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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. Arteriovenous malformation in the cerebellopontine angle presenting as trigeminal neuralgia

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    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.

  3. Cerebellar glioblastoma multiforme presenting as a cerebellopontine angle mass

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    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.

  4. 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

  5. Solitary Fibrous Tumor of the Cerebello-Pontine Angle

    Science.gov (United States)

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

    1999-01-01

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

  6. Malignant melanoma of the cerebello-pontine angle region

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    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.

  7. Disorders of the cerebellopontine angle; Klinik der Kleinhirnbrueckenwinkelerkrankungen

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    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.)

  8. Endolymphatic sac tumor : a rare cerebellopontine angle tumor.

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    Joseph B

    2002-10-01

    Full Text Available Endolymphatic sac tumors (ELST are rare papillary tumors of the temporal bone. Previously named as aggressive papillary middle ear tumors, they have recently been shown to arise from the endolymphatic sac. They are a rare in cerebello-pontine angle (CPA. We present a case of an ELST who presented as a CPA tumor with hydrocephalus. He underwent a ventriculo-peritoneal shunt initially. On exploration of the CP angle, the tumor was found to be extremely vascular. He was re-explored following embolization, and a subtotal excision of the tumor was done. Extensive petrous bone infiltration and vascularity of the tumor makes total excision almost impossible with high risk of cranial nerve deficits, excessive blood loss and CSF leak. This tumor should be considered in the differential diagnosis of vascular CPA tumors which erode the petrous temporal bone. The relevant literature is reviewed.

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

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

    Science.gov (United States)

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

    2012-02-01

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

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

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    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.)

  12. Surgical Outcomes of Cerebellopontine angle Tumors in 50 Cases

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    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.

  13. 桥小脑角区小型占位致继发性三叉神经痛的手术疗效分析%Surgical outcome after resection of small cerebellopontine angle lesions resulted in secondary trigeminal neuralgia

    Institute of Scientific and Technical Information of China (English)

    陶传元; 魏攀; 庄进学; 陈登奎; 程宏炜; 宋朝理; 李海龙; 薛峰; 张炜; 郑小强

    2011-01-01

    目的 评估桥小脑角区(CPA)小型占位致继发性三叉神经痛的手术疗效.方法 回顾分析我科自2005年1月~2010年12月期间该类患者的临床资料,包括年龄、症状及体征、影像学表现、手术方式、疗效及并发症.结果 6年期间手术治疗三叉神经痛372例,其中CPA区小型病变(最大直径<3cm)致继发性三叉神经痛23例,约占6.2%;病种包括胆脂瘤12例、神经鞘瘤6例、脑膜瘤3例、蛛网膜囊肿2例;所有患者行乙状窦后入路显微镜下切除病变,3例另行三叉神经感觉根部分切断术;术后疼痛消失20例,面部麻木3例;术后并发症包括无菌性脑膜炎、脑脊液漏、颅内感染、短暂耳鸣及面瘫,均恢复,无死亡.随访1~5年,无疼痛复发.结论 CPA区小型占位所致继发性三叉神经痛患者由于病变小、易于全切,加之镜下暴露充分,手术疗效满意;术中若发现病变与三叉神经无确切关系,则需行微血管减压或三叉神经部分感觉根切断术.%Objective To evaluate the surgical outcome after resection of small cerebel-lopontine angle lesions resulted in secondary trigeminal neuralgia (TN). Methods Clinical data including age, symptom and sign, image manifestation, surgical modality, surgical outcome and complications in patients diagnosed secondary TN resulted from small cerebellopontine angle lesions are analyzed retrospectively between 2005. 1 and 2010. 12. Results Of 6 years duration, 372 cases of TN underwent operations. There were 23 cases of such kind (the largest diameter less than 3cm) accounting for 6. 2% among them which involved 12 cholesteatomas, 6 schwanno-mas, 3 meningiomas and 2 arachnoid cysts. All lesions were resected under microscope through retrosigmoid approach and additional partial sensory rhizotomy was performed in 3 cases. After operation, 20 cases got complete pain relief and the rest had facial numbness. Postoperative complications included aseptic

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

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    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.

  15. 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...

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

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    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.

  17. 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 ...

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

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    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).

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

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    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.

  20. 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.)

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

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    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.

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

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    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

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

    Science.gov (United States)

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

    1990-09-01

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

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

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    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.

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

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    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

  6. Late metastasis of breast adenocarcinoma into internal auditory canal and cerebellopontine angle: case report

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    Marques Edilson

    2002-01-01

    Full Text Available A case of metastasis of breast adenocarcinoma into the internal auditory canal (IAC and cerebellopontine angle (CPA is presented, which appeared 16 years after primary tumor had been treated by surgery and radiation therapy. The 66-year old patient was considered cured from the primary disease, when she started with a rapidly developing hearing loss and intermittent facial palsy. Magnetic resonance image (MRI displayed an intra- and extracanalicular tumor mass, which radiologically resembled a vestibular schwannoma. Surgery was performed and histopathological studies showed an adenocarcinoma compatible with breast origin. Metastasis is a rare occurrence within the IAC and CPA. Clinical history of severe facial palsy will rise suspicion of malignant tumor in spite of the radiological findings.

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

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    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

  8. 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.

  9. 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)

  10. 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)

  11. Trauma-induced auditory nerve degeneration due to cerebellopontine(CP) angle manipulations:clinical and experimental experience

    Institute of Scientific and Technical Information of China (English)

    Tetsuji Sekiya

    2004-01-01

    In order to investigate the pathophysiologic mechanisms responsible for trauma-induced hearing disturbances due to auditory nerve degeneration, we established for the first time a rat experimental model in which auditory nerve degeneration due to compression injury of the cerebellopontine (CP) angle portion of the auditory nerve can be quantitatively evaluated. In this paper, Ⅰ demonstrate our clinical experience in CP angle surgery and some of the results of our experiments performed onthis rat experimental model. Trauma-induced hearing loss in CP angle operations has long been regarded as a sort of unavoidable "natural course"and therefore hopeless.I believe that this pessimistic view should be challenged and changed through new approaches in scientific research.

  12. 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

  13. 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

  14. 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.

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

    Science.gov (United States)

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

    2015-10-01

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

  16. Clinical Use of Skull Tap Vestibular Evoked Myogenic Potentials for the Diagnoses of the Cerebellopontine Angle Tumor Patients

    Directory of Open Access Journals (Sweden)

    Erdem Yavuz

    2014-01-01

    Full Text Available Objective. To document our experiences using a new skull tapping induced Vestibular Evoked Myogenic Potentials (tap VEMPs technique combined with standard Auditory Vestibular Evoked Myogenic Potentials (AC VEMPs for advanced clinical assessment of cerebellopontine angle tumor (CPAT patients. Design and Study Sample. Three patients were selected in order to highlight observations shown in a larger patient population and to show the variability of the findings. Both tap VEMPs and AC VEMPs were acquired from the sternocleidomastoid muscle (SCM with EMG-based biofeedback and monitoring. Results. The usefulness of VEMPs was demonstrated, indicating the presence of a tumor and contributing additional information as to the involved nerve bundles in two out of the three cases. Conclusion. Due to the sensory organ dependency and related innervations differences, acquiring both AC VEMPs and tap VEMPs is likely to increase the probability of diagnosing CPATs and provide more information on the involved vestibular nerve bundles. This study demonstrates the feasibility of the possible expansion and combination of tap VEMPs and AC VEMPs techniques into a clinical diagnostic battery for advanced assessment of CPAT patients and its contribution as a guideline for the use of tap VEMPs in general.

  17. 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.)

  18. 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

  19. A Rare Case of Radiologically Not Distinguishable Coexistent Meningioma and Vestibular Schwannoma in the Cerebellopontine Angle – Case Report and Literature Review

    Directory of Open Access Journals (Sweden)

    Juergen Grauvogel

    2010-08-01

    Full Text Available Background: The simultaneous occurrence of cerebellopontine angle (CPA meningioma and vestibular schwannoma (VS in the absence of neurofibromatosis type 2 or history of irradiation is very rare. We report a case with coexistent CPA meningioma and VS, which were radiologically not distinguishable in preoperative imaging. Case Description: A 46-year-old female presented with acute hearing loss, tinnitus and gait ataxia. Otorhinolaryngological diagnostic workup and imaging studies showed an intra- and extrameatal homogenous contrast enhancing lesion. The neuroradiological diagnosis was VS. The patient was operated via the retrosigmoid approach. Intraoperatively two distinct tumors were found: a small, mainly intrameatally located VS and a larger meningioma originating from the dura of the petrous bone. Both tumors were completely microsurgically removed. The patient experienced no new neurological deficit after surgery; particularly facial nerve function was completely preserved. Histopathological examination revealed a fibromatous meningioma and a VS, respectively. Conclusions: The coincidental occurrence of CPA meningioma and VS is very rare. Careful interpretation of imaging studies before surgery is crucial. Even such rare cases should be kept in mind when discussing the therapeutic options with the patient. More studies are needed for a better understanding of mechanisms leading to multiple tumor growth.

  20. 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.

  1. 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.)

  2. 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.

  3. Cystic angiomatous meningioma in the cerebellopontine angle mimicking hemangioblastoma

    Directory of Open Access Journals (Sweden)

    Deb Prabal

    2010-01-01

    Full Text Available We hereby report an extremely unusual case of cystic angiomatous meningioma in the CPA region in a 58-year-old male patient. He presented with complaints of headache, repeated episodes of vomiting and increasing unsteadiness of gait. Neuroimaging showed a large multicystic left-sided tentorial tumor projecting into the cerebellum and CPA with contrast-enhancing peripheral solid rim. He underwent a left retromastoid craniectomy and total excision of the tumor. Histopathology revealed an angiomatous meningioma with predominant microvascular component and extensive cystic changes. Immunopositivity for epithelial membrane antigen (EMA, vimentin and S-100 protein proved vital in excluding a hemangioblastoma.

  4. 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.

  5. 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 ...

  6. Improving prediction of secondary structure, local backbone angles, and solvent accessible surface area of proteins by iterative deep learning.

    Science.gov (United States)

    Heffernan, Rhys; Paliwal, Kuldip; Lyons, James; Dehzangi, Abdollah; Sharma, Alok; Wang, Jihua; Sattar, Abdul; Yang, Yuedong; Zhou, Yaoqi

    2015-01-01

    Direct prediction of protein structure from sequence is a challenging problem. An effective approach is to break it up into independent sub-problems. These sub-problems such as prediction of protein secondary structure can then be solved independently. In a previous study, we found that an iterative use of predicted secondary structure and backbone torsion angles can further improve secondary structure and torsion angle prediction. In this study, we expand the iterative features to include solvent accessible surface area and backbone angles and dihedrals based on Cα atoms. By using a deep learning neural network in three iterations, we achieved 82% accuracy for secondary structure prediction, 0.76 for the correlation coefficient between predicted and actual solvent accessible surface area, 19° and 30° for mean absolute errors of backbone φ and ψ angles, respectively, and 8° and 32° for mean absolute errors of Cα-based θ and τ angles, respectively, for an independent test dataset of 1199 proteins. The accuracy of the method is slightly lower for 72 CASP 11 targets but much higher than those of model structures from current state-of-the-art techniques. This suggests the potentially beneficial use of these predicted properties for model assessment and ranking.

  7. Economic value of angling on the Colorado River at Lees Ferry: Using secondary data to estimate the influence of seasonality

    Science.gov (United States)

    Bair, Lucas S.; Rogowski, David L.; Neher, Chris

    2016-01-01

    Glen Canyon Dam (GCD) on the Colorado River in northern Arizona provides water storage, flood control, and power system benefits to approximately 40 million people who rely on water and energy resources in the Colorado River basin. Downstream resources (e.g., angling, whitewater floating) in Glen Canyon National Recreation Area (GCNRA) and Grand Canyon National Park are impacted by the operation of GCD. The GCD Adaptive Management Program was established in 1997 to monitor and research the effects of dam operations on the downstream environment. We utilized secondary survey data and an individual observation travel cost model to estimate the net economic benefit of angling in GCNRA for each season and each type of angler. As expected, the demand for angling decreased with increasing travel cost; the annual value of angling at Lees Ferry totaled US$2.7 million at 2014 visitation levels. Demand for angling was also affected by season, with per-trip values of $210 in the summer, $237 in the spring, $261 in the fall, and $399 in the winter. This information provides insight into the ways in which anglers are potentially impacted by seasonal GCD operations and adaptive management experiments aimed at improving downstream resource conditions.

  8. 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.

  9. 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

  10. 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.

  11. 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...

  12. Suppression of xylan endotransglycosylase PtxtXyn10A affects cellulose microfibril angle in secondary wall in aspen wood.

    Science.gov (United States)

    Derba-Maceluch, Marta; Awano, Tatsuya; Takahashi, Junko; Lucenius, Jessica; Ratke, Christine; Kontro, Inkeri; Busse-Wicher, Marta; Kosik, Ondrej; Tanaka, Ryo; Winzéll, Anders; Kallas, Åsa; Leśniewska, Joanna; Berthold, Fredrik; Immerzeel, Peter; Teeri, Tuula T; Ezcurra, Ines; Dupree, Paul; Serimaa, Ritva; Mellerowicz, Ewa J

    2015-01-01

    Certain xylanases from family GH10 are highly expressed during secondary wall deposition, but their function is unknown. We carried out functional analyses of the secondary-wall specific PtxtXyn10A in hybrid aspen (Populus tremula × tremuloides). PtxtXyn10A function was analysed by expression studies, overexpression in Arabidopsis protoplasts and by downregulation in aspen. PtxtXyn10A overexpression in Arabidopsis protoplasts resulted in increased xylan endotransglycosylation rather than hydrolysis. In aspen, the enzyme was found to be proteolytically processed to a 68 kDa peptide and residing in cell walls. Its downregulation resulted in a corresponding decrease in xylan endotransglycosylase activity and no change in xylanase activity. This did not alter xylan molecular weight or its branching pattern but affected the cellulose-microfibril angle in wood fibres, increased primary growth (stem elongation, leaf formation and enlargement) and reduced the tendency to form tension wood. Transcriptomes of transgenic plants showed downregulation of tension wood related genes and changes in stress-responsive genes. The data indicate that PtxtXyn10A acts as a xylan endotransglycosylase and its main function is to release tensional stresses arising during secondary wall deposition. Furthermore, they suggest that regulation of stresses in secondary walls plays a vital role in plant development.

  13. 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

  14. 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.

  15. Small-angle X-ray scattering: a bridge between RNA secondary structures and three-dimensional topological structures

    Energy Technology Data Exchange (ETDEWEB)

    Fang, Xianyang [National Inst. of Health (NIH), Bethesda, MD (United States). National Cancer Inst., NCI Small Angle X-ray Scattering Core Facility; Stagno, Jason R. [National Inst. of Health (NIH), Bethesda, MD (United States). National Cancer Inst., Protein-Nucleic Acid Interaction Section, Structural Biophysics Lab.; Bhandari, Yuba R. [National Inst. of Health (NIH), Bethesda, MD (United States). National Cancer Inst., Protein-Nucleic Acid Interaction Section, Structural Biophysics Lab.; Zuo, Xiaobing [Argonne National Lab. (ANL), Argonne, IL (United States). Advanced Photon Source (APS); Wang, Yun-Xing [National Inst. of Health (NIH), Bethesda, MD (United States). National Cancer Inst., NCI Small Angle X-ray Scattering Core Facility; National Inst. of Health (NIH), Bethesda, MD (United States). National Cancer Inst., Protein-Nucleic Acid Interaction Section, Structural Biophysics Lab.

    2015-02-01

    Whereas the structures of small to medium-sized well folded RNA molecules often can be determined by either X-ray crystallography or NMR spectroscopy, obtaining structural information for large RNAs using experimental, computational, or combined approaches remains a major interest and challenge. RNA is very sensitive to small-angle X-ray scattering (SAXS) due to high electron density along phosphate-sugar backbones, whose scattering contribution dominates SAXS intensity. For this reason, SAXS is particularly useful in obtaining global RNA structural information that outlines backbone topologies and, therefore, molecular envelopes. Such information is extremely valuable in bridging the gap between the secondary structures and three-dimensional topological structures of RNAmolecules, particularly those that have proven difficult to study using other structuredetermination methods. Here we review published results of RNA topological structures derived from SAXS data or in combination with other experimental data, as well as details on RNA sample preparation for SAXS experiments.

  16. 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.

  17. 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.

  18. Detection and alignment of 3D domain swapping proteins using angle-distance image-based secondary structural matching techniques.

    Directory of Open Access Journals (Sweden)

    Chia-Han Chu

    Full Text Available This work presents a novel detection method for three-dimensional domain swapping (DS, a mechanism for forming protein quaternary structures that can be visualized as if monomers had "opened" their "closed" structures and exchanged the opened portion to form intertwined oligomers. Since the first report of DS in the mid 1990s, an increasing number of identified cases has led to the postulation that DS might occur in a protein with an unconstrained terminus under appropriate conditions. DS may play important roles in the molecular evolution and functional regulation of proteins and the formation of depositions in Alzheimer's and prion diseases. Moreover, it is promising for designing auto-assembling biomaterials. Despite the increasing interest in DS, related bioinformatics methods are rarely available. Owing to a dramatic conformational difference between the monomeric/closed and oligomeric/open forms, conventional structural comparison methods are inadequate for detecting DS. Hence, there is also a lack of comprehensive datasets for studying DS. Based on angle-distance (A-D image transformations of secondary structural elements (SSEs, specific patterns within A-D images can be recognized and classified for structural similarities. In this work, a matching algorithm to extract corresponding SSE pairs from A-D images and a novel DS score have been designed and demonstrated to be applicable to the detection of DS relationships. The Matthews correlation coefficient (MCC and sensitivity of the proposed DS-detecting method were higher than 0.81 even when the sequence identities of the proteins examined were lower than 10%. On average, the alignment percentage and root-mean-square distance (RMSD computed by the proposed method were 90% and 1.8Å for a set of 1,211 DS-related pairs of proteins. The performances of structural alignments remain high and stable for DS-related homologs with less than 10% sequence identities. In addition, the quality of its

  19. Detection and alignment of 3D domain swapping proteins using angle-distance image-based secondary structural matching techniques.

    Science.gov (United States)

    Chu, Chia-Han; Lo, Wei-Cheng; Wang, Hsin-Wei; Hsu, Yen-Chu; Hwang, Jenn-Kang; Lyu, Ping-Chiang; Pai, Tun-Wen; Tang, Chuan Yi

    2010-10-14

    This work presents a novel detection method for three-dimensional domain swapping (DS), a mechanism for forming protein quaternary structures that can be visualized as if monomers had "opened" their "closed" structures and exchanged the opened portion to form intertwined oligomers. Since the first report of DS in the mid 1990s, an increasing number of identified cases has led to the postulation that DS might occur in a protein with an unconstrained terminus under appropriate conditions. DS may play important roles in the molecular evolution and functional regulation of proteins and the formation of depositions in Alzheimer's and prion diseases. Moreover, it is promising for designing auto-assembling biomaterials. Despite the increasing interest in DS, related bioinformatics methods are rarely available. Owing to a dramatic conformational difference between the monomeric/closed and oligomeric/open forms, conventional structural comparison methods are inadequate for detecting DS. Hence, there is also a lack of comprehensive datasets for studying DS. Based on angle-distance (A-D) image transformations of secondary structural elements (SSEs), specific patterns within A-D images can be recognized and classified for structural similarities. In this work, a matching algorithm to extract corresponding SSE pairs from A-D images and a novel DS score have been designed and demonstrated to be applicable to the detection of DS relationships. The Matthews correlation coefficient (MCC) and sensitivity of the proposed DS-detecting method were higher than 0.81 even when the sequence identities of the proteins examined were lower than 10%. On average, the alignment percentage and root-mean-square distance (RMSD) computed by the proposed method were 90% and 1.8Å for a set of 1,211 DS-related pairs of proteins. The performances of structural alignments remain high and stable for DS-related homologs with less than 10% sequence identities. In addition, the quality of its hinge loop

  20. A STUDY OF THE INCID ENCE OF CEREBELLOPON TINE ANGLE TUMORS AND THEIR MAN AGEMENT IN A TERTIAR Y CARE HOSPITAL

    Directory of Open Access Journals (Sweden)

    Raja Sekhar Kennedy

    2015-04-01

    Full Text Available INTRODUCTI ON : Cerebellopontine angle tumors are a surgical challenge to many neurosurgeons who want to operate in this space. Although most of these tumors are benign, they are a challenge because of the complex anatomy and important neurovascular structures that traver se this space. Most common cerebellopontine angle tumor is vestibular schwannoma. The management of these cases is essentially surgical. There has been a change in the surgical strategy over the years from simple intratumoral decompression to complete micr osurgical excision, to facial nerve preservation and hearing preservation. AIMS AND OBJECTIVES: To study the clinical and radiological characteristics, know the pathological types and determine the surgical resectability and outcome of cerebellopontine ang le tumor. MATERIALS AND METHOD : It is a prospective study done in the department of Neurosurgery, King George Hospital, Visakhapatnam, Andhra Pradesh. It is a Tertiary Care Hospital. 50 patients diagnosed with cerebellopontine angle tumor were recruited in to the study and were managed. RESULTS : 50 cases of cerebellopontine angle tumors accounting for 11% of all intracranial space occupying lesions, of which vestibular schwannoma alone constituted 10%. Most of the tumors were large or giant tumors. Total resection was done in 74% of vestibular sch wannoma and 50% of meningiomas. Anatomical preservation of facial nerve was achieved in 67% of patients. CONCLUSION : C erebellopontine angle tumors show high incidence from 3 rd to 5 th decade with common symptoms being hearing loss and ataxia. Most of the pa tients presented at a delayed stage with large to giant tumors with no useful hearing. Complete excision of tumor preserving facial and lower cranial nerve function is the goal. Postoperative cerebrospinal fluid leak can be managed effectively with conserv ative therapy

  1. 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.

  2. 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...

  3. 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

  4. 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.

  5. [Bilateral cerebellopontine arachnoid cyst].

    Science.gov (United States)

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

    2016-06-16

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

  6. Measurements and Monte Carlo calculations of forward-angle secondary-neutron-production cross-sections for 137 and 200 MeV proton-induced reactions in carbon

    Energy Technology Data Exchange (ETDEWEB)

    Iwamoto, Yosuke, E-mail: iwamoto.yosuke@jaea.go.jp [Japan Atomic Energy Agency, 2-4 Shirakata-Shirane, tokai, naka Ibaraki 319-1195 (Japan); Hagiwara, Masayuki [High Energy Accelerator Research Organization (Japan); Matsumoto, Tetsuro; Masuda, Akihiko [National Institute of Advanced Industrial Science and Technology (Japan); Iwase, Hiroshi [High Energy Accelerator Research Organization (Japan); Yashima, Hiroshi [Research Reactor Institute, Kyoto University (Japan); Shima, Tatsushi; Tamii, Atsushi [Research Center for Nuclear Physics, Osaka University (Japan); Nakamura, Takashi [Cyclotron and Radioisotope Center, Tohoku University, Institute of Technology, Shimizu Corporation (Japan)

    2012-10-21

    Secondary neutron-production double-differential cross-sections (DDXs) have been measured from interactions of 137 MeV and 200 MeV protons in a natural carbon target. The data were measured between 0 Degree-Sign and 25 Degree-Sign in the laboratory. DDXs were obtained with high energy resolution in the energy region from 3 MeV up to the maximum energy. The experimental data of 137 MeV protons at 10 Degree-Sign and 25 Degree-Sign were in good agreement with that of 113 MeV protons at 7.5 Degree-Sign and 30 Degree-Sign at LANSCE/WNR in the energy region below 80 MeV. Benchmark calculations were carried out with the PHITS code using the evaluated nuclear data files of JENDL/HE-2007 and ENDF/B-VII, and the theoretical models of Bertini-GEM and ISOBAR-GEM. For the 137 MeV proton incidence, calculations using JENDL/HE-2007 generally reproduced the shape and the intensity of experimental spectra well including the ground state of the {sup 12}N state produced by the {sup 12}C(p,n){sup 12}N reaction. For the 200 MeV proton incidence, all calculated results underestimated the experimental data by the factor of two except for the calculated result using ISOBAR model. ISOBAR predicts the nucleon emission to the forward angles qualitatively better than the Bertini model. These experimental data will be useful to evaluate the carbon data and as benchmark data for investigating the validity of the Monte Carlo simulation for the shielding design of accelerator facilities.

  7. 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.

  8. 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

  9. 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

  10. 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.

  11. Virtual reality in clinical teaching of cerebellopontine angle%浅谈虚拟现实在桥脑小脑角区临床教学中的应用

    Institute of Scientific and Technical Information of China (English)

    崔高宇; 冯华

    2010-01-01

    @@ 微创神经外科(minimally invasive neurosurgery)核心内容是在最大程度处理病变的同时要尽最大可能保护神经组织的结构和功能.因此要求对中枢神经系统的局部解剖学知识认识和掌握有很高的要求.

  12. 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…

  13. Angles as probabilities

    CERN Document Server

    Feldman, David V

    2008-01-01

    We use a probabilistic interpretation of solid angles to generalize the well-known fact that the inner angles of a triangle sum to 180 degrees. For the 3-dimensional case, we show that the sum of the solid inner vertex angles of a tetrahedron T, divided by 2*pi, gives the probability that an orthogonal projection of T onto a random 2-plane is a triangle. More generally, it is shown that the sum of the (solid) inner vertex angles of an n-simplex S, normalized by the area of the unit (n-1)-hemisphere, gives the probability that an orthogonal projection of S onto a random hyperplane is an (n-1)-simplex. Applications to more general polytopes are treated briefly, as is the related Perles-Shephard proof of the classical Gram-Euler relations.

  14. 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.

  15. [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

  16. Angles in hyperbolic lattices

    DEFF Research Database (Denmark)

    Södergren, Carl Anders; Risager, Morten S.

    2015-01-01

    It is well known that the angles in a lattice acting on hyperbolic n -space become equidistributed. In this paper we determine a formula for the pair correlation density for angles in such hyperbolic lattices. Using this formula we determine, among other things, the asymptotic behavior...... of the density function in both the small and large variable limits. This extends earlier results by Boca, Pasol, Popa and Zaharescu and Kelmer and Kontorovich in dimension 2 to general dimension n . Our proofs use the decay of matrix coefficients together with a number of careful estimates, and lead...

  17. 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...

  18. 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...... method appears to be of minimal practical use in forensic anthropology and archeology. © 2013 American Academy of Forensic Sciences....

  19. 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...

  20. [Secondary dyslipidemias].

    Science.gov (United States)

    Vargová, V; Pytliak, M; Mechírová, V

    2012-03-01

    Dyslipidemias rank among the most important preventabile factors of atherogenesis and its progression. This topic is increasingly being discussed as e.g. more than 50% of Slovak population die on atherosclerotic complications. According to etiology we distinguish primary dyslipidemias with strictly genetic background and secondary ones with origin in other disease or pathological state. Secondary dyslipidemias accompany various diseases, from common (endocrinopathies, renal diseases etc) to rare ones (thesaurismosis etc.) and represents one of symptoms of these diseases. Apart from particular clinical follow up of diagnosed dysipidemias, basic screening and secondary causes as well as treatment due to updated guidelines is recuired. In this review we present the most frequent dyslipidemias of clinical practice.

  1. 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

  2. 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.

  3. Angle-deviation optical profilometer

    Institute of Scientific and Technical Information of China (English)

    Chen-Tai Tan; Yuan-Sheng Chan; Zhen-Chin Lin; Ming-Hung Chiu

    2011-01-01

    @@ We propose a new optical profilometer for three-dimensional (3D) surface profile measurement in real time.The deviation angle is based on geometrical optics and is proportional to the apex angle of a test plate.Measuring the reflectivity of a parallelogram prism allows detection of the deviation angle when the beam is incident at the nearby critical angle. The reflectivity is inversely proportional to the deviation angle and proportional to the apex angle and surface height. We use a charge-coupled device (CCD) camera at the image plane to capture the reflectivity profile and obtain the 3D surface profile directly.%We propose a new optical profilometer for three-dimensional (3D) surface profile measurement in real time.The deviation angle is based on geometrical optics and is proportional to the apex angle of a test plate.Measuring the refiectivity of a parallelogram prism allows detection of the deviation angle when the beam is incident at the nearby critical angle. The refiectivity is inversely proportional to the deviation angle and proportional to the apex angle and surface height. We use a charge-coupled device (CCD) camera at the image plane to capture the refiectivity profile and obtain the 3D surface profile directly.

  4. 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

  5. Two Comments on Bond Angles

    Science.gov (United States)

    Glaister, P.

    1997-09-01

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

  6. The Semiotic and Conceptual Genesis of Angle

    Science.gov (United States)

    Tanguay, Denis; Venant, Fabienne

    2016-01-01

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

  7. 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.

  8. Angle independent velocity spectrum determination

    DEFF Research Database (Denmark)

    2014-01-01

    An ultrasound imaging system (100) includes a transducer array (102) that emits an ultrasound beam and produces at least one transverse pulse-echo field that oscillates in a direction transverse to the emitted ultrasound beam and that receive echoes produced in response thereto and a spectral vel...... velocity estimator (110) that determines a velocity spectrum for flowing structure, which flows at an angle of 90 degrees and flows at angles less than 90 degrees with respect to the emitted ultrasound beam, based on the received echoes....

  9. Large angle measurement by interferometry

    Science.gov (United States)

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

    1995-03-01

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

  10. 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,…

  11. 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

  12. An Angle Criterion for Riesz Bases

    DEFF Research Database (Denmark)

    Lindner, Alexander M; Bittner, B.

    1999-01-01

    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.......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....

  13. 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.)

  14. Gaia basic angle monitoring system

    Science.gov (United States)

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

    2013-09-01

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

  15. LHC Report: playing with angles

    CERN Multimedia

    Mike Lamont for the LHC team

    2016-01-01

    Ready (after a machine development period), steady (running), go (for a special run)!   The crossing angles are an essential feature of the machine set-up. They have to be big enough to reduce the long-range beam-beam effect. The LHC has recently enjoyed a period of steady running and managed to set a new record for “Maximum Stable Luminosity Delivered in 7 days” of 3.29 fb-1 between 29 August and 4 September. The number of bunches per beam remains pegged at 2220 because of the limitations imposed by the SPS beam dump. The bunch population is also somewhat reduced due to outgassing near one of the injection kickers at point 8. Both limitations will be addressed during the year-end technical stop, opening the way for increased performance in 2017. On 10 and 11 September, a two day machine development (MD) period took place. The MD programme included a look at the possibility of reducing the crossing angle at the high-luminosity interaction points. The crossing angles are an ess...

  16. 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.

  17. 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...

  18. 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.

  19. 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 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....

  20. Device for Measuring Landslide Critical Angle

    Institute of Scientific and Technical Information of China (English)

    Li Xueling; Xia Weisheng; Huang Daoyou; Yu Yun

    2016-01-01

    The mountain landslide has high destructive effects, discussion of its landslide critical angle has always been one of the major concerns, and we designed a system that can automatically measure the landslide critical angle. This equipment consists of the

  1. 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...

  2. 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...

  3. 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...

  4. 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...

  5. 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.

  6. 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.

  7. 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.

  8. 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...

  9. 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

  10. 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

  11. Bacteriophage secondary infection

    Institute of Scientific and Technical Information of China (English)

    Stephen; T; Abedon

    2015-01-01

    Phages are credited with having been first described in what we now, officially, are commemorating as the 100 th anniversary of their discovery. Those one-hundred years of phage history have not been lacking in excitement, controversy, and occasional convolution. One such complication is the concept of secondary infection, which can take on multiple forms with myriad consequences. The terms secondary infection and secondary adsorption, for example, can be used almost synonymously to describe virion interaction with already phage-infected bacteria, and which can result in what are described as superinfection exclusion or superinfection immunity. The phrase secondary infection also may be used equivalently to superinfection or coinfection, with each of these terms borrowed from medical microbiology, and can result in genetic exchange between phages, phage-on-phage parasitism, and various partial reductions in phage productivity that have been termed mutual exclusion, partial exclusion, or the depressor effect. Alternatively, and drawing from epidemiology, secondary infection has been used to describe phage population growth as that can occur during active phage therapy as well as upon phage contamination of industrial ferments. Here primary infections represent initial bacterial population exposure to phages while consequent phage replication can lead to additional, that is, secondary infections of what otherwise are not yet phage-infected bacteria. Here I explore the varying meanings and resultant ambiguity that has been associated with the term secondary infection. I suggest in particular that secondary infection, as distinctly different phenomena, can in multiple ways influence the success of phage-mediated biocontrol of bacteria, also known as, phage therapy.

  12. 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)

  13. 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....

  14. 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....

  15. Acute angle closure glaucoma following ileostomy surgery

    Directory of Open Access Journals (Sweden)

    Mariana Meirelles Lopes

    2015-02-01

    Full Text Available Angle-closure glaucoma can be induced by drugs that may cause pupillary dilatation. We report a case of a patient that developed bilateral angle closure glaucoma after an ileostomy surgery because of systemic atropine injection. This case report highlights the importance of a fast ophthalmologic evaluation in diseases with ocular involvement in order to make accurate diagnoses and appropriate treatments.

  16. 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.

  17. Secondary pool boiling effects

    Science.gov (United States)

    Kruse, C.; Tsubaki, A.; Zuhlke, C.; Anderson, T.; Alexander, D.; Gogos, G.; Ndao, S.

    2016-02-01

    A pool boiling phenomenon referred to as secondary boiling effects is discussed. Based on the experimental trends, a mechanism is proposed that identifies the parameters that lead to this phenomenon. Secondary boiling effects refer to a distinct decrease in the wall superheat temperature near the critical heat flux due to a significant increase in the heat transfer coefficient. Recent pool boiling heat transfer experiments using femtosecond laser processed Inconel, stainless steel, and copper multiscale surfaces consistently displayed secondary boiling effects, which were found to be a result of both temperature drop along the microstructures and nucleation characteristic length scales. The temperature drop is a function of microstructure height and thermal conductivity. An increased microstructure height and a decreased thermal conductivity result in a significant temperature drop along the microstructures. This temperature drop becomes more pronounced at higher heat fluxes and along with the right nucleation characteristic length scales results in a change of the boiling dynamics. Nucleation spreads from the bottom of the microstructure valleys to the top of the microstructures, resulting in a decreased surface superheat with an increasing heat flux. This decrease in the wall superheat at higher heat fluxes is reflected by a "hook back" of the traditional boiling curve and is thus referred to as secondary boiling effects. In addition, a boiling hysteresis during increasing and decreasing heat flux develops due to the secondary boiling effects. This hysteresis further validates the existence of secondary boiling effects.

  18. 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.)

  19. Prediction of nonregular secondary structures of proteins based on wavelet analysis

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The secondary structures of proteins fall into two classes: regular structure and nonregular structure. Helices and sheets are termed "regular" structures because their residues have repeating main-chain torsion angles, and their backbone N-H and C-O groups are arranged in a periodic pattern of hydrogen bonding. In contrast, the remaining structures with nonrepeating backbone torsion angles are called nonregular secondary structures. In this note, we performed an extensive sequence analysis of nonregular secondary structures and showed that these nonregular parts could be effectively predicted by continuous wavelet transform.

  20. Experimental Studies on The Mechanism and COntrol of Secondary Flow Losses in Turbine Cascades

    Institute of Scientific and Technical Information of China (English)

    WangZhongqi; HanWanjin; 等

    1992-01-01

    This paper summarizes the results of the authors' 4 year experimental studies on the secondary flow losses in turbine cascades.cascade wind tunnel experiments were carried out concerning the influence of aspect rations,incidence,turning angles and outer endwall divergent angles in order to unveil the evolution mechanism of secondary flow losses in turbine cascades without end clearance.Some methods for controlling the secondary flows are investigated including the blade leaning,blade cambering,endwall convergence and leading edge extension at two ends of the blade.

  1. 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.

  2. 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

  3. 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

  4. 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 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 ... of osteoarthritis 0 or 1. All patients had a magnetic resonance arthrography (MRA) performed. The MRA was assessed for labral pathology in terms of degeneration, hypertrophic changes, tears and paralabral cysts. Labral lesions were graded according to the Czerny classification. Findings / Results: In the group...

  5. 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

  6. Phase-angle controller for Stirling engines

    Science.gov (United States)

    Mcdougal, A. R. (Inventor)

    1980-01-01

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

  7. Bite Angle Effects in Hydroformylation Catalysis

    Institute of Scientific and Technical Information of China (English)

    van LEEUWEN

    2001-01-01

    Recent advances in rhodium catalyzed hydroformylation using xanthene-based ligands will be reviewed.The calculated natural bite angles of the ligands discussed are in the range 100-123℃ While the general trend is clear-higher 1:b ratios at wider angles, small changes in the bite angle do not exhibit a regular effect on the selectivity of the reaction.The same is true for the rate of CO dissociation;the larger the rate of the CO dissociation, the larger the rate of hydroformylation, but for small changes the effects do not comply with this rule.

  8. 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.

  9. Secondary drowning in children.

    Science.gov (United States)

    Pearn, J H

    1980-10-25

    Secondary drowning (and near-drowning) is one of the post-immersion respiratory syndromes. It is defined as deterioration of pulmonary function that follows deficient gas exchange due to loss or inactivation of surfactant. A review of 94 consecutive cases of near-drowning in childhood showed that this syndrome occurred in five (5%) cases. Its onset was usually rapid and characterised by a latent period of one to 48 hours of relative respiratory well-being. It occurred more rapidly after immersion in fresh water. The two children immersed in salt water died of secondary drowning, while the three immersed in fresh water recovered completely. If it is anticipated, recognised, and treated vigorously prognosis of secondary drowning is good in fresh water cases but bad after salt water immersion.

  10. 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.

  11. 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

  12. Fluid dynamics in airway bifurcations: II. Secondary currents.

    Science.gov (United States)

    Martonen, T B; Guan, X; Schreck, R M

    2001-04-01

    As the second component of a systematic investigation on flows in bifurcations reported in this journal, this work focused on secondary currents. The first article addressed primary flows and the third discusses localized conditions (both in this issue). Secondary flow patterns were studied in two lung bifurcation models (Schreck, 1972) using FIDAP with the Cray T90 supercomputer. The currents were examined at different prescribed distances distal to the carina. Effects of inlet conditions, Reynolds numbers, and diameter ratios and orientations of airways were addressed. The secondary currents caused by the presence of the carina and inclination of the daughter tubes exhibited symmetric, multivortex patterns. The intensities of the secondary currents became stronger for larger Reynolds numbers and larger angles of bifurcation.

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. Lateral angle and cranial base sexual dimorphism

    DEFF Research Database (Denmark)

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

    2016-01-01

    SUMMARY: Previous studies have yielded very different results in sex estimation based on measurements of the lateral angle (LA) of the temporal bone. The purpose of this study was to, first, investigate if the bad results obtained by the LA method could be due to the methodology and then, second......, 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 applied......, and by use of a new method, using a "virtual cast". The cranial base was quantified by placing 12 landmarks in the posterior fossa. Procrustes analysis, principal component analysis, discriminant analysis and cross-validation test were performed. The "cast method" was found to be less accurate than...

  18. Modification of Slenderness Coefficient of Angle Steels

    Institute of Scientific and Technical Information of China (English)

    刘红燕; 李志业

    2004-01-01

    To provide information for amendment to Technical Specifications for Power Transmission Towers (SDGJ94-90), the critical loads of typical compressed angle steels was calculated. The correlation of buckling loads and slenderness of compressed angle steels was obtained with regression. A new slenderness coefficient equation was proposed based on the result of the correlation. A practical measure to ensure good result in nonlinear solution using Arch-length method is put forward.

  19. Wide Angle Effects in Future Galaxy Surveys

    OpenAIRE

    Yoo, Jaiyul; Seljak, Uros

    2013-01-01

    Current and future galaxy surveys cover a large fraction of the entire sky with a significant redshift range, and the recent theoretical development shows that general relativistic effects are present in galaxy clustering on very large scales. This trend has renewed interest in the wide-angle effect in galaxy clustering measurements, in which the distant-observer approximation is often adopted. Using the full wide-angle formula for computing the redshift-space correlation function, we show th...

  20. 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...

  1. 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...

  2. Winding angles of long lattice walks

    Science.gov (United States)

    Hammer, Yosi; Kantor, Yacov

    2016-07-01

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

  3. 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…

  4. Modernising Portugal's Secondary Schools

    Science.gov (United States)

    Heitor, Teresa V.

    2008-01-01

    Portugal has a total of 477 public secondary schools. Some date from the end of the 19th century but the majority were built after 1970, reflecting the period of expansion in the school network and the extension of compulsory schooling. The schools are heterogeneous in terms of building types, architectural features and quality. An assessment of…

  5. 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;…

  6. Scheduling the Secondary School.

    Science.gov (United States)

    Dempsey, Richard A.; Traverso, Henry P.

    This "how-to-do-it" manual on the intricacies of school scheduling offers both technical information and common sense advice about the process of secondary school scheduling. The first of six chapters provides an overview of scheduling; chapter 2 examines specific considerations for scheduling; chapter 3 surveys the scheduling models and their…

  7. 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…

  8. Secondary Education in Liechtenstein.

    Science.gov (United States)

    Messner, Franz

    This booklet provides a brief description of secondary education in Liechtenstein. The publication is part of a series that seeks to make the public aware of the education systems and traditions in all signatory states to the European Cultural Convention and to outline the essential problems these systems presently are facing. This short booklet…

  9. 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

  10. 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

  11. Secondary Electron Interference from Trigonal Warping in Clean Carbon Nanotubes

    Science.gov (United States)

    Dirnaichner, A.; del Valle, M.; Götz, K. J. G.; Schupp, F. J.; Paradiso, N.; Grifoni, M.; Strunk, Ch.; Hüttel, A. K.

    2016-10-01

    We investigate Fabry-Perot interference in an ultraclean carbon nanotube resonator. The conductance shows a clear superstructure superimposed onto conventional Fabry-Perot oscillations. A sliding average over the fast oscillations reveals a characteristic slow modulation of the conductance as a function of the gate voltage. We identify the origin of this secondary interference in intervalley and intravalley backscattering processes which involve wave vectors of different magnitude, reflecting the trigonal warping of the Dirac cones. As a consequence, the analysis of the secondary interference pattern allows us to estimate the chiral angle of the carbon nanotube.

  12. Ultrastructural Observations of The Anterior Chamber Angle Tissues in Congenital Glaucoma

    Institute of Scientific and Technical Information of China (English)

    1994-01-01

    Eighteen trabeculectomy specimens of congenital glaucoma were examined by light and transimssion electron microscopy. The results showed that the primary anomalies in congenital glaucoma included the developmental defects of trabecular meshwork, excessive collagen fibrils in the trabecular matrix, shifting forward of ciliary muscle fibres and persistent mesenchymal tissues in the anterior-chamber angle. The authors also pointed out the importance of the secondary lesions of the trabecular meshwork in th...

  13. 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 VH, the secondary rotations are single-periodic with no signs of chaotic rotation and their periods are constant on timescales from weeks to years. The secondary equatorial elongations show an upper limit of a2 /b2 ∼ 1.5 . The lack of 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

  14. 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.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1999-10-14

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

  16. 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.

  17. Phaco-endocycloplasty: A novel technique for management of ring iridociliary cyst presenting as acute angle closure

    Directory of Open Access Journals (Sweden)

    Vanita Pathak-Ray

    2016-01-01

    Full Text Available Iridociliary cysts of pigment epithelium are rare, ring cysts being rarer still, and usually benign in their clinical course. Presented here is a case of ring iridociliary cyst that resulted in secondary synechial angle closure with an acutely elevated intraocular pressure, refractory to medical treatment. Primary endocycloplasty and cataract extraction with implant were used successfully to manage the case.

  18. Secondary victims of rape

    DEFF Research Database (Denmark)

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

    2012-01-01

    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......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...... of traumatization, and it was estimated that approximately one quarter of the respondents suffered from posttraumatic stress syndrome (PTSD). Degree of traumatization was associated with a more recent assault, higher efforts to support the PV, recurrent thoughts about having been able to prevent the assault, a lack...

  19. 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

  20. 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...

  1. 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

  2. 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.

  3. 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.

  4. 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.

  5. Bicycle helmet ventilation and comfort angle dependence.

    Science.gov (United States)

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

    2004-09-01

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

  6. Flocking and invariance of velocity angles.

    Science.gov (United States)

    Liu, Le; Huang, Lihong; Wu, Jianhong

    2016-04-01

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

  7. MANDARIN SECONDARY PREDICATES

    Directory of Open Access Journals (Sweden)

    Ryosuke Shibagaki

    2010-06-01

    Full Text Available In the first part, I provide some data of secondary predicates in English and Mandarin on consequence-depictives (SUBJ-oriented and resultatives (OBJ-oriented, which adopt an intransitive verb/adjective for their secondary predicate. In the second half, I present an account of the linking issue on “resultative” compound predicates in Mandarin Chinese, building on the LFG/LMT work of Her (2007, who assumed that the argument structures of each predicate merge to give a composite structure, which determines whether a resultative sentence is semantically causative or not, and from which the arguments link to grammatical functions. I argue here that the facts require a more articulated semantics, for unlike Her’s analysis, the determination of causativity and the linking of the arguments of the two predicates is fully an issue of semantics; specifically, I argue that there are two types of secondary predicates in terms of their semantics, namely those with internally- and externally-caused changes of state (see Levin and Rappaport Hovav: 1995, McKoon and Macfarland: 2000, which are respectively “indirect-causative” and “direct-causative”; causativity should be categorised into three types, non-causative, indirect-causative, and direct causative. I further argue that the argument undergoing internally-caused change always links to Actor and that the one undergoing externally-caused change (a truly “affected” argument always links to Undergoer.

  8. 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.

  9. 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...

  10. 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

  11. 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.

  12. 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)

  13. Wind Turbine Blade with Angled Girders

    DEFF Research Database (Denmark)

    2011-01-01

    The present invention relates to a reinforced blade for a wind turbine, particularly to a blade having a new arrangement of two or more girders in the blade, wherein each of the girders is connected to the upper part and the lower part of the shell and forms an angle with another girder thereby...

  14. A Method for Measuring a Plane Angle.

    Science.gov (United States)

    Roberts, George D.; Roberts, G. Gilbert

    1978-01-01

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

  15. 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

  16. 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

  17. Discharge Coefficient of 3-in-1 Hole with Various Inclination Angle and Hole Pitch

    Institute of Scientific and Technical Information of China (English)

    Li Guangchao; Zhu Huiren; Fan Huiming

    2008-01-01

    Discharge coefficients of 3-in- 1 hole of three inclination angles and three spacing between holes are presented which described the discharge behavior of a row of holes. The inlet and outlet of the 3-in-1 hole both have a 15° lateral expansion. The flow conditions considered are mainstream turbulence intensities and density ratios of secondary flow to mainstream. The momentum flux ratios varied in the range froom 1 to 4. The comparison is made of the discharge coefficients of three shaped holes to find an optimal hole with low flow loss. The results show that the discharge coefficients of 3-in-1 hole are highest in three shaped holes and therefore this article is focused on the measurements of discharge coefficients of 3-in-1 hole for various geometries and aerodynamic parameters. The measured results of 3-in-1 hole indicate that turbulence intensities, density ratios and momentum flux ratios have weak influence on discharge coefficients for inclination angle of 20°. The high turbulence intensity yields the small discharge coefficients for inclination angle of 45° and 90°.The increased both momentum flux ratios and density ratios lead to the increased discharge coefficients for inclination angle of 45° and 90°. The increased inclination angle causes the rapidly increased discharge coefficients. There is a weak dependence of discharge coefficients on hole pitches.

  18. 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

  19. [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

  20. 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.

  1. 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.

  2. 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.

  3. Experimental Validation of the Invariance of Electrowetting Contact Angle Saturation

    NARCIS (Netherlands)

    Chevalliot, S.; Dhindsa, M.; Kuiper, S.; Heikenfeld, J.

    2011-01-01

    Basic electrowetting theory predicts that a continued increase in applied voltage will allow contact angle modulation to zero degrees. In practice, the effect of contact angle saturation has always been observed to limit the contact angle modulation, often only down to a contact angle of 60 to 70°.

  4. A Comparison of Cobb Angle: Standing Versus Supine Images of Late-Onset Idiopathic Scoliosis

    Science.gov (United States)

    Vavruch, Ludvig; Tropp, Hans

    2016-01-01

    Summary Background Scoliosis is traditionally evaluated by measuring the Cobb angle in radiograph images taken while the patient is standing. However, low-dose computed tomography (CT) images, which are taken while the patient is in a supine position, provide new opportunities to evaluate scoliosis. Few studies have investigated how the patient’s position, standing or supine, affects measurements. The purpose of this study was to compare the Cobb angle in images from patients while standing versus supine. Material/Methods A total of 128 consecutive patients (97 females and 21 males; mean age 15.5 [11–26] years) with late-onset scoliosis requiring corrective surgery were enrolled. One observer evaluated the type of curve (Lenke classification) and measured the Cobb angle in whole-spine radiography (standing) and scout images from low-dose CT (supine) were taken on the same day. Results For all primary curves, the mean Cobb angle was 59° (SD 12°) while standing and 48° (SD 12°) while in the supine position, with a mean difference of 11° (SD 5°). The correlation between primary standing and supine images had an r value of 0.899 (95% CI 0.860–0.928) and an intra-class correlation coefficient value of 0.969. The correlation between the difference in standing and supine images from primary and secondary curves had an r value of 0.340 (95% CI 0.177–0.484). Conclusions We found a strong correlation between the Cobb angle in images obtained while the patient was standing versus supine for primary and secondary curves. This study is only applicable for patients with severe curves requiring surgical treatment. It enables additional studies based on low-dose CT. PMID:27354881

  5. 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.

  6. 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.

  7. 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...

  8. 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.

  9. Measurements of Neutrino Oscillation Angle theta_13

    CERN Document Server

    Kuze, Masahiro

    2013-01-01

    Neutrinos exhibit an interesting phenomenon called 'neutrino oscillation', in which a neutrino changes its flavor after traveling some flight length. Many experiments measured the mixing angles and mass differences, but the angle $\\theta_{13}$ had been unmeasured due to its smallness compared to others. During 2011 and 2012, series of new-generation neutrino experiments reported positive results in $\\theta_{13}$ search, and its value has been determined to be just below the previous upper limit. The non-zero result of $\\theta_{13}$ is a very good news for future of neutrino physics, since it opens a possibility of measuring the CP violation phase in the lepton sector. An introduction to neutrino oscillation and latest experimental results are presented. A detail is put on Double Chooz reactor experiment, in which the author is involved.

  10. 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.

  11. 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.

  12. 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 ...

  13. Black hole microstates from branes at angle

    CERN Document Server

    Pieri, Lorenzo

    2016-01-01

    We derive the leading g_s perturbation of the SUGRA fields generated by a supersymmetric configuration of respectively 1, 2 or 4 D3-branes intersecting at an arbitrary angle via the computation of the string theory disk scattering amplitude of one massless NSNS field interacting with open strings stretched between the branes. The configuration with four branes is expected to be relevant for black hole microstate counting in four dimensions.

  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. 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.

  16. 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.

  17. Transitions in Secondary Education

    DEFF Research Database (Denmark)

    Larsen, Britt Østergaard; Jensen, Leif; Pilegaard Jensen, Torben

    2014-01-01

    The purpose of this article is to investigate educational choices and attainment of children who experience social problems during their upbringing. The study explores the extent to which social problems can help explain the gaps in entry and dropout rates in upper secondary education in Denmark...... statistical model of educational progression. By using this method, we parcel educational attainment into a series of transitions and the model is able to control for educational selection and unobserved heterogeneity. We apply counterfactual analyses to allow a formal decomposition of the effects of social...... problems. The results show that social problems during upbringing have a large and significant effect on children's educational outcome and that the indicators of social problems explain about 20–30 per cent of the class differences in the students’ educational outcomes....

  18. 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.

  19. 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

  20. Viscoelastic model for redundancy resolution of the human arm via the swivel angle: applications for upper limb exoskeleton control.

    Science.gov (United States)

    Kim, Hyunchul; Roldan, Jay Ryan; Li, Zhi; Rosen, Jacob

    2012-01-01

    One of the key research efforts associated with a redundant seven degree of freedom (7-DOF) upper limb exoskeleton robot that is mechanically coupled to the human body is to develop high and low level control algorithms that enable the system to become a natural extension of the human body. Improving the synergistic relationship between the exoskeleton and the operator is manifested in part by decreasing the force exchange between the two entities. Such a reduction is accomplished in part by developing criteria for resolving the human arm redundancy. The redundancy may be represented by a swivel angle which is defined as the angular rotation of the elbow around an axis that passes through the shoulder and wrist joints. The proposed criteria for defining the swivel angle takes into account the dynamics of the human arm along with a viscoelastic muscle-like model with variable damping. The swivel angle is estimated using the pseudo-inverse of the Jacobian with a secondary objective function that estimates the desired joint angles during human arm movement. The result is then fed to the muscle model to create a more realistic human motion. The estimated swivel angle is then compared with the actual swivel angle measured experimentally by a motion capture system. Results indicate that the average error between the estimated and measured swivel joint angle is 4.4 degrees (in the range [3.7-6] degrees), which are lower than the kinematically based redundant resolution criterion. PMID:23367411

  1. 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.

  2. Pair Creation at Large Inherent Angles

    Energy Technology Data Exchange (ETDEWEB)

    Chen, P.; Tauchi, T.; Schroeder, D.V.; /SLAC

    2007-04-25

    In the next-generation linear colliders, the low-energy e{sup +}e{sup -} pairs created during the collision of high-energy e{sup +}e{sup -} beams would cause potential deleterious background problems to the detectors. At low collider energies, the pairs are made essentially by the incoherent process, where the pair is created by the interaction of beamstrahlung photons on the individual particles in the oncoming beam. This problem was first identified by Zolotarev, et al[1]. At energies where the beamstrahlung parameter {Upsilon} lies approximately in the range 0.6 {approx}< {Upsilon} {approx}< 100, pair creation from the beamstrahlung photons is dominated by a coherent process, first noted by Chen[2]. The seriousness of this pair creation problem lies in the transverse momenta that the pair particles carry when leaving the interaction point (IP) with large angles. One source of transverse momentum is from the kick by the field of the oncoming beam which results in an outcoming angle {theta} {proportional_to} 1/{radical}x, where x is the fractional energy of the particle relative to the initial beam particle energy[2,3]. As was shown in Ref. 131, there in fact exists an energy threshold for the coherent pairs, where x{sub th} {approx}> 1/2{Upsilon}. Thus within a tolerable exiting angle, there exists an upper limit for {Upsilon} where all coherent pairs would leave the detector through the exhaust port[4]. A somewhat different analysis has been done by Schroeder[5]. In the next generation of linear colliders, as it occurs, the coherent pairs can be exponentially suppressed[2] by properly choosing the {Upsilon}({approx}< 0.6). When this is achieved, the incoherent pairs becomes dominant. Since the central issue is the transverse momentum for particles with large angles, we notice that there is another source for it. Namely, when the pair particles are created at low energies, the intrinsic angles of these pairs when produced may already be large. This issue was

  3. 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

  4. 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.

  5. Research on recognition of ramp angle based on transducer

    Directory of Open Access Journals (Sweden)

    Wenhao GU

    2015-12-01

    Full Text Available Focusing on the recognition of ramp angle, the relationship between the signal of vehicle transducer and real ramp angle is studied. The force change of vehicle on the ramp, and the relationship between the body tilt angle and front and rear suspension scale is discussed. According to the suspension and tire deformation, error angle of the ramp angle is deduced. A mathematical model is established with Matlab/Simulink and used for simulation to generate error curve of ramp angle. The results show that the error angle increases with the increasing of the ramp angle, and the limit value can reach 6.5%, while the identification method can effectively eliminate this error, and enhance the accuracy of ramp angle recognition.

  6. 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

  7. 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.

  8. Determining surface wave arrival angle anomalies

    Science.gov (United States)

    Larson, Erik W. F.; Ekström, Göran

    2002-06-01

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

  9. 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.

  10. 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 ...

  11. 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.

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

    Science.gov (United States)

    Tautz, R. C.

    2013-10-01

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

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

    CERN Document Server

    Tautz, R C

    2013-01-01

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

  14. 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

    2015-03-23

    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).

  15. 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

  16. Concomitant occurrence of vestibular schwannoma and epidermoid tumor

    Directory of Open Access Journals (Sweden)

    B V Savitr Sastri

    2013-01-01

    Full Text Available The occurrence of two tumors adjacent to each other at the same site is very rare. We present here, a patient with a vestibular schwannoma found adjacent to an epidermoid tumor in the cerebellopontine angle.

  17. 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...

  18. 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.

  19. 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.

  20. 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...

  1. 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.

  2. Vertical Crossing Angle in IR8

    CERN Document Server

    Holzer , B J; Alemany, R

    2013-01-01

    The operation of the LHCb spectrometer dipole has a considerably larger and more challenging impact on the geometry of the LHC beams than the magnets in the high luminosity regions [1]. The integrated dipole field of 4 Tm deflects the beams in the horizontal plane, and using a set of three dipole magnets, called "compensators" a closed horizontal orbit bump is created. This paper summarizes the basic layout of the beam geometry in IR8 under the influence of the LHCb dipole and its compensators and shows the theoretically expected beam orbits, envelopes and aperture needs in the originally designed version. LHCb operation with both field polarities leads to unequal net crossing angles between the two beams and affects the experiment acceptance. It had been proposed therefore to establish a LHC operation mode where the originally designed horizontal crossing angle is shifted at high energy into the vertical plane leading to a vertical crossing scheme at luminosity operation. The new scheme has been successfully...

  3. 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

  4. 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...

  5. 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.

  6. 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

  7. 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.

  8. 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 ...

  9. Meningioma of the Posterior Skull Base

    Science.gov (United States)

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

    1991-01-01

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

  10. 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

  11. 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

  12. 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

  13. 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.)

  14. Conserved secondary structures in Aspergillus.

    Directory of Open Access Journals (Sweden)

    Abigail Manson McGuire

    Full Text Available BACKGROUND: Recent evidence suggests that the number and variety of functional RNAs (ncRNAs as well as cis-acting RNA elements within mRNAs is much higher than previously thought; thus, the ability to computationally predict and analyze RNAs has taken on new importance. We have computationally studied the secondary structures in an alignment of six Aspergillus genomes. Little is known about the RNAs present in this set of fungi, and this diverse set of genomes has an optimal level of sequence conservation for observing the correlated evolution of base-pairs seen in RNAs. METHODOLOGY/PRINCIPAL FINDINGS: We report the results of a whole-genome search for evolutionarily conserved secondary structures, as well as the results of clustering these predicted secondary structures by structural similarity. We find a total of 7450 predicted secondary structures, including a new predicted approximately 60 bp long hairpin motif found primarily inside introns. We find no evidence for microRNAs. Different types of genomic regions are over-represented in different classes of predicted secondary structures. Exons contain the longest motifs (primarily long, branched hairpins, 5' UTRs primarily contain groupings of short hairpins located near the start codon, and 3' UTRs contain very little secondary structure compared to other regions. There is a large concentration of short hairpins just inside the boundaries of exons. The density of predicted intronic RNAs increases with the length of introns, and the density of predicted secondary structures within mRNA coding regions increases with the number of introns in a gene. CONCLUSIONS/SIGNIFICANCE: There are many conserved, high-confidence RNAs of unknown function in these Aspergillus genomes, as well as interesting spatial distributions of predicted secondary structures. This study increases our knowledge of secondary structure in these aspergillus organisms.

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

    Science.gov (United States)

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

    2014-12-01

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

  16. Computer simulation of dislocation core structure of metastable left angle 111 right angle dislocations in NiAl

    Energy Technology Data Exchange (ETDEWEB)

    Xie, Z.Y. (Dept. of Materials Science and Engineering, Virginia Polytechnic Inst. and State Univ., Blacksburg, VA (United States)); Vailhe, C. (Dept. of Materials Science and Engineering, Virginia Polytechnic Inst. and State Univ., Blacksburg, VA (United States)); Farkas, D. (Dept. of Materials Science and Engineering, Virginia Polytechnic Inst. and State Univ., Blacksburg, VA (United States))

    1993-10-01

    The atomistic structure of dislocation cores of left angle 111 right angle dislocations in NiAl was simulated using embedded atom method potentials and molecular statics computer simulation. In agreement with previous simulation work and experimental observations, the complete left angle 111 right angle dislocation is stable with respect to the two superpartials of 1/2 left angle 111 right angle separated by an antiphase boundary. The structure of the latter configuration, though metastable, is of interest in the search for ways of improving ductility in this material. The structure of the complete dislocation and that of the metastable superpartials was studied using atomistic computer simulation. An improved visualization method was used for the representation of the resulting structures. The structure of the partials is different from that typical of 1/2 left angle 111 right angle dislocations in b.c.c. materials and that reported previously for the B2 structure using model pair potentials. (orig.)

  17. 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

  18. Targets and Secondary Beam Extraction

    Science.gov (United States)

    Noah, Etam

    2014-02-01

    Several applications make use of secondary beams of particles generated by the interaction of a primary beam of particles with a target. Spallation neutrons, bremsstrahlung photon-produced neutrons, radioactive ions and neutrinos are available to users at state-of-the-art facilities worldwide. Plans for even higher secondary beam intensities place severe constraints on the design of targets. This article reports on the main targetry challenges and highlights a variety of solutions for targetry and secondary beam extraction. Issues related to target station layout, instrumentation at the beam-target interface, safety and radioprotection are also discussed.

  19. 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

  20. 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.

  1. 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.

  2. Flow angle from intermediate mass fragment measurements

    Energy Technology Data Exchange (ETDEWEB)

    Rami, F.; Crochet, P.; Dona, R.; De Schauenburg, B.; Wagner, P.; Alard, J.P.; Andronic, A.; Basrak, Z.; Bastid, N.; Belyaev, I.; Bendarag, A.; Berek, G.; Best, D.; Caplar, R.; Devismes, A.; Dupieux, P.; Dzelalija, M.; Eskef, M.; Fodor, Z.; Gobbi, A.; Grishkin, Y.; Herrmann, N.; Hildenbrand, K.D.; Hong, B.; Kecskemeti, J.; Kirejczyk, M.; Korolija, M.; Kotte, R.; Lebedev, A.; Leifels, Y.; Merlitz, H.; Mohren, S.; Moisa, D.; Neubert, W.; Pelte, D.; Petrovici, M.; Pinkenburg, C.; Plettner, C.; Reisdorf, W.; Schuell, D.; Seres, Z.; Sikora, B.; Simion, V.; Siwek-Wilczynska, K.; Stoicea, G.; Stockmeir, M.; Vasiliev, M.; Wisniewski, K.; Wohlfarth, D.; Yushmanov, I.; Zhilin, A

    1999-02-15

    Directed sideward flow of light charged particles and intermediate mass fragments was measured in different symmetric reactions at bombarding energies from 90 to 800 A MeV. The flow parameter is found to increase with the charge of the detected fragment up to Z = 3-4 and then turns into saturation for heavier fragments. Guided by simple simulations of an anisotropic expanding thermal source, we show that the value at saturation can provide a good estimate of the flow angle, {theta}{sub flow}, in the participant region. It is found that {theta}{sub flow} depends strongly on the impact parameter. The excitation function of {theta}{sub flow} reveals striking deviations from the ideal hydrodynamical scaling. The data exhibit a steep rise of {theta}{sub flow} to a maximum at around 250 - 400 A MeV, followed by a moderate decrease as the bombarding energy increases further.

  3. 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.

  4. 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...

  5. 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.

  6. 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.

  7. 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))

  8. Outcomes of trabeculectomy in juvenile open angle glaucoma

    Directory of Open Access Journals (Sweden)

    Daizy Pathania

    2014-01-01

    Full Text Available Purpose: This study was aimed at reporting the outcomes of trabeculectomy in primary juvenile open angle glaucoma (JOAG. Design: This study was a retrospective noncomparative case series. Materials and Methods: We included 60 eyes of 41 JOAG patients who underwent primary trabeculectomy without mitomycin-C (MMC between 1995 and 2007. The primary outcome was success, defined as complete, if intraocular pressure (IOP was >5 and ≤21 mmHg without medications or qualified if IOP was >5 and ≤21 mmHg with or without antiglaucoma medications. Secondary outcome measures were mean and percentage IOP reduction, complications, and risk factors for the failure of trabeculectomy. Results: The mean (±standard deviation age at presentation was 24.1 ± 6.8 years (range, 12-35. Mean follow-up was 67 ± 41 months (range, 12-156. At 1 year, the probability of complete success was 92% (n = 56, 95% CI: 81-96%, at 3 years it was 89% (n = 47, 95% CI: 78-95%, and at the end of 5 years, it was 80% (n = 34, 95% CI: 65-89%. The probability of qualified success was 100% (n = 60 at 1 year, 98% (n = 51, 95% CI: 87-100% at 3 years, and 96% (n = 36, 95% CI: 84-99% at the end of 5 years. The mean IOP reduced from 35 ± 10 to 13 ± 2.5 mmHg (P < 0.001 after trabeculectomy. There was no serious postoperative complication. Young age was the only significant risk factor associated with the failure (odds ratio = 0.89, P = 0.03. Conclusion: Primary trabeculectomy without MMC has good success rates in JOAG.

  9. 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.

  10. 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.

  11. 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....

  12. 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...

  13. 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...

  14. 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.

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

    Science.gov (United States)

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

    2014-06-01

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

  16. 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

  17. The correlation of multi-angle thermal infrared data and the choice of optimal view angles

    Institute of Scientific and Technical Information of China (English)

    FAN; Wenjie; XU; Xiru

    2004-01-01

    Based on the matrix formula of thermal infrared radiant system, the components temperature can be retrieved by the inversive matrix. Around the stability problem of retrieved result, the research work we did was focused on (i) the correlation of (wk,j) which is the key to affect the retrieval accuracy, (ii) a general method which can help us find the number of retrievable parameters and evaluate the retrieval error before its performance, (iii) the choice of "optimal viewing angle group" based on the formula of absolute error propagation. The row winter wheat field was chosen as an example. The results can provide a theoretical basis for multi-angle thermal infrared remote sensing and components temperature retrieval.

  18. 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.

  19. 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.

  20. 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...

  1. 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.

  2. 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.

  3. 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.

  4. Study on flow behavior and structure over chined fuselage at high angle of attack

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    A study of leeward vortex structure over chined fuselage and the effects of micro tip perturbation on its vortex flow have been carried out in wind tunnel experiments at Reynolds numbers from 1.26×105 to 5.04×105 with PIV and pressure measurement techniques.Firstly,the experiment results have proved that micro tip perturbation has no effects on the vortex flow and its aerodynamic characteristics over chined fuselage at high angle of attack,in which there are not any non-deterministic flow behaviors.Secondly,the evolution of leeward vortex structure over chined fuselage along the axis of model can be divided into four flow regimes:linear conical developed regime,decay regime of leeward vortex intensity,asymmetric leeward vortex break down regime and completely break down regime.And a correlation between leeward vortex structure and sectional aerodynamic force was also revealed in the present paper.Thirdly,the experiment results show the behavior of leeward vortex core trajectories and zonal characteristics of leeward vortex structure with angles of attack.Finally,the experiment results of Reynolds number effect on the leeward vortex flow have further confirmed research conclusions from previous studies:the flows over chined fuselage at high angles of attack are insensitive to variation of Reynolds number,and there is a little effect on the secondary boundary layer separation and the suction peak induced by leeward vortex.

  5. Luminosity Anti-leveling with Crossing Angle (MD 1669)

    CERN Document Server

    Gorzawski, Arkadiusz; Ponce, Laurette; Salvachua Ferrando, Belen Maria; Wenninger, Jorg; CERN. Geneva. ATS Department

    2016-01-01

    A significant fraction of the LHC luminosity ($\\sim$30\\% in 2016) is lost due to the presence (and necessity) of the crossing angles at the IPs. At the LHC the crossing angle is typically set to a value that provides sufficient separation of the beams at the start of fills for the peak bunch intensities. As the bunch intensity decays during a fill, it is possible to reduce the crossing angle and recover some luminosity. A smooth crossing angle reduction procedure must be developed to take advantage of this option during stable beam operation. During this MD a smooth procedure for luminosity leveling with crossing angle was tested. It was demonstrated that the orbit was well controlled, beam losses were low and the offset leveled experiments ALICE and LHCb were not affected by crossing angle leveling in ATLAS and CMS.

  6. Design Estimation of Aerodynamic Angles of High Speed Cars

    Directory of Open Access Journals (Sweden)

    Debojyoti Mitra

    2010-05-01

    Full Text Available The study of aerodynamic design of high-speed cars is mainly based on the wind-tunnel experiments and computational methods till date. In this particular study three car models of 100,200,300 pitch angles and 500,600,700 yaw angles are employed, and by wind-tunnel experiments we obtain pressure distributions over them. Now the correlations between drag-coefficient, lift-coefficient, pitch-angle and yaw-angle with Reynolds number are obtained by regression analysis of experimental data using MATLAB software. After plotting graphs it can be concluded that for minimum aerodynamic drag the optimized value of pitch and yaw angle should be 300 and 500. This type of study is expected to give a fair idea of aerodynamic angle design of high-speed cars.

  7. 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.

  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. Perturbative estimates of lepton mixing angles in unified models

    Energy Technology Data Exchange (ETDEWEB)

    Antusch, Stefan [Max-Planck-Institut fuer Physik (Werner-Heisenberg-Institut), Foehringer Ring 6, 80805 Muenchen (Germany)], E-mail: antusch@mppmu.mpg.de; King, Stephen F. [School of Physics and Astronomy, University of Southampton, Southampton, SO17 1BJ (United Kingdom); Malinsky, Michal [Department of Theoretical Physics, School of Engineering Sciences, Royal Institute of Technology (KTH) - AlbaNova University Center, Roslagstullsbacken 21, SE-106 91 Stockholm (Sweden)

    2009-10-11

    Many unified models predict two large neutrino mixing angles, with the charged lepton mixing angles being small and quark-like, and the neutrino masses being hierarchical. Assuming this, we present simple approximate analytic formulae giving the lepton mixing angles in terms of the underlying high energy neutrino mixing angles together with small perturbations due to both charged lepton corrections and renormalisation group (RG) effects, including also the effects of third family canonical normalization (CN). We apply the perturbative formulae to the ubiquitous case of tri-bimaximal neutrino mixing at the unification scale, in order to predict the theoretical corrections to mixing angle predictions and sum rule relations, and give a general discussion of all limiting cases. We also discuss the implications for the sum rule relations of the measurement of a non-zero reactor angle, as hinted at by recent experimental measurements.

  10. Transition radiation produced in dihedral and trihedral angles

    Energy Technology Data Exchange (ETDEWEB)

    Serov, A.V. [P.N. Lebedev Physical Institute, RAS, 119991 Moscow (Russian Federation)], E-mail: servo@x4u.lebedev.ru; Bolotovskii, B.M. [P.N. Lebedev Physical Institute, RAS, 119991 Moscow (Russian Federation)

    2008-09-15

    Method of electrical images is applied to the description of transition radiation generated when a charges particle passes through a dihedral angle formed by perfectly conducting planes. It is shown that the electromagnetic field generated when a charged particle passes through a dihedral angle {alpha} = {pi}/m is equivalent to the field generated by 2m charged particles which instantaneously start to move. Transition radiation in trihedral angle is also considered.

  11. 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

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

    Science.gov (United States)

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

    1995-01-01

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

  13. 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...

  14. 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...

  15. Mechanism and Etiology of Primary Chronic Angle Closure Glaucoma

    Institute of Scientific and Technical Information of China (English)

    1994-01-01

    The ocular anatomic features, pupil-blocking force, status of angle synechiae closure and positivity of provocative tests were compared between the primary chronic angle closure glaucoma (PCACG) and primary a-cute angle closure glaucoma (PAACG) by using ultrasonic biometry, computerized anterior ocular segment image processing technique, gonioscopy and provocative tests. The studies showed that the anterior chamber depth of PAACG was shallower than that of PCACG; the pupil-blocking force of PAACG was st...

  16. 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

  17. Chapman Solar Zenith Angle variations at Titan

    Science.gov (United States)

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

    2016-10-01

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

  18. 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....

  19. [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.

  20. [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

  1. 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.

  2. 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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2006-01-12

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

  4. 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 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., whether the solitons fuse or cross. We find an analytical expression determining the inwards escape angle using...... Gaussian approximations for the solitons. The theory is verified numerically....

  5. Light Scattering of Rough Orthogonal Anisotropic Surfaces with Secondary Most Probable Slope Distributions

    Institute of Scientific and Technical Information of China (English)

    LI Hai-Xia; CHENG Chuan-Fu

    2011-01-01

    @@ We study the light scattering of an orthogonal anisotropic rough surface with secondary most probable slope distribution It is found that the scattered intensity profiles have obvious secondary maxima, and in the direction perpendicular to the plane of incidence, the secondary maxima are oriented in a curve on the observation plane,which is called the orientation curve.By numerical calculation of the scattering wave fields with the height data of the sample, it is validated that the secondary maxima are induced by the side face element, which constitutes the prismoid structure of the anisotropic surface.We derive the equation of the quadratic orientation curve.Experimentally, we construct the system for light scattering measurement using a CCD.The scattered intensity profiles are extracted from the images at different angles of incidence along the orientation curves.The experimental results conform to the theory.

  6. 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)

  7. 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...

  8. 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...

  9. Simulation of Canopy Leaf Inclination Angle in Rice

    Institute of Scientific and Technical Information of China (English)

    ZHANG Xiao-cui; LU Chuan-gen; HU Ning; YAO Ke-min; ZHANG Qi-jun; DAI Qi-gen

    2013-01-01

    A leaf inclination angle distribution model, which is applicable to simulate leaf inclination angle distribution in six heights of layered canopy at different growth stages, was established by component factors affecting plant type in rice. The accuracy of the simulation results was validated by measured values from a field experiment. The coefficient of determination (R2) and the root mean square error (RMSE) between the simulated and measured values were 0.9472 and 3.93%, respectively. The simulation results showed that the distribution of leaf inclination angles differed among the three plant types. The leaf inclination angles were larger in the compact variety Liangyoupeijiu with erect leaves than in the loose variety Shanyou 63 with droopy leaves and the intermediate variety Liangyou Y06. The leaf inclination angles were distributed in the lower range in Shanyou 63, which matched up with field measurements. The distribution of leaf inclination angles in the same variety changed throughout the seven growth stages. The leaf inclination angles enlarged gradually from transplanting to booting. During the post-booting period, the leaf inclination angle increased in Shanyou 63 and Liangyou Y06, but changed little in Liangyoupeijiu. At every growth stage of each variety, canopy leaf inclination angle distribution on the six heights of canopy layers was variable. As canopy height increased, the layered leaf area index (LAI) decreased in all the three plant types. However, while the leaf inclination angles showed little change in Liangyoupeijiu, they became larger in Shanyou 63 but smaller in Liangyou Y06. The simulation results used in the constructed model were very similar to the actual measurement values. The model provides a method for estimating canopy leaf inclination angle distribution in rice production.

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

    Science.gov (United States)

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

    2016-01-01

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

  11. Secondary School Design: Physical Education.

    Science.gov (United States)

    Department of Education and Science, London (England).

    Current trends in physical education in secondary schools in England are analysed in relation to the design of indoor physical education facilities. Spaces needed for the study of movement in dance and modern gymnastics are outlined; and the indoor provisions necessary for games, athletics, contests, and swimming are discussed, with comments on…

  12. 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…

  13. 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

  14. Defining secondary progressive multiple sclerosis.

    Science.gov (United States)

    Lorscheider, Johannes; Buzzard, Katherine; Jokubaitis, Vilija; Spelman, Tim; Havrdova, Eva; Horakova, Dana; Trojano, Maria; Izquierdo, Guillermo; Girard, Marc; Duquette, Pierre; Prat, Alexandre; Lugaresi, Alessandra; Grand'Maison, François; Grammond, Pierre; Hupperts, Raymond; Alroughani, Raed; Sola, Patrizia; Boz, Cavit; Pucci, Eugenio; Lechner-Scott, Jeanette; Bergamaschi, Roberto; Oreja-Guevara, Celia; Iuliano, Gerardo; Van Pesch, Vincent; Granella, Franco; Ramo-Tello, Cristina; Spitaleri, Daniele; Petersen, Thor; Slee, Mark; Verheul, Freek; Ampapa, Radek; Amato, Maria Pia; McCombe, Pamela; Vucic, Steve; Sánchez Menoyo, José Luis; Cristiano, Edgardo; Barnett, Michael H; Hodgkinson, Suzanne; Olascoaga, Javier; Saladino, Maria Laura; Gray, Orla; Shaw, Cameron; Moore, Fraser; Butzkueven, Helmut; Kalincik, Tomas

    2016-09-01

    A number of studies have been conducted with the onset of secondary progressive multiple sclerosis as an inclusion criterion or an outcome of interest. However, a standardized objective definition of secondary progressive multiple sclerosis has been lacking. The aim of this work was to evaluate the accuracy and feasibility of an objective definition for secondary progressive multiple sclerosis, to enable comparability of future research studies. Using MSBase, a large, prospectively acquired, global cohort study, we analysed the accuracy of 576 data-derived onset definitions for secondary progressive multiple sclerosis and first compared these to a consensus opinion of three neurologists. All definitions were then evaluated against 5-year disease outcomes post-assignment of secondary progressive multiple sclerosis: sustained disability, subsequent sustained progression, positive disability trajectory, and accumulation of severe disability. The five best performing definitions were further investigated for their timeliness and overall disability burden. A total of 17 356 patients were analysed. The best definition included a 3-strata progression magnitude in the absence of a relapse, confirmed after 3 months within the leading Functional System and required an Expanded Disability Status Scale step ≥4 and pyramidal score ≥2. It reached an accuracy of 87% compared to the consensus diagnosis. Seventy-eight per cent of the identified patients showed a positive disability trajectory and 70% reached significant disability after 5 years. The time until half of all patients were diagnosed was 32.6 years (95% confidence interval 32-33.6) after disease onset compared with the physicians' diagnosis at 36 (35-39) years. The identified patients experienced a greater disease burden [median annualized area under the disability-time curve 4.7 (quartiles 3.6, 6.0)] versus non-progressive patients [1.8 (1.2, 1.9)]. This objective definition of secondary progressive multiple

  15. 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. 

  16. Angle dependence of Andreev scattering at semiconductor-superconductor interfaces

    DEFF Research Database (Denmark)

    Mortensen, Asger; Flensberg, Karsten; Jauho, Antti-Pekka

    1999-01-01

    and increase of the probability of normal reflection. We show that in the presence of a Fermi velocity mismatch between the semiconductor and the superconductor the angles of incidence and transmission are related according to the well-known Snell's law in optics. As a consequence there is a critical angle...

  17. 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 ...

  18. 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

  19. 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

  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. 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

  3. Showers with large zenith angles observed in emulsion chambers

    Institute of Scientific and Technical Information of China (English)

    任敬儒; 陆穗苓; 解卫; 王承瑞; 何瑁; 张乃健

    1997-01-01

    Showers with large zenith angles are observed in emulsion chambers exposed at Mt.Kanbala.The intensity of high energy muons is given and the multicore showers with large zenith angles are found.It is indicated that a new phenomenon may exist in the high energy nuclear interactions of cosmic rays.

  4. Engineering sidewall angles of silica-on-silicon waveguides

    DEFF Research Database (Denmark)

    Haiyan, Ou

    2004-01-01

    Burned photoresist is used as etch mask when producing silica-onsilicon waveguides. The sidewall angle of the optical glass waveguides is engineered by varying photoresist thickness and etch selectivity. The principle for the formation of the angles is introduced and very promising experimental...

  5. 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

  6. Dynamic aspects of contact angle measurements on adsorbed protein layers

    NARCIS (Netherlands)

    Scheer, van der At; Smolders, Cees A.

    1978-01-01

    Contact angle measurements using drops of paraffin oil have been performed on polystyrene (PS) substrates, coated with human serum albumin (HSA) or human fibrinogen (HFb), immersed in buffer solution. The contact angle appeared to be time dependent. The final value for HSA-coated substrates was 50°

  7. 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.

  8. 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...

  9. 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.

  10. 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

  11. 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.

  12. Setup for Fission and Evaporation Cross-Section Measurements in Reactions Induced by Secondary Beams

    CERN Document Server

    Hassan, A A; Kalpakchieva, R; Skobelev, N K; Penionzhkevich, Yu E; Dlouhý, Z; Radnev, S; Poroshin, N V

    2002-01-01

    A setup for studying reactions induced by secondary radioactive beams has been constructed. It allows simultaneous measurement of alpha-particle and fission fragment energy spectra. By measuring the alpha-particles, identification of evaporation residues is achieved. A set of three targets can be used so as to ensure sufficient statistics. Two silicon detectors, located at 90 degrees to the secondary beam direction, face each target, thus covering 30 % of the solid angle. This experimental setup is to be used to obtain excitation functions of fusion?fission reactions and of reactions leading to evaporation residue production.

  13. 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...

  14. 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'.

  15. Poincare duality angles for Riemannian manifolds with boundary

    CERN Document Server

    Shonkwiler, Clayton

    2009-01-01

    On a compact Riemannian manifold with boundary, the absolute and relative cohomology groups appear as certain subspaces of harmonic forms. DeTurck and Gluck showed that these concrete realizations of the cohomology groups decompose into orthogonal subspaces corresponding to cohomology coming from the interior and boundary of the manifold. The principal angles between these interior subspaces are all acute and are called Poincare duality angles. This paper determines the Poincare duality angles of a collection of interesting manifolds with boundary derived from complex projective spaces and from Grassmannians, providing evidence that the Poincare duality angles measure, in some sense, how "close" a manifold is to being closed. This paper also elucidates a connection between the Poincare duality angles and the Dirichlet-to-Neumann operator for differential forms, which generalizes the classical Dirichlet-to-Neumann map arising in the problem of Electrical Impedance Tomography. Specifically, the Poincare duality...

  16. 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.

  17. 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.

  18. [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

  19. Spectral data of specular reflectance, narrow-angle transmittance and angle-resolved surface scattering of materials for solar concentrators

    Directory of Open Access Journals (Sweden)

    Philipp Good

    2016-03-01

    Full Text Available The spectral specular reflectance of conventional and novel reflective materials for solar concentrators is measured with an acceptance angle of 17.5 mrad over the wavelength range 300−2500 nm at incidence angles 15–60° using a spectroscopic goniometry system. The same experimental setup is used to determine the spectral narrow-angle transmittance of semi-transparent materials for solar collector covers at incidence angles 0–60°. In addition, the angle-resolved surface scattering of reflective materials is recorded by an area-scan CCD detector over the spectral range 350–1050 nm. A comprehensive summary, discussion, and interpretation of the results are included in the associated research article “Spectral reflectance, transmittance, and angular scattering of materials for solar concentrators” in Solar Energy Materials and Solar Cells.

  20. Spectral data of specular reflectance, narrow-angle transmittance and angle-resolved surface scattering of materials for solar concentrators.

    Science.gov (United States)

    Good, Philipp; Cooper, Thomas; Querci, Marco; Wiik, Nicolay; Ambrosetti, Gianluca; Steinfeld, Aldo

    2016-03-01

    The spectral specular reflectance of conventional and novel reflective materials for solar concentrators is measured with an acceptance angle of 17.5 mrad over the wavelength range 300-2500 nm at incidence angles 15-60° using a spectroscopic goniometry system. The same experimental setup is used to determine the spectral narrow-angle transmittance of semi-transparent materials for solar collector covers at incidence angles 0-60°. In addition, the angle-resolved surface scattering of reflective materials is recorded by an area-scan CCD detector over the spectral range 350-1050 nm. A comprehensive summary, discussion, and interpretation of the results are included in the associated research article "Spectral reflectance, transmittance, and angular scattering of materials for solar concentrators" in Solar Energy Materials and Solar Cells.

  1. 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.

  2. 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.

  3. 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.

  4. Primary and secondary care integration.

    Science.gov (United States)

    McCormick, I R; Boyd, M A

    1994-10-26

    Integration of primary and secondary health care is a goal of the 1993 New Zealand health reforms. Focus groups were selected to raise options and stimulate improved integration between primary and secondary care in the Auckland metropolitan and rural areas. Cooperation, communication, coordination, were considered relevant. Several detailed recommendations were produced. They fell into six groups; (1) liaison committees or meetings, (2) communication, (3) referral admission discharge, (4) joint ventures, (5) horizontal integration and (6) general. A key recommendation was that regional health authorities should fund liaison committees or functions to promote inter provider integration. The findings of the focus groups are placed in context of the wider requirements for integration. These are integrated funding, integrated information systems, integrated purchasing and utilisation management.

  5. 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.

  6. 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.

  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. 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.

  9. 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.

  10. 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...

  11. 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.

  12. 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.

  13. 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)

  14. 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...

  15. Determination of basic friction angle using various laboratory tests.

    Science.gov (United States)

    Jang, Bo-An

    2016-04-01

    The basic friction angle of rock is an important factor of joint shear strength and is included within most shear strength criteria. It can be measured by direct shear test, triaxial compression test and tilt test. Tilt test is mostly used because it is the simplest method. However, basic friction angles measured using tilt test for same rock type or for one sample are widely distributed and often do not show normal distribution. In this research, the basic friction angles for the Hangdeung granite form Korea and Berea sandstone from USA are measured accurately using direct shear test and triaxial compression test. Then basic friction angles are again measured using tilt tests with various conditions and are compared with those measured using direct shear test and triaxial compression test to determine the optimum condition of tilt test. Three types of sliding planes, such as planes cut by saw and planes polished by #100 and #600 grinding powders, are prepared. When planes are polished by #100 grinding powder, the basic friction angles measured using direct shear test and triaxial compression test are very consistent and show narrow ranges. However, basic friction angles show wide ranges when planes are cut by saw and are polished by #600 grinding powder. The basic friction angle measured using tilt test are very close to those measured using direct shear test and triaxial compression test when plane is polished by #100 grinding powder. When planes are cut by saw and are polished by #600 grinding powder, basic friction angles measured using tilt test are slightly different. This indicates that tilt test with plane polished by #100 grinding powder can yield an accurate basic friction angle. In addition, the accurate values are obtained not only when planes are polished again after 10 times of tilt test, but values are averaged by more 30 times of tests.

  16. 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.

  17. 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.)

  18. Evaluation of the nasolabial angle in the Indian population

    Directory of Open Access Journals (Sweden)

    Vinay Dua

    2010-01-01

    Full Text Available Nasolabial angle has become the angle depicting the esthetics so has attained the prime importance in the treatment planning. Dr Jay P. Fitzgerland and Dr. Ram S. Nanda. In 1992 gave norms for Caucasian population. A radiographic cephalometric study was undertaken with 45 subjects of Indian origin to evaluate and compare with their result. The method of evaluation was according to the criteria given by Dr. Jay P Fitzergerald in AJODO 1992; 102:328-34. Significant decrease in nasolabial angle values was found in case of Indian population as compared to white adults.

  19. Remote logo detection using angle-distance histograms

    Science.gov (United States)

    Youn, Sungwook; Ok, Jiheon; Baek, Sangwook; Woo, Seongyoun; Lee, Chulhee

    2016-05-01

    Among all the various computer vision applications, automatic logo recognition has drawn great interest from industry as well as various academic institutions. In this paper, we propose an angle-distance map, which we used to develop a robust logo detection algorithm. The proposed angle-distance histogram is invariant against scale and rotation. The proposed method first used shape information and color characteristics to find the candidate regions and then applied the angle-distance histogram. Experiments show that the proposed method detected logos of various sizes and orientations.

  20. 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.

  1. 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...

  2. 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.

  3. 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.

  4. 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.

  5. 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...

  6. 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.)

  7. 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)

  8. 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

  9. Cross-Sections of Large-Angle Hadron Production in Proton- and Pion-Nucleus Interactions V: Lead Nuclei and Beam Momenta from +/-3 Gev/c to +/-15 Gev/c

    CERN Document Server

    Bolshakova, A; Chelkov, G; Dedovitch, D; Elagin, A; Gostkin, M; Guskov, A; Kroumchtein, Z; Nefedov, Yu; Nikolaev, K; Zhemchugov, A; Dydak, F; Wotschack, J; De Min, A; Ammosov, A; Gapienko, V; Koreshev, V; Semak, A; Sviridov, Yu; Usenko, E; Zaets, V

    2010-01-01

    We report on double-differential inclusive cross-sections of the production of secondary protons, charged pions, and deuterons, in the interactions with a 5% nuclear interaction length thick stationary lead target, of proton and pion beams with momentum from +/-3 GeV/c to +/-15 GeV/c. Results are given for secondary particles with production angles 20 to 125 degrees. Cross-sections on lead nuclei are compared with cross-sections on beryllium, copper, and tantalum nuclei.

  10. Secondary effects of glyphosate on plants

    Science.gov (United States)

    Glyphosate is a unique herbicide with interesting secondary effects. Unfortunately, some have assumed that the secondary effects that occur in glyphosate-susceptible plants treated with glyphosate, such as altered mineral nutrition, reduced phenolic compound production and pathogen resistance, also ...

  11. 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

  12. 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...

  13. 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...

  14. 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

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. 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

  1. Generalized parton distributions and wide-angle exclusive scattering

    CERN Document Server

    Kroll, P

    2004-01-01

    The handbag mechanism for wide-angle exlusive scattering reactions is discussed and compared with other theoretical approaches. Its application to Compton scattering, meson photoproduction and two-photon annihilations into pairs of hadrons is reviewed.

  2. Folded cavity angled-grating broad-area lasers.

    Science.gov (United States)

    Zhao, Yunsong; Zhu, Lin

    2013-10-01

    The angled-grating broad-area laser is a promising candidate for high power, high brightness diode laser source. The key point in the design is the angled gratings which can simultaneously support the unique snake-like zigzag lasing mode and eliminate the direct Fabry-Perot (FP) feedback. Unlike a conventional laser waveguide mode, the phase front of the zigzag mode periodically changes along the propagation direction. By use of the mirror symmetry of the zigzag mode, we propose and demonstrate the folded cavity angled-grating broad-area lasers. One benefit of this design is to reduce the required wafer space compared to a regular angled-grating broad-area laser, especially in a long cavity laser for high power operation. Experimental results show that the folded cavity laser exhibits good beam quality in far field with a slightly larger threshold and smaller slope efficiency due to the additional interface loss.

  3. 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.

  4. Uncertainty Relation between Angular Momentum and Angle Variable.

    Science.gov (United States)

    Roy, C. L.; Sannigrahi, A. B.

    1979-01-01

    Discusses certain pitfalls regarding the uncertainty relation between angular momentum and the angle variable from a pedagogic point of view. Further, an uncertainty relation has been derived for these variables in a simple and consistant manner. (Author/HM)

  5. 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)...

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. Flow tilt angles near forest edges - Part 1: Sonic anemometry

    DEFF Research Database (Denmark)

    Dellwik, Ebba; Mann, Jakob; Larsen, Klaus Steenberg

    2010-01-01

    An analysis of flow tilt angles from a fetch-limited beech forest site with clearings is presented in the context of vertical advection of carbon dioxide. Flow angles and vertical velocities from two sonic anemometers by different manufacturers were analyzed. Instead of using rotations, where zero......-flow angles were assumed for neutral flow, the data was interpreted in relation to upstream and downstream forest edges. Uncertainties caused by flow distortion, vertical misalignment and limited sampling time (statistical uncertainty) were evaluated and found to be highly significant. Since the attack angle...... distribution of the wind on the sonic anemometer is a function of atmospheric stratification, an instrumental error caused by imperfect flow distortion correction is also a function of the atmospheric stratification. In addition, it is discussed that the sonic anemometers have temperature dependent off...

  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. "Angle" Operator Conjugate to Photon's Intrinsic Angular Momentum

    Institute of Scientific and Technical Information of China (English)

    范洪义

    2001-01-01

    We find the correct "angle" operator conjugate to the intrinsic angular momentum of the photon by introducing a suitable representation which involves both left-handed and right-handed polarization photon operators.

  14. 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...

  15. 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…

  16. 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....

  17. 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...

  18. 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...

  19. 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.

  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. Pitch angle scattering of energetic particles by oblique whistler waves

    Science.gov (United States)

    Inan, U. S.; Bell, T. F.

    1991-01-01

    First order cyclotron or Landau resonant pitch angle scattering of electrons by oblique whistler waves propagating at large angles to the ambient field are found to be at least as large as that due to parallel propagating waves. Commonly observed precipitation of more than 40 keV electrons in association with ducted whistlers may thus be accompanied by substantial fluxes of lower energy (10 eV-40 keV) electrons precipitated by the nonducted components.

  2. Landweber Iterative Methods for Angle-limited Image Reconstruction

    Institute of Scientific and Technical Information of China (English)

    Gang-rong Qu; Ming Jiang

    2009-01-01

    We introduce a general itcrative scheme for angle-limited image reconstruction based on Landwe-ber's method. We derive a representation formula for this scheme and consequently establish its convergence conditions. Our results suggest certain relaxation strategies for an accelerated convergcnce for angle-limited im-age reconstruction in L2-norm comparing with alternative projection methods. The convolution-backprojection algorithm is given for this iterative process.

  3. Projections, Birkhoff Orthogonality and Angles in Normed Spaces

    Institute of Scientific and Technical Information of China (English)

    CHEN ZHI-ZHI; LIN WEI; Luo Lü-LIN; Ji You-qing

    2011-01-01

    Let X be a Minkowski plane,i.e.,a real two dimensional normed linear space.We use projections to give a definition of the angle Aq(x,y) between two vectors x and y in X,such that x is Birkhoff orthogonal to y if and only if Aq(x,y) =π/2.Some other properties of this angle are also discussed.

  4. Making action-angle disc models for Gaia

    CERN Document Server

    McMillan, Paul J

    2015-01-01

    A brief review of recent work. I describe dynamical modelling of the Milky Way using action-angle coordinates. I explain what action-angle coordinates are, and what progress has been made in the past few years to ensuring they can be used in reasonably realistic Galactic potentials. I then describe recent modelling efforts, and progress they have made in constraining the potential of the Milky Way and the local dark matter density.

  5. 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...

  6. 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.

  7. 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....

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

    Science.gov (United States)

    Freitas, Sandro R; Vaz, João R; Bruno, Paula M; Valamatos, Maria J; Mil-Homens, Pedro

    2013-11-01

    Previous studies have used isokinetic dynamometry to assess joint torques and angles during passive extension of the knee, often without reporting upon methodological errors and reliability outcomes. In addition, the reliability of the techniques used to measure passive knee extension torque-angle and the extent to which reliability may be affected by the position of the subjects is also unclear. Therefore, we conducted an analysis of the intra- and inter-session reliability of two methods of assessing passive knee extension: (A) a 2D kinematic analysis coupled to a custom-made device that enabled the direct measurement of resistance to stretch and (B) an isokinetic dynamometer used in two testing positions (with the non-tested thigh either flexed at 45° or in the neutral position). The intra-class correlation coefficients (ICCs) of torque, the slope of the torque-angle curve, and the parameters of the mathematical model that were fit to the torque-angle data for the above conditions were measured in sixteen healthy male subjects (age: 21.4 ± 2.1 yr; BMI: 22.6 ± 3.3 kg m(-2); tibial length: 37.4 ± 3.4 cm). The results found were: (1) methods A and B led to distinctly different torque-angle responses; (2) passive torque-angle relationship and stretch tolerance were influenced by the position of the non-tested thigh; and (3) ICCs obtained for torque were higher than for the slope and for the mathematical parameters that were fit to the torque-angle curve. In conclusion, the measurement method that is used and the positioning of subjects can influence the passive knee extension torque-angle outcome.

  9. 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...

  10. 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.

  11. 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...

  12. 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].

  13. 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

  14. 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

  15. 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.

  16. 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.

  17. Determination of the Contact Angle Based on the Casimir Effect

    Science.gov (United States)

    Mazuruk, K.; Volz, M. P.

    2015-01-01

    In several crystal growth processed based on capillarity, a melt comes into contact with a crucible wall at an angle defined as the contact angle. For molten metals and semiconductors, this contact angle is dependent upon both the crucible and melt material and typical values fall in the range 80-170deg. However, on a microscopic scale, there does not exist a precise and sharp contact angle but rather the melt and solid surfaces merge smoothly and continuously over a distance of up to several micrometers. Accurate modeling requires a more advanced treatment of this interaction. The interaction between the melt and solid surfaces can be calculated by considering two forces: a short-range repulsive force and a longer range (up to a few micrometers) Casimir force. The Casimir force between the two bodies of complex geometry is calculated using a retarded temperature Green's function (Matsubara type) for the photon in the medium. The governing equations are cast in the form of a set of boundary integral equations which are then solved numerically for the case of molten Ge on SiO2. The shape of the molten surface approaching the flat solid body is determined, and the contact angle is defined as the angle between the two surfaces at the microscopically asymptotic distance of 1-2 micrometers. The formulation of this model and the results of the numerical calculations will be presented and discussed.

  18. Orientation angle rotatability of planar serial n-link manipulators

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    This paper presents a new method of analyzing the orientation angle rotatability of a planar serial n-link manipulator by examining the rotatability of its virtual equivalent mechanism.Workspace orientation boundary region decomposition is proposed based on the polynomial discriminant derived from a serial three-link manipulator.Orientation angle workspace indicates a set of angle ranges by which the end-effector can reach with certain orientation for every point in the reachable position workspace.By introducing a virtual equivalent mechanism,the open-chain kinematic problem is converted into a close-chain mechanism,and the Grashof-type condition is used to examine the rotatability of the end-effector link.The reachable position workspace can be divided into several Grashof intervals and non-Grashof intervals based on the extreme positions and singular configurations of a manipulator.The derived equations in this paper can be used to calculate the variation rule of the orientation angle workspace of any given planar serial n-link manipulator on the basis of its link parameters.The orientation angle rotatability of a seven-link serial manipulator is solved by the proposed method and graphical representations of the orientation angle workspaces are mapped onto a three-dimensional coordinate system.The theoretical approach has practical significance for the design of a highly dexterous serial n-link manipulator with proposed link relations.

  19. 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.

  20. Predicting bed form roughness: the influence of lee side angle

    Science.gov (United States)

    Lefebvre, Alice; Winter, Christian

    2016-04-01

    Flow transverse bedforms (ripples and dunes) are ubiquitous in rivers and coastal seas. Local hydrodynamics and transport conditions depend on the size and geometry of these bedforms, as they constitute roughness elements at the bed. Bedform influence on flow energy must be considered for the understanding of flow dynamics, and in the development and application of numerical models. Common estimations or predictors of form roughness (friction factors) are based mostly on data of steep bedforms (with angle-of-repose lee slopes), and described by highly simplified bedform dimensions (heights and lengths). However, natural bedforms often are not steep, and differ in form and hydraulic effect relative to idealised bedforms. Based on systematic numerical model experiments, this study shows how the hydraulic effect of bedforms depends on the flow structure behind bedforms, which is determined by the bedform lee side angle, aspect ratio and relative height. Simulations reveal that flow separation behind bedform crests and, thus, a hydraulic effect is induced at lee side angles steeper than 11 to 18° depending on relative height, and that a fully developed flow separation zone exists only over bedforms with a lee side angle steeper than 24°. Furthermore, the hydraulic effect of bedforms with varying lee side angle is evaluated and a reduction function to common friction factors is proposed. A function is also developed for the Nikuradse roughness (k s), and a new equation is proposed which directly relates k s to bedform relative height, aspect ratio and lee side angle.

  1. Guidance law with impact time and impact angle constraints

    Institute of Scientific and Technical Information of China (English)

    Zhang Youan; Ma Guoxin; Liu Aili

    2013-01-01

    A novel closed-form guidance law with impact time and impact angle constraints is proposed for salvo attack of anti-ship missiles,which employs missile's normal acceleration (not jerk) as the control command directly.Firstly,the impact time control problem is formulated as tracking the designated time-to-go (the difference between the designated impact time and the current flight time) for the actual time-to-go of missile,and the impact angle control problem is formulated as tracking the designated heading angle for the actual heading angle of missile.Secondly,a biased proportional navigation guidance (BPNG) law with designated heading angle constraint is constructed,and the actual time-to-go estimation for this BPNG is derived analytically by solving the system differential equations.Thirdly,by adding a feedback control to this constructed BPNG to eliminate the time-to-go error-the difference between the standard time-to-go and the actual time-to-go,a guidance law with adjustable coefficients to control the impact time and impact angle simultaneously is developed.Finally,simulation results demonstrate the performance and feasibility of the proposed approach.

  2. 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.

  3. OCULAR BIOMETRY IN ANGLE CLOSURE GLAUCOMA AND SENILE CATARACT

    Institute of Scientific and Technical Information of China (English)

    WANG Yu-lan; SHENG Yao-hua; YE Xiang-yu

    2008-01-01

    Objective To compare ocular biometric values in angle closure glaucoma and cataract in senile population.Methods Ocular biometry was performed in eyes classified to have angle closure glaucoma (29 eyes) and senile cataract (31 eyes). Ocular biometry readings between two groups were compared and analyzed statistically. Intraocular pressure was also recorded before and after lens extraction.Results Anterior chamber depth was shallower in patients with angle closure glaucoma group [(1.79±0.56) mm] compared with senile cataract group [(2.69±0.40) mm] (P<0.01). Lens thickness was greater in angle closure glaucoma group [(5.30±0.61) mm] than that in senile cataract group [(3.84±0.61) mm] (P<0.01). Phacoemusification was performed in 5 patients with persistent acute attack of angle closure glaucoma. IOPs were controlled in all five cases after lens extraction.Conclusion Eyes with angle closure glaucoma seems to have significantly shallow anterior chamber and greater lens thickness compared to senile cataract eyes in the same age. Lens extraction might be effective in those cases with such anatomy features.

  4. 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 ...

  5. 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.

  6. 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.

  7. 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...

  8. 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...

  9. 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......://www.secondarymetabolites.org) is introduced to provide a one-stop catalog and links to these bioinformatics resources. In addition, an outlook is presented how the existing tools and those to be developed will influence synthetic biology approaches in the natural products field....

  10. 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.

  11. Demarcation of secondary hyperalgesia zones

    DEFF Research Database (Denmark)

    Ringsted, Thomas K; Enghuus, Casper; Petersen, Morten A;

    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 two......, demarcated by polyamide monofilaments (bending force: 0.2, 69 and 2569mN) and a "weighted-pin" stimulator (512mN), were assessed 45 to 75min after each BI. RESULTS: A random effect, linear mixed model demonstrated a logarithmic correlation between elicited skin pressures (mN/mm(2)) and the SHAs (P

  12. Individualized Mathematics Instruction: How Effective Has It Been in Secondary and Post Secondary Schools?

    Science.gov (United States)

    Schoen, Harold L.

    A review of studies comparing self-paced individualized programs with other teaching approaches at the secondary and post secondary level is presented in this paper. First, the teaching approaches used and the statistical design employed in the studies are described. Then, the studies are classified as secondary or post secondary, and the results…

  13. 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)

  14. 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.

  15. Secondary production in shallow marine environments

    Energy Technology Data Exchange (ETDEWEB)

    Pomeroy, L.R. (ed.)

    1976-01-01

    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. (HLW)

  16. 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/.

  17. 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

  18. Tribology in secondary wood machining

    Energy Technology Data Exchange (ETDEWEB)

    Ko, P.L.; Hawthorne, H.M.; Andiappan, J.

    1998-07-01

    Secondary wood manufacturing covers a wide range of products from furniture, cabinets, doors and windows, to musical instruments. Many of these are now mass produced in sophisticated, high speed numerical controlled machines. The performance and the reliability of the tools are key to an efficient and economical manufacturing process as well as to the quality of the finished products. A program concerned with three aspects of tribology of wood machining, namely, tool wear, tool-wood friction characteristics and wood surface quality characterization, was set up in the Integrated Manufacturing Technologies Institute (IMTI) of the National Research Council of Canada. The studies include friction and wear mechanism identification and modeling, wear performance of surface-engineered tool materials, friction-induced vibration and cutting efficiency, and the influence of wear and friction on finished products. This research program underlines the importance of tribology in secondary wood manufacturing and at the same time adds new challenges to tribology research since wood is a complex, heterogeneous, material and its behavior during machining is highly sensitive to the surrounding environments and to the moisture content in the work piece.

  19. Reliability of the ATD Angle in Dermatoglyphic Analysis.

    Science.gov (United States)

    Brunson, Emily K; Hohnan, Darryl J; Giovas, Christina M

    2015-09-01

    The "ATD" angle is a dermatoglyphic trait formed by drawing lines between the triradii below the first and last digits and the most proximal triradius on the hypothenar region of the palm. This trait has been widely used in dermatoglyphic studies, but several researchers have questioned its utility, specifically whether or not it can be measured reliably. The purpose of this research was to examine the measurement reliability of this trait. Finger and palm prints were taken using the carbon paper and tape method from the right and left hands of 100 individuals. Each "ATD" angle was read twice, at different times, by Reader A, using a goniometer and a magnifying glass, and three times by a Reader B, using Adobe Photoshop. Inter-class correlation coefficients were estimated for the intra- and inter-reader measurements of the "ATD" angles. Reader A was able to quantify ATD angles on 149 out of 200 prints (74.5%), and Reader B on 179 out of 200 prints (89.5%). Both readers agreed on whether an angle existed on a print 89.8% of the time for the right hand and 78.0% for the left. Intra-reader correlations were 0.97 or greater for both readers. Inter-reader correlations for "ATD" angles measured by both readers ranged from 0.92 to 0.96. These results suggest that the "ATD" angle can be measured reliably, and further imply that measurement using a software program may provide an advantage over other methods.

  20. 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.

  1. 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.

  2. Estimation of crank angle for cycling with a powered prosthesis.

    Science.gov (United States)

    Lawson, B E; Shultz, A; Ledoux, E; Goldfarb, M

    2014-01-01

    In order for a prosthesis to restore power generation during cycling, it must supply torque in a manner that is coordinated with the motion of the bicycle crank. This paper outlines an algorithm for the real time estimation of the angular position of a bicycle crankshaft using only measurements internal to an intelligent knee and ankle prosthesis. The algorithm assumes that the rider/prosthesis/bicycle system can be modeled as a four-bar mechanism. Assuming that a prosthesis can generate two independent angular measurements of the mechanism (in this case the knee angle and the absolute orientation of the shank), Freudenstein's equation can be used to synthesize the mechanism continuously. A recursive least-squares algorithm is implemented to estimate the Freudenstein coefficients, and the resulting link lengths are used to reformulate the equation in terms of input-output relationships mapping both measured angles to the crank angle. Using two independent measurements allows the algorithm to uniquely determine the crank angle from multi-valued functions. In order to validate the algorithm, a bicycle was mounted on a trainer and configured with the prosthesis using an artificial hip joint attached to the seat post. Motion capture was used to monitor the mechanism for forward and backward pedaling and the results are compared to the output of the presented algorithm. Once the parameters have converged, the algorithm is shown to predict the crank angle within 15° of the externally measured value throughout the entire crank cycle during forward rotation.

  3. 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.

  4. 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...

  5. 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

  6. 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)

  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. 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

  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. 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.

  11. 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.

  12. 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.

  13. 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)

  14. 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.

  15. 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)

  16. 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.

  17. Corner detection using arc length-based angle estimator

    Science.gov (United States)

    Zhang, Shizheng; Yang, Dan; Huang, Sheng; Zhang, Xiaohong; Qu, Ying; Tu, Liyun; Ren, Zemin

    2015-11-01

    We present a corner-detection method named arc length-based angle estimator (AAE). Different from most of the existing approaches, AAE focuses on employing angle detection for finding corners, because angle is an important measure for discrete curvature. AAE provides a new robust solution to the estimation of the K-cosine. In AAE, the K-cosine estimation issue in the x, y space is considered as the problem of the slope estimations in the s, x and s, y spaces, where s is the arc length. Then, weighted least square fitting is employed to address such a slope estimation issue. Experimental results demonstrate that AAE can achieve promising performance in comparison with some recent state-of-the-art approaches under two commonly used evaluation metrics, namely average repeatability and localization error criteria.

  18. Water contact angles and hysteresis of polyamide surfaces.

    Science.gov (United States)

    Extrand, C W

    2002-04-01

    The wetting behavior of a series of aliphatic polyamides (PAs) has been examined. PAs with varying amide content and polyethylene (PE) were molded against glass to produce surfaces with similar roughness. After cleaning, chemical composition of the surfaces was verified with X-ray photoelectron spectroscopy. Advancing and receding contact angles were measured from small sessile water drops. Contact angles decreased with amide content while hysteresis increased. Hysteresis arose primarily from molecular interactions between the contact liquid and the solid substrates, rather than moisture absorption, variations in crystallinity, surface deformation, roughness, reorientation of amide groups, or surface contamination. Free energies of hysteresis were calculated from contact angles. For PE, which is composed entirely of nonpolar methylene groups, free energies were equivalent to the strength of dispersive van der Waals bonds. For PAs, free energies corresponded to fractional contributions from the dispersive methylene groups and polar amide groups.

  19. Neutrino Mixing Angles in Sequential Dominance to NLO and NNLO

    CERN Document Server

    Antusch, S; King, S F

    2010-01-01

    Neutrinos with hierarchical masses and two large mixing angles may naturally originate from sequential dominance (SD). Within this framework we present analytic expressions for the neutrino mixing angles including the next-to-leading order (NLO) and next-to-next-to-leading order (NNLO) corrections arising from the second lightest and lightest neutrino masses. The analytic results for neutrino mixing angles in SD presented here, including the NLO and NNLO corrections, are applicable to a wide class of models and may provide useful insights when confronting the models with data from high precision neutrino experiments. We also point out that for special cases of SD corresponding to form dominance (FD) the NLO and NNLO corrections both vanish. For example we study tri-bimaximal (TB) mixing via constrained sequential dominance (CSD) which involves only a NNLO correction and tri-bimaximal-reactor (TBR) mixing via partially constrained sequential dominance (PCSD) which involves a NLO correction suppressed by the sm...

  20. Determination of the mixing angle between new charmonium states

    Energy Technology Data Exchange (ETDEWEB)

    Aliev, T.M. [Middle East Technical University, Physics Department, Ankara (Turkey); Institute of Physics, Baku (Azerbaijan); Savci, M. [Middle East Technical University, Physics Department, Ankara (Turkey)

    2015-04-01

    Using the pictures for X(3872) as a mixture of charmonium and molecular D{sup *0}D{sup 0} states; Y(3940) as a mixture of χ{sub c0} and D{sup *}D{sup '*} states, and Y(4260) as a mixture of the tetra-quark state with charmonium states, the corresponding mixing angles are estimated within the QCD sum rules. We find that our predictions for the mixing angles of the X(3872), Y(4260), and Y(3940) states are considerably smaller compared to work in which the mixing angles are estimated from the condition in reproducing the mass of these states. Our conclusion is that the considered pictures for the X(3872), Y(4260), and Y(3940) states are not successful in describing these states. (orig.)

  1. Determination of the mixing angle between new charmonium states

    Energy Technology Data Exchange (ETDEWEB)

    Aliev, T. M., E-mail: taliev@metu.edu.tr [Physics Department, Middle East Technical University, 06800, Ankara (Turkey); Institute of Physics, Baku (Azerbaijan); Savcı, M., E-mail: savci@metu.edu.tr [Physics Department, Middle East Technical University, 06800, Ankara (Turkey)

    2015-04-28

    Using the pictures for X(3872) as a mixture of charmonium and molecular D{sup ∗0}D{sup 0} states; Y(3940) as a mixture of χ{sub c0} and D{sup ∗}D{sup ′∗} states, and Y(4260) as a mixture of the tetra-quark state with charmonium states, the corresponding mixing angles are estimated within the QCD sum rules. We find that our predictions for the mixing angles of the X(3872), Y(4260), and Y(3940) states are considerably smaller compared to work in which the mixing angles are estimated from the condition in reproducing the mass of these states. Our conclusion is that the considered pictures for the X(3872), Y(4260), and Y(3940) states are not successful in describing these states.

  2. Determining pitch-angle diffusion coefficients from test particle simulations

    CERN Document Server

    Ivascenko, A; Spanier, F; Vainio, R

    2016-01-01

    Transport and acceleration of charged particles in turbulent media is a topic of great interest in space physics and interstellar astrophysics. These processes are dominated by the scattering of particles off magnetic irregularities. The scattering process itself is usually described by small-angle scattering with the pitch-angle coefficient $D_{\\mu\\mu}$ playing a major role. Since the diffusion coefficient $D_{\\mu\\mu}$ can be determined analytically only for the approximation of quasi-linear theory, the determination of this coefficient from numerical simulations has, therefore, become more important. So far these simulations yield particle tracks for small-scale scattering, which can then be interpreted using the running diffusion coefficients. This method has a limited range of validity. This paper presents two new methods that allow for the calculation of the pitch-angle diffusion coefficient from numerical simulations. These methods no longer analyse particle trajectories, but the change of particle dist...

  3. Evolution of the Jet Opening Angle Distribution in Holographic Plasma.

    Science.gov (United States)

    Rajagopal, Krishna; Sadofyev, Andrey V; van der Schee, Wilke

    2016-05-27

    We use holography to analyze the evolution of an ensemble of jets, with an initial probability distribution for their energy and opening angle as 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 and (ii) because wide-angle jets lose more energy, energy loss combined with the steeply falling perturbative spectrum serves to filter wide jets out of the ensemble at any given energy. Even though every jet widens, jets with a given energy can have a smaller mean opening angle after passage through the plasma than jets with that energy would have had in vacuum, as experimental data may indicate. PMID:27284647

  4. Experimental investigation of synthetic aperture flow angle estimation

    DEFF Research Database (Denmark)

    Oddershede, Niels; Jensen, Jørgen Arendt

    2005-01-01

    Currently synthetic aperture flow methods can find the correct velocity magnitude, when the flow direction is known. To make a fully automatic system, the direction should also be estimated. Such an approach has been suggested by Jensen (2004) based on a search of the highest cross-correlation as......Currently synthetic aperture flow methods can find the correct velocity magnitude, when the flow direction is known. To make a fully automatic system, the direction should also be estimated. Such an approach has been suggested by Jensen (2004) based on a search of the highest cross......-correlation as a function of velocity and angle. This paper presents an experimental investigation of this velocity angle estimation method based on a set of synthetic aperture flow data measured using our RASMUS experimental ultrasound system. The measurements are performed for flow angles of 60, 75, and 90 deg...

  5. Optimization of sharp and viewing-angle-independent structural color

    CERN Document Server

    Hsu, Chia Wei; Johnson, Steven G; Soljačić, Marin

    2014-01-01

    Structural coloration produces some of the most brilliant colors in nature and has many applications. However, sharp color (narrow frequency response) and wide viewing angle (broad angular response) are competing properties and have not been achieved simultaneously in previous studies. Here, we use numerical optimization to discover geometries where the structural color is sharp, yet the hue, saturation, and brightness all remain the same over broad viewing angles (0-90$^\\circ$) under directional illumination. Our model system consists of dipole scatterers arranged into several rings; interference among the scattered waves is optimized to yield the wavelength-selective and angle-insensitive response. Such designs can be useful for display, painting, and biosensing applications.

  6. Generalised action-angle coordinates defined on island chains

    CERN Document Server

    Dewar, Robert L; Gibson, Ashley M

    2012-01-01

    Straight-field-line coordinates are very useful for representing magnetic fields in toroidally confined plasmas, but fundamental problems arise regarding their definition in 3-D geometries because of the formation of islands and chaotic field regions, ie non-integrability. In Hamiltonian dynamical systems terms these coordinates are a form of action-angle variables, which are normally defined only for integrable systems. In order to describe 3-D magnetic field systems, a generalisation of this concept was proposed recently by the present authors that unified the concepts of ghost surfaces and quadratic-flux-minimising (QFMin) surfaces. This was based on a simple canonical transformation generated by a change of variable $\\theta = \\theta(\\Theta,\\zeta)$, where $\\theta$ and $\\zeta$ are poloidal and toroidal angles, respectively, with $\\Theta$ a new poloidal angle chosen to give pseudo-orbits that are a) straight when plotted in the $\\zeta,\\Theta$ plane and b) QFMin pseudo-orbits in the transformed coordinate. Th...

  7. Determination of the mixing angle between new charmonium states

    International Nuclear Information System (INIS)

    Using the pictures for X(3872) as a mixture of charmonium and molecular D∗0D0 states; Y(3940) as a mixture of χc0 and D∗D′∗ states, and Y(4260) as a mixture of the tetra-quark state with charmonium states, the corresponding mixing angles are estimated within the QCD sum rules. We find that our predictions for the mixing angles of the X(3872), Y(4260), and Y(3940) states are considerably smaller compared to work in which the mixing angles are estimated from the condition in reproducing the mass of these states. Our conclusion is that the considered pictures for the X(3872), Y(4260), and Y(3940) states are not successful in describing these states

  8. Determination of the mixing angle between new charmonium states

    International Nuclear Information System (INIS)

    Using the pictures for X(3872) as a mixture of charmonium and molecular D*0D0 states; Y(3940) as a mixture of χc0 and D*D'* states, and Y(4260) as a mixture of the tetra-quark state with charmonium states, the corresponding mixing angles are estimated within the QCD sum rules. We find that our predictions for the mixing angles of the X(3872), Y(4260), and Y(3940) states are considerably smaller compared to work in which the mixing angles are estimated from the condition in reproducing the mass of these states. Our conclusion is that the considered pictures for the X(3872), Y(4260), and Y(3940) states are not successful in describing these states. (orig.)

  9. Interstellar Refractive Scintillation and Intraday Polarization Angle Swings

    Institute of Scientific and Technical Information of China (English)

    Shan-Jie Qian; Xi-Zhen Zhang; A. Kraus

    2005-01-01

    Intraday polarization angle swings of ~180° observed in two sources (QSO 0917+624 and QSO 1150+812) are discussed in the framework of refractive interstellar scintillation by a continuous interstellar medium. Model-fits to the I-,Q- and U- light curves were made for both sources. It is shown that for the case of 0917+624 both the intraday intensity variations and the polarization angle swing of ~180° could be explained consistently in terms of a four-component model, which comprises one steady and two scintillating polarized components and one further non-polarized scintillating component. The polarization angle swing of ~180° observed in 1150+812, which occurred when the polarized flux density was almost constant, could not be explained in terms of refractive scintillation by a continuous medium and might be due to other mechanisms (e.g., scintillation by interstellar clouds).

  10. Pitch Angle Control for Variable Speed Wind Turbines

    DEFF Research Database (Denmark)

    Chen, Zhe; Zhang, Jianzhong; Cheng, M;

    2008-01-01

    Pitch angle control is the most common means for adjusting the aerodynamic torque of the wind turbine when wind speed is above rated speed and various controlling variables may be chosen, such as wind speed, generator speed and generator power. As conventional pitch control usually use PI...... controller, the mathematical model of the system should be known well. A fuzzy logic pitch angle controller is developed in this paper, in which it does not need well known about the system and the mean wind speed is used to compensate the non-linear sensitivity. The fuzzy logic control strategy may have...... the potential when the system contains strong non-linearity, such as wind turbulence is strong, or the control objectives include fatigue loads. The design of the fuzzy logic controller and the comparisons with conversional pitch angle control strategies with various controlling variables are carried out...

  11. Automated measurement of diagnostic angles for hip dysplasia

    DEFF Research Database (Denmark)

    de Raedt, Sepp; Mechlenburg, Inger Buur; Stilling, Maiken;

    2013-01-01

    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....... 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...... 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...

  12. Analysis of a Low-Angle Annular Expander Nozzle

    Directory of Open Access Journals (Sweden)

    Kyll Schomberg

    2015-01-01

    Full Text Available An experimental and numerical analysis of a low-angle annular expander nozzle is presented to observe the variance in shock structure within the flow field. A RANS-based axisymmetric numerical model was used to evaluate flow characteristics and the model validated using experimental pressure readings and schlieren images. Results were compared with an equivalent converging-diverging nozzle to determine the capability of the wake region in varying the effective area of a low-angle design. Comparison of schlieren images confirmed that shock closure occurred in the expander nozzle, prohibiting the wake region from affecting the area ratio. The findings show that a low angle of deflection is inherently unable to influence the effective area of an annular supersonic nozzle design.

  13. Communicability Angle and the Spatial Efficiency of Networks

    CERN Document Server

    Estrada, Ernesto

    2014-01-01

    We introduce the concept of communicability angle between a pair of nodes in a graph. We provide strong analytical and empirical evidence that the average communicability angle for a given network accounts for its spatial efficiency on the basis of the communications among the nodes in a network. We determine characteristics of the spatial efficiency of more than a hundred real-world complex networks that represent complex systems arising in a diverse set of scenarios. In particular, we find that the communicability angle correlates very well with the experimentally measured the relative packing efficiency of proteins that are represented as residue networks. We finally show how we can modulate the spatial efficiency of a network by tuning the weights of the edges of the networks. This allows us to predict effects of external stresses on the spatial efficiency of a network as well as to design strategies to improve important parameters in real-world complex systems.

  14. Oscillations of Relative Inclination Angles in Compact Extrasolar Planetary Systems

    CERN Document Server

    Becker, Juliette C

    2015-01-01

    The Kepler Mission has detected dozens of compact planetary systems with more than four transiting planets. This sample provides a collection of close-packed planetary systems with relatively little spread in the inclination angles of the inferred orbits. A large fraction of the observational sample contains limited multiplicity, begging the question whether there is a true diversity of multi transiting systems, or if some systems merely possess high mutual inclinations, allowing them to appear as single-transiting systems in a transit-based survey. This paper begins an exploration of the effectiveness of dynamical mechanisms in exciting orbital inclination within exoplanetary systems of this class. For these tightly packed systems, we determine that the orbital inclination angles are not spread out appreciably through self-excitation. In contrast, the two Kepler multi-planet systems with additional non-transiting planets are susceptible to oscillations of their inclination angles, which means their currently...

  15. Flow tilt angles near forest edges - Part 2: Lidar anemometry

    DEFF Research Database (Denmark)

    Dellwik, Ebba; Mann, Jakob; Bingöl, Ferhat

    2010-01-01

    from a conically scanning lidar. In this mode of measurement, the lidar beam is rotated in a circle by a prism with a fixed angle to the vertical at varying focus distances. By fitting a trigonometric function to the scans, the mean vertical velocity can be estimated. Lidar measurements from (1......) a fetch-limited beech forest site taken at 48–175 m a.g.l. (above ground level), (2) a reference site in flat agricultural terrain and (3) a second reference site in complex terrain are presented. The method to derive flow tilt angles and mean vertical velocities from lidar has several advantages compared....... The estimated mean vertical velocity is biased if the flow over the scanned circle is not homogeneous. It is demonstrated that the error on the mean vertical velocity due to flow inhomogeneity can be approximated by a function of the angle of the lidar beam to the vertical and the vertical gradient of the mean...

  16. Contact Angles and Surface Tension of Germanium-Silicon Melts

    Science.gov (United States)

    Croell, A.; Kaiser, N.; Cobb, S.; Szofran, F. R.; Volz, M.; Rose, M. Franklin (Technical Monitor)

    2001-01-01

    Precise knowledge of material parameters is more and more important for improving crystal growth processes. Two important parameters are the contact (wetting) angle and the surface tension, determining meniscus shapes and surface-tension driven flows in a variety of methods (Czochralski, EFG, floating-zone, detached Bridgman growth). The sessile drop technique allows the measurement of both parameters simultaneously and has been used to measure the contact angles and the surface tension of Ge(1-x)Si(x) (0 less than or equal to x less than or equal to 1.3) alloys on various substrate materials. Fused quartz, Sapphire, glassy carbon, graphite, SiC, carbon-based aerogel, pyrolytic boron nitride (pBN), AIN, Si3N4, and polycrystalline CVD diamond were used as substrate materials. In addition, the effect of different cleaning procedures and surface treatments on the wetting behavior were investigated. Measurements were performed both under dynamic vacuum and gas atmospheres (argon or forming gas), with temperatures up to 1100 C. In some experiments, the sample was processed for longer times, up to a week, to investigate any changes of the contact angle and/or surface tension due to slow reactions with the substrate. For pure Ge, stable contact angles were found for carbon-based substrates and for pBN, for Ge(1-x)Si(x) only for pBN. The highest wetting angles were found for pBN substrates with angles around 170deg. For the surface tension of Ge, the most reliable values resulted in gamma(T) = (591- 0.077 (T-T(sub m)) 10(exp -3)N/m. The temperature dependence of the surface tension showed similar values for Ge(1-x)Si(x), around -0.08 x 10(exp -3)N/m K, and a compositional dependence of 2.2 x 10(exp -3)N/m at%Si.

  17. Small angle elastic scattering of electrons by noble gas atoms

    International Nuclear Information System (INIS)

    In this thesis, measurements are carried out to obtain small angle elastic differential cross sections in order to check the validity of Kramers-Kronig dispersion relations for electrons scattered by noble gas atoms. First, total cross sections are obtained for argon, krypton and xenon. Next, a parallel plate electrostatic energy analyser for the simultaneous measurement of doubly differential cross section for small angle electron scattering is described. Also absolute differential cross sections are reported. Finally the forward dispersion relation for electron-helium collisions is dealt with. (Auth.)

  18. 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.

    (1993) 173-181 173 Elsevier Science Publishers B.V., Amsterdam 00036-1 Technical note The wave vane a device to measure the breaker angle P. Chandramohan, B.U. Nayak and N.M. Anand National Institute of Oceanography, Goa 403 004, India (Received... of a wave direction recording instrument, a simple device called the wave vane as described here has been developed to measure the breaking wave angle. The changes in the horizontal component of the orbital velocity under a progressive wave govern...

  19. Metamaterials with angle selective emissivity in the near-infrared.

    Science.gov (United States)

    Bossard, Jeremy A; Werner, Douglas H

    2013-03-11

    Metamaterials have been previously studied for their ability to tailor the dispersive IR emissivity of a surface. Here, we investigate two metamaterial structures based on an electromagnetic band-gap surface and a dielectric resonator array for use as near-IR emitters with custom angle selectivity. A genetic algorithm is successfully employed to optimize the metamaterial structures to have minimum emissivity in the normal direction and high emissivity at custom off-normal angles specified by the designer. Two symmetry conditions are utilized to achieve emissivity patterns that are azimuthally stable or distinct in the two orthogonal plane cuts.

  20. Broadband wide-angle polarization converter for LCD backlight.

    Science.gov (United States)

    Tsai, Chang-Ching; Wu, Shin-Tson

    2008-05-20

    A novel polarization converter using reflective metallic gratings and a polarization beam splitter is introduced for LCD backlight illumination. These two optical elements form a polarization rotation resonator. Broadband and high optical efficiency of polarization conversion in the visible region is achieved through the resonance of the refracted light and the surface plasmon wave in metallic surface-relief gratings. For wide-angle illumination, the conversion efficiency with arbitrary incident angle is studied. This device can convert unpolarized light to linear polarization with over 85% efficiency. PMID:18493296

  1. Automatic learning-based beam angle selection for thoracic IMRT

    International Nuclear Information System (INIS)

    Purpose: The treatment of thoracic cancer using external beam radiation requires an optimal selection of the radiation beam directions to ensure effective coverage of the target volume and to avoid unnecessary treatment of normal healthy tissues. Intensity modulated radiation therapy (IMRT) planning is a lengthy process, which requires the planner to iterate between choosing beam angles, specifying dose–volume objectives and executing IMRT optimization. In thorax treatment planning, where there are no class solutions for beam placement, beam angle selection is performed manually, based on the planner’s clinical experience. The purpose of this work is to propose and study a computationally efficient framework that utilizes machine learning to automatically select treatment beam angles. Such a framework may be helpful for reducing the overall planning workload. Methods: The authors introduce an automated beam selection method, based on learning the relationships between beam angles and anatomical features. Using a large set of clinically approved IMRT plans, a random forest regression algorithm is trained to map a multitude of anatomical features into an individual beam score. An optimization scheme is then built to select and adjust the beam angles, considering the learned interbeam dependencies. The validity and quality of the automatically selected beams evaluated using the manually selected beams from the corresponding clinical plans as the ground truth. Results: The analysis included 149 clinically approved thoracic IMRT plans. For a randomly selected test subset of 27 plans, IMRT plans were generated using automatically selected beams and compared to the clinical plans. The comparison of the predicted and the clinical beam angles demonstrated a good average correspondence between the two (angular distance 16.8° ± 10°, correlation 0.75 ± 0.2). The dose distributions of the semiautomatic and clinical plans were equivalent in terms of primary target volume

  2. Measurement of the CKM angle $\\gamma$ at LHCb

    CERN Multimedia

    Gersabeck, M

    2009-01-01

    The precise measurement of the CKM unitarity triangle angle $\\gamma$ is a key goal of the LHCb physics programme. The uncertainty on $\\gamma$, the currently least-well known of the three angles, will be reduced dramatically. Complementary measurements will be made in tree-level processes, and modes where loop diagrams play an important role. The tree-level measurements will cover time-integrated as well as time- dependent measurements in both the $B^0_d$ and the $B^0_s$ sectors. The ensemble of these measurements will provide a powerful test of whether new physics phases contribute to heavy-flavour transitions.

  3. Analysis and design of wide-angle foveated optical systems

    Science.gov (United States)

    Curatu, George

    2009-12-01

    The development of compact imaging systems capable of transmitting high-resolution images in real-time while covering a wide field-of-view (FOV) is critical in a variety of military and civilian applications: surveillance, threat detection, target acquisition, tracking, remote operation of unmanned vehicles, etc. Recently, optical foveated imaging using liquid crystal (LC) spatial light modulators (SLM) has received considerable attention as a potential approach to reducing size and complexity in fast wide-angle lenses. The fundamental concept behind optical foveated imaging is reducing the number of elements in a fast wide-angle lens by placing a phase SLM at the pupil stop to dynamically compensate aberrations left uncorrected by the optical design. In the recent years, considerable research and development has been conducted in the field of optical foveated imaging based on the LC SLM technology, and several foveated optical systems (FOS) prototypes have been built. However, most research has been focused so far on the experimental demonstration of the basic concept using off-the-shelf components, without much concern for the practicality or the optical performance of the systems. Published results quantify only the aberration correction capabilities of the FOS, often claiming diffraction-limited performance at the region of interest (ROI). However, these results have continually overlooked diffraction effects on the zero-order efficiency and the image quality. The research work presented in this dissertation covers the methods and results of a detailed theoretical research study on the diffraction analysis, image quality, design, and optimization of fast wide-angle FOSs based on the current transmissive LC SLM technology. The amplitude and phase diffraction effects caused by the pixelated aperture of the SLM are explained and quantified, revealing fundamental limitations imposed by the current transmissive LC SLM technology. As a part of this study, five

  4. Angle of Arrival Detection with Fifth Order Phase Operators

    CERN Document Server

    Khmou, Youssef

    2015-01-01

    In this paper, a fifth order propagator operators are proposed for estimating the Angles Of Arrival (AOA) of narrowband electromagnetic waves impinging on antenna array when its number of sensors is larger than the number of radiating sources. The array response matrix is partitioned into five linearly dependent phases to construct the noise projector using five different propagators from non diagonal blocks of the spectral matrice of the received data; hence, five different estimators are proposed to estimate the angles of the sources. The simulation results proved the performance of the proposed estimators in the presence of white noise comparatively to high resolution eigen based spectra.

  5. Investigation of Brazed Plate Heat Exchangers With Variable Chevron Angles

    Directory of Open Access Journals (Sweden)

    S. Muthuraman

    2013-08-01

    Full Text Available - Experiments to measure the condensation heat transfer coefficient and the pressure drop in brazed plate heat exchangers (BPHEs were performed with the refrigerants R410A and R22. Brazed plate heat exchangers with different chevron angles of 45°, 35°, and 20° were used. Varying the mass flux, the condensation temperature, and the vapor quality of the refrigerant, we measured the condensation heat transfer coefficient and the pressure drops. Both the heat transfer coefficient and the pressure drop increased proportionally with the mass flux and the vapor quality and inversely with the condensation temperature and the chevron angle.

  6. Precise predictions of neutrino mixing angles and $CP$ phase

    CERN Document Server

    Abbas, Gauhar

    2016-01-01

    The neutrino mixing parameters are studied using renormalization-group evolution of Dirac neutrinos with recently proposed parameterization of the neutrino mixing angles referred as `high-scale mixing relations'. The correlations among all neutrino mixing and $CP$ violating parameters are investigated. The predictions for the neutrino mixing angles and the $CP$ phase are precise and could be easily tested by ongoing and future experiments. We observe that the high scale mixing unification hypothesis is incompatible with Dirac neutrinos due to updated experimental data.

  7. X-ray diffraction at Bragg angles around π/2

    International Nuclear Information System (INIS)

    X-ray diffraction at Bragg angles around π/2 is studied from the theoretical and experimental points of view. The proposed corrections to the dynamical theory in the θβ ≅ π/2 cases, has been reviewed showing the equivalence between two formalisms leading to a corrected expression for the dependence of the angular parameter y with the angle of incidence. An expression for y valid in the conventional and θ β ≅ π/2 cases has been obtained. A general expression for Bragg law and for energy resolution after a Bragg diffraction was also deduced. (author)

  8. RELATIONSHIP BETWEEN THE SIZE OF PONTOCEREBELLAR ANGLE TUMOR AND AUDIOLOGY

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Objective: To study the relationship between the size ofpontocerebellar angle tumor and audiology.Methods: Retrospective analysis of accoustically evoked brainstem response (ABR) waveforms and pure tone threshold in 27 subjects with tumor of pontocerebellar angle.Results: ABR wave forms and pure tone threshold were significantly affected statistically by the size of tumors,especially those tumor larger than 3 cm in diameter.Conclusion: The primary symptom of the patient was unilateral hearing loss.Early discovery of the lesion is important and ABR is a sensitive tool for early diagnose of the tumor.

  9. Automatic learning-based beam angle selection for thoracic IMRT

    Energy Technology Data Exchange (ETDEWEB)

    Amit, Guy; Marshall, Andrea [Radiation Medicine Program, Princess Margaret Cancer Centre, Toronto, Ontario M5G 2M9 (Canada); Purdie, Thomas G., E-mail: tom.purdie@rmp.uhn.ca; Jaffray, David A. [Radiation Medicine Program, Princess Margaret Cancer Centre, Toronto, Ontario M5G 2M9 (Canada); Department of Radiation Oncology, University of Toronto, Toronto, Ontario M5S 3E2 (Canada); Techna Institute, University Health Network, Toronto, Ontario M5G 1P5 (Canada); Levinshtein, Alex [Department of Computer Science, University of Toronto, Toronto, Ontario M5S 3G4 (Canada); Hope, Andrew J.; Lindsay, Patricia [Radiation Medicine Program, Princess Margaret Cancer Centre, Toronto, Ontario M5G 2M9, Canada and Department of Radiation Oncology, University of Toronto, Toronto, Ontario M5S 3E2 (Canada); Pekar, Vladimir [Philips Healthcare, Markham, Ontario L6C 2S3 (Canada)

    2015-04-15

    Purpose: The treatment of thoracic cancer using external beam radiation requires an optimal selection of the radiation beam directions to ensure effective coverage of the target volume and to avoid unnecessary treatment of normal healthy tissues. Intensity modulated radiation therapy (IMRT) planning is a lengthy process, which requires the planner to iterate between choosing beam angles, specifying dose–volume objectives and executing IMRT optimization. In thorax treatment planning, where there are no class solutions for beam placement, beam angle selection is performed manually, based on the planner’s clinical experience. The purpose of this work is to propose and study a computationally efficient framework that utilizes machine learning to automatically select treatment beam angles. Such a framework may be helpful for reducing the overall planning workload. Methods: The authors introduce an automated beam selection method, based on learning the relationships between beam angles and anatomical features. Using a large set of clinically approved IMRT plans, a random forest regression algorithm is trained to map a multitude of anatomical features into an individual beam score. An optimization scheme is then built to select and adjust the beam angles, considering the learned interbeam dependencies. The validity and quality of the automatically selected beams evaluated using the manually selected beams from the corresponding clinical plans as the ground truth. Results: The analysis included 149 clinically approved thoracic IMRT plans. For a randomly selected test subset of 27 plans, IMRT plans were generated using automatically selected beams and compared to the clinical plans. The comparison of the predicted and the clinical beam angles demonstrated a good average correspondence between the two (angular distance 16.8° ± 10°, correlation 0.75 ± 0.2). The dose distributions of the semiautomatic and clinical plans were equivalent in terms of primary target volume

  10. Fractal dimension and unscreened angles measured for radial viscous fingering.

    Science.gov (United States)

    Praud, Olivier; Swinney, Harry L

    2005-07-01

    We have examined fractal patterns formed by the injection of air into oil in a thin (0.127 mm) layer contained between two cylindrical glass plates of 288 mm diameter (a Hele-Shaw cell), for pressure differences in the range 0.25 DLA) clusters. We have also measured the probability distribution of unscreened angles. At late times, the distribution approaches a universal (i.e., forcing and size-independent) asymptotic form that has mean 145 degrees Celsius and standard deviation 36 degrees Celsius. These results indicate that the distribution function for the unscreened angle is an invariant property of the growth process. PMID:16089960

  11. Off-Angle Iris Correction using a Biological Model

    Energy Technology Data Exchange (ETDEWEB)

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

    2013-01-01

    This work implements an eye model to simulate corneal refraction effects. Using this model, ray tracing is performed to calculate transforms to remove refractive effects in off-angle iris images when reprojected to a frontal view. The correction process is used as a preprocessing step for off-angle iris images for input to a commercial matcher. With this method, a match score distribution mean improvement of 11.65% for 30 degree images, 44.94% for 40 degree images, and 146.1% improvement for 50 degree images is observed versus match score distributions with unmodi ed images.

  12. Off-Angle Iris Correction using a Biological Model

    Energy Technology Data Exchange (ETDEWEB)

    Santos-Villalobos, Hector J [ORNL; Karakaya, Mahmut [ORNL; Barstow, Del R [ORNL; Boehnen, Chris Bensing [ORNL

    2013-01-01

    This work implements an eye model to simulate corneal refraction effects. Using this model, ray tracing is performed to calculate transforms to remove refractive effects in off-angle iris images when reprojected to a frontal view. The correction process is used as a preprocessing step for off-angle iris images for input to a commercial matcher. With this method, a match score distribution mean improvement of 11.65% for 30 degree images, 44.94% for 40 degree images, and 146.1% improvement for 50 degree images is observed versus match score distributions with unmodified images.

  13. Metamaterials with angle selective emissivity in the near-infrared.

    Science.gov (United States)

    Bossard, Jeremy A; Werner, Douglas H

    2013-03-11

    Metamaterials have been previously studied for their ability to tailor the dispersive IR emissivity of a surface. Here, we investigate two metamaterial structures based on an electromagnetic band-gap surface and a dielectric resonator array for use as near-IR emitters with custom angle selectivity. A genetic algorithm is successfully employed to optimize the metamaterial structures to have minimum emissivity in the normal direction and high emissivity at custom off-normal angles specified by the designer. Two symmetry conditions are utilized to achieve emissivity patterns that are azimuthally stable or distinct in the two orthogonal plane cuts. PMID:23482092

  14. The misalignment angle in vessel-mounted ADCP

    Directory of Open Access Journals (Sweden)

    Robert Osinski

    2000-09-01

    Full Text Available A description of the misalignment angle and the consequences if it occurs is given. It is shown that because of gyrocompass errors, the misalignment angle error a has to be computed for each cruise. A simple method of calibrating the acoustic Doppler current profiler (ADCP mounted on a vessel has been devised by fitting the cosinusoidal function. This is a post-processing method, suitable for calibrating previously collected data. Nevertheless, because of ADCP's constructional peculiarities, the procedure must be repeated for each cruise.

  15. Frictional adhesion: A new angle on gecko attachment.

    Science.gov (United States)

    Autumn, K; Dittmore, A; Santos, D; Spenko, M; Cutkosky, M

    2006-09-01

    Directional arrays of branched microscopic setae constitute a dry adhesive on the toes of pad-bearing geckos, nature's supreme climbers. Geckos are easily and rapidly able to detach their toes as they climb. There are two known mechanisms of detachment: (1) on the microscale, the seta detaches when the shaft reaches a critical angle with the substrate, and (2) on the macroscale, geckos hyperextend their toes, apparently peeling like tape. This raises the question of how geckos prevent detachment while inverted on the ceiling, where body weight should cause toes to peel and setal angles to increase. Geckos use opposing feet and toes while inverted, possibly to maintain shear forces that prevent detachment of setae or peeling of toes. If detachment occurs by macroscale peeling of toes, the peel angle should monotonically decrease with applied force. In contrast, if adhesive force is limited by microscale detachment of setae at a critical angle, the toe detachment angle should be independent of applied force. We tested the hypothesis that adhesion is increased by shear force in isolated setal arrays and live gecko toes. We also tested the corollary hypotheses that (1) adhesion in toes and arrays is limited as on the microscale by a critical angle, or (2) on the macroscale by adhesive strength as predicted for adhesive tapes. We found that adhesion depended directly on shear force, and was independent of detachment angle. Therefore we reject the hypothesis that gecko toes peel like tape. The linear relation between adhesion and shear force is consistent with a critical angle of release in live gecko toes and isolated setal arrays, and also with our prior observations of single setae. We introduced a new model, frictional adhesion, for gecko pad attachment and compared it to existing models of adhesive contacts. In an analysis of clinging stability of a gecko on an inclined plane each adhesive model predicted a different force control strategy. The frictional adhesion

  16. Quartz-Enhanced Photoacoustic Spectroscopy with Right-Angle Prism

    OpenAIRE

    Yongning Liu; Jun Chang; Jie Lian; Zhaojun Liu; Qiang Wang; Zengguang Qin

    2016-01-01

    A right-angle prism was used to enhance the acoustic signal of a quartz-enhanced photoacoustic spectroscopy (QEPAS) system. The incident laser beam was parallelly inverted by the right-angle prism and passed through the gap between two tuning fork prongs again to produce another acoustic excitation. Correspondingly, two pairs of rigid metal tubes were used as acoustic resonators with resonance enhancement factors of 16 and 12, respectively. The QEPAS signal was enhanced by a factor of 22.4 co...

  17. Small-angle anisotropies in the CMBR from active sources

    CERN Document Server

    Battye, R A

    1997-01-01

    We consider the effects of photon diffusion on the small-angle microwave background anisotropies due to active source models. We find that fluctuations created just before the time of last scattering allow anisotropy to be created on scales much smaller than allowed by standard Silk damping. Using simple models for string and texture structure functions as examples, we illustrate the differences in the angular power spectrum at scales of order a few arcminutes. In particular, we find that the Doppler peak heights are modified by 10-50% and the small-angle fall-off is power law rather than exponential.

  18. Measuring the Stop Mixing Angle at the LHC

    CERN Document Server

    Rolbiecki, Krzysztof; Moortgat-Pick, Gudrid

    2009-01-01

    We present a method to determine the stop mixing angle and its CP-violating phase at the LHC. As an observable we use ratios of branching ratios for different decay modes of the light stop ~t_1 to charginos and neutralinos. These observables can have a very strong dependence on the parameters of the stop sector. We discuss in detail the origin of these effects. Using various combinations of the ratios of branching ratios we show that, depending on the scenario, one can achieve accuracies in the range of a few percent for determining the light stop mass, the mixing angle and the CP phase.

  19. Structure and Inclination Angle of the Spiral Galaxy M31

    Institute of Scientific and Technical Information of China (English)

    MA Jun

    2001-01-01

    The mathematical form, the symmetry of the spiral structure, and the projection of the galactic disc on the image of the spiral galaxy M31 have been directly studied. It is found that M31 has two symmetric arms, i.e. the pitch angles of the two arms are nearly equal; these are 7.7° and 8.0°, respectively. Using the method proposed in this letter, the inclination angle of the galactic disc ofM31 is also obtained, which is 77.5° and is in good agreement with previously published results.

  20. Changes of concave and convex rib-vertebral angle, angle difference and angle ratio in patients with right thoracic adolescent idiopathic scoliosis.

    Science.gov (United States)

    Canavese, Federico; Turcot, Katia; Holveck, Jerôme; Farhoumand, Agnés Dahl; Kaelin, André

    2011-01-01

    The aim of this study is to describe the radiological changes in rib-vertebral angles (RVAs), rib-vertebral angle differences (RVADs), and rib-vertebral angle ratios (RVARas) in patients with untreated right thoracic adolescent idiopathic scoliosis and to compare with the normal subjects. The concave and convex RVA from T1 to T12, the RVADs and the RVARas were measured on AP digital radiographs of 44 female patients with right convex idiopathic scoliosis and 14 normal females. Patients were divided into three groups: normal subjects (group 1), scoliotic patients with Cobb's angle equal or <30° (group 2) and scoliotic patients with Cobb's angle over 30° (group 3). Overall values (mean ± SD) of the RVAs on the concave side were 90.5° ± 17° in group 1, 90.3° ± 15.8° in group 2 and 88.8° ± 15.4° in group 3. On the convex side, values were 90.0° ± 17.3° in group 1, 86.3° ± 13.7° in group 2 and 80.7° ± 14.4° in group 3. Overall values (mean ± SD) of the RVADs at all levels were 0.5° ± 0.7° in group 1, 4.0° ± 4.8° in group 2 and 8.0° ± 4.0° in group 3. The RVARa values (mean ± SD) at all levels was 1.008° ± 0.012° in group 1, 1.041° ± 0.061° in group 2 and 1.102° ± 0.151° in group 3. RVAD and RVARa values in the scoliotic segment were greater in patients with untreated scoliosis over 30° than in patients with an untreated deformity of <30° or normal subjects. A significant effect between groups was observed for the RVA, RVAD and RVARa variables. Measurement of RVA, RVAD and RVARa should not only be performed at and around the apex of a thoracic spinal deformity, but also extended to the whole thoracic spine. PMID:20811755

  1. Secondary instabilities of linearly heated falling films

    Institute of Scientific and Technical Information of China (English)

    HU Jun; SUN Dejun; HU Guohui; YIN Xieyuan

    2005-01-01

    Secondary instabilities of linearly heated failing films are studied through three steps. Firstly, the analysis of the primary linear instability on Miladinova's long wave equation of the linearly heated film is performed. Secondly, the similar Landau equation is derived through weak nonlinear theory, and a two-dimensional nonlinear saturation solution of primary instability is obtained within the weak nonlinear domain. Thirdly, the secondary (three-dimensional) instability of the two-dimensional wave is studied by the Floquet theorem.Our secondary instability analysis shows that the Marangoni number has destabilization effect on the secondary instability.

  2. Shared Spectrum Throughput for Secondary Users

    Directory of Open Access Journals (Sweden)

    Pratik Gandhi

    2014-04-01

    Full Text Available The throughput performance of secondary users sharing radio spectrum with a licensed primary user is analyzed in this work. An asynchronous transmission, sensing and backoff protocol is proposed for the secondary user and modeled as a six state Markov process. The model parameters are derived as a function of the duty cycle and average duration that the channel is unoccupied by the primary user. The secondary user parameters include its continuous transmission duration or packet size and its backoff window size. The model results show that the probabilities of the secondary user being in the transmit state are relatively invariant to the duty cycle compared to the probability of being in the backoff state, particularly at low to moderate secondary packet sizes. The secondary user throughput is expressed as a function of the aforementioned parameters and shown to change significantly with duty cycle and secondary packet sizes. It is found that at very low duty cycles, the throughput variation is insensitive to backoff duration being random or fixed. The proposed transmission and sensing method is also shown to outperform a periodic sensing protocol. The regions of the parameter space wherein the backoff and retransmit probabilities of the secondary user are bounded by specified performance metrics are derived. The sensitivity of the throughput in the presence of a cooperative and non- cooperative secondary user is also investigated.

  3. Secondary Instability of Stationary Crossflow Vortices in Mach 6 Boundary Layer Over a Circular Cone

    Science.gov (United States)

    Li, Fei; Choudhari, Meelan M.; Paredes-Gonzalez, Pedro; Duan, Lian

    2015-01-01

    Hypersonic boundary layer flows over a circular cone at moderate incidence can support strong crossflow instability. Due to more efficient excitation of stationary crossflow vortices by surface roughness, such boundary layer flows may transition to turbulence via rapid amplification of the high-frequency secondary instabilities of finite amplitude stationary crossflow vortices. The amplification characteristics of these secondary instabilities are investigated for crossflow vortices generated by an azimuthally periodic array of roughness elements over a 7-degree half-angle circular cone in a Mach 6 free stream. Depending on the local amplitude of the stationary crossflow mode, the most unstable secondary disturbances either originate from the second (i.e., Mack) mode instabilities of the unperturbed boundary layer or correspond to genuine secondary instabilities that reduce to stable disturbances at sufficiently small amplitudes of the stationary crossflow vortex. The predicted frequencies of dominant secondary disturbances are similar to those measured during wind tunnel experiments at Purdue University and the Technical University of Braunschweig, Germany.

  4. Small angle neutron scattering and small angle X-ray scattering studies of platinum-loaded carbon foams

    Indian Academy of Sciences (India)

    P U Sastry; V K Aswal; A G Wagh

    2008-11-01

    The morphology of carbon nanofoam samples comprising platinum nanoparticles dispersed in the matrix was characterized by small angle neutron scattering (SANS) and small angle X-ray scattering (SAXS) techniques. Results show that the structure of pores of carbon matrix exhibits a mass (pore) fractal nature and the average radius of the platinum particles is about 2.5 nm. The fractal dimension as well as the size distribution parameters of platinum particles varies markedly with the platinum content and annealing temperature. Transmission electron micrographs of the samples corroborate the SANS and SAXS results.

  5. Modeling the effects of anode secondary electron emission on transmitted current in crossed-field diodes

    Science.gov (United States)

    Gopinath, Venkatesh; Vanderberg, Bo

    1996-11-01

    Recent experimental measurements of transmitted current in a crossed-field switch by Vanderberg and Eninger ( B. H. Vanderberg and J. E. Eninger, ``Space-charge limited current cut-off in crossed fields,'' presented at IEEE ICOPS'95, Madison, Wi. ) have shown that the measured values of transmitted current are significantly smaller than the theoretically predicted limit. The experiments also showed larger decrease in transmitted current for higher magnetic fields, implying an effect due to the higher angle of incidence of incident electrons (i.e., at values of B closer to B_H). Studies by Verboncoeur and Birdsall ( J. P. Verboncoeur and C. K. Birdsall. ``Rapid current transition in a crossed-field diode,'' Phys. Plasmas 3) 3, March 1996. have shown that even small amount ( < 1%) of over injection in a crossed-field diode near cut-off led to substantial decrease in transmitted current. In our current work, we show that the same effect can be triggered by the presence of secondary electron emission from the anode. This study models the dependence of emission upon incident electron angle and energy. Since the yield of secondary electrons increases with incident angle, this model follows the experimental results as B approaches B_Hull accurately. This work was supported in part by ONR under grant FD-N00014-90-J-1198

  6. Secondary Subacromial Impingement after Valgus Closing-Wedge Osteotomy for Proximal Humerus Varus

    Directory of Open Access Journals (Sweden)

    Hirotaka Sano

    2015-01-01

    Full Text Available A 31-year-old construction worker had been suffering from both the motion pain and the restriction of elevation in his right shoulder due to severe varus deformity of humeral neck, which occurred after proximal humeral fracture. The angle for shoulder flexion and abduction was restricted to 50 and 80 degrees, respectively. Valgus closing-wedge osteotomy followed by the internal fixation using a locking plate was carried out at 12 months after injury. Postoperatively, the head-shaft angle of the humerus improved from 65 to 138 degrees. Active flexion and abduction angles improved from 80 to 135 degrees and from 50 to 135 degrees, respectively. However, the patient complained from a sharp pain with a clicking sound during shoulder abduction even after removal of the locking plate. Since subacromial steroid injection temporarily relieved his shoulder pain, we assumed that the secondary subacromial impingement was provoked after osteotomy. Thus, arthroscopic subacromial decompression was carried out at 27 months after the initial operation, which finally relieved his symptoms. In the valgus closing-wedge osteotomy, surgeons should pay attention to the condition of subacromial space to avoid causing the secondary subacromial impingement.

  7. Some imaging strategies in multi-angle spatial compounding

    DEFF Research Database (Denmark)

    Wilhjelm, Jens E.; Jensen, M. S.; Brandt, T.;

    2000-01-01

    Multi-angle compound images were generated with four schemes: mean, median, root-mean-square and geometric mean. The in vitro images, based on formalin fixed porcine tissue, were analyzed by visual inspection and by calculation of speckle contrast and contrast between different tissues. The mean...

  8. Systemic antihypertensive medication and incident open-angle glaucoma

    NARCIS (Netherlands)

    Muskens, Rogier P. H. M.; de Voogd, Simone; Wolfs, Roger C. W.; Witteman, Jacqueline C. M.; Hofman, Albert; de Jong, Paulus T. V. M.; Stricker, Bruno H. C.; Jansonius, Nomdo M.

    2007-01-01

    Purpose: To determine the association between systemic anti hypertensive medication and incident open-angle glaucoma. Design: Prospective population-based cohort study. Participants: The study population consisted of a subset of 3842 participants of the Rotterdam Study for whom data from identical o

  9. Installation of NA62 Large Angle Veto detectors

    CERN Multimedia

    2012-01-01

    In May 2012, the NA62 collaboration has installed the first eight (out of 12) Large Angle Veto detectors for the accurate identification of photons. These subdetectors will re-use 3000 lead glass crystals with attached photomultipliers from the OPAL experiment at LEP – CERN’s former accelerator.

  10. Method on camouflaged target recognition using the angle of ellipsometry

    Science.gov (United States)

    Zhuansun, Xiao-bo; Wu, Wen-Yuan; Huang, Yan-hua; Li, Zhao-zhao

    2015-10-01

    Using polarimetric information of the camouflaged target surface to identify camouflage has been a hot research area in camouflage detecting. The main method is to use the difference in the degree of polarization(DOP) between background and target to add the contrast ratio of them. The measurement of the DOP has some requirements on the intensity of reflected radiation. In case of low reflected radiation intensity, the difference in the DOP for different materials is not so distinguishable. In addition, the linear degree of polarization is largely under the effects of detection angle and surface roughness, so it is hard to differentiate the degree of polarization when the targets with similar surface roughness are detected at the same detection angle. By analyzing the elements affecting the reflected electromagnetic radiation amplitudes and phase on the camouflaged target surface, this article makes a research on the polarization character of reflected radiation A method on camouflaged target recognition directly or indirectly by taking the angle of ellipsometry (AOE) imaging under the linear polarized light. The function model of the angle of incidence, complex refractive index and AOE was modeled, then the model was simulated by MATLAB and the results showed it can describe the distribution properties of AOE. A new thought for the approach of identifying camouflaged target recognition by detecting polarimetric information was proposed, and it has a deep theoretical and practical significance in camouflaged target recognition.

  11. Non-linear Flight Dynamics at High Angles of Attack

    DEFF Research Database (Denmark)

    Granasy, P.; Sørensen, C.B.; Mosekilde, Erik;

    1998-01-01

    The methods of nonlinear dynamics are applied to the longitudinal motion of a vectored thrust aircraft, in particular the behavior at high angles of attack. Our model contains analytic nonlinear aerodynamical coefficients based on NASA windtunnel experiments on the F-18 high-alpha research vehicl...

  12. Progress in small angle neutron scattering activities in Malaysia

    Energy Technology Data Exchange (ETDEWEB)

    Abdul Aziz Bin Mohamed; Azali Bin Muhamad; Shukri Bin Mohd [Malaysian Institute for Nuclear Technology Research (MINT), Bangi, Kajang (Malaysia)

    1999-10-01

    The current status of SANS (Small Angle Neutron Scattering facility) activities in Malaysia has been presented. Many works need to be done for system improvement before the system can be confidently used as one of effective quality control tools in materials production and engineering sectors. (author)

  13. Head Angle and Elevation in Classroom Environments: Implications for Amplification

    Science.gov (United States)

    Ricketts, Todd Andrew; Galster, Jason

    2008-01-01

    Purpose: The purpose of this study was to examine children's head orientation relative to the arrival angle of competing signals and the sound source of interest in actual school settings. These data were gathered to provide information relative to the potential for directional benefit. Method: Forty children, 4-17 years of age, with and without…

  14. The Power of Pictures : Vertical Picture Angles in Power Pictures

    NARCIS (Netherlands)

    Giessner, Steffen R.; Ryan, Michelle K.; Schubert, Thomas W.; van Quaquebeke, Niels

    2011-01-01

    Conventional wisdom suggests that variations in vertical picture angle cause the subject to appear more powerful when depicted from below and less powerful when depicted from above. However, do the media actually use such associations to represent individual differences in power? We argue that the d

  15. IMU-Based Joint Angle Measurement for Gait Analysis

    Directory of Open Access Journals (Sweden)

    Thomas Seel

    2014-04-01

    Full Text Available This contribution is concerned with joint angle calculation based on inertial measurement data in the context of human motion analysis. Unlike most robotic devices, the human body lacks even surfaces and right angles. Therefore, we focus on methods that avoid assuming certain orientations in which the sensors are mounted with respect to the body segments. After a review of available methods that may cope with this challenge, we present a set of new methods for: (1 joint axis and position identification; and (2 flexion/extension joint angle measurement. In particular, we propose methods that use only gyroscopes and accelerometers and, therefore, do not rely on a homogeneous magnetic field. We provide results from gait trials of a transfemoral amputee in which we compare the inertial measurement unit (IMU-based methods to an optical 3D motion capture system. Unlike most authors, we place the optical markers on anatomical landmarks instead of attaching them to the IMUs. Root mean square errors of the knee flexion/extension angles are found to be less than 1° on the prosthesis and about 3° on the human leg. For the plantar/dorsiflexion of the ankle, both deviations are about 1°.

  16. Improved Angle Potentials for Coarse-Grained Molecular Dynamics Simulations

    NARCIS (Netherlands)

    Bulacu, Monica; Goga, Nicolae; Zhao, Wei; Rossi, Giulia; Monticelli, Luca; Periole, Xavier; Tieleman, D. Peter; Marrink, Siewert J.

    2013-01-01

    Potentials routinely used in atomistic molecular dynamics simulations are not always suitable for modeling systems at coarse-grained resolution. For example, in the calculation of traditional torsion angle potentials, numerical instability is often encountered in the case of very flexible molecules.

  17. 73m in ocean-going squid angling boat

    Institute of Scientific and Technical Information of China (English)

    Jin Yue

    2004-01-01

    @@ Dalian Fishing Vessel Co., Dalian, China Liaoning Province Sea Fishery Group entrusted Dalian Fishing Vessel Company with working design and technical design of squid angling boat whose model is 8356, and Dalian Fishing Vessel Company is in charge of construction. The summary of this paper is about the characteristics of overall system design of this ship.

  18. Combined surgical management of mandibular angle prominence and microgenia

    International Nuclear Information System (INIS)

    Chin play a very important role in facial aesthetics. Different deformities of volume and of position may occur at this level and it is the microgenia one of the more frequent. Treatment options include the use of silicone, alloplasty materials and autologous bone graft. Authors report the use of the bone removed from mandibular angle to increase the chin. This is the case of a white female patient aged 18 seen by the Orthognathics Multidisciplinary Staff of 'V. I. Lenin' Hospital due to its uncommon face width. The corresponding physical examination as well as the complementary ones diagnosed a bilateral prominence of mandibular angle associated with a microgenia. Surgery carried out was of remodeling type of both mandibular angles and genioplasty of height increase and a discrete advancement using the bone removed from the gonion. There were satisfactory aesthetic results without evidence of bone reabsorption. We conclude that use of autologous graft of mandibular angle is an effective treatment alternative for correction of microgenia. (author)

  19. Small angle X-ray scattering from hydrating tricalcium silicate

    International Nuclear Information System (INIS)

    The small-angle X-ray scattering technique was used to study the structural evolution of hydrated tricalcium silicate at room temperature. The changes in specific area of the associated porosity and the evolution of density fluctuations in the solid hydrated phase were deduced from the scattering data. A correlation of these variations with the hydration mechanism is tried. (Author)

  20. Reflectivity Model of Low Grazing Angle Radar Sea Clutter

    Institute of Scientific and Technical Information of China (English)

    FENG Sheng; CHEN Jie; CAI Tao; TU Xu-yan

    2005-01-01

    The commonly used reflectivity models of radar sea clutter are summarized. Among these models, the adjusted Barton model and the adjusted Morchin model are compared. From the analysis result, the γ-p reflectivity model is presented for low grazing angle radar sea clutter by the adjustment of the original Barton reflectivity model. The model takes into account radar frequency, grazing angle, sea condition, and polarization property. The influences of these factors on the proposed model are analyzed. The model absorbs the merits from commonly used reflectivity models for sea clutter. It introduces several researchers' opinions, and extends them. And it accounts for the reflectivity at arbitrary radar frequency from VHF to X-band, arbitrary low grazing angle, arbitrary sea condition and different polarization property. One of the main results is the proposed γ-p reflectivity model can reflect the influence of polarization on sea clutter reflectivity to some extent. The proposed γ-p reflectivity model of low-angle radar-sea clutter is validated by comparing the simulated and statistically experimental data.