WorldWideScience

Sample records for cerebellopontine angle secondary

  1. Cerebellopontine angle Hodgkin's disease

    International Nuclear Information System (INIS)

    Intracranial Hodgkin's disease is a rare site of involvement, and even more rare is its presentation as a cerebellopontine angle mass. It can be difficult to diagnose especially when recurrent tumors occur because both CT and lumbar puncture have been shown to have a relatively low yield. Gadolinium-enhanced MRI is more sensitive. It is concluded that while the imaging findings can be non-specific, the rapid response to therapy (steroids) may provide a clue to diagnosis. Copyright (1999) Blackwell Science Pty Ltd

  2. Pneumocephalus in cerebellopontine angle and meningitis secondary to chronic otitis media in a child

    Directory of Open Access Journals (Sweden)

    Shailendra Ratre

    2015-01-01

    Full Text Available Pneumocephalus is a rare complication of chronic otitis media. Despite its rarity intra-cranial air carries a potential risk of increased intra-cranial pressure or meningitis, which requires immediate therapy. A 10-year-old child presented to us with complaints of fever, headache, vomiting, and decreased hearing from left ear. He had history of left ear discharge since 2 years. Clinical examination revealed neck rigidity and left chronic otitis media. Contrast enhanced computed axial tomography scan of head [Figure 1] and [Figure 2] showed pneumocephalus in left cerebellopontine angle, opacification of left middle ear and nonpneumatisation of left mastoid. Child was immediately put on empirical intravenous antibiotics and decongestants. He showed clinical improvement in 3 days. Pneumocephalus secondary to chronic otitis media is extremely rare; we are reporting one such case in a child with review of literature.

  3. Disorders of the cerebellopontine angle

    International Nuclear Information System (INIS)

    Disorders of the cerebellopontine angle may present by symptoms like vertigo, hearing problems, affection of the trigeminal or facial nerve. Ipsilateral ataxia and contralateral hemiparesis develop in case of a rather large tumor in this region and display an involvement of the cerebellum and/or brainstem. However, some of these typical symptoms are not recognized by the patient. Thus, in case of a suspicion of a disorder of the cerebellopontine angle the relevant functions have to be tested clinically. In addition, electrophysiology can confirm dysfunction of these cranial nerves. Mainstay of the therapy should be the treatment of the underlying cause. Nevertheless, not seldom it is necessary to treat symptoms like vertigo or facial pain. (orig.)

  4. Arteriovenous malformation in the cerebellopontine angle presenting as trigeminal neuralgia

    Directory of Open Access Journals (Sweden)

    Paulo C. Figueiredo

    1989-03-01

    Full Text Available A case of arteriovenous malformation of the left cerebellopontine angle causing symptoms of ipsilateral trigeminal neuralgia is reported. Pain relief followed microsurgical removal of the malformation. The authors review the literature on the subject.

  5. Cerebellar glioblastoma multiforme presenting as a cerebellopontine angle mass

    Directory of Open Access Journals (Sweden)

    Anupam Jindal

    2006-01-01

    Full Text Available Cerebellar glioblastoma multiforme (GBM is a highly malignant brain tumour, which is exceedingly rare and such tumour presenting as cerebellopontine angle (CPA mass is even rarer. We here discuss the case of a 15-year-old girl who had cerebellar GBM presenting as CPA mass that resembled meningioma on CT scan and was managed successfully with minimal problems.

  6. A case of right cerebellopontine-angle lesion: psychotic symptoms and magnetic resonance imaging findings.

    Science.gov (United States)

    Jung, Min Soo; Lee, Byung Dae; Park, Je Min; Lee, Young Min; Moon, Eun Soo

    2012-09-01

    Here, we report psychotic symptoms together with a right cerebellopontine-angle lesion. A37-year-old female patient presented with a trigeminal Schwannoma occupying the right cerebellopontine angle. Her psychotic symptoms included auditory hallucinations and delusions of persecution. T1- and T2-weighted images on magnetic resonance imaging (MRI) revealed hyperintense and hypointense areas in the right cerebellopontine angle, respectively. The clinical and neuroimaging reviews in this case suggest that sudden onset of psychotic symptoms at a mature age may be associated with a right cerebellopontine-angle lesion and that MRI should be used to evaluate possible organic bases in patients that present with psychosis. PMID:22993532

  7. Malignant melanoma of the cerebello-pontine angle region

    Directory of Open Access Journals (Sweden)

    F. Menezes Braga

    1989-12-01

    Full Text Available A case of malignant melanoma in the cerebello-pontine angle region is presented in a 72 years old female patient, who had neurological examination and CT scan suggestive of acoustic neuroma. The surgical finding and the histological examination provided the diagnosis. As a primary focus was not found on clinical examination and although autopsy was not carried out, there is a possibility of the diagnosis being a primary malignant melanoma in CNS. This specific location for this kind of tumor was found to be rare when literature is looked up.

  8. Disorders of the cerebellopontine angle; Klinik der Kleinhirnbrueckenwinkelerkrankungen

    Energy Technology Data Exchange (ETDEWEB)

    Block, F. [Helios-Kliniken Schwerin (Germany). Neurologische Klinik

    2006-03-15

    Disorders of the cerebellopontine angle may present by symptoms like vertigo, hearing problems, affection of the trigeminal or facial nerve. Ipsilateral ataxia and contralateral hemiparesis develop in case of a rather large tumor in this region and display an involvement of the cerebellum and/or brainstem. However, some of these typical symptoms are not recognized by the patient. Thus, in case of a suspicion of a disorder of the cerebellopontine angle the relevant functions have to be tested clinically. In addition, electrophysiology can confirm dysfunction of these cranial nerves. Mainstay of the therapy should be the treatment of the underlying cause. Nevertheless, not seldom it is necessary to treat symptoms like vertigo or facial pain. (orig.) [German] Schwindel, Hoerstoerungen, Affektionen des N. trigeminus oder des N. facialis stellen die wesentlichen und haeufigen Symptome bei Kleinhirnbrueckenwinkelerkrankungen dar. Ipsilaterale Gliedmassenataxie und kontralaterale Hemiparese sprechen fuer eine Mitbeteiligung von Kleinhirn und/oder Hirnstamm, die meist nur bei grossen Prozessen in dieser Region auftreten. Da einige Veraenderungen sich fuer den Patienten unbemerkt entwickeln, ist bei Verdacht eine gezielte klinische Untersuchung dieser Funktionen angezeigt, die durch elektrophysiologische Diagnostik wie z. B. akustisch evozierte Potenziale oder Blinkreflexe untermauert werden kann. Auch wenn natuerlich die kausale Therapie im Vordergrund steht, ist es gar nicht selten notwendig, eine symptomatische Behandlung durchzufuehren. Dies trifft besonders fuer Symptome wie Schwindel oder Gesichtsschmerzen zu. (orig.)

  9. Cerebellopontine angle lipomas: magnetic resonance imaging findings in two cases

    Energy Technology Data Exchange (ETDEWEB)

    Borges, Rafael S. [Clinica de Diagnostico por Imagem Multi-Imagem, Rio de Janeiro, RJ (Brazil); Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Dept. de Radiologia; Brito, Cecilia Castelo Branco [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Fac. de Medicina; Carvalho, Gustavo A. [Clinica Bambina, Rio de Janeiro, RJ (Brazil). Dept. de Neurocirurgia; Hospital Silvestre, Rio de Janeiro, RJ (Brazil); Domingues, Romeu C. [Clinicas CDPI e Multi-Imagem, Rio de Janeiro RJ (Brazil); Gasparetto, Emerson L. [Clinicas CDPI e Multi-Imagem, Rio de Janeiro RJ (Brazil)

    2009-07-01

    Vestibular schwannomas and meningiomas are the most common lesions of the cerebellopontine angle (CPA), accounting for approximately 85-90% of the tumors seen in this location. Lipomas are rare at this topography, representing about 0.15% of the CPA lesions. These tumors are mal developmental masses that arise from abnormal differentiation of the meninx primitive. Clinically, CPA lipomas can cause slowly progressive neurological symptoms and signs affecting cranial nerves or brain stem. Because these lesions usually are strongly attached to the surrounding structures, any surgical attempts of complete resection can result in neural or vascular damage, reinforcing the importance of the pre-operative imaging diagnosis. Although the CT findings of CPA lipomas can be typical, the magnetic resonance (MR) imaging, especially the fat suppression sequences, had improved the identification of these lesions. We aimed to report two patients with a CPA lipoma, emphasizing the MR imaging findings. (author)

  10. Vascular anomalies of the cerebellopontine angle; Vaskulaere Erkrankungen des Kleinhirnbrueckenwinkels

    Energy Technology Data Exchange (ETDEWEB)

    Papanagiotou, P.; Grunwald, I.Q.; Politi, M.; Struffert, T.; Ahlhelm, F.; Reith, W. [Universitaetsklinikum des Saarlandes, Homburg/Saar (Germany). Klinik fuer Diagnostische und Interventionelle Neuroradiologie

    2006-03-15

    Vascular anomalies of the cerebellopontine angle are rare compared to tumors in this area. Irritation of the trigeminal, facial, or vestibulocochlear nerve may cause trigeminal neuralgia, hemifacial spasm and vertigo, or tinnitus accordingly. Vessel loops in the cerebellopontine cisterns may cause compression at the root entry or exit zone of the cranial nerves V, VII, and VIII, a phenomenon which is called ''vascular loop syndrome.'' Megadolichobasilar artery and aneurysms of the vertebrobasilar system can also lead to dislocation and compression of the cranial nerves and brain stem. Three-dimensional CISS MR imaging and MR angiography are useful in the detection of neurovascular compression. Microvascular decompression is an effective surgical procedure in the management of compression syndromes of the cranial nerves V, VII, and VIII. (orig.) [German] Gegenueber den Raumforderungen stellen vaskulaere Veraenderungen des Kleinhirnbrueckenwinkels eher eine Ausnahme dar. Trigeminusneuralgie, hemifazialer Spasmus und Schwindel oder Tinnitus koennen bei Irritationen des Nervus trigeminus, facialis und vestibulocochlearis auftreten. Schlingenbildungen der Gefaesse in den Kleinhirnzisternen koennen eine Kompression der Eintritts- oder Austrittszonen der Hirnnerven V, VII und VIII am Hirnstamm hervorrufen, was als ''Vascular-loop-Syndrom'' bezeichnet wird. Zu Verlagerungen und Kompressionen von Hirnnerven und Hirnstamm koennen, wenn auch seltener, die Megadolichobasilaris und Aneurysmen des vertebrobasilaeren Systems fuehren. Bezueglich der Bildgebung ist die Magnetresonanztomographie (MRT) die Methode der Wahl. Die 3D-CISS-Sequenz und die MR-Angiographie sind hilfreich zur Darstellung der neurovaskulaeren Kompression. Die Methode der mikrovaskulaeren Dekompression ist eine wirkungsvolle Methode zur Beseitigung gefaessbedingter Kompressionen der Hirnnerven V, VII und VIII. (orig.)

  11. Contrast-enhanced CISS imaging of cerebellopontine angle tumors

    Energy Technology Data Exchange (ETDEWEB)

    Tozaki, Mitsuhiro; Toyoda, Keiko; Hata, Yuichi; Fukuda, Yasushi; Fukuda, Kunihiko [Jikei Univ., Tokyo (Japan). School of Medicine; Katano, Shuichi

    1999-10-01

    Our purpose of this study was to evaluate the clinical usefulness of contrast-enhanced CISS-3DFT MR imaging for the diagnosis of CP angle tumors. CISS-3DFT MR imaging is expected for screening procedure of acoustic schwannoma because of excellent spatial resolution. Recently, we discovered contrast enhancement effect on CISS sequence in spite of heavily T{sub 2}-weighted images. Fourteen patients with CP angle tumors were performed on a 1.0 T MR unit. Transaxial CISS-3DFT MRI was obtained both before and after intravenous injections of Gd-DTPA. Multiplanar reconstructions (MPRs) were performed in all cases. Contrast enhancement effect of CP angle tumors, and the relationship between tumors and the adjacent cranial nerves were evaluated. Contrast enhancement effect of the tumors was present in all cases in spite of heavily T{sub 2}-weighted images of CISS sequences. In the internal auditory canal, relationship between the tumors and the cranial nerves was demonstrated in 6 cases (6/9). In the cerebellopontine cistern, all cases were demonstrated (11/11). Contrast-enhanced CISS-3DFT MR imaging with a good contrast resolution and an excellent spatial resolution is useful for the diagnosis of CP angle tumors. (author)

  12. Intraoperative Transcranial Motor-Evoked Potential Monitoring of the Facial Nerve during Cerebellopontine Angle Tumor Resection

    OpenAIRE

    Cosetti, Maura K.; Xu, Ming; Rivera, Andrew; Jethanamest, Daniel; Kuhn, Maggie A.; Beric, Aleksandar; Golfinos, John G.; Roland, J. Thomas

    2012-01-01

    Objective To determine whether transcranial motor-evoked potential (TCMEP) monitoring of the facial nerve (FN) during cerebellopontine angle (CPA) tumor resection can predict both immediate and long-term postoperative FN function.

  13. Traumatic Acute Subdural Hematoma Extending from the Posterior Cranial Fossa to the Cerebellopontine Angle

    OpenAIRE

    Gulsen, Salih; Sonmez, Erkin; Yilmaz, Cem; Altinors, Nur

    2009-01-01

    Posterior cranial fossa subdural hematomas and extension of the subdural hematoma to the cerebellopontine angle is rarely seen and the concurrent development of acute peripheral facial palsy and the management strategy have not previously been reported in this pathology because of its rarity. We present this case to emphasize that minor head trauma may lead to a posterior cranial fossa hematoma extending to the cerebellopontine angle and cause peripheral facial palsy in patients using aspirin...

  14. Surgical Outcomes of Cerebellopontine angle Tumors in 50 Cases

    Directory of Open Access Journals (Sweden)

    faramarz memari

    2015-01-01

    Full Text Available Introduction: To report our experience with a large series of surgical procedures for removal of cerebellopontine angle (CPA tumors using different approaches.   Materials and Methods: This was a retrospective analysis of 50 patients (mean age, 49 years with CPA tumors (predominantly acoustic neuroma who underwent surgical removal using appropriate techniques (principally a translabyrinthine approach during a 4-year period.   Results: One death occurred during this study. There were nine cases (18% of cerebrospinal fluid leak, and five patients (10% were diagnosed as having bacterial meningitis. Complete gross tumor removal was not achieved in four patients (8%. Facial nerve function as measured by the House Brackmann system was recorded in all patients 1 year following surgery: 32% had a score of 1 or 2; 26% had a score of 3 or 4; and 8% had a score of 5 or 6. Other complications included four cases of wound infection.   Conclusion:  The translabyrinthine approach was predominantly used in our series of CPA tumors, and complication rates were comparable with other large case series.

  15. MRI of the cerebellopontine angle in patients with cleido-cranial dysostosis

    International Nuclear Information System (INIS)

    Purpose: Cleidocranial dysostosis (CCD) is an autosomal dominant bone disorder in which deafness is common secondary to malformation of the middle ear structures. The study aimed at MRI evaluation of the cerebellopontine angle in 7 patients with a history of CCD - two generation spanned relatives. Material and methods: Cranial MRI in 7 patients with CCD (4 women/3 men aged between 8 and 46 years) was performed. In two patients hearing disorders were present. The examinations encompassed multi-planar spinecho sequences of the cerebellopontine angle in 3-mm slice thickness before and after administration of contrast medium. Results: The clinically most conspicuous female patient (hearing loss, ataxia, headache) showed a strongly contrast-enhancing tumor in MRI that was histologically proved to be an acoustic schwannoma. Concerning the other family members, no pathological findings were noted except for non-pneumatized mastoids. Conclusion: The first report of a patient with CCD and an acoustic schwannoma shows that in case of hearing loss in these patients also a retrocochlear cause must be considered. (orig.)

  16. Cerebellopontine angle epidermoid showing a positive enhancement upon metrizamide CT cisternography

    Energy Technology Data Exchange (ETDEWEB)

    Hasegawa, Takeshi; Wakamatsu, Koichi; Fujii, Toshiharu; Ito, Haruhide; Yamamoto, Shinjiro; Nagata, Izumi

    1985-04-01

    A case of epidermoid tumor in the left cerebellopontine angle cistern is reported in a 43-year-old woman with left trigeminal neuralgia. Plain CT scan revealed a low density area at the left cerebellopontine angle and left ambient cisterns, which could not be differentiated from their enlargement. Metrizamide CT cisternography showed an irregular, high density pattern in the low density filling defect which was extending into the suprasellar and interpeduncular cisterns. The developmental mechanism of this specific finding in the metrizamide CT cisternography was discussed on the basis of morphological characteristics of epidermoid tumor.

  17. Nonvestibular schwannoma tumors in the cerebellopontine angle: A structured approach and management guidelines

    DEFF Research Database (Denmark)

    Springborg, J.B.; Poulsgaard, L.; Thomsen, Jens Christian

    2008-01-01

    The most common cerebellopontine angle (CPA) tumor is a vestibular schwannoma, but one in five CPA tumors are not vestibular schwannomas. These tumors may require different management strategies. Compared with vestibular schwannomas, symptoms and signs from cranial nerve VIII are less frequent...

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

    Science.gov (United States)

    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

  19. Neuronavigation assisted decompression of trigeminal neuralgia caused by cerebellopontine angle osteoma

    OpenAIRE

    Iimura Yasushi; Saitou Rikizou; Abe Kazuhiro; Tsunoda Akira; Maruki Chikashi; Arai Hajime

    2014-01-01

    Trigeminal neuralgia (TN) is usually caused by vascular compression of the trigeminal nerve root entry zone, but can be caused by other factors such as tumors, vascular disorders, and demyelination in multiple sclerosis. We present a rare case with a huge osteoma located on the cerebellopontine angle (CPA) and causing TN. A 48-year-old woman presented with TN caused by a huge left CPA bone tumor. Surgery was performed by the lateral suboccipital approach under neuronavigation system guidance ...

  20. Facial nerve neurinoma presenting as middle cranial fossa and cerebellopontine angle mass : a case report.

    Directory of Open Access Journals (Sweden)

    Devi B

    2000-10-01

    Full Text Available Facial nerve neurinomas are rare. The tumours arising from the geniculate ganglion may grow anteriorly and superiorly and present as a mass in the middle cranial fossa. Only a few cases of facial nerve neurinomas presenting as middle cranial fossa mass have so far been reported. These tumours present with either long standing or intermittent facial palsy along with cerebellopontine angle syndrome.

  1. Imaging diagnosis of various small lesions in the cerebellopontine angle by Suboccipital air CT cisternography

    Energy Technology Data Exchange (ETDEWEB)

    Tsukahara, Kaoru (Toho Univ., Tokyo (Japan). School of Medicine)

    1989-11-01

    A modified air CT cisternography technique, characterized by suboccipital air infusion was carried out in a total of 180 patients over the past 5 years. The patients were divided into two groups according to their suspected lesions. The first group consisted of 151 patients who were diagnosed as having retrolabyrinthine lesions by neurootological examinations; 29 patients with facial twitching or trigeminal neuralgia were classified in the second group. In the first group, air CT cisternography revealed 21 cases of small acoustic tumors including intracanalicular tumors. Additionally, several unexpected small lesions were detected in the cerebellopontine angle. These included small meningiomas, osteoma, osteogenic tumor, nodulated acoustic nerve in neurofibromatosis, primary acoustic nerve atrophy, adhesive arachnoiditis, elongated basilar artery and patulous acoustic meatus. In the second group, the causative artery of neurovascular compression at the nerve exit zone failed to be confirmed in many cases, but satisfactory preoperative information concerning nerves and vessels in the cerebellopontine angle were provided by air CT cisternography. The advantages and disadvantages of air CT cisternography and MRI-CT for the diagnosis of small lesions in the cerebellopontine angle are also discussed. (author).

  2. Epidermoid cyst causing hemifacial spasm epidermoid cyst in cerebellopontine angle presenting with hemifacial spasm

    Directory of Open Access Journals (Sweden)

    Murat Alemdar

    2012-01-01

    Full Text Available Hemifacial Spasm (HS occurs idiopathically or secondary to the lesions compressing the root exit zone of the facial nerve symptomatically. Symptomatic HS is generally due to vascular compression. We report on a 23-year-old male with right sided HS for a month. Magnetic resonance imaging (MRI of the brain revealed a well-demarcated epidermoid cyst in the right cerebellopontine cistern. It was hypointense on T1-weighted imaging, hyperintense on T2-weighted imaging without contrast enhancement, hyperintense on DWI, and slightly hypointense on ADC relative to the brain. Although it caused shifting of the pons and medulla to the left side and compression of the right cerebellar peduncles and fourth ventricle, the sole symptom of the patient was HS. Clinicians are advised to request MRI/scan for brainstem lesions from the patients with HS. Epidermoid cysts in cerebellopontine cistern may present with HS as the sole symptom.

  3. Choroid plexus papilloma of cerebellopontine angle with extension to foramen magnum.

    Directory of Open Access Journals (Sweden)

    Kumar R

    1999-01-01

    Full Text Available A case of choroid plexus papilloma resembling meningioma of cerebellopontine (CP angle with its extension to foramen magnum is presented. Occurrence of this tumour in CP angle is very rare. Its extension towards foramen magnum is further rare. It was a real diagnostic enigma preoperatively as the tumour was resembling meningioma upto some extent on radiological study. Retromastoid craniectomy with microsurgical excision of tumour and its extension was achieved in toto. Tumour was attached to few rootlets of lower cranial nerves which were preserved. Attachment of the tumour with lower cranial nerves again caused diagnostic confusion with neurofibroma intraoperatively.

  4. CT and MR imaging of acquired abnormalities of the inner ear and cerebellopontine angle

    International Nuclear Information System (INIS)

    Introduction: Several entities of acquired lesions may affect the inner ear and cerebellopontine angle. The imaging of these lesions depends on the clinical history, and should be adapted to the lesion searched for and suspected by the otolaryngologist. In this paper, the modality of CT and MR imaging which is suited to delineate the acquired lesions of this region will be presented. Materials and methods: CT and/or MR imaging of the inner ear and cerebellopontine angle was performed in all cases in which an acquired lesion of this region was suspected by the otolaryngologist. CT was performed in the axial and coronal plane with the use of a high-resolution bone-window-level-setting. MRI was performed in the axial plane using high-resolution 3D T2-weighted fast spin echo sequences and 3D T1-weighted gradient echo sequences before and after the i.v. application of gadopentate dimeglumine. The obtained images were evaluated for the depiction of the acquired lesions. Results: CT best depicted osseous lesions such as traumatic affections or lesions leading to ossification of the inner ear. Tumorous lesions were delineated in those cases in which they yielded to bony changes. Inflammatory or tumorous lesions not yielding to bony changes or intralabyrintine calicifications were not depicted. MRI delineated very well all lesions leading to soft tissue changes, and moderately depicted traumatic changes yielding to less severe fractures affecting the investigated region. Conclusion: CT and MR imaging are suited differently to delineate the acquired lesions of the inner ear and cerebellopontine angle. CT is excellently suited to depict osseous lesions, while MRI is excellently suited to delineate lesions affecting the soft tissue structures. These two imaging modalities should be used depending on the clinical question, and are supposed to be complementary methods

  5. A comparative anatomical CT study of the vascular and nervous structures of the cerebello-pontine angle

    International Nuclear Information System (INIS)

    The arteries and veins of the cerebellopontine angle have been injected with a contrast medium permitting a precise anatomical reconnaissance of their topography and relations. These specimens have been explored by CT in order to define the opacified vessels and to differentiate them from the adjacent nervous tissue. Thus in CT it is possible to locate the cerebellar arteries, the petrous and medullo-pontine veins and the nerves of the cerebello-pontine angle. This study describes the normal appearance of the flocculus on CT and the criteria to distinguish the flocculus from the arteries and veins. Moreover it should contribute to the definition of the criteria of reliability of a CT diagnosis and its limits in the cerebello-pontine angle. (orig.)

  6. Solitary fibrous tumor of the cerebellopontine angle: A case report and literature review

    Directory of Open Access Journals (Sweden)

    Joe M Das

    2014-01-01

    Full Text Available Solitary fibrous tumors (SFT are rare dura-based mesenchymal tumors of the central nervous system. SFT occurring in the cerebellopontine (CP angle is very rare and only 21 cases have been reported in the literature until date. We present a 40-year-old male patient who presented with features of the right-sided facial and acoustic nerves paresis along with same sided cerebellar symptoms of 2 months duration. Magnetic resonance imaging revealed a T2 heterogeneously hyperintense extra-axial lesion, showing intense contrast enhancement in the right CP angle with solid and cystic areas. The lesion was not extending into the internal auditory canal. Digital subtraction angiography showed arterial feeders from vertebro-basilar system. The highly vascular lesion was excised near-totally by suboccipital retrosigmoid craniectomy. The lesion was diagnosed as SFT on histopathological examination and was positive for CD34 and bcl-2.

  7. Computed tomography and magnetic resonance imaging of acquired abnormalities of the inner ear and cerebello-pontine angle

    International Nuclear Information System (INIS)

    CT and MRI of acquired abnormalities of the inner ear and cerebello-pontine angle present themselves with very typical findings. The imaging should be adapted to the pathology looked for and either CT or MRI should be used alone or in combination.CT, especially high resolution CT (HRCT), provides an excellent bone contrast, while MRI has a much superior soft tissue contrast. Acute inflammatory changes of the inner ear are solely depicted by contrast-enhanced MRI. HRCT excellently depicts osseous changes of the inner ear and cerebellopontine angle such as chronic ossifying labyrinthitis occurring after acute labyrinthitis, otosclerotic or traumatic changes. Tumorous changes not yielding to bony changes are best delineated by MRI. Posttraumatic hemorrhage and chronic fibrotic changes within the labyrinth are depicted by MRI, only. In conclusion HRCT and MRI are excellent methods to delineate acquired abnormalities of the inner ear and cerebello-pontine angle. HRCT best depicts osseous changes while MRI best depicts soft tissue changes. HRCT and MRI are not concurrent methods but should better be used as complementary methods for imaging acquired abnormalities of inner ear and cerebellopontine angle. (orig.)

  8. Lipoma do ângulo pontocerebelar: relato de caso Lipoma of the cerebellopontine angle: case report

    Directory of Open Access Journals (Sweden)

    WALTER JOSÉ FAGUNDES-PEREYRA

    2000-09-01

    Full Text Available Os lipomas do ângulo pontocerebelar são tumores muito raros. Em geral são assintomáticos, achados fortuitos em autópsia, tomografia computadorizada (TC de crânio ou ressonância nuclear magnética do encéfalo. Os autores apresentam o caso de paciente, feminina, branca, 14 anos, há três anos com diminuição da audição à esquerda e há um ano com cefaléia, tipo hemicrânia à esquerda. A TC de crânio evidenciou lesão hipodensa, sem captação de contraste, no ângulo pontocerebelar esquerdo. A paciente foi submetida a cirurgia por via retrossigmóidea para abordagem da lesão, que se apresentou de coloração amarelada, característica de tecido adiposo. Tendo em vista o envolvimento de estruturas nervosas (VII e VIII nervos cranianos, optou-se pela exérese parcial da lesão. A paciente evoluiu com melhora da cefaléia, sem piora do déficit auditivo. Após três anos de seguimento, mantém o quadro estável. Conclui-se que os lipomas do ângulo pontocerebelar, quando assintomáticos, podem ser tratados conservadoramente. Entretanto aqueles associados a sintomatologia persistente e progressiva devem ser operados. A exérese total ou parcial vai depender do envolvimento ou não das estruturas neurovasculares adjacentes.Lipoma of the cerebellopontine angle is a very rare tumor. We report the case of a 14-years-old female, with left side deafness during three years, associated with headache. CT scan showed an hypodense mass, without enhancement at the cerebellopontine angle. The patient was treated surgically by left retrosigmoid approach. The lesion involved the eighth and seventh cranial nerves and only a partial removal was performed. The postoperative course was uneventful. She had no more headache; the deafness of the left side remained unchanged. Asymptomatic lipoma of the cerebellopontine angle can be treated conservatively, although those with progressive symptoms should be treated surgically, with total or partial remove

  9. An uncommon case of lymphoplasmacytic lymphoma in cerebellopontine angle region: Case report with a literature review.

    Science.gov (United States)

    Yan, Chengrui; Kong, Xiangyi; Yang, Lanshu; Ma, Wenbin

    2016-08-01

    In the central nervous system, cerebellopontine angle (CPA) lymphomas are rare; few cases have been reported. Lymphoplasmacytic lymphoma (LPL) in the CPA is rarer still, and often misdiagnosed as acoustic neuroma.We report a rare case of CPA LPL-a challenging diagnosis guided by clinical presentations, radiological signs, and postoperative pathological test.A 43-year-old woman presented with headaches. Her magnetic resonance imaging revealed an abnormal homogeneously enhancing mass in the left CPA. We present detailed analysis of her disease and review relevant literature.When surgically treated, her specimen showed a typical LPL histopathology pattern. After surgery, the patient's symptoms improved greatly, and she received chemotherapy.Despite its rarity, LPL should be considered in differential diagnoses of CPA lesions that mimic acoustic neuromas. PMID:27559959

  10. Neuronavigation assisted decompression of trigeminal neuralgia caused by cerebellopontine angle osteoma

    Directory of Open Access Journals (Sweden)

    Iimura Yasushi

    2014-09-01

    Full Text Available Trigeminal neuralgia (TN is usually caused by vascular compression of the trigeminal nerve root entry zone, but can be caused by other factors such as tumors, vascular disorders, and demyelination in multiple sclerosis. We present a rare case with a huge osteoma located on the cerebellopontine angle (CPA and causing TN. A 48-year-old woman presented with TN caused by a huge left CPA bone tumor. Surgery was performed by the lateral suboccipital approach under neuronavigation system guidance and regional decompression of the trigeminal nerve root entry zone was achieved. Intraoperative, neuro-navigation system was very useful for identification of the trigeminal nerve entry zone because normal anatomy had been obscured by the huge osteoma. Her pain disappeared completely immediately after surgery. The histological diagnosis was osteoma. TN is an expectative symptom of CPA tumors. Osteomas should be considered in patients with CPA tumors.

  11. Diagnosis and treatment of ependymoma of the cerebellopontine angle: a report of four cases

    International Nuclear Information System (INIS)

    Objective: To investigate the clinical feature and management of ependymoma of the cerebellopontine angle (CPA). Methods: Between 2002 and 2012, 4 patients with ependymoma of the CPA were treated in the General Hospital of Nanjing Military Command. The clinical data, image manifestations, operation and histopathological features were retrospectively analyzed with reference to domestic and foreign literature. Results: The clinical manifestations of 4 patients were similar to those of other CPA tumors, but imaging and pathology showed otherwise. The ependymoma was totally resected under a surgical microscope in 3 cases, and was subtotally resected in the other one. All were followed up 12-60 months and benefited from good therapeutic effect. Conclusion: Ependymoma of the CPA is rare, correct diagnosis and treatment of which requires rich clinical experience. (authors)

  12. Posterior internal auditory canal closure following the retrosigmoid approach to the cerebellopontine angle.

    Science.gov (United States)

    Leonetti, J P; Anderson, D E; Newell, D J; Smith, P G

    1993-01-01

    The retrosigmoid approach is utilized in a variety of cerebellopontine angle and internal auditory canal procedures. Drill curettage of the posterior internal auditory canal enhances lateral exposure, however, this step may also increase the patient's risk for postoperative cerebrospinal fluid (CSF) otorrhea. Obliteration of perilabyrinthine air cells is technically difficult and muscle graft displacement frequently occurs. A technique for posterior petrous dural flap stabilization of a temporalis muscle plug has proved successful in decreasing the risk of postoperative CSF fistula following retrosigmoid surgery. Temporal bone air-cell anatomy, as it relates to retrosigmoid, posterior internal auditory canal surgery is reviewed. Our technique for internal auditory canal closure, with bone wax, bone paté, muscle grafts, and petrous ridge dural flaps is outlined. PMID:8424473

  13. Evaluation of MR cisternography of the cerebellopontine angle using a balanced fast-field-echo sequence: preliminary findings

    Energy Technology Data Exchange (ETDEWEB)

    Tsuchiya, Kazuhiro; Aoki, Chinatsu; Hachiya, Junichi [Department of Radiology, Kyorin University School of Medicine, 6-20-2 Shinkawa, Mitaka, 181-8611, Tokyo (Japan)

    2004-02-01

    We evaluated the feasibility of MR cisternography by the balanced fast-field-echo (bFFE) sequence, comparing with that by a turbo-spin-echo (TSE) sequence, for cerebellopontine angle lesions on a 1.5-T imager (Gyroscan Intera, Philips, Best, The Netherlands). The bFFE MR cisternograms depicted target cranial nerves with less cerebrospinal fluid pulsation artifacts than TSE cisternograms and visualized an acoustic schwannoma in 6 of 44 patients with suspicion and a causative vessel of hemifacial spasm in all of 3 patients in a short scanning time (1 min 53 s). The bFFE sequence can be promising for MR cisternography in the diagnosis of cerebellopontine angle lesions. (orig.)

  14. Metastatic Adenocarcinoma of Unknown Primary in the Bilateral Cerebellopontine Angles: Case Report and Review of the Literature.

    Science.gov (United States)

    Zhang, Dao-Bao; Zheng, Nian-Dong

    2015-01-01

    Metastatic adenocarcinoma in bilateral cerebellopontine angles (CPA) is rare. We report a case and review the current literature in order to enhance recognition of metastatic adenocarcinoma in the cerebellopontine angle. A 44-year-old man was referred to the hospital with rightsided diminished hearing for 7 weeks, left-sided facial palsy for 2 weeks, and left-sided sensorineural hearing loss for 1 week. On Magnetic Resonance Imaging (MRI) two tumors in bilateral CPAs were detected. The left-sided tumor was resected and histopathological examination revealed an adenocarcinoma. Many investigations could not find the primary tumor. One should be careful with middle-aged or elderly patients with sudden progressive deficits in the VIII th or VII th cranial nerves, particularly in bilateral CPA. PMID:26617145

  15. Primary Intracranial Malignant Nerve Sheath Tumor in the Cerebellopontine Angle in a Woman with Neurofibromatosis Type 2

    OpenAIRE

    Bita Geramizadeh; Mehrzad Pourjafar; Ramin Mardani; Negar Azarpira; Saeid Farokhi

    2009-01-01

    Neurofibromatosis type 2 is an inherited disease. The mainmanifestation of the disease is the development of symmetric,non-malignant brain tumors in the region of the cranial nerveVIII usually as schwannoma. We report here a 20-year-oldwoman with primary intracranial malignant nerve sheath tumorlocated in the left cerebellopontine angle. Histologically, the tumorshowed malignant spindle cells in fascicular pattern withfocal S100 positivity on immunohistochemistry. A subtotal surgicalresection...

  16. Intraoperative Transcranial Motor-Evoked Potential Monitoring of the Facial Nerve during Cerebellopontine Angle Tumor Resection.

    Science.gov (United States)

    Cosetti, Maura K; Xu, Ming; Rivera, Andrew; Jethanamest, Daniel; Kuhn, Maggie A; Beric, Aleksandar; Golfinos, John G; Roland, J Thomas

    2012-10-01

    Objective To determine whether transcranial motor-evoked potential (TCMEP) monitoring of the facial nerve (FN) during cerebellopontine angle (CPA) tumor resection can predict both immediate and long-term postoperative FN function. Design Retrospective review. Setting Tertiary referral center. Main Outcome Measures DeltaTCMEP (final-initial) and immediate and long-term facial nerve function using House Brackmann (HB) rating scale. Results Intraoperative TCMEP data and immediate and follow-up FN outcome are reported for 52 patients undergoing CPA tumor resection. Patients with unsatisfactory facial outcome (HB >2) at follow-up had an average deltaTCMEP of 57 V, whereas those with HB I or II had a mean deltaTCMEP of 0.04 V (t = -2.6, p  2) facial function in the immediate postoperative period. Conclusion Intraoperative TCMEP of the facial nerve can be a valuable adjunct to conventional facial nerve electromyography during resection of tumors at the CPA. Intraoperative deltaTCMEP >57 V may be worrisome for long-term recovery of satisfactory facial nerve function. PMID:24083121

  17. Epidermoid cyst in the cerebellopontine angle cistern presenting as trigeminal neuralgia

    International Nuclear Information System (INIS)

    This 29-year-old male had been suffering from left trigeminal neuralgia one year prior to admission. Admission was prompted by the development of pain in the third division of the left trigeminal nerve. Physical and neurological examinations were not remarkable except for the facial pain. The orbicularis oculi reflex showed delayed latency of R1 on the affected side. CT scans performed pre- and post-contrast enhancement revealed a low density area in the left cerebellopontine angle cistern. Metrizamide CT cisternography clearly revealed the margin of the lesion as the contrast media did not enter into the low density area. A left suboccipital craniectomy was performed. The trigeminal nerve was surrounded by a thin-capsulated mass and cholesteatoma materials. Histological diagnosis was epidermoid cyst. Since this surgical procedure, the trigeminal neuralgia has not recurred for one year. Without objective neurological deficits, it is difficult to distinguish symptomatic trigeminal from idiopathic neuralgia. Therefore, minor change of the orbicularis oculi reflex should help in objectively detecting dysfunction of the trigeminal nerve. Metrizamide CT cisternography is also useful in diagnosis of cystic lesions. (author)

  18. An adult case of medulloblastoma in the cerebellopontine angle extending to the supratentorial area

    Institute of Scientific and Technical Information of China (English)

    Yasemin Benderli Cihan

    2010-01-01

    Medulloblastoma is an undifferentiated embryonic neuroepithelial tumor. It is a rare tumor in the central nervous system, with an even rarer occurrence during adulthood. It may develop at an atypical and uncommon site, such as the cerebellopontine angle (CPA), and such tumors rarely present with supratentorial extension. The present study reports an adult case of medulloblastoma in the CPA extending to the supratentorial area. The patient presented with complaints of headache, vertigo, hearing difficulty in the left ear, nausea/vomiting, and unsteady gait. Disequilibrium began 4 weeks earlier. Examination revealed normal cranial nerves, and computed tomography showed a hyperdense lesion, with a heterogeneously enhancing mass, in the left CPA region. The patient underwent a nearly total excision of the lesion in the CPA region.Histopathological examination confirmed medulloblastoma, WHO grade IV. Postoperatively, the patient received radiotherapy and remained asymptomatic for 30 months. However, he received two more surgeries for relapse and progression of medulloblastoma and eventually died. A CPA medulloblastoma with supratentorial extension is relatively rare in the clinic.

  19. Neuro-otological findings and CT scanning of cerebellopontine angle tumors

    International Nuclear Information System (INIS)

    Clinical evaluation was carried out on 13 cerebellopontine angle tumors which consisted of ten acoustic neuromas, two meningiomas and one facial nerve neurinoma. The relationship among the neurootological findings and CT scaning findings and gross appearance of the tumors were summarized as follows: 1) Many acoustic neuromas had initial symptoms of hearing loss associated with equilibrium disturbance and/or gait disturbance at the time of diagnosis of tumors. As further increase in tumor size occurs, the patients tended to complain of a great variety of neurologic symptoms and nystagmus. With further enlargement in tumor size, appearance rate of abnormality in OKP test and ETT tended to be higher. 2) The acoustic neuromas which consisted mostly of cystic mass tended to show less hearing loss and nystagmus than those which consisted mostly of solid mass. 3) Caloric response appeared abnormal in all cases of acoustic neuroma. 4) In all cases of acoustic neuroma, Stenvers view and frontal tomographic sections of petrous pyramids showed enlargement of the internal audiotory canal. Plain CT scanning of acoustic neuromas tended to reveal iso-density or low density area. Contrast enhanced CT scanning tended to reveal ring-like high density area. Acoustic neuroma with ring-like high density on the CT scanning consisted of not only cystic mass but also solid mass. 5) In cases of meningioma and facial nerve neuroma, neuro-otological findings were scanty. 6) In ABR, none of the patients showed response or the presense of wave I only or waves I and II or the abnormality of interaural latency difference. (author)

  20. Radiopertechnetate flow study: a valuable adjunct to brain scanning in the differential diagnosis of cerebello-pontine angle tumors

    International Nuclear Information System (INIS)

    Twenty-seven surgically proven acoustic neuromas were studied preoperatively with conventional brain scanning. Nine lesions were not diagnosed. Lesions less than 2.0 cm in diameter were not visualized (five patients). Lesions larger than 3.0 cm were all detected (15 patients). Lesions ranging in size from 2.0 to 3.0 cm were detected half of the time (six patients, seven lesions). Fourteen/sup 99m/Tc-pertechnetate flow studies were performed in 10 patients with acoustic neuromas. All were negative. A case of meningioma in the cerebello-potine angle and a case of arteriovenous malformation in the posterior fossa were visualized on conventional scan. The flow studies were positive and demonstrated patterns suggestive of the nature of the lesions. Flow study appears a valuable adjunct to brain scanning in the differential diagnosis of cerebello-pontine angle tumors

  1. MRI of the cerebellopontine angle in patients with cleido-cranial dysostosis; MRT der Kleinhirnbrueckenwinkelregion bei Patienten mit Dysostosis cleido-cranialis

    Energy Technology Data Exchange (ETDEWEB)

    Scherer, A.; Engelbrecht, V.; Nawatny, J.; Moedder, U. [Duesseldorf Univ. (Germany). Inst. fuer Diagnostische Radiologie; Messing-Juenger, M. [Duesseldorf Univ. (Germany). Neurochirurgische Klinik; Reifenberger, G. [Duesseldorf Univ. (Germany). Inst. fuer Neuropathologie

    2001-04-01

    Purpose: Cleidocranial dysostosis (CCD) is an autosomal dominant bone disorder in which deafness is common secondary to malformation of the middle ear structures. The study aimed at MRI evaluation of the cerebellopontine angle in 7 patients with a history of CCD - two generation spanned relatives. Material and methods: Cranial MRI in 7 patients with CCD (4 women/3 men aged between 8 and 46 years) was performed. In two patients hearing disorders were present. The examinations encompassed multi-planar spinecho sequences of the cerebellopontine angle in 3-mm slice thickness before and after administration of contrast medium. Results: The clinically most conspicuous female patient (hearing loss, ataxia, headache) showed a strongly contrast-enhancing tumor in MRI that was histologically proved to be an acoustic schwannoma. Concerning the other family members, no pathological findings were noted except for non-pneumatized mastoids. Conclusion: The first report of a patient with CCD and an acoustic schwannoma shows that in case of hearing loss in these patients also a retrocochlear cause must be considered. (orig.) [German] Ziel: Die Dysostosis cleido-cranialis (DCC) ist eine autosomal-dominant erbliche Knochenerkrankung, bei der aufgrund von Mittelohrmissbildungen gehaeuft Hoerstoerungen beobachtet werden. Wir ueberpruefen bei 7 von diesem Syndrom betroffenen Verwandten 1. und 2. Grades, ob sich kernspintomographisch Auffaelligkeiten der Kleinhirnbrueckenwinkelregion nachweisen lassen. Material und Methoden: MRT-Untersuchungen des Schaedels bei 7 Patienten mit DCC (4 Frauen, 3 Maenner im Alter zwischen 8 und 46 Jahren). Bei zwei Patienten lagen klinisch Hoerstoerungen vor. Die Bildgebung umfasste multiplanare Spin-Echo-Sequenzen und wurde im Bereich des Kleinhirnbrueckenwinkels in 3 mm Schichtdicke vor und nach Gadoliniumgabe durchgefuehrt. Ergebnisse: Die klinisch auffaelligste Patientin (progredienter Hoerverlust, Ataxie, Cephalgien) zeigte in der MRT einen kraeftig

  2. An Unusual Case of Large Posterior Fossa Neurenteric Cyst Involving Bilateral Cerebellopontine Angle Cisterns: Report of a Rare Case and Review of Literature

    International Nuclear Information System (INIS)

    Intracranial neurenteric cysts are rare cystic masses of endodermal origin lined with mucin producing low columnar or cuboidal epithelium. Approximately 141 cases have been reported so far. Most of the posterior fossa neurenteric cysts are typically small, located anteriorly to the brainstem in the midline or in the cerebellopontine angle cistern area. We present a rare, histologically proven case of a large lobulated intracranial neurenteric cyst measuring 4.2 centimeters in the maximal transverse dimension and involving bilateral cerebellopontine angle cisterns. We also present a review of the literature on this uncommon finding. Imaging features of neurenteric cyst are non-specific and it should be considered in the differential diagnosis for any intracranial extraaxial cystic lesion

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

    Directory of Open Access Journals (Sweden)

    Debebe Theodros

    2015-01-01

    Full Text Available 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.

  4. Does the location of a vascular loop in the cerebellopontine angle explain pulsatile and non-pulsatile tinnitus?

    Energy Technology Data Exchange (ETDEWEB)

    Nowe, V.; Wang, X.L.; Gielen, J.; Goethem, J.Van; Oezsarlak, Oe.; De Schepper, A.M.; Parizel, P.M. [University of Antwerp, Department of Radiology, Edegem (Belgium); Ridder, D. De [University of Antwerp, Department of Neurosurgery, Edegem (Belgium); Heyning, P.H.Van de [University of Antwerp, Department of Otorhinolaryngology, Edegem (Belgium)

    2004-12-01

    The purpose was to investigate patients with unexplained pulsatile and non-pulsatile tinnitus by means of MR imaging of the cerebellopontine angle (CPA) and to correlate the clinical subtype of tinnitus with the location of a blood vessel (in the internal auditory canal or at the cisternal part of the VIIIth cranial nerve). Clinical presentation of tinnitus and perceptive hearing loss were correlated. In 47 patients with unexplained tinnitus, an MR examination of the CPA was performed. Virtual endoscopy reconstructions were obtained using a 3D axial thin-section high-resolution heavily T2-weighted gradient echo constructive interference in steady state (CISS) data-set. High-resolution T2-weighted CISS images showed a significantly higher number of vascular loops in the internal auditory canal in patients with arterial pulsatile tinnitus compared to patients with non-pulsatile tinnitus (P<0.00001). Virtual endoscopy images were used to investigate vascular contacts at the cisternal part of the VIIIth cranial nerve in patients with low pitch and high pitch non-pulsatile tinnitus. A significantly different distribution of the vascular contacts (P=0.0320) was found. Furthermore, a correlation between the clinical presentation of non-pulsatile tinnitus (high pitch and low pitch) and the perceptive hearing loss was found (P=0.0235). High-resolution heavily T2-weighted CISS images and virtual endoscopy of the CPA can be used to evaluate whether a vascular contact is present in the internal auditory canal or at the cisternal part of the VIIIth cranial nerve and whether the location of the vascular contact correlates with the clinical subtype of tinnitus. Our findings suggest that there is a tonotopical structure of the cisternal part of the VIIIth cranial nerve. A correlation between the clinical presentation of tinnitus and hearing loss was found. (orig.)

  5. Computed tomography and magnetic resonance imaging of acquired abnormalities of the inner ear and cerebello-pontine angle; CT und MRT erworbener Veraenderungen des Innenohrs und Kleinhirnbrueckenwinkels

    Energy Technology Data Exchange (ETDEWEB)

    Grampp, S.; Czerny, C.; Henk, C.B.; Imhof, H. [Abteilung fuer Osteologie, Univ.-Klinik fuer Radiodiagnostik, Wien (Austria); Gstoettner, W. [Univ.-Klinik fuer Hals-Nasen-Ohren-Heilkunde, Frankfurt/Main (Germany)

    2003-03-01

    CT and MRI of acquired abnormalities of the inner ear and cerebello-pontine angle present themselves with very typical findings. The imaging should be adapted to the pathology looked for and either CT or MRI should be used alone or in combination.CT, especially high resolution CT (HRCT), provides an excellent bone contrast, while MRI has a much superior soft tissue contrast. Acute inflammatory changes of the inner ear are solely depicted by contrast-enhanced MRI. HRCT excellently depicts osseous changes of the inner ear and cerebellopontine angle such as chronic ossifying labyrinthitis occurring after acute labyrinthitis, otosclerotic or traumatic changes. Tumorous changes not yielding to bony changes are best delineated by MRI. Posttraumatic hemorrhage and chronic fibrotic changes within the labyrinth are depicted by MRI, only. In conclusion HRCT and MRI are excellent methods to delineate acquired abnormalities of the inner ear and cerebello-pontine angle. HRCT best depicts osseous changes while MRI best depicts soft tissue changes. HRCT and MRI are not concurrent methods but should better be used as complementary methods for imaging acquired abnormalities of inner ear and cerebellopontine angle. (orig.) [German] Bei erworbenen Veraenderungen des Innenohrs und der Kleinhirnbrueckenwinkelregion zeigen CT und MRT typische Bildcharakteristika, wobei die Bildgebung der zu suchenden Veraenderung angepasst werden sollte. Die CT liefert hochaufloesend (HRCT) einen exzellenten Knochen-, die MRT einen hervorragenden Weichteilkontrast. Akute entzuendliche Veraenderungen sind in der HRCT nicht erkennbar, sondern nur in der kontrastmittelverstaerkten MRT. Die HRCT erfasst am besten knoecherne Veraenderungen wie Ossifikationen des membranoesen Labyrinths im Rahmen einer chronischen Entzuendung, otosklerotische und traumatische Veraenderungen - selbst wenn diese nur diskret sind. Tumoroese Veraenderungen, die zu keiner ossaeren Veraenderung fuehren wie kleine Schwannome sowie

  6. Benign and malignant lesions in the region of the inner ear and cerebellopontine angle; Benigne und maligne Veraenderungen der Innenohr- und Kleinhirnbrueckenwinkelregion

    Energy Technology Data Exchange (ETDEWEB)

    Czerny, C.; Nemec, S.; Krestan, C. [Medizinische Universitaet Wien (Austria). Klinik fuer Radiodiagnostik; Gstoettner, W. [Universitaetsklinikum Frankfurt am Main (Germany). Klinik fuer HNO-Erkrankungen

    2006-03-15

    Tumorous lesions in the region of the inner ear and cerebellopontine angle are very rare and can be classified into benign and malignant disease forms. This contribution presents and explains the CT and MRI characteristics of these tumors. High-resolution computed tomography (HRCT) in the axial projection is applied for evaluation in the high-resolution bone window. The coronary slices can be reconstructed from the axial datasets or in individual cases examined in the coronary plane. HRCT excellently demonstrates osseous lesions and in individual cases - e.g., exostoses - it can simply suffice to perform HRCT of the temporal bone, while HRCT is also excellent for detecting osseous lesions to determine whether the tumor is benign or malignant. MRI, on the other hand, excellently shows the extent of tumor spread because of its superb soft tissue contrast. Consequently, HRCT and MRI images of the inner ear and cerebellopontine angle provide meaningful information for visualization and classification of tumorous lesions. The two methods should not be considered as competing but rather as complementary and among other aspects exert considerable influence on the therapeutic approach. (orig.) [German] Tumoroese Veraenderungen der Innenohr- und Kleinhirnbrueckenwinkelregion sind sehr selten und koennen in benigne und maligne Erkrankungen eingeteilt werden. In dieser Arbeit sollen die CT- und MRT-Charakteristika dieser Tumoren erlaeutert und dargestellt werden. Die hochaufloesende Computertomographie (HRCT) kommt in axialer Schichtfuehrung, in der Auswertung im hochaufloesenden Knochenfenster, zum Einsatz. Die koronalen Schichten koennen aus den axialen Datensaetzen rekonstruiert oder in einzelnen Faellen in koronaler Ebene untersucht werden. Die HRCT zeigt exzellent die knoechernen Veraenderungen, und es kann in Einzelfaellen - wie z. B. bei Exostosen - genuegen, lediglich eine HRCT des Schlaefenbeins anzufertigen, waehrend auch mit der HRCT exzellent Knochenveraenderungen

  7. Epidermoid cyst in the cerebellopontine angle cistern presenting as trigeminal neuralgia. Diagnostic values of the orbicularis oculi reflex and metrizamide CT cisternography - case report -

    Energy Technology Data Exchange (ETDEWEB)

    Ueda, Takashi; Goya, Tomokazu; Kinoshita, Kazuo (Miyazaki Medical College, Miyazaki (Japan)); Fukui, Masashi

    1983-05-01

    This 29-year-old male had been suffering from left trigeminal neuralgia one year prior to admission. Admission was prompted by the development of pain in the third division of the left trigeminal nerve. Physical and neurological examinations were not remarkable except for the facial pain. The orbicularis oculi reflex showed delayed latency of R/sub 1/ on the affected side. CT scans performed pre- and post-contrast enhancement revealed a low density area in the left cerebellopontine angle cistern. Metrizamide CT cisternography clearly revealed the margin of the lesion as the contrast media did not enter into the low density area. A left suboccipital craniectomy was performed. The trigeminal nerve was surrounded by a thin-capsulated mass and cholesteatoma materials. Histological diagnosis was epidermoid cyst. Since this surgical procedure, the trigeminal neuralgia has not recurred for one year. Without objective neurological deficits, it is difficult to distinguish symptomatic trigeminal from idiopathic neuralgia. Therefore, minor change of the orbicularis oculi reflex should help in objectively detecting dysfunction of the trigeminal nerve. Metrizamide CT cisternography is also useful in diagnosis of cystic lesions.

  8. Pneumocephalus in cerebellopontine angle and meningitis secondary to chronic otitis media in a child

    OpenAIRE

    Shailendra Ratre; Yadram Yadav; Sushma Choudhary; Vijay Parihar; Yatin Kher; Ketan Hedaoo

    2015-01-01

    Pneumocephalus is a rare complication of chronic otitis media. Despite its rarity intra-cranial air carries a potential risk of increased intra-cranial pressure or meningitis, which requires immediate therapy. A 10-year-old child presented to us with complaints of fever, headache, vomiting, and decreased hearing from left ear. He had history of left ear discharge since 2 years. Clinical examination revealed neck rigidity and left chronic otitis media. Contrast enhanced computed axial tomograp...

  9. Cerebellopontine Choroid Plexus Papilloma: Case Report

    International Nuclear Information System (INIS)

    We present the case of an adult female patient who presented with a mass in the cerebellopontine angle, corresponding to a choroid plexus papilloma. Due to this uncommon location, we report this case and describe its imaging characteristics and the possible differential diagnoses.

  10. Imaging of cerebellopontine angle lesions: an update. Part 2: intra-axial lesions, skull base lesions that may invade the CPA region, and non-enhancing extra-axial lesions

    Energy Technology Data Exchange (ETDEWEB)

    Bonneville, Fabrice; Chiras, Jacques [Pitie-Salpetriere Hospital, Department of Neuroradiology, Paris (France); Savatovsky, Julien [Adolphe de Rothschild Foundation, Department of Radiology, Paris (France)

    2007-11-15

    Computed tomography (CT) and magnetic resonance (MR) imaging reliably demonstrate typical features of vestibular schwannomas or meningiomas in the vast majority of mass lesions responsible for cerebellopontine angle (CPA) syndrome. However, a large variety of unusual lesions can also be encountered in the CPA. Covering the entire spectrum of lesions potentially found in the CPA, these articles explain the pertinent neuroimaging features that radiologists need to know to make clinically relevant diagnoses in these cases, including data from diffusion- and perfusion-weighted imaging or MR spectroscopy, when available. A diagnostic algorithm based on the lesion's site of origin, shape and margins, density, signal intensity and contrast material uptake is also proposed. Non-enhancing extra-axial CPA masses are cystic (epidermoid cyst, arachnoid cyst, neurenteric cyst) or contain fat (dermoid cyst, lipoma). Tumours can also extend into the CPA by extension from the skull base (paraganglioma, chondromatous tumours, chordoma, cholesterol granuloma, endolymphatic sac tumour). Finally, brain stem or ventricular tumours can present with a significant exophytic component in the CPA that may be difficult to differentiate from an extra-axial lesion (lymphoma, hemangioblastoma, choroid plexus papilloma, ependymoma, glioma, medulloblastoma, dysembryoplastic neuroepithelial tumour). (orig.)

  11. Cerebellopontine angle pilocytic astrocytoma mimicking acoustic schwannoma

    Energy Technology Data Exchange (ETDEWEB)

    Takada, Y.; Ohno, K.; Tamaki, M.; Hirakawa, K. [Dept. of Neurosurgery, Tokyo Medical and Dental Univ. (Japan)

    1999-12-01

    We describe a case of pilocytic astrocytoma of the cerebellum mimicking an acoustic schwannoma. The tumour protruded into the porus acusticus and enlarged the internal auditory meatus, which is a quite unusual characteristic of glial tumours. (orig.)

  12. Cerebellopontine angle pilocytic astrocytoma mimicking acoustic schwannoma

    International Nuclear Information System (INIS)

    We describe a case of pilocytic astrocytoma of the cerebellum mimicking an acoustic schwannoma. The tumour protruded into the porus acusticus and enlarged the internal auditory meatus, which is a quite unusual characteristic of glial tumours. (orig.)

  13. MRI of the regions of inner ear and cerebellopontine angle using a 3D T2-weighted turbo spin-echo sequence. Comparison with conventional 2D T2-weighted turbo spin-echo sequences and T1-weighted spin-echo sequences

    International Nuclear Information System (INIS)

    Purpose: To assess the value of a three-dimensional (3D) T2-weighted turbo spin-echo sequence (3D T2-TSE) in comparison to conventional two-dimensional (2D) T2-weighted TSE and unenhanced and enhanced T1-weighted spin-echo sequences (SE) in imaging anatomic structures and pathologic changes of the inner ear and cerebellopontine angle. Patients and methods: The inner ear and cerebellopotine angle were investigated by MRI in three healthy volunteers and 18 patients performing a 2D T2-weighted turbo spin-echo sequence and a 3D T2-TSE in the axial plane. In the patient study, 2D T1-weighted SE sequences both before and after the i.v. injection of gadopentate dimeglumine in both the axial and coronal plane were performed in addition. Results: Only the 3D T2-TSE enabled an accurate imaging of the anatomic structures. In cases of pathology, the 3D T2-TSE provided additional information to the performed 2D sequences. The combination of the 3D T2-TSE with unenhanced and enhanced 2D T1-weighted SE enabled the most accurate diagnosis in case of pathology. Conclusions: Accurate depiction of anatomic structures of the inner ear and cerebellopontine angle could be obtained by 3D T2-TSE only. The most accurate diagnosis in cases of pathology was provided by the combination of the 3D T2-TSE with unenhanced and enhanced 2D T1-weighted spin-echo sequences. (orig.)

  14. Malformação da transição crânio-vertebral como causa de síndrome do ângulo ponto-cerebelar: relato de dois casos Cerebello-pontine angle syndrome associated with cranio-vertebral malformation: report of two cases

    Directory of Open Access Journals (Sweden)

    Amauri Batista da Silva

    1972-03-01

    Full Text Available Os autores relatam dois casos de síndrome do ângulo ponto-cerebelar nos quais não havia neoplasia nessa região. Ambos os pacientes apresentavam uma associação de impressão basilar com síndrome de Arnold-Chiari. Após cirurgia descompressiva de fossa posterior os casos evoluiram favoravelmente com a diminuição progressiva dos sintomas neurológicos, restando apenas, no segundo paciente, certo grau de paralisia e de espasmo facial, à direita. São feitas considerações em tôrno das causas mais freqüentes da síndrome do ângulo ponto-cerebelar, bem como acêrca dos quadros clínicos mais usualmente encontrados em doentes que apresentam malformações da transição crânio-vertebral. Finalmente, os autores tecem breves considerações a respeito do possível mecanismo lesionai do VIII, do V e do VII nervos cranianos nos dois casos relatados.Two cases of cerebelo-pontine angle syndrome associated with basilar impression and Arnold-Chiari malformation are reported. In both cases neuroradiological studies and surgical exploration failled to demonstrate any space occupying lesion. After surgery the patients progressively recovered disapearing the neurological symptoms except for a slaight hemifacial spasm that remained in case 2. Clinical signs present in cerebello-pontine angle lesions and the occipito-cervical malformations are discussed. A possible mechanism to explain the association of both conditions is discussed.

  15. Mefenamic acid-induced bilateral transient myopia, secondary angle closure glaucoma and choroidal detachment

    OpenAIRE

    Vishwakarma Parag; Raman Ganesh; Sathyan P

    2009-01-01

    Drug-induced secondary angle closure is quite common and in the majority of cases simply stopping the medication leads to rapid reversal of the condition and resolution of glaucoma. We describe here a patient who presented with secondary angle closure glaucoma and myopia following mefenamic acid ingestion which was managed successfully by stopping the medication, symptomatic treatment and reassurance.

  16. The effects of impurities and incidence angle on the secondary electron emission of Ni(110)

    Science.gov (United States)

    Lazar, Hadar; Patino, Marlene; Raitses, Yevgeny; Koel, Bruce; Gentile, Charles; Feibush, Eliot

    The investigation of secondary electron emission (SEE) of conducting materials used for magnetic fusion devices and plasma thrusters is important for determining device lifetime and performance. Methods to quantify the secondary electron emission from conducting materials and to characterize the effects that impurities and incidence angles have on secondary electron emission were developed using 4-grid low energy electron diffraction (LEED) optics. The total secondary electron yield from a Ni(110) surface was continuously measured from the sample current as surface contamination increased from reactions with background gases in the ultrahigh vacuum chamber. Auger electron spectroscopy (AES) and temperature programmed desorption (TPD) were used to examine the composition and impurity levels on the Ni(110) surface. The total secondary electron yield was also measured at different incidence angles. Thank you to the Princeton Plasma Physics Laboratory (PPPL) and the Department of Energy (DOE) for the opportunity to work on this project through the Science Undergraduate Laboratory Internships (SULI).

  17. The effect of impurities and incident angle on the secondary electron emission of Ni(110)

    Science.gov (United States)

    Lazar, Hadar; Patino, Marlene; Raitses, Yevgeny; Koel, Bruce E.; Gentile, Charles; Feibush, Eliot

    2015-11-01

    The investigation of secondary electron emission (SEE) of conducting materials used for magnetic fusion devices and plasma thrusters is important for determining device lifetime and performance. Methods to quantify the secondary electron emission from conducting materials and to characterize the effects that impurities and incident angles have on secondary electron emission were developed using 4-grid low energy electron diffraction (LEED) optics. The total secondary electron yield from a Ni(110) surface was continuously measured from the sample current as surface contamination increased from reactions with background gases in the ultrahigh vacuum chamber. Auger electron spectroscopy (AES) and temperature programmed desorption (TPD) were used to examine the composition and impurity levels on the Ni(110) surface. The total secondary electron yield was also measured at different incident angles. Thank you to the Princeton Plasma Physics Laboratory and the Department of Energy for the opportunity to work on this project through the Science Undergraduate Laboratory Internships.

  18. A CASE OF ANGLE - CLOSURE GLAUCOMA SECONDARY TO CHRONIC ANTERIOR UVEITIS

    Directory of Open Access Journals (Sweden)

    Pandu

    2015-05-01

    Full Text Available Elevation of intraocular pressure secondary to intraocular inflammation frequently presents a diagnostic & therapeutic challenge. Secondary glaucoma is more common in chronic anterior uveitis. We present a case of the same, a 25 years old female presented with headache and redness in right eye. She gives history of gradual loss of vision in both eyes 15 years back. On examination there was no perception of light in both eyes and pupillary reactions were absent in both eyes. Anterior segment of right eye showed circumciliary congestion, corneal edema, peripheral anterior synechiae, Aqueous flare of grade 1+, annular posterior synechiae with complicated cataract. Anterior segment of left eye showed shallow anterior chamber with closed angles and complicated cataract. A clinical diagnosis of secondary angle closure glaucoma was made. Once IOP was under control she underwent synechotomy and lens extraction in right eye and lens extraction in left eye. Post operatively corneal edema and congestion resolved. Fundus examination revealed glaucomatous optic atrophy. Thus, prompt and early treatment of anterior uveitis is needed to prevent secondary angle closure glaucoma. We report a case of secondary angle closure glaucoma in a young female patient.

  19. Trigeminal Neuralgia Caused by Pontocerebellar Angle Epidermoid Tumor: A Case Report and Review of Literature

    OpenAIRE

    Muhammet Bahadır Yılmaz; Semra Yılmaz; Ayhan Tekiner

    2015-01-01

    Trigeminal neuralgia (TN) is the most commonly seen craniofacial pain syndrome. Etiology of TN can be divided into classical (idiopathic and vascular compression) and symptomatic (tumor, demyelinating, and ischemic) types. Especially, symptomatic trigeminal neuralgia is seen with tumors located in the cerebellopontine angle. Epidermoid tumors comprise about 1% of all brain tumors and 5% of tumors located in the cerebellopontine angle. These tumors may present with trigeminal neuralgia due to ...

  20. Quaternion-based definition of protein secondary structure straightness and its relationship to Ramachandran angles.

    Science.gov (United States)

    Hanson, Robert M; Kohler, Daniel; Braun, Steven G

    2011-07-01

    We describe here definitions of "local helical axis" and "straightness" that are developed using a simple quaternion-based analysis of protein structure without resort to least-squares fitting. As part of this analysis, it is shown how quaternion differences can be visualized to depict accurately the local helical axis relating any two adjacent amino acid residues in standard, nonidealized proteins. Three different options for the definition of amino acid residue orientation in terms of quaternion frames are described. Two of these, the "C(α) frame" and the "P frame," are shown to be correlated strongly with a simple approximate measure derived solely from Ramachandran angles. The relationship between quaternion-based straightness and recognized DSSP-derived secondary structure motifs is discussed. PMID:21557319

  1. Topiramate-induced Myopic Shift and Bilateral Secondary Angle-closure Glaucoma

    Directory of Open Access Journals (Sweden)

    Özgür Örüm

    2012-03-01

    Full Text Available In this case report, we discuss a 24-year-old female patient with diagnosis of epilepsy who developed myopia and acute bilateral angleclosure glaucoma after 7 days of treatment with topiramate. The patient had also been taking duloxetine daily for six months with diagnosis of depression. Both topiramate and duloxetine have been related to the increase of intraocular pressure and the development of glaucoma. This case report highlights the need for being suspicious about acute bilateral angle-closure glaucoma, which is reversible by supportive treatment in patients using topiramate. We recommend that particular attention should be paid in prescribing topiramate to patients who are already under treatment with duloxetine or other antidepressants with a similar mechanism of action and that patients should be informed about possible side effects. (Turk J Oph thal mol 2012; 42: 154-6

  2. On correlation between protein secondary structure, backbone bond angles, and side-chain orientations

    CERN Document Server

    Lundgren, Martin

    2012-01-01

    We investigate the fine structure of the sp3 hybridized covalent bond geometry that governs the tetrahedral architecture around the central C$_\\alpha$ carbon of a protein backbone, and for this we develop new visualization techniques to analyze high resolution X-ray structures in Protein Data Bank. We observe that there is a correlation between the deformations of the ideal tetrahedral symmetry and the local secondary structure of the protein. We propose a universal coarse grained energy function to describe the ensuing side-chain geometry in terms of the C$_\\beta$ carbon orientations. The energy function can model the side-chain geometry with a sub-atomic precision. As an example we construct the C$_\\alpha$-C$_\\beta$ structure of HP35 chicken villin headpiece. We obtain a configuration that deviates less than 0.4 \\.A in root-mean-square distance from the experimental X-ray structure.

  3. Trigeminal Neuralgia Caused by Cerebellopontine Angle Arteriovenous Malformation Treated With Gamma Knife Radiosurgery.

    Science.gov (United States)

    Işik, Semra; Ekşi, Murat Şakir; Yilmaz, Baran; Toktaş, Zafer Orkun; Akakin, Akin; Kiliç, Türker

    2016-01-01

    Trigeminal neuralgia is a facial pain syndrome characterized as sudden onset and lightening-like sensation over somatosensorial branch(es) of fifth cranial nerve. Rarely, some underlying diseases or disorders could be diagnosed, such as multiple sclerosis, brain tumors, and vascular malformations. The authors present a 47-year-old man with trigeminal neuralgia over left V2 and V3 dermatomes. He had a previous transarterial embolization and long use of carbamazepine with partial response to treatment. Gamma knife radiosurgery (GKR) was planned. A marginal dose of 15 Gy was given to 50% isodose line. His pain was relieved by GKR in 1.5 years. Treatment of posterior fossa arteriovenous malformations causing trigeminal neuralgia, with GKR has a very limited use in the literature. It, however, is obvious that success rate as pain relief, in a very challenging field of functional neurosurgery, is satisfactory. Large series, however, are in need to make a more comprehensive statement about efficacy and safety of the procedure in these pathologies. PMID:26674920

  4. Air cisternography of the cerebellopontine angle using high-resolution computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, D.W.

    1984-05-01

    While high-resolution CT/air cisternography is considered the preferred method of investigating non-enhancing or small acoustic neuromas, it is not without pitfalls. Eight such studies were reviewed, emphasizing procedural problems and sources of interpretive error. Two patients presented difficulty in transporting the air bolus due to a spinal cord tumor coexisting with bilaterial acoustic neuromas; spinal cord decompression was required in one case. Three potential false positives were avoided by persistent efforts to fill the internal auditory canal. Of 4 patients thought to have a tiny acoustic neuroma, elective vestibular nerve section in 2 revealed no evidence of tumor.

  5. A rare cause of infant facial paralysis: atypical teratoid rhabdoid tumour located in the cerebellopontine angle

    OpenAIRE

    Öztürk, Mehmet; Siğirci, Ahmet; Karadağ, Neşe

    2015-01-01

    Atypical teratoid rhabdoid tumour (ATRT) is a rare malignant tumour of the central nervous system with embryonal roots. The majority are seen in early childhood and location is often in the posterior fossa. Surgery, radiotherapy and chemotherapy are used in treatment. Knowledge of the localisation of the mass preoperatively is necessary for direction of the chemoradiotherapy and sufficient resection in surgery. Differentiation from other brain tumours is important because of poor prognosis an...

  6. Enterococcal cerebellopontine angle abscess in a 12-year-old female

    Directory of Open Access Journals (Sweden)

    Sonavane Alka

    2010-01-01

    Full Text Available 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.

  7. ESTIMATION OF WATER ENTRY FORCES, SPRAY PARAMETERS AND SECONDARY IMPACT OF FIXED WIDTH WEDGES AT EXTREME ANGLES USING FINITE ELEMENT BASED FINITE VOLUME AND VOLUME OF FLUID METHODS

    Directory of Open Access Journals (Sweden)

    Roya Shademani

    2016-03-01

    Full Text Available In this paper, water entry of wedges with deadrise angles ranging from 10 to 80 degrees at two different velocities is simulated. Impact forces, spray parameters, cavity formation above the chine, and secondary impact forces due to the cavity formation are investigated with particular focus on the extreme angles. To this end, a two dimensional two-phase Finite-Element based Finite-Volume (FEM-FVM code is developed and validated against experimental data with good compliance. Free surface modeling in this software is accomplished by applying Volume of Fluid (VOF method. In addition to the extraction of impact forces, secondary impact forces, spray characteristics, and cavity formation, it is demonstrated that there is a combined critical length and entry velocity where the spray formation stops and the spray vanishes. It is also shown that the cavity and secondary impact do not occur under these circumstances. Moreover, it is concluded that for these particular cases, there is a maximum secondary impact force that occurs for the deadrises angles less than 20o.

  8. Secondary radiation measurements for particle therapy applications: Charged secondaries produced by 4He and 12C ion beams in a PMMA target at large angle

    CERN Document Server

    Rucinski, A; Battistoni, G; Collamati, F; Faccini, R; Frallicciardi, P M; Mancini-Terracciano, C; Marafini, M; Mattei, I; Muraro, S; Paramatti, R; Piersanti, L; Pinci, D; Russomando, A; Sarti, A; Sciubba, A; Camillocci, E Solfaroli; Toppi, M; Traini, G; Voena, C; Patera, V

    2016-01-01

    Measurements performed with the purpose of characterizing the charged secondary radiation for dose release monitoring in particle therapy are reported. Charged secondary yields, energy spectra and emission profiles produced in poly-methyl methacrylate (PMMA) target by 4He and 12C beams of different therapeutic energies were measured at 60 and 90 degree with respect to the primary beam direction. The secondary yields of protons produced along the primary beam path in PMMA target were obtained. The energy spectra of charged secondaries were obtained from time-of-flight information, whereas the emission profiles were reconstructed exploiting tracking detector information. The measured charged secondary yields and emission profiles are in agreement with the results reported in literature and confirm the feasibility of ion beam therapy range monitoring using 12C ion beam. The feasibility of range monitoring using charged secondary particles is also suggested for 4He ion beam.

  9. Enhanced production of 24Na by wide-angle secondaries produced in the interaction of relativistic carbon ions with copper

    International Nuclear Information System (INIS)

    Radiochemical activation techniques were used to study the behaviour of projectile fragments formed in the interaction of 44 GeV 12C ions within thick Cu-targets. After a short review of the results obtained hitherto with this Cu-target technique, the interaction of 44 GeV 12C with several copper target configurations yielding the deep spallation product 24Na is described. Energetic fragments which are emitted into lab angles 1000, appear to produce more :2:4Na (by about one order of magnitude) than calculated with a phenomenological model. An intranuclear cascade model was also used, giving a discrepancy of a factor of two between experiment and theory. 55 refs.; 15 figs.; 6 tabs

  10. Metabolomics by Proton High-Resolution Magic-Angle-Spinning Nuclear Magnetic Resonance of Tomato Plants Treated with Two Secondary Metabolites Isolated from Trichoderma.

    Science.gov (United States)

    Mazzei, Pierluigi; Vinale, Francesco; Woo, Sheridan Lois; Pascale, Alberto; Lorito, Matteo; Piccolo, Alessandro

    2016-05-11

    Trichoderma fungi release 6-pentyl-2H-pyran-2-one (1) and harzianic acid (2) secondary metabolites to improve plant growth and health protection. We isolated metabolites 1 and 2 from Trichoderma strains, whose different concentrations were used to treat seeds of Solanum lycopersicum. The metabolic profile in the resulting 15 day old tomato leaves was studied by high-resolution magic-angle-spinning nuclear magnetic resonance (HRMAS NMR) spectroscopy directly on the whole samples without any preliminary extraction. Principal component analysis (PCA) of HRMAS NMR showed significantly enhanced acetylcholine and γ-aminobutyric acid (GABA) content accompanied by variable amount of amino acids in samples treated with both Trichoderma secondary metabolites. Seed germination rates, seedling fresh weight, and the metabolome of tomato leaves were also dependent upon doses of metabolites 1 and 2 treatments. HRMAS NMR spectroscopy was proven to represent a rapid and reliable technique for evaluating specific changes in the metabolome of plant leaves and calibrating the best concentration of bioactive compounds required to stimulate plant growth. PMID:27088924

  11. Value of blink reflex in assessing V and VII nerve function in patients with C. P. Angle tumours— a prospective study of 75 patients

    OpenAIRE

    Mahapatra, A. K.; A. K. Singh

    1997-01-01

    This propsective study analyses the role of blink reflex (BR) in 75 patients with Cerebellopontine Angle (CPA) tumours. The aim was to find out the subclinical involvement from the blink reflex findings. Fifth nerve was clinically involved in 82.7% patients while, BR was able to detect afferent abnormality only in 54% patients. The seventh nerve was clinically involved in 74.7% and blink reflex could detect the efferent abnormality is 72% patients. Thus, clinicoelectrophysiological correlatio...

  12. An Alternative to Angle ANB in the Assessment of Sagittal Discrepancy: A Case for W angle, M-axis and G-axis based on a Secondary Analysis of Clinical Trial Data

    OpenAIRE

    Trenouth, M. J.; S. R. Desmond

    2015-01-01

    Introduction: The objective was to test if W angle was a superior method of measuring skeletal change over angle ANB. The design was to re-analyse the results of a previously performed prospective, randomized controlled clinical trial with two parallel groups. The setting was the Orthodontic department, Royal Preston District General Hospital, Preston, United Kingdom. Method: The participants were 26 patients randomly selected from a previous trial, aged 9-17 years undergoin...

  13. 不同二次风角度的W炉冷态流场实验研究%Influence of secondary air angle on flow field in down-fired furnace determined by cold-flow modeling experiment

    Institute of Scientific and Technical Information of China (English)

    杨文闯; 杨卫娟; 周志军; 袁炜东; 陈瑶姬; 周俊虎; 岑可法

    2013-01-01

    针对燃煤W火焰锅炉氮氧化物排放高的问题,提出新型W火焰锅炉燃烧技术——热风包裹低NOx燃烧技术(HAP),并对该技术进行冷态模化实验研究.HAP技术在常规W炉的基础上,在下炉膛增加了冷灰斗二次风和炉底二次风.冷态模化实验表明:相比于常规的W锅炉,HAP技术的炉内流场更优化,一次风下探深度大,炉内充满度高,并且壁面未出现严重的贴壁流动,结渣风险较小.通过对前后墙二次风和冷灰斗二次风的不同倾角的实验研究发现:倾角为45°的前后墙二次风具有较好的下探深度和炉膛充满度,避免了贴壁流动现象;增大冷灰斗二次风入射角度可以减小一次风下探深度,使得贴壁流动现象加剧.炉膛充满度随着冷灰斗二次风倾角的逐渐增大呈现先增大后减小的趋势,在66°时达到最大值.%Focusing on the problems of high NOx emissions in down fired boilers, a new combustion technology was presented for down fired boilers, hot air packing low-NOx combustion technology (HAP), and its cold-flow modeling experiments were conducted. HAP technology adds the secondary hot-air ports in the furnace hopper and bottom on the basis of the prior down fired boiler. The cold-flow modeling experiments prove that HAP technology has a much better airflow distribution compared with the prior W flame technology in the lower furnace. HAP technology produces a deeper penetration depth of the primary air and a higher filling fullness of air flow in the lower furnace. The adherent air flow towards the furnace wall does not appear obviously, which implies little risk of slagging. Different injection angles of the front and rear walls' secondary hot-air and the hopper secondary hot-air were researched. The wall secondary air with the injection angles of 45° makes a deeper penetration depth, higher filling fullness of air flow and good adherent air flow. Penetration depth of the primary air decreased and

  14. Scoliosis angle

    International Nuclear Information System (INIS)

    The most commonly used methods of assessing the scoliotic deviation measure angles that are not clearly defined in relation to the anatomy of the patient. In order to give an anatomic basis for such measurements it is proposed to define the scoliotic deviation as the deviation the vertebral column makes with the sagittal plane. Both the Cobb and the Ferguson angles may be based on this definition. The present methods of measurement are then attempts to measure these angles. If the plane of these angles is parallel to the film, the measurement will be correct. Errors in the measurements may be incurred by the projection. A hypothetical projection, called a 'rectified orthogonal projection', is presented, which correctly represents all scoliotic angles in accordance with these principles. It can be constructed in practice with the aid of a computer and by performing measurements on two projections of the vertebral column; a scoliotic curve can be represented independent of the kyphosis and lordosis. (Auth.)

  15. Clinical observation of uveitis secondary angle-closure glaucoma therapy%葡萄膜炎继发闭角型青光眼治疗的临床观察

    Institute of Scientific and Technical Information of China (English)

    侯习武; 杨茹

    2014-01-01

    目的:虹膜激光切除术治疗葡萄膜炎继发闭角型青光眼的临床效果。方法回顾性分析23例32眼葡萄膜炎继发闭角型青光眼给予虹膜激光切除术后临床资料,通过视力、眼压观察治疗情况。结果术前眼压25~40 mmHg(1 mmHg=0.133 kPa),术后终末眼压为12~21 mmHg,随访期间31眼(96.88%)眼压在正常范围内;术后视力≥0.5者14眼(43.74%),较术前视力≥0.5者3眼(9.38%)明显提高。结论虹膜激光切除术治疗葡萄膜炎继发性闭角型青光眼是一种安全有效的方法。%Objective Clinical effect of iris laser resection in the treatment of uveitis secondary angle-closure glaucoma. Methods A retrospective analysis of 23 patients (32 eyes) with uveitis secondary angle-closure glaucoma were performed iris laser resection, and observation of treatment by vision and intraocular pressure. Results The preoperative intraocular pressure was 25~40 mmHg (1 mmHg=0.133 kPa) which decreased to postoperative intraocular pressure of 12~21 mmHg. 31 eyes(96.88%)was normal after follow 6 months.3 eyes(9.38%) had a vision of≥0.5 of preoperative, 14 eyes (43.74%) had a vision of≥0.5 of postoperative, the vision of postoperative was increased obviously. Conclusion Iris laser resection in the treatment of uveitis secondary angle-closure glaucoma is a safe and effective method.

  16. The modified lateral supraorbital approach for tumors of the petroclival junction extending into the anterior cerebellopontine area.

    Science.gov (United States)

    Lim, Jaejoon; Cho, Kyunggi

    2016-05-01

    Various surgical approaches for the removal of meningioma and trigeminal schwannoma in the petroclival junction (PCJ) and anterior cerebellopontine area (CPA) have been described previously. In this study, we compared the surgical outcomes of the combined petrosal approach and a modified lateral supraorbital (MLSO) approach and evaluated the reliability and safety of the MLSO approach. Fifty patients underwent surgical treatment using the combined petrosal or MLSO approach between 1996 and 2011. We retrospectively analyzed the clinical data and compared the two approaches. Among 50 patients, 27 patients underwent operation through the combined petrosal approach and 23 underwent operation through the MLSO approach. The operation time of the MLSO approach was significantly shorter than that of the combined petrosal approach (p = 0.03). There was no significant difference in the gross total resection rate between the two approaches (p = 0.67). After the operation, the improvement in Karnofsky performance score and Mean Glasgow outcomes scales were better in the MLSO approach, but without statistical significance (p = 0.723, p = 0.20 respectively). Complications occurred more often with the combined petrosal approach than with MLSO. Facial nerve palsy was the most common complication, followed by hearing difficulty. The frequency of these two complications was higher in the combined petrosal approach. Various tumors occurring in the PCJ and anterior CPA remain a challenging problem for neurosurgeons. The new modified approach of MLSO yielded good surgical results for these tumors compared to the combined petrosal approach. Therefore, the MLSO approach might be a good option for removal of tumors in the PCJ including anterior CPA. PMID:26886578

  17. Chemical state of boron in coal fly ash investigated by focused-ion-beam time-of-flight secondary ion mass spectrometry (FIB-TOF-SIMS) and satellite-transition magic angle spinning nuclear magnetic resonance (STMAS NMR).

    Science.gov (United States)

    Hayashi, Shun-ichi; Takahashi, Takafumi; Kanehashi, Koji; Kubota, Naoyoshi; Mizuno, Kaoru; Kashiwakura, Shunsuke; Sakamoto, Tetsuo; Nagasaka, Tetsuya

    2010-08-01

    The chemical states of boron in coal fly ash, which may control its leaching into the environment, were investigated by focused-ion-beam time-of-flight secondary ion mass spectrometry (FIB-TOF-SIMS) and satellite-transition magic angle spinning nuclear magnetic resonance (STMAS NMR) spectroscopy. The distribution of boron on the surface and in the interior of micron-sized fly ash particles was directly observed by FIB-TOF-SIMS. Coordination numbers of boron and its bonding with different atoms from particles of bulk samples were investigated by STMAS NMR. Boron in coal fly ash with relatively poor leaching characteristics appears as trigonal BO(3) and coexists with Ca and Fe at the outer layer of every particle and inside CaO-MgO particles. In contrast, boron in coal fly ash with better leaching characteristics appears as CaO- or MgO-trigonal BO(3) and tetragonal BO(4), and it is distributed only on the outer surface of each ash particle without showing any correlation with a particular element. PMID:20570315

  18. Systematic variations in divergence angle

    CERN Document Server

    Okabe, Takuya

    2012-01-01

    Practical methods for quantitative analysis of radial and angular coordinates of leafy organs of vascular plants are presented and applied to published phyllotactic patterns of various real systems from young leaves on a shoot tip to florets on a flower head. The constancy of divergence angle is borne out with accuracy of less than a degree. It is shown that apparent fluctuations in divergence angle are in large part systematic variations caused by the invalid assumption of a fixed center and/or by secondary deformations, while random fluctuations are of minor importance.

  19. Perception of perspective angles

    NARCIS (Netherlands)

    Erkelens, C.J.

    2015-01-01

    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 bet

  20. An allograft mouse model for the study of hearing loss secondary to vestibular schwannoma growth.

    Science.gov (United States)

    Bonne, Nicolas-Xavier; Vitte, Jérémie; Chareyre, Fabrice; Karapetyan, Gevorg; Khankaldyyan, Vazgen; Tanaka, Karo; Moats, Rex A; Giovannini, Marco

    2016-08-01

    Vestibular schwannoma is a benign neoplasm arising from the Schwann cell sheath of the auditory-vestibular nerve. It most commonly affects both sides in the genetic condition Neurofibromatosis type 2, causing progressive high frequency sensorineural hearing loss. Here, we describe a microsurgical technique and stereotactic coordinates for schwannoma cell grafting in the vestibular nerve region that recapitulates local tumor growth in the cerebellopontine angle and inner auditory canal with resulting hearing loss. Tumor growth was monitored by bioluminescence and MRI in vivo imaging, and hearing assessed by auditory brainstem responses. These techniques, by potentially enabling orthotopic grafting of a variety of cell lines will allow studies on the pathogenesis of tumor-related hearing loss and preclinical drug evaluation, including hearing endpoints, for NF2-related and sporadic schwannomas. PMID:27177628

  1. Retromastoid-sub occipital: A novel approach to cerebello pontine angle in acoustic neuroma surgery-our experience in 21 cases

    Directory of Open Access Journals (Sweden)

    P K Nayak

    2011-01-01

    Full Text Available Background: Acoustic neuroma surgery poses significant challenges regarding definite management and preservation of hearing and the facial nerve are of great concern. Aim: To analyze the efficacy of the retromastoid approach in acoustic neuroma surgery. Materials and Methods: Tumors operated between January 2002 and December 2008, by the authors, using the retromastoid approach, were analyzed. Twenty-one patients who presented with acoustic tumor were considered for this study. Discussion: Precise knowledge of the neuroanatomy in the cerebellopontine angle is the key to success and microsurgical technique is the sole factor for good outcome. Conclusion: Retromastoid, in fact is the approach to the skull base with minimal or no damage to neurovascular structures, in contrast to the translabyrinthine or presigmoid approach.

  2. Secondary parkinsonism

    Science.gov (United States)

    Parkinsonism - secondary; Atypical Parkinson disease ... to be less responsive to medical therapy than Parkinson disease. ... Unlike Parkinson disease, some types of secondary parkinsonism may stabilize or even improve if the underlying cause is treated. ...

  3. Reading Angles in Maps

    Science.gov (United States)

    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…

  4. Optimal reconstruction angles

    International Nuclear Information System (INIS)

    The question of optimal projection angles has recently become of interest in the field of reconstruction from projections. Here, studies are concentrated on the n x n pixel space, where literative algorithms such as ART and direct matrix techniques due to Katz are considered. The best angles are determined in a Gauss--Markov statistical sense as well as with respect to a function-theoretical error bound. The possibility of making photon intensity a function of angle is also examined. Finally, the best angles to use in an ART-like algorithm are studied. A certain set of unequally spaced angles was found to be preferred in several contexts. 15 figures, 6 tables

  5. Photoelectric angle converter

    Science.gov (United States)

    Podzharenko, Volodymyr A.; Kulakov, Pavlo I.

    2001-06-01

    The photo-electric angle transmitter of rotation is offered, at which the output voltage is linear function of entering magnitude. In a transmitter the linear phototransducer is used on the basis of pair photo diode -- operating amplifier, which output voltage is linear function of the area of an illuminated photosensitive stratum, and modulator of a light stream of the special shape, which ensures a linear dependence of this area from an angle of rotation. The transmitter has good frequent properties and can be used for dynamic measurements of an angular velocity and angle of rotation, in systems of exact drives and systems of autocontrol.

  6. [Secondary hypertension].

    Science.gov (United States)

    Yoshida, Yuichi; Shibata, Hirotaka

    2015-11-01

    Hypertension is a common disease and a crucial predisposing factor of cardiovascular diseases. Approximately 10% of hypertensive patients are secondary hypertension, a pathogenetic factor of which can be identified. Secondary hypertension consists of endocrine, renal, and other diseases. Primary aldosteronism, Cushing's syndrome, pheochromocytoma, hyperthyroidism, and hypothyroidism result in endocrine hypertension. Renal parenchymal hypertension and renovascular hypertension result in renal hypertension. Other diseases such as obstructive sleep apnea syndrome are also very prevalent in secondary hypertension. It is very crucial to find and treat secondary hypertension at earlier stages since most secondary hypertension is curable or can be dramatically improved by specific treatment. One should keep in mind that screening of secondary hypertension should be done at least once in a daily clinical practice. PMID:26619670

  7. Phase angle measurement techniques

    Energy Technology Data Exchange (ETDEWEB)

    Madge, R.; Fischer, D.

    1996-01-01

    Real-time measure of the power transfer across a transmission line was discussed. Phase angle measurement techniques, algorithms and applications relevant to power utilities were assessed. Phase-based applications compute the voltage angle difference between two stations, thereby allowing for power transfer calculations and power system control applications. A list of phase angle measurement applications was provided. It includes frequency measurement, state estimation, adaptive relaying, power system control, system restoration, real power flow monitoring and stability assessment, reactive power requirements monitoring, HVDC modulation, subsynchronous resonance, sequence of event recording, and loss reduction and fault location. The optimum timing requirement was determined for each application. Among the timing systems available today, the Global Positioning System (GPS), supported by powerful computers and other custom hardware, is the only tool that can provide the accuracy and coverage needed by today`s power system applications. Commercially available equipment for phase angle measurements was also reviewed. 30 refs., 32 tabs., 5 figs.

  8. Peritonitis - secondary

    Science.gov (United States)

    ... of the abdominal organs. It is called the peritoneum. Secondary means it is due to another condition. ... has several major causes. Bacteria may enter the peritoneum through a hole (perforation) in the gastrointestinal tract. ...

  9. The quadriceps angle

    DEFF Research Database (Denmark)

    Miles, James Edward; Frederiksen, Jane V.; Jensen, Bente Rona;

    2012-01-01

    : Pelvic limbs from red foxes (Vulpes vulpes). METHODS: Q angles were measured on hip dysplasia (HD) and whole limb (WL) view radiographs of each limb between the acetabular rim, mid-point (Q1: patellar center, Q2: femoral trochlea), and tibial tuberosity. Errors of 0.5-2.0 mm at measurement landmarks...

  10. Yaw Angle Demonstration

    Science.gov (United States)

    1994-01-01

    The Large Angle Magnetic Suspension Test Fixture (LAMSTF) is a 5 degree-of -freedom repulsive force magnetic suspension system designed to study the control of objects over large magnetic gaps. A digital control algorithm uses 6 sets of laser-sheet sensors and 5 control coils to position a cylinder 3' above the plane of electromagnetics

  11. The lateral angle revisited

    DEFF Research Database (Denmark)

    Morgan, Jeannie; Lynnerup, Niels; Hoppa, R.D.

    2013-01-01

    measurements taken from computed tomography (CT) scans. Previous reports have observed that the lateral angle size in females is significantly larger than in males. The method was applied to an independent series of 77 postmortem CT scans (42 males, 35 females) to validate its accuracy and reliability. The...

  12. Large Piwinski angle

    CERN Document Server

    Abelleira, J L; Bhat, C; Cornelis, K; De Maria, R; Fartoukh, S; Giachino, R; Holzer, E B; Lamont, M; Mastoridis, T; Macpherson, A; Papotti, G; Pieloni, T; Roncarolo, F; Roy, G; Salvachua, B; Valuch, D; Zimmermann, F; Ohmi, K

    2012-01-01

    Two high brightness bunches per beam were collided at injection energy with varying spectrometer strength in IP8 so that the corresponding Piwinski angle changed from about 1.2–1.3 to 0.2. One of the two bunches colliding in IP8 also collided in IPs 1 and 5, increasing its tune spread. A Piwinski angle of 1.2 is the biggest value ever achieved in a hadron collider. The goal of this experiemnt had been to investigate the influence of this parameter on the luminosity lifetime, beam lifetime and emittance growth rate. Due to technical problems and unavailability of luminosity signals from CMS this goal was only partially accomplished.

  13. Why are angles misperceived?

    OpenAIRE

    Nundy, Surajit; Lotto, Beau; Coppola, David; Shimpi, Amita; Purves, Dale

    2000-01-01

    Although it has long been apparent that observers tend to overestimate the magnitude of acute angles and underestimate obtuse ones, there is no consensus about why such distortions are seen. Geometrical modeling combined with psychophysical testing of human subjects indicates that these misperceptions are the result of an empirical strategy that resolves the inherent ambiguity of angular stimuli by generating percepts of the past significance of the stimulus rather than the geometry of its re...

  14. Angle states in quantum mechanics

    Science.gov (United States)

    de la Torre, A. C.; Iguain, J. L.

    1998-12-01

    Angle states and angle operators are defined for a system with arbitrary angular momentum. They provide a reasonable formalization of the concept of angle provided that we accept that the angular orientation is quantized. The angle operator is the generator of boosts in angular momentum and is, almost everywhere, linearly related to the logarithm of the shift operator. Angle states for fermions and bosons behave differently under parity transformation.

  15. Critical angle laser refractometer

    International Nuclear Information System (INIS)

    A simple laser refractometer based on the detection of the critical angle for liquids is presented. The calibrated refractometer presents up to 0.000 11 of uncertainty when the refractive index is in the range between 1.300 00 and 1.340 00. The experimental setup is easy to construct and the material needed is available at most optics laboratories. The calibration method is simple and can be used in other devices. The refractive index measurements in aqueous solutions of sodium chloride were carried out to test the device and a linear dependence between the refractive index and the salt concentration was found

  16. Variable angle correlation spectroscopy

    International Nuclear Information System (INIS)

    In this dissertation, a novel nuclear magnetic resonance (NMR) technique, variable angle correlation spectroscopy (VACSY) is described and demonstrated with 13C 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

  17. Variable angle correlation spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Y K [Univ. of California, Berkeley, CA (United States)

    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.

  18. Angle performance on optima MDxt

    International Nuclear Information System (INIS)

    Angle control on medium current implanters is important due to the high angle-sensitivity of typical medium current implants, such as halo implants. On the Optima MDxt, beam-to-wafer angles are controlled in both the horizontal and vertical directions. In the horizontal direction, the beam angle is measured through six narrow slits, and any angle adjustment is made by electrostatically steering the beam, while cross-wafer beam parallelism is adjusted by changing the focus of the electrostatic parallelizing lens (P-lens). In the vertical direction, the beam angle is measured through a high aspect ratio mask, and any angle adjustment is made by slightly tilting the wafer platen prior to implant. A variety of tests were run to measure the accuracy and repeatability of Optima MDxt’s angle control. SIMS profiles of a high energy, channeling sensitive condition show both the cross-wafer angle uniformity, along with the small-angle resolution of the system. Angle repeatability was quantified by running a channeling sensitive implant as a regular monitor over a seven month period and measuring the sheet resistance-to-angle sensitivity. Even though crystal cut error was not controlled for in this case, when attributing all Rs variation to angle changes, the overall angle repeatability was measured as 0.16° (1σ). A separate angle repeatability test involved running a series of V-curves tests over a four month period using low crystal cut wafers selected from the same boule. The results of this test showed the angle repeatability to be <0.1° (1σ).

  19. Heterodyne Interferometer Angle Metrology

    Science.gov (United States)

    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.

  20. Small angle neutron scattering

    Directory of Open Access Journals (Sweden)

    Cousin Fabrice

    2015-01-01

    Full Text Available 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

  1. Small angle neutron scattering

    International Nuclear Information System (INIS)

    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 about 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 nano-metric 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 information 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 (2. 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

  2. Spinning angle optical calibration apparatus

    Science.gov (United States)

    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.

  3. Calculations of the Wigner angle

    International Nuclear Information System (INIS)

    Two new methods to determine Wigner's angle in special relativity are presented. The first one consists in calculating the angle between the compositions u-bar x ν-bar and ν-bar x u-bar of the two non-collinear velocities u-bar and ν-bar. In another method we introduce a generalization in the complex plane of Einstein's addition law of parallel velocities. (author)

  4. Dynamic contact angle of water-based titanium oxide nanofluid

    OpenAIRE

    Radiom, Milad; Yang, Chun; Chan, Weng Kong

    2013-01-01

    Abstract This paper presents an investigation into spreading dynamics and dynamic contact angle of TiO2-deionized water nanofluids. Two mechanisms of energy dissipation, (1) contact line friction and (2) wedge film viscosity, govern the dynamics of contact line motion. The primary stage of spreading has the contact line friction as the dominant dissipative mechanism. At the secondary stage of spreading, the wedge film viscosity is the dominant dissipative mechanism. A theoretical model based ...

  5. Frequency scaling for angle gathers

    KAUST Repository

    Zuberi, M. A H

    2014-01-01

    Angle gathers provide an extra dimension to analyze the velocity after migration. Space-shift and time shift-imaging conditions are two methods used to obtain angle gathers, but both are reasonably expensive. By scaling the time-lag axis of the time-shifted images, the computational cost of the time shift imaging condition can be considerably reduced. In imaging and more so Full waveform inversion, frequencydomain Helmholtz solvers are used more often to solve for the wavefields than conventional time domain extrapolators. In such cases, we do not need to extend the image, instead we scale the frequency axis of the frequency domain image to obtain the angle gathers more efficiently. Application on synthetic data demonstrate such features.

  6. Discovering the Inscribed Angle Theorem

    Science.gov (United States)

    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,…

  7. Contactless angle detection using permalloy

    NARCIS (Netherlands)

    Eijkel, Kees J.; Rijk, Rolf

    1988-01-01

    An overview is given of measurements on angle detectors. The detectors consist of a pair of planar-Hall elements opposite to a rotatable magnet. The measurements are performed on a number of planar-Hall elements of different shape and size, and show good agreement with a previously described theoret

  8. Aspect angle dependence of backscatter intensity of 1-m auroral plasma waves

    International Nuclear Information System (INIS)

    The backscatter intensities of primary and secondary 1-m unstable plasma waves in the auroral E region have been measured as a function of magnetic aspect angle (α) for electric field values between 25 and 30 mV/m. The variation of the absorption A, measured in decibels, is of the form A = -IaCo cos2 α/(1 + Co cos2 α). The best fits to the observed attenuation yield parameter values of (Ia, Co) = (49.6, 530) and (48.8, 900) for primary and secondary waves, respectively. The backscatter intensity from primary waves has the same aspect angle dependence as the mean Doppler velocity aspect angle-dependence observed in previous auroral radar data sets (Nielsen, 1986). The observations suggest that the radar backscatter cross section of the primary waves maximizes a few kilometers higher in altitude than that of the secondary waves

  9. Multi-angle compound imaging

    DEFF Research Database (Denmark)

    Jespersen, Søren Kragh; Wilhjelm, Jens Erik; Sillesen, Henrik

    1998-01-01

    This paper reports on a scanning technique, denoted multi-angle compound imaging (MACI), using spatial compounding. The MACI method also contains elements of frequency compounding, as the transmit frequency is lowered for the highest beam angles in order to reduce grating lobes. Compared to...... conventional B-mode imaging MACI offers better defined tissue boundaries and lower variance of the speckle pattern, resulting in an image with reduced random variations. Design and implementation of a compound imaging system is described, images of rubber tubes and porcine aorta are shown and effects on...... visualization are discussed. The speckle reduction is analyzed numerically and the results are found to be in excellent agreement with existing theory. An investigation of detectability of low-contrast lesions shows significant improvements compared to conventional imaging. Finally, possibilities for improving...

  10. Wide-angle electron detector

    International Nuclear Information System (INIS)

    The design, functioning, and main calibration, characteristics of a wide-angle detector, capable of recording electrons with energies >= 8 keV and insensitive to u.v. solar radiation are described. A description of the sensor (electron trap) and its electronics in the analog (DEGAFOC) and counting (DEGAFOI) modes is given. Examples of telemetry recordings, illustrating the operation of the detector are included. (Auth.)

  11. Ocular Biometry in Angle Closure

    Directory of Open Access Journals (Sweden)

    Mohammad Reza Razeghinejad

    2013-01-01

    Full Text Available Purpose: To compare ocular biometric parameters in primary angle closure suspects (PACS, primary angle closure glaucoma (PACG and acute primary angle closure (APAC. Methods: This cross-sectional study was performed on 113 patients including 33 cases of PACS, 45 patients with PACG and 35 subjects with APAC. Central corneal thickness (CCT, axial length (AL, anterior chamber depth (ACD and lens thickness (LT were measured with an ultrasonic biometer. Lens-axial length factor (LAF, relative lens position, corrected ACD (CACD and corrected lens position were calculated. The parameters were measured bilaterally but only data from the right eyes were compared. In the APAC group, biometric parameters were also compared between affected and unaffected fellow eyes. Logistic regression analysis was performed to identify risk factors. Results: No statistically significant difference was observed in biometric parameters between PACS and PACG eyes, or between affected and fellow eyes in the APAC group (P>0.05 for all comparisons. However, eyes with APAC had thicker cornea (P=0.001, thicker lens (P<0.0001, shallower ACD (P=0.009, shallower CACD (P=0.003 and larger LAF (P<0.0001. Based on ROC curve analysis, lower ACD, and larger LT, LAF and CCT values were associated with APAC. In the APAC group, LAF (P<0.0001 and CCT (P=0.001 were significant risk factors. Conclusion: This study revealed no significant difference in biometric characteristics in eyes with PACS and PACG. However, larger LAF and CCT were predictive of APAC.

  12. Small angle scattering and polymers

    International Nuclear Information System (INIS)

    The determination of polymer structure is a problem of interest for both statistical physics and industrial applications. The average polymer structure is defined. Then, it is shown why small angle scattering, associated with isotopic substitution, is very well suited to the measurement of the chain conformation. The corresponding example is the old, but pedagogic, measurement of the chain form factor in the polymer melt. The powerful contrast variation method is illustrated by a recent determination of the concentration profile of a polymer interface. (author) 12 figs., 48 refs

  13. Opening Angles of Collapsar Jets

    OpenAIRE

    Mizuta, Akira; Ioka, Kunihito

    2013-01-01

    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 $\\theta_j \\sim 1/5 \\Gamma_{0}$, and infer the initial Lorentz factor of the jet at the central engine, $\\Gamma_0$, is a few for existing observations of $\\theta_j$. The jet keeps the Lorentz factor low inside the star by converging cylindricall...

  14. Small angle scattering and polymers

    Energy Technology Data Exchange (ETDEWEB)

    Cotton, J.P. [Laboratoire Leon Brillouin (LLB) - Centre d`Etudes de Saclay, 91 - Gif-sur-Yvette (France)

    1996-12-31

    The determination of polymer structure is a problem of interest for both statistical physics and industrial applications. The average polymer structure is defined. Then, it is shown why small angle scattering, associated with isotopic substitution, is very well suited to the measurement of the chain conformation. The corresponding example is the old, but pedagogic, measurement of the chain form factor in the polymer melt. The powerful contrast variation method is illustrated by a recent determination of the concentration profile of a polymer interface. (author) 12 figs., 48 refs.

  15. Predicting dihedral angle probability distributions for protein coil residues from primary sequence using neural networks

    DEFF Research Database (Denmark)

    Helles, Glennie; Fonseca, Rasmus

    2009-01-01

    residue in the input-window. The trained neural network shows a significant improvement (4-68%) in predicting the most probable bin (covering a 30°×30° area of the dihedral angle space) for all amino acids in the data set compared to first order statistics. An accuracy comparable to that of secondary...... local context dependent dihedral angle propensities in coil-regions. This predicted distribution can potentially improve tertiary structure prediction methods that are based on sampling the backbone dihedral angles of individual amino acids. The predicted distribution may also help predict local...

  16. Small-angle neutron-scattering experiments

    International Nuclear Information System (INIS)

    A brief introduction to small-angle scattering (SAS) is given. Initial results obtained using the AERE small-angle diffractometer are presented for four materials of interest: doped uranium dioxide, nitrided steel, graphite and alumina. (U.K.)

  17. The Complex Angle in Normed Spaces

    International Nuclear Information System (INIS)

    We consider a generalized angle in complex normed vector spaces. Its definition corresponds to the definition of the well known Euclidean angle in real inner product spaces. Not surprisingly it yields complex values as 'angles'. This 'angle' has some simple properties, which are known from the usual angle in real inner product spaces. But to do ordinary Euclidean geometry real angles are necessary. We show that even in a complex normed space there are many pure real valued 'angles'. The situation improves yet in inner product spaces. There we can use the known theory of orthogonal systems to find many pairs of vectors with real angles, and to do geometry which is based on the Greeks 2000 years ago

  18. An Angle Criterion for Riesz Bases

    DEFF Research Database (Denmark)

    Lindner, Alexander M; Bittner, B.

    We present a characterization of Riesz bases in terms ofthe angles between certain finite dimensional subspaces. Correlationsbetween the bounds of the Riesz basis and the size of the angles arederived....

  19. Raman spectroscopy measurement of bilayer graphene's twist angle to boron nitride

    International Nuclear Information System (INIS)

    When graphene is placed on hexagonal boron nitride with a twist angle, new properties develop due to the resulting moiré superlattice. Here, we report a method using Raman spectroscopy to make rapid, non-destructive measurements of the twist angle between bilayer graphene and hexagonal boron nitride. The lattice orientation is determined by using flakes with both bilayer and monolayer regions, and using the known Raman signature for the monolayer to measure the twist angle of the entire flake. The widths of the second order Raman peaks are found to vary linearly in the superlattice period and are used to determine the twist angle. The results are confirmed by using transport measurements to infer the superlattice period by the charge density required to reach the secondary resistance peaks. Small twist angles are also found to produce a significant modification of the first order Raman G band peak

  20. The qualitative criterion of transient angle stability

    OpenAIRE

    Lyu, R; Xue, Y.; Xue, F; Wu, Qiuwei; Yang, Guangya; Zhou, H; Ju, P.

    2015-01-01

    In almost all the literatures, the qualitative assessment of transient angle stability extracts the angle information of generators based on the swing curve. As the angle (or angle difference) of concern and the threshold value rely strongly on the engineering experience, the validity and robust of these criterions are weak. Based on the stability mechanism from the extended equal area criterion (EEAC) theory and combining with abundant simulations of real system, this paper analyzes the crit...

  1. Explicit angle structures for veering triangulations

    CERN Document Server

    Futer, David

    2010-01-01

    Agol recently introduced the notion of a veering triangulation, and showed that such triangulations naturally arise as layered triangulations of fibered hyperbolic 3-manifolds. We prove, by a constructive argument, that every veering triangulation admits positive angle structures, recovering a result of Hodgson, Rubinstein, Segerman, and Tillmann. Our construction leads to explicit lower bounds on the smallest angle in this positive angle structure, and to information about angled holonomy of the boundary tori.

  2. [Late postcontusion secondary glaucoma].

    Science.gov (United States)

    Chiseliţă, D; Vancea, P; Filiman, O; Brănişteanu, D; Bredetean, M; Poiata, I

    1995-01-01

    The investigation of 33 patients with late postcontusional glaucoma subjected to surgery and followed up for 25 +/- 8.24 months has revealed: the interval accident-surgery is shorter in the close-angle combined forms; the essential mechanisms responsible for glaucoma occurrence are: the alteration of trabecular meshwork (for open-angle glaucoma) and pupillary block (for close angle glaucoma); simple cases required antiglaucoma surgery (trabeculectomy, peripheral iridectomy) and the mixed ones required combined (trabeculectomy, lens extraction, lens implant) or sequential surgeries (antiglaucoma surgery, vitrectomy etc); the glaucomatous process was stopped in 83.4% of the open-angle glaucoma cases and progressed in 23.5% of the close-angle glaucoma cases; the functional improvements post antiglaucoma surgery combined with removal of opacities are lessened by the higher frequency of severe per- and post-operative complication. PMID:7654676

  3. 30 CFR 56.19037 - Fleet angles.

    Science.gov (United States)

    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...

  4. 30 CFR 57.19037 - Fleet angles.

    Science.gov (United States)

    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...

  5. SECONDARY BRAIN INJURY

    OpenAIRE

    Ida Ayu Basmatika

    2013-01-01

    Secondary brain injury is a condision that occurs at some times after the primary impact and can be largely prevented and treated. Most brain injury ends with deadly consequences which is caused by secondary damage to the brain. Traumatic brain injured still represents the leading cause of morbidity and mortality in individuals under the age of 45 years in the world. The classification of secondary brain injured is divided into extracranial and intracranial causes. The cause of extracranial s...

  6. Secondary Surveillance Radar Antenna

    OpenAIRE

    Schejbal, Vladimír; Bezoušek, Pavel; Pidanič, Jan; Chyba, Milan

    2013-01-01

    This paper deals with a secondary surveillance radar (SSR) array antenna, which is intended for a system combining the secondary surveillance radar antenna and the primary surveillance radar antenna. It describes the patch array elements and the synthesis for the secondary surveillance radar array, considering both elevation and azimuth patterns for sum, difference, and sidelobe-suppression beams, and suspended stripline couplers. The utilization of multilayer techniques allows the connection...

  7. Optimized design and research of secondary microprism for dense array concentrating photovoltaic module

    Science.gov (United States)

    Yang, Guanghui; Chen, Bingzhen; Liu, Youqiang; Guo, Limin; Yao, Shun; Wang, Zhiyong

    2015-10-01

    As the critical component of concentrating photovoltaic module, secondary concentrators can be effective in increasing the acceptance angle and incident light, as well as improving the energy uniformity of focal spots. This paper presents a design of transmission-type secondary microprism for dense array concentrating photovoltaic module. The 3-D model of this design is established by Solidworks and important parameters such as inclination angle and component height are optimized using Zemax. According to the design and simulation results, several secondary microprisms with different parameters are fabricated and tested in combination with Fresnel lens and multi-junction solar cell. The sun-simulator IV test results show that the combination has the highest output power when secondary microprism height is 5mm and top facet side length is 7mm. Compared with the case without secondary microprism, the output power can improve 11% after the employment of secondary microprisms, indicating the indispensability of secondary microprisms in concentrating photovoltaic module.

  8. The Q-angle and sport

    DEFF Research Database (Denmark)

    Hahn, Thomas; Foldspang, Anders

    1997-01-01

    Quadriceps muscle contraction tends to straighten the Q angle. We expected that sports comprising a high amount of quadriceps training could be associated with low Q angles. The aim of the present study was to estimate the Q angle in athletes and to investigate its potential associations with par......Quadriceps muscle contraction tends to straighten the Q angle. We expected that sports comprising a high amount of quadriceps training could be associated with low Q angles. The aim of the present study was to estimate the Q angle in athletes and to investigate its potential associations...... with participation in sport. Three hundred and thirty-nine athletes had their Q angle measured. The mean of right-side Q angles was higher than left side, and the mean Q angle was higher in women than in men. The Q angle was positively associated with years of jogging, and negatively with years of soccer, swimming...... and sports participation at all. It is concluded that the use of Q angle measurements is questionable....

  9. Evaluation of blotchy pigments in the anterior chamber angle as a sign of angle closure

    Directory of Open Access Journals (Sweden)

    Harsha L Rao

    2012-01-01

    Full Text Available Background: Blotchy pigments in the anterior chamber (AC angle are considered diagnostic of primary angle closure (PAC. But there are no reports either on the prevalence of blotchy pigments in AC angles or the validity of this sign. Aims: To determine the prevalence of blotchy pigments in AC angles and to evaluate their relationship with glaucomatous optic neuropathy (GON in eyes with occludable angles. Setting and Design: Cross-sectional, comparative study. Materials and Methods: Gonioscopy was performed in 1001 eyes of 526 subjects (245 eyes of 148 consecutive, occludable angle subjects and 756 eyes of 378 non-consecutive, open angle subjects, above 35 years of age. Quadrant-wise location of blotchy pigments was documented. Statistical Analysis: Odds of blotchy pigments in occludable angles against that in open angles were evaluated. Relationship of GON with blotchy pigments in occludable angle eyes was evaluated using a multivariate model. Results: Prevalence of blotchy pigments in occludable angles was 28.6% (95% CI, 22.9-34.3 and in open angles was 4.7% (95% CI, 3.2-6.3. Blotchy pigments were more frequently seen in inferior (16% and superior quadrants (15% of occludable angles, and inferior quadrant of open angles (4%. Odds of superior quadrant blotchy pigments in occludable angles were 33 times that in open angles. GON was seen in 107 occludable angle eyes. Blotchy pigments were not significantly associated with GON (odds ratio = 0.5; P = 0.1. Conclusions: Blotchy pigments were seen in 28.6% of occludable angle eyes and 4.7% of open angles eyes. Presence of blotchy pigments in the superior quadrant is more common in occludable angles. Presence of GON in occludable angle eyes was not associated with blotchy pigments.

  10. Meningioma of the Posterior Skull Base

    OpenAIRE

    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.

  11. Intraoperative monitoring during surgery for acoustic neuroma: benefits of an extratympanic intrameatal electrode

    OpenAIRE

    Mullatti, N; Coakham, H; Maw, A; Butler, S; Morgan, M.

    1999-01-01

    OBJECTIVES—To assess the utility of an extratympanic intrameatal electrode for intraoperative monitoring during acoustic neuroma and other cerebellopontine angle tumour surgery and to define the neurophysiological and surgical factors which influence hearing preservation.
METHODS—Twenty two patients, 18 with acoustic neuromas and four with other cerebellopontine angle tumours, underwent intraoperative monitoring during tumour excision. The extratympanic intrameatal electrode...

  12. Secondary electron emission from accelerator materials

    International Nuclear Information System (INIS)

    Motivations gained from this paper are: (1) Suppress electron emission from high rf surface field components, e.g., SPEAR storage ring cavity tuners (1973), (2) Find a coating for superconducting Nb oxidation prevention (1980), (3) Develop a simple method for TiN-coating of LER Al alloy beam chambers (1998), and (4) Measure yields as a function of primary electron incidence angle, for simulating of the electron cloud effect (1999). Conclusions drawn from data: (1) Most electron-generated secondaries will have low energy (∼4 eV) and 2O and HCs works (but probably leaves carbon in technical vacuum), and (4) The yield increase with primary electron beam angle is about that expected

  13. Teaching secondary mathematics

    CERN Document Server

    Rock, David

    2013-01-01

    Solidly grounded in up-to-date research, theory and technology,?Teaching Secondary Mathematics?is a practical, student-friendly, and popular text for secondary mathematics methods courses. It provides clear and useful approaches for mathematics teachers, and shows how concepts typically found in a secondary mathematics curriculum can be taught in a positive and encouraging way. The thoroughly revised fourth edition combines this pragmatic approach with truly innovative and integrated technology content throughout. Synthesized content between the book and comprehensive companion websi

  14. Caustic graphene plasmons with Kelvin angle

    CERN Document Server

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

    2015-01-01

    A century-long argument made by Lord Kelvin that all swimming objects have an effective Mach number of 3, corresponding to the Kelvin angle of 19.5 degree for ship waves, has been recently challenged with the conclusion that the Kelvin angle should gradually transit to the Mach angle as the ship 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 semi-angle of the wave pattern approaches the Mach angle. Our study introduces caustic wave theory to the field of graphene plasmonics, and reveals a novel physical picture of graphene plasmon excitation during electron energy-loss spectroscopy measurement.

  15. OPTIMIZATION OF TILT ANGLE FOR PHOTOVOLTAIC ARRAY

    OpenAIRE

    Ashok Kumar; N.S.Thakur,; Rahul Makade,; Maneesh Kumar Shivhar

    2011-01-01

    The performance of a solar radiation conversion system is affected by its tilt angle with the horizontal plane, thus photovoltaic array need to be tilted at the correct angle to maximize the performance of the System, This paper deals with the determination of optimum tilt angle for solar PV array in order to maximize incident solar irradiance. The model starts by calculating the monthly averaged daily solar irradiation components (direct, diffuse, ground- eflected) absorbed by the solar PV a...

  16. Behavior of Tilted Angle Shear Connectors.

    Directory of Open Access Journals (Sweden)

    Koosha Khorramian

    Full Text Available 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.

  17. Pitch angle of galactic spiral arms

    International Nuclear Information System (INIS)

    One of the key parameters that characterizes spiral arms in disk galaxies is a pitch angle that measures the inclination of a spiral arm to the direction of galactic rotation. The pitch angle differs from galaxy to galaxy, which suggests that the rotation law of galactic disks determines it. In order to investigate the relation between the pitch angle of spiral arms and the shear rate of galactic differential rotation, we perform local N-body simulations of pure stellar disks. We find that the pitch angle increases with the epicycle frequency and decreases with the shear rate and obtain the fitting formula. This dependence is explained by the swing amplification mechanism.

  18. Best Angle to Orient Two Intersecting Lines

    Energy Technology Data Exchange (ETDEWEB)

    Awwal, A S; Ferguson, S W; Shull, P B

    2006-07-25

    Fiducials in the form of intersecting straight lines are used to align the target in the final target chamber of the National Ignition Facility of Lawrence Livermore National Laboratory. One of the techniques used to locate these lines is the Hough transform. When two lines intersect at a 90 degree angle, it is tempting to orient the lines to horizontal and vertical directions. There are other possible angles at which the lines may be oriented. One question that arises while designing the fiducials is whether there is a preferred angle or range of angles that leads to higher accuracy. This work attempts to answer this question through detailed computer simulation.

  19. Lateral angle and cranial base sexual dimorphism

    DEFF Research Database (Denmark)

    Duquesnel Mana, Mathilde; Adalian, Pascal; Lynnerup, Niels

    2016-01-01

    , to examine sexual dimorphism in the relationship between the lateral angle and cranial base shape. The lateral angle method was tested using a forensic sample of 102 CT scans of the head with known sex. We measured the angle using two methods: measurements directly on the CT slide, the method usually...... major overlap between the female and male shapes. In the light of the observed results, we confirm the lack of accuracy reported when using the lateral angle method to determine sex and we hypothesise that it may be explained by a lack of sexual dimorphism of the cranial base in terms of shape....

  20. The qualitative criterion of transient angle stability

    DEFF Research Database (Denmark)

    Lyu, R.; Xue, Y.; Xue, F.;

    2015-01-01

    In almost all the literatures, the qualitative assessment of transient angle stability extracts the angle information of generators based on the swing curve. As the angle (or angle difference) of concern and the threshold value rely strongly on the engineering experience, the validity and robust of...... these criterions are weak. Based on the stability mechanism from the extended equal area criterion (EEAC) theory and combining with abundant simulations of real system, this paper analyzes the criterions in most literatures and finds that the results could be too conservative or too optimistic. It is...

  1. Secondary extinctions of biodiversity.

    Science.gov (United States)

    Brodie, Jedediah F; Aslan, Clare E; Rogers, Haldre S; Redford, Kent H; Maron, John L; Bronstein, Judith L; Groves, Craig R

    2014-12-01

    Extinctions beget further extinctions when species lose obligate mutualists, predators, prey, or hosts. Here, we develop a conceptual model of species and community attributes affecting secondary extinction likelihood, incorporating mechanisms that buffer organisms against partner loss. Specialized interactors, including 'cryptic specialists' with diverse but nonredundant partner assemblages, incur elevated risk. Risk is also higher for species that cannot either evolve new traits following partner loss or obtain novel partners in communities reorganizing under changing environmental conditions. Partner loss occurs alongside other anthropogenic impacts; multiple stressors can circumvent ecological buffers, enhancing secondary extinction risk. Stressors can also offset each other, reducing secondary extinction risk, a hitherto unappreciated phenomenon. This synthesis suggests improved conservation planning tactics and critical directions for research on secondary extinctions. PMID:25445878

  2. Primary and Secondary Qualities

    Czech Academy of Sciences Publication Activity Database

    Hill, James

    New York: Continuum, 2010 - ( Savonius -Wroth, S.; Schuurman, P.; Walmsley, J.), s. 199-201 ISBN 9780826428110 Institutional research plan: CEZ:AV0Z90090514 Keywords : primary and secondary qualities * Locke * corpuscularianism Subject RIV: AA - Philosophy ; Religion

  3. Secondary Nocturnal Enuresis

    Science.gov (United States)

    ... NKF Newsroom Contact Us You are here Home » Secondary Nocturnal Enuresis Some children have always wet the ... is important to instill confidence and enhance compliance. Motivation is an important factor for success. Many of ...

  4. SECONDARY BRAIN INJURY

    Directory of Open Access Journals (Sweden)

    Ida Ayu Basmatika

    2013-03-01

    Full Text Available Secondary brain injury is a condision that occurs at some times after the primary impact and can be largely prevented and treated. Most brain injury ends with deadly consequences which is caused by secondary damage to the brain. Traumatic brain injured still represents the leading cause of morbidity and mortality in individuals under the age of 45 years in the world. The classification of secondary brain injured is divided into extracranial and intracranial causes. The cause of extracranial such as hipoxia, hypotensi, hyponatremia, hypertermia, hypoglycemia or hyperglycemia. The cause of intracranial such as extradural, subdural, intraserebral, intraventrikular, dan subarachnoid hemorrhage. Beside that secondary injury can also be caused by edema and infection. Post-traumatic cerebral injured is characterized by direct tissue damage, impaired regulation of cerebral blood flow (cerebral blood flow / CBF, and disruption of metabolism. Manifestations of secondary brain injured include increased intracranial pressure, ischemic brain damage, cerebral hypoxia and hypercarbi, as well as disruption of cerebral autoregulation. The first priority is to stabilize the patient's cervical spine injury, relieve and maintain airway, ensure adequate ventilation (breathing, and making venous access for fluid resuscitation pathways (circulation and assessing the level of awareness and disability. This steps is crucial in patients with head injured to prevent hypoxia and hypotension, which is the main cause of secondary brain injury.

  5. The Research of Secondary Arc Spectrum Characteristics on UHV

    Directory of Open Access Journals (Sweden)

    Yunwei Zhao

    2012-10-01

    Full Text Available On UHV power transmission lines, when single-phase ground fault happen, it will appear secondary arc on lines, the existence of secondary arc impact on the stable operation of system. The effectiveness of single-pole autoreclosure (SPAR in maintaining power system stability is largely determined by the speed with which secondary arc extinction, and hence autoreclosure, can be achieved. The paper adopts total harmonic distortion (THD to judge the status of arc. First, the simulation model of secondary arc is established by ATP software. Then, faulted phase voltage and secondary arc are simulated in different close angle. Last, spectrum characteristics and harmonic content of faulted phase voltage and current are analyzed in different close angle, at the same time, THD of non-faulted phase is also analyzed by Fourier algorithm. Through the fault phase voltage and current simulation and Fourier analysis, which comes to the conclusion that at the peak in the power supply voltage secondary arc is the most difficult to extinguish and the harm to insulation is the greatest.

  6. Small solid angle device setup and application

    International Nuclear Information System (INIS)

    To quantize the weight of Uranium-plate accurately, the small solid angle device was redesigned. To fit the requirement of homogeneity check, the sliding base was introduced in the design. This paper presents the detailed application of small solid angle device setup and quantization of Uranium-plate and homogeneity check. (authors)

  7. Constructing euclidean simplex with prescribed dihedral angles

    International Nuclear Information System (INIS)

    Given 1/2n (n + 1) dihedral angles, what is the condition under which there exists an n-dimensional simplex with the prescribed dihedral angles? A complete solution for this problem is given with application demonstrated. (author). 3 refs

  8. Distribution of angles in hyperbolic lattices

    DEFF Research Database (Denmark)

    Risager, Morten Skarsholm; Truelsen, Jimi Lee

    2010-01-01

    We prove an effective equidistribution result about angles in a hyperbolic lattice. We use this to generalize a result from the study by Boca.......We prove an effective equidistribution result about angles in a hyperbolic lattice. We use this to generalize a result from the study by Boca....

  9. Distribution of Angles in Hyperbolic Lattices

    DEFF Research Database (Denmark)

    S. Risager, Morten; L. Truelsen, Jimi

    2008-01-01

    We prove an effective equidistribution result about angles in a hyperbolic lattice. We use this to generalize a result due to F. P. Boca.......We prove an effective equidistribution result about angles in a hyperbolic lattice. We use this to generalize a result due to F. P. Boca....

  10. A lattice determination of gA and left angle x right angle from overlap fermions

    International Nuclear Information System (INIS)

    We present results for the nucleon's axial charge gA and the first moment left angle x right angle of the unpolarized parton distribution function from a simulation of quenched overlap fermions. (orig.)

  11. Apparent Contact Angle and Contact Angle Hysteresis on Liquid Infused Surfaces

    OpenAIRE

    Semprebon, Ciro; McHale, Glen; Kusumaatmaja, Halim

    2016-01-01

    We theoretically investigate the apparent contact angle and contact angle hysteresis of a droplet placed on a liquid infused surface. We show that the apparent contact angle is not uniquely defined by material parameters, but also has a strong dependence on the relative size between the droplet and its surrounding wetting ridge formed by the infusing liquid. We derive a closed form expression for the contact angle in the limit of vanishing wetting ridge, and compute the correction for small b...

  12. High-angle diffraction of a Gaussian beam by the grating with embedded phase singularity

    CERN Document Server

    Bekshaev, A; Vasnetsov, M

    2009-01-01

    Spatial characteristics of the optical-vortex (OV) beams created during the Gaussian beam diffraction by a grating with groove bifurcation are analyzed theoretically and numerically. In contrast to previous works, condition of small-angle diffraction is no longer required and the diffracted beam can be strongly deformed. This causes the intensity profile rotation and the high-order OV decomposition into a set of secondary single-charged OVs. These effects are studied quantitatively and confronted with similar properties of a Laguerre-Gaussian beam that undergoes astigmatic telescopic transformation. In contrast to the latter case, the secondary OVs do not lie on a single straight line within the beam cross section, and morphology parameters of the individual secondary OVs carried by the same beam are, in general, different. Conditions for maximum relative separation of the secondary OVs with respect to the beam transverse size are specified. The results can be used for practical generation of OV beams and OV ...

  13. Goniometry of elbow carrying angle: a comparative clinical study on sexual dimorphism in young males and females

    Directory of Open Access Journals (Sweden)

    Wasim Bari

    2015-12-01

    Conclusions: Carrying angle is greater in females may be because exhibits high sexual dimorphism. It may also considered be as a secondary sexual characteristic. Utility of goniometry of carrying angle is observed during orthopaedic reconstruction of elbow disorders after treatment of distal fractures of humerus and evaluation of traumatic injuries at the elbow joint. [Int J Res Med Sci 2015; 3(12.000: 3482-3484

  14. Nonadiabatic Hannay's Angle of Spin One Half in Grassmannian Version and Invariant Angle Coherent States

    OpenAIRE

    Cherbal, Omar; Maamache, Mustapha; Drir, Mahrez

    2003-01-01

    We propose to determinate the nonadiabatic Hannay’s angle of spin one half in a varying external magnetic field, by using an averaged version of the variational principal. We also show how the evolution and this nonadiabatic Hannay’s angle is associated with the evolution of Grassmannian invariant-angle coherent states.

  15. Angular deviation of secondary charge particles in 1014-1016 eV extensive air showers: Constrains on application of hodoscopes

    Directory of Open Access Journals (Sweden)

    D Purmohammad

    2012-12-01

    Full Text Available   Deviation angles of secondary electrons and muons in simulated extensive air showers were studied. The angles have wide distribution, whose width depends on energy cuts imposed on shower particles. In this work, variation of deviation angles with the energy of secondary particles, shower energy, primary direction, and core distance was investigated. The results put limitations on application of hodoscopic devices in cosmic ray and gamma ray observations.

  16. Analysis of factors affecting angle ANB.

    Science.gov (United States)

    Hussels, W; Nanda, R S

    1984-05-01

    Cephalometric analyses based on angular and linear measurements have obvious fallacies, which have been discussed in detail by Moyers and Bookstein. However, the clinical application of such an analysis by the orthodontic profession in treatment planning is widely accepted. Variations of angle ANB are commonly used to determine relative jaw relationships in most of the cephalometric evaluations. Several authors, including points A and B influences angle ANB, as does rotational growth of the upper and lower jaws. In addition, the authors point out that growth in a vertical direction (distance N to B) and an increase of the dental height (distance A to B) may contribute to changes in angle ANB. For a Class I relation (Wits = 0 mm), a mathematical formula has been developed which enables the authors to study the geometric influence of angle ANB caused by the following four effects: (1) rotation of the jaws and/or occlusal plane relative to the anterior cranial base; (2) anteroposterior position of N relative to point B, (3) vertical growth (distance N to B); (4) increase in dental height (distance A to B). It was observed that, contrary to the common belief that an ANB angle of 2 +/- 3.0 degrees is considered normal for a skeletal Class I relation, the calculated values of angle ANB will vary widely with changes in these four controlling factors under the same skeletal Class I conditions (Wits = 0 mm). Therefore, in a case under consideration, angle ANB must be corrected for these geometric effects in order to get a proper perspective of the skeletal discrepancy. This is facilitated by comparing the measured ANB angle with the corresponding ANB angle calculated by a formula for a Class I relationship. The corresponding calculated angle ANB can be taken from the tables which are based upon the formula using the same values for SNB, omega (angle between occlusal plane and anterior cranial base), b (which is distance N to B) and a (dental height measured as perpendicular

  17. Diamond detector time resolution for large angle tracks

    Energy Technology Data Exchange (ETDEWEB)

    Chiodini, G., E-mail: chiodini@le.infn.it [INFN - Sezione di Lecce (Italy); Fiore, G.; Perrino, R. [INFN - Sezione di Lecce (Italy); Pinto, C.; Spagnolo, S. [INFN - Sezione di Lecce (Italy); Dip. di Matematica e Fisica “Ennio De Giorgi”, Uni. del Salento (Italy)

    2015-10-01

    The applications which have stimulated greater interest in diamond sensors are related to detectors close to particle beams, therefore in an environment with high radiation level (beam monitor, luminosity measurement, detection of primary and secondary-interaction vertices). Our aims is to extend the studies performed so far by developing the technical advances needed to prove the competitiveness of this technology in terms of time resolution, with respect to more usual ones, which does not guarantee the required tolerance to a high level of radiation doses. In virtue of these goals, measurements of diamond detector time resolution with tracks incident at different angles are discussed. In particular, preliminary testbeam results obtained with 5 GeV electrons and polycrystalline diamond strip detectors are shown.

  18. Qualitative criterion for atom sputtering angle distributions

    International Nuclear Information System (INIS)

    A model is introduced to explain the shape of atom polar emission angle distributions for monocomponent targets sputtered by normally incident keV - energy ions. Analytical expressions are obtained from the model which make it possible to identify three known kinds of the angle distributions - subcosinus, isotropic and supracosinus, for given ion energies and target-ion pairs. Furthermore the fourth, hybrid false-isotropic distribution is found, which is superposition of supracosinus and subcosinus distributions. The theoretical predictions of the angle distributions shape agree with the numerical modeling for sputtering of carbon and platinum by 0.1-10 keV Ar+ ions

  19. The Driven Pendulum at Any Drive Angle

    CERN Document Server

    VanDalen, G J

    2002-01-01

    The driven inverted pendulum undergoes stable oscillations if the drive amplitude and frequency are large enough. This classroom demonstration is best used in junior or graduate level Classical Mechanics courses. This paper reintroduces the equation of motion of the driven pendulum, generalizing to arbitrary driving angle. The pendulum will oscillate about a stable angle, other than straight down, if the drive amplitude and frequency are large enough for a given drive angle. We will explore what is meant by ``large enough.'' Emphasis is given to parameters associated with a simply made demonstration apparatus.

  20. Compression failure of angle-ply laminates

    OpenAIRE

    Peel, Larry D

    1991-01-01

    The present work deals with modes and mechanisms of failure in compression of angleply laminates. Experimental results were obtained from 42 angle-ply IM7/8551-7a specimens with a lay-up of [ (±9) / (=F9)] 6s where 9, the off-axis angle, ranged from 0° to 90°. 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 inte...

  1. New Management of Angle-closure Glaucoma by Phacoemulsification with Foldable Posterior Chamber Intraocular Lens Implantation

    Institute of Scientific and Technical Information of China (English)

    Jian Ge; Yan Guo; Yizhi Liu; Mingkai Lin; Yehong Zhuo; Bing Chen; Xiuqi Chen

    2000-01-01

    Objective: To investigate the management of angle-closure glaucoma by phacoemulsification with foldable posterior chamber intraocular lens (PC-IOL) implantation. Design: Retrospective, noncontrolled interventional case series.Participants: In 36 eyes with angle-closure glaucoma (ACG), there were 18 eyes with primary acute angle-closure glaucoma (PACG), 14 eyes with primary chronic angle-closure glaucoma (PCCG), 3 eyes with secondary acute angle-closure glaucoma (SACG) and 1 eye with secondary chronic angle-closure glaucoma (SCCG).Intervention: Phacoemulsification with posterior chamber intraocular lens implantation.Main Outcome Measures: Postoperative visual acuity, IOP, axial anterior chamber depth.Results: After a mean postoperative follow-up time of 8.81 ± 7.45 months, intraocular pressure was reduced from a preoperative mean of 23.81 ± 17.84 mmHg to a postoperative mean of 12.54 ± 4. 73 mmHg ( P = 0. 001 ). Mean anterior chamber depth was 1.75 ± 0.48 mm preoperatively and 2.29 ± 0.38 mm postoperatively ( P = 0. 000).Best spectacle-corrected visual acuity in 36 eyes ranged from 0. 01 to 0. 7 (20/200 to 20/30) postoperatively, which was better than preoperative VA ranging from hand movement to 0.4 (20/50) ( P= 0. 000).Conclusion: Phacoemulsification with posterior chamber foldable intraocular lens implantation can be a good alternative in treating angle-closure glaucoma. Eye Science 2000; 16:22 ~ 28.

  2. The reliability of humerothoracic angles during arm elevation depends on the representation of rotations.

    Science.gov (United States)

    López-Pascual, Juan; Cáceres, Magda Liliana; De Rosario, Helios; Page, Álvaro

    2016-02-01

    The reliability of joint rotation measurements is an issue of major interest, especially in clinical applications. The effect of instrumental errors and soft tissue artifacts on the variability of human motion measures is well known, but the influence of the representation of joint motion has not yet been studied. The aim of the study was to compare the within-subject reliability of three rotation formalisms for the calculation of the shoulder elevation joint angles. Five repetitions of humeral elevation in the scapular plane of 27 healthy subjects were recorded using a stereophotogrammetry system. The humerothoracic joint angles were calculated using the YX'Y" and XZ'Y" Euler angle sequences and the attitude vector. A within-subject repeatability study was performed for the three representations. ICC, SEM and CV were the indices used to estimate the error in the calculation of the angle amplitudes and the angular waveforms with each method. Excellent results were obtained in all representations for the main angle (elevation), but there were remarkable differences for axial rotation and plane of elevation. The YX'Y" sequence generally had the poorest reliability in the secondary angles. The XZ'Y' sequence proved to be the most reliable representation of axial rotation, whereas the attitude vector had the highest reliability in the plane of elevation. These results highlight the importance of selecting the method used to describe the joint motion when within-subjects reliability is an important issue of the experiment. This may be of particular importance when the secondary angles of motions are being studied. PMID:26787010

  3. Secondary Dance Instructional Guide.

    Science.gov (United States)

    Montgomery County Public Schools, Rockville, MD. Dept. of Instructional Planning and Development.

    This manual provides guidelines for dance teachers in secondary schools. A brief statement is made on the purpose and philosophy of dance education, and activities and instructional suggestions are presented for various dance forms: (1) group dance--folk/ethnic, square dance, and social dance; (2) aerobic dance; (3) jazz dance; (4) modern dance;…

  4. Suicide among Secondary Students.

    Science.gov (United States)

    Coder, Tamara L.; And Others

    1991-01-01

    Investigated incidence of adolescent suicide in Kansas and assessed prevention guidelines and services dealing with adolescent suicide, and perceived needs of Kansas secondary school counselors in the area of teenage suicide. Findings from 484 school counselors indicated increase in suicide rates with age and need for suicide prevention programing…

  5. Dynamics of secondary forests

    NARCIS (Netherlands)

    Breugel, van M.

    2007-01-01

    The succession of tropical secondary forests on abandoned agricultural fields has been studied since long, most often by comparing stands of different age since abandonment. These so-called chronosequence studies have yielded much insight in general patterns of succession and the constraints and con

  6. Cosmetology. Secondary Curriculum Guide.

    Science.gov (United States)

    Moye, Michael D.; And Others

    This curriculum guide is designed to offer guidelines along with supporting resources and teaching ideas from which the local secondary instructor can extract a cosmetology curriculum that meets local needs. Following an outline of the philosophy and goals underlying state and local vocational education programs in Georgia, the purpose and…

  7. Ducted turbine theory with right angled ducts

    International Nuclear Information System (INIS)

    This paper describes the use of an inviscid approach to model a ducted turbine – also known as a diffuser augmented turbine – and a comparison of results with a particular one-dimensional theory. The aim of the investigation was to gain a better understanding of the relationship between a real duct and the ideal diffuser, which is a concept that is developed in the theory. A range of right angled ducts, which have a rim for a 90° exit angle, were modelled. As a result, the performance of right angled ducts has been characterised in inviscid flow. It was concluded that right angled ducts cannot match the performance of their associated ideal diffuser and that the optimum rotor loading for these turbines varies with the duct dimensions

  8. The solid angle through the vertical rectangle

    Science.gov (United States)

    Schröer, H.

    We want to determine the solid angle through the vertical rectangle. We use the cosine law for sides and the spherical law of sines. The relation to luminous flux (radiant flux or radiant power) is shown.

  9. The solid angle through the isosceles triangle

    Science.gov (United States)

    Schröer, H.

    We want to determine the solid angle through the isosceles triangle. We use the cosine law for sides and the spherical law of sines. The relation to luminous flux(radiant flux or radiant power) is shown.

  10. The solid angle through the inclined rectangle

    Science.gov (United States)

    Schröer, H.

    We want to determine the solid angle through the inclined rectangle. We use the cosine law for sides and the spherical law of sines. The relation to luminous flux(radiant flux or radiant power) is shown.

  11. Optical fibre angle sensor used in MEMS

    International Nuclear Information System (INIS)

    There is a need for displacement and angle measurements in many movable MEMS structures. The use of fibre optical sensors helps to measure micrometre displacements and small rotation angles. Advantages of this type of transducers are their simple design, high precision of processing, low costs and ability of a non-contact measurement. The study shows an analysis of a fibre-optic intensity sensor used for MEMS movable structure rotation angle measurement. An intensity of the light in the photodetector is basically dependent on a distance between a reflecting surface and a head surface of the fibre transmitting arm, and the deflection angle. Experimental tests were made for PMMA 980/1000 plastic fibres, ΘNA=33°. The study shows both analytical and practical results. It proves that calculated and experimental characteristics for the analysed transducers are similar.

  12. EMERGENCE ANGLE OF FLOW OVER AN AERATOR

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Aerator is an important device for release works of hydraulic structures with high-speed flow in order to protect them from cavitation damage. This kind of protecting effect is related closely to cavity length below the aerator, while the cavity length is dominated by the emergence angle over the aerator. Therefore it is crucial to determine this angle accurately. In the present paper the affecting intensities of flow depth and the fluctuating velocity on this angle were analyzed through two introduced parameters. Furthermore, the improved expressions of emergence angle estimation, for both ramp-type and step-type aerators, were presented by means of 68 sets of experimental data from 6 projects based on error theory. The results showed that the present method has higher accuracy than the previously reported methods.

  13. Low angle X-ray scattering

    International Nuclear Information System (INIS)

    The theoretical and experimental problems appearing in diffraction experiments at very low angles by several kinds of materials are discussed. The importance of synchrotron radiation in such problems is shown. (L.C.)

  14. Angles between subspaces and their tangents

    OpenAIRE

    Zhu, Peizhen; Knyazev, Andrew V.

    2012-01-01

    Principal angles between subspaces (PABS) (also called canonical angles) serve as a classical tool in mathematics, statistics, and applications, e.g., data mining. Traditionally, PABS are introduced via their cosines. The cosines and sines of PABS are commonly defined using the singular value decomposition. We utilize the same idea for the tangents, i.e., explicitly construct matrices, such that their singular values are equal to the tangents of PABS, using several approaches: orthonormal and...

  15. Flipped Angles and Phases: A Systematic Study

    OpenAIRE

    Ellis, J.; Lopez, J; Nanopoulos, D.; Olive, K.

    1993-01-01

    We discuss systematically the fermion mass and mixing matrices in a generic \\linebreak field-theoretical flipped $SU(5)$ model, with particular applications to neutrino and baryon number-changing physics. We demonstrate that the different quark flavour branching ratios in proton decay are related to the Cabibbo-Kobayashi-Maskawa angles, whereas the lepton flavour branching ratios are undetermined. The light neutrino mixing angles observable via oscillation effects are related to the heavy con...

  16. Primary angle-closure glaucoma: an update.

    Science.gov (United States)

    Wright, Carrie; Tawfik, Mohammed A; Waisbourd, Michael; Katz, Leslie J

    2016-05-01

    Primary angle-closure glaucoma is potentially a devastating disease, responsible for half of glaucoma-related blindness worldwide. Angle closure is characterized by appositional approximation or contact between the iris and trabecular meshwork. It tends to develop in eyes with shallow anterior chambers, anteriorly positioned or pushed lenses, and angle crowding. Risk of primary angle-closure glaucoma is high among women, the elderly and the hyperopic, and it is most prevalent in Asia. Investigation into genetic mechanisms of glaucoma inheritance is underway. Diagnosis relies on gonioscopy and may be aided by anterior segment optical coherence tomography and ultrasound biomicroscopy. Treatment is designed to control intraocular pressure while monitoring changes to the angle and optic nerve head. Treatment typically begins with medical management through pressure-reducing topical medications. Peripheral iridotomy is often performed to alleviate pupillary block, while laser iridoplasty has been found effective for mechanisms of closure other than pupillary block, such as plateau iris syndrome. Phacoemulsification, with or without goniosynechialysis, both in eyes with existing cataracts and in those with clear lenses, is thus far a viable treatment alternative. Long-term research currently underway will examine its efficacy in cases of angle closure in early stages of the disease. Endoscopic cyclophotocoagulation is another treatment option, which can be combined with cataract surgery. Trabeculectomy remains effective therapy for more advanced cases. PMID:26119516

  17. Viewing angle analysis of integral imaging

    Science.gov (United States)

    Wang, Hong-Xia; Wu, Chun-Hong; Yang, Yang; Zhang, Lan

    2007-12-01

    Integral imaging (II) is a technique capable of displaying 3D images with continuous parallax in full natural color. It is becoming the most perspective technique in developing next generation three-dimensional TV (3DTV) and visualization field due to its outstanding advantages. However, most of conventional integral images are restricted by its narrow viewing angle. One reason is that the range in which a reconstructed integral image can be displayed with consistent parallax is limited. The other is that the aperture of system is finite. By far many methods , an integral imaging method to enhance the viewing angle of integral images has been proposed. Nevertheless, except Ren's MVW (Maximum Viewing Width) most of these methods involve complex hardware and modifications of optical system, which usually bring other disadvantages and make operation more difficult. At the same time the cost of these systems should be higher. In order to simplify optical systems, this paper systematically analyzes the viewing angle of traditional integral images instead of modified ones. Simultaneously for the sake of cost the research was based on computer generated integral images (CGII). With the analysis result we can know clearly how the viewing angle can be enhanced and how the image overlap or image flipping can be avoided. The result also promotes the development of optical instruments. Based on theoretical analysis, preliminary calculation was done to demonstrate how the other viewing properties which are closely related with the viewing angle, such as viewing distance, viewing zone, lens pitch, and etc. affect the viewing angle.

  18. Absolute calibration of small angle neutron scattering data using strong coherent scattering

    OpenAIRE

    Lee, D.; Barker, J; Chen, S.

    1993-01-01

    Typically, small angle neutron scattering (SANS) data is normalized to an absolute scale using secondary standards such as water, polymers, silica gels, or irradiated aluminum. Errors for this method of calibration arise when the initial determination or calculation of the standard's scattering cross-section is no longer valid due to degradation or wavelength-dependent multiple scattering or detector efficiency effects. Here we illustrate how strong coherent scattering can be used to experime...

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

    Science.gov (United States)

    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

  20. Bioelectric impedance phase angle in breast carcinoma

    Directory of Open Access Journals (Sweden)

    Ruchi Tyagi

    2014-01-01

    Full Text Available Context: Worldwide breast cancer is the most frequently diagnosed life threatening cancer and the leading cause of death in women. Bioelectric impedance analysis (BIA affords an emerging opportunity to assess prognosis because of its ability to non invasively assess cell and plasma membrane structure and function by means of phase angle. Aims: To compare the phase angle between patients of breast cancer and their matched control with the help of BIA. Settings and Design: After taking clearance from ethical committee, a total of 34 female cases of histologically proven infiltrating ductal breast carcinoma were included from the surgery IPD, department of surgery. Equal numbers of the matched controls were recruited from the friends and relatives of cases. Materials and Methods: Bio Electrical Impedance Analyzer (BIA BODY STAT QUAD SCAN 4000 was used to measure resistance (R and reactance (Xc by recording a voltage drop in applied current. Phase angle is the ratio of reactance to resistance and is a measure of cell vitality. Statistical analysis used: Unpaired "t" test was applied. Results: In control group, the phase angle showed a mean of 5.479 whereas in test group, it showed a mean value of 4.726. The P value showed a significant difference (P < 0.0001. The smaller the phase angle values were higher was the tumor, nodes, metastases (TNM staging. The phase angles differed significantly from the healthy age matched control values. Conclusions: This study demonstrated that phase angle is a strong predictor of severity of breast cancer and differed significantly between the two groups.

  1. Secondary Victims of Rape

    DEFF Research Database (Denmark)

    Elklit, Ask; Christiansen, Dorte Mølgaard; Bak, Rikke

    2012-01-01

    Rape is often a very traumatic experience, which affects not only the primary victim (PV) but also his/her significant others. Studies on secondary victims of rape are few and have almost exclusively studied male partners of female rape victims. This study examined the impact of rape on 107...... secondary victims, including family members, partners, and friends of male and female rape victims. We found that many respondents found it difficult to support the PV and that their relationship with the PV was often affected by the assault. Furthermore, the sample showed significant levels of...... of social support for the respondent, and feeling let down by others. The respondents were generally interested in friend-, family-, and partner-focused interventions, particularly in receiving education about how best to support a rape victim...

  2. Oral Secondary Syphilis.

    Science.gov (United States)

    Carbone, Peter N; Capra, Gregory G; Nelson, Brenda L

    2016-06-01

    Secondary syphilis develops in approximately 25 % of patients infected with the spirochete bacterium Treponema pallidum. It typically develops several weeks to several months after the primary infection, which is recognized by a painless chancre. Secondary syphilis is characterized by systemic symptoms, such as malaise and fever as well as a maculopapular rash involving the trunk and extremities including the palms and soles. Condyloma lata, which are raised, fleshy lesions, tend to develop at the site of the primary chancre. Diagnosis is achieved primarily through screening and confirmational serologic testing. Histologic findings seen in condyloma lata are largely non-specific. Therefore, a high index of suspicion should be maintained and immunohistochemical stains specific for T. pallidum should be utilized. PMID:25776279

  3. Secondary retroperitoneal teratoma.

    Science.gov (United States)

    Grandjean, P; Danse, E; Thys, F; Cosyns, J P; Wese, F X

    2011-01-01

    Retroperitonal teratomas are rare. We report on a case of a retroperitoneal secondary localisation of a gonadal teratoma in a patient who had developed primary testicular teratoma 12 years previously. The retroperitoneal mass was detected with an abdominal CT requested for the management of a non-specific abdominal pain. CT and MRI examinations showed cystic retroperitoneal masses combined with calcifications and peripheral enhancement. Review of the literature is presented, including the common differential diagnoses to be considered. PMID:22338389

  4. Dynamics of secondary forests

    OpenAIRE

    Breugel, van, W.J.M.

    2007-01-01

    The succession of tropical secondary forests on abandoned agricultural fields has been studied since long, most often by comparing stands of different age since abandonment. These so-called chronosequence studies have yielded much insight in general patterns of succession and the constraints and conditions that affect the course of succession (shortly reviewed in chapter 1). Successional dynamics, however, are inferred rather than directly monitored in such studies; i.e. direction and rates o...

  5. High frequency of labral pathology in dysplastic hips with a CE angle between 20-25

    DEFF Research Database (Denmark)

    Jakobsen, Stig Storgaard; Hartig-Andreasen, Charlotte; Mikkelsen, Lone Rømer;

    Background: Hip dysplasia becomes symptomatic due to labral pathology and secondary muscular pain. A CE angle < 25 is considered pathologic and defined as dysplasia in PAO centres in Denmark. However, it is debated whether a CE angle between 20 and 25 is borderline. Purpose / Aim of Study: We aimed...... to investigate the degree of labral pathology in symptomatic patients with CE between 20 and 25 compared with patients with CE < 20. Materials and Methods: Ninety-nine patients (104 hips) with a mean age 34.1 years (range 14.5- 58.9 years) consecutively scheduled for PAO due to symptomatic DDH were...... enrolled in the study. Five patients were excluded from the study and four patients failed to show up at follow- up, hence 90 patients were evaluated. Indication for PAO were persisting hip pain, a center-edge angle of Wiberg <25, pelvic bone maturity, internal rotation >15, hip flexion <110 and Tönnis...

  6. Protein backbone and sidechain torsion angles predicted from NMR chemical shifts using artificial neural networks

    International Nuclear Information System (INIS)

    A new program, TALOS-N, is introduced for predicting protein backbone torsion angles from NMR chemical shifts. The program relies far more extensively on the use of trained artificial neural networks than its predecessor, TALOS+. Validation on an independent set of proteins indicates that backbone torsion angles can be predicted for a larger, ≥90 % fraction of the residues, with an error rate smaller than ca 3.5 %, using an acceptance criterion that is nearly two-fold tighter than that used previously, and a root mean square difference between predicted and crystallographically observed (φ, ψ) torsion angles of ca 12º. TALOS-N also reports sidechain χ1 rotameric states for about 50 % of the residues, and a consistency with reference structures of 89 %. The program includes a neural network trained to identify secondary structure from residue sequence and chemical shifts

  7. Protein backbone and sidechain torsion angles predicted from NMR chemical shifts using artificial neural networks

    Energy Technology Data Exchange (ETDEWEB)

    Shen Yang; Bax, Ad, E-mail: bax@nih.gov [National Institutes of Health, Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases (United States)

    2013-07-15

    A new program, TALOS-N, is introduced for predicting protein backbone torsion angles from NMR chemical shifts. The program relies far more extensively on the use of trained artificial neural networks than its predecessor, TALOS+. Validation on an independent set of proteins indicates that backbone torsion angles can be predicted for a larger, {>=}90 % fraction of the residues, with an error rate smaller than ca 3.5 %, using an acceptance criterion that is nearly two-fold tighter than that used previously, and a root mean square difference between predicted and crystallographically observed ({phi}, {psi}) torsion angles of ca 12 Masculine-Ordinal-Indicator . TALOS-N also reports sidechain {chi}{sup 1} rotameric states for about 50 % of the residues, and a consistency with reference structures of 89 %. The program includes a neural network trained to identify secondary structure from residue sequence and chemical shifts.

  8. Laser post-ionization secondary neutral mass spectroscopy

    International Nuclear Information System (INIS)

    Three different instruments using laser ionization techniques will be described. Results from the SARISA instrument with a demonstrated figure of merit of .05 (atoms detected/atoms sputtered) for resonance ionization; detection of Fe at the sub-part-per-billion level in ultrapure Si; and features of the instrument such as energy and angle refocusing time-of-flight (EARTOF) mass spectrometer and multiplexing for simultaneous detection of secondary ions and neutrals. 12 refs., 3 figs

  9. Geometric structures on moment-angle manifolds

    International Nuclear Information System (INIS)

    A moment-angle complex ZK is a cell complex with a torus action constructed from a finite simplicial complex K. When this construction is applied to a triangulated sphere K or, in particular, to the boundary of a simplicial polytope, the result is a manifold. Moment-angle manifolds and complexes are central objects in toric topology, and currently are gaining much interest in homotopy theory and complex and symplectic geometry. The geometric aspects of the theory of moment-angle complexes are the main theme of this survey. Constructions of non-Kähler complex-analytic structures on moment-angle manifolds corresponding to polytopes and complete simplicial fans are reviewed, and invariants of these structures such as the Hodge numbers and Dolbeault cohomology rings are described. Symplectic and Lagrangian aspects of the theory are also of considerable interest. Moment-angle manifolds appear as level sets for quadratic Hamiltonians of torus actions, and can be used to construct new families of Hamiltonian-minimal Lagrangian submanifolds in a complex space, complex projective space, or toric varieties. Bibliography: 59 titles

  10. Causes of secondary headache (image)

    Science.gov (United States)

    Temporomandibular joint, or TMJ, dysfunction, can be a cause of secondary headache. Secondary headaches result from underlying disorders which produce pain as a symptom. The TMJ may become painful and dysfunctional as a result ...

  11. High brightness angled cavity quantum cascade lasers

    International Nuclear Information System (INIS)

    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

  12. High brightness angled cavity quantum cascade lasers

    Energy Technology Data Exchange (ETDEWEB)

    Heydari, D.; Bai, Y.; Bandyopadhyay, N.; Slivken, S.; Razeghi, M., E-mail: razeghi@eecs.northwestern.edu [Center for Quantum Devices, Department of Electrical Engineering and Computer Science, Northwestern University, Evanston, Illinois 60208 (United States)

    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.

  13. A heterodyne interferometer for angle metrology

    International Nuclear Information System (INIS)

    We have developed a compact, high-resolution, angle measurement instrument based on a heterodyne interferometer. Common-path heterodyne interferometer metrology is used to measure displacements of a reflective target surface. In the interferometer set up, an optical mask is used to sample the laser beam reflecting back from four areas on a target surface. From the relative displacement measurements of the target surface areas, we can simultaneously determine angular rotations around two orthogonal axes in a plane perpendicular to the measurement beam propagation direction. The device is used in a testbed for a tracking telescope system where pitch and yaw angle measurements of a flat mirror are performed. Angle noise measurement of the device shows 0.1 nrad/√(Hz) at 1 Hz, at a working distance of 1 m. The operation range and nonlinearity of the device when used with a flat mirror is approximately ±0.15 mrad, and 3 μrad rms, respectively.

  14. Notes on large angle crossing graphs

    CERN Document Server

    Dujmovic, Vida; Morin, Pat; Wolle, Thomas

    2009-01-01

    A graph G is an a-angle crossing (aAC) graph if every pair of crossing edges in G intersect at an angle of at least a. The concept of right angle crossing (RAC) graphs (a=Pi/2) was recently introduced by Didimo et. al. It was shown that any RAC graph with n vertices has at most 4n-10 edges and that there are infinitely many values of n for which there exists a RAC graph with n vertices and 4n-10 edges. In this paper, we give upper and lower bounds for the number of edges in aAC graphs for all 0 < a < Pi/2.

  15. Precision measurements of the CKM angle gamma

    CERN Document Server

    CERN. Geneva

    2016-01-01

    The level of CP-violation permitted within the Standard Model cannot account for the matter dominated universe in which we live. Within the Standard Model the CKM matrix, which describes the quark couplings, is expected to be unitary. By making precise measurements of the CKM matrix parameters new physics models can be constrained, or with sufficient precision the effects of physics beyond the standard model might become apparent. The CKM angle gamma is the least well known angle of the unitarity triangle. It is the only angle easily accessible at tree-level, and furthermore has almost no theoretical uncertainties. Therefore it provides an invaluable Standard Model benchmark against which other new physics sensitive tests of the CP-violation can be made. I will discuss recent measurements of gamma using the the Run 1 LHCb dataset, which improve our knowledge of this key parameter.

  16. The wave vane - A device to measure the breaker angle

    Digital Repository Service at National Institute of Oceanography (India)

    Chandramohan, P.; Nayak, B.U.; Anand, N.M.

    , ,~ ~ O BEACH c /~ ' ! , THEODOLITE Fig. 4. Definition sketch. 178 P. CHANDRAMOHAN ET AL. angle AOC can be calculated, which would be the wave breaker angle with respect to the coastline. It is assumed that the angle made by the crestline...

  17. Positron Emission Mammography with Multiple Angle Acquisition

    International Nuclear Information System (INIS)

    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

  18. On Dihedral Angles of a Simplex

    OpenAIRE

    Maehara, H.

    2013-01-01

    For an $n$-simplex, let $\\alpha,\\,\\beta$ denote the maximum, and the minimum dihedral angles of the simplex, respectively. It is proved that the inequality $\\alpha\\le \\arccos(1/n)\\le \\beta$ always holds, and either side equality implies that the $n$-simplex is a regular simplex. Similar inequalities are also given for a star-simplex, which is defined as a simplex that has a vertex (apex) such that the angles between distinct edges incident to the apex are all equal. Further, an explicit formu...

  19. Ship wakes: Kelvin or Mach angle?

    Science.gov (United States)

    Rabaud, Marc; Moisy, Frédéric

    2013-05-24

    From the analysis of a set of airborne images of ship wakes, we show that the wake angles decrease as U(-1) at large velocities, in a way similar to the Mach cone for supersonic airplanes. This previously unnoticed Mach-like regime is in contradiction with the celebrated Kelvin prediction of a constant angle of 19.47° independent of the ship's speed. We propose here a model, confirmed by numerical simulations, in which the finite size of the disturbance explains this transition between the Kelvin and Mach regimes at a Froude number Fr=U/√[gL]~/=0.5, where L is the hull ship length. PMID:23745883

  20. Angle-Resolved Spectroscopy of Parametric Fluorescence

    CERN Document Server

    Hsu, Feng-kuo

    2013-01-01

    The parametric fluorescence from a nonlinear crystal forms a conical radiation pattern. We measure the angular and spectral distributions of parametric fluorescence in a beta-barium borate crystal pumped by a 405-nm diode laser employing angle-resolved imaging spectroscopy. The experimental angle-resolved spectra and the generation efficiency of parametric down conversion are compared with a plane-wave theoretical analysis. The parametric fluorescence is used as a broadband light source for the calibration of the instrument spectral response function in the wavelength range from 450 to 1000 nm.

  1. Ship wakes: Kelvin or Mach angle?

    CERN Document Server

    Rabaud, Marc

    2013-01-01

    From the analysis of a set of airborne images of ship wakes, we show that the wake angles decrease as $U^{-1}$ at large velocities, in a way similar to the Mach cone for supersonic airplanes. This previously unnoticed Mach-like regime is in contradiction with the celebrated Kelvin prediction of a constant angle of $19.47\\degree$ independent of the ship's speed. We propose here a model, confirmed by numerical simulations, in which the finite size of the disturbance explains this transition between the Kelvin and Mach regimes at a Froude number $Fr = U/\\sqrt{gL} \\simeq 0.5$, where $L$ is the hull ship length.

  2. Clinical tibiofemoral angle in south Indian children

    OpenAIRE

    Mathew, S. E.; V. Madhuri

    2013-01-01

    Objectives The development of tibiofemoral angle in children has shown ethnic variations. However this data is unavailable for our population. Methods We measured the tibiofemoral angle (TFA) and intercondylar and intermalleolar distances in 360 children aged between two and 18 years, dividing them into six interrupted age group intervals: two to three years; five to six years; eight to nine years; 11 to 12 years; 14 to 15 years; and 17 to 18 years. Each age group comprised 30 boys and 30 gir...

  3. A fringe shadow method for measuring flapping angle and torsional angle of a dragonfly wing

    Science.gov (United States)

    Zeng, Lijiang; Matsumoto, Hirokazu; Kawachi, Keiji

    1996-05-01

    A fringe shadow (FS) method was developed for measuring the flapping angle and torsional angle of a dragonfly wing during beating motion. This new method involves two sets of fringe patterns projected onto the wing from orthogonal directions. The torsional angle is determined using the length of the shadow of the wing chord that is cast by the two sets of fringe patterns. The flapping angle is determined using the shadowgraph of the wing projected by a laser. The advantages of the FS method are its capability (i) to measure the flapping angle and torsional angle of a dragonfly wing simultaneously using only one high-speed camera and (ii) to recognize the spanwise position of a section from the number of fringes, without having to use diffuse marks that are common in current methods. The resolution of the FS method can be changed easily by adjusting the fringe spacing. The measurement results for the torsional angle and flapping angle of a dragonfly wing prove the effectiveness of the FS method in studying the flight performance of dragonflies.

  4. Secondary glaucoma in CAPN5-associated neovascular inflammatory vitreoretinopathy

    Science.gov (United States)

    Cham, Abdourahman; Bansal, Mayank; Banda, Himanshu K; Kwon, Young; Tlucek, Paul S; Bassuk, Alexander G; Tsang, Stephen H; Sobol, Warren M; Folk, James C; Yeh, Steven; Mahajan, Vinit B

    2016-01-01

    Objective The objective of this study was to review the treatment outcomes of patients with secondary glaucoma in cases of autosomal dominant neovascular inflammatory vitreoretinopathy (ADNIV), a hereditary autoimmune uveitis due to mutations in CAPN5. Patients and methods A retrospective, observational case series was assembled from ADNIV patients with secondary glaucoma. The main outcome measures were intraocular pressure (IOP), visual acuity, use of antiglaucoma medications, ocular surgeries, and adverse outcomes. Perimetry and optic disk optical coherence tomography (OCT) were also analyzed. Results Nine eyes of five ADNIV patients with secondary glaucoma were reviewed. Each received a fluocinolone acetonide (FA) implant for the management of posterior uveitis. Following implantation, no eyes developed neovascular glaucoma. Five eyes (in patients 1, 2, and 5) required Ahmed glaucoma valve surgery for the management of steroid-responsive glaucoma. Patient 2 also developed angle closure with iris bombe and underwent laser peripheral iridotomy. Patient 4 had both hypotony and elevated IOP that required periodic antiglaucoma medication in the FA-implanted eye. Patient 3 did not develop steroid-response glaucoma in either eye. Optic disk examinations were obscured by fibrosis and better assessed with OCT. Conclusion ADNIV patients show combined mechanism secondary glaucoma best assessed by OCT of the optic disk. The FA implants have reduced uveitic and neovascular glaucoma. Nevertheless, IOP management remains complex due to steroid-response glaucoma, angle closure glaucoma, and hypotony. PMID:27390515

  5. Binary asteroid population. 3. Secondary rotations and elongations

    Science.gov (United States)

    Pravec, P.; Scheirich, P.; Kušnirák, P.; Hornoch, K.; Galád, A.; Naidu, S. P.; Pray, D. P.; Világi, J.; Gajdoš, Š.; Kornoš, L.; Krugly, Yu. N.; Cooney, W. R.; Gross, J.; Terrell, D.; Gaftonyuk, N.; Pollock, J.; Husárik, M.; Chiorny, V.; Stephens, R. D.; Durkee, R.; Reddy, V.; Dyvig, R.; Vraštil, J.; Žižka, J.; Mottola, S.; Hellmich, S.; Oey, J.; Benishek, V.; Kryszczyńska, A.; Higgins, D.; Ries, J.; Marchis, F.; Baek, M.; Macomber, B.; Inasaridze, R.; Kvaratskhelia, O.; Ayvazian, V.; Rumyantsev, V.; Masi, G.; Colas, F.; Lecacheux, J.; Montaigut, R.; Leroy, A.; Brown, P.; Krzeminski, Z.; Molotov, I.; Reichart, D.; Haislip, J.; LaCluyze, A.

    2016-03-01

    We collected data on rotations and elongations of 46 secondaries of binary and triple systems among near-Earth, Mars-crossing and small main belt asteroids. 24 were found or are strongly suspected to be synchronous (in 1:1 spin-orbit resonance), and the other 22, generally on more distant and/or eccentric orbits, were found or are suggested to have asynchronous rotations. For 18 of the synchronous secondaries, we constrained their librational angles, finding that their long axes pointed to within 20° of the primary on most epochs. The observed anti-correlation of secondary synchroneity with orbital eccentricity and the limited librational angles agree with the theories by Ćuk and Nesvorný (Ćuk, M., Nesvorný, D. [2010]. Icarus 207, 732-743) and Naidu and Margot (Naidu, S.P., Margot, J.-L. [2015]. Astron. J. 149, 80). A reason for the asynchronous secondaries being on wider orbits than synchronous ones may be longer tidal circularization time scales at larger semi-major axes. The asynchronous secondaries show relatively fast spins; their rotation periods are typically synchronous secondaries with greater elongations appears consistent, considering uncertainties of the axis ratio estimates, with the theory by Ćuk and Nesvorný that predicts large regions of chaotic rotation in the phase space for a2 /b2 ≳√{ 2 } . Alternatively, secondaries may not form or stay very elongated in gravitational (tidal) field of the primary. It could be due to the secondary fission mechanism suggested by Jacobson and Scheeres (Jacobson, S.A., Scheeres, D.J. [2011]. Icarus 214, 161-178), as its efficiency is correlated with the secondary elongation. Sharma (Sharma, I. [2014]. Icarus 229, 278-294) found that rubble-pile satellites with a2 /b2 ≲ 1.5 are more stable to finite structural perturbations than more elongated ones. It appears that more elongated secondaries, if they originally formed in spin fission of parent asteroid, are less likely to survive intact and they more

  6. Ischemia detection from morphological QRS angle changes.

    Science.gov (United States)

    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

  7. Small Angle Light Scattering by Biological Objects

    International Nuclear Information System (INIS)

    In this paper the small angle laser radiation scattering by the particles of different shape and size is analyzed. Experimental results and theoretical calculations show that after ejection from bacteriophage DNA forms the scattering medium consisted of quasi-spherical elements with radius of R⁓10λ0. (author)

  8. Association between Bolton discrepancy and Angle malocclusions

    Directory of Open Access Journals (Sweden)

    Rodrigo Hermont CANÇADO

    2015-01-01

    Full Text Available This study aimed to assess and compare the overall and anterior ratios of tooth size discrepancies in all Angle malocclusion groups. The following null hypothesis (H0 was tested: no difference between tooth size discrepancies (overall and anterior would be observed among Angle malocclusion groups. The sample comprised of 711 pre-orthodontic treatment study casts of Brazilian patients with a mean age of 17.42 years selected from private practices in Brazil. The casts were divided into 3 groups according to the type of malocclusion: Class I (n = 321, Class II (n = 324, and Class III patients (n = 66. The measurement of the greatest mesiodistal width of the teeth was performed using a centesimal precision digital caliper directly on the study casts, from the distal surface of the left first molar to the distal surface of the right first molar. The overall and anterior ratios between the maxillary and mandibular teeth were evaluated using Bolton’s method. The following statistical tests were applied: chi-square, independent t-test, and one-way ANOVA. Results showed that all Angle malocclusions groups exhibited a ratio compatible with those recommended by Bolton. With respect to the overall and anterior ratios among the malocclusion groups, no statistically significant differences were found. The null hypothesis was accepted because the results showed no differences in the overall and anterior ratios of tooth size discrepancies among different Angle malocclusion groups.

  9. Testing CMB polarization data using position angles

    CERN Document Server

    Preece, Michael

    2014-01-01

    We consider a novel null test for contamination which can be applied to CMB polarization data that involves analysis of the statistics of the polarization position angles. Specifically, we will concentrate on using histograms of the measured position angles to illustrate the idea. Such a test has been used to identify systematics in the NVSS point source catalogue with an amplitude well below the noise level. We explore the statistical properties of polarization angles in CMB maps. If the polarization angle is not correlated between pixels, then the errors follow a simple $\\sqrt{N_{pix}}$ law. However this is typically not the case for CMB maps since these have correlations which result in an increase in the variance since the effective number of independent pixels is reduced. Then we illustrate how certain classes of systematic errors can result in very obvious patterns in these histograms, and thus that these errors could possibly be identified using this method. We discuss how this idea might be applied in...

  10. Status of the CDF small angle spectrometer

    International Nuclear Information System (INIS)

    During the 1987 Tevatron collider period the CDF small angle spectrometer system was partially installed and elastic scattering events were recorded in a special high-β run. The design and physics goals of this system are described and results from an analysis of the elastic scattering data are discussed

  11. Improved Beam Angle Control with SPV Metrology

    International Nuclear Information System (INIS)

    A method of real-time monitoring of implant angle for state-of-the-art ion implant doping in integrated circuit manufacturing has been developed using Surface Photo Voltage measurements on conventional monitor wafers. Measurement results are analyzed and compared to other techniques.

  12. Veering triangulations admit strict angle structures

    CERN Document Server

    Hodgson, Craig D; Segerman, Henry; Tillmann, Stephan

    2010-01-01

    Agol recently introduced the concept of a veering taut triangulation, which is a taut triangulation with some extra combinatorial structure. We define the weaker notion of a "veering triangulation" and use it to show that all veering triangulations admit strict angle structures. We also answer a question of Agol, giving an example of a veering taut triangulation that is not layered.

  13. Experimental technique of small angle neutron scattering

    International Nuclear Information System (INIS)

    The main parts of Small Angle Neutron Scattering (SANS) spectrometer, and their function and different parameters are introduced from experimental aspect. Detailed information is also introduced for SANS spectrometer 'Membrana-2'. Based on practical experiments, the fundamental requirements and working condition for SANS experiments, including sample preparation, detector calibration, standard sample selection and data preliminary process are described. (authors)

  14. Mie scattering near the critical angle

    International Nuclear Information System (INIS)

    Complex angular momentum theory is applied to the problem of high-frequency critical light scattering by a spherical cavity near the critical angle. The main contributions to the scattering arise from a critical domain close to critical incidence. The results are in good agreement with the exact Mie solution. (author)

  15. SANS-1: Small angle neutron scattering

    OpenAIRE

    Heinemann, André; Mühlbauer, Sebastian

    2015-01-01

    The new small angle scattering instrument SANS-1, jointly operated by the Technische Universität München and GEMS, Helmholtz-Zentrum Geesthacht, has completed commissioning and is in regular user service (Gilles et al., 2006). SANS-1 is located at the end of neutron guide NL4a in the Neutron Guide Hall West.

  16. Small angle neutron scattering in invar alloys

    International Nuclear Information System (INIS)

    Some results of low angle neutron scattering on 70-30 and 65-35 FeNi alloys are presented showing the existence of chemical small clusters associated with a magnetization inhomogeneity. A noticeable result is the appearance of a pseudo-periodical magnetization static fluctuation in a 65-35 FeNi alloy after irradiation with 2 MeV electrons

  17. [Primary and secondary hypocholesterolemia].

    Science.gov (United States)

    Song, Jun-xian; Ren, Jing-yi; Chen, Hong

    2010-10-18

    Hypocholesterolemia is characterized by serum total cholesterol that is lower than the 5th percentile for age and sex, or the cut-off value which predicts the adverse prognosis by epidemiological study. Unlike hypercholesterolemia, physicians pay less attention to the morbidity, causes and consequences of hypocholesterolemia in clinical practice. In fact, hypocholesterolemia is a common dislipidemia, and mainly results from secondary factors. The causes of primary hypocholesterolemia are some disorders owing to genetic mutation in the pathway of cholesterol absorption, biosynthesis or metabolism, including abetalipoproteinemia, hypobetalipoproteinemia, Tangier disease, chylomicron retention disease and inherited disorders of cholesterol biosynthesis. The causes of secondary hypocholesterolemia comprise anemia, hyperthyroidism, malignancy, live disease, critical illness, serious stress, malabsorption or malnutrition, acute or chronic infection, chronic inflammation, and use of some drugs. In addition, what's more important is that hypocholesterolemia can result in some adverse events, such as increased mortality, intracerebral hemorrhage, cancer, infection, adrenal failure, suicide and mental disorder. Therefore, with the practice of intensive lipid-lowering treatment and the tendency to the increased indications of statins, it's high time that physicians attached more importance to hypocholesterolemia. PMID:20957025

  18. Secondary aortoduodenal fistula

    Institute of Scientific and Technical Information of China (English)

    Girolamo Geraci; Franco Pisello; Francesco Li Volsi; Tiziana Facella; Lina Platia; Giuseppe Modica; Carmelo Sciumè

    2008-01-01

    Aorto-duodenal fistulae (ADF) are the most frequent aorto-enteric fistulae (80%), presenting with upper gastrointestinal bleeding. We report the first case of a man with a secondary aorto-duodenal fistula presenting with a history of persistent occlusive syndrome. A 59-year old man who underwent an aortic-bi-femoral bypass 5 years ago, presented with dyspepsia and biliary vomiting. Computed tomography scan showed in the third duodenal segment the presence of inflammatory tissue with air bubbles between the duodenum and prosthesis, adherent to the duodenum. The patient was submitted to surgery, during which the prosthesis was detached from the duodenum, the intestine failed to close and a gastro-jejunal anastomosis was performed. The post-operative course was simple, secondary ADF was a complication (0.3%-2%) of aortic surgery. Mechanical erosion of the prosthetic material into the bowel was due to the lack of interposed retroperitoneal tissue or the excessive pulsation of redundantly placed grafts or septic procedures. The third or fourth duodenal segment was most frequently involved. Diagnosis of ADF was difficult. Surgical treatment is always recommended by explorative laparotomy. ADF must be suspected whenever a patient with aortic prosthesis has digestive bleeding or unexplained obstructive syndrome. Rarely the clinical picture of ADF is subtle presenting as an obstructive syndrome and in these cases the principal goal is to effectively relieve the mechanical bowel obstruction.

  19. Modeling of Reduced Effective Secondary Electron Emission Yield from a Velvet Surface

    CERN Document Server

    Swanson, Charles

    2016-01-01

    Complex structures on a material surface can significantly reduce total secondary electron emission from that surface. A velvet is a surface that consists of an array of vertically standing whiskers. The reduction occurs due to the capture of low-energy, true secondary electrons emitted at the bottom of the structure and on the sides of the velvet whiskers. We performed numerical simulations and developed an approximate analytical model that calculates the net secondary electron emission yield from a velvet surface as a function of the velvet whisker length and packing density, and the angle of incidence of primary electrons. The values of optimal velvet whisker packing density that maximally suppresses secondary electron emission yield are determined as a function of velvet aspect ratio and electron angle of incidence.

  20. The self-secondary crater population of the Hokusai crater on Mercury

    Science.gov (United States)

    Xiao, Zhiyong; Prieur, Nils C.; Werner, Stephanie C.

    2016-07-01

    Whether or not self-secondaries dominate small crater populations on continuous ejecta deposits and floors of fresh impact craters has long been a controversy. This issue potentially affects the age determination technique using crater statistics. Here the self-secondary crater population on the continuous ejecta deposits of the Hokusai crater on Mercury is unambiguously recognized. Superposition relationships show that this population was emplaced after both the ballistic sedimentation of excavation flows and the subsequent veneering of impact melt, but it predated the settlement and solidification of melt pools on the crater floor. Fragments that formed self-secondaries were launched via impact spallation with large angles. Complex craters on the Moon, Mercury, and Mars probably all have formed self-secondaries populations. Dating young craters using crater statistics on their continuous ejecta deposits can be misleading. Impact melt pools are less affected by self-secondaries. Overprint by subsequent crater populations with time reduces the predominance of self-secondaries.

  1. Measurement of energy distributions of secondary electrons ejected from water vapor by fast electrons

    Energy Technology Data Exchange (ETDEWEB)

    Vroom, D.A.; Palmer, R.L.

    1977-04-15

    Energy distributions of the secondary electrons ejected from water vapor ionized by fast electrons have been measured. The energies of the primary electron beam ranged from 1 to 10 keV and ejected electron energies up to 300 eV were considered. Measurement of the secondary electron spectra has been made for electrons ejected over the total sphere and at angles of 30degree, 60degree, 90degree, 120degree, and 150degree with respect to the primary electron beam.

  2. Secondary restless legs syndrome

    Directory of Open Access Journals (Sweden)

    SHEN Yun

    2013-05-01

    Full Text Available This paper reviewed the latest findings related to secondary restless legs syndrome (RLS systematically. There were a variety of causes. Renal failure, injury of spinal cord and peripheral nerve were related risk factors. During pregnancy, the levels of folic acid and iron diminished and many hormone levels underwent significant changes, which might also be predisposing factors for RLS. The underlying dopamine dysfunction might affect Pakinson's disease (PD patients with RLS symptoms. In addition, there were some evidences which would illustrate some drugs (mainly antidepressants, antipsychotics, histamine receptor antagonist, smoking, caffeine, alcohol and migraine might be associated with the prevalence of RLS, or even the severity of the disease. Clinicians should pay more attention to early diagnosis and treatment plan to improve the quality of life of these patients.

  3. HANARO secondary coolant management

    International Nuclear Information System (INIS)

    In this report, the basic theory for management of water quality, environmental factors influencing to the coolant, chemicals and its usage for quality control of coolant are mentioned, and water balance including the loss rate by evaporation (34.3 m3/hr), discharge rate (12.665 m3/hr), concentration ratio and feed rate (54.1 m3/hr) are calculated at 20 MW operation. Also, the analysis data of HANSU Limited for HANARO secondary coolant (feed water and circulating coolant) - turbidity, pH, conductivity, M-alkalinity, Ca-hardness, chloride ion, total iron ion, phosphoric ion and conversion rate are reviewed. It is confirmed that the feed water has good quality and the circulating coolant has been maintained within the control specification in general, but some items exceeded the control specification occasionally. Therefore it is judged that more regular discharge of coolant is needed. (author). 6 refs., 17 tabs., 18 figs

  4. Secondary standards dosimetry laboratories

    International Nuclear Information System (INIS)

    The Secondary Standards Dosimetry Laboratory (SSDL) is part of an international network of dosimetry laboratories established by the IAEA and WHO. The network services maintain the consistency and accuracy of the therapeutic dose by exercising a national and international intercomparison program as well as providing calibration services to the end users, mainly radiotherapy departments in hospitals. The SSDL's are designated by national laboratories (such as Primary Standards Dosimetry Laboratories, PSDL's) to provide national and international absorbed dose traceability for users in that country. The advantage of the SSDL is that the absorbed dose measurements are consistent among the stakeholder countries.The Physics and Safety divisions have recently re-established an SSDL at ANSTO. The SSDL utilises a collimated cobalt-60 source of activity 170 TBq and dose rate of SmGy/sec at 1 metre (within ±2%), and provides a service to calibrate therapy level thimble ionisation chambers and electrometers

  5. Selfcalibrating secondary emission quantometer

    International Nuclear Information System (INIS)

    Self-calibrating secondary emission quantometer (SEQ), providing the monitoring parameters of powerfull pulse beam of bremsstrahlung is described. SEQ is composed of an assembly of emitter and collector sheet-electrodes, in which collector sheets are isolated. Each collector sheet is connected through commutator with measuring device, thermometer, heating element and cooling jacket, isolated one from another and connected through commutator with measuring device are installed in each emitter sheet. Simultaneous measuring and comparison of sum signals from all thermometers and all collector sheets is equivalent to absolute calibration of SEQ. SEQ enables to determine during one run the apparent beam energy and measurement of bremsstrahlung spectrum. The prototype of self-calibrating SEQ, having sensitivity, stable in the limits of +-1% in 100 - 103 MeV energy range and 10-5 - 103 Wxsm-2 beam power range is under development

  6. Gaia: focus, straylight and basic angle

    CERN Document Server

    Mora, A; Bombrun, A; Boyadian, 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

    2016-01-01

    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. Choroidal physiology and primary angle closure disease.

    Science.gov (United States)

    Zhang, Xiulan; Wang, Wei; Aung, Tin; Jonas, Jost B; Wang, Ningli

    2015-01-01

    Primary angle closure disease (PACD), prevalent in Asian countries, is generally associated with a shallower anterior chamber, a shorter axial length, thicker lens, hyperopia, and female sex. Other physiologic factors, however, may be important, especially with regard to triggering acute primary angle closure. Thickening of the choroid has been demonstrated in untreated and treated, acute and chronic PACD eyes. Recently, there has been growing interest in studying the role of the choroid in the pathophysiology of PACD. The emergence of new imaging technology such as the enhanced depth imaging mode of spectral-domain optical coherence tomography and swept-source optical coherence tomography has contributed to understanding PACD pathologies. We summarize the functions of the choroid and choroidal changes in the pathogenesis of PACD, and discuss potential future developments. PMID:26164737

  8. Weak mixing angle measurements at hadron colliders

    CERN Document Server

    Di Simone, Andrea; The ATLAS collaboration

    2015-01-01

    The Talk will cover weak mixing angle measurements at hadron colliders ATLAS and CMS in particular. ATLAS has measured the forward-backward asymmetry for the neutral current Drell Yan process in a wide mass range around the Z resonance region using dielectron and dimuon final states with $\\sqrt{s}$ =7 TeV data. For the dielectron channel, the measurement includes electrons detected in the forward calorimeter which extends the covered phase space. The result is then used to extract a measurement of the effective weak mixing angle. Uncertainties from the limited knowledge on the parton distribution functions in the proton constitute a significant part of the uncertainty and a dedicated study is performed to obtain a PDF set describing W and Z data measured previously by ATLAS. Similar studies from CMS will be reported.

  9. The Contact Angle in Inviscid Fluid Mechanics

    Indian Academy of Sciences (India)

    P N Shankar; R Kidambi

    2005-05-01

    We show that in general, the specification of a contact angle condition at the contact line in inviscid fluid motions is incompatible with the classical field equations and boundary conditions generally applicable to them. The limited conditions under which such a specification is permissible are derived;however, these include cases where the static meniscus is not flat. In view of this situation, the status of the many `solutions’ in the literature which prescribe a contact angle in potential flows comes into question. We suggest that these solutions which attempt to incorporate a phenomenological, but incompatible, condition are in some, imprecise sense `weak-type solutions’;they satisfy or are likely to satisfy, at least in the limit, the governing equations and boundary conditions everywhere except in the neighbourhood of the contact line. We discuss the implications of the result for the analysis of inviscid flows with free surfaces.

  10. Sparse regularization in limited angle tomography

    CERN Document Server

    Frikel, Jürgen

    2011-01-01

    We investigate the reconstruction problem of limited angle tomography. Such problems arise naturally in applications like digital breast tomosynthesis, dental tomography, electron microscopy etc. Since the acquired tomographic data is highly incomplete, the reconstruction problem is severely ill-posed and the traditional reconstruction methods, such as filtered backprojection (FBP), do not perform well in such situations. To stabilize the reconstruction procedure additional prior knowledge about the unknown object has to be integrated into the reconstruction process. In this work, we propose the use of the sparse regularization technique in combination with curvelets. We argue that this technique gives rise to an edge-preserving reconstruction. Moreover, we show that the dimension of the problem can be significantly reduced in the curvelet domain. To this end, we give a characterization of the kernel of limited angle Radon transform in terms of curvelets and derive a characterization of solutions obtained thr...

  11. Modeling small angle scattering data using FISH

    International Nuclear Information System (INIS)

    Full text: Small angle neutron scattering (SANS) and small angle x-ray scattering (SAXS) are important techniques for the characterisation of samples on the nanometer scale. From the scattered intensity pattern information about the sample such as particle size distribution, concentration and particle interaction can be determined. Since the experimental data is in reciprocal space and information is needed about real space, modeling of the scattering data to obtain parameters is extremely important and several paradigms are available. The use of computer programs to analyze the data is imperative for a robust description of the sample to be obtained. This presentation gives an overview of the SAS process and describes the data-modeling program FISH, written by R. Heenan 1983-2000. The results of using FISH to obtain the particle size distribution of bubbles in the aluminum hydrogen system and other systems of interest are described. Copyright (2002) Australian X-ray Analytical Association Inc

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

    Science.gov (United States)

    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.

  13. The small angle diffractometer SANS at PSI

    Energy Technology Data Exchange (ETDEWEB)

    Wagner, W. [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

    1996-11-01

    With the start-up of SINQ an instrument for small angle neutron scattering will be operational which compares well with the world`s largest and most powerful facilities of this kind. Following the classical principle of the D11-instrument of ILL, it is equipped with state-of-the-art components as are nowadays available, including options for further upgrading. Great emphasis was laid upon providing a flexible, universal multi-user facility which guarantees a comfortable and reliable operation. In the present paper, the principle layout of the instrument is presented, and the individual components are described in detail. The paper concludes with model application of small angle scattering to a system of dilute CuCo alloys which undergo a phase separation under thermal treatment, forming spherical Co-precipitates dispersed in a Cu-rich matrix. (author) 3 figs., 1 tab., 14 refs.

  14. Foreign Body Embedded in Anterior Chamber Angle

    OpenAIRE

    Shmuel Graffi; Beatrice Tiosano; Ran Ben Cnaan; Jonathan Bahir; Modi Naftali

    2012-01-01

    Introduction. We present a case of a metallic foreign body embedded in the anterior chamber angle. After standing in close proximity to a construction worker breaking a tile, a 26-year-old woman using soft contact lens for the correction of mild myopia presented to emergency department for evaluation of a foreign body sensation of her right eye. Methods and Results. Diagnosis was confirmed by gonioscopic examination and a noncontrast CT scan of head and orbits. The foreign body was removed by...

  15. Cognitive models for the concept of angle

    OpenAIRE

    Matos, José Manuel Leonardo de

    1999-01-01

    The instructional models taught in class were similar to the students' models. The teachers addressed angle as a basic-level category, discussed its submodels, clarified the boundaries, and established cognitive reference points. They gradually increased the use of complex metaphors and of several models. The study enriched the characterization of the first two levels of van Hiele theory and demonstrated the value of categorization theory in understanding how our comprehension ...

  16. Lorentz angle measurements in silicon detectors

    Energy Technology Data Exchange (ETDEWEB)

    Bartsch, V.; Boer, W. de E-mail: wim.de.boer@cern.ch; Bol, J.; Dierlamm, A.; Grigoriev, E.; Hauler, F.; Heising, S.; Herz, O.; Jungermann, L.; Keraenen, R.; Koppenhoefer, M.; Roederer, F.; Schneider, T

    2002-02-01

    In this paper we study the Lorentz angles of both electrons and holes in magnetic fields up to 8 T and temperatures between 77 and 300 K. This is done before and after irradiating a detector with 21 MeV protons up to a fluence of 10{sup 13}/cm{sup 2}, which is equivalent to {approx}2.8x10{sup 13}/cm{sup 2} 1 MeV neutrons.

  17. Low angle resistivity anomaly in layered superconductors

    International Nuclear Information System (INIS)

    The pinning effect of vortex lines by the layered structure (intrinsic pinning) on resistivity of high-Tc, 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

  18. Angles between subspaces computed in Clifford Algebra

    OpenAIRE

    Hitzer, Eckhard

    2013-01-01

    We first review the definition of the angle between subspaces and how it is computed using matrix algebra. Then we introduce the Grassmann and Clifford algebra description of subspaces. The geometric product of two subspaces yields the full relative angular information in an explicit manner. We explain and interpret the result of the geometric product of subspaces gaining thus full practical access to the relative orientation information.

  19. Chapter V: Secondary landscape structure

    International Nuclear Information System (INIS)

    This chapter deals with the secondary landscape structure of the Slovak Republic. It consists of next subchapters: (1) Land use pattern; (2) Special landscape structures; (3) Real vegetation. The secondary landscape structure consists of the elements influenced by man, created or recreated. They represent material elements with a particular spatial delimitation in the landscape. Vegetation, above all forest vegetation, is the indispensable part of the secondary landscape structure. Special space was given to the historical landscape structure

  20. Oral Manifestations of Secondary Syphilis

    Directory of Open Access Journals (Sweden)

    Luiz Fernando Barbosa de Paulo

    2015-06-01

    Full Text Available Known as “the great imitator,” secondary syphilis may clinically manifest itself in myriad ways, involving different organs including the oral mucosa, and mimicking, both clinically and histologically, several diseases, thereby making diagnosis a challenge for clinicians. We highlight the clinical aspects of oral manifestation in 7 patients with secondary syphilis. Clinicians should consider secondary syphilis in the differential diagnosis of ulcerative and/or white oral lesions.

  1. Studies in small angle scattering techniques

    International Nuclear Information System (INIS)

    Small angle scattering of neutrons, X-rays and γ-rays are found among the spectroscopic methods developed in the recent years. Although these techniques differ from each other in many respects, e.g. radiation sources and technical equipment needed, their power to resolve physical phenomena and areas of application can be discussed in a general scheme. Selected examples are given illustrating the use of specific technical methods. Jahn-Teller driven structural phase transitions in Rare Earth zircons were studied with neutron scattering as well as small angle γ-ray diffraction. The study of neutron scattering from formations of magnetic domains in the Ising ferromagnet LiTbF4 is a second example. Both these examples represent more than experimental test cases since the theoretical interpretations of the data obtained are discussed as well. As a last example the use of small angle scattering methods for the study of molecular biological samples is discussed. In particular the experimental procedures used in connection with scattering from aqueous solutions of proteins and protein complexes are given. (Auth.)

  2. Moment-angle complexes from simplicial posets

    CERN Document Server

    Lu, Zhi

    2009-01-01

    We extend the construction of moment-angle complexes to simplicial posets by associating a certain T^m-space Z_S to an arbitrary simplicial poset S on m vertices. Face rings Z[S] of simplicial posets generalise those of simplicial complexes, but have much more complicated algebraic structure. Our primary motivation is to study the face rings Z[S] by topological methods. The space Z_S has many important topological properties of the original moment-angle complex Z_K associated to a simplicial complex K. In particular, we prove that the integral cohomology algebra of Z_S is isomorphic to the Tor-algebra of the face ring Z[S]. This leads directly to a generalisation of Hochster's theorem, expressing the algebraic Betti numbers of the ring Z[S] in terms of the homology of full subposets in S. Finally, we estimate the total amount of homology of Z_S from below by proving the toral rank conjecture for the moment-angle complexes Z_S.

  3. Off-Angle Iris Correction Methods

    Energy Technology Data Exchange (ETDEWEB)

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

    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.

  4. Evaluation of fluidic thrust vectoring nozzle via thrust pitching angle and thrust pitching moment

    Science.gov (United States)

    Li, L.; Hirota, M.; Ouchi, K.; Saito, T.

    2016-03-01

    Shock vector control (SVC) in a converging-diverging nozzle with a rectangular cross-section is discussed as a fluidic thrust vectoring (FTV) method. The interaction between the primary nozzle flow and the secondary jet is examined using experiments and numerical simulations. The relationships between FTV parameters [nozzle pressure ratio (NPR) and secondary jet pressure ratio (SPR)] and FTV performance (thrust pitching angle and thrust pitching moment) are investigated. The experiments are conducted with an NPR of up to 10 and an SPR of up to 2.7. Numerical simulations of the nozzle flow are performed using a Navier-Stokes solver with input parameters set to match the experimental conditions. The thrust pitching angle and moment computed from the force-moment balance are used to evaluate FTV performance. The experiment and numerical results indicate that the FTV parameters (NPR and SPR) directly affect FTV performance. Conventionally, FTV performance evaluated by the common method using thrust pitching angle is highly dependent on the location of evaluation. Hence, in this study, we show that the thrust pitching moment, a parameter which is independent of the location, is the appropriate figure of merit to evaluate the performance of FTV systems.

  5. Osteoporosis secundarias Secondary osteoporosis

    Directory of Open Access Journals (Sweden)

    J. Lafita

    2003-01-01

    Full Text Available Se denomina osteoporosis secundaria a aquella que es causada por patologías o medicaciones, distintas a la pérdida ósea explicable por la etapa postmenopáusica o envejecimiento. Las posibles patologías que pueden condicionar la pérdida de masa ósea son muy variadas: endocrinológicas, digestivas, genéticas, hematológicas, reumáticas, post-transplante, farmacológicas y un amplio grupo misceláneo. En el artículo se revisan esencialmente las causas endocrinológicas, con especial énfasis en los aspectos más controvertidos en la actualidad, seguidos de una aproximación clínica para el diagnóstico sistemático de estas patologías, frecuentes en los casos etiquetados inicialmente de osteoporosis primaria.Secondary osteoporosis is caused by pathologies or medications, differing from the bone loss explainable by the post-menopausal stage or by ageing. The possible pathologies that can condition the loss of bone mass are very varied: endocrinological, digestive, genetic, haematological, rheumatic, post-transplant, pharmacological and a wide miscellaneous group. This article essentially reviews the endocrinological causes, with special emphasis on the more controversial aspects, followed by a clinical approach for the systematic diagnosis of these pathologies, which are frequent in cases initially labelled as primary osteoporosis.

  6. Professionalism: secondary goals

    Directory of Open Access Journals (Sweden)

    Raschke RA

    2014-06-01

    Full Text Available No abstract available. Article truncated at 150 words. Please recall my lengthy disclaimer from Part 1 of this series. In part two, we reviewed the Oath of Maimonides. We considered our profession as a sacred vocation. We defined professionalism: A good doctor can be trusted to always place his/her individual patient’s best interest first, with ability, good judgment, and a caring attitude. We determined that we should be willing to make sacrifices in our commitment to our primary goal (as critical care physicians – getting our patients and their families through their illness with as little disability and suffering as possible. Now, my second disclaimer – I am going to express my opinions from atop my Ivory Tower – as I am not in private practice, and protected a bit from the harsh reality of the business world. I am going to express my possibly somewhat naive perspective on secondary goals related to our profession. These are not necessarily bad, but ...

  7. Perceptions of tilt angles of an agricultural tractor.

    Science.gov (United States)

    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

  8. Performance Art at Secondary Level

    Science.gov (United States)

    Horn, Sheridan

    2009-01-01

    This article considers the far-reaching potential and the particular characteristics of performance art within the secondary art curriculum. It discusses the means by which an art department has incorporated it into their teaching curriculum at a state secondary school with reference to installations and the work of different performance artists…

  9. Secondary standard dosimetry laboratory (SSDL)

    International Nuclear Information System (INIS)

    A secondary Standard Dosimetry Laboratory has been established in the Tun Ismail Research Centre, Malaysia as a national laboratory for reference and standardization purposes in the field of radiation dosimetry. This article gives brief accounts on the general information, development of the facility, programmes to be carried out as well as other information on the relevant aspects of the secondary standard dosimetry laboratory. (author)

  10. Sun, shade, and secondary metabolites

    Science.gov (United States)

    My research program focuses on understanding plant primary and secondary metabolites. Grape secondary metabolites, such as phenolics, have long been valuable for the organoleptic properties they impart to fruit and wine, and, more recently, for their possible health benefits. These compounds develop...

  11. Metabolomics for Secondary Metabolite Research

    Directory of Open Access Journals (Sweden)

    Eriko Takano

    2013-11-01

    Full Text Available Metabolomics, the global characterization of metabolite profiles, is becoming an increasingly powerful tool for research on secondary metabolite discovery and production. In this review we discuss examples of recent technological advances and biological applications of metabolomics in the search for chemical novelty and the engineered production of bioactive secondary metabolites.

  12. The effect of lens parameters on the development of the primary angle-closure glaucoma

    Institute of Scientific and Technical Information of China (English)

    Zhaohui Feng; Naixue Sun; Aiyi Zhou; Donggang Han; Yun Long; Zhao Wang; Xiaohua Wang

    2007-01-01

    Objective:To investigate the role the lens dimensions played on the pathogenesis of primary angle-closure glaucoma.Methods:38 eyes of 20 patients with primary angle-closure glaucoma (PACG) and 35 eyes of 22 normal individuals without ocular abnormalities were examined. The anatomical parameters of the lens and other structures of the anterior segment were calculated using B ultrasound, computer image processing and ultrasound biomicroscopy (UBM). The parameters were compared between the patients and normal subjects. Correlation analysis was used to determine the relationship between the radii of curvature of the anterior lens surface (RCALS) and the other parameters of the anterior segment. Results:Compared with the normal eyes, the eyes of PACG had thicker lens, steeper curvature of anterior lens surface, decreased depth of the anterior chamber, narrower chamber angle, and more anterior position of the ciliary bodies and lens. All these differences were significant(P < 0.05 or P < 0.01). In the PACG group, the RCALS had significantly negative correlation with the central and peripheral lens thickness (P < 0.01 and P < 0.05 respectively), and had positive correlation with relative lens position, anterior chamber depth (ACD), angle-open distance at 500 um(AOD500), trabecular iris angle(TIA) and trabecular ciliary processes distance(TCPD, P < 0.05 or P < 0.01 ). Conclusion:The occurrence of PACG is relevant to the abnormal anatomical structures of the anterior segment. Among all factors, the lens parameters play an important role in the pathogenesis. Increased lens thickness, relative more anterior position of lens, especially steepened curvature of anterior lens surface are predisposing factors of the pathologic phenomenon in PACG including pupillary blockage, shallow anterior chamber, secondary closure of chamber angle and elevation of intraocular pressure.

  13. Adventitious Roots and Secondary Metabolism

    Institute of Scientific and Technical Information of China (English)

    Hosakatte Niranjana Murthy; Eun Joo Hahn; Kee Yoeup Paek

    2008-01-01

    Plants are a rich source of valuable secondary metabolites and in the recent years plant cell, tissue and organ cultures have been developed as an important alternative sources for the production of these compounds. Adventitious roots have been successfully induced in many plant species and cultured for the production of high value secondary metabolites of pharmaceutical, nutraceutical and industrial importance. Adoption of elicitation methods have shown improved synthesis of secondary metabolites in adventitious root cultures. Development of large-scale culture methods using bioreactors has opened up feasibilities of production of secondary metabolites at the industrial levels. In the present review we summarize the progress made in recent past in the area of adventitious root cultures for the production of secondary metabolites.

  14. Secondary anisotropies of the CMB

    International Nuclear Information System (INIS)

    The Cosmic Microwave Background fluctuations provide a powerful probe of the dark ages of the universe through the imprint of the secondary anisotropies associated with the reionization of the universe and the growth of structure. We review the relation between the secondary anisotropies and the primary anisotropies that are directly generated by quantum fluctuations in the very early universe. The physics of secondary fluctuations is described, with emphasis on the ionization history and the evolution of structure. We discuss the different signatures arising from the secondary effects in terms of their induced temperature fluctuations, polarization and statistics. The secondary anisotropies are being actively pursued at present, and we review the future and current observational status

  15. Cellular compartmentalization of secondary metabolism

    Directory of Open Access Journals (Sweden)

    H. Corby eKistler

    2015-02-01

    Full Text Available Fungal secondary metabolism is often considered apart from the essential housekeeping functions of the cell. However, there are clear links between fundamental cellular metabolism and the biochemical pathways leading to secondary metabolite synthesis. Besides utilizing key biochemical precursors shared with the most essential processes of the cell (e.g. amino acids, acetyl CoA, NADPH, enzymes for secondary metabolite synthesis are compartmentalized at conserved subcellular sites that position pathway enzymes to use these common biochemical precursors. Co-compartmentalization of secondary metabolism pathway enzymes also may function to channel precursors, promote pathway efficiency and sequester pathway intermediates and products from the rest of the cell. In this review we discuss the compartmentalization of three well-studied fungal secondary metabolite biosynthetic pathways for penicillin G, aflatoxin and deoxynivalenol, and summarize evidence used to infer subcellular localization. We also discuss how these metabolites potentially are trafficked within the cell and may be exported.

  16. Analyzing biomolecular interactions by variable angle ellipsometry

    Science.gov (United States)

    Wu, Jiun-Yan; Lee, Chih-Kung; Lee, J. H.; Shiue, Shuen-Chen; Lee, Shu-Sheng; Lin, Shiming

    2001-10-01

    In this paper, an innovative ellipsometer is developed and applied to metrology of the biomolecular interaction on a protein biochip. Both the theory, optical and opto-mechanical configurations of this newly developed ellipsometer and methodologies adopted in system design to improve the system performance are presented. It will be shown that by measuring the ellipsometric parameters, the corresponding concentration variation in biochemical reaction can be calculated according to stoichiometry analysis. By applying the variable angle ellipsometry to analysis of a multi-layered sample, the thickness and concentration are resolved. It is believed that the newly developed ellipsometer biosensor is able to undertake an accurate measurement on biomedical interaction.

  17. CDF status report on small angle physics

    International Nuclear Information System (INIS)

    The 1988-1989 Tevatron Collider run at Fermilab was very fruitfull for CDF. More than 4.5 inverse pbarn were written to tape with a trigger emphasizing hard, short distance interactions. A minor part of the run was devoted to special high - beta runs for the measurement of σtot, σel, dσel/dt and of diffraction dissociation. These measurements are performed in CDF with a double-arm magnetic spectrometer at extremely small angles around the beam pipe and a tracking detector surrounding completely the interaction region. The design and the performance of these systems are described and the quality of data is discussed. (orig.)

  18. Small angles Bhabha scattering: two loop approximation

    International Nuclear Information System (INIS)

    The elastic and inelastic cross sections for small angles e+e- scattering at high energies are considered. We prove that all the diagrams with two or more virtual photons in scattering channel may be omitted when calculating the radiative corrections with accuracy of the order 0.1%. It is the consequence of the generalized eikonal representation for elastic and inelastic amplitudes. We take into account the processes of single and double bremsstrahlung in the same and opposite directions and the pair production processes. Basing on this calculations we construct the combined formula for the inclusive scattering electron and positron cross section in terms of the structure functions. 15 refs.; 10 figs

  19. Optimum Staging with Varying Thrust Attitude Angle

    Directory of Open Access Journals (Sweden)

    T. N. Srivastava

    1966-07-01

    Full Text Available Optimum staging programme for step rockets of arbitrary number of stages having different specific impulses and mass fractions with stages is derived, the optimization criterion being minimum take-off weight for a desired burntout velocity at an assigned altitude. Variation of thrust attitude angle from stage to stage and effects of gravity factor are taken into account. Analysis is performed for a degenerate problem obtained by relaxing the altitude constraint and it has been shown that problems of Weisbord, Subotowicz, Hall & Zambelli and Malina & Summerfield are the particular cases of the degenerate problem.

  20. Euler angles as torsional flat spaces

    Science.gov (United States)

    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.

  1. Spin stability of sounding rocket secondary payloads following high velocity ejections

    Science.gov (United States)

    Nelson, Weston M.

    The Auroral Spatial Structures Probe (ASSP) mission is a sounding rocket mission studying solar energy input to space weather. ASSP requires the high velocity ejection (up to 50 m/s) of 6 secondary payloads, spin stabilized perpendicular to the ejection velocity. The proposed scientific instrumentation depends on a high degree of spin stability, requiring a maximum coning angle of less than 5°. It also requires that the spin axis be aligned within 25° of the local magnetic field lines. The maximum velocities of current ejection methods are typically less than 10m/s, and often produce coning angles in excess of 20°. Because of this they do not meet the ASSP mission requirements. To meet these requirements a new ejection method is being developed by NASA Wallops Flight Facility. Success of the technique in meeting coning angle and B-field alignment requirements is evaluated herein by modeling secondary payload dynamic behavior using a 6-DOF dynamic simulation employing state space integration written in MATLAB. Simulation results showed that secondary payload mass balancing is the most important factor in meeting stability requirements. Secondary mass payload properties will be measured using an inverted torsion pendulum. If moment of inertia measurement errors can be reduced to 0.5%, it is possible to achieve mean coning and B-field alignment angles of 2.16° and 2.71°, respectively.

  2. Improving the precision and speed of Euler angles computation from low-cost rotation sensor data.

    Science.gov (United States)

    Janota, Aleš; Šimák, Vojtech; Nemec, Dušan; Hrbček, Jozef

    2015-01-01

    This article compares three different algorithms used to compute Euler angles from data obtained by the angular rate sensor (e.g., MEMS gyroscope)-the algorithms based on a rotational matrix, on transforming angular velocity to time derivations of the Euler angles and on unit quaternion expressing rotation. Algorithms are compared by their computational efficiency and accuracy of Euler angles estimation. If attitude of the object is computed only from data obtained by the gyroscope, the quaternion-based algorithm seems to be most suitable (having similar accuracy as the matrix-based algorithm, but taking approx. 30% less clock cycles on the 8-bit microcomputer). Integration of the Euler angles' time derivations has a singularity, therefore is not accurate at full range of object's attitude. Since the error in every real gyroscope system tends to increase with time due to its offset and thermal drift, we also propose some measures based on compensation by additional sensors (a magnetic compass and accelerometer). Vector data of mentioned secondary sensors has to be transformed into the inertial frame of reference. While transformation of the vector by the matrix is slightly faster than doing the same by quaternion, the compensated sensor system utilizing a matrix-based algorithm can be approximately 10% faster than the system utilizing quaternions (depending on implementation and hardware). PMID:25806874

  3. Effects of dopant concentration, crystallographic orientation, and crystal morphology on secondary electron emission from diamond

    International Nuclear Information System (INIS)

    Secondary electron emission properties from crystalline and polycrystalline diamond films containing different boron concentrations were measured. The secondary electron yields δ were high. Yields were independent of incident beam angle and crystallographic orientation. The secondary electron yields were greatest for boron concentrations of 1019 endash 1020 cm-3. The angular distribution was peaked about the surface normal with a half width at half maximum of 37±7 degree. The secondary electron yield decreased with prolonged energetic electron beam bombardment. The energy distribution of the emitted electrons contained a large, relatively narrow, low energy peak that disappeared with extended electron beam bombardment. The large secondary electron yields and narrow energy distributions of the emitted electrons were consistent with nearly thermalized electron emission from negative electron affinity states. copyright 1997 American Institute of Physics

  4. Embedability between right-angled Artin groups

    CERN Document Server

    Kim, Sang-hyun

    2011-01-01

    In this article we study the right-angled Artin subgroups of a given right-angled Artin group. Starting with a graph $\\gam$, we produce a new graph through a purely combinatorial procedure, and call it the extension graph $\\gam^e$ of $\\gam$. We produce a second graph $\\gam^e_k$, the clique graph of $\\gam^e$, by adding extra vertices for each complete subgraph of $\\gam^e$. We prove that each finite induced subgraph $\\Lambda$ of $\\gam^e$ gives rise to an inclusion $A(\\Lambda)\\to A(\\gam)$. Conversely, we show that if there is an inclusion $A(\\Lambda)\\to A(\\gam)$ then $\\Lambda$ is an induced subgraph of $\\gam^e_k$. These results have a number of corollaries. Let $P_4$ denote the path on four vertices and let $C_n$ denote a cycle of length $n$. We prove that $A(P_4)$ embeds in $A(\\gam)$ if and only if $P_4$ is an induced subgraph of $\\gam$. We prove that if $F$ is any finite forest then $A(F)$ embeds in $A(P_4)$. We recover the first author's result on co--contraction of graphs and prove that if $\\gam$ has no tria...

  5. Diphotons, New Vacuum Angles, and Strong CP

    CERN Document Server

    Draper, Patrick

    2016-01-01

    The Standard Model contains a well-understood, natural, spin-0 diphoton resonance: the $\\pi^0$. 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 $\\tilde\\theta$. We discuss the physics of $\\tilde\\theta$ and its impact on the phenomenology of the new sector. We also describe some of the theoretical implications of a nonzero $\\tilde\\theta$. In particular, $\\tilde\\theta$ can generate an ${\\cal O}(1)$ threshold correction to the QCD vacuum angle $\\theta$ near the TeV scale, sharply constraining ultraviolet solutions to the strong CP problem. Alternatively, finding that $\\tilde\\theta$ 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.

  6. Active limited-angle tomographic phase microscope

    Science.gov (United States)

    Kuś, Arkadiusz; Krauze, Wojciech; Kujawińska, Małgorzata

    2015-11-01

    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.

  7. Hidden topological angles and Lefschetz thimbles

    CERN Document Server

    Behtash, Alireza; Schaefer, Thomas; Unsal, Mithat

    2015-01-01

    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 angle 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 $n_f$ to non-integer number of flavors, reducing in the integer $n_f$ limit to a $\\mathbb Z_2$ valued phase difference between dominant saddles. In ${\\cal N}=1$ 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 $SU(N)$ 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 semi-classical expansion. In quantum mechanics, a HTA leads to ...

  8. Cluster headache or narrow angle glaucoma?

    Directory of Open Access Journals (Sweden)

    Prasad Palimar

    1991-01-01

    Full Text Available A 47 year old man with episodes of attacks of pain, redness and mild blurring of vision was investigated for narrow angle glaucoma in view of shallow anterior chambers and a cupped optic disc. The history was reviewed following a spontaneous attack in hospital, which had features other than acute glaucoma. A diagnosis of cluster headache was made on the basis of tests. Cluster headache has been defined as unilateral intense pain, involving the eye and head on one side, usually associated with flushing, nasal congestion and lacrimation; the attacks recurring one or more times daily and lasting 20 - 120 minutes. Such attacks commonly continue for weeks or months and are separated by an asymptomatic period of months to years. This episodic nature, together with unilaterality and tendency to occur at night, closely mimics narrow angle glaucoma. Further, if patients have shallow anterior chambers and disc cupping, the differentiation becomes more difficult yet critical. Resource to provocative tests is often the only answer as the following case report demonstrates.

  9. Contact angles of liquid metals on quasicrystals

    International Nuclear Information System (INIS)

    Wetting with μm-sized Pb droplets on thin polycrystalline films of decagonal Al13Co4 is reported. The films were prepared under high vacuum conditions in order to have Pb droplets lying on a clean surface. The method used is sequential deposition and annealing of specific stackings of Al and Co layers of nanometric thicknesses. A 300 nm thick Pb slab was then deposited on top of the films and dewetting experiments were followed in situ in a scanning Auger microprobe. The contact angle between the Pb droplet and the surface of the film is measured to be 49 deg. ± 7 deg. Further investigation performed by cross section transmission electron microscopy allows us to better characterize the interface. Taking into account the rugosity of the film, it is concluded that there is partial wetting of the film, which corresponds to a smaller contact angle. The comparison with other results obtained either with pure metals or with a cubic AlCo compound leads to the conclusion that the wetting behaviour of Pb on the surface of a decagonal compound is close to that of a metal with a high melting point and not significantly different from that of a crystalline compound with a small unit cell

  10. Diphotons, new vacuum angles, and strong CP

    Science.gov (United States)

    Draper, Patrick; McKeen, David

    2016-04-01

    The Standard Model contains a well-understood, natural, spin-0 diphoton resonance: the π 0. 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 tilde{θ} . We discuss the physics of tilde{θ} and its impact on the phenomenology of the new sector. We also describe some of the theoretical implications of a nonzero tilde{θ} . In particular, tilde{θ} can generate an O(1) threshold correction to the QCD vacuum angle θ near the TeV scale, sharply constraining ultraviolet solutions to the strong CP problem. Alternatively, finding that tilde{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.

  11. Hanford Site Secondary Waste Roadmap

    Energy Technology Data Exchange (ETDEWEB)

    Westsik, Joseph H.

    2009-01-29

    Summary The U.S. Department of Energy (DOE) is making plans to dispose of 54 million gallons of radioactive tank wastes at the Hanford Site near Richland, Washington. The high-level wastes and low-activity wastes will be vitrified and placed in permanent disposal sites. Processing of the tank wastes will generate secondary wastes, including routine solid wastes and liquid process effluents, and these need to be processed and disposed of also. The Department of Energy Office of Waste Processing sponsored a meeting to develop a roadmap to outline the steps necessary to design the secondary waste forms. Representatives from DOE, the U.S. Environmental Protection Agency, the Washington State Department of Ecology, the Oregon Department of Energy, Nuclear Regulatory Commission, technical experts from the DOE national laboratories, academia, and private consultants convened in Richland, Washington, during the week of July 21-23, 2008, to participate in a workshop to identify the risks and uncertainties associated with the treatment and disposal of the secondary wastes and to develop a roadmap for addressing those risks and uncertainties. This report describes the results of the roadmap meeting in Richland. Processing of the tank wastes will generate secondary wastes, including routine solid wastes and liquid process effluents. The secondary waste roadmap workshop focused on the waste streams that contained the largest fractions of the 129I and 99Tc that the Integrated Disposal Facility risk assessment analyses were showing to have the largest contribution to the estimated IDF disposal impacts to groundwater. Thus, the roadmapping effort was to focus on the scrubber/off-gas treatment liquids with 99Tc to be sent to the Effluent Treatment Facility for treatment and solidification and the silver mordenite and carbon beds with the captured 129I to be packaged and sent to the IDF. At the highest level, the secondary waste roadmap includes elements addressing regulatory and

  12. Mining overrepresented 3D patterns of secondary structures in proteins.

    Science.gov (United States)

    Comin, Matteo; Guerra, Concettina; Zanotti, Giuseppe

    2008-12-01

    We consider the problem of finding overrepresented arrangements of secondary structure elements (SSEs) in a given dataset of representative protein structures. While most papers in the literature study the distribution of geometrical properties, in particular angles and distances, between pairs of interacting SSEs, in this paper we focus on the distribution of angles of all quartets of SSEs and on the extraction of overrepresented angular patterns. We propose a variant of the Apriori method that obtains overrepresented arrangements of quartets of SSEs by combining arrangements of triplets of SSEs. This specific case will pose the basis for a natural extension of the problem to any given number of SSEs. We analyze the results of our method on a dataset of 300 nonredundant proteins. Supplementary material is available at (http://www.dei.unipd.it/nciompin/papers/CGZ-jbcb-suppl.pdf/). PMID:19090018

  13. Alternative IR geometries for TESLA with a small crossing angle

    OpenAIRE

    Appleby, R.; Angal-Kalinin, D; Bambade, P.; Mouton, B.; Napoly, O.; Payet, J.; Collaboration, the TESLA

    2004-01-01

    The formulation of hybrid crossing angle schemes has been a recent development of the TESLA collision geometry debate. Here we report on two such schemes, characterised by either a small vertical or horizontal beam crossing angle.

  14. Lateral angle: a method for sexing using the petrous bone

    DEFF Research Database (Denmark)

    Norén, Anna; Lynnerup, Niels; Czarnetzki, Alfred;

    2005-01-01

    very fragmented skeletal remains or cremated bones, where the petrous bone may still be readily recognizable. The method was tested using a forensic sample of 113 petrous bones with known sex. Intra- and interobserver testing was also performed. We found a statistically significant difference in angle......We report on the results of applying the so-called lateral angle method for sex determination on skeletal remains. The lateral angle denotes the angle of the internal auditory canal in relation to the medial surface of the petrous part of the temporal bone. The method involves making a small cast...... size between males and females (mean angle size of males, 39.3 degrees ; mean angle size of females, 48.2 degrees ; P < 0.001). There was no bilateral difference in angle size. In blind trials, 83.2% of petrous bones were assigned to the correct sex. We also tested the lateral angle method against an...

  15. Note on Four Dp-Branes at Angles

    CERN Document Server

    Vancea, I V

    2001-01-01

    In this note we analyse the potential of a system of four Dp-branes at arbitrary angles. The equilibrium configurations for various values of the relative angles and distances among branes are discussed.

  16. Secondary abdominal appendicular ectopic pregnancy.

    Science.gov (United States)

    Nama, Vivek; Gyampoh, Bright; Karoshi, Mahantesh; McRae, Reynold; Opemuyi, Isaac

    2007-01-01

    Although the case fatality rate for ectopic pregnancies has decreased to 0.08% in industrialized countries, it still represents 3.8% of maternal mortality in the United States alone. In developing countries, the case fatality rate varies from 3% to 27%. Laparoscopic management of tubal pregnancies is now the standard form of treatment where this technology is available. Abdominal pregnancies are rare, and secondary implantation of tubal ectopic pregnancies is the most common cause of abdominal gestations. We present an interesting case of secondary implantation of a tubal ectopic pregnancy to highlight the appendix as a possible secondary implantation site after a tubal ectopic pregnancy. PMID:17630175

  17. Modified Wide-angle Beam Propagation Method Using Douglas Operators①

    Institute of Scientific and Technical Information of China (English)

    1997-01-01

    A modified wide-angle beam propagation based on the Douglas operators is presented .The truncation error in the modified wide-angle beam propagation is reduced to o(△x)4in the transverse direction nearly without any increase of the computation time,whereas the error in the ordinary wide-angle beam propagation method is typically o(△x)2.With trivial programming changes,the accuracy is higher,especially in wide-angle propagation.

  18. Range-Angle-Dependent Beamforming by Frequency Diverse Array Antenna

    OpenAIRE

    Wen-Qin Wang; Huaizong Shao; Jingye Cai

    2012-01-01

    This paper proposes a range-angle-dependent beamforming for frequency diverse array (FDA) antenna systems. Unlike conventional phased-array antenna, the FDA antenna employs a small amount of frequency increment compared to the carrier frequency across the array elements. The use of frequency increment generates an antenna pattern that is a function of range, time and angle. The range-angle-dependent beamforming allows the FDA antenna to transmit energy over a desired range or angle. This prov...

  19. Hybrid algorithm for rotor angle security assessment in power systems

    OpenAIRE

    D. Prasad Wadduwage; Udaya D. Annakkage; Christine Qiong Wu

    2015-01-01

    Transient rotor angle stability assessment and oscillatory rotor angle stability assessment subsequent to a contingency are integral components of dynamic security assessment (DSA) in power systems. This study proposes a hybrid algorithm to determine whether the post-fault power system is secure due to both transient rotor angle stability and oscillatory rotor angle stability subsequent to a set of known contingencies. The hybrid algorithm first uses a new security measure developed based on ...

  20. The role of texture-related mobility in the secondary recrystallization of ODS alloys

    Energy Technology Data Exchange (ETDEWEB)

    Miodownik, M.A. [Oxford Univ. (United Kingdom). Dept. of Materials; Wilkinson, A.J. [Oxford Univ. (United Kingdom). Dept. of Materials; Martin, J.W. [Oxford Univ. (United Kingdom). Dept. of Materials

    1996-09-01

    The origin of the strong left angle 100 right angle fibre texture observed after the secondary recrystallisation of ODS MA754 has been investigated by FEG-SEM EBSP. The as-extruded material had a weak left angle 100 right angle - left angle 111 right angle fibre texture. It has been found that the as-received grain size is in fact bimodal, in contrast to the observed uniformity of initial grain size reported in other MA superalloys. The present SEM study has revealed occasional grains (embryos) that possess a 10-fold size advantage over the matrix grains. The orientation of these embryos includes that of the final texture, and their average misorientations with respect to the matrix grains have been calculated. The growing grains cannot be described in terms of a specific misorientation with the matrix, and it is concluded that the triggering of the left angle 100 right angle embryos must have its origin in the local (meso-) texture reducing the local solute pinning. (orig.)

  1. Optical vortex generation with a “fork” hologram under conditions of high-angle diffraction

    Science.gov (United States)

    Bekshaev, A.; Orlinska, O.; Vasnetsov, M.

    2010-05-01

    Spatial characteristics of the optical-vortex (OV) beams created during the Gaussian beam diffraction by a grating with groove bifurcation are analyzed theoretically and numerically. In contrast to previous works, condition of small-angle diffraction is no longer required and the diffracted beam can be strongly deformed. This causes the intensity profile rotation and the high-order OV decomposition into a set of secondary single-charged OVs. These effects are studied quantitatively and confronted with similar properties of a Laguerre-Gaussian beam that undergoes astigmatic telescopic transformation. In contrast to the latter case, the secondary OVs do not lie on a single straight line within the beam cross section, and morphology parameters of the individual secondary OVs carried by the same beam are, in general, different. Conditions for maximum relative separation of the secondary OVs with respect to the beam transverse size are specified. The results can be used for practical generation of OV beams and OV arrays with prescribed properties.

  2. Optimal Angle Reduction - A Behavioral Approach to Linear System Approximation

    NARCIS (Netherlands)

    Roorda, B.; Weiland, S.

    2000-01-01

    We investigate the problem of optimal state reduction under minimization of the angle between system behaviors. The angle is defined in a worst-case sense, as the largest angle that can occur between a system trajectory and its optimal approximation in the reduced order model. This problem is analys

  3. Surgery for an "Acute Erection Angle," When Counseling Fails

    NARCIS (Netherlands)

    Nugteren, Helena M.; Pascal, Astrid L.; Schultz, Willibrord C. M. Weijmar; van Driel, Mels F.

    2010-01-01

    Introduction. During erection, the penis increases in volume, rigidity, and angle. Textbooks of urology and sexology provide only very limited information about erection angle dysfunction. In some men, this angle is too tight toward their belly, causing problems with intercourse. Aim. We reported tw

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

    International Nuclear Information System (INIS)

    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. (electromagnetism, optics, acoustics, heat transfer, classical mechanics, and fluid dynamics)

  5. On large angle multiple gluon radiation

    CERN Document Server

    Dokshitzer, Y L; Dokshitzer, Yu.L.

    2003-01-01

    Jet shape observables which involve measurements restricted to a part of phase space are sensitive to multiplication of soft gluon with large relative angles and give rise to specific single logarithmically enhanced (SL) terms (non-global logs). We consider associated distributions in two variables which combine measurement of a jet shape V in the whole phase space (global) and that of the transverse energy flow away from the jet direction, Eout (non-global). We show that associated distributions factorize into the global distribution in V and a factor that takes into account SL contributions from multi-gluon ``hedgehog'' configurations in all orders. The latter is the same that describes the single-variable Eout distribution, but evaluated at a rescaled energy VQ.

  6. Angle-resolved cathodoluminescence imaging polarimetry

    CERN Document Server

    Osorio, Clara I; Brenny, Benjamin; Polman, Albert; Koenderink, A Femius

    2015-01-01

    Cathodoluminescence spectroscopy (CL) allows characterizing light emission in bulk and nanostructured materials and is a key tool in fields ranging from materials science to nanophotonics. Previously, CL measurements focused on the spectral content and angular distribution of emission, while the polarization was not fully determined. Here we demonstrate a technique to access the full polarization state of the cathodoluminescence emission, that is the Stokes parameters as a function of the emission angle. Using this technique, we measure the emission of metallic bullseye nanostructures and show that the handedness of the structure as well as nanoscale changes in excitation position induce large changes in polarization ellipticity and helicity. Furthermore, by exploiting the ability of polarimetry to distinguish polarized from unpolarized light, we quantify the contributions of different types of coherent and incoherent radiation to the emission of a gold surface, silicon and gallium arsenide bulk semiconductor...

  7. Small angle electron diffraction and deflection

    Directory of Open Access Journals (Sweden)

    T. Koyama

    2012-03-01

    Full Text Available Electron optical system is constructed in order to obtain small angle diffraction and Lorentz deflection of electrons at the order of down to 10-6 radian in the reciprocal space. Long-distance camera length up to 3000 m is achieved in a conventional transmission electron microscope with LaB6 thermal emission type. The diffraction pattern at 5 × 10-6 radian is presented in a carbon replica grating with 500 nm lattice spacing while the magnetic deflection pattern at 2 × 10-5 radian is exhibited in Permalloy elements. A simultaneous recording of electron diffraction and Lorentz deflection is also demonstrated in 180 degree striped magnetic domains of La0.825Sr0.175MnO3.

  8. Wide-angle energy-momentum spectroscopy

    CERN Document Server

    Dodson, Christopher M; Li, Dongfang; Zia, Rashid

    2014-01-01

    Light emission is defined by its distribution in energy, momentum, and polarization. Here, we demonstrate a method that resolves these distributions by means of wide-angle energy-momentum spectroscopy. Specifically, we image the back focal plane of a microscope objective through a Wollaston prism to obtain polarized Fourier-space momentum distributions, and disperse these two-dimensional radiation patterns through an imaging spectrograph without an entrance slit. The resulting measurements represent a convolution of individual radiation patterns at adjacent wavelengths, which can be readily deconvolved using any well-defined basis for light emission. As an illustrative example, we use this technique with the multipole basis to quantify the intrinsic emission rates for electric and magnetic dipole transitions in europium-doped yttrium oxide (Eu$^{3+}$:Y$_{2}$O$_{3}$) and chromium-doped magnesium oxide (Cr$^{3+}$:MgO). Once extracted, these rates allow us to reconstruct the full, polarized, two-dimensional radi...

  9. Foreign Body Embedded in Anterior Chamber Angle

    Directory of Open Access Journals (Sweden)

    Shmuel Graffi

    2012-01-01

    Full Text Available Introduction. We present a case of a metallic foreign body embedded in the anterior chamber angle. After standing in close proximity to a construction worker breaking a tile, a 26-year-old woman using soft contact lens for the correction of mild myopia presented to emergency department for evaluation of a foreign body sensation of her right eye. Methods and Results. Diagnosis was confirmed by gonioscopic examination and a noncontrast CT scan of head and orbits. The foreign body was removed by an external approach without utilizing a magnet. The patient's final outcome was favorable. Discussion. The above is a rare clinical situation, which is impossible to detect on slit-lamp examination without a gonioscopic view. Proper imaging and a specific management are mandatory in order to achieve favorable outcome.

  10. Small-angle scattering in materials science

    International Nuclear Information System (INIS)

    Small-angle scattering (SAS) of X-rays (SAXS) or neutrons (SANS) are a powerful tools to investigate inhomogeneities in the size range from ∼ 1 nm to ∼ 100 nm. Typical examples in materials science are pores, precipitates in metal alloys or nano-particles in composites. Frequently, these inhomogeneities are not spherical and their alignment is not random, quite in contrast to many other applications of SAS. This requires the use of pinhole geometry and area detectors for the experimental set-up. The present paper focuses on evaluation techniques of two-dimensional (2D) SAS-patterns from some materials investigated by the authors, i.e. metal alloys, carbon composites, wood and bone. Although the examples shown are derived exclusively from SAXS measurements, most of them could stem from SANS measurements as well. (author)

  11. Angle-independent structural colors of silicon

    DEFF Research Database (Denmark)

    Højlund-Nielsen, Emil; Weirich, Johannes; Nørregaard, Jesper;

    2014-01-01

    Structural colors are optical phenomena of physical origin, where microscale and nanoscale structures determine the reflected spectrum of light. Artificial structural colors have been realized within recent years. However, multilayer structures require substantial fabrication. Instead we considered...... one-layer surface textures of silicon.We explored four patterns of square structures in a square lattice with periods of 500, 400, 300, and 200 nm. The reflectivity and daylight-colors were measured and compared with simulations based on rigorously coupledwave analysis with excellent agreement. Based...... on the 200-nm periodic pattern, it was found that angle-independent specular colors up to 60 deg of incidence may be provided. The underlying mechanisms include (1) the suppression of diffraction and (2) a strong coupling of light to localized surface states. The strong coupling yields absorption...

  12. Angle-resolved photoemission extended fine structure

    International Nuclear Information System (INIS)

    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

  13. Narrow-angle astrometry with PRIMA

    CERN Document Server

    Sahlmann, J; Mérand, A; Zimmerman, N; Abuter, R; Chazelas, B; Delplancke, F; Henning, T; Kaminski, A; Köhler, R; Launhardt, R; Mohler, M; Pepe, F; Queloz, D; Quirrenbach, A; Reffert, S; Schmid, C; Schuhler, N; Schulze-Hartung, T

    2012-01-01

    The Extrasolar Planet Search with PRIMA project (ESPRI) aims at characterising and detecting extrasolar planets by measuring the host star's reflex motion using the narrow-angle astrometry capability of the PRIMA facility at the Very Large Telescope Interferometer. A first functional demonstration of the astrometric mode was achieved in early 2011. This marked the start of the astrometric commissioning phase with the purpose of characterising the instrument's performance, which ultimately has to be sufficient for exoplanet detection. We show results obtained from the observation of bright visual binary stars, which serve as test objects to determine the instrument's astrometric precision, its accuracy, and the plate scale. Finally, we report on the current status of the ESPRI project, in view of starting its scientific programme.

  14. Secondary maxima in ozone profiles

    OpenAIRE

    R. Lemoine

    2004-01-01

    International audience Ozone profiles from balloon soundings as well as SAGE II ozone profiles were used to detect anomalous large ozone concentrations of ozone in the lower stratosphere. These secondary ozone maxima are found to be the result of differential advection of ozone-poor and ozone-rich air associated with Rossby wave breaking events. The frequency and intensity of secondary ozone maxima and their geographical distribution is presented. The occurrence and amplitude of ozone seco...

  15. Secondary liquefaction in ethanol production

    DEFF Research Database (Denmark)

    2007-01-01

    The invention relates to a method of producing ethanol by fermentation, said method comprising a secondary liquefaction step in the presence of a themostable acid alpha-amylase or, a themostable maltogenic acid alpha-amylase.......The invention relates to a method of producing ethanol by fermentation, said method comprising a secondary liquefaction step in the presence of a themostable acid alpha-amylase or, a themostable maltogenic acid alpha-amylase....

  16. SECONDARY INFECTIONS IN SWINE FLU

    OpenAIRE

    Duthade Mangala; Damle Ajit; Bhakare Jayshree; Bajaj.Jyoti

    2013-01-01

    ABSTRACT: BACKGROUND AND OBJECTIVE : Swine influenza is respiratory disease of pigs ca used by type A influenza virus that causes regular outbr eak in pigs. Human to human transmission occurs. Some people develop severe respiratory symptoms and need ventilator. Patients can get secondary bacterial infections in the form of pneumonia if vi ral infections persist. Death of swine flu occurs d ue to secondary bacterial infections leading to bacter ial pneumonia...

  17. Spondylolysis and the sacro-horizontal angle in athletes

    International Nuclear Information System (INIS)

    The frequency of spondylolysis and the relationship between spondylolysis and the sacro-horizontal angle in 143 athletes and 30 non-athletes is reported. Athletes had a larger sacro-horizontal angle than non-athletes. The sacro-horizontal angle was larger in athletes with spondylolysis as compared with those without. An increased incidence of spondylolysis with an increased angle was demonstrated. It is suggested that an increased sacro-horizontal angle may predispose to spondylolysis, especially in combination with the high mechanical loads sustained in certain sports. (orig.)

  18. Temperature Influence on Divergence Angles of Quartz Crystal Wollaston Prism

    International Nuclear Information System (INIS)

    We propose a structural angle and main refractive indices as two key factors to understand the temperature influence on the divergence angles of the Wollaston prism. The temperature influence on the divergence angles of quartz crystal Wollaston prism is studied theoretically The results show that divergence angles decrease with increasing temperature, while the divergence angle of e-light decrease more quickly than that of o-light. The testing system is established to verify the above results, and the experimental results are in agreement well with the theoretical analysis. (fundamental areas of phenomenology (including applications))

  19. Absolute small-angle measurement based on optical feedback interferometry

    Institute of Scientific and Technical Information of China (English)

    Jingang Zhong; Xianhua Zhang; Zhixiang Ju

    2008-01-01

    We present a simple but effective method for small-angle measurement based on optical feedback inter-ferometry (or laser self-mixing interferometry). The absolute zero angle can be defined at the biggest fringe amplitude point, so this method can also achieve absolute angle measurement. In order to verify the method, we construct an angle measurement system. The Fourier-transform method is used to analysis the interference signal. Rotation angles are experimentally measured with a resolution of 10-6 rad and a measurement range of approximately from -0.0007 to +0.0007 rad.

  20. Impacts of tropical cyclone inflow angle on ocean surface waves

    Institute of Scientific and Technical Information of China (English)

    ZHAO Wei; HONG Xin

    2011-01-01

    The inflow angle of tropical cyclones (TC) is generally neglected in numerical studies of ocean surface waves induced by TC. In this study, the impacts of TC inflow angle on ocean surface waves were investigated using a high-resolution wave model. Six numerical experiments were conducted to examine, in detail, the effects of inflow angle on mean wave parameters and the spectrum of wave directions. A comparison of the waves simulated in these experiments shows that inflow angle significantly modifies TC-induced ocean surface waves. As the inflow angle increases, the asymmetric axis of the significant wave height (SWH) field shifts 30° clockwise, and the maximum SWH moves from the front-right to the rear-right quadrant. Inflow angle also affects other mean wave parameters, especially in the rear-left quadrant, such as the mean wave direction, the mean wavelength, and the peak direction. Inflow angle is a key factor in wave models for the reproduction of double-peak or multi-peak patterns in the spectrum of wave directions. Sensitivity experiments also show that the simulation with a 40° inflow angle is the closest to that of the NOAA statistical SLOSH inflow angle. This suggests that 40° can be used as the inflow angle in future TC-induced ocean surface wave simulations when SLOSH or observed inflow angles are not available.

  1. Angle Kappa and its importance in refractive surgery

    Directory of Open Access Journals (Sweden)

    Majid Moshirfar

    2013-01-01

    Full Text Available 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.

  2. Agreement of angle closure assessments between gonioscopy, anterior segment optical coherence tomography and spectral domain optical coherence tomography

    Institute of Scientific and Technical Information of China (English)

    Elton; Lik; Tong; Tay; Vernon; Khet; Yau; Yong; Boon; Ang; Lim; Stelson; Sia; Elizabeth; Poh; Ying; Wong; Leonard; Wei; Leon; Yip

    2015-01-01

    AIM: To determine angle closure agreements between gonioscopy and anterior segment optical coherence tomography(AS-OCT), as well as gonioscopy and spectral domain OCT(SD-OCT). A secondary objective was to quantify inter-observer agreements of AS-OCT and SD-OCT assessments.METHODS: Seventeen consecutive subjects(33 eyes)were recruited from the study hospital’s Glaucoma clinic.Gonioscopy was performed by a glaucomatologist masked to OCT results. OCT images were read independently by 2 other glaucomatologists masked to gonioscopy findings as well as each other’s analyses of OCT images.RESULTS: Totally 84.8% and 45.5% of scleral spurs were visualized in AS-OCT and SD-OCT images respectively(P <0.01). The agreement for angle closure between AS-OCT and gonioscopy was fair at k =0.31(95% confidence interval, CI: 0.03-0.59) and k =0.35(95%CI: 0.07-0.63) for reader 1 and 2 respectively. The agreement for angle closure between SD-OCT and gonioscopy was fair at k =0.21(95% CI: 0.07-0.49) and slight at k =0.17(95% CI: 0.08-0.42) for reader 1 and 2 respectively. The inter-reader agreement for angle closure in AS-OCT images was moderate at 0.51(95% CI: 0.13-0.88). The inter-reader agreement for angle closure in SD-OCT images was slight at 0.18(95% CI: 0.08-0.45).CONCLUSION: Significant proportion of scleral spurs were not visualised with SD-OCT imaging resulting in weaker inter-reader agreements. Identifying other angle landmarks in SD-OCT images will allow more consistent angle closure assessments. Gonioscopy and OCT imaging do not always agree in angle closure assessments but have their own advantages, and should be used together and not exclusively.

  3. Multi-angle Imaging SpectroRadiometer

    Science.gov (United States)

    Diner, David J. (Principal Investigator)

    MISR views the sunlit Earth simultaneously at nine widely spaced angles and provides ongoing global coverage with high spatial detail. Its imagery is carefully calibrated to provide accurate measures of the brightness, contrast, and color of reflected sunlight. MISR provides new types of information for scientists studying Earth's climate, such as the regional and global distribution of different types of atmospheric particles and aerosols. The change in reflection at different view angles provides the means to distinguish aerosol types, cloud forms, and land surface cover. Combined with stereoscopic techniques, this enables construction of 3-D cloud models and estimation of the total amount of sunlight reflected by Earth's diverse environments. MISR was built for NASA by the Jet Propulsion Laboratory (JPL) in Pasadena, California. It is part of NASA's first Earth Observing System (EOS) spacecraft, the Terra spacecraft, which was launched into polar orbit from Vandenberg Air Force Base on December 18, 1999. MISR has been continuously providing data since February 24, 2000. [Mission Objectives] The MISR instrument acquires systematic multi-angle measurements for global monitoring of top-of-atmosphere and surface albedos and for measuring the shortwave radiative properties of aerosols, clouds, and surface scenes in order to characterize their impact on the Earth's climate. The Earth's climate is constantly changing -- as a consequence of both natural processes and human activities. Scientists care a great deal about even small changes in Earth's climate, since they can affect our comfort and well-being, and possibly our survival. A few years of below-average rainfall, an unusually cold winter, or a change in emissions from a coal-burning power plant, can influence the quality of life of people, plants, and animals in the region involved. The goal of NASA's Earth Observing System (EOS) is to increase our understanding of the climate changes that are occurring on our

  4. Moderate positive spin Hall angle in uranium

    Science.gov (United States)

    Singh, Simranjeet; Anguera, Marta; del Barco, Enrique; Springell, Ross; Miller, Casey W.

    2015-12-01

    We report measurements of spin pumping and the inverse spin Hall effect in Ni80Fe20/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 Ni80Fe20 (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 × 1019 m-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.

  5. Wide-angle tail galaxies in ATLAS

    CERN Document Server

    Mao, Minnie Y; Saikia, D J; Norris, Ray P; Johnston-Hollitt, Melanie; Middelberg, Enno; Lovell, Jim E J

    2010-01-01

    We present radio images of a sample of six Wide-Angle Tail (WAT) radio sources identified in the ATLAS 1.4 GHz radio survey, and new spectroscopic redshifts for four of these sources. These WATs are in the redshift range of 0.1469 - 0.3762, and we find evidence of galaxy overdensities in the vicinity of four of the WATs from either spectroscopic or photometric redshifts. We also present follow-up spectroscopic observations of the area surrounding the largest WAT, S1189, which is at a redshift of ~0.22. The spectroscopic observations, taken using the AAOmega spectrograph on the AAT, show an overdensity of galaxies at this redshift. The galaxies are spread over an unusually large area of ~12 Mpc with a velocity spread of ~4500 km/s. This large-scale structure includes a highly asymmetric FRI radio galaxy and also appears to host a radio relic. It may represent an unrelaxed system with different sub-structures interacting or merging with one another. We discuss the implications of these observations for future l...

  6. LDEF yaw and pitch angle estimates

    Science.gov (United States)

    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.

  7. Moderate positive spin Hall angle in uranium

    Energy Technology Data Exchange (ETDEWEB)

    Singh, Simranjeet; Anguera, Marta; Barco, Enrique del, E-mail: delbarco@ucf.edu, E-mail: cwmsch@rit.edu [Department of Physics, University of Central Florida, Orlando, Florida 32816 (United States); Springell, Ross [H. H. Will Laboratory, University of Bristol, Bristol BS2 8BS (United Kingdom); Miller, Casey W., E-mail: delbarco@ucf.edu, E-mail: cwmsch@rit.edu [School of Chemistry and Materials Science, Rochester Institute of Technology, Rochester, New York 14623 (United States)

    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.

  8. Malocclusion Pattern (Angle's) in Mauritian Orthodontic Patients

    Science.gov (United States)

    Durgesh, B. H.; Prakash, Prashanth; Ramakrishnaiah, Ravikumar; Subashchandra Phulari, Basavaraj; Al Kheraif, Abdul Aziz A.

    2012-01-01

    The aim of the study was to assess the pattern of malocclusion in different ethnic group of Mauritian population visiting the Orthodontic Department at Mauras College of Dentistry and Hospital, Republic of Mauritius. The study population comprised of 624 patients who visited the orthodontic department during 2010. The clinical examination was conducted by a well-calibrated orthodontist. The data were recorded in the case sheets and was analyzed for presence of angles class I, class II, and class III malocclusion in both male and female patients of Asian, African, Caucasian, and Chinese ethnicity aged 5–55 years. Malocclusion was found to be high in females compared to males. 414 patients (150 male + 264 female) presented with class I, 182 patients (52 male + 130 female) presented with class II, and 28 patients (12 male + 16 female) presented with class III. Asian ethnic group were more affected and patient seeking orthodontic treatment was high in 11–15 years age group. PMID:22655203

  9. Impact Angle Control of Interplanetary Shock Geoeffectiveness

    CERN Document Server

    Oliveira, D M

    2015-01-01

    We use OpenGGCM global MHD simulations to study the nightside magnetospheric, magnetotail, and ionospheric responses to interplanetary (IP) fa st forward shocks. Three cases are presented in this study: two inclined oblique shocks, here after IOS-1 and IOS-2, where the latter has a Mach number twice stronger than the former. Both shocks have impact angles of 30$^o$ 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...

  10. Moderate positive spin Hall angle in uranium

    International Nuclear Information System (INIS)

    We report measurements of spin pumping and the inverse spin Hall effect in Ni80Fe20/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 Ni80Fe20 (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 × 1019 m−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

  11. Rubber hand illusion affects joint angle perception.

    Directory of Open Access Journals (Sweden)

    Martin V Butz

    Full Text Available 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.

  12. Mapping of low flip angles in magnetic resonance

    Energy Technology Data Exchange (ETDEWEB)

    Balezeau, Fabien; Saint-Jalmes, Herve [LTSI, INSERM U642, Universite Rennes 1 (France); Eliat, Pierre-Antoine [PRISM, IFR 140, Universite Rennes 1 (France); Cayamo, Alejandro Bordelois, E-mail: fabien.balezeau@gmail.com [Centro De BiofIsika Medica, Universidad de Oriente, Santiago de Cuba (Cuba)

    2011-10-21

    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{sup 0} 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{sup 0} 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{sup 0} to 60{sup 0} with a maximal uncertainty of 10% and to correct T1 maps based on the variable flip angle method.

  13. Study of the advancing and receding contact angles: liquid sorption as a cause of contact angle hysteresis.

    Science.gov (United States)

    Lam, C N C; Wu, R; Li, D; Hair, M L; Neumann, A W

    2002-02-25

    Two types of experiments were used to study the behavior of both advancing and receding contact angles, namely the dynamic one-cycle contact angle (DOCA) and the dynamic cycling contact angle (DCCA) experiments. For the preliminary study, DOCA measurements of different liquids on different solids were performed using an automated axisymmetric drop shape analysis-profile (ADSA-P). From these experimental results, four patterns of receding contact angle were observed: (1) time-dependent receding contact angle; (2) constant receding contact angle; (3) 'stick/slip'; (4) no receding contact angle. For the purpose of illustration, results from four different solid surfaces are shown. These solids are: FC-732-coated surface; poly(methyl methacrylate/n-butyl methacrylate) [P(MMA/nBMA)]; poly(lactic acid) (DL-PLA); and poly(lactic/glycolic acid) 50/50 (DL-PLGA 50/50). Since most of the surfaces in our studies exhibit time dependence in the receding contact angle, a more extended study was conducted using only FC-732-coated surfaces to better understand the possible causes of decreasing receding contact angle and contact angle hysteresis. Contact angle measurements of 21 liquids from two homologous series (i.e. n-alkanes and 1-alcohols) and octamethylcyclotetrasiloxane (OCMTS) on FC-732-coated surfaces were performed. It is apparent that the contact angle hysteresis decreases with the chain length of the liquid. It was found that the receding contact angle equals the advancing angle when the alkane molecules are infinitely large. These results strongly suggest that the chain length and size of the liquid molecule could contribute to contact angle hysteresis phenomena. Furthermore, DCCA measurements of six liquids from the two homologous series on FC-732-coated surfaces were performed. With these experimental results, one can construe that the time dependence of contact angle hysteresis on relatively smooth and homogeneous surfaces is mainly caused by liquid retention

  14. Numerical aperture characteristics of angle-ended plastic optical fiber

    Science.gov (United States)

    Gao, Cheng; Farrell, Gerard

    2003-03-01

    With the increasing information rates demanded in consumer, automotive and aeronautical applications, a low cost and high performance physical transmission medium is required. Compared with Silica Optical Fiber, Plastic Optical Fiber (POF) offers an economic solution for a range of high-capacity, short-haul applications in industrial and military environments. Recently, a new type of POF, the perfluorinated graded-index plastic optical fiber (PF GI-POF), has been introduced that has low losses and high bandwidth at the communication wavelengths 850 nm and 1300nm. POF is normally terminated perpendicular to the fiber axis. We propose an angle-ended POF, which is terminated at non-perpendicular angles to the fiber axis. The aim of the research is to investigate the numerical aperture (NA) characteristics of angle-ended POF along the major axis of the elliptical endface. A theoretical model indicates that the NA of the angle-ended POF will increase nonlinearly with tilt-angle and the acceptance cone will be deflected with the angle of the deflection increasing nonlinearly with tilt-angle. We present results for the measured NA and the measured deflection angle using the far-field radiation method. Results are presented for 13 angle-ended SI-POF tilt-angles. We also present results for theoretical value of NA and deflection angle as a function of tilt-angle. The agreement between the measured and theoretical value is good up to tilt-angles of about 15 degrees, beyond which deviation occurs.

  15. Summarizing primary and secondary effects

    DEFF Research Database (Denmark)

    Karlson, Kristian Bernt

    2013-01-01

    Current methods for decomposing class differentials in educational decisions into primary and secondary effects produce many parameters, rendering them ill-equipped for parsimonious comparisons across countries or birth cohorts. This paper develops a parametric method that provides an optimal...... summary of primary and secondary effects across discrete class origins. Under the testable assumption that the pattern of effects of class origins on academic ability is proportional to the pattern of effects of class origins on educational choice net of academic ability, the method returns a single...... summary measure. Applying the method to two cohorts born in the UK in 1958 and 1970 suggests that––even with increasing overall inequality of educational opportunity––the relative contribution of secondary effects to class differentials in A-level completion has changed little between the two cohorts....

  16. Flexibility of Protein Secondary Structures

    Science.gov (United States)

    Emberly, Eldon; Mukhopadhyay, Ranjan; Tang, Chao; Wingreen, Ned

    2004-03-01

    Proteins consist of compact packings of secondary structural elements: helices and sheets comprised of strands. The deformations of these structures often play an important role in determining the final shape of the protein (i.e. coiled coils or beta-barrels). We have performed a principal component analysis on secondary structural elements extracted from the protein structure database to determine their flexible modes. For helices we find only two dominant internal modes: bend and twist. Sheets also only display two dominant modes: in-sheet bend and a spiral twist. We report on the scaling of these modes with secondary element size. For helices, the dynamic normal modes of a simple spring model are able to recapitulate the modes and scalings found. For sheets, we find different scaling behaviors for parallel and anti-parallel sheets and these differences can not be accounted for using a simple spring model.

  17. [Methylphenidate and secondary Raynaud's phenomenon].

    Science.gov (United States)

    Iglesias Otero, M; Portela Romero, M; Bugarín González, R; Ventura Victoria, M A

    2013-09-01

    Raynaud's phenomenon is a clinical disease characterized by episodic attacks of vasoconstriction of the arteries and arterioles of the extremities such as fingers and toes, sometimes the ears and nose, in response to cold or emotional stimuli. A classic attack is the pallor of the distal extremity, followed by cyanosis and redness, accompanied by paresthesia, usually as heat. When it occurs without apparent cause is called primary Raynaud's phenomenon. When associated with other disease, is called secondary Raynaud's phenomenon. The secondary table is associated with increased frequency of rheumatic diseases of collagen. They can also present certain drugs that cause vasoconstriction, such as ergotamine, beta-adrenergic antagonists, contraception and sympathomimetic drugs. Regarding the latter, we present a case of Raynaud's phenomenon secondary to methylphenidate in a 14 years. PMID:24034762

  18. Removal versus retention of asymptomatic third molars in mandibular angle fractures: a randomized controlled trial.

    Science.gov (United States)

    McNamara, Z; Findlay, G; O'Rourke, P; Batstone, M

    2016-05-01

    The treatment dilemma provided by asymptomatic third molars in mandibular angle fractures remains controversial. This prospective randomized controlled trial was undertaken to determine whether there is an advantage to extraction or retention of the third molar whilst repairing a mandibular angle fracture. Sixty-four patients were allocated randomly to the two treatment groups. All underwent open reduction and internal fixation (ORIF) with standard postoperative care. The primary outcome measure was uncomplicated fracture healing. Secondary measures were surgical duration, malocclusion, wound healing, nerve injury, and return to theatre. All patients had uncomplicated fracture healing. The incidence of nerve injury was 16% for the retention group compared with 39% for the removal group (P=0.038). The average operating time for ORIF and third molar retention cases was 58.5min and for ORIF and third molar removal cases was 66.3min (P=0.26). There was no statistically significant difference between groups for wound healing, occlusion outcomes, or return to theatre. Given the additional risk of nerve injury and the additional operating time required for removal of a third molar, in the absence of an absolute indicator for removal of the third molar, it appears justifiable to advise retaining the tooth in the line of a mandibular angle fracture. PMID:26867667

  19. Improving the Precision and Speed of Euler Angles Computation from Low-Cost Rotation Sensor Data

    Directory of Open Access Journals (Sweden)

    Aleš Janota

    2015-03-01

    Full Text Available This article compares three different algorithms used to compute Euler angles from data obtained by the angular rate sensor (e.g., MEMS gyroscope—the algorithms based on a rotational matrix, on transforming angular velocity to time derivations of the Euler angles and on unit quaternion expressing rotation. Algorithms are compared by their computational efficiency and accuracy of Euler angles estimation. If attitude of the object is computed only from data obtained by the gyroscope, the quaternion-based algorithm seems to be most suitable (having similar accuracy as the matrix-based algorithm, but taking approx. 30% less clock cycles on the 8-bit microcomputer. Integration of the Euler angles’ time derivations has a singularity, therefore is not accurate at full range of object’s attitude. Since the error in every real gyroscope system tends to increase with time due to its offset and thermal drift, we also propose some measures based on compensation by additional sensors (a magnetic compass and accelerometer. Vector data of mentioned secondary sensors has to be transformed into the inertial frame of reference. While transformation of the vector by the matrix is slightly faster than doing the same by quaternion, the compensated sensor system utilizing a matrix-based algorithm can be approximately 10% faster than the system utilizing quaternions (depending on implementation and hardware.

  20. Turkey: Secondary Education and Training. Secondary Education Series.

    Science.gov (United States)

    Fretwell, David H.; Wheeler, Antony

    The World Bank has been assisting the efforts of developing countries to reform secondary education systems for more than 35 years. During this period, the context and imperatives for education reform have changed considerably due to various factors such as globalization of the world economy and the impact of new technologies. This paper is one of…

  1. Secondary organic aerosol formation of primary, secondary and tertiary Amines

    Science.gov (United States)

    Amines have been widely identified in ambient aerosol in both urban and rural environments and they are potential precursors for formation of nitrogen-containing secondary organic aerosols (SOA). However, the role of amines in SOA formation has not been well studied. In this wrok, we use UC-Riversid...

  2. 34 CFR 300.36 - Secondary school.

    Science.gov (United States)

    2010-07-01

    ... 34 Education 2 2010-07-01 2010-07-01 false Secondary school. 300.36 Section 300.36 Education... DISABILITIES General Definitions Used in This Part § 300.36 Secondary school. Secondary school means a nonprofit institutional day or residential school, including a public secondary charter school that...

  3. Pseudoexfoliation syndrome and secondary cataract

    OpenAIRE

    Kuchle, M.; A. Amberg; Martus, P.; Nguyen, N.; NAUMANN, G.

    1997-01-01

    AIM/BACKGROUND—The pseudoexfoliation (PEX) syndrome is frequently associated with impairment of the blood-aqueous barrier. This study analysed if this might stimulate secondary cataract following cataract extraction.
METHODS—This historical cohort study included 197 eyes of 197 patients (99 with and 98 without PEX) that underwent extracapsular cataract extraction with posterior chamber lens implantation (PMMA optic) between 1985 and 1991. Secondary cataract was defined as opacification of the...

  4. Localized lesions in secondary syphillis

    International Nuclear Information System (INIS)

    The clinical manifestations of secondary syphilis are variable and can mimic many skin diseases, mostly being generalized and symmetrical in distribution. Localized lesions of secondary syphilis are rarely seen in dermatology clinics. We report an unusual presentation wherein a patient had localized lesions over face and soles only. There is a need for increased awareness on the part of physicians to recognize new patterns of syphilitic infection, together with a willingness to consider the diagnosis of syphilis in patients with unusual clinical features. (author)

  5. Plain secondary current at water intakes and its effect on sedimentation process

    International Nuclear Information System (INIS)

    The structure of flow at water intake can be considered as three-dimensional and complicated flow structure. To investigate the structure of flow at water intakes, the effect of secondary currents on the sedimentation problem was considered using a physical model. In this study, the characteristic of plain secondary currents was measured experimentally and applied to the problem of the sedimentation process at water intake. The secondary currents were found to be important factor in the sediment transport in the main channel and diversion. The arrangement of vanes at water intake during experimental tests was examined to find the most efficient vane arrangement. It was found that at fixed bed the optimum angle of vane was 20 degree both in parallel and zigzag arrangements. Additionally, the zigzag arrangement was found to produce less strength in secondary currents than parallel. Finally, it was found that the zigzag arrangement reduced sediment ingestion more than parallel. (author)

  6. Contact pressure distribution and support angle optimization of kiln tyre

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    According to the shearing force character and the deformation coordination condition of shell at the station of supports, the mathematical models to calculate contact angle and contact pressure distribution between tyre and shell were set up, the formulae of bending moment and bending stress of tyre were obtained. Taking the maximum of tyre fatigue life as the optimal objective, the optimization model of tyre support angle was built. The computational results show that when tyre support angle is 30°, tyre life is far less than that when tyre support angle is optimal, which is 35.6°, and it is unsuitable to stipulate tyre support angle to be 30° in traditional design. The larger the load, the less the nominal stress amplitude increment of tyre, the more favorable the tyre fatigue life when tyre support angle is optimal.

  7. Elevation angle dependence of the SMA antenna focus position

    CERN Document Server

    Matsushita, S; Sakamoto, K; Hunter, T R; Patel, N A; Sridharan, T K; Wilson, R W; Matsushita, Satoki; Saito, Masao; Sakamoto, Kazushi; Hunter, Todd R.; Patel, Nimesh A.; Sridharan, Tirupati K.; Wilson, Robert W.

    2006-01-01

    We report the measurement results and compensation of the antenna elevation angle dependences of the Sub-millimeter Array (SMA) antenna characteristics. Without optimizing the subreflector (focus) positions as a function of the antenna elevation angle, antenna beam patterns show lopsided sidelobes, and antenna efficiencies show degradations. The sidelobe level increases and the antenna efficiencies decrease about 1% and a few %, respectively, for every 10 degrees change in the elevation angle at the measured frequency of 237 GHz. We therefore obtained the optimized subreflector positions for X (azimuth), Y (elevation), and Z (radio optics) focus axes at various elevation angles for all the eight SMA antennas. The X axis position does not depend on the elevation angle. The Y and Z axes positions depend on the elevation angles, and are well fitted with a simple function for each axis with including a gravity term (cosine and sine of elevation, respectively). In the optimized subreflector positions, the antenna ...

  8. Sunspot group tilt angle measurements from historical observations

    CERN Document Server

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

    2016-01-01

    Sunspot positions from various historical sets of solar drawings are analysed with respect to the tilt angles of bipolar sunspot groups. Data by Scheiner, Hevelius, Staudacher, Zucconi, Schwabe, and Spoerer 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.

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

    Science.gov (United States)

    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

  10. Rotational Angle Measurement of Bridge Support Using Image Processing Techniques

    OpenAIRE

    Young-Soo Park; John Arbie Agbayani; Jong-Han Lee; Jong-Jae Lee

    2016-01-01

    Measuring a very small rotational angle accurately and dynamically is indeed a challenging issue, especially in the case of bridge support. Also, existing inclinometers do not have sufficient resolution and accuracy to measure a bridge’s rotational angle. In this study, a new measurement system was developed to provide a practical means for measuring dynamic rotational angle of a bridge support. It features high resolution and accuracy compared with the available systems on the market. By the...

  11. Orientation angle and the adhesion of single gecko setae

    OpenAIRE

    Hill, Ginel C.; Soto, Daniel R.; Peattie, Anne M.; Full, Robert J.; Kenny, T. W.

    2011-01-01

    We investigated the effects of orientation angle on the adhesion of single gecko setae using dual-axis microelectromechanical systems force sensors to simultaneously detect normal and shear force components. Adhesion was highly sensitive to the pitch angle between the substrate and the seta's stalk. Maximum lateral adhesive force was observed with the stalk parallel to the substrate, and adhesion decreased smoothly with increasing pitch. The roll orientation angle only needed to be roughly co...

  12. Escape angles in bulk chi((2)) soliton interactions

    OpenAIRE

    Johansen, Steffen Kjær; Bang, Ole; Sørensen, Mads Peter

    2002-01-01

    We develop a theory for nonplanar interaction between two identical type I spatial solitons propagating at opposite, but arbitrary transverse angles in quadratic nonlinear (or so-called chi((2))) bulk, media. We predict quantitatively the outwards escape angle, below which the solitons turn around and collide, and above which they continue to move-away from each other. For in-plane interaction, the theory allows prediction of the Outcome of a collision through the inwards escape angle, i.e., ...

  13. Citalopram associated with acute angle-closure glaucoma: case report

    OpenAIRE

    Hassan Sabit; Thirumalai Srinivasa; Croos Robert; Davis Jane

    2005-01-01

    Abstract Background Acute angle-closure glaucoma is a rare complication in patients receiving anti-depressant treatment. In the following case, we report the development of acute angle closure glaucoma in a patient who overdosed on Citalopram, an antidepressant, and discuss the possible etiological mechanisms for the condition. Case presentation We report a 54 year old, Caucasian lady, with depression and alcohol dependence syndrome, who developed acute angle-closure glaucoma after an overdos...

  14. On extracting quark mixing angles in B meson decays

    International Nuclear Information System (INIS)

    After emphasizing the fundamental importance of determining the mixing angles of bottom quarks we list and discuss the considerable systematic uncertainties one faces when extracting these mixing angles from B decays. Evaluating various methods suggested we conclude that a study of the lepton energy spectrum in B decays provides a reasonable way of obtaining the ratio of mixing angles; yet in view of its inherent hazards its results should be backed up by other studies based, e.g., on kaon multiplicities

  15. Tibial and fibular angles in homozygous sickle cell disease

    Energy Technology Data Exchange (ETDEWEB)

    Akamaguna, A.I.; Odita, J.C.; Ugbodaga, C.I.; Okafor, L.A.

    1986-05-01

    Measurements of the tibial and fibular angles made on ankle radiographs of 34 patients with sickle cell disease were compared with those of 36 normal Nigerians. Widening of the fibular angle, which is an indication of tibiotalar slant, was demonstrated in about 79% of sickle cell disease patients. By using fibular angle measurements as an objective method of assessing subtle tibiotalar slant, it is concluded that the incidence of this deformity is much higher among sickle cell disease patients than previously reported. The mean values of tibial and fibular angles in normal Nigerians are higher than has been reported amongst Caucasians.

  16. Tibial and fibular angles in homozygous sickle cell disease

    International Nuclear Information System (INIS)

    Measurements of the tibial and fibular angles made on ankle radiographs of 34 patients with sickle cell disease were compared with those of 36 normal Nigerians. Widening of the fibular angle, which is an indication of tibiotalar slant, was demonstrated in about 79% of sickle cell disease patients. By using fibular angle measurements as an objective method of assessing subtle tibiotalar slant, it is concluded that the incidence of this deformity is much higher among sickle cell disease patients than previously reported. The mean values of tibial and fibular angles in normal Nigerians are higher than has been reported amongst Caucasians. (orig.)

  17. Lateral intermetatarsal angle: a useful measurement of metatarsus primus elevatus?

    Science.gov (United States)

    Bryant, A; Mahoney, B; Tinley, P

    2001-05-01

    The lateral intermetatarsal angle, a measurement of the sagittal plane angular divergence between the dorsal cortices of the first and second metatarsals of lateral weightbearing foot radiographs, was compared in 30 normal and 30 hallux limitus feet. The results suggest that the angle may be measured reliably and that although the measured angles are relatively small, a significant difference exists between the normal and hallux limitus subjects studied. Accordingly, the lateral intermetatarsal angle may prove to be a useful radiographic measurement to assist the podiatric physician in the clinical assessment of hallux limitus. PMID:11359890

  18. Tachometer Derived From Brushless Shaft-Angle Resolver

    Science.gov (United States)

    Howard, David E.; Smith, Dennis A.

    1995-01-01

    Tachometer circuit operates in conjunction with brushless shaft-angle resolver. By performing sequence of straightforward mathematical operations on resolver signals and utilizing simple trigonometric identity, generates voltage proportional to rate of rotation of shaft. One advantage is use of brushless shaft-angle resolver as main source of rate signal: no brushes to wear out, no brush noise, and brushless resolvers have proven robustness. No switching of signals to generate noise. Another advantage, shaft-angle resolver used as shaft-angle sensor, tachometer input obtained without adding another sensor. Present circuit reduces overall size, weight, and cost of tachometer.

  19. Primary expectations of secondary metabolites

    Science.gov (United States)

    Plant secondary metabolites (e.g., phenolics) are important for human health, in addition to the organoleptic properties they impart to fresh and processed foods. Consumer expectations such as appearance, taste, or texture influence their purchasing decisions. Thorough identification of phenolic com...

  20. The secondary metabolite bioinformatics portal

    DEFF Research Database (Denmark)

    Weber, Tilmann; Kim, Hyun Uk

    2016-01-01

    . In this context, this review gives a summary of tools and databases that currently are available to mine, identify and characterize natural product biosynthesis pathways and their producers based on ‘omics data. A web portal called Secondary Metabolite Bioinformatics Portal (SMBP at http...

  1. Secondary limb edemas following irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Tsyb, A.F.; Bardychev, M.S.; Guseva, L.I.

    1981-09-01

    The results of clinical examination and treatment of 96 patients with secondary limb edemas, developed at late periods after radiation therapy of malignant tumors are discussed. The genesis of edema is accounted both for direct radiation injury of lymphatics and blood vessels (veins) and fibrous changes of tissue in irradiated areas.

  2. Secondary limb edemas following irradiation

    International Nuclear Information System (INIS)

    The results of clinical examination and treatment of 96 patients with secondary limb edemas, developed at late periods after radiation therapy of malignant tumors are discussed. The genesis of edema is accounted both for direct radiation injury of lymphatics and blood vessels (veins) and fibrous changes of tissue in irradiated areas. (orig.)

  3. Portugal's Secondary School Modernisation Programme

    Science.gov (United States)

    Heitor, Teresa V.; Freire da Silva, Jose M. R.

    2009-01-01

    The aim of the Secondary School Modernisation Programme, being implemented in Portugal by "Parque Escolar, EPE", is based on the pursuit of quality and makes Portuguese education a potential international benchmark. This paper discusses the strategies adopted to reorganise school spaces. It describes the conceptual model and highlights the…

  4. Secondary syphilis presenting as vertigo

    International Nuclear Information System (INIS)

    Syphilis is a chronic, systemic and sexually transmitted infectious disease affecting most of the organs in the body. A young African man presented with vertigo, unsteadiness of gait and a skin rash suggestive of secondary syphilis. Diagnosis was confirmed on serology and was treated with two shots of long-acting penicillin, following which his symptoms settled. (author)

  5. SECONDARY OSTEOARTHRITIS IN RHEUMATOID ARTHRITIS

    Directory of Open Access Journals (Sweden)

    I. A. Starodubtseva

    2015-01-01

    Full Text Available The paper considers the problems of comorbidities in patients with rheumatoid arthritis (RA. Two or more RA-related conditions were diagnosed according to the results of the QUEST-RA program implemented in 34 countries. Osteoarthritis along with hypertension, hyperlipidemia, and osteoporosis was detected among the most commonly diseases. Owing to expanded diagnostic capabilities, the recognition and treatment of the comorbidities have recently received much attention, as embodied in the draft Association of Rheumatologists of Russia Guidelines for RA management (2014; Part 1. The concept and major characteristics of secondary osteoarthritis in RA are analyzed. It is precisely the inflammatory process and underlying disease-related risk factors, including treatment, that have impact on the development of secondary osteoarthritis and patients’ quality of life as a whole. All this allows an inference about the mechanisms closely intertwined with the underlying disease for the development of secondary osteoarthritis, which initiates cartilage damage and further remodeling. Primary and secondary osteoarthritis was comparatively analyzed. Particular emphasis is placed on current cartilage biomarkers, their diagnostic value and role in monitoring the efficiency of treatment in clinical trials. The paper provides a comparative analysis of detectable serum and urine biomarkers according to the results of the complex analysis made by the National Institutes of Health. Particular attention is given to cartilage oligomeric matrix protein (COMP. Foreign authors’ investigations suggest that there is a relationship between serum COMP levels and disease severity and joint X-ray changes. There is evidence for the efficacy of hyaluronic acid used in the treatment of secondary osteoarthritis in patients with RA. 

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

    Energy Technology Data Exchange (ETDEWEB)

    Hu Tao [Department of Automation, Shanghai University, 149 Yanchang Rd., Shanghai 200072 (China); Shao Zhengyi [Shanghai Astronomical Observatory, Chinese Academy of Sciences, 80 Nandan Rd., Shanghai 200030 (China); Peng Qiuhe, E-mail: thu@shu.edu.cn, E-mail: taohu.nju@gmail.com [Department of Astronomy, Nanjing University, 22 Hankou Rd., Nanjing 210093 (China)

    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.

  7. Secondary glaucoma in CAPN5-associated neovascular inflammatory vitreoretinopathy

    Directory of Open Access Journals (Sweden)

    Cham A

    2016-06-01

    Full Text Available Abdourahman Cham,1,2 Mayank Bansal,3 Himanshu K Banda,4 Young Kwon,1 Paul S Tlucek,1 Alexander G Bassuk,5 Stephen H Tsang,6,7 Warren M Sobol,8 James C Folk,1 Steven Yeh,4 Vinit B Mahajan1,2 1Department of Ophthalmology and Visual Sciences, 2Omics Laboratory, University of Iowa, Iowa City, IA, USA; 3Rajendra Prasad Centre for Ophthalmic Sciences, All India Institute of Medical Sciences, New Delhi, India; 4Department of Ophthalmology, Emory University School of Medicine, Atlanta, GA, 5Department of Pediatrics, University of Iowa, Iowa City, IA, 6Barbara and Donald Jonas Laboratory of Stem Cells and Regenerative Medicine and Bernard and Shirlee Brown Glaucoma Laboratory, Department of Pathology and Cell Biology, Institute of Human Nutrition, College of Physicians and Surgeons, Columbia University, 7Edward S Harkness Eye Institute, New York-Presbyterian Hospital, New York, NY, 8Retina Physicians & Surgeons, Inc., Dayton, OH, USA Objective: The objective of this study was to review the treatment outcomes of patients with secondary glaucoma in cases of autosomal dominant neovascular inflammatory vitreoretinopathy (ADNIV, a hereditary autoimmune uveitis due to mutations in CAPN5. Patients and methods: A retrospective, observational case series was assembled from ADNIV patients with secondary glaucoma. The main outcome measures were intraocular pressure (IOP, visual acuity, use of antiglaucoma medications, ocular surgeries, and adverse outcomes. Perimetry and optic disk optical coherence tomography (OCT were also analyzed. Results: Nine eyes of five ADNIV patients with secondary glaucoma were reviewed. Each received a fluocinolone acetonide (FA implant for the management of posterior uveitis. Following implantation, no eyes developed neovascular glaucoma. Five eyes (in patients 1, 2, and 5 required Ahmed glaucoma valve surgery for the management of steroid-responsive glaucoma. Patient 2 also developed angle closure with iris bombe and underwent laser

  8. Self-sustaining secondary emission in magnetron guns,beam modulation feedbacks

    International Nuclear Information System (INIS)

    This paper reports on computer simulations of an electron cloud formation inside a smooth-bore magnetron.Computer simulations have been performed using 2.5D and 3D electromagnetic PIC code KARAT for the magnetron diode (MD) with parameters close to experimental,and with an external voltage source V0(t) connected to MD via an RL-circuit.The yield of secondary electrons from the cathode takes into account the dependence of the yield on the energy of electrons and the angle between the direction of electron velocity and the perpendicular to the cathode surface,and also the threshold of secondary emission

  9. Optimal Design of a Secondary Optical Element for a Noncoplanar Two-Reflector Solar Concentrator

    Directory of Open Access Journals (Sweden)

    Yi-Cheng Chen

    2015-01-01

    Full Text Available This paper presents the results of a parametric design process used to achieve an optimal secondary optical element (SOE in a noncoplanar solar concentrator composed of two reflectors. The noncoplanar solar concentrator comprises a primary parabolic mirror (M1 and a secondary hyperbolic mirror (M2. The optical performance (i.e., acceptance angle, optical efficiency, and irradiance distribution of concentrators with various SOEs was compared using ray-tracing simulation. The parametric design process for the SOE was divided into two phases, and an optimal SOE was obtained. The sensitivity to assembly errors of the solar concentrator when using the optimal SOE was studied and the findings are discussed.

  10. Virtuts castrenses de l'angle recte

    Directory of Open Access Journals (Sweden)

    Antonio Bustamante

    2003-01-01

    Full Text Available Está muy arraigada la idea de que, en una postura sedente sana, los segmentos corporales han de orientarse en ángulo recto. La desinformación que encierra esta idea es demasiado evidente y puede parecer fácil, a primera vista, retirar de la circulación esta paradójica receta; pero no es así. La pertinaz veneración de lo ortogonal que, en lo postural, se encuentra por doquier, ha hecho sospechar al autor que la fuerza de los 90° no se debe a errores de apreciación biomecánica, sino a simbologías cuyo origen, si no se pierde en la noche de los tiempos, sí que aparece en la aurora del Neolítico. Este artículo trata de mostrar que si lo ortogonal está justificado por la cultura para la construcción de objetos, no lo está para la adopción de posturas sedentes. _____________________________________________________________________________________________________________________________________________________________________ L’idée est profondément ancrée dans les esprits que dans une position assise correcte les segments corporaux doivent former entre eux une série d’angles droits. L’ignorance qui se cache derrière cette conception semble à priori trop évidente et devrait être facile à combattre, or tel n’est pas le cas. La vénération persistante de la position orthogonale est si étendue qu’elle a amené l’auteur à soupçonner que le culte des 90 degrés n’est pas dû à des erreurs d’appréciation biomécaniques mais à une forte symbologie dont les origines si elles ne remontent pas à la nuit des temps, renvoient au moins à l’aube du Néolithique. L’article essaie de démontrer que si la position orthogonale est culturellement justifiée pour la fabrication d’objets elle ne l’est pas de façon systématique pour ce qui de s’asseoir.The idea is well-rooted that in a healthy sitting position the segments of the body have to adopt a right angle. The disinformation surrounding this idea is

  11. Non-pupillary block angle-closure mechanisms: a comprehensive analysis of their prevalence and treatment outcomes

    Directory of Open Access Journals (Sweden)

    Daniela L. M. Junqueira

    2014-12-01

    Full Text Available Purpose: To assess the prevalence and treatment outcomes of angle-closure mechanisms other than pupillary block in a population of Brazilian patients. Methods: A retrospective chart review was conducted to evaluate patients who had undergone laser peripheral iridotomy (LPI due to occludable angles at a single institution between July 2009 and April 2012. An occludable angle was defined as an eye in which the posterior trabecular meshwork was not visible for ≥180° on dark-room gonioscopy. Key exclusion criteria were any form of secondary glaucoma and the presence of >90° of peripheral anterior synechiae. Collected data were age, race, gender, angle-closure mechanism (based on indentation goniocopy and ultrasound biomicroscopy, intraocular pressure (IOP, number of antiglaucoma medications and subsequent management during follow-up. If both eyes were eligible, the right eye was arbitrarily selected for analysis. Results: A total of 196 eyes of 196 consecutive patients (mean age 58.3 ± 11.6 years who underwent LPI were included. In most of the patients [86% (169 patients; 133 women and 36 men], LPI sucessfully opened the angle. Mean IOP was reduced from 18.3 ± 6.4 mmHg to 15.4 ± 4.5 mmHg after LPI (p<0.01. Among the 27 patients with persistent occludable angles, the most common underlying mechanisms were plateau iris (56% and lens-induced component (34%. Most of these patients (85% were treated with argon laser peripheral iridoplasty (ALPI; approximately 90% showed non-occludable angles following the laser procedure (mean IOP reduction of 18.9%, with no significant differences between patients with plateau iris and lens-induced components (p=0.34; mean follow-up of 11.4 ± 3.6 months. Conclusion: Our findings suggest that, in this population of Brazilian patients, several eyes with angle closure were not completely treated with LPI. In the present large case series involving middle-age patients, plateau iris was the leading cause of

  12. 46 CFR 58.01-40 - Machinery, angles of inclination.

    Science.gov (United States)

    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...

  13. Bite angle effects of diphosphines in carbonylation reactions

    NARCIS (Netherlands)

    P.W.N.M. van Leeuwen; Z. Freixa

    2008-01-01

    This chapter contains sections titled: * Introduction * Rhodium-Catalyzed Hydroformylation o Introduction o Steric Bite Angle Effect and Regioselectivity o Electronic Bite Angle Effect and Activity o Isotope Effects [24] * Platinum-Catalyzed Alkene Hydroformylation * Palladium-Catalyzed CO/Ethene Co

  14. Escape angles in bulk chi((2)) soliton interactions

    DEFF Research Database (Denmark)

    Johansen, Steffen Kjær; Bang, Ole; Sørensen, Mads Peter

    2002-01-01

    We develop a theory for nonplanar interaction between two identical type I spatial solitons propagating at opposite, but arbitrary transverse angles in quadratic nonlinear (or so-called chi((2))) bulk, media. We predict quantitatively the outwards escape angle, below which the solitons turn aroun...

  15. EVALUATION OF NECK SHAFT ANGLE OF FEMUR ON DRY BONES

    Directory of Open Access Journals (Sweden)

    Radha

    2015-04-01

    Full Text Available BACKGROUND: Evaluation of the neck shaft angle of femur helps to understand clinical relevance in bio mechanics of the hip joint. It helps for the better treatment of different pathological conditions of hip and femur and also to design prosthesis. Femoral neck shaft angle is important to convey the information regarding the race to which they belong. Hence the present study was under taken to determine the neck shaft angle of femur in humans. OBJECTIVE: 1. To correct the different types of deformity and to have a normal good walking Mechanism. 2. To know the recent methodology and attempt to evaluate the range of normal Angles of femora and their sex differences. METHODS: ANTHROPOMETRIC: 100 Adult dry bones were studied and analyzed . The neck shaft angle of femur was measured by tracing outlines of contours of all femora. RESULTS: The neck shaft angle of the femur have revealed that there is no much difference in between males and females. There was slightly higher 0.2° in females. INTERPRETATION & CONCLUSION: There was no significant gender difference in neck shaft angle. The Knowledge of knowing the neck shaft angle helps to understand the Biomechanics of the hip joint and also for better treatment of pathological condition of hip and femur.

  16. Note on four Dp-branes at angles

    International Nuclear Information System (INIS)

    In this note we analyse the dynamical potential of a system of four Dp-branes at arbitrary angles. The equilibrium configurations for various values of the relative angles and distances among branes are discussed. The known configurations of parallel branes and brane-antibranes are obtained at extrema of the dynamical potential. (author)

  17. Note on Four Dp-Branes at Angles

    Science.gov (United States)

    Vancea, Ion-Vasile

    2001-04-01

    In this note we analyse the dynamical potential of a system of four Dp-branes at arbitrary angles. The equilibrium configurations for various values of the relative angles and distances among branes are discussed. The known configurations of parallel branes and brane-antibranes are obtained at extrema of the dynamical potential.

  18. Note on Four Dp-Branes at Angles

    OpenAIRE

    Vancea, Ion V.

    2000-01-01

    In this note we analyse the dynamical potential of a system of four $Dp$-branes at arbitrary angles. The equilibrium configurations for various values of the relative angles and distances among branes are discussed. The known configurations of parallel branes and brane-antibranes are obtained at extrema of the dynamical potential.

  19. The effective take-off angle in PHI Quantera systems

    NARCIS (Netherlands)

    Van der Marel, C.

    2010-01-01

    It is well known that for quantitative analysis of XPS results theeffective take-off angle of the electrons is an important parameter.In the report is shown that the effective take-off angle i n PHI Quantera systems deviates significanlty from the set value. This is NOT a consequence of inadequa

  20. A Novel Monopulse Angle Estimation Method for Wideband LFM Radars

    Directory of Open Access Journals (Sweden)

    Yi-Xiong Zhang

    2016-06-01

    Full Text Available 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.

  1. A Novel Monopulse Angle Estimation Method for Wideband LFM Radars.

    Science.gov (United States)

    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

  2. Brocard angle of the standard triangle in an isotropic plane

    OpenAIRE

    Kolar-Begović, Zdenka; Kolar - Šuper, Ružica; Volenec, Vladimir

    2009-01-01

    The concept of Brocard angle of the standard triangle in an isotropic plane I2 is introduced. The relationships between Brocard angles of the allowable triangle and circum-Ceva’s triangle of its centroid and circum-Ceva’s triangle of its Feuerbach point are investigated.

  3. A gallery approach for off-angle iris recognition

    Science.gov (United States)

    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.

  4. A new uncertainty relation for angular momentum and angle

    International Nuclear Information System (INIS)

    An uncertainty relation of the form ΔL2ΔSo >=sup(h/2π)/sub(2) is derived for angular momentum and angle. The non-linear operator So measures angles and has a simple interpretation. Subject to very general conditions of rotational invariance the above relation is unique. Radial momentum is not quantized

  5. EVALUATION OF NECK SHAFT ANGLE OF FEMUR ON DRY BONES

    OpenAIRE

    Radha; Ravi Shankar; Naveen; Roopa

    2015-01-01

    BACKGROUND: Evaluation of the neck shaft angle of femur helps to understand clinical relevance in bio mechanics of the hip joint. It helps for the better treatment of different pathological conditions of hip and femur and also to design prosthesis. Femoral neck shaft angle is important to convey the information regarding the race to ...

  6. Low angle neutron data acquisition system for molecular biology

    International Nuclear Information System (INIS)

    The low angle spectrometer system utilizing a 2-dimensional position sensitive counter was designed to accommodate a variety of experiments in molecular biology requiring good low angle resolution. Biological structures requiring low angle analysis techniques fall into two groups: non-ordered systems (proteins or protein complexes in solution) and ordered systems with large spacings like muscle, collagen, and membranes. For structural investigations into such systems, data are ideally needed to a low scattering angle of 0.20 at 4.5 A or a minimum Q of 0.005 A-1 (Q = theta . 2π/lambda). Depending on the type of structure, data often extend to the high angle region, say 300. Apart from the low angle requirements, the spectrometer has to have good resolution to resolve diffraction peaks from samples with crystal spacings up to 1000 A or even larger. While it is desirable to build a spectrometer to such scattering conditions, given reactor conditions might not permit this and compromises have to be made between flux, resolution and lowest angle. The low angle spectrometer described here was designed to be used at the HFBR neutron beam pipe working at approximately 4.2 A or at the H4 satellite station working at 2.4 A

  7. The effect of knee joint angle on torque control.

    Science.gov (United States)

    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. PMID:19906637

  8. Contact angles in the pseudopotential lattice Boltzmann modeling of wetting

    CERN Document Server

    Li, Q; Kang, Q J; Chen, Q

    2014-01-01

    In this paper, we aim to investigate the implementation of contact angles in the pseudopotential lattice Boltzmann modeling of wetting at a large density ratio. The pseudopotential lattice Boltzmann model [X. Shan and H. Chen, Phys. Rev. E 49, 2941 (1994)] is a popular mesoscopic model for simulating multiphase flows and interfacial dynamics. In this model, the contact angle is usually realized by a fluid-solid interaction. Two widely used fluid-solid interactions: the density-based interaction and the pseudopotential-based interaction, as well as a modified pseudopotential-based interaction formulated in the present paper, are numerically investigated and compared in terms of the achievable contact angles, the maximum and the minimum densities, and the spurious currents. It is found that the pseudopotential-based interaction works well for simulating small static (liquid) contact angles, however, is unable to reproduce static contact angles close to 180 degrees. Meanwhile, it is found that the proposed modif...

  9. Stable divergence angles of a magnetic dipole spiral array

    Energy Technology Data Exchange (ETDEWEB)

    Fan, X.D.; Bursill, L.A.

    1996-03-01

    An analytical model is introduced for Douady and Couder`s [1992] experiment, where phyllotactic patterns appear as a dynamical result of the interaction between magnetic dipoles. The difference equation for the divergence angle (i.e. the angle between successive radial vectors) is obtained by solving the equations of motion with a second nearest neighbour (SNN) approximation. A one dimensional map analysis as well as a comprehensive analytical proof shows that the divergence angle always converges to a single attractor regardless of the initial conditions. This attractor is approximately the Fibonacci angle ({approx} 138 deg) within variations due to a growth factor {mu} of the pattern. The system is proved to be stable with the SNN approximation. Further analysis with a third nearest neighbour approximation (TNN) shows extra linearly stable attractors may appear around the Lucas angle at {approx} 99.5 deg. 7 refs., 5 figs.

  10. [The sulcus angle of the femoral trochlea: ultrasonographic evaluation].

    Science.gov (United States)

    Martino, F; De Serio, A; Macarini, L; Colaianni, P; Solarino, M; Fracella, M R

    1995-03-01

    The sulcus angle of femoral trochlea is particularly important to evaluate the femoro-patellar joint. Our study was aimed at studying the normal trochlea, and especially the sulcus angle, with US. The right knees of 11 normal subjects were examined with US and Computed Tomography (CT) on the same section planes. The US measurements of the sulcus angle were correlated with CT results, which were considered the gold standard. The US and CT data were compared and a direct correlation was found (r = 0.832). The intraobserver difference in US measurements was r = 0.943. The mean sulcus angle value was 132 degrees, in agreement with literature data. We conclude that the US measurements of the sulcus angle are reproducible and as sensitive as CT. PMID:7754110

  11. New mixing angles in the left-right symmetric model

    Science.gov (United States)

    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'.

  12. Tracking multiple generation and suppression of secondary electrons on periodic triangular surface

    International Nuclear Information System (INIS)

    To research the dynamic course of multipactor suppression on the periodically patterned surface, tens of electron collision processes are tracked by numerical calculation. The influences of microwave frequency, amplitude of RF electric field, slope angle, the local field enhancement, and the tilted incident electric field on the multipactor suppression are studied by tracking multi-generation electrons' trajectories, hopping and flight time, collision energy, and secondary emission yield. Meanwhile, the dynamic processes of secondary electrons on the periodic surface are analyzed by particle-in-cell (PIC) simulation. The PIC results are consistent with the analytical results in which the electrons fly reciprocatingly between the slopes and impact on the slopes; the methods of increasing the slope angle, enlarging the RF field, and lowering the frequency in a certain range are helpful to enhance the multipactor suppression steadily and persistently

  13. Demarcation of secondary hyperalgesia zones

    DEFF Research Database (Denmark)

    Ringsted, Thomas K; Enghuus, Casper; Petersen, Morten A; Werner, Mads U

    2015-01-01

    of analgesic drug effects in humans. However, since the methods applied in demarcating the secondary hyperalgesia zone seem inconsistent across studies, we examined the effect of a standardized approach upon the measurement of SHA following a first degree burn injury (BI). NEW METHOD: The study was a...... SHAs (P<0.0001). No day-to-day or observer-to-observer differences in SHAs were observed. Intraclass correlation coefficients, in the range of 0.51 to 0.84, indicated a moderate to almost perfect reliability between observers. COMPARISON WITH EXISTING METHODS: No standardized approach in SHA......-assessment has hitherto been presented. CONCLUSIONS: This is the first study to demonstrate that demarcation of secondary hyperalgesia zones depends on the developed pressure of the punctate stimulator used....

  14. Building a secondary containment system

    Energy Technology Data Exchange (ETDEWEB)

    Broder, M.F.

    1994-10-01

    Retail fertilizer and pesticide dealers across the United States are installing secondary containment at their facilities or are seriously considering it. Much of this work is in response to new state regulations; however, many dealers not facing new regulations are upgrading their facilities to reduce their liability, lower their insurance costs, or comply with anticipated regulations. The Tennessee Valley Authority`s (TVA) National Fertilizer and Environmental Research Center (NFERC) has assisted dealers in 22 states in retrofitting containment to their facilities. Simultaneous improvements in the operational efficiency of the facilities have been achieved at many of the sites. This paper is based on experience gained in that work and details the rationale used in planning secondary containment and facility modifications.

  15. Secondary lead production in Malaysia

    Science.gov (United States)

    Phillips, M. J.; Lim, S. S.

    The increase in the number of vehicles and, subsequently, the volume of batteries made by manufacturers in Malaysia have seen a dramatic rise in lead demand over the last five years. Without any lead mines, the only source of lead in Malaysia has been from the recycling of lead/acid batteries. Metal Reclamation (Industries) has commenced the design of a new and advanced secondary lead plant at West Port, Malaysia to meet the increasing demand for lead and the increasingly stringent environmental regulations. The plant is designed to produce up to 75 000 t of lead and lead alloys per year. The plant will also produce, as by-products: polypropylene chips, wallboard-grade gypsum, non-leachable slag for use in construction. A discussion of the process and the products from the new secondary smelter is outlined.

  16. Scintillation detector of secondary electrons

    International Nuclear Information System (INIS)

    The detector is based on powder or single crystal scintillators and is formed by a scintillator shaped as a cone, a truncated cone or a flat disk plate. The scintillator is accommodated in the cylindrical cage of the detector under the level of the cage's front, and is attached to the front of a light guide which is coaxially aligned in the cylindrical detector cage. To increase the collecting efficiency for secondary electrons impinging on the scintillator, an electron-optical diaphragm with a positive voltage is positioned in the detector cage and screened by means of a screening tube with a ground potential. This diaphragm also contributes to secondary electron focusing to the scintillator centre. (Z.S). 2 figs

  17. Secondary Metabolites from Rubiaceae Species

    OpenAIRE

    Daiane Martins; Cecilia Veronica Nunez

    2015-01-01

    This study describes some characteristics of the Rubiaceae family pertaining to the occurrence and distribution of secondary metabolites in the main genera of this family. It reports the review of phytochemical studies addressing all species of Rubiaceae, published between 1990 and 2014. Iridoids, anthraquinones, triterpenes, indole alkaloids as well as other varying alkaloid subclasses, have shown to be the most common. These compounds have been mostly isolated from the genera Uncaria, Psych...

  18. Secondary middle turbinate: case report

    Energy Technology Data Exchange (ETDEWEB)

    Aburjeli, Bruna de Oliveira Melim; Avila, Ana Flavia Assis de; Diniz, Renata Lopes Furletti Caldeira; Motta, Emilia Guerra Pinto Coelho; Ribeiro, Marcelo Almeida; Moreira, Wanderval, E-mail: bruninha86@hotmail.com [Radiology and Imaging Diagnosis, Hospital Mater Dei, Belo Horizonte, MG (Brazil)

    2012-11-15

    Secondary middle turbinate is an anatomical variant rarely observed in the nasal cavity, firstly described by Khanobthamchai et al. as a bone structure originating from the lateral nasal wall and covered by soft tissue. In most cases reported in the literature, this variant is bilateral, occurring without associated complications. In the present report, the authors describe the case of patient of their institution with such anatomical variation. (author)

  19. Sinonasal schwannoma with secondary changes

    OpenAIRE

    Somasekhar; S.Lakshmi; S. Ramya

    2008-01-01

    Schwannomas of the Sinonasal tract are very rare, representing less than 4% of schwannomas arising in the head and neck [1]. The most frequent site is the acoustic nerve; other locations include the scalp, oral cavity, pharynx, larynx, trachea, parotid gland, and middle ear. Secondary changes in a Schwannoma are a very rare entity. We report a case of Sinonasal schwannoma with pseudoangiomatous changes. The purpose of this article is to highlight the possibility of unusual presentation of a s...

  20. Monoparesis secondary to herpes zoster.

    LENUS (Irish Health Repository)

    Bilal, S

    2011-06-01

    We describe a 90-year-old woman with right upper limb monoparesis secondary to varicella zoster virus infection as a result of extensive inflammatory involvement of the entire brachial plexus at root level. To our knowledge, this is the first report of entire brachial plexus involvement in a living patient of such advanced age. Despite a delay in presentation and thus initiation of treatment, a favourable clinical response was observed.

  1. Chemistry of the secondary circuit

    International Nuclear Information System (INIS)

    Study of the various possibilities to prevent the corrosion phenomena in the different parts of the secondary circuit (condenser, water facility, steam lines, turbines and vapor generators): choice of a volatile conditioning with ammonia or morpholine and not with phosphate which concentration in the vapor generators may induce local corrosion, and search for a low oxidizing medium by restriction of the air admission and addition of hydrazine

  2. [Double measurement of the Böhler angle: prognostic value of radiological angles in posterior facet fractures of the calcaneus].

    Science.gov (United States)

    Chaminade, B; Zographos, S; Uthéza, G

    2001-11-01

    In 1931, Böhler proposed that measuring the radiological angle of the tuberosity could be useful in posterior facet fractures of the calcaneus to evaluate initial damage as well as reduction quality. In opposition to the 1998 SOFCOT symposium, certain authors considered that the Böhler angle has no prognostic value. Progress in pathological anatomy has helped to better understand posterior facet fractures, justifying the use of a "double measurement". The fundamental fracture line separates the posterior facet into a lowered medial fragment and a pivoted lateral fragment. The double contour of the posterior facet visualized radiographically allows measurement of a medial Böhler angle and a lateral Böhler angle. It is demonstrated that is the smaller the medial Böhler angle, the greater the subtalar degeneration. Surgical restoration of a satisfactory Böhler angle is a necessary prerequisite for a good outcome. "Double measurement" of the Böhler angle on the lateral view contributes to the prognostic value of this historical angle. PMID:11845075

  3. EFFECT OF SWEEP ANGLE ON THE VORTICAL FLOW OVER DELTA WINGS AT AN ANGLE OF ATTACK OF 10°

    Directory of Open Access Journals (Sweden)

    JAMES BRETT

    2014-12-01

    Full Text Available CFD simulations have been used to analyse the vortical flows over sharp edged delta wings with differing sweep angles under subsonic conditions at an angle of attack of 10°. RANS simulations were validated against experimental data for a 65° sweep wing, with a flat cross-section, and the steadiness of the flow field was assessed by comparing the results against unsteady URANS and DES simulations. To assess the effect of sweep angle on the flow field, a range of sweep angles from 65° to 43° were simulated. For moderate sweep wings the primary vortex was observed to detach from the leading edge, undergoing vortex breakdown, and a weaker, replacement, "shadow" vortex was formed. The shadow vortex was observed for sweep angles of 50° and less, and resulted in reduced lift production near the wing tips loss of the stronger primary vortex.

  4. Complex modification of secondary silumins

    Directory of Open Access Journals (Sweden)

    A. A. Mityayev

    2014-12-01

    Full Text Available Purpose. Development of scientific and technological bases of formation of the specified secondary hypoeutectic (АK8M3 and eutectic (АК12М2MgН silumins' structure; and increasing their mechanical and service properties' indices in the cast state and after heat treatment up to the level of primary alloys. Methodology. Determination of the chemical composition was conducted by spectral analysis on the spark spectrometer «SPECTROLAB» (Germany. Metallographic analysis was performed on the microscopes МIМ-7 and МIМ-8, and also by the high definition metallography method using the raster electronic microscope «JSMT-300» (Japan. Heat treatment of aluminum alloys was carried out applying T1 and T5 modes according to State Standard of Ukraine 2839-94 (GOST 1583-93. Standard techniques were used during the determination of mechanical properties. The temperature coefficient of linear expansion for the piston alloy АK12М2МgH (AL25 was determined using the specimens Ø with the diameter of 3.5 mm and length of 50 mm with the use of Shevenard optical quartz dilatometer. High temperature fracture resistance was determined according to State Standard 10145-81 as the time before fracture of the specimen at specified stress of 50 MPa and temperature of 300°С. Findings. The technology of obtaining alloys from charge, which consists of 100 % scrap and production wastes has been developed and implemented into production. This technology provides obtaining of metal of the guaranteed chemical composition and high quality with the reduction of energy costs for melting. Originality. The regularities of the formation of the structural and phase state and the level of physical and mechanical properties of eutectic and secondary hypoeutectic silumins depending on the refining and modifying processes have been established. The generalization of regularities of the secondary silumins' fracture has been carried out. Quantitative characteristics of the

  5. The range of options for handling plane angle and solid angle within a system of units

    Science.gov (United States)

    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.

  6. Secondary Analysis for Results Tracking Database

    Data.gov (United States)

    US Agency for International Development — The Secondary Analysis and Results Tracking (SART) activity provides support for the development of two databases to manage secondary and third-party data, data...

  7. Going round the bend: Persistent personal biases in walked angles.

    Science.gov (United States)

    Jetzschke, Simon; Ernst, Marc O; Moscatelli, Alessandro; Boeddeker, Norbert

    2016-03-23

    For navigation through our environment, we can rely on information from various modalities, such as vision and audition. This information enables us for example to estimate our position relative to the starting position, or to integrate velocity and acceleration signals from the vestibular organ and proprioception to estimate the displacement due to self-motion. To better understand the mechanisms that underlie human navigation we analysed the performance of participants in an angle-walking task in the absence of visual and auditory signals. To this end, we guided them along paths of different lengths and asked them to turn by an angle of ±90°. We found significant biases in turn angles, i.e. systematic deviations from the correct angle and that these were characteristic for individual participants. Varying path length, however, had little effect on turn accuracy and precision. To check whether this idiosyncrasy was persistent over time and present in another type of walking task, we performed a second experiment several weeks later. Here, the same participants were guided to walk angles with varying amplitude. We then asked them to judge whether they had walked an angle larger or smaller than 90° in a two-alternative forced-choice paradigm. The personal bias was highly correlated between the two experiments even though they were conducted weeks apart. The presence of a persistent bias in walked angles in the absence of external directional cues indicates a possible error component for navigation, which is surprisingly time stable and idiosyncratic. PMID:26854843

  8. Geometric relation for neutrino mixing angles and theta(13)

    CERN Document Server

    Lipmanov, E M

    2011-01-01

    Inspired by the recent T2K discovery of a relatively large theta(13) angle in the neutrino mixing matrix we propose here a simple geometric relation between the three usually thought "independent" neutrino mixing angles - solar {\\theta}12, atmospheric {\\theta}23 and reactor {\\theta}13 ones: cos2(2{\\theta}sol) + cos2(2{\\theta}atm) + cos2(2{\\theta}13) = 1. Using the estimations for the two largest neutrino mixing angles from experimental data analyses in the literature, {\\theta}sol{\\cong} ~ 34.4o, {\\theta}atm{\\cong} ~ 42.8o, the reactor neutrino mixing angle is uniquely predicted {\\theta}13 = 10.8o. In case a little changed data, {\\theta}sol{\\cong} = 34o and {\\theta}atm{\\cong} = 43o the result will be {\\theta}13 =11.2o. And so, the {\\theta}13-value is not very sensitive to the accurate magnitudes of the two largest mixing angles. That prediction for the 'small' neutrino mixing angle is compatible with the latest T2K experimental data with best fit values for the reactor angle ({\\theta}13)bf{\\cong}= 9.7o(11o) fo...

  9. RESEARCH OF BASIFACIAL CONTOURING SCULPTURE BY MANDIBULAR ANGLE OSTECTOMY

    Institute of Scientific and Technical Information of China (English)

    FANG Jian-lin; DAI Chuan-chang; ZHU Guo-xian; ZHANG Ying; JIN Yu-qing; WANG Wei; QI Chuan-liang

    2006-01-01

    Objective Mandibular angle ostectomy is usually applied to the facial contouring sculpture.We evaluated the various techniques in order to enhance the precision and avoid unnecessary damage. Methods Before operation the area and quantity resected bone were designed according to facial measurement, mandible pantomography and orthophoria and lateral localized radiograph of skull. The Incises of mandibular angle ostectomy included intraoral, retroauricular or intraoral associated with retroauricular. Howerer, the sagittal resection of mandible outer table was necessary in all intraoral incise. Results Single mandibular angle ostectomy was not satisfactory for the patients having mandible hypertrophy with over-width basifacial contouring. Mandibular angle ostectomy combined with the sagittal resection of outer table of mandibular angle were required. Good symmetry and ap pearance were gained in 206 cases. One case had facial paralysis. Two patients occured mandibular fracture during the operation. Three cases complicated angled deformity at mandible body. Conclusion Reduction mandibuloplasty should be selected depends on varied types of mandibular angle hypertrophy before operation.

  10. Viewing angle switching of patterned vertical alignment liquid crystal display

    International Nuclear Information System (INIS)

    Viewing angle control of a patterned vertical alignment (PVA) liquid crystal display using only one panel is investigated. In conventional PVA modes, a vertically aligned liquid crystal (LC) director tilts down in four directions making 45 deg. with respect to crossed polarizers to exhibit a wide viewing angle. In the viewing angle control device, one pixel was divided into two sub-pixels such that the LC director in the main pixel is controlled to be tilted down in multiple directions making an angle with the polarizer, playing the role of main display with the wide viewing angle, while the LC director in the sub-pixel is controlled to be tilted down to the polarizer axis, playing the role of sub-pixel to the viewing angle control for the narrow viewing angle. Using sub-pixel control, light leakage or any type of information such as characters and image can be generated in oblique viewing directions without distorting the image quality in the normal direction, which will prevent others from peeping at the displayed image by overlapping the displayed image with the made image

  11. Operational multi-angle hyperspectral remote sensing for feature detection

    Science.gov (United States)

    Bostater, Charles R.; Brooks, Donald K.

    2013-10-01

    Remote sensing results of land and water surfaces from airborne and satellite platforms are dependent upon the illumination geometry and the sensor viewing geometry. Correction of pushbroom hyperspectral imagery can be achieved using bidirectional reflectance factors (BRF's) image features based upon their multi-angle hyperspectral signatures. Ground validation of features and targets utilize non-imaging sensors such as hemispherical goniometers. In this paper, a new linear translation based hyperspectral imaging goniometer system is described. Imagery and hyperspectral signatures obtained from a rotation stage platform and the new linear non-hemispherical goniometer system shows applications and a multi-angle correction approach for multi-angle hyperspectral pushbroom imagery corrections. Results are presented in a manner in order to describe how ground, vessel and airborne based multi-angle hyperspectral signatures can be applied to operational hyperspectral image acquisition by the calculation of hyperspectral anisotropic signature imagery. The results demonstrate the analysis framework from the systems to water and coastal vegetation for exploitation of surface and subsurface feature or target detection based using the multi-angle radiative transfer based BRF's. The hyperspectral pushbroom multi-angle analysis methodology forms a basis for future multi-sensor based multi-angle change detection algorithms.

  12. Dynamic angle selection in X-ray computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Dabravolski, Andrei, E-mail: andrei.dabravolski@uantwerpen.be [iMinds-Vision Lab, University of Antwerp, Universiteitsplein 1, 2610 Wilrijk (Belgium); Batenburg, Kees Joost, E-mail: joost.batenburg@uantwerpen.be [iMinds-Vision Lab, University of Antwerp, Universiteitsplein 1, 2610 Wilrijk (Belgium); Centrum Wiskunde and Informatica (CWI), Science Park 123, 1098 XG Amsterdam (Netherlands); Sijbers, Jan, E-mail: jan.sijbers@uantwerpen.be [iMinds-Vision Lab, University of Antwerp, Universiteitsplein 1, 2610 Wilrijk (Belgium)

    2014-04-01

    Highlights: • We propose the dynamic angle selection algorithm for CT scanning. • The approach is based on the concept of information gain over a set of solutions. • Projection angles are selected based on the already available projection data. • The approach can lead to more accurate results from fewer projections. - Abstract: In X-ray tomography, a number of radiographs (projections) are recorded from which a tomogram is then reconstructed. Conventionally, these projections are acquired equiangularly, resulting in an unbiased sampling of the Radon space. However, especially in case when only a limited number of projections can be acquired, the selection of the angles has a large impact on the quality of the reconstructed image. In this paper, a dynamic algorithm is proposed, in which new projection angles are selected by maximizing the information gain about the object, given the set of possible new angles. Experiments show that this approach can select projection angles for which the accuracy of the reconstructed image is significantly higher compared to the standard angle selections schemes.

  13. A study of images of Projective Angles of pulmonary veins

    Energy Technology Data Exchange (ETDEWEB)

    Wang Jue [Beijing Anzhen Hospital, Beijing (China); Zhaoqi, Zhang [Beijing Anzhen Hospital, Beijing (China)], E-mail: zhaoqi5000@vip.sohu.com; Yu Wei; Miao Cuilian; Yan Zixu; Zhao Yike [Beijing Anzhen Hospital, Beijing (China)

    2009-09-15

    Aims: In images of magnetic resonance and computed tomography (CT) there are visible angles between pulmonary veins and the coronary, transversal or sagittal section of body. In this study these angles are measured and defined as Projective Angles of pulmonary veins. Several possible influential factors and characters of distribution are studied and analyzed for a better understanding of this imaging anatomic character of pulmonary veins. And it could be the anatomic base of adjusting correctly the angle of the central X-ray of the angiography of pulmonary veins undergoing the catheter ablation of atrial fibrillation (AF). Method: Images of contrast enhanced magnetic resonance angiography (CEMRA) and contrast enhanced computer tomography (CECT) of the left atrium and pulmonary veins of 137 health objects and patients with atrial fibrillation (AF) are processed with the technique of post-processing, and Projective Angles to the coronary and transversal sections are measured and analyzed statistically. Result: Project Angles of pulmonary veins are one of real and steady imaging anatomic characteristics of pulmonary veins. The statistical distribution of variables is relatively concentrated, with a fairly good representation of average value. It is possible to improve the angle of the central X-ray according to the average value in the selective angiography of pulmonary veins undergoing the catheter ablation of AF.

  14. Biophysical optimality of the golden angle in phyllotaxis

    Science.gov (United States)

    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. SECONDARY SCHOOL TEACHERS' PERCEPTIONS ON SPIRITUAL LEADERSHIP

    OpenAIRE

    DAĞLI, Abidin

    2014-01-01

    The aim of this study is to investigate the secondary school teachers' perceptions about spiritual leadership in terms of some variables.The population consists of 2893 teachers working in 90 formal secondary schools in the city centre of Diyarbakır in 2012 and 2013 academic year. 29 secondary schools are choosen from the research population with random sampling method and 400 teachers have consisted of the sample. Those 29 secondary schools have been visited and questionnaires have been del...

  16. Secondary Syphilis: Uncommon Manifestations a Common Disease

    OpenAIRE

    McPhee, Stephen J.

    1984-01-01

    Reports of cases of primary and secondary syphilis are increasing in the United States, particularly in urban areas and among homosexual men. While primary syphilis poses little diagnostic difficulty, many physicians are unfamiliar with the multisystem nature of secondary lues. Patients who have secondary syphilis commonly present with systemic signs, skin rash, mucous membrane lesions and generalized adenopathy. Less commonly, secondary syphilis may occur as acute meningitis, sensorineural h...

  17. Higher Secondary School Students’ Attitude towards Chemistry

    OpenAIRE

    Gul Nazir Khan; Arshad Ali

    2012-01-01

    The focus of this study was about higher secondary school students’ attitude towards chemistry subject, chemistry teacher and teaching methodologies of chemistry teacher. Like academic achievement, attitude is considered to be an important product of higher secondary education. The population of this study was all the higher secondary schools students of Khyber Pakhtunkhwa (Pakistan), however due to time constraints and convenience the 35 second year students of government higher secondary sc...

  18. Small-angle proton elastic scattering on Be and B nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Inglessi, A.; Aksouh, F.; Behr, K.H.; Bleile, A.; Bruenle, A.; Egelhof, P.; Geissel, H.; Ickert, G.; Ilieva, S.; Kanungo, R.; Kiselev, O.; Le, X.C.; Litvinov, Y.; Niebur, W.; Nociforo, C.; Weick, H. [Gesellschaft fuer Schwerionenforschung (GSI), Darmstadt (Germany); Alkhazov, G.D.; Dobrovolsky, A.V.; Khanzadeev, A.V.; Korolev, G.A.; Seliverstov, D.M.; Sergeev, L.O.; Vorobyov, A.A.; Yatsoura, V.I.; Zhdanov, A.A. [Petersburg Nuclear Physics Inst. (PNPI), Gatchina (Russian Federation); Chulkov, L.; Volkov, V.A. [Kurchatov Inst., Moscow (Russian Federation)

    2007-07-01

    Small-angle proton elastic scattering on the {sup 7,9,10,11,12,14}Be and {sup 8}B nuclei at energies near 700 MeV/u was studied in inverse kinematics using secondary beams from the fragment separator FRS at GSI, Darmstadt. The hydrogen-filled ionization chamber IKAR served simultaneously as target and recoil proton detector. Projectile tracks measured with multiwire proportional chambers and the ALADIN magnet with a scintillator wall behind served for the separation of elastic scattering events. The obtained differential cross sections will allow to test various theoretical model calculations on the structure of the neutron- and proton-rich (halo) nuclei investigated. In this presentation the experimental setup will be described and the procedure of the data analysis will be displayed. The data analysis is presently in progress. Preliminary results will be presented. (orig.)

  19. Particle size distribution models of small angle neutron scattering pattern on ferro fluids

    International Nuclear Information System (INIS)

    The Fe3O4 ferro fluids samples were synthesized by a co-precipitation method. The investigation of ferro fluids microstructure is known to be one of the most important problems because the presence of aggregates and their internal structure influence greatly the properties of ferro fluids. The size and the size dispersion of particle in ferro fluids were determined assuming a log normal distribution of particle radius. The scattering pattern of the measurement by small angle neutron scattering were fitted by the theoretical scattering function of two limitation models are log normal sphere distribution and fractal aggregate. Two types of particle are detected, which are presumably primary particle of 30 Armstrong in radius and secondary fractal aggregate of 200 Armstrong with polydispersity of 0.47 up to 0.53. (author)

  20. Transcriptional Regulatory Elements in Fungal Secondary Metabolism

    OpenAIRE

    Yin, Wenbing; Keller, Nancy P.

    2011-01-01

    Filamentous fungi produce a variety of secondary metabolites of diverse beneficial and detrimental activities to humankind. The genes encoding the enzymatic machinery required to make these metabolites are typically clustered in fungal genomes. There is considerable evidence that secondary metabolite gene regulation is, in part, by transcriptional control through hierarchical levels of transcriptional regulatory elements involved in secondary metabolite cluster regulation. Identification of s...

  1. Secondary Trauma in Children and School Personnel

    Science.gov (United States)

    Motta, Robert W.

    2012-01-01

    A review of childhood secondary trauma is presented. Secondary trauma involves the transfer and acquisition of negative affective and dysfunctional cognitive states due to prolonged and extended contact with others, such as family members, who have been traumatized. As such, secondary trauma refers to a spread of trauma reactions from the victim…

  2. Universal Secondary Education (USE) in Guyana

    OpenAIRE

    World Bank, (WB)

    2008-01-01

    In 2002, Guyana adopted a broadly-based five year plan (2003-2007) to achieve universal secondary education (USE), with a strategy to convert secondary classes in primary schools and grade 7-10 community high schools into General Secondary Schools (GSS) in which all students could present for the Caribbean Examination Certificate (CXC) or an alternative competency-based Certificate. Curren...

  3. 40 CFR 133.102 - Secondary treatment.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 21 2010-07-01 2010-07-01 false Secondary treatment. 133.102 Section... TREATMENT REGULATION § 133.102 Secondary treatment. The following paragraphs describe the minimum level of effluent quality attainable by secondary treatment in terms of the parameters—BOD5, SS and pH....

  4. 30 CFR 57.6312 - Secondary blasting.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Secondary blasting. 57.6312 Section 57.6312... Transportation-Surface and Underground § 57.6312 Secondary blasting. Secondary blasts fired at the same time in the same work area shall be initiated from one source. Electric Blasting—Surface and Underground...

  5. 30 CFR 56.6312 - Secondary blasting.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Secondary blasting. 56.6312 Section 56.6312... Secondary blasting. Secondary blasts fired at the same time in the same work area shall be initiated from one source. Electric Blasting...

  6. Measurement of critical contact angle in a microgravity space experiment

    Energy Technology Data Exchange (ETDEWEB)

    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. Measurement of critical contact angle in a microgravity space experiment

    Energy Technology Data Exchange (ETDEWEB)

    Concus, P. [California Univ., Berkeley, CA (United States). Lawrence Berkeley Lab.; Finn, R. [Department of Mathematics, Stanford University, CA (United States); Weislogel, M. [NASA Lewis Research Center, Cleveland, OH (United States)

    2000-03-01

    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. (orig.)

  8. On unconstrained SU(2)-gluodynamics with θ-angle

    International Nuclear Information System (INIS)

    The Hamiltonian reduction of classical SU(2) Yang-Mills field theory to the equivalent unconstrained theory of gauge invariant local dynamical variables is generalized to the case of nonvanishing θ-angle. It is shown that for any θ-angle the elimination of the pure gauge degrees of freedom leads to a corresponding unconstrained nonlocal theory of self-interacting second rank symmetric tensor fields, and that the obtained classical unconstrained gluodynamics with different θ-angles are canonically equivalent as on the original constrained level

  9. Angle-action estimation in a general axisymmetric potential

    OpenAIRE

    Sanders, Jason

    2012-01-01

    The usefulness of angle-action variables in galaxy dynamics is well known, but their use is limited due to the difficulty of their calculation in realistic galaxy potentials. Here we present a method for estimating angle-action variables in a realistic Milky Way axisymmetric potential by locally fitting a St\\"ackel potential over the region an orbit probes. The quality of the method is assessed by comparison with other known methods for estimating angle-action variables of a range of disc and...

  10. Research of the Pressure Angle for Whole Cycloidal Gears

    Institute of Scientific and Technical Information of China (English)

    LIU Ling-tao; WANG Jian-hua

    2011-01-01

    The working profile of whole cycloidal gear is made up of epicycloid and hypocycloid entirely, according to the theory of meshing of gears and the properties of the cycloid, deals with the derivation of the pressure angle formula for the whole cycloidal gear in theory, and reveals changes of the pressure angle of whole cycloidal gear through examples, finds the application relationships between the pressure angle and other design parameters of the whole cycloidal gear, proves the possibility that the whole cycloidal gear can be used in internal parallel move gear mechanism, also provides theoretic fundament for designing internal parallel move whole cycloidal gear correctly.

  11. Mixing angle of doubly heavy baryons in QCD

    International Nuclear Information System (INIS)

    We calculate the mixing angles between the spin-1/2, Ξbc-Ξbc′ and Ωbc-Ωbc′ states of doubly heavy baryons within the QCD sum rules method. It is found that the mixing angles are large and have the values φΞbc=16°±5° and φΩbc=18°±6°, respectively. The mixing angles are slightly smaller compared to the predictions of the non-relativistic quark model, φΞbc=25.5° and φΩbc=25.9°.

  12. Drop Size Dependence of the Contact Angle of Nanodroplets

    Institute of Scientific and Technical Information of China (English)

    GUO Hong-Kai; FANG Hai-Ping

    2005-01-01

    @@ The contact angle of nanosized non-polarized argon sessile droplets on a solid substrate is studied by using molecular dynamics simulations.It is found that the drop size dependence of the contact angle is sensitive to the interaction between the liquid molecules and solid molecules.The contact angle decreases with the decreasing drop size for larger interaction between the liquid molecules and the solid substrate, and vice versa.This observation is consistent with most of the previous theoretical and experimental results.

  13. Control of Angular Intervals for Angle-Multiplexed Holographic Memory

    Science.gov (United States)

    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.

  14. Increasing efficacy of graminicides with a forward angled spray

    DEFF Research Database (Denmark)

    Jensen, Peter Kryger

    2012-01-01

    Control of annual grass species with vertically oriented leaves in agricultural crops by application of foliar acting herbicides with conventional hydraulic sprayers can be increased using forward angled nozzles. Changing the spray angle from the normally predominantly vertical spray towards...... efficacy on L. perenne at early growth stages using nozzles with different spray quality, at different driving speeds and in different wind conditions. Similarly graminicide efficacy was increased when nozzles were angled 60° forward controlling A. myosuroides. Experiments investigating control of the two...

  15. The modified Cassie’s equation and contact angle hysteresis

    KAUST Repository

    Xu, Xianmin

    2012-08-29

    In this paper, we derive a modified Cassie\\'s equation for wetting on chemically patterned surfaces from a homogenization approach. The derivation reveals that effective contact angle is a local average of the static contact angle along the contact line which describes all possible equilibrium states including the local minimum of the free energy of the system. The usual Cassie\\'s state which corresponds to the global minimum is only a special case. We then discuss the contact angle hysteresis on chemically patterned surfaces. © 2012 Springer-Verlag.

  16. Wide angle near-field diffraction and Wigner distribution

    CERN Document Server

    Almeida, J B

    2003-01-01

    Free-space propagation can be described as a shearing of the Wigner distribution function in the spatial coordinate; this shearing is linear in paraxial approximation but assumes a more complex shape for wide-angle propagation. Integration in the frequency domain allows the determination of near-field diffraction, leading to the well known Fresnel diffraction when small angles are considered and allowing exact prediction of wide-angle diffraction. The authors use this technique to demonstrate evanescent wave formation and diffraction elimination for very small apertures.

  17. Energy distribution of secondary particles in ion beam deposition process of Ag: experiment, calculation and simulation

    Energy Technology Data Exchange (ETDEWEB)

    Bundesmann, C.; Feder, R.; Lautenschlaeger, T.; Neumann, H. [Leibniz-Institute of Surface Modification, Leipzig (Germany)

    2015-12-15

    Ion beam sputter deposition allows tailoring the properties of the film-forming, secondary particles (sputtered target particles and backscattered primary particles) and, hence, thin film properties by changing ion beam (ion energy, ion species) and geometrical parameters (ion incidence angle, polar emission angle). In particular, the energy distribution of secondary particles and their influence on the ion beam deposition process of Ag was studied in dependence on process parameters. Energy-selective mass spectrometry was used to measure the energy distribution of sputtered and backscattered ions. The energy distribution of the sputtered particles shows, in accordance with theory, a maximum at low energy and an E{sup -2} decay for energies above the maximum. If the sum of incidence angle and polar emission angle is larger than 90 , additional contributions due to direct sputtering events occur. The energy distribution of the backscattered primary particles can show contributions by scattering at target particles and at implanted primary particles. The occurrence of these contributions depends again strongly on the scattering geometry but also on the primary ion species. The energy of directly sputtered and backscattered particles was calculated using equations based on simple two-particle-interaction whereas the energy distribution was simulated using the well-known Monte Carlo code TRIM.SP. In principal, the calculation and simulation data agree well with the experimental findings. (copyright 2015 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  18. An interferometer experiment to explore the aspect angle dependence of stimulated electromagnetic emission spectra

    Directory of Open Access Journals (Sweden)

    Isham

    2005-01-01

    Full Text Available When the Earth's ionosphere is irradiated by a radiofrequency (RF electromagnetic wave of sufficiently high power density and tuned to match a natural E- or F-region plasma frequency, ionospheric magnetoionic wave modes may be excited and may generate RF electromagnetic sideband waves via nonlinear interactions. These secondary emissions, which may then escape from the ionosphere, have been termed stimulated electromagnetic emission or SEE. The frequency spectra of this radiation has been studied extensively, and a number of characteristic spectral features have been identified and in some cases related to particular plasma processes. The separation in frequency between the RF pump and the harmonics of the local electron gyrofrequency is critical in determining the amount of anomalous absorption suffered by the pump wave and the spectral properties of the stimulated sidebands. The pump can excite electrostatic waves which do not propagate away but can in some cases be observed via radio-wave scattering from the electron density fluctuations associated with them. These enhanced density fluctuations are created by processes commonly referred to as upper-hybrid and Langmuir turbulence. Langmuir turbulence has been the subject of 930-MHz scattering observations with antenna scanning through several pre-selected angles between the geographic and geomagnetic zenith directions, and a preference for pointing angles between the Spitze angle and geomagnetic field-aligned was identified. Other phenomena, such as the generation of enhanced electron temperatures and artificial aurora, have more recently been shown to have special behavior at similar angles, near but apparently not quite at field-aligned. In view of this evidence for angular structure in several pump-induced effects, in light of the rich variety of SEE phenomena strongly dependent on the geomagnetic field via the frequency interval between the pump and the gyrofrequency harmonics, and in

  19. NPP Krsko secondary side analysis

    International Nuclear Information System (INIS)

    The purpose of this work is to analyze secondary side thermohydraulics response on steam generator tube plugging in order to ensure nominal NPP power. We had established that the additional opening of the governing valve No. 3 and 4 can compensate pressure drop caused by steam generator tube plugging. Two main steam flows with four governing valves were simulated. Steam expansion in turbine and feed water system was modeled separately. All important process point and steam moisture changes impact on nominal NPP power were analysed. (author)

  20. Secondary emission monitor (SEM) grids.

    CERN Multimedia

    Patrice Loïez

    2002-01-01

    A great variety of Secondary Emission Monitors (SEM) are used all over the PS Complex. At other accelerators they are also called wire-grids, harps, etc. They are used to measure beam density profiles (from which beam size and emittance can be derived) in single-pass locations (not on circulating beams). Top left: two individual wire-planes. Top right: a combination of a horizontal and a vertical wire plane. Bottom left: a ribbon grid in its frame, with connecting wires. Bottom right: a SEM-grid with its insertion/retraction mechanism.

  1. SU-E-I-56: Scan Angle Reduction for a Limited-Angle Intrafraction Verification (LIVE) System

    International Nuclear Information System (INIS)

    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

  2. Arterial secondary blood flow patterns visualized with vector flow ultrasound

    DEFF Research Database (Denmark)

    Pedersen, Mads Møller; Pihl, Michael Johannes; Hansen, Jens Munk;

    2011-01-01

    This study presents the first quantification and visualisation of secondary flow patterns with vector flow ultrasound. The first commercial implementation of the vector flow method Transverse Oscillation was used to obtain in-vivo, 2D vector fields in real-time. The hypothesis of this study...... was that the rotational direction is constant within each artery. Three data sets of 10 seconds were obtained from three main arteries in healthy volunteers. For each data set the rotational flow patterns were identified during the diastole. Each data set contains a 2D vector field over time and with the vector angles...... and velocity magnitudes the blood flow patterns were visualised with streamlines in Matlab (Mathworks, Natick, MA, USA). The rotational flow was quantified by the angular frequency for each cardiac cycle, and the mean rotational frequencies and standard deviations were calculated for the abdominal aorta f-1...

  3. Combined effects of the in-plane orientation angle and the loading angle on the dynamic enhancement of honeycombs under mixed shear-compression loading

    Science.gov (United States)

    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.

  4. Polarization Position Angle Swings caused by Relativistic Effects

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    Polarization position angle swings of ~ 180° observed in extragalacticradio sources are a regular behavior of variability in polarization. They shouldbe due to some kind of physically regular process. We consider relativistic shocksproducing polarization angle swing events. Two magnetic field configurations (force-free field and homogeneous helical field) are considered to demonstrate the results.It is shown that the properties of polarization angle swings and the relationshipbetween the swings and variations in total and polarized flux density are criticallydependent on the configuration of magnetic field and the dynamical behavior of theshock. In particular, we find that in some cases polarization angle swings can occurwhen the total and polarized flux densities only vary by a very small amount. Theseresults may be useful for understanding the polarization variability with both longand short timescales observed in extragalactic radio sources.

  5. On Ruby's solid angle formula and some of its generalizations

    CERN Document Server

    Friot, Samuel

    2014-01-01

    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.

  6. On Ruby's solid angle formula and some of its generalizations

    Science.gov (United States)

    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.

  7. Calculation of Triggering Angle of Thyristor Rectifiers with Evolutionary Algorithms

    Directory of Open Access Journals (Sweden)

    Fahri VATANSEVER

    2015-05-01

    Full Text Available Rectifier circuits have important role in electrical energy systems. Especially in thyristor rectifiers which have capability of generating multiple voltage level, determining/calculating the optimal trigger angle and applying trigger signal at this angles are among the main process. In this study, desired level of average output voltage according to trigger angles is obtained both classically (mathematically solving of equations and using evolutionary algorithms which are genetic algorithms and differential evolutions. In this way, a software can be used in educational purposes which can calculate optimal trigger angles using both mathematically and heuristically, show results and many properties/parameters of circuit graphically and numerically is developed. Analysis/simulations performed with the designed software indicates that evolutionary algorithms can be used in this field effectively and efficiently.

  8. A solution to the Kelvin wake angle controversy

    CERN Document Server

    Darmon, Alexandre; Raphaël, Elie

    2014-01-01

    Gravity waves generated by an object moving at constant speed at the water surface form a specific pattern commonly known as the Kelvin wake. It was proved by Lord Kelvin that such a wake is delimited by a constant angle = 19.47{\\deg}. However a recent study by Rabaud and Moisy based on the observation of airborne images showed that the wake angle seems to decrease as the Froude number Fr increases, scaling as 1/Fr for large Froude numbers. To explain such observations the authors make the strong hypothesis that an object of size b cannot generate wavelengths larger than b thus leading to unrealistic pressure fields to model the object. With no need of such an assumption, we here analytically show that the angle corresponding to the maximum amplitude of the waves scales as 1/Fr for large Froude numbers whereas the Kelvin angle remains constant for all Fr.

  9. Multi-angle Imaging SpectroRadiometer (MISR)

    Data.gov (United States)

    National Aeronautics and Space Administration — The Multi-angle Imaging SpectroRadiometer (MISR) was successfully launched into sun-synchronous polar orbit aboard Terra, NASA's first Earth Observing System (EOS)...

  10. SMALL ANGLE CRAB COMPENSATION FOR LHC IR UPGRADE

    Energy Technology Data Exchange (ETDEWEB)

    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.

  11. Plane waveguides with corners in the small angle limit

    CERN Document Server

    Dauge, Monique

    2012-01-01

    The plane waveguides with corners considered here are infinite V-shaped strips with constant thickness. They are parametrized by their sole opening angle. We study the eigenpairs of the Dirichlet Laplacian in such domains when their angle tends to 0. We provide multi-scale asymptotics for eigenpairs associated with the lowest eigenvalues. For this, we investigate the eigenpairs of a one-dimensional model which can be viewed as their Born-Oppenheimer approximation. We also investigate the Dirichlet Laplacian on triangles with sharp angles. The eigenvalue asymptotics involve powers of the cube root of the angle, while the eigenvector asymptotics include simultaneously two scales in the triangular part, and one scale in the straight part of the guides.

  12. Relations between Distorted and Original Angles in STR

    Directory of Open Access Journals (Sweden)

    Smarandache F

    2013-07-01

    Full Text Available Using the Oblique-Length Contraction Factor, which is a generalization of Lorentz Contraction Factor, one shows several trigonometric relations between distorted and original angles of a moving object lengths in the Special Theory of Relativity

  13. Asronomical refraction: Computational methods for all zenith angles

    Science.gov (United States)

    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.

  14. SMALL ANGLE CRAB COMPENSATION FOR LHC IR UPGRADE

    International Nuclear Information System (INIS)

    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 and 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

  15. Gauge groups from brane-anti-brane systems at angles

    International Nuclear Information System (INIS)

    We discuss a system formed by two pairs of brane-anti-brane that form an arbitrary angle in a plane. We identify the gauge groups from this system which presumably could be used to construct gauge theories. (author)

  16. Gauge groups from brane-anti-brane systems at angles

    Energy Technology Data Exchange (ETDEWEB)

    Vancea, I.V. [Instituto de Fisica Teorica (IFT), Sao Paulo, SP (Brazil)

    2001-07-01

    We discuss a system formed by two pairs of brane-anti-brane that form an arbitrary angle in a plane. We identify the gauge groups from this system which presumably could be used to construct gauge theories. (author)

  17. Gauge groups from brane-anti-brane systems at angles

    Science.gov (United States)

    Vancea, I. V.

    2001-04-01

    We discuss a system formed by two pairs of brane-anti-brane that form an arbitrary angle in a plane. We identify the gauge groups from this system which presumably could be used to construct gauge theories...

  18. First statistics of the isopistonic angle for long baseline interferometry

    Science.gov (United States)

    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.

  19. Parameterization of ion channeling half-angles and minimum yields

    Science.gov (United States)

    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

  20. Setting of angles on machine tools speeded by magnetic protractor

    Science.gov (United States)

    Vale, L. B.

    1964-01-01

    An adjustable protractor facilitates transference of angles to remote machine tools. It has a magnetic base incorporating a beam which can be adjusted until its shadow coincides with an image on the screen of a projector.

  1. Angle Insensitive Color Filters in Transmission Covering the Visible Region

    Science.gov (United States)

    Mao, Kening; Shen, Weidong; Yang, Chenying; Fang, Xu; Yuan, Wenjia; Zhang, Yueguang; Liu, Xu

    2016-01-01

    Angle insensitive color filter based on Metal-SiOx-Metal structure is proposed in this paper, which can keep the same perceived transmitted color when the incidence angle changes from 0° to 60°, especially for p-polarization light. Various silicon oxide films deposited by reaction magnetron sputtering with a tunable refractive index from 1.97 to 3.84 is introduced to meet the strict angle insensitive resonance conditions. The angle resolved spectral filtering for both p-polarization light and s-polarization light are quite well, which can be attributed to the different physical origins for the high angular tolerance for two polarizations. Finally, the effect of SiOx absorption and Ag thickness on the peak transmittance are analyzed.

  2. Shrinkage and trajectory of the flat jet with inclination angle

    Institute of Scientific and Technical Information of China (English)

    Shufeng Ye; Yusheng Xie; Hongzhi Guo; Ye Huang; Shantong Jin

    2003-01-01

    The performance of the flat jet with an inclination angle was investigated by a water model. A mathematical model for theshrinkage and the trajectory of the flat jet with an inclination angle was derived theoretically and verified by experimental data of thewater model. The experimental results indicate that the inclination angle (α) has no influence on the shrinkage of the flat jet, theshrinkage of the flat jet along the width direction decreases with the increasing of the initial velocity at the exit (u0) and the initialthickness of the flat jet (t0). Enough bigger initial exit velocity (u0) and initial thickness can suppress the shrinkage of the flat jetalong the width direction and keep the flat jet stabilized. In addition, the trajectory of the flat jet with an inclination angle is parabolicand must be taking into consideration when to determine the striking distance.

  3. PWR secondary water chemistry guidelines: Revision 3

    International Nuclear Information System (INIS)

    An effective, state-of-the art secondary water chemistry control program is essential to maximize the availability and operating life of major PWR components. Furthermore, the costs related to maintaining secondary water chemistry will likely be less than the repair or replacement of steam generators or large turbine rotors, with resulting outages taken into account. The revised PWR secondary water chemistry guidelines in this report represent the latest field and laboratory data on steam generator corrosion phenomena. This document supersedes Interim PWR Secondary Water Chemistry Recommendations for IGA/SCC Control (EPRI report TR-101230) as well as PWR Secondary Water Chemistry Guidelines--Revision 2 (NP-6239)

  4. Origin of Hinge-Like Mechanism in Single-Layer Black Phosphorus: the Angle-Angle Cross Interaction

    OpenAIRE

    Jiang, Jin-Wu

    2016-01-01

    The single-layer black phosphorus is characteristic for its puckered configuration that possesses the hinge-like mechanism, which leads to the highly anisotropic in-plane Poisson's ratios and the negative out-of-plane Poisson's ratio. We reveal that the hinge-like mechanism can be attributed to the angle-angle cross interaction, which, combined with the bond stretching and angle bending interactions, is able to provide a good description of the mechanical properties in the single-layer black ...

  5. Effect of slope angle of an artificial pool on distributions of turbulence

    Institute of Scientific and Technical Information of China (English)

    Atefeh Fazlollahi; Hossein Afzalimehr; Jueyi Sui

    2015-01-01

    abstract Experiments were carried out over a 2-dimentional pool with a constant length of 1.5 m and four different slopes. The distributions of velocity, Reynolds stress and turbulence intensities have been studied in this paper. Results show that as flow continues up the exit slope, the flow velocity increases near the channel bed and decreases near the water surface. The flow separation was not observed by ADV at the crest of the bed-form. In addition, the length of the separation zone increases with the increasing of entrance and exit slopes. The largest slope angle causes the maximum normalized shear stress. Based on the experiments, it is concluded that the shape of Reynolds stress distribution is generally dependent on the entrance and exit slopes of the pool. Also, the shape of Reynolds stress distribution is affected by both decelerating and accelerating flows. Additionally, with the increase in the slope angle, secondary currents are developed and become more stable. Results of the quadrant analysis show that the momentum between flow and bed-form is mostly transferred by sweep and ejection events.&2015 International Research and Training Centre on Erosion and Sedimentation/the World Association for Sedimentation and Erosion Research. Published by Elsevier B.V. All rights reserved.

  6. iStent trabecular micro-bypass stent for open-angle glaucoma

    Directory of Open Access Journals (Sweden)

    Le K

    2014-09-01

    Full Text Available Kim Le, Hady Saheb Department of Ophthalmology, McGill University, Montreal, QC, Canada Abstract: Trabecular micro-bypass stents, commonly known as iStents, are micro-invasive glaucoma surgery (MIGS devices used to treat open-angle glaucoma. Like other MIGS procedures that enhance trabecular outflow, the iStent lowers intraocular pressure (IOP by creating a direct channel between the anterior chamber and Schlemm’s canal. iStents are typically implanted at the time of phacoemulsification for patients with open-angle glaucoma and visually significant cataracts. This review summarizes the published data regarding the efficacy, safety, and cost considerations of trabecular micro-bypass stents. Most studies found statistically significant reductions in mean IOP and ocular medication use after combined phacoemulsification with single or double iStent implantation. The devices were found to be very safe, with a safety profile similar to that of cataract surgery. Complications were infrequent, with the most common complications being temporary stent obstruction or malposition, which resolved with observation or secondary procedures. Future studies are needed to evaluate long-term outcomes, patient satisfaction, cost effectiveness, and expanded indications. Keywords: iStent, trabecular micro-bypass, glaucoma, MIGS, ab interno, surgery

  7. Protein backbone chemical shifts predicted from searching a database for torsion angle and sequence homology

    International Nuclear Information System (INIS)

    Chemical shifts of nuclei in or attached to a protein backbone are exquisitely sensitive to their local environment. A computer program, SPARTA, is described that uses this correlation with local structure to predict protein backbone chemical shifts, given an input three-dimensional structure, by searching a newly generated database for triplets of adjacent residues that provide the best match in φ/ψ/χ1 torsion angles and sequence similarity to the query triplet of interest. The database contains 15N, 1HN, 1Hα, 13Cα, 13Cβ and 13C' chemical shifts for 200 proteins for which a high resolution X-ray (≤2.4 A) structure is available. The relative importance of the weighting factors for the φ/ψ/χ1 angles and sequence similarity was optimized empirically. The weighted, average secondary shifts of the central residues in the 20 best-matching triplets, after inclusion of nearest neighbor, ring current, and hydrogen bonding effects, are used to predict chemical shifts for the protein of known structure. Validation shows good agreement between the SPARTA-predicted and experimental shifts, with standard deviations of 2.52, 0.51, 0.27, 0.98, 1.07 and 1.08 ppm for 15N, 1HN, 1Hα, 13Cα, 13Cβ and 13C', respectively, including outliers

  8. Radiographic angles in hallux valgus: Comparison between protractor and iPhone measurements.

    Science.gov (United States)

    Meng, Hong-Zheng; Zhang, Wei-Lin; Li, Xiu-Cheng; Yang, Mao-Wei

    2015-08-01

    Radiographic angles are used to assess the severity of hallux valgus deformity, make preoperative plans, evaluate outcomes after surgery, and compare results between different methods. Traditionally, hallux valgus angle (HVA) has been measured by using a protractor and a marker pen with hardcopy radiographs. The main objective of this study is to compare HVA measurements performed using a smartphone and a traditional protractor. The secondary objective was to compare the time taken between those two methods. Six observers measured major HVA on 20 radiographs of hallux valgus deformity with both a standard protractor and an Apple iPhone. Four of the observers repeated the measurements at least a week after the original measurements. The mean absolute difference between pairs of protractor and smartphone measurements was 3.2°. The 95% confidence intervals for intra-observer variability were ±3.1° for the smartphone measurement and ±3.2° for the protractor method. The 95% confidence intervals for inter-observer variability were ±9.1° for the smartphone measurement and ±9.6° for the protractor measurement. We conclude that the smartphone is equivalent to the protractor for the accuracy of HVA measurement. But, the time taken in smartphone measurement was also reduced. PMID:25763918

  9. The Use of Horizontal and Vertical Angles in Terrestrial Navigation

    OpenAIRE

    Lušić, Zvonimir

    2013-01-01

    The methods of determining a ship’s position in terrestrial navigation by using vertical and horizontal angles are nowadays rarely used. The reason is the relative complexity of the procedure and the lack of accuracy of some methods. Different methods of using horizontal and vertical angles to obtain the line of position (LOP) will be presented in this paper, as well as the occurring errors and recommendations for use. In this paper, the sextant will be considered a basic...

  10. A spin- and angle-resolving photoelectron spectrometer

    International Nuclear Information System (INIS)

    A new type of hemispherical electron energy analyzer that permits angle and spin resolved photoelectron spectroscopy has been developed. The analyzer permits standard angle resolved spectra to be recorded with a two-dimensional detector in parallel with spin detection using a mini-Mott polarimeter. General design considerations as well as technical solutions are discussed and test results from the Au(111) surface state are presented.

  11. Wigner Functions for the Pair Angle and Orbital Angular Momentum

    OpenAIRE

    Kastrup, H. A.

    2016-01-01

    The problem of constructing physically and mathematically well-defined Wigner functions for the canonical pair angle and angular momentum is solved. While a key element for the construction of Wigner functions for the planar phase space is the Heisenberg-Weyl group, the corresponding group for the cylindrical phase space is the Euclidean group of the plane and its unitary representations. Here the angle is replaced by the pair (cos,sin) which determines the points on the unit circle uniquely....

  12. Silicone Brushes: Omniphobic Surfaces with Low Sliding Angles.

    Science.gov (United States)

    Wooh, Sanghyuk; Vollmer, Doris

    2016-06-01

    Losing contact: Omniphobic surfaces can be readily produced by acid-catalyzed graft polycondensation of dimethyldimethoxysilane (PDMS). Droplets show a very small contact angle hysteresis as well as a low sliding angle of only a few degrees. The nm-thick PDMS layer is neither easily washed away nor depleted. This method offers a novel approach towards the preparation of super-liquid-repelling surfaces. PMID:27159802

  13. The correlation between quarter point angle and strong absorption radius

    CERN Document Server

    Ma, W H; Mukherjee, S; Wang, Q; Patel, D; Yang, Y Y; Ma, J B; Ma, P; Jin, S L; Bai, Z; Liu, X Q

    2016-01-01

    The main objective of the present work is to correlate quarter-point angle and nuclear radius or nuclear matter distribution. Various phenomenological formulae with parameters for strong absorption radius Rs are obtained and compared by fitting the experimental data of quarter point angle extracted from nuclear elastic scattering reaction systems. The parameterized formula of Rs related to the isospin and binding energy is recommended, that gives a good reproduction of nuclear matter radii of halo nuclei.

  14. Measurement of the angle of superficial tension by images

    Science.gov (United States)

    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.

  15. Reduction of blade passage tone by angle modulation

    Science.gov (United States)

    Fiagbedzi, Y. A.

    1982-05-01

    Blade staggering has been used in both centrifugal and axial flow fans to reduce discrete tones. Impeller hub resilience, causing fan torsional oscillations, appears to be equivalent to blade staggering in that both lead to angle modulation of the blade passage sound. By using Jacobi-Anger expansions, the sound reductions resulting from the angle modulation effects of these two equivalent techniques are predicted. Excellent agreement is found with published data.

  16. Nonadiabatic Geometric Angle in Nuclear Magnetic Resonance Connection

    OpenAIRE

    Cherbal, Omar; Maamache, Mustapha; Drir, Mahrez

    2005-01-01

    By using the Grassmannian invariant-angle coherents states approach, the classical analogue of the Aharonov-Anandan nonadiabatic geometrical phase is found for a spin one-half in Nuclear Magnetic Resonance (NMR). In the adiabatic limit, the semi-classical relation between the adiabatic Berry’s phase and Hannay’s angle gives exactly the experimental result observed by Suter et al[12].

  17. Measurement of Strabismic Angle Using the Distance Krimsky Test

    OpenAIRE

    Joo, Kwang Sic; Koo, Hyun; Moon, Nam Ju

    2013-01-01

    Purpose To evaluate the correlation of the distance Krimsky test and the alternate prism cover test (APCT) for the distance deviation in patients with horizontal strabismus. Methods Forty patients with horizontal strabismus (20 esotropia and 20 exotropia) were included in this study. Patients with a variable angle of deviation, vertical angle over 5 prism diopters, impaired binocular vision, or poor cooperation were excluded. We instructed the patient to look a target 6 meters away, and appli...

  18. Vehicle Sideslip Angle Estimation Based on Hybrid Kalman Filter

    OpenAIRE

    Li, Jing; Zhang, Jiaxu

    2016-01-01

    Vehicle sideslip angle is essential for active safety control systems. This paper presents a new hybrid Kalman filter to estimate vehicle sideslip angle based on the 3-DoF nonlinear vehicle dynamic model combined with Magic Formula tire model. The hybrid Kalman filter is realized by combining square-root cubature Kalman filter (SCKF), which has quick convergence and numerical stability, with square-root cubature based receding horizon Kalman FIR filter (SCRHKF), which has robustness against m...

  19. Neoclassical Pitch-Angle Scattering of Runaway Electrons

    CERN Document Server

    Liu, Jian; Qin, Hong

    2015-01-01

    It is discovered that the tokamak field geometry generates a pitch-angle scattering effect for runaway electrons. This neoclassical pitch-angle scattering is much stronger than the collisional scattering and invalidates the gyro-center model for runaway electrons. As a result, the energy limit of runaway electrons is found to be larger than the prediction of the gyro-center model and to depend heavily on the background magnetic field.

  20. Comparison of different passive knee extension torque-angle assessments

    International Nuclear Information System (INIS)

    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. (paper)

  1. Advanced conduction angle control of permanent magnet brushless motor drives

    OpenAIRE

    Gan, J.; Chan, CC; Jiang, JZ; Chau, KT

    1998-01-01

    A novel advanced conduction angle control scheme for permanent magnet brushless motor drives is presented in this paper. The originality of this scheme is to employ the transformer EMF in stator windings to counteract the rotational EMF by controlling the advanced conduction angle when the motor drive operates above the base speed. Hence the constant-power operation region can be extended considerably, even though the current regulator is in saturation. The attractive feature of the proposed ...

  2. Hail ice impact on composite structures at glancing angles

    OpenAIRE

    Funai, Sho

    2012-01-01

    Aircraft structures are susceptible to damage due to high velocity hail ice impact. These impacts can create nonvisible damage in the structure, jeopardizing its structural integrity. Experiments were completed with simulated hail ice (SHI) impacting T800/3900-2 carbon/ epoxy tape laminates and aluminum panels at various angles. The angled impacts were similar to the normal impacts in the failure propagation of ice as well as the size and shape of the delaminations. Experimental failure thres...

  3. Secondary production in shallow marine environments

    International Nuclear Information System (INIS)

    Recommendations are discussed with regard to population ecology, microbial food webs, marine ecosystems, improved instrumentation, and effects of land and sea on shallow marine systems. The control of secondary production is discussed with regard to present status of knowledge; research needs for studies on dominant secondary producers, food webs that lead to commercial species, and significant features of the trophic structure of shallow water marine communities. Secondary production at the land-water interface is discussed with regard to present status of knowledge; importance of macrophytes to secondary production; export to secondary consumers; utilization of macrophyte primary production; and correlations between secondary production and river discharge. The role of microorganisms in secondary production is also discussed

  4. [Cause of secondary caries and prevention].

    Science.gov (United States)

    Feng, Xiping

    2014-04-01

    Secondary caries is a disease that occurs on the tooth after the filling has been used for a period of time. Secondary caries is also the main reason for the replacement of dental restorations. Regardless of the material used for fillings, secondary caries cannot be completely avoided. The proportion of secondary caries is very high after filling in permanent teeth or primary teeth. Secondary caries mainly occurs because of the formation of micro cracks after filling. When the micro crack width exceeds 50 microm, saliva will enter the micro cracks between the filling and tooth tissue. The cariogenic bacteria in the saliva will grow when the environment of micro cracks is appropriate, thereby producing secondary caries. The prevention of secondary caries includes micro crack control, fluoride use, teeth cleaning, tooth decay and gum disease treatment, and regular checkups. PMID:24881200

  5. Secondary emission electron gun using external primaries

    Science.gov (United States)

    Srinivasan-Rao, Triveni; Ben-Zvi, Ilan; Kewisch, Jorg; Chang, Xiangyun

    2007-06-05

    An electron gun for generating an electron beam is provided, which includes a secondary emitter. The secondary emitter includes a non-contaminating negative-electron-affinity (NEA) material and emitting surface. The gun includes an accelerating region which accelerates the secondaries from the emitting surface. The secondaries are emitted in response to a primary beam generated external to the accelerating region. The accelerating region may include a superconducting radio frequency (RF) cavity, and the gun may be operated in a continuous wave (CW) mode. The secondary emitter includes hydrogenated diamond. A uniform electrically conductive layer is superposed on the emitter to replenish the extracted current, preventing charging of the emitter. An encapsulated secondary emission enhanced cathode device, useful in a superconducting RF cavity, includes a housing for maintaining vacuum, a cathode, e.g., a photocathode, and the non-contaminating NEA secondary emitter with the uniform electrically conductive layer superposed thereon.

  6. Combinatorics of saturated secondary structures of RNA.

    Science.gov (United States)

    Clote, P

    2006-11-01

    Following Zuker (1986), a saturated secondary structure for a given RNA sequence is a secondary structure such that no base pair can be added without violating the definition of secondary structure, e.g., without introducing a pseudoknot. In the Nussinov-Jacobson energy model (Nussinov and Jacobson, 1980), where the energy of a secondary structure is -1 times the number of base pairs, saturated secondary structures are local minima in the energy landscape, hence form kinetic traps during the folding process. Here we present recurrence relations and closed form asymptotic limits for combinatorial problems related to the number of saturated secondary structures. In addition, Python source code to compute the number of saturated secondary structures having k base pairs can be found at the web servers link of bioinformatics.bc.edu/clotelab/. PMID:17147486

  7. Static and Dynamic Contact Angles of Immersed Ferrofluid Droplets

    Science.gov (United States)

    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.

  8. Angle-Resolved Plasmonic Properties of Single Gold Nanorod Dimers

    Institute of Scientific and Technical Information of China (English)

    Jian Wu; Xuxing Lu; Qiannan Zhu; Junwei Zhao; Qishun Shen; Li Zhan; Weihai Ni

    2014-01-01

    Through wet-chemical assembly methods, gold nanorods were placed close to each other and formed a dimer with a gap distance*1 nm, and hence degenerated plasmonic dipole modes of individual nanorods coupled together to produce hybridized bonding and antibonding resonance modes. Previous studies using a condenser for illumination result in averaged signals over all excitation angles. By exciting an individual dimer obliquely at different angles, we demonstrate that these two new resonance modes are highly tunable and sensitive to the angle between the excitation polarization and the dimer orientation, which follows cos2u dependence. Moreover, for dimer structures with various structure angles, the resonance wavelengths as well as the refractive index sensitivities were found independent of the structure angle. Cal-culated angle-resolved plasmonic properties are in good agreement with the measurements. The assembled nanostructures investigated here are important for fundamental researches as well as potential applications when they are used as building blocks in plasmon-based optical and optoelectronic devices.

  9. Method for producing angled optical fiber tips in the laboratory

    Science.gov (United States)

    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.

  10. Operating experience with main blowers with variable blade angles

    Energy Technology Data Exchange (ETDEWEB)

    Bogatov, I.V.; Spivak, V.A.

    1986-05-01

    Efficiency of blowers used for ventilation in underground coal mines in the USSR in many cases is below the statistical efficiency level. Efficiency of 30% of blowers does not exceed 60%. New design of blower blades developed and tested in the USSR is an easy and economic way for increasing blower efficiency. Each blade consists of 2 sections: a stationary section and a section with a variable-incidence angle. The incidence angle depends on local conditions and requirements for ventilation. During performance tests of VTsZ-32 blowers in the PKAA mine an angle of blade incidence of 20 or 30 degrees was used. This guaranteed air pressure of 6,000 Pa and air output of 120 m/sup 3//s. Increased blade incidence angle was used in summer and during periods of increased methane emission. In winter angle of blade incidence was reduced to 10 degrees, blower output ranged from 80 to 90 m/sup 3//s, air pressure declined to 3,800 Pa. Using blower blades with variable-incidence angle reduced energy consumption, ventilation cost and investment.

  11. Hybrid algorithm for rotor angle security assessment in power systems

    Directory of Open Access Journals (Sweden)

    D. Prasad Wadduwage

    2015-08-01

    Full Text Available Transient rotor angle stability assessment and oscillatory rotor angle stability assessment subsequent to a contingency are integral components of dynamic security assessment (DSA in power systems. This study proposes a hybrid algorithm to determine whether the post-fault power system is secure due to both transient rotor angle stability and oscillatory rotor angle stability subsequent to a set of known contingencies. The hybrid algorithm first uses a new security measure developed based on the concept of Lyapunov exponents (LEs to determine the transient security of the post-fault power system. Later, the transient secure power swing curves are analysed using an improved Prony algorithm which extracts the dominant oscillatory modes and estimates their damping ratios. The damping ratio is a security measure about the oscillatory security of the post-fault power system subsequent to the contingency. The suitability of the proposed hybrid algorithm for DSA in power systems is illustrated using different contingencies of a 16-generator 68-bus test system and a 50-generator 470-bus test system. The accuracy of the stability conclusions and the acceptable computational burden indicate that the proposed hybrid algorithm is suitable for real-time security assessment with respect to both transient rotor angle stability and oscillatory rotor angle stability under multiple contingencies of the power system.

  12. Jet opening angles and gamma-ray brightness of AGN

    CERN Document Server

    Pushkarev, A B; Lister, M L; Savolainen, T

    2009-01-01

    We have investigated the differences in apparent opening angles between the parsec-scale jets of the active galactic nuclei (AGN) detected by the Fermi Large Area Telescope (LAT) during its first three months of operations and those of non-LAT-detected AGN. We used 15.4 GHz VLBA observations of sources from the 2 cm VLBA MOJAVE program, a subset of which comprise the statistically complete flux density limited MOJAVE sample. We determined the apparent opening angles by analyzing transverse jet profiles from the data in the image plane and by applying a model fitting technique to the data in the (u,v) plane. Both methods provided comparable opening angle estimates. The apparent opening angles of gamma-ray bright blazars are preferentially larger than those of gamma-ray weak sources. At the same time, we have found the two groups to have similar intrinsic opening angle distributions. This suggests that the jets in gamma-ray bright AGN are oriented at preferentially smaller angles to the line of sight resulting ...

  13. Limbus Impact on Off-angle Iris Degradation

    Energy Technology Data Exchange (ETDEWEB)

    Karakaya, Mahmut [ORNL; Barstow, Del R [ORNL; Santos-Villalobos, Hector J [ORNL; Thompson, Joseph W [ORNL; Bolme, David S [ORNL; Boehnen, Chris Bensing [ORNL

    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.

  14. Evolution of the jet opening angle distribution in holographic plasma

    CERN Document Server

    Rajagopal, Krishna; van der Schee, Wilke

    2016-01-01

    We use holography to analyze the evolution of an ensemble of jets, with an initial probability distribution for their energy and opening angle as %for jets in proton-proton (pp) collisions, as they propagate through an expanding cooling droplet of strongly coupled plasma as in heavy ion collisions. We identify two competing effects: (i) each individual jet widens as it propagates; (ii) the opening angle distribution for jets emerging from the plasma within any specified range of energies has been pushed toward smaller angles, comparing to pp jets with the same energies. The second effect arises because small-angle jets suffer less energy loss and because jets with a higher initial energy are less probable in the ensemble. We illustrate both effects in a simple two-parameter model, and find that their consequence in sum is that the opening angle distribution for jets in any range of energies contains fewer narrow and wide jets. Either effect can dominate in the mean opening angle, for not unreasonable values o...

  15. Painting within BWR secondary containment

    International Nuclear Information System (INIS)

    Paint solvents deposited on charcoal adsorbers used in the standby gas treatment (SBGT) system can reduce the methyl iodide removal efficiency of the adsorbers. The U.S. Nuclear Regulatory Commission (NRC) has imposed regulations in the form of technical specifications in order to mitigate the consequences of potential charcoal adsorber poisoning. Specifically, Monticello Nuclear Generating Plant's technical specifications require that the filters be tested following painting, fire or chemical release in any ventilation zone communicating with the system while the system is operating that could contaminate the HEPA filters or charcoal adsorbers. A method has been developed to determine the maximum allowable painting rate within secondary containment such that the quantity of organic solvents in the building at any time is always less than that which could potentially reduce the charcoal adsorber removal efficiency below the technical specification limit of 90%. This method allows many types of paints to be used within containment, although maximum allowable painting rates will decrease for paints with high quantities of hydrocarbon solvents or slow drying times. Controls in the form of a painting procedure have been put in place to ensure the analysis remains valid during all painting projects. Strict control over painting within secondary containment will ensure the integrity of the charcoal adsorbers and thus enhance the safe operation of the plant

  16. Secondary Flow Patterns of Liquid Ejector with Computational Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Kwon, Kwisung; Yun, Jinwon; Yu, Sangseok [Chungnam National University, Daejeon (Korea, Republic of); Sohn, Inseok [COAVIS, Sejong (Korea, Republic of); Seo, Yongkyo [Korea Automotive Technology Institute, Cheonan (Korea, Republic of)

    2015-02-15

    An ejector is a type of non-powered pump that is used to supply a secondary flow via the ejection of a primary flow. It is utilized in many industrial fields, and is used for fueling the vehicle because of less failures and simple structure. Since most of ejectors in industry are gas-to-gas and liquid to gas ejector, many research activities have been reported in optimization of gas ejector. On the other hand, the liquid ejector is also applied in many industry but few research has been reported. The liquid ejector occurs cavitation, and it causes damage of parts. Cavitation has bees observed at the nozzle throat at the specified pressure. In this study, a two-dimensional axisymmetric simulation of a liquid-liquid ejector was carried out using five different parameters. The angle of the nozzle plays an important role in the cavitation of a liquid ejector, and the performance characteristics of the flow ratio showed that an angle of 35° was the most advantageous. The simulation results showed that the performance of the liquid ejector and the cavitation effect have to be considered simultaneously.

  17. Secondary Flow Patterns of Liquid Ejector with Computational Analysis

    International Nuclear Information System (INIS)

    An ejector is a type of non-powered pump that is used to supply a secondary flow via the ejection of a primary flow. It is utilized in many industrial fields, and is used for fueling the vehicle because of less failures and simple structure. Since most of ejectors in industry are gas-to-gas and liquid to gas ejector, many research activities have been reported in optimization of gas ejector. On the other hand, the liquid ejector is also applied in many industry but few research has been reported. The liquid ejector occurs cavitation, and it causes damage of parts. Cavitation has bees observed at the nozzle throat at the specified pressure. In this study, a two-dimensional axisymmetric simulation of a liquid-liquid ejector was carried out using five different parameters. The angle of the nozzle plays an important role in the cavitation of a liquid ejector, and the performance characteristics of the flow ratio showed that an angle of 35° was the most advantageous. The simulation results showed that the performance of the liquid ejector and the cavitation effect have to be considered simultaneously

  18. Doppler angle correction in the measurement of intrarenal parameters

    Directory of Open Access Journals (Sweden)

    Mennitt K

    2011-03-01

    Full Text Available Jing Gao¹, Keith Hentel¹, Qiang Zhu², Teng Ma², George Shih¹, Kevin Mennitt¹, Robert Min¹¹Department of Radiology, New York Presbyterian Hospital, Weill Cornell Medical College, NY, USA; ²Division of Diagnostic Ultrasound, Department of Radiology, Beijing Tongren Hospital, Capital Medical University, Beijing, ChinaBackground: The aim of this study was to assess differences in intrarenal artery Doppler parameters measured without and with Doppler angle correction.Methods: We retrospectively reviewed color duplex sonography in 30 normally functioning kidneys (20 native kidneys in 10 subjects and 10 transplanted kidneys in 10 subjects performed between January 26, 2010 and July 26, 2010. There were 10 age-matched men and10 age-matched women (mean 39.8 ± 12.2, range 21–60 years in this study. Depending on whether the Doppler angle was corrected in the spectral Doppler measurement, Doppler parameters including peak systolic velocity (PSV, end-diastolic velocity (EDV, and resistive index (RI measured at the interlobar artery of the kidney were divided into two groups, ie, initial Doppler parameters measured without Doppler angle correction (Group 1 and remeasured Doppler parameters with Doppler angle correction (Group 2. Values for PSV, EDV, and RI measured without Doppler angle correction were compared with those measured with Doppler angle correction, and were analyzed statistically with a paired-samples t-test.Results: There were statistical differences in PSV and EDV at the interlobar artery in the upper, mid, and lower poles of the kidney between Group 1 and Group 2 (all P < 0.001. PSV and EDV in Group 1 were significantly lower than in Group 2. RI in Group 1 was the same as that in Group 2 in the upper, mid, and lower poles of the kidneys.Conclusion: Doppler angle correction plays an important role in the accurate measurement of intrarenal blood flow velocity. The true flow velocity converted from the maximum Doppler velocity shift

  19. The Management of Secondary Glaucoma in Nanophthalmic Patients

    Institute of Scientific and Technical Information of China (English)

    Shengsong Huang; Minbin Yu; Changyu Qiu; Tiancai Ye

    2002-01-01

    Purpose: To investigate the clinical characteristcs, management of secondary glaucoma in nanophthalmos, and the prevention of its complications.Methods: Retrospectively, 9 cases (17 eyes) with nanophthalmic glaucoma were studied.Results: The axial length of the eyes ranged (14.36 ~ 19.33) mm; All of the cases combined with hyperopia ranged (+7.00~+16.00)D. All 17 eyes had the manifestation like angle-closure glaucoma.The glaucoma was controlled in 9 of 17 eyes at the early stage, which underwent laser iridotomy (4 of 9 eyes also underwent laser iridoplasty). 1 eye underwent ciliary photocoagulation because its visual acuity was lost and the patient complained of pain. The other 7 eyes underwent filtration surgery and 3 of them had permanent loss of vision caused by disastrous complications after the surgery.Conclusions: Management of secondary glaucoma in nanophthalmos is complicated. The laser iris surgery is safe and effective in glaucoma at the early stage. Vortex vein decompression, sclerotectomy or anterior sclerotomy may be performed to reduce disastrous complications.

  20. Analysis of secondary coxarthrosis by three dimensional computed tomography

    International Nuclear Information System (INIS)

    The majority of coxarthrosis in Japan is due to congenital dislocation of the hip and acetabular dysplasia. Until now coxarthrosis has been chiefly analyzed on the basis of anterior-posterior radiographs. By using three-dimensional (3D) CT, it was possible to analyze the morphological features of secondary coxarthrosis more accurately, and by using new computer graphics software, it was possible to display the contact area in the hip joint and observe changes associated with progression of the stages of the disease. There were 34 subjects (68 joints), and all of who were women. The CT data were read into a work station, and 3D reconstruction was achieved with hip surgery simulation software (SurgiPlan). Pelvic inclination, acetabular anteversion, seven parameters indicating the investment of the femoral head and two indicating the position of the hip joint in the pelvis were measured. The results showed that secondary coxarthrosis is characterized not only by lateral malposition of the hip joint according to the pelvic coordinates, but by anterior malposition as well. Many other measurements provided 3D information on the acetabular dysplasia. Many of them were correlated with the CE angle on plain radiographs. Furthermore, a strong correlation was not found between anterior and posterior acetabular coverage of the femoral head. In addition, SurgiPlan's distance mapping function enabled 3D observation of the pattern of progression of arthrosis based on the pattern of progression of joint space narrowing. (author)

  1. Analysis of secondary coxarthrosis by three dimensional computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Hemmi, Osamu [Keio Univ., Tokyo (Japan). School of Medicine

    1997-11-01

    The majority of coxarthrosis in Japan is due to congenital dislocation of the hip and acetabular dysplasia. Until now coxarthrosis has been chiefly analyzed on the basis of anterior-posterior radiographs. By using three-dimensional (3D) CT, it was possible to analyze the morphological features of secondary coxarthrosis more accurately, and by using new computer graphics software, it was possible to display the contact area in the hip joint and observe changes associated with progression of the stages of the disease. There were 34 subjects (68 joints), and all of who were women. The CT data were read into a work station, and 3D reconstruction was achieved with hip surgery simulation software (SurgiPlan). Pelvic inclination, acetabular anteversion, seven parameters indicating the investment of the femoral head and two indicating the position of the hip joint in the pelvis were measured. The results showed that secondary coxarthrosis is characterized not only by lateral malposition of the hip joint according to the pelvic coordinates, but by anterior malposition as well. Many other measurements provided 3D information on the acetabular dysplasia. Many of them were correlated with the CE angle on plain radiographs. Furthermore, a strong correlation was not found between anterior and posterior acetabular coverage of the femoral head. In addition, SurgiPlan`s distance mapping function enabled 3D observation of the pattern of progression of arthrosis based on the pattern of progression of joint space narrowing. (author)

  2. Experimental Studies on Grooved Surfaces to Suppress Secondary Electron Emission

    International Nuclear Information System (INIS)

    Grooved surfaces are effective to suppress the secondary electron emission, and can be a promising technique to mitigate the electron cloud effect in positron/proton storage rings. Aiming for the application in a dipole-type magnetic field, various shapes of triangular grooved surfaces have been studied at KEK. The grooves tested here have vertex angles of 20-30o, depths of 2.5-5.0 mm, and vertex roundness of 0.05-0.2 mm. In a laboratory, the secondary electron yields (SEY) of small test pieces were measured using an electron beam in a magnetic-free condition. The grooved surfaces clearly had low SEY compared to flat surfaces of the same materials. The grooves with sharper vertexes had smaller SEY. A test chamber installed in a wiggler magnet of the KEKB positron ring was used to investigate the efficacy of the grooved surface in a strong magnetic field. In the chamber, a remarkable reduction in the electron density around the beam orbit was observed compared to the case of a flat surface with TiN coating.

  3. High Pressure Angle Gears: Comparison to Typical Gear Designs

    Science.gov (United States)

    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).

  4. Rotating Shaft Tilt Angle Measurement Using an Inclinometer

    Science.gov (United States)

    Luo, Jun; Wang, Zhiqian; Shen, Chengwu; Wen, Zhuoman; Liu, Shaojin; Cai, Sheng; Li, Jianrong

    2015-10-01

    This paper describes a novel measurement method to accurately measure the rotating shaft tilt angle of rotating machine for alignment or compensation using a dual-axis inclinometer. A model of the rotating shaft tilt angle measurement is established using a dual-axis inclinometer based on the designed mechanical structure, and the calculation equation between the rotating shaft tilt angle and the inclinometer axes outputs is derived under the condition that the inclinometer axes are perpendicular to the rotating shaft. The reversal measurement method is applied to decrease the effect of inclinometer drifts caused by temperature, to eliminate inclinometer and rotating shaft mechanical error and inclinometer systematic error to attain high measurement accuracy. The uncertainty estimation shows that the accuracy of rotating shaft tilt angle measurement depends mainly on the inclinometer uncertainty and its uncertainty is almost the same as the inclinometer uncertainty in the simulation. The experimental results indicate that measurement time is 4 seconds; the range of rotating shaft tilt angle is 0.002° and its standard deviation is 0.0006° using NS-5/P2 inclinometer, whose precision and resolution are ±0.01° and 0.0005°, respectively.

  5. Automated measurement of diagnostic angles for hip dysplasia

    Science.gov (United States)

    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.

  6. Epidemiological characterization of primary open-angle glaucoma

    Directory of Open Access Journals (Sweden)

    Leonor Rosario Díaz Alfonso

    2010-11-01

    Full Text Available Background: The primary open-angle glaucoma is a problem for public health all over the world. It is a silent and slowly progressive disease leading to blindness. In most patients this can be prevented if the risk factors leading to the disease are detected in time. Objective: To describe some epidemiological factors of patients with primary open-angle glaucoma. Methods: Clinical, epidemiological, prospective and longitudinal study in patients with primary open-angle glaucoma who attended the glaucoma consultation of the Provincial General University Hospital "Dr. Gustavo Aldereguía Lima" of Cienfuegos, from January to February 2009. The following variables were analyzed: age, sex, family and personal medical history, toxic habits and time of diagnosis of the disease. Results: There was prevalence of primary open-angle glaucoma (87, 5% mostly in females (53, 6% and patients over 61 years old as well as in white skinned patients (52 and 62% respectively. Hypertension was the leading entity referred to as pathological personal and family antecedent (62 and 42% respectively. Glaucoma and myopia predominated as previous eye history. The most frequent toxic habits were the consumption of more than 2 cups of coffee a day (53% and smoking (32%. The largest amount of patients had more than 5 years evolution of the disease. Conclusions: Primary open-angle glaucoma occurred mainly in female patients and those with a history

  7. Analyzing angle crashes at unsignalized intersections using machine learning techniques.

    Science.gov (United States)

    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). PMID:21094345

  8. Numerical study of hub taper angle on podded propeller performance

    International Nuclear Information System (INIS)

    Presently, the majority of podded propulsion systems are of the pulling type, because this type provides better hydrodynamic efficiency than the pushing type. There are several possible explanations for the better overall performance of a puller type podded propulsor. One is related to the difference in hub shape. Puller and pusher propellers have opposite hub taper angles, hence different hub and blade root shape. These differences cause changes in the flow condition and possibly influence the overall performance. The current study focuses on the variation in performance of pusher and puller propellers with the same blade sections, but different hub taper angles. A hyperboloidal low order source doublet steady/unsteady time domain panel method code was modified and used to evaluate effects of hub taper angle on the open water propulsive performance of some fixed pitch screw propellers used in podded propulsion systems. The modified code was first validated against measurements of two model propellers in terms of average propulsive performance and good agreement was found. Major findings include significant effects of hub taper angle on propulsive performance of tapered hub propellers and noticeable effects of hub taper angle on sectional pressure distributions of tapered hub propeller blades. (author)

  9. Rotational Angle Measurement of Bridge Support Using Image Processing Techniques

    Directory of Open Access Journals (Sweden)

    Young-Soo Park

    2016-01-01

    Full Text Available Measuring a very small rotational angle accurately and dynamically is indeed a challenging issue, especially in the case of bridge support. Also, existing inclinometers do not have sufficient resolution and accuracy to measure a bridge’s rotational angle. In this study, a new measurement system was developed to provide a practical means for measuring dynamic rotational angle of a bridge support. It features high resolution and accuracy compared with the available systems on the market. By the combinational use of a laser pointer and a vision-based displacement measurement system, the measurement accuracy was significantly increased. The accuracy and applicability were investigated through laboratory tests. From the laboratory tests, it has been found that the developed system can be applicable to bridge support with very small rotational angle. The effectiveness of the developed system was verified through field tests on real bridges. From the full-scale implementation on two PSC girder bridges, it is observed that the proposed system can measure the rotational angle with a high accuracy and reliability.

  10. Dynamical deformed Airy beams with arbitrary angles between two wings.

    Science.gov (United States)

    Liang, Yi; Hu, Yi; Ye, Zhuoyi; Song, Daohong; Lou, Cibo; Zhang, Xinzheng; Xu, Jingjun; Morandotti, Roberto; Chen, Zhigang

    2014-07-01

    We study both numerically and experimentally the acceleration and propagation dynamics of 2D Airy beams with arbitrary initial angles between their "two wings." Our results show that the acceleration of these generalized 2D Airy beams strongly depends on the initial angles and cannot be simply described by the vector superposition principle (except for the normal case of a 90° angle). However, as a result of the "Hyperbolic umbilic" catastrophe (a two-layer caustic), the main lobes of these 2D Airy beams still propagate along parabolic trajectories even though they become highly deformed. Under such conditions, the peak intensity (leading energy flow) of the 2D Airy beams cannot be confined along the main lobe, in contrast to the normal 90° case. Instead, it is found that there are two parabolic trajectories describing the beam propagation: one for the main lobe, and the other for the peak intensity. Both trajectories can be readily controlled by varying the initial wing angle. Due to their self-healing property, these beams tend to evolve into the well-known 1D or 2D Airy patterns after a certain propagation distance. The theoretical analysis corroborates our experimental observations, and explains clearly why the acceleration of deformed Airy beams increases with the opening of the initial wing angle. PMID:25121433

  11. Determination of refractive index of various materials on Brewster angle

    CERN Document Server

    Tikhonov, Eugene A

    2015-01-01

    Studied experimentally the origin of the non-zero reflection of p-polarized radiation (TM) of Brewster's angle. The results have shown the residual reflected light in the vicinity of Brewster angle occurs due to inaccessibility 100% polarization degree the incident linearly-polarized radiation and installation of the zero azimuthal angle. These factors create the s-component of the radiation reflected from the examined surface indeed. A smooth change of reflected light polarization in the vicinity of Brewster angle in the sequence p-s-p appears due to the changing power proportion of reflected p-, and s-components but not is the result of the atomically thin transitional layer at the border of the material/environment according to Drude model. Metrological aspects of refractive index measurement by Brewster angle are investigated: due to the above-mentioned factors, as well as due to the contribution of the reflected scattered light caused by on residual roughness of the optical surface. Advantages of Brewste...

  12. Scattering-angle based filtering of the waveform inversion gradients

    KAUST Repository

    Alkhalifah, Tariq Ali

    2014-11-22

    Full waveform inversion (FWI) requires a hierarchical approach to maneuver the complex non-linearity associated with the problem of velocity update. In anisotropic media, the non-linearity becomes far more complex with the potential trade-off between the multiparameter description of the model. A gradient filter helps us in accessing the parts of the gradient that are suitable to combat the potential non-linearity and parameter trade-off. The filter is based on representing the gradient in the time-lag normalized domain, in which the low scattering angle of the gradient update is initially muted out in the FWI implementation, in what we may refer to as a scattering angle continuation process. The result is a low wavelength update dominated by the transmission part of the update gradient. In this case, even 10 Hz data can produce vertically near-zero wavenumber updates suitable for a background correction of the model. Relaxing the filtering at a later stage in the FWI implementation allows for smaller scattering angles to contribute higher-resolution information to the model. The benefits of the extended domain based filtering of the gradient is not only it\\'s ability in providing low wavenumber gradients guided by the scattering angle, but also in its potential to provide gradients free of unphysical energy that may correspond to unrealistic scattering angles.

  13. Citalopram associated with acute angle-closure glaucoma: case report

    Directory of Open Access Journals (Sweden)

    Hassan Sabit

    2005-10-01

    Full Text Available Abstract Background Acute angle-closure glaucoma is a rare complication in patients receiving anti-depressant treatment. In the following case, we report the development of acute angle closure glaucoma in a patient who overdosed on Citalopram, an antidepressant, and discuss the possible etiological mechanisms for the condition. Case presentation We report a 54 year old, Caucasian lady, with depression and alcohol dependence syndrome, who developed acute angle-closure glaucoma after an overdose of Citalopram, along with alcohol. She was treated with medications and had bilateral Yag laser iridotomies to correct the glaucoma and has made complete recovery. In this case, the underlying cause for glaucoma appears to be related to the ingestion of Citalopram. Conclusion The patho-physiological basis for acute angle closure glaucoma in relation to antidepressant medications remains unclear. The authors suggest Citalopram may have a direct action on the Iris or Ciliary body muscle through serotonergic or anti-cholinergic mechanisms or both. This case highlights the importance of the awareness of the underlying risks, which may predispose an individual to develop acute angle-closure glaucoma, and reminds the clinicians the significance of history taking and examination of the eye before and after starting anti-depressants. This area needs to be further researched.

  14. Constant-variable flip angles for hyperpolarized media MRI

    Science.gov (United States)

    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.

  15. Multi angle view of lung using optical coherence tomography (OCT)

    Science.gov (United States)

    Golabchi, Ali; DiMarzio, Charles A.; Gouldstone, Andrew

    2012-03-01

    Lung imaging, visualization and measurement of alveolar volume has great importance in determining lung health. However, the heterogeneity of lung tissue complicates this task. In this paper multi angle Optical Coherence Tomography (OCT) is used to overcome this problem. One of the limitations of utilizing OCT in lung is the speckle noise and artifacts that originate from the refraction at the tissue-air interface inside the lung. Multi angle view of lung using OCT is incoherent summation of multiple angle-diverse images. Utilizing image registration of multi angle OCT scans of the lung helps reduce the speckle noise and refraction artifacts. This technique helps extract more information from the images which improves visualization and the ability to measure the geometry of alveoli. The other diculty of utilizing OCT is interpreting the images due to the low numerical aperture (NA) on the OCT. The multi angle view of the lung increases NA, which increase the imaging resolution through synthetic aperture imaging. In this paper in ated excised lung tissue and lung phantom are presented.

  16. Low frequency seabed scattering at low grazing angles.

    Science.gov (United States)

    Zhou, Ji-Xun; Zhang, Xue-Zhen

    2012-04-01

    Low-frequency (LF) seabed scattering at low grazing angles (LGA) is almost impossible to directly measure in shallow water (SW), except through inversion from reverberation. The energy flux method for SW reverberation is briefly introduced in this paper. The closed-form expressions of reverberation in an isovelocity waveguide, derived from this method, indicate that in the three-halves law range interval multimode/ray sea bottom scattering with different incident and scattering angles in forming the reverberation may equivalently be represented by the bottom backscattering at a single range-dependent angle. This equivalent relationship is used to derive the bottom backscattering strength (BBS) as a function of angle and frequency. The LF&LGA BBS is derived in a frequency band of 200-2500 Hz and in a grazing angle range of 1.1°-14.0° from reverberation measurements at three sites with sandy bottoms. This is based on three previous works: (1) The closed-form expressions of SW reverberation [Zhou, (Chinese) Acta Acustica 5, 86-99 (1980)]; (2) the effective geo-acoustic model of sandy bottoms that follows the Biot model [Zhou et al., J. Acoust. Soc. Am. 125, 2847-2866 (2009)] and (3) A quality database of wideband reverberation level normalized to source level [Zhou and Zhang, IEEE J. Oceanic Eng. 30, 832-842 (2005)]. PMID:22501042

  17. Controlling Compressor Vane Flow Vectoring Angles at Transonic Speeds

    Science.gov (United States)

    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.

  18. Disassembling the Galaxy with angle-action coordinates

    CERN Document Server

    McMillan, Paul J

    2008-01-01

    Angle-action coordinates are used to study the relic of a self-gravitating satellite galaxy that was released on a short-period orbit within the disc of the Galaxy. Satellite stars that lie within 1.5 kpc of the Sun are confined to a grid of patches in action space. As the relic phase-mixes for longer, the patches become smaller and more numerous. These patches can be seen even when the angle-action coordinates of an erroneous Galactic potential are used, but using the wrong potential displaces them. Diagnostic quantities constructed from the angle coordinates both allow the true potential to be identified, and the relic to be dated. Hence when large numbers of solar-neighbourhood stars have full phase-space coordinates, it should be possible to identify members of particular relics from the distribution of stars in an approximate action space, and then the relic's age and the Galactic potential precisely measured using angle coordinates. The availability of angle-action coordinates for arbitrary potentials i...

  19. Numerical study of hub taper angle on podded propeller performance

    Energy Technology Data Exchange (ETDEWEB)

    Islam, M.F.; Veitch, B.; Bose, N. [Memorial Univ. of Newfoundland, Faculty of Engineering and Applied Science, St. John' s, Newfoundland (Canada)]. E-mail: Mohammed.Islam@nrc-cnrc.gc.ca; Liu, P. [National Research Council of Canada, Inst. for Ocean Technology (IOT), St. John' s, Newfoundland (Canada)

    2005-07-01

    Presently, the majority of podded propulsion systems are of the pulling type, because this type provides better hydrodynamic efficiency than the pushing type. There are several possible explanations for the better overall performance of a puller type podded propulsor. One is related to the difference in hub shape. Puller and pusher propellers have opposite hub taper angles, hence different hub and blade root shape. These differences cause changes in the flow condition and possibly influence the overall performance. The current study focuses on the variation in performance of pusher and puller propellers with the same blade sections, but different hub taper angles. A hyperboloidal low order source doublet steady/unsteady time domain panel method code was modified and used to evaluate effects of hub taper angle on the open water propulsive performance of some fixed pitch screw propellers used in podded propulsion systems. The modified code was first validated against measurements of two model propellers in terms of average propulsive performance and good agreement was found. Major findings include significant effects of hub taper angle on propulsive performance of tapered hub propellers and noticeable effects of hub taper angle on sectional pressure distributions of tapered hub propeller blades. (author)

  20. Antifungal Activity of Microbial Secondary Metabolites

    OpenAIRE

    Jeffrey J Coleman; Ghosh, Suman; Okoli, Ikechukwu; Mylonakis, Eleftherios

    2011-01-01

    Secondary metabolites are well known for their ability to impede other microorganisms. Reanalysis of a screen of natural products using the Caenorhabditis elegans-Candida albicans infection model identified twelve microbial secondary metabolites capable of conferring an increase in survival to infected nematodes. In this screen, the two compound treatments conferring the highest survival rates were members of the epipolythiodioxopiperazine (ETP) family of fungal secondary metabolites, acetylg...