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Sample records for argon plasma coagulator

  1. Endobronchial Electrocautery and Argon Plasma Coagulation: A Practical Approach

    Directory of Open Access Journals (Sweden)

    Alain Tremblay

    2004-01-01

    Full Text Available The present review covers the technical and practical aspects of endobronchial electrocautery, including argon plasma coagulation, which have great potential for widespread use by pulmonologists around the world. The various electrocautery modes, power settings and electrode probes are described in detail, and the authors' clinical and technical approach is demonstrated with a narrative description and brief case presentations. Malignant airway obstruction, hemoptysis, web-like stenosis, stent related granulation tissue and early lung carcinomas are the most common indications for treatment. Advantages of electrocautery, such as low cost, rapid effect, safety and ease of use, are contrasted to other endobronchial therapeutic modalities. Published experience with electrocautery is reviewed.

  2. Argon plasma coagulation for rectal bleeding after prostate brachytherapy

    International Nuclear Information System (INIS)

    Smith, Stephen; Wallner, Kent; Dominitz, Jason A.; Han, Ben; True, Lawrence; Sutlief, Steven; Billingsley, Kevin

    2001-01-01

    Purpose: To better define the efficacy and safety of argon plasma coagulation (APC), specifically for brachytherapy-related proctitis, we reviewed the clinical course of 7 patients treated for persistent rectal bleeding. Approximately 2-10% of prostate cancer patients treated with 125 I or 103 Pd brachytherapy will develop radiation proctitis. The optimum treatment for patients with persistent bleeding is unclear from the paucity of available data. Prior reports lack specific dosimetric information, and patients with widely divergent forms of radiation were grouped together in the analyses. Methods and Materials: Seven patients were treated with APC at the Veterans Affairs Puget Sound Health Care System and the University of Washington from 1997 to 1999 for persistent rectal bleeding due to prostate brachytherapy-related proctitis. Four patients received supplemental external beam radiation, delivered by a four-field technique. A single gastroenterologist at the Veterans Affairs Puget Sound Health Care System treated 6 of the 7 patients. If the degree of proctitis was limited, all sites of active bleeding were coagulated in symptomatic patients. An argon plasma coagulator electrosurgical system was used to administer treatments every 4-8 weeks as needed. The argon gas flow was set at 1.6 L/min, with an electrical power setting of 40-45 W. Results: The rectal V100 (the total rectal volume, including the lumen, receiving the prescription dose or greater) for the 7 patients ranged from 0.13 to 4.61 cc. Rectal bleeding was first noticed 3-18 months after implantation. APC (range 1-3 sessions) was performed 9-22 months after implantation. Five patients had complete resolution of their bleeding, usually within days of completing APC. Two patients had only partial relief from bleeding, but declined additional APC therapy. No patient developed clinically evident progressive rectal wall abnormalities after APC, (post-APC follow-up range 4-13 months). Conclusions: Most

  3. Treatment of tracheal mucoepidermoid carcinoma by argon plasma coagulation during pregnancy.

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    Kesrouani, Assaad; Dabar, Georges; Rahal, Samir; Ghorra, Claude

    2015-05-01

    Mucoepidermoid carcinoma of the tracheobronchial tree is a rare airway tumor (cesarean section. We report the first case to be treated by Argon-Plasma Coagulation (APC) in pregnancy. A 35-year-old Caucasian woman G1P0, at 27 weeks of gestation was admitted to the emergency department because of hemoptysis and severe dyspnea. Bronchoscopy and biopsies diagnosed primary tracheal mucoepidermoid carcinoma. Following an episode of tracheal bleeding, she was intubated. After thorough explanations to the family and obtaining informed consent, therapeutic bronchoscopy, under general anesthesia using a rigid bronchoscope, was performed. The tumor was cored out with the tip of the bronchoscope and removed with an alligator forceps. The tumor bed was coagulated with APC. The obstetrical team was ready to intervene in case of maternal emergency. Immediate follow-up was good, and she left the hospital 4 days later. She delivered at 39 weeks of gestation by cesarean section because of dystocia. Five years later, the patient is doing well without any signs or symptoms of recurrence. Pediatric follow-up is normal. Argon Plasma Coagulation for treatment of mucoepidermoid tracheal carcinoma is feasible during pregnancy. Reporting this case could lead to less aggressive management of mucoepidermoid carcinoma in pregnant patients.

  4. A case of radiation hemorrhagic gastritis successfully treated by endoscopic argon plasma coagulation

    International Nuclear Information System (INIS)

    Furukawa, Koichi; Ho, Nichyau; Kuroda, Ken; Ikarashi, Kentarou; Hata, Koujirou; Tukioka, Satosi

    2003-01-01

    A 72-year-old woman underwent irradiation of 46 Grey in total dose, for lumbago of the advanced pancreatic cancer in August 2000. She was admitted to our hospital due to severe anemia in February 2001 with occasionally positive fecal occult blood. Endoscopy revealed erosive gastric mucosa diffuse in the lower body of the stomach, which resulted from radiation. We applied argon plasma coagulation (APC) in March 2001 and succeeded in hemostasis of the widely spreading radiation hemorrhagic gastritis. The progress of the severe anemia improved without cicatricial stenosis. As the coagulation of the APC is limited in the surface mucosa, APC is an easy and effective treatment for radiation hemorrhagic gastritis. (author)

  5. Effects of argon plasma coagulation on human stomach tissue: An ex vivo study.

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    Gong, Eun Jeong; Ahn, Ji Yong; Jung, Hwoon-Yong; Park, Young Soo; Na, Hee Kyong; Jung, Kee Wook; Kim, Do Hoon; Lee, Jeong Hoon; Choi, Kee Don; Song, Ho June; Lee, Gin Hyug; Kim, Jin-Ho

    2017-05-01

    Argon plasma coagulation (APC) is a safe alternative treatment for gastrointestinal neoplasms and precancerous lesions. However, the extent of thermal damage after APC is difficult to predict. We investigated the effects of APC on human stomach tissue. Argon plasma coagulation was performed on 10 freshly resected human stomachs that were obtained after total gastrectomy. The effects on tissue were compared across power settings (40, 60, and 80 W), durations (5, 10, 15, 20, and 25 s), and between injection (submucosal injection of normal saline) and control (without injection) groups. Success was defined as complete mucosal necrosis without damaging the muscularis propria. Without submucosal injection, the incidence of damaging the muscularis propria increased as the power and duration increased. Tissue damage in the injection group was mostly confined to the submucosa, even when using the high-power setting. In the injection group, ablations at 40 W for 20 s, 60 W for 15 s, and 80 W for 15 or 20 s produced success rates ≥80%. In the control group, ablations at 60 W for 10 s, and 80 W for 5, or 10 s produced success rates ≥80%. The optimal energy levels to achieve complete mucosal and submucosal necrosis without damaging the muscularis propria were 800-1600 and 600-800 J in the injection and control groups, respectively. Application of APC produces good results with a low risk of perforation. © 2016 Journal of Gastroenterology and Hepatology Foundation and John Wiley & Sons Australia, Ltd.

  6. Efficacy of argon plasma coagulation for locoregional relapse after chemoradiotherapy for esophageal cancer

    International Nuclear Information System (INIS)

    Kikuchi, Yoshinori; Domon, Kaoru; Otsuka, Takafumi

    2011-01-01

    Salvage therapy for residual or relapsed esophageal cancer after chemoradiotherapy (CRT) has not yet been established. We retrospectively evaluated relapse-free survival (RFS) after local recurrence following CRT and local control rate in patients who underwent argon plasma coagulation (APC). We reviewed the records of 14 patients who underwent APC after CRT for esophageal cancer at our department between 2001 and 2010 and analyzed overall survival (OS), 5-year survival rate, local control rate after APC and RFS-defined as the period between the end of CRT and the time when an iodine-negative area was found. Median OS and median RFS (mRFS) were 33 months and 6 months, respectively. The 5-year survival rate was 16.2%, and the local control rate after APC was 71.4% (10/14). RFS was significantly longer in the T1 group than in the T2/T3 group (p=0.03); the local control rate after APC did not significantly differ between groups. The high-dose (HD) radiation group had a significantly longer RFS and a tendency toward a higher local control rate after APC than did the standard-dose (SD) radiation group. APC was safe and resulted in a high rate of local control, regardless of T factor. HD radiation was associated with longer RFS and greater efficacy of APC treatment for local recurrence. (author)

  7. Sucralfate or placebo following argon plasma coagulation for chronic radiation proctitis: a randomized double blind trial.

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    Chruscielewska-Kiliszek, M R; Regula, J; Polkowski, M; Rupinski, M; Kraszewska, E; Pachlewski, J; Czaczkowska-Kurek, E; Butruk, E

    2013-01-01

    Chronic radiation proctitis is a long-term complication of radiation therapy for pelvic malignancy. The aim of this study was to compare the efficacy and safety of two treatment regimens, sucralfate or placebo, following argon plasma coagulation (APC) for chronic haemorrhagic radiation proctitis. A single-centre, randomized, placebo-controlled, double-blind study was performed on patients with haemorrhagic chronic radiation proctitis after irradiation for prostate, uterine, cervical, rectal or vaginal cancer. All patients received APC, and were then randomized to oral sucralfate (6 g twice a day) or placebo treatment for 4 weeks. APC was repeated every 8 weeks if necessary after the first session. Patients were graded clinically and endoscopically according to the Chutkan and Gilinski scales before and at 8 and 16 weeks after initial APC treatment (1.5-2 l/min, 25-40 W) and after 52 weeks (clinical only). Of 122 patients, 117 completed the entire protocol, with 57/60 in the sucralfate group and 60/62 in the placebo group. At baseline there were no significant differences between the sucralfate and placebo groups. At 1 year, a significant improvement in the clinical scale in both groups occurred compared with baseline. After 16 weeks, the median overall clinical severity scores fell from 4 to 2 points and the median bleeding score from 2 to 0 in both groups. APC is safe and effective for the management of chronic radiation proctitis. Additional sucralfate treatment did not influence the clinical or endoscopic outcome. © 2012 The Authors. Colorectal Disease © 2012 The Association of Coloproctology of Great Britain and Ireland.

  8. A refractory case of radiation proctitis. Effectiveness of argon plasma coagulation therapy and the rectal stenosis after therapy

    International Nuclear Information System (INIS)

    Oyama, Katsunobu; Morita, Akihiko; Terada, Itsuro

    2006-01-01

    A 75-years-old man received external radiation with a cumulative dose of 60 Gy for prostatic cancer. Severe hematochezia occurred approximately 16 months after irradiation. A extensive and circumferential telangiectatic lesion in the lower segment of the rectum was detected, then he was diagnosed as having radiation proctitis. Pharmacotherapy was employed at first, but the bleeding was uncontrollable. Colostomy was performed, but the bleeding could not be controlled. Argon plasma coagulation therapy (APC) was applied, and the bleeding ceased after first session of APC. But the severe rectal stricture appeared three months after APC. APC is effective treatment for refractory radiation proctitis, but the rectal stenosis was occurred three months after APC. (author)

  9. Argon Plasma Coagulation Therapy Versus Topical Formalin for Intractable Rectal Bleeding and Anorectal Dysfunction After Radiation Therapy for Prostate Carcinoma

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    Yeoh, Eric, E-mail: eric.yeoh@health.sa.gov.au [Department of Radiation Oncology, Royal Adelaide Hospital, Adelaide (Australia); School of Medicine, University of Adelaide, Adelaide (Australia); Tam, William; Schoeman, Mark [School of Medicine, University of Adelaide, Adelaide (Australia); Department of Gastroenterology, Royal Adelaide Hospital, Adelaide (Australia); Moore, James; Thomas, Michelle [School of Medicine, University of Adelaide, Adelaide (Australia); Department of Colorectal Surgery, Royal Adelaide Hospital, Adelaide (Australia); Botten, Rochelle; Di Matteo, Addolorata [Department of Radiation Oncology, Royal Adelaide Hospital, Adelaide (Australia)

    2013-12-01

    Purpose: To evaluate and compare the effect of argon plasma coagulation (APC) and topical formalin for intractable rectal bleeding and anorectal dysfunction associated with chronic radiation proctitis. Methods and Materials: Thirty men (median age, 72 years; range, 49-87 years) with intractable rectal bleeding (defined as ≥1× per week and/or requiring blood transfusions) after radiation therapy for prostate carcinoma were randomized to treatment with APC (n=17) or topical formalin (n=13). Each patient underwent evaluations of (1) anorectal symptoms (validated questionnaires, including modified Late Effects in Normal Tissues–Subjective, Objective, Management, and Analytic and visual analogue scales for rectal bleeding); (2) anorectal motor and sensory function (manometry and graded rectal balloon distension); and (3) anal sphincteric morphology (endoanal ultrasound) before and after the treatment endpoint (defined as reduction in rectal bleeding to 1× per month or better, reduction in visual analogue scales to ≤25 mm, and no longer needing blood transfusions). Results: The treatment endpoint was achieved in 94% of the APC group and 100% of the topical formalin group after a median (range) of 2 (1-5) sessions of either treatment. After a follow-up duration of 111 (29-170) months, only 1 patient in each group needed further treatment. Reductions in rectal compliance and volumes of sensory perception occurred after APC, but no effect on anorectal symptoms other than rectal bleeding was observed. There were no differences between APC and topical formalin for anorectal symptoms and function, nor for anal sphincteric morphology. Conclusions: Argon plasma coagulation and topical formalin had comparable efficacy in the durable control of rectal bleeding associated with chronic radiation proctitis but had no beneficial effect on anorectal dysfunction.

  10. Argon Plasma Coagulation Therapy Versus Topical Formalin for Intractable Rectal Bleeding and Anorectal Dysfunction After Radiation Therapy for Prostate Carcinoma

    International Nuclear Information System (INIS)

    Yeoh, Eric; Tam, William; Schoeman, Mark; Moore, James; Thomas, Michelle; Botten, Rochelle; Di Matteo, Addolorata

    2013-01-01

    Purpose: To evaluate and compare the effect of argon plasma coagulation (APC) and topical formalin for intractable rectal bleeding and anorectal dysfunction associated with chronic radiation proctitis. Methods and Materials: Thirty men (median age, 72 years; range, 49-87 years) with intractable rectal bleeding (defined as ≥1× per week and/or requiring blood transfusions) after radiation therapy for prostate carcinoma were randomized to treatment with APC (n=17) or topical formalin (n=13). Each patient underwent evaluations of (1) anorectal symptoms (validated questionnaires, including modified Late Effects in Normal Tissues–Subjective, Objective, Management, and Analytic and visual analogue scales for rectal bleeding); (2) anorectal motor and sensory function (manometry and graded rectal balloon distension); and (3) anal sphincteric morphology (endoanal ultrasound) before and after the treatment endpoint (defined as reduction in rectal bleeding to 1× per month or better, reduction in visual analogue scales to ≤25 mm, and no longer needing blood transfusions). Results: The treatment endpoint was achieved in 94% of the APC group and 100% of the topical formalin group after a median (range) of 2 (1-5) sessions of either treatment. After a follow-up duration of 111 (29-170) months, only 1 patient in each group needed further treatment. Reductions in rectal compliance and volumes of sensory perception occurred after APC, but no effect on anorectal symptoms other than rectal bleeding was observed. There were no differences between APC and topical formalin for anorectal symptoms and function, nor for anal sphincteric morphology. Conclusions: Argon plasma coagulation and topical formalin had comparable efficacy in the durable control of rectal bleeding associated with chronic radiation proctitis but had no beneficial effect on anorectal dysfunction

  11. The role of argon plasma coagulation in the management of Barrett's esophagus: a single-center experience

    Directory of Open Access Journals (Sweden)

    Gad YZ

    2011-04-01

    Full Text Available Yahia Z Gad1, Adel A Zeid21Associate Professor of Internal Medicine, Mansoura Specialized Medical Hospital, Mansoura University, Mansoura, Egypt; 2Consultant Surgeon, Al Nil Hospital, Mansaura, EgyptBackground/aim: Patients with Barrett's esophagus (BE are 30 times more likely to develop esophageal adenocarcinoma (EAC than the general population. Data regarding the use of argon plasma coagulation (APC for treatment of patients with BE in Egypt are still limited. This article discusses the efficacy and safety of APC as a thermoablative modality in Egyptian patients with BE.Materials and methods: A total of 73 referred eligible patients with a confirmed endoscopic and histopathologic diagnosis of BE were enrolled in this study and subjected to thermoablation by high-power (hp-APC equipment at a 60 W setting until complete ablation or a maximum of five sessions and were followed up clinically and endoscopically at 3-month intervals. Computer-generated randomization allocated patients into APC-treated and control groups (n = 75, all of whom were treated with a proton pump inhibitor.Results: Minor and major complications occurred in 8 of 73 (10.95% and 1 of 73 (1.36% patients, respectively. Macroscopic ablation was achieved after one session in 37 of 73 (50.63% patients, and complete histologic ablation was confirmed after 167 sessions in 69 of 73 (94.52% patients. At 1-year follow-up, no relapses of BE or progression to EAC were observed.Conclusion: hp-APC at a medium-energy setting of 60 W in an acid-reduced environment can ablate BE effectively and safely with promising initial results.Keywords: Barrett's esophagus, argon plasma coagulation

  12. [Argon plasma coagulation combined with cryotherapy via bronchoscopy for the treatment of one child with severe post-intubation tracheal stenosis and literature review].

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    Zhou, Kuo; Liang, Jun; Cui, Ai-hua; Fu, Ai-xia; Yang, Qiao-zhi

    2013-10-01

    To observe the short term effect of argon plasma coagulation (APC) combined with cryotherapy via bronchoscopy for treatment of severe post-intubation tracheal stenosis in a child. A 3-year old boy was admitted for cephalothorax abdominal compound trauma and dyspnea, who had severe post-incubation tracheal stenosis. The agreement about the operation risk was signed by the parents. Endotracheal APC procedure was performed with a bronchoscope under general anesthesia. The APC probe was put into the working channel of the bronchoscope. The stenotic lesion was endoscopically visualized and then coagulated by argon plasma. Such coagulation was carried out several times at the stenotic site until it gradually became dilated. The devitalized tissue was mechanically removed with grasping forceps. Thereafter, bronchoscopic cryosurgery was repeatedly performed at the stenotic site. Clinical symptoms, signs and bronchoscopic manifestations were observed right after operation, after 1 day, 10 days, 1 month and 6 months separately. Tracheal tissue hyperplasia and cyanosis disappeared, laryngeal stridor and dyspnea improved obviously right after the operation. General condition of the patient was well, there was no laryngeal stridor and dyspnea 10 days after operation. The mucosa of the surgical site was smooth and no tracheostenosis was seen under bronchoscope at 1 month and 6 months after the operation. Argon plasma coagulation combined with cryotherapy via bronchoscope is an effective method to treat tracheal stenosis of children, which needs further exploration for the application.

  13. Electrocautery Snare Is Combined with CO2 Cryosurgery and Argon Plasma Coagulation for the Treatment of Airway Tumors and Granulomas

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    Hongwu WANG

    2013-06-01

    Full Text Available Background and objective To observe the clinical effects and safety of endobronchial electrocautery snare combined with CO2 cryosurgery for the treatment of tracheobronchial obstructive lesions. Materials and methods Seventy-seven patients with airway tumor or granuloma were retrospectively reviewed, including 70 malignant airway obstruction and 7 benign airway lesions, for the treatment of endobronchial electrocautery snare plus CO2 cryosurgery and argon plasma coagulation (APC. Results Eighty-five endobronchial snares were performed in 77 cases. 42.9% of the obstructive lesions were located in right bronchial orifice, 38.3% in main trachea 21.4% in left bronchial orifice. 89.7% of the malignant tumor was mixed type of lesions (endobronchial plus bronchial or external bronchial, only 10.3% was endobronchial. Obstructive stenosis was significant relieved after snare (80% before vs 20% after, P<0.01 in all patients. Karnofsky Performance Status (KPS and shortbreath score were obviously improved after snare. There was no severe complications related to the procedures. Conclusion Endobronchial electrocautery snare is an effective and safe approach for tracheobronchial obstructions with few complications.

  14. A Case of Recurrent Respiratory Papillomatosis Successfully Removed Via Endoscopic Argon Plasma Coagulation (APC) With No Evidence of Recurrence.

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    Wong, J L; Tie, S T; Lee, J; Kannan, S K; Rashid Ali, M R; Ibrahim, A; Abdul Rahman, J A

    2014-08-01

    Recurrent respiratory papillomatosis (RRP) is a benign disease caused by the human papilloma virus (HPV), characterized by the formation of recurrent, epithelial neoplastic lesions in the airways. While benign, they can cause significant airway obstruction in some cases. Difficulties in treatment arise from the recurrent nature of the lesions despite repeated procedures. Other known procedures that result in deep tissue damage also cause unacceptable collateral damage to the underlying airway mucosa. We describe a case of recurrent papillomatosis that was successfully treated with argon plasma coagulation ( APC) when laser and electrocautery ablation had failed in the past. After the papillomatasis was treated with APC, there is no recurrence on repeat scope at 4 months and 9 months after the initial procedure. The procedure was done as a day case and there is no complication from the procedure. The property of the APC that allows it to cause only superficial thermal damage to the tissue makes it a suitable adjunct therapy to the treatment of papillomas, which are usually superficial lesions.

  15. Argon plasma coagulation for a patient with locoregional failure after definitive chemoradiotherapy for esophageal carcinoma. A case report

    International Nuclear Information System (INIS)

    Nomura, Tsutomu; Miyashita, Masao; Makino, Hiroshi; Okawa, Keiichi; Katsuta, Miwako; Tajiri, Takashi

    2008-01-01

    Patients who undergo definitive chemoradiotherapy (CRT) face a risk of residual resistant disease or disease recurrence at the primary site; therefore, salvage treatment may be required. An optimum strategy to minimize these risks clearly needs to be established. Argon plasma coagulation (APC) is a safe and convenient procedure now applied widely for therapeutic endoscopy. In this report we describe the successful use of APC over 6 years for the treatment of recurrent esophageal cancer after CRT. A 61-year-old Japanese man underwent CRT for a thoracic esophageal cancer. Pathological examination before CRT revealed a well-differentiated squamous cell carcinoma. Locoregional failure was observed 2 years after CRT, and an initial APC treatment was performed. The patient has now undergone APC ablation 7 times with no postoperative complications. No metastasis to lymph nodes or to other organs has been detected during the last 6 years. The usefulness of APC as a salvage treatment for locoregional failure after definitive CRT has not been established. In our experience, salvage APC is the best treatment option for some patients. (author)

  16. Argon Plasma Coagulation Combined with Covered Stent Placement for Management of Tracheobronchial Stenoses/occlusions as well as Esophagorespiratory Fistulas

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    Hongwu WANG

    2010-09-01

    Full Text Available Background and objective It is a complex problem and difficult treatment for tracheobronchial stenoses/occlusions involving in carina. The aim of this study is to investigate the feasibility and efficiency of argon plasma coagulation (APC and bifurcated covered Z-type stents (CZTS placement for the treatment of tracheobronchus stenoses and esophagorespiratory fistula (ERF. Methods Thirty-two cases with airway disorders were retrospectively reviewed for the treatment of APC and CZTS placement. Under the bronchoscopic guidance, APC was first given in patients with airway stenoses, then CZTS was placed under the fluoroscopic and flexible bronchoscopic guidance either with airway stenoses or ERF. Results APC was first given in 19 patients with airway stenoses. Airway structures were significantly improved after APC procedure (57.4%-72.1% before APC vs 12.8%-25.8% after APC. Thirty-two CZTS were technically successfully placed in 30 out of 32 cases involving in carinal bifurcation. After APC and stent placement, short breath index was significantly reduced and karnofsky physical score (KPS increased obviously. The endobronchial defects were successfully palliated with bifurcated CZTS placed under fluoroscopy and flexible bronchoscopy in 12 out of 13 patients with ERFs. There is no bleeding introprocedure. Mucous retention was very common in all types of the stents less than 2 weeks after stenting, which required debridement by bronchoscopy and could be prevented by normal saline solution nebulizations. Granuloma developed at the ends of stents after 1 month of stenting which all of them were treated successfully with APC and CO2 cryosurgery. Conclusion Utilization of APC and retrieval bifurcated CZTS placement is a simple and safe protocol for the management of airway complex stenoses involving the tracheal carina and ERF.

  17. Comparison of argon plasma coagulation in management of upper gastrointestinal angiodysplasia and gastric antral vascular ectasia hemorrhage.

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    Chiu, Yi-Chun; Lu, Lung-Sheng; Wu, Keng-Liang; Tam, William; Hu, Ming-Luen; Tai, Wei-Chen; Chiu, King-Wah; Chuah, Seng-Kee

    2012-06-09

    Vascular ectasias, including gastric antral vascular ectasia (GAVE) and angiodysplasia, are increasingly recognized as important sources of gastrointestinal bleeding. This study investigated and compared the efficacies and outcomes of treatment of upper gastrointestinal (UGI) angiodysplasia and GAVE hemorrhage by endoscopic argon plasma coagulation (APC). From January 2006 to December 2009, 46 patients diagnosed with upper GI bleeding caused by angiodysplasia or GAVE at a tertiary hospital were recruited into this study. They included 26 males and 20 females with an average age of 65.6 years (range, 45-90 years). All patients underwent APC for hemostasis during an endoscopic procedure. Parameters such as underlying co-morbidities, number of endoscopic treatment sessions, recurrent bleeding, and clinical outcomes during follow-up were analyzed. The 46 patients with UGI vascular ectasia hemorrhage included 27 patients with angiodysplasia and 19 with GAVE. The patients with angiodysplasia were older than those with GAVE (71.6 ± 10.2 years versus 61.8 ± 11.9 years, P = 0.005). More GAVE patients than angiodysplasia patients had co-existing liver cirrhosis (63.2% versus 25.9%, P = 0.012). The patients with GAVE had a higher rate of recurrent bleeding (78.9% versus 7.4%, P bleeding. Further multivariate analysis revealed that GAVE was the only independent risk factor for recurrent bleeding after APC treatment (OR = 0.027, P bleeding. The efficacy of APC treatment is greater for angiodysplasia than for vascular ectasia bleeding. GAVE patients have a higher recurrent bleeding rate and may require multiple treatment sessions for sustained hemostasis.

  18. Post-bariatric surgery weight regain: evaluation of nutritional profile of candidate patients for endoscopic argon plasma coagulation.

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    Cambi, Maria Paula Carlini; Marchesini, Simone Dallegrave; Baretta, Giorgio Alfredo Pedroso

    2015-01-01

    Bariatric surgery is effective treatment for weight loss, but demand continuous nutritional care and physical activity. They regain weight happens with inadequate diets, physical inactivity and high alcohol consumption. To investigate in patients undergoing Roux-Y-of gastroplasty weight regain, nutritional deficiencies, candidates for the treatment with endoscopic argon plasma, the diameter of the gastrojejunostomy and the size of the gastric pouch at the time of treatment with plasma. A prospective 59 patients non-randomized study with no control group undergoing gastroplasty with recurrence of weight and candidates for the endoscopic procedure of argon plasma was realized. The surgical evaluation consisted of investigation of complications in the digestive system and verification of the increased diameter of the gastrojejunostomy. Nutritional evaluation was based on body mass index at the time of operation, in the minimum BMI achieved after and in which BMI was when making the procedure with plasma. The laboratory tests included hemoglobin, erythrocyte volume, ferritin, vitamin D, B12, iron, calcium, zinc and serum albumin. Clinical analysis was based on scheduled follow-up. Of the 59 selected, five were men and 51 women; were included 49 people (four men and 44 women) with all the complete data. The exclusion was due to the lack of some of the laboratory tests. Of this total 19 patients (38.7%) had a restrictive ring, while 30 (61.2%) did not. Iron deficiency anemia was common; 30 patients (61.2%) were below 30 with ferritin (unit); 35 (71.4%) with vitamin B12 were below 300 pg/ml; vitamin D3 deficiency occurred in more than 90%; there were no cases of deficiency of protein, calcium and zinc; glucose levels were above 99 mg/dl in three patients (6.12%). Clinically all had complaints of labile memory, irritability and poor concentration. All reported that they stopped treatment with the multidisciplinary team in the first year after the operation. The profile of

  19. Is argon plasma coagulation an effective and safe treatment option for patients with chronic radiation proctitis after high doses of radiotherapy?

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    Eduardo Hortelano

    grade 2 rectal incontinence, respectively. Conclusions: The argon plasma coagulation is an effective and safe management option in patients with medically refractory rectal bleeding after high doses of radiation for prostate cancer.

  20. Watermelon stomach: clinical aspects and treatment with argon plasma coagulation Ectasia vascular do antro gástrico ("watermelon stomach": aspectos clínicos e tratamento com coagulação com plasma de argônio

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    Dalton M. Chaves

    2006-09-01

    Full Text Available BACKGROUND: Gastric antral vascular ectasia is a disorder whose pathogenetic mechanism is unknown. The endoscopic treatment with argon plasma coagulation has been considered one of the best endoscopic therapeutic options. AIM: To analyze the endoscopic and clinical features of gastric antral vascular ectasia and its response to the argon plasma coagulation treatment. PATIENTS AND METHODS: Eighteen patients were studied and classified into two groups: group 1 - whose endoscopic aspect was striped (watermelon or of the diffuse confluent type; group 2 - diffuse spotty nonconfluent endoscopic aspect. RESULTS: Group 1 with eight patients, all having autoimmune antibodies, but one, whose antibodies were not searched for. Three were cirrhotic and three had hypothyroidism. All had gastric mucosa atrophy. In group 2, with 10 patients, all had non-immune liver disease, with platelet levels below 90.000. Ten patients were submitted to argon plasma coagulation treatment, with 2 to 36 months of follow-up. Lesions recurred in all patients who remained in the follow-up program and one did not respond to treatment for acute bleeding control. CONCLUSION: There seem to be two distinct groups of patients with gastric antral vascular ectasia: one related to immunologic disorders and other to non-immune chronic liver disease and low platelets. The endoscopic treatment using argon plasma coagulation had a high recurrence in the long-term evaluation.RACIONAL: "Watermelon stomach" ou ectasia vascular do antro gástrico é uma doença de etiopatogenia desconhecida. O tratamento endoscópico através da coagulação com plasma de argônio é considerado uma das melhores opções terapêuticas. OBJETIVO: Analisar os aspectos clínicos e endoscópicos da ectasia vascular do antro gástrico e a resposta ao tratamento com coagulação com plasma de argônio. PACIENTES E MÉTODOS: Dezoito pacientes foram estudados e classificados em dois grupos: grupo I - oito pacientes que

  1. Dynamics of imploding argon plasmas

    International Nuclear Information System (INIS)

    Clark, W.; Richardson, R.; Brannon, J.; Wilkinson, M.; Katzenstein, J.

    1982-01-01

    The BLACKJACK 5 pulse generator has been used to implode annular argon plasmas to form dense Z pinches. Visible streak photography, framing photography, and laser shadowgraphy were used to observe the radial position and velocity of the plasmas as they imploded. The measured position and velocity of the imploding plasmas have been compared with the results of calculations based on a one-dimensional snowplow model. Good agreement is obtained between the snowplow calculations and the optical measurements. Empirically determined optimum implosion parameters are also found to agree with those predicted by the model

  2. Electrical and spectroscopic characterization of a surgical argon plasma discharge

    International Nuclear Information System (INIS)

    Keller, Sandra; Neugebauer, Alexander; Bibinov, Nikita; Awakowicz, Peter

    2013-01-01

    For electrosurgical procedures, the argon plasma coagulation (APC) discharge is a well-established atmospheric-pressure plasma tool for thermal haemostasis and devitalization of biological tissue. To characterize this plasma source, voltage-current measurements, microphotography, optical emission spectroscopy and numerical simulation are applied. Two discharge modes are established during the operation of the APC plasma source. A short transient spark discharge is ignited within the positive half period of the applied high voltage after a streamer channel connects the APC probe and the counter-electrode. During the second phase, which continues under negative high voltage, a glow discharge is stabilized in the plasma channel.

  3. Continuum radiation of argon plasma

    International Nuclear Information System (INIS)

    D'Yachkov, L.G.

    1995-01-01

    A simple completely analytical method of the calculation of radiative continuum of plasmas is derived and an analysis of experimental data on continuum radiation of argon plasma is made. The method is based on the semiclassical quantum defect theory. To calculate radial matrix elements of dipole transitions the asymptotic expansion in powers of E c /ω 2/3 , with an accuracy to the linear term, where E, is the arithmetic mean of the initial and final energies of the transition, is used. This expansion has the same form for free-free, free-bound and bound-bound transitions. If the quantum defects are also approximated by a linear function of energy, the integration over the electron energy (the Maxwell-Boltzmann distribution is assumed) can be performed in analytical form. For Rydberg states the sum of photoionization continua can be replaced by an integral. We have calculated the absorption coefficient pf argon plasma. The photoionization cross section is calculated for all the states of 4s, 5s, 6s, 4p, 5p, 3d, 4d, 4s', 5s', 6s', 4p', 5p', 3d' and 4d' configurations taking into account P-coupling and multiplet splitting (56 states). Other excited states are allowed for by the integral formula together with free-free transitions

  4. Efficacy and safety of argon plasma coagulation for the treatment of hemorrhagic radiation proctitis Eficacia y seguridad de la electrocoagulación con plasma de argón en el tratamiento del sangrado rectal secundario a proctitis por radioterapia

    Directory of Open Access Journals (Sweden)

    C. de la Serna Higuera

    2004-11-01

    Full Text Available Objective: to evaluate the efficacy, safety and medium-/long-term clinical course of patients undergoing endoscopic treatment with argon plasma coagulation for hemorrhagic radiation proctopathy. Design: descriptive, retrospective study with medium- and long-term follow-up. Patients, material and methods: ten patients were treated with argon plasma coagulation for hemorrhagic radiation proctopathy between July 1998 and February 2003. Inclusion criteria were: evidence of chronic rectal bleeding, consistent endoscopic findings, and absence of any other cause of hematochezia after a comprehensive ano-rectal examination and complete colonoscopy. The equipment used was a standard colonoscope, an argon delivery unit, an argon plasma coagulation probe 1.5 mm in internal diameter, and a high-frequency electrosurgical generator. Consecutive treatment sessions were programmed whenever it was considered necessary until all mucosal lesions had been treated. Clinical and evolutive follow-up was performed with a focus on tolerance, efficacy, and potential argon plasma coagulation-related complications. Data were updated by personal or telephonic interview. Results: in all patients, chronic rectal bleeding stopped after the last treatment session. The mean number of treatment sessions to stop symptoms was 1.7. Mean follow-up was 31.1 months. All sessions were well tolerated, similarly to standard rectoscopy. In one case a recurrence of rectal bleeding was observed four months later, which required two repeat sessions. Four patients were anemic at inclusion. Three of them reported a resolved anemia at the end of the study. No delayed argon plasma coagulation-related complications such us ulcers or strictures were seen. Conclusions: argon plasma coagulation appears to be a useful, effective and safe treatment for rectal bleeding resulting from chronic radiation proctitis when compared to standard medical and endoscopic treatments. These successful outcomes seem

  5. Gasdynamic structure of free argon plasma jet

    International Nuclear Information System (INIS)

    Dunder, J.

    1973-01-01

    The paper deals with the experimental results of research conducted on the argon plasma jet. Special miniaturized water cooled Pitot probes (1.45 and 2.5 mm. dia.) were used for the measurement of the total head. The results correlate the length of the arc chamber and other main parameters of the plasma generator with the length of the core and maximum values of the total pressure and velocity in the core of the jet. For the plasma generator used for the experiments the axial and radial distributions of the pressure as well as the generalized volt-ampere dependence were obtained. (author)

  6. Contact activation of blood-plasma coagulation

    Science.gov (United States)

    Golas, Avantika

    Surface engineering of biomaterials with improved hemocompatibility is an imperative, given the widespread global need for cardiovascular devices. Research summarized in this dissertation focuses on contact activation of FXII in buffer and blood plasma frequently referred to as autoactivation. The extant theory of contact activation imparts FXII autoactivation ability to negatively charged, hydrophilic surfaces. According to this theory, contact activation of plasma involves assembly of proteins comprising an "activation complex" on activating surfaces mediated by specific chemical interactions between complex proteins and the surface. This work has made key discoveries that significantly improve our core understanding of contact activation and unravel the existing paradigm of plasma coagulation. It is shown herein that contact activation of blood factor XII (FXII, Hageman factor) in neat-buffer solution exhibits a parabolic profile when scaled as a function of silanized-glass-particle activator surface energy (measured as advancing water adhesion tension t°a=g° Iv costheta in dyne/cm, where g°Iv is water interfacial tension in dyne/cm and theta is the advancing contact angle). Nearly equal activation is observed at the extremes of activator water-wetting properties --36 moderated by adsorption of plasma proteins unrelated to coagulation through an "adsorption-dilution" effect that blocks FXII contact with hydrophobic activator surfaces. The adsorption-dilution effect explains the apparent specificity for hydrophilic activators pursued by earlier investigators. Finally a comparison of FXII autoactivation in buffer, serum, protein cocktail, and plasma solutions is shown herein. Activation of blood plasma coagulation in vitro by contact with material surfaces is demonstrably dependent on plasma-volume-to-activator-surface-area ratio. However, activation of factor XII dissolved in buffer, protein cocktail, heat-denatured serum, and FXI deficient plasma does not

  7. Development of a low-cost inductively coupled argon plasma

    International Nuclear Information System (INIS)

    Ripson, P.A.M.

    1983-01-01

    The aim of this investigation is to drastically reduce running costs of an inductively coupled plasma. This is done by reducing the argon consumption from 20 l/min to about 1 l/min. First, a sample introduction system operating on 0.1 l/min of carrier argon is described. This system ensures a high ratio of plasma argon and carrier argon even at the low total argon consumptions intended. Next, the developed low consumption plasma is presented. In the proposed design, air is blown perpendicularly against the outside of the torch. A different coil has been developed to make air-cooling efficient. Preliminary data on coupling efficiency for the air-cooled plasma are presented. A similarly low argon consumption has been achieved with water as an external coolant medium. It is concluded that a cheaper alternative to the current ICP has become available. (Auth.)

  8. The feed gas composition determines the degree of physical plasma-induced platelet activation for blood coagulation

    Science.gov (United States)

    Bekeschus, Sander; Brüggemeier, Janik; Hackbarth, Christine; Weltmann, Klaus-Dieter; von Woedtke, Thomas; Partecke, Lars-Ivo; van der Linde, Julia

    2018-03-01

    Cold atmospheric (physical) plasma has long been suggested to be a useful tool for blood coagulation. However, the clinical applicability of this approach has not been addressed sufficiently. We have previously demonstrated the ability of a clinically accepted atmospheric pressure argon plasma jet (kINPen® MED) to coagulate liver incisions in mice with similar performance compared to the gold standard electrocauterization. We could show that plasma-mediated blood coagulation was dependent on platelet activation. In the present work, we extended on this by investigating kINPen®-mediated platelet activation in anticoagulated human donor blood ex vivo. With focus on establishing high-throughput, multi-parametric platelet activation assays and performing argon feed gas parameter studies we achieved the following results: (i) plasma activated platelets in heparinized but not in EDTA-anticoagulated blood; (ii) plasma decreased total platelet counts but increased numbers of microparticles; (iii) plasma elevated the expression of several surface activation markers on platelets (CD62P, CD63, CD69, and CD41/61); (iv) in platelet activation, wet and dry argon plasma outperformed feed gas admixtures with oxygen and/or nitrogen; (v) plasma-mediated platelet activation was accompanied by platelet aggregation. Platelet aggregation is a necessary requirement for blood clot formation. These findings are important to further elucidate molecular details and clinical feasibility of cold physical plasma-mediated blood coagulation.

  9. Characterization of DC argon plasma jet at atmospheric pressure

    International Nuclear Information System (INIS)

    Yan Jianhua; Ma Zengyi; Pan Xinchao; Cen Kefa; Bruno, C

    2006-01-01

    An original DC double anode plasma torch operating with argon at atmospheric pressure which provides a long time and highly stable plasma jet is analyzed through its electrical and optical signals. Effects of gas flow rate and current intensity on the arc dynamics behaviour are studied using standard diagnostic tools such as FFT and correlation function. An increasing current-voltage characteristic is reported for different argon flow rates. It is noted that the takeover mode is characteristic for argon plasma jet and arc fluctuations in our case are mainly induced by the undulation of torch power supply. Furthermore, the excitation temperatures and electron densities of the plasma jet inside and outside the arc chamber have been determined by means of optical emission spectroscopy (OES). The criteria for the existence of local thermodynamic equilibrium (LTE) in plasma is then discussed. The results show that argon plasma jet at atmospheric pressure under our experimental conditions is close to LTE. (authors)

  10. Formation of carbon nanostructures using acetylene, argon-acetylene and argon-hydrogen-acetylene plasmas

    International Nuclear Information System (INIS)

    Marcinauskas, L.; Grigonis, A.; Minialga, V.; Marcinauskas, L.; Valincius, V.

    2013-01-01

    The films prepared in argon-acetylene plasma are attributed to graphite-like carbon films. Addition of the hydrogen decreases growth rate and the surface roughness of the films and lead to the formation of nanocrystalline graphite. The carbon nanotubes were formed at low (≤ 450°C; p = 40 Pa) temperature in pure acetylene plasma. (authors)

  11. Studies on EOS of shock-generated argon plasmas

    International Nuclear Information System (INIS)

    Wang Fanhou; Jing Fuqian

    2001-01-01

    The equation of state for argon plasma, covering the thermodynamic states of 10000-30000 K in temperature and 0.0133-0.166 GPa in pressure, is computed using the Saha model and Debye-Huckel correction. Comparisons of the measured EOS with the calculated ones demonstrate the Saha model and Debye-Huckel correction can be used to well describe the essential behavior of argon plasma under the thermodynamic condition above-mentioned

  12. Plasma flow in a pressure pulsed argon cascade arc

    NARCIS (Netherlands)

    de Haas, J.C.M.; Bol, L.; Kroesen, G.M.W.; Timmermans, C.J.; Timmermans, C.J.

    1985-01-01

    Flowing thermal plasmas are frequently used e . g. in welding, cutting, plasma deposition and testing materials at high temperatures . In most of the applications the geometry is complex . In the cascade arc the argon plasma flows through a straight circular channel with a constant area. The study

  13. Turbulence and transport in a magnetized argon plasma

    International Nuclear Information System (INIS)

    Pots, B.F.M.

    1979-01-01

    An experimental study on turbulence and transport in the highly ionized argon plasma of a hollow cathode discharge is described. In order to determine the plasma parameters three standard diagnostics have been used, whilst two diagnostics have been developed to study the plasma turbulence. (Auth.)

  14. Electrical Measurements on a Moving Argon Plasma

    Energy Technology Data Exchange (ETDEWEB)

    Abbas, A. A.M.; Howatson, A. M. [Oxford University (United Kingdom)

    1966-10-15

    Experimental current-voltage characteristic curves were obtained for a moving argon plasma at two stations in an electrically-driven 5 cm shock tube. The standard energy was 1 kj and the base pressure 10 torr, giving a shock of about Mach 4. The measurements were made on the highly-ionized driver gas which followed the shock at speeds between 800 and 1100 m/sec. Two types of electrode were used. One comprised circular solid electrodes of aluminium, molybdenum or stainless steel so machined as to be quite flush with the tube wall; the other comprised filaments of tungsten wire which were immersed in the free stream and could be used cold or heated for thermionic emission. Characteristics were obtained both for applied voltages and for MHD-generated voltages; for the latter a magnetic field of good uniformity up to 0.9 Wb/m{sup 2} was used. The results were always markedly dependent on the surface condition of the electrodes. For consistent results the flush electrodes had to be cleaned carefully by hand after every third discharge, while the filament electrodes were thermionically cleaned before every discharge. In general the cold electrode characteristics for applied voltage showed three distinct regions: a current increase such as would be expected from a double probe; a saturation region; and a linear increase, in order of increasing voltage. For the flush electrodes another apparent saturation was found before, finally, the transition to an arc-type discharge. The first saturation current for flush electrodes corresponded to a random ion current much less than that estimated to exist away from the tube walls, as is expected from a consideration of diffusion through a boundary layer. The value of the current varied somewhat with the electrode material. For the cold filaments, the saturation current density was of the same order as for the flush electrodes. From the linear region of the curves, an effective plasma conductivity was obtained. For comparison, the

  15. Argon plasma coagulation and hyperbaric oxygen therapy in chronic radiation proctopathy, effectiveness and impact on tissue toxicity Argón plasma y oxígeno hiperbárico para el control de la rectorragia crónica secundaria a la proctopatía por radiación

    Directory of Open Access Journals (Sweden)

    Julio César Álvaro-Villegas

    2011-11-01

    Full Text Available Background: chronic radiation proctopathy (CRP is associated with recurrent rectal bleeding and transfusional requirements. Argon plasma coagulation (APC and hyperbaric oxygen therapy (HOT have been shown to be effective in the control of CRP. No prospective comparisons have been reported between these treatments. Aim: the aim was to evaluate the effectiveness, safety and impact on tissue toxicity of APC compared to HOT in patients with CRP. Material and methods: a prospective study for evaluating treatment response was conducted. Patients with cervical cancer and CRP with rectal bleeding were recruited. They had not received previous treatment. Collected data included: demographics, previous radiation dosage, duration and severity of rectal bleeding. Hemoglobin, transfusional requirements, and tissue toxicity (SOMA LENT questionnaire at baseline and at 1, 2, and 3 months follow up were recorded. Results: thirty-one patients were included, 14 in the APC group and 17 in the HOT group. No response was noted in 13 and 18% of patients in the APC and HOT group respectively (p = NS. At the 1 and 2 months follow-up, the APC group showed a significantly better response in terms of transfusional requirements (0.6 vs. 3.4 and 0.7 vs. 2.5 and tissue toxicity score (5.3 vs. 8.6 and 3.8 vs. 7.248. After 3 months, both groups showed further improvement in all parameters without significant differences between them. Conclusions: APC and HOT were effective, safe and decreased the tissue toxicity scores in patients with CRP. However, response rate was higher and faster in the APC group.Introducción: la proctopatía por radiación (PPR se asocia con rectorragía recurrente y requerimientos de trasfusiones. La coagulación con argón plasma (APC y la terapia con oxígeno hiperbárico (HOT han sido efectivas en el control de la PPR. No hay estudios prospectivos comparativos entre ambas técnicas. Objetivo: el objetivo del estudio es evaluar la efectividad

  16. Emission spectroscopy on a supersonically expanding argon/silane plasma

    NARCIS (Netherlands)

    Meeusen, G.J.; Ershov-Pavlov, E.A.; Meulenbroeks, R.F.G.; Sanden, van de M.C.M.; Schram, D.C.

    1992-01-01

    Results from emission spectroscopy measurements on an Ar/SiH/sub 4/ plasma jet which is used for fast deposition of amorphous hydrogenated silicon are presented. The jet is produced by allowing a thermal cascaded arc plasma in argon (I=60 A, V=80 V, Ar flow=60 scc/s and pressure 4*10/sup 4/ Pa) to

  17. Measurement of the argon plasma temperature by use of pyrometer

    International Nuclear Information System (INIS)

    Wang Fanhou; Jing Fuqian

    2002-01-01

    The author describes in detail how to use pyrometer to measure the plasma temperature. The temperatures of shock-generated argon plasmas are given in the present work. Measured results of temperature-pressure curve are compared with calculated results using Saha-Debye-Huckel model, which are in good agreement

  18. Argon Beam Coagulator in Breast Surgery: Effect on the Incidence of Breast Seroma.

    Science.gov (United States)

    Lefemine, Valentina; Cornish, Julie A; Abou-Samra, Walid

    2011-12-01

    Although Argon Beam Coagulators (ABCs) are widely used in urological and gynecological procedures, there have been only two studies published so far on their use and benefits in breast surgery. This study compares the incidence of breast seroma following mastectomy upon the use of ABC versus standard monopolar diathermy. This is a retrospective cohort study, with data collected from January 2006 to August 2008 for all patients who underwent a simple mastectomy and axillary surgery. Outcomes included incidence of seroma, amount of drainage on day of discharge, and timing of seroma formation. Fifty-six patients were studied, with 30 undergoing simple mastectomy using ABC diathermy and 25 using simple diathermy. The incidence of postoperative breast seroma development was 30% (n = 9) in the former group and 36% (n = 9) in the latter. In the ABC group, a high postoperative drainage at discharge was predictive of developing a seroma; this was not observed in the monopolar group. The search for methods to reduce the incidence of seroma in breast surgery is ongoing worldwide. Despite a previous report, this study failed to show any significant difference between ABC and monopolar diathermy in the incidence of breast seroma formation following simple mastectomy and axillary surgery. ABC diathermy is more costly, and its use needs to be carefully considered in an era of a stretched National Health Service financial budget.

  19. Behavior of Excited Argon Atoms in Inductively Driven Plasmas

    International Nuclear Information System (INIS)

    HEBNER, GREGORY A.; MILLER, PAUL A.

    1999-01-01

    Laser induced fluorescence has been used to measure the spatial distribution of the two lowest energy argon excited states, 1s 5 and 1s 4 , in inductively driven plasmas containing argon, chlorine and boron trichloride. The behavior of the two energy levels with plasma conditions was significantly different, probably because the 1s 5 level is metastable and the 1s 4 level is radiatively coupled to the ground state but is radiation trapped. The argon data is compared with a global model to identify the relative importance of processes such as electron collisional mixing and radiation trapping. The trends in the data suggest that both processes play a major role in determining the excited state density. At lower rfpower and pressure, excited state spatial distributions in pure argon were peaked in the center of the discharge, with an approximately Gaussian profile. However, for the highest rfpowers and pressures investigated, the spatial distributions tended to flatten in the center of the discharge while the density at the edge of the discharge was unaffected. The spatially resolved excited state density measurements were combined with previous line integrated measurements in the same discharge geometry to derive spatially resolved, absolute densities of the 1s 5 and 1s 4 argon excited states and gas temperature spatial distributions. Fluorescence lifetime was a strong fi.mction of the rf power, pressure, argon fraction and spatial location. Increasing the power or pressure resulted in a factor of two decrease in the fluorescence lifetime while adding Cl 2 or BCl 3 increased the fluorescence lifetime. Excited state quenching rates are derived from the data. When Cl 2 or BCl 3 was added to the plasma, the maximum argon metastable density depended on the gas and ratio. When chlorine was added to the argon plasma, the spatial density profiles were independent of chlorine fraction. While it is energetically possible for argon excited states to dissociate some of the

  20. Features of copper etching in chlorine-argon plasma

    International Nuclear Information System (INIS)

    Efremov, A.M.; Svettsov, V.I.

    1995-01-01

    Chlorine mixtures with inert gases including argon exhibit promise as plasma feed gases for etching metals and semiconductors in the microelectronics industry. It was shown that even strong dilution of reactive gas with an inert gas (up to 80-90% of the latter) has virtually no effect in decreasing the rate of plasma etching of materials such as silicon and gallium arsenide, compared to etching in pure chlorine. The principal reactive species responsible for etching these substrates are chlorine atoms therefore, a possible explanation of the effect is an increase in the rate of bulk generation of chlorine atoms in the presence of argon. In this work the authors studied the influence of argon on the rate of copper etching in chlorine, because copper, unlike the above substrates, reacts effectively not only with the atoms but with the ground-state molecules of chlorine

  1. Opacity measurements in shock-generated argon plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Erskine, D.

    1993-07-01

    Dense plasmas having uniform and constant density and temperature are generated by passage of a planar shock wave through gas. The opacity of the plasma is accurately measured versus wavelength by recording the risetime of emitted light. This technique is applicable to a wide variety of species and plasma conditions. Initial experiments in argon have produced plasmas with 2 eV temperatures, 0.004--0.04 g/cm{sup 3} densities, and coupling parameters {Gamma} {approximately}0.3--0.7. Measurements in visible light are compared with calculations using the HOPE code. An interesting peak in the capacity at 400 nm is observed for the first time and is identified with the 4s-5p transition in excited neutral argon atoms.

  2. Behavior of Excited Argon Atoms in Inductively Driven Plasmas

    CERN Document Server

    Hebner, G A

    1999-01-01

    Laser induced fluorescence has been used to measure the spatial distribution of the two lowest energy argon excited states, 1s sub 5 and 1s sub 4 , in inductively driven plasmas containing argon, chlorine and boron trichloride. The behavior of the two energy levels with plasma conditions was significantly different, probably because the 1s sub 5 level is metastable and the 1s sub 4 level is radiatively coupled to the ground state but is radiation trapped. The argon data is compared with a global model to identify the relative importance of processes such as electron collisional mixing and radiation trapping. The trends in the data suggest that both processes play a major role in determining the excited state density. At lower rfpower and pressure, excited state spatial distributions in pure argon were peaked in the center of the discharge, with an approximately Gaussian profile. However, for the highest rfpowers and pressures investigated, the spatial distributions tended to flatten in the center of the disch...

  3. Numerical study of some operating characteristics for argon induction plasmas

    International Nuclear Information System (INIS)

    Ebihara, K.

    1978-01-01

    Some operating characteristics of argon induction plasmas at atmospheric pressure were obtained numerically by using magnetohydrodynamic equations. From these characteristics we can estimate the general dependency of plasma temperatures on operating conditions for induction plasmas. Calculated relationships between the sustaining electric field strength at the plasma surface and the electric power input show the existence of a minimum value of the field strength, the reason for which is revealed by detailed investigation of the calculated radial temperature distributions. Further, it was found that the minimum increases almost linearly with increasing frequency. In addition, characteristics of the Poynting vector and heat conduction loss at the plasma surface were obtained. Some characteristics obtained here give practical information on the electromagnetic field which is necessary to maintain the steady plasmas

  4. Laser-induced fluorescence measurements of argon ion velocities near the sheath boundary of an argon-xenon plasma

    International Nuclear Information System (INIS)

    Lee, Dongsoo; Severn, Greg; Oksuz, Lutfi; Hershkowitz, Noah

    2006-01-01

    The Bohm sheath criterion in single- and two-ion species plasma is studied with laser-induced fluorescence using a diode laser. Xenon is added to a low pressure unmagnetized dc hot filament argon discharge confined by surface multidipole magnetic fields. The Ar II transition at 668.614 nm is adopted for optical pumping to detect the fluorescence from the plasma and to measure the argon ion velocity distribution functions with respect to positions relative to a negatively biased boundary plate. The structures of the plasma sheath and presheath are measured by an emissive probe. The ion concentrations of the two-species in the bulk plasma are calculated from ion acoustic wave experiments. Results are compared with previous experiments of Ar-He plasmas in which the argon ions were the heavier ion species. Unlike the previous results, the argon speed is slower than its own Bohm velocity near the sheath-presheath boundary in the Ar-Xe plasma where argon ions are the lighter ion species. We argue that this result is consistent with the behaviour of the helium ion required by the generalized Bohm criterion in the previous experiments with Ar-He plasmas. Further, our results suggest that the measured argon ion speed approaches the ion sound speed of the system

  5. Modelling of Argon Cold Atmospheric Plasmas for Biomedical Applications

    Science.gov (United States)

    Atanasova, M.; Benova, E.; Degrez, G.; van der Mullen, J. A. M.

    2018-02-01

    Plasmas for biomedical applications are one of the newest fields of plasma utilization. Especially high is the interest toward plasma usage in medicine. Promising results are achieved in blood coagulation, wound healing, treatment of some forms of cancer, diabetic complications, etc. However, the investigations of the biomedical applications from biological and medical viewpoint are much more advanced than the studies on the dynamics of the plasma. In this work we aim to address some specific challenges in the field of plasma modelling, arising from biomedical applications - what are the plasma reactive species’ and electrical fields’ spatial distributions as well as their production mechanisms; what are the fluxes and energies of the various components of the plasma delivers to the treated surfaces; what is the gas flow pattern? The focus is on two devices, namely the capacitive coupled plasma jet and the microwave surface wave sustained discharge. The devices are representatives of the so called cold atmospheric plasmas (CAPs). These are discharges characterized by low gas temperature - less than 40°C at the point of application - and non-equilibrium chemistry.

  6. Observations of acoustic-wave-induced superluminescence in an argon plasma

    International Nuclear Information System (INIS)

    Aramyan, A.R.

    2003-01-01

    It is shown that in an argon discharge plasma it is possible to obtain overpopulation of certain electronic levels of atomic argon under the influence of acoustic waves. When the specified threshold is exceeded, then a superluminescence (in the form of light flashes) from the overpopulated electronic levels of atomic argon is observed

  7. Relaxation rates studies in an argon cylindrical plasma

    International Nuclear Information System (INIS)

    Hernandez, M.A.; Dengra, A.; Colomer, V.

    1986-01-01

    The single Langmuir probe method has been used to determine the relaxation rates of the electron density and temperature in an argon afterglow dc cylindrical plasma. The ion-electron recombination was found to be the fundamental mechanism of density decay during the early afterglow while the ambipolar diffusion controlles the density decay for later afterglow. Electron temperature cooling curves have been interpreted via electron-neutral collisons. Measurements of the electron-ion recombination and the ambipolar diffusion coefficients have been made, as well as of the electron-neutral collision frequency and the momentum transfer cross sections. Good agreement is obtained with previously published data. (author)

  8. A Retrospective Analysis of Hemostatic Techniques in Primary Total Knee Arthroplasty: Traditional Electrocautery, Bipolar Sealer, and Argon Beam Coagulation.

    Science.gov (United States)

    Rosenthal, Brett D; Haughom, Bryan D; Levine, Brett R

    2016-01-01

    In this retrospective cohort study of 280 primary total knee arthroplasties, clinical outcomes relevant to hemostasis were compared by electrocautery type: traditional electrocautery (TE), bipolar sealer (BS), and argon beam coagulation (ABC). Age, sex, and preoperative diagnosis were not significantly different among the TE, BS, and ABC cohorts. The 3 hemostasis systems were statistically equivalent with respect to estimated blood loss. Wound drainage during the first 48 hours after surgery was equivalent between the BS and ABC cohorts but less for the TE cohort. Transfusion requirements were not significantly different among the cohorts. The 3 hemostasis systems were statistically equivalent with respect to mean change in hemoglobin level during the early postoperative period (levels were measured on postoperative day 1 and on discharge). As BS and ABC are clinically equivalent to TE, their increased cost may not be justified.

  9. Comparative thermometric coagulation studies of plasmas from normal outbred Swiss Webster mice and persons.

    Science.gov (United States)

    Tsang, V C; Wyatt, C R; Damian, R T

    1979-06-01

    The functional capabilities of a thermometric clot-timer have been demonstrated in a comparative study of human and mouse plasma coagulation. The influence of some variables on coagulation times of mouse and human plasmas were examined in activated partial thromboplastin time, one-stage prothrombin time, and Russell's viper venom time assays. Mouse plasma coagulation times were generally shorter and more reproducible than those of human plasma. Optimal assay conditions are also described.

  10. Effect of the levitating microparticle cloud on radiofrequency argon plasma

    International Nuclear Information System (INIS)

    Mitic, S.; Pustylnik, M. Y.; Klumov, B. A.; Morfill, G. E.

    2010-01-01

    The effect of a levitating cloud of microparticles on the parameters of a radiofrequency (RF) plasma has been studied by means of two experimental techniques. Axial distributions of 1s excited states of argon were measured by a self-absorption method. A correction of a standard self-absorption method for the extinction of the light by the levitating microparticles is proposed. In addition the electron temperature was estimated using the optical emission spectroscopy. Measurements at the same discharge conditions in a microparticle-free discharge and discharge, containing a cloud of levitating microparticles, revealed the non-local influence of the microparticle cloud on the discharge plasma. The most probable cause of this influence is the disturbance of the ionization balance by the levitating microparticles.

  11. Comparison study of nitrogen and argon processing in a plasma arc centrifugal treatment system

    International Nuclear Information System (INIS)

    Shuey, M.; Tsuji, Y.

    2000-01-01

    Recent testing performed at the plasma research center of Retech Services, Inc. compared nitrogen with argon as plasma gas in the processing of simulated wastes. The testing took place in a full-scale production PACT system under a cooperative research and development study between Retech Services Inc. and Toyo Engineering Corporation. This study shows that simulated waste can be processed by both nitrogen and argon plasmas. Heat losses to the torch nozzle were significantly lower with argon and should be studied further. Both argon and nitrogen plasma were able to process feeds containing both metals and oxides. Some of the drawbacks to using argon plasma are cost, higher volume flow rates, and dual mode torch nozzle erosion. (authors)

  12. About the EDF formation in a capacitively coupled argon plasma

    International Nuclear Information System (INIS)

    Tatanova, M; Thieme, G; Basner, R; Hannemann, M; Golubovskii, Yu B; Kersten, H

    2006-01-01

    The formation of the electron distribution function (EDF) in the bulk plasma of a capacitively coupled radio-frequency (rf) discharge in argon generated in the plasma-chemical reactor PULVA-INP is investigated experimentally and theoretically. Measurements of the EDF and internal plasma parameters were performed by means of a Langmuir probe at pressures of 0.5-100 Pa and discharge powers of 5-100 W. The observed EDFs have revealed a two-temperature behaviour at low pressures and evolved into a Maxwellian distribution at high gas pressures and large discharge powers. Theoretical determination of the EDF is based on the numerical solution of the Boltzmann kinetic equation in the local and non-local approaches under experimental conditions. The model includes elastic and inelastic electron-atom collisions and electron-electron interactions. Low electron temperatures and relatively high ionization degrees are the features of the PULVA-INP rf discharge. This leads to significant influence of the electron-electron collisions on the EDF formation. The modelled and measured distributions show good agreement in a wide range of discharge parameters, except for a range of low gas pressures, where the stochastic electron heating is intense. Additionally, mechanisms of the EDF formation in the dc and rf discharge were compared under similar discharge conditions

  13. About the EDF formation in a capacitively coupled argon plasma

    Energy Technology Data Exchange (ETDEWEB)

    Tatanova, M [Institute of Physics, Saint-Petersburg State University, ul. Ulianovskaja 1, 198504 Saint-Petersburg (Russian Federation); Thieme, G [Institut fur Niedertemperatur-Plasmaphysik, Friedrich-Ludwig-Jahn-Str 19, D-17489 Greifswald (Germany); Basner, R [Institut fur Niedertemperatur-Plasmaphysik, Friedrich-Ludwig-Jahn-Str 19, D-17489 Greifswald (Germany); Hannemann, M [Institut fur Niedertemperatur-Plasmaphysik, Friedrich-Ludwig-Jahn-Str 19, D-17489 Greifswald (Germany); Golubovskii, Yu B [Institute of Physics, Saint-Petersburg State University, ul. Ulianovskaja 1, 198504 Saint-Petersburg (Russian Federation); Kersten, H [Institut fur Niedertemperatur-Plasmaphysik, Friedrich-Ludwig-Jahn-Str 19, D-17489 Greifswald (Germany)

    2006-08-01

    The formation of the electron distribution function (EDF) in the bulk plasma of a capacitively coupled radio-frequency (rf) discharge in argon generated in the plasma-chemical reactor PULVA-INP is investigated experimentally and theoretically. Measurements of the EDF and internal plasma parameters were performed by means of a Langmuir probe at pressures of 0.5-100 Pa and discharge powers of 5-100 W. The observed EDFs have revealed a two-temperature behaviour at low pressures and evolved into a Maxwellian distribution at high gas pressures and large discharge powers. Theoretical determination of the EDF is based on the numerical solution of the Boltzmann kinetic equation in the local and non-local approaches under experimental conditions. The model includes elastic and inelastic electron-atom collisions and electron-electron interactions. Low electron temperatures and relatively high ionization degrees are the features of the PULVA-INP rf discharge. This leads to significant influence of the electron-electron collisions on the EDF formation. The modelled and measured distributions show good agreement in a wide range of discharge parameters, except for a range of low gas pressures, where the stochastic electron heating is intense. Additionally, mechanisms of the EDF formation in the dc and rf discharge were compared under similar discharge conditions.

  14. Study on electron density and average degree of ionization for the non-ideal argon plasmas

    International Nuclear Information System (INIS)

    Jing Ming; Huang Hua; Zhou Yisu; Wang Caixia

    2008-01-01

    Electron density and average degree of ionization of the non-ideal argon plasmas under different plasma temperature and density are calculated by using SHM model. It comes to a conclusion that the average degree of ionization is less than 0.5 for the non-ideal argon plasmas at temperature T=2.0eV and plasma density ρ=(0.01-0.5)g·cm -3 , and the average degree of ionization is reduced with the increase of plasma density ρ. This indicates that the non-ideal argon plasma has a very low degree of ionization so that most argon has not been ionized. In addition, the discussion on the ionization decrease with the increase of plasma density ρ is given. (authors)

  15. Nonthermal Argon Plasma Generator and Some Potential Applications

    Directory of Open Access Journals (Sweden)

    Bunoiu M.

    2015-12-01

    Full Text Available A laboratory - made nonthermal plasma generator is presented. It has a diameter of 0.020 m and length of 0.155 m and contains two electrodes. The first electrode is a 2% Th-W alloy, 0.002 m in diameter bar, centred inside the generator’s body by means of a four channel teflon piece; the other three channels, 0.003 m in diameter, are used for Ar supply. The second electrode is a nozzle of 0.002 m - 0.008 m diameter and 0.005m length. A ~500 kV/m electric field is generated between the two electrodes by a high frequency source (13.56 MHz ±5%, equipped with a OT-1000 (Tungsram power triode. For Ar flows ranging from 0.00008 m3/s to 0.00056 m3/s, a plasma jet of length not exceeding 0.015 m and temperature below 315 K is obtained. Anthurium andraeanumis sample , blood matrix, human hair and textile fibers may be introduced in the plasma jet. For time periods of 30 s and 60 s, various effects like, cell detexturization, fast blood coagulation or textile fiber or hair cleaning and smoothing are obtained. These effects are presented and discussed in the paper.

  16. Role of metastable atoms in argon-diluted silane Rf plasmas

    International Nuclear Information System (INIS)

    Sansonnens, L.; Howling, A.A.; Hollenstein, C.; Dorier, J.L.; Kroll, U.

    1994-01-01

    The evolution of the argon metastable density has been studied by absorption spectroscopy in power-modulated plasmas of argon and a mixture of 4% silane in argon. A small concentration of silane suppresses the argon metastable density by molecular quenching. This molecular quenching adds to the electronic collisional dissociation to increase the silane dissociation rate as compared with pure silane plasmas. Using time-resolved emission spectroscopy, the role of metastables in excitation to the argon 2P 2 state has been determined in comparison with production from the ground state. In silane plasmas, emission from SiH* is due essentially to electron impact dissociation of silane, whereas in 4% silane-in-argon plasmas, emission from SiH* seems to be due to electron impact excitation of the SiH ground state. These studies demonstrate that argon is not simply a buffer gas but has an influence on the dissociation rate in the plasma-assisted deposition of amorphous silicon using argon-diluted silane plasmas. (author) 7 figs., 30 refs

  17. Alternating current electrical properties of Argon plasma treated jute

    Directory of Open Access Journals (Sweden)

    Md. Masroor Anwer

    2012-09-01

    Full Text Available Low temperature plasma (LTP treatment, a kind of environment friendly surface modification technique, was applied to biodegradable and environment friendly jute fibre with the use of nonpolymerizing gas, namely argon, at various discharge power levels and exposure times with a definite flow rate. Scanning electron microscopy (SEM microphotographs reveal that the roughness of the fibre surfaces increases with the increase of discharge power and exposure time. This is caused due to the bombardment of high energetic ions on the fibre surface and the fibres become sputtered. The capacitance and the electrical conductance of raw and LTP treated jute fibre were measured as a function of frequency at room temperature. The dielectric constant, conductivity, dielectric loss-tangent and the surface morphology of raw and LTP treated jute as a function of frequency were studied at room temperature. It was observed that for all the samples the dielectric constant almost constant at lower frequencies and then decreases gradually in the high frequency region. In addition, dielectric constant increases with the increase of plasma treatment time as well as discharge power. It is also observed for all the samples that the conductivity increases as the frequency increases with a lower slope in the low frequency region and with a higher slope in the higher frequency region. In addition, the conductivity decreases with the increase of plasma exposure time as well as discharge power. The conductivity increases with frequency due to the hopping mechanism of electrons. The dependence of the dielectric loss-tangent with frequency at different treatment times and discharge powers for all the jute samples show small relaxation peaks in the very low frequency region. The dielectric loss-tangent decreases with the increase of both plasma treatment time and discharge power. In addition, the relaxation peaks are shifted to the higher frequency region as the plasma treatment

  18. Modeling of inhomogeneous mixing of plasma species in argon-steam arc discharge

    Science.gov (United States)

    Jeništa, J.; Takana, H.; Uehara, S.; Nishiyama, H.; Bartlová, M.; Aubrecht, V.; Murphy, A. B.

    2018-01-01

    This paper presents numerical simulation of mixing of argon- and water-plasma species in an argon-steam arc discharge generated in a thermal plasma generator with the combined stabilization of arc by axial gas flow (argon) and water vortex. The diffusion of plasma species itself is described by the combined diffusion coefficients method in which the coefficients describe the diffusion of argon ‘gas,’ with respect to water vapor ‘gas.’ Diffusion processes due to the gradients of mass density, temperature, pressure, and an electric field have been considered in the model. Calculations for currents 150-400 A with 15-22.5 standard liters per minute (slm) of argon reveal inhomogeneous mixing of argon and oxygen-hydrogen species with the argon species prevailing near the arc axis. All the combined diffusion coefficients exhibit highly nonlinear distribution of their values within the discharge, depending on the temperature, pressure, and argon mass fraction of the plasma. The argon diffusion mass flux is driven mainly by the concentration and temperature space gradients. Diffusions due to pressure gradients and due to the electric field are of about 1 order lower. Comparison with our former calculations based on the homogeneous mixing assumption shows differences in temperature, enthalpy, radiation losses, arc efficiency, and velocity at 400 A. Comparison with available experiments exhibits very good qualitative and quantitative agreement for the radial temperature and velocity profiles 2 mm downstream of the exit nozzle.

  19. Numerical simulation of nonequilibrium effects in an argon plasma jet

    International Nuclear Information System (INIS)

    Chang, C.H.; Ramshaw, J.D.

    1994-01-01

    Departures from thermal (translational), ionization, and excitation equilibrium in an axisymmetric argon plasma jet have been studied by two-dimensional numerical simulations. Electrons, ions, and excited and ground states of neutral atoms are represented as separate chemical species in the mixture. Transitions between excited states, as well as ionization/recombination reactions due to both collisional and radiative processes, are treated as separate chemical reactions. Resonance radiation transport is represented using Holstein escape factors to simulate both the optically thin and optically thick limits. The optically thin calculation showed significant underpopulation of excited species in the upstream part of the jet core, whereas in the optically thick calculation this region remains close to local thermodynamic equilibrium, consistent with previous experimental observations. Resonance radiation absorption is therefore an important effect. The optically thick calculation results also show overpopulations (relative to equilibrium) of excited species and electron densities in the fringes and downstream part of the jet core. In these regions, however, the electrons and ions are essentially in partial local thermodynamic equilibrium with the excited state at the electron temperature, even though the ionized and excited states are no longer in equilibrium with the ground state. Departures from partial local thermodynamic equilibrium are observed in the outer fringes and far downstream part of the jet. These results are interpreted in terms of the local relative time scales for the various physical and chemical processes occurring in the plasma

  20. Calculation of high-pressure argon plasma parameters produced by excimer laser

    International Nuclear Information System (INIS)

    Tsuda, Norio; Yamada, Jun

    2000-01-01

    When a XeCl excimer laser light was focused in a high-pressure argon gas up to 150 atm, a dense plasma developed not only backward but also forward. It is important to study on the electron density and temperature of the laser-induced plasma in the high-pressure gas. The electron density and temperature in high-pressure argon plasma produced by XeCl excimer laser has been calculated and compared with the experimental data. (author)

  1. The influence of nitrogen entrainment on argon plasmas created by the 'Torche à Injection Axiale' (TIA)

    NARCIS (Netherlands)

    Jonkers, J.; Hartgers, A.; Selen, L.J.M.; Mullen, van der J.J.A.M.; Schram, D.C.

    1999-01-01

    When a plasma is sustained in the open air, nitrogen will diffuse into the plasma. Especially for plasmas sustained by the `Torche à Injection Axiale' (TIA) this appears to be the case, since this turbulent jet draws gases from the surroundings. In the argon plasma the entrained nitrogen is probably

  2. Saturation spectroscopy of an optically opaque argon plasma

    Science.gov (United States)

    Eshel, Ben; Rice, Christopher A.; Perram, Glen P.

    2018-02-01

    A pure argon (Ar) plasma formed by a capacitively coupled radio-frequency discharge was analyzed using Doppler-free saturation spectroscopy. The expected line shape was a characteristic of sub-Doppler spectra in the presence of velocity-changing collisions, a narrow Lorentzian centered on a Doppler pedestal, but the observed line shapes contain a multi-peak structure, attributed to opacity of the medium. Laser absorption and inter-modulated fluorescence spectroscopy measurements were made to validate opacity as a driving factor of the observed line shapes. Spectral line shapes are further complicated by the spatial dependence of the pump laser, probe laser and of the absorbing medium, as well as the large absorbance of the transition under investigation. A numerical line shape was derived by accounting for the spatial variation of the pump and probe with a saturated line shape obtained from the rate equations for an equivalent two-level system. This simulated line shape shows good qualitative agreement with the trends observed in the data.

  3. Death during laparoscopy: can 1 gas push out another? Danger of argon electrocoagulation.

    Science.gov (United States)

    Sezeur, Alain; Partensky, Christian; Chipponi, Jacques; Duron, Jean-Jacques

    2008-08-01

    We report the death of a young man during a laparoscopic partial splenectomy performed with an argon plasma coagulator to remove a benign cyst. The report analyzes the very particular mechanism of a gas embolism, which caused death here. This analysis leads us to recommend a close attention on the use of argon coagulators during laparoscopy. The aim of this article is to draw surgeons' attention to the conclusions of a court-ordered expert assessment intended to elucidate the mechanisms responsible for the death of a 20-year-old man during a laparoscopic partial splenectomy performed with an argon plasma coagulator to remove a benign cyst.

  4. Imaging of blood plasma coagulation at supported lipid membranes.

    Science.gov (United States)

    Faxälv, Lars; Hume, Jasmin; Kasemo, Bengt; Svedhem, Sofia

    2011-12-15

    The blood coagulation system relies on lipid membrane constituents to act as regulators of the coagulation process upon vascular trauma, and in particular the 2D configuration of the lipid membranes is known to efficiently catalyze enzymatic activity of blood coagulation factors. This work demonstrates a new application of a recently developed methodology to study blood coagulation at lipid membrane interfaces with the use of imaging technology. Lipid membranes with varied net charges were formed on silica supports by systematically using different combinations of lipids where neutral phosphocholine (PC) lipids were mixed with phospholipids having either positively charged ethylphosphocholine (EPC), or negatively charged phosphatidylserine (PS) headgroups. Coagulation imaging demonstrated that negatively charged SiO(2) and membrane surfaces exposing PS (obtained from liposomes containing 30% of PS) had coagulation times which were significantly shorter than those for plain PC membranes and EPC exposing membrane surfaces (obtained from liposomes containing 30% of EPC). Coagulation times decreased non-linearly with increasing negative surface charge for lipid membranes. A threshold value for shorter coagulation times was observed below a PS content of ∼6%. We conclude that the lipid membranes on solid support studied with the imaging setup as presented in this study offers a flexible and non-expensive solution for coagulation studies at biological membranes. It will be interesting to extend the present study towards examining coagulation on more complex lipid-based model systems. Copyright © 2011 Elsevier Inc. All rights reserved.

  5. Plasma concentrations of blood coagulation factor VII measured by immunochemical and amidolytic methods

    DEFF Research Database (Denmark)

    Bladbjerg, E-M; Gram, J; Jespersen, J

    2000-01-01

    Ever since the coagulant activity of blood coagulation factor VII (FVII:C) was identified as a risk indicator of cardiac death, a large number of studies have measured FVII protein concentrations in plasma. FVII protein concentrations are either measured immunologically with an ELISA method (FVII...

  6. Effects of assistant anode on planar inductively coupled magnetized argon plasma in plasma immersion ion implantation

    International Nuclear Information System (INIS)

    Tang, Deli; Chu, Paul K.

    2003-01-01

    The enhancement of planar radio frequency (RF) inductively coupled argon plasma is studied in the presence of an assistant anode and an external magnetic field at low pressure. The influence of the assistant anode and magnetic field on the efficiency of RF power absorption and plasma parameters is investigated. An external axial magnetic field is coupled into the plasma discharge region by an external electromagnetic coil outside the discharge chamber and an assistant cylindrical anode is inserted into the discharge chamber to enhance the plasma discharge. The plasma parameters and density profile are measured by an electrostatic Langmuir probe at different magnetic fields and anode voltages. The RF power absorption by the plasma can be effectively enhanced by the external magnetic field compared with the nonmagnetized discharge. The plasma density can be further increased by the application of a voltage to the assistant anode. Owing to the effective power absorption and enhanced plasma discharge by the assistant anode in a longitudinal magnetic field, the plasma density can be enhanced by more than a factor of two. Meanwhile, the nonuniformity of the plasma density is less than 10% and it can be achieved in a process chamber with a diameter of 600 mm

  7. Tissue Factor Coagulant Activity is Regulated by the Plasma Membrane Microenvironment.

    Science.gov (United States)

    Yu, Yuanjie; Böing, Anita N; Hau, Chi M; Hajji, Najat; Ruf, Wolfram; Sturk, Auguste; Nieuwland, Rienk

    2018-06-01

     Tissue factor (TF) can be present in a non-coagulant and coagulant form. Whether the coagulant activity is affected by the plasma membrane microenvironment is unexplored.  This article studies the presence and coagulant activity of human TF in plasma membrane micro-domains.  Plasma membranes were isolated from human MIA PaCa2 cells, MDA-MB-231 cells and human vascular smooth muscle cells by Percoll gradient ultracentrifugation after cell disruption. Plasma membranes were fractionated by OptiPrep gradient ultracentrifugation, and the presence of TF, flotillin, caveolin, clathrin, protein disulphide isomerase (PDI), TF pathway inhibitor (TFPI) and phosphatidylserine (PS) were determined.  Plasma membranes contain two detergent-resistant membrane (DRM) compartments differing in density and biochemical composition. High-density DRMs (DRM-H) have a density ( ρ ) of 1.15 to 1.20 g/mL and contain clathrin, whereas low-density DRMs (DRM-L) have a density between 1.09 and 1.13 g/mL and do not contain clathrin. Both DRMs contain TF, flotillin and caveolin. PDI is detectable in DRM-H, TFPI is not detectable in either DMR-H or DRM-L and PS is detectable in DRM-L. The DRM-H-associated TF (> 95% of the TF antigen) lacks detectable coagulant activity, whereas the DRM-L-associated TF triggers coagulation. This coagulant activity is inhibited by lactadherin and thus PS-dependent, but seemed insensitive to 16F16, an inhibitor of PDI.  Non-coagulant and coagulant TF are present within different types of DRMs in the plasma membrane, and the composition of these DRMs may affect the TF coagulant activity. Schattauer GmbH Stuttgart.

  8. Non-local thermodynamic equilibrium effects on isentropic coefficient in argon and helium thermal plasmas

    International Nuclear Information System (INIS)

    Sharma, Rohit; Singh, Kuldip

    2014-01-01

    In the present work, two cases of thermal plasma have been considered; the ground state plasma in which all the atoms and ions are assumed to be in the ground state and the excited state plasma in which atoms and ions are distributed over various possible excited states. The variation of Zγ, frozen isentropic coefficient and the isentropic coefficient with degree of ionization and non-equilibrium parameter θ(= T e /T h ) has been investigated for the ground and excited state helium and argon plasmas at pressures 1 atm, 10 atm, and 100 atm in the temperature range from 6000 K to 60 000 K. For a given value of non-equilibrium parameter, the relationship of Zγ with degree of ionization does not show any dependence on electronically excited states in helium plasma whereas in case of argon plasma this dependence is not appreciable till degree of ionization approaches 2. The minima of frozen isentropic coefficient shifts toward lower temperature with increase of non-equilibrium parameter for both the helium and argon plasmas. The lowering of non-equilibrium parameter decreases the frozen isentropic coefficient more emphatically in helium plasma at high pressures in comparison to argon plasma. The increase of pressure slightly reduces the ionization range over which isentropic coefficient almost remains constant and it does not affect appreciably the dependence of isentropic coefficient on non-equilibrium parameter

  9. Electrical and spectroscopic diagnostic of an atmospheric double arc argon plasma jet

    International Nuclear Information System (INIS)

    Tu, X; Cheron, B G; Yan, J H; Cen, K F

    2007-01-01

    An atmospheric argon plasma jet generated by an original dc double anode plasma torch has been investigated through its electrical and spectroscopic diagnostics. The arc instabilities and dynamic behavior of the argon plasma are analyzed using classical tools such as the statistical method, fast Fourier transform (FFT) and correlation function. The takeover mode is identified as the fluctuation characteristic of the double arc argon plasma jet in our experiment. The FFT and correlation analysis of electrical signals exhibit the only characteristic frequency of 150 Hz, which originates from the torch power and is independent of any change in the operating parameters. No high frequency fluctuations (1-15 kHz) are observed. This indicates that the nature of fluctuations in an argon plasma jet is induced mainly by the undulation of the tri-phase rectified power supply. It is found that each arc root attachment is diffused rather than located at a fixed position on the anode wall. Moreover, the emission spectroscopic technique is performed to determine the electron temperature and number density of the plasma jet inside and outside the arc chamber. Along the torch axis, the measured electron temperature and number density of the double arc argon plasma drop from 12 300 K and 7.6 x 10 22 m -3 at the divergent part of the first anode nozzle, to 10 500 K and 3.1 x 10 22 m -3 at the torch exit. In addition, the validity criteria of the local thermodynamic equilibrium (LTE) state in the plasma arc are examined. The results show that the measured electron densities are in good agreement with those calculated from the LTE model, which indicates that the double arc argon plasma at atmospheric pressure is close to the LTE state under our experimental conditions

  10. Spectroscopic characterization of post-cluster argon plasmas during the blast wave expansion

    International Nuclear Information System (INIS)

    Chung, H.-K.; Fournier, K.B.; Edwards, M.J.; Scott, H.A.; Lee, R.W.; Cattolica, R.; Ditmire, T.

    2002-01-01

    In this work we present temperature diagnostics of an expanding laser-produced argon plasma. A short-pulse (35fs) laser with an intensity of I = 1017 W/cm deposits ∼ 100 mJ of energy into argon clusters. This generates a hot plasma filament that develops into a cylindrically expanding shock. We develop spectral diagnostics for the temperatures of the argon plasma in the shock region and the preionized region ahead of the shock. A collisional-radiative model is applied to explore line intensity ratios derived from Ar II-Ar IV spectra that are sensitive to temperatures in a few eV range. The results of hydrodynamic simulations are employed to derive a time dependent radiative transport calculation that generates the theoretical emission spectra from the expanding plasma

  11. Spectroscopic Characterization of Post-Cluster Argon Plasmas During the Blast Wave Expansion

    International Nuclear Information System (INIS)

    Ching, H-K.; Fournier, K.B.; Edwards, M.J.; Scott, H.A.; Cattolica, R.; Ditmire, T.; Lee, R.W.

    2002-01-01

    In this work we present temperature diagnostics of an expanding laser-produced argon plasma. A short-pulse (35fs) laser with an intensity of I = 10 17 W/cm 2 deposits ∼ 100 mJ of energy into argon clusters. This generates a hot plasma filament that develops into a cylindrically expanding shock. We develop spectral diagnostics for the temperatures of the argon plasma in the shock region and the preionized region ahead of the shock. A collisional-radiative model is applied to explore line intensity ratios derived from Ar II - Ar IV spectra that are sensitive to temperatures in a few eV range. The results of hydrodynamic simulations are employed to derive a time dependent radiative transport calculation that generates the theoretical emission spectra from the expanding plasma

  12. Argon plasma treatment to enhance the electrochemical reactivity of screen-printed carbon surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Ghamouss, F.; Luais, E. [Universite de Nantes, Faculte des Sciences et des Techniques, Chimie et Interdisciplinarite: Synthese, Analyse, Modelisation (CEISAM), UMR CNRS no 6230, 2, rue de la Houssiniere, BP 92208, 44322 NANTES Cedex 3 (France); Universite de Nantes, Institut des Materiaux Jean Rouxel IMN - CNRS, 2 rue de la Houssiniere, BP 32229, 44322 Nantes Cedex 3 (France); Thobie-Gautier, C. [Universite de Nantes, Faculte des Sciences et des Techniques, Chimie et Interdisciplinarite: Synthese, Analyse, Modelisation (CEISAM), UMR CNRS no 6230, 2, rue de la Houssiniere, BP 92208, 44322 NANTES Cedex 3 (France); Tessier, P.-Y. [Universite de Nantes, Faculte des Sciences et des Techniques, Chimie et Interdisciplinarite: Synthese, Analyse, Modelisation (CEISAM), UMR CNRS no 6230, 2, rue de la Houssiniere, BP 92208, 44322 NANTES Cedex 3 (France); Universite de Nantes, Institut des Materiaux Jean Rouxel IMN - CNRS, 2 rue de la Houssiniere, BP 32229, 44322 Nantes Cedex 3 (France); Boujtita, M. [Universite de Nantes, Faculte des Sciences et des Techniques, Chimie et Interdisciplinarite: Synthese, Analyse, Modelisation (CEISAM), UMR CNRS no 6230, 2, rue de la Houssiniere, BP 92208, 44322 NANTES Cedex 3 (France)], E-mail: mohammed.boujtita@univ-nantes.fr

    2009-04-15

    Radiofrequency argon plasma was used for screen-printed carbon electrodes (SPCE) surface treatment. The cyclic voltammetry of ferri/ferrocyanide as redox couple showed a remarkable improvement of the electrochemical reactivity of the SPCE after the plasma treatment. The effect of the plasma growth conditions on the efficiency of the treatment procedure was evaluated in term of electrochemical reactivity of the SPCE surface. The electrochemical study showed that the electrochemical reactivity of the treated electrodes was strongly dependant on radiofrequency power, treatment time and argon gas pressure. X-ray photoelectron spectroscopy (XPS) analysis showed a considerable evolution on the surface chemistry of the treated electrodes. Our results clearly showed that the argon plasma treatment induces a significant increase in the C{sub sp2}/C{sub sp3} ratio. The scanning electron micrograph (SEM) also showed a drastic change on the surface morphology of the treated SPCEs.

  13. Analysis of the expanding thermal argon-oxygen plasma gas phase

    NARCIS (Netherlands)

    Hest, van M.F.A.M.; Haartsen, J.R.; Weert, van M.H.M.; Schram, D.C.; Sanden, van de M.C.M.

    2003-01-01

    An expanding thermal argon plasma into which oxygen is injected has been analyzed by means of Langmuir and Pitot probe measurements. Information is obtained on the ion d. profile and the flow pattern in the downstream plasma. A combination of Langmuir and Pitot probe measurements provide information

  14. Polydiagnostic calibration performed on a low pressure surface wave sustained argon plasma

    NARCIS (Netherlands)

    Vries, de N.; Palomares, J.M.; Iordanova, E.I.; Veldhuizen, van E.M.; Mullen, van der J.J.A.M.

    2008-01-01

    The electron density and electron temperature of a low pressure surface wave sustained argon plasma have been determined using passive and active (laser) spectroscopic methods simultaneously. In this way the validity of the various techniques is established while the plasma properties are determined

  15. Confluence or independence of microwave plasma bullets in atmospheric argon plasma jet plumes

    Science.gov (United States)

    Li, Ping; Chen, Zhaoquan; Mu, Haibao; Xu, Guimin; Yao, Congwei; Sun, Anbang; Zhou, Yuming; Zhang, Guanjun

    2018-03-01

    Plasma bullet is the formation and propagation of a guided ionization wave (streamer), normally generated in atmospheric pressure plasma jet (APPJ). In most cases, only an ionization front produces in a dielectric tube. The present study shows that two or three ionization fronts can be generated in a single quartz tube by using a microwave coaxial resonator. The argon APPJ plumes with a maximum length of 170 mm can be driven by continuous microwaves or microwave pulses. When the input power is higher than 90 W, two or three ionization fronts propagate independently at first; thereafter, they confluence to form a central plasma jet plume. On the other hand, the plasma bullets move independently as the lower input power is applied. For pulsed microwave discharges, the discharge images captured by a fast camera show the ionization process in detail. Another interesting finding is that the strongest lightening plasma jet plumes always appear at the shrinking phase. Both the discharge images and electromagnetic simulations suggest that the confluence or independent propagation of plasma bullets is resonantly excited by the local enhanced electric fields, in terms of wave modes of traveling surface plasmon polaritons.

  16. coagulation factors level in fresh frozen plasma in rwanda

    African Journals Online (AJOL)

    2014-02-02

    Feb 2, 2014 ... Setting: Jomo Kenyatta University of Agriculture and Technology in ... a major role in blood coagulation process. ... storage conditions and quality control prior to clinical ... instrumentation Laboratory Company USA made in.

  17. Contribution to the evaluation of diffusion coefficients in plasmas containing argon and fluorine

    International Nuclear Information System (INIS)

    Novakovic, N V

    2006-01-01

    The theoretical values of the numerical evaluation of the electron and ion diffusion coefficients in plasmas from mixtures of argon and fluorine are presented. The temperature dependence of the diffusion coefficients for low-pressure (from 0.1 to 1.0 kPa) and low-temperature (from 500 to 5000 K) argon plasmas with 20% and 30% of added fluorine are investigated. These values are results of the applications of the specific numerical model to the evaluation plasma composition and transport coefficients in argon plasma with fluorine as additive. It is assumed that the system is kept under constant pressure and that a corresponding state of local thermodynamical equilibrium (LTE) is attained. Since the LTE can be assumed, a Maxwellian electron distribution function will be adopted. The hypothesis of LTE, which is commonly used in most of the numerical evaluations, is analysed with the modified Debye radius r D *. The binary electron and ion diffusion coefficients are calculated with the equilibrium plasma composition and with the collision frequencies. Strictly speaking, Maxwellian distribution function (in the state LTE) is not valid for low pressure, but in this case with the aid of the modified Debye radius, a Maxwellian f e M is assumed correctly. It is shown that the electron diffusion coefficients are about four orders of magnitude larger than the corresponding overall diffusion coefficients of ions. Both diffusion coefficients are lower in argon plasma with 30% than with 20% of fluorine additives, in the whole temperature range examined

  18. The calculation of electron density of the non-ideal argon plasma

    International Nuclear Information System (INIS)

    Jiang Ming; Cheng Xinlu; Yang Xiangdong

    2004-01-01

    By the screened hydrogenic model, the paper calculates the electron densities of shock-generated argon plasma with temperature T∼2.0 eV and density of plasma ρ∼0.01 g/cm 3 -0.49 g/cm 3 , and studies the influence on electron density caused by interparticle interaction at the different temperature and density of plasma. (author)

  19. Investigation of supercapacitors with carbon electrodes obtained from argon-acetylene arc plasma

    OpenAIRE

    Kavaliauskas, Žydrūnas

    2010-01-01

    The dissertation examines topics related to the formation of supercapacitors using plasma technology and their analysis. Plasma spray technology was used to form supercapacitors electrodes. Carbon was deposited on stainless steel surface using the atmospheric pressure argon-acetylene plasma. The deposition of nickel oxide on the surface of carbon electrodes was made using magnetron sputtering method. The influence of acetylene amount to the supercapacitors electrodes and the electrical charac...

  20. Mechanism of the immobilization of surfactants on polymeric surfaces by means of an argon plasma treatment: Influence of UV radiation

    NARCIS (Netherlands)

    Lens, J.P.; Spaay, B.; Terlingen, J.G.A.; Engbers, G.H.M.; Feijen, Jan

    1999-01-01

    The mechanism of the immobilization of the surfactant sodium 10-undecenoate (C11(:)) on poly(ethylene) (PE) by means of an argon plasma treatment has been investigated. In particular, the influence of the vacuum ultraviolet (UV) radiation emitted by the argon plasma on the immobilization was

  1. Surface modification of fluorosilicone acrylate RGP contact lens via low-temperature argon plasma

    International Nuclear Information System (INIS)

    Yin Shiheng; Wang Yingjun; Ren Li; Zhao Lianna; Kuang Tongchun; Chen Hao; Qu Jia

    2008-01-01

    A fluorosilicone acrylate rigid gas permeable (RGP) contact lens was modified via argon plasma to improve surface hydrophilicity and resistance to protein deposition. The influence of plasma treatment on surface chemical structure, hydrophilicity and morphology of RGP lens was investigated by X-ray photoelectron spectrometer (XPS), contact angle measurements and scanning electron microscope (SEM), respectively. The contact angle results showed that the hydrophilicity of the contact lens was improved after plasma treatment. XPS results indicated that the incorporation of oxygen-containing groups on surface and the transformation of silicone into hydrophilic silicate after plasma treatment are the main reasons for the surface hydrophilicity improvement. SEM results showed that argon plasma with higher power could lead to surface etching

  2. Enhanced coagulation activation in preeclampsia: the role of APC resistance, microparticles and other plasma constituents

    NARCIS (Netherlands)

    VanWijk, Marja J.; Boer, Kees; Berckmans, René J.; Meijers, Joost C. M.; van der Post, Joris A. M.; Sturk, Augueste; VanBavel, Ed; Nieuwland, Rienk

    2002-01-01

    Coagulation activation in pregnancy is further enhanced in preeclampsia. We investigated whether this results from increased thrombin generation by the plasma itself or its cell-derived microparticles. Plasma samples were obtained from preeclamptic, normal pregnant and nonpregnant women (each n =

  3. Argon plasma sintering of inkjet printed silver tracks on polymer substrates

    NARCIS (Netherlands)

    Reinhold, I.; Hendriks, C.E.; Eckardt, R.; Kranenburg, J.M.; Perelaer, J.; Baumann, R.; Schubert, U.S.

    2009-01-01

    An alternative and selective sintering method for the fabrication of conductive silver tracks on common polymer substrates is presented, by exposure to low-pressure argon plasma. Inkjet printing has been used to pattern a silver nanoparticle ink. This resulted in conductive features with a

  4. Electrical aspects of argon micro-cell plasma with applications in bio-medical technology

    NARCIS (Netherlands)

    Horiuchi, Y.; Dijk, van J.; Makabe, T.

    2003-01-01

    Argon micro-cell plasma (MCP) is believed to be a viable tool for performing micro-surgery. The non-thermal nature of the discharge allows an effective treatment of pathological tissue without causing thermal damage to its surroundings. This bio-medical application imposes a number of design

  5. Thermodynamic diagrams for high temperature plasmas of air, air-carbon, carbon-hydrogen mixtures, and argon

    CERN Document Server

    Kroepelin, H; Hoffmann, K-U

    2013-01-01

    Thermodynamic Diagrams for High Temperature Plasmas of Air, Air-Carbon, Carbon-Hydrogen Mixtures, and Argon provides information relating to the properties of equilibrium gas plasmas formed from hydrocarbons, from air without argon, from pure argon, and from mixtures of air and carbon at various compositions, temperatures and pressures. The data are presented in graphical rather than tabular form to provide a clearer picture of the plasma processes investigated. This book is composed of four chapters, and begins with the introduction to the characteristics of plasmas, with emphasis on their th

  6. Hall effect in non-ideal plasma of argon and xenon

    International Nuclear Information System (INIS)

    Shilkin, N.S.; Dudin, S.V.; Gryaznov, V.K.; Mintsev, V.B.; Fortov, V.E.

    2003-01-01

    The first data on the measurement of the electron concentration (10 16 -10 20 cm -3 ) of the low-temperature (0.5-1 eV) non-ideal (0.01 -6 -10 -1 ) inert gases plasma are presented. The measurements of the Hall constant and electric conductivity in the non-ideal partially ionized plasma of argon and xenon are carried out through the sounding methods. The plasma generation was accomplished behind the shock waves front through the linear explosive generators. The obtained results are compared with a number of the plasma models [ru

  7. PIC Modeling of Argon Plasma Flow in MNX

    Science.gov (United States)

    Cohen, Samuel; Sefkow, Adam

    2007-11-01

    A linear helicon-heated plasma device - the Magnetic Nozzle Experiment (MNX) at the Princeton Plasma Physics Laboratory - is used for studies of the formation of strong electrostatic double layers near mechanical and magnetic apertures and the acceleration of plasma ions into supersonic directed beams. In order to characterize the role of the aperture and its involvement with ion acceleration, detailed particle-in-cell simulations are employed to study the effects of the surrounding boundary geometry on the plasma dynamics near the aperture region, within which the transition from a collisional to collisionless regime occurs. The presence of a small superthermal electron population is examined, and the model includes a background neutral population which can be ionized by energetic electrons. By self-consistently evaluating the temporal evolution of the plasma in the vicinity of the aperture, the formation mechanism of the double layer is investigated.

  8. Effect of argon plasma treatment on the output performance of triboelectric nanogenerator

    Energy Technology Data Exchange (ETDEWEB)

    Cheng, Guang-Gui, E-mail: ggcheng@ujs.edu.cn [Research Center of Micro/Nano Science and Technology, Jiangsu University, Zhenjiang (China); Jiangsu Collaborative Innovation Center of Photovoltaic Science and Engineering, Changzhou University, Changzhou (China); Jiang, Shi-Yu; Li, Kai [Research Center of Micro/Nano Science and Technology, Jiangsu University, Zhenjiang (China); Zhang, Zhong-Qiang [Research Center of Micro/Nano Science and Technology, Jiangsu University, Zhenjiang (China); Jiangsu Collaborative Innovation Center of Photovoltaic Science and Engineering, Changzhou University, Changzhou (China); Wang, Ying; Yuan, Ning-Yi [Jiangsu Collaborative Innovation Center of Photovoltaic Science and Engineering, Changzhou University, Changzhou (China); Ding, Jian-Ning, E-mail: dingjn@ujs.edu.cn [Research Center of Micro/Nano Science and Technology, Jiangsu University, Zhenjiang (China); Jiangsu Collaborative Innovation Center of Photovoltaic Science and Engineering, Changzhou University, Changzhou (China); Zhang, Wei [Research Center of Micro/Nano Science and Technology, Jiangsu University, Zhenjiang (China)

    2017-08-01

    Highlights: • Two different kinds of PDMS films were prepared by spin-coated. • The PDMS surface was plasma treated with different power and time. • The output performance of TENG was significantly enhanced by plasma treatment. • Plasma treatment effect has time-efficient, the output declines with store time. - Abstract: Physical and chemical properties of the polymer surface play great roles in the output performance of triboelectric nanogenerator (TENG). Specific texture on the surface of polymer can enlarge the contact area and enhance the power output performance of TENG. In this paper, polydimethylsiloxane (PDMS) films with smooth and micro pillar arrays on the surface were prepared respectively. The surfaces were treated by argon plasma before testing their output performance. By changing treatment parameters such as treating time and plasma power, surfaces with different roughness and their relationship were achieved. The electrical output performances of the assembled TENG for each specimen showed that argon plasma treatment has a significant etching effect on the PDMS surface and greatly strengthen its output performance. The average surface roughness of PDMS film increases with the etching time from 5 mins to 15 mins when the argon plasma power is 60 W. Nevertheless, the average surface roughness is inversely proportional to the treatment time for the power of 90W. When treated with 90 W and 5 mins, many uniform micro pillars appeared on the both PDMS surface, and the output performance of the TENG for plasma treated smooth surface is 2.6 times larger than that before treatment. The output voltage increases from 42 V to 72 V, and the short circuit current increases from 4.2 μA to 8.3 μA after plasma treatment of the micro pillar array surface. However, this plasma treatment has time-efficient due to the hydrophobic recovery property of Ar plasma treated PDMS surface, both output voltage and short circuit current decrease significantly after 3

  9. Mass spectrometric evidence for suprathermal ionization in an inductively coupled argon plasma

    International Nuclear Information System (INIS)

    Houk, R.S.; Svec, H.J.; Fassel, V.A.

    1981-01-01

    Mass spectra have been obtained of species in the axial channel of an inductively coupled argon plasma by extracting ions from the inductively coupled plasma into a vacuum system housing a quadrupole mass spectrometer. Ionization temperatures (T/sub ion/) are obtained from relative count rates of m/z-resolved ions according to two general types of ionization equilibrium considerations: (a) the radio of doubly/singly charged ions of the same element, and (b) the ratio of singly charged ions from two elements of different ionization energy. The T/sub ion/ values derived from measurement of Ar +2 /Ar + , Ba +2 /Ba + , Sr +2 /Sr + , and Cd + /I + are all greater than those expected from excitation temperatures measured by other workers. The latter three values for T/sub ion/ are in reasonable agreement with values obtained by optical spectrometry for a variety of argon inductively coupled plasmas

  10. A simplified model for computing equation of state of argon plasma

    International Nuclear Information System (INIS)

    Wang Caixia; Tian Yangmeng

    2006-01-01

    The paper present a simplified new model of computing equation of state and ionization degree of Argon plasma, which based on Thomas-Fermi (TF) statistical model: the authors fitted the numerical results of the ionization potential calculated by Thomas-Fermi statistical model and gained the analytical function of the potential versus the degree of ionization, then calculated the ionization potential and the average degree of ionization for Argon versus temperature and density in local thermal equilibrium case at 10-1000 eV. The results calculated of this simplified model are basically in agreement with several sets of theory data and experimental data. This simplified model can be used to calculation of the equation of state of plasmas mixture and is expected to have a more wide use in the field of EML technology involving the strongly ionized plasmas. (authors)

  11. Introduction of argon beam coagulation functionality to robotic procedures using the ABC D-Flex probe: equivalency to an existing laparoscopic instrument

    Science.gov (United States)

    Merchel, Renée. A.; Barnes, Kelli S.; Taylor, Kenneth D.

    2015-03-01

    INTRODUCTION: The ABC® D-Flex Probe utilizes argon beam coagulation (ABC) technology to achieve hemostasis during minimally invasive surgery. A handle on the probe allows for integration with robotic surgical systems and introduces ABC to the robotic toolbox. To better understand the utility of D-Flex, this study compares the performance of the D-Flex probe to an existing ABC laparoscopic probe through ex vivo tissue analysis. METHODS: Comparisons were performed to determine the effect of four parameters: ABC device, tissue type, activation duration, and distance from tissue. Ten ABC D-Flex probes were used to create 30 burn samples for each comparison. Ex vivo bovine liver and porcine muscle were used as tissue models. The area and depth of each burn was measured using a light microscope. The resulting dimensional data was used to correlate tissue effect with each variable. RESULTS: D-Flex created burns which were smaller in surface area than the laparoscopic probe at all power levels. Additionally, D-Flex achieved thermal penetration levels equivalent to the laparoscopic probe. CONCLUSION: D-Flex implements a small 7F geometry which creates a more focused beam. When used with robotic precision, quick localized superficial hemostasis can be achieved with minimal collateral damage. Additionally, D-Flex achieved equivalent thermal penetration levels at lower power and argon flow-rate settings than the laparoscopic probe.

  12. Spatio-temporal dynamics of a pulsed microwave argon plasma: ignition and afterglow

    International Nuclear Information System (INIS)

    Carbone, Emile; Sadeghi, Nader; Vos, Erik; Hübner, Simon; Van Veldhuizen, Eddie; Van Dijk, Jan; Nijdam, Sander; Kroesen, Gerrit

    2015-01-01

    In this paper, a detailed investigation of the spatio-temporal dynamics of a pulsed microwave plasma is presented. The plasma is ignited inside a dielectric tube in a repetitively pulsed regime at pressures ranging from 1 up to 100 mbar with pulse repetition frequencies from 200 Hz up to 500 kHz. Various diagnostic techniques are employed to obtain the main plasma parameters both spatially and with high temporal resolution. Thomson scattering is used to obtain the electron density and mean electron energy at fixed positions in the dielectric tube. The temporal evolution of the two resonant and two metastable argon 4s states are measured by laser diode absorption spectroscopy. Nanosecond time-resolved imaging of the discharge allows us to follow the spatio-temporal evolution of the discharge with high temporal and spatial resolution. Finally, the temporal evolution of argon 4p and higher states is measured by optical emission spectroscopy. The combination of these various diagnostics techniques gives deeper insight on the plasma dynamics during pulsed microwave plasma operation from low to high pressure regimes. The effects of the pulse repetition frequency on the plasma ignition dynamics are discussed and the plasma-off time is found to be the relevant parameter for the observed ignition modes. Depending on the delay between two plasma pulses, the dynamics of the ionization front are found to be changing dramatically. This is also reflected in the dynamics of the electron density and temperature and argon line emission from the plasma. On the other hand, the (quasi) steady state properties of the plasma are found to depend only weakly on the pulse repetition frequency and the afterglow kinetics present an uniform spatio-temporal behavior. However, compared to continuous operation, the time-averaged metastable and resonant state 4s densities are found to be significantly larger around a few kHz pulsing frequency. (paper)

  13. Nanoparticle formation in a low pressure argon/aniline RF plasma

    Science.gov (United States)

    Pattyn, C.; Kovacevic, E.; Hussain, S.; Dias, A.; Lecas, T.; Berndt, J.

    2018-01-01

    The formation of nanoparticles in low temperature plasmas is of high importance for different fields: from astrophysics to microelectronics. The plasma based synthesis of nanoparticles is a complex multi-scale process that involves a great variety of different species and comprises timescales ranging from milliseconds to several minutes. This contribution focuses on the synthesis of nanoparticles in a low temperature, low pressure capacitively coupled plasma containing mixtures of argon and aniline. Aniline is commonly used for the production of polyaniline, a material that belongs to the family of conductive polymers, which has attracted increasing interest in the last few years due to the large number of potential applications. The nanoparticles which are formed in the plasma volume and levitate there due to the collection of negative charges are investigated in this contribution by means of in-situ FTIR spectroscopy. In addition, the plasma is analyzed by means of plasma (ion) mass spectroscopy. The experiments reveal the possibility to synthesize nanoparticles both in continuous wave and in pulsed discharges. The formation of particles in the plasma volume can be suppressed by pulsing the plasma in a specific frequency range. The in-situ FTIR analysis also reveals the influence of the argon plasma on the characteristics of the nanoparticles.

  14. Analysis of the expanding thermal argon-oxygen plasma gas phase

    International Nuclear Information System (INIS)

    Hest, M F A M van; Haartsen, J R; Weert, M H M van; Schram, D C; Sanden, M C M van de

    2003-01-01

    An expanding thermal argon plasma into which oxygen is injected has been analysed by means of Langmuir and Pitot probe measurements. Information is obtained on the ion density profile and the flow pattern in the downstream plasma. A combination of Langmuir and Pitot probe measurements provide information on the total ion flux generated by the plasma source (cascaded arc). It has been found that the ion diffusion is mainly determined by the background pressure in the expansion vessel and the arc current. The ion density is determined by the total power input into the plasma as well as the gas flow in the plasma source. There is an optimum in the power transfer used for ionization from plasma source to the feed gas. Interaction of oxygen with the plasma results in a decrease in the argon ion density and the plasma beam radius. The recirculation pattern of the downstream plasma has been investigated experimentally using the Pitot probe. Due to the low downstream pressure (10-30 Pa), the conventional compressible Pitot probe theory no longer applies. It is concluded that viscous effects start to play an important role at these low pressures and should be taken into account in the analysis of the Pitot probe measurements

  15. Photoionized argon plasmas induced with intense soft x-ray and extreme ultraviolet pulses

    Czech Academy of Sciences Publication Activity Database

    Bartnik, A.; Wachulak, P.; Fok, T.; Węgrzyński, L.; Fiedorowicz, H.; Skrzeczanowski, W.; Pisarczyk, T.; Chodukowski, T.; Kalinowska, Z.; Dudžák, Roman; Dostál, Jan; Krouský, Eduard; Skála, Jiří; Ullschmied, Jiří; Hřebíček, Jan; Medřík, Tomáš

    2016-01-01

    Roč. 58, č. 1 (2016), č. článku 014009. ISSN 0741-3335 R&D Projects: GA MŠk LM2010014 EU Projects: European Commission(XE) 284464 - LASERLAB-EUROPE Institutional support: RVO:61389021 ; RVO:68378271 Keywords : laser-plasma * plasma radiation * photoionization * Argon plasma * Nd:YAG laser * PALS iodine laser Subject RIV: BL - Plasma and Gas Discharge Physics; BL - Plasma and Gas Discharge Physics (FZU-D) OBOR OECD: Fluids and plasma physics (including surface physics); Fluids and plasma physics (including surface physics) (FZU-D) Impact factor: 2.392, year: 2016 http://iopscience.iop.org/article/10.1088/0741-3335/58/1/014009

  16. XUV radiation from gaseous nitrogen and argon target laser plasmas

    Czech Academy of Sciences Publication Activity Database

    Vrba, Pavel; Vrbová, M.; Brůža, P.; Pánek, D.; Krejčí, F.; Kroupa, M.; Jakůbek, J.

    2012-01-01

    Roč. 370, č. 1 (2012), s. 012049 ISSN 1742-6588. [Latin American Workshop on Plasma Physics (LAWPP 2011)/14/. Mar del Plata, 20.11.2011-25.11.2011] R&D Projects: GA MŠk LA08024; GA MŠk(CZ) LC528 Institutional research plan: CEZ:AV0Z20430508 Keywords : Laser plasma source of XUV radiation in water window range * RHMD Z* engine code Subject RIV: BH - Optics, Masers, Lasers http://iopscience.iop.org/1742-6596/370/1/012049/pdf/1742-6596_370_1_012049.pdf

  17. Coagulation parameters as a guide for fresh frozen plasma transfusion practice: A tertiary hospital experience

    Directory of Open Access Journals (Sweden)

    Wan Haslindawani W

    2010-01-01

    Full Text Available Introduction: The appropriate use of blood and blood products means the transfusion of safe blood products only to treat a condition leading to significant morbidity or mortality, which cannot be prevented or managed effectively by other means. The safety and effectiveness of transfusion depend on the appropriate clinical use of blood and blood products. This study was conducted to review the practice of fresh frozen plasma usage (FFP for transfusion, based on the coagulation profile, requested by various departments in the Hospital Universiti Sains Malaysia (HUSM. Methodology: A retrospective review of blood bank records and coagulation profile results of the patients given FFP from October to December 2006, in Hospital USM was undertaken. The criteria set by the College of American Pathologists in 1994, were used as the guidelines. Results: One thousand six hundred and ninety-eight units of FFP were used during this study period. Only 806 (47.47% FFP units were deemed appropriate. 20.38% were based on studies without any coagulation tests prior to transfusion and 21.13% were transfused for mild prolongation of coagulation test results. About 6.41% requested FFP in the setting of normal coagulation results. Conclusion: Our results showed that a significant proportion of the FFP transfusion was not guided by the coagulation profile. We recommend that a continuous education on FFP transfusion may help to guide the appropriate request for FFP.

  18. The influence of methane/argon plasma composition on the formation of the hydrogenated amorphous carbon films

    International Nuclear Information System (INIS)

    Chen, Hsin-Hung; Liao, Jiunn-Der; Weng, Chih-Chiang; Hsieh, Jui-Fu; Chang, Chia-Wei; Lin, Chao-Hsien; Cho, Ting-Pin

    2011-01-01

    The quality of the a-C:H films was particularly correlated with the mixed ratio of methane/argon plasma. For a constant supply of energy and flowing rate, the optical emission from H α intensity linearly increased with the addition of methane in argon plasma, while that from intensities of radiation of diatmoic radicals (CH*and C 2 *) exponentially decreased. For the a-C:H films, the added methane in argon plasma tended to raise the quantity of hydrogenated carbon or sp 3 C-H structure, which exponentially decreased the nano-hardness and friction coefficient of the films. In contrast, the electric resistance of the films enlarged dramatically with the increase of the methane content in argon plasma. It is therefore advantageous to balance the mechanical properties and electrical resistance of the a-C:H film by adjusting plasma composition in the course of the film-growing process.

  19. Nonlinear phenomena in the interaction of microwaves with the low-temperature argon plasma flux

    International Nuclear Information System (INIS)

    Armand, N.A.; Lisitskaya, A.A.; Rogashkov, S.A.; Rogashkova, A.I.; Chmil', A.I.; Shustin, E.G.

    1982-01-01

    Theoretical and experimental investigations of nonlinear effects arising during the passing of SHF waves across an argon plasma jet flowing from an arc plasmatron have been carried on. It is shown that under conditions of the radiowave propagation through low temperature plasma moving across the direction of the wave propagation modes of both the wave self-focusing and its nonlinear asymmetrical refaction can be accomplished. The effect of the formation and propagation of the additional ionization region in a microwave flow initiated with plasma independently produced in the region of the maximum amplitude of the SHF field has been experimentally discovered [ru

  20. Surface modification of ultra-high molecular weight polyethylene (UHMWPE) by argon plasma

    International Nuclear Information System (INIS)

    Liu Hengjun; Pei Yanan; Xie Dong; Deng Xingrui; Leng, Y.X.; Jin Yong; Huang Nan

    2010-01-01

    In this work, argon (Ar) plasma generated by microwave electron cyclotron resonance (MWECR) has been used to modify the UHMWPE in order to increase the wear resistance. The results showed that the wettability, anti-scratch and wear resistance of UHMWPE treated by the Ar plasma had been improved, comparing with native UHMWPE. The FTIR and XPS spectra indicated the improvement of wettability should come from the oxygen based functional groups generated on the surface of UHMWPE. The improvement of anti-scratch and wear resistance may come from the enhancement of crosslinking of UHMWPE by Ar plasma treatment.

  1. Heat flux characteristics in an atmospheric double arc argon plasma jet

    International Nuclear Information System (INIS)

    Tu Xin; Yu Liang; Yan Jianhua; Cen Kefa; Cheron, Bruno

    2008-01-01

    In this study, the axial evolution of heat flux excited by a double arc argon plasma jet impinging on a flat plate is determined, while the nonstationary behavior of the heat flux is investigated by combined means of the fast Fourier transform, Wigner distribution, and short-time Fourier transform. Two frequency groups (<1 and 2-10 kHz) are identified in both the Fourier spectrum and the time-frequency distributions, which suggest that the nature of fluctuations in the heat flux is strongly associated with the dynamic behavior of the plasma arc and the engulfment of ambient air into different plasma jet regions

  2. Role of recombination, ionization, diffusion and convection in a decaying argon plasma

    International Nuclear Information System (INIS)

    Gleizes, A.

    1981-01-01

    A theoretical study of a decaying argon arc plasma, at atmospheric pressure, has been performed to determine the plasma state during the decay. The method is based on the transport equations combined with the knowledge of the electron density previously measured. The comparison between calculated and experimental results allows the analysis of the main processes responsible for the particle density evolutions. It is shown that departures from LTE are important and that thermal equilibrium is not even achieved in the plasma. This result is due to the role of elastic collisions between electrons and heavy particles in the electron energy balance. (orig.)

  3. Influence of argon plasma treatment on polyethersulphone surface

    Indian Academy of Sciences (India)

    N L Singh1 S M Pelagade1 R S Rane2 S Mukherjee2 U P Deshpande3 V Ganeshan3 T Shripathi3. Department of Physics, M.S. University of Baroda, Vadodara 390 002, India; FCIPT, Institute for Plasma Research, Gandhinagar 382 044, India; UGC-DAE-CSR, University Campus, Khandawa Road, Indore 452 017, India ...

  4. Generation of uniform atmospheric pressure argon glow plasma by ...

    Indian Academy of Sciences (India)

    The electron temperature and electron density of the plasma are determined ... Dielectric barrier discharge (DBD) and APGD are the subjects of research for the last ... The gap between the electrodes can be varied from 0.5 mm to 2 mm and Ar ...

  5. Inductively coupled plasma--atomic emission spectroscopy: an evaluation of the use of nitrogen--argon admixtures as plasma discharge atmospheres

    International Nuclear Information System (INIS)

    Zalewski, J.C.

    1979-01-01

    The effects of the use of nitrogen in either the plasma coolant or aerosol carrier gas flows on the physical and spectrochemical properties of the inductively coupled plasma (ICP) were examined. While the plasma operated with nitrogen in the coolant flow exhibited a stability comparable to that of the argon plasma, the use of nitrogen in the aerosol carrier gas flow resulted in a plasma that was less stable. The detection limits obtained for the three plasmas exhibited a similar trend. In addition, the use of nitrogen--argon admixtures in the plasma coolant gas flow yielded an increase in both the net analyte and the background emission intensities when the corresponding argon and nitrogen--argon plasmas were operated under various conditions. Furthermore, the effect of aluminum on the Ca II (393.4 nm) spectral line was reported for the 1000/1 Al/Ca molar ratio. At an observation height of 15 mm, the signal depressions were 4 and 14% for the nitrogen--argon and the argon plasmas, respectively. The above experimental evidence suggested that the operation of the ICP with an Ar--N 2 coolant gas might be hotter than the argon plasma currently in use in this laboratory. The demountable plasma torch designed in collaboration with K. Olson yielded detection limits for 15 elements and 19 spectral lines that were approximately within a factor of two of those obtained with the torch of fused quartz design. The design also appeared to offer a more readily initiated plasma discharge. The experimental evidence presented supports the utilization of nitrogen--argon admixtures in the plasma coolant gas flow as alternate discharge atmospheres for inductively coupled plasma--atomic emission spectroscopy. In contrast, the experimental evidence shows that there is a deterioration in both physical and spectrochemical properties of plasmas operated with a nitrogen aerosol carrier gas

  6. Transport and turbulence in a magnetized argon plasma

    International Nuclear Information System (INIS)

    Vogels, J.M.M.J.

    1984-01-01

    Three aspects of the longitudinal motion of ionized and neutral particles in a hollow cathode arc are investigated. The longitudinal plasma momentum balance of the column has been investigated, we have studied the momentum balance in relation to turbulence and we have investigated the source properties of the cathode. The study of the plasma momentum balance contains two aspects: (1) to collect experimental data on ion drift velocities and temperatures with Fabry-Perot interferometry, on electron densities and temperatures with Thomson scattering or optical spectroscopy and on neutral densities with a collisional radiative model combined with the ion energy balance; (2) to check the (classical) theory of the momentum balance with these data. The coupling between these aspects has been investigated and found to be in good agreement. (Auth.)

  7. Numerical Analysis of Amirkabir Plasma Focus (APF) Device for Neon and Argon Gases

    Science.gov (United States)

    Niknam Sharak, M.; Goudarzi, S.; Raeisdana, A.; Jafarabadi, M.

    2013-04-01

    In this paper the experimental results in different working conditions in Amirkabir Plasma Focus (APF) Device have been compared with the numerical results of a two-dimensional simulation code based on Lee's model. The experiments were done with pure Neon and Argon as operating gases over a wide range of working conditions (gas pressures and discharge voltages). It is observed that by a proper choice for values of the efficiency factors, comparison between numerical and experimental results shows a good agreement.

  8. Electrical conductivity and charge carrier screening in weakly non-ideal argon plasmas

    International Nuclear Information System (INIS)

    Guenther, K.; Lang, S.; Radtke, R.

    1983-01-01

    A pulsed argon discharge as a stable source of weakly non-ideal plasmas is described in connection with the diagnostic necessities for conductivity measurements. The parameters overlap the range for stationary arcs and allow comparison with measurements in cascade arcs. The measured conductivities are explained using the binary collision model considering collisions with neutrals, excited atoms, and ions. A relation between the screening parameter and non-ideality is proposed which should be valid for all elements. (author)

  9. Electrical conductivity and charge carrier screening in weakly non-ideal argon plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Guenther, K; Lang, S; Radtke, R [Akademie der Wissenschaften der DDR, Jena. Zentralinstitut fuer Elektronenphysik

    1983-07-14

    A pulsed argon discharge as a stable source of weakly non-ideal plasmas is described in connection with the diagnostic necessities for conductivity measurements. The parameters overlap the range for stationary arcs and allow comparison with measurements in cascade arcs. The measured conductivities are explained using the binary collision model considering collisions with neutrals, excited atoms, and ions. A relation between the screening parameter and non-ideality is proposed which should be valid for all elements.

  10. The measurement of argon metastable atoms in the barrier discharge plasma

    Science.gov (United States)

    Ghildina, Anna R.; Mikheyev, Pavel Anatolyevich; Chernyshov, Aleksandr Konstantinovich; Lunev, Nikolai Nikolaevich; Azyazov, Valeriy Nikolaevich

    2018-04-01

    The mandatory condition for efficient operation of an optically-pumped all-rare-gas laser (OPRGL) is the presence of rare gas metastable atoms in the discharge plasma with number density of the order of 1012-1013 cm-3. This requirement mainly depends on the choice of a discharge system. In this study the number density values of argon metastable atoms were obtained in the condition of the dielectric-barrier discharge (DBD) at an atmospheric pressure.

  11. Argon plasma jet continuum emission investigation by using different spectroscopic methods

    International Nuclear Information System (INIS)

    Dgheim, J

    2007-01-01

    Radiation and temperature fields of the continuum field are determined by using different spectroscopic methods based on the spectral emission of an argon plasma jet. An interferential filter of bandwidth 2.714 nm centred at a wavelength of 633 nm is used to observe only the continuum emission and to eliminate the self-absorption phenomenon. An optical multichannel analyser (OMA) of an MOS detector is used to measure argon plasma jet volumetric emissivity under atmospheric pressure and high temperatures. An emission spectroscopic method is used to measure the Stark broadening of the hydrogen line H β and to determine the electron density. The local thermodynamic equilibrium is established and its limit is stated. The local electron temperature is determined by two methods (the continuum emission relation and the LTE relations), and the total Biberman factor is measured. The results given by the OMA are compared with those given by the imagery method. At a given wavelength, the Biberman factor, which depends on the electron temperature and the electron density, may serve as an indicator to show where the LTE prevails along the argon plasma jet core length

  12. Enhanced Field Emission from Argon Plasma-Treated Ultra-sharp α-Fe2O3Nanoflakes

    Directory of Open Access Journals (Sweden)

    Zhang JX

    2009-01-01

    Full Text Available Abstract Hematite nanoflakes have been synthesized by a simple heat oxide method and further treated by Argon plasmas. The effects of Argon plasma on the morphology and crystal structures of nanoflakes were investigated. Significant enhancement of field-induced electron emission from the plasma-treated nanoflakes was observed. The transmission electron microscopy investigation shows that the plasma treatment effectively removes amorphous coating and creates plenty of sub-tips at the surface of the nanoflakes, which are believed to contribute the enhancement of emission. This work suggests that plasma treatment technique could be a direct means to improve field-emission properties of nanostructures.

  13. An investigation of non-equilibrium effects in thermal argon plasmas

    International Nuclear Information System (INIS)

    Rosado, R.J.

    1981-01-01

    This thesis deals with the study of the validity of the assumption of Local Thermal Equilibrium (LTE) in the description of the parameters of a thermal argon plasma. The aim is twofold. As the studied plasma is close to, but not completely in equilibrium, the author first attempts to obtain a simple description of the plasma in terms of an LTE model in which suitable corrections for the deviations of the plasma parameters from their LTE values is introduced. To this end the plasma parameters are studied by means of a diagnostic method in which the assumption of LTE is not made. The evaluation of the usefulness of this method is the second aim of this thesis. (Auth.)

  14. Deviation from local thermodynamic equilibrium in a cesium-seeded argon plasma

    International Nuclear Information System (INIS)

    Stefanov, B.; Zarkova, L.

    1985-11-01

    The possibility of deviations from local thermodynamic equilibrium of a cesium seeded argon plasma has been analyzed. A four level model of cesium has been employed. Overpopulations of the ground state and the first excited state as well as the corresponding reduction of the electron density are calculated for cylindrical discharge structures by solving stationary rate equations. Numerical results are presented. These results indicate that in a large regime of plasma conditions the LTE assumption is valid for electron temperatures larger than 3000 K. (orig.)

  15. Plasma breakdown in a capacitively-coupled radiofrequency argon discharge

    Science.gov (United States)

    Smith, H. B.; Charles, C.; Boswell, R. W.

    1998-10-01

    Low pressure, capacitively-coupled rf discharges are widely used in research and commercial ventures. Understanding of the non-equilibrium processes which occur in these discharges during breakdown is of interest, both for industrial applications and for a deeper understanding of fundamental plasma behaviour. The voltage required to breakdown the discharge V_brk has long been known to be a strong function of the product of the neutral gas pressure and the electrode seperation (pd). This paper investigates the dependence of V_brk on pd in rf systems using experimental, computational and analytic techniques. Experimental measurements of V_brk are made for pressures in the range 1 -- 500 mTorr and electrode separations of 2 -- 20 cm. A Paschen-style curve for breakdown in rf systems is developed which has the minimum breakdown voltage at a much smaller pd value, and breakdown voltages which are significantly lower overall, than for Paschen curves obtained from dc discharges. The differences between the two systems are explained using a simple analytic model. A Particle-in-Cell simulation is used to investigate a similar pd range and examine the effect of the secondary emission coefficient on the rf breakdown curve, particularly at low pd values. Analytic curves are fitted to both experimental and simulation results.

  16. Argon Shrouded Plasma Spraying of Tantalum over Titanium for Corrosion Protection in Fluorinated Nitric Acid Media

    Science.gov (United States)

    Vetrivendan, E.; Jayaraj, J.; Ningshen, S.; Mallika, C.; Kamachi Mudali, U.

    2018-02-01

    Argon shrouded plasma spraying (ASPS) was used to deposit a Ta coating on commercially pure Ti (CP-Ti) under inert argon, for dissolver vessel application in the aqueous spent fuels reprocessing plant with high plutonium content. Oxidation during plasma spraying was minimized by shrouding argon system. Porosity and oxide content were controlled by optimizing the spraying parameters, to obtain a uniform and dense Ta coating. The Ta particle temperature and velocity were optimized by judiciously controlling the spray parameters, using a spray diagnostic charge-coupled device camera. The corrosion resistance of the Ta coatings developed by ASPS was investigated by electrochemical studies in 11.5 M HNO3 and 11.5 M HNO3 + 0.05 M NaF. Similarly, the durability of the ASPS Ta coating/substrate was evaluated as per ASTM A262 Practice-C test in boiling nitric acid and fluorinated nitric acid for 240 h. The ASPS Ta coating exhibited higher corrosion resistance than the CP-Ti substrate, as evident from electrochemical studies, and low corrosion rate with excellent coating stability in boiling nitric, and fluorinated nitric acid. The results of the present study revealed that tantalum coating by ASPS is a promising strategy for improving the corrosion resistance in the highly corrosive reprocessing environment.

  17. Emission spectroscopy of argon ferrocene mixture jet in a low pressure plasma reactor

    International Nuclear Information System (INIS)

    Tiwari, N.; Tak, A.K.; Chakravarthy, Y.; Shukla, A.; Meher, K.C.; Ghorui, S.; Thiyagarajan, T.K.

    2015-01-01

    Emission spectroscopy is employed to measure the plasma temperature and species identification in a reactor used for studying homogenous nucleation and growth of iron nano particle. Reactor employs segmented non transferred plasma torch mounted on water cooled cylindrical chamber. The plasma jet passes through graphite nozzle and expands in low pressure reactor. Ferrocene is fed into the nozzle where it mixes with Argon plasma jet. A high resolution spectrograph (SHAMROCK 303i, resolution 0.06 nm) has been used to record the spectra over a wide range. Identification of different emission lines has been done using NIST database. Lines from (700 to 860nm) were considered for calculation of temperature. Spectra were recorded for different axial location, pressure and power. Temperature was calculated using Maxwell Boltzman plot method. Variation in temperature with pressure and location is presented and possible reasons for different behaviour are explored. (author)

  18. A comparative study of carbon plasma emission in methane and argon atmospheres

    Science.gov (United States)

    Yousfi, H.; Abdelli-Messaci, S.; Ouamerali, O.; Dekhira, A.

    2018-04-01

    The interaction between laser produced plasma (LPP) and an ambient gas is largely investigated by Optical Emission Spectroscopy (OES). The analysis of carbon plasma produced by an excimer KrF laser was performed under controlled atmospheres of methane and argon. For each ambient gas, the features of produced species have been highlighted. Using the time of flight (TOF) analysis, we have observed that the C and C2 exhibit a triple and a double peaks respectively in argon atmosphere in contrast to the methane atmosphere. The evolution of the first peaks of C and C2 follows the plasma expansion, whereas the second peaks move backward, undergoing reflected shocks. It was found that the translational temperature, obtained by Shifted Maxwell Boltzmann distribution function is strongly affected by the nature of ambient gas. The dissociation of CH4 by electronic impact presents the principal approach for explaining the emission of CH radical in reactive plasma. Some chemical reactions have been proposed in order to explain the formation process of molecular species.

  19. Argon-plasma treatment in benign metastasizing leiomyoma of the lung: A case report

    Directory of Open Access Journals (Sweden)

    A. Bugalho

    2010-11-01

    Full Text Available Benign metastasizing leiomyomas of the lung are rare smooth muscle cells tumours. We report the case of a 48 year-old female who was evaluated due to persistent cough, progressive dyspnoea and constitutional symptoms. Chest computed tomography revealed a left endobronchial mass, multiple parenchyma nodules and a pleural effusion. Bronchial biopsy histological features were consistent with benign metastasizing leiomyoma. The patient was successfully treated with argon-plasma and mechanical debulking. There was no disease relapse in the last four years. Resumo: Os leiomiomas benignos metastizantes pulmonares são tumores raros de células musculares lisas. Uma doente de 48 anos foi avaliada devido a tosse persistente, dispneia progressiva e sintomas constitucionais. A tomografia computorizada do tórax revelou uma massa endobrônquica à esquerda, múltiplos nódulos do parênquima pulmonar e derrame pleural. As características histológicas da biopsia brônquica foram consistentes com o diagnóstico de leiomioma benigno metastizante. A doente foi submetida a coagulação árgon-plasma e desobstrução mecânica com eficácia terapêutica. Verificou-se estabilidade clínica nos últimos quatro anos. Keywords: Benign metastasizing leiomyoma, Lung neoplasms, Diagnosis, Bronchoscopy, Management, Argon-plasma treatment, Palavras-chave: Leiomioma benigno metastizante, Neoplasias pulmonares, Diagnóstico, Broncoscopia, Tratamento, Tratamento árgon-plasma

  20. Polydiagnostic calibration performed on a low pressure surface wave sustained argon plasma

    International Nuclear Information System (INIS)

    Vries, N de; Iordanova, E I; Van Veldhuizen, E M; Mullen, J J A M van der; Palomares, J M

    2008-01-01

    The electron density and electron temperature of a low pressure surface wave sustained argon plasma have been determined using passive and active (laser) spectroscopic methods simultaneously. In this way the validity of the various techniques is established while the plasma properties are determined more precisely. The electron density, n e , is determined with Thomson scattering (TS), absolute continuum measurements, Stark broadening and an extrapolation of the atomic state distribution function (ASDF). The electron temperature, T e , is obtained using TS and absolute line intensity (ALI) measurements combined with a collisional-radiative (CR) model for argon. At an argon pressure of 15 mbar, the n e values obtained with TS and Stark broadening agree with each other within the error bars and are equal to (4 ± 0.5) x 10 19 m -3 , whereas the n e value (2 ± 0.5) x 10 19 m -3 obtained from the continuum is about 30% lower. This suggests that the used formula and cross-section values for the continuum method have to be reconsidered. The electron density determined by means of extrapolation of the ASDF to the continuum is too high (∼10 20 m -3 ). This is most probably related to the fact that the plasma is strongly ionizing so that the extrapolation method is not justified. At 15 mbar, the T e values obtained with TS are equal to 13 400 ± 1100 K while the ALI/CR-model yields an electron temperature that is about 10% lower. It can be concluded that the passive results are in good or fair agreement with the active results. Therefore, the calibrated passive methods can be applied to other plasmas in a similar regime for which active diagnostic techniques cannot be used.

  1. Polydiagnostic calibration performed on a low pressure surface wave sustained argon plasma

    Energy Technology Data Exchange (ETDEWEB)

    Vries, N de; Iordanova, E I; Van Veldhuizen, E M; Mullen, J J A M van der [Department of Applied Physics, Eindhoven University of Technology, PO Box 513, 5600 MB Eindhoven (Netherlands); Palomares, J M [Departamento de Fisica, Universidad de Cordoba, Campus de Rabanales, ed. C-2, 14071 Cordoba (Spain)], E-mail: j.j.a.m.v.d.Mullen@tue.nl

    2008-10-21

    The electron density and electron temperature of a low pressure surface wave sustained argon plasma have been determined using passive and active (laser) spectroscopic methods simultaneously. In this way the validity of the various techniques is established while the plasma properties are determined more precisely. The electron density, n{sub e}, is determined with Thomson scattering (TS), absolute continuum measurements, Stark broadening and an extrapolation of the atomic state distribution function (ASDF). The electron temperature, T{sub e}, is obtained using TS and absolute line intensity (ALI) measurements combined with a collisional-radiative (CR) model for argon. At an argon pressure of 15 mbar, the n{sub e} values obtained with TS and Stark broadening agree with each other within the error bars and are equal to (4 {+-} 0.5) x 10{sup 19} m{sup -3}, whereas the n{sub e} value (2 {+-} 0.5) x 10{sup 19} m{sup -3} obtained from the continuum is about 30% lower. This suggests that the used formula and cross-section values for the continuum method have to be reconsidered. The electron density determined by means of extrapolation of the ASDF to the continuum is too high ({approx}10{sup 20} m{sup -3}). This is most probably related to the fact that the plasma is strongly ionizing so that the extrapolation method is not justified. At 15 mbar, the T{sub e} values obtained with TS are equal to 13 400 {+-} 1100 K while the ALI/CR-model yields an electron temperature that is about 10% lower. It can be concluded that the passive results are in good or fair agreement with the active results. Therefore, the calibrated passive methods can be applied to other plasmas in a similar regime for which active diagnostic techniques cannot be used.

  2. Comparison in the analytical performance between krypton and argon glow discharge plasmas as the excitation source for atomic emission spectrometry.

    Science.gov (United States)

    Wagatsuma, Kazuaki

    2009-04-01

    The emission characteristics of ionic lines of nickel, cobalt, and vanadium were investigated when argon or krypton was employed as the plasma gas in glow discharge optical emission spectrometry. A dc Grimm-style lamp was employed as the excitation source. Detection limits of the ionic lines in each iron-matrix alloy sample were compared between the krypton and the argon plasmas. Particular intense ionic lines were observed in the emission spectra as a function of the discharge gas (krypton or argon), such as the Co II 258.033 nm for krypton and the Co II 231.707 nm for argon. The explanation for this is that collisions with the plasma gases dominantly populate particular excited levels of cobalt ion, which can receive the internal energy from each gas ion selectively, for example, the 3d(7)4p (3)G(5) (6.0201 eV) for krypton and the 3d(7)4p (3)G(4) (8.0779 eV) for argon. In the determination of nickel as well as cobalt in iron-matrix samples, more sensitive ionic lines could be found in the krypton plasma rather than the argon plasma. Detection limits in the krypton plasma were 0.0039 mass% Ni for the Ni II 230.299-nm line and 0.002 mass% Co for the Co II 258.033-nm line. However, in the determination of vanadium, the argon plasma had better analytical performance, giving a detection limit of 0.0023 mass% V for the V II 309.310-nm line.

  3. Waves generated in the vicinity of an argon plasma gun in the ionosphere

    Science.gov (United States)

    Cahill, L. J., Jr.; Arnoldy, R. L.; Lysak, R. L.; Peria, W.; Lynch, K. A.

    1993-01-01

    Wave and particle observations were made in the close vicinity of an argon plasma gun carned to over 600 km altitude on a sounding rocket. The gun was carned on a subpayload, separated from the main payload early in the flight. Twelve-second argon ion ejections were energized alternately with a peak energy of 100 or 200 eV. They produced waves, with multiple harmonics, in the range of ion cyclotron waves, 10 to 1000 Hz at rocket altitudes. Many of these waves could not be identified as corresponding to the cyclotron frequencies of any of the ions, argon or ambient, known to be present. In addition, the wave frequencies were observed to rise and fall and to change abruptly during a 12-s gun operation. The wave amplitudes, near a few hundred Hertz, were of the order of O. 1 V/m. Some of the waves may be ion-ion hybrid waves. Changes in ion populations were observed at the main payload and at the subpayload during gun operations. A gun-related, field-aligned, electron population also appeared.

  4. Properties of hotspots in plasma focus discharges operating in hydrogen-argon mixtures

    International Nuclear Information System (INIS)

    Silva, P; Favre, M

    2002-01-01

    We have investigated the properties of hotspots formed in low energy plasma focus (PF) discharges operating in hydrogen-argon mixtures, at 140 kA current level. A combination of filtered pinhole and slit-wire camera is used to measure the hotspot size and temperature. The results show that the best conditions for reproducible and localized hotspot formation are obtained by adjusting the base pressure in such a way that the mass load allows the time of first radial collapse to coincide with peak current. When the PF is operated with 20% argon content, rather uniform hotspots, of 115 μm characteristic size and 300 eV characteristic temperature, are produced with a better than 80% reproducibility in their axial localization. The electron density in the hotspots is estimated to be ∼10 20 cm -3 . Calculations performed with a CRE code indicate that a significant fraction of the radiation is emitted in the 3.2 to 3.88 keV region, corresponding to K α emission from highly ionized argon

  5. Predictive Value of Whole Blood and Plasma Coagulation Tests for Intra- and Postoperative Bleeding Risk: A Systematic Review

    DEFF Research Database (Denmark)

    Larsen, Julie Brogaard; Hvas, Anne-Mette

    2017-01-01

    review of the existing literature assessing the ability of whole blood coagulation (thromboelastography [TEG]/thromboelastometry [ROTEM]/Sonoclot), platelet function tests, and standard plasma-based coagulation tests to predict bleeding in the perioperative setting. We searched PubMed and Embase...... value of testing in patients receiving antithrombotic medication. In general, studies reported low positive predictive values for perioperative testing, whereas negative predictive values were high. The studies yielded moderate areas under receiver operator characteristics (ROC) curve (for the majority...... recommend that both whole blood and plasma-based coagulation tests are primarily used in case of bleeding and not for screening in unselected patients prior to surgery....

  6. Argon ion implantation inducing modifications in the properties of benzene plasma polymers

    International Nuclear Information System (INIS)

    Rangel, E.C.; Cruz, N.C.; Santos, D.C.R.; Algatti, M.A.; Mota, R.P.; Honda, R.Y.; Silva, P.A.F.; Costa, M.S.; Tabacniks, M.H.

    2002-01-01

    Benzene plasma polymer films were bombarded with Ar ions by plasma immersion ion implantation. The treatments were performed using argon pressure of 3 Pa and 70 W of applied power. The substrate holder was polarized with high voltage negative pulses (25 kV, 3 Hz). Exposure time to the immersion plasma, t, was varied from 0 to 9000 s. Optical gap and chemical composition of the samples were determined by ultraviolet-visible and Rutherford backscattering spectroscopies, respectively. Film wettability was investigated by the contact angle between a water drop and the film surface. Nanoindentation technique was employed in the hardness measurements. It was observed growth in carbon and oxygen concentrations while there was decrease in the concentration of H atoms with increasing t. Furthermore, film hardness and wettability increased and the optical gap decreased with t. Interpretation of these results is proposed in terms of the chain crosslinking and unsaturation

  7. Integral simulation of the creation and expansion of a transonic argon plasma

    International Nuclear Information System (INIS)

    Peerenboom, K S C; Goedheer, W J; Van Dijk, J; Van der Mullen, J J A M

    2010-01-01

    A transonic argon plasma is studied in an integral simulation where both the plasma creation and expansion are incorporated in the same model. This integral approach allows for simulation of expanding plasmas where the Mach number is not known a priori. Results of this integral simulation are validated with semi-analytical models. Inside the creation region the results for the electron temperature, the heavy particle temperature and the electron density are compared with a global model of the creation region. In the expansion region, the simulation results of the compressible flow field are compared with predictions for the shock position. Both the results inside the creation region as well as in the expansion region are in good agreement with the semi-analytical models.

  8. Effect of Argon Plasma Treatment Variables on Wettability and Antibacterial Properties of Polyester Fabrics

    Science.gov (United States)

    Senthilkumar, Pandurangan; Karthik, Thangavelu

    2016-04-01

    In this research work, the effect of argon plasma treatment variables on the comfort and antibacterial properties of polyester fabric has been investigated. The SEM micrographs and FTIR analysis confirms the modification of fabric surface. The Box-Behnken design was used for the optimization of plasma process variables and to evaluate the effects and interactions of the process variables, i.e. operating power, treatment time and distance between the electrodes on the characteristics of polyester fabrics. The optimum conditions of operating power 600 W, treatment time 30 s, and the distance between the electrodes of 2.8 mm was arrived using numerical prediction tool in Design-Expert software. The plasma treated polyester fabrics showed better fabric characteristics particularly in terms of water vapour permeability, wickability and antibacterial activity compared to untreated fabrics, which confirms that the modified structure of polyester fabric.

  9. Computational study of plasma-solid interaction in DC glow discharge in argon plasma at medium pressures

    International Nuclear Information System (INIS)

    Havlickova, E; Bartos, P; Hrach, R

    2007-01-01

    In the presented contribution two groups of techniques of computational physics-fluid modelling and non self-consistent particle technique were used to study plasma-solid interaction in argon plasma. We focused both on the physical processes taking place in the sheath at various pressures and on the problems of computational physics. The attention was given to preparation of two-dimensional fluid models with realistic assumptions about physical processes taking place in plasma during the plasma-solid interaction, further to improvement of the non self-consistent technique of particle modelling, where the external electric field was obtained either from the fluid model or directly from the trajectories of charged particles and finally to efficiency of individual algorithms

  10. Spectroscopic study of atmospheric pressure 915 MHz microwave plasma at high argon flow rate

    International Nuclear Information System (INIS)

    Miotk, R; Hrycak, B; Jasinski, M; Mizeraczyk, J

    2012-01-01

    In this paper results of optical emission spectroscopic (OES) study of atmospheric pressure microwave 915 MHz argon plasma are presented. The plasma was generated in microwave plasma source (MPS) cavity-resonant type. The aim of research was determination of electron excitation temperature T exc gas temperature Tg and electron number density n e . All experimental tests were performed with a gas flow rate of 100 and 200 l/min and absorbed microwave power PA from 0.25 to 0.9 kW. The emission spectra at the range of 300 – 600 nm were recorded. Boltzmann plot method for argon 5p – 4s and 5d – 4p transition lines allowed to determine T exc at level of 7000 K. Gas temperature was determined by comparing the measured and simulated spectra using LIFBASE program and by analyzing intensities of two groups of unresolved rotational lines of the OH band. Gas temperature ranged 600 – 800 K. The electron number density was determined using the method based on the Stark broadening of hydrogen H β line. The measured n e rang ed 2 × 10 15 − 3.5×10 15 cm −3 , depending on the absorbed microwave power. The described MPS works very stable with various working gases at high flow rates, that makes it an attractive tool for different gas processing.

  11. Particle-in-Cell Modeling of Magnetized Argon Plasma Flow Through Small Mechanical Apertures

    Energy Technology Data Exchange (ETDEWEB)

    Adam B. Sefkow and Samuel A. Cohen

    2009-04-09

    Motivated by observations of supersonic argon-ion flow generated by linear helicon-heated plasma devices, a three-dimensional particle-in-cell (PIC) code is used to study whether stationary electrostatic layers form near mechanical apertures intersecting the flow of magnetized plasma. By self-consistently evaluating the temporal evolution of the plasma in the vicinity of the aperture, the PIC simulations characterize the roles of the imposed aperture and applied magnetic field on ion acceleration. The PIC model includes ionization of a background neutral-argon population by thermal and superthermal electrons, the latter found upstream of the aperture. Near the aperture, a transition from a collisional to a collisionless regime occurs. Perturbations of density and potential, with mm wavelengths and consistent with ion acoustic waves, propagate axially. An ion acceleration region of length ~ 200-300 λD,e forms at the location of the aperture and is found to be an electrostatic double layer, with axially-separated regions of net positive and negative charge. Reducing the aperture diameter or increasing its length increases the double layer strength.

  12. Particle-in-Cell Modeling of Magnetized Argon Plasma Flow Through Small Mechanical Apertures

    International Nuclear Information System (INIS)

    Sefkow, Adam B.; Cohen, Samuel A.

    2009-01-01

    Motivated by observations of supersonic argon-ion flow generated by linear helicon-heated plasma devices, a three-dimensional particle-in-cell (PIC) code is used to study whether stationary electrostatic layers form near mechanical apertures intersecting the flow of magnetized plasma. By self-consistently evaluating the temporal evolution of the plasma in the vicinity of the aperture, the PIC simulations characterize the roles of the imposed aperture and applied magnetic field on ion acceleration. The PIC model includes ionization of a background neutral-argon population by thermal and superthermal electrons, the latter found upstream of the aperture. Near the aperture, a transition from a collisional to a collisionless regime occurs. Perturbations of density and potential, with mm wavelengths and consistent with ion acoustic waves, propagate axially. An ion acceleration region of length ∼ 200-300 λ D,e forms at the location of the aperture and is found to be an electrostatic double layer, with axially-separated regions of net positive and negative charge. Reducing the aperture diameter or increasing its length increases the double layer strength

  13. Numerical simulations of a nonequilibrium argon plasma in a shock-tube experiment

    Science.gov (United States)

    Cambier, Jean-Luc

    1991-01-01

    A code developed for the numerical modeling of nonequilibrium radiative plasmas is applied to the simulation of the propagation of strong ionizing shock waves in argon gas. The simulations attempt to reproduce a series of shock-tube experiments which will be used to validate the numerical models and procedures. The ability to perform unsteady simulations makes it possible to observe some fluctuations in the shock propagation, coupled to the kinetic processes. A coupling mechanism by pressure waves, reminiscent of oscillation mechanisms observed in detonation waves, is described. The effect of upper atomic levels is also briefly discussed.

  14. Effect of neutral gas heating in argon radio frequency inductively coupled plasma

    International Nuclear Information System (INIS)

    Chin, O.H.; Jayapalan, K.K.; Wong, C.S.

    2014-01-01

    Heating of neutral gas in inductively coupled plasma (ICP) is known to result in neutral gas depletion. In this work, this effect is considered in the simulation of the magnetic field distribution of a 13.56 MHz planar coil ICP. Measured electron temperatures and densities at argon pressures of 0.03, 0.07 and 0.2 mbar were used in the simulation whilst neutral gas temperatures were heuristically fitted. The simulated results showed reasonable agreement with the measured magnetic field profile. (author)

  15. Experimental study of the electron-atom Bremsstrahlung emission in an argon plasma jet

    International Nuclear Information System (INIS)

    Ranson, P.; Vallee, O.; Chapelle, J.

    1977-01-01

    Electron-neutral atom bremsstrahlung is studied between 0.4 μm and 5 μm in a decaying argon plasma jet; in visible and infra-red range, some discrepancies appear between experimental results and theoretical calculations of different authors (Geltman, Stallcop). In the infra-red, the discrepancy can be partly explained because theoretical elastic cross sections are higher than experimental values in the vicinity of the Ramsauer minimum. In the visible range, a very small amount of fast electrons due to superelastic and recombination collisions explain the observed discrepancy [fr

  16. Cylindrical stationary striations in surface wave produced plasma columns of argon

    Science.gov (United States)

    Kumar, Rajneesh; Kulkarni, Sanjay V.; Bora, Dhiraj

    2007-12-01

    Striations are a good example of manifestation of a glow discharge. In the present investigation, stationary striations in the surface wave produced plasma column are formed. Physical parameters (length, number, etc.) of such striations can be controlled by operating parameters. With the help of bifurcation theory, experimental results are explained by considering two-step ionization in the surface wave discharge mechanism in argon gas. It is also observed that the bifurcation parameter is a function of input power, working pressure, and tube radius.

  17. Cold plasma interactions with plants: Morphing and movements of Venus flytrap and Mimosa pudica induced by argon plasma jet.

    Science.gov (United States)

    Volkov, Alexander G; Xu, Kunning G; Kolobov, Vladimir I

    2017-12-01

    Low temperature (cold) plasma finds an increasing number of applications in biology, medicine and agriculture. In this paper, we report a new effect of plasma induced morphing and movements of Venus flytrap and Mimosa pudica. We have experimentally observed plasma activation of sensitive plant movements and morphing structures in these plants similar to stimulation of their mechanosensors in vivo. Application of an atmospheric pressure argon plasma jet to the inside or outside of a lobe, midrib, or cilia in Dionaea muscipula Ellis induces trap closing. Treatment of Mimosa pudica by plasma induces movements of pinnules and petioles similar to the effects of mechanical stimulation. We have conducted control experiments and simulations to illustrate that gas flow and UV radiation associated with plasma are not the primary reasons for the observed effects. Reactive oxygen and nitrogen species (RONS) produced by cold plasma in atmospheric air appear to be the primary reason of plasma-induced activation of phytoactuators in plants. Some of these RONS are known to be signaling molecules, which control plants' developmental processes. Understanding these mechanisms could promote plasma-based technology for plant developmental control and future use for plant protection from pathogens. Our work offers new insight into mechanisms which trigger plant morphing and movement. Copyright © 2017 Elsevier B.V. All rights reserved.

  18. Anion dynamics in the first 10 milliseconds of an argon-acetylene radio-frequency plasma

    International Nuclear Information System (INIS)

    Van de Wetering, F M J H; Beckers, J; Kroesen, G M W

    2012-01-01

    The time evolution of the smallest anions (C 2 H - and H 2 CC - ), just after plasma ignition, is studied by means of microwave cavity resonance spectroscopy (MCRS) in concert with laser-induced photodetachment under varying gas pressure and temperature in an argon-acetylene radio-frequency (13.56 MHz) plasma. These anions act as an initiator for spontaneous dust particle formation in these plasmas. With an intense 355 nm Nd:YAG laser pulse directed through the discharge, electrons are detached only from these anions present in the laser path. This results in a sudden increase in the electron density in the plasma, which can accurately and with sub-microsecond time resolution be measured with MCRS. By adjusting the time after plasma ignition at which the laser is fired through the discharge, the time evolution of the anion density can be studied. We have operated in the linear regime: the photodetachment signal is proportional to the laser intensity. This allowed us to study the trends of the photodetachment signal as a function of the operational parameters of the plasma. The density of the smallest anions steadily increases in the first few milliseconds after plasma ignition, after which it reaches a steady state. While keeping the gas density constant, increasing the gas temperature in the range 30-120 °C limits the number of smallest anions and saturates at a temperature of about 90 °C. A reaction pathway is proposed to explain the observed trends.

  19. Theoretical investigation of thermophysical properties in two-temperature argon-helium thermal plasma

    International Nuclear Information System (INIS)

    Sharma, Rohit; Singh, Kuldip; Singh, Gurpreet

    2011-01-01

    The thermophysical properties of argon-helium thermal plasma have been studied in the temperature range from 5000 to 40 000 K at atmospheric pressure in local thermodynamic equilibrium and non-local thermodynamic equilibrium conditions. Two cases of thermal plasma considered are (i) ground state plasma in which all the atoms and ions are assumed to be in the ground state and (ii) excited state plasma in which atoms and ions are distributed over various possible excited states. The influence of electronic excitation and non-equilibrium parameter θ = T e /T h on thermodynamic properties (composition, degree of ionization, Debye length, enthalpy, and total specific heat) and transport properties (electrical conductivity, electron thermal conductivity, and thermal diffusion ratio) have been studied. Within the framework of Chapman-Enskog method, the higher-order contributions to transport coefficient and their convergence are studied. The influence of different molar compositions of argon-helium plasma mixture on convergence of higher-orders is investigated. Furthermore, the effect of different definitions of Debye length has also been examined for electrical conductivity and it is observed that electrical conductivity with the definition of Debye length (in which only electrons participate in screening) is less than that of the another definition (in which both the electrons and ions participate in screening) and this deviation increases with electron temperature. Finally, the effect of lowering of ionization energy is examined on electron number density, Debye length, and higher-order contribution to electrical conductivity. It is observed that the lowering of the ionization energy affects the electron transport-properties and consequently their higher-order contributions depending upon the value of the non-equilibrium parameter θ.

  20. Conclusive evidence of abrupt coagulation inside the void during cyclic nanoparticle formation in reactive plasma

    International Nuclear Information System (INIS)

    Wetering, F. M. J. H. van de; Nijdam, S.; Beckers, J.

    2016-01-01

    In this letter, we present scanning electron microscopy (SEM) results that confirm in a direct way our earlier explanation of an abrupt coagulation event as the cause for the void hiccup. In a recent paper, we reported on the fast and interrupted expansion of voids in a reactive dusty argon–acetylene plasma. The voids appeared one after the other, each showing a peculiar, though reproducible, behavior of successive periods of fast expansion, abrupt contraction, and continued expansion. The abrupt contraction was termed “hiccup” and was related to collective coagulation of a new generation of nanoparticles growing in the void using relatively indirect methods: electron density measurements and optical emission spectroscopy. In this letter, we present conclusive evidence using SEM of particles collected at different moments in time spanning several growth cycles, which enables us to follow the nanoparticle formation process in great detail.

  1. Energy loss of argon in a laser-generated carbon plasma.

    Science.gov (United States)

    Frank, A; Blazević, A; Grande, P L; Harres, K; Hessling, T; Hoffmann, D H H; Knobloch-Maas, R; Kuznetsov, P G; Nürnberg, F; Pelka, A; Schaumann, G; Schiwietz, G; Schökel, A; Schollmeier, M; Schumacher, D; Schütrumpf, J; Vatulin, V V; Vinokurov, O A; Roth, M

    2010-02-01

    The experimental data presented in this paper address the energy loss determination for argon at 4 MeV/u projectile energy in laser-generated carbon plasma covering a huge parameter range in density and temperature. Furthermore, a consistent theoretical description of the projectile charge state evolution via a Monte Carlo code is combined with an improved version of the CasP code that allows us to calculate the contributions to the stopping power of bound and free electrons for each projectile charge state. This approach gets rid of any effective charge description of the stopping power. Comparison of experimental data and theoretical results allows us to judge the influence of different plasma parameters.

  2. Deposition of a-SiC:H using organosilanes in an argon/hydrogen plasma

    International Nuclear Information System (INIS)

    Maya, L.

    1993-01-01

    Selected organosilanes were examined as precursors for the deposition of amorphous hydrogenated silicon carbide in an argon/hydrogen plasma. Effect of process variables on the quality of the films was established by means of FTIR, Auger spectroscopy, XPS, XRD, chemical analysis, and weight losses upon pyrolysis. For a given power level there is a limiting feeding rate of the precursor under which operation of the system is dominated by thermodynamics and leads to high quality silicon carbide films that are nearly stoichiometric and low in hydrogen. Beyond that limit, carbosilane polymer formation and excessive hydrogen incorporation takes place. The hydrogen content of the plasma affects the deposition rate and the hydrogen content of the film. In the thermodynamically dominated regime the nature of the precursor has no effect on the quality of the film, it affects only the relative utilization efficiency

  3. Spectroscopic evaluation of the effect of the microparticles on radiofrequency argon plasma

    International Nuclear Information System (INIS)

    Mitic, S; Pustylnik, M Y; Morfill, G E

    2009-01-01

    Axial distributions of 1s excited states of argon were measured in a radiofrequency (RF) discharge by a self-absorption method. Experiments were performed in the PK-3+ chamber, designed for microgravity experiments in complex (dusty) plasmas on board the International Space Station. A correction of a standard self-absorption method for the extinction of the light by the levitating microparticles is proposed. Distributions, measured at the same discharge conditions in a microparticle-free discharge and a discharge containing a cloud of levitating microparticles, revealed the non-local influence of the microparticle cloud on the discharge plasma. The most probable cause of this influence is the disturbance of the ionization balance by the levitating microparticles.

  4. Diagnostics of the influence of levitating microparticles on the radiofrequency argon plasma

    International Nuclear Information System (INIS)

    Pustylnik, Mikhail Y.; Mitic, Slobodan; Klumov, Boris A.; Morfill, Gregor E.

    2010-01-01

    The effect of a levitating cloud of microparticles on the parameters of a radiofrequency (RF) plasma has been studied by means of two experimental techniques. Axial distributions of 1 s excited states of argon were measured by a self-absorption method. A correction of a standard self-absorption method for the extinction of the light by the levitating microparticles is proposed. In addition the electron temperature was estimated using the optical emission spectroscopy. Measurements at the same discharge conditions in a microparticle-free discharge and discharge, containing a cloud of levitating microparticles, revealed the non-local influence of the microparticle cloud on the discharge plasma. The most probable cause of this influence is the disturbance of the ionization balance by the levitating microparticles.

  5. Application of argon atmospheric cold plasma for indium tin oxide (ITO) based diodes

    Science.gov (United States)

    Akbari Nia, S.; Jalili, Y. Seyed; Salar Elahi, A.

    2017-09-01

    Transparent Conductive Oxide (TCO) layers due to transparency, high conductivity and hole injection capability have attracted a lot of attention. One of these layers is Indium Tin Oxide (ITO). ITO due to low resistance, transparency in the visible spectrum and its proper work function is widely used in the manufacture of organic light emitting diodes and solar cells. One way for improving the ITO surface is plasma treatment. In this paper, changes in surface morphology, by applying argon atmospheric pressure cold plasma, was studied through Atomic Force Microscopic (AFM) image analysis and Fourier Transform Infrared Spectroscopy (FTIR) analysis. FTIR analysis showed functional groups were not added or removed, but chemical bond angle and bonds strength on the surface were changed and also AFM images showed that surface roughness was increased. These factors lead to the production of diodes with enhanced Ohmic contact and injection mechanism which are more appropriate in industrial applications.

  6. Investigation of Capacitively Coupled Argon Plasma Driven by Dual-Frequency with Different Frequency Configurations

    International Nuclear Information System (INIS)

    Yu Yiqing; Xin Yu; Ning Zhaoyuan; Lu Wenqi

    2011-01-01

    Low pressure argon dual-frequency (DF) capacitively coupled plasma (CCP) is generated by using different frequency configurations, such as 13.56/2, 27/2, 41/2, and 60/2 MHz. Characteristics of the plasma are investigated by using a floating double electrical probe and optical emission spectroscopy (OES). It is shown that in the DF-CCPs, the electron temperature T e decreases with the increase in exciting frequency, while the onset of 2 MHz induces a sudden increase in T e and the electron density increases basically with the increase in low frequency (LF) power. The intensity of 750.4 nm emission line increases with the LF power in the case of 13.56/2 MHz, while different tendencies of line intensity with the LF power appear for other configurations. The reason for this is also discussed.

  7. Mass spectrometer diagnostic technique in the study of stationary afterglow plasmas in helium, argon and krypton

    International Nuclear Information System (INIS)

    Langenwalter, M.

    1979-01-01

    Since some years the method of massspectrometric monitoring has become an important tool in the analysis of time resolved (or stationary) afterglow plasmas. The present thesis reports the construction and testing of a new fully bakeable UHV-stationary-afterglow-apparatus using a hollow cathode discharge as plasma source for the first time. The hollow cathode is moveable perpendicular to its axis relative to the sampling orifice (i.e. a very small hole at the centre of the plasma container's boundary), so that the radical distribution of the charged particle density can be studied. Several specific extraction conditions for ions from the plasma especially the sampling probe potential have been systematically investigated. Results are illustrated and discussed. The new apparatus has been tested by determining the ambipolar diffusion coefficient of the molecular ion He 2 + in a pure Helium-plasma in thermal equilibrium. The present result (Dsub(a2) = 603 +- 38 / P 0 cm 2 s -1 ) is in agreement with results reported by other workers. Finally an example for the radial behaviour of the Ar + -sampling current in an Argon-discharge for several different times in the afterglow period is given. The shown behaviour agrees relatively well with the theoretically predicted radial ion density distribution, i.e. the zero-order Ressel'function. (Author)

  8. ULTRAVIOLET INDUCED MOTION OF A FLUORESCENT DUST CLOUD IN AN ARGON DIRECT CURRENT GLOW DISCHARGE PLASMA

    Energy Technology Data Exchange (ETDEWEB)

    Hvasta, M.G.; and Zwicker, A.

    2008-01-01

    Dusty plasmas consist of electrons, ions, neutrals and nm-μm sized particles commonly referred to as dust. In man-made plasmas this dust may represent impurities in a tokamak or plasma etching processing. In astrophysical plasmas this dust forms structures such as planetary rings and comet tails. To study dusty plasma dynamics an experiment was designed in which a 3:1 silica (<5 μm diameter) and fl uorescent dust mixture was added to an argon DC glow discharge plasma and exposed to UV radiation. This fl uorescent lighting technique offers an advantage over laser scattering (which only allows two-dimensional slices of the cloud to be observed) and is simpler than scanning mirror techniques or particle image velocimetry. Under typical parameters (P=150 mTorr, V anode= 100 V, Vcathode= -400 V, Itotal < 2mA) when the cloud is exposed to the UV light (100W, λ = 365 nm) the mixture fl uoresces, moves ~2mm towards the light source and begins rotating in a clockwise manner (as seen from the cathode). By calibrating a UV lamp and adjusting the relative intensity of the UV with a variable transformer it was found that both translational and rotational velocities are a function of UV intensity. Additionally, it was determined that bulk cloud rotation is not seen when the dust tray is not grounded while bulk translation is. This ongoing experiment represents a novel way to control contamination in man-made plasmas and a path to a better understanding of UV-bathed plasma systems in space..

  9. Development of plasma properties along thermal plasma jet generated by hybrid water-argon torch

    Czech Academy of Sciences Publication Activity Database

    Kavka, Tetyana; Hrabovský, Milan

    2002-01-01

    Roč. 52, supplement D (2002), s. 637-642 ISSN 0011-4626. [Symposium on Plasma Physics and Technology/20th./. Prague, 10.06.2002-13.06.2002] Institutional research plan: CEZ:AV0Z2043910 Keywords : thermal plasma, plasma jet, enthalpy probe Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 0.311, year: 2002

  10. Influence of the centrifuge time of primary plasma tubes on routine coagulation testing.

    Science.gov (United States)

    Lippi, Giuseppe; Salvagno, Gian Luca; Montagnana, Martina; Manzato, Franco; Guidi, Gian Cesare

    2007-07-01

    Preparation of blood specimens is a major bottleneck in the laboratory throughput. Reliable strategies for reducing the time required for specimen processing without affecting quality should be acknowledged, especially for laboratories performing stat analyses. The present investigation was planned to establish a minimal suitable centrifuge time for primary samples collected for routine coagulation testing. Five sequential primary vacuum tubes containing 0.109 mol/l buffered trisodium citrate were collected from 10 volunteers and were immediately centrifuged on a conventional centrifuge at 1500 x g, at room temperature for 1, 2, 5, 10 and 15 min, respectively. Hematological and routine coagulation testing, including prothrombin time, activated partial thromboplastin time and fibrinogen, were performed. The centrifugation time was inversely associated with residual blood cell elements in plasma, especially platelets. Statistically significant variations from the reference 15-min centrifuge specimens were observed for fibrinogen in samples centrifuged for 5 min at most and for the activated partial thromboplastin time in samples centrifuged for 2 min at most. Meaningful biases related to the desirable bias were observed for fibrinogen in samples centrifuged for 2 min at most, and for the activated partial thromboplastin time in samples centrifuged for 1 min at most. According to our experimental conditions, a 5-10 min centrifuge time at 1500 x g may be suitable for primary tubes collected for routine coagulation testing.

  11. Irradiation of silver and agar/silver nanoparticles with argon, oxygen glow discharge plasma, and mercury lamp.

    Science.gov (United States)

    Ahmad, Mahmoud M; Abdel-Wahab, Essam A; El-Maaref, A A; Rawway, Mohammed; Shaaban, Essam R

    2014-01-01

    The irradiation effect of argon, oxygen glow discharge plasma, and mercury lamp on silver and agar/silver nanoparticle samples is studied. The irradiation time dependence of the synthesized silver and agar/silver nanoparticle absorption spectra and their antibacterial effect are studied and compared. In the agar/silver nanoparticle sample, as the irradiation time of argon glow discharge plasma or mercury lamp increases, the peak intensity and the full width at half maximum, FWHM, of the surface plasmon resonance absorption band is increased, however a decrease of the peak intensity with oxygen glow plasma has been observed. In the silver nanoparticle sample, as the irradiation time of argon, oxygen glow discharge plasma or mercury lamp increases, the peak intensity of the surface plasmon resonance absorption band is increased, however, there is no significant change in the FWHM of the surface plasmon resonance absorption band. The SEM results for both samples showed nanoparticle formation with mean size about 50 nm and 40 nm respectively. Throughout the irradiation time with the argon, oxygen glow discharge plasma or mercury lamp, the antibacterial activity of several kinds of Gram-positive and Gram-negative bacteria has been examined.

  12. Argon plasma treatment of silicon nitride (SiN) for improved antireflection coating on c-Si solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Ghosh, Hemanta; Mitra, Suchismita; Saha, Hiranmay; Datta, Swapan Kumar; Banerjee, Chandan, E-mail: chandanbanerjee74@gmail.com

    2017-01-15

    Highlights: • Antireflection properties of argon plasma treated silicon nitride layer and its effect on crystalline silicon solar cell. • The reduction in reflection due to the formation of a silicon oxynitride/silicon nitride double layer. • EQE reveals a relative increase of 2.72% in J{sub sc} and 4.46% in conversion efficiency. - Abstract: Antireflection properties of argon plasma treated silicon nitride layer and its effect on crystalline silicon solar cell is presented here. Hydrogenated silicon nitride (a-SiN:H) layer has been deposited on a silicon substrate by Plasma Enhanced Chemical Vapour Deposition (PECVD) using a mixture of silane (SiH{sub 4}), ammonia (NH{sub 3}) and hydrogen (H{sub 2}) gases followed by a argon plasma treatment. Optical analysis reveals a significant reduction in reflectance after argon plasma treatment of silicon nitride layer. While FESEM shows nanostructures on the surface of the silicon nitride film, FTIR reveals a change in Si−N, Si−O and N−H bonds. On the other hand, ellipsometry shows the variation of refractive index and formation of double layer. Finally, a c-Si solar cell has been fabricated with the said anti-reflection coating. External quantum efficiency reveals a relative increase of 2.72% in the short circuit current density and 4.46% in conversion efficiency over a baseline efficiency of 16.58%.

  13. Surface modification of argon/oxygen plasma treated vulcanized ethylene propylene diene polymethylene surfaces for improved adhesion with natural rubber

    International Nuclear Information System (INIS)

    Basak, Ganesh C.; Bandyopadhyay, Abhijit; Neogi, Sudarsan; Bhowmick, Anil K.

    2011-01-01

    Vulcanized ethylene propylene diene polymethylene (EPDM) rubber surface was treated in a radio frequency capacitatively coupled low pressure argon/oxygen plasma to improve adhesion with compounded natural rubber (NR) during co-vulcanization. The plasma modified surfaces were analyzed by means of contact angle measurement, surface energy, attenuated total reflection-infrared spectroscopy, X-ray photoelectron spectroscopy, scanning electron microscopy, energy dispersive X-ray sulfur mapping and atomic force microscopy. Several experimental variables such as plasma power, length of exposure time and composition of the argon-oxygen gas mixture were considered. It was delineated that plasma treatment changed both surface composition and roughness, and consequently increased peel strength. The change in surface composition was mainly ascribed to the formation of C-O and -C=O functional groups on the vulcanized surfaces. A maximum of 98% improvement in peel strength was observed after plasma treatment.

  14. Surface modification of argon/oxygen plasma treated vulcanized ethylene propylene diene polymethylene surfaces for improved adhesion with natural rubber

    Energy Technology Data Exchange (ETDEWEB)

    Basak, Ganesh C. [Rubber Technology Centre, Indian Institute of Technology, Kharagpur 721302 (India); Bandyopadhyay, Abhijit [Department of Polymer Science and Technology, University of Calcutta, Calcutta 700 009 (India); Neogi, Sudarsan [Department of Chemical Engineering, Indian Institute of Technology, Kharagpur 721302 (India); Bhowmick, Anil K., E-mail: anilkb@rtc.iitkgp.ernet.in [Rubber Technology Centre, Indian Institute of Technology, Kharagpur 721302 (India)

    2011-01-15

    Vulcanized ethylene propylene diene polymethylene (EPDM) rubber surface was treated in a radio frequency capacitatively coupled low pressure argon/oxygen plasma to improve adhesion with compounded natural rubber (NR) during co-vulcanization. The plasma modified surfaces were analyzed by means of contact angle measurement, surface energy, attenuated total reflection-infrared spectroscopy, X-ray photoelectron spectroscopy, scanning electron microscopy, energy dispersive X-ray sulfur mapping and atomic force microscopy. Several experimental variables such as plasma power, length of exposure time and composition of the argon-oxygen gas mixture were considered. It was delineated that plasma treatment changed both surface composition and roughness, and consequently increased peel strength. The change in surface composition was mainly ascribed to the formation of C-O and -C=O functional groups on the vulcanized surfaces. A maximum of 98% improvement in peel strength was observed after plasma treatment.

  15. Study of a contracted glow in low-frequency plasma-jet discharges operating with argon

    Energy Technology Data Exchange (ETDEWEB)

    Minotti, F.; Giuliani, L.; Xaubet, M.; Grondona, D. [Departamento de Física, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, C1428EHA, Buenos Aires, Argentina and Instituto de Física del Plasma (INFIP), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Universidad de Buenos Aires - UBA, C1428EHA, Buenos Aires (Argentina)

    2015-11-15

    In this work, we present an experimental and theoretical study of a low frequency, atmospheric plasma-jet discharge in argon. The discharge has the characteristics of a contracted glow with a current channel of submillimeter diameter and a relatively high voltage cathode layer. In order to interpret the measurements, we consider the separate modeling of each region of the discharge: main channel and cathode layer, which must then be properly matched together. The main current channel was modeled, extending a previous work, as similar to an arc in which joule heating is balanced by lateral heat conduction, without thermal equilibrium between electrons and heavy species. The cathode layer model, on the other hand, includes the emission of secondary electrons by ion impact and by additional mechanisms, of which we considered emission due to collision of atoms excited at metastable levels, and field-enhanced thermionic emission (Schottky effect). The comparison of model and experiment indicates that the discharge can be effectively sustained in its contracted form by the secondary electrons emitted by collision of excited argon atoms, whereas thermionic emission is by far insufficient to provide the necessary electrons.

  16. Experimental behaviour of a argon plasma, which is passed by a high current intensity, with different magnetic field configurations; Comportamiento experimental de un plasma de argon en diferentes configuraciones de campo magnetico y a elevadas corrientes

    Energy Technology Data Exchange (ETDEWEB)

    Lozano, J

    1964-07-01

    In a lineal discharge, the longitudinal and azimuthal magnetic fields produced by the current through the tube and the returning conductors, which have 4 different forms, are determined with a magnetic probe, which has a radial and longitudinal displacement. The plasma is produced discharging a 135{mu}F and 9 KV capacitor bank through Argon at 10{sup -}1 Torr. (Author) 5 refs.

  17. The influence of ethanol addition on the spatial emission distribution of traces in a vertical argon stabilized DC arc plasma

    Directory of Open Access Journals (Sweden)

    MARIJA TODOROVIC

    2004-05-01

    Full Text Available The plasma of a vertical argon stabilized DC arc at atmospheric pressure is applied as a spectrochemical source. The lateral distributions of relative spectral line intensities of some trace elements (Zn, Pt, Cd, Mg, Ca and Al introduced into the plasma in the form of aqueous and ethanol–aqueous solutions were experimentally determined. These distributions were correlated with the calculated equilibrium plasma composition of the arc plasma. On the basis of the obtained results, an explanation of the influence of ethanol addition on the radiation densities from an arc plasma is given.

  18. Some metals determination in beers by atomic emission spectrometry of induced argon plasma

    International Nuclear Information System (INIS)

    Matsushige, I.

    1990-01-01

    It was made the identification and determination of metals in brazilian bottled and canned beer, using atomic emission spectrometry with d.c. are and argon coupled plasma excitation sources. The elements Co, Cr, Cu, Fe, Pb and Zn were determined in beer samples, after treatment with HNO sub(3) conc. /H sub(2) O sub(2) (30%). In the determination of Co, Cr, Cu, Pb and Zn and alternative method using HNO sub(3) conc. /O sub(3) was proved be useful. The results obtained for Co, Cr, Cu, Fe, Pb and Zn were below the limits established by brazilian legislation, showing the good quality of the beer concerning the metals. The results of this work were requested by the previous Ministerio do Meio Ambiente e Urbanismo in order to contribute to review the brazilian legislation in foods and beverages about metals contents. (author)

  19. Energy spectrum of argon ions emitted from Filippov type Sahand plasma focus

    International Nuclear Information System (INIS)

    Mohammadnejad, M.; Pestehe, S. J.; Mohammadi, M. A.

    2013-01-01

    The energy and flux of the argon ions produced in Sahand plasma focus have been measured by employing a well-designed Faraday cup. The secondary electron emission effects on the ion signals are simulated and the dimensions of Faraday cup are optimized to minimize these effects. The measured ion energy spectrum is corrected for the ion energy loss and charge exchange in the background gas. The effects of the capacitor bank voltage and working gas pressure on the ion energy spectrum are also investigated. It has been shown that the emitted ion number per energy increases as the capacitor bank voltage increases. Decreasing the working gas pressure leads to the increase in the number of emitted ion per energy

  20. Sulphate analysis in uranium leach iron(III) chloride solutions by inductively coupled argon plasma spectrometry

    International Nuclear Information System (INIS)

    Nirdosh, I.; Lakhani, S.; Yunus, M.Z.M.

    1993-01-01

    Inductively coupled Argon Plasma Spectrometry is used for the indirect determination of sulphate in iron(III) chloride leach solution of Elliot Lake uranium ores via addition of a known amount of barium ions and analyzing for excess of barium. The ore contains ∼ 7 wt% pyrite, FeS 2 , as the major mineral which oxidizes to generate sulphate during leaching with Fe(III). The effects of pH, the concentrations of Fe(III) and chloride ions and for presence of ethanol in the test samples on the accuracy of analysis are studied. It is found that unlike the Rhodizonate method, removal of iron(III) from or addition of ethanol to the test sample prior to analysis are not required. Linear calibration curves are obtained. (author)

  1. Experimental behaviour of a argon plasma, which is passed by a high current intensity, with different magnetic field configurations

    International Nuclear Information System (INIS)

    Lozano, J.

    1964-01-01

    In a lineal discharge, the longitudinal and azimuthal magnetic fields produced by the current through the tube and the returning conductors, which have 4 different forms, are determined with a magnetic probe, which has a radial and longitudinal displacement. The plasma is produced discharging a 135μF and 9 KV capacitor bank through Argon at 10 - 1 Torr. (Author) 5 refs

  2. Predictive modelling of the impact of argon injection on H-mode plasmas in JET with the RITM code

    International Nuclear Information System (INIS)

    Unterberg, B; Kalupin, D; Tokar', M Z; Corrigan, G; Dumortier, P; Huber, A; Jachmich, S; Kempenaars, M; Kreter, A; Messiaen, A M; Monier-Garbet, P; Ongena, J; Puiatti, M E; Valisa, M; Hellermann, M von

    2004-01-01

    Self-consistent modelling of energy and particle transport of the plasma background and impurities has been performed with the code RITM for argon seeded high density H-mode plasmas in JET. The code can reproduce both the profiles in the plasma core and the structure of the edge pedestal. The impact of argon on core transport is found to be small; in particular, no significant change in confinement is observed in both experimental and modelling results. The same transport model, which has been used to reproduce density peaking in the radiative improved mode in TEXTOR, reveals a flat density profile in Ar seeded JET H-mode plasmas in agreement with the experimental observations. This behaviour is attributed to the rather flat profile of the safety factor in the bulk of H-mode discharges

  3. Causes of plasma column contraction in surface-wave-driven discharges in argon at atmospheric pressure

    Science.gov (United States)

    Ridenti, Marco Antonio; de Amorim, Jayr; Dal Pino, Arnaldo; Guerra, Vasco; Petrov, George

    2018-01-01

    In this work we compute the main features of a surface-wave-driven plasma in argon at atmospheric pressure in view of a better understanding of the contraction phenomenon. We include the detailed chemical kinetics dynamics of Ar and solve the mass conservation equations of the relevant neutral excited and charged species. The gas temperature radial profile is calculated by means of the thermal diffusion equation. The electric field radial profile is calculated directly from the numerical solution of the Maxwell equations assuming the surface wave to be propagating in the TM00 mode. The problem is considered to be radially symmetrical, the axial variations are neglected, and the equations are solved in a self-consistent fashion. We probe the model results considering three scenarios: (i) the electron energy distribution function (EEDF) is calculated by means of the Boltzmann equation; (ii) the EEDF is considered to be Maxwellian; (iii) the dissociative recombination is excluded from the chemical kinetics dynamics, but the nonequilibrium EEDF is preserved. From this analysis, the dissociative recombination is shown to be the leading mechanism in the constriction of surface-wave plasmas. The results are compared with mass spectrometry measurements of the radial density profile of the ions Ar+ and Ar2+. An explanation is proposed for the trends seen by Thomson scattering diagnostics that shows a substantial increase of electron temperature towards the plasma borders where the electron density is small.

  4. Studies on surface graft polymerization of acrylic acid onto PTFE film by remote argon plasma initiation

    International Nuclear Information System (INIS)

    Wang Chen; Chen Jierong

    2007-01-01

    The graft polymerization of acrylic acid (AAc) was carried out onto poly(tetrafluoroethylene) (PTFE) films that had been pretreated with remote argon plasma and subsequently exposed to oxygen to create peroxides. Peroxides are known to be the species responsible for initiating the graft polymerization when PTFE reacts with AAc. We chose different parameters of remote plasma treatment to get the optimum condition for introducing maximum peroxides (2.87 x 10 -11 mol/cm 2 ) on the surface. The influence of grafted reaction conditions on the grafting degree was investigated. The maximum grafting degree was 25.2 μg/cm 2 . The surface microstructures and compositions of the AAc grafted PTFE film were characterized with the water contact angle meter, Fourier-transform infrared spectroscopy (ATR-FTIR) and X-ray photoelectron spectroscopy (XPS). Contact angle measurements revealed that the water contact angle decreased from 108 o to 41 o and the surface free energy increased from 22.1 x 10 -5 to 62.1 x 10 -5 N cm -1 by the grafting of the AAc chains. The hydrophilicity of the PTFE film surface was greatly enhanced. The time-dependent activity of the grafted surface was better than that of the plasma treated film

  5. Systematic studies of covalent functionalization of carbon nanotubes via argon plasma-assisted UV grafting

    International Nuclear Information System (INIS)

    Yan, Y H; Cui, J; Chan-Park, M B; Wang, X; Wu, Q Y

    2007-01-01

    Single-walled carbon nanotubes (SWNTs) with 1-vinylimidazole species covalently attached to their sidewalls and end caps have been prepared by ultraviolet (UV) irradiation in 1-vinylimidazole monomer. This process can be greatly assisted by argon (Ar) plasma pretreatment, which generates more defect sites at the tube ends and sidewalls acting as the active sites for the subsequent UV grafting of 1-vinylimidazole molecules. The effects of total deposited energy of Ar plasma treatment, either by change of treatment time or discharge power, on the functionalization degree and structural morphology of the resulting nanotubes are systematically studied. By control of the Ar plasma treatment time within 5 min at the discharge power of 200 W, no visible chopping of the functionalized SWNTs was observed. Under this advised optimum processing condition, the functionalization degree, estimated by x-ray photoelectron spectroscopy (XPS) measurement, is as high as around 26 wt% 1-vinylimidazole molecules grafted onto the nanotubes. This method may be extended to other reactive vinyl monomers and offers another diverse way of covalent functionalization of SWNTs

  6. Application of atmospheric-pressure argon plasma jet for bread mold decontamination

    Science.gov (United States)

    Thonglor, P.; Amnuaycheewa, P.

    2017-09-01

    Atmospheric-pressure argon plasma (APAP) is a promising non-thermal technology for microbial control and prevention minimally affecting quality of foods. Effect of APAP jet on the growth of bread molds, including two Aspergillus sp., Rhizopus stolonifer, and Penicillium roqueforti, isolated from white bread were investigated. The molds were isolated, verified, cultured to fully grown on potato dextrose agar (PDA), and subsequently treated with APAP jet using plasma generating power at 24 W for 5, 10, and 20 min, respectively. The inhibition of mold growth was investigated by comparing fungal dry weights and the effect on fungal cell structure was observed using compound light microscope. The results indicated that the 20-min treatment time is most effective in retarding the growth of the three bread molds. However, this level of generating power did not lead to destruction of the cellular structures for all the four fungi. Plasma generating power and treatment time are significant parameters determining the success of bread mold decontamination and further investigation on real bread matrix is needed.

  7. A radio-frequency nonequilibrium atmospheric pressure plasma operating with argon and oxygen

    International Nuclear Information System (INIS)

    Moravej, M.; Yang, X.; Hicks, R.F.; Penelon, J.; Babayan, S.E.

    2006-01-01

    A capacitively coupled, atmospheric pressure plasma has been developed that produces a high concentration of reactive species at a gas temperature below 300 deg. C. The concentration of ground-state oxygen atoms produced by the discharge was measured by NO titration, and found to equal 1.2 vol %, or 1.2±0.4x10 17 cm -3 , using 6.0 vol % O 2 in argon at 150 W/cm 3 . The ozone concentration determined at the same conditions was 4.3±0.5x10 14 cm -3 . A model of the gas phase reactions was developed and yielded O atom and O 3 concentrations in agreement with experiment. This plasma source etched Kapton registered at 5.0 μm/s at 280 deg. C and an electrode-to-sample spacing of 1.5 cm. This fast etch rate is attributed to the high O atom flux generated by the plasma source

  8. Pulsed cold plasma-induced blood coagulation and its pilot application in stanching bleeding during rat hepatectomy

    Science.gov (United States)

    Keping, YAN; Qikang, JIN; Chao, ZHENG; Guanlei, DENG; Shengyong, YIN; Zhen, LIU

    2018-04-01

    This paper presents plasma-induced blood coagulation and its pilot application in rat hepatectomy by using a home-made pulsed cold plasma jet. Experiments were conducted on blood coagulation in vitro, the influence of plasma on tissue in vivo, and the pilot application of rat hepatectomy. Experimental results show that the cold plasma can lead to rapid blood coagulation. Compared with the control sample, the plasma-induced agglomerated layer of blood is thicker and denser, and is mostly composed of broken platelets. When the surface of the liver was treated by plasma, the influence of the plasma can penetrate into the liver to a depth of about 500 μm. During the rat hepatectomy, cold plasma was proved to be effective for stanching bleeding on incision. No obvious bleeding was found in the abdominal cavities of all six rats 48 h after the hepatectomy. This implies that cold plasma can be an effective modality to control bleeding during surgical operation.

  9. Characterization of Modified Tapioca Starch in Atmospheric Argon Plasma under Diverse Humidity by FTIR Spectroscopy

    Science.gov (United States)

    Deeyai, P.; Suphantharika, M.; Wongsagonsup, R.; Dangtip, S.

    2013-01-01

    Tapioca is economical crop grown in Thailand and continues to be one of the major sources of starch. Nowadays, tapioca starch has been widely used in industrial applications, however the native form of starch has limited the applications. Thus scientists try to modify the properties of starch for increasing the stability of the granules, pastes to low pH, heat, and shear during the food process. We modify the tapioca starch by plasma treatment under an argon atmosphere. The degree of modification is determined by following water content in the starch granules. The tablet samples of native starch are also prepared and compared with the plasma treated starch. Before plasma treatment, the starch tablets are stored under three different relative humilities (RH) including 11%, 68%, and 78%RH, respectively. The samples are characterized using FTIR spectroscopy associated with the degree of cross-linking. The results show that the water molecules are engulfed into the starch structure in two ways, a tight bond and a weak absorption of water molecules which is represented at two wave number of 1630 cm-1 and 3272 cm-1, respectively. The degree of cross-linking can be identified from the relative intensity of these two peaks with the C—O—H peak at 993 cm-1. The results show that the degree of cross-linking increase in the plasma treated starch. The degree of cross-linking of the treated starch with high relative humidity is less than that of the treated starch with low relative humidity.

  10. Characterization of Modified Tapioca Starch in Atmospheric Argon Plasma under Diverse Humidity by FTIR Spectroscopy

    International Nuclear Information System (INIS)

    Deeyai, P.; Suphantharika, M.; Wongsagonsup, R.; Dangtip, S.

    2013-01-01

    Tapioca is economical crop grown in Thailand and continues to be one of the major sources of starch. Nowadays, tapioca starch has been widely used in industrial applications, however the native form of starch has limited the applications. Thus scientists try to modify the properties of starch for increasing the stability of the granules, pastes to low pH, heat, and shear during the food process. We modify the tapioca starch by plasma treatment under an argon atmosphere. The degree of modification is determined by following water content in the starch granules. The tablet samples of native starch are also prepared and compared with the plasma treated starch. Before plasma treatment, the starch tablets are stored under three different relative humilities (RH) including 11%, 68%, and 78%RH, respectively. The samples are characterized using FTIR spectroscopy associated with the degree of cross-linking. The results show that the water molecules are engulfed into the starch structure in two ways, a tight bond and a weak absorption of water molecules which is represented at two wave number of 1630 cm −1 and 3272 cm −1 , respectively. The degree of cross-linking can be identified from the relative intensity of these two peaks with the C—O—H peak at 993 cm −1 . The results show that the degree of cross-linking increase in the plasma treated starch. The degree of cross-linking of the treated starch with high relative humidity is less than that of the treated starch with low relative humidity

  11. Spectroscopic and probe measurements of the electron temperature in the plasma of a pulse-periodic microwave discharge in argon

    Energy Technology Data Exchange (ETDEWEB)

    Andreev, V. V., E-mail: vvandreev@mail.ru; Vasileska, I., E-mail: ivonavasileska@yahoo.com; Korneeva, M. A., E-mail: korneevama@mail.ru [Peoples’ Friendship University of Russia (Russian Federation)

    2016-07-15

    A pulse-periodic 2.45-GHz electron-cyclotron resonance plasma source on the basis of a permanent- magnet mirror trap has been constructed and tested. Variations in the discharge parameters and the electron temperature of argon plasma have been investigated in the argon pressure range of 1 × 10{sup –4} to 4 × 10{sup –3} Torr at a net pulsed input microwave power of up to 600 W. The plasma electron temperature in the above ranges of gas pressures and input powers has been measured by a Langmuir probe and determined using optical emission spectroscopy (OES) from the intensity ratios of spectral lines. The OES results agree qualitatively and quantitatively with the data obtained using the double probe.

  12. Spatio-temporal evolution of the dust particle size distribution in dusty argon rf plasmas

    International Nuclear Information System (INIS)

    Killer, Carsten; Mulsow, Matthias; Melzer, André

    2015-01-01

    An imaging Mie scattering technique has been developed to measure the spatially resolved size distribution of dust particles in extended dust clouds. For large dust clouds of micrometre-sized plastic particles confined in an radio frequency (rf) discharge, a segmentation of the dust cloud into populations of different sizes is observed, even though the size differences are very small. The dust size dispersion inside a population is much smaller than the difference between the populations. Furthermore, the dust size is found to be constantly decreasing over time while the particles are confined in an inert argon plasma. The processes responsible for the shrinking of the dust in the plasma have been addressed by mass spectrometry, ex situ microscopy of the dust size, dust resonance measurements, in situ determination of the dust surface temperature and Fourier transform infrared absorption (FT-IR). It is concluded that both a reduction of dust size and its mass density due to outgassing of water and other volatile constituents as well as chemical etching by oxygen impurities are responsible for the observations. (paper)

  13. Radiation accompanied by self absorption in nonequilibrium argon plasma flow in a circular tube

    International Nuclear Information System (INIS)

    Shirai, Hiroyuki; Tabei, Katsuine; Koaizawa, Hisashi.

    1983-01-01

    In high temperature, nonequilibrium plasma flow, generally strong radiation arises, but the radiation phenomena are complicated by the thermo-chemical nonequilibrium of gas and the self absorption in light path, accordingly it is important to correctly understand and estimate their effects. In this research, for the radiation from the argon afterglow plasma flow with large nonequilibrium property in a circular tube, the experimental and theoretical studies were carried out taking the self absorption in consideration. Experimentally, the absolute intensity distribution of the radiated spectrum lines was measured from outside of the tube, and converted to the true radial distribution of atom number density at excited level using the mathematical conversion theory for the radiation accompanied by absorption of Elder et al. Theoretically, the radial distributions of electron temperature, electron density and atom temperature measured in the tube were applied to the collision-radiation process model including self absorption, and the distribution of the atom number density at excited level was calculated. Fairly good agreement was obtained between both results, and it was found that the consideration of self absorption was important. The theory, the experiment, the numerical examination of a number of physical quantities and the simplification of the theory, and the results are reported. (Kako, I.)

  14. Ultra-violet recombination continuum electron temperature measurements in a non-equilibrium atmospheric argon plasma

    International Nuclear Information System (INIS)

    Gordon, M.H.; Kruger, C.H.

    1991-01-01

    Emission measurements of temperature and electron density have been made downstream of a 50 kW induction plasma torch at temperatures and electron densities ranging between 6000 K and 8500 K and 10 to the 20th and 10 to the 21st/cu cm, respectively. Absolute and relative atomic line intensities, and absolute recombination continuum in both the visible and the UV were separately interpreted in order to characterize a recombining atmospheric argon plasma. Continuum measurements made in the UV at 270 nm were used to directly determine the kinetic electron temperature, independent of a Boltzmann equilibrium, assuming only that the electron velocity distribution is Maxwellian. The data indicate that a nonequilibrium condition exists in which the bound-excited and free electrons are nearly in mutual equilibrium down to the 4P level for electron densities as low as 2 x 10 to the 20th/cu m but that both are overpopulated with respect to the ground state due to finite recombination rates. 13 refs

  15. The effect of ethanol gas impurity on the discharge mode and discharge products of argon plasma jet at atmospheric pressure

    Science.gov (United States)

    Xia, Wenjie; Liu, Dingxin; Xu, Han; Wang, Xiaohua; Liu, Zhijie; Rong, Mingzhe; Kong, Michael G.

    2018-05-01

    Argon is a widely used working gas of plasmas, which is much cheaper than helium but on the other hand much more difficult to generate diffuse discharge at atmospheric pressure. In order to meet the application requirements, plenty of researches have been reported to facilitate the diffuse discharge happening for argon plasmas, and in this paper an approach of using ethanol gas (EtOH) impurity is investigated. The discharge characteristics of Ar + EtOH plasma jet are studied as a function of the applied voltage and the concentration of EtOH, from which the concentration of EtOH between ∼200 and ∼3300 parts per million (ppm) is determined necessary for the generation of diffuse discharge. Compared with the helium plasma jet in literature, it is deduced that the diffuse discharge is probably caused by the Penning ionization happening between the metastable argon and EtOH. The discharge products of Ar + EtOH (672 ppm) plasma jet are measured and the corresponding chemistry pathways are analyzed. About 20% of EtOH is decomposed via complex chemical reactions to form more than a dozen of neutral species, such as CH3CHO, CH3COOH, CO, H2O, and C n H2n+2 (n ≥ 3), and various kinds of ionic species, including C+, CH+, ArH+, {{{{O}}}2}-, CH3CH2O‑, etc.

  16. E-H mode transition in low-pressure inductively coupled nitrogen-argon and oxygen-argon plasmas

    International Nuclear Information System (INIS)

    Lee, Young Wook; Lee, Hye Lan; Chung, T. H.

    2011-01-01

    This work investigates the characteristics of the E-H mode transition in low-pressure inductively coupled N 2 -Ar and O 2 -Ar discharges using rf-compensated Langmuir probe measurements and optical emission spectroscopy (OES). As the ICP power increases, the emission intensities from plasma species, the electron density, the electron temperature, and the plasma potential exhibit sudden changes. The Ar content in the gas mixture and total gas pressure have been varied in an attempt to fully characterize the plasma parameters. With these control parameters varying, the changes of the transition threshold power and the electron energy distribution function (EEDF) are explored. In N 2 -Ar and O 2 -Ar discharges at low-pressures of several millitorr, the transition thresholds are observed to decrease with Ar content and pressure. It is observed that in N 2 -Ar plasmas during the transition, the shape of the EEDF changes from an unusual distribution with a flat hole near the electron energy of 3 eV in the E mode to a Maxwellian distribution in the H mode. However, in O 2 -Ar plasmas, the EEDFs in the E mode at low Ar contents show roughly bi-Maxwellian distributions, while the EEDFs in the H mode are observed to be nearly Maxwellian. In the E and H modes of O 2 -Ar discharges, the dissociation fraction of O 2 molecules is estimated using optical emission actinometry. During the E-H mode transition, the dissociation fraction of molecules is also enhanced.

  17. Calculations on charge state and energy loss of argon ions in partially and fully ionized carbon plasmas.

    Science.gov (United States)

    Barriga-Carrasco, Manuel D; Casas, David; Morales, Roberto

    2016-03-01

    The energy loss of argon ions in a target depends on their velocity and charge density. At the energies studied in this work, it depends mostly on the free and bound electrons in the target. Here the random-phase approximation is used for analyzing free electrons at any degeneracy. For the plasma-bound electrons, an interpolation between approximations for low and high energies is applied. The Brandt-Kitagawa (BK) model is employed to depict the projectile charge space distribution, and the stripping criterion of Kreussler et al. is used to determine its equilibrium charge state Q(eq). This latter criterion implies that the equilibrium charge state depends slightly on the electron density and temperature of the plasma. On the other hand, the effective charge Q(eff) is obtained as the ratio between the energy loss of the argon ion and that of the proton for the same plasma conditions. This effective charge Q(eff) is larger than the equilibrium charge state Q(eq) due to the incorporation of the BK charge distribution. Though our charge-state estimations are not exactly the same as the experimental values, our energy loss agrees quite well with the experiments. It is noticed that the energy loss in plasmas is higher than that in the same cold target of about, ∼42-62.5% and increases with carbon plasma ionization. This confirms the well-known enhanced plasma stopping. It is also observed that only a small part of this energy loss enhancement is due to an increase of the argon charge state, namely only ∼2.2 and 5.1%, for the partially and the fully ionized plasma, respectively. The other contribution is connected with a better energy transfer to the free electrons at plasma state than to the bound electrons at solid state of about, ∼38.8-57.4%, where higher values correspond to a fully ionized carbon plasma.

  18. Effect of Argon Plasma Treatment on Tribological Properties of UHMWPE/MWCNT Nanocomposites

    Directory of Open Access Journals (Sweden)

    Nitturi Naresh Kumar

    2016-08-01

    Full Text Available Ultra-high molecular weight polyethylene (UHMWPE is widely used in artificial joints in the replacement of knee, hip and shoulder that has been impaired as a result of arthritis or other degenerative joint diseases. The UHMWPE made plastic cup is placed in the joint socket in contact with a metal or ceramic ball affixed to a metal stem. Effective reinforcement of multi-walled carbon nanotubes (MWCNTs in UHMWPE results in improved mechanical and tribological properties. The hydrophobic nature of the nanocomposites surface results in lesser contact with biological fluids during the physiological interaction. In this project, we investigate the UHMWPE/MWCNTs nanocomposites reinforced with MWCNTs at different concentrations. The samples were treated with cold argon plasma at different exposure times. The water contact angles for 60 min plasma-treated nanocomposites with 0.0, 0.5, 1.0, 1.5, and 2.0 wt % MWCNTs were found to be 55.65°, 52.51°, 48.01°, 43.72°, and 37.18° respectively. Increasing the treatment time of nanocomposites has shown transformation from a hydrophobic to a hydrophilic nature due to carboxyl groups being bonded on the surface for treated nanocomposites. Wear analysis was performed under dry, and also under biological lubrication, conditions of all treated samples. The wear factor of untreated pure UHMWPE sample was reduced by 68% and 80%, under dry and lubricated conditions, respectively, as compared to 2 wt % 60 min-treated sample. The kinetic friction co-efficient was also noted under both conditions. The hardness of nanocomposites increased with both MWCNTs loading and plasma treatment time. Similarly, the surface roughness of the nanocomposites was reduced.

  19. Laser light scattering in a laser-induced argon plasma: Investigations of the shock wave

    Energy Technology Data Exchange (ETDEWEB)

    Pokrzywka, B. [Obserwatorium Astronomiczne na Suhorze, Uniwersytet Pedagogiczny, ulica Podchorazych 2, 30-084 Krakow (Poland); Mendys, A., E-mail: agata.mendys@uj.edu.pl [Instytut Fizyki im. M. Smoluchowskiego, Uniwersytet Jagiellonski, ulica Reymonta 4, 30-059 Krakow (Poland); Dzierzega, K.; Grabiec, M. [Instytut Fizyki im. M. Smoluchowskiego, Uniwersytet Jagiellonski, ulica Reymonta 4, 30-059 Krakow (Poland); Pellerin, S. [GREMI, site de Bourges, Universite d' Orleans, CNRS, rue Gaston Berger BP 4043, 18028 Bourges (France)

    2012-08-15

    Shock wave produced by a laser induced spark in argon at atmospheric pressure was examined using Rayleigh and Thomson scattering. The spark was generated by focusing a laser pulse from the second harmonic ({lambda} = 532 nm) of a nanosecond Nd:YAG laser using an 80 mm focal length lens, with a fluence of 2 kJ{center_dot}cm{sup -2}. Images of the spark emission were recorded for times between 30 ns and 100 {mu}s after the laser pulse in order to characterize its spatial evolution. The position of the shock wave at several instants of its evolution and for several plasma regions was determined from the Rayleigh-scattered light of another nanosecond Nd:YAG laser (532 nm, 40 J{center_dot}cm{sup -2} fluence). Simultaneously, Thomson scattering technique was applied to determine the electron density and temperature in the hot plasma core. Attempts were made to describe the temporal evolution of the shock wave within a self-similar model, both by the simple Sedov-Taylor formula as well as its extension deduced by de Izarra. The temporal radial evolution of the shock position is similar to that obtained within theory taking into account the counter pressure of the ambient gas. Density profiles just behind the shock front are in qualitative agreement with those obtained by numerically solving the Euler equations for instantaneous explosion at a point with counter pressure. - Highlights: Black-Right-Pointing-Pointer We investigated shock wave evolution by Rayleigh scattering method. Black-Right-Pointing-Pointer 2D map of shockwave position for several times after plasma generation is presented. Black-Right-Pointing-Pointer Shock wave evolution is not satisfactorily described within self-similar models. Black-Right-Pointing-Pointer Evolution of shock position similar to theory taking into account counter pressure. Black-Right-Pointing-Pointer Density profile behind the shock similar to numerical solution of Euler equations.

  20. Laser-induced fluorescence measurements of argon and xenon ion velocities near the sheath boundary in 3 ion species plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Yip, Chi-Shung; Hershkowitz, Noah [Department of Engineering Physics, University of Wisconsin-Madison, Madison, Wisconsin 53706 (United States); Severn, Greg [Department of Physics, University of San Diego, San Diego, California 92110 (United States); Baalrud, Scott D. [Department of Physics and Astronomy, University of Iowa, Iowa City, Iowa 52242 (United States)

    2016-05-15

    The Bohm sheath criterion is studied with laser-induced fluorescence in three ion species plasmas using two tunable diode lasers. Krypton is added to a low pressure unmagnetized DC hot filament discharge in a mixture of argon and xenon gas confined by surface multi-dipole magnetic fields. The argon and xenon ion velocity distribution functions are measured at the sheath-presheath boundary near a negatively biased boundary plate. The potential structures of the plasma sheath and presheath are measured by an emissive probe. Results are compared with previous experiments with Ar–Xe plasmas, where the two ion species were observed to reach the sheath edge at nearly the same speed. This speed was the ion sound speed of the system, which is consistent with the generalized Bohm criterion. In such two ion species plasmas, instability enhanced collisional friction was demonstrated [Hershkowitz et al., Phys. Plasmas 18(5), 057102 (2011).] to exist which accounted for the observed results. When three ion species are present, it is demonstrated under most circumstances the ions do not fall out of the plasma at their individual Bohm velocities. It is also shown that under most circumstances the ions do not fall out of the plasma at the system sound speed. These observations are also consistent with the presence of the instabilities.

  1. Characterization of an Atmospheric-Pressure Argon Plasma Generated by 915 MHz Microwaves Using Optical Emission Spectroscopy

    Directory of Open Access Journals (Sweden)

    Robert Miotk

    2017-01-01

    Full Text Available The paper presents the investigations of an atmospheric-pressure argon plasma generated at 915 MHz microwaves using the optical emission spectroscopy (OES. The 915 MHz microwave plasma was inducted and sustained in a waveguide-supplied coaxial-line-based nozzleless microwave plasma source. The aim of presented investigations was to estimate parameters of the generated plasma, that is, excitation temperature of electrons Texc, temperature of plasma gas Tg, and concentration of electrons ne. Assuming that excited levels of argon atoms are in local thermodynamic equilibrium, Boltzmann method allowed in determining the Texc temperature in the range of 8100–11000 K. The temperature of plasma gas Tg was estimated by comparing the simulated spectra of the OH radical to the measured one in LIFBASE program. The obtained Tg temperature ranged in 1200–2800 K. Using a method based on Stark broadening of the Hβ line, the concentration of electrons ne was determined in the range from 1.4 × 1015 to 1.7 × 1015 cm−3, depending on the power absorbed by the microwave plasma.

  2. Dynamics of ZnO laser produced plasma in high pressure argon

    International Nuclear Information System (INIS)

    Kaydashev, V.E.; Lunney, J.G.

    2011-01-01

    Pulsed laser deposition of ZnO in high pressure gas offers a route for the catalyst-free preparation of ZnO nanorods less than 10 nm in diameter. This paper describes the results of some experiments to investigate the laser plume dynamics in the high gas pressure (5 x 10 3 -10 4 Pa) regime used for PLD of ZnO nanorods. In this regime the ablation plume is strongly coupled to the gas and the plume expansion is brought to a halt within about 1 cm from the target. A 248 nm excimer laser was used to ablate a ceramic ZnO target in various pressures of argon. Time- and space-resolved UV/vis emission spectroscopy and Langmuir probe measurements were used to diagnose the plasma and follow the plume dynamics. By measuring the spatial profiles of Zn I and Zn II spectral lines it was possible to follow the propagation of the external and internal shock waves associated with the interaction of the ablation plume with the gas. The Langmuir probe measurements showed that the electron density was 10 9 -10 10 cm -3 and the electron temperature was several eV. At these conditions the ionization equilibrium is described by the collisional-radiative model. The plume dynamics was also studied for ZnO targets doped with elements which are lighter (Mg), comparable to (Ga), and heavier (Er) than Zn, to see if there is any elemental segregation in the plume.

  3. Comparison of explicit and effective models for calculating ionic populations in argon plasmas

    International Nuclear Information System (INIS)

    Abdallah, J. Jr.; Clark, R.E.H.

    1994-01-01

    Calculations have been performed to model the state populations of argon plasmas at electron densities at and above those required for the validity of coronal equilibrium. Both effective and explicit models have been used, and both are based on the same set of atomic cross sections. The effective model includes ground and singly excited states explicitly, while the effect of autoionizing states is accounted for by branching factors which describe their depopulation into the various non-autoionizing states. The explicit model considers both autoionizing and non-autoionizing states explicitly. The effective model requires a significantly reduced amount of computer time and memory. Good agreement between the two models can be obtained through moderate densities if the branching factors include electron density dependent terms which describe the collisional stabilization of each autoionizing state. The effective model breaks down as density is increased because the population of individual autoionizing states become significant. Results for both ionization balance and radiated power loss are presented. (Author)

  4. Precise measurements of neutral gas temperature using Fiber Bragg Grating sensor in Argon capacitively coupled plasmas

    Science.gov (United States)

    Han, Daoman; Liu, Zigeng; Liu, Yongxin; Peng, Wei; Wang, Younian

    2016-09-01

    Neutral gas temperature was measured using Fiber Bragg Grating sensor (FBGs) in capacitively coupled argon plasmas. Thermometry is based on the thermal equilibrium between the sensor and neutral gases, which is found to become faster with increasing pressure. It is also observed that the neutral gas temperature is higher than the room temperature by 10 120 °depending on the experiental conditions, and gas temperature shows significant non-uniformity in space. In addition, radial profiles of neutral temperature at different pressures, resemble these of ion density, obtained by a floating double probe. Specifically, at low pressure, neutral gas temperature and ion density peak at the center of the reactor, while the peak appears at the edge of the electrode at higher pressure. The neutral gas heating is mainly caused by the elastic collisions of Ar + with neutral gas atoms in the sheath region after Ar + gaining a certain energy. This work was supported by the National Natural Science Foundation of China (NSFC) (Grants No. 11335004, 11405018, and 61137005).

  5. Exploring the Effects of Argon Plasma Treatment on Plasmon Frequency and the Chemiresistive Properties of Polymer-Carbon Nanotube Metacomposite

    Directory of Open Access Journals (Sweden)

    Manuel Rivera

    2017-08-01

    Full Text Available Metacomposites, composite materials exhibiting negative permittivity, represent an opportunity to create materials with depressed plasmon frequency without the need to create complex structural geometries. Although many reports exist on the synthesis and characterizations of metacomposites, very few have ventured into exploring possible applications that could take advantage of the unique electrical properties of these materials. In this article, we report on the chemiresistive properties of a polymer-CNT metacomposite and explore how these are affected by Argon plasma treatment.

  6. Metastable argon atom density in complex argon/acetylene plasmas determined by means of optical absorption and emission spectroscopy

    International Nuclear Information System (INIS)

    Sushkov, Vladimir; Herrendorf, Ann-Pierra; Hippler, Rainer

    2016-01-01

    Optical emission and absorption spectroscopy has been utilized to investigate the instability of acetylene-containing dusty plasmas induced by growing nano-particles. The density of Ar(1s 5 ) metastable atoms was derived by two methods: tunable diode laser absorption spectroscopy and with the help of the branching ratio method of emitted spectral lines. Results of the two techniques agree well with each other. The density of Ar(1s 3 ) metastable atoms was also measured by means of optical emission spectroscopy. The observed growth instability leads to pronounced temporal variations of the metastable and other excited state densities. An analysis of optical line ratios provides evidence for a depletion of free electrons during the growth cycle but no indication for electron temperature variations. (paper)

  7. The Efficiency of Quartz Particles Evaporation in the Argon Plasma Flow of the RF Inductively Coupled Plasma Torch

    Directory of Open Access Journals (Sweden)

    Yu. M. Grishin

    2017-01-01

    Full Text Available Owing to high-power density and high-purity plasma, a RF inductively coupled plasma torch (ICPT is widely used both in research laboratory and in industry. The potential RF ICPT application areas are powders spheroidisation, waste treatment, thermal spraying, etc.In the last decade the investigation was focused on the treatment processes of quartz into polycrystalline silicon. An analysis of these results has shown that the increasing productivity and producing high-purity silicon can be achieved only when using the electrodeless radio-frequency induction plasma torches and in case the optimum conditions for evaporation of SiO2solid particles are realized.Optimization of the RF ICPT design and power parameters calls for a wide range of computational studies. In spite of the fact that to date a large number of efforts to calculate the evaporation efficiency of powder materials have been made, a number of issues, as applied to the problem of obtaining silicon, require further research.In this paper, we present the results of a two-dimensional numerical simulation of the heating and evaporation of quartz particles in the RF ICPT channel with axial flow of gases. The main aim is to determine how the axial position of the central tube (through which the particles are injected into the discharge zone, the dispersion of the quartz powder, the amplitude of the discharge current (and, respectively, flow regimes impact on the evaporation efficiency of quartz particles.The paper presented the numerical modeling results of heating and evaporation processes of quartz particles supplied by transporting gas to the RF ICPT channel with axial gas flow (argon. Defined the impact of the axial position of the central tube, the plasma flow regime, the discharge current, the flow rate of transporting gas, and other parameters on the evaporation efficiency of quartz particles.It is shown that the evaporation efficiency of particles reaches its maximum when their

  8. Pathogen inactivation in fresh frozen plasma using riboflavin and ultraviolet light: Effects on plasma proteins and coagulation factor VIII

    Directory of Open Access Journals (Sweden)

    Stanojković Zoran

    2011-01-01

    Full Text Available Background/Aim. Riboflavin (vitamin B2 activated by ultraviolet (UV light, produces active oxygen which damages cell membrane and prevents replication of the carrier of diseases (viruses, bacteria, protozoa in all blood products. The aim of this study was to establish the influence of the process of photo inactivation in pathogens using riboflavin and UV rays on the concentration of coagulation factor VIII:C (FVIII:C and proteins in plasma that were treated before freezing. Methods. The examination included 20 units of plasma, separated from whole blood donated by voluntary blood donors around 6 hours from the moment of collection. The units were pooled and separated in to two groups: one consisted of 10 control units and the other of 10 experimental units. Experimental units of the plasma were treated by riboflavin (35 mL and UV rays (6.24 J/mL, 265-370 nm on Mirasol aparature (Caridian BCT Biotechnologies, USA in approximate duration of 6 minutes. Furthermore, 35 mL of saline solution was added to the control plasma. One sample for examining was taken from the control plasma (KG and two residual were taken from experimental plasma after the addition of riboflavin either before (EG1 or post illumination (EG2. Results. Comparing the mean values of FVIII:C (% we noticed statistically significantly higher level in the EG1 group than in the EG2 group (65.00 ± 4.52 vs 63.20 ± 4.73; t = 4.323, p = 0.002, while between the KG and experimental groups (EG1 and EG2 there was no statistically significant difference in the concentration of FVIII:C. There was a statistically significant decrease of albumin concentration (g/L in the EG2 group comparing to the KG (33.35 ± 0.94 vs 31.94 ± 0.84; t = 3.534, p = 0.002, but there was no mentioned difference in albumin concentration between the KG and the EG1, so as between the EG1 and the EG2. Conclusion. Plasma inactivated by riboflavin and UV rays (Mirasol PRT sistem, Caridian BCT, USA keeps all the

  9. Influence of centrifuge brake on residual platelet count and routine coagulation tests in citrated plasma.

    Science.gov (United States)

    Daves, Massimo; Giacomuzzi, Katia; Tagnin, Enrico; Jani, Erika; Adcock Funk, Dorothy M; Favaloro, Emmanuel J; Lippi, Giuseppe

    2014-04-01

    Sample centrifugation is an essential step in the coagulation laboratory, as clotting tests are typically performed on citrated platelet (PLT) poor plasma (PPP). Nevertheless, no clear indication has been provided as to whether centrifugation of specimens should be performed with the centrifuge brake set to on or off. Fifty consecutive sodium citrate anticoagulated samples were collected and divided into two aliquots. The former was centrifuged as for Clinical Laboratory Standards Institute (CLSI) guidelines with the centrifuge brake set to on, whereas the latter was centrifuged again as for CLSI guidelines, but with the brake set to off. In the PPP of all samples, a PLT count was performed, followed by the analysis of activated partial thromboplastin time (APTT), prothrombin time (PT) and fibrinogen (FBG). The PLT count after samples centrifugation was substantially reduced, either with centrifuge brake set to on or off (5 ± 1 versus 3 ± 1 × 10/l; P = 0.009). The frequency of samples exceeding a PLT count less than 10 × 10/l was nearly double in samples centrifuged with the brake on than in those with the brake off (14 versus 8%; P centrifuge brake set to on (mean bias 0.2 s; P centrifuge brake set to on (mean bias 0.29 g/l; P centrifugation for routine coagulation testing should be preferably performed with the centrifuge brake set to off for providing a better quality specimen.

  10. Reconstruction of the time-averaged sheath potential profile in an argon RF plasma using the ion energy distribution

    International Nuclear Information System (INIS)

    Fivaz, M.; Brunner, S.; Schwarzenbach, W.; Howling, A.A.; Hollenstein, C.

    1994-10-01

    Charge-exchange collisions and radio-frequency excitation combine to give peaks in the ion energy distribution measured at the ground electrode of an argon plasma in a capacitive reactor. These peaks are used as a diagnostic to reconstruct the profile of the time-averaged potential in the sheath. Particle-In-Cell simulations show that the method is accurate. The method is applied to investigate the sheath thickness as a function of excitation frequency at constant plasma power. The time-averaged potential is found to be parabolic in both experimental measurements and numerical simulation. (author) 6 figs., 1 tab., 15 refs

  11. A study of the plasma electronegativity in an argon-oxygen pulsed-dc sputter magnetron

    International Nuclear Information System (INIS)

    You, S D; Dodd, R; Edwards, A; Bradley, J W

    2010-01-01

    Using Langmuir probe-assisted laser photodetachment, the temporal evolution of the O - density was determined in the bulk plasma of a unipolar pulsed-dc magnetron. The source was operated in reactive mode, at a fixed nominal on-time power of 100 W, sputtering Ti in argon-oxygen atmospheres at 1.3 Pa pressure, but over a variation of duty cycles from 5% to 50% and oxygen partial pressures of 10% and 50% of the total pressure. In the plasma on-time, for all duty cycles the negative ion density (n - ) rises marginally reaching values typically less than 2 x 10 15 m -3 with negative ion-to-electron density ratios, α - falls by about 20-30% as fast O - species created at the cathode exit the system. This is followed by a rapid rise in n - to values at least 2 or 3 times that in the on-time. The rate of rise of n - and its maximum value both increase with decreasing duty cycle. In the off-time, the electron density falls rapidly (initial decay rates of several tens of μs), and therefore the afterglow plasma becomes highly electronegative, with α reaching 4.6 and 14.4 for 10% and 50% oxygen partial pressure, respectively. The rapid rise in n - in the afterglow (in which the electron temperature falls from about 5 to 0.5 eV) is attributed to the dissociative attachment of highly excited oxygen metastables, which themselves are created in the pulse on-time. At the lowest duty of 5%, the long-term O - decay times are several hundred μs. Langmuir probe characteristics show the clear signature that negative ions dominate over the electrons in the off-time. From the ion and electron saturation current ratios, α has been estimated in some chosen cases and found to agree within a factor between 2 and 10 with those obtained more directly from the photodetachment method.

  12. Single-shot Thomson scattering on argon plasmas created by the Microwave Plasma Torch; evidence for a new plasma class

    NARCIS (Netherlands)

    Mullen, van der J.J.A.M.; Sande, van de M.J.; Vries, de N.; Broks, B.H.P.; Iordanova, E.I.; Gamero, A.; Torres, J.; Sola, A.

    2007-01-01

    To determine the fine-structure size of plasmas created by a Microwave Plasma Torch (MPT), single-shot Thomson scattering (TS) measurements were performed. The aim was to find a solution for the long-standing discrepancy between experiments and Global Plasma Models (GPMs). Since these GPMs are based

  13. A spectroscopic method to determine the electron temperature of an argon surface wave sustained plasmas using a collision radiative model

    Energy Technology Data Exchange (ETDEWEB)

    Vries, N de; Iordanova, E; Hartgers, A; Veldhuizen, E M van; Donker, M J van der; Mullen, J J A M van der [Department of Applied Physics, Eindhoven University of Technology, PO Box 513, 5600 MB Eindhoven (Netherlands)

    2006-10-07

    A method is presented to determine the electron temperature in a low pressure argon plasma using emission spectroscopic measurements and a collisional radiative (CR) model. Absolute line intensity measurements are made in order to construct the atomic state distribution function. In addition to the excited states, the ground state density is also taken into account. Because of this, the excitation temperature can be determined with high precision. A CR-model has been used to determine the degree of equilibrium departure and to obtain the relationship between the excitation temperature and the electron temperature. This method is applied to a microwave plasma which has been generated inside a quartz tube using a surfatron device. The densities of argon levels close to the continuum are used to get an estimated value of the electron density. These values are used as input data for the CR-model. For an argon pressure of 6 mbar, the 4p level densities vary between 8 x 10{sup 14} and 6 x 10{sup 15} m{sup -3}. Using the estimated values for the electron density, between 2 x 10{sup 19} and 3 x 10{sup 19} m{sup -3}, the electron temperature was found to range between 1.15 and 1.20 eV. An extensive error analysis showed that the relative error in the electron temperature is less than 6%.

  14. A spectroscopic method to determine the electron temperature of an argon surface wave sustained plasmas using a collision radiative model

    International Nuclear Information System (INIS)

    Vries, N de; Iordanova, E; Hartgers, A; Veldhuizen, E M van; Donker, M J van der; Mullen, J J A M van der

    2006-01-01

    A method is presented to determine the electron temperature in a low pressure argon plasma using emission spectroscopic measurements and a collisional radiative (CR) model. Absolute line intensity measurements are made in order to construct the atomic state distribution function. In addition to the excited states, the ground state density is also taken into account. Because of this, the excitation temperature can be determined with high precision. A CR-model has been used to determine the degree of equilibrium departure and to obtain the relationship between the excitation temperature and the electron temperature. This method is applied to a microwave plasma which has been generated inside a quartz tube using a surfatron device. The densities of argon levels close to the continuum are used to get an estimated value of the electron density. These values are used as input data for the CR-model. For an argon pressure of 6 mbar, the 4p level densities vary between 8 x 10 14 and 6 x 10 15 m -3 . Using the estimated values for the electron density, between 2 x 10 19 and 3 x 10 19 m -3 , the electron temperature was found to range between 1.15 and 1.20 eV. An extensive error analysis showed that the relative error in the electron temperature is less than 6%

  15. Optically thick model for radiative and collisional effects in nonequilibrium argon plasma flows in a circular tube

    International Nuclear Information System (INIS)

    Shirai, Hiroyuki; Tabei, Katsuine; Koaizawa, Hisashi.

    1984-01-01

    Experimental and theoretical studies were made to gain a deeper understanding of the radiative properties of nonequilibrium argon plasma flows in a circular tube. The self-absorption effects were taken into account as rigorously as possible. Experimentally, the radial profiles of the population densities of argon atoms at the excited 4s, 4p, 5p, and 5d levels were obtained from the lateral distributions of the absolute intensities of ArI spectral lines originating from these levels. On the other hand, theoretical profiles of the population densities for the same levels were calculated based on the optically thick model for collisional and radiative processes proposed by Bates et al. and experimentally measured atom temperature, electron temperature, electron density and gas pressure. Comparison of the experimental and theoretical results showed a reasonably good agreement and the importance of the self-absorption effects. (author)

  16. Excitation mechanism for nickel and argon lines emitted by radio-frequency glow discharge plasma associated with bias current introduction

    International Nuclear Information System (INIS)

    Kodama, Kenji; Wagatsuma, Kazuaki

    2004-01-01

    The introduction of d.c. bias current to an r.f. glow discharge plasma led to enhancement in the intensity of particular emission lines. In order to investigate the excitation mechanism, a large number of nickel emission lines was measured with and without the bias-current introduction. Emission intensities of nickel atomic lines were predominantly elevated by conducting bias current, especially when the emission lines have an excitation energy of approximately 5 eV. This phenomenon could be explained from the additional excitation through collisions with the introduced electrons having kinetic energies favorable for the excitation of such nickel atomic lines. However, this additional excitation mechanism was less effective for excited states of nickel ion, argon atom and argon ion, because their excitation energies were fairly high compared with the excitation energies of Ni atomic lines

  17. Removal and sterilization of biofilms and planktonic bacteria by microwave-induced argon plasma at atmospheric pressure

    International Nuclear Information System (INIS)

    Lee, Mi Hee; Park, Bong Joo; Jin, Soo Chang; Kim, Dohyun; Kim, Jungsung; Park, Jong-Chul; Han, Inho; Hyun, Soon O; Chung, Kie-Hyung

    2009-01-01

    Microbial biofilms are a functional matrix of microbial cells, enveloped in polysaccharides, enzymes and virulence factors secreted by them that can develop on indwelling medical devices and biomaterials. Plasma sterilization has been widely studied in recent years for biological applications. In this study, we evaluated the possibility of removal and anti-recovery of biofilms by microwave-induced argon plasma at atmospheric pressure. We observed that all bacterial biofilms formatted by Gram-negative and Gram-positive bacteria are removed in less than 20 s, and the growth inhibitions of planktonic bacteria within biofilms are also confirmed by plasma exposure for 5 s. These results suggest that our plasma system can be applied to medical and biological fields where the removal of biofilms and their debris is required.

  18. Surface roughening of silicon, thermal silicon dioxide, and low-k dielectric coral films in argon plasma

    International Nuclear Information System (INIS)

    Yin Yunpeng; Sawin, Herbert H.

    2008-01-01

    The surface roughness evolutions of single crystal silicon, thermal silicon dioxide (SiO 2 ), and low dielectric constant film coral in argon plasma have been measured by atomic force microscopy as a function of ion bombardment energy, ion impingement angle, and etching time in an inductively coupled plasma beam chamber, in which the plasma chemistry, ion energy, ion flux, and ion incident angle can be adjusted independently. The sputtering yield (or etching rate) scales linearly with the square root of ion energy at normal impingement angle; additionally, the angular dependence of the etching yield of all films in argon plasma followed the typical sputtering yield curve, with a maximum around 60 deg. -70 deg. off-normal angle. All films stayed smooth after etching at normal angle but typically became rougher at grazing angles. In particular, at grazing angles the rms roughness level of all films increased if more material was removed; additionally, the striation structure formed at grazing angles can be either parallel or transverse to the beam impingement direction, which depends on the off-normal angle. More interestingly, the sputtering caused roughness evolution at different off-normal angles can be qualitatively explained by the corresponding angular dependent etching yield curve. In addition, the roughening at grazing angles is a strong function of the type of surface; specifically, coral suffers greater roughening compared to thermal silicon dioxide

  19. Time-dependent effects of low-temperature atmospheric-pressure argon plasma on epithelial cell attachment, viability and tight junction formation in vitro

    International Nuclear Information System (INIS)

    Hoentsch, Maxi; Barbara Nebe, J; Von Woedtke, Thomas; Weltmann, Klaus-Dieter

    2012-01-01

    The application of physical plasma to living tissues is expected to promote wound healing by plasma disinfection and stimulation of tissue regeneration. However, the effects of plasma on healthy cells must be studied and understood. In our experiments we used an argon plasma jet (kINPen®09) to gain insights into time-dependent plasma effects on cell attachment, viability and tight junction formation in vitro. Murine epithelial cells mHepR1 were suspended in complete cell culture medium and were irradiated with argon plasma (direct approach) for 30, 60 and 120 s. Suspecting that physical plasma may exert its effect via the medium, cell culture medium alone was first treated with argon plasma (indirect approach) and immediately afterwards, cells were added and also cultured for 24 h. Cell morphology and vitality were verified using light microscopy and an enzyme-linked immunosorbent assay. Already after 30 s of treatment the mHepR1 cells lost their capability to adhere and the cell vitality decreased with increasing treatment time. Interestingly, the same inhibitory effect was observed in the indirect approach. Furthermore, the argon plasma-treated culture medium-induced large openings of the cell's tight junctions, were verified by the zonula occludens protein ZO-1, which we observed for the first time in confluently grown epithelial cells. (paper)

  20. Using the Pairs of Lines Broadened by Collisions with Neutral and Charged Particles for Gas Temperature Determination of Argon Non-Thermal Plasmas at Atmospheric Pressure

    Directory of Open Access Journals (Sweden)

    Cristina Yubero

    2017-10-01

    Full Text Available The spectroscopic method for gas temperature determination in argon non-thermal plasmas sustained at atmospheric pressure proposed recently by Spectrochimica Acta Part B 129 14 (2017—based on collisional broadening measurements of selected pairs of argon atomic lines, has been applied to other pairs of argon atomic lines, and the discrepancies found in some of these results have been analyzed. For validation purposes, the values of the gas temperature obtained using the different pairs of lines have been compared with the rotational temperatures derived from the OH ro-vibrational bands, using the Boltzmann-plot technique.

  1. Urinary nickel: measurement of exposure by inductively coupled plasma argon emission spectrometry.

    Science.gov (United States)

    Koizumi, Chisato; Usuda, Kan; Hayashi, Satsuki; Dote, Tomotaro; Kono, Koichi

    2004-09-01

    Nickel is a rare earth metal and is widely used in modern industry. Its overexposure in human beings can provoke significant effects including lung, cardiovascular and kidney diseases. As an index of occupational exposure, urine is widely used for the monitoring of nickel concentration because it is a minimally invasive method. Recent studies have used atomic absorption spectrometry to measure nickel concentration. In this study, we introduced novel inductively coupled plasma argon emission spectrometry (ICPAES) which enables us to measure multiple elements simultaneously with smaller volume and with lower detection limits compared to conventional atomic absorption emission spectrometry, and we established the new measuring method by determining the appropriate wavelengths for nickel concentration. Furthermore, using the established new measuring method, we investigated the correlation between a single oral administration of nickel and urine elimination in rats. As a result, different concentrations of nickel standard solutions were measured by ICPAES, and among five specific wavelengths of nickel, 221.647 and 231.604 nm were chosen because they had the highest inclines of both signal to background ratio and emission intensity in simple linear regression analysis. Next, by using healthy human urine samples that had not been exposed to nickel, 231.604 nm was determined to be the most appropriate wavelength because it did not present abnormal intensity due to obstacle wavelength. Male Wistar rats received an oral administration of nickel ranging from 0.025 to 250 mg/kg, which is equivalent to 0.0015 - 15% of LD50, and during the following 24 h, urine samples were collected and the nickel concentration was measured by ICPAES. With a single oral administration of nickel, there was an increase in urine nickel concentration in a dose-dependent manner and the appropriate equation was developed. Acute renal failure was not observed in this dosage of oral nickel

  2. The effect of radio-frequency self bias on ion acceleration in expanding argon plasmas in helicon sources

    Science.gov (United States)

    Wiebold, Matthew D.

    Time-averaged plasma potential differences up to ˜ 165 V over several hundred Debye lengths are observed in low pressure (pn floating potential for argon (Vp ≈ 5kTe/e). In the capacitive mode, the ion acceleration is not well described by an ambipolar relation. The accelerated population decay is consistent with that predicted by charge-exchange collisions. Grounding the upstream endplate increases the self-bias voltage compared to a floating endplate. In the inductive and helicon modes, the ion acceleration more closely follows an ambipolar relation, a result of decreased capacitive coupling due to the decreased RF skin depth. The scaling of the potential gradient with the argon flow rate, magnetic field and RF power are investigated, with the highest potential gradients observed for the lowest flow rates in the capacitive mode. The magnitude of the self-bias voltage agrees well with that predicted for RF sheaths. Use of the self-bias effect in a plasma thruster is explored, possibly for a low thrust, high specific impulse mode in a multi-mode helicon thruster. This work could also explain similar potential gradients in expanding helicon plasmas that are ascribed to double layer formation in the literature.

  3. Dentin surface treatment using a non-thermal argon plasma brush for interfacial bonding improvement in composite restoration

    Science.gov (United States)

    Ritts, Andy Charles; Li, Hao; Yu, Qingsong; Xu, Changqi; Yao, Xiaomei; Hong, Liang; Wang, Yong

    2010-01-01

    The objective of this study is to investigate the treatment effects of non-thermal atmospheric gas plasmas on dentin surfaces for composite restoration. Extracted unerupted human third molars were used by removing the crowns and etching the exposed dentin surfaces with 35% phosphoric acid gel. The dentin surfaces were treated by using a non-thermal atmospheric argon plasma brush for various durations. The molecular changes of the dentin surfaces were analyzed using FTIR/ATR and an increase in carbonyl groups on dentin surfaces was detected with plasma treated dentin. Adper Single Bond Plus adhesive and Filtek Z250 dental composite were applied as directed. To evaluate the dentin/composite interfacial bonding, the teeth thus prepared were sectioned into micro-bars as the specimens for tensile test. Student Newman Keuls tests showed that the bonding strength of the composite restoration to peripheral dentin was significantly increased (by 64%) after 30 s plasma treatment. However, the bonding strength to plasma treated inner dentin did not show any improvement. It was found that plasma treatment of peripheral dentin surface up to 100 s gave an increase in interfacial bonding strength, while a prolong plasma treatment of dentin surfaces, e.g., 5 min treatments, showed a decrease in interfacial bonding strength. PMID:20831586

  4. Plasma triacylglycerol and coagulation factor concentrations predict the anticoagulant effect of dietary fish oil in overweight subjects

    DEFF Research Database (Denmark)

    Vanschoonbeek, Kristof; Feijge, Marion A H; Saris, Wim H M

    2007-01-01

    fish-oil effects. In study 1, 54 overweight subjects consumed 3.1 g (n-3) PUFA daily. In study 2, which involved 42 overweight patients with type 2 diabetes, 20 subjects consumed (n-3) PUFA, whereas 22 others ingested a preparation rich in (n-6) PUFA. Tissue factor-induced thrombin generation (thrombin...... potential) was determined as an integrated measure of plasma coagulant activity. In both studies, multivariate analysis indicated a strong clustering of fasting concentrations of triacylglycerols, prothrombin, factor V, factor VII, and factor X with one another at baseline. This cluster of factors......-induced lowering of triacylglycerol and coagulation factor V, VII, and X concentrations, and thrombin generation. We conclude that high fasting triacylglycerol concentrations predict high procoagulant activity and a lowering of thrombin potential with dietary fish oil....

  5. Demonstration of high-performance p-type tin oxide thin-film transistors using argon-plasma surface treatments

    Science.gov (United States)

    Bae, Sang-Dae; Kwon, Soo-Hun; Jeong, Hwan-Seok; Kwon, Hyuck-In

    2017-07-01

    In this work, we investigated the effects of low-temperature argon (Ar)-plasma surface treatments on the physical and chemical structures of p-type tin oxide thin-films and the electrical performance of p-type tin oxide thin-film transistors (TFTs). From the x-ray photoelectron spectroscopy measurement, we found that SnO was the dominant phase in the deposited tin oxide thin-film, and the Ar-plasma treatment partially transformed the tin oxide phase from SnO to SnO2 by oxidation. The resistivity of the tin oxide thin-film increased with the plasma-treatment time because of the reduced hole concentration. In addition, the root-mean-square roughness of the tin oxide thin-film decreased as the plasma-treatment time increased. The p-type oxide TFT with an Ar-plasma-treated tin oxide thin-film exhibited excellent electrical performance with a high current on-off ratio (5.2 × 106) and a low off-current (1.2 × 10-12 A), which demonstrates that the low-temperature Ar-plasma treatment is a simple and effective method for improving the electrical performance of p-type tin oxide TFTs.

  6. Plasma and BIAS Modeling: Self-Consistent Electrostatic Particle-in-Cell with Low-Density Argon Plasma for TiC

    Directory of Open Access Journals (Sweden)

    Jürgen Geiser

    2011-01-01

    processes. In this paper we present a new model taken into account a self-consistent electrostatic-particle in cell model with low density Argon plasma. The collision model are based of Monte Carlo simulations is discussed for DC sputtering in lower pressure regimes. In order to simulate transport phenomena within sputtering processes realistically, a spatial and temporal knowledge of the plasma density and electrostatic field configuration is needed. Due to relatively low plasma densities, continuum fluid equations are not applicable. We propose instead a Particle-in-cell (PIC method, which allows the study of plasma behavior by computing the trajectories of finite-size particles under the action of an external and self-consistent electric field defined in a grid of points.

  7. Effect of voltage shape of electrical power supply on radiation and density of a cold atmospheric argon plasma jet

    Directory of Open Access Journals (Sweden)

    F Sohbatzadeh

    2017-02-01

    Full Text Available In this work, we investigated generating argon cold plasma jet at atmospheric pressure based on dielectric barrier discharge configuration using three electrical power supplies of sinusoidal, pulsed and saw tooth high voltage shapes at 8 KHZ. At first; we describe the electronic circuit features for generating high voltage (HV wave forms including saw tooth, sinusoidal and pulsed forms. Then, we consider the effect of voltage shape on the electrical breakdown. Relative concentrations of chemical reactive species such as Oxygen, atomic Nitrogen and OH were measured using optical emission spectroscopy. Using a simple numerical model, we showed a HV with less rise time increases electron density, therefore a cold plasma jet can be produced with a minimal consumption electrical power

  8. Observation of dielectronic satellites in the K-spectrum of argon ions in plasma produced by femtosecond laser pulses

    International Nuclear Information System (INIS)

    Magunov, A.I.; Faenov, A.Ya.; Skobelev, I.Yu.; Pikuz, T.A.; Biemont, E.; Quinet, P.; Blasco, F.; Bonte, C.; Dorchies, F.; Caillaud, T.; Salin, F.; Stenz, C.

    2002-01-01

    The satellite structure of 1s2p 1,3 P 1 -1s 21 S 0 lines of the He-like argon ion in plasma produced by a 45-fs laser pulse in a gas-jet cluster target is measured with a high spectral resolution. Radiation transitions 2p → 1s from autoionizing states (AISs) are detected for ions ranging from Li-like to F-like. The spectrum observed is theoretically simulated with the use of the spectroscopic data for the AISs of multicharged ions obtained within the multiconfiguration relativistic Hartree-Fock method. Good agreement with experimental data is obtained when the main population channels of these states are taken into account for typical values of cluster-target plasma parameters

  9. Thomson scattering on argon surfatron plasmas at intermediate pressures: Axial profiles of the electron temperature and electron density

    International Nuclear Information System (INIS)

    Palomares, J.M.; Iordanova, E.; Veldhuizen, E.M. van; Baede, L.; Gamero, A.; Sola, A.; Mullen, J.J.A.M. van der

    2010-01-01

    The axial profiles of the electron density n e and electron temperature T e of argon surfatron plasmas in the pressure range of 6-20 mbar and microwave power between 32 and 82 W have been determined using Thomson Scattering of laser irradiation at 532 nm. For the electron density and temperature we found values in the ranges 5 x 10 18 e 19 m -3 and 1.1 e e and T e down to 8% and 3%, respectively. It is found that n e decreases in the direction of the wave propagation with a slope that is nearly constant. The slope depends on the pressure but not on the power. Just as predicted by theories we see that increasing the power leads to longer plasma columns. However, the plasmas are shorter than what is predicted by theories based on the assumption that for the plasma-wave interaction electron-atom collisions are of minor importance (the so-called collisionless regime). The plasma vanishes long before the critical value of the electron density is reached. In contrast to what is predicted by the positive column model it is found that T e does not stay constant along the column, but monotonically increases with the distance from the microwave launcher. Increases of more than 50% over 30 cm were found.

  10. Decomposition of 2-((2-methoxyphenyl)diazenyl)benzene-1,3,5-triol molecule by an argon plasma jet

    Science.gov (United States)

    Tanışlı, Murat; Taşal, Erol

    2018-05-01

    In this study, we have presented the effects of the argon plasma on a 2-((2-methoxyphenyl)diazenyl)benzene-1,3,5-triol molecule—AZO compound (abbreviated as 2MDB)—under atmospheric pressure. In order to do this, the validated molecule has been considered and plasma has been used to modify it. The atmospheric pressure plasma jet system was specially designed for performing decomposing processes of the 2MDB molecule. The characterizations before and after the application of plasma—which takes only 3 minutes under atmospheric pressure conditions, to dissolve the 2MDB molecule in ethanol and methanol solutions—were examined using the Fourier transform infrared and Ultraviolet-Visible (UV-Vis) spectroscopies. After the plasma treatment, the molecule was broken at -C-N=N-C-C bond. Accurate and important changes are seen clearly from the results. In addition, according to UV-Vis spectra, π-π* electronic transitions related to -N=N- AZO bridge for the 2MDB molecule in polar-aprotic solvents such as ethanol and methanol were recorded as strong transitions. The new photoproducts such as -C-N-N=C and C=O were obtained from the 2MDB molecule.

  11. Preliminary study of haemostasis in irradiated-enterectomised dog. Primary haemostasis, coagulation, plasma factors exploration

    International Nuclear Information System (INIS)

    Dubos, M.; Niaussat, P.M.; Neveux, Y.; Nguyen, T.L.; Drouet, J.; Bac, P.

    Some hematological changes due to the combined effects of ionizing radiations and surgery were studied in dogs irradiated at 250, 300 and 350R. A constant hemorrhagic syndrome was observed with an impairment of the platelets functions and a depletion of several coagulation factors [fr

  12. Study of emission of a volume nanosecond discharge plasma in xenon, krypton and argon at high pressures

    International Nuclear Information System (INIS)

    Baksht, E Kh; Lomaev, Mikhail I; Rybka, D V; Tarasenko, Viktor F

    2006-01-01

    The emission properties of a volume nanosecond discharge plasma produced in xenon, krypton and argon at high pressures in a discharge gap with a cathode having a small radius of curvature are studied. Spectra in the range 120-850 nm and amplitude-time characteristics of xenon emission at different regimes and excitation techniques are recorded and analysed. It is shown that upon excitation of the volume discharge initiated by a beam of avalanche electrons, at least 90% of the energy in the spectral range 120-850 nm is emitted by xenon dimers. For xenon at a pressure of 1.2 atm, ∼45 mJ of the spontaneous emission energy was obtained in the full solid angle in a pulse with the full width at half-maximum ∼130 ns. (laser applications and other topics in quantum electronics)

  13. Surface grafting of styrene on polypropylene fibers by argon plasma and its adsorption-regeneration of BTX

    Science.gov (United States)

    Xu, J. J.; Guo, M. L.; Chen, Q. G.; Lian, Z. Y.; Wei, W. J.; Luo, Z. W.; Xie, G.; Chen, H. N.; Dong, K.

    2017-08-01

    Active macromolecular free radicals were generated on polypropylene (PP) fibers surfaces by argon (Ar) plasma irradiation, then, PP surface modified fibers (PP-g-St fibers) were prepared by in-situ grafting reaction of styrene monomers (St). Effects of reaction parameters on grafting percentage were studied and adsorption capacities of PP-g-St fibers for benzene, toluene and xylene (BTX) were evaluated. Afterwards, regeneration adsorption efficiencies after maximum adsorption were explored. The results indicated that the optimum input power, irradiation time and grafting reaction time are 90 W, 3 min and 3 h respectively and the grafting percentage of St reached 5.7 %. The adsorption capacities of PP-g-St fibers towards toluene and xylene emulsions and solutions in water increased by 336.89 % and 344.57 % respectively, compared to pristine PP fibers. In addition, regeneration adsorption efficiencies of modified fibers remained > 90 % after six cycles of regeneration-adsorption experiments, which showed excellent regeneration ability.

  14. Zinc, lead and copper in human teeth measured by induced coupled argon plasma atomic emission spectroscopy (ICP-AES)

    Energy Technology Data Exchange (ETDEWEB)

    Chew, L.T.; Bradley, D.A. E-mail: D.A.Bradley@exeter.ac.uk; Mohd, Y.; Jamil, M

    2000-11-15

    Inductively Coupled Argon Plasma Atomic Emission Spectroscopy (ICP-AES) has been used to determine Pb, Zn and Cu levels in 47 exfoliated human teeth (all of which required extraction for orthodontic reasons). Lead concentrations for the group were 1.7 {mu}g (g tooth mass){sup -1} to 40.5 {mu}g (g tooth mass){sup -1}, with a median of 9.8 {mu}g (g tooth mass){sup -1}. A median lead level in excess of the group value was found for the teeth of six lorry drivers who were included in the study. A more significant enhancement was found for the seven subjects whose age was in excess of 60 years. The median values for Zn and Cu were 123.0 and 0.6 {mu}g (g tooth mass){sup -1} respectively. Present values for tooth-Zn are lower than published data for other ethnic groups.

  15. Heat and momentum transfer from an atmospheric argon hydrogen plasma jet to spherical particles

    International Nuclear Information System (INIS)

    Vaessen, P.H.M.

    1984-01-01

    In this thesis the author describes the energy and momentum transfer from the plasma jet to the spray particles. This is done both experimentally and theoretically. Also the internal energy process of the recombining plasma is discussed. All elastic and inelastic collisional and radiative processes, as well as transport effects within the plasma are considered. In the next section, the so called passive spectroscopy is treated. It describes the diagnostics of electron density and temperature measurement, as well as the investigation on heat content of the particles. Spatially resolved electron density and temperature profiles are presented. Next, the active spectroscopy, i.e. the laser Doppler anemometer is dealt with. With this diagnostic, axial spray-particle velocities inside the plasma jet were determined. The author also presents heat and momentum transfer modelling of the plasma, related to the plasma particle interaction. Finally, a one dimensional model verification is made, using the experimentally determined particle velocity and plasma temperature profiles. (Auth.)

  16. Room-temperature atomic layer deposition of ZrO{sub 2} using tetrakis(ethylmethylamino)zirconium and plasma-excited humidified argon

    Energy Technology Data Exchange (ETDEWEB)

    Kanomata, K. [Graduate School of Science and Engineering, Yamagata University, 4-3-16 Jonan, Yonezawa 992-8510 (Japan); Japan Society for the Promotion of Science, 5-3-1 Kojimachi, Chiyoda-ku, Tokyo 102-0083 (Japan); Tokoro, K.; Imai, T.; Pansila, P.; Miura, M.; Ahmmad, B.; Kubota, S.; Hirahara, K. [Graduate School of Science and Engineering, Yamagata University, 4-3-16 Jonan, Yonezawa 992-8510 (Japan); Hirose, F., E-mail: fhirose@yz.yamagata-u.ac.jp [Graduate School of Science and Engineering, Yamagata University, 4-3-16 Jonan, Yonezawa 992-8510 (Japan)

    2016-11-30

    Highlights: • RT-ALD of ZrO{sub 2} is developed using TEMAZ and plasma-excited humidified argon. • The plasma-excited humidified argon is effective in oxidizing the TEMAZ saturated ZrO{sub 2}. • We discuss the reaction mechanism of the RT-ZrO{sub 2} ALD. - Abstract: Room-temperature atomic layer deposition (ALD) of ZrO{sub 2} is developed with tetrakis(ethylmethylamino)zirconium (TEMAZ) and a plasma-excited humidified argon. A growth per cycle of 0.17 nm/cycle at room temperature is confirmed, and the TEMAZ adsorption and its oxidization on ZrO{sub 2} are characterized by IR absorption spectroscopy with a multiple internal reflection mode. TEMAZ is saturated on a ZrO{sub 2} surface with exposures exceeding ∼2.0 × 10{sup 5} Langmuir (1 Langmuir = 1.0 × 10{sup −6} Torr s) at room temperature, and the plasma-excited humidified argon is effective in oxidizing the TEMAZ-adsorbed ZrO{sub 2} surface. The IR absorption spectroscopy suggests that Zr-OH works as an adsorption site for TEMAZ. The reaction mechanism of room-temperature ZrO{sub 2} ALD is discussed in this paper.

  17. Optical emission spectroscopy for quantification of ultraviolet radiations and biocide active species in microwave argon plasma jet at atmospheric pressure

    Energy Technology Data Exchange (ETDEWEB)

    Wattieaux, G., E-mail: gaetan.wattieaux@laplace.univ-tlse.fr; Yousfi, M.; Merbahi, N.

    2013-11-01

    This work deals with absorption and mainly emission spectrometry of a microwave induced surfatron plasma jet launched in ambient air and using an Argon flow carrier gas. The Ar flow rate varies between 1 and 3 L/min and the microwave power between 40 and 60 W. The analysis of the various spectra has led to the determination of the ozone and atomic oxygen concentrations, ultraviolet (UV) irradiance separating UVA, UVB and UVC, gas temperature, plasma electron density and excitation temperature. Most of these diagnostics are spatially resolved along the plasma jet axis. It is shown more particularly that rotational temperature obtained from OH(A-X) spectra ranges between 800 K to 1000 K while the apparent temperature of the plasma jet remains lower than about 325 K which is compatible with biocide treatment without significant thermal effect. The electron density reaches 1.2 × 10{sup 14} cm{sup −3}, the excitation temperature is about 4000 K, the UVC radiation represents only 5% of the UV radiations emitted by the device, the ozone concentration is found to reach 88 ± 27 ppm in the downstream part of the plasma jet at a distance of 30 mm away from the quartz tube outlet of the surfatron and the atomic oxygen concentration lies between 10 and 80 ppm up to a distance of 20 mm away from the quartz tube outlet. Ozone is identified as the main germicidal active species produced by the device since its concentration is in accordance with bacteria inactivation durations usually reported using such plasma devices. Human health hazard assessment is carried out all along this study since simple solutions are reminded to respect safety standards for exposures to ozone and microwave leakage. In this study, an air extraction unit is used and a Faraday cage is set around the quartz tube of the surfatron and the plasma jet. These solutions should be adopted by users of microwave induced plasma in open air conditions because according to the literature, this is not often the

  18. Optical emission spectroscopy for quantification of ultraviolet radiations and biocide active species in microwave argon plasma jet at atmospheric pressure

    International Nuclear Information System (INIS)

    Wattieaux, G.; Yousfi, M.; Merbahi, N.

    2013-01-01

    This work deals with absorption and mainly emission spectrometry of a microwave induced surfatron plasma jet launched in ambient air and using an Argon flow carrier gas. The Ar flow rate varies between 1 and 3 L/min and the microwave power between 40 and 60 W. The analysis of the various spectra has led to the determination of the ozone and atomic oxygen concentrations, ultraviolet (UV) irradiance separating UVA, UVB and UVC, gas temperature, plasma electron density and excitation temperature. Most of these diagnostics are spatially resolved along the plasma jet axis. It is shown more particularly that rotational temperature obtained from OH(A-X) spectra ranges between 800 K to 1000 K while the apparent temperature of the plasma jet remains lower than about 325 K which is compatible with biocide treatment without significant thermal effect. The electron density reaches 1.2 × 10 14 cm −3 , the excitation temperature is about 4000 K, the UVC radiation represents only 5% of the UV radiations emitted by the device, the ozone concentration is found to reach 88 ± 27 ppm in the downstream part of the plasma jet at a distance of 30 mm away from the quartz tube outlet of the surfatron and the atomic oxygen concentration lies between 10 and 80 ppm up to a distance of 20 mm away from the quartz tube outlet. Ozone is identified as the main germicidal active species produced by the device since its concentration is in accordance with bacteria inactivation durations usually reported using such plasma devices. Human health hazard assessment is carried out all along this study since simple solutions are reminded to respect safety standards for exposures to ozone and microwave leakage. In this study, an air extraction unit is used and a Faraday cage is set around the quartz tube of the surfatron and the plasma jet. These solutions should be adopted by users of microwave induced plasma in open air conditions because according to the literature, this is not often the case

  19. Changes of plasma IL-6 and TNF-α levels during peri-operative period in patients undergoing laser photo-coagulation of greater saphenous varicosities

    International Nuclear Information System (INIS)

    Wang Taihan; Wang Chunxi

    2005-01-01

    Objective: To investigate the plasma levels of IL-6 and TNF-α during peri-operative period in patients undergoing laser photocoagulation of greater saphenous varicosities. Methods: Plasma IL-6 and TNF-α levels were determined with RIA before operation and 1, 3, 7, 14 days post-operatively in 110 patients with greater saphenous vein varicosity undergoing different forms of treatment (intravascular laser photo-coagulation 43, photo-coagulation combined with venous valve repair 35, high ligation and segmental stripping 32). Skin trophic disturbances were present in 56 of the 110 patients. Plasma IL-6 and TNF-α levels were also measured in 33 controls. Results: The plasma IL-6 and TNF-α levels in patients with skin trophic disturbances were significantly higher than those in controls (P<0.01), while levels in patients without skin lesions were not much changed. The plasma IL-6 and TNF-α levels were increased at first and dropped later to approaching pre-operative value by d14 in all the 110 patients after operation, however, the amount of increase was least and the normalization was also soonest in the simple photo-coagulation group, the reverse was true for the conventional operation group. Conclusion: Laser photo-coagulation is least stressful among the three types of operation and magnitude of changes of plasma IL-6 and TNF-α levels correctly reflects the intensity of stress. (authors)

  20. Investigation on the energy spectrums of electrons in atmospheric pressure argon plasma jets and their dependences on the applied voltage

    Science.gov (United States)

    Chen, Xinxian; Tan, Zhenyu; Liu, Yadi; Li, Xiaotong; Pan, Jie; Wang, Xiaolong

    2017-08-01

    This work presents a systematical investigation on the spatiotemporal evolution of the energy spectrum of electrons in atmospheric pressure argon plasma jets and its dependence on the applied voltage. The investigations are carried out by means of the numerical simulation based on a particle-in-cell Monte-Carlo collision model. The characteristics of the spatiotemporal evolution of the energy spectrum of electrons (ESE) in the discharge space have been presented, and especially the mechanisms of inducing these characteristics have also been revealed. The present work shows the following conclusions. In the evolution of ESE, there is a characteristic time under each applied voltage. Before the characteristic time, the peak value of ESE decreases, the peak position shifts toward high energy, and the distribution of ESE becomes wider and wider, but the reverse is true after the characteristic time. The formation of these characteristics can be mainly attributed to the transport of electrons toward a low electric field as well as a balance between the energy gained from the electric field including the effect of space charges and the energy loss due to inelastic collisions in the process of electron transport. The characteristic time decreases with the applied voltage. In addition, the average energy of electrons at the characteristic time can be increased by enhancing the applied voltage. The results presented in this work are of importance for regulating and controlling the energy of electrons in the plasma jets applied to plasma medicine.

  1. The application of cold-plasma coagulation on the visceral pleura results in a predictable depth of necrosis without fistula generation

    OpenAIRE

    Hoffmann, Martin; Ulrich, Anita; Schloericke, Erik; Limmer, Stefan; Habermann, Jens Karsten; Wolken, Heike; Bruch, Hans-Peter; Kujath, Peter

    2011-01-01

    A technique for the safe transfer of electric energy to the pulmonary surface for the potential evaporation of malignant tumours is non-existent to date. By conducting the current study, we wanted to generate data on the potential beneficiary effects and complications of using cold-plasma coagulation on the pulmonary surface. Cold-plasma coagulation was applied to the pulmonary surface in eight female mini-pigs via a thoracoscopic access. After 12 days, we performed a re-thoracoscopy on the c...

  2. Spectral blueshifts in laser light scattered from argon-gas-cluster plasmas

    International Nuclear Information System (INIS)

    Singhal, H.; Arora, V.; Naik, P.A.; Gupta, P.D.

    2005-01-01

    An experimental study is presented on scattering of laser light from argon gas clusters irradiated by multipicosecond Nd:glass laser pulses at moderate intensity of 10 15 W/cm 2 . Space-resolved side-scattered laser light has a predominantly blueshifted and broadened spectrum (up to ∼8 nm). The scattered signal intensity and average blueshift exhibit a marked dependence on the backing pressure of the gas. The results are explained by self-phase modulation of the laser radiation due to changing polarizability as the heated clusters pass through resonance at 3 times the critical density during which intense absorption and scattering occurs. The observed blueshift may be useful in diagnostics of this important phase of laser-cluster interactions

  3. Powder Particle Penetration into Steam-argon Plasma Jet and its Relation with Particle Parameters

    Czech Academy of Sciences Publication Activity Database

    Chumak, Oleksiy; Kopecký, Vladimír; Konrád, Miloš; Hrabovský, Milan; Kavka, Tetyana

    2004-01-01

    Roč. 54, suppl. C (2004), C931-C936 ISSN 0011-4626. [Symposium on Plasma Physics and Technology /21st/. Praha, 14.06.2004-17.06.2004] R&D Projects: GA AV ČR KSK2043105 Institutional research plan: CEZ:AV0Z2043910 Keywords : plasma sprazing, torch with hybrid stabilization, particle temperature Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 0.292, year: 2004

  4. Plasma diagnostics of the SIMPA Ecr ion source by X-ray spectroscopy, Collisions of H-like Neon ions with Argon clusters

    International Nuclear Information System (INIS)

    Adrouche, N.

    2006-09-01

    The first part of this thesis is devoted to the SIMPA ECR ion source characterization, first, I explored the ion source's capacities on the point of view of extracted currents for three elements, argon, krypton and neon. By analyzing the Bremsstrahlung spectra, I determined the electronic temperature in the plasma and the electronic and ionic densities. In a second time, I recorded high resolution X-spectra of argon and krypton plasma's. By taking into account the principal mechanisms of production of a K hole in the ions inside the plasma, I determined the ionic densities of the high charge states of argon. Lastly, I highlighted a correlation between the ions charge states densities with the intensities of extracted currents. The second part of the thesis is devoted to Ne 9+- argon clusters collisions. First, I presented simple and effective theoretical models allowing to describe the phenomena occurring during a collision, from the point of view of the projectile. I carried out a simulation for a collision of an ion Ne 9+ with an argon cluster of a given size, which has enabled us to know the energy levels populated during the electronic capture and to follow the number of electrons in each projectile shell. Lastly, I presented the first results of a collision between a Ne 9+ beam and argon clusters. These results, have enabled me by using projectile X-ray spectroscopy during the ions-clusters collision, to evidence a strong clustering of targets atoms and to highlight an electronic multi-capture in the projectile ion excited states. (author)

  5. Thomson scattering on argon surfatron plasmas at intermediate pressures: Axial profiles of the electron temperature and electron density

    Energy Technology Data Exchange (ETDEWEB)

    Palomares, J.M., E-mail: f02palij@gmail.co [Departamento de Fisica, Universidad de Cordoba, Campus de Rabanales, ed. C-2, 14071 Cordoba (Spain); Iordanova, E.; Veldhuizen, E.M. van; Baede, L. [Department of Applied Physics, Eindhoven University of Technology, PO Box 513, 5600 MB Eindhoven (Netherlands); Gamero, A.; Sola, A. [Departamento de Fisica, Universidad de Cordoba, Campus de Rabanales, ed. C-2, 14071 Cordoba (Spain); Mullen, J.J.A.M. van der, E-mail: j.j.a.m.v.d.Mullen@tue.n [Department of Applied Physics, Eindhoven University of Technology, PO Box 513, 5600 MB Eindhoven (Netherlands); Departamento de Fisica, Universidad de Cordoba, Campus de Rabanales, ed. C-2, 14071 Cordoba (Spain)

    2010-03-15

    The axial profiles of the electron density n{sub e} and electron temperature T{sub e} of argon surfatron plasmas in the pressure range of 6-20 mbar and microwave power between 32 and 82 W have been determined using Thomson Scattering of laser irradiation at 532 nm. For the electron density and temperature we found values in the ranges 5 x 10{sup 18} < n{sub e} < 8 x 10{sup 19} m{sup -3} and 1.1 < T{sub e} < 2.0 eV. Due to several improvements of the setup we could reduce the errors of n{sub e} and T{sub e} down to 8% and 3%, respectively. It is found that n{sub e} decreases in the direction of the wave propagation with a slope that is nearly constant. The slope depends on the pressure but not on the power. Just as predicted by theories we see that increasing the power leads to longer plasma columns. However, the plasmas are shorter than what is predicted by theories based on the assumption that for the plasma-wave interaction electron-atom collisions are of minor importance (the so-called collisionless regime). The plasma vanishes long before the critical value of the electron density is reached. In contrast to what is predicted by the positive column model it is found that T{sub e} does not stay constant along the column, but monotonically increases with the distance from the microwave launcher. Increases of more than 50% over 30 cm were found.

  6. Measurement of plasma-surface energy fluxes in an argon rf-discharge by means of calorimetric probes and fluorescent microparticles

    International Nuclear Information System (INIS)

    Maurer, H. R.; Kersten, H.; Hannemann, M.; Basner, R.

    2010-01-01

    Measured energy influx densities toward a tungsten dummy substrate in an argon rf-plasma are presented and a model for the description of the energy influx density based on plasma parameters, which have been obtained by Langmuir probe measurements, is applied. Furthermore, temperature measurements of microparticles are presented, which are confined in the plasma sheath. An extension of the model is developed for the description of the energy influx density to the particles. The comparison of model and experimental results offer the possibility to obtain an improved understanding of plasma-surface interactions.

  7. Emission Spectroscopy of OH Radical in Water-Argon Arc Plasma Jet

    Czech Academy of Sciences Publication Activity Database

    Mašláni, Alan; Sember, Viktor

    2014-01-01

    Roč. 2014, April (2014), "952138"-"952138" ISSN 2314-4920 R&D Projects: GA ČR GAP205/11/2070 Institutional support: RVO:61389021 Keywords : Emission spectroscopy * OH radical * arc plasma jet Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 0.538, year: 2014 http://www.hindawi.com/journals/jspec/2014/952138/abs/

  8. Production of high quality syngas from argon/water plasma gasification of biomass and waste

    Czech Academy of Sciences Publication Activity Database

    Hlína, Michal; Hrabovský, Milan; Kavka, Tetyana; Konrád, Miloš

    2014-01-01

    Roč. 34, č. 1 (2014), s. 63-66 ISSN 0956-053X R&D Projects: GA ČR GAP205/11/2070; GA MŠk MEB020814 Institutional support: RVO:61389021 Keywords : Biomass * Gasification * Plasma * Tar Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 3.220, year: 2014

  9. Characterizing dusty argon-acetylene plasmas as a first step to understand dusty EUV environments

    NARCIS (Netherlands)

    Wetering, van de F.M.J.H.; Nijdam, S.; Kroesen, G.M.W.

    2012-01-01

    In extreme ultraviolet (EUV) lithography, ionic and particulate debris coming from the plasma source plays an important role. We started up a project looking at the principles of particle formation in plasmas and the interaction with EUV radiation. To this end, we study a low-pressure (10 Pa)

  10. Diagnostics of Plasma Jet Generated in Water/Argon DC Arc Torch.

    Czech Academy of Sciences Publication Activity Database

    Hurba, Oleksiy; Hlína, Michal; Hrabovský, Milan

    2016-01-01

    Roč. 3, č. 1 (2016), s. 5-8 ISSN 2336-2626. [Symposium on Physics of Switching Arc 2015, FSO 2015 /21./. Nové Město na Moravě, 07.09.2015-11.09.2015] R&D Projects: GA ČR(CZ) GA15-19444S Institutional support: RVO:61389021 Keywords : thermal plasma jet * electric probes * schlieren photography * enthalpy probe Subject RIV: BL - Plasma and Gas Discharge Physics OBOR OECD: Fluids and plasma physics (including surface physics)

  11. Effect of argon and hydrogen on deposition of silicon from tetrochlrosilane in cold plasmas

    Science.gov (United States)

    Manory, R. R.; d.

    1985-01-01

    The roles of Ar and H2 on the decomposition of SiCl4 in cold plasma were investigated by Langmuir probes and mass spectrometry. Decomposition of the reactant by Ar only has been found to be very slow. In presence of H2 in the plasma SiCl4 is decomposed by fast radical-molecule reactions which are further enhanced by Ar due to additional ion-molecule reactions in which more H radicals are produced. A model for the plasma-surface interactions during deposition of mu-Si in the Ar + H2 + SiCl4 system is presented.

  12. Plasma parameters and electromagnetic forces induced by the magneto hydro dynamic interaction in a hypersonic argon flow experiment

    International Nuclear Information System (INIS)

    Cristofolini, Andrea; Neretti, Gabriele; Borghi, Carlo A.

    2012-01-01

    This work proposes an experimental analysis on the magneto hydro dynamic (MHD) interaction induced by a magnetic test body immersed into a hypersonic argon flow. The characteristic plasma parameters are measured. They are related to the voltages arising in the Hall direction and to the variation of the fluid dynamic properties induced by the interaction. The tests have been performed in a hypersonic wind tunnel at Mach 6 and Mach 15. The plasma parameters are measured in the stagnation region in front of the nozzle of the wind tunnel and in the free stream region at the nozzle exit. The test body has a conical shape with the cone axis in the gas flow direction and the cone vertex against the flow. It is placed at the nozzle exit and is equipped with three permanent magnets. In the configuration adopted, the Faraday current flows in a closed loop completely immersed into the plasma of the shock layer. The electric field and the pressure variation due to MHD interaction have been measured on the test body walls. Microwave adsorption measurements have been used for the determination of the electron number density and the electron collision frequency. Continuum recombination radiation and line radiation emissions have been detected. The electron temperature has been determined by means of the spectroscopic data by using different methods. The electron number density has been also determined by means of the Stark broadening of H α and the H β lines. Optical imaging has been utilized to visualize the pattern of the electric current distribution in the shock layer around the test body. The experiments show a considerable effect of the electromagnetic forces produced by the MHD interaction acting on the plasma flow around the test body. A comparison of the experimental data with simulation results shows a good agreement.

  13. Experimental study of the hollow cathode radio-frequency plasma mixture: Argon-Oxygen

    International Nuclear Information System (INIS)

    Saloum, S.; Naddaf, M.

    2008-01-01

    This study presents experimental results of plasma gas mixture Ar-O 2 for different mixing ratios in radio-frequency hollow cathode plasma. The following plasma parameters have been investigated: The electronic temperature, plasma potential, floating potential, emission atomic lines intensities, as a function of some variables, where the effect of power has been studied in the range [100-300 W], and the effect of pressure has been studied in the range [0.05-0.3 mbar]. The effect of relative composition has been studied for a fixed power and pressure. Two diagnostic techniques have been employed: Optical emission spectroscopy and langmuir probe. The most important result of this study is the ability to measure the relative atomic density of oxygen by optical emission spectroscopy, where the maximum of this density is obtained for the mixture 40% Ar - 60% O 2 . (author)

  14. DIAGNOSTICS OF HYBRID WATER/ARGON THERMAL PLASMA JET WITH WATER, ETHANOL AND THEIR MIXTURE INJECTION TO PLASMA

    Czech Academy of Sciences Publication Activity Database

    Hlína, Michal; Mašláni, Alan; Medřický, Jan; Kotlan, Jiří; Mušálek, Radek; Hrabovský, Milan

    2016-01-01

    Roč. 3, č. 2 (2016), s. 62-65 ISSN 2336-2626. [SPPT 2016 - 27th Symposium on Plasma Physics and Technology/27./. Prague, 20.06.2016-23.06.2016] R&D Projects: GA ČR GA15-12145S Institutional support: RVO:61389021 Keywords : plasma spraying * suspension * enthalpy probe * spectroscopy * air entrainment Subject RIV: BL - Plasma and Gas Discharge Physics http://ppt.fel.cvut.cz/

  15. Atmospheric non-thermal argon-oxygen plasma for sunflower seedling growth improvement

    Science.gov (United States)

    Matra, Khanit

    2018-01-01

    Seedling growth enhancement of sunflower seeds by DC atmospheric non-thermal Ar-O2 plasma has been proposed. The plasma reactor was simply designed by the composition of multi-pin electrodes bonded on a solderable printed circuit board (PCB) anode. A stable plasma was exhibited in the non-periodical self-pulsing discharge mode during the seed treatment. The experimental results showed that non-thermal plasma treatment had a significant positive effect on the sunflower seeds. Ar-O2 mixed gas ratio, treatment time and power source voltage are the important parameters affecting growth stimulation of sunflower sprouts. In this research, the sunflower seeds treated with 3:3 liters per minute (LPM) of Ar-O2 plasma at a source voltage of 8 kV for 1 min showed the best results in stimulating the seedling growth. The results in this case showed that the dry weight and average shoot length of the sunflower sprouts were 1.79 and 2.69 times higher and heavier than those of the untreated seeds, respectively.

  16. The application of cold-plasma coagulation on the visceral pleura results in a predictable depth of necrosis without fistula generation

    Science.gov (United States)

    Hoffmann, Martin; Ulrich, Anita; Schloericke, Erik; Limmer, Stefan; Habermann, Jens Karsten; Wolken, Heike; Bruch, Hans-Peter; Kujath, Peter

    2012-01-01

    A technique for the safe transfer of electric energy to the pulmonary surface for the potential evaporation of malignant tumours is non-existent to date. By conducting the current study, we wanted to generate data on the potential beneficiary effects and complications of using cold-plasma coagulation on the pulmonary surface. Cold-plasma coagulation was applied to the pulmonary surface in eight female mini-pigs via a thoracoscopic access. After 12 days, we performed a re-thoracoscopy on the contralateral side. After a further 12 days, we performed a median sternotomy and did cold-plasma coagulation on previously untreated areas of either lung. No pulmonary fistulas were detected. In two of the eight pigs, we found a localized chronic pneumonia. None of the pigs died during the course of the study. Morbidity was also low with two pigs refusing food intake, one pig with dyspnoea after difficult intubation and one pig coughing. All events were self-limited and occurred only on post-operative Day 1. The treatment effect was almost linear and correlated to the generator energy applied. The differences between the effects reached statistical significance (P < 0.05). The application of cold-plasma coagulation to the pulmonary surface is safe in pigs. A potential clinical application of this technique is treatment of malignant pleural mesothelioma. PMID:22194274

  17. The Role of Spraying Parameters and Inert Gas Shrouding in Hybrid Water-Argon Plasma Spraying of Tungsten and Copper for Nuclear Fusion Applications

    Czech Academy of Sciences Publication Activity Database

    Matějíček, Jiří; Kavka, Tetyana; Bertolissi, Gabriele; Ctibor, Pavel; Vilémová, Monika; Mušálek, Radek; Nevrlá, Barbara

    2013-01-01

    Roč. 22, č. 5 (2013), s. 744-755 ISSN 1059-9630 R&D Projects: GA MPO FR-TI2/702; GA TA ČR TA01010300 Institutional support: RVO:61389021 Keywords : plasma spraying * tungsten * copper * inert gas shrouding * water-argon plasma torch * gas shroud * hybrid plasma torch * influence of spray parameters * nuclear fusion * oxidation Subject RIV: JG - Metallurgy Impact factor: 1.491, year: 2013 http://link.springer.com/content/pdf/10.1007%2Fs11666-013-9895-x.pdf

  18. The study of selective emission lines from plasma, obtained by evaporating as sample by laser radiation in air and argon media

    International Nuclear Information System (INIS)

    Sufian, A.; Dimitrov, G.

    1993-01-01

    Ultra violet visible emission spectroscopic analysis of a plasma produced through laser interaction with a solid probe in different gaseous atmospheres is conducted. Reported are the effects of air and argon, as enveloping media, on the spectral intensities of some lines. The temperature gradient of the plasma, in different atmosphere, is also plotted. In order to improve the detection limits of individual elements, suggested are the possible areas of illuminating the slit of the spectroscopic from the plasma, in respect of the height, above the sample, when working in different gaseous media. (author)

  19. An investigation into the role of metastable states on excited populations of weakly ionized argon plasmas, with applications for optical diagnostics

    Science.gov (United States)

    Arnold, Nicholas; Loch, Stuart; Ballance, Connor; Thomas, Ed

    2017-10-01

    Low temperature plasmas (Te ADAS) code suite to calculate a level-resolved, generalized collisional-radiative (GCR) model for line emission in low temperature argon plasmas. By combining our theoretical model with experimental electron temperature, density, and spectral measurements from the Auburn Linear eXperiment for Instability Studies (ALEXIS), we have developed diagnostic techniques to measure metastable fraction, electron temperature, and electron density. In the future we hope to refine our methods, and extend our model to plasmas other than ALEXIS. Supported by the U.S. Department of Energy. Grant Number: DE-FG02-00ER54476.

  20. REMC Computer Simulation of the Thermodynamic Properties of Argon and Air Plasmas

    Czech Academy of Sciences Publication Activity Database

    Lísal, Martin; Smith, W. R.; Bureš, M.; Vacek, V.; Navrátil, J.

    2002-01-01

    Roč. 100, č. 15 (2002), s. 2487-2497 ISSN 0026-8976 R&D Projects: GA ČR GA203/98/1446; GA ČR GA203/02/0805 Grant - others:NSERC(CA) OGP1041 Keywords : computer simulation * plasma * thermodynamic properties Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 1.617, year: 2002

  1. Scalable graphene production from ethanol decomposition by microwave argon plasma torch

    Science.gov (United States)

    Melero, C.; Rincón, R.; Muñoz, J.; Zhang, G.; Sun, S.; Perez, A.; Royuela, O.; González-Gago, C.; Calzada, M. D.

    2018-01-01

    A fast, efficient and simple method is presented for the production of high quality graphene on a large scale by using an atmospheric pressure plasma-based technique. This technique allows to obtain high quality graphene in powder in just one step, without the use of neither metal catalysts and nor specific substrate during the process. Moreover, the cost for graphene production is significantly reduced since the ethanol used as carbon source can be obtained from the fermentation of agricultural industries. The process provides an additional benefit contributing to the revalorization of waste in the production of a high-value added product like graphene. Thus, this work demonstrates the features of plasma technology as a low cost, efficient, clean and environmentally friendly route for production of high-quality graphene.

  2. Effect of CO on NO and N2O conversions in nonthermal argon plasma

    International Nuclear Information System (INIS)

    Zhao Guibing; Argyle, Morris D.; Radosz, Maciej

    2006-01-01

    200-600 ppm of CO inhibit NO conversion in nonthermal Ar plasma, but do not produce N 2 O. However, 1.01% of CO has no effect on NO conversion, but produces N 2 O. In general, N 2 O conversion in Ar plasma decreases with increasing CO concentration. These experimental results cannot be explained by charge transfer reactions of Ar + . Selectivity analysis of all excited states of Ar possibly contributing to NO x conversion without and with CO suggests that only Ar( 3 P 2 ) contributes to NO x conversion and CO dissociation. A kinetic model of 43 reactions is required to model NO conversion or N 2 O conversion in Ar without CO, whereas 81 reactions are required to model NO conversion and N 2 O conversion in Ar with CO. At constant gas pressure, a single set of model parameters can predict NO conversion or N 2 O conversion without and with CO. All experimental results can be explained using a reaction mechanism in which excited neutral states of Ar are the only active species, which supports the conclusion that cations have a negligible impact on these nonthermal plasma reactions

  3. Etching of Niobium in an Argon-Chlorine Capacitively Coupled Plasma

    Science.gov (United States)

    Radovanov, Svetlana; Samolov, Ana; Upadhyay, Janardan; Peshl, Jeremy; Popovic, Svetozar; Vuskovic, Leposava; Applied Materials, Varian Semiconductor Team; Old Dominion University Team

    2016-09-01

    Ion assisted etching of the inner surfaces of Nb superconducting radio frequency (SRF) cavities requires control of incident ion energies and fluxes to achieve the desired etch rate and smooth surfaces. In this paper, we combine numerical simulation and experiment to investigate Ar /Cl2 capacitively coupled plasma (CCP) in cylindrical reactor geometry. Plasma simulations were done in the CRTRS 2D/3D code that self-consistently solves for CCP power deposition and electrostatic potential. The experimental results are used in combination with simulation predictions to understand the dependence of plasma parameters on the operating conditions. Using the model we were able to determine the ion current and flux at the Nb substrate. Our simulations indicate the relative importance of the current voltage phase shift and displacement current at different pressures and powers. For simulation and the experiment we have used a test structure with a pillbox cavity filled with niobium ring-type samples. The etch rate of these samples was measured. The probe measurements were combined with optical emission spectroscopy in pure Ar for validation of the model. The authors acknowledge Dr Shahid Rauf for developing the CRTRS code. Support DE-SC0014397.

  4. Stationary Population Inversion in an Expanding Argon Plasma Jet by Helium Puffing

    International Nuclear Information System (INIS)

    Akatsuka, H.; Kano, K.

    2005-01-01

    An experiment of He gas-contact for generating population inversion in a recombining Ar plasma jet is carried out. Population inversion between Ar I excited states 5s' → 4p'[1/2]1 and 5s' → 4p[3/2]1,2, [5/2]2,3 is created by helium gas-contact cooling of electrons, whereas it is not created without gas-contact. Ar I lines 1.14 μm, 1.34 μm, and 1.09 μm are strongly enhanced due to the He gas cooling. It is experimentally found that helium gas contact effectively lowers electron temperature of the Ar plasma jet. The mechanisms giving rise to population inversion are discussed in terms of atomic collisional processes of the recombining plasma. The experimental results of electron temperature and population densities are discussed by simple numerical analysis which we previously developed. It is shown that the experimental results are well explained by our modeling quantitatively for the case without gas contact, except that the agreement of number densities of lower lying non-LTE levels is qualitative for the case with the gas contact

  5. Optical characteristics and parameters of gas-discharge plasma in a mixture of mercury dibromide vapor with argon

    Science.gov (United States)

    Malinina, A. A.; Malinin, A. N.

    2015-03-01

    Results are presented from studies of the optical characteristics and parameters of the plasma of a dielectric barrier discharge in a mixture of mercury dibromide vapor with argon—the working medium of an exciplex gas-discharge emitter. It is established that the partial pressures of mercury dibromide vapor and argon at which the average and pulsed emission intensities in the blue—green spectral region (λmax = 502 nm) reach their maximum values are 0.6 and 114.4 kPa, respectively. The electron energy distribution function, the transport characteristics, the specific power spent on the processes involving electrons, the electron density and temperature, and the rate constants for the processes of elastic and inelastic electron scattering from the molecules and atoms of the working mixture are determined by numerical simulation, and their dependences on the reduced electric field strength are analyzed. The rate constant of the process leading to the formation of exciplex mercury monobromide molecules for a reduced electric field of E/ N = 20 Td, at which the maximum emission intensity in the blue—green spectral region was observed in this experiment, is found to be 8.1 × 10-15 m3/s.

  6. Optical characteristics and parameters of gas-discharge plasma in a mixture of mercury dibromide vapor with argon

    Energy Technology Data Exchange (ETDEWEB)

    Malinina, A. A., E-mail: alexandr-malinin@rambler.ru; Malinin, A. N. [Uzhhorod National University (Ukraine)

    2015-03-15

    Results are presented from studies of the optical characteristics and parameters of the plasma of a dielectric barrier discharge in a mixture of mercury dibromide vapor with argon—the working medium of an exciplex gas-discharge emitter. It is established that the partial pressures of mercury dibromide vapor and argon at which the average and pulsed emission intensities in the blue—green spectral region (λ{sub max} = 502 nm) reach their maximum values are 0.6 and 114.4 kPa, respectively. The electron energy distribution function, the transport characteristics, the specific power spent on the processes involving electrons, the electron density and temperature, and the rate constants for the processes of elastic and inelastic electron scattering from the molecules and atoms of the working mixture are determined by numerical simulation, and their dependences on the reduced electric field strength are analyzed. The rate constant of the process leading to the formation of exciplex mercury monobromide molecules for a reduced electric field of E/N = 20 Td, at which the maximum emission intensity in the blue—green spectral region was observed in this experiment, is found to be 8.1 × 10{sup −15} m{sup 3}/s.

  7. Optical characteristics and parameters of gas-discharge plasma in a mixture of mercury dibromide vapor with argon

    International Nuclear Information System (INIS)

    Malinina, A. A.; Malinin, A. N.

    2015-01-01

    Results are presented from studies of the optical characteristics and parameters of the plasma of a dielectric barrier discharge in a mixture of mercury dibromide vapor with argon—the working medium of an exciplex gas-discharge emitter. It is established that the partial pressures of mercury dibromide vapor and argon at which the average and pulsed emission intensities in the blue—green spectral region (λ max = 502 nm) reach their maximum values are 0.6 and 114.4 kPa, respectively. The electron energy distribution function, the transport characteristics, the specific power spent on the processes involving electrons, the electron density and temperature, and the rate constants for the processes of elastic and inelastic electron scattering from the molecules and atoms of the working mixture are determined by numerical simulation, and their dependences on the reduced electric field strength are analyzed. The rate constant of the process leading to the formation of exciplex mercury monobromide molecules for a reduced electric field of E/N = 20 Td, at which the maximum emission intensity in the blue—green spectral region was observed in this experiment, is found to be 8.1 × 10 −15 m 3 /s

  8. Density of atoms in Ar*(3p5 4s) states and gas temperatures in an argon surfatron plasma measured by tunable laser spectroscopy

    NARCIS (Netherlands)

    Hübner, S.; Sadeghi, N.; Carbone, E.A.D.; Mullen, van der J.J.A.M.

    2013-01-01

    This study presents the absolute argon 1 s (in Paschens’s notation) densities and the gas temperature, Tg, obtained in a surfatron plasma in the pressure range 0:65

  9. Plasma polymer films rf sputtered from PTFE under various argon pressures

    Czech Academy of Sciences Publication Activity Database

    Stelmashuk, Vitaliy; Biederman, H.; Slavinská, D.; Zemek, Josef; Trchová, Miroslava

    2005-01-01

    Roč. 77, č. 2 (2005), s. 131-137 ISSN 0042-207X R&D Projects: GA MŠk(CZ) OC 527.10; GA MŠk(CZ) OC 527.90 Grant - others:EUREKAΣ2080(XE) OE57 Institutional research plan: CEZ:AV0Z10100521; CEZ:AV0Z20430508 Keywords : RF sputtering * PTFE * fluorcarbon plasma polymers * thin film * teflon * deposition Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 0.909, year: 2005

  10. Study on the characteristics of hysteresis loop and resistance of glow discharge plasma using argon gas

    Science.gov (United States)

    Mathew, Prijil; Sajith Mathews, T.; Kurian, P. J.; Chattopadyay, P. K.

    2018-05-01

    Hysteresis in discharge current is produced in a low-pressure, magnetic field free, Glow discharge plasma by varying discharge voltage. The variation in area of the hysteresis loops with pressure, electrode distance and load resistor studied. To understand, the nonlinear behaviour of the I-V characteristics, the changes in gas resistance with electrode voltage, pressure and load resistor were studied. After many trials we propose the best suitable empirical equation for the exponential decrease of the gas resistance with electrode voltage as; R = Rmin + Ae-0.008V, which is a novel one and matches well with our experimental results.

  11. Influence of non-equilibrium effects on plasma property functions in hybrid water-argon plasma torch

    Czech Academy of Sciences Publication Activity Database

    Křenek, Petr; Hrabovský, Milan

    2010-01-01

    Roč. 14, 1-2 (2010), s. 95-100 ISSN 1093-3611. [European High Temperature Plasma Processes (HTPP)/10th./. Patras (Patras University), 07.07.2008-11.07.2008] R&D Projects: GA ČR GA202/08/1084 Institutional research plan: CEZ:AV0Z20430508 Keywords : Thermal plasma * material properties * non-equlibrium phenomena * dc arc torch Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 0.189, year: 2010 http://www.begellhouse.com/journals/57d172397126f956,227c67f42b79464a,5bbc4c7760b4b6cb.html

  12. Argon plasma treated electrospun P(Hola-E-Cl) Clay nanofiber composite: Effect on its antibacterial activity against S. Aureus and E.Coli

    International Nuclear Information System (INIS)

    Monserate, Juvy J.; Sumera, Florentino C.; Ramos, Henry J.; Daseco, Joanna Abigael

    2015-01-01

    In this work, the effects of argon plasma surface modification have been studied on electrospun P(HOLA-e-CL) Clay Nanofiber Composites in order to investigate the imposed limitation and possibilities to improve surface characteristics on fibrous assemblies. These assemblies were characterized using Scanning Electron Microscopy to determine the surface morphology and diameter size of the fiber. Fourier Transform Infrared Spectroscopy (FTIR) was employed to find out the positions of peaks similar to the constituent components incorporated during the process of polymerization which implied that the IR spectra illustrated the evidence of an interaction between clay and the polymer matrix. XRD peaks on increasing d-spacing going to the left 2?<20 0 verifies the results of interaction between the polymer and the ALA-MMT nanoclay. Thus this also suggested that the polymer was intercalated into the ALA-MMT. The Argon Plasma electrospun nanofiber was subjected to its antibacterial property against S. aureaus (gram positive) and E. coli (gram negative) bacteria. DMRT statistically revealed significantly at 5% level of significance shows that all treatments at increasing clay loading inhibit the growth of S. Aureus and E. Coli. Thus, Argon Plasma treated electrospun P(HOLA-e-CL) Clay Nanofiber Composites can be an excellent scaffold material for wound dressing applications. (author)

  13. Mass spectra and ionization temperatures in an argon-nitrogen inductively coupled plasma

    International Nuclear Information System (INIS)

    Houk, R.S.; Montaser, A.; Fassel, V.A.

    1983-01-01

    Positive ions were extracted from the axial channel of an inductively coupled plasma (ICP) in which the outer gas flow was Ar, N 2 , or a mixture of Ar and N 2 . Addition of N 2 to the outer gas decreases the electron number density (n/sub e/) in the axial channel. Ar +2 , O 2 + , and ArH + react with N-containing species in the plasma and/or during the ion extraction process. Ar + remains abundant even if there is no Ar in the outer gas, which indicates the probable occurrence of charge transfer reactions between N 2 + and Ar. The present work corroborates two general concepts upon which several theories of theorigin of suprathermal ionization in ICPs are based: (a) species are physically transported from the induction region to the axial channel; and (b) these species may react with a ionize neutral species in the axial channel. Ionization temperatures (T/sub ion/) measured from the ratio Cd + /I + were 5750 to 6700 K for a N 2 outer flow ICP a forward power of 1.2 kW. This T/sub ion/ range is significantly below that obtained for an Ar outer gas ICP under otherwise similar operating parameters

  14. Neutralisation of the anti-coagulant effects of heparin by histones in blood plasma and purified systems.

    Science.gov (United States)

    Longstaff, Colin; Hogwood, John; Gray, Elaine; Komorowicz, Erzsebet; Varjú, Imre; Varga, Zoltán; Kolev, Krasimir

    2016-03-01

    Neutrophil extracellular traps (NETs) composed primarily of DNA and histones are a link between infection, inflammation and coagulation. NETs promote coagulation and approaches to destabilise NETs have been explored to reduce thrombosis and treat sepsis. Heparinoids bind histones and we report quantitative studies in plasma and purified systems to better understand physiological consequences. Unfractionated heparin (UFH) was investigated by activated partial thromboplastin time (APTT) and alongside low-molecular-weight heparins (LMWH) in purified systems with thrombin or factor Xa (FXa) and antithrombin (AT) to measure the sensitivity of UFH or LMWH to histones. A method was developed to assess the effectiveness of DNA and non-anticoagulant heparinoids as anti-histones. Histones effectively neutralised UFH, the IC50 value for neutralisation of 0.2 IU/ml UFH was 1.8 µg/ml histones in APTT and 4.6 µg/ml against 0.6 IU/ml UFH in a purified system. Histones also inhibited the activities of LMWHs with thrombin (IC50 6.1 and 11.0 µg/ml histones, for different LMWHs) or FXa (IC50 7.8 and 7.0 µg/ml histones). Direct interactions of UFH and LMWH with DNA and histones were explored by surface plasmon resonance, while rheology studies showed complex effects of histones, UFH and LMWH on clot resilience. A conclusion from these studies is that anticoagulation by UFH and LMWH will be compromised by high affinity binding to circulating histones even in the presence of DNA. A complete understanding of the effects of histones, DNA and heparins on the haemostatic system must include an appreciation of direct effects on fibrin and clot structure.

  15. Contribution of a portable air plasma torch to rapid blood coagulation as a method of preventing bleeding

    International Nuclear Information System (INIS)

    Kuo, S P; Chen, C Y; Fan, H W; Tarasenko, O; Scott, A; Lahiani, M; Alusta, P; Chang, J; Popovic, S; Drake, J D; Nikolic, M

    2009-01-01

    The effectiveness and mechanism of a low temperature air plasma torch in clotting blood are explored. Both blood droplets and smeared blood samples were used in the tests. The treated droplet samples reveal how blood clotting depends on the distance at which the torch operated, and for how long the droplets have been exposed to the torch. Microscopy and cell count of smeared blood samples shed light on dependencies of erythrocyte and platelet counts on torch distance and exposure time. With an increase of torch distance, the platelet count of treated blood samples increases but is less than that of the control. The flux of reactive atomic oxygen (RAO) and the degree of blood clotting decreased. With an increase of exposure time, platelet count of treated samples decreased, while the degree of clot increased. The correlation among these dependencies and published data support a blood clotting mechanism that RAO as well as other likely reactive oxygen species generated by the plasma torch activate erythrocyte-platelets interactions and induces blood coagulation.

  16. Determination of rare-earth elements content in granitic rocks by argon plasma emission spectrometry

    International Nuclear Information System (INIS)

    Merodio, J.C.; Martinez, J.M.

    1990-01-01

    A method has been developed that enables the rare-earth elements in granitic rocks to be measured sequentially, using an inductively coupled plasma (ICP) source spectrometer with medium spectral resolution (0,02nm). The rocks were dissolved in an open system with a mixture of nitric-hydrofluoric-perchloric acids. Any residues remaining at this stage were removed by filtration and digested using a mini-fusion method with lithium tetraborate. Prior to the excitation in the spectrometer the rare-earth group was separated from other constituents using cation-exchange chromatography. A detailed study of spectral interferences and the evaluation of the detection limits have been performed. Five geochemical reference sample (granitic rocks) were analyzed and the obtained results agree favourably with recommended values and with reported determinations, using high spectral resolution ICP spectrometry. (Author) [es

  17. The influence of gas pressure on E↔H mode transition in argon inductively coupled plasmas

    Science.gov (United States)

    Zhang, Xiao; Zhang, Zhong-kai; Cao, Jin-xiang; Liu, Yu; Yu, Peng-cheng

    2018-03-01

    Considering the gas pressure and radio frequency power change, the mode transition of E↔H were investigated in inductively coupled plasmas. It can be found that the transition power has almost the same trend decreasing with gas pressure, whether it is in H mode or E mode. However, the transition density increases slowly with gas pressure from E to H mode. The transition points of E to H mode can be understood by the propagation of electromagnetic wave in the plasma, while the H to E should be illustrated by the electric field strength. Moreover, the electron density, increasing with the pressure and power, can be attributed to the multiple ionization, which changes the energy loss per electron-ion pair created. In addition, the optical emission characteristics in E and H mode is also shown. The line ratio of I750.4 and I811.5, taken as a proxy of the density of metastable state atoms, was used to illustrate the hysteresis. The 750.4 nm line intensity, which has almost the same trend with the 811.5 nm line intensity in H mode, both of them increases with power but decreases with gas pressure. The line ratio of 811.5/750.4 has a different change rule in E mode and H mode, and at the transition point of H to E, it can be one significant factor that results in the hysteresis as the gas pressure change. And compared with the 811.5 nm intensity, it seems like a similar change rule with RF power in E mode. Moreover, some emitted lines with lower rate constants don't turn up in E mode, while can be seen in H mode because the excited state atom density increasing with the electron density.

  18. Plasma diagnostics of the SIMPA Ecr ion source by X-ray spectroscopy, Collisions of H-like Neon ions with Argon clusters; Diagnostic du plasma de la source d'ions ECR SIMPA par spectroscopie X, Collision d'ions neon hydrogenoides avec des agregats d'argon

    Energy Technology Data Exchange (ETDEWEB)

    Adrouche, N

    2006-09-15

    The first part of this thesis is devoted to the SIMPA ECR ion source characterization, first, I explored the ion source's capacities on the point of view of extracted currents for three elements, argon, krypton and neon. By analyzing the Bremsstrahlung spectra, I determined the electronic temperature in the plasma and the electronic and ionic densities. In a second time, I recorded high resolution X-spectra of argon and krypton plasma's. By taking into account the principal mechanisms of production of a K hole in the ions inside the plasma, I determined the ionic densities of the high charge states of argon. Lastly, I highlighted a correlation between the ions charge states densities with the intensities of extracted currents. The second part of the thesis is devoted to Ne{sup 9+-} argon clusters collisions. First, I presented simple and effective theoretical models allowing to describe the phenomena occurring during a collision, from the point of view of the projectile. I carried out a simulation for a collision of an ion Ne{sup 9+} with an argon cluster of a given size, which has enabled us to know the energy levels populated during the electronic capture and to follow the number of electrons in each projectile shell. Lastly, I presented the first results of a collision between a Ne{sup 9+} beam and argon clusters. These results, have enabled me by using projectile X-ray spectroscopy during the ions-clusters collision, to evidence a strong clustering of targets atoms and to highlight an electronic multi-capture in the projectile ion excited states. (author)

  19. Numerical study of the effect of gas temperature on the time for onset of particle nucleation in argon-silane low-pressure plasmas

    CERN Document Server

    Bhandarkar, U; Girshick, S L

    2003-01-01

    Particle nucleation in silane plasmas has attracted interest for the past decade, both due to the basic problems of plasma chemistry involved and the importance of silane plasmas for many applications. A better understanding of particle nucleation may facilitate the avoidance of undesirable particle contamination as well as enable the controlled production of nanoparticles for novel applications. While understanding of particle nucleation has significantly advanced over the past years, a number of questions have not been resolved. Among these is the delay of particle nucleation with an increasing gas temperature, which has been observed in experiments in argon-silane plasmas. We have developed a quasi-one-dimensional model to simulate particle nucleation and growth in silane containing plasmas. In this paper we present a comparative study of the various effects that have been proposed as explanations for the nucleation delay. Our results suggest that the temperature dependence of the Brownian diffusion coeffi...

  20. Comparative study on contribution of charge-transfer collision to excitations of iron ion between argon radio-frequency inductively-coupled plasma and nitrogen microwave induced plasma

    Energy Technology Data Exchange (ETDEWEB)

    Satoh, Kozue; Wagatsuma, Kazuaki, E-mail: wagatuma@imr.tohoku.ac.jp

    2015-06-01

    This paper describes an ionization/excitation phenomenon of singly-ionized iron occurring in an Okamoto-cavity microwave induced plasma (MIP) as well as an argon radio-frequency inductively-coupled plasma (ICP), by comparing the Boltzmann distribution among iron ionic lines (Fe II) having a wide range of the excitation energy from 4.76 to 9.01 eV. It indicated in both the plasmas that plots of Fe II lines having lower excitation energies (4.76 to 5.88 eV) were fitted on each linear relationship, implying that their excitations were caused by a dominant thermal process such as collision with energetic electron. However, Fe II lines having higher excitation energies (more than 7.55 eV) had a different behavior from each other. In the ICP, Boltzmann plots of Fe II lines assigned to the higher excited levels also followed the normal Boltzmann relationship among the low-lying excited levels, even including a deviation from it in particular excited levels having an excitation energy of ca. 7.8 eV. This deviation can be attributed to a charge-transfer collision with argon ion, which results in the overpopulation of these excited levels, but the contribution is small. On the other hand, the distribution of the high-lying excited levels was non-thermal in the Okamoto-cavity MIP, which did not follow the normal Boltzmann relationship among the low-lying excited levels. A probable reason for the non-thermal characteristics in the MIP is that a charge-transfer collision with nitrogen molecule ion having many vibrational/rotational levels could work for populating the 3d{sup 6}4p (3d{sup 5}4s4p) excited levels of iron ion broadly over an energy range of 7.6–9.0 eV, while collisional excitation by energetic electron would occur insufficiently to excite these high-energy levels. - Highlights: • This paper describes the excitation mechanism of iron ion in Okamoto-cavity MIP in comparison with conventional ICP. • Boltzmann distribution is studied among iron ionic lines of

  1. Investigation of local thermodynamic equilibrium of laser induced Al2O3–TiC plasma in argon by spatially resolved optical emission spectroscopy

    Directory of Open Access Journals (Sweden)

    K. Alnama

    2016-06-01

    Full Text Available Plasma plume of Al2O3–TiC is generated by third harmonic Q-switched Nd:YAG nanosecond laser. It is characterized using Optical Emission Spectroscopy (OES at different argon background gas pressures 10, 102, 103, 104 and 105 Pa. Spatial evolution of excitation and ionic temperatures is deduced from spectral data analysis. Temporal evolution of Ti I emission originated from different energy states is probed. The correlation between the temporal behavior and the spatial temperature evolution are investigated under LTE condition for the possibility to use the temporal profile of Ti I emission as an indicator for LTE validity in the plasma.

  2. COAGULATION ACTIVITY IN LIVER DISEASE

    Directory of Open Access Journals (Sweden)

    Dr. Sheikh Sajjadieh Mohammad Reza

    2009-07-01

    Full Text Available Patients with advanced hepatic failure may present with the entire spectrum of coagulation factor deficiencies. This study was designed to determine laboratory abnormalities in coagulation in chronic liver disease and the association of these abnormalities with the extent of chronic hepatitis and cirrhosis. Coagulation markers were assayed in 60 participants: 20 patients with chronic hepatitis, 20 patients with cirrhosis, and 20 healthy individuals (control. Plasma levels of anti-thrombin III were determined by a chromogenic substrate method, and plasma concentrations of fibrinogen were analyzed by the Rutberg method. Commercially available assays were used for laboratory coagulation tests. The levels of coagualation activity markers in patients with chronic liver disease were significantly different in comparison to those in healthy participants. These results indicate the utility of measuring markers for coagulation activity in determining which cirrhosis patients are more susceptible to disseminated intravascular coagulation.

  3. Plasma fractionation for blood products: isolation and purification of coagulating factors, albumin and immunoglobulin

    International Nuclear Information System (INIS)

    Siti Najila Mohd Janib; Shaharuddin Mohd; Wan Hamirul Bahrin Wan Kamal

    2005-01-01

    Approximately 12 million liters of human plasma are fractionated world-wide annually. However, with the market for clotting factors and other haemoderivatives steadily increasing from year to year, the amount processed will also increase correspondingly to keep up with the demand. In Malaysia, part of the need for the blood products are obtained commercially but a major portion of the requirement involves sending the plasma collected by the National Blood Centre to Australia for processing. Following purification and isolation of the blood products, they are sent back to Malaysia for local consumption. As yet there are no plasma fractionation plants in the South East Asia region, it would be advantageous to establish a local fractionation plant as it would be able to cater for local demands of the haemoderivatives and thus reduces the cost of importing these products. Besides, this facility will be able to provide contract fractionation services to the surrounding region. Early work in MINT has started in trying to purify plasma obtained from rats. Purification of the plasma was performed by using Sephadex G-25 column. Short term objective of this project is to develop the technique of extraction, fractionation and purification of blood products such as albumin, globulin and clotting factors (Factor VIII and Factor IX). The long term emphasis will be to scale up the production facility to a pilot plant stage and eventually to a national fractionation and purification plant. (Author)

  4. Measurement of Stark width of some Ar I transitions and the investigation of local thermodynamic equilibrium (LTE) in an atmospheric d.c. argon plasma jet

    International Nuclear Information System (INIS)

    Bakshi, V.

    1988-01-01

    The Stark widths of seven Ar I transitions are reported. Axial line shape data from an atmospheric d.c. argon plasma jet were Abel-inverted to obtain radial line shapes. The electron-density was determined by Stark width measurements of the hydrogen H β transition. In the electron-density region of ≤6 x 10 22 m -3 the experimental Ar I Stark widths are fitted to a linear dependence on the electron-density. Values of Stark width extrapolated to other electron densities are compared to measurements reported in the literature on the 4s-4p array. Experimental values are up to 45% smaller than those predicted by Griem's theory of Stark broadening. Conditions for local thermodynamic equilibrium (LTE) to exist in an atmospheric argon plasma jet were studied. The experiment measures the emission coefficient of seven Ar I transitions and the line shape of the hydrogen H beta transition. After transforming the side-on data into radial space the excited neutral argon atom-density and the electron-density are determined. It is found LTE does not exist below an electron-density of 6 x 10 33 m -3 in the experimental conditions

  5. Dynamics of the spectral behaviour of an ultrashort laser pulse in an argon-gas-filled capillary discharge-preformed plasma channel

    Directory of Open Access Journals (Sweden)

    Sakai S.

    2013-11-01

    Full Text Available We have reported the argon plasma waveguide produced in an alumina (Al2O3 capillary discharge and used to guide ultrashort laser pulses at intensities of the order of 1016  W/cm2. A one-dimensional magnetohydrodynamic (MHD code was used to evaluate the average degree of ionization of Ar in the preformed plasma channel. The spectrum of the propagated laser pulse in the Ar plasma waveguide was not modified and was well reproduced by a particle-in-cell (PIC simulation under initial ion charge state of Ar3+ in the preformed plasma waveguide. The optimum timing for the laser pulse injection was around 150 ns after initiation of a discharge with a peak current of 200 A.

  6. Improvement of In-Flight Alumina Spheroidization Process Using a Small Power Argon DC-RF Hybrid Plasma Flow System by Helium Mixture

    Science.gov (United States)

    Takana, Hidemasa; Jang, Juyong; Igawa, Junji; Nakajima, Tomoki; Solonenko, Oleg P.; Nishiyama, Hideya

    2011-03-01

    For the further improvement of in-flight alumina spheroidization process with a low-power direct-current radiofrequency (DC-RF) hybrid plasma flow system, the effect of a small amount of helium gas mixture in argon main gas and also the effect of increasing DC nozzle diameter on powder spheroidization ratio have been experimentally clarified with correlating helium gas mixture percentage, plasma enthalpy, powder in-flight velocity, and temperature. The alumina spheroidization ratio increases by helium gas mixture as a result of enhancement of plasma enthalpy. The highest spheroidization ratio is obtained by 4% mixture of helium in central gas with enlarging nozzle diameter from 3 to 4 mm, even under the constant low input electric power given to a DC-RF hybrid plasma flow system.

  7. Investigations of the cathode region of an argon arc plasma by degenerate four-wave mixing laser spectroscopy and optical emission spectroscopy

    International Nuclear Information System (INIS)

    Dzierzega, K; Pokrzywka, B; Pellerin, S

    2004-01-01

    Degenerate four-wave mixing (DFWM) laser spectroscopy was used in local studies of atmospheric pressure argon plasma generated in a free-burning arc. The results of plasma diagnostics using the DFWM method were compared to the results obtained with optical emission measurements. In the cathode region of the arc the maxima of both the DFWM signal and the emission coefficient for the 696.5 nm Ar I line depend on the distance from the cathode tip. This effect proves the departure of the plasma state from local thermal equilibrium (LTE) as it has been reported by many authors. On the other hand the Stark shifts of the 696.5 nm Ar I line determined by the DFWM method in relation to plasma diagnostic results show no deviations from LTE on the arc axis down to 1.0 mm from the cathode tip

  8. Temporal and spatial dynamics of laser-induced aluminum plasma in argon background at atmospheric pressure: Interplay with the ambient gas

    International Nuclear Information System (INIS)

    Ma, Q.L.; Motto-Ros, V.; Lei, W.Q.; Boueri, M.; Bai, X.S.; Zheng, L.J.; Zeng, H.P.; Yu, J.

    2010-01-01

    Laser ablation in background gas implies supplementary complexities with respect to what happens in the vacuum. It is however essential to understand in detail the involved mechanisms for a number of applications requiring the ablation to be performed in an ambient gas at relative high pressure, such as pulsed-laser deposition, or laser-induced breakdown spectroscopy. In this paper, the expansion of a vapor plume ablated from an aluminum target into an argon gas at atmospheric pressure is experimentally investigated using time- and space-resolved emission spectroscopy. The obtained results provide a detailed description of the interplay between the vapor and the gas. The electron density, the temperature and the number densities (and therefore the partial pressures) of aluminum vapor and argon gas have been measured in and surrounding the vapor plume. Our observations show a confinement of the vapor plume by the gas, which is expected as predicted by the usual hydrodynamics models. The result is a plasma core with quite uniform distributions in electron density, temperature and number densities. Such plasma core presents an ideal emission source for spectroscopic applications. It is however evidenced by our observations that a large amount of argon is mixed into the aluminum plume in the plasma core, which invalidates in the experimental conditions that we used, the hydrodynamic 'piston' model where the background gas is pushed out by the shock wave surrounding the vapor plume. Instead, other mechanisms such as laser-supported detonation wave should play important roles in the early stage of the expansion of the plasma for the determination of its morphology at longer delays.

  9. Inhibitory effect of double atmospheric pressure argon cold plasma on spores and mycotoxin production of Aspergillus niger contaminating date palm fruits.

    Science.gov (United States)

    Ouf, Salama A; Basher, Abdulrahman H; Mohamed, Abdel-Aleam H

    2015-12-01

    Aspergillus niger has been reported as a potentially dangerous pathogen of date-palm fruits in Saudi Arabia due to the production of fumonisin B2 (FB2 ) and ochratoxin A (OTA). In a trial to disinfect this product, a double atmospheric pressure argon cold plasma (DAPACP) jet system was set up and evaluated against spore germination and mycotoxin production of the pathogen. The plasma jets were characterised photographically, electrically and spectroscopically. DAPACP jet length increases with the increase of argon flow rate, with optimum rate at 3.5 L min(-1) . The viability of A. niger spores, inoculated onto sterilised date palm fruit discs, progressively decreases with extension of the exposure time of DAPACP due to the more quantitative amount of OH and O radicals interacting with the examined samples. There was a progressive reduction of the amount of FB2 and OTA detected in date palm discs on extension of the exposure time of the plasma-treated inoculums at flow rate of 3.5 L min(-1) . FB2 was not detected in the discs inoculated with 6-min plasma-treated A. niger, while OTA was completely absent when the fungus was treated for 7.5 min. DAPACP showed promising results in dry fruit decontamination and in inhibition of mycotoxin release by A. niger contaminating the fruits. The progress in the commercial application of cold plasma needs further investigation concerning the ideal width of the plasma output to enable it to cover wider surfaces of the sample and consequently inducing greater plasma performance. © 2014 Society of Chemical Industry.

  10. APLICACIÓN DEL MÉTODO DE COÁGULO DE PLASMA PARA ESTUDIOS DE ULTRAESTRUCTURA CELULAR APPLICATION OF PLASMA COAGULATE METHOD FOR CELULAR ULTRASTRUCTURE STUDIES

    Directory of Open Access Journals (Sweden)

    GERARDO ANDRÉS TORRES RODRÍGUEZ

    2009-06-01

    Full Text Available Los estudios de ultraestructura celular en material particulado como bacterias, virus y células en suspensión requieren de un manejo especial, es por esto que se han desarrollado técnicas como la de coágulo de plasma, la cual se aplicó en un modelo experimental de fagocitosis. Se realizaron análisis de Microscopia Electrónica de Transmisión y de Barrido observándose claramente cuatro etapas de la fagocitosis. Se consideró una relación de 10 partículas de levadura por PMN como la proporción más eficiente para la observación del proceso fagocítico, igualmente se determinó muy corto el periodo de incubación de 20 minutos para alcanzar la fagocitosis en su totalidad. La técnica del coágulo de plasma mostró muy buenos resultados en preparaciones para TEM conservando la integridad de las células, no obstante, esta técnica presentó inconvenientes al observarse en MEB debido a los componentes fibrosos del coágulo que impiden una observación de la muestra, adhiriéndose a las superficies produciendo artefactos y deterioro en éstas.Studying ultrastructure cell in particle material such as bacteria, virus and cells suspension require special handling. For that reason, it has been developed techniques like plasma coagulate with phagocytosis as experimental model and analyzed by transmission electronic microscopy (TEM and scanning electronic microscopy (SEM. Four stages of phagocytosis were observed. The efficient proportion to observe the phagocytosis process was 10 particles per NPM (Nuclear Polymorphic, although 20 min as a incubation period was very short to reaching the total process. Applying this technique, cells conserved their integrity to obtain good quality preparation for TEM. In contrast for SEM samples which kept coagulate fiber components adhered to the surface, producing devices and cell deterioration was observed.

  11. Immunoblotting studies of coagulation factor XII, plasma prekallikrein, and high molecular weight kininogen

    International Nuclear Information System (INIS)

    Laemmle, B.B.; Berrettini, M.; Griffin, J.H.

    1987-01-01

    Immunoblotting techniques for the qualitative and quantitative analysis of FXII, PK, and HMWK in whole plasma are presented. Sensitive, specific, and quantitative immunodetection of FXII and PK can be achieved by developing the blots with polyclonal antiserum followed by radiolabeled FXII or PK, respectively. This approach is based on the assumption that bivalent antibodies bind monovalently to the NC-bound antigen and have available binding sites to bind radiolabeled antigen derived from the fluid phase. This radiolabeled antigen overlay principle may be generally useful for immunodetection of any trace protein in complex mixtures, provided that the radiolabeled purified antigen is available. Immunoblotting may also be helpful for the partial characterization of the structural or functional abnormalities of CRM-positive variant molecules. For example, earlier studies of a FXII-variant molecule that had been purified and characterized were supported by immunoblotting studies of the CRM-positive deficient plasma. Quantitative measurement of HMWK is possible using a monoclonal antibody directed against the light chain of HMWK followed by radiolabeled secondary antibody. Quantitation of cleaved and single-chain HMWK is possible using dilutions of dextran sulfate-activated NHP on unreduced SDS-PAGE and dilutions of unactivated NHP with reduced SDS-PAGE as standards. These assays allow assessment of the degree of in vivo activation of the contact system in various disease states

  12. High-performance liquid chromatographic separation of biologically important arsenic species utilizing on-line inductively coupled argon plasma atomic emission spectrometric detection

    Energy Technology Data Exchange (ETDEWEB)

    Spall, W.D.; Lynn, J.G.; Andersen, J.L.; Valdez, J.G.; Gurley, L.R.

    1986-06-01

    An anion exchange, high-performance liquid chromatography technique using a 15-min linear gradient from water to 0.5 M ammonium carbonate to separate arsenite, arsenate, methylarsonic acid, and dimethylarsinic acid from neutral arsenic containing compounds was developed for application to a study of arsenic metabolism in cultured cell suspensions. Arsenic detection was accomplished by the direct coupling of the column effluent to an inductively coupled argon plasma atomic emission spectrometer (ICAP-AES) set to monitor the arsenic emission line at 197.19 nm. The analysis requires 20 min and is sensitive to as low as 60 ng of arsenic injected to the column.

  13. Relative effects of plasma, fibrinogen concentrate, and factor XIII on ROTEM coagulation profiles in an in vitro model of massive transfusion in trauma.

    Science.gov (United States)

    Schmidt, David E; Halmin, Märit; Wikman, Agneta; Östlund, Anders; Ågren, Anna

    2017-10-01

    Massive traumatic haemorrhage is aggravated through the development of trauma-induced coagulopathy, which is managed by plasma transfusion and/or fibrinogen concentrate administration. It is yet unclear whether these treatments are equally potent in ensuring adequate haemostasis, and whether additional factor XIII (FXIII) administration provides further benefits. In this study, we compared ROTEM whole blood coagulation profiles after experimental massive transfusion with different transfusion regimens in an in vitro model of dilution- and transfusion-related coagulopathy. Healthy donor blood was mixed 1 + 1 with six different transfusion regimens. Each regimen contained RBC, platelet concentrate, and either fresh frozen plasma (FFP) or Ringer's acetate (RA). The regimens were further augmented through addition of a low- or medium-dose fibrinogen concentrate and FXIII. Transfusion with FFP alone was insufficient to maintain tissue-factor activated clot strength, coincidental with a deficiency in fibrin-based clot strength. Fibrinogen concentrate conserved, but did not improve coagulation kinetics and overall clot strength. Only combination therapy with FFP and low-dose fibrinogen concentrate improved both coagulation kinetics and fibrin-based clot strength. Administration of FXIII did not result in an improvement of clot strength. In conclusion, combination therapy with both FFP and low-dose fibrinogen concentrate improved clotting time and produced firm clots, representing a possible preferred first-line regimen to manage trauma-induced coagulopathy when RBC and platelets are also transfused. Further research is required to identify optimal first-line transfusion fluids for massive traumatic haemorrhage.

  14. An investigation of Ar metastable state density in low pressure dual-frequency capacitively coupled argon and argon-diluted plasmas

    International Nuclear Information System (INIS)

    Liu, Wen-Yao; Xu, Yong; Peng, Fei; Guo, Qian; Li, Xiao-Song; Zhu, Ai-Min; Liu, Yong-Xin; Wang, You-Nian

    2015-01-01

    An tunable diode laser absorption spectroscopy has been used to determine the Ar*( 3 P 2 ) and Ar*( 3 P 0 ) metastable atoms densities in dual-frequency capacitively coupled plasmas. The effects of different control parameters, such as high-frequency power, gas pressure and content of Ar, on the densities of two metastable atoms and electron density were discussed in single-frequency and dual-frequency Ar discharges, respectively. Particularly, the effects of the pressure on the axial profile of the electron and Ar metastable state densities were also discussed. Furthermore, a simple rate model was employed and its results were compared with experiments to analyze the main production and loss processes of Ar metastable states. It is found that Ar metastable state is mainly produced by electron impact excitation from the ground state, and decayed by diffusion and collision quenching with electrons and neutral molecules. Besides, the addition of CF 4 was found to significantly increase the metastable destruction rate by the CF 4 quenching, especially for large CF 4 content and high pressure, it becomes the dominant depopulation process

  15. Influence of the excited states on the electron-energy distribution function in low-pressure microwave argon plasmas

    International Nuclear Information System (INIS)

    Yanguas-Gil, A.; Cotrino, J.; Gonzalez-Elipe, A.R.

    2005-01-01

    In this work the influence of the excited states on the electron-energy distribution function has been determined for an argon microwave discharge at low pressure. A collisional-radiative model of argon has been developed taking into account the most recent experimental and theoretical values of argon-electron-impact excitation cross sections. The model has been solved along with the electron Boltzmann equation in order to study the influence of the inelastic collisions from the argon excited states on the electron-energy distribution function. Results show that under certain conditions the excited states can play an important role in determining the shape of the distribution function and the mean kinetic energy of the electrons, deplecting the high-energy tail due to inelastic processes from the excited states, especially from the 4s excited configuration. It has been found that from the populations of the excited states an excitation temperature can be defined. This excitation temperature, which can be experimentally determined by optical emission spectroscopy, is lower than the electron kinetic temperature obtained from the electron-energy distribution function

  16. Effects of anti-aggregant, anti-inflammatory and anti-coagulant drug consumption on the preparation and therapeutic potential of plasma rich in growth factors (PRGF).

    Science.gov (United States)

    Anitua, Eduardo; Troya, María; Zalduendo, Mar; Orive, Gorka

    2015-02-01

    The prevalence and incidence of trauma-related injuries, coronary heart disease and other chronic diseases increase dramatically with age. This population sector is therefore a regular consumer of different types of drugs that may affect platelet aggregation and the coagulation cascade. We have evaluated whether the consumption of acetylsalicylic acid, acenocoumarol, glucosamine sulfate and chondroitin sulfate, and therefore their presence in blood, could interfere with the preparation and biological outcomes of plasma rich in growth factors (PRGF). Clotting time, clot retraction and platelet activation of PRGF was evaluated. PRGF growth factor content and the release of different biomolecules by tendon fibroblasts were also quantified, as well as cell proliferation and cell migration. The preparation and biological potential of PRGF is not affected by the intake of the evaluated drugs, and solely its angiogenic potential and its capacity to induce HA and fibronectin synthesis, is reduced in patients taking anti-coagulants.

  17. High plasma homocyst(e)ine levels in elderly Japanese patients are associated with increased cardiovascular disease risk independently from markers of coagulation activation and endothelial cell damage.

    Science.gov (United States)

    Kario, K; Duell, P B; Matsuo, T; Sakata, T; Kato, H; Shimada, K; Miyata, T

    2001-08-01

    Elevated plasma homocyst(e)ine is a risk factor for cardiovascular disease (CVD) in many populations, but the relationship between homocyst(e)ine and CVD in Japanese subjects has been unclear. It has been hypothesized that the link between homocyst(e)ine and CVD may be mediated in part by activation of coagulation and endothelial cell injury in the elderly Japanese subjects. To further evaluate this hypothesis, the present cross-sectional study was designed to assess the relationships among plasma homocyst(e)ine concentrations, risk of CVD, and markers of coagulation (fibrinogen, FVII, F1+2, FVIIa and FXIIa) and endothelial cell damage (vWF and thrombomodulin) in 146 elderly Japanese subjects (79 healthy controls and 67 patients with CVD). The geometric mean (range) of plasma homocyst(e)ine concentrations was 10.2 (3.2--33) micromol/l in 79 Japanese healthy elderly subjects. As expected, healthy female and male elderly subjects had homocyst(e)ine levels that were 2.5 and 5.3 micromol/; higher, respectively, compared to healthy young control subjects (n=62). Healthy young and elderly men had homocyst(e)ine levels that were 1.7 and 4.5 micromol/l higher, respectively, compared to values in women. This higher plasma homocyst(e)ine levels in the elderly subjects were negatively correlated with levels of folic acid, albumin and total cholesterol, but were not significantly related to markers of coagulation or endothelial cell-damage. The results of multiple logistic regression analyses suggested that high homocyst(e)ine levels were independently related to CVD risk. In addition, levels of FVIIa, and F1+2 were significantly higher in elderly Japanese patients with CVD compared to elderly subjects without CVD, but were unrelated to plasma homocyst(e)ine concentrations. In summary, elevated plasma concentrations of homocyst(e)ine, FVIIa, and F1+2 were associated with increased risk of CVD in elderly male and female Japanese subjects, but the association between homocyst

  18. Ultraviolet versus infrared: Effects of ablation laser wavelength on the expansion of laser-induced plasma into one-atmosphere argon gas

    International Nuclear Information System (INIS)

    Ma Qianli; Motto-Ros, Vincent; Laye, Fabrice; Yu Jin; Lei Wenqi; Bai Xueshi; Zheng Lijuan; Zeng Heping

    2012-01-01

    Laser-induced plasma from an aluminum target in one-atmosphere argon background has been investigated with ablation using nanosecond ultraviolet (UV: 355 nm) or infrared (IR: 1064 nm) laser pulses. Time- and space-resolved emission spectroscopy was used as a diagnostics tool to have access to the plasma parameters during its propagation into the background, such as optical emission intensity, electron density, and temperature. The specific feature of nanosecond laser ablation is that the pulse duration is significantly longer than the initiation time of the plasma. Laser-supported absorption wave due to post-ablation absorption of the laser radiation by the vapor plume and the shocked background gas plays a dominant role in the propagation and subsequently the behavior of the plasma. We demonstrate that the difference in absorption rate between UV and IR radiations leads to different propagation behaviors of the plasma produced with these radiations. The consequence is that higher electron density and temperature are observed for UV ablation. While for IR ablation, the plasma is found with lower electron density and temperature in a larger and more homogenous axial profile. The difference is also that for UV ablation, the background gas is principally evacuated by the expansion of the vapor plume as predicted by the standard piston model. While for IR ablation, the background gas is effectively mixed to the ejected vapor at least hundreds of nanoseconds after the initiation of the plasma. Our observations suggest a description by laser-supported combustion wave for the propagation of the plasma produced by UV laser, while that by laser-supported detonation wave for the propagation of the plasma produced by IR laser. Finally, practical consequences of specific expansion behavior for UV or IR ablation are discussed in terms of analytical performance promised by corresponding plasmas for application with laser-induced breakdown spectroscopy.

  19. Study on the effect of hydrogen addition on the variation of plasma parameters of argon-oxygen magnetron glow discharge for synthesis of TiO2 films

    Directory of Open Access Journals (Sweden)

    Partha Saikia

    2016-04-01

    Full Text Available We report the effect of hydrogen addition on plasma parameters of argon-oxygen magnetron glow discharge plasma in the synthesis of H-doped TiO2 films. The parameters of the hydrogen-added Ar/O2 plasma influence the properties and the structural phases of the deposited TiO2 film. Therefore, the variation of plasma parameters such as electron temperature (Te, electron density (ne, ion density (ni, degree of ionization of Ar and degree of dissociation of H2 as a function of hydrogen content in the discharge is studied. Langmuir probe and Optical emission spectroscopy are used to characterize the plasma. On the basis of the different reactions in the gas phase of the magnetron discharge, the variation of plasma parameters and sputtering rate are explained. It is observed that the electron and heavy ion density decline with gradual addition of hydrogen in the discharge. Hydrogen addition significantly changes the degree of ionization of Ar which influences the structural phases of the TiO2 film.

  20. Gas barrier properties of hydrogenated amorphous carbon films coated on polyethylene terephthalate by plasma polymerization in argon/n-hexane gas mixture

    Energy Technology Data Exchange (ETDEWEB)

    Polonskyi, Oleksandr; Kylián, Ondřej, E-mail: ondrej.kylian@gmail.com; Petr, Martin; Choukourov, Andrei; Hanuš, Jan; Biederman, Hynek

    2013-07-01

    Hydrogenated amorphous carbon thin films were deposited by RF plasma polymerization in argon/n-hexane gas mixture on polyethylene terephthalate (PET) foils. It was found that such deposited films may significantly improve the barrier properties of PET. It was demonstrated that the principal parameter that influences barrier properties of such deposited films towards oxygen and water vapor is the density of the coatings. Moreover, it was shown that for achieving good barrier properties it is advantageous to deposit coatings with very low thickness. According to the presented results, optimal thickness of the coating should not be higher than several tens of nm. - Highlights: • a-C:H films were prepared by plasma polymerization in Ar/n-hexane atmosphere. • Barrier properties of coatings are dependent on their density and thickness. • Highest barrier properties were observed for films with thickness 15 nm.

  1. Deviation from Boltzmann distribution in excited energy levels of singly-ionized iron in an argon glow discharge plasma for atomic emission spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Lei; Kashiwakura, Shunsuke; Wagatsuma, Kazuaki, E-mail: wagatuma@imr.tohoku.ac.jp

    2012-01-15

    A Boltzmann plot for many iron ionic lines having excitation energies of 4.7-9.1 eV was investigated in an argon glow discharge plasma when the discharge parameters, such as the voltage/current and the gas pressure, were varied. A Grimm-style radiation source was employed in a DC voltage range of 400-800 V at argon pressures of 400-930 Pa. The plot did not follow a linear relationship over a wide range of the excitation energy, but it yielded a normal Boltzmann distribution in the range of 4.7-5.8 eV and a large overpopulation in higher-lying excitation levels of iron ion. A probable reason for this phenomenon is that excitations for higher excited energy levels of iron ion would be predominantly caused by non-thermal collisions with argon species, the internal energy of which is received by iron atoms for the ionization. Particular intense ionic lines, which gave a maximum peak of the Boltzmann plot, were observed at an excitation energy of ca. 7.7 eV. They were the Fe II 257.297-nm and the Fe II 258.111-nm lines, derived from the 3d{sup 5}4s4p {sup 6}P excited levels. The 3d{sup 5}4s4p {sup 6}P excited levels can be highly populated through a resonance charge transfer from the ground state of argon ion, because of good matching in the excitation energy as well as the conservation of the total spin before and after the collision. An enhancement factor of the emission intensity for various Fe II lines could be obtained from a deviation from the normal Boltzmann plot, which comprised the emission lines of 4.7-5.8 eV. It would roughly correspond to a contribution of the charge transfer excitation to the excited levels of iron ion, suggesting that the charge-transfer collision could elevate the number density of the corresponding excited levels by a factor of ca.10{sup 4}. The Boltzmann plots give important information on the reason why a variety of iron ionic lines can be emitted from glow discharge plasmas.

  2. Magnetic properties of Co-N films deposited by ECR nitrogen/argon plasma with DC negative-biased Co target

    Energy Technology Data Exchange (ETDEWEB)

    Li, H.; Zhang, Y.C.; Yang, K.; Liu, H.X.; Zhu, X.D., E-mail: xdzhu@ustc.edu.cn; Zhou, H.Y.

    2017-06-01

    Highlights: • A new method of synthesizing Co-N films containing Co{sub 4}N phase. • Tunable magnetic properties achieved in ECR plasma CVD. • The change of magnetic properties is related to atoms mobility on substrate and the concentration of active species in plasma vapor. - Abstract: By introducing DC negative-biased Co target in the Electron Cyclotron Resonance (ECR) nitrogen/argon plasma, the Co-N films containing Co{sub 4}N phase were synthesized on Si(100) substrate. Effects of processing parameters on magnetic properties of the films are investigated. It is found that magnetic properties of Co-N films vary with N{sub 2}/Ar flow ratio, substrate temperature, and target biasing voltage. The saturation magnetization M{sub s} decreased by increasing the N{sub 2}/Ar gas flow ratio or decreasing target biasing voltage, while the coercive field H{sub c} increased, which is ascribed to the variation of relative concentration for N or Co active species in plasma vapor. The magnetic properties present complex dependency with growth temperature, which is related to the atom mobility on the substrate affected by the growth temperature. This study exhibits a potential of ECR plasma chemical vapor deposition to synthesize the interstitial compounds and tune magnetic properties of films.

  3. Type of precursor and synthesis of silicon oxycarbide (SiOxCyH) thin films with a surfatron microwave oxygen/argon plasma

    International Nuclear Information System (INIS)

    Walkiewicz-Pietrzykowska, Agnieszka; Espinos, J. P.; Gonzalez-Elipe, Agustin R.

    2006-01-01

    Siliconelike thin films (i.e., SiO x C y H z ) were prepared in a microwave plasma enhanced chemical vapor deposition reactor from structurally different organosilicon precursors [i.e., hexamethyldisiloxane (HMDSO), dimethylsilane (DMS), and tetramethylsilane (TMS)]. The films were deposited at room temperature by using different oxygen/argon ratios in the plasma gas. By changing the type of precursor and the relative concentration of oxygen in the plasma, thin films with different compositions (i.e., O/C ratio) and properties are obtained. In general, raising the oxygen concentration in the plasma produces the progressive removal of the organic moieties from the films whose composition and structure then approach those of silicon dioxide. The deposition rate was highly dependent on the type of precursor, following the order HMDSO>>DMS>TMS. The polarizabilities, optical band gaps, and surface free energy of the films also depended on the thin film composition and structure. It is proposed that the Si-O bonds existing in HMDSO is the main factor controlling the distinct reactivity of this precursor and is also responsible for the different compositions and properties of the SiO x C y H z thin films prepared with very low or no oxygen in the plasma gas

  4. The protein concentration of blood coagulation factor VII can be measured equally well in plasma and serum

    DEFF Research Database (Denmark)

    Bladbjerg, E-M; Overgaard, K; Gram, J

    1995-01-01

    In the Northwick Park Heart Study, the coagulant activity of factor VII (FVII:C) has been identified as a risk marker of ischaemic heart disease. In the fasting state, the protein concentration of FVII (FVII:Ag) might be an even better risk marker, because of the low coefficient of variation...

  5. Laser Induced Fluorescence (LIF) Measurements of Neutral (ArI) and singly-ionized (ArII) Argon in a LargeScale Helicon Plasma

    Science.gov (United States)

    Kelly, R. F.; Fisher, D. M.; Hatch, M. W.; Gilmore, M.; Dwyer, R. H.; Meany, K.; Zhang, Y.; Desjardins, T. R.

    2017-10-01

    In order to investigate the role of neutral dynamics in helicon discharges in the HelCat (Helicon-Cathode) plasma device at U. New Mexico, a Laser Induced Fluorescence (LIF) system has been developed. The LIF system is based on a >250 mW, tunable diode laser with a tuning range between 680 and 700nm. For neutral Argon, the laser pumps the metastable (2P3/20) 4s level to the (2P1/20) 4p level using 696. 7352 nm light. The fluorescence radiation from decay to the (2P1/20) 4s level at 772. 6333 nm is observed. For singly ionized Argon, the laser pumps the 3s23p4(3 P)3d level to the 3s23p4(3 P)4p level using 686.3162nm light. The fluorescence radiation from the decay to the 3s23p4(3 P)4s level is observed. The system design, and velocity measurements in the axial, azimuthal and radial directions for ArI, and in the axial direction for ArII will be presented. Supported by U.S. National Science Foundation Award 1500423.

  6. Investigation into the behavior of metal-argon polyatomic ions (MAr+) in the extraction region of inductively coupled plasma-mass spectrometry

    International Nuclear Information System (INIS)

    Ebert, Chris H.; Witte, Travis M.; Houk, R.S.

    2012-01-01

    The abundances of metal-argon polyatomic ions (MAr + ) are determined in inductively coupled plasma-mass spectrometry (ICP-MS). The ratios of MAr + abundance to that for M + ions are measured experimentally. These ratios are compared to expected values, calculated for typical plasma conditions using spectroscopic data. For all metals studied (Ti, V, Cr, Mn, Fe, Co, Ni, Cu, and Zn), the measured ratios are significantly lower than the calculated ratios. Increasing the plasma potential (and thereby increasing the ion kinetic energy) by means of a homemade guard electrode with a wide gap further reduces the MAr + /M + ratio. Implementing a skimmer cone designed for high transmission of light ions increases the MAr + abundance. Considering this evidence, the scarcity of MAr + ions is attributed to collision induced dissociation (CID), likely due to a shock wave at the tip of or in the throat of the skimmer cone. - Highlights: ► MAr + ions are less abundant in the mass spectrum than expected from the ICP. ► Increasing the plasma potential reduces their abundance further. ► The extraction lens voltage does not greatly affect the MAr + abundances. ► The weakly-bound MAr + ions are probably dissociated by collisions during extraction.

  7. Fouling behavior of poly(ether)sulfone ultrafiltration membrane during concentration of whey proteins: Effect of hydrophilic modification using atmospheric pressure argon jet plasma.

    Science.gov (United States)

    Damar Huner, Irem; Gulec, Haci Ali

    2017-12-01

    The aim of the study was to investigate the effects of hydrophilic surface modification via atmospheric pressure jet plasma (ApJPls) on the fouling propensity of polyethersulfone (PES) ultrafiltration (UF) membranes during concentration of whey proteins. The distance from nozzle to substrate surface of 30mm and the exposure period of 5 times were determined as the most effective parameters enabling an increase in ΔG iwi value of the plain membrane from (-) 14.92±0.89mJ/m 2 to (+) 17.57±0.67mJ/m 2 . Maximum hydrophilicity and minimum surface roughness achieved by argon plasma action resulted in better antifouling behavior, while the hydraulic permeability and the initial permeate flux were decreased sharply due to the plasma-induced surface cross-linking. A quite steady state flux was obtained throughout the UF with the ApJPls modified PES membrane. The contribution of R frev to R t , which was 94% for the UF through the plain membrane, decreased to 43% after the plasma treatment. The overall results of this study highlighted the ApJPls modification decreased the fouling propensity of PES membrane without affecting the original protein rejection capability and improved the recovery of initial permeate flux after chemical cleaning. Copyright © 2017 Elsevier B.V. All rights reserved.

  8. On local thermal equilibrium and potential gradient vs current characteristic in wall-stabilized argon plasma arc at 0.1 atm pressure

    International Nuclear Information System (INIS)

    Shindo, Haruo; Imazu, Shingo; Inaba, Tsuginori.

    1979-01-01

    In wall-stabilized arc which is a very useful means for determining the transport characteristics of high temperature gases, it is the premise that the inside of arc column is in complete local thermal equilibrium (LTE). In general, the higher the gas pressure, the easier the establishment of LTE, accordingly the experimental investigations on the characteristics of arc discharge as well as the transport characteristics so far were limited to the region of relatively high pressure. However, the authors have found that the theoretical potential vs. current characteristic obtained by the transport characteristic was greatly different from the actually measured one in low pressure region, as the fundamental characteristic of wall-stabilized argon plasma arc below atmospheric pressure. This time, they have clarified this discrepancy at 0.1 atm using the plasma parameters obtained through the spectroscopic measurements. The spectroscopic measurements have been performed through the side observation window at the position 5.5 cm away from the cathode, when arc was ignited vertically at the electrodes distant by 11 cm. Arc radius was 0.5 cm. Electron density and temperature, gas temperature and the excitation density of argon neutral atoms have been experimentally measured. The investigations showed that, in the region of low arc current, where the ratio of current to arc radius is less than 200 A/cm, the fall of gas temperature affected greatly on the decrease of axial electric field of arc column. The non-equilibrium between electron temperature and gas temperature decreased with the increase of arc current, and it was concluded that LTE has been formed at the center portion of arc column above I/R = 300 A/cm. (Wakatsuki, Y.)

  9. UPLC-MRM Mass Spectrometry Method for Measurement of the Coagulation Inhibitors Dabigatran and Rivaroxaban in Human Plasma and Its Comparison with Functional Assays.

    Science.gov (United States)

    Kuhn, Joachim; Gripp, Tatjana; Flieder, Tobias; Dittrich, Marcus; Hendig, Doris; Busse, Jessica; Knabbe, Cornelius; Birschmann, Ingvild

    2015-01-01

    The fast, precise, and accurate measurement of the new generation of oral anticoagulants such as dabigatran and rivaroxaban in patients' plasma my provide important information in different clinical circumstances such as in the case of suspicion of overdose, when patients switch from existing oral anticoagulant, in patients with hepatic or renal impairment, by concomitant use of interaction drugs, or to assess anticoagulant concentration in patients' blood before major surgery. Here, we describe a quick and precise method to measure the coagulation inhibitors dabigatran and rivaroxaban using ultra-performance liquid chromatography electrospray ionization-tandem mass spectrometry in multiple reactions monitoring (MRM) mode (UPLC-MRM MS). Internal standards (ISs) were added to the sample and after protein precipitation; the sample was separated on a reverse phase column. After ionization of the analytes the ions were detected using electrospray ionization-tandem mass spectrometry. Run time was 2.5 minutes per injection. Ion suppression was characterized by means of post-column infusion. The calibration curves of dabigatran and rivaroxaban were linear over the working range between 0.8 and 800 μg/L (r >0.99). Limits of detection (LOD) in the plasma matrix were 0.21 μg/L for dabigatran and 0.34 μg/L for rivaroxaban, and lower limits of quantification (LLOQ) in the plasma matrix were 0.46 μg/L for dabigatran and 0.54 μg/L for rivaroxaban. The intraassay coefficients of variation (CVs) for dabigatran and rivaroxaban were method comparison between our UPLC-MRM MS method, the commercially available automated Direct Thrombin Inhibitor assay (DTI assay) for dabigatran measurement from CoaChrom Diagnostica, as well as the automated anti-Xa assay for rivaroxaban measurement from Chromogenix both performed by ACL-TOP showed a high degree of correlation. However, UPLC-MRM MS measurement of dabigatran and rivaroxaban has a much better selectivity than classical functional

  10. A new flexible DBD device for treating infected wounds: in vitro and ex vivo evaluation and comparison with a RF argon plasma jet

    International Nuclear Information System (INIS)

    Boekema, B K H L; Vlig, M; Guijt, D; Middelkoop, E; Hijnen, K; Hofmann, S; Smits, P; Sobota, A; Van Veldhuizen, E M; Bruggeman, P

    2016-01-01

    Cold plasma has been shown to provide a promising alternative antimicrobial treatment for wound healing. We developed and tested a flexible surface dielectric barrier discharge (DBD) and compared it to an argon gas based plasma jet operated remotely with a distance between plasma plume and sample of 8 mm. Tests were conducted using different models: on cultured cells, on ex vivo human skin and on bacteria (Pseudomonas aeruginosa) (on agar, in suspension, in collagen/elastin matrix or on ex vivo human skin), allowing us to directly compare bactericidal with safety aspects under identical conditions. Both plasma devices were highly efficient when used on bacteria in non-buffered solutions, but DBD was faster in reaching the maximum bacterial reduction. Treatment of bacteria on intact skin with DBD resulted in up to 6 log reductions in 3 min. The jet was far less efficient on intact skin. Even after 8 min treatment no more than 2 log reductions were obtained with the jet. Treatment of bacteria in burn wound models with DBD for 6 min resulted in a 4.5 log reduction. Even when using DBD for 6 min on infected burn wound models with colonizing or biofilm phase bacteria, the log reductions were 3.8 or 3.2 respectively. DBD plasma treatment for 6 min did not affect fibroblast viability, whereas a treatment for 8 min was detrimental. Similarly, treatment with DBD or plasma jet for 6 min did also not affect the metabolic activity of skin biopsies. After treatment for 8 min with DBD or plasma jet, 78% or 60% of activity in skin biopsies remained, respectively. Multiple treatments of in vitro burn wound models with surface DBD for 6 min or with plasma jet for 8 min did not affect re-epithelialization. With the flexible surface DBD plasma strip we were able to quickly inactivate large numbers of bacteria on and in skin. Under the same conditions, viability of skin cells or re-epithelialization was not affected. The DBD source has potential for treating

  11. Spectroscopy of reactive species produced by low-energy atmospheric-pressure plasma on conductive target material surface

    International Nuclear Information System (INIS)

    Yamada, Hiromasa; Sakakita, Hajime; Kato, Susumu; Kim, Jaeho; Kiyama, Satoru; Fujiwara, Masanori; Itagaki, Hirotomo; Ikehara, Yuzuru; Okazaki, Toshiya; Ikehara, Sanae; Nakanishi, Hayao; Shimizu, Nobuyuki

    2016-01-01

    A method for blood coagulation using low-energy atmospheric-pressure plasma (LEAPP) is confirmed as an alternative procedure to reduce tissue damage caused by heat. Blood coagulation using LEAPP behaves differently depending on working gas species; helium is more effective than argon in promoting fast coagulation. To analyse the difference in reactive species produced by helium and argon plasma, spectroscopic measurements were conducted without and with a target material. To compare emissions, blood coagulation experiments using LEAPP for both plasmas were performed under almost identical conditions. Although many kinds of reactive species such as hydroxyl radicals and excited nitrogen molecules were observed with similar intensity in both plasmas, intensities of nitrogen ion molecules and nitric oxide molecules were extremely strong in the helium plasma. It is considered that nitrogen ion molecules were mainly produced by penning ionization by helium metastable. Near the target, a significant increase in the emissions of reactive species is observed. There is a possibility that electron acceleration was induced in a local electric field formed on the surface. However, in argon plasma, emissions from nitrogen ion were not measured even near the target surface. These differences between the two plasmas may be producing the difference in blood coagulation behaviour. To control the surrounding gas of the plasma, a gas-component-controllable chamber was assembled. Filling the chamber with O 2 /He or N 2 /He gas mixtures selectively produces either reactive oxygen species or reactive nitrogen species. Through selective treatments, this chamber would be useful in studying the effects of specific reactive species on blood coagulation. (paper)

  12. Spectroscopy of reactive species produced by low-energy atmospheric-pressure plasma on conductive target material surface

    Science.gov (United States)

    Yamada, Hiromasa; Sakakita, Hajime; Kato, Susumu; Kim, Jaeho; Kiyama, Satoru; Fujiwara, Masanori; Itagaki, Hirotomo; Okazaki, Toshiya; Ikehara, Sanae; Nakanishi, Hayao; Shimizu, Nobuyuki; Ikehara, Yuzuru

    2016-10-01

    A method for blood coagulation using low-energy atmospheric-pressure plasma (LEAPP) is confirmed as an alternative procedure to reduce tissue damage caused by heat. Blood coagulation using LEAPP behaves differently depending on working gas species; helium is more effective than argon in promoting fast coagulation. To analyse the difference in reactive species produced by helium and argon plasma, spectroscopic measurements were conducted without and with a target material. To compare emissions, blood coagulation experiments using LEAPP for both plasmas were performed under almost identical conditions. Although many kinds of reactive species such as hydroxyl radicals and excited nitrogen molecules were observed with similar intensity in both plasmas, intensities of nitrogen ion molecules and nitric oxide molecules were extremely strong in the helium plasma. It is considered that nitrogen ion molecules were mainly produced by penning ionization by helium metastable. Near the target, a significant increase in the emissions of reactive species is observed. There is a possibility that electron acceleration was induced in a local electric field formed on the surface. However, in argon plasma, emissions from nitrogen ion were not measured even near the target surface. These differences between the two plasmas may be producing the difference in blood coagulation behaviour. To control the surrounding gas of the plasma, a gas-component-controllable chamber was assembled. Filling the chamber with O2/He or N2/He gas mixtures selectively produces either reactive oxygen species or reactive nitrogen species. Through selective treatments, this chamber would be useful in studying the effects of specific reactive species on blood coagulation.

  13. Spectroscopic study of thermal plasma jet generated by a hybrid water-argon stabilized DC arc torch

    Czech Academy of Sciences Publication Activity Database

    Sember, Viktor

    2003-01-01

    Roč. 7, č. 1 (2003), s. 17-22 ISSN 1093-3611 R&D Projects: GA AV ČR KSK2043105; GA ČR GA202/01/1563 Institutional research plan: CEZ:AV0Z2043910 Keywords : plasma jet, spectroscopy, mixing Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 0.116, year: 2003

  14. UPLC-MRM Mass Spectrometry Method for Measurement of the Coagulation Inhibitors Dabigatran and Rivaroxaban in Human Plasma and Its Comparison with Functional Assays.

    Directory of Open Access Journals (Sweden)

    Joachim Kuhn

    Full Text Available The fast, precise, and accurate measurement of the new generation of oral anticoagulants such as dabigatran and rivaroxaban in patients' plasma my provide important information in different clinical circumstances such as in the case of suspicion of overdose, when patients switch from existing oral anticoagulant, in patients with hepatic or renal impairment, by concomitant use of interaction drugs, or to assess anticoagulant concentration in patients' blood before major surgery.Here, we describe a quick and precise method to measure the coagulation inhibitors dabigatran and rivaroxaban using ultra-performance liquid chromatography electrospray ionization-tandem mass spectrometry in multiple reactions monitoring (MRM mode (UPLC-MRM MS. Internal standards (ISs were added to the sample and after protein precipitation; the sample was separated on a reverse phase column. After ionization of the analytes the ions were detected using electrospray ionization-tandem mass spectrometry. Run time was 2.5 minutes per injection. Ion suppression was characterized by means of post-column infusion.The calibration curves of dabigatran and rivaroxaban were linear over the working range between 0.8 and 800 μg/L (r >0.99. Limits of detection (LOD in the plasma matrix were 0.21 μg/L for dabigatran and 0.34 μg/L for rivaroxaban, and lower limits of quantification (LLOQ in the plasma matrix were 0.46 μg/L for dabigatran and 0.54 μg/L for rivaroxaban. The intraassay coefficients of variation (CVs for dabigatran and rivaroxaban were < 4% and 6%; respectively, the interassay CVs were < 6% for dabigatran and < 9% for rivaroxaban. Inaccuracy was < 5% for both substances. The mean recovery was 104.5% (range 83.8-113.0% for dabigatran and 87.0% (range 73.6-105.4% for rivaroxaban. No significant ion suppressions were detected at the elution times of dabigatran or rivaroxaban. Both coagulation inhibitors were stable in citrate plasma at -20°C, 4°C and even at RT for at

  15. Electrical and spectral characteristics of an atmospheric pressure argon plasma jet generated with tube-ring electrodes in surface dielectric barrier discharge

    Energy Technology Data Exchange (ETDEWEB)

    Hong, Y. [Institute of Electrostatics and Special Power, Dalian University of Technology, Dalian 116024 (China); Department of Physics and Electrical Engineering, Weinan Teachers University, Weinan 71400 (China); Lu, N. [Institute of Electrostatics and Special Power, Dalian University of Technology, Dalian 116024 (China); Pan, J. [Department of Physics and Electrical Engineering, Weinan Teachers University, Weinan 71400 (China); Li, J., E-mail: lijie@dlut.edu.cn [Institute of Electrostatics and Special Power, Dalian University of Technology, Dalian 116024 (China); Wu, Y. [Institute of Electrostatics and Special Power, Dalian University of Technology, Dalian 116024 (China)

    2013-03-01

    An atmospheric-pressure argon plasma jet is generated with tube-ring electrodes in surface dielectric barrier discharge by a sinusoidal excitation voltage at 8 kHz. The electrical and spectral characteristics are estimated such as conduction and displacement current, electric-field, electron temperature, rotational temperature of N{sub 2} and OH, electronic excitation temperature, and oxygen atomic density. It is found that the electric-field magnitudes in the top area of the ground electrode are higher than that in the bottom area of the power electrode, and the electron temperature along radial direction is in the range of 9.6–10.4 eV and along axial direction in the range of 4.9–10 eV. The rotational temperature of N{sub 2} obtained by comparing the simulated spectrum with the measured spectrum at the C{sup 3}Π{sub u} → B{sup 3}Π{sub g}(Δv = − 2) band transition is in the range of 342–387 K, the electronic excitation temperature determined by Boltzmann's plot method is in the range of 3188–3295 K, and the oxygen atomic density estimated by the spectral intensity ratio of atomic oxygen line λ = 844.6 nm to argon line λ = 750.4 nm is in the order of magnitude of 10{sup 16} cm{sup −3}, respectively. - Highlights: ► The conduction and displacement current are calculated by equivalent circuit diagram. ► The 2D distribution of electric-field magnitude is calculated by ElecNet software. ► The electron temperature along axial direction is in the range of 4.9–10 eV. ► The oxygen atomic density is about a magnitude of 10{sup 16} cm{sup −3}.

  16. Recovery of tungsten surface with fiber-form nanostructure by the argon plasma irradiation at a high surface temperature

    International Nuclear Information System (INIS)

    Takamura, Shuichi; Miyamoto, Takanori

    2011-01-01

    One of the serious concerns for tungsten materials in fusion devices is the radiation defects caused by helium plasma irradiation, while the helium is one of fusion products. Fiber-formed nanostructure is worried to have a possible weakness against the plasma heat flux and may destroy the reflectivity as an optical mirror. In this communication an interesting method for a recovery of such a tungsten surface is shown. (author)

  17. One- and two-dimensional density and temperature measurements of an argon-neon Z-pinch plasma at stagnation

    International Nuclear Information System (INIS)

    Wong, K.L.; Springer, P.T.; Hammer, J.H.; Iglesias, C.A.; Osterheld, A.L.; Foord, M.E.; Bruns, H.C.; Emig, J.A.; Deeney, C.

    1996-10-01

    In order to benchmark and improve current 2D radiation magnetohydrodynamic (MHD) models of Z-pinch plasmas, we have performed experiments which characterize the plasma -conditions at stagnation. In the experiments the SATURN pulsed power facility at Sandia National Laboratory was used to create an imploding -Ar-Ne plasma. An absolutely calibrated, high resolution space- and time- resolving Johann crystal spectrometer was used to infer the electron temperature Te from the slope of the hydrogenlike Ne free-bound continuum, and the ion density ni from the Stark broadening of the Ar heliunlike Rydberg series. 2D electron temperature profiles of the plasma are obtained from a set of imaging crystals also focused on the Ne free-bound continuum. We shot two types of gas nozzles in the experiment, annular and uniform fill which varies the amount of mass in the plasma. 2D local thermodynamic equilibrium (LTE) and non-LTE MM models predict a radiating region denser and cooler than measured

  18. One- and two-dimensional density and temperature measurements of an argon-neon Z-pinch plasma at stagnation

    International Nuclear Information System (INIS)

    Wong, K.L.; Springer, P.T.; Hammer, J.H.; Iglesias, C.A.; Osterheld, A.L.; Foord, M.E.; Bruns, H.C.; Emig, J.A.; Deeney, C.

    1997-01-01

    In order to benchmark and improve current 2D radiation magnetohydrodynamic (MHD) models of Z-pinch plasmas, we have performed experiments which characterize the plasma conditions at stagnation. In the experiments the SATURN pulsed power facility at Sandia National Laboratory was used to create an imploding Ar-Ne plasma. An absolutely calibrated, high resolution space- and time-resolving Johann crystal spectrometer was used to infer the electron temperature T e from the slope of the hydrogenlike Ne free-bound continuum, and the ion density n i from the Stark broadening of the Ar heliumlike Rydberg series. 2D electron temperature profiles of the plasma are obtained from a set of imaging crystals also focused on the Ne free-bound continuum. We shot two types of gas nozzles in the experiment, annular and uniform fill, which varies the amount of mass in the plasma. 2D local thermodynamic equilibrium (LTE) and non-LTE MHD models predict a radiating region denser and cooler than measured. copyright 1997 American Institute of Physics

  19. Effect of radiation and non-Maxwellian electron distribution on relaxation processes in an atmospheric cesium seeded argon plasma

    International Nuclear Information System (INIS)

    Borghi, C.A.; Veefkind, A.; Wetzer, J.M.

    1982-03-01

    A model, describing the time dependent behaviour of a noble gas MHD generator plasma, has been set up. With this model it is possible to calculate the relaxation for ionization or recombination as a response to a stepwise temperature development, once the initial and final conditions are given. In model radiative transitions and a deviation from Maxwellian electron distribution are included. Radiation causes an enhancement of both the ionization relaxation time and the recombination relaxation time. A non-Maxwellian electron distribution results in an increase of the relaxation time for an ionizing plasma because of an underpopulation of the high energy electrons. A decrease of the relaxation time for a recombining plasma is caused by an overpopulation of high energy electrons. The relaxation time is strongly dependent on the seed ratio and the temperature step. (Auth.)

  20. A differentially pumped argon plasma in the linear plasma generator Magnum-PSI: gas flow and dynamics of the ionized fraction

    NARCIS (Netherlands)

    van Eck, H.J.N.; Hansen, T.A.R.; Kleyn, A.W.; van der Meiden, H.J.; Schram, D.C.; Zeijlmans van Emmichoven, P.A.

    2011-01-01

    Magnum-PSI is a linear plasma generator designed to reach the plasma-surface interaction (PSI) regime of ITER and nuclear fusion reactors beyond ITER. To reach this regime, the influx of cold neutrals from the source must be significantly lower than the plasma flux reaching the target. This is

  1. Influences of ABO blood group, age and gender on plasma coagulation factor VIII, fibrinogen, von Willebrand factor and ADAMTS13 levels in a Chinese population.

    Science.gov (United States)

    Wang, Zongkui; Dou, Miaomiao; Du, Xi; Ma, Li; Sun, Pan; Cao, Haijun; Ye, Shengliang; Jiang, Peng; Liu, Fengjuan; Lin, Fangzhao; Zhang, Rong; Li, Changqing

    2017-01-01

    ABO blood group is a hereditary factor of plasma levels of coagulation factor VIII (FVIII) and von Willebrand factor (VWF). Age and gender have been shown to influence FVIII, VWF, fibrinogen (Fbg), and ADAMTS13 (A disintegrin and metalloprotease with thrombospondin type 1 motif, 13). We investigated the effects of ABO type, age, and gender on plasma levels of FVIII, Fbg, VWF, and ADAMTS13 in a Chinese population. A total of 290 healthy volunteers were eligible for this study. ABO blood group was determined by indirect technique. FVIII:C and Fbg were measured by clotting assays. VWF antigen (VWF:Ag), collagen-binding activity (VWF:CBA), and ADAMTS13 antigen were assessed by ELISA, whereas VWF ristocetin cofactor activity (VWF:Rcof) was performed by agglutination of platelets with ristocetin. Mean FVIII:C and VWF levels (VWF:Ag, VWF:CBA, and VWF:Rcof) were significantly higher in non-O than in O type subjects ( p  blood group, age, and gender showed different effects on plasma levels of FVIII:C, Fbg, VWF:Ag, VWF:CBA, VWF:Rcof, and ADAMTS13 antigen. These new data on a Chinese population are quite helpful to compare with other ethnic groups.

  2. Argon-plasma-controlled optical reset in the SiO2/Cu filamentary resistive memory stack

    Science.gov (United States)

    Kawashima, T.; Yew, K. S.; Zhou, Y.; Ang, D. S.; Zhang, H. Z.; Kyuno, K.

    2018-05-01

    We show that resistive switching in the SiO2/Cu stack can be modified by a brief exposure of the oxide to an Ar plasma. The set voltage of the SiO2/Cu stack is reduced by 33%, while the breakdown voltage of the SiO2/Si stack (control) is almost unchanged. Besides, the Ar plasma treatment suppresses the negative photoconductivity or optical resistance reset effect, where the electrically formed filamentary conductive path consisting of Cu-ion and oxygen-vacancy clusters is disrupted by the recombination of the oxygen vacancies with nearby light-excited oxygen ions. From the enhanced O-H peak in the Fourier-transform infrared spectrum of the plasma-treated oxide, it is proposed that the Ar plasma has created more oxygen vacancies in the surface region of the oxide. These vacancies in turn adsorb water molecules, which act as counter anions (OH-) promoting the migration of Cu cations into the oxide and forming a more complete Cu filament that is less responsive to light. The finding points to the prospect of a control over the optical resistance reset effect by a simple surface treatment step.

  3. Temporally resolved ozone distribution of a time modulated RF atmospheric pressure argon plasma jet: flow, chemical reaction, and transient vortex

    International Nuclear Information System (INIS)

    Zhang, S; Sobota, A; Van Veldhuizen, E M; Bruggeman, P J

    2015-01-01

    The ozone density distribution in the effluent of a time modulated RF atmospheric pressure plasma jet (APPJ) is investigated by time and spatially resolved by UV absorption spectroscopy. The plasma jet is operated with an averaged dissipated power of 6.5 W and gas flow rate 2 slm argon  +2% O 2 . The modulation frequency of the RF power is 50 Hz with a duty cycle of 50%. To investigate the production and destruction mechanism of ozone in the plasma effluent, the atomic oxygen and gas temperature is also obtained by TALIF and Rayleigh scattering, respectively. A temporal increase in ozone density is observed close to the quartz tube exit when the plasma is switched off due to the decrease in O density and gas temperature. Ozone absorption at different axial positions indicates that the ozone distribution is dominated by the convection induced by the gas flow and allows estimating the on-axis local gas velocity in the jet effluent. Transient vortex structures occurring during the switch on and off of the RF power also significantly affect the ozone density in the far effluent. (paper)

  4. 2D collisional-radiative model for non-uniform argon plasmas: with or without ‘escape factor’

    International Nuclear Information System (INIS)

    Zhu, Xi-Ming; Tsankov, Tsanko Vaskov; Luggenhölscher, Dirk; Czarnetzki, Uwe

    2015-01-01

    Collisional-radiative models for excited rare-gas atoms in low-temperature plasmas are a widely investigated topic. When these plasmas are optically thick, an ‘escape factor’ is introduced into the models to account for the reabsorption of photons (so-called radiation trapping process). This factor is usually obtained assuming a uniform density profile of the excited species; however, such an assumption is often not satisfied in a bounded plasma. This article reports for the first time a self-consistent collisional-radiative model without using an ad hoc ‘escape factor’ for excited Ar atoms in the 2p states (in Paschen’s notation). Rather, the rate balance equations—i.e. the radiation transfer equations—of the 2p states are numerically solved to yield the actual density profiles. The predictions of this self-consistent model and a model based on the escape factor concept are compared with spatially-resolved emission measurements in a low-pressure inductive Ar plasma. The self-consistent model agrees well with the experiment but the ‘escape factor’ model shows considerable deviations. By the comparative analysis the limitations and shortcomings of the escape factor concept as adopted in a significant number of works are revealed. (paper)

  5. Atomic hydrogen and argon ground state density determination in a recombining plasma using visible light absorption spectroscopy

    NARCIS (Netherlands)

    Otorbaev, D.K.; Buuron, A.J.M.; Sanden, van de M.C.M.; Meulenbroeks, R.F.G.; Schram, D.C.

    1995-01-01

    The atomic radical density in the first excited state, obtained by the technique of optical absorption spectroscopy, and a simple kinetic model are used to determine the radical ground state density in a recombining expanding plasma. The kinetic model used does not require knowledge of the shape of

  6. Influence of matrices on electron temperature of laser micro-plasma in argon atmosphere at reduced pressure

    International Nuclear Information System (INIS)

    Guo Qinlin; Zhou Yulong; Zhang Bo; Zhang Qiulin; Zhang Jinping; Huai Sufang

    2007-01-01

    Laser micro-spectral analysis coupled with CCD spectrometer was used in this experiment. With Fe I 356.54 nm and Fe I 358.12 nm as analysis spectral lines, the micro-plasma temperature and its spatial distribution were investigated in different matrices, namely Mg, Al, Si, and steel alloy6-0. The electron temperature as a function of location in each matrix and the differences of that at the same location in different matrices were determined and an explanation was given. Finally, with Cu I 324.75 nm and Zn I 394.50 nm as analysis spectral lines, we have successfully used the calculated micro-plasma temperature to discuss the matrix effect. (authors)

  7. Irradiation influence on Mylar and Makrofol induced by argon ions in a plasma immersion ion implantation system

    Energy Technology Data Exchange (ETDEWEB)

    Hassan, A. [Accelerators & Ion Sources Department, Nuclear Research Center, Atomic Energy Authority, P.O. 13759, Cairo (Egypt); El-Saftawy, A.A., E-mail: aama1978@yahoo.com [Accelerators & Ion Sources Department, Nuclear Research Center, Atomic Energy Authority, P.O. 13759, Cairo (Egypt); Aal, S.A. Abd El [Central Lab. for Elemental & Isotopic Analysis, Nuclear Research Center, Atomic Energy Authority, P.O. 13759, Cairo (Egypt); Ghazaly, M. El [Physiology Department, College of Medicine, Taif University, P.O. 888, Taif (Saudi Arabia); Physics Department, Faculty of Science, Zagazig University, P.O. 44519, Zagazig (Egypt)

    2015-08-30

    Highlights: • A home-built plasma immersion ion implantation system was tested in modifying surfaces. • Wettability modifications within the energy range 10 keV implantation are not investigated elsewhere, up to our knowledge. • The wettability of Mylar and Makrofol surface was enhanced by the dual effect of ion implantation and plasma treatment. • The improved wettability was found to depend on both surface roughness and chemistry. • The adhesive bonding and surface energy of the polymers are improved. - Abstract: Mylar and Makrofol polycarbonate polymers were irradiated by Ar ions in a plasma immersion ion implantation (PIII) system. The surface wettability of both polymers was investigated by employing the contact angle method. The measured contact angles were found to depend on the surface layer properties. Good wetting surfaces were found to depend not only on surface roughness but also on its chemistry that analyzed by Fourier transform infrared (FTIR) spectroscopy. Surfaces topography and roughness was investigated and correlated to their surface energy which studied with the aid of acid-base model for evaluating the improvement of surface wettability after irradiation. PIII improves polymers surface properties efficiently in a controllable way.

  8. A study of the interference of cesium and phosphate in the low power inductively coupled radiofrequency argon plasma using spatially resolved emission and absorption measurements, ch. 4

    International Nuclear Information System (INIS)

    Kornblum, G.R.

    1977-01-01

    The literature on interferences in the radio frequency inductively coupled atmospheric argon plasma (ICP) is reviewed. Even for the most extensively investigated interferences of aluminum, phosphate and alkali elements on calcium, the studies are mostly descriptive. Inter-pretation of these data is impeded by conflicting results, the absence of thermal equilibrium and the lack of radially resolved observations. The present study of a low-power ICP $ KW) utilizes the Abel inversion technique for emission and absorption measurements of atom and ion lines to clarify the mechanism of interferences on calcium and magnesium due to phosphate and cesium. Under conditions of large carrier gas flow (4.5 l/min) the pronounced interferences are the result of three combined effects: volatilization interference, a change in excitation temperature and a shift in the ionization equilibrium. At lower carrier gas flow (1.4 l/min) the interferences are markedly reduced but still due to the same three effects. The relative preponderance of a particular type of interference depends upon the height of observation and upon the particular combination of analyte and interferent considered

  9. Enhanced ozone production in a pulsed dielectric barrier discharge plasma jet with addition of argon to a He-O2 flow gas

    Science.gov (United States)

    Sands, Brian; Ganguly, Biswa; Scofield, James

    2013-09-01

    Ozone production in a plasma jet DBD driven with a 20-ns risetime unipolar pulsed voltage can be significantly enhanced using helium as the primary flow gas with an O2 coflow. The overvolted discharge can be sustained with up to a 5% O2 coflow at pulse repetition frequency at 13 kV applied voltage. Ozone production scales with the pulse repetition frequency up to a ``turnover frequency'' that depends on the O2 concentration, total gas flow rate, and applied voltage. For example, peak ozone densities >1016 cm-3 were measured with 3% O2 admixture and discharge current and 777 nm O(5 P) emission, but decreased ozone production and is followed by a transition to a filamentary discharge mode. The addition of argon at concentrations >=5% reduces the channel conductivity and shifts the turnover frequency to higher frequencies. This results in increased ozone production for a given applied voltage and gas flow rate. Time-resolved Ar(1s5) and He(23S1) metastable densities were acquired along with discharge current and ozone density measurements to gain insight into the mechanisms of optimum ozone production.

  10. Preliminary Study of Mixing of Plasma Species in a Hybrid-Stabilized Argon-Water Electric Arc

    Czech Academy of Sciences Publication Activity Database

    Jeništa, Jiří; Takana, H.; Uehara, S.; Nishiyama, H.; Murphy, A.B.; Bartlová, M.; Aubrecht, V.

    2015-01-01

    Roč. 2, č. 3 (2015), s. 316-319 ISSN 2336-2626. [Symposium on Physics of Switching Arc/21./. Nové Město na Moravě, 07.09.2015-11.09.2015] R&D Project s: GA ČR(CZ) GA15-19444S Institutional support: RVO:61389021 Keywords : arc discharge * combined diffusion coefficients * inhomogeneous mixing * mass fraction Subject RIV: BL - Plasma and Gas Discharge Physics https://www.vutbr.cz/www_base/vutdisk.php?i=36809a9aa

  11. A differentially pumped argon plasma in the linear plasma generator Magnum-PSI: gas flow and dynamics of the ionized fraction

    NARCIS (Netherlands)

    Eck, van H.J.N.; Hansen, T.A.R.; Kleyn, A.W.; Meiden, van der H.J.; Schram, D.C.; Zeijlmans van Emmichoven, P.A.

    2011-01-01

    Magnum-PSI is a linear plasma generator designed to reach the plasma–surface interaction (PSI) regime of ITER and nuclear fusion reactors beyond ITER. To reach this regime, the influx of cold neutrals from the source must be significantly lower than the plasma flux reaching the target. This is

  12. EPR-Spin Trapping and Flow Cytometric Studies of Free Radicals Generated Using Cold Atmospheric Argon Plasma and X-Ray Irradiation in Aqueous Solutions and Intracellular Milieu.

    Directory of Open Access Journals (Sweden)

    Hidefumi Uchiyama

    Full Text Available Electron paramagnetic resonance (EPR-spin trapping and flow cytometry were used to identify free radicals generated using argon-cold atmospheric plasma (Ar-CAP in aqueous solutions and intracellularly in comparison with those generated by X-irradiation. Ar-CAP was generated using a high-voltage power supply unit with low-frequency excitation. The characteristics of Ar-CAP were estimated by vacuum UV absorption and emission spectra measurements. Hydroxyl (·OH radicals and hydrogen (H atoms in aqueous solutions were identified with the spin traps 5,5-dimethyl-1-pyrroline N-oxide (DMPO, 3,3,5,5-tetramethyl-1-pyrroline-N-oxide (M4PO, and phenyl N-t-butylnitrone (PBN. The occurrence of Ar-CAP-induced pyrolysis was evaluated using the spin trap 3,5-dibromo-4-nitrosobenzene sulfonate (DBNBS in aqueous solutions of DNA constituents, sodium acetate, and L-alanine. Human lymphoma U937 cells were used to study intracellular oxidative stress using five fluorescent probes with different affinities to a number of reactive species. The analysis and quantification of EPR spectra revealed the formation of enormous amounts of ·OH radicals using Ar-CAP compared with that by X-irradiation. Very small amounts of H atoms were detected whereas nitric oxide was not found. The formation of ·OH radicals depended on the type of rare gas used and the yield correlated inversely with ionization energy in the order of krypton > argon = neon > helium. No pyrolysis radicals were detected in aqueous solutions exposed to Ar-CAP. Intracellularly, ·OH, H2O2, which is the recombination product of ·OH, and OCl- were the most likely formed reactive oxygen species after exposure to Ar-CAP. Intracellularly, there was no practical evidence for the formation of NO whereas very small amounts of superoxides were formed. Despite the superiority of Ar-CAP in forming ·OH radicals, the exposure to X-rays proved more lethal. The mechanism of free radical formation in aqueous solutions and

  13. Experimental control of the solvent load of inductively coupled argon plasmas and effects of the chloroform plasma load on their analytical performance

    Science.gov (United States)

    Maessen, F. J. M. J.; Kreuning, G.; Balke, J.

    The solvent plasma load ( QSPL) of water, methanol and chloroform was established as a function of the liquid uptake rate ( QL) by using a continuous weighing method for recording the rate differences between the relevant liquid streams. The shape of the QL vs QSPL curves revealed that the liquid uptake rate is a parameter much too insensitive to serve as a criterion for assessing the stability of "organic" plasmas. The quantity "maximum tolerable solvent plasma load" is suggested as a more useful criterion. Effects of rf power, observation height and solvent plasma load on the properties of chloroform inductively coupled plasmas (ICPs) are reported. The measurement of the axial distribution of net line intensities of representative spectral lines showed that the behaviour of emission lines as to their "hardness" is essentially the same in ICPs loaded with chloroform or water. The chloroform plasma load was regulated by the use of a condenser of which the temperature was varied in a range between -50°C and +20°C. Analytical performance characteristics such as net line and background intensities, signal-to-background ratios, and relative standard deviations of the background signal are presented for ICPs with various chloroform loads. Two sets of experimental conditions were finally selected for simultaneous multielement analysis of chloroform solvent solutions, one with and one without aerosol cooling. In the case that aerosol cooling was applied, the detection limits were similar to those for aqueous plasmas. Without aerosol cooling the detection limits were up to an order of magnitude poorer. An attempt has been made to catagorize organic solvents on the basis of both volatility and their behaviour in ICP systems. For a better understanding of the consequences of solvent volatility in ICP-AES it is of importance to consider separately the properties that determine the volatility of liquids, viz. the evaporation rate and the saturation vapour pressure.

  14. Postprandial triglycerides and blood coagulation.

    Science.gov (United States)

    Silveira, A

    2001-01-01

    Most of our lifetime we spend in the postprandial state. Postprandial triglyceridemia may represent a procoagulant state involving disturbances of both blood coagulation and fibrinolysis, in particular due to elevation of the plasma levels of activated factor VII (VIIa) and plasminogen activator inhibitor (PAI-1). Therefore, disturbances of the hemostatic system might, at least partly, account for by the link between hypertriglyceridemia and coronary heart disease (CHD). Factor VIIa is the first enzyme of the blood coagulation system and serves a priming function for triggering of the clotting cascade. The coagulant activity of factor VII (VIIc, total activity of factor VII in plasma) was identified as an independent predictor of myocardial infarction in initially healthy middle-aged men, and particularly of fatal coronary events, and both serum cholesterol and triglyceride concentrations correlated positively with the VIIc level. Addition of fat to diet has been consistently shown to cause a rapid conversion of the factor VII zymogen into its active form (VIIa) whereas the concentration of total protein is unaffected. Postprandial activation of factor VII is dependent on lipolytic activity and it is mainly supported by large triglyceride-rich lipoprotein of the VLDL class. Studies in vivo with specific coagulation factor-deficient patients indicate that factor IX is essential for the postprandial activation of factor VII. The basal generation of thrombin seems to be unaffected by increased plasma levels of VIIa. However, since VIIa-tissue factor complex is responsible for the initiation of the coagulation cascade, increased generation of VIIa in the postprandial state would increase the potential for thrombin production in the event of plaque rupture. Plasminogen activator inhibitor-1 (PAI-1) is the major physiological inhibitor of the plasminogen activators in the circulation and thereby the principal inhibitor of the fibrinolytic system. Postprandial

  15. Speciation of arsenic in human nail and hair from arsenic-affected area by HPLC-inductively coupled argon plasma mass spectrometry

    International Nuclear Information System (INIS)

    Mandal, Badal Kumar; Ogra, Yasumitsu; Suzuki, Kazuo T.

    2003-01-01

    Nail and hair are rich in fibrous proteins, i.e., α-keratins that contain abundant cysteine residues (up to 22% in nail and 10-14% in hair). Although they are metabolically dead materials in the epidermis, the roots are highly influenced by the health status of the living beings and their analyses are used as a tool to monitor occupational and environmental exposure to toxic elements. The aims of the present study are to speciate arsenicals in human nail and hair and also to judge whether they should be used as a biomarker to arsenic (As) exposure and/or toxicity. All human fingernail and hair samples (n = 47) were collected from the As-affected area of West Bengal, India. Speciation of arsenicals in water extracts of fingernails and hair at 90 degree sign C was carried out by HPLC-inductively coupled argon plasma mass spectrometer (ICP MS). Fingernails contained iAs III (58.6%), iAs V (21.5), MMA V (7.7), DMA III (9.2), and DMA V (3.0), and hair contained iAs III (60.9%), iAs V (33.2), MMA V (2.2), and DMA V (3.6). Fingernails contained DMA III , but hair did not. The higher percentage of iAs III both in fingernails and hair than that of iAs V suggests more affinity of iAs III to keratin. Although all arsenicals in fingernails and hair correlate to As exposure positively, As speciation in fingernails seems to be more correlated with arsenism than that in hair. Exogenous contamination is a confounding factor for hair to consider it as a biomarker, whereas this is mostly absent in fingernails, which recommends it to be a better biomarker to arsenic exposure. DMA III content in fingernails and DMA V contents in both fingernails and hair could be the biomarker to As exposure

  16. Spectroscopic characterization of low power argon microwave-induced plasma with gaseous species produced from ethanol-water solutions in continuous hydride generation process

    Energy Technology Data Exchange (ETDEWEB)

    Wlodarczyk, Magdalena; Zyrnicki, Wieslaw E-mail: zyrnicki@ichn.ch.pwr.wroc.pl

    2003-03-31

    Low power microwave-induced argon plasma generated by resonant TE{sub 101} rectangular cavity was investigated upon introduction of volatile species formed in the reaction with sodium tetraborohydrate(III) in hydrochloric acid-ethanol solution. The molecular emission bands of OH and CH were used for rotational temperature (T{sub rot}) determination, while the atomic emission lines of Ar, H and Sb were applied for excitation temperature (T{sub exc}) measurement. Assuming a Boltzmann distribution, the temperatures were calculated with the aid of the least squares method. Electron number density (n{sub e}) derived from Stark broadening of the H{sub {beta}} line was found to be between 2.5x10{sup 15} and 0.57x10{sup 15} cm{sup -3}. The detection limits (DL) were determined for Hg and Sb. The influence of ethanol concentration in analyte solution and microwave power on measured parameters, was investigated. The results showed that T{sub rot}(OH) increased from 2970 to 3820 K while T{sub rot}(CH) decreased from 6100 to 4540 K with ethanol concentration in the solution, ranging from 10 to 90%. Under the same experimental conditions the excitation temperature for Ar, H and Sb varied in the following ranges: 5670-4800, 6190-3950 and 10500-7390 K, respectively. It was observed that element DL were significantly influenced by the presence of ethanol in the sample solution. The DL values for Hg and Sb were, as follows: 0.5-11 and 5.3-35 {mu}g l{sup -1}, respectively.

  17. Non-monotonic behavior of electron temperature in argon inductively coupled plasma and its analysis via novel electron mean energy equation

    Science.gov (United States)

    Zhao, Shu-Xia

    2018-03-01

    In this work, the behavior of electron temperature against the power in argon inductively coupled plasma is investigated by a fluid model. The model properly reproduces the non-monotonic variation of temperature with power observed in experiments. By means of a novel electron mean energy equation proposed for the first time in this article, this electron temperature behavior is interpreted. In the overall considered power range, the skin effect of radio frequency electric field results in localized deposited power density, responsible for an increase of electron temperature with power by means of one parameter defined as power density divided by electron density. At low powers, the rate fraction of multistep and Penning ionizations of metastables that consume electron energy two times significantly increases with power, which dominates over the skin effect and consequently leads to the decrease of temperature with power. In the middle power regime, a transition region of temperature is given by the competition between the ionizing effect of metastables and the skin effect of electric field. The power location where the temperature alters its trend moves to the low power end as increasing the pressure due to the lack of metastables. The non-monotonic curve of temperature is asymmetric at the short chamber due to the weak role of skin effect in increasing the temperature and tends symmetric when axially prolonging the chamber. Still, the validity of the fluid model in this prediction is estimated and the role of neutral gas heating is guessed. This finding is helpful for people understanding the different trends of temperature with power in the literature.

  18. The genetic variation rs6903956 in the novel androgen-dependent tissue factor pathway inhibitor regulating protein (ADTRP) gene is not associated with levels of plasma coagulation factors in the Singaporean Chinese

    OpenAIRE

    Chang, Xuling; Chin, Hui-Lin; Quek, Swee-Chye; Goh, Daniel Y. T.; Dorajoo, Rajkumar; Friedlander, Yechiel; Heng, Chew-Kiat

    2017-01-01

    Background Genome-wide association study (GWAS) has reported that rs6903956 within the first intron of androgen-dependent tissue factor pathway inhibitor (TFPI) regulating protein (ADTRP) gene is associated with coronary artery disease (CAD) risk in the Chinese population. Although ADTRP is believed to be involved in the upregulation of TFPI, the underlying mechanism involved is largely unknown. This study investigated the association of rs6903956 with plasma Factor VII coagulant activity (FV...

  19. External quality assurance of fibrinogen assays using normal plasma: results of the 2008 College of American Pathologists proficiency testing program in coagulation.

    Science.gov (United States)

    Cunningham, Mark T; Olson, John D; Chandler, Wayne L; Van Cott, Elizabeth M; Eby, Charles S; Teruya, Jun; Hollensead, Sandra C; Adcock, Dorothy M; Allison, Paul M; Kottke-Marchant, Kandice K; Smith, Marc D

    2012-07-01

    Proper diagnosis and therapy of fibrinogen deficiency requires high-quality fibrinogen assays. To assess the interlaboratory bias, precision, and grading of fibrinogen assays used by laboratories participating in the United States College of American Pathologists proficiency testing program in coagulation. Two identical vials of normal plasma were sent to more than 3500 laboratories. Participants measured fibrinogen levels using local methods. Fifty different fibrinogen methods were evaluated. All-method bias was 8.3% (range of method-specific biases, 0.0%-27.0%) and all-method coefficient of variation was 7.7% (range of method-specific coefficients of variation, 0.7%-25.8%). After controlling for reagent/instrument type, mean fibrinogen levels were 11.6% higher for prothrombin time-based reagents compared to Clauss (P graded as pass or fail using a target range of ±20% from the method mean (total pass rate, 98.8%). Total fail rate was 3.0-fold lower for mechanical instruments compared to photo-optical (0.5% versus 1.5%, P  =  .001). Nonetheless many photo-optical methods had very high precision and very low fail rates. Fibrinogen assays showed highly variable methodology and performance characteristics. Bias, precision, and grading were affected by the type of reagent or instrument used.

  20. High-resolution VUV spectra of carbon, neon and argon in a wavelength range of 250 to 2300 A for plasma diagnostics observed with a 3 m normal incidence spectrometer in LHD

    International Nuclear Information System (INIS)

    Katai, Ryuji; Morita, Shigeru; Goto, Motoshi

    2007-01-01

    Intrinsic impurities have been much reduced in toroidal fusion devices through the development of several wall-conditioning techniques as well as by the use of carbon materials in the first wall and divertor plates. Impurity elements useful for passive plasma spectroscopy have been then extremely limited. At present, only carbon is a subject for spectroscopic diagnostics in most discharges except for fuel atoms. The use of rare gas as a brighter light source is a method to overcome the present difficulty in passive spectroscopy. Recently, rare gases have also been used for edge cooling to reduce the divertor heat flux. Therefore, high-resolution spectra (Δλ - 0.2 A) from neon and argon in a 250 to 2300 A wavelength range have been measured using a 3 m normal incidence spectrometer in Large Helical Device (LHD) and the measured spectra were precisely analyzed. The VUV spectra of carbon, neon and argon are presented for spectroscopic use and their wavelengths are tabulated with their relative intensities. The spectral profiles of almost all the spectral lines measured here are formed by the Doppler broadening and self-absorption processes. The Doppler broadening of neon and argon spectra are plotted against the ionization energies and Doppler spectra from carbon lines are presented. The self-absorption spectra of the hydrogen Lyman-α line, which are found in the LHD high-density discharge, are also presented and the neutral density is analytically estimated. (author)

  1. Argon/UF6 plasma exhaust gas reconstitution experiments using preheated fluorine and on-line diagnostics. [fissioning uranium plasma core reactor design

    Science.gov (United States)

    Roman, W. C.

    1979-01-01

    The feasibility of employing a flowing, high-temperature, pure fluorine/UF6 regeneration system to efficiently convert a large fraction of the effluent plasma exhaust back to pure UF6 was demonstrated. The custom built T.O.F. mass spectrometer sampling system permitted on-line measurements of the UF6 concentration at different locations in the exhaust system. Negligible amounts ( 100 ppm) of UF6 were detected in the axial bypass exhaust duct and the exhaust ducts downstream of the cryogenic trap system used to collect the UF6, thus verifying the overall system efficiency over a range of operating conditions. Use of a porous Monel duct as part of the exhaust duct system, including provision for injection of pure fluorine, provided a viable technique to eliminate uranium compound residue on the inside surface of the exhaust ducts. Typical uranium compound mass deposition per unit area of duct was 2 micron g/sq cm. This porous duct technique is directly applicable to future uranium compound transfer exhaust systems. Throughout these experiments, additional basic data on the corrosion aspects of hot, pressurized UF6/fluorine were also accumulated.

  2. Thermal conductivity in an argon arc at atmospheric pressure

    NARCIS (Netherlands)

    Bol, L.; Timmermans, C.J.; Schram, D.C.

    1984-01-01

    The thermal conductivity of an argon plasma has been determined in a phi 5 mm wall stabilized atmospheric argon arc in the temperature range from 10000 to 16000 K. The calculations are based on the energy balance, and include non-LTE effects like ambipolar diffusion and overpopulation of the ground

  3. Argon-ion contamination of the plasmasphere

    International Nuclear Information System (INIS)

    Chiu, Y.T.; Cornwall, J.M.; Luhmann, J.G.; Schulz, M.

    1979-01-01

    This paper applies present observational and analytic knowledge on effects of plasma beam interaction wth the magnetosphere to the plasmasphere contamination problem of the argon ion engine exhaust expected to be deposited in the magnetosphere during the construction phase of the Satellite Power System. Effects of plasmasphere, ionosphere, and radiation belt modifications are discussed

  4. Argon analytical procedures for potassium-argon dating

    International Nuclear Information System (INIS)

    Gabites, J.E.; Adams, C.J.

    1981-01-01

    A manual for the argon analytical methods involved in potassium-argon geochronology, including: i) operating procedures for the ultra-high vacuum argon extraction/purification equipment for the analysis of nanolitre quantities of radiogenic argon in rocks, minerals and gases; ii) operating procedures for the AEI-MS10 gas source mass spectrometer

  5. Potassium-argon technology

    International Nuclear Information System (INIS)

    Cassignol, Charles; Cornette, Yves; David, Benjamin; Gillot, P.-Y.

    1978-04-01

    The main features of the method of processing rocks and minerals and measuring the extracted argon, for the purpose of potassium-argon dating are described. It differs in several respects from the conventional one, as described, f.i., in Dalrymple and Lanphere's monography. Principally it was established that the continual purification of the gases in the mass spectrometer cell during the measurement, stops the peaks of current drift, and renders them representative of the introduced argon. This allows on the one hand to improve the reliability and accuracy of measurements, on the other hand to get rid of the isotopic dilution method, with 38 A as a spike. Moreover the reliability of the radiogenic argon is improved by taking into account the mislinearness of the M.S. response. All this results in a higher performance of the K/Ar dating method, especially in the recent ages range. The technological side of the problem was only dealt with [fr

  6. Using the van der Waals broadening of the spectral atomic lines to measure the gas temperature of an argon microwave plasma at atmospheric pressure

    International Nuclear Information System (INIS)

    Yubero, C.; Dimitrijevic, M.S.; Garcia, M.C.; Calzada, M.D.

    2007-01-01

    The ro-vibrational emission spectra of the molecular species are usually used to measure the gas temperature of a discharge at atmospheric pressure. However, under some experimental conditions, it is difficult to detect them. In order to overcome this difficulty and obtain the temperature, there are methods based on the relation between the gas temperature and the van der Waals broadening of argon atomic spectral lines with a Stark contribution negligible. In this work, we propose a method based on this relation but for lines with a Stark broadening comparable with the van der Waals one

  7. Phenomenological modeling of argon Z-pinch implosions

    International Nuclear Information System (INIS)

    Whitney, K.G.; Thornhill, J.W.; Deeney, C.; LePell, P.D.; Coulter, M.C.

    1992-01-01

    The authors investigate some of the effects of plasma turbulence on the K-shell emission dynamics of argon gas puff Z-pinch implosions. The increases that turbulence produces in the plasma viscosity, heat conductivity, and electrical resistivity are modeled phenomenologically using multipliers for these quantities in the MHD calculations. The choice of multipliers was made by benchmarking a 1-D MHD simulation of a Physics International Inc. argon gas puff experiment against the inferred densities and temperatures achieved in the experiment. These multipliers were then used to study the parametric dependence of the K-shell emission on the energy input to the argon plasma for a fixed mass loading. Comparisons between turbulent and non-turbulent argon implosions are made

  8. Is it acceptable to use coagulation plasma samples stored at room temperature and 4°C for 24 hours for additional prothrombin time, activated partial thromboplastin time, fibrinogen, antithrombin, and D-dimer testing?

    Science.gov (United States)

    Rimac, V; Coen Herak, D

    2017-10-01

    Coagulation laboratories are faced on daily basis with requests for additional testing in already analyzed fresh plasma samples. This prompted us to examine whether plasma samples stored at room temperature (RT), and 4°C for 24 hours can be accepted for additional prothrombin time (PT), activated partial thromboplastin time (aPTT), fibrinogen (Fbg), antithrombin (AT), and D-dimer testing. We measured PT, aPTT, Fbg in 50 and AT in 30 plasma samples with normal and pathological values, within 4 hours of blood collection (baseline results) and after 24-hours storage at RT (primary tubes), and 4°C (aliquots). D-dimer stability was investigated in 20 samples stored in primary tubes at 4°C. No statistically significant difference between baseline results and results in samples stored at RT and 4°C was observed for PT (P=.938), aPTT (P=.186), Fbg (P=.962), AT (P=.713), and D-dimers (P=.169). The highest median percentage changes were found for aPTT, being more pronounced for samples stored at 4°C (13.0%) than at RT (8.7%). Plasma samples stored both at RT and 4°C for 24 hours are acceptable for additional PT, Fbg, and AT testing. Plasma samples stored 24 hours in primary tubes at 4°C are suitable for D-dimer testing. © 2017 John Wiley & Sons Ltd.

  9. SLD liquid argon calorimeter

    International Nuclear Information System (INIS)

    Vella, E.

    1992-10-01

    The liquid argon calorimeter (LAC) of the SLD detector is a parallel plate -- liquid argon sampling calorimeter, used to measure particle energies in Z 0 decays at the Stanford Linear Collider. The LAC module design is based on a unique projective tower structure, in which lead plates and segmented lead tiles serve both as absorbers and electrodes. The LAC front end electronics incorporates several novel features, including extensive multiplexing and optical fiber readout, which take advantage of the low SLC beam crossing frequency. The operational performance of the LAC during the recently completed SLD physics run (which recorded over 10,000 Z 0 events) is discussed

  10. Departure from Local Thermodynamic Equilibrium in argon plasmas sustained in a Torche à Injection Axiale sur Guide d'Ondes

    International Nuclear Information System (INIS)

    Rincón, R.; Muñoz, J.; Calzada, M.D.

    2015-01-01

    Plasma torches are suitable plasma sources for a wide range of applications. The capability of these discharges to produce processes like sample excitation or decomposition of molecules inside them depends on the density of the plasma species and their energies (temperatures). The relation between these parameters determines the specific state of thermodynamic equilibrium in the discharge. Thus, the understanding of plasma possibilities for application purposes is related to the knowledge of the plasma thermodynamic equilibrium degree. In this paper a discussion about the equilibrium state for Ar plasmas generated by using a Torche à Injection Axiale sur Guide d'Ondes, TIAGO device, is presented. Emission spectroscopy techniques were used to measure gas temperature and electron density at the exit of the nozzle torch and along the dart. Boltzmann-plots as well as b p parameters were calculated to characterize the type and degree of departure from partial Local Saha Equilibrium (pLSE). This study indicates that the closer situation to Local Thermodynamic Equilibrium (LTE) of the plasma corresponds to larger Ar flows which highlights the importance of the nitrogen (atmosphere surrounding the plasma) in the kinetics of Ar-TIAGO discharges. - Highlights: • Discharges sustained in Ar using a TIAGO Torch show a significant departure from Local Thermodynamic Equilibrium. • Nitrogen entrance from surrounding air highly influences Thermodynamic Equilibrium. • Departure from LTE has been studied by means of Boltzmann plots and b p parameters. • The discharge is ionizing at the nozzle exit plasma, while along the dart it becomes recombining

  11. Theories of blood coagulation.

    Science.gov (United States)

    Riddel, James P; Aouizerat, Bradley E; Miaskowski, Christine; Lillicrap, David P

    2007-01-01

    Although the concept of the coagulation cascade represented a significant advance in the understanding of coagulation and served for many years as a useful model, more recent clinical and experimental observations demonstrate that the cascade/waterfall hypothesis does not fully and completely reflect the events of hemostasis in vivo. The goal of this article is to review the evolution of the theories of coagulation and their proposed models to serve as a tool when reviewing the research and practice literature that was published in the context of these different theories over time.

  12. Dust coagulation in ISM

    Science.gov (United States)

    Chokshi, Arati; Tielens, Alexander G. G. M.; Hollenbach, David

    1989-01-01

    Coagulation is an important mechanism in the growth of interstellar and interplanetary dust particles. The microphysics of the coagulation process was theoretically analyzed as a function of the physical properties of the coagulating grains, i.e., their size, relative velocities, temperature, elastic properties, and the van der Waal interaction. Numerical calculations of collisions between linear chains provide the wave energy in individual particles and the spectrum of the mechanical vibrations set up in colliding particles. Sticking probabilities are then calculated using simple estimates for elastic deformation energies and for the attenuation of the wave energy due to absorption and scattering processes.

  13. Argon in action

    CERN Multimedia

    Corinne Pralavorio

    2015-01-01

    Over the past few days, the SPS has been accelerating argon ions, which have started to be sent to the NA61/SHINE experiment. This operating mode, using a new type of ion, required a number of modifications to the accelerator.   Picture 1: a “super-cycle” of the SPS, featuring a proton cycle for the LHC, followed by an argon ion cycle for the North Area. Today, the accelerators are once again juggling particles and even performing completely new tricks. The SPS is supplying beams of argon ions for the first time, at energies never before achieved for this type of beam. They are destined for the NA61/SHINE experiment (see box) located in the North Area, which began receiving the beams on 11 February. Argon ions have a relatively large mass, as they consist of 40 nucleons, so they can be used in a similar way to lead ions. The main difficulty in accelerating them lies in the SPS, where the variation in acceleration frequency is limited. “The SPS was designed for a...

  14. Carbon dust formation in a cold plasma from cathode sputtering

    International Nuclear Information System (INIS)

    Arnas, C.; Mouberi, A.; Hassouni, K.; Michau, A.; Lombardi, G.; Bonnin, X.; Benedic, F.; Pegourie, B.

    2009-01-01

    Nanoparticles are produced in argon glow plasmas where carbon is introduced by sputtering of a graphite cathode. A scaling law of growth is reported on as a function of the discharge time. Two successive stages of growth of concomitant agglomeration and carbon deposition are observed, followed by a final stage of growth by carbon deposition. A model of formation of molecular precursors by coagulation of neutral clusters on the one hand and of neutral-negative clusters on the other hand is presented, based on formation enthalpy and cluster geometry.

  15. Carbon dust formation in a cold plasma from cathode sputtering

    Science.gov (United States)

    Arnas, C.; Mouberi, A.; Hassouni, K.; Michau, A.; Lombardi, G.; Bonnin, X.; Bénédic, F.; Pégourié, B.

    2009-06-01

    Nanoparticles are produced in argon glow plasmas where carbon is introduced by sputtering of a graphite cathode. A scaling law of growth is reported on as a function of the discharge time. Two successive stages of growth of concomitant agglomeration and carbon deposition are observed, followed by a final stage of growth by carbon deposition. A model of formation of molecular precursors by coagulation of neutral clusters on the one hand and of neutral-negative clusters on the other hand is presented, based on formation enthalpy and cluster geometry.

  16. Disseminated intravascular coagulation (DIC)

    Science.gov (United States)

    ... Jr, Silberstein LE, et al, eds. Hematology: Basic Principles and Practice . 6th ed. Philadelphia, PA: Elsevier Saunders; 2013:chap 141. Thachil J, Toh CH. Current concepts in the management of disseminated intravascular coagulation. Thromb Res . 2012;129 ...

  17. Coagulation and inflammation

    NARCIS (Netherlands)

    van der Poll, T.

    2001-01-01

    Severe infection induces both activation of the coagulation system and multiple other inflammatory mediator cascades. This concise review summarizes the current knowledge of mechanisms that are considered to contribute to the procoagulant response to sepsis. Furthermore, evidence is discussed that

  18. Coagulation and Mental Disorders

    Directory of Open Access Journals (Sweden)

    Silvia Hoirisch-Clapauch

    2014-10-01

    Full Text Available The neurovascular unit is a key player in brain development, homeostasis, and pathology. Mental stress affects coagulation, while severe mental illnesses, such as recurrent depression and schizophrenia, are associated with an increased thrombotic risk and cardiovascular morbidity. Evidence indicates that the hemostatic system is involved to some extent in the pathogenesis, morbidity, and prognosis of a wide variety of psychiatric disorders. The current review focuses on emerging data linking coagulation and some psychiatric disorders.

  19. Hydrogen–argon plasma pre-treatment for improving the anti-corrosion properties of thin Al2O3 films deposited using atomic layer deposition on steel

    International Nuclear Information System (INIS)

    Härkönen, Emma; Potts, Stephen E.; Kessels, Wilhelmus M.M.; Díaz, Belén; Seyeux, Antoine; Światowska, Jolanta; Maurice, Vincent; Marcus, Philippe; Radnóczi, György; Tóth, Lajos; Kariniemi, Maarit; Niinistö, Jaakko; Ritala, Mikko

    2013-01-01

    The effect of H 2 –Ar plasma pre-treatment prior to thermal atomic layer deposition (ALD) and plasma-enhanced atomic layer deposition (PEALD) of Al 2 O 3 films on steel for corrosion protection was investigated. Time-of-flight secondary ion mass spectrometry and transmission electron microscopy were used to observe the changes in the interface. The electrochemical properties of the samples were studied with polarization measurements, and the coating porosities were calculated from the polarization results for easier comparison of the coatings. Prior to thermal ALD the plasma pre-treatment was observed to reduce the amount of impurities at the interface and coating porosity by 1–3 orders of magnitude. The anti-corrosion properties of the PEALD coatings could also be improved by the pre-treatment. However, exposure of the pre-treatment plasma activated steel surface to oxygen plasma species in PEALD led to facile oxide layer formation in the interface. The oxide layer formed this way was thicker than the native oxide layer and appeared to be detrimental to the protective properties of the coating. The best performance for PEALD Al 2 O 3 coatings was achieved when, after the plasma pre-treatment, the surface was given time to regrow a thin protective interfacial oxide prior to exposure to the oxygen plasma. The different effects that thermal and plasma-enhanced ALD have on the substrate-coating interface were compared. The reactivity of the oxygen precursor was shown to have a significant influence on substrate surface in the early stages of film growth and thereafter also on the overall quality of the protective film. - Highlights: • Influence of H 2 –Ar plasma pre-treatment to ALD coatings on steel was studied. • The pre-treatment modified the coating–substrate interface composition and thickness. • The pre-treatment improved the barrier properties of the coatings

  20. Intraventricular hemorrhage in preterm infants: coagulation perspectives.

    Science.gov (United States)

    Kuperman, Amir A; Kenet, Gili; Papadakis, Emmanuel; Brenner, Benjamin

    2011-10-01

    It has long been considered that a severe coagulation deficiency in premature newborns could be a major contributing factor in the occurrence of intraventricular hemorrhage (IVH). High-grade IVH has also been shown to coincide with severe derangement of coagulation in extremely low birth weight infants. This review focuses on the relevance of the physiologically developing immature hemostatic system to IVH, and the potential benefit of agents affecting hemostasis for IVH therapy or prevention in preterm infants. The findings of small, open-label interventional studies on the effect of ethamsylate, vitamin K, fresh frozen plasma, recombinant activated factor VII, and prothrombin complex concentrate on the premature coagulation system will be reviewed. © Thieme Medical Publishers.

  1. One-step argon/nitrogen binary plasma jet irradiation of Li4Ti5O12 for stable high-rate lithium ion battery anodes

    Science.gov (United States)

    Lan, Chun-Kai; Chuang, Shang-I.; Bao, Qi; Liao, Yen-Ting; Duh, Jenq-Gong

    2015-02-01

    Atmospheric pressure Ar/N2 binary plasma jet irradiation has been introduced into the manufacturing process of lithium ions batteries as a facile, green and scalable post-fabrication treatment approach, which enhanced significantly the high-rate anode performance of lithium titanate (Li4Ti5O12). Main emission lines in Ar/N2 plasma measured by optical emission spectroscopy reveal that the dominant excited high-energy species in Ar/N2 plasma are N2*, N2+, N∗ and Ar∗. Sufficient oxygen vacancies have been evidenced by high resolution X-ray photoelectron spectroscopy analysis and Raman spectra. Nitrogen doping has been achieved simultaneously by the surface reaction between pristine Li4Ti5O12 particles and chemically reactive plasma species such as N∗ and N2+. The variety of Li4Ti5O12 particles on the surface of electrodes after different plasma processing time has been examined by grazing incident X-Ray diffraction. Electrochemical impedance spectra (EIS) confirm that the Ar/N2 atmospheric plasma treatment facilitates Li+ ions diffusion and reduces the internal charge-transfer resistance. The as-prepared Li4Ti5O12 anodes exhibit a superior capacity (132 mAh g-1) and excellent stability with almost no capacity decay over 100 cycles under a high C rate (10C).

  2. Application of an argon-nitrogen inductively-coupled radiofrequency plasma (ICP) to the analysis of geological and related materials for their rare earth contents

    Science.gov (United States)

    Brenner, I. B.; Watson, A. E.; Steele, T. W.; Jones, E. A.; Goncalves, M.

    An account is given of the development of a procedure for the determination of the rare earth (RE) elements in a large variety of geological materials employing a medium power argon-nitrogen ICP coupled with a 3.4m Ebert spectrograph. The effects of the carrier and intermediate gas flow rates, height of observation and power on RE spectral line intensities have been studied. The line-to-background ratio of the RE analyte was found to increase with observation height and passed through a maximum at 12-14 mm above the top of the work coil. The method eventually developed allows the direct determination of the lanthanides and yttrium at the 50-200 μg g -1 levels using a single solution prepared by fusing 0.2-1 g samples with Na 2O 2 or LiBO 2 and dissolving the melt in 4-10% (v/v) HNO 3, or by treating the samples with HF-HClO 4-HNO 3 mixtures. For lower contents of the RE elements, they can be separated from matrix concomitants by ion exchange employing AG50W-X8 resin. A large variety of silicate and phosphate reference materials was analysed using scandium as the internal standard. The relative standard deviations vary from about 1.5-15%. No matrix effects were observed despite the large compositional variation of the samples analysed.

  3. Study of a microwave discharge in argon/helium mixtures

    International Nuclear Information System (INIS)

    Saada, Serge

    1983-01-01

    A discharge created by a surface wave in Argon-Helium mixture is studied. First, the helium influence on plasma parameters has been studied (electron density, electric field, effective collision frequency, etc...), then, on excitation processes in the discharge. Relations between plasma lines, electron density and electric field have been established. [fr

  4. Kinetics of Ar+*(2G9/2) metastable ions and transport of argon ions in ICP reactor

    NARCIS (Netherlands)

    Sadeghi, N.; Derouard, J.; Grift, van de M.; Kroesen, G.M.W.; Hoog, de F.J.; Tachibana, K.; Watanabe, Y.

    1997-01-01

    The decay time of the argon Ar~~(2G912) metastable ions was measured in the afterglow of a low pressure pulsed helicon reactor. From the argon pressure and electron density dependence of this decay time, rate coefficients for quenching of these ions by argon atoms and by plasma electrons have been

  5. Isentropic Compression of Argon

    International Nuclear Information System (INIS)

    Oona, H.; Solem, J.C.; Veeser, L.R.; Ekdahl, C.A.; Rodriquez, P.J.; Younger, S.M.; Lewis, W.; Turley, W.D.

    1997-01-01

    We are studying the transition of argon from an insulator to a conductor by compressing the frozen gas isentropically to pressures at which neighboring atomic orbitals overlap sufficiently to allow some electron motion between atoms. Argon and the other rare gases have closed electron shells and therefore remain montomic, even when they solidify. Their simple structure makes it likely that any measured change in conductivity is due to changes in the atomic structure, not in molecular configuration. As the crystal is compressed the band gap closes, allowing increased conductivity. We have begun research to determine the conductivity at high pressures, and it is our intention to determine the compression at which the crystal becomes a metal

  6. The argon excimer laser

    International Nuclear Information System (INIS)

    Wrobel, W.G.

    1981-02-01

    The electron-beam-pumped argon eximer laser is investigated and tuned for the first time. The electron beam is generated by means of an improved coaxial field emmision diode in which argon gas is excited with power densities of 0.3 GW/cm 3 for 18 ns. The processes in the excited gas of 20 to 65 bar are described in the context of a kinetic model as a sequence of stationary states. Investigations of the amplified spontaneous emission (superfluorescence) confirm the predictions of this model. Only the absorption due to the excited Ar atoms is anomalously high. Reproducible operation of the argon eximer laser was achieved in a wide pressure range with various resonator arrangements. The wavelength of this shortest wavelength of this shortest wavelength excimer laser is 126 nm, the laser line width approx. 1.7 nm, the pulse length 7 to 13 ns, and the laser power 250 kW. The laser emission is tuned from 123.2 nm to 128.4 nm by two different methods (diffraction grating and prism). This tunable laser is thus the one with the shortest wavelength at present. Its line width is 0.25 to 0.4 nm, and the power ue 1.7 kW. (orig.)

  7. Investigational drugs for coagulation disorders.

    Science.gov (United States)

    Mannucci, Pier Mannuccio; Mancuso, Maria Elisa

    2013-08-01

    The current standard treatment in persons with hemophilia (PWH) is prophylaxis, given intravenously twice or thrice weekly, which is associated with a non negligible burden on patients' quality of life. Therefore the main attempts aiming to improve the management of PWH are targeted towards the development of a new generation of coagulation factors endowed with properties facilitating prophylaxis and/or a better control of bleeding. This article summarizes the main results obtained so far in the development of new antihemophilic products, and emphasizes the formidable requirements imposed upon by regulatory agencies to get marketing authorization for new drugs, which make progress in this field difficult. Published literature on new molecules for replacement treatment in hemophilia A and B has been retrieved by using PubMed search and all ongoing clinical trials have been looked for online. New molecules are usually engineered to have a longer plasma half-life but also in some instances a higher potency. The prolongation of half-life may be obtained by using sustained release delivery vehicles, by chemical modification or by creating fusion proteins. Factors VIII, IX and VII have been variably modified in order to obtain improved coagulation products and results from Phase I/II studies are encouraging, particularly for factor IX. However, Phase III studies that should provide evidence on efficacy and effectiveness more cogent for clinical use are still ongoing and results are not yet available.

  8. Effect of oxygen atoms dissociated by non-equilibrium plasma on flame of methane oxygen and argon pre-mixture gas

    Science.gov (United States)

    Akashi, Haruaki; Yoshinaga, Tomokazu; Sasaki, Koichi

    2014-10-01

    For more efficient way of combustion, plasma-assisted combustion has been investigated by many researchers. But it is very difficult to clarify the effect of plasma even on the flame of methane. Because there are many complex chemical reactions in combustion system. Sasaki et al. has reported that the flame length of methane and air premixed burner shortened by irradiating microwave power. They also measured emission from Second Positive Band System of nitrogen during the irradiation. The emission indicates existence of high energy electrons which are accelerated by the microwave. The high energy electrons also dissociate oxygen molecules easily and oxygen atom would have some effects on the flame. But the dissociation ratio of oxygen molecules by the non-equilibrium plasma is significantly low, compared to that in the combustion reaction. To clarify the effect of dissociated oxygen atoms on the flame, dependence of dissociation ratio of oxygen on the flame has been examined using CHEMKIN. It is found that in the case of low dissociation ratio of 10-6, the ignition of the flame becomes slightly earlier. It is also found that in the case of high dissociation ratio of 10-3, the ignition time becomes significantly earlier by almost half. This work was supported by KAKENHI (22340170).

  9. The Argon Geochronology Experiment (AGE)

    Science.gov (United States)

    Swindle, T. D.; Bode, R.; Fennema, A.; Chutjian, A.; MacAskill, J. A.; Darrach, M. R.; Clegg, S. M.; Wiens, R. C.; Cremers, D.

    2006-01-01

    This viewgraph presentation reviews the Argon Geochronology Experiment (AGE). Potassium-Argon dating is shown along with cosmic ray dating exposure. The contents include a flow diagram of the Argon Geochronology Experiment, and schematic diagrams of the mass spectrometer vacuum system, sample manipulation mechanism, mineral heater oven, and the quadrupole ion trap mass spectrometer. The Laser-Induced Breakdown Spectroscopy (LIBS) Operation with elemental abundances is also described.

  10. Liquid-argon calorimetry

    International Nuclear Information System (INIS)

    Fabjan, C.W.

    1989-01-01

    In this paper the viability of liquid-argon calorimetric techniques in the experimental environment of the Superconducting Super Collider (SSC) is briefly analyzed. The authors compare the required and achievable energy resolution with benchmark figures obtained using practical instruments. Comments on the desirable (i.e. required) temporal performance are made and compared with the state of the art. Some of the major engineering challenges are listed, for which solutions will have to be developed if such instruments are to find a place in an SSC experimental area

  11. Blood coagulation factor VIII

    Indian Academy of Sciences (India)

    Factor VIII (FVIII) functions as a co-factor in the blood coagulation cascade for the proteolytic activation of factor X by factor IXa. Deficiency of FVIII causes hemophilia A, the most commonly inherited bleeding disorder. This review highlights current knowledge on selected aspects of FVIII in which both the scientist and the ...

  12. Emission and absorption spectroscopy study of Ar excited states in 13.56 MHz argon plasma operating at sub-atmospheric to atmospheric pressure

    Energy Technology Data Exchange (ETDEWEB)

    Li, L. [Department of Applied Physics, Research Unit Plasma Technology, Ghent University, Jozef Plateaustraat 22, Ghent B-9000 (Belgium); Nikiforov, A., E-mail: anton.nikiforov@ugent.be [Department of Applied Physics, Research Unit Plasma Technology, Ghent University, Jozef Plateaustraat 22, Ghent B-9000 (Belgium); Institute of Solution Chemistry of the Russian Academy of Science, Academicheskaya St., 1, Ivanovo, 153045 (Russian Federation); Britun, N. [Chimie des Interactions Plasma-Surface (ChIPS), CIRMAP, Universite de Mons, 23 Place du Parc, B-7000 Mons (Belgium); Snyders, R. [Chimie des Interactions Plasma-Surface (ChIPS), CIRMAP, Universite de Mons, 23 Place du Parc, B-7000 Mons (Belgium); Materia Nova Research Centre, Parc Initialis, B-7000 Mons (Belgium); Leys, C. [Department of Applied Physics, Research Unit Plasma Technology, Ghent University, Jozef Plateaustraat 22, Ghent B-9000 (Belgium)

    2015-05-01

    The densities of metastable and resonant states of Ar atoms are measured in high pressure Ar radio frequency discharge. Resonant absorption spectroscopy for the case of a low pressure spectral lamp and high-pressure plasma absorption lines is implemented for this purpose. The necessary generalizations for the high-pressure resonant absorption method are given. Absolute density of Ar 1s levels obtained at different RF input power and operating pressures are of the order of 10{sup 11} cm{sup −3}, which is in a good agreement with those reported in the literature. The population distribution on the Ar 2p (excited) levels, obtained from the optical emission spectroscopy, reveals strong deviation from thermal equilibrium for these levels in the high-pressure case. The generation of the Ar excited states in the studied discharges is compared to the previously reported results. - Highlights: • Strong non-equilibrium distribution of Ar 2p levels is observed. • The absolute number density of non-radiative Ar 1s states is determined by the easier and low cost spectral-lamp absorption method. • The modified absorption theory of Mitchell and Zemanski was used to obtain the absolute number density of Ar 1s states at high pressure. • The developed RF source with 5 cm long gap can be a possible alternative to micro-plasma working in Ar at atmospheric pressure.

  13. Using the van der Waals broadening of spectral atomic lines to measure the gas temperature of an argon-helium microwave plasma at atmospheric pressure

    International Nuclear Information System (INIS)

    Munoz, J.; Dimitrijevic, M.S.; Yubero, C.; Calzada, M.D.

    2009-01-01

    The applications of plasmas generated with gas mixtures have become increasingly common in different scientific and technological fields. In order to understand the advantages of these discharges, for instance in chemical analysis, it is necessary to know the gas temperature (T g , kinetic energy of the heavy particles) since it has a great influence on the atomization reactions of the molecules located in the discharge, along with the dependence of the reaction rate on this parameter. The ro-vibrational emission spectra of the molecular species are usually used to measure the gas temperature of a discharge at atmospheric pressure although under some experimental conditions, these are difficult to detect. In such cases, the gas temperature can be determined from the van der Waals broadening of the emitted atomic spectral lines related to this parameter. The method proposed is based on the van der Waals broadening taking into account two perturbers

  14. Argon solubility in liquid steel

    NARCIS (Netherlands)

    Boom, R; Dankert, O; Van Veen, A; Kamperman, AA

    2000-01-01

    Experiments have been performed to establish the solubility of argon in liquid interstitial-free steel. The solubility appears to be lower than 0.1 at ppb, The results are in line with argon solubilities reported in the literature on liquid iron. Semiempirical theories and calculations based on the

  15. Effects of argon and oxygen flow rate on water vapor barrier properties of silicon oxide coatings deposited on polyethylene terephthalate by plasma enhanced chemical vapor deposition

    International Nuclear Information System (INIS)

    Kim, Sung-Ryong; Choudhury, Moinul Haque; Kim, Won-Ho; Kim, Gon-Ho

    2010-01-01

    Plasma polymer coatings were deposited from hexamethyldisiloxane on polyethylene terephthalate (PET) substrates while varying the operating conditions, such as the Ar and O 2 flow rates, at a fixed radio frequency power of 300 W. The water vapor transmission rate (WVTR) of the untreated PET was 54.56 g/m 2 /day and was decreased after depositing the silicon oxide (SiO x ) coatings. The minimum WVTR, 0.47 g/m 2 /day, was observed at Ar and O 2 flow rates of 4 and 20 sccm, respectively, with a coating thickness of 415.44 nm. The intensity of the peaks for the Si-O-Si bending at 800-820 cm -1 and Si-O-Si stretching at 1000-1150 cm -1 varied depending on the Ar and O 2 flow rates. The contact angle of the SiO x coated PET increased as the Ar flow rate was increased from 2 to 8 sccm at a fixed O 2 flow rate of 20 sccm. It decreased gradually as the oxygen flow rate increased from 12 to 28 sccm at a fixed Ar carrier gas flow rate. The examination by atomic force microscopy revealed a correlation of the SiO x morphology and the water vapor barrier performance with the Ar and O 2 flow rates. The roughness of the deposited coatings increased when either the O 2 or Ar flow rate was increased.

  16. Study on water-sediment interaction in samples from Rio das Velhas - Minas Gerais State - Brazil using instrumental neutron activation analysis, and argon plasma coupled mass spectroscopy

    International Nuclear Information System (INIS)

    Veado, Maria Adelaide R.V.; Oliveira, Arno H. de; Revel, G.; Pinte, G.; Toulhoat, P.

    1999-01-01

    Sorption of the metallic elements in aqueous solutions in surface of the hydroxides affects the transport of heavy elements in the freshwaters. Sorption and the chemistry of the hydroxides are important studies for knowledge in geology, waters and waste treatment, and environment studies. In the industrial mining region areas, the river surface waters are subject to modifications in its physical and chemistries properties: pH, DBO, conductivity and alkalinity. Instrumental neutron activation analysis and inductively coupled plasma-mass spectrometry (ICP-MS), have ben used for the determination of toxic heavy metals and others pollutants in the Das Velhas river in State of Minas Gerais, in south-east Brazil. Water samples were collected with acidification on site, which provoked a change of its natural pH. Consequently, metallic elements associated to hydroxides and to particles in suspension were liberated. The objective of this paper is to show the different behavior of any elements, in water of Das Velhas river, with relation of its chemical forms (cations or anions), the solubility degree, the pH and the presence of rare earth elements. (author)

  17. Tailoring the surface properties of polypropylene films through cold atmospheric pressure plasma (CAPP) assisted polymerization and immobilization of biomolecules for enhancement of anti-coagulation activity

    International Nuclear Information System (INIS)

    Navaneetha Pandiyaraj, K.; Ram Kumar, M.C.; Arun Kumar, A.; Padmanabhan, P.V.A.; Deshmukh, R.R.; Bah, M.; Ismat Shah, S.; Su, Pi-Guey; Halleluyah, M.; Halim, A.S.

    2016-01-01

    Graphical abstract: - Highlights: • Developed low cost cold atmospheric plasma reactor for plasma polymerization technique. • Surface of the PP film was modified by grafting of AAc and PEG by CAPP polymerization. • Biomolecules of chitosan, insulin and heparin were immobilized on surface of PEG-AAc grafted PP films. • The surface modified PP films were characterized by various techniques. • The plasma polymerized and immobilized film reveals substantial blood compatibility. - Abstract: Enhancement of anti-thrombogenic properties of polypropylene (PP) to avert the adsorption of plasma proteins (fibrinogen and albumin), adhesion and activation of the platelets are very important for vast biomedical applications. The cold atmospheric pressure plasma (CAPP) assisted polymerization has potential to create the specific functional groups such as O−C=O, C=O, C−N and S−S. on the surface of polymeric films using selective precursor in vapour phase to enhance anti-thrombogenic properties. Such functionalized polymeric surfaces would be suitable for various biomedical applications especially to improve the blood compatibility. The eventual aspiration of the present investigation is to develop the biofunctional coating onto the surface of PP films using acrylic acid (AAc) and polyethylene glycol (PEG) as a precursor in a vapour phase by incorporating specific functional groups for immobilization of biomolecules such as heparin (HEP), chitosan (CHI) and insulin (INS) on the surface of plasma modified PP films. The surface properties such as hydrophilicity, chemical composition, surface topography of the surface modified PP films were analyzed by contact angle (CA), Fourier transform infrared spectroscopy (FTIR), X-ray photo electron spectroscopy (XPS) and atomic force microscopy (AFM). Furthermore the anti-thrombogenic properties of the surface modified PP films were studied by in vitro tests which include platelet adhesion and protein adsorption analysis. It was

  18. Tailoring the surface properties of polypropylene films through cold atmospheric pressure plasma (CAPP) assisted polymerization and immobilization of biomolecules for enhancement of anti-coagulation activity

    Energy Technology Data Exchange (ETDEWEB)

    Navaneetha Pandiyaraj, K., E-mail: dr.knpr@gmail.com [Surface Engineering Laboratory, Department of Physics, Sri Shakthi Institute of Engineering and Technology, L& T By Pass, Chinniyam Palayam (Post), Coimbatore 641062 (India); Ram Kumar, M.C.; Arun Kumar, A. [Surface Engineering Laboratory, Department of Physics, Sri Shakthi Institute of Engineering and Technology, L& T By Pass, Chinniyam Palayam (Post), Coimbatore 641062 (India); Padmanabhan, P.V.A. [PSN College of Engineering and Technology, Tirunelveli 627 152 (India); Deshmukh, R.R. [Department of Physics, Institute of Chemical Technology, Matunga, Mumbai 400 019 (India); Bah, M.; Ismat Shah, S. [Department of Physics and Astronomy, Department of Materials Science and Engineering, University of Delaware, 208 Dupont Hall, Newark (United States); Su, Pi-Guey [Department of Chemistry, Chinese Culture University, Taipei 111, Taiwan (China); Halleluyah, M.; Halim, A.S. [School of Medical Sciences, Health Campus, Universiti Sains Malaysia, 16150 Kubang Kerian, Kelantan (Malaysia)

    2016-05-01

    Graphical abstract: - Highlights: • Developed low cost cold atmospheric plasma reactor for plasma polymerization technique. • Surface of the PP film was modified by grafting of AAc and PEG by CAPP polymerization. • Biomolecules of chitosan, insulin and heparin were immobilized on surface of PEG-AAc grafted PP films. • The surface modified PP films were characterized by various techniques. • The plasma polymerized and immobilized film reveals substantial blood compatibility. - Abstract: Enhancement of anti-thrombogenic properties of polypropylene (PP) to avert the adsorption of plasma proteins (fibrinogen and albumin), adhesion and activation of the platelets are very important for vast biomedical applications. The cold atmospheric pressure plasma (CAPP) assisted polymerization has potential to create the specific functional groups such as O−C=O, C=O, C−N and S−S. on the surface of polymeric films using selective precursor in vapour phase to enhance anti-thrombogenic properties. Such functionalized polymeric surfaces would be suitable for various biomedical applications especially to improve the blood compatibility. The eventual aspiration of the present investigation is to develop the biofunctional coating onto the surface of PP films using acrylic acid (AAc) and polyethylene glycol (PEG) as a precursor in a vapour phase by incorporating specific functional groups for immobilization of biomolecules such as heparin (HEP), chitosan (CHI) and insulin (INS) on the surface of plasma modified PP films. The surface properties such as hydrophilicity, chemical composition, surface topography of the surface modified PP films were analyzed by contact angle (CA), Fourier transform infrared spectroscopy (FTIR), X-ray photo electron spectroscopy (XPS) and atomic force microscopy (AFM). Furthermore the anti-thrombogenic properties of the surface modified PP films were studied by in vitro tests which include platelet adhesion and protein adsorption analysis. It was

  19. Overview of the coagulation system

    Directory of Open Access Journals (Sweden)

    Sanjeev Palta

    2014-01-01

    Full Text Available Coagulation is a dynamic process and the understanding of the blood coagulation system has evolved over the recent years in anaesthetic practice. Although the traditional classification of the coagulation system into extrinsic and intrinsic pathway is still valid, the newer insights into coagulation provide more authentic description of the same. Normal coagulation pathway represents a balance between the pro coagulant pathway that is responsible for clot formation and the mechanisms that inhibit the same beyond the injury site. Imbalance of the coagulation system may occur in the perioperative period or during critical illness, which may be secondary to numerous factors leading to a tendency of either thrombosis or bleeding. A systematic search of literature on PubMed with MeSH terms ′coagulation system, haemostasis and anaesthesia revealed twenty eight related clinical trials and review articles in last 10 years. Since the balance of the coagulation system may tilt towards bleeding and thrombosis in many situations, it is mandatory for the clinicians to understand physiologic basis of haemostasis in order to diagnose and manage the abnormalities of the coagulation process and to interpret the diagnostic tests done for the same.

  20. Overview of the coagulation system.

    Science.gov (United States)

    Palta, Sanjeev; Saroa, Richa; Palta, Anshu

    2014-09-01

    Coagulation is a dynamic process and the understanding of the blood coagulation system has evolved over the recent years in anaesthetic practice. Although the traditional classification of the coagulation system into extrinsic and intrinsic pathway is still valid, the newer insights into coagulation provide more authentic description of the same. Normal coagulation pathway represents a balance between the pro coagulant pathway that is responsible for clot formation and the mechanisms that inhibit the same beyond the injury site. Imbalance of the coagulation system may occur in the perioperative period or during critical illness, which may be secondary to numerous factors leading to a tendency of either thrombosis or bleeding. A systematic search of literature on PubMed with MeSH terms 'coagulation system, haemostasis and anaesthesia revealed twenty eight related clinical trials and review articles in last 10 years. Since the balance of the coagulation system may tilt towards bleeding and thrombosis in many situations, it is mandatory for the clinicians to understand physiologic basis of haemostasis in order to diagnose and manage the abnormalities of the coagulation process and to interpret the diagnostic tests done for the same.

  1. Self-production of tissue factor-coagulation factor VII complex by ovarian cancer cells

    OpenAIRE

    Yokota, N; Koizume, S; Miyagi, E; Hirahara, F; Nakamura, Y; Kikuchi, K; Ruf, W; Sakuma, Y; Tsuchiya, E; Miyagi, Y

    2009-01-01

    Background: Thromboembolic events are a major complication in ovarian cancer patients. Tissue factor (TF) is frequently overexpressed in ovarian cancer tissue and correlates with intravascular thrombosis. TF binds to coagulation factor VII (fVII), changing it to its active form, fVIIa. This leads to activation of the extrinsic coagulation cascade. fVII is produced by the liver and believed to be supplied from blood plasma at the site of coagulation. However, we recently showed that ovarian ca...

  2. Influence of ionizing radiation and 12-crown-4 on coagulation system components of rat blood

    International Nuclear Information System (INIS)

    Kratenko, R.Yi.

    2006-01-01

    The influence of 12-crown-4 and ionizing radiation on some components of blood coagulation system: Ca 2+ contents and prostaglandin concentrations in the blood serum, and erythrocyte contents in the blood plasma are studied. The influence of 12-crown-4 and ionizing radiation increases the coagulational properties of erythrocytes. The synergism of ionizing irradiation and 12-crown-4 influence blood coagulation process points out at the occurrence of radiomimetic properties of the latter

  3. Thermophysical properties of multi-shock compressed dense argon.

    Science.gov (United States)

    Chen, Q F; Zheng, J; Gu, Y J; Chen, Y L; Cai, L C; Shen, Z J

    2014-02-21

    In contrast to the single shock compression state that can be obtained directly via experimental measurements, the multi-shock compression states, however, have to be calculated with the aid of theoretical models. In order to determine experimentally the multiple shock states, a diagnostic approach with the Doppler pins system (DPS) and the pyrometer was used to probe multiple shocks in dense argon plasmas. Plasma was generated by a shock reverberation technique. The shock was produced using the flyer plate impact accelerated up to ∼6.1 km/s by a two-stage light gas gun and introduced into the plenum argon gas sample, which was pre-compressed from the environmental pressure to about 20 MPa. The time-resolved optical radiation histories were determined using a multi-wavelength channel optical transience radiance pyrometer. Simultaneously, the particle velocity profiles of the LiF window was measured with multi-DPS. The states of multi-shock compression argon plasma were determined from the measured shock velocities combining the particle velocity profiles. We performed the experiments on dense argon plasmas to determine the principal Hugonoit up to 21 GPa, the re-shock pressure up to 73 GPa, and the maximum measure pressure of the fourth shock up to 158 GPa. The results are used to validate the existing self-consistent variational theory model in the partial ionization region and create new theoretical models.

  4. Ventricular metastasis resulting in disseminated intravascular coagulation

    Directory of Open Access Journals (Sweden)

    Davis Ian D

    2005-05-01

    Full Text Available Abstract Background Disseminated Intravascular Coagulation (DIC complicates up to 7% of malignancies, the commonest solid organ association being adenocarcinoma. Transitional Cell Carcinoma (TCC has rarely been associated with DIC. Case presentation A 74-year-old woman with TCC bladder and DIC was found to have a cardiac lesion suspicious for metastatic disease. The DIC improved with infusion of plasma and administration of Vitamin K, however the cardiac lesion was deemed inoperable and chemotherapy inappropriate; given the patients functional status. We postulate that direct activation of the coagulation cascade by the intraventricular metastasis probably triggered the coagulopathy in this patient. Conclusion Cardiac metastases should be considered in cancer patients with otherwise unexplained DIC. This may influence treatment choices.

  5. The Argon Dark Matter Experiment

    CERN Document Server

    AUTHOR|(CDS)2071720

    2009-01-01

    The ArDM experiment, a 1 ton liquid argon TPC/Calorimeter, is designed for the detection of dark matter particles which can scatter off the spinless argon nucleus, producing nuclear recoils. These events will be discerned by their light to charge ratio, as well as the time structure of the scintillation light. The experiment is presently under construction and commissioning on surface at CERN. Cryogenic operation and light detection performance was recently confirmed in a test run of the full 1 ton liquid argon target under purely calorimetric operation and with a prototype light readout system. This note describes the experimental concept, the main detector components and presents some first results.

  6. Influence of argon impurities on the elastic scattering of x-rays from imploding beryllium capsules

    Science.gov (United States)

    Saunders, A. M.; Chapman, D. A.; Kritcher, A. L.; Schoff, M.; Shuldberg, C.; Landen, O. L.; Glenzer, S. H.; Falcone, R. W.; Gericke, D. O.; Döppner, T.

    2018-03-01

    We investigate the effect of argon impurities on the elastic component of x-ray scattering spectra taken from directly driven beryllium capsule implosions at the OMEGA laser. The plasma conditions were obtained in a previous analysis [18] by fitting the inelastic scattering component. We show that the known argon impurity in the beryllium modifies the elastic scattering due to the larger number of bound electrons. We indeed find significant deviations in the elastic scattering from roughly 1 at.% argon contained in the beryllium. With knowledge of the argon impurity fraction, we use the elastic scattering component to determine the charge state of the compressed beryllium, as the fits are rather insensitive to the argon charge state. Finally, we discuss how doping small fractions of mid- or high-Z elements into low-Z materials could allow ionization balance studies in dense plasmas.

  7. The Liquid Argon Purity Demonstrator

    Energy Technology Data Exchange (ETDEWEB)

    Adamowski, M.; Carls, B.; Dvorak, E.; Hahn, A.; Jaskierny, W.; Johnson, C.; Jostlein, H.; Kendziora, C.; Lockwitz, S.; Pahlka, B.; Plunkett, R.; Pordes, S.; Rebel, B.; Schmitt, R.; Stancari, M.; Tope, T.; Voirin, E.; Yang, T.

    2014-07-01

    The Liquid Argon Purity Demonstrator was an R&D test stand designed to determine if electron drift lifetimes adequate for large neutrino detectors could be achieved without first evacuating the cryostat. We describe here the cryogenic system, its operations, and the apparatus used to determine the contaminant levels in the argon and to measure the electron drift lifetime. The liquid purity obtained by this system was facilitated by a gaseous argon purge. Additionally, gaseous impurities from the ullage were prevented from entering the liquid at the gas-liquid interface by condensing the gas and filtering the resulting liquid before returning to the cryostat. The measured electron drift lifetime in this test was greater than 6 ms, sustained over several periods of many weeks. Measurements of the temperature profile in the argon, to assess convective flow and boiling, were also made and are compared to simulation.

  8. A review of studies of the activation of the blood coagulation mechanism in chimpanzees (Pan troglodytes)

    NARCIS (Netherlands)

    ten Cate, H.; Schenk, B. E.; Biemond, B. J.; Levi, M. [=Marcel M.; van der Poll, T.; Buller, H. R.; ten Cate, J. W.

    1994-01-01

    This paper reviews our recent studies of blood coagulation activation in the chimpanzee which were carried out employing sensitive immunoassays that measure activation markers of blood coagulation in plasma. Infused factor VIIa activated both factors IX and X in vivo; this reaction depended on the

  9. Disseminated intravascular coagulation in solid tumors

    International Nuclear Information System (INIS)

    Terzieff, V.; Alonso, I.; Vázquez, A.

    2004-01-01

    It is estimated that 20-25% of cases of disseminated intravascular coagulation (DIC) relate to an underlying neoplasia primarily hematologic. It is estimated that about 5% of patients with solid tumors have CID clinic, although the incidence of subclinical alterations is much higher. The CID is not limited to the activation of the coagulation cascade, which leads to bleeding micro thrombosis and consumption of coagulation factors. Solid tumors are frequently associated adenocarcinomas producers mucin (especially gastric), usually in the context of a disseminated disease. The mucin may act as a promoter of the cascade, but probably it is a multi-event. High levels of TNF to produced by the tumor mass and chemotherapy-induced cell lysis have Also linked. Although the bleeding is usually oriented diagnosis, the most frequent cause of death is thrombosis. There are no specific tests for diagnosis. Elevated levels of D-dimer and products oriented fibrinogen degradation diagnosis. No reduction fibrinogen and almost always, one thrombocytopenia consumption. Treatment is complex and there is no consensus on many points. To recover the lost factors for consumption, it is recommended to use fresh frozen plasma and / or washed red blood cells. the heparin anticoagulation low dose is indicated since the disease causal can not be controlled quickly, but should not be initiated if there thrombocytopenia 50.000.El under profuse bleeding can require the use of tranexamic acid or EACA. Acute DIC, the case of our patient, is rare and very serious

  10. Tissue regenerating functions of coagulation factor XIII

    DEFF Research Database (Denmark)

    Soendergaard, C; Kvist, P H; Seidelin, J B

    2013-01-01

    The protransglutaminase factor XIII (FXIII) has recently gained interest within the field of tissue regeneration, as it has been found that FXIII significantly influences wound healing by exerting a multitude of functions. It supports haemostasis by enhancing platelet adhesion to damaged......-receptor 2 and the αVβ3 integrin is important for angiogenesis supporting formation of granulation tissue. Chronic inflammatory conditions involving bleeding and activation of the coagulation cascade have been shown to lead to reduced FXIII levels in plasma. Of particular importance for this review...

  11. Coagulation of sheep intestinal and prefemoral lymph.

    Science.gov (United States)

    Hanley, C A; Johnston, M G; Nelson, W

    1988-06-01

    We have determined the most suitable method for the automated analysis of the clotting parameters in sheep intestinal and prefemoral lymph as defined by the Activated Partial Thromboplastin Times (APTT; measure of intrinsic coagulation pathway) and the Prothrombin Times (PT; measure of extrinsic coagulation pathway). As opposed to optical density systems, the use of a Fibro-System Fibrometer was found to provide the most consistent assessment of coagulation with the endpoint being the time to fibrin strand formation. We measured APTT in sheep intestinal and prefemoral lymph of 59.78 +/- 7.69 seconds and 51.03 +/- 10.49 seconds respectively. These values were more prolonged than those obtained from sheep blood plasma but only in the case of intestinal lymph were the differences significant (p less than 0.025). Human blood APTT values were significantly less than both sheep blood (p less than 0.05) and sheep intestinal (p less than 0.001) and prefemoral lymph (p less than 0.01). PT values were found to be 21.56 +/- 1.14 seconds in intestinal and 22.00 +/- 1.88 seconds in prefemoral lymph. These values were also significantly greater than those obtained from sheep blood (both p less than 0.001). Human blood PTs were significantly less than both sheep blood (p less than 0.001) and intestinal and prefemoral lymph (both p less than 0.001). Measurement of APTT and PT values in intestinal lymph and PT determinations in prefemoral lymph were not affected by storage in the refrigerator or freezer. There was some indication that APTT values in prefemoral samples were susceptible to storage artifacts; however, the differences in coagulation times were not significant.

  12. Trauma and Coagulation

    Directory of Open Access Journals (Sweden)

    Murat Yılmaz

    2011-08-01

    Full Text Available Bleeding and coagulation disorders related to trauma are pathological processes which are frequently seen and increase mortality. For the purpose, trauma patients should be protected from hypoperfusion, hypothermia, acidosis and hemodilution which may aggravate the increase in physiological responses to trauma as anticoagulation and fibrinolysis. Performing damage control surgery and resuscitation and transfusion of adequate blood and blood products in terms of amount and content as stated in protocols may increase the rate of survival. Medical treatments augmenting fibrin formation (fibrinogen, desmopressin, factor VIIa or preventing fibrin degradation (tranexamic acid have been proposed in selected cases but the efficacy of these agents in trauma patients are not proven. (Journal of the Turkish Society Intensive Care 2011; 9:71-6

  13. Modelling electroluminescence in liquid argon

    International Nuclear Information System (INIS)

    Stewart, D Y; Barker, G J; Bennieston, A J; Harrison, P F; McConkey, N; Morgan, B; Ramachers, Y A; Lightfoot, P K; Robinson, M; Spooner, N J C; Thompson, L

    2010-01-01

    We present Monte-Carlo simulations of electron transport through liquid argon motivated by our recent observation of electroluminescence light emanating from a thick gaseous electron multiplier (THGEM) in a liquid argon volume. All known elastic and inelastic reaction cross-sections have been accounted for, providing electroluminescence light yield predictions for arbitrary electrostatic fields. This study concludes that the large field gradients needed to produce electroluminescence cannot be accounted for by straightforward electrostatic field calculations based on ideal THGEM holes, suggesting that further experimental investigations are required.

  14. Coagulation of dielectric dust grains due to variable asymmetric charging

    International Nuclear Information System (INIS)

    Manweiler, Jerry W.; Armstrong, Thomas P.; Cravens, Thomas E.

    1998-01-01

    Observational evidence of electrical forces acting significantly on small solids is present for both the modern solar system in Saturn's rings and the ancient solar system in chondritic meteorites. It is likely that grain-grain coagulation rates are affected by the distribution of charges on small grains. Plasma particle impacts and photoelectric effects can provide the charges. It appears that some charging is inevitable and that plasma grain interactions need to be evaluated to determine the size of the effect on coagulation rates. We apply the results of our previous charging work to models of the protoplanetary nebula. It is expected that the protoplanetary nebula is weakly ionized except in certain instances and locations such as: solar flares in the interior, ultraviolet radiation at the outer boundary, and during enhanced luminosity of the star. Since the grains we study are non-conducting and show strong dipole moments in flowing plasma, we modify the geometric cross sections to include the effects of flowing plasma on non-conducting grains with plasma mediated shielding. This paper provides results showing how plasma flow affects the processes involved in charging the grains--total charge and charge distribution. We calculate the modifications to the cross sections and subsequent changes in the coagulation rates

  15. Blood coagulation factors as inflammatory mediators

    NARCIS (Netherlands)

    Schoenmakers, Saskia H. H. F.; Reitsma, Pieter H.; Spek, C. Arnold

    2005-01-01

    After the first observations about blood coagulation by Hippocrates, it took until the early 1900s before the classic theory of blood coagulation was presented. As more and more other coagulation factors were discovered, the four-factor coagulation scheme became more complex, but better understood,

  16. Electric field measurements in the sheath of an argon RF discharge by probing with microparticles under varying gravity conditions

    NARCIS (Netherlands)

    Beckers, J.; Stoffels, W.W.; Kroesen, G.M.W.; Ockenga, T.; Wolter, M.; Kersten, H.

    2010-01-01

    The electric field profile in the plasma sheath of an argon rf plasma has been determined by measuring the equilibrium height and the resonance frequency of plasma-confined microparticles. In order to determine the electric field structure at any position in the plasma sheath without the discharge

  17. Physiological levels of blood coagulation factors IX and X control coagulation kinetics in an in vitro model of circulating tissue factor

    International Nuclear Information System (INIS)

    Tormoen, Garth W; Khader, Ayesha; Gruber, András; McCarty, Owen J T

    2013-01-01

    Thrombosis significantly contributes to cancer morbidity and mortality. The mechanism behind thrombosis in cancer may be circulating tissue factor (TF), as levels of circulating TF are associated with thrombosis. However, circulating TF antigen level alone has failed to predict thrombosis in patients with cancer. We hypothesize that coagulation factor levels regulate the kinetics of circulating TF-induced thrombosis. Coagulation kinetics were measured as a function of individual coagulation factor levels and TF particle concentration. Clotting times increased when pooled plasma was mixed at or above a ratio of 4:6 with PBS. Clotting times increased when pooled plasma was mixed at or above a ratio of 8:2 with factor VII-depleted plasma, 7:3 with factor IX- or factor X-depleted plasmas, or 2:8 with factor II-, V- or VIII-depleted plasmas. Addition of coagulation factors VII, X, IX, V and II to depleted plasmas shortened clotting and enzyme initiation times, and increased enzyme generation rates in a concentration-dependent manner. Only additions of factors IX and X from low-normal to high-normal levels shortened clotting times and increased enzyme generation rates. Our results demonstrate that coagulation kinetics for TF particles are controlled by factor IX and X levels within the normal physiological range. We hypothesize that individual patient factor IX and X levels may be prognostic for susceptibility to circulating TF-induced thrombosis. (paper)

  18. Geminate recombination in liquid argon

    International Nuclear Information System (INIS)

    Freeman, G.R.

    1984-01-01

    The extended Onsager model for geminate neutralization is supported by the field dependence of the ionization yield in liquid argon irradiated by high energy electrons or x rays. Attempts to employ the model fail unless the distribution of initial separation distances between the thermalized electrons and their sibling ions (secondary electron thermalization ranges) is included. Data of Scalettar and co-workers are reanalyzed

  19. Electron densities and energies of a guided argon streamer in argon and air environments

    International Nuclear Information System (INIS)

    Hübner, S; Hofmann, S; Van Veldhuizen, E M; Bruggeman, P J

    2013-01-01

    In this study we report the temporally and spatially resolved electron densities and mean energies of a guided argon streamer in ambient argon and air obtained by Thomson laser scattering. The plasma is driven by a positive monopolar 3.5 kV pulse, with a pulse width of 500 ns and a frequency of 5 kHz which is synchronized with the high repetition rate laser system. This configuration enables us to use the spatial and temporal stability of the guided streamer to accumulate a multitude of laser/plasma shots by a triple grating spectrometer equipped with an ICCD camera and to determine the electron parameters. We found a strong initial n e -overshoot with a maximum of 7 × 10 19  m −3 and a mean electron energy of 4.5 eV. This maximum is followed by a fast decay toward the streamer channel. Moreover, a 2D distribution of the electron density is obtained which exhibits a peculiar mushroom-like shape of the streamer head with a diameter significantly larger than that of the emission profile. A correlation of the width of the streamer head with the expected pre-ionization channel is found. (paper)

  20. Liquid Argon Barrel Cryostat Arrived

    CERN Multimedia

    Pailler, P

    Last week the first of three cryostats for the ATLAS liquid argon calorimeter arrived at CERN. It had travelled for 46 days over several thousand kilometers from Japan to CERN. During three years it has been fabricated by Kawasaki Heavy Industries Ltd. at Harima, close to Kobe, under contract from Brookhaven National Laboratory (BNL) of the U.S.. This cryostat consists of two concentric cylinders made of aluminium: the outer vacuum vessel with a diameter of 5.5 m and a length of 7 m, and the inner cold vessel which will contain the electromagnetic barrel calorimeter immersed in liquid argon. The total weight will be 270 tons including the detectors and the liquid argon. The cryostat is now located in building 180 where it will be equipped with 64 feed-throughs which serve for the passage of 122,880 electrical lines which will carry the signals of the calorimeter. After integration of the calorimeter, the solenoidal magnet of ATLAS will be integrated in the vacuum vessel. A final cold test of the cryostat inc...

  1. Theoretical and experimental comparisons of Gamble 2 argon gas puff experiments

    International Nuclear Information System (INIS)

    Thornhill, J.W.; Young, F.C.; Whitney, K.G.; Davis, J.; Stephanakis, S.J.

    1990-01-01

    A one-dimensional radiative MHD analysis of an imploding argon gas puff plasma is performed. The calculations are set up to approximate the conditions of a series of argon gas puff experiments that were carried out on the NRL Gamble II generator. Annular gas puffs (2.5 cm diameter) are imploded with a 1.2-MA peak driving current for different initial argon mass loadings. Comparisons are made with the experimental results for implosion times, K, L-shell x-ray emission, and energy coupled from the generator to the plasma load. The purpose of these calculations is to provide a foundation from which a variety of physical phenomena which influence the power and total energy of the x-ray emission can be analyzed. Comparisons with similar experimental and theoretical results for aluminum plasmas are discussed

  2. The interplay between platelets and coagulation

    NARCIS (Netherlands)

    Weeterings, C.

    2009-01-01

    Platelet activation and blood coagulation are two processes often studied separately, but which cannot be seen independently from each other. Platelets play a pivotal role in coagulation, not only by providing negatively charged phospholipids, but also in localizing the coagulation process from a

  3. Coagulants modulate the hypocholesterolemic effect of tofu ...

    African Journals Online (AJOL)

    hope&shola

    2006-02-02

    Feb 2, 2006 ... The recent increase in soymilk and tofu (coagulated soymilk) consumption especially in western countries is due to the recognition of the health benefits of soy foods. The amount and the type of coagulated biomolecules (such as isoflavones) vary with the type of coagulant, and this will inevitable alter their ...

  4. Prospects for photosensitive dopants in liquid argon

    International Nuclear Information System (INIS)

    Anderson, D.F.

    1990-12-01

    Evidence is presented that the addition of a few ppM of a photosensitive dopant to a U/liquid argon or Pb/liquid argon calorimeter will make a substantial reduction in the e/π ratio. Previous results indicating high voltage problems and no change in the e/π ratio in tests of photosensitive dopants with the Fermilab D0 experiment's U/liquid argon tests calorimeter are also explained. 13 refs., 3 figs

  5. Chronic sleep deprivation markedly reduces coagulation factor VII expression

    Science.gov (United States)

    Pinotti, Mirko; Bertolucci, Cristiano; Frigato, Elena; Branchini, Alessio; Cavallari, Nicola; Baba, Kenkichi; Contreras-Alcantara, Susana; Ehlen, J. Christopher; Bernardi, Francesco; Paul, Ketema N.; Tosini, Gianluca

    2010-01-01

    Chronic sleep loss, a common feature of human life in industrialized countries, is associated to cardiovascular disorders. Variations in functional parameters of coagulation might contribute to explain this relationship. By exploiting the mouse model and a specifically designed protocol, we demonstrated that seven days of partial sleep deprivation significantly decreases (−30.5%) the thrombin generation potential in plasma evaluated upon extrinsic (TF/FVIIa pathway) but not intrinsic activation of coagulation. This variation was consistent with a decrease (−49.8%) in the plasma activity levels of factor VII (FVII), the crucial physiologicalal trigger of coagulation, which was even more pronounced at the liver mRNA level (−85.7%). The recovery in normal sleep conditions for three days completely restored thrombin generation and FVII activity in plasma. For the first time, we demonstrate that chronic sleep deprivation on its own reduces, in a reversible manner, the FVII expression levels, thus influencing the TF/FVIIa activation pathway efficiency. PMID:20418241

  6. Effects of oversulfated and fucosylated chondroitin sulfates on coagulation. Challenges for the study of anticoagulant polysaccharides.

    Science.gov (United States)

    Fonseca, Roberto J C; Oliveira, Stephan-Nicollas M C G; Pomin, Vitor H; Mecawi, André S; Araujo, Iracema G; Mourão, Paulo A S

    2010-05-01

    We report the effects of a chemically oversulfated chondroitin sulfate and a naturally fucosylated chondroitin sulfate on the coagulation system. The former has been recently identified as a contaminant of heparin preparations and the latter has been proposed as an alternative anticoagulant. The mechanism of action of these polymers on coagulation is complex and target different components of the coagulation system. They have serpin-independent anticoagulant activity, which preponderates in plasma. They also have serpin-dependent anticoagulant activity but differ significantly in the target coagulation protease and preferential serpin. Their anticoagulant effects differ even more markedly when tested as inhibitors of coagulation proteases using plasma as a source of serpins. It is possible that the difference is due to the high availability of fucosylated chondroitin sulfate whereas oversulfated chondroitin sulfate has strong unspecific binding to plasma protein and low availability for the binding to serpins. When tested using a venous thrombosis experimental model, oversulfated chondroitin sulfate is less potent as an antithrombotic agent than fucosylated chondroitin sulfate. These highly sulfated chondroitin sulfates activate factor XII in in vitro assays, based on kallikrein release. However, only fucosylated chondroitin sulfate induces hypotension when intravenously injected into rats. In conclusion, the complexity of the regulatory mechanisms involved in the action of highly sulfated polysaccharides in coagulation requires their analysis by a combination of in vitro and in vivo assays. Our results are relevant due to the urgent need for new anticoagulant drugs or alternative sources of heparin.

  7. Computer simulation of cooling properties of UF5 hot-clusters in argon

    International Nuclear Information System (INIS)

    Okamoto, Tsuyoshi; Ohno, Fubito

    1999-01-01

    Brownian collision-coalescence models have been proposed by many researchers to describe a cluster or a particle growth process. In these mathematical models, the effect of a cluster temperature on a sticking probability is not included, although the cluster temperature is one of the most important factors which determines the particle growth rate at the incipient stage of coagulation. A hot-cluster consisting of 30 UF 5 molecules is formed in a computer and is bombarded with argon atoms. Measuring a kinetic energy of argon atom scattered from the hot-cluster, the cluster temperature can be estimated by molecular dynamics simulations. It is concluded that the hot-cluster is rapidly cooled under the conditions of molecular laser isotope separation (MLIS) process, so that the cluster-argon system can reach its thermal equilibrium state. Therefore, in the analysis of the dynamics of clustering process, the temperature of UF 5 molecular cluster may be set equal to that of argon gas. (author)

  8. Effects of argon laser on atheromatous plaques. A preliminary study on post-mortem arterial specimens

    International Nuclear Information System (INIS)

    Pernes, J.M.; Angel, C.Y.; Brenot, P.; Bruneval, P.; Camilleri, J.P.; Gaux, J.C.

    1985-01-01

    The effects of argon laser radiation of human atheroma were studied in vitro. Lesions produced were craters from total tissue volatilization surrounded by a thin zone of coagulation. The degree of tissue destruction was related to the energy used and the direction of the laser beam in relation to the atheromatous stenotic lesion. These findings confirm that it is possible to destroy the atheroma under controlled conditions, but a the non-negligeable risk of perforation. By allowing visual control, the angioscope should ensure increased safety in use and provide hope for future applications of this method by the percutaneous route in the treatment of established atheromatous disease [fr

  9. Argon Kα measurement on DIII endash D by Ross filters technique (abstract)

    International Nuclear Information System (INIS)

    Snider, R.T.; Bogatu, I.N.; Brooks, N.H.; Wade, M.R.

    1999-01-01

    Techniques to reduce the heat flux to the divertor plates in tokamak power plants and the consequent erosion of, and subsequent damage to the divertor target plates include the injection of impurities such as argon, that can dissipate the energy (through radiative or collisional processes) before it reaches the target plates. An important issue with this type of scheme is poisoning of the plasma core by the impurities introduced in the divertor region. Subsequently, there is a desire to measure the profiles of the injected impurities in the core. X-ray Ross filters with an effective narrow band pass centered on the argon Kα line at 3.2 keV, have been installed on two of the existing x-ray arrays on DIII endash D in order to help determine the argon concentration profiles. Emissivity profiles of the Kα lines and the emissivity profiles for the argon enhanced continuum can be inferred from the inverted filtered x-ray brightness signals if T e , n e , and Ar 18+ profiles are known. The MIST code is used to couple the filtered x-ray signals to the time dependent measurements of T e and n e . Further, the Ar 16+ profiles measured by charge transfer spectroscopy, are used as a constraint on the MIST code runs to calculate Ar 18+ profiles and unfold the argon emissivity profiles. A discussion of the Ross filters, the DIII endash D argon data, and the data analysis scheme for inferring argon emissivity profiles will be discussed. Estimates of the total argon concentration in the core determined from this technique in DIII endash D argon puff experiments will be presented. copyright 1999 American Institute of Physics

  10. Separation of seven arsenic compounds by high performance liquid chromatography with on-line detection by hydrogen-argon flame atomic absorption spectrometry and inductively coupled plasma mass spectrometry

    DEFF Research Database (Denmark)

    Hansen, S. H.; Larsen, Erik Huusfeldt; Pritzl, G.

    1992-01-01

    -to-noise ratio of the on-line AAS detector was optimized. This involved the use of the hydrogen-argon-entrained air flame, a slotted tube atom trap in the flame for signal enhancement, electronic noise damping and a high-intensity light source. The detection limits in mu-g cm-3, using 100 mm3 injections...... of mixtures of arsenic standards into the HPLC system were: arsenite, As(III) 1.1; arsenate, As(V) 1.4; MMA 1.4; DMA 0.7; AsB 0.3; AsC 0.5; and the TMAs 0.4. The HPLC-AAS system was used for the analysis of arsenic species in aqueous extracts of soil samples from a polluted land site. Only arsenate was found...

  11. Influence of easily ionised elements on the delayed responses of the emission intensities of an analyte in a power modulated U-shaped argon stabilised DC arc plasma with an aerosol supply

    Directory of Open Access Journals (Sweden)

    MIROSLAV KUZMANOVIC

    2005-09-01

    Full Text Available The current of a U-shaped argon stabilised DC arc was square modulated with a 40 Hz repetition frequency between 6 and 3 A. The delayed line intensity responses to the modulation of the arc current were investigated using calcium as a representative analyte. The intensities of both the atomic and ionic lines were monitored at different distances from the arc axis in the presence of various concentrations of the easily ionised element. Temporal evolutions were monitored on a millisecond time scale. It was found that the responses of the line intesity to the arc current change strongly depended on the observed radial position, especially in the vicinity of the arc axis. The obtained results showed a significant influence of even small amounts of the easily ionised element on the excitation and transport of the analyte and indicated a way of possibly improving the analytical capabilities of the excitation source.

  12. Effects of oxygen concentration on atmospheric pressure dielectric barrier discharge in Argon-Oxygen Mixture

    Science.gov (United States)

    Li, Xuechun; Li, Dian; Wang, Younian

    2016-09-01

    A dielectric barrier discharge (DBD) can generate a low-temperature plasma easily at atmospheric pressure and has been investigated for applications in trials in cancer therapy, sterilization, air pollution control, etc. It has been confirmed that reactive oxygen species (ROS) play a key role in the processes. In this work, we use a fluid model to simulate the plasma characteristics for DBD in argon-oxygen mixture. The effects of oxygen concentration on the plasma characteristics have been discussed. The evolution mechanism of ROS has been systematically analyzed. It was found that the ground state oxygen atoms and oxygen molecular ions are the dominated oxygen species under the considered oxygen concentrations. With the oxygen concentration increasing, the densities of electrons, argon atomic ions, resonance state argon atoms, metastable state argon atoms and excited state argon atoms all show a trend of decline. The oxygen molecular ions density is high and little influenced by the oxygen concentration. Ground state oxygen atoms density tends to increase before falling. The ozone density increases significantly. Increasing the oxygen concentration, the discharge mode begins to change gradually from the glow discharge mode to Townsend discharge mode. Project supported by the National Natural Science Foundation of China (Grant No. 11175034).

  13. Liquid argon calorimetry for the SSC

    International Nuclear Information System (INIS)

    Gordon, H.A.

    1990-01-01

    Liquid argon calorimetry is a mature technique. However, adapting it to the challenging environment of the SSC requires a large amount of R ampersand D. The advantages of the liquid argon approach are summarized and the issues being addressed by the R ampersand D program are described. 18 refs

  14. Electron energy distributions and excitation rates in high-frequency argon discharges

    International Nuclear Information System (INIS)

    Ferreira, C.M.; Loureiro, J.

    1983-06-01

    The electron energy distribution functions and rate coefficients for excitation and ionisation in argon under the action of an uniform high-frequency electric field were calculated by numerically solving the homogeneous Boltzmann equation. Analytic calculations in the limiting cases ω>>νsub(c) and ω<<νsub(c), where ω is the wave angular frequency and νsub(c) is the electron-neutral collision frequency for momentum transfer, are also presented and shown to be in very good agreement with the numerical computations. The results reported here are relevant for the modelling of high-frequency discharges in argon and, in particular, for improving recent theoretical descriptions of a plasma column sustained by surface microwaves. The properties of surface wave produced plasmas make them interesting as possible substitutes for other more conventional plasma sources for such important applications as plasma chemistry laser excitation, plasma etching spectroscopic sources etc...

  15. Coagulation Status in Hidradenitis Suppurativa

    DEFF Research Database (Denmark)

    Miller, Iben Marie; Johansen, Maria Egede; Mogensen, Ulla B

    2015-01-01

    BACKGROUND: Chronic inflammatory diseases other than hidradenitis suppurativa (HS) have been associated with prothrombotic/hypercoagulable status. OBJECTIVE: To investigate a possible association between the chronic inflammatory skin disease HS and prothrombotic/hypercoagulable state. METHODS: We.......3432). CONCLUSION: We did not find an association between HS and prothrombotic/hypercoagulable status. Thus, thrombocytes may not be activated in HS. Furthermore, INR may not be affected in HS, suggesting that intrinsic and vitamin K-dependent coagulation factors appear unaffected....

  16. Blood coagulation and the risk of atherothrombosis: a complex relationship

    Directory of Open Access Journals (Sweden)

    van der Voort Danielle

    2004-12-01

    Full Text Available Abstract The principles of Virchov's triad appear to be operational in atherothrombosis or arterial thrombosis: local flow changes and particularly vacular wall damage are the main pathophysiological elements. Furthermore, alterations in arterial blood composition are also involved although the specific role and importance of blood coagulation is an ongoing matter of debate. In this review we provide support for the hypothesis that activated blood coagulation is an essential determinant of the risk of atherothrombotic complications. We distinguish two phases in atherosclerosis: In the first phase, atherosclerosis develops under influence of "classical" risk factors, i.e. both genetic and acquired forces. While fibrinogen/fibrin molecules participate in early plaque lesions, increased activity of systemic coagulation is of no major influence on the risk of arterial thrombosis, except in rare cases where a number of specific procoagulant forces collide. Despite the presence of tissue factor – factor VII complex it is unlikely that all fibrin in the atherosclerotic plaque is the direct result from local clotting activity. The dominant effect of coagulation in this phase is anticoagulant, i.e. thrombin enhances protein C activation through its binding to endothelial thrombomodulin. The second phase is characterized by advancing atherosclerosis, with greater impact of inflammation as indicated by an elevated level of plasma C-reactive protein, the result of increased production influenced by interleukin-6. Inflammation overwhelms protective anticoagulant forces, which in itself may have become less efficient due to down regulation of thrombomodulin and endothelial cell protein C receptor (EPCR expression. In this phase, the inflammatory drive leads to recurrent induction of tissue factor and assembly of catalytic complexes on aggregated cells and on microparticles, maintaining a certain level of thrombin production and fibrin formation. In advanced

  17. The Mast Cell, Contact, and Coagulation System Connection in Anaphylaxis

    Directory of Open Access Journals (Sweden)

    Mar Guilarte

    2017-07-01

    Full Text Available Anaphylaxis is the most severe form of allergic reaction, resulting from the effect of mediators and chemotactic substances released by activated cells. Mast cells and basophils are considered key players in IgE-mediated human anaphylaxis. Beyond IgE-mediated activation of mast cells/basophils, further mechanisms are involved in the occurrence of anaphylaxis. New insights into the potential relevance of pathways other than mast cell and basophil degranulation have been unraveled, such as the activation of the contact and the coagulation systems. Mast cell heparin released upon activation provides negatively charged surfaces for factor XII (FXII binding and auto-activation. Activated FXII, the initiating serine protease in both the contact and the intrinsic coagulation system, activates factor XI and prekallikrein, respectively. FXII-mediated bradykinin (BK formation has been proven in the human plasma of anaphylactic patients as well as in experimental models of anaphylaxis. Moreover, the severity of anaphylaxis is correlated with the increase in plasma heparin, BK formation and the intensity of contact system activation. FXII also activates plasminogen in the fibrinolysis system. Mast cell tryptase has been shown to participate in fibrinolysis through plasmin activation and by facilitating the degradation of fibrinogen. Some usual clinical manifestations in anaphylaxis, such as angioedema or hypotension, or other less common, such as metrorrhagia, may be explained by the direct effect of the activation of the coagulation and contact system driven by mast cell mediators.

  18. Vascular anastomosis by Argon Laser

    International Nuclear Information System (INIS)

    Gomes, O.M.; Macruz, R.; Armelin, E.; Brum, J.M.G.; Ribeiro, M.P.; Mnitentog, J.; Verginelli, G.; Pileggi, F.; Zerbini, E.J.

    1982-01-01

    Twenty four mongrel dogs, wheighing 13 to 24 kilograms were studied. After anesthesia, intubation and controlled ventilation, they were submitted to three types of vascular anastomosis: Group I - eight dogs with saphenous vein inter-carotid arteries by-pass: Group II - eight dogs with left mammary artery - left anterior descending coronary artery by-pass; Group III - eight dogs with venovenous anastomosis. In all groups 0.8 to 15 watts of Argon Laser power was applied to a total time of 90 to 300 seconds. The lower power for venovenous anastomosis and the greater for the arterial ones. The mean valves of resistence of the Laser anastomosis to pressure induced rupture was 730 mmHg in the immediate post operative study, and superior to 2.500 mmHg 30 days after. No signs of occlusion was demonstrated at the anastomosis sites by the angiographic and anathomo-patological study performed. (Author) [pt

  19. Spectral investigation of a complex space charge structure in plasma

    International Nuclear Information System (INIS)

    Gurlui, S.; Dimitriu, D. G.; Ionita, C.; Schrittwieser, R. W.

    2009-01-01

    Complex space charge structures bordered by electrical double layers were spectrally investigated in argon plasma in the domain 400-1000 nm, identifying the lines corresponding to the transitions from different excited states of argon. The electron excitation temperature in the argon atoms was estimated from the spectral lines intensity ratio. (authors)

  20. Multipurpose HTS Coagulation Analysis: Assay Development and Assessment of Coagulopathic Snake Venoms

    Directory of Open Access Journals (Sweden)

    Kristina B. M. Still

    2017-11-01

    Full Text Available Coagulation assays currently employed are often low throughput, require specialized equipment and/or require large blood/plasma samples. This study describes the development, optimization and early application of a generic low-volume and high-throughput screening (HTS assay for coagulation activity. The assay is a time-course spectrophotometric measurement which kinetically measures the clotting profile of bovine or human plasma incubated with Ca2+ and a test compound. The HTS assay can be a valuable new tool for coagulation diagnostics in hospitals, for research in coagulation disorders, for drug discovery and for venom research. A major effect following envenomation by many venomous snakes is perturbation of blood coagulation caused by haemotoxic compounds present in the venom. These compounds, such as anticoagulants, are potential leads in drug discovery for cardiovascular diseases. The assay was implemented in an integrated analytical approach consisting of reversed-phase liquid chromatography (LC for separation of crude venom components in combination with parallel post-column coagulation screening and mass spectrometry (MS. The approach was applied for the rapid assessment and identification of profiles of haemotoxic compounds in snake venoms. Procoagulant and anticoagulant activities were correlated with accurate masses from the parallel MS measurements, facilitating the detection of peptides showing strong anticoagulant activity.

  1. Diagnostics of Argon Injected Hydrogen Peroxide Added High Frequency Underwater Capillary Discharge

    Directory of Open Access Journals (Sweden)

    Muhammad Waqar Ahmed

    2016-05-01

    Full Text Available The effects of hydrogen peroxide addition and Argon injection on electrical and spectral characteristics of underwater capillary discharge were investigated. The flowing water discharge was created in a quartz tube (Φ = 4mm outer; Φ = 2mm inner; thickness 1mm by applying high frequency (25 kHz alternating current voltage (0-15kV across the tungsten electrodes (Φ=0.5mm, in pin-pin electrode configuration, separated by a gap distance of 10 mm. The results of no hydrogen peroxide addition and no Argon gas injection were compared with addition of hydrogen peroxide and Argon injection for different values. The emission spectrum was taken to present the increase in concentration of •OH radicals with and without hydrogen peroxide addition under different argon injection rates. The results demonstrated that addition of hydrogen peroxide do not remarkably affected the conductivity of water, but its addition increased the yield rate of •OH radicals generated by plasma discharge. The addition of Argon generated bubbles and gas channels reduced the high power consumption required for inducing flowing water long gap discharge. The results showed large concentration of •OH radicals due to hydrogen peroxide addition, less required input power for generating flowing water discharge by using high frequency input voltage and due to Argon injection.

  2. Emissive spectra of shock-heated argon

    International Nuclear Information System (INIS)

    Tang Jingyou; Gu Yan; Peng Qixian; Bai Yulin; Li Ping

    2003-01-01

    To study the radiant properties of argon under weak shock compression, an aluminum target filled with gaseous argon at ambient states was impacted by a tungsten alloy projectile which was launched from a two-stage light gun to 2.00 km/s. The radiant signals of single shock-compressed argon were recorded by a six-channel pyrometer and oscilloscopes, which varied with time linearly for the five channels from 405 nm to 700 nm and exponentially for the channel 800 nm, and the corresponding velocity of shock wave was determined to be 4.10 ± 0.09 km/s. By the present experiment, it has been shown that the absorbability of the shock-heated argon is low for visual light and the optical depths of argon gas turn from thin to thick as wavelengths gradually increase. The time-resolved spectra in the rising-front of the radiant signal in the re-shocked argon were recorded by means of an OMA, and strong emissive spectrum bands near 450 nm light-wave length but no linear spectrum were found. The emissive spectrum properties of shock-compression argon were qualitatively explained by the state parameters and ionization degree

  3. The formation of a turbulent front in a time modulated argon APPJ

    NARCIS (Netherlands)

    Zhang, S.; Veldhuizen, van E.M.; Bruggeman, P.J.; Sobota, A.

    2014-01-01

    Cold atmospheric pressure plasma jets (APPJ) are promising tools for biomedical applications such as wound healing, disinfection, decontamination, and material processing. The jet effluent is blown in an open air environment which leads to air diffusion and argon-air mixtures in the effluent flow.

  4. Argon cover gas purity control on LMFBR

    Energy Technology Data Exchange (ETDEWEB)

    Maeda, Hiroshi; Kobayashi, Takayoshi [PNC (Japan); Ishiyama, Satoshi [Toshiba (Japan); Motonaga, Tetsuji [Hitachi (Japan)

    1987-07-01

    Various control methods on chemical impurities and radioactive materials (fission products) in the primary argon gas of LMFBRs' have been studied based on experiences in Joyo and results of research and development. These results are reflected on MONJU design. On-line gas chromatographs are installed both in the Primary and in the Secondary Argon Gas Systems in JOYO. Also, chemical analysis has been done by batch sampling in JOYO. Though the rise of impurity concentration had been measured after periodical fuel exchange operation, impurity concentration has been controlled sufficiently under target control limits. In MONJU detailed design, the Rare Gas Removal and Recovery System which consisted of cryogenic distillation equipment had been eliminated and the capacity of Charcoal Beds in the Primary Argon Gas System has been improved to keep the concentration of radioactive materials sufficient low levels. The necessity to control the impurities in fresh argon gas which is supplied to the Primary Argon Gas System is now considered to keep the concentration of Kr and Xe isotopes in specified level, because their isotopes may make background rise for the Tagging Gas Failed Fuel Detection and Location System. Based on various investigations performed on sodium vapor trapping to obtain its detailed characteristics, design specifications and operating conditions of MONJU's Vapor Traps have been decided. To keep the level of radioactivity in gaseous effluents to the environment as low as reasonably achievable, the following means are now adopted in MONJU: the Primary Argon Gas System is composed of a closed recirculating path, but the exhaust gas discharged has different path after the Charcoal Beds; fresh argon gas is blown down to prevent Primary Argon Gas from releasing to the circumference during opening of the primary argon gas boundary, such as fuel exchange operations. (author)

  5. Virial Coefficients for the Liquid Argon

    Science.gov (United States)

    Korth, Micheal; Kim, Saesun

    2014-03-01

    We begin with a geometric model of hard colliding spheres and calculate probability densities in an iterative sequence of calculations that lead to the pair correlation function. The model is based on a kinetic theory approach developed by Shinomoto, to which we added an interatomic potential for argon based on the model from Aziz. From values of the pair correlation function at various values of density, we were able to find viral coefficients of liquid argon. The low order coefficients are in good agreement with theoretical hard sphere coefficients, but appropriate data for argon to which these results might be compared is difficult to find.

  6. Effect of fibrinogen on blood coagulation detected by optical coherence tomography

    International Nuclear Information System (INIS)

    Xu, Xiangqun; Teng, Xiangshuai

    2015-01-01

    Our previous work demonstrated that an optical coherence tomography (OCT) technique and the parameter 1/e light penetration depth (d 1/e ) were able to characterize the whole blood coagulation process in contrast to existing optical tests that are performed on plasma samples. To evaluate the feasibility of the technique for quantifying the effect of fibrinogen (Fbg) on blood coagulation, a dynamic study of d 1/e of blood in various Fbg concentrations was performed in static state. Two groups of blood samples of hematocrit (HCT) in 35, 45, and 55% were reconstituted of red blood cells with: 1) treated plasma with its intrinsic Fbg removed and commercial Fbg added (0–8 g L −1 ); and 2) native plasma with commercial Fbg added (0–8 g L −1 ). The results revealed a typical behavior due to coagulation induced by calcium ions and the clotting time is Fbg concentration-dependent. The clotting time was decreased by the increasing amount of Fbg in both groups. Besides, the blood of lower HCT with various levels of Fbg took shorter time to coagulate than that of higher HCT. Consequently, the OCT method is a useful and promising tool for the detection of blood-coagulation processes induced with different Fbg levels. (paper)

  7. Observation of Ω mode electron heating in dusty argon radio frequency discharges

    Energy Technology Data Exchange (ETDEWEB)

    Killer, Carsten; Bandelow, Gunnar; Schneider, Ralf; Melzer, André [Institut für Physik, Ernst-Moritz-Arndt-Universität Greifswald, 17489 Greifswald (Germany); Matyash, Konstantin [Universitätsrechenzentrum, Ernst-Moritz-Arndt-Universität Greifswald, 17489 Greifswald (Germany)

    2013-08-15

    The time-resolved emission of argon atoms in a dusty plasma has been measured with phase-resolved optical emission spectroscopy using an intensified charge-coupled device camera. For that purpose, three-dimensional dust clouds have been confined in a capacitively coupled rf argon discharge with the help of thermophoretic levitation. While electrons are exclusively heated by the expanding sheath (α mode) in the dust-free case, electron heating takes place in the entire plasma bulk when the discharge volume is filled with dust particles. Such a behavior is known as Ω mode, first observed in electronegative plasmas. Furthermore, particle-in-cell simulations have been carried out, which reproduce the trends of the experimental findings. These simulations support previous numerical models showing that the enhanced atomic emission in the plasma can be attributed to a bulk electric field, which is mainly caused by the reduced electrical conductivity due to electron depletion.

  8. Plasma processes and film growth of expanding thermal plasma deposited textured zinc oxide

    NARCIS (Netherlands)

    Groenen, R.; Linden, J.L.; Sanden, van de M.C.M.

    2005-01-01

    Plasma processes and film growth of textured zinc oxide deposited from oxygen and diethyl zinc utilizing expanding thermal argon plasma created by a cascaded arc is discussed. In all conditions explored, an excess of argon ions and low temperature electrons is available, which represent the

  9. High-resolution measurement, line identification, and spectral modeling of the Kβ spectrum of heliumlike argon emitted by a laser-produced plasma using a gas-puff target

    International Nuclear Information System (INIS)

    Skobelev, I.Y.; Faenov, A.Y.; Dyakin, V.M.; Fiedorowicz, H.; Bartnik, A.; Szczurek, M.; Beiersdorfer, P.; Nilsen, J.; Osterheld, A.L.

    1997-01-01

    We present an analysis of the spectrum of satellite transitions to the He-β line in ArXVII. High-resolution measurements of the spectra from laser-heated Ar-gas-puff targets are made with spectral resolution of 10000 and spatial resolution of better than 50 μm. These are compared with tokamak measurements. Several different lines are identified in the spectra and the spectral analysis is used to determine the plasma parameters in the gas-puff laser-produced plasma. The data complement those from tokamak measurements to provide more complete information on the satellite spectra. copyright 1997 The American Physical Society

  10. Parametric Study of Hybrid Argon-Water Stabilized Electric Arc under Subsonic and Supersonic Regimes

    Czech Academy of Sciences Publication Activity Database

    Jeništa, Jiří; Hrabovský, Milan; Nishiyama, H.; Takana, H.; Bartlová, M.; Aubrecht, V.

    2010-01-01

    Roč. 14, č. 1 (2010), s. 63-76 ISSN 1093-3611 R&D Projects: GA ČR GA202/08/1084 Institutional research plan: CEZ:AV0Z20430508 Keywords : argon mass flow rate * divergence of radiation flux * partial characteristics * reabsorption * shock diamonds * water plasma torch Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 0.189, year: 2010

  11. Broadband Ftmw Spectroscopy of the Urea-Argon and Thiourea-Argon Complexes

    Science.gov (United States)

    Medcraft, Chris; Bittner, Dror M.; Cooper, Graham A.; Mullaney, John C.; Walker, Nick

    2017-06-01

    The rotational spectra complexes of argon-urea, argon-thiourea and water-thiourea have been measured by chirped-pulse Fourier transform microwave spectroscopy from 2-18.5 GHz. The sample was produced via laser vaporisation of a rod containing copper and the organic sample as a stream of argon was passed over the surface and subsequently expanded into the vacuum chamber cooling the sample. Argon was found to bind to π system of the carbonyl bond for both the urea and thiourea complexes.

  12. Negative corona current pulses in argon and in mixture argon with SF6

    International Nuclear Information System (INIS)

    Zahoranova, A.; Zahoran, M.; Bucek, A.; Cernak, M.; Bosko, J.

    2004-01-01

    Waveforms of the first negative current pulses in a short negative point-to plane gap in pure argon and argon with SF 6 admixture have been investigated with a nanosecond time resolution at a gas pressure 50 kPa as a function of applied gap voltage and content of SF 6 in the mixture. We have made an attempt to explain the differences in the discharge development in pure argon and in argon with admixture of SF 6 based on the observed changes of the pulse shape. The experimental results obtained will be discussed in context with existing computer simulation models (Authors)

  13. Heat Transfer During Evaporation of Cesium From Graphite Surface in an Argon Environment

    Directory of Open Access Journals (Sweden)

    Bespala Evgeny

    2016-01-01

    Full Text Available The article focuses on discussion of problem of graphite radioactive waste formation and accumulation. It is shown that irradiated nuclear graphite being inalienable part of uranium-graphite reactor may contain fission and activation products. Much attention is given to the process of formation of radioactive cesium on the graphite element surface. It is described a process of plasma decontamination of irradiated graphite in inert argon atmosphere. Quasi-one mathematical model is offered, it describes heat transfer process in graphite-cesium-argon system. Article shows results of calculation of temperature field inside the unit cell. Authors determined the factors which influence on temperature change.

  14. Characterization of weakly ionized argon flows for radio blackout mitigation experiments

    Science.gov (United States)

    Steffens, L.; Koch, U.; Esser, B.; Gülhan, A.

    2017-06-01

    For reproducing the so-called E × B communication blackout mitigation scheme inside the L2K arc heated facility of the DLR in weakly ionized argon §ows, a §at plate model has been equipped with a superconducting magnet, electrodes, and a setup comprising microwave plasma transmission spectroscopy (MPTS). A thorough characterization of the weakly ionized argon §ow has been performed including the use of microwave interferometry (MWI), Langmuir probe measurements, Pitot probe pro¦les, and spectroscopic methods like diode laser absorption spectroscopy (DLAS) and emission spectroscopy.

  15. Effect of N-acetylcysteine on the accuracy of the prothrombin time assay of plasma coagulation factor II+VII+X activity in subjects infused with the drug. Influence of time and temperature.

    Science.gov (United States)

    Thorsen, Sixtus; Teisner, Ane; Jensen, Søren Astrup; Philips, Malou; Dalhoff, Kim; Bendtsen, Flemming

    2009-01-01

    The prothrombin time (PT) assay of factor II+VII+X activity is an important predictor of liver damage in paracetamol poisoned patients. It complicates interpretation of results that the antidote, acetylcysteine (NAC) depresses this activity. The aim was to investigate if NAC influences the accuracy of the plasma PT assay. The accuracy of Nycotest PT was studied using plasma added NAC in vitro and plasma from subjects infused with NAC. The latter results were compared with those obtained by analysis of PT by CoaguChek S. Therapeutic NAC concentrations added to plasma in vitro decreased factor II+VII+X activity at 37 degrees C in a time-dependent manner. This effect was quenched at temperatures depression of factor II+VII+X activity in plasma from subjects infused with NAC during the first 3h of infusion indicating that it contained reactive NAC. The risk that this NAC interfered with the accuracy of the PT assay was considered minimal with samples stored below 24 degrees C. This was supported by similarity of results obtained by analysis of appropriately stored plasma and simultaneously drawn blood by CoaguChek S. Residual reactive NAC does not interfere with the accuracy of the PT assay of plasma stored below 24 degrees C, but NAC-induced loss in activity at 37 degrees C may be partly recovered during subsequent storage below 24 degrees C.

  16. Non-linear behaviour of power density and exposure time of argon laser on ocular tissues

    Energy Technology Data Exchange (ETDEWEB)

    El-Sayed, E M; Talaat, M S; Salem, E F [Physics Department, Faculty of Science, Ain Shams University, Cairo (Egypt)

    1997-12-31

    In ophthalmology, the thermal effect of argon laser is the most widely used category of laser- tissue interaction. The rise in tissue temperature has to exceed a threshold value for photo coagulation of retinal blood vessels. This value mainly depends on the laser. The most suitable argon laser power P and exposure time (t) which would be more effective for thermal and electrical behaviour of chicken eye was studied. This was achieved by measuring the variations in ocular temperature in electroretinogram (ERG) records under the effect of argon experiment, while power density (P) and exposure time (t) were varied in four different ways for each dose (pt). Results indicated that for the same laser dose, the temperature distribution of the eye, using low power density and high exposure time was higher than that high power density and low exposure time, indicating non-linearity of the laser dose. This finding was confirmed by ERG records which showed similar variations in b-wave latency, amplitude and duration, for the laser exposure conditions. This indicates variations in retinal function due to laser-dependent temperature variations. 5 figs., 3 tabs.

  17. Local effects of ECRH on argon transport at ASDEX upgrade

    International Nuclear Information System (INIS)

    Sertoli, Marco

    2010-01-01

    Future deuterium-tritium magnetically confined fusion power plants will most probably rely an high-Z Plasma Facing Components (PFCs) such as tungsten. This choice is determined by the necessity of low erosion of the first wall materials (to guarantee a long lifetime of the wall components) and by the need to avoid the too high tritium wall retention of typical carbon based PFCs. The experience gathered at the ASDEX Upgrade (AUG) tokamak has demonstrated the possibility of reliable and high performance plasma operation with a full tungsten-coated first wall. The observed accumulation of tungsten which can lead to excessive radiation losses is mitigated with the use of Electron Cyclotron Resonance Heating (ECRH). Although this impurity control method is routinely performed at AUG, the underlying physics principles are still not clear. This thesis aims an providing further knowledge an the effects of ECRH an the transport of impurities inside the core plasma. The transport of argon has been therefore investigated in-depth in purely ECR heated L-mode (low-confinement) discharges. Studies an impurity transport in centrally ECR heated nitrogen-seeded H-mode (high-confinement) discharges have also been performed. To this scope, a new crystal X-ray spectrometer of the Johann type has been installed an AUG for argon concentration and ion temperature measurements. New methods for the experimental determination of the total argon density through the integrated use of this diagnostic and of the Soft X-Ray (SXR) diode arrays have been developed. This gives the possibility of evaluating the full profiles of the argon transport coefficients from the linear flux-gradient dependency of local argon density. In comparison to classical χ 2 -minimization methods, the approach proposed here delivers transport coefficients intrinsically independent of the modelling of periodic relaxation mechanisms such as those Lied to sawtooth MHD (Magneto-Hydro-Dynamic) activity. Moreover, the good

  18. [Ratio of erythrocyte and plasma in massive blood transfusion].

    Science.gov (United States)

    Wen, Xian-Hui; Liu, Feng-Xia; Zhang, Jun-Hua; Gui, Rong

    2014-06-01

    This study was purposed to explore the suitable ratio between fresh frozen plasma and erythrocyte by retrospective analysis of coagulation in patients with massive blood transfusion. The clinical data of 151 cases with massive blood transfusion from January 2011 to January 2013 were analyzed retrospectively. According to coagulation, patients were divided into coagulation normal group (138 cases) and coagulation dysfunction group (13 cases). Based on the ratio of 1:1 of fresh frozen plasma and erythrocyte, the patients were divided into high plasma group(2:1), medium plasma group (1:1) and low plasma (blood transfusion. The results showed that prothrombin time (PT), activated partial thromboplastin time (APTT) and thrombin time (TT) were prolonged, fibrinogen (FIB) level decreased significantly (all P blood transfusion 24 h; the high plasma and the medium plasma group of coagulation normal group had no significant changes in coagulation (P > 0.05); prothrombin time, activated partial thromboplastin time, thrombin time and fibrinogen level in the medium plasma and low plasma subgroup of coagulation dysfunction group after massive transfusion was still in abnormal levels (P > 0.05), coagulation function in high plasma subgroup was improved significantly (P blood transfusion, the ratio between fresh frozen plasma and erythrocyte is recommended to be 2:1 in patients of coagulation dysfunction in order to improve the patient's coagulation function and to reduce the incidence of adverse event, the ratio of fresh frozen plasma to erythrocyte is recommended to be 1:1 in patients with normal coagulation so as to reduce the dilutional coagulopathy and hypervolemia of blood.

  19. [Coagulation factor VII levels in uremic patients and theirs influence factors].

    Science.gov (United States)

    Fang, Jun; Xia, Ling-Hui; Wei, Wen-Ning; Song, Shan-Jun

    2004-12-01

    This study was aimed to investigate coagulation factor VII level in uremic patients with chronic renal failure and to explore theirs influence factors. The plasma levels of coagulation factor VII were detected in 30 uremic patients with chronic renal failure before and after hemodialysis for 1 month, the factor VII activity (FVII:C) was determined by one-stage coagulation method, while activated factor VII (FVIIa) was measured by one-stage coagulation method using recombinant soluble tissue factor, and factor VII antigen was detected by ELISA. The results showed that: (1) The FVIIa, FVII:C and FVIIAg levels in chronic uremic patients before hemodialysis were 4.00 +/- 0.86 microg/L, (148.5 +/- 40.4)% and (99.8 +/- 21.1)% respectively, which were significantly increased, as compared with healthy controls [2.77 +/- 1.02 microg/L, (113.1 +/- 33.0)% and (73.7 +/- 18.3)% respectively, P factor VII was positively correlated with levels of blood uria nitrogen and serum creatinine before hemodialysis but not after hemodialysis. It is concluded that the enhanced levels of coagulation factor VII in chronic uremic patients suggested abnormal activated state, herperactivity and elevated production of factor VII which correlated with renal functional injury. The abnormality of factor VII in uremia may be aggravated by hemodialysis. Coagulation factor (FVII) may be a risk factor for cardiovascular events in uremic patients who especially had been accepted long-term hemodialysis.

  20. Investigation of coagulation activity of natural coagulants from seeds of different leguminose species

    Directory of Open Access Journals (Sweden)

    Šćiban Marina B.

    2005-01-01

    Full Text Available The ability of seeds of plants: Phaseolus vulgaris, Robinia pseudoacacia Ceratonia siliqua and Amorpha fruticosa, to act as natural coagulants was tested using synthetic turbid water. This water was prepared by adding kaolin into tap water, just before the test. Active components were extracted from ground seeds with distilled water. The coagulation ability of this extract was assessed by the use of standard jar test measurements in water with various initial turbidity. Investigation of these natural coagulants was confirmed their positive coagulation activity. Of all plants that have been examined, the seed extract from Ceratonia siliqua appeared to be one of the most effective coagulants for water treatment. A dose of 20 mg/l of this coagulant resulted in 100% coagulation activity for clarification of water with 17.5 NTU initial turbidity.

  1. Matriptase activation connects tissue factor-dependent coagulation initiation to epithelial proteolysis and signaling.

    Science.gov (United States)

    Le Gall, Sylvain M; Szabo, Roman; Lee, Melody; Kirchhofer, Daniel; Craik, Charles S; Bugge, Thomas H; Camerer, Eric

    2016-06-23

    The coagulation cascade is designed to sense tissue injury by physical separation of the membrane-anchored cofactor tissue factor (TF) from inactive precursors of coagulation proteases circulating in plasma. Once TF on epithelial and other extravascular cells is exposed to plasma, sequential activation of coagulation proteases coordinates hemostasis and contributes to host defense and tissue repair. Membrane-anchored serine proteases (MASPs) play critical roles in the development and homeostasis of epithelial barrier tissues; how MASPs are activated in mature epithelia is unknown. We here report that proteases of the extrinsic pathway of blood coagulation transactivate the MASP matriptase, thus connecting coagulation initiation to epithelial proteolysis and signaling. Exposure of TF-expressing cells to factors (F) VIIa and Xa triggered the conversion of latent pro-matriptase to an active protease, which in turn cleaved the pericellular substrates protease-activated receptor-2 (PAR2) and pro-urokinase. An activation pathway-selective PAR2 mutant resistant to direct cleavage by TF:FVIIa and FXa was activated by these proteases when cells co-expressed pro-matriptase, and matriptase transactivation was necessary for efficient cleavage and activation of wild-type PAR2 by physiological concentrations of TF:FVIIa and FXa. The coagulation initiation complex induced rapid and prolonged enhancement of the barrier function of epithelial monolayers that was dependent on matriptase transactivation and PAR2 signaling. These observations suggest that the coagulation cascade engages matriptase to help coordinate epithelial defense and repair programs after injury or infection, and that matriptase may contribute to TF-driven pathogenesis in cancer and inflammation.

  2. Development of Coagulation Factor Probes for the Identification of Procoagulant Circulating Tumor Cells

    Energy Technology Data Exchange (ETDEWEB)

    Tormoen, Garth W.; Cianchetti, Flor A. [Department of Biomedical Engineering, Oregon Health and Science University, Portland, OR (United States); Bock, Paul E. [Department of Pathology, Microbiology and Immunology, Vanderbilt University School of Medicine, Nashville, TN (United States); McCarty, Owen J. T., E-mail: tormoeng@ohsu.edu [Department of Biomedical Engineering, Oregon Health and Science University, Portland, OR (United States); Department of Cell and Developmental Biology, Oregon Health and Science University, Portland, OR (United States); Division of Hematology and Medical Oncology, Department of Medicine, Oregon Health and Science University, Portland, OR (United States)

    2012-09-06

    Metastatic cancer is associated with a hypercoagulable state, and pathological venous thromboembolic disease is a significant source of morbidity and the second leading cause of death in patients with cancer. Here we aimed to develop a novel labeling strategy to detect and quantify procoagulant circulating tumor cells (CTCs) from patients with metastatic cancer. We hypothesize that the enumeration of procoagulant CTCs may be prognostic for the development of venous thrombosis in patients with cancer. Our approach is based on the observation that cancer cells are capable of initiating and facilitating cell-mediated coagulation in vitro, whereby activated coagulation factor complexes assemble upon cancer cell membrane surfaces. Binding of fluorescently labeled, active site-inhibited coagulation factors VIIa, Xa, and IIa to the metastatic breast cancer cell line, MDA-MB-231, non-metastatic colorectal cell line, SW480, or metastatic colorectal cell line, SW620, was characterized in a purified system, in anticoagulated blood and plasma, and in plasma under conditions of coagulation. We conclude that a CTC labeling strategy that utilizes coagulation factor-based fluorescent probes may provide a functional assessment of the procoagulant potential of CTCs, and that this strategy is amenable to current CTC detection platforms.

  3. Investigation of the continuum radiation from a high pressure argon arc

    International Nuclear Information System (INIS)

    Glasser, J.; Chapelle, J.

    1975-01-01

    At the high electronic densities existing in high temperature strongly correlated plasmas (with number of electrons in the Debye sphere Nd<<1) it is sometimes difficult to find lines for which Stark broadening allows determination of electronic density. Since the broadening effect is rather strong, the lines overlap or could not be easily extracted from the intense continuous background. The continuum emission in the UV, visible and near infra-red regions, principally due to the radiative recombination, could thus be widely used for the diagnostics of such plasmas. So far a limited number of data on the continuum emission of Argon plasma is available. At the same time certain discrepancies between theoretical predictions and experiments have also been found. The aim of this work is to obtain more elaborated data on the Argon continuum emission at high pressure, where the differences were found to be the largest. (Auth.)

  4. Gas injected washer plasma gun

    International Nuclear Information System (INIS)

    Jain, K.K.; John, P.I.; Punithavelu, A.M.; Rao, P.P.

    1980-01-01

    A plasma gun similar in geometry to the washer plasma gun has been operated with gas injected externally. hydrogen, nitrogen and argon plasmas have been ionised and accelerated to velocities of the order of 10 7 mm s -1 and densities 10 11 mm -3 . Higher parameter range is possible with higher electrical input power. (author)

  5. Process of coagulating asphalts, etc

    Energy Technology Data Exchange (ETDEWEB)

    Schaeffer, J A; Pfersch, G

    1931-03-28

    The present invention has for its object a process of deasphaltizing and deparaffining applicable to mixtures of hydrocarbons such as crude mineral oils and tars obtained under the influence of heat from shales, lignites, peats, and similar products, to natural bitumens and those obtained by extraction with organic solvents and also all those derived from the substances, the process in question having the following characteristics: the coagulation or the precipitation of the asphaltic material, the resinous material, and the asphaltic and resinous material, which is found in the colloidal state or any other state in the substances given above, is obtained by the addition of a small amount of solvent and of acids or mixtures of acids.

  6. Plasma Processing of Metallic and Semiconductor Thin Films in the Fisk Plasma Source

    Science.gov (United States)

    Lampkin, Gregory; Thomas, Edward, Jr.; Watson, Michael; Wallace, Kent; Chen, Henry; Burger, Arnold

    1998-01-01

    The use of plasmas to process materials has become widespread throughout the semiconductor industry. Plasmas are used to modify the morphology and chemistry of surfaces. We report on initial plasma processing experiments using the Fisk Plasma Source. Metallic and semiconductor thin films deposited on a silicon substrate have been exposed to argon plasmas. Results of microscopy and chemical analyses of processed materials are presented.

  7. Trapping cold ground state argon atoms.

    Science.gov (United States)

    Edmunds, P D; Barker, P F

    2014-10-31

    We trap cold, ground state argon atoms in a deep optical dipole trap produced by a buildup cavity. The atoms, which are a general source for the sympathetic cooling of molecules, are loaded in the trap by quenching them from a cloud of laser-cooled metastable argon atoms. Although the ground state atoms cannot be directly probed, we detect them by observing the collisional loss of cotrapped metastable argon atoms and determine an elastic cross section. Using a type of parametric loss spectroscopy we also determine the polarizability of the metastable 4s[3/2](2) state to be (7.3±1.1)×10(-39)  C m(2)/V. Finally, Penning and associative losses of metastable atoms in the absence of light assisted collisions, are determined to be (3.3±0.8)×10(-10)  cm(3) s(-1).

  8. Sodium evaporation into a forced argon flow

    International Nuclear Information System (INIS)

    Kumada, Toshiaki; Kasahara, Fumio; Ishiguro, Ryoji

    1975-01-01

    Evaporation from a rectangular sodium free surface into an argon flow was measured. Tests were carried out with varying sodium temperature, argon velocity and argon temperature respectively under conditions of fog formation being possible. In order to clarify the enhancement of evaporation by fog formation, convection heat transfer from a plate of the same geometry into an air flow was also measured. The evaporation rate and Sherwood number were compared with those predicted by both the heat transfer experiment and the theory proposed by Hill and Szekely, and also a comparison was run with the previously reported experimental results of sodium evaporation. As a result it was shown that the sodium evaporation rate in this experiment is at least four times as large as that predicted by the heat transfer experiment and varies almost linearly with the heat transfer rate and the sodium vapour pressure. (auth.)

  9. Optical emission spectrometric determination of arsenic and antimony by continuous flow chemical hydride generation and a miniaturized microwave microstrip argon plasma operated inside a capillary channel in a sapphire wafer

    International Nuclear Information System (INIS)

    Pohl, Pawel; Zapata, Israel Jimenez; Bings, Nicolas H.; Voges, Edgar; Broekaert, Jose A.C.

    2007-01-01

    Continuous flow chemical hydride generation coupled directly to a 40 W, atmospheric pressure, 2.45 GHz microwave microstrip Ar plasma operated inside a capillary channel in a sapphire wafer has been optimized for the emission spectrometric determination of As and Sb. The effect of the NaBH 4 concentration, the concentration of HCl, HNO 3 and H 2 SO 4 used for sample acidification, the Ar flow rate, the reagent flow rates, the liquid volume in the separator as well as the presence of interfering metals such as Fe, Cu, Ni, Co, Zn, Cd, Mn, Pb and Cr, was investigated in detail. A considerable influence of Fe(III) (enhancement of up to 50 %) for As(V) and of Fe(III), Cu(II) and Cr(III) (suppression of up to 75%) as well as of Cd(II) and Mn(II) (suppression by up to 25%) for Sb(III) was found to occur, which did not change by more than a factor of 2 in the concentration range of 2-20 μg ml -1 . The microstrip plasma tolerated the introduction of 4.2 ml min -1 of H 2 in the Ar working gas, which corresponded to an H 2 /Ar ratio of 28%. Under these conditions, the excitation temperature as measured with Ar atom lines and the electron number density as determined from the Stark broadening of the H β line was of the order of 5500 K and 1.50 . 10 14 cm -3 , respectively. Detection limits (3σ) of 18 ng ml -1 for As and 31 ng ml -1 for Sb were found and the calibration curves were linear over 2 orders of magnitude. With the procedure developed As and Sb could be determined at the 45 and 6.4 μg ml -1 level in a galvanic bath solution containing 2.5% of NiSO 4 . Additionally, As was determined in a coal fly ash reference material (NIST SRM 1633a) with a certified concentration of As of 145 ± 15 μg g -1 and a value of 144 ± 4 μg g -1 was found

  10. Two-photon excitation of argon

    International Nuclear Information System (INIS)

    Pindzola, P.S.; Payne, M.C.

    1982-01-01

    The authors calculate two photon excitation parameters for various excited states of argon assuming the absorption of near resonance broad-bandwidth laser radiation. Results are given for the case of two photons absorbed for the same laser beam as well as the case of absorbing photons of different frequency from each of two laser beams. The authors use multiconfiguration Hartree-Fock wave functions to evaluate the second-order sums over matrix elements. Various experimental laser schemes are suggested for the efficient excitation and subsequent ionization of argon

  11. Argon isotopes as recorders of magmatic processes

    Science.gov (United States)

    Layer, P. W.; Gardner, J. E.; Mora Chaparro, J. C.; Arce, J. L.

    2003-12-01

    Argon isotopic ratios vary enough between different reservoirs (atmosphere, crust, mantle) and diffuse fast enough through most minerals at magmatic temperatures (700-1200 C) to make them ideal for looking at magma chamber dynamics. Indeed, diffusion is sufficiently fast to allow short time scales to be deciphered, setting argon apart from many other isotopic methods. A mineral's ability to retain "excess" argon (40Ar/36Ar ratios greater than the atmospheric value and apparent ages older than the known eruption age) during post-eruption cooling is key to Ar studies. Previous work shows that both phenocrysts (crystallizing in the magma chamber; e.g. Mt St. Helens; Layer and Gardner, 2001) and xenocrysts (introduced into the magma chamber; e.g Toba; Gardner et al., 2002) preserve excess argon, which enables magma chamber processes to be deciphered through the variable diffusion rates between crystal phases. Single crystal 40Ar/39Ar step-heating of biotite from the 10.5 ka eruption of Nevado de Toluca volcano, Mexico indicates that they are xenocrystic and resided for only a short (< 1 year) time in the magma before it erupted. The biotite has reaction rims of hornblende, orthopyroxene and plagioclase, and failed to grow experimentally at pressure-temperature conditions of the magma, confirming the xenocrystic nature of this phase. Single-step fusion of plagioclase phenocrysts from eruptions of El Chichon volcano, Mexico, shows evidence of excess (mantle) argon, whereas hornblende from the same eruptions contains little or none. In this case, faster diffusion of Ar in plagioclase than in hornblende allow plagioclase to incorporate excess argon during magma recharge; hornblende does not. Combining such results with other isotopic systems may in fact better determine magma chamber processes. At El Chichon, Sr isotopes suggest magma recharges ocurred (Tepley et al., 2000), whereas the argon isotopes suggest such pulses occurred just before each eruption. The fast and

  12. Effect of N-acetylcysteine on the accuracy of the prothrombin time assay of plasma coagulation factor II+VII+X activity in subjects infused with the drug. Influence of time and temperature

    DEFF Research Database (Denmark)

    Thorsen, Sixtus; Teisner, Ane; Jensen, Søren Astrup

    2009-01-01

    OBJECTIVES: The prothrombin time (PT) assay of factor II+VII+X activity is an important predictor of liver damage in paracetamol poisoned patients. It complicates interpretation of results that the antidote, acetylcysteine (NAC) depresses this activity. The aim was to investigate if NAC influences...... to plasma in vitro decreased factor II+VII+X activity at 37 degrees C in a time-dependent manner. This effect was quenched at temperatures ... to a significant additional depression of factor II+VII+X activity in plasma from subjects infused with NAC during the first 3h of infusion indicating that it contained reactive NAC. The risk that this NAC interfered with the accuracy of the PT assay was considered minimal with samples stored below 24 degrees C...

  13. Effect of N-acetylcysteine on the accuracy of the prothrombin time assay of plasma coagulation factor II plus VII plus X activity in subjects infused with the drug. Influence of time and temperature

    DEFF Research Database (Denmark)

    Thorsen, S.; Teisner, A.; Jensen, S.A.

    2009-01-01

    Objectives: The prothrombin time (PT) assay of factor II+VII+X activity is an important predictor of liver damage in paracetamol poisoned patients. It complicates interpretation of results that the antidote, acetylcysteine (NAC) depresses this activity. The aim was to investigate if NAC influences...... added to plasma in vitro decreased factor II+VII+X activity at 37 degrees C in a time-dependent manner. This effect was quenched at temperatures 24 degrees C. Activity lost at 37 degrees C could partly be recovered by subsequent incubation at 5 or 20 degrees C. Incubation at 37 degrees C prior to assay...... led to a significant additional depression of factor II+VII+X activity in plasma from subjects infused with NAC during the first 3h of infusion indicating that it contained reactive NAC. The risk that this NAC interfered with the accuracy of the PT assay was considered minimal with samples stored...

  14. Dusty plasmas

    International Nuclear Information System (INIS)

    Jones, M.E.; Winske, D.; Keinigs, R.; Lemons, D.

    1996-01-01

    This is the final report of a three-year, Laboratory-Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). The objective of this project has been to develop a fundamental understanding of dusty plasmas at the Laboratory. While dusty plasmas are found in space in galactic clouds, planetary rings, and cometary tails, and as contaminants in plasma enhanced fabrication of microelectronics, many of their properties are only partially understood. Our work has involved both theoretical analysis and self-consistent plasma simulations to understand basic properties of dusty plasmas related to equilibrium, stability, and transport. Such an understanding can improve the control and elimination of plasma dust in industrial applications and may be important in the study of planetary rings and comet dust tails. We have applied our techniques to the study of charging, dynamics, and coagulation of contaminants in plasma processing reactors for industrial etching and deposition processes and to instabilities in planetary rings and other space plasma environments. The work performed in this project has application to plasma kinetics, transport, and other classical elementary processes in plasmas as well as to plasma waves, oscillations, and instabilities

  15. Removal of silver nanoparticles by coagulation processes

    International Nuclear Information System (INIS)

    Sun, Qian; Li, Yan; Tang, Ting; Yuan, Zhihua; Yu, Chang-Ping

    2013-01-01

    Highlights: • This study investigated the removal of AgNP suspensions by four regular coagulants. • The optimal removal efficiencies for the four coagulants were achieved at pH 7.5. • The removal efficiency of AgNPs was affected by the natural water characteristics. • TEM and XRD showed that AgNPs or silver-containing NPs were adsorbed onto the flocs. -- Abstract: Commercial use of silver nanoparticles (AgNPs) will lead to a potential route for human exposure via potable water. Coagulation followed by sedimentation, as a conventional technique in the drinking water treatment facilities, may become an important barrier to prevent human from AgNP exposures. This study investigated the removal of AgNP suspensions by four regular coagulants. In the aluminum sulfate and ferric chloride coagulation systems, the water parameters slightly affected the AgNP removal. However, in the poly aluminum chloride and polyferric sulfate coagulation systems, the optimal removal efficiencies were achieved at pH 7.5, while higher or lower of pH could reduce the AgNP removal. Besides, the increasing natural organic matter (NOM) would reduce the AgNP removal, while Ca 2+ and suspended solids concentrations would also affect the AgNP removal. In addition, results from the transmission electron microscopy and X-ray diffraction showed AgNPs or silver-containing nanoparticles were adsorbed onto the flocs. Finally, natural water samples were used to validate AgNP removal by coagulation. This study suggests that in the case of release of AgNPs into the source water, the traditional water treatment process, coagulation/sedimentation, can remove AgNPs and minimize the silver ion concentration under the well-optimized conditions

  16. Emergent self-similarity of cluster coagulation

    Science.gov (United States)

    Pushkin, Dmtiri O.

    A wide variety of nonequilibrium processes, such as coagulation of colloidal particles, aggregation of bacteria into colonies, coalescence of rain drops, bond formation between polymerization sites, and formation of planetesimals, fall under the rubric of cluster coagulation. We predict emergence of self-similar behavior in such systems when they are 'forced' by an external source of the smallest particles. The corresponding self-similar coagulation spectra prove to be power laws. Starting from the classical Smoluchowski coagulation equation, we identify the conditions required for emergence of self-similarity and show that the power-law exponent value for a particular coagulation mechanism depends on the homogeneity index of the corresponding coagulation kernel only. Next, we consider the current wave of mergers of large American banks as an 'unorthodox' application of coagulation theory. We predict that the bank size distribution has propensity to become a power law, and verify our prediction in a statistical study of the available economical data. We conclude this chapter by discussing economically significant phenomenon of capital condensation and predicting emergence of power-law distributions in other economical and social data. Finally, we turn to apparent semblance between cluster coagulation and turbulence and conclude that it is not accidental: both of these processes are instances of nonlinear cascades. This class of processes also includes river network formation models, certain force-chain models in granular mechanics, fragmentation due to collisional cascades, percolation, and growing random networks. We characterize a particular cascade by three indicies and show that the resulting power-law spectrum exponent depends on the indicies values only. The ensuing algebraic formula is remarkable for its simplicity.

  17. Blood coagulation abnormalities in multibacillary leprosy patients.

    Science.gov (United States)

    Silva, Débora Santos da; Teixeira, Lisandra Antonia Castro; Beghini, Daniela Gois; Ferreira, André Teixeira da Silva; Pinho, Márcia de Berredo Moreira; Rosa, Patricia Sammarco; Ribeiro, Marli Rambaldi; Freire, Monica Di Calafiori; Hacker, Mariana Andrea; Nery, José Augusto da Costa; Pessolani, Maria Cristina Vidal; Tovar, Ana Maria Freire; Sarno, Euzenir Nunes; Perales, Jonas; Bozza, Fernando Augusto; Esquenazi, Danuza; Monteiro, Robson Queiroz; Lara, Flavio Alves

    2018-03-01

    Leprosy is a chronic dermato-neurological disease caused by Mycobacterium leprae infection. In 2016, more than 200,000 new cases of leprosy were detected around the world, representing the most frequent cause of infectious irreversible deformities and disabilities. In the present work, we demonstrate a consistent procoagulant profile on 40 reactional and non-reactional multibacillary leprosy patients. A retrospective analysis in search of signs of coagulation abnormalities among 638 leprosy patients identified 35 leprosy patients (5.48%) which displayed a characteristic lipid-like clot formed between blood clot and serum during serum harvesting, herein named 'leprosum clot'. Most of these patients (n = 16, 45.7%) belonged to the lepromatous leprosy pole of the disease. In addition, formation of the leprosum clot was directly correlated with increased plasma levels of soluble tissue factor and von Willebrand factor. High performance thin layer chromatography demonstrated a high content of neutral lipids in the leprosum clot, and proteomic analysis demonstrated that the leprosum clot presented in these patients is highly enriched in fibrin. Remarkably, differential 2D-proteomics analysis between leprosum clots and control clots identified two proteins present only in leprosy patients clots: complement component 3 and 4 and inter-alpha-trypsin inhibitor family heavy chain-related protein (IHRP). In agreement with those observations we demonstrated that M. leprae induces hepatocytes release of IHRP in vitro. We demonstrated that leprosy MB patients develop a procoagulant status due to high levels of plasmatic fibrinogen, anti-cardiolipin antibodies, von Willebrand factor and soluble tissue factor. We propose that some of these components, fibrinogen for example, presents potential as predictive biomarkers of leprosy reactions, generating tools for earlier diagnosis and treatment of these events.

  18. Blood coagulation abnormalities in multibacillary leprosy patients.

    Directory of Open Access Journals (Sweden)

    Débora Santos da Silva

    2018-03-01

    Full Text Available Leprosy is a chronic dermato-neurological disease caused by Mycobacterium leprae infection. In 2016, more than 200,000 new cases of leprosy were detected around the world, representing the most frequent cause of infectious irreversible deformities and disabilities.In the present work, we demonstrate a consistent procoagulant profile on 40 reactional and non-reactional multibacillary leprosy patients. A retrospective analysis in search of signs of coagulation abnormalities among 638 leprosy patients identified 35 leprosy patients (5.48% which displayed a characteristic lipid-like clot formed between blood clot and serum during serum harvesting, herein named 'leprosum clot'. Most of these patients (n = 16, 45.7% belonged to the lepromatous leprosy pole of the disease. In addition, formation of the leprosum clot was directly correlated with increased plasma levels of soluble tissue factor and von Willebrand factor. High performance thin layer chromatography demonstrated a high content of neutral lipids in the leprosum clot, and proteomic analysis demonstrated that the leprosum clot presented in these patients is highly enriched in fibrin. Remarkably, differential 2D-proteomics analysis between leprosum clots and control clots identified two proteins present only in leprosy patients clots: complement component 3 and 4 and inter-alpha-trypsin inhibitor family heavy chain-related protein (IHRP. In agreement with those observations we demonstrated that M. leprae induces hepatocytes release of IHRP in vitro.We demonstrated that leprosy MB patients develop a procoagulant status due to high levels of plasmatic fibrinogen, anti-cardiolipin antibodies, von Willebrand factor and soluble tissue factor. We propose that some of these components, fibrinogen for example, presents potential as predictive biomarkers of leprosy reactions, generating tools for earlier diagnosis and treatment of these events.

  19. Normal saline influences coagulation and endothelial function after traumatic brain injury and hemorrhagic shock in pigs

    DEFF Research Database (Denmark)

    Dekker, Simone E; Sillesen, Martin; Bambakidis, Ted

    2014-01-01

    ), colloids (Hextend [HEX]), and fresh frozen plasma (FFP) resuscitation are associated with differential effects on coagulation and endothelial systems. METHODS: We subjected 15 Yorkshire swine to TBI and HS (40% blood volume), and kept in HS for 2 hours before resuscitation with NS, HEX, or FFP. Markers......BACKGROUND: Traumatic brain injury (TBI) and hemorrhagic shock (HS) are the leading causes of trauma-related deaths. These insults disrupt coagulation and endothelial systems. This study investigated whether previously reported differences in lesion size and brain swelling during normal saline (NS...... of endothelial activation (E-selectin, Intercellular adhesion molecule [ICAM]-1), coagulation activation (prothrombin fragment 1 + 2), and natural anticoagulation (activated protein C [aPC]) were determined in serum and brain whole cell lysates. RESULTS: Serum levels of aPC were greater in the NS group (203 ± 30...

  20. Contraction ionization waves in the argon contracted discharge

    International Nuclear Information System (INIS)

    Golubovskij, Yu.B.; Kulikov, V.V.; Nekutchaev, V.O.

    1985-01-01

    An investigation of ionization waves in the argon contracted discharge and a definition of their arising propagation mechanism accounting for the specificity of elementary pocesses characteristic of argon are presented. (author)

  1. Silicon compounds of neon and argon

    Czech Academy of Sciences Publication Activity Database

    Roithová, J.; Schröder, Detlef

    -, č. 46 (2009), s. 8788-8790 ISSN 1433-7851 R&D Projects: GA ČR GA203/09/1223 Grant - others: ERC (XE) Adg HORIZOMS Institutional research plan: CEZ:AV0Z40550506 Keywords : argon * bond formation * dications * neon Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 11.829, year: 2009

  2. Performance of a uranium liquid argon calorimeter

    International Nuclear Information System (INIS)

    Tuts, P.M.

    1987-01-01

    The author presents results on the performance of a uranium and liquid argon colorimeter in the NW test beam at Fermilab. This study describes the calorimeter, and discusses its performance with electrons, pions and muons from 10 GeV to 150 GeV. The performance parameters measure response, linearity, resolution, compensation, and e/π separation

  3. SLD liquid argon calorimeter prototype test results

    International Nuclear Information System (INIS)

    Dubois, R.; Eigen, G.; Au, Y.

    1985-10-01

    The results of the SLD test beam program for the selection of a calorimeter radiator composition within a liquid argon system are described, with emphasis on the study of the use of uranium to obtain equalization of pion and electron responses

  4. Commissioning of the ATLAS Liquid Argon Calorimeters

    CERN Document Server

    Cooke, Mark S

    2009-01-01

    A selection of ATLAS liquid argon (LAr) calorimeter commissioning studies are presented. These include a coherent noise study, a measurement of the quality of the physics pulse shape prediction, and energy and time reconstruction analyses with cosmic and single beam signals.

  5. Thermal decomposition of barium valerate in argon

    DEFF Research Database (Denmark)

    Torres, P.; Norby, Poul; Grivel, Jean-Claude

    2015-01-01

    The thermal decomposition of barium valerate (Ba(C4H9CO2)(2)/Ba-pentanoate) was studied in argon by means of thermogravimetry, differential thermal analysis, IR-spectroscopy, X-ray diffraction and hot-stage optical microscopy. Melting takes place in two different steps, at 200 degrees C and 280...

  6. Dynamic behaviour of dc double anode plasma torch at atmospheric pressure

    International Nuclear Information System (INIS)

    Tu, X; Cheron, B G; Yan, J H; Cen, K F

    2007-01-01

    An original dc double anode plasma torch which provides a long-time and highly stable atmospheric plasma jet has been devised for the purpose of hazardous waste treatment. The arc fluctuations and dynamic behaviour of the argon and argon-nitrogen plasma jets under different operating conditions have been investigated by means of classical tools, such as the statistic method, fast Fourier transform (FFT) and correlation analysis. In our experiments, the takeover mode is identified as the fluctuation characteristic of the argon plasma jet while the restrike mode is typical in the argon-nitrogen plasma dynamic behaviour. In the case of pure argon, the FFT and correlation calculation results of electrical signals exhibit the only characteristic frequency of 150 Hz, which originates from the torch power and is independent of any change in the operating conditions. It indicates that the nature of fluctuations in an argon plasma jet is mainly induced by the undulation of the tri-phase rectified power supply. In contrast, besides the same low frequency bulk fluctuation, the dynamic behaviour of the argon-nitrogen plasma jet at high frequency (4.1 kHz) is ascribed to the rapid motion of both arc roots on the anode surface. In addition, it is found that each arc root attachment is rather diffused than located at a fixed position on the anode wall in the argon plasma jet, while constricted arc roots occur when nitrogen is added into argon as the plasma working gas

  7. Blood coagulation factor XII drives adaptive immunity during neuroinflammation via CD87-mediated modulation of dendritic cells

    Science.gov (United States)

    Göbel, Kerstin; Pankratz, Susann; Asaridou, Chloi-Magdalini; Herrmann, Alexander M.; Bittner, Stefan; Merker, Monika; Ruck, Tobias; Glumm, Sarah; Langhauser, Friederike; Kraft, Peter; Krug, Thorsten F.; Breuer, Johanna; Herold, Martin; Gross, Catharina C.; Beckmann, Denise; Korb-Pap, Adelheid; Schuhmann, Michael K.; Kuerten, Stefanie; Mitroulis, Ioannis; Ruppert, Clemens; Nolte, Marc W.; Panousis, Con; Klotz, Luisa; Kehrel, Beate; Korn, Thomas; Langer, Harald F.; Pap, Thomas; Nieswandt, Bernhard; Wiendl, Heinz; Chavakis, Triantafyllos; Kleinschnitz, Christoph; Meuth, Sven G.

    2016-01-01

    Aberrant immune responses represent the underlying cause of central nervous system (CNS) autoimmunity, including multiple sclerosis (MS). Recent evidence implicated the crosstalk between coagulation and immunity in CNS autoimmunity. Here we identify coagulation factor XII (FXII), the initiator of the intrinsic coagulation cascade and the kallikrein–kinin system, as a specific immune cell modulator. High levels of FXII activity are present in the plasma of MS patients during relapse. Deficiency or pharmacologic blockade of FXII renders mice less susceptible to experimental autoimmune encephalomyelitis (a model of MS) and is accompanied by reduced numbers of interleukin-17A-producing T cells. Immune activation by FXII is mediated by dendritic cells in a CD87-dependent manner and involves alterations in intracellular cyclic AMP formation. Our study demonstrates that a member of the plasmatic coagulation cascade is a key mediator of autoimmunity. FXII inhibition may provide a strategy to combat MS and other immune-related disorders. PMID:27188843

  8. Nanoparticles and the blood coagulation system. Part I: benefits of nanotechnology.

    Science.gov (United States)

    Ilinskaya, Anna N; Dobrovolskaia, Marina A

    2013-05-01

    Nanotechnology is proven to provide certain benefits in drug delivery by improving solubility, increasing uptake to target sites and changing pharmacokinetics profiles of traditional drugs. Since properties of many materials change tremendously at the nanoscale levels, nanotechnology is also being explored in various industrial applications. As such, nanoparticles are rapidly entering various areas of industry, biology and medicine. The benefits of using nanotechnology for industrial and biomedical applications are often tempered by concerns about the safety of these new materials. One such area of concern includes their effect on the immune system. While nanoparticle interactions with various constituents of the immune system have been reviewed before, little attention was given to nanoparticle effects on the blood coagulation system. Nanoparticle interface with the blood coagulation system may lead to either benefits to the host or adverse reactions. This article reviews recent advances in our understanding of nanoparticle interactions with plasma coagulation factors, platelets, endothelial cells and leukocytes. Part I is focused on desirable interactions between nanoparticles and the coagulation system, and discusses benefits of using nanotechnology to intervene in coagulation disorders. Undesirable interactions posing safety concerns are covered in part II, which will be published in the June issue of Nanomedicine.

  9. Blood coagulation and fibrinolysis of the whole-body irradiated rabbits

    International Nuclear Information System (INIS)

    Hishikawa-Itoh, Youko; Ayakawa, Yoshio; Miyata, Nobuki

    1984-01-01

    To study the effects of irradiation on blood coagulation and fibrinolysis, rabbits were irradiated with 60 Co γ-rays (whole-body: 0, 100, 400, 800, 1200 rads). Clotting time, activity of plasmin and plasminogen, and fibrinogen contents of irradiated rabbit plasma were measured at 4 days before, immediately after, and at 1, 3, 7, 10, and 14 days after irradiation. Both clotting times obtained by addition of (kaolin+phospholipid) which expressed effects on the total intrinsic coagulation system, and by addition of (Ca 2+ ) which expressed effects on the total extrinsic coagulation system, were prolonged with small dose irradiation (100 rads) immediately and 3 days after irradiation. However, with high dose irradiation (400-1200 rads), these clotting times were prolonged 1 day after irradiation. The times of manifestation of irradiation effects on clotting time were different in small and high dose irradiation. Plasmin activity was decreased immediately, 1 day after and recovered 3 days after irradiation. Plasminogen activity was markedly increased in 800 and 1200 rads irradiated groups from 3 days after irradiation. Conversion of plasminogen into plasmin was impaired by irradiation. Fibrinogen contents increased rapidly in all irradiated rabbits except for 100 rads from 1 day after irradiation. These results revealed decreased coagulation and fibrinolysis activities in rabbit blood, irradiation injury of both coagulation and fibrinolysis activation systems, and accumulation of the precursors of fibrin and plasmin (i.e., fibrinogen and plasminogen). (author)

  10. Fast and interrupted expansion in cyclic void growth in dusty plasma

    International Nuclear Information System (INIS)

    Van de Wetering, F M J H; Brooimans, R J C; Nijdam, S; Beckers, J; Kroesen, G M W

    2015-01-01

    Low-pressure acetylene plasmas are able to spontaneously form dust particles. This will result in a dense cloud of solid particles that is levitated in the plasma. The formed particles can grow up to micrometers. We observed a spontaneous interruption in the expansion of the so-called dust void. A dust void is a macroscopic region in the plasma that is free of nanoparticles. The phenomenon is periodical and reproducible. We refer to the expansion interruption as ‘hiccup’. The expanding void is an environment in which a new cycle of dust particle formation can start. At a certain moment in time, this cycle reaches the (sudden) coagulation phase and as a result the void will temporarily shrink. To substantiate this reasoning, the electron density is determined non-intrusively using microwave cavity resonance spectroscopy. Moreover, video imaging of laser light scattering of the dust particles provides their spatial distribution. The emission intensity of a single argon transition is measured similarly. Our results support the aforementioned hypothesis for what happens during the void hiccup. The void dynamics preceding the hiccup are modeled using a simple analytical model for the two dominant forces (ion drag and electric) working on a nanoparticle in a plasma. The model results qualitatively reproduce the measurements. (paper)

  11. 46 CFR 151.50-36 - Argon or nitrogen.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false Argon or nitrogen. 151.50-36 Section 151.50-36 Shipping... BULK LIQUID HAZARDOUS MATERIAL CARGOES Special Requirements § 151.50-36 Argon or nitrogen. (a) A cargo tank that contains argon or nitrogen and that has a maximum allowable working pressure of 172 kPa (25...

  12. Peculiarities of spectroscopic determination of the isotopic hydrogen composition in a mixture with neon and argon

    International Nuclear Information System (INIS)

    Nemets, V.M.; Petrov, A.A.; Solov'ev, A.A.

    1987-01-01

    The dependence of the relative intensity of atomic lines of hydrogen isotopes in the mixture with neon and argon during excitation in a high-frequency discharge under medium and high pressures is investigated. A physical model is suggested for processes determining the isotopic effects in the atomic hydrogen spectrum due to isotopic differences in velocity constants of dissociation-association, transfer and ionic-molecular reactions in a gas discharge plasma

  13. Extreme ultraviolet spectroscopy of highly charged argon ions at the Berlin EBIT

    International Nuclear Information System (INIS)

    Biedermann, C; Radtke, R; Fussmann, G; Allen, F I

    2007-01-01

    Extreme ultraviolet radiation from highly charged argon was investigated at the Berlin Electron Beam Ion Trap with a 2 m grazing incidence spectrometer. Lines in the wavelength range 150 to 660 A originating from C-like Ar 12+ to Li-like Ar 15+ ions have been identified and are compared with database information from solar line lists and predictions. Line ratios for the observed resonance, intercombination and forbidden lines offer important diagnostic capabilities for low density, hot plasmas

  14. Hemorrhoidectomy: pedicle ligation vs pedicle coagulation

    International Nuclear Information System (INIS)

    Shaikh, B.S.; Balaoch, I.B.; Sohu, K.M.

    2015-01-01

    Objective: To compare the outcome of pedicle ligation vs pedicle coagulation haemorrhoidectomy. Methodology: This comparative prospective study was carried out at Department of Surgery, Ghulam Muhammad Maher Medcial College Hospital, Sukkur, Pakistan from January 2011 to January 2013 and included 300 patients of hemorrhoids. After routine workup, patients were randomly divided into two equal groups with one group receiving pedicle ligation and other pedicle coagulation for hemorrhoidectomy. Postoperatively they were followed for a period of 8 weeks for complications including pain, urinary retention, bleeding and anal stricture. Pain was recorded up to 10th postoperative day on the basis of visual analogue scale. Results: Mean age was 45 years and male to female ratio was 1.7:1. Mean operative time in pedicle ligation group was 15 min (range 14-20 min) and 17 min (15-25 min) in pedicle coagulation group. In Pedicle ligation group, pain was worst in 35 patients, moderate in 85 and mild in 30 patients; on the other hand in pedicle coagulation group, just 09 patients experienced worst pain. Urinary retention was observed in 44 patients in pedicle ligation group and 19 in pedicle coagulation group. Five patients in pedicle ligation group developed bleeding after their discharge from hospital; 7 patients in pedicle coagulation group reported secondary bleeding. Anal stricture was a rare complication and was found equally common in both the groups. Conclusion: Conventional hemorrhoidectomy with pedicle coagulation is an effective treatment modality for hemorrhoids and is associated with less chance of postoperative anal pain and urinary retention. (author)

  15. Coagulation abnormalities in patients with chronic liver disease in Pakistan

    International Nuclear Information System (INIS)

    Siddiqui, S.A.; Ghani, M.H.; Ghori, M.A.; Ahmed, M.

    2011-01-01

    Objective: To determine the coagulation abnormalities and relationship between abnormal clotting tests and the risk of gastrointestinal bleeding (GI) among chronic liver disease (CLD) patients admitted at a tertiary care hospital in Pakistan. Methods: Adult CLD patients admitted at Liaquat University Hospital Jamshoro, during Nov 2004 - Oct 2005, were included in the study. The patients blood were tested for coagulation abnormalities including prothrombin time (PT), activated partial thromboplastin time (aPTT), platelet count and plasma fibrinogen. Association was seen between the abnormal clotting tests and the gastrointestinal bleeding by calculating relative risk (RR) with 95% confidence interval. Results: PT was prolonged in 88% and aPTT was raised in 71% cases of CLD. Both PT and aPTT were prolonged in 67% CLD cases. Approximately 37% CLD cases had decreased platelet count and 15% cases had decreased serum fibrinogen level. Relative risk of GI bleeding with abnormal clotting tests in CLD cases were weakly positive for PT (RR = 1.02; 95% CI, 0.49-2.10), negative for aPTT (RR=0.83; 95% CI, 0.47-1.45), strongly positive for decreased platelet counts (RR = 1.96; 95% CI, 1.08-3.56) and also for decreased fibrinogen level (RR = 1.47; 95% CI, 0.64-3.35). Conclusion: Coagulation abnormalities were profound in CLD. Decrease platelet counts and fibrinogen levels were related with GI bleeding but PT and aPTT were not significantly related with GI bleeding in patients with chronic liver disease. Nevertheless, these parameters (PT and aPTT) were still used as prognostic markers. (author)

  16. Plasma metallization

    International Nuclear Information System (INIS)

    Crowther, J.M.

    1997-09-01

    Many methods are currently used for the production of thin metal films. However, all of these have drawbacks associated with them, for example the need for UHV conditions, high temperatures, exotic metal precursors, or the inability to coat complex shaped objects. Reduction of supported metal salts by non-isothermal plasma treatment does not suffer from these drawbacks. In order to produce and analyse metal films before they become contaminated, a plasma chamber which could be attached directly to a UHV chamber with XPS capability was designed and built. This allowed plasma treatment of supported metal salts and surface analysis by XPS to be performed without exposure of the metal film to the atmosphere. Non-equilibrium plasma treatment of Nylon 66 supported gold(lll) chloride using hydrogen as the feed gas resulted in a 95% pure gold film, the remaining 5% of the film being carbon. If argon or helium were used as the feed gases during plasma treatment the resultant gold films were 100% pure. Some degree of surface contamination of the films due to plasma treatment was observed but was easily removed by argon ion cleaning. Hydrogen plasma reduction of glass supported silver(l) nitrate and palladium(ll) acetate films reveals that this metallization technique is applicable to a wide variety of metal salts and supports, and has also shown the ability of plasma reduction to retain the complex 'fern-like' structures seen for spin coated silver(l) nitrate layers. Some metal salts are susceptible to decomposition by X-rays. The reduction of Nylon 66 supported gold(lll) chloride films by soft X-rays to produce nanoscopic gold particles has been studied. The spontaneous reduction of these X-ray irradiated support gold(lll) chloride films on exposure to the atmosphere to produce gold rich metallic films has also been reported. (author)

  17. Atmospheric pressure argon surface discharges propagated in long tubes: physical characterization and application to bio-decontamination

    International Nuclear Information System (INIS)

    Kovalova, Zuzana; Leroy, Magali; Jacobs, Carolyn; Kirkpatrick, Michael J; Odic, Emmanuel; Machala, Zdenko; Lopes, Filipa; Laux, Christophe O; DuBow, Michael S

    2015-01-01

    Pulsed corona discharges propagated in argon (or in argon with added water vapor) at atmospheric pressure on the interior surface of a 49 cm long quartz tube were investigated for the application of surface bio-decontamination. H 2 O molecule dissociation in the argon plasma generated reactive species (i.e. OH in ground and excited states) and UV emission, which both directly affected bacterial cells. In order to facilitate the evaluation of the contribution of UV radiation, a DNA damage repair defective bacterial strain, Escherichia coli DH-1, was used. Discharge characteristics, including propagation velocity and plasma temperature, were measured. Up to ∼5.5 and ∼5 log 10 reductions were observed for E. coli DH-1 bacteria (from 10 6 initial load) exposed 2 cm and 44 cm away from the charged electrode, respectively, for a 20 min plasma treatment. The factors contributing to the observed bactericidal effect include desiccation, reactive oxygen species (OH) plus H 2 O 2 accumulation in the liquid phase, and UV-B (and possibly VUV) emission in dry argon. The steady state temperature measured on the quartz tube wall did not exceeded 29 °C; the contribution of heating, along with that of H 2 O 2 accumulation, was estimated to be low. The effect of UV-B emission alone or in combination with the other stress factors of the plasma process was examined for different operating conditions. (paper)

  18. Preferential site occupancy observed in coexpanded argon-krypton clusters

    International Nuclear Information System (INIS)

    Lundwall, M.; Bergersen, H.; Lindblad, A.; Oehrwall, G.; Svensson, S.; Bjoerneholm, O.; Tchaplyguine, M.

    2006-01-01

    Free heterogeneous argon-krypton clusters have been produced by coexpansion and investigated by means of x-ray photoelectron spectroscopy. By examining cluster surface and bulk binding energy shifts, relative intensities, and peak widths, we show that in the mixed argon-krypton clusters the krypton atoms favor the bulk and argon atoms are pushed to the surface. Furthermore, we show that krypton atoms in the surface layer occupy high-coordination sites and that heterogeneous argon-krypton clusters produced by coexpansion show the same surface structure as argon host clusters doped with krypton. These observations are supported by site-dependent calculations of chemical shifts

  19. Disseminated intravascular coagulation caused by moojenactivase, a procoagulant snake venom metalloprotease.

    Science.gov (United States)

    Sartim, Marco A; Cezarette, Gabriel N; Jacob-Ferreira, Anna L; Frantz, Fabiani G; Faccioli, Lucia H; Sampaio, Suely V

    2017-10-01

    Snake venom toxins that activate coagulation factors are key players in the process of venom-induced coagulopathy, and account for severe clinical manifestations. The present study applies a variety of biochemical, hematological, and histopathological approaches to broadly investigate the intravascular and systemic effects of moojenactivase (MooA), the first described PIIId subclass metalloprotease isolated from Bothrops sp. venom that activates coagulation factors. MooA induced consumption coagulopathy with high toxic potency, characterized by prolongation of prothrombin and activated partial thromboplastin time, consumption of fibrinogen and the plasma coagulation factors X and II, and thrombocytopenia. MooA promoted leukocytosis and expression of the proinflammatory cytokines interleukin-6 and tumor necrosis factor-α, accompanied by tissue factor-dependent procoagulant activity in peripheral blood mononuclear cells. This metalloprotease also caused intravascular hemolysis, elevated plasma levels of creatine kinase-MB, aspartate transaminase, and urea/creatinine, and induced morphopathological alterations in erythrocytes, heart, kidney, and lungs associated with thrombosis and hemorrhage. Diagnosis of MooA-induced disseminated intravascular coagulation represents an important approach to better understand the pathophysiology of Bothrops envenomation and develop novel therapeutic strategies targeting hemostatic disturbances. Copyright © 2017. Published by Elsevier B.V.

  20. The effects of nanomaterials on blood coagulation in hemostasis and thrombosis.

    Science.gov (United States)

    Simak, Jan; De Paoli, Silvia

    2017-09-01

    The blood coagulation balance in the organism is achieved by the interaction of the blood platelets (PLTs) with the plasma coagulation system (PCS) and the vascular endothelial cells. In healthy organism, these systems prevent thrombosis and, in events of vascular damage, enable blood clotting to stop bleeding. The dysregulation of hemostasis may cause serious thrombotic and/or hemorrhagic pathologies. Numerous engineered nanomaterials are being investigated for biomedical purposes and are unavoidably exposed to the blood. Also, nanomaterials may access vascular system after occupational, environmental, or other types of exposure. Thus, it is essential to evaluate the effects of engineered nanomaterials on hemostasis. This review focuses on investigations of nanomaterial interactions with the blood components involved in blood coagulation: the PCS and PLTs. Particular emphases include the pathophysiology of effects of nanomaterials on the PCS, including the kallikrein-kinin system, and on PLTs. Methods for investigating these interactions are briefly described, and a review of the most important studies on the interactions of nanomaterials with plasma coagulation and platelets is provided. WIREs Nanomed Nanobiotechnol 2017, 9:e1448. doi: 10.1002/wnan.1448 For further resources related to this article, please visit the WIREs website. © Published 2017. This article is a U.S. Government work and is in the public domain in the USA.

  1. Magnetic particle imaging of blood coagulation

    Energy Technology Data Exchange (ETDEWEB)

    Murase, Kenya, E-mail: murase@sahs.med.osaka-u.ac.jp; Song, Ruixiao; Hiratsuka, Samu [Department of Medical Physics and Engineering, Division of Medical Technology and Science, Faculty of Health Science, Graduate School of Medicine, Osaka University, Osaka 565-0871 (Japan)

    2014-06-23

    We investigated the feasibility of visualizing blood coagulation using a system for magnetic particle imaging (MPI). A magnetic field-free line is generated using two opposing neodymium magnets and transverse images are reconstructed from the third-harmonic signals received by a gradiometer coil, using the maximum likelihood-expectation maximization algorithm. Our MPI system was used to image the blood coagulation induced by adding CaCl{sub 2} to whole sheep blood mixed with magnetic nanoparticles (MNPs). The “MPI value” was defined as the pixel value of the transverse image reconstructed from the third-harmonic signals. MPI values were significantly smaller for coagulated blood samples than those without coagulation. We confirmed the rationale of these results by calculating the third-harmonic signals for the measured viscosities of samples, with an assumption that the magnetization and particle size distribution of MNPs obey the Langevin equation and log-normal distribution, respectively. We concluded that MPI can be useful for visualizing blood coagulation.

  2. Coagulation management in patients undergoing neurosurgical procedures.

    Science.gov (United States)

    Robba, Chiara; Bertuetti, Rita; Rasulo, Frank; Bertuccio, Alessando; Matta, Basil

    2017-10-01

    Management of coagulation in neurosurgical procedures is challenging. In this contest, it is imperative to avoid further intracranial bleeding. Perioperative bleeding can be associated with a number of factors, including anticoagulant drugs and coagulation status but is also linked to the characteristic and the site of the intracranial disorder. The aim of this review will be to focus primarily on the new evidence regarding the management of coagulation in patients undergoing craniotomy for neurosurgical procedures. Antihemostatic and anticoagulant drugs have shown to be associated with perioperative bleeding. On the other hand, an increased risk of venous thromboembolism and hypercoagulative state after elective and emergency neurosurgery, in particular after brain tumor surgery, has been described in several patients. To balance the risk between thrombosis and bleeding, it is important to be familiar with the perioperative changes in coagulation and with the recent management guidelines for anticoagulated patients undergoing neurosurgical procedures, in particular for those taking new direct anticoagulants. We have considered the current clinical trials and literature regarding both safety and efficacy of deep venous thrombosis prophylaxis in the neurosurgical population. These were mainly trials concerning both elective surgical and intensive care patients with a poor grade intracranial bleed or multiple traumas with an associated severe traumatic brain injury (TBI). Coagulation management remains a major issue in patients undergoing neurosurgical procedures. However, in this field of research, literature quality is poor and further studies are necessary to identify the best strategies to minimize risks in this group of patients.

  3. Intraventricular hemorrhage in preterm infants and coagulation--ambivalent perspectives?

    Science.gov (United States)

    Kuperman, Amir A; Brenner, Benjamin; Kenet, Gili

    2013-01-01

    Intraventricular hemorrhage (IVH) is a major complication of preterm birth, and large hemorrhages may yield significant future disability. During the last few decades, the survival of preterm infants has increased dramatically. Nevertheless, morbidity is still a major problem especially for very young and extremely low birth weight infants. As both, mortality and incidence of morbidities known to influence outcome, show a weekly decline with increasing gestational age, prematurity and low birth weight have been identified as major risk factors for IVH occurrence. This stems probably from the increased vulnerability of the premature germinal matrix as well as the physiologically impaired hemostasis, demonstrated in neonates. The hypothesis that a severe coagulation deficiency in the premature newborn could be a major contributing factor for IVH has been suggested, and small open label interventional studies targeting the premature coagulation system have been conducted with ethamsylate, vitamin K, fresh frozen plasma, recombinant activated factor VII and prothrombin complex concentrate. Nevertheless, potential venous origin of hemorrhages, which may be related to thrombophilic risk factors, has also been discussed. The following manuscript will focus upon IVH pathogenesis and address potential therapies. Copyright © 2013 Elsevier Ltd. All rights reserved.

  4. Absorption and stimulated emission between the electronic states of C and C_2 radicals in an expanding thermal plasma

    NARCIS (Netherlands)

    Otorbaev, D.K.; Sanden, van de M.C.M.; Buuron, A.J.M.; Schram, D.C.

    1995-01-01

    Using the method of reabsorption the absolute densities of argon, atomic and molecular carbon are determined during the deposition of amorphous hydrogenated (diamond-like) carbon coatings by an expanding thermal are plasma. Depending on the gas mixture argon/methane or argon/acetylene and the manner

  5. ATLAS Liquid Argon Calorimeter Module Zero

    CERN Multimedia

    1993-01-01

    This module was built and tested with beam to validate the ATLAS electromagnetic calorimeter design. One original design feature is the folding. 10 000 lead plates and electrodes are folded into an accordion shape and immersed in liquid argon. As they cross the folds, particles are slowed down by the lead. As they collide with the lead atoms, electrons and photons are ejected. There is a knock-on effect and as they continue on into the argon, a whole shower is produced. The electrodes collect up all the electrons and this signal gives a measurement of the energy of the initial particle. The M0 was fabricated by French institutes (LAL, LAPP, Saclay, Jussieu) in the years 1993-1994. It was tested in the H6/H8 beam lines in 1994, leading to the Technical Design Report in 1996.

  6. Diffusion of lithium ions in argon

    International Nuclear Information System (INIS)

    Stefansson, T.

    1983-01-01

    Published measurements of transport coefficients for Li + ions in argon seem to be limited to the mobility and the longitudinal diffusion coefficient in the field-to-density ratio range at and below 200 Td 1-5 . In this paper results are presented from measurements of the transverse diffusion coefficient to mobility ratio (Dsub(T)/μ) for Li + ions in argon in the field-to-density ratio range 10 < E/n < 800 Td. The measurements were made with a drift tube mass spectrometer at a gas temperature of 295 +- 1 K using the modified Townsend method of Skullerud. The experimental curve is compared to a calculation by H.R. Skullerud in the same proceedings. (G.Q.)

  7. Argon laser irradiation of the otolithic organ

    Energy Technology Data Exchange (ETDEWEB)

    Okuno, T.; Nomura, Y.; Young, Y.H.; Hara, M. (Univ. of Tokyo (Japan))

    1990-12-01

    An argon laser was used to irradiate the otolithic organs of guinea pigs and cynomolgus monkeys. After stapedectomy, the argon laser (1.5 W x 0.5 sec/shot) irradiated the utricle or saccule without touching the sensory organs. The stapes was replaced over the oval window after irradiation. The animals used for acute observation were killed immediately for morphologic studies; those used for long-term observation were kept alive for 2, 4, or 10 weeks. Acute observation revealed that sensory and supporting cells were elevated from the basement membrane only in the irradiated area. No rupture of the membranous labyrinth was observed. Long-term observation revealed that the otolith of the macula utriculi had disappeared in 2-week specimens. The entire macula utricili had disappeared in 10-week specimens. No morphologic changes were observed in cochlea, semicircular canals, or membranous labyrinth. The saccule showed similar changes.

  8. Infrared coagulation: a new treatment for hemorrhoids

    International Nuclear Information System (INIS)

    Leicester, R.J.; Nicholls, R.J.; Mann, C.V.

    1981-01-01

    Many methods, which have effectively reduced the number of patients requiring hospital admission, have been described for the outpatient treatment of hemorrhoids. However, complications have been reported, and the methods are often associated with unpleasant side effects. In 1977 Neiger et al. described a new method that used infrared coagulation, which produced minimal side effects. The authors have conducted a prospective, randomized trial to evaluate infrared coagulation compared with more traditional methods of treatment. The authors' results show that it may be more effective than injection sclerotherapy in treating non-prolapsing hemorrhoids and that it compares favorably with rubber band ligation in most prolapsing hemorrhoids. No complications occurred, and significantly fewer patients experienced pain after infrared coagulation

  9. Effects on coagulation factor production following primary hepatomitogen-induced direct hyperplasia.

    Science.gov (United States)

    Tatsumi, Kohei; Ohashi, Kazuo; Taminishi, Sanae; Takagi, Soichi; Utoh, Rie; Yoshioka, Akira; Shima, Midori; Okano, Teruo

    2009-11-14

    To investigate the molecular mechanisms involved in coagulation factor expression and/or function during direct hyperplasia (DH)-mediated liver regeneration. Direct hyperplasia-mediated liver regeneration was induced in female C57BL/6 mice by administering 1,4-bis[2-(3,5-dichloropyridyloxy)] benzene (TCPOBOP), a representative hepatomitogen. Mice were weighed and sacrificed at various time points [Day 0 (D0: prior to injection), 3 h, D1, D2, D3, and D10] after TCPOBOP administration to obtain liver and blood samples. Using the RNA samples extracted from the liver, a comprehensive analysis was performed on the hepatic gene expression profiling of coagulation-related factors by real-time RT-PCR (fibrinogen, prothrombin, factors V, VII, VIII, IX, X, XI, XII, XIIIbeta, plasminogen, antithrombin, protein C, protein S, ADAMTS13, and VWF). The corresponding plasma levels of coagulation factors (fibrinogen, prothrombin, factors V, VII, VIII, IX, X, XI, XII, XIII, and VWF) were also analyzed and compared with their mRNA levels. Gavage administration of TCPOBOP (3 mg/kg body weight) resulted in a marked and gradual increase in the weight of the mouse livers relative to the total body weight to 220% by D10 relative to the D0 (control) ratios. At the peak of liver regeneration (D1 and D2), the gene expression levels for most of the coagulation-related factors (fibrinogen, prothrombin, factors V, VII, VIII, IX, XI, XII, XIIIbeta, plasminogen, antithrombin, protein C, ADAMTS13, VWF) were found to be down-regulated in a time-dependent manner, and gradually recovered by D10 to the basal levels. Only mRNA levels of factor X and protein S failed to show any decrease during the regenerative phase. As for the plasma levels, 5 clotting factors (prothrombin, factors VIII, IX, XI, and XII) demonstrated a significant decrease (Pfactors, factor IX and factor XI showed the most dramatic decline in their activities by about 50% at D2 compared to the basal levels, and these reductions in

  10. An updated concept of coagulation with clinical implications.

    Science.gov (United States)

    Romney, Gregory; Glick, Michael

    2009-05-01

    Over the past century, a series of models have been put forth to explain the coagulation mechanism. The coagulation cascade/waterfall model has gained the most widespread acceptance. This model, however, has problems when it is used in different clinical scenarios. A more recently proposed cell-based model better describes the coagulation process in vivo and provides oral health care professionals (OHCPs) with a better understanding of the clinical implications of providing dental care to patients with potentially increased bleeding tendencies. The authors conducted a literature search using the PubMed database. They searched for key words including "coagulation," "hemostasis," "bleeding," "coagulation factors," "models," "prothrombin time," "activated partial thromboplastin time," "international normalized ratio," "anticoagulation therapy" and "hemophilia" separately and in combination. The coagulation cascade/waterfall model is insufficient to explain coagulation in vivo, predict a patient's bleeding tendency, or correlate clinical outcomes with specific laboratory screening tests such as prothrombin time, activated partial thromboplastin time and international normalized ratio. However, the cell-based model of coagulation that reflects the in vivo process of coagulation provides insight into the clinical ramifications of treating dental patients with specific coagulation factor deficiencies. Understanding the in vivo coagulation process will help OHCPs better predict a patient's bleeding tendency. In addition, applying the theoretical concept of the cell-based model of coagulation to commonly used laboratory screening tests for coagulation and bleeding will result in safer and more appropriate dental care.

  11. The investigation of coagulation activity of natural coagulants extracted from different strains of common bean

    Directory of Open Access Journals (Sweden)

    Šćiban Marina B.

    2010-01-01

    Full Text Available Coagulation and flocculation by adding chemicals are the methods that are usually used for removal of water turbidity. This study is concerned with the coagulation activity of extracts of various strains of bean. The aim was to ascertain if bean varieties influence coagulation activity. Active components were extracted from 1 g of ground sample with 100 ml distilled water. Contents of dry matter and nitrogen were specified in the solid samples, and the content of soluble nitrogen was determined in the extracts. These data were used to calculate the efficiency of extraction of nitrogen-containing compounds. The coagulation activity was assessed by jar test using synthetic turbid water, of the initial pH 9 and turbidity 35 NTU. The jar test was carried out by adding different amounts of extracts to model water, and stirring the content. After sedimentation for 1 h, residual turbidity was determined by turbidimeter and coagulation activity was calculated. The increment of organic matter concentration after the coagulation was also determined. These experiments confirmed that extracts of all investigated strains of bean could be used successfully as natural coagulants.

  12. Detrapping of tungsten nanoparticles in a direct-current argon glow discharge

    Energy Technology Data Exchange (ETDEWEB)

    Couëdel, L., E-mail: lenaic.couedel@univ-amu.fr; Kumar, K. Kishor; Arnas, C. [Laboratoire de Physique des Interactions Ioniques et Moléculaires, CNRS, Aix-Marseille Université, 13397 Marseille (France)

    2014-12-15

    Nanoparticles are grown from the sputtering of a tungsten cathode in a direct current argon glow discharge. Laser light scattering of a vertical laser sheet going through the plasma reveals that the dust particle cloud is compressed and pushed towards the anode during the discharge. Scanning electron microscopy images of substrates exposed to the plasma for given durations show that dust particles are continuously falling down on the anode during the discharge. These observations are explained by the fact that the electrostatic force at the negative glow-anode sheath boundary cannot balance the ion drag, gravity, and thermophoresis forces for particles of more than a few tens of nanometres in diameter.

  13. Argon line broadening by neutral atoms and application to the measurement of oscillator strengths of AI resonance lines

    International Nuclear Information System (INIS)

    Vallee, O.; Ranson, P.; Chapelle, J.

    1977-01-01

    AI line broadening was studied from collisions between neutral argon atoms (3p 5 4p-3p 5 4s transitions) in a weakly ionised plasma jet (neutral atoms temperature T 0 approximately 4000K, electrons temperature Tsub(e) approximately 6000K, electronic density Nsub(e) 15 cm -3 , ionisation rate α -4 , and pressure range from 1 to 3 kg/cm 2 ). A satisfactory description of Van der Waals broadened lines is obtained by means of a Lennard-Jones potential. Measurement of line widths whose corresponding transitions occur on resonant levels, gives with relatively good accuracy the oscillator strength of the argon resonance lines [fr

  14. Vitamin K: from coagulation to calcification.

    Science.gov (United States)

    Paakkari, Ilari

    Vitamin K is not only essential for the synthesis of coagulation factors in the liver, but it also strengthens the bones and prevents calcification of the arteries. These effects are mediated through the same mechanism, i.e. carboxylation of Gla target proteins. The discovery of novel Gla proteins that are not associated with blood coagulation or calcium metabolism indicates that vitamin K has additional effects in the pancreas and the central nervous system, for example. As dietary supplements, vitamin K1 of plant origin and vitamins K2 of bacterial origin may exert different effects.

  15. Influence of argon plasma treatment on polyethersulphone surface

    Indian Academy of Sciences (India)

    2013-01-09

    Jan 9, 2013 ... waste water treatment from heavy and toxic metals, low-level nuclear waste management and separation of Zr from ... solid surface permits a rapid and qualitative evaluation of the SFE of the polymer. The water contact angle ...

  16. Gold coating of polyethylene modified by argon plasma discharge

    Czech Academy of Sciences Publication Activity Database

    Švorčík, V.; Kotál, V.; Slepička, P.; Bláhová, O.; Šutta, P.; Hnatowicz, Vladimír

    2006-01-01

    Roč. 46, č. 9 (2006), s. 1326-1332 ISSN 0032-3888 R&D Projects: GA ČR GA102/06/1106; GA MŠk(CZ) LC06041 Institutional research plan: CEZ:AV0Z10480505 Keywords : SURFACE MODIFICATION Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders Impact factor: 1.414, year: 2006

  17. THE RATIONALIZATION OF THE PARAMETERS OF MILK PROTEINS’ THERMO ACID COAGULATION BY BERRY COAGULANTS

    Directory of Open Access Journals (Sweden)

    Olena GREK

    2017-03-01

    Full Text Available This paper presents the results related to the influence of berry coagulant amount, its proactive acidity and duration of thermo acid coagulation on the process of milk proteins’ sedimentation. In the present work, the regression equations and response surface analysis were used to design and optimize an industrial bioprocess. Increase in the berry coagulant amount to 11 % and reduction of active acidity to 2.4 units were determined. pH up to 3 minutes is characterized by the highest processes of destabilization. Moreover, it improves the organoleptic properties and has the biggest impact on the yield of protein-berry clot (to 25 % and active acidity.

  18. Miniature Coaxial Plasma injector Diagnostics by Beam Plasma Interaction

    International Nuclear Information System (INIS)

    El-Tayeb, H.; El-Gamal, H.

    2003-01-01

    A miniature coaxial gun has been used to study the interaction between plasma beam and low density plasma formed in glow discharge. The peak discharge current flow between the coaxial electrodes was 5.25 kA as a single pulse with pulse width of 60 mu. Investigations are carried out with argon gas at pressure 0.4 Torr. The plasma stream ejected from the coaxial discharge propagates in the neutral argon atoms with mean velocity of 1.2x10 5 cm/s. The plasma stream temperature and density were 4.2 eV and 2.4x10 13 cm -3 respectively. An argon negative glow has been used as base plasma where its electron temperature and density were 2.2 eV and 6.2x10 7 cm -3 respectively. When the plasma stream propagates through the negative glow discharge region its velocity decreased to 8.8 x 10 4 cm/s and also the plasma electron temperature decreased to 3.1 eV, while the stream density remained the same. An excited wave appeared on the electric probe having frequency equal to the plasma frequency of the plasma under consideration. Simulation of the problem showed that this method could be applied for plasma diagnostics within the region of investigation. Those further studies for high temperature, dense, and magnetized plasma will be considered

  19. Upregulation of the coagulation factor VII gene during glucose deprivation is mediated by activating transcription factor 4.

    Science.gov (United States)

    Cronin, Katherine R; Mangan, Thomas P; Carew, Josephine A

    2012-01-01

    Constitutive production of blood coagulation proteins by hepatocytes is necessary for hemostasis. Stressful conditions trigger adaptive cellular responses and delay processing of most proteins, potentially affecting plasma levels of proteins secreted exclusively by hepatocytes. We examined the effect of glucose deprivation on expression of coagulation proteins by the human hepatoma cell line, HepG2. Expression of coagulation factor VII, which is required for initiation of blood coagulation, was elevated by glucose deprivation, while expression of other coagulation proteins decreased. Realtime PCR and ELISA demonstrated that the relative percentage expression +/- SD of steady-state F7 mRNA and secreted factor VII antigen were significantly increased (from 100+/-15% to 188+/-27% and 100+/-8.8% to 176.3+/-17.3% respectively, pfactor ATF4 and of additional stress-responsive genes. Small interfering RNAs directed against ATF4 potently reduced basal F7 expression, and prevented F7 upregulation by glucose deprivation. The response of the endogenous F7 gene was replicated in reporter gene assays, which further indicated that ATF4 effects were mediated via interaction with an amino acid response element in the F7 promoter. Our data indicated that glucose deprivation enhanced F7 expression in a mechanism reliant on prior ATF4 upregulation primarily due to increased transcription from the ATF4 gene. Of five coagulation protein genes examined, only F7 was upregulated, suggesting that its functions may be important in a systemic response to glucose deprivation stress.

  20. Novel approaches to the management of disseminated intravascular coagulation

    NARCIS (Netherlands)

    Levi, M. [=Marcel M.; de Jonge, E.; van der Poll, T.; ten Cate, H.

    2000-01-01

    Disseminated intravascular coagulation (DIC) is a syndrome characterized by systemic intravascular activation of coagulation, leading to widespread deposition of fibrin in the circulation. We addressed the issue of whether there is evidence that this fibrin deposition contributes to multiple organ

  1. Purification and Autoactivation Method for Recombinant Coagulation Factor VII.

    Science.gov (United States)

    Granovski, Vladimir; Freitas, Marcela C C; Abreu-Neto, Mario Soares; Covas, Dimas T

    2018-01-01

    Recombinant coagulation factor VII is a very important and complex protein employed for treatment of hemophiliac patients (hemophilia A/B) who develop inhibitors antibodies to conventional treatments (FVIII and FIX). The rFVII is a glycosylated molecule and circulates in plasma as zymogen of 50 kDa. When activated the molecule is cleaved to 20-30 kDa and has a half-life of about 3 h, needing to be processed fast and efficiently until freeze-drying. Here, we describe a very simple and fast purification sequence for rFVII using affinity FVII Select resin and a dialysis system that can be easily scaled up.

  2. Aluminium Morphological Modification by Nitrogen-Argon Mixture PIII

    International Nuclear Information System (INIS)

    Munnoz-Castro, A.E.; Valencia Alvarado, R.; Penna-Eguiluz, R.; Mercado-Cabrera, A.; Barocio, S.R.; Rodriguez-Mendez, B.G.; Lopez-Callejas, R.; Piedad-Beneitez, A. de la

    2011-01-01

    With incident fluences of ∼ 10 12 atoms/cm 2 aluminium samples have been plasma immersion ion implanted with either pure nitrogen or argon/nitrogen mixtures at temperatures around 450 o C. X-ray diffraction studies have validated the formation of the cubic phase of AlN, in samples treated with both the gas mixtures and pure nitrogen. Likewise, the presence of the hexagonal phase of AlN has been detected when either pure nitrogen or a 70% N/30% Ar mixture have been used. The signature peak of AlN has also been confirmed by the Raman spectroscopy. The maximal microhardness values were found in samples treated with the mixture. The maximal roughness was achieved with the equal part mixture in all cases, although increasing with the implantation pulse width up to a 300 nm peak at 150 μs. The latter critical value remains invariant under the pure nitrogen plasma treatment, provided that implantation periods in the order of 4.5 h are carried out. (author)

  3. Charge transfer cross-sections of argon ions colliding on argon atoms

    International Nuclear Information System (INIS)

    Aubert, J.; Bliman, S.; Chan-Tung, N.; Geller, R.; Jacquot, B.; Van Houtte, D.

    1980-04-01

    A device has been built to measure charge changing cross-sections of Argon ions colliding on argon atoms. It consists of an E.C.R. ion source (Micromafios) that delivers argon ions up to charge + 13. The ion source potential may be varied from 1 up to 10 kVolts. A first magnet is used to charge analyze the extracted beam. For a given separated charge state, the ion beam is passed in a collision cell whose pressure may be varied. The ions undergoing collisions on the target are analyzed by a second magnet and collected. The pressure is varied in the collision cell in order to check that the single collision condition is satisfied. It is shown that the ions do two types of collisions: charge exchange and stripping whose cross-sections are measured. Interpretation of charge exchange is proposed along yet classic theoretical approaches. As to stripping no available theory allows interpretation

  4. Coagulation factor VII variants resistant to inhibitory antibodies.

    Science.gov (United States)

    Branchini, Alessio; Baroni, Marcello; Pfeiffer, Caroline; Batorova, Angelika; Giansily-Blaizot, Muriel; Schved, Jean F; Mariani, Guglielmo; Bernardi, Francesco; Pinotti, Mirko

    2014-11-01

    Replacement therapy is currently used to prevent and treat bleeding episodes in coagulation factor deficiencies. However, structural differences between the endogenous and therapeutic proteins might increase the risk for immune complications. This study was aimed at identifying factor (F)VII variants resistant to inhibitory antibodies developed after treatment with recombinant activated factor VII (rFVIIa) in a FVII-deficient patient homozygous for the p.A354V-p.P464Hfs mutation, which predicts trace levels of an elongated FVII variant in plasma. We performed fluorescent bead-based binding, ELISA-based competition as well as fluorogenic functional (activated FX and thrombin generation) assays in plasma and with recombinant proteins. We found that antibodies displayed higher affinity for the active than for the zymogen FVII (half-maximal binding at 0.54 ± 0.04 and 0.78 ± 0.07 BU/ml, respectively), and inhibited the coagulation initiation phase with a second-order kinetics. Isotypic analysis showed a polyclonal response with a large predominance of IgG1. We hypothesised that structural differences in the carboxyl-terminus between the inherited FVII and the therapeutic molecules contributed to the immune response. Intriguingly, a naturally-occurring, poorly secreted and 5-residue truncated FVII (FVII-462X) escaped inhibition. Among a series of truncated rFVII molecules, we identified a well-secreted and catalytically competent variant (rFVII-464X) with reduced binding to antibodies (half-maximal binding at 0.198 ± 0.003 BU/ml) as compared to the rFVII-wt (0.032 ± 0.002 BU/ml), which led to a 40-time reduced inhibition in activated FX generation assays. Taken together our results provide a paradigmatic example of mutation-related inhibitory antibodies, strongly support the FVII carboxyl-terminus as their main target and identify inhibitor-resistant FVII variants.

  5. Coagulation activity in liver disease | Reza | Internet Journal of ...

    African Journals Online (AJOL)

    Patients with advanced hepatic failure may present with the entire spectrum of coagulation factor deficiencies. This study was designed to determine laboratory abnormalities in coagulation in chronic liver disease and the association of these abnormalities with the extent of chronic hepatitis and cirrhosis. Coagulation ...

  6. Quinine-induced disseminated intravascular coagulation.

    Science.gov (United States)

    Spearing, R L; Hickton, C M; Sizeland, P; Hannah, A; Bailey, R R

    Recurrent disseminated intravascular coagulation occurred in 3 women after ingestion of quinine tablets for cramp. All had circulating quinine-dependent antibodies to platelets and in 2 there was initial evidence of antibody consumption, with low titres that rose steeply over the next few days and remained high for many months.

  7. Brownian coagulation at high particle concentrations

    NARCIS (Netherlands)

    Trzeciak, T.M.

    2012-01-01

    The process of Brownian coagulation, whereby particles are brought together by thermal motion and grow by collisions, is one of the most fundamental processes influencing the final properties of particulate matter in a variety of technically important systems. It is of importance in colloids,

  8. Coagulation-flocculation studies of wastewaters

    NARCIS (Netherlands)

    Leentvaar, J.

    1982-01-01

    Although coagulation-flocculation processes have been practiced world-wide for almost a century in water treatment, several problems both in the theoretical and in the applied field have not been resolved yet. Especially interpretation of practical results with respect to governing

  9. 21 CFR 864.5400 - Coagulation instrument.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Coagulation instrument. 864.5400 Section 864.5400 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES HEMATOLOGY AND PATHOLOGY DEVICES Automated and Semi-Automated Hematology Devices § 864...

  10. Quantifying interspecific coagulation efficiency of phytoplankton

    DEFF Research Database (Denmark)

    Hansen, J.L.S.; Kiørboe, Thomas

    1997-01-01

    . nordenskjoeldii. Mutual coagulation between Skeletonema costatum and the non-sticky cel:ls of Ditylum brightwellii also proceeded with hall the efficiency of S. costatum alone. The latex beads were suitable to be used as 'standard particles' to quantify the ability of phytoplankton to prime aggregation...

  11. Comparison of electrocoagulation and chemical coagulation ...

    African Journals Online (AJOL)

    In this work, electrocoagulation and chemical coagulation were applied to the exit effluent of a textile factory located at Douala (Cameroon).The investigations were focused on the operational (pH, conductivity) and pollution parameters (COD, total phosphorus, turbidity). The electrolytic treatment was carried out with 0.4 A ...

  12. TRAITEMENT DES EAUX USEES PAR COAGULATION-FLOCULATION EN UTILISANT LE SULFATE D’ALUMINIUM COMME COAGULANT

    OpenAIRE

    Nora SEGHAIRI; Leila MIMECHE; Adel BOUZID; Yassir AYACHI

    2017-01-01

    Domestic wastewater treatment by coagulation-flocculation is widely used internationally. This treatment reduces color and turbidity, indicating organic and inorganic contaminants, but at acceptable levels for treated waste water discharged into the receiving environment. The objective of this study is to optimize the treatment of wastewater by coagulation-flocculation using aluminum sulphate as a coagulant. Various reaction parameters are taken into account, such as the coagulant dose,...

  13. Enhanced coagulation for improving coagulation performance and reducing residual aluminum combining polyaluminum chloride with diatomite.

    Science.gov (United States)

    Hu, Wenchao; Wu, Chunde

    2016-01-01

    The feasibility of using enhanced coagulation, which combined polyaluminum chloride (PAC) with diatomite for improving coagulation performance and reducing the residual aluminum (Al), was discussed. The effects of PAC and diatomite dosage on the coagulation performance and residual Al were mainly investigated. Results demonstrated that the removal efficiencies of turbidity, dissolved organic carbon (DOC), and UV254 were significantly improved by the enhanced coagulation, compared with PAC coagulation alone. Meaningfully, the five forms of residual Al (total Al (TAl), total dissolved Al (TDAl), dissolved organic Al (DOAl), dissolved monomeric Al (DMAl), and dissolved organic monomeric Al (DOMAl)) all had different degrees of reduction in the presence of diatomite and achieved the lowest concentrations (0.185, 0.06, 0.053, 0.014, and 0 mg L(-1), respectively) at a PAC dose of 15 mg L(-1) and diatomite dose of 40 mg L(-1). In addition, when PAC was used as coagulant, the majority of residual Al existed in dissolved form (about 31.14-70.16%), and the content of DOMAl was small in the DMAl.

  14. The immediate and late effects of thyroid hormone (triiodothyronine) on murine coagulation gene transcription.

    Science.gov (United States)

    Salloum-Asfar, Salam; Boelen, Anita; Reitsma, Pieter H; van Vlijmen, Bart J M

    2015-01-01

    Thyroid dysfunction is associated with changes in coagulation. The aim of our study was to gain more insight into the role of thyroid hormone in coagulation control. C57Black/6J mice received a low-iodine diet and drinking water supplemented with perchlorate to suppress endogenous triiodothyronine (T3) and thyroxine (T4) production. Under these conditions, the impact of exogenous T3 on plasma coagulation, and hepatic and vessel-wall-associated coagulation gene transcription was studied in a short- (4 hours) and long-term (14 days) setting. Comparing euthyroid conditions (normal mice), with hypothyroidism (conditions of a shortage of thyroid hormone) and those with replacement by incremental doses of T3, dosages of 0 and 0.5 μg T3/mouse/day were selected to study the impact of T3 on coagulation gene transcription. Under these conditions, a single injection of T3 injection increased strongly hepatic transcript levels of the well-characterized T3-responsive genes deiodinase type 1 (Dio1) and Spot14 within 4 hours. This coincided with significantly reduced mRNA levels of Fgg, Serpinc1, Proc, Proz, and Serpin10, and the reduction of the latter three persisted upon daily treatment with T3 for 14 days. Prolonged T3 treatment induced a significant down-regulation in factor (F) 2, F9 and F10 transcript levels, while F11 and F12 levels increased. Activity levels in plasma largely paralleled these mRNA changes. Thbd transcript levels in the lung (vessel-wall-associated coagulation) were significantly up-regulated after a single T3 injection, and persisted upon prolonged T3 exposure. Two-week T3 administration also resulted in increased Vwf and Tfpi mRNA levels, whereas Tf levels decreased. These data showed that T3 has specific effects on coagulation, with Fgg, Serpinc1, Proc, Proz, Serpin10 and Thbd responding rapidly, making these likely direct thyroid hormone receptor targets. F2, F9, F10, F11, F12, Vwf, Tf and Tfpi are late responding genes and probably indirectly

  15. Argon spill in the hall of the ATLAS experiment

    CERN Document Server

    Peón-Hernández, G

    1998-01-01

    A hazard analysis is in progress to determine the operation mode of the ventilation system in the ATLAS hall in case of an Argon spill. Two risk scenarios have been investigated so far. In the first, the behaviour of an Argon gas pool is calculated for different ventilation strategies. In the second, the behaviour of Argon gas leaking from the bottom part of the detector is studied for different flows. The description of the study, results and conclusions are presented.

  16. Study of argon-oxygen flowing afterglow

    Science.gov (United States)

    Mazánková, V.; Trunec, D.; Navrátil, Z.; Raud, J.; Krčma, F.

    2016-06-01

    The reaction kinetics in argon-oxygen flowing afterglow (post-discharge) was studied using NO titration and optical emission spectroscopy. The flowing DC post-discharge in argon-oxygen mixture was created in a quartz tube at the total gas pressure of 1000 Pa and discharge power of 90 W. The O(3P) atom concentration was determined by NO titration at different places along the flow tube. The optical emission spectra were also measured along the flow tube. Argon spectral lines, oxygen lines at 777 nm and 844.6 nm and atmospheric A-band of {{\\text{O}}2} were identified in the spectra. Rotational temperature of {{\\text{O}}2} was determined from the oxygen atmospheric A-band and also the outer wall temperature of the flow tube was measured by a thermocouple and by an IR thermometer. A zero-dimensional kinetic model for the reactions in the afterglow was developed. This model allows the time dependencies of particle concentrations and of gas temperature to be calculated. The wall recombination probability for O(3P) atoms {γ\\text{O≤ft(\\text{P}\\right)}}=≤ft(1.63+/- 0.06\\right)× {{10}-3} and wall deactivation probability for {{\\text{O}}2} (b {{}1}Σ\\text{g}+ ) molecules {γ{{\\text{O}2}≤ft(\\text{b}\\right)}}=≤ft(1.7+/- 0.1\\right)× {{10}-3} were determined from the fit of model results to experimental data. Sensitivity analysis was applied for the analysis of kinetic model in order to reveal the most important reactions in the model. The calculated gas temperature increases in the afterglow and then decreases at later afterglow times after reaching the maximum. This behavior is in good agreement with the spatial rotational temperature dependence. A similar trend was also observed at outer wall temperature measurement.

  17. Argon laser treatment of central serous chorioretinopathy

    Directory of Open Access Journals (Sweden)

    Ting- Bing Fang

    2013-04-01

    Full Text Available AIM: To observe the efficacy of the argon laser photocoagulation treatment of central serous chorioretinopathy(CSC. METHODS: The treatment groups: 18 patients(18 eyes, argon laser photocoagulation and oral jolethin, vitamin B1, inosine and venoruton tablets. Control group: 18 patients(18 eyes, oral lecithin complex iodine, vitamin B1, inosine, venoruton tablets. Foveal thickness and neuroepithelial layer detachment range were measured by optical coherence tomography(OCTbefore treatment, after 1 month and 3 months post-operation to compare the decline in value of foveal thickness and neuroepithelial layer detachment range of the two groups. RESULTS: After 1 month of treatment, the decline in value of the center foveal thickness: the value of treatment group was 256±72μm; the value of the control group was 82±57μm, and the difference of the two groups, P <0.05; the decline in value of neuroepithelial layer detachment range: the value of the treatment group was 3 548±168μm, the value of the control group was 1 520±143μm, And the difference of the two groups, P<0.05. After three months of treatment, the decline in value of the center foveal thickness: the value of treatment group was 383±75μm, the value of the control group was 312±67 μm, and the difference of the two groups, P<0.05; decline in value of neuroepithelial layer detachment range: the value of the treatment group was 4 908±172μm, the value of the control group was 4 211±153μm, and the difference of the two groups, P <0.05. The differences were statistically significant between the treatment and the control groups(two independent samples t-test. CONCLUSION:Argon laser photocoagulation treatment of CSC is an effective treatment method and can significantly shorten the course.

  18. Decomposition of poly(amide-imide) film enameled on solid copper wire using atmospheric pressure non-equilibrium plasma.

    Science.gov (United States)

    Sugiyama, Kazuo; Suzuki, Katsunori; Kuwasima, Shusuke; Aoki, Yosuke; Yajima, Tatsuhiko

    2009-01-01

    The decomposition of a poly(amide-imide) thin film coated on a solid copper wire was attempted using atmospheric pressure non-equilibrium plasma. The plasma was produced by applying microwave power to an electrically conductive material in a gas mixture of argon, oxygen, and hydrogen. The poly(amide-imide) thin film was easily decomposed by argon-oxygen mixed gas plasma and an oxidized copper surface was obtained. The reduction of the oxidized surface with argon-hydrogen mixed gas plasma rapidly yielded a metallic copper surface. A continuous plasma heat-treatment process using a combination of both the argon-oxygen plasma and argon-hydrogen plasma was found to be suitable for the decomposition of the poly(amide-imide) thin film coated on the solid copper wire.

  19. Enrichment of trace metals in water utilizing the coagulation of soybean protein

    International Nuclear Information System (INIS)

    Musha, Soichiro; Takahashi, Yoshihisa.

    1975-01-01

    An enrichment of trace metals in water with a coagulated soybean protein and the complex-forming character of heavy metal ions with the soybean protein were investigated by means of emission spectrography. Fixed amounts of soybean milk (collector) and delta-gluconic lactone (coagulant) were added to a sample solution containing various metal ions, and then the mixture was heated to boiling in order to coagulate the protein. The coagulum (soybean curd) separated from the suspension with a centrifuge was burned to ashes with a low temperature plasma asher. Then metals enriched in the soybean curd were determined by means of emission spectrography. The pH of the solution was adjusted to 4.4--5.0 by adding suitable amounts of delta-gluconic lactone for the complete coagulation of the soybean protein. The proposed method can be applied to the collection and enrichment of various metal ions such as gold, silver, mercury, platinum, cadmium, beryllium, palladium, antimony, gallium, indium, cerium, lanthanum, thorium, yttrium, zirconium, etc. Those metals are not detectable in the original soybean. (auth.)

  20. Coagulation disorders in the patients with deep vein thrombosis of lower extremity

    Directory of Open Access Journals (Sweden)

    Milić Dragan J.

    2003-01-01

    Full Text Available PURPOSE Venous thromboembolism is a relevant social and health care problem for its high incidence, pulmonary embolism-related mortality and long-term sequelae which may be disabling (post-thrombotic syndrome and ulceration. PROCEDURES The aim of our work was to establish the presence of coagulation disorders (hypercoagulable states in the patients with deep vein thrombosis (DVT of the leg. Prospectively we have analyzed a group of 30 patients with echosono-graphicaly verified DVT of the leg who were admitted to the department of vascular surgery from August 1st 2000 to July 31st 2001.The following parameters were monitored: prothrombin time (PT partial thromboplastin time (PTT, fibrinogen (Fib, alpha 2 antiplasmin (A-2 AP, D-dimer (DD, antithrombin III (AT III and factor VII. FINDINGS Activation of the coagulation process was registered. The values of monitored coagulation parameters are shown in table 1. Plasma levels of monitored parameters in the patients with DVT of the leg were significantly higher than in the control subjects. CONCLUSION In patients with a DVT a hypercoagulable state is common finding. Some parameters of coagulation activity such as D-dimer might be of great interest in the diagnostic strategy of DVT.