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Sample records for acute tarsal tunnel

  1. Tenosynovial osteochondromatosis of the tarsal tunnel

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    Sugimoto, Kazuya; Iwai, Makoto [Department of Orthopaedic Surgery, Saiseikai Nara Hospital, 4-643 Hachijo, Nara-shi, Nara (Japan); Kawate, Kenji; Yajima, Hiroshi; Takakura, Yoshinori [Department of Orthopaedic Surgery, Nara Medical University, 840 Shijo-cho, Kashihara-shi, Nara (Japan)

    2003-02-01

    A case of tenosynovial osteochondromatosis in the tarsal tunnel in a 23-year-old man is presented. The lesion was treated surgically, and multiple osteochondromas were excised, which had no continuity with any tarsal bone or joint cavity but did with the sheaths of the flexor digitorum longus and flexor hallucis longus. Histologic examination of the lesion showed a fibrous capsule, hyaline cartilage and extensive areas of cancellous bone. Necrosis and mitosis were absent in the hyaline cartilage and there were no synovial nodules indicative of synovial metaplasia. The macroscopic findings showed ''end-stage'' tenosynovial osteochondromatosis. There was no evidence of recurrence 5 years after operation, and the patient remains free of symptoms. (orig.)

  2. Tarsal tunnel syndrome in patients with rheumatoid arthritis ...

    African Journals Online (AJOL)

    Ibrahim Khalil Ibrahim

    2013-01-10

    Jan 10, 2013 ... mal origin of the flexor retinaculum and its exit from the tarsal tunnel, where the plantar nerves pierce the abductor ... abductor digiti quinti pedis muscle, stimulating the tibial nerve proximal to the tarsal tunnel at the medial .... mass index BMI), lower limb edema. Fifteen feet of age and sex matched normal ...

  3. Tarsal tunnel disease and talocalcaneal coalition: MRI features

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    FitzGerald Alaia, Erin; Rosenberg, Zehava Sadka; Bencardino, Jenny T.; Ciavarra, Gina A.; Petchprapa, Catherine N. [New York University Langone Medical Center, New York, NY (United States); Rossi, Ignacio [New York University Langone Medical Center, New York, NY (United States); Centro de Diagnostico Dr. Enrique Rossi, Buenos Aires (Argentina)

    2016-11-15

    To assess, utilizing MRI, tarsal tunnel disease in patients with talocalcaneal coalitions. To the best of our knowledge, this has only anecdotally been described before. Sixty-seven ankle MRIs with talocalcaneal coalition were retrospectively reviewed for disease of tendons and nerves of the tarsal tunnel. Interobserver variability in diagnosing tendon disease was performed in 30 of the 67 cases. Tarsal tunnel nerves were also evaluated in a control group of 20 consecutive ankle MRIs. Entrapment of the flexor hallucis longus tendon (FHL) by osseous excrescences was seen in 14 of 67 cases (21 %). Attenuation, split tearing, tenosynovitis, or tendinosis of the FHL was present in 26 cases (39 %). Attenuation or tenosynovitis was seen in the flexor digitorum longus tendon (FDL) in 18 cases (27 %). Tenosynovitis or split tearing of the posterior tibial tendon (PT) was present in nine cases (13 %). Interobserver variability ranged from 100 % to slight depending on the tendon and type of disease. Intense increased signal and caliber of the medial plantar nerve (MPN), indicative of neuritis, was seen in 6 of the 67 cases (9 %). Mildly increased T2 signal of the MPN was seen in 15 (22 %) and in 14 (70 %) of the control group. Talocalcaneal coalitions may be associated with tarsal tunnel soft tissue abnormalities affecting, in decreasing order, the FHL, FDL, and PT tendons, as well as the MPN. This information should be provided to the referring physician in order to guide treatment and improve post-surgical outcome. (orig.)

  4. The value of MRI iniIdiopathic tarsal tunnel syndrome by measuring the cross-sectional area of tarsal tunnel

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    Kim, Min Jung; Jeong, Yu Mi; Lee, Sheen Woo; Choi Seung; Kim, Jeong Ho; Park, Hong Gi [Gachon University, Gil Hospital, Incheon (Korea, Republic of)

    2015-03-15

    The purpose of this study was to evaluate the use of MRI as a diagnostic test in tarsal tunnel syndrome. There are no published reports with this aim and no diagnostic standard for idiopathic tarsal tunnel syndrome (TTS) using imaging modalities. We retrospectively searched our Picture Archiving and Communication System data and medical records to identify patients who were clinically and electomyographically diagnosed with idiopathic TTS without space-occupying lesion on MRI. Twenty five patients were included in the patient group. Another twenty-five patients who underwent ankle MRI for Achilles tendon disease were selected and included in the control group. Cross-sectional areas (CSA) of tarsal tunnel were manually measured independently by two radiologists who were blinded to clinical and surgical results, using three-dimensional reconstruction software in our hospital. Measurements were done on axial images at three levels (level 1, tibiotalar joint level; level 2, medial malleolar tip level; level 3, sustentaculum tali level). Patient and control group data were statistically analyzed by the Mann-Whitney test. The mean values of CSA at levels 1, 2, and 3 of the tarsal tunnel were 87.8 mm2, 98.2 mm2, and 105.2 mm2, respectively in the patient group; and 100.0 mm2, 113.8 mm2, and 127.9 mm2 in the control group, respectively, in reader 1; and 86.2 mm2, 97.6 mm2, 105.2 mm2, respectively in the patient group; and 99.7 mm2, 112.3 mm2, 124.4 mm2, respectively, in the control group, in reader 2. The mean CSA in the patient group was significantly less than that of the control group at all three levels (p < 0.05). Intra-class correlation coefficient value between reader 1 and reader 2 were 0.98 in group 1, and 0.97 in group 2, respectively. MRI can be helpful in the assessment of idiopathic tarsal tunnel syndrome. CSA measurements of tarsal tunnel at each level may predict TTS even though there are no space occupying lesions in the tarsal tunnel on MRI.

  5. ANALYSIS OF TARSAL TUNNEL SYNDROME USING IMAGE CORRELATION

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    Amarjot Singh

    2013-11-01

    Full Text Available Tarsal tunnel syndrome (TTS, also known as posterior tibial neuralgia is a painful disorder of the foot. It is a medical condition arising due to the compression of the tibial nerve in the tarsal tunnel, resulting in numbness, parenthesis and muscle weakness in foot. A number of imaging methodologies such as ultrasound as well as MRI imaging has been used in the past in order to analyze the strain pattern of gastrocnemius tendon and aponeurosis from the surface of the skin without analyzing the internal tendons. The DIC code developed, computes the in-plane strain with a correlation function using pictures taken before and after stretching, using a CCD camera. The shift between the initial picture and subsequent one is evaluated by cross-correlation using FFT. This paper gives in detail description of the preprocessing steps necessary to extract Zone of Interest from the two images. The effects of stretching on the superficial components of the tibial nerve, the posterior tibial artery and vein, and the tibialis posterior, flexor digitorum longus and flexor hallucis longus tendons in the calf and foot are studied.

  6. Bilateral Tarsal Tunnel Syndrome Due To Bilateral Lipoma: A Case Report

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    C. Eren CANSÜ, İstemi YÜCEL, Kutay ÖZTURAN

    2010-11-01

    Full Text Available Tarsal tunnel syndrome is an entrapment neuropathy of posterior tibial nerve under the flexorretinaculum. Patients generally present with paresthesias on the plantar side of foot and fingersand in the distal kruris.The causes of tarsal tunnel syndrome are space occupying lesions within or around the tunnelwhich exert pressure to the nerve, ankle deformities, systemic illnesses, trauma or lesions ofthe nerve itself.In this study a case of tarsal tunnel syndrome due to bilateral lipoma which was treated surgicallyis presented.

  7. Case Study of Oriental Medicine Treatment with acupotomy Therpy of the Tarsal tunnel Syndrome

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    Lim Na-ra

    2009-03-01

    Full Text Available Purpose : In order to estimate clinical effects of Oriental Medicine Treatment with acupotomy therapy of Tarsal tunnel Syndrome Methods : From 5th November, 2008 to 8th November, 2008, 1 male patient diagnosed as Tarsal tunnel syndrome(clinical diagnosed was treated with general oriental medicine therapy (acupuncture, moxibustion, cupping, physical therapy, herbal medication and acupotomy. Results : The patient's Rt foot paresthesia, pain were remarkably improved. Conclusions : This study demonstrates that oriental medical treatment with acuputomy therapy has notable effect in improving symptoms of tarsal tunnel syndrome. as though we had not wide experience in this treatment, more research is needed.

  8. [Tarsal tunnel syndrome. Review of the topic as a result of one case].

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    López-Gavito, E; Parra-Téllez, P; Cornejo-Olvera, R; Vázquez-Escamilla, J

    2014-01-01

    The first description of tarsal tunnel is attributed to Richter in 1897, in 1932 Pollock and Davis described the syndrome for the first time, in 1960 Kopell and Thompson described the clinical features of tarsal tunnel syndrome; and in 1962 Charles Keck described tarsal tunnel syndrome in a detailed manner with clinical cases. We present the case of a 61 year old female patient who presented symptoms in 2010, she had intermittent talalgia that increased gradually, six months later pain is constant and limiting gait, EVA is 6/10, she is diagnosed with plantar fasciitis and is referred to physiotherapy with no improvement after two months of treatment. The plantar fascia ultrasound reports thickening with micro tears in the heel bone attachment, we infiltrated the plantar fascia with platelet rich plasma with no improvement, two months later she has shock wave sessions with no changes observed. We reassess the case and make the diagnosis of tarsal tunnel syndrome clinically and with electromyography and in 2011 we infiltrate a steroid with local anesthesia with temporary improvement. In 2012, we found an EVA of 7/10 and an AOFAS of 54 points, we perform surgery and the intraoperative finding is a varicose vein that decreased the caliber of the tarsal tunnel compressing adjacent structures. The clinical case is presented and we reviewed tarsal tunnel syndrome in the literature.

  9. Bilateral anterior tarsal tunnel syndrome variant secondary to extensor hallucis brevis muscle hypertrophy in a ballet dancer: a case report.

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    Tennant, Joshua N; Rungprai, Chamnanni; Phisitkul, Phinit

    2014-12-01

    We present a case of bilateral anterior tarsal tunnel syndrome secondary EHB hypertrophy in a dancer, with successful treatment with bilateral EHB muscle excisions for decompression. The bilateral presentation of this case with the treatment of EHB muscle excision is the first of its type reported in the literature. Copyright © 2014 European Foot and Ankle Society. Published by Elsevier Ltd. All rights reserved.

  10. Evaluation of peripheral microcirculation improvement of foot after tarsal tunnel release in diabetic patients by transcutaneous oximetry.

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    Trignano, Emilio; Fallico, Nefer; Chen, Hung-Chi; Faenza, Mario; Bolognini, Alfonso; Armenti, Andrea; Santanelli Di Pompeo, Fabio; Rubino, Corrado; Campus, Gian Vittorio

    2016-01-01

    According to recent studies, peripheral nerve decompression in diabetic patients seems to not only improve nerve function, but also to increase microcirculation; thus decreasing the incidence of diabetic foot wounds and amputations. However, while the postoperative improvement of nerve function is demonstrated, the changes in peripheral microcirculation have not been demonstrated yet. The aim of this study is to assess the degree of microcirculation improvement of foot after the tarsal tunnel release in the diabetic patients by using transcutaneous oximetry. Twenty diabetic male patients aged between 43 and 72 years old (mean age 61.2 years old) suffering from diabetic peripheral neuropathy with superimposed nerve compression underwent transcutaneous oximetry (PtcO2) before and after tarsal tunnel release by placing an electrode on the skin at the level of the dorsum of the foot. Eight lower extremities presented diabetic foot wound preoperatively. Thirty-six lower extremities underwent surgical release of the tibialis posterior nerve only, whereas four lower extremities underwent the combined release of common peroneal nerve, anterior tibialis nerve, and posterior tibialis nerve. Preoperative values of transcutaneous oximetry were below the critical threshold, that is, lower than 40 mmHg (29.1 ± 5.4 mmHg). PtcO2 values at one month after surgery (45.8 ± 6.4 mmHg) were significantly higher than the preoperative ones (P = 0.01). The results of postoperative increase in PtcO2 values demonstrate that the release of the tarsal tunnel determines a relevant increase in microcirculation in the feet of diabetic patients. © 2015 Wiley Periodicals, Inc.

  11. Tarsal Tunnel Syndrome

    Science.gov (United States)

    ... similar to an electrical shock Numbness Pain, including shooting pain Symptoms are typically felt on the inside ... the area to help determine if a small mass is present. Advanced imaging studies may be ordered ...

  12. Extensile decompression of the proximal and distal tarsal tunnel combined with partial plantar fascia release in the treatment of chronic plantar heel pain.

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    Mook, William R; Gay, Tenaja; Parekh, Selene G

    2013-02-01

    Chronic heel pain that is recalcitrant to nonoperative measures is a rare but disabling condition. There are no reports in the literature of extensile proximal and distal tarsal tunnel release combined with partial plantar fasciotomy in the treatment of chronic heel pain. We present our results. A retrospective chart review was conducted, and charts were assessed for details of their presenting complaints, physical exam, diagnostic studies, medical history, Visual Analog Scale (VAS) scores for pain, American Orthopaedic Foot and Ankle Society (AOFAS) ankle-hindfoot scores, and complications. The mean AOFAS ankle-hindfoot score was 86 ± 12.9 (range = 69-100). Of 15 heels, 10 (67%) had an excellent or good rating at the time of the last follow-up visit. One of 15 (7%) reported a poor outcome. The mean VAS pain score changed from 6.3 ± 3.1 to 1.4 ± 1.8 (P = .001). There were no wound complications or infections. This technique offers another operative option for chronic heel pain that is associated with satisfactory outcomes and rest pain relief. Despite reducing pain at rest in all patients, the majority of patients may be left with mild to moderate residual symptoms with activity that is similar to the outcomes of previously reported procedures.

  13. Third tarsal bone fractures in the greyhound.

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    Guilliard, M J

    2010-12-01

    To describe the signalment, morphology, response to treatment and prognosis of third tarsal bone fractures in the racing greyhound. All third tarsal bone fractures seen by the author over a ten year period were included in the study. Diagnosis was by radiography. Treatments were reconstruction with a lag screw, fragment removal, centrodistal joint arthrodesis or conservative management. Twenty-three cases were included in the study of which 16 cases were recent and seven cases chronic fractures. The chronic cases had been rested from between three and six months before an examination for recurrent lameness. There were five concomitant second tarsal bone fractures. Partial dorsal collapse was present in four cases. Thirteen dogs had lag screw fixation; three were lost to follow-up, seven returned to racing and three, all with partial tarsal collapse, failed to return to racing. Two dogs that had a centrodistal joint arthrodesis and one dog treated by rest alone raced again. Two dogs that had fragment removal failed to return to racing. Veterinary examination of greyhounds with third tarsal bone fractures is often not sought at the time of the initial injury due to the benign presenting signs. Recurrence of lameness after rest is common. The prognosis for a successful return to racing would appear to be good following fragment fixation in both acute and chronic cases without dorsal tarsal collapse. Centrodistal joint arthrodesis may encourage bone union. The prognosis for conconservatively treated cases is guarded. Fragment removal is not recommended as a treatment. © 2010 British Small Animal Veterinary Association.

  14. Acute carpal tunnel syndrome in a patient with haemophilia

    OpenAIRE

    Mayne, Alistair Ivan William; Howard, Anthony; Kent, Matthew; Banks, Joanne

    2012-01-01

    Acute carpal tunnel syndrome (CTS) is a rare surgical condition usually resulting from wrist trauma. We present the case of a young haemophilic man who developed acute CTS following trivial injury. The patient was initially managed conservatively but symptom progression resulted in carpal tunnel decompression. A literature review and management approach are presented. This is an important complication of haemophilia to be aware of as prompt conservative management can obviate the need for sur...

  15. Acute Cubital Tunnel Syndrome Secondary to Anconeus Epitrochlearis Muscle

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    Ying-Kan Law

    2015-12-01

    Full Text Available Cubital tunnel syndrome is the most common type of ulnar nerve entrapment that usually associates with chronic sensory and motor symptoms. Having anconeus epitrochlearis muscle is an uncommon cause of cubital tunnel syndrome. In this paper, the author introduces a case of cubital tunnel syndrome due to anconeus epitrochlearis muscle presenting with acute sensory, motor, and sympathetic symptoms. For such cases, there has been much controversy over the choices of surgical treatment, which can be excision of the muscle alone or together with ulnar nerve anterior transposition.

  16. [Characteristic and treatment of acute aggravating cubital tunnel syndrome].

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    Chen, Ran; Kan, Shilian; Li, Jin

    2015-11-03

    To investigate the causes and the characteristics of acute aggravating cubital tunnel syndrome. The enrolling criteria of subjects were as follows: (1) Patients with manifestation of cubital tunnel syndrome for more than 6 months; (2) acute exacerbation of the disease for no more than 4 weeks. The clinical data from March 2011 to December 2014 was collected and analyzed retrospectively. Twelve cases aged 52 to 65 met the enrolling criteria and were included in this study, and among them 10 patients were male, 2 were female; 5 cases were on the left and the other 7 on the right. All of them had some degree of cubital tunnel syndrome symptoms before the onset of acute exacerbation. When nerve decompression and anterior transposition of the ulnar nerve was performed, the elbow joint cysts which squeezed the ulnar nerve were found. The cysts were then resected. In all 12 cases, the compression symptoms of ulnar nerve were relieved after surgery. The mean follow up period was 13 months, ranging from 6 to 45 months. According to Gu Yudong functional evaluation criteria for cubital tunnel syndrome, 2 of the patients can be judged as "Excellent", 8 "good" and 2 "acceptable" at the follow-up. Cyst compression may induce the acute exacerbation of ulnar nerve symptom in patients with cubital tunnel syndrome. Early diagnosis and treatment is critical for these patients.

  17. Acute carpal tunnel syndrome in a patient with haemophilia

    Science.gov (United States)

    Mayne, Alistair Ivan William; Howard, Anthony; Kent, Matthew; Banks, Joanne

    2012-01-01

    Acute carpal tunnel syndrome (CTS) is a rare surgical condition usually resulting from wrist trauma. We present the case of a young haemophilic man who developed acute CTS following trivial injury. The patient was initially managed conservatively but symptom progression resulted in carpal tunnel decompression. A literature review and management approach are presented. This is an important complication of haemophilia to be aware of as prompt conservative management can obviate the need for surgery. This case is useful in (a) highlighting the importance of considering a patient's medical history when formulating differential diagnoses and (b) outlining a management approach to this condition. PMID:22761230

  18. Chronic tarsal conjunctivitis.

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    Cook, Nicholas; Mushtaq, Fizza; Leitner, Christina; Ilchyshyn, Andrew; Smith, George T; Cree, Ian A

    2016-07-29

    Toxicity is rarely considered in the differential diagnosis of conjunctivitis, but we present here a new form of toxic conjunctivitis with unusual clinical features. Between 2010 and 2013, a new clinical presentation of chronic conjunctivitis unresponsive to normal treatment was noted within a Primary Care Ophthalmology Service. Retrospective review of case records and histopathology results. A total of 55 adult patients, all females, presented with epiphora and stickiness. They did not complain of itch and had had symptoms for an average of 9 months. Clinical examination showed bilateral moderate to severe upper and lower tarsal conjunctival papillary reaction, without corneal or eyelid changes and mild bulbar conjunctival hyperaemia in a third of cases. Biopsies were taken in 15 cases to exclude an atypical infection or lymphoma. Histologically, there was a variable superficial stromal lymphocytic infiltrate, involving the epithelium in more severe cases. The majority of the cells were CD3 positive T-lymphocytes and follicle formation was not noted. The clinical history in all cases included prolonged use of eye make- up and other facial cosmetic products. Clinical symptoms of epiphora settled with topical steroid drops, but the clinical signs of chronic tarsal inflammation persisted until withdrawal of the facial wipes thought to contain the inciting agent, though the exact nature of this remains unclear. The presentation, appearances, histological features are consistent with a contact allergen-driven chronic conjunctivitis. Steroid treatment provided good relief of symptoms and patients were advised to avoid potential contact allergens. Management remains difficult. Further research into contact allergies of mucous membranes and identification of its allergens is required.

  19. Transmissions within the tarsal gearbox.

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    Wolf, Peter; Stacoff, Alex; Luechinger, Roger; Boesiger, Peter; Stuessi, Edgar

    2008-01-01

    The dependence of the movements of the calcaneus, cuboid, navicular, and talus on each other have been described as the tarsal gearbox. To provide a basis of its modeling, data on transmissions between tarsal joint rotations within this gearbox are required. The feasibility of tibiocalcaneal rotations to predict tarsal joint rotations is of interest because a meaningful relation would allow the use of common motion analysis with skin markers to investigate rearfoot kinematics. We performed linear regression analyses between tarsal joint and tibiocalcaneal rotations on the basis of magnetic resonance imaging of tibia and tarsal bone positions during quasi-static foot pronation and supination. In the frontal plane and transverse planes, linear models were found to predict tarsal joint rotations quite well (r(2) = 0.83-0.97 for the frontal plane and r(2) = 0.73-0.95 for the transverse plane). For each degree of talocalcaneal rotation, there was 1.8 degrees of talonavicular rotation in the frontal plane and 1.6 degrees in the transverse plane; each degree of talocalcaneal rotation resulted in 0.6 degrees of calcanealcuboid rotation in the frontal plane and 0.7 degrees in the transverse plane; each degree of calcaneocuboid rotation resulted in 3 degrees of talonavicular rotation in the frontal plane and 2.8 degrees in the transverse; each degree of tibiocalcaneal rotation resulted in 0.9 degrees of talocalcaneal rotation in the frontal plane and 0.9 degrees in the transverse plane; and each degree of tibiocalcaneal rotation resulted in 1.6 degrees of talonavicular rotation in the frontal plane and 1.3 degrees in the transverse plane. The present study provides a basis on which the tarsal gearbox in the frontal and the transverse planes under quasi-static conditions can be modeled. Furthermore, it is concluded that tibiocalcaneal rotations are practical for predicting tarsal joint rotations during quasi-static motions.

  20. [Acute carpal tunnel syndrome in a patient with Marfan syndrome].

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    Franke, J; Wenzel, W; Rehfuss, D; Keiner, H P; Manncke, K

    2008-05-01

    Acute carpal tunnel syndrome (ACTS) is rare and is mostly the result of fractures of the distal radius or the carpal bones. This paper gives the first report of an ACTS following contusion of the wrist as the result of an extensive haematoma of the flexor tendon sheath, which did not appear until 50 hours after the injury was sustained but then developed rapidly. The patient suffers from Marfan syndrome. This disease is associated with pathologic changes to the major vessels, and especially the aorta, and of the smaller peripheral vessels. It is assumed that the haematoma arose from an aneurysm of such a small vessel. The treatment of choice in ACTS is emergency incision of the carpal tunnel.

  1. Acute Carpal Tunnel Syndrome Caused by Diffuse Giant Cell Tumor of Tendon Sheath: A Case Report

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    Ward, Christina M; Lueck, Nathan E; Steyers, Curtis M

    2007-01-01

    A 46 year old male developed spontaneous acute carpal tunnel syndrome of the right wrist without any antecedent trauma. Surgical exploration revealed hemorrhage secondary to diffuse giant cell tumor of tendon sheath as the underlying cause. PMID:17907439

  2. Rhinosporidiosis of the tarsal conjunctiva

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    Akshay Gopinathan Nair

    2015-01-01

    Full Text Available Rhinosporidiosis is a rare infection caused by Rhinosporidium seeberi, an organism classified in its own class, mesomycetozoea. It commonly affects mucus membranes namely the nasal mucosa, pharynx and the conjunctiva. We present the case of an 8-year-old female who presented with a flat, red, vascular, fleshy, pedunculated mass arising from the tarsal conjunctiva of the right upper eyelid. The mass was completely excised. On histopathological examination, multiple sporangia were seen in various stages of degeneration, consistent with rhinosporidiosis. The diagnosis of rhinosporidiosis is based solely on its microscopic features, and the treatment is surgical excision. This condition is endemic in the temperate regions of the Indian subcontinent, but it has been known to occur even in the colder regions of North America and Eastern Europe. Although a rare clinical entity, the possibility of rhinosporidiosis must be borne in mind when evaluating any polypoidal conjunctival mass.

  3. Giant Tarsal Keratinous Cyst Mimicking Chalazion

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    Melis Palamar Onay

    2013-04-01

    Full Text Available Reports on keratinous cysts involving the tarsal plate are very rare. Herein, we present a 69-year-old male patient with a giant tarsal keratinous cyst of the right upper eyelid who was misdiagnosed as chalazion of the eyelid. Interventional case report with cytopathologic correlation. Due to recurrence after the surgery for presumed chalazion, the patient was referred to our clinic for tumor evaluation. In the second surgery, which was performed in our clinic, the lesion was found to have a fine capsule and was totally excised. Histopathologic examination revealed keratinous cyst of the tarsal plate. Keratinous cyst must be considered in the differential diagnosis of tarsal plate lesions, as the curettage of the keratinous cyst might result in multiple recurrences. (Turk J Ophthalmol 2013; 43: 138-9

  4. Giant epidermal cyst of the tarsal plate

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    Mohana Majumdar

    2012-01-01

    Full Text Available A 35-year-old male patient presented with a right upper eyelid mass with mechanical ptosis. The patient gave no history of trauma or surgery. On examination, there was a huge cystic mass fixed to the tarsal plate. Excisional biopsy with tarsectomy was done. Histopathology sections demonstrated a keratin-filled cyst arising from the tarsus. A thorough Pubmed search did not reveal an epidermal cyst of the tarsal plate of this size which was successfully managed. The incision was made in such a way that postoperative ptosis would be avoided. Excess skin was removed during the surgery.

  5. [Idiopathic loss of lateral tarsal suspension].

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    Troyano, J; Martín, E; Genol-Saavedra, I; García-Sánchez, J

    2007-06-01

    A 53-year-old man who showed a loss of tarsal suspension in the lateral third of both lower eyelids underwent lateral canthoplasty with a good post-operative result. Disinsertion of the union of the inferior tarsus with the lateral canthus, of unknown cause, is a very uncommon finding that has almost never been reported in the world literature. There are two cases described of eyelid elastolysis with loss of lateral tarsal suspension, as in our case, but both showed eyelid skin atrophy and had histopathologic confirmation. Our case did not have skin atrophy.

  6. TARSAL COALITIONS IN CHILDREN: DIAGNOSTICS AND TREATMENT

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    V. M. Kenis

    2011-01-01

    Full Text Available The incidence of this condition in general and pediatric population is up to 13%. Conservative and surgical correction of this type of deformity is widely discussed in literature. In the series of 35 patients with tarsal coalition the results of treatment are observed. Differentiated approach to nonsurgical and surgical treatment is described and discussed.

  7. Infarcted Tarsal Pyogenic Granuloma Simulating Malignant Melanoma.

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    Charles, Norman C; Kahn, Jonathan B

    The authors describe a rapidly enlarging, pedunculated brown tarsal lesion in a 34-year-old man with a history of chalazia. Following excision, histopathologic analysis showed the features of a necrotic pyogenic granuloma. This unique case expands the differential diagnosis of conjunctival malignant melanoma.

  8. Osteochondritis of the tarsal navicula: radioisotopic appearances.

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    McCauley, R G; Kahn, P C

    1977-06-01

    A case of Köhler's disease of the tarsal navicula is described as presenting with swelling, tenderness, and hyperthermia of the right foot. Scintigraphy revealed decreased uptake in the right midtarsal area. The ability of the pinhole collimator to image these tiny bones is demonstrated.

  9. Non-tunneled versus tunneled dialysis catheters for acute kidney injury requiring renal replacement therapy: a prospective cohort study.

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    Mendu, Mallika L; May, Megan F; Kaze, Arnaud D; Graham, Dionne A; Cui, Salena; Chen, Margaret E; Shin, Naomi; Aizer, Ayal A; Waikar, Sushrut S

    2017-12-04

    Acute kidney injury requiring renal replacement therapy (AKI-RRT) is associated with high morbidity, mortality and resource utilization. The type of vascular access placed for AKI-RRT is an important decision, for which there is a lack of evidence-based guidelines. We conducted a prospective cohort study over a 16-month period with 154 patients initiated on AKI-RRT via either a non-tunneled dialysis catheter (NTDC) or a tunneled dialysis catheter (TDC) at an academic hospital. We compared differences in renal replacement delivery and mechanical and infectious outcomes between NTDCs and TDCs. Patients who received TDCs had significantly better RRT delivery, both with continuous venovenous hemofiltration (CVVH) and intermittent hemodialysis (IHD), compared to patients who received NTDCs; these findings were confirmed after multivariable adjustment for AKI-specific disease severity score, history of chronic kidney disease, renal consult team, and AKI cause. In CVVH and IHD, the median venous and arterial blood flow pressures were significantly higher with TDCs compared to NTDCs (p RRT had improved RRT delivery and fewer mechanical complications. Initial TDC placement for AKI-RRT should be considered when not clinically contraindicated given the potential for improved RRT delivery and outcomes.

  10. Acute carpal tunnel syndrome of the hand following a cat bite.

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    Sbai, Mohamed Ali; Dabloun, Slim; Benzarti, Sofien; Khechimi, Myriam; Jenzeri, Abdesselem; Maalla, Riadh

    2015-01-01

    Cat bites at the hand are common situation in emergency departments. Neglected or poorly supported, these lesions sometimes lead to serious injuries that may compromise the function of the hand. Pasteurellamultocida is the most offending germ in these lesions, despite their sensitivity to antibiotics; it can sometimes lead to deep infections involving the skin, bones and joints. Acute carpal tunnel syndrome is exceptional after cat bite. We report a case of a 56 Year old female presenting with an acute carpal tunnel syndrome associated with compartment syndrome of the right hand 6 days after a cat bite of her right thumb. The patient was treated by surgery to relieve the median nerve. Microbiology identified PasteurellaMultocida.

  11. Central tarsal bone fracture in a cat.

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    Cinti, Filippo; Pisani, Guido; Penazzi, Claudio; Carusi, Umberto; Vezzoni, Luca; Vezzoni, Aldo

    2016-01-01

    Fracture of the central tarsal bone is an uncommon injury in dogs and occurs predominantly in racing Greyhounds. To the authors' knowledge, this type of fracture has not been described previously in cats. This case report describes a five-year-old Domestic Shorthair cat referred to the Centro Veterinario Luni Mare because of lameness, swelling and signs of pain in the right hindlimb caused by trauma. Clinical examination and diagnostic imaging revealed a right central tarsal bone fracture. Open reduction and internal fixation with a 2.0 mm position screw and two 0.8 mm Kirschner wires were carried out. The last follow-up examination three years postoperatively found the cat in good health with normal range of motion and function, and no signs of lameness in the right hindlimb.

  12. Isolated dorsal dislocation of the tarsal naviculum.

    Science.gov (United States)

    Hamdi, Kaziz; Hazem, Ben Ghozlen; Yadh, Zitoun; Faouzi, Abid

    2015-01-01

    Isolated dislocation of the tarsal naviculum is an unusual injury, scarcely reported in the literature. The naviculum is surrounded by the rigid bony and ligamentous support hence fracture dislocation is more common than isolated dislocation. The mechanism and treatment options remain unclear. In this case report, we describe a 31 year old man who sustained an isolated dorsal dislocation of the left tarsal naviculum, without fracture, when he was involved in a motor vehicle collision. The reported mechanism of the dislocation is a hyper plantar flexion force applied to the midfoot, resulting in a transient disruption of the ligamentous support of the naviculum bone, with dorsal displacement of the bone. The patient was treated with open reduction and Krischner-wire fixation of the navicular after the failure of closed reduction. The wires were removed after 6 weeks postoperatively. Physiotherapy for stiffness and midfoot pain was recommended for 2 months. At 6 months postoperatively, limping, midfoot pain and weakness were reported, no X-ray abnormalities were found. The patient returned to his obvious activities with a normal range of motion.

  13. Isolated dorsal dislocation of the tarsal naviculum

    Directory of Open Access Journals (Sweden)

    Kaziz Hamdi

    2015-01-01

    Full Text Available Isolated dislocation of the tarsal naviculum is an unusual injury, scarcely reported in the literature. The naviculum is surrounded by the rigid bony and ligamentous support hence fracture dislocation is more common than isolated dislocation. The mechanism and treatment options remain unclear. In this case report, we describe a 31 year old man who sustained an isolated dorsal dislocation of the left tarsal naviculum, without fracture, when he was involved in a motor vehicle collision. The reported mechanism of the dislocation is a hyper plantar flexion force applied to the midfoot, resulting in a transient disruption of the ligamentous support of the naviculum bone, with dorsal displacement of the bone. The patient was treated with open reduction and Krischner-wire fixation of the navicular after the failure of closed reduction. The wires were removed after 6 weeks postoperatively. Physiotherapy for stiffness and midfoot pain was recommended for 2 months. At 6 months postoperatively, limping, midfoot pain and weakness were reported, no X-ray abnormalities were found. The patient returned to his obvious activities with a normal range of motion.

  14. Vernal keratoconjunctivitis with giant papillae on the inferior tarsal conjunctiva.

    Science.gov (United States)

    Asada, Yosuke; Ebihara, Nobuyuki; Funaki, Toshinari; Yokoi, Norihiko; Murakami, Akira; Matsuda, Akira

    2014-01-01

    In vernal keratoconjunctivitis (VKC), giant papillae are commonly observed on the superior tarsal conjunctiva. We found 3 cases of giant papillae on the inferior tarsal conjunctiva, and diagnosed them as being VKC based on their clinical and histopathological features. Three patients with inferior tarsal giant papillae were studied. In 2 patients, the giant papillae were resected for therapeutic purposes. Immunohistochemical analysis was carried out by indirect immunofluorescent staining using anti-CD3, anti-CD20, anti-CD35 antibodies. In all 3 patients, giant papilla formation was observed on the inferior lid margin. Clusters of CD20 B lymphocytes with CD35 follicular dendritic cells, and CD3 marginal zone T lymphocytes, common features of lymphoid neogenesis, were observed. In 2 patients, typical giant papillary formation was also observed on the superior tarsal conjunctiva. In all the patients, topical dexamethasone and tacrolimus treatments were found to be effective. The giant papillae of VKC can occur not only on the superior tarsal conjunctiva but also on the inferior tarsal conjunctiva. The possibility of the presence of giant papillae on the inferior tarsal conjunctiva should be considered in the clinical examination of patients with VKC.

  15. Ligament structures in the tarsal sinus and canal.

    Science.gov (United States)

    Li, Shu-Yuan; Hou, Zhi-Dian; Zhang, Peng; Li, Hong-Liang; Ding, Zi-Hai; Liu, Yu-Jie

    2013-12-01

    The concrete anatomy and functional characteristics of the subtalar ligaments have been a matter of debate that some believe has hampered the progress of clinical ligament reconstruction. In 32 fresh-frozen cadaver feet, the course of the inferior extensor retinaculum (IER) and other subtalar ligaments was carefully measured and photographed both from the portal of the tarsal sinus and from a posterior view. The IER inserted inside the tarsal sinus and canal by means of 3 roots: a lateral, an intermediate, and a medial one. These roots, along with the tarsal canal, divided the subtalar space into 3 parts. In front of the IER and inside the tarsal sinus, the thick cervical ligament (CL) lay at a 45-degree angle to the calcaneus. Behind the IER and inside the posterior capsule, in most cases (25 of 32 specimens), the posterior capsular ligament (PCaL) lay directly in front of the posterior talocalcaneal facet. Inside the tarsal canal, the fan-shaped medial root of the IER spread from outside upper lateral to lower medial, and the interosseous talocalcaneal ligament (ITCL) ran from upper medial to lower lateral; fibers of these 2 ligaments blended tightly together to form a V-shaped ligament complex. Just anterior to this complex in some cases (20 of 32 specimens), a short narrow upright ligament, the tarsal canal ligament (TCL), was located behind the middle talocalcaneal joint. The results of this study show that the CL is the primary ligament in the tarsal sinus and that the ITCL is a thin single band rather than a strong bilaminar ligament located inside the tarsal canal. Instead, the medial root of the IER is the primary ligamentous structure in the tarsal canal. The anatomical description provided here may provide a more accurate theoretical foundation for clinical subtalar stability restoration.

  16. Computer keyboarding biomechanics and acute changes in median nerve indicative of carpal tunnel syndrome.

    Science.gov (United States)

    Toosi, Kevin K; Hogaboom, Nathan S; Oyster, Michelle L; Boninger, Michael L

    2015-07-01

    Carpal tunnel syndrome is a common and costly peripheral neuropathy. Occupations requiring repetitive, forceful motions of the hand and wrist may play a role in the development of carpal tunnel syndrome. Computer keyboarding is one such task, and has been associated with upper-extremity musculoskeletal disorder development. The purpose of this study was to determine whether continuous keyboarding can cause acute changes in the median nerve and whether these changes correlate with wrist biomechanics during keyboarding. A convenience sample of 37 healthy individuals performed a 60-minute typing task. Ultrasound images were collected at baseline, after 30 and 60 min of typing, then after 30 min of rest. Kinematic data were collected during the typing task. Variables of interest were median nerve cross-sectional area, flattening ratio, and swelling ratio at the pisiform; subject characteristics (age, gender, BMI, wrist circumference, typing speed) and wrist joint angles. Cross-sectional area and swelling ratio increased after 30 and 60 min of typing, and then decreased to baseline after 30 min of rest. Peak ulnar deviation contributed to changes in cross-sectional area after 30 min of typing. Results from this study confirmed a typing task causes changes in the median nerve, and changes are influenced by level of ulnar deviation. Furthermore, changes in the median nerve are present until cessation of the activity. While it is unclear if these changes lead to long-term symptoms or nerve injury, their existence adds to the evidence of a possible link between carpal tunnel syndrome and keyboarding. Published by Elsevier Ltd.

  17. Intradermal therapy (mesotherapy) for the treatment of acute pain in carpal tunnel syndrome: a preliminary study.

    Science.gov (United States)

    Conforti, Giorgio; Capone, Loredana; Corra, Stefano

    2014-01-01

    The carpal tunnel syndrome (CTS) is the most common cause of severe hand pain. In this study we treated acute pain in CTS patients by means of local intradermal injections of anti-inflammatory drugs (mesotherapy). In twenty-five patients (forty-five hands), CTS diagnosis was confirmed by clinical and neurophysiological examination prior to mesotherapy. A mixture containing lidocaine 10 mg, ketoprophen lysine-acetylsalycilate 80 mg, xantinol nicotinate 100 mg, cyanocobalamine 1,000 mcg plus injectable water was used. Sites of injection were three parallel lines above the transverse carpal ligament and two v-shaped lines, one at the base of the thenar eminence, and the other at the base of the hypothenar eminence. The day after the treatment, all but four patients reported a significant reduction in pain and paresthesias. After 12 months, 17 patients had a complete pain relief, eight patients reported recurrence of pain and sensory symptoms and four out of them underwent surgical treatment. With the obvious limits of a small-size open-label study, our results suggest that mesotherapy can temporary relieve pain and paresthesias in most CTS patients and in some cases its effect seems to be long-lasting. Further controlled studies are needed to confirm our preliminary findings and to compare mesotherapy to conventional approaches for the treatment of CTS.

  18. A case report of acute cubital tunnel syndrome caused by venous thrombosis.

    Science.gov (United States)

    Abe, Yoshihiro; Saito, Masahiko

    2015-01-01

    Compression neuropathy of the ulnar nerve at the elbow is well-recognised as cubital tunnel syndrome (CuTS). Many causes of ulnar neuropathy at the elbow have been identified. A previously unreported finding of ulnar nerve compression in the cubital tunnel caused by a thrombosed proximal ulnar recurrent artery vena comitans is described.

  19. Locking Compression Plate Fixation of Equine Tarsal Subluxations.

    Science.gov (United States)

    Keller, Sara A; Fürst, Anton E; Kircher, Patrick; Ringer, Simone; Kuemmerle, Jan M

    2015-11-01

    To report the clinical findings and outcome of locking compression plate (LCP) fixation of tarsal subluxations in horses. Retrospective case series. Horses (n = 3) and ponies (2). All horses and ponies diagnosed with tarsal subluxations and treated with LCP fixation at our institution between 2011 and 2013 were included. Data were collected from the medical records, including all radiographic and computed tomographic (CT) studies and reviewed. Long-term (>1 year) followup examination, including owner interview, and clinical and radiographic examinations were performed for all cases. Subluxations of the tarsometatarsal (n = 3) and proximal intertarsal (2) joints were diagnosed. CT examinations revealed complex joint injuries, including a combination of avulsion fragments and compression injuries at the opposite side of the joint from the subluxation. The LCP was applied to the plantarolateral or medial side of the limb. All horses survived and were discharged from the hospital. Short-term complications included mild laminitis (n = 1) and peroneus tertius rupture (2). At long-term followup, both ponies were sound and used as intended, whereas all horses showed mild to moderate lameness at the trot and were used for pleasure riding only. Radiographic signs of osteoarthritis developed in the joint affected by subluxation in all cases and in adjacent small tarsal joints in 2 horses and 1 pony. LCP fixation of tarsal subluxations resulted in stable fixation and allowed adequate healing. Subluxation of the small tarsal joints represents a complex injury and osteoarthritis commonly develops in the affected and adjacent joints. © Copyright 2015 by The American College of Veterinary Surgeons.

  20. Placing of tunneled central venous catheters prior to induction chemotherapy in children with acute lymphoblastic leukemia

    DEFF Research Database (Denmark)

    Handrup, Mette Møller; Møller, Jens Kjølseth; Frydenberg, Morten

    2010-01-01

    children hospitalized from January 2000 to March 2008 with newly diagnosed ALL and with double-lumen total implantable devices (TIDs) or tunneled external catheters (TEs) were included retrospectively. We only used data related to the patient's first catheter. RESULTS: We included 98 children; 35 received...

  1. Hardness map of human meta tarsals and phalanges of toes.

    Science.gov (United States)

    Manarvi, Irfan

    2016-08-01

    Predicting location of fracture in human bones has been a keen area of research for the past few decades. A variety of tests for hardness, deformation and strain field measurement have been conducted in the past; but considered insufficient due to various limitations. Researchers therefore have proposed further studies due to inaccuracies in measurement methods, testing machines and experimental errors. Advancement and availability of hardware, measuring instrumentation and testing machines can now provide remedies to these limitations. Human foot is a critical part of body exposed to various forces throughout its life. A number of products are developed for using over it for protection and care. Which many times do not provide sufficient protection and may itself become a source of stress due to non-consideration of the delicacy of bones in the feet. A continuous strain or overloading on feet may occur resulting to discomfort and even fracture. Not knowing how the hardness is spread all over the Meta tarsals and phalanges is one of major contributory factor for unsatisfactory design of foot protection products. This paper provides a complete hardness distribution map developed by experimental testing of all the Meta tarsals and Phalanges of toes for a typical human foot. The bones were taken from two left feet of a 40 and 42 year old male cadaver. These were dehydrated prior to measurements of hardness using Leeb hardness testing method. Hardness was measured around the circumference of a bone as well as along its length. Hardness values can be related to tensile strength of the bones to predict possible values of stress that could be borne by these bones. Results may also be used for design and developing various accessories for human feet health care and comfort.

  2. The ophthalmology surgical competency assessment rubric for lateral tarsal strip surgery.

    Science.gov (United States)

    Golnik, Karl C; Gauba, Vinod; Saleh, George M; Collin, Richard; Naik, Milind N; Devoto, Martin; Nerad, Jeffrey

    2012-01-01

    To produce an internationally valid tool to assess skill in performing lateral tarsal strip surgery. A panel of 7 content experts adapted a previously published tool for assessing lateral tarsal strip surgery by using a modified Dreyfus scale of skill acquisition and providing behavioral descriptors for each level of skill in each category. The tools were then reviewed by 11 international content experts for their constructive comments. Experts' comments were incorporated, establishing face and content validity. The tool International Council of Ophthalmology-Ophthalmology Surgical Competency Assessment Rubric for Lateral Tarsal Strip Surgery has face and content validity. It can be used globally to assess lateral tarsal strip surgical skill. Reliability and predictive validity still need to be determined.

  3. Predictive control of intersegmental tarsal movements in an insect.

    Science.gov (United States)

    Costalago-Meruelo, Alicia; Simpson, David M; Veres, Sandor M; Newland, Philip L

    2017-08-01

    In many animals intersegmental reflexes are important for postural and movement control but are still poorly undesrtood. Mathematical methods can be used to model the responses to stimulation, and thus go beyond a simple description of responses to specific inputs. Here we analyse an intersegmental reflex of the foot (tarsus) of the locust hind leg, which raises the tarsus when the tibia is flexed and depresses it when the tibia is extended. A novel method is described to measure and quantify the intersegmental responses of the tarsus to a stimulus to the femoro-tibial chordotonal organ. An Artificial Neural Network, the Time Delay Neural Network, was applied to understand the properties and dynamics of the reflex responses. The aim of this study was twofold: first to develop an accurate method to record and analyse the movement of an appendage and second, to apply methods to model the responses using Artificial Neural Networks. The results show that Artificial Neural Networks provide accurate predictions of tarsal movement when trained with an average reflex response to Gaussian White Noise stimulation compared to linear models. Furthermore, the Artificial Neural Network model can predict the individual responses of each animal and responses to others inputs such as a sinusoid. A detailed understanding of such a reflex response could be included in the design of orthoses or functional electrical stimulation treatments to improve walking in patients with neurological disorders as well as the bio/inspired design of robots.

  4. The tarsal-metatarsal complex of caviomorph rodents: Anatomy and functional-adaptive analysis.

    Science.gov (United States)

    Candela, Adriana M; Muñoz, Nahuel A; García-Esponda, César M

    2017-06-01

    Caviomorph rodents represent a major adaptive radiation of Neotropical mammals. They occupy a variety of ecological niches, which is also reflected in their wide array of locomotor behaviors. It is expected that this radiation would be mirrored by an equivalent disparity of tarsal-metatarsal morphology. Here, the tarsal-metatarsal complex of Erethizontidae, Cuniculidae, Dasyproctidae, Caviidae, Chinchillidae, Octodontidae, Ctenomyidae, and Echimyidae was examined, in order to evaluate its anatomical variation and functional-adaptive relevance in relation to locomotor behaviors. A qualitative study in functional morphology and a geometric morphometric analysis were performed. We recognized two distinct tarsal-metatarsal patterns that represent the extremes of anatomical variation in the foot. The first, typically present in arboreal species, is characterized by features that facilitate movements at different levels of the tarsal-metatarsal complex. The second pattern, typically present in cursorial caviomorphs, has a set of features that act to stabilize the joints, improve the interlocking of the tarsal bones, and restrict movements to the parasagittal plane. The morphological disparity recognized in this study seems to result from specific locomotor adaptations to climb, dig, run, jump and swim, as well as phylogenetic effects within and among the groups studies. © 2017 Wiley Periodicals, Inc.

  5. Microscopic characteristics of the inferior tarsal muscle and its surroundings in Korean

    Directory of Open Access Journals (Sweden)

    Hee Bae Ahn

    2013-04-01

    Full Text Available AIM: To investigate the detailed microscopic anatomic structures of the lower eyelid in Korean cadavers.METHODS: Eight lower eyelids of 4 formalin-fixed Asian cadavers (4 males; age range, 48-69 years; mean age, 60.2 years were examined. Three perpendicular dissected sections with a 2mm thickness were obtained from each eyelid to investigate anatomic shapes, size and relationship with surrounding structures. One section was obtained from the midline and 2 the other sections were obtained from a 3mm apart from the lateral and medial tarsus margins.RESULTS:The inferior tarsal muscle fibers were not directly attached to the tarsus but were only linked to the tarsus with enclosed fibrous fascia. The inferior tarsal muscles connected loosely with the capsulopalpebral fascia anteriorly and the conjunctiva posteriorly. The inferior tarsal muscle runs horizontally to the tarsus according to the shape of muscle fibers. The capsulopalpebral fascia consisted of an anterior and posterior layer. The anterior layer reached the orbital septum and subcutaneous fat but the posterior layer forwarded into the tarsus. Lockwood''s ligament was separated from the inferior tarsal muscle and capsulopalpebral fascia or fused into the capsulopalpebral fascia.CONCLUSION: This study suggests that the inferior tarsal muscle which runs horizontally and doesn’t insert directly into the tarsus, plays an important role in the movement and localization of the lower eyelid.

  6. Perturbed meibomian gland and tarsal plate morphogenesis by excess TGFα in eyelid stroma.

    Science.gov (United States)

    Dong, Fei; Liu, Chia-Yang; Yuan, Yong; Zhang, Yujin; Li, Wei; Call, Mindy; Zhang, Liyun; Chen, Yongxiong; Liu, Zuguo; Kao, Winston W Y

    2015-10-15

    Transforming growth factor alpha (TGFα) belongs to the epidermal growth factor (EGF) family and is known to play an important role during eyelid morphogenesis. In this study, we showed that ectopic expression of TGFα in the stroma of Kera-rtTA/tet-O-TGFα bitransgenic mice results in precocious eye opening, abnormal morphogenesis of the meibomian gland, tendon and tarsal plate malformation and epithelium hyperplasia. TGFα did not change proliferation and differentiation of meibocytes, but promoted proliferation and inhibited differentiation of the tarsal plate tenocytes. These results suggest that proper formation of the tendon and tarsal plate in the mouse eyelid is required for normal morphogenesis of the meibomian gland. Copyright © 2015 Elsevier Inc. All rights reserved.

  7. Interaction of liquid epicuticular hydrocarbons and tarsal adhesive secretion in Leptinotarsa decemlineata Say (Coleoptera: Chrysomelidae).

    Science.gov (United States)

    Geiselhardt, Stefanie F; Lamm, Stefan; Gack, Claudia; Peschke, Klaus

    2010-05-01

    Species of various insect orders possess specialised tarsal adhesive structures covered by a thin liquid film, which is deposited in the form of footprints. This adhesive liquid has been suggested to be chemically and physiologically related to the epicuticular lipid layer, which naturally covers the body of insects and acts as the prime barrier to environmental stresses, such as desiccation. The functional efficiency of the layer, however, is jeopardised by partial melting that may occur at physiological temperatures. In this study, light microscopic images of elytral prints show that the epicuticular lipid layer of the Colorado potato beetle Leptinotarsa decemlineata actually is partially liquid and chemical investigations reveal the high similarity of the epicuticular hydrocarbon pattern and the tarsal liquid. By means of chemical manipulation of the surface hydrocarbon composition of live beetles, the substance exchange between their tarsal adhesive hairs and the body surface is monitored. Histological sections of L. decemlineata tarsi, furthermore, reveal glandular cells connected to individual adhesive setae and departing from these results, an idea of a general mechanism of tarsal secretion is developed and discussed in a functional-ecological context.

  8. The dimensions of the tarsal sinus and canal in different foot positions and its clinical implications

    NARCIS (Netherlands)

    Kleipool, R. P.; Blankevoort, L.; Ruijter, J. M.; Kerkhoffs, G. M. M. J.; Oostra, R. J.

    2017-01-01

    This study presents a reference for the dimensions of the tarsal sinus and canal in healthy adults in different foot positions to facilitate understanding of the kinematics of the subtalar joint, the effect of an implant, and other clinical issues. In a 3D CT stress test on 20 subjects, the right

  9. Acute effect of topical menthol on chronic pain in slaughterhouse workers with carpal tunnel syndrome: triple-blind, randomized placebo-controlled trial

    DEFF Research Database (Denmark)

    Sundstrup, Emil; Jakobsen, Markus Due; Brandt, Mikkel

    2014-01-01

    Topical menthol gels are classified "topical analgesics" and are claimed to relieve minor aches and pains of the musculoskeletal system. In this study we investigate the acute effect of topical menthol on carpal tunnel syndrome (CTS). We screened 645 slaughterhouse workers and recruited 10...... participants with CTS and chronic pain of the arm/hand who were randomly distributed into two groups to receive topical menthol (Biofreeze) or placebo (gel with a menthol scent) during the working day and 48 hours later the other treatment (crossover design). Participants rated arm/hand pain intensity during...... the last hour of work (scale 0-10) immediately before 1, 2, and 3 hours after application. Furthermore, global rating of change (GROC) in arm/hand pain was assessed 3 hours after application. Compared with placebo, pain intensity and GROC improved more following application of topical menthol (P = 0...

  10. Short tunnels.

    NARCIS (Netherlands)

    Schreuder, D.A.

    1965-01-01

    Before dealing with the question of lighting short tunnels, it is necessary define what is meant by a tunnel and when it should be called 'short'. Confined to motorized road traffic the following is the most apt definition of a tunnel: every form of roofing-over a road section, irrespective of it

  11. Reverse-Flow Lateral Tarsal Island Flap for Covering the Great Toe Donor Site of Wraparound Flap.

    Science.gov (United States)

    Jia, Yachao; Xu, Jia; Kang, Qinglin; Zhang, Changqing; Chai, Yimin

    2016-10-01

    Coverage of the great toe donor site of wraparound flap remains a challenge. This report presents the results of using an innervated pedicled reverse-flow lateral tarsal island flap for covering the great toe donor site of wraparound flap. Between 2005 and 2010, 11 reverse-flow lateral tarsal island flaps were used to cover the great toe donor site of wraparound flap in 11 patients. This pedicled flap designed on the lateral tarsal area of foot was based distally on the dorsalis pedis artery; the lateral dorsal pedal cutaneous nerve was incorporated into the reverse-flow lateral tarsal island flap and coapted with the first plantar digital nerve. The donor sites of reverse-flow lateral tarsal island flap were covered with inguinal full-thickness skin grafts. All flaps achieved primary healing except for two that suffered from mild venous insufficiency which was managed by conservative intervention. All skin grafts covering the donor site of reverse-flow lateral tarsal island flap healed uneventfully. The mean follow-up was 24 months (range, 18-48 months). The mean hallux metatarsophalangeal-interphalangeal scale score was 92 points (range, 85-97 points) at 6 months postoperatively. The static 2-point discrimination of the reverse-flow lateral tarsal island flap ranged from 6 to 14 mm (mean 10 mm). None of the patients were restricted in standing or walking during follow-up. The reverse-flow lateral tarsal island flap based distally on the dorsalis pedis artery has a constant pedicle that is sufficiently long. This innervated pedicle flap is a reliable option to cover the great toe donor site of wraparound flap with satisfactory functional and cosmetic results and acceptable donor site morbidity.

  12. Acute Effect of Topical Menthol on Chronic Pain in Slaughterhouse Workers with Carpal Tunnel Syndrome: Triple-Blind, Randomized Placebo-Controlled Trial

    Directory of Open Access Journals (Sweden)

    Emil Sundstrup

    2014-01-01

    Full Text Available Topical menthol gels are classified “topical analgesics” and are claimed to relieve minor aches and pains of the musculoskeletal system. In this study we investigate the acute effect of topical menthol on carpal tunnel syndrome (CTS. We screened 645 slaughterhouse workers and recruited 10 participants with CTS and chronic pain of the arm/hand who were randomly distributed into two groups to receive topical menthol (Biofreeze or placebo (gel with a menthol scent during the working day and 48 hours later the other treatment (crossover design. Participants rated arm/hand pain intensity during the last hour of work (scale 0–10 immediately before 1, 2, and 3 hours after application. Furthermore, global rating of change (GROC in arm/hand pain was assessed 3 hours after application. Compared with placebo, pain intensity and GROC improved more following application of topical menthol (P=0.026 and P=0.044, resp.. Pain intensity of the arm/hand decreased by −1.2 (CI 95%: −1.7 to −0.6 following topical menthol compared with placebo, corresponding to a moderate effect size of 0.63. In conclusion, topical menthol acutely reduces pain intensity during the working day in slaughterhouse workers with CTS and should be considered as an effective nonsystemic alternative to regular analgesics in the workplace management of chronic and neuropathic pain.

  13. Diagonal tarsal suture technique sine marginal sutures for closure of full-thickness eyelid defects.

    Science.gov (United States)

    Willey, Andrea; Caesar, Richard H

    2013-01-01

    Precise apposition of the tarsal plates and meticulous alignment of the eyelid margins are essential to ensure a seamless repair and avoid notching of the eyelid margin. The authors present a simple and reliable technique that firmly apposes and precisely aligns the eyelid margin in the x, y, and z axes, obviating the need for marginal sutures. A retrospective audit of electronic medical records was performed for all patients who underwent reconstructive procedures that included the repair of a full-thickness defect in the eyelid margin using the diagonal suture technique from 2003 to 2012. Of the 652 surgeries performed in the past 9 years, 9 incidences of notching occurred, all of which were associated with infections. The diagonal tarsal suture technique is a simple and effective method for the repair of full-thickness defects with a high degree of patient satisfaction.

  14. Nonrigid external fixation of the elbow, coxofemoral, and tarsal joints in dogs.

    Science.gov (United States)

    Schwartz, Zeev; Griffon, Dominique

    2008-12-01

    Nonrigid external fixation of a joint is designed to restrict abnormal joint movement and facilitate healing of traumatized ligaments and capsule tissue with minimizing the impact of immobilization on articular homeostasis and cartilage metabolism. Weight bearing and joint motion minimize muscle atrophy and loss of bone mineral and allow controlled loading of the ligaments, thereby improving their strength and functionality. This article describes simple, cost effective techniques for the percutaneous application of external fixators to the elbow, coxofemoral, and tarsal joint of dogs.

  15. Fetal development of ligaments around the tarsal bones with special reference to contribution of muscles.

    Science.gov (United States)

    Uchiyama, Eiichi; Kim, Ji Hyun; Abe, Hiroshi; Cho, Baik Hwan; Rodríguez-Vázquez, Jose Francisco; Murakami, Gen

    2014-04-01

    Through a histological examination of eight mid-term human fetuses (10-15 weeks) and seven late-stage fetuses (30-34 weeks), we attempted to determine how and when fetal ligaments around the tarsal bones form the regular arrangement seen in adults. Ligaments along the dorsal aspect of the tarsal bones developed early as an elongation of the perichondrium, in contrast to the late development of the plantar-sided ligaments. In contrast, a distal elongation of the tibialis posterior tendon was a limited plantar ligament in the early stage; finally, it extended from the navicular, ran obliquely to cross the dorsal side of the fibularis longus tendon, and inserted to the lateral cuneiform and fourth metatarsal. In the late stage, the adductor hallucis muscle origin provided multiple ligamentous structures along the cuneiforms and metatarsals. The tarsal sinus contained multiple fibrous bundles (possibly, the putative interosseous talocalcanean ligaments) that were derived from (1) insertion tendons of the extensor digitorus brevis muscle and (2) the fibrous sheath of the extensor digitorus longus tendon. The aponeurotic origin of the quadratus plantae muscle seemed to contribute to formation of the long plantar ligament. Therefore, tarsal ligaments appeared likely to develop from the long tendons, their fibrous sheaths and aponeuroses and intramuscular tendons of the proper foot muscles. Under in utero conditions with little or no stress from the plantar side of the foot, the muscle-associated connective tissue seems to play a crucial role in providing a regular arrangement of the ligaments in accordance with tensile stress from muscle contraction. Copyright © 2013 Wiley Periodicals, Inc.

  16. Cytologic analysis of synovial fluid in clinically normal tarsal joints of young camels (Camelus dromedarius).

    Science.gov (United States)

    Al-Rukibat, R K; Bani Ismail, Z A; Al-Zghoul, M B

    2006-09-01

    Camels are important in the racing industry and for milk, meat, and hair production in the Middle East. Evaluation of synovial fluid is an important part of the assessment of musculoskeletal injuries in this species. Information in the literature regarding synovial fluid in camels is limited. The objective of this study was to determine the protein and cellular composition of synovial fluid from the tarsal joints of clinically normal, young camels (Camelus dromedarius). Thirty clinically healthy, male camels, aged 9 to 12 months, were used in the study. Synovial fluid samples were collected from the right and left tarsal joints. Samples were processed within 60 minutes after collection. Total nucleated cell counts (TNCC) were assessed using a hemacytometer. Total protein concentration was determined using a refractometer. Forty-six samples were analyzed. The TNCC (mean +/- SD) was 175.8 +/- 136.7 cells/microL (range 50-678 cells/microL). Differential cell percentages were obtained for lymphocytes (58.2 +/- 21.55%, range 15-90%), monocyte/macrophages (38.3 +/- 20.8%, range 10-85%), and neutrophils (3.5 +/- 5.1%, range 0-15%). Protein concentration was 2.1 +/- 0.6 g/dL (range 1-3 g/dL). Significant differences were not observed in any parameters between right and left tarsal joints. Synovial fluid reference values were established and may be useful in the clinical investigation of joint disease in young camels.

  17. Sex estimation from the tarsal bones in a Portuguese sample: a machine learning approach.

    Science.gov (United States)

    Navega, David; Vicente, Ricardo; Vieira, Duarte N; Ross, Ann H; Cunha, Eugénia

    2015-05-01

    Sex estimation is extremely important in the analysis of human remains as many of the subsequent biological parameters are sex specific (e.g., age at death, stature, and ancestry). When dealing with incomplete or fragmented remains, metric analysis of the tarsal bones of the feet has proven valuable. In this study, the utility of 18 width, length, and height tarsal measurements were assessed for sex-related variation in a Portuguese sample. A total of 300 males and females from the Coimbra Identified Skeletal Collection were used to develop sex prediction models based on statistical and machine learning algorithm such as discriminant function analysis, logistic regression, classification trees, and artificial neural networks. All models were evaluated using 10-fold cross-validation and an independent test sample composed of 60 males and females from the Identified Skeletal Collection of the 21st Century. Results showed that tarsal bone sex-related variation can be easily captured with a high degree of repeatability. A simple tree-based multivariate algorithm involving measurements from the calcaneus, talus, first and third cuneiforms, and cuboid resulted in 88.3% correct sex estimation both on training and independent test sets. Traditional statistical classifiers such as the discriminant function analysis were outperformed by machine learning techniques. Results obtained show that machine learning algorithm are an important tool the forensic practitioners should consider when developing new standards for sex estimation.

  18. Comparative study of the fluid viscosity in tarsal hairy attachment systems of flies and beetles.

    Science.gov (United States)

    Peisker, Henrik; Heepe, Lars; Kovalev, Alexander E; Gorb, Stanislav N

    2014-10-06

    Wet adhesive systems of insects strongly rely for their function on the formation of capillary bridges with the substrate. Studies on the chemical composition and evaporation dynamics of tarsal secretions strongly suggest a difference in chemistry of secretion in beetles and flies, both possessing hairy attachment devices. This difference is assumed to influence the viscosity of the secretion. Here, we applied a microrheological technique, based on the immersion of nanometric beads in the collected tarsal footprints, to estimate secretion viscosity in a beetle (Coccinella septempunctata) and a fly (Calliphora vicina). Both species studied possess distinct differences in viscosity, the median of which was calculated as 21.8 and 10.9 mPa s, respectively. We further present an approximate theoretical model to calculate the contact formation time of spatula-like terminal contact elements using the viscosity data of the covering fluid. The estimated contact formation time is proportional to the tarsal secretion viscosity and to the square of the contact radius of the contact element. © 2014 The Author(s) Published by the Royal Society. All rights reserved.

  19. The Tarsal Bone Test: A Basic Test of Health Sciences Students' Knowledge of Lower Limb Anatomy

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    José Manuel Castillo-López

    2014-01-01

    Full Text Available Objectives. The aim of the present study was to design an easy-to-use tool, the tarsal bone test (TBT, to provide a snapshot of podiatry students’ basic anatomical knowledge of the bones of the lower limb. Methods. The study included 254 podiatry students from three different universities, 145 of them were first-year students and 109 were in their fourth and final years. The TBT was administered without prior notice to the participants and was to be completed in 5 minutes. Results. The results show that 97.2% of the subjects (n=247 correctly labelled all tarsal bones, while the other 2.8% (n=7 incorrectly labelled at least one bone, that was either the cuboid (7 times or the navicular (6 times. Although only one fourth-year student inaccurately identified one bone, no significant differences in the distribution of the correct and incorrect responses were found between first and fourth-year students. Conclusions. The TBT seems to be a straightforward and easy-to-apply instrument, and provides an objective view of the level of knowledge acquired at different stages of podiatry studies.

  20. Comparison of heparin to citrate as a catheter locking solution for non-tunneled central venous hemodialysis catheters in patients requiring renal replacement therapy for acute renal failure (VERROU-REA study): study protocol for a randomized controlled trial.

    Science.gov (United States)

    Bruyère, Rémi; Soudry-Faure, Agnès; Capellier, Gilles; Binquet, Christine; Nadji, Abdelouaid; Torner, Stephane; Blasco, Gilles; Yannaraki, Maria; Barbar, Saber Davide; Quenot, Jean-Pierre

    2014-11-19

    The incidence of acute kidney injury (AKI) is estimated at 10 to 20% in patients admitted to intensive care units (ICU) and often requires renal replacement therapy (RRT). ICU mortality in AKI patients can exceed 50%. Venous catheters are the preferred vascular access method for AKI patients requiring RRT, but carry a risk of catheter thrombosis or infection. Catheter lock solutions are commonly used to prevent such complications. Heparin and citrate locks are both widely used for tunneled, long-term catheters, but few studies have compared citrate versus heparin for patients with short-term, non-tunneled catheters. We aim to compare citrate 4% catheter lock solution versus heparin in terms of event-free survival of the first non-tunneled hemodialysis catheter inserted in ICU patients with AKI requiring RRT. Secondary objectives are the rate of fibrinolysis, incidence of catheter thrombosis and catheter-related infection per 1,000 catheter days, length of stay in ICU and in-hospital and 28-day mortality. The VERROU-REA study is a randomized, prospective, multicenter, double-blind, parallel-group, controlled superiority study carried out in the medical, surgical and nephrological ICUs of two large university hospitals in eastern France. A catheter lock solution composed of trisodium citrate at 4% will be compared to unfractionated heparin at a concentration of 5,000 IU/mL. All consecutive adult patients with AKI requiring extracorporeal RRT, and in whom a first non-tunneled catheter is to be inserted by the jugular or femoral approach, will be eligible. Catheters inserted by the subclavian approach, patients with acute liver failure, thrombopenia or contraindication to systemic anticoagulation will be excluded. Patients will be followed up daily in accordance with standard practices for RRT until death or discharge. Data is scarce regarding the use of non-tunneled catheters in the ICU setting in patients with AKI. This study will provide an evidence base for

  1. Tarsal Coalition

    Science.gov (United States)

    ... of the condition and the response to treatment: Oral medications. Nonsteroidal anti-inflammatory drugs (NSAIDs), such as ibuprofen, may be helpful in reducing the pain and inflammation. Physical therapy. Physical therapy may include ...

  2. Therapeutic Effect of 0.1% Tacrolimus Eye Drops in the Tarsal Form of Vernal Keratoconjunctivitis.

    Science.gov (United States)

    Wan, Qi; Tang, Jing; Han, Yu; Wang, Dan; Ye, Hongquan

    2017-08-12

    The purpose of this study was to evaluate the efficacy and safety of 0.1% tacrolimus eye drops in the tarsal form of vernal keratoconjunctivitis (VKC) and to survey the changes of dendritic cells at the palpebral conjunctiva in patients with VKC by in vivo confocal microscopy. A total of 17 patients (34 eyes) with the tarsal form of VKC were enrolled in this prospective, nonrandomized case series. They were treated with 0.1% tacrolimus eye drops twice daily after discontinuation of all other topical medications. Subjective ocular symptoms and objective ocular signs were scored on a 4-point scale by one ophthalmologist and the characteristics of the dendritic cells in each right eye at the palpebral conjunctiva were evaluated by in vivo confocal microscopy before treatment and at the 1st, 2th, 4th, and 8th weeks after treatment. After 1 week of treatment with 0.1% tacrolimus eye drops, the score for each symptom in all patients showed a significant (p < 0.001) improvement, and 13 patients (76%) experienced dramatic relief of symptoms. In addition, there was a significantly (p < 0.001) decreased clinical sign score (except for giant papillae) after 4 weeks, and a significant (p < 0.001) improvement in the score of giant papillae after 8 weeks of treatment. The characteristics of dendritic cells (including cell count, total area, average size, perimeter, and diameter) showed a significant (p < 0.05) decrease after 2 weeks of treatment. During the follow-up, no other topical medications were required and no significant changes in visual acuity were documented. No cataracts or elevation of intraocular pressures were detected. Only 5 patients (29%) had a tingling or burning sensation or discomfort. Tacrolimus 0.1% eye drops are an effective and safe treatment for the tarsal form of VKC, and can rapidly inhibit the activity of dendritic cells, improve symptoms, reduce papillary hyperplasia, and reverse damage at the palpebral conjunctiva. The side effects could affect the

  3. Diagnostic imaging of the equine tarsal region using radiography and ultrasonography. Part 1: the soft tissues.

    Science.gov (United States)

    Vanderperren, Katrien; Raes, Els; Hoegaerts, Michel; Saunders, Jimmy H

    2009-02-01

    The equine tarsus is the most commonly affected hindlimb region associated with lameness. Diagnostic imaging is routinely applied but because of its complexity, being composed of 10 multifaceted bones and different joints, multiple ligaments, tendons and bursae, imaging this region can be a challenge. This is the first part of a two-part review of the structures and disorders of the equine tarsus. It describes the principal disorders affecting the soft tissues of the tarsal region and addresses some of the technical aspects in taking radiographic, ultrasonographic and scintigraphic images of the different soft tissue lesions. Where applicable, comments on the diagnostic use of contrast radiography, arthroscopy and tenoscopy are made. In current clinical practice a combination of radiography and ultrasonography is still most frequently used to arrive at a diagnosis.

  4. External fixation to correct tarsal-metatarsal fracture in rock pigeon (Columba livia

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    Leandro Almeida Rui

    Full Text Available ABSTRACT Orthopedic conditions, such as bone fractures, are very common in avian medicine. External fixators have been considered the gold standard for birds, since they allow early movement of the limbs and minimal invasive surgery. Fractures in several bones have been successfully treated in pigeons. However, to the best of our knowledge, this case represents the first report of successful surgical repair of tarsal-metatarsal fracture in rock pigeon. External fixator was made with four 24G catheters, being inserted manually proximal and distal to the fracture and connected with polymerizable acrylic. Radiographic consolidation of fracture was observed 60 days post-surgery and anti-inflammatory and antibiotic protocols were successful on avoiding pain and infection during surgery and bone healing.

  5. Quantification of skin displacement near the carpal, tarsal and fetlock joints of the walking horse.

    Science.gov (United States)

    van Weeren, P R; van den Bogert, A J; Barneveld, A

    1988-05-01

    A technique enabling simultaneous visualisation of skin and underlying bony structures in the walking horse was used to quantify skin displacements on the lateral surface of carpal, tarsal and fetlock joints. The technique employed implanted light-emitting-diodes (LEDs) for marking the bone, and self adhesive spot labels for marking the overlying skin. Photographic recordings were made. Skin displacement was measured in six Dutch Warmblood horses. Mean total displacements and mean displacement per degree of change of joint angle were calculated. Displacements at the level of the fetlock joints appeared to be generally small (less than or equal to 2 mm), but displacements up to 2 cm were measured in the distal tibia. Displacements of this magnitude are of importance for the interpretation of results obtained by modern gait analysis techniques.

  6. Morphology and neurophysiology of tarsal vibration receptors in the water strider Aquarius paludum (Heteroptera: Gerridae).

    Science.gov (United States)

    Perez Goodwyn, Pablo; Katsumata-Wada, Ayako; Okada, Koutaroh

    2009-09-01

    Substrate vibratory information receptors are extensively studied in insects and spiders, however for water surface dwelling species little data is available. We studied the vibration receptive organs in tarsi of the water strider Aquarius paludum, using light, transmission and scanning electron microscopes, and recorded the neural activity of the organs in response to vibrational stimuli, which were afterwards analysed with a custom made spike sorting program. We found that the tarsal chordotonal organ has one set of three scoloparia: one in the tarsomere I and two in the tarsomere II, all of which consisted of a few scolopidia. The chordotonal organ clearly responded to vibratory stimulation. Furthermore, we found that a pair of large subapical emergent dorsal setae, which had been deemed mechanosensory by previous authors, are not so. In turn, four ventral subapical trichobothria that are in direct contact with the water surface during locomotion, proved to be mechanosensory. The anatomical and ultrastructural observations support these electro-physiological results.

  7. The effect of collection and extension on tarsal flexion and fetlock extension at trot.

    Science.gov (United States)

    Walker, V A; Walters, J M; Griffith, L; Murray, R C

    2013-03-01

    A recent epidemiological study indicated that various factors may be related to injury in dressage horses, but the mechanism by which these injuries occur has yet to be determined. The suspensory ligament (SL) is a frequent site of injury, and it is assumed that greatest strain is placed on this structure in collected trot; this has yet to be proved conclusively. The study aimed to investigate the effect of collected and extended trot on the hindlimb movement pattern. Four dressage horses were fitted with markers and inertial motion sensors (IMS). High-speed video was obtained for 2 strides on each rein in collected and extended trot on 3 different surfaces: waxed outdoor; sand/plastic granules; and waxed indoor. Maximal tarsal flexion during stance and distal metatarsal coronary band ratio (MTCR), representing fetlock extension, were determined. Inertial motion sensor data determined stride duration, speed and stride length. Data were compared between collection and extension within horses on each surface, and compared between surfaces. Collected trot had significantly lower speed and stride length but longer stride duration than extended trot on all surfaces. All horses had less tarsal flexion and fetlock extension in collected compared with extended trot (P<0.05), which is likely to increase SL loading. The study findings indicate that extended trot may increase SL strain, providing a possible explanation for the high incidence of SL injury in horses trained for extravagant movement. It is possible that substantial use of extended trot could be a risk factor for development of suspensory desmitis, which might be one contributory factor in the prevalence of suspensory desmitis in young horses repeatedly undertaking extravagant movement. © 2012 EVJ Ltd.

  8. Slab fractures of the third tarsal bone: Minimally invasive repair using a single 3.5 mm cortex screw placed in lag fashion in 17 Thoroughbred racehorses.

    Science.gov (United States)

    Barker, W H J; Wright, I M

    2017-03-01

    A technique for minimally invasive repair of slab fractures of the third tarsal bone has not previously been reported. Results of third tarsal bone slab fracture repair in Thoroughbred racehorses are lacking. To report the outcomes of repair of uniplanar frontal slab factures of the third tarsal bone using a single 3.5 mm cortex screw in lag fashion. Retrospective case series. Case records of horses that had undergone this procedure were reviewed. Seventeen horses underwent surgery. Eighteen percent of cases had wedge shaped third tarsal bones. A point midway between the long and lateral digital extensor tendons and centrodistal and tarsometatarsal joints created a suitable entry site for implants. The fracture location, configuration and curvature of the third tarsal bone and associated joints requires a dorsolateral proximal-plantaromedial distal trajectory for the screw, which was determined by preplaced needles. There were no complications and fractures healed in all cases at 4-6 months post surgery. Seventy-nine percent of horses returned to racing and, at the time of reporting, 3 are in post operative rehabilitation programmes. The technique reported provides a safe, appropriate and repeatable means of repairing slab fractures of the third tarsal bone. Surgical repair is a viable alternative to conservative management. © 2016 EVJ Ltd.

  9. Carpal Tunnel Syndrome

    Science.gov (United States)

    ... a passing cramp? It could be carpal tunnel syndrome. The carpal tunnel is a narrow passageway of ... three times more likely to have carpal tunnel syndrome than men. Early diagnosis and treatment are important ...

  10. Tarsal platform show after upper eyelid blepharoplasty with or without brassiere sutures

    Directory of Open Access Journals (Sweden)

    Marisa Novaes de Figueiredo

    Full Text Available ABSTRACT Purpose: Increased tarsal platform show (TPS and decreased brow fat span (BFS are associated with favorable results in women undergoing cosmetic blepharoplasty. We conducted a study to evaluate the efficacy of upper blepharoplasty with or without a technique (brassiere sutures to increase TPS and decrease BFS. Methods: This is a prospective, randomized, comparative, case series study of 100 eyelids (50 consecutive women patients treated with cosmetic upper blepharoplasty performed by a single surgeon. Patients were randomized to receive traditional upper blepharoplasty with a single running suture skin closure versus orbicularis oculi muscle fixation to the periosteum (brassiere sutures prior to skin closure. Data on patient age, duration of follow-up, complications, and treatment were analyzed. The mean TPS, mean BFS, and mean TPS/BFS ratio were measured at three anatomic landmarks before and after surgery. Results: Fifty-six eyelids (28 patients were treated with traditional single suture blepharoplasty, and 44 eyelids (22 patients had brassiere sutures. In both groups, paired t-tests indicate significant differences between preoperative and postoperative evaluations (p0.05. Conclusions: Brassiere sutures during upper blepharoplasty and traditional blepharoplasty were associated with postoperative increase in TPS, decrease in BFS, and increase in TPS/BFS, without statistically significant differences between these surgeries.

  11. 3D kinematics of the tarsal joints from magnetic resonance images

    Science.gov (United States)

    Hirsch, Bruce E.; Udupa, Jayaram K.; Okereke, Enyi; Hillstrom, Howard J.; Siegler, Sorin; Ringleb, Stacie I.; Imhauser, Carl W.

    2001-09-01

    We have developed a method for analyzing motion at skeletal joints based on the 3D reconstruction of magnetic resonance (MR) image data. Since the information about each voxel in MR images includes its location in the scanner, it follows that information is available for each organ whose 3D surface is computed from a series of MR slices. In addition, there is information on the shape and orientation of each organ, and the contact areas of adjacent bones. By collecting image data in different positions we can calculate the motion of the individual bones. We have used this method to study human foot bones, in order to understand normal and abnormal foot function. It has been used to evaluate patients with tarsal coalitions, various forms of pes planus, ankle sprains, and several other conditions. A newly described feature of this system is the ability to visualize the contact area at a joint, as determined by the region of minimum distance. The display of contact area helps understand abnormal joint function. Also, the use of 3D imaging reveals motions in joints which cannot otherwise be visualized, such as the subtalar joint, for more accurate diagnosis of joint injury.

  12. Decaleside: a new class of natural insecticide targeting tarsal gustatory sites

    Science.gov (United States)

    Rajashekar, Yallappa; Rao, Lingamallu J. M.; Shivanandappa, Thimmappa

    2012-10-01

    Natural sources for novel insecticide molecules hold promise in view of their eco-friendly nature, selectivity, and mammalian safety. Recent progress in understanding the biology of insect olfaction and taste offers new strategies for developing selective pest control agents. We have isolated two natural insecticidal molecules from edible roots of Decalepis hamiltonii named Decalesides I and II, which are novel trisaccharides, highly toxic to household insect pests and stored-product insects. We have experimentally shown that insecticidal activity requires contact with tarsi on the legs but is not toxic orally. The insecticidal activity of molecules is lost by hydrolysis, and various sugars modify toxic response, showing that the insecticidal activity is via gustatory sites on the tarsi. Selective toxicity to insects by virtue of their gustatory site of action and the mammalian safety of the new insecticides is inherent in their chemical structure with 1-4 or 1-1 α linkage that is easily hydrolyzed by digestive enzymes of mammals. Decalesides represent a new chemical class of natural insecticides with a unique mode of action targeting tarsal chemosensory/gustatory system of insects.

  13. Evaluation of tarsal navicular stress fracture fixation using intraoperative O-arm computed tomography.

    Science.gov (United States)

    Hsu, Andrew R; Lee, Simon

    2014-12-01

    Stress fractures of the tarsal navicular are high-risk injuries that can result in displacement, avascular necrosis, malunion, and nonunion. Delayed diagnosis and improper treatment can lead to long-term functional impairments and poor clinical outcomes. Increased shear stress and decreased vascularity in the central third of the navicular can complicate bony healing with often unpredictable return times to activity using conservative management in a non-weight-bearing cast. There recently has been increasing debate regarding the effectiveness of treatment options with a trend toward surgical management to anatomically reduce and stabilize navicular stress fractures in athletes. However, anatomic reduction and fixation of the navicular can be difficult despite direct visualization and intraoperative fluoroscopy. We report a case of a chronic navicular stress fracture in a high-level teenage athlete treated with open reduction internal fixation (ORIF) and calcaneus autograft using intraoperative computed tomography (CT) (O-arm®, Medtronic, Minneapolis, MN) for real-time evaluation of fracture reduction and fixation. Intraoperative CT was fast, reliable, and allowed for confirmation of guide wire orientation, alignment, and length across the fracture site. Anatomic fixation of navicular stress fractures can be challenging, and it is important for surgeons to be aware of the potential advantages of using intraoperative CT when treating these injuries. Therapeutic, Level IV: Case Report. © 2014 The Author(s).

  14. Oldest known euarchontan tarsals and affinities of Paleocene Purgatorius to Primates.

    Science.gov (United States)

    Chester, Stephen G B; Bloch, Jonathan I; Boyer, Doug M; Clemens, William A

    2015-02-03

    Earliest Paleocene Purgatorius often is regarded as the geologically oldest primate, but it has been known only from fossilized dentitions since it was first described half a century ago. The dentition of Purgatorius is more primitive than those of all known living and fossil primates, leading some researchers to suggest that it lies near the ancestry of all other primates; however, others have questioned its affinities to primates or even to placental mammals. Here we report the first (to our knowledge) nondental remains (tarsal bones) attributed to Purgatorius from the same earliest Paleocene deposits that have yielded numerous fossil dentitions of this poorly known mammal. Three independent phylogenetic analyses that incorporate new data from these fossils support primate affinities of Purgatorius among euarchontan mammals (primates, treeshrews, and colugos). Astragali and calcanei attributed to Purgatorius indicate a mobile ankle typical of arboreal euarchontan mammals generally and of Paleocene and Eocene plesiadapiforms specifically and provide the earliest fossil evidence of arboreality in primates and other euarchontan mammals. Postcranial specializations for arboreality in the earliest primates likely played a key role in the evolutionary success of this mammalian radiation in the Paleocene.

  15. Central tarsal bone fractures in horses not used for racing: Computed tomographic configuration and long-term outcome of lag screw fixation.

    Science.gov (United States)

    Gunst, S; Del Chicca, F; Fürst, A E; Kuemmerle, J M

    2016-09-01

    There are no reports on the configuration of equine central tarsal bone fractures based on cross-sectional imaging and clinical and radiographic long-term outcome after internal fixation. To report clinical, radiographic and computed tomographic findings of equine central tarsal bone fractures and to evaluate the long-term outcome of internal fixation. Retrospective case series. All horses diagnosed with a central tarsal bone fracture at our institution in 2009-2013 were included. Computed tomography and internal fixation using lag screw technique was performed in all patients. Medical records and diagnostic images were reviewed retrospectively. A clinical and radiographic follow-up examination was performed at least 1 year post operatively. A central tarsal bone fracture was diagnosed in 6 horses. Five were Warmbloods used for showjumping and one was a Quarter Horse used for reining. All horses had sagittal slab fractures that began dorsally, ran in a plantar or plantaromedial direction and exited the plantar cortex at the plantar or plantaromedial indentation of the central tarsal bone. Marked sclerosis of the central tarsal bone was diagnosed in all patients. At long-term follow-up, 5/6 horses were sound and used as intended although mild osteophyte formation at the distal intertarsal joint was commonly observed. Central tarsal bone fractures in nonracehorses had a distinct configuration but radiographically subtle additional fracture lines can occur. A chronic stress related aetiology seems likely. Internal fixation of these fractures based on an accurate diagnosis of the individual fracture configuration resulted in a very good prognosis. © 2015 EVJ Ltd.

  16. DINÁMICAS COMPLEJAS EN EL DESARROLLO DEL PRIMER SEGMENTO TARSAL DE Drosophila melanogaster

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    Juan Nicolás MALAGON

    2016-01-01

    Full Text Available La interacción de grupos de genes, proteínas, y células es necesaria para el desarrollo de un organismo multicelular. Por tal motivo, la teoría de la complejidad puede ser una herramienta indispensable para entender cómo diversos procesos embriológicos y evolutivos suceden. Sin embargo, en la mayoría de los programas de investigación estas áreas permanecen aisladas. En un esfuerzo por crear un punto de integración entre el Evo-Devo y las ciencias de la complejidad, en este documento propongo que las dinámicas celulares de epitelios pueden tener comportamientos que se asemejan a los encontrados en sistemas complejos. Dichas dinámicas celulares, además de regular la densidad celular de los epitelios, pueden conferir alta evolucionabilidad a estos tejidos. Para lograr este objetivo, utilizo como sistema el desarrollo del primer segmento tarsal de las patas anteriores de Drosophila melanogaster. Primero doy un ejemplo en el cual dinámicas aleatorias a nivel celular pueden generar la emergencia de patrones organizados a nivel del tejido. En seguida muestro como la modificación de características morfológicas del epitelio puede generar dinámicas celulares altamente organizadas o por el contrario aleatorios. Como resultado, planteó que el desarrollo de los epitelios muestra rasgos de comportamientos complejos y propone que la retro-alimentación entre tensión mecánica y procesos celulares son básicos para entender cómo se desarrollan y evolucionan los organismos multicelulares. Estos estudios ponen en evidencia las bases mecánicas de procesos complejos que conectan diversos niveles de organización.

  17. Dinámicas complejas en el desarrollo del primer segmento tarsal de Drosophila melanogaster.

    Directory of Open Access Journals (Sweden)

    Juan Nicolas Malagon

    2016-09-01

    Full Text Available La interacción de grupos de genes, proteínas, y células es necesaria para el desarrollo de un organismo multicelular. Por tal motivo, la teoría de la complejidad puede ser una herramienta indispensable para entender cómo diversos procesos embriológicos y evolutivos suceden. Sin embargo, en la mayoría de los programas de investigación estas áreas permanecen aisladas. En un esfuerzo por crear un punto de integración entre el Evo-Devo y las ciencias de la complejidad, en este documento propongo que las dinámicas celulares de epitelios pueden tener comportamientos que se asemejan a los encontrados en sistemas complejos. Dichas dinámicas celulares, además de regular la densidad celular de los epitelios, pueden conferir alta evolucionabilidad a estos tejidos. Para lograr este objetivo, utilizo como sistema el desarrollo del primer segmento tarsal de las patas anteriores de Drosophila melanogaster. Primero doy un ejemplo en el cual dinámicas aleatorias a nivel celular pueden generar la emergencia de patrones organizados a nivel del tejido. En seguida muestro como la modificación de características morfológicas del epitelio puede generar dinámicas celulares altamente organizadas o por el contrario aleatorios. Como resultado, planteó que el desarrollo de los epitelios muestra rasgos de comportamientos complejos y propone que la retro-alimentación entre tensión mecánica y procesos celulares son básicos para entender cómo se desarrollan y evolucionan los organismos multicelulares. Estos estudios ponen en evidencia las bases mecánicas de procesos complejos que conectan diversos niveles de organización.

  18. Gestation length and racing performance in 115 Thoroughbred foals with incomplete tarsal ossification.

    Science.gov (United States)

    Haywood, L; Spike-Pierce, D L; Barr, B; Mathys, D; Mollenkopf, D

    2018-01-01

    Incomplete ossification of the cuboidal bones of the carpus and tarsus in foals has the potential for significant consequences including chronic lameness and decreased athletic ability. To determine if the degree of ossification of the cuboidal bones is associated with gestational length and if the diagnosis of incomplete ossification is a predictor of performance in Thoroughbred racehorses. Retrospective cohort study. The medical records of Thoroughbred foals less than 90 days of age from 1994 to 2011 were examined and records containing tarsal radiographs identified. Radiographs of the tarsus were examined for signs of incomplete ossification and those that were incompletely ossified graded on a scale of 1-4 using a modification of a previously reported index, with Grade 1 being the least ossified and Grade 4 being the most. Gestational length was determined by examining breeding records and foaling dates reported to the Jockey Club. Race records for 2- and 3-year-old affected foals and their maternal siblings were obtained and compared. Foals with Grades 1 and 2 ossification were usually premature (gestation length ossification were significantly less likely to race than their maternal siblings and Grades 1, 2, 3 and 4 foals earned less money. A larger sample size of foals with Grade 1 ossification would increase the power of the study. Foals radiographed at an older age may have had lower ossification scores if radiographed earlier. Incomplete ossification, especially Grades 1 and 2, is associated with a short gestation length. Foals with Grades 2 and 3 incomplete ossification were less likely to race and Grades 1, 2 and 3 earned around $30,000 less than their maternal siblings. © 2017 EVJ Ltd.

  19. Three-dimensional analysis of tarsal bone response to axial loading in patients with hallux valgus and normal feet.

    Science.gov (United States)

    Watanabe, Kota; Ikeda, Yasutoshi; Suzuki, Daisuke; Teramoto, Atsushi; Kobayashi, Takuma; Suzuki, Tomoyuki; Yamashita, Toshihiko

    2017-02-01

    Patients with hallux valgus present a variety of symptoms that may be related to the type of deformity. Weightbearing affects the deformities, and the evaluation of the load response of tarsal bones has been mainly performed using two-dimensional plane radiography. The purpose of this study was to investigate and compare structural changes in the medial foot arch between patients with hallux valgus and normal controls using a computer image analysis technique and weightbearing computed tomography data. Eleven patients with hallux valgus and eleven normal controls were included. Computed tomograms were obtained with and without simulated weightbearing using a compression device. Computed tomography data were transferred into a personal computer, and a three-dimensional bone model was created using image analysis software. The load responses of each tarsal bone in the medial foot arch were measured three-dimensionally and statistically compared between the two groups. Displacement of each tarsal bone under two weightbearing conditions was visually observed by creating three-dimensional bone models. At the first metatarsophalangeal joint, the proximal phalanges of the hallux valgus group showed significantly different displacements in multiple directions. Moreover, opposite responses to axial loading were also observed in both translation and rotation between the two groups. Weightbearing caused deterioration of the hallux valgus deformity three-dimensionally at the first metatarsophalangeal joint. Information from the computer image analysis was useful for understanding details of the pathology of foot disorders related to the deformities or instability and may contribute to the development of effective conservative and surgical treatments. Copyright © 2017 Elsevier Ltd. All rights reserved.

  20. Efficacy of immobilization of the tarsal joint to alleviate strain on the common calcaneal tendon in dogs.

    Science.gov (United States)

    Lister, Stephanie A; Renberg, Walter C; Roush, James K

    2009-01-01

    To measure strain in the common calcaneal tendon during trotting in dogs and to compare strain before and after immobilization of the tarsal joint. 6 dogs. A microminiature strain gauge was surgically implanted on the tendinous portion of the gastrocnemius muscle. Surface electromyography (EMG) values, percentage strain, and ground reaction forces were measured before and after immobilization. Peak vertical force; vertical impulse; initial, maximum, and final strain; and peak-to-peak EMG amplitude were recorded. Data were analyzed by use of a repeated-measures ANOVA and paired t tests. Timing of strain data correlated closely with foot strike of the hind limb and EMG activity in all dogs. Maximum tendon strain was simultaneous with peak vertical force. Continued muscle contraction was evident after immobilization. There was no significant difference in maximum strain after immobilization, compared with maximum strain during normal motion. Minimum strain, both at the beginning and end of the strain curve, was significantly decreased for the immobilized state, compared with results for nonimmobilized joints. Immobilization of the tarsal joint did not eliminate calcaneal tendon strain during weight bearing in dogs. Decreased isometric muscle contraction during the swing phase of the gait could account for smaller minimum strain in immobilized joints. Immobilization is frequently applied after Achilles tendon rupture to alleviate strain and force on the sutured repair, with possible complications because of the immobilization method. Consideration of these findings could be important in adjusting current treatment recommendations.

  1. Carpal tunnel biopsy

    Science.gov (United States)

    ... tunnel Images Carpal tunnel syndrome Surface anatomy - normal palm Surface anatomy - normal wrist Carpal biopsy References Calandruccio ... CA. Also reviewed by David Zieve, MD, MHA, Isla Ogilvie, PhD, and the A.D.A.M. ...

  2. Transonic Dynamics Tunnel (TDT)

    Data.gov (United States)

    Federal Laboratory Consortium — The Transonic Dynamics Tunnel (TDT) is a continuous flow wind-tunnel facility capable of speeds up to Mach 1.2 at stagnation pressures up to one atmosphere. The TDT...

  3. Hypersonic Tunnel Facility (HTF)

    Data.gov (United States)

    Federal Laboratory Consortium — The Hypersonic Tunnel Facility (HTF) is a blow-down, non-vitiated (clean air) free-jet wind tunnel capable of testing large-scale, propulsion systems at Mach 5, 6,...

  4. Carpal tunnel repair - slideshow

    Science.gov (United States)

    ... page: //medlineplus.gov/ency/presentations/100078.htm Carpal tunnel repair - series—Normal anatomy To use the sharing ... in the wrist and the wrist bones (carpal tunnel). Review Date 4/18/2017 Updated by: C. ...

  5. Road and Railroad Tunnels

    Data.gov (United States)

    Department of Homeland Security — Tunnels in the United States According to the HSIP Tiger Team Report, a tunnel is defined as a linear underground passageway open at both ends. This dataset is based...

  6. Quantum theory of tunneling

    CERN Document Server

    Razavy, Mohsen

    2014-01-01

    In this revised and expanded edition, in addition to a comprehensible introduction to the theoretical foundations of quantum tunneling based on different methods of formulating and solving tunneling problems, different semiclassical approximations for multidimensional systems are presented. Particular attention is given to the tunneling of composite systems, with examples taken from molecular tunneling and also from nuclear reactions. The interesting and puzzling features of tunneling times are given extensive coverage, and the possibility of measurement of these times with quantum clocks are critically examined. In addition by considering the analogy between evanescent waves in waveguides and in quantum tunneling, the times related to electromagnetic wave propagation have been used to explain certain aspects of quantum tunneling times. These topics are treated in both non-relativistic as well as relativistic regimes. Finally, a large number of examples of tunneling in atomic, molecular, condensed matter and ...

  7. Tunnel and Station Cost Methodology : Mined Tunnels

    Science.gov (United States)

    1983-01-01

    The main objective of this study was to develop a model for estimating the cost of subway station and tunnel construction. This report describes a cost estimating methodology for subway tunnels that can be used by planners, designers, owners, and gov...

  8. Reconstruction of large upper eyelid defects with a free tarsal plate graft and a myocutaneous pedicle flap plus a free skin graft

    DEFF Research Database (Denmark)

    Toft, Peter B

    2016-01-01

    PURPOSE: To review and present the results of a one-step method employing a free tarsal plate graft and a myocutaneous pedicle flap plus a free skin graft for reconstruction of large upper eyelid defects after tumour surgery. METHODS: This was a retrospective case-series of 8 patients who underwe...

  9. Proton tunneling in solids

    Energy Technology Data Exchange (ETDEWEB)

    Kondo, J.

    1998-10-01

    The tunneling rate of the proton and its isotopes between interstitial sites in solids is studied theoretically. The phonons and/or the electrons in the solid have two effects on the tunneling phenomenon. First, they suppress the transfer integral between two neighbouring states. Second, they give rise to a finite lifetime of the proton state. Usually the second effect is large and the tunneling probability per unit time (tunneling rate) can be defined. In some cases, however, a coherent tunneling is expected and actually observed. (author)

  10. Bone volume and regional density of the central tarsal bone detected using computed tomography in a cross-sectional study of adult racing greyhounds.

    Science.gov (United States)

    Thompson, D J; Cave, N J; Bridges, J P; Reuvers, K; Owen, M C; Firth, E C

    2012-09-01

    To determine whether left-to-right asymmetry of the central tarsal bone (CTB) of racing greyhounds was detectable using computed tomography (CT) in live dogs; to quantify the asymmetry in terms of average bone volume, volumetric bone mineral density (vBMD), and dorsal cortical shape, and to determine if age, gender, bodyweight, number of starts or history of tarsal injury were significant covariates. One trainer supplied 11 male and seven female, unrelated, skeletally mature, actively racing greyhounds, including dogs with a history of tarsal injury diagnosed by the trainer and/or track veterinarian (n=8), and dogs without a history of tarsal injury (n=10). Using CT, standardised parameters of the CTB were measured including volume and average vBMD of the left and right CTB, vBMD of regions within the CTB, and bone shape. There was no difference in the volumes of the left and right CTB and no association with number of racing starts. Volume of CTB in dogs with a history of tarsal injury was greater than in dogs with no history of injury (pracing greyhounds was detected using CT. Contrary to previous suggestions, the asymmetry was not associated with the number of racing starts. We propose that the majority of the adaptive modelling of the CTB occurred rapidly following the onset of counter-clockwise training, with little further modelling throughout the racing career of the dog, however further investigation is warranted. This study described a technique using CT for imaging the CTB in live dogs, which opens the way for a longitudinal study of bone modelling of the CTB in response to training and racing in a counter-clockwise direction.

  11. Osteochondral lesions in distal tarsal joints of Icelandic horses reveal strong associations between hyaline and calcified cartilage abnormalities.

    Science.gov (United States)

    Ley, C J; Ekman, S; Hansson, K; Björnsdóttir, S; Boyde, A

    2014-03-25

    Osteochondral lesions in the joints of the distal tarsal region of young Icelandic horses provide a natural model for the early stages of osteoarthritis (OA) in low-motion joints. We describe and characterise mineralised and non-mineralised osteochondral lesions in left distal tarsal region joint specimens from twenty-two 30 ±1 month-old Icelandic horses. Combinations of confocal scanning light microscopy, backscattered electron scanning electron microscopy (including, importantly, iodine staining) and three-dimensional microcomputed tomography were used on specimens obtained with guidance from clinical imaging. Lesion-types were described and classified into groups according to morphological features. Their locations in the hyaline articular cartilage (HAC), articular calcified cartilage (ACC), subchondral bone (SCB) and the joint margin tissues were identified and their frequency in the joints recorded. Associations and correlations between lesion-types were investigated for centrodistal joints only. In centrodistal joints the lesion-types HAC chondrocyte loss, HAC fibrillation, HAC central chondrocyte clusters, ACC arrest and ACC advance had significant associations and strong correlations. These lesion-types had moderate to high frequency in centrodistal joints but low frequencies in tarsometatarsal and talocalcaneal-centroquartal joints. Joint margin lesion-types had no significant associations with other lesion-types in the centrodistal joints but high frequency in both the centrodistal and tarsometatarsal joints. The frequency of SCB lesion-types in all joints was low. Hypermineralised infill phase lesion-types were detected. Our results emphasise close associations between HAC and ACC lesions in equine centrodistal joints and the importance of ACC lesions in the development of OA in low-motion compression-loaded equine joints.

  12. The Superluminal Tunneling Story

    OpenAIRE

    Aichmann, Horst; Nimtz, Günter

    2013-01-01

    Since 1992 experimental evidence of superluminal (faster than light, FTL) signals are causing much excitement in the physical community and in the media. Superluminal signal velocity and zero time tunneling was first observed in an analog tunneling experiment with microwaves. Recently, the conjectured zero time of electron was claimed to be observed in ionizing helium. The FTL signal velocity was reproduced with infrared light and with various tunneling barriers in several laboratories worldw...

  13. Microsystem Aeromechanics Wind Tunnel

    Data.gov (United States)

    Federal Laboratory Consortium — The Microsystem Aeromechanics Wind Tunnel advances the study of fundamental flow physics relevant to micro air vehicle (MAV) flight and assesses vehicle performance...

  14. Radio Wave Propagation in Tunnels

    National Research Council Canada - National Science Library

    Lee, Jeho

    2000-01-01

    This report examines the radio propagation model for narrow and long tunnels. Modal analysis is used to model the path gain in 2-D and 3-D rectangular tunnels and the coupling loss of L, T and cross tunnels...

  15. Carpal Tunnel Syndrome (For Kids)

    Science.gov (United States)

    ... OK for Kids? Your Teeth Heart Murmurs Carpal Tunnel Syndrome KidsHealth > For Kids > Carpal Tunnel Syndrome Print ... syndrome in the first place. Where Is This Tunnel? Take a look at the palm of your ...

  16. Tunnel operations study.

    Science.gov (United States)

    2013-12-01

    In June 2000, the State of Alaska Department of Transportation and Public Facilities completed construction of the Whittier Access Project by converting the existing 2.5- : mile Whittier Tunnel into the worlds only dual-use highway/rail tunnel wit...

  17. Tunnel fire dynamics

    CERN Document Server

    Ingason, Haukur; Lönnermark, Anders

    2015-01-01

    This book covers a wide range of issues in fire safety engineering in tunnels, describes the phenomena related to tunnel fire dynamics, presents state-of-the-art research, and gives detailed solutions to these major issues. Examples for calculations are provided. The aim is to significantly improve the understanding of fire safety engineering in tunnels. Chapters on fuel and ventilation control, combustion products, gas temperatures, heat fluxes, smoke stratification, visibility, tenability, design fire curves, heat release, fire suppression and detection, CFD modeling, and scaling techniques all equip readers to create their own fire safety plans for tunnels. This book should be purchased by any engineer or public official with responsibility for tunnels. It would also be of interest to many fire protection engineers as an application of evolving technical principles of fire safety.

  18. Short- and long-term racing performance of Standardbred pacers and trotters after early surgical intervention for tarsal osteochondrosis.

    Science.gov (United States)

    McCoy, A M; Ralston, S L; McCue, M E

    2015-07-01

    Osteochondrosis (OC) is commonly diagnosed in young Standardbred racehorses but its effect on performance when surgically treated at a young age is still incompletely understood. This is especially true for Standardbred pacers, which are underrepresented in the existing literature. To characterise the short- (2-year-old) and long-term (through 5-year-old) racing performance in Standardbred pacers and trotters after early surgical intervention (race records for each horse included starts, wins, finishes in the top 3 (win, place or show), earnings and fastest time. Comparisons between OC-affected and unaffected horses were made for the entire population and within gaits. A smaller related population (n = 94) had these performance measures evaluated for their 2-5-year-old racing seasons. Osteochondrosis status was associated with few performance measures. Trotters were at higher risk for lesions of the medial malleolus but lower risk for lesions of the distal intermediate ridge of the tibia than were pacers. Horses with bilateral OC lesions and lateral trochlear ridge (LTR) lesions started fewer races at 2 years of age than those with unilateral lesions or without LTR lesions. Osteochondrosis seemed to have minimal effect on racing performance in this cohort, although horses with bilateral and LTR lesions started fewer races at 2 years. There was evidence for different distribution of OC lesions among pacers and trotters, which should be explored further. Standardbreds undergoing early removal of tarsal OC lesions can be expected to perform equivalently to their unaffected counterparts. © 2014 EVJ Ltd.

  19. Reversible regulation of cell cycle-related genes by epigallocatechin gallate for hibernation of neonatal human tarsal fibroblasts.

    Science.gov (United States)

    Bae, Jung Yoon; Kanamune, Jun; Han, Dong-Wook; Matsumura, Kazuaki; Hyon, Suong-Hyu

    2009-01-01

    We investigated the hibernation effect of epigallocatechin-3-O-gallate (EGCG) on neonatal human tarsal fibroblasts (nHTFs) by analyzing the expression of cell cycle-related genes. EGCG application to culture media moderately inhibited the growth of nHTFs, and the removal of EGCG from culture media led to complete recovery of cell growth. EGCG resulted in a slight decrease in the cell population of the S and G(2)/M phases of cell cycle with concomitant increase in that of the G(0)/G(1) phase, but this cell cycle profile was restored to the initial level after EGCG removal. The expression of cyclin D1 (CCND1), CCNE2, CCN-dependent kinase 6 (CDK6), and CDK2 was restored, whereas that of CCNA, CCNB1, and CDK1 was irreversibly attenuated. The expression of a substantial number of genes analyzed by cDNA microarray was affected by EGCG application, and these affected expression levels were restored to the normal levels after EGCG removal. We also found the incorporation of FITC-EGCG into the cytosol of nHTFs and its further nuclear translocation, which might lead to the regulation of the exogenous signals directed to genes for cellular responses including proliferation and cell cycle progression. These results suggest that EGCG temporarily affects not only genes related to the cell cycle but also various other cellular functions.

  20. Carpal Tunnel Syndrome

    Science.gov (United States)

    ... make CTS better and help relieve symptoms. Massage, yoga, ultrasound, chiropractic manipulation, and acupuncture are just a ... tunnel syndrome > A-Z Health Topics Related information Menopause Pregnancy The javascript used in this widget is ...

  1. Carpal Tunnel Syndrome

    Science.gov (United States)

    ... is not confined to people in a single industry or job, but is especially common in those ... tunnel syndrome. Nonsteroidal anti-inflammatory drugs, such as aspirin, ibuprofen, and other nonprescription pain relievers, may provide ...

  2. INCAS TRISONIC WIND TUNNEL

    Directory of Open Access Journals (Sweden)

    Florin MUNTEANU

    2009-09-01

    Full Text Available The 1.2 m x 1.2 m Trisonic Blowdown Wind Tunnel is the largest of the experimental facilities at the National Institute for Aerospace Research - I.N.C.A.S. "Elie Carafoli", Bucharest, Romania. The tunnel has been designed by the Canadian company DSMA (now AIOLOS and since its commissioning in 1978 has performed high speed aerodynamic tests for more than 120 projects of aircraft, missiles and other objects among which the twin jet fighter IAR-93, the jet trainer IAR-99, the MIG-21 Lancer, the Polish jet fighter YRYDA and others. In the last years the wind tunnel has been used mostly for experimental research in European projects such as UFAST. The high flow quality parameters and the wide range of testing capabilities ensure the competitivity of the tunnel at an international level.

  3. Quantum tunneling with friction

    Science.gov (United States)

    Tokieda, M.; Hagino, K.

    2017-05-01

    Using the phenomenological quantum friction models introduced by P. Caldirola [Nuovo Cimento 18, 393 (1941), 10.1007/BF02960144] and E. Kanai [Prog. Theor. Phys. 3, 440 (1948), 10.1143/ptp/3.4.440], M. D. Kostin [J. Chem. Phys. 57, 3589 (1972), 10.1063/1.1678812], and K. Albrecht [Phys. Lett. B 56, 127 (1975), 10.1016/0370-2693(75)90283-X], we study quantum tunneling of a one-dimensional potential in the presence of energy dissipation. To this end, we calculate the tunneling probability using a time-dependent wave-packet method. The friction reduces the tunneling probability. We show that the three models provide similar penetrabilities to each other, among which the Caldirola-Kanai model requires the least numerical effort. We also discuss the effect of energy dissipation on quantum tunneling in terms of barrier distributions.

  4. Wind Tunnel Testing Facilities

    Data.gov (United States)

    Federal Laboratory Consortium — NASA Ames Research Center is pleased to offer the services of our premier wind tunnel facilities that have a broad range of proven testing capabilities to customers...

  5. Wind Tunnel Facility

    Data.gov (United States)

    Federal Laboratory Consortium — This ARDEC facility consists of subsonic, transonic, and supersonic wind tunnels to acquire aerodynamic data. Full-scale and sub-scale models of munitions are fitted...

  6. Steel formworks for tunnelling

    OpenAIRE

    Andrić, Ante; Tešović, Snježana

    2008-01-01

    The plant used for concreting the secondary tunnel lining is described. The plant is made of three segments: sheathing, self-propelled conveyor, and concrete supply system. In addition to technical properties and other features of this plant, the authors describe the work technology, and problems encountered during concept development, design and adjustment for three-rail and four-rail formwork. The structure of formwork portal, face formwork and tunnel lay-by is described and presented, incl...

  7. The Beginner's Guide to Wind Tunnels with TunnelSim and TunnelSys

    Science.gov (United States)

    Benson, Thomas J.; Galica, Carol A.; Vila, Anthony J.

    2010-01-01

    The Beginner's Guide to Wind Tunnels is a Web-based, on-line textbook that explains and demonstrates the history, physics, and mathematics involved with wind tunnels and wind tunnel testing. The Web site contains several interactive computer programs to demonstrate scientific principles. TunnelSim is an interactive, educational computer program that demonstrates basic wind tunnel design and operation. TunnelSim is a Java (Sun Microsystems Inc.) applet that solves the continuity and Bernoulli equations to determine the velocity and pressure throughout a tunnel design. TunnelSys is a group of Java applications that mimic wind tunnel testing techniques. Using TunnelSys, a team of students designs, tests, and post-processes the data for a virtual, low speed, and aircraft wing.

  8. Ultrastructure of chemoreceptive tarsal sensilla in an armored harvestman and evidence of olfaction across Laniatores (Arachnida, Opiliones).

    Science.gov (United States)

    Gainett, Guilherme; Michalik, Peter; Müller, Carsten H G; Giribet, Gonzalo; Talarico, Giovanni; Willemart, Rodrigo H

    2017-03-01

    Harvestmen (Arachnida, Opiliones) are especially dependent on chemical cues and are often regarded as animals that rely mainly on contact chemoreception. Information on harvestman sensilla is scarce when compared to other arachnid orders, especially concerning internal morphology. Using scanning (SEM) and transmission (TEM) electron microscopy, we investigated tarsal sensilla on the distal tarsomeres (DT) of all leg pairs in Heteromitobates discolor (Laniatores, Gonyleptidae). Furthermore, we explored the typological diversity of sensilla present on the DT I and II in members of the suborder Laniatores, which include two thirds of the formally described opilionid fauna, using species from 17 families representing all main laniatorian lineages. Our data revealed that DT I and II of H. discolor are equipped with wall-pored falciform hairs (two types), wall-pored sensilla chaetica (two types) and tip-pored sensilla chaetica, while DT III and IV are mainly covered with trichomes (non-sensory) and tip-pored sensilla chaetica. The ultrastructural characteristics support an olfactory function for all wall-pored sensilla and a dual gustatory/mechanoreceptive function for tip-pored sensilla chaetica. Based on our comparative SEM survey, we show that wall-pored sensilla occur in all investigated Laniatores, demonstrating their widespread occurrence in the suborder and highlighting the importance of both legs I and II as the sensory appendages of laniatorean harvestmen. Our results provide the first morphological evidence for olfactory receptors in Laniatores and suggest that olfaction is more important for harvestmen than previously thought. Copyright © 2016 Elsevier Ltd. All rights reserved.

  9. A randomized, controlled trial of the effects of resveratrol administration in performance horses with lameness localized to the distal tarsal joints.

    Science.gov (United States)

    Watts, Ashlee E; Dabareiner, Robin; Marsh, Chad; Carter, G Kent; Cummings, Kevin J

    2016-09-15

    OBJECTIVE To determine the effect of resveratrol administration in performance horses with lameness localized to the distal tarsal joints. DESIGN Randomized, blinded, placebo-controlled clinical trial. ANIMALS 45 client-owned horses with lameness localized to the distal tarsal joints. PROCEDURES All horses received injections of triamcinolone acetonide in the centrodistal and tarsometatarsal joints of both hind limbs. A placebo or a supplement containing resveratrol was fed twice daily by owners for 4 months. Primary outcomes were horse performance as determined by rider opinion (better, worse, or the same) and change in lameness severity from the enrollment examination. RESULTS Complete data were obtained for 21 horses that received resveratrol and 20 that received the placebo. Percentage of riders who reported that the horse's performance was better, compared with worse or the same, was significantly higher for the resveratrol group than for the placebo group after 2 (20/21 [95%] vs 14/20 [70%]) and 4 (18/21 [86%] vs 10/20 [50%]) months. The change in A1:A2 ratio between the enrollment and 4-month recheck examinations was significantly better for horses in the resveratrol versus placebo group. However, subjective lameness scores and degree of asymmetry of pelvis movement did not differ between groups. CONCLUSIONS AND CLINICAL RELEVANCE Results suggested that in performance horses with lameness localized to the distal tarsal joints, injection of triamcinolone in the centrodistal and tarsometatarsal joints of both hind limbs followed by oral supplementation with resveratrol for 4 months resulted in reduced lameness, compared with triamcinolone injection and supplementation with a placebo.

  10. Tunneling in axion monodromy

    Energy Technology Data Exchange (ETDEWEB)

    Brown, Jon; Cottrell, William; Shiu, Gary; Soler, Pablo [Department of Physics, University of Wisconsin,Madison, WI 53706 (United States)

    2016-10-06

    The Coleman formula for vacuum decay and bubble nucleation has been used to estimate the tunneling rate in models of axion monodromy in recent literature. However, several of Coleman’s original assumptions do not hold for such models. Here we derive a new estimate with this in mind using a similar Euclidean procedure. We find that there are significant regions of parameter space for which the tunneling rate in axion monodromy is not well approximated by the Coleman formula. However, there is also a regime relevant to large field inflation in which both estimates parametrically agree. We also briefly comment on the applications of our results to the relaxion scenario.

  11. LEP tunnel monorail

    CERN Multimedia

    1985-01-01

    A monorail from CERN's Large Electron Positron collider (LEP, for short). It ran around the 27km tunnel, transporting equipment and personnel. With its 27-kilometre circumference, LEP was the largest electron-positron accelerator ever built and ran from 1989 to 2000. During 11 years of research, LEP's experiments provided a detailed study of the electroweak interaction. Measurements performed at LEP also proved that there are three – and only three – generations of particles of matter. LEP was closed down on 2 November 2000 to make way for the construction of the Large Hadron Collider in the same tunnel.

  12. Breaking through the tranfer tunnel

    CERN Multimedia

    Laurent Guiraud

    2001-01-01

    This image shows the tunnel boring machine breaking through the transfer tunnel into the LHC tunnel. Proton beams will be transferred from the SPS pre-accelerator to the LHC at 450 GeV through two specially constructed transfer tunnels. From left to right: LHC Project Director, Lyn Evans; CERN Director-General (at the time), Luciano Maiani, and Director for Accelerators, Kurt Hubner.

  13. Zero-Time Tunneling - Revisited

    Science.gov (United States)

    Nimtz, Günter; Aichmann, Horst

    2017-08-01

    Since 1931, the nonclassical process of tunneling was conjectured to have a zero-time delay in the barrier. These theories have been rejected and denied. However, photonic and recent electronic tunneling experiments have proven the zero-time prediction. Tunneling is due to virtual wave packets in electromagnetic, elastic, and Schrödinger wave fields up to the macroscopic level. In this article we cite theoretical and experimental studies on zero-time tunneling, which have proven this striking behavior.

  14. Tunnelling with wormhole creation

    Energy Technology Data Exchange (ETDEWEB)

    Ansoldi, S. [National Institute of Nuclear Physics (INFN) (Italy); Tanaka, T., E-mail: tanaka@yukawa.kyoto-u.ac.jp [Kyoto University, Department of Physics (Japan)

    2015-03-15

    The description of quantum tunnelling in the presence of gravity shows subtleties in some cases. We discuss wormhole production in the context of the spherically symmetric thin-shell approximation. By presenting a fully consistent treatment based on canonical quantization, we solve a controversy present in the literature.

  15. Tunnelling Effects in Chemistry

    Indian Academy of Sciences (India)

    IAS Admin

    Tunnelling Effects in Chemistry. Molecules in the Strange Quantum World. Sharmistha Karmakar, Deepthi Jose and Ayan Datta. (left) Sharmistha Karmakar is doing her PhD in the group of. Ayan Datta, IACS,. Kolkata. Her research interests are modelling molecules with strong optical absorbtion and emission properties.

  16. Signatures of chaotic tunnelling

    OpenAIRE

    Mouchet, Amaury; Delande, Dominique

    2002-01-01

    Recent experiments with cold atoms provide a significant step toward a better understanding of tunnelling when irregular dynamics is present at the classical level. In this paper, we lay out numerical studies which shed light on the previous experiments, help to clarify the underlying physics and have the ambition to be guidelines for future experiments.

  17. INCAS SUBSONIC WIND TUNNEL

    Directory of Open Access Journals (Sweden)

    Corneliu STOICA

    2009-09-01

    Full Text Available The INCAS Subsonic Wind Tunnel is a closed circuit, continuous, atmospheric pressure facility with a maximum speed of 110 m/s. The test section is octagonal ,of 2.5 m wide, 2.0 m high and 4 m long. The tunnel is powered by a 1200 kW, air cooled variable speed DC motor which drives a 12 blade, 3.5 m diameter fan and is equipped with a six component pyramidal type external mechanical balance with a 700 Kgf maximum lift capacity.The angle of attack range is between -45º and +45º while the yaw angle range is between -140º and +216º .The data acquisition system has been modified recently to allow the recording of all test data on a PC - type computer using LABVIEW and a PXI – type chassis containing specialized data acquisition modules.The tunnel is equipped with a variable frequency electrical supply system for powered models and a 10 bar compressed air supply for pneumatic flow control applications.In the recent years the subsonic wind tunnel has been intensively used for tests within several European projects (AVERT, CESAR and others.

  18. Carpal tunnel release

    DEFF Research Database (Denmark)

    Larsen, Morten Bo; Sørensen, A I; Crone, K L

    2013-01-01

    A single-blind, randomized, controlled trial was done to compare the results of carpal tunnel release using classic incision, short incision, or endoscopic technique. In total, 90 consecutive cases were included. Follow-up was 24 weeks. We found a significantly shorter sick leave in the endoscopic...

  19. Tunnelling Effects in Chemistry

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 19; Issue 2. Tunnelling Effects in Chemistry: Molecules in the Strange Quantum World. Sharmistha Karmakar Deepthi Jose Ayan Datta. General Article Volume 19 Issue 2 February 2014 pp 160-174 ...

  20. Tarsal navicular stress injury: long-term outcome and clinicoradiological correlation using both computed tomography and magnetic resonance imaging.

    Science.gov (United States)

    Burne, Scott G; Mahoney, Chris M; Forster, Bruce B; Koehle, Michael S; Taunton, Jack E; Khan, Karim M

    2005-12-01

    Tarsal navicular stress fracture is a condition that has curtailed many athletic careers. Management protocols remain varied and somewhat controversial. (1) Clinical practice does not mirror the recommendations reported from previous case series. (2) Clinical outcome is poor when navicular stress fracture is managed in a variety of ways. (3) Imaging does not correlate strongly with clinical status at long-term follow-up after navicular stress fracture. Case series (prognosis); Level of evidence, 4. From a computer registry, we identified patients who had attended a university sports medicine center between 1996 and 2002 and whose final diagnosis was navicular stress fracture (n = 11) or navicular stress reaction (n = 9). All patients had provided demographic and clinical data at their original evaluation, and all had undergone bone scans and computed tomographic imaging. These data were extracted by chart review. Follow-up clinical and imaging assessments took place a median of 3.7 years later (range, 1-15.7 years). At these assessments, we administered a questionnaire, performed a structured physician examination (blinded to other data), scanned both feet with computed tomography, and obtained magnetic resonance images of the affected foot. Only 2 of 11 patients (18%) with navicular stress fractures received the literature-recommended treatment of at least 6 weeks' nonweightbearing cast immobilization. Of these 11 patients, only 6 (55%) returned to sports at their previous level. Only 3 patients with navicular stress fractures regained normal imaging appearance at follow-up. Pain score, stiffness, sporting success, current sporting involvement, and recurrence/time to recurrence were not statistically associated with computed tomographic or magnetic resonance imaging parameters. Of 9 patients with navicular stress reactions, 7 developed clinical and radiological features of navicular stress fracture, but 6 of 9 patients (67%) returned successfully to sports

  1. Programmable ferroelectric tunnel memristor

    Directory of Open Access Journals (Sweden)

    Andy eQuindeau

    2014-02-01

    Full Text Available We report an analogously programmable memristor based on genuine electronic resistive switching combining ferroelectric switching and electron tunneling. The tunnel current through an 8 unit cell thick epitaxial Pb(Zr[0.2]Ti[0.8]O[3] film sandwiched between La[0.7]Sr[0.3]MnO[3] and cobalt electrodes obeys the Kolmogorov-Avrami-Ishibashi model for bidimensional growth with a characteristic switching time in the order of 10^-7 seconds. The analytical description of switching kinetics allows us to develop a characteristic transfer function that has only one parameter viz. the characteristic switching time and fully predicts the resistive states of this type of memristor.

  2. Educational Wind Tunnel

    Directory of Open Access Journals (Sweden)

    Juozas Bielskus

    2012-12-01

    Full Text Available The paper analyzes an educational wind tunnel produced by the Department of Building Energetics (DBE of Vilnius Gediminas Technical University. The equipment could be used for performing laboratory works and simple research. The article presents the projection of inflow and outlet velocity in the working chamber of DBE wind tunnel and carries out actual noise level measurement. The received data are compared with information on the level of noise generated by the fan considering instructions provided by the manufacturer. In order to assess the reliability of the computer program, simulation applying PHOENICS software has been conducted. The aim of modeling is to simulate a pilot model and to compare the obtained results with those of an analogous test presented in scientific articles.Article in Lithuanian

  3. Nanowire resonant tunneling diodes

    Science.gov (United States)

    Björk, M. T.; Ohlsson, B. J.; Thelander, C.; Persson, A. I.; Deppert, K.; Wallenberg, L. R.; Samuelson, L.

    2002-12-01

    Semiconductor heterostructures and their implementation into electronic and photonic devices have had tremendous impact on science and technology. In the development of quantum nanoelectronics, one-dimensional (1D) heterostructure devices are receiving a lot of interest. We report here functional 1D resonant tunneling diodes obtained via bottom-up assembly of designed segments of different semiconductor materials in III/V nanowires. The emitter, collector, and the central quantum dot are made from InAs and the barrier material from InP. Ideal resonant tunneling behavior, with peak-to-valley ratios of up to 50:1 and current densities of 1 nA/μm2 was observed at low temperatures.

  4. The beam dump tunnels

    CERN Multimedia

    Patrice Loïez

    2002-01-01

    In these images workers are digging the tunnels that will be used to dump the counter-circulating beams. Travelling just a fraction under the speed of light, the beams at the LHC will each carry the energy of an aircraft carrier travelling at 12 knots. In order to dispose of these beams safely, a beam dump is used to extract the beam and diffuse it before it collides with a radiation shielded graphite target.

  5. Passive fire protection measures for concrete tunnels

    NARCIS (Netherlands)

    Both, C.; Haar, P.W. van de; Tan, G.L.; Wolsink, G.M.

    1999-01-01

    executed or in the process of designing; worth mentioning are the Western Scheld tunnel (approximately 2x6.5 km), the tunnels in the Betuwe railway and the tunnels in the HSL (high velocity train) railway. The most prominent of these tunnels will be executed as bored tunnels. The Directorate-General

  6. Cubital Tunnel Syndrome: Current Concepts.

    Science.gov (United States)

    Staples, Jonathan Robert; Calfee, Ryan

    2017-10-01

    Cubital tunnel syndrome is the second most common upper extremity compressive neuropathy. In recent years, rates of surgical treatment have increased, and the popularity of in situ decompression has grown. Nonsurgical treatment, aiming to decrease both compression and traction on the ulnar nerve about the elbow, is successful in most patients with mild nerve dysfunction. Recent randomized controlled trials assessing rates of symptom resolution and ultimate success have failed to identify a preferred surgical procedure. Revision cubital tunnel surgery, most often consisting of submuscular transposition, may improve symptoms. However, ulnar nerve recovery after revision cubital tunnel surgery is less consistent than that after primary cubital tunnel surgery.

  7. Managerial Ownership Influencing Tunnelling Behaviour

    Directory of Open Access Journals (Sweden)

    Agung Juliarto

    2013-06-01

    Full Text Available This study investigates the extent and the determinants of tunnelling behaviour in five ASEAN countries (i.e. Indonesia, Malaysia, Philippines, Singapore, and Thailand. Related party transactions (RPTs in the form of loans to related parties are used as the proxy for tunnelling. With 200 firm-year observations over the period 2006-2009, this study finds a positive association between managerial ownership and the extent of tunnelling.The other important findings are that business environment (BE, foreign ownership, and independent directors are ineffective governance mechanisms to rein in tunnelling behaviour. This suggests that regulators need to evolve more effective governance mechanisms.

  8. Description of the male, larva and nymphal stages of Cryptocellus iaci (Arachnida, Ricinulei), with an overview of tarsal sensilla and other integumental structures.

    Science.gov (United States)

    Salvatierra, Lidianne; Tourinho, Ana Lúcia; Giribet, Gonzalo

    2013-01-01

    The male, larva and nymphal stages of Cryptocellus iaci Tourinho, Lo Man-Hung & Bonaldo, 2010, a species previously known only from a single female, are described based on specimens from around the type locality, in an area of both Terra Firme forest and igapó (flooded forests), at the Jufari River, Roraima State, Brazil. The specimens were illustrated using live photography, stereomicroscopy, and scanning electron microscopy, allowing us to examine and describe the large diversity of tarsal sensilla and other integumental structures in Cryptocellus and to compare them to those of the previously studied Pseudocellus. Based on the male somatic characters Cryptocellus iaci is placed in thefoedus species-group. Cryptocellus iaci has two sensilla of type 1 on the distal tarsomeres of legs III (DT III), while only one has been reported for Pseudocellus spp., suggesting a potential value in this type of character for systematic studies of the group.

  9. The centrodistal joint interosseous ligament region in the tarsus of the horse: Normal appearance, abnormalities and possible association with other tarsal lesions, including osteoarthritis.

    Science.gov (United States)

    Skelly-Smith, E; Ireland, J; Dyson, S

    2016-07-01

    There have been no detailed descriptions of the radiological appearance of the centrodistal joint interosseous ligament region in horses with and without distal tarsal joint pain. To describe the normal radiological appearance of the centrodistal joint interosseous ligament region; to determine the prevalence of mineralisation or ossification of the interosseous ligament; and to describe radiological abnormalities surrounding the interosseous space and concurrent radiological abnormalities in the tarsus. The association between interosseous ligament region abnormalities and radiological evidence of osteoarthritis of the centrodistal joint was assessed. Retrospective study. Case records and radiographs of all horses/ponies (n = 700) that underwent radiographic examination of one/both tarsi over 7 years were reviewed. Case history, height, bodyweight and cause(s) of lameness were recorded. Factors associated with abnormalities of the centrodistal interosseous ligament region were assessed using logistic regression analysis. The normal interosseous space was an oval or circular-shaped radiolucent area bordered proximally and distally by a rim of bone of uniform opacity and thickness, which varied in thickness among animals. Abnormalities of the interosseous ligament region of the lame(r) limb were evident in 121/700 (17.3%; 95% confidence interval 14.5-20.1%) animals. Increasing bodyweight was associated with decreased odds of interosseous ligament region abnormalities. Forty-seven animals (6.7%; 95% confidence interval 4.9-8.6%) had radiological evidence of osteoarthritis of the centrodistal joint. A greater proportion of animals with interosseous ligament region abnormalities (36.4%) had radiological evidence of osteoarthritis of the centrodistal joint, compared to those with normal interosseous ligament regions (0.5%; Pregion abnormalities and osteoarthritis of the centrodistal joint were not necessarily associated with distal tarsal joint pain. There is an

  10. Icing Research Tunnel

    Science.gov (United States)

    Chennault, Jonathan

    2004-01-01

    The Icing Research Tunnel in Building 11 at the NASA Glenn Research Center is committed to researching the effects of in flight icing on aircraft and testing ways to stop the formation of hazardous icing conditions on planes. During this summer, I worked here with Richard DelRosa, the lead engineer for this area. address one of the major concerns of aviation: icing conditions. During the war, many planes crashed (especially supply planes going over the.Himalayas) because ice built up in their wings and clogged the engines. To this day, it remains the largest ice tunnel in the world, with a test section that measures 6 feet high, 9 feet long, and 20 feet wide. It can simulate airspeeds from 50 to 300 miles per hour at temperatures as low as -50 Fahrenheit. Using these capabilities, IRT can simulate actual conditions at high altitudes. The first thing I did was creating a cross reference in Microsoft Excel. It lists commands for the DPU units that control the pressure and temperature variations in the tunnel, as well as the type of command (keyboard, multiplier, divide, etc). The cross reference also contains the algorithm for every command, and which page it is listed in on the control sheet (visual Auto-CAD graphs, which I helped to make). I actually spent most of the time on the computer using Auto-CAD. I drew a diagram of the entire icing tunnel and then drew diagrams of its various parts. Between my mentor and me, we have drawings of every part of it, from the spray bars to the thermocouples, power cabinets, input-output connectors for power systems, and layouts of various other machines. I was also responsible for drawing schematics for the Escort system (which controls the spray bars), the power system, DPUs, and other electrical systems. In my spare time, I am attempting to build and program the "toddler". Toddler is a walking robot that I have to program in PBASIC language. When complete, it should be able to walk on level terrain while avoiding obstacles in

  11. Wind tunnel AVERT model

    Directory of Open Access Journals (Sweden)

    Adrian DOBRE

    2009-09-01

    Full Text Available The AVERT project aims to asses the oscillatory blowing on the flap for a high-lift configuration (wing with flap, and involves both experimental (low speed wind tunnel INCAS and numerical activities.At low speed the active flow control may lead to a reduction or elimination of the flow separation on the high-lift devices, such as flaps, and involves the introduction or re distribution of momentum within the boundary layer.High-lift systems utilized as particular profiles at a certain offset of the main wing may solve the disagreement between the requirements of cruise flight and landing, especially for low velocity take-off.

  12. Magnetic tunnel junctions with monolayer hexagonal boron nitride tunnel barriers

    Energy Technology Data Exchange (ETDEWEB)

    Piquemal-Banci, M.; Galceran, R.; Bouzehouane, K.; Anane, A.; Petroff, F.; Fert, A.; Dlubak, B.; Seneor, P. [Unité Mixte de Physique, CNRS, Thales, Univ. Paris-Sud, Université Paris-Saclay, Palaiseau 91767 (France); Caneva, S.; Martin, M.-B.; Weatherup, R. S.; Kidambi, P. R.; Robertson, J.; Hofmann, S. [Department of Engineering, University of Cambridge, Cambridge CB21PZ (United Kingdom); Xavier, S. [Thales Research and Technology, 1 avenue Augustin Fresnel, Palaiseau 91767 (France)

    2016-03-07

    We report on the integration of atomically thin 2D insulating hexagonal boron nitride (h-BN) tunnel barriers into Co/h-BN/Fe magnetic tunnel junctions (MTJs). The h-BN monolayer is directly grown by chemical vapor deposition on Fe. The Conductive Tip Atomic Force Microscopy (CT-AFM) measurements reveal the homogeneity of the tunnel behavior of our h-BN layers. As expected for tunneling, the resistance depends exponentially on the number of h-BN layers. The h-BN monolayer properties are also characterized through integration into complete MTJ devices. A Tunnel Magnetoresistance of up to 6% is observed for a MTJ based on a single atomically thin h-BN layer.

  13. Contact area between femoral tunnel and interference screw in anatomic rectangular tunnel ACL reconstruction: a comparison of outside-in and trans-portal inside-out techniques.

    Science.gov (United States)

    Hiramatsu, Kunihiko; Mae, Tatsuo; Tachibana, Yuta; Nakagawa, Shigeto; Shino, Konsei

    2017-10-20

    The purpose of this study was to compare the femoral tunnel length, the femoral graft bending angle at the femoral tunnel aperture, and the contact area between the femoral tunnel wall and an interference screw used for fixation in anatomic rectangular tunnel anterior cruciate ligament (ACL) reconstruction (ART ACLR). The study included 149 patients with primary ACL injury who underwent ART ACLR. Preoperatively, flexion angle of the index knee was checked under general anaesthesia. Those of less than 130° of passive flexion were assigned to the outside-in (OI) technique (78 patients), while the others to the trans-portal inside-out (TP) technique (71 patients). The patients underwent computed tomography with multiplanar reconstruction at 3-5 weeks post-operatively. Femoral tunnel length, graft bending angle, and contact ratio between the IFS and femoral tunnel were assessed. P < 0.05 was considered statistically significant. The femoral tunnel length in the OI technique was significantly longer than that in the TP technique (P < 0.001). The femoral graft bending angle in the OI technique was significantly more acute than that in the TP technique (P < 0.001). The contact ratio in the OI technique was significantly larger than that in the TP technique at every point in the femoral tunnel (P < 0.001). The OI technique resulted in a more acute femoral graft bending angle, longer mean femoral tunnel length, and larger contact ratio than the TP technique after ART ACLR. Retrospective comparative study, Level III.

  14. Modeling Indirect Tunneling in Silicon

    Science.gov (United States)

    Chen, Edward

    Indirect tunneling in silicon p-n junctions catches people's attention again in recent years. First, the phenomenon induces a serious leakage problem, so called gate-induced drain leakage (GIDL) effect, in modern metal-oxide-semiconductor field-effect transistors (MOSFETs). Second, it is utilized to develop a novel tunneling transistor with the sharp turn-on ability for continuing ITRS roadmap. Although the indirect tunneling is important for the state-of-the-art transistor-technology, the accuracy of the present tunneling models in technology computer-aided design (TCAD) tools is still vague. In the research work, the theory of indirect tunneling in silicon has been thoroughly studied. The phonon-assisted tunneling model has been developed and compared with the existing ones in the Sentaurus-Synopsys, Medici-Synopsys, and Atlas-Silvaco TCAD tools. Beyond these existing models, ours successfully predicts the indirect tunneling current under the different field direction in silicon. In addition, bandgap narrowing in heavily-doped p-n junctions under the reverse-biased condition is also studied during the model development. At the end of the research work, the application to low standby power (LSTP) transistors is demonstrated to show the capability of our tunneling model in the device level.

  15. Results of carpal tunnel release

    NARCIS (Netherlands)

    Prick, J.J.W; Blaauw, G.; Vredeveld, J.W.; Oosterloo, Sebe J.

    We evaluated, by means of a prospective study, the results of carpal tunnel release both clinically and electrophysiologically in 188 patients with a carpal tunnel syndrome. A questionnaire was completed by patient and surgeon pre- and post-operatively (6 and 12 months after operation), when

  16. Early Childhood: Funnels and Tunnels.

    Science.gov (United States)

    Fowlkes, Mary Anne

    1985-01-01

    Suggests using funnels and tunnels in combination with water, blocks, transportation toys, and other materials to help teach preschoolers to make predictions. Many examples are included for using funnels to understand properties of liquids and for using tunnels to predict order. (DH)

  17. POEM and Submucosal Tunneling.

    Science.gov (United States)

    Werner, Yuki B; Rösch, Thomas

    2016-06-01

    Submucosal endoscopy has introduced new and important aspects into gastrointestinal endoscopic therapeutics by opening the way to interventions even outside of the GI tract. At present, innovative techniques for submucosal endoscopy in different esophageal diseases include peroral endoscopic myotomy (POEM) for idiopathic achalasia and related motility disorders, submucosal tunneling endoscopic resection (STER) for submucosal tumors arising from the muscularis propria, and endoscopic submucosal tunneling dissection (ESTD) for superficial esophageal neoplastic lesions. POEM for achalasia-still a rare disease-is currently evaluated in comparison to endoscopic and surgical standard therapies, while this procedure enabling a long thoracic myotomy might constitute an advantage over the laparoscopic approach in treatments of spastic esophageal diseases. Removal of smaller submucosal esophageal tumors may appear tempting, but the clinical indications are limited by the facts that the vast majority of such smaller tumors are asymptomatic and benign.For all these innovative and technically demanding techniques, learning curves have to be taken into account, not only with regard to technical competence but also to clinical assessment, ranging from proper indication and patient selection to the management of (potential) complications and logistics/back-up. Although preliminary results from high-skilled endoscopic centers have been very encouraging, long-term data as well as prospective randomized controlled trials are needed to validate the efficacy and safety of the modalities.

  18. Tunneling magnetic force microscopy

    Science.gov (United States)

    Burke, Edward R.; Gomez, Romel D.; Adly, Amr A.; Mayergoyz, Isaak D.

    1993-01-01

    We have developed a powerful new tool for studying the magnetic patterns on magnetic recording media. This was accomplished by modifying a conventional scanning tunneling microscope. The fine-wire probe that is used to image surface topography was replaced with a flexible magnetic probe. Images obtained with these probes reveal both the surface topography and the magnetic structure. We have made a thorough theoretical analysis of the interaction between the probe and the magnetic fields emanating from a typical recorded surface. Quantitative data about the constituent magnetic fields can then be obtained. We have employed these techniques in studies of two of the most important issues of magnetic record: data overwrite and maximizing data-density. These studies have shown: (1) overwritten data can be retrieved under certain conditions; and (2) improvements in data-density will require new magnetic materials. In the course of these studies we have developed new techniques to analyze magnetic fields of recorded media. These studies are both theoretical and experimental and combined with the use of our magnetic force scanning tunneling microscope should lead to further breakthroughs in the field of magnetic recording.

  19. Tunneling Ionization of Diatomic Molecules

    DEFF Research Database (Denmark)

    Svensmark, Jens Søren Sieg

    2016-01-01

    When a molecule is subject to a strong laser field, there is a probability that an electron can escape, even though the electrons are bound by a large potential barrier. This is possible because electrons are quantum mechanical in nature, and they are therefore able to tunnel through potential...... barriers, an ability classical particles do not possess. Tunnelling is a fundamental quantum mechanical process, a process that is distinctly non-classical, so solving this tunnelling problem is not only relevant for molecular physics, but also for quantum theory in general. In this dissertation the theory...... of tunneling ionizaion of molecules is presented and the results of numerical calculations are shown. One perhaps surprising result is, that the frequently used Born-Oppenheimer approximation breaks down for weak fields when describing tunneling ionization. An analytic theory applicable in the weak-field limit...

  20. Surgical Demographics of Carpal Tunnel Syndrome and Cubital Tunnel Syndrome Over 5 Years at a Single Institution.

    Science.gov (United States)

    Zhang, Dafang; Collins, Jamie E; Earp, Brandon E; Blazar, Philip

    2017-08-12

    Carpal tunnel and cubital tunnel syndrome are the 2 most common upper-limb compressive neuropathies. However, whether the characteristics of patient populations undergoing surgery for these conditions are similar is unclear in terms of demographics and concomitant pathologies. Our null hypothesis was that there are no identifiable differences between these patient populations. A retrospective cohort study was performed by billing system query using Common Procedural Terminology (CPT) codes for all patients who underwent open carpal tunnel release (CTR) (CPT code 64721) and/or open cubital tunnel surgery (CPT code 64718) by 1 of 4 hand surgeons from August 2008 to July 2013. Application of exclusion criteria of acute trauma, revision surgery, neoplasm, age less than 18 years, and inaccurate or insufficient records resulted in identification of 1,114 patients who underwent CTR, 264 patients who underwent cubital tunnel surgery, and 76 patients who underwent both. Computerized medical records were analyzed for demographic variables, medical comorbidities, and other procedures performed under the same anesthetic. In the multivariable analysis, older age, female sex, higher body mass index, trigger finger, and de Quervain tenosynovitis were associated with CTR. Prior trauma to the anatomic site was more common in the cubital tunnel group. Diabetes mellitus was associated with patients who had both procedures. The populations of patients who undergo surgery for different upper-extremity compressive neuropathies are not homogenous: CTR is associated with older age, female sex, higher body mass index, and hand tendinopathies. Cubital tunnel decompression is associated with prior trauma to the anatomic site. Diabetic patients are more likely to have both procedures. Diabetic patients undergoing either procedure should be evaluated for other peripheral nerve compression pathologies. Diagnostic IV. Copyright © 2017 American Society for Surgery of the Hand. Published by

  1. Time Dependent Tunneling in Laser Irradiated Scanning Tunneling Microscope Junction

    Science.gov (United States)

    Park, Sookyung Hur

    A principal motivation for the studies reported in this thesis was to obtain a theoretical explanation for the experimental results obtained by Nguyen et al. (1989) to determine the traversal time of an electron tunneling through a quantum mechanical barrier in a laser irradiated STM junction. The work therefore focused on the calculation of tunneling in a time-dependent oscillating barrier, and more specifically on the inelastic contributions to the tunneling current. To do so the kinetic formalism for tunneling was modified and extended to calculate inelastic processes in an irradiated tunneling junction. Furthermore, there is significant absorption of power from the laser beam in the junction electrodes resulting in thermal effects which can influence the tunneling. Extensive analysis of the spatial and temporal temperature distributions was first done for a realistic model of the diode emitter and anode using the Green function method. Specifically we considered (i) thermal effects due to surface heating of the absorbed laser radiation, (ii) the thermoelectric emf produced in the junction due to differential heating, and (iii) resistive and Thomson heat produced in the junction by laser induced currents. Using first-order time-dependent perturbation theory we also (iv) calculated the inelastic tunneling current due to a time dependent oscillating barrier produced by the antenna geometry of the STM junction. Lastly, we (v) formulated photo-assisted tunneling due to the electron -photon interaction in the junction using the second-quantization formalism. Although quite significant results were obtained for the tunneling current density as a function of frequency, gap distance and other junction parameters which gave insights into important features of the Nguyen et al. experiment (and tunneling characteristics of an irradiated STM in general), no single expression was derived or calculated results obtained which explains or fits all their observed data, or

  2. Microbuckle tunnelling in fibre composites

    Science.gov (United States)

    Fleck, N. A.; Zhao, L. G.

    2000-09-01

    The propagation of compressive failure in multi-directional composite laminates is modelled by the tunnelling of a microbuckle within the load-bearing axial plies, with concomitant delamination of the neighbouring off-axis plies. The microbuckle tunnels at its tip in a crack-like mode III manner, and the steady state tunnelling stress is estimated by calculating the energy difference between the upstream unbuckled state and the downstream buckled state. The downstream state is analysed in detail using a plane strain analysis of a microbuckle with delaminations from its tips. In the downstream 2D problem, microbuckling of the axial plies is represented by the generation of an inclined mode II crack, with an associated microbuckling tip toughness and a constant sliding stress across its flanks. The delaminations at the interface between the axial and adjacent off-axis plies are idealised as traction-free mixed-mode interfacial cracks. Predictions of the steady-state tunnelling stress are obtained for an isotropic solid by solving an integral equation and by the finite element method; finite element techniques are then used to solve the tunnelling problem for an orthotropic solid and for a cross-ply laminate. For each case, the tunnelling stress and the delamination crack length are obtained as functions of the ratio of delamination to microbuckle toughness, and of the inclination of the microbuckle band. The tunnelling stress provides a useful lower bound for the compressive strength of a thick laminated structure.

  3. Endoscopic cubital tunnel recurrence rates.

    Science.gov (United States)

    Cobb, Tyson K; Sterbank, Patrick T; Lemke, Jon H

    2010-06-01

    Cubital tunnel syndrome is the second most common nerve entrapment in the upper extremity. There are no current publications concerning the recurrence rates after endoscopic cubital tunnel release. The purpose of this study is to evaluate the recurrence rate of endoscopic cubital tunnel release compared to published reports of recurrence following open cubital tunnel procedures. We reviewed 134 consecutive cases of endoscopic cubital tunnel release in 117 patients. There were 104 cases in 94 patients with greater than 3 months follow-up. The mean follow-up time was 736 days. They were grouped using Dellon's classification. Two literature control groups were used from published reports of recurrence rate following open cubital tunnel release. A recurrence was identified if the patient was symptom-free following surgery but had symptoms reappear 3 months or more after surgery as defined in the literature. Of the 104 cases, 92.31% had more than a 4-month follow-up. One case (0.96%) met the criteria for recurrence at 4 months postprocedure. Data were then compared to the literature control groups used from published reports of recurrence rates following open cubital tunnel release. Pooled, the combined controls had 22 of 180 cases (12.22%) with recurrences. The percentage of procedure recurrence varied significantly with p value equal to 0.0004. It is recognized that there is a lack of common classification and comparative analysis of these studies, but they do classify preoperative grading and recurrence similarly. We are 95% confident that our true recurrence rate is between 0.02% and 5.24% and that endoscopic cubital tunnel release has a recurrence rate, which is not higher than open cubital tunnel release literature controls.

  4. Tunnel fire testing and modeling the Morgex North tunnel experiment

    CERN Document Server

    Borghetti, Fabio; Gandini, Paolo; Frassoldati, Alessio; Tavelli, Silvia

    2017-01-01

    This book aims to cast light on all aspects of tunnel fires, based on experimental activities and theoretical and computational fluid dynamics (CFD) analyses. In particular, the authors describe a transient full-scale fire test (~15 MW), explaining how they designed and performed the experimental activity inside the Morgex North tunnel in Italy. The entire organization of the experiment is described, from preliminary evaluations to the solutions found for management of operational difficulties and safety issues. This fire test allowed the collection of different measurements (temperature, air velocity, smoke composition, pollutant species) useful for validating and improving CFD codes and for testing the real behavior of the tunnel and its safety systems during a diesel oil fire with a significant heat release rate. Finally, the fire dynamics are compared with empirical correlations, CFD simulations, and literature measurements obtained in other similar tunnel fire tests. This book will be of interest to all ...

  5. Dynamical tunneling theory and experiment

    CERN Document Server

    Keshavamurthy, Srihari

    2011-01-01

    A prominent aspect of quantum theory, tunneling arises in a variety of contexts across several fields of study, including nuclear, atomic, molecular, and optical physics and has led to technologically relevant applications in mesoscopic science. Exploring mechanisms and consequences, Dynamical Tunneling: Theory and Experiment presents the work of international experts who discuss the considerable progress that has been achieved in this arena in the past two decades.Highlights in this volume include:A historical introduction and overview of dynamical tunneling, with case histories ranging from

  6. Pathophysiology of carpal tunnel syndrome

    Science.gov (United States)

    Aboonq, Moutasem S.

    2015-01-01

    Carpal tunnel syndrome (CTS) is the most common median nerve neuropathy, accounting for 90% of all neuropathies. Carpal tunnel syndrome presents in 3.8% of the general population, with a higher prevalence among women. There are several risk factors associated with CTS, including both medical and non medical factors. The pathophysiologic mechanisms involved in the median nerve compression and traction are thought to be complex, and as yet are not fully understood. The present review aimed to provide an overview of the pathophysiology of median nerve neuropathy in the carpal tunnel, and subsequent development of CTS. PMID:25630774

  7. Finding optimal ventilation control for highway tunnels

    NARCIS (Netherlands)

    Ferki, Lukáš; Meinsma, Gjerrit

    2007-01-01

    A control scheme for highway tunnels is designed based on a static model of the highway tunnel. The controller is designed to keep the exhaust levels inside the tunnel below given limits. The control is then simulated on a dynamical model of a highway tunnel.

  8. Carpal tunnel syndrome - Part II (treatment,

    Directory of Open Access Journals (Sweden)

    Michel Chammas

    2014-10-01

    Full Text Available The treatments for non-deficit forms of carpal tunnel syndrome (CTS are corticoid infiltration and/or a nighttime immobilization brace. Surgical treatment, which includes sectioning the retinaculum of the flexors (retinaculotomy, is indicated in cases of resistance to conservative treatment in deficit forms or, more frequently, in acute forms. In minimally invasive techniques (endoscopy and mini-open, and even though the learning curve is longer, it seems that functional recovery occurs earlier than in the classical surgery, but with identical long-term results. The choice depends on the surgeon, patient, severity, etiology and availability of material. The results are satisfactory in close to 90% of the cases. Recovery of strength requires four to six months after regression of the pain of pillar pain type. This surgery has the reputation of being benign and has a complication rate of 0.2–0.5%.

  9. Transposição da rima palpebral em ptose miogênica mitocondrial Tarsal switch levator for mitochondrial myogenic ptosis

    Directory of Open Access Journals (Sweden)

    Lucia Miriam Dumont Lucci

    2009-04-01

    Full Text Available OBJETIVO: Relatar o uso da ressecção do tarso da pálpebra superior e enxerto na pálpebra inferior para a elevação da rima palpebral e liberação do eixo visual, sem causar complicações corneanas em pacientes portadores de ptose miogênica mitocondrial. MÉTODOS: Estudo prospectivo. A técnica cirúrgica consiste na tarsectomia da pálpebra superior e autoenxerto do tarso na lamela posterior da pálpebra inferior. As cirurgias foram realizadas sob anestesia local. No caso de diplopia, a cirurgia foi realizada em apenas um olho. RESULTADOS: O procedimento foi realizado em 9 olhos de 6 pacientes com miopatia mitocondrial. Cinco pacientes eram do sexo feminino, a média de idade foi de 59,8 anos e o seguimento variou de 30 a 60 meses. A rima palpebral elevou em todos os pacientes, descobrindo o eixo visual na posição primária do olhar e melhorando a posição viciosa de cabeça. Não houve complicações decorrentes da exposição do globo ocular. CONCLUSÃO: A técnica de transposição da rima palpebral é útil na correção do mau posicionamento das pálpebras em pacientes sem mecanismos de proteção porque eleva a pálpebra superior e a inferior, diminuindo ou eliminando o risco de causar lagoftalmo com complicações corneanas.PURPOSE: To report the use of tarsal switch levator resection procedures that lift the palpebral fissure to visual axis without causing corneal complications in patients with mitochondrial myogenic ptosis. METHODS: Prospective study. The technique consists of an upper eyelid tarsectomy, with transfer of the autologous tarsoconjunctival graft to the posterior lamella of the lower eyelid. The surgeries were performed under local anesthesia. In case of diplopia, the surgery was performed in one eye. RESULTS: Tarsal switch procedure was performed in 9 eyes of 6 patients with mitochondrial myopathy. There were 5 women; the average age was 59.8 years and the follow-up ranged from 30 to 60 months. The palpebral

  10. Analyses of tunnel stability under dynamic loads

    OpenAIRE

    Oraee, B; Hosseini, N.; Oraee, K; Gholinejad, M

    2011-01-01

    Tunnels as any other structures are affected by different loads and stresses. Generally, the loads on tunnels consist of both static and dynamic loads. These loads must both be considered in the tunnel design process. In this paper, the stability state of Jiroft water-transform tunnel is evaluated. Firstly, the in-situ stresses and then using Kirschs equations the induced stresses due to static loads in walls and crown of tunnel are calculated. Consequently, the strain caused by probable eart...

  11. The Statistics of Chaotic Tunnelling

    CERN Document Server

    Creagh, S C; Creagh, Stephen C.; Whelan, Niall D.

    2000-01-01

    We discuss the statistics of tunnelling rates in the presence of chaotic classical dynamics. This applies to resonance widths in chaotic metastable wells and to tunnelling splittings in chaotic symmetric double wells. The theory is based on using the properties of a semiclassical tunnelling operator together with random matrix theory arguments about wave function overlaps. The resulting distribution depends on the stability of a specific tunnelling orbit and is therefore not universal. However it does reduce to the universal Porter-Thomas form as the orbit becomes very unstable. For some choices of system parameters there are systematic deviations which we explain in terms of scarring of certain real periodic orbits. The theory is tested in a model symmetric double well problem and possible experimental realisations are discussed.

  12. Free Surface Water Tunnel (FSWT)

    Data.gov (United States)

    Federal Laboratory Consortium — Description: The Free Surface Water Tunnel consists of the intake plenum, the test section and the exit plenum. The intake plenum starts with a perforated pipe that...

  13. Flatback airfoil wind tunnel experiment.

    Energy Technology Data Exchange (ETDEWEB)

    Mayda, Edward A. (University of California, Davis, CA); van Dam, C.P. (University of California, Davis, CA); Chao, David D. (University of California, Davis, CA); Berg, Dale E.

    2008-04-01

    A computational fluid dynamics study of thick wind turbine section shapes in the test section of the UC Davis wind tunnel at a chord Reynolds number of one million is presented. The goals of this study are to validate standard wind tunnel wall corrections for high solid blockage conditions and to reaffirm the favorable effect of a blunt trailing edge or flatback on the performance characteristics of a representative thick airfoil shape prior to building the wind tunnel models and conducting the experiment. The numerical simulations prove the standard wind tunnel corrections to be largely valid for the proposed test of 40% maximum thickness to chord ratio airfoils at a solid blockage ratio of 10%. Comparison of the computed lift characteristics of a sharp trailing edge baseline airfoil and derived flatback airfoils reaffirms the earlier observed trend of reduced sensitivity to surface contamination with increasing trailing edge thickness.

  14. Bijzondere belastingen in tunnels : Eindrapport

    NARCIS (Netherlands)

    Molenaar, D.J.; Weerheijm, J.; Vervuurt, A.; Burggraaf, H.; Roekaerts, D.; Meijers, P.

    2009-01-01

    Verkeerstunnels en overkapte wegen (landtunnels) komen de milieukundige en stedenbouwkundige inpassing ten goede en maken meervoudig ruimtegebruik in de stad mogelijk. Het aantal tunnels en overkappingen groeit dan ook. Dit maakt het vervoer van explosiegevaarlijke stoffen en onder hoge druk

  15. Long-term tunnel behaviour and ground movements after tunnelling in clayey soils

    Directory of Open Access Journals (Sweden)

    Kenichi Soga

    2017-09-01

    Full Text Available Long term ground movements above a tunnel may continue to increase with time after tunnelling in clayey soils as the tunnelling-induced excess pore water pressures dissipate, whilst the changing earth pressure acting on the tunnel leads to further tunnel deformation during consolidation. Furthermore the tunnel itself introduces new drainage conditions; that is, depending on the drainage condition of the tunnel lining, the effective stresses around the tunnel change with time, inducing further soil consolidation. A seepage rate from low permeability clayey soil is often very small and the groundwater seeping into the tunnel can evaporate quickly. Although a tunnel may look impermeable because the surface looks dry, it is possible that the tunnel drainage conditions are actually permeable. This paper summarises the investigation of soil-tunnel consolidation interaction, particularly focusing on ground surface movements and tunnel lining deformation in the interest of engineering concerns. Analysis results show that tunnel lining permittivity relative to the permeability of the surrounding ground plays an important role on both long-term ground movements as well as tunnel lining behaviour. The findings published in literature are reviewed step by step starting from a single tunnel, twin tunnels to complex cross passage structures. The mechanisms of tunnelling-induced soil consolidation for these structures are identified and, where applicable, possible engineering methodologies to assess the magnitude of long-term ground surface settlements and tunnel lining loads are proposed.

  16. Active damper wind tunnel test

    Science.gov (United States)

    2008-01-01

    Active damper wind tunnel test in support of the development of Constellation/Ares. Testing of the 1% and .548% models for active damper and wall interference assessment in support of the Ares/CLV integrated vehicle. This test occurred at the 11 foot wind tunnel at the Ames Research Center, California. This image is extracted from high definition video file and is the highest resolution available.

  17. Safety in tunnels : transport of dangerous goods through road tunnels : highlights

    Science.gov (United States)

    2001-10-01

    A serious incident involving dangerous goods in a tunnel can be extremely costly in terms of loss of human lives, environmental degradation, tunnel damage and transport disruption. On the other hand, needlessly banning dangerous goods from tunnels ma...

  18. MANAGEMENT OF TUNNELS ON THE ZAGREB – MACELJ MOTORWAY IN THE COURSE OF TUNNELS EXPLOITATION

    OpenAIRE

    Deković, Zvonimir; Pili, Igor

    2012-01-01

    The paper focuses on the features of management of tunnels on the Zagreb-Macelj motorway. Management of tunnels is represented trough public-private partnership model that is applied on the Zagreb-Macelj motorway. In the course of tunnel operation and maintenance in the first five years of tunnels exploitation, the emphasis is put on the maintenance of the tunnel equipment systems. Tunnels as part of the motorway alignment are the most demanding facilities for maintaining appropriate safety a...

  19. MANAGEMENT OF TUNNELS ON THE ZAGREB – MACELJ MOTORWAY IN THE COURSE OF TUNNELS EXPLOITATION

    OpenAIRE

    Zvonimir Deković; Igor Pili

    2012-01-01

    he paper focuses on the features of management of tunnels on the Zagreb-Macelj motorway. Management of tunnels is represented trough public-private partnership model that is applied on the Zagreb-Macelj motorway. In the course of tunnel operation and maintenance in the first five years of tunnels exploitation, the emphasis is put on the maintenance of the tunnel equipment systems. Tunnels as part of the motorway alignment are the most demanding facilities for maintaining appropriate safety an...

  20. Osteossíntese distal de tíbia por transfixação tíbio-tarsal em pequenos animais

    Directory of Open Access Journals (Sweden)

    Teixeira Marcelo Weinstein

    1999-01-01

    Full Text Available Neste experimento foram utilizados 15 animais, 11 caninos e 4 felinos, portadores de fratura distal de tíbia, tratados pela imobilização tíbio-tarsal com um fixador externo. O aparelho na maioria dos casos apresentou uma configuração consistindo de dois pinos na porção proximal da tíbia, um ou dois no calcâneo e um ou dois pinos nos metatarsianos, todos conectados externamente por uma barra de acrílico autopolimerizante. O aparelho foi removido em média aos 45 dias de pós-operatório, quando foi observado radiograficamente o desaparecimento da linha de fratura óssea. Quatorze animais (93,3% tiveram recuperação funcional total do membro operado, com perfeita deambulação, uma semana após a remoção do fixador. Diante dos resultados obtidos, pode-se afirmar que a técnica é eficaz na correção de fraturas distais de tíbia, inclusive as expostas.

  1. Acupuncture for acute hordeolum

    Science.gov (United States)

    Cheng, Ke; Law, Andrew; Guo, Menghu; Wieland, L. Susan; Shen, Xueyong; Lao, Lixing

    2017-01-01

    Background Hordeolum is an acute, purulent inflammation of the eyelid margin usually caused by obstructed orifices of the sebaceous glands of the eyelid. The condition, which affects sebaceous glands internally or externally, is common. When the meibomian gland in the tarsal plate is affected, internal hordeolum occurs, while when the glands of Zeis or Moll associated with eyelash follicles are affected, external hordeolum, or stye occurs. The onset of hordeolum is usually self limited, and may resolve in about a week with spontaneous drainage of the abscess. When the condition is severe, it can spread to adjacent glands and tissues. Recurrences are very common. As long as an internal hordeolum remains unresolved, it can develop into a chalazion or generalized eyelid cellulitis. Acupuncture is a traditional Chinese medical therapy aimed to treat disease by using fine needles to stimulate specific points on the body. However, it is unclear if acupuncture is an effective and safe treatment for acute hordeolum. Objectives The objective of this review was to investigate the effectiveness and safety of acupuncture to treat acute hordeolum compared with no treatment, sham acupuncture, or other active treatment. We also compared the effectiveness and safety of acupuncture plus another treatment with that treatment alone. Search methods We searched CENTRAL, Ovid MEDLINE, Ovid MEDLINE In-Process and Other Non-Indexed Citations, Ovid MEDLINE Daily, Ovid OLDMEDLINE, Embase, PubMed, Latin American and Caribbean Health Sciences Literature Database (LILACS), three major Chinese databases, as well as clinical trial registers all through 7 June 2016. We reviewed the reference lists from potentially eligible studies to identify additional randomised clinical trials (RCTs). Selection criteria We included RCTs of people diagnosed with acute internal or external hordeola. We included RCTs comparing acupuncture with sham acupuncture or no treatment, other active treatments, or

  2. Current noise in tunnel junctions

    Energy Technology Data Exchange (ETDEWEB)

    Frey, Moritz; Grabert, Hermann [Physikalisches Institut, Universitaet Freiburg, Hermann-Herder-Strasse 3, 79104, Freiburg (Germany)

    2017-06-15

    We study current fluctuations in tunnel junctions driven by a voltage source. The voltage is applied to the tunneling element via an impedance providing an electromagnetic environment of the junction. We use circuit theory to relate the fluctuations of the current flowing in the leads of the junction with the voltage fluctuations generated by the environmental impedance and the fluctuations of the tunneling current. The spectrum of current fluctuations is found to consist of three parts: a term arising from the environmental Johnson-Nyquist noise, a term due to the shot noise of the tunneling current and a third term describing the cross-correlation between these two noise sources. Our phenomenological theory reproduces previous results based on the Hamiltonian model for the dynamical Coulomb blockade and provides a simple understanding of the current fluctuation spectrum in terms of circuit theory and properties of the average current. Specific results are given for a tunnel junction driven through a resonator. (copyright 2016 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  3. TunnelVision: LHC Tunnel Photogrammetry System for Structural Monitoring

    CERN Document Server

    Fallas, William

    2014-01-01

    In this document an algorithm to detect deformations in the LHC Tunnel of CERN is presented. It is based on two images, one represents the ideal state of the tunnel and the other one the actual state. To find the differences between both, the algorithm is divided in three steps. First, an image enhancement is applied to make easier the detection. Second, two different approaches to reduce noise are applied to one or both images. And third, it is defined a group of characteristics about the type of deformation desired to detect. Finally, the conclusions show the effectiveness of the algorithm in the experimental results.

  4. Pseudomorphic Bipolar Quantum Resonant-Tunneling Transistor

    National Research Council Canada - National Science Library

    Seabaugh, Alan C; Frensley, William R; Randall, John N; Reed, Mark A; Farrington, Dewey L; Matyi, Richard J

    1989-01-01

    ...+ InGaAs quantum well of a double-barrier resonant-tunneling structure. The heterojunction transistor consists of an n-GaAs emitter and collector, undoped AlAs tunnel barriers, and a pseudomorphic p...

  5. Tunneling field effect transistor technology

    CERN Document Server

    Chan, Mansun

    2016-01-01

    This book provides a single-source reference to the state-of-the art in tunneling field effect transistors (TFETs). Readers will learn the TFETs physics from advanced atomistic simulations, the TFETs fabrication process and the important roles that TFETs will play in enabling integrated circuit designs for power efficiency. · Provides comprehensive reference to tunneling field effect transistors (TFETs); · Covers all aspects of TFETs, from device process to modeling and applications; · Enables design of power-efficient integrated circuits, with low power consumption TFETs.

  6. Nature of "superluminal" barrier tunneling.

    Science.gov (United States)

    Winful, Herbert G

    2003-01-17

    We show that the distortionless tunneling of electromagnetic pulses through a barrier is a quasistatic process in which the slowly varying envelope of the incident pulse modulates the amplitude of a standing wave. For pulses longer than the barrier width, the barrier acts as a lumped element with respect to the pulse envelope. The envelopes of the transmitted and reflected fields can adiabatically follow the incident pulse with only a small delay that originates from energy storage. The theory presented here provides a physical explanation of the tunneling process and resolves the mystery of apparent superluminality.

  7. Molecular series-tunneling junctions.

    Science.gov (United States)

    Liao, Kung-Ching; Hsu, Liang-Yan; Bowers, Carleen M; Rabitz, Herschel; Whitesides, George M

    2015-05-13

    Charge transport through junctions consisting of insulating molecular units is a quantum phenomenon that cannot be described adequately by classical circuit laws. This paper explores tunneling current densities in self-assembled monolayer (SAM)-based junctions with the structure Ag(TS)/O2C-R1-R2-H//Ga2O3/EGaIn, where Ag(TS) is template-stripped silver and EGaIn is the eutectic alloy of gallium and indium; R1 and R2 refer to two classes of insulating molecular units-(CH2)n and (C6H4)m-that are connected in series and have different tunneling decay constants in the Simmons equation. These junctions can be analyzed as a form of series-tunneling junctions based on the observation that permuting the order of R1 and R2 in the junction does not alter the overall rate of charge transport. By using the Ag/O2C interface, this system decouples the highest occupied molecular orbital (HOMO, which is localized on the carboxylate group) from strong interactions with the R1 and R2 units. The differences in rates of tunneling are thus determined by the electronic structure of the groups R1 and R2; these differences are not influenced by the order of R1 and R2 in the SAM. In an electrical potential model that rationalizes this observation, R1 and R2 contribute independently to the height of the barrier. This model explicitly assumes that contributions to rates of tunneling from the Ag(TS)/O2C and H//Ga2O3 interfaces are constant across the series examined. The current density of these series-tunneling junctions can be described by J(V) = J0(V) exp(-β1d1 - β2d2), where J(V) is the current density (A/cm(2)) at applied voltage V and βi and di are the parameters describing the attenuation of the tunneling current through a rectangular tunneling barrier, with width d and a height related to the attenuation factor β.

  8. Inelastic scattering in resonant tunneling

    DEFF Research Database (Denmark)

    Wingreen, Ned S.; Jacobsen, Karsten Wedel; Wilkins, John W.

    1989-01-01

    The exact resonant-tunneling transmission probability for an electron interacting with phonons is presented in the limit that the elastic coupling to the leads is independent of energy. The phonons produce transmission sidebands but do not affect the integrated transmission probability or the esc......The exact resonant-tunneling transmission probability for an electron interacting with phonons is presented in the limit that the elastic coupling to the leads is independent of energy. The phonons produce transmission sidebands but do not affect the integrated transmission probability...

  9. Complications of Carpal Tunnel Release.

    Science.gov (United States)

    Karl, John W; Gancarczyk, Stephanie M; Strauch, Robert J

    2016-04-01

    Carpal tunnel release for compression of the median nerve at the wrist is one of the most common and successful procedures in hand surgery. Complications, though rare, are potentially devastating and may include intraoperative technical errors, postoperative infection and pain, and persistent or recurrent symptoms. Patients with continued complaints after carpal tunnel release should be carefully evaluated with detailed history and physical examination in addition to electrodiagnostic testing. For those with persistent or recurrent symptoms, a course of nonoperative management including splinting, injections, occupational therapy, and desensitization should be considered prior to revision surgery. Copyright © 2016 Elsevier Inc. All rights reserved.

  10. Tunable tunneling electroresistance in ferroelectric tunnel junctions by mechanical loads.

    Science.gov (United States)

    Luo, Xin; Wang, Biao; Zheng, Yue

    2011-03-22

    Combining nonequilibrium Green function's approach with density functional theory, effects of the applied mechanical loads on polarization, electrostatic potential, and tunneling conductance of a ferroelectric tunneling junction (FTJ) have been investigated. Using the first principle calculations, we show that compressive strains can induce and enhance the polarization in ferroelectric tunnel barriers, and practically achieve ferroelectricity in two unit cell thickness under a -2.2% compressive strain. More importantly, mechanical strains can significantly change the effective electrostatic potential in FTJ and thus control its tunneling conductance, which is defined as giant piezoelectric resistance (GPR) effect. Our calculations indicate that GPR effect is particularly significant near the paraelectric/ferroelectric phase transition, and increases exponentially with the barrier thickness. Furthermore, it is also found that defects of oxygen vacancies and nitrogen doping have little impact on GPR ratio of strained FTJ. Because of its high-sensitivity to external mechanical loads, FTJ with GPR effect should be adequate for applications in agile mechanical sensors, transducers, and other multifunctional devices.

  11. Tunneling in high-K isomeric decays

    CERN Document Server

    Shizuma, T; Shimizu, Y R

    2002-01-01

    We have systematically investigated highly-K-forbidden transitions observed in the Hf, W and Os region, using the gamma-tunneling model in which low-K and high-k states interact through a process of quantum tunneling. The measured hindrance factors are compared with the values calculated using the gamma-tunneling model. Isotope dependences of gamma-tunneling probabilities particularly for neutron-rich nuclei and the relation to stimulated decays of isomers are discussed. (author)

  12. Characterization of magnetic tunnel junction test pads

    DEFF Research Database (Denmark)

    Østerberg, Frederik Westergaard; Kjær, Daniel; Nielsen, Peter Folmer

    2015-01-01

    We show experimentally as well as theoretically that patterned magnetic tunnel junctions can be characterized using the current-in-plane tunneling (CIPT) method, and the key parameters, the resistance-area product (RA) and the tunnel magnetoresistance (TMR), can be determined. The CIPT method...

  13. Fiber coupled ultrafast scanning tunneling microscope

    DEFF Research Database (Denmark)

    Keil, Ulrich Dieter Felix; Jensen, Jacob Riis; Hvam, Jørn Märcher

    1997-01-01

    We report on a scanning tunneling microscope with a photoconductive gate in the tunneling current circuit. The tunneling tip is attached to a coplanar transmission line with an integrated photoconductive switch. The switch is illuminated through a fiber which is rigidly attached to the switch...

  14. 7 CFR 58.621 - Freezing tunnels.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 3 2010-01-01 2010-01-01 false Freezing tunnels. 58.621 Section 58.621 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Standards....621 Freezing tunnels. Freezing tunnels for quick freezing at extremely low temperatures shall be...

  15. Vehicle fires and fire safety in tunnels

    Science.gov (United States)

    2002-09-20

    Tunnels present what is arguably the most hazardous environment, from the point of view of fire safety, that members of the public ever experience. The fire safety design of tunnels is carried out by tunnel engineers on the basis of a potential fire ...

  16. Railway tunnels in Europe and North America

    Science.gov (United States)

    2002-05-01

    This list of railway tunnels (longer than 1, 000 m) was compiled by the secretariat from various national and international sources. The list is intended to serve as a reference inventory for a long railway tunnels in Europe and North America. Tunnel...

  17. The road safety of motorway tunnels.

    NARCIS (Netherlands)

    2009-01-01

    This fact sheet discusses the safety of motorway tunnels in the Netherlands. Broadly speaking, it is not certain whether crashes in the Netherlands are relatively more frequent in tunnels than on open road stretches. However, there are certain factors that increase the risk in tunnels, such as the

  18. 49 CFR 177.810 - Vehicular tunnels.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false Vehicular tunnels. 177.810 Section 177.810... Information and Regulations § 177.810 Vehicular tunnels. Except as regards Class 7 (radioactive) materials... through any urban vehicular tunnel used for mass transportation. [Amdt. 177-52, 46 FR 5316, Jan. 19, 1981...

  19. All NbN tunnel junction fabrication

    Science.gov (United States)

    Leduc, H. G.; Khanna, S. K.; Stern, J. A.

    1987-01-01

    The development of SIS tunnel junctions based on NbN for mixer applications in the submillimeter range is reported. The unique technological challenges inherent in the development of all refractory-compound superconductor-based tunnel junctions are highlighted. Current deposition and fabrication techniques are discussed, and the current status of all-NbN tunnel junctions is reported.

  20. Aeronautical Wind Tunnels, Europe and Asia

    Science.gov (United States)

    2006-02-01

    site: http://sop25.kaist.ac.kr/index.html. February 2006 Page 117 of 308 European and Asian Wind Tunnels KAIST Anechoic Wind Tunnel, Korea Advanced... KAIST Anechoic Wind Tunnel.” <http://acoustic.kaist.ac.kr/research/wind.php> Korea Advanced Institute of Science and Technology. “Low Turbulence Open

  1. New Grading System and Treatment Guidelines for the Acute Ocular Manifestations of Stevens-Johnson Syndrome.

    Science.gov (United States)

    Gregory, Darren G

    2016-08-01

    To describe a new grading system and associated treatment guidelines for the acute ocular manifestations of Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN). Prospective case series. Seventy-nine consecutive patients (158 eyes) evaluated and treated for acute ocular involvement in SJS or TEN during hospitalization. Photographic and chart review of acute ocular findings, interventions received, and outcomes with regard to visual acuity, dry eye symptoms, and scarring sequelae at least 3 months after the acute illness. Visual acuity, dry eye severity, and scarring of the ocular surface and eyelids were assessed after follow-up of at least 3 months. Cases graded as mild or moderate were managed medically. All had best-corrected visual acuity (BCVA) of 20/20, no dry eye symptoms, and no scarring sequelae. Cases graded as severe or extremely severe were treated with urgent amniotic membrane transplantation (AMT) in addition to medical management. Severe cases all had BCVA of 20/20 and mild or no dry eye problems. Five of 28 patients had mild tarsal conjunctival scarring. No other scarring sequelae occurred. Nine of the 10 extremely severe cases had BCVA of 20/20 (1 was 20/30). Three of 10 had moderate scarring of the tarsal conjunctiva and lid margins and also moderate dry eyes with severe photophobia. Seven of 10 had only mild or no dry eye symptoms and scarring sequelae. This grading system facilitates decision making in the evaluation and management of the acute ocular manifestations of SJS and TEN. Mild and moderate cases have a low risk of significant scarring or visual sequelae and may be monitored and treated medically if not worsening. Severe and extremely severe cases should receive urgent AMT to decrease the risk of scarring and visual sequelae. Copyright © 2016 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.

  2. Installation in the SPS tunnel

    CERN Multimedia

    1974-01-01

    The SPS tunnel is 6910 m in circumference and has a cross section of 4 m inner diameter. It is situated at an elevation of 400 m above sea level at a depth below the surface varying between 23 and 65 m. Its walls are lined with a concrete shell of about 30 cm thickness. See also 7410043X

  3. Time tunnels meet warped passages

    CERN Multimedia

    Kushner, David

    2006-01-01

    "Just in time for its 40th anniversary, the classic sci-fi television show "The time tunnel" is out on DVD. The conceit is something every engineer can relate to: a pulled plug. Scientists in an underground lab are working on a secret government experiment in time travel. (1 page)

  4. Travelling inside the SPS tunnel

    CERN Multimedia

    1974-01-01

    The golf cart proved to be a very useful form of transport around the 7 km circumference of the machine. It could carry four passengers and pull light equipment in its trailer. Here Peter Zettwoch is the driver along a mock-up tunnel for installation tests. (see photo 7401011X and Photo Archive 7401018)

  5. Josephson tunnel junction microwave attenuator

    DEFF Research Database (Denmark)

    Koshelets, V. P.; Shitov, S. V.; Shchukin, A. V.

    1993-01-01

    A new element for superconducting electronic circuitry-a variable attenuator-has been proposed, designed, and successfully tested. The principle of operation is based on the change in the microwave impedance of a superconductor-insulator-superconductor (SIS) Josephson tunnel junction when dc bias...

  6. Apparent tunneling in chemical reactions

    DEFF Research Database (Denmark)

    Henriksen, Niels Engholm; Hansen, Flemming Yssing; Billing, G. D.

    2000-01-01

    A necessary condition for tunneling in a chemical reaction is that the probability of crossing a barrier is non-zero, when the energy of the reactants is below the potential energy of the barrier. Due to the non-classical nature (i.e, momentum uncertainty) of vibrational states this is, however...

  7. Unitary Plan Wind Tunnel Test

    Science.gov (United States)

    2008-01-01

    Shown is a wind tunnel test of the Ares model for force/moment testing in support of the Ares/Clv integrated vehicle at Langley Research Center, Virginia. The image is extracted from a high definition video file and is the highest resolution available.

  8. Praktijkervaring met calamiteiten in tunnels

    NARCIS (Netherlands)

    De Waard, D.; Brookhuis, K.A.

    2000-01-01

    The first part of this report is about experience with (catastrophic) traffic accidents in tunnels and describes interviews with representatives of Police and the Department of Transportation, as well as the results of a short questionnaire among involved policemen and victims. The primary causes of

  9. Calculating the Number of Tunnels

    NARCIS (Netherlands)

    Li, Fajie; Klette, Reinhard; RuizShulcloper, J; Kropatsch, WG

    2008-01-01

    This paper considers 2-regions of grid cubes and proposes an algorithm for calculating the number of tunnels of such a. region. The graph-theoretical algorithm proceeds layer by layer; a proof of its correctness is provided, and its time complexity is also given.

  10. A Seamless Ubiquitous Telehealthcare Tunnel

    Directory of Open Access Journals (Sweden)

    Sao-Jie Chen

    2013-08-01

    Full Text Available Mobile handheld devices are rapidly using to implement healthcare services around the World. Fundamentally, these services utilize telemedicine technologies. A disconnection of a mobile telemedicine system usually results in an interruption, which is embarrassing, and reconnection is necessary during the communication session. In this study, the Stream Control Transmission Protocol (SCTP is adopted to build a stable session tunnel to guarantee seamless switching among heterogeneous wireless communication standards, such as Wi-Fi and 3G. This arrangement means that the telemedicine devices will not be limited by a fixed wireless connection and can switch to a better wireless channel if necessary. The tunnel can transmit plain text, binary data, and video streams. According to the evaluation of the proposed software-based SCTP-Tunnel middleware shown, the performance is lower than anticipated and is slightly slower than a fixed connection. However, the transmission throughput is still acceptable for healthcare professionals in a healthcare enterprise or home care site. It is necessary to build more heterogeneous wireless protocols into the proposed tunnel-switching scheme to support all possible communication protocols. In addition, SCTP is another good choice for promoting communication in telemedicine and healthcare fields.

  11. Spinoff from Wind Tunnel Technology

    Science.gov (United States)

    1985-01-01

    Douglas Juanarena, a former NASA Langley instrument design engineer, found a solution to the problem of long, repetitive tunnel runs needed to measure airflow pressures. Electronically scanned pressure (ESP) replaced mechanical systems with electronic sensors. Juanarena licensed the NASA-patented technology and now manufactures ESP modules for research centers, aerospace companies, etc.

  12. Rehabilitation following carpal tunnel release

    NARCIS (Netherlands)

    Peters, Susan; Page, Matthew J.; Coppieters, Michel W.; Ross, Mark; Johnston, Venerina

    2016-01-01

    Background: Various rehabilitation treatments may be offered following carpal tunnel syndrome (CTS) surgery. The effectiveness of these interventions remains unclear. This is the first update of a review first published in 2013. Objectives: To review the effectiveness and safety of rehabilitation

  13. Earth Pressure on Tunnel Crown

    DEFF Research Database (Denmark)

    Andersen, Lars

    Two different analyses have been carried out in order to find the vertical earth pressure, or overburden pressure, at the crown of a tunnel going through a dike. Firstly, a hand calculation is performed using a simple dispersion of the stresses over depth. Secondly, the finite‐element program...

  14. Introduction to scanning tunneling microscopy

    CERN Document Server

    Chen, C Julian

    2008-01-01

    The scanning tunneling and the atomic force microscope, both capable of imaging individual atoms, were crowned with the Physics Nobel Prize in 1986, and are the cornerstones of nanotechnology today. This is a thoroughly updated version of this 'bible' in the field.

  15. Tunneling Flight Time, Chemistry, and Special Relativity.

    Science.gov (United States)

    Petersen, Jakob; Pollak, Eli

    2017-09-07

    Attosecond ionization experiments have not resolved the question "What is the tunneling time?". Different definitions of tunneling time lead to different results. Second, a zero tunneling time for a material particle suggests that the nonrelativistic theory includes speeds greater than the speed of light. Chemical reactions, occurring via tunneling, should then not be considered in terms of a nonrelativistic quantum theory calling into question quantum dynamics computations on tunneling reactions. To answer these questions, we define a new experimentally measurable paradigm, the tunneling flight time, and show that it vanishes for scattering through an Eckart or a square barrier, irrespective of barrier length or height, generalizing the Hartman effect. We explain why this result does not lead to experimental measurement of speeds greater than the speed of light. We show that this tunneling is an incoherent process by comparing a classical Wigner theory with exact quantum mechanical computations.

  16. Resonant tunnel magnetoresistance in a double magnetic tunnel junction

    KAUST Repository

    Useinov, Arthur

    2011-08-09

    We present quasi-classical approach to calculate a spin-dependent current and tunnel magnetoresistance (TMR) in double magnetic tunnel junctions (DMTJ) FML/I/FMW/I/FMR, where the magnetization of the middle ferromagnetic metal layer FMW can be aligned parallel or antiparallel with respect to the fixed magnetizations of the left FML and right FMR ferromagnetic electrodes. The transmission coefficients for components of the spin-dependent current, and TMR are calculated as a function of the applied voltage. As a result, we found a high resonant TMR. Thus, DMTJ can serve as highly effective magnetic nanosensor for biological applications, or as magnetic memory cells by switching the magnetization of the inner ferromagnetic layer FMW.© Springer Science+Business Media, LLC 2011.

  17. MANAGEMENT OF TUNNELS ON THE ZAGREB – MACELJ MOTORWAY IN THE COURSE OF TUNNELS EXPLOITATION

    Directory of Open Access Journals (Sweden)

    Zvonimir Deković

    2012-12-01

    Full Text Available he paper focuses on the features of management of tunnels on the Zagreb-Macelj motorway. Management of tunnels is represented trough public-private partnership model that is applied on the Zagreb-Macelj motorway. In the course of tunnel operation and maintenance in the first five years of tunnels exploitation, the emphasis is put on the maintenance of the tunnel equipment systems. Tunnels as part of the motorway alignment are the most demanding facilities for maintaining appropriate safety and operational level in order to rich continuous availability providing safe and quality of service to the motorway users. The goal of the tunnel operation and maintenance is to ensure undisturbed and safe traffic flow through the tunnels by keeping the tunnel at the normal functional conditions.

  18. Acute febrile juvenile rheumatoid arthritis in adults: cause of polyarthritis and fever.

    Science.gov (United States)

    Goldman, J A; Beard, M R; Casey, H L

    1980-05-01

    Acute febrile juvenile rheumatoid arthritis (JRA) of adult onset is often diagnosed by ruling out other problems. The classification of JRA is primarily based on the distinct type of onset, of which there are usually three: (1) acute febrile or Still's type, (2) polyarticular, and (3) monoarticular pauciarticular arthritis. Fever of unknown cause is frequently the initial symptom. This type of arthritis may be characterized by any or all of the following: unexplained high fever, rash, weight loss, lymphadenopathy, splenomegaly, pericarditis, pleurisy, pneumonitis, abdominal pain, myalgias, arthralgias, arthritis, sore throat, leukocytosis, anemia, circulating immune complexes, liver test abnormalities, and carpal-metacarpal and tarsal-metatarsal fusion. Patients often respond dramatically to anti-inflammatory agents. Corticosteroids, gold salts, penicillamine, and cytotoxic drugs have been effective for certain patients. The prognosis of the disease has been generally favorable. Although symptoms may recur, remission can be prolonged.

  19. The Third Quantization: To Tunnel or Not to Tunnel?

    Directory of Open Access Journals (Sweden)

    Mariam Bouhmadi-López

    2018-02-01

    Full Text Available Within the framework of the third quantization, we consider the possibility that an initially recollapsing baby universe can enter a stage of near de Sitter inflation by tunnelling through a Euclidean wormhole that connects the recollapsing and inflationary geometries. We present the solutions for the evolution of the scale factor in the Lorentzian and Euclidean regions as well as the probability that the baby universe indeed crosses the wormhole when it reaches its maximum size.

  20. Anatomical placement of double femoral tunnels in anterior cruciate ligament reconstruction: anteromedial tunnel first or posterolateral tunnel first?

    Science.gov (United States)

    Taketomi, Shuji; Nakagawa, Takumi; Takeda, Hideki; Nakajima, Kohei; Nakayama, Shuichi; Fukai, Atsushi; Hirota, Jinso; Kachi, Yoshinori; Kawano, Hirotaka; Miura, Toshiki; Fukui, Naoshi; Nakamura, Kozo

    2011-03-01

    The purpose of this study was to know which tunnel--the anteromedial (AM) bundle or the posterolateral (PL) bundle--should be prepared first to create the 2 femoral tunnels accurately in anatomic double-bundle (DB) anterior cruciate ligament (ACL) reconstruction. Thirty-four patients were divided into 2 groups of 17 depending on the sequence of preparation of the 2 femoral tunnels. In group A, the AM tunnel was prepared first, whereas the PL tunnel was prepared first in group P. ACL reconstruction was performed using a three-dimensional (3-D) fluoroscopy-based navigation system to place the double femoral tunnels through an accessory medial portal. The double femoral socket positioning was evaluated by 3-D computed tomography (CT) scan image. The non-anatomical placement of the femoral sockets occurred in 5 patients (29%) in group A, whereas the 2 sockets were placed anatomically in all patients in group P (P tunnels through accessory medial portal affected the resultant location of the sockets and the rate of the complications. When femoral tunnels are prepared with a transportal technique, PL tunnel first technique seems to be superior to AM first technique regarding anatomic placement. However, PL tunnel first technique accompanies the risk of socket communication.

  1. Seismic scanning tunneling macroscope - Theory

    KAUST Repository

    Schuster, Gerard T.

    2012-09-01

    We propose a seismic scanning tunneling macroscope (SSTM) that can detect the presence of sub-wavelength scatterers in the near-field of either the source or the receivers. Analytic formulas for the time reverse mirror (TRM) profile associated with a single scatterer model show that the spatial resolution limit to be, unlike the Abbe limit of λ/2, independent of wavelength and linearly proportional to the source-scatterer separation as long as the point scatterer is in the near-field region; if the sub-wavelength scatterer is a spherical impedance discontinuity then the resolution will also be limited by the radius of the sphere. Therefore, superresolution imaging can be achieved as the scatterer approaches the source. This is analogous to an optical scanning tunneling microscope that has sub-wavelength resolution. Scaled to seismic frequencies, it is theoretically possible to extract 100 Hz information from 20 Hz data by imaging of near-field seismic energy.

  2. Tunneling magnetoresistance in Si nanowires

    KAUST Repository

    Montes Muñoz, Enrique

    2016-11-09

    We investigate the tunneling magnetoresistance of small diameter semiconducting Si nanowires attached to ferromagnetic Fe electrodes, using first principles density functional theory combined with the non-equilibrium Green\\'s functions method for quantum transport. Silicon nanowires represent an interesting platform for spin devices. They are compatible with mature silicon technology and their intrinsic electronic properties can be controlled by modifying the diameter and length. Here we systematically study the spin transport properties for neutral nanowires and both n and p doping conditions. We find a substantial low bias magnetoresistance for the neutral case, which halves for an applied voltage of about 0.35 V and persists up to 1 V. Doping in general decreases the magnetoresistance, as soon as the conductance is no longer dominated by tunneling.

  3. Wildlife Tunnel Enhances Population Viability

    Directory of Open Access Journals (Sweden)

    Rodney van der Ree

    2009-12-01

    Full Text Available Roads and traffic are pervasive components of landscapes throughout the world: they cause wildlife mortality, disrupt animal movements, and increase the risk of extinction. Expensive engineering solutions, such as overpasses and tunnels, are increasingly being adopted to mitigate these effects. Although some species readily use such structures, their success in preventing population extinction remains unknown. Here, we use population viability modeling to assess the effectiveness of tunnels for the endangered Mountain Pygmy-possum (Burramys parvus in Australia. The underpasses reduced, but did not completely remove, the negative effects of a road. The expected minimum population size of a "reconnected" population remained 15% lower than that of a comparable "undivided" population. We propose that the extent to which the risk of extinction decreases should be adopted as a measure of effectiveness of mitigation measures and that the use of population modeling become routine in these evaluations.

  4. Dissipative Effect and Tunneling Time

    Directory of Open Access Journals (Sweden)

    Samyadeb Bhattacharya

    2011-01-01

    Full Text Available The quantum Langevin equation has been studied for dissipative system using the approach of Ford et al. Here, we have considered the inverted harmonic oscillator potential and calculated the effect of dissipation on tunneling time, group delay, and the self-interference term. A critical value of the friction coefficient has been determined for which the self-interference term vanishes. This approach sheds new light on understanding the ion transport at nanoscale.

  5. Digging the CNGS decay tunnel

    CERN Multimedia

    Patrice Loiez

    2002-01-01

    Products of the collision between a proton beam and a graphite target will pass through a horn containing an electric field that will produce a focused beam. These particles will decay into muon neutrinos within the tunnel that is being constructed in these images. The neutrinos will then travel 730 km to Gran Sasso in Italy where huge detectors will observe the beam to study a process called neutrino oscillation.

  6. Diagnosis of Carpal Tunnel Syndrome

    OpenAIRE

    Keith, Michael Warren; Masear, Victoria; Chung, Kevin; Maupin, Kent; Andary, Michael; Amadio, Peter C.; Barth, Richard W.; Watters, William C.; Goldberg, Michael J.; Haralson, Robert H.; Turkelson, Charles M.; Wies, Janet L.

    2009-01-01

    This clinical practice guideline was created to improve patient care by outlining the appropriate information-gathering and decision-making processes involved in managing the diagnosis of carpal tunnel syndrome. The methods used to develop this clinical practice guideline were designed to combat bias, enhance transparency, and promote reproducibility. The guideline’s recommendations are as follows: The physician should obtain an accurate patient history. The physician should perform a physica...

  7. Bidirectional resonant tunneling spin pump

    OpenAIRE

    Ting, David Z. -Y.; Cartoixà Soler, Xavier

    2003-01-01

    We propose a mechanism for achieving bidirectional spin pumping in conventional nonmagnetic semiconductorresonant tunnelingheterostructures under zero magnetic field. The device is designed specifically to take advantage of the special spin configuration described by the Rashba effect in asymmetric quantum wells. It induces the simultaneous flow of oppositely spin-polarized current components in opposite directions through spin-dependent resonant tunneling, and can thus generate significant l...

  8. Variable density turbulence tunnel facility

    Science.gov (United States)

    Bodenschatz, E.; Bewley, G. P.; Nobach, H.; Sinhuber, M.; Xu, H.

    2014-09-01

    The Variable Density Turbulence Tunnel at the Max Planck Institute for Dynamics and Self-Organization in Göttingen, Germany, produces very high turbulence levels at moderate flow velocities, low power consumption, and adjustable kinematic viscosity between 10-4 m2/s and 10-7 m2/s. The Reynolds number can be varied by changing the pressure or flow rate of the gas or by using different non-flammable gases including air. The highest kinematic viscosities, and hence lowest Reynolds numbers, are reached with air or nitrogen at 0.1 bar. To reach the highest Reynolds numbers the tunnel is pressurized to 15 bars with the dense gas sulfur hexafluoride (SF6). Turbulence is generated at the upstream ends of two measurement sections with grids, and the evolution of this turbulence is observed as it moves down the length of the sections. We describe the instrumentation presently in operation, which consists of the tunnel itself, classical grid turbulence generators, and state-of-the-art nano-fabricated hot-wire anemometers provided by Princeton University [M. Vallikivi, M. Hultmark, S. C. C. Bailey, and A. J. Smits, Exp. Fluids 51, 1521 (2011)]. We report measurements of the characteristic scales of the flow and of turbulent spectra up to Taylor Reynolds number Rλ ≈ 1600, higher than any other grid-turbulence experiment. We also describe instrumentation under development, which includes an active grid and a Lagrangian particle tracking system that moves down the length of the tunnel with the mean flow. In this configuration, the properties of the turbulence are adjustable and its structure is resolvable up to Rλ ≈ 8000.

  9. Variable density turbulence tunnel facility.

    Science.gov (United States)

    Bodenschatz, E; Bewley, G P; Nobach, H; Sinhuber, M; Xu, H

    2014-09-01

    The Variable Density Turbulence Tunnel at the Max Planck Institute for Dynamics and Self-Organization in Göttingen, Germany, produces very high turbulence levels at moderate flow velocities, low power consumption, and adjustable kinematic viscosity between 10(-4) m(2)/s and 10(-7) m(2)/s. The Reynolds number can be varied by changing the pressure or flow rate of the gas or by using different non-flammable gases including air. The highest kinematic viscosities, and hence lowest Reynolds numbers, are reached with air or nitrogen at 0.1 bar. To reach the highest Reynolds numbers the tunnel is pressurized to 15 bars with the dense gas sulfur hexafluoride (SF6). Turbulence is generated at the upstream ends of two measurement sections with grids, and the evolution of this turbulence is observed as it moves down the length of the sections. We describe the instrumentation presently in operation, which consists of the tunnel itself, classical grid turbulence generators, and state-of-the-art nano-fabricated hot-wire anemometers provided by Princeton University [M. Vallikivi, M. Hultmark, S. C. C. Bailey, and A. J. Smits, Exp. Fluids 51, 1521 (2011)]. We report measurements of the characteristic scales of the flow and of turbulent spectra up to Taylor Reynolds number R(λ) ≈ 1600, higher than any other grid-turbulence experiment. We also describe instrumentation under development, which includes an active grid and a Lagrangian particle tracking system that moves down the length of the tunnel with the mean flow. In this configuration, the properties of the turbulence are adjustable and its structure is resolvable up to R(λ) ≈ 8000.

  10. Chemicals present in automobile traffic tunnels and the possible community health hazards: a review of the literature.

    Science.gov (United States)

    Kuykendall, Jim R; Shaw, Stephanie L; Paustenbach, Dennis; Fehling, Kurt; Kacew, Sam; Kabay, Victor

    2009-08-01

    Dozens of volatile and semivolatile organic compounds can be detected in vehicle exhaust, along with numerous metals and oxides of sulfur, nitrogen, and carbon. While the adverse effects of these chemicals have been extensively studied surrounding open roadways, the hazards to local residents and commuters resulting from the presence of tunnel emission chemicals are less well known. Commuters and workers within tunnels are also exposed to tunnel atmospheres, and the risks have only been evaluated to a limited extent. Approximately 50 studies conducted at more than 35 different international traffic tunnels were reviewed in order to characterize the potential health impact on individuals residing near these tunnels. One objective of this article is to identify those chemicals that deserve further study in order to understand the hazards to humans who work in these tunnels, as well as the risks to those in the surrounding community. The second objective is to present the available information regarding the hazards to those living near these tunnels. The published information, for the most part, indicates that the concentration of most toxicants detected in communities exposed to tunnel emissions are below those concentrations that are generally considered to pose either a significant acute or chronic health hazard. However, there have been no comprehensive studies that have evaluated the concentration of all of the relevant toxicants on a real-time basis or using repetitive time-weighted average sampling. Based on our analysis of the existing information appearing in peer-reviewed literature and government reports, additional information on the variation of concentrations of various chemicals over time near the tunnel exits would be helpful. Optimally, these would be better if evaluated in conjunction with traffic magnitude and vehicle type. It would also be useful to further characterize acute exposures to commuters or tunnel workers during times of heavy volume or

  11. Autonomous Robotic Inspection in Tunnels

    Science.gov (United States)

    Protopapadakis, E.; Stentoumis, C.; Doulamis, N.; Doulamis, A.; Loupos, K.; Makantasis, K.; Kopsiaftis, G.; Amditis, A.

    2016-06-01

    In this paper, an automatic robotic inspector for tunnel assessment is presented. The proposed platform is able to autonomously navigate within the civil infrastructures, grab stereo images and process/analyse them, in order to identify defect types. At first, there is the crack detection via deep learning approaches. Then, a detailed 3D model of the cracked area is created, utilizing photogrammetric methods. Finally, a laser profiling of the tunnel's lining, for a narrow region close to detected crack is performed; allowing for the deduction of potential deformations. The robotic platform consists of an autonomous mobile vehicle; a crane arm, guided by the computer vision-based crack detector, carrying ultrasound sensors, the stereo cameras and the laser scanner. Visual inspection is based on convolutional neural networks, which support the creation of high-level discriminative features for complex non-linear pattern classification. Then, real-time 3D information is accurately calculated and the crack position and orientation is passed to the robotic platform. The entire system has been evaluated in railway and road tunnels, i.e. in Egnatia Highway and London underground infrastructure.

  12. Diagnosis of Carpal Tunnel Syndrome

    Science.gov (United States)

    Keith, Michael Warren; Masear, Victoria; Chung, Kevin; Maupin, Kent; Andary, Michael; Amadio, Peter C.; Barth, Richard W.; Watters, William C.; Goldberg, Michael J.; Haralson, Robert H.; Turkelson, Charles M.; Wies, Janet L.

    2016-01-01

    This clinical practice guideline was created to improve patient care by outlining the appropriate information-gathering and decision-making processes involved in managing the diagnosis of carpal tunnel syndrome. The methods used to develop this clinical practice guideline were designed to combat bias, enhance transparency, and promote reproducibility. The guideline’s recommendations are as follows: The physician should obtain an accurate patient history. The physician should perform a physical examination of the patient that may include personal characteristics as well as performing a sensory examination, manual muscle testing of the upper extremity, and provocative and/or discriminatory tests for alternative diagnoses. The physician may obtain electrodiagnostic tests to differentiate among diagnoses. This may be done in the presence of thenar atrophy and/or persistent numbness. The physician should obtain electrodiagnostic tests when clinical and/or provocative tests are positive and surgical management is being considered. If the physician orders electrodiagnostic tests, the testing protocol should follow the American Academy of Neurology/American Association of Neuromuscular and Electrodiagnostic Medicine/American Academy of Physical Medicine and Rehabilitation guidelines for diagnosis of carpal tunnel syndrome. In addition, the physician should not routinely evaluate patients suspected of having carpal tunnel syndrome with new technology, such as magnetic resonance imaging, computed tomography, and pressure-specified sensorimotor devices in the wrist and hand. This decision was based on an additional nonsystematic literature review following the face-to-face meeting of the work group. PMID:19474448

  13. Quantum Tunneling Affects Engine Performance.

    Science.gov (United States)

    Som, Sibendu; Liu, Wei; Zhou, Dingyu D Y; Magnotti, Gina M; Sivaramakrishnan, Raghu; Longman, Douglas E; Skodje, Rex T; Davis, Michael J

    2013-06-20

    We study the role of individual reaction rates on engine performance, with an emphasis on the contribution of quantum tunneling. It is demonstrated that the effect of quantum tunneling corrections for the reaction HO2 + HO2 = H2O2 + O2 can have a noticeable impact on the performance of a high-fidelity model of a compression-ignition (e.g., diesel) engine, and that an accurate prediction of ignition delay time for the engine model requires an accurate estimation of the tunneling correction for this reaction. The three-dimensional model includes detailed descriptions of the chemistry of a surrogate for a biodiesel fuel, as well as all the features of the engine, such as the liquid fuel spray and turbulence. This study is part of a larger investigation of how the features of the dynamics and potential energy surfaces of key reactions, as well as their reaction rate uncertainties, affect engine performance, and results in these directions are also presented here.

  14. Time dependence of tunnel statistics and the energy resolution of superconducting tunnel junctions

    Science.gov (United States)

    Verhoeve, P.; Hartog, R. den; Kozorezov, A.; Martin, D.; van Dordrecht, A.; Wigmore, J. K.; Peacock, A.

    2002-11-01

    Multiple tunneling of quasiparticle charge carriers in a superconducting tunnel junction (STJ) enhances the signal generated by a photon absorption event. It is also an additional source of noise, responsible for a substantial degradation of the energy resolution. Although tunneling is a binomial chance process, governed by a constant tunneling probability, the resulting cumulative statistics of tunnelled quasiparticles depend on time. In particular, the variance of the total number of tunneled quasiparticles reaches a minimum after a finite integration time, corresponding to a minimum in the spectral linewidth. Since the intrinsic energy resolution of the present generation of STJs is mainly limited by the scatter on the number of tunneled quasiparticles, the improvement of the tunnel noise can be experimentally tested by variation of the pulse integration time. An analytical theory is developed that describes the relation between the tunnel noise and the transfer function of the pulse integration hardware for an STJ characterized by a quasiparticle tunnel and loss time in each electrode. We present experiments that demonstrate that the noise contribution from multiple tunnelling is not constant during the time that the quasiparticles are present in the STJ, and that by proper filtering of the STJ pulses the tunnel noise can be optimized at a level which lies well below the canonical tunnel limit.

  15. New drainage tunnel of the tunnel Višňové - design and excavation

    Science.gov (United States)

    Jurík, Igor; Grega, Ladislav; Valko, Jozef; Janega, Peter

    2017-09-01

    The actual pilot tunnel dated to the period of geological and hydrogeological survey, is designed as a part of the tunnel Višňové, which is located at the section of the D1 motorway Lietavská Lúčka - Višňové - Dubná Skala in Slovakia. Drainage tunnel will be used for the drainage of the main tunnel tubes, where the maximum inflow from the eastern portal is greater than 250 l.s-1. Overlapping of the initial pilot tunnel with the profile of the southern tunnel tube led to the demolition of the portal sections of the pilot tunnel during the excavation of main tunnel tubes. These sections were replaced by new drainage tunnels, with the lengths of 288.0 meters from west portal and 538.0 meters from eastern portal, to ensure access from both portals. The new drainage tunnel is excavated under the level of the two main tunnel tubes. Drainage pipes with a diameter of 250 mm will be installed from cleaning niches in the main tunnel tubes to the new drainage tunnel.

  16. Tarsal tetramery and extreme size reduction in Anillini (Coleoptera, Carabidae, Trechinae): the case of Typhlocharis Dieck, 1869; description of three new species and definition of a new intra-generic species group.

    Science.gov (United States)

    Pérez-González, Sergio; Zaballos, Juan P

    2013-01-01

    Tarsal tetramery is a rare condition within Carabidae, only found in some members of the endogean tribe Anillini and some cases of Gehringiini. Reduction of tarsomere numbers is also reported in endogean members of other families (e.g. Curculionidae or Staphylinidae). Recent fieldwork in southwestern Spain provided specimens of three new species of the endogean Anillini Typhlocharis Dieck, 1869: T. baeturica n.sp., T. scrofa n.sp. and T. tetramera n.sp. The new species share extreme body size reduction (less than 1.1 mm), a gula partially fused to the cephalic capsule, with diffuse lateral sutures, and four tarsomeres in all the legs. Tarsal tetramery is recorded for the first time within the genus Typhlocharis and it is contrasted with the described cases in Anillini. Typhlocharis scrofa n.sp. and T. tetramera n.sp. have club-shaped gonocoxites, reminiscent of the unguiform-like morphology observed in T. quadridentata (Coiffait, 1969), supporting the hypothesis of a transitional evolution of the shape of gonocoxites. The structure of the gula is studied within the genus and includes wide, narrow and diffuse morphologies. The implications of these features and data from the new species enable us to propose a reorganization of the systematics of the genus, creating and defining a new group of species, quadridentata group. An identification key for this species group is included. The new species provides more data on syntopic species and abundance rates, brief insights on the ecology of the genus.

  17. Complications of lateral plate fixation compared with tension band wiring and pin or lag screw fixation for calcaneoquartal arthrodesis. Treatment of proximal intertarsal subluxation occurring secondary to non-traumatic plantar tarsal ligament disruption in dogs.

    Science.gov (United States)

    Barnes, D C; Knudsen, C S; Gosling, M; McKee, M; Whitelock, R G; Arthurs, G I; Ness, M G; Radke, H; Langley-Hobbs, S J

    2013-01-01

    To compare complication rates and the outcomes of these complications after lateral plate fixation with figure-of-eight tension-band-wire and pin or lag screw fixation for arthrodesis of the calcaneoquartal joint, following non-traumatic disruption of the plantar tarsal ligament in dogs. Data were collected retrospectively from five UK referral centres. Diplomate specialists and their residents performed all procedures. Referring veterinarians were contacted for long-term follow-up. Seventy-four procedures were undertaken in 61 dogs. There were 58 arthrodeses in the lateral plate group (Plate), nine in the pin and tension-band-wire group (Pin), and seven in the lag screw and tension-band wire-group (Screw). Compared to Plate (17%), further surgical intervention was required more frequently following Pin (56%, OR = 3.2) or Screw (43%, OR = 2.5) fixation. Clinical failure of arthrodesis occurred less frequently with Plate (5%) compared with Screw (43%, OR = 8.6) and Pin fixation (22%, OR = 4.4). Cases managed with external coaptation postoperatively were more likely to suffer from postoperative complications (OR = 2.2). Lateral plating was associated with fewer postoperative complications than pin and tension-band-wire fixation for arthrodesis of the calcaneoquartal joint in dogs with non-traumatic disruption of the plantar tarsal ligament.

  18. Low Temperature Scanning Tunneling Spectroscopy

    Science.gov (United States)

    Kirk, Michael Dominic

    A scanning tunneling microscope (STM) was designed and built to operate at liquid helium temperature and was used to measure highly localized electron tunneling spectroscopy. Several instruments were built, all capable of operating in many different environments: air, vacuum, liquid helium and in a transfer gas. An adaptation of one particular design was made into an atomic force microscope capable of operating at low temperatures. Using a low temperature STM, three adsorbed molecular species (liquid crystals, sorbic acid, and carbon monoxide), deposited on a graphite substrate, have been imaged at 4.2K. The inelastic tunneling spectra of these adsorbates show strong peaks in dI/dV vs V curves at energies that correspond to known vibrational modes. The increase in conductance at the onset of inelastic tunneling was measured to be as high as 100 times. The spatial variation of the spectra was measured and was seen to change dramatically on the scale of angstroms, suggesting that individual molecular bonds could be measured. A theoretical model is presented to explain the contrast seen in the STM images of adsorbed molecules, thereby explaining why adsorbed molecules appear to be more conductive than the background. The microscope proved very useful for measuring the energy gap of high temperature superconductors. These materials often have submicron grain sizes. For LaSrCuO, YBaCuO, and BiCaSrCuO, the conductance curves showed a large energy gap suggesting a strongly coupled superconductor. The conductance curves also indicated that intergrain tunneling may occur and that the background conductance varied linearly with the applied voltage. The crystalline structure of rm Bi_2 Sr_2 CaCu_2 O_ {8 + delta} was imaged by an STM operating in air and in ultra-high vacuum. From the STM images the bulk crystal structure model for this material was refined. Finally, the STM was used to make holes reproducibly on a graphite surface with diameters less than 40A. Because the

  19. Structural analysis for shallow tunnels in soft soils

    NARCIS (Netherlands)

    Vu Minh, N.; Broere, W.; Bosch, J.W.

    2017-01-01

    Generally, studies on structural design for bored tunnels focus on moderate to deep tunnels (cover-to-diameter ratio C/D ≥ 2). Such tunnel design methods cannot be used for shallow-situated bored tunnels because the influence of buoyancy is discounted, and actual loads on the tunnel lining are

  20. Tunnel design considering stress release effect

    Directory of Open Access Journals (Sweden)

    Van-hung Dao

    2009-09-01

    Full Text Available In tunnel design, the determination of installation time and the stiffness of supporting structures is very important to the tunnel stability. This study used the convergence-confinement method to determine the stress and displacement of the tunnel while considering the counter-pressure curve of the ground base, the stress release effect, and the interaction between the tunnel lining and the rock surrounding the tunnel chamber. The results allowed for the determination of the installation time, distribution and strength of supporting structures. This method was applied to the intake tunnel in the Ban Ve Hydroelectric Power Plant, in Nghe An Province, Vietnam. The results show that when a suitable displacement µ0 ranging from 0.0865 m to 0.0919 m occurrs, we can install supporting structures that satisfy the stability and economical requirements.

  1. Investigation into scanning tunnelling luminescence microscopy

    CERN Document Server

    Manson-Smith, S K

    2001-01-01

    This work reports on the development of a scanning tunnelling luminescence (STL) microscope and its application to the study of Ill-nitride semiconductor materials used in the production of light emitting devices. STL microscopy is a technique which uses the high resolution topographic imaging capabilities of the scanning tunnelling microscope (STM) to generate high resolution luminescence images. The STM tunnelling current acts as a highly localised source of electrons (or holes) which generates luminescence in certain materials. Light generated at the STM tunnelling junction is collected concurrently with the height variation of the tunnelling probe as it is scanned across a sample surface, producing simultaneous topographic and luminescence images. Due to the very localised excitation source, high resolution luminescence images can be obtained. Spectroscopic resolution can be obtained by using filters. Additionally, the variation of luminescence intensity with tunnel current and with bias voltage can provi...

  2. Tunneling anisotropic magnetoresistance in Co/AIOx/Al tunnel junctions with fcc Co (111) electrodes

    NARCIS (Netherlands)

    Wang, Kai; Tran, T. Lan Ahn; Brinks, Peter; Brinks, P.; Sanderink, Johannes G.M.; Bolhuis, Thijs; van der Wiel, Wilfred Gerard; de Jong, Machiel Pieter

    2013-01-01

    Tunneling anisotropic magnetoresistance (TAMR) has been characterized in junctions comprised of face-centered cubic (fcc) Co (111) ferromagnetic electrodes grown epitaxially on sapphire substrates, amorphous AlOx tunnel barriers, and nonmagnetic Al counterelectrodes. Large TAMR ratios have been

  3. New thermoelectric effect in tunnel junctions

    Energy Technology Data Exchange (ETDEWEB)

    Smith, A.D.; Tinkham, M.; Skocpol, W.J.

    1980-11-01

    A new type of thermoelectric current effect is derived for tunneling through oxide barriers between metals at different temperatures, for both superconducting and normal tunnel junctions. This effect was observed in both current and voltage measurements on Al-PbVb tunnel junctions in which one electrode was heated by laser irradiation. The existence of this thermoelectric effect may resolve long-standing discrepencies between experimental results and theoretical predictions for a series of point-contact experiments.

  4. The Management of Cubital Tunnel Syndrome.

    Science.gov (United States)

    Boone, Sean; Gelberman, Richard H; Calfee, Ryan P

    2015-09-01

    Symptomatic cubital tunnel syndrome is a condition that frequently prompts patients to seek hand surgical care. Although cubital tunnel syndrome is readily diagnosed, achieving complete symptom resolution remains challenging. This article reviews related anatomy, clinical presentation, and current management options for cubital tunnel syndrome with an emphasis on contemporary outcomes research. Copyright © 2015 American Society for Surgery of the Hand. Published by Elsevier Inc. All rights reserved.

  5. Electromyographic diagnosis of the carpal tunnel syndrome

    Directory of Open Access Journals (Sweden)

    K. Toyonaga

    1978-06-01

    Full Text Available Sensory conduction velocities of the median nerVe were studied from digit to palm and from palm to wrist in normal subjects and in patients with the carpal tunnel syndrome. Definite slowing was noted in the palm to wrist segment, even in the early carpal tunnel syndrome. It was noted that 37% of normal women over 40 years of age had electrophysiological evidence of the carpal tunnel syndrome.

  6. Quantum tunneling and field electron emission theories

    CERN Document Server

    Liang, Shi-Dong

    2013-01-01

    Quantum tunneling is an essential issue in quantum physics. Especially, the rapid development of nanotechnology in recent years promises a lot of applications in condensed matter physics, surface science and nanodevices, which are growing interests in fundamental issues, computational techniques and potential applications of quantum tunneling. The book involves two relevant topics. One is quantum tunneling theory in condensed matter physics, including the basic concepts and methods, especially for recent developments in mesoscopic physics and computational formulation. The second part is the f

  7. Femtosecond tunneling response of surface plasmon polaritons

    DEFF Research Database (Denmark)

    Keil, Ulrich Dieter Felix; Ha, Taekjip; Jensen, Jacob Riis

    1998-01-01

    and suggests that nanometer spatial resolution can be obtained together with femtosecond temporal resolution. This fast response, in contrast to the picosecond decay time of SPPs revealed by differential reflectivity measurements, can be attributed to a coherent superposition of SPPs rectified at the tunneling......We obtain femtosecond (200 fs) time resolution using a scanning tunneling microscope on surface plasmon polaritons (SPPs) generated by two 100 fs laser beams in total internal reflection geometry. The tunneling gap dependence of the signal clearly indicates the tunneling origin of the signal...

  8. Experimental investigation on tunnel sonic boom

    Science.gov (United States)

    Takayama, K.; Sasoh, A.; Onodera, O.; Kaneko, R.; Matsui, Y.

    1995-10-01

    Upon the entrance of a high-speed train into a relatively long train tunnel, compression waves are generated in front of the train. These compression waves subsequently coalesce into a weak shock wave so that a unpleasant sonic boom is emitted from the tunnel exit. In order to investigate the generation of the weak shock wave in train tunnels and the emission of the resulting sonic boom from the train tunnel exit and to search for methods for the reduction of these sonic booms, a 1∶300 scaled train tunnel simulator was constructed and simulation experiments were carried out using this facility. In the train tunnel simulator, an 18 mm dia. and 200 mm long plastic piston moves along a 40 mm dia. and 25 m long test section with speed ranging from 60 to 100 m/s. The tunnel simulator was tilted 8° to the floor so that the attenuation of the piston speed was not more than 10 % of its entrance speed. Pressure measurements along the tunnel simulator and holographic interferometric optical flow visualization of weak shock waves in the tunnel simulator clearly showed that compression waves, with propagation, coalesced into a weak shock wave. Although, for reduction of the sonic boom in prototype train tunnels, the installation of a hood at the entrance of the tunnels was known to be useful for their suppression, this effect was confirmed in the present experiment and found to be effective particularly for low piston speeds. The installation of a partially perforated wall at the exit of the tunnel simulator was found to smear pressure gradients at the shock. This effect is significant for higher piston speeds. Throughout the series of train tunnel simulator experiments, the combination of both the entrance hood and the perforated wall significantly reduces shock overpressures for piston speeds of u p ranging from 60 to 100 m/s. These experimental findings were then applied to a real train tunnel and good agreement was obtained between the tunnel simulator result and the

  9. Thermal transient analysis of TI8 tunnel

    CERN Document Server

    Pimenta dos Santos, M A

    2000-01-01

    The TI8 tunnel will house a proton beam transfer line of 450 GeV from the SPS to the LHC collider. This line will comprise 340 classical compact design magnets which are expected to dissipate about 120 W/m to the air along the tunnel. As the ventilation injection and extraction points are separated by approximately 2.5 Km (the length of the tunnel), a significant increase in the air bulk temperature is expected along the distance. This report presents an estimation of the air temperature evolution with time at the end of the tunnel.

  10. Seismic Response of Building Structure Near Tunnel

    Directory of Open Access Journals (Sweden)

    Zhou Zhanxue

    2017-01-01

    Full Text Available To research the influence of seismic response of building by the underground tunnel, a high-rise frame structure on the uniform field was analysed by using finite element method (FEM.The results showed that when the tunnel was located below the building the biggest influence on structural seismic response will been emerged, and made the structural displacement and natural vibration period increase and bending moment decrease. Tunnel located elsewhere on the influence of the structure response was not simply decreases with increasing of the distance, but to show some volatility. The tunnel will have little impact on seismic response of the underground part of the structure.

  11. Persistent median artery and bifid median nerve that cause carpal tunnel syndrome: A case report

    Directory of Open Access Journals (Sweden)

    Hikmet ihsan Eren

    2013-12-01

    Full Text Available Carpal tunnel syndrome can be secondary in some patients, vascular anomalies (usually a persistent median artery, median nerve variations, or both are among the etiologic factors. High division of the median nerve proximal to the carpal tunnel (known as a bifid median nerve is a median nerve anomaly that has an incidence rate of 2.8%. This rare entity is often associated with various abnormalities that are clinically relevant, such as vascular malformations (persistent median artery, aberrant muscles, and carpal tunnel syndrome. Bifid median nerve and median artery association can be seen in %2.8 of population. This anomaly has asymptomatic findings, but in some cases acute and chronic findings can be seen as well. In this article, we present intraoperatively diagnosed median nerve and median artery assosicated carpal tunel sydrome. [Hand Microsurg 2013; 2(3.000: 115-118

  12. Probing spin-polarized tunneling at high bias and temperature with a magnetic tunnel transistor

    NARCIS (Netherlands)

    Park, B.G.; Banerjee, T.; Min, B.C.; Sanderink, Johannes G.M.; Lodder, J.C.; Jansen, R.

    2005-01-01

    The magnetic tunnel transistor (MTT) is a three terminal hybrid device that consists of a tunnel emitter, a ferromagnetic (FM) base, and a semiconductor collector. In the MTT with a FM emitter and a single FM base, spin-polarized hot electrons are injected into the base by tunneling. After

  13. Mars Surface Tunnel Element Concept

    Science.gov (United States)

    Rucker, Michelle A.

    2016-01-01

    How crews get into or out of their ascent vehicle has profound implications for Mars surface architecture. Extravehicular Activity (EVA) hatches and Airlocks have the benefit of relatively low mass and high Technology Readiness Level (TRL), but waste consumables with a volume depressurization for every ingress/egress. Perhaps the biggest drawback to EVA hatches or Airlocks is that they make it difficult to keep Martian dust from being tracked back into the ascent vehicle, in violation of planetary protection protocols. Suit ports offer the promise of dust mitigation by keeping dusty suits outside the cabin, but require significant cabin real estate, are relatively high mass, and current operational concepts still require an EVA hatch to get the suits outside for the first EVA, and back inside after the final EVA. This is primarily because current designs don't provide enough structural support to protect the suits from ascent/descent loads or potential thruster plume impingement. For architectures involving more than one surface element-such as an ascent vehicle and a rover or surface habitat-a retractable tunnel is an attractive option. By pushing spacesuit don/doff and EVA operations to an element that remains on the surface, ascended vehicle mass and dust can be minimized. What's more, retractable tunnels provide operational flexibility by allowing surface assets to be re-configured or built up over time. Retractable tunnel functional requirements and design concepts being developed as part of the National Aeronautics and Space Administration's (NASA) Evolvable Mars Campaign (EMC) work will add a new ingress/egress option to the surface architecture trade space.

  14. More about tunnelling times and superluminal tunnelling (Hartmann effect)

    Energy Technology Data Exchange (ETDEWEB)

    Olkhovsky, V.S. [Ukrainian Akademy of Sciences, Kiev (Ukraine). Inst. for Nuclear Research]|[INFN-Sezione di Catania (Italy); Recami, E. [Bergamo Univ. (Italy). Facolta` di Ingegneria]|[State Univ. at Campinas, Campinas (Brazil); Raciti, F. [Catania Univ. (Italy); Zaichenko, A. [Ukrainian Akademy of Sciences, Kiev (Ukraine). Inst. for Nuclear Reserch

    1995-05-01

    Aims of the present paper are: (i) presenting and analysing the results of various numerical calculations on the penetration and return times <{tau}{sub Pen}>, <{tau}{sub Ret}>, during tunnelling inside a rectangular potential barrier, for various penetration depths x{sub f}; (ii) putting forth and discussing suitable definitions, besides of the mean values, also of the variances (or dispersions) D{sub {tau}T} and D{sub {tau}R} for the time durations of transmission and reflection processes; (iii) mentioning, moreover, that our definition <{tau}{sub T}> for the average transmission time results to constitute an improvement of the ordinary dwell- time formula; (iv) commenting, at last, on the basis of the new numerical results, upon some recent criticism by C.R. Leavens. The paper stresses that numerical evaluations confirm that the approach implied, and implies, the existence of the Hartmann effect: an effect that in these days (due to the theoretical connections between tunnelling and evanescent-wave propagation) is receiving - at Cologne, Berkeley, Florence and Vienna - indirect, but quite interesting, experimental verification.

  15. Quantum tunnelling in condensed media

    CERN Document Server

    Kagan, Yu

    1992-01-01

    The essays in this book deal with of the problem of quantum tunnelling and related behavior of a microscopic or macroscopic system, which interacts strongly with an ""environment"" - this being some form of condensed matter. The ""system"" in question need not be physically distinct from its environment, but could, for example, be one particular degree of freedom on which attention is focussed, as in the case of the Josephson junction studied in several of the papers. This general problem has been studied in many hundreds, if not thousands, of articles in the literature, in contexts as diverse

  16. Variable Density Turbulence Tunnel Facility

    OpenAIRE

    Bodenschatz, Eberhard; Bewley, Gregory P.; Nobach, Holger; Sinhuber, Michael; Xu, Haitao

    2014-01-01

    The Variable Density Turbulence Tunnel (VDTT) at the Max Planck Institute for Dynamics and Self-Organization in G\\"ottingen, Germany produces very high turbulence levels at moderate flow velocities, low power consumption and adjustable kinematic viscosity between $10^{-4} m^2/s$ and $10^{-7} m^2/s$. The Reynolds number can be varied by changing the pressure or flow rate of the gas or by using different non-flammable gases including air. The highest kinematic viscosities, and hence lowest Reyn...

  17. Cryogenic wind-tunnel technology

    Science.gov (United States)

    Kilgore, R. A.

    1977-01-01

    The cryogenic concept and the advantages it offers with respect to achieving full scale Reynolds number in a moderate size tunnel at reasonable levels of dynamic pressure are described. Aspects which must be considered during the development of a facility that uses gaseous nitrogen as the test gas are examined. These include the properties of nitrogen, particularly at high pressure; isentropic expansion and normal shock flows in nitrogen; real gas ratios; and the problem of condensation. Sources of information on cryogenic technology are cited.

  18. Acute Bronchitis

    Science.gov (United States)

    ... of bronchitis: acute and chronic. Most cases of acute bronchitis get better within several days. But your cough ... that cause colds and the flu often cause acute bronchitis. These viruses spread through the air when people ...

  19. Stress changes ahead of an advancing tunnel

    Science.gov (United States)

    Abel, J.F.; Lee, F.T.

    1973-01-01

    Instrumentation placed ahead of three model tunnels in the laboratory and ahead of a crosscut driven in a metamorphic rock mass detected stress changes several tunnel diameters ahead of the tunnel face. Stress changes were detected 4 diameters ahead of a model tunnel drilled into nearly elastic acrylic, 2??50 diameters ahead of a model tunnel drilled into concrete, and 2 diameters ahead of a model tunnel drilled into Silver Plume Granite. Stress changes were detected 7??50 diameters ahead of a crosscut driven in jointed, closely foliated gneisses and gneissic granites in an experimental mine at Idaho Springs, Colorado. These results contrast markedly with a theoretical elastic estimate of the onset of detectable stress changes at 1 tunnel diameter ahead of the tunnel face. A small compressive stress concentration was detected 2 diameters ahead of the model tunnel in acrylic, 1.25 diameters ahead of the model tunnel in concrete, and 1 diameter ahead of the model tunnel in granite. A similar stress peak was detected about 6 diameters ahead of the crosscut. No such stress peak is predicted from elastic theory. The 3-dimensional in situ stress determined in the field demonstrate that geologic structure controls stress orientations in the metamorphic rock mass. Two of the computed principal stresses are parallel to the foliation and the other principal stress is normal to it. The principal stress orientations vary approximately as the foliation attitude varies. The average horizontal stress components and the average vertical stress component are three times and twice as large, respectively, as those predicted from the overburden load. An understanding of the measured stress field appears to require the application of either tectonic or residual stress components, or both. Laboratory studies indicate the presence of proportionately large residual stresses. Mining may have triggered the release of strain energy, which is controlled by geologic structure. ?? 1973.

  20. Computational Wind Tunnel: A Design Tool for Rotorcraft Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Rotorcraft engineers traditionally use the wind tunnel to evaluate and finalize designs. Insufficient correlation between wind tunnel results and flight tests, have...

  1. Percutaneous Creation of Bare Intervascular Tunnels for Salvage of Thrombosed Hemodialysis Fistulas Without Recanalizable Outflow

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Matt Chiung-Yu, E-mail: jjychen@gmail.com [Yuan’s General Hospital, Department of Interventional Radiology (China); Wang, Yen-Chi [E-Da Hospital, Department of Radiology (China); Weng, Mei-Jui [Kaohsiung Veterans General Hospital, Department of Radiology (China)

    2015-08-15

    PurposeThis study aimed to retrospectively assess the efficacy of a bare intervascular tunnel for salvage of a thrombosed hemodialysis fistula. We examined the clinical outcomes and provided follow-up images of the bare intervascular tunnel.Materials and MethodsEight thrombosed fistulas lacked available recanalizable outflow veins were included in this study. These fistulas were salvaged by re-directing access site flow to a new outflow vein through a percutaneously created intervascular tunnel without stent graft placement. The post-intervention primary and secondary access patency rates were calculated using the Kaplan–Meier method.ResultsThe procedural and clinical success rates were 100 %. Post-intervention primary and secondary access patency at 300 days were 18.7 ± 15.8 and 87.5 ± 11.7 %, respectively. The mean follow-up period was 218.7 days (range 10–368 days). One patient died of acute myocardial infarction 10 days after the procedure. No other major complications were observed. Minor complications, such as swelling, ecchymosis, and pain around the tunnel, occurred in all of the patients.ConclusionsPercutaneous creation of a bare intervascular tunnel is a treatment option for thrombosed hemodialysis fistulas without recanalizable outflow in selected patients.

  2. Transport of dangerous goods through road tunnels

    DEFF Research Database (Denmark)

    Jørgensen, N O; Lacroix, Didier; Amundsen, F.H.

    1999-01-01

    A paper which describes the work of an OECD research group. The group has suggested a grouping of dangerous materials, a quantitative risk assessment model and a decision support model which should allow tunnel operators to determine if a given material should be allowed throug a given tunnel...

  3. Improve train tunnel. A dynamical ventilation method

    NARCIS (Netherlands)

    Phaff, J.C.; Gids, W.F. de

    1996-01-01

    Train tunnels and subways are an interesting field of ventilation. Trains move air through tunnels at rates of 600 m3/s (over 2 x 106 m3 per hour) which is much more than flow rates in buildings. Air pressures can vary up to some 3000 Pa leading to air velocities in the range of 10 to 50 m/s. This

  4. SCHEDULING TUNNELING TURP IN CARCINOMA OF THE

    African Journals Online (AJOL)

    chidectomy. This group of patients would require an additional procedure in the form of limited transurethral resection of the prostate gland (tunneling TURP) to be able to resume spontaneous voiding. The objec- tive of this study was to compare perform- ing simultaneous tunneling TURP and bilat- eral orchidectomy on one ...

  5. Quenching of tunneling magnetoresistance at low temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Lee, K.I.; Lee, J.H.; Lee, W.Y.; Shin, K.H.; Ri, H.-C.; Lee, B.C. E-mail: chan@inha.ac.kr; Rhie, K. E-mail: krhie@korea.ac.kr

    2004-05-01

    It was observed that the tunneling magnetoresistance (TMR) was quenched at low temperatures for magnetic tunnel junctions fabricated with high-energy oxidation power. The unusual temperature dependence of the TMR is attributed to the spin-flip scattering at the interface.

  6. Tunnel widening in anterior cruciate ligament reconstruction

    DEFF Research Database (Denmark)

    Clatworthy, M G; Annear, P; Bulow, J U

    1999-01-01

    We report a prospective series evaluating the incidence and degree of tunnel widening in a well-matched series of patients receiving a hamstring or patella tendon graft for anterior cruciate ligament (ACL) deficiency. We correlated tunnel widening with clinical factors, knee scores, KT-1000...

  7. Road tunnels safety according to European legislation

    Directory of Open Access Journals (Sweden)

    Fedor KÁLLAY

    2008-01-01

    Full Text Available The article deals with safety of European road tunnels in accordance with actual European legislation. Standards and recommendations of European Commission, PIARC and other professional bodies of the European Union define minimal technological requirements for equipment and operation of the tunnels in scope of Trans-European Road Network.

  8. Ultrasonographic assessment of carpal tunnel biomechanics

    NARCIS (Netherlands)

    van Doesburg, M.H.M.

    2012-01-01

    In this thesis, we searched for a way to assess flexor tendon and median nerve biomechanics, as well as subsynovial connective tissue thickness (SSCT) in the carpal tunnel with ultrasound, and tried to see if these patterns would give a clue towards understanding the etiology of carpal tunnel

  9. Water Intrusion Problems in Transit Tunnels

    Science.gov (United States)

    1986-05-01

    This report presents the findings of five case studies in which an in-depth analysis was made of tunnel water intrusion problems in transit tunnels. Water intrusion parameters of transit systems in Atlanta, Boston, Buffalo, New York and Washington, D...

  10. Totaal andere Tunnels : Denken in nieuwe richtingen

    NARCIS (Netherlands)

    Kodde, M.J.

    2008-01-01

    In 2004 zijn de eerste gedachten over een Totaal Andere Tunnel gevormd. Om deze gedachten verder vorm te geven is door het Consortium DelftCluster-COB (DC-COB) het project Totaal Andere Tunnels, ofwel TAT, opgezet binnen het overkoepelende project “Innovatief ondiep bouwen”. Aanleiding voor het

  11. A Supermagnetic Tunnel Full of Subatomic Action

    CERN Multimedia

    2008-01-01

    Last year, before the gigantic hadron supercollider at CERN research facility was installed underground, a photographer captured this picture of a 1,950 metric ton tunnel containing giant magnets that will be placed in a tunnel and kept at near-zero temperatures.

  12. Superconducting Super Collider Laboratory : tunnel boring

    CERN Multimedia

    SSC Media Production

    1999-01-01

    This film will take you down into the tunnel, show you the technology involved in boring the tunnel, and show what the SSC fmeans to the U.S. in terms of scientific discovery, innovative collaborations with industry and stimulating the job base nation-wide.

  13. Temporary closure of the tunnel

    CERN Multimedia

    Relations with the Host States Service

    2005-01-01

    Owing to major maintenance work, the tunnel linking the various parts of the CERN site will be closed from Monday 4 July to Sunday 24 July 2005 The Host State authorities have given authorisation for persons employed by CERN or the Institutes to travel and for goods belonging to these entities to be transported between the various parts of the site via Gate E (Charles de Gaulle) while this work is being carried out, subject to strict compliance with the Rules for the Use of the Tunnel (see http://dsu.web.cern.ch/dsu/dsum/hsr/DOCUMENTS/8200980415.pdf). Gate E will thus be open between 7.00 a.m. and 7.00 p.m. from Monday to Friday during the period concerned. The rules governing the use of Gate E to enter the Meyrin site between 7.30 a.m. and 9.00 a.m. or to leave the site between 5.00 p.m. and 6.30 p.m. (see http://dsu.web.cern.ch/dsu/dsum/hsr/DOCUMENTS/12222_041027.pdf)) will remain unaffected by this temporary authorisation. Relations with the Host States Service and TS-FM Group

  14. Morphological Analysis of the Carpal Tunnel

    Science.gov (United States)

    Pacek, Corey A.; Tang, Jie; Goitz, Robert J.; Kaufmann, Robert A.

    2009-01-01

    Although carpal tunnel release is one of the most commonly performed procedures in the USA, the morphology of the carpal tunnel as determined previously in the literature has been questioned. Previous methodology has been questioned for accuracy by recent studies. The purpose of this study was to perform a morphological analysis of the carpal tunnel and correlate carpal tunnel and hand dimensions. The carpal tunnels of ten cadaveric specimens were emptied of their contents and a silicone cast of the carpal tunnel was then created. This cast was then digitized, and the dimensions of the carpal tunnel were calculated. These dimensions were compared with the measured hand dimensions of the specimens. The width, depth, tilt angle, length, cross-sectional area, and volume of the carpal tunnel were 19.2 ± 1.7 mm, 8.3 ± 0.9 mm, 14.8 ± 7.8°, 12.7 ± 2.5 mm, 134.9 ± 23.6 mm2, and 1,737 ± 542 mm3, respectively. Width, depth, and cross-sectional area did not change significantly along the length of the carpal tunnel, but tilt angle did. The width of the palm strongly correlates with the width of the carpal tunnel. Other dimensional correlations did not reach statistical significance. The carpal tunnel is of uniform dimension along its length. The long axis of the carpal tunnel in cross-section rotates volarly from the radial side of the hand increasingly with distal progression along the carpal tunnel. Based on our analysis of ten cadaveric specimens, the width of the carpal tunnel may be estimated by the width of the palm using the equation: \\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$ {\\text{Widt}}{{\\text{h}}_{\\text{CT}}} = 1.285 + 0.236 \\times {\\text{Widt}}{{\\text{h}}_{\\text{palm}}} $$\\end{document}. PMID:19760464

  15. Fire safety assessment of tunnel structures

    DEFF Research Database (Denmark)

    Gkoumas, Konstantinos; Giuliani, Luisa; Petrini, Francesco

    2011-01-01

    durability provisions, commitment to environmental aspects, issues of sustainability and safety assurance, for their whole lifecycle. The design for safety of tunnel infrastructures is a multifaceted process, since there are many aspects that need to be accounted for, regarding different aspects (e.......g. structural and non structural, organizational, human behavior). This is even more truth for the fire safety design of such structures. Fire safety in tunnels is challenging because of the particular environment, bearing in mind also that a fire can occur in different phases of the tunnel’s lifecycle. Plans...... for upgrading fire safety provisions and tunnel management are also important for existing tunnels. In this study, following a brief introduction of issues regarding the above mentioned aspects, the structural performance of a steel rib for a tunnel infrastructure subject to fire is assessed by means...

  16. Experimental evidence for Wigner's tunneling time

    CERN Document Server

    Camus, Nicolas; Fechner, Lutz; Klaiber, Michael; Laux, Martin; Mi, Yonghao; Hatsagortsyan, Karen Z; Pfeifer, Thomas; Keitel, Christoph H; Moshammer, Robert

    2016-01-01

    Tunneling of a particle through a potential barrier remains one of the most remarkable quantum phenomena. Owing to advances in laser technology, electric fields comparable to those electrons experience in atoms are readily generated and open opportunities to dynamically investigate the process of electron tunneling through the potential barrier formed by the superposition of both laser and atomic fields. Attosecond-time and angstrom-space resolution of the strong laser-field technique allow to address fundamental questions related to tunneling, which are still open and debated: Which time is spent under the barrier and what momentum is picked up by the particle in the meantime? In this combined experimental and theoretical study we demonstrate that for strong-field ionization the leading quantum mechanical Wigner treatment for the time resolved description of tunneling is valid. We achieve a high sensitivity on the tunneling barrier and unambiguously isolate its effects by performing a differential study of t...

  17. High Surface Area Tunnels in Hexagonal WO₃.

    Science.gov (United States)

    Sun, Wanmei; Yeung, Michael T; Lech, Andrew T; Lin, Cheng-Wei; Lee, Chain; Li, Tianqi; Duan, Xiangfeng; Zhou, Jun; Kaner, Richard B

    2015-07-08

    High surface area in h-WO3 has been verified from the intracrystalline tunnels. This bottom-up approach differs from conventional templating-type methods. The 3.67 Å diameter tunnels are characterized by low-pressure CO2 adsorption isotherms with nonlocal density functional theory fitting, transmission electron microscopy, and thermal gravimetric analysis. These open and rigid tunnels absorb H(+) and Li(+), but not Na(+) in aqueous electrolytes without inducing a phase transformation, accessing both internal and external active sites. Moreover, these tunnel structures demonstrate high specific pseudocapacitance and good stability in an H2SO4 aqueous electrolyte. Thus, the high surface area created from 3.67 Å diameter tunnels in h-WO3 shows potential applications in electrochemical energy storage, selective ion transfer, and selective gas adsorption.

  18. Aberrant Radial Artery Causing Carpal Tunnel Syndrome

    Directory of Open Access Journals (Sweden)

    Zinon T. Kokkalis

    2016-07-01

    Full Text Available Anatomical vascular variations are rare causes of carpal tunnel syndrome. An aberrant medial artery is the most common vascular variation, while an aberrant radial artery causing carpal tunnel syndrome is even more rare, with an incidence ranging less than 3%. This article reports a patient with compression of the median nerve at the carpal tunnel by an aberrant superficial branch of the radial artery. An 80- year- old man presented with a 5-year history of right hand carpal tunnel syndrome; Tinel sign, Phalen test and neurophysiological studies were positive. Open carpal tunnel release showed an aberrant superficial branch of the radial artery with its accompanying veins running from radially to medially, almost parallel to the median nerve, ending at the superficial palmar arterial arch. The median nerve was decompressed without ligating the aberrant artery. At the last follow-up, 2 years after diagnosis and treatment the patient is asymptomatic.

  19. Aberrant Radial Artery Causing Carpal Tunnel Syndrome.

    Science.gov (United States)

    Kokkalis, Zinon T; Tolis, Konstantinos E; Megaloikonomos, Panayiotis D; Panagopoulos, Georgios N; Igoumenou, Vasilios G; Mavrogenis, Andreas F

    2016-06-01

    Anatomical vascular variations are rare causes of carpal tunnel syndrome. An aberrant medial artery is the most common vascular variation, while an aberrant radial artery causing carpal tunnel syndrome is even more rare, with an incidence ranging less than 3%. This article reports a patient with compression of the median nerve at the carpal tunnel by an aberrant superficial branch of the radial artery. An 80- year- old man presented with a 5-year history of right hand carpal tunnel syndrome; Tinel sign, Phalen test and neurophysiological studies were positive. Open carpal tunnel release showed an aberrant superficial branch of the radial artery with its accompanying veins running from radially to medially, almost parallel to the median nerve, ending at the superficial palmar arterial arch. The median nerve was decompressed without ligating the aberrant artery. At the last follow-up, 2 years after diagnosis and treatment the patient is asymptomatic.

  20. Snow and ice blocking of tunnels

    Energy Technology Data Exchange (ETDEWEB)

    Lia, Leif

    1998-12-31

    Hydroelectric power development in cold regions causes much concern about operational reliability and dam safety. This thesis studies the temperature distribution in tunnels by means of air temperature measurements in six tunnel spillways and five diversion tunnels. The measurements lasted for two consecutive winters. The air through flow tunnel is used as it causes cooling of both rock and water. In open spillway tunnels, frost reaches the entire tunnel. In spillway tunnels with walls, the frost zones reach about 100 m from the downstream end. In mildly-inclined diversion tunnels, a frost free zone is located in the middle of the tunnel and snow and ice problems were only observed in the inlet and outlet. Severe aufeis is accumulation is observed in the frost zones. The heat transfer from rock to air, water and ice is calculated and used in a prediction model for the calculation of aufeis build-up together with local field observation data. The water penetration of snow plugs is also calculated, based on the heat balance. It takes 20 to 50 days for water to enter the blocked tunnel. The empirical values are 30 to 60 days, but only 1 day if the temperature of the snow pack is 0{sup o}C. Sensitivity analyses are carried out for temperature variations in rock, snow, water and ice. Systematic field observation shows that it is important for hydropower companies to know about the effects of snow and ice blocking in an area. A risk analysis of dam safety is presented for a real case. Finally, the thesis proposes solutions which can reduce the snow and ice problems. 79 refs., 63 figs., 11 tabs.

  1. Quantitative risk assessment modeling for nonhomogeneous urban road tunnels.

    Science.gov (United States)

    Meng, Qiang; Qu, Xiaobo; Wang, Xinchang; Yuanita, Vivi; Wong, Siew Chee

    2011-03-01

    Urban road tunnels provide an increasingly cost-effective engineering solution, especially in compact cities like Singapore. For some urban road tunnels, tunnel characteristics such as tunnel configurations, geometries, provisions of tunnel electrical and mechanical systems, traffic volumes, etc. may vary from one section to another. These urban road tunnels that have characterized nonuniform parameters are referred to as nonhomogeneous urban road tunnels. In this study, a novel quantitative risk assessment (QRA) model is proposed for nonhomogeneous urban road tunnels because the existing QRA models for road tunnels are inapplicable to assess the risks in these road tunnels. This model uses a tunnel segmentation principle whereby a nonhomogeneous urban road tunnel is divided into various homogenous sections. Individual risk for road tunnel sections as well as the integrated risk indices for the entire road tunnel is defined. The article then proceeds to develop a new QRA model for each of the homogeneous sections. Compared to the existing QRA models for road tunnels, this section-based model incorporates one additional top event-toxic gases due to traffic congestion-and employs the Poisson regression method to estimate the vehicle accident frequencies of tunnel sections. This article further illustrates an aggregated QRA model for nonhomogeneous urban tunnels by integrating the section-based QRA models. Finally, a case study in Singapore is carried out. © 2010 Society for Risk Analysis.

  2. Goniometria da articulação tíbio-tarsal após imobilização temporária com fixador esquelético externo em cães

    OpenAIRE

    Alievi,Marcelo Meller; Schossler,João Eduardo; Teixeira,Marcelo Weinsten

    2004-01-01

    Neste experimento, foram utilizados 10 cães clinicamente sadios, submetidos à imobilização temporária das articulações tíbio-tarsal, intertarsal e tarso-metatarsiana direita com fixador esquelético externo, tendo por objetivo avaliar através da mensuração da flexão, da extensão e da amplitude articular os danos provocados por esta imobilização. O aparelho de fixação esquelética externa manteve a articulação em um ângulo aproximado de 135masculine e permaneceu por 45 dias. Os animais apresenta...

  3. PA01.49.Carpal tunnel syndrome: A case report

    Science.gov (United States)

    Gandhi, Rahul S; Manoj Kumar, A K

    2012-01-01

    Purpose: Carpal tunnel syndrome is an entrapment neuropathy of median nerve causing paraesthesia, pain, numbness and other symptoms in the distribution of median nerve due to its compression at wrist in carpal tunnel. Modern medicine prescribes surgery for its treatment. We report a case that was treated completely without any recurrence. Method: Case presentation: A female patient aged 23 years presented with numbness in the middle finger of left hand associated with paraesthesia, morning stiffness, loss of delicate movements of middle finger and dropping of small objects since 4 days. She consulted an allopathic doctor and was diagnosed as having Carpal tunnel syndrome (CTS). She was advised surgery. The patient was reluctant for undergoing surgery and took the medicines for 1 day, but had no relief. Next day she came to the OPD. On examination, Tinel™s percussion test and hand diagram were positive. On assessment, symptom severity scale (SSS) and functional status scale (FSS) were found to be 1.5 and 3.5 respectively, before treatment. Treatment given was varanadi kashaya, sahacharadi and supti taila, yogaraja guggulu, cap chelnar, dhanyamla dhara, shunthibaladi choorna etc, for a period of 1 month. The medicines were changed as per the condition of patient and the disease, at every follow up of 1 week, during the 1 month of treatment. Result: At the end of 1 month patient got complete relief from her complaints, and the scales SSS and FSS scored 0. Conclusion: The treatment given here aimed at release of compression by considering the involvement of doshas. The state of the disease was acute due to which complete relief was achieved. Thus if patients come to Ayurveda in early stages of the disease, prognosis will be better.

  4. Hawking Radiation and Classical Tunneling

    CERN Document Server

    Tracy, Eugene R

    2015-01-01

    Acoustic waves in fluids undergoing the transition from sub- to supersonic flow satisfy governing equations similar to those for light waves in the immediate vicinity of a black hole event horizon. This acoustic analogy has been used by Unruh and others as a conceptual model for `Hawking radiation.' Here we use variational methods, originally introduced by Brizard for the study of linearized MHD, and ray phase space methods, to analyze linearized acoustics in the presence of background flows. The variational formulation endows the evolution equations with natural Hermitian and symplectic structures that prove useful for later analysis. We derive a $2\\times 2$ normal form governing the wave evolution in the vicinity of the `event horizon.' This shows that the acoustic model can be reduced locally (in ray phase space) to a standard (scalar) tunneling process weakly coupled to a unidirectional non-dispersive wave (the `incoming wave'). Given the normal form, the Hawking `thermal spectrum' can be derived by invok...

  5. Quantitative tunneling spectroscopy of nanocrystals

    Energy Technology Data Exchange (ETDEWEB)

    First, Phillip N; Whetten, Robert L; Schaaff, T Gregory

    2007-05-25

    The proposed goals of this collaborative work were to systematically characterize the electronic structure and dynamics of 3-dimensional metal and semiconducting nanocrystals using scanning tunneling microscopy/spectroscopy (STM/STS) and ballistic electron emission spectroscopy (BEES). This report describes progress in the spectroscopic work and in the development of methods for creating and characterizing gold nanocrystals. During the grant period, substantial effort also was devoted to the development of epitaxial graphene (EG), a very promising materials system with outstanding potential for nanometer-scale ballistic and coherent devices ("graphene" refers to one atomic layer of graphitic, sp2 -bonded carbon atoms [or more loosely, few layers]). Funding from this DOE grant was critical for the initial development of epitaxial graphene for nanoelectronics

  6. Theory of dissociative tunneling ionization

    CERN Document Server

    Svensmark, Jens; Madsen, Lars Bojer

    2016-01-01

    We present a theoretical study of the dissociative tunneling ionization process. Analytic expressions for the nuclear kinetic energy distribution of the ionization rates are derived. A particularly simple expression for the spectrum is found by using the Born-Oppenheimer (BO) approximation in conjunction with the reflection principle. These spectra are compared to exact non-BO ab initio spectra obtained through model calculations with a quantum mechanical treatment of both the electronic and nuclear degrees freedom. In the regime where the BO approximation is applicable imaging of the BO nuclear wave function is demonstrated to be possible through reverse use of the reflection principle, when accounting appropriately for the electronic ionization rate. A qualitative difference between the exact and BO wave functions in the asymptotic region of large electronic distances is shown. Additionally the behavior of the wave function across the turning line is seen to be reminiscent of light refraction. For weak fiel...

  7. Rudolf Hermann, wind tunnels and aerodynamics

    Science.gov (United States)

    Lundquist, Charles A.; Coleman, Anne M.

    2008-04-01

    Rudolf Hermann was born on December 15, 1904 in Leipzig, Germany. He studied at the University of Leipzig and at the Aachen Institute of Technology. His involvement with wind tunnels began in 1934 when Professor Carl Wieselsberger engaged him to work at Aachen on the development of a supersonic wind tunnel. On January 6, 1936, Dr. Wernher von Braun visited Dr. Hermann to arrange for use of the Aachen supersonic wind tunnel for Army problems. On April 1, 1937, Dr. Hermann became Director of the Supersonic Wind Tunnel at the Army installation at Peenemunde. Results from the Aachen and Peenemunde wind tunnels were crucial in achieving aerodynamic stability for the A-4 rocket, later designated as the V-2. Plans to build a Mach 10 'hypersonic' wind tunnel facility at Kochel were accelerated after the Allied air raid on Peenemunde on August 17, 1943. Dr. Hermann was director of the new facility. Ignoring destruction orders from Hitler as WWII approached an end in Europe, Dr. Hermann and his associates hid documents and preserved wind tunnel components that were acquired by the advancing American forces. Dr. Hermann became a consultant to the Air Force at its Wright Field in November 1945. In 1951, he was named professor of Aeronautical Engineering at the University of Minnesota. In 1962, Dr. Hermann became the first Director of the Research Institute at the University of Alabama in Huntsville (UAH), a position he held until he retired in 1970.

  8. Pain and carpal tunnel syndrome.

    Science.gov (United States)

    Duckworth, Andrew D; Jenkins, Paul J; Roddam, Philip; Watts, Adam C; Ring, David; McEachan, Jane E

    2013-08-01

    Pain is not a classical symptom of carpal tunnel syndrome (CTS), with the exception of numbness that is so intense that it is described by patients as painful. The primary aim of our study was to determine which factors correlated with pain for patients diagnosed with CTS. We prospectively assessed all patients diagnosed with CTS in our unit over a 1-year period. We recorded demographic details for all patients, including past medical history, body mass index, smoking, and occupation. The diagnosis and severity of carpal tunnel syndrome were established through a combination of history, clinical assessment, and nerve conduction studies. Of 275 patients diagnosed and treated for CTS, 183 were women (67%), the mean age was 55 years (range, 22-87 y), and 166 cases were bilateral (60%). The mean body mass index was 29.5 kg/m2 (range, 17-48 kg/m2), and 81 patients smoked (30%). Patients completed a Short Form-McGill pain questionnaire (SF-MPQ) as a measure of pain at initial presentation. We assessed outcome 1 year after intervention using the Quick Disabilities of the Arm, Shoulder, and Hand (QuickDASH) score. We found no association between pain according to the SF-MPQ and the positive clinical signs of CTS or positive nerve conduction studies. Multivariate analysis demonstrated that smoking and bilateral disease independently correlated with the overall SF-MPQ, with similar findings on subanalysis. Independent factors associated with an increased improvement in the QuickDASH at 1 year were the presentation QuickDASH score, positive nerve conduction studies, and smoking. The only independent factors that correlated with pain at presentation of CTS were smoking and bilateral disease. Pain according to the SF-MPQ was not associated with classical clinical findings of the disease or with positive findings on nerve conduction testing. Prognostic I. Copyright © 2013 American Society for Surgery of the Hand. Published by Elsevier Inc. All rights reserved.

  9. Optics (communication arising): mechanism for 'superluminal' tunnelling.

    Science.gov (United States)

    Winful, Herbert G

    2003-08-07

    In their discussion of a mechanism that I proposed to explain the apparent superluminal (that is, faster than light) tunnelling of light pulses observed in photonic barrier experiments, Büttiker and Washburn used an old 'reshaping' argument that is at variance with my model and is not supported by the bulk of the experimental tunnelling evidence. The mechanism I proposed agrees with experiment and resolves a long-standing paradox - namely, the lack of dependence of tunnelling time on barrier length for thick barriers (the Hartman effect).

  10. The Thames Tideway Tunnel (3/3)

    CERN Multimedia

    CERN. Geneva

    2012-01-01

    Lecture 3: Insight into a pioneering project at the cutting edge of engineering: the upgrade to London’s failing sewerage system. With a growing population and heavier rainfall, the River Thames is regularly polluted in breach of European Directive requirements. Two new storage and transfer tunnels will run up to 85m deep under the river and will intercept and divert sewer overflows to a treatment facility in east London. The challenges faced by constructing a tunnel project of this size under the river and through London’s historic urban environment will set a new UK record for this type of tunnelling.

  11. Carpal tunnel syndrome - anatomical and clinical correlations.

    Science.gov (United States)

    Iskra, Tomasz; Mizia, Ewa; Musial, Agata; Matuszyk, Aleksandra; Tomaszewski, Krzysztof A

    2013-01-01

    Carpal tunnel syndrome (CTS) is the most common and widely known of the entrapment neuropathies in which the body's peripheral nerves are compressed. Common symptoms of CTS involve the hand and result from compression of the median nerve within the carpal tunnel. In general, CTS develops when the tissues around the median nerve irritate or compress on the nerve along its course through the carpal tunnel, however often it is very difficult to determine cause of CTS. Proper treatment (conservative or surgical) usually can relieve the symptoms and restore normal use of the wrist and hand.

  12. Advancing Test Capabilities at NASA Wind Tunnels

    Science.gov (United States)

    Bell, James

    2015-01-01

    NASA maintains twelve major wind tunnels at three field centers capable of providing flows at 0.1 M 10 and unit Reynolds numbers up to 45106m. The maintenance and enhancement of these facilities is handled through a unified management structure under NASAs Aeronautics and Evaluation and Test Capability (AETC) project. The AETC facilities are; the 11x11 transonic and 9x7 supersonic wind tunnels at NASA Ames; the 10x10 and 8x6 supersonic wind tunnels, 9x15 low speed tunnel, Icing Research Tunnel, and Propulsion Simulator Laboratory, all at NASA Glenn; and the National Transonic Facility, Transonic Dynamics Tunnel, LAL aerothermodynamics laboratory, 8 High Temperature Tunnel, and 14x22 low speed tunnel, all at NASA Langley. This presentation describes the primary AETC facilities and their current capabilities, as well as improvements which are planned over the next five years. These improvements fall into three categories. The first are operations and maintenance improvements designed to increase the efficiency and reliability of the wind tunnels. These include new (possibly composite) fan blades at several facilities, new temperature control systems, and new and much more capable facility data systems. The second category of improvements are facility capability advancements. These include significant improvements to optical access in wind tunnel test sections at Ames, improvements to test section acoustics at Glenn and Langley, the development of a Supercooled Large Droplet capability for icing research, and the development of an icing capability for large engine testing. The final category of improvements consists of test technology enhancements which provide value across multiple facilities. These include projects to increase balance accuracy, provide NIST-traceable calibration characterization for wind tunnels, and to advance optical instruments for Computational Fluid Dynamics (CFD) validation. Taken as a whole, these individual projects provide significant

  13. Extraskeletal chondroma casuing carpal tunnel syndrome: A case report

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Ok Hwa; Kim, Yeon Hee [Haeundae Paik Hospital, Inje University College of Medicine, Busan (Korea, Republic of)

    2014-03-15

    Carpal tunnel syndrome caused by extraskeletal chondroma has been scarcely reported in the literature. Authors report a case of carpal tunnel syndrome as a result of an extraskeletal chondroma arising within the carpal tunnel, and describe the radiological and pathological findings of the mass. We also discuss the differential diagnosis of the calcified space, occupying lesions that may occur in carpal tunnel.

  14. Tunneling time, exit time and exit momentum in strong field tunnel ionization

    Energy Technology Data Exchange (ETDEWEB)

    Teeny, Nicolas

    2016-10-18

    Tunnel ionization belongs to the fundamental processes of atomic physics. It is still an open question when does the electron tunnel ionize and how long is the duration of tunneling. In this work we solve the time-dependent Schroedinger equation in one and two dimensions and use ab initio quantum calculations in order to answer these questions. Additionally, we determine the exit momentum of the tunnel ionized electron from first principles. We find out results that are different from the assumptions of the commonly employed two-step model, which assumes that the electron ionizes at the instant of electric field maximum with a zero momentum. After determining the quantum final momentum distribution of tunnel ionized electrons we show that the two-step model fails to predict the correct final momentum. Accordingly we suggest how to correct the two-step model. Furthermore, we determine the instant at which tunnel ionization starts, which turns out to be different from the instant usually assumed. From determining the instant at which it is most probable for the electron to enter the tunneling barrier and the instant at which it exits we determine the most probable time spent under the barrier. Moreover, we apply a quantum clock approach in order to determine the duration of tunnel ionization. From the quantum clock we determine an average tunneling time which is different in magnitude and origin with respect to the most probable tunneling time. By defining a probability distribution of tunneling times using virtual detectors we relate both methods and explain the apparent discrepancy. The results found have in general an effect on the interpretation of experiments that measure the spectra of tunnel ionized electrons, and specifically on the calibration of the so called attoclock experiments, because models with imprecise assumptions are usually employed in order to interpret experimental results.

  15. Tunneling into quantum wires: Regularization of the tunneling Hamiltonian and consistency between free and bosonized fermions

    Science.gov (United States)

    Filippone, Michele; Brouwer, Piet W.

    2016-12-01

    Tunneling between a point contact and a one-dimensional wire is usually described with the help of a tunneling Hamiltonian that contains a δ function in position space. Whereas the leading-order contribution to the tunneling current is independent of the way this δ function is regularized, higher-order corrections with respect to the tunneling amplitude are known to depend on the regularization. Instead of regularizing the δ function in the tunneling Hamiltonian, one may also obtain a finite tunneling current by invoking the ultraviolet cutoffs in a field-theoretic description of the electrons in the one-dimensional conductor, a procedure that is often used in the literature. For the latter case, we show that standard ultraviolet cutoffs lead to different results for the tunneling current in fermionic and bosonized formulations of the theory, when going beyond leading order in the tunneling amplitude. We show how to recover the standard fermionic result using the formalism of functional bosonization and revisit the tunneling current to leading order in the interacting case.

  16. Seismic prediction ahead of tunnel construction using Rayleigh-waves

    OpenAIRE

    Jetschny, Stefan; De Nil, Denise; Bohlen, Thomas

    2008-01-01

    To increase safety and efficiency of tunnel constructions, online seismic exploration ahead of a tunnel can become a valuable tool. We developed a new forward looking seismic imaging technique e.g. to determine weak and water bearing zones ahead of the constructions. Our approach is based on the excitation and registration of tunnel surface-waves. These waves are excited at the tunnel face behind the cutter head of a tunnel boring machine and travel into drilling direction. Arriving at the fr...

  17. Teelt van vruchtgewassen in lage tunnels

    NARCIS (Netherlands)

    Wijk, van C.A.P.; Geven, C.G.M.

    1994-01-01

    Een aantal warmteminnende vruchtgewassen zijn beproefd in lage tunnels en vergeleken met onbedekte teelt en met kasteelt. Het betrof aubergine, paprika, peper en diverse typen meloen. Daar is courgette als vergelijkend gewas aan toegevoegd

  18. Development of Economic Factors in Tunnel Construction

    Science.gov (United States)

    1977-12-01

    The escalating cost of underground construction of urban transportation systems has made transit planning, especially construction cost estimating, difficult. This is a study of the cost of construction of underground, rapid transit tunnels in soft g...

  19. Dynamical quenching of tunneling in molecular magnets

    Energy Technology Data Exchange (ETDEWEB)

    José Santander, María, E-mail: maria.jose.noemi@gmail.com [Recursos Educativos Quántica, Santiago (Chile); Departamento de Física, Universidad de Santiago de Chile and CEDENNA, Avda. Ecuador 3493, Santiago (Chile); Nunez, Alvaro S., E-mail: alnunez@dfi.uchile.cl [Departamento de Física, Facultad de Ciencias Físicas y Matemáticas, Universidad de Chile, Casilla 487-3, Santiago (Chile); Roldán-Molina, A. [Instituto de Física, Pontificia Universidad Católica de Valparaíso, Avenida Universidad 330, Curauma, Valparaíso (Chile); Troncoso, Roberto E., E-mail: r.troncoso.c@gmail.com [Centro para el Desarrollo de la Nanociencia y la Nanotecnología, CEDENNA, Avda. Ecuador 3493, Santiago 9170124 (Chile); Departamento de Física, Universidad Técnica Federico Santa María, Avenida España 1680, Valparaíso (Chile)

    2015-12-15

    It is shown that a single molecular magnet placed in a rapidly oscillating magnetic field displays the phenomenon of quenching of tunneling processes. The results open a way to manipulate the quantum states of molecular magnets by means of radiation in the terahertz range. Our analysis separates the time evolution into slow and fast components thereby obtaining an effective theory for the slow dynamics. This effective theory presents quenching of the tunnel effect, in particular, stands out its difference with the so-called coherent destruction of tunneling. We support our prediction with numerical evidence based on an exact solution of Schrödinger's equation. - Highlights: • Single molecular magnets under rapidly oscillating magnetic fields is studied. • It is shown that this system displays the quenching of tunneling processes. • Our findings provide a control of quantum molecular magnets via terahertz radiation.

  20. A century of wind tunnels since Eiffel

    Science.gov (United States)

    Chanetz, Bruno

    2017-08-01

    Fly higher, faster, preserve the life of test pilots and passengers, many challenges faced by man since the dawn of the twentieth century, with aviation pioneers. Contemporary of the first aerial exploits, wind tunnels, artificially recreating conditions encountered during the flight, have powerfully contributed to the progress of aeronautics. But the use of wind tunnels is not limited to aviation. The research for better performance, coupled with concern for energy saving, encourages manufacturers of ground vehicles to perform aerodynamic tests. Buildings and bridge structures are also concerned. This article deals principally with the wind tunnels built at ONERA during the last century. Somme wind tunnels outside ONERA, even outside France, are also evocated when their characteristics do not exist at ONERA.

  1. Computer graphic of LHC in the tunnel

    CERN Multimedia

    1996-01-01

    A computer-generated image of the LHC particle accelerator at CERN in the tunnel originally built for the LEP accelerator that was closed in 2000. The cross-section of an LHC superconducting dipole magnet is also seen.

  2. Proton tunnelling in intermolecular hydrogen bonds

    Energy Technology Data Exchange (ETDEWEB)

    Horsewill, A.J. [Nottingham Univ. (United Kingdom); Johnson, M.R. [Institut Max von Laue - Paul Langevin (ILL), 38 - Grenoble (France); Trommsdorff, H.P. [Grenoble-1 Univ., 38 (France)

    1997-04-01

    The wavefunctions of particles extend beyond the classically accessible regions of potential energy-surfaces (PES). A manifestation of this partial delocalization is the quantum-mechanical tunneling effect which enables a particle to escape from a metastable potential-well. Tunnelling is most important for the lightest atoms, so that the determination of its contribution to proton transfer, one of the most fundamental chemical reactions, is an important issue. QENS and NMR techniques have been employed to study the motion of protons in the hydrogen bond of benzoic-acid crystals, a system which has emerged as a particularly suitable model since proton transfer occurs in a near symmetric double-well potential. The influence of quantum tunnelling was revealed and investigated in these experiments. This work provides an experimental benchmark for theoretical descriptions of translational proton-tunnelling. (author). 7 refs.

  3. LEP sees the end of the tunnel

    CERN Multimedia

    2002-01-01

    After 14 months, which have seen the removal of 30,000 tonnes of material from the tunnel, the LEP dismantling operation has now been completed. LHC installation, which will be subject to new safety rules, can go ahead.

  4. Tunneling time in space fractional quantum mechanics

    Science.gov (United States)

    Hasan, Mohammad; Mandal, Bhabani Prasad

    2018-02-01

    We calculate the time taken by a wave packet to travel through a classically forbidden region of space in space fractional quantum mechanics. We obtain the close form expression of tunneling time from a rectangular barrier by stationary phase method. We show that tunneling time depends upon the width b of the barrier for b → ∞ and therefore Hartman effect doesn't exist in space fractional quantum mechanics. Interestingly we found that the tunneling time monotonically reduces with increasing b. The tunneling time is smaller in space fractional quantum mechanics as compared to the case of standard quantum mechanics. We recover the Hartman effect of standard quantum mechanics as a special case of space fractional quantum mechanics.

  5. Prevention and Control of Highway Tunnel Fires

    Science.gov (United States)

    1984-05-01

    This study investigates steps that can be taken to reduce the risk, damage, and : fatalities from fires in existing and future highway tunnels and the effect of : unrestricted transit of hazardous materials through them. The history of : highway tunn...

  6. 7 x 10 Foot Wind Tunnel

    Data.gov (United States)

    Federal Laboratory Consortium — This wind tunnel is used for basic and applied research in aeromechanics on advanced and unique technology rotorcraft. It supports research on advanced concepts and...

  7. SOFIA: Aft cavities wind tunnel test

    Science.gov (United States)

    1994-01-01

    This appendix to the final report of SOFIA 2 is a collection of configuration photos of the wind tunnel test and a brief description of each for the Stratospheric Observatory for Infrared Astronomy (SOFIA).

  8. Computational Analysis of Protein Tunnels and Channels.

    Science.gov (United States)

    Brezovsky, Jan; Kozlikova, Barbora; Damborsky, Jiri

    2018-01-01

    Protein tunnels connecting the functional buried cavities with bulk solvent and protein channels, enabling the transport through biological membranes, represent the structural features that govern the exchange rates of ligands, ions, and water solvent. Tunnels and channels are present in a vast number of known proteins and provide control over their function. Modification of these structural features by protein engineering frequently provides proteins with improved properties. Here we present a detailed computational protocol employing the CAVER software that is applicable for: (1) the analysis of tunnels and channels in protein structures, and (2) the selection of hot-spot residues in tunnels or channels that can be mutagenized for improved activity, specificity, enantioselectivity, or stability.

  9. Tunnels Used in Community School Plan

    Science.gov (United States)

    School Management, 1972

    1972-01-01

    In a Springfield, Massachusetts, school design, tunnels housing community facilities will make it possible to utilize otherwise unusable land and will create neighborhood ties in an area undergoing urban renewal. (Author)

  10. Dielectric Sensors Based on Electromagnetic Energy Tunneling

    Directory of Open Access Journals (Sweden)

    Omar Siddiqui

    2015-03-01

    Full Text Available We show that metallic wires embedded in narrow waveguide bends and channels demonstrate resonance behavior at specific frequencies. The electromagnetic energy at these resonances tunnels through the narrow waveguide channels with almost no propagation losses. Under the tunneling behavior, high-intensity electromagnetic fields are produced in the vicinity of the metallic wires. These intense field resonances can be exploited to build highly sensitive dielectric sensors. The sensor operation is explained with the help of full-wave simulations. A practical setup consisting of a 3D waveguide bend is presented to experimentally observe the tunneling phenomenon. The tunneling frequency is predicted by determining the input impedance minima through a variational formula based on the Green function of a probe-excited parallel plate waveguide.

  11. The CRREL South Pole tunneling system

    National Research Council Canada - National Science Library

    Walsh, Michael R

    1999-01-01

    .... Army Cold Regions Research and Engineering Laboratory initiated a project to design, develop, fabricate, test, build, and deploy a system for the machining of unlined tunnels at the Amundsen-Scott South Pole Station...

  12. Low Speed Wind Tunnel Facility (LSWTF)

    Data.gov (United States)

    Federal Laboratory Consortium — Description: This facility consists of a large-scale, low-speed open-loop induction wind tunnel which has been modified to house a linear turbine cascade. A 125-hp...

  13. Geology of Pletovarje motorway tunnel (Slovenia

    Directory of Open Access Journals (Sweden)

    Magda Čarman

    2009-06-01

    Full Text Available Styrian motorway crosses the Pletovarje ridge through the tunnel having the same name. It intersects the mosteastern extension of the Southern Karavanke tectonic unit. Considering geological conditions, the tunnel couldbe divided into three sections: the inner Donat / Dona~ka fault zone composed of tectonic lenses of differentlithostratigraphic units (of paleozoic, triassic and tertiary age, massive dolomite (lower triassic and Smrekovecseries of oligocene age. Main faults have east – west direction and are subvertical.

  14. Cubital Tunnel Syndrome, Associated With Synovial Chondromatosis

    Science.gov (United States)

    Kim, Chang-Hwan; Kim, Min-Soo; Chang, Chul-Hoon

    2008-01-01

    A 62-year-old female patient suffered from numbness and resting pain in the right ring and little fingers for 3 years. We confirmed cubital tunnel syndrome with electrodiagnostic study and performed the operation. We found seven firm consistent nodules, compressing the overlying the ulnar nerve, proximal to the medial epicondyle in the operation field. Histological finding showed synovial chondromatosis. We report a rare case of a patient with cubital tunnel syndrome caused by synovial chondromatosis. PMID:19096614

  15. Automatic control of cryogenic wind tunnels

    Science.gov (United States)

    Balakrishna, S.

    1989-01-01

    Inadequate Reynolds number similarity in testing of scaled models affects the quality of aerodynamic data from wind tunnels. This is due to scale effects of boundary-layer shock wave interaction which is likely to be severe at transonic speeds. The idea of operation of wind tunnels using test gas cooled to cryogenic temperatures has yielded a quantrum jump in the ability to realize full scale Reynolds number flow similarity in small transonic tunnels. In such tunnels, the basic flow control problem consists of obtaining and maintaining the desired test section flow parameters. Mach number, Reynolds number, and dynamic pressure are the three flow parameters that are usually required to be kept constant during the period of model aerodynamic data acquisition. The series of activity involved in modeling, control law development, mechanization of the control laws on a microcomputer, and the performance of a globally stable automatic control system for the 0.3-m Transonic Cryogenic Tunnel (TCT) are discussed. A lumped multi-variable nonlinear dynamic model of the cryogenic tunnel, generation of a set of linear control laws for small perturbation, and nonlinear control strategy for large set point changes including tunnel trajectory control are described. The details of mechanization of the control laws on a 16 bit microcomputer system, the software features, operator interface, the display and safety are discussed. The controller is shown to provide globally stable and reliable temperature control to + or - 0.2 K, pressure to + or - 0.07 psi and Mach number to + or - 0.002 of the set point value. This performance is obtained both during large set point commands as for a tunnel cooldown, and during aerodynamic data acquisition with intrusive activity like geometrical changes in the test section such as angle of attack changes, drag rake movements, wall adaptation and sidewall boundary-layer removal. Feasibility of the use of an automatic Reynolds number control mode with

  16. Probing electronic interactions using electron tunneling

    Indian Academy of Sciences (India)

    pratap

    Tunneling In the particle language. The fraction of particle tunneling falls rapidly with the width and height of the barrier. Need to have available states at the ... Order-disorder transition of a vortex lattice. 2.0 2.5 3.0 3.5 4.0 4.5 5.0. 0. 5. 10. 15. 20. 25. 30. 35. H p. H c2. T (K). H (kO e). Ordered state. Disordered state. 0. 10. 20.

  17. General risks for tunnelling projects: An overview

    Science.gov (United States)

    Siang, Lee Yong; Ghazali, Farid E. Mohamed; Zainun, Noor Yasmin; Ali, Roslinda

    2017-10-01

    Tunnels are indispensable when installing new infrastructure as well as when enhancing the quality of existing urban living due to their unique characteristics and potential applications. Over the past few decades, there has been a significant increase in the building of tunnels, world-wide. Tunnelling projects are complex endeavors, and risk assessment for tunnelling projects is likewise a complex process. Risk events are often interrelated. Occurrence of a technical risk usually carries cost and schedule consequences. Schedule risks typically impact cost escalation and project overhead. One must carefully consider the likelihood of a risk's occurrence and its impact in the context of a specific set of project conditions and circumstances. A project's goals, organization, and environment impacts in the context of a specific set of project conditions and circumstances. Some projects are primarily schedule driven; other projects are primarily cost or quality driven. Whether a specific risk event is perceived fundamentally as a cost risk or a schedule risk is governed by the project-specific context. Many researchers have pointed out the significance of recognition and control of the complexity, and risks of tunnelling projects. Although all general information on a project such as estimated duration, estimated cost, and stakeholders can be obtained, it is still quite difficult to accurately understand, predict and control the overall situation and development trends of the project, leading to the risks of tunnelling projects. This paper reviews all the key risks for tunnelling projects from several case studies that have been carried out by other researchers. These risks have been identified and reviewed in this paper. As a result, the current risk management plan in tunnelling projects can be enhanced by including all these reviewed risks as key information.

  18. The Femarnbelt Tunnel: Regional Development Perspectives

    DEFF Research Database (Denmark)

    Matthiessen, Christian Wichmann; Lundhus, Peter

    2011-01-01

    structures (bridges/ tunnels) spanning international waterways. They concentrate traffic flows and create strong transport corridors and are the basis of new regional development regimes. In early 2011, following almost two years of extensive work on different conceptual designs for the fixed link...... it was decided that an immersed tunnel should form the basis for the continuous planning of the project, including the environmental impact studies. Completion of the link is scheduled for 2020...

  19. Numerical modeling of tunneling-induced seismicity

    Science.gov (United States)

    Rinaldi, Antonio Pio; Urpi, Luca

    2017-04-01

    Removal of rock mass in mining environment has been associated since long-time with seismic event of magnitude 3 and above, with the potential to cause damage to the infrastructures or even loss of human life. Although with similarities with mining, relatively unknown up to now are seismic events induced by tunneling. However with modern mechanized tunneling techniques, making possible to digging deeper and longer underground infrastructure, the risk is not negligible. As an example, the excavation of the 57km long Gotthard Base Tunnel has been associated more than hundred seismic events, with the largest one having magnitude of ML 2.4, damaging the tunnel infrastructures. For future scenario of deep geological storage of nuclear waste, tunneling will constitute the primary activity during site construction. Hence, it will be crucial to understand the risk associated with the underground construction operation that can reactivate seismogenic features nearby the future location of emplacement tunnels. Here we present numerical simulation aimed at understanding the potential for inducing seismicity during tunnel construction. The stress changes and their evolution during the excavation are evaluated with a finite element solver (FLAC3d). A strain-softening friction model is then used to simulate the occurrence of a sudden slip on a fault zone (if critical conditions for reactivation are reached). We also present a sensitivity analysis of the potential for inducing different seismic events by different tunnel sizes at varying distance from a nearby failure plane, with the final purpose of evaluating safety of a potential nuclear repository site on the short- and long-term.

  20. Work on a transfer tunnel access shaft

    CERN Multimedia

    Laurent Guiraud

    2000-01-01

    Civil engineers work on one of the access shafts from the SPS to the LHC transfer tunnel, which will allow components and equipment to be lowered directly so that minimal transport is required. The transfer tunnel will take a proton beam from the SPS pre-accelerator and inject it into the clockwise circulating ring in the LHC where the beam will be accelerated to a final energy of 7 TeV.

  1. Scanning Tunneling Spectroscopy of Graphene on Graphite

    OpenAIRE

    Li, Guohong; Luican, Adina; Andrei, Eva Y.

    2008-01-01

    We report low temperature high magnetic field scanning tunneling microscopy and spectroscopy of graphene flakes on graphite that exhibit the structural and electronic properties of graphene decoupled from the substrate. Pronounced peaks in the tunneling spectra develop with field revealing a Landau level sequence that provides a direct way to identify graphene and to determine the degree of its coupling to the substrate. The Fermi velocity and quasiparticle lifetime, obtained from the positio...

  2. Nonlinear earthquake behaviour of highway tunnels

    Directory of Open Access Journals (Sweden)

    B. Sevim

    2011-10-01

    Full Text Available This paper describes the Arhavi Highway Tunnel which has two tubes, its geometrical properties, finite element model, and the nonlinear earthquake behaviour under a huge ground motion considering soil-structure interaction. The Arhavi Highway Tunnel is one of the tallest tunnels constructed in the Black Sea region of Turkey as part of the Coast Road Project. The tunnel has two tubes and each of them is about 1000 m tall. In the study, the modal analyses of the tunnel considering soil-structure interaction are performed and natural frequencies and mode shapes are obtained. Then, nonlinear transient analysis of the tunnel using Drucker-Prager criteria is performed applying acceleration components of 1992 Erzincan, Turkey earthquake's ground motion. In the time history analyses, Rayleigh damping coefficients are calculated using main natural frequency obtained from modal analysis. Element matrices are computed using the Gauss numerical integration technique. The Newmark method is used in the solution of the equation of motion. Because too much memory for the analyses is required, the first 7.5 s of the ground motions, which is the most effective duration, is taken into account in calculations. The displacement and stress results are observed to be the allowable level of the concrete material.

  3. Bronchitis - acute

    Science.gov (United States)

    ... sharing features on this page, please enable JavaScript. Acute bronchitis is swelling and inflamed tissue in the main ... present only for a short time. Causes When acute bronchitis occurs, it almost always comes after having a ...

  4. Acute cholecystitis

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/article/000264.htm Acute cholecystitis To use the sharing features on this page, please enable JavaScript. Acute cholecystitis is sudden swelling and irritation of the gallbladder. ...

  5. Some Caves in tunnels in Dinaric karst of Croatia

    Science.gov (United States)

    Garasic, Mladen; Garasic, Davor

    2016-04-01

    In the last 50 years during the construction of almost all the tunnels in the Croatian Dinaric Karst thousands of caves have been encountered that represented the major problems during the construction works. Geological features (fissures, folding, faults, etc.) are described in this contribution, together with the hydrogeological conditions (rapid changes in groundwater levels). Special engineering geological exploration and survey of each cave, together with the stabilization of the tunnel ceiling, and groundwater protection actions according to basic engineering geological parameters are also presented. In karst tunneling in Croatia over 150 caves longer than 500 m have been investigated. Several caves are over 300 m deep (St. Ilija tunnel in Biokovo Mt), and 10 are longer than 1000 m (St.Rok tunnel, HE Senj and HE Velebit tunnels in Velebit Mt, Ucka tunnel in Ucka Mt, Mala kapela tunnel in Kapela Mt, caverns in HE Plat tunnel etc). Different solutions were chosen to cross the caves depending on the size and purpose of the tunnels (road, rail, pedestrian tunnel, or hydrotechnical tunnels). This is presentations of interesting examples of ceiling stabilization in big cave chambers, construction of bridges inside tunnels, deviations of tunnels, filling caves, grouting, etc. A complex type of karstification has been found in the cavern at the contact between the Palaeozoic clastic impervious formations and the Mesozoic complex of dolomitic limestones in the Vrata Tunnel and at the contact with flysch in the Učka Tunnel. However, karstification advancing in all directions at a similar rate is quite rare. The need to have the roadway and/or tunnel above water from a spring is the biggest possible engineering-geological, hydrogeological and civil engineering challenge. Significant examples are those above the Jadro spring (Mravinci tunnel) in flysch materials or above the Zvir spring in Rijeka (Katarina tunnel), and in fractured Mesozoic carbonates. Today in Croatian

  6. Le LHC, un tunnel cosmique

    CERN Multimedia

    CERN. Geneva

    2009-01-01

    Et si la lumière au bout du tunnel du LHC était cosmique ? En d’autres termes, qu’est-ce que le LHC peut nous apporter dans la connaissance de l’Univers ? Car la montée en énergie des accélérateurs de particules nous permet de mieux appréhender l’univers primordial, chaud et dense. Mais dans quel sens dit-on que le LHC reproduit des conditions proches du Big bang ? Quelles informations nous apporte-t-il sur le contenu de l’Univers ? La matière noire est-elle détectable au LHC ? L’énergie noire ? Pourquoi l’antimatière accumulée au CERN est-elle si rare dans l’Univers ? Et si le CERN a bâti sa réputation sur l’exploration des forces faibles et fortes qui opèrent au sein des atomes et de leurs noyaux, est-ce que le LHC peut nous apporter des informations sur la force gravitationnelle qui gouverne l’évolution cosmique ? Depuis une trentaine d’années, notre compréhension de l’univers dans ses plus grandes dimensions et l’appréhension de son comportement aux plus peti...

  7. Tunneling and Transport in Nanowires

    Energy Technology Data Exchange (ETDEWEB)

    Goldman, Allen M. [Univ. of Minnesota, Minneapolis, MN (United States)

    2016-08-16

    The goal of this program was to study new physical phenomena that might be relevant to the performance of conductive devices and circuits of the smallest realizable feature sizes possible using physical rather than biological techniques. Although the initial scientific work supported involved the use of scanning tunneling microscopy and spectroscopy to ascertain the statistics of the energy level distribution of randomly sized and randomly shaped quantum dots, or nano-crystals, the main focus was on the investigation of selected properties, including superconductivity, of conducting and superconducting nanowires prepared using electron-beam-lithography. We discovered a magnetic-field-restoration of superconductivity in out-of-equilibrium nanowires driven resistive by current. This phenomenon was explained by the existence of a state in which dissipation coexisted with nonvanishing superconducting order. We also produced ultra-small superconducting loops to study a predicted anomalous fluxoid quantization, but instead, found a magnetic-field-dependent, high-resistance state, rather than superconductivity. Finally, we developed a simple and controllable nanowire in an induced charged layer near the surface of a masked single-crystal insulator, SrTiO3. The layer was induced using an electric double layer transistor employing an ionic liquid (IL). The transport properties of the induced nanowire resembled those of collective electronic transport through an array of quantum dots.

  8. Organic tunnel field effect transistors

    KAUST Repository

    Tietze, Max Lutz

    2017-06-29

    Various examples are provided for organic tunnel field effect transistors (OTFET), and methods thereof. In one example, an OTFET includes a first intrinsic layer (i-layer) of organic semiconductor material disposed over a gate insulating layer; source (or drain) contact stacks disposed on portions of the first i-layer; a second i-layer of organic semiconductor material disposed on the first i-layer surrounding the source (or drain) contact stacks; an n-doped organic semiconductor layer disposed on the second i-layer; and a drain (or source) contact layer disposed on the n-doped organic semiconductor layer. The source (or drain) contact stacks can include a p-doped injection layer, a source (or drain) contact layer, and a contact insulating layer. In another example, a method includes disposing a first i-layer over a gate insulating layer; forming source or drain contact stacks; and disposing a second i-layer, an n-doped organic semiconductor layer, and a drain or source contact.

  9. Validation of a Compact Isokinetic Total Water Content Probe for Wind Tunnel Characterization at NASA Glenn Icing Research Tunnel and at NRC Ice Crystal Tunnel

    Science.gov (United States)

    Davison, Craig R.; Landreville, Charles; Ratvasky, Thomas P.

    2017-01-01

    A new compact isokinetic probe to measure total water content in a wind tunnel environment has been developed. The probe has been previously tested under altitude conditions. This paper presents a comprehensive validation of the probe under a range of liquid water conditions at sea level in the NASA Glenn Icing Research Tunnel and with ice crystals at sea level at the NRC wind tunnel. The compact isokinetic probe is compared to tunnel calibrations and other probes.

  10. OPERATIONAL AND MAINTENANCE FEATURES OF THE SV. TRI KRALJA TUNNEL

    Directory of Open Access Journals (Sweden)

    Zvonimir Deković

    2013-12-01

    Full Text Available The paper focuses on the features of the operation and maintenance of tunnels on the Zagreb-Macelj motorway. When it comes to the operation and maintenance of a series of six tunnels on the Zagreb-Macelj motorway, Sv. Tri Kralja Tunnel is the most challenging structure on the motorway, where it is necessary to provide an adequate level of safety and operability. Tunnel operation is ensured by the concession model of public - private partnership, which is applied to the Zagreb – Macelj motorway. Features of the tunnel infrastructure maintenance are emphasized, as well as importance of the extraordinary maintenance of the tunnel infrastructure. The goal of the tunnel operation and maintenance is to ensure undisturbed and safe traffic flow through the tunnels, by keeping the tunnel in normal functional conditions.

  11. Quantum dot resonant tunneling diode single photon detector with aluminum oxide aperture defined tunneling area

    DEFF Research Database (Denmark)

    Li, H.W.; Kardynal, Beata; Ellis, D.J.P.

    2008-01-01

    Quantum dot resonant tunneling diode single photon detector with independently defined absorption and sensing areas is demonstrated. The device, in which the tunneling is constricted to an aperture in an insulating layer in the emitter, shows electrical characteristics typical of high quality res...

  12. Tunnelling in Soft Soil : Tunnel Boring Machine Operation and Soil Response

    NARCIS (Netherlands)

    Festa, D.; Broere, W.; Bosch, J.W.

    Constructing tunnels in soft soil with the use of Tunnel Boring Machines may induce settlements including soil movements ahead of the face, soil relaxation into the tail void, possible heave due to grouting, long lasting consolidation processes, and potentially several other mechanisms. A

  13. Does flexible tunnel drilling affect the femoral tunnel angle measurement after anterior cruciate ligament reconstruction?

    Science.gov (United States)

    Muller, Bart; Hofbauer, Marcus; Atte, Akere; van Dijk, C Niek; Fu, Freddie H

    2015-12-01

    To quantify the mean difference in femoral tunnel angle (FTA) as measured on knee radiographs between rigid and flexible tunnel drilling after anatomic anterior cruciate ligament (ACL) reconstruction. Fifty consecutive patients that underwent primary anatomic ACL reconstruction with a single femoral tunnel drilled with a flexible reamer were included in this study. The control group was comprised of 50 patients all of who underwent primary anatomic ACL reconstruction with a single femoral tunnel drilled with a rigid reamer. All femoral tunnels were drilled through a medial portal to ensure anatomic tunnel placement. The FTA was determined from post-operative anterior-to-posterior (AP) radiographs by two independent observers. A 5° difference between the two mean FTA was considered clinically significant. The average FTA, when drilled with a rigid reamer, was 42.0° ± 7.2°. Drilling with a flexible reamer resulted in a mean FTA of 44.7° ± 7.0°. The mean difference of 2.7° was not statistically significant. The intraclass correlation coefficient for inter-tester reliability was 0.895. The FTA can be reliably determined from post-operative AP radiographs and provides a useful and reproducible metric for characterizing femoral tunnel position after both rigid and flexible femoral tunnel drilling. This has implications for post-operative evaluation and preoperative treatment planning for ACL revision surgery. IV.

  14. Does flexible tunnel drilling affect the femoral tunnel angle measurement after anterior cruciate ligament reconstruction?

    NARCIS (Netherlands)

    Muller, Bart; Hofbauer, Marcus; Atte, Akere; van Dijk, C. Niek; Fu, Freddie H.

    2015-01-01

    To quantify the mean difference in femoral tunnel angle (FTA) as measured on knee radiographs between rigid and flexible tunnel drilling after anatomic anterior cruciate ligament (ACL) reconstruction. Fifty consecutive patients that underwent primary anatomic ACL reconstruction with a single femoral

  15. Airborne asbestos fibres monitoring in tunnel excavation.

    Science.gov (United States)

    Gaggero, Laura; Sanguineti, Elisa; Yus González, Adrián; Militello, Gaia Maria; Scuderi, Alberto; Parisi, Giovanni

    2017-07-01

    Tunnelling across ophiolitic formation with Naturally Occurring Asbestos (NOA) can release fibres into the environment, exposing workers, and the population, if fibres spread outside the tunnel, leading to increased risk of developing asbestos-related disease. Therefore, a careful plan of environmental monitoring is carried out during Terzo Valico tunnel excavation. In the present study, data of 1571 samples of airborne dust, collected between 2014 and 2016 inside the tunnels, and analyzed by SEM-EDS for quantification of workers exposure, are discussed. In particular, the engineering and monitoring management of 100 m tunnelling excavation across a serpentinite lens (Cravasco adit), intercalated within calcschists, is reported. At this chrysotile occurrence, 84% of 128 analyzed samples (from the zone closer to the front rock) were above 2 ff/l. However, thanks to safety measures implemented and tunnel compartmentation in zones, the asbestos fibre concentration did not exceed the Italian standard of occupational exposure (100 ff/l) and 100% of samples collected in the outdoor square were below 1 ff/l. During excavation under normal working conditions, asbestos concentrations were below 2 ff/l in 97.4% of the 668 analyzed samples. Our results showed that air monitoring can objectively confirm the presence of asbestos minerals at a rock front in relative short time and provide information about the nature of the lithology at the front. The present dataset, the engineering measures described and the operative conclusions are liable to support the improvement of legislation on workers exposure to asbestos referred to the tunnelling sector, lacking at present. Copyright © 2017 Elsevier Ltd. All rights reserved.

  16. From the history of settling networks of tunnels (On the 100. anniversary of the Simplonsky tunnel

    Directory of Open Access Journals (Sweden)

    Pavel Hánek

    2007-06-01

    Full Text Available The present contribution entitled „History of setting-out network of tunnels“ is dedicated to the 100th anniversary of the opening of Simplon’s tunnel. Tunnels belong to the most significant civil engineering works which closely reflect the technical and social scale of the epoch of their genesis. Necessary conditions of the successful planing and constructions of tunnels are geodetically ensured location and building procedures. This presentation traces the progress of the setting out networks of European tunnels from earliest times (the Samos Island, the 6th century B.C. to the present days when the GPS methods are used. It focuses upon data concerning the alpine tunnels of the 19th and 20th centuries and follows earlier articles by the same author.

  17. Principles of tunneled cuffed catheter placement.

    Science.gov (United States)

    Heberlein, Wolf

    2011-12-01

    Tunneled cuffed catheters provide reliable and instant long-term intravenous access for a large variety of therapeutic purposes, including chemotherapy, parenteral nutrition, and apheresis. The most frequent application is for patients with renal failure as an access device for hemodialysis. In this capacity, the rate of catheter use has remained stable in the United States, despite the promotion of arteriovenous fistulas and arteriovenous grafts. The latter 2 procedures achieve superior longevity and much higher cost-efficiency. Tunneled catheters, however, serve as bridging devices during maturation of newly placed arteriovenous fistulas or as the final option in patients in whom fistulas and grafts have failed. High-quality vascular access is a hallmark of interventional radiology, and its significance for patient care and for our specialty cannot be overestimated. Familiarity with basic concepts of the device and procedural techniques are crucial to achieve successful long-term venous access. The following article demonstrates key concepts of tunneled venous catheter placement by means of dialysis, inasmuch as dialysis catheters represent the most commonly placed tunneled central venous catheters. The principles of placement and techniques utilized, however, are applicable to devices that are used for chemotherapy or parenteral nutrition, such as the Hickman, Broviac, Groshong, or tunneled peripherally inserted central catheters. Copyright © 2011 Elsevier Inc. All rights reserved.

  18. Complex use of heat-exchange tunnels

    Directory of Open Access Journals (Sweden)

    А. Ф. Галкин

    2017-04-01

    Full Text Available The paper presents separate results of complex research (experimental and theoretical on the application of heat-exchange tunnels – in frozen rocks, among other things – as underground constructions serving two purposes. It is proposed to use heat-exchange tunnels as a separate multi-functional module, which under normal conditions will be used to set standards of heat regime parameters in the mines, and in emergency situations, natural or man-made, will serve as a protective structure to shelter mine workers. Heat-exchange modules can be made from mined-out or specially constructed tunnels. Economic analysis shows that the use of such multi-functional modules does not increase operation and maintenance costs, but enhances safety of mining operations and reliability in case of emergency situations. There are numerous theoretic and experimental investigations in the field of complex use of mining tunnels, which allows to develop regulatory design documents on their basis. Experience of practical application of heat-exchange tunnels has been assessed from the position of regulating heat regime in the mines.

  19. Acute Porphyrias.

    Science.gov (United States)

    Besur, Siddesh; Schmeltzer, Paul; Bonkovsky, Herbert L

    2015-09-01

    Porphyrias are a group of eight metabolic disorders characterized by defects in heme biosynthesis. Porphyrias are classified into two major categories: 1) the acute or inducible porphyrias and 2) the chronic cutaneous porphyrias. The acute hepatic porphyrias are further classified into acute intermittent porphyria (AIP), hereditary coproporphyria, variegate porphyria, and porphyria due to severe deficiency of delta-aminolevulinic acid (ALA) dehydratase (ALADP). AIP is the most common, and ALADP is the least common acute porphyria. The clinical presentations of acute porphyrias are nonspecific. There are no pathognomonic signs or symptoms. The most frequent presenting symptom is abdominal pain, but pain in the chest, back, or lower extremities may also occur. Hyponatremia is the most common electrolyte abnormality during acute attacks, and hypomagnesemia is also common. Both are risk factors for development of seizures, which occur in ∼ 20-30% of acute attacks. Once suspected, the diagnosis of porphyria can be rapidly established by checking random urinary porphobilinogen. Initial management of acute porphyria includes discontinuation of all potentially harmful drugs and management of symptoms. Acute attacks should be treated emergently with intravenous heme and glucose to avoid considerable morbidity and mortality. Acute attacks last a few days, and the majority of patients are asymptomatic between attacks. Prognosis is good if the condition is recognized early and treated aggressively. Copyright © 2015 Elsevier Inc. All rights reserved.

  20. Quantitative MRI analysis of idiopathic carpal tunnel syndrome.

    Science.gov (United States)

    Oge, Halil Kamil; Acu, Berat; Gucer, Tacettin; Yanik, Tugra; Savlarli, Safak; Firat, Mehmet Murat

    2012-01-01

    The aim of this study was to try to find parametric ratios for the diagnosis and pathophysiology of carpal tunnel syndrome using MR. Dominant side wrist MRI examinations of 27 female carpal tunnel patients and 21 normal females were compared. The carpal tunnel contents area / carpal tunnel cross section area ratio was defined, analysed and discussed with the literature. Carpal tunnel contents / wrist area ratios of the carpal tunnel patients were measured and compared with the control group. This comparison revealed that the proportion of the contents of the carpal tunnel is increased in the carpal tunnel syndrome patients. Palmar bowing was found to be increased and median nerve cross section area was found to be increased at the proximal entrance of the carpal tunnel. As Phalen has postulated, the volume of the contents of the carpal tunnel were found to be increased in the carpal tunnel syndrome patients. Carpal tunnel cross section areas remained the same with the control group. This increase can be demonstrated by MRI imaging which can provide an evidence for the pathophysiology of carpal tunnel syndrome.

  1. Overview of traffic safety aspects and design in road tunnels

    Directory of Open Access Journals (Sweden)

    Shy Bassan

    2016-07-01

    Drivers in road tunnels generally reduce their speed and increase their lateral position from the right tunnel wall while driving. In shorter tunnels, with reduced driving speed, driver vigilance may be more robust without being hindered by dull driving, which is more common in longer tunnels. Still, in spite of driver alertness, crash rates in tunnels occur due to the tunnel's unusual driving environment. Crash rates are lower in the tunnel inner zone due to driver alertness, especially after passing the transition zone and acclimating to the tunnel environment. The number of crashes, however, is higher along zone 4 (tunnel inner zone, which is the principal zone, as it covers longer driving distance. According to most studies, short tunnels were found to exhibit higher crash rates than long tunnels because the entrance zones incorporate higher crash rates, compared with the midzones; nonetheless, longer unidirectional (freeway and multilane tunnels with higher design speed, entail lower driver alertness and diminished concentration due to relatively monotonous driving in spite of a tunnel's closed environment.

  2. Influence of knee flexion angle and transverse drill angle on creation of femoral tunnels in double-bundle anterior cruciate ligament reconstruction using the transportal technique: Three-dimensional computed tomography simulation analysis.

    Science.gov (United States)

    Choi, Chong Hyuk; Kim, Sung-Jae; Chun, Yong-Min; Kim, Sung-Hwan; Lee, Su-Keon; Eom, Nam-Kyu; Jung, Min

    2018-01-01

    The purpose of this study was to find appropriate flexion angle and transverse drill angle for optimal femoral tunnels of anteromedial (AM) bundle and posterolateral (PL) bundle in double-bundle ACL reconstruction using transportal technique. Thirty three-dimensional knee models were reconstructed. Knee flexion angles were altered from 100° to 130° at intervals of 10°. Maximum transverse drill angle (MTA), MTA minus 10° and 20° were set up. Twelve different tunnels were determined by four flexion angles and three transverse drill angles for each bundle. Tunnel length, wall breakage, inter-tunnel communication and graft-bending angle were assessed. Mean tunnel length of AM bundle was >30mm at 120° and 130° of flexion in all transverse drill angles. Mean tunnel length of PL bundle was >30mm during every condition. There were ≥1 cases of wall breakage except at 120° and 130° of flexion with MTA for AM bundle. There was no case of wall breakage for PL bundle. Considering inter-tunnel gap of >2mm without communication and obtuse graft-bending angle, 120° of flexion and MTA could be recommended as optimal condition for femoral tunnels of AM and PL bundles. Flexion angle and transverse drill angle had combined effect on femoral tunnel in double-bundle ACL reconstruction using transportal technique. Achieving flexion angle of 120° and transverse drill angle close to the medial femoral condyle could be recommended as optimal condition for femoral tunnels of AM and PL bundles to avoid insufficient tunnel length, wall breakage, inter-tunnel communication and acute graft-bending angle. Copyright © 2017 Elsevier B.V. All rights reserved.

  3. Positioning systems for underground tunnel environments

    CERN Document Server

    Leite Pereira, Fernando; Theis, Christian

    In the last years the world has witnessed a remarkable change in the computing concept by entering the mobile era. Incredibly powerful smartphones have proliferated at stunning pace and tablet computers are capable of running demanding applications and meet new business requirements. Being wireless, localization has become crucial not only to serve individuals but also help companies in industrial and safety processes. In the context of the Radiation Protection group at CERN, automatic localization, besides allowing to find people, would help improving the radiation surveys performed regularly along the accelerator tunnels. The research presented in this thesis attempts to answer questions relatively to the viability of localization in a harsh conditions tunnel: “Is localization in a very long tunnel possible, meeting its restrictions and without incurring prohibitive costs and infrastructure?”, “Can one achieve meter-level accuracy with GSM deployed over leaky-feeder?”, “Is it possible to prototype...

  4. Phonon tunneling through a double barrier system

    Energy Technology Data Exchange (ETDEWEB)

    Villegas, Diosdado [Departamento de Física, Universidad Central “Marta Abreu” de Las Villas, CP 54830, Santa Clara, Villa Clara (Cuba); Instituto de Física, Universidad Autónoma de Puebla, 18 Sur y San Claudio, Edif. 110A, Ciudad Universitaria, 72570 Puebla (Mexico); León-Pérez, Fernando de [Centro Universitario de la Defensa de Zaragoza, Ctra. de Huesca s/n, E-50090 Zaragoza (Spain); Pérez-Álvarez, R. [Universidad Autónoma del Estado de Morelos, Av. Universidad 1001, CP 62209 Cuernavaca (Mexico); Arriaga, J., E-mail: arriaga@ifuap.buap.mx [Instituto de Física, Universidad Autónoma de Puebla, 18 Sur y San Claudio, Edif. 110A, Ciudad Universitaria, 72570 Puebla (Mexico)

    2015-04-15

    The tunneling of optical and acoustic phonons at normal incidence on a double-barrier is studied in this paper. Transmission coefficients and resonance conditions are derived theoretically under the assumption that the long-wavelength approximation is valid. It is shown that the behavior of the transmission coefficients for the symmetric double barrier has a Lorentzian form close to resonant frequencies and that Breit–Wigner's formula have a general validity in one-dimensional phonon tunneling. Authors also study the so-called generalized Hartman effect in the tunneling of long-wavelength phonons and show that this effect is a numerical artifact resulting from taking the opaque limit before exploring the variation with a finite barrier width. This study could be useful for the design of acoustic devices.

  5. Spin-polarized scanning tunnelling microscopy

    CERN Document Server

    Bode, M

    2003-01-01

    The recent experimental progress in spin-polarized scanning tunnelling microscopy (SP-STM) - a magnetically sensitive imaging technique with ultra-high resolution - is reviewed. The basics of spin-polarized electron tunnelling are introduced as they have been investigated in planar tunnel junctions for different electrode materials, i.e. superconductors, optically excited GaAs, and ferromagnets. It is shown that ferromagnets and antiferromagnets are suitable tip materials for the realization of SP-STM. Possible tip designs and modes of operations are discussed for both classes of materials. The results of recent spatially resolved measurements as performed with different magnetic probe tips and using different modes of operation are reviewed and discussed in terms of applicability to surfaces, thin films, and nanoparticles. The limits of spatial resolution, and the impact of an external magnetic field on the imaging process.

  6. Particle and chemical control using tunnel flow

    Science.gov (United States)

    Chilese, Frank; Delgado, Gildardo R.; Wack, Daniel; Torczynski, John R.

    2017-09-12

    An apparatus for contaminant control, having: a first optical assembly including: a first light homogenizer tunnel with: a first end connected to an extreme ultra-violet light source, a second end in communication with a destination chamber, a first enclosed space, and, a first gas input arranged to introduce a first gas such that the first gas flows in a first direction toward the first end and in a second direction toward the second end. The apparatus alternately having: a second optical assembly including: a second light homogenizer tunnel with: a third end connected to an extreme ultra-violet light source, a fourth end in communication with a destination chamber, a second enclosed space, a diffusion barrier tube including: a fifth end facing the fourth end and a sixth end in communication with a destination chamber, and a second gas input between the second light homogenizer tunnel and the diffusion tube.

  7. Time in dissipative tunneling: Subtleties and applications

    Science.gov (United States)

    Kelkar, N. G.; Lozano Gómez, D.; Patiño, Edgar J.

    2017-07-01

    Characteristic features of tunneling times for dissipative tunneling of a particle through a rectangular barrier are studied within a semiclassical model involving dissipation in the form of a velocity dependent frictional force. The average dwell time and traversal time with dissipation are found to be less than those without dissipation. This counter-intuitive behavior is reversed if one evaluates the physically relevant transmission dwell time. Apart from these observations, we find that the percentage of energy lost by the tunneling particle is higher for smaller energies. The above observations are tested and confirmed in a realistic case by applying the dissipation model to study the current-voltage data in a Al/Al2O3/Al solid state junction at various temperatures. The friction coefficient for Al2O3 as a function of temperature is presented. It is found to decrease with increasing temperature.

  8. Probing the surface chemistry of polycrystalline ZnO with scanning tunneling microscopy and tunneling spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Rohrer, G.S.; Bonnell, D.A. (Univ. of Pennsylvania, Philadelphia (United States))

    This paper describes the use of scanning tunneling microscopy and spatially resolved tunneling spectroscopy to examine polycrystalline ZnO surface in ultrahigh vacuum after bake-out, after a low temperature anneal that cleaned the surface, after a high temperature anneal, which segregated bismuth to the surface, after being dosed with O{sub 2} and H{sub 2}O, and after exposure to air. The tunneling spectra depend both on the proximity to structural features, such as grain boundaries, and on the chemical composition of the surface. For example, the segregation of bismuth to the surface causes the tunneling spectra to have a p-type rectification. Our results also indicate that the rectification of tunneling spectra acquired in air is caused by surface hydration and that images of surfaces that have not been heated in vacuum have inferior resolution due to a reduction in the height of the apparent tunnel barrier. Spatially resolved tunneling spectroscopy has been used to demonstrate that surface hydration has a greater effect on the crystallite surfaces than on the grain boundary surfaces.

  9. Endoscopic Versus Open Cubital Tunnel Release

    Science.gov (United States)

    Aldekhayel, Salah; Govshievich, Alexander; Lee, James; Tahiri, Youssef; Luc, Mario

    2016-01-01

    Background: Several surgical techniques exist for treatment of cubital tunnel syndrome. Endoscopic cubital tunnel release (ECTuR) has been recently reported as a promising minimally invasive technique. This study aims to compare outcomes and complications of open cubital tunnel release (OCTuR) and ECTuR in the treatment of idiopathic cubital tunnel syndrome. Methods: A systematic review of the literature (1980-2014) identified 118 citations. Studies including adults with idiopathic cubital tunnel treated exclusively by ECTuR or OCTuR were included. Outcomes of interest were postoperative grading, complications, number of reoperations, and the need for intraoperative conversion to another technique. Postoperative outcomes were combined into a uniform scale with 4 categories: “excellent,” “good,” “fair,” and “poor.” Results: Twenty studies met the inclusion criteria (17 observational and 3 comparative), representing 425 open and 556 endoscopic decompressions. In the open group, 79.8% experienced “good” or “excellent” results with 12% complication rate and 2.8% reoperation rate. In the endoscopic group, 81.8% experienced “good” or “excellent” results with 9% complication rate and 1.6% reoperation rate. Meta-analysis of 3 comparative studies demonstrated a significantly lower overall complication rate with ECTuR. Subgroup analysis of complications revealed a significantly higher incidence of scar tenderness and elbow pain with OCTuR. Conclusions: The current study demonstrates similar effectiveness between the endoscopic (ECTuR) and open (OCTuR) techniques for treatment of idiopathic cubital tunnel syndrome with similar outcomes, complication profiles, and reoperation rates. PMID:27418887

  10. Acute cholecystitis

    OpenAIRE

    Fialkowski, Elizabeth; Halpin, Valerie; Whinney, Robb R

    2008-01-01

    Acute cholecystitis causes unremitting right upper quadrant pain, anorexia, nausea, vomiting, and fever, and if untreated can lead to perforations, abscess formation, or fistulae. About 95% of people with acute cholecystitis have gallstones.It is thought that blockage of the bile duct by a gallstone or local inflammation can lead to acute cholecystitis, but we don't know whether bacterial infection is also necessary.

  11. Acute cholecystitis

    OpenAIRE

    Halpin, Valerie

    2014-01-01

    Acute cholecystitis causes unremitting right upper quadrant pain, anorexia, nausea, vomiting, and fever, and if untreated can lead to perforations, abscess formation, or fistulae. About 95% of people with acute cholecystitis have gallstones.It is thought that blockage of the cystic duct by a gallstone or local inflammation can lead to acute cholecystitis, but we don't know whether bacterial infection is also necessary.

  12. Acute cholecystitis

    OpenAIRE

    Halpin, Valerie; Gupta, Aditya

    2011-01-01

    Acute cholecystitis causes unremitting right upper quadrant pain, anorexia, nausea, vomiting, and fever, and if untreated can lead to perforations, abscess formation, or fistulae. About 95% of people with acute cholecystitis have gallstones.It is thought that blockage of the bile duct by a gallstone or local inflammation can lead to acute cholecystitis, but we don't know whether bacterial infection is also necessary.

  13. Determination of vehicular pollution in the road tunnel of Vana ...

    African Journals Online (AJOL)

    Determination of vehicular pollution in the road tunnel of Vana (Haraz Road) in the ... source of pollution in a road tunnel, It has a harmful impact on Human health . ... undoubtedly one of the important sources of environmental and air pollution.

  14. High Performance Single Nanowire Tunnel Diodes

    DEFF Research Database (Denmark)

    Wallentin, Jesper; Persson, Johan Mikael; Wagner, Jakob Birkedal

    Semiconductor nanowires (NWs) have emerged as a promising technology for future electronic and optoelectronic devices. Epitaxial growth of III-V materials on Si substrates have been demonstrated, allowing for low-cost production. As the lattice matching requirements are much less strict than...... is the tunnel (Esaki) diode, which provides a low-resistance connection between junctions. We demonstrate an InP-GaAs NW axial heterostructure with tunnel diode behavior. InP and GaAs can be readily n- and p-doped, respectively, and the heterointerface is expected to have an advantageous type II band alignment...

  15. Treatment of repetitive use carpal tunnel syndrome

    Science.gov (United States)

    Smith, Chadwick F.; Vangsness, C. Thomas; Anderson, Thomas; Good, Wayne

    1995-05-01

    In 1990, a randomized, double-blind study was initiated to evaluate the use of an eight-point conservative treatment program in carpal tunnel syndrome. A total of 160 patients were delineated with symptoms of carpal tunnel syndrome. These patients were then divided into two groups. Both groups were subjected to an ergonomically correct eight-point work modification program. A counterfeit low level laser therapy unit was utilized in Group A, while an actual low level laser therapy unit was utilized in Group B. The difference between Groups A and B was statistically significant in terms of return to work, conduction study improvement, and certain range of motion and strength studies.

  16. Fire Resistant Panels for the Tunnel Linings

    Directory of Open Access Journals (Sweden)

    Gravit Marina

    2016-01-01

    Full Text Available Presents the results of studies of innovative materials in the field of experimental and theoretical research fire resistance fireproof panels Pyro-Safe Aestuver T. Owing to the assembly simplicity, materials cheapness, high ecological standard, recycling, reuse potential, are benefit. Research work is running to improve the knowledge about fireproof panels Pyro-Safe Aestuver T for tunnel lining, its basic performance, its long term behavior and in particular also its fire proof for example when used for the lining of road tunnels.

  17. Tunneling spectroscopy using a probe qubit

    Science.gov (United States)

    Berkley, A. J.; Przybysz, A. J.; Lanting, T.; Harris, R.; Dickson, N.; Altomare, F.; Amin, M. H.; Bunyk, P.; Enderud, C.; Hoskinson, E.; Johnson, M. W.; Ladizinsky, E.; Neufeld, R.; Rich, C.; Smirnov, A. Yu.; Tolkacheva, E.; Uchaikin, S.; Wilson, A. B.

    2013-01-01

    We describe a quantum tunneling spectroscopy technique that requires only low-bandwidth control. The method involves coupling a probe qubit to the system under study to create a localized probe state. The energy of the probe state is then scanned with respect to the unperturbed energy levels of the probed system. Incoherent tunneling transitions that flip the state of the probe qubit occur when the energy bias of the probe is close to an eigenenergy of the probed system. Monitoring these transitions allows the reconstruction of the probed system eigenspectrum. We demonstrate this method on an rf SQUID flux qubit.

  18. Prevalence of carpal tunnel syndrome in motorcyclists.

    Science.gov (United States)

    Manes, Harvey R

    2012-05-01

    Carpal tunnel syndrome is prevalent in patients who have a repetitive motion, vibration, or pressure exerted on the wrist joint for an extended period of time. The prevalence of this condition in the general population is approximately 5%. Motorcyclists subject themselves to high levels of vibration from the road and use their wrists to control the motorcycle's brakes, gas intake, and gears via the handlebars. Under these conditions, the author hypothesized that an increased prevalence of carpal tunnel syndrome would be observed in this population. Copyright 2012, SLACK Incorporated.

  19. Wind Tunnel Measurements at LM Wind Power

    DEFF Research Database (Denmark)

    Bertagnolio, Franck

    2012-01-01

    This section presents the results obtained during the experimental campaign that was conducted in the wind tunnel at LM Wind Power in Lunderskov from August 16th to 26th, 2010. The goal of this study is to validate the so-called TNO trailing edge noise model through measurements of the boundary...... layer turbulence characteristics and the far-field noise generated by the acoustic scattering of the turbulent boundary layer vorticies as they convect past the trailing edge. This campaign was conducted with a NACA0015 airfoil section that was placed in the wind tunnel section. It is equipped with high...

  20. Tunneling Transitions in de Sitter Spacetime

    Science.gov (United States)

    Lee, Bum-Hoon; Lee, Wonwoo

    We study tunneling transitions in de Sitter space. The self-gravitating scalar field with O(4) symmetry is taken into account. In this consideration the inherent property of Euclidean de Sitter geometry plays an important role in vacuum tunneling transitions. We extend Parke's results to other classes of true vacuum bubbles, false vacuum bubbles, and degenerate cases. We mention that the pair creation of black holes can be possible in the background of bubble solutions. This article is prepared for the proceedings of International Symposium on Cosmology and Particle Astrophysics(CosPA2008) in Korea, Oct 2008.

  1. Scanning tunneling spectroscopy of graphene on graphite.

    Science.gov (United States)

    Li, Guohong; Luican, Adina; Andrei, Eva Y

    2009-05-01

    We report low temperature high magnetic field scanning tunneling microscopy and spectroscopy of graphene flakes on graphite that exhibit the structural and electronic properties of graphene decoupled from the substrate. Pronounced peaks in the tunneling spectra develop with increasing field revealing a Landau level sequence that provides a direct way to identify graphene and to determine the degree of its coupling to the substrate. The Fermi velocity and quasiparticle lifetime, obtained from the positions and width of the peaks, provide access to the electron-phonon and electron-electron interactions.

  2. Tunnel magnetoresistance in ferromagnetic double-barrier planar junctions: coherent tunneling regime

    CERN Document Server

    Wilczynski, M

    2000-01-01

    Coherent tunneling in a double-barrier system consisting of two external ferromagnetic electrodes and a nonmagnetic central one is studied theoretically within the free-electron approximation. It is shown that the junction resistance depends on the relative orientation of magnetic moments of the ferromagnetic electrodes (so-called tunnel magnetoresistance). The magnetoresistance vs. thickness of the central electrode shows pronounced peaks related to the resonant tunneling through the whole system. Variation of the magnetoresistance with bias voltage is also studied. This variation is generally nonmonotonous.

  3. Automatic Attitude Setting of a Wind Tunnel Model in a Transonic Wind Tunnel

    OpenAIRE

    HAKII, Kiyoshi; KOIKE, Akira; 波木井, 潔; 小池, 陽

    1980-01-01

    A description of an improved automatic attitude setting system, of a wind tunnel model in a 2m×2m transonic wind tunnel is presented. The purpose of this improvement is to save on manpower, and shorten the access time for setting from one testing condition to another. An 8K words mini-computer is employed, to control the electirically powered mechanism of the model supporting system. The desired angle of attack and yaw of the wind tunnel model are obtained by the appropriate combination of th...

  4. Rehabilitation following carpal tunnel release.

    Science.gov (United States)

    Peters, Susan; Page, Matthew J; Coppieters, Michel W; Ross, Mark; Johnston, Venerina

    2016-02-17

    Various rehabilitation treatments may be offered following carpal tunnel syndrome (CTS) surgery. The effectiveness of these interventions remains unclear. This is the first update of a review first published in 2013. To review the effectiveness and safety of rehabilitation interventions following CTS surgery compared with no treatment, placebo, or another intervention. On 29 September 2015, we searched the Cochrane Neuromuscular Specialised Register, the Cochrane Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE, CINAHL Plus, AMED, LILACS, and PsycINFO. We also searched PEDro (3 December 2015) and clinical trials registers (3 December 2015). Randomised or quasi-randomised clinical trials that compared any postoperative rehabilitation intervention with either no intervention, placebo, or another postoperative rehabilitation intervention in individuals who had undergone CTS surgery. Two review authors independently selected trials for inclusion, extracted data, assessed risk of bias, and assessed the quality of the body of evidence for primary outcomes using the GRADE (Grades of Recommendation, Assessment, Development and Evaluation) approach according to standard Cochrane methodology. In this review we included 22 trials with a total of 1521 participants. Two of the trials were newly identified at this update. We studied different rehabilitation treatments including immobilisation using a wrist orthosis, dressings, exercise, controlled cold therapy, ice therapy, multi-modal hand rehabilitation, laser therapy, electrical modalities, scar desensitisation, and arnica. Three trials compared a rehabilitation treatment to a placebo, four compared rehabilitation to a no treatment control, three compared rehabilitation to standard care, and 15 compared various rehabilitation treatments to one another.Overall, the included studies were very low in quality. Thirteen trials explicitly reported random sequence generation; of these, five adequately concealed the

  5. Objectification of surgical treatment of carpal tunnel syndrome

    OpenAIRE

    Dvořáková, Marie

    2011-01-01

    Title: Objectification of surgical treatment of carpal tunnel syndrome Objectives: The main aim of this work is to evaluate the effectiveness of surgical treatment of carpal tunnel syndrome. Methods: In this work was used a two-point discrimination test, that evaluated tactile sensory of the hand with carpal tunnel syndrome. It evaluated the change of discriminatory sensation after surgical treatment of carpal tunnel syndrome. The results of testing were evaluated by using the SigmaPlot stati...

  6. Effects of femoral bone tunnel characteristics on graft-bending angle in double-bundle anterior cruciate ligament reconstruction: a comparison of the outside-in and transportal techniques.

    Science.gov (United States)

    Niki, Yasuo; Nagai, Katsuya; Harato, Kengo; Suda, Yasunori; Nakamura, Masaya; Matsumoto, Morio

    2017-04-01

    Bone tunnel creation techniques influence the 3-dimensional (3D) position of bone tunnels and graft-bending angle in anterior cruciate ligament (ACL) reconstruction. This study assessed graft-bending angle and 3D characteristics of femoral bone tunnels and compared them between outside-in (OI) and transportal (TP) techniques. Participants comprised 64 patients who underwent anatomic double-bundle ACL reconstruction, allocated to OI and TP groups (n = 32 each). The graft orientation plane exhibiting the largest graft-bending angle at the femoral tunnel aperture with the knee in extension was reconstructed from CT data using 3D imaging software. In this plane, graft-bending angle was compared between the OI and TP techniques. Although positionings of the intra-articular apertures of the femoral and tibial bone tunnels were similar, several spatial parameters of bone tunnels differed between techniques. Graft-bending angles of both anteromedial and posterolateral bundles were significantly more acute with the OI technique than with the TP technique. On coronal-plane CT, angle of the bone tunnel axis relative to the distal condylar axis correlated negatively with graft-bending angle, while in the axial plane, angle of the bone tunnel axis relative to the posterior condylar axis correlated positively with graft-bending angle. Lysholm score, pivot shift test, and anteroposterior laxity at >2.5-year follow-up demonstrated no significant differences between techniques. Different bone tunnel directions in OI and TP techniques substantially affected graft-bending angle , despite similar positionings of the intra-articular apertures. Graft-bending angle with the OI technique was acute, but risk of posterior blowout of the lateral femoral condyle was decreased. Surgeons should create the femoral tunnel while considering an obtuse graft-bending angle without increasing the risk of posterior blowout. III.

  7. Wind Tunnel Interference on Wings, Bodies and Airscrews

    Science.gov (United States)

    1933-09-13

    conveniently from those of 6, owing to the form of equation (9.08). bb, I , 6. J. The interference factor in each type of tunnel can be expressed formally by... metod of estimating the magnitude 7 ft. dosed tunnel agree very closely with tests made in a free jet. of the tunnel constraint. The theoretical formula

  8. Magnetic tunnel transistor with a silicon hot-electron emitter

    NARCIS (Netherlands)

    Le Minh, P.; Gökcan, H.; Lodder, J.C.; Jansen, R.

    2005-01-01

    We report on a modified magnetic tunnel transistor having a silicon tunnel emitter. The device has the structure Si/Al2O3 /base/Si with a spin-valve metal base, a Schottky barrier collector, but a silicon emitter separated from the base by a thin tunnel oxide. The energy of the hot electrons

  9. Tunnel operator training with a conversational agent-assistant

    NARCIS (Netherlands)

    Buiel, E.; Lubbers, J.; Doesburg, W. van; Muller, T.

    2009-01-01

    A tunnel operator monitors and regulates the flow of traffic inside a tunnel. Tunnel operators need to train in a simulator regularly in order to maintain proficiency in handling incident situations. During quiet working hours, the operator has enough time for training. But generally at that time no

  10. Tunneling time distribution by means of Nelson's quantum ...

    Indian Academy of Sciences (India)

    We construct a tunneling time distribution by means of Nelson's quantum mechanics and investigate statistical properties of the tunneling time distribution. As a result, we find that the relationship between the average and the variance of the tunneling time shows 'wave-particle duality'.

  11. Novel technique for passing tendon grafts through bone tunnels.

    Science.gov (United States)

    Levy, Jeffrey A; Farber, Gerald L; Taylor, Kenneth F

    2012-11-01

    Anatomic reconstruction in orthopedic surgery often requires the passage of soft tissue through bone tunnels. Difficulties may arise due to anatomic constraints surrounding the bone tunnels or the graft size. The authors present a novel technique for passing tendon grafts through bone tunnels that is simple, readily available, effective, and comparatively inexpensive. Copyright 2012, SLACK Incorporated.

  12. Cubital tunnel syndrome: A report of two cases | Suleman | SA ...

    African Journals Online (AJOL)

    Cubital tunnel syndrome is the second most common peripheral neuropathy of the upper limb. This is due to the anatomy of the tunnel, the physiological changes that the nerve undergoes during elbow flexion, as well as pathological conditions that occur within the tunnel. We present two cases of ulnar neuropathy occurring ...

  13. 46 CFR 171.100 - Shaft tunnels and stern tubes.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Shaft tunnels and stern tubes. 171.100 Section 171.100... PERTAINING TO VESSELS CARRYING PASSENGERS Additional Subdivision Requirements § 171.100 Shaft tunnels and... and the machinery space must be located in a watertight shaft tunnel. The vessel must be designed so...

  14. Structural Design of Linings for Bored Tunnels in Soft Ground

    NARCIS (Netherlands)

    Bakker, K.J.

    2003-01-01

    The increase of bored tunnels in the Netherlands has raised the question how to design the tunnel structure in an efficient way. As a large part of the cost of a bore tunnel is related to the cost of the lining, it is important to design the lining in a cost-effective way. In the Netherlands it is

  15. Numerical analysis of surface subsidence in asymmetric parallel highway tunnels

    Directory of Open Access Journals (Sweden)

    Ratan Das

    2017-02-01

    Full Text Available Tunnelling related hazards are very common in the Himalayan terrain and a number of such instances have been reported. Several twin tunnels are being planned for transportation purposes which will require good understanding for prediction of tunnel deformation and surface settlement during the engineering life of the structure. The deformational behaviour, design of sequential excavation and support of any jointed rock mass are challenging during underground construction. We have raised several commonly assumed issues while performing stability analysis of underground opening at shallow depth. For this purpose, Kainchi-mod Nerchowck twin tunnels (Himachal Pradesh, India are taken for in-depth analysis of the stability of two asymmetric tunnels to address the influence of topography, twin tunnel dimension and geometry. The host rock encountered during excavation is composed mainly of moderately to highly jointed grey sandstone, maroon sandstone and siltstones. In contrast to equidimensional tunnels where the maximum subsidence is observed vertically above the centreline of the tunnel, the result from the present study shows shifting of the maximum subsidence away from the tunnel centreline. The maximum subsidence of 0.99 mm is observed at 4.54 m left to the escape tunnel centreline whereas the maximum subsidence of 3.14 mm is observed at 8.89 m right to the main tunnel centreline. This shifting clearly indicates the influence of undulating topography and in-equidimensional noncircular tunnel.

  16. Graft Bending Angle at the Intra-articular Femoral Tunnel Aperture After Single-Bundle Posterior Cruciate Ligament Reconstruction: Inside-Out Versus Outside-In Techniques.

    Science.gov (United States)

    Jang, Ki-Mo; Park, Sung-Chul; Lee, Dae-Hee

    2016-05-01

    To date, no in vivo 3-dimensional computed tomography (3D-CT) studies have compared graft bending angles at the femoral tunnel aperture and femoral tunnel length in patients who underwent posterior cruciate ligament (PCL) reconstruction with outside-in (OI) and inside-out (IO) techniques. This study used in vivo 3D-CT analysis to compare graft bending angles at the femoral tunnel aperture and femoral tunnel lengths after OI and IO femoral drilling techniques in single-bundle PCL reconstruction. It was hypothesized that the graft bending angle at the femoral tunnel aperture would be less acute with the OI compared with the IO technique, with no difference in femoral tunnel lengths. Cross-sectional study; Level of evidence, 3. Immediate postoperative in vivo 3D-CT and curved planar reformation were used to assess the graft bending angles and femoral tunnel lengths in the sagittal, axial, and coronal planes in 67 patients who underwent single-bundle PCL reconstruction with the OI (n = 37) and IO (n = 30) techniques. The mean graft bending angles on the sagittal and axial planes were 8.2° more acute (23.5° vs 15.3°, P = .011) and 5.3° more acute (49.0° vs 43.7°, P = .013), respectively, with the IO compared with the OI technique, but the difference in the coronal plane was not statistically significant (25.3° vs 24.8°, P = .623). Femoral tunnel length was similar in the 2 groups. The graft bending angles in single-bundle PCL reconstruction were more acute in the sagittal and axial planes with the IO compared with the OI technique, but there was no difference in the coronal plane. In addition, femoral tunnel lengths did not differ significantly in patients who underwent OI and IO single-bundle PCL reconstructions. Although further biomechanical studies are needed to evaluate the effect on graft failure of a <10° difference in graft bending angle, the small magnitude of this difference would likely have little adverse effect on graft survival. © 2016 The Author(s).

  17. High non-anatomic tunnel position rates in ACL reconstruction failure using both transtibial and anteromedial tunnel drilling techniques.

    Science.gov (United States)

    Jaecker, Vera; Zapf, Tabea; Naendrup, Jan-Hendrik; Pfeiffer, Thomas; Kanakamedala, Ajay C; Wafaisade, Arasch; Shafizadeh, Sven

    2017-09-01

    Although it is well known from cadaveric and biomechanical studies that transtibial femoral tunnel (TT) positioning techniques are associated with non-anatomic tunnel positions, controversial data exist as so far no clinical differences could have been found, comparing transtibial with anteromedial techniques (AM). The purpose of the study was to analyze if graft failure following TT ACL reconstruction was more commonly associated with non-anatomic tunnel position in comparison with the AM technique. We hypothesized that, compared to AM techniques, non-anatomic tunnel positions correlate with TT tunnel positioning techniques. A total of 147 cases of ACL revision surgery were analyzed retrospectively. Primary ACL reconstructions were analyzed regarding the femoral tunnel drilling technique. Femoral and tibial tunnel positions were determined on CT scans using validated radiographic measurement methods. Correlation analysis was performed to determine differences between TT and AM techniques. A total of 101 cases were included, of whom 64 (63.4%) underwent the TT technique and 37 (36.6%) the AM technique for primary ACL reconstruction. Non-anatomic femoral tunnel positions were found in 77.2% and non-anatomical tibial tunnel positions in 40.1%. No correlations were found comparing tunnel positions in TT and AM techniques, revealing non-anatomic femoral tunnel positions in 79.7 and 73% and non-anatomic tibial tunnel positions in 43.7 and 35.1%, respectively (p > 0.05). Considerable rates of non-anatomic femoral and tibial tunnel positions were found in ACL revisions with both transtibial and anteromedial femoral drilling techniques. Despite the potential of placing tunnels more anatomically using an additional AM portal, this technique does not ensure anatomic tunnel positioning. Consequently, the data highlight the importance of anatomic tunnel positioning in primary ACL reconstruction, regardless of the applied drilling technique.

  18. Bronchitis (acute)

    OpenAIRE

    Wark, Peter

    2015-01-01

    Acute bronchitis affects more than 40 in 1000 adults per year in the UK. The causes are usually considered to be infective, but only around half of people have identifiable pathogens.The role of smoking or environmental tobacco smoke inhalation in predisposing to acute bronchitis is unclear.One third of people may have longer-term symptoms or recurrence.

  19. Acute nierschade

    NARCIS (Netherlands)

    Hageman, D.; Kooman, J.P.; Lance, M.D.; van Heurn, L.W.E.; Snoeijs, M.G.

    2012-01-01

    - 'Acute kidney injury' is modern terminology for a sudden decline in kidney function, and is defined by the RIFLE classification (RIFLE is an acronym for Risk, Injury, Failure, Loss and End-stage kidney disease).- Acute kidney injury occurs as a result of the combination of reduced perfusion in the

  20. Silicon-germanium nanowire tunnel-FETs with homo- and heterostructure tunnel junctions

    Science.gov (United States)

    Richter, S.; Blaeser, S.; Knoll, L.; Trellenkamp, S.; Fox, A.; Schäfer, A.; Hartmann, J. M.; Zhao, Q. T.; Mantl, S.

    2014-08-01

    Experimental results on tunneling field-effect transistors (TFETs) based on strained SiGe on SOI nanowire arrays are presented. A heterostructure SiGe/Si TFET with a vertical tunnel junction consisting of an in situ doped SiGe source and a Si channel with a minimum inverse subthreshold slope of 90 mV/dec is demonstrated. An increase in tunneling area results in higher on-current. The in situ doped heterojunction TFET shows great improvement compared to a homojunction SiGe on SOI nanowire design with implanted junctions. Temperature dependent measurements and device simulations are performed in order to analyze the tunnel transport mechanism in the devices.

  1. Asymmetric voltage behavior of the tunnel magnetoresistance in double barrier magnetic tunnel junctions

    KAUST Repository

    Useinov, Arthur

    2012-06-01

    In this paper, we study the value of the tunnel magnetoresistance (TMR) as a function of the applied voltage in double barrier magnetic tunnel junctions (DMTJs) with the left and right ferromagnetic (FM) layers being pinned and numerically estimate the possible difference of the TMR curves for negative and positive voltages in the homojunctions (equal barriers and electrodes). DMTJs are modeled as two single barrier junctions connected in series with consecutive tunneling (CST). We investigated the asymmetric voltage behavior of the TMR for the CST in the range of a general theoretical model. Significant asymmetries of the experimental curves, which arise due to different annealing regimes, are mostly explained by different heights of the tunnel barriers and asymmetries of spin polarizations in magnetic layers. © (2012) Trans Tech Publications.

  2. Resonant tunnel magnetoresistance in double-barrier planar magnetic tunnel junctions

    KAUST Repository

    Useinov, A. N.

    2011-08-24

    We present a theoretical approach to calculate the spin-dependent current and tunnel magnetoresistance (TMR) in a double-barrier magnetic tunnel junction (DMTJ), in which the magnetization of the middle ferromagnetic metal layer can be aligned parallel or antiparallel in relation to the fixed magnetizations of the left and right ferromagnetic electrodes. The electron transport through the DMTJ is considered as a three-dimensional problem, taking into account all transmitting electron trajectories as well as the spin-dependent momentum conservation law. The dependence of the transmission coefficient and spin-polarized currents on the applied voltage is derived as an exact solution to the quantum-mechanical problem for the spin-polarized transport. In the range of the developed physical model, the resonant tunneling, nonresonant tunneling, and enhanced spin filtering can be explained; the simulation results are in good agreement with experimental data.

  3. Tunneling methods used at the railway tunnels construction in Slovak republic

    Directory of Open Access Journals (Sweden)

    Jozef Čížik

    2007-10-01

    Full Text Available Rail transport is an energy-efficient and capital-intensive means of mechanized land transport. Methods of tunneling vary with the nature of the material to be cut through. When soft earth is encountered, the excavation is timbered for support as the work advances; the timbers are sometimes left as a permanent lining for the tunnel. Another method is to cut two parallel excavations in which the side walls are constructed first. Arches connecting them are then built as the material between them is extracted. Portions of the unexcavated center, left temporarily for support, may be removed later. A tunnel cut through rock frequently requires no lining. Often, to speed construction, work is started at both ends. This poses no problem with the cut-and-cover method, but when the tunnel is bored from within, it must be assured that the tubes will actually meet in the center. Modern methods accomplish this with high precision.

  4. 40 CFR Table F-2 to Subpart F of... - Particle Sizes and Wind Speeds for Full Wind Tunnel Test, Wind Tunnel Inlet Aspiration Test, and...

    Science.gov (United States)

    2010-07-01

    ... Wind Tunnel Test, Wind Tunnel Inlet Aspiration Test, and Static Chamber Test F Table F-2 to Subpart F... Part 53—Particle Sizes and Wind Speeds for Full Wind Tunnel Test, Wind Tunnel Inlet Aspiration Test, and Static Chamber Test Primary Partical Mean Size a (µm) Full Wind Tunnel Test 2 km/hr 24 km/hr Inlet...

  5. High-Performance Single Nanowire Tunnel Diodes

    DEFF Research Database (Denmark)

    Wallentin, Jesper; Persson, Johan Mikael; Wagner, Jakob Birkedal

    2010-01-01

    We demonstrate single nanowire tunnel diodes with room temperature peak current densities of up to 329 A/cm(2). Despite the large surface to volume ratio of the type-II InP-GaAs axial heterostructure nanowires, we measure peak to valley current ratios (PVCR) of up to 8.2 at room temperature and 27...

  6. B-Target Room Tunnel Redesigned

    Energy Technology Data Exchange (ETDEWEB)

    Esfandiari, Reza; /San Jose State U. /SLAC

    2010-08-25

    Several groups at SLAC National Accelerator Laboratory are currently working on a RF Modulator prototype for a future linear collider known as the International Linear Collider (ILC). The ILC runs using about a 1000 Klystrons which create high power carrier waves for the particle acceleration. Klystrons receive their electrical input power from modulators. In order to move beyond the prototype phase, the laboratory might expand its ground base further down a tunnel located at the End Station B (ESB) in order to house four new Klystron Modulator Test Stations. This area is known as the B-Target Room Tunnel, and the task was to redesign the tunnel layout for the upcoming changes. The project first began by collecting substantial amount of information about the prototyped project, the tunnel and the researchers feedback of what they would like to see in the upcoming design. Subsequent to numerous planning and presentations, one particular design was. Calculations for this design were then performed for the most complex aspects of the project. Based on the results of the calculations, specific sample beams, welds, bolts and materials were chosen for the possible future construction.

  7. delta-biased Josephson tunnel junctions

    DEFF Research Database (Denmark)

    Monaco, R.; Mygind, Jesper; Koshelet, V.

    2010-01-01

    Abstract: The behavior of a long Josephson tunnel junction drastically depends on the distribution of the dc bias current. We investigate the case in which the bias current is fed in the central point of a one-dimensional junction. Such junction configuration has been recently used to detect...

  8. The overshoot problem in inflation after tunneling

    Energy Technology Data Exchange (ETDEWEB)

    Dutta, Koushik; Vaudrevange, Pascal M.; Westphal, Alexander

    2011-09-15

    We show the absence of the usual parametrically large overshoot problem of small-field inflation if initiated by a Coleman-De Luccia (CDL) tunneling transition from an earlier vacuum in the limit of small inflationary scale compared to the tunneling scale. For low-power monomial exit potentials V({phi}){proportional_to} {phi}{sup n}; n<4, we derive an expression for the amount of overshoot. This is bounded from above by the width of the steep barrier traversed after emerging from tunneling and before reaching a slow-roll region of the potential. For n{>=}4 we show that overshooting is entirely absent. We extend this result through binomials to a general potential written as a series expansion, and to the case of arbitrary finite initial speed of the inflaton. This places the phase space of initial conditions for small-field and large-field inflation on the same footing in a landscape of string theory vacua populated via CDL tunneling. (orig.)

  9. A Student-Built Scanning Tunneling Microscope

    Science.gov (United States)

    Ekkens, Tom

    2015-01-01

    Many introductory and nanotechnology textbooks discuss the operation of various microscopes including atomic force (AFM), scanning tunneling (STM), and scanning electron microscopes (SEM). In a nanotechnology laboratory class, students frequently utilize microscopes to obtain data without a thought about the detailed operation of the tool itself.…

  10. Tunneling of trapped-atom Bose condensates

    Indian Academy of Sciences (India)

    The dynamical equations are of the canonical form for the two conjugate variables, and the Hamiltonian corresponds to that of a momentum-shortened pendulum, supporting a richer set of tunneling oscillation modes than for a superconductor Josephson junction, that has a fixed-length pendulum as a mechanical model.

  11. Outcome analysis of cubital tunnel decompression.

    Science.gov (United States)

    Jariwala, A; Bansal, N; Nicol, G M; Shelton, J; Wigderowitz, C A

    2015-08-01

    Cubital tunnel decompression is a commonly undertaken upper limb procedure. Most studies compare the different techniques of decompression; however, only a few have specifically investigated the outcome of ulnar nerve decompression. The aim of this study was to investigate the outcome of ulnar nerve decompression following cubital tunnel syndrome. A total of 174 ulnar nerve decompression cases were identified from the upper limb surgery database with complete data available for 136 cases. Simple decompression was performed in 110 (80.88%) cases, and in 26 (19.12%), anterior subcutaneous transposition was also supplemented. These operations were performed at three different hospitals by surgeons of different levels of experience. The most common cause of cubital tunnel syndrome was idiopathic. The outcome was satisfactory in 86% of cases. No obvious association was demonstrated between the outcome of surgery and duration of symptoms, presence of co-morbidities or the type of surgery performed. This is the largest outcome analysis of the results of ulnar nerve decompression at the elbow. Good results following nerve decompression were attained in 86% of cases without any significant effect of duration of symptoms or co-morbidities on the outcome of surgery. It is hoped that the findings of the current study will help general practitioners, junior doctors and surgeons in their management and pre-operative consultation with patients having cubital tunnel syndrome. © The Author(s) 2015.

  12. Tunneling times and the Hartman effect revisited

    Energy Technology Data Exchange (ETDEWEB)

    Olkhovsky, Vladislav S. [Ukrainian Academy of Sciences, Kiev (Ukraine). Inst. for Nuclear Research]|[Istituto Nazionale di Fisica Nucleare, Catania (Italy); Recami, Erasmo [Universidade Estadual de Campinas, SP (Brazil). Dept. de Matematica Aplicada]|[Istituto Nazionale di Fisica Nucleare, Milano (Italy); Raciti, Fabio [Catania Univ. (Italy). Dipt. di Fisica; Zaichenko, Aleksandr K. [Ukrainian Academy of Sciences, Kiev (Ukraine)

    1995-05-01

    In a recent review paper we proposed, within conventional quantum mechanics, new definitions for the sub-barrier tunnelling and reflection times. Aims of the present paper are: presenting and analysing the results of various numerical calculations (based on our equations) on the penetration and return times < {tau}Pen >, <{tau}Ret >, during tunneling inside a rectangular potential barrier, for various penetration depths x{sub f}; putting forth and discussing suitable definitions, besides of the mean values, also of the variances (or dispersions) D {sup {tau}}T D {sup {tau}}R for the time durations of transmission and reflection process; mentioning that our definition < {sup {tau}}T > for the average transmission time results to constitute an improvement of the ordinary dwell-time {tau}{sup Dw} formula; commenting upon some recent criticism by C.R. Leavens, on the basis of our new numerical results. We stress that our numerical evaluations confirm that our approach implied and implies, the existence of the Hartman effect: an effect that in these days (due to the theoretical connections between tunneling and evanescent wave propagation) is receiving - at Cologne, Berkeley, Florence and Vienna- indirect, but quite interesting, experimental verifications. At last, we briefly analyze some other definitions of tunnelling times. (author). 24 refs., 5 figs.

  13. Integrated tunneling sensor for nanoelectromechanical systems

    DEFF Research Database (Denmark)

    Sadewasser, S.; Abadal, G.; Barniol, N.

    2006-01-01

    distances, attractive van der Waals and capillary forces become sizable, possibly resulting in snap-in of the electrodes. The authors present a comprehensive analysis and evaluation of the interplay between the involved forces and identify requirements for the design of tunneling sensors. Based...

  14. Resonant tunneling in a pulsed phonon field

    DEFF Research Database (Denmark)

    Kral, P.; Jauho, Antti-Pekka

    1999-01-01

    , The nonequilibrium spectral function for the resonance displays the formation and decay of the phonon sidebands on ultrashort time scales. The time-dependent tunneling current through the individual phonon satellites reflects this quasiparticle formation by oscillations, whose time scale is set by the frequency...

  15. PRACTICAL DETERMINATION OF TUNNEL ENTRANCE LIGHTING NEEDS

    NARCIS (Netherlands)

    SCHREUDER, DA

    1991-01-01

    The determination of the field factor that relates the visibility conditions in the laboratory to the visibility conditions for a car driver approaching the entrance of a long tunnel is discussed. Experimental results are given from research in the netherlands. Suggestions are given for

  16. Enhanced Tunnelling Models for Child Universe Formation

    CERN Document Server

    Ansoldi, S; Shilon, I

    2015-01-01

    Starting from a recently proposed model that allows for an enhanced rate of child universe production under generic conditions, we elaborate on refinements that may allow for non-singular initial configurations. A possibility to treat both, the initial state and the tunnelling beyond the semiclassical level will also be introduced.

  17. Tunneling of electrons through semiconductor superlattices

    Indian Academy of Sciences (India)

    Unknown

    The SSL we have considered is Ga0⋅7Al0⋅3As–GaAs which has been drawing considerable attention during the recent past on account of some typical features of its band structure. We have indicated how our results would help fabrication of ultra high speed devices. Keywords. Semiconductor superlattices; tunneling. 1.

  18. Towards high-speed scanning tunneling microscopy

    NARCIS (Netherlands)

    Tabak, Femke Chantal

    2013-01-01

    In this thesis, two routes towards high-speed scanning tunneling microscopy (STM) are described. The first possibility for high-speed scanning that is discussed is the use of MEMS (Micro-Electro Mechanical Systems) devices as high-speed add-ons in STM microscopes. The functionality of these devices

  19. Employees' Knowledge of Carpal Tunnel Syndrome.

    Science.gov (United States)

    Gandy-Goldston, Terrie M.

    A study examined employees' knowledge of the causes of carpal tunnel syndrome (CTS), its prevention, and their legal rights after being diagnosed with CTS. A 24-item questionnaire was administered to a random sample of 30 Chicago-area employees who had been afflicted with CTS. Of those surveyed, 99% considered their CTS injury related to their…

  20. Carpal Tunnel Syndrome in ARL Libraries.

    Science.gov (United States)

    Thornton, Joyce K.

    1997-01-01

    A survey of 72 member libraries in the Association of Research Libraries revealed the incidence of carpal tunnel syndrome (CTS) and the measures taken to cope with it. Recommends implementing proactive ergonomics programs; soliciting staff input for solutions; providing report guidelines; using external help; stressing preventive measures and…

  1. Microscopic tunneling theory of long Josephson junctions

    DEFF Research Database (Denmark)

    Grønbech-Jensen, N.; Hattel, Søren A.; Samuelsen, Mogens Rugholm

    1992-01-01

    We present a numerical scheme for solving a nonlinear partial integro-differential equation with nonlocal time dependence. The equation describes the dynamics in a long Josephson junction modeled by use of the microscopic theory for tunneling between superconductors. We demonstrate...

  2. Chaperone binding at the ribosomal exit tunnel

    DEFF Research Database (Denmark)

    Kristensen, Ole; Gajhede, Michael

    2003-01-01

    The exit tunnel region of the ribosome is well established as a focal point for interaction between the components that guide the fate of nascent polypeptides. One of these, the chaperone trigger factor (TF), associates with the 50S ribosomal subunit through its N-terminal domain. Targeting of TF...

  3. Wind Tunnel Measurements at Virginia Tech

    DEFF Research Database (Denmark)

    Fischer, Andreas; Bertagnolio, Franck

    2012-01-01

    In this section, the wind tunnel configuration used for aerodynamic and aeroacoustic measurement is described. Then, the validation of the method for evaluating far-field noise from surface microphones as described in Section 5 is presented. Finally, the design concept proposed in Section 6...

  4. Analysis of Mexico wind tunnel measurements

    DEFF Research Database (Denmark)

    Schepers, J.G.; Boorsma, K.; Cho, T.

    institutes carried out a wind tunnel experiment in the Large Low Speed Facility (LLF) of the German DutchWind Facilities DNW on a rotor with a diameter of 4.5 m. Pressure distributions were measured at five location along the blade along with detailed flow field measurements around the rotor plane using...

  5. Role of Wind Tunnels in Aircraft Design

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 8; Issue 1. Role of Wind Tunnels in Aircraft Design. S P Govinda Raju. General Article Volume 8 Issue 1 January 2003 pp 72-76. Fulltext. Click here to view fulltext PDF. Permanent link: http://www.ias.ac.in/article/fulltext/reso/008/01/0072-0076. Keywords.

  6. Tunnel Diode Discriminator with Fixed Dead Time

    DEFF Research Database (Denmark)

    Diamond, J. M.

    1965-01-01

    A solid state discriminator for the range 0.4 to 10 V is described. Tunnel diodes are used for the discriminator element and in a special fixed dead time circuit. An analysis of temperature stability is presented. The regulated power supplies are described, including a special negative resistance...

  7. Explosion risks and consequences for tunnels

    NARCIS (Netherlands)

    Weerheijm, J.; Berg, A.C. van den

    2014-01-01

    Tunnel accidents with transports of dangerous goods may lead to explosions. Risk assessment for these accidents is complicated because of the low probability and the unknown, but disastrous effects expected. Especially the lack of knowledge on the strength of the explosion and the consequences for

  8. Single electron tunneling based arithmetic computation

    NARCIS (Netherlands)

    Lageweg, C.R.

    2004-01-01

    In this dissertation we investigate the implementation of computer arithmetic operations with Single Electron Tunneling (SET) technology based circuits. In our research we focus on the effective utilization of the SET technologys specific characteristic, i.e., the ability to control the transport of

  9. Giant Tunneling Magnetoresistance (TMR) in Graphene Patches

    Science.gov (United States)

    Agapito, Luis; Kioussis, Nicholas

    2010-03-01

    Graphene-based field effect devices based on graphene flakes and nanoislands have attracted a great deal of attention due to their unique physical properties and potential for nanoelectronic applications. The emergence of magnetism[1,2] in nanometer graphene patches terminated by zigzag edges along with the low intrinsic spin-orbit interaction opens a new research venue for spintronics, such as tunneling magnetoresistance, spin filter, and quantum computing. We have employed density functional theory and the nonequilibrium Green's functions approach to study the charge and spin transport in tunnel junctions comprising of one and two zigzag-terminated graphene triangular flakes connected to reconstructed zigzag-terminated graphene ribbons. We will present results of (1) the interplay between gate voltage and its incidence on the selection of the filtered spin channel and (2) the effect of the relative orientation of the magnetizations of the two graphene nanoflakes on the transport of the tunnel junctions. The calculations demonstrate the possibility of engineering such graphene patches as magnetic tunneling junctions that exhibit giant TMR. [1] J. Fernandez-Rossier et al., Physical Review Letters 99 (2007). [2] W. L. Wang et al., Nano Letters 8, 241 (2008).

  10. Tsu-Esaki modeling of tunneling currents in ferroelectric tunnel junctions

    Science.gov (United States)

    Tuomisto, Noora; van Dijken, Sebastiaan; Puska, Martti

    2017-12-01

    We model tunneling currents through step barrier structures representative of ferroelectric tunnel junctions wherein one of the electrodes contributes to the barrier potential profile or an extra layer is grown between the ferroelectric barrier and one of the electrodes. We study current density-voltage (J-V) and tunneling electroresistance (TER) curves using the Tsu-Esaki formula with numerically calculated transmission. This method is computationally robust, and the same results cannot be obtained with the standard methods usually applied for interpreting experimental I-V curves. Our results predict that the effect of resonant tunneling produces asymmetry in the J-V curves and negative differential resistance characteristics. We show that the asymmetry of the J-V curves can be tuned by adjusting the barrier heights and widths and that changing the extra barrier width affects the asymmetry the most. The barrier widths and the main barrier height affect the magnitude of the tunneling current the most. The change in the tilt of the main barrier is suggested to produce a significant TER of the order of 102. Our numerical method provides a systematic way to study trends in tunneling currents through step barrier structures across a wide range of barrier parameters and bias voltages, in contrast to the necessity of employing several different approximations when using analytical formulae. Therefore, our method provides the means for interpreting existing and future experiments and can be used as a tool for designing new devices with desired functionalities.

  11. Outcome of radiologically placed tunneled haemodialysis catheters.

    Science.gov (United States)

    Sayani, Raza; Anwar, Muhammad; Tanveer-ul-Haq; Al-Qamari, Nauman; Bilal, Muhammad Asif

    2013-12-01

    To study the outcome of radiologically placed double lumen tunneled haemodialysis catheters for the management of renal failure. Case series. Interventional Suite of Radiology Department at the Aga Khan University Hospital, Karachi, from April 2010 to June 2011. All consecutive patients who were referred to the department of radiology by the nephrologists for double lumen tunneled haemodialysis catheter (Permacath) placement during the study period were included. Patients with septicemia, those for whom follow-up was not available, those coming for catheter exchange or who died due to a noncatheter related condition were excluded. A radio-opaque, soft silicone double lumen catheter was inserted through a subcutaneous tunnel created over the anterior chest wall. The catheter tip was placed in the right atrium via the internal jugular vein. Ultrasound guidance was used for initial venous puncture. The rest of the procedure was carried out under fluoroscopic guidance. Technical success, catheter related bacteremia rates, adequacy of dialysis, patency, and adverse events were analyzed. Overall 88 tunneled haemodialysis catheters were placed in 87 patients. Patients were followed-up for duration of 1 - 307 days with mean follow-up period of 4 months. Immediate technical success was 100%. The procedural complication rate was 5.6% (5 catheters). Eight patients died during the study period, seven from causes unrelated to the procedure. One patient died due to septicemia secondary to catheter related infection. Of the remaining 69 patients, 50 (72.4%) predominantly had uneventful course during the study period. Twelve patients developed infection (17.3%); two were successfully treated conservatively while in 10 patients catheter had to be removed. Seven catheters (10.1%) failed due to mechanical problems. In 3 patients the internal jugular veins got partially thrombosed. One catheter was accidentally damaged in the ward and had to be removed. Radiological guided tunneled

  12. Low-temperature scanning tunneling spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Kirk, M.D.

    1989-01-01

    A scanning tunneling microscope (STM) was designed and built to operate at liquid helium temperature and was used to measure highly localized electron tunneling spectroscopy. Several instruments were built, all capable of operating in many different environments: air, vacuum, liquid helium and in a transfer gas. An adaptation of one particular design was made into an atomic force microscope capable of operating at low temperatures. Using a low temperature STM, three adsorbed molecular species (liquid crystals, sorbic acid, and carbon monoxide), deposited on a graphite substrate, have been imaged at 4.2K. The inelastic tunneling spectra of these adsorbates show strong peaks in dI/dV vs V curves at energies that correspond to known vibrational modes. The increase in conductance at the onset of inelastic tunneling was measured to be as high as 100 times. The spatial variation of the spectra was measured and was seen to change dramatically on the scale of angstroms, suggesting that individual molecular bonds could be measured. A theoretical model is presented to explain the contrast seen in the STM images of adsorbed molecules, thereby explaining why adsorbed molecules appear to be more conductive than the background. The microscope proved very useful for measuring the energy gap of high temperature superconductors. These materials often have submicron grain sizes. For LaSrCuO, YBaCuO, and BiCaSrCuO, the conductance curves showed a large energy gap suggesting a strongly coupled superconductor. The conductance curves also indicated that intergrain tunneling may occur and that the background conductance varied linearly with the applied voltage. The crystalline structure of Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub 8+{delta}} was imaged by an STM operating in air and in ultra-high vacuum.

  13. Highly doped layer for tunnel junctions in solar cells

    Science.gov (United States)

    Fetzer, Christopher M.

    2017-08-01

    A highly doped layer for interconnecting tunnel junctions in multijunction solar cells is presented. The highly doped layer is a delta doped layer in one or both layers of a tunnel diode junction used to connect two or more p-on-n or n-on-p solar cells in a multijunction solar cell. A delta doped layer is made by interrupting the epitaxial growth of one of the layers of the tunnel diode, depositing a delta dopant at a concentration substantially greater than the concentration used in growing the layer of the tunnel diode, and then continuing to epitaxially grow the remaining tunnel diode.

  14. Mutual seismic interaction between tunnels and the surrounding granular soil

    Directory of Open Access Journals (Sweden)

    Mohamed Ahmed Abdel-Motaal

    2014-12-01

    Study results show that the maximum exerted straining actions in tunnel lining are directly proportional to the relative stiffness between tunnel and surrounding soil (lining thickness and soil shear modulus. Moreover, it is highly affected by the peak ground acceleration and the tunnel location (embedment depth. A comprehensive study is performed to show the effect of tunnel thickness and tunnel diameter on both the induced bending moment and lining deformation. In general, it is concluded that seismic analysis should be considered in regions subjected to peak ground acceleration greater than 0.15g.

  15. Use of 3D Printing for Custom Wind Tunnel Fabrication

    Science.gov (United States)

    Gagorik, Paul; Bates, Zachary; Issakhanian, Emin

    2016-11-01

    Small-scale wind tunnels for the most part are fairly simple to produce with standard building equipment. However, the intricate bell housing and inlet shape of an Eiffel type wind tunnel, as well as the transition from diffuser to fan in a rectangular tunnel can present design and construction obstacles. With the help of 3D printing, these shapes can be custom designed in CAD models and printed in the lab at very low cost. The undergraduate team at Loyola Marymount University has built a custom benchtop tunnel for gas turbine film cooling experiments. 3D printing is combined with conventional construction methods to build the tunnel. 3D printing is also used to build the custom tunnel floor and interchangeable experimental pieces for various experimental shapes. This simple and low-cost tunnel is a custom solution for specific engineering experiments for gas turbine technology research.

  16. Macroscopic Quantum Self-Trapping in Dynamical Tunneling

    Science.gov (United States)

    Wüster, Sebastian; Dabrowska, Beata J.; Davis, Matthew J.

    2012-08-01

    It is well known that increasing the nonlinearity due to repulsive atomic interactions in a double-well Bose-Einstein condensate suppresses quantum tunneling between the two sites. Here we find analogous behavior in the dynamical tunneling of a Bose-Einstein condensate between period-one resonances in a single driven potential well. For small nonlinearities we find unhindered tunneling between the resonances, but with an increasing period as compared to the noninteracting system. For nonlinearities above a critical value we generally observe that the tunneling shuts down. However, for certain regimes of modulation parameters we find that dynamical tunneling reemerges for large enough nonlinearities, an effect not present in spatial double-well tunneling. We develop a two-mode model in good agreement with full numerical simulations over a wide range of parameters, which allows the suppression of tunneling to be attributed to macroscopic quantum self-trapping.

  17. Acute Pancreatitis and Pregnancy

    Science.gov (United States)

    ... Pancreatitis Acute Pancreatitis and Pregnancy Acute Pancreatitis and Pregnancy Timothy Gardner, MD Acute pancreatitis is defined as ... pancreatitis in pregnancy. Reasons for Acute Pancreatitis and Pregnancy While acute pancreatitis is responsible for almost 1 ...

  18. Moisture Transport Through Sprayed Concrete Tunnel Linings

    Science.gov (United States)

    Holter, Karl Gunnar; Geving, Stig

    2016-01-01

    Waterproofing of permanent sprayed concrete tunnel linings with sprayed membranes in a continuous sandwich structure has been attempted since 2000 and has seen increased use in some countries. The main function of a sprayed membrane from a waterproofing perspective is to provide crack bridging and hence prevent flow of liquid water into the tunnel through cracks and imperfections in the concrete material. However, moisture can migrate through the concrete and EVA-based membrane materials by capillary and vapor diffusion mechanisms. These moisture transport mechanisms can have an influence on the degree of saturation, and may influence the pore pressures in the concrete material as well as risk of freeze-thaw damage of the concrete and membrane. The paper describes a detailed study of moisture transport material parameters, moisture condition in tunnel linings and climatic conditions tunnels in hard rock in Norway. These data have been included in a hygrothermal simulation model in the software WUFI for moisture transport to substantiate moisture transport and long-term effects on saturation of the concrete and membrane material. The findings suggest that EVA-based membranes exhibit significant water absorption and vapor transport properties although they are impermeable to liquid water flow. State-of-the-art sprayed concrete material applied with the wet mix method exhibits very low hydraulic conductivities, lower than 10-14 m/s, thus saturated conductive water flow is a very unlikely dominant transport mechanism. Moisture transport through the lining structure by capillary flow and vapor diffusion are calculated to approximately 3 cm3/m2 per day for lining thicknesses in the range of 25-35 cm and seasonal Nordic climate variations. The calculated moisture contents in the tunnel linings from the hygrothermal simulations are largely in agreement with the measured moisture contents in the tunnel linings. The findings also indicate that the concrete material exhibits

  19. Tunnel magnetoresistance in epitaxially grown magnetic tunnel junctions using Heusler alloy electrode and MgO barrier

    Energy Technology Data Exchange (ETDEWEB)

    Tsunegi, S.; Sakuraba, Y.; Oogane, M.; Telling, N. D.; Shelford, L. R.; Arenholz, E.; van der Laan, G.; Hicken, R. J.; Takanashi, K.; Ando, Y.

    2009-07-01

    Epitaxially grown magnetic tunnel junctions (MTJs) with a stacking structure of Co{sub 2}MnSi/MgO/CoFe were fabricated. Their tunnel magnetoresistance (TMR) effects were investigated. The TMR ratio and tunnelling conductance characteristics of MTJs were considerably different between those with an MgO barrier prepared using sputtering (SP-MTJ) and those prepared using EB evaporation (EB-MTJ). The EB-MTJ exhibited a very large TMR ratio of 217% at room temperature and 753% at 2 K. The bias voltage dependence of the tunnelling conductance in the parallel magnetic configuration for the EB-MTJ suggests that the observed large TMR ratio at RT results from the coherent tunnelling process through the crystalline MgO barrier. The tunnelling conductance in the anti-parallel magnetic configuration suggests that the large temperature dependence of the TMR ratio results from the inelastic spin-flip tunnelling process.

  20. Acute Cholecystitis

    National Research Council Canada - National Science Library

    Schuld, Jochen; Glanemann, Matthias

    2015-01-01

    The treatment of acute cholecystitis has been controversially discussed in the literature as there are no high-evidence-level data yet for determining the optimal point in time for surgical intervention...

  1. Bronchitis (acute)

    OpenAIRE

    Wark, Peter

    2008-01-01

    Acute bronchitis, with transient inflammation of the trachea and major bronchi, affects over 40/1000 adults a year in the UK. The causes are usually considered to be infective, but only around half of people have identifiable pathogens.The role of smoking or environmental tobacco smoke inhalation in predisposing to acute bronchitis is unclear.A third of people may have longer-term symptoms or recurrence.

  2. Rates of Complications and Secondary Surgeries After In Situ Cubital Tunnel Release Compared With Ulnar Nerve Transposition: A Retrospective Review.

    Science.gov (United States)

    Zhang, Dafang; Earp, Brandon E; Blazar, Philip

    2017-04-01

    The purpose of this study was to contrast the rate and types of complications and secondary surgeries for in situ cubital tunnel release and ulnar nerve transposition. A retrospective cohort study was performed by query of hospital billing records for all patients who underwent cubital tunnel surgery from August 2008 to July 2013, yielding 421 patients. Exclusion criteria were acute trauma, revision surgery, neoplasm, age younger than 18 years, incomplete records, and postoperative follow-up less than 3 months. Of the remaining 234 patients, 147 patients underwent 157 in situ cubital tunnel releases and 87 patients underwent 90 ulnar nerve transpositions. In 157 in situ cubital tunnel releases, there were 6 complications (3.8%), including 3 cases (1.9%) of ulnar nerve instability, 2 cases (1.3%) of postoperative infection, and 1 case (0.6%) of a postoperative seroma. In 90 ulnar nerve transpositions, there were 2 complications (2.2%), including 1 case (1.1%) of postoperative infection and 1 case (1.1%) of medial antebrachial cutaneous nerve injury. The secondary surgery rate was 5.7% overall, 2.5% for in situ cubital tunnel release, and 11.1% for ulnar nerve transposition. Chronic kidney disease was associated with complication after cubital tunnel surgery. Prior trauma to the elbow and ulnar nerve transposition were associated with secondary surgery. The short-term complication rates of cubital tunnel surgery are low (3.2%), but higher for patients with chronic kidney disease. The secondary surgery rate after cubital tunnel surgery was 5.7% overall, but higher for patients with prior elbow trauma and for patients undergoing ulnar nerve transposition. Therapeutic IV. Copyright © 2017 American Society for Surgery of the Hand. Published by Elsevier Inc. All rights reserved.

  3. Scanning tunneling microscope assembly, reactor, and system

    Science.gov (United States)

    Tao, Feng; Salmeron, Miquel; Somorjai, Gabor A

    2014-11-18

    An embodiment of a scanning tunneling microscope (STM) reactor includes a pressure vessel, an STM assembly, and three spring coupling objects. The pressure vessel includes a sealable port, an interior, and an exterior. An embodiment of an STM system includes a vacuum chamber, an STM reactor, and three springs. The three springs couple the STM reactor to the vacuum chamber and are operable to suspend the scanning tunneling microscope reactor within the interior of the vacuum chamber during operation of the STM reactor. An embodiment of an STM assembly includes a coarse displacement arrangement, a piezoelectric fine displacement scanning tube coupled to the coarse displacement arrangement, and a receiver. The piezoelectric fine displacement scanning tube is coupled to the coarse displacement arrangement. The receiver is coupled to the piezoelectric scanning tube and is operable to receive a tip holder, and the tip holder is operable to receive a tip.

  4. Endoscopic release of the cubital tunnel.

    Science.gov (United States)

    Zajonc, Horst; Momeni, Arash

    2014-02-01

    It is safe to say that in situ decompression of the ulnar nerve in cubital tunnel syndrome has been demonstrated to achieve equivalent functional results when compared with more elaborate techniques, such as decompression with nerve transposition. The evolution toward procedures associated with less patient morbidity is reflected by the introduction of endoscopic techniques for the treatment of cubital tunnel syndrome. The authors have incorporated the endoscopic approach as proposed by Hoffmann and Siemionow into their practice and have obtained favorable results. Although the skin incision can frequently be kept to a minimum (<2 cm), superior visualization associated with this approach allows for in situ decompression of the ulnar nerve along a distance of up to 30 cm. Despite the extent of decompression performed, operative morbidity is minimal, with return to full duty being the rule even in manual laborers within 10 to 14 days postoperatively. Copyright © 2014 Elsevier Inc. All rights reserved.

  5. Tunneling spectra of graphene on copper unraveled

    DEFF Research Database (Denmark)

    Zhang, Xin; Stradi, Daniele; Liu, Lei

    2016-01-01

    mechanisms, etc. The interpretation of the spectra can be complicated, however. Specifically for graphene grown on copper, there have been conflicting reports of tunneling spectra. A clear understanding of the mechanisms behind the variability is desired. In this work, we have revealed that the root cause...... of the variability in tunneling spectra is the variation in graphene-substrate coupling under various experimental conditions, providing a salutary perspective on the important role of 2D material-substrate interactions. The conclusions are drawn from measured data and theoretical calculations for monolayer, AB......-stacked bilayer, and twisted bilayer graphene coexisting on the same substrates in areas with and without intercalated oxygen, demonstrating a high degree of consistency. The Van Hove singularities of the twisted graphene unambiguously indicate the Dirac energy between them, lending strong evidence to our...

  6. Review of Potential Wind Tunnel Balance Technologies

    Science.gov (United States)

    Burns, Devin E.; Williams, Quincy L.; Phillips, Ben D.; Commo, Sean A.; Ponder, Jonathon D.

    2016-01-01

    This manuscript reviews design, manufacture, materials, sensors, and data acquisition technologies that may benefit wind tunnel balances for the aerospace research community. Current state-of-the-art practices are used as the benchmark to consider advancements driven by researcher and facility needs. Additive manufacturing is highlighted as a promising alternative technology to conventional fabrication and has the potential to reduce both the cost and time required to manufacture force balances. Material alternatives to maraging steels are reviewed. Sensor technologies including piezoresistive, piezoelectric, surface acoustic wave, and fiber optic are compared to traditional foil based gages to highlight unique opportunities and shared challenges for implementation in wind tunnel environments. Finally, data acquisition systems that could be integrated into force balances are highlighted as a way to simplify the user experience and improve data quality. In summary, a rank ordering is provided to support strategic investment in exploring the technologies reviewed in this manuscript.

  7. Alternative diagnostic technique for carpal tunnel syndrome

    Energy Technology Data Exchange (ETDEWEB)

    Hayakawa, Katsuhiko; Nakane, Takashi [Aiko Orthopaedic Hospital, Nagoya (Japan); Kobayashi, Shigeru; Shibata, Kunio [Fujita Health Univ., Toyoake, Aichi (Japan). School of Medicine

    2002-10-01

    Compressive and entrapment neuropathies are common clinical syndromes characterized by neurologic deficits due to mechanical or dynamic compression of peripheral nerves. However, the definitive diagnosis based on clinical symptoms alone is difficult in many cases, and the electrophysiological diagnostic method is solely used as a supplementary diagnostic method at present. As a new diagnostic method for entrapment neuropathy, the present study investigated the usefulness of gadolinium-enhanced MRI in carpal tunnel syndrome. On enhanced MRI of idiopathic carpal tunnel syndrome, contrast-enhancement in the median nerve was found in 30 of 34 hands (88.2%). Enhanced MRI allows to visualize intraneural edema in the nerve easily on the naked eye. Therefore, this technique supplied useful information for making definitive diagnosis and is promising as a non-invasive diagnostic method for entrapment neuropathy. (author)

  8. SUBSONIC WIND TUNNEL PERFORMANCE ANALYSIS SOFTWARE

    Science.gov (United States)

    Eckert, W. T.

    1994-01-01

    This program was developed as an aid in the design and analysis of subsonic wind tunnels. It brings together and refines previously scattered and over-simplified techniques used for the design and loss prediction of the components of subsonic wind tunnels. It implements a system of equations for determining the total pressure losses and provides general guidelines for the design of diffusers, contractions, corners and the inlets and exits of non-return tunnels. The algorithms used in the program are applicable to compressible flow through most closed- or open-throated, single-, double- or non-return wind tunnels or ducts. A comparison between calculated performance and that actually achieved by several existing facilities produced generally good agreement. Any system through which air is flowing which involves turns, fans, contractions etc. (e.g., an HVAC system) may benefit from analysis using this software. This program is an update of ARC-11138 which includes PC compatibility and an improved user interface. The method of loss analysis used by the program is a synthesis of theoretical and empirical techniques. Generally, the algorithms used are those which have been substantiated by experimental test. The basic flow-state parameters used by the program are determined from input information about the reference control section and the test section. These parameters were derived from standard relationships for compressible flow. The local flow conditions, including Mach number, Reynolds number and friction coefficient are determined for each end of each component or section. The loss in total pressure caused by each section is calculated in a form non-dimensionalized by local dynamic pressure. The individual losses are based on the nature of the section, local flow conditions and input geometry and parameter information. The loss forms for typical wind tunnel sections considered by the program include: constant area ducts, open throat ducts, contractions, constant

  9. Surgical ultrasound-guided carpal tunnel release.

    Science.gov (United States)

    Apard, T; Candelier, G

    2017-10-01

    Ultrasound-guided surgery is a new trend stemming from the introduction of high-frequency linear probes and better quality screens. Surgical treatment of carpal tunnel syndrome is increasingly being performed under ultrasound guidance. Knowledge of musculoskeletal ultrasonography is obviously mandatory. Several types of cutting instruments (miniature knife, Gigli saw or hook) and surgical approaches (wrist or palm) have been described. Ultrasonography allows the wide-awake and local anesthesia with no tourniquet (WALANT) technique to be used in the context of ambulatory patient care. The practitioner must be aware of all the possible intraoperative and postoperative complications, and be able to treat them. The aim of this review is to analyze the literature on the feasibility and outcomes of surgical ultrasound-guided carpal tunnel release, and to compare it to the other validated techniques. Copyright © 2017 SFCM. Published by Elsevier Masson SAS. All rights reserved.

  10. Tunneling of heat: Beyond linear response regime

    Science.gov (United States)

    Walczak, Kamil; Saroka, David

    2018-02-01

    We examine nanoscale processes of heat (energy) transfer as carried by electrons tunneling via potential barriers and molecular interconnects between two heat reservoirs (thermal baths). For that purpose, we use Landauer-type formulas to calculate thermal conductance and quadratic correction to heat flux flowing via quantum systems. As an input, we implement analytical expressions for transmission functions related to simple potential barriers and atomic bridges. Our results are discussed with respect to energy of tunneling electrons, temperature, the presence of resonant states, and specific parameters characterizing potential barriers as well as heat carriers. The simplicity of semi-analytical models developed by us allows to fit experimental data and extract crucial information about the values of model parameters. Further investigations are expected for more realistic transmission functions, while time-dependent aspects of nanoscale heat transfer may be addressed by using the concept of wave packets scattered on potential barriers and point-like defects within regular (periodic) nanostructures.

  11. Geomonitoring in construction of the tunnel

    Directory of Open Access Journals (Sweden)

    Jozef Čížik

    2008-12-01

    Full Text Available A basic element in the decision making process on the adequacy of the support system was a monitoring and analysis process.We consider geomonitoring as continuous monitoring of objects (e.g. of mines, tunnels, machinery, buildings and a lot of constructionsduring the construction or operating phase using geodetic, geotechnical and geophysical methods.Geomonitoring is gaining increasing significance as a result of new safety aspects, from the point of view of immission controlas well as in connection with early warning and alarm systems. Specific areas covered include geological and geotechnical explorationsrequired, construction of tunnels and shafts, design considerations, geomechanical analysis, design of linings, and instrumentationand monitoring.Consequently, monitoring of many of the instrument arrays have to continue for several years after construction. Monitoringprograms must be carried out for well-defined purposes, be well planned, and be supported by competent staff through completionand implementation of results from the monitoring program.

  12. Structural and tunneling properties of Si nanowires

    KAUST Repository

    Montes Muñoz, Enrique

    2013-12-06

    We investigate the electronic structure and electron transport properties of Si nanowires attached to Au electrodes from first principles using density functional theory and the nonequilibrium Green\\'s function method. We systematically study the dependence of the transport properties on the diameter of the nanowires, on the growth direction, and on the length. At the equilibrium Au-nanowire distance we find strong electronic coupling between the electrodes and nanowires, which results in a low contact resistance. With increasing nanowire length we study the transition from metallic to tunneling conductance for small applied bias. For the tunneling regime we investigate the decay of the conductance with the nanowire length and rationalize the results using the complex band structure of the pristine nanowires. The conductance is found to depend strongly on the growth direction, with nanowires grown along the ⟨110⟩ direction showing the smallest decay with length and the largest conductance and current.

  13. Photogrammetry Applied to Wind Tunnel Testing

    Science.gov (United States)

    Liu, Tian-Shu; Cattafesta, L. N., III; Radeztsky, R. H.; Burner, A. W.

    2000-01-01

    In image-based measurements, quantitative image data must be mapped to three-dimensional object space. Analytical photogrammetric methods, which may be used to accomplish this task, are discussed from the viewpoint of experimental fluid dynamicists. The Direct Linear Transformation (DLT) for camera calibration, used in pressure sensitive paint, is summarized. An optimization method for camera calibration is developed that can be used to determine the camera calibration parameters, including those describing lens distortion, from a single image. Combined with the DLT method, this method allows a rapid and comprehensive in-situ camera calibration and therefore is particularly useful for quantitative flow visualization and other measurements such as model attitude and deformation in production wind tunnels. The paper also includes a brief description of typical photogrammetric applications to temperature- and pressure-sensitive paint measurements and model deformation measurements in wind tunnels.

  14. Numerical modeling of tunneling induced ground deformation and its control

    Directory of Open Access Journals (Sweden)

    V B Maji

    2016-12-01

    Full Text Available Tunnelling through cities underlain by soft soil, commonly associated with soil movement around the tunnels and subsequent surface settlement. The predication of ground movement during the tunnelling and optimum support pressure could be based on analytical, empirical or the numerical methods. The commonly used Earth pressure balance (EPB tunneling machines, uses the excavated soil in a pressurised head chamber to apply a support pressure to the tunnel face during excavation. This face pressure is a critical responsibility in EPB tunnelling because as the varying pressure can lead to collapse of the face. The objective of the present study is to evalute the critical supporting face pressure and grout pressure by observing the vertical deformation and horizontal displacement of soil body during tunneling. The face pressure and grout pressures were varied to see how they might influence the magnitude of surface settlements/heave. A numerical model using PLAXIS-3D tunnel has been developed to analyse the soil movement around the tunnel that includes various geotechnical conditions. The ground surrounding the tunnel found to be very sensitive to the face pressure and grout pressure in terms of surface settlement and collapse of the soil body.

  15. Fire safety case study of a railway tunnel: Smoke evacuation

    Directory of Open Access Journals (Sweden)

    van Maele Karim

    2007-01-01

    Full Text Available When a fire occurs in a tunnel, it is of great importance to assure the safety of the occupants of the tunnel. This is achieved by creating smoke-free spaces in the tunnel through control of the smoke gases. In this paper, results are presented of a study concerning the fire safety in a real scale railway tunnel test case. Numerical simulations are performed in order to examine the possibility of natural ventilation of smoke in inclined tunnels. Several aspects are taken into account: the length of the simulated tunnel section, the slope of the tunnel and the possible effects of external wind at one portal of the tunnel. The Fire Dynamics Simulator of the National Institute of Standards and Technology, USA, is applied to perform the simulations. The simulations show that for the local behavior of the smoke during the early stages of the fire, the slope of the tunnel is of little importance. Secondly, the results show that external wind and/or pressure conditions have a large effect on the smoke gases inside the tunnel. Finally, some idea for the value of the critical ventilation velocity is given. The study also shows that computational fluid dynamics calculations are a valuable tool for large scale, real life complex fire cases. .

  16. Applicability of tunnel boring Machine and its expert system. Tunnel kusshinki no tekiyosei to expert system

    Energy Technology Data Exchange (ETDEWEB)

    Okubo, S. (Univ. of Tokyo, Tokyo (Japan). Faculty of Engineering)

    1990-06-11

    A tunnel boring machine (TBM) shows extreme lowering in mean penetration rate if it is not properly applied and used, therefore, it is required to discuss the applicability of TBM in advance. In this papaer, the work results presented up to now and knowledge concerning to TBM performances are collected and implemented in a computer program which is called an expert system for applicability of TBM. In this expert system, input parameters are tunnel length, tunnel diameter, maximum curvature, dip, uniaxial compressive strength etc., and penetration rate, normal force, rolling force etc. are deduced together with the appraisal and recommendation for users. Through the several case studies, it was found that the developed expert system gives the appropriate results specially for the tunnels excavated in North America and Europe. In cases of tunnels excavated in Japan, the estimated penetration rate is far less than the actual result. Consideration for complicated environments and surroundings differing from country to country may be remained for future. 31 refs., 4 figs., 6 tabs.

  17. Exhibition of tunnel coupling of negatively charged dangling bonds on Si Surface Using Scanning Tunneling Microscope

    Science.gov (United States)

    Haider, M. Baseer; Livadaru, L.; Pitters, J.; Wolkow, R.

    2011-03-01

    We have performed Scanning tunneling microscopy study of hydrogen terminated Si (100). We will show that single Si atoms in a solid state environment can be served as quantum dots. These negatively charged quantum dots can be tunnel coupled to the nearby Si quantum dots. We will demonstrate that this tunnel coupling can be controlled by adjusting the separation between the two Si atomic quantum dots. Moreover electron occupation in the tunnel coupled Si quantum dots can be controlled. We have used this tunnel coupling effect of Si atomic quantum dots to fabricate Quantum Cellular Automata Cells. Quantum Cellular Automata are used to transmit binary information through electrostatic interaction between adjacent cells without the transfer of charge from one cell to the next. Devices based on Quantum Cellular Automata will consume much less power compared to the conventional transistor based devices. Moreover, since there is no transfer of charge so power dissipation during its operation is minimal compared to conventional semiconductor devices. This Si based Quantum Cellular Automat Cell works at room temperature.

  18. New Tunneling Features in Polar III-Nitride Resonant Tunneling Diodes

    Directory of Open Access Journals (Sweden)

    Jimy Encomendero

    2017-10-01

    Full Text Available For the past two decades, repeatable resonant tunneling transport of electrons in III-nitride double barrier heterostructures has remained elusive at room temperature. In this work we theoretically and experimentally study III-nitride double-barrier resonant tunneling diodes (RTDs, the quantum transport characteristics of which exhibit new features that are unexplainable using existing semiconductor theory. The repeatable and robust resonant transport in our devices enables us to track the origin of these features to the broken inversion symmetry in the uniaxial crystal structure, which generates built-in spontaneous and piezoelectric polarization fields. Resonant tunneling transport enabled by the ground state as well as by the first excited state is demonstrated for the first time over a wide temperature window in planar III-nitride RTDs. An analytical transport model for polar resonant tunneling heterostructures is introduced for the first time, showing a good quantitative agreement with experimental data. From this model we realize that tunneling transport is an extremely sensitive measure of the built-in polarization fields. Since such electric fields play a crucial role in the design of electronic and photonic devices, but are difficult to measure, our work provides a completely new method to accurately determine their magnitude for the entire class of polar heterostructures.

  19. New Tunneling Features in Polar III-Nitride Resonant Tunneling Diodes

    Science.gov (United States)

    Encomendero, Jimy; Faria, Faiza Afroz; Islam, S. M.; Protasenko, Vladimir; Rouvimov, Sergei; Sensale-Rodriguez, Berardi; Fay, Patrick; Jena, Debdeep; Xing, Huili Grace

    2017-10-01

    For the past two decades, repeatable resonant tunneling transport of electrons in III-nitride double barrier heterostructures has remained elusive at room temperature. In this work we theoretically and experimentally study III-nitride double-barrier resonant tunneling diodes (RTDs), the quantum transport characteristics of which exhibit new features that are unexplainable using existing semiconductor theory. The repeatable and robust resonant transport in our devices enables us to track the origin of these features to the broken inversion symmetry in the uniaxial crystal structure, which generates built-in spontaneous and piezoelectric polarization fields. Resonant tunneling transport enabled by the ground state as well as by the first excited state is demonstrated for the first time over a wide temperature window in planar III-nitride RTDs. An analytical transport model for polar resonant tunneling heterostructures is introduced for the first time, showing a good quantitative agreement with experimental data. From this model we realize that tunneling transport is an extremely sensitive measure of the built-in polarization fields. Since such electric fields play a crucial role in the design of electronic and photonic devices, but are difficult to measure, our work provides a completely new method to accurately determine their magnitude for the entire class of polar heterostructures.

  20. Tunnels: different construction methods and its use for pipelines installation

    Energy Technology Data Exchange (ETDEWEB)

    Mattos, Tales; Soares, Ana Cecilia; Assis, Slow de; Bolsonaro, Ralfo; Sanandres, Simon [Petroleo do Brasil S.A. (PETROBRAS), Rio de Janeiro, RJ (Brazil)

    2009-07-01

    In a continental dimensions country like Brazil, the pipeline modal faces the challenge of opening ROW's in the most different kind of soils with the most different geomorphology. To safely fulfill the pipeline construction demand, the ROW opening uses all techniques in earthworks and route definition and, where is necessary, no digging techniques like horizontal directional drilling, micro tunneling and also full size tunnels design for pipelines installation in high topography terrains to avoid geotechnical risks. PETROBRAS has already used the tunnel technique to cross higher terrains with great construction difficult, and mainly to make it pipeline maintenance and operation easier. For the GASBOL Project, in Aparados da Serra region and in GASYRG, in Bolivia, two tunnels were opened with approximately 700 meters and 2,000 meters each one. The GASBOL Project had the particularity of being a gallery with only one excavation face, finishing under the hill and from this point was drilled a vertical shaft was drilled until the top to install the pipeline section, while in GASYRG Project the tunnel had two excavation faces. Currently, two projects are under development with tunnels, one of then is the Caraguatatuba-Taubate gas pipeline (GASTAU), with a 5 km tunnel, with the same concepts of the GASBOL tunnel, with a gallery to be opened with the use of a TBM (Tunneling Boring Machine), and a shaft to the surface, and the gas pipeline Cabiunas-Reduc III (GASDUC III) project is under construction with a 3.7 km tunnel, like the GASYRG tunnel with two faces. This paper presents the main excavation tunneling methods, conventional and mechanized, presenting the most relevant characteristics from both and, in particular, the use of tunnels for pipelines installation. (author)

  1. Carpal tunnel syndrome in spinal patients

    OpenAIRE

    Zmeškalová, Petra

    2007-01-01

    The aim of this work is confirming of incidence carpal tunnel syndrom in patients with spinal cord lesion. This ailment stem from repetitive loading of hands on propulsion of mechanical wheelchair. Work contains the causes of biginning, risk factors for patients, prevention, conservative and operation therapy. Thesis involves characteristic of patient after spinal cord injury, seat and wheelchair propulsion. The practice task contains case report of patient and suggestion of therapy for her. ...

  2. High-performance single nanowire tunnel diodes.

    Science.gov (United States)

    Wallentin, Jesper; Persson, Johan M; Wagner, Jakob B; Samuelson, Lars; Deppert, Knut; Borgström, Magnus T

    2010-03-10

    We demonstrate single nanowire tunnel diodes with room temperature peak current densities of up to 329 A/cm(2). Despite the large surface to volume ratio of the type-II InP-GaAs axial heterostructure nanowires, we measure peak to valley current ratios (PVCR) of up to 8.2 at room temperature and 27.6 at liquid helium temperature. These sub-100-nm-diameter structures are promising components for solar cells as well as electronic applications.

  3. Cubital tunnel release using local anesthesia.

    Science.gov (United States)

    Huq, Nasim S; Ahmed, Naweed; Razeghi, Mehdi

    2013-10-01

    This article discusses an alternative approach to general anesthesia with the use of local anesthesia in minor operating procedure suites when performing in situ decompression of cubital tunnel syndrome for those patients who have mild to moderately severe symptoms and for those who fail to respond to conservative measures. Anterior transposition can easily be performed in the same setting if indicated all with local anesthesia. Copyright © 2013 Elsevier Inc. All rights reserved.

  4. The Emergent Universe scheme and tunneling

    Energy Technology Data Exchange (ETDEWEB)

    Labraña, Pedro [Departamento de Física, Universidad del Bío-Bío, Avenida Collao 1202, Casilla 5-C, Concepción, Chile and Departament d' Estructura i Constituents de la Matèria and Institut de Ciències del Cosmos, Universitat (Spain)

    2014-07-23

    We present an alternative scheme for an Emergent Universe scenario, developed previously in Phys. Rev. D 86, 083524 (2012), where the universe is initially in a static state supported by a scalar field located in a false vacuum. The universe begins to evolve when, by quantum tunneling, the scalar field decays into a state of true vacuum. The Emergent Universe models are interesting since they provide specific examples of non-singular inflationary universes.

  5. Shock Tunnel Tests of Arched Wall Panels

    Science.gov (United States)

    1974-07-01

    Post-test photographs of this test are given in Figures A-3 A and B. Figure A-3 A shows the amount of debris which landed in the casement a...spreading debris to 80 feet (the far wall of the casement ) as shown in the post-test photograph in Figure A-7. Displacement gauge data...10 psi) . The wall failed atastrophically, with debris scattered throughout the tunnel and casement area. Approxi- mately 10 percent

  6. Trophic ulcers in the carpal tunnel syndrome

    Directory of Open Access Journals (Sweden)

    Abelardo Q.-C. Araújo

    1993-09-01

    Full Text Available A patient with carpal tunnel syndrome (CTS and trophic ulcers is described. Despite the healing of the ulcers after surgery for CTS, the severe sensory deficit and the electrophysiological tests have not shown any significant improvement. We think these findings argue against the hypothesis of the sensory deficit being responsible for the trophic ulcers. We favor a major role for the sympathetic disturbances as the main cause for those lesions.

  7. Rehabilitation of the carpal tunnel syndrome

    OpenAIRE

    Chorvátová, Magdaléna

    2010-01-01

    In the theoretical part the thesis gathers basic information on carpal tunnel syndrome (CTS) - its etiology, pathophysiology and clinical picture. The thesis further describes the anatomy and function of hand following the CTS, the diagnosis of disease and treatment options. The thesis also presents possibilities of prevention when working with computers. In the practical part the thesis describes a case of a patient with the CTS disease and suggests using an appropriate treatment methods to ...

  8. Scattering Effects in Proximity Effect Tunneling Spectroscopy.

    Science.gov (United States)

    Gai, Wei

    PETS (Proximity Effect Tunneling Spectroscopy) technique has been applied to Niobium/Yttrium and Niobium/Lutetium bilayers. We have determined electron - phonon interaction parameter lambda_{rm e -ph} is 0.55 for Yttrium and 0.67 for Lutetium. Spin fluctuations parameter lambda_{ rm S} is 0.20 for Yttrium and 0.33 for Lutetium. We found that the large spin fluctuations in Yttrium and Lutetium has responsibility to the absence of superconductivity in them. Our results have given a reasonable explanation of high superconducting transition temperature in them under high pressure. The large reflection coefficient and strong diffuse scattering at Nb/Y and Nb/Lu interface has been discovered and it should have strong influence on the transport properties of metallic superlattices. From the modeling study of elastic scattering in proximity effect tunnel junctions, we have explained why some conventional made high {rm T_{C}} superconducting tunnel junctions give ideal like characteristics in the gap region but variable strength phonon structures in the phonon region.

  9. Endoscopic cubital tunnel release: a systematic review.

    Science.gov (United States)

    Smeraglia, Francesco; Del Buono, Angelo; Maffulli, Nicola

    2015-01-01

    Theoretical advantages of endoscopic cubital tunnel release are the short incision, lower risk of nerve damage, reduced manipulation of the nerve and possible faster recovery. We systematically searched Medline (PubMed), Web of Science and Scopus databases using the following keywords: 'endoscopic ulnar nerve', 'endoscopic cubital nerve', 'endoscopic ulnar compression' and 'endoscopic ulnar neuropathy'. Twenty-one studies were included in this review. The quality of the studies was assessed using the Coleman Methodological Score. Endoscopic release is effective for cubital tunnel entrapment and allows adequate visualization of the site of entrapment. There is a negative association between the severity of the compression and reported outcomes. Injury to the medial branch of the antebrachial cutaneous nerve is less frequent thanks to the limited dissection. The most frequent complication is the development of a hematoma. It is unclear whether ulnar nerve instability is a contraindication to simple decompression. The shorter time to return to work and the cosmetic appearance of the scar can be considered advantages of the endoscopic technique. There is a need to perform randomized clinical trials with common and validated scoring system with a longer duration of follow-up. The literature pertinent to endoscopic cubital tunnel release is lacking in the evaluation of the learning curve. Further investigations are necessary to assess the role of ulnar nerve instability. © The Author 2015. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  10. Outcomes of open carpal tunnel decompression.

    Science.gov (United States)

    Nanavati, Nikhil; Walker-Bone, Karen; Stanworth, Helen; Williams, Christopher

    2013-02-15

    Carpal tunnel syndrome (CTS) is the commonest peripheral neuropathy in the UK. The aim of this study was to characterise the satisfaction and evaluate the symptoms of postoperative patients having undergone open carpal tunnel decompression. A questionnaire comprising of 6 sections was sent to 241 eligible participants. Subjects were asked to provide their demographic information and to quantify preoperative and postoperative numbness and tingling. The target population was also asked to indicate areas of postoperative numbness and tingling on a Katz hand diagram. Symptom severity and quality of life scores were also assessed. This study received 89 usable responses. From analysis of the Katz hand diagrams if was possible to distinguish that 17 subjects (19.1%) had 'persistent' symptoms following carpal tunnel decompression and 72 subjects (80.9%) showed signs of symptomatic improvement. The 17 individuals with persistent symptoms were further assessed for significance between variables. Of these, most were of older age, mainly female, unemployed, with lower mental health and vitality scores. With significance testing, it was shown that lower mental health scores may contribute to a poorer response to surgery (p=0.096). Most subjects experienced a positive response to surgical intervention, however, it may be necessary to screen patients for signs of depression before undertaking any surgery. By taking a more holistic preoperative assessment and aiding patients to seek treatment for any mental health conditions, this study postulates that outcomes of open carpal decompression could be improved.

  11. Hyperventilation provokes symptoms of carpal tunnel syndrome.

    Science.gov (United States)

    Aslam, U; Afzal, S; Syed, Shakir

    2012-01-01

    Hyperventilation causes respiratory alkalosis. The nervous system is more excitable in alkalosis. This phenomenon can be observed as paraesthesia in fingers and toes as well as around the lips in anxious patients breathing rapidly. We wanted to test this phenomenon on already irritable nerves like the median nerve in carpal tunnel syndrome (CTS). We deployed 50 patients who came in to the day case unit for carpal tunnel decompression with electro-physiologically proven diagnosis. We devised a test whereby patients were made to hyperventilate under prescribed conditions and repeated Phalen's test and Tinel's sign for comparison. These were compared with a control group chosen randomly among hospital staff. 86% patients had a positive result which was just behind Phalen's test in sensitivity. It was also 100% specific as there were no false positives. Hyperventilation is a phenomenon which provokes carpal tunnel syndrome. Its clinical value remains to be seen due to cumbersome method and probable patient non-compliance but it is a new discovery. It may be useful in other irritable-nerve-syndromes as a test to add to our available armament. It may be an additional factor or a primary reason for nocturnal paraesthesias in CTS patients.

  12. Energy Optimization of Road Tunnel Lighting Systems

    Directory of Open Access Journals (Sweden)

    Ferdinando Salata

    2015-07-01

    Full Text Available A road tunnel is an enclosed and covered infrastructure for the vehicular traffic. Its lighting system provides 24 h of artificial sources only, with a higher amount of electric power used during the day. Due to safety reasons, when there is natural lighting outside the tunnel, the lighting levels in the stretches right after the entrance and before the exit must be high, in order to guide the driver’s eye towards the middle of the tunnel where the luminance must guarantee safe driving, avoid any over-dimensioning of the lighting systems, and produce energy savings. Such effects can be reached not only through the technological advances in the field of artificial lighting sources with high luminous efficiency, but also through new materials for road paving characterized by a higher reflection coefficient than other ordinary asphalts. This case study examines different technical scenarios, analyzing and comparing possible energy and economic savings. Traditional solutions are thus compared with scenarios suggesting the solutions previously mentioned. Special asphalts are interesting from an economic point of view, whereas the high costs of LED sources nowadays represent an obstacle for their implementation.

  13. Wind tunnel test of musi VI bridge

    Science.gov (United States)

    Permata, Robby; Andika, Matza Gusto; Syariefatunnisa, Risdhiawan, Eri; Hermawan, Budi; Noordiana, Indra

    2017-11-01

    Musi VI Bridge is planned to cross the Musi River in Palembang City, South Sumatera Province, Indonesia. The main span is a steel arch type with 200 m length and side span length is 75 m. Finite element analysis results showed that the bridge has frequency ratio for torsional and heaving mode (torsional frequency/heaving frequency)=1.14. This close to unity value rises concern about aerodynamic behaviour and stability of the bridge deck under wind loading. Sectional static and free vibration wind tunnel test were performed to clarify this phenomena in B2TA3 facility in Serpong, Indonesia. The test followed the draft of Guide of Wind Tunnel Test for Bridges developed by Indonesian Ministry of Public Works. Results from wind tunnel testing show that the bridge is safe from flutter instability and no coupled motion vibration observed. Therefore, low value of frequency ratio has no effect to aerodynamic behaviour of the bridge deck. Vortex-induced vibration in heaving mode occurred in relatively low wind velocity with permissible maximum amplitude value.

  14. Resonant electron tunnelling assisted by charged domain walls in multiferroic tunnel junctions

    Science.gov (United States)

    Sanchez-Santolino, Gabriel; Tornos, Javier; Hernandez-Martin, David; Beltran, Juan I.; Munuera, Carmen; Cabero, Mariona; Perez-Muñoz, Ana; Ricote, Jesus; Mompean, Federico; Garcia-Hernandez, Mar; Sefrioui, Zouhair; Leon, Carlos; Pennycook, Steve J.; Muñoz, Maria Carmen; Varela, Maria; Santamaria, Jacobo

    2017-07-01

    The peculiar features of domain walls observed in ferroelectrics make them promising active elements for next-generation non-volatile memories, logic gates and energy-harvesting devices. Although extensive research activity has been devoted recently to making full use of this technological potential, concrete realizations of working nanodevices exploiting these functional properties are yet to be demonstrated. Here, we fabricate a multiferroic tunnel junction based on ferromagnetic La0.7Sr0.3MnO3 electrodes separated by an ultrathin ferroelectric BaTiO3 tunnel barrier, where a head-to-head domain wall is constrained. An electron gas stabilized by oxygen vacancies is confined within the domain wall, displaying discrete quantum-well energy levels. These states assist resonant electron tunnelling processes across the barrier, leading to strong quantum oscillations of the electrical conductance.

  15. Strain-enhanced tunneling magnetoresistance in MgO magnetic tunnel junctions.

    Science.gov (United States)

    Loong, Li Ming; Qiu, Xuepeng; Neo, Zhi Peng; Deorani, Praveen; Wu, Yang; Bhatia, Charanjit S; Saeys, Mark; Yang, Hyunsoo

    2014-09-30

    While the effects of lattice mismatch-induced strain, mechanical strain, as well as the intrinsic strain of thin films are sometimes detrimental, resulting in mechanical deformation and failure, strain can also be usefully harnessed for applications such as data storage, transistors, solar cells, and strain gauges, among other things. Here, we demonstrate that quantum transport across magnetic tunnel junctions (MTJs) can be significantly affected by the introduction of controllable mechanical strain, achieving an enhancement factor of ~2 in the experimental tunneling magnetoresistance (TMR) ratio. We further correlate this strain-enhanced TMR with coherent spin tunneling through the MgO barrier. Moreover, the strain-enhanced TMR is analyzed using non-equilibrium Green's function (NEGF) quantum transport calculations. Our results help elucidate the TMR mechanism at the atomic level and can provide a new way to enhance, as well as tune, the quantum properties in nanoscale materials and devices.

  16. Aeroservoelastic Wind-Tunnel Test of the SUGAR Truss Braced Wing Wind-Tunnel Model

    Science.gov (United States)

    Scott, Robert C.; Allen, Timothy J.; Funk, Christie J.; Castelluccio, Mark A.; Sexton, Bradley W.; Claggett, Scott; Dykman, John; Coulson, David A.; Bartels, Robert E.

    2015-01-01

    The Subsonic Ultra Green Aircraft Research (SUGAR) Truss-Braced Wing (TBW) aeroservoelastic (ASE) wind-tunnel test was conducted in the NASA Langley Transonic Dynamics Tunnel (TDT) and was completed in April, 2014. The primary goals of the test were to identify the open-loop flutter boundary and then demonstrate flutter suppression. A secondary goal was to demonstrate gust load alleviation (GLA). Open-loop flutter and limit cycle oscillation onset boundaries were identified for a range of Mach numbers and various angles of attack. Two sets of control laws were designed for the model and both sets of control laws were successful in suppressing flutter. Control laws optimized for GLA were not designed; however, the flutter suppression control laws were assessed using the TDT Airstream Oscillation System. This paper describes the experimental apparatus, procedures, and results of the TBW wind-tunnel test. Acquired system ID data used to generate ASE models is also discussed.2 study.

  17. A single institutional experience of conversion of non-tunneled to tunneled hemodialysis catheters: a comparison to de novo placement.

    Science.gov (United States)

    Bajaj, Sunil Kumar; Ciacci, Joseph; Kirsch, Matthias; Ebersole, John D

    2013-12-01

    To compare the outcomes of conversion of non-tunneled to tunneled hemodialysis catheters with de novo placement of tunneled catheters and to determine the effect of time to conversion of non-tunneled to tunneled catheters on the incidence of complications. A retrospective data analyses was performed on 1,154 patients who had de novo placement of tunneled hemodialysis catheters (control group) and 254 patients who underwent conversion of non-tunneled to tunneled catheters (study group). The outcomes including technical complications, infection, and catheter dysfunction were compared between the two groups. The technical success rate was 100 % in both the groups with no complications recorded at the time of procedure or within 24 h of insertion. The most common complication encountered in both the groups was catheter dysfunction (15.6 % in controls and 18.1 % in study). Infection rates/100 catheter days for the control and study groups were 0.17 and 0.19, respectively. Infection-free survival was not statistically different between the two groups. The time spent with non-tunneled catheter prior to conversion did not significantly alter the rates of catheter dysfunction and infection in the study group. The efficacy and safety of conversion of non-tunneled to tunneled hemodialysis catheters are similar to de novo placement with no difference in the rates of technical success, catheter dysfunction, or infection. However, the exchange of non-tunneled to tunneled catheter can help in preservation of veins for future vascular access, which is of vital importance in patients with chronic renal disease.

  18. Fire protection for high speed line tunnels; Risk analysis and exceptional robotic application results

    NARCIS (Netherlands)

    Linde, F.W.J. van de; Gijsbers, F.B.J.; Klok, G.J.

    2006-01-01

    The Green Hart Tunnel in The Netherlands is a 7 km long high speed railway tunnel with an exterior diameter of 14.5 metres. A separation wall devides the tunnel into two single tubes. High speed trains will pass the tunnel at speeds of more than 300 kph. Inside the tunnel 200,000 m2 fire resistant

  19. Ten years of bored tunnels in the Netherlands : Part II: Structural issues

    NARCIS (Netherlands)

    Bakker, K.J.; Bezuijen, A.

    2008-01-01

    In 1997 for the first time construction of bored tunnels in the Netherlands soft soil was undertaken. Before that date essentially only immersed tunnels and cut-and-cover tunnels were constructed in the Netherlands. The first two bored tunnels were Pilot Projects, the 2nd Heinenoord tunnel and the

  20. Structural monitoring of metro infrastructure during shield tunneling construction.

    Science.gov (United States)

    Ran, L; Ye, X W; Ming, G; Dong, X B

    2014-01-01

    Shield tunneling construction of metro infrastructure will continuously disturb the soils. The ground surface will be subjected to uplift or subsidence due to the deep excavation and the extrusion and consolidation of the soils. Implementation of the simultaneous monitoring with the shield tunnel construction will provide an effective reference in controlling the shield driving, while how to design and implement a safe, economic, and effective structural monitoring system for metro infrastructure is of great importance and necessity. This paper presents the general architecture of the shield construction of metro tunnels as well as the procedure of the artificial ground freezing construction of the metro-tunnel cross-passages. The design principles for metro infrastructure monitoring of the shield tunnel intervals in the Hangzhou Metro Line 1 are introduced. The detailed monitoring items and the specified alarming indices for construction monitoring of the shield tunneling are addressed, and the measured settlement variations at different monitoring locations are also presented.

  1. Structural Monitoring of Metro Infrastructure during Shield Tunneling Construction

    Directory of Open Access Journals (Sweden)

    L. Ran

    2014-01-01

    Full Text Available Shield tunneling construction of metro infrastructure will continuously disturb the soils. The ground surface will be subjected to uplift or subsidence due to the deep excavation and the extrusion and consolidation of the soils. Implementation of the simultaneous monitoring with the shield tunnel construction will provide an effective reference in controlling the shield driving, while how to design and implement a safe, economic, and effective structural monitoring system for metro infrastructure is of great importance and necessity. This paper presents the general architecture of the shield construction of metro tunnels as well as the procedure of the artificial ground freezing construction of the metro-tunnel cross-passages. The design principles for metro infrastructure monitoring of the shield tunnel intervals in the Hangzhou Metro Line 1 are introduced. The detailed monitoring items and the specified alarming indices for construction monitoring of the shield tunneling are addressed, and the measured settlement variations at different monitoring locations are also presented.

  2. A review on all-perovskite multiferroic tunnel junctions

    Directory of Open Access Journals (Sweden)

    Yuewei Yin

    2017-12-01

    Full Text Available Although the basic concept was proposed only about 10 years ago, multiferroic tunnel junctions (MFTJs with a ferroelectric barrier sandwiched between two ferromagnetic electrodes have already drawn considerable interests, driven mainly by its potential applications in multi-level memories and electric field controlled spintronics. The purpose of this article is to review the recent progress of all-perovskite MFTJs. Starting from the key functional properties of the tunneling magnetoresistance, tunneling electroresistance, and tunneling electromagnetoresistance effects, we discuss the main origins of the tunneling electroresistance effect, recent progress in achieving multilevel resistance states in a single device, and the electrical control of spin polarization and transport through the ferroelectric polarization reversal of the tunneling barrier.

  3. Statistical approach to tunneling time in attosecond experiments

    Science.gov (United States)

    Demir, Durmuş; Güner, Tuğrul

    2017-11-01

    Tunneling, transport of particles through classically forbidden regions, is a pure quantum phenomenon. It governs numerous phenomena ranging from single-molecule electronics to donor-acceptor transition reactions. The main problem is the absence of a universal method to compute tunneling time. This problem has been attacked in various ways in the literature. Here, in the present work, we show that a statistical approach to the problem, motivated by the imaginary nature of time in the forbidden regions, lead to a novel tunneling time formula which is real and subluminal (in contrast to various known time definitions implying superluminal tunneling). In addition to this, we show explicitly that the entropic time formula is in good agreement with the tunneling time measurements in laser-driven He ionization. Moreover, it sets an accurate range for long-range electron transfer reactions. The entropic time formula is general enough to extend to the photon and phonon tunneling phenomena.

  4. Microwave-induced co-tunneling in single electron tunneling transistors

    DEFF Research Database (Denmark)

    Ejrnaes, M.; Savolainen, M.; Manscher, M.

    2002-01-01

    The influence of microwaves on the co-tunneling in single electron tunneling transistors has been investigated as function of frequency and power in the temperature range from 150 to 500 mK. All 20 low frequency connections and the RF line were filtered, and the whole cryostat was suspended...... fixed at maximum Coulomb blockade. With the microwave signal applied to one side of the transistor, we find that the conductance increases linearly with T-2 and microwave power. (C) 2002 Elsevier Science B.V. All rights reserved....

  5. Tunnelling anisotropic magnetoresistance due to antiferromagnetic CoO tunnel barriers.

    Science.gov (United States)

    Wang, K; Sanderink, J G M; Bolhuis, T; van der Wiel, W G; de Jong, M P

    2015-10-21

    A new approach in spintronics is based on spin-polarized charge transport phenomena governed by antiferromagnetic (AFM) materials. Recent studies have demonstrated the feasibility of this approach for AFM metals and semiconductors. We report tunneling anisotropic magnetoresistance (TAMR) due to the rotation of antiferromagnetic moments of an insulating CoO layer, incorporated into a tunnel junction consisting of sapphire(substrate)/fcc-Co/CoO/AlOx/Al. The ferromagnetic Co layer is exchange coupled to the AFM CoO layer and drives rotation of the AFM moments in an external magnetic field. The results may help pave the way towards the development of spintronic devices based on AFM insulators.

  6. Quantum tunneling splittings from path-integral molecular dynamics

    Science.gov (United States)

    Mátyus, Edit; Wales, David J.; Althorpe, Stuart C.

    2016-03-01

    We illustrate how path-integral molecular dynamics can be used to calculate ground-state tunnelling splittings in molecules or clusters. The method obtains the splittings from ratios of density matrix elements between the degenerate wells connected by the tunnelling. We propose a simple thermodynamic integration scheme for evaluating these elements. Numerical tests on fully dimensional malonaldehyde yield tunnelling splittings in good overall agreement with the results of diffusion Monte Carlo calculations.

  7. Experience in design and construction of the Log tunnel

    Directory of Open Access Journals (Sweden)

    Jovičić Vojkan

    2017-09-01

    Full Text Available A twin highway Log tunnel is a part of a new motorway connection between Maribor and Zagreb, section Draženci-Gruškovje, which is located towards the border crossing between Slovenia and Croatia. The tunnel is currently under construction, and only the excavation works have been completed during the writing of this paper. The terrain in the area of the Log tunnel is diverse, and the route of the highway in its vicinity is characterised by deep excavations, bridges or viaducts. The Log tunnel is approximately 250 m long, partly constructed as a gallery. The geological conditions are dominated by Miocene base rock, featuring layers of well-connected clastic rocks, which are covered by diluvium clays, silts, sands and gravels of different thicknesses. Due to the short length of the tunnel, the usual separation of the motorway route to the left and the right tunnel axes was not carried out. Thus, the tunnel was constructed with an intermediate pillar and was designed as a three-lane tunnel, including the stopping lane. The construction of the tunnel was carried out using the New Austrian tunnelling method (NATM, in which the central adit was excavated first and the intermediate pillar was constructed within it. The excavation of the main tubes followed and was divided into the top heading, bench and the invert, enabling the intermediate pillar to take the load off the top heading of both tubes. The secondary lining of the tunnel is currently under construction. The experience of the tunnel construction gathered so far is presented in the paper. The main emphasis is on the construction of the intermediate pillar, which had to take the significant and asymmetrical ground load.

  8. Kinesiotherapy and physical therapy for carpal tunnel syndrome

    OpenAIRE

    Sochová, Jitka

    2013-01-01

    Author: Jitka Sochová Institution: Department of Rehabilitation Medicine The Faculty of Medicine in Hradec Králové Title: Kinesiotherapy and physical therapy for carpal tunnel syndrome Supervisor: Mgr. Zuzana Hamarová Pages: 128 Inserts: 7 The year of presentation: 2013 Keywords: Carpal tunnel, rehabilitation therapy, entrapment syndromes, electromyography This Bachelor Diploma deals with carpal tunnel syndrome. In theoretical part I focus on anatomy, lead and innervation of the median nerve,...

  9. The Douglas Aerophysics Laboratory Four-Foot Trisonic Wind Tunnel,

    Science.gov (United States)

    This report describes the Four-Foot Trisonic Wind Tunnel and the Douglas Aerophysics Laboratory in which it is located. It also presents the performance and operating characteristics of the tunnel, model support and design considerations for a test, diverse test capabilities, instrumentation and data recording equipment, data processing and presentation, and the customer responsibilities for obtaining optimum planning and performance of wind tunnel tests.

  10. Wrist immobilization after carpal tunnel release: a prospective study

    OpenAIRE

    Martins Roberto S.; Siqueira Mario G.; Simplício Hougelli

    2006-01-01

    This prospective study evaluates the possible advantages of wrist imobilization after open carpal tunnel release comparing the results of two weeks immobilization and no immobilization. Fifty two patients with idiopathic carpal tunnel syndrome were randomly selected in two groups after open carpal tunnel release. In one group (A, n=26) the patients wore a neutral-position wrist splint continuosly for two weeks. In the other group (B, n=26) no wrist immobilization was used. Clinical assessment...

  11. Markovian Geology Prediction Approach and its Application in Mountain Tunnels

    OpenAIRE

    Guan, Zhenchang; Deng, Tao; Du, Saizhao; Li, Bo; Jiang, Yujing

    2012-01-01

    A geology prediction approach based on Markov random process and Bayesian updating procedure is presented in this article. It can dynamically predict the ground conditions ahead of tunnel face in a probabilistic way with very low cost, when the tunnel face advances and new geological information is revealed. The application case study on Chuangshi Tunnel project shows that the prediction results fit the real grounds condition well, especially for the short range ahead of face. This approach c...

  12. Experience in design and construction of the Log tunnel

    Science.gov (United States)

    Jovičić, Vojkan; Goleš, Niko; Tori, Matija; Peternel, Miha; Vajović, Stanojle; Muhić, Elvir

    2017-09-01

    A twin highway Log tunnel is a part of a new motorway connection between Maribor and Zagreb, section Draženci-Gru\\vskovje, which is located towards the border crossing between Slovenia and Croatia. The tunnel is currently under construction, and only the excavation works have been completed during the writing of this paper. The terrain in the area of the Log tunnel is diverse, and the route of the highway in its vicinity is characterised by deep excavations, bridges or viaducts. The Log tunnel is approximately 250 m long, partly constructed as a gallery. The geological conditions are dominated by Miocene base rock, featuring layers of well-connected clastic rocks, which are covered by diluvium clays, silts, sands and gravels of different thicknesses. Due to the short length of the tunnel, the usual separation of the motorway route to the left and the right tunnel axes was not carried out. Thus, the tunnel was constructed with an intermediate pillar and was designed as a three-lane tunnel, including the stopping lane. The construction of the tunnel was carried out using the New Austrian tunnelling method (NATM), in which the central adit was excavated first and the intermediate pillar was constructed within it. The excavation of the main tubes followed and was divided into the top heading, bench and the invert, enabling the intermediate pillar to take the load off the top heading of both tubes. The secondary lining of the tunnel is currently under construction. The experience of the tunnel construction gathered so far is presented in the paper. The main emphasis is on the construction of the intermediate pillar, which had to take the significant and asymmetrical ground load.

  13. Giant tunnel-electron injection in nitrogen-doped graphene

    DEFF Research Database (Denmark)

    Lagoute, Jerome; Joucken, Frederic; Repain, Vincent

    2015-01-01

    Scanning tunneling microscopy experiments have been performed to measure the local electron injection in nitrogen-doped graphene on SiC(000) and were successfully compared to ab initio calculations. In graphene, a gaplike feature is measured around the Fermi level due to a phonon-mediated tunneling...... and at carbon sites. Nitrogen doping can therefore be proposed as a way to improve tunnel-electron injection in graphene....

  14. Manipulation of magnetic skyrmions with a scanning tunneling microscope

    Science.gov (United States)

    Wieser, R.; Shindou, R.; Xie, X. C.

    2017-02-01

    The dynamics of a single magnetic skyrmion in an atomic spin system under the influence of a scanning tunneling microscope is investigated by computer simulations solving the Landau-Lifshitz-Gilbert equation. Two possible scenarios are described: manipulation with aid of a spin-polarized tunneling current and by an electric field created by the scanning tunneling microscope. The dynamics during the creation and annihilation process is studied and the possibility to move single skyrmions is showed.

  15. Acute Pancreatitis

    DEFF Research Database (Denmark)

    Bertilsson, Sara; Håkansson, Anders; Kalaitzakis, Evangelos

    2017-01-01

    Aims: We aimed to evaluate the potential relation between the incidence of (alcoholic and non-alcoholic) acute pancreatitis (AP) and alcohol consumption in the general population, and whether the occurrence of AP shows any seasonal variation, particularly in relation to periods with expected...... consumption in the general population do not appear to be related to changes in the incidence of AP and there are no significant seasonal differences in the occurrence of AP in Sweden. Short summary: The incidence of acute pancreatitis (AP) is increasing, and alcohol is still recognized as one of the most...

  16. InAs/Si Hetero-Junction Nanotube Tunnel Transistors

    OpenAIRE

    Hanna, Amir N.; Fahad, Hossain M.; Hussain, Muhammad M.

    2015-01-01

    Hetero-structure tunnel junctions in non-planar gate-all-around nanowire (GAA NW) tunnel FETs (TFETs) have shown significant enhancement in ?ON? state tunnel current over their all-silicon counterpart. Here we show the unique concept of nanotube TFET in a hetero-structure configuration that is capable of much higher drive current as opposed to that of GAA NW TFETs.Through the use of inner/outer core-shell gates, a single III-V hetero-structured nanotube TFET leverages physically larger tunnel...

  17. Reinventing the PN Junction: Dimensionality Effects on Tunneling Switches

    Science.gov (United States)

    2012-05-11

    state tunneling probability is 10-6. 2.3.2 Conclusion This device exploits a unique heterostructure and surface quantum well to create a new...pn junction describes tunneling [9] within a nanowire or carbon nanotube junction as schematically represented in Figure 6.3(a). Tunneling is...6.5 0D-1D JUNCTION A 0d to 1d junction represents tunneling from a quantum dot to a nanowire as shown in Figure 6.6(a). Our main goal in analyzing

  18. Computational Wind Tunnel: A Design Tool for Rotorcraft Project

    Data.gov (United States)

    National Aeronautics and Space Administration — During initial design studies, parametric variation of vehicle geometry is routine. In addition, rotorcraft engineers traditionally use the wind tunnel to evaluate...

  19. Structural Safety Assessment of Existing Multiarch Tunnel: A Case Study

    Directory of Open Access Journals (Sweden)

    Jinxing Lai

    2017-01-01

    Full Text Available Structural health assessment is one of the key activities in maintaining the performance of a tunnel during its service life. Due to the development of modern detection technology, comprehensive structural health assessment system is being established for operating tunnels. To evaluate the actual operational state of Shitigou tunnel, overall detection of the liner crack, tunnel seepage, and liner void was conducted by employing the modern detection technology, such as crack width monitoring technology, concrete strength monitoring technology, and electromagnetic wave nondestructive monitoring technology. Through the statistical analysis of the detection results, the distribution characteristic, development law, and damage grade of structural defects were obtained. Tunnel liner cracks are mainly located on the middle wall; serious water leakage is encountered on the side wall, middle wall, and vault; the strength of foundation and liner structure of left tunnel does not meet the design requirement; the liner voids are mostly located at the tunnel entrance section, especially, on the tunnel vault; and the proportion of influence factors of structural defects should be considered. The research results presented for this study can serve as references for effective design and health assessment of existing multiarch tunnel projects.

  20. Automatic control study of the icing research tunnel refrigeration system

    Science.gov (United States)

    Kieffer, Arthur W.; Soeder, Ronald H.

    1991-02-01

    The Icing Research Tunnel (IRT) at the NASA Lewis Research Center is a subsonic, closed-return atmospheric tunnel. The tunnel includes a heat exchanger and a refrigeration plant to achieve the desired air temperature and a spray system to generate the type of icing conditions that would be encountered by aircraft. At the present time, the tunnel air temperature is controlled by manual adjustment of freon refrigerant flow control valves. An upgrade of this facility calls for these control valves to be adjusted by an automatic controller. The digital computer simulation of the IRT refrigeration plant and the automatic controller that was used in the simulation are discussed.

  1. Cubital tunnel syndrome: A report of two cases

    Directory of Open Access Journals (Sweden)

    Farhana Ebrahim Suleman

    2012-06-01

    Full Text Available Cubital tunnel syndrome is the second most common peripheral neuropathy of the upper limb. This is due to the anatomy of the tunnel, the physiological changes that the nerve undergoes during elbow flexion, as well as pathological conditions that occur within the tunnel. We present two cases of ulnar neuropathy occurring at the level of the cubital tunnel, demonstrating that this entity may occur owing to an identifiable cause or may show only signal alteration without a visible cause on MRI.

  2. Quantum Tunnelling to the Origin and Evolution of Life.

    Science.gov (United States)

    Trixler, Frank

    2013-08-01

    Quantum tunnelling is a phenomenon which becomes relevant at the nanoscale and below. It is a paradox from the classical point of view as it enables elementary particles and atoms to permeate an energetic barrier without the need for sufficient energy to overcome it. Tunnelling might seem to be an exotic process only important for special physical effects and applications such as the Tunnel Diode, Scanning Tunnelling Microscopy (electron tunnelling) or Near-field Optical Microscopy operating in photon tunnelling mode. However, this review demonstrates that tunnelling can do far more, being of vital importance for life: physical and chemical processes which are crucial in theories about the origin and evolution of life can be traced directly back to the effects of quantum tunnelling. These processes include the chemical evolution in stellar interiors and within the cold interstellar medium, prebiotic chemistry in the atmosphere and subsurface of planetary bodies, planetary habitability via insolation and geothermal heat as well as the function of biomolecular nanomachines. This review shows that quantum tunnelling has many highly important implications to the field of molecular and biological evolution, prebiotic chemistry and astrobiology.

  3. Large magnetocurrents in double-barrier tunneling transistors

    Energy Technology Data Exchange (ETDEWEB)

    Lee, J.H. [Nano Device Research Center, Korea Institute of Science and Technology, Seoul 136-791 (Korea, Republic of); Department of Physics, Korea University, Chochiwon 339-700 (Korea, Republic of); Jun, K.-I. [Nano Device Research Center, Korea Institute of Science and Technology, Seoul 136-791 (Korea, Republic of); Shin, K.-H. [Nano Device Research Center, Korea Institute of Science and Technology, Seoul 136-791 (Korea, Republic of); Park, S.Y. [Department of Physics, Korea University, Chochiwon 339-700 (Korea, Republic of); Hong, J.K. [Department of Physics, Korea University, Chochiwon 339-700 (Korea, Republic of); Rhie, K. [Department of Physics, Korea University, Chochiwon 339-700 (Korea, Republic of)]. E-mail: krhie@korea.ac.kr; Lee, B.C. [Department of Physics, Inha University, Incheon (Korea, Republic of)

    2005-02-01

    Magnetic tunneling transistors (MTT) with double tunneling barriers are fabricated. The structure of the transistor is AFM/FM/I/FM/I/FM/AFM, and ferromagnetic layers serve as the emitter, base and collector. This double-barrier tunneling transistor (DBTT) has an advantage of controlling the potential between the base and collector, compared to the Schottky-barrier-based base and collector of MTT. We found that the collector current density of DBTT is at least 10{sup 3} times larger than that of conventional MTT, since tunneling through AlO{sub x} barrier provides much larger current density than that through Schottky barrier.

  4. Automatic control study of the icing research tunnel refrigeration system

    Science.gov (United States)

    Kieffer, Arthur W.; Soeder, Ronald H.

    1991-01-01

    The Icing Research Tunnel (IRT) at the NASA Lewis Research Center is a subsonic, closed-return atmospheric tunnel. The tunnel includes a heat exchanger and a refrigeration plant to achieve the desired air temperature and a spray system to generate the type of icing conditions that would be encountered by aircraft. At the present time, the tunnel air temperature is controlled by manual adjustment of freon refrigerant flow control valves. An upgrade of this facility calls for these control valves to be adjusted by an automatic controller. The digital computer simulation of the IRT refrigeration plant and the automatic controller that was used in the simulation are discussed.

  5. Pictorial essay: Role of ultrasound in failed carpal tunnel decompression

    Directory of Open Access Journals (Sweden)

    Rajesh Botchu

    2012-01-01

    Full Text Available USG has been used for the diagnosis of carpal tunnel syndrome. Scarring and incomplete decompression are the main causes for persistence or recurrence of symptoms. We performed a retrospective study to assess the role of ultrasound in failed carpal tunnel decompression. Of 422 USG studies of the wrist performed at our center over the last 5 years, 14 were for failed carpal tunnel decompression. Scarring was noted in three patients, incomplete decompression in two patients, synovitis in one patient, and an anomalous muscle belly in one patient. No abnormality was detected in seven patients. We present a pictorial review of USG findings in failed carpal tunnel decompression.

  6. Supersonic and hypersonic quiet tunnel technology at NASA Langley

    Science.gov (United States)

    Wilkinson, S. P.; Anders, S. G.; Chen, F.-J.; Beckwith, I. E.

    1992-01-01

    Quiet tunnel technology at NASA Langley is reviewed focusing on historical background, basic quiet tunnel concepts, design methodology, and significant results. Each of the NASA Langley quiet tunnels and recent flow quality results for a refurbished Mach 6 quiet nozzle are presented. It is concluded that high-speed quiet tunels should be viewed as a required adjunct to computational and experimental tools being developed to explore issues of instability and transition physics. The quiet tunnel technology can produce and maintain an adequately smooth nozzle finish, control settling chamber disturbances, and keep the facility clean and is capable of adequately measuring flow disturbances.

  7. Sediment and Cavitation Erosion Studies through Dam Tunnels

    Directory of Open Access Journals (Sweden)

    Muhammad Abid

    2016-01-01

    Full Text Available This paper presents results of sediment and cavitation erosion through Tunnel 2 and Tunnel 3 of Tarbela Dam in Pakistan. Main bend and main branch of Tunnel 2 and outlet 1 and outlet 3 of Tunnel 3 are concluded to be critical for cavitation and sediment erosion. Studies are also performed for increased sediments flow rate, concluding 5 kg/sec as the critical value for sudden increase in erosion rate density. Erosion rate is concluded to be the function of sediment flow rate and head condition. Particulate mass presently observed is reasonably low, hence presently not affecting the velocity and the flow field.

  8. High tunnels: protection for rather than from insect pests?

    Science.gov (United States)

    Ingwell, Laura L; Thompson, Sarah L; Kaplan, Ian; Foster, Ricky E

    2017-12-01

    High tunnels are a season extension tool creating a hybrid of field and greenhouse growing conditions. High tunnels have recently increased in the USA and thus research on their management is lacking. One purported advantage of these structures is protection from common field pests, but evidence to support this claim is lacking. We compared insect pest populations in high tunnels with field production over two years for three crops: tomato, broccoli and cucumber. Greenhouse pests (e.g. aphids, whiteflies) were more prevalent in high tunnels, compared to field plots. Hornworms (tobacco (Manduca sexta L.) and tomato (M. quinquemaculata Haworth)), a common field pest on tomato, were also more abundant in high tunnels, requiring chemical control while field populations were low. The crucifer caterpillar complex (imported cabbageworm (Pieris rapae L.), diamondback moth (Plutella xylostella L.) and cabbage looper (Trichoplusia ni Hübner)) was also more abundant in high tunnels in 2010. Cucumber beetle (striped (Acalymma vittatum F.) and spotted (Diabrotica undecimpunctata Mannerheim)) densities were higher in high tunnels in 2010 and field plots in 2011. The common assumption that high tunnels offer protection from field pests was not supported. Instead, high tunnel growing conditions may facilitate higher pest populations. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

  9. Superconducting Tunnel Junction Arrays for UV Photon Detection Project

    Data.gov (United States)

    National Aeronautics and Space Administration — An innovative method is described for the fabrication of superconducting tunnel junction (STJ) detector arrays offering true "three dimensional" imaging throughout...

  10. Dielectric breakdown in AlO{sub x} tunnelling barriers

    Energy Technology Data Exchange (ETDEWEB)

    Schaefer, D M; Carara, M; Schelp, L F; Dorneles, L S [Universidade Federal de Santa Maria, Departamento de Fisica, Av. Roraima, 1000, Santa Maria 97105-900, RS (Brazil); Fichtner, P F P, E-mail: lsdorneles@gmail.com [Universidade Federal do Rio Grande do Sul, Instituto de Fisica, Av. Bento Goncalves, 9500, Caixa Postal 15051, Porto Alegre 91501-970, RS (Brazil)

    2011-04-06

    We studied the dielectric breakdown in tunnelling barriers produced by plasma-assisted oxidation of an aluminium surface. The barrier mean height, thickness and the effective tunnelling area were extracted from current versus voltage curves measured at room temperature. The effective tunnelling area ranged from 10{sup -10} to 10{sup -5} cm{sup 2}, corresponding to less than 1% of the geometrical surface of the samples. The estimated electrical field to breakdown agreed with predictions from thermochemical models, and decreased exponentially with the effective tunnelling area.

  11. Highly functional tunnelling devices integrated in 3D

    DEFF Research Database (Denmark)

    Wernersson, Lars-Erik; Lind, Erik; Lindström, Peter

    2003-01-01

    a new type of tunnelling transistor, namely a resonant-tunnelling permeable base transistor. A simple model based on a piece-wise linear approximation is used in Cadence to describe the current-voltage characteristics of the transistor. This model is further introduced into a small signal equivalent...... circuit in order to optimize the performance of the device. In addition to the tunnelling structure below the grating, these transistors may be integrated in 3D by the introduction of another tunnelling structure directly over the metal grating. In the integrated device structure, the gate acts...

  12. Proceedings of the meeting on tunneling reaction and low temperature chemistry, 97 October. Tunneling reaction and quantum medium

    Energy Technology Data Exchange (ETDEWEB)

    Miyazaki, Tetsuo; Aratono, Yasuyuki; Ichikawa, Tsuneki; Shiotani, Masaru [eds.

    1998-02-01

    Present report is the proceedings of the 3rd Meeting on Tunneling Reaction and Low Temperature Chemistry held in Oct. 13 and 14, 1997. The main subject of the meeting is `Tunneling Reaction and Quantum Medium`. In the meeting, the physical and chemical phenomena in the liquid helium such as quantum nucleation, spectroscopy of atoms and molecules, and tunneling abstraction reaction of tritium atom were discussed as the main topics as well as the tunneling reactions in the solid hydrogen and organic compounds. Through the meetings held in 1995, 1996, and 1997, the tunneling phenomena proceeding at various temperatures (room temperature to mK) in the wide fields of chemistry, biology, and physics were discussed intensively and the importance of the tunneling phenomena in the science has been getting clear. The 12 of the presented papers are indexed individually. (J.P.N.)

  13. Proceedings of the meeting on tunneling reaction and low temperature chemistry, 98 August. Tunneling reaction and its theory

    Energy Technology Data Exchange (ETDEWEB)

    Miyazaki, Tetsuo; Aratono, Yasuyuki; Ichikawa, Tsuneki; Shiotani, Masaru [eds.

    1998-10-01

    Present report is the proceedings of the 4th Meeting on Tunneling Reaction and Low Temperature Chemistry held in August 3 and 4, 1998. The main subject of the meeting is `Tunneling Reaction and Its Theory`. In the present meeting the theoretical aspects of tunneling phenomena in the chemical reaction were discussed intensively as the main topics. Ten reports were presented on the quantum diffusion of muon and proton in the metal and H{sub 2}{sup -} anion in the solid para-hydrogen, the theory of tunnel effect in the nuclear reaction and the tunneling reaction in the organic compounds. One special lecture was presented by Prof. J. Kondo on `Proton Tunneling in Solids`. The 11 of the presented papers are indexed individually. (J.P.N.)

  14. In-situ stress amplification due to geological factors in tunnels: The case of Pajares tunnels, Spain

    OpenAIRE

    Hijazo Ramiro, Teresa; González de Vallejo, Luis I.

    2012-01-01

    Geological and geomechanical anisotropies can significantly increase the magnitude of in-situ stress in a rock mass excavated for tunnelling purposes. Four tunnels for the new high-speed railway lines in Pajares in the Cantabrian Mountains, N. Spain, were analysed and significant deformations was found to have occurred in forty specific zones of these tunnels during excavation, requiring much more support than envisaged before construction. Local factors influencing in-situ stress...

  15. Acute Sinusitis

    Science.gov (United States)

    ... Acute sinusitis is mostly caused by the common cold. Unless a bacterial infection develops, most cases resolve within a week to 10 days. In ... sinusitis is most often caused by the common cold, which is a viral infection. In some cases, a bacterial infection develops. Risk factors You may ...

  16. Acute pancreatitis.

    Science.gov (United States)

    Munsell, Melissa A; Buscaglia, Jonathan M

    2010-04-01

    Acute pancreatitis is a common disease most frequently caused by gallstone disease or excess alcohol ingestion. Diagnosis is usually based on characteristic symptoms, often in conjunction with elevated serum pancreatic enzymes. Imaging is not always necessary, but may be performed for many reasons, such as to confirm a diagnosis of pancreatitis, rule out other causes of abdominal pain, elucidate the cause of pancreatitis, or to evaluate for complications such as necrosis or pseudocysts. Though the majority of patients will have mild, self-limiting disease, some will develop severe disease associated with organ failure. These patients are at risk to develop complications from ongoing pancreatic inflammation such as pancreatic necrosis, fluid collections, pseudocysts, and pancreatic duct disruption. Validated scoring systems can help predict the severity of pancreatitis, and thus, guide monitoring and intervention.Treatment of acute pancreatitis involves supportive care with fluid replacement, pain control, and controlled initiation of regular food intake. Prophylactic antibiotics are not recommended in acute pancreatitis if there is no evidence of pancreatic infection. In patients who fail to improve, further evaluation is necessary to assess for complications that require intervention such as pseudocysts or pancreatic necrosis. Endoscopy, including ERCP and EUS, and/or cholecystectomy may be indicated in the appropriate clinical setting. Ultimately, the management of the patient with severe acute pancreatitis will require a multidisciplinary approach. (c) 2010 Society of Hospital Medicine.

  17. Acute Bronchitis.

    Science.gov (United States)

    Kinkade, Scott; Long, Natalie A

    2016-10-01

    Cough is the most common illness-related reason for ambulatory care visits in the United States. Acute bronchitis is a clinical diagnosis characterized by cough due to acute inflammation of the trachea and large airways without evidence of pneumonia. Pneumonia should be suspected in patients with tachypnea, tachycardia, dyspnea, or lung findings suggestive of pneumonia, and radiography is warranted. Pertussis should be suspected in patients with cough persisting for more than two weeks that is accompanied by symptoms such as paroxysmal cough, whooping cough, and post-tussive emesis, or recent pertussis exposure. The cough associated with acute bronchitis typically lasts about two to three weeks, and this should be emphasized with patients. Acute bronchitis is usually caused by viruses, and antibiotics are not indicated in patients without chronic lung disease. Antibiotics have been shown to provide only minimal benefit, reducing the cough or illness by about half a day, and have adverse effects, including allergic reactions, nausea and vomiting, and Clostridium difficile infection. Evaluation and treatment of bronchitis include ruling out secondary causes for cough, such as pneumonia; educating patients about the natural course of the disease; and recommending symptomatic treatment and avoidance of unnecessary antibiotic use. Strategies to reduce inappropriate antibiotic use include delayed prescriptions, patient education, and calling the infection a chest cold.

  18. Design Recommendations for Concrete Tunnel Linings : Volume II. Summary of Research and Proposed Recommendations.

    Science.gov (United States)

    1983-11-01

    The report presents design recommendations for concrete tunnel linings for transportation tunnels. The recommendations developed as a result of in-depth analysis and model testing of the behavior of concrete tunnel linings. The research addressed pro...

  19. Rational Design of Tunnel Supports: Tunnel Support Loading Caused by Rock Failure

    Science.gov (United States)

    1975-05-01

    Minerale , Vol. 41; No. 1, Janvier, pp. 78-92, No. 4, Avril, pp. 313-315, 1959. Translation by C, Pairhurst, University of Nottingham Mining...G,: "Calcul du revetement des tunnels creuses dans des terrains presentant des deformations differees," Industrie Minerale , pp. 13-18

  20. Tunnelling anisotropic magnetoresistance due to antiferromagnetic CoO tunnel barriers

    NARCIS (Netherlands)

    Wang, Kai; Sanderink, Johannes G.M.; Bolhuis, Thijs; van der Wiel, Wilfred Gerard; de Jong, Machiel Pieter

    2015-01-01

    A new approach in spintronics is based on spin-polarized charge transport phenomena governed by antiferromagnetic (AFM) materials. Recent studies have demonstrated the feasibility of this approach for AFM metals and semiconductors. We report tunneling anisotropic magnetoresistance (TAMR) due to the

  1. Tunneling conductivity in composites of attractive colloids

    Science.gov (United States)

    Nigro, B.; Grimaldi, C.; Miller, M. A.; Ryser, P.; Schilling, T.

    2012-04-01

    In conductor-insulator nanocomposites in which conducting fillers are dispersed in an insulating matrix, the electrical connectedness is established by inter-particle tunneling or hopping processes. These systems are intrinsically non-percolative and a coherent description of the functional dependence of the conductivity σ on the filler properties, and in particular of the conductor-insulator transition, requires going beyond the usual continuum percolation approach by relaxing the constraint of a fixed connectivity distance. In this article, we consider dispersions of conducting spherical particles which are connected to all others by tunneling conductances and which are subjected to an effective attractive square-well potential. We show that the conductor-insulator transition at low contents ϕ of the conducting fillers does not determine the behavior of σ at larger concentrations, in striking contrast to what is predicted by percolation theory. In particular, we find that at low ϕ the conductivity is governed almost entirely by the stickiness of the attraction, while at larger ϕ values σ depends mainly on the depth of the potential well. As a consequence, by varying the range and depth of the potential while keeping the stickiness fixed, composites with similar conductor-insulator transitions may display conductivity variations of several orders of magnitude at intermediate and large ϕ values. By using a recently developed effective medium theory and the critical path approximation, we explain this behavior in terms of dominant tunneling processes which involve inter-particle distances spanning different regions of the square-well fluid structure as ϕ is varied. Our predictions could be tested in experiments by changing the potential profile with different depletants in polymer nanocomposites.

  2. Nano-ADEPT Aeroloads Wind Tunnel Test

    Science.gov (United States)

    Smith, Brandon; Yount, Bryan; Kruger, Carl; Brivkalns, Chad; Makino, Alberto; Cassell, Alan; Zarchi, Kerry; McDaniel, Ryan; Ross, James; Wercinski, Paul; hide

    2016-01-01

    A wind tunnel test of the Adaptable Deployable Entry and Placement Technology (ADEPT) was conducted in April 2015 at the US Army's 7 by10 Foot Wind Tunnel located at NASA Ames Research Center. Key geometric features of the fabric test article were a 0.7 meter deployed base diameter, a 70 degree half-angle forebody cone angle, eight ribs, and a nose-to-base radius ratio of 0.7. The primary objective of this wind tunnel test was to obtain static deflected shape and pressure distributions while varying pretension at dynamic pressures and angles of attack relevant to entry conditions at Earth, Mars, and Venus. Other objectives included obtaining aerodynamic force and moment data and determining the presence and magnitude of any dynamic aeroelastic behavior (buzz/flutter) in the fabric trailing edge. All instrumentation systems worked as planned and a rich data set was obtained. This paper describes the test articles, instrumentation systems, data products, and test results. Four notable conclusions are drawn. First, test data support adopting a pre-tension lower bound of 10 foot pounds per inch for Nano-ADEPT mission applications in order to minimize the impact of static deflection. Second, test results indicate that the fabric conditioning process needs to be reevaluated. Third, no flutter/buzz of the fabric was observed for any test condition and should also not occur at hypersonic speeds. Fourth, translating one of the gores caused ADEPT to generate lift without the need for a center of gravity offset. At hypersonic speeds, the lift generated by actuating ADEPT gores could be used for vehicle control.

  3. Myofascial release of carpal tunnel syndrome.

    Science.gov (United States)

    Sucher, B M

    1993-01-01

    Current treatment for carpal tunnel syndrome may be ineffective or associated with complications or recurrence. In the case reported here, a myofascial release by the physician combined with the patient's self-stretch reduced pain and numbness and improved electromyographic results. The manipulative approach releases the transverse carpal ligament,-and "opens" or dilates the canal. The patient stretches the wrist, digits, and thumb, including myofascial components. An aggressive, conservative approach lessens the need for surgery in mild to moderate cases. Studies with magnetic resonance imaging may be helpful to document canal size before and after treatment.

  4. Osteopathic manipulative medicine for carpal tunnel syndrome.

    Science.gov (United States)

    Siu, Gilbert; Jaffe, J Douglas; Rafique, Maryum; Weinik, Michael M

    2012-03-01

    Carpal tunnel syndrome (CTS) is 1 of the most common peripheral nerve entrapment disorders. Osteopathic manipulative medicine can be invaluable in diagnosing and managing CTS. Combined with a patient's history and a standard physical examination, an osteopathic structural examination can facilitate localizing the nerve entrapment, diagnosing CTS, and monitoring the disease process. Osteopathic manipulative treatment is noninvasive and can be used to supplement traditional CTS treatment methods. The authors also review the relevant anatomy involving CTS and the clinical efficacy of osteopathic manipulative medicine in the management of this disorder.

  5. Occupational health hazard: carpal tunnel syndrome.

    Science.gov (United States)

    Lewis, L C; Mireles, D Z

    1997-04-01

    A significant portion of the American population today is exposed to computer-related illnesses. One of the most common injuries is carpal tunnel syndrome (CTS). Perioperative nurses will become increasingly exposed to computer-related illnesses with the advent of computerized patient record systems. Economic loss, physical disability, and emotional distress are frequent outcomes of computer-related illnesses. Federal legislation addressing preventive measures is currently nonexistent. Clinicians, as both employers and consumers of computer technology, must address computer-related illnesses, such as CTS, through identification of related risk factors, early symptoms, implementation of ergonomic measures, and support of federal and industrial safety standards.

  6. Plan of SPS to LHC transfer tunnels

    CERN Multimedia

    Laurent Guiraud

    2001-01-01

    This diagram shows the LHC and the SPS pre-accelerator (in blue) and the transfer lines that will connect them (in red). Spanning the France-Swiss border (shown by green crosses), the 27-km LHC tunnel will receive a beam that has been pre-accelerated to 450 GeV in the smaller SPS storage ring. The transfer lines will remove each beam from the SPS and inject them into the LHC where they will be accelerated to the full energy of 7 TeV.

  7. Multiple Ligament Reconstruction Femoral Tunnels: Intertunnel Relationships and Guidelines to Avoid Convergence.

    Science.gov (United States)

    Moatshe, Gilbert; Brady, Alex W; Slette, Erik L; Chahla, Jorge; Turnbull, Travis Lee; Engebretsen, Lars; LaPrade, Robert F

    2017-03-01

    Knee dislocations often require multiple concurrent ligament reconstructions, which involve creating several tunnels in the distal femur. Therefore, the risk of tunnel convergence is increased because of the limited bone volume within the distal aspect of the femur. To assess the risk of tunnel convergence and determine the optimal reconstruction tunnel orientations for multiple ligament reconstructions in the femur. Descriptive laboratory study. Three-dimensional knee models were developed from computed tomography scans of 21 patients. Medical image processing software was used to create tunnels for each of the primary ligamentous structures, replicating a surgical approach that would be used in multiple ligament reconstructions. Thereafter, the tunnel orientation was varied in surgically relevant directions to determine orientations that minimized the risk of tunnel convergence. The orientation of the anterior cruciate ligament (ACL) and posterior cruciate ligament (PCL) tunnels was held constant throughout the study, while the orientation of the fibular collateral ligament (FCL), popliteus tendon (PLT), superficial medial collateral ligament (sMCL), and posterior oblique ligament (POL) tunnels was varied to avoid convergence. A high risk of tunnel convergence was observed between the FCL and ACL tunnels when the FCL tunnel was aimed at 0° in the axial and coronal planes. Aiming the FCL tunnel 35° anteriorly minimized convergence with the ACL tunnel. No tunnel convergence was observed for the PLT tunnel aimed 35° anteriorly and parallel to the FCL tunnel. To avoid convergence between the sMCL and PCL tunnels, the sMCL tunnels should be aimed 40° proximally in the coronal plane and 20° to 40° anteriorly. During concomitant POL reconstruction, the sMCL should be aimed 40° proximally and anteriorly and the POL 20° proximally and anteriorly. The PLT and POL tunnels aimed at 0° in both the coronal and axial planes had an increased risk of violating the

  8. High resolution sonography of the carpal tunnel syndrome; Ecografia con alta risoluzione nello studio della sindrome del tunnel carpale

    Energy Technology Data Exchange (ETDEWEB)

    Ferrari, Francesco Saverio; Guazzi, Gianni; Belcapo, Luigi; Stefani, Paolo [Siena, Univ. (Italy). Istituto di Scienze Eidologiche e Radiologiche; Della Sala, Luca; Cozza, Sabino [Ospedale di Volterra, Pisa (Italy). Servizio di Radiologia; Mariottini, Aldo; Bolognini, Andrea [Siena, Univ. (Italy). Istituto di Neurochirurgia

    1997-04-01

    They investigated the reliability of some US signs in the diagnosis of the carpal tunnel syndrome. They carried out a single-blind study with 13-MHz high resolution probes and electromyography on 132 patients with clinical evidence of the carpal tunnel syndrome; a control group of 20 asymptomatic patients was also submitted to US. Eighty-six of 107 patients with US signs of the carpal tunnel syndrome were then submitted to surgical decompression while the extant 21 patients underwent conservative treatment and clinical follow-up. To diagnose the carpal tunnel syndrome they considered the following US patterns: median nerve changes palmar bowing of the flexor retinaculum, thickening of the transverse carpal ligament and increased depth of the carpal tunnel, as measured from the apex of the transverse carpal ligament convexity to the underlying carpal bone. Median nerve changes were unreliable signs and were missing in many cases: only 45 of 107 patients exhibited median nerve swelling before and/or its flattening in the carpal tunnel (42 %). Such indirect signs as the thickening of the transverse carpal ligament in chronic cases were demonstrated in 94 of 107 patients with the carpal tunnel syndrome (88 %) and canal depending in all unilateral carpal tunnel syndromes was shown in 92 of 107 patients (87 %); both these signs proved to be much more reliable. The palmar bowling of the flexor retinaculum was also difficult to demonstrate in surgical patients or in those with connective tissue fibrosis within the tunnel: this sign was demonstrated in 80 of 107 patients with the carpal tunnel syndrome confirmed with electromyography (75 %). Tanzer and Rietze reported median nerve changes observed at surgery in 43 % and 66 % of their patients. Recent MR findings in asymptomatic wrists have demonstrated that the normal median nerve has an elliptical shape inside the carpal tunnel. (Abstract Truncated)

  9. Effect of Blast-Induced Vibration from New Railway Tunnel on Existing Adjacent Railway Tunnel in Xinjiang, China

    Science.gov (United States)

    Liang, Qingguo; Li, Jie; Li, Dewu; Ou, Erfeng

    2013-01-01

    The vibrations of existing service tunnels induced by blast-excavation of adjacent tunnels have attracted much attention from both academics and engineers during recent decades in China. The blasting vibration velocity (BVV) is the most widely used controlling index for in situ monitoring and safety assessment of existing lining structures. Although numerous in situ tests and simulations had been carried out to investigate blast-induced vibrations of existing tunnels due to excavation of new tunnels (mostly by bench excavation method), research on the overall dynamical response of existing service tunnels in terms of not only BVV but also stress/strain seemed limited for new tunnels excavated by the full-section blasting method. In this paper, the impacts of blast-induced vibrations from a new tunnel on an existing railway tunnel in Xinjiang, China were comprehensively investigated by using laboratory tests, in situ monitoring and numerical simulations. The measured data from laboratory tests and in situ monitoring were used to determine the parameters needed for numerical simulations, and were compared with the calculated results. Based on the results from in situ monitoring and numerical simulations, which were consistent with each other, the original blasting design and corresponding parameters were adjusted to reduce the maximum BVV, which proved to be effective and safe. The effect of both the static stress before blasting vibrations and the dynamic stress induced by blasting on the total stresses in the existing tunnel lining is also discussed. The methods and related results presented could be applied in projects with similar ground and distance between old and new tunnels if the new tunnel is to be excavated by the full-section blasting method.

  10. Behaviour of tunnelling transition rate of argon atom exposed to ...

    Indian Academy of Sciences (India)

    in the strong laser field ionization of atoms and molecules. Tunnel ionization takes place when the electric field changes the atomic potential and electron sees a very small mod- ified potential and can tunnel through it. Keldysh [4] made the first attempt to perform a general analysis of ionization of atoms by laser radiation as ...

  11. Quantum tunneling of Bose-Einstein condensates in optical lattices

    CERN Document Server

    Fan Wen Bin

    2003-01-01

    In quantum tunneling a particle with energy E can pass through a high potential barrier V(>E) due to the wave character of the particle. Bose-Einstein condensates can display very strong tunneling depending on the structure of the trap, which may be a double-well or optical lattices. The employed for the first time to our knowledge the periodic instanton method to investigate tunneling of Bose-Einstein condensates in optical lattices. The results show that there are two kinds of tunneling in this system, Landau-Zener tunneling between extended states of the system and Wannier-Stark tunneling between localized states of the system, and that the latter is 1000 times faster than the former. The also obtain the total decay rate for a wide range of temperature, including classical thermal activation, thermally assisted tunneling and quantum tunneling. The results agree with experimental data in references. Finally, the propose an experimental protocol to observe this new phenomenon in future experiments

  12. Understanding Soliton Spectral Tunneling as a Spectral Coupling Effect

    DEFF Research Database (Denmark)

    Guo, Hairun; Wang, Shaofei; Zeng, Xianglong

    2013-01-01

    between channels, here we suggest that the soliton spectral tunneling effect can be understood supported by a spectral phase coupler. The dispersive wave number in the spectral domain must have a coupler-like symmetric profile for soliton spectral tunneling to occur. We show that such a spectral coupler...

  13. Interleaving of beam lines inside the PS tunnel

    CERN Multimedia

    1983-01-01

    View against the direction of the proton beams. The PS ring (section 26) is on the left. The injection tunnel for LEAR leaving from here has increased the trafic in this already busy area where the two Linacs and the transfer tunnel leading to the SPS, ISR and AA join the PS ring (cf. photo 7802260, 7802261, Annual Report 1981, p. 89, fig. 12).

  14. Thermal Environment inside a Tunnel after Thermobaric Explosion

    Directory of Open Access Journals (Sweden)

    Fei Chen

    2017-01-01

    Full Text Available The outstanding thermal damage effect of thermobaric explosive (TBX is enhanced in closed or semiclosed spaces, which may pose a serious threat to the security of people sheltered in tunnels or other protective engineering. In order to investigate the thermal environment inside a tunnel after thermobaric explosion, we developed a damage evaluation method for the thermal radiation of explosion fireballs in tunnels; secondly, the air temperature distribution inside a tunnel shortly after explosion was theoretically analyzed; finally, the dynamic thermal environment after the explosion and the influences of TBXs mass and initial ground temperature on it in cases of open and blocked tunnels were numerically simulated with the FLUENT software. The results show that the fireball thermal radiation damage occurs mainly in the vicinity of the explosion source. The air temperature inside a tunnel shortly after the explosion decreases continuously with increasing distance from the explosion source and finally reaches the initial air temperature. The decay rate of air temperature inside a tunnel is slower in the blocked case, which increases the probability of causing a secondary fire disaster. The increase of explosive mass and the initial ground temperature favor the high-temperature performance of TBX, especially for the blocked tunnel.

  15. Expected and Actual Improvement of Symptoms With Carpal Tunnel Release

    NARCIS (Netherlands)

    Becker, Stéphanie J. E.; Makanji, Heeren S.; Ring, David

    2012-01-01

    Purpose This study tested the null hypothesis that there is no difference between expected improvement and actual improvement of symptoms with carpal tunnel release (CTR). Secondary analyses addressed factors associated with both expected relief and actual relief of symptoms with carpal tunnel

  16. Build an Inexpensive Wind Tunnel to Test CO2 Cars

    Science.gov (United States)

    McCormick, Kevin

    2012-01-01

    As part of the technology education curriculum, the author's eighth-grade students design, build, test, and race CO2 vehicles. To help them in refining their designs, they use a wind tunnel to test for aerodynamic drag. In this article, the author describes how to build a wind tunnel using inexpensive, readily available materials. (Contains 1…

  17. 'Bony' cubital tunnel syndrome caused by heterotopic ossification.

    Science.gov (United States)

    Wu, Yuxuan; Liu, Meng; Qu, Wei

    2017-10-11

    We reported a rare case of cubital tunnel syndrome caused by heterotopic ossification after burns. The ulnar nerve was encircled by bony tunnel structure which cause nerve compression, resulting in ulnar nerve lesion. Our case sheds light on possible etiological association which may help clinical management.

  18. Problems with tunneling of thin shells from black holes

    Indian Academy of Sciences (India)

    Specifically for shells tunneling out of black holes, this quantity is not invariant under canonical transformations. It can be interpreted as the transmission coefficient only in the cases in which it is invariant under canonical transformations. Although such cases include alpha decay, they do not include the tunneling of shells ...

  19. Tunneling Time in the Landau-Zener Model

    OpenAIRE

    Yan, Yue; Wu, Biao

    2008-01-01

    We give a general definition for the tunneling time in the Landau-Zener model. This definition allows us to compute numerically the Landau-Zener tunneling time at any sweeping rate without ambiguity. We have also obtained analytical results in both the adiabatic limit and the sudden limit. Whenever applicable, our results are compared to previous results and they are in good agreement.

  20. Contribution of mineral tunneling to total feldspar weathering

    NARCIS (Netherlands)

    Smits, M.M.; Hoffland, E.; Jongmans, A.G.; Breemen, van N.

    2005-01-01

    In this study, we quantified the contribution of mineral tunneling by fungi to weathering of feldspars and ecosystem influx of K and Ca. We studied the surface soils of 11 podzols across a Lake Michigan sand dune chronosequence with soil ages between 450 and 5000 years. Weathering by tunneling was