) 감수(減收)되어, 중부(中部) 내륙지방(內陸地方)에서 백하수오(白何首烏) 재배시(栽培時) 재식밀도(栽植密度)는 휴폭(畦幅) 50cm, 주간(株間) l0cm로 재배(栽培)하는 것이 효과적(效果的)이었다.

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Nd:YAG 레이저조사가 치경부 백악질에 미치는 영향에 관한 주사전자현미경적 연구 (A Scanning Electron Microscopic Study on the Effect of Nd:YAG Laser Irradiation on the Cervical Cementum)

  • 최복;이정연;신금백
    • Journal of Oral Medicine and Pain
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    • 제25권4호
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    • pp.415-425
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    • 2000
  • In order to obtain the basic data concerning the optimal lasing conditions in using Nd:YAG laser as an adjunctive modality of periodontal therapy of root planing without irreversible structural deterioration of cervical cementum, the author selected 36 human teeth having no cervical abrasion and caries (; 12 anteriors, 12 premolars. 12 molars) extracted due to periodontal diseases, and divided them into 4 groups as Group I, II, III and IV (; each group of 3 anteriors, 3 premolars, 3 molars), and prepared a cementum specimen with thickness of $1.0mm{\pm}0.2mm$ sectioned longitudinally at the middle of mesio-distal thickness (; Group I) or horizontally at 1mm-2mm below the cemento-enamel junction (; Group II, III, IV) from each tooth of each group by low speed diamond wheel saw, and treated them with 0.5 M ethylene diamine tetraacetic acid (; EDTA, pH=7.4) for 2 minutes for elimination of remnants during tooth-sectioning. And the author applied the laser energy from a fiberoptic delivered, free running, pulsed Nd:YAG laser (; wavelength 1064nm. pulse duration $120{\mu}sec$, fiber diameter $320{{\mu}m}$) to cementum surfaces in triplicates of one experiment under the following lasing conditions: 1. stationary mode of fiber in contact to cementum surfaces without air-spray (; Group I )/with air-spray (; Group II), 2. unidirectional moving mode of fiber in contact to cementum surfaces under speed of 3mm-4mm/sec without air-spray (; Group III)/with air-spray (; Group IV), 3. energy per pulse (mJ/pulse) [; energy density ($J/cm^{2}$)] in order of 1.0W/10Hz (100J/pulse); $124J/cm^{2}$, 0.5W/10Hz (50mJ/pulse); $62J/cm^{2}$, 0.4W/10Hz (40mJ/pulse); $50J/cm^{2}$, 0.3W/10Hz (30mJ/pulse); $37J/cm^{2}$, 4. exposure time of 1 second. And the author applied the platinum coating on surfaces of cementum specimens, and evaluated the characteristics of ultrastructural change on surfaces of cementum using the scanning electron microscopy. In general the ultrastructural loss of cervical cementum irradiated under the same lasing condition of laser energy density occurred least in specimens of Group IV. And especially, the ultrastructural loss of cervical cementum irradiated under the laser energy density of $37J/cm^{2}$ almost did not occur in specimens of Group IV. Therefore, it is considered that the pulsed Nd:YAG laser should be applied with the lasing conditions of unidirectional moving mode of fiber in contact to cementum surfaces under speed of 3mm-4mm/sec with air-spray and of laser energy density within $37J/cm^{2}$ as an adjunctive modality of periodontal therapy of root planing without irreversible structural deterioration of cervical cementum.

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