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Sample records for grossly visible emphysematous

  1. Spatial distribution of grossly visible diseases and parasites in flounder ( Platichthys flesus ) from the Baltic Sea : a synoptic survey

    DEFF Research Database (Denmark)

    Lang, T.; Mellergaard, Stig; Wosniok, W.;

    1999-01-01

    for lymphocystis (14.4%) and acute/healing stages of the skin ulcer disease (5.9%). The prevalences of liver neoplasms >2 mm in diameter (0.4%), skeletal deformities (0.6%), and fin rot/erosion (0.5%) were low. The only externally visible parasite recorded was Cryptocotyle concavum (28.2%). The results......Information on prevalences of grossly visible diseases and parasites of flounder (Platichthys flesus) from the Baltic Sea is presented for 11 sampling areas on a transect from the Mecklenburg Eight to the Gulf of Finland. Among the 3008 flounder examined, highest overall prevalences were observed...... of a multivariate statistical analysis reveal that the diseases are influenced by a variety of host-specific (length, age, sex) and area-specific (salinity, temperature) factors as well as their interactions. By calculating the expected prevalence for a standardized fish population for each area and disease...

  2. Emphysematous pyelitis

    Directory of Open Access Journals (Sweden)

    Onur Karsli

    2016-03-01

    Full Text Available Emphysematous pyelonephritis is a rare life -threatening suppurative necrotizing infection of kidney parenchyma or perirenal tissue characterized by the formation of gas. In the present case, Emphysematous pyelitis is a less common variant of emphysematous pyelonephritis and describes the conservative treatment options. The purpose of this paper is to show that a serious condition with emphysematous pyelitis may regress with aggressive medical therapy. [Cukurova Med J 2016; 41(0.100: 63-65

  3. Emphysematous pyelonephritis

    Energy Technology Data Exchange (ETDEWEB)

    Tomiie, Fumitaka; Maeda, Tomoho [Kyoto Prefectural Univ. of Medicine (Japan); Nakano, Yasuhiko; Yasuda, Yoshikazu; Kashii, Akiyoshi; Kanazawa, Kyotaro; Furuse, Makoto; Ohsawa, Tadashi; Munechika, Hirotsugu

    1995-09-01

    Emphysematous pyelonephritis is a rare, life-threatening necrotizing renal infection characterized by the production of intrarenal and perirenal gas. Six cases of emphysematous pyelonephritis were reviewed. Five cases were associated with diabetes mellitus and one with obstructive nephrouropathy. Bilateral emphysematous involvement was seen in two and unilateral involvement in four cases. Those two cases with bilateral involvement were accompanied with thoracic lesions such as mediastinitis and/or pleuritis. In two cases of medical management alone, multiple organ failure secondary to sepsis was a cause of death. CT provided valuable information for a correct diagnosis and for the progression of a disease process. The thorax of CT examination should be included for survey of possible mediastinal and/or pleural involvement. (author).

  4. Emphysematous vaginitis.

    Science.gov (United States)

    Lima-Silva, Joana; Vieira-Baptista, Pedro; Cavaco-Gomes, João; Maia, Tiago; Beires, Jorge

    2015-04-01

    Emphysematous vaginitis is a rare condition, characterized by the presence of multiple gas-filled cysts in the vaginal and/or exocervical mucosa. Although its etiology is not completely understood, it is self-limited, with a benign clinical course. Vaginal discharge, sometimes bloody, and pruritus are the most common symptoms. Chronic and acute inflammation can be found, and diseases that impair the immune system and pregnancy have been associated with this condition. A 48-year-old postmenopausal woman, with a history of hysterectomy with several comorbidities, presented with a 4-month history of bloody discharge and vulvar pruritus. Examination showed multiple cystic lesions, 1 to 5 mm, occupying the posterior and right lateral vaginal walls. Speculum examination produced crepitus. Vaginal wet mount was normal, except for diminished lactobacilli; results of Trichomonas vaginalis DNA test and vaginal cultures were negative. Lugol's iodine applied to the vagina was taken up by the intact lesions. Biopsy result showed typical features of emphysematous vaginitis. This is an unusual entity, presenting with common gynecological complaints, and both physicians and pathologists should be aware to prevent misdiagnosis and overtreatment.

  5. Emphysematous pyelonephritis: surgical implications.

    Science.gov (United States)

    Shahatto, N; al Awadhi, N Z; Ghazali, S

    1990-12-01

    Emphysematous pyelonephritis in patients with diabetes mellitus is increasingly recognised as a disease requiring urgent and aggressive treatment. We present 3 cases of emphysematous pyelonephritis; 1 patient required percutaneous nephrostomy followed by nephroureterectomy but the other 2 were successfully managed with antibiotics and control of diabetes. Diagnosis was confirmed by sequential imaging techniques which demonstrated an inflammatory renal mass associated with gas and fluid.

  6. Concurrent emphysematous cholecystitis and emphysematous pancreatitis: a case report

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    Choi, Hee Seok; Lee, Yong Seok; Yoon, Yup [Dongguk University International Hospital, Dongguk University College of Medicine, Goyang (Korea, Republic of); Park, Sung Bin [Ulsan University Hospital, University of Ulsan College of Medicine, Seoul (Korea, Republic of)

    2008-01-15

    Emphysematous infections of the abdomen and pelvis are potentially life-threatening conditions which require aggressive medical and surgical management. Therefore, early radiographic detection is important in the management of these conditions. Concurrent emphysematous infections involving different organs have been rarely reported, and primarily occur in immunocompromised patients. Here, we report a rare case of concurrent emphysematous cholecystitis and emphysematous pancreatitis in a 97 year old male patient.

  7. Acute bilateral emphysematous pyelonephritis

    Science.gov (United States)

    Surur, John

    2011-01-01

    The author reports the case of a well and fit patient who presented herself to the emergency department and was found to have bilateral emphysematous pyelonephritis. She was admitted to the intensive care where she was initially treated conservatively with antibiotics, percutaneous drainage and continuous renal replacement therapy, but her condition deteriorated. She underwent a left total nephrectomy and a partial right nephrectomy that resulted in remarkable improvement. The patient started passing urine spontaneously, so no haemofiltration was required. She was discharged home and her case was followed-up by an urologist and nephrologist. This case lays emphasis on thoroughly investigating and managing a patient with bilateral emphysematous pyelonephritis and, in relation to its management, on the dilemma of whether the treatment of choice should be conservative or surgical. PMID:22707665

  8. Emphysematous Cystitis: A Case Report

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    Suleyman Tagci

    2014-12-01

    Full Text Available Emphysematous cystitis is an infectious disease, which is characterized by accumulation of air within the lumen and wall of the bladder. Diabetes mellitus, neurogenic bladder and advanced age are important risk factors for the development of the disease. In this case report, we present a young diabetic male patient with neurogenic bladder, who was treated with the diagnosis of emphysematous cystitis.

  9. Conservative management of emphysematous pyelonephritis

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    Bashir Ahmad Laway

    2012-01-01

    Full Text Available Emphysematous pyelonephritis, though uncommon, is a severe necrotizing kidney infection common in patients with diabetes. Surgical treatment has been advocated as the treatment of choice in most of the patients. We present the clinical course of an elderly lady who presented with emphysematous pyelonephritis and was successfully managed with medical treatment despite the presence of adverse prognostic factors like acute renal failure and thrombocytopenia.

  10. Emphysematous pyelonephritis; Emphysematoese Pyelonephritis

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    Heinze, A.; Migeod, K. [Klinikum Ingolstadt (Germany). Inst. fuer Diagnostische und Interventionelle Radiologie

    1998-05-01

    Emphysematous pyelonephritisis a relatively rare, gas-producing, destructive and usually unilateral renal infection. Often the patients are female diabetics and mostly the left kidney is affected. The pathological gas formation is either limited to the kidney or extends to the perirenal space. Two cases are reported, which - in clinical presentation, extension of pathological gas, and treatment - present two possible ends of the spectrum of this disease. (orig.) [Deutsch] Bei der Emphysematoesen Pyelonephritis handelt es sich um eine relativ seltene gasbildende destruierende und gewoehnlich unilateral auftretende renale Infektion. Die Erkrankung betrifft haeufig Diabetikerinnen und meistens die linke Niere. Die Gasbildung ist entweder auf die Niere beschraenkt oder zeigt eine Ausbreitung auf den Perirenalraum. Es wird ueber zwei Faelle dieser Erkrankung berichtet, die in klinischer Darstellung, Ausbreitung der Gasbildung und Therapie zwei moegliche Eckpunkte eines Spektrums dieser Erkrankung repraesentieren. (orig.)

  11. Cistitis enfisematosa Emphysematous Cistitis

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    Claudio Orlich-Castelán

    2010-06-01

    Full Text Available Se reporta el caso de un marinero con diabetes mellitus descompensada e insuficiencia renal con una cistitis enfisematosa, evidente en un ultrasonido de la vejiga que se presentó con hematuria, disuria, dolor suprapúbico y síntomas urinarios obstructivos, tratada inicialmente en altamar por 48 horas, con antibióticos. Se mantuvo en excelente estado general y afebril, sin poder aislar una bacteria causal, por haberse iniciado antibioticoterapia temprana; fue tratado además con cirugía conservadora, con debridamiento y lavado de tejidos afectados con agua oxigenada y solución yodada, y con derivación de la orina con una cistostomía suprapúbica, para una excelente evolución y resultado final.We herein report an uncommon case of a diabetic sailor with renal failure and emphysematous cystitis, who presented with hematuria, dysuria, suprapubic pain and obstructive urinary symptoms, initially treated at sea with antibiotics, with an ultrasound showing the presence of gas. This man remained in good general condition with no fever, but it was not possible to isolate bacteria in the cultures because of early use of antibiotics. He was also treated conservatively with surgical debridement of superficial tissues and bladder mucosa, washings with peroxide and iodine solutions and with a suprapubic tube for urinary diversion. The outcome was excellent with bladder preservation and full recovery of his health.

  12. Emphysematous cystitis: 3 cases report

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    Chun, Ho Jong; Byun, Jae Young; Lee, Jae Moon; Ro, Hee Jung; Shinn, Kyung Sub [Catholic University Medical College, Seoul (Korea, Republic of)

    1995-09-15

    Emphysematous cystitis is a rare condition characterized by gas collection in the wall and lumen of the bladder. We experienced three cases of emphysematous cystitis. All patients were female; one was associated with a long term history of diabetes mellitus and another with urinary indwelling catheter. All of the cases were easily diagnosed on plain radiograph and CT scan, and were successfully treated with antibiotic therapy. In one of the cases, however, associated abscess due to perivesical extension of inflammation was treated by combined external drainage.

  13. [Emphysematous pyelonephritis: a case report].

    Science.gov (United States)

    Rabii, R; Fekak, H; Mezzour, H; Joual, A; Moufid, K; el Mrini, M; Benjelloun, S; Cherkab, R; Bensaid, A; el Kettani, C; Barrou, L

    2003-04-01

    Diabetic patients with urinary tract infections had a certain risk of developping emphysematous pyelonephritis with gas producting bacteria. This disease was accompagned with high mortalité. We will report one case who was treated successfully by high dose antibiotic regim and emergency nephrectomy.

  14. Emphysematous cholecystitis Colecistite enfisematosa

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    Renato Micelli Lupinacci

    2009-12-01

    Full Text Available BACKGROUND: Emphysematous cholecystitis is life-threatening condition characterized by gas-forming infection of the gallbladder. It is mostly seems in old male patients with systemic, specially diabetes and vascular diseases. CASE REPORT: - A 30-year-old man without previous diseases was admitted because of right upper quadrant pain and nausea. On admission the patient was febrile (38.7o with normal bilirubin levels. The white blood count was 26700/µl and reactive protein C was 470. Axial sections of single slice computed tomography imaging (section thickness 5 mm, revealed gallbladder wall enhancement after i.v. contrast, as well as dilatation of the gallbladder with intraluminal air. The patient underwent open cholecystectomy. The culture of the bile showed clostridium perfringes. The postoperative course of the patient was uneventful. CONCLUSION: This is a rare form of cholecystitis that carries a high mortality and usually present insidious clinical signs. CT is the most accurate imaging technique. Antibiotic therapy should begin quickly and include coverage of common pathogens, particularly Clostridia. Surgical intervention should take place as early as possible.INTRODUÇÃO: Colecistite enfisematosa é uma condição de risco de vida caracterizada por infecção da vesícula biliar por agentes produtores de gás. Na sua apresentação mais comum atinge preferencialmente homens idosos portadores de doenças sistêmicas em especial diabetes e vasculopatias. RELATO DO CASO: Paciente do sexo masculino, 30 anos de idade e sem co-morbidades que se apresenta ao pronto-socorro com história de dor abdominal em hipocôndrio direito há cinco dias, febre (38,7o e náuseas. Os exames laboratoriais mostravam leucocitose (26700/µl e elevação dos marcadores de inflamação (proteína C reativa, PCR 470. A tomografia computadorizada do abdome revelou realce da parede vesicular após injeção de contraste i.v., bem como dilatação da vesícula com a

  15. Pregnancy complicated by emphysematous pyonephrosis.

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    Gaither, Kecia; Ardite, Andrea; Mason, Tina C

    2005-10-01

    Emphysematous pyonephrosis is a rare, rapidly progressive infection characterized by the presence of exudative material and fermentative gases within a dilated renal collecting system. This unusual clinical entity is noted almost exclusively in diabetic patients, often in conjunction with chronic urinary tract infection and obstruction. In most instances, E. coli is the etiologic agent; however other enterobacteriaceae may be isolated. High fever, leukocytosis, renal parenchymal necrosis and the accumulation of gases in the kidney and perinephric tissues are the hallmark of this condition. Surgical resection of the involved tissue and systemic antibiotic administration are among the primary mainstays of therapy. We present a unique case of a pregnant patient with fulminant emphysematous pyonephrosis and the successful treatment rendered.

  16. Emphysematous prostatitis in renal transplant

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    Krishnaswamy Sampathkumar

    2007-01-01

    Full Text Available Urinary tract infections are common following renal transplant. The spectrum varies from asymptomatic bacteriuria to septicemia. Gas-producing infections of the urinary tract are rare but tend to have a grave prognosis when they do occur. We report a 57-year-old gentleman who underwent a renal transplant 20 months earlier. He presented to us with fever and dysuria. Clinical examination revealed a febrile and ill-looking patient with severe graft tenderness. An emergency pelvic CT scan revealed presence of emphysematous prostatitis, cystitis and pyelitis. Urine and blood cultures grew E. coli . Endoscopic abscess drainage was done and antibiotics given but he succumbed to his illness due to multiorgan failure within 48h. This is the first reported case of emphysematous prostatitis in a renal allograft recipient.

  17. [Emphysematous gastritis with concomitant portal venous air].

    Science.gov (United States)

    Jeong, Min Yeong; Kim, Jin Il; Kim, Jae Young; Kim, Hyun Ho; Jo, Ik Hyun; Seo, Jae Hyun; Kim, Il Kyu; Cheung, Dae Young

    2015-02-01

    Emphysematous gastritis is a rare form of gastritis caused by infection of the stomach wall by gas forming bacteria. It is a very rare condition that carries a high mortality rate. Portal venous gas shadow represents elevation of intestinal luminal pressure which manifests as emphysematous gastritis or gastric emphysema. Literature reviews show that the mortality rate is especially high when portal venous gas shadow is present on CT scan. Until recently, the treatment of emphysematous gastritis has been immediate surgical intervention. However, there is a recent trend of avoiding surgery because of the frequent occurrence of post-operative complications such as anastomosis leakage. In addition, aggressive surgical treatment has failed to show significant improvement in prognosis. Recently, the authors experienced a case of emphysematous gastritis accompanied by portal venous gas which was treated successfully by conservative treatment without immediate surgical intervention. Herein, we present a case of emphysematous gastritis with concomitant portal venous air along with literature review.

  18. Emphysematous prostatic abscess with rectoprostatic fistula

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    Po-Cheng Chen

    2014-12-01

    Full Text Available Emphysematous prostatic abscess is a rare but relatively serious infectious disease, and its association with rectoprostatic fistula is extremely unusual. The reported risk factors for this condition include diabetes mellitus, immunosuppression, and prostate surgery. We report a rare case of emphysematous prostatic abscess successfully treated by transurethral drainage. Nonetheless, a rectoprostatic fistula was found postoperatively. The fistula healed spontaneously without fasting or fecal diversion after suprapubic cystostomy and placement of a urethral catheter. This case highlights the importance of surgical drainage for the treatment of an emphysematous prostatic abscess and that conservative treatment can be a safe and effective approach for an associated rectoprostatic fistula.

  19. Successful conservative treatment of emphysematous gastritis.

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    Takano, Yuichi; Yamamura, Eiichi; Gomi, Kuniyo; Tohata, Misako; Endo, Toshiyuki; Suzuki, Reika; Hayashi, Masafumi; Nakanishi, Toru; Hanamura, Shotaro; Asonuma, Kunio; Ino, Satoshi; Kuroki, Yuichiro; Maruoka, Naotaka; Nagahama, Masatsugu; Inoue, Kazuaki; Takahashi, Hiroshi

    2015-01-01

    Emphysematous gastritis is an extremely rare disease with an unfavorable prognosis. To date, very few studies have been conducted regarding the intragastric recovery process based on endoscopic findings. We herein report a case of emphysematous gastritis that improved with long-term (five months) conservative treatment in which we were able to observe the intragastric recovery process endoscopically. In cases in which emphysematous gastritis is suspected, it is important to provide prompt diagnostic imaging (including CT) and early appropriate treatment in order to improve the prognosis.

  20. Severe emphysematous pyelonephritis mimicking intestinal obstruction.

    Science.gov (United States)

    Sun, Ji Ning; Zhang, Bao Long; Yu, Hai Yan; Wang, Bin

    2015-12-01

    Emphysematous pyelonephritis is a severe necrotizing infection characterized by the presence of gas and/or fluid in the renal parenchyma, collecting system, or perirenal tissues. Emphysematous pyelonephritis with approximately 15 cm air-fluid level, diffused ureteral involvement, and the accumulation of gas in liver and peritoneal cavity is very rare. Here, we reported a severe emphysematous pyelonephritis with multiple huge air-fluid level mimicking intestinal obstruction and with the accumulation of gas in liver and ureter in computed tomography imaging. The patient was successfully managed by percutaneous nephrostomy combined with medical treatment.

  1. Emphysematous Cystitis: Report of an Atypical Case

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    Karen De Baets

    2011-01-01

    Full Text Available We report the atypical case of a nondiabetic 66-year old male with severe abdominal pain and vomiting who was found to have emphysematous cystitis. Of all gas-forming infections of the urinary tract emphysematous cystitis is the most common and the least severe. The major risk factors are diabetes mellitus and urinary tract obstruction. Most frequent causative pathogens are Escherichia coli and Klebsiella pneumoniae. The clinical presentation is nonspecific and ranges from asymptomatic urinary tract infection to urosepsis and septic shock. The diagnosis is made by abdominal imaging. Treatment consists of broad-spectrum antibiotics, bladder drainage, and management of the risk factors. Surgery is reserved for severe cases. Overall mortality rate of emphysematous cystitis is 7%. Immediate diagnosis and treatment is necessary because of the rapid progression to bladder necrosis, emphysematous pyelonephritis, urosepsis, and possibly fatal evolution.

  2. Emphysematous cystitis of the diabetic patient

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    Affes Nejmeddine

    2009-01-01

    Full Text Available Background : Emphysematous cystitis is defined by the presence of gas in the urinary bladder wall. It complicates urinary tract infections especially in diabetic patients. Aims : We present a case of emphysematous cystitis in a diabetic patient with a poor glycemia control and we discuss diagnostics and treatment items of this uncommon and serious infection. Methods and Results : A 45-year-old man was admitted to the emergency department with confusion and abdominal pain. The clinical examination found a septic shock the Ultra-sonography (US showed a cholecystitis the patient was operated without amelioration. A post operative pelvic computed tomography (CT demonstrated intramural gas in the urinary bladder, which suggested a diagnosis of emphysematous cystitis. The treatment was based on an antibiotics associated with a bladder drainage. The evolution was in favor. Conclusion : Every diabetic patient with a urinary tract infection who seems to be severely ill should have an abdominal X-ray as a minimal screening tool to detect emphysematous complications. (Nejmeddine A, Atef B, Youssef D, Ramez B, Issam BM. Emphysematous cystitis of the diabetic patient.

  3. Emphysematous pyelonephritis. Clinical findings and radiological diagnosis

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    Tomiie, Fumitaka; Okuyama, Chio; Kizu, Osamu [Kyoto Prefectural Univ. of Medicine (Japan)] [and others

    1996-01-01

    Emphysematous pyelonephritis is a rare, life-threatening necrotizing renal infection characterized by the production of intrarenal and perirenal gas. Seven patients with emphysematous pyelonephritis were reviewed. Six patients were associated with diabetes mellitus and one with obstructive nephrouropathy. Bilateral emphysematous involvement was seen in two and unilateral involvement in five patients. Bilateral disease was accompanied by thoracic lesions such as mediastinitis and/or pleuritis. In two of three patients with medical management alone, multiple organ failure secondary to sepsis was a cause of death. CT provided information indispensable to a correct diagnosis and was useful in evaluating the extension of the disease process. In patients with bilateral disease or unilateral involvement with a prolonged history, CT scan of the thorax is recommended for the survey of mediastinal and/or pleural involvement. (author).

  4. Emphysematous epididymo-orchitis: A rare entity

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    Alok Mathur

    2011-01-01

    Full Text Available Emphysematous epididymo-orchitis is a rare cause of an acute scrotum and is a surgical emergency. Diagnosis is clinically difficult, and sonography with a high-frequency probe is useful to pick up gas shadows in the scrotal wall or testicular substance. A diabetic patient presented with fever, urinary tract infection, and an acute scrotal swelling. The patient needed orchidectomy and scrotal debridement. As in emphysematous pyelonephritis, this condition occurs in diabetics, and patients may need surgery. There is a need to perform sonography in all diabetic patients with an acutely inflamed scrotum, because detection of gas shadows makes surgical intervention more likely.

  5. Ascending necrotizing mediastinitis secondary to emphysematous pyelonephritis.

    Science.gov (United States)

    Dajer-Fadel, Walid Leonardo; Pichardo-González, Martha; Estrada-Ramos, Sandra; Palafox, Damián; Navarro-Reynoso, Francisco Pascual; Argüero-Sánchez, Rubén

    2014-09-01

    Mediastinal infections usually originate from postoperative complications or in a descending manner from a cervical infectious process; few reports have emerged describing an ascending trajectory. A 56-year-old woman with a Huang class 1 left emphysematous pyelonephritis was referred due to a progression of an ascending necrotizing mediastinitis. A left posterolateral thoracotomy was performed, drainage and thorough lavage were carried out with a successful outcome. We believe this is the first reported case of ascending necrotizing mediastinitis secondary to an emphysematous renal infection. © The Author(s) 2013 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.

  6. EMPHYSEMATOUS PYELONEPHRITIS: OUR INSTITUTIONAL EXPERIENCE

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    Prakasa Rao

    2015-11-01

    Full Text Available : Emphysematous pyelonephritis (EPN is a rare acute necrotizing infection of renal parenchyma. We discuss clinical details and treatment strategies of 28 patients with EPN followed at our hospital. EPN is common in persons with diabetes, often has a fulminating course and can be fatal if not recognized and treated promptly. Its overall mortality rate ranges between 19% and 43%. METHODS: We retrospectively reviewed the clinical, laboratory, radiological findings and treatment modalities of 18 patients with EPN followed at our hospital between 2012 and 2014. RESULTS: The mean patient age (Female: 12; male: 6 was 65 years (Range: 51–82. Based on computed tomographic findings, EPN was classified as class I (n=3, class II (n=6, class IIIA (n=5, class IIIB (n=3 and class 1V (n=1. All patients had fever, flank pain, nausea, and vomiting. Sixteen patients had type 2 diabetes mellitus and 4 diabetic patients also had renal stones. Escherichia coli (n=14, Klebsiella species (n=3, and mixed species (n=1 were grown in urine cultures. Seventeen patients had unilateral involvement. Increased white blood cell counts, sedimentation rate, and C-reactive protein levels were detected in all cases. In addition to medical treatment, 5 patients underwent a nephrostomy catheter placement and a total of 3 patients underwent nephrectomy upon deterioration. After achieving clinical stabilisation with medical treatment, 7 patients underwent endoscopic ureteral stone treatment. The remaining 3 cases were treated only with antibiotics. One patient died even after nephrostomy and antibiotic therapy and seventeen patients were discharged with clinical cure. CONCLUSION: Mortality rates of EPN are gradually decreasing. Preservation of renal reserve is possible due to early diagnosis, appropriate antibiotic therapy, and drainage.

  7. Thoracic emphysematous lymphadenitis in a foal.

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    Mendoza, F J; Perez-Ecija, R A; Estepa, J C

    2011-07-01

    Emphysema of lymph nodes is a rare finding that has been described in different anatomical locations and related to specific diseases in different animal species. Herein is described a foal with Rhodococcus equi infection that presented with emphysema and granulomatous inflammation of the bronchial and mediastinal lymph nodes. This is the first report of emphysematous lymphadenitis in a horse.

  8. Emphysematous pyelonephritis: a review of six cases.

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    Ali, Sohrab Naushad; Ahmed, Niqad; Naushad, Aymon; Naushad, Mian

    2014-01-01

    Emphysematous pyelonephritis is a severe life threatening necrotising infection of the renal parenchyma. The infection most commonly occurs in the diabetic population, often associated with the organism E. coli Emphysematous pyelonephritis differs from standard pyelonephritis by the bacterial liberation and accumulation of gas in the surrounding tissues. The condition is rarely encountered in clinical practice and since the first description by Kelly et al in 1898, approximately 200 cases have been reported in the literature. The case series examines our experience with six diagnosed cases of emphysematous pyelonephritis over a one year period. All patients were female, the mean age of presentation being 53 years. Of the six patients, five were diabetics with hypertension, the one exception being a non-diabetic patient who had undergone renal exploration in the past. Computed tomography confirmed the diagnosis in all patients except one which was confirmed during renal exploration. Urine culture was positive for E. coli in two patients. Emphysematous pyelonephritis which used to be a rare disease is now being more readily diagnosed. The cases were diagnosed at a late stage making its conservative management not feasible

  9. Bilateral Psoas Muscle Abscess Associated with Emphysematous Cystitis

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    Jae-Ki Choi

    2015-01-01

    Full Text Available Psoas muscle abscess associated with emphysematous urinary tract infection is very rare. There were very few reports about urinary tract infections such as renal abscess, perinephric abscess, and emphysematous pyelonephritis complicated with psoas muscle abscess; however, psoas muscle abscess associated with emphysematous cystitis has not yet been reported. Here, we report a case of bilateral posas muscle abscess following emphysematous cystitis in an 81-year-old nondiabetic man, who was treated successfully with prolonged antibiotic therapy and supportive care. Early recognition of psoas muscle abscess can prevent aggressive interventional procedure and warrant good prognosis.

  10. Emphysematous cholecystitis successfully treated by laparoscopic surgery

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    Katagiri, Hideki; Yoshinaga, Yasuo; Kanda, Yukihiro; Mizokami, Ken

    2014-01-01

    Emphysematous cholecystitis (EC) is an uncommon variant of acute cholecystitis, which is caused by secondary infection of the gallbladder wall with gas-forming organisms. The mortality rate of EC is still as high as 25%. Emergency surgical intervention is indicated. Open cholecystectomy has been traditionally accepted as a standard treatment for EC. We present a case of EC successfully treated by laparoscopic surgery. Laparoscopic cholecystectomy for EC is considered to be safe and effective when indicated. PMID:24876461

  11. Emphysematous pancreatitis: The utility of CT

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    Jerbi Omezzine, Saida [Department of Radiology, University Hospital Tahar Sfar, Mahdia 5100 (Tunisia)], E-mail: saidajerbi@topnet.tn; Hmida, Naceur; Adel Hamza, Hassine [Department of Radiology, University Hospital Tahar Sfar, Mahdia 5100 (Tunisia)

    2009-05-15

    Emphysematous pancreatitis is a rare variant of severe acute pancreatitis characterized by gas formation within and around the pancreas. Early radiology detection of retroperitoneal gas in patients with pancreatitis is important in view of the high morbidity and mortality associated with this condition. Computed tomography is the imaging modality of choice. It is both highly sensitive and specific in the detection of abnormal gas and is well-suited to reliably depict the anatomical location and extent of the gas.

  12. Emphysematous pyelonephritis: clinical characteristics and prognostic factors.

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    Lu, Yu-Chuan; Chiang, Bing-Juin; Pong, Yuan-Hung; Chen, Chung-Hsin; Pu, Yeong-Shiau; Hsueh, Po-Ren; Huang, Chao-Yuan

    2014-03-01

    Emphysematous pyelonephritis is a severe necrotizing infection of the renal parenchyma and perirenal tissues that is caused by gas-producing bacterial pathogens. The aim of the present study was to determine the clinical characteristics and prognostic factors of patients with emphysematous pyelonephritis. We retrospectively analyzed the clinical and laboratory data, imaging findings, and outcomes of 32 patients with emphysematous pyelonephritis. Receiver operating characteristic curve analysis was carried out on variables that were significantly associated with patient mortality. The overall survival rate was 87.5% (28/32). Escherichia coli (43.6%) was the most common organism cultured from urine and blood specimens. Hypoalbuminemia, shock as the presenting feature, bacteremia, need for hemodialysis and polymicrobial infection were significantly more common in cases resulting in death. The area under the receiver operating characteristic curve was 0.96. The cut-off point determined by the maximum Youden index (0.93) for three of these five factors yielded a sensitivity of 1.00 and specificity of 0.93. Shock as an initial presentation (P = 0.039) and polymicrobial infection (P = 0.010) were significantly associated with poor outcome. There were no significant differences in the clinical or laboratory features of the patients who did or did not undergo nephrectomy. Hypoalbuminemia, shock as an initial presentation, bacteremia, indications for hemodialysis and polymicrobial infection represent prognostic factors for mortality in patients with emphysematous pyelonephritis. Patients presenting with more than two of these prognostic factors carry the highest risk of mortality, and they require timely diagnosis and aggressive management. © 2013 The Japanese Urological Association.

  13. [Emphysematous gastritis secondary to gastric mucormycosis].

    Science.gov (United States)

    Alvarado-Lezama, Julio; Espinosa-González, Omar; García-Cano, Eugenio; Sánchez-Córdova, Gabriela

    2015-01-01

    Mucormycosis is a rare fungal infection of the mucorales order, which affects mostly immunocompromised patients. The association with emphysematous gastritis is rare and often fatal produced by gas -forming bacteria. We report the case of a trauma patient with type 1 diabetes mellitus, and diabetic ketoacidosis complicated with gastric mucormycosis associated with emphysematous gastritis. A male aged 32 who is involved in a car accident, who suffered head trauma, is admitted to the Intensive Care Unit, presenting diabetic ketoacidosis and upper gastrointestinal bleeding. An endoscopy was performed and an erosive esophagitis Class C, ischemia and gastric necrosis was found. A computed tomography scan showed emphysematous gastritis and gastric necrosis. He underwent total gastrectomy with a histopathology report of gastric mucormycosis. After the surgical procedure the patient died because of sepsis secondary to pulmonary mucormycosis Mucormycosis is a rare fungical disease which infrequently affects the gastrointestinal tract, being the stomach the most affected site. The mortality is high if the diagnosis is not done promptly and appropriate treatment is given. Suspecting its existence is necessary in patients with immunocompromised status to diagnose and provide timely treatment to increase survival, because of its high mortality. Copyright © 2015. Published by Masson Doyma México S.A.

  14. Emphysematous cystitis in a patient with type-2 diabetes mellitus

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    Prathosh Gangadhar

    2011-01-01

    Full Text Available Emphysematous cystitis is a relatively rare clinical entity caused by gas-fermenting bacteria or fungus. Presentation is often nonspecific and imaging is the best diagnostic modality. We report a case of a 45-year-old male who presented with fever, dysuria, and pneumaturia, and was found to have emphysematous cystitis.

  15. SIMULTANEOUS OCCURANCE OF EMPHYSEMATOUS PYELONEPHRITIS AND EMPHYSEMATOUS CHOLECYSTITIS IN AN UNCONTROLLED TYPE 2 DIABETIC: A CASE REPORT

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    Savitri

    2015-04-01

    Full Text Available Emphysematous pyelonephritis a life - threatening, fulminant, necrotizing upper urinary tract infection associated with gas within the kidney . W hich is a rare condition. Only 1 - 2 cases per year are encountered in a urological department in the United States. Emphysematous cholecystitis is a variant of acute cholecystitis which is generally caused by gas - forming organisms. This condition d evelops in approximately 1% of all cases of acute cholecystitis. Compared with typical acute pyelonephritis and typical acute cholecystitis , emphysematous pyelonephritis and emphysematous cholecystitis is associated with much higher rates of morbidity and significantly increased rates of mortality (15 - 25%. Individually these conditions are less reported, there by, Simultaneous occcurance of emphysematous pyelonephritis and emphysematous cholecystitis are uncommon and only two cases are reported in literature . As clinical course of both entities are individually severe and life - threatening if not recognized and treated promptly, so in a case of simultaneous occurrence, early diagnosis is to be made and a potentially devastating outcome is to be avoided. We present a case of emphysematous pyelonephritis with emphysematous cholecystitis and pneumoperitoneum in a middle aged uncontrolled diabetic patient and discussed etio - pathogenesis, classification and therapy of these entities.

  16. Glassfiber post: an alternative for restoring grossly decayed primary incisors.

    Science.gov (United States)

    Mehra, Manjul; Grover, Rashu

    2012-05-01

    Restoration of primary incisors, which have been severely damaged by rampant caries or trauma, is a difficult task for the pediatric dentist. With the introduction of new adhesive systems and restorative materials, alternative approaches for treating these teeth have been proposed. This paper discusses the restoration of carious primary maxillary incisors using composite resin restoration reinforced with fiberglass post. Two case reports are presented here to describe the procedure. Over a 1 year period, the crowns have demonstrated good retention and esthetic results. How to cite this article: Mehra M, Grover R. Glassfiber Post: An Alternative for Restoring Grossly Decayed Primary Incisors. Int J Clin Pediatr Dent 2012;5(2):159-162.

  17. Emphysematous and xanthogranulomatous pyelonephritis: rare diagnosis

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    Lya Duarte Ramos

    2010-08-01

    Full Text Available Pyelonephritis is a pyogenic infection of renal parenchyma that involves the renal pelvis. It is generally of easy diagnosis. The present case report aims to describe two different manifestations of this infection: xanthogranulomatous pyelonephritis and emphysematous pyelonephritis, which have poor prognosis and require a more effective treatment. The two cases were women in the fiftieth and sixtieth decade of life, with diabetes mellitus and history of weight loss. The diagnosis of the renal infection was established through computed tomography and the treatment was based in surgical procedure, with favorable outcome.

  18. Anaesthetic Management of Nephrectomy for Emphysematous Pyelonephritis

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    N Dua

    2008-01-01

    Full Text Available Emphysematous pyelonephritis (EPN is a serious and often life threatening infection of the renal and perirenal tissues. The characteristic feature of this infection is the presence of gas within the kidney and perinephric tissues. The triad of symptoms of fever, flank pain and pyuria, especially in a diabetic female patient which did not respond promptly to conventional antibiotic therapy raised the possibility of EPN. CT scan established the diagnosis and the line of management. After failing medical management, uncontrolled frustrating hyperglycemia with fear of septice-mia, nephrectomy was done in life threatening fulminant infection of the kidney.

  19. Emphysematous and xanthogranulomatous pyelonephritis: rare diagnosis

    Directory of Open Access Journals (Sweden)

    Lya Duarte Ramos

    Full Text Available Pyelonephritis is a pyogenic infection of renal parenchyma that involves the renal pelvis. It is generally of easy diagnosis. The present case report aims to describe two different manifestations of this infection: xanthogranulomatous pyelonephritis and emphysematous pyelonephritis, which have poor prognosis and require a more effective treatment. The two cases were women in the fiftieth and sixtieth decade of life, with diabetes mellitus and history of weight loss. The diagnosis of the renal infection was established through computed tomography and the treatment was based in surgical procedure, with favorable outcome.

  20. Glassfiber Post: An Alternative for Restoring Grossly Decayed Primary Incisors

    Science.gov (United States)

    Grover, Rashu

    2012-01-01

    ABSTRACT Restoration of primary incisors, which have been severely damaged by rampant caries or trauma, is a difficult task for the pediatric dentist. With the introduction of new adhesive systems and restorative materials, alternative approaches for treating these teeth have been proposed. This paper discusses the restoration of carious primary maxillary incisors using composite resin restoration reinforced with fiberglass post. Two case reports are presented here to describe the procedure. Over a 1 year period, the crowns have demonstrated good retention and esthetic results. How to cite this article: Mehra M, Grover R. Glassfiber Post: An Alternative for Restoring Grossly Decayed Primary Incisors. Int J Clin Pediatr Dent 2012;5(2):159-162. PMID:25206160

  1. Extensive emphysematous pyelonephritis in association with hepatic portal venous gas and emphysematous gastritis: A rare case

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    Vikram Prabha

    2014-01-01

    Full Text Available Although emphysematous pyelonephritis is recognized from more than hundred years, the etiology is still controversial. Glucose fermentation is the proposed possible mechanism for gas fermentation. The extension of emphysematous pyelonephritis into portal vein and stomach is a rare condition. We present a 52-year-old woman with uncontrolled diabetes who was admitted with sepsis and left flank pain. She was investigated, and results revealed gas in the left renal system with extension into portal vein and stomach. She was resuscitated and managed with percutaneous drainage, DJ stenting, and broad spectrum antibiotics, she did not improve and hence nephrectomy was done. Prompt diagnosis, early and aggressive treatment is crucial because of high mortality.

  2. Emphysematous liver abscess in diabetic patient: two cases report

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    Rhim, Hyun Chul; Koo, Ja Hong; Kim, Sung Tae; Kim, Yong Soo; Koh, Byung Hee; Cho, On Koo [College of Medicine, Hanyang University, Seoul (Korea, Republic of)

    1995-07-15

    There has not been any report on massive air-containing liver abscess in diabetic patients, although emphysematous cholecystitis or pyelonephritis is a well-known complication in them. Authors report two cases of emphysematous liver abscess in diabetic patient, which showed typical findings of massive air-containing hepatic abscess on ultrasonography and computed tomography, but very poor prognosis in spite of immediate and successful percutaneous drainage procedure.

  3. Emphysematous pyelonephritis with calculus: Management strategies

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    Tanmaya Goel

    2007-01-01

    Full Text Available Objective: Emphysematous pyelonephritis (EPN with calculus is well recognized but with very few reports on its treatment. Our aim is to elucidate our experience in its successful management. Materials and Methods: Over four years, we diagnosed seven cases (eight renal units of EPN, out of which two patients (three renal units had EPN with urinary calculi. After the initial conservative management of EPN, the stones were tackled appropriately. Results: EPN was initially managed effectively with antibiotics and supportive care. Once the patient was stable, the stones were cleared in a step-wise fashion. The associated postoperative complications were also tackled efficiently with preservation of renal function. Conclusion: In EPN with stones, nephrectomy is not the sole option available and they can be effectively managed with open / endoscopic measures.

  4. Emphysematous Pancreatitis. Radiological Curiosity or a Cause for Concern?

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    Jai Dev Wig

    2008-03-01

    Full Text Available Context Emphysematous pancreatitis is a rare, potentially fatal variant of severe acute pancreatitis with gas in the pancreatic bed. There are isolated case reports describing this condition. Objective This report summarizes our experience with the management of this condition in order to compare its clinical characteristics, microbiological and radiological features, surgical management and the outcome of patients with emphysematous pancreatitis and nonemphysematous infected pancreatic necrosis. Setting The hospital records of the patients who underwent necrosectomy for infected pancreatic necrosis between 2002 and 2006 were reviewed. Patients Fifty-seven patients were identified: 11 of them (19.3% had gas in and around the pancreas on computed tomography and 46 (80.7% had non-emphysematous infected pancreatic necrosis. Main outcome measures The clinical characteristics and the hospital course of the two groups of patients were compared. Results The mean age of 11 patients with emphysematous pancreatitis was 34.0±11.5 years and alcohol was the most common etiology (54.5%. The median computed tomography severity index was 10. All 11 patients with emphysematous pancreatitis had growth of organisms on culture of fine needle aspiration or pancreatic tissue obtained at surgery, with Escherichia coli in all of them. Polymicrobial infection was seen in 5 (45.5% of them. In comparing patients having emphysematous pancreatitis with those having non-emphysematous infected necrosis, there was no significant difference in the severity of the disease (P=0.319, time to surgical intervention (P=0.553, incidence of organ failure (P=0.297, hospital stay (P=0.580 or mortality rate (P=0.739. The total number of locoregional complications was significantly higher in patients with emphysematous pancreatitis (P=0.049. However, when compared separately, the incidence of enteric fistula, bleeding, intraabdominal collections and wound complications were similar in the

  5. Emphysematous pyelonephritis: A single center study

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    R Fatima

    2013-01-01

    Full Text Available We present our experience of 22 cases of emphysematous pyelonephritis (EPN treated from 1996 to 2012. Medical records were analyzed retrospectively for demographic profile, presence and duration of diabetes mellitus, and mode of clinical presentation. EPN was diagnosed based on demonstration of intra-renal gas by plain X-ray, ultrasound, and/or computed tomography (CT scan. Details of medical treatment, reason for surgical intervention, and final outcome were recorded. Univariate analysis was performed to identify risk factors for mortality and P value of less than 0.05 was taken as significant. Twenty-two cases (6 males, 16 females of EPN were diagnosed. Seven cases presented with acute pyelonephritis, seven cases with urosepsis, and the remaining eight patients with multi-organ dysfunction. CT grading of EPN was class IV in three, class III in four, class II in 14, and class I in one. All were initially managed medically with parenteral antibiotics. Ten patients needed additional surgical intervention. The overall survival rate was 86.3% (19/22. Among the risk factors analyzed higher CT grade, altered sensorium and thrombocytopenia were significantly associated with mortality. We conclude that a more conservative approach in managing EPN has become the standard of care. Patients having high CT grade of lesions (III and IV with altered sensorium and thrombocytopenia at presentation are more likely to die due to the disease and may be better managed by an aggressive surgical plan.

  6. A Rare Case of Septic Shock Secondary to Emphysematous Hepatitis.

    Science.gov (United States)

    Nada, Khaled M; El Husseini, Ibrahim; Abu Hishmeh, Mohammad E; Shah, Neerav S; Ibragimova, Nadezhda; Basir, Riyad

    2017-01-01

    To describe a case of emphysematous hepatitis which is a rare clinical entity, characterized by a fatal, rapidly progressive infection of the liver with a radiological appearance simulating emphysematous pyelonephritis and to help provide more data about the causative organisms and precipitating factors of this pathology. Relevant literature was reviewed and, to the best of our knowledge, there is limited data regarding the pathogenesis, causative organisms, and management of this condition. Emphysematous hepatitis is a rapidly progressive infection that can be fatal in the absence of appropriate therapeutic intervention. Initial clinical manifestations are usually subtle and thus high clinical suspicion is required for early diagnosis and management of this condition to help decrease the mortality rates.

  7. Emphysematous osteomyelitis: a case report and review of the literature.

    Science.gov (United States)

    Luey, Christopher; Tooley, Debbie; Briggs, Simon

    2012-03-01

    We report the case of a 15-year-old girl with pelvic and sacral emphysematous osteomyelitis caused by Fusobacterium necrophorum. This infection was cured following four surgical procedures and 4 weeks of intravenous then 4 weeks of oral antibiotics. We review our case alongside the 24 previously reported cases of emphysematous osteomyelitis in the literature. The 25 cases include 15 monomicrobial and 10 polymicrobial infections. The causative organism(s) in all but three cases included an anaerobe or a member of the Enterobacteriaceae family. A significant underlying comorbidity was reported in 18 cases. At least 15 cases required one or more surgical procedures. There was a significant associated mortality with eight (32%) patients dying in hospital at 7 to 56 days after the diagnosis of emphysematous osteomyelitis.

  8. Emphysematous pyometra secondary to Enterococcus avium infection in a dog.

    Science.gov (United States)

    Chang, An-Chi; Cheng, Ching-Chang; Wang, Hsien-Chi; Lee, Wei-Ming; Shyu, Ching-Lin; Lin, Cheng-Chung; Chen, Kuan-Sheng

    2016-06-16

    A 5-year-old female intact Mastiff dog was presented with a history of vaginal discharge for 1 day. Physical examination revealed a sanguineo-purulent vaginal discharge and systemic inflammatory response syndrome. Abdominal radiographs showed several dilated and gas- filled tubular loops. The differential diagnoses included emphysematous pyometra or small intestinal mechanical ileus. Surgical exploration of the abdomen demonstrated a severely dilated and gas-filled uterus, and emphysematous pyometra was confirmed. The patient's clinical signs resolved after ovariohysterectomy. Histopathology revealed mild endometrial cystic hyperplasia with infiltration of inflammatory cells in the superficial endometrial epithelia. Enterococcus avium, an α-hemolytic gram-positive coccus, was isolated from the uterus. This paper highlights the radiographic features of emphysematous pyometra and a pathogen that has never been reported to be associated with canine pyometra previously.

  9. Emphysematous pyelonephritis presenting as a sonologically absent kidney

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    Chirag Patel

    2015-01-01

    Full Text Available Emphysematous pyelonephritis is an acute necrotizing infection of the kidney caused by gas-producing organisms. It is being increasingly recognized as an underlying cause of sepsis. We present a case of emphysematous pyelonephritis where the affected kidney was filled with extensive gas. This made the detection of the kidney difficult by ultrasound. Also, this case presents the dilemma of managing a septic patient medically and the risks entailed in surgical intervention in such cases. Most often, these patients have underlying diabetes mellitus with underlying co-morbidities, making indicated surgical management difficult as illustrated by our patient.

  10. Recommended Initial Antimicrobial Therapy for Emphysematous Pyelonephritis

    Science.gov (United States)

    Lu, Yu-Chuan; Hong, Jian-Hua; Chiang, Bing-Juin; Pong, Yuan-Hung; Hsueh, Po-Ren; Huang, Chao-Yuan; Pu, Yeong-Shiau

    2016-01-01

    Abstract The aim of this study was to investigate the profiles of pathogens and patterns of antibiotic resistance of emphysematous pyelonephritis (EPN), offering recommendations for initial antibiotic treatment. Between January, 2001, and November, 2014, demographic data, presenting clinical features, management strategies, and treatment outcomes of 51 patients with EPN were retrospectively reviewed, analyzing microbiological characteristics of causative pathogens and patterns of antibiotic resistance. Overall survival rate was 90.2% (46/51). Pathogens isolated most frequently were Escherichia coli (49.0%), Klebsiella pneumoniae (19.6%), and Proteus mirabilis (17.7%). Approximately 24% of E coli isolates and 22% K pneumoniae isolates were resistant to fluoroquinolones. Improper empiric antibiotic use (P = 0.02) and third-generation cephalosporin-resistant pathogens (G3CRP) (P = 0.01) were significantly more common in cases of patient fatality. Prior hospitalization and antibiotic use within past year (P = 0.03), need for emergency hemodialysis (P = 0.03), and development of disseminated intravascular coagulation (DIC) (P = 0.03) were factors correlating significantly with microbial resistance to third-generation cephalosporins. The area under the receiver operating characteristic curve was 0.91. The cut-off point determined by the maximum Youden index for 2 of these 3 factors yielded a sensitivity of 0.8 and specificity of 0.93. Third-generation cephalosporins are recommended as initial treatment of EPN. In patients with histories of prior hospitalization and antibiotic use and in those needing emergency hemodialysis or developing DIC, carbapenem is the empiric antibiotic of choice. Patients presenting with 2 or more factors carry the highest risk of G3CRP involvement. Fluoroquinolone and gentamicin should be avoided. PMID:27227920

  11. EMPHYSEMATOUS CYSTITIS : CASE REPORT AND REVIEW OF LITERATURE

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    Altaf

    2013-10-01

    Full Text Available ABSTRACT : Background: Emphysematous cystitis is defined by the presence of gas in the urinary bladder wall in the absence of previous instrumentation or surgery or diverticular diseases of colon or malignancies. It complicates uri nary tract infections especially in diabetic patients. AIMS: We report a case of 65yr old, poorly controlled, diabetic male who presented with dysuria, fever and hematuria and was incidentally found to have Klebsiella pneumoniae emphysematous cystitis that resolved with antibiotic treatment and bladder drainage. METHODS AND RESULTS: A 65 - year - old man was admitted to the emergency department with retention of urine. There was history of fever since 2 days. There was no history of previous retention of urine. An ultrasound examination of abdomen and pelvis showed gas in the bladder which was confirmed by computed tomography (CT, which demonstrated intramural gas in the urinary bladder, which suggested a diagnosis of emphysematous cystitis. The treatment was b ased on an antibiotics associated with a bladder drainage. CONCLUSION: Every diabetic patient with a urinary tract infection who seems to be severely ill should have an abdominal X - ray or CT scan as a minimal screening tool to detect emphysematous complica tions

  12. Percutaneous drainage of emphysematous cholecystitis associated with pneumoperitoneum

    NARCIS (Netherlands)

    Zeebregts, CJ; Wijffels, RTM; de Jong, KP; Peeters, PM; Slooff, MJH

    1999-01-01

    Emphysematous cholecystitis, a relatively rare variant of acute cholecystitis, is associated with high morbidity and mortality rates. In the presence of a concomitant pneumoperitoneum, these rates may be considered even higher, approaching those of perforation of the gallbladder. The first choice of

  13. Emphysematous pyelonephritis (class IIIa) managed with antibiotics alone.

    Science.gov (United States)

    Chauhan, Vivek; Sharma, Rajesh

    2015-08-01

    A 54-year-old male with long-standing diabetes presented with vague left flank pain for 5 days with uncontrolled blood glucose. The patient was commenced on insulin and injectable ceftriaxone empirically, for possibly acute pyelonephritis. Ultrasound examination revealed extensive emphysematous pyelonephritis of upper half of left kidney with involvement of perinephric space. Computed tomography of abdomen confirmed the diagnosis of emphysematous pyelonephritis which was categorised as class IIIa. The recommended treatment for class IIIa emphysematous pyelonephritis is nephrectomy but the patient refused to give consent for surgery or even percutaneous drainage. Thus, the patient was continued on medical management alone and surprisingly showed marked recovery over the next few days. There were no new complications, and the patient was discharged after 2 weeks of antibiotics with 2 more weeks of oral antibiotics. After 4 months, the ultrasound showed normal kidneys. We present this case because it adds to the little existing evidence that conservative management can successfully cure patients with class IIIa emphysematous pyelonephritis, although supplementation with percutaneous drainage would have been better in this case.

  14. Extensive bilateral emphysematous pyelonephritis with calculi managed conservatively with antibiotics and DJ stent

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    Madhulika Mahashabde

    2013-01-01

    Full Text Available Emphysematous pyelonephritis is a life threatening, necrotizing upper urinary tract infection associated with gas within the kidney and/or perinephric space. To prevent mortality from this fulminant infection, early diagnosis is essential. CT scan should be done early in patients with suspected emphysematous pyelonephritis. Here, we present a case of Type II Diabetes Mellitus complicated with left obstructive ureteric calculi, diagnosed on CT scan to have extensive bilateral emphysematous pyelonephritis of class 4. We treated conservatively with antibiotics and DJ stent. The patient responded and a repeat CT scan was done after 4 weeks which showed no evidence of emphysematous pyelonephritis.

  15. Double J stenting: A rewarding option in the management of emphysematous pyelonephritis

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    Debiprasad Das

    2016-01-01

    Conclusion: Emphysematous pyelonephritis can be managed conservatively by DJ stenting, wcich is a less morbid procedure or percutaneous nephrostomy with proper antibiotics and adequate glycemic control.

  16. Emphysematous Eosinophilic Lymphangitis in the Ruminal Submucosa of Cattle.

    Science.gov (United States)

    Ohfuji, S

    2015-11-01

    Twenty cattle (14 Holstein-Friesian, 3 Japanese Black, 3 Aberdeen Angus) ranging in age from 3 months to 8 years exhibited, at slaughter, emphysematous thickening of the ruminal submucosa owing to the appearance of numerous, contiguous, small gas bubbles. Microscopic changes in the ruminal submucosa consisted of (1) multiple cystic (emphysematous) lymphangiectasis that was frequently lined or occluded by granulomatous inflammatory infiltrates including macrophages, multinucleate giant cells, and eosinophils; (2) intralymphatic phagocytosis by macrophages and giant cells of eosinophils that showed positive labeling with the terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end-labeling assay; and (3) an inflammatory infiltrate extending from the area of lymphangitis into surrounding tissue, as well as edema, hemorrhage, fibrin exudation, fibroplasia, or capillary proliferation throughout the lesional submucosa. In addition, 15 (75%) of the cattle had globular leukocyte infiltrates in the mucosal epithelia of the rumen.

  17. Percutaneous drainage of abscess in the treatment of emphysematous pyelonephritis

    Energy Technology Data Exchange (ETDEWEB)

    Jung, Jin Yong; Jeong, Yong Yeon; Kim, Jae Kyu; Park, Seung Jei; Park, Jin Gyoon; Kang, Heoung Keun [Chonnam Univ. School of Medicine, Kwangju (Korea, Republic of); Roh, Byung Suk [Wonkwang Univ. School of Medicine, Iksan (Korea, Republic of)

    1997-02-01

    To assess the usefulness of percutaneous drainage of abscess in the treatment of emphysematous pyelonephritis. Ten cases of nine patients with emphysematous pyelonephritis were percutaneously drained. All were suffering from diabetes mellitus. The procedure was performed under fluoroscopic guidance in nine cases and US guidance in one case in which bilateral multiloculated abscesses were present in the perirenal space. The results were classified as cure, partial success, recurrence, or failure. The mean drainage period and complication were analyzed. Eight cases were cured, and there was one case success. In one case, who had diffuse renal parenchymal destruction without perirenal fluid collection, the treatment failed. The longest drainage period was 45 days, in a case of re-insertion due to incidental catheter removal; the mean was 23 days. Bacteremia in one case was cured with antibiotic therapy which lasted two days. In diabetic patients, percutaneous drainage of obscess is thought to be a safe and effective method for the treatment of emphysematous pyelonephritis, and is one that does not involve diffuse destruction of renal parenchyma.

  18. Emphysematous cystitis: An unusual disease of the Genito-Urinary system suspected on imaging

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    Sarna Pawanjit S

    2004-10-01

    Full Text Available Abstract Emphysematous cystitis is a rare disease entity caused by gas fermenting bacterial and fungal pathogens. Clinical symptoms are nonspecific and diagnostic clues often arise from the unanticipated imaging findings. We report a case of 52-year-old male who presented with fever, dysuria and gross hematuria who was found to have emphysematous cystitis.

  19. Percutaneous drainage in the treatment of emphysematous pyelonephritis: 10-year experience

    Energy Technology Data Exchange (ETDEWEB)

    Chen, M.; Huang, C.; Chou, Y.; Huang, Ch.; Chiang, C.; Liu, G. [Chung-Ho Memorial Hospital, Kaohsiung Medical College, Taiwan (China)

    1997-11-01

    CT is an efficient imaging method for diagnosis, guiding the drainage procedures and monitoring response to percutaneous drainage of emphysematous pyelonephritis. Antibiotic therapy combined with CT guided percutaneous drainage of emphysematous pyelonephritis is an acceptable alternative to antibiotic therapy with surgical intervention. (authors)

  20. Therapeutic potential of growth factors in pulmonary emphysematous condition.

    Science.gov (United States)

    Muyal, Jai Prakash; Muyal, Vandana; Kotnala, Sudhir; Kumar, Dhananjay; Bhardwaj, Harsh

    2013-04-01

    Pulmonary emphysema is a major manifestation of chronic obstructive pulmonary disease (COPD), which is characterized by progressive destruction of alveolar parenchyma with persistent inflammation of the small airways. Such destruction in the distal respiratory tract is irreversible and irreparable. All-trans-retinoic acid was suggested as a novel therapy for regeneration of lost alveoli in emphysema. However, profound discrepancies were evident between studies. At present, no effective therapeutic options are available that allow for the regeneration of lost alveoli in emphysematous human lungs. Recently, some reports on rodent's models have suggested the beneficial effects of various growth factors toward alveolar maintenance and repair processes.

  1. A case of emphysematous pyelonephritis induced by Citrobacter freundii infection

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    Youichi Yanagawa

    2013-01-01

    Full Text Available A 79-year-old female with diabetes mellitus had general fatigue, a high fever and vomiting. A CT revealed acute emphysematous pyelonephritis (EPN. A nephrectomy was performed on the 2 nd hospital day. The results of the blood culture showed the presence of Citrobacter freundii infection. The patient′s post-operative course was uneventful. This case is the second reported case of EPN induced by Citrobacter freundii. Bacteremia induced by Citrobacter freundii infection typically results in a high mortality rate. In this case, the early diagnosis of the EPN using CT and immediate medical treatment, including urgent elective nephrectomy, were key to the favorable outcome.

  2. The emphysematous lung is abnormally sensitive to TRAIL-mediated apoptosis

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    Milot Julie

    2011-08-01

    Full Text Available Abstract Background Alveolar apoptosis is increased in the emphysematous lung. However, mechanisms involved are not fully understood. Recently, we demonstrated that levels of TRAIL receptor 1 and 2, levels of p53, and Bax/Bcl-xL ratio were elevated in the lung of subjects with emphysema, despite smoking cessation. Thus, we postulate that due to chronic pulmonary oxidative stress, the emphysematous lung would be abnormally sensitive to TRAIL-mediated apoptosis. Methodology A549 cells were exposed to rTRAIL, cigarette smoke extract, and/or H2O2 prior to caspase-3 activity measurement and annexin V staining assessment. In addition, freshly resected lung samples were obtained from non-emphysematous and emphysematous subjects and exposed ex vivo to rTRAIL for up to 18 hours. Lung samples were harvested and levels of active caspase-3 and caspase-8 were measured from tissue lysates. Results Both cigarette smoke extract and H2O2 were able to sensitize A549 cells to TRAIL-mediated apoptosis. Moreover, following exposure to rTRAIL, caspase-3 and -8 were activated in lung explants from emphysematous subjects while being decreased in lung explants from non-emphysematous subjects. Significance of the study Alveolar sensitivity to TRAIL-mediated apoptosis is strongly increased in the emphysematous lung due to the presence of oxidative stress. This might be a new mechanism leading to increased alveolar apoptosis and persistent alveolar destruction following smoking cessation.

  3. PENATALAKSANAAN ANESTESI PADA BAYI DENGAN EMPHYSEMATOUS BULLOSA KONGENITAL

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    Ni Made Supradnyawati

    2015-05-01

    Full Text Available Emphysematous bullosakongenital merupakan penyebab distress respirasi yang jarang dijumpai, umumnya pada usia neonatus sampai enam bulan pertama. Insiden dilaporkan sebesar 1:70.000- 1:90.000 kelahiran hidup dan biasanya disertai dengan kelainan kongenital lainnya. Etiologi tidak diketahui, namun diduga terjadi akibat displasi kartilago bronkial. Hiperinflasi dan udara yang terperangkap secara progresif akan menimbulkan ekspansi paru ke sisi yang sehat, mendesak parenkim yang sehat, pergeseran mediastinum, dan mengganggu aliran darah balik vena.Secara klinis ditandai dengan distress napas yang semakin memburuk akibat akumulasi progresif udara pada lobus yang sakit. Kami melaporkan kasus pada bayi perempuan berusia 1 bulan, dengan keluhan sesak napas yang semakin memberat sejak 1 minggu sebelumnya. Diagnosis ditegakkan dari klinis, foto dada, dan computed tomography scan dada. Tindakan torakotomi lobektomi lobus medius telah dilakukan untuk menghilangkan lesi desak ruang sekaligus melindungi jaringan paru fungsional.Penatalaksanaan anestesi menitikberatkan pada saat induksi. Pemberian ventilasi manual secara gentle, menghindari pemberian ventilasi tekanan positif dan penggunaan N2O sampai torakotomi dilakukan untuk mencegahpeningkatan volume lobus yangmengalami emphysematous, serta pemberian analgesi perioperatif yang adekuat.Bila terjadi ekspansi lobus emphysematoussecara tiba-tiba, seorang dokter bedah harus siap melakukan torakotomi dengan segera. Pasien ini menunjukkan perkembangan yang baik dan akhirnya pulang pada hari ke-5 pascaoperasi. [MEDICINA 2014;45:134-8]  

  4. Sleep-related hypoxemia aggravates systematic inflammation in emphysematous rats

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    FENG Jing; Ambrose An-Po Chiang; WU Qi; CHEN Bao-yuan; CUI Lin-yang; LIANG Dong-chun; ZHANG Ze-li; YAO Wo

    2010-01-01

    Background Sleep disturbance is common in patients with emphysema. This study aimed to develop a novel model of sleep-related hypoxemia (SRH) in emphysema (SRHIE) with rats, and to explore the inflammatory status of SRHIE in lung, liver, pancreas, carotid artery and whole blood.Methods Seventy-five male Wistar rats were assigned to 5 groups with 15 per group according to the exposure conditions. The protocols varied with the degree of hypoxia exposure and severity of pre-existing emphysema caused by cigarette smoke exposure: (1) SRH control (SRHCtrl) group, sham smoke exposure (smoke exposure, exposed to smoke of 15 cigarettes twice everyday, 16 weeks) and SRH exposure (12.5% O2, 3 hours, SRH exposure, divide total hypoxia time (1.5 hours or 3 hours) into 4 periods evenly (22.5 minutes or 45 minutes) and distribute these hypoxia periods evenly into physiological sleep time of rats identified by electroencephalogram, week 9 to week 16); (2) Emphysema control (ECtrl) group, smoke exposure and sham SRH exposure (21% O2, 3 hours); (3) Short SRH in emphysema (SRHShort) group, smoke exposure and short SRH exposure (12.5% O2, 1.5 hours); (4) Mild SRH in emphysema (SRHMild) group,smoke exposure and mild SRH exposure (15% O2, 3 hours); (5) Standard SRH in emphysema (SRHStand) group, smoke exposure and SRH exposure (12.5% O2, 3 hours). ECtrl, SRHShort, SRHMild and SRHStand groups were groups with emphysematous rats. Two days before the end of exposure, 5 rats in each group were randomly selected for arterial blood gas analysis. In the rest 10 rats in each group, we obtained blood samples and bronchoalveolar lavage fluid (BALF)for routine tests. We also obtained tissue blocks of lung, liver, pancreas, and right carotid artery for pathologic scoring and measurements of liver oxidative stress (measuring hepatic oxidative stress enzymes, superoxide dismutase (SOD) activity, catalase (CAT) activity and malondialdehyde (MDA) concentration).Results Emphysematous groups had higher

  5. Post-ERCP Emphysematous Cholecystitis in a Young Woman: A Rare and Potentially Fatal Complication

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    Roisin Stack

    2017-01-01

    Full Text Available A 45-year-old woman with suspected Functional Biliary Sphincter Disorder (FBSD developed Clostridium perfringens related emphysematous cholecystitis after ERCP. A low index of suspicion for emphysematous cholecystitis in this young, otherwise healthy woman led to a significant delay in making the correct diagnosis, and air in the gallbladder was wrongly attributed to a possible gallbladder perforation. ERCP is associated with significant risks, particularly in patients with FBSD, where diagnostic uncertainty renders the balance of risk versus benefit even more critical. Post-ERCP emphysematous cholecystitis secondary to Clostridium perfringens is a rare but potentially fatal complication.

  6. Emphysematous Cystitis During Treatment of Suspected Nonconvulsive Status Epilepticus in Type 2 Diabetic Patient

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    Chung-Jung Wu

    2011-06-01

    Full Text Available Emphysematous cystitis is a rare disorder and complication of urinary tract infection (UTI, characterized by spontaneous gas formation in the urinary bladder because of bacterial fermentation. We present a case of emphysematous cystitis during treatment of suspected nonconvulsive status epilepticus in a patient with Type 2 diabetes mellitus. The patient recovered satisfactorily after 27 days of hospitalization. Treatment of emphysematous cystitis consisted of adequate urinary drainage, empirical antibiotic therapy, and strict blood glucose control. Diabetic patients are susceptible to an increased incidence of UTI and its complications. An early and correct diagnosis of UTI in diabetic patients followed by adequate treatment will prevent the disease from developing into a serious or life-threatening condition, such as emphysematous cystitis, or progressing to septic shock.

  7. Image-guided percutaneous drainage of an emphysematous bulla with a fluid level

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    Kalra Naveen

    2010-01-01

    Full Text Available We report here a case of a large emphysematous bulla with a fluid level that was managed successfully by percutaneous catheter drainage in a 50 year-old man with chronic obstructive airway disease.

  8. [Emphysematous pyelonephritis. Epidemiological, clinical, biological, bacteriological, radiological, therapeutic and prognostic features. Retrospective study of 30 cases].

    Science.gov (United States)

    Cherif, Mohamed; Kerkeni, Walid; Bouzouita, Abderrazak; Selmi, Mohamed Slim; Derouiche, Amine; Ben Slama, Mohamed Riadh; Chebil, Mohamed

    2012-10-01

    Emphysematous pyelonephritis is an uncommon, necrotizing bacterial infection of the kidney. It is a severe, life threatening affection. To study the epidemiological, clinical, biological, bacteriological and radiological features of this affection, and to describe its therapeutic management and prognostic characteristics. We conducted a retrospective study including 30 patients who were treated for an emphysematous pyelonephritis, in Charles Nicolle hospital department of urology, from 1987 to 2009. Emphysematous pyelonephritis generally affects adults. It is especially favored by diabetes and urinary tract obstruction. Escherichia coli is the main causative agent. Uroscan is the key of diagnosis. It is both medical and surgical emergency; the treatment combines intensive care with appropriate antibiotics and often drainage. Nephrectomy may be necessary from the outset, or after drainage failure. Prognosis is poor, with a high mortality rate (23 %), in our series. Management of emphysematous pyelonephritis poses real problems. This affection is still threatening, despite of advances in intensive care.

  9. Concurrent emphysematous pyelonephritis and thigh necrotizing fasciitis after intramuscular administration of diclofenac

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    Fateme Shamekhi Amiri

    2014-01-01

    Full Text Available Necrotizing fasciitis (NF is a rapidly progressive, life-threatening soft tissue infec-tion. NF may result from any injury to the skin or from hematogenous spread. However, con-current emphysematous pyelonephritis and necrotizing fasciitis of the left thigh has not been reported. We report a case of emphysematous pyelonephritis and necrotizing fasciitis of the left thigh after intramuscular administration of diclofenac that improved with aggressive management including broad-spectrum antibiotics, nephrectomy and surgical intervention.

  10. Concurrent emphysematous pyelonephritis and thigh necrotizing fasciitis after intramuscular administration of diclofenac.

    Science.gov (United States)

    Amiri, Fateme Shamekhi; Foroughi, Alireza

    2014-11-01

    Necrotizing fasciitis (NF) is a rapidly progressive, life-threatening soft tissue infection. NF may result from any injury to the skin or from hematogenous spread. However, con-current emphysematous pyelonephritis and necrotizing fasciitis of the left thigh has not been reported. We report a case of emphysematous pyelonephritis and necrotizing fasciitis of the left thigh after intramuscular administration of diclofenac that improved with aggressive management including broad-spectrum antibiotics, nephrectomy and surgical intervention.

  11. Emphysematous Pyelonephritis Presenting as Necrotizing Fasciitis of the Leg

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    Yu-Xiong Ye

    2009-03-01

    Full Text Available We report a 50-year-old man with poorly controlled diabetes mellitus who presented with a painful, swollen right leg. He had also experienced right flank pain for 1 week prior to admission. Physical examination was notable for tenderness over the right flank. The right leg was diffusely swollen and exquisitely tender to touch, with palpable crepitance. Laboratory tests revealed leukocytosis and pyuria. Computed tomography showed a right ureteral stone with hydronephrosis and characteristic findings of emphysematous pyelonephritis. Furthermore, a right perirenal gas-forming abscess with extension to the right leg was noted. The patient was successfully treated with antibiotic therapy, aggressive control of blood sugar, percutaneous drainage of the hydronephrosis and perirenal abscess, and aggressive debridement of the leg.

  12. Emphysematous cystitis: A rare disease of Genito-urinary system

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    Shilpi Singh

    2015-01-01

    Full Text Available Context: Emphysematous cystitis (EC is a rare infection of the urinary tract that results in gas production in the bladder. It is more common in diabetic and female patients, and can be associated with more serious complications, including pyelonephritis. Case Report: We describe a case of recurrent bacterial cystitis caused by Escherichia coli (E. coli. An incidental finding in our patient of pneumaturia on computed tomography (CT scan prompted further work-up. Differential diagnoses for pneumaturia include infection, trauma, and fistula, most commonly colovesicular. The patient history ruled out trauma and CT scanning ruled out a fistula; culture of the urine then showed a bacterial load greater than 100,000 E. coli/mL. The patient was then diagnosed with EC. She was treated with ceftriaxone and released in stable condition. Conclusion: The literature was scarce when it came to diagnoses of EC based on bacterial load. We present this case to increase health care providers′ awareness of recurrent EC with a urine culture bacterial load greater than 100,000 E. coli/mL.

  13. [Prognostic factors of morbimortality in patients with emphysematous pyelonephritis].

    Science.gov (United States)

    Torres-Mercado, León Octavio; García-Padilla, Miguel Ángel; Serrano-Brambila, Eduardo; Maldonado-Alcaraz, Efraín; López-Sámano, Virgilio Augusto; Montoya-Martínez, Guillermo; Moreno-Palacios, Jorge

    2016-01-01

    Emphysematous pyelonephritis (EPN) is a severe infection of the urinary tract, caused by gas accumulation within the collecting system, the renal parenchyma, and/or the perirenal tissue. The cause of this infection is not known at all; however, it has been suggested that it is produced by the glucose fermentation provoked by enterobacteriaceae or anaerobic organisms. Our objective was to evaluate the predictors of morbidity and mortality in patients diagnosed with EPN. It was carried out a historical cohort study of patients diagnosed with EPN in our hospital from March 2005 to December 2014. Patients with adverse outcome were identified. We defined adverse outcome as patients requiring stay in intensive care unit, who presented nephrectomy and/or who died. A multiple regression analysis was conducted to establish the relation of each clinical factor with the adverse outcome. 73 records were included for analysis, 48 were women (65.8 %) and 25 men. Diabetes, urolithiasis, E. coli infection and septic shock occurred in 68.5, 68.5, 63, and 15.1 %, respectively. We found that leukocytosis ≥12 000 µl (OR 43.65, 95 % CI 2.36-805, p <0.001), thrombocytopenia ≤120 000 µl (OR 363, 95 % 9.2-14208, p <0.0001), and Huang's radiological class 3 (OR 62, 95 % CI 4-964, p < 0.001) were factors significantly associated with adverse outcome. Thrombocytopenia, leukocytosis and Huang's radiological class 3 are associated with adverse outcome in patients with EPN.

  14. An uncommon cause of postpartum renal failure--bilateral emphysematous pyelonephritis.

    Science.gov (United States)

    Kumar, Naresh; Singh, Narinder Pal; Mittal, Amit; Valson, Anna T; Hira, Harmanjeet Singh

    2009-01-01

    Peripartum acute renal failure is an important complication related to pregnancy leading to significant morbidity and mortality. Emphysematous pyelonephritis (EPN) is a severe necrotizing infection of the renal parenchyma, with formation of gas within the collecting system, renal parenchyma, or perirenal tissues. EPN is common in persons with diabetes or urinary tract obstruction. Herein we report a case of bilateral emphysematous pyelonephritis in a postpartum lady who had no evidence of diabetes or urinary tract obstruction. Management of this condition has traditionally been aggressive, and surgery has been considered mandatory. Our patient was managed successfully with antibiotics and supportive measures alone.

  15. Imaging in emphysematous epididymo-orchitis: A rare cause of acute scrotum

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    Anitha Mandava

    2014-01-01

    Full Text Available Emphysematous epididymo-orchitis is an uncommon, acute inflammatory process of epididymis and testis characterized by the presence of air within the tissue. Patient presents with fever, acute pain, swelling and tenderness in the scrotum. Imaging is needed for rapid accurate diagnosis and to differentiate it from other causes of acute scrotum such as testicular torsion. We report a case of emphysematous epididymo-orchitis with imaging findings on plain radiography, ultrasound, CT and MRI and a brief review of the literature.

  16. Emphysematous pyelonephritis: A 10-year experience with 26 cases

    Science.gov (United States)

    Misgar, Raiz Ahmad; Mubarik, Idrees; Wani, Arshad Iqbal; Bashir, Mir Iftikhar; Ramzan, Mahroosa; Laway, Bashir Ahmad

    2016-01-01

    Background: Emphysematous pyelonephritis (EPN) is a necrotizing infection which results in gas within the renal parenchyma, collecting system, or perinephric tissue. A majority of cases occur in patients with diabetes mellitus (DM). In EPN, early aggressive medical treatment may avoid nephrectomy. Aims: The aim of this study was to analyze the characteristics of patients with EPN with respect to patient demographics, clinical presentation, diagnostic investigations, microbiological findings, treatment modality and outcome, and the influence of prognostic factors on the outcome. Materials and Methods: We reviewed the hospital records of 26 patients with EPN for clinical, laboratory, radiological, and microbiological findings, treatments given, and outcome. The severity of EPN was graded as per the Huang classification. We applied the reported prognostic factors to our patients to find out whether these factors correlated with failure of conservative treatment. Results: All the study subjects had DM and all but two of them were females. The majority of our patients (61.5%) had extensive EPN (class 3 or 4) and majority (76.9%) had two or more bad prognostic factors. Escherichia coli was the most common causative organism involved in 50% of our cases. Twenty-three (88.5%) of our patients responded to conservative treatment, two required nephrectomy, and one expired on conservative treatment. Conclusions: In this series of patients with EPN, all had DM, nearly all were women, and E. coli was the most frequently isolated pathogen. Nearly a third of our patients had bilateral disease. Despite the presence of two or more bad prognostic factors and extensive EPN (class 3 or 4) in a majority of our patients, conservative treatment afforded a striking success rate of 88.5%. We recommend early aggressive medical treatment and suggest that nephrectomy should be considered only if patients deteriorate or do not improve on conservative treatment. PMID:27366713

  17. Pathology of emphysematous pyelonephritis: A study of 11 cases

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    Archana Laxman Khade

    2016-01-01

    Full Text Available Objective: The objective was to study the pathological features of emphysematous pyelonephritis (EPN. Materials and Methods: A total of 11 nephrectomy specimens of EPN received in the surgical pathology section of a tertiary hospital in a metropolis city during the period 2005-2014 are included in this study. Clinical details were obtained from the patients′ records. All the patients had undergone total nephrectomy. All the specimens were fixed in 10% buffered formalin and processed for paraffin wax sectioning. The sections were stained with hematoxylin and eosin stain. Results: The most common symptoms were fever and costovertebral pain. Diabetes mellitus was present in 9 out of 11 cases and one case had calculus in the pelvis. One patient had underlying diabetes which was undiagnosed during the nephrectomy. Diagnosis of EPN was confirmed by the presence of gas and fluid in the renal tissue by computed tomography. The left kidney (nine cases, 81% was more frequently affected than the right kidney (two cases, 19%. EPN occurred in 40-60 years of age (mean age 51.5%, and out of 11 patients, 8 (81% were female. Escherichia coli was the commonly isolated organism from urine. Eight cases were of Type II EPN and three cases were Type I EPN. Histopathologic examination of all the cases of EPN showed acute suppurative (necrotizing inflammation of renal parenchyma and perirenal tissues associated with vasculitis of vessels and infarction. Conclusion: EPN is most commonly seen in patients with diabetes mellitus, and E. coli is the most common causative organism.

  18. Spin Dynamics Simulations of Multiple Echo Spacing Pulse Sequences in Grossly Inhomogeneous Fields

    Science.gov (United States)

    Heidler, R.; Bachman, H. N.; Johansen, Y.

    2008-12-01

    Pulse sequences with multiple lengths of echo spacings are used in oilfield NMR logging for diffusion-based NMR applications such as rock and fluid characterization. One specific implementation is the so-called diffusion editing sequence comprising two long echo spacings followed by a standard CPMG at a shorter echo spacing. The echoes in the CPMG portion contain signal from both the direct and stimulated echoes. Modern oilfield NMR logging tools are designed for continuous depth logging of earth formations by projecting both the static (B0) and dynamic (B1) fields into the formation. Both B0 and B1 profiles are grossly inhomogeneous which results in non-steady-state behavior in the early echoes. The spin dynamics effects present a challenge for processing the echo amplitudes to measure porosity (amplitude extrapolated to zero time) and attenuations for fluid or pore size characterization. In this work we describe a calculation of the spin dynamics of the diffusion editing sequence with two long echo spacings. The calculation takes into account full B1 and B0 field maps, and comparisons will be made for sensors and parameters typical of oilfield logging tools and environments.

  19. Radiological evidences from emphysematous cholecystitis. Manifestaciones radiologicas de la colecistitis enfisematosas

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    Martin Garcia, V.; Ganado Diaz, T.; Cabeza Martinez, B.; Montoro Martos, E.; Contreras Cecilia, E. (Hospital Clinico Universitario ' ' San Carlos' ' . Servicio de Radiodiagnostico. Madrid (Spain))

    1993-05-01

    Emphysematous cholecystitits is an uncommon clinical disorder, the diagnosis of which is based on the demonstration of the presence of gas in the vesicular wall and/or lumen. We present 9 cases studied by means of simple radiography, ultrasonography and abdominal CT scan. The diagnosis was based in every case on imaging methods and was confirmed surgically. (Author)

  20. miR-638 regulates gene expression networks associated with emphysematous lung destruction

    NARCIS (Netherlands)

    Christenson, Stephanie A.; Brandsma, Corry-Anke; Campbell, Joshua D.; Knight, Darryl A.; Pechkovsky, Dmitri V.; Hogg, James C.; Timens, Wim; Postma, Dirkje S.; Lenburg, Marc; Spira, Avrum

    2013-01-01

    Background: Chronic obstructive pulmonary disease (COPD) is a heterogeneous disease characterized by varying degrees of emphysematous lung destruction and small airway disease, each with distinct effects on clinical outcomes. There is little known about how microRNAs contribute specifically to the e

  1. Bilateral emphysematous pyelonephritis resolving to medical therapy: demonstration by US and CT

    Energy Technology Data Exchange (ETDEWEB)

    Grozel, F. [Centre Hospitalier Lyon Sud, Services de Radiologie A et B, F-69 310 Pierre Benite (France); Berthezene, Y. [Centre Hospitalier Lyon Sud, Services de Radiologie A et B, F-69 310 Pierre Benite (France); Guerin, C. [Centre Hospitalier Lyon Sud, Reanimation Medicale Sud, F-69 310 Pierre Benite (France); Tran-Minh, V.A. [Centre Hospitalier Lyon Sud, Services de Radiologie A et B, F-69 310 Pierre Benite (France); Croisille, M. [Centre Hospitalier Lyon Sud, Services de Radiologie A et B, F-69 310 Pierre Benite (France)

    1997-08-01

    Emphysematous pyelonephritis (EPN) is an uncommon and life-threatening necrotizing infection of the renal parenchyma occurring mostly in diabetic patients. It is usually unilateral. Nephrectomy is the current therapeutic procedure. We report the plain radiograph, US and CT findings in a 26-year-old diabetic woman who presented with bilateral EPN and was cured by medical treatment alone. (orig.). With 5 figs.

  2. Emphysematous pyelonephritis in a diabetic patient on maintenance hemodialysis: a case report.

    Science.gov (United States)

    Hamouda, M; Aloui, S; Skhiri, H; Letaif, A; Frih, M A; Ben Dhia, N; Elmay, M

    2014-05-01

    Emphysematous pyelonephritis (EP) is an uncommon acute infection characterized by the presence of gas in the renal parenchyma. It is extremely rare in hemodialysis (HD) patients and diabetics account for most cases. It is a rapidly progressive and life threatening infection with a high mortality rate. We report a case of emphysematous pyelonephritis in a HD patient who was treated successfully with radical nephrectomy and antibiotic therapy. A 46-year-old diabetic male with end stage renal disease (ESRD) secondary to diabetic nephropathy and on maintenance HD for the last five years presented with a two weeks history of fever and loin pain. He was treated with oral ciprofloxacin for one week with no improvement. His blood culture isolated Escherichia coli. Computed tomography scan of the abdominal disclosed an enlarged left kidney with massive gaseous collections. Accordingly, the diagnosis of emphysematous pyelonephritis was put forward, the patient underwent left nephrectomy together with intravenous imipenum and amikacin with good clinical response. The removed kidney showed features of acute pyelonephritis with micro-abscesses on histopathology. . Emphysematous pyelonephritis should always be considered in diabetics presenting with fever, loin pain, and features of sepsis not responding to antibiotic therapy; even though being on dialysis. Computed tomography scan of the abdomen remains an early diagnostic tool. Early treatment with potent antibiotics with or without surgical intervention can save patients' life.

  3. Seabird bycatch in pelagic longline fisheries is grossly underestimated when using only haul data.

    Directory of Open Access Journals (Sweden)

    Nigel Brothers

    Full Text Available Hundreds of thousands of seabirds are killed each year as bycatch in longline fisheries. Seabirds are predominantly caught during line setting but bycatch is generally recorded during line hauling, many hours after birds are caught. Bird loss during this interval may lead to inaccurate bycatch information. In this 15 year study, seabird bycatch was recorded during both line setting and line hauling from four fishing regions: Indian Ocean, Southern Ocean, Coral Sea and central Pacific Ocean. Over 43,000 albatrosses, petrels and skuas representing over 25 species were counted during line setting of which almost 6,000 seabirds attempted to take the bait. Bait-taking interactions were placed into one of four categories. (i The majority (57% of bait-taking attempts were "unsuccessful" involving seabirds that did not take the bait nor get caught or hooked. (ii One-third of attempts were "successful" with seabirds removing the bait while not getting caught. (iii One-hundred and seventy-six seabirds (3% of attempts were observed being "caught" during line setting, with three albatross species - Laysan (Phoebastria immutabilis, black-footed (P. nigripes and black-browed (Thalassarche melanophrys- dominating this category. However, of these, only 85 (48% seabird carcasses were retrieved during line hauling. Most caught seabirds were hooked through the bill. (iv The remainder of seabird-bait interactions (7% was not clearly observed, but likely involved more "caught" seabirds. Bait taking attempts and percentage outcome (e.g. successful, caught varied between seabird species and was not always related to species abundance around fishing vessels. Using only haul data to calculate seabird bycatch grossly underestimates actual bycatch levels, with the level of seabird bycatch from pelagic longline fishing possibly double what was previously thought.

  4. Seabird bycatch in pelagic longline fisheries is grossly underestimated when using only haul data.

    Science.gov (United States)

    Brothers, Nigel; Duckworth, Alan R; Safina, Carl; Gilman, Eric L

    2010-08-31

    Hundreds of thousands of seabirds are killed each year as bycatch in longline fisheries. Seabirds are predominantly caught during line setting but bycatch is generally recorded during line hauling, many hours after birds are caught. Bird loss during this interval may lead to inaccurate bycatch information. In this 15 year study, seabird bycatch was recorded during both line setting and line hauling from four fishing regions: Indian Ocean, Southern Ocean, Coral Sea and central Pacific Ocean. Over 43,000 albatrosses, petrels and skuas representing over 25 species were counted during line setting of which almost 6,000 seabirds attempted to take the bait. Bait-taking interactions were placed into one of four categories. (i) The majority (57%) of bait-taking attempts were "unsuccessful" involving seabirds that did not take the bait nor get caught or hooked. (ii) One-third of attempts were "successful" with seabirds removing the bait while not getting caught. (iii) One-hundred and seventy-six seabirds (3% of attempts) were observed being "caught" during line setting, with three albatross species - Laysan (Phoebastria immutabilis), black-footed (P. nigripes) and black-browed (Thalassarche melanophrys)- dominating this category. However, of these, only 85 (48%) seabird carcasses were retrieved during line hauling. Most caught seabirds were hooked through the bill. (iv) The remainder of seabird-bait interactions (7%) was not clearly observed, but likely involved more "caught" seabirds. Bait taking attempts and percentage outcome (e.g. successful, caught) varied between seabird species and was not always related to species abundance around fishing vessels. Using only haul data to calculate seabird bycatch grossly underestimates actual bycatch levels, with the level of seabird bycatch from pelagic longline fishing possibly double what was previously thought.

  5. Acute bilateral emphysematous pyelonephritis successfully managed by medical therapy alone: A case report and review of the literature

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    Calleja Juan

    2002-06-01

    Full Text Available Abstract Background Bilateral emphysematous pyelonephritis is a life threatening condition usually occurring in diabetics. Management of this condition has traditionally been aggressive and surgery is considered mandatory. However, this is itself a hazardous intervention in a septic, unstable patient with circulatory or liver failure. When bilateral disease is present, the need for long-term dialysis is obviously unavoidable. Case presentation We herein report one of the few cases of bilateral emphysematous pyelonephritis successfully managed by non-surgical treatment.

  6. Fatal Clostridium perfringens sepsis due to emphysematous gastritis and literature review.

    Science.gov (United States)

    Sarvari, Karoly Peter; Vasas, Bela; Kiss, Ildiko; Lazar, Andrea; Horvath, Istvan; Simon, Marianna; Peto, Zoltan; Urban, Edit

    2016-08-01

    A 76-year-old female patient was admitted to the Level I Emergency Department of University of Szeged with severe abdominal pain and vomiting. The clinical assessment with laboratory tests and radiological investigations confirmed severe sepsis associated with intravascular hemolysis and multiorgan failure and acute pancreatitis. On the abdominal CT, besides of other abnormalities, the presence of gas bubbles in the stomach, small intestines and liver were seen. The gastric alterations pointed to emphysematous gastritis. Despite of the medical treatment, the patient's condition quickly deteriorated and eight hours after admission the patient died. The autopsy evaluation revealed systemic infection of abdominal origin caused by gas-producing Gram-positive bacteria, and the post-mortem microbiological cultures confirmed the presence of Cloctridium perfringens in many abdominal organs. Emphysematous gastritis seemed to be the primary infectious focus. Copyright © 2016 Elsevier Ltd. All rights reserved.

  7. Wire-guided (Seldinger technique intubation through a face mask in urgent, difficult and grossly distorted airways

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    Jake M Heier

    2012-01-01

    Full Text Available We report two cases of successful urgent intubation using a Seldinger technique for airway management through an anesthesia facemask, while maintaining ventilation in patients with difficult airways and grossly distorted airway anatomy. In both cases, conventional airway management techniques were predicted to be difficult or impossible, and a high likelihood for a surgical airway was present. This technique was chosen as it allows tracheal tube placement through the nares during spontaneous ventilation with the airway stented open and oxygen delivery with either continuous positive airway pressure and/or pressure support ventilation. This unhurried technique may allow intubation when other techniques are unsuitable, while maintaining control of the airway.

  8. Wire-guided (Seldinger technique) intubation through a face mask in urgent, difficult and grossly distorted airways.

    Science.gov (United States)

    Heier, Jake M; Schroeder, Kristopher M; Galgon, Richard E; Arndt, George A

    2012-07-01

    We report two cases of successful urgent intubation using a Seldinger technique for airway management through an anesthesia facemask, while maintaining ventilation in patients with difficult airways and grossly distorted airway anatomy. In both cases, conventional airway management techniques were predicted to be difficult or impossible, and a high likelihood for a surgical airway was present. This technique was chosen as it allows tracheal tube placement through the nares during spontaneous ventilation with the airway stented open and oxygen delivery with either continuous positive airway pressure and/or pressure support ventilation. This unhurried technique may allow intubation when other techniques are unsuitable, while maintaining control of the airway.

  9. Emphysematous pyelonephritis treated with elective nephrectomy in a 75-year-old diabetic patient

    Directory of Open Access Journals (Sweden)

    Yayi He

    2012-01-01

    Full Text Available We present a case of 75-year-old man with type 2 diabetes and emphysematous pyelonephritis (EPN. The patient presented with abdominal pain, fever of undetermined origin and progressive decrease in urine output. Computerized tomography scan revealed gas formation in the left renal parenchyma and capsule. A left nephrectomy was performed. He made a quick recovery. EPN should be taken into consideration in diabetic patients with symptoms of pyelonephritis who show a poor response to conventional treatment. Elective nephrectomy may be life saving in some patients.

  10. Emphysematous pyelonephritis: A rare life-threatening complication after extracorporeal shock wave lithotripsy

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Su Ho; Chung, Dong Jin; Yeo, Dong Myung; Sonh, Dong Wan; Hahn, Sung Tae [Yeouido St. Mary' s Hospital, College of Medicine, The Catholic University of Korea, Seoul (Korea, Republic of)

    2015-09-15

    Emphysematous pyelonephritis (EPN), caused by extracorporeal shock wave lithotripsy (ESWL), has not been reported in the literature; and the mechanism of this disease is unknown. Although many studies have conjectured about the various causes of EPN, ESWL was not one of them. The patient in this report was a 65-year-old woman with a past medical history of diabetes; the patient underwent an ESWL that caused the EPN. To the best of our knowledge, this is the first report of an EPN case that was caused by ESWL.

  11. [Conservative treatment in diabetic patients with emphysematous pyelonephritis: about five cases].

    Science.gov (United States)

    El Majdoub, Aziz; Khallouk, Abdelhak; Farih, Moulay Hassan

    2016-01-01

    Acute emphysematous pyelonephritis (EPN) is a severe kidney infection. Early and effective treatment is essential to reduce high mortality rates due to this disease. Our study aims to highlight the clinical and paraclinical features as well as the peculiarities of therapeutic management of this disease and focus on the possibility of conservative treatment in diabetic patients. We analyzed the medical records of patients with EPN treated in the Department of Urology at the Hassan II University Hospital, Fez between January 2004 and January 2010. For each medical record we described clinical, paraclinical and therapeutic features as well as patient's evolution after treatment. We here report the case of 5 female patients whose average age was 45,6 years. All patients were diabetic. Lithiasic obstruction of the upper urinary tract was found in 3 patients (60%). The diagnosis was made by means of abdominal CT scan. All patients underwent resuscitation measures including antibiotic and insulin therapy. Conservative surgical procedure was performed in all cases. Indeed, surgical drainage of perirenal collections was performed in two cases, percutaneous renal drainage in one case and drainage using double-J ureteral catheter in 2 cases. Clinical and radiological evolution was excellent with renal preservation in all patients Emphysematous pyelonephritis is a rare and serious complication, especially in diabetic patients. Diagnosis is based on CT scan. Surgical treatment should be conservative in most cases, apart from severe forms, especially in diabetic patients who have potential risk of chronic renal failure.

  12. Investigation of four-dimensional computed tomography-based pulmonary ventilation imaging in patients with emphysematous lung regions.

    Science.gov (United States)

    Yamamoto, Tokihiro; Kabus, Sven; Klinder, Tobias; Lorenz, Cristian; von Berg, Jens; Blaffert, Thomas; Loo, Billy W; Keall, Paul J

    2011-04-07

    A pulmonary ventilation imaging technique based on four-dimensional (4D) computed tomography (CT) has advantages over existing techniques. However, physiologically accurate 4D-CT ventilation imaging has not been achieved in patients. The purpose of this study was to evaluate 4D-CT ventilation imaging by correlating ventilation with emphysema. Emphysematous lung regions are less ventilated and can be used as surrogates for low ventilation. We tested the hypothesis: 4D-CT ventilation in emphysematous lung regions is significantly lower than in non-emphysematous regions. Four-dimensional CT ventilation images were created for 12 patients with emphysematous lung regions as observed on CT, using a total of four combinations of two deformable image registration (DIR) algorithms: surface-based (DIR(sur)) and volumetric (DIR(vol)), and two metrics: Hounsfield unit (HU) change (V(HU)) and Jacobian determinant of deformation (V(Jac)), yielding four ventilation image sets per patient. Emphysematous lung regions were detected by density masking. We tested our hypothesis using the one-tailed t-test. Visually, different DIR algorithms and metrics yielded spatially variant 4D-CT ventilation images. The mean ventilation values in emphysematous lung regions were consistently lower than in non-emphysematous regions for all the combinations of DIR algorithms and metrics. V(HU) resulted in statistically significant differences for both DIR(sur) (0.14 ± 0.14 versus 0.29 ± 0.16, p = 0.01) and DIR(vol) (0.13 ± 0.13 versus 0.27 ± 0.15, p Jac) resulted in non-significant differences for both DIR(sur) (0.15 ± 0.07 versus 0.17 ± 0.08, p = 0.20) and DIR(vol) (0.17 ± 0.08 versus 0.19 ± 0.09, p = 0.30). This study demonstrated the strong correlation between the HU-based 4D-CT ventilation and emphysema, which indicates the potential for HU-based 4D-CT ventilation imaging to achieve high physiologic accuracy. A further study is needed to confirm these results.

  13. Emphysematous pyelonephritis in failed renal allograft: Case report and review of literature.

    Science.gov (United States)

    Bansal, Rahul Kumar; Lambe, Shahid; Kapoor, Anil

    2016-01-01

    Emphysematous pyelonephritis (EPN) in renal allograft is rare but potentially lethal complication and requires aggressive medical and/or surgical therapy to achieve cure. We report a case of 60-year-old diabetic male with poor cardiac function on maintenance hemodialysis, who underwent delayed allograft nephrectomy for EPN in failed renal allograft. Blood culture grew Bacteroides. He was stable in the postoperative period but passed away on day 4 due to myocardial infarction likely secondary to poor baseline cardiac function. Delay in diagnosis and treatment could have contributed to this unfavorable outcome. There is a paucity of published literature regarding EPN in the transplant population, such that management decisions (percutaneous conservative versus urgent surgical) are challenging. Further studies are required to establish treatment guidelines.

  14. Bilateral type emphysematous pyelonephritis: imaging evaluation; Pielonefritis enfisematosa bilateral tipo I. Evaluacion por la imagen

    Energy Technology Data Exchange (ETDEWEB)

    Salvador Cueto-Alvarez, L.; Piriz-Campos, E.; Ruiz-Garcia, T.; Roldan-Lora, F. [Hospital Universitario Virgen Macarena. Sevilla (Spain)

    2000-07-01

    Emphysematous pyelonephritis (EPN) is a serious infectious disease that occurs more frequently in diabetic patients. Radiological studies are indispensable for distinguishing between the two types since each is associated with a markedly different prognosis. We present a case of bilateral EPN diagnosed as type I on the basis of computed tomography findings, differentiating it from type II EPN, taking into account the prognostic value of this distinction. Type I EPN is characterized by the destruction of the renal parenchyma, a mottled or linear gas pattern and the absence of renal and perirenal fluid collection. Type II EPN is characterized by a loculated or bubbly gas pattern, the existence of fluid collection and less marked renal destruction. Type I is more aggressive and is associated with high rate of mortality. (Author) 7 refs.

  15. The first case report of emphysematous pyelonephritis and bacteremia due to Oligella urethralis.

    Science.gov (United States)

    Yamaguchi, Hirotaka; Yamaguchi, Yukihiro; Hadano, Yoshiro; Hayashi, Kenichi; Nagahara, Chie; Muratani, Tetsuro; Ohkusu, Kiyofumi

    2017-04-01

    Oligella urethralis (O. urethralis) is an organism that rarely causes infections in humans. We report the case of a 90-year-old bedridden woman with progressive dementia who was placed in a long-term-care facility. She was admitted to our hospital due to fever and unconsciousness with pyuria. The abdominal computed tomography showed left pneumatosis and urinary stone. Fluoroquinolones-resistant O. urethralis, which was identified by the Matrix-Assisted Laser Desorption Ionization-Time of Flight Mass Spectrometry (MALDI-TOF MS) and the 16S rRNA gene sequencing, was isolated form the blood and urine cultures at admission. To the best of our knowledge, this is the first case of emphysematous pyelonephritis caused by O. urethralis. Copyright © 2017 Elsevier GmbH. All rights reserved.

  16. Flow field analysis in expanding healthy and emphysematous alveolar models using particle image velocimetry.

    Science.gov (United States)

    Oakes, Jessica M; Day, Steven; Weinstein, Steven J; Robinson, Risa J

    2010-02-01

    Particulates that deposit in the acinus region of the lung have the potential to migrate through the alveolar wall and into the blood stream. However, the fluid mechanics governing particle transport to the alveolar wall are not well understood. Many physiological conditions are suspected to influence particle deposition including morphometry of the acinus, expansion and contraction of the alveolar walls, lung heterogeneities, and breathing patterns. Some studies suggest that the recirculation zones trap aerosol particles and enhance particle deposition by increasing their residence time in the region. However, particle trapping could also hinder aerosol particle deposition by moving the aerosol particle further from the wall. Studies that suggest such flow behavior have not been completed on realistic, nonsymmetric, three-dimensional, expanding alveolated geometry using realistic breathing curves. Furthermore, little attention has been paid to emphysemic geometries and how pathophysiological alterations effect deposition. In this study, fluid flow was examined in three-dimensional, expanding, healthy, and emphysemic alveolar sac model geometries using particle image velocimetry under realistic breathing conditions. Penetration depth of the tidal air was determined from the experimental fluid pathlines. Aerosol particle deposition was estimated by simple superposition of Brownian diffusion and sedimentation on the convected particle displacement for particles diameters of 100-750 nm. This study (1) confirmed that recirculation does not exist in the most distal alveolar regions of the lung under normal breathing conditions, (2) concluded that air entering the alveolar sac is convected closer to the alveolar wall in healthy compared with emphysematous lungs, and (3) demonstrated that particle deposition is smaller in emphysematous compared with healthy lungs.

  17. Visibles Revisited

    Science.gov (United States)

    Bridger, Mark; Zelevinsky, Andrei

    2005-01-01

    Within the set of points in the plane with integer coordinates, one point is said to be visible from another if no other point in the set lies between them. This study of visibility draws in topics from a wide variety of mathematical areas, including geometry, number theory, probability, and combinatorics.

  18. Altered surfactant protein A gene expression and protein homeostasis in rats with emphysematous changes

    Institute of Scientific and Technical Information of China (English)

    HU Qiong-jie; XIONG Sheng-dao; ZHANG Hui-lan; SHI Xue-mei; XU Yong-jian; ZHANG Zhen-xiang; ZHEN Guo-hua; ZHAO Jian-ping

    2008-01-01

    Background The decrease of suffactant protein(SP)secreted by the alveolar type Ⅱ cell is one of the important causes of limiting air of pulmonary emphysema.However,the SP-A gene and protein changes in this disease are rarely studied.This study was undertaken to investigate alterations in SP-A gene activity and protein,and to explore their roles in the pathogenesis of emphysematous changes.Methods Twenty Wistar rats were divided randomly into a normal control group(n=10)and a cigarette smoking(CS)+lipopolysaccharide(LPS)group(n=10).Ultra-structural changes were obsewed under an electron microscope.The number of cells positive for SP-A was measured by immunohistochemistry.The mRNA expression and protein Ievel of SP-A in the lung tissues were determined by quantitative polymerase chain reaction(qPCR)and Western blot separately.The protein level of SP-A in lavage fluid was determined by Western blot.Results The number of cells positive for SP-A of the CS+LPS group(0.35±0.03)was lower than that of the blank control group(0.72±0.06,P<0.05).The level of SP-A in the lung tissues of rats in the CS+LPS group(0.2765±0.0890)was lower than that in the blank controI group(0.6875±0.1578,P<0.05).The level of SP-A in the lavage fluid of rats in the CS+LPS group(0.8567±0.1458)was lower than that in the blank controI group(1.3541±0.2475,P<0.05).The lung tissues of rats in the CS+LPS group showed an approximate increase(0.4-fold)in SP-A mRNA levels relative to β-actin mRNA (P<0.05).Conclusions The changes of SP-A may be related to emphysematous changes in the lung.And cigarette smoke and LPS alter lung SP-A gene activity and protein homeostasis.

  19. Quantification and evaluation of the role of antielastin autoantibodies in the emphysematous lung.

    LENUS (Irish Health Repository)

    Low, Teck Boon

    2012-02-01

    Chronic obstructive pulmonary disease (COPD) may be an autoimmune disease. Smoking causes an imbalance of proteases and antiproteases in the lung resulting in the generation of elastin peptides that can potentially act as autoantigens. Similar to COPD, Z alpha-1 antitrypsin deficiency (Z-A1ATD) and cystic fibrosis (CF) are associated with impaired pulmonary antiprotease defences leading to unopposed protease activity. Here, we show that there is a trend towards higher bronchoalveolar lavage fluid (BALF) antielastin antibody levels in COPD and Z-A1ATD and significantly lower levels in CF compared to control BALF; the lower levels in CF are due to the degradation of these antibodies by neutrophil elastase. We also provide evidence that these autoantibodies have the potential to induce T cell proliferation in the emphysematous lung. This study highlights that antielastin antibodies are tissue specific, can be detected at elevated levels in COPD and Z-A1ATD BALF despite their being no differences in their levels in plasma compared to controls, and suggests a therapeutic role for agents targeting these autoantibodies in the lungs.

  20. Imaging features and guided drainage in emphysematous pyelonephritis: a study of 11 cases

    Energy Technology Data Exchange (ETDEWEB)

    Narlawar, R.S.; Raut, A.A. E-mail: abhijitaraut@hotmail.com; Nagar, A.; Hira, P.; Hanchate, V.; Asrani, A

    2004-02-01

    AIM: The purpose of the present study is to evaluate the role of image-guided drainage in emphysematous pyelonephritis (EPN). MATERIALS AND METHODS: We reviewed 11 patients with EPN treated either by ultrasonography (three patients) or computed tomography (CT)-guided drainage (eight patients). There were eight male and three female patients in our study with ages ranging from 24 to 75 years, mean 56.3 years. All the patients underwent plain radiography, ultrasonography and plain CT of the abdomen. Contrast-enhanced CT was performed in seven patients. RESULTS: Seven of 11 patients, were successfully treated with per cutaneous drainage. One patient died within 24 h (case 2), due to septicaemia. Three patients subsequently required nephrectomy. Replacement of the drainage catheter was required in one patient. The catheter was kept in situ, for an average of 17 days. The catheter drained pus and gas in all patients. The quantity of pus ranged from 300 to 2000 cm{sup 3}. All 10 patients improved symptomatically within 24 h of drainage, with improved urine output and serum creatinine levels within 48 h. CONCLUSION: CT-guided drainage of EPN has established itself as a safe, quick and life-saving palliative treatment of choice as opposed to conventional emergency nephrectomy. Excluding the patient who died, the success rate of our study was 70%.

  1. Treatment of a case of emphysematous pyelonephritis that presented with acute abdomen and pneumoperitoneum: a case report.

    Science.gov (United States)

    Park, Sang Hyun; Kim, Ki Hoon

    2015-08-01

    Emphysematous pyelonephritis is a severe, life-threatening infection of the renal parenchyma and perinephric tissues. This condition is primarily encountered in patients with diabetes mellitus or ureteral obstruction, and is characterized by the production of intrarenal and perinephric gas. Emphysematous pyelonephritis is associated with a high degree of morbidity and a high mortality rate. A 72-year-old woman with a history of diabetes mellitus, hypertension, and renal calculi was referred to our emergency department following 6 days of abdominal pain. She suddenly developed pain in the entire abdomen, and was transferred. Physical examination was a distended abdomen with hypoactive bowel sounds. The tenderness was diffuse, but was most prominent in the right upper abdominal quadrant; moreover, rebound tenderness was noted. Laboratory tests revealed a white blood cell count of 4,480/mm(3), platelet count of 17,000/mm(3), creatinine level of 1.64 mg/dl, and serum glucose level of 603 mg/dl. Abdominal computed tomography indicated the presence of free air in the intraperitoneal cavity and right perirenal space, hydronephrosis of the right kidney, and stones in the right distal ureter. After 1 hour, the vital signs changed and she appeared to become drowsy. Therefore, the patient was transferred to the operation room for laparotomy. On exploration of the abdomen, 1.5 L of pus-colored fluid was removed. Although the abdominal viscera and pelvic organs were examined, hollow viscus perforation site could not be observed. Moreover, tissue necrosis and a perforation site were identified at the superior border of the right kidney. Thus, emphysematous pyelonephritis was diagnosed and she underwent right radical nephrectomy. After the surgery, the patient was admitted to the intensive care unit for postoperative management. Follow-up CT performed after 10 days showed fluid collection and hematoma at the nephrectomy site. Hence, percutaneous drainage was performed. Another

  2. Emphysematous pyelonephritis in type II diabetes: A case report of an undiagnosed ureteric colic.

    Science.gov (United States)

    Vollans, Samuel R; Sehjal, Ranjit; Forster, James A; Rogawski, Karol M

    2008-09-30

    Emphysematous pyelonephritis (EPN) is a severe acute necrotising infection of the renal parenchyma and perirenal tissue, characterised by gas formation. 90% of cases are seen in association with diabetes mellitus. We report a case of undiagnosed ureteric obstruction in a type II diabetic, leading to EPN requiring emergency nephrectomy. A 59-year-old type II tablet controlled diabetic woman presented complaining of a five day history of right sided abdominal pain associated with vomiting, abdominal distension and absolute constipation. There were no lower urinary tract symptoms. Past surgical history included an open appendectomy and an abdominal hysterectomy. On examination, she was haemodynamically stable, the abdomen was soft, distended, and tender in the right upper and lower quadrants with no bowel sounds. Investigations revealed a CRP of 365 and 2+ blood and nitrite positive on the urine dipstick. The AXR was reported as normal on admission, however when reviewed in retrospect revealed the diagnosis. She was managed, therefore, as having adhesional bowel obstruction and a simple UTI. After four days, a CT was organised as she was not settling. This showed a right pyohydronephrosis with gas in the collecting system secondary to an 8 mm obstructing ureteric calculus. The kidney was drained percutaneously via a nephrostomy and the patient was commenced on a broad spectrum intravenous antibiotics. Despite this, she went on to need an emergency nephrectomy for uncontrolled severe sepsis. She was discharged in good health 15 days later. EPN carries a mortality of up to 40% with medical management alone. Early recognition of EPN in an obstructed kidney is essential to guide aggressive management, and in the presence of continued severe sepsis or organ dysfunction an urgent nephrectomy should be carried out. Diabetic patients who are known to have renal or ureteric calculi, whether symptomatic or not, should be considered for percutanous or ureteroscopic treatment. In

  3. Visibility Matters

    DEFF Research Database (Denmark)

    Wildgaard, Lorna Elizabeth

    2015-01-01

    Research production, which earns universities money, is accredited publications in peer-reviewed journals and books. Increasing research productivity is one policy amongst many used by management to boost growth and income. It is time for a pat on the back, the growth of knowledge and visibility...... at RSLIS ranks us among the top 10 contributors to core LIS journals in a new international ranking. The management should be pleased....

  4. Pielonefritis enfisematosa aguda bilateral: Un desafío terapéutico Acute bilateral emphysematous pyelonephritis: A therapeutic challenge

    Directory of Open Access Journals (Sweden)

    Marcelo J. Melero

    2007-06-01

    Full Text Available La pielonefritis enfisematosa es una forma poco común de infección renal, caracterizada por la presencia de bacterias coliformes productoras de gas que afecta preferentemente a los pacientes diabéticos. Comunicamos el caso de una mujer diabética de 57 años de edad que ingresó en el hospital por un shock séptico, signos de pielonefritis enfisematosa aguda bilateral y cetoacidosis diabética. En los cultivos de las muestras de orina y sangre desarrolló Escherichia coli. La paciente fue tratada exitosamente con antibióticos de amplio espectro por un tiempo prolongado, control diabético y medidas de sostén solamente. No fue necesario el drenaje con catéteres o la nefrectomía para superar esta situación potencialmente letal.Emphysematous pyelonephritis is a rare form of kidney infection characterized by the presence of gas-forming coliform bacteria which affects more frequently diabetic subjects. We report the case of a 57-years-old diabetic woman, who was admitted in septic shock, signs of acute bilateral emphysematous pyelonephritis, and diabetic ketoacidosis. Both blood and urine cultures yielded Escherichia coli. The patient was successfully treated using long-term broad-spectrum antibiotics, diabetic control and supportive measures alone. Catheter drainage and nephrectomy were not necessary to overcome this life threatening situation.

  5. Transmission of an extended-spectrum-beta-lactamase-producing Escherichia coli (sequence type ST131) strain between a father and daughter resulting in septic shock and Emphysematous pyelonephritis.

    Science.gov (United States)

    Ender, Peter T; Gajanana, Deepakraj; Johnston, Brian; Clabots, Connie; Tamarkin, Frank J; Johnson, James R

    2009-11-01

    Probable transmission of an extended-spectrum-beta-lactamase-producing Escherichia coli strain (sequence type ST131) between a father and daughter was documented. The father developed severe, recurrent pyelonephritis with multiple small abscesses; the daughter later developed septic shock, bacteremia, and extensive emphysematous pyelonephritis. This multidrug-resistant E. coli clone appears to be highly pathogenic and transmissible.

  6. Tratamento operatório das bolhas pulmonares gigantes Surgical treatment of giant emphysematous lung bullae

    Directory of Open Access Journals (Sweden)

    Marcio Botter

    2007-06-01

    in Brazil led us to perform the current work to describe the historical evolution and to analyze results of the surgical treatment of Giant Emphysematous Lung Bullae at the Santa Casa de São Paulo. METHODS: We have retrospectively assessed, between January 1979 and June 2005, the medical records of 83 patients submitted to one of four surgical modalities: the thoracoscopic bullectomy, VATS bullectomy, VATS bullae drainage and bullae drainage with local anesthesia, totaling 92 surgeries. Parameters analyzed were hospitalization time, post-surgical complications, perioperative and late mortality in addition to clinical and functional pre- and post- surgical parameters. RESULTS: Morbidity was 40.2% and early post-surgical mortality 4.3%. Post-surgical complications were associated to the patient's morbid history. Factors such as diffuse pulmonary emphysema, multiple bullae and age did not influence early complications. There was an improvement in the symptomatology and functional results in 94.5% of the patients. There was no return on he operated bullae. Mortality five years after surgery was of 18.3% and arose, primarily from clinical progression of the diffuse pulmonary emphysema. CONCLUSIONS: Several surgical modalities were performed to treat the emphysematous lung bullae, from bullectomy to thoracotomy, at the initial phase until drainage of the bullae with local anesthesia and sprayed talc, the currently preferred modality. Regardless of the method used, however, notwithstanding the relatively high morbidity, post-surgical results are highly favorable with low mortality and uncontestable clinical-functional improvement of the operated patients.

  7. Patient with perforation caused by emphysematous cholecystitis who showed flare on the skin of the right dorsal lumbar region and intraperitoneal free gas.

    Science.gov (United States)

    Kanehiro, Tetsuya; Tsumura, Hiroaki; Ichikawa, Toru; Hino, Yuji; Murakami, Yoshiaki; Sueda, Taijiro

    2008-01-01

    We report an 84-year-old man with perforation caused by emphysematous cholecystitis who showed flare on the skin of the right dorsal lumbar region and intraperitoneal free gas. The patient was admitted for abdominal pain, abdominal swelling, and consciousness disorder 18 days after the onset. Abdominal computed tomography (CT) revealed emphysema in the gallbladder and a small amount of intraperitoneal free gas. Intraoperative findings suggested gangrenous cholecystitis. The gallbladder wall was perforated, and an abscess involving the right subphrenic region, the periphery of the liver and gallbladder, and the right paracolonic groove, was detected. The flare on the body surface may have reflected abscess formation in the right abdominal cavity. Emphysematous cholecystitis induces necrosis and perforation in many patients, and immediate strategies such as emergency surgery are important.

  8. National survey data for zoonotic schistosomiasis in the Philippines grossly underestimates the true burden of disease within endemic zones: implications for future control.

    Science.gov (United States)

    Olveda, Remigio M; Tallo, Veronica; Olveda, David U; Inobaya, Marianette T; Chau, Thao N; Ross, Allen G

    2016-04-01

    Zoonotic schistosomiasis has a long endemic history in the Philippines. Human mass drug administration has been the cornerstone of schistosomiasis control in the country for the past three decades. Recent publications utilizing retrospective national survey data have indicated that the national human prevalence of the disease is disease is now close to elimination. However, the evidence for such a claim is weak, given that less than a third of the human population is currently being treated annually within endemic zones and only a third of those treated actually swallow the tablets. For those who consume the drug at the single oral dose of 40mg/kg, the estimated cure rate is 52% based on a recent meta-analysis. Thus, approximately 5% of the endemic human population is in reality receiving the appropriate treatment. To compound this public health problem, most of the bovines in the endemic communities are concurrently infected but are not treated under the current national control programme. Given this evidence, it is believed that the human prevalence of schistosomiasis within endemic regions has been grossly underestimated. Inherent flaws in the reporting of national schistosomiasis prevalence data are reported here, and the problems of utilizing national retrospective data in making geographic information system (GIS) risk maps and advising policy makers of the outcomes are highlighted.

  9. National survey data for zoonotic schistosomiasis in the Philippines grossly underestimates the true burden of disease within endemic zones: implications for future control

    Directory of Open Access Journals (Sweden)

    Remigio M. Olveda

    2016-04-01

    Full Text Available Zoonotic schistosomiasis has a long endemic history in the Philippines. Human mass drug administration has been the cornerstone of schistosomiasis control in the country for the past three decades. Recent publications utilizing retrospective national survey data have indicated that the national human prevalence of the disease is <1%, hence the disease is now close to elimination. However, the evidence for such a claim is weak, given that less than a third of the human population is currently being treated annually within endemic zones and only a third of those treated actually swallow the tablets. For those who consume the drug at the single oral dose of 40 mg/kg, the estimated cure rate is 52% based on a recent meta-analysis. Thus, approximately 5% of the endemic human population is in reality receiving the appropriate treatment. To compound this public health problem, most of the bovines in the endemic communities are concurrently infected but are not treated under the current national control programme. Given this evidence, it is believed that the human prevalence of schistosomiasis within endemic regions has been grossly underestimated. Inherent flaws in the reporting of national schistosomiasis prevalence data are reported here, and the problems of utilizing national retrospective data in making geographic information system (GIS risk maps and advising policy makers of the outcomes are highlighted.

  10. The inspiratory capacity/total lung capacity ratio as a predictor of survival in an emphysematous phenotype of chronic obstructive pulmonary disease

    Directory of Open Access Journals (Sweden)

    French A

    2015-07-01

    Full Text Available Aimee French, David Balfe, James M Mirocha, Jeremy A Falk, Zab Mosenifar Cedars-Sinai Medical Center, Division of Pulmonary and Critical Care Medicine, Los Angeles, CA, USA Background: Forced expiratory volume in 1 second (FEV1 grades severity of COPD and predicts survival. We hypothesize that the inspiratory capacity/total lung capacity (IC/TLC ratio, a sensitive measure of static lung hyperinflation, may have a significant association with survival in an emphysematous phenotype of COPD.Objectives: To access the association between IC/TLC and survival in an emphysematous phenotype of COPD. Methods: We performed a retrospective analysis of a large pulmonary function (PF database with 39,050 entries, from April 1978 to October 2009. Emphysematous COPD was defined as reduced FEV1/forced vital capacity (FVC, increased TLC, and reduced diffusing capacity of the lungs for carbon monoxide (DLCO; beyond 95% confidence intervals [CIs]. We evaluated the association between survival in emphysematous COPD patients and the IC/TLC ratio evaluated both as dichotomous (≤25% vs >25% and continuous predictors. Five hundred and ninety-six patients had reported death dates.Results: Univariate analysis revealed that IC/TLC ≤25% was a significant predictor of death (hazard ratio [HR]: 2.39, P<0.0001. Median survivals were respectively 4.3 (95% CI: 3.8–4.9 and 11.9 years (95% CI: 10.3–13.2. Multivariable analysis revealed age (HR: 1.19, 95% CI: 1.14–1.24, female sex (HR: 0.69, 95% CI: 0.60–0.83, and IC/TLC ≤25% (HR: 1.69, 95% CI: 1.34–2.13 were related to the risk of death. Univariate analysis showed that continuous IC/TLC was associated with death, with an HR of 1.66 (95% CI: 1.52–1.81 for a 10% decrease in IC/TLC.Conclusion: Adjusting for age and sex, IC/TLC ≤25% is related to increased risk of death, and IC/TLC as a continuum, is a significant predictor of mortality in emphysematous COPD patients.  Keywords: emphysema, pulmonary function

  11. Endobronchial valves in severe emphysematous patients: CT evaluation of lung fissures completeness, treatment radiological response and quantitative emphysema analysis

    Directory of Open Access Journals (Sweden)

    Marcel Koenigkam-Santos

    2013-02-01

    Full Text Available OBJECTIVE: To evaluate lung fissures completeness, post-treatment radiological response and quantitative CT analysis (QCTA in a population of severe emphysematous patients submitted to endobronchial valves (EBV implantation. MATERIALS AND METHODS: Multi-detectors CT exams of 29 patients were studied, using thin-section low dose protocol without contrast. Two radiologists retrospectively reviewed all images in consensus; fissures completeness was estimated in 5% increments and post-EBV radiological response (target lobe atelectasis/volume loss was evaluated. QCTA was performed in pre and post-treatment scans using a fully automated software. RESULTS: CT response was present in 16/29 patients. In the negative CT response group, all 13 patients presented incomplete fissures, and mean oblique fissures completeness was 72.8%, against 88.3% in the other group. QCTA most significant results showed a reduced post-treatment total lung volume (LV (mean 542 ml, reduced EBV-submitted LV (700 ml and reduced emphysema volume (331.4 ml in the positive response group, which also showed improved functional tests. CONCLUSION: EBV benefit is most likely in patients who have complete interlobar fissures and develop lobar atelectasis. In patients with no radiological response we observed a higher prevalence of incomplete fissures and a greater degree of incompleteness. The fully automated QCTA detected the post-treatment alterations, especially in the treated lung analysis.

  12. Endobronchial valves in severe emphysematous patients: CT evaluation of lung fissures completeness, treatment radiological response and quantitative emphysema analysis

    Energy Technology Data Exchange (ETDEWEB)

    Koenigkam-Santos, Marcel, E-mail: marcelk46@yahoo.com.br, E-mail: marcelk46@usp.b [Universidade de Sao Paulo (HCFMRP/USP), Ribeirao Preto, SP (Brazil). Hospital das Clinicas da Faculdade de Medicina; Paula, Wagner Diniz de [University of Brasilia (UnB), DF (Brazil). Brasilia University Hospital; Gompelmann, Daniela [University of Heidelberg (Germany). Department of Pneumology and Respiratory Medicine of the Chest Clinic (Thoraxklinik); Kauczor, Hans-Ulrich [University of Heidelberg (Germany). Department of Diagnostic and Interventional Radiology; Heussel, Claus Peter; Puderbach, Michael [University of Heidelberg (Germany). Department of Diagnostic and Interventional Radiology with Nuclear Medicine of the Chest Clinic (Thoraxklinik)

    2013-01-15

    Objective: To evaluate lung fissures completeness, post-treatment radiological response and quantitative CT analysis (QCTA) in a population of severe emphysematous patients submitted to endobronchial valves (EBV) implantation. Materials and Methods: Multi-detectors CT exams of 29 patients were studied, using thin-section low dose protocol without contrast. Two radiologists retrospectively reviewed all images in consensus; fissures completeness was estimated in 5% increments and post-EBV radiological response (target lobe atelectasis/volume loss) was evaluated. QCTA was performed in pre and post-treatment scans using a fully automated software. Results: CT response was present in 16/29 patients. In the negative CT response group, all 13 patients presented incomplete fissures, and mean oblique fissures completeness was 72.8%, against 88.3% in the other group. QCTA most significant results showed a reduced post-treatment total lung volume (LV) (mean 542 ml), reduced EBV-submitted LV (700 ml) and reduced emphysema volume (331.4 ml) in the positive response group, which also showed improved functional tests. Conclusion: EBV benefit is most likely in patients who have complete interlobar fissures and develop lobar atelectasis. In patients with no radiological response we observed a higher prevalence of incomplete fissures and a greater degree of incompleteness. The fully automated QCTA detected the post-treatment alterations, especially in the treated lung analysis. (author)

  13. Laparoscopy in the management of emphysematous cholecystitis and secondary appendicitis in an 11-year-old child with insulin-dependent diabetes mellitus

    Directory of Open Access Journals (Sweden)

    Kamalesh Pal

    2011-01-01

    Full Text Available Acute abdomen in a diabetic child may cause diagnostic dilemma. Acalculous emphysematous cholecystitis (EC, although reported among critically ill or diabetic adults, is an uncommon occurrence in the children. It may complicate the presentation due to its varied manifestations; especially when associated with other concomitant intra-abdominal inflammatory pathologies. We encountered a rare concurrence of acute EC complicated with pericholecystic fluid collection and secondary appendicitis causing non-specific acute abdomen in an 11-year-old obese boy with insulin-dependent diabetes mellitus. Laparoscopy proved to be a highly useful tool in the diagnosis and treatment of this surgical dilemma.

  14. Synchronous infection of the aorta and the testis: emphysematous epididymo-orchitis, abdominal aortic mycotic aneurysm, and testicular artery pseudoaneurysm diagnosed by use of MDCT.

    Science.gov (United States)

    Hegde, Rahul G; Balani, Ankit; Merchant, Suleman A; Joshi, Anagha R

    2014-07-01

    We report clinical details and imaging findings for a case of emphysematous epididymo-orchitis with co-existing mycotic abdominal aortic aneurysm and a testicular artery pseudoaneurysm in a diabetic 65-year-old male. We report imaging findings from ultrasonography (USG) and contrast-enhanced multidetector computed tomography (MDCT). Use of MDCT to identify, confirm, and define the extent of the disease, and its utility in understanding the pathogenesis of this rare condition are highlighted. For such lethal infections, early diagnosis and intervention can be lifesaving; imaging can be of crucial importance in this.

  15. Visibly Pushdown Automata

    DEFF Research Database (Denmark)

    Srba, Jiri

    2006-01-01

    We investigate the possibility of (bi)simulation-like preorder/equivalence checking on the class of visibly pushdown automata and its natural subclasses visibly BPA (Basic Process Algebra) and visibly one-counter automata. We describe generic methods for proving complexity upper and lower bounds...

  16. Visibly Pushdown Automata

    DEFF Research Database (Denmark)

    Srba, Jiri

    2006-01-01

    We investigate the possibility of (bi)simulation-like preorder/equivalence checking on the class of visibly pushdown automata and its natural subclasses visibly BPA (Basic Process Algebra) and visibly one-counter automata. We describe generic methods for proving complexity upper and lower bounds...

  17. Visibility and Citation Impact

    OpenAIRE

    Ale Ebrahim, Nader; Salehi, Hadi; Embi, Mohamed Amin; Habibi Tanha, Farid

    2014-01-01

    The number of publications is the first criteria for assessing a researcher output. However, the main measurement for author productivity is the number of citations, and citations are typically related to the paper's visibility. In this paper, the relationship between article visibility and the number of citations is investigated. A case study of two researchers who are using publication marketing tools confirmed that the article visibility will greatly improve the citation impact. Some st...

  18. Visibility and Citation Impact

    OpenAIRE

    Ale Ebrahim, Nader

    2014-01-01

    The number of publications is the first criteria for assessing a researcher output. However, the main measurement for author productivity is the number of citations, and citations are typically related to the paper's visibility. In this paper, the relationship between article visibility and the number of citations is investigated. A case study of two researchers who are using publication marketing tools confirmed that the article visibility will greatly improve the citation impact. Some s...

  19. Visibility and Citation Impact

    OpenAIRE

    Mohamed Amin Embi; Seyed Mohammad Motahar; Nader Ale Ebrahim نادر آل ابراهیم; Hossein gholizadeh; hossein gholizadeh

    2017-01-01

    The number of publications is the first criteria for assessing a researcher output. However, the main measurement for author productivity is the number of citations, and citations are typically related to the paper's visibility. In this paper, the relationship between article visibility and the number of citations is investigated. A case study of two researchers who are using publication marketing tools confirmed that the article visibility will greatly improve the citation impact. Some strat...

  20. Viewer Makes Radioactivity "Visible"

    Science.gov (United States)

    Yin, L. I.

    1983-01-01

    Battery operated viewer demonstrates feasibility of generating threedimensional visible light simulations of objects that emit X-ray or gamma rays. Ray paths are traced for two pinhold positions to show location of reconstructed image. Images formed by pinholes are converted to intensified visible-light images. Applications range from radioactivity contamination surveys to monitoring radioisotope absorption in tumors.

  1. Between visibility and surveillance

    DEFF Research Database (Denmark)

    Uldam, Julie

    visible. It thus enables activists to monitor and expose corporate misconduct, but simultaneously renders them vulnerable to surveillance from corporations. In this presentation, I examine these practices and discuss their implications for political participation by drawing on examples of companies...

  2. Visible epiglottis in children.

    Science.gov (United States)

    Jamaluddin Ahmed, Farooque; Shinohara, Andrá Luis; Bonifécio da Silva, Salete Moura; Andreo, Jesus Carlos; Rodrigues, Antonio de Castro

    2014-01-01

    Visible epiglottis is a rare anatomical variant which is usually asymptomatic without the need of any medical or surgical intervention. It is most commonly seen in children but there are some reports of its prevalence in adults too. Cases of visible epiglottis seem to be unfamiliar among dental professionals. In this report, we have attempted to present this anatomical variant of epiglottis in the feld of dentistry by describing a case of an 8-year-old girl who presented to the department of pediatric dentistry for normal dental check-up unaware of the existence of the visible epiglottis. How to cite this article: Ahmed FJ, Shinohara AL, da Silva SMB, Andreo JC, de Castro Rodrigues A. Visible Epiglottis in Children. Int J Clin Pediatr Dent 2014;7(3):223-224.

  3. Cistitis enfisematosa Emphysematous Cistitis

    OpenAIRE

    Claudio Orlich-Castelán; Eduardo Loyola-Castro

    2010-01-01

    Se reporta el caso de un marinero con diabetes mellitus descompensada e insuficiencia renal con una cistitis enfisematosa, evidente en un ultrasonido de la vejiga que se presentó con hematuria, disuria, dolor suprapúbico y síntomas urinarios obstructivos, tratada inicialmente en altamar por 48 horas, con antibióticos. Se mantuvo en excelente estado general y afebril, sin poder aislar una bacteria causal, por haberse iniciado antibioticoterapia temprana; fue tratado además con cirugía conserva...

  4. Predicting Visibility of Aircraft

    Science.gov (United States)

    Watson, Andrew; Ramirez, Cesar V.; Salud, Ellen

    2009-01-01

    Visual detection of aircraft by human observers is an important element of aviation safety. To assess and ensure safety, it would be useful to be able to be able to predict the visibility, to a human observer, of an aircraft of specified size, shape, distance, and coloration. Examples include assuring safe separation among aircraft and between aircraft and unmanned vehicles, design of airport control towers, and efforts to enhance or suppress the visibility of military and rescue vehicles. We have recently developed a simple metric of pattern visibility, the Spatial Standard Observer (SSO). In this report we examine whether the SSO can predict visibility of simulated aircraft images. We constructed a set of aircraft images from three-dimensional computer graphic models, and measured the luminance contrast threshold for each image from three human observers. The data were well predicted by the SSO. Finally, we show how to use the SSO to predict visibility range for aircraft of arbitrary size, shape, distance, and coloration. PMID:19462007

  5. Measuring visibility using smartphones

    Science.gov (United States)

    Friesen, Jan; Bialon, Raphael; Claßen, Christoph; Graffi, Kalman

    2017-04-01

    Spatial information on fog density is an important parameter for ecohydrological studies in cloud forests. The Dhofar cloud forest in Southern Oman exhibits a close interaction between the fog, trees, and rainfall. During the three month monsoon season the trees capture substantial amounts of horizontal precipitation from fog which increases net precipitation below the tree canopy. As fog density measurements are scarce, a smartphone app was designed to measure visibility. Different smartphone units use a variety of different parts. It is therefore important to assess the developed visibility measurement across a suite of different smartphones. In this study we tested five smartphones/ tablets (Google/ LG Nexus 5X, Huawei P8 lite, Huawei Y3, HTC Nexus 9, and Samsung Galaxy S4 mini) against digital camera (Sony DLSR-A900) and visual visibility observations. Visibility was assessed from photos using image entropy, from the number of visible targets, and from WiFi signal strength using RSSI. Results show clear relationships between object distance and fog density, yet a considerable spread across the different smartphone/ tablet units is evident.

  6. UVISS preliminary visibility analysis

    DEFF Research Database (Denmark)

    Betto, Maurizio

    1998-01-01

    The goal of this work is to obtain a preliminary assessment of the sky visibility for anastronomical telescope located on the express pallet of the International SpaceStation (ISS)} taking into account the major constraints imposed on the instrument by the ISSattitude and structure. Part of the w......The goal of this work is to obtain a preliminary assessment of the sky visibility for anastronomical telescope located on the express pallet of the International SpaceStation (ISS)} taking into account the major constraints imposed on the instrument by the ISSattitude and structure. Part...

  7. Visible Epiglottis in Children

    OpenAIRE

    2015-01-01

    ABSTRACT% Visible epiglottis is a rare anatomical variant which is usually asymptomatic without the need of any medical or surgical intervention. It is most commonly seen in children but there are some reports of its prevalence in adults too. Cases of visible epiglottis seem to be unfamiliar among dental professionals. In this report, we have attempted to present this anatomical variant of epiglottis in the feld of dentistry by describing a case of an 8-year-old girl who presented to the depa...

  8. Visible Solid State Lasers

    NARCIS (Netherlands)

    Hikmet, R.A.M.

    2007-01-01

    Diode lasers can be found in various applications most notably in optical communication and optical storage. Visible lasers were until recently were all based on IR diode lasers. Using GaN, directly blue and violet emitting lasers have also been introduced to the market mainly in the area of optical

  9. Making Invisible Forces Visible

    DEFF Research Database (Denmark)

    Ratner, Helene; Pors, Justine Grønbæk

    2013-01-01

    This paper investigates managerial tactics of visualisation when a need to know and manage employees' values and attitudes is expressed. Using the Danish public school as a case study, we explore how school managers use teachers' emotions to render visible presumably invisible information about...

  10. Visible Human Project

    Science.gov (United States)

    ... Library of Medicine thanks the men and the women who will their body to science, thereby enabling medical research and development. Further Information General Information A description of The Visible Human Project ® image data and how to obtain it (includes license ...

  11. Making Invisible Forces Visible

    DEFF Research Database (Denmark)

    Ratner, Helene Gad

    2013-01-01

    their 'true' attitudes and values. The paper draws on theories of affect as well as actor-network theory to analyse three incidents where managers turn their interpretations of teachers' emotions into such information. These incidents suggest that the efforts to render employees' attitudes and values visible...

  12. Visible Solid State Lasers

    NARCIS (Netherlands)

    Hikmet, R.A.M.

    2007-01-01

    Diode lasers can be found in various applications most notably in optical communication and optical storage. Visible lasers were until recently were all based on IR diode lasers. Using GaN, directly blue and violet emitting lasers have also been introduced to the market mainly in the area of optical

  13. The visibility complex

    NARCIS (Netherlands)

    Pocchiola, M; Vegter, G

    1996-01-01

    We introduce the visibility complex (rr 2-dimensional regular cell complex) of a collection of n pairwise disjoint convex obstacles in the plane. It can be considered as a subdivision of the set of free rays (i.e., rays whose origins lie in free space, the complement of the obstacles). Its cells cor

  14. UVISS preliminary visibility analysis

    DEFF Research Database (Denmark)

    Betto, Maurizio

    1998-01-01

    The goal of this work is to obtain a preliminary assessment of the sky visibility for anastronomical telescope located on the express pallet of the International SpaceStation (ISS)} taking into account the major constraints imposed on the instrument by the ISSattitude and structure. Part...

  15. Antioxidant activity of pomegranate juice reduces emphysematous changes and injury secondary to cigarette smoke in an animal model and human alveolar cells

    Directory of Open Access Journals (Sweden)

    Husari A

    2016-02-01

    demonstrated emphysematous changes when compared to Control. PJ supplementation to CS animals attenuated the increased expression of TNF-α and normalized lung cytoarchitecture. At the cellular level, CS extract reduced cellular proliferation and triggered cellular death. Pretreatment with PJ attenuated the damaging effects of CS extract on cultured human alveolar cells. Conclusion: The expression of inflammatory mediators associated with CS exposure and the emphysematous changes noted with chronic CS exposure were reduced with PJ supplementation. In vitro, PJ attenuated the damaging effects of CS extract on cultured human alveolar cells. Keywords: reactive oxygen species, antioxidants, acute lung injury, emphysema, pomegranate extract, cigarette smoke, inflammatory mediators

  16. Making Invisible Forces Visible

    DEFF Research Database (Denmark)

    Ratner, Helene; Pors, Justine Grønbæk

    2013-01-01

    This paper investigates managerial tactics of visualisation when a need to know and manage employees' values and attitudes is expressed. Using the Danish public school as a case study, we explore how school managers use teachers' emotions to render visible presumably invisible information about...... their 'true' attitudes and values. The paper draws on theories of affect as well as actor-network theory to analyse three incidents where managers turn their interpretations of teachers' emotions into such information. These incidents suggest that the efforts to render employees' attitudes and values visible...... install a normative emotional scale where an ideal employee displays emotional investment and self-control. This has implications, not only for employees who are expected to exhibit the 'right' emotions, but also for management, which comes to depend on transient emotions and co-presence in situations...

  17. Visibility graph motifs

    CERN Document Server

    Iacovacci, Jacopo

    2015-01-01

    Visibility algorithms transform time series into graphs and encode dynamical information in their topology, paving the way for graph-theoretical time series analysis as well as building a bridge between nonlinear dynamics and network science. In this work we introduce and study the concept of visibility graph motifs, smaller substructures that appear with characteristic frequencies. We develop a theory to compute in an exact way the motif profiles associated to general classes of deterministic and stochastic dynamics. We find that this simple property is indeed a highly informative and computationally efficient feature capable to distinguish among different dynamics and robust against noise contamination. We finally confirm that it can be used in practice to perform unsupervised learning, by extracting motif profiles from experimental heart-rate series and being able, accordingly, to disentangle meditative from other relaxation states. Applications of this general theory include the automatic classification a...

  18. Social media visibility

    DEFF Research Database (Denmark)

    Uldam, Julie

    2017-01-01

    of activists remains under-researched. This article examines BP’s surveillance of activists who criticise the company’s corporate social responsibility (CSR) programme as ‘greenwashing’. In this way, it goes beyond corporations’ uses of big data and instead explores how they monitor and discuss strategies......As activists move from alternative media platforms to commercial social media platforms, they face increasing challenges in protecting their online security and privacy. While government surveillance of activists is well-documented in scholarly research and the media, corporate surveillance...... for responding to the activities of individual activists in social media. It shows that while social media afford an unprecedented level of visibility for activists, it comes with the risk of being monitored by corporations. Theoretically, it draws on conceptions of visibility in social sciences and media...

  19. Incremental Visualizer for Visible Objects

    DEFF Research Database (Denmark)

    Bukauskas, Linas; Bøhlen, Michael Hanspeter

    This paper discusses the integration of database back-end and visualizer front-end into a one tightly coupled system. The main aim which we achieve is to reduce the data pipeline from database to visualization by using incremental data extraction of visible objects in a fly-through scenarios. We...... also argue that passing only relevant data from the database will substantially reduce the overall load of the visualization system. We propose the system Incremental Visualizer for Visible Objects (IVVO) which considers visible objects and enables incremental visualization along the observer movement...... visibility ranges and show that considering visibility ranges is crucial when considering incremental visible object extraction....

  20. Interferometric visibility and coherence

    Science.gov (United States)

    Biswas, Tanmoy; García Díaz, María; Winter, Andreas

    2017-07-01

    Recently, the basic concept of quantum coherence (or superposition) has gained a lot of renewed attention, after Baumgratz et al. (Phys. Rev. Lett. 113, 140401. (doi:10.1103/PhysRevLett.113.140401)), following Åberg (http://arxiv.org/abs/quant-ph/0612146), have proposed a resource theoretic approach to quantify it. This has resulted in a large number of papers and preprints exploring various coherence monotones, and debating possible forms for the resource theory. Here, we take the view that the operational foundation of coherence in a state, be it quantum or otherwise wave mechanical, lies in the observation of interference effects. Our approach here is to consider an idealized multi-path interferometer, with a suitable detector, in such a way that the visibility of the interference pattern provides a quantitative expression of the amount of coherence in a given probe state. We present a general framework of deriving coherence measures from visibility, and demonstrate it by analysing several concrete visibility parameters, recovering some known coherence measures and obtaining some new ones.

  1. Visible Genotype Sensor Array

    Directory of Open Access Journals (Sweden)

    Takashi Imai

    2008-04-01

    Full Text Available A visible sensor array system for simultaneous multiple SNP genotyping has been developed using a new plastic base with specific surface chemistry. Discrimination of SNP alleles is carried out by an allele-specific extension reaction using immobilized oligonucleotide primers. The 3’-ends of oligonucleotide primers are modified with a locked nucleic acid to enhance their efficiency in allelic discrimination. Biotin-dUTPs included in the reaction mixture are selectively incorporated into extending primer sequences and are utilized as tags for alkaline phosphatase-mediated precipitation of colored chemical substrates onto the surface of the plastic base. The visible precipitates allow immediate inspection of typing results by the naked eye and easy recording by a digital camera equipped on a commercial mobile phone. Up to four individuals can be analyzed on a single sensor array and multiple sensor arrays can be handled in a single operation. All of the reactions can be performed within one hour using conventional laboratory instruments. This visible genotype sensor array is suitable for “focused genomics” that follows “comprehensive genomics”.

  2. Visible parts of fractal percolation

    CERN Document Server

    Arhosalo, I; Järvenpää, M; Rams, M; Shmerkin, P

    2009-01-01

    We study dimensional properties of visible parts of fractal percolation in the plane. Provided that the dimension of the fractal percolation is at least 1, we show that, conditioned on non-extinction, almost surely all visible parts from lines are 1-dimensional. Furthermore, almost all of them have positive and finite Hausdorff measure. We also verify analogous results for visible parts from points. These results are motivated by an open problem on the dimensions of visible parts.

  3. Non-Euclidean Visibility Problems

    Indian Academy of Sciences (India)

    Fernando Chamizo

    2006-05-01

    We consider the analog of visibility problems in hyperbolic plane (represented by Poincaré half-plane model $\\mathbb{H}$), replacing the standard lattice $\\mathbb{Z} × \\mathbb{Z}$ by the orbit = under the full modular group $SL_2(\\mathbb{Z})$. We prove a visibility criterion and study orchard problem and the cardinality of visible points in large circles.

  4. Visibility of comet nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Ney, E.P.

    1982-01-22

    Photography of the nucleus of comet Halley is the goal of several planned space missions. The nucleus of a comet is surrounded by a cloud of dust particles. If this cloud is optically thick, it will prevent observation of the nuclear surface. Broadband photometry of nine comets has been analyzed to determine the visibility of their nuclei. Only in the case of comet West near perihelion was the dust dense enough to interfere with imaging. Comparison of the visual brightness of the well-observed comets with that of Halley in 1910 leads to the conclusion that the nucleus of Halley can be imaged without significant obscuration by the dust.

  5. On court interpreters' visibility

    DEFF Research Database (Denmark)

    Dubslaff, Friedel; Martinsen, Bodil

    This paper is part of the initial stage of a larger empirical research project on court interpreting seen as a complex interaction between (at least) three co-participants. The empirical material consists of recordings of interpreted interrogations in court room settings and questionnaires filled...... of the service they receive. Ultimately, the findings will be used for training purposes. Future - and, for that matter, already practising - interpreters as well as the professional users of interpreters ought to take the reality of the interpreters' work in practice into account when assessing the quality...... of the service rendered/received. The paper presents a small-scale case study based on an interpreted witness interrogation. Recent research on the interpreter's role has shown that interpreters across all settings perceive themselves as "visible" (Angelelli 2003, 2004). This has led us to focus...

  6. Infrared Spectroscopy with Visible Light

    CERN Document Server

    Kalashnikov, Dmitry A; Kulik, Sergei P; Krivitsky, Leonid A

    2015-01-01

    Spectral measurements in the infrared (IR) optical range provide unique fingerprints of materials which are useful for material analysis, environmental sensing, and health diagnostics. Current IR spectroscopy techniques require the use of optical equipment suited for operation in the IR range, which faces challenges of inferior performance and high cost. Here we develop a spectroscopy technique, which allows spectral measurements in the IR range using visible spectral range components. The technique is based on nonlinear interference of infrared and visible photons, produced via Spontaneous Parametric Down Conversion (SPDC). The intensity interference pattern for a visible photon depends on the phase of an IR photon, which travels through the media. This allows determining properties of the media in the IR range from the measurements of visible photons. The technique can substitute and/or complement conventional IR spectroscopy techniques, as it uses well-developed optical components for the visible range.

  7. On characterizing terrain visibility graphs

    Directory of Open Access Journals (Sweden)

    William Evans

    2015-06-01

    Full Text Available A terrain is an $x$-monotone polygonal line in the $xy$-plane. Two vertices of a terrain are mutually visible if and only if there is no terrain vertex on or above the open line segment connecting them. A graph whose vertices represent terrain vertices and whose edges represent mutually visible pairs of terrain vertices is called a terrain visibility graph. We would like to find properties that are both necessary and sufficient for a graph to be a terrain visibility graph; that is, we would like to characterize terrain visibility graphs.Abello et al. [Discrete and Computational Geometry, 14(3:331--358, 1995] showed that all terrain visibility graphs are “persistent”. They showed that the visibility information of a terrain point set implies some ordering requirements on the slopes of the lines connecting pairs of points in any realization, and as a step towards showing sufficiency, they proved that for any persistent graph $M$ there is a total order on the slopes of the (pseudo lines in a generalized configuration of points whose visibility graph is $M$.We give a much simpler proof of this result by establishing an orientation to every triple of vertices, reflecting some slope ordering requirements that are consistent with $M$ being the visibility graph, and prove that these requirements form a partial order. We give a faster algorithm to construct a total order on the slopes. Our approach attempts to clarify the implications of the graph theoretic properties on the ordering of the slopes, and may be interpreted as defining properties on an underlying oriented matroid that we show is a restricted type of $3$-signotope.

  8. vysmaw: Fast visibility stream muncher

    Science.gov (United States)

    Pokorny, Martin; Law, Casey J.

    2017-10-01

    The vysmaw client library facilitates the development of code for processes to tap into the fast visibility stream on the National Radio Astronomy Observatory's Very Large Array correlator back-end InfiniBand network.

  9. Negative Refraction at Visible Frequencies

    National Research Council Canada - National Science Library

    Henri J. Lezec; Jennifer A. Dionne; Harry A. Atwater

    2007-01-01

    .... We demonstrate an experimental realization of a two-dimensional negative-index material in the blue-green region of the visible spectrum, substantiated by direct geometric visualization of negative refraction...

  10. Visible neutrino decay at DUNE

    Energy Technology Data Exchange (ETDEWEB)

    Coloma, Pilar [Fermilab; Peres, Orlando G. [ICTP, Trieste

    2017-05-09

    If the heaviest neutrino mass eigenstate is unstable, its decay modes could include lighter neutrino eigenstates. In this case part of the decay products could be visible, as they would interact at neutrino detectors via mixing. At neutrino oscillation experiments, a characteristic signature of such \\emph{visible neutrino decay} would be an apparent excess of events at low energies. We focus on a simple phenomenological model in which the heaviest neutrino decays as $\

  11. Solar synthesis: prospects in visible light photocatalysis

    National Research Council Canada - National Science Library

    Schultz, Danielle M; Yoon, Tehshik P

    2014-01-01

    .... Nevertheless, the use of visible light in photochemical synthesis is fundamentally challenging because organic molecules tend not to interact with the wavelengths of visible light that are most...

  12. gastric pneumatosis or emphysematous gastritis?

    African Journals Online (AJOL)

    with a history of thoracic and abdominal surgery who presented with intractable vomiting ... ings in adult and paediatric populations. Case report. A female ... A chest X-ray demonstrated a large mass adjacent to the right hemi-diaphragm.

  13. Early Learning Theories Made Visible

    Science.gov (United States)

    Beloglovsky, Miriam; Daly, Lisa

    2015-01-01

    Go beyond reading about early learning theories and see what they look like in action in modern programs and teacher practices. With classroom vignettes and colorful photographs, this book makes the works of Jean Piaget, Erik Erikson, Lev Vygotsky, Abraham Maslow, John Dewey, Howard Gardner, and Louise Derman-Sparks visible, accessible, and easier…

  14. Magnetic Fields: Visible and Permanent.

    Science.gov (United States)

    Winkeljohn, Dorothy R.; Earl, Robert D.

    1983-01-01

    Children will be able to see the concept of a magnetic field translated into a visible reality using the simple method outlined. Standard shelf paper, magnets, iron filings, and paint in a spray can are used to prepare a permanent and well-detailed picture of the magnetic field. (Author/JN)

  15. Early Learning Theories Made Visible

    Science.gov (United States)

    Beloglovsky, Miriam; Daly, Lisa

    2015-01-01

    Go beyond reading about early learning theories and see what they look like in action in modern programs and teacher practices. With classroom vignettes and colorful photographs, this book makes the works of Jean Piaget, Erik Erikson, Lev Vygotsky, Abraham Maslow, John Dewey, Howard Gardner, and Louise Derman-Sparks visible, accessible, and easier…

  16. Incremental Visualizer for Visible Objects

    DEFF Research Database (Denmark)

    Bukauskas, Linas; Bøhlen, Michael Hanspeter

    This paper discusses the integration of database back-end and visualizer front-end into a one tightly coupled system. The main aim which we achieve is to reduce the data pipeline from database to visualization by using incremental data extraction of visible objects in a fly-through scenarios. We...

  17. Ultraviolet, Visible, and Fluorescence Spectroscopy

    Science.gov (United States)

    Penner, Michael H.

    Spectroscopy in the ultraviolet-visible (UV-Vis) range is one of the most commonly encountered laboratory techniques in food analysis. Diverse examples, such as the quantification of macrocomponents (total carbohydrate by the phenol-sulfuric acid method), quantification of microcomponents, (thiamin by the thiochrome fluorometric procedure), estimates of rancidity (lipid oxidation status by the thiobarbituric acid test), and surveillance testing (enzyme-linked immunoassays), are presented in this text. In each of these cases, the analytical signal for which the assay is based is either the emission or absorption of radiation in the UV-Vis range. This signal may be inherent in the analyte, such as the absorbance of radiation in the visible range by pigments, or a result of a chemical reaction involving the analyte, such as the colorimetric copper-based Lowry method for the analysis of soluble protein.

  18. Ultraviolet-visible nanophotonic devices

    OpenAIRE

    2010-01-01

    Ankara : The Department of Electrical and Electronics Engineering and the Institute of Engineering and Sciences of Bilkent University, 2010. Thesis (Ph. D.) -- Bilkent University, 2010. Includes bibliographical references leaves 130-141. Recently in semiconductor market, III-Nitride materials and devices are of much interest due to their mechanical strength, radiation resistance, working in the spectrum from visible down to the deep ultraviolet region and solar-blind device ...

  19. Computing Visible-Surface Representations,

    Science.gov (United States)

    1985-03-01

    Terzopoulos N00014-75-C-0643 9. PERFORMING ORGANIZATION NAME AMC ADDRESS 10. PROGRAM ELEMENT. PROJECT, TASK Artificial Inteligence Laboratory AREA A...Massachusetts Institute of lechnolog,. Support lbr the laboratory’s Artificial Intelligence research is provided in part by the Advanced Rtccarcl Proj...dynamically maintaining visible surface representations. Whether the intention is to model human vision or to design competent artificial vision systems

  20. Visual quality beyond artifact visibility

    Science.gov (United States)

    Redi, Judith A.

    2013-03-01

    The Electronic imaging community has devoted a lot of effort to the development of technologies that can predict the visual quality of images and videos, as a basis for the delivery of optimal visual quality to the user. These systems have been based for the most part on a visibility-centric approach, assuming the more artifacts are visible, the higher is the annoyance they provoke, the lower the visual quality. Despite the remarkable results achieved with this approach, recently a number of studies suggested that the visibility-centric approach to visual quality might have limitations, and that other factors might influence the overall quality impression of an image or video, depending on cognitive and affective mechanisms that work on top of perception. In particular, interest in the visual content, engagement and context of usage have been found to impact on the overall quality impression of the image/video. In this paper, we review these studies and explore the impact that affective and cognitive processes have on the visual quality. In addition, as a case study, we present the results of an experiment investigating on the impact of aesthetic appeal on visual quality, and we show that users tend to be more demanding in terms of visual quality judging beautiful images.

  1. Morbilidad y mortalidad en la cirugía de las bullas enfisematosas Morbidity and mortality in the surgery of emphysematous bullae

    Directory of Open Access Journals (Sweden)

    Kai Cheng Hung

    2008-03-01

    compared with that occasioned by the impossibility of breathing adequately. The aim of this paper was to study the pulmonary bullous disease treated with surgery, according to the working algorithm created at "Comandante Manuel Fajardo" Hospital. METHODS. 36 patients operated on from 1995 to 2004 were prospectively studied. To clinically determine the state of the patients in the preoperative and postoperative, it was used the dyspnea index recommended by the American Thorax Society. Surgical risk was assessed according to the classification of the American Society of Anesthesia and the Goldman's index for cardiac risk in non-cardiac surgery. RESULTS. The main indications of the surgical treatment in the patients with emphysematous bullae were the giant bullae and the bullous pneumothorax (92 %. The morbidity of surgical interventions was very high (61.1 %. Most of them were not important. The air leak was the most frequent of the complications (22.2 %, followed by seroma of the surgical wound (11.1 %. Mortality was low (2.8 %, with only one dead due to an acute respiratory failure. CONCLUSIONS. Bullectomy with atypical resection is the preferred surgical technique to preserve the greatest amount of functional pulmonary tissue. The dyspnea index showed a remarkable improvement between the pre- and postoperative evaluations of the pulmonary function. We considered that this indicator is higher than the forced expiratory volume in the first second (FEV1 for the assessment of surgery effectivity and that it is also an excellent marker of the improvement of the quality of life of the patients

  2. Beyond Language Equivalence on Visibly Pushdown Automata

    DEFF Research Database (Denmark)

    Srba, Jiri

    2009-01-01

    We study (bi)simulation-like preorder/equivalence checking on the class of visibly pushdown automata and its natural subclasses visibly BPA (Basic Process Algebra) and visibly one-counter automata. We describe generic methods for proving complexity upper and lower bounds for a number of studied...

  3. 60 years of UK visibility measurements: impact of meteorology and atmospheric pollutants on visibility

    OpenAIRE

    Singh, Ajit; Bloss, William J.; Pope, Francis D.

    2016-01-01

    Reduced visibility is an indicator of poor air quality. Moreover, degradation in visibility can be hazardous to human safety; for example, low visibility can lead to road, rail, sea and air accidents. In this paper, we explore the combined influence of atmospheric aerosol particle and gas characteristics, and meteorology, on long-term visibility. We use visibility data from eight meteorological stations, situated in the UK, which have been running since the 1950s. The site locations include u...

  4. Visible light broadband perfect absorbers

    Energy Technology Data Exchange (ETDEWEB)

    Jia, X. L.; Meng, Q. X.; Yuan, C. X.; Zhou, Z. X.; Wang, X. O., E-mail: wxo@hit.edu.cn [School of Science, Harbin Institute of Technology, Harbin 150001 (China)

    2016-03-15

    The visible light broadband perfect absorbers based on the silver (Ag) nano elliptical disks and holes array are studied using finite difference time domain simulations. The semiconducting indium silicon dioxide thin film is introduced as the space layer in this sandwiched structure. Utilizing the asymmetrical geometry of the structures, polarization sensitivity for transverse electric wave (TE)/transverse magnetic wave (TM) and left circular polarization wave (LCP)/right circular polarization wave (RCP) of the broadband absorption are gained. The absorbers with Ag nano disks and holes array show several peaks absorbance of 100% by numerical simulation. These simple and flexible perfect absorbers are particularly desirable for various potential applications including the solar energy absorber.

  5. Solar Synthesis: Prospects in Visible Light Photocatalysis

    OpenAIRE

    Schultz, Danielle M.; Yoon, Tehshik P.

    2014-01-01

    Chemists have long aspired to synthesize molecules the way that plants do — using sunlight to facilitate the construction of complex molecular architectures. Nevertheless, the use of visible light in photochemical synthesis is fundamentally challenging because organic molecules tend not to interact with the wavelengths of visible light that are most strongly emitted in the solar spectrum. Recent research has begun to leverage the ability of visible light absorbing transition metal complexes t...

  6. Visible-frequency hyperbolic metasurface

    Science.gov (United States)

    High, Alexander A.; Devlin, Robert C.; Dibos, Alan; Polking, Mark; Wild, Dominik S.; Perczel, Janos; de Leon, Nathalie P.; Lukin, Mikhail D.; Park, Hongkun

    2015-06-01

    Metamaterials are artificial optical media composed of sub-wavelength metallic and dielectric building blocks that feature optical phenomena not present in naturally occurring materials. Although they can serve as the basis for unique optical devices that mould the flow of light in unconventional ways, three-dimensional metamaterials suffer from extreme propagation losses. Two-dimensional metamaterials (metasurfaces) such as hyperbolic metasurfaces for propagating surface plasmon polaritons have the potential to alleviate this problem. Because the surface plasmon polaritons are guided at a metal-dielectric interface (rather than passing through metallic components), these hyperbolic metasurfaces have been predicted to suffer much lower propagation loss while still exhibiting optical phenomena akin to those in three-dimensional metamaterials. Moreover, because of their planar nature, these devices enable the construction of integrated metamaterial circuits as well as easy coupling with other optoelectronic elements. Here we report the experimental realization of a visible-frequency hyperbolic metasurface using single-crystal silver nanostructures defined by lithographic and etching techniques. The resulting devices display the characteristic properties of metamaterials, such as negative refraction and diffraction-free propagation, with device performance greatly exceeding those of previous demonstrations. Moreover, hyperbolic metasurfaces exhibit strong, dispersion-dependent spin-orbit coupling, enabling polarization- and wavelength-dependent routeing of surface plasmon polaritons and two-dimensional chiral optical components. These results open the door to realizing integrated optical meta-circuits, with wide-ranging applications in areas from imaging and sensing to quantum optics and quantum information science.

  7. 全胸腔镜非切割闭合器手术治疗巨型肺大疱临床研究%Clinical research of Non-GIA complete video-assisted thoracic surgery for giant emphysematous bullae

    Institute of Scientific and Technical Information of China (English)

    万来忆; 王强; 吴勇; 曾光; 曹睿; 肖明第

    2015-01-01

    Objective To discuss the effectiveness,feasibility and dependability of Non-GIA complete video-assisted thoracic surgery for giant emphysematous bullae,to describe the surgery details, and to summarize the advantages of the proposed method. Methods The clinical profiles of 59 patients treated at the Department of Thoracic Surgery in Shanghai Yodak Cardiothoracic Hospital during March 2008 to November 2014 were reviewed. Among these patients,35 with multiple bullae or financial problems were treated with Non-GIA surgery while the rest were treated with Endo-GIA as control. Particularly, differences in surgery effect,cost and long-term effect were of our focus. Results Surgeries of all these 59 patients went smoothly and 35 of them were treated with Non-GIA cVATS;no thoracotomy was conducted for any patient,and satisfactory surgical results were observed. 56 patients are followed up for 3 ~79 months after the surgery. The reviewed patients demonstrated lower level of MRC and enhancement in mov-ing capability,and also no more pneumothorax or bullae was observed after the surgery. Although the re-sults of the two groups were similar,the Non-GIA group had an apparent advantage in the cost. Conclusion Non-GIA cVATS is a dependable and feasible surgery for the treatment of giant emphysematous bul-lae. In surgery,the direct cut-out of the bullae and suture of leakage of the basement can maximally pre-serve the normal lung tissue. This surgery method shows good long-term effect and has a significant lower cost compared with Endo-GIA method,and thus can serve as a suitable choice for patients with multiple bullae or finical difficulties.%目的:探讨全胸腔镜非切割闭合器( Non-GIA)手术治疗巨型肺大疱的手术效果及安全可行性,总结手术方法和优势。方法收集巨型肺大疱患者59例,对35例肺大疱多发或经济较困难者行全胸腔镜Non-GIA手术,余24例使用内镜直线切割闭合器( Endo-GIA)作为对照组。

  8. Impaired visibility: the air pollution people see

    Science.gov (United States)

    Hyslop, Nicole Pauly

    Almost every home and office contains a portrayal of a scenic landscape whether on a calendar, postcard, photograph, or painting. The most sought after locations boast a scenic landscape right outside their window. No matter what the scene - mountains, skyscrapers, clouds, or pastureland - clarity and vividness are essential to the image. Air pollution can degrade scenic vistas, and in extreme cases, completely obscure them. Particulate matter suspended in the air is the main cause of visibility degradation. Particulate matter affects visibility in multiple ways: obscures distant objects, drains the contrast from a scene, and discolors the sky. Visibility is an environmental quality that is valued for aesthetic reasons that are difficult to express or quantify. Human psychology and physiology are sensitive to visual input. Visibility has been monitored throughout the world but there are few places where it is a protected resource. Existing health-based regulations are weak in terms of visibility protection. Various techniques, including human observation, light transmission measurements, digital photography, and satellite imaging, are used to monitor visibility. As with air pollution, trends in visibility vary spatially and temporally. Emissions from the developing world and large scale events such as dust storms and wildfires affect visibility around much of the globe.

  9. Rendering Visible: Painting and Sexuate Subjectivity

    Science.gov (United States)

    Daley, Linda

    2015-01-01

    In this essay, I examine Luce Irigaray's aesthetic of sexual difference, which she develops by extrapolating from Paul Klee's idea that the role of painting is to render the non-visible rather than represent the visible. This idea is the premise of her analyses of phenomenology and psychoanalysis and their respective contributions to understanding…

  10. Rendering Visible: Painting and Sexuate Subjectivity

    Science.gov (United States)

    Daley, Linda

    2015-01-01

    In this essay, I examine Luce Irigaray's aesthetic of sexual difference, which she develops by extrapolating from Paul Klee's idea that the role of painting is to render the non-visible rather than represent the visible. This idea is the premise of her analyses of phenomenology and psychoanalysis and their respective contributions to understanding…

  11. Sequential motif profile of natural visibility graphs

    CERN Document Server

    Iacovacci, Jacopo

    2016-01-01

    The concept of sequential visibility graph motifs -subgraphs appearing with characteristic frequencies in the visibility graphs associated to time series- has been advanced recently along with a theoretical framework to compute analytically the motif profiles associated to Horizontal Visibility Graphs (HVGs). Here we develop a theory to compute the profile of sequential visibility graph motifs in the context of Natural Visibility Graphs (VGs). This theory gives exact results for deterministic aperiodic processes with a smooth invariant density or stochastic processes that fulfil the Markov property and have a continuous marginal distribution. The framework also allows for a linear time numerical estimation in the case of empirical time series. A comparison between the HVG and the VG case (including evaluation of their robustness for short series polluted with measurement noise) is also presented.

  12. A Proposed Multi Images Visible Watermarking Technique

    Directory of Open Access Journals (Sweden)

    Ruba G. Al-Zamil

    2016-04-01

    Full Text Available Visible watermarking techniques are proposed to secure digital data against unauthorized attacks. These techniques protect data from illegal access and use. In this work, a multi visible watermarking technique that allows embedding different types of markers into different types of background images has been proposed It also allows adding multiple markers on the same background image with different sizes, positions and opacity levels without any interference. The proposed technique improves the flexibility issues of visible watermarking and helps in increasing the security levels. A visible watermarking system is designed to implement the proposed technique. The system facilitates single and multiple watermarking as illustrated in the proposed technique. Experimental results indicate that the proposed technique applies visible watermarking successfully.

  13. No-visible-scar cholecystectomy

    Directory of Open Access Journals (Sweden)

    Tadeusz M. Wróblewski

    2010-12-01

    Full Text Available Introduction: Single incision laparoscopic surgery (SILS is a laparoscopic method providing a good cosmetic effect,but requiring the application of special ports and instruments enabling the surgeon to perform the procedure.We report three-ports cholecystectomy through umbilical and suprapubic incisions performed with typical laparos -copic instruments which calls no-visible-scar cholecystectomy (NVSC.Material and methods: Twenty patients with symptomatic cholelithiasis were qualified for NVSC. Typical CO2 pneumoperitoneumwas done after umbilical skin incision. Two ports of 5 mm were inserted in the maximum externaledges of this incision. After cystic duct and cystic artery dissection the right one was exchanged for a port of 11 mm.The second incision for the 11-mm trocar for the laparoscope was done in the suprapubic median line within the hairarea.Results: Cholecystectomies were performed without any conversion to classical laparoscopic cholecystectomy (LCHor open surgery. They were not technically identical due to the gradual improvement in the access and manipulationof instruments. The time of the intervention ranged from 2 hours during the introduction of the new method to 50 minfor the last procedures. No postoperative complications were observed and all patients were discharged not later thanafter conventional LCH.Conclusions: NVSC is a three-port laparoscopic intervention performed with typical laparoscopic instruments. It ismore convenient for the surgeon than single incision LCH, because the placement of the optic in the suprapubic regiongives more space for the instruments. It also provides a very good cosmetic effect of the intervention. The describedprocedure is easy to learn and in case of technical problems additional ports can be applied (as in typical LCH.

  14. Intraseasonal variation of visibility in Hong Kong

    Science.gov (United States)

    Zhou, Wen; Li, Richard C. Y.; Chow, Eric C. H.

    2017-01-01

    Visibility is one of the parameters for indicating air pollution. In this study, visibility variation in Hong Kong during summer and winter is investigated. Visibility in Hong Kong has clear intraseasonal variation. Examination of different environmental parameters suggests that the intraseasonal component dominates the overall circulation anomalies in both summer and winter. Associated with the intraseasonal variation of environmental parameters, obvious variation in visibility impairment is found in both summer and winter. In summer, local visibility and air quality are found to be significantly affected by the (MJO) and the 10-30-day intraseasonal oscillation (ISO) through modulation of associated atmospheric circulations. In winter, the modulation effects appear to be weaker due to the southward shift of the associated convection. The results in this study highlight the importance of the ISO in contributing to the overall variation in visibility in Hong Kong, and provide useful implications for the development of possible mitigation strategies associated with visibility impairment and air pollution in Hong Kong.

  15. The challenge of improving visibility in Beijing

    Directory of Open Access Journals (Sweden)

    Q. Zhang

    2010-03-01

    Full Text Available The "Blue Sky Project" was proposed in 1998 to investigate by how much emissions should be reduced to increase blue sky frequency in Beijing, which hosted the Summer Olympics in 2008. This paper focuses on the temporal variation of visibility and its dependence on meteorological conditions and suspended particles at Beijing using the hourly observed visibility data in Beijing Capital International Airport (BCIA from 1999 to 2007. It has been found that about 47.8% (24.2% of the hours in Beijing are "bad" ("good" hours with visibility below 10 km (equal or higher than 20 km between 1999 and 2007. Due to the high Relative Humidity (RH, summer is the season with the lowest mean visibility in a year. Although PM10 index was reported in a decreasing trend, the increase of RH has resulted in a decreasing trend of visibility over BCIA in the summer from 1999 to 2007. To ensure blue sky ("good" visibility for Olympics 2008, daily mean PM10 index should be reduced to 44 from 86.5. This requires that not only vehicle emissions, but also other emissions should be limited. Observations during Olympics 2008 verify that blue-sky-hour rate has been increased significantly after mean PM10 index was reduced to 56, however, the visibility during the same period of 2009 has returned to the mean standard before 2008.

  16. Chloroquine is grossly under dosed in young children with malaria

    DEFF Research Database (Denmark)

    Ursing, Johan; Eksborg, Staffan; Rombo, Lars

    2014-01-01

    BACKGROUND: Plasmodium falciparum malaria is treated with 25 mg/kg of chloroquine (CQ) irrespective of age. Theoretically, CQ should be dosed according to body surface area (BSA). The effect of dosing CQ according to BSA has not been determined but doubling the dose per kg doubled the efficacy of...

  17. Robust Lasso with missing and grossly corrupted observations

    CERN Document Server

    Nguyen, Nam H

    2011-01-01

    This paper studies the problem of accurately recovering a sparse vector $\\beta^{\\star}$ from highly corrupted linear measurements $y = X \\beta^{\\star} + e^{\\star} + w$ where $e^{\\star}$ is a sparse error vector whose nonzero entries may be unbounded and $w$ is a bounded noise. We propose a so-called extended Lasso optimization which takes into consideration sparse prior information of both $\\beta^{\\star}$ and $e^{\\star}$. Our first result shows that the extended Lasso can faithfully recover both the regression as well as the corruption vector. Our analysis relies on the notion of extended restricted eigenvalue for the design matrix $X$. Our second set of results applies to a general class of Gaussian design matrix $X$ with i.i.d rows $\\oper N(0, \\Sigma)$, for which we can establish a surprising result: the extended Lasso can recover exact signed supports of both $\\beta^{\\star}$ and $e^{\\star}$ from only $\\Omega(k \\log p \\log n)$ observations, even when the fraction of corruption is arbitrarily close to one. O...

  18. Glassfiber Post: An Alternative for Restoring Grossly Decayed Primary Incisors

    OpenAIRE

    Mehra, Manjul; Grover, Rashu

    2012-01-01

    ABSTRACT Restoration of primary incisors, which have been severely damaged by rampant caries or trauma, is a difficult task for the pediatric dentist. With the introduction of new adhesive systems and restorative materials, alternative approaches for treating these teeth have been proposed. This paper discusses the restoration of carious primary maxillary incisors using composite resin restoration reinforced with fiberglass post. Two case reports are presented here to describe the procedure. ...

  19. Rare Cadaveric Finding of a Grossly Enlarged Mucocele Appendix

    Directory of Open Access Journals (Sweden)

    Anna Farias

    2013-12-01

    Full Text Available Appendicular mucoceles are rare clinical findings characterized by dilation and distention of the appendicular lumen by the accumulation of mucus. Their discovery is often incidental from abdominal imaging or more commonly as a secondary surgical finding. In this case study we report the first known recorded case of a cadaveric mucocele appendix discovered during routine dissection of the gastrointestinal system. The recorded cause of death for the 86-year-old female patient was congestive heart failure. We compared the gross anatomy and histology of this enormous appendix with another cadaveric appendix. A pathology report identified the appendicular mucocele as a mucinous cystadenoma.

  20. Massive yet grossly underestimated global costs of invasive insects

    Science.gov (United States)

    Bradshaw, Corey J. A.; Leroy, Boris; Bellard, Céline; Roiz, David; Albert, Céline; Fournier, Alice; Barbet-Massin, Morgane; Salles, Jean-Michel; Simard, Frédéric; Courchamp, Franck

    2016-10-01

    Insects have presented human society with some of its greatest development challenges by spreading diseases, consuming crops and damaging infrastructure. Despite the massive human and financial toll of invasive insects, cost estimates of their impacts remain sporadic, spatially incomplete and of questionable quality. Here we compile a comprehensive database of economic costs of invasive insects. Taking all reported goods and service estimates, invasive insects cost a minimum of US$70.0 billion per year globally, while associated health costs exceed US$6.9 billion per year. Total costs rise as the number of estimate increases, although many of the worst costs have already been estimated (especially those related to human health). A lack of dedicated studies, especially for reproducible goods and service estimates, implies gross underestimation of global costs. Global warming as a consequence of climate change, rising human population densities and intensifying international trade will allow these costly insects to spread into new areas, but substantial savings could be achieved by increasing surveillance, containment and public awareness.

  1. High Density Metamaterials for Visible Light

    Science.gov (United States)

    2016-11-28

    Split Ring Resonator Metamaterials with Fundamental Magnetic Resonance in the Middle Visible Spectrum,” Adv. Opt. Mater., vol. 2, no. 3, pp. 280–285...AFRL-AFOSR-JP-TR-2016-0097 High density metamaterials for visible light Dao Hua Zhang NANYANG TECHNOLOGICAL UNIVERSITY Final Report 11/28/2016...COVERED (From - To)  16 Jul 2014 to 15 Jul 2016 4. TITLE AND SUBTITLE High density metamaterials for visible light 5a.  CONTRACT NUMBER 5b.  GRANT

  2. Visible Spectrum Incandescent Selective Emitter

    Energy Technology Data Exchange (ETDEWEB)

    Sonsight Inc.

    2004-04-30

    The purpose of the work performed was to demonstrate the feasibility of a novel bi-layer selective emitter. Selective emitters are incandescent radiant bodies with emissivities that are substantially larger in a selected part of the radiation spectrum, thereby significantly shifting their radiated spectral distribution from that of a blackbody radiating at the same temperature. The major research objectives involved answering the following questions: (1) What maximum VIS/NIR radiant power and emissivity ratios can be attained at 2650 K? (2) What is the observed emitter body life and how does its performance vary with time? (3) What are the design tradeoffs for a dual heating approach in which both an internally mounted heating coil and electrical resistance self-heating are used? (4) What are the quantitative improvements to be had from utilizing a bi-layer emitter body with a low emissivity inner layer and a partially transmissive outer layer? Two approaches to obtaining selective emissivity were investigated. The first was to utilize large optical scattering within an emitter material with a spectral optical absorption that is much greater within the visible spectrum than that within the NIR. With this approach, an optically thick emitter can radiate almost as if optically thin because essentially, scattering limits the distance below the surface from which significant amounts of internally generated radiation can emerge. The performance of thin emitters was also investigated (for optically thin emitters, spectral emissivity is proportional to spectral absorptivity). These emitters were fabricated from thin mono-layer emitter rods as well as from bi-layer rods with a thin emitter layer mounted on a substrate core. With an initially estimated energy efficiency of almost three times that of standard incandescent bulbs, a number of energy, economic and environmental benefits such as less energy use and cost, reduced CO{sub 2} emissions, and no mercury contamination

  3. White LED visible light communication technology research

    Science.gov (United States)

    Yang, Chao

    2017-03-01

    Visible light communication is a new type of wireless optical communication technology. White LED to the success of development, the LED lighting technology is facing a new revolution. Because the LED has high sensitivity, modulation, the advantages of good performance, large transmission power, can make it in light transmission light signal at the same time. Use white LED light-emitting characteristics, on the modulation signals to the visible light transmission, can constitute a LED visible light communication system. We built a small visible optical communication system. The system composition and structure has certain value in the field of practical application, and we also research the key technology of transmitters and receivers, the key problem has been resolved. By studying on the optical and LED the characteristics of a high speed modulation driving circuit and a high sensitive receiving circuit was designed. And information transmission through the single chip microcomputer test, a preliminary verification has realized the data transmission function.

  4. Broadband Visible Light Induced NO Formation

    Science.gov (United States)

    Lubart, Rachel; Eichler, Maor; Friedmann, Harry; Savion, N.; Breitbart, Haim; Ankri, Rinat

    2009-06-01

    Nitric oxide formation is a potential mechanism for photobiomodulation because it is synthesized in cells by nitric oxide synthase (NOS), which contains both flavin and heme, and thus absorbs visible light. The purpose of this work was to study broadband visible light induced NO formation in various cells. Cardiac, endothelial, sperm cells and RAW 264.7 macrophages were illuminated with broadband visible light, 40-130 mW/cm2, 2.4-39 J/cm2, and nitric oxide production was quantified by using the Griess reagent. The results showed that visible light illumination increased NO concentration both in sperm and endothelial cells, but not in cardiac cells. Activation of RAW 264.7 macrophages was very small. It thus appears that NO is involved in photobiomodulation, though different light parameters and illumination protocols are needed to induce NO in various cells.

  5. Visible Spectrophotometric and Thermodynamic Studies of Diclofenac

    African Journals Online (AJOL)

    Purpose: To investigate the visible spectrophotometric and thermodynamic parameters of diclofenac with regard to ... The drug content of commercial diclofenac products to which the assay method was applied was between 94 ..... application.

  6. Visibility of noisy point cloud data

    KAUST Repository

    Mehra, Ravish

    2010-06-01

    We present a robust algorithm for estimating visibility from a given viewpoint for a point set containing concavities, non-uniformly spaced samples, and possibly corrupted with noise. Instead of performing an explicit surface reconstruction for the points set, visibility is computed based on a construction involving convex hull in a dual space, an idea inspired by the work of Katz et al. [26]. We derive theoretical bounds on the behavior of the method in the presence of noise and concavities, and use the derivations to develop a robust visibility estimation algorithm. In addition, computing visibility from a set of adaptively placed viewpoints allows us to generate locally consistent partial reconstructions. Using a graph based approximation algorithm we couple such reconstructions to extract globally consistent reconstructions. We test our method on a variety of 2D and 3D point sets of varying complexity and noise content. © 2010 Elsevier Ltd. All rights reserved.

  7. Solar synthesis: prospects in visible light photocatalysis.

    Science.gov (United States)

    Schultz, Danielle M; Yoon, Tehshik P

    2014-02-28

    Chemists have long aspired to synthesize molecules the way that plants do-using sunlight to facilitate the construction of complex molecular architectures. Nevertheless, the use of visible light in photochemical synthesis is fundamentally challenging because organic molecules tend not to interact with the wavelengths of visible light that are most strongly emitted in the solar spectrum. Recent research has begun to leverage the ability of visible light-absorbing transition metal complexes to catalyze a broad range of synthetically valuable reactions. In this review, we highlight how an understanding of the mechanisms of photocatalytic activation available to these transition metal complexes, and of the general reactivity patterns of the intermediates accessible via visible light photocatalysis, has accelerated the development of this diverse suite of reactions.

  8. Feature point descriptors: infrared and visible spectra

    National Research Council Canada - National Science Library

    Ricaurte, Pablo; Chilán, Carmen; Aguilera-Carrasco, Cristhian A; Vintimilla, Boris X; Sappa, Angel D

    2014-01-01

    This manuscript evaluates the behavior of classical feature point descriptors when they are used in images from long-wave infrared spectral band and compare them with the results obtained in the visible spectrum...

  9. Mutagenesis by near-visible light.

    Science.gov (United States)

    Kubitschek, H E

    1967-03-24

    Mutants resistant to bacter iophage T5 were produced both in continuous and in stationary cultures of Escherichia coli by near-visible light, 320 to 400 millimicrons, at rates greatly exceeding spontaneous rates in the ab sence of light. Aerobic mutation rates were about twice anaerobic rates, which shows that mutations were induced in either of at least two different proces ses. Mutations induced by near-visible light involve different photochemical processes than those induced by ul traviolet light.

  10. The challenge of improving visibility in Beijing

    Directory of Open Access Journals (Sweden)

    Q. H. Zhang

    2010-08-01

    Full Text Available The "Blue Sky Project" was proposed in 1998 to investigate by how much emissions should be reduced to increase blue sky frequency in Beijing, which hosted the Summer Olympics in 2008. This paper focuses on the temporal variation of visibility and its dependence on meteorological conditions and suspended particles at Beijing using the hourly observed visibility data at Beijing Capital International Airport (BCIA from 1999 to 2007. It has been found that about 47.8% (24.2% of the hours in Beijing are "bad" ("good" hours with visibility below 10 km (equal or higher than 20 km between 1999 and 2007. Due to the high Relative Humidity (RH, summer is the season with the lowest mean visibility in a year. Although PM10 index was reported in a decreasing trend (Chan and Yao, 2008, the increase of RH has resulted in a decreasing trend of visibility over BCIA in the summer from 1999 to 2007. To ensure blue sky ("good" visibility for Olympics 2008, daily mean PM10 index should have been reduced from 81 to 44. This requires that not only vehicle emissions, but also other emissions should be limited. Observations verify that blue-sky-hour rate increased significantly after mean PM10 index was reduced to 53 during Olympics 2008, however, the visibility of 2009 returned to the mean level from 1999 to 2007 during the period 8−24 August. RH (aerosol contribute 24% (76% of the improvement of visibility during August 2008.

  11. A climatology of visible surface reflectance spectra

    Science.gov (United States)

    Zoogman, Peter; Liu, Xiong; Chance, Kelly; Sun, Qingsong; Schaaf, Crystal; Mahr, Tobias; Wagner, Thomas

    2016-09-01

    We present a high spectral resolution climatology of visible surface reflectance as a function of wavelength for use in satellite measurements of ozone and other atmospheric species. The Tropospheric Emissions: Monitoring of Pollution (TEMPO) instrument is planned to measure backscattered solar radiation in the 290-740 nm range, including the ultraviolet and visible Chappuis ozone bands. Observation in the weak Chappuis band takes advantage of the relative transparency of the atmosphere in the visible to achieve sensitivity to near-surface ozone. However, due to the weakness of the ozone absorption features this measurement is more sensitive to errors in visible surface reflectance, which is highly variable. We utilize reflectance measurements of individual plant, man-made, and other surface types to calculate the primary modes of variability of visible surface reflectance at a high spectral resolution, comparable to that of TEMPO (0.6 nm). Using the Moderate-resolution Imaging Spectroradiometer (MODIS) Bidirection Reflectance Distribution Function (BRDF)/albedo product and our derived primary modes we construct a high spatial resolution climatology of wavelength-dependent surface reflectance over all viewing scenes and geometries. The Global Ozone Monitoring Experiment-2 (GOME-2) Lambertian Equivalent Reflectance (LER) product provides complementary information over water and snow scenes. Preliminary results using this approach in multispectral ultraviolet+visible ozone retrievals from the GOME-2 instrument show significant improvement to the fitting residuals over vegetated scenes.

  12. Relating productivity to visibility and lighting

    Energy Technology Data Exchange (ETDEWEB)

    Clear, R.; Berman, S.

    1982-01-01

    The problem of determining the appropriate light levels for visual tasks is a cost-benefit problem. Existing light level recommendations seriously underweight the importance of economic factors. Furthermore, the relative importance of the visibility factors in determining the optimal light levels appears inconsistent with the importance of these factors in determining visibility and visual performance. It is shown that calculations based on acuities give a lower limit of 100 to 200 lux for cost-effective light levels for office tasks. Upper limits are calculated from correlations of task performance to visibility levels. Visibility levels become progressively insensitive to luminance as luminance increases. Average power densities above 100 watts/m/sup 2/ are cost-effective only when visibility is very low. However, there is a 3-to-10 times larger increase in benefits from improving contrast or contrast sensitivity than from using more than 10 watts/m/sup 2/. Contrast or contrast sensitivity can be improved by using forms with larger print, using xerographic copy instead of carbon or mimeo, making sure office workers have the right eyeglasses, or even by transferring workers with visual problems to less visually demanding tasks. Once these changes are made it is no longer cost-effective to use more than 10 watts/m/sup 2/. This conclusion raises serious questions about recommendations that lead to greater than about 10 watts/m/sup 2/ of installed lighting for general office work.

  13. Detecting series periodicity with horizontal visibility graphs

    CERN Document Server

    Núñez, Angel M; Valero, Eusebio; Gómez, Jose Patricio; Luque, Bartolo

    2011-01-01

    The horizontal visibility algorithm has been recently introduced as a mapping between time series and networks. The challenge lies in characterizing the structure of time series (and the processes that generated those series) using the powerful tools of graph theory. Recent works have shown that the visibility graphs inherit several degrees of correlations from their associated series, and therefore such graph theoretical characterization is in principle possible. However, both the mathematical grounding of this promising theory and its applications are on its infancy. Following this line, here we address the question of detecting hidden periodicity in series polluted with a certain amount of noise. We first put forward some generic properties of horizontal visibility graphs which allow us to define a (graph theoretical) noise reduction filter. Accordingly, we evaluate its performance for the task of calculating the period of noisy periodic signals, and compare our results with standard time domain (autocorre...

  14. Digital/Commercial (In)visibility

    DEFF Research Database (Denmark)

    Leander, Anna

    2016-01-01

    an argument demonstrating specifically how digital and commercial logics characterize the aesthetic, circulatory, and infrastructuring practices re-producing the regime of (in)visibility. It shows that digital/commercial logics are at the heart of the combinatorial marketing of multiple, contradictory images......This article explores one aspect of digital politics, the politics of videos and more spe- cifically of DAESH recruitment videos. It proposes a practice theoretical approach to the politics of DAESH recruitment videos focused on the re-production of regimes of (in)visibility. The article develops...... on the internet. The theoretical and political cost of overlooking these digital and commercial characteristics of DAESH visibility practices are high. It perpetuates misconceptions of how the videos work and what their politics are and it reinforces the digital Orientalism/Occidentalism in which...

  15. The Disappearing Audience and Reflexive Visibility

    Directory of Open Access Journals (Sweden)

    Katerina Girginova

    2016-08-01

    Full Text Available Contrary to popular opinion and some academic writing that celebrates the renewed visibility of new media audiences, this essay argues that they are increasingly going into retreat. To understand how new media audiences “disappear” from view of one another, I borrow from Brighenti’s typology of visibility and develop the idea of “reflexive visibility.” The latter describes the ability to socially orient ourselves in a digital environment through the textual and contextual cues of others—an activity that is of utmost importance not only to researchers wishing to “see” various audiences but also for audiences writ large, wishing to know themselves.

  16. Visible imaging of edge turbulence in NSTX

    Energy Technology Data Exchange (ETDEWEB)

    S. Zweben; R. Maqueda; K. Hill; D. Johnson; S. Kaye; H. Kugel; F. Levinton; R. Maingi; L. Roquemore; S. Sabbagh; G. Wurden

    2000-06-21

    Edge plasma turbulence in tokamaks and stellarators is believed to cause the radial heat and particle flux across the separatrix and into the scrape-off-layers of these devices. This paper describes initial measurements of 2-D space-time structure of the edge density turbulence made using a visible imaging diagnostic in the National Spherical Torus Experiment (NSTX). The structure of the edge turbulence is most clearly visible using a method of ''gas puff imaging'' to locally illuminate the edge density turbulence.

  17. Visible imaging of edge turbulence in NSTX

    Energy Technology Data Exchange (ETDEWEB)

    S. Zweben; R. Maqueda; K. Hill; D. Johnson; et al

    2000-06-13

    Edge plasma turbulence in tokamaks and stellarators is believed to cause the radical heat and particle flux across the separatrix and into the scrape-off-layers of these devices. This paper describes initial measurements of 2-D space-time structure of the edge density turbulence made using a visible imaging diagnostic in the National Spherical Torus Experiment (NSTX). The structure of the edge turbulence is most clearly visible using a method of gas puff imaging to locally illuminate the edge density turbulence.

  18. Query Load Balancing For Visible Object Extraction

    DEFF Research Database (Denmark)

    Bukauskas, Linas; Bøhlen, Michael Hanspeter

    2004-01-01

    Interactive visual data explorations impose rigid real-time requirements on the extraction of visible objects. Often these requirements are met by deploying powerful hardware that maintains the entire data set in huge main memory structures. In this paper we propose an approach that retrieves...... objects along the path. The visible objects are retrieved incrementally, and it is possible to precisely control the query load and the number of retrieved objects. The minimal distance path method issues frequent queries and retrieves the lowest possible number of objects at each query point. The end...

  19. A feeling of being (in)visible

    DEFF Research Database (Denmark)

    Damsgaard, Janne Brammer; Bastrup, Lene; Norlyk, Annelise

    Abstract PhD Day 2015 The illness trajectory of spine fusion patients. A feeling of being (in)visible Background Research shows that being a back patient is associated with great personal cost, and that back patients who undergo so-called spine fusion often experience particularly long and uncoor......Abstract PhD Day 2015 The illness trajectory of spine fusion patients. A feeling of being (in)visible Background Research shows that being a back patient is associated with great personal cost, and that back patients who undergo so-called spine fusion often experience particularly long...

  20. Visible Effects of Invisible Hidden Valley Radiation

    CERN Document Server

    Carloni, Lisa

    2010-01-01

    Assuming there is a new gauge group in a Hidden Valley, and a new type of radiation, can we observe it through its effect on the kinematic distributions of recoiling visible particles? Specifically, what are the collider signatures of radiation in a hidden sector? We address these questions using a generic SU(N)-like Hidden Valley model that we implement in Pythia. We find that in both the e+e- and the LHC cases the kinematic distributions of the visible particles can be significantly affected by the valley radiation. Without a proper understanding of such effects, inferred masses of "communicators" and of invisible particles can be substantially off.

  1. 60 years of UK visibility measurements: impact of meteorology and atmospheric pollutants on visibility

    Science.gov (United States)

    Singh, Ajit; Bloss, William J.; Pope, Francis D.

    2017-02-01

    Reduced visibility is an indicator of poor air quality. Moreover, degradation in visibility can be hazardous to human safety; for example, low visibility can lead to road, rail, sea and air accidents. In this paper, we explore the combined influence of atmospheric aerosol particle and gas characteristics, and meteorology, on long-term visibility. We use visibility data from eight meteorological stations, situated in the UK, which have been running since the 1950s. The site locations include urban, rural and marine environments. Most stations show a long-term trend of increasing visibility, which is indicative of reductions in air pollution, especially in urban areas. Additionally, the visibility at all sites shows a very clear dependence on relative humidity, indicating the importance of aerosol hygroscopicity on the ability of aerosol particles to scatter radiation. The dependence of visibility on other meteorological parameters, such as wind speed and wind direction, is also investigated. Most stations show long-term increases in temperature which can be ascribed to climate change, land-use changes (e.g. urban heat island effects) or a combination of both; the observed effect is greatest in urban areas. The impact of this temperature change upon local relative humidity is discussed. To explain the long-term visibility trends and their dependence on meteorological conditions, the measured data were fitted to a newly developed light-extinction model to generate predictions of historic aerosol and gas scattering and absorbing properties. In general, an excellent fit was achieved between measured and modelled visibility for all eight sites. The model incorporates parameterizations of aerosol hygroscopicity, particle concentration, particle scattering, and particle and gas absorption. This new model should be applicable and is easily transferrable to other data sets worldwide. Hence, historical visibility data can be used to assess trends in aerosol particle

  2. Making Intercultural Language Learning Visible and Assessable

    Science.gov (United States)

    Moloney, Robyn; Harbon, Lesley

    2010-01-01

    While languages education (Liddicoat, 2002) is being transformed by intercultural language learning theory, there is little illustration of either how students are achieving intercultural learning or how to assess it. This article reports on a study of high school language students in Sydney, Australia. Its findings make visible student…

  3. Psychophysical thresholds of face visibility during infancy

    DEFF Research Database (Denmark)

    Gelskov, Sofie; Kouider, Sid

    2010-01-01

    . By contrast, 15 month-olds not only revealed adult-like thresholds, but also improved their performance through memory-based strategies. Our results imply that the development of face visibility follows a non-linear course and is determined by a radical improvement occurring between 10 and 15 months....

  4. Visible Counterterrorism Measures in Urban Spaces

    DEFF Research Database (Denmark)

    Dalgaard-Nielsen, Anja; Laisen, Jesper; Wandorf, Charlotte

    2014-01-01

    factors impacting positively or negatively on the feelings of safety of Danish citizens, when being in a crowded place. Surprisingly, the response to security measures like fences, cameras, and uniformed guards was positive. More visible security apparently reinforced feelings of safety. This article...

  5. Macroscopic invisibility cloaking of visible light

    DEFF Research Database (Denmark)

    Chen, Xianzhong; Luo, Y.; Zhang, Jingjing

    2011-01-01

    to a few wavelengths. Here, we report the first realization of a macroscopic volumetric invisibility cloak constructed from natural birefringent crystals. The cloak operates at visible frequencies and is capable of hiding, for a specific light polarization, three-dimensional objects of the scale...

  6. Full duplex communication using visible light

    CERN Document Server

    Yang, Yongchao; Li, Yuanhang; Gao, Xumin; Yuan, Jialei; Zhu, Hongbo; Wang, Yongjin

    2016-01-01

    In this work, we propose, fabricate and characterize a full duplex communication system using visible light on a single chip. Both the suspended p-n junction InGaN/GaN multiple quantum well (MQW) devices and the suspended waveguides are obtained on a GaN-on-silicon platform by wafer-level processing. Two suspended p-n junction InGaN/GaN MQW devices that can both emit and detect light simultaneously are connected using suspended waveguides to form an in-plane visible light communication (VLC) system. The light that is emitted from one suspended p-n junction InGaN/GaN MQW device can induce a current in the device located at the other end of the waveguide via in-plane light coupling, thus leading to full duplex communication using visible light. This proof-of-concept in-plane VLC system paves the way towards the implementation of a full duplex communications system operating at the same frequency using visible light on a single chip.

  7. Making Intercultural Language Learning Visible and Assessable

    Science.gov (United States)

    Moloney, Robyn; Harbon, Lesley

    2010-01-01

    While languages education (Liddicoat, 2002) is being transformed by intercultural language learning theory, there is little illustration of either how students are achieving intercultural learning or how to assess it. This article reports on a study of high school language students in Sydney, Australia. Its findings make visible student…

  8. Efficient Geometric Sound Propagation Using Visibility Culling

    Science.gov (United States)

    Chandak, Anish

    2011-07-01

    Simulating propagation of sound can improve the sense of realism in interactive applications such as video games and can lead to better designs in engineering applications such as architectural acoustics. In this thesis, we present geometric sound propagation techniques which are faster than prior methods and map well to upcoming parallel multi-core CPUs. We model specular reflections by using the image-source method and model finite-edge diffraction by using the well-known Biot-Tolstoy-Medwin (BTM) model. We accelerate the computation of specular reflections by applying novel visibility algorithms, FastV and AD-Frustum, which compute visibility from a point. We accelerate finite-edge diffraction modeling by applying a novel visibility algorithm which computes visibility from a region. Our visibility algorithms are based on frustum tracing and exploit recent advances in fast ray-hierarchy intersections, data-parallel computations, and scalable, multi-core algorithms. The AD-Frustum algorithm adapts its computation to the scene complexity and allows small errors in computing specular reflection paths for higher computational efficiency. FastV and our visibility algorithm from a region are general, object-space, conservative visibility algorithms that together significantly reduce the number of image sources compared to other techniques while preserving the same accuracy. Our geometric propagation algorithms are an order of magnitude faster than prior approaches for modeling specular reflections and two to ten times faster for modeling finite-edge diffraction. Our algorithms are interactive, scale almost linearly on multi-core CPUs, and can handle large, complex, and dynamic scenes. We also compare the accuracy of our sound propagation algorithms with other methods. Once sound propagation is performed, it is desirable to listen to the propagated sound in interactive and engineering applications. We can generate smooth, artifact-free output audio signals by applying

  9. Visible Geology - Interactive online geologic block modelling

    Science.gov (United States)

    Cockett, R.

    2012-12-01

    Geology is a highly visual science, and many disciplines require spatial awareness and manipulation. For example, interpreting cross-sections, geologic maps, or plotting data on a stereonet all require various levels of spatial abilities. These skills are often not focused on in undergraduate geoscience curricula and many students struggle with spatial relations, manipulations, and penetrative abilities (e.g. Titus & Horsman, 2009). A newly developed program, Visible Geology, allows for students to be introduced to many geologic concepts and spatial skills in a virtual environment. Visible Geology is a web-based, three-dimensional environment where students can create and interrogate their own geologic block models. The program begins with a blank model, users then add geologic beds (with custom thickness and color) and can add geologic deformation events like tilting, folding, and faulting. Additionally, simple intrusive dikes can be modelled, as well as unconformities. Students can also explore the interaction of geology with topography by drawing elevation contours to produce their own topographic models. Students can not only spatially manipulate their model, but can create cross-sections and boreholes to practice their visual penetrative abilities. Visible Geology is easy to access and use, with no downloads required, so it can be incorporated into current, paper-based, lab activities. Sample learning activities are being developed that target introductory and structural geology curricula with learning objectives such as relative geologic history, fault characterization, apparent dip and thickness, interference folding, and stereonet interpretation. Visible Geology provides a richly interactive, and immersive environment for students to explore geologic concepts and practice their spatial skills.; Screenshot of Visible Geology showing folding and faulting interactions on a ridge topography.

  10. Research on Chinese Visible Human Project

    Institute of Scientific and Technical Information of China (English)

    ZhangShaoxiang

    2003-01-01

    Visible Human Project (VHP)” was initiated by US National Library of Medicine in 1989, and in August 1991, the library signed a contract with Health Science Center of the University of Col-orado to formally carry out the project. According-ly, research team at the University of Colorado col-lected a structural data set of human body after obtaining successive sectiona/ images. A digital image data set of a complete human male cadaver was acquired and made available for public use in November 1994, which aroused worldwide enthu-siasm in this field, and remarkable social and eco-nomic benefit has been gained. Thereafter, some countries initiated their visible human project one after another. Korea started 5-year“Visible Kore-an Human (VKH)” project (Mar. 2000--Feb.2005) in 2000, and the first data set derived from apatient with cerebroma was acquired in 2001. Chi-na began its project in 1999. The first data set of Chinese visible human was obtained at The Third Military Medical University in October 2002. Before that, by utilizing data made public by US VHP, Chi-nese scientists in informatics had exerted them-selves on preliminary work to pave the way for fur-ther achievement. Now that VHP research is such a promising scientific field to meet the need of digital era and will be increasingly common in many areas related with structure and function of human body,the deployment of Chinese Visible Human Project(CVHP) is of great strategic significance with re-gard to science and technology.

  11. Comparison of Visibility Measurements over Horizontal Path by Micro-pulsed Lidar and Visibility Meter

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    As a powerful tool to scan the atmosphere, the 1idar can derive visibility values by directly collecting the backscattering laser light from the atmosphere. Simultaneous measurements of atmospheric visibility by Micro-pulsed lidar (MPL) and a commercial visibility meter (VM) NQ-1 have been performed to evaluate the feasibility of the MPL system designed by the Ocean Remote Sensing Laboratory (ORSL) of the Ocean University of China (OUC) from October 21 2005 to November 21 2005 in the Shilaoren Sightseeing Garden on the Qingdao coast. All the 880 data samples obtained by the two instruments have high correlation coefficients (up to 0.86), which indicates it is feasible to utilize MPL to measure atmospheric visibility.

  12. Titanium dioxide visible light photocatalysis: surface association enables photocatalysis with visible light irradiation.

    Science.gov (United States)

    Pitre, Spencer P; Yoon, Tehshik P; Scaiano, Juan C

    2017-04-13

    Titanium dioxide (TiO2) is a widely employed and inexpensive photocatalyst, but its use in organic synthesis has been limited by the short-wavelength ultraviolet irradiation typically used. We have discovered that TiO2 particles efficiently mediate photocatalytic radical cation Diels-Alder cycloadditions using a simple visible light source, enabled by the formation of a visible light absorbing complex of the substrate on the semiconductor surface.

  13. Severe sepsis secondary to emphysematous cystitis

    African Journals Online (AJOL)

    M.M. Gargouri

    We present the case of a patient with EC who presented with severe sepsis of unknown origin. He ... Peer review under responsibility of Pan African Urological Surgeons' ... nantly on the left side, minimal dysuria and fever for the previous 7.

  14. Visibly ethnically different families in Denmark & Sweden

    DEFF Research Database (Denmark)

    Singla, Rashmi

    . Alongside colorblindness, limited/ missing racialisation discussions, the visible bodies of spouses, children in the mixed families and the transnational adoptees are made salient in their everyday lives in interactions with the white majority population through experiences as gaze, curious questions......This paper foregounds visibly ethnically different families (Phoenix, 2011) in Denmark. These comprise both.families with parents from two different countries (India and Denmark) and families with transnational adoptees (South Korea). The former are barely scientifically explored due...... to the dominant colorblindness discourse, while later comprise a heated topic challenging poor (global south) adoptee meeting a loving Danish family’ discourse. How do these family members narrate their experiences of societal encounter is the research question, which is answered through two qualitative interview...

  15. Visibility graphlet approach to chaotic time series

    Energy Technology Data Exchange (ETDEWEB)

    Mutua, Stephen [Business School, University of Shanghai for Science and Technology, Shanghai 200093 (China); Computer Science Department, Masinde Muliro University of Science and Technology, P.O. Box 190-50100, Kakamega (Kenya); Gu, Changgui, E-mail: gu-changgui@163.com, E-mail: hjyang@ustc.edu.cn; Yang, Huijie, E-mail: gu-changgui@163.com, E-mail: hjyang@ustc.edu.cn [Business School, University of Shanghai for Science and Technology, Shanghai 200093 (China)

    2016-05-15

    Many novel methods have been proposed for mapping time series into complex networks. Although some dynamical behaviors can be effectively captured by existing approaches, the preservation and tracking of the temporal behaviors of a chaotic system remains an open problem. In this work, we extended the visibility graphlet approach to investigate both discrete and continuous chaotic time series. We applied visibility graphlets to capture the reconstructed local states, so that each is treated as a node and tracked downstream to create a temporal chain link. Our empirical findings show that the approach accurately captures the dynamical properties of chaotic systems. Networks constructed from periodic dynamic phases all converge to regular networks and to unique network structures for each model in the chaotic zones. Furthermore, our results show that the characterization of chaotic and non-chaotic zones in the Lorenz system corresponds to the maximal Lyapunov exponent, thus providing a simple and straightforward way to analyze chaotic systems.

  16. High efficiency dielectric metasurfaces at visible wavelengths

    CERN Document Server

    Devlin, Robert C; Chen, Wei-Ting; Oh, Jaewon; Capasso, Federico

    2016-01-01

    Metasurfaces are planar optical elements that hold promise for overcoming the limitations of refractive and conventional diffractive optics1-3. Dielectric metasurfaces demonstrated thus far4-10 are limited to transparency windows at infrared wavelengths because of significant optical absorption and loss at visible wavelengths. It is critical that new materials and fabrication techniques be developed for dielectric metasurfaces at visible wavelengths to enable applications such as three-dimensional displays, wearable optics and planar optical systems11. Here, we demonstrate high performance titanium dioxide dielectric metasurfaces in the form of holograms for red, green and blue wavelengths with record absolute efficiency (>78%). We use atomic layer deposition of amorphous titanium dioxide that exhibits low surface roughness of 0.738 nm and ideal optical properties. To fabricate the metasurfaces we use a lift-off-like process that allows us to produce highly anisotropic nanofins with shape birefringence. This ...

  17. Visibility graphlet approach to chaotic time series.

    Science.gov (United States)

    Mutua, Stephen; Gu, Changgui; Yang, Huijie

    2016-05-01

    Many novel methods have been proposed for mapping time series into complex networks. Although some dynamical behaviors can be effectively captured by existing approaches, the preservation and tracking of the temporal behaviors of a chaotic system remains an open problem. In this work, we extended the visibility graphlet approach to investigate both discrete and continuous chaotic time series. We applied visibility graphlets to capture the reconstructed local states, so that each is treated as a node and tracked downstream to create a temporal chain link. Our empirical findings show that the approach accurately captures the dynamical properties of chaotic systems. Networks constructed from periodic dynamic phases all converge to regular networks and to unique network structures for each model in the chaotic zones. Furthermore, our results show that the characterization of chaotic and non-chaotic zones in the Lorenz system corresponds to the maximal Lyapunov exponent, thus providing a simple and straightforward way to analyze chaotic systems.

  18. Masking mediated print defect visibility predictor

    Science.gov (United States)

    Jing, Xiaochen; Nachlieli, Hila; Shaked, Doron; Shiffman, Smadar; Allebach, Jan P.

    2012-01-01

    Banding is a well-known artifact produced by printing systems. It usually appears as lines perpendicular to the process direction of the print. Therefore, banding is an important print quality issue which has been analyzed and assessed by many researchers. However, little literature has focused on the study of the masking effect of content for this kind of print quality issue. Compared with other image and print quality research, our work is focused on the print quality of typical documents printed on a digital commercial printing press. In this paper, we propose a Masking Mediated Print Defect Visibility Predictor (MMPDVP) to predict the visibility of defects in the presence of customer content. The parameters of the algorithm are trained from ground-truth images that have been marked by subjects. The MMPDVP could help the press operator decide whether the print quality is acceptable for specific customer requirements. Ultimately, this model can be used to optimize the print-shop workflow.

  19. New polydiacetylenes with visible chromophoric side groups

    Energy Technology Data Exchange (ETDEWEB)

    Foley, J.L.; Shivshankar, V.; Sandman, D.J.

    1998-07-01

    In the interest of obtaining crystalline polydiacetylene with absorption at longer wavelengths, new derivatives of 2,4-hexadiyne with planar, visible absorbing aromatic chromophores have been designed, synthesized, and thermally polymerized. The resulting polymers have a red shifted maximum with absorption extending to the infrared. Their Raman spectra show the usual polydiacetylene ene-yne structure, and X-ray powder diffraction reveals that the new polymers are crystalline.

  20. Service Visibility Across Lines Of Business

    Directory of Open Access Journals (Sweden)

    Karen L. Harper

    2011-11-01

    Full Text Available This paper introduces the use of service science to maximize profitability by providing service transparency across lines of business in a financial operating environment. The concept of a live collector that runs in the cloud is presented. The collector gives information visibility, context mediation, and presentation facilities on a dynamic basis by employing the principles of cloud computing. The subject of cloud computing is introduced in the paper.

  1. Promoting visibility for the nurse practitioner role.

    Science.gov (United States)

    Edmunds, M W

    1988-03-01

    In promoting greater public awareness of nurse practitioners' contributions to health care, two major strategies may be used. Creating broad-based visibility through the use of the basic media and marketing strategies, and utilizing individual client encounters to educate clients about the NP role are both effective. NPs should assume the initiative in seeking out opportunities to create positive images for the nurse practitioner.

  2. Transformational leadership: visibility, accessibility, and communication.

    Science.gov (United States)

    Clavelle, Joanne T

    2012-01-01

    The chief nursing officer of a Magnet® organization is a dynamic, transformational leader who develops and communicates a strong vision for nursing excellence and creates a foundation for exemplary nursing practice and excellent patient care. Transformational leadership is a core component of the Magnet Model®. The 3rd subcomponent--visibility, accessibility, and communication--is the focus of this article.

  3. Visible-wavelength semiconductor lasers and arrays

    Science.gov (United States)

    Schneider, Jr., Richard P.; Crawford, Mary H.

    1996-01-01

    A visible semiconductor laser. The visible semiconductor laser includes an InAlGaP active region surrounded by one or more AlGaAs layers on each side, with carbon as the sole p-type dopant. Embodiments of the invention are provided as vertical-cavity surface-emitting lasers (VCSELs) and as edge-emitting lasers (EELs). One or more transition layers comprised of a substantially indium-free semiconductor alloy such as AlAsP, AlGaAsP, or the like may be provided between the InAlGaP active region and the AlGaAS DBR mirrors or confinement layers to improve carrier injection and device efficiency by reducing any band offsets. Visible VCSEL devices fabricated according to the invention with a one-wavelength-thick (1.lambda.) optical cavity operate continuous-wave (cw) with lasing output powers up to 8 mW, and a peak power conversion efficiency of up to 11%.

  4. Photodetector Characteristics in Visible Light Communication

    KAUST Repository

    Ho, Kang-Ting

    2016-04-01

    Typically, in the semiconductor industry pn heterojunctions have been used as either light-emitting diodes (LED) or photodiodes by applying forward current bias or reverse voltage bias, respectively. However, since both devices use the same structure, the light emitting and detecting properties could be combine in one single device, namely LED-based photodetector. Therefore, by integrating LED-based photodetectors as either transmitter or receiver, optical wireless communication could be easily implemented for bidirectional visible light communication networks at low-cost. Therefore, this dissertation focus on the investigation of the photodetection characteristics of InGaN LED-based photodetectors for visible light communication in the blue region. In this regard, we obtain external quantum efficiency of 10 % and photoresponse rise time of 71 μs at 405-nm illumination, revealing high-performance photodetection characteristics. Furthermore, we use orthogonal frequency division multiplexing quadrature amplitude modulation codification scheme to enlarge the operational bandwidth. Consequently, the transmission rate of the communication is efficiently enhanced up to 420 Mbit/s in visible light communication.

  5. On spectropolarimetric measurements with visible lines

    CERN Document Server

    Iniesta, J C del Toro; Rubio, L R Bellot

    2010-01-01

    The ability of new instruments for providing accurate inferences of vector magnetic fields and line-of-sight velocities of the solar plasma depends a great deal on the sensitivity to these physical quantities of the spectral lines chosen to be measured. Recently, doubts have been raised about visible Stokes profiles to provide a clear distinction between weak fields and strong ones filling a small fraction of the observed area. The goal of this paper is to give qualitative and quantitative arguments that help in settling the debate since several instruments that employ visible lines are either operating or planned for the near future. The sensitivity of the Stokes profiles is calculated through the response functions (e.g. Ruiz Cobo & Del Toro Iniesta, 1994). Both theoretical and empirical evidences are gathered in favor of the reliability of visible Stokes profiles. The response functions are used as well for estimating the uncertainties in the physical quantities due to noise in the observations. A usef...

  6. Visibility assesment using remote sensing data

    Science.gov (United States)

    Toanca, Florica; Vasilescu, Jeni; Nicolae, Doina; Stefan, Sabina

    2016-04-01

    Severe weather events like fog have a high impact on all kinds of traffic operations. During the last decade was proven the capability of remote sensing equipments to detect fog cases in terms of duration, occurrence and dissipation. Therefore, in this study the data from Väïsälä CL31 ceilometer and Raman Depolarization Lidar installed at Magurele, Romania (44.35 N, 26.03 E) were used. The backscatter coefficient from Ceilometer and extinction coefficient and different lidar ratios (LR) values from Lidar were used in order to determine horizontal visibility during the fog events in Magurele area. Ceilometer backscatter coefficient profiles are obtained with a time resolution of 16 s and up to 7.5 km altitude. . A neural network algorithm was used to calculate the lidar ratio values for different aerosol types and also for different relative humidity. Thus, for continental aerosol the LR value is 58srad, for continental polluted is 60srad and for smoke LR is 55srad. The average visibility computed for radiation fog , dominant type (57 cases) occurring in Magurele, during 2012-2014 was 50m. An important result is that the dependence of horizontal visibility for radiation fog at Magurele on LR is insignificant. This means that radiation, meteorological and geographical factors influence fog generation more much than aerosol type.

  7. Runway hazard detection in poor visibility conditions

    Science.gov (United States)

    Jiang, Bo; Rahman, Zia-ur

    2012-01-01

    More recently, research on enhancing the situational awareness of pilots, especially in poor visibility flight conditions, gains more and more interests. Since pilots may not be able to spot the runway clearly in poor visibility conditions, such as fog, smoke, haze or dim lighting conditions, aviation landing problem can occur due to the (unexpected) presence of objects on the runway. Complicated and trivial instruments, switches, bottoms, plus sudden happenings are enough for the pilots to take care of during landing approach. Therefore, an automatic hazard detection approach that combines non-linear Multi-scale Retinex (MSR) image enhancement, edge detection with basic edge pattern analysis, and image analysis is investigated. The effect of applying the enhancement method is to make the image of the runway almost independent from the poor atmospheric conditions. The following smart edge detection process extracts edge information, which can also reduce the storing space, the comparison and retrieval time, and the effect of sensor noise. After analyzing the features existing in the edge differences occurring in the runway area by digital image processing techniques, the existing potential hazard will be localized and labeled. Experimental results show that the proposed approach is effective in runway hazard detection in poor visibility conditions.

  8. Atmospheric visibility estimation and image contrast calibration

    Science.gov (United States)

    Hermansson, Patrik; Edstam, Klas

    2016-10-01

    A method, referred to as contrast calibration, has been developed for transforming digital color photos of outdoor scenes from the atmospheric conditions, illumination and visibility, prevailing at the time of capturing the image to a corresponding image for other atmospheric conditions. A photo captured on a hazy day can, for instance, be converted to resemble a photo of the same scene for good visibility conditions. Converting digital color images to specified lightning and transmission conditions is useful for image based assessment of signature suppression solutions. The method uses "calibration objects" which are photographed at about the same time as the scene of interest. The calibration objects, which (indirectly) provide information on visibility and lightning conditions, consist of two flat boards, painted in different grayscale colors, and a commercial, neutral gray, reference card. Atmospheric extinction coefficient and sky intensity can be determined, in three wavelength bands, from image pixel values on the calibration objects and using this information the image can be converted to other atmospheric conditions. The image is transformed in contrast and color. For illustration, contrast calibration is applied to sample images of a scene acquired at different times. It is shown that contrast calibration of the images to the same reference values of extinction coefficient and sky intensity results in images that are more alike than the original images. It is also exemplified how images can be transformed to various other atmospheric weather conditions. Limitations of the method are discussed and possibilities for further development are suggested.

  9. Mode visibilities in rapidly rotating stars

    Science.gov (United States)

    Reese, D. R.; Prat, V.; Barban, C.; van 't Veer-Menneret, C.; MacGregor, K. B.

    2013-02-01

    Context. Mode identification is a crucial step to comparing observed frequencies with theoretical ones. However, it has proven to be particularly difficult in rapidly rotating stars. An important reason for this is the lack of simple frequency patterns such as those present in solar-type pulsators. This problem is further aggravated in δ Scuti stars by their particularly rich frequency spectra. Aims: As a first step to obtaining further observational constraints towards mode identification in rapid rotators, we aim to accurately calculate mode visibilities and amplitude ratios while fully taking into account the effects of rotation. Methods: We derive the relevant equations for calculating mode visibilities in different photometric bands while fully taking into account the geometric distortion from both the centrifugal deformation and the pulsation modes, the variations in effective gravity, and an approximate treatment of the temperature variations, given the adiabatic nature of the pulsation modes. These equations are then applied to 2D oscillation modes, calculated using the TOP code (Two-dimension Oscillation Program), in fully distorted 2D models based on the self-consistent field (SCF) method. The specific intensities come from a grid of Kurucz atmospheres, thereby taking into account limb and gravity darkening. Results: We obtain mode visibilities and amplitude ratios for 2 M⊙ models with rotation rates ranging from 0 to 80% of the critical rotation rate. Based on these calculations, we confirm a number of results from earlier studies, such as the increased visibility of numerous chaotic modes at sufficient rotation rates, the simpler frequency spectra with dominant island modes for pole-on configurations, or the dependence of amplitude ratios on inclination and azimuthal order in rotating stars. In addition, we explain how the geometric shape of the star leads to a smaller contrast between pole-on and equator-on visibilities of equatorially

  10. Visible Light Responsive Catalyst for Air Water Purification Project

    Science.gov (United States)

    Wheeler, Raymond M.

    2014-01-01

    Investigate and develop viable approaches to render the normally UV-activated TIO2 catalyst visible light responsive (VLR) and achieve high and sustaining catalytic activity under the visible region of the solar spectrum.

  11. The Visible Humans | NIH MedlinePlus the Magazine

    Science.gov (United States)

    ... of this page please turn JavaScript on. Feature: The Visible Humans The Visible Humans Past Issues / Fall 2014 Table of Contents Twenty years ago, the National Library of Medicine (NLM) did something that ...

  12. Efficient visibility-driven medical image visualisation via adaptive binned visibility histogram.

    Science.gov (United States)

    Jung, Younhyun; Kim, Jinman; Kumar, Ashnil; Feng, David Dagan; Fulham, Michael

    2016-07-01

    'Visibility' is a fundamental optical property that represents the observable, by users, proportion of the voxels in a volume during interactive volume rendering. The manipulation of this 'visibility' improves the volume rendering processes; for instance by ensuring the visibility of regions of interest (ROIs) or by guiding the identification of an optimal rendering view-point. The construction of visibility histograms (VHs), which represent the distribution of all the visibility of all voxels in the rendered volume, enables users to explore the volume with real-time feedback about occlusion patterns among spatially related structures during volume rendering manipulations. Volume rendered medical images have been a primary beneficiary of VH given the need to ensure that specific ROIs are visible relative to the surrounding structures, e.g. the visualisation of tumours that may otherwise be occluded by neighbouring structures. VH construction and its subsequent manipulations, however, are computationally expensive due to the histogram binning of the visibilities. This limits the real-time application of VH to medical images that have large intensity ranges and volume dimensions and require a large number of histogram bins. In this study, we introduce an efficient adaptive binned visibility histogram (AB-VH) in which a smaller number of histogram bins are used to represent the visibility distribution of the full VH. We adaptively bin medical images by using a cluster analysis algorithm that groups the voxels according to their intensity similarities into a smaller subset of bins while preserving the distribution of the intensity range of the original images. We increase efficiency by exploiting the parallel computation and multiple render targets (MRT) extension of the modern graphical processing units (GPUs) and this enables efficient computation of the histogram. We show the application of our method to single-modality computed tomography (CT), magnetic resonance

  13. Study on calculation model of road lighting visibility

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Visibility is an evaluation index for road lighting, which comprehensively influences the vision reliability of drivers and is a key factor for road lighting safety and energy saving. This paper introduces the concept of road lighting visibility and its influencing factors. It also explains the small target visibility calculation model for road lighting design, and describes the significance of establishing urban road lighting visibility standards from a point of view of visual function and visual comfort of drivers.

  14. A feeling of being (in)visible

    DEFF Research Database (Denmark)

    Damsgaard, Janne Brammer; Bastrup, Lene; Norlyk, Annelise

    contact with the healthcare system and healthcare professionals are often dismissed as irrelevant. It is also evident that spine fusion patients are denied the opportunity to verbalise what it feels like to, for example, be ”a person in constant pain” or someone who ”holds back” to avoid being......Abstract PhD Day 2015 The illness trajectory of spine fusion patients. A feeling of being (in)visible Background Research shows that being a back patient is associated with great personal cost, and that back patients who undergo so-called spine fusion often experience particularly long...

  15. Dynamical Analyses Using Visibilities in Financial Markets

    Science.gov (United States)

    Min, Seungsik; Lim, Kyuseong; Chang, Ki-Ho; Park, Il-Hwan; Kim, Kyungsik

    2016-04-01

    In this paper, the network metrics are studied in a time series of the KOSPI and the KOSDAQ indices converting by the visibility graph algorithm. The degree distributions for the KOSPI and the KOSDAQ are proportional to a power law rather than the Poisson distribution. Since we mainly simulate and analyze the network metrics from the nodes and its links, our result cannot be found unambiguously to have universal and characteristic properties of statistical quantities via financial networks. Particularly, these topological properties may improve by implementing the statistical method and its technique from altered data of financial networks.

  16. New stratospheric UV/visible radiance measurements

    Directory of Open Access Journals (Sweden)

    F. J. Marceau

    Full Text Available A stratospheric balloon was launched on 12 October 1986 from the "CNES" base at Aire sur l'Adour (France to record twilight radiance in the stratosphere. The near-UV and visible radiances were continuously monitored by a photometer during sunrise. Some observations are presented for different viewing azimuthal planes and viewing elevation angles. They show the influence of aerosols layers and clouds which can be also seen on related photographs. The results as a whole may be used for testing some radiative models, especially for twilight conditions.

  17. Speckle visibility spectroscopy and variable granular fluidization.

    Science.gov (United States)

    Dixon, P K; Durian, D J

    2003-05-09

    We introduce a dynamic light scattering technique capable of resolving motion that changes systematically, and rapidly, with time. It is based on the visibility of a speckle pattern for a given exposure duration. Applying this to a vibrated layer of glass beads, we measure the granular temperature and its variation with phase in the oscillation cycle. We observe several transitions involving jammed states, where the grains are at rest during some portion of the cycle. We also observe a two-step decay of the temperature on approach to jamming.

  18. Spatial Domain Technique for Visible Watermarking

    Institute of Scientific and Technical Information of China (English)

    PeterAdjeiFordjour; 王朔中

    2003-01-01

    A new technique for embedding visible watermarks into a digital image is described in this paper, which uses statistical properties of each pixel and its immediate surrounding pixels in the host image, and also the statistical properties of the host image and that of the image to be embedded (watermark), as the pixels in the host image are replaced one by one by the pixels in the watermark image. The aim is to establish a relationship between pixels in the images that will make the embedded watermark robust and semitransparent, and to minimize errors caused by watermark addition and subtraction. Also, the original image can be completely reconstructed from the watermarked images.

  19. Bidirectional surface wave splitter at visible frequencies.

    Science.gov (United States)

    Gan, Qiaoqiang; Bartoli, Filbert J

    2010-12-15

    We experimentally demonstrate a metal-film bidirectional surface wave splitter for guiding light at two visible wavelengths in opposite directions. Two nanoscale gratings were patterned on opposite sides of a subwavelength slit. The metallic surface grating structures were tailored geometrically to have different plasmonic bandgaps, enabling each grating to guide light of one wavelength and prohibit propagation at the other wavelength. The locations of the bandgaps were experimentally confirmed by interferometric measurements. Based on these design principles, a green-red bidirectional surface wave splitter is demonstrated, and the observed optical properties are shown to agree with theoretical predictions.

  20. A Model of Visible QCD Axion

    CERN Document Server

    Fukuda, Hajime; Ibe, Masahiro; Yanagida, Tsutomu T

    2015-01-01

    We pursue a class of visible axion models where the axion mass is enhanced by strong dynamics in a mirrored copy of the Standard Model in the line of the idea put forward by Rubakov. In particular, we examine the consistency of the models with laboratory, astrophysical, and cosmological constraints. As a result, viable parameter regions are found, where the mass of the axion is of $O(100)$ MeV or above while the Peccei-Quinn breaking scale is at around $10^{3\\mbox{-}5}$ GeV.

  1. (In)visible Z' and dark matter

    CERN Document Server

    Dudas, E; Pokorski, S; Romagnoni, A

    2009-01-01

    We study the consequences of an extension of the standard model containing an invisible extra gauge group under which the SM particles are neutral. We show that effective operators, generated by loops of heavy chiral fermions charged undervboth gauge groups and connecting the new gauge sector to the Standard Model, can give rise to a viable dark matter candidate. Its annihilations produce clean visible signals through a gamma-ray line. This would be a smoking gun signature of such models observable by actual experiments.

  2. UV/Visible Telescope with Hubble Disposal

    Science.gov (United States)

    Benford, Dominic J.

    2013-01-01

    Submission Overview: Our primary objective is to convey a sense of the significant advances possible in astrophysics investigations for major Cosmic Origins COR program goals with a 2.4m telescope asset outfitted with one or more advanced UV visible instruments. Several compelling science objectives were identified based on community meetings these science objectives drove the conceptual design of instruments studied by the COR Program Office during July September 2012. This RFI submission encapsulates the results of that study, and suggests that a more detailed look into the instrument suite should be conducted to prove viability and affordability to support the demonstrated scientific value. This study was conducted in the context of a larger effort to consider the options available for a mission to dispose safely of Hubble hence, the overall architecture considered for the mission we studied for the 2.4m telescope asset included resource sharing. This mitigates combined cost and risk and provides naturally for a continued US leadership role in astrophysics with an advanced, general-purpose UV visible space telescope.

  3. Visibility Graph Based Time Series Analysis.

    Science.gov (United States)

    Stephen, Mutua; Gu, Changgui; Yang, Huijie

    2015-01-01

    Network based time series analysis has made considerable achievements in the recent years. By mapping mono/multivariate time series into networks, one can investigate both it's microscopic and macroscopic behaviors. However, most proposed approaches lead to the construction of static networks consequently providing limited information on evolutionary behaviors. In the present paper we propose a method called visibility graph based time series analysis, in which series segments are mapped to visibility graphs as being descriptions of the corresponding states and the successively occurring states are linked. This procedure converts a time series to a temporal network and at the same time a network of networks. Findings from empirical records for stock markets in USA (S&P500 and Nasdaq) and artificial series generated by means of fractional Gaussian motions show that the method can provide us rich information benefiting short-term and long-term predictions. Theoretically, we propose a method to investigate time series from the viewpoint of network of networks.

  4. Visible and occult microscopic lesions of endometriosis

    Directory of Open Access Journals (Sweden)

    Khaleque Newaz Khan

    2014-11-01

    Full Text Available Endometriosis is a multifactorial disease mostly affecting women of reproductive age and is associated with chronic pelvic pain and infertility. Even after 300 years, most of the literature claims that pathogenesis and/or pathophysiology of endometriosis is still elusive. Recurrence of pain and lesion continues to occur after effective medical or surgical therapies. Once generated within the pelvis due to retrograde entry of menstrual debris, peritoneal endometriotic lesions time-dependently change their color appearance resulting from certain biochemical change within lesions. A variable pattern of endometriotic lesions within the pelvis can be detected by laparoscopy as visible peritoneal endometriosis. It is generally believed that besides ovarian steroid hormones, the growth of endometriosis can be regulated by the innate immune system in the pelvic microenvironment by their interaction with endometrial cells and immune cells. Even with the careful eyes of an expert surgeon, we may sometimes miss detecting peritoneal lesion within the peritoneal cavity or deep into the peritoneum. In such a case, random collection of normal peritoneum may carry the possibility to identify some hidden endometriotic lesions by microscopy and these lesions can be named as occult (invisible microscopic endometriosis (OME. Here, we discuss the color appearance of peritoneal lesions and activity of these lesions by analysis of a panel of activity markers. Finally we discuss our recent findings on OME, their biological and clinical significance, and try to make a possible link in the origin between visible endometriosis and OME.

  5. Visibility Graph Based Time Series Analysis

    Science.gov (United States)

    Stephen, Mutua; Gu, Changgui; Yang, Huijie

    2015-01-01

    Network based time series analysis has made considerable achievements in the recent years. By mapping mono/multivariate time series into networks, one can investigate both it’s microscopic and macroscopic behaviors. However, most proposed approaches lead to the construction of static networks consequently providing limited information on evolutionary behaviors. In the present paper we propose a method called visibility graph based time series analysis, in which series segments are mapped to visibility graphs as being descriptions of the corresponding states and the successively occurring states are linked. This procedure converts a time series to a temporal network and at the same time a network of networks. Findings from empirical records for stock markets in USA (S&P500 and Nasdaq) and artificial series generated by means of fractional Gaussian motions show that the method can provide us rich information benefiting short-term and long-term predictions. Theoretically, we propose a method to investigate time series from the viewpoint of network of networks. PMID:26571115

  6. Robotic visible-light laser adaptive optics

    Science.gov (United States)

    Baranec, Christoph; Riddle, Reed; Law, Nicholas; Ramaprakash, A. N.; Tendulkar, Shriharsh; Bui, Khanh; Burse, Mahesh; Chordia, Pravin; Das, Hillol; Dekany, Richard; Kulkarni, Shrinivas; Punnadi, Sujit

    2013-12-01

    Robo-AO is the first autonomous laser adaptive optics system and science instrument operating on sky. With minimal human oversight, the system robotically executes large scale surveys, monitors long-term astrophysical dynamics and characterizes newly discovered transients, all at the visible diffraction limit. The adaptive optics setup time, from the end of the telescope slew to the beginning of an observation, is a mere ~50-60 s, enabling over 200 observations per night. The first of many envisioned systems has finished 58 nights of science observing at the Palomar Observatory 60-inch (1.5 m) telescope, with over 6,400 robotic observations executed thus far. The system will be augmented in late 2013 with a low-noise wide field infrared camera, which doubles as a tip-tilt sensor, to widen the spectral bandwidth of observations and increase available sky coverage while also enabling deeper visible imaging using adaptive-optics sharpened infrared tip-tilt guide sources. Techniques applicable to larger telescope systems will also be tested: the infrared camera will be used to demonstrate advanced multiple region-of-interest tip-tilt guiding methods, and a visitor instrument port will be used for evaluation of other instrumentation, e.g. single-mode and photonic fibers to feed compact spectrographs.

  7. UVMag: Space UV and visible spectropolarimetry

    CERN Document Server

    Pertenais, Martin; Pares, Laurent; Petit, Pascal; Snik, Frans; van harten, Gerard

    2014-01-01

    UVMag is a project of a space mission equipped with a high-resolution spectropolarimeter working in the UV and visible range. This M-size mission will be proposed to ESA at its M4 call. The main goal of UVMag is to measure the magnetic fields, winds and environment of all types of stars to reach a better understanding of stellar formation and evolution and of the impact of stellar environment on the surrounding planets. The groundbreaking combination of UV and visible spectropolarimetric observations will allow the scientists to study the stellar surface and its environment simultaneously. The instrumental challenge for this mission is to design a high-resolution space spectropolarimeter measuring the full-Stokes vector of the observed star in a huge spectral domain from 117 nm to 870 nm. This spectral range is the main difficulty because of the dispersion of the optical elements and of birefringence issues in the FUV. As the instrument will be launched into space, the polarimetric module has to be robust and...

  8. Is Anti-Suppression the Quest for Visibility?

    Directory of Open Access Journals (Sweden)

    Eric S. Hussey, OD

    2015-02-01

    Full Text Available Vision science defines the fundamental action of the vision system to be the generation of visible percepts. Intermittent central suppression (ICS is an intermittent, usually alternating, loss of visual sensation, a repetitive loss of that visual percept. A review of the vision science literature on visibility, Troxler’s Perceptual Fading, and the consequences of loss of visibility suggests that loss of visual motion signal causes loss of visibility. The area of lost visibility is then filled in by a cortical computation mechanism. Fixation, binocular saccades, vergence, and sensory perception are all compromised in loss of visibility. Some of the characteristics of ICS, as well as suspected consequences of ICS, have been difficult to reconcile with the conventional wisdom on suppression. That conventional wisdom suggests that suppression is solely a function of cortical inhibition. Those ICS characteristics and consequences may be better explained if ICS is viewed as a loss of visibility from Troxler’s Fading. Fixation changes and perceptual changes with loss of visibility parallel findings in ICS and the vision-and-dyslexia literature. Research methods to reverse loss of visibility parallel treatment methods for ICS. These parallels suggest that loss of visibility may be diagnosed clinically as ICS, and ICS should be treated with a goal of ensuring bilateral visibility, that is, binocularity.

  9. Accessibility analysis in manufacturing processes using visibility cones

    Institute of Scientific and Technical Information of China (English)

    尹周平; 丁汉; 熊有伦

    2002-01-01

    Accessibility is a kind of important design feature of products,and accessibility analysis has been acknowledged as a powerful tool for solving computational manufacturing problems arising from different manufacturing processes.After exploring the relations among approachability,accessibility and visibility,a general method for accessibility analysis using visibility cones (VC) is proposed.With the definition of VC of a point,three kinds of visibility of a feature,namely complete visibility cone (CVC),partial visibility cone (PVC) and local visibility cone (LVC),are defined.A novel approach to computing VCs is formulated by identifying C-obstacles in the C-space,for which a general and efficient algorithm is proposed and implemented by making use of visibility culling.Lastly,we discuss briefly how to realize accessibility analysis in numerically controlled (NC) machining planning,coordinate measuring machines (CMMs) inspection planning and assembly sequence planning with the proposed methods.

  10. Contabilidad, Finanzas Empresariales y Mano Visible

    Directory of Open Access Journals (Sweden)

    Juan José Durán Herrera

    2004-01-01

    Full Text Available En el ámbito de la Economía y Dirección de la Empresa, la Contabilidad y las Finanzas juegan un papel primordial por cuanto que, prioritariamente, se ocupan de la determinación del valor de la empresa y, respectivamente, de proporcionar y evaluar la información suplementaria necesaria para la formación de expectativas reales sobre el futuro de dicha organización. En la fuerte interdependencia de los programas de investigación de ambas disciplinas -Contabilidad y Finanzas- se entrecruzan los análisis respectivos de la naturaleza de los activos, del gobierno de la empresa como organización y del cálculo de los resultados alcanzados. La investigación contempla los cambios en las circunstancias (instituciones y organizaciones en las que se desarrolla la función financiera y se aplica la contabilidad para medir e informar sobre la realidad de la empresa, evidenciándose el paralelismo, la complementariedad y las diferencias que se producen entre ambas disciplinas. El valor de la empresa como punto de encuentro manifiesta dos aproximaciones: el valor contable basado en datos históricos o en precios corrientes y el valor financiero que estima el valor actualizando los flujos de caja derivados del desarrollo del proyecto empresa. Palabras clave: contabilidad y finanzas empresariales, información contable y decisiones financieras, dirección financiera y contabilidad, mano visible de la empresa. The theory and practice of Accounting and Finance make possible to estimate the value of the firm and, respectively, both provide and evaluate supplementary information that constitudes inputs for the expectations about the nature of organization. The strong interdependence between the researtch programs in both academic disciplines are show in their own analysis about the nature of assets, the governance of the firm and the determination of the profitability of the corporation. The institutional changes influence the research programs of both

  11. Nanoantennas for visible and infrared radiation.

    Science.gov (United States)

    Biagioni, Paolo; Huang, Jer-Shing; Hecht, Bert

    2012-02-01

    Nanoantennas for visible and infrared radiation can strongly enhance the interaction of light with nanoscale matter by their ability to efficiently link propagating and spatially localized optical fields. This ability unlocks an enormous potential for applications ranging from nanoscale optical microscopy and spectroscopy over solar energy conversion, integrated optical nanocircuitry, opto-electronics and density-of-states engineering to ultra-sensing as well as enhancement of optical nonlinearities. Here we review the current understanding of metallic optical antennas based on the background of both well-developed radiowave antenna engineering and plasmonics. In particular, we discuss the role of plasmonic resonances on the performance of nanoantennas and address the influence of geometrical parameters imposed by nanofabrication. Finally, we give a brief account of the current status of the field and the major established and emerging lines of investigation in this vivid area of research.

  12. Electrically Injected UV-Visible Nanowire Lasers

    Energy Technology Data Exchange (ETDEWEB)

    Wang, George T.; Li, Changyi; Li, Qiming; Liu, Sheng; Wright, Jeremy Benjamin; Brener, Igal; Luk, Ting -Shan; Chow, Weng W.; Leung, Benjamin; Figiel, Jeffrey J.; Koleske, Daniel D.; Lu, Tzu-Ming

    2015-09-01

    There is strong interest in minimizing the volume of lasers to enable ultracompact, low-power, coherent light sources. Nanowires represent an ideal candidate for such nanolasers as stand-alone optical cavities and gain media, and optically pumped nanowire lasing has been demonstrated in several semiconductor systems. Electrically injected nanowire lasers are needed to realize actual working devices but have been elusive due to limitations of current methods to address the requirement for nanowire device heterostructures with high material quality, controlled doping and geometry, low optical loss, and efficient carrier injection. In this project we proposed to demonstrate electrically injected single nanowire lasers emitting in the important UV to visible wavelengths. Our approach to simultaneously address these challenges is based on high quality III-nitride nanowire device heterostructures with precisely controlled geometries and strong gain and mode confinement to minimize lasing thresholds, enabled by a unique top-down nanowire fabrication technique.

  13. Visibility-Aware Direct Volume Rendering

    Institute of Scientific and Technical Information of China (English)

    Wai-Ho Mak; Yingcai Wu; Ming-Yuen Chan; Huamin Qu

    2011-01-01

    Direct volume rendering (DVR) is a powerful visualization technique which allows users to effectively explore and study volumetric datasets. Different transparency settings can be flexibly assigned to different structures such that some valuable information can be revealed in direct volume rendered images (DVRIs). However, end-users often feel that some risks are always associated with DVR because they do not know whether any important information is missing from the transparent regions of DVRIs. In this paper, we investigate how to semi-automatically generate a set of DVRIs and also an animation which can reveal information missed in the original DVRIs and meanwhile satisfy some image quality criteria such as coherence. A complete framework is developed to tackle various problems related to the generation and quality evaluation of visibility-aware DVRIs and animations. Our technique can reduce the risk of using direct volume rendering and thus boost the confidence of users in volume rendering systems.

  14. AN OVERVIEW OF VISIBLE LIGHT COMMUNICATION SYSTEMS

    Directory of Open Access Journals (Sweden)

    Taner Cevik

    2015-11-01

    Full Text Available Visible Light Communication (VLC has gained great interest in the last decade due to the rapid developments in Light Emitting Diodes (LEDs fabrication. Efficiency, durability and long life span of LEDs make them a promising residential lighting equipment as well as an alternative cheap and fast data transfer equipment. Appliance of visual light in data communication by means of LEDs has been densely searched in academia. In this paper, we explore the fundamentals and challenges of indoor VLC systems. Basics of optical transmission such as transmitter, receiver, and links are investigated. Moreover, characteristics of channel models in indoor VLC systems are identified and theoretical details about channel modelling are presented in detail.

  15. Nanoantennas for visible and infrared radiation

    Science.gov (United States)

    Biagioni, Paolo; Huang, Jer-Shing; Hecht, Bert

    2012-02-01

    Nanoantennas for visible and infrared radiation can strongly enhance the interaction of light with nanoscale matter by their ability to efficiently link propagating and spatially localized optical fields. This ability unlocks an enormous potential for applications ranging from nanoscale optical microscopy and spectroscopy over solar energy conversion, integrated optical nanocircuitry, opto-electronics and density-of-states engineering to ultra-sensing as well as enhancement of optical nonlinearities. Here we review the current understanding of metallic optical antennas based on the background of both well-developed radiowave antenna engineering and plasmonics. In particular, we discuss the role of plasmonic resonances on the performance of nanoantennas and address the influence of geometrical parameters imposed by nanofabrication. Finally, we give a brief account of the current status of the field and the major established and emerging lines of investigation in this vivid area of research.

  16. Nanoantennas for visible and infrared radiation

    CERN Document Server

    Biagioni, Paolo; Hecht, Bert

    2011-01-01

    Nanoantennas for visible and infrared radiation can strongly enhance the interaction of light with nanoscale matter by their ability to efficiently link propagating and spatially localized optical fields. This ability unlocks an enormous potential for applications ranging from nanoscale optical microscopy and spectroscopy over solar energy conversion, integrated optical nanocircuitry, opto-electronics and density-ofstates engineering to ultra-sensing as well as enhancement of optical nonlinearities. Here we review the current understanding of optical antennas based on the background of both well-developed radiowave antenna engineering and the emerging field of plasmonics. In particular, we address the plasmonic behavior that emerges due to the very high optical frequencies involved and the limitations in the choice of antenna materials and geometrical parameters imposed by nanofabrication. Finally, we give a brief account of the current status of the field and the major established and emerging lines of inves...

  17. Visible digital watermarking system using perceptual models

    Science.gov (United States)

    Cheng, Qiang; Huang, Thomas S.

    2001-03-01

    This paper presents a visible watermarking system using perceptual models. %how and why A watermark image is overlaid translucently onto a primary image, for the purposes of immediate claim of copyright, instantaneous recognition of owner or creator, or deterrence to piracy of digital images or video. %perceptual The watermark is modulated by exploiting combined DCT-domain and DWT-domain perceptual models. % so that the watermark is visually uniform. The resulting watermarked image is visually pleasing and unobtrusive. The location, size and strength of the watermark vary randomly with the underlying image. The randomization makes the automatic removal of the watermark difficult even though the algorithm is known publicly but the key to the random sequence generator. The experiments demonstrate that the watermarked images have pleasant visual effect and strong robustness. The watermarking system can be used in copyright notification and protection.

  18. Macroscopic Invisibility Cloaking of Visible Light

    CERN Document Server

    Chen, Xianzhong; Zhang, Jingjing; Jiang, Kyle; Pendry, John B; Zhang, Shuang

    2010-01-01

    Invisibility cloaks of light, which used to be confined to the imagination, have now been turned into a scientific reality, thanks to the enabling theoretical tools of transformation optics and conformal mapping. Inspired by those theoretical works, the experimental realisation of electromagnetic invisibility cloaks has been reported at various electromagnetic frequencies. All the invisibility cloaks demonstrated thus far, however, have relied on nano- or micro-fabricated artificial composite materials with spatially varying electromagnetic properties, which limit the size of the cloaked region to a few wavelengths. Here we report realisation of a macroscopic volumetric invisibility cloak constructed from natural birefringent crystals. The cloak operates at visible frequencies and is capable of hiding three-dimensional objects of the scale of centimetres and millimetres. Our work opens avenues for future applications with macroscopic cloaking devices.

  19. Making the Dzyaloshinskii-Moriya interaction visible

    Science.gov (United States)

    Hrabec, A.; Belmeguenai, M.; Stashkevich, A.; Chérif, S. M.; Rohart, S.; Roussigné, Y.; Thiaville, A.

    2017-06-01

    Brillouin light spectroscopy is a powerful and robust technique for measuring the interfacial Dzyaloshinskii-Moriya interaction in thin films with broken inversion symmetry. Here, we show that the magnon visibility, i.e., the intensity of the inelastically scattered light, strongly depends on the thickness of the dielectric seed material—SiO2. By using both, analytical thin-film optics and numerical calculations, we reproduce the experimental data. We therefore provide a guideline for the maximization of the signal by adapting the substrate properties to the geometry of the measurement. Such a boost-up of the signal eases the magnon visualization in ultrathin magnetic films, speeds-up the measurement and increases the reliability of the data.

  20. Visible-Light-Induced Click Chemistry.

    Science.gov (United States)

    Mueller, Jan O; Schmidt, Friedrich G; Blinco, James P; Barner-Kowollik, Christopher

    2015-08-24

    A rapid and catalyst-free cycloaddition system for visible-light-induced click chemistry is reported. A readily accessible photoreactive 2H-azirine moiety was designed to absorb light at wavelengths above 400 nm. Irradiation with low-energy light sources thus enables efficient small-molecule synthesis with a diverse range of multiple-bond-containing compounds. Moreover, in order to demonstrate the efficiency of the current approach, quantitative ligation of the photoactivatable chromophore with functional polymeric substrates was performed and full conversion with irradiation times of only 1 min at ambient conditions was achieved. The current report thus presents a highly efficient method for applications involving selective cycloaddition to electron-deficient multiple-bond-containing materials.

  1. Novel visible light activated type 1 photosensitizers

    Science.gov (United States)

    Rajagopalan, Raghavan; Karwa, Amolkumar; Poreddy, Amruta R.; Lusiak, Przemyslaw M.; Pandurangi, Raghoottama S.; Cantrell, Gary L.; Dorshow, Richard B.

    2010-02-01

    Photodynamic therapy of tumors involving Type 2 photosenstizers has been conspicuously successful, but the Type 1 process, in contrast, has not received much attention despite its considerable potential. Accordingly, several classes of molecules containing fragile bonds such as azido (-N=N=N), azo (-N=N-), and oxaza (-N-O-) functional groups that produce reactive intermediates such as radicals and nitrenes upon photoexcitation with visible light were prepared and tested for cell viability using U397 leukemia cell line. The cells were incubated with the photosensitizer at various concentrations, and were illuminated for 5, 10, and 20 minutes. The results show that all the photosensitizers caused cell death compared to the controls when exposed to both the photosensitizers and light.

  2. Representation and Visibility. Roma in the Media

    Directory of Open Access Journals (Sweden)

    Magdalena Ratajczak

    2011-12-01

    Full Text Available This article is divided into three main parts. The first is an overview of the situation of the Roma minorities in Slovenia and Poland. The second part of the article presents minority broadcast media and the main elements of the legal and institutional framework they operate in. Finally, this article focuses on the visibility of Roma in the media. This article draws attention to cultural pluralism and how cultural pluralism is implemented by the public service broadcasters in Poland and Slovenia, particularly in the context of the presence of Roma minorities in the media. The research is based on 15 interviews carried out in Slovenia and Poland between 2006-2009 with journalists, editors, researchers, workers of NGOs, government representatives and Roma minority leaders. This study is also based on policy documents, reports of governments, NGOs and international organisations, academic literature and content analysis of Roma minority media.

  3. Coded source imaging simulation with visible light

    Science.gov (United States)

    Wang, Sheng; Zou, Yubin; Zhang, Xueshuang; Lu, Yuanrong; Guo, Zhiyu

    2011-09-01

    A coded source could increase the neutron flux with high L/ D ratio. It may benefit a neutron imaging system with low yield neutron source. Visible light CSI experiments were carried out to test the physical design and reconstruction algorithm. We used a non-mosaic Modified Uniformly Redundant Array (MURA) mask to project the shadow of black/white samples on a screen. A cooled-CCD camera was used to record the image on the screen. Different mask sizes and amplification factors were tested. The correlation, Wiener filter deconvolution and Richardson-Lucy maximum likelihood iteration algorithm were employed to reconstruct the object imaging from the original projection. The results show that CSI can benefit the low flux neutron imaging with high background noise.

  4. Macroscopic Invisible Cloak for Visible Light

    CERN Document Server

    Zhang, Baile; Liu, Xiaogang; Barbastathis, George

    2011-01-01

    Invisibility cloaks, a subject that usually occurs in science fiction and myths, have attracted wide interest recently because of their possible realization. The biggest challenge to true invisibility is known to be the cloaking of a macroscopic object in the broad range of wavelengths visible to the human eye. Here we experimentally solve this problem by incorporating the principle of transformation optics into a conventional optical lens fabrication with low-cost materials and simple manufacturing techniques. A transparent cloak made of two pieces of calcite is created. This cloak is able to conceal a macroscopic object with a maximum height of 2 mm, larger than 3500 free-space-wavelength, inside a transparent liquid environment. Its working bandwidth encompassing red, green and blue light is also demonstrated.

  5. Visible Light Communications towards 5G

    Directory of Open Access Journals (Sweden)

    S. Zvanovec

    2015-04-01

    Full Text Available 5G networks have to offer extremely high capacity for novel streaming applications. One of the most promising approaches is to embed large numbers of co-operating small cells into the macro-cell coverage area. Alternatively, optical wireless based technologies can be adopted as an alternative physical layer offering higher data rates. Visible light communications (VLC is an emerging technology for future high capacity communication links (it has been accepted to 5GPP in the visible range of the electromagnetic spectrum (~370–780 nm utilizing light-emitting diodes (LEDs simultaneously provide data transmission and room illumination. A major challenge in VLC is the LED modulation bandwidths, which are limited to a few MHz. However, myriad gigabit speed transmission links have already been demonstrated. Non line-of-sight (NLOS optical wireless is resistant to blocking by people and obstacles and is capable of adapting its’ throughput according to the current channel state information. Concurrently, organic polymer LEDs (PLEDs have become the focus of enormous attention for solid-state lighting applications due to their advantages over conventional white LEDs such as ultra-low costs, low heating temperature, mechanical flexibility and large photoactive areas when produced with wet processing methods. This paper discusses development of such VLC links with a view to implementing ubiquitous broadcasting networks featuring advanced modulation formats such as orthogonal frequency division multiplexing (OFDM or carrier-less amplitude and phase modulation (CAP in conjunction with equalization techniques. Finally, this paper will also summarize the results of the European project ICT COST IC1101 OPTICWISE (Optical Wireless Communications - An Emerging Technology dealing VLC and OLEDs towards 5G networks.

  6. Enhancing the visibility of injuries with narrow-banded beams of light within the visible light spectrum.

    Science.gov (United States)

    Limmen, Roxane M; Ceelen, Manon; Reijnders, Udo J L; Joris Stomp, S; de Keijzer, Koos C; Das, Kees

    2013-03-01

    The use of narrow-banded visible light sources in improving the visibility of injuries has been hardly investigated, and studies examining the extent of this improvement are lacking. In this study, narrow-banded beams of light within the visible light spectrum were used to explore their ability in improving the visibility of external injuries. The beams of light were induced by four crime-lites(®) providing narrow-banded beams of light between 400 and 550 nm. The visibility of the injuries was assessed through specific long-pass filters supplied with the set of crime-lites(®) . Forty-three percent of the examined injuries improved in visibility by using the narrow-banded visible light. In addition, injuries were visualized that were not visible or just barely visible to the naked eye. The improvements in visibility were particularly marked with the use of crime-lites(®) "violet" and "blue" covering the spectrum between 400-430 and 430-470 nm. The simple noninvasive method showed a great potential contribution in injury examination.

  7. Chrominance watermark embed using a full-color visibility model

    Science.gov (United States)

    Bradley, Brett; Reed, Alastair; Stach, John

    2012-03-01

    A watermark embed scheme has been developed to insert a watermark with the maximum signal strength for a user selectable visibility constraint. By altering the watermark strength and direction to meet a visibility constraint, the maximum watermark signal for a particular image is inserted. The method consists of iterative embed software and a full color human visibility model plus a watermark signal strength metric. The iterative approach is based on the intersections between hyper-planes, which represent visibility and signal models, and the edges of a hyper-volume, which represent output device visibility and gamut constraints. The signal metric is based on the specific watermark modulation and detection methods and can be adapted to other modulation approaches. The visibility model takes into account the different contrast sensitivity functions of the human eye to L, a and b, and masking due to image content.

  8. Visible transmission response of nanoscale complementary metamaterials for sensing applications.

    Science.gov (United States)

    Liu, Zhe; Xia, Xiaoxiang; Sun, Yimin; Yang, Haifang; Chen, Rongyan; Liu, Baoli; Quan, Baogang; Li, Junjie; Gu, Changzhi

    2012-07-11

    Metamaterials (MMs) have shown huge potential in sensing applications by detecting their optical properties, which can be designed to operate at frequencies from visible to mid-IR. Here we constructed complementary split ring resonator (CSRR) based metamaterials in nanoscale with unit length of 100 nm and slit width of 30 nm, and observed obvious responses in the visible waveband from 600 to 900 nm. These visible responses show a good tunability with the structure's geometry, and are well suited for dielectric detection. We demonstrated good refractive index sensing of CSRR based metamaterials in the visible region under both 0° and 90° polarized incidence. Our results extend the study of CSRR based metamaterials to the visible region, which is expected to deepen the understanding of the response mechanism of CSRRs and benefit their sensing applications in the visible region.

  9. Infrared and visible images fusion based on RPCA and NSCT

    Science.gov (United States)

    Fu, Zhizhong; Wang, Xue; Xu, Jin; Zhou, Ning; Zhao, Yufei

    2016-07-01

    Current infrared and visible images fusion algorithms cannot efficiently extract the object information in the infrared image while retaining the background information in visible image. To address this issue, we propose a new infrared and visible image fusion algorithm by taking advantage of robust principal component analysis (RPCA) and non-subsampled Contourlet transform (NSCT). Firstly, RPCA decomposition is performed on the infrared and visible images respectively to obtain their corresponding sparse matrixes, which can well represent the sparse feature of images. Secondly, the infrared and visible images are decomposed into low frequency sub-band and high-frequency sub-band coefficients by using NSCT. Subsequently, the sparse matrixes are used to guide the fusion rule of low frequency sub-band coefficients and high frequency sub-band coefficients. Experimental results demonstrate that our fusion algorithm can highlight the infrared objects as well as retain the background information in visible image.

  10. Visibility graph analysis on heartbeat dynamics of meditation training

    Science.gov (United States)

    Jiang, Sen; Bian, Chunhua; Ning, Xinbao; Ma, Qianli D. Y.

    2013-06-01

    We apply the visibility graph analysis to human heartbeat dynamics by constructing the complex networks of heartbeat interval time series and investigating the statistical properties of the network before and during chi and yoga meditation. The experiment results show that visibility graph analysis can reveal the dynamical changes caused by meditation training manifested as regular heartbeat, which is closely related to the adjustment of autonomous neural system, and visibility graph analysis is effective to evaluate the effect of meditation.

  11. Visible Light Mediated Photoredox Catalytic Arylation Reactions.

    Science.gov (United States)

    Ghosh, Indrajit; Marzo, Leyre; Das, Amrita; Shaikh, Rizwan; König, Burkhard

    2016-08-16

    Introducing aryl- and heteroaryl moieties into molecular scaffolds are often key steps in the syntheses of natural products, drugs, or functional materials. A variety of cross-coupling methods have been well established, mainly using transition metal mediated reactions between prefunctionalized substrates and arenes or C-H arylations with functionalization in only one coupling partner. Although highly developed, one drawback of the established sp2-sp2 arylations is the required transition metal catalyst, often in combination with specific ligands and additives. Therefore, photoredox mediated arylation methods have been developed as alternative over the past decade. We begin our survey with visible light photo-Meerwein arylation reactions, which allow C-H arylation of heteroarenes, enones, alkenes, and alkynes with organic dyes, such as eosin Y, as the photocatalyst. A good number of examples from different groups illustrate the broad application of the reaction in synthetic transformations. While initially only photo-Meerwein arylation-elimination processes were reported, the reaction was later extended to photo-Meerwein arylation-addition reactions giving access to the photoinduced three component synthesis of amides and esters from alkenes, aryl diazonium salts, nitriles or formamides, respectively. Other substrates with redox-active leaving groups have been explored in photocatalyzed arylation reactions, such as diaryliodonium and triarylsulfonium salts, and arylsulfonyl chlorides. We discus some examples with their scope and limitations. The scope of arylation reagents for photoredox reactions was extended to aryl halides. The challenge here is the extremely negative reduction potential of aryl halides in the initial electron transfer step compared to, e.g., aryl diazonium or diaryliodonium salts. In order to reach reduction potentials over -2.0 V vs SCE two consecutive photoinduced electron transfer steps were used. The intermediary formed colored radical

  12. Recent developments with the visible nulling coronagraph

    Science.gov (United States)

    Hicks, Brian A.; Lyon, Richard G.; Bolcar, Matthew R.; Clampin, Mark; Petrone, Peter; Helmbrecht, Michael A.; Howard, Joseph M.; Miller, Ian J.

    2016-08-01

    A wide array of general astrophysics studies including detecting and characterizing habitable exoplanets could be enabled by a future large segmented telescope with sensitivity in the UV, optical, and infrared bands. When paired with a starshade or coronagraph, such an observatory could enable direct imaging and detailed spectroscopic observations of nearby Earth-like habitable zone planets. Over the past several years, a laboratory-based Visible Nulling Coronagraph (VNC) has evolved to reach requisite contrasts over a 1 nm bandwidth at narrow source angle separation using a segmented deformable mirror in one arm of a Mach-Zehnder layout. More recent efforts targeted broadband performance following the addition of two sets of half-wave Fresnel rhomb achromatic phase shifters (APS) with the goal of reaching 10-9 contrast, at a separation of 2λ/D, using a 40 nm (6%) bandwidth single mode fiber source. Here we present updates on the VNC broadband nulling effort, including approaches to addressing system contrast limitations.

  13. Visible light polaroastrometry of astronomical objects

    CERN Document Server

    Safonov, Boris

    2015-01-01

    We propose a method to measure difference between positions of centroids of polarized and total flux of astronomical object in visible light, which we call for brevity polaroastrometry. Method efficiency is being demonstrated by the example of reduction of observations carried out with an instrument combining features of two-beam polarimeter with rotating half-wave plate and speckle interferometer, at 70-cm telescope in $V$ band. For the total number of accumulated photoelectrons $N_e=10^9$, which corresponds to series duration of 500 sec and object magnitude $V=6^m$, the method precision is 60-70 $\\mu$as in terms of 1$\\sigma$. At smaller $N_e$ precision decays as $\\sim 1.7^{\\prime\\prime}/\\sqrt{N_e}$, while at larger $N_e$ it remains the same due to imperfections of the half-wave plate. For the main sequence stars, non-polarized and polarized by interstellar dust, we didn't detect significant polaroastrometric signal. For the Mira variable star $\\chi$ Cyg total amplitudes of the polaricenters were found to be...

  14. Horizontal visibility graphs from integer sequences

    Science.gov (United States)

    Lacasa, Lucas

    2016-09-01

    The horizontal visibility graph (HVG) is a graph-theoretical representation of a time series and builds a bridge between dynamical systems and graph theory. In recent years this representation has been used to describe and theoretically compare different types of dynamics and has been applied to characterize empirical signals, by extracting topological features from the associated HVGs which have shown to be informative on the class of dynamics. Among some other measures, it has been shown that the degree distribution of these graphs is a very informative feature that encapsulates nontrivial information of the series's generative dynamics. In particular, the HVG associated to a bi-infinite real-valued series of independent and identically distributed random variables is a universal exponential law P(k)=(1/3){(2/3)}k-2, independent of the series marginal distribution. Most of the current applications have however only addressed real-valued time series, as no exact results are known for the topological properties of HVGs associated to integer-valued series. In this paper we explore this latter situation and address univariate time series where each variable can only take a finite number n of consecutive integer values. We are able to construct an explicit formula for the parametric degree distribution {P}n(k), which we prove to converge to the continuous case for large n and deviates otherwise. A few applications are then considered.

  15. Efficient silicon metasurfaces for visible light

    CERN Document Server

    Zhou, Zhenpeng; Su, Rongbin; Yao, Beimeng; Fang, Hanlin; Li, Kezheng; Zhou, Lidan; Liu, Jin; Stellinga, Daan; Reardon, Christopher P; Krauss, Thomas F; Wang, Xuehua

    2016-01-01

    Dielectric metasurfaces require high refractive index contrast materials for optimum performance. This requirement imposes a severe restraint; devices have either been demonstrated at wavelengths of 700nm and above using high-index semiconductors such as silicon, or they use lower index dielectric materials such as TiO$_{2}$ or Si$_{3}$N$_{4}$ and operate in the visible wavelength regime. Here, we show that the high refractive index of silicon can be exploited at wavelengths as short as 532 nm by demonstrating a silicon metasurface with a transmission efficiency of 47% at this wavelength. The metasurface consists of a graded array of silicon posts arranged in a square lattice on a quartz substrate. We show full 2{\\pi} phase control and we experimentally demonstrate polarization-independent beam deflection at 532nm wavelength. The crystalline silicon is placed on a quartz substrate by a bespoke layer transfer technique and we note that an efficiency >70% may be achieved for a further optimized structure in the...

  16. The Visible Spectrum of Titanium Dioxide

    Science.gov (United States)

    Zhuang, Xiujuan; Steimle, Timothy C.; Nagarajann, Ramya; Maier, John P.

    2010-06-01

    Bulk TiO2 is a widely used photo-activated catalytic material, yet poorly understood. Much of the motivation for studies of molecular TiO2 is the observation that there is a smooth correlation of the molecular electronic states to the band gap of the bulk. The field-free energy levels of the ground state of the monomer have been fully characterized by microwave spectroscopy. Here we report on the visible spectrum in the region between 18200 cm-1 to 18750 cm-1 of a cold molecular beam sample of TiO2 using laser induced fluorescence detection and mass-selected REMPI. Bands at 18240 cm-1, 18411 cm-1 and 18470 cm-1 were recorded at a resolution of 40 MHz and rotationally analyzed. The dispersed fluorescence of 18411 cm-1 and 18470 cm-1 bands were analyzed to produce a set of vibrational parameters for the ground state. The optical Stark spectra of the 18411 cm-1 and 18470 cm-1 bands were recorded and analyzed to determine permanent electric dipole moments and compared with the results for the band at 18655 cm-1. H.J. Zhai and L.-S. Wang JACS 129 3022, 2007. S.Brunken; H. S. P. Muller; K.M. Menten; M. C. McCarthy and P. Thaddeus Ap. J. 676 1367, 2008. H.Wang; T.C. Steimle; C. Apetrei and J.P. Maier PCCP 11 2649, 2008.

  17. VIS: the visible imager for Euclid

    CERN Document Server

    Cropper, Mark; James, A; Mellier, Y; Martignac, J; di Giorgio, A -M; Paltani, S; Genolet, L; Fourmond, J -J; Cara, C; Amiaux, J; Guttridge, P; Walton, D; Thomas, P; Rees, K; Pool, P; Endicott, J; Holland, A; Gow, J; Murray, N; Duvet, L; Augueres, J -L; Laureijs, R; Gondoin, P; Kitching, T; Massey, R; Hoekstra, H

    2012-01-01

    Euclid-VIS is a large format visible imager for the ESA Euclid space mission in their Cosmic Vision program, scheduled for launch in 2019. Together with the near infrared imaging within the NISP instrument it forms the basis of the weak lensing measurements of Euclid. VIS will image in a single r+i+z band from 550-900 nm over a field of view of ~0.5 deg2. By combining 4 exposures with a total of 2240 sec, VIS will reach to V=24.5 (10{\\sigma}) for sources with extent ~0.3 arcsec. The image sampling is 0.1 arcsec. VIS will provide deep imaging with a tightly controlled and stable point spread function (PSF) over a wide survey area of 15000 deg2 to measure the cosmic shear from nearly 1.5 billion galaxies to high levels of accuracy, from which the cosmological parameters will be measured. In addition, VIS will also provide a legacy imaging dataset with an unprecedented combination of spatial resolution, depth and area covering most of the extra-Galactic sky. Here we will present the results of the study carried ...

  18. Fraud Risk and the Visibility of Carbon

    Directory of Open Access Journals (Sweden)

    Peter Martin

    2013-09-01

    Full Text Available In recent years, carbon has been increasingly rendered ‘visible’ both discursively and through political processes that have imbued it with economic value. Greenhouse gas emissions have been constructed as social and environmental costs and their reduction or avoidance as social and economic gain. The ‘marketisation’ of carbon, which has been facilitated through various compliance schemes such as the European Union Emissions Trading Scheme, the Kyoto Protocol, the proposed Australian Emissions Reduction Scheme and through the voluntary carbon credit market, have attempted to bring carbon into the ‘foreground’ as an economic liability and/or opportunity. Accompanying the increasing economic visibility of carbon are reports of frauds and scams – the ‘gaming of carbon markets’(Chan 2010. As Lohmann (2010: 21 points out, ‘what are conventionally classed as scams or frauds are an inevitable feature of carbon offset markets, not something that could be eliminated by regulation targeting the specific businesses or state agencies involved’. This paper critiques the disparate discourses of fraud risk in carbon markets and examines cases of fraud within emerging landscapes of green criminology.

  19. VIS: the visible imager for Euclid

    CERN Document Server

    Cropper, Mark; Niemi, S; Azzollini, R; Denniston, J; Szafraniec, M; Awan, S; Mellier, Y; Berthe, M; Martignac, J; Cara, C; di Giorgio, A -M; Sciortino, A; Bozzo, E; Genolet, L; Cole, R; Philippon, A; Hailey, M; Hunt, T; Swindells, I; Holland, A; Gow, J; Murray, N; Hall, D; Skottfelt, J; Amiaux, J; Laureijs, R; Racca, G; Salvignol, J -C; Short, A; Alvarez, J Lorenzo; Kitching, T; Hoekstra, H; Massey, R; Israel, H

    2016-01-01

    Euclid-VIS is the large format visible imager for the ESA Euclid space mission in their Cosmic Vision program, scheduled for launch in 2020. Together with the near infrared imaging within the NISP instrument, it forms the basis of the weak lensing measurements of Euclid. VIS will image in a single r+i+z band from 550-900 nm over a field of view of ~0.5 deg2. By combining 4 exposures with a total of 2260 sec, VIS will reach to deeper than mAB=24.5 (10sigma) for sources with extent ~0.3 arcsec. The image sampling is 0.1 arcsec. VIS will provide deep imaging with a tightly controlled and stable point spread function (PSF) over a wide survey area of 15000 deg2 to measure the cosmic shear from nearly 1.5 billion galaxies to high levels of accuracy, from which the cosmological parameters will be measured. In addition, VIS will also provide a legacy dataset with an unprecedented combination of spatial resolution, depth and area covering most of the extra-Galactic sky. Here we will present the results of the study ca...

  20. A proposed visible FEL Facility at Boeing

    Energy Technology Data Exchange (ETDEWEB)

    Dowell, D.H.; Adamski, J.L.; Hayward, T.D. [Boeing Defense & Space Group, Seattle, WA (United States)] [and others

    1995-12-31

    A 1-kW average power, visible wavelength FEL is described, based on a 120-MeV, 0.1. A macropulse average current linac operating at a duty factor of 0. 6% and having average beam power of 70 kW. The accelerator will employ a demonstrated photoinjector, 18-MeV, 433-MHz linac as an injector, followed by a 1300-MHz longitudinal phase space {open_quotes} linearizer,{close_quotes} a magnetic buncher chicane, and seven 1300-MHz, pulsed traveling wave linac sections. The magnets used to transport the beam from the linac to the FEL centerline, the 5-m THUNDER wiggler, and the optical resonator will be reclaimed from previous FEL demonstration experiments. We expect to attain pulse lengths of 7 ps for 3.5 nC, with minimal distortion of the pulse profile and normalized rms emittance of 7.5 {+-} 2.5 {pi} mm-mr. FELEX projects a laser conversion efficiency of 4.3 %, yielding average output of 3 kW.

  1. Estimation of the average visibility in central Europe

    Science.gov (United States)

    Horvath, Helmuth

    Visibility has been obtained from spectral extinction coefficients measured with the University of Vienna Telephotometer or size distributions determined with an Aerosol Spectrometer. By measuring the extinction coefficient in different directions, possible influences of local sources could be determined easily. A region, undisturbed by local sources usually had a variation of extinction coefficient of less than 10% in different directions. Generally good visibility outside population centers in Europe is considered as 40-50 km. These values have been found independent of the location in central Europe, thus this represents the average European "clean" air. Under rare occasions (normally rapid change of air mass) the visibility can be 100-150 km. In towns, the visibility is a factor of approximately 2 lower. In comparison to this the visibility in remote regions of North and South America is larger by a factor of 2-4. Obviously the lower visibility in Europe is caused by its higher population density. Since the majority of visibility reducing particulate emissions come from small sources such as cars or heating, the emissions per unit area can be considered proportional to the population density. Using a simple box model and the visibility measured in central Europe and in Vienna, the difference in visibility inside and outside the town can be explained quantitatively. It thus is confirmed, that the generally low visibility in central Europe is a consequence of the emissions in connection with human activities and the low visibility (compared, e.g. to North or South America) in remote location such as the Alps is caused by the average European pollution.

  2. Deriving atmospheric visibility from satellite retrieved aerosol optical depth

    Science.gov (United States)

    Riffler, M.; Schneider, Ch.; Popp, Ch.; Wunderle, S.

    2009-04-01

    Atmospheric visibility is a measure that reflects different physical and chemical properties of the atmosphere. In general, poor visibility conditions come along with risks for transportation (e.g. road traffic, aviation) and can negatively impact human health since visibility impairment often implies the presence of atmospheric pollution. Ambient pollutants, particulate matter, and few gaseous species decrease the perceptibility of distant objects. Common estimations of this parameter are usually based on human observations or devices that measure the transmittance of light from an artificial light source over a short distance. Such measurements are mainly performed at airports and some meteorological stations. A major disadvantage of these observations is the gap between the measurements, leaving large areas without any information. As aerosols are one of the most important factors influencing atmospheric visibility in the visible range, the knowledge of their spatial distribution can be used to infer visibility with the so called Koschmieder equation, which relates visibility and atmospheric extinction. In this study, we evaluate the applicability of satellite aerosol optical depth (AOD) products from the Advanced Very High Resolution Radiometer (AVHRR) and Moderate Resolution Imaging Spectroradiometer (MODIS) to infer atmospheric visibility on large spatial scale. First results applying AOD values scaled with the planetary boundary layer height are promising. For the comparison we use a full automated and objective procedure for the estimation of atmospheric visibility with the help of a digital panorama camera serving as ground truth. To further investigate the relation between the vertical measure of AOD and the horizontal visibility data from the Aerosol Robotic Network (AERONET) site Laegeren (Switzerland), where the digital camera is mounted, are included as well. Finally, the derived visibility maps are compared with synoptical observations in central

  3. HL-2A Tokamak Plasma Visible Light Imaging System

    Institute of Scientific and Technical Information of China (English)

    ZHENGYinjia; FENGZhen; LUOCuiwen; CHENGLiaoyuan

    2003-01-01

    Visible imagery is extremely useful to overview the edge and divertor structure. The plasma configuration and the position of the strike lines on the target plates can be also observed by imaging technique. By imaging the edge or core plasma with visible emission in the desired wavelength band, usually with a “tangential” view, the plasma position can be determined in principle.

  4. Terahertz (THz) Radar: A Solution for Degraded Visibility Environments (DVE)

    Science.gov (United States)

    2016-11-01

    AS AN OFFICIAL DEPARTMENT OF THE ARMY POSITION UNLESS SO DESIGNATED BY OTHER AUTHORIZED DOCUMENTS. TRADE NAMES USE OF TRADE NAMES OR...to compensate for environmental conditions, allowing for actionable images in Degraded Visibility Environments (DVE). 14. SUBJECT TERMS Radar...Terahertz (THz) Waves, Degraded Visibility Environments (DVE) 15. NUMBER OF PAGES 22 16. PRICE CODE 17. SECURITY CLASSIFICATION OF REPORT

  5. 49 CFR 236.515 - Visibility of cab signals.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Visibility of cab signals. 236.515 Section 236.515..., MAINTENANCE, AND REPAIR OF SIGNAL AND TRAIN CONTROL SYSTEMS, DEVICES, AND APPLIANCES Automatic Train Stop, Train Control and Cab Signal Systems Standards § 236.515 Visibility of cab signals. The cab signals...

  6. Visible Light Communication Physical Layer Design for Jist Simulation

    Directory of Open Access Journals (Sweden)

    Tomaš Boris

    2014-12-01

    Full Text Available Current advances in computer networking consider using visible light spectrum to encode and decode digital data. This approach is relatively non expensive. However, designing appropriate MAC or any other upper layer protocol for Visible Light Communication (VLC requires appropriate hardware. This paper proposes and implements such hardware simulation (physical layer that is compatible with existing network stack.

  7. Visibly transparent polymer solar cells produced by solution processing.

    Science.gov (United States)

    Chen, Chun-Chao; Dou, Letian; Zhu, Rui; Chung, Choong-Heui; Song, Tze-Bin; Zheng, Yue Bing; Hawks, Steve; Li, Gang; Weiss, Paul S; Yang, Yang

    2012-08-28

    Visibly transparent photovoltaic devices can open photovoltaic applications in many areas, such as building-integrated photovoltaics or integrated photovoltaic chargers for portable electronics. We demonstrate high-performance, visibly transparent polymer solar cells fabricated via solution processing. The photoactive layer of these visibly transparent polymer solar cells harvests solar energy from the near-infrared region while being less sensitive to visible photons. The top transparent electrode employs a highly transparent silver nanowire-metal oxide composite conducting film, which is coated through mild solution processes. With this combination, we have achieved 4% power-conversion efficiency for solution-processed and visibly transparent polymer solar cells. The optimized devices have a maximum transparency of 66% at 550 nm.

  8. Lethal effects of short-wavelength visible light on insects.

    Science.gov (United States)

    Hori, Masatoshi; Shibuya, Kazuki; Sato, Mitsunari; Saito, Yoshino

    2014-12-09

    We investigated the lethal effects of visible light on insects by using light-emitting diodes (LEDs). The toxic effects of ultraviolet (UV) light, particularly shortwave (i.e., UVB and UVC) light, on organisms are well known. However, the effects of irradiation with visible light remain unclear, although shorter wavelengths are known to be more lethal. Irradiation with visible light is not thought to cause mortality in complex animals including insects. Here, however, we found that irradiation with short-wavelength visible (blue) light killed eggs, larvae, pupae, and adults of Drosophila melanogaster. Blue light was also lethal to mosquitoes and flour beetles, but the effective wavelength at which mortality occurred differed among the insect species. Our findings suggest that highly toxic wavelengths of visible light are species-specific in insects, and that shorter wavelengths are not always more toxic. For some animals, such as insects, blue light is more harmful than UV light.

  9. Laser anemometer signals: visibility characteristics and application to particle sizing.

    Science.gov (United States)

    Adrian, R J; Orloff, K L

    1977-03-01

    The signal visibility characteristics of a dual beam laser anemometer operated in a backscatter mode have been investigated both experimentally and analytically. The analysis is based on Mie's electromagnetic scattering theory for spherical particles and is exact within the limitations of the scattering theory. It is shown that the signal visibility is a function of the ratio of the particle diameter to the fringe spacing in a certain, restricted case; but more generally it also depends on the Mie scattering size parameter, refractive index, the illuminating beam polarization, and the size, shape, and location of the light collecting aperture. The character of backscatter signal visibility differs significantly from the forward scatter case, and it is concluded that backscatter measurements of particle diameters using the visibility sizing technique may not always be possible. Restrictions on the forward scatter application of the visibility sizing method are also discussed.

  10. Eagle-i: Making Invisible Resources, Visible

    Science.gov (United States)

    Haendel, M.; Wilson, M.; Torniai, C.; Segerdell, E.; Shaffer, C.; Frost, R.; Bourges, D.; Brownstein, J.; McInnerney, K.

    2010-01-01

    RP-134 The eagle-i Consortium – Dartmouth College, Harvard Medical School, Jackson State University, Morehouse School of Medicine, Montana State University, Oregon Health and Science University (OHSU), the University of Alaska, the University of Hawaii, and the University of Puerto Rico – aims to make invisible resources for scientific research visible by developing a searchable network of resource repositories at research institutions nationwide. Now in early development, it is hoped that the system will scale beyond the consortium at the end of the two-year pilot. Data Model & Ontology: The eagle-i ontology development team at the OHSU Library is generating the data model and ontologies necessary for resource indexing and querying. Our indexing system will enable cores and research labs to represent resources within a defined vocabulary, leading to more effective searches and better linkage between data types. This effort is being guided by active discussions within the ontology community (http://RRontology.tk) bringing together relevant preexisting ontologies in a logical framework. The goal of these discussions is to provide context for interoperability and domain-wide standards for resource types used throughout biomedical research. Research community feedback is welcomed. Architecture Development, led by a team at Harvard, includes four main components: tools for data collection, management and curation; an institutional resource repository; a federated network; and a central search application. Each participating institution will populate and manage their repository locally, using data collection and curation tools. To help improve search performance, data tools will support the semi-automatic annotation of resources. A central search application will use a federated protocol to broadcast queries to all repositories and display aggregated results. The search application will leverage the eagle-i ontologies to help guide users to valid queries via auto

  11. Visible and NIR image fusion using weight-map-guided Laplacian–Gaussian pyramid for improving scene visibility

    Indian Academy of Sciences (India)

    ASHISH V VANMALI; VIKRAM M GADRE

    2017-07-01

    Image visibility is affected by the presence of haze, fog, smoke, aerosol, etc. Image dehazing using either single visible image or visible and near-infrared (NIR) image pair is often considered as a solution to improve the visual quality of such scenes. In this paper, we address this problem from a visible–NIR image fusion perspective, instead of the conventional haze imaging model. The proposed algorithm uses a Laplacian–Gaussian pyramid based multi-resolution fusion process, guided by weight maps generated using local entropy,local contrast and visibility as metrics that control the fusion result. The proposed algorithm is free from any human intervention, and produces results that outperform the existing image-dehazing algorithms both visually as well as quantitatively. The algorithm proves to be efficient not only for the outdoor scenes with or without haze, but also for the indoor scenes in improving scene visibility.

  12. Real-Time Volume Shadow using Visible-Non Visible Algorithm

    Directory of Open Access Journals (Sweden)

    Hoshang Kolivand

    2011-01-01

    Full Text Available Problem statement: Shadows are most important effect to make realistic games and visually appealing images, but they are poor in frame per second. Silhouette detection is most important phases to create real-time shadow. Approach: Present study describes a real-time shadow generated with volume shadow algorithm using Visible-Non Visible algorithm (VNV in virtual environment illuminated by a movable light source to improve the frame per second. Silhouette detection that is most expensive part of shadow creation was described. Triangular method and VNV method were compared. An improved algorithm for volume shadow was proposed and volume shadow using both methods in C+ Opengl implemented. Results: The VNV algorithm increases the number of Frame Per Second (FPS and as a result decreases the cost of implementation. Conclusion: A verified algorithm for volume shadow makes it easy to understand by everyone how to produce real-time shadow in outdoor and indoor virtual environment. It is possible to use it in current commercial games or other virtual reality systems.

  13. Optical pump wavelength dependence in visible-pump visible-probe spectroscopy of noble metals

    Science.gov (United States)

    Sahota, Derek G.; Lobo, Calvin; Duch, Konrad; Dodge, J. Steven

    2012-10-01

    We have developed a femtosecond visible-pump visible-probe reflectometer with individually tunable pump and probe photon energies. The spectrometer has been used to study optically thick films of the noble metals Au and Cu over a wide variety of pump fluences and photon energies. Through comparison between experimental measurements and two-temperature model (TTM) simulations, we estimate an electron-phonon coupling constant, g, of 2.37 ±0.11 x10^16 Wm-3K-1 for Au and 1.19 ±0.13 x10^17 Wm-3K-1 for Cu, consistent with previous studies. The variation of the optical pump parameters allows a more accurate determination of the electron-phonon coupling constant. The relaxation rate, τ, of the thermally excited electrons is shown to be strongly dependent on the peak electron temperature of the excited sample, and only weakly dependent on the pump photon energy. The static dielectric constant is found to significantly underestimate the dependence of the differential reflectivity on the pump photon energy.

  14. EFFECT OF VISIBLE RANGE ELECTROMAGNETIC RADIATIONS ON ESCHERICHIA COLI.

    Science.gov (United States)

    Azeemi, Samina T Yousuf; Shaukat, Saleem Farooq; Azeemi, Khawaja Shamsuddin; Khan, Idrees; Mahmood, Khalid; Naz, Farah

    2017-01-01

    Escherichia coli is the agent responsible for a range of clinical diseases. With emerging antimicrobial resistance, other treatment options including solar/photo-therapy are becoming increasingly common. Visible Range Radiation Therapy/Colour Therapy is an emerging technique in the field of energy/vibrational medicine that uses visible spectrum of Electromagnetic Radiations to cure different diseases. In this study, our goal was to understand the effect of Visible Range Electromagnetic Radiations on E. coli (in vitro) and therefore find out the most appropriate visible range radiation for the treatment of diseases caused by E. coli. A total of 6 non-repetitive E. coli isolates were obtained from urine samples obtained from hospitalized patients with UTI. Single colony of E. coli was inoculated in 3 ml of Lysogeny Broth (LB) and 40 μl of this E. coli suspension was poured into each of the plastic tubes which were then irradiated with six different wavelengths in the visible region (Table. 1) after 18 hours with one acting as a control. The Optical Densities of these irradiated samples were then measured. Furthermore, scanning electron microscopy (TEFCAN ZEGA3) was carried out. The analysis of the microscopic and SEM images of irradiated E. coli samples with six different visible range radiations is representative of The fact that E. coli responded differently to every applied radiation in the visible region and the most profound inhibitory effects were that of 538nm Visible Range Radiation (Green) which proved to be bactericidal and 590nm Visible Range Radiation (yellow) which was bacteriostatic. The enhanced growth of E. coli with varying degrees was clearly observed in 610nm (orange), 644nm (red), 464nm (Purple) and 453nm (blue). It can be concluded that 538nm (Green) and 590nm (Yellow) can effectively be used for treating E. coli borne diseases.

  15. Rethinking on Translator’s Invisibility and Visibility

    Institute of Scientific and Technical Information of China (English)

    李莉

    2014-01-01

    Translator’s Invisibility is Lawrence Venuti’s most famous book. In this book we can conclude his translation theory:translators should be invisible(transparent) or visible in his translation. We will analyze in his opinion which kind of translation is perfect to readers, and how should the translator be visible in his translation by comparing the theories of Friedrich Schleiermach-er and Norman Shapiro. Finally we can get a good translator should use foreignizing translation in order to be visible in his trans-lation.

  16. Website visibility the theory and practice of improving rankings

    CERN Document Server

    Weideman, Melius

    2009-01-01

    The quest to achieve high website rankings in search engine results is a prominent subject for both academics and website owners/coders. Website Visibility marries academic research results to the world of the information practitioner and contains a focused look at the elements which contribute to website visibility, providing support for the application of each element with relevant research. A series of real-world case studies with tested examples of research on website visibility elements and their effect on rankings are reviewed.Written by a well-respected academic and practitioner in the

  17. A review on visible light active perovskite-based photocatalysts.

    Science.gov (United States)

    Kanhere, Pushkar; Chen, Zhong

    2014-12-01

    Perovskite-based photocatalysts are of significant interest in the field of photocatalysis. To date, several perovskite material systems have been developed and their applications in visible light photocatalysis studied. This article provides a review of the visible light (λ > 400 nm) active perovskite-based photocatalyst systems. The materials systems are classified by the B site cations and their crystal structure, optical properties, electronic structure, and photocatalytic performance are reviewed in detail. Titanates, tantalates, niobates, vanadates, and ferrites form important photocatalysts which show promise in visible light-driven photoreactions. Along with simple perovskite (ABO3) structures, development of double/complex perovskites that are active under visible light is also reviewed. Various strategies employed for enhancing the photocatalytic performance have been discussed, emphasizing the specific advantages and challenges offered by perovskite-based photocatalysts. This review provides a broad overview of the perovskite photocatalysts, summarizing the current state of the work and offering useful insights for their future development.

  18. NOS CO-OPS Meteorological Data, Visibility, 6-Minute

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This dataset has Visibility data from NOAA NOS Center for Operational Oceanographic Products and Services (CO-OPS). WARNING: These preliminary data have not been...

  19. Development of a lesbian, gay, bisexual visibility management scale.

    Science.gov (United States)

    Lasser, Jon; Ryser, Gail R; Price, Larry R

    2010-01-01

    Many lesbian, gay, and bisexual (LGB) individuals manage the degree to which their sexual orientation is known to others. Visibility management, the process of regulating the exposure of one's orientation, is an important part of the lesbian/gay/bisexual experience in community, family, and virtually all other social settings. The degree to which one allows his or her sexual orientation to be visible can have a profound impact on stress, health, self-esteem, interpersonal relationships, and quality of life. The purpose of the present study was to develop a valid and reliable measure of visibility management. The Lesbian, Gay, Bisexual-Visibility Management Scale was constructed and piloted with a small sample of LGB adults. Results support the potential utility of the LGB scale based on satisfactory evidence of construct validity, item-level discrimination, and subscale reliability.

  20. Mechanochemical Synthesis of Visible Light Sensitive Titanium Dioxide Photocatalyst

    Directory of Open Access Journals (Sweden)

    Jan Šubrt

    2011-01-01

    Full Text Available Phase transition of anatase nanoparticles into the phases TiO2-II and rutile under grinding was studied. The addition of ammonium carbamate to the reaction mixture inhibits the phase conversion and the cold welding of particles. The UV-visible absorption spectrum showed narrowing the band gap width after grinding with an ammonium carbamate additive resulting in shift of the light absorption of the ground sample towards the visible region. By EPR, intensive formation of OH• radical at irradiation of the sample with both UV (λ > 300 nm and visible (λ > 435 nm light was observed. High photocatalytic activity of the ground sample in visible light region was demonstrated also by measurement of kinetics of the photocatalytic decomposition of 4-chlorophenol.

  1. A Democratic Gauge Model for Dark/Visible Matter Symmetry

    CERN Document Server

    Oliveira, O; Hussein, M S; de Paula, W; Frederico, T

    2011-01-01

    We develop a model for visible matter-dark matter interaction based on the exchange of a weakly interacting massive gauge boson called herein the WIMG. Our model hinges on the assumption that all known particles in the visible matter have their counterparts in the dark matter. We postulate six families of particles five of which are dark. This leads to the unavoidable postulation of six parallel worlds, the visible one and five invisible worlds. We give arguments on particle decays and lifetimes that set a limit on the mass of the WIMG, the gray boson responsible for the very meager communication among these worlds. The 5:1 ratio of dark to visible matter is taken for granted.

  2. Visibility and Violence in Petitions from Roman Egypt

    OpenAIRE

    Ari Z. Bryen

    2010-01-01

    The complaints by victims of violence preserved in the papyri emphasize visible physical damage and the loss of dignity; in these narratives about violence, petitioners reveal an unexpectedly complex understanding of local hierarchies.

  3. Health Communications: Nursing Education for Increased Visibility and Effectiveness.

    Science.gov (United States)

    Chaffee, Mary

    2000-01-01

    To improve the visibility of nurses in mass media, health communications content should be integrated into nursing education. Nurses equipped with advanced communication skills, media expertise and teaching strategies can empower the profession to influence the health care environment. (SK)

  4. Implementing Mobile Virtual Exhibition to Increase Cultural Heritage Visibility

    National Research Council Canada - National Science Library

    Cristian Ciurea; Alin Zamfiroiu; Alin Grosu

    2014-01-01

      The paper presents an implementation of iOS mobile application designed as a virtual exhibition, which aims to increase the accessibility and visibility of physical objects that composite cultural heritage elements...

  5. Chain-reaction crash on a highway in high visibility

    Science.gov (United States)

    Nagatani, Takashi

    2016-05-01

    We study the chain-reaction crash (multiple-vehicle collision) in high-visibility condition on a highway. In the traffic situation, drivers control their vehicles by both gear-changing and braking. Drivers change the gears according to the headway and brake according to taillights of the forward vehicle. We investigate whether or not the first collision induces the chain-reaction crash numerically. It is shown that dynamic transitions occur from no collisions, through a single collision, to multiple collisions with decreasing the headway. Also, we find that the dynamic transition occurs from the finite chain reaction to the infinite chain reaction when the headway is less than the critical value. We compare the multiple-vehicle collisions in high-visibility with that in low-visibility. We derive the transition points and the region maps for the chain-reaction crash in high visibility.

  6. Robust pedestrian detection by combining visible and thermal infrared cameras

    National Research Council Canada - National Science Library

    Lee, Ji Hoon; Choi, Jong-Suk; Jeon, Eun Som; Kim, Yeong Gon; Le, Toan Thanh; Shin, Kwang Yong; Lee, Hyeon Chang; Park, Kang Ryoung

    2015-01-01

    .... However, most of the previous studies use a single camera system, either a visible light or thermal camera, and their performances are affected by various factors such as shadow, illumination change...

  7. Global trends in visibility: implications for dust sources

    Directory of Open Access Journals (Sweden)

    N. M. Mahowald

    2007-06-01

    Full Text Available There is a large uncertainty in the relative roles of human land use, climate change and carbon dioxide fertilization in changing desert dust source strength over the past 100 years, and the overall sign of human impacts on dust is not known. We used visibility data from meteorological stations in dusty regions to assess the anthropogenic impact on long term trends in desert dust emissions. We did this by looking at time series of visibility derived variables and their correlations with precipitation, drought, winds, land use and grazing. Visibility data are available at thousands of stations globally from 1900 to the present, but we focused on 357 stations with more than 30 years of data in regions where mineral aerosols play a dominant role in visibility observations. We evaluated the 1974 to 2003 time period because most of these stations have reliable records only during this time. We first evaluated the visibility data against AERONET aerosol optical depth data, and found that only in dusty regions are the two moderately correlated. Correlation coefficients between visibility-derived variables and AERONET optical depths indicate a moderate correlation (0.47, consistent with capturing about 20% of the variability in optical depths. Two visibility-derived variables appear to compare the best with AERONET observations: the fraction of observations with visibility less than 5 km (VIS5 and the surface extinction (EXT. Regional trends show that in many dusty places, VIS5 and EXT are statistically significantly correlated with the Palmer drought severity index (based on precipitation and temperature or surface wind speeds, consistent with dust temporal variability being largely driven by meteorology. This is especially true for North African and Chinese dust sources, but less true in the Middle East, Australia or South America, where there are not consistent patterns in the correlations. Climate indices such as El Nino or the North Atlantic

  8. Global trends in visibility: Implications for dust sources

    Science.gov (United States)

    Mahowald, N.M.; Ballantine, J.A.; Feddema, J.; Ramankutty, N.

    2007-01-01

    There is a large uncertainty in the relative roles of human land use, climate change and carbon dioxide fertilization in changing desert dust source strength over the past 100 years, and the overall sign of human impacts on dust is not known. We used visibility data from meteorological stations in dusty regions to assess the anthropogenic impact on long term trends in desert dust emissions. We did this by looking at time series of visibility derived variables and their correlations with precipitation, drought, winds, land use and grazing. Visibility data are available at thousands of stations globally from 1900 to the present, but we focused on 357 stations with more than 30 years of data in regions where mineral aerosols play a dominant role in visibility observations. We evaluated the 1974 to 2003 time period because most of these stations have reliable records only during this time. We first evaluated the visibility data against AERONET aerosol optical depth data, and found that only in dusty regions are the two moderately correlated. Correlation coefficients between visibility-derived variables and AERONET optical depths indicate a moderate correlation (0.47), consistent with capturing about 20% of the variability in optical depths. Two visibility-derived variables appear to compare the best with AERONET observations: the fraction of observations with visibility less than 5 km (VIS5) and the surface extinction (EXT). Regional trends show that in many dusty places, VIS5 and EXT are statistically significantly correlated with the Palmer drought severity index (based on precipitation and temperature) or surface wind speeds, consistent with dust temporal variability being largely driven by meteorology. This is especially true for North African and Chinese dust sources, but less true in the Middle East, Australia or South America, where there are not consistent patterns in the correlations. Climate indices such as El Nino or the North Atlantic Oscillation are not

  9. Effects of forest fires on visibility and air quality

    Science.gov (United States)

    Douglas G. Fox; Allen R. Riebau

    2009-01-01

    The U.S. Clean Air Act establishes the goal of preventing future and remedying existing visibility impairment in 156 Class I areas (national parks, wilderness areas, and wildlife refuges). A key element in implementing this goal is the Regional Haze Regulation (RHR). RHR is based on relating impaired visibility, using metrics of extinction (inverse megameters and/or ‘‘...

  10. Integrated TiO2 resonators for visible photonics

    CERN Document Server

    Choy, Jennifer T; Deotare, Parag B; Burgess, Ian B; Evans, Christopher C; Mazur, Eric; Loncar, Marko

    2011-01-01

    We demonstrate waveguide-coupled titanium dioxide (TiO2) racetrack resonators with loaded quality factors of 2x10^4 for the visible wavelengths. The structures were fabricated in sputtered TiO2 thin films on oxidized silicon substrates using standard top-down nanofabrication techniques, and passively probed in transmission measurements using a tunable red laser. Devices based on this material could serve as integrated optical elements as well as passive platforms for coupling to visible quantum emitters.

  11. [Qualitative Determination of Organic Vapour Using Violet and Visible Spectrum].

    Science.gov (United States)

    Jiang, Bo; Hu, Wen-zhong; Liu, Chang-jian; Zheng, Wei; Qi, Xiao-hui; Jiang, Ai-li; Wang, Yan-ying

    2015-12-01

    Vapours of organic matters were determined qualitatively employed with ultraviolet-visible absorption spectroscopy. Vapours of organic matters were detected using ultraviolet-visible spectrophotometer employing polyethylene film as medium, the ultraviolet and visible absorption spectra of vegetable oil vapours of soybean oil, sunflower seed oil, peanut oil, rapeseed oil, sesame oil, cotton seed oil, tung tree seed oil, and organic compound vapours of acetone, ethyl acetate, 95% ethanol, glacial acetic acid were obtained. Experimental results showed that spectra of the vegetable oil vapour and the organic compound vapour could be obtained commendably, since ultra violet and visible spectrum of polyethylene film could be deducted by spectrograph zero setting. Different kinds of vegetable oils could been distinguished commendably in the spectra since the λ(max), λ(min), number of absorption peak, position, inflection point in the ultra violet and visible spectra obtained from the vapours of the vegetable oils were all inconsistent, and the vapours of organic compounds were also determined perfectly. The method had a good reproducibility, the ultraviolet and visible absorption spectra of the vapours of sunflower seed oil in 10 times determination were absolutely the same. The experimental result indicated that polyethylene film as a kind of medium could be used for qualitative analysis of ultraviolet and visible absorption spectroscopy. The method for determination of the vapours of the vegetable oils and organic compounds had the peculiarities of fast speed analysis, well reproducibility, accuracy and reliability and low cost, and so on. Ultraviolet and visible absorption spectrum of organic vapour could provide feature information of material vapour and structural information of organic compound, and provide a novel test method for identifying vapour of compound and organic matter.

  12. Gouy phase and visibility in the double-slit experiment

    Energy Technology Data Exchange (ETDEWEB)

    Ferreira, C.J.S.; Marinho, L.S. [Departamento de Física, Universidade Federal do Piauí, Campus Ministro Petrônio Portela, CEP 64049-550, Teresina, PI (Brazil); Brazil, T.B. [Instituto de Física, Universidade de São Paulo, Caixa Postal 66318, 05315-970 São Paulo, SP (Brazil); Cabral, L.A. [Curso de Física, Universidade Federal do Tocantins, Caixa Postal 132, CEP 77804-970, Araguaína, TO (Brazil); Oliveira Jr, J.G.G. de [Departamento de Ciências Exatas e Tecnológicas, Universidade Estadual de Santa Cruz, Caixa Postal 45662-900, Ilhéus, BA (Brazil); Sampaio, M.D.R. [Departamento de Física, Instituto de Ciências Exatas, Universidade Federal de Minas Gerais, Caixa Postal 702, CEP 30161-970, Belo Horizonte, Minas Gerais (Brazil); Centre for Particle Theory CM310 Durham University - St. John’s College B6 (United States); Paz, I.G. da, E-mail: irismarpaz@ufpi.edu.br [Departamento de Física, Universidade Federal do Piauí, Campus Ministro Petrônio Portela, CEP 64049-550, Teresina, PI (Brazil)

    2015-11-15

    We study a matter wave double-slit experiment with unequal aperture widths in order to evaluate the effect of the Gouy phase on the visibility/predictability. While the predictability changes as one increases the width of one of the slits, the visibility receives a contribution from the Gouy phase at a specific point in the detection screen. Consequently such apparatus constitutes a simple device for measuring the Gouy phase of matter waves. We illustrate it numerically for neutrons.

  13. Visible Light Sensitization of Vinyl Azides by Transition Metal Photocatalysis

    Science.gov (United States)

    Farney, Elliot P.; Yoon, Tehshik P.

    2014-01-01

    Irradiation of vinyl and aryl azides with visible light in the presence of Ru photocatalysts results in the formation of reactive nitrenes, which can undergo a variety of C–N bond-forming reactions. The ability to use low-energy visible light instead of UV in the photochemical activation of azides avoids competitive photodecomposition processes that have long been a significant limitation on the synthetic utility of these reactions. PMID:24281908

  14. Visible fiber lasers excited by GaN laser diodes

    Science.gov (United States)

    Fujimoto, Yasushi; Nakanishi, Jun; Yamada, Tsuyoshi; Ishii, Osamu; Yamazaki, Masaaki

    2013-07-01

    This paper describes and discusses visible fiber lasers that are excited by GaN laser diodes. One of the attractive points of visible light is that the human eye is sensitive to it between 400 and 700 nm, and therefore we can see applications in display technology. Of course, many other applications exist. First, we briefly review previously developed visible lasers in the gas, liquid, and solid-state phases and describe the history of primary solid-state visible laser research by focusing on rare-earth doped fluoride media, including glasses and crystals, to clarify the differences and the merits of primary solid-state visible lasers. We also demonstrate over 1 W operation of a Pr:WPFG fiber laser due to high-power GaN laser diodes and low-loss optical fibers (0.1 dB/m) made by waterproof fluoride glasses. This new optical fiber glass is based on an AlF3 system fluoride glass, and its waterproof property is much better than the well known fluoride glass of ZBLAN. The configuration of primary visible fiber lasers promises highly efficient, cost-effective, and simple laser systems and will realize visible lasers with photon beam quality and quantity, such as high-power CW or tunable laser systems, compact ultraviolet lasers, and low-cost ultra-short pulse laser systems. We believe that primary visible fiber lasers, especially those excited by GaN laser diodes, will be effective tools for creating the next generation of research and light sources.

  15. Visibility analysis of point cloud in close range photogrammetry

    Science.gov (United States)

    Alsadik, B.; Gerke, M.; Vosselman, G.

    2014-05-01

    The ongoing development of advanced techniques in photogrammetry, computer vision (CV), robotics and laser scanning to efficiently acquire three dimensional geometric data offer new possibilities for many applications. The output of these techniques in the digital form is often a sparse or dense point cloud describing the 3D shape of an object. Viewing these point clouds in a computerized digital environment holds a difficulty in displaying the visible points of the object from a given viewpoint rather than the hidden points. This visibility problem is a major computer graphics topic and has been solved previously by using different mathematical techniques. However, to our knowledge, there is no study of presenting the different visibility analysis methods of point clouds from a photogrammetric viewpoint. The visibility approaches, which are surface based or voxel based, and the hidden point removal (HPR) will be presented. Three different problems in close range photogrammetry are presented: camera network design, guidance with synthetic images and the gap detection in a point cloud. The latter one introduces also a new concept of gap classification. Every problem utilizes a different visibility technique to show the valuable effect of visibility analysis on the final solution.

  16. Disease, communication, and the ethics of (in) visibility.

    Science.gov (United States)

    Pietrzak-Franger, Monika Monika; Holmes, Martha Stoddard

    2014-12-01

    As the recent Ebola outbreak demonstrates, visibility is central to the shaping of political, medical, and socioeconomic decisions. The symposium in this issue of the Journal of Bioethical Inquiry explores the uneasy relationship between the necessity of making diseases visible, the mechanisms of legal and visual censorship, and the overall ethics of viewing and spectatorship, including the effects of media visibility on the perception of particular "marked" bodies. Scholarship across the disciplines of communication, anthropology, gender studies, and visual studies, as well as a photographer's visual essay and memorial reflection, throw light on various strategies of visualization and (de)legitimation and link these to broader socioeconomic concerns. Questions of the ethics of spectatorship, such as how to evoke empathy in the representation of individuals' suffering without perpetuating social and economic inequalities, are explored in individual, (trans-)national, and global contexts, demonstrating how disease (in)visibility intersects with a complex nexus of health, sexuality, and global/national politics. A sensible management of visibility--an "ecology of the visible"--can be productive of more viable ways of individual and collective engagement with those who suffer.

  17. Multiview Visibility Estimation for Image-Based Modeling

    Institute of Scientific and Technical Information of China (English)

    Liu-Xin Zhang; Ming-Tao Pei; Yun-De Jia

    2011-01-01

    In this paper,we investigate the problem of determining regions in 3D scene visible to some given viewpoints when obstacles are present in the scene.We assume that the obstacles are composed of some opaque objects with closed surfaces.The problem is formulated in an implicit framework where the obstacles are represented by a level set function.The visible and invisible regions of the given viewpoints are determined through an efficient implicit ray tracing technique.As an extension of our approach,we apply the multiview visibility estimation to an image-based modeling technique.The unknown scene geometry and multiview visibility information are incorporated into a variational energy functional.By minimizing the energy functional,the true scene geometry as well as the accurate visibility information of the multiple views can be recovered from a number of scene images.This makes it feasible to handle the visibility problem of multiple views by our approach when the true scene geometry is unknown.

  18. Quantitative Model for Supply Chain Visibility: Process Capability Perspective

    Directory of Open Access Journals (Sweden)

    Youngsu Lee

    2016-01-01

    Full Text Available Currently, the intensity of enterprise competition has increased as a result of a greater diversity of customer needs as well as the persistence of a long-term recession. The results of competition are becoming severe enough to determine the survival of company. To survive global competition, each firm must focus on achieving innovation excellence and operational excellence as core competency for sustainable competitive advantage. Supply chain management is now regarded as one of the most effective innovation initiatives to achieve operational excellence, and its importance has become ever more apparent. However, few companies effectively manage their supply chains, and the greatest difficulty is in achieving supply chain visibility. Many companies still suffer from a lack of visibility, and in spite of extensive research and the availability of modern technologies, the concepts and quantification methods to increase supply chain visibility are still ambiguous. Based on the extant researches in supply chain visibility, this study proposes an extended visibility concept focusing on a process capability perspective and suggests a more quantitative model using Z score in Six Sigma methodology to evaluate and improve the level of supply chain visibility.

  19. Distance and Visibility: Two Systems in Hausa Deixis

    Directory of Open Access Journals (Sweden)

    Abdoulaye, Mahamane L.

    2008-01-01

    Full Text Available The current standard account of Hausa deixis claims that Hausa has a linear person-based system with the following four locative adverbs and their interpretations: nân 'here', nan 'there near you', cân 'there away from you and me', and can 'over there away from you and me'. This paper shows that in fact one may need two separate deictic systems for Hausa to account for all relevant data. The first system is based on distance with a primary proximal vs. distal contrast. The distance system however also embeds a person subsystem, with one adverb in particular referring to the hearer (second person position. The second deictic system in Hausa is based on visibility, with a primary contrast between an area comfortably visible and an area visible only with some difficulties. Indeed, in the visibility system, five adverbs range the entire visible area in front of the speaker, from the foreground up to the extreme visible area at the horizon.

  20. A new visibility measurement system based on a black target and a comparative trial with visibility instruments

    Science.gov (United States)

    Tang, Fanjie; Ma, Shuqing; Yang, Ling; Du, Chuanyao; Tang, Yingjie

    2016-10-01

    According to Koschmieder's law, a mathematical model of contrast between a single black object and the sky background is established. Based on this principle, we built a black target visiometer system using a photograph of a black object taken with an industrial camera, that has a relatively simple structure and automated operation. In this study, three commercial visibility instruments-a forward scatter meter (CJB-3A) and two atmospheric transmission meters (LT31, VM100)-were compared to the black target visiometer system. Our results show that, within visibility ranges of up to 10 km, 1) all of the instruments agree well at low visibility and agree poorly at a visibility exceeding 5 km; 2) the forward scattering instrument has high bias at low visibility because particle absorption is not included; and 3) the best agreement with the black target method was obtained with the simple transmissometer rather than the forward scatter instrument or the hybrid transmissometer for a visibility range of up to 10 km.

  1. Workforce utilization of visible and linguistic minorities in Canadian nursing.

    Science.gov (United States)

    Premji, Stephanie; Etowa, Josephine B

    2014-01-01

    Aim  This study seeks to develop a diversity profile of the nursing workforce in Canada and its major cities. Background  There is ample evidence of ethnic and linguistic segregation in the Canadian labour market. However, it is unknown if there is equitable representation of visible and linguistic minorities in nursing professions. Methods  We cross-tabulated aggregate data from Statistics Canada's 2006 Census. Analyses examined the distribution of visible and linguistic minorities, including visible minority sub-groups, among health managers, head nurses, registered nurses, licensed nurses and nurse aides for Canada and major cities as well as by gender. Results  In Canada and its major cities, a pyramidal structure was found whereby visible and linguistic minorities, women in particular, were under-represented in managerial positions and over-represented in lower ranking positions. Blacks and Filipinos were generally well represented across nursing professions; however, other visible minority sub-groups lacked representation. Conclusions  Diversity initiatives at all levels can play a role in promoting better access to and quality of care for minority populations through the increased cultural and linguistic competence of care providers and organizations. Implications for Nursing Management  Efforts to increase diversity in nursing need to be accompanied by commitment and resources to effectively manage diversity within organizations. © 2012 John Wiley & Sons Ltd.

  2. Inequality and visibility of wealth in experimental social networks.

    Science.gov (United States)

    Nishi, Akihiro; Shirado, Hirokazu; Rand, David G; Christakis, Nicholas A

    2015-10-15

    Humans prefer relatively equal distributions of resources, yet societies have varying degrees of economic inequality. To investigate some of the possible determinants and consequences of inequality, here we perform experiments involving a networked public goods game in which subjects interact and gain or lose wealth. Subjects (n = 1,462) were randomly assigned to have higher or lower initial endowments, and were embedded within social networks with three levels of economic inequality (Gini coefficient = 0.0, 0.2, and 0.4). In addition, we manipulated the visibility of the wealth of network neighbours. We show that wealth visibility facilitates the downstream consequences of initial inequality-in initially more unequal situations, wealth visibility leads to greater inequality than when wealth is invisible. This result reflects a heterogeneous response to visibility in richer versus poorer subjects. We also find that making wealth visible has adverse welfare consequences, yielding lower levels of overall cooperation, inter-connectedness, and wealth. High initial levels of economic inequality alone, however, have relatively few deleterious welfare effects.

  3. Robust Adaptive Photon Tracing using Photon Path Visibility

    DEFF Research Database (Denmark)

    Hachisuka, Toshiya; Jensen, Henrik Wann

    2011-01-01

    We present a new adaptive photon tracing algorithm which can handle illumination settings that are considered difficult for photon tracing approaches such as outdoor scenes, close-ups of a small part of an illuminated region, and illumination coming through a small gap. The key contribution in our...... algorithm is the use of visibility of photon path as the importance function which ensures that our sampling algorithm focuses on paths that are visible from the given viewpoint. Our sampling algorithm builds on two recent developments in Markov chain Monte Carlo methods: adaptive Markov chain sampling...... and replica exchange. Using these techniques, each photon path is adaptively mutated and it explores the sampling space efficiently without being stuck at a local peak of the importance function. We have implemented this sampling approach in the progressive photon mapping algorithm which provides visibility...

  4. Time reversibility from visibility graphs of non-stationary processes

    CERN Document Server

    Lacasa, Lucas

    2015-01-01

    Visibility algorithms are a family of methods to map time series into networks, with the aim of describing the structure of time series and their underlying dynamical properties in graph-theoretical terms. Here we explore some properties of both natural and horizontal visibility graphs associated to several non-stationary processes, and we pay particular attention to their capacity to assess time irreversibility. Non-stationary signals are (infinitely) irreversible by definition (independently of whether the process is Markovian or producing entropy at a positive rate), and thus the link between entropy production and time series irreversibility has only been explored in non-equilibrium stationary states. Here we show that the visibility formalism naturally induces a new working definition of time irreversibility, which allows to quantify several degrees of irreversibility for stationary and non-stationary series, yielding finite values that can be used to efficiently assess the presence of memory and off-equ...

  5. Dark/Visible Parallel Universes and Big Bang Nucleosynthesis

    CERN Document Server

    Bertulani, C A; Fuqua, J; Hussein, M S; Oliveira, O; de Paula, W

    2012-01-01

    We develop a model for visible matter-dark matter interaction based on the exchange of a massive gray boson called herein the Mulato. Our model hinges on the assumption that all known particles in the visible matter have their counterparts in the dark matter. We postulate six families of particles five of which are dark. This leads to the unavoidable postulation of six parallel worlds, the visible one and five invisible worlds. A close study of big bang nucleosynthesis (BBN), baryon asymmetries, cosmic microwave background (CMB) bounds, galaxy dynamics, together with the Standard Model assumptions, help us to set a limit on the mass and width of the new gauge boson. Modification of the statistics underlying the kinetic energy distribution of particles during the BBN is also discussed. The changes in reaction rates during the BBN due to a departure from the Debye-Hueckel electron screening model is also investigated.

  6. Dark/visible parallel universes and Big Bang nucleosynthesis

    Energy Technology Data Exchange (ETDEWEB)

    Bertulani, C. A.; Frederico, T.; Fuqua, J.; Hussein, M. S.; Oliveira, O.; Paula, W. de [Department of Physics and Astronomy, Texas A and M University-Commerce, Commerce TX 75429 (United States); Departamento de Fisica, Instituto Tecnologico de Aeronautica, DCTA 12.228-900, Sao Jose dos Campos, SP (Brazil); Department of Physics and Astronomy, Texas A and M University-Commerce, Commerce TX 75429 (United States); Instituto de Fisica, Universidade de Sao Paulo, Caixa Postal 66318, 05314-970 Sao Paulo, SP (Brazil); Departamento de Fisica, Instituto Tecnologico de Aeronautica, DCTA 12.228-900, Sao Jose dos Campos, SP, Brazil and Departamento de Fisica, Universidade de Coimbra, 3004-516 Coimbra (Portugal); Departamento de Fisica, Instituto Tecnologico de Aeronautica, DCTA 12.228-900, Sao Jose dos Campos, SP (Brazil)

    2012-11-20

    We develop a model for visible matter-dark matter interaction based on the exchange of a massive gray boson called herein the Mulato. Our model hinges on the assumption that all known particles in the visible matter have their counterparts in the dark matter. We postulate six families of particles five of which are dark. This leads to the unavoidable postulation of six parallel worlds, the visible one and five invisible worlds. A close study of big bang nucleosynthesis (BBN), baryon asymmetries, cosmic microwave background (CMB) bounds, galaxy dynamics, together with the Standard Model assumptions, help us to set a limit on the mass and width of the new gauge boson. Modification of the statistics underlying the kinetic energy distribution of particles during the BBN is also discussed. The changes in reaction rates during the BBN due to a departure from the Debye-Hueckel electron screening model is also investigated.

  7. Young children's tool innovation across culture: Affordance visibility matters.

    Science.gov (United States)

    Neldner, Karri; Mushin, Ilana; Nielsen, Mark

    2017-11-01

    Young children typically demonstrate low rates of tool innovation. However, previous studies have limited children's performance by presenting tools with opaque affordances. In an attempt to scaffold children's understanding of what constitutes an appropriate tool within an innovation task we compared tools in which the focal affordance was visible to those in which it was opaque. To evaluate possible cultural specificity, data collection was undertaken in a Western urban population and a remote Indigenous community. As expected affordance visibility altered innovation rates: young children were more likely to innovate on a tool that had visible affordances than one with concealed affordances. Furthermore, innovation rates were higher than those reported in previous innovation studies. Cultural background did not affect children's rates of tool innovation. It is suggested that new methods for testing tool innovation in children must be developed in order to broaden our knowledge of young children's tool innovation capabilities. Copyright © 2017 Elsevier B.V. All rights reserved.

  8. Anderson localisation of visible light on a nanophotonic chip

    CERN Document Server

    Crane, Tom; Sapienza, Luca

    2016-01-01

    Controlling the propagation of visible light on a chip is of tremendous interest in research areas such as energy harvesting, imaging, sensing and biology. Technological advances allow us to control light at the nanoscale and to strongly enhance the light-matter interaction in highly engineered devices. However, compared to state-of-the-art two-dimensional optical cavities operating at longer wavelengths, the quality factor of on-chip visible light confinement is several orders of magnitude lower. Our approach makes use of fabrication imperfections to trap light: we demonstrate, for the first time, Anderson localisation of visible light on a chip. Remarkably, compared to quality factors of engineered cavities, disorder-induced localisation proves to be more efficient in trapping light than highly engineered devices, thus reversing the trend observed so far. We measure light-confinement quality factors as high as 7600 and, by implementing a sensitive imaging technique, we directly visualise the localised modes...

  9. [Implications of the visibility in professional nursing practices].

    Science.gov (United States)

    Avila, Liziani Iturriet; da Silveira, Rosemary Silva; Lunardi, Valéria Lerch; Fernandes, Geani Farias Machado; Mancia, Joel Rolim; da Silveira, Juliana Teixeira

    2013-09-01

    Nursing construction image is permeated by historical socioeconomic and cultural aspects. This theme aims to understand the perception of nurses regarding the visibility of nursing staff's daily work. This qualitative research is exploratory, with 30 nurses at a university hospital in southern Brazil. The data was collected from July to October 2012, through semi-structured interviews and submitted for a discursive textual analysis. The results show that nursing visibility is related to a professional historical trajectory, to an absence of recognition of the scientific aspect of Nursing, to erroneous placement in the media, to improper behavior towards the staff and also to work overload. Thus, the demystification of nursing's image includes greater media visibility, conducting personnel marketing, appropriate behavior in front of health staff and professional demonstrations of autonomy, challenges that must be overcome by nursing.

  10. Development of Visible Light-Responsive Sensitized Photocatalysts

    Directory of Open Access Journals (Sweden)

    Donghua Pei

    2012-01-01

    Full Text Available The paper presents a review of studies about the visible-light-promoted photodegradation of the contaminants and energy conversion with sensitized photocatalysts. Herein we studied mechanism, physical properties, and synergism effect of the sensitized photocatalysts as well as the method for enhancing the photosensitized effect. According to the reported studies in the literature, inorganic sensitizers, organic dyes, and coordination metal complexes were very effective sensitizers that were studied mostly, of which organic dyes photosensitization is the most widely studied modified method. Photosensitization is an important way to extend the excitation wavelength to the visible range, and therefore sensitized photocatalysts play an important role in the development of visible light-responsive photocatalysts for future industrialized applications. This paper mainly describes the types, modification, photocatalytic performance, application, and the developments of photosensitization for environmental application.

  11. MR-Visible Lipids and the Tumor Microenvironment

    Science.gov (United States)

    Delikatny, E. James; Chawla, Sanjeev; Leung, Daniel-Joseph; Poptani, Harish

    2013-01-01

    MR-visible lipids or mobile lipids are defined as lipids that are observable using proton magnetic resonance spectroscopy in cells and in tissues. These MR-visible lipids are composed of triglycerides and cholesterol esters that accumulate in intracellular neutral lipid droplets, where their MR visibility is conferred as a result of the increased molecular motion available in this unique physical environment. This review will discuss factors that lead to the biogenesis of MR-visible lipids in cancer cells and in other cell types such as immune cells and fibroblasts. We focus on the accumulations of mobile lipids that are inducible in cultured cells by a number of stresses, including culture conditions and in response to activating stimuli or apoptotic cell death induced by anticancer drugs. This is compared with animal tumor models, where increases in mobile lipids are observed in response to chemo and radiotherapy, and to human tumors where mobile lipids are observed predominantly in high-grade brain tumors and in regions of necrosis. Conducive conditions for mobile lipid formation in the tumor microenvironment will be discussed including low pH, oxygen availability and the presence of inflammatory cells. It is concluded that MR-visible lipids appear in cancer cells and human tumors as a stress response. Mobile lipids stored as neutral lipid droplets may play a role in detoxification of the cell or act as an alternate energy source, especially in cancer cells, which often grow in ischemic/hypoxic environments. The role of MR-visible lipids in cancer diagnosis and assessment of treatment response both in animal models of cancer as well as human brain tumors will also be discussed. Although technical limitations exist in the accurate detection of intratumoral mobile lipids, early increases in mobile lipids after therapeutic interventions may be used as a potential biomarker for assessing treatment response in cancer. PMID:21538631

  12. Switching Diarylethenes Reliably in Both Directions with Visible Light.

    Science.gov (United States)

    Fredrich, Sebastian; Göstl, Robert; Herder, Martin; Grubert, Lutz; Hecht, Stefan

    2016-01-18

    A diarylethene photoswitch was covalently connected to two small triplet sensitizer moieties in a conjugated and nonconjugated fashion and the photochromic performance of the resulting compounds was investigated. In comparison with the parent diarylethene (without sensitizers) and one featuring saturated linkages, the conjugated photoswitch offers superior fatigue resistance upon visible-light excitation due to effective triplet energy transfer from the biacetyl termini to the diarylethene core. Our design makes it possible to switch diarylethenes with visible light in both directions in a highly efficient and robust fashion based on extending π-conjugation and by-product-free ring-closure via the triplet manifold.

  13. Visibility of gingiva - An important determinant for an esthetic smile

    Directory of Open Access Journals (Sweden)

    Shipra Sepolia

    2014-01-01

    Full Text Available Background: Need for having better esthetics is the new emerging trend seen in patients′ demands and expectations. Various periodontal procedures including the mucogingival procedures have been designed to enhance the esthetics. The amount of gingival display of the patient is also an important parameter while considering the esthetics of the patient. Till date, very few studies have been done in which the amount of gingival visibility have been determined. So, the aim of this study was to evaluate the amount of visibility of gingiva during natural smile and forced smile in the patients visiting Himachal Dental College and Hospital. Materials and Methods: A total of 400 patients (242 females and 158 males, aged between 18 to 49 years, attending the outpatient department of Himachal Dental College, were included in this study. Patients were divided into two groups according to age and gender. Clinical photographs of the patients were taken and analyzed according to the following classification: (1 Very high smile line that is more than 2 mm of marginal gingiva visible or more than 2 mm apical to the cementoenamel junction visible for the reduced but healthy periodontium, (2 high smile line that is between 0 and 2 mm of marginal gingiva visible or between 0 and 2 mm apical to the cementoenamel junction visible for the reduced but healthy periodontium, (3 average smile line in which only gingival embrasures are visible, (4 low smile line in which gingival embrasures and cementoenamel junction not visible. Examination of the gingiva was done for both natural smile and forced smile. Results: During smile analysis, the following results were revealed for Natural smile and forced smile. Natural smile analysis revealed following: C1: 1%, C2: 6%, C3: 43.50% and C4 was 49.50%. Forced smile analysis revealed the following: C1: 1%, C2: 15.50%, C3: 59% and C4: 24.50%. Conclusions: Excessive gingival display is an esthetic concern both to the patient and

  14. An Advanced Atmospheric Dispersion Corrector: The Magellan Visible AO Camera

    OpenAIRE

    Kopon, Derek; Close, Laird M.; Gasho, Victor

    2010-01-01

    In addition to the BLINC/MIRAC IR science instruments, the Magellan adaptive secondary AO system will have an EEV CCD47 that can be used both for visible AO science and as a wide-field acquisition camera. The effects of atmospheric dispersion on the elongation of the diffraction limited Magellan adaptive optics system point spread function (PSF) are significant in the near IR. This elongation becomes particularly egregious at visible wavelengths, culminating in a PSF that is 2000\\{mu}m long i...

  15. Predicting the visibility of dynamic DCT distortions in natural videos

    Science.gov (United States)

    Evert, Jeremy P.; Alam, Md Mushfiqul; Chandler, Damon M.

    2015-09-01

    Compression has enabled years of exponential growth in global video consumption, providing video everywhere, with few perceptible artifacts. Automated Video Quality Assessment (VQA) is an enabler of compression. We present data showing video contrast affects on artifact visibility. Based on our data, we propose a contrast-gain-control VQA algorithm, with target spatiotemporal property weighting, and using our data to tune existing VQA algorithms for improved artifact threshold predictions. This paper provides much needed data on natural video mask contrast and artifact visibility, and provides important insights for how VQA algorithms can be improved to better predict video quality in the high-quality regime.

  16. Infrared and visible image fusion using NSCT and GGD

    Science.gov (United States)

    Zhang, Xiuqiong; Liu, Cuiyin; Men, Tao; Qin, Hongyin; Wang, Mingrong

    2011-06-01

    In order to fuse the visible and infrared images captured in low visibility conditions, a method based on nonsubsampled contourlet transform (NSCT) and generalized Gaussian distribution (GGD) is proposed in this paper. The statistical character of the directional coefficients decomposed by NSCT meet the GGD. So, the coefficients are estimated using absolute moment estimation in local neighbor in directional coefficients. The estimated scale parameter is used to measure the saliency and compute the weight. The fused coefficients are obtained by the weighted average and are reconstructed the final fused image. Compared to the DWT and SIDWT, the proposed method has b superior fusion performance.

  17. Visible light metasurfaces based on gallium nitride high contrast gratings

    Science.gov (United States)

    Wang, Zhenhai; He, Shumin; Liu, Qifa; Wang, Wei

    2016-05-01

    We propose visible-light metasurfaces (VLMs) capable of serving as lens and beam deflecting element based on gallium nitride (GaN) high contrast gratings (HCGs). By precisely manipulating the wavefront of the transmitted light, we theoretically demonstrate an HCG focusing lens with transmissivity of 86.3%, and a VLM with beam deflection angle of 6.09° and transmissivity as high as 91.4%. The proposed all-dielectric metasurfaces are promising for GaN-based visible light-emitting diodes (LEDs), which would be robust and versatile for controlling the output light propagation and polarization, as well as enhancing the extraction efficiency of the LEDs.

  18. Perceptions of a photograph of a woman with visible piercings.

    Science.gov (United States)

    Martino, Sara

    2008-08-01

    To examine perceptions of people with visible piercings 105 undergraduate students from four different courses on campus (85 women, 20 men; M age=20.0 yr., SD=3.4) were randomly assigned to rate a photograph of a women with or without piercings on her eyebrow, ear, lip, and nose on 13 characteristics. Analysis indicated the model with visible piercings was rated less religious and more creative, artistic, and mysterious. These findings differ from previous findings on perception of tattoos. Implications and directions for research with different age groups are discussed.

  19. High visibility gravimetry with a Bose-Einstein condensate

    CERN Document Server

    Debs, J E; Barter, T H; Döring, D; Dennis, G R; McDonald, G; Robins, N P; Close, J D

    2010-01-01

    We present results from an atomic gravimeter using a Bose-Einstein condensate with fringe visibility up to 85%. A direct comparison with a thermal state displays a significant increase in visibility for a condensed source. We do not observe any detrimental effects of atom-atom interactions, provided the cloud is allowed to reach the ballistic free-expansion regime. By increasing the space-time area enclosed by our interferometer using large-momentum-transfer beamsplitters, we achieve a precision of 17 ppm in a measurement of the local acceleration due to gravity.

  20. Implementasi Visible Light Communication (VLC Pada Sistem Komunikasi

    Directory of Open Access Journals (Sweden)

    ARSYAD RAMADHAN DARLIS

    2017-06-01

    Full Text Available Abstrak Perkembangan teknologi telah menunjukkan peningkatan yang cukup signifikan, terutama untuk bidang komunikasi. Hal ini terbukti dengan banyaknya media komunikasi baik itu nirkabel dan kabel. Pada penelitian ini dimanfaatkan cahaya tampak sebagai media dalam sistem komunikasi, dimana selama ini cahaya hanya digunakan sebagai penerangan saja. Visible Light Communication (VLC adalah sebuah teknologi komunikasi yang memanfaatkan pancaran cahaya tampak dari lampu pada sistem komunikasi. Sistem komunikasi visible light ini terdiri dari pemancar dan penerima. Pemancar terdiri dari Light Emitting Dioda, audio transformator dan baterai, dan pada penerima terdiri dari solar cell dan photodioda, amplifier dan catu daya. Hal-hal yang dapat mempengaruhi hasil output sistem komunikasi adalah jarak, terang cahaya lampu pemancar dan cahaya luar. Pada penelitian ini, komunikasi menggunakan VLC dapat dilakukan pada jarak pengiriman data sebesar 2,5 m dan dengan range frekuensi 600 Hz sampai dengan 45 kHz dimana data dapat disalurkan dengan baik. Kata kunci: Visible light, Sistem komunikasi, Light Emitting Dioda, solar cell, photodioda. Abstract Technological developments have shown a significant increase, especially in the field of communication. This is proved by the many communications media using both wireless and wired. This study utilized the visible light as a medium of communication system, which has been used as an illumination light only. Visible Light Communication (VLC is a communication technology which utilize visible light emitted from the lamp in the communication system. The visible light communication system consists of a transmitter and receiver. The transmitter consists of a Light Emitting Diode, audio transformer and battery, and the receiver consists of a solar cell and a photodiode, amplifier and power supply. Things that can affect the output of the communication system is the distance, bright light and outdoor light. In the research

  1. Highly luminescent S, N co-doped graphene quantum dots with broad visible absorption bands for visible light photocatalysts

    Science.gov (United States)

    Qu, Dan; Zheng, Min; Du, Peng; Zhou, Yue; Zhang, Ligong; Li, Di; Tan, Huaqiao; Zhao, Zhao; Xie, Zhigang; Sun, Zaicheng

    2013-11-01

    A facile hydrothermal synthesis route to N and S, N co-doped graphene quantum dots (GQDs) was developed by using citric acid as the C source and urea or thiourea as N and S sources. Both N and S, N doped GQDs showed high quantum yield (78% and 71%), excitation independent under excitation of 340-400 nm and single exponential decay under UV excitation. A broad absorption band in the visible region appeared in S, N co-doped GQDs due to doping with sulfur, which alters the surface state of GQDs. However, S, N co-doped GQDs show different color emission under excitation of 420-520 nm due to their absorption in the visible region. The excellent photocatalytic performance of the S, N co-doped GQD/TiO2 composites was demonstrated by degradation of rhodamine B under visible light. The apparent rate of S, N:GQD/TiO2 is 3 and 10 times higher than that of N:GQD/TiO2 and P25 TiO2 under visible light irradiation, respectively.A facile hydrothermal synthesis route to N and S, N co-doped graphene quantum dots (GQDs) was developed by using citric acid as the C source and urea or thiourea as N and S sources. Both N and S, N doped GQDs showed high quantum yield (78% and 71%), excitation independent under excitation of 340-400 nm and single exponential decay under UV excitation. A broad absorption band in the visible region appeared in S, N co-doped GQDs due to doping with sulfur, which alters the surface state of GQDs. However, S, N co-doped GQDs show different color emission under excitation of 420-520 nm due to their absorption in the visible region. The excellent photocatalytic performance of the S, N co-doped GQD/TiO2 composites was demonstrated by degradation of rhodamine B under visible light. The apparent rate of S, N:GQD/TiO2 is 3 and 10 times higher than that of N:GQD/TiO2 and P25 TiO2 under visible light irradiation, respectively. Electronic supplementary information (ESI) available: More XPS and UV-Vis spectra. See DOI: 10.1039/c3nr04402e

  2. 40 CFR 49.124 - Rule for limiting visible emissions.

    Science.gov (United States)

    2010-07-01

    ... smoke houses, sweat houses or lodges, smudge pots, furnaces and boilers used exclusively to heat... water, such as steam, is the only reason for the failure of an air pollution source to meet the 20% opacity limit. (3) The visible emissions from an oil-fired boiler or solid fuel-fired boiler...

  3. Pangenesis: a common origin for visible and dark matter

    OpenAIRE

    Volkas, Raymond R.

    2012-01-01

    The similar mass densities observed for visible and dark matter in the present-day universe suggest a common origin for both. A scheme called "pangenesis" for realising this using the Affleck-Dine mechanism in a baryon-symmetric universe is presented in this talk.

  4. Visibility Estimation for the CHARA/JouFLU Exozodi Survey

    Science.gov (United States)

    Nuñez, Paul D.; ten Brummelaar, Theo; Mennesson, Bertrand; Scott, Nicholas J.

    2017-02-01

    We discuss the estimation of the interferometric visibility (fringe contrast) for the Exozodi survey conducted at the CHARA array with the JouFLU beam combiner. We investigate the use of the statistical median to estimate the uncalibrated visibility from an ensemble of fringe exposures. Under a broad range of operating conditions, numerical simulations indicate that this estimator has a smaller bias compared with other estimators. We also propose an improved method for calibrating visibilities, which not only takes into account the time interval between observations of calibrators and science targets, but also the uncertainties of the calibrators’ raw visibilities. We test our methods with data corresponding to stars that do not display the exozodi phenomenon. The results of our tests show that the proposed method yields smaller biases and errors. The relative reduction in bias and error is generally modest, but can be as high as ∼ 20 % {--}40 % for the brightest stars of the CHARA data and statistically significant at the 95% confidence level (CL).

  5. 40 CFR 52.29 - Visibility long-term strategies.

    Science.gov (United States)

    2010-07-01

    ...-term strategy. (1) A long-term strategy is a 10- to 15-year plan for making reasonable progress toward... every 3 years from November 24, 1987. (3) During the long-term strategy review process, the... 40 Protection of Environment 3 2010-07-01 2010-07-01 false Visibility long-term strategies. 52.29...

  6. Seeing elements by visible-light digital camera

    Science.gov (United States)

    Zhao, Wenyang; Sakurai, Kenji

    2017-03-01

    A visible-light digital camera is used for taking ordinary photos, but with new operational procedures it can measure the photon energy in the X-ray wavelength region and therefore see chemical elements. This report describes how one can observe X-rays by means of such an ordinary camera - The front cover of the camera is replaced by an opaque X-ray window to block visible light and to allow X-rays to pass; the camera takes many snap shots (called single-photon-counting mode) to record every photon event individually; an integrated-filtering method is newly proposed to correctly retrieve the energy of photons from raw camera images. Finally, the retrieved X-ray energy-dispersive spectra show fine energy resolution and great accuracy in energy calibration, and therefore the visible-light digital camera can be applied to routine X-ray fluorescence measurement to analyze the element composition in unknown samples. In addition, the visible-light digital camera is promising in that it could serve as a position sensitive X-ray energy detector. It may become able to measure the element map or chemical diffusion in a multi-element system if it is fabricated with external X-ray optic devices. Owing to the camera’s low expense and fine pixel size, the present method will be widely applied to the analysis of chemical elements as well as imaging.

  7. Assessing Visibility of Individual Transmission Errors in Networked Video

    DEFF Research Database (Denmark)

    Korhonen, Jari; Mantel, Claire

    2016-01-01

    could benefit from information about subjective visibility of individual packet losses; for example, computational resources could be directed more efficiently to unequal error protection and concealment by focusing in the visually most disturbing artifacts. In this paper, we present a novel subjective...

  8. Visibility and anonymity effects on attraction and group cohesiveness

    NARCIS (Netherlands)

    Lea, Martin; Spears, Russell; Watt, Susan E.

    2007-01-01

    This study investigated attraction and group cohesiveness under different visibility and anonymity conditions for social categories that differed in their capacity to be visually cued. Using computer-mediated communication in 36 mixed gender (visually cued category) and nationality (non-visually

  9. Development and validation of satellite based estimates of surface visibility

    Science.gov (United States)

    Brunner, J.; Pierce, R. B.; Lenzen, A.

    2015-10-01

    A satellite based surface visibility retrieval has been developed using Moderate Resolution Imaging Spectroradiometer (MODIS) measurements as a proxy for Advanced Baseline Imager (ABI) data from the next generation of Geostationary Operational Environmental Satellites (GOES-R). The retrieval uses a multiple linear regression approach to relate satellite aerosol optical depth, fog/low cloud probability and thickness retrievals, and meteorological variables from numerical weather prediction forecasts to National Weather Service Automated Surface Observing System (ASOS) surface visibility measurements. Validation using independent ASOS measurements shows that the GOES-R ABI surface visibility retrieval (V) has an overall success rate of 64.5% for classifying Clear (V ≥ 30 km), Moderate (10 km ≤ V skill during June through September, when Heidke skill scores are between 0.2 and 0.4. We demonstrate that the aerosol (clear sky) component of the GOES-R ABI visibility retrieval can be used to augment measurements from the United States Environmental Protection Agency (EPA) and National Park Service (NPS) Interagency Monitoring of Protected Visual Environments (IMPROVE) network, and provide useful information to the regional planning offices responsible for developing mitigation strategies required under the EPA's Regional Haze Rule, particularly during regional haze events associated with smoke from wildfires.

  10. Developing Tools for Undergraduate Spectroscopy: An Inexpensive Visible Light Spectrometer

    Science.gov (United States)

    Vanderveen, Jesse R.; Martin, Brian; Ooms, Kristopher J.

    2013-01-01

    The design and implementation of an inexpensive, high-resolution Littrow-type visible light spectrometer is presented. The instrument is built from low-cost materials and interfaced with the program RSpec for real-time spectral analysis, making it useful for classroom and laboratory exercises. Using a diffraction grating ruled at 1200 lines/mm and…

  11. Error Reduction for Visible Watermarking in Still Images

    Institute of Scientific and Technical Information of China (English)

    LjubisaRadunovic; 王朔中; 等

    2002-01-01

    Different digital watermarking techniques and their applications are briefly reviewed.Solution to a practical problem with visible image marking is presented,together with experimental results and discussion.Main focusis on reduction of error caused by the mark addition and subtraction.Image classification based on its mean gray level and adjustment of out-of-range gray levels are implemented.

  12. A titanium nitride based metamaterial for applications in the visible

    DEFF Research Database (Denmark)

    Naik, Gururaj V.; Saha, Bivas; Liu, Jing

    2013-01-01

    Epitaxially grown TiN/Al0.6Sc0.4N superlattice behaves as a hyperbolic metamaterial (HMM) in the visible range. Since HMMs enhance photonic-density-of-states and reduce lifetime of an emitter, we observed nine times decrease in lifetime of a dye molecule placed close to this HMM. © 2013 The Optical...

  13. Visibility and anonymity effects on attraction and group cohesiveness

    NARCIS (Netherlands)

    Lea, Martin; Spears, Russell; Watt, Susan E.

    2007-01-01

    This study investigated attraction and group cohesiveness under different visibility and anonymity conditions for social categories that differed in their capacity to be visually cued. Using computer-mediated communication in 36 mixed gender (visually cued category) and nationality (non-visually cue

  14. A Review on Visible Light Active Perovskite-Based Photocatalysts

    Directory of Open Access Journals (Sweden)

    Pushkar Kanhere

    2014-12-01

    Full Text Available Perovskite-based photocatalysts are of significant interest in the field of photocatalysis. To date, several perovskite material systems have been developed and their applications in visible light photocatalysis studied. This article provides a review of the visible light (λ > 400 nm active perovskite-based photocatalyst systems. The materials systems are classified by the B site cations and their crystal structure, optical properties, electronic structure, and photocatalytic performance are reviewed in detail. Titanates, tantalates, niobates, vanadates, and ferrites form important photocatalysts which show promise in visible light-driven photoreactions. Along with simple perovskite (ABO3 structures, development of double/complex perovskites that are active under visible light is also reviewed. Various strategies employed for enhancing the photocatalytic performance have been discussed, emphasizing the specific advantages and challenges offered by perovskite-based photocatalysts. This review provides a broad overview of the perovskite photocatalysts, summarizing the current state of the work and offering useful insights for their future development.

  15. CMOS-compatible LVOF-based visible microspectrometer

    NARCIS (Netherlands)

    Emadi, A.; Wu, H.; De Graaf, G.; Wolffenbuttel, R.F.

    2010-01-01

    This paper reports on a CMOS-Compatible Linear Variable Optical Filter (LVOF) visible micro-spectrometer. The CMOS-compatible post process for fabrication of the LVOF has been used for integration of the LVOF with a CMOS chip containing a 128-element photodiode array and readout circuitry. Fabricati

  16. Using Polarization features of visible light for automatic landmine detection

    NARCIS (Netherlands)

    Jong, W. de; Schavemaker, J.G.M.

    2007-01-01

    This chapter describes the usage of polarization features of visible light for automatic landmine detection. The first section gives an introduction to land-mine detection and the usage of camera systems. In section 2 detection concepts and methods that use polarization features are described. Secti

  17. Visible and infrared detectors at Rockwell Science Center

    Science.gov (United States)

    Kozlowski, Lester J.; Montroy, John T.; Cabelli, Craig A.; Cooper, Donald E.; Chen, Annie C.; Bostrup, Gary L.; Bai, Yibin; Vural, Kadri; Hodapp, Klaus-Werner; Hall, Donald N.

    2000-08-01

    Rockwell Space Center is developing low-noise visible and IR imaging sensors and systems for astronomy, high-end commercial, NASA, and advanced military applications. The first science grade 2048 by 2048 HAWAII-2 focal plane array (FPA) for astronomy was recently demonstrated for the SWIR waveband. Science-grade deliveries to the University of Hawaii's Institute for Astronomy, the European Southern Observatory and the Subaru Telescope, among others, will soon start. MWIR/visible 2048 by 2048 HAWAII-2 arrays are also being developed for the NGST program using our process for removing the CdZnTe substrate from the back-side illuminated HgCdTe FPAs to detect visible radiation in addition to IR. Previously, more than 25 science grade 2.5micrometers 1024 by 1024 HAWAII FPAs were delivered for use in many observatories; these typically exhibit 90 percent with near-100 percent fill factor, and the dark current is negligible with minimum cooling. Our near-term plan to develop 4096 by 4096 visible and IR FPAs will also be discussed.

  18. "So, Like, What Now?": Making Identity Visible for Preservice Teachers

    Science.gov (United States)

    Jiménez, Laura M.

    2014-01-01

    Drawing on Vygostky's zone of proximal development this study explores the ways preservice teachers engage with The Human Bean Activity that was designed to make visible the abstract idea of identity and community. This qualitative narrative analysis explores the talk produced by 47 predominantly White, straight, and female preservice…

  19. 40 CFR 52.26 - Visibility monitoring strategy.

    Science.gov (United States)

    2010-07-01

    ... in any State whose State implementation plan is subject to a disapproval for failure to satisfy 40... visibility within each such area: (i) photographic cameras, (ii) fine particulate matter samplers, (iii... independently. These data shall be available to any person, subject to reasonable charges for copying....

  20. On measuring the visibility with motor-car headlighting.

    NARCIS (Netherlands)

    Boer, J.B. & Vermeulen, D.

    1951-01-01

    There is a distinct deference between American and European opinions about the most suitable beam pattern of motor-car headlights. The American point of view has been published in the Annexe to the Report 23b of the I.C.I. 1939 by H.M. Magdsick entitled: Some factors governing visibility distances

  1. Skyglow effects in UV and visible spectra: Radiative fluxes

    Science.gov (United States)

    Kocifaj, Miroslav; Solano Lamphar, Hector Antonio

    2013-09-01

    Several studies have tried to understand the mechanisms and effects of radiative transfer under different night-sky conditions. However, most of these studies are limited to the various effects of visible spectra. Nevertheless, the invisible parts of the electromagnetic spectrum can pose a more profound threat to nature. One visible threat is from what is popularly termed skyglow. Such skyglow is caused by injudiciously situated or designed artificial night lighting systems which degrade desired sky viewing. Therefore, since lamp emissions are not limited to visible electromagnetic spectra, it is necessary to consider the complete spectrum of such lamps in order to understand the physical behaviour of diffuse radiation at terrain level. In this paper, the downward diffuse radiative flux is computed in a two-stream approximation and obtained ultraviolet spectral radiative fluxes are inter-related with luminous fluxes. Such a method then permits an estimate of ultraviolet radiation if the traditionally measured illuminance on a horizontal plane is available. The utility of such a comparison of two spectral bands is shown, using the different lamp types employed in street lighting. The data demonstrate that it is insufficient to specify lamp type and its visible flux production independently of each other. Also the UV emissions have to be treated by modellers and environmental scientists because some light sources can be fairly important pollutants in the near ultraviolet. Such light sources can affect both the living organisms and ambient environment.

  2. Visibility and anonymity effects on attraction and group cohesiveness

    NARCIS (Netherlands)

    Lea, Martin; Spears, Russell; Watt, Susan E.

    2007-01-01

    This study investigated attraction and group cohesiveness under different visibility and anonymity conditions for social categories that differed in their capacity to be visually cued. Using computer-mediated communication in 36 mixed gender (visually cued category) and nationality (non-visually cue

  3. Visible Spectrum Circular Dichroism in Extrinsic Chirality Metamaterials

    CERN Document Server

    Lee, Seoungjun; Feng, Cheng; Jiao, Jiao; Khan, Ashfaq; Li, Lin

    2012-01-01

    We present the new planar extrinsic chirality metamaterial (ECM) design that manifests giant circular dichroism (CD) in the visible spectrum range rather than usual near-infrared and terahertz range. Effects of incident beam angles and meta-molecules unit sizes on the CD spectrums were theoretically analyzed; Physical mechanism was illustrated in new figures of asymmetrical current excitation in neighboring unit cells.

  4. Mis asi on OÜ Visible Solutions? / Indrek Grigor

    Index Scriptorium Estoniae

    Grigor, Indrek

    2011-01-01

    Kunstiteos-ettevõtte OÜ Visible Solutions (juhatus: Sigrid Viir, Taaniel Raudsepp, Karel Koplimets) näitus "Adam Smithi Lemmik Nähtamatu Käsi Puuris" Tartu Kunstimajas 18. dets.-ni 2011. Kunstiprojekt firmast, mille tegevuse objekt on loomemajanduse kritiseerimine, mida tehakse viimase toimeloogika kunstiväljal eksponeerimise abil

  5. Making Practice Visible through Writing for Professional Publication

    Science.gov (United States)

    Roberts, Sherron Killingsworth

    2016-01-01

    Why should educators and service professionals bother writing for professional publication? Experienced editor, Sherron Roberts says writing for professional publication allows educators to share their work and make their practice visible. Any educator is quite capable of writing for a professional publication. This article is intended to show…

  6. Mis asi on OÜ Visible Solutions? / Indrek Grigor

    Index Scriptorium Estoniae

    Grigor, Indrek

    2011-01-01

    Kunstiteos-ettevõtte OÜ Visible Solutions (juhatus: Sigrid Viir, Taaniel Raudsepp, Karel Koplimets) näitus "Adam Smithi Lemmik Nähtamatu Käsi Puuris" Tartu Kunstimajas 18. dets.-ni 2011. Kunstiprojekt firmast, mille tegevuse objekt on loomemajanduse kritiseerimine, mida tehakse viimase toimeloogika kunstiväljal eksponeerimise abil

  7. Resonator design for a visible wavelength free-electron laser (*)

    Energy Technology Data Exchange (ETDEWEB)

    Bhowmik, A.; Lordi, N. (Rockwell International Corp., Canoga Park, CA (United States). Rocketdyne Div.); Ben-Zvi, I.; Gallardo, J. (Brookhaven National Lab., Upton, NY (United States))

    1990-01-01

    Design requirements for a visible wavelength free-electron laser being developed at the Accelerator Test Facility at Brookhaven National Laboratory are presented along with predictions of laser performance from 3-D numerical simulations. The design and construction of the optical resonator, its alignment and control systems are also described. 15 refs., 8 figs., 4 tabs.

  8. 40 CFR 798.5200 - Mouse visible specific locus test.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 31 2010-07-01 2010-07-01 true Mouse visible specific locus test. 798.5200 Section 798.5200 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC...)F1 or (101×C3H)F1 hybrids. Females shall be T stock virgins. (ii) Age. Healthy sexually...

  9. Seeing elements by visible-light digital camera.

    Science.gov (United States)

    Zhao, Wenyang; Sakurai, Kenji

    2017-03-31

    A visible-light digital camera is used for taking ordinary photos, but with new operational procedures it can measure the photon energy in the X-ray wavelength region and therefore see chemical elements. This report describes how one can observe X-rays by means of such an ordinary camera - The front cover of the camera is replaced by an opaque X-ray window to block visible light and to allow X-rays to pass; the camera takes many snap shots (called single-photon-counting mode) to record every photon event individually; an integrated-filtering method is newly proposed to correctly retrieve the energy of photons from raw camera images. Finally, the retrieved X-ray energy-dispersive spectra show fine energy resolution and great accuracy in energy calibration, and therefore the visible-light digital camera can be applied to routine X-ray fluorescence measurement to analyze the element composition in unknown samples. In addition, the visible-light digital camera is promising in that it could serve as a position sensitive X-ray energy detector. It may become able to measure the element map or chemical diffusion in a multi-element system if it is fabricated with external X-ray optic devices. Owing to the camera's low expense and fine pixel size, the present method will be widely applied to the analysis of chemical elements as well as imaging.

  10. Improved spring model-based collaborative indoor visible light positioning

    Science.gov (United States)

    Luo, Zhijie; Zhang, WeiNan; Zhou, GuoFu

    2016-06-01

    Gaining accuracy with indoor positioning of individuals is important as many location-based services rely on the user's current position to provide them with useful services. Many researchers have studied indoor positioning techniques based on WiFi and Bluetooth. However, they have disadvantages such as low accuracy or high cost. In this paper, we propose an indoor positioning system in which visible light radiated from light-emitting diodes is used to locate the position of receivers. Compared with existing methods using light-emitting diode light, we present a high-precision and simple implementation collaborative indoor visible light positioning system based on an improved spring model. We first estimate coordinate position information using the visible light positioning system, and then use the spring model to correct positioning errors. The system can be employed easily because it does not require additional sensors and the occlusion problem of visible light would be alleviated. We also describe simulation experiments, which confirm the feasibility of our proposed method.

  11. Rock fracture image acquisition with both visible and ultraviolet illuminations

    Science.gov (United States)

    Wang, Weixing; Hakami, Eva

    2006-02-01

    Swedish Nuclear Fuel and Waste Management Company (SKB) have identified the need for a better understanding of radionuclide transport and retention processes in fractured rock since 1994. In the study, the first hard problem is to obtain rock fracture images of a good quality, since rock surface is very rough, and composed of complicated and multiple fractures, as a result, image acquisition is the first important. As a cooperation project between Sweden and China, we sampled a number of rock specimens for analyzing rock fracture network by visible and ultraviolet image technique, in the field. The samples are resin injected, in which way; opened fractures can be seen clearly by means of UV light illumination, and the rock surface information can be obtained by using visible optical illumination. We used different digital cameras and microscope to take images by two illuminations. From the same samples; we found that UV illumination image gives the clear information of fracture opening or closing, and the visible optical illumination gives the information of the rock surface (e.g. filling materials inside of fractures). By applying this technique, the minimum width of rock fracture 0.01 mm can be analyzed. This paper presents: (1) Rock fracture image acquiring techniques; (2) Rock fracture image acquisition by using UV light illumination and visible optical illumination; and (3) Conclusions. The studied method can be used both in the field and a laboratory.

  12. Rainbow Visibility: How One Catholic University Responded to Intolerance.

    Science.gov (United States)

    Getz, Cheryl; Kirkley, Evelyn A.

    2002-01-01

    When intolerance of gays and lesbians at the University of San Diego became a problem, a group of students, staff, and faculty decided to do something about it. The result was a project called Rainbow Visibility that works on many forms to educate the campus community. (Author)

  13. Measurement of visibility from the pilot's cockpit on different airplane types

    Science.gov (United States)

    Kurz, Gerhard

    1931-01-01

    A process for the measurement of the visibility of airplanes from the pilot's cockpit is developed. The apparatus necessary for the measurements was suitably constructed and measurements of the fields of vision were made with it. The visibilities of six airplanes of different types of construction and use were measured, as well as the visibility of an automobile for comparison. An attempt was made to establish minimum visibility requirements and to express the excellence of visibility by means of a numerical coefficient.

  14. Robust pedestrian detection by combining visible and thermal infrared cameras.

    Science.gov (United States)

    Lee, Ji Hoon; Choi, Jong-Suk; Jeon, Eun Som; Kim, Yeong Gon; Le, Toan Thanh; Shin, Kwang Yong; Lee, Hyeon Chang; Park, Kang Ryoung

    2015-05-05

    With the development of intelligent surveillance systems, the need for accurate detection of pedestrians by cameras has increased. However, most of the previous studies use a single camera system, either a visible light or thermal camera, and their performances are affected by various factors such as shadow, illumination change, occlusion, and higher background temperatures. To overcome these problems, we propose a new method of detecting pedestrians using a dual camera system that combines visible light and thermal cameras, which are robust in various outdoor environments such as mornings, afternoons, night and rainy days. Our research is novel, compared to previous works, in the following four ways: First, we implement the dual camera system where the axes of visible light and thermal cameras are parallel in the horizontal direction. We obtain a geometric transform matrix that represents the relationship between these two camera axes. Second, two background images for visible light and thermal cameras are adaptively updated based on the pixel difference between an input thermal and pre-stored thermal background images. Third, by background subtraction of thermal image considering the temperature characteristics of background and size filtering with morphological operation, the candidates from whole image (CWI) in the thermal image is obtained. The positions of CWI (obtained by background subtraction and the procedures of shadow removal, morphological operation, size filtering, and filtering of the ratio of height to width) in the visible light image are projected on those in the thermal image by using the geometric transform matrix, and the searching regions for pedestrians are defined in the thermal image. Fourth, within these searching regions, the candidates from the searching image region (CSI) of pedestrians in the thermal image are detected. The final areas of pedestrians are located by combining the detected positions of the CWI and CSI of the thermal

  15. Doppler visibility of coherent random noise radar systems

    Science.gov (United States)

    Li, Zhixi; Narayanan, Ram M.

    2005-05-01

    Random noise radar has recently been used in a variety of imaging and surveillance applications. These systems can be made phase coherent using the technique of heterodyne correlation. Phase coherence has been exploited to measure Doppler and thereby the velocity of moving targets. The Doppler visibility, i.e., the ability to extract Doppler information over the inherent clutter spectra, is constrained by system parameters, especially the phase noise generated by microwave components. Our paper proposes a new phase noise model for the heterodyne mixer as applicable for ultrawideband (UWB) random noise radar and for the local oscillator in the time domain. The Doppler spectra are simulated by including phase noise contamination effects and compared to our previous experimental results. A Genetic Algorithm (GA) optimization routine is applied to synthesize the effects of a variety of parameter combinations to derive a suitable empirical formula for estimating the Doppler visibility in dB. According to the phase noise analysis and the simulation results, the Doppler visibility of UWB random noise radar depends primarily on the following parameters: (a) the local oscillator (LO) drive level of the receiver heterodyne mixer; (b) the saturation current in the receiver heterodyne mixer; (c) the bandwidth of the transmit noise source, and; (d) the target velocity. Other parameters such as the carrier frequency of the receiver LO and the loaded quality factor of the LO have a small effect over the range of applicability of the model and are therefore neglected in the model formulation. The Doppler visibility curves generated from this formula match the simulation results very well over the applicable parameter range within 1 dB. Our model may therefore be used to quickly estimate the Doppler visibility of random noise radars for trade-off analysis.

  16. Visible-near-infrared luminescent lanthanide ternary complexes based on beta-diketonate using visible-light excitation.

    Science.gov (United States)

    Sun, Lining; Qiu, Yannan; Liu, Tao; Feng, Jing; Deng, Wei; Shi, Liyi

    2015-11-01

    We used the synthesized dinaphthylmethane (Hdnm) ligand whose absorption extends to the visible-light wavelength, to prepare a family of ternary lanthanide complexes, named as [Ln(dnm)3 phen] (Ln = Sm, Nd, Yb, Er, Tm, Pr). The properties of these complexes were investigated by Fourier transform infrared (FT-IR) spectroscopy, diffuse reflectance (DR) spectroscopy, thermogravimetric analyses, and excitation and emission spectroscopy. Generally, excitation with visible light is much more advantageous than UV excitation. Importantly, upon excitation with visible light (401-460 nm), the complexes show characteristic visible (Sm(3+)) as well as near-infrared (Sm(3+), Nd(3+), Yb(3+), Er(3+), Tm(3+), Pr(3+)) luminescence of the corresponding lanthanide ions, attributed to the energy transfer from the ligands to the lanthanide ions, an antenna effect. Now, using these near-infrared luminescent lanthanide complexes, the luminescent spectral region from 800 to 1650 nm, can be covered completely, which is of particular interest for biomedical imaging applications, laser systems, and optical amplification applications.

  17. Simulating Visibility Under Reduced Acuity and Contrast Sensitivity

    Science.gov (United States)

    Thompson, William B.; Legge, Gordon E.; Kersten, Daniel J.; Shakespeare, Robert A.; Lei, Quan

    2017-01-01

    Architects and lighting designers have difficulty designing spaces that are accessible to those with low vision, since the complex nature of most architectural spaces requires a site-specific analysis of the visibility of mobility hazards and key landmarks needed for navigation. We describe a method that can be utilized in the architectural design process for simulating the effects of reduced acuity and contrast on visibility. The key contribution is the development of a way to parameterize the simulation using standard clinical measures of acuity and contrast sensitivity. While these measures are known to be imperfect predictors of visual function, they provide a way of characterizing general levels of visual performance that is familiar to both those working in low vision and our target end-users in the architectural and lighting design communities. We validate the simulation using a letter recognition task. PMID:28375328

  18. Multi-sensor person following in low-visibility scenarios.

    Science.gov (United States)

    Sales, Jorge; Marín, Raúl; Cervera, Enric; Rodríguez, Sergio; Pérez, Javier

    2010-01-01

    Person following with mobile robots has traditionally been an important research topic. It has been solved, in most cases, by the use of machine vision or laser rangefinders. In some special circumstances, such as a smoky environment, the use of optical sensors is not a good solution. This paper proposes and compares alternative sensors and methods to perform a person following in low visibility conditions, such as smoky environments in firefighting scenarios. The use of laser rangefinder and sonar sensors is proposed in combination with a vision system that can determine the amount of smoke in the environment. The smoke detection algorithm provides the robot with the ability to use a different combination of sensors to perform robot navigation and person following depending on the visibility in the environment.

  19. Multipath Reflections Analysis on Indoor Visible Light Positioning System

    CERN Document Server

    Gu, Wenjun; Kavehrad, Mohsen

    2015-01-01

    Visible light communication (VLC) has become a promising research topic in recent years, and finds its wide applications in indoor environments. Particularly, for location based services (LBS), visible light also provides a practical solution for indoor positioning. Multipath-induced dispersion is one of the major concerns for complex indoor environments. It affects not only the communication performance but also the positioning accuracy. In this paper, we investigate the impact of multipath reflections on the positioning accuracy of indoor VLC positioning systems. Combined Deterministic and Modified Monte Carlo (CDMMC) approach is applied to estimate the channel impulse response considering multipath reflections. Since the received signal strength (RSS) information is used for the positioning algorithm, the power distribution from one transmitter in a typical room configuration is first calculated. Then, the positioning accuracy in terms of root mean square error is obtained and analyzed.

  20. Rechargeable solid state neutron detector and visible radiation indicator

    Energy Technology Data Exchange (ETDEWEB)

    Stowe, Ashley C.; Wiggins, Brenden; Burger, Arnold

    2017-05-23

    A radiation detection device, including: a support structure; and a chalcopyrite crystal coupled to the support structure; wherein, when the chalcopyrite crystal is exposed to radiation, a visible spectrum of the chalcopyrite crystal changes from an initial color to a modified color. The visible spectrum of the chalcopyrite crystal is changed back from the modified color to the initial color by annealing the chalcopyrite crystal at an elevated temperature below a melting point of the chalcopyrite crystal over time. The chalcopyrite crystal is optionally a .sup.6LiInSe.sub.2 crystal. The radiation is comprised of neutrons that decrease the .sup.6Li concentration of the chalcopyrite crystal via a .sup.6Li(n,.alpha.) reaction. The initial color is yellow and the modified color is one of orange and red. The annealing temperature is between about 450 degrees C. and about 650 degrees C. and the annealing time is between about 12 hrs and about 36 hrs.

  1. Probing resonance decays to two visible and multiple invisible particles

    CERN Document Server

    Cho, Won Sang; Matchev, Konstantin T.; Park, Myeonghun

    2014-01-01

    We consider the decay of a generic resonance to two visible particles and any number of invisible particles. We show that the shape of the invariant mass distribution of the two visible particles is sensitive to both the mass spectrum of the new particles, as well as the decay topology. We provide the analytical formulas describing the invariant mass shapes for the nine simplest topologies (with up to two invisible particles in the final state). Any such distribution can be simply categorized by its endpoint, peak location and curvature, which are typically sufficient to discriminate among the competing topologies. In each case, we list the effective mass parameters which can be measured by experiment. In certain cases, the invariant mass shape is sufficient to completely determine the new particle mass spectrum, including the overall mass scale.

  2. A Visible Watermarking Scheme for Digital Images in Frequency Domain

    Directory of Open Access Journals (Sweden)

    D.R.Denslin Brabin

    2012-11-01

    Full Text Available A novel method is proposed for visible watermarking of digital image in frequency domain. The method is based on DCT modification of original image with respect to watermark image. The host image pixels are transformed into frequency coefficients as well as the watermark image pixels are also transformed into frequency coefficients using DCT. The compound mapping function is used to adjust the pixel values close to those of desired visible watermarks. Thus the watermarking is done in frequency domain using compound mapping function. One who has the watermark image and mapping function parameters only can remove the watermark. Thus it enhances the security. Experimental results demonstrate the effectiveness of the proposed approach.

  3. Beyond citations: Scholars' visibility on the social Web

    CERN Document Server

    Bar-Ilan, Judit; Peters, Isabella; Priem, Jason; Shema, Hadas; Terliesner, Jens

    2012-01-01

    Traditionally, scholarly impact and visibility have been measured by counting publications and citations in the scholarly literature. However, increasingly scholars are also visible on the Web, establishing presences in a growing variety of social ecosystems. But how wide and established is this presence, and how do measures of social Web impact relate to their more traditional counterparts? To answer this, we sampled 57 presenters from the 2010 Leiden STI Conference, gathering publication and citations counts as well as data from the presenters' Web "footprints." We found Web presence widespread and diverse: 84% of scholars had homepages, 70% were on LinkedIn, 23% had public Google Scholar profiles, and 16% were on Twitter. For sampled scholars' publications, social reference manager bookmarks were compared to Scopus and Web of Science citations; we found that Mendeley covers more than 80% of sampled articles, and that Mendeley bookmarks are significantly correlated (r=.45) to Scopus citation counts.

  4. Ⅱ-Ⅵ Visible-Blind UV Photodetectors

    Institute of Scientific and Technical Information of China (English)

    I.K. Sou

    2000-01-01

    This article gives a review on the physics and technical issues involved in the development of ZnS-based Ⅱ-Ⅵ visible-blind UV photodetectors. The results of photoresponse studies on ZnS, ZnSSe and ZnSTe diodes indicate that Te isoelectronic trapping effect is responsible for the gradual turn-on characteristic of low Te containing ZnSTe Schottky barrier photodiodes. The results also reveal that the ZnSSe diode, having the advantage of being free of isoelectronic centers, is a more suitable choice for applications requiring high visible rejection power. It is demonstrated that highly UV sensitive responsivity with an abrupt long wavelength cutoff tailored to lie between 340-400nm can be achieved in the ZnSSe diode system.

  5. Removal of Atmospheric Particles in Poor Visibility Outdoor Images

    Directory of Open Access Journals (Sweden)

    Yaseen Al-Zubaidy

    2013-08-01

    Full Text Available The visibility of a scene is degraded by weather phenomena such as rain drizzle, fog and haze. The degradation of image scene is due the substantial presence of particles in the atmosphere that scatter and absorb light. As the light spreads from object to the observer, the color and intensity is changed by the atmospheric particles. In this research, we suggest new methods to precisely detect airlight and correctly estimate the atmospheric veil from image that captured in bad weather. The result of suggested methods will be used in scattering atmospheric model to remove atmospheric particles namely, rain drizzle, fog and haze from a single image. Therefore a higher visibility image will be produced.

  6. Heterogeneous visible light photocatalysis for selective organic transformations.

    Science.gov (United States)

    Lang, Xianjun; Chen, Xiaodong; Zhao, Jincai

    2014-01-07

    The future development of chemistry entails environmentally friendly and energy sustainable alternatives for organic transformations. Visible light photocatalysis can address these challenges, as reflected by recent intensive scientific endeavours to this end. This review covers state-of-the-art accomplishments in visible-light-induced selective organic transformations by heterogeneous photocatalysis. The discussion comprises three sections based on the photocatalyst type: metal oxides such as TiO2, Nb2O5 and ZnO; plasmonic photocatalysts like nanostructured Au, Ag or Cu supported on metal oxides; and polymeric graphitic carbon nitride. Finally, recent strides in bridging the gap between photocatalysis and other areas of catalysis will be highlighted with the aim of overcoming the existing limitations of photocatalysis by developing more creative synthetic methodologies.

  7. Visible Light Photocatalysis: The Development of Photocatalytic Radical Ion Cycloadditions.

    Science.gov (United States)

    Yoon, Tehshik P

    2013-05-03

    Photochemistry has the potential to significantly impact multiple aspects of chemical synthesis, in part because photoinduced reactions can be used to construct molecular architectures that would otherwise be difficult to produce. Nevertheless, organic chemists have been slow to embrace photochemical synthesis because of technical complications associated with the use of ultraviolet light. Our laboratory has been part of an effort to design synthetically useful reactions that utilize visible light. This strategy enables the synthesis of a diverse range of organic structures by generation of a variety of reactive intermediates under exceptionally mild conditions. This Perspective article describes the reasoning that led to the conception of our first experiments in this area, the features of our reaction design that have been most powerful in the discovery of new processes, and a few of the possible future areas in which visible light photocatalysis might have a large impact.

  8. A Fourier transform Raman spectrometer with visible laser excitation

    CERN Document Server

    Dzsaber, S; Bernáth, B; Gyüre, B; Fehér, T; Kramberger, C; Pichler, T; Simon, F

    2014-01-01

    We present the development and performance of a Fourier transformation (FT) based Raman spectrometer working with visible laser (532 nm) excitation. It is generally thought that FT-Raman spectrometers are not viable in the visible range where shot-noise limits the detector performance and therein they are outperformed by grating based, dispersive ones. We show that contrary to this common belief, the recent advances of high-performance interference filters makes the FT-Raman design a valid alternative to dispersive Raman spectrometers for samples which do not luminesce. We critically compare the performance of our spectrometer to two dispersive ones: a home-built single channel and a state-of-the-art CCD based instruments. We demonstrate a similar or even better sensitivity than the CCD based dispersive spectrometer particularly when the laser power density is considered. The instrument possesses all the known advantages of the FT principle of spectral accuracy, high throughput, and economic design. We also d...

  9. A review of astronomical science with visible light adaptive optics

    Science.gov (United States)

    Close, Laird M.

    2016-07-01

    We review astronomical results in the visible (λRobo-AO system (Baranec, et al. 2016) on the robotic Palomar D=1.5 m telescope (currently relocated to the Kitt Peak 1.8m; Salama et al. 2016). Robo-AO uniquely offers the ability to target >15 objects/hr, which has enabled large (>3000 discrete targets) companion star surveys and has resulted in 23 refereed science publications. The most productive large telescope visible AO system is the D=6.5m Magellan telescope AO system (MagAO). MagAO is an advanced Adaptive Secondary Mirror (ASM) AO system at the Magellan 6.5m in Chile (Morzinski et al. 2016). This ASM secondary has 585 actuators with 10m) diameter telescopes in the infrared.

  10. Visibility and findability of the nursing home compare website.

    Science.gov (United States)

    Liu, Darren; Lu, Chi-Jung

    2015-01-01

    Nursing Home Compare (NHC) is a federal government website providing information for selecting a nursing home. However, not many consumers were aware of or can locate the site. This study analyzed 50 official state and District of Columbia websites from September through December 2013. Using Google "inlink:" operator, this study evaluated the visibility and findability of NHC links in each state-level website. The results show that a link to NHC is available in all states except for Connecticut, Florida, and Michigan. Although it took only 4.7 clicks on average to the page with a NHC link, consumers may still have difficulty to find NHC from a state website. This article provides a snapshot of the visibility and findability of NHC and indicates a need for further investigation of promising website dissemination strategies not yet adequately evaluated.

  11. Visible light laser voltage probing on thinned substrates

    Energy Technology Data Exchange (ETDEWEB)

    Beutler, Joshua; Clement, John Joseph; Miller, Mary A.; Stevens, Jeffrey; Cole, Jr., Edward I.

    2017-03-21

    The various technologies presented herein relate to utilizing visible light in conjunction with a thinned structure to enable characterization of operation of one or more features included in an integrated circuit (IC). Short wavelength illumination (e.g., visible light) is applied to thinned samples (e.g., ultra-thinned samples) to achieve a spatial resolution for laser voltage probing (LVP) analysis to be performed on smaller technology node silicon-on-insulator (SOI) and bulk devices. Thinning of a semiconductor material included in the IC (e.g., backside material) can be controlled such that the thinned semiconductor material has sufficient thickness to enable operation of one or more features comprising the IC during LVP investigation.

  12. Visible and VUV images of dielectric barrier discharges in Xe

    Energy Technology Data Exchange (ETDEWEB)

    Mildren, R.P. [Centre for Lasers and Applications, Macquarie University, Sydney, NSW (Australia); Carman, R.J. [Department of Physics, Macquarie University, Sydney, NSW (Australia); Falconer, I.S. [School of Physics A28, University of Sydney, Sydney, NSW (Australia)

    2001-12-07

    We have recorded short exposure images of visible and vacuum ultraviolet (VUV) emission from a Xe dielectric barrier discharge lamp, and investigated the effects of excitation by fast rising pulse and sinusoidal voltage waveforms on the discharge structure. The images from the pulsed discharge are essentially uniform over the active electrode area unlike the sinusoidal discharge which is filamentary. By investigating a single filament discharge, it is also found that a large fraction ((>)90%) of the total visible and VUV emission for sinusoidal excitation is generated from regions outside the filament. The images suggest that the VUV is generated from surface discharges, or 'feelers', which branch out laterally from the filaments. Model calculations suggest that surface or volume discharges, in which the current density is much lower than for filamentary discharges, generate VUV emission more efficiently due to the reduced rate for multi-step electron excitation of Xe* species. (author)

  13. Time series characterization via horizontal visibility graph and Information Theory

    Science.gov (United States)

    Gonçalves, Bruna Amin; Carpi, Laura; Rosso, Osvaldo A.; Ravetti, Martín G.

    2016-12-01

    Complex networks theory have gained wider applicability since methods for transformation of time series to networks were proposed and successfully tested. In the last few years, horizontal visibility graph has become a popular method due to its simplicity and good results when applied to natural and artificially generated data. In this work, we explore different ways of extracting information from the network constructed from the horizontal visibility graph and evaluated by Information Theory quantifiers. Most works use the degree distribution of the network, however, we found alternative probability distributions, more efficient than the degree distribution in characterizing dynamical systems. In particular, we find that, when using distributions based on distances and amplitude values, significant shorter time series are required. We analyze fractional Brownian motion time series, and a paleoclimatic proxy record of ENSO from the Pallcacocha Lake to study dynamical changes during the Holocene.

  14. Colored visible light metamaterials based on random dendritic cells

    CERN Document Server

    Song, K; Liu, B Q; Zhao, X P

    2011-01-01

    Optical metamaterials(OMs) at visible wavelengths have been extensively developed. OMs reported presently are all composed of periodic structure, and fabricated by top-down approaches. Here, the colored visible light frequencies metamaterials composed of double layer array disordered and geometrical variational dendritic cells are demonstrated, fabricating by a novel bottom-up approach. The experiment demonstrated that the OMs composed of random silver dendritic cells caused the appearance of multiple transmission passbands at red and yellow light frequencies. The slab focusing experiment reveals a clear point image in the range of half-wavelength with an intensity of 5% higher than that of the light source. Proposed colored OMs will open a new way to prepare the cloak and the perfect lens suitable for optical frequency.

  15. Domesticating Visibility. The Chinese Internet between Labor and Praxis

    Directory of Open Access Journals (Sweden)

    Allan BAHROUN

    2016-12-01

    Full Text Available The less we question the technical and semiotic properties of the so-called social media, the more oblivious we remain to their political agency. The media transformations, which occurred in China at incredible speed and depth, must lead us to question the ways in which ‘new media’ affect the sites and forms of power. This article offers a reading into the economic and theoretical dynamics of what is commonly referred to as the ‘Chinese Internet’. Its history is marked by strategic attempts to shape, constrain and leverage social visibility. Thus, the author uses the notion of computerized media and invokes Hannah Arendt’s conception of visibility to describe what appears in China to be a new form of globalized media capitalism.

  16. Raman crystal lasers in the visible and near-infrared

    Institute of Scientific and Technical Information of China (English)

    EICHLERH.J.; GADG.M.A.; KAMINSKIIA.A.; RHEEH.

    2003-01-01

    Raman lasers based on potassium gadolinium tungstate and lead tungstate crystals pumped by a≈120 ps Nd: YAG laser at 1.064/μm were developed. High reflection mirrors for the Stokes wavelength have been used to generate near-infrared and eye safe spectral region of 1.15 - 1.32/μm. Second harmonic generation of the generated Raman lasers was observed. Eifficient multiple Stokes and anti-Stokes picosecond generation in 64 crystals have been shown to exhibit stimulated Raman scattering on about 700 lines covering the whole visible and near-infrared spectrum. All stimulated Raman scattering (SRS) wavelengths in the visible and near-infrared spectrum are identified and attributed to the SRS-active vibration modes of these crystals.

  17. Raman crystal lasers in the visible and near-infrared

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    Raman lasers based on potassium gadolinium tungstate and lead tungstate crystals pumped by a≈120 ps Nd: YAG laser at 1.064 μm were developed. High reflection mirrors for the Stokes wavelength have been used to generate near-infrared and eye safe spectral region of 1.15-1.32 μm. Second harmonic generation of the generated Raman lasers was observed. Eifficient multiple Stokes and anti-Stokes picosecond generation in 64 crystals have been shown to exhibit stimulated Raman scattering on about 700 lines covering the whole visible and near-infrared spectrum. All stimulated Raman scattering (SRS) wavelengths in the visible and near-infrared spectrum are identified and attributed to the SRS-active vibration modes of these crystals.

  18. Does a Graphical Abstract Bring More Visibility to Your Paper?

    Directory of Open Access Journals (Sweden)

    Eva-Maria Pferschy-Wenzig

    2016-09-01

    Full Text Available A graphical abstract (GA represents a piece of artwork that is intended to summarize the main findings of an article for readers at a single glance. Many publishers currently encourage authors to supplement their articles with GAs, in the hope that such a convenient visual summary will facilitate readers with a clearer outline of papers that are of interest and will result in improved overall visibility of the respective publication. To test this assumption, we statistically compared publications with or without GA published in Molecules between March 2014 and March 2015 with regard to several output parameters reflecting visibility. Contrary to our expectations, manuscripts published without GA performed significantly better in terms of PDF downloads, abstract views, and total citations than manuscripts with GA. To the best of our knowledge, this is the first empirical study on the effectiveness of GA for attracting attention to scientific publications.

  19. El desarrollo de las emociones haciendo el pensamiento visible

    OpenAIRE

    Cascales Ribera, María del Carmen

    2016-01-01

    El presente Trabajo Final de Grado (TFG) permite desarrollar la competencia emocional del alumnado de Educación Primaria haciendo el pensamiento visible a través de rutinas de pensamiento. El presente TFG presenta un programa de actividades educativas relativas al área de educación emocional, que permite manejar las propias emociones, reconocer las emociones en los demás y establecer relaciones. Educación Psicología

  20. Uranium plasma emission coefficient in the visible and near UV.

    Science.gov (United States)

    Mack, J. M., Jr.; Usher, J. L.; Schneider, R. T.; Campbell, H. D.

    1971-01-01

    Measurements of the specific emission coefficient in the near ultra-violet and visible region of a uranium arc plasma are reported. Spatial unfolding of the intensity profile is used to determine the emission coefficient in the spectral range of 2000 A to 6000 A. The uranium partial pressure is estimated to range between .001 and .01 atmosphere, and the corresponding temperature range is 5000 - 10,000 K.

  1. Uranium plasma emission coefficient in the visible and near UV.

    Science.gov (United States)

    Mack, J. M., Jr.; Usher, J. L.; Schneider, R. T.; Campbell, H. D.

    1971-01-01

    Measurements of the specific emission coefficient in the near ultra-violet and visible region of a uranium arc plasma are reported. Spatial unfolding of the intensity profile is used to determine the emission coefficient in the spectral range of 2000 A to 6000 A. The uranium partial pressure is estimated to range between .001 and .01 atmosphere, and the corresponding temperature range is 5000 - 10,000 K.

  2. DESIGN OF VISIBLE DIAGNOSTIC BEAMLINE FOR NSLS2 STORAGE RING

    Energy Technology Data Exchange (ETDEWEB)

    Cheng, W.; Fernandes, H.; Hseuh, H.; Kosciuk, B.; Krinsky, S.; Singh, O.

    2011-03-28

    A visible synchrotron light monitor (SLM) beam line has been designed at the NSLS2 storage ring, using the bending magnet radiation. A retractable thin absorber will be placed in front of the first mirror to block the central x-rays. The first mirror will reflect the visible light through a vacuum window. The light is guided by three 6-inch diameter mirrors into the experiment hutch. In this paper, we will describe design work on various optical components in the beamline. The ultra high brightness NSLS-II storage ring is under construction at Brookhaven National Laboratory. It will have 3GeV, 500mA electron beam circulating in the 792m ring, with very low emittance (0.9nm.rad horizontal and 8pm.rad vertical). The ring is composed of 30 DBA cells with 15 fold symmetry. Three damping wigglers will be installed in long straight sections 8, 18 and 28 to lower the emittance. While electrons pass through the bending magnet, synchrotron radiation will be generated covering a wide spectrum. There are other insertion devices in the storage ring which will generate shorter wavelength radiation as well. Synchrotron radiation has been widely used as diagnostic tool to measure the transverse and longitudinal profile. Three synchrotron light beam lines dedicated for diagnostics are under design and construction for the NSLS-II storage ring: two x-ray beam lines (pinhole and CRL) with the source points from Cell 22 BM{_}A (first bending in the DBA cell) and Cell22 three-pole wiggler; the third beam line is using visible part of radiation from Cell 30 BM{_}B (second bending magnet from the cell). Our paper focuses on the design of the visible beam line - SLM.

  3. Visible light scatter as quantitative information source on milk constituents

    DEFF Research Database (Denmark)

    Melentieva, Anastasiya; Kucheryavskiy, Sergey; Bogomolov, Andrey

    2012-01-01

    VISIBLE LIGHT SCATTER AS A QUANTITATIVE INFORMATION SOURCE ON MILK CONSTITUENTS A. Melenteva 1, S. Kucheryavski 2, A. Bogomolov 1,31Samara State Technical University, Molodogvardeyskaya Street 244, 443100 Samara, Russia. 2Aalborg University, campus Esbjerg, Niels Bohrs vej 8, 6700 Esbjerg, Denmar...... research area are presented and discussed. References: [1] A. Bogomolov, S. Dietrich, B. Boldrini, R.W. Kessler, Food Chemistry (2012), doi:10.1016/j.foodchem.2012.02.077....

  4. Assessment of Refueling Hose Visibility: Post-Cleaning Evaluation

    Science.gov (United States)

    2013-10-01

    visibility, contrast, illumination, viewing geometries, spectral band, NVG , SWIR, LWIR, standards 16. SECURITY CLASSIFICATION OF: 17. LIMITATION OF...drogue which incorporates a white canopy over 52” in diameter with a 1 foot wide white cloth used for rotary wing helicopters aerial refueling. Night...Light-Emitting Diode LWIR – Long-Wave Infra-Red Navair – U.S. Navy Naval Air Systems Command NVG – Night Vision Goggles SWIR – Short-Wave Infra-Red

  5. Impact of Reduced Visibility from Fog on Traffic Sign Detection

    OpenAIRE

    Belaroussi, Rachid; Gruyer, Dominique

    2014-01-01

    In camera-based Advance Driver Assistance System (ADAS) such as traffic sign recognition, some failure may be inferred by adverse meteorological conditions, in particular under foggy weather. This paper investigates the effects of reduced visibility from fog in an ADAS operating range, more specifically a traffic sign detection algorithm. For this purpose, we produced a database of synthetic images containing road signs with and without fog, that is intended to be shared with the scientific c...

  6. Improving Visibility of Diffraction Pattern with Pseudo-Thermal Light

    Institute of Scientific and Technical Information of China (English)

    GAO Lu; XIONG Jun; ZHANG Shu-Heng; WANG Wei; WANG Kai-Ge

    2008-01-01

    @@ We report an experimental observation of Poisson's spot with pseudo-thermal light. The experimental results show that the diffraction pattern disappears in the intensity distribution behind the opaque disc but emerges through both auto-correlation and cross-correlation intensity measurements. The auto-correlation scheme can take care of both better visibility and higher resolution of the diffraction pattern under the condition that the thermal light source has a larger spectral bandwidth.

  7. Making design pedagogical content knowledge visible within design reviews

    OpenAIRE

    Adams, Robin; Radcliffe, David; Forin, Tiago; Chua, Mel

    2014-01-01

    Design pedagogical content knowledge (PCK) is the content-specific specialized teacher knowledge that connects the how (pedagogical knowledge) and what (content knowledge) of teaching design. In this study, we make visible the design PCK in three student design reviews: choreography, undergraduate industrial design, and mechanical engineering. We use cognitive apprenticeship and teaching-as-improvisation frameworks to characterize PK, and design judgment, design task strategies, and process m...

  8. Fourier transform spectroscopy in the visible and ultraviolet range.

    Science.gov (United States)

    Luc, P; Gerstenkorn, S

    1978-05-01

    In cases where the photon noise is the limiting factor, the multiplex gain is not always conserved; however the throughput (Jacquinot's advantage) is not affected. Therefore extension of Fourier transform spectroscopy to higher frequencies has great possibilities. Studies at high resolution, both in emission and in absorption, show that the performance achieved by Fourier transform spectroscopy in the visible and uv range is comparable with that reached in the ir.

  9. Researching in education findings visibility: How Cubans are doing?

    Directory of Open Access Journals (Sweden)

    Torres, Paúl A.

    2012-07-01

    Full Text Available The paper presents an analysis of Cuban educational research visibility by considering international ranking positioning of intellectual production in the field of education. A case study is conducted with outstanding Cuban educational researchers comparing their results with other prestigious professionals in the continent. Finally, new basic resources are proposed and explained for improving Bibliometric indicators by taking advantage of Google Scholar potentials in favoring international ranking positioning.

  10. EXHIBITION VISIBILITY; case Moventas Gears Ltd Service WG division

    OpenAIRE

    Elijärvi, Maaret

    2014-01-01

    Wind power business has been developing rapidly during last 10 years and turbines are sprouting up around the globe in record numbers. Moventas Gears Oy is one of the suppliers to the global wind turbine industry. Moventas Gears Oy has two different divisions on wind gear business, new manufacturing (CAP) and service (SER) divisions. The purpose of this work is to improve Moventas Gears Wind Service (SER) marketing visibility and as a target was taken exhibitions. In this work, will be co...

  11. An Improved Infrared/Visible Fusion for Astronomical Images

    Directory of Open Access Journals (Sweden)

    Attiq Ahmad

    2015-01-01

    Full Text Available An undecimated dual tree complex wavelet transform (UDTCWT based fusion scheme for astronomical visible/IR images is developed. The UDTCWT reduces noise effects and improves object classification due to its inherited shift invariance property. Local standard deviation and distance transforms are used to extract useful information (especially small objects. Simulation results compared with the state-of-the-art fusion techniques illustrate the superiority of proposed scheme in terms of accuracy for most of the cases.

  12. Emission of Visible Light by Hot Dense Metals

    Energy Technology Data Exchange (ETDEWEB)

    More, R.M.; Goto, M.; Graziani, F.; Ni, P.A.; Yoneda, H.

    2009-12-01

    We consider the emission of visible light by hot metal surfaces having uniform and non-uniform temperature distributions and by small droplets of liquid metal. The calculations employ a nonlocal transport theory for light emission, using the Kubo formula to relate microscopic current fluctuations to the dielectric function of the material. We describe a related algorithm for calculating radiation emission in particle simulation of hot fusion plasmas.

  13. Performance evaluation of transformer oil using uv-visible spectrophotometer

    OpenAIRE

    Karthik, Radha; National Engineering College; Raja, Thangaswamy Sree Renga; Anna University; Shunmugam, Sundaram Sudalai; National Engineering College

    2014-01-01

    To ensure reliable operation of Power transformer, condition monitoring of transformer becomes obligatory. In this paper, condition assessment of transformer oil under various working conditions is performed using UV-visible spectrophotometer. Test samples include both laboratorial prepared ones and those obtained from in service transformers.  An index table of spectral responses for various faults which predominantly occur in the transformer is developed. The index table will acts as a refe...

  14. A possible mechanism for visible-light-induced skin rejuvenation

    Science.gov (United States)

    Longo, Leonardo; Lubart, Rachel; Friedman, Harry; Lavie, R.

    2004-09-01

    In recent years there has been intensive research in the field of non-ablative skin rejuvenation. This comes as a response to the desire for a simple method of treating rhytids caused by aging, UV exposure and acne scars. In numerous studies intense visible light pulsed systems (20-30J/cm2) are used. The mechanism of action was supposed to be a selective heat induced denaturalization of dermal collagen that leads to subsequent reactive synthesis. In this study we suggest a different mechanism for photorejuvenation based on light induced Reactive Oxygen Species (ROS) formation. We irradiated collagen in-vitro with a broad band of visible light, 400-800 nm, 12-22J/cm2, and used the spin trapping coupled with electron paramagnetic resonance (EPR) spectroscopy to detect ROS. In vivo, we used dose 30 J in average (35 for acnis scars, 25 for wrinkles and redness). Irradiated collagen results in hydroxyl and methyl radicals formation. We propose, as a new concept, that visible light at the intensity used for skin rejuvenation, 20-30J/cm2, produces high amounts of ROS which destroy old collagen fibers encouraging the formation of new ones. On the other hand at inner depths of the skin, where the light intensity is much weaker, low amounts of ROS are formed which are well known to stimulate fibroblast proliferation.

  15. HI Fluctuations at Large Redshifts: I–Visibility correlation

    Indian Academy of Sciences (India)

    Somnath Bharadwaj; Shiv K. Sethi

    2001-12-01

    We investigate the possibility of probing the large scale structure in the universe at large redshifts by studying fluctuations in the redshifted 1420 MHz emission from the neutral hydrogen (HI) at early epochs. The neutral hydrogen content of the universe is knownfrom absorption studies for ≲ 4.5. The HI distribution is expected to be inhomogeneous in the gravitational instability picture and this inhomogeneity leads to anisotropy in the redshifted HI emission. The best hope of detecting this anisotropy is by using a large low-frequency interferometric instrument like the Giant Meter-Wave Radio Telescope (GMRT). We calculate the visibility correlation function $\\langle V_{v}(\\mathbf{U})V_{v'}(\\mathbf{U})\\rangle$ at two frequencies and ' of the redshifted HI emission for an interferometric observation. In particular we give numerical results for the two GMRT channels centered around =325 MHz and =610 MHz from density inhomogeneity and peculiar velocity of the HI distribution. The visibility correlation is ≃ 10-10-10-9 Jy2. We calculate the signal-to-noise for detecting the correlation signal in the presence of system noise and show that the GMRT might detect the signal for integration times ≃ 100 hrs. We argue that the measurement of visibility correlation allows optimal use of the uncorrelated nature of the system noise across baselines and frequency channels.

  16. Visible Nulling Coronagraphy Testbed Development for Exoplanet Detection

    Science.gov (United States)

    Lyon, Richard G.; Clampin, Mark; Woodruff, Robert A.; Vasudevan, Gopal; Thompson, Patrick; Chen, Andrew; Petrone, Peter; Booth, Andrew; Madison, Timothy; Bolcar, Matthew; Noecker, M. Charley; Kendrick, Stephen; Melnick, Gary; Tolls, Volker

    2010-01-01

    Three of the recently completed NASA Astrophysics Strategic Mission Concept (ASMC) studies addressed the feasibility of using a Visible Nulling Coronagraph (VNC) as the prime instrument for exoplanet science. The VNC approach is one of the few approaches that works with filled, segmented and sparse or diluted aperture telescope systems and thus spans the space of potential ASMC exoplanet missions. NASA/Goddard Space Flight Center (GSFC) has a well-established effort to develop VNC technologies and has developed an incremental sequence of VNC testbeds to advance the this approach and the technologies associated with it. Herein we report on the continued development of the vacuum Visible Nulling Coronagraph testbed (VNT). The VNT is an ultra-stable vibration isolated testbed that operates under high bandwidth closed-loop control within a vacuum chamber. It will be used to achieve an incremental sequence of three visible light nulling milestones of sequentially higher contrasts of 10(exp 8) , 10(exp 9) and 10(exp 10) at an inner working angle of 2*lambda/D and ultimately culminate in spectrally broadband (>20%) high contrast imaging. Each of the milestones, one per year, is traceable to one or more of the ASMC studies. The VNT uses a modified Mach-Zehnder nulling interferometer, modified with a modified "W" configuration to accommodate a hex-packed MEMS based deformable mirror, a coherent fiber bundle and achromatic phase shifters. Discussed will be the optical configuration laboratory results, critical technologies and the null sensing and control approach.

  17. The Swift-UVOT ultraviolet and visible grism calibration

    CERN Document Server

    Kuin, N P M; Breeveld, A A; Page, M J; James, C; Lamoureux, H; Mehdipour, M; Still, M; Yershov, V; Brown, P J; Carter, M; Mason, K O; Kennedy, T; Marshall, F; Roming, P W A; Siegel, M; Oates, S; Smith, P J; De Pasquale, M

    2015-01-01

    We present the calibration of the Swift UVOT grisms, of which there are two, providing low-resolution field spectroscopy in the ultraviolet and optical bands respectively. The UV grism covers the range 1700-5000 Angstrom with a spectral resolution of 75 at 2600 Angstrom for source magnitudes of u=10-16 mag, while the visible grism covers the range 2850-6600 Angstrom with a spectral resolution of 100 at 4000 Angstrom for source magnitudes of b=12-17 mag. This calibration extends over all detector positions, for all modes used during operations. The wavelength accuracy (1-sigma) is 9 Angstrom in the UV grism clocked mode, 17 Angstrom in the UV grism nominal mode and 22 Angstrom in the visible grism. The range below 2740 Angstrom in the UV grism and 5200 Angstrom in the visible grism never suffers from overlapping by higher spectral orders. The flux calibration of the grisms includes a correction we developed for coincidence loss in the detector. The error in the coincidence loss correction is less than 20%. The...

  18. Joint inpainting of depth and reflectance with visibility estimation

    Science.gov (United States)

    Bevilacqua, Marco; Aujol, Jean-François; Biasutti, Pierre; Brédif, Mathieu; Bugeau, Aurélie

    2017-03-01

    This paper presents a novel strategy to generate, from 3-D lidar measures, dense depth and reflectance images coherent with given color images. It also estimates for each pixel of the input images a visibility attribute. 3-D lidar measures carry multiple information, e.g. relative distances to the sensor (from which we can compute depths) and reflectances. When projecting a lidar point cloud onto a reference image plane, we generally obtain sparse images, due to undersampling. Moreover, lidar and image sensor positions typically differ during acquisition; therefore points belonging to objects that are hidden from the image view point might appear in the lidar images. The proposed algorithm estimates the complete depth and reflectance images, while concurrently excluding those hidden points. It consists in solving a joint (depth and reflectance) variational image inpainting problem, with an extra variable to concurrently estimate handling the selection of visible points. As regularizers, two coupled total variation terms are included to match, two by two, the depth, reflectance, and color image gradients. We compare our algorithm with other image-guided depth upsampling methods, and show that, when dealing with real data, it produces better inpainted images, by solving the visibility issue.

  19. An Adaptive and Hybrid Approach for Revisiting the Visibility Pipeline

    Directory of Open Access Journals (Sweden)

    Ícaro Lins Leitão da Cunha

    2016-04-01

    Full Text Available We revisit the visibility problem, which is traditionally known in Computer Graphics and Vision fields as the process of computing a (potentially visible set of primitives in the computational model of a scene. We propose a hybrid solution that uses a dry structure (in the sense of data reduction, a triangulation of the type J1a, to accelerate the task of searching for visible primitives. We came up with a solution that is useful for real-time, on-line, interactive applications as 3D visualization. In such applications the main goal is to load the minimum amount of primitives from the scene during the rendering stage, as possible. For this purpose, our algorithm executes the culling by using a hybrid paradigm based on viewing-frustum, back-face culling and occlusion models. Results have shown substantial improvement over these traditional approaches if applied separately. This novel approach can be used in devices with no dedicated processors or with low processing power, as cell phones or embedded displays, or to visualize data through the Internet, as in virtual museums applications.

  20. Comparison of visibility measurement techniques for forklift truck design factors.

    Science.gov (United States)

    Choi, Chin-Bong; Park, Peom; Kim, Young-Ho; Susan Hallbeck, M; Jung, Myung-Chul

    2009-03-01

    This study applied the light bulb shadow test, a manikin vision assessment test, and an individual test to a forklift truck to identify forklift truck design factors influencing visibility. The light bulb shadow test followed the standard of ISO/DIS 13564-1 for traveling and maneuvering tests with four test paths (Test Nos. 1, 3, 4, and 6). Digital human and forklift truck models were developed for the manikin vision assessment test with CATIA V5R13 human modeling solutions. Six participants performed the individual tests. Both employed similar parameters to the light bulb shadow test. The individual test had better visibility with fewer numbers and a greater distribution of the shadowed grids than the other two tests due to eye movement and anthropometric differences. The design factors of load backrest extension, lift chain, hose, dashboard, and steering wheel should be the first factors considered to improve visibility, especially when a forklift truck mainly performs a forward traveling task in an open area.

  1. [Visibility and productivity of the biomedical Peruvian journals].

    Science.gov (United States)

    Huamaní, Charles; Pacheco-Romero, José

    2009-01-01

    Biomedical journals have suffered world wide revolutions due to globalization of information, evolving from the printed version to the electronic one. The status of Peruvian medical journals is not currently known. To determine indexing, production for 2005 to 2007; and visibility of Peruvian biomedical journals for 2008. We identified indexed journals in Medline, SciELO-Peru, Redalyc, LILACS, and others, through informatic search and described the journals production with more indizations, estimating the original research production index. An analysis of electronic visibility of the journals most indexed in SciELO-Peru, Redalyc and SISBIB data bases is done. We identified 29 current journals by 2007. Only Revista de Gastroenterologia del Peru was indexed to Medline. Revista Peruana de Medicina Experimental y Salud Publica was the journal with more production, with 176 publications between 2005 and 2007.Anales de la Facultad de Medicina was the journal with the higher original investigation index, with 0,61. Anales de la Facultad de Medicina had the higher number of electronic visits with 963 965 visits in 2008. There is a great diversity of biomedical journals in Peru but few are indexed and only one is seen in Medline. Original research production is not high but journals electronic visibility is above 600 thousand visitors.

  2. Tracing You: How transparent surveillance reveals a desire for visibility

    Directory of Open Access Journals (Sweden)

    Benjamin Grosser

    2017-02-01

    Full Text Available Tracing You is an artwork that presents a website's best attempt to see the world from its visitors’ viewpoints. By cross referencing visitor IP addresses with available online data sources, the work traces each visitor back through the network to its possible origin. The end of that trace is the closest available image that potentially shows the visitor’s physical environment. Sometimes what this image shows is eerily accurate; other times it is wildly dislocated. This computational surveillance system thus makes transparent the potential visibility of one’s present location on the Earth, while also giving each site visitor the ability to watch other visitor “traces” in real time. By making its surveillance capacity and intention overt, Tracing You provokes questions about the architecture of networks and how that architecture affects our own visibility both within and outside of the network. Further, reactions to the work reveal attitudes towards surveillance post-Snowden, including, in some cases, an angry desire for more visibility than Tracing You currently provides. This commentary describes how the artwork functions, presents and discusses visitor reactions, and briefly theorizes origins for these reactions within the contexts of surveillance, sousveillance, and transparency in the age of ubiquitous online social networks.

  3. Visible and Infrared Optical Design for the ITER Upper Ports

    Energy Technology Data Exchange (ETDEWEB)

    Lasnier, C; Seppala, L; Morris, K; Groth, M; Fenstermacher, M; Allen, S; Synakowski, E; Ortiz, J

    2007-03-01

    This document contains the results of an optical design scoping study of visible-light and infrared optics for the ITER upper ports, performed by LLNL under contract for the US ITER Project Office. ITER is an international collaboration to build a large fusion energy tokamak with a goal of demonstrating net fusion power for pulses much longer than the energy confinement time. At the time of this report, six of the ITER upper ports are planned to each to contain a camera system for recording visible and infrared light, as well as other diagnostics. the performance specifications for the temporal and spatial resolution of this system are shown in the Section II, Functional Specifications. They acknowledge a debt to Y. Corre and co-authors of the CEA Cadarache report ''ITER wide-angle viewing and thermographic and visible system''. Several of the concepts used in this design are derived from that CEA report. The infrared spatial resolution for optics of this design is diffraction-limited by the size of the entrance aperture, at lower resolution than listed in the ITER diagnostic specifications. The size of the entrance aperture is a trade-off between spatial resolution, optics size in the port, and the location of relay optics. The signal-to-noise ratio allows operation at the specified time resolutions.

  4. Yttrium oxide based three dimensional metamaterials for visible light cloaking

    Science.gov (United States)

    Rai, Pratyush; Kumar, Prashanth S.; Varadan, Vijay K.; Ruffin, Paul; Brantley, Christina; Edwards, Eugene

    2014-04-01

    Metamaterial with negative refractive index is the key phenomenon behind the concept of a cloaking device to hide an object from light in visible spectrum. Metamaterials made of two and three dimensional lattices of periodically placed electromagnetic resonant cells can achieve absorption and propagation of incident electromagnetic radiation as confined electromagnetic fields confined to a waveguide as surface plasmon polaritons, which can be used for shielding an object from in-tune electromagnetic radiation. The periodicity and dimensions of resonant cavity determine the frequency, which are very small as compared to the wavelength of incident light. Till now the phenomena have been demonstrated only for lights in near infrared spectrum. Recent advancements in fabrication techniques have made it possible to fabricate array of three dimensional nanostructures with cross-sections as small as 25 nm that are required for negative refractive index for wavelengths in visible light spectrum of 400-700 nm and for wider view angle. Two types of metamaterial designs, three dimensional concentric split ring and fishnet, are considered. Three dimensional structures consisted of metal-dielectric-metal stacks. The metal is silver and dielectric is yttrium oxide, other than conventional materials such as FR4 and Duroid. High κ dielectric and high refractive index as well as large crystal symmetry of Yttrium oxide has been investigated as encapsulating medium. Dependence of refractive index on wavelength and bandwidth of negative refractive index region are analyzed for application towards cloaking from light in visible spectrum.

  5. Visibility of latin american scientific publications: the example of Bolivia

    Directory of Open Access Journals (Sweden)

    Silvia Cristina Pabón Escobar

    2006-06-01

    Full Text Available The discussion on the state of the art of scientific publications in Latin American countries generally restricts itself to its supposedly low visibility. This affirmation is generally conditioned to the exclusive use of large international databases, mainly of the USA and Europe, which include thousands of scientific publications that have marginalized a large part of the scientific literature produced in peripheral countries. Given this fact of low visibility, it became imperative for some Latin American countries, beginning in the 90s (20th Century, to develop their own mechanisms of projection of the results of their own scientific production. The experiences constitute an example for countries that, having significant scientific production, still do not have the means to facilitate access to local scientific publications. Although Bolivia still remains distant from these initiatives, a series of studies were identified that show the existence of a tradition of publication in scientific magazines and interest in their visibility, on a local and international level, which demands attention to the most adequate mechanisms in order to carry this out.

  6. The High-ORbit Ultraviolet-visible Satellite, HORUS

    Science.gov (United States)

    Scowen, Paul A.; Cooke, Brian; Beasley, Matthew; Siegmund, Oswald

    2013-09-01

    The High-ORbit Ultraviolet-visible Satellite (HORUS) is a 2.4-meter class space telescope that will conduct a comprehensive and systematic study of the astrophysical processes and environments relevant for the births and life cycles of stars and their planetary systems, to investigate and understand the range of environments, feedback mechanisms, and other factors that most affect the outcome of the star and planet formation process. HORUS will provide 100× greater imaging efficiency and combines the resolution of STIS with the throughput of COS. The HORUS mission will contribute vital information on how solar systems form and whether habitable planets should be common or rare. It also will investigate the structure, evolution, and destiny of galaxies and the universe. This program relies on focused capabilities unique to space that no other planned NASA mission will provide: near-ultraviolet (UV)/visible (200-1100nm) wide-field (14' square), diffraction-limited imaging; and high-sensitivity, high-resolution FUV (100- 320nm) spectroscopy. From its baseline orbit at L2 HORUS will enjoy a stable environment for thermal and pointing control, and long-duration target visibility. The core HORUS design will provide wide field of view imagery and high efficiency point source far-ultraviolet (FUV) spectroscopy using a combination of spectral selection and field sharing.

  7. Visibility to discern local from nonlocal dynamic processes

    Science.gov (United States)

    Brú, A.; Gómez-Castro, D.; Nuño, J. C.

    2017-04-01

    We compare using visibility the usual Kardar-Parisi-Zhang (KPZ) universality class and a fractional Edward-Wilkinson (EWf) equation with correlated noise, which share the same kinetic roughening exponents. The KPZ universality class is described by an equation in terms of the usual derivatives, uncorrelated noise and therefore is intrinsically local. The second model includes fractional powers of the Laplace operator and correlated noise, both of which are nonlocal. From their scaling properties, one could be tempted to conclude that both dynamics belong to the same universality class, specifically, to the KPZ universality class. However, this is a wrong conclusion that calls the attention against the indiscriminate application of this approach in real systems without taking into consideration basic physical assumptions (e.g. locality). These examples reveal the necessity of finding new algorithms for detecting characteristics that remain unnoticed to classical scaling analysis, where only the two first moments of the interface distribution (mean and variance) are used to classify the dynamics. We show that visibility and, in particular, the kinetic roughening exponents of the visibility interface, are able to distinguish between these two dynamics which are confused by standard techniques.

  8. Visible Human Slice Web Server: a first assessment

    Science.gov (United States)

    Hersch, Roger D.; Gennart, Benoit A.; Figueiredo, Oscar; Mazzariol, Marc; Tarraga, Joaquin; Vetsch, S.; Messerli, Vincent; Welz, R.; Bidaut, Luc M.

    1999-12-01

    The Visible Human Slice Server started offering its slicing services at the end of June 1998. From that date until the end of May, more than 280,000 slices were extracted from the Visible Man, by layman interested in anatomy, by students and by specialists. The Slice Server is based one Bi-Pentium PC and 16 disks. It is a scaled down version of a powerful parallel server comprising 5 Bi-Pentium Pro PCs and 60 disks. The parallel server program was created thanks to a computer-aided parallelization framework, which takes over the task of creating a multi-threaded pipelined parallel program from a high-level parallel program description. On the full blown architecture, the parallel program enables the extraction and resampling of up to 5 color slices per second. Extracting 5 slice/s requires to access the disks and extract subvolumes of the Visible Human at an aggregate throughput of 105 MB/s. The publicly accessible server enables to extract slices having any orientation. The slice position and orientation can either be specified for each slice separately or as a position and orientation offered by a Java applet and possible future improvements. In the very near future, the Web Slice Server will offer additional services, such as the possibility to extract ruled surfaces and to extract animations incorporating slices perpendicular to a user defined trajectory.

  9. All-fiber femtosecond Cherenkov laser at visible wavelengths

    DEFF Research Database (Denmark)

    Liu, Xiaomin; Lægsgaard, Jesper; Møller, Uffe Visbech

    2013-01-01

    electrically tunable femtosecond CR output in the visible (VIS) spectral range of 580-630 nm, with the 3 dB spectral bandwidth not exceeding 36 nm, with average power in the milliwatt range. Relative intensity noise (RIN) of this laser, affecting the sensitivity of bio-imaging and microscopy systems, is found...... to be as low as -103 dBc/Hz. This is 2 orders of magnitudes lower noise as compared to spectrally-sliced supercontinuum, which is the current standard of ultrafast fiber-optic generation at visible wavelength. The layout of the laser system is shown in Fig. 1(a). The system consists of two parts: an all...... fibers are used in the CR link to enhance the conversion efficiency. Fig. 1(b) shows the far-field saturated visible images of the CR emitted from the laser system, generated as the pump power increases in the range 150 mW - 300 mW. The emitted CR spectra corresponding to different average output powers...

  10. A rare pediatric case of grossly dilated ureter presenting as abdominal mass.

    Science.gov (United States)

    Srivastava, Madhur Kumar; Govindarajan, Krishna Kumar; Chakkalakkoombil, Sunitha Vellathussery; Halanaik, Dhanapathi

    2016-01-01

    Renal masses account for 55% of cases presenting as palpable abdominal mass in children.[1] An eight year male presented with palpable abdominal mass and pain. The patient underwent renal dynamic scan, which raised possibility of left duplex kidney with non-functioning moiety, as the size of left kidney was smaller than seen on Ultrasonography (USG). Magnetic resonance (MR)urography confirmed the findings with patient undergoing left hemi-nephrectomy and is doing well. In case of discrepancy in size of kidney on USG and renal scan, duplex kidney should be considered as differential, other causes being, renal cyst, benign/malignant mass and renal calculi. Gross hydro-ureter presenting as palpable abdominal mass is very rare with few reported cases.[234].

  11. Automated robust registration of grossly misregistered whole-slide images with varying stains

    Science.gov (United States)

    Litjens, G.; Safferling, K.; Grabe, N.

    2016-03-01

    Cancer diagnosis and pharmaceutical research increasingly depend on the accurate quantification of cancer biomarkers. Identification of biomarkers is usually performed through immunohistochemical staining of cancer sections on glass slides. However, combination of multiple biomarkers from a wide variety of immunohistochemically stained slides is a tedious process in traditional histopathology due to the switching of glass slides and re-identification of regions of interest by pathologists. Digital pathology now allows us to apply image registration algorithms to digitized whole-slides to align the differing immunohistochemical stains automatically. However, registration algorithms need to be robust to changes in color due to differing stains and severe changes in tissue content between slides. In this work we developed a robust registration methodology to allow for fast coarse alignment of multiple immunohistochemical stains to the base hematyoxylin and eosin stained image. We applied HSD color model conversion to obtain a less stain color dependent representation of the whole-slide images. Subsequently, optical density thresholding and connected component analysis were used to identify the relevant regions for registration. Template matching using normalized mutual information was applied to provide initial translation and rotation parameters, after which a cost function-driven affine registration was performed. The algorithm was validated using 40 slides from 10 prostate cancer patients, with landmark registration error as a metric. Median landmark registration error was around 180 microns, which indicates performance is adequate for practical application. None of the registrations failed, indicating the robustness of the algorithm.

  12. A grossly abnormal trachea- severe tracheal diverticulosis and Mounier-Kuhn syndrome.

    Science.gov (United States)

    Lyons, O D; Gilmartin, J J

    2014-03-01

    A 53-year-old smoker presented with a history of recurrent lower respiratory tract infections. A diagnosis of Tracheal Diverticulosis due to Tracheobronchomegaly (Mounier-Kuhn Syndrome) was made. The clinical history, diagnosis and treatment options are discussed.

  13. Time-Dependent Effects of Chlorhexidine Soaks on Grossly Contaminated Bone

    Science.gov (United States)

    2012-10-01

    leads to a disproportionately large increase of bacterial colonization on allograft surfaces.1 Additionally, bacteria that are present on reimplanted...remove adherent bacteria from bone. J Bone Joint Surg Am. 2001;83-A:412 419. 21. Soyer J, Rouil M, Castel O. The effect of 10% povidone iodine solution...tendon autografts using 10% povidone iodine solution. Orthopedics. 1999;22:601 604. 23. Burd T, Conroy BP, Meyer SC, et al. The effects of chlorhexidine

  14. Robust Canonical Time Warping for the Alignment of Grossly Corrupted Sequences

    NARCIS (Netherlands)

    Panagakis, Y.; Nicolaou, M.; Zafeiriou, S.; Pantic, M.

    2013-01-01

    Temporal alignment of human behaviour from visual data is a very challenging problem due to a numerous reasons, including possible large temporal scale differences, inter/intra subject variability and, more importantly, due to the presence of gross errors and outliers. Gross errors are often in abun

  15. Chloroquine is grossly overdosed and overused but well tolerated in Guinea-Bissau

    DEFF Research Database (Denmark)

    Ursing, Johan; Kofoed, Poul-Erik; Rodrigues, Amabelia;

    2009-01-01

    -Bissau are taken or whether they cause adverse effects. We aimed to determine the dosage of chloroquine commonly prescribed, the doses commonly taken and if there were concentration dependent adverse events in routine practice. Chloroquine prescriptions by 8 physicians and chloroquine intake by 102 children were...... recorded. Chloroquine intake and adverse events were assessed by questioning. Chloroquine concentrations were measured in whole blood. The median total chloroquine dose prescribed and that reportedly taken was 81 and 77 mgkg(-1) respectively. The total dose was usually split into 2-3 daily doses of 6...... in the blood at the time of diagnosis and treatment. No severe adverse events were reported. No adverse events were associated with higher chloroquine concentrations. High doses of chloroquine are commonly taken and well tolerated in Guinea-Bissau. Malaria diagnostics are poor and chloroquine is commonly...

  16. Preliminary results of algorithms to determine horizontal and vertical underwater visibilities of coastal waters

    Digital Repository Service at National Institute of Oceanography (India)

    Suresh, T.; Joshi, Shreya; Talaulikar, M.; Desa, E.J.

    Algorithms developed for underwater horizontal and vertical visibilities are presented. The algorithms have been developed to derive the underwater visibilities based on the contrast theory using the in-situ and Hydrolight derived optical parameters...

  17. Retrieval of Atmospheric Horizontal Visibility by Statistical Regression from NOAA/AVHRR Satellite Data

    Institute of Scientific and Technical Information of China (English)

    HUANG Fei; WANG Hong; QIAN Junping; WANG Guofu

    2006-01-01

    Based on the atmospheric horizontal visibility data from forty-seven observational stations along the eastern coast of China near the Taiwan Strait and simultaneous NOAA/AVHRR multichannel satellite data during January 2001 to December 2002, the spectral characters associated with visibility were investigated.Successful retrieval of visibility from multichannel NOAA/AVHRR data was performed using the principal component regression (PCR) method.A sample of retrieved visibility distribution was discussed with a sea fog process.The correlation coefficient between the observed and retrieved visibility was about 0.82, which is far higher than the 99.9% confidence level by statistical test.The rate of successful retrieval is 94.98% of the 458 cases during 2001- 2002.The error distribution showed that high visibilities were usually under-estimated and low visibilities were over-estimated and the relative error between the observed and retrieved visibilities was about 21.4%.

  18. Estimation of visibility of phase contrast with extraction voltages for field emission gun electron microscopes.

    Science.gov (United States)

    Meng, Xing

    2017-02-01

    Estimation was made for visibility of phase contrast with varying extraction voltages. The resulting decay rates of visibility show that images with low image contrast from cryo EM will be seriously impacted with high extraction voltages.

  19. Visibility in magnetostrictive fiber-optic interferometric sensors and its dependence on the input SOP

    Institute of Scientific and Technical Information of China (English)

    Changhai Shi; Jianping Chen; Xinwan Li; Ailun Ye; Junhe Zhou; Yi Zhang; Qing Xue; Lin Hong

    2006-01-01

    The visibility in magnetostrictive fiber-optic interferometric sensors using a Gaussian laser beam is analyzed. It is shown that the conventional Gaussian laser beam has little influence on the visibility. The visibility depends strongly on the input state of polarization (SOP). We implement a cylindrical transducer and build a measurement setup with a polarization controller. The visibility dependent on the SOP of input light is measured. The estimated values are similar to the experiment results, which verifies the analysis.

  20. Endobronchial valves in severe emphysematous patients: CT evaluation of lung fissures completeness, treatment radiological response and quantitative emphysema analysis Valvas endobrônquicas em pacientes com enfisema grave: avaliação por TC da completude das fissuras pulmonares, resposta radiológica ao tratamento e análise quantitativa do enfisema

    Directory of Open Access Journals (Sweden)

    Marcel Koenigkam-Santos

    2013-02-01

    Full Text Available OBJECTIVE: To evaluate lung fissures completeness, post-treatment radiological response and quantitative CT analysis (QCTA in a population of severe emphysematous patients submitted to endobronchial valves (EBV implantation. MATERIALS AND METHODS: Multi-detectors CT exams of 29 patients were studied, using thin-section low dose protocol without contrast. Two radiologists retrospectively reviewed all images in consensus; fissures completeness was estimated in 5% increments and post-EBV radiological response (target lobe atelectasis/volume loss was evaluated. QCTA was performed in pre and post-treatment scans using a fully automated software. RESULTS: CT response was present in 16/29 patients. In the negative CT response group, all 13 patients presented incomplete fissures, and mean oblique fissures completeness was 72.8%, against 88.3% in the other group. QCTA most significant results showed a reduced post-treatment total lung volume (LV (mean 542 ml, reduced EBV-submitted LV (700 ml and reduced emphysema volume (331.4 ml in the positive response group, which also showed improved functional tests. CONCLUSION: EBV benefit is most likely in patients who have complete interlobar fissures and develop lobar atelectasis. In patients with no radiological response we observed a higher prevalence of incomplete fissures and a greater degree of incompleteness. The fully automated QCTA detected the post-treatment alterations, especially in the treated lung analysis.OBJETIVO: Avaliar a completude das fissuras, resposta radiológica ao tratamento e análise quantitativa por TC (AQTC em população de pacientes com enfisema grave submetidos ao implante de valvas endobrônquicas (VEB. MATERIAIS E MÉTODOS: Foram estudados exames de TC multidetectores de 29 pacientes, realizados com protocolo de baixo dose, cortes finos, sem contraste. Dois radiologistas revisaram, retrospectivamente, os exames em consenso. A completude das fissuras foi estimada em escala de 5% e

  1. Cloud Computing Infusion for Generating ESDRs of Visible Spectra Radiances

    Science.gov (United States)

    Golpayegani, N.; Halem, M.; Nguyen, P.

    2008-12-01

    The AIRS and AVHRR instruments have been collecting radiances of the Earth in the visible spectrum for over 25 years. These measurements have been used to develop such useful products as NDVI, Snow cover and depth, Outgoing long wave radiation and other products. Yet, no long-term data record of the level 1b visible spectra is available in a grid form to researchers for various climate studies. We present here an Earth System Data Record observed in the visible spectrum as gridded radiance fields of 8kmx10km grid resolution for the six years in the case of AIRS and from 1981 to the present for AVHRR. The AIRS data has four visible channels from 0.41μm to 0.94μm with an IFOV of 1 km and AVHRR has two visible channels in the 0.58μm to 1.00μm range also at 1 km. In order to process such large amounts of data on demand, two components need to be implemented,(i) a processing system capable of gridding TBs of data in a reasonable amount of time and (ii) a download mechanism to access and deliver the data to the processing system. We implemented a cloud computing approach to be able to process such large amounts of data. We use Hadoop, a distributed computation system developed by the Apache Software Foundation. With Hadoop, we are able to store the data in a distributed fashion, taking advantage of Hadoop's distributed file system (dfs). We also take advantage of Hadoop's MapReduce functionality to perform as much computations as is possible on available nodes of the UMBC bluegrit Cell cluster system that contain the data. We make use of the SOAR system developed under the ACCESS program to acquire and process the AIRS and AVHRR observations. Comparisons of the AIRS data witth selected periods of MODIS visible spectral channels on the same sattelite indicate the two instruments have maintained calibration consistency and continuity of their measurements over the six year period. Our download mechanism transfers the data from these instruments into hadoop's dfs. Our

  2. Probing Below the Visible Cloud Layers in Jupiter's Atmosphere

    Science.gov (United States)

    de Pater, Imke; Sault, Robert J.; Butler, Bryan J.; DeBoer, David R.; Wong, Michael H.

    2016-10-01

    Visible and near-infrared images of the giant planets reveal a multitude of clouds, ranging in size from tiny, hardly visible, features to giant storm systems, such as Jupiter's Great Red Spot and Oval BA. At radio wavelengths we can probe altitudes in Jupiter's atmosphere below these visible cloud layers. We used the upgraded Very Large Array to map this unexplored region down to ~10 bar. We will present full radio maps at frequencies between 4 and ~35 GHz, with typical spatial resolutions of order 1000-2000 km. We will also show spectra and radiative transfer calculations of individual features, such as the Great Red Spot, Oval BA, hot spots and ammonia-rich "plumes". Our maps are complementary to observations planned for Juno's microwave radiometer (MWR). MWR's field-of-view is tiny, ~1000 km at the highest frequencies at perijove, and is limited to extremely narrow swaths of longitude; as such, our VLA maps will provide regional and global context at wavelengths overlapping with Juno MWR. Several maps at 8-12 GHz, at a spatial resolution of ~1000 km, will be taken during Juno perijove passes.Our analysis to date, based on 4-18 GHz maps, reveal a dynamically active planet at pressures up ammonia gas from Jupiter's deep atmosphere in "plumes", at concentrations similar to that measured by the Galileo Probe. At higher altitudes, the ammonia gas in these plumes will condense out, and as such could be responsible for the spectroscopically identified fresh ammonia ice clouds detected by the Galileo spacecraft at these latitudes.

  3. Adaptive fusion of infrared and visible images in dynamic scene

    Science.gov (United States)

    Yang, Guang; Yin, Yafeng; Man, Hong; Desai, Sachi

    2011-11-01

    Multiple modalities sensor fusion has been widely employed in various surveillance and military applications. A variety of image fusion techniques including PCA, wavelet, curvelet and HSV has been proposed in recent years to improve human visual perception for object detection. One of the main challenges for visible and infrared image fusion is to automatically determine an optimal fusion strategy for different input scenes along with an acceptable computational cost. This paper, we propose a fast and adaptive feature selection based image fusion method to obtain high a contrast image from visible and infrared sensors for targets detection. At first, fuzzy c-means clustering is applied on the infrared image to highlight possible hotspot regions, which will be considered as potential targets' locations. After that, the region surrounding the target area is segmented as the background regions. Then image fusion is locally applied on the selected target and background regions by computing different linear combination of color components from registered visible and infrared images. After obtaining different fused images, histogram distributions are computed on these local fusion images as the fusion feature set. The variance ratio which is based on Linear Discriminative Analysis (LDA) measure is employed to sort the feature set and the most discriminative one is selected for the whole image fusion. As the feature selection is performed over time, the process will dynamically determine the most suitable feature for the image fusion in different scenes. Experiment is conducted on the OSU Color-Thermal database, and TNO Human Factor dataset. The fusion results indicate that our proposed method achieved a competitive performance compared with other fusion algorithms at a relatively low computational cost.

  4. Asymmetric photoredox transition-metal catalysis activated by visible light

    Science.gov (United States)

    Huo, Haohua; Shen, Xiaodong; Wang, Chuanyong; Zhang, Lilu; Röse, Philipp; Chen, Liang-An; Harms, Klaus; Marsch, Michael; Hilt, Gerhard; Meggers, Eric

    2014-11-01

    Asymmetric catalysis is seen as one of the most economical strategies to satisfy the growing demand for enantiomerically pure small molecules in the fine chemical and pharmaceutical industries. And visible light has been recognized as an environmentally friendly and sustainable form of energy for triggering chemical transformations and catalytic chemical processes. For these reasons, visible-light-driven catalytic asymmetric chemistry is a subject of enormous current interest. Photoredox catalysis provides the opportunity to generate highly reactive radical ion intermediates with often unusual or unconventional reactivities under surprisingly mild reaction conditions. In such systems, photoactivated sensitizers initiate a single electron transfer from (or to) a closed-shell organic molecule to produce radical cations or radical anions whose reactivities are then exploited for interesting or unusual chemical transformations. However, the high reactivity of photoexcited substrates, intermediate radical ions or radicals, and the low activation barriers for follow-up reactions provide significant hurdles for the development of efficient catalytic photochemical processes that work under stereochemical control and provide chiral molecules in an asymmetric fashion. Here we report a highly efficient asymmetric catalyst that uses visible light for the necessary molecular activation, thereby combining asymmetric catalysis and photocatalysis. We show that a chiral iridium complex can serve as a sensitizer for photoredox catalysis and at the same time provide very effective asymmetric induction for the enantioselective alkylation of 2-acyl imidazoles. This new asymmetric photoredox catalyst, in which the metal centre simultaneously serves as the exclusive source of chirality, the catalytically active Lewis acid centre, and the photoredox centre, offers new opportunities for the `green' synthesis of non-racemic chiral molecules.

  5. A practical grading system of ultrasonographic visibility for intracerebral lesions.

    Science.gov (United States)

    Mair, Richard; Heald, James; Poeata, Ion; Ivanov, Marcel

    2013-12-01

    Intraoperative ultrasound for intracranial neurosurgery was largely abandoned in the 1980s due to poor image resolution. Despite many technological advances in ultrasound since then, the use of this imaging modality in contemporary practice remains limited. Our aim was to evaluate the utility of modern intraoperative ultrasound in the resection of a wide variety of intracranial pathologies. A total of 105 patients who underwent intracranial lesion resection in a contiguous fashion were prospectively included in the study. Ultrasound images acquired intraoperatively were used to stratify lesions into one of four grades (grades 0-3) on the basis of their ultrasonic echogenicity and border visibility. Forty-two out of 105 lesions (40 %) were clearly identifiable and had a clear border with normal tissue (grade 3). Fifty-five of 105 lesions (52 %) were clearly identifiable but had no clear border with normal tissue (grade 2). Eight of 105 lesions (8 %) were difficult to identify and had no clear border with normal tissue (grade 1). None (0 %) of the lesions could not be identified (grade 0). High-grade gliomas, cerebral metastases, meningiomas, ependymomas, and haemangioblastomas all demonstrated a median ultrasonic visibility grade of 2 or greater. Low-grade astrocytomas and oligodendrogliomas demonstrated a median ultrasonic visibility grade of 2 or less. Intraoperative ultrasound can be of tremendous benefit in allowing the surgeon to appraise the location, extent, and local environment of their target lesion, as well as to reduce the risk of preventable complications. We believe that our grading system will provide a useful adjunct to the neurosurgeon when deciding for which lesions intraoperative ultrasound would be useful.

  6. Continental Fog Attenuation Empirical Relationship from Measured Visibility Data

    Directory of Open Access Journals (Sweden)

    F. Nadeem

    2010-12-01

    Full Text Available Free Space Optics (FSO has the great potential for future communication applications. However, weather influenced reduced availability had been the main cause for its restricted growth. Among different weather influences fog plays the major role. A new model generalized for all FSO wavelengths, has been proposed for the prediction of continental fog attenuation using visibility data. The performance of the proposed model has been compared with well known models for measured attenuation data of Continental fog. The comparison has been performed in terms of Root Mean Square Error (RMSE.

  7. Visible Light Communication System Using an Organic Bulk Heterojunction Photodetector

    Directory of Open Access Journals (Sweden)

    Cristina de Dios

    2013-09-01

    Full Text Available A visible light communication (VLC system using an organic bulk heterojunction photodetector (OPD is presented. The system has been successfully proven indoors with an audio signal. The emitter consists of three commercial high-power white LEDs connected in parallel. The receiver is based on an organic photodetector having as active layer a blend of poly(3-hexylthiophene (P3HT and phenyl C61-butyric acid methyl ester (PCBM. The OPD is opto-electrically characterized, showing a responsivity of 0.18 A/W and a modulation response of 790 kHz at −6 V.

  8. Performance Analysis of Visible Light Communication Using CMOS Sensors

    Directory of Open Access Journals (Sweden)

    Trong-Hop Do

    2016-02-01

    Full Text Available This paper elucidates the fundamentals of visible light communication systems that use the rolling shutter mechanism of CMOS sensors. All related information involving different subjects, such as photometry, camera operation, photography and image processing, are studied in tandem to explain the system. Then, the system performance is analyzed with respect to signal quality and data rate. To this end, a measure of signal quality, the signal to interference plus noise ratio (SINR, is formulated. Finally, a simulation is conducted to verify the analysis.

  9. Resource allocation for multichannel broadcasting visible light communication

    Science.gov (United States)

    Le, Nam-Tuan; Jang, Yeong Min

    2015-11-01

    Visible light communication (VLC), which offers the possibility of using light sources for both illumination and data communications simultaneously, will be a promising incorporation technique with lighting applications. However, it still remains some challenges especially coverage because of field-of-view limitation. In this paper, we focus on this issue by suggesting a resource allocation scheme for VLC broadcasting system. By using frame synchronization and a network calculus QoS approximation, as well as diversity technology, the proposed VLC architecture and QoS resource allocation for the multichannel-broadcasting MAC (medium access control) protocol can solve the coverage limitation problem and the link switching problem of exhibition service.

  10. Visible luminescence from triethanolamine-modified zinc oxide nanoparticles

    Science.gov (United States)

    Karak, N.; Barik, P.; Kundu, T. K.

    2013-06-01

    We report sol-gel synthesis of ZnO NPs in support of Triethanolamine (TEA) molecules. The particle sizes lie in the range of 23 nm - 43 nm. The blue-shift in absorption spectra for all powders is attributed to the quantum confinement effect. ZnO nanopowder annealed at higher temperature shows an enhanced visible luminescence. In comparison, ZnO specimens having large grain size which are prepared without using TEA do not show any emission with significant intensity. An energy band diagram of nanostructured ZnO specimens explains the luminescence results.

  11. Visible light communication: Applications, architecture, standardization and research challenges

    Directory of Open Access Journals (Sweden)

    Latif Ullah Khan

    2017-05-01

    Full Text Available The Radio Frequency (RF communication suffers from interference and high latency issues. Along with this, RF communication requires a separate setup for transmission and reception of RF waves. Overcoming the above limitations, Visible Light Communication (VLC is a preferred communication technique because of its high bandwidth and immunity to interference from electromagnetic sources. The revolution in the field of solid state lighting leads to the replacement of florescent lamps by Light Emitting Diodes (LEDs which further motivates the usage of VLC. This paper presents a survey of the potential applications, architecture, modulation techniques, standardization and research challenges in VLC.

  12. EUV and Visible Spectroscopy of Promethiumlike Heavy Ions

    CERN Document Server

    Kobayashi, Yusuke; Omote, Kazuki; Komatsu, Akihiro; Sakoda, Junpei; Minoshima, Maki; Kato, Daiji; Li, Jiguang; Sakaue, Hiroyuki A; Murakami, Izumi; Nakamura, Nobuyuki

    2015-01-01

    We present extreme ultraviolet and visible spectra of promethiumlike tungsten and gold obtained with an electron beam ion trap (EBIT). Although the contributions from a few charge states are involved in the spectra, the charge state of the ion assigned to the observed lines is definitely identified by the time-of-flight analysis of the ions performed at the same time with the spectroscopic measurements. Experimental results are compared with collisional-radiative model calculations as well as previous experimental and theoretical studies.

  13. Lunar UV-visible-IR mapping interferometric spectrometer

    Science.gov (United States)

    Smith, W. Hayden; Haskin, L.; Korotev, R.; Arvidson, R.; Mckinnon, W.; Hapke, B.; Larson, S.; Lucey, P.

    1992-01-01

    Ultraviolet-visible-infrared mapping digital array scanned interferometers for lunar compositional surveys was developed. The research has defined a no-moving-parts, low-weight and low-power, high-throughput, and electronically adaptable digital array scanned interferometer that achieves measurement objectives encompassing and improving upon all the requirements defined by the LEXSWIG for lunar mineralogical investigation. In addition, LUMIS provides a new, important, ultraviolet spectral mapping, high-spatial-resolution line scan camera, and multispectral camera capabilities. An instrument configuration optimized for spectral mapping and imaging of the lunar surface and provide spectral results in support of the instrument design are described.

  14. Lunar UV-visible-IR mapping interferometric spectrometer

    Science.gov (United States)

    Smith, W. Hayden; Haskin, L.; Korotev, R.; Arvidson, R.; Mckinnon, W.; Hapke, B.; Larson, S.; Lucey, P.

    1992-01-01

    Ultraviolet-visible-infrared mapping digital array scanned interferometers for lunar compositional surveys was developed. The research has defined a no-moving-parts, low-weight and low-power, high-throughput, and electronically adaptable digital array scanned interferometer that achieves measurement objectives encompassing and improving upon all the requirements defined by the LEXSWIG for lunar mineralogical investigation. In addition, LUMIS provides a new, important, ultraviolet spectral mapping, high-spatial-resolution line scan camera, and multispectral camera capabilities. An instrument configuration optimized for spectral mapping and imaging of the lunar surface and provide spectral results in support of the instrument design are described.

  15. Performance evaluation of transformer oil using uv-visible spectrophotometer

    Directory of Open Access Journals (Sweden)

    Radha Karthik

    2014-04-01

    Full Text Available To ensure reliable operation of Power transformer, condition monitoring of transformer becomes obligatory. In this paper, condition assessment of transformer oil under various working conditions is performed using UV-visible spectrophotometer. Test samples include both laboratorial prepared ones and those obtained from in service transformers.  An index table of spectral responses for various faults which predominantly occur in the transformer is developed. The index table will acts as a reference for spectral response of faulted transformer oil. In this paper, an attempt has been made to determine the quality of transformer oil using their spectral response characteristics.

  16. Negotiating mixedness/ Danishness- visibly intermarried couples in Denmark

    DEFF Research Database (Denmark)

    Singla, Rashmi

    and further development of psychosocial services for those facing problems. The presentation primarily focuses on the Danish partner among the visible ethnically mixed couples (Phoenix, 2011) bringing in the concept of racial literacy, among others inspired by the study of Swedish attitudes to intermarriage...... are challenged to deal with the society’s obsession with the ethic/ racial differences for themselves as well as their children. These dynamics, grounded in couples’ life trajectories form basis for some suggestions for relevant mental health for policy and services, combining health promotion and psychosocial...

  17. Scalable Visibility Color Map Construction in Spatial Databases

    OpenAIRE

    Choudhury, Farhana Murtaza; Ali, Mohammed Eunus; Masud, Sarah; Nath, Suman; Rabban, Ishat E

    2013-01-01

    Recent advances in 3D modeling provide us with real 3D datasets to answer queries, such as "What is the best position for a new billboard?" and "Which hotel room has the best view?" in the presence of obstacles. These applications require measuring and differentiating the visibility of an object (target) from different viewpoints in a dataspace, e.g., a billboard may be seen from two viewpoints but is readable only from the viewpoint closer to the target. In this paper, we formulate the above...

  18. A strong visible line in the spectrum of W11+

    Science.gov (United States)

    Li, M.; Qiu, M.; Xiao, J.; Yao, K.; Brage, T.; Hutton, R.; Zou, Y.

    2016-10-01

    We have investigated the visible spectrum of W11+ and found a very strong line at the wave length of 527.61 nm from the 4f135s25p2 (2F7/2-2F5/2) transition. We show that this line is strong since the excitation energy of the upper level opens up the possibility to capture a large population. We discuss the possibility that this strong line could be the unknown line seen in charge exchange spectra recorded at the JET fusion facility.

  19. ONLINE VISIBILITY OF THE TOURISTIC SUPPLY IN SUCEAVA COUNTY

    Directory of Open Access Journals (Sweden)

    Pavel STANCIU

    2012-12-01

    Full Text Available Due to the fact that the Internet is now a media zone that tends to monopolize the entire tourist advertising, a careful analysis is required to determine its impact on the marketing activity of the tourist accommodation structures in Bucovina. The major objective of the study aims to highlight the stage development of the touristic accommodation structures in Suceava County through the online visibility filter and, implicitly, their familiarisation with the specific techniques, strategies and marketing methods of the virtual environment.

  20. Visible and Ultraviolet Spectroscopy of Gas Phase Rhodamine 575 Cations

    OpenAIRE

    Daly, Steven; Kulesza, Alexander; Knight, Geoffrey; Macaleese, Luke; Antoine, Rodolphe; Dugourd, Philippe

    2015-01-01

    International audience; The visible and ultraviolet spectroscopy of gas phase rhodamine 575 cations has been studied experimentally by action-spectroscopy in a modified linear ion trap between 220 and 590 nm and by time-dependent density functional theory (TDDFT) calculations. Three bands are observed that can be assigned to the electronic transitions S0 → S1, S0 → S3, and S0 → (S8,S9) according to the theoretical prediction. While the agreement between theory and experiment is excellent for ...

  1. The Management of Visibilities in the Digital Age

    DEFF Research Database (Denmark)

    Flyverbom, Mikkel; Leonardi, Paul; Stohl, Cynthia

    2016-01-01

    What we see, what we show and how we look are fundamental organizational concerns made ever more salient by the affordances, dynamics, and discourses of the digital age. Contemporary organizing practices are awash with material, mediated and managed visibilities: companies erect glass buildings...... with open and networked office spaces to efficiently share information, respond to stakeholder demands by crafting extensive transparency policies, and orchestrate the massive distribution of information online in the name of accountability. At the same time, states and corporations aggregate digital traces...

  2. The Management of Visibilities in the Digital Age

    DEFF Research Database (Denmark)

    Flyverbom, Mikkel; Leonardi, Paul; Stohl, Cynthia;

    2016-01-01

    What we see, what we show and how we look are fundamental organizational concerns made ever more salient by the affordances, dynamics, and discourses of the digital age. Contemporary organizing practices are awash with material, mediated and managed visibilities: companies erect glass buildings...... with open and networked office spaces to efficiently share information, respond to stakeholder demands by crafting extensive transparency policies, and orchestrate the massive distribution of information online in the name of accountability. At the same time, states and corporations aggregate digital traces...

  3. The Application of 3-D Visible Technology to Reservoir Management

    Institute of Scientific and Technical Information of China (English)

    Yu Long; LIU Tao

    2002-01-01

    The paper deals with the application of 3 -D visible technology to reservoir management. Making use of this method for expanding - spread data point in reservoir management, can discard the false and retain the true during data recording. As a result, The quality of data recording is ensured. In reservoir description, the reservoir characteristics, such as space distribution,physical change and fluid distribution may be identified by restoring palaeostructures, building - up 3-D facics tract model and 3-D fracture system model. Seismic interpretation, geologic modeling and numerical simulation are well integrated so that they can be promote reservoir performance management to develop into the intensive management pattern.

  4. Low reheating temperature and the visible sterile neutrino.

    Science.gov (United States)

    Gelmini, Graciela; Palomares-Ruiz, Sergio; Pascoli, Silvia

    2004-08-20

    We present here a scenario, based on a low reheating temperature T(R)inflation, in which the coupling of sterile neutrinos to active neutrinos can be as large as experimental bounds permit (thus making this neutrino "visible" in future experiments). In previous models this coupling was forced to be very small to prevent a cosmological overabundance of sterile neutrinos. Here the abundance depends on how low the reheating temperature is. For example, the sterile neutrino required by the Liquid Scintillator Neutrino Detector result may not have any cosmological problem within our scenario.

  5. 14 GHz visible supercontinuum generation: calibration sources for astronomical spectrographs.

    Science.gov (United States)

    Stark, S P; Steinmetz, T; Probst, R A; Hundertmark, H; Wilken, T; Hänsch, T W; Udem, Th; Russell, P St J; Holzwarth, R

    2011-08-15

    We report the use of a specially designed tapered photonic crystal fiber to produce a broadband optical spectrum covering the visible spectral range. The pump source is a frequency doubled Yb fiber laser operating at a repetition rate of 14 GHz and emitting sub-5 pJ pulses. We experimentally determine the optimum core diameter and achieve a 235 nm broad spectrum. Numerical simulations are used to identify the underlying mechanisms and explain spectral features. The high repetition rate makes this system a promising candidate for precision calibration of astronomical spectrographs.

  6. High-Visibility Photonic Crystal Fiber Interferometer as Multifunctional Sensor

    Directory of Open Access Journals (Sweden)

    Joel Villatoro

    2013-02-01

    Full Text Available A photonic crystal fiber (PCF interferometer that exhibits record fringe contrast (~40 dB is demonstrated along with its sensing applications. The device operates in reflection mode and consists of a centimeter-long segment of properly selected PCF fusion spliced to single mode optical fibers. Two identical collapsed zones in the PCF combined with its modal properties allow high-visibility interference patterns. The interferometer is suitable for refractometric and liquid level sensing. The measuring refractive index range goes from 1.33 to 1.43 and the maximum resolution is ~1.6 × 10−5.

  7. Increasing the visibility of thin NITINOL vascular implants

    Directory of Open Access Journals (Sweden)

    Boese A.

    2015-09-01

    Full Text Available New implants for vascular therapy like flow diverters are made of tiny braided wires. The radio opacity of these wires is poor, which makes assessment of implant expansion and exact positioning difficult. Additional markers only allow the estimation of the current device position, but they also induce artefacts that impair the assessment during the intervention and in follow-up examination. A new strategy to increase implant visibility is the braiding of composite wires with a radiopaque core along the whole implant. This paper shows some useful combinations of these new wires on a phantom study with five vascular implants.

  8. Effects of Visible Light on Cultured Bovine Trabecular Cells

    Institute of Scientific and Technical Information of China (English)

    姜发纲; 郝风芹; 魏厚仁; 许德胜

    2004-01-01

    To explore the biological effects of light on trabecular cells, cultured bovine trabecular cells were exposed to visible light of different wavelength with different energy. Cellular morphology, structure, proliferation, and phagocytosis were observed. The cells showed no remarkable changes when the energy was low. When the exposure energy reached 1. 12 mW/cm2 , the cytoplasm showed a rough appearance, and cell proliferation and phagocytosis decreased. This phototoxicity was strong with white light (compound chromatic light), moderate with violet light or yellow light, and mild with red light.

  9. Performance comparison of binary modulation schemes for visible light communication

    KAUST Repository

    Park, Kihong

    2015-09-11

    In this paper, we investigate the power spectral density of several binary modulation schemes including variable on-off keying, variable pulse position modulation, and pulse dual slope modulation which were previously proposed for visible light communication with dimming control. We also propose a novel slope-based modulation called differential chip slope modulation (DCSM) and develop a chip-based hard-decision receiver to demodulate the resulting signal, detect the chip sequence, and decode the input bit sequence. We show that the DCSM scheme can exploit spectrum density more efficiently than the reference schemes while providing an error rate performance comparable to them. © 2015 IEEE.

  10. Visible light scatter as quantitative information source on milk constituents

    DEFF Research Database (Denmark)

    Melentieva, Anastasiya; Kucheryavskiy, Sergey; Bogomolov, Andrey

    2012-01-01

    -time monitoring of processes and products. Optical analysis is generally performed in near and middle infrared (NIR and MIR) regions and relies on the component absorbance and Beer’s Law. The light scatter effect is therefore considered as a disturbance to be avoided during the measurement or eliminated...... at the data analysis stage. The region of visible (Vis) light (400-800 nm) is economically attractive, because it offers a range of inexpensive light sources, optics and detectors. At present, however, it is commonly considered useless, because of the light scatter by fat globules (1-10 μm) and protein...

  11. Diffusion Law of Smoke in Visible Light and Infrared Wavebands

    Institute of Scientific and Technical Information of China (English)

    ZHU Chen-guang; PAN Gong-pei; WU Xiao-yun; QIAN Zhi-hua

    2005-01-01

    Obscuring time of smokescreen is an important parameter, and diffusion coefficient is a crucial parameter to the obscuring time of smokescreen. The relational equation that effective obscuring area of smoke changes with diffusion co-efficient and diffusing time was derived. And based on experimental data, the parabolas that the area changes with time are drawn, and the relation between diffusion coefficient and obscuring time of smoke-screen is analyzed. Diffusion coefficients of smoke cloud in the infrared (IR) and in the visible light are compared with, the two-phase flow character of aerosol particle is found while diffusing in the two wavebands. And their differences are analyzed in detail.

  12. CASE REPORT CASE Emphysematous pyelonephritis in a patient ...

    African Journals Online (AJOL)

    Abstract. A case report demonstrating the plain film and CT find- ... history of frank haematuria, severe lower back ache, diarrhoea and ... Plain radiographs of the chest and abdomen showed an elevated left ... Stellenbosch University. Fig 1.

  13. Emphysematous pyometra in a bitchPiometra enfisematosa em cadela

    Directory of Open Access Journals (Sweden)

    Fábio Mitsuo Miyashita

    2011-08-01

    Full Text Available Dogs that show an increase in abdominal size are common in clinical routine of pets and pose challenges for the diagnosis. Among these problems is pyometra, which may be due to bacterial contamination, mainly originating from the vagina in estrus period. We report the case of a female dog, pinscher, young adult, with a history of heat for about 25 days and progressive abdominal enlargement for about 20 days. In the percussion sounds are detected abdominal tympanic. There was leukocytosis with a left shift and a tubular structure distended with gas inside was evident in abdominal radiographs. At exploratory celiotomy uterine horns were increased and with gaseous and liquid content inside. Therefore, ovariohysterectomy was done. The content of uterine fluid was submitted for microbial culture, in which isolated Staphylococcus sp; cytological examination identified the gram - positive sporulated suggestive of Clostridium sp. This animal was treated postoperatively with broad-spectrum antibiotics.Cães que apresentam aumento de volume abdominal são freqüentes na rotina clínica de animais de companhia e representam desafio quanto ao diagnóstico. Dentre esses problemas, está a piometra, que pode ser resultante de contaminação bacteriana, principalmente originária da vagina no período de estro. Relata-se o caso de uma fêmea canina, pinscher, jovem adulta, com histórico de cio há aproximadamente 25 dias e aumento abdominal progressivo há cerca de 20 dias. Na percussão abdominal detectaram-se sons timpânicos. Verificou-se leucocitose com desvio a esquerda e ao exame radiográfico abdominal observou-se estrutura tubular distendida com conteúdo gasoso. Na celiotomia exploratória os cornos uterinos estavam aumentados e com conteúdo gasoso e líquido no interior. Procedeu-se, portanto, ovariohisterectomia. O conteúdo líquido uterino foi submetido a cultivo microbiano, no qual se isolou Stafilococcus sp; o exame citológico identificou bacilos gram - positivos esporulados sugestivos de Clostridium sp. Este animal foi tratado no pós-operatório com antibióticos de amplo espectro.

  14. Emphysematous Cholecystitis: A Rare Complication of Hepatitis A Virus Infection

    Directory of Open Access Journals (Sweden)

    Ahmet KARAKAS

    2015-03-01

    Full Text Available Hepatitis A virus (HAV causes an acute hepatitis associated with significant elevatation in liver enzymes. The liver is main target of HAV and extrahepatic manifestations are scarce. The diagnosis of acute HAV infection is made by the detection of anti-HAV IgM antibody in patients with the typical clinical presentation.. Here in, we present a 22-year old male presented with malaise, fever, nause, and intensive stomach ache. In physical examination, the patient had fever, jaundice, and hepatomegaly. Laboratory tests resulted in elevated liver enzymes. Abdominal ultrasonography demonstrated thickening of the gallbladder wall, and intramural air. As the patient's symptoms failed to regress in follow up laparoscopic cholecystectomy was performed. To sum up, HAV infection can be seen in all age groups, in developing countries, such as our country. It must be kept in mind that, although very rarely, HAV infections may exhibit extrahepatic complications. [Dis Mol Med 2015; 3(1.000: 5-7

  15. ‘All of a Sudden, There Are Muslims’: Visibilities and Islamophobic Violence in Canada

    Directory of Open Access Journals (Sweden)

    Barbara Perry

    2015-10-01

    Full Text Available This paper traces the meanings and impacts of the increased and transformed visibility of Muslim communities in Canada, as evidenced through their experiences of surveillance and violence. It explores the contours of this visibility as well as the consequences. Relationships between Muslims and non-Muslims are shaped in and through hostility, harassment and violence which is directed toward increasingly visible Muslim communities. Guiding the analysis of the connections between visibility and hate crime is a frame that draws upon Brighenti’s ideal types of visibility: media-type, control-type and social-type.

  16. Academic visibility for urban planning and the webometric future

    Directory of Open Access Journals (Sweden)

    Sanchez Thomas W.

    2015-03-01

    Full Text Available The author focuses on the analysis problems of the main metrics of scientific productivity for the faculty in the USA universities specializing in the investigations and teaching in the field of urban planning. The increasing role of the Internet is highlighted in the process of communicating the ideas of planning scientists to the professionals and public, extending the reach of academic communications and possibilities of estimating the quality of the investigations and impact. Using case study the methods of applying webometrics for citation analysis in the Internet are investigated. The analysis focused on the main criteria: productivity, visibility, reputation, and impact. The article proposes an expanded approach for estimating general scientific popularity and impact of academics in the Internet, which includes publication analysis in frames of “gray literature”, teaching and outreach activity, which may also be a significant part of the scientific activity. The author stated the importance of academic visibility estimation both for promotion, improving competitiveness of a faculty member on the labor market in the sphere of educational services, and for urban planning schools’ development in general, raising their reputation, prestige and impact, getting the opportunities for financed researches, consolidating the positions on the global educational and science market.

  17. Evaluation of Bi-W-oxides for visible light photocatalysis

    Energy Technology Data Exchange (ETDEWEB)

    Finlayson, A.P.; Tsaneva, V.N.; Glowacki, B.A. [Department of Materials Science and Metallurgy, University of Cambridge, Pembroke Street, Cambridge CB2 3QZ (United Kingdom); Lyons, L.; Clark, M. [Bentham Instruments Ltd, 2 Boulton Road, Reading RG2 0NH (United Kingdom)

    2006-02-01

    Photocatalytic solar water splitting has the potential to become a low-carbon source of hydrogen fuel over the coming decades if the issue of low visible light absorption can be addressed without sacrificing chemical stability. We report on an investigation into the potential of the Bi-W-oxides, Bi{sub 2}WO{sub 6} and Bi{sub 6}WO{sub 12}, as visible light photocatalysts. X-ray diffraction and Raman spectroscopy have been used to assess the structure of the oxides, whilst UV-vis diffuse reflectance spectroscopy analysed with the Kubelka-Munk function has been used to identify their optical band gaps. It has been revealed that Bi{sub 6}WO{sub 12} shows significantly higher optical absorption in the region above 440 nm than either Bi{sub 2}O{sub 3} or WO{sub 3}, raising the possibility of enhanced photocatalytic activity under solar illumination. Bi{sub 2}WO{sub 6} has a marginally lower band gap at 2.59 eV than Bi{sub 2}O{sub 3} or WO{sub 3} but the results reported herein raise doubts concerning its chemical stability under aqueous, illuminated conditions for protracted periods of time. (copyright 2006 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  18. [Authentication of Age of Bloodstains Using UV Visible Reflection Spectrum].

    Science.gov (United States)

    Gao, Qian-yu; Gao, Shi-ming

    2015-08-01

    The age of bloodstains is tightly related to the time elapsed since the crime was committed. The inference of the time that the crime was committed is of great significance to solve the case, and it was also a difficult problem in judicial authentication. Therefore, establishing a method of rapid determination of bleeding time is very necessary. Using a UV-visible spectrometer with a reflection accessory called ISR-240A and whiteboard as a reference standard, the reflection spectra of blood gauze, aluminum, glass and plastic were measured every hour under the condition of 16 °C and 70% humidity within 8 hours. Using SPSS to process the data, R541/R577 was figured out and linear fitting was completed. The same method was carried on on the gauze of blood at 24 °C. The results showed that, within 8 hours, spectral reflectance values of blood at 541 and 577 nm increased gradually with the passage of injury time. In addition to the R2 of the glass with blood is 0.769, the rest of the R2 were greater than 0.900. The values of F were greater than F0.05 (1, 6) = 5.59. Therefore, the linear regression model is significant meaningful. The method of using a UV-Visible spectrometer without doing any operations of the test samples is simple. Moreover, it does no harm to the further inspection in aspects of personal information, which is suitable for the judicial practice.

  19. An Advanced Atmospheric Dispersion Corrector: The Magellan Visible AO Camera

    CERN Document Server

    Kopon, Derek; Gasho, Victor

    2010-01-01

    In addition to the BLINC/MIRAC IR science instruments, the Magellan adaptive secondary AO system will have an EEV CCD47 that can be used both for visible AO science and as a wide-field acquisition camera. The effects of atmospheric dispersion on the elongation of the diffraction limited Magellan adaptive optics system point spread function (PSF) are significant in the near IR. This elongation becomes particularly egregious at visible wavelengths, culminating in a PSF that is 2000\\{mu}m long in one direction and diffraction limited (30-60 \\{mu}m) in the other over the wavelength band 0.5-1.0\\{mu}m for a source at 45\\pm zenith angle. The planned Magellan AO system consists of a deformable secondary mirror with 585 actuators. This number of actuators should be sufficient to nyquist sample the atmospheric turbulence and correct images to the diffraction limit at wavelengths as short as 0.7\\{mu}m, with useful science being possible as low as 0.5\\{mu}m. In order to achieve diffraction limited performance over this ...

  20. Bismuth titanate nanorods and their visible light photocatalytic properties

    Energy Technology Data Exchange (ETDEWEB)

    Pei, L.Z., E-mail: lzpei@ahut.edu.cn; Liu, H.D.; Lin, N.; Yu, H.Y.

    2015-02-15

    Highlights: • Bismuth titanate nanorods have been synthesized by a simple hydrothermal process. • The size of bismuth titanate nanorods can be controlled by growth conditions. • Bismuth titanate nanorods show good photocatalytic activities of methylene blue and Rhodamine B. - Abstract: Bismuth titanate nanorods have been prepared using a facile hydrothermal process without additives. The bismuth titanate products were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), high-resolution TEM (HRTEM) and UV-vis diffusion reflectance spectrum. XRD pattern shows that the bismuth titanate nanorods are composed of cubic Bi{sub 2}Ti{sub 2}O{sub 7} phase. Electron microscopy images show that the length and diameter of the bismuth titanate nanorods are 50-200 nm and 2 μm, respectively. Hydrothermal temperature and reaction time play important roles on the formation and size of the bismuth titanate nanorods. UV-vis diffusion reflectance spectrum indicates that bismuth titanate nanorods have a band gap of 2.58 eV. The bismuth titanate nanorods exhibit good photocatalytic activities in the photocatalytic degradation of methylene blue (MB) and Rhodamine B (RB) under visible light irradiation. The bismuth titanate nanorods with cubic Bi{sub 2}Ti{sub 2}O{sub 7} phase are a promising candidate as a visible light photocatalyst.

  1. MODEL CAR TRAFFIC ON SECTIONS OF ROADS WITH LIMITED VISIBILITY

    Directory of Open Access Journals (Sweden)

    A. V. Skrypnikov

    2014-01-01

    Full Text Available Summary. Existing theoretical calculations speeds in areas of horizontal and vertical curves designed for the needs of construction and calculation of cars and can not be used for valuation. When calculating the value of the coefficient of friction velocity determined at full wheel lock that does not correspond to the actual conditions of braking stability conditions of the car within its lane. The article proposes to calculate the permissible vehicle speed for the sites of horizontal and vertical curves on forest roads from the requirement car stop within the zone of visibility without buckling considering assumptions: during braking movement remains manageable, the driver keeps the car in the outside lane; magnitude of the angular velocity of the steering wheel is small; fully utilized inhibitory properties least loaded wheel; cornering power coefficient of resistance of tires depends little on the change of loads on the bus; low rolling resistance. Studied are normal reactions to the vehicle wheels when braking, namely found that if the friction coefficient on the road for less than the calculated optimal braking, the restriction on the braking occurs danger of losing control of the car skidding due to the front wheels. If the coefficient of friction on the road more than the calculated optimal braking, the braking force limitation occurs for blocking the rear axle. When comparing full stopping distance with the existing area of visibility is determined permissible speed.

  2. Synchrotron UV-visible multispectral luminescence microimaging of historical samples.

    Science.gov (United States)

    Thoury, Mathieu; Echard, Jean-Philippe; Réfrégiers, Matthieu; Berrie, Barbara; Nevin, Austin; Jamme, Frédéric; Bertrand, Loïc

    2011-03-01

    UV-visible luminescence techniques are fre-quently used for the study of cultural heritage materials, despite their limitations for identification and discrimination in the case of complex heterogeneous materials. In contrast to tabletop setups, two methods based on the vacuum ultraviolet (VUV)-UV-visible emission generated at a bending magnet of a synchrotron source are described. The main advantages of the source are the extended wavelength range attained, the continuous tunability of the source, and its brightness, leading to a submicrometer lateral resolution. Raster-scanning microspectroscopy and full-field microimaging were implemented and tested at the DISCO beamline (synchrotron SOLEIL, France). Investigative measurements were performed on a sample from a varnished musical instrument and a paint sample containing the pigment zinc white (ZnO) in order to illustrate some of the challenges analyzing heterogeneous cultural heritage cross-section samples with the novel imaging approach. The data sets obtained proved useful for mapping organic materials at the submicrometer scale and visualizing heterogeneities of the semiconductor pigment material. We propose and discuss the combined use of raster-scanning microspectroscopy and full-field microimaging in an integrated analytical methodology. Synchrotron UV luminescence appears as a novel tool for identification of craftsmen's and artists' materials and techniques and to assess the condition of artifacts, from the precise identification and localization of luminescent materials.

  3. A Novel Keyless Entry System Using Visible Light Communication

    Directory of Open Access Journals (Sweden)

    Kuniyoshi Okuda

    2014-10-01

    Full Text Available A major conventional car key is the mechanical key. When users inserted the key into a cylinder mechanical key and turn, users can unlock. The mechanical key may be able to be worn away for physical contact. And it may be impossible to use. Further the mechanical key may be damaged or destroyed by mischief. So a keyless entry system has been developed. The keyless entry system locks and unlocks using the infrared ray and radio waves communication. The keyless entry system does not require physical contacts. Therefore, the possibilities of damage due to mischief and be worn away are fell. However, the transmission ranges of infrared ray and radio waves communication are not clear. Submitting data might be tapped to the malicious people. If the information is tapped, then you have theft of the car and the risk of car break. We propose a keyless entry system using visible light communication in order to solve this problem. Visible light communication transmits signal using blinking light. Thus the transmission range is clear. The user can transmit the information only to the aimed place. Therefore, the usability is improved. We measure the durations of "take out the remote control", "put the aim" and "takes to unlock key" in order to evaluate the usability in the experiment. We also compared with the infrared ray communication and examined the superiority. Usability is improved in the experimental results, and usability is better than conventional keyless entry system.

  4. Controlling the visible luminescence in hydrothermal ZnO

    Energy Technology Data Exchange (ETDEWEB)

    Lem, Laurent L.C.; Phillips, Matthew R.; Ton-That, Cuong, E-mail: Cuong.Ton-That@uts.edu.au

    2014-10-15

    Cathodoluminescence spectra have been measured in hydrothermal and hydrogen-doped ZnO at different excitation densities and temperatures to investigate the emission efficiencies of near-band-edge (NBE), green and yellow luminescence bands. The NBE intensity depends linearly on the electron beam excitation as expected for excitonic recombination character. The intensities of the green and yellow bands are highly dependent not only on the excitation density but also on temperature. At high excitation densities ZnO exhibits dominant green emission at room temperature; the intensity of the green band can be further controlled by doping ZnO with hydrogen, which passivates green luminescence centers. Conversely at small excitation densities (< 0.1 nA) and low temperatures the visible luminescence from ZnO is predominantly yellow due to the abundance of Li in hydrothermal ZnO. The results are explained by differences in the recombination kinetics and the relative concentrations of the green and yellow centers, and illustrate that single-color emission can be achieved in ZnO by adjusting the excitation power and temperature. - Highlights: • Hydrothermal ZnO crystals are analyzed by cathodoluminescence spectroscopy. • Intensities of luminescence bands are highly dependent on excitation density. • Visible luminescence is influenced by temperature and hydrogen dopants. • Emission efficiencies are explained by recombination kinetics of defects.

  5. THE VISIBILITY AND PERFORMANCE OF THE ROMANIAN SCIENTIFIC RESEARCH

    Directory of Open Access Journals (Sweden)

    STELIANA SANDU

    2013-12-01

    Full Text Available The wide dissemination of scientific research results represents the means for outlining of the prestige and visibility of Romanian scientific research on the global or regional arena and for highlighting the performance and the contribution of Romanian researchers to the scientific progress in their specific scientific interest field. Evaluation of the scientific performances is a complex process, involving quantitative and qualitative methods and approaches. The evaluation of the publications and the ranking of the authors, of the scientific papers and of the research institutions could be a useful instrument for policy makers in order to enhance the management of research activity and for its efficient funding, taking into consideration not only the social and economic priorities of the scientific topics or the relevance of research projects, but also, the performance of the scientific activity of the research teams. Despite of shortcomings and of criticisms drawn by some authors, especially when it comes to the social sciences, the bibliometric assessments are a tool for profiling of the visibility and impact of the research activity and for allowing interesting and relevant international comparisons. Drawing on bibliometric data from the Scimago Journal and Country Rank, this paper aims to evaluate the position of the Romanian scientific research in international hierarchy, and the factors that influenced the current position of research activity from Romania.

  6. Multiplex visibility graphs to investigate recurrent neural network dynamics

    Science.gov (United States)

    Bianchi, Filippo Maria; Livi, Lorenzo; Alippi, Cesare; Jenssen, Robert

    2017-03-01

    A recurrent neural network (RNN) is a universal approximator of dynamical systems, whose performance often depends on sensitive hyperparameters. Tuning them properly may be difficult and, typically, based on a trial-and-error approach. In this work, we adopt a graph-based framework to interpret and characterize internal dynamics of a class of RNNs called echo state networks (ESNs). We design principled unsupervised methods to derive hyperparameters configurations yielding maximal ESN performance, expressed in terms of prediction error and memory capacity. In particular, we propose to model time series generated by each neuron activations with a horizontal visibility graph, whose topological properties have been shown to be related to the underlying system dynamics. Successively, horizontal visibility graphs associated with all neurons become layers of a larger structure called a multiplex. We show that topological properties of such a multiplex reflect important features of ESN dynamics that can be used to guide the tuning of its hyperparamers. Results obtained on several benchmarks and a real-world dataset of telephone call data records show the effectiveness of the proposed methods.

  7. Photonic crystals at visible, x-ray, and terahertz frequencies

    Science.gov (United States)

    Prasad, Tushar

    Photonic crystals are artificial structures with a periodically varying refractive index. This property allows photonic crystals to control the propagation of photons, making them desirable components for novel photonic devices. Photonic crystals are also termed as "semiconductors of light", since they control the flow of electromagnetic radiation similar to the way electrons are excited in a semiconductor crystal. The scale of periodicity in the refractive index determines the frequency (or wavelength) of the electromagnetic waves that can be manipulated. This thesis presents a detailed analysis of photonic crystals at visible, x-ray, and terahertz frequencies. Self-assembly and spin-coating methods are used to fabricate colloidal photonic crystals at visible frequencies. Their dispersion characteristics are examined through theoretical as well as experimental studies. Based on their peculiar dispersion property called the superprism effect, a sensor that can detect small quantities of chemical substances is designed. A photonic crystal that can manipulate x-rays is fabricated by using crystals of a non-toxic plant virus as templates. Calculations show that these metallized three-dimensional crystals can find utility in x-ray optical systems. Terahertz photonic crystal slabs are fabricated by standard lithographic and etching techniques. In-plane superprism effect and out-of-plane guided resonances are studied by terahertz time-domain spectroscopy, and verified by numerical simulations.

  8. [Visible-NIR spectral feature of citrus greening disease].

    Science.gov (United States)

    Li, Xiu-hua; Li, Min-zan; Won Suk, Lee; Reza, Ehsani; Ashish, Ratn Mishra

    2014-06-01

    Citrus greening (Huanglongbing, or HLB) is a devastating disease caused by Candidatus liberibacter which uses psyllids as vectors. It has no cure till now, and poses a huge threat to citrus industry around the world. In order to diagnose, assess and further control this disease, it is of great importance to first find a quick and effective way to detect it. Spectroscopy method, which was widely considered as a fast and nondestructive way, was adopted here to conduct a preliminary exploration of disease characteristics. In order to explore the spectral differences between the healthy and HLB infected leaves and canopies, this study measured the visible-NIR spectral reflectance of their leaves and canopies under lab and field conditions, respectively. The original spectral data were firstly preprocessed with smoothing (or moving average) and cluster average procedures, and then the first derivatives were also calculated to determine the red edge position (REP). In order to solve the multi-peak phenomenon problem, two interpolation methods (three-point Lagrangian interpolation and four-point linear extrapolation) were adopted to calculate the REP for each sample. The results showed that there were, obvious differences at the visible & NIR spectral reflectance between the healthy and HLB infected classes. Comparing with the healthy reflectance, the HLB reflectance was higher at the visible bands because of the yellowish symptoms on the infected leaves, and lower at NIR bands because the disease blocked water transportation to leaves. But the feature at NIR bands was easily affected by environmental factors such as light, background, etc. The REP was also a potential indicator to distinguish those two classes. The average REP was slowly moving toward red bands while the infection level was getting higher. The gap of the average REPs between the healthy and HLB classes reached to a maximum of 20 nm. Even in the dataset with relatively lower variation, the classification

  9. UVESP: Ultraviolet Visible Echellé Spectropolarimeter for Stellar Astrophysics.

    Science.gov (United States)

    Yushkin, Maxim; Sachkov, Mikhail; Gomez De Castro, Ana; Marcos-Arenal, Pablo; Belén Perea Abarca, G.; Panchuk, Vladimir

    2016-07-01

    UVESP is an efficient instrument designed for mid resolution (30,000) spectropolarimetric observations in the 119-888nm wavelength range. Simultaneous spectropolarimetry in the optical and ultraviolet (UV) range is the only tool to study the precise characteristics of stellars magnetic fields and their connection with atmospheric structures, outflows, envelopes. The UV range is very rich in atomic and molecular lines. Moreover, hot stars radiation peaks in the UV range. The visible (VIS) spectrum provides information of the surface of the stars. Simultaneous UV and visible wavelength coverage will allow the extension of Doppler mapping methods into the winds, chromospheres and discs of stars, providing the 3D maps of their magnetospheres and immediate environments. The formation of planets around stars and the environmental conditions for emergence of life on these planets can be studied by monitoring the UV spectrum and the magnetic activity. In this contribution, we describe the optical design of UVESP. The instrument is fed by the radiation of an F/13 telescope that goes through an on-focus single polarimeter. The two spectrographs (UV and VIS) are fed by light coming from the polarimeter. The polarimeter splits the incoming beam into two states of polarization At the entrance of the instrument, a beam splitter divides the beam into the ultraviolet (UV) and the visible (VIS) channels with wavelength ranges of 355 nm to 888 nm for the VIS channel and 119 to 320 nm for the UV channel. In the VIS channel the beam continues to the slit and then a collimator is placed in order to illuminate a prism (double pass) with a collimated beam. After the prism an Echellé-grating and a a concave diffraction grating are allocated . After the grating, objective lenses are allocated. In the UV channel the beam continues from the slit to a collimator mirror. After, an Echelle-grating is allocated. The cross-dispersion is made with a toroidal diffraction grating. This design is

  10. Discrete Input Signaling for MISO Visible Light Communication Channels

    KAUST Repository

    Arfaoui, Mohamed Amine

    2017-05-12

    In this paper, we study the achievable secrecy rate of visible light communication (VLC) links for discrete input distributions. We consider single user single eavesdropper multiple-input single-output (MISO) links. In addition, both beamforming and robust beamforming are considered. In the former case, the location of the eavesdropper is assumed to be known, whereas in the latter case, the location of the eavesdropper is unknown. We compare the obtained results with those achieved by some continuous distributions including the truncated generalized normal (TGN) distribution and the uniform distribution. We numerically show that the secrecy rate achieved by the discrete input distribution with a finite support is significantly improved as compared to those achieved by the TGN and the uniform distributions.

  11. Virtual Environment Design for Low/Zero Visibility Tower Tools

    Science.gov (United States)

    Reisman, Ron; Farouk, Ahmed; Edwards, Thomas A. (Technical Monitor)

    1998-01-01

    This paper describes prototype software for three-dimensional display of aircraft movement based on realtime radar and other Air Traffic Control (ATC) information. This prototype can be used to develop operational tools for controllers in ATC Towers who cannot view aircraft in low or zero visibility (LZV) weather conditions. The controller could also use the software to arbitrarily reposition his virtual eyepoint to overcome physical obstructions or increase situation awareness. The LZV Tower tool prototype consists of server and client components. The server interfaces to operational ATC radar and communications systems, sending processed data to a client process written in java. This client process runs under Netscape Communicator to provide an interactive perspective display of aircraft in the airport environment. Prototype VRML airport models were derived from 3-D databases used in FAA-certified high fidelity flight-simulators. The web-based design offers potential efficiency increases and decreased costs in the development and deployment of operational LZV Tower tools.

  12. Characterization of river flow fluctuations via horizontal visibility graphs

    CERN Document Server

    Braga, A C; Costa, L S; Ribeiro, A A; de Jesus, M M A; Tateishi, A A; Ribeiro, H V

    2015-01-01

    We report on a large-scale characterization of river discharges by employing the network framework of the horizontal visibility graph. By mapping daily time series from 141 different stations of 53 Brazilian rivers into complex networks, we present an useful approach for investigating the dynamics of river flows. We verified that the degree distributions of these networks were well described by exponential functions, where the characteristic exponents are almost always larger than the value obtained for random time series. The faster-than-random decay of the degree distributions is an another evidence that the fluctuation dynamics underlying the river discharges has a longe-range correlated nature. We further investigated the evolution of the river discharges by tracking the values of the characteristic exponents (of the degree distribution) and the global clustering coefficients of the networks over the years. We show that the river discharges in several stations have evolved to become more or less correlate...

  13. p-Type NiO Hybrid Visible Photodetector.

    Science.gov (United States)

    Mallows, John; Planells, Miquel; Thakare, Vishal; Bhosale, Reshma; Ogale, Satishchandra; Robertson, Neil

    2015-12-23

    A novel hybrid visible-light photodetector was created using a planar p-type inorganic NiO layer in a junction with an organic electron acceptor layer. The effect of different oxygen pressures on formation of the NiO layer by pulsed laser deposition shows that higher pressure increases the charge carrier density of the film and lowers the dark current in the device. The addition of a monolayer of small molecules containing conjugated π systems and carboxyl groups at the device interface was also investigated and with correct alignment of the energy levels improves the device performance with respect to the quantum efficiency, responsivity, and photogeneration. The thickness of the organic layer was also optimized for the device, giving a responsivity of 1.54 × 10(-2) A W(-1) in 460 nm light.

  14. Inverse design of LED arrangement for visible light communication systems

    Science.gov (United States)

    Zheng, Huanhuan; Chen, Jian; Yu, Changyuan; Gurusamy, Mohan

    2017-01-01

    In this paper, an optimal LED arrangement for indoor visible light communications (VLC) is proposed and numerically investigated. By using the concept of inverse design, the LED distribution can be formulated as a convex optimization problem and resolved accordingly. We show that sufficient brightness and uniform signal to noise ratio (SNR) can be achieved within the indoor coverage by using the proposed optimal LED arrangement, thus enabling the terminal mobility for indoor VLC. In addition, the analysis of delay spread distribution over the receiving plane shows that the design exhibits enhanced tolerance of inter-symbol interference (ISI). With the consideration of cabling cost for practical implementation, the suboptimal LED arrangement design is also investigated. Numerical results indicate that the suboptimal design can reduce the power consumption of the system with acceptable performance degradation.

  15. Social network in patient safety: Social media visibility

    Directory of Open Access Journals (Sweden)

    Azucena Santillán García

    2011-11-01

    Full Text Available Internet social network (social media is a powerful communication tool, and its use is expanding significantly. This paper seeks to know the current state of visibility in online social networks of active citizen talking about patient safety. This is an observational cross-sectional study whose target population is the websites Facebook, Twitter and Tuenti in Spain. By three consecutive cuts social profiles were found using the searching terms “seguridad+paciente” and “safety+patient”. There were found 5 profiles on Facebook that met the search criteria, 6 on Twitter and none were found on Tuenti. It is concluded that although there is evidence of the rise of social networking, citizen network involved in patient safety appears not to be significantly represented within the social networks examined.

  16. PAM sequence design for dimmable visible light communication

    Science.gov (United States)

    Nuo, Huang; Wang, Jun-Bo; Wang, Jin-Yuan; Guan, Rui; Chen, Ming

    2017-02-01

    In current visible light communication (VLC) systems employing intensity modulation and direct detection (IM/DD), the transmitted optical intensity signal must satisfy the nonnegativity, peak optical intensity and illumination constraints. By taking into account the three constraints, we first present the signal space for the pulse amplitude modulated (PAM) sequences in the maximum flickering time period (MFTP). Then, to minimize the error probability of the VLC systems, we seek to find the PAM sequences providing the largest minimum Euclidean distance. Since the objective function is nonconvex and nondifferentiable, it is difficult to solve the original optimization problem directly. Thus, two methods corresponding to the joint design and greedy algorithm, are proposed to design the PAM sequences in VLC. The two methods offer a tradeoff between the symbol error rate (SER) performance and design complexity.

  17. A novel mirror diversity receiver for indoor MIMO visible light

    KAUST Repository

    Park, Ki-Hong

    2016-03-01

    In this paper, we propose and study a non-imaging receiver design reducing the correlation of channel matrix for indoor multiple-input multiple-output (MIMO) visible light communication (VLC) systems. Contrary to previous works, our proposed mirror diversity receiver (MDR) not only blocks the reception of light on one specific direction but also improves the channel gain on the other direction by receiving the light reflected by a mirror deployed between the photodetectors. We analyze the channel capacity and optimal height of mirror in terms of maximum channel capacity for a 2 -by-2 MIMO-VLC system in a 2-dimensional geometric model.We prove that this constructive and destructive effects in channel matrix resulting from our proposed MDR are more beneficial to obtain well-conditioned channel matrix which is suitable for implementing spatial-multiplexing MIMO-VLC systems in order to support high data rate.

  18. Nano-fabricated pixelated micropolarizer array for visible imaging polarimetry

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Zhigang; Cheng, Teng; Qiu, Kang; Zhang, Qingchuan, E-mail: zhangqc@ustc.edu.cn, E-mail: wgchu@nanoctr.cn; Wu, Xiaoping [CAS Key Laboratory of Mechanical Behavior and Design of Materials, Department of Modern Mechanics, University of Science and Technology of China, Hefei 230027 (China); Dong, Fengliang; Chu, Weiguo, E-mail: zhangqc@ustc.edu.cn, E-mail: wgchu@nanoctr.cn [Nanofabrication Laboratory, National Center for Nanoscience and Technology, Beijing 100190 (China)

    2014-10-15

    Pixelated micropolarizer array (PMA) is a novel concept for real-time visible imaging polarimetry. A 320 × 240 aluminum PMA fabricated by electron beam lithography is described in this paper. The period, duty ratio, and depth of the grating are 140 nm, 0.5, and 100 nm, respectively. The units are standard square structures and the metal nanowires of the grating are collimating and uniformly thick. The extinction ratio of 75 and the maximum polarization transmittance of 78.8% demonstrate that the PMA is suitable for polarization imaging. When the PMA is applied to real-time polarization imaging, the degree of linear polarization image and the angle of linear polarization image are calculated from a single frame image. The polarized target object is highlighted from the unpolarized background, and the surface contour of the target object can be reflected by the polarization angle.

  19. Visibility of stars, halos, and rainbows during solar eclipses.

    Science.gov (United States)

    Können, Gunther P; Hinz, Claudia

    2008-12-01

    The visibility of stars, planets, diffraction coronas, halos, and rainbows during the partial and total phases of a solar eclipse is studied. The limiting magnitude during various stages of the partial phase is presented. The sky radiance during totality with respect to noneclipse conditions is revisited and found to be typically 1/4000. The corresponding limiting magnitude is +3.5. At totality, the signal-to-background ratio of diffraction coronas, halos, and rainbows has dropped by a factor of 250. It is found that diffraction coronas around the totally eclipsed Sun may nevertheless occur. Analyses of lunar halo observations during twilight indicate that bright halo displays may also persist during totality. Rainbows during totality seem impossible.

  20. Quantifying Pilot Visual Attention in Low Visibility Terminal Operations

    Science.gov (United States)

    Ellis, Kyle K.; Arthur, J. J.; Latorella, Kara A.; Kramer, Lynda J.; Shelton, Kevin J.; Norman, Robert M.; Prinzel, Lawrence J.

    2012-01-01

    Quantifying pilot visual behavior allows researchers to determine not only where a pilot is looking and when, but holds implications for specific behavioral tracking when these data are coupled with flight technical performance. Remote eye tracking systems have been integrated into simulators at NASA Langley with effectively no impact on the pilot environment. This paper discusses the installation and use of a remote eye tracking system. The data collection techniques from a complex human-in-the-loop (HITL) research experiment are discussed; especially, the data reduction algorithms and logic to transform raw eye tracking data into quantified visual behavior metrics, and analysis methods to interpret visual behavior. The findings suggest superior performance for Head-Up Display (HUD) and improved attentional behavior for Head-Down Display (HDD) implementations of Synthetic Vision System (SVS) technologies for low visibility terminal area operations. Keywords: eye tracking, flight deck, NextGen, human machine interface, aviation