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Sample records for cerebellopontine angle lipoma

  1. Cerebellopontine Angle Lipoma

    PubMed Central

    Schuhmann, Martin U.; Lüdemann, Wolf O.; Schreiber, Hartwig; Samii, Madjid

    1997-01-01

    Intracranial lipomas in an infratentorial and extra-axial location are extremely rare. The presented case of an extensive lipoma of the cerebellopontine angle (CPA) represents 0.05% of all CPA tumors operated on in our department from 1978 to 1996. The lipoma constitutes an important differential diagnosis because the clinical management differs significantly from other CPA lesions. The clinical presentation and management of the presented case are analyzed in comparison to all previously described cases of CPA lipomas. The etiology and the radiological features of CPA lipomas are reviewed and discussed. CPA lipomas are maldevelopmental lesions that may cause slowly progressive symptoms. Neuroradiology enables a reliable preoperative diagnosis. Attempts of complete lipoma resection usually result in severe neurological deficits. Therefore, we recommend a conservative approach in managing these patients. Limited surgery is indicated if the patient has an associated vascular compression syndrome or suffers from disabling vertigo. ImagesFigure 1Figure 2Figure 3Figure 4 PMID:17171031

  2. A Case of Bell’s Palsy with an Incidental Finding of a Cerebellopontine Angle Lipoma

    PubMed Central

    Choy, Winward; Lee, Seung J; Chung, Lawrance K; Bui, Timothy T; Yang, Isaac; Goldman, Howard W

    2016-01-01

    This case report illustrates the potential fallacy of attributing a patient’s symptoms to an incidental finding. Serial imaging of small, asymptomatic cerebellopontine angle (CPA) lipomas is favored. It is imperative to accurately diagnose CPA lipoma on imaging and differentiate it from more common CPA lesions. We herein present a patient with symptoms consistent with Bell’s palsy and an incidental finding of a CPA lipoma. Additionally, we performed a review of the literature for case reports of patients presenting with facial symptoms and diagnosed with a CPA lipoma. PMID:27733958

  3. Angiomas of the cerebellopontine angle.

    PubMed

    Viale, G L; Pau, A; Viale, E S; Turtas, S

    1981-01-01

    Angiomas situated within the pontocerebellar cistern lie superficially on the ventrolateral aspect of the brain stem. Occasionally, minor extensions penetrate into the adjacent nervous structures. Five patients bearing such lesions were operated upon, using a microsurgical technique. Radical excision was performed in all cases. Within 2 to 12 months the patients had returned to their previous occupations, being fully able to work or attend school. There is increasing evidence for the effectiveness of surgical treatment of angiomas of the ventrolateral aspect of the brain stem and the cerebellopontine angle. The illness usually presents with hemorrhages of varying severity, ranging from mild to devastating. Impairment of consciousness, contralateral hemiparesis and ipsilateral cranial nerve palsies are the most frequent neurological signs after bleeding. The outcome following excision is primarily related to the preoperative condition. No additional deficits or only minor further impairment can be expected from surgical interference. Exploration is advisable whenever the malformation appears to lie on the surface rather than within the brain stem.

  4. Neurenteric cysts of the cerebellopontine angle.

    PubMed

    Roder, Constantin; Ebner, Florian H; Schuhmann, Martin U

    2013-12-01

    Neurenteric cysts in the central nervous system are rare developmental malformations. Usually the cysts are located ventral to the high thoracic or low cervical spinal cord. Only a few cases of intracranial neurenteric cysts have been reported in the literature to date. We report two cases of intracranial neurenteric cysts in the cerebellopontine angle with totally different radiographic, macroscopic, and microscopic appearance. As seen in these cases, the imaging spectrum of neurenteric cysts can be diverse, including malignancy-suspecting partial rim-enhancement or low-grade glioma features. Microsurgical therapy should include endoscopic assistance to ensure complete removal of cyst content. PMID:23397125

  5. Solitary Fibrous Tumor of the Cerebello-Pontine Angle

    PubMed Central

    Biggs, Nigel D.; Fagan, Paul A.; Turner, Jennifer J.; Doust, Bruce

    1999-01-01

    A case is presented of solitary fibrous tumor occurring in the cerebello-pontine angle. There have been only two other reported cases of a solitary fibrous tumors in this region. Imaging studies showed the tumor to be characteristic in shape and position of an acoustic tumor. However, at surgery the tumor was found to have a “rock hard” consistency. Solitary fibrous tumor differs from acoustic schwannoma and meningioma in its histopathological features and in this case, regrowth, after incomplete excision, was extremely rapid. ImagesFigure 2Figure 3Figure 4Figure 5Figure 6 PMID:17171119

  6. Cerebellopontine angle primitive neuroectodermal tumor mimicking trigeminal schwannoma

    PubMed Central

    Khan, Saad Akhtar; Ujjan, Badar Uddin; Salim, Adnan; Shamim, Shahzad

    2016-01-01

    Background: Primitive neuroectodermal tumors (PNETs) comprise a group of aggressive, poorly differentiated embryonal tumors occurring in central nervous system as well as in peripheral locations. Primary cerebellopontine angle (CPA) PNET is an extremely rare entity. It is important to have knowledge of this pathology and to be able to differentiate it from other commonly occurring CPA tumors, such as vestibular and trigeminal schwannomas. This distinction is essential because of the difference in the overall treatment plan and prognosis. Case Description: This report describes a case of a young male presenting with diplopia and numbness of face; magnetic resonance imaging showed a CPA mass. With a provisional diagnosis of trigeminal schwannoma, the patient underwent surgery. Histopathology provided a diagnosis of PNET. Conclusion: We discuss the importance of recognizing this rare condition and how this entity differs from the commonly occurring tumors. PMID:26862446

  7. Recurrent solitary fibrous tumour in the cerebellopontine angle.

    PubMed

    Bikmaz, Kerem; Cosar, Murat; Kurtkaya-Yapicier, Ozlem; Iplikcioglu, A Celal; Gokduman, Cem A

    2005-09-01

    Solitary fibrous tumours (SFT) of the central nervous system are rare. They resemble meningioma in clinical presentation, imaging features and appearance at surgery. Schwannoma, hemangiopericytoma and other spindle cell mesenchymal neoplasms should also be considered in the differential diagnosis. Although the histogenesis of this tumour is still debated, strong CD34 reactivity of the tumour cells suggests that SFT is mesenchymal. We present the clinical, radiological, and pathological features of an SFT located in the cerebellopontine angle (CPA). A 55-year-old female presented with 6 months of headache. The MRI scan showed a contrast enhancing ovoid mass in the left CPA. At craniotomy, the tumour was completely resected. Histolopathological diagnosis was of meningioma. Three years later, the symptoms recurred and an MRI scan demonstrated tumour recurrence. A repeat craniotomy was performed and the lesion was again completely excised. Tumour morphology on histopathology and immunoreactivity for CD34 of the tumour cells supported the diagnosis of SFT. Review of the original tumour also disclosed immunoreactivity for CD34. Ki67 labeling indices were less than 1% in both tumours.

  8. Hemangiopericytoma of the Cerebellopontine Angle: A Wolf in Sheep's Clothing

    PubMed Central

    Badri, Mohamed; Kassar, Alia Zehani; Hammouda, Karim Ben; Jemel, Hafedh

    2016-01-01

    Primary meningeal hemangiopericytoma (HPC) is a rare, aggressive dura based tumor that remarkably mimics a meningioma clinically and radiologically. Its occurrence within the cerebellopontine angle (CPA) is exceptional, and establishing the exact diagnosis is of the utmost importance since total resection remains the cornerstone of treatment. A 42-year-old man presented with a three-month history of progressively worsening vertigo and difficulty in walking. On admission, his neurological examination revealed a right peripheral facial palsy, right abducens palsy and left hemiparesis, suggesting the diagnosis of Millard-Gubler syndrome. Computed tomography and magnetic resonance imaging demonstrated a homogeneously enhancing dura based lesion of the right CPA causing major brain stem compression. There was no widening of the ipsilateral internal auditory canal. A standard retrosigmoid craniotomy was performed to access the right CPA. Exposure of the lesion revealed a well-encapsulated, gray, fibrous lesion, which appeared to originate from the tentorium. Gross total resection was achieved and confirmed radiologically. The microscopic features and the immunohistochemical profile confirmed the diagnosis of a HPC, and adjuvant radiation therapy was administered. Ten years later, the patient presented with a severe neurological deficit due to a local recurrence, but at that time refused any second intervention. He died three months later. HPC can locate within the CPA and present as a Millard-Gubler syndrome. The diagnosis should be kept in mind in case of a CPA dura based tumor. Radical surgery plus radiation therapy can maximize the recurrence-free survival and close follow-up remains mandatory to spot recurrences early. PMID:27195255

  9. Mature Teratoma of the Petrous Bone with Extension into the Cerebellopontine Angle: Case Report

    PubMed Central

    Khan, Nickalus; Klimo, Paul; Harreld, Julie; Armstrong, Gregory T.; Michael, L. Madison

    2013-01-01

    Purpose Intracranial teratomas in children involving lateral structures such as the petrous portion of the temporal bone are very uncommon. The authors report a case of a petrous teratoma with significant extension into the cerebellopontine angle with brainstem compression. Case Report An 11-year-old girl presented left-sided facial weakness. Computed tomography (CT) demonstrated a multiloculated lesion expanding the labyrinthine structures in the left petrous temporal bone including the vestibule, semicircular canals, and cochlea, with extension to the left cerebellopontine angle via the expanded left internal auditory canal. The tumor was resected via a transtemporal approach with no evidence of recurrence at nearly 2 years. Conclusion Complete resection should be the primary treatment for these tumors to minimize the risk of recurrence. To the authors' knowledge, this is the first case report of a mature teratoma originating in the petrous bone with extension into the cerebellopontine angle. PMID:24294566

  10. Unilateral vocal cord palsy and dysphagia: an unusual presentation of cerebellopontine angle meningioma

    PubMed Central

    Senior, Andrew; Douglas, James Andrew; Thompson, Stuart

    2015-01-01

    Cerebellopontine angle (CPA) tumours are the most common neoplasms in the posterior fossa, accounting for 5–10% of intracranial tumours. Most CPA tumours are benign, with most being vestibular schwannomas. Meningiomas arising from the jugular foramen are among the rarest of all with very few being described in the literature. Treatment options vary considerably as experience with these tumours is limited. One option is a skull base approach, but this depends on size, location and ability to preserve lower cranial nerve function. This can be extremely challenging and is accompanied by high mortality risk; therefore, a more conservative option must be considered. This case report highlights the difficulty in management of patients with jugular fossa meningiomas, including appropriate investigations, analysis of surgical versus conservative treatment and associated complications. Furthermore, we elaborate the decision-making process pertaining to the tailoring of the surgical route used for the resection of jugular foramen meningiomas. (Jugular Foramen Meningioma, cerebellopontine angle). PMID:26486157

  11. Solitary fibrous tumor of the cerebellopontine angle with salivary gland heterotopia: a unique presentation.

    PubMed

    Rodriguez, Fausto; Scheithauer, Bernd W; Ockner, Daniel M; Giannini, Caterina

    2004-01-01

    We report the unique association of a solitary fibrous tumor of the cerebellopontine angle with ectopic salivary gland tissue in a 53-year-old woman. The patient, diagnosed 21 years earlier with a right cerebellopontine angle fibrous meningioma, presented with a recurrent mass, which, upon surgical removal, showed features of a solitary fibrous tumor. Strong and diffuse immunoreactivity to CD34 and BCL-2 and a negative epithelial membrane antigen immunostain confirmed the diagnosis. Admixed with the spindle cell neoplasm, a bland glandular element composed of small glands and variably dilated tubules was noted. The vague tubuloacinar arrangement of the glands and the presence of acinar cells with a granular, periodic acid-Schiff-positive, basophilic cytoplasm, resembling serous type acini, were features of benign, although ectopic, salivary gland tissue. The presence of a myoepithelial cell layer, surrounding some of the acini and highlighted by the smooth muscle actin immunostain, strengthened this interpretation.

  12. Cerebral salt wasting syndrome: postoperative complication in tumours of the cerebellopontine angle.

    PubMed

    Ruiz-Juretschke, Fernando; Arístegui, Miguel; García-Leal, Roberto; Fernández-Carballal, Carlos; Lowy, Alejandro; Martin-Oviedo, Carlos; Panadero, Teresa

    2012-02-01

    Cerebral salt wasting (CSW) is a rare complication in posterior fossa tumour surgery. We present two patients with cerebellopontine angle (CPA) tumours who developed cerebral salt wasting postoperatively. Both patients deteriorated in spite of intensive fluid and salt replacement. On CT scan the patients presented mild to moderate ventricular dilation, which was treated with an external ventricular drainage. After the resolution of hydrocephalus, fluid balance rapidly returned to normal in both patients and the clinical status improved. Identification and treatment of secondary obstructive hydrocephalus may contribute to the management of CSW associated to posterior fossa tumour surgery.

  13. Chronic Lyme disease with an expansive granulomatous lesion in the cerebellopontine angle.

    PubMed

    Mokry, M; Flaschka, G; Kleinert, G; Kleinert, R; Fazekas, F; Kopp, W

    1990-09-01

    Expansive granulomatous lesions in the posterior cranial fossa are rare and have not been reported in conjunction with Lyme disease. We report a patient with verified Borrelia burgdorferi infection who developed a tumor in the cerebellopontine angle. Rapid growth of the tumor led to signs of cerebral compression and to hydrocephalus. Surgical intervention was required despite florid meningitis. The histological examination showed inflammatory, nonspecific granulation tissue. The origin of this tissue is almost certainly causally related to the B. burgdorferi infection. Signs of inflammation resolved rapidly after subtotal resection. The clinical, radiological, and biochemical course is documented. This is the first report of an expansive cerebral lesion in the chronic phase of Lyme disease.

  14. Cerebellopontine angle and internal auditory canal: neurovascular anatomy on gas CT cisternograms

    SciTech Connect

    Bird, C.R.; Hasso, A.N.; Drayer, B.P.; Hinshaw, D.B. Jr.; Thompson, J.R.

    1985-03-01

    The authors reviewed 103 normal gas CT cisternograms to delineate the appearance of normal neurovascular structures in the cerebellopontine angle (CPA) and internal auditory canal (IAC). Cranial nerves VII and VIII were identified in the CPA in 97% of cases, either separately (53%) or as a bundle (44%). Intracanalicular branches of the VIIIth cranial nerve were identified in 20% of cases, and cranial nerve V was visualized in the CPA in 14%. The characteristic vascular loop, usually the anterior inferior cerebellar artery, was visible in 35% of cases, and, in 22% of visualized cases, was in an intracanalicular location. In 10% of cases, greater than 66% of the IAC was occupied by the neurovascular bundle. Familiarity with the normal anatomy and variations seen on gas CT cisternograms is necessary to prevent false-positive interpretations.

  15. Unique Presentation of Cerebellopontine Angle Choroid Plexus Papillomas: Case Report and Review of the Literature

    PubMed Central

    Anderson, Mark; Babington, Parker; Taheri, Reza; Diolombi, Mairo; Sherman, Jonathan H.

    2013-01-01

    Objectives We present the case of a choroid plexus papilloma (CPP) in the cerebellopontine angle (CPA), describe the different appearances of CPPs with a variety of imaging techniques, and discuss the differential diagnosis of CPA tumors. Participant and Design We report the case of a 52-year-old woman with headache, tinnitus, and unilateral hearing impairment whose preoperative magnetic resonance imaging revealed a heterogeneously enhancing CPA mass that extended into the internal auditory canal. Main Outcome Measures, Results, and Conclusion The preoperative imaging appearance of the lesion was most consistent with that of a schwannoma. Postoperative histopathologic examination found the tumor to be a CPP with cuboidal epithelial cells overlying fibrovascular stroma. CPPs are rare benign central nervous system neoplasms arising from choroid plexus epithelium. The most common site of presentation is in the fourth ventricle in adults and the lateral ventricles in children. CPPs rarely occur in the CPA, and when they do, clinical-radiologic diagnosis is difficult due to both the rarity of this presentation and to nonspecific radiological features. PMID:25083384

  16. Cranial nerve root entry zone primary cerebellopontine angle gliomas: a rare and poorly recognized subset of extraparenchymal tumors.

    PubMed

    Arnautovic, K I; Husain, M M; Linskey, M E

    2000-09-01

    With the exception of patients with neurofibromatosis type II, pediatric extraparenchymal cerebellopontine angle (CPA) tumors of any sort are extremely rare. Most gliomas encountered in the CPA in either children or adults involve the CPA as exophytic extensions of primary brain stem and/or cerebellar tumors. We encountered an unusual case of a giant CPA pilocytic astrocytoma arising from the proximal trigeminal nerve, completely separate from the brain stem. A nine-year-old girl with no evidence for any neurocutaneous syndrome, presented with headaches, mild obstructive hydrocephalus, trigeminal hypesthesia and a subtle peripheral facial paresis. Pre-operative neuroimaging suggested a petroclival meningioma. The tumor was completely resected via a right pre-sigmoid, retro-labyrinthine, subtemporal, transtentorial ('petrosal') approach, using intraoperative neurophysiological monitoring, with minimal morbidity. This appears to be the first reported case of a pediatric primary CPA glioma and the seventh reported case of primary CPA glioma, overall. It represents the second reported case of a primary CPA pilocytic astrocytoma. Given the findings in this case and the six other cases of primary CPA gliomas reported in the literature, as well as the results of histological studies of normal cranial nerves, we hypothesize that the point of origin of these rare and unusual tumors is the root entry zone of the involved cranial nerves. The differential diagnosis of primary CPA tumors should be expanded to include cranial nerve root entry zone primary CPA gliomas.

  17. Metastatic Extrapulmonary Small Cell Carcinoma to the Cerebellopontine Angle: A Case Report and Review of the Literature

    PubMed Central

    Theodros, Debebe; Goodwin, C. Rory; Crane, Genevieve M.; Liauw, Jason; Kleinberg, Lawrence

    2015-01-01

    Extrapulmonary small cell carcinomas (EPSCC) are rare malignancies with poor patient prognoses. We present the case of a 63-year-old male who underwent surgical resection of a poorly differentiated small cell carcinoma, likely from a small intestinal primary tumor that metastasized to the cerebellopontine angle (CPA). A 63-year-old male presented with mild left facial paralysis, hearing loss, and balance instability. MRI revealed a 15 mm mass in the left CPA involving the internal auditory canal consistent with a vestibular schwannoma. Preoperative MRI eight weeks later demonstrated marked enlargement to 35 mm. The patient underwent a suboccipital craniectomy and the mass was grossly different visually and in consistency from a standard vestibular schwannoma. The final pathology revealed a poorly differentiated small cell carcinoma. Postoperative PET scan identified avid uptake in the small intestine suggestive of either a small intestinal primary tumor or additional metastatic disease. The patient underwent whole brain radiation therapy and chemotherapy and at last follow-up demonstrated improvement in his symptoms. Surgical resection and radiotherapy are potential treatment options to improve survival in patients diagnosed with NET brain metastases. We present the first documented case of skull base metastasis of a poorly differentiated small cell carcinoma involving the CPA. PMID:25810937

  18. Usefulness of PRESTO magnetic resonance imaging for the differentiation of schwannoma and meningioma in the cerebellopontine angle.

    PubMed

    Tomogane, Yusuke; Mori, Kanji; Izumoto, Shuichi; Kaba, Keizo; Ishikura, Reiichi; Ando, Kumiko; Wakata, Yuki; Fujita, Shigekazu; Shirakawa, Manabu; Arita, Norio

    2013-01-01

    The principles of echo-shifting with a train of observations (PRESTO) magnetic resonance (MR) imaging technique employs an MR sequence that sensitively detects susceptibility changes in the brain. The effectiveness of PRESTO MR imaging was examined for distinguishing between cerebellopontine angle (CPA) schwannomas and meningiomas in 24 patients with CPA tumors, 12 with vestibular schwannomas, and 12 with meningiomas. Histopathological study of surgical specimens showed that 11 of the 12 schwannomas contained hemosiderin deposits and all had microhemorrhages. One meningioma contained hemosiderin deposits and two involved microhemorrhages. Abnormal vessel proliferation, and dilated and thrombosed vessels were observed in all schwannomas and in 4 meningiomas. In addition to MR imaging with all basic sequences, PRESTO MR imaging and computed tomography were performed. PRESTO imaging showed significantly more schwannomas (n = 12) than meningiomas (n = 2) exhibited intratumoral spotty signal voids which were isointense to air in the mastoid air cells (p < 0.001). These spotty signal voids were significantly associated with histopathologically demonstrated hemosiderin deposits (p < 0.001), microhemorrhages (p < 0.01), and abnormal vessels (p < 0.04). The visualization of spotty signal voids on PRESTO images is useful to distinguish schwannomas from meningiomas.

  19. Clinicopathologic study of endolymphatic sac tumor (ELST) and differential diagnosis of papillary tumors located at the cerebellopontine angle.

    PubMed

    Du, Jiang; Wang, Junmei; Cui, Yun; Zhang, Cuiping; Li, Guilin; Fang, Jingyi; Yue, Shenglin; Xu, Li

    2015-10-01

    We investigated the clinicopathologic features and immunophenotypes of 10 cases of endolymphatic sac tumor (ELST) and compared them with other papillary tumors, including eight cases of choroid plexus papilloma (CPP), three cases of atypical choroid plexus papilloma (ACPP), two cases of papillary ependymoma (PE), three cases of papillary meningioma (PM) and two cases of metastatic carcinoma (MC) the at cerebellopontine angle (CPA). The age at onset of ELST ranged from 13 to 39 years. The male-to-female ratio was 1:1. The clinical presentations were primarily ear-related symptoms. The temporal bones showed extensive destruction. Histologically, the important characteristics for differential diagnosis with CPP, which is most similar to ELST, include the quantity of blood vessels, the nuclei location at apical surface of the papillary, clear cytoplasm cells sometimes with visible vacuoles, psammoma bodies and dura or bone invasion. Immunohistochemistry stains for AE1/AE3, cytokeratin CK)5/6, epithelial membrane antigen, CK8/18, S-100, and synaptophysin are helpful in diagnosis of ELST. In ELST, ultrastructure of uniform 2 μm vesicles in cytoplasm was seen, and gene analysis also showed missense mutation in exon 3. This study indicates that the above histological features combined with immunohistochemistry findings are important for making the correct diagnosis. Gene analysis should be used in patients without medical history to exclude von Hippel-Lindau disease. PMID:25944396

  20. Myoepithelioma of the cerebellopontine angle: a previously not documented benign salivary gland-type neoplasm within the cranium.

    PubMed

    Vajtai, Istvan; Hewer, Ekkehard; Neuenschwander, Maja; Schäfer, Stephan C; Kappeler, Andreas; Lukes, Anton

    2013-01-01

    Myoepithelioma is a dimorphic neoplasm with contractile-epithelial phenotype, originally interpreted as deriving from, but not actually restricted to the salivary glands. As a novel addition to the list of exquisitely rare intracranial salivary gland-type tumors and tumor-like lesions, we report on an example of myoepithelioma encountered in the left cerebellopontine angle of a 32-year-old male. Clinically presenting with ataxia and dizziness, this extraaxial mass of 4 × 3.5 × 3 cm was surgically resected, and the patient is alive 6 years postoperatively. Histologically, the tumor exhibited a continuum ranging from compact fascicles of spindle cells to epithelial nests and trabeculae partitioned by hyalinized septa, while lacking tubular differentiation. Regardless of architectural variations, there was robust immunoexpression of S100 protein, smooth muscle actin, GFAP, cytokeratin, and vimentin. Cytologic atypia tended to be modest throughout, and the MIB1 labeling index averaged less than 1%. Fluorescent in situ hybridization indicated no rearrangement of the EWSR1 locus. We interpret these results to suggest that myoepithelioma of the posterior fossa - along with related salivary epithelial tumors in this ostensibly incongruous locale - may possibly represent analogous neoplasms to their orthotopic counterparts, ones arising within aberrant salivary anlagen. The presence of the latter lends itself to being mechanistically accounted for by either postulating placodal remnants in the wake of branchial arch development, or linking them to exocrine glandular nests within endodermal cysts. Alternatively, myoepithelioma at this site could be regarded as a non tissue-specific lesion similar to its relatives ubiquitously occurring in the soft parts.

  1. Intraoral Lipoma: A Case Report

    PubMed Central

    Kumar, L. K. Surej; Kurien, Nikhil Mathew; Raghavan, Varun B.; Menon, P. Varun; Khalam, Sherin A.

    2014-01-01

    Lipomas are rare in oral and maxillofacial regions although they are the most common tumours of mesenchymal origin in human body. The etiology remains unclear. Various different theories explain the pathogenesis of this adipose tissue tumour and also different histological variants of oral lipoma have been given in literature. A case of intraoral lipoma occurring in mental region in a 77-year-old male is reported along with review of the literature. Wide surgical excision was performed and two-year followup showed excellent healing without any recurrence. Lipomas are benign soft tissue neoplasm of mature adipose tissue seen as a common entity in the head and neck region. Intraoral lipomas are a rare entity which may be noticed only during routine dental examinations. Most of them rarely cause pain, resulting in delay to seek treatment. It is mandatory for a clinician to diagnose intraoral lipomas using latest diagnostic methods and conservatively treat them without causing much discomfort. PMID:24592278

  2. Esophageal Lipoma: A Rare Tumor

    PubMed Central

    Feldman, Jeremy; Tejerina, Manfred; Hallowell, Michael

    2012-01-01

    Esophageal lipomas are rare tumors, making up 0.4% of all digestive tract benign neoplasms. Most of these lesions are clinically silent as a result of their small size, however, the majority of lesions over 4 cm have been reported to cause dysphagia, regurgitation and/or epigastralgia. We report a case of a 53 year-old African American female who presented with dysphagia. Computed tomography of the chest and esophagram confirmed esophageal lipoma as the cause of the patient’s symptoms. Accurately diagnosing an esophageal lipoma is crucial in order to rule out potential malignant lesions, relieve patient symptoms and plan the appropriate treatment. PMID:23365708

  3. Vulvar lipoma: a case report

    PubMed Central

    2014-01-01

    Introduction Vulvar lipoma is a rare tumor localization and only a few cases have been reported. The clinical characteristics of vulvar lipoma are well known. However, it is important to distinguish lipomas from liposarcomas. We report a case of vulvar lipoma and discuss its clinical features, including diagnostic aspects, with emphasis on histopathological evaluation of all excised lesions. We also report and discuss patient management and treatment outcomes. Case presentation We report the case of a 27-year-old Moroccan woman. Our patient presented with a painless and slow-growing right vulvar mass that had evolved over one year, which had suddenly become uncomfortable when walking. A physical examination revealed a single soft and pasty mass in her left labium majus, which could be mobilized under her skin towards her mons pubis. The largest dimension of the mass measured 6cm. Magnetic resonance imaging showed a homogenous hyperintense mass with a well-defined contour in her left labium majus; a fat-suppressed magnetic resonance image demonstrated a marked signal intensity decrease. The mass was completely removed surgically. A histological examination revealed a circumscribed benign tumor composed of mature adipocytes, confirming the diagnosis of vulvar lipoma. Conclusion Vulvar lipomas must be differentiated from liposarcomas, which demonstrate very similar clinical and imaging profiles. The final diagnosis should be based on histopathological evaluation. A precise diagnosis should allow for appropriate surgical treatment. PMID:24946809

  4. Giant Retroperitoneal Lipoma in an Infant

    PubMed Central

    2014-01-01

    Lipomas can occur almost anywhere in the body, but retroperitoneal lipomas are extremely rare. They are slowly growing benign tumors and can attain an enormous size due to silent course of the disease. Total excision of the mass is the treatment of choice and is curative for benign retroperitoneal lipomas. We treated an 11-month-old female patient with giant retroperitoneal lipomas by surgical excision. Histopathology confirmed it as fibrolipoma. PMID:25374800

  5. Giant Lipoma of Posterior Cervical Region

    PubMed Central

    Kumar, Lovekesh; Karande, Snehal K.; Kolhe, Yuvraj

    2014-01-01

    Lipomas are the slow growing soft tissue tumors of benign nature. They commonly grow on torso and extremities but may also develop in head and neck region. Rarely lipomas can grow to acquire gigantic proportions, turning into an entity termed as giant lipoma. Such lipomas are entitled to immediate attention as they have a relatively high malignant potential. We report a rare case of giant cervical lipoma in an elderly gentleman, followed by a brief discussion on diagnosis and management of the disorder. PMID:25349767

  6. Translocation (Y;12) in lipoma.

    PubMed

    Liang, Cher-Wei; Mariño-Enríquez, Adrian; Johannessen, Catherine; Hornick, Jason L; Dal Cin, Paola

    2011-01-01

    Lipomas are the most common benign mesenchymal neoplasm in adults, and have been extensively characterized at the cytogenetic level. Chromosomal aberrations have been observed in the majority of lipomas, two-thirds of which involve chromosomal region 12q14.3. To date, structural rearrangements have been reported affecting every chromosome except chromosome Y. Here we report a case of a lipoma that shows a novel apparently balanced translocation involving chromosomes Y and 12. Fluorescence in situ hybridization using a break-apart HMGA2 in-house probe set detected a single signal on the normal chromosome 12 but not on either the derivative chromosome Y or 12, indicating a cryptic loss of 12q14.3, where HMGA2 is mapped. Immunohistochemical studies, however, revealed overexpression of HMGA2 with nuclear expression in the majority of tumor cells, whereas MDM2 and CDK4 were negative. The overexpression of HMGA2 may be caused by a cryptic chromosomal aberration affecting either the cytogenetically unaltered HMGA2 allele or HMGA2 regulators elsewhere. The current case broadens our knowledge about the translocation partners of HMGA2 in lipomas and highlights the biological complexity in regulating HMGA2 expression. PMID:21356192

  7. Intramuscular Lipoma: A Review of the Literature

    PubMed Central

    McTighe, Shane; Chernev, Ivan

    2014-01-01

    Lipomas are the most common type of soft tissue mesenchymal tumors. They are typically located subcutaneously and consist of mature fatty tissue. When they occur under the enclosing fascia, they are called deep-seated lipomas. Infrequently, lipomas can arise inside the muscle and are called intramuscular lipomas. Intramuscular lipomas have been commonly investigated and categorized in the same group as other deep-seated and superficial lipomatous lesions. Their clinical, histological and imaging characteristics may resemble well-differentiated liposarcomas, further adding to the difficulties in the differential diagnosis. This article summarizes the available literature and describes the typical epidemiological, pathological and clinical features of intramuscular lipomas, as well as delineating their treatment and prognosis. PMID:25568733

  8. Lipoma of the Thumb: Spindle Cell Subtype

    PubMed Central

    El Rayes, Johnny; Bou Sader, Roula; Saliba, Elie

    2016-01-01

    We report hereby the case of a 61-year-old man who presented with a soft-tissue swelling on the palmar aspect of the thumb. A detailed clinical examination followed by ultrasonography and excisional biopsy confirmed a spindle cell lipoma. Lipomas are rare in the hand and exceptional in the fingers, and we report, to our knowledge, the first spindle cell lipoma in the thumb to help in the differential diagnosis of a similar swelling. PMID:27088022

  9. Oral cavity lipoma: a case report

    PubMed Central

    Park, Byeong-Gi; Choi, Dong-Ju; Park, Jun-Woo

    2015-01-01

    Intraoral lipomas are a rare clinical entity, comprising only 0.1% to 5% of all benign tumors in the intraoral cavity. A 56-year-old woman suffering from diabetes presented with this relatively rare intraoral lipoma and was treated by surgical excision under general anesthesia. Because the mass was located adjacent to the mental foramen, a precise dissection was necessary to ensure minimal nerve damage. No abnormalities or recurrence was noted at 1-year follow-up and the patient did not complain of numbness. We studied the occurrence of oral lipoma in this diabetic patient and reviewed the relationship between oral lipoma and diabetes in the literature. PMID:26339582

  10. Childhood giant omental and mesenteric lipoma.

    PubMed

    Hamidi, Hidayatullah; Rasouly, Najibullah; Khpalwak, Hayatullah; Malikzai, Mohammad Omer; Faizi, Ahmad Reshad; Hoshang, Mer Mahmood Shah; Maroof, Sahar; Nasery, Mohammad Nawaz; Farzam, Farhad; Salehzai, Mohibullah; Sadiqi, Jamshid

    2016-03-01

    Omental and mesenteric lipomas are very rare benign lesions of mature adipose tissue. They are well-defined, noninvasive, and encapsulated masses that can be discovered in asymptomatic patients or may cause variable nonspecific symptoms depending on their size and location. The omental and mesenteric lipoma has confusing features in ultrasound; however, computed tomography and magnetic resonance imaging can well characterize and demarcate these lesions. Though few cases of mesenteric and omental lipomas have been reported in the literature, but because of its large size and childhood presentation, the case we present, can be one of the largest childhood omental and mesenteric lipomas ever reported. A 6-year-old girl presented with slowly progressing abdominal distension and repeated dull abdominal pain for last 4 years. Abdominal and pelvic computed tomography examination revealed a huge mesenteric and omental lipoma that was resected surgically without any complications. PMID:26973731

  11. An unusual case of lipoma arborescens.

    PubMed

    Mohammad, H R; Chaturvedi, A; Peach, C

    2016-09-01

    Introduction Lipoma arborescens is a rare condition of the synovial lining. It is particularly uncommon in the bicipitoradial bursae of the elbow. Case Report A 68-year-old woman presented with a 5-month history of anterior elbow pain and swelling causing discomfort. Radiography demonstrated reactive changes of radial tuberosity and magnetic resonance imaging confirmed lipoma arborescens of the bicipitoradial bursa with distal biceps tendinopathy. A bicipital bursa bursectomy and lipoma excision was performed. Gross pathology and histology was consistent with lipoma arborescens. Three months postoperatively, our patient had full range of motion and good strength. Conclusions To our knowledge, this is the first published case report of lipoma arborescens affecting the elbow. Recognising the differential diagnoses of anterior elbow pain and the characteristic imaging is essential for accurate diagnosis. PMID:27241604

  12. Huge Tongue Lipoma: A Case Report

    PubMed Central

    Damghani, Mohammad Ali; Safari, Mohammad

    2015-01-01

    Introduction: Lipomas are among the most common tumors of the human body. However, they are uncommon in the oral cavity and are observed as slow growing, painless, and asymptomatic yellowish submucosal masses. Surgical excision is the treatment of choice and recurrence is not expected.  Case Report: The case of a 30-year-old woman with a huge lipoma on the tip of her tongue since 3 years, is presented. She had difficulty with speech and mastication because the tongue tumor was filling the oral cavity. Clinical examination revealed a yellowish lesion, measuring 8 cm in maximum diameter, protruding from the lingual surface. The tumor was surgically excised with restoration of normal tongue function and histopathological examination of the tumor confirmed that it was a lipoma. Conclusion: Tongue lipoma is rarely seen and can be a cause of macroglossia. Surgical excision for lipoma is indicated for symptomatic relief and exclusion of associated malignancy. PMID:25938089

  13. Lipoma or hemangioma: A diagnostic dilemma?

    PubMed Central

    Reddy, K. Vinay Kumar; Roohi, Shameena; Maloth, Kotya Naik; Sunitha, K.; Thummala, Venkata Satya Ramesh

    2015-01-01

    Lipomas and hemangiomas are well-known benign lesions of the body. However, their occurrence in the oral cavity is rare. Lipoma accounts for 1-4% of benign neoplasms of mouth affecting predominantly the buccal mucosa, floor of mouth and tongue. Hemangiomas occur mostly on the lips, buccal mucosa, tongue, and palate. Lipomas when superficially placed show yellowish surface discoloration and hemangiomas usually have reddish blue to deep blue color. Here, we report an unusual case of benign tumor occurring in the buccal vestibule. PMID:26097370

  14. Solitary lipoma in the retromandibular region

    PubMed Central

    Shetty, Nandesh; Shabari, U B; Jaydeep, N A; Patnaik, Pritish

    2015-01-01

    Lipomas are the most common subcutaneous soft-tissue tumors. These are benign tumors originating from the adipocytes. They may be located in any part of the body and can be confused clinically with other soft tissue masses. They infrequently occur in the head and neck region. We present a case of solitary lipoma arising in the neck region that was reported to our division of oral and maxillofacial surgery. PMID:25767361

  15. Congenital infiltrative lipomas in a calf.

    PubMed

    Sickinger, Marlene; Wasieri, Jasmin; Koehler, Kernt; Doll, Klaus; Reinacher, Manfred

    2009-09-01

    The current report describes a case of congenital subcutaneous and intramuscular tumors of the neck and tail base in a 4-week-old female Angus-Charolais crossbred calf. Results of clinical and ultrasound examination are summarized. Biopsy and necropsy findings indicated an infiltrative lipoma. Congenital lipomas are uncommon tumors in bovids. Clinical and morphologic differentials, as well as classification and the possible pathogenesis of congenital neoplasms, are discussed. PMID:19737773

  16. Post-traumatic Lipoma of the Parotid gland

    PubMed Central

    Rehal, Satnam Singh; Alibhai, Mustansir; Perera, Esther

    2016-01-01

    Lipoma of the parotid gland is a rare entity. Trauma with soft tissue haematoma formation and subsequent lymphatic effusion, fat necrosis and lipoma formation have been postulated as an aetiological pathway. We report a case of a post-traumatic lipoma of the parotid gland to add to the available literature on this uncommon pathology. PMID:27106616

  17. Pedunculated colonic lipoma prolapsing through the anus

    PubMed Central

    Ghanem, Omar M; Slater, Julia; Singh, Puneet; Heitmiller, Richard F; DiRocco, Joseph D

    2015-01-01

    Colorectal lipomas are the second most common benign tumors of the colon. These masses are typically incidental findings with over 94% being asymptomatic. Symptoms-classically abdominal pain, bleeding per rectum and alterations in bowel habits-may arise when lipomas become larger than 2 cm in size. Colonic lipomas are most often noted incidentally by colonoscopy. They may also be identified by abdominal imaging such as computed tomography or magnetic resonance imaging. We report a case of a sixty-one years old male who presented to our emergency room with a 6.7 cm × 6.3 cm soft tissue mucosal mass protruding transanally. The patient was stable with a benign abdominal examination. The mass was initially thought to be a rectal prolapse; however, a limited digital rectal exam was able to identify this as distinct from the anal canal. Since the mass was irreducible, it was elected to be resected under anesthesia. At surgery, manipulation of the mass identified that the lesion was pedunculated with a long and thickened stalk. A laparoscopic linear cutting stapler was used to resect the mass at its stalk. Pathology showed a polypoid submucosal lipoma of the colon with overlying ulceration and necrosis. We report this case to highlight this rare but possible presentation of colonic lipomas; an incarcerated, trans-anal mass with features suggesting rectal prolapse. Trans-anal resection is simple and effective treatment. PMID:25984520

  18. Pleural lipoma: a non-surgical lesion?

    PubMed Central

    Jayle, Christophe; Hajj-Chahine, Jamil; Allain, Geraldine; Milin, Serge; Soubiron, Laurent; Corbi, Pierre

    2012-01-01

    Pleural lipomas are benign tumours that develop at the expense of adipose tissues, and they never evolve towards liposarcoma. Located usually at the mediastinal, bronchial and pulmonary levels, a pleural situation is extremely rare. Chest X-rays usually detect them and computed tomography scans confirm the diagnosis. As complications occur, a wait-and-see policy is common. We report our pleural lipoma surgical exeresis experience since 1999. We have operated on five cases of pleural lipomas among nearly 1800 cases of thoracic exeresis: three male and two female patients, without obesity (in all cases, body mass index (BMI) < 28). The mean age was 54.6 years (range 35–72 years). Four patients were electively operated and one in emergency, three with video-assisted thoracic surgery (VATS) procedure and two with open chest surgery, without recurrent cases. Advancements in VATS have greatly reduced the morbidity rate of these benign tumours especially if exeresis is performed early on a small, uncomplicated adhesion-free tumour. On the other hand, the operation may be deleterious, complicated by the presence of a large lipoma or in a complicating situation. In our opinion, we should revise the wait-and-see policy when facing these lesions considering their evolutionary potential. We should advise VATS in pleural lipomas. PMID:22371386

  19. Peripheral nerve lipoma: Case report of an intraneural lipoma of the median nerve and literature review

    PubMed Central

    Teles, Alisson Roberto; Finger, Guilherme; Schuster, Marcelo N.; Gobbato, Pedro Luis

    2016-01-01

    Adipose lesions rarely affect the peripheral nerves. This can occur in two different ways: Direct compression by an extraneural lipoma, or by a lipoma originated from the adipose cells located inside the nerve. Since its first description, many terms have been used in the literature to mention intraneural lipomatous lesions. In this article, the authors report a case of a 62-year-old female who presented with an intraneural median nerve lipoma and review the literature concerning the classification of adipose lesions of the nerve, radiological diagnosis and treatment. PMID:27695575

  20. Peripheral nerve lipoma: Case report of an intraneural lipoma of the median nerve and literature review

    PubMed Central

    Teles, Alisson Roberto; Finger, Guilherme; Schuster, Marcelo N.; Gobbato, Pedro Luis

    2016-01-01

    Adipose lesions rarely affect the peripheral nerves. This can occur in two different ways: Direct compression by an extraneural lipoma, or by a lipoma originated from the adipose cells located inside the nerve. Since its first description, many terms have been used in the literature to mention intraneural lipomatous lesions. In this article, the authors report a case of a 62-year-old female who presented with an intraneural median nerve lipoma and review the literature concerning the classification of adipose lesions of the nerve, radiological diagnosis and treatment.

  1. [An unusual case of massive funicular lipoma].

    PubMed

    Masciovecchio, Stefano; Saldutto, Pietro; Del Rosso, Alessandro; Galatioto, Giuseppe Paradiso; Vicentini, Carlo

    2014-01-01

    Intrascrotal lipomas are benign diseases that originate from adipose tissue inside the scrotal sac or constituting the scrotal wall itself. Paratesticular spermatic cord lipomas are a rare type of intrascrotal lipomas. A 78 years old patient in good health comes to our attention for massive tense-elastic swelling of left hemiscrotum appeared about 3 years ago and slowly increasing. Ultrasound evaluation of the intrascrotal mass showed inhomogeneous images mainly hyperechoic, not infiltrating the ipsilateral testis and scrotal wall. The ultrasonography found a lipomatous lesion with benign characteristics and a surgical excision has been performed. The lipomatous mass removed presented a size equal to 25 cm x 14 cm x 11 cm and a weight of about 490 gr. The microscopic examination of the tissue showed only the presence of mature adipocytes in the absence of cellular atypia, of other cellular types and of vascular abnormalities.

  2. Treatment of lipoma by injection lipolysis.

    PubMed

    Nanda, Soni

    2011-05-01

    Injection lipolysis or lipodissolve is the practice of injecting phosphatidyl choline/ sodium deoxycholate (PDC/DC) compounds in the subcutaneous fat. Though this practice is being used extensively for nonsurgical contouring of body and dissolving localized collections of excess fat, it's use as a treatment modality for lipomas needs further evaluation. We present a case where this technique was used for treating a lipoma, with no recurrence after 9 months of follow up. Injection lipolysis as a treatment modality for lipomas needs to be evaluated for safety and efficacy in trials on larger population. This could prove to be a very valuable adjunct to the current practice of excision, if done by a trained person in a properly selected patient. Also the side effects and the controversies regarding this procedure have been discussed in detail in the present paper.

  3. Lipoma in oral mucosa: two case reports.

    PubMed

    Hoseini, Ali Tavakoli; Razavi, Seyed Mohammad; Khabazian, Arezu

    2010-01-01

    Lipoma is a common tumor of soft tissue. Its location on the oral mucosa is rare, representing 1% to 5% of benign oral tumors although it is the most mesenchymal tumor of the trunk and proximal por-tions of extremities. Lipoma of the oral cavity may occur in any region. The buccal mucosa, tongue, and floor of the mouth are among the common locations. The clinical presentation is typically as an asymptomatic yellowish mass. The overlying epithelium is intact, and superficial blood vessels are usually evident over the tumor. Other benign connective tissue lesions such as granular cell tumor, neurofibroma, traumatic fibroma and salivary gland lesions (mucocele and mixed tumor) might be included in differential diagnosis. We present two cases of oral lipoma in unusual locations: one in junction of soft and hard palate and the other in tongue. Both were rare in the literature.

  4. Intraosseous lipoma of the iliac: case report☆

    PubMed Central

    de Moraes, Frederico Barra; Paranahyba, Rodrigo Marques; do Amaral, Rogério Andrade; Bonfim, Vinícius Mendes; Jordão, Nathalya Ducarmo; Souza, Raimundo Djalma

    2016-01-01

    Lipomas are benign tumors that attack fat cells and most often affecting soft tissues in adulthood. On rare occasions, they may affect bones, preferentially the metaphyses of the long bone. They are generally asymptomatic and radiography shows radiolucent lesions with a thin sclerotic rim or radiodense lesions with a thick sclerotic rim. Malignant transformation of these tumors is rare, as is their recurrence, and there is no need for surgery in most cases. In this report, we present a rare case of intraosseous lipoma in the iliac bone. PMID:26962507

  5. Spindle Cell Lipoma of the Soft Palate

    PubMed Central

    Hançer, Ahmet; Özbay, Can; Karaarslan, Serap; Balaban, Muzaffer

    2015-01-01

    Intraoral spindle cell lipomas (SCL) are very rare and comprise ranging between 1.4%–9.8% of all intraoral lipomas. To our knowledge, no case of a SCL located on the soft palate has been reported in the English-language literature. A 31-year-old female was admitted with a swelling in her soft palate. On examination, a 3 cm sessile, nontender swelling was observed on her soft palate. After surgical excision, it was diagnosed as a SCL. PMID:25878917

  6. Symptomatic subserosal gastric lipoma successfully treated with enucleation.

    PubMed

    Krasniqi, Avdyl-Selmon; Hoxha, Faton-Tatil; Bicaj, Besnik-Xhafer; Hashani, Shemsedin-Isuf; Hasimja, Shpresa-Mehmet; Kelmendi, Sadik-Mal; Gashi-Luci, Lumturije-Hasan

    2008-10-14

    Gastric lipomas are rare tumors, accounting for 2%-3% of all benign gastric tumors. They are of submucosal or extremely rare subserosal origin. Although most gastric lipomas are usually detected incidentally, they can cause abdominal pain, dyspeptic disorders, obstruction, invagination, and hemorrhages. Subserosal gastric lipomas are rarely symptomatic. There is no report on treatment of subserosal gastric lipomas in the English literature. We present a case of a 50-year-old male with symptomatic subserosal gastric lipoma which was successfully managed with removal, enucleation of lipoma, explorative gastrotomy and edge resection for histology check of gastric wall. The incidence of gastric lipoma, advanced diagnostic possibilities and their role in treatment modalities are discussed.

  7. A rare presentation of lipoma on mandibular mucogingival junction

    PubMed Central

    Sharma, Gaurav; Jain, Kanu; Nagpal, Archna; Baiju, Chandrababu Sudha

    2016-01-01

    Lipoma is the most common tumor of mesenchymal tissues of body, but its occurrence in oral cavity is infrequent. Buccal mucosa is the most common intraoral site of lipoma followed by tongue, floor of the mouth, and buccal vestibule. The involvement of mucogingival junction is rare. We present a unique case report of oral lipoma occurring on mandibular mucogingival junction with review of literature which has emphasis on differential diagnosis. PMID:27143835

  8. Intrasynovial lipoma causing trigger wrist and carpal tunnel syndrome.

    PubMed

    Imai, Shinji; Kodama, Narihito; Matsusue, Yoshitaka

    2008-01-01

    Triggering of the flexor tendon at the wrist is rare. We report a case of intrasynovial lipoma that caused a trigger wrist. As far as we know it is unique in that the intrasynovial lipoma simultaneously caused carpal tunnel syndrome. The massive tenosynovitis and adhesion of flexors tendons after the locking of the intrasynovial lipoma may have resulted from inflammation caused by attrition within the carpal tunnel.

  9. Gastric lipoma: an unusual cause of dyspeptic symptoms.

    PubMed

    Nasa, Mukesh; Choksey, Ajay; Phadke, Aniruddha; Sawant, Prabha

    2016-01-01

    Gastric lipomas are rare tumours accounting for 2-3% of all benign gastric tumours. These are usually submucosal in origin but in rare cases may be subserosal in origin. Although a majority of gastric lipomas are asymptomatic and usually detected incidentally, occasionally these can cause abdominal pain, dyspeptic disorders, obstruction, invagination and haemorrhages. In the literature, only 200 cases of gastric lipomas have been reported so far. We report a case of a 56-year-old female with a submucosal symptomatic gastric lipoma presenting with disabling dyspeptic symptoms. PMID:27335362

  10. Rare Occurrence of Lip Spindle Cell Lipoma

    PubMed Central

    Girgis, Sandra; Cheng, Leo

    2015-01-01

    Spindle cell lipoma (SCL) is a rare distinct variant of lipoma, which presents as a painless, circumscribed, slow-growing, superficial lesion on the lip and can mimic a minor salivary gland tumour. We present a slow growing lower lip lesion and its management. Case Report. A 38-year-old female gave an eight-year history of a slow-growing mass on her lower lip with intermittent change in size. She presented with a submucosal nodule and thin overlying mucosa adjacent to the vermilion border. Surgical excision was carried as the diagnostic and therapeutic approach. Conclusion. Lip SCL is rare, and surgical excision is advocated in order to exclude underlying pathology and minor salivary gland tumours. PMID:25815220

  11. Massive intrathoracic lipoma in men1 syndrome

    PubMed Central

    Sturiale, Alessandro; Giudici, Francesco; Alemanno, Giovanni; Cavalli, Tiziana; Addasi, Rami; Santomaggio, Carmine; Meoni, Giulia; Brandi, Maria Luisa; Tonelli, Francesco

    2014-01-01

    Introduction The multiple endocrine neoplasia type 1 (MEN1) is a rare autosomal dominant syndrome characterized by the onset of hyperparathyroidism, gastroenteropancreatic neuroendocrine tumors and pituitary lesions. Presentation of case This appears to be the first described case of a massive intrathoracic lipoma in MEN1. The patient was affected with primary hyperparathyroidism treated with a total parathyroidectomy followed by a distal pancreatectomy for insulinoma. At follow-up, the computed tomography showed a massive lesion on the left emithorax suggestive of a lipoma. At the onset of a mild dyspnea we decided to perform the surgical excision of the mass obtaining a complete relief of the symptoms. Discussion This case is evidence of the importance of a strict follow-up of such patients. Conclusion Lipomas are the most frequent benign soft tissue tumors. They are usually sporadic but are sometimes related to hereditary syndromes. Intrathoracic localizations are rare and can arise mainly in the mediastinum, bronchus or lung. The diagnosis is often incidental; despite preoperative imaging will accurately show the features of the lesions, it is impossible obtain an accurate diagnosis-hence, the treatment of choice remains the surgical excision. PMID:25545711

  12. Canine Lipomas Treated with Steroid Injections: Clinical Findings

    PubMed Central

    Lamagna, Barbara; Greco, Adelaide; Guardascione, Anna; Navas, Luigi; Ragozzino, Manuela; Paciello, Orlando; Brunetti, Arturo; Meomartino, Leonardo

    2012-01-01

    Lipomas are common benign tumours of fat cells. In most cases, surgical excision is curative and simple to perform; however, such a procedure requires general anaesthesia and may be associated with delayed wound healing, seroma formation and nerve injury in deep and intramuscular tumours. The objective of this study was to evaluate treatment of subcutaneous, subfascial or intermuscular lipomas using intralesional steroid injections in dogs. Fifteen dogs presenting with lipomas were selected for treatment with ultrasound-guided intralesional injection of triamcinolone acetonide at a dose of 40 mg/mL. Nine subcutaneous and subfascial tumours showed a complete regression. The other lipomas decreased in diameter, achieving, in some cases, remission of discomfort and regression of lameness. Steroid injection was a relatively safe and effective treatment for lipomas in dogs; only six dogs experienced polyuria/polydipsia for about 2 weeks post-treatment. PMID:23226250

  13. Giant Esophageal Lipoma as an Uncommon Cause of Diverticula

    PubMed Central

    Yekeler, Erdal; Yazicioglu, Alkin; Subasi, Mahmut; Boztepe, Hacer

    2016-01-01

    Esophageal lipoma is an uncommon benign tumor of the esophagus and accounts for only 0.4% of all benign neoplasms of the gastrointestinal system. The majority of these are located in the cervical part; only very few are located in the lower third of the esophagus. We discuss the case of a 37-year-old female who presented with dysphagia and an esophageal lipoma located in the lower third of the esophagus. The patient underwent right mini-thoracotomy and enucleation of lipoma. Histopathologic examination revealed adipose tissue with a collection of matured adipose tissue. We present the case because of the atypical localization of an esophageal lipoma and development of a diverticulum, which was caused by the lipoma and required an additional surgical procedure. PMID:27721731

  14. Giant submental lipoma: Case report and review of the literature

    PubMed Central

    Medina, Carlos R; Schneider, S; Mitra, A; Spears, J; Mitra, A

    2007-01-01

    Lipomas may be located in all parts of the body and may be confused clinically with other soft tissue masses. They infrequently occur in the head and neck. A large neck mass (greater than 10 cm) with a rapid growth rate should raise concerns about a possible malignancy. Failure to distinguish a liposarcoma from a lipoma may represent a medicolegal pitfall. Surgical excision of a lipoma is often used as the definitive treatment modality, and alternative treatments described for lipomas range from liposuction to steroid injections. In the present study, a 60-year-old man who presented with a rapidly enlarging submental mass is described. A 15 cm × 12 cm mass was successfully removed. The surgery produced excellent cosmetic results and no functional impairment. An integrated review of the literature regarding etiology, epidemiology, diagnostic and treatment modalities of submental lipomas follows. PMID:19554181

  15. [A Dumbbell-Type Thoracic Spinal Lipoma: A Case Report].

    PubMed

    Takamiya, Soichiro; Hida, Kazutoshi; Yano, Shunsuke; Sasamori, Toru; Seki, Toshitaka; Saito, Hisatoshi

    2016-06-01

    Spinal lipomas are rare, accounting for less than 1% of all spinal tumors. Most are associated with spinal dysraphism. Spinal lipomas without spinal dysraphism are uncommon;they are typically subpial tumors. Some tumors are located both inside and outside the dura mater (so-called "dumbbell-type"). Herein, we report a patient with a dumbbell-type thoracic spinal lipoma. A man in his 50's complained of progressive gait disturbance, dysesthesia in his left leg, and hyperesthesia in his right leg. His symptoms were worsened by exercise. CT and MRI revealed a thoracic spinal lipoma extending from the spinal cord to the intervertebral foramen at the Th 6-8 level. He underwent partial tumor removal and untethering. Postoperatively he reported gradual symptom abatement. Dumbbell-type spinal lipomas are very rare. Besides partial removal of the tumor, untethering should be considered when symptoms are associated with tethering of the spinal cord. PMID:27270148

  16. Atypical spindle cell lipoma: a clinicopathologic, immunohistochemical, and molecular study emphasizing its relationship to classical spindle cell lipoma.

    PubMed

    Creytens, David; van Gorp, Joost; Savola, Suvi; Ferdinande, Liesbeth; Mentzel, Thomas; Libbrecht, Louis

    2014-07-01

    We studied a series of spindle cell lipomas arising in atypical sites and showing unusual morphologic features (which we called atypical spindle cell lipoma) to assess if these lesions have the same chromosomal alterations as classical spindle cell lipoma but different from those found in atypical lipomatous tumor/well-differentiated liposarcoma. We investigated alterations of different genes in the 13q14 region and the amplification status of the MDM2 and CDK4 genes at 12q14-15 by multiplex ligation-dependent probe amplification (MLPA) and fluorescence in situ hybridization (FISH) analysis. In the atypical spindle cell lipomas, MLPA revealed deletions in the two nearest flanking genes of RB1 (ITM2B and RCBTB2) and in multiple important exons of RB1. In contrast, in classical spindle cell lipomas, a less complex loss of RB1 exons was found but no deletion of ITM2B and RCBTB2. Moreover, MLPA identified a deletion of the DLEU1 gene, a finding which has not been reported earlier. We propose an immunohistochemical panel for lipomatous tumors which comprises of MDM2, CDK4, p16, Rb, which we have found useful in discriminating between atypical or classical spindle cell lipomas and other adipocytic neoplasms, especially atypical lipomatous tumor/well-differentiated liposarcoma. Our findings strengthen the link between atypical spindle cell lipoma and classical spindle cell lipoma, and differentiate them from atypical lipomatous tumor/well-differentiated liposarcoma.

  17. Atypical spindle cell lipoma: a clinicopathologic, immunohistochemical, and molecular study emphasizing its relationship to classical spindle cell lipoma.

    PubMed

    Creytens, David; van Gorp, Joost; Savola, Suvi; Ferdinande, Liesbeth; Mentzel, Thomas; Libbrecht, Louis

    2014-07-01

    We studied a series of spindle cell lipomas arising in atypical sites and showing unusual morphologic features (which we called atypical spindle cell lipoma) to assess if these lesions have the same chromosomal alterations as classical spindle cell lipoma but different from those found in atypical lipomatous tumor/well-differentiated liposarcoma. We investigated alterations of different genes in the 13q14 region and the amplification status of the MDM2 and CDK4 genes at 12q14-15 by multiplex ligation-dependent probe amplification (MLPA) and fluorescence in situ hybridization (FISH) analysis. In the atypical spindle cell lipomas, MLPA revealed deletions in the two nearest flanking genes of RB1 (ITM2B and RCBTB2) and in multiple important exons of RB1. In contrast, in classical spindle cell lipomas, a less complex loss of RB1 exons was found but no deletion of ITM2B and RCBTB2. Moreover, MLPA identified a deletion of the DLEU1 gene, a finding which has not been reported earlier. We propose an immunohistochemical panel for lipomatous tumors which comprises of MDM2, CDK4, p16, Rb, which we have found useful in discriminating between atypical or classical spindle cell lipomas and other adipocytic neoplasms, especially atypical lipomatous tumor/well-differentiated liposarcoma. Our findings strengthen the link between atypical spindle cell lipoma and classical spindle cell lipoma, and differentiate them from atypical lipomatous tumor/well-differentiated liposarcoma. PMID:24659226

  18. Tongue lipoma in an older male: A case report and literature review of patients with tongue lipoma reported in China

    PubMed Central

    LU, SHU-LAI; ZHENG, JIAN-JIN; WU, HONG; LI, TAO; DONG, GANG; WANG, YUN-LONG; YANG, PI-SHAN

    2016-01-01

    Lipoma is the most common benign tumor that occurs at any region where adipose tissue is present. However, as the tongue is devoid of adipocyte it is an extremely rare site for a lipoma to develop, particularly in China. The present study reports the presence of a tongue lipoma in a 78-year-old man that measured 2.2×2.0×1.5 cm and was located on the left ventral region of the tongue. The tumor was completely excised, and subsequent to 4 years of follow-up, there was no recurrence of the lesion. In addition, the present study reviewed the literature concerning tongue lipomas in China and analyzed 18 other cases of patients with tongue lipomas in the past 30 years, between 1 January 1985 and 31 December 2014. PMID:26870227

  19. An intraosseous lipoma of the calcaneus: a case report.

    PubMed

    Pappas, Alexander J; Haffner, Kyle E; Mendicino, Samuel S

    2014-01-01

    Intraosseous lipomas are one of the rarest bone tumors found in the body. The incidence has been reported to be <0.1% of all primary bone tumors. The differential diagnoses of an intraosseous lipoma in the calcaneus include plantar fasciitis, retrocalcaneal bursitis, gout, stress fracture, unicameral bone cyst, aneurysmal bone cyst, osteoblastoma, enchondroma, chondromyxoid fibroma, nonossifying fibroma, giant cell tumor, chondroblastoma, fibrous dysplasia, and chondrosarcoma. It has been reported that 60% to 70% of patients with an intraosseous lipoma present with symptoms. This article describes a case of a pathologic fracture secondary to a large intraosseous lipoma, the surgical treatments, and the subsequent resolution of symptoms. The purpose of our report was 3-fold: (1) to increase awareness of intraosseous lipomas and their potential to cause pathologic fractures in the calcaneus; (2) to suggest a possible treatment protocol for intraosseous lipomas in the calcaneus; and (3) to describe a rare case of an intraosseous lipoma of the calcaneus not located exclusively in the neutral triangle. PMID:24875966

  20. Intramuscular Lipoma of the Thenar: A Rare Case

    PubMed Central

    Papakostas, Theodoros; Tsovilis, Aristomenis E.; Pakos, Emilios E.

    2016-01-01

    Lipomas are the most common benign mesenchymal tumors. They are located either subcutaneously or under the investing fascia in intramuscular or intermuscular regions. The reported frequency of intramuscular lipomas among all benign adipocytic tumors is 1.0%–5.0% and for intermuscular lipomas is 0.3%–1.9%. The frequency of these lesions is the same in all age groups, but in adults deep seated-lipomas are most commonly discovered between the ages of 30 and 60. The most common sites of involvement of intramuscular lipomas are the large muscles of the extremities, especially those of the thigh, shoulder, and upper arm. Intramuscular lipomas of the hand are extremely rare and only few cases have been reported in the literature. In cases with hand location, they may present with functional deficit or neurovascular compromise due to the effect of the mass. We report an unusual case of a large intramuscular lipoma of the thenar that was treated with surgical excision due to the impairment of hand function. PMID:26894225

  1. Como Lo Hago Yo: Lipomas Medulares

    PubMed Central

    Portillo, Santiago

    2014-01-01

    Basados en la experiencia de 82 casos; en 5% se observaron anomalías pélvicas asociadas. En los menores de 3 años el motivo de consulta (85%) fue la tumoración. En los mayores de 3 años (42%) tenía problemas neurológicos. Solo el 24% preocupados por la tumoración. El objetivo de la cirugía es desanclar la médula y no remover la totalidad del lipoma. El lipoma de filum es el que es mas simple para operar. Aún cuando la escuela francesa propone operar solamente cuando hay síntomas favorezco cirugía preventiva. Favorezco una segunda cirugía si hay signos de anclaje postoperatorio, aún cuando observamos empeoramiento postoperatorio motor en 2.5% de los operados y urológico a largo plazo en 6% de los operados. PMID:24791218

  2. Heel lipoma mimicking plantar fasciitis in a ballroom dancer.

    PubMed

    Taweel, Nicholas R; Raikin, Steven M

    2015-01-01

    The present case illustrates a lipoma as an unusual cause of heel pain. A 64-year-old female ballroom dancer presented with 8 months of pain that was unresponsive to previous treatment of plantar fasciitis. Magnetic resonance imaging revealed a heel lipoma. Her pain was fully resolved after surgical excision. Soft tissue tumors should be included in the differential diagnosis of heel pain, especially when symptoms and treatment response do not follow the typical course of plantar fasciitis.

  3. Laparoscopic resection of colonic lipomas: When and why?

    PubMed Central

    Böler, Deniz Eren; Baca, Bilgi; Uras, Cihan

    2013-01-01

    Patient: Male, >60 Final Diagnosis: Colonic lipoma Symptoms: Rectal bleeding • abdominal pain • fatique • abdominal distention Medication: — Clinical Procedure: Laparoscopic resection Specialty: General surgery Objective We aimed to review and discuss the clinical picture and management of 4 patients who underwent laparoscopic colonic resection with a definitive pathology of colonic lipoma Background: Colonic lipomas are rare benign nonepithelial tumors of the colon. They begin to be symptomatic when they reach a certain size, although the presentation can vary. Different endoscopic and surgical treatment strategies have been reported in the literature. Case Reports: Four male patients who underwent laparoscopic colonic resection and had definitive diagnosis of colonic lipoma were included in this report. All patients were over 60 years old. The first case presented with massive rectal bleeding. Obstructive symptoms and intermittent bleeding were prominent in the second and third cases. Abdominal pain and discomfort was present in the forth case. In the first 2 cases, abdominal CTs were suggestive of colonic lipoma and laparoscopic ileocecal resection was performed. However, malignancy could not be ruled out in the other 2 cases due to large size and heterogeneous appearance of the lesions and inconclusive endoscopic biopsies consisted of ulcer with exudate and inflammatory cells. Laparoscopic left and right hemicolectomy was performed in the third and forth cases, respectively. There were no complications in any patients. Conclusions: Laparoscopic resection can be the first choice in treatment of colonic lipomas with various presentations. Wider resections should be considered in cases with uncertain diagnosis. PMID:23901354

  4. Sclerotic (fibroma-like) lipoma: a distinctive lipoma variant with a predilection for the distal extremities.

    PubMed

    Laskin, William B; Fetsch, John F; Michal, Michal; Miettinen, Markku

    2006-08-01

    This report details the clinicopathologic and immunohistochemical findings identified in 21 cases of a fibrosclerotic variant of lipoma from acral sites that is frequently misdiagnosed as a fibromatous (nonlipogenic) process. The study includes 12 males and 9 females; aged 7 to 72 (mean and median, 39). The patients presented with solitary, mostly asymptomatic, masses that ranged from 0.6 to 2.2 (median, 1.2; mean, 1.3) cm and involved fingers (n=17), hands or wrists (n=3), and toes (n=1). Microscopically, the lesions were well-circumscribed nodules that showed very low to moderately low cellularity and consisted of cytologically bland spindled and stellate-shaped cells and a minor component of randomly dispersed adipocytes embedded in a collagenous to myxocollagenous stroma. Eight tumors were "fibroma-like" owing to their paucity of spindled cells, dense fibrosclerotic stroma, and inconspicuous vasculature. One tumor showed features of spindle cell/pleomorphic lipoma, whereas another demonstrated a vague onion skin-like arrangement of collagen reminiscent of sclerotic (storiform) fibroma. In all cases, the mitotic activity was negligible. Nonlipogenic tumor cells were immunoreactive for CD99 (6 of 6 cases), CD34 (6 of 8), S-100 protein (4 of 7), and smooth muscle actin (2 of 6). Follow-up data on 8 patients (range, 1 to 20 years; median, 9.5 years) revealed no recurrence in 6, but indicated the possibility of persistent tumor in the remaining 2 individuals after simple excision. Despite histological overlap in 1 case with the sclerotic fibroma, no patient displayed definitive clinical features of Cowden syndrome. Our study indicates that fibrosclerotic lipomas demonstrate a broader histological scope than what was initially described. PMID:16871033

  5. Enterococcal Cerebellopontine Angle Abscess in a 12-year-old Female.

    PubMed

    Sonavane, Alka; Baradkar, Vasant; Kumar, Simit

    2010-01-01

    Despite advances in imaging and antibiotic treatment, brain abscess is still encountered occasionally. Various aerobic and anaerobic bacteria have been reported as causative agents of brain abscess but only a few cases of enterococcal brain abscesses have been reported. Here we report a case of brain abscess in a 12-year-old female patient, who presented with a history of fever, chills, headache, convulsions since seven days and history of altered sensorium and aphasia since the last two days. The patient had chronic suppurative otitis media of both ears following trauma and presented with ear discharge. The diagnosis of brain abscess was done by computerized tomography scan and the pus was aspirated by left suboccipital burr hole operation. Enterococcus species was cultured from the aspirated pus sample. The patient responded to surgical drainage and antibiotic treatment. PMID:20300422

  6. Round ligament lipoma mimicking acute appendicitis in a 24-week pregnant female: a case report.

    PubMed

    Miller, T J; Paulk, D G

    2013-04-01

    An exhaustive search of the literature using the Pub Med database revealed no reports of round ligament lipomas mimicking acute appendicitis in pregnant patients. There are relatively few articles on round ligament lipomas and even less on round ligament lipomas during pregnancy. This case report is on a 27-year-old 24-week pregnant female who presented with signs and symptoms similar to acute appendicitis who in fact had a large right pelvic round ligament lipoma that was causing her pain.

  7. Endoscopic Resection of Lipoma of the Patellar Tendon

    PubMed Central

    Lui, Tun Hing; Lee, Man Wai

    2015-01-01

    Synovial lipoma of the patellar tendon is a very rare entity. It can be associated with rupture of the patellar tendon. We present a case of synovial lipoma that was successfully resected endoscopically. The other indications for patellar tendoscopy include chronic patellar tendinitis and tendinosis, recalcitrant bursitis around the tendon, Osgood-Schlatter disease, and jumper's knee. The major potential danger of this endoscopic procedure is iatrogenic damage to the patellar insertion during endoscopic debridement in patients with jumper's knee or the tibial insertion during endoscopic debridement in patients with Osgood-Schlatter disease. PMID:25973368

  8. Knee Locking in Osteoarthritis due to Synovial Lipoma: A Case Report.

    PubMed

    S Amarjit, Kataria; Budhiraja, Shivali; Chandramouleeswari, K; Anita, S

    2013-08-01

    Intra-articular synovial lipomas are very rare and only few cases have been reported till now. We are reporting a rare case of a unilateral intra-articular lipoma of osteoarthritic knee joint in a 62 years old male. Patient had two episodes of sudden locking of knee joint, which resolved spontaneously. A plain X-ray showed changes which were suggestive of osteoarthritis. Clinically, patient was diagnosed as a case of loose bodies in left knee joint. An arthrotomy was performed. After a Histopathological Examination (HPE) of loose bodies, a diagnosis of an intra-articular synovial lipoma was made. Due to wide differentials and varied clinical behaviour of loose bodies, lipoma should be included in differential diagnosis of osteroarthritic patients who complain of episodic locking of knees. Intraarticular lipomas, on arthroscopic guided excision, get cured permanently, with no recurrence. The differentiation of an intra-articular lipoma from a relatively more common entity, Lipoma arborescens, has also been discussed.

  9. [Hourglass Transmural Lipoma;Report of a Case].

    PubMed

    Shimoyama, Takehiko; Kimura, Bunpei

    2016-09-01

    This case report describes a 73-year-old male with an hourglass-type transmural lipoma who was referred because of an abnormal chest shadow. Computed tomography showed a well-defined fatty mass within the intra-and extra-thorax at the right 3rd intercostal portion. Magnetic resonance imaging showed a high-intensity mass that had the same signal level as fat tissue. Therefore, the tumor was diagnosed as an hourglass transmural lipoma. Tumor resection was performed with video-assisted thoracic surgery, and 3rd intercostal muscle tissue approximately 1cm from the tumor border was also resected. The tumor was 6.5×4.5×3.0 cm in size, and histologically diagnosed as an intramuscular lipoma-infiltrating type, without malignancy. Since infiltrating types of intramuscular lipoma often cause recurrence without malignant appearance, tumor specimens require careful examination. Thoracoscopic surgery was useful to determine the excision line from the intra-thorax, for complete resection of the hourglass tumor. PMID:27586324

  10. Subacromial Impingement Syndrome Caused by a Voluminous Subdeltoid Lipoma

    PubMed Central

    2014-01-01

    Subacromial impingement syndrome is a clinical diagnosis encompassing a spectrum of possible etiologies, including subacromial bursitis, rotator cuff tendinopathy, and partial- to full-thickness rotator cuff tears. This report presents an unusual case of subdeltoid lipoma causing extrinsic compression and subacromial impingement syndrome. The patient, a 60-year-old man, presented to our institution with a few years' history of nontraumatic, posteriorly localized throbbing pain in his right shoulder. Despite a well-followed 6-months physiotherapy program, the patient was still suffering from his right shoulder. The MRI scan revealed a well-circumscribed 6 cm × 2 cm × 5 cm homogenous lesion compatible with a subdeltoid intermuscular lipoma. The mass was excised en bloc, and subsequent histopathologic examination confirmed a benign lipoma. At 6-months follow-up, the patient was asymptomatic with a complete return to his activities. Based on this case and a review of the literature, a subacromial lipoma has to be included in the differential diagnosis of a subacromial impingement syndrome refractory to nonoperative treatment. Complementary imaging modalities are required only after a failed conservative management to assess the exact etiology and successfully direct the surgical treatment. PMID:24778890

  11. Lipoma of corpus callosum associated with dysraphic lesions and trisomy 13

    SciTech Connect

    Wainwright, H.; Bowen, R.; Radcliffe, M.

    1995-05-22

    We report on a further case of corpus callosal lipoma and frontal cranial defects. Most cases in the literature of corpus callosal lipoma in association with {open_quotes}dysraphic{close_quotes} lesions have been frontal in location. Malformation of the corpus callosum is said to be associated with 50% of these lipomas. Trisomy 13 was confirmed by the 13q14 cosmid probe on paraffin-embedded liver tissue. 19 refs., 5 figs.

  12. In vivo MRI characteristics of lipoma arborescens utilizing fat suppression and contrast administration

    SciTech Connect

    Chaljub, G.; Johnson, P.R.

    1996-01-01

    Lipoma arborescens or villous lipomatous proliferation of the synovium is a rare lesion. We describe the in vivo imaging characteristics of lipoma arborescens of the knee utilizing fat suppression techniques and contrast medium administration. As expected, the lesion demonstrated signal loss when utilizing fat suppression. In addition, no contrast enhancement was noted. When a synovial process demonstrates isointensity with subcutaneous fat on all pulse sequences and no contrast enhancement, lipoma arborescens should be the primary diagnosis consideration. 7 refs., 4 figs.

  13. Large ileocecal submucosal lipoma presenting as hematochezia, a case report and review of literature

    PubMed Central

    Chehade, Hiba Hassan El Hage; Zbibo, Riad Hassan; Nasreddine, Walid; Abtar, Houssam Khodor

    2015-01-01

    Introduction Colonic lipomas are rare subepithelial benign tumors affecting mainly middle-aged women. They are usually asymptomatic and, hence, are discovered incidentally on autopsy, surgery, or colonoscopy. There is a wide range of presentations like abdominal pain, bleeding per rectum, intussusception, etc. The latter picture constitutes the usual presentation of an ileocecal lipoma. Only few cases of ileocecal lipomas presenting as lower GI bleeding have been reported in the literature. Presentation of case We present a case of an adult female patient who was admitted to our institution complaining of hematochezia and right lower quadrant pain. She was found to have chronic anemia. She was investigated by CT scan of the abdomen & pelvis and by colonoscopy which showed a fungating, submucosal mass with ulcerated base near the ileocecal valve. She underwent a colonic resection. The pathology came out as a submucosal benign pedunculated ileocecal lipoma. Discussion Colonic lipomas represent 4% of benign lesions of the gastrointestinal tract. They are usually asymptomatic hence are often discovered incidentally on colonoscopy, surgery or autopsy. The definitive diagnosis is made by pathological evaluation. Colonic lipomas are usually treated if they are symptomatic or there is any suspicion of malignancy. The treatment modalities include endoscopic and surgical resection. Conclusion We, hereby, describe a case of benign ileocecal lipoma that presented with hematochezia which is an unusual presentation. Also, there is a great controversy regarding the treatment of colonic lipomas. In this article, we tried to answer several questions concerning the management of ileocecal lipomas. PMID:25770697

  14. A common tumor in an uncommon location: Lipoma of the palate

    PubMed Central

    Bakshi, Satvinder Singh; Priya, Madhu; Coumare, V. Nirmal; Vijayasundaram, S.; Karanam, Lavanya

    2015-01-01

    Lipomas are benign mesenchymal neoplasms that originate in mature adipose cells. Although rare in the oral cavity, they are mostly seen in the buccal mucosa, tongue, and gingiva; those arising from the palate are very rare. We report a case of a 42-year-old male patient with a large intraoral swelling that on excision was reported as a lipoma. Oral lipomas are rare and those occurring on the hard palate are even rarer. Radiological evaluation is warranted for larger lesions to know exact extent. Lipoma should be considered in the differential diagnosis of a palatal swelling. PMID:26981479

  15. Lipoma in the subscapularis muscle causing scapular malposition

    PubMed Central

    Kawano, Yusuke; Nakamichi, Noriaki

    2015-01-01

    A 70-year-old woman had pain and fatigability of her left shoulder with asymmetric scapular position. The medial border of the scapula was more prominent in the left side compared to the right scapula, and scapular motion was different between sides. Magnetic resonance imaging showed a mass on the ventral surface of the scapula. Tumour resection was performed through the medial approach, and the tissue samples were found to be a lipoma with a pathological examination. Post-operatively, her pain immediately disappeared. Two years after surgery, no recurrence of the tumour had been found. Soft tissue tumours have never been reported as a cause of scapular malposition or winging. We reported a case with scapular malposition and dyskinesis caused by lipoma in the subscapularis muscle. Surgical resection successfully relieved her symptoms and improved the scapular motion. Soft tissue tumour occurring in the subscapularis muscle could possibly cause abnormal scapular position and motion. PMID:27582987

  16. Lipoma in the subscapularis muscle causing scapular malposition.

    PubMed

    Kawano, Yusuke; Nakamichi, Noriaki; Matsumura, Noboru

    2015-10-01

    A 70-year-old woman had pain and fatigability of her left shoulder with asymmetric scapular position. The medial border of the scapula was more prominent in the left side compared to the right scapula, and scapular motion was different between sides. Magnetic resonance imaging showed a mass on the ventral surface of the scapula. Tumour resection was performed through the medial approach, and the tissue samples were found to be a lipoma with a pathological examination. Post-operatively, her pain immediately disappeared. Two years after surgery, no recurrence of the tumour had been found. Soft tissue tumours have never been reported as a cause of scapular malposition or winging. We reported a case with scapular malposition and dyskinesis caused by lipoma in the subscapularis muscle. Surgical resection successfully relieved her symptoms and improved the scapular motion. Soft tissue tumour occurring in the subscapularis muscle could possibly cause abnormal scapular position and motion. PMID:27582987

  17. Fusion of the HMGA2 and NFIB genes in lipoma.

    PubMed

    Nilsson, M; Panagopoulos, I; Mertens, F; Mandahl, N

    2005-11-01

    The major cytogenetic subgroup of lipomas is characterized by aberrations of chromosome segment 12q13-15, which recombines with a large number of other chromosomal regions. The gene HMGA2 is the main target in these aberrations. For some recurrent rearrangements, chimeric transcripts, including the 5' part of HMGA2, have been described. The 3' partners identified are LPP, LHFP, CMKOR1, and EBF. In addition, subsets of other benign solid tumors show aberrations of 12q13-15. Among pleomorphic adenomas of the salivary glands, where the preferred recombination partner with 12q13-15 is 9p22-24, an HMGA2/NFIB fusion gene has been reported. In the present study, two cases of lipoma with rearrangements of 9p22-24 and 12q15 were analyzed by reverse transcription polymerase chain reaction to find out if HMGA2/NFIB was also present in lipoma. An in-frame fusion transcript, combining the four first exons of HMGA2 with exon 8 of NFIB, was detected in one case. It was identical to a transcript that was previously described in salivary gland adenoma and contained a stop codon shortly 3' of the fusion point. The finding of the same fusion gene in different tumors is not unique. For example, HMGA2/LPP has been reported in lipoma, pulmonary chondroid hamartoma, and soft tissue chondroma. Since similar 9;12 translocations have been described also in rare cases of hamartoma and uterine leiomyoma, the occurrence of HMGA2/NFIB could be postulated in these tumors as well.

  18. A case of lipoma arising in the eustachian tube.

    PubMed

    Dabiri, Jonathan; Choufani, Georges; Delpierre, Isabelle; Hassid, Sergio

    2016-01-01

    We report a case of a lipoma inside the eustachian tube, an extremely rare location for this lesion. To the best of our knowledge, this is only the second such case that has been described in the literature. The patient was a 47-year-old man, a fighter pilot, who was referred to our hospital with a 3-year history of (1) fullness in the right ear secondary to recurrent serous otitis media and (2) right ear pain, which was especially acute during flights. Nasopharyngeal endoscopy, computed tomography, and magnetic resonance imaging detected the presence of a well-encapsulated lesion inside the eustachian tube; macroscopic and radiologic findings identified the mass as a lipoma. The lesion was completely removed via transnasal endoscopy. Histopathologic evaluation confirmed the diagnosis of lipoma. The patient's postoperative course was favorable, and he was able to fly again without any ear complaints. Radiologic examination is useful for the diagnosis and preoperative evaluation of this benign tumor. Lesions located in the lower part of the eustachian tube can be easily removed via a transnasal endoscopic approach. PMID:26829697

  19. The lipoma of tongue - A rare site for a tumor: Case report and review of the literature

    PubMed Central

    Baonerkar, Hemant A.; Vora, Meena; Sorathia, Rakesh; Shinde, Swapnil

    2015-01-01

    Lipoma is the most common tumor of the human body, but their presences in the oral cavity are very rare. Reported cases of lipoma of tongue in English literature are very few. Here, we report a case of lipoma of tongue in 63-year-old male patient, with its clinical presentation, the histological picture, classification, and brief review of the literature. PMID:26752882

  20. Endoscopic submucosal dissection of a large colonic lipoma: Report of two cases

    PubMed Central

    Lee, Jae Min; Kim, Jeong Ho; Kim, Myungsung; Kim, Jun Hyoung; Lee, Young Bae; Lee, Jae Hyuk; Lim, Che Wan

    2015-01-01

    A colonic lipoma is a very rare benign tumor that is usually asymptomatic and is found incidentally by colonoscopy. Patients with a large colonic lipoma may present with symptoms such as abdominal pain, bleeding, and colonic obstruction or intussusceptions. We report two patients with large colonic lipomas and symptoms. Standard endoscopic submucosal dissection (ESD) was performed to remove the lipomas instead of conventional surgical bowel resection. No complications were observed during or after the procedure. The tumors were resected en bloc, and the patients were discharged 2 d after ESD with a regular diet. The results indicate that ESD can be applied as safe and effective treatment for a large colonic lipoma. PMID:25780315

  1. Endoscopic resection of giant colonic lipoma: case series with partial resection.

    PubMed

    Kim, Gun Woo; Kwon, Chang-Il; Song, Sang Hee; Jin, Sun Mi; Kim, Kyung Ho; Moon, Jie Hye; Hong, Sung Pyo; Park, Pil Won

    2013-09-01

    Colonic lipoma, a very rare form of benign tumor, is typically detected incidentally in asymptomatic patients. The size of lipoma is reported variously from 2 mm to 30 cm, with higher likelihood of symptoms as the size is bigger. Cases with symptom or bigger lesion are surgically resected in principle; endoscopic resection, which has developed recently with groundbreaking advance of endoscopic excision technology, is being used more often but with rare report of success due to high chance of complications such as bowel perforation or bleeding. The authors report here, together with a literature review, our experiences of three cases of giant colonic lipomas showing complete remission after aggressive unroofing technique, at certain intervals, using snare catheter at the origin of the lipoma so that the remaining lipoma could be drained out of the exposed surface spontaneously, in order to reduce complications.

  2. A rare cause of childhood ileus: giant mesenteric lipoma and a review of the literature.

    PubMed

    Turk, Erdal; Edirne, Yesim; Karaca, Fahri; Memetoglu, Mehmet Erdal; Unal, Emel; Ermumcu, Ozgur

    2013-10-01

    Mesenteric lipomas are benign tumors of mature fat cells. They are usually asymptomatic and create a clinical picture that depends on the localization and size of the lipoma. Although rare, unusually large mesenteric giant lipomas can cause partial or complete bowel obstruction. Lipomas resulting in partial bowel obstruction can present with symptoms such as intermittent abdominal pain and abdominal distention. With complete obstruction, a child can present with an acute abdomen. Treatment is the excision of the mass along with the affected portion of bowel. In this case study, a 2-year-old female presented with a bowel obstruction due to the presence of a giant mesenteric lipoma. Clinical features of 16 cases published in the English literature to date are presented.

  3. Caecum lipoma: a rare cause of lower gastrointestinal bleeding

    PubMed Central

    Martinez-Mier, Gustavo; Ortiz-Bayliss, Arturo B; Alvarado-Arenas, Ruben; Carrasco-Arroniz, Miguel A

    2014-01-01

    Gastrointestinal bleeding caused by benign tumours of the colon is rare. A 70-year-old woman with a significant medical history of diabetes, hypertension and ischaemic heart disease was presented in consultation with marked anaemia secondary to lower gastrointestinal bleeding with a right colonic tumour found by CT. The patient underwent a right colectomy without complications. Histopathological examination revealed a 4 cm transmural caecum lipoma with mucosal ulceration. The patient is asymptomatic without anaemia at 6 months follow-up. PMID:25249223

  4. [Gastric lipoma as an unusual cause of upper gastrointestinal bleeding].

    PubMed

    Vogt, W; Allemann, J; Simeon, B; Fornaro, M; Rehli, V

    1995-04-18

    This is a case report of a gastric lipoma causing a severe upper gastrointestinal bleeding. About 200 cases of this very rare benign gastric tumor have been reported so far. Symptoms are not characteristic, but may also mimic malignancy when occurring with bleeding, obstruction or weight loss. Malignant transformation is possible, but extremely rare. Because the tumor is situated under the submucosal layer in 90%, preoperative diagnosis by endoscopic biopsy is almost never possible. The tumor has to be treated by resection. A diagnosis by frozen section during the operation is recommended.

  5. Knee Locking in Osteoarthritis due to Synovial Lipoma: A Case Report

    PubMed Central

    S. Amarjit, Kataria; Budhiraja, Shivali; Chandramouleeswari, K.; Anita, S.

    2013-01-01

    Intra–articular synovial lipomas are very rare and only few cases have been reported till now. We are reporting a rare case of a unilateral intra–articular lipoma of osteoarthritic knee joint in a 62 years old male. Patient had two episodes of sudden locking of knee joint, which resolved spontaneously. A plain X-ray showed changes which were suggestive of osteoarthritis. Clinically, patient was diagnosed as a case of loose bodies in left knee joint. An arthrotomy was performed. After a Histopathological Examination (HPE) of loose bodies, a diagnosis of an intra–articular synovial lipoma was made. Due to wide differentials and varied clinical behaviour of loose bodies, lipoma should be included in differential diagnosis of osteroarthritic patients who complain of episodic locking of knees. Intraarticular lipomas, on arthroscopic guided excision, get cured permanently, with no recurrence. The differentiation of an intra-articular lipoma from a relatively more common entity, Lipoma arborescens, has also been discussed. PMID:24086885

  6. Total Resection of Complex Spinal Cord Lipomas: How, Why, and When to Operate?

    PubMed Central

    PANG, Dachling

    2015-01-01

    This article shows the long-term advantage of total resection of complex spinal cord lipomas over partial resection and over non-surgical treatment for children with asymptomatic lipomas. The classification, embryogenesis, and technique of total resection of complex lipomas are described. The 20-year outcome of 315 patients who had total resection is measured by overall progression-free survival (PFS, Kaplan-Meier), and by subgroup Cox multivariate hazard analysis for the influence of four variables: lipoma type, symptoms, prior surgery, and post-operative cord-sac ratio. These results are compared to 116 patients who underwent partial resection, and to two published series of asymptomatic lipomas followed without surgery. The PFS after total resection for all lipomas is 88.1% over 20 years vs. 34.6% for partial resection at 10.5 years (p < 0.0001). The PFS for total resection of asymptomatic virgin lipomas rose to 98.8% vs. 60% and 67% for non-surgical treatment. Partial resection also compares poorly to non-surgical treatment for asymptomatic lipomas. Multivariate analyses show that a low cord-sac ratio is the only independent variable that predicts good outcome. Pre-operative profiling shows the ideal patient for total resection is a young child with a virgin asymptomatic lipoma, who, with a PFS of 99.2%, is essentially cured. The technique of total resection can be learned by any neurosurgeon. Its long-term protection against symptomatic recurrence is better than partial resection and conservative management. The surgery should be done at diagnosis, except for asymptomatic small infants in whom surgery should be postponed till 6 months to minimize morbidity. PMID:26345666

  7. Intraosseous lipoma of the calcaneus mimicking plantar fascitis.

    PubMed

    Karthik, K; Aarthi, S

    2011-06-01

    Benign lytic lesions of the calcaneus are rare and are usually asymptomatic. We report this case of a 55-year-old man with bilateral non-traumatic plantar heel pain, which was treated conservatively as plantar fasciitis. At three months follow-up, the patient had complete relief of symptoms in the left heel with partial relief of symptoms on the right side. However under the insistence of the patient an X-ray was taken, which revealed an expansile lytic lesion of the right calcaneus and a normal left heel. CT-scan revealed an expansile lytic lesion on the right calcaneus and an early lytic lesion in the left calcaneus. Following surgical intervention, the diagnosis was confirmed as intra-osseous lipoma and the patient was completely symptom free at two-year follow-up. Patients presenting with non-traumatic heel pain should be explained about the possible causes of heel pain, and should be offered X-ray at the first visit. In patients with X-ray showing unilateral lipoma of the calcaneus, CT scan should be offered to rule out involvement of the opposite side.

  8. Trans-aortic excision of intraventricular lipoma with the assistance of arthroscopic camera

    PubMed Central

    Argiriou, Mihalis; Lama, Niki; Sakellaridis, Timothy; Charitos, Christos

    2013-01-01

    Cardiac lipomas are extremely rare benign neoplasms of the heart. We report the case of a 64-year-old female complaining of rapidly worsening dyspnea and lower limb edema. Echocardiograms showed a large hyperechoic mass which occupied the left ventricle. The cardiac nuclear magnetic resonance allowed the diagnosis of the left ventricular tumor of lipoma or liposarcoma. The tumor was resected through the ascending aorta, without injuring neither the aortic valve nor the left ventricle. Histological diagnosis showed that the tumor was a lipoma. The patient had an uneventful recovery, with no recurrence two years later. PMID:23991324

  9. Infiltrative laryngeal lipoma in a Yorkshire Terrier as cause of severe dyspnoea.

    PubMed

    Brunnberg, M; Cinquoncie, S; Burger, M; Plog, S; Nakladal, B

    2013-01-01

    A 10-year-old Yorkshire Terrier with suspected laryngeal paralysis was referred for further examination and surgical treatment. The dog displayed severe dyspnoea and dysphonia. Ventrolateral to the larynx a soft-elastic mass of 2 cm diameter was palpated and confirmed by radiography. Histopathological examination of the resected mass revealed an infiltrative lipoma/lipoma. Although the dog totally recovered after surgery, the prognosis remains guarded due to the high risk of a recurrence. Tumours of the larynx in general and an infiltrative lipoma specifically should be added to the list of differential diagnosis in dogs presented with clinical signs that could be misinterpreted as laryngeal paralysis.

  10. Spindle Cell Lipoma Occurring in the Buccal Mucosa: An Unusual Location of This Benign Lipomatous Neoplasm

    PubMed Central

    Milhan, Noala Vicensoto Moreira; Cavalcante, Ana Sueli Rodrigues; Marques, Yonara Maria Freire Soares; Carvalho, Yasmin Rodarte; Anbinder, Ana Lia

    2015-01-01

    Spindle cell lipoma is a benign lipomatous neoplasm, which rarely occurs in the oral cavity. The aims of this paper are to report a case of spindle cell lipoma located in buccal mucosa and discuss the main clinical, histological, and immunohistochemical findings of this entity. Thus, we report a 4-year history of an asymptomatic smooth surface nodule in an elderly Caucasian man with clinical hypothesis of fibroma. The histopathological examination showed spindle cells, mature adipose tissue, and many mast cells in a stroma of connective tissue presenting ropey collagen fibers bundles. After immunohistochemical analysis, the final diagnosis was spindle cell lipoma. PMID:26491592

  11. Giant Cardiac Lipoma: Refined Hypothesis Proposes Invagination from Extracardiac to Intracardiac Sites

    PubMed Central

    Rainer, W. Gerald; Bailey, David J.

    2016-01-01

    Cardiac lipomas are rare and usually present as benign, encapsulated masses outside the heart; however, they can also be found within the atria. No single theory—including molecular genetic mutation—adequately explains why this occurs. Extensive career experience and broadened knowledge in embryology and cardiac physiology have helped us to develop a hypothesis based on invagination of extracardiac tumors. This report describes a vexing case of a giant right atrial lipoma, from 1985, in which the diagnosis was made incidentally during management of a patient's acute limb ischemia. In addition, we discuss the imaging and treatment of cardiac lipoma. PMID:27777537

  12. Histopathologic changes after intralesional application of phosphatidylcholine for lipoma reduction: report of a case.

    PubMed

    Kopera, Daisy; Binder, Barbara; Toplak, Hermann; Kerl, Helmut; Cerroni, Lorenzo

    2006-08-01

    Phosphatidylcholine, a lecithin extracted from soy beans, is able to lower serum cholesterol to some extent. When applied intralesionally within fat tissues, it is supposed to act as a "fat burner" and reduce undesired fat deposits. We applied intralesionally phosphatidylcholine within a lipoma of a young patient. To evaluate the volume of the lipoma sonographic imaging was performed before treatment and one month after the third application. Only a partial reduction of the lipoma could be achieved, and increased echographic density could be observed after the third intralesional application of phosphatidylcholine. Surgical excision was performed. Histologic examination showed focal fibrosis, inflammatory reaction with granulomatous features, and presence of pseudomembranous degeneration of fat tissue. Off-label intralesional use of phosphatidylcholine as "fat burner" for the reduction of aesthetically disturbing lipomas should be considered only on a case-to-case basis after careful consideration of possible undesired effects similar to those described in our patient.

  13. Spindle cell lipoma masquerading as lipomatous pleomorphic adenoma: A diagnostic dilemma on fine needle aspiration cytology.

    PubMed

    Agarwal, S; Nangia, A; Jyotsna, P Lalita; Pujani, M

    2013-01-01

    Spindle cell lipoma is a relatively uncommon benign adipocytic tumor that usually presents in subcutaneous fat of adult men. These are a rare form of lipoma, accounting for 1.5% of all lipomatous tumors, with a low rate of local recurrence and no risk of malignant behavior/dedifferentiation. Although few studies addressing the histological findings of spindle cell lipoma have been described, only a few descriptions of fine needle aspiration cytology (FNAC) findings have been documented in literature. We present a case of a 55-year-old male with a nodular swelling over left cheek (in the parotid region), which due to its location as well as prominent myxoid background prompted us to include the lipomatous salivary gland lesions in differential diagnosis. Our objective is to document and delineate the characteristic cytological features of spindle cell lipoma, which may permit a confident diagnosis on FNAC smears.

  14. Adult sigmoidorectal intussusception related to colonic lipoma: A rare case report with an atypical presentation

    PubMed Central

    Mohamed, Mohamed; Elghawy, Karim; Scholten, Donald; Wilson, Kenneth; McCann, Michael

    2015-01-01

    Introduction Adult intussusception is rare. Lipoma is the second most common benign tumor of the colon and most common to cause colonic intussusception in adults, but rare. Presentation of case A 35-years-old male presented with a history of intermittent abdominal pain and bright red rectal bleeding, with symptoms waxing and waning for one month. On physical examination, the abdomen was distended with tenderness over the periumbilical, suprapubic, and left lower quadrant regions with guarding. CT demonstrated colo-colonic intussusception of the sigmoid colon with a 2.3 cm × 2.6 cm intra-mural lipoma of the rectosigmoid region. The patient underwent an exploratory laparotomy with partial reduction of the intussusception, sigmoid colon resection and end colostomy. Histopathology confirmed a 2.5 cm sub-mucosal lipoma without evidence of malignancy. Discussion Sixty–sixty five percent of cases with intussusception of the large bowel in adults are related to a malignant etiology and most cases of sigmoidorectal intussusception reported in the literature are secondary to underlying malignancy. Colo-colic intussusception is the most common type of intussusception in adults. The incidence of lipomas of the large intestine is reported to range from 0.035% to 4.4%. Ninety percent of colonic lipomas are submuscosal and are mostly located in the right hemicolon. Only 25% of patients with colonic lipoma develop symptoms. Colonic lipomas of the rectosigmoid region represent a very rare occurrence and subsequent etiology for sigmoidorectal intussusceptions in adults. Conclusion Colonic lipoma should be considered in the differential diagnosis of adults with intussusception, with reduction and resection leading to excellent results. PMID:25839433

  15. Subdeltoid lipoma causing shoulder impingement syndrome – a case report

    PubMed Central

    Lenza, Mario; Lenza, Miguel Vicente; Carrerra, Eduardo da Frota; Ferretti, Mario

    2014-01-01

    The impingement syndrome is defined by the compression of the rotator cuff tendons against the coracoacromial arch. Several factors contribute to this condition and they are classified as structural or functional factors. The former are changes in the coracoacromial arch, proximal humerus, bursa and rotator cuff, and the latter are related to the mechanism of the upper limb by means of synchronized activity and balanced between the rotator cuff and scapular girdle muscles. The authors report here a case of parosteal lipoma of the proximal humerus, located between the muscles deltoid, teres minor and infraspinatus causing clinical signs of impingement. It is a rare occurrence, characterized as a structural cause for the onset of this symptom. PMID:25167335

  16. Targeted disruption of the mouse Lipoma Preferred Partner gene

    SciTech Connect

    Vervenne, Hilke B.V.K.; Crombez, Koen R.M.O.; Delvaux, Els L.; Janssens, Veerle; Ven, Wim J.M. van de Petit, Marleen M.R.

    2009-02-06

    LPP (Lipoma Preferred Partner) is a zyxin-related cell adhesion protein that is involved in the regulation of cell migration. We generated mice with a targeted disruption of the Lpp gene and analysed the importance of Lpp for embryonic development and adult functions. Aberrant Mendelian inheritance in heterozygous crosses suggested partial embryonic lethality of Lpp{sup -/-} females. Fertility of Lpp{sup -/-} males was proven to be normal, however, females from Lpp{sup -/-} x Lpp{sup -/-} crosses produced a strongly reduced number of offspring, probably due to a combination of female embryonic lethality and aberrant pregnancies. Apart from these developmental and reproductive abnormalities, Lpp{sup -/-} mice that were born reached adulthood without displaying any additional macroscopic defects. On the other hand, Lpp{sup -/-} mouse embryonic fibroblasts exhibited reduced migration capacity, reduced viability, and reduced expression of some Lpp interaction partners. Finally, we discovered a short nuclear form of Lpp, expressed mainly in testis via an alternative promoter.

  17. Perineal lipoma in a newborn boy--a case report.

    PubMed

    Bataille, D; Donner, C; Cassart, M; Pardou, A; Nagy, N; Van Hoorde, E; Lingier, P

    2007-04-01

    We report the case of a newborn presenting with a pediculated mass arising from the anal margin. Antenatal sonogram and magnetic resonance imaging were unable to diagnose the precise nature of the lesion. Sacrococcygeal teratoma, an enterogenous cyst, a polyp, a prolapse or other perineal tumors were all proposed as possible entities. At birth, no other anatomic anomaly than this homogenous 2 cm para-anal lesion was seen. Excision of the mass was performed under general anesthesia. The postoperative histological exam showed mature fat cells. Reviewing the literature, there have been few previously reported cases of congenital perineal lipoma. It is a rare, benign and easy-to-treat condition that can be evocated by morphological sonography or magnetic resonance imaging (MRI). PMID:17503310

  18. Congenital Giant Keratinous Cyst Mimicking Lipoma: Case Report and Review

    PubMed Central

    Sabhlok, Samrat; Kalele, Ketki; Phirange, Asmita; Kheur, Supriya

    2015-01-01

    Epidermal cysts represent the most common cutaneous cysts. They arise following a localized inflammation of the hair follicle and occasionally after the implantation of the epithelium, following a trauma or surgery. Conventional epidermal cysts are about 5 cm in diameter; however, rare reports of cysts more than 5 cm are reported in the literature and are referred as “Giant epidermal cysts.” Epidermal cysts although common, can mimic other common benign lesions in the head and neck area. A thorough clinico-pathologic investigation is needed to diagnose these cutaneous lesions as they differ in their biologic behavior, treatment, and prognosis. We report a case of a giant epidermoid cyst in the scalp area of a young female patient which mimicked lipoma on clinical, as well as cyotological examination. We also present a brief review of epidermal cysts, their histopathological differential diagnosis, and their malignant transformation. PMID:26677303

  19. Combined liposuction and excision of lipomas: long-term evaluation of a large sample of patients.

    PubMed

    Copeland-Halperin, Libby R; Pimpinella, Vincenza; Copeland, Michelle

    2015-01-01

    Background. Lipomas are benign tumors of mature fat cells. They can be removed by liposuction, yet this technique is seldom employed because of concerns that removal may be incomplete and recurrence may be more frequent than after conventional excision. Objectives. We assessed the short- and long-term clinical outcomes and recurrence of combined liposuction and limited surgical excision of subcutaneous lipomas. Methods. From 2003 to 2012, 25 patients with 48 lipomas were treated with liposuction followed by direct excision through the same incision to remove residual lipomatous tissue. Initial postoperative follow-up ranged from 1 week to 3 months, and long-term outcomes, complications, and recurrence were surveyed 1 to 10 years postoperatively. Results. Lipomas on the head, neck, trunk, and extremities ranged from 1 to 15 cm in diameter. Early postoperative hematoma and seromas were managed by aspiration. Among 23 survey respondents (92%), patients were uniformly pleased with the cosmetic results; none reported recurrent lipoma. Conclusions. The combination of liposuction and excision is a safe alternative for lipoma removal; malignancy and recurrence are uncommon. Liposuction performed through a small incision provides satisfactory aesthetic results in most cases. Once reduced in size, residual lipomatous and capsular tissue can be removed without expanding the incision. These favorable outcomes support wider application of this technique in appropriate cases. PMID:25694827

  20. Combined Liposuction and Excision of Lipomas: Long-Term Evaluation of a Large Sample of Patients

    PubMed Central

    Copeland-Halperin, Libby R.; Pimpinella, Vincenza

    2015-01-01

    Background. Lipomas are benign tumors of mature fat cells. They can be removed by liposuction, yet this technique is seldom employed because of concerns that removal may be incomplete and recurrence may be more frequent than after conventional excision. Objectives. We assessed the short- and long-term clinical outcomes and recurrence of combined liposuction and limited surgical excision of subcutaneous lipomas. Methods. From 2003 to 2012, 25 patients with 48 lipomas were treated with liposuction followed by direct excision through the same incision to remove residual lipomatous tissue. Initial postoperative follow-up ranged from 1 week to 3 months, and long-term outcomes, complications, and recurrence were surveyed 1 to 10 years postoperatively. Results. Lipomas on the head, neck, trunk, and extremities ranged from 1 to 15 cm in diameter. Early postoperative hematoma and seromas were managed by aspiration. Among 23 survey respondents (92%), patients were uniformly pleased with the cosmetic results; none reported recurrent lipoma. Conclusions. The combination of liposuction and excision is a safe alternative for lipoma removal; malignancy and recurrence are uncommon. Liposuction performed through a small incision provides satisfactory aesthetic results in most cases. Once reduced in size, residual lipomatous and capsular tissue can be removed without expanding the incision. These favorable outcomes support wider application of this technique in appropriate cases. PMID:25694827

  1. Does this baby have a tail?: a case of congenital isolated perineal lipoma presenting as human pseudo-tail.

    PubMed

    Kim, Soo-Hong; Cho, Yong Hoon; Kim, Hae Young

    2016-01-01

    A pseudo-tail is defined as a tail-like lesion in the lumbosacrococcygeal region that is not a true tail but one caused by disease. Perineal lipoma is one of the conditions that may present as a pseudo-tail. Congenital perineal lipoma is a rare disease and in particular, isolated congenital perineal lipoma without other anomalies is extremely rare. Here we report a case of congenital isolated perineal lipoma presenting as a pseudo-tail and also include a literature review of the condition.

  2. Does this baby have a tail?: a case of congenital isolated perineal lipoma presenting as human pseudo-tail

    PubMed Central

    Kim, Soo-Hong; Cho, Yong Hoon

    2016-01-01

    A pseudo-tail is defined as a tail-like lesion in the lumbosacrococcygeal region that is not a true tail but one caused by disease. Perineal lipoma is one of the conditions that may present as a pseudo-tail. Congenital perineal lipoma is a rare disease and in particular, isolated congenital perineal lipoma without other anomalies is extremely rare. Here we report a case of congenital isolated perineal lipoma presenting as a pseudo-tail and also include a literature review of the condition. PMID:26793694

  3. Lipoma arborescens arising in the extra-articular bursa of the knee joint.

    PubMed

    Minami, Shinji; Miyake, Yusuke; Kinoshita, Hirofumi

    2016-01-01

    Lipoma arborescens arising in the extra-articular bursa of the knee joint is extremely rare. We describe an 11-year-old boy who complained of a gradual swelling mass of the lateral knee joint. Magnetic resonance imaging (MRI) showed a high signal intensity tumor on T1- and T2-weighted images with a thickened septa and nodular lesion that showed low signal intensity. The radiologist suggested the possible differential diagnosis of well-differentiated liposarcoma. At operation, the tumor was found under the iliotibial tract and was not in contact with the knee joint. Histopathologically, this lesion was diagnosed as lipoma arborescens arising in the extra-articular bursa of the knee joint. On MRI, the appearance of lipoma arborescens arising in the extra-articular bursa of the knee joint differed from that of conventional intra-articular lipoma arborescens. In this report, we describe a case of extra-articular lipoma arborescens of the knee joint bursa and discuss the diagnosis and etiology. PMID:27382924

  4. Lipoma arborescens arising in the extra-articular bursa of the knee joint

    PubMed Central

    Minami, Shinji; Miyake, Yusuke; Kinoshita, Hirofumi

    2016-01-01

    Lipoma arborescens arising in the extra-articular bursa of the knee joint is extremely rare. We describe an 11-year-old boy who complained of a gradual swelling mass of the lateral knee joint. Magnetic resonance imaging (MRI) showed a high signal intensity tumor on T1- and T2-weighted images with a thickened septa and nodular lesion that showed low signal intensity. The radiologist suggested the possible differential diagnosis of well-differentiated liposarcoma. At operation, the tumor was found under the iliotibial tract and was not in contact with the knee joint. Histopathologically, this lesion was diagnosed as lipoma arborescens arising in the extra-articular bursa of the knee joint. On MRI, the appearance of lipoma arborescens arising in the extra-articular bursa of the knee joint differed from that of conventional intra-articular lipoma arborescens. In this report, we describe a case of extra-articular lipoma arborescens of the knee joint bursa and discuss the diagnosis and etiology. PMID:27382924

  5. Persistence of CD34 Stem Marker in Human Lipoma: Searching for Cancer Stem Cells

    PubMed Central

    Zavan, Barbara; De Francesco, Francesco; D'Andrea, Francesco; Ferroni, Letizia; Gardin, Chiara; Salzillo, Rosa; Nicoletti, Gianfranco; Ferraro, Giuseppe A.

    2015-01-01

    Background: Lipomas are benign solid tumours that develop in soft tissues with origin in mesenchymal progenitors. Macroscopically, they appear as soft-elastic nodules, varying in volume from a few millimiters to several centimetres and can enlarge progressively. Although they are usually asymptomatic, they can cause symptoms due to nerve or vessel compression. Microscopically they appear as fibrous connective tissue stroma with embedded adipocytes, and absence of inflammation. Up to now no characterisation of stem cell population present in this tissue has been performed. Methods: Cytofluorimetric, biological and molecular biology analyses have been performed in order to test superficial cell markers and gene expression profile related to stemness and apoptotic activity of cells present in lipoma tissues compared to those of adipose tissue's cells. Results: Our results confirmed that CD34+ cells in lipoma were present around small adipocytes, showing several altered biological activity such as proliferation, apoptotis and stemness. Conclusions: The data emerging from the comparison of the lipoma cells and normal adipose tissue, suggests the presence of cell precursors involved in the development of the lipoma. This hypothesis requires further investigation and may indicate new thresholds in the study of benign tumour pathogenesis. PMID:26327807

  6. Treatment for Intramuscular Lipoma Frequently Confused with Sarcoma: A 6-Year Restrospective Study and Literature Review

    PubMed Central

    Choi, Jong Yun; Seo, Bommie F.; Oh, Deuk Young; Ahn, Sang Tae; Rhie, Jong Won

    2014-01-01

    Introduction. Intramuscular lipoma is a very rare form of lipoma, known to be categorized as an infiltrating lipoma due to its tendencies to infiltrate the muscle or the synovium. Contrary to other subcutaneous lipomas, even after surgical removal, the rate of local recurrence ranges at a high rate from 50∼80% and differential diagnosis with liposarcoma is very difficult. Patients and Methods. A retrospective chart review was conducted for a total of 27 patients. Before performing a surgery based on the types of mass, a radiologic imaging study was performed. An intraoperative frozen biopsy was performed on every patient and the results were compared. The progress was monitored every 3 to 6 months for recurrence or struggles with rehabilitation. Results. There were 13 male and 14 female patients with an average age of 54.6. The average tumor size was 8.2 cm (1.1 cm∼31.6 cm). Excision was performed using a wide excision. All 27 individuals were initially diagnosed as intramuscular lipoma; however, 1 of the patients was rediagnosed as liposarcoma in the final checkup. The patients had an average of 3 years and 1 month of follow-up and did not suffer recurrences. Conclusion. Thus, it is essential that a frozen biopsy is performed during the surgery in order to identify its malignancy. And a wide excision like malignant tumor operation is a principle of treatment. PMID:25574469

  7. Lipomas of the oral cavity: clinicopathological and immunohistochemical study of 24 cases and review of the literature.

    PubMed

    Naruse, Tomofumi; Yanamoto, Souichi; Yamada, Shin-Ichi; Rokutanda, Satoshi; Kawakita, Akiko; Takahashi, Hidenori; Matsushita, Yuki; Hayashida, Saki; Imayama, Naomi; Morishita, Kota; Yamashita, Kentaro; Kawasaki, Goro; Umeda, Masahiro

    2015-03-01

    Although lipomas are common soft tissue tumors, few cases of lipoma or its variants have been reported in the oral cavity. We here described the clinical, histological, and immunohistochemical features of 24 cases of oral lipoma obtained from medical records at Nagasaki University Hospital between 1977 and 2010, and also retrospectively reviewed 603 cases of oral lipoma reported in the English literatures. The patients examined comprised 11 men and 13 women with a mean age of 59 years, ranging from 31 to 90 years. The main sites involved were the buccal mucosa (n = 9), followed by the tongue (n = 4), lip and retromolar area (n = 3), floor of the mouth (n = 2), and gingiva (n = 1). The mean tumor size was 2.0 cm, ranging from 0.2 to 5 cm. Histological analysis revealed 20 cases of lipoma, 2 cases of fibrolipoma, and one case each of intramuscular lipoma and spindle cell lipoma. Twenty-three cases were treated surgically while one case underwent biopsy and follow-up. Recurrence was not observed in any case. We reviewed the English literatures, and similar results were obtained. In immunohistochemical analysis, PCNA and ki-67 expression indices were higher in intramuscular lipoma cases than in its variants. Especially, it showed that a long time follow-up may be necessary in ki-67 positive cases.

  8. Chronic lingual ulceration caused by lipoma of the oral cavity. Case report.

    PubMed

    Del Castillo Pardo de Vera, Jose Luis; Cebrián Carretero, Jose Luis; Gómez García, Elena

    2004-01-01

    Although lipomas are among the most frequent tumors in the human body, their presentation in the oral cavity is not common. Oral cavity lipomas usually show a slow painless and assymptomatic growing. When these tumors reach big sizes, they can cause compressive symptons and deformities. In this paper we present the case of a patient in whom oral lipoma was the final finding in the differential diagnosis of a chronic mucosal ulcer. CT scan and MRI images and microscopical examination after fine-needle aspiration were the clue for the final diagnosis. The surgical excision of the tumor was the basis for the healing of the ulcer. We also review the most relevant and recent literature about clinic, diagnosis and treatment for these tumors.

  9. Lipoma of mandibular buccal vestibule: a case with histopathological literature review.

    PubMed

    Mehendirratta, Monica; Jain, Kanu; Kumra, Madhumani; Manjunatha, Bhari Sharanesha

    2016-01-01

    Lipoma is a tumour of soft tissue with rare occurrence in oral cavity accounting for only 1-4% of benign oral tumours. Most common sites of involvement are the buccal mucosa, tongue and floor of the mouth with typical presentation of an asymptomatic, soft, smooth-surfaced, nodular and yellowish mass. Histopathologically, a classical lipoma resembles normal adipose tissue and it has multiple variants which are less commonly seen except fibrolipoma. The article presents a case report of a relatively large oral classical lipoma in a 60-year-old man on a rare site, mandibular buccal vestibule, along with a review of the literature and special emphasis on its various histopathological variants. PMID:27489068

  10. Complications arising from a misdiagnosed giant lipoma of the hand and palm: a case report

    PubMed Central

    2011-01-01

    Introduction Lipomas are benign tumors which may appear in almost any human organ. Their diagnosis rate in the hand region is not known. Case Presentation We present the case of a 63-year-old Greek Caucasian woman with a giant lipoma of the hand and palm which was not initially diagnosed. After repeated surgical decompression of the carpal tunnel the patient was referred with persisting symptoms of median and ulnar nerve compression and a prominent mass of her left palm and thenar eminence. Clinical examination, magnetic resonance imaging, nerve conduction study and biopsy, revealed a giant lipoma in the deep palmar space (8.0 × 4.0 × 3.75 cm), which was also infiltrating the carpal tunnel. She had already undergone two operations for carpal tunnel syndrome with no relief of her symptoms and she also ended up with a severed flexor pollicis longus tendon. Definitive treatment was performed by marginal resection of the lipoma and restoration of the flexor pollicis longus with an intercalated graft harvested from the palmaris longus. Thirty months after surgery the patient had a fully functional hand without any neurological deficit. Conclusion Not all lipomas of the wrist and hand are diagnosed. Our report tries to emphasize the hidden danger of lipomas in cases with carpal tunnel symptoms. The need for a high index of suspicion in conjunction with good clinical evaluation and the use of appropriate investigative studies is mandatory in order to avoid unnecessary operations and complications. Marginal excision of these tumors is restorative. PMID:22085433

  11. Coincidence of congenital infiltrative facial lipoma and lingual myxoma in a newborn Holstein calf.

    PubMed

    Hobbenaghi, R; Dalir-Naghadeh, B; Nazarizadeh, A

    2015-01-01

    A one-day-old male Holstein calf was presented with a palpable subcutaneous mass, extending from the parotid to the orbital region, involving the entire right side of the face and a large flabby mass without any evidence of inflammation or edema on the tongue. Macroscopically, the cut surface of the lingual mass appeared slightly lobulated, pink, with a mucoid appearance and gelatinous consistency. Histopathological examination confirmed the infiltrative subcutaneous lipoma and lingual myxoma evidenced by low cellularity and abundant basophilic, mucinous stroma. In this report, clinical and detailed histhopathological findings of congenital infiltrative myxoma and its coincidence with infiltrative facial lipoma is reported in a newborn calf.

  12. Coincidence of congenital infiltrative facial lipoma and lingual myxoma in a newborn Holstein calf.

    PubMed

    Hobbenaghi, R; Dalir-Naghadeh, B; Nazarizadeh, A

    2015-01-01

    A one-day-old male Holstein calf was presented with a palpable subcutaneous mass, extending from the parotid to the orbital region, involving the entire right side of the face and a large flabby mass without any evidence of inflammation or edema on the tongue. Macroscopically, the cut surface of the lingual mass appeared slightly lobulated, pink, with a mucoid appearance and gelatinous consistency. Histopathological examination confirmed the infiltrative subcutaneous lipoma and lingual myxoma evidenced by low cellularity and abundant basophilic, mucinous stroma. In this report, clinical and detailed histhopathological findings of congenital infiltrative myxoma and its coincidence with infiltrative facial lipoma is reported in a newborn calf. PMID:27175195

  13. Multiple dermal lipomas in farmed striped seabream Lithognathus mormyrus on the Spanish Mediterranean coast.

    PubMed

    Gómez, Serafín

    2009-05-27

    Two cases of multiple dermal lipomas were found in cultured striped seabream Lithognathus mormyrus (L.) from the southeast coast of Spain. A histopathological study suggests that pigmented cells may correspond to melanomacrophage aggregates. The presence of these aggregations is likely related to the occurrence of a pathological process of tumoral nature.

  14. Molecular characterization of the t(4;12)(q27~28;q14~15) chromosomal rearrangement in lipoma

    PubMed Central

    Agostini, Antonio; Gorunova, Ludmila; Bjerkehagen, Bodil; Lobmaier, Ingvild; Heim, Sverre; Panagopoulos, Ioannis

    2016-01-01

    Lipomas are common benign soft tissue tumors whose genetic and cytogenetic features are well characterized. The karyotype is usually near- or pseudodiploid with characteristic structural chromosomal aberrations. The most common rearrangements target the high mobility group AT-hook 2 (HMGA2) gene in 12q14.3, with breakpoints occurring within or outside of the gene locus leading to deregulation of HMGA2. The most common fusion partner for HMGA2 in lipoma is lipoma-preferred partner (3q27), but also other genes frequently recombine with HMGA2. Furthermore, truncated HMGA2 transcripts are recurrently observed in lipomas. The present study describes 5 lipomas carrying the translocation t(4;12)(q27~28;q14~15) as the sole chromosomal anomaly, as well as 1 lipoma in which the three-way translocation t(1;4;12)(q21;q27~28;q14~15) was identified. Molecular analyses performed on 4 of these cases detected 4 truncated forms of HMGA2. In 3 tumors, the HMGA2 truncated transcripts included sequences originating from the chromosomal sub-band 4q28.1. Notably, in 2 of these cases, the fourth exon of HMGA2 was fused to transposable elements located in 4q28.1. PMID:27588119

  15. A 4-cm lipoma of the transverse colon causing colonic intussusception: A case report and literature review

    PubMed Central

    ZHOU, XIAO-CONG; HU, KE-QIONG; JIANG, YI

    2014-01-01

    Colonic lipomas are rare benign tumors. Colonic intussusception is an uncommon complication of colonic lipoma. The current study presents an unusual case of a 4-cm symptomatic lipoma of the transverse colon causing colonic intussusception. A 65-year-old female was admitted to Wenzhou Central Hospital (Wenzhou, Zhejiang, China) with intermittent pain in the left abdomen that had been present for two weeks. Colonoscopy revealed a 4×5-cm intraluminal spherical mass with erosional mucosa 60 cm above the anal verge, indicating the presence of a malignant gastrointestinal stromal tumor. Contrast-enhanced computed tomography revealed a well-defined fatty tissue mass of 4 cm in diameter in the distal transverse colon proximal to the splenic flexure, with intussusception. The patient underwent segmental resection of the transverse colon and intraoperative frozen sections were obtained. The intraoperative frozen sections revealed a submucosal lipoma of the transverse colon and thus, a conclusive diagnosis was achieved. The patient was followed up for one year and 10 months following the segmental resection of the transverse colon, with a good prognosis. This study may increase clinical awareness with regard to colonic lipomas. Furthermore, open surgery combined with use of intraoperative frozen sections should be recommended for large symptomatic colonic lipomas accompanied by colonic intussusception, thus avoiding unnecessary radical resection and improving patient prognosis. PMID:25120663

  16. A Case Report of Curettage and Kryptonite® use in Proximal Femur Intraosseous Lipoma

    PubMed Central

    Salgado, Martín; Córdova, Cecilia; Avilés, Carolina; Fernández, Felipe

    2016-01-01

    Introduction: Intraosseous lipomas are the most infrequent primary bone tumor, lesions are mainly asymptomatic and generally diagnosed incidentally, and there is controversy about the management. Here, we present a surgery solution that has not been described previously in literature. Case Presentation: A 23-year-old female without previous morbid history consults a general physician because of unspecific left hip pain when walking, not related to any previous trauma or any other symptoms. In her study, radiography of the sore hip showed a radiopaque lesion with lithic aspect at the neck of the left femur. Conclusion: Intraosseous lipoma, in spite of being a rare condition, can be diagnosed incidentally by its radiologic characteristics. The treatment can be based on observation or surgery in particular cases objectified by clinic and Mirel score.

  17. Single-incision video-assisted anatomical segmentectomy with handsewn bronchial closure for endobronchial lipoma.

    PubMed

    Galvez, Carlos; Sesma, Julio; Bolufer, Sergio; Lirio, Francisco; Navarro-Martinez, Jose; Galiana, Maria; Baschwitz, Benno; Rivera, Maria Jesus

    2016-08-01

    Endobronchial lipomas are rare benign tumors whose symptoms are usually confused with recurrent infections or even asthma diagnosis, and mostly caused by endobronquial obstructive component which also conditions severity. We report a case of a 60-year-old man with a right-lower lobe upper-segment endobronchial myxoid tumor with uncertain diagnosis. We performed a single incision video-assisted anatomical segmentectomy and wedge bronchoplasty with handsewn closure to achieve complete resection and definitive diagnosis. During the postoperative air leak was not observed and there was no complication, with low pain scores and complete recovery. Final pathological exam showed endobronchial lipoma. Single-incision (SI) anatomical segmentectomies are lung-sparing resections for benign or low-grade malignancies with diagnostic and therapeutic value, and the need for a wedge bronchoplasty is not a necessary indication for conversion to multiport or open thoracotomy. PMID:27570778

  18. Accessory scrotum with perineal lipoma diagnosed prenatally: case report and review of the literature.

    PubMed

    Murase, Naruhiko; Uchida, Hiroo; Hiramatsu, Kiyoshi

    2015-08-01

    We report a case of accessory scrotum (AS) in the perineal region with peduncular lipoma, diagnosed prenatally. A male fetus of 31 weeks' gestation was referred to our department with a perineal mass. Prenatal ultrasonography and magnetic resonance imaging showed a mass of 1.0 × 1.2 cm located posterior to the scrotum. No other abnormalities were noted during pregnancy. The patient was delivered vaginally at 38 weeks of gestation. On physical examination, a soft peduncular mass with a rugged and pigmented swelling was located between the normally developed scrotum and the anus. There were no specific symptoms or any other associated congenital anomalies. We completely excised the mass at one month of age. A histological examination revealed lipoma, with tissue suggestive of scrotum, so a definite diagnosis of AS was made. AS is a rare congenital anomaly of the scrotum. We review the literature. PMID:26412897

  19. Spindle Cell Lipoma of the Neck: Review of the Literature and Case Report

    PubMed Central

    Machol, Jacques A.; Cusic, Jenna G.; O'Connor, Elizabeth A.; Sanger, James R.

    2015-01-01

    Summary: Spindle cell lipomas (SCL) are benign, slow growing tumors arising most frequently in the subcutaneous tissue of the upper back, posterior neck, and shoulders in males aged 40–70 years. Local excision is generally curative. Classification of lipomatous tumors has progressed recently, and tumors of similar morphology and unusual presentation are increasingly reported, thereby making correct diagnosis even more vital. SCL require pathologic differentiation from liposarcoma, other spindle cell neoplasms, and myxoid lesions for treatment purposes. Cytology, histology, and cytogenetics, in conjunction with clinical presentation, are paramount in arriving at the correct diagnosis of spindle cell lipoma. We present a case report with characteristics typical of an SCL along with a literature review to further elucidate the diagnosis and surgical treatment of this soft tissue tumor. PMID:26893975

  20. Single-incision video-assisted anatomical segmentectomy with handsewn bronchial closure for endobronchial lipoma

    PubMed Central

    Sesma, Julio; Bolufer, Sergio; Lirio, Francisco; Navarro-Martinez, Jose; Galiana, Maria; Baschwitz, Benno; Rivera, Maria Jesus

    2016-01-01

    Endobronchial lipomas are rare benign tumors whose symptoms are usually confused with recurrent infections or even asthma diagnosis, and mostly caused by endobronquial obstructive component which also conditions severity. We report a case of a 60-year-old man with a right-lower lobe upper-segment endobronchial myxoid tumor with uncertain diagnosis. We performed a single incision video-assisted anatomical segmentectomy and wedge bronchoplasty with handsewn closure to achieve complete resection and definitive diagnosis. During the postoperative air leak was not observed and there was no complication, with low pain scores and complete recovery. Final pathological exam showed endobronchial lipoma. Single-incision (SI) anatomical segmentectomies are lung-sparing resections for benign or low-grade malignancies with diagnostic and therapeutic value, and the need for a wedge bronchoplasty is not a necessary indication for conversion to multiport or open thoracotomy. PMID:27570778

  1. Invasive Ductal Breast Carcinoma Underneath a Lipoma in a Male Patient

    PubMed Central

    Landero, James; Glick, Bradley P.

    2012-01-01

    Male breast cancer is a rare malignancy and accounts for less than one percent of all cancers in men. The authors describe the case of a 76-year-old Caucasian man with invasive ductal breast carcinoma who presented with a common lipoma. This paper reviews the current literature on epidemiology, risk factors, etiology, different types of breast cancer, clinical presentation, imaging, diagnostic workup, and treatment. PMID:23125888

  2. [Intrapericardial lipoma with stenosis of the left bronchus and pulmonary artery].

    PubMed

    Nemoto, S; Fujimura, M; Nishiya, Y; Hamawaki, M; Miwa, A; Takabatake, S

    1992-02-01

    In a 1-year-6 month-old girl with asthma, a chest magnetic resonance imaging revealed an intrapericardial lipoma at the site of the transverse sinus behind the great arteries. The tumor compressed the left bronchus and pulmonary artery resulting in the stenosis. Under cardiopulmonary bypass, the tumor was successfully removed. The stenosis of the left bronchus and pulmonary artery were released. PMID:1593168

  3. Lipoma Arborescens: Review of an Uncommon Cause for Swelling of the Knee

    PubMed Central

    De Vleeschhouwer, M.; Van Den Steen, E.; Vanderstraeten, G.; Huysse, W.; De Neve, J.; Vanden Bossche, L.

    2016-01-01

    Lipoma arborescens is a rare cause of chronic monoarticular arthritis, with only a few cases reported in the literature. It is most commonly seen in the knee, but cases in other joints such as the wrist, shoulder, and elbow have also been described. It is a benign condition, in which the subsynovial tissue is replaced diffusely by mature fat cells. We describe a case involving the knee and discuss the symptoms, diagnosis, and treatment. PMID:27293937

  4. Resolution of intussusception after spontaneous expulsion of an ileal lipoma per rectum: a case report and literature review

    PubMed Central

    2014-01-01

    We herein report a case of spontaneous rectal expulsion of an ileal lipoma in a 65-year-old female patient who presented with recurrent attacks of subacute intestinal obstruction. During each episode, the patient developed severe abdominal pain and expelled a fleshy mass from her rectum. The fleshy mass was histopathologically diagnosed as a lipoma comprising fat cells, fibers, and blood vessels. Upon expulsion, the pain disappeared and the intussusception was immediately resolved. Colonoscopic examination revealed a 2.5-cm diameter ulcerated lesion near the ileocecal valve, which was confirmed to be inflammation by pathological examination. A subsequent barium series revealed a normal colonic tract, and the patient remained completely symptom-free for 4 months after the incident. According to the relevant literature and our clinical experience, the treatment method for a lipoma depends on the patient’s clinical manifestations and the size of the tumor. However, the various diagnostic and therapeutic modalities currently available continue to be debated; whether an asymptomatic lipoma requires treatment is controversial. When histopathological examination results allow for the exclusion of malignant lesions such as sarcoma, a lipoma can be resected surgically. PMID:24884620

  5. Endoscopic ligation (“Loop-And-Let-Go”) is effective treatment for large colonic lipomas: a prospective validation study

    PubMed Central

    2014-01-01

    Background Colonic lipomas (CL) are rare benign adipose tumours usually found incidentally during colonoscopy. Endoscopic resection of symptomatic large CL remains controversial, since significant rates of perforation have been reported. In recent years, a novel technique for removal of large CL has been described, consisting of looping and ligating the lipoma with a nylon snare. The aim of our study was to evaluate the safety and efficacy of the “loop and let go” technique for large colon lipomas in a large case series. Methods Consecutive patients referred to our institution for colonoscopy were eligible for the study. The diagnosis of CL was confirmed endoscopically by “pillow” and “naked fat” signs. Following diagnosis, lipomas were looped and ligated by endoloop. Follow-up colonoscopies were scheduled at 1- and 3-months interval. Results A total of 11 patients with large CL were enrolled in study. The indications for the colonoscopy included altered bowel habits (7 patients, 64%), screening for colorectal neoplasm (3 pts, 27%) and lower gastrointestinal bleeding (1 pts, 9%). The median lesion size was 3 cm (range 2,5-6 cm). Lesions were located at the hepatic flexure in 4 patients (36%), cecum and ascending colon (4 pts, 36%), rectosigmoid (2 pts, 18%) and transverse colon (1 pts, 9%). There were no immediate and late complications. On follow-up (median follow-up time 11,9 months, range 8–24), there was one small residual lipoma (<1 cm). Conclusion The results of this study confirm that “loop-and-let-go” technique is safe and efficacious treatment of large colonic lipomas. PMID:25005025

  6. Bilateral redundancy gain and callosal integrity in a man with callosal lipoma: a diffusion-tensor imaging study.

    PubMed

    Roser, Matthew E; Corballis, Michael C; Jansari, Ashok; Fulford, Jon; Benattayallah, Abdelmalek; Adams, William M

    2012-06-01

    We investigated whether abnormalities in the structural organization of the corpus callosum in the presence of curvilinear lipoma are associated with increased facilitation of response time to bilateral stimuli, an effect known as the redundancy gain (RG). A patient (A.J.) with a curvilinear lipoma of the corpus callosum, his genetically-identical twin, and age-matched control participants made speeded responses to luminant stimuli. Structural organization of callosal regions was assessed with diffusion-tensor imaging. A.J. was found to have reduced structural integrity in the splenium of the corpus callosum and produced a large RG suggestive of neural summation. PMID:21787244

  7. A Case Report of X-Linked Hyperimmunoglobulin M Syndrome with Lipoma Arborescens of Knees

    PubMed Central

    Yao, Zhongqiang; Liu, Xiangyuan

    2016-01-01

    The X-linked hyperimmunoglobulin M syndrome (HIGM), caused by mutations in the CD40LG gene, is a kind of primary immunodeficiency disease (PID). Patients with X-linked HIGM are susceptible to infection as well as autoimmune diseases. Lipoma arborescens (LA) is a rare benign tumor, of which the pathogenesis mechanism has not been clearly understood. We report a case of HIGM combined with LA in a 22-year-old male patient. A new deletion mutation of CD40LG gene was detected in this case. The possible relationship between HIGM and LA was also discussed.

  8. Arthroscopic Marginal Resection of a Lipoma of the Supraspinatus Muscle in the Subacromial Space

    PubMed Central

    Pagán Conesa, Alejandro; Aznar, Carlos Verdú; Herrera, Manuel Ruiz; Lopez-Prats, Fernando Anacleto

    2015-01-01

    Subacromial impingement syndrome is a common cause of shoulder pain in young adults and seniors at present. The etiology of this syndrome is associated with several shoulder disorders, most related to aging, overhead activities, and overuse. The subacromial space is well circumscribed and limited in size, and soft-tissue growing lesions, such as tumors, can endanger the normal function of the shoulder girdle. We present a case of shoulder impingement syndrome caused by an intramuscular lipoma of the supraspinatus muscle in the subacromial space in a 50-year-old male bank manager. Radiographs, magnetic resonance imaging, and a computed tomography scan showed a well-circumscribed soft-tissue tumor at the supraspinatus-musculotendinous junction. It was arthroscopically inspected and dissected and complete marginal excision was performed through a conventional augmented anterolateral portal, avoiding the need to open the trapezius fascia or perform an acromial osteotomy. Microscopic study showed a benign lipoma, and the shoulder function of the patient was fully recovered after a rehabilitation period of 4 months. This less invasive technique shows similar results to conventional open surgery. PMID:26759779

  9. Lipoma of Piriform Sinus: A Case Report and Review of the Literature

    PubMed Central

    Acquaviva, Gilberto; Badia, Stefano; Casorati, Francesco; Bellocchi, Gianluca

    2016-01-01

    The lipomas of oropharynx, hypopharynx, and larynx are so rare that up to now approximately there have been 100 cases reported. The lipomas are slow-growing lesions that are capable of reaching considerable dimensions and are often detected at a late stage. The symptoms can vary both in dimension and in location, semiobstructing the aerodigestive tract or exerting compression on adjacent structure. In this case, the lesion, which originated from the piriform sinus, was removed endoscopically urgently due to obvious signs of tissue suffering caused by stretching of the pedicle as a result of displacement of the mass. The two aims of this case report are to expose an interesting and rare case study mainly for an Emergency Room Specialist and an ENT (Ear, Nose, and Throat) Specialist involved in solving the problem and to demonstrate that the choice of an endoscopic approach is useful in order to have an optimal visualization of the lesion and to perform a total eradication. The use of endoscopic devices also allows a rapid postoperative recovery, compared to external access and optimum locoregional control in the follow-up procedures to prevent possible relapses. PMID:27795863

  10. Arthroscopic Marginal Resection of a Lipoma of the Supraspinatus Muscle in the Subacromial Space.

    PubMed

    Pagán Conesa, Alejandro; Aznar, Carlos Verdú; Herrera, Manuel Ruiz; Lopez-Prats, Fernando Anacleto

    2015-08-01

    Subacromial impingement syndrome is a common cause of shoulder pain in young adults and seniors at present. The etiology of this syndrome is associated with several shoulder disorders, most related to aging, overhead activities, and overuse. The subacromial space is well circumscribed and limited in size, and soft-tissue growing lesions, such as tumors, can endanger the normal function of the shoulder girdle. We present a case of shoulder impingement syndrome caused by an intramuscular lipoma of the supraspinatus muscle in the subacromial space in a 50-year-old male bank manager. Radiographs, magnetic resonance imaging, and a computed tomography scan showed a well-circumscribed soft-tissue tumor at the supraspinatus-musculotendinous junction. It was arthroscopically inspected and dissected and complete marginal excision was performed through a conventional augmented anterolateral portal, avoiding the need to open the trapezius fascia or perform an acromial osteotomy. Microscopic study showed a benign lipoma, and the shoulder function of the patient was fully recovered after a rehabilitation period of 4 months. This less invasive technique shows similar results to conventional open surgery. PMID:26759779

  11. Folliculosebaceous Cystic Hamartoma With Spindle Cell Lipoma-Like Stromal Features

    PubMed Central

    Skupsky, Hadas; Cassarino, David

    2015-01-01

    Abstract: Folliculosebaceous cystic hamartoma is a distinctive cutaneous hamartoma composed of follicular, sebaceous, and mesenchymal components. The lesions are most commonly found on the face and scalp of young adults, with approximately 30% occurring in the nasal or paranasal regions of the face. The clinical differential diagnoses are extensive and include epidermoid cyst, dermal nevus, soft fibroma, and adnexal tumors including sebaceous neoplasms. Here, the authors present a case of a 24-year-old man who presented for evaluation of an asymptomatic growth on the nose, which had slowly enlarged over 9 years. On examination, there was a 0.6 cm dome-shaped flesh-colored papule on the nasal bridge. The clinical differential included dermatofibroma versus intradermal nevus. A shave biopsy was performed, and histological examination of the sections showed a proliferation of multiple enlarged and irregular-appearing sebaceous glands attached to a cystic follicular structure. The associated dermal mesenchymal component consisted of numerous mature-appearing adipocytes associated with a fibromyxoid stroma, prominent collections of mucin, and bundles of ropey collagen resembling a spindle cell lipoma. This combination of a folliculosebaceous cystic hamartoma with a spindle cell lipoma-like mesenchymal proliferation is unusual and has not been previously reported. PMID:26588344

  12. Folliculosebaceous Cystic Hamartoma With Spindle Cell Lipoma-Like Stromal Features.

    PubMed

    Nguyen, Catherine M; Skupsky, Hadas; Cassarino, David

    2015-12-01

    Folliculosebaceous cystic hamartoma is a distinctive cutaneous hamartoma composed of follicular, sebaceous, and mesenchymal components. The lesions are most commonly found on the face and scalp of young adults, with approximately 30% occurring in the nasal or paranasal regions of the face. The clinical differential diagnoses are extensive and include epidermoid cyst, dermal nevus, soft fibroma, and adnexal tumors including sebaceous neoplasms. Here, the authors present a case of a 24-year-old man who presented for evaluation of an asymptomatic growth on the nose, which had slowly enlarged over 9 years. On examination, there was a 0.6 cm dome-shaped flesh-colored papule on the nasal bridge. The clinical differential included dermatofibroma versus intradermal nevus. A shave biopsy was performed, and histological examination of the sections showed a proliferation of multiple enlarged and irregular-appearing sebaceous glands attached to a cystic follicular structure. The associated dermal mesenchymal component consisted of numerous mature-appearing adipocytes associated with a fibromyxoid stroma, prominent collections of mucin, and bundles of ropey collagen resembling a spindle cell lipoma. This combination of a folliculosebaceous cystic hamartoma with a spindle cell lipoma-like mesenchymal proliferation is unusual and has not been previously reported.

  13. Atypical lipomatous tumor of the lip with pleomorphic lipoma-like myxoid area, clinically simulating mucocele.

    PubMed

    Hattori, Hideo

    2002-10-01

    Lipomatous tumor is least common in the oral cavity. We present a case of atypical lipomatous tumor arising in the lower lip of an 81-year-old male. Clinical diagnosis was mucocele. The tumor measured 12 mm in diameter with a round shape. It was solid, firm, myxomatous and translucent with a small yellowish focus in the central portion. Histologically, the tumor was a circumscribed and well-encapsulated mass with prominent myxoid matrix. The central minor portion showed a well-differentiated liposarcoma. In the myxoid area, lipoblasts and large atypical cells with dense chromatin including floret-like giant cells were seen in abundance. Atypical lipomatous tumor may be indistinguishable from pleomorphic lipoma and its distinction from the latter is based on location as well as relative abundance of floret-type giant cells and lipoblasts. According to its abundance in lipoblasts over floret-like cells, pleomorphic lipoma-like area in our case could also be a part of atypical lipomatous tumor. It may be possible to interpret myxoid change in our case as to represent a superficial counterpart of myxoid malignant fibrous histiocytoma-like change reported in the retroperitoneal lesion. PMID:12269996

  14. Atypical lipomatous tumor of the lip with pleomorphic lipoma-like myxoid area, clinically simulating mucocele.

    PubMed

    Hattori, Hideo

    2002-10-01

    Lipomatous tumor is least common in the oral cavity. We present a case of atypical lipomatous tumor arising in the lower lip of an 81-year-old male. Clinical diagnosis was mucocele. The tumor measured 12 mm in diameter with a round shape. It was solid, firm, myxomatous and translucent with a small yellowish focus in the central portion. Histologically, the tumor was a circumscribed and well-encapsulated mass with prominent myxoid matrix. The central minor portion showed a well-differentiated liposarcoma. In the myxoid area, lipoblasts and large atypical cells with dense chromatin including floret-like giant cells were seen in abundance. Atypical lipomatous tumor may be indistinguishable from pleomorphic lipoma and its distinction from the latter is based on location as well as relative abundance of floret-type giant cells and lipoblasts. According to its abundance in lipoblasts over floret-like cells, pleomorphic lipoma-like area in our case could also be a part of atypical lipomatous tumor. It may be possible to interpret myxoid change in our case as to represent a superficial counterpart of myxoid malignant fibrous histiocytoma-like change reported in the retroperitoneal lesion.

  15. Giant congenital melanocytic nevus (bathing trunk nevus) associated with lipoma and neurofibroma: report of two cases.

    PubMed

    Bhagwat, P V; Tophakhane, R S; Shashikumar, B M; Noronha, Tonita M; Naidu, Varna

    2009-01-01

    Giant congenital melanocytic nevi are rare and occur in about one out of every 2,00,000 to 5,00,000 births. There is a significant association between bathing trunk nevus and neurofibromatosis and lipomatosis. Apart from this, association of bathing trunk nevus with abnormalities like spina bifida occulta, meningocele, club foot and hypertrophy or atrophy of deeper structures of a limb, have been described. We are herewith reporting two cases of bathing trunk nevi. In our first case, an eight-year-old girl presented with a bathing trunk nevus studded with multiple, large nodules. Histopathological examination of the biopsy taken from one nodule revealed features of both neurofibroma and lipoma. To the best of our knowledge, features of both these hamartomas in one nodule of a single patient are probably not reported in the literature. In our second case, a 12-year-old girl presented with bathing trunk nevus and she had spina bifida occulta. She also had lipoma in the lesion of bathing trunk nevus. Both of our patients had satellite melanocytic nevi over the face, forearm, upper back and legs. Our second patient, in addition, had small melanocytic nevi over the medial canthus and sclerocorneal junction of the right eye. By the time this girl presented to us, the melanocytic nevus started fading in color and it had become brownish. We are reporting these cases for their peculiarities and for their rare features. PMID:19736430

  16. [Bilateral cerebellopontine arachnoid cyst].

    PubMed

    Gelabert-Gonzalez, M; Aran-Echabe, E; Pita-Buezas, L

    2016-06-16

    Introduccion. Los quistes aracnoideos bilaterales del angulo pontocerebeloso son excepcionales, y unicamente existen tres casos publicados en la bibliografia. Caso clinico. Niña de 14 años, previamente sana, que acude a consultas por presentar cefalea bifrontal de seis semanas de evolucion. La exploracion clinica era normal y la resonancia magnetica craneal mostraba dos lesiones extraaxiales localizadas en ambos angulos pontocerebelosos, siendo ligeramente mayor la izquierda. Las lesiones se comportaban como homogeneamente intensas en T1 e hiperintensas en T2, no captaban contraste y no existia restriccion en las secuencias de difusion. No se indico tratamiento quirurgico. Conclusiones. Los quistes aracnoideos bilaterales situados en el angulo pontocerebeloso son excepcionales. La principal indicacion para el tratamiento quirurgico es la presencia de sintomas o signos neurologicos coincidentes con la localizacion de los quistes.

  17. Spontaneous improvement in urological dysfunction in children with congenital spinal lipomas of the conus medullaris.

    PubMed

    Badhiwala, Jetan H; Thompson, Eric M; Lorenzo, Armando J; Kulkarni, Abhaya V

    2014-05-01

    Congenital spinal lipomas of the conus (SLCs) are among the most common closed neural tube defects. The treatment of SLC is an area of controversy because the true natural history of this condition is unknown. Here, the authors present two cases of SLC presenting in infancy with compromised lower urinary tract function, which was objectively confirmed by abnormal urodynamic studies. In both cases, there was spontaneous improvement in urodynamic parameters, with stable normal urinary function at the long-term follow-up. Although cases of spontaneous radiological regression of SLC have very infrequently been reported, they have not been associated with the reversal of already present neurological deficits. This report reinforces the need for further delineation of the true natural history of SLC and highlights the dynamic nature of associated neurological compromise over time.

  18. Case report of an oral fibroma occurring in a patient with familial multiple lipomas.

    PubMed

    Radfar, Lida; Holt, Tyler; Masood, Farah

    2013-12-01

    A wide variety of lesions may manifest in the oral soft tissues that could be confusing and challenging for the clinicians. These lesions could be as simple as trauma-induced ulcers that need about 2 weeks to heal, to a more complicated situation such as oral cancer. The key points in developing diagnosis and a possible treatment plan may include a comprehensive oral examination, simple understanding of normal oral tissue features, and knowledge of common oral lesions. This will help in the development of a differential diagnosis of the oral lesions/masses based on the risk factors in that particular patient. In this case report, we present a simple oral mass in a patient who had an oral fibroma and lipomas in other areas. PMID:24600803

  19. Neurofibroma and lipoma in association with giant congenital melanocytic nevus coexisting in one nodule: a case report.

    PubMed

    Shang, Zhiwei; Dai, Tao; Ren, Yongqiang

    2015-01-01

    Giant congenital melanocytic nevi (GCMN) are rare conditions that defined as melanocytic lesion recognized at birth, which will reach a diameter larger than 20 cm, and they occur in about 1 per 500,000 newborns. Despite its rarity, they may associate with severe abnormalities like spina bifida occulta, meningocele, club foot and hypertrophy or atrophy of deeper structures of a limb, Carney complex, premature aging syndromes, neurofibroma, vitiligo, lipoma and dysplasia of bilateral hip impact on the patient. In this case, we report a 3-years-old male child presenting a GCMN with large, blackish, and thick nevus covering over the entire neck, back, and lower to the waist level. We highlight the importance of proper histopathological examination of the biopsy taken from the single huge nodule which revealed features of both neurofibroma and lipoma coexisting. The objective of this paper is to report a rare case with the clinical and pathologic findings. PMID:26379904

  20. Angle detector

    NASA Technical Reports Server (NTRS)

    Parra, G. T. (Inventor)

    1978-01-01

    An angle detector for determining a transducer's angular disposition to a capacitive pickup element is described. The transducer comprises a pendulum mounted inductive element moving past the capacitive pickup element. The capacitive pickup element divides the inductive element into two parts L sub 1 and L sub 2 which form the arms of one side of an a-c bridge. Two networks R sub 1 and R sub 2 having a plurality of binary weighted resistors and an equal number of digitally controlled switches for removing resistors from the networks form the arms of the other side of the a-c bridge. A binary counter, controlled by a phase detector, balances the bridge by adjusting the resistance of R sub 1 and R sub 2. The binary output of the counter is representative of the angle.

  1. Identification of PPAP2B as a novel recurrent translocation partner gene of HMGA2 in lipomas.

    PubMed

    Bianchini, Laurence; Birtwisle, Loïc; Saâda, Esma; Bazin, Audrey; Long, Elodie; Roussel, Jean-François; Michiels, Jean-François; Forest, Fabien; Dani, Christian; Myklebost, Ola; Birtwisle-Peyrottes, Isabelle; Pedeutour, Florence

    2013-06-01

    Most lipomas are characterized by translocations involving the HMGA2 gene in 12q14.3. These rearrangements lead to the fusion of HMGA2 with an ectopic sequence from the translocation chromosome partner. Only five fusion partners of HMGA2 have been identified in lipomas so far. The identification of novel fusion partners of HMGA2 is important not only for diagnosis in soft tissue tumors but also because these genes might have an oncogenic role in other tumors. We observed that t(1;12)(p32;q14) was the second most frequent translocation in our series of lipomas after t(3;12)(q28;q14.3). We detected overexpression of HMGA2 mRNA and protein in all t(1;12)(p32;q14) lipomas. We used a fluorescence in situ hybridization-based positional cloning strategy to characterize the 1p32 breakpoint. In 11 cases, we identified PPAP2B, a member of the lipid phosphate phosphatases family as the 1p32 target gene. Reverse transcription-polymerase chain reaction analysis followed by nucleotide sequencing of the fusion transcript indicated that HMGA2 3' untranslated region (3'UTR) fused with exon 6 of PPAP2B in one case. In other t(1;12) cases, the breakpoint was extragenic, located in the 3'region flanking PPAP2B 3'UTR. Moreover, in one case showing a t(1;6)(p32;p21) we observed a rearrangement of PPAP2B and HMGA1, which suggests that HMGA1 might also be a fusion partner for PPAP2B. Our results also revealed that adipocytic differentiation of human mesenchymal stem cells derived from adipose tissue was associated with a significant decrease in PPAP2B mRNA expression suggesting that PPAP2B might play a role in adipogenesis.

  2. Solitary fibrous tumor: is there a molecular relationship with cellular angiofibroma, spindle cell lipoma, and mammary-type myofibroblastoma?

    PubMed

    Fritchie, Karen J; Carver, Paula; Sun, Yang; Batiouchko, Galina; Billings, Steven D; Rubin, Brian P; Tubbs, Raymond R; Goldblum, John R

    2012-06-01

    Solitary fibrous tumor (SFT) is a mesenchymal tumor characterized by ovoid cells, branching blood vessels, stromal hyalinization, and CD34 immunoreactivity. Studies have shown loss of 13q in a group of morphologically similar entities, including cellular angiofibroma, mammary-type myofibroblastoma, and spindle cell lipoma. The histologic and immunophenotypic overlap between SFT and the latter group of tumors suggests that these tumors may be genetically linked. We tested a group of 40 SFTs to assess for loss of RB1 (13q14) by fluorescence in situ hybridization (FISH). All 38 SFTs with evaluable signals failed to show loss of RB1 (13q14) by FISH. All cases of cellular angiofibroma (1/1), spindle cell lipoma (6/6), and mammary-type myofibroblastoma (4/4), which were used as a control group, showed monoallelic or biallelic loss of RB1. The absence of RB1 loss in SFTs suggests that they are not related to cellular angiofibroma, mammary-type myofibroblastoma, or spindle cell lipoma.

  3. Diagnostic and surgical challenges in resection of cerebellar angle tumors and acoustic neuromas

    PubMed Central

    Patel, Neal; Wilkinson, Jared; Gianaris, Nicholas; Cohen-Gadol, Aaron A.

    2012-01-01

    Background: Cerebellopontine angle (CPA) lesions can mimic more common tumors through nonspecific symptoms and radiologic findings. Methods: To increase the preoperative diagnostic accuracy for CPA pathologies, the authors review the full spectrum of reported CPA lesions. Results: A wide spectrum of lesions mimics vestibular schwannoma (VS) in the space of the CPA. Conclusion: The presence of any suspicious clinical and radiographic finding uncharacteristic of VS makes it necessary to maintain a broad differential diagnosis list. Differentiation of CPA lesions, although challenging, may be best achieved by incorporating the clinical history, physical exam findings, audiometry results, and multi-modality imaging studies to construct a comprehensive preoperative knowledge of the lesion. This knowledge will allow improved operative execution and outcomes. PMID:22439108

  4. Grynfeltt Hernia: A Deceptive Lumbar Mass with a Lipoma-Like Presentation.

    PubMed

    Zadeh, Jonathan R; Buicko, Jessica L; Patel, Chetan; Kozol, Robert; Lopez-Viego, Miguel A

    2015-01-01

    The Grynfeltt-Lesshaft hernia is a rare posterior abdominal wall defect that allows for the herniation of retro- and intraperitoneal structures through the upper lumbar triangle. While this hernia may initially present as a small asymptomatic bulge, the defect typically enlarges over time and can become symptomatic with potentially serious complications. In order to avoid that outcome, it is advisable to electively repair Grynfeltt hernias in patients without significant contraindications to surgery. Due to the limited number of lumbar hernioplasties performed, there has not been a large study that definitively identifies the best repair technique. It is generally accepted that abdominal hernias such as these should be repaired by tension-free methods. Both laparoscopic and open techniques are described in modern literature with unique advantages and complications for each. We present the case of an unexpected Grynfeltt hernia diagnosed following an attempted lipoma resection. We chose to perform an open repair involving a combination of fascial approximation and dual-layer polypropylene mesh placement. The patient's recovery was uneventful and there has been no evidence of recurrence at over six months. Our goal herein is to increase awareness of upper lumbar hernias and to discuss approaches to their surgical management. PMID:26697256

  5. Grynfeltt Hernia: A Deceptive Lumbar Mass with a Lipoma-Like Presentation

    PubMed Central

    Zadeh, Jonathan R.; Buicko, Jessica L.; Patel, Chetan; Kozol, Robert; Lopez-Viego, Miguel A.

    2015-01-01

    The Grynfeltt-Lesshaft hernia is a rare posterior abdominal wall defect that allows for the herniation of retro- and intraperitoneal structures through the upper lumbar triangle. While this hernia may initially present as a small asymptomatic bulge, the defect typically enlarges over time and can become symptomatic with potentially serious complications. In order to avoid that outcome, it is advisable to electively repair Grynfeltt hernias in patients without significant contraindications to surgery. Due to the limited number of lumbar hernioplasties performed, there has not been a large study that definitively identifies the best repair technique. It is generally accepted that abdominal hernias such as these should be repaired by tension-free methods. Both laparoscopic and open techniques are described in modern literature with unique advantages and complications for each. We present the case of an unexpected Grynfeltt hernia diagnosed following an attempted lipoma resection. We chose to perform an open repair involving a combination of fascial approximation and dual-layer polypropylene mesh placement. The patient's recovery was uneventful and there has been no evidence of recurrence at over six months. Our goal herein is to increase awareness of upper lumbar hernias and to discuss approaches to their surgical management. PMID:26697256

  6. [Wide resection of chest wall for intramuscular lipoma in serratus anterior muscle reconstructed by autologous tissue;report of a case].

    PubMed

    Mizuno, Kiyomichi; Urabe, Norikazu; Nakatsuka, Kazuhiko; Ishikawa, Kayoko; Eguchi, Masanobu

    2015-02-01

    A 60-years-old man with a right lateral chest wall mass visited our hospital. There was a mass of 50×45 mm on the 5th rib. The mild atypical cells were detected by the percutaneous needle biopsy, and the tumor was resected with the chest wall of which detect was reconstructed with fascia lata and latissimus dorsi muscle cutaneous flap. Pathological diagnosis was lipoma in the serratus anterior muscle. The postoperative course was uneventful without paradoxical respiration and surgical site infection. Since intramuscular lipoma is very rare and is reported to have a risk of recurrence, careful observation is necessary.

  7. Cleft lip and palate, sensorineural deafness, and sacral lipoma in two brothers: a possible example of the disorganisation mutant.

    PubMed Central

    Lowry, R B; Yong, S L

    1991-01-01

    We report two brothers of Chinese origin who have an apparently unique syndrome of cleft lip/palate, profound sensorineural deafness, and a sacral lipoma. Additional findings which were not common to both were aberrant digital appendages on the heel and thigh of one boy and an anterior sacral meningocele and dislocated hip in the other. Intelligence is normal in both. Both boys suffer from functional constipation but biopsy studies showed no evidence of Hirschsprung's disease. The parents, who are normal, are not related. Inheritance is probably autosomal or X linked recessive. A possible link with the disorganisation mouse mutant is discussed. Images PMID:2002486

  8. Cutaneous CD34+ spindle cell neoplasms: Histopathologic features distinguish spindle cell lipoma, solitary fibrous tumor, and dermatofibrosarcoma protuberans.

    PubMed

    Wood, Lance; Fountaine, Thomas J; Rosamilia, Lorraine; Helm, Klaus F; Clarke, Loren E

    2010-12-01

    Spindle cell lipoma (SCL), dermatofibrosarcoma protuberans (DFSP), and solitary fibrous tumors (SFT) are cutaneous CD34+ spindle cell tumors that may exhibit histopathologic and immunophenotypic overlap. We sought ways to reliably distinguish among these lesions even in small or superficial biopsies. Ten morphologic characteristics were analyzed in a group of 5 SCLs, 6 cutaneous SFTs, and 12 DFSPs. SFT and DFSP exhibited extensive histopathologic overlap in small or partial biopsies. However, adnexal entrapment, defined as diffuse proliferation of tumor cells around pilosebaceous and eccrine structures with minimal disruption or expansion of the dermis, was a feature seen in 10 of the 12 DFSPs and in none of the SFTs or SCLs. Even when only superficial portions of a lesion were present, this feature was identifiable. Spindle cell lipomas posed little diagnostic difficulty, in part because excisional biopsies were performed in all cases of SCL. The number of samples included in the study is relatively small, in part due to the rarity of cutaneous solitary fibrous tumors. We conclude that careful attention to these histopathologic features enables reliable distinction among these tumors.

  9. The expression of MDM2/CDK4 gene product in the differential diagnosis of well differentiated liposarcoma and large deep-seated lipoma

    PubMed Central

    Pilotti, S; Torre, G Della; Mezzelani, A; Tamborini, E; Azzarelli, A; Sozzi, G; Pierotti, M A

    2000-01-01

    Ordinary lipomas are cytogenetically characterized by a variety of balanced rearrangements involving chromosome segment 12q13–15, whereas well differentiated liposarcomas (WDL) show supernumerary ring and giant marker chromosomes, known to contain amplified 12q sequences. The tight correlation between the presence of ring chromosomes and both amplification and overexpression of MDM2 and CDK4 genes suggests the exploration of the possibility that immunocytochemistry (ICC) might assist in the differential diagnosis of lipoma-like well differentiated liposarcomas (LL-WDL) and large deep-seated lipomas (LDSL). For this purpose, 21 cases of the former and 19 cases of the latter tumours were analysed by ICC and, according to the availability of material, by molecular and cytogenetic approaches. All lipomas displayed a null MDM2/CDK4 phenotype, whereas all LL-WDL showed MDM2/CDK4 or CDK4 phenotypes. Southern blot analysis performed on 16 suitable cases, complemented by fluorescence in situ hybridization and classical cytogenetic analysis in 11 cases, was consistent with, and further supported the immunophenotyping data. In conclusion, MDM2/CDK4 product-based immunophenotyping appears to represent a valuable method for the categorization of arguable LDSL. © 2000 Cancer Research Campaign PMID:10755400

  10. Three dosimetry models of lipoma arborescens treated by {sup 90}Y synovectomy

    SciTech Connect

    O’Doherty, Jim; Clauss, Ralf; Scuffham, James; Khan, Aman; Petitguillaume, Alice; Desbrée, Aurélie

    2014-05-15

    Purpose: Lipoma arborescens (LA) is a benign intra-articular lipomatous proliferation of the synovial membrane. This extremely rare condition has previously been treated by intra-articular{sup 90}Y radiosynoviorthesis but dosimetry literature on this form of radionuclide therapy is nonexistent. The authors detail methodology for successful treatment of LA and provide for the first time estimates of radiation dosimetry. The authors also analyze the biodistribution of the radiopharmaceutical over the course of the patient's treatment through sequential imaging. Methods: A patient with bilateral LA underwent intracavity injection of{sup 90}Y citrate colloid to the right and left knee joint spaces (181 and 198 MBq, respectively). SPECT/CT datasets were acquired over 9 days to quantify the biodistribution and kinetics of the radiopharmaceutical. Radiation dosimetry was performed using the MIRD schema (through OLINDA software), a custom voxel-based method, and a direct Monte Carlo calculation (OEDIPE). Results: Follow-up MRI showed marked reduction in LA size in both knees. Mean absorbed doses to the LA were 21.2 ± 0.8 and 42.9 ± 2.3 Gy using OLINDA, 8.1 ± 0.3 and 16.7 ± 0.5 Gy using voxel based methodology, and 8.2 ± 0.3 and 15.7 ± 0.5 Gy for OEDIPE in the right and left LA, respectively. Distribution of the radiopharmaceutical within the joint space alters over the imaging period, with less than 1% of the remaining activity having moved posteriorly in the knee cavity. No uptake was detected outside of the joint space after assessment with whole-body scintigraphy. Conclusions: An activity of approximately 185 MBq successfully relieved clinical symptoms of LA. There was good correlation between direct Monte Carlo and voxel based techniques, but OLINDA was shown to overestimate the absorbed dose to the tumor. Accurate dosimetry may help select an activity more tailored to the specific size and location of the LA.

  11. Auditory Hallucinosis as a Presenting Feature of Interpeduncular Lipoma with Proximal P1 Segment Fenestration: Report of a Rare Case and Review of Literature on Peduncular Hallucinosis

    PubMed Central

    Kulhari, Ashish; Manjila, Sunil; Singh, Gagandeep; Kumar, Kunal; Tarr, Robert W; Bambakidis, Nicholas

    2016-01-01

    The authors present a unique case of intracranial lipoma in the interpeduncular cistern associated with proximal P1 segment fenestration. This patient is a 20-year-old male with extensive psychiatric history and complaints of recent auditory hallucinations. Cranial magnetic resonance imaging (MRI) (T1, T2, and FLAIR) showed a hyperintense lesion in the left aspect of interpeduncular cistern with a prominent flow void within the hyperintense lesion suggestive of a combined vascular–lipomatous lesion. Computed tomography (CT) angiography showed a high-riding large tortuous P1 segment on the left side with proximal fenestration, the ectatic posteromedial limb harboring a fusiform dilated segment. Since there are anecdotal cases of cerebral aneurysms associated with intracranial lipomas, a conventional angiography was done, which confirmed a proximal left P1 fenestration and a fusiform-dilated segment, and no aneurysm. There are few cases of hallucinations associated with a vascular midbrain pathology reported in literature, but hallucinations associated with a combination of lipoma and arterial ectasia have never been reported. This article not only demonstrates the MRI and angiographic appearance of this rare lipomatous lesion but also highlights this unique association and significance of auditory hallucinations as a clinical presentation, akin to peduncular hallucinosis. PMID:27403217

  12. Myofibroblastoma of the breast with hemangiopericytoma-like pattern and pleomorphic lipoma-like areas. Report of a case with diagnostic and histogenetic considerations.

    PubMed

    Magro, G; Fraggetta, F; Torrisi, A; Emmanuele, C; Lanzafame, S

    1999-01-01

    Myofibroblastoma (MFB) of the breast is an uncommon benign spindle cell tumor which may exhibit a wide spectrum of histological features. We report an unusual case of MFB of the male breast, showing cellular areas with a hemangiopericytoma-like pattern similar to that observed in solitary fibrous tumor (SFT) and extensive fibromyxoid areas containing numerous atypical stromal cells. The association of these atypical cells with mature adipocytes and microcystic and/or myxoid degenerative changes resembled pleomorphic lipoma-like and myxoid liposarcoma-like features, respectively. To our knowledge, these peculiar morphological findings have not been previously reported in MFB of the breast. They should be recognized to avoid confusion with other mesenchymal tumors, especially with hemangiopericytoma, pleomorphic lipoma (PL), spindle-cell lipoma (SCL) and myxoid liposarcoma. A case of MFB of the breast showing morphological features also commonly seen in SFT and PL/SCL is further morphological evidence in support of the speculation that the mesenchymal tumors of the breast, also known under the terms benign spindle cell tumors, fibromas, SFTs, SCLs and MFBs, are histogenetically related lesions.

  13. An unusual and spectacular case of spindle cell lipoma of the posterior neck invading the spinal cervical canal and posterior cranial fossa.

    PubMed

    Petit, Damien; Menei, Philippe; Fournier, Henri-Dominique

    2011-11-01

    The authors describe the first case of spindle cell lipoma of the posterior neck invading the upper cervical spinal canal and the posterior cranial fossa. Spindle cell lipoma is an extremely rare variant of benign lipoma. It usually occurs as a solitary subcutaneous well-circumscribed lesion in the posterior neck or shoulders of adult men. Local aggressiveness is unusual. This 61-year-old man presented with an increased left cerebellar syndrome and headaches. He also had a posterior neck tumefaction, which had been known about for a long time. Computed tomography and MR imaging studies revealed a voluminous mass extending to the upper cervical canal and posterior cranial fossa and eroding the neighboring bones. The lesion was well delimited, and contrast enhancement was intense and heterogeneous. The tumor, which had initially developed under the muscles of the posterior neck, was totally resected. Histological assessment revealed numerous fat cells with spindle cells secreting collagen. The large size of the tumor and the submuscular location, bone erosion, and compression of the CNS were unusual in this rare subtype of benign adipose tumor. Its presentation could simulate a sarcoma.

  14. Perception of Perspective Angles.

    PubMed

    Erkelens, Casper J

    2015-06-01

    We perceive perspective angles, that is, angles that have an orientation in depth, differently from what they are in physical space. Extreme examples are angles between rails of a railway line or between lane dividers of a long and straight road. In this study, subjects judged perspective angles between bars lying on the floor of the laboratory. Perspective angles were also estimated from pictures taken from the same point of view. Converging and diverging angles were judged to test three models of visual space. Four subjects evaluated the perspective angles by matching them to nonperspective angles, that is, angles between the legs of a compass oriented in the frontal plane. All subjects judged both converging and diverging angles larger than the physical angle and smaller than the angles in the proximal stimuli. A model of shallow visual space describes the results. According to the model, lines parallel to visual lines, vanishing at infinity in physical space, converge to visual lines in visual space. The perceived shape of perspective angles is incompatible with the perceived length and width of the bars. The results have significance for models of visual perception and practical implications for driving and flying in poor visibility conditions. PMID:27433312

  15. Reading Angles in Maps

    ERIC Educational Resources Information Center

    Izard, Véronique; O'Donnell, Evan; Spelke, Elizabeth S.

    2014-01-01

    Preschool children can navigate by simple geometric maps of the environment, but the nature of the geometric relations they use in map reading remains unclear. Here, children were tested specifically on their sensitivity to angle. Forty-eight children (age 47:15-53:30 months) were presented with fragments of geometric maps, in which angle sections…

  16. Rb1 and Pten Co-Deletion in Osteoblast Precursor Cells Causes Rapid Lipoma Formation in Mice

    PubMed Central

    Filtz, Emma A.; Emery, Ann; Lu, Huarui; Forster, Colleen L.; Karasch, Chris; Hallstrom, Timothy C.

    2015-01-01

    The Rb and Pten tumor suppressor genes are important regulators of bone development and both are frequently mutated in the bone cancer osteosarcoma (OS). To determine if Rb1 and Pten synergize as tumor suppressor genes for osteosarcoma, we co-deleted them in osteoprogenitor cells. Surprisingly, we observed rapid development of adipogenic but not osteosarcoma tumors in the ΔRb1/Pten mice. ΔPten solo deleted mice also developed lipoma tumors but at a much reduced frequency and later onset than those co-deleted for Rb1. Pten deletion also led to a marked increase in adipocytes in the bone marrow. To better understand the function of Pten in bone development in vivo, we conditionally deleted Pten in OSX+ osteoprogenitor cells using OSX-Cre mice. μCT analysis revealed a significant thickening of the calvaria and an increase in trabeculae volume and number in the femur, consistent with increased bone formation in these mice. To determine if Pten and Rb1 deletion actively promotes adipogenic differentiation, we isolated calvarial cells from Ptenfl/fl and Ptenfl/fl; Rb1fl/fl mice, infected them with CRE or GFP expressing adenovirus, treated with differentiation media. We observed slightly increased adipogenic, and osteogenic differentiation in the ΔPten cells. Both phenotypes were greatly increased upon Rb1/Pten co-deletion. This was accompanied by an increase in expression of genes required for adipogenesis. These data indicate that Pten deletion in osteoblast precursors is sufficient to promote frequent adipogenic, but only rare osteogenic tumors. Rb1 hetero- or homo-zygous co-deletion greatly increases the incidence and the rapidity of onset of adipogenic tumors, again, with only rare osteosarcoma tumors. PMID:26317218

  17. Angles, Time, and Proportion

    ERIC Educational Resources Information Center

    Pagni, David L.

    2005-01-01

    This article describes an investigation making connections between the time on an analog clock and the angle between the minute hand and the hour hand. It was posed by a middle school mathematics teacher. (Contains 8 tables and 6 figures.)

  18. Reading angles in maps.

    PubMed

    Izard, Véronique; O'Donnell, Evan; Spelke, Elizabeth S

    2014-01-01

    Preschool children can navigate by simple geometric maps of the environment, but the nature of the geometric relations they use in map reading remains unclear. Here, children were tested specifically on their sensitivity to angle. Forty-eight children (age 47:15-53:30 months) were presented with fragments of geometric maps, in which angle sections appeared without any relevant length or distance information. Children were able to read these map fragments and compare two-dimensional to three-dimensional angles. However, this ability appeared both variable and fragile among the youngest children of the sample. These findings suggest that 4-year-old children begin to form an abstract concept of angle that applies both to two-dimensional and three-dimensional displays and that serves to interpret novel spatial symbols. PMID:23647223

  19. Morphometric analysis of posterior fossa in Indian CP angle acoustic schwannoma patients

    PubMed Central

    Patibandla, Mohana Rao; Panigrahi, Manas K.; Gurram, Paniraj L.; Thotakura, Amit Kumar; Kulkarni, Dilip

    2016-01-01

    Aim: To study the morphometry of posterior fossa in Indian CP angle schwannoma patients in order to know its influence on the extent of excision of the CP angle acoustic schwannomas. Materials and Methods: One hundred cases of cerebellopontine angle schwannomas treated surgically by the senior author and 20 controls between January 2006 and June 2011 were consecutively investigated with computed tomography (CT) using the high-resolution CT bone windows before surgery. Evaluation of anatomic parameters of the petrous bone and posterior fossa cavity were done in all patients and controls. Data were entered in Excel software and were analyzed using NCSS software. All possible regression analysis was done to select the important variables to be included in the model to predict the excision of tumor with these variables. A prediction model was developed defining the binary outcome as total excision or subtotal excision as dependent variable and the morphometric data and grading of tumor as independent variables. Results: Interpetrous distance (IP) is the distance between the two petrous apices. Sigmoid distance (IS) distance is the distance between the two sigmoid points. Sigmoid point is the point at which the scalloped impression of the sigmoid sinus straightens to join the occipital bone posteriorly. SAG is the distance between the mid IP point and the mid-point on the inner wall of the occipital bone. The PM angle was 47.8±4.14 degrees (38-58), the PA angle was 42.68±4.47 degrees (34-53), the IP distance was 2.07±0.13 cm (1.5-2.8), the sagittal diameter of posterior fossa was 6.22±0.73 cm (5.1-9.8) and the intersigmoid distance was 9.45±0.73 cm (7.4-11). There was no significant gender difference in the posterior fossa morphometry between patients and controls. Inter-sigmoid distance and the petrous-apex angle were more in the Indians when compared to the European population mentioned in the Mathies and Samii study. Conclusions: The posterior fossa

  20. 'Magic Angle Precession'

    SciTech Connect

    Binder, Bernd

    2008-01-21

    An advanced and exact geometric description of nonlinear precession dynamics modeling very accurately natural and artificial couplings showing Lorentz symmetry is derived. In the linear description it is usually ignored that the geometric phase of relativistic motion couples back to the orbital motion providing for a non-linear recursive precession dynamics. The high coupling strength in the nonlinear case is found to be a gravitomagnetic charge proportional to the precession angle and angular velocity generated by geometric phases, which are induced by high-speed relativistic rotations and are relevant to propulsion technologies but also to basic interactions. In the quantum range some magic precession angles indicating strong coupling in a phase-locked chaotic system are identified, emerging from a discrete time dynamical system known as the cosine map showing bifurcations at special precession angles relevant to heavy nuclei stability. The 'Magic Angle Precession' (MAP) dynamics can be simulated and visualized by cones rolling in or on each other, where the apex and precession angles are indexed by spin, charge or precession quantum numbers, and corresponding magic angles. The most extreme relativistic warping and twisting effect is given by the Dirac spinor half spin constellation with 'Hyperdiamond' MAP, which resembles quark confinement.

  1. Casting and Angling.

    ERIC Educational Resources Information Center

    Smith, Julian W.

    As part of a series of books and pamphlets on outdoor education, this manual consists of easy-to-follow instructions for fishing activities dealing with casting and angling. The manual may be used as a part of the regular physical education program in schools and colleges or as a club activity for the accomplished weekend fisherman or the…

  2. An Iterative Angle Trisection

    ERIC Educational Resources Information Center

    Muench, Donald L.

    2007-01-01

    The problem of angle trisection continues to fascinate people even though it has long been known that it can't be done with straightedge and compass alone. However, for practical purposes, a good iterative procedure can get you as close as you want. In this note, we present such a procedure. Using only straightedge and compass, our procedure…

  3. Interferometric measurement of angles.

    PubMed

    Malacara, D; Harris, O

    1970-07-01

    A new interferometric device for measuring small angles or rotations with high accuracy is described. This instrument works by counting fringes formed by the rotation of a flat-parallel plate of glass illuminated with a collimated beam from a gas laser. Some possible applications are given.

  4. A Different Angle on Perspective

    ERIC Educational Resources Information Center

    Frantz, Marc

    2012-01-01

    When a plane figure is photographed from different viewpoints, lengths and angles appear distorted. Hence it is often assumed that lengths, angles, protractors, and compasses have no place in projective geometry. Here we describe a sense in which certain angles are preserved by projective transformations. These angles can be constructed with…

  5. Angle Sense: A Valuable Connector.

    ERIC Educational Resources Information Center

    Rubenstein, Rheta N.; And Others

    1993-01-01

    Proposes angle sense as a fundamental connector between mathematical concepts for middle grade students. Introduces the use of pattern blocks and a goniometer, a tool to measure angles, to help students develop angle sense. Discusses connections between angle measurement and the concepts of rational numbers, circles, area, number theory,…

  6. Angles in the Sky?

    NASA Astrophysics Data System (ADS)

    Behr, Bradford

    2005-09-01

    Tycho Brahe lived and worked in the late 1500s before the telescope was invented. He made highly accurate observations of the positions of planets, stars, and comets using large angle-measuring devices of his own design. You can use his techniques to observe the sky as well. For example, the degree, a common unit of measurement in astronomy, can be measured by holding your fist at arm's length up to the sky. Open your fist and observe the distance across the sky covered by the width of your pinky fingernail. That is, roughly, a degree! After some practice, and knowing that one degree equals four minutes, you can measure elapsed time by measuring the angle of the distance that the Moon appears to have moved and multiplying that number by four. You can also figure distances and sizes of things. These are not precise measurements, but rough estimates that can give you a "close-enough" answer.

  7. Laser angle sensor

    NASA Technical Reports Server (NTRS)

    Pond, C. R.; Texeira, P. D.

    1985-01-01

    A laser angle measurement system was designed and fabricated for NASA Langley Research Center. The instrument is a fringe counting interferometer that monitors the pitch attitude of a model in a wind tunnel. A laser source and detector are mounted above the model. Interference fringes are generated by a small passive element on the model. The fringe count is accumulated and displayed by a processor in the wind tunnel control room. This report includes optical and electrical schematics, system maintenance and operation procedures.

  8. Wide Angle Movie

    NASA Technical Reports Server (NTRS)

    1999-01-01

    This brief movie illustrates the passage of the Moon through the Saturn-bound Cassini spacecraft's wide-angle camera field of view as the spacecraft passed by the Moon on the way to its closest approach with Earth on August 17, 1999. From beginning to end of the sequence, 25 wide-angle images (with a spatial image scale of about 14 miles per pixel (about 23 kilometers)were taken over the course of 7 and 1/2 minutes through a series of narrow and broadband spectral filters and polarizers, ranging from the violet to the near-infrared regions of the spectrum, to calibrate the spectral response of the wide-angle camera. The exposure times range from 5 milliseconds to 1.5 seconds. Two of the exposures were smeared and have been discarded and replaced with nearby images to make a smooth movie sequence. All images were scaled so that the brightness of Crisium basin, the dark circular region in the upper right, is approximately the same in every image. The imaging data were processed and released by the Cassini Imaging Central Laboratory for Operations (CICLOPS)at the University of Arizona's Lunar and Planetary Laboratory, Tucson, AZ.

    Photo Credit: NASA/JPL/Cassini Imaging Team/University of Arizona

    Cassini, launched in 1997, is a joint mission of NASA, the European Space Agency and Italian Space Agency. The mission is managed by NASA's Jet Propulsion Laboratory, Pasadena, CA, for NASA's Office of Space Science, Washington DC. JPL is a division of the California Institute of Technology, Pasadena, CA.

  9. Glancing angle RF sheaths

    NASA Astrophysics Data System (ADS)

    D'Ippolito, D. A.; Myra, J. R.

    2013-10-01

    RF sheaths occur in tokamaks when ICRF waves encounter conducting boundaries. The sheath plays an important role in determining the efficiency of ICRF heating, the impurity influxes from the edge plasma, and the plasma-facing component damage. An important parameter in sheath theory is the angle θ between the equilibrium B field and the wall. Recent work with 1D and 2D sheath models has shown that the rapid variation of θ around a typical limiter can lead to enhanced sheath potentials and localized power deposition (hot spots) when the B field is near glancing incidence. The physics model used to obtain these results does not include some glancing-angle effects, e.g. possible modification of the angular dependence of the Child-Langmuir law and the role of the magnetic pre-sheath. Here, we report on calculations which explore these effects, with the goal of improving the fidelity of the rf sheath BC used in analytical and numerical calculations. Work supported by US DOE grants DE-FC02-05ER54823 and DE-FG02-97ER54392.

  10. Variable angle correlation spectroscopy

    SciTech Connect

    Lee, Y K

    1994-05-01

    In this dissertation, a novel nuclear magnetic resonance (NMR) technique, variable angle correlation spectroscopy (VACSY) is described and demonstrated with {sup 13}C nuclei in rapidly rotating samples. These experiments focus on one of the basic problems in solid state NMR: how to extract the wealth of information contained in the anisotropic component of the NMR signal while still maintaining spectral resolution. Analysis of the anisotropic spectral patterns from poly-crystalline systems reveal information concerning molecular structure and dynamics, yet in all but the simplest of systems, the overlap of spectral patterns from chemically distinct sites renders the spectral analysis difficult if not impossible. One solution to this problem is to perform multi-dimensional experiments where the high-resolution, isotropic spectrum in one dimension is correlated with the anisotropic spectral patterns in the other dimensions. The VACSY technique incorporates the angle between the spinner axis and the static magnetic field as an experimental parameter that may be incremented during the course of the experiment to help correlate the isotropic and anisotropic components of the spectrum. The two-dimensional version of the VACSY experiments is used to extract the chemical shift anisotropy tensor values from multi-site organic molecules, study molecular dynamics in the intermediate time regime, and to examine the ordering properties of partially oriented samples. The VACSY technique is then extended to three-dimensional experiments to study slow molecular reorientations in a multi-site polymer system.

  11. Delayed diagnosed intermuscular lipoma causing a posterior interosseous nerve palsy in a patient with cervical spondylosis: the “priceless” value of the clinical examination in the technological era

    PubMed Central

    COLASANTI, R.; IACOANGELI, M.; DI RIENZO, A.; DOBRAN, M.; DI SOMMA, L.; NOCCHI, N.; SCERRATI, M.

    2016-01-01

    Background Posterior interosseous nerve (PIN) palsy may present with various symptoms, and may resemble cervical spondylosis. Case report We report about a 59-year-old patient with cervical spondylosis which delayed the diagnosis of posterior interosseous nerve (PIN) palsy due to an intermuscular lipoma. Initial right hand paraesthesias and clumsiness, together with MR findings of right C5–C6 and C6–C7 foraminal stenosis, misled the diagnostic investigation. The progressive loss of extension of all right hand fingers brought to detect a painless mass compressing the PIN. Electrophysiological studies confirmed a right radial motor neuropathy at the level of the forearm. Results Surgical tumor removal and nerve decompression resulted in a gradual motor deficits recovery. Conclusions A thorough clinical examination is paramount, and electrophysiology may differentiate between cervical and peripheral nerve lesions. Ultrasonography and MR offer an effective evaluation of lipomas, which represent a rare cause of PIN palsy. Surgical decompression and lipoma removal generally determine excellent prognoses, with very few recurrences. PMID:27142825

  12. Heterodyne Interferometer Angle Metrology

    NASA Technical Reports Server (NTRS)

    Hahn, Inseob; Weilert, Mark A.; Wang, Xu; Goullioud, Renaud

    2010-01-01

    A compact, high-resolution angle measurement instrument has been developed that is based on a heterodyne interferometer. The common-path heterodyne interferometer metrology is used to measure displacements of a reflective target surface. In the interferometer setup, an optical mask is used to sample the measurement laser beam reflecting back from a target surface. Angular rotations, around two orthogonal axes in a plane perpendicular to the measurement- beam propagation direction, are determined simultaneously from the relative displacement measurement of the target surface. The device is used in a tracking telescope system where pitch and yaw measurements of a flat mirror were simultaneously performed with a sensitivity of 0.1 nrad, per second, and a measuring range of 0.15 mrad at a working distance of an order of a meter. The nonlinearity of the device is also measured less than one percent over the measurement range.

  13. Narrow Angle movie

    NASA Technical Reports Server (NTRS)

    1999-01-01

    This brief three-frame movie of the Moon was made from three Cassini narrow-angle images as the spacecraft passed by the Moon on the way to its closest approach with Earth on August 17, 1999. The purpose of this particular set of images was to calibrate the spectral response of the narrow-angle camera and to test its 'on-chip summing mode' data compression technique in flight. From left to right, they show the Moon in the green, blue and ultraviolet regions of the spectrum in 40, 60 and 80 millisecond exposures, respectively. All three images have been scaled so that the brightness of Crisium basin, the dark circular region in the upper right, is the same in each image. The spatial scale in the blue and ultraviolet images is 1.4 miles per pixel (2.3 kilometers). The original scale in the green image (which was captured in the usual manner and then reduced in size by 2x2 pixel summing within the camera system) was 2.8 miles per pixel (4.6 kilometers). It has been enlarged for display to the same scale as the other two. The imaging data were processed and released by the Cassini Imaging Central Laboratory for Operations (CICLOPS) at the University of Arizona's Lunar and Planetary Laboratory, Tucson, AZ.

    Photo Credit: NASA/JPL/Cassini Imaging Team/University of Arizona

    Cassini, launched in 1997, is a joint mission of NASA, the European Space Agency and Italian Space Agency. The mission is managed by NASA's Jet Propulsion Laboratory, Pasadena, CA, for NASA's Office of Space Science, Washington DC. JPL is a division of the California Institute of Technology, Pasadena, CA.

  14. Equilibrium contact angle or the most-stable contact angle?

    PubMed

    Montes Ruiz-Cabello, F J; Rodríguez-Valverde, M A; Cabrerizo-Vílchez, M A

    2014-04-01

    It is well-established that the equilibrium contact angle in a thermodynamic framework is an "unattainable" contact angle. Instead, the most-stable contact angle obtained from mechanical stimuli of the system is indeed experimentally accessible. Monitoring the susceptibility of a sessile drop to a mechanical stimulus enables to identify the most stable drop configuration within the practical range of contact angle hysteresis. Two different stimuli may be used with sessile drops: mechanical vibration and tilting. The most stable drop against vibration should reveal the changeless contact angle but against the gravity force, it should reveal the highest resistance to slide down. After the corresponding mechanical stimulus, once the excited drop configuration is examined, the focus will be on the contact angle of the initial drop configuration. This methodology needs to map significantly the static drop configurations with different stable contact angles. The most-stable contact angle, together with the advancing and receding contact angles, completes the description of physically realizable configurations of a solid-liquid system. Since the most-stable contact angle is energetically significant, it may be used in the Wenzel, Cassie or Cassie-Baxter equations accordingly or for the surface energy evaluation.

  15. Small angle neutron scattering

    NASA Astrophysics Data System (ADS)

    Cousin, Fabrice

    2015-10-01

    Small Angle Neutron Scattering (SANS) is a technique that enables to probe the 3-D structure of materials on a typical size range lying from ˜ 1 nm up to ˜ a few 100 nm, the obtained information being statistically averaged on a sample whose volume is ˜ 1 cm3. This very rich technique enables to make a full structural characterization of a given object of nanometric dimensions (radius of gyration, shape, volume or mass, fractal dimension, specific area…) through the determination of the form factor as well as the determination of the way objects are organized within in a continuous media, and therefore to describe interactions between them, through the determination of the structure factor. The specific properties of neutrons (possibility of tuning the scattering intensity by using the isotopic substitution, sensitivity to magnetism, negligible absorption, low energy of the incident neutrons) make it particularly interesting in the fields of soft matter, biophysics, magnetic materials and metallurgy. In particular, the contrast variation methods allow to extract some informations that cannot be obtained by any other experimental techniques. This course is divided in two parts. The first one is devoted to the description of the principle of SANS: basics (formalism, coherent scattering/incoherent scattering, notion of elementary scatterer), form factor analysis (I(q→0), Guinier regime, intermediate regime, Porod regime, polydisperse system), structure factor analysis (2nd Virial coefficient, integral equations, characterization of aggregates), and contrast variation methods (how to create contrast in an homogeneous system, matching in ternary systems, extrapolation to zero concentration, Zero Averaged Contrast). It is illustrated by some representative examples. The second one describes the experimental aspects of SANS to guide user in its future experiments: description of SANS spectrometer, resolution of the spectrometer, optimization of spectrometer

  16. [Angle-closure chronic glaucoma].

    PubMed

    Lachkar, Y

    2003-10-01

    The incidence of chronic angle closure glaucoma is considerably greater than the incidence of the acute type. This type of glaucoma may mimic primary open angle glaucoma with visual field deterioration, optic nerve alteration and intraocular pressure elevation with a quiet painless eye. Its diagnosis is based on indentation gonioscopy showing peripheral anterior synechiae. The mechanisms of angle closure are the pupillary block, the plateau iris configuration and the creeping form. The treatment of chronic angle closure glaucoma is based on laser peripheral iridotomy. PMID:14646832

  17. The Critical Angle Can Override the Brewster Angle

    ERIC Educational Resources Information Center

    Froehle, Peter H.

    2009-01-01

    As a culminating activity in their study of optics, my students investigate polarized light and the Brewster angle. In this exercise they encounter a situation in which it is impossible to measure the Brewster angle for light reflecting from a particular surface. This paper describes the activity and explains the students' observations.

  18. Measuring Angles in Physical Therapy.

    ERIC Educational Resources Information Center

    Greeley, Nansee; Offerman, Theresa Reardon

    1997-01-01

    Features articles about physical therapy and its history as related to geometry through measurement of body angles. Includes open-ended worksheets for mathematics activities that introduce students to angle measurement, data analysis, and mathematical tools. Activities include: (1) Making Your Own Goniometer; (2) Range of Motion; (3) Active versus…

  19. Spinning angle optical calibration apparatus

    DOEpatents

    Beer, Stephen K.; Pratt, II, Harold R.

    1991-01-01

    An optical calibration apparatus is provided for calibrating and reproducing spinning angles in cross-polarization, nuclear magnetic resonance spectroscopy. An illuminated magnifying apparatus enables optical setting an accurate reproducing of spinning "magic angles" in cross-polarization, nuclear magnetic resonance spectroscopy experiments. A reference mark scribed on an edge of a spinning angle test sample holder is illuminated by a light source and viewed through a magnifying scope. When the "magic angle" of a sample material used as a standard is attained by varying the angular position of the sample holder, the coordinate position of the reference mark relative to a graduation or graduations on a reticle in the magnifying scope is noted. Thereafter, the spinning "magic angle" of a test material having similar nuclear properties to the standard is attained by returning the sample holder back to the originally noted coordinate position.

  20. Spinning angle optical calibration apparatus

    SciTech Connect

    Beer, S.K.; Pratt, H.R. II.

    1989-09-12

    An optical calibration apparatus is provided for calibrating and reproducing spinning angles in cross-polarization, nuclear magnetic resonance spectroscopy. An illuminated magnifying apparatus enables optical setting and accurate reproducing of spinning magic angles in cross-polarization, nuclear magnetic resonance spectroscopy experiments. A reference mark scribed on an edge of a spinning angle test sample holder is illuminated by a light source and viewed through a magnifying scope. When the magic angle of a sample material used as a standard is attained by varying the angular position of the sample holder, the coordinate position of the reference mark relative to a graduation or graduations on a reticle in the magnifying scope is noted. Thereafter, the spinning magic angle of a test material having similar nuclear properties to the standard is attained by returning the sample holder back to the originally noted coordinate position. 2 figs.

  1. Hysteresis during contact angles measurement.

    PubMed

    Diaz, M Elena; Fuentes, Javier; Cerro, Ramon L; Savage, Michael D

    2010-03-15

    A theory, based on the presence of an adsorbed film in the vicinity of the triple contact line, provides a molecular interpretation of intrinsic hysteresis during the measurement of static contact angles. Static contact angles are measured by placing a sessile drop on top of a flat solid surface. If the solid surface has not been previously in contact with a vapor phase saturated with the molecules of the liquid phase, the solid surface is free of adsorbed liquid molecules. In the absence of an adsorbed film, molecular forces configure an advancing contact angle larger than the static contact angle. After some time, due to an evaporation/adsorption process, the interface of the drop coexists with an adsorbed film of liquid molecules as part of the equilibrium configuration, denoted as the static contact angle. This equilibrium configuration is metastable because the droplet has a larger vapor pressure than the surrounding flat film. As the drop evaporates, the vapor/liquid interface contracts and the apparent contact line moves towards the center of the drop. During this process, the film left behind is thicker than the adsorbed film and molecular attraction results in a receding contact angle, smaller than the equilibrium contact angle.

  2. From plane to spatial angles: PTB's spatial angle autocollimator calibrator

    NASA Astrophysics Data System (ADS)

    Kranz, Oliver; Geckeler, Ralf D.; Just, Andreas; Krause, Michael; Osten, Wolfgang

    2015-10-01

    Electronic autocollimators are utilised versatilely for non-contact angle measurements in applications like straightness measurements and profilometry. Yet, no calibration of the angle measurement of an autocollimator has been available when both its measurement axes are engaged. Additionally, autocollimators have been calibrated at fixed distances to the reflector, although its distance may vary during the use of an autocollimator. To extend the calibration capabilities of the Physikalisch-Technische Bundesanstalt (PTB) regarding spatial angles and variable distances, a novel calibration device has been set up: the spatial angle autocollimator calibrator (SAAC). In this paper, its concept and its mechanical realisation will be presented. The focus will be on the system's mathematical modelling and its application in spatial angle calibrations. The model considers the misalignments of the SAAC's components, including the non-orthogonalities of the measurement axes of the autocollimators and of the rotational axes of the tilting unit. It allows us to derive specific measurement procedures to determine the misalignments in situ and, in turn, to correct the measurements of the autocollimators. Finally, the realisation and the results of a traceable spatial angle calibration of an autocollimator will be presented. This is the first calibration of this type worldwide.

  3. Ring magnet firing angle control

    DOEpatents

    Knott, M.J.; Lewis, L.G.; Rabe, H.H.

    1975-10-21

    A device is provided for controlling the firing angles of thyratrons (rectifiers) in a ring magnet power supply. A phase lock loop develops a smooth ac signal of frequency equal to and in phase with the frequency of the voltage wave developed by the main generator of the power supply. A counter that counts from zero to a particular number each cycle of the main generator voltage wave is synchronized with the smooth AC signal of the phase lock loop. Gates compare the number in the counter with predetermined desired firing angles for each thyratron and with coincidence the proper thyratron is fired at the predetermined firing angle.

  4. Two Comments on Bond Angles

    NASA Astrophysics Data System (ADS)

    Glaister, P.

    1997-09-01

    Tetrahedral Bond Angle from Elementary Trigonometry The alternative approach of using the scalar (or dot) product of vectors enables the determination of the bond angle in a tetrahedral molecule in a simple way. There is, of course, an even more straightforward derivation suitable for students who are unfamiliar with vectors, or products thereof, but who do know some elementary trigonometry. The starting point is the figure showing triangle OAB. The point O is the center of a cube, and A and B are at opposite corners of a face of that cube in which fits a regular tetrahedron. The required bond angle alpha = AÔB; and using Pythagoras' theorem, AB = 2(square root 2) is the diagonal of a face of the cube. Hence from right-angled triangle OEB, tan(alpha/2) = (square root 2) and therefore alpha = 2tan-1(square root 2) is approx. 109° 28' (see Fig. 1).

  5. Spinning angle optical calibration apparatus

    SciTech Connect

    Beer, S.K.; Pratt, H.R.

    1991-02-26

    This patent describes an optical calibration apparatus provided for calibrating and reproducing spinning angles in cross-polarization, nuclear magnetic resonance spectroscopy. An illuminated magnifying apparatus enables optical setting an accurate reproducing of spinning magic angles in cross-polarization, nuclear magnetic resonance spectroscopy experiments. A reference mark scribed on an edge of a spinning angle test sample holder is illuminated by a light source and viewed through a magnifying scope. When the magic angle of a sample material used as a standard is attained by varying the angular position of the sample holder, the coordinate position of the reference mark relative to a graduation or graduations on a reticle in the magnifying scope is noted.

  6. Relativistic Transformation of Solid Angle.

    ERIC Educational Resources Information Center

    McKinley, John M.

    1980-01-01

    Rederives the relativistic transformations of light intensity from compact sources (stars) to show where and how the transformation of a solid angle contributes. Discusses astrophysical and other applications of the transformations. (Author/CS)

  7. The Semiotic and Conceptual Genesis of Angle

    ERIC Educational Resources Information Center

    Tanguay, Denis; Venant, Fabienne

    2016-01-01

    In the present study, we try to understand how students at the end of primary school conceive of angle: Is an angle a magnitude for them or a geometric figure, and how do they manage to coordinate the two aspects in their understanding of the concepts of angle and of angle measurement? With the aim of better grasping the way "angle" is…

  8. Biochemical correlates of thiazolidinedione-induced adipocyte differentiation by high-resolution magic angle spinning NMR spectroscopy.

    PubMed

    Chen, Jin-Hong; Enloe, Brian M; Weybright, Patrick; Campbell, Natalee; Dorfman, David; Fletcher, Christopher D; Cory, D G; Singer, Samuel

    2002-10-01

    Thiazolidinediones, a class of synthetic ligands to the peroxisome proliferator-activated receptor-gamma, induce terminal adipocyte differentiation of 3T3 F442A cells, and have already been used as alternative therapeutic agents for the treatment of liposarcoma in clinical trials. The biochemical changes occurring in the 3T3 F442A cell line and well-differentiated liposarcoma following induction of adipocyte differentiation with the thiazolidinedione troglitazone were measured using high-resolution magic angle spinning (MAS) nuclear magnetic resonance (NMR) spectroscopy. 3T3 F442A cell differentiation was characterized by a large accumulation of intracellular triglyceride and withdrawal from the cell cycle. Phosphatidylcholine (PTC), phosphocholine (PC), myo-inositol, and glycerol were found to be possible biochemical markers for adipocyte differentiation induced by thiazolidenediones. The molar ratio of PTC to PC increased fourfold in differentiated 3T3 F442A cells compared to undifferentiated cells, suggesting a substantial increase in CTP:phosphocholine cytidylyltransferase activity with differentiation. A 2.8-fold increase in the PTC:PC ratio was observed in the lipoma-like well-differentiated liposarcoma of three patients who were treated with troglitazone when compared to liposarcoma from patients not treated with this drug. Thus, this ratio may be an NMR-detectable marker of troglitazone efficacy and response to differentiation therapy for liposarcoma.

  9. Metrology of angles in astronomy

    NASA Astrophysics Data System (ADS)

    Kovalevsky, Jean

    2004-10-01

    In astronomy, measurements of angles play a major role. After defining the units in use in astronomy, three methods of measuring angles are presented, with an application to the transit instrument. The interferometric techniques for measuring large angles are described in optical and radio wavelengths. Due to the atmospheric and mechanical limitation on ground, space astrometry has multiple advantages. The satellite Hipparcos is described and the data reduction procedures and results obtained are sketched. In the future, two new astrometric space missions are approved: GAIA, based on Hipparcos principles and SIM, a space interferometer. They are described and the expected accuracies are presented. To cite this article: J. Kovalevsky, C. R. Physique 5 (2004).

  10. Large angle measurement by interferometry

    NASA Astrophysics Data System (ADS)

    Apostol, Dan; Blanaru, Constantin; Damian, Victor S.; Logofatu, Petre-Catalin; Tumbar, R.; Dobroiu, Adrian

    1995-03-01

    An interferometric set-up able to measure angles as large as +180 degree(s) is presented. The principle of the method is to measure a linear displacement (translation) produced by a crank-gear mechanism which converts the angular movement of a rotating table. The optical scheme and consideration on the accuracy of the method are presented.

  11. Discovering the Inscribed Angle Theorem

    ERIC Educational Resources Information Center

    Roscoe, Matt B.

    2012-01-01

    Learning to play tennis is difficult. It takes practice, but it also helps to have a coach--someone who gives tips and pointers but allows the freedom to play the game on one's own. Learning to act like a mathematician is a similar process. Students report that the process of proving the inscribed angle theorem is challenging and, at times,…

  12. Angle interferometer cross axis errors

    SciTech Connect

    Bryan, J.B.; Carter, D.L.; Thompson, S.L.

    1994-01-01

    Angle interferometers are commonly used to measure surface plate flatness. An error can exist when the centerline of the double comer cube mirror assembly is not square to the surface plate and the guide bar for the mirror sled is curved. Typical errors can be one to two microns per meter. A similar error can exist in the calibration of rotary tables when the centerline of the double comer cube mirror assembly is not square to the axes of rotation of the angle calibrator and the calibrator axis is not parallel to the rotary table axis. Commercial double comer cube assemblies typically have non-parallelism errors of ten milli-radians between their centerlines and their sides and similar values for non-squareness between their centerlines and end surfaces. The authors have developed a simple method for measuring these errors and correcting them by remachining the reference surfaces.

  13. SEDIMENTATION IN THE ANGLE CENTRIFUGE.

    PubMed

    Pickels, E G

    1943-01-20

    1. Using hemocyanin from Limulus polyphemus as a test material, the process of sedimentation in the angle centrifuge, operating both in vacuum and in the open air, has been investigated. 2. Sedimentation in a given field of force was found less efficient when centrifugation was conducted in the open air, because of thermal convection. 3. Correlations have been made with results obtained in the analytical ultracentrifuge, and a theory of sedimentation in inclined tubes has been presented to explain the experimental results. 4. It has been shown that under proper conditions the angle centrifuge may be used for approximate determinations of particle size. 5. Recommendations, based mostly on experimental evidence, have been made for improving sedimentation and interpreting results. 6. To counteract convective disturbances of either thermal or inertial origin, a satisfactory method has been developed which consists of furnishing the fluid under study with a synthetic density gradient, formed with sucrose or some other non-sedimentable material.

  14. Gaia basic angle monitoring system

    NASA Astrophysics Data System (ADS)

    Gielesen, W.; de Bruijn, D.; van den Dool, T.; Kamphues, F.; Mekking, J.; Calvel, B.; Laborie, A.; Coatantiec, C.; Touzeau, S.; Erdmann, M.; Gare, P.; Monteiro, D.

    2013-09-01

    The Gaia mission1 will create an extraordinarily precise three-dimensional map of more than one billion stars in our Galaxy. The Gaia spacecraft2, built by EADS Astrium, is part of ESA's Cosmic Vision programme and scheduled for launch in 2013. Gaia measures the position, distance and motion of stars with an accuracy of 24 micro-arcsec using two telescopes at a fixed mutual angle of 106.5°, named the `Basic Angle', at an operational temperature of 100 K. This accuracy requires ultra-high stability at cryogenic conditions, which can only be achieved by using Silicon Carbide for both the optical bench and the telescopes. TNO has developed, built and space qualified the Silicon carbide Basic Angle Monitoring (BAM) on-board metrology system3 for this mission, measuring the relative motion of Gaia's telescopes with accuracies in the range of 0.5 micro-arcsec. This is achieved by a system of two laser interferometers able to detect Optical Path Differences (OPD) as small as 1.5 picometer rms. Following a general introduction on Gaia and the use of Silicon Carbide as base material this paper addresses the specific challenges towards the cryogenic application of the Gaia BAM including design, integration and verification/qualification by testing.

  15. OPENING ANGLES OF COLLAPSAR JETS

    SciTech Connect

    Mizuta, Akira; Ioka, Kunihito

    2013-11-10

    We investigate the jet propagation and breakout from the stellar progenitor for gamma-ray burst (GRB) collapsars by performing two-dimensional relativistic hydrodynamic simulations and analytical modeling. We find that the jet opening angle is given by θ{sub j} ∼ 1/5Γ{sub 0} and infer the initial Lorentz factor of the jet at the central engine, Γ{sub 0}, is a few for existing observations of θ{sub j}. The jet keeps the Lorentz factor low inside the star by converging cylindrically via collimation shocks under the cocoon pressure and accelerates at jet breakout before the free expansion to a hollow-cone structure. In this new picture, the GRB duration is determined by the sound crossing time of the cocoon, after which the opening angle widens, reducing the apparent luminosity. Some bursts violating the maximum opening angle θ{sub j,{sub max}} ∼ 1/5 ∼ 12° imply the existence of a baryon-rich sheath or a long-acting jet. We can explain the slopes in both Amati and Yonetoku spectral relations using an off-centered photosphere model, if we make only one assumption that the total jet luminosity is proportional to the initial Lorentz factor of the jet. We also numerically calibrate the pre-breakout model (Bromberg et al.) for later use.

  16. Gaia basic angle monitoring system

    NASA Astrophysics Data System (ADS)

    Gielesen, W.; de Bruijn, D.; van den Dool, T.; Kamphues, F.; Meijer, E.; Calvel, B.; Laborie, A.; Monteiro, D.; Coatantiec, C.; Touzeau, S.; Erdmann, M.; Gare, P.

    2012-09-01

    The Gaia mission will create an extraordinarily precise three-dimensional map of more than one billion stars in our Galaxy. The Gaia spacecraft, built by EADS Astrium, is part of ESA's Cosmic Vision programme and scheduled for launch in 2013. Gaia measures the position, distance and motion of stars with an accuracy of 24 micro-arcsec using two telescopes at a fixed mutual angle of 106.5°, named the ‘Basic Angle’. This accuracy requires ultra-high stability, which can only be achieved by using Silicon Carbide for both the optical bench and the telescopes. TNO has developed, built and space qualified the Silicon carbide Basic Angle Monitoring (BAM) on-board metrology system for this mission. The BAM measures the relative motion of Gaia’s telescopes with accuracies in the range of 0.5 micro-arcsec. This is achieved by a system of two laser interferometers able to measure Optical Path Differences (OPD) as small as 1.5 picometer rms. Following a general introduction to the Gaia mission, the Payload Module (PLM) and the use of Silicon Carbide as base material, this presentation will address an overview of the challenges towards the key requirements, design, integration and testing (including space-level qualification) of the Gaia BAM.

  17. A new procedure for measuring contact angle

    SciTech Connect

    Concus, P.; Finn, R.

    1994-05-01

    Described here are some recent work regarding the mathematic design of apparatus that exploits microgravity conditions for accurate experimental determination of contact angle. The underlying motivation for the procedures rests on a discontinuous dependence of the capillary free surface interface S on the contact angle {gamma}, in a cylindrical capillary tube whose section (base) {Omega} contains a protruding corner with opening angle 2{alpha}.

  18. 30 CFR 57.19037 - Fleet angles.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Fleet angles. 57.19037 Section 57.19037 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE SAFETY AND... Sheaves § 57.19037 Fleet angles. Fleet angles on hoists installed after November 15, 1979, shall not...

  19. 30 CFR 56.19037 - Fleet angles.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Fleet angles. 56.19037 Section 56.19037 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE SAFETY AND... Sheaves § 56.19037 Fleet angles. Fleet angles on hoists installed after November 15, 1979, shall not...

  20. [Chronic closed-angle glaucoma].

    PubMed

    Valtot, F

    2004-06-01

    Five times more frequent than the acute form, chronic closed-angle glaucoma often goes unrecognized for a long time, resulting in considerable visual field deficiencies, even in loss of the eye. It is sometimes confused with chronic glaucoma and treated as such, which is inadequate to halt the progression of the disease. Only gonioscopy can diagnose it. If doubt persists, UBM (ultrasound biomicroscopy) can detect goniosynechiae, a malposition of the ciliary body or of the lens, or the existence of iridociliary cysts. Nine times out of ten, pupillary block initiates the process and an iridotomy should always be done to remediate it, even if this procedure alone does not always suffice to solve the problem. PMID:15319750

  1. Individualized optimal release angles in discus throwing.

    PubMed

    Leigh, Steve; Liu, Hui; Hubbard, Mont; Yu, Bing

    2010-02-10

    The purpose of this study was to determine individualized optimal release angles for elite discus throwers. Three-dimensional coordinate data were obtained for at least 10 competitive trials for each subject. Regression relationships between release speed and release angle, and between aerodynamic distance and release angle were determined for each subject. These relationships were linear with subject-specific characteristics. The subject-specific relationships between release speed and release angle may be due to subjects' technical and physical characteristics. The subject-specific relationships between aerodynamic distance and release angle may be due to interactions between the release angle, the angle of attack, and the aerodynamic distance. Optimal release angles were estimated for each subject using the regression relationships and equations of projectile motion. The estimated optimal release angle was different for different subjects, and ranged from 35 degrees to 44 degrees . The results of this study demonstrate that the optimal release angle for discus throwing is thrower-specific. The release angles used by elite discus throwers in competition are not necessarily optimal for all discus throwers, or even themselves. The results of this study provide significant information for understanding the biomechanics of discus throwing techniques.

  2. Axial Tilt Angles of Active Regions

    NASA Astrophysics Data System (ADS)

    Howard, Robert F.

    1996-12-01

    Separate Mount Wilson plage and sunspot group data sets are analyzed in this review to illustrate several interesting aspects of active region axial tilt angles. (1) The distribution of tilt angles differs between plages and sunspot groups in the sense that plages have slightly higher tilt angles, on average, than do spot groups. (2) The distributions of average plage total magnetic flux, or sunspot group area, with tilt angle show a consistent effect: those groups with tilt angles nearest the average values are larger (or have a greater total flux) on average than those farther from the average values. Moreover, the average tilt angles on which these size or flux distributions are centered differ for the two types of objects, and represent closely the actual different average tilt angles for these two features. (3) The polarity separation distances of plages and sunspot groups show a clear relationship to average tilt angles. In the case of each feature, smaller polarity separations are correlated with smaller tilt angles. (4) The dynamics of regions also show a clear relationship with region tilt angles. The spot groups with tilt angles nearest the average value (or perhaps 0-deg tilt angle) have on average a faster rotation rate than those groups with extreme tilt angles. All of these tilt-angle characteristics may be assumed to be related to the physical forces that affect the magnetic flux loop that forms the region. These aspects are discussed in this brief review within the context of our current view of the formation of active region magnetic flux at the solar surface.

  3. Dynamic contact angle measurements on superhydrophobic surfaces

    NASA Astrophysics Data System (ADS)

    Kim, Jeong-Hyun; Kavehpour, H. Pirouz; Rothstein, Jonathan P.

    2015-03-01

    In this paper, the dynamic advancing and receding contact angles of a series of aqueous solutions were measured on a number of hydrophobic and superhydrophobic surfaces using a modified Wilhelmy plate technique. Superhydrophobic surfaces are hydrophobic surfaces with micron or nanometer sized surface roughness. These surfaces have very large static advancing contact angles and little static contact angle hysteresis. In this study, the dynamic advancing and dynamic receding contact angles on superhydrophobic surfaces were measured as a function of plate velocity and capillary number. The dynamic contact angles measured on a smooth hydrophobic Teflon surface were found to obey the scaling with capillary number predicted by the Cox-Voinov-Tanner law, θD3 ∝ Ca. The response of the dynamic contact angle on the superhydrophobic surfaces, however, did not follow the same scaling law. The advancing contact angle was found to remain constant at θA = 160∘, independent of capillary number. The dynamic receding contact angle measurements on superhydrophobic surfaces were found to decrease with increasing capillary number; however, the presence of slip on the superhydrophobic surface was found to result in a shift in the onset of dynamic contact angle variation to larger capillary numbers. In addition, a much weaker dependence of the dynamic contact angle on capillary number was observed for some of the superhydrophobic surfaces tested.

  4. Angled Layers in Super Resolution

    NASA Technical Reports Server (NTRS)

    2004-01-01

    Researchers used a special imaging technique with the panoramic camera on NASA's Mars Exploration Rover Opportunity to get as detailed a look as possible at a target region near eastern foot of 'Burns Cliff.' The intervening terrain was too difficult for driving the rover closer. The target is the boundary between two sections of layered rock. The layers in lower section (left) run at a marked angle to the layers in next higher section (right).

    This view is the product of a technique called super resolution. It was generated from data acquired on sol 288 of Opportunity's mission (Nov. 14, 2004) from a position along the southeast wall of 'Endurance Crater.' Resolution slightly higher than normal for the panoramic camera was synthesized for this view by combining 17 separate images of this scene, each one 'dithered' or pointed slightly differently from the previous one. Computer manipulation of the individual images was then used to generate a new synthetic view of the scene in a process known mathematically as iterative deconvolution, but referred to informally as super resolution. Similar methods have been used to enhance the resolution of images from the Mars Pathfinder mission and the Hubble Space Telescope.

  5. Chronic open-angle glaucoma

    PubMed Central

    Adatia, Feisal A.; Damji, Karim F.

    2005-01-01

    INTRODUCTION Chronic open-angle glaucoma (COAG) is a leading cause of irreversible blindness worldwide, including in Canada. It presents a challenge in diagnosis, as disease often progresses without symptoms; an estimated 50% of cases are undetected. SOURCES OF INFORMATION MEDLINE searches, reference lists of articles, and expert knowledge from one of the authors (K.F.D.), a glaucoma specialist, were used. MAIN MESSAGE A casefinding approach using early referral to optometrists and ophthalmologists for early detection of COAG is helpful for patients with risk factors such as age above 50, a positive family history, black race, and myopia. Moderate evidence for referral also exists for the following risk factors: hypertension, type 2 diabetes mellitus, hypothyroidism, and sleep apnea. Treatment with intraocular pressure–lowering medication can arrest or slow the course of the disease, permitting patients to retain good visual function. Family physicians should be aware that some intraocular pressure–lowering medications, particularly topical beta-blockers, can pose iatrogenic harm to patients and result in or exacerbate such conditions as asthma, cardiovascular disturbances, depression, and sexual dysfunction. CONCLUSION Appropriate referral patterns and an understanding of common as well as serious side effects of glaucoma medications are important in optimizing management of patients at risk of developing, or who have, COAG. PMID:16190176

  6. Dual-view angle backlight module design.

    PubMed

    Chen, Bo-Tsuen; Pan, Jui-Wen

    2015-10-01

    We propose a bilayer light guide plate (BLGP) with specially designed microstructures and two light source modules to achieve an adjustable viewing angle backlight for ecofriendly displays. The dual viewing angle backlight module has a thin, simple structure and a high optical efficiency. Comparison with the conventional edge-lit backlight module shows an improvement in the on-axis luminance of the narrow viewing angle mode of 4.3 times and a decrease in the half-luminance angle of 7° in the horizontal direction. When using the wide viewing angle mode, there is an improvement in the on-axis luminance of 1.8 times and an improvement in the half-luminance angle of 54° in the horizontal direction. The uniformity of illuminance can reach 80% in each mode. The backlight optical sheet number is reduced from 5 to 1. PMID:26479670

  7. Signature extension for sun angle, volume 1

    NASA Technical Reports Server (NTRS)

    Smith, J. A. (Principal Investigator); Berry, J. K.; Heimes, F.

    1975-01-01

    The author has identified the following significant results. Within a restricted zenith sun angle range of 35 - 50 degrees, it was empirically observed that canopy reflectance is mainly Lambertian. Reflectance changes with crop stage were simple shifts in scale in the sun angle range. It was noted that sun angle variations depend on canopy characteristics. Effects of the vegetative canopy were most pronounced at the larger solar zenith angles (20 %). The linear sun angle correction coefficients demonstrate a dependency on both crop stage (15-20 %) and crop type (10-20 %). The use of canopy reflectance modeling allowed for the generation of a simulated data set over an extremely broad envelope of sun angles.

  8. The Retroacetabular Angle Determines the Safe Angle for Screw Placement in Posterior Acetabular Fracture Fixation

    PubMed Central

    Tadros, Ayman M. A.; Oxland, Thomas R.; O'Brien, Peter

    2013-01-01

    Introduction. A method for the determination of safe angles for screws placed in the posterior acetabular wall based on preoperative computed tomography (CT) is described. It defines a retroacetabular angle and determines its variation in the population. Methods. The retroacetabular angle is the angle between the retroacetabular surface and the tangent to the posterior acetabular articular surface. Screws placed through the marginal posterior wall at an angle equal to the retroacetabular angle are extraarticular. Medial screws can be placed at larger angles whose difference from the retroacetabular angle is defined as the allowance angles. CT scans of all patients with acetabular fractures treated in our institute between September 2002 to July 2007 were used to measure the retroacetabular angle and tangent. Results. Two hundred thirty one patients were included. The average (range) age was 42 (15–74) years. The average (range) retroacetabular angle was 39 (30–47) degrees. The average (range) retroacetabular tangent was 36 (30–45) mm. Conclusions. Placing the screws at an average (range) angle of 39 (33–47) degrees of anterior inclination with the retroacetabular surface makes them extraarticular. Angles for medial screws are larger. Safe angles can be calculated preoperatively with a computer program. PMID:24959359

  9. Behavior of Tilted Angle Shear Connectors.

    PubMed

    Khorramian, Koosha; Maleki, Shervin; Shariati, Mahdi; Ramli Sulong, N H

    2015-01-01

    According to recent researches, angle shear connectors are appropriate to transfer longitudinal shear forces across the steel-concrete interface. Angle steel profile has been used in different positions as L-shaped or C-shaped shear connectors. The application of angle shear connectors in tilted positions is of interest in this study. This study investigates the behaviour of tilted-shaped angle shear connectors under monotonic loading using experimental push out tests. Eight push-out specimens are tested to investigate the effects of different angle parameters on the ultimate load capacity of connectors. Two different tilted angles of 112.5 and 135 degrees between the angle leg and steel beam are considered. In addition, angle sizes and lengths are varied. Two different failure modes were observed consisting of concrete crushing-splitting and connector fracture. By increasing the size of connector, the maximum load increased for most cases. In general, the 135 degrees tilted angle shear connectors have a higher strength and stiffness than the 112.5 degrees type.

  10. Dynamic-angle spinning without sidebands

    NASA Astrophysics Data System (ADS)

    Gann, S. L.; Baltisberger, J. H.; Pines, A.

    1993-07-01

    By means of rotor-synchronized π-pulses, it is possible to eliminate the spinning sidebands (while retaining their full intensity in the isotropic centerband) that usually arise in dynamic-angle spinning (DAS) NMR. The theory of this approach, dynamic-angle hopping (DAH-180), is described and illustrated with experimental results on quadrupolar nuclei. A magic-angle hopping (MAH-180) version of magic-angle spinning is also possible and can be used in a two-dimensional NMR experiment to produce sideband-free isotropic—anisotropic correlation spectra for spin- 1/2 nuclei.

  11. Behavior of Tilted Angle Shear Connectors

    PubMed Central

    Khorramian, Koosha; Maleki, Shervin; Shariati, Mahdi; Ramli Sulong, N. H.

    2015-01-01

    According to recent researches, angle shear connectors are appropriate to transfer longitudinal shear forces across the steel-concrete interface. Angle steel profile has been used in different positions as L-shaped or C-shaped shear connectors. The application of angle shear connectors in tilted positions is of interest in this study. This study investigates the behaviour of tilted-shaped angle shear connectors under monotonic loading using experimental push out tests. Eight push-out specimens are tested to investigate the effects of different angle parameters on the ultimate load capacity of connectors. Two different tilted angles of 112.5 and 135 degrees between the angle leg and steel beam are considered. In addition, angle sizes and lengths are varied. Two different failure modes were observed consisting of concrete crushing-splitting and connector fracture. By increasing the size of connector, the maximum load increased for most cases. In general, the 135 degrees tilted angle shear connectors have a higher strength and stiffness than the 112.5 degrees type. PMID:26642193

  12. A Climbing Class' Reinvention of Angles

    ERIC Educational Resources Information Center

    Fyhn, Anne Birgitte

    2008-01-01

    A previous study shows how a twelve-year-old girl discovers angles in her narrative from a climbing trip. Based on this research, the girl's class takes part in one day of climbing and half a day of follow-up work at school. The students mathematise their climbing with respect to angles and they express themselves in texts and drawings. Their…

  13. Automatic star-horizon angle measurement system

    NASA Technical Reports Server (NTRS)

    Koerber, K.; Koso, D. A.; Nardella, P. C.

    1969-01-01

    Automatic star horizontal angle measuring aid for general navigational use incorporates an Apollo type sextant. The eyepiece of the sextant is replaced with two light detectors and appropriate circuitry. The device automatically determines the angle between a navigational star and a unique point on the earths horizon as seen on a spacecraft.

  14. The SU(2) action-angle variables

    NASA Technical Reports Server (NTRS)

    Ellinas, Demosthenes

    1993-01-01

    Operator angle-action variables are studied in the frame of the SU(2) algebra, and their eigenstates and coherent states are discussed. The quantum mechanical addition of action-angle variables is shown to lead to a noncommutative Hopf algebra. The group contraction is used to make the connection with the harmonic oscillator.

  15. Let's Do It! Using Geostrips and "Angle-Fixers" to Develop Ideas About Shapes and Angles

    ERIC Educational Resources Information Center

    Bruni, James V.; Silverman, Helene

    1975-01-01

    Homemade geostrips, "angle-fixers" (cardboard circular sectors) and brass fasteners can be used by students to explore properties of angles, triangles and other polygons. Several games and other activities are suggested. (SD)

  16. Experimental study of crossing angle collision

    SciTech Connect

    Chen, T.; Rice, D.; Rubin, D.; Sagan, D.; Tigner, M.

    1993-05-01

    The non-linear coupling due to the beam-beam interaction with crossing angle has been studied. The major effect of a small ({approximately}12mrad) crossing angle is to excite 5Q{sub x}{plus_minus}Q{sub s}=integer coupling resonance family on large amplitude particles, which results in bad lifetime. On the CESR, a small crossing angle ({approximately}2.4mr) was created at the IP and a reasonable beam-beam tune-shift was achieved. The decay rate of the beam is measured as a function of horizontal tune with and without crossing angle. The theoretical analysis, simulation and experimental measurements have a good agreement. The resonance strength as a function of crossing angle is also measured.

  17. Caustic graphene plasmons with Kelvin angle

    NASA Astrophysics Data System (ADS)

    Shi, Xihang; Lin, Xiao; Gao, Fei; Xu, Hongyi; Yang, Zhaoju; Zhang, Baile

    2015-08-01

    A century-long argument made by Lord Kelvin that all swimming objects have an effective Mach number of 3, corresponding to a Kelvin angle of 19.5° for ship waves, has been challenged recently with the conclusion that the Kelvin angle should gradually transit to the Mach angle as the ship's velocity increases. Here we show that a similar phenomenon can happen for graphene plasmons. By analyzing the caustic wave pattern of graphene plasmons stimulated by a swift charged particle moving uniformly above graphene, we show that at low velocities of the charged particle, the caustics of graphene plasmons form the Kelvin angle. At large velocities of the particle, the caustics disappear and the effective semiangle of the wave pattern approaches the Mach angle. Our study introduces caustic wave theory to the field of graphene plasmonics, and reveals a physical picture of graphene plasmon excitation during electron energy-loss spectroscopy measurements.

  18. Identification of a YAC spanning the translocation breakpoints in uterine leiomyomata, pulmonary chondroid hamartoma, and lipoma: Physical mapping of the 12q14-q15 breakpoint region in uterine leiomyomata

    SciTech Connect

    Fejzo, M.S.; Yoon, S.J.; Kucherlapati, R.S.

    1995-03-20

    Uterine leiomyomata are the most common tumors in women and can cause abnormal uterine bleeding, pelvic pain, and infertility. Approximately 200,000 hysterectomies are performed annually in the U.S. to relieve patients of the medical sequelae of these benign neoplasms. Our efforts have focused on cloning the t(12;14)(q14-q15;q23-q24) breakpoint in uterine leiomyoma to further our understanding of the biology of these tumors. Thirty-nine YACs and six cosmids mapping to 12q14-q15 have been mapped by fluorescence in situ hybridization to tumor metaphase chromosomes containing a t(12;14). One YAC spanned the translocation breakpoint and was mapped to tumor metaphases from a pulmonary chondroid hamartoma containing a t(12;14)(q14-q15;q23-q24) and a lipoma containing a t(12;15)(q15;q24); this YAC also spanned the breakpoint in these two tumors, suggesting that the same gene on chromosome 12 may be involved in the pathobiology of these distinct benign neoplasms. 41 refs., 2 figs., 1 tab.

  19. Branes at angles from worldvolume actions

    NASA Astrophysics Data System (ADS)

    Abbaspur, Reza

    2016-05-01

    We investigate possible stable configurations of two arbitrary branes at general angles using the dynamics of DBI + WZ action. The analysis naturally reveals two types of solutions which we identify as the "marginal" and "non-marginal" configurations. We characterize possible configurations of a pair of identical or non-identical branes in either of these two classes by specifying their proper intersection rules and allowed intersection angles. We also perform a partial analysis of configurations with multiple angles of a system of asymptotically flat curved branes.

  20. Phase-angle controller for Stirling engines

    SciTech Connect

    Frosch, R.A.; McDougal, A.R.

    1980-12-23

    A first embodiment incorporating an actuator including a restraint link adapted to be connected with a pivotal carrier arm for a force transfer gear interposed between the crankshaft for an expander portion of a stirling engine and a crankshaft for the displacer portion of the engine is described. The restraint link is releasably supported against axial displacement by releasably trapped hydraulic fluid for selectively establishing a phase angle relationship between the crankshaft and a second embodiment incorporating a hydraulic coupler for use in varying the phase angle of gear-coupled crankshafts for a Stirling engine whereby phase angle changes are obtainable.

  1. Wide-angle vision for road views

    NASA Astrophysics Data System (ADS)

    Huang, F.; Fehrs, K.-K.; Hartmann, G.; Klette, R.

    2013-03-01

    The field-of-view of a wide-angle image is greater than (say) 90 degrees, and so contains more information than available in a standard image. A wide field-of-view is more advantageous than standard input for understanding the geometry of 3D scenes, and for estimating the poses of panoramic sensors within such scenes. Thus, wide-angle imaging sensors and methodologies are commonly used in various road-safety, street surveillance, street virtual touring, or street 3D modelling applications. The paper reviews related wide-angle vision technologies by focusing on mathematical issues rather than on hardware.

  2. Phase-angle controller for Stirling engines

    NASA Technical Reports Server (NTRS)

    Mcdougal, A. R. (Inventor)

    1980-01-01

    An actuator includes a restraint link adapted to be connected with a pivotal carrier arm for a force transfer gear interposed between the crankshaft for an expander portion of a Stirling engine and a crankshaft for the displacer portion of the engine. The restraint link is releasably trapped hydraulic fluid for selectively establishing a phase angle relationship between the crankshaft. A second embodiment incorporates a hydraulic coupler for use in varying the phase angle of gear-coupled crank fpr a Stirling engine whereby phase angle changes are obtainable.

  3. High angle conveyors climb to the top

    SciTech Connect

    Mitchell, J.J.

    1984-11-01

    Descriptions are presented of various types of high angle conveyors, including pocket belt, fin belt, sandwich belt, snake sandwich conveyor, mechanically pressed sandwich conveyor, and pneumatically pressed sandwich conveyors. 10 references.

  4. High angle conveyors climb to the top

    SciTech Connect

    Mitchell, J.J.

    1984-11-01

    A major objective in the design of a storage facility is to have the least handling over the shortest distances and to optimize land usage by attaining the highest tons-per-acre value. The advantages of high angle conveyors become apparent when the height of lift is compared with the surface area. High angle conveyors achieve high capacities in the least amount of space. Continental Conveyor and Equipment Co., has conducted several studies that evaluate the technical and economic feasibility of using high angle conveyors in conveyor systems. A few of the high angle conveying concepts reviewed are the bucket ladder or pocket belt, belts with partitions or fin belt, and the sandwich type belt conveyors.

  5. SOLARMAX/Electron Pitch Angle Anisotropy Distributions

    NASA Technical Reports Server (NTRS)

    McKenzie, David L.; Anderson, Phillip C.

    2002-01-01

    This final research report summarizes the scientific work performed by The Aerospace Corporation on SOLARMAX/Electron Pitch Angle Anisotropy Distributions. The period of performance was from June 1, 2000 to December 31, 2001.

  6. Nucleation of small-angle boundaries

    SciTech Connect

    Nabarro, F.R.N. |; Wilsdorf, D.K.

    1996-12-01

    The internal stresses induced by the strain gradients in an array of lattice cells delineated by low-angle dislocation boundaries are partially relieved by the creation of new low-angle boundaries. This is shown to be a first-order transition, the new boundaries having finite misorientations. The calculated misorientations both of the new boundaries and of the existing boundaries which provoke the transition agree well with observations.

  7. Winding angles of long lattice walks

    NASA Astrophysics Data System (ADS)

    Hammer, Yosi; Kantor, Yacov

    2016-07-01

    We study the winding angles of random and self-avoiding walks (SAWs) on square and cubic lattices with number of steps N ranging up to 107. We show that the mean square winding angle <θ2> of random walks converges to the theoretical form when N → ∞. For self-avoiding walks on the square lattice, we show that the ratio <θ4>/<θ2>2 converges slowly to the Gaussian value 3. For self-avoiding walks on the cubic lattice, we find that the ratio <θ4>/<θ2>2 exhibits non-monotonic dependence on N and reaches a maximum of 3.73(1) for N ≈ 104. We show that to a good approximation, the square winding angle of a self-avoiding walk on the cubic lattice can be obtained from the summation of the square change in the winding angles of lnN independent segments of the walk, where the ith segment contains 2i steps. We find that the square winding angle of the ith segment increases approximately as i0.5, which leads to an increase of the total square winding angle proportional to (lnN)1.5.

  8. Neutron spin echo scattering angle measurement (SESAME)

    SciTech Connect

    Pynn, R.; Fitzsimmons, M.R.; Fritzsche, H.; Gierlings, M.; Major, J.; Jason, A.

    2005-05-15

    We describe experiments in which the neutron spin echo technique is used to measure neutron scattering angles. We have implemented the technique, dubbed spin echo scattering angle measurement (SESAME), using thin films of Permalloy electrodeposited on silicon wafers as sources of the magnetic fields within which neutron spins precess. With 30-{mu}m-thick films we resolve neutron scattering angles to about 0.02 deg. with neutrons of 4.66 A wavelength. This allows us to probe correlation lengths up to 200 nm in an application to small angle neutron scattering. We also demonstrate that SESAME can be used to separate specular and diffuse neutron reflection from surfaces at grazing incidence. In both of these cases, SESAME can make measurements at higher neutron intensity than is available with conventional methods because the angular resolution achieved is independent of the divergence of the neutron beam. Finally, we discuss the conditions under which SESAME might be used to probe in-plane structure in thin films and show that the method has advantages for incident neutron angles close to the critical angle because multiple scattering is automatically accounted for.

  9. Modelling PTB's spatial angle autocollimator calibrator

    NASA Astrophysics Data System (ADS)

    Kranz, Oliver; Geckeler, Ralf D.; Just, Andreas; Krause, Michael

    2013-05-01

    The accurate and traceable form measurement of optical surfaces has been greatly advanced by a new generation of surface profilometers which are based on the reflection of light at the surface and the measurement of the reflection angle. For this application, high-resolution electronic autocollimators provide accurate and traceable angle metrology. In recent years, great progress has been made at the Physikalisch-Technische Bundesanstalt (PTB) in autocollimator calibration. For an advanced autocollimator characterisation, a novel calibration device has been built up at PTB: the Spatial Angle Autocollimator Calibrator (SAAC). The system makes use of an innovative Cartesian arrangement of three autocollimators (two reference autocollimators and the autocollimator to be calibrated), which allows a precise measurement of the angular orientation of a reflector cube. Each reference autocollimator is sensitive primarily to changes in one of the two relevant tilt angles, whereas the autocollimator to be calibrated is sensitive to both. The distance between the reflector cube and the autocollimator to be calibrated can be varied flexibly. In this contribution, we present the SAAC and aspects of the mathematical modelling of the system for deriving analytical expressions for the autocollimators' angle responses. These efforts will allow advancing the form measurement substantially with autocollimator-based profilometers and approaching fundamental measurement limits. Additionally, they will help manufacturers of autocollimators to improve their instruments and will provide improved angle measurement methods for precision engineering.

  10. Winding angles of long lattice walks.

    PubMed

    Hammer, Yosi; Kantor, Yacov

    2016-07-01

    We study the winding angles of random and self-avoiding walks (SAWs) on square and cubic lattices with number of steps N ranging up to 10(7). We show that the mean square winding angle 〈θ(2)〉 of random walks converges to the theoretical form when N → ∞. For self-avoiding walks on the square lattice, we show that the ratio 〈θ(4)〉/〈θ(2)〉(2) converges slowly to the Gaussian value 3. For self-avoiding walks on the cubic lattice, we find that the ratio 〈θ(4)〉/〈θ(2)〉(2) exhibits non-monotonic dependence on N and reaches a maximum of 3.73(1) for N ≈ 10(4). We show that to a good approximation, the square winding angle of a self-avoiding walk on the cubic lattice can be obtained from the summation of the square change in the winding angles of lnN independent segments of the walk, where the ith segment contains 2(i) steps. We find that the square winding angle of the ith segment increases approximately as i(0.5), which leads to an increase of the total square winding angle proportional to (lnN)(1.5). PMID:27394124

  11. Management of Primary Angle-Closure Glaucoma.

    PubMed

    Lai, Jimmy; Choy, Bonnie N K; Shum, Jennifer W H

    2016-01-01

    Primary angle-closure glaucoma (PACG) is a progressive optic nerve degeneration and is defined as a glaucomatous optic neuropathy with associated characteristic enlargement of optic disc cupping and visual field loss that is secondary to ocular hypertension caused by closure of the drainage angle. Angle closure is caused by appositional approximation or adhesion between the iris and the trabecular meshwork. The main treatment strategy for PACG lies in the reduction of intraocular pressure, reopening of the closed angle, and possible prevention of further angle closure. There is no universally agreed best surgical treatment for PACG. Trabeculectomy, goniosynechialysis (GSL), glaucoma implant, and cyclodestructive procedures are effective surgical options. Each of them plays an important role in the management of PACG with its own pros and cons. Accumulating evidence is available to show the effectiveness of visually significant and visually nonsignificant cataract extraction in the treatment of PACG. Trabeculectomy and GSL are often combined with cataract extraction, which may offer additional pressure control benefits to patients with PACG. This review article will discuss laser peripheral iridotomy, argon laser peripheral iridoplasty, and surgeries such as GSL, phacoemulsification, and phaco plus glaucoma surgeries that lower intraocular pressure and also alter the anterior segment and/or drainage angle anatomy. Currently, glaucoma implants and cyclodestruction are mainly reserved for PACG patients who have failed previous filtering operations. Their role as initial surgical treatment for PACG will not be discussed. PMID:26886121

  12. Solar cell angle of incidence corrections

    NASA Technical Reports Server (NTRS)

    Burger, Dale R.; Mueller, Robert L.

    1995-01-01

    Literature on solar array angle of incidence corrections was found to be sparse and contained no tabular data for support. This lack along with recent data on 27 GaAs/Ge 4 cm by 4 cm cells initiated the analysis presented in this paper. The literature cites seven possible contributors to angle of incidence effects: cosine, optical front surface, edge, shadowing, UV degradation, particulate soiling, and background color. Only the first three are covered in this paper due to lack of sufficient data. The cosine correction is commonly used but is not sufficient when the incident angle is large. Fresnel reflection calculations require knowledge of the index of refraction of the coverglass front surface. The absolute index of refraction for the coverglass front surface was not known nor was it measured due to lack of funds. However, a value for the index of refraction was obtained by examining how the prediction errors varied with different assumed indices and selecting the best fit to the set of measured values. Corrections using front surface Fresnel reflection along with the cosine correction give very good predictive results when compared to measured data, except there is a definite trend away from predicted values at the larger incident angles. This trend could be related to edge effects and is illustrated by a use of a box plot of the errors and by plotting the deviation of the mean against incidence angle. The trend is for larger deviations at larger incidence angles and there may be a fourth order effect involved in the trend. A chi-squared test was used to determine if the measurement errors were normally distributed. At 10 degrees the chi-squared test failed, probably due to the very small numbers involved or a bias from the measurement procedure. All other angles showed a good fit to the normal distribution with increasing goodness-of-fit as the angles increased which reinforces the very small numbers hypothesis. The contributed data only went to 65 degrees

  13. Longitudinal Changes of Angle Configuration in Primary Angle-Closure Suspects

    PubMed Central

    Jiang, Yuzhen; Chang, Dolly S.; Zhu, Haogang; Khawaja, Anthony P.; Aung, Tin; Huang, Shengsong; Chen, Qianyun; Munoz, Beatriz; Grossi, Carlota M.

    2015-01-01

    Objective To determine longitudinal changes in angle configuration in the eyes of primary angle-closure suspects (PACS) treated by laser peripheral iridotomy (LPI) and in untreated fellow eyes. Design Longitudinal cohort study. Participants Primary angle-closure suspects aged 50 to 70 years were enrolled in a randomized, controlled clinical trial. Methods Each participant was treated by LPI in 1 randomly selected eye, with the fellow eye serving as a control. Angle width was assessed in a masked fashion using gonioscopy and anterior segment optical coherence tomography (AS-OCT) before and at 2 weeks, 6 months, and 18 months after LPI. Main Outcome Measures Angle width in degrees was calculated from Shaffer grades assessed under static gonioscopy. Angle configuration was also evaluated using angle opening distance (AOD250, AOD500, AOD750), trabecular-iris space area (TISA500, TISA750), and angle recess area (ARA) measured in AS-OCT images. Results No significant difference was found in baseline measures of angle configuration between treated and untreated eyes. At 2 weeks after LPI, the drainage angle on gonioscopy widened from a mean of 13.5° at baseline to a mean of 25.7° in treated eyes, which was also confirmed by significant increases in all AS-OCT angle width measures (P<0.001 for all variables). Between 2 weeks and 18 months after LPI, a significant decrease in angle width was observed over time in treated eyes (P<0.001 for all variables), although the change over the first 5.5 months was not statistically significant for angle width measured under gonioscopy (P = 0.18), AOD250 (P = 0.167) and ARA (P = 0.83). In untreated eyes, angle width consistently decreased across all follow-up visits after LPI, with a more rapid longitudinal decrease compared with treated eyes (P values for all variables ≤0.003). The annual rate of change in angle width was equivalent to 1.2°/year (95% confidence interval [CI], 0.8–1.6) in treated eyes and 1.6°/year (95% CI, 1

  14. Fractal Approach in Petrology: Combining Ultra-Small Angle (USANA) and Small Angle Neutron Scattering (SANS)

    SciTech Connect

    LoCelso, F.; Triolo, F.; Triolo, A.; Lin, J.S.; Lucido, G.; Triolo, R.

    1999-10-14

    Ultra small angle neutron scattering instruments have recently covered the gap between the size resolution available with conventional intermediate angle neutron scattering and small angle neutron scattering instruments on one side and optical microscopy on the other side. Rocks showing fractal behavior in over two decades of momentum transfer and seven orders of magnitude of intensity are examined and fractal parameters are extracted from the combined USANS and SANS curves.

  15. Patellar Tendon–Trochlear Groove Angle Measurement

    PubMed Central

    Hinckel, Betina B.; Gobbi, Riccardo G.; Kihara Filho, Eduardo N.; Demange, Marco K.; Pécora, José Ricardo; Camanho, Gilberto Luis

    2015-01-01

    Background: The tibial tubercle–trochlear groove (TT-TG) is used as the gold standard for patellofemoral malalignment. Purpose: To assess 3 patellar tendon–trochlear groove (PT-TG) angle measurement techniques and the PT-TG distance measurement (tendinous cartilaginous TT-TG) as predictors of patellar instability. Study Design: Cohort study (diagnosis); Level of evidence, 3. Methods: Three PT-TG angle measurements and the PT-TG distance were measured in 82 participants with patellar instability and 100 controls using magnetic resonance imaging (MRI). Measurement landmarks were the line tangent to the posterior femoral condyles, the deepest point of the trochlea, the transepicondylar line, and the patellar tendon center. All measurements were recorded once by 1 examiner, and the measurements were recorded twice by 2 examiners in a random group of 100 knees. Mean values and standard deviations (SDs) were obtained. Normality cutoff values were defined as 2 and 3 SDs above the mean in the control group. The sensitivity, specificity, and positive likelihood ratio (LR+) were calculated. Inter- and intrarater reliability were assessed based on the intraclass correlation coefficient (ICC). Results: The measurements from the patellar instability and control groups, respectively, for angle 1 (16.4° and 8.4°), angle 2 (31° and 15.6°), angle 3 (30.8° and 15.7°), PT-TG distance (14.5 and 8.4 mm), and patellar tilt (21.1° and 7.5°) were significantly different (P < .05). The angle measurements showed greater sensitivity, specificity, and LR+ than the PT-TG distance. Inter- and intrarater ICC values were >0.95 for all measurements. Conclusion: The PT-TG angle and the PT-TG distance are reliable and are different between the patellar instability and control groups. PT-TG angles are more closely associated with patellar instability than PT-TG distance. Clinical Relevance: PT-TG angle measurements show high reliability and association with patellar instability and can

  16. A Viewpoint on the Quantity "Plane Angle"

    NASA Astrophysics Data System (ADS)

    Eder, W. E.

    1982-01-01

    Properties of the quantity "plane angle" are explored under the hypothesis that it is a dimensional quantity. The exploration proceeds especially with respect to the physical concept, its mathematical treatment, vector concepts, measurement theory, units of related quantities, engineering pragmatism, and SI. An attempt is made to bring these different relations into a rational, logical and consistent framework, and thus to justify the hypothesis. Various types of vectorial quantities are recognized, and their properties described with an outline of the necessary algebraic manipulations. The concept of plane angle is amplified, and its interdependence with the circular arc is explored. The resulting units of plane angle form a class of similar scales of measurement. Consequences of the confirmed hypothesis are developed for mathematical expressions involving trigonometric functions, rotational volumes and areas, mathematical limits, differentiation and series expansion. Consequences for mechanical rotational quantities are developed, with proposals for revisions to a number of expressions for derived units within SI. A revised definition for the quantity "plane angle" is stated to take account of the developed insights. There is a clear need to reconsider the status of plane angle and some other quantities within the international framework of SI.

  17. Incident Angle Dependence of Organic Solar Cells

    NASA Astrophysics Data System (ADS)

    Degeorge, Vincent; Valle, Brent; Singer, Kenneth

    2010-10-01

    We have been recently studying the use of interference effects to enhance optical absorption in polymer photovoltaic cells. These interference effects are expected to be angle dependent. We measure here the angle dependent absorption and compare with numerical simulations. The cells used were P3HT/PCBM active layer, organic photovoltaic cells. The angular dependence of the cells' reflection was measured using an Ocean Optics light source and spectrophotometer and a precision rotary stage apparatus. The experimental results were compared to a Matlab simulation of the characteristic matrix problem. Analysis showed that the reflection/absorption peaks predicted by the simulation largely coincided in wavelength to those observed in experiment. Moreover, no additional cavity resonance can be attributed to incidence angle.

  18. Bicycle helmet ventilation and comfort angle dependence.

    PubMed

    Brühwiler, Paul A; Ducas, Charline; Huber, Roman; Bishop, Phillip A

    2004-09-01

    Five modern bicycle helmets were studied to elucidate some of the variations in ventilation performance, using both a heated manikin headform and human subjects (n = 7). Wind speed and head angle were varied to test their influence on the measured steady-state heat exchange (cooling power) in the skull section of the headform. The cooling power transmitted by the helmets varied from about 60% to over 90% of that of the nude headform, illustrating the range of present manufacturer designs. Angling the head forward by 30 degrees was found to provide better cooling power to the skull (up to 25%) for three of the helmets and almost equal cooling power in the remaining two cases. Comparisons of skull ventilation at these angles with human subjects strongly supported the headform results.

  19. Flocking and invariance of velocity angles.

    PubMed

    Liu, Le; Huang, Lihong; Wu, Jianhong

    2016-04-01

    Motsch and Tadmor considered an extended Cucker-Smale model to investigate the flocking behavior of self-organized systems of interacting species. In this extended model, a cone of the vision was introduced so that outside the cone the influence of one agent on the other is lost and hence the corresponding influence function takes the value zero. This creates a problem to apply the Motsch-Tadmor and Cucker-Smale method to prove the flocking property of the system. Here, we examine the variation of the velocity angles between two arbitrary agents, and obtain a monotonicity property for the maximum cone of velocity angles. This monotonicity permits us to utilize existing arguments to show the flocking property of the system under consideration, when the initial velocity angles satisfy some minor technical constraints. PMID:27105986

  20. High brightness angled cavity quantum cascade lasers

    SciTech Connect

    Heydari, D.; Bai, Y.; Bandyopadhyay, N.; Slivken, S.; Razeghi, M.

    2015-03-02

    A quantum cascade laser (QCL) with an output power of 203 W is demonstrated in pulsed mode at 283 K with an angled cavity. The device has a ridge width of 300 μm, a cavity length of 5.8 mm, and a tilt angle of 12°. The back facet is high reflection coated, and the front facet is anti-reflection coated. The emitting wavelength is around 4.8 μm. In distinct contrast to a straight cavity broad area QCL, the lateral far field is single lobed with a divergence angle of only 3°. An ultrahigh brightness value of 156 MW cm{sup −2 }sr{sup −1} is obtained, which marks the brightest QCL to date.

  1. High brightness angled cavity quantum cascade lasers

    NASA Astrophysics Data System (ADS)

    Heydari, D.; Bai, Y.; Bandyopadhyay, N.; Slivken, S.; Razeghi, M.

    2015-03-01

    A quantum cascade laser (QCL) with an output power of 203 W is demonstrated in pulsed mode at 283 K with an angled cavity. The device has a ridge width of 300 μm, a cavity length of 5.8 mm, and a tilt angle of 12°. The back facet is high reflection coated, and the front facet is anti-reflection coated. The emitting wavelength is around 4.8 μm. In distinct contrast to a straight cavity broad area QCL, the lateral far field is single lobed with a divergence angle of only 3°. An ultrahigh brightness value of 156 MW cm-2 sr-1 is obtained, which marks the brightest QCL to date.

  2. Data for phase angle shift with frequency

    PubMed Central

    Paul, T.; Banerjee, D.; Kargupta, K.

    2016-01-01

    Phase angle shift between the current and voltage with frequency has been reported for a single phosphoric acid fuel cell in the cell temperature from 100 °C to 160 °C and the humidifier temperature from 40 °C to 90 °C. An electrochemical workbench is employed to find the shift. The figure of phase angle shift shows a peak in high humidifier temperatures. The peak in phase angle shift directs to lower frequency side with decreasing humidifier temperature. The estimation of electrochemical reaction time is also evaluated in the humidifier temperature zone from 50 °C to 90 °C. PMID:27158655

  3. Positron Emission Mammography with Multiple Angle Acquisition

    SciTech Connect

    Mark F. Smith; Stan Majewski; Raymond R. Raylman

    2002-11-01

    Positron emission mammography (PEM) of F-18 fluorodeoxyglucose (FDG) uptake in breast tumors with dedicated detectors typically has been accomplished with two planar detectors in a fixed position with the breast under compression. The potential use of PEM imaging at two detector positions to guide stereotactic breast biopsy has motivated us to use PEM coincidence data acquired at two or more detector positions together in a single image reconstruction. Multiple angle PEM acquisition and iterative image reconstruction were investigated using point source and compressed breast phantom acquisitions with 5, 9, 12 and 15 mm diameter spheres and a simulated tumor:background activity concentration ratio of 6:1. Image reconstruction was performed with an iterative MLEM algorithm that used coincidence events between any two detector pixels on opposed detector heads at each detector position. This present study compared two acquisition protocols: 2 angle acquisition with detector angular positions of -15 and +15 degrees and 11 angle acquisition with detector positions spaced at 3 degree increments over the range -15 to +15 degrees. Three- dimensional image resolution was assessed for the point source acquisitions, and contrast and signal-to-noise metrics were evaluated for the compressed breast phantom with different simulated tumor sizes. Radial and tangential resolutions were similar for the two protocols, while normal resolution was better for the 2 angle acquisition. Analysis is complicated by the asymmetric point spread functions. Signal- to-noise vs. contrast tradeoffs were better for 11 angle acquisition for the smallest visible 9 mm sphere, while tradeoff results were mixed for the larger and more easily visible 12 mm and 15 mm diameter spheres. Additional study is needed to better understand the performance of limited angle tomography for PEM. PEM tomography experiments with complete angular sampling are planned.

  4. Positron Emission Mammography with Multiple Angle Acquisition

    SciTech Connect

    Mark F. Smith; Stan Majewski; Raymond R. Raylman

    2002-11-01

    Positron emission mammography (PEM) of F-18 fluorodeoxyglucose (FbG) uptake in breast tumors with dedicated detectors typically has been accomplished with two planar detectors in a fixed position with the breast under compression. The potential use of PEM imaging at two detector positions to guide stereotactic breast biopsy has motivated us to use PEM coincidence data acquired at two or more detector positions together in a single image reconstruction. Multiple angle PEM acquisition and iterative image reconstruction were investigated using point source and compressed breast phantom acquisitions with 5, 9, 12 and 15 mm diameter spheres and a simulated tumor:background activity concentration ratio of 6:1. Image reconstruction was performed with an iterative MLEM algorithm that used coincidence events between any two detector pixels on opposed detector heads at each detector position. This present study compared two acquisition protocols: 2 angle acquisition with detector angular positions of -15 and +15 degrees and 11 angle acquisition with detector positions spaced at 3 degree increments over the range -15 to +15 degrees. Three-dimensional image resolution was assessed for the point source acquisitions, and contrast and signal-to-noise metrics were evaluated for the compressed breast phantom with different simulated tumor sizes. Radial and tangential resolutions were similar for the two protocols, while normal resolution was better for the 2 angle acquisition. Analysis is complicated by the asymmetric point spread functions. Signal- to-noise vs. contrast tradeoffs were better for 11 angle acquisition for the smallest visible 9 mm sphere, while tradeoff results were mixed for the larger and more easily visible 12 mm and 15 mm diameter spheres. Additional study is needed to better understand the performance of limited angle tomography for PEM. PEM tomography experiments with complete angular sampling are planned.

  5. Using Digital Technology to See Angles from Different Angles. Part 2: Openings and Turns

    ERIC Educational Resources Information Center

    Host, Erin; Baynham, Emily; McMaster, Heather

    2015-01-01

    Ever wondered how to use technology to teach angles? This article follows on from an earlier article published last year, providing a range of ideas for integrating technology and concrete materials with the teaching of angle concepts. The authors also provide a comprehensive list of free online games and learning objects that can be used to teach…

  6. Understanding Angle and Angle Measure: A Design-Based Research Study Using Context Aware Ubiquitous Learning

    ERIC Educational Resources Information Center

    Crompton, Helen

    2015-01-01

    Mobile technologies are quickly becoming tools found in the educational environment. The researchers in this study use a form of mobile learning to support students in learning about angle concepts. Design-based research is used in this study to develop an empirically-substantiated local instruction theory about students' develop of angle and…

  7. Anterior chamber angle in the exfoliation syndrome.

    PubMed Central

    Wishart, P K; Spaeth, G L; Poryzees, E M

    1985-01-01

    The gonioscopic findings of 76 patients with the exfoliation syndrome were reviewed. A high frequency of narrowness of the anterior chamber (AC) angle was found (32%). 18% had angles considered occludable, and 14% had obvious angle-closure glaucoma as shown by the presence of peripheral anterior synechias (PAS). Increased pigmentation of the posterior trabecular meshwork (PTM) was noted in all cases. When this pigmentation was markedly asymmetrical, unilateral exfoliation with glaucoma was common in the more pigmented eye. In addition heavy angle pigmentation in the absence of exfoliation was noted in the fellow eye of patients with characteristic exfoliated material in the other eye. Increased pigmentation of the PTM may be the earliest detectable sign of the exfoliation syndrome (ES). The clinical significance of our estimating PTM pigmentation at the 12 o'clock position is discussed. In view of the accelerated optic nerve damage associated with the development of glaucoma secondary to ES, routine estimation of the pigmentation of the PTM at 12 o'clock is recommended in the hope of early detection of cases of otherwise inapparent ES. Images PMID:3966996

  8. Incidence angle normalization of radar backscatter data

    Technology Transfer Automated Retrieval System (TEKTRAN)

    NASA’s Soil Moisture Passive Active (SMAP) satellite (~2014) will include a radar system that will provide L-band multi-polarization backscatter at a constant incidence angle of 40º. During the pre-launch phase of the project there is a need for observations that will support the radar-based soil mo...

  9. Spirality: Spiral arm pitch angle measurement

    NASA Astrophysics Data System (ADS)

    Shields, Douglas W.; Boe, Benjamin; Pfountz, Casey; Davis, Benjamin L.; Hartley, Matthew; Pour Imani, Hamed; Slade, Zac; Kennefick, Daniel; Kennefick, Julia

    2015-12-01

    Spirality measures spiral arm pitch angles by fitting galaxy images to spiral templates of known pitch. Written in MATLAB, the code package also includes GenSpiral, which produces FITS images of synthetic spirals, and SpiralArmCount, which uses a one-dimensional Fast Fourier Transform to count the spiral arms of a galaxy after its pitch is determined.

  10. A Method for Measuring a Plane Angle.

    ERIC Educational Resources Information Center

    Roberts, George D.; Roberts, G. Gilbert

    1978-01-01

    Derivation of formulas and example problems for determining the size of a plane angle are given to help in drafting work. The authors state that a small hand calculator will provide greater accuracy in solving these problems than a protractor. (MF)

  11. Crank angle detecting system for engines

    SciTech Connect

    Yuzawa, H.; Nishiyama, M.; Nakamura, K.; Ishigami, K.

    1987-04-14

    A crank angle detecting system is described for a multicylinder engine having at least three cylinders classified as groups, which comprises: (a) a disc connected for rotation with a crankshaft and formed with a first slit group having a large number of slits for detecting crankshaft angular positions and a second slit group having a small number of slits for detecting each predetermined piston stroke of each of at least three cylinders, the slits of the second group having at least three widths which are different from each other; (b) sensing means responsive to the slits on the disc for continuously detecting crankshaft angular positions by sensing the first group of slits and producing crank angle signals corresponding to the slits of the first group and for detecting each predetermined piston stroke of each engine cylinder by sensing the second group of slits and producing piston stroke signals representing the piston strokes, each piston stroke signal having a duration which corresponds to one of the different widths; and (c) means for identifying the piston stroke signals based on the duration thereof by counting crank angle signals occurring during the duration of each piston stroke signal and classifying the piston stroke signals based on the counted crank angle signals.

  12. Ischemia detection from morphological QRS angle changes.

    PubMed

    Romero, Daniel; Martínez, Juan Pablo; Laguna, Pablo; Pueyo, Esther

    2016-07-01

    In this paper, an ischemia detector is presented based on the analysis of QRS-derived angles. The detector has been developed by modeling ischemic effects on the QRS angles as a gradual change with a certain transition time and assuming a Laplacian additive modeling error contaminating the angle series. Both standard and non-standard leads were used for analysis. Non-standard leads were obtained by applying the PCA technique over specific lead subsets to represent different potential locations of the ischemic zone. The performance of the proposed detector was tested over a population of 79 patients undergoing percutaneous coronary intervention in one of the major coronary arteries (LAD (n  =  25), RCA (n  =  16) and LCX (n  =  38)). The best detection performance, obtained for standard ECG leads, was achieved in the LAD group with values of sensitivity and specificity of [Formula: see text], [Formula: see text], followed by the RCA group with [Formula: see text], Sp  =  94.4 and the LCX group with [Formula: see text], [Formula: see text], notably outperforming detection based on the ST series in all cases, with the same detector structure. The timing of the detected ischemic events ranged from 30 s up to 150 s (mean  =  66.8 s) following the start of occlusion. We conclude that changes in the QRS angles can be used to detect acute myocardial ischemia. PMID:27243441

  13. Recent Results on the CKM Angle Alpha

    SciTech Connect

    Mihalyi, A.; /Wisconsin U., Madison

    2005-10-18

    The method to measure the CKM angle {alpha} and the modes sensitive to it are discussed. It is shown that the B {yields} {rho}{rho} decays provide the most stringent constraint on {alpha}, which is found to be {alpha} = 96{sup o} {+-} 10{sup o}(stat) {+-} 4{sup o}(syst){+-} 13{sup o}(penguin).

  14. Sensor Tracks the Sun From Any Angle

    NASA Technical Reports Server (NTRS)

    Birnbaum, M., M.; Bunker, R. L.

    1986-01-01

    Sensor system locates Sun from any angle and generates error signals to point object toward Sun and follow its motion. Sun-sensor system includes three photodetectors, each with separate field of view defined by set of apertures. As equipment rotates about axis, detectors put out time-varying signals processed by external electronics to determine rotation rate and direction to Sun.

  15. Statistical analysis of Contact Angle Hysteresis

    NASA Astrophysics Data System (ADS)

    Janardan, Nachiketa; Panchagnula, Mahesh

    2015-11-01

    We present the results of a new statistical approach to determining Contact Angle Hysteresis (CAH) by studying the nature of the triple line. A statistical distribution of local contact angles on a random three-dimensional drop is used as the basis for this approach. Drops with randomly shaped triple lines but of fixed volumes were deposited on a substrate and their triple line shapes were extracted by imaging. Using a solution developed by Prabhala et al. (Langmuir, 2010), the complete three dimensional shape of the sessile drop was generated. A distribution of the local contact angles for several such drops but of the same liquid-substrate pairs is generated. This distribution is a result of several microscopic advancing and receding processes along the triple line. This distribution is used to yield an approximation of the CAH associated with the substrate. This is then compared with measurements of CAH by means of a liquid infusion-withdrawal experiment. Static measurements are shown to be sufficient to measure quasistatic contact angle hysteresis of a substrate. The approach also points towards the relationship between microscopic triple line contortions and CAH.

  16. Compression failure of angle-ply laminates

    NASA Technical Reports Server (NTRS)

    Peel, Larry D.; Hyer, Michael W.; Shuart, Mark J.

    1991-01-01

    The present work deals with modes and mechanisms of failure in compression of angle-ply laminates. Experimental results were obtained from 42 angle-ply IM7/8551-7a specimens with a lay-up of ((plus or minus theta)/(plus or minus theta)) sub 6s where theta, the off-axis angle, ranged from 0 degrees to 90 degrees. The results showed four failure modes, these modes being a function of off-axis angle. Failure modes include fiber compression, inplane transverse tension, inplane shear, and inplane transverse compression. Excessive interlaminar shear strain was also considered as an important mode of failure. At low off-axis angles, experimentally observed values were considerably lower than published strengths. It was determined that laminate imperfections in the form of layer waviness could be a major factor in reducing compression strength. Previously developed linear buckling and geometrically nonlinear theories were used, with modifications and enhancements, to examine the influence of layer waviness on compression response. The wavy layer is described by a wave amplitude and a wave length. Linear elastic stress-strain response is assumed. The geometrically nonlinear theory, in conjunction with the maximum stress failure criterion, was used to predict compression failure and failure modes for the angle-ply laminates. A range of wave length and amplitudes were used. It was found that for 0 less than or equal to theta less than or equal to 15 degrees failure was most likely due to fiber compression. For 15 degrees less than theta less than or equal to 35 degrees, failure was most likely due to inplane transverse tension. For 35 degrees less than theta less than or equal to 70 degrees, failure was most likely due to inplane shear. For theta less than 70 degrees, failure was most likely due to inplane transverse compression. The fiber compression and transverse tension failure modes depended more heavily on wave length than on wave amplitude. Thus using a single

  17. Probe Without Moving Parts Measures Flow Angle

    NASA Technical Reports Server (NTRS)

    Corda, Stephen; Vachon, M. Jake

    2003-01-01

    The measurement of local flow angle is critical in many fluid-dynamic applications, including the aerodynamic flight testing of new aircraft and flight systems. Flight researchers at NASA Dryden Flight Research Center have recently developed, flight-tested, and patented the force-based flow-angle probe (FLAP), a novel, force-based instrument for the measurement of local flow direction. Containing no moving parts, the FLAP may provide greater simplicity, improved accuracy, and increased measurement access, relative to conventional moving vane-type flow-angle probes. Forces in the FLAP can be measured by various techniques, including those that involve conventional strain gauges (based on electrical resistance) and those that involve more advanced strain gauges (based on optical fibers). A correlation is used to convert force-measurement data to the local flow angle. The use of fiber optics will enable the construction of a miniature FLAP, leading to the possibility of flow measurement in very small or confined regions. This may also enable the tufting of a surface with miniature FLAPs, capable of quantitative flow-angle measurements, similar to attaching yarn tufts for qualitative measurements. The prototype FLAP was a small, aerodynamically shaped, low-aspect-ratio fin about 2 in. (approximately equal to 5 cm) long, 1 in. (approximately equal to 2.5 cm) wide, and 0.125 in. (approximately equal to 0.3 cm) thick (see Figure 1). The prototype FLAP included simple electrical-resistance strain gauges for measuring forces. Four strain gauges were mounted on the FLAP; two on the upper surface and two on the lower surface. The gauges were connected to form a full Wheatstone bridge, configured as a bending bridge. In preparation for a flight test, the prototype FLAP was mounted on the airdata boom of a flight-test fixture (FTF) on the NASA Dryden F-15B flight research airplane.

  18. Development of the Angle Concept by Abstraction from Situated Knowledge.

    ERIC Educational Resources Information Center

    Mitchelmore, Michael C.; White, Paul

    This paper explores a framework for research on the development of the angle concept based on theories of abstraction. The framework suggests that children initially acquire a body of disconnected angle knowledge situated in everyday experiences, group the situations to form angle contexts, and then form an abstract angle concept. The framework is…

  19. The Pluto System At Small Phase Angles

    NASA Astrophysics Data System (ADS)

    Verbiscer, Anne J.; Buie, Marc W.; Binzel, Richard; Ennico, Kimberly; Grundy, William M.; Olkin, Catherine B.; Showalter, Mark Robert; Spencer, John R.; Stern, S. Alan; Weaver, Harold A.; Young, Leslie; New Horizons Science Team

    2016-10-01

    Hubble Space Telescope observations of the Pluto system acquired during the New Horizons encounter epoch (HST Program 13667, M. Buie, PI) span the phase angle range from 0.06 to 1.7 degrees, enabling the measurement and characterization of the opposition effect for Pluto and its satellites at 0.58 microns using HST WFC3/UVIS with the F350LP filter, which has a broadband response and a pivot wavelength of 0.58 microns. At these small phase angles, differences in the opposition effect width and amplitude appear. The small satellites Nix and Hydra both exhibit a very narrow opposition surge, while the considerably larger moon Charon has a broader opposition surge. Microtextural surface properties derived from the shape and magnitude of the opposition surge of each surface contain a record of the collisional history of the system. We combine these small phase angle observations with those made at larger phase angles by the New Horizons Long Range Reconnaissance Imager (LORRI), which also has a broadband response with a pivot wavelength of 0.61 microns, to produce the most complete disk-integrated solar phase curves that we will have for decades to come. Modeling these disk-integrated phase curves generates sets of photometric parameters that will inform spectral modeling of the satellite surfaces as well as terrains on Pluto from spatially resolved New Horizons Ralph Linear Etalon Imaging Spectral Array (LEISA) data from 1.2 to 2.5 microns. Rotationally resolved phase curves of Pluto reveal opposition effects that only appear at phase angles less than 0.1 degree and have widths and amplitudes that are highly dependent on longitude and therefore on Pluto's diverse terrains. The high albedo region informally known as Sputnik Planum dominates the disk-integrated reflectance of Pluto on the New Horizons encounter hemisphere. These results lay the groundwork for observations at true opposition in 2018, when the Pluto system will be observable at phase angles so small that

  20. Spindle cell lipoma-like tumor, solitary fibrous tumor and myofibroblastoma of the breast: a clinico-pathological analysis of 13 cases in favor of a unifying histogenetic concept.

    PubMed

    Magro, Gaetano; Bisceglia, Michele; Michal, Michal; Eusebi, Vincenzo

    2002-03-01

    We reviewed the clinico-pathological features of a series of 13 cases of benign spindle stromal tumors (BSSTs) of the breast relating to a basic common theme consisting of a well-circumscribed proliferation of vimentin+/CD34+/BCL-2+/CD99+ spindly to oval-epithelioid cells, variably arranged in haphazard to short fascicular growth pattern, with interspersed thick or thin collagen bands. Morphological variations included atypical mono- or multi-nucleated cells in five cases and a mature lipomatous tumor component, varying from focal to prominent, in eight cases. Based on morphological and immunophenotypical features, a distinction was made between two main subtypes of these tumors--fibroblastic and myofibroblastic. The former subtype included two cases respectively represented by a typical solitary fibrous tumor (SFT) and a neoplasm labeled "spindle-cell lipoma (SCL)-like tumor", closely reminiscent of soft tissue SCL. Both tumors had cells with fibroblastic-like appearance, haphazardly arranged and immunoreactive for vimentin, CD34, BCL-2, and CD99. The latter subtype, comprised nine cases exhibiting evidence of myofibroblastic differentiation (desmin and alpha-smooth muscle actin) which were classified as myofibroblastomas (MFBs). The remaining two cases were defined as "mixed BSSTs", having typical features of diverse neoplasms, respectively represented by a case of MFB with focal SFT and pleomorphic/SCL-like areas, and SFT with focal MFB-like component. The common basic morpho-immunophenotypical features, the possibility that both fibroblastic and myofibroblastic tumors may contain an additional mature lipomatous component, and the existence of hybrid stages (mixed BSSTs) strongly support the view that such tumors belong to the same category of lesions. We postulate that the precursor of all these neoplasms is the vimentin+/CD34+ cells of the mammary stroma, the well-known inherent plasticity of which to differentiate toward several mesenchymal lines, provides

  1. Measurements of Neutrino Oscillation Angle θ13

    NASA Astrophysics Data System (ADS)

    Kuze, Masahiro

    Neutrinos exhibit an interesting phenomenon called "neutrino oscillation", in which a neutrino changes its flavor after traveling some flight length. Many experiments measured the mixing angles and mass differences, but the angle θ13 had been unmeasured due to its smallness compared to others. During 2011 and 2012, series of new-generation neutrino experiments reported positive results in θ13 search, and its value has been determined to be just below the previous upper limit. The non-zero result of θ13 is a very good news for future of neutrino physics, since it opens a possibility of measuring the CP violation phase in the lepton sector. An introduction to neutrino oscillation and latest experimental results are presented. A detail is put on Double Chooz reactor experiment, in which the author is involved.

  2. Dancing droplets: Contact angle, drag, and confinement

    NASA Astrophysics Data System (ADS)

    Benusiglio, Adrien; Cira, Nate; Prakash, Manu

    2015-11-01

    When deposited on a clean glass slide, a mixture of water and propylene glycol forms a droplet of given contact angle, when both pure liquids spread. (Cira, Benusiglio, Prakash: Nature, 2015). The droplet is stabilized by a gradient of surface tension due to evaporation that induces a Marangoni flow from the border to the apex of the droplets. The apparent contact angle of the droplets depends on both their composition and the external humidity as captured by simple models. These droplets present remarkable properties such as lack of a large pinning force. We discuss the drag on these droplets as a function of various parameters. We show theoretical and experimental results of how various confinement geometries change the vapor gradient and the dynamics of droplet attraction.

  3. Fan Stagger Angle for Dirt Rejection

    NASA Technical Reports Server (NTRS)

    Gallagher, Edward J. (Inventor); Rose, Becky E. (Inventor); Brilliant, Lisa I. (Inventor)

    2015-01-01

    A gas turbine engine includes a spool, a turbine coupled to drive the spool, a propulsor coupled to be rotated about an axis by the turbine through the spool, and a gear assembly coupled between the propulsor and the spool such that rotation of the turbine drives the propulsor at a different speed than the spool. The propulsor includes a hub and a row of propulsor blades that extend from the hub. Each of the propulsor blades has a span between a root at the hub and a tip, and a chord between a leading edge and a trailing edge. The chord forms a stagger angle alpha with the axis, and the stagger angle alpha is less than 15 deg. at a position along the propulsor blade that is within an inboard 20% of the span.

  4. Linkage studies in primary open angle glaucoma

    SciTech Connect

    Avramopoulos, D.; Grigoriadu, M.; Kitsos, G.

    1994-09-01

    Glaucoma is a leading cause of blindness worldwide. The majority of glaucoma is associated with an open, normal appearing anterior chamber angle and is termed primary open angle glaucoma (POAG, MIM 137760). It is characterized by elevated intraocular pressure and onset in middle age or later. A subset of POAG with juvenile onset has recently been linked to chromosome 1q in two families with autosomal dominant inheritance. Eleven pedigrees with autosomal dominant POG (non-juvenile-onset) have been identified in Epirus, Greece. In the present study DNA samples have been collected from 50 individuals from one large pedigree, including 12 affected individuals. Preliminary results of linkage analysis with chromosome 1 microsatellites using the computer program package LINKAGE Version 5.1 showed no linkage with the markers previously linked to juvenile-onset POAG. Further linkage analysis is being pursued, and the results will be presented.

  5. A high sensitive roll angle interferometer

    NASA Astrophysics Data System (ADS)

    Le, Yanfen; Hou, Wenmei; Hu, Kai; Ju, Aisong

    2013-01-01

    A roll angle interferometer with high sensitivity is designed in this paper. Two sets of centrosymmetric beams are used to travel through the measurement and reference arms of the roll angle interferometer which contains two specific optical devices: wedge prism assembly and wedge mirror assembly. The optical path change in both arms caused by roll is converted into phase shift which can be measured by interferometer. Because of the adoption of the centrosymmetric measurement structure, the straightness errors, yaw error and pitch error can be avoided and the dead path is minimized, so that the stability and the accuracy of the measurement can be greatly enhanced. The resolution for the roll measurement is about 0.006″ with the measurement range of ±1°.

  6. Gaia: focus, straylight and basic angle

    NASA Astrophysics Data System (ADS)

    Mora, A.; Biermann, M.; Bombrun, A.; Boyadjian, J.; Chassat, F.; Corberand, P.; Davidson, M.; Doyle, D.; Escolar, D.; Gielesen, W. L. M.; Guilpain, T.; Hernandez, J.; Kirschner, V.; Klioner, S. A.; Koeck, C.; Laine, B.; Lindegren, L.; Serpell, E.; Tatry, P.; Thoral, P.

    2016-07-01

    The Gaia all-sky astrometric survey is challenged by several issues affecting the spacecraft stability. Amongst them, we find the focus evolution, straylight and basic angle variations Contrary to pre-launch expectations, the image quality is continuously evolving, during commissioning and the nominal mission. Payload decontaminations and wavefront sensor assisted refocuses have been carried out to recover optimum performance. An ESA-Airbus DS working group analysed the straylight and basic angle issues and worked on a detailed root cause analysis. In parallel, the Gaia scientists have also analysed the data, most notably comparing the BAM signal to global astrometric solutions, with remarkable agreement. In this contribution, a status review of these issues will be provided, with emphasis on the mitigation schemes and the lessons learned for future space missions where extreme stability is a key requirement.

  7. Comparison between angle interferometer and angle encoder during calibration of autocollimator

    NASA Astrophysics Data System (ADS)

    Huang, Yao; Xue, Zi; Wang, He Yan

    2015-02-01

    An angle interferometer was set up using concept `ratio of two lengths' and an angle encoder was set up using concept `subdivision of full circle (2π rad=360°)' at the National Institute of Metrology, China (NIM). For the analysis of the systematic errors of each device, two autocollimator calibration systems were separately set up based on the angle interferometer and the angle encoder with a similar measuring uncertainty (around 0.1″). An autocollimator was calibrated using two systems in the same measurement range (+/-1000″) and the same measurement step (10″). The systematic errors of each system were found through comparison between their original calibration results. The compensation curves were calculated using the analysis results, and two systems' original calibration results were compensated according to two systems' compensation curves. The maximum difference between the compensated calibration results of two systems was 0.05″ which is lower than measuring uncertainty of each system.

  8. Definition, transformation-formulae and measurements of tipvane angles

    NASA Astrophysics Data System (ADS)

    Bruining, A.

    1987-10-01

    The theoretical background of different angle systems used to define tipvane attitude in 3-D space is outlined. Different Euler equations are used for the various, wind tunnel, towing tank, and full scale tipvane models. The influence of rotor blade flapping angle on tipvane angles is described. The tipvane attitude measuring method is outlined in relationship to the Euler angle system. Side effects on the angle of attack of the tipvane due to rotation, translation, and curving of the tipvane are described.

  9. Shuttle Program. Euler angles, quaternions, and transformation matrices working relationships

    NASA Technical Reports Server (NTRS)

    Henderson, D. M.

    1977-01-01

    A brief mathematical development of the relationship between the Euler angles and the transformation matrix, the quaternion and the transformation matrix, and the Euler angles and the quaternion is presented. The analysis and equations presented apply directly to current space shuttle problems. The twelve three-axis Euler transformation matrices are given as functions of the Euler angles, the equations for the quaternion as a funtion of the Euler angles, and the Euler angles as a function of the transformation matrix elements.

  10. Wireless Orbiter Hang-Angle Inclinometer System

    NASA Technical Reports Server (NTRS)

    Lucena, Angel; Perotti, Jose; Green, Eric; Byon, Jonathan; Burns, Bradley; Mata, Carlos; Randazzo, John; Blalock, Norman

    2011-01-01

    A document describes a system to reliably gather the hang-angle inclination of the orbiter. The system comprises a wireless handheld master station (which contains the main station software) and a wireless remote station (which contains the inclinometer sensors, the RF transceivers, and the remote station software). The remote station is designed to provide redundancy to the system. It includes two RF transceivers, two power-management boards, and four inclinometer sensors.

  11. Experimental Status of the CKM Angle β

    NASA Astrophysics Data System (ADS)

    Hirschauer, James F.

    2009-12-01

    We summarize measurements of the CKM angle β at the B-factories emphasizing a comparison of β measured in the B0→cc¯K(*)0 decay channels and βeff measured in b→qq¯s decay channels, such as B0→ωKS0, B0→η'K0, B0→π0KS0, and B0→S0KS0KS0.

  12. Low angle resistivity anomaly in layered superconductors

    SciTech Connect

    Koshelev, A.E. |; Vinokur, V.M.

    1993-01-01

    The pinning effect of vortex lines by the layered structure (intrinsic pinning) on resistivity of high-T{sub c}, superconductors in the mixed state is investigated by means of perturbation theory. A sharp drop in the resistivity at small angles for which vortex lines are almost aligned with the ab-planes is shown to occur even in a high-temperature region where the pinning potential is reduced by thermal fluctuations.

  13. Measurement of the angle alpha at BABAR

    SciTech Connect

    Perez, A.; /Orsay, LAL

    2009-06-25

    The authors present recent measurements of the CKM angle {alpha} using data collected by the BABAR detector at the PEP-II asymmetric-energy e{sup +}e{sup -} collider at the SLAC National Accelerator Laboratory, operating at the {Upsilon}(4S) resonance. They present constraints on {alpha} from B {yields} {pi}{pi}, B {yields} {rho}{rho} and B {yields} {rho}{pi} decays.

  14. Tool Indicates Contact Angles In Bearing Raceways

    NASA Technical Reports Server (NTRS)

    Akian, Richard A.; Butner, Myles F.

    1995-01-01

    Tool devised for use in measuring contact angles between balls and races in previously operated ball bearings. Used on both inner and outer raceways of bearings having cross-sectional widths between approximately 0.5 and 2.0 in. Consists of integral protractor mounted in vertical plane on bracket equipped with leveling screws and circular level indicator. Protractor includes rotatable indicator needle and set of disks of various sizes to fit various raceway curvatures.

  15. Robust angle-independent blood velocity estimation based on dual-angle plane wave imaging.

    PubMed

    Fadnes, Solveig; Ekroll, Ingvild Kinn; Nyrnes, Siri Ann; Torp, Hans; Lovstakken, Lasse

    2015-10-01

    Two-dimensional blood velocity estimation has shown potential to solve the angle-dependency of conventional ultrasound flow imaging. Clutter filtering, however, remains a major challenge for large beam-to-flow angles, leading to signal drop-outs and corrupted velocity estimates. This work presents and evaluates a compounding speckle tracking (ST) algorithm to obtain robust angle-independent 2-D blood velocity estimates for all beam-to-flow angles. A dual-angle plane wave imaging setup with full parallel receive beamforming is utilized to achieve high-frame-rate speckle tracking estimates from two scan angles, which may be compounded to obtain velocity estimates of increased robustness. The acquisition also allows direct comparison with vector Doppler (VD) imaging. Absolute velocity bias and root-mean-square (RMS) error of the compounding ST estimations were investigated using simulations of a rotating flow phantom with low velocities ranging from 0 to 20 cm/s. In a challenging region where the estimates were influenced by clutter filtering, the bias and RMS error for the compounding ST estimates were 11% and 2 cm/s, a significant reduction compared with conventional single-angle ST (22% and 4 cm/s) and VD (36% and 6 cm/s). The method was also tested in vivo for vascular and neonatal cardiac imaging. In a carotid artery bifurcation, the obtained blood velocity estimates showed that the compounded ST method was less influenced by clutter filtering than conventional ST and VD methods. In the cardiac case, it was observed that ST velocity estimation is more affected by low signal-to-noise (SNR) than VD. However, with sufficient SNR the in vivo results indicated that a more robust angle-independent blood velocity estimator is obtained using compounded speckle tracking compared with conventional ST and VD methods. PMID:26470038

  16. Robust angle-independent blood velocity estimation based on dual-angle plane wave imaging.

    PubMed

    Fadnes, Solveig; Ekroll, Ingvild Kinn; Nyrnes, Siri Ann; Torp, Hans; Lovstakken, Lasse

    2015-10-01

    Two-dimensional blood velocity estimation has shown potential to solve the angle-dependency of conventional ultrasound flow imaging. Clutter filtering, however, remains a major challenge for large beam-to-flow angles, leading to signal drop-outs and corrupted velocity estimates. This work presents and evaluates a compounding speckle tracking (ST) algorithm to obtain robust angle-independent 2-D blood velocity estimates for all beam-to-flow angles. A dual-angle plane wave imaging setup with full parallel receive beamforming is utilized to achieve high-frame-rate speckle tracking estimates from two scan angles, which may be compounded to obtain velocity estimates of increased robustness. The acquisition also allows direct comparison with vector Doppler (VD) imaging. Absolute velocity bias and root-mean-square (RMS) error of the compounding ST estimations were investigated using simulations of a rotating flow phantom with low velocities ranging from 0 to 20 cm/s. In a challenging region where the estimates were influenced by clutter filtering, the bias and RMS error for the compounding ST estimates were 11% and 2 cm/s, a significant reduction compared with conventional single-angle ST (22% and 4 cm/s) and VD (36% and 6 cm/s). The method was also tested in vivo for vascular and neonatal cardiac imaging. In a carotid artery bifurcation, the obtained blood velocity estimates showed that the compounded ST method was less influenced by clutter filtering than conventional ST and VD methods. In the cardiac case, it was observed that ST velocity estimation is more affected by low signal-to-noise (SNR) than VD. However, with sufficient SNR the in vivo results indicated that a more robust angle-independent blood velocity estimator is obtained using compounded speckle tracking compared with conventional ST and VD methods.

  17. Dynamic contact angle cycling homogenizes heterogeneous surfaces.

    PubMed

    Belibel, R; Barbaud, C; Mora, L

    2016-12-01

    In order to reduce restenosis, the necessity to develop the appropriate coating material of metallic stent is a challenge for biomedicine and scientific research over the past decade. Therefore, biodegradable copolymers of poly((R,S)-3,3 dimethylmalic acid) (PDMMLA) were prepared in order to develop a new coating exhibiting different custom groups in its side chain and being able to carry a drug. This material will be in direct contact with cells and blood. It consists of carboxylic acid and hexylic groups used for hydrophilic and hydrophobic character, respectively. The study of this material wettability and dynamic surface properties is of importance due to the influence of the chemistry and the potential motility of these chemical groups on cell adhesion and polymer kinetic hydrolysis. Cassie theory was used for the theoretical correction of contact angles of these chemical heterogeneous surfaces coatings. Dynamic Surface Analysis was used as practical homogenizer of chemical heterogeneous surfaces by cycling during many cycles in water. In this work, we confirmed that, unlike receding contact angle, advancing contact angle is influenced by the difference of only 10% of acidic groups (%A) in side-chain of polymers. It linearly decreases with increasing acidity percentage. Hysteresis (H) is also a sensitive parameter which is discussed in this paper. Finally, we conclude that cycling provides real information, thus avoiding theoretical Cassie correction. H(10)is the most sensible parameter to %A. PMID:27612817

  18. Angle sensitive single photon avalanche diode

    SciTech Connect

    Lee, Changhyuk Johnson, Ben Molnar, Alyosha

    2015-06-08

    An ideal light sensor would provide exact information on intensity, timing, location, and angle of incoming photons. Single photon avalanche diodes (SPADs) provide such desired high (single photon) sensitivity with precise time information and can be implemented at a pixel-scale to form an array to extract spatial information. Furthermore, recent work has demonstrated photodiode-based structures (combined with micro-lenses or diffraction gratings) that are capable of encoding both spatial and angular information of incident light. In this letter, we describe the implementation of such a grating structure on SPADs to realize a pixel-scale angle-sensitive single photon avalanche diode (A-SPAD) built in a standard CMOS process. While the underlying SPAD structure provides high sensitivity, the time information of the two layers of diffraction gratings above offers angle-sensitivity. Such a unique combination of SPAD and diffraction gratings expands the sensing dimensions to pave a path towards lens-less 3-D imaging and light-field time-of-flight imaging.

  19. Off-Angle Iris Correction Methods

    SciTech Connect

    Santos-Villalobos, Hector J; Thompson, Joseph T; Karakaya, Mahmut; Boehnen, Chris Bensing

    2016-01-01

    In many real world iris recognition systems obtaining consistent frontal images is problematic do to inexperienced or uncooperative users, untrained operators, or distracting environments. As a result many collected images are unusable by modern iris matchers. In this chapter we present four methods for correcting off-angle iris images to appear frontal which makes them compatible with existing iris matchers. The methods include an affine correction, a retraced model of the human eye, measured displacements, and a genetic algorithm optimized correction. The affine correction represents a simple way to create an iris image that appears frontal but it does not account for refractive distortions of the cornea. The other method account for refraction. The retraced model simulates the optical properties of the cornea. The other two methods are data driven. The first uses optical flow to measure the displacements of the iris texture when compared to frontal images of the same subject. The second uses a genetic algorithm to learn a mapping that optimizes the Hamming Distance scores between off-angle and frontal images. In this paper we hypothesize that the biological model presented in our earlier work does not adequately account for all variations in eye anatomy and therefore the two data-driven approaches should yield better performance. Results are presented using the commercial VeriEye matcher that show that the genetic algorithm method clearly improves over prior work and makes iris recognition possible up to 50 degrees off-angle.

  20. Small Angle X-Ray Scattering Detector

    DOEpatents

    Hessler, Jan P.

    2004-06-15

    A detector for time-resolved small-angle x-ray scattering includes a nearly constant diameter, evacuated linear tube having an end plate detector with a first fluorescent screen and concentric rings of first fiber optic bundles for low angle scattering detection and an annular detector having a second fluorescent screen and second fiber optic bundles concentrically disposed about the tube for higher angle scattering detection. With the scattering source, i.e., the specimen under investigation, located outside of the evacuated tube on the tube's longitudinal axis, scattered x-rays are detected by the fiber optic bundles, to each of which is coupled a respective photodetector, to provide a measurement resolution, i.e., dq/q, where q is the momentum transferred from an incident x-ray to an x-ray scattering specimen, of 2% over two (2) orders of magnitude in reciprocal space, i.e., q.sub.max /q.sub.min.congruent.100.

  1. Quantifying foot deformation using finite helical angle.

    PubMed

    Pothrat, Claude; Goislard de Monsabert, Benjamin; Vigouroux, Laurent; Viehweger, Elke; Berton, Eric; Rao, Guillaume

    2015-10-15

    Foot intrinsic motion originates from the combination of numerous joint motions giving this segment a high adaptive ability. Existing foot kinematic models are mostly focused on analyzing small scale foot bone to bone motions which require both complex experimental methodology and complex interpretative work to assess the global foot functionality. This study proposes a method to assess the total foot deformation by calculating a helical angle from the relative motions of the rearfoot and the forefoot. This method required a limited number of retro-reflective markers placed on the foot and was tested for five different movements (walking, forefoot impact running, heel impact running, 90° cutting, and 180° U-turn) and 12 participants. Overtime intraclass correlation coefficients were calculated to quantify the helical angle pattern repeatability for each movement. Our results indicated that the method was suitable to identify the different motions as different amplitudes of helical angle were observed according to the flexibility required in each movement. Moreover, the results showed that the repeatability could be used to identify the mastering of each motion as this repeatability was high for well mastered movements. Together with existing methods, this new protocol could be applied to fully assess foot function in sport or clinical contexts.

  2. Angle sensitive single photon avalanche diode

    NASA Astrophysics Data System (ADS)

    Lee, Changhyuk; Johnson, Ben; Molnar, Alyosha

    2015-06-01

    An ideal light sensor would provide exact information on intensity, timing, location, and angle of incoming photons. Single photon avalanche diodes (SPADs) provide such desired high (single photon) sensitivity with precise time information and can be implemented at a pixel-scale to form an array to extract spatial information. Furthermore, recent work has demonstrated photodiode-based structures (combined with micro-lenses or diffraction gratings) that are capable of encoding both spatial and angular information of incident light. In this letter, we describe the implementation of such a grating structure on SPADs to realize a pixel-scale angle-sensitive single photon avalanche diode (A-SPAD) built in a standard CMOS process. While the underlying SPAD structure provides high sensitivity, the time information of the two layers of diffraction gratings above offers angle-sensitivity. Such a unique combination of SPAD and diffraction gratings expands the sensing dimensions to pave a path towards lens-less 3-D imaging and light-field time-of-flight imaging.

  3. Manifold angles, the concept of self-similarity, and angle-enhanced bifurcation diagrams

    PubMed Central

    Beims, Marcus W.; Gallas, Jason A. C.

    2016-01-01

    Chaos and regularity are routinely discriminated by using Lyapunov exponents distilled from the norm of orthogonalized Lyapunov vectors, propagated during the temporal evolution of the dynamics. Such exponents are mean-field-like averages that, for each degree of freedom, squeeze the whole temporal evolution complexity into just a single number. However, Lyapunov vectors also contain a step-by-step record of what exactly happens with the angles between stable and unstable manifolds during the whole evolution, a big-data information permanently erased by repeated orthogonalizations. Here, we study changes of angles between invariant subspaces as observed during temporal evolution of Hénon’s system. Such angles are calculated numerically and analytically and used to characterize self-similarity of a chaotic attractor. In addition, we show how standard tools of dynamical systems may be angle-enhanced by dressing them with informations not difficult to extract. Such angle-enhanced tools reveal unexpected and practical facts that are described in detail. For instance, we present a video showing an angle-enhanced bifurcation diagram that exposes from several perspectives the complex geometrical features underlying the attractors. We believe such findings to be generic for extended classes of systems. PMID:26732416

  4. Perceptions of tilt angles of an agricultural tractor.

    PubMed

    Görücü, Serap; Cavallo, Eugenio; Murphy, Dennis

    2014-01-01

    A tractor stability simulator has been developed to help study tractor operators' perceptions of angles when the simulator is tilted to the side. The simulator is a trailer-mounted tractor cab equipped with hydraulic lift that can tilt the tractor cabin up to 30 degrees. This paper summarizes data from 82 participants who sat in the simulator while it was tilted. Demographic variables, estimates of tilt angles, and measured tilt angles were collected. The effects of age, gender, tractor driving experience, and frequency of operation on the estimated and measured tilt angles were analyzed. The results showed that about 50% of the participants reported estimations of side tilt angles within ±5 degrees of the actual angles, and nearly the same percentage overestimated the actual side tilt angles. Only a small percentage underestimated the angles. Older, more experienced, and male participants set higher limits on the actual angle at which they felt uncomfortable and would not drive. PMID:24417527

  5. Angle amplifier based on multiplexed volume holographic gratings

    NASA Astrophysics Data System (ADS)

    Cao, Liangcai; Zhao, Yifei; He, Qingsheng; Jin, Guofan

    2008-03-01

    Angle amplifier of laser beam scanner is a widely used device in optical systems. Volume holographic optical elements can be applied in the angle amplifier. Compared with the traditional angle amplifier, it has the advantages of high angle resolution, high diffraction efficiency, small size, and high angle magnification and flexible design. Bragg anglewavelength- compensating recording method is introduced. Because of the Bragg compensatory relation between angle and wavelength, this device could be recorded at another wavelength. The design of the angle amplifier recording at the wavelength of 514.2nm for the working wavelength of 632.8nm is described. An optical setup for recording the angle amplifier device is designed and discussed. Experimental results in the photorefractive crystal Fe:LiNbO 3 demonstrate the feasibility of the angle amplifier scheme.

  6. Angle Closure Scoring System (ACSS)-A Scoring System for Stratification of Angle Closure Disease

    PubMed Central

    Rao, Aparna; Padhy, Debananda; Sarangi, Sarada; Das, Gopinath

    2016-01-01

    Purpose To evaluate the angle closure scoring system (ACSS) for stratifying primary angle course disease. Methods This observational cross sectional institutional study included patients with primary open angle glaucoma suspects (n = 21) and primary angle closure disease (primary angle closure, PAC, n = 63 and primary angle course glaucoma, PACG, n = 58 (defined by International society of Geographical and Epidemiological Ophthalmology, ISGEO). Two independent examiners blinded to clinical details, graded good quality pre-laser goniophotographs of the patients incorporating quadrants of peripheral anterior synechieae (PAS), non-visibility of posterior trabecular meshwork (PTM) and blotchy pigments (ranging from 1–4 quadrants), iris configuration, angle recess (sum of above depicting ACSSg) and lens thickness/axial length ratio (LT/AL), cup disc ratio and baseline intraocular pressure (IOP) to give total score (ACSSt). Result There were significant differences in ACSSg scores within the same ISGEO stage of PAC and PACG between eyes that required nil or >1medicines after laser iridotomy, p<0.001. The ACSSg was associated with need for >1 medicines in both PAC and PACG eyes, p<0.001. An ACSSg score>12 and 14 in PAC (odds ratio = 2.7(95% CI-1.7–5.9) and PACG (Odds ratio = 1.6(95%CI-1.19–2.2) predicted need for single medicines while ACSSg scores >14 and 19 predicted need for ≥2 medicines in PAC and PACG eyes, respectively. The LT/Al ratio, IOP score or cup disc score did not influence the need for medical treatment independently. Conclusion The ACSS can be a useful clinical adjunct to the ISGEO system to predict need for medicines and prognosticate each stage more accurately. PMID:27788183

  7. Determining surface wave arrival angle anomalies

    NASA Astrophysics Data System (ADS)

    Larson, Erik W. F.; Ekström, Göran

    2002-06-01

    A new method for measuring arrival angles of teleseismic Love and Rayleigh waves is developed. The new method utilizes estimates of surface wave dispersion to create a phase-matched filter to isolate the Love or Rayleigh wave in three-component recordings. The polarization of the filtered wave group is determined in the time domain by application of a variation of the complex polarization method of Vidale [1986]. Orientation, linearity, and ellipticity of particle motion are estimated in several frequency bands to determine the frequency-dependent polarization. The method employs an iterative scheme, by which a predicted Love wave, based on the estimated dispersion and polarization, is subtracted from the three-component data prior to the estimation of Rayleigh wave polarization, and vice versa. The method is applied to an extensive set of Global Seismographic Network data covering the years 1989-1998. Between 4244 and 15,075 measurements are collected for fundamental mode Love and Rayleigh waves at nine different periods (37 to 150 s). Measurement uncertainties are estimated using the statistics of observations for pairwise similar paths and are generally of the order of 15-50% of the total signal, depending on the period and the wave type. Large and azimuthally invariant angle anomalies are documented for several stations and are consistent with misorientation of the horizontal seismometers. Two schemes are employed to determine the misorientations: (1) an azimuthally weighted average at each station, and (2) a joint inversion for seismometer misorientation and globally heterogeneous phase velocities. The determined corrections are robust and correlate well with those reported in earlier studies. Azimuthally varying arrival angle anomalies are shown to agree qualitatively with predictions of wave refraction calculated for recent phase velocity maps, which explain up to 30% of the variance in the new measurements.

  8. Junctional angle of a bihanded helix.

    PubMed

    Yang, Jing; Wolgemuth, Charles W; Huber, Greg

    2014-10-01

    Helical filaments having sections of reversed chirality are common phenomena in the biological realm. The apparent angle between the two sections of opposite handedness provides information about the geometry and elasticity of the junctional region. In this paper, the governing differential equations for the local helical axis are developed, and asymptotic solutions of the governing equations are solved by perturbation theory. The asymptotic solutions are compared with the corresponding numerical solutions, and the relative error at second order is found to be less than 1.5% over a range of biologically relevant curvature and torsion values from 0 to 1/2 in dimensionless units.

  9. Narrow-angle Astrometry with SUSI

    NASA Astrophysics Data System (ADS)

    Kok, Y.; Ireland, M. J.; Robertson, J. G.; Tuthill, P. G.; Warrington, B. A.; Tango, W. J.

    2014-09-01

    SUSI (Sydney University Stellar Interferometer) is currently being fitted with a 2nd beam combiner, MUSCA (Micro-arcsecond University of Sydney Companion Astrometry), for the purpose of narrow-angle astrometry. With an aim to achieve ˜10 micro-arcseconds of angular resolution at its best, MUSCA allows SUSI to search for planets around bright binary stars, which are its primary targets. While the first beam combiner, PAVO (Precision Astronomical Visible Observations), is used to track stellar fringes during an observation, MUSCA will be used to measure separations of binary stars. MUSCA is a Michelson interferometer and its setup at SUSI will be described in this poster.

  10. Euler angles as torsional flat spaces

    NASA Astrophysics Data System (ADS)

    Trejo-Mandujano, Hector A.

    In this work we use general tensor calculus to compare the geodesic equation of motion and Newton's first law for force-free classical systems that are described by an arbitrary number of generalized coordinates in spaces with and without torsion. We choose as objects of study the flat torsional Euler angle metric spaces for rigid rotators. We tested the equivalence of the two motion equations using computational software that allowed algebraic manipulation. The main result is that the equivalence only holds for torsion-free spaces, and for isotropic force-free rotators. We present analytical calculations for the isotropic case and computational results for the general case.

  11. Magic angle spinning NMR of viruses.

    PubMed

    Quinn, Caitlin M; Lu, Manman; Suiter, Christopher L; Hou, Guangjin; Zhang, Huilan; Polenova, Tatyana

    2015-04-01

    Viruses, relatively simple pathogens, are able to replicate in many living organisms and to adapt to various environments. Conventional atomic-resolution structural biology techniques, X-ray crystallography and solution NMR spectroscopy provided abundant information on the structures of individual proteins and nucleic acids comprising viruses; however, viral assemblies are not amenable to analysis by these techniques because of their large size, insolubility, and inherent lack of long-range order. In this article, we review the recent advances in magic angle spinning NMR spectroscopy that enabled atomic-resolution analysis of structure and dynamics of large viral systems and give examples of several exciting case studies. PMID:25919197

  12. Magic Angle Spinning NMR of Viruses

    PubMed Central

    Quinn, Caitlin; Lu, Manman; Suiter, Christopher L.; Hou, Guangjin; Zhang, Huilan; Polenova, Tatyana

    2015-01-01

    Viruses, relatively simple pathogens, are able to replicate in many living organisms and to adapt to various environments. Conventional atomic-resolution structural biology techniques, X-ray crystallography and solution NMR spectroscopy provided abundant information on the structures of individual proteins and nucleic acids comprising viruses; however, viral assemblies are not amenable to analysis by these techniques because of their large size, insolubility, and inherent lack of long-range order. In this article, we review the recent advances in magic angle spinning NMR spectroscopy that enabled atomic-resolution analysis of structure and dynamics of large viral systems and give examples of several exciting case studies. PMID:25919197

  13. Angle parameter changes of phacoemulsification and combined phacotrabeculectomy for acute primary angle closure

    PubMed Central

    Li, Shi-Wei; Chen, Yan; Wu, Qiang; Lu, Bin; Wang, Wen-Qing; Fang, Jian

    2015-01-01

    AIM To evaluate the difference in angle parameters and clinical outcome following phacoemulsification and combined phacotrabeculectomy in patients with acute primary angle closure (APAC) using ultrasound biomicroscopy (UBM). METHODS Patients (n=23, 31 eyes) were randomized to receive phacoemulsification or combined phacotrabeculectomy (n=24, 31 eyes). Best-corrected visual acuity (BCVA), intraocular pressure (IOP), the main complications following surgery, and indentation gonioscopy and angle parameters measured using UBM were documented preoperatively and postoperatively. RESULTS The improvement in BCVA in the phacoemulsification group was significantly greater than in the combined group (P<0.05). IOP in the phacoemulsification group was slightly higher than in the combined group following 1wk of follow-up (P<0.05), whereas there was no significant difference between the two groups at the latter follow-up (P>0.05). Phacoemulsification alone resulted in a slight increase in the trabecular ciliary processes distance compared with the combined surgery (P<0.05), whereas the other angle parameters showed no significant difference between the groups. Complications in combined group were greater than phacoemulsification only group. CONCLUSION Both surgeries effectively opened the drainage angle and deepened the anterior chamber, and IOP was well controlled postoperatively. However, phacoemulsification showed better efficacy in improving visual function and showed reduced complications following surgery. PMID:26309873

  14. Pitch-angle scattering in magnetostatic turbulence. II. Analytical considerations and pitch-angle isotropization

    NASA Astrophysics Data System (ADS)

    Tautz, R. C.

    2013-10-01

    Aims: The process of pitch-angle isotropization is important for many applications ranging from diffusive shock acceleration to large-scale cosmic-ray transport. Here, the basic analytical description is revisited on the basis of recent simulation results. Methods: Both an analytical and a numerical investigation were undertaken of the Fokker-Planck equation for pitch-angle scattering. Additional test-particle simulations obtained with the help of a Monte-Carlo code were used to verify the conclusions. Results: It is shown that the usual definition of the pitch-angle Fokker-Planck coefficient via the mean-square displacement is flawed. The reason can be traced back to the assumption of homogeneity in time which does not hold for pitch-angle scattering. Conclusions: Calculating the mean free path via the Fokker-Planck coefficient has often proven to give an accurate description. For numerical purposes, accordingly, it is the definition that has to be exchanged in favor of the pitch-angle correlation function.

  15. Study on self-calibration angle encoder using simulation method

    NASA Astrophysics Data System (ADS)

    Wang, Yan; Xue, Zi; Huang, Yao; Wang, Xiaona

    2016-01-01

    The angle measurement technology is very important in precision manufacture, optical industry, aerospace, aviation and navigation, etc. Further, the angle encoder, which uses concept `subdivision of full circle (2π rad=360°)' and transforms the angle into number of electronic pulse, is the most common instrument for angle measurement. To improve the accuracy of the angle encoder, a novel self-calibration method was proposed that enables the angle encoder to calibrate itself without angle reference. An angle deviation curve among 0° to 360° was simulated with equal weights Fourier components for the study of the self-calibration method. In addition, a self-calibration algorithm was used in the process of this deviation curve. The simulation result shows the relationship between the arrangement of multi-reading heads and the Fourier components distribution of angle encoder deviation curve. Besides, an actual self-calibration angle encoder was calibrated by polygon angle standard in national institute of metrology, China. The experiment result indicates the actual self-calibration effect on the Fourier components distribution of angle encoder deviation curve. In the end, the comparison, which is between the simulation self-calibration result and the experiment self-calibration result, reflects good consistency and proves the reliability of the self-calibration angle encoder.

  16. Metric analysis of basal sphenoid angle in adult human skulls

    PubMed Central

    Netto, Dante Simionato; Nascimento, Sergio Ricardo Rios; Ruiz, Cristiane Regina

    2014-01-01

    Objective To analyze the variations in the angle basal sphenoid skulls of adult humans and their relationship to sex, age, ethnicity and cranial index. Methods The angles were measured in 160 skulls belonging to the Museum of the Universidade Federal de São Paulo Department of Morphology. We use two flexible rules and a goniometer, having as reference points for the first rule the posterior end of the ethmoidal crest and dorsum of the sella turcica, and for the second rule the anterior margin of the foramen magnum and clivus, measuring the angle at the intersection of two. Results The average angle was 115.41°, with no statistical correlation between the value of the angle and sex or age. A statistical correlation was noted between the value of the angle and ethnicity, and between the angle and the horizontal cranial index. Conclusions The distribution of the angle basal sphenoid was the same in sex, and there was correlation between the angle and ethnicity, being the proportion of non-white individuals with an angle >125° significantly higher than that of whites with an angle >125°. There was correlation between the angle and the cranial index, because skulls with higher cranial index tend to have higher basiesfenoidal angle too. PMID:25295452

  17. Wide-angle imaging system with fiberoptic components providing angle-dependent virtual material stops

    NASA Technical Reports Server (NTRS)

    Vaughan, Arthur H. (Inventor)

    1993-01-01

    A strip imaging wide angle optical system is provided. The optical system is provided with a 'virtual' material stop to avoid aberrational effects inherent in wide angle optical systems. The optical system includes a spherical mirror section for receiving light from a 180 deg strip or arc of a target image. Light received by the spherical mirror section is reflected to a frustoconical mirror section for subsequent rereflection to a row of optical fibers. Each optical fiber transmits a portion of the received light to a detector. The optical system exploits the narrow cone of acceptance associated with optical fibers to substantially eliminate vignetting effects inherent in wide angle systems. Further, the optical system exploits the narrow cone of acceptance of the optical fibers to substantially limit spherical aberration. The optical system is ideally suited for any application wherein a 180 deg strip image need be detected, and is particularly well adapted for use in hostile environments such as in planetary exploration.

  18. Hidden Topological Angles in Path Integrals

    NASA Astrophysics Data System (ADS)

    Behtash, Alireza; Sulejmanpasic, Tin; Schäfer, Thomas; Ünsal, Mithat

    2015-07-01

    We demonstrate the existence of hidden topological angles (HTAs) in a large class of quantum field theories and quantum mechanical systems. HTAs are distinct from theta parameters in the Lagrangian. They arise as invariant angles associated with saddle points of the complexified path integral and their descent manifolds (Lefschetz thimbles). Physical effects of HTAs become most transparent upon analytic continuation in nf to a noninteger number of flavors, reducing in the integer nf limit to a Z2 valued phase difference between dominant saddles. In N =1 super Yang-Mills theory we demonstrate the microscopic mechanism for the vanishing of the gluon condensate. The same effect leads to an anomalously small condensate in a QCD-like S U (N ) gauge theory with fermions in the two-index representation. The basic phenomenon is that, contrary to folklore, the gluon condensate can receive both positive and negative contributions in a semiclassical expansion. In quantum mechanics, a HTA leads to a difference in semiclassical expansion of integer and half-integer spin particles.

  19. Weight factors for limited angle photoacoustic tomography

    PubMed Central

    Paltauf, G; Nuster, R; Burgholzer, P

    2011-01-01

    Photoacoustic tomography (PAT) is based on the generation of ultrasound waves by heating an object with short light pulses. A three-dimensional image of the distribution of absorbed energy within the object is reconstructed from signals measured around the object with either point like or extended, linear sensors. Limited angle artefacts arise when the curve or surface connecting neighbouring detectors is not closed around the object. For this case there exists a “detection region” in which all boundaries of an object are visible in the reconstruction. All straight lines passing through each point in this region intersect the detection curve or surface at least once. Although for these points an accurate reconstruction is possible, direct back projection leads to artefacts when some of the straight lines intersect the detection surface twice and others just once. In this work special weight functions for direct, non iterative back projection are presented that reduce these kinds of artefacts. A clear improvement of image quality is shown in simulations for three-dimensional (3D) imaging with point detectors and for two-dimensional (2D) imaging using line detectors compared to reconstruction without weight factors. For the 2D case also an experiment is shown. The presented weight factors make commonly used back projection formulas suitable for more accurate reconstruction of the initial pressure distribution in cases where the detection aperture only covers a limited angle and the region of interest lies within the detection region. PMID:19430108

  20. Diphotons, new vacuum angles, and strong CP

    DOE PAGES

    Draper, Patrick; McKeen, David

    2016-04-20

    The Standard Model contains a well-understood, natural, spin-0 diphoton resonance: the π0. Numerous studies have pointed out that the hint of a new diphoton resonance at 750 GeV could be a pion analog, identified with the pseudo-Nambu-Goldstone boson of a chiral symmetry spontaneously broken by new strong dynamics at the TeV scale. These “hypercolor” models are generically expected to violate parity through a topological angle θ~. We discuss the physics of θ~ and its impact on the phenomenology of the new sector. We also describe some of the theoretical implications of a nonzero θ~. In particular, θ~ can generate anmore » O(1) threshold correction to the QCD vacuum angle θ near the TeV scale, sharply constraining ultraviolet solutions to the strong CP problem. Furthermore, finding that θ~ is small may be interpreted as evidence in favor of UV solutions to strong CP, particularly those based on spontaneously broken P or CP symmetries.« less

  1. Active limited-angle tomographic phase microscope.

    PubMed

    Kus, Arkadiusz; Krauze, Wojciech; Kujawinska, Malgorzata

    2015-01-01

    We demonstrate an active, holographic tomography system, working with limited angle of projections, realized by optical-only, diffraction-based beam steering. The system created for this purpose is a Mach–Zehnder interferometer modified to serve as a digital holographic microscope with a high numerical aperture illumination module and a spatial light modulator (SLM). Such a solution is fast and robust. Apart from providing an elegant solution to viewing angle shifting, it also adds new capabilities of the holographic microscope system. SLM, being an active optical element, allows wavefront correction in order to improve measurement accuracy. Integrated phase data captured with different illumination scenarios within a highly limited angular range are processed by a new tomographic reconstruction algorithm based on the compressed sensing technique: total variation minimization, which is applied here to reconstruct nonpiecewise constant samples. Finally, the accuracy of full measurement and the proposed processing path is tested for a calibrated three-dimensional micro-object as well as a biological object--C2C12 myoblast cell.

  2. Wave-angle control of delta evolution

    NASA Astrophysics Data System (ADS)

    Ashton, Andrew D.; Giosan, Liviu

    2011-07-01

    Wave-influenced deltas, with large-scale arcuate shapes and demarcated beach ridge complexes, often display an asymmetrical form about their river channel. Here, we use a numerical model to demonstrate that the angles from which waves approach a delta can have a first-order influence upon its plan-view morphologic evolution and sedimentary architecture. The directional spread of incoming waves plays a dominant role over fluvial sediment discharge in controlling the width of an active delta lobe, which in turn affects the characteristic rates of delta progradation. Oblique wave approach (and a consequent net alongshore sediment transport) can lead to the development of morphologic asymmetry about the river in a delta's plan-view form. This plan-form asymmetry can include the development of discrete breaks in shoreline orientation and the appearance of self-organized features arising from shoreline instability along the downdrift delta flank, such as spits and migrating shoreline sand waves—features observed on natural deltas. Somewhat surprisingly, waves approaching preferentially from one direction tend to increase sediment deposition updrift of the river. This ‘morphodynamic groin effect’ occurs when the delta's plan-form aspect ratio is sufficiently large such that the orientation of the shoreline on the downdrift flank is rotated past the angle of maximum alongshore sediment transport, resulting in preferential redirection of fluvial sediment updrift of the river mouth.

  3. Reactor mixing angle from hybrid neutrino masses

    NASA Astrophysics Data System (ADS)

    Sierra, D. Aristizabal; de Medeiros Varzielas, I.

    2014-07-01

    In terms of its eigenvector decomposition, the neutrino mass matrix (in the basis where the charged lepton mass matrix is diagonal) can be understood as originating from a tribimaximal dominant structure with small deviations, as demanded by data. If neutrino masses originate from at least two different mechanisms, referred to as "hybrid neutrino masses", the experimentally observed structure naturally emerges provided one mechanism accounts for the dominant tribimaximal structure while the other is responsible for the deviations. We demonstrate the feasibility of this picture in a fairly model-independent way by using lepton-number-violating effective operators, whose structure we assume becomes dictated by an underlying A 4 flavor symmetry. We show that if a second mechanism is at work, the requirement of generating a reactor angle within its experimental range always fixes the solar and atmospheric angles in agreement with data, in contrast to the case where the deviations are induced by next-to-leading order effective operators. We prove this idea is viable by constructing an A 4-based ultraviolet completion, where the dominant tribimaximal structure arises from the type-I seesaw while the subleading contribution is determined by either type-II or type-III seesaw driven by a non-trivial A 4 singlet (minimal hybrid model). After finding general criteria, we identify all the N symmetries capable of producing such A 4-based minimal hybrid models.

  4. Large Angle Transient Dynamics (LATDYN) user's manual

    NASA Technical Reports Server (NTRS)

    Abrahamson, A. Louis; Chang, Che-Wei; Powell, Michael G.; Wu, Shih-Chin; Bingel, Bradford D.; Theophilos, Paula M.

    1991-01-01

    A computer code for modeling the large angle transient dynamics (LATDYN) of structures was developed to investigate techniques for analyzing flexible deformation and control/structure interaction problems associated with large angular motions of spacecraft. This type of analysis is beyond the routine capability of conventional analytical tools without simplifying assumptions. In some instances, the motion may be sufficiently slow and the spacecraft (or component) sufficiently rigid to simplify analyses of dynamics and controls by making pseudo-static and/or rigid body assumptions. The LATDYN introduces a new approach to the problem by combining finite element structural analysis, multi-body dynamics, and control system analysis in a single tool. It includes a type of finite element that can deform and rotate through large angles at the same time, and which can be connected to other finite elements either rigidly or through mechanical joints. The LATDYN also provides symbolic capabilities for modeling control systems which are interfaced directly with the finite element structural model. Thus, the nonlinear equations representing the structural model are integrated along with the equations representing sensors, processing, and controls as a coupled system.

  5. Tilt angle control of nanocolumns grown by glancing angle sputtering at variable argon pressures

    SciTech Connect

    Garcia-Martin, J. M.; Cebollada, A.; Alvarez, R.; Romero-Gomez, P.; Palmero, A.

    2010-10-25

    We show that the tilt angle of nanostructures obtained by glancing angle sputtering is finely tuned by selecting the adequate argon pressure. At low pressures, a ballistic deposition regime dominates, yielding high directional atoms that form tilted nanocolumns. High pressures lead to a diffusive regime which gives rise to vertical columnar growth. Monte Carlo simulations reproduce the experimental results indicating that the loss of directionality of the sputtered particles in the gas phase, together with the self-shadowing mechanism at the surface, are the main processes responsible for the development of the columns.

  6. Meningioma of the Posterior Skull Base

    PubMed Central

    Biggs, Michael Thomas; Fagan, Paul A.; Sheehy, John P.R.; Bentivoglio, Peter J.; Doust, Bruce D.; Tonkin, John

    1991-01-01

    Combined intratemporal and cerebellopontine angle meningiomas are rejatively rare. There are unsolved problems with the stability of the skull and spine and the lower cranial nerves and there is a marked tendency for the tumor to involve the spinal cord. This article reports on five cases of combined intratemporal and cerebellopontine angle meningiomas. ImagesFigure 1p44-bFigure 2Figure 3Figure 4Figure 5 PMID:17170820

  7. 14 CFR 23.1387 - Position light system dihedral angles.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... described in this section. (b) Dihedral angle L (left) is formed by two intersecting vertical planes, the... formed by two intersecting vertical planes, the first parallel to the longitudinal axis of the airplane... longitudinal axis. (d) Dihedral angle A (aft) is formed by two intersecting vertical planes making angles of...

  8. 14 CFR 23.1387 - Position light system dihedral angles.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... described in this section. (b) Dihedral angle L (left) is formed by two intersecting vertical planes, the... formed by two intersecting vertical planes, the first parallel to the longitudinal axis of the airplane... longitudinal axis. (d) Dihedral angle A (aft) is formed by two intersecting vertical planes making angles of...

  9. 14 CFR 27.1387 - Position light system dihedral angles.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... this section. (b) Dihedral angle L (left) is formed by two intersecting vertical planes, the first... two intersecting vertical planes, the first parallel to the longitudinal axis of the rotorcraft, and... longitudinal axis. (d) Dihedral angle A (aft) is formed by two intersecting vertical planes making angles of...

  10. 14 CFR 29.1387 - Position light system dihedral angles.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... described in this section. (b) Dihedral angle L (left) is formed by two intersecting vertical planes, the... formed by two intersecting vertical planes, the first parallel to the longitudinal axis of the rotorcraft... longitudinal axis. (d) Dihedral angle A (aft) is formed by two intersecting vertical planes making angles of...

  11. 14 CFR 27.1387 - Position light system dihedral angles.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... this section. (b) Dihedral angle L (left) is formed by two intersecting vertical planes, the first... two intersecting vertical planes, the first parallel to the longitudinal axis of the rotorcraft, and... longitudinal axis. (d) Dihedral angle A (aft) is formed by two intersecting vertical planes making angles of...

  12. 14 CFR 25.1387 - Position light system dihedral angles.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... this section. (b) Dihedral angle L (left) is formed by two intersecting vertical planes, the first... two intersecting vertical planes, the first parallel to the longitudinal axis of the airplane, and the... axis. (d) Dihedral angle A (aft) is formed by two intersecting vertical planes making angles of...

  13. 14 CFR 27.1387 - Position light system dihedral angles.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... this section. (b) Dihedral angle L (left) is formed by two intersecting vertical planes, the first... two intersecting vertical planes, the first parallel to the longitudinal axis of the rotorcraft, and... longitudinal axis. (d) Dihedral angle A (aft) is formed by two intersecting vertical planes making angles of...

  14. 14 CFR 25.1387 - Position light system dihedral angles.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... this section. (b) Dihedral angle L (left) is formed by two intersecting vertical planes, the first... two intersecting vertical planes, the first parallel to the longitudinal axis of the airplane, and the... axis. (d) Dihedral angle A (aft) is formed by two intersecting vertical planes making angles of...

  15. 14 CFR 25.1387 - Position light system dihedral angles.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... this section. (b) Dihedral angle L (left) is formed by two intersecting vertical planes, the first... two intersecting vertical planes, the first parallel to the longitudinal axis of the airplane, and the... axis. (d) Dihedral angle A (aft) is formed by two intersecting vertical planes making angles of...

  16. 14 CFR 23.1387 - Position light system dihedral angles.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... described in this section. (b) Dihedral angle L (left) is formed by two intersecting vertical planes, the... formed by two intersecting vertical planes, the first parallel to the longitudinal axis of the airplane... longitudinal axis. (d) Dihedral angle A (aft) is formed by two intersecting vertical planes making angles of...

  17. 14 CFR 29.1387 - Position light system dihedral angles.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... described in this section. (b) Dihedral angle L (left) is formed by two intersecting vertical planes, the... formed by two intersecting vertical planes, the first parallel to the longitudinal axis of the rotorcraft... longitudinal axis. (d) Dihedral angle A (aft) is formed by two intersecting vertical planes making angles of...

  18. 14 CFR 29.1387 - Position light system dihedral angles.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... described in this section. (b) Dihedral angle L (left) is formed by two intersecting vertical planes, the... formed by two intersecting vertical planes, the first parallel to the longitudinal axis of the rotorcraft... longitudinal axis. (d) Dihedral angle A (aft) is formed by two intersecting vertical planes making angles of...

  19. Spray coating of superhydrophobic and angle-independent coloured films.

    PubMed

    Ge, Dengteng; Yang, Lili; Wu, Gaoxiang; Yang, Shu

    2014-03-01

    Angle-independent coloured films with superhydrophobicity were fabricated from quasi-amorphous arrays of monodispersed fluorinated silica nanoparticles via one-step spray coating. The film exhibited a high contact angle (>150°) and a low roll-off angle (~2°) and the colour could be tuned to blue, green and moccasin by varying the size of the nanoparticles.

  20. Turn vs. Shape: Teachers Cope with Incompatible Perspectives on Angle

    ERIC Educational Resources Information Center

    Kontorovich, Igor'; Zazkis, Rina

    2016-01-01

    This study is concerned with tensions between the two different perspectives on the concept of angle: angle as a static shape and angle as a dynamic turn. The goal of the study is to explore how teachers cope with these tensions. We analyze scripts of 16 in-service secondary mathematics teachers, which feature a dialogue between a teacher and…

  1. The Effect of Training on Accuracy of Angle Estimation.

    ERIC Educational Resources Information Center

    Waller, T. Gary; Wright, Robert H.

    This report describes a study to determine the effect of training on accuracy in estimating angles. The study was part of a research program directed toward improving navigation techniques for low-level flight in Army aircraft and was made to assess the feasibility of visually estimating angles on a map in order to determine angles of drift.…

  2. Lag Angle Compensation in a Space Borne Scanning Lidar

    NASA Technical Reports Server (NTRS)

    Wissinger, A. B.

    1992-01-01

    The so-called 'lag angle' is inherent in any spaceborne scanning lidar system. It is also important in systems where the scanning causes a significant pointing error during the laser interrogating pulse echo time. In a heterodyne lidar system, the lag angle, if uncompensated, will significantly reduce the signal-to-noise ratio. An investigation of lag angle is presented.

  3. Impedance Scaling for Small Angle Transitions

    SciTech Connect

    Stupakov, G.; Bane, Karl; Zagorodnov, I.; /DESY

    2010-10-27

    Based on the parabolic equation approach to Maxwell's equations we have derived scaling properties of the high frequency impedance/short bunch wakefields of structures. For the special case of small angle transitions we have shown the scaling properties are valid for all frequencies. Using these scaling properties one can greatly reduce the calculation time of the wakefield/impedance of long, small angle, beam pipe transitions, like one often finds in insertion regions of storage rings. We have tested the scaling with wakefield simulations of 2D and 3D models of such transitions, and found that the scaling works well. In modern ring-based light sources one often finds insertion devices having extremely small vertical apertures (on the order of millimeters) to allow for maximal undulator fields reaching the beam. Such insertion devices require that there be beam pipe transitions from these small apertures to the larger cross-sections (normally on the order of centimeters) found in the rest of the ring. The fact that there may be many such transitions, and that these transitions introduce beam pipe discontinuities very close to the beam path, means that their impedance will be large and, in fact, may dominate the impedance budget of the entire ring. To reduce their impact on impedance, the transitions are normally tapered gradually over a long distance. The accurate calculation of the impedance or wakefield of these long transitions, which are typically 3D objects (i.e. they do not have cylindrical symmetry), can be quite a challenging numerical task. In this report we present a method of obtaining the impedance of a long, small angle transition from the calculation of a scaled, shorter one. Normally, the actual calculation is obtained from a time domain simulation of the wakefield in the structure, where the impedance can be obtained by performing a Fourier transform. We shall see that the scaled calculation reduces the computer time and memory requirements

  4. Distinguishing features of shallow angle plunging jets

    NASA Astrophysics Data System (ADS)

    Deshpande, Suraj S.; Trujillo, Mario F.

    2013-08-01

    Numerical simulations employing an algebraic volume-of-fluid methodology are used to study the air entrainment characteristics of a water jet plunging into a quiescent water pool at angles ranging from θ = 10° to θ = 90° measured from the horizontal. Our previous study of shallow angled jets [S. S. Deshpande, M. F. Trujillo, X. Wu, and G. L. Chahine, "Computational and experimental characterization of a liquid jet plunging into a quiescent pool at shallow inclination," Int. J. Heat Fluid Flow 34, 1-14 (2012)], 10.1016/j.ijheatfluidflow.2012.01.011 revealed the existence of a clearly discernible frequency of ingestion of large air cavities. This is in contrast with chaotic entrainment of small air pockets reported in the literature in case of steeper or vertically plunging jets. In the present work, the differences are addressed by first quantifying the cavity size and entrained air volumes for different impingement angles. The results support the expected trend - reduction in cavity size (D43) as θ is increased. Time histories of cavity volumes in the vicinity of the impingement region confirm the visual observations pertaining to a near-periodic ingestion of large air volumes for shallow jets (10°, 12°), and also show that such cavities are not formed for steep or vertical jets. Each large cavity (defined as Dc/Dj ≳ 3) exists in close association with a stagnation point flow. A local mass and momentum balance shows that the high stagnation pressure causes a radial redirection of the jet, resulting in a flow that resembles the initial impact of a jet on the pool. In fact, for these large cavities, their speed matches closely Uimpact/2, which coincides with initial cavity propagation for sufficiently high Froude numbers. Furthermore, it is shown that the approximate periodicity of air entrainment scales linearly with Froude number. This finding is confirmed by a number of simulations at θ = 12°. Qualitatively, for steeper jets, such large stagnation

  5. Superwide-angle acoustic propagations above the critical angles of the Snell law in liquid—solid superlattice

    NASA Astrophysics Data System (ADS)

    Zhang, Sai; Zhang, Yu; Gao, Xiao-Wei

    2014-12-01

    In this paper, superwide-angle acoustic propagations above the critical angles of the Snell law in liquid—solid superlattice are investigated. Incident waves above the critical angles of the Snell law usually inevitably induce total reflection. However, incident waves with big oblique angles through the liquid—solid superlattice will produce a superwide angle transmission in a certain frequency range so that total reflection does not occur. Together with the simulation by finite element analysis, theoretical analysis by using transfer matrix method suggests the Bragg scattering of the Lamb waves as the physical mechanism of acoustic wave super-propagation far beyond the critical angle. Incident angle, filling fraction, and material thickness have significant influences on propagation. Superwide-angle propagation phenomenon may have potential applications in nondestructive evaluation of layered structures and controlling of energy flux.

  6. Using Digital Technology to See Angles from Different Angles. Part 1: Corners

    ERIC Educational Resources Information Center

    Host, Erin; Baynham, Emily; McMaster, Heather

    2014-01-01

    In Part 1 of their article, Erin Host, Emily Baynham and Heather McMaster use a combination of digital technology and concrete materials to explore the concept of "corners". They provide a practical, easy to follow sequence of activities that builds on students' understandings. [For "Using Digital Technology to See Angles from…

  7. Compression failure of angle-ply laminates

    NASA Technical Reports Server (NTRS)

    Peel, L. D.; Hyer, M. W.; Shuart, M. J.

    1992-01-01

    Test results from the compression loading of (+ or - Theta/ - or + Theta)(sub 6s) angle-ply IM7-8551-7a specimens, 0 less than or = Theta less than or = 90 degs, are presented. The observed failure strengths and modes are discussed, and typical stress-strain relations shown. Using classical lamination theory and the maximum stress criterion, an attempt is made to predict failure stress as a function of Theta. This attempt results in poor correlation with test results and thus a more advanced model is used. The model, which is based on a geometrically nonlinear theory, and which was taken from previous work, includes the influence of observed layer waviness. The waviness is described by the wave length and the wave amplitude. The theory is briefly described and results from the theory are correlated with test results. It is shown that by using levels of waviness observed in the specimens, the correlation between predictions and observations is good.

  8. Wide Angle View of Arsia Mons Volcano

    NASA Technical Reports Server (NTRS)

    1999-01-01

    Arsia Mons (above) is one of the largest volcanoes known. This shield volcano is part of an aligned trio known as the Tharsis Montes--the others are Pavonis Mons and Ascraeus Mons. Arsia Mons is rivaled only by Olympus Mons in terms of its volume. The summit of Arsia Mons is more than 9 kilometers (5.6 miles) higher than the surrounding plains. The crater--or caldera--at the volcano summit is approximately 110 km (68 mi) across. This view of Arsia Mons was taken by the red and blue wide angle cameras of the Mars Global Surveyor Mars Orbiter Camera (MOC) system. Bright water ice clouds (the whitish/bluish wisps) hang above the volcano--a common sight every martian afternoon in this region. Arsia Mons is located at 120o west longitude and 9o south latitude. Illumination is from the left.

  9. Large angle magnetic suspension test fixture

    NASA Technical Reports Server (NTRS)

    Britcher, Colin P.

    1993-01-01

    Progress made under the subject grant in the period from 1 Nov. 1992 to 31 May 1993 is presented. The research involves the continued development of the Large Angle Magnetic Suspension Test Fixture (LAMSTF) and also the recommissioning of an additional piece of exisiting hardware. During the period in question, the initial configuration of LAMSTF was completed and made routinely and reliably operational. A digital phase advance controller was completed and documented. The goal of a controlled 360 deg rotation was achieved. Work started on the recommissioning of the Annular Suspension and Pointing System (ASPS). Work completed during the report period included: modeling; position sensing; controller; support of the Second International Symposium on Magnetic Suspension Technology; and recommissioning of the Annular Suspension and Pointing System.

  10. A superconducting large-angle magnetic suspension

    NASA Astrophysics Data System (ADS)

    Downer, James R.; Anastas, George V., Jr.; Bushko, Dariusz A.; Flynn, Frederick J.; Goldie, James H.; Gondhalekar, Vijay; Hawkey, Timothy J.; Hockney, Richard L.; Torti, Richard P.

    1992-12-01

    SatCon Technology Corporation has completed a Small Business Innovation Research (SBIR) Phase 2 program to develop a Superconducting Large-Angle Magnetic Suspension (LAMS) for the NASA Langley Research Center. The Superconducting LAMS was a hardware demonstration of the control technology required to develop an advanced momentum exchange effector. The Phase 2 research was directed toward the demonstration for the key technology required for the advanced concept CMG, the controller. The Phase 2 hardware consists of a superconducting solenoid ('source coils') suspended within an array of nonsuperconducting coils ('control coils'), a five-degree-of-freedom positioning sensing system, switching power amplifiers, and a digital control system. The results demonstrated the feasibility of suspending the source coil. Gimballing (pointing the axis of the source coil) was demonstrated over a limited range. With further development of the rotation sensing system, enhanced angular freedom should be possible.

  11. A superconducting large-angle magnetic suspension

    NASA Technical Reports Server (NTRS)

    Downer, James; Goldie, James; Torti, Richard

    1991-01-01

    The component technologies were developed required for an advanced control moment gyro (CMG) type of slewing actuator for large payloads. The key component of the CMG is a large-angle magnetic suspension (LAMS). The LAMS combines the functions of the gimbal structure, torque motors, and rotor bearings of a CMG. The LAMS uses a single superconducting source coil and an array of cryoresistive control coils to produce a specific output torque more than an order of magnitude greater than conventional devices. The designed and tested LAMS system is based around an available superconducting solenoid, an array of twelve room-temperature normal control coils, and a multi-input, multi-output control system. The control laws were demonstrated for stabilizing and controlling the LAMS system.

  12. Pivoting micromirror designs for large orientation angles

    NASA Astrophysics Data System (ADS)

    Garcia, Ernest J.

    2000-08-01

    This paper describes mechanical designed concepts for a class of pivoting micromirrors that permit relatively large angles of orientation to be obtained when configured in large arrays. Micromirror arrays can be utilized in a variety of applications ranging from optical switching to beam-front correction in a variety of technologies. This particular work is concerned with silicon surface micromachining. The multi-layer polysilicon surface micromachined process developed at Sandia National Laboratories is used to fabricate micromirror arrays that consists of capacitive electrode pairs which are used to electrostatically actuator mirrors to their desired positions and suitable elastic suspensions which support the 2 micrometers thick mirror structures. The designs described have been fabricated and successfully operated.

  13. An optical angle of attack sensor

    NASA Astrophysics Data System (ADS)

    McDevitt, T. Kevin; Owen, F. Kevin

    A major source of transonic and supersonic wind-tunnel test data uncertainty is due to angle of attack (alpha) measurement errors caused by unknown sting and balance deflections under load. A novel laser-based instrument has been developed to enable continuous time-dependent alpha measurements to be made without signal dropout. Detectors capable of 0.01-deg resolution over an 18-deg range and 0.03-deg resolution over a 44-deg range with time-dependent outputs of 60 Hz have been developed. This capability is sufficient to provide accurate real-time alpha information for correlation with model balance measurements during transport and fighter model testing. Proof-of-concept experiments, along with the results of recent measurements conducted at the NASA Ames 9 x 7-ft supersonic wind tunnel, are presented. Experiments were also conducted to determine the reliable range, sensitivity, and long-term stability of the instrument.

  14. Experimental determination of the quark mixing angles

    SciTech Connect

    Castro, G.L. )

    1991-07-30

    This paper reviews the current status of the determination of the quark mixing angles {vert bar}V{sub qq{prime}}{vert bar}, where q = u,c; q{prime} = d,s,b. The authors consider essentially exclusive decay processes, taking into account the main sources of uncertainties, the available calculations of flavor symmetry breaking for hadronic matrix elements and the possibilities of improvement offered by new experimental results. In some cases the authors provide full expressions for {vert bar}V{sub qq{prime}}{vert bar} in terms of measurable decay properties, which can be useful for new experimental data. Finally, the authors discuss briefly the effects on the unitarity tests of the Cabibbo-Kobayashi-Maskawa matrix when the authors consider recent corrections to the determination of {vert bar}V {sub ud}{vert bar}.

  15. Novel therapies for open-angle glaucoma

    PubMed Central

    Wentz, Scott M.; Kim, Nathaniel J.; Wang, Jenny; Amireskandari, Annahita; Siesky, Brent

    2014-01-01

    Open-angle glaucoma is a multifactorial optic neuropathy characterized by progressive loss of retinal ganglion cells and their axons. It is an irreversible disease with no established cure. The only currently approved treatment is aimed at lowering intraocular pressure, the most significant risk factor known to date. However, it is now clear that there are other risk factors involved in glaucoma's pathophysiology. To achieve future improvements in glaucoma management, new approaches to therapies and novel targets must be developed. Such therapies may include new tissue targets for lowering intraocular pressure, molecules influencing ocular hemodynamics, and treatments providing neuroprotection of retinal ganglion cells. Furthermore, novel drug delivery systems are in development that may improve patient compliance, increase bioavailability, and decrease adverse side effects. PMID:25580256

  16. Angle-resolved photoemission extended fine structure

    SciTech Connect

    Barton, J.J.

    1985-03-01

    Measurements of the Angle-Resolved Photoemission Extended Fine Structure (ARPEFS) from the S(1s) core level of a c(2 x 2)S/Ni(001) are analyzed to determine the spacing between the S overlayer and the first and second Ni layers. ARPEFS is a type of photoelectron diffraction measurement in which the photoelectron kinetic energy is swept typically from 100 to 600 eV. By using this wide range of intermediate energies we add high precision and theoretical simplification to the advantages of the photoelectron diffraction technique for determining surface structures. We report developments in the theory of photoelectron scattering in the intermediate energy range, measurement of the experimental photoemission spectra, their reduction to ARPEFS, and the surface structure determination from the ARPEFS by combined Fourier and multiple-scattering analyses. 202 refs., 67 figs., 2 tabs.

  17. Evolution of Barb Angle and Filament Eruption

    NASA Astrophysics Data System (ADS)

    Su, J. T.; Liu, Y.; Zhang, H. Q.; Kurokawa, H.; Yurchyshyn, V.; Shibata, K.; Bao, X. M.; Wang, G. P.; Li, C.

    2005-09-01

    Hα observations of a quiescent U-shaped filament were obtained at Big Bear Solar Observatory and at Hida Observatory with the Flare Monitoring Telescope. The filament was located in the southern hemisphere on 1998 November 4. We study the evolution of the angle of a barb with respect to the axis of the filament and find the evolution can be divided into two phases: a rise from the acute phase to the obtuse phase and a fall. Thus, this indicates that the chirality of this barb changes with time. Moreover, in the process of evolution, we find that interconnection of the part of the filament bearing the barb with the whole filament became either weakened or strengthened. We impute the final eruption of the filament to the chirality evolution of the barb.

  18. A superconducting large-angle magnetic suspension

    NASA Technical Reports Server (NTRS)

    Downer, James R.; Anastas, George V., Jr.; Bushko, Dariusz A.; Flynn, Frederick J.; Goldie, James H.; Gondhalekar, Vijay; Hawkey, Timothy J.; Hockney, Richard L.; Torti, Richard P.

    1992-01-01

    SatCon Technology Corporation has completed a Small Business Innovation Research (SBIR) Phase 2 program to develop a Superconducting Large-Angle Magnetic Suspension (LAMS) for the NASA Langley Research Center. The Superconducting LAMS was a hardware demonstration of the control technology required to develop an advanced momentum exchange effector. The Phase 2 research was directed toward the demonstration for the key technology required for the advanced concept CMG, the controller. The Phase 2 hardware consists of a superconducting solenoid ('source coils') suspended within an array of nonsuperconducting coils ('control coils'), a five-degree-of-freedom positioning sensing system, switching power amplifiers, and a digital control system. The results demonstrated the feasibility of suspending the source coil. Gimballing (pointing the axis of the source coil) was demonstrated over a limited range. With further development of the rotation sensing system, enhanced angular freedom should be possible.

  19. Disequilibrium dihedral angles in dolerite sills

    USGS Publications Warehouse

    Holness, Marian B.; Richardson, Chris; Helz, Rosalind T.

    2012-01-01

    The geometry of clinopyroxene-plagioclase-plagioclase junctions in mafic rocks, measured by the median dihedral angle Θcpp, is created during solidification. In the solidifying Kilauea Iki (Hawaii) lava lake, the wider junctions between plagioclase grains are the first to be filled by pyroxene, followed by the narrower junctions. The final Θcpp, attained when all clinopyroxene-plagioclase-plagioclase junctions are formed, is 78° in the upper crust of the lake, and 85° in the lower solidification front. Θcpp in the 3.5-m-thick Traigh Bhàn na Sgùrra sill (Inner Hebrides) is everywhere 78°. In the Whin Sill (northern England, 38 m thick) and the Portal Peak sill (Antarctica, 129 m thick), Θcpp varies symmetrically, with the lowest values at the margins. The 266-m-thick Basement Sill (Antarctica) has asymmetric variation of Θcpp, attributed to a complex filling history. The chilled margins of the Basement Sill are partially texturally equilibrated, with high Θcpp. The plagioclase grain size in the two widest sills varies asymmetrically, with the coarsest rocks found in the upper third. Both Θcpp and average grain size are functions of model crystallization times. Θcpp increases from 78° to a maximum of ∼100° as the crystallization time increases from 1 to 500 yr. Because the use of grain size as a measure of crystallization time is dependent on an estimate of crystal growth rates, dihedral angles provide a more direct proxy for cooling rates in dolerites.

  20. Soller collimators for small angle neutron scattering

    SciTech Connect

    Crawford, R.K.; Epperson, J.E.; Thiyagarajan, P.

    1988-09-30

    Small angle diffractometers at pulsed sources need to have fairly short flight paths if they are to make use of the long-wavelength portion of the spectrum without encountering problems from frame overlap or sacrificing intensity with band-limiting or pulse-removing choppers. With such short flight paths, achieving the necessary angular collimation in the incident beam while utilizing the full source size (/approximately/10 cm diameter) and a reasonable sample size (/approximately/1 cm diameter) requires the use of converging multiple-aperture collimation. If the collimation channels are all focused to the same point on the detector then the large sample size will not affect Q/sub min/ or the Q-resolution, even if the sample-to-detector distance is short. The Small Angle Diffractometer (SAD) at IPNS uses crossed converging soller collimators to provide focusing multiple-aperture collimation having /approximately/400 converging beam channels with essentially no ''dead'' space between them. This entire collimator system occupies a distance of only /approximately/60 cm along the incident flight path, while providing angular collimation of 0.003 radians FWHM. The dimensions for the SAD upstream collimator are L/sub c/ = 32.8 cm, d/sub 1/ = 0.974 mm, d/sub 2/ = 0.851 mm, while for the SAD downstream collimator L/sub c/ = 25.0 cm, d/sub 1/ - 0.844 mm, d/sub 2/ = 0.750 mm. Each of these collimators has 20 blades defining 21 horizontal or vertical channels. 4 refs., 6 figs.

  1. Crank angle detecting system for engines

    SciTech Connect

    Yuzawa, H.; Nishiyama, M.; Nakamura, K.; Ishigami, K.

    1988-05-31

    An ignition system for a multi-cylinder internal combustion engine is described comprising: (a) engine cylinders in which spark plugs are installed respectively, (b) indicating means disposed so as to synchronize with an engine crankshaft and formed with a large number of slits and a small number of slits, the large number of slits being provided for indicating crankshaft angular positions and the small number of slits being provided for indicating predetermined piston strokes and wherein the small number of slits have mutually different widths from each other to distinguish between piston strokes of at least the groups of cylinders; (c) sensing means for sensing crankshaft angular positions in cooperation with the large number of slits of the indicating means and outputting a crank angle signal representing the crankshaft angular position and for sensing the predetermined piston strokes in cooperation with the small number of slits and outputting different width piston stroke signals corresponding to the different width slits; (d) discriminating means for identifying each cylinder group and outputting cylinder group identification signals on the basis of the different width stroke signals derived from the sensing means; (e) ignition timing determining means for generating an ignition timing signal on the basis of the crank angle signal; (f) ignition coil controlling means for generating ignition coil current signals corresponding to the cylinder group identification signals; and (g) ignition timing controlling means for generating cylinder group ignition signals in response to the ignition coil current signals and ignition timing signal so that the spark plugs of each cylinder group are ignited at a proper time.

  2. Euler angles, quaternions, and transformation matrices for space shuttle analysis

    NASA Technical Reports Server (NTRS)

    Henderson, D. M.

    1977-01-01

    Relationships between the Euler angles and the transformation matrix, the quaternion and the transformation matrix, and the Euler angles and the quaternion are analyzed, and equations developed are applied directly to current space shuttle problems. The twelve three-axis Euler transformation matrices as functions of the Euler angles, the equations for the quaternion as a function of the Euler angles, and the Euler angles as a function of the transformation matrix elements are included along with a group of utility subroutines to accomplish the Euler matrix, quaternion matrix, and Euler quaternion relationships.

  3. Incident Angle of Saltating Particles in Wind-Blown Sand

    PubMed Central

    Fu, Lin-Tao; Bo, Tian-Li; Gu, Hai-Hua; Zheng, Xiao-Jing

    2013-01-01

    Incident angle of saltating particles plays a very important role in aeolian events. In this paper, the incident angles of sand particles near the sand bed were measured in wind tunnel. It reveals that the incident angles range widely from 0° to 180° and thereby the means of angles are larger than published data. Surprisingly, it is found the proportion that angles of 5°–15° occupy is far below previous reports. The measuring height is probably the most important reason for the measurement differences between this study and previous investigations. PMID:23874470

  4. Optimal relative view angles for an object viewed multiple times

    NASA Astrophysics Data System (ADS)

    Gilani, Syed U.; Shende, Apoorva; Nguyen, Bao; Stilwell, Daniel J.

    2015-05-01

    Typically, the detection of an object of interest improves as we view the object from multiple angles. For cases where viewing angle matters, object detection can be improved further by optimally selecting the relative angles of multiple views. This motivates the search for viewing angles that maximize the expected probability of detection. Although our work is motivated by applications in subsea sensing, our fundamental analysis is easily adapted for other classes of applications. The specific challenge that motivates our work is the selection of optimal viewing angles for subsea sensing in which sonar is used for bathymetric imaging.

  5. Angle Kappa and its importance in refractive surgery

    PubMed Central

    Moshirfar, Majid; Hoggan, Ryan N.; Muthappan, Valliammai

    2013-01-01

    Angle kappa is the difference between the pupillary and visual axis. This measurement is of paramount consideration in refractive surgery, as proper centration is required for optimal results. Angle kappa may contribute to MFIOL decentration and its resultant photic phenomena. Adjusting placement of MFIOLs for angle kappa is not supported by the literature but is likely to help reduce glare and haloes. Centering LASIK in angle kappa patients over the corneal light reflex is safe, efficacious, and recommended. Centering in-between the corneal reflex and the entrance pupil is also safe and efficacious. The literature regarding PRK in patients with an angle kappa is sparse but centering on the corneal reflex is assumed to be similar to centering LASIK on the corneal reflex. Thus, centration of MFIOLs, LASIK, and PRK should be focused on the corneal reflex for patients with a large angle kappa. More research is needed to guide surgeons’ approach to angle kappa. PMID:24379548

  6. Note: A gel based imaging technique of the iridocorneal angle for evaluation of angle-closure glaucoma

    NASA Astrophysics Data System (ADS)

    Shinoj, V. K.; Murukeshan, V. M.; Baskaran, M.; Aung, T.

    2014-06-01

    Noninvasive medical imaging techniques have high potential in the field of ocular imaging research. Angle closure glaucoma is a major disease causing blindness and a possible way of detection is the examination of the anterior chamber angle in eyes. Here, a simple optical method for the evaluation of angle-closure glaucoma is proposed and illustrated. The light propagation from the region associated with the iridocorneal angle to the exterior of eye is considered analytically. The design of the gel assisted probe prototype is carried out and the imaging of iridocorneal angle is performed on an eye model.

  7. High-angle origin of the currently low-angle Badwater Turtleback fault, Death Valley, California

    SciTech Connect

    Miller, M.G. )

    1991-04-01

    The late Cenozoic Badwater Turtleback fault separates an upper plate of volcanic and sedimentary rocks from a lower plate of predominantly mylonitic plutonic and metamorphic rocks. The Turtleback fault, however, is not a single continuous surface, but consists of a least three generations of faults. These faults occur as discrete, crosscutting segments that progressively decrease in age and increase in dip to the west. Therefore, they probably began at moderate to steep angles but rotated to lower angles with extensional strain. If so, lower plate mylonitic rocks also restore to steeper dips and suggest that transport of the upper plate occurred on moderate to steeply dipping surfaces in the middle and upper crust. The crosscutting nature of the fault segments and their initial moderate to steep dips, plus a possible offset marker on one of the segments, are most consistent with moderate amounts of extension in the Death Valley region.

  8. Impact on Spin Tune From Horizontal Orbital Angle Between Snakes and Orbital Angle Between Spin Rotators

    SciTech Connect

    Bai,M.; Ptitsyn, V.; Roser, T.

    2008-10-01

    To keep the spin tune in the spin depolarizing resonance free region is required for accelerating polarized protons to high energy. In RHIC, two snakes are located at the opposite side of each accelerator. They are configured to yield a spin tune of 1/2. Two pairs of spin rotators are located at either side of two detectors in each ring in RHIC to provide longitudinal polarization for the experiments. Since the spin rotation from vertical to longitudinal is localized between the two rotators, the spin rotators do not change the spin tune. However, due to the imperfection of the orbits around the snakes and rotators, the spin tune can be shifted. This note presents the impact of the horizontal orbital angle between the two snakes on the spin tune, as well as the effect of the vertical orbital angle between two rotators at either side of the collision point on the spin tune.

  9. Mapping of low flip angles in magnetic resonance

    NASA Astrophysics Data System (ADS)

    Balezeau, Fabien; Eliat, Pierre-Antoine; Bordelois Cayamo, Alejandro; Saint-Jalmes, Hervé

    2011-10-01

    Errors in the flip angle have to be corrected in many magnetic resonance imaging applications, especially for T1 quantification. However, the existing methods of B1 mapping fail to measure lower values of the flip angle despite the fact that these are extensively used in dynamic acquisition and 3D imaging. In this study, the nonlinearity of the radiofrequency (RF) transmit chain, especially for very low flip angles, is investigated and a simple method is proposed to accurately determine both the gain of the RF transmitter and the B1 field map for low flip angles. The method makes use of the spoiled gradient echo sequence with long repetition time (TR), such as applied in the double-angle method. It uses an image acquired with a flip angle of 90° as a reference image that is robust to B1 inhomogeneity. The ratio of the image at flip angle alpha to the image at a flip angle of 90° enables us to calculate the actual value of alpha. This study was carried out at 1.5 and 4.7 T, showing that the linearity of the RF supply system is highly dependent on the hardware. The method proposed here allows us to measure the flip angle from 1° to 60° with a maximal uncertainty of 10% and to correct T1 maps based on the variable flip angle method.

  10. Relating lepton mixing angles with lepton mass hierarchy

    NASA Astrophysics Data System (ADS)

    Borah, Debasish

    2016-01-01

    We revisit the possibility of relating lepton mixing angles with lepton mass hierarchies in a model-independent way. Guided by the existence of such relations in the quark sector, we first consider all the mixing angles, both in charged lepton and neutrino sectors to be related to the respective mass ratios. This allows us to calculate the leptonic mixing angles observed in neutrino oscillations as functions of the lightest neutrino mass. We show that for both normal and inverted hierarchical neutrino masses, this scenario does not give rise to correct leptonic mixing angles. We then show that correct leptonic mixing angles can be generated with normal hierarchical neutrino masses if the relation between mixing angle and mass ratio is restricted to 1-2 and 1-3 mixing in both charged lepton and neutrino sectors leaving the 2-3 mixing angles as free parameters. We then restrict the lightest neutrino mass as well as the difference between 2-3 mixing angles in charged lepton and neutrino sectors from the requirement of producing correct leptonic mixing angles. We constrain the lightest neutrino mass to be around 0.002 eV and leptonic Dirac CP phase δCP such that sin2δ CP ˜ (0.35-0.50). We also construct the leptonic mass matrices in terms of 2-3 mixing angles and lightest neutrino mass and briefly comment on the possibility of realizing texture zeros in the neutrino mass matrix.

  11. Development of a scanning angle total internal reflection Raman spectrometer.

    PubMed

    McKee, Kristopher J; Smith, Emily A

    2010-04-01

    A scanning angle total internal reflection (SATIR) Raman spectrometer has been developed for measuring interfacial phenomena with chemical specificity and high axial resolution perpendicular to the interface. The instrument platform is an inverted optical microscope with added automated variable angle optics to control the angle of an incident laser on a prism/sample interface. These optics include two motorized translation stages, the first containing a focusing lens and the second a variable angle galvanometer mirror. The movement of all instrument components is coordinated to ensure that the same sample location and area are probed at each angle. At angles greater than the critical angle, an evanescent wave capable of producing Raman scatter is generated in the sample. The Raman scatter is collected by a microscope objective and directed to a dispersive spectrometer and charge-coupled device detector. In addition to the collected Raman scatter, light reflected from the prism/sample interface is collected to provide calibration parameters that enable modeling the distance over which the Raman scatter is collected for depth profiling measurements. The developed instrument has an incident angle range of 25.5 degrees-75.5 degrees, with a 0.05 degrees angle resolution. Raman scatter can be collected from a ZnSe/organic interface over a range of roughly 35-180 nm. Far from the critical angle, the achieved axial resolution perpendicular to the focal plane is approximately 34 nm. This is roughly a 30-fold improvement relative to confocal Raman microscopy. PMID:20441324

  12. Rubber Hand Illusion Affects Joint Angle Perception

    PubMed Central

    Butz, Martin V.; Kutter, Esther F.; Lorenz, Corinna

    2014-01-01

    The Rubber Hand Illusion (RHI) is a well-established experimental paradigm. It has been shown that the RHI can affect hand location estimates, arm and hand motion towards goals, the subjective visual appearance of the own hand, and the feeling of body ownership. Several studies also indicate that the peri-hand space is partially remapped around the rubber hand. Nonetheless, the question remains if and to what extent the RHI can affect the perception of other body parts. In this study we ask if the RHI can alter the perception of the elbow joint. Participants had to adjust an angular representation on a screen according to their proprioceptive perception of their own elbow joint angle. The results show that the RHI does indeed alter the elbow joint estimation, increasing the agreement with the position and orientation of the artificial hand. Thus, the results show that the brain does not only adjust the perception of the hand in body-relative space, but it also modifies the perception of other body parts. In conclusion, we propose that the brain continuously strives to maintain a consistent internal body image and that this image can be influenced by the available sensory information sources, which are mediated and mapped onto each other by means of a postural, kinematic body model. PMID:24671172

  13. Small-angle scattering from fat fractals

    NASA Astrophysics Data System (ADS)

    Anitas, Eugen M.

    2014-06-01

    A number of experimental small-angle scattering (SAS) data are characterized by a succession of power-law decays with arbitrarily decreasing values of scattering exponents. To describe such data, here we develop a new theoretical model based on 3D fat fractals (sets with fractal structure, but nonzero volume) and show how one can extract structural information about the underlying fractal structure. We calculate analytically the monodisperse and polydisperse SAS intensity (fractal form factor and structure factor) of a newly introduced model of fat fractals and study its properties in momentum space. The system is a 3D deterministic mass fractal built on an extension of the well-known Cantor fractal. The model allows us to explain a succession of power-law decays and respectively, of generalized power-law decays (GPLD; superposition of maxima and minima on a power-law decay) with arbitrarily decreasing scattering exponents in the range from zero to three. We show that within the model, the present analysis allows us to obtain the edges of all the fractal regions in the momentum space, the number of fractal iteration and the fractal dimensions and scaling factors at each structural level in the fractal. We applied our model to calculate an analytical expression for the radius of gyration of the fractal. The obtained quantities characterizing the fat fractal are correlated to variation of scaling factor with the iteration number.

  14. LDEF yaw and pitch angle estimates

    NASA Technical Reports Server (NTRS)

    Banks, Bruce A.; Gebauer, Linda

    1992-01-01

    Quantification of the LDEF yaw and pitch misorientations is crucial to the knowledge of atomic oxygen exposure of samples placed on LDEF. Video camera documentation of the LDEF spacecraft prior to grapple attachment, atomic oxygen shadows on experiment trays and longerons, and a pinhole atomic oxygen camera placed on LDEF provided sources of documentation of the yaw and pitch misorientation. Based on uncertainty-weighted averaging of data, the LDEF yaw offset was found to be 8.1 plus or minus 0.6 degrees, allowing higher atomic oxygen exposure of row 12 than initially anticipated. The LDEF pitch angle offset was found to be 0.8 plus or minus 0.4 degrees, such that the space end was tipped forward toward the direction of travel. The resulting consequences of the yaw and pitch misorientation of LDEF on the atomic oxygen fluence is a factor of 2.16 increase for samples located on row 12, and a factor of 1.18 increase for samples located on the space end compared to that which would be expected for perfect orientation.

  15. Reconditioning of Cassini Narrow-Angle Camera

    NASA Technical Reports Server (NTRS)

    2002-01-01

    These five images of single stars, taken at different times with the narrow-angle camera on NASA's Cassini spacecraft, show the effects of haze collecting on the camera's optics, then successful removal of the haze by warming treatments.

    The image on the left was taken on May 25, 2001, before the haze problem occurred. It shows a star named HD339457.

    The second image from left, taken May 30, 2001, shows the effect of haze that collected on the optics when the camera cooled back down after a routine-maintenance heating to 30 degrees Celsius (86 degrees Fahrenheit). The star is Maia, one of the Pleiades.

    The third image was taken on October 26, 2001, after a weeklong decontamination treatment at minus 7 C (19 F). The star is Spica.

    The fourth image was taken of Spica January 30, 2002, after a weeklong decontamination treatment at 4 C (39 F).

    The final image, also of Spica, was taken July 9, 2002, following three additional decontamination treatments at 4 C (39 F) for two months, one month, then another month.

    Cassini, on its way toward arrival at Saturn in 2004, is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the Cassini mission for NASA's Office of Space Science, Washington, D.C.

  16. Impact Angle Control of Interplanetary Shock Geoeffectiveness

    NASA Astrophysics Data System (ADS)

    Oliveira, D.; Raeder, J.

    2014-12-01

    We use OpenGGCM global MHD simulations to study the nightside magnetospheric/ magnetotail/ ionospheric responses to interplanetary (IP) fast foward shocks. Three cases are presented in this study: two inclined oblique shocks, hereafter IOS-1 and IOS-2, where the latter has a Mach number twice stronger than the former. Both shocks have impact angles of 30o in relation to the Sun-Earth line. Lastly, we choose a frontal perpendicular shock, FPS, whose shock normal is along th Sun-Earth line, with the same Mach number as IOS-1. We find that, in the IOS-1 case, due to the north-south asymmetry, the magnetotail is deflected southward, leading to a mild compression. The geomagnetic activity observed in the nightside ionosphere is then weak. On the other hand, in the head-on case, the FPS compresses the magnetotail on both sides symmetrically. This compression triggers a substorm allowing a larger amount of stored energy in the magnetotail to be released to the nightside ionosphere, resulting in a larger geomagnetic activity there. By comparing IOS-2 and FPS, we find that, despite the IOS-2 having a larger Mach number, the FPS leads to larger geomagnetic responses in the ionosphere nightside. As a result, we conclude that IP shocks with similar upstream conditions, such as magnetic field, speed, density, and even Mach number, can be differently geoeffective, depending on their shock normal orientation.

  17. Impact angle control of interplanetary shock geoeffectiveness

    NASA Astrophysics Data System (ADS)

    Oliveira, D. M.; Raeder, J.

    2014-10-01

    We use Open Geospace General Circulation Model global MHD simulations to study the nightside magnetospheric, magnetotail, and ionospheric responses to interplanetary (IP) fast forward shocks. Three cases are presented in this study: two inclined oblique shocks, hereafter IOS-1 and IOS-2, where the latter has a Mach number twice stronger than the former. Both shocks have impact angles of 30° in relation to the Sun-Earth line. Lastly, we choose a frontal perpendicular shock, FPS, whose shock normal is along the Sun-Earth line, with the same Mach number as IOS-1. We find that, in the IOS-1 case, due to the north-south asymmetry, the magnetotail is deflected southward, leading to a mild compression. The geomagnetic activity observed in the nightside ionosphere is then weak. On the other hand, in the head-on case, the FPS compresses the magnetotail from both sides symmetrically. This compression triggers a substorm allowing a larger amount of stored energy in the magnetotail to be released to the nightside ionosphere, resulting in stronger geomagnetic activity. By comparing IOS-2 and FPS, we find that, despite the IOS-2 having a larger Mach number, the FPS leads to a larger geomagnetic response in the nightside ionosphere. As a result, we conclude that IP shocks with similar upstream conditions, such as magnetic field, speed, density, and Mach number, can have different geoeffectiveness, depending on their shock normal orientation.

  18. Moderate positive spin Hall angle in uranium

    SciTech Connect

    Singh, Simranjeet; Anguera, Marta; Barco, Enrique del E-mail: cwmsch@rit.edu; Springell, Ross; Miller, Casey W. E-mail: cwmsch@rit.edu

    2015-12-07

    We report measurements of spin pumping and the inverse spin Hall effect in Ni{sub 80}Fe{sub 20}/uranium bilayers designed to study the efficiency of spin-charge interconversion in a super-heavy element. We employ broad-band ferromagnetic resonance on extended films to inject a spin current from the Ni{sub 80}Fe{sub 20} (permalloy) into the uranium layer, which is then converted into an electric field by the inverse spin Hall effect. Surprisingly, our results suggest a spin mixing conductance of order 2 × 10{sup 19} m{sup −2} and a positive spin Hall angle of 0.004, which are both merely comparable with those of several transition metals. These results thus support the idea that the electronic configuration may be at least as important as the atomic number in governing spin pumping across interfaces and subsequent spin Hall effects. In fact, given that both the magnitude and the sign are unexpected based on trends in d-electron systems, materials with unfilled f-electron orbitals may hold additional exploration avenues for spin physics.

  19. Wide-angle flat field telescope

    NASA Technical Reports Server (NTRS)

    Hallam, K. L.; Howell, B. J.; Wilson, M. E.

    1986-01-01

    Described is an unobscured three mirror wide angle telescopic imaging system comprised of an input baffle which provides a 20 deg (Y axis) x 30 deg (X axis) field of view, a primary mirror having a convex spherical surface, a secondary mirror having a concave ellipsoidal reflecting surface, a tertiary mirror having a concave spherical reflecting surface. The mirrors comprise mirror elements which are offset segments of parent mirrors whose axes and vertices commonly lie on the system's optical axis. An iris diaphragm forming an aperture stop is located between the secondary and tertiary mirror with its center also being coincident with the optical axis and being further located at the beam waist of input light beams reflected from the primary and secondary mirror surfaces. At the system focus following the tertiary mirror is located a flat detector which may be, for example, a TV imaging tube or a photographic film. When desirable, a spectral transmission filter is placed in front of the detector in close proximity thereto.

  20. Uncertainties in Small-Angle Measurement Systems Used to Calibrate Angle Artifacts.

    PubMed

    Stone, Jack A; Amer, Mohamed; Faust, Bryon; Zimmerman, Jay

    2004-01-01

    We have studied a number of effects that can give rise to errors in small-angle measurement systems when they are used to calibrate artifacts such as optical polygons. Of these sources of uncertainty, the most difficult to quantify are errors associated with the measurement of imperfect, non-flat faces of the artifact, causing the instrument to misinterpret the average orientation of the surface. In an attempt to shed some light on these errors, we have compared autocollimator measurements to angle measurements made with a Fizeau phase-shifting interferometer. These two instruments have very different operating principles and implement different definitions of the orientation of a surface, but (surprisingly) we have not yet seen any clear differences between results obtained with the autocollimator and with the interferometer. The interferometer is in some respects an attractive alternative to an autocollimator for small-angle measurement; it implements an unambiguous and robust definition of surface orientation in terms of the tilt of a best-fit plane, and it is easier to quantify likely errors of the interferometer measurements than to evaluate autocollimator uncertainty.

  1. Uncertainties in Small-Angle Measurement Systems Used to Calibrate Angle Artifacts

    PubMed Central

    Stone, Jack A.; Amer, Mohamed; Faust, Bryon; Zimmerman, Jay

    2004-01-01

    We have studied a number of effects that can give rise to errors in small-angle measurement systems when they are used to calibrate artifacts such as optical polygons. Of these sources of uncertainty, the most difficult to quantify are errors associated with the measurement of imperfect, non-flat faces of the artifact, causing the instrument to misinterpret the average orientation of the surface. In an attempt to shed some light on these errors, we have compared autocollimator measurements to angle measurements made with a Fizeau phase-shifting interferometer. These two instruments have very different operating principles and implement different definitions of the orientation of a surface, but (surprisingly) we have not yet seen any clear differences between results obtained with the autocollimator and with the interferometer. The interferometer is in some respects an attractive alternative to an autocollimator for small-angle measurement; it implements an unambiguous and robust definition of surface orientation in terms of the tilt of a best-fit plane, and it is easier to quantify likely errors of the interferometer measurements than to evaluate autocollimator uncertainty. PMID:27366616

  2. Non-contact measurement of rotation angle with solo camera

    NASA Astrophysics Data System (ADS)

    Gan, Xiaochuan; Sun, Anbin; Ye, Xin; Ma, Liqun

    2015-02-01

    For the purpose to measure a rotation angle around the axis of an object, a non-contact rotation angle measurement method based on solo camera was promoted. The intrinsic parameters of camera were calibrated using chessboard on principle of plane calibration theory. The translation matrix and rotation matrix between the object coordinate and the camera coordinate were calculated according to the relationship between the corners' position on object and their coordinates on image. Then the rotation angle between the measured object and the camera could be resolved from the rotation matrix. A precise angle dividing table (PADT) was chosen as the reference to verify the angle measurement error of this method. Test results indicated that the rotation angle measurement error of this method did not exceed +/- 0.01 degree.

  3. Sunspot group tilt angle measurements from historical observations

    NASA Astrophysics Data System (ADS)

    Senthamizh Pavai, V.; Arlt, R.; Diercke, A.; Denker, C.; Vaquero, J. M.

    2016-10-01

    Sunspot positions from various historical sets of solar drawings are analyzed with respect to the tilt angles of bipolar sunspot groups. Data by Scheiner, Hevelius, Staudacher, Zucconi, Schwabe, and Spörer deliver a series of average tilt angles spanning a period of 270 years, additional to previously found values for 20th-century data obtained by other authors. We find that the average tilt angles before the Maunder minimum were not significantly different from the modern values. However, the average tilt angles of a period 50 years after the Maunder minimum, namely for cycles 0 and 1, were much lower and near zero. The normal tilt angles before the Maunder minimum suggest that it was not abnormally low tilt angles which drove the solar cycle into a grand minimum.

  4. Determination of detector rotation angle in the experiment based on the total internal reflection using an equilateral right angle prism

    NASA Astrophysics Data System (ADS)

    Hendro, Viridi, S.; Pratama, Y.

    2015-04-01

    We present a relation between incident angle and rotation angle detector in the Total Internal Reflection (TIR) experiments when using a right angle prism. In the TIR method, the light coming toward the prism will experience reflection and out of the prism at a certain angle direction. Results of analysis of the geometry and Snell's law shows that the angular position of the detector is not only determined by the angle of incidence of light alone but also by the size of the prism and the detector position from the rotation axis of goniometer. The experimental results show relation between the angle of detector and angle of goniometer. When the prism rotated 45 °, position of goniometer detector is 2×45 °. However, when the prism rotated at an angle instead of 45 °, detector position µ is not always equal to twice the rotation angle goniometer ψ, so that this relationship needs to be corrected. This correction is also determined by the value of the refractive index of the prism is used. By knowing the relationship between detector position and the incident angle of light, this formulation can be used to control the position of the sample and the detector in the experiments based on ATR.

  5. Characterizing the combinatorial beam angle selection problem

    NASA Astrophysics Data System (ADS)

    Bangert, Mark; Ziegenhein, Peter; Oelfke, Uwe

    2012-10-01

    The beam angle selection (BAS) problem in intensity-modulated radiation therapy is often interpreted as a combinatorial optimization problem, i.e. finding the best combination of η beams in a discrete set of candidate beams. It is well established that the combinatorial BAS problem may be solved efficiently with metaheuristics such as simulated annealing or genetic algorithms. However, the underlying parameters of the optimization process, such as the inclusion of non-coplanar candidate beams, the angular resolution in the space of candidate beams, and the number of evaluated beam ensembles as well as the relative performance of different metaheuristics have not yet been systematically investigated. We study these open questions in a meta-analysis of four strategies for combinatorial optimization in order to provide a reference for future research related to the BAS problem in intensity-modulated radiation therapy treatment planning. We introduce a high-performance inverse planning engine for BAS. It performs a full fluence optimization for ≈3600 treatment plans per hour while handling up to 50 GB of dose influence data (≈1400 candidate beams). For three head and neck patients, we compare the relative performance of a genetic, a cross-entropy, a simulated annealing and a naive iterative algorithm. The selection of ensembles with 5, 7, 9 and 11 beams considering either only coplanar or all feasible candidate beams is studied for an angular resolution of 5°, 10°, 15° and 20° in the space of candidate beams. The impact of different convergence criteria is investigated in comparison to a fixed termination after the evaluation of 10 000 beam ensembles. In total, our simulations comprise a full fluence optimization for about 3000 000 treatment plans. All four combinatorial BAS strategies yield significant improvements of the objective function value and of the corresponding dose distributions compared to standard beam configurations with equi

  6. Can a surgeon drill accurately at a specified angle?

    PubMed Central

    Brioschi, Valentina; Cook, Jodie; Arthurs, Gareth I

    2016-01-01

    Objectives To investigate whether a surgeon can drill accurately a specified angle and whether surgeon experience, task repetition, drill bit size and perceived difficulty influence drilling angle accuracy. Methods The sample population consisted of final-year students (n=25), non-specialist veterinarians (n=22) and board-certified orthopaedic surgeons (n=8). Each participant drilled a hole twice in a horizontal oak plank at 30°, 45°, 60°, 80°, 85° and 90° angles with either a 2.5  or a 3.5 mm drill bit. Participants then rated the perceived difficulty to drill each angle. The true angle of each hole was measured using a digital goniometer. Results Greater drilling accuracy was achieved at angles closer to 90°. An error of ≤±4° was achieved by 84.5 per cent of participants drilling a 90° angle compared with approximately 20 per cent of participants drilling a 30–45° angle. There was no effect of surgeon experience, task repetition or drill bit size on the mean error for intended versus achieved angle. Increased perception of difficulty was associated with the more acute angles and decreased accuracy, but not experience level. Clinical significance This study shows that surgeon ability to drill accurately (within ±4° error) is limited, particularly at angles ≤60°. In situations where drill angle is critical, use of computer-assisted navigation or custom-made drill guides may be preferable. PMID:27547423

  7. Bilateral acute angle-closure glaucoma after dexfenfluramine treatment.

    PubMed

    Denis, P; Charpentier, D; Berros, P; Touameur, S

    1995-01-01

    We report the case of a patient with narrow angles who had an attack of bilateral acute angle-closure glaucoma precipitated by dexfenfluramine, a serotoninergic drug developed for appetite suppression. Although the exact mechanism remains uncertain, the pupillary block observed in our case may be the result of the serotoninergic or indirect parasympatholytic properties of the drug on the iris sphincter muscle. Serotonergic psychoactive drugs should be prescribed cautiously in patients with known narrow angles and should be monitored by an ophthalmologist.

  8. Angle-specific transparent conducting electrodes with metallic gratings

    SciTech Connect

    Rivolta, N. X. A. Maes, B.

    2014-08-07

    Transparent conducting electrodes, which are not made from indium tin oxide, and which display a strong angular dependence are useful for various technologies. Here, we introduce a tilted silver grating that combines a large conductance with a strong and angle-specific transmittance. When the light incidence angle matches the tilt angle of the grating, transmittance is close to the maximum along a very broadband range. We explain the behavior through simulations that show in detail the plasmonic and interference effects at play.

  9. Chapman Solar Zenith Angle variations at Titan

    NASA Astrophysics Data System (ADS)

    Royer, Emilie M.; Ajello, Joseph; Holsclaw, Gregory; West, Robert; Esposito, Larry W.; Bradley, Eric Todd

    2016-10-01

    Solar XUV photons and magnetospheric particles are the two main sources contributing to the airglow in the Titan's upper atmosphere. We are focusing here on the solar XUV photons and how they influence the airglow intensity. The Cassini-UVIS observations analyzed in this study consist each in a partial scan of Titan, while the center of the detector stays approximately at the same location on Titan's disk. We used observations from 2008 to 2012, which allow for a wide range of Solar Zenith Angle (SZA). Spectra from 800 km to 1200 km of altitude have been corrected from the solar spectrum using TIMED/SEE data. We observe that the airglow intensity varies as a function of the SZA and follows a Chapman curve. Three SZA regions are identified: the sunlit region ranging from 0 to 50 degrees. In this region, the intensity of the airglow increases, while the SZA decreases. Between SZA 50 and 100 degrees, the airglow intensity decreases from it maximum to its minimum. In this transition region the upper atmosphere of Titan changes from being totally sunlit to being in the shadow of the moon. For SZA 100 to 180 degrees, we observe a constant airglow intensity close to zero. The behavior of the airglow is also similar to the behavior of the electron density as a function of the SZA as observed by Ågren at al (2009). Both variables exhibit a decrease intensity with increasing SZA. The goal of this study is to understand such correlation. We demonstrate the importance of the solar XUV photons contribution to the Titan airglow and prove that the strongest contribution to the Titan dayglow occurs by solar fluorescence rather than the particle impact that predominates at night.

  10. Antibody elbow angles are influenced by their light chain class

    SciTech Connect

    Stanfield, R; Zemla, A; Wilson, I; Rupp, B

    2006-01-12

    We have examined the elbow angles for 365 different Fab fragments, and observe that Fabs with lambda light chains have adopted a wider range of elbow angles than their kappa-chain counterparts, and that the lambda light chain Fabs are frequently found with very large (>195{sup o}) elbow angles. This apparent hyperflexibility of lambda-chain Fabs may be due to an insertion in their switch region, which is one residue longer than in kappa chains, with glycine occurring most frequently at the insertion position. A new, web-based computer program that was used to calculate the Fab elbow angles is also described.

  11. Resolution-Tunable Angle-Resolved X-ray Imaging

    SciTech Connect

    Hirano, Keiichi

    2004-05-12

    A resolution-tunable double-crystal device was successfully applied to angle-resolved x-ray imaging. The angular resolution of a Si (220) double-crystal analyzer was tuned between 0.5'' and 2.3'' through the offset angle at {lambda} = 0.0733nm. The throughput of the analyzer was higher than 90%. The angle-resolved images of a spider were recorded on nuclear emulsion plates at various angular resolutions. It was clearly observed that the quality of the angle-resolved image varies with the angular resolution of the analyzer.

  12. The Relation Between Sacral Angle and Vertical Angle of Sacral Curvature and Lumbar Disc Degeneration

    PubMed Central

    Ghasemi, Ahmad; Haddadi, Kaveh; Khoshakhlagh, Mohammad; Ganjeh, Hamid Reza

    2016-01-01

    Abstract The purpose of this study is to determine the reliability and validity of a goniometric measurement of the vertical angle of the sacrum and sacral angle (SA), and their relationships to lumbar degeneration. A herniated lumbar disc is one of the most frequent medical issues. Investigators in a number of studies have reported associated risk factors for prevalent disc degeneration. Atypical lumbosacral angles and curvature are thought to contribute to the degradation of the spine by many researchers. This study analyzed 360 patients referred to our clinic from 2013 to 2015 due to low back pain. A cross-sectional case–control study was designed in order to compare the sagittal alignment of the lumbosacral area in 3 groups of patients suffering from LBP. A total 120 patients were in a control group with a normal lumbar magnetic resonance imaging (MRI), 120 patients had lumbar disk herniation (LDH), and 120 patients had spinal stenosis. From the sagittal plan of lumbar MRI, SA and vertical angle of sacral curvature (VASC) were determined and then analyzed. The means of VASC in these groups were: 38.98 (SD: 6.36 ± 0.58), 40.89 (SD: 7.69 ± 0.69), and 40.54 (SD: 7.13 ± 0.92), respectively (P = 0.089). Moreover, studies of SA in 3 groups showed that the means of SA were: 39.30 (SD: 6.69 ± 0.63), 40.52 (SD: 7.47 ± 0.65), and 35.63 (SD: 6.07 ± 0.79), respectively. Relation between SA and spinal stenosis was just statistically significant (P ≤ 0.05). One significant limitation of our study is the lack of standing MRI for increased accuracy of measurement. However, we were reluctant to give patients needless exposure to radiation from conventional X-ray, and instead used MRI scans. We did not find any significant correlation between the VASC and LDH in lumbar MRI. Also, SA is not an independent risk factor for LDH in men and women. We suggested that there are several biomechanical factors involved in LDH. PMID:26871821

  13. NEW ESTIMATES OF THE INCLINATION, POSITION ANGLE, PITCH ANGLE, AND SCALE HEIGHT OF THE WHIRLPOOL GALAXY

    SciTech Connect

    Hu Tao; Shao Zhengyi; Peng Qiuhe E-mail: taohu.nju@gmail.com

    2013-01-10

    The inclination (i) and position angle (PA) of the Whirlpool galaxy (M51) are critical to modeling and interpreting observations. Here we make improved estimates of these parameters by fitting logarithmic spirals to the main arms. From separate fits to each major arm, we obtain i = 20. Degree-Sign 3 {+-} 2. Degree-Sign 8 and PA = 12. Degree-Sign 0 {+-} 2. Degree-Sign 5. We then use Poisson's equation for the logarithmic perturbation of the density to estimate the mean vertical scale height (H) of M51 to be 95-178 pc.

  14. Revisiting the Force-Joint Angle Relationship After Eccentric Exercise.

    PubMed

    Welsh, Molly C; Allen, David L; Batliner, Matthew E; Byrnes, William C

    2015-12-01

    The purpose of this study was to evaluate force-angle curve fitting techniques pre-eccentric exercise, quantify changes in curve characteristics postexercise, and examine the relationship between curve changes and markers of muscle damage. Fourteen males unaccustomed to eccentric exercise performed 60 eccentric muscle actions of the elbow flexors. Maximal voluntary isometric force was measured throughout a range of angles pre- (Pre1 and Pre2), immediately post (IP), and 1, 2, 4, and 7 days postexercise. Force-angle curves for each visit were constructed using second-order polynomials. Changes in curve characteristics (optimal angle, peak force, curve height), range of motion, soreness, and creatine kinase activity were quantified. Optimal joint angle and force at optimal angle were significantly correlated from Pre1 to Pre2 (ICC = 0.821 and 0.979, respectively). Optimal angle was significantly right shifted (p = 0.035) by 10.4 ± 12.9° from Pre2 to IP and was restored by 1 day post exercise. Interestingly, the r value for curve fit was significantly decreased (p < 0.001) from Pre2 (r = 0.896) to IP (r = 0.802) and 1 day post exercise (r = 0.750). Curve height was significantly decreased (39%) IP and restored to pre-exercise height by 4 days postexercise. There was no correlation between optimal angle or curve height and other damage markers. In conclusion, force-angle relationships can be accurately described using second-order polynomials. After eccentric exercise, the force-angle curve is flattened and shifted (downward and rightward), but these changes are not correlated to other markers of muscle damage. Changes in the force-angle relationship are multifaceted, but determining the physiological significance of these changes requires further investigation.

  15. Role of Optical Coherence Tomography in Assessing Anterior Chamber Angles

    PubMed Central

    Kochupurakal, Reema Thomas; Jha, Kirti Nath; Rajalakshmi, A.R.; Nagarajan, Swathi; Ezhumalai, G.

    2016-01-01

    Introduction Gonioscopy is the gold standard in assessing anterior chamber angles. However, interobserver variations are common and there is a need for reliable objective method of assessment. Aim To compare the anterior chamber angle by gonioscopy and Spectral Domain Optical Coherence Tomography (SD-OCT) in individuals with shallow anterior chamber. Materials and Methods This comparative observational study was conducted in a rural tertiary multi-speciality teaching hospital. A total of 101 eyes of 54 patients with shallow anterior chamber on slit lamp evaluation were included. Anterior chamber angle was graded by gonioscopy using the shaffer grading system. Angles were also assessed by SD-OCT with Trabecular Iris Angle (TIA) and Angle Opening Distance (AOD). Chi-square test, sensitivity, specificity, positive and negative predictive value to find correlation between OCT parameters and gonioscopy grading. Results Females represented 72.7%. The mean age was 53.93 ±8.24 years and mean anterior chamber depth was 2.47 ± 0.152 mm. Shaffer grade ≤ 2 were identified in 95(94%) superior, 42(41.5%) inferior, 65(64.3%) nasal and 57(56.4%) temporal quadrants. Cut-off values of TIA ≤ 22° and AOD ≤ 290 μm were taken as narrow angles on SD-OCT. TIA of ≤ 22° were found in 88(92.6%) nasal and 87(87%) temporal angles. AOD of ≤ 290 μm was found in 73(76.8%) nasal and 83(83%) temporal quadrants. Sensitivity in detecting narrow angles was 90.7% and 82.2% for TIA and AOD, while specificity was 11.7% and 23.4%, respectively. Conclusion Individuals were found to have narrow angles more with SD-OCT. Sensitivity was high and specificity was low in detecting narrow angles compared to gonioscopy, making it an unreliable tool for screening. PMID:27190851

  16. Fracture angle and strain-energy-density-factor of a crack at hole at an arbitrary angle

    NASA Technical Reports Server (NTRS)

    Hsu, Y. C.; Forman, R. G.

    1975-01-01

    For both the maximum stress criterion and strain-energy-density-factor (S) theory, fracture angle (the initial angle of crack growth) is predicted by using opening and sliding mode stress intensity factors. These theoretical predictions are consistent with experimental fracture angles. For the S theory, the crack spreads in the direction of the negative fracture angle in a plane for which S is a minimum. This quantity was obtained analytically. The experimental data of the critical S on plexiglass fracture specimens remains essentially constant.

  17. Impacted third molars and risk of angle fracture.

    PubMed

    Meisami, T; Sojat, A; Sàndor, G K B; Lawrence, H P; Clokie, C M L

    2002-04-01

    The purpose of this study was to assess the influence of the presence, position, and severity of impaction of the mandibular third molars, on the incidence of mandibular angle fractures. A retrospective cohort study was designed for patients presenting to the Division of Oral and Maxillofacial Surgery, Toronto General Hospital (Toronto, Canada), for treatment of mandibular fractures from January 1995 to June 2000. The independent variables in this study were the presence, position and severity of impaction of third molars. The outcome variable was the incidence of mandibular angle fractures. Hospital charts and panoramic radiographs were used to determine and classify these variables. The demographic data included age, sex, mechanism of injury and number of mandibular fractures. The study sample comprised 413 mandibular fractures in 214 patients. The incidence of angle fractures was found to be significantly higher in the male population and was most commonly seen in the third decade of life. Assault remained the most significant aetiological factor. Patients with third molars had thrice the increased risk of angle fractures when compared to patients without (P<0.001). Impaction of third molars significantly increased the incidence of angle fractures (P<0.001). The severity and angulation of third molar impactions were not significantly associated with angle fractures. This study provides evidence that patients with retained impacted third molars are significantly more susceptible to angle fracture than those without. The risk for angle fracture, however, does not seem to be influenced by the severity of impaction.

  18. 47 CFR 25.205 - Minimum angle of antenna elevation.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 47 Telecommunication 2 2011-10-01 2011-10-01 false Minimum angle of antenna elevation. 25.205 Section 25.205 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES SATELLITE COMMUNICATIONS Technical Standards § 25.205 Minimum angle of antenna elevation. (a) Earth...

  19. 47 CFR 25.205 - Minimum angle of antenna elevation.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 47 Telecommunication 2 2014-10-01 2014-10-01 false Minimum angle of antenna elevation. 25.205 Section 25.205 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES SATELLITE COMMUNICATIONS Technical Standards § 25.205 Minimum angle of antenna elevation. (a) Earth...

  20. 47 CFR 25.205 - Minimum angle of antenna elevation.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 2 2010-10-01 2010-10-01 false Minimum angle of antenna elevation. 25.205 Section 25.205 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES SATELLITE COMMUNICATIONS Technical Standards § 25.205 Minimum angle of antenna elevation. (a) Earth...

  1. 47 CFR 25.205 - Minimum angle of antenna elevation.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 47 Telecommunication 2 2013-10-01 2013-10-01 false Minimum angle of antenna elevation. 25.205 Section 25.205 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES SATELLITE COMMUNICATIONS Technical Standards § 25.205 Minimum angle of antenna elevation. (a) Earth...

  2. 47 CFR 25.205 - Minimum angle of antenna elevation.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 47 Telecommunication 2 2012-10-01 2012-10-01 false Minimum angle of antenna elevation. 25.205 Section 25.205 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES SATELLITE COMMUNICATIONS Technical Standards § 25.205 Minimum angle of antenna elevation. (a) Earth...

  3. Magnetic prism alignment system for measuring large-angle strabismus.

    PubMed

    Bishop, John Edward

    2014-02-01

    Prismatic measurement of large-angle strabismus requires the simultaneous use of two or more prisms for neutralization. To facilitate the clinical measurement of large-angle strabismus a new prism system was designed utilizing a flat plate and a ferrous metal surface coupled with prisms containing rare earth magnets implanted in their base and bottom surfaces. PMID:24569000

  4. A Novel Monopulse Angle Estimation Method for Wideband LFM Radars

    PubMed Central

    Zhang, Yi-Xiong; Liu, Qi-Fan; Hong, Ru-Jia; Pan, Ping-Ping; Deng, Zhen-Miao

    2016-01-01

    Traditional monopulse angle estimations are mainly based on phase comparison and amplitude comparison methods, which are commonly adopted in narrowband radars. In modern radar systems, wideband radars are becoming more and more important, while the angle estimation for wideband signals is little studied in previous works. As noise in wideband radars has larger bandwidth than narrowband radars, the challenge lies in the accumulation of energy from the high resolution range profile (HRRP) of monopulse. In wideband radars, linear frequency modulated (LFM) signals are frequently utilized. In this paper, we investigate the monopulse angle estimation problem for wideband LFM signals. To accumulate the energy of the received echo signals from different scatterers of a target, we propose utilizing a cross-correlation operation, which can achieve a good performance in low signal-to-noise ratio (SNR) conditions. In the proposed algorithm, the problem of angle estimation is converted to estimating the frequency of the cross-correlation function (CCF). Experimental results demonstrate the similar performance of the proposed algorithm compared with the traditional amplitude comparison method. It means that the proposed method for angle estimation can be adopted. When adopting the proposed method, future radars may only need wideband signals for both tracking and imaging, which can greatly increase the data rate and strengthen the capability of anti-jamming. More importantly, the estimated angle will not become ambiguous under an arbitrary angle, which can significantly extend the estimated angle range in wideband radars. PMID:27271629

  5. 46 CFR 169.622 - Rudder angle indicators.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 7 2011-10-01 2011-10-01 false Rudder angle indicators. 169.622 Section 169.622 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) NAUTICAL SCHOOLS SAILING SCHOOL VESSELS Machinery and Electrical Steering Systems § 169.622 Rudder angle indicators. Each vessel must have a...

  6. 46 CFR 169.622 - Rudder angle indicators.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 7 2013-10-01 2013-10-01 false Rudder angle indicators. 169.622 Section 169.622 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) NAUTICAL SCHOOLS SAILING SCHOOL VESSELS Machinery and Electrical Steering Systems § 169.622 Rudder angle indicators. Each vessel must have a...

  7. 46 CFR 169.622 - Rudder angle indicators.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 7 2014-10-01 2014-10-01 false Rudder angle indicators. 169.622 Section 169.622 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) NAUTICAL SCHOOLS SAILING SCHOOL VESSELS Machinery and Electrical Steering Systems § 169.622 Rudder angle indicators. Each vessel must have a...

  8. 46 CFR 169.622 - Rudder angle indicators.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 7 2012-10-01 2012-10-01 false Rudder angle indicators. 169.622 Section 169.622 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) NAUTICAL SCHOOLS SAILING SCHOOL VESSELS Machinery and Electrical Steering Systems § 169.622 Rudder angle indicators. Each vessel must have a...

  9. 46 CFR 169.622 - Rudder angle indicators.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Rudder angle indicators. 169.622 Section 169.622 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) NAUTICAL SCHOOLS SAILING SCHOOL VESSELS Machinery and Electrical Steering Systems § 169.622 Rudder angle indicators. Each vessel must have a...

  10. Multiple incidence angle SIR-B experiment over Argentina

    NASA Technical Reports Server (NTRS)

    Cimino, Jobea; Casey, Daren; Wall, Stephen; Brandani, Aldo; Domik, Gitta; Leberl, Franz

    1986-01-01

    The Shuttle Imaging Radar (SIR-B), the second synthetic aperture radar (SAR) to fly aboard a shuttle, was launched on October 5, 1984. One of the primary goals of the SIR-B experiment was to use multiple incidence angle radar images to distinguish different terrain types through the use of their characteristic backscatter curves. This goal was accomplished in several locations including the Chubut Province of southern Argentina. Four descending image acquisitions were collected providing a multiple incidence angle image set. The data were first used to assess stereo-radargrammetric techniques. A digital elevation model was produced using the optimum pair of multiple incidence angle images. This model was then used to determine the local incidence angle of each picture element to generate curves of relative brightness vs. incidence angle. Secondary image products were also generated using the multi-angle data. The results of this work indicate that: (1) various forest species and various structures of a single species may be discriminated using multiple incidence angle radar imagery, and (2) it is essential to consider the variation in backscatter due to a variable incidence angle when analyzing and comparing data collected at varying frequencies and polarizations.

  11. Results of wide-angle underwater acoustic-telemetry tests

    SciTech Connect

    Ryerson, D.E.

    1982-03-01

    Acoustic telemetry provides wireless communication between subsurface ocean instrumentation systems and surface receiving equipment. Sandia National Laboratories' high data rate acoustic telemetry system has previously been demonstrated in water depths to 1600 feet and vertical cone angles to 70/sup 0/. Design changes and tests of the system are discussed showing that it can operate within vertical cone angles of 145/sup 0/.

  12. Precision issues in angle measurements by means of autocollimator

    NASA Astrophysics Data System (ADS)

    Filatov, Yuri V.; Larichev, Roman A.

    2014-11-01

    Ambiguity in plane angle definition is considered. Autocollimator performance is regarded from geometric ray optics and wave diffraction optics points of view. Few typical aberrations and their influence on image formation in autocollimator are presented. Modeling estimates of aberration influence on angle measurements are outlined.

  13. Unitarity Triangle Angle Measurements at BaBar

    SciTech Connect

    Latham, Thomas E.; /SLAC

    2005-06-30

    We present recent results of measurements of the Unitarity Triangle angles alpha, beta and gamma made with the BaBar detector at the PEP-II asymmetric B factory. We present recent results of measurements of the Unitarity Triangle angles alpha, beta and gamma made with the BaBar detector at the PEP-II asymmetric B factory.

  14. Complete 360° circumferential SSOCT gonioscopy of the iridocorneal angle

    NASA Astrophysics Data System (ADS)

    McNabb, Ryan P.; Kuo, Anthony N.; Izatt, Joseph A.

    2014-02-01

    The ocular iridocorneal angle is generally an optically inaccessible area when viewed directly through the cornea due to the high angle of incidence required and the large index of refraction difference between air and cornea (nair = 1.000 and ncornea = 1.376) resulting in total internal reflection. Gonioscopy allows for viewing of the angle by removing the aircornea interface through the use of a special contact lens on the eye. Gonioscopy is used clinically to visualize the angle directly but only en face. Optical coherence tomography (OCT) has been used to image the angle and deeper structures via an external approach. Typically, this imaging technique is performed by utilizing a conventional anterior segment OCT scanning system. However, instead of imaging the apex of the cornea, either the scanner or the subject is tilted such that the corneoscleral limbus is orthogonal to the optical axis of the scanner requiring multiple volumes to obtain complete circumferential coverage of the ocular angle. We developed a novel gonioscopic OCT (GOCT) system that images the entire ocular angle within a single volume via an "internal" approach through the use of a custom radially symmetric gonioscopic contact lens. We present, to our knowledge, the first complete 360° circumferential volumes of the iridocorneal angle from a direct, internal approach.

  15. Reliable Angle Assessment During Periacetabular Osteotomy with a Novel Device

    PubMed Central

    Elmengaard, Brian; Rømer, Lone; Søballe, Kjeld

    2008-01-01

    We developed and assessed a measuring device for intraoperative assessment of the acetabular index and center edge angle during acetabular reorientation in periacetabular osteotomy. We asked whether reliable assessment of angles could be made using the device; to be reliable we presumed the variability of angle measurements should not exceed that of inherent variability when assessing angles on radiographs (± 5°). The device was mounted bilaterally on the pelvis, and using fluoroscopy, angle measurements were obtained with adjustable measuring discs. We conducted a cadaver study to assess intraobserver and interobserver variability of the device and to assess if pelvic positioning influenced variation of measurements. Intraoperative measurements of 35 consecutive patients were compared with measurements on postoperative radiographs. Intraoperatively obtained angle measurements differed less than ± 5° from measurements on postoperative radiographs and the intraobserver and interobserver variability of the device were confined within ± 5°. Positioning did not influence the variation of angle measurements beyond intraobserver variability of the device when applying arcs of tilt and rotation of ± 12.5°. We believe the device is a potentially helpful tool in the periacetabular osteotomy. It is simple to use and facilitates repeated reliable angle measurements during acetabular reorientation, making intraoperative radiographs unnecessary. PMID:18264742

  16. 46 CFR 58.01-40 - Machinery, angles of inclination.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 2 2010-10-01 2010-10-01 false Machinery, angles of inclination. 58.01-40 Section 58.01... AUXILIARY MACHINERY AND RELATED SYSTEMS General Requirements § 58.01-40 Machinery, angles of inclination. (a) Propulsion machinery and all auxiliary machinery essential to the propulsion and safety of the vessel must...

  17. What convention is used for the illumination and view angles?

    Atmospheric Science Data Center

    2014-12-08

    ... Azimuth angles are measured clockwise from the direction of travel to local north. For both the Sun and cameras, azimuth describes the ... to the equator, because of its morning equator crossing time. Additionally, the difference in view and solar azimuth angle will be near ...

  18. Magnetic prism alignment system for measuring large-angle strabismus.

    PubMed

    Bishop, John Edward

    2014-02-01

    Prismatic measurement of large-angle strabismus requires the simultaneous use of two or more prisms for neutralization. To facilitate the clinical measurement of large-angle strabismus a new prism system was designed utilizing a flat plate and a ferrous metal surface coupled with prisms containing rare earth magnets implanted in their base and bottom surfaces.

  19. A Novel Monopulse Angle Estimation Method for Wideband LFM Radars.

    PubMed

    Zhang, Yi-Xiong; Liu, Qi-Fan; Hong, Ru-Jia; Pan, Ping-Ping; Deng, Zhen-Miao

    2016-01-01

    Traditional monopulse angle estimations are mainly based on phase comparison and amplitude comparison methods, which are commonly adopted in narrowband radars. In modern radar systems, wideband radars are becoming more and more important, while the angle estimation for wideband signals is little studied in previous works. As noise in wideband radars has larger bandwidth than narrowband radars, the challenge lies in the accumulation of energy from the high resolution range profile (HRRP) of monopulse. In wideband radars, linear frequency modulated (LFM) signals are frequently utilized. In this paper, we investigate the monopulse angle estimation problem for wideband LFM signals. To accumulate the energy of the received echo signals from different scatterers of a target, we propose utilizing a cross-correlation operation, which can achieve a good performance in low signal-to-noise ratio (SNR) conditions. In the proposed algorithm, the problem of angle estimation is converted to estimating the frequency of the cross-correlation function (CCF). Experimental results demonstrate the similar performance of the proposed algorithm compared with the traditional amplitude comparison method. It means that the proposed method for angle estimation can be adopted. When adopting the proposed method, future radars may only need wideband signals for both tracking and imaging, which can greatly increase the data rate and strengthen the capability of anti-jamming. More importantly, the estimated angle will not become ambiguous under an arbitrary angle, which can significantly extend the estimated angle range in wideband radars. PMID:27271629

  20. A gallery approach for off-angle iris recognition

    NASA Astrophysics Data System (ADS)

    Karakaya, Mahmut; Yoldash, Rashiduddin; Boehnen, Christopher

    2015-05-01

    It has been proven that hamming distance score between frontal and off-angle iris images of same eye differs in iris recognition system. The distinction of hamming distance score is caused by many factors such as image acquisition angle, occlusion, pupil dilation, and limbus effect. In this paper, we first study the effect of the angle variations between iris plane and the image acquisition systems. We present how hamming distance changes for different off-angle iris images even if they are coming from the same iris. We observe that increment in acquisition angle of compared iris images causes the increment in hamming distance. Second, we propose a new technique in off-angle iris recognition system that includes creating a gallery of different off-angle iris images (such as, 0, 10, 20, 30, 40, and 50 degrees) and comparing each probe image with these gallery images. We will show the accuracy of the gallery approach for off-angle iris recognition.

  1. Does Sacrococcygeal Angle Play a Role on Pilonidal Sinus Etiology?

    PubMed

    Eryilmaz, Ramazan; Isik, Arda; Okan, Ismail; Bilecik, Tuna; Yekeler, Ensar; Sahin, Mustafa

    2015-01-01

    The predisposing factors for the development of sacrococcygeal pilonidal disease (SPD) still remain undetermined. Here, we investigate the sacrococcygeal angle as a possible predisposing factor for the development of disease. Consecutive male patients admitted to our clinic with the diagnosis of SPD were included. Sex, age and BMI matched healthy controls without SPD were enrolled to the study. The predefined sacrococcygeal angles of patients and controls were measured on lateral pelvic radiographs by a single experienced radiologist. Thirty patients were included in each group. Sacrococcygeal angles of patients and control group were measured as 37.3±14.5 and 36.81±10.23 in patients and controls, respectively. The difference with respect to sacrococcygeal angle was not statistically significant between two groups. Sacrococcygeal angle which is the main skeletal determinant of intergluteal sulcus is not a predisposing factor for the development of sacrococcygeal pilonidal disease.

  2. The effect of knee joint angle on torque control.

    PubMed

    Sosnoff, Jacob J; Voudrie, Stefani J; Ebersole, Kyle T

    2010-01-01

    The purpose of the author's investigation was to examine the effect of knee joint angle on torque control of the quadriceps muscle group. In all, 12 healthy adults produced maximal voluntary contractions and submaximal torque (15, 30, and 45% MVC [maximal voluntary contraction]) at leg flexion angles of 15 degrees , 30 degrees , 60 degrees , and 90 degrees below the horizontal plane. As expected, MVC values changed with respect to joint angle with maximum torque output being greatest at 60 degrees and least at 15 degrees . During the submaximal tasks, participants appropriately scaled their torque output to the required targets. Absolute variability (i.e., standard deviation) of torque output was greatest at 60 degrees and 90 degrees knee flexion. However, relative variability as indexed by coefficient of variation (CV) decreased as joint angle increased, with the greatest CV occurring at 15 degrees . These results are congruent with the hypothesis that joint angle influences the control of torque.

  3. The anterior centre-edge angle. A cadaver study.

    PubMed

    Crockarell, J R; Trousdale, R T; Guyton, J L

    2000-05-01

    The anterior centre-edge (VCA) angle quantifies the anterior cover of the femoral head, and angles of less than 20 degrees are considered abnormal. We have measured the VCA angles in hips without osteoarthritic changes. We took bilateral false-profile radiographs of nine female and 30 male cadavers without signs of osteoarthritis. The mean age at the time of death was 72 years (46 to 92). The mean VCA angle was 32.8 degrees (17.7 to 53.6). The SD was 7.9 degrees. Our findings suggest that the threshold of abnormality of the VCA angle may be slightly lower than previously thought. This information may be useful in counselling patients with asymptomatic acetabular dysplasia.

  4. New mixing angles in the left-right symmetric model

    NASA Astrophysics Data System (ADS)

    Kokado, Akira; Saito, Takesi

    2015-12-01

    In the left-right symmetric model neutral gauge fields are characterized by three mixing angles θ12,θ23,θ13 between three gauge fields Bμ,WLμ 3,WRμ 3, which produce mass eigenstates Aμ,Zμ,Zμ', when G =S U (2 )L×S U (2 )R×U (1 )B-L×D is spontaneously broken down until U (1 )em . We find a new mixing angle θ', which corresponds to the Weinberg angle θW in the standard model with the S U (2 )L×U (1 )Y gauge symmetry, from these mixing angles. It is then shown that any mixing angle θi j can be expressed by ɛ and θ', where ɛ =gL/gR is a ratio of running left-right gauge coupling strengths. We observe that light gauge bosons are described by θ' only, whereas heavy gauge bosons are described by two parameters ɛ and θ'.

  5. Coming to Understand Angle and Angle Measure: A Design-Based Research Curriculum Study Using Context-Aware Ubiquitous Learning

    ERIC Educational Resources Information Center

    Crompton, Helen

    2013-01-01

    This study uses design-based research (DBR) to develop an empirically-substantiated instructional theory about students' development of angle and angle measure, with real-world connections and technological tools through the use of context-aware ubiquitous learning. The research questions guiding this research are: 1) How do students come to…

  6. Spectral data of specular reflectance, narrow-angle transmittance and angle-resolved surface scattering of materials for solar concentrators

    PubMed Central

    Good, Philipp; Cooper, Thomas; Querci, Marco; Wiik, Nicolay; Ambrosetti, Gianluca; Steinfeld, Aldo

    2015-01-01

    The spectral specular reflectance of conventional and novel reflective materials for solar concentrators is measured with an acceptance angle of 17.5 mrad over the wavelength range 300−2500 nm at incidence angles 15–60° using a spectroscopic goniometry system. The same experimental setup is used to determine the spectral narrow-angle transmittance of semi-transparent materials for solar collector covers at incidence angles 0–60°. In addition, the angle-resolved surface scattering of reflective materials is recorded by an area-scan CCD detector over the spectral range 350–1050 nm. A comprehensive summary, discussion, and interpretation of the results are included in the associated research article “Spectral reflectance, transmittance, and angular scattering of materials for solar concentrators” in Solar Energy Materials and Solar Cells. PMID:26862556

  7. From hygrophilic to superhygrophobic: theoretical conditions for making high-contact-angle surfaces from low-contact-angle materials.

    PubMed

    Marmur, Abraham

    2008-07-15

    The possibility of making high-contact-angle, rough surfaces from low-contact-angle materials has recently been suggested and demonstrated. A thermodynamic analysis of this possibility in terms of feasibility and stability is presented. It turns out that only roughness topographies that conform to a feasibility condition which is developed in the present paper can support this phenomenon. Even under conditions that support the phenomenon, the high-contact-angle state may not be stable, and transition from the heterogeneous (Cassie-Baxter) wetting regime to the homogeneous (Wenzel) regime with a lower contact angle may occur. In addition, it is suggested to use the general terms hygrophilic and hygrophobic (based on the Greek prefix hygro- that means liquid) to describe low- and high-contact-angle surfaces, respectively. PMID:18543997

  8. Spectral data of specular reflectance, narrow-angle transmittance and angle-resolved surface scattering of materials for solar concentrators.

    PubMed

    Good, Philipp; Cooper, Thomas; Querci, Marco; Wiik, Nicolay; Ambrosetti, Gianluca; Steinfeld, Aldo

    2016-03-01

    The spectral specular reflectance of conventional and novel reflective materials for solar concentrators is measured with an acceptance angle of 17.5 mrad over the wavelength range 300-2500 nm at incidence angles 15-60° using a spectroscopic goniometry system. The same experimental setup is used to determine the spectral narrow-angle transmittance of semi-transparent materials for solar collector covers at incidence angles 0-60°. In addition, the angle-resolved surface scattering of reflective materials is recorded by an area-scan CCD detector over the spectral range 350-1050 nm. A comprehensive summary, discussion, and interpretation of the results are included in the associated research article "Spectral reflectance, transmittance, and angular scattering of materials for solar concentrators" in Solar Energy Materials and Solar Cells.

  9. The range of options for handling plane angle and solid angle within a system of units

    NASA Astrophysics Data System (ADS)

    Quincey, Paul

    2016-04-01

    The radian and steradian are unusual units within the SI, originally belonging to their own category of ‘supplementary units’, with this status being changed to dimensionless ‘derived units’ in 1995. Recent papers have suggested that angles could be handled in two different ways within the SI, both differing from the present system. The purpose of this paper is to provide a framework for putting such suggestions into context, outlining the range of options that is available, together with the advantages and disadvantages of these options. Although less rigorously logical than some alternatives, the present SI approach is generally supported, but with some changes to the SI brochure to make the position clearer, in particular with regard to the designation of the radian and steradian as derived units.

  10. Fractures of angle of mandible – A retrospective study

    PubMed Central

    Singh, Sourav; Fry, Ramesh R.; Joshi, Ajit; Sharma, Geeta; Singh, Smita

    2012-01-01

    Aims This retrospective study was done to evaluate the efficacy of single miniplate osteosynthesis at superior border of angle of mandible. Material and methods In this study 50 patients were treated by single miniplate osteosynthesis according to Champy's principle. Bite force generated was used as a parameter for judging the efficacy of internal fixation. In this article we present our experience over the years in the management of the fractures of angle of mandible based on this model. Results Most patients were of 21–30 yrs of age with unilateral angle fracture of mandible except one patient who had isolated bilateral angle fracture. The patients were treated successfully according to Champy's principle of osteosynthesis. There was a progressive improvement in the bite force generated after osteosynthesis. Conclusions The angle of the mandible is an anatomically weak and an area susceptible to fracture. The presence of an impacted or partially erupted third molar tooth further weakens it. Angle of mandible is the most common site for fracture however, bilateral angle fracture is very rare and uncommon. Osteosynthesis according to Champy's model led to an early functional improvement as demonstrated by the bite force generated. PMID:25737858

  11. Moment-angle relations in the initial time of contraction.

    PubMed

    Rousanoglou, E N; Herzog, W; Boudolos, K D

    2010-09-01

    Standard moment-angle relations are typically obtained for values at maximum of contraction. Muscle properties for contraction times, similar to the short times of powerful athletic activities, may be more important than muscle properties that are obtained at maximum (TMAX) of contraction. The research question was whether moment-angle relations obtained during the initial time course of contraction are linearly scaled reflections of moment-angle relations obtained at maximum of contraction. The isometric moment of the knee extensor and the electromyographic activity (EMG) of the knee extensor and flexor muscles were measured at 9 knee angles in 22 elite female track and field jumpers. Absolute moments (Nm), relative moments (%TMAX) and EMG integrals were determined at 30 ms, 50 ms, 150 ms and 200 ms from the onset of contraction and at maximum. For moment-angle relations obtained during the initial time course of contraction, there was a shift of the optimum knee angle to a more extended knee. During the initial time course of the contraction, %TMAX moment was greater near full knee extension. The EMG activity was the same across knee angles. The results may have important practical implications for muscular force evaluation for activities where maximum force production is coupled to a short activation time.

  12. Ramp Angle, Not Plateau Height, Influences Transition Strategies.

    PubMed

    Sheehan, Riley C; Gottschall, Jinger S

    2016-10-01

    In a previous study, we found that participants modified how they transitioned onto and off of ramp configurations depending upon the incline. While the transition strategies were originally attributed to ramp angles, it is possible that the plateau influenced the strategies since the final surface height also differed. Ultimately, for the current study, we hypothesized that an individual's transition strategies would have significant main effects for ramp angle, but not plateau height. Twelve healthy, young adults transitioned onto 3 distinct ramp configurations, a 2.4-m ramp angled at 12.5° ending at a plateau height of 53 cm, a 1.2-m ramp angled at 23.5° ending at a plateau height of 53 cm, and a 2.4-m ramp angled at 23.5° ending at a plateau height of 99.5 cm. Kinematics, kinetics, and muscle activity were measured during the stance phase before contacting the ramp. In support of our hypothesis, impact peak, active peak, and all of the muscle activity variables had a significant main effect for ramp angle, with greater vertical force peaks and muscle activity on steeper ramp transitions. These findings support our previous interpretation that individuals use estimations of ramp angle, not plateau height, to determine their transition strategies.

  13. Biophysical optimality of the golden angle in phyllotaxis.

    PubMed

    Okabe, Takuya

    2015-01-01

    Plant leaves are arranged around a stem axis in a regular pattern characterized by common fractions, a phenomenon known as phyllotaxis or phyllotaxy. As plants grow, these fractions often transition according to simple rules related to Fibonacci sequences. This mathematical regularity originates from leaf primordia at the shoot tip (shoot apical meristem), which successively arise at fixed intervals of a divergence angle, typically the golden angle of 137.5°. Algebraic and numerical interpretations have been proposed to explain the golden angle observed in phyllotaxis. However, it remains unknown whether phyllotaxis has adaptive value, even though two centuries have passed since the phenomenon was discovered. Here, I propose a new adaptive mechanism explaining the presence of the golden angle. This angle is the optimal solution to minimize the energy cost of phyllotaxis transition. This model accounts for not only the high precision of the golden angle but also the occurrences of other angles observed in nature. The model also effectively explains the observed diversity of rational and irrational numbers in phyllotaxis. PMID:26471765

  14. Biophysical optimality of the golden angle in phyllotaxis

    NASA Astrophysics Data System (ADS)

    Okabe, Takuya

    2015-10-01

    Plant leaves are arranged around a stem axis in a regular pattern characterized by common fractions, a phenomenon known as phyllotaxis or phyllotaxy. As plants grow, these fractions often transition according to simple rules related to Fibonacci sequences. This mathematical regularity originates from leaf primordia at the shoot tip (shoot apical meristem), which successively arise at fixed intervals of a divergence angle, typically the golden angle of 137.5°. Algebraic and numerical interpretations have been proposed to explain the golden angle observed in phyllotaxis. However, it remains unknown whether phyllotaxis has adaptive value, even though two centuries have passed since the phenomenon was discovered. Here, I propose a new adaptive mechanism explaining the presence of the golden angle. This angle is the optimal solution to minimize the energy cost of phyllotaxis transition. This model accounts for not only the high precision of the golden angle but also the occurrences of other angles observed in nature. The model also effectively explains the observed diversity of rational and irrational numbers in phyllotaxis.

  15. Biophysical optimality of the golden angle in phyllotaxis

    PubMed Central

    Okabe, Takuya

    2015-01-01

    Plant leaves are arranged around a stem axis in a regular pattern characterized by common fractions, a phenomenon known as phyllotaxis or phyllotaxy. As plants grow, these fractions often transition according to simple rules related to Fibonacci sequences. This mathematical regularity originates from leaf primordia at the shoot tip (shoot apical meristem), which successively arise at fixed intervals of a divergence angle, typically the golden angle of 137.5°. Algebraic and numerical interpretations have been proposed to explain the golden angle observed in phyllotaxis. However, it remains unknown whether phyllotaxis has adaptive value, even though two centuries have passed since the phenomenon was discovered. Here, I propose a new adaptive mechanism explaining the presence of the golden angle. This angle is the optimal solution to minimize the energy cost of phyllotaxis transition. This model accounts for not only the high precision of the golden angle but also the occurrences of other angles observed in nature. The model also effectively explains the observed diversity of rational and irrational numbers in phyllotaxis. PMID:26471765

  16. Determination of basic friction angle using various laboratory tests.

    NASA Astrophysics Data System (ADS)

    Jang, Bo-An

    2016-04-01

    The basic friction angle of rock is an important factor of joint shear strength and is included within most shear strength criteria. It can be measured by direct shear test, triaxial compression test and tilt test. Tilt test is mostly used because it is the simplest method. However, basic friction angles measured using tilt test for same rock type or for one sample are widely distributed and often do not show normal distribution. In this research, the basic friction angles for the Hangdeung granite form Korea and Berea sandstone from USA are measured accurately using direct shear test and triaxial compression test. Then basic friction angles are again measured using tilt tests with various conditions and are compared with those measured using direct shear test and triaxial compression test to determine the optimum condition of tilt test. Three types of sliding planes, such as planes cut by saw and planes polished by #100 and #600 grinding powders, are prepared. When planes are polished by #100 grinding powder, the basic friction angles measured using direct shear test and triaxial compression test are very consistent and show narrow ranges. However, basic friction angles show wide ranges when planes are cut by saw and are polished by #600 grinding powder. The basic friction angle measured using tilt test are very close to those measured using direct shear test and triaxial compression test when plane is polished by #100 grinding powder. When planes are cut by saw and are polished by #600 grinding powder, basic friction angles measured using tilt test are slightly different. This indicates that tilt test with plane polished by #100 grinding powder can yield an accurate basic friction angle. In addition, the accurate values are obtained not only when planes are polished again after 10 times of tilt test, but values are averaged by more 30 times of tests.

  17. PREDITOR: a web server for predicting protein torsion angle restraints

    PubMed Central

    Berjanskii, Mark V.; Neal, Stephen; Wishart, David S.

    2006-01-01

    Every year between 500 and 1000 peptide and protein structures are determined by NMR and deposited into the Protein Data Bank. However, the process of NMR structure determination continues to be a manually intensive and time-consuming task. One of the most tedious and error-prone aspects of this process involves the determination of torsion angle restraints including phi, psi, omega and chi angles. Most methods require many days of additional experiments, painstaking measurements or complex calculations. Here we wish to describe a web server, called PREDITOR, which greatly accelerates and simplifies this task. PREDITOR accepts sequence and/or chemical shift data as input and generates torsion angle predictions (with predicted errors) for phi, psi, omega and chi-1 angles. PREDITOR combines sequence alignment methods with advanced chemical shift analysis techniques to generate its torsion angle predictions. The method is fast (<40 s per protein) and accurate, with 88% of phi/psi predictions being within 30° of the correct values, 84% of chi-1 predictions being correct and 99.97% of omega angles being correct. PREDITOR is 35 times faster and up to 20% more accurate than any existing method. PREDITOR also provides accurate assessments of the torsion angle errors so that the torsion angle constraints can be readily fed into standard structure refinement programs, such as CNS, XPLOR, AMBER and CYANA. Other unique features to PREDITOR include dihedral angle prediction via PDB structure mapping, automated chemical shift re-referencing (to improve accuracy), prediction of proline cis/trans states and a simple user interface. The PREDITOR website is located at: . PMID:16845087

  18. Automated small tilt-angle measurement using Lau interferometry

    SciTech Connect

    Prakash, Shashi; Singh, Sumitra; Rana, Santosh

    2005-10-01

    A technique for a tilt-angle measurement of reflecting objects based on the Lau interferometry coupled with the moire readout has been proposed. A white-light incoherent source illuminates a set of two gratings, resulting in the generation of the Fresnel image due to the Lau effect. The Fresnel image is projected onto a reflecting object. The image reflected from the object is superimposed onto an identical grating, which results in the formation of a moire fringe pattern. The inclination angle of moire fringes is a function of tilt angle of the object. Theory and experimental arrangement of the proposed technique is presented and results of the investigation are reported.

  19. Determination of intrinsic spin Hall angle in Pt

    SciTech Connect

    Wang, Yi; Deorani, Praveen; Qiu, Xuepeng; Kwon, Jae Hyun; Yang, Hyunsoo

    2014-10-13

    The spin Hall angle in Pt is evaluated in Pt/NiFe bilayers by spin torque ferromagnetic resonance measurements and is found to increase with increasing the NiFe thickness. To extract the intrinsic spin Hall angle in Pt by estimating the total spin current injected into NiFe from Pt, the NiFe thickness dependent measurements are performed and the spin diffusion in the NiFe layer is taken into account. The intrinsic spin Hall angle of Pt is determined to be 0.068 at room temperature and is found to be almost constant in the temperature range of 13–300 K.

  20. Measurement of Critical Contact Angle in a Microgravity Space Experiment

    NASA Technical Reports Server (NTRS)

    Concus, P.; Finn, R.; Weislogel, M.

    1998-01-01

    Mathematical theory predicts that small changes in container shape or in contact angle can give rise to large shifts of liquid in a microgravity environment. This phenomenon was investigated in the Interface Configuration Experiment on board the USMT,2 Space Shuttle flight. The experiment's "double proboscis" containers were designed to strike a balance between conflicting requirements of sizable volume of liquid shift (for ease of observation) and abruptness of the shift (for accurate determination of critical contact angle). The experimental results support the classical concept of macroscopic contact angle and demonstrate the role of hysteresis in impeding orientation toward equilibrium.

  1. Measurement of Critical Contact Angle in a Microgravity Space Experiment

    NASA Technical Reports Server (NTRS)

    Concus, P.; Finn, R.; Weislogel, M.

    1998-01-01

    Mathematical theory predicts that small changes in container shape or in contact angle can give rise to large shifts of liquid in a microgravity environment. This phenomenon was investigated in the Interface Configuration Experiment on board the USML-2 Space Shuttle flight. The experiment's "double proboscis" containers were designed to strike a balance between conflicting requirements of sizable volume of liquid shift (for ease of observation) and abruptness of the shift (for accurate determination of critical contact angle). The experimental results support the classical concept of macroscopic contact angle and demonstrate the role of hysteresis in impeding orientation toward equilibrium.

  2. Measurement of critical contact angle in a microgravity space experiment

    NASA Astrophysics Data System (ADS)

    Concus, P.; Finn, R.; Weislogel, M.

    Mathematical theory predicts that small changes in container shape or in contact angle can give rise to large shifts of liquid in a microgravity environment. This phenomenon was investigated in the Interface Configuration Experiment on board the NASA USML-2 Space Shuttle flight. The experiment's ``double proboscis'' containers were designed to strike a balance between conflicting requirements of sizable volume of liquid shift (for ease of observation) and abruptness of the shift (for accurate determination of critical contact angle). The experimental results support the classical concept of macroscopic contact angle and demonstrate the role of hysteresis in impeding orientation toward equilibrium.

  3. Control of Angular Intervals for Angle-Multiplexed Holographic Memory

    NASA Astrophysics Data System (ADS)

    Kinoshita, Nobuhiro; Muroi, Tetsuhiko; Ishii, Norihiko; Kamijo, Koji; Shimidzu, Naoki

    2009-03-01

    In angle-multiplexed holographic memory, the full width at half maximum of the Bragg selectivity curves is dependent on the angle formed between the medium and incident laser beams. This indicates the possibility of high density and high multiplexing number by varying the angular intervals between adjacent holograms. We propose an angular interval scheduling for closely stacking holograms into medium even when the angle range is limited. We obtained bit error rates of the order of 10-4 under the following conditions: medium thickness of 1 mm, laser beam wavelength of 532 nm, and angular multiplexing number of 300.

  4. Bounded-Angle Iterative Decoding of LDPC Codes

    NASA Technical Reports Server (NTRS)

    Dolinar, Samuel; Andrews, Kenneth; Pollara, Fabrizio; Divsalar, Dariush

    2009-01-01

    Bounded-angle iterative decoding is a modified version of conventional iterative decoding, conceived as a means of reducing undetected-error rates for short low-density parity-check (LDPC) codes. For a given code, bounded-angle iterative decoding can be implemented by means of a simple modification of the decoder algorithm, without redesigning the code. Bounded-angle iterative decoding is based on a representation of received words and code words as vectors in an n-dimensional Euclidean space (where n is an integer).

  5. Remote logo detection using angle-distance histograms

    NASA Astrophysics Data System (ADS)

    Youn, Sungwook; Ok, Jiheon; Baek, Sangwook; Woo, Seongyoun; Lee, Chulhee

    2016-05-01

    Among all the various computer vision applications, automatic logo recognition has drawn great interest from industry as well as various academic institutions. In this paper, we propose an angle-distance map, which we used to develop a robust logo detection algorithm. The proposed angle-distance histogram is invariant against scale and rotation. The proposed method first used shape information and color characteristics to find the candidate regions and then applied the angle-distance histogram. Experiments show that the proposed method detected logos of various sizes and orientations.

  6. Measurement of critical contact angle in a microgravity space experiment

    SciTech Connect

    Concus, P.; Finn, R.; Weislogel, M.

    1999-06-01

    Mathematical theory predicts that small changes in container shape or in contact angle can give rise to large shifts of liquid in a microgravity environment. This phenomenon was investigated in the Interface Configuration Experiment on board the NASA USML-2 Space Shuttle flight. The experiment's double proboscis containers were designed to strike a balance between conflicting requirements of sizable volume of liquid shift (for ease of observation) and abruptness of the shift (for accurate determination of critical contact angle). The experimental results support the classical concept of macroscopic contact angle and demonstrate the role of hysteresis in impeding orientation toward equilibrium.

  7. The correlation between calcaneal valgus angle and asymmetrical thoracic-lumbar rotation angles in patients with adolescent scoliosis.

    PubMed

    Park, Jaeyong; Lee, Sang Gil; Bae, Jongjin; Lee, Jung Chul

    2015-12-01

    [Purpose] This study aimed to provide a predictable evaluation method for the progression of scoliosis in adolescents based on quick and reliable measurements using the naked eye, such as the calcaneal valgus angle of the foot, which can be performed at public facilities such as schools. [Subjects and Methods] Idiopathic scoliosis patients with a Cobb's angle of 10° or more (96 females, 22 males) were included in this study. To identify relationships between factors, Pearson's product-moment correlation coefficient was computed. The degree of scoliosis was set as a dependent variable to predict thoracic and lumbar scoliosis using ankle angle and physique factors. Height, weight, and left and right calcaneal valgus angles were set as independent variables; thereafter, multiple regression analysis was performed. This study extracted variables at a significance level (α) of 0.05 by applying a stepwise method, and calculated a regression equation. [Results] Negative correlation (R=-0.266) was shown between lumbar lordosis and asymmetrical lumbar rotation angles. A correlation (R=0.281) was also demonstrated between left calcaneal valgus angles and asymmetrical thoracic rotation angles. [Conclusion] Prediction of scoliosis progress was revealed to be possible through ocular inspection of the calcaneus and Adams forward bending test and the use of a scoliometer.

  8. The correlation between calcaneal valgus angle and asymmetrical thoracic-lumbar rotation angles in patients with adolescent scoliosis

    PubMed Central

    Park, Jaeyong; Lee, Sang Gil; Bae, Jongjin; Lee, Jung Chul

    2015-01-01

    [Purpose] This study aimed to provide a predictable evaluation method for the progression of scoliosis in adolescents based on quick and reliable measurements using the naked eye, such as the calcaneal valgus angle of the foot, which can be performed at public facilities such as schools. [Subjects and Methods] Idiopathic scoliosis patients with a Cobb’s angle of 10° or more (96 females, 22 males) were included in this study. To identify relationships between factors, Pearson’s product-moment correlation coefficient was computed. The degree of scoliosis was set as a dependent variable to predict thoracic and lumbar scoliosis using ankle angle and physique factors. Height, weight, and left and right calcaneal valgus angles were set as independent variables; thereafter, multiple regression analysis was performed. This study extracted variables at a significance level (α) of 0.05 by applying a stepwise method, and calculated a regression equation. [Results] Negative correlation (R=−0.266) was shown between lumbar lordosis and asymmetrical lumbar rotation angles. A correlation (R=0.281) was also demonstrated between left calcaneal valgus angles and asymmetrical thoracic rotation angles. [Conclusion] Prediction of scoliosis progress was revealed to be possible through ocular inspection of the calcaneus and Adams forward bending test and the use of a scoliometer. PMID:26834376

  9. The correlation between calcaneal valgus angle and asymmetrical thoracic-lumbar rotation angles in patients with adolescent scoliosis.

    PubMed

    Park, Jaeyong; Lee, Sang Gil; Bae, Jongjin; Lee, Jung Chul

    2015-12-01

    [Purpose] This study aimed to provide a predictable evaluation method for the progression of scoliosis in adolescents based on quick and reliable measurements using the naked eye, such as the calcaneal valgus angle of the foot, which can be performed at public facilities such as schools. [Subjects and Methods] Idiopathic scoliosis patients with a Cobb's angle of 10° or more (96 females, 22 males) were included in this study. To identify relationships between factors, Pearson's product-moment correlation coefficient was computed. The degree of scoliosis was set as a dependent variable to predict thoracic and lumbar scoliosis using ankle angle and physique factors. Height, weight, and left and right calcaneal valgus angles were set as independent variables; thereafter, multiple regression analysis was performed. This study extracted variables at a significance level (α) of 0.05 by applying a stepwise method, and calculated a regression equation. [Results] Negative correlation (R=-0.266) was shown between lumbar lordosis and asymmetrical lumbar rotation angles. A correlation (R=0.281) was also demonstrated between left calcaneal valgus angles and asymmetrical thoracic rotation angles. [Conclusion] Prediction of scoliosis progress was revealed to be possible through ocular inspection of the calcaneus and Adams forward bending test and the use of a scoliometer. PMID:26834376

  10. SU-E-I-56: Scan Angle Reduction for a Limited-Angle Intrafraction Verification (LIVE) System

    SciTech Connect

    Ren, L; Zhang, Y; Yin, F

    2014-06-01

    Purpose: To develop a novel adaptive reconstruction strategy to further reduce the scanning angle required by the limited-angle intrafraction verification (LIVE) system for intrafraction verification. Methods: LIVE acquires limited angle MV projections from the exit fluence of the arc treatment beam or during gantry rotation between static beams. Orthogonal limited-angle kV projections are also acquired simultaneously to provide additional information. LIVE considers the on-board 4D-CBCT images as a deformation of the prior 4D-CT images, and solves the deformation field based on deformation models and data fidelity constraint. LIVE reaches a checkpoint after a limited-angle scan, and reconstructs 4D-CBCT for intrafraction verification at the checkpoint. In adaptive reconstruction strategy, a larger scanning angle of 30° is used for the first checkpoint, and smaller scanning angles of 15° are used for subsequent checkpoints. The onboard images reconstructed at the previous adjacent checkpoint are used as the prior images for reconstruction at the current checkpoint. As the algorithm only needs to reconstruct the small deformation occurred between adjacent checkpoints, projections from a smaller scan angle provide enough information for the reconstruction. XCAT was used to simulate tumor motion baseline drift of 2mm along sup-inf direction at every subsequent checkpoint, which are 15° apart. Adaptive reconstruction strategy was used to reconstruct the images at each checkpoint using orthogonal 15° kV and MV projections. Results: Results showed that LIVE reconstructed the tumor volumes accurately using orthogonal 15° kV-MV projections. Volume percentage differences (VPDs) were within 5% and center of mass shifts (COMS) were within 1mm for reconstruction at all checkpoints. Conclusion: It's feasible to use an adaptive reconstruction strategy to further reduce the scan angle needed by LIVE to allow faster and more frequent intrafraction verification to minimize the

  11. Combined effects of the in-plane orientation angle and the loading angle on the dynamic enhancement of honeycombs under mixed shear-compression loading

    NASA Astrophysics Data System (ADS)

    Tounsi, R.; Markiewicz, E.; Haugou, G.; Chaari, F.; Zouari, B.

    2016-05-01

    The combined effect of the loading angle (ψ) and the in-plane orientation angle (β) on the dynamic enhancement of aluminium alloy honeycombs is investigated. Experimental results are analysed on the crushing surfaces (initial peak and average crushing forces). A significant effect of the loading angle is reported. The dynamic enhancement rate depends on the loading angle until a critical loading angle (ψcritical). Beyond, a negative dynamic enhancement rate is observed. Concerning the in-plane orientation angle β effect, it depends on the loading angle ψ under quasi-static conditions. Under dynamic conditions, a significant effect is reported independently of the loading angle ψ. Therefore, the dynamic enhancement rate depends on the combined effects of ψ and β angles. A global analysis of the buckling mechanisms allowed us to explain the combined effect of ψ and β angles on the initial peak force. The collapse mechanisms analysis explain the negative dynamic enhancement rate for large loading angles.

  12. Adaptive control of a vibratory angle measuring gyroscope.

    PubMed

    Park, Sungsu

    2010-01-01

    This paper presents an adaptive control algorithm for realizing a vibratory angle measuring gyroscope so that rotation angle can be directly measured without integration of angular rate, thus eliminating the accumulation of numerical integration errors. The proposed control algorithm uses a trajectory following approach and the reference trajectory is generated by an ideal angle measuring gyroscope driven by the estimate of angular rate and the auxiliary sinusoidal input so that the persistent excitation condition is satisfied. The developed control algorithm can compensate for all types of fabrication imperfections such as coupled damping and stiffness, and mismatched stiffness and un-equal damping term in an on-line fashion. The simulation results show the feasibility and effectiveness of the developed control algorithm that is capable of directly measuring rotation angle without the integration of angular rate.

  13. Role of Pitch Angle Anisotropy in Ring Current Electrodynamics

    NASA Astrophysics Data System (ADS)

    Wan, Y.; Sazykin, S.; Fok, M. H.; Buzulukova, N.; Wolf, R.

    2009-12-01

    We quantitatively investigate the degree to which the basic characteristics of the injection of a storm-time ring current depend on the pitch-angle distribution. The investigation centers on a comparison of two simulations of the August 12, 2000 storm: one based on the Rice Convection Model (RCM), which assumes an isotropic pitch angle distribution, and the other on the Comprehensive Ring Current Model (CRCM), which calculates the pitch angle distribution in detail. Results from the two runs are compared with regard to the main-phase increase in the energy in ring current particles, the strength and distribution of the region-2 currents, and the strength and pattern of the prompt-penetration electric field. We also compare the recovery phase characteristics predicted by the CRCM, which carefully calculates the changes in pitch-angle distribution as charge exchange proceeds, and the RCM, which uses a much simpler way of estimating charge-exchange loss.

  14. First statistics of the isopistonic angle for long baseline interferometry

    NASA Astrophysics Data System (ADS)

    Ziad, A.; Elhalkouj, T.; Petrov, R. G.; Borgnino, J.; Lazrek, M.; Benkhaldoun, Z.; Martin, F.; Elazhari, Y.

    2016-06-01

    To reach a suitable limiting magnitude with a multi-aperture interferometer, we need to cophase the different telescopes using a reference source. The latter should be located in the same isopistonic domain as the science source. We developed a direct analytical expression of deducing the isopistonic angle from atmospheric optical parameters as seeing, isoplanatic angle and outer scale. All of these atmospheric turbulence parameters are measured by the Generalized Seeing Monitor (GSM). The first statistics of the isopistonic angle obtained from the GSM data are presented and comparison between the major sites over the world are discussed (La Silla, Cerro Pachon, Paranal, San Pedro, Mt Palomar, Mauna Kea, La Palma, Oukaïmeden, Maydanak, Dome C). Implications of these isopistonic angle statistics on large interferometers cophasing in terms of sky coverage and limiting magnitude are discussed.

  15. Dataglove measurement of joint angles in sign language handshapes

    PubMed Central

    Eccarius, Petra; Bour, Rebecca; Scheidt, Robert A.

    2012-01-01

    In sign language research, we understand little about articulatory factors involved in shaping phonemic boundaries or the amount (and articulatory nature) of acceptable phonetic variation between handshapes. To date, there exists no comprehensive analysis of handshape based on the quantitative measurement of joint angles during sign production. The purpose of our work is to develop a methodology for collecting and visualizing quantitative handshape data in an attempt to better understand how handshapes are produced at a phonetic level. In this pursuit, we seek to quantify the flexion and abduction angles of the finger joints using a commercial data glove (CyberGlove; Immersion Inc.). We present calibration procedures used to convert raw glove signals into joint angles. We then implement those procedures and evaluate their ability to accurately predict joint angle. Finally, we provide examples of how our recording techniques might inform current research questions. PMID:23997644

  16. 54. Angled view looking up at Brooklyn Tower showing juncture ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    54. Angled view looking up at Brooklyn Tower showing juncture of deck superstructure with the tower and diagonal cables. Jet Lowe, photographer, 1982. - Brooklyn Bridge, Spanning East River between Park Row, Manhattan and Sands Street, Brooklyn, New York County, NY

  17. 62. Ground level, angled view looking SE at Brooklyn anchorage ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    62. Ground level, angled view looking SE at Brooklyn anchorage and side span superstructure. Jet Lowe, photographer, 1982. - Brooklyn Bridge, Spanning East River between Park Row, Manhattan and Sands Street, Brooklyn, New York County, NY

  18. SMALL ANGLE CRAB COMPENSATION FOR LHC IR UPGRADE

    SciTech Connect

    CALAGA,R.; DORDA, U.; OHMI, D.; OIDE, K.; TOMAS, R.; ZIMMERMANN, F.

    2007-06-25

    A small angle (< 1 mrad) crab scheme is an attractive option for the LHC luminosity upgrade to recover the geometric luminosity loss from the finite crossing angle [I]. The luminosity loss increases steeply to unacceptable levels as the IP beta function is reduced below its nominal value (see Fig. 1 in Ref. [2]). The crab compensation in the LHC can be accomplished using only two sets of deflecting RF cavities, placed in collision-free straight sections of the LHC to nullify the effective crossing angles at IPI & IP5. We also explore a 400 MHz superconducting cavity design and discuss the pertinent RF challenges. We present IR optics configurations with low-angle crab crossing, study the beam-beam performance and proton-beam emittance growth in the presence of crab compensation, lattice errors, and crab RF noise sources.

  19. 38. DETAIL AERIAL VIEW LOOKING SOUTHEAST AT 45 DEGREE ANGLE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    38. DETAIL AERIAL VIEW LOOKING SOUTHEAST AT 45 DEGREE ANGLE SHOWING TOP VIEW OF 210' 9' LIFT SPAN - Central Railroad of New Jersey, Newark Bay Lift Bridge, Spanning Newark Bay, Newark, Essex County, NJ

  20. 6. ANGLE VIEW OF ABANDONED INCINERATOR, INTERIOR OF BUILDING, 499 ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    6. ANGLE VIEW OF ABANDONED INCINERATOR, INTERIOR OF BUILDING, 499 FACING NORTHWEST. - U.S. Naval Base, Pearl Harbor, Fleet Accounting & Dispersing Center, 178 Main Street, Pearl City, Honolulu County, HI

  1. Uncertainty Relation between Angular Momentum and Angle Variable.

    ERIC Educational Resources Information Center

    Roy, C. L.; Sannigrahi, A. B.

    1979-01-01

    Discusses certain pitfalls regarding the uncertainty relation between angular momentum and the angle variable from a pedagogic point of view. Further, an uncertainty relation has been derived for these variables in a simple and consistant manner. (Author/HM)

  2. Wigner Distribution for Angle Coordinates in Quantum Mechanics.

    ERIC Educational Resources Information Center

    Mukunda, N.

    1979-01-01

    Shows how to extend Wigner distribution functions, and Weyl correspondence between quantum and classical variables, from the usual kind of canonically conjugate position and momentum operators to the case of an angle and angular momentum operator pair. (Author/GA)

  3. Supersonic flow around circular cones at angles of attack

    NASA Technical Reports Server (NTRS)

    Ferri, Antonio

    1951-01-01

    The properties of conical flow without axial symmetry are analyzed. The flow around cones of circular cross section at small angles of attack is determined by correctly considering the effect of the entropy gradients in the flow.

  4. On Ruby's solid angle formula and some of its generalizations

    NASA Astrophysics Data System (ADS)

    Friot, Samuel

    2015-02-01

    Using the Mellin-Barnes representation, we show that Ruby's solid angle formula and some of its generalizations may be expressed in a compact way in terms of the Appell F4 and Lauricella FC functions.

  5. (wide angle) view of the west elevation of the ballroom, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    (wide angle) view of the west elevation of the ballroom, including Swiss Chalet (left) and Pagoda (right), with scale - National Park Seminary, Bounded by Capitol Beltway (I-495), Linden Lane, Woodstove Avenue, & Smith Drive, Silver Spring, Montgomery County, MD

  6. Wing-alone aerodynamic characteristics at high angles of attack

    NASA Technical Reports Server (NTRS)

    Stallings, R. L., Jr.; Lamb, M.

    1981-01-01

    An experimental investigation has been conducted to determine wing-alone supersonic aerodynamic characteristics at high angles of attack. The family of wings tested varied in aspect ratio from 0.5 to 4.0 and taper ratio from 0.0 to 1.0. The wings were tested at angles of attack ranging from 0 to 60 deg and Mach numbers from 1.6 to 4.6. The aerodynamic characteristics were obtained by integrating local pressures measured over the wing surface. Comparison of these data with the limited available data from the literature indicate the present data are free of sting interference effects through the test range of angle of attack. Presented and discussed are results showing the effects of model geometry, Mach number and angle of attack on aerodynamic characteristics consisting of normal force, pitching moment, bending moment, longitudinal center-of-pressure locations, and lateral center-of-pressure locations.

  7. 14. DETAIL OF GUSSET WITH CURVE ANGLE IRON AND TWISTED ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    14. DETAIL OF GUSSET WITH CURVE ANGLE IRON AND TWISTED STRIPS, FORMING SUN RAY PATTERN. LATTICE RAILING AT LOWER RIGHT. - River Road Bridge, Spanning Spring Creek in Spring Creek Township, Hallton, Elk County, PA

  8. 6. DETAIL OF GUSSET WITH CURVE ANGLE IRON AND TWISTED ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    6. DETAIL OF GUSSET WITH CURVE ANGLE IRON AND TWISTED STRIPS, FORMING SUN RAY PATTERN. LATTICE RAILING AT LOWER RIGHT. - River Road Bridge, Spanning Spring Creek in Spring Creek Township, Hallton, Elk County, PA

  9. Report on APMP key comparison: calibration of angle standards

    NASA Astrophysics Data System (ADS)

    Kang, C.-S.; Kruger, O. A.; Cox, P.; Xue, Z.; Liou, P.; Wong, S. Y.; Chaudhary, K. P.; Alfiyati, N.; Watanabe, T.; Eom, T.; Halim, R. M.; Tan, S. L.; Tonmueanwai, A.; Dibo, M.

    2016-01-01

    A regional key comparison, APMP.L-K3 (calibration of angle standards) was held in 2005. Thirteen National Metrology Institutes (NMISA, NMIA, KRISS, NMIJ/ AIST, NMC/ A*STAR, NIMT, SCL, CMS/ ITRI, NPLI, RCM- LIPI, NIM, and NSCL) have participated in this comparison and the measurements were carried out during the period from April 2005 to December 2007. This report describes the measurement results of a 12-sided optical polygon with nominal angles of 30°, and four angle blocks with nominal angles of 5 arc seconds, 5 minutes, 30 minutes and 5 degrees, respectively. Main text To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCL, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

  10. 3. WIDE ANGLE OF NEUTRAL BUOYANCY SIMULATOR (NBS) FROM WITHIN ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    3. WIDE ANGLE OF NEUTRAL BUOYANCY SIMULATOR (NBS) FROM WITHIN NBS HIGHBAY DOORS. DIVE BELL IN FOREGROUND. - Marshall Space Flight Center, Neutral Buoyancy Simulator Facility, Rideout Road, Huntsville, Madison County, AL

  11. ILC Extraction Line for 14 mrad Crossing Angle

    SciTech Connect

    Nosochkov, Y.; Markiewicz, T.; Maruyama, T.; Seryi, A.; Parker, B.; /Brookhaven

    2005-12-08

    The earlier studies of the ILC extraction line for 20 mrad and 2 mrad crossing angle options [1]-[5] showed that the 20 mrad design has an advantage of a simpler beamline and lower extraction beam loss because of the independent incoming and extraction optics. However, the large 20 mrad crossing angle requires the use of a crab cavity correction, increases synchrotron radiation emittance growth in the solenoid, and increases photon backscattering from the forward calorimeter of the detector. To reduce these effects, an attempt has been made to minimize the crossing angle while keeping the extraction and incoming lines separate. A new quadrupole scheme near the interaction point has been proposed which allows a reduction of the crossing angle to 14 mrad [6]. The optics design and results of tracking and background simulations for the 14 mrad extraction line are presented.

  12. Folded cavity angled-grating broad-area lasers.

    PubMed

    Zhao, Yunsong; Zhu, Lin

    2013-10-01

    The angled-grating broad-area laser is a promising candidate for high power, high brightness diode laser source. The key point in the design is the angled gratings which can simultaneously support the unique snake-like zigzag lasing mode and eliminate the direct Fabry-Perot (FP) feedback. Unlike a conventional laser waveguide mode, the phase front of the zigzag mode periodically changes along the propagation direction. By use of the mirror symmetry of the zigzag mode, we propose and demonstrate the folded cavity angled-grating broad-area lasers. One benefit of this design is to reduce the required wafer space compared to a regular angled-grating broad-area laser, especially in a long cavity laser for high power operation. Experimental results show that the folded cavity laser exhibits good beam quality in far field with a slightly larger threshold and smaller slope efficiency due to the additional interface loss.

  13. Stress the Local Angle...Keep the Yearbook Currently Eventful.

    ERIC Educational Resources Information Center

    Stano, Randy

    1980-01-01

    Suggests that while current events should be recorded in school yearbooks, the local angle should be stressed. Provides illustrations of how this might be done with such topics as gasoline prices, inflation, foreign events, and political campaigns. (TJ)

  14. 22. OBLIQUE WIDE ANGLE VIEW OF NORTH SIDE OF COOPER ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    22. OBLIQUE WIDE ANGLE VIEW OF NORTH SIDE OF COOPER RIVER SPAN FROM RANGE MARKER NEAR DRUM ISLAND, FACING SOUTHEAST - Grace Memorial Bridge, U.S. Highway 17 spanning Cooper River & Town Creek , Charleston, Charleston County, SC

  15. Asronomical refraction: Computational methods for all zenith angles

    NASA Technical Reports Server (NTRS)

    Auer, L. H.; Standish, E. M.

    2000-01-01

    It is shown that the problem of computing astronomical refraction for any value of the zenith angle may be reduced to a simple, nonsingular, numerical quadrature when the proper choice is made for the independent variable of integration.

  16. Perspective view of south portal. Note how portal angles about ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Perspective view of south portal. Note how portal angles about 5' forward over the approach. - Red Oak Creek Bridge, Spanning (Big) Red Oak Creek, Huel Brown Road (Covered Bridge Road), Woodbury, Meriwether County, GA

  17. Parameterization of ion channeling half-angles and minimum yields

    NASA Astrophysics Data System (ADS)

    Doyle, Barney L.

    2016-03-01

    A MS Excel program has been written that calculates ion channeling half-angles and minimum yields in cubic bcc, fcc and diamond lattice crystals. All of the tables and graphs in the three Ion Beam Analysis Handbooks that previously had to be manually looked up and read from were programed into Excel in handy lookup tables, or parameterized, for the case of the graphs, using rather simple exponential functions with different power functions of the arguments. The program then offers an extremely convenient way to calculate axial and planar half-angles, minimum yields, effects on half-angles and minimum yields of amorphous overlayers. The program can calculate these half-angles and minimum yields for axes and [h k l] planes up to (5 5 5). The program is open source and available at

  18. 18. DRAWING NO. 26 TITLED 'ANGLE LATTICE STRUTS AND KNEE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    18. DRAWING NO. 26 TITLED 'ANGLE LATTICE STRUTS AND KNEE BRACES,' DATED APRIL 2, 1903 - Mahoning Avenue Pratt Double-Deck Bridge, Spanning Mill Creek at Mahoning Avenue (C.R. 319), Youngstown, Mahoning County, OH

  19. Design of an all-attitude flight control system to execute commanded bank angles and angles of attack

    NASA Technical Reports Server (NTRS)

    Burgin, G. H.; Eggleston, D. M.

    1976-01-01

    A flight control system for use in air-to-air combat simulation was designed. The input to the flight control system are commanded bank angle and angle of attack, the output are commands to the control surface actuators such that the commanded values will be achieved in near minimum time and sideslip is controlled to remain small. For the longitudinal direction, a conventional linear control system with gains scheduled as a function of dynamic pressure is employed. For the lateral direction, a novel control system, consisting of a linear portion for small bank angle errors and a bang-bang control system for large errors and error rates is employed.

  20. Pitch angle scattering of energetic particles by oblique whistler waves

    NASA Technical Reports Server (NTRS)

    Inan, U. S.; Bell, T. F.

    1991-01-01

    First order cyclotron or Landau resonant pitch angle scattering of electrons by oblique whistler waves propagating at large angles to the ambient field are found to be at least as large as that due to parallel propagating waves. Commonly observed precipitation of more than 40 keV electrons in association with ducted whistlers may thus be accompanied by substantial fluxes of lower energy (10 eV-40 keV) electrons precipitated by the nonducted components.

  1. Photovoltaic Modules: Effect of Tilt Angle on Soiling

    NASA Astrophysics Data System (ADS)

    Cano, Jose

    2011-12-01

    Photovoltaic (PV) systems are one of the next generation's renewable energy sources for our world energy demand. PV modules are highly reliable. However, in polluted environments, over time, they will collect grime and dust. There are also limited field data studies about soiling losses on PV modules. The study showed how important it is to investigate the effect of tilt angle on soiling. The study includes two sets of mini-modules. Each set has 9 PV modules tilted at 0, 5, 10, 15, 20, 23, 30, 33 and 40°. The first set called "Cleaned" was cleaned every other day. The second set called "Soiled" was never cleaned after the first day. The short circuit current, a measure of irradiance, and module temperature was monitored and recorded every two minutes over three months (January-March 2011). The data were analyzed to investigate the effect of tilt angle on daily and monthly soiling, and hence transmitted solar insolation and energy production by PV modules. The study shows that during the period of January through March 2011 there was an average loss due to soiling of approximately 2.02% for 0° tilt angle. Modules at tilt angles 23° and 33° also have some insolation losses but do not come close to the module at 0° tilt angle. Tilt angle 23° has approximately 1.05% monthly insolation loss, and 33° tilt angle has an insolation loss of approximately 0.96%. The soiling effect is present at any tilt angle, but the magnitude is evident: the flatter the solar module is placed the more energy it will lose.

  2. Measurement of the angle of superficial tension by images

    NASA Astrophysics Data System (ADS)

    Yanez M., Javier; Alonso R., Sergio

    2006-02-01

    When a liquid is deposited on a surface, this one form a certain angle with respect to the surface, where depending on its value, it will conclude that so hard it is his adhesion with the surface. By means of the analysis of images we looked for to measure this angle of superficial tension. In order to make this measurement, we propose a technique by means of projective transformations and one method of regression to estimation parameters to conic fitting.

  3. A system concept for wide swath constant incident angle coverage

    NASA Technical Reports Server (NTRS)

    Claassen, J. P.; Eckerman, J.

    1978-01-01

    Multiple beam approach readily overcomes radar ambiguity constraints associated with orbital systems and therefore permits imagery over swaths much wider than 100 kilometers. Furthermore, the antenna technique permits imagery at nearly constant incident angles. When frequency scanning is employed, the center angle may be programmed. The redundant use of the antenna aperture during reception results in lower transmitted power and in shorter antenna lengths in comparison to conventional designs. Compatibility of the approach with passive imagery is also considered.

  4. Light Airplane Crash Test at Three Pitch Angles

    NASA Technical Reports Server (NTRS)

    Vaughan, Victor L., Jr.; Alfaro-Bou, Emilio

    1979-01-01

    Three similar twin-engine general-aviation airplane specimens were crash tested at the Langley Impact Dynamics Research Facility at 27 m/sec, a flight-path angle of -15deg, and pithch angles of -15deg, 0deg, and 15deg. Other crash parameters were held constant. The test facility, instrumentation, test specimens, and test method are briefly described. Structural damage and accelerometer data for each of the three impact conditions are presented and discussed.

  5. Comparison of different passive knee extension torque-angle assessments.

    PubMed

    Freitas, Sandro R; Vaz, João R; Bruno, Paula M; Valamatos, Maria J; Mil-Homens, Pedro

    2013-11-01

    Previous studies have used isokinetic dynamometry to assess joint torques and angles during passive extension of the knee, often without reporting upon methodological errors and reliability outcomes. In addition, the reliability of the techniques used to measure passive knee extension torque-angle and the extent to which reliability may be affected by the position of the subjects is also unclear. Therefore, we conducted an analysis of the intra- and inter-session reliability of two methods of assessing passive knee extension: (A) a 2D kinematic analysis coupled to a custom-made device that enabled the direct measurement of resistance to stretch and (B) an isokinetic dynamometer used in two testing positions (with the non-tested thigh either flexed at 45° or in the neutral position). The intra-class correlation coefficients (ICCs) of torque, the slope of the torque-angle curve, and the parameters of the mathematical model that were fit to the torque-angle data for the above conditions were measured in sixteen healthy male subjects (age: 21.4 ± 2.1 yr; BMI: 22.6 ± 3.3 kg m(-2); tibial length: 37.4 ± 3.4 cm). The results found were: (1) methods A and B led to distinctly different torque-angle responses; (2) passive torque-angle relationship and stretch tolerance were influenced by the position of the non-tested thigh; and (3) ICCs obtained for torque were higher than for the slope and for the mathematical parameters that were fit to the torque-angle curve. In conclusion, the measurement method that is used and the positioning of subjects can influence the passive knee extension torque-angle outcome.

  6. 2DFFT: Measuring Galactic Spiral Arm Pitch Angle

    NASA Astrophysics Data System (ADS)

    Davis, Benjamin L.; Berrier, Joel C.; Shields, Douglas W.; Kennefick, Julia; Kennefick, Daniel; Seigar, Marc S.; Lacy, Claud H. S.; Puerari, Ivânio

    2016-08-01

    2DFFT utilizes two-dimensional fast Fourier transformations of images of spiral galaxies to isolate and measure the pitch angles of their spiral arms; this provides a quantitative way to measure this morphological feature and allows comparison of spiral galaxy pitch angle to other galactic parameters and test spiral arm genesis theories. 2DFFT requires fourn.c from Numerical Recipes in C (Press et al. 1989).

  7. Predicting bed form roughness: the influence of lee side angle

    NASA Astrophysics Data System (ADS)

    Lefebvre, Alice; Winter, Christian

    2016-04-01

    Flow transverse bedforms (ripples and dunes) are ubiquitous in rivers and coastal seas. Local hydrodynamics and transport conditions depend on the size and geometry of these bedforms, as they constitute roughness elements at the bed. Bedform influence on flow energy must be considered for the understanding of flow dynamics, and in the development and application of numerical models. Common estimations or predictors of form roughness (friction factors) are based mostly on data of steep bedforms (with angle-of-repose lee slopes), and described by highly simplified bedform dimensions (heights and lengths). However, natural bedforms often are not steep, and differ in form and hydraulic effect relative to idealised bedforms. Based on systematic numerical model experiments, this study shows how the hydraulic effect of bedforms depends on the flow structure behind bedforms, which is determined by the bedform lee side angle, aspect ratio and relative height. Simulations reveal that flow separation behind bedform crests and, thus, a hydraulic effect is induced at lee side angles steeper than 11 to 18° depending on relative height, and that a fully developed flow separation zone exists only over bedforms with a lee side angle steeper than 24°. Furthermore, the hydraulic effect of bedforms with varying lee side angle is evaluated and a reduction function to common friction factors is proposed. A function is also developed for the Nikuradse roughness (k s), and a new equation is proposed which directly relates k s to bedform relative height, aspect ratio and lee side angle.

  8. A Universal Formula for Extracting the Euler Angles

    NASA Technical Reports Server (NTRS)

    Shuster, Malcolm D.; Markley, F. Landis

    2004-01-01

    Recently, the authors completed a study of the Davenport angles, which are a generalization of the Euler angles for which the initial and final Euler axes need not be either mutually parallel or mutually perpendicular or even along the coordinate axes. During the conduct of that study, those authors discovered a relationship which can be used to compute straightforwardly the Euler angles characterizing a proper-orthogonal direction-cosine matrix for an arbitrary Euler-axis set satisfying n(sub 1) x n(sub 2) = 0 and n(sub 3) x n(sub 1) = 0, which is also satisfied by the more usual Euler angles we encounter commonly in the practice of Astronautics. Rather than leave that relationship hidden in an article with very different focus from the present Engineering note, we present it and the universal algorithm derived from it for extracting the Euler angles from the direction-cosine matrix here. We also offer literal "code" for performing the operations, numerical examples, and general considerations about the extraction of Euler angles which are not universally known, particularly, the treatment of statistical error.

  9. Angle of Attack Modulation for Mars Entry Terminal State Optimization

    NASA Technical Reports Server (NTRS)

    Lafleur, Jarret M.; Cerimele, Christopher J.

    2009-01-01

    From the perspective of atmospheric entry, descent, and landing (EDL), one of the most foreboding destinations in the solar system is Mars due in part to its exceedingly thin atmosphere. To benchmark best possible scenarios for evaluation of potential Mars EDL system designs, a study is conducted to optimize the entry-to-terminal-state portion of EDL for a variety of entry velocities and vehicle masses, focusing on the identification of potential benefits of enabling angle of attack modulation. The terminal state is envisioned as one appropriate for the initiation of terminal descent via parachute or other means. A particle swarm optimizer varies entry flight path angle, ten bank profile points, and ten angle of attack profile points to find maximum-final-altitude trajectories for a 10 30 m ellipsled at 180 different combinations of values for entry mass, entry velocity, terminal Mach number, and minimum allowable altitude. Parametric plots of maximum achievable altitude are shown, as are examples of optimized trajectories. It is shown that appreciable terminal state altitude gains (2.5-4.0 km) over pure bank angle control may be possible if angle of attack modulation is enabled for Mars entry vehicles. Gains of this magnitude could prove to be enabling for missions requiring high-altitude landing sites. Conclusions are also drawn regarding trends in the bank and angle of attack profiles that produce the optimal trajectories in this study, and directions for future work are identified.

  10. Influence of Different Diffuser Angle on Sedan's Aerodynamic Characteristics

    NASA Astrophysics Data System (ADS)

    Hu, Xingjun; Zhang, Rui; Ye, Jian; Yan, Xu; Zhao, Zhiming

    The aerodynamic characteristics have a great influence on the fuel economics and the steering stability of a high speed vehicle. The underbody rear diffuser is one of important aerodynamic add-on devices. The parameters of the diffuser, including the diffuser angle, the number and the shape of separators, the shape of the end plate and etc, will affect the underbody flow and the wake. Here, just the influence of the diffuser angle was investigated without separator and the end plate. The method of Computational Fluid Dynamics was adopted to study the aerodynamic characteristics of a simplified sedan with a different diffuser angle respectively. The diffuser angle was set to 0°, 3°, 6°, 9.8° and 12° respectively. The diffuser angle of the original model is 9.8°. The conclusions were drawn that when the diffuser angle increases, the underbody flow and especially the wake change greatly and the pressure change correspondingly; as a result, the total aerodynamic drag coefficients of car first decrease and then increases, while the total aerodynamic lift coefficients decrease.

  11. Method for producing angled optical fiber tips in the laboratory

    NASA Astrophysics Data System (ADS)

    Davenport, John J.; Hickey, Michelle; Phillips, Justin P.; Kyriacou, Panicos A.

    2016-02-01

    A simple laboratory method is presented for producing optical fibers with tips polished at various angles. Angled optical fiber tips are used in applications such as optical sensing and remote laser surgery, where they can be used to control the angle of light leaving the fiber or direct it to the side. This allows for greater control and allows areas to be reached that otherwise could not. Optical fibers were produced with tip angles of 45 deg using a Perspex mounting block with an aluminum base plate. The dispersion of light leaving the tip was tested using a blue (470 nm) LED. The angle imposed an angular shift on the light diffracting out of the tip of approximately 30 deg. Additionally, some light reflected from the tip surface to diffract at 90 deg through the side of the fiber. These observations are consistent with theory and those seen by other studies, validating the method. The method was simple to perform and does not require advanced manufacturing tools. The method is suitable for producing small quantities of angle-tipped optical fibers for research applications.

  12. Determination of the Contact Angle Based on the Casimir Effect

    NASA Technical Reports Server (NTRS)

    Mazuruk, K.; Volz, M. P.

    2015-01-01

    In several crystal growth processed based on capillarity, a melt comes into contact with a crucible wall at an angle defined as the contact angle. For molten metals and semiconductors, this contact angle is dependent upon both the crucible and melt material and typical values fall in the range 80-170deg. However, on a microscopic scale, there does not exist a precise and sharp contact angle but rather the melt and solid surfaces merge smoothly and continuously over a distance of up to several micrometers. Accurate modeling requires a more advanced treatment of this interaction. The interaction between the melt and solid surfaces can be calculated by considering two forces: a short-range repulsive force and a longer range (up to a few micrometers) Casimir force. The Casimir force between the two bodies of complex geometry is calculated using a retarded temperature Green's function (Matsubara type) for the photon in the medium. The governing equations are cast in the form of a set of boundary integral equations which are then solved numerically for the case of molten Ge on SiO2. The shape of the molten surface approaching the flat solid body is determined, and the contact angle is defined as the angle between the two surfaces at the microscopically asymptotic distance of 1-2 micrometers. The formulation of this model and the results of the numerical calculations will be presented and discussed.

  13. Static and Dynamic Contact Angles of Immersed Ferrofluid Droplets

    NASA Astrophysics Data System (ADS)

    Chatterjee, Souvick; Bhowmik, Dipanwita; Mukhopadhyay, Achintya; Ganguly, Ranjan

    2013-11-01

    Ferrofluid plug driven micro-pumps are useful for manipulating micro-volume of liquids by providing remote actuation using a localized magnetic field gradient. Inside a microchannel, the ferrofluid experiences combined actions of different relevant body forces. While the pressure, viscous and magnetic forces can be estimated using established techniques, the surface tension force requires information about the contact angle between the ferrofluid and glass capillary wall. We address this phenomenon through experimental characterization of static and dynamic contact angles of oil based ferrofluid (EFH3) droplets on glass surface immersed in pure or surfacted distilled water. The equilibrium static contact angle is found to significantly reduce in presence of a magnetic field. Dynamic contact angles are measured through high-speed imaging as the ferrofluid droplets slide along an inclined glass surface. Variation of contact angle hysteresis, which falls outside the Hoffmann Tanner equation for this case, is also investigated as a function of contact line velocity. A strong dependence is found between the contact angle hysteresis and the wetting time. Findings of the work is useful for designing ferrofluid plug-driven microfluidic plugs for different lab-on-a-chip applications.

  14. Viewing angle controllable liquid crystal display with high transmittance.

    PubMed

    Lim, Young Jin; Kim, Jin Ho; Her, Jung Hwa; Bhattacharyya, Surjya Sarathi; Park, Kyoung Ho; Lee, Joun Ho; Kim, Byeong Koo; Lee, Seung Hee

    2010-03-29

    All conventional viewing angle switchable liquid crystal displays with pixel division have drawback in light efficiency because the sub-pixel that controls viewing angle does not transmit the incident light at normal direction. In this paper, we propose new viewing angle controllable homogeneously aligned liquid crystal display in which the pixel is composed of red, green, blue, and white pixels. The colored pixels are driven by fringe-field switching and the white pixel is driven by complex field. In wide-viewing angle mode, the liquid crystal (LC) directors in all pixels rotate in plane, contributing to high transmittance. In narrow-viewing angle mode, the LC directors in color pixels rotate in plane for light transmission while the LC directors in white pixel can rotate or tilt upward by simultaneous fringe and vertical electric field. The high tilted LC directors generate light leakage in oblique directions which can be utilized for viewing angle control and also transmission at normal direction for image expression. The proposed device overcomes the long standing problem of transmittance sacrifice in the conventional devices.

  15. The response of spit shapes to wave-angle climates

    USGS Publications Warehouse

    Ashton, A.D.; Murray, A.B.; Littlewood, R.

    2007-01-01

    We investigate spit formation and evolution in light of the high-wave-angle instability in shoreline shape arising from a maximizing angle for wave-driven alongshore sediment transport. Single spits emerge in a simple one-contour line numerical model that evolves the coast using morphodynamic feedbacks and a 'climate' of waves approaching the shore from variable directions. Analysis of sediment transport and shoreline stability metrics illustrate how spits can be generated, demonstrating how waves from all angles can play a role in spit formation and evolution. Simulations suggest that regardless of whether high- or low-angle waves dominate relative to the general shoreline trend, as spits extend offshore, they tend to orient themselves such that most of their coast barely experiences low-angle waves and alongshore sediment transport to the spit end is maximized. This 'graded' spit shape minimizes gradients in sediment flux, while the recurve at the spit end experiences larger gradients and a region of high-angle instability. Examining hindcast wave data, similar trends are seen along the natural example of Long Point, Lake Erie, Canada. ?? 2007 ASCE.

  16. Limbus Impact on Off-angle Iris Degradation

    SciTech Connect

    Karakaya, Mahmut; Barstow, Del R; Santos-Villalobos, Hector J; Thompson, Joseph W; Bolme, David S; Boehnen, Chris Bensing

    2013-01-01

    The accuracy of iris recognition depends on the quality of data capture and is negatively affected by several factors such as angle, occlusion, and dilation. Off-angle iris recognition is a new research focus in biometrics that tries to address several issues including corneal refraction, complex 3D iris texture, and blur. In this paper, we present an additional significant challenge that degrades the performance of the off-angle iris recognition systems, called the limbus effect . The limbus is the region at the border of the cornea where the cornea joins the sclera. The limbus is a semitransparent tissue that occludes a side portion of the iris plane. The amount of occluded iris texture on the side nearest the camera increases as the image acquisition angle increases. Without considering the role of the limbus effect, it is difficult to design an accurate off-angle iris recognition system. To the best of our knowledge, this is the first work that investigates the limbus effect in detail from a biometrics perspective. Based on results from real images and simulated experiments with real iris texture, the limbus effect increases the hamming distance score between frontal and off-angle iris images ranging from 0.05 to 0.2 depending upon the limbus height.

  17. Variable-angle high-angle annular dark-field imaging: application to three-dimensional dopant atom profiling.

    PubMed

    Zhang, Jack Y; Hwang, Jinwoo; Isaac, Brandon J; Stemmer, Susanne

    2015-07-24

    Variable-angle high-angle annular dark-field (HAADF) imaging in scanning transmission electron microscopy is developed for precise and accurate determination of three-dimensional (3D) dopant atom configurations. Gd-doped SrTiO3 films containing Sr columns containing zero, one, or two Gd dopant atoms are imaged in HAADF mode using two different collection angles. Variable-angle HAADF significantly increases both the precision and accuracy of 3D dopant profiling. Using image simulations, it is shown that the combined information from the two detectors reduces the uncertainty in the dopant depth position measurement and can uniquely identify certain atomic configurations that are indistinguishable with a single detector setting. Additional advances and applications are discussed.

  18. Influence of Contact Angle, Growth Angle and Melt Surface Tension on Detached Solidification of InSb

    NASA Technical Reports Server (NTRS)

    Wang, Yazhen; Regel, Liya L.; Wilcox, William R.

    2000-01-01

    We extended the previous analysis of detached solidification of InSb based on the moving meniscus model. We found that for steady detached solidification to occur in a sealed ampoule in zero gravity, it is necessary for the growth angle to exceed a critical value, the contact angle for the melt on the ampoule wall to exceed a critical value, and the melt-gas surface tension to be below a critical value. These critical values would depend on the material properties and the growth parameters. For the conditions examined here, the sum of the growth angle and the contact angle must exceed approximately 130, which is significantly less than required if both ends of the ampoule are open.

  19. Variable-angle high-angle annular dark-field imaging: application to three-dimensional dopant atom profiling

    PubMed Central

    Zhang, Jack Y.; Hwang, Jinwoo; Isaac, Brandon J.; Stemmer, Susanne

    2015-01-01

    Variable-angle high-angle annular dark-field (HAADF) imaging in scanning transmission electron microscopy is developed for precise and accurate determination of three-dimensional (3D) dopant atom configurations. Gd-doped SrTiO3 films containing Sr columns containing zero, one, or two Gd dopant atoms are imaged in HAADF mode using two different collection angles. Variable-angle HAADF significantly increases both the precision and accuracy of 3D dopant profiling. Using image simulations, it is shown that the combined information from the two detectors reduces the uncertainty in the dopant depth position measurement and can uniquely identify certain atomic configurations that are indistinguishable with a single detector setting. Additional advances and applications are discussed. PMID:26206489

  20. Straight ladder inclined angle in a field environment: the relationship among actual angle, method of set-up and knowledge

    PubMed Central

    Chang, Wen-Ruey; Huang, Yueng-Hsiang; Chang, Chien-Chi; Brunette, Christopher; Fallentin, Nils

    2016-01-01

    Abstract Ladder inclined angle is a critical factor that could lead to a slip at the base of portable straight ladders, a major cause of falls from heights. Despite several methods established to help workers achieve the recommended 75.5° angle for ladder set-up, it remains unclear if these methods are used in practice. This study explored ladder set-up behaviours in a field environment. Professional installers of a company in the cable and other pay TV industry were observed for ladder set-up at their worksites. The results showed that the actual angles of 265 ladder set-ups by 67 participants averaged 67.3° with a standard deviation of 3.22°. Although all the participants had training on recommended ladder set-up methods, only 3 out of 67 participants applied these methods in their daily work and even they failed to achieve the desired 75.5° angle. Therefore, ladder set-up remains problematic in real-world situations. Practitioner Summary: Professional installers of a cable company were observed for portable straight ladder set-up at their worksites. The ladder inclined angle averaged 67.3° with a standard deviation of 3.22°, while the recommended angle is 75.5°. Only a few participants used the methods that they learned during training in their daily work. PMID:26672809

  1. The influence of incident angle on physical properties of a novel back contact prepared by oblique angle deposition

    NASA Astrophysics Data System (ADS)

    Liu, Yang; Zhao, Yue; Feng, Yue; Shen, Jiesheng; Liang, Xiaoyan; Huang, Jian; Min, Jiahua; Wang, Linjun; Shi, Weimin

    2016-02-01

    In this paper, oblique vacuum thermal evaporation and direct current (DC) magnetron sputtering technique are used to produce a novel back contact electrode (BCE) of CuInS2 solar cell. These novel back contact electrodes (BCEs) are based on a layered structure of Mo/Ag/Mo (MAM). The influence of vapor source incidence angle θ on optical-electrical properties of novel BCE is investigated by X-ray Diffraction (XRD), Surface Profiler, Atomic Force Microscope (AFM), UV-vis-IR Spectrometer, and Four-point Probe Method. According to the analysis of AFM images of BCEs, the variation tendencies of surface roughness and uniformity are closely related to the incidence angle θ. The surface roughness increases with the increase of incidence angle θ, but the uniformity becomes poor at same time. This phenomenon can be attributed to the variation of interlayer Ag films (the density and inclined angle of Ag nanorods). The results of four-point probe test show that the novel BCE deposited by vapor source incidence angle θ equal to 45° owns the lowest resistance value of 3.71 × 10-8 Ω m, which is probably due to a loose and multi-point contact interface between Ag layer and top layer (Mo2). The reflectance of novel BCEs deposited by incident angle less than 45° is higher than that of normal bi-layer Mo (Mo12) BCE. As a result, the efficiency of corresponding solar cell may be upgraded.

  2. Straight ladder inclined angle in a field environment: the relationship among actual angle, method of set-up and knowledge.

    PubMed

    Chang, Wen-Ruey; Huang, Yueng-Hsiang; Chang, Chien-Chi; Brunette, Christopher; Fallentin, Nils

    2016-08-01

    Ladder inclined angle is a critical factor that could lead to a slip at the base of portable straight ladders, a major cause of falls from heights. Despite several methods established to help workers achieve the recommended 75.5° angle for ladder set-up, it remains unclear if these methods are used in practice. This study explored ladder set-up behaviours in a field environment. Professional installers of a company in the cable and other pay TV industry were observed for ladder set-up at their worksites. The results showed that the actual angles of 265 ladder set-ups by 67 participants averaged 67.3° with a standard deviation of 3.22°. Although all the participants had training on recommended ladder set-up methods, only 3 out of 67 participants applied these methods in their daily work and even they failed to achieve the desired 75.5° angle. Therefore, ladder set-up remains problematic in real-world situations. Practitioner Summary: Professional installers of a cable company were observed for portable straight ladder set-up at their worksites. The ladder inclined angle averaged 67.3° with a standard deviation of 3.22°, while the recommended angle is 75.5°. Only a few participants used the methods that they learned during training in their daily work.

  3. Ultrasonic anemometer angle of attack errors under turbulent conditions

    NASA Astrophysics Data System (ADS)

    Nakai, T.

    2009-12-01

    Measurements of eddy fluxes are premised on the assumption that wind speeds are measured accurately by an ultrasonic anemometer. Recently, ultrasonic anemometers have been shown to suffer errors depending on the angle of attack, which is the angle between the wind vector and the horizontal. The correction of these errors resulted in general increases in eddy fluxes. However, since the check of the angle of attack dependent error was carried out in the wind tunnel experiment, which would be under the condition of nearly laminar flow, the applicability of this correction to the field data under turbulent conditions has been questioned. In this study, angle of attack dependencies of wind speeds measured by Gill Windmaster ultrasonic anemometers were assessed by field experiment over meadow, considered to be turbulent conditions. By using five identical anemometers, two pairs of systems were prepared: two anemometers for references and one between them for tilt. The dependencies of (co)sine responses of anemometers on angles of attack of 0 to -90 degrees in 10-degree steps and 45 degrees were checked, and clarified that the angle of attack dependent errors occur also under turbulent conditions, with results similar to the wind tunnel experiments. Sine responses of vertical wind speeds depended not only on vertical angle of attack but also on horizontal wind direction, which had not been considered in previous studies. For more robust correction, alternative calibration functions were obtained empirically so as to reasonably explain our field experimental results. Applying this new correction, eddy fluxes increased substantially even over meadow, which is somewhat aerodynamically smooth compared with forests or agricultural fields.

  4. Reliability of the ATD Angle in Dermatoglyphic Analysis.

    PubMed

    Brunson, Emily K; Hohnan, Darryl J; Giovas, Christina M

    2015-09-01

    The "ATD" angle is a dermatoglyphic trait formed by drawing lines between the triradii below the first and last digits and the most proximal triradius on the hypothenar region of the palm. This trait has been widely used in dermatoglyphic studies, but several researchers have questioned its utility, specifically whether or not it can be measured reliably. The purpose of this research was to examine the measurement reliability of this trait. Finger and palm prints were taken using the carbon paper and tape method from the right and left hands of 100 individuals. Each "ATD" angle was read twice, at different times, by Reader A, using a goniometer and a magnifying glass, and three times by a Reader B, using Adobe Photoshop. Inter-class correlation coefficients were estimated for the intra- and inter-reader measurements of the "ATD" angles. Reader A was able to quantify ATD angles on 149 out of 200 prints (74.5%), and Reader B on 179 out of 200 prints (89.5%). Both readers agreed on whether an angle existed on a print 89.8% of the time for the right hand and 78.0% for the left. Intra-reader correlations were 0.97 or greater for both readers. Inter-reader correlations for "ATD" angles measured by both readers ranged from 0.92 to 0.96. These results suggest that the "ATD" angle can be measured reliably, and further imply that measurement using a software program may provide an advantage over other methods.

  5. Physiological response of wild rainbow trout to angling: Impact of angling duration, fish size, body condition, and temperature

    USGS Publications Warehouse

    Meka, J.M.; McCormick, S.D.

    2005-01-01

    This study evaluated the immediate physiological response of wild rainbow trout to catch-and-release angling in the Alagnak River, southwest Alaska. Information was recorded on individual rainbow trout (n = 415) captured by angling including landing time and the time required to remove hooks (angling duration), the time to anesthetize fish in clove oil and withdraw blood, fish length and weight, and water temperature at capture locations. Plasma cortisol, glucose, ions (sodium, potassium, chloride), and lactate were analyzed to determine the effects of angling duration, fish size, body condition, and temperature. Levels of plasma ions did not change significantly during the observed physiological response and levels of plasma glucose were sometimes influenced by length (2000, 2001), body condition (2001), or temperature (2001). Levels of plasma cortisol and lactate in extended capture fish (angling duration greater than 2 min) were significantly higher than levels in rapid capture fish (angling duration less than 2 min). Rapid capture fish were significantly smaller than extended capture fish, reflecting that fish size influenced landing and handling times. Fish size was related to cortisol and lactate in 2002, which corresponded to the year when larger fish were captured and there were longer landing times. Body condition (i.e., weight/length regression residuals index), was significantly related to lactate in 2000 and 2001. Water temperatures were higher in 2001 (mean temperature ± S.E., 13 ± 2oC) than in 2002 (10 ± 2oC), and fish captured in 2001 had significantly higher cortisol and lactate concentrations than fish captured in 2002. The pattern of increase in plasma cortisol and lactate was due to the amount of time fish were angled, and the upper limit of the response was due to water temperature. The results of this study indicate the importance of minimizing the duration of angling in order to reduce the sublethal physiological disturbances in wild

  6. Repulsion-based model for contact angle saturation in electrowetting

    PubMed Central

    2015-01-01

    We introduce a new model for contact angle saturation phenomenon in electrowetting on dielectric systems. This new model attributes contact angle saturation to repulsion between trapped charges on the cap and base surfaces of the droplet in the vicinity of the three-phase contact line, which prevents these surfaces from converging during contact angle reduction. This repulsion-based saturation is similar to repulsion between charges accumulated on the surfaces of conducting droplets which causes the well known Coulombic fission and Taylor cone formation phenomena. In our model, both the droplet and dielectric coating were treated as lossy dielectric media (i.e., having finite electrical conductivities and permittivities) contrary to the more common assumption of a perfectly conducting droplet and perfectly insulating dielectric. We used theoretical analysis and numerical simulations to find actual charge distribution on droplet surface, calculate repulsion energy, and minimize energy of the total system as a function of droplet contact angle. Resulting saturation curves were in good agreement with previously reported experimental results. We used this proposed model to predict effect of changing liquid properties, such as electrical conductivity, and system parameters, such as thickness of the dielectric layer, on the saturation angle, which also matched experimental results. PMID:25759748

  7. Pitch-angle scattering of cometary ions: Computer simulations

    SciTech Connect

    Gary, S.P.; Winske, D. ); Miller, R.H. )

    1991-06-01

    Pitch-angle evolution of newborn cometary ion is studied by means of one-dimensional electromagnetic hybrid computer simulations of homogeneous plasmas. Newborn ions are injected into the simulations at a constant rate, with a velocity relative to the solar wind which makes an angle {alpha} with respect to the ambient magnetic field. The simulations are done with relatively weak ion injection rates commensurate with those in the distant environment of comet Halley. In response to the linear temporal growth of the fluctuating magnetic field energy, the injected ions pitch-angle scatter toward isotropy in both the quasi-parallel (0{degree} {le} {alpha} {approx} {le} 60{degree}) and quasi-perpendicular(60{degree} < {alpha} {le} 90{degree}) regimes. For the injection of cometary oxygen ions the simulations show pitch angle scattering rates that are essentially independent of the solar wind ion/cometary ion relative speed, and increase as the square root of the injection rate. Furthermore, the oxygen ion pitch angle scattering rate at perpendicular injection is approximately twice that in the quasi-parallel regime, in qualitative agreement with observations at comet Halley.

  8. High Pressure Angle Gears: Comparison to Typical Gear Designs

    NASA Technical Reports Server (NTRS)

    Handschuh, Robert F.; Zabrajsek, Andrew J.

    2010-01-01

    A preliminary study has been completed to determine the feasibility of using high-pressure angle gears in aeronautic and space applications. Tests were conducted in the NASA Glenn Research Center (GRC) Spur Gear Test Facility at speeds up to 10,000 rpm and 73 N*m (648 in.*lb) for 3.18, 2.12, and 1.59 module gears (8, 12, and 16 diametral pitch gears), all designed to operate in the same test facility. The 3.18 module (8-diametral pitch), 28 tooth, 20deg pressure angle gears are the GRC baseline test specimen. Also, 2.12 module (12-diametral pitch), 42 tooth, 25deg pressure angle gears were tested. Finally 1.59 module (16-diametral pitch), 56 tooth, 35deg pressure angle gears were tested. The high-pressure angle gears were the most efficient when operated in the high-speed aerospace mode (10,000 rpm, lubricated with a synthetic turbine engine oil), and produced the lowest wear rates when tested with a perfluoroether-based grease. The grease tests were conducted at 150 rpm and 71 N*m (630 in.*lb).

  9. Constant-variable flip angles for hyperpolarized media MRI

    NASA Astrophysics Data System (ADS)

    Deng, He; Zhong, Jianping; Ruan, Weiwei; Chen, Xian; Sun, Xianping; Ye, Chaohui; Liu, Maili; Zhou, Xin

    2016-02-01

    The longitudinal magnetization of hyperpolarized media, such as hyperpolarized 129Xe, 3He, etc., is nonrenewable. When the MRI data acquisition begins at the k-domain center, a constant flip angle (CFA) results in an image of high signal-to-noise ratio (SNR) but sacrifices the accuracy of spatial information. On the other hand, a variable flip angle (VFA) strategy results in high accuracy but suffers from a low SNR. In this paper, we propose a novel scheme to optimize both the SNR and accuracy, called constant-variable flip angles (CVFA). The proposed scheme suggests that hyperpolarized magnetic resonance signals are firstly acquired through a train of n∗ CFA excitation pulses, followed by a train of N-n∗ VFA excitation pulses. We simulate and optimize the flip angle used in the CFA section, the number of CFA excitation pulses, the number of VFA excitation pulses, and the initial and final variable flip angles adopted in the VFA section. Phantom and in vivo experiments demonstrate the good performance of the CVFA designs and their ability to maintain both high SNR and spatial resolution.

  10. Controlling Compressor Vane Flow Vectoring Angles at Transonic Speeds

    NASA Astrophysics Data System (ADS)

    Munson, Matthew; Rempfer, Dietmar; Williams, David; Acharya, Mukund

    2003-11-01

    The ability to control flow separation angles from compressor inlet guide vanes with a Coanda-type actuator is demonstrated using both wind tunnel experiments and finite element simulations. Vectoring angles up to 40 degrees from the uncontrolled baseline state were measured with helium schlieren visualization at transonic Mach numbers ranging from 0.1 to 0.6, and with airfoil chord Reynolds numbers ranging from 89,000 to 710,000. The magnitude of the vectoring angle is shown to depend upon the geometry of the trailing edge, and actuator slot size, and the momentum flux coefficient. Under certain conditions the blowing has no effect on the vectoring angle indicating that the Coanda effect is not present. DNS simulations with the finite element method investigated the effects of geometry changes and external flow. Continuous control of the vectoring angle is demonstrated, which has important implications for application to rotating machinery. The technique is shown to reduce the stall flow coefficient by 15 percent in an axial flow compressor.

  11. Estimation of crank angle for cycling with a powered prosthesis.

    PubMed

    Lawson, B E; Shultz, A; Ledoux, E; Goldfarb, M

    2014-01-01

    In order for a prosthesis to restore power generation during cycling, it must supply torque in a manner that is coordinated with the motion of the bicycle crank. This paper outlines an algorithm for the real time estimation of the angular position of a bicycle crankshaft using only measurements internal to an intelligent knee and ankle prosthesis. The algorithm assumes that the rider/prosthesis/bicycle system can be modeled as a four-bar mechanism. Assuming that a prosthesis can generate two independent angular measurements of the mechanism (in this case the knee angle and the absolute orientation of the shank), Freudenstein's equation can be used to synthesize the mechanism continuously. A recursive least-squares algorithm is implemented to estimate the Freudenstein coefficients, and the resulting link lengths are used to reformulate the equation in terms of input-output relationships mapping both measured angles to the crank angle. Using two independent measurements allows the algorithm to uniquely determine the crank angle from multi-valued functions. In order to validate the algorithm, a bicycle was mounted on a trainer and configured with the prosthesis using an artificial hip joint attached to the seat post. Motion capture was used to monitor the mechanism for forward and backward pedaling and the results are compared to the output of the presented algorithm. Once the parameters have converged, the algorithm is shown to predict the crank angle within 15° of the externally measured value throughout the entire crank cycle during forward rotation.

  12. Discriminating electromagnetic radiation based on angle of incidence

    DOEpatents

    Hamam, Rafif E.; Bermel, Peter; Celanovic, Ivan; Soljacic, Marin; Yeng, Adrian Y. X.; Ghebrebrhan, Michael; Joannopoulos, John D.

    2015-06-16

    The present invention provides systems, articles, and methods for discriminating electromagnetic radiation based upon the angle of incidence of the electromagnetic radiation. In some cases, the materials and systems described herein can be capable of inhibiting reflection of electromagnetic radiation (e.g., the materials and systems can be capable of transmitting and/or absorbing electromagnetic radiation) within a given range of angles of incidence at a first incident surface, while substantially reflecting electromagnetic radiation outside the range of angles of incidence at a second incident surface (which can be the same as or different from the first incident surface). A photonic material comprising a plurality of periodically occurring separate domains can be used, in some cases, to selectively transmit and/or selectively absorb one portion of incoming electromagnetic radiation while reflecting another portion of incoming electromagnetic radiation, based upon the angle of incidence. In some embodiments, one domain of the photonic material can include an isotropic dielectric function, while another domain of the photonic material can include an anisotropic dielectric function. In some instances, one domain of the photonic material can include an isotropic magnetic permeability, while another domain of the photonic material can include an anisotropic magnetic permeability. In some embodiments, non-photonic materials (e.g., materials with relatively large scale features) can be used to selectively absorb incoming electromagnetic radiation based on angle of incidence.

  13. Automated measurement of diagnostic angles for hip dysplasia

    NASA Astrophysics Data System (ADS)

    de Raedt, Sepp; Mechlenburg, Inger; Stilling, Maiken; Rømer, Lone; Søballe, Kjeld; de Bruijne, Marleen

    2013-03-01

    A fully automatic method for measuring diagnostic angles of hip dysplasia is presented. The method consists of the automatic segmentation of CT images and detection of anatomical landmarks on the femur and acetabulum. The standard angles used in the diagnosis of hip dysplasia are subsequently automatically calculated. Previous work in automating the measuring of angles required the manual segmentation or delineation of the articular joint surface. In the current work automatic segmentation is established using graph-cuts with a cost function based on a sheetness score to detect the sheet-like structure of the bone. Anatomical landmarks are subsequently detected using heuristics based on ray-tracing and the distance to the approximated acetabulur joint surface. Standard diagnositic angles are finally calculated and presented for interpretation. Experiments using 26 patients, showed a good agreement with gold standard manual measurements by an expert radiologist as performed in daily practice. The mean difference for the five angles was between -1:1 and 2:0 degrees with a concordance correlation coefficient between 0:87 and 0:93. The standard deviation varied between 2:3 and 4:1 degrees. These values correspond to values found in evaluating interobserver and intraobserver variation for manual measurements. The method can be used in clinical practice to replace the current manual measurements performed by radiologists. In the future, the method will be integrated into an intraoperative surgical guidance system.

  14. The Influence of Dynamic Contact Angle on Wetting Dynamics

    NASA Technical Reports Server (NTRS)

    Rame, Enrique; Garoff, Steven

    2005-01-01

    When surface tension forces dominate, and regardless of whether the situation is static or dynamic, the contact angle (the angle the interface between two immiscible fluids makes when it contacts a solid) is the key parameter that determines the shape of a fluid-fluid interface. The static contact angle is easy to measure and implement in models predicting static capillary surface shapes and such associated quantities as pressure drops. By contrast, when the interface moves relative to the solid (as in dynamic wetting processes) the dynamic contact angle is not identified unambiguously because it depends on the geometry of the system Consequently, its determination becomes problematic and measurements in one geometry cannot be applied in another for prediction purposes. However, knowing how to measure and use the dynamic contact angle is crucial to determine such dynamics as a microsystem throughput reliably. In this talk we will present experimental and analytical efforts aimed at resolving modeling issues present in dynamic wetting. We will review experiments that show the inadequacy of the usual hydrodynamic model when a fluid-fluid meniscus moves over a solid surface such as the wall of a small tube or duct. We will then present analytical results that show how to parametrize these problems in a predictive manner. We will illustrate these ideas by showing how to implement the method in numerical fluid mechanical calculations.

  15. Analyzing angle crashes at unsignalized intersections using machine learning techniques.

    PubMed

    Abdel-Aty, Mohamed; Haleem, Kirolos

    2011-01-01

    A recently developed machine learning technique, multivariate adaptive regression splines (MARS), is introduced in this study to predict vehicles' angle crashes. MARS has a promising prediction power, and does not suffer from interpretation complexity. Negative Binomial (NB) and MARS models were fitted and compared using extensive data collected on unsignalized intersections in Florida. Two models were estimated for angle crash frequency at 3- and 4-legged unsignalized intersections. Treating crash frequency as a continuous response variable for fitting a MARS model was also examined by considering the natural logarithm of the crash frequency. Finally, combining MARS with another machine learning technique (random forest) was explored and discussed. The fitted NB angle crash models showed several significant factors that contribute to angle crash occurrence at unsignalized intersections such as, traffic volume on the major road, the upstream distance to the nearest signalized intersection, the distance between successive unsignalized intersections, median type on the major approach, percentage of trucks on the major approach, size of the intersection and the geographic location within the state. Based on the mean square prediction error (MSPE) assessment criterion, MARS outperformed the corresponding NB models. Also, using MARS for predicting continuous response variables yielded more favorable results than predicting discrete response variables. The generated MARS models showed the most promising results after screening the covariates using random forest. Based on the results of this study, MARS is recommended as an efficient technique for predicting crashes at unsignalized intersections (angle crashes in this study).

  16. Estimation of crank angle for cycling with a powered prosthesis.

    PubMed

    Lawson, B E; Shultz, A; Ledoux, E; Goldfarb, M

    2014-01-01

    In order for a prosthesis to restore power generation during cycling, it must supply torque in a manner that is coordinated with the motion of the bicycle crank. This paper outlines an algorithm for the real time estimation of the angular position of a bicycle crankshaft using only measurements internal to an intelligent knee and ankle prosthesis. The algorithm assumes that the rider/prosthesis/bicycle system can be modeled as a four-bar mechanism. Assuming that a prosthesis can generate two independent angular measurements of the mechanism (in this case the knee angle and the absolute orientation of the shank), Freudenstein's equation can be used to synthesize the mechanism continuously. A recursive least-squares algorithm is implemented to estimate the Freudenstein coefficients, and the resulting link lengths are used to reformulate the equation in terms of input-output relationships mapping both measured angles to the crank angle. Using two independent measurements allows the algorithm to uniquely determine the crank angle from multi-valued functions. In order to validate the algorithm, a bicycle was mounted on a trainer and configured with the prosthesis using an artificial hip joint attached to the seat post. Motion capture was used to monitor the mechanism for forward and backward pedaling and the results are compared to the output of the presented algorithm. Once the parameters have converged, the algorithm is shown to predict the crank angle within 15° of the externally measured value throughout the entire crank cycle during forward rotation. PMID:25571415

  17. 94. 22'X34' original blueprint, VariableAngle Launcher, 'MAIN RAIL' drawn at ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    94. 22'X34' original blueprint, Variable-Angle Launcher, 'MAIN RAIL' drawn at 1'=1'-0'. (BUORD Sketch # 207406). - Variable Angle Launcher Complex, Variable Angle Launcher, CA State Highway 39 at Morris Reservior, Azusa, Los Angeles County, CA

  18. Digital holographic metrology based on multi-angle interferometry.

    PubMed

    Dong, Jun; Jiang, Chao; Jia, Shuhai

    2016-09-15

    We propose a multi-angle interferometry method for digital holographic metrology. In an application of three-dimensional (3D) reconstruction, the hologram corresponding to a different illumination angle is recorded as the illumination angle with a single wavelength tilted at regular intervals by an electronically controlled rotating stage. A Fourier-transform-based axial depth scanning algorithm formed by the reconstructed phase is used to obtain the height point by point over the whole field of view. Hence, the 3D reconstruction can be obtained effectively; even the object has large depth discontinuities resulting from the difficulty of the phase unwrapping. Due to a monochrome source only being used, the method is available for objects with wavelength-dependent reflectivity and those that are free of chromatic aberration caused by the different wavelengths. PMID:27628382

  19. Angled rigid neuroendoscope for continuous intraoperative visual monitoring: technical note.

    PubMed

    Tamaki, N; Hara, Y; Takaishi, Y; Shimada, S

    2001-03-01

    We developed and tested a new, angled rigid endoscope as a tool for performing continuous visual monitoring during microsurgery. The shaft of the scope is angled 110 degrees at its midportion using a prism. We used the scope continuously in 30 cases including 15 pituitary tumours, 7 brain tumours, 7 cerebral aneurysms, and one hemifacial spasm. For pituitary tumours the tip of the scope was positioned in the sphenoid sinus or in the cavity formed by tumour removal; for cerebral aneurysms it was placed behind the parent artery or the aneurysmal neck. Image quality was acceptable for intraoperative monitoring. In no case did the neuroendoscope have a deleterious impact on th e proper function of the microscope or surgical instruments. This angled rigid scope was more effective for intraoperative monitoring than conventional straight scopes. PMID:11243766

  20. Control of the bias tilt angles in nematic liquid crystals

    NASA Astrophysics Data System (ADS)

    Yablonskii, S. V.; Nakayama, K.; Okazaki, S.; Ozaki, M.; Yoshino, K.; Palto, S. P.; Baranovich, M. Yu.; Michailov, A. S.

    1999-03-01

    The pretilt angle controlled by electric field was studied by the modulation ellipsometry technique. The easy direction of compensated nematic liquid crystals was controlled by surface flexoelectric torque created by the linear coupling of the director deformation and electric field. The weak anchoring energy necessary for the occurrence of flexoelectric distortion was produced by unidirectional rubbing of the clean indium-tin-oxide covered glasses with a cotton cloth. The pretilt angle was measured as a function of electric field. Long relaxation times of the optical response (hundreds of seconds) were observed. The rubbed thin polyvinyl alcohol and polyimide aligning layers were seen to promote strong anchoring energy (>0.5 erg/cm2) preventing any deviation of pretilt angle and, consequently, to suppress the optical response. The probable applications of the obtained results are discussed.