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Simulation of Water Movement in Rockwool Slab as Soil-less Cultivation Using HYDRUS (HYDRUS를 이용한 작물재배용 암면배지에서의 수분 이동 시뮬레이션)

  • Dong-Hyun Kim;Jong-Soon Kim;Soon-Hong Kwon;Jong-Min Park;Won-Sik Choi
    • Journal of the Korean Society of Industry Convergence
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    • v.26 no.1
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    • pp.153-162
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    • 2023
  • It is important to determine water movement at the growing substrate used in soil-less cultivation for better management of water supply. Numerical simulation is a fast and versatile approach to evaluate highly accurate water distribution. The objective of this study is to simulate the water movement in rockwool as a soil-less medium using HYDRUS-2D. HYDRUS-2D was used to simulate the spatial and temporal water movement in two types of rockwool slabs (Floriculture (FL), high density; Expert (EP), low density). The simulation was performed at two pulse conditions: 10 min ON and 50 min OFF (case A), 20 min ON and 40 min OFF (case B). The total irrigation amounts were the same at both cases. In case A, during the irrigation ON, the water contents at FL increased 1.93-fold faster than the values at EP. Whereas, during the irrigation OFF, the decreasing rate of water contents at FL was almost the same as one at EP. At case B, these values were not changed much from case A. However, the duration of optimum water content (50% - 80%) was 15.0 min and 23.5 min at case A and case B, respectively. Thus, FL and 20 min ON and 40 min OFF (case B) could supply water to rockwool much faster and longer than EP. Once qualitatively validated, this simulation of water movement in rockwool could be used to design an effective optimum irrigation method for vegetables.

The Effect of Hand Massage on Pain and Anxiety Related to Chest Tube Removal in Patients with a Lobectomy (손마사지가 폐엽 절제술 환자의 흉관 제거시 통증과 불안에 미치는 영향)

  • Song Yeoung-Suk
    • Journal of Korean Academy of Fundamentals of Nursing
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    • v.9 no.1
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    • pp.27-44
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    • 2002
  • The main purpose of this study was to identify the effect of hand massage on pain and anxiety related to chest tube removal in patients with a lobectomy. The research design of this study was a nonequivalent control group non-synchronized design. Of the twenty nine adult subjects, fourteen were assigned to the experimental group and fifteen to the control group. The data were obtained over 3 months from a medical center in Seoul. The instruments used to assess trait state anxiety was the Spielberger Trait-State anxiety Inventory. For pain and psychological anxiety. The Visual Analogue Scale was used. Hiko analogue sphygmo-manometer(2001) was used to check blood pressure and pulse rate as indicators of physiological anxiety Subjects in the experimental group received hand massage for 5 minutes just before chest tube was removed, and subjects assigned to the control group did not receive hand massage. Data were analysed with x2-test and Mann-Whitney U test using the SPSSWIN 10.0 program. The results of the study are as follows : 1. Hypothesis 1: 'there will be a significant difference between two groups in the level of pain after chest tube removal' was supported (u = 23.00, p < 0.001). 2. Hypothesis 2: 'there will be a significant difference between the two groups in the level of psychological anxiety after chest tube removal' was supported (u = 3.00, p < 0.001). 3. Hypothesis 3: 'there will be a significant difference between the two groups in physiological anxiety(systolic, diastolic blood pressure and pulse rate) after chest tube removal' was supported(u =55.50, p = 0.01 ; u = 41.50, p = 0.01 ; u = 20.50, p < 0.001, relatively). The findings of this study indicate that hand massage is effective for pain and anxiety related to chest tube removal in patients with lobectomy. Therefore, hand massage is recommended as an effective nursing intervention for relieving pain and anxiety in patients undergoing chest tube removal. Further research is needed to identify the proper duration and timing to achieve the optimal effect of hand massage. A larger subject population is required to apply the current findings to the general population. Further research is also needed to assess the effects of hand massage in other patient subsets. Finally, it would be interesting to see if the effects of hand massaging would be attenuated when performed by a non-medical specialist.

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A Study on the Electrical Characteristics of Ge2Sb2Te5/Ti/W-Ge8Sb2Te11 Structure for Multi-Level Phase Change Memory (다중준위 상변환 메모리를 위한 Ge2Sb2Te5/Ti/W-Ge8Sb2Te11 구조의 전기적 특성 연구)

  • Oh, Woo-Young;Lee, Hyun-Yong
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.35 no.1
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    • pp.44-49
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    • 2022
  • In this paper, we investigated current (I)- and voltage (V)-sweeping properties in a double-stack structure, Ge2Sb2Te5/Ti/W-doped Ge8Sb2Te11, a candidate medium for applications to multilevel phase-change memory. 200-nm-thick and W-doped Ge2Sb2Te5 and W-doped Ge8Sb2Te11 films were deposited on p-type Si(100) substrate using magnetron sputtering system, and the sheet resistance was measured using 4 point-probe method. The sheet resistance of amorphous-phase W-doped Ge8Sb2Te11 film was about 1 order larger than that of Ge2Sb2Te5 film. The I- and V-sweeping properties were measured using sourcemeter, pulse generator, and digital multimeter. The speed of amorphous-to-multilevel crystallization was evaluated from a graph of resistance vs. pulse duration (t) at a fixed applied voltage (12 V). All the double-stack cells exhibited a two-step phase change process with the multilevel memory states of high-middle-low resistance (HR-MR-LR). In particular, the stable MR state is required to guarantee the reliability of the multilevel phase-change memory. For the Ge2Sb2Te5 (150 nm)/Ti (20 nm)/W-Ge8Sb2Te11 (50 nm), the phase transformations of HR→MR and MR→LR were observed at t<30ns and t<65ns, respectively. We believe that a high speed and stable multilevel phase-change memory can be optimized by the double-stack structure of proper Ge-Sb-Te films separated by a barrier metal (Ti).

Frequency Dependent Electroacupuncture Modulates the Visceromotor Responses to Colonic Distension in TNBS-Induced Colonic Inflammatory Rats (흰쥐의 급성 대장염에 대한 주파수에 따른 전침 효과 연구)

  • Choi, Yun-Young;Yang, Seung-Bum;Ahn, Sung-Hun;Sohn, In-Chu;Kim, Jae-Hyo
    • Korean Journal of Oriental Medicine
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    • v.17 no.3
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    • pp.105-114
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    • 2011
  • Objectives : The transient inflammation has been demonstrated to alter visceral motor response (VMR) and acute mucosal inflammation may precede the manifestation of visceral hyperalgesia in animal models. The purpose of our study is to compare effects of the different frequencies applied electroacupuncture (EA) on acupoints in acute colitis induced by trinitrobenzenesulphonic acid (TNBS). Methods : In Male Sprague-Dawley rats, weighing 250~400g, a single colorectal administration of TNBS (5mg/kg) was made and electrode for electromyography (EMG) recording were stitched into the external oblique musculature. EA of either ST25 or ST36 were applied and stimulation parameter was modulated as follows: 2, 10, or 100 Hz with intensity of 2 mA and 1 ms pulse duration for 30 min. The balloon was inserted intra-anally and VMR to colorectal distension (CRD) was quantified with an EMG recording system. Results : The VMR increased significantly 3 days after TNBS intra-rectal colonic injection in rats. Both 2 Hz and 10 Hz EA on ST36 suppressed VMR to CRD in the acute colitis model but not 100 Hz. Only 10 Hz EA on ST25 suppressed VMR to CRD in the acute colitis. Conclusions : These data show that 10 Hz EA potently inhibits hypersensitivity of colorectum after TNBS induced colitis.

Optimization of Electrofusion Condition for the Production of Korean Cattle Somatic Cell Nuclear Transfer Embryos

  • Kim, Se-Woong;Kim, Dae-Hwan;Jung, Yeon-Gil;Roh, Sang-Ho
    • Reproductive and Developmental Biology
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    • v.35 no.1
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    • pp.17-22
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    • 2011
  • This study was designed to determine the effect of electric field strength, duration and fusion buffer in fusion parameters on the rate of membrane fusion between the somatic cell and cytoplast for Korean cattle (HanWoo) somatic cell nuclear transfer (SCNT) procedure. Following electrofusion, effect of 5 or 10μM Ca2+-ionophore of activation treatment on subsequent development was also evaluated. Cell fusion rates were significantly increased from 23.1% at 20 V/mm to 59.7% at 26 V/mm and 52.9% at 27 V/mm (p<0.05). Due to higher cytoplasmic membrane rupture or cellular lysis, overall efficiency was decreased when the strength was increased to 30 V/mm (18.5%) and 40 V/mm (6.3%) and the fusion rate was also decreased when the strength was at 25 V/mm or below. The optimal duration of electric stimulation was significantly higher in 25μs than 20 and 30μs (18.5% versus 9.3% and 6.3%, respectively, p<0.05). Two nonelectrolyte fusion buffers, Zimmermann's (0.28 M sucrose) and 0.28 M mannitol solution for cell fusion, were used for donor cell and ooplast fusion and the fusion rate was significantly higher in Zimmermann's cell fusion buffer than in 0.28 M mannitol (91.1% versus 48.4%, respectively, p<0.05). The cleavage and blastocyst formation rates of SCNT bovine embryos activated by 5μM Ca2+-ionophore was significantly higher than the rates of the embryos activated with 10μM of Ca2+-ionophore (70.0% versus 42.9% and 22.5% versus 14.3%, respectively; p<0.05). This result is the reverse to that of parthenotes which shows significantly higher cleavage and blastocyst rates in 10μM Ca2+-ionophore than 5μM counterpart (65.6% versus 40.3% and 19.5% versus 9.7%, respectively; p<0.05). In conclusion, SCNT couplet fusion by single pulse of 26 V/mm for 25μs in Zimmermann's fusion buffer followed by artificial activation with 5μM Ca2+-ionophore are suggested as optimal fusion and activation methods in Korean cattle SCNT protocol.

Comparison of the Therapeutic Efficacy of Methylprednisolone Pulse Therapy and Oral Steroid Therapy in Children with IgA Nephropathy and HSP Nephritis Combined with Proteinuria (단백뇨를 동반한 IgA 신병증 및 HSP 신염을 가진 소아에서 메틸프레드니솔론 충격요법과 경구 스테로이드 요법의 비교)

  • Ahn, Ji Young;Moon, Jung Eun;Hwang, Young Ju;Choi, Bong Seok;Ko, Cheol Woo;Cho, Min Hyun
    • Childhood Kidney Diseases
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    • v.18 no.1
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    • pp.24-28
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    • 2014
  • Purpose: The purpose of this study was to assess the therapeutic efficacy of methylprednisolone pulse therapy in children with IgA nephropathy and Henoch- Sch¨onlein Purpura (HSP) nephritis combined with proteinuria. Methods: We retrospectively reviewed the clinical records of 21 patients who were diagnosed with IgA nephropathy and HSP nephritis based on percutaneous renal biopsy. Of the 21 patients, 15 were diagnosed with IgA nephropathy and 6 were diagnosed with HSP nephritis. They had mild to severe proteinuria at the time of diagnosis or during follow-up. Group 1 (n=7) received methylprednisolone pulse therapy three times every couple of months, and Group 2 (n=14) received oral steroid therapy. The follow-up periods for Group 1 and 2 were 14.0 (9-54) months and 26.5 (14-34) months, respectively. There was no significant difference in the follow-up duration between the two groups. Results: The average age at diagnosis and biopsy was lower in Group 1 compared to Group 2, but it was not significantly different. At admission, all patients in both groups had hematuria and 5 patients (71.4%) of Group 1 and 14 patients (100 %) of Group 2 had proteinuria. Before treatment, there was no significant difference of spot urine protein/creatinine ratio between the two groups. During followup, 7 patients of Group 1 (100%) and 10 patients of Group 2 (71.4%) showed complete improvement of proteinuria and the spot urine protein/creatinine ratio in Group 1 was significantly lower than Group 2. Conclusion: In patients with IgA nephropathy and HSP nephritis with proteinuria, methylprednisolone pulse therapy was more effective than oral steroid therapy in the reduction of proteinuria. To investigate the effects on long-term prognosis, large-scale prospective studies are needed.

Improvement of PENS on Peripheral Nerve Conduction Function in STZ-Induced Diabetic Rats (당뇨유발백서에서 피하신경전기자극의 말초신경기능 개선효과)

  • Kim, Yang-Ho;Chang, Mee-Kyung;Shin, Min-Chul
    • The Journal of Korean Physical Therapy
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    • v.18 no.4
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    • pp.19-26
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    • 2006
  • Purpose: This study aimed the effects of percutaneous electric nerve stimulation (PENS) applied to different parts of the streptozotocin-induced diabetic rats on the change of glucose and nerve. Methods: rats (ten weeks old) were selected as the subjects; the normal group was five rats, and the diabetes induction group II, III and IV were five rats, respectively, which were randomly sampled from the twenty-five streptozotocin-administered rats with more than 240d/m of blood sugar. For PENS, electric current with 2 Hz of stimulation frequency and 200μs of pulse duration was applied to the subjects for fifteen minutes a day, six days a week, for three weeks. Calculation of glucose and weight, and nerve conduction test were conducted forty-eight hours and three weeks after streptozotocin administration, respectively. Results: As for change of glucose and weight, the group III with stimulation to the acupoints and the group IV with stimulation to non-acupoints showed significant differences from the control group II (p<0.05). As for MNCV (motor nerve conduction velocity), the group III with stimulation to the acupoints showed significant differences from the group IV with stimulation to non-acupoints and the control group II (p<0.05). Conclusion: PENS had the effects of inhibiting increase of glucose, change of weight and decrease of nerve conductive function between the distal and proximal ends of the peripheral nerve in the STZ-induced diabetic rats.

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A Study of Clinical Research Acupuncture Treatment on Post-stroke Cognitive Disorder (뇌졸중 후 인지장애의 침 치료에 대한 임상적 연구 고찰)

  • Jin, San-long;Yun, Jong-min;Moon, Byung-soon
    • The Journal of Internal Korean Medicine
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    • v.39 no.3
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    • pp.389-404
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    • 2018
  • Objective: The aim of this study was to investigate acupuncture therapy for post-stroke cognitive disorder to suggest the methods of a study about acupuncture therapy. Methods: Several academic databases were used in this study, including National Digital Science Library (NDSL), National Assembly Library of Korea, Korean Traditional Knowledge Portal, Research Information Sharing Service (RISS), Korean studies Information Service System (KISS), Korean Medical Database (KMBASE), Korea Med, Oriental Medicine Advanced Searching Integrated System (OASIS), PubMed, MEDLINE with Full Text, and China National Knowledge Infrastructure (CNKI). Keywords used were "중풍", "뇌졸중", "인지장애", "침", "acupuncture", and "cognitive disorder". Results: Ultimately, 28 papers were investigated. that were mainly published in 2012 and 2016. Of these, More than two-thirds received a score of one or less on the Jadad scale. Acupuncture points such as GV20, GV24, PC6, EX-HN1, SP6, and GV26 were most frequently used. The treatment duration was mostly 30 minutes or less, and the treatment cycle was mostly for four weeks. Dilatational wave was generally used in pulse wave form, and amplitude of electricity was increased until patients were able to endure. G6805 was generally used in electric acupuncture apparatus. According to results of acupuncture treatment, assessments such as the MMSE (Mini Mental State Examination) and the Montreal Cognitive Function Assessment Scale (MoCA) showed statistically significant improvements in 28 studies. Conclusions: Future research is needed to standardize the treatment of acupuncture, and more diversified high quality papers should be published to help clarify the therapeutic effects of acupuncture and the mechanisms of cognitive disorder post-stroke.

Two Types of Voltage-activated Calcium Currents in Goldfish Horizontal Cells

  • Paik, Sun-Sook;Bai, Sun-Ho;Jung, Chang-Sub
    • The Korean Journal of Physiology and Pharmacology
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    • v.9 no.5
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    • pp.269-273
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    • 2005
  • In horizontal cells (HCs) that were freshly dissociated from goldfish retina, two types of voltagedependent calcium currents (ICa) were recorded using a patch-clamping configuration: a transient type current and a sustained type current. The cell was held at -40 mV, and the prepulse step of -90 mV was applied before command pulse between -65 and +55 mV. The transient Ca2+ current was activated by depolarization to around -50 mV from a prepulse voltage of -90 mV lasting at least 400 ms and reached a maximal value near -25 mV. On the other hand, the sustained Ca2+ current was induced by pre-inactivation for less than 10 ms duration. Its activation started near -10 mV and peaked at +20 mV. Co2+ (2 mM) suppressed both of these two components, but nifedipine (20μM), L-type Ca2+ channel antagonist, blocked only the sustained current. Based on the activation voltage and the pharmacologICal specificity, the sustained current appears to be similar to L-type ICa and the transient type to T-type ICa. This study is the first to confirm that transient type ICa together with the sustained one is present in HCs dissociated from goldfish retina.

Effects of disturbance timing on community recovery in an intertidal habitat of a Korean rocky shore

  • Kim, Hyun Hee;Ko, Young Wook;Yang, Kwon Mo;Sung, Gunhee;Kim, Jeong Ha
    • ALGAE
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    • v.32 no.4
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    • pp.325-336
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    • 2017
  • Intertidal community recovery and resilience were investigated with quantitative and qualitative perspectives as a function of disturbance timing. The study was conducted in a lower intertidal rock bed of the southern coast of South Korea. Six replicates of artificial disturbance of a 50cm×50cm area were made by clearing all visible organisms on the rocky substrate in four seasons. Each of the seasonally cleared plots was monitored until the percent cover data reached the control plot level. There was a significant difference among disturbance timing during the recovery process in terms of speed and community components. After disturbances occurred, Ulva pertusa selectively preoccupied empty spaces quickly (in 2-4 months) and strongly (50-90%) in all plots except for the summer plots where non-Ulva species dominated throughout the recovery period. U. pertusa acted as a very important biological variable that determined the quantitative and qualitative recovery capability of a community. The qualitative recovery of communities was rapid in summer plots where U. pertusa did not recruit and the community recovery rate was the lowest in winter plots where U. pertusa was highly recruited with a long duration of distribution. In this study, U. pertusa was a pioneer species while being a dominant species and acted as a clearly negative element in the process of qualitative recovery after disturbance. However, the negative effect of U. pertusa did not occur in summer plots, indicating that disturbance timing should be considered as a parameter in understanding intertidal community resilience in temperate regions with four distinct seasons.