Dynamic enhanced MRI of the subacromial bursa: correlation with arthroscopic and histological findings

International Nuclear Information System (INIS)

Matsuzaki, S.; Yoneda, M.; Kobayashi, Y.; Fukushima, S.; Wakitani, S.

2003-01-01

Objective: To assess dynamic MRI with Gd-DTPA enhancement for evaluating inflammatory changes in the subacromial bursa. Design and patients: We detected the signal intensity changes in dynamic MRI of the subacromial bursa, and confirmed these macroscopically by arthroscopy and histologically. The signal intensity was measured using built-in software, and the enhancement ratio (E ratio) was calculated from dynamic MR images. In addition, as a parameter of the rate of the increase in the signal intensity from 0 to 80 s, the mean increase per second in the E ratio was obtained as the coefficient of enhancement (CE). The correlation was studied of the E ratio and CE with the arthroscopic findings (redness, villous formation, thickening and adhesion), and of the E ratio and CE with the histological findings (capillary proliferation, papillary hyperplasia, fibrosis and inflammatory cell infiltration) of the subacromial bursa. Of patients with shoulder pain, this study included those with rotator cuff injury; patients with rheumatoid arthritis or pitching shoulder disorders were excluded. There were 27 patients (15 men, 12 women) ranging in age from 25 to 73 years (mean 49.1 years). Dynamic MRI of the shoulder was also performed on the healthy side of 10 patients and in five normal young volunteers. Results and conclusions: Changes in signal intensity on dynamic MRI were measured in the subacromial bursa. The E ratio (80 s) and CE (0-80 s) were significantly correlated with redness and villous formation as arthroscopic findings, positively correlated with capillary proliferation and papillary hyperplasia as histological findings (p < 0.05), and negatively correlated with fibrosis as a histological finding (p < 0.05) in the subacromial bursa. The patterns of dynamic curves were well correlated with the bursoscopic and histological findings of the synovium of the subacromial bursa. Dynamic MRI appears to correlate with inflammatory activity of synovium of the subacromial

Physiotherapy improves patient reported shoulder function and health status in patients with subacromial impingement syndrome

DEFF Research Database (Denmark)

Storgaard, Filip Holst; Pedersen, Christina Gravgaard; Jensen, Majbritt Lykke

Physiotherapy improves patient reported shoulder function and health status in patients with subacromial impingement syndrome.......Physiotherapy improves patient reported shoulder function and health status in patients with subacromial impingement syndrome....

Preoperative conventional magnetic resonance images versus magnetic resonance arthrography of subacromial impingement syndrome

International Nuclear Information System (INIS)

Ahn, Sang Hyuk; Park, Jung Hwan; Moon, Tae Yong; Lee, In Sook; Lee, Seung Jun

2012-01-01

To evaluate the usefulness of conventional magnetic resonance images (MRI) for arthroscopic surgery in subacromial impingement syndrome of the shoulder, as an alternative to MR arthrography with additional T2 fat saturation images (MRA). The preoperative MRI of 77 patients (45 females, 32 males) (52 right, 25 left) and MRA of 34 patients (14 females, 20 males) (24 right, 10 left) with subsequent arthroscopic confirmation of subacromial impingement syndrome were reviewed retrospectively. The lesions requiring arthroscopic surgery were 95 subacromial spurs, 101 subacromial bursitis, and 51 full-thickness and 44 partial thickness tears of the supraspinatus among 111 cases for both studies. A two by two table was constructed in order to calculate the sensitivity and specificity of both studies against arthroscopic outcomes. Also we analyzed the false positive and false negative cases of the full-thickness tears individually. The detection rates of subacromial spur and bursitis and full and partial thickness tears of the supraspinatus were 91%, 94%, 77%, and 65% in MRI and 93%, 100%, 83%, and 77% in MRA respectively. Their specificities were 33%, 33%, 90%, and 76% in MRI and 50%, 75%, 100%, and 71% in MRA respectively. Eleven false negative cases in regards to MRI resulted in Ellman's grade 3 partial thickness tear (72.7%), mild bursitis (63.6%), greater tuberosity erosion (45.5%), and negative fluid signal of the glenohumeral joint (81.8%). Three false positive cases on the MRI were induced from errors with lower window depth and width on the imagings. Two false negative cases on MRA were induced from the adhesion between Ellman's grade 3 rim rent tear and the glenohumeral joint cavity. Conventional MR images could be used to decide the arthroscopic surgery in subacromial impingement syndrome, as an alternative to MR arthrography with additional T2 fat saturation images

Preoperative conventional magnetic resonance images versus magnetic resonance arthrography of subacromial impingement syndrome

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Ahn, Sang Hyuk; Park, Jung Hwan; Moon, Tae Yong [Pusan National Univ. Yangsan Hospital, Yangsan (Korea, Republic of); Lee, In Sook; Lee, Seung Jun [Pusan National Univ. Hospital, Busan (Korea, Republic of)

2012-09-15

To evaluate the usefulness of conventional magnetic resonance images (MRI) for arthroscopic surgery in subacromial impingement syndrome of the shoulder, as an alternative to MR arthrography with additional T2 fat saturation images (MRA). The preoperative MRI of 77 patients (45 females, 32 males) (52 right, 25 left) and MRA of 34 patients (14 females, 20 males) (24 right, 10 left) with subsequent arthroscopic confirmation of subacromial impingement syndrome were reviewed retrospectively. The lesions requiring arthroscopic surgery were 95 subacromial spurs, 101 subacromial bursitis, and 51 full-thickness and 44 partial thickness tears of the supraspinatus among 111 cases for both studies. A two by two table was constructed in order to calculate the sensitivity and specificity of both studies against arthroscopic outcomes. Also we analyzed the false positive and false negative cases of the full-thickness tears individually. The detection rates of subacromial spur and bursitis and full and partial thickness tears of the supraspinatus were 91%, 94%, 77%, and 65% in MRI and 93%, 100%, 83%, and 77% in MRA respectively. Their specificities were 33%, 33%, 90%, and 76% in MRI and 50%, 75%, 100%, and 71% in MRA respectively. Eleven false negative cases in regards to MRI resulted in Ellman's grade 3 partial thickness tear (72.7%), mild bursitis (63.6%), greater tuberosity erosion (45.5%), and negative fluid signal of the glenohumeral joint (81.8%). Three false positive cases on the MRI were induced from errors with lower window depth and width on the imagings. Two false negative cases on MRA were induced from the adhesion between Ellman's grade 3 rim rent tear and the glenohumeral joint cavity. Conventional MR images could be used to decide the arthroscopic surgery in subacromial impingement syndrome, as an alternative to MR arthrography with additional T2 fat saturation images.

The activity pattern of shoulder muscles in subjects with and without subacromial impingement

DEFF Research Database (Denmark)

Diederichsen, Louise Pyndt; Nørregaard, Jesper; Dyhre-Poulsen, Poul

2009-01-01

Altered shoulder muscle activity is frequently believed to be a pathogenetic factor of subacromial impingement (SI) and therapeutic interventions have been directed towards restoring normal motor patterns. Still, there is a lack of scientific evidence regarding the changes in muscle activity in p...... that the different motor patterns might be a pathogenetic factor of SI, perhaps due to inappropriate neuromuscular strategies affecting both shoulders....

MR imaging after therapeutic injection of the subacromial bursa

International Nuclear Information System (INIS)

Major, N.M.

1999-01-01

Objective. As a therapeutic injection into the subacromial bursa (SAB) is commonly performed for impingement syndrome, it is important to know whether this fluid can be retained for a period of time and cause confusion with a pathologic collection of fluid. This study identifies and describes the appearance of recent subacromial injection using MR imaging, and the appearance of a potential complication.Design and patients. Fourteen asymptomatic shoulders were studied with MR imaging using fast spin echo T2-weighted imaging (1.5 T) prior to injection with 7 cm 3 of xylocaine. Four shoulders had subacromial fluid and were eliminated from the study. The remaining 10 (9 men, 1 woman; age range 27-36 years, average age 33 years) were then re-imaged immediately, and at 6, 12 and 24 h after the injection or until fluid resolved. Each set of images was reviewed for the presence of fluid in the SAB and for additional abnormalities.Results. Fluid was identified in all subjects in the SAB in the immediate, 6 and 12 h post-injection images. At 24 h, fluid was not identified within the SAB in eight of 10 patients. In one patient fluid resolved in 48 h. The other continued to demonstrate fluid in the SAB and in the joint as well as abnormal signal in the infraspinatus muscle from a presumed myositis. Imaging was performed up to 10 days after the injection in this patient.Conclusions. It is known that fluid identified in the SAB without evidence of a cuff tear may be due to bursitis. However, if MR imaging is performed within 24 h of injection, the presence of the fluid may be iatrogenic. In addition, the history of recent therapeutic injection is very important as complications such as myositis can occur as a result of the injection. Knowledge of injection prior to imaging is vital for accurate interpretation of MR shoulder examinations. (orig.)

MR imaging after therapeutic injection of the subacromial bursa

Energy Technology Data Exchange (ETDEWEB)

Major, N.M. [Duke University Medical Center, Department of Radiology, Division Musculoskeletal, Durham, NC (United States)

1999-11-01

Objective. As a therapeutic injection into the subacromial bursa (SAB) is commonly performed for impingement syndrome, it is important to know whether this fluid can be retained for a period of time and cause confusion with a pathologic collection of fluid. This study identifies and describes the appearance of recent subacromial injection using MR imaging, and the appearance of a potential complication.Design and patients. Fourteen asymptomatic shoulders were studied with MR imaging using fast spin echo T2-weighted imaging (1.5 T) prior to injection with 7 cm{sup 3} of xylocaine. Four shoulders had subacromial fluid and were eliminated from the study. The remaining 10 (9 men, 1 woman; age range 27-36 years, average age 33 years) were then re-imaged immediately, and at 6, 12 and 24 h after the injection or until fluid resolved. Each set of images was reviewed for the presence of fluid in the SAB and for additional abnormalities.Results. Fluid was identified in all subjects in the SAB in the immediate, 6 and 12 h post-injection images. At 24 h, fluid was not identified within the SAB in eight of 10 patients. In one patient fluid resolved in 48 h. The other continued to demonstrate fluid in the SAB and in the joint as well as abnormal signal in the infraspinatus muscle from a presumed myositis. Imaging was performed up to 10 days after the injection in this patient.Conclusions. It is known that fluid identified in the SAB without evidence of a cuff tear may be due to bursitis. However, if MR imaging is performed within 24 h of injection, the presence of the fluid may be iatrogenic. In addition, the history of recent therapeutic injection is very important as complications such as myositis can occur as a result of the injection. Knowledge of injection prior to imaging is vital for accurate interpretation of MR shoulder examinations. (orig.)

Subdeltoid/subacromial bursitis associated with influenza vaccination.

Science.gov (United States)

Cook, Ian F

2014-01-01

A 76-year-old male presented with subacromial/subdeltoid bursitis following influenza vaccine administration into the left deltoid muscle. This shoulder injury related to vaccine administration (SIRVA) could have been prevented by the use of a safe, evidence based protocol for the intramuscular injection of the deltoid muscle.

Subacromial bursitis following human papilloma virus vaccine misinjection.

Science.gov (United States)

Uchida, Soshi; Sakai, Akinori; Nakamura, Toshitaka

2012-12-17

A patient presented at our clinic with severe subacromial bursitis, which persisted for several months following a third booster injection with Cervarix™. Chronic subacromial bursitis manifested itself in this patient after what appeared to be the misinjection of vaccine in close proximity to the acromion. This bursitis was resistant to conventional physiotherapy and to corticosteroid therapy, but was responsive to arthroscopic surgery. Since such patients may present to an arthroscopic surgeon only months after receiving a vaccine injection, this etiological link may not be fully appreciated by treating clinicians. Further, the accuracy of injection in the deltoid region also appears under appreciated, and this report highlights the importance of accurate injection to the deltoid region or in certain cases, the value of simply changing the injection site to another larger muscle. Copyright © 2012 Elsevier Ltd. All rights reserved.

Physiotherapy after subacromial decompression surgery

DEFF Research Database (Denmark)

Christiansen, David Høyrup; Falla, Deborah; Frost, Poul

2015-01-01

This paper describes the development and details of a standardised physiotherapy exercise intervention designed to address pain and disability in patients with difficulty returning to usual activities after arthroscopic decompression surgery for subacromial impingement syndrome. To develop...... the intervention, the literature was reviewed with respect to the effectiveness of postoperative exercises, components of previous exercise programmes were extracted, and input from clinical physiotherapists in the field was obtained through a series of workshops. The physiotherapy exercise intervention...

Guideline for diagnosis and treatment of subacromial pain syndrome: a multidisciplinary review by the Dutch Orthopaedic Association

NARCIS (Netherlands)

Diercks, R.; Bron, C.; Dorrestijn, O.; Meskers, C.; Naber, R.; Ruiter, T. de; Willems, J.; Winters, J.; Woude, H.J. van der; et al.,

2014-01-01

Treatment of "subacromial impingement syndrome" of the shoulder has changed drastically in the past decade. The anatomical explanation as "impingement" of the rotator cuff is not sufficient to cover the pathology. "Subacromial pain syndrome", SAPS, describes the condition better. A working group

Effect of glenohumeral elevation on subacromial supraspinatus compression risk during simulated reaching.

Science.gov (United States)

Lawrence, Rebekah L; Schlangen, Dustin M; Schneider, Katelyn A; Schoenecker, Jonathan; Senger, Andrea L; Starr, William C; Staker, Justin L; Ellermann, Jutta M; Braman, Jonathan P; Ludewig, Paula M

2017-10-01

Mechanical subacromial rotator cuff compression is one theoretical mechanism in the pathogenesis of rotator cuff disease. However, the relationship between shoulder kinematics and mechanical subacromial rotator cuff compression across the range of humeral elevation motion is not well understood. The purpose of this study was to investigate the effect of humeral elevation on subacromial compression risk of the supraspinatus during a simulated functional reaching task. Three-dimensional anatomical models were reconstructed from shoulder magnetic resonance images acquired from 20 subjects (10 asymptomatic, 10 symptomatic). Standardized glenohumeral kinematics from a simulated reaching task were imposed on the anatomic models and analyzed at 0, 30, 60, and 90° humerothoracic elevation. Five magnitudes of humeral retroversion were also imposed on the models at each angle of humerothoracic elevation to investigate the impact of retroversion on subacromial proximities. The minimum distance between the coracoacromial arch and supraspinatus tendon and footprint were quantified. When contact occurred, the magnitude of the intersecting volume between the supraspinatus tendon and coracoacromial arch was also quantified. The smallest minimum distance from the coracoacromial arch to the supraspinatus footprint occurred between 30 and 90°, while the smallest minimum distance to the supraspinatus tendon occurred between 0 and 60°. The magnitude of humeral retroversion did not significantly affect minimum distance to the supraspinatus tendon except at 60 or 90° humerothoracic elevation. The results of this study provide support for mechanical rotator cuff compression as a potential mechanism for the development of rotator cuff disease. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:2329-2337, 2017. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

The effect of scapular position on subacromial contact behavior: a cadaver study.

Science.gov (United States)

Muraki, Takayuki; Yamamoto, Nobuyuki; Sperling, John W; Steinmann, Scott P; Cofield, Robert H; An, Kai-Nan

2017-05-01

Patients with subacromial impingement were reported to show abnormal scapular positions during shoulder elevation. However, the relationship between the scapular positions and subacromial impingement is unclear. The purpose of this study was to biomechanically determine the effect of scapular position on subacromial contact behavior by using fresh frozen cadavers. The peak contact pressure on the coracoacromial arch was measured with a flexible tactile force sensor in 9 fresh frozen cadaver shoulders. The measurement was performed during passive glenohumeral elevation in the scapular plane ranging from 30° to 75°. The scapular downward and internal rotations and anterior tilt were simulated by tilting the scapula in 5° increments up to 20°. The measurement was also performed with combination of scapular downward and internal rotations and anterior tilt positions. The peak contact pressure decreased linearly with anterior tilt, and a significant difference between neutral scapular position (1.06 ± 0.89 MPa) and anterior tilt by 20° (0.46 ± 0.18 MPa) was observed (P < .05). However, the scapular positioning in the other directions did not change the peak contact pressure significantly. Furthermore, any combination of abnormal scapular positions did not affect peak contact pressure significantly. Scapular anterior tilt decreased peak contact pressure during passive shoulder elevation. In addition, scapular downward and internal rotations had little effect on peak contact pressure. The abnormal scapular motion reported in previous studies might not be directly related to symptoms caused by subacromial impingement. Copyright © 2017 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.

Subacromial bursitis with giant rice bodies as initial presentation of rheumatoid arthritis.

Science.gov (United States)

Subramaniam, Ramesh; Tan, Justina Wei Lyn; Chau, Cora Yuk Ping; Lee, Keng Thiam

2012-10-01

Rice body formation is a nonspecific response to chronic synovial inflammation associated with tuberculous arthritis, rheumatoid arthritis, juvenile rheumatoid arthritis, seronegative inflammatory arthritis, and even osteoarthritis. Such bodies were termed rice bodies because of their close resemblance to grains of polished white rice. We present a case report of a middle-aged woman with right shoulder subacromial/subdeltoid bursitis with giant rice body formation as her initial presentation of rheumatoid arthritis. Her right shoulder symptoms resolved after subacromial and subdeltoid bursectomy and removal of the rice bodies. She subsequently developed inflammatory arthritis of other joints, met the criteria for rheumatoid arthritis, and has been treated medically.

Subacromial impingement in patients with whiplash injury to the cervical spine

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Giddins Grey E

2008-06-01

Full Text Available Abstract Background Impingement syndrome and shoulder pain have been reported to occur in a proportion of patients following whiplash injuries to the neck. In this study we aim to examine these findings to establish the association between subacromial impingement and whiplash injuries to the cervical spine. Methods and results We examined 220 patients who had presented to the senior author for a medico-legal report following a whiplash injury to the neck. All patients were assessed for clinical evidence of subacromial impingement. 56/220 patients (26% had developed shoulder pain following the injury; of these, 11/220 (5% had clinical evidence of impingement syndrome. Only 3/11 patients (27% had the diagnosis made prior to evaluation for their medico-legal report. In the majority, other clinicians had overlooked the diagnosis. The seatbelt shoulder was involved in 83% of cases (p Conclusion After a neck injury a significant proportion of patients present with shoulder pain, some of whom have treatable shoulder pathology such as impingement syndrome. The diagnosis is, however, frequently overlooked and shoulder pain is attributed to pain radiating from the neck resulting in long delays before treatment. It is important that this is appreciated and patients are specifically examined for signs of subacromial impingement after whiplash injuries to the neck. Direct seatbelt trauma to the shoulder is one possible explanation for its aetiology.

Intra-rater and inter-rater reliability of the standardized ultrasound protocol for assessing subacromial structures

DEFF Research Database (Denmark)

Hougs Kjær, Birgitte; Ellegaard, Karen; Wieland, Ina

2017-01-01

BACKGROUND: US-examinations related to shoulder impingement (SI) often vary due to methodological differences, examiner positions, transducers, and recording parameters. Reliable US protocols for examination of different structures related to shoulder impingement are therefore needed. OBJECTIVES...... of the supraspinatus tendon (SUPRA) and subacromial subdeltoid (SASD) bursa in two imaging positions, and the acromial humeral distance (AHD) in one position. Additionally, agreement on dynamic impingement (DI) examination was performed. The intra- and inter-rater reliability was carried out on the same day...

Subacromial bursitis with rice bodies. Finding in magnetic resonance

International Nuclear Information System (INIS)

Miguel Campos, E. de; Hernandez Moreno, L.; Lafuente Martinez, J.; Godoy Lopez, M.A.; Ruiz Noguero, P.

1994-01-01

We present a case of subacromial bursitis associated with intraarticular loose bodies, constituted by accumulations of fibrin referred to as rice bodies, in a woman with seronegative rheumatoid arthritis. We demonstrate the clinical and imaging features of this disorder, especially stressing the magnetic resonance (MR) findings. The literature is reviewed. (Author) 14 refs

Arthroscopic Resection of The Distal Clavicle With Concomitant Subacromial Decompression: A Case Series

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HZ Chan

2014-07-01

Full Text Available Shoulder impingement syndrome and acromioclavicular joint osteoarthritis often occur simultaneously and easily missed. Kay et al. reported excellent results with combined arthroscopic subacromial decompression and resection of the distal end of the clavicle in patients with both disorders. Arthroscopic treatment of these disorders produces more favourable results than open procedures. We report two patients who were not responding to conservative management and were treated with direct arthroscopic distal clavicle excision and subacromial decompression in single setting. Both patients gained good postoperative outcome in terms of pain score, function and strength improvement assessed objectively with visual analogue score (VAS and University of California Los Angeles Score (UCLA.

Force steadiness, muscle activity, and maximal muscle strength in subjects with subacromial impingement syndrome

DEFF Research Database (Denmark)

Bandholm, Thomas; Rasmussen, Lars; Aagaard, Per

2006-01-01

physically active in spite of shoulder pain and nine healthy matched controls were examined to determine isometric and isokinetic submaximal shoulder-abduction force steadiness at target forces corresponding to 20%, 27.5%, and 35% of the maximal shoulder abductor torque, and maximal shoulder muscle strength......We investigated the effects of the subacromial impingement syndrome (SIS) on shoulder sensory-motor control and maximal shoulder muscle strength. It was hypothesized that both would be impaired due to chronic shoulder pain associated with the syndrome. Nine subjects with unilateral SIS who remained...

Specific or general exercise strategy for subacromial impingement syndrome-does it matter?

DEFF Research Database (Denmark)

Shire, Alison R; Stæhr, Thor A B; Overby, Jesper B

2017-01-01

Background Exercise is frequently suggested as a treatment option for patients presenting with symptoms of subacromial impingement syndrome. Some would argue implementing a specific exercise strategy with special focus on correction of kinematic deficits would be superior to general exercise stra...

Postoperative fentanyl patch versus subacromial bupivacaine infusion in arthroscopic shoulder surgery.

Science.gov (United States)

Merivirta, Riika; Äärimaa, Ville; Aantaa, Riku; Koivisto, Mari; Leino, Kari; Liukas, Antti; Kuusniemi, Kristiina

2013-07-01

The purpose of our study was to compare the effectiveness of subacromial bupivacaine infusion and a transdermal fentanyl patch in the treatment of postoperative pain after arthroscopic shoulder surgery. Sixty patients with rotator cuff disease scheduled for elective arthroscopic shoulder surgery were enrolled in the study. For the treatment of postoperative pain, 30 patients constituted group F and received a 12.0-μg/h fentanyl patch for 72 hours and saline solution infusion in a subacromial manner at the rate of 4 mL/h. The remaining 30 patients constituted group B and received a placebo patch and an infusion of 2.5-mg/mL bupivacaine in a subacromial manner for 72 hours. The primary outcome measure was the postoperative numerical rating scale pain score. The consumption of opioids, ibuprofen, and acetaminophen was also recorded. The Constant scores and general recovery were followed up until the 90th postoperative day. There was no statistically significant difference in the numerical rating scale scores (P = .60) between the groups. No differences in the use of rescue analgesic were observed except that the patients receiving bupivacaine used more ibuprofen (median, 1,200 mg v 600 mg) during the day of surgery (P = .042). No difference was found in general recovery between the groups. A fentanyl patch delivering 12-μg/h fentanyl offers an easy and safe treatment option as a part of multimodal analgesia with few adverse effects in the treatment of postoperative pain in a carefully selected patient group after arthroscopic shoulder surgery. Level I, randomized controlled trial. Copyright © 2013 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.

Exercise therapy after ultrasound-guided corticosteroid injections in patients with subacromial pain syndrome

DEFF Research Database (Denmark)

Ellegaard, Karen; Christensen, Robin; Rosager, Sara

2016-01-01

BACKGROUND: Subacromial pain syndrome (SAPS) accounts for around 50 % of all cases of shoulder pain. The most commonly used treatments are glucocorticosteroid (steroid) injections and exercise therapy; however, despite treatment SAPS patients often experience relapse of their symptoms. Therefore...... the clinical effect of combining steroid and exercise therapy is highly relevant to clarify. The aim of this randomized controlled trial was to investigate if exercise therapy added to steroid injection in patients with SAPS will improve the effect of the injection therapy on shoulder pain. METHODS......: In this two-arm randomized trial running over 26 weeks, patients with unilateral shoulder pain (> 4 weeks) and thickened subacromial bursa (> 2 mm on US) were included. At baseline all participants received two steroid injections into the painful shoulder with an interval of one week. Subsequently they were...

Synovial Chondromatosis of the Subacromial Bursa Causing a Bursal-Sided Rotator Cuff Tear

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Julie A. Neumann

2015-01-01

Full Text Available Synovial chondromatosis is an uncommon condition, and involvement of the shoulder is even more rare. We report on a 39-year-old female who presented with symptoms, radiographic features, and intraoperative findings consistent with multiple subacromial loose bodies resulting in a partial-thickness, bursal-sided rotator cuff tear of the supraspinatus muscle. She was treated with an arthroscopic removal of loose bodies, complete excision of the subacromial/subdeltoid bursa, acromioplasty, and rotator cuff repair. To our knowledge, this is the first report of arthroscopic treatment for a bursal-sided, partial-thickness rotator cuff tear treated with greater than two-year clinical and radiographic follow-up. We utilized shoulder scores, preoperative and postoperative range of motion, and imaging to assess the results of treatment and surveillance for recurrence in our patient after two-year follow-up.

Bilateral subacromial bursitis with macroscopic rice bodies: Ultrasound, CT and MR appearance

International Nuclear Information System (INIS)

Law, T.C.; Chong, S.F.; Lu, P.P.; Mak, K.H.

1998-01-01

The radiological findings of ultrasound, CT and MR of a case of bilateral subacromial bursitis with macroscopic rice bodies is described. MRI is the investigation of choice and the intravenous gadolinium-enhanced usefulness was noted. The previous literature is also reviewed. Copyright (1998) Blackwell Science Pty Ltd

Cost-effectiveness of exercise therapy after corticosteroid injection for moderate to severe shoulder pain due to subacromial impingement syndrome: a trial-based analysis.

Science.gov (United States)

Jowett, Sue; Crawshaw, Dickon P; Helliwell, Philip S; Hensor, Elizabeth M A; Hay, Elaine M; Conaghan, Philip G

2013-08-01

To perform a cost-effectiveness analysis of subacromial corticosteroid injection combined with exercise compared with exercise alone in patients with moderate to severe shoulder pain from subacromial impingement syndrome. A within-trial cost-effectiveness analysis with 232 patients randomized to physiotherapy-led injection combined with exercise (n = 115) or exercise alone (n = 117). The analysis was from a health care perspective with 24-week follow-up. Resource use information was collected from all patients on interventions, medication, primary and secondary care contacts, private health care use and over-the-counter purchases. The measure of outcome was quality-adjusted life years (QALYs), calculated from EQ-5D responses at baseline and three further time points. An incremental cost-effectiveness analysis was conducted. Mean per patient NHS costs (£255 vs £297) and overall health care costs (£261 vs £318) were lower in the injection plus exercise arm, but this difference was not statistically significant. Total QALYs gained were very similar in the two trial arms (0.3514 vs 0.3494 QALYs), although slightly higher in the injection plus exercise arm, indicating that injection plus exercise may be the dominant treatment option. At a willingness to pay of £20,000 per additional QALY gained, there was a 61% probability that injection plus exercise was the most cost-effective option. Injection plus exercise delivered by therapists may be a cost-effective use of resources compared with exercise alone and lead to lower health care costs and less time off work. International Standard Randomised Controlled Trial Number Register, http://www.controlled-trials.com/isrctn/, ISRCT 25817033.

Bilateral subacromial bursitis with macroscopic rice bodies: Ultrasound, CT and MR appearance

Energy Technology Data Exchange (ETDEWEB)

Law, T.C.; Chong, S.F.; Lu, P.P. [Kwong Wah Hospital (Hong Kong). Department of Radiology; Mak, K.H. [Kwong Wah Hospital (Hong Kong). Department of Orthopaedics and Traumatology

1998-05-01

The radiological findings of ultrasound, CT and MR of a case of bilateral subacromial bursitis with macroscopic rice bodies is described. MRI is the investigation of choice and the intravenous gadolinium-enhanced usefulness was noted. The previous literature is also reviewed. Copyright (1998) Blackwell Science Pty Ltd 5 refs., 1 tab., 4 figs.

MR imaging after rotator cuff repair: full-thickness defects and bursitis-like subacromial abnormalities in asymptomatic subjects

International Nuclear Information System (INIS)

Zanetti, M.; Hodler, J.; Jost, B.; Gerber, C.

2000-01-01

Objective. To determine the prevalence and extent of residual defects or retears and bursitis-like subacromial abnormalities on MR images after rotator cuff repair in asymptomatic subjects, and to define the clinical relevance of these findings.Design and patients. Fourteen completely asymptomatic patients and 32 patients with residual symptoms were investigated 27-53 months (mean 39 months) after open transosseous reinsertion of the rotator cuff. Coronal T2-weighted turbo spin-echo and turbo STIR or T2-weighted fat-suppressed MR images were obtained. The prevalence and extent of residual defects or retears of the rotator cuff and bursitis-like subacromial abnormalities were determined.Results. Residual defects or retears were detected in three (21%) and bursitis-like abnormalities in 14 (100%) of the 14 asymptomatic patients. Fifteen (47%) residual defects or retears and 31 (97%) bursitis-like abnormalities were diagnosed in the 32 patients with residual symptoms. The size of the residual defects/retears was significantly smaller in the asymptomatic group (mean 8 mm, range 6-11 mm) than in the symptomatic group (mean 32 mm, range 7-50 mm) (t-test, P=0.001). The extent of the bursitis-like subacromial abnormalities did not significantly differ (t-test, P>0.05) between asymptomatic (mean 28 x 3 mm) and symptomatic patients (mean 32 x 3 mm).Conclusion. Small residual defects or retears (<1 cm) of the rotator cuff are not necessarily associated with clinical symptoms. Subacromial bursitis-like MR abnormalities are almost always seen after rotator cuff repair even in patients without residual complaints. They may persist for several years after rotator cuff repair and appear to be clinically irrelevant. (orig.)

MR imaging after rotator cuff repair: full-thickness defects and bursitis-like subacromial abnormalities in asymptomatic subjects

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Zanetti, M.; Hodler, J. [Dept. of Radiology, University Hospital Balgrist, Zurich (Switzerland); Jost, B.; Gerber, C. [Dept. of Orthopedic Surgery, University Hospital Balgrist, Zurich (Switzerland)

2000-06-01

Objective. To determine the prevalence and extent of residual defects or retears and bursitis-like subacromial abnormalities on MR images after rotator cuff repair in asymptomatic subjects, and to define the clinical relevance of these findings.Design and patients. Fourteen completely asymptomatic patients and 32 patients with residual symptoms were investigated 27-53 months (mean 39 months) after open transosseous reinsertion of the rotator cuff. Coronal T2-weighted turbo spin-echo and turbo STIR or T2-weighted fat-suppressed MR images were obtained. The prevalence and extent of residual defects or retears of the rotator cuff and bursitis-like subacromial abnormalities were determined.Results. Residual defects or retears were detected in three (21%) and bursitis-like abnormalities in 14 (100%) of the 14 asymptomatic patients. Fifteen (47%) residual defects or retears and 31 (97%) bursitis-like abnormalities were diagnosed in the 32 patients with residual symptoms. The size of the residual defects/retears was significantly smaller in the asymptomatic group (mean 8 mm, range 6-11 mm) than in the symptomatic group (mean 32 mm, range 7-50 mm) (t-test, P=0.001). The extent of the bursitis-like subacromial abnormalities did not significantly differ (t-test, P>0.05) between asymptomatic (mean 28 x 3 mm) and symptomatic patients (mean 32 x 3 mm).Conclusion. Small residual defects or retears (<1 cm) of the rotator cuff are not necessarily associated with clinical symptoms. Subacromial bursitis-like MR abnormalities are almost always seen after rotator cuff repair even in patients without residual complaints. They may persist for several years after rotator cuff repair and appear to be clinically irrelevant. (orig.)

Diagnostic Accuracy of Clinical Examination and Imaging Findings for Identifying Subacromial Pain.

Science.gov (United States)

Cadogan, Angela; McNair, Peter J; Laslett, Mark; Hing, Wayne A

2016-01-01

The diagnosis of subacromial pathology is limited by the poor accuracy of clinical tests for specific pathologies. The aim of this study was to estimate the diagnostic accuracy of clinical examination and imaging features for identifying subacromial pain (SAP) defined by a positive response to diagnostic injection, and to evaluate the influence of imaging findings on the clinical diagnosis of SAP. In a prospective, diagnostic accuracy design, 208 consecutive patients presenting to their primary healthcare practitioner for the first time with a new episode of shoulder pain were recruited. All participants underwent a standardized clinical examination, shoulder x-ray series and diagnostic ultrasound scan. Results were compared with the response to a diagnostic block of xylocaineTM injected into the SAB under ultrasound guidance using ≥80% post-injection reduction in pain intensity as the positive anaesthetic response (PAR) criterion. Diagnostic accuracy statistics were calculated for combinations of clinical and imaging variables demonstrating the highest likelihood of a PAR. A PAR was reported by 34% of participants. In participants with no loss of passive external rotation, combinations of three clinical variables (anterior shoulder pain, strain injury, absence of symptoms at end-range external rotation (in abduction)) demonstrated 100% specificity for a PAR when all three were positive (LR+ infinity; 95%CI 2.9, infinity). A full-thickness supraspinatus tear on ultrasound increased the likelihood of a PAR irrespective of age (specificity 98% (95%CI 94, 100); LR+ 6.2; 95% CI 1.5, 25.7)). Imaging did not improve the ability to rule-out a PAR. Combinations of clinical examination findings and a full-thickness supraspinatus tear on ultrasound scan can help confirm, but not exclude, the presence of subacromial pain. Other imaging findings were of limited value for diagnosing SAP.

Exogenous application of platelet-leukocyte gel during open subacromial decompression contributes to improved patient outcome

NARCIS (Netherlands)

Everts, P. A.; Devilee, R. J. J.; Mahoney, C. Brown; van Erp, A.; Oosterbos, C. J. M.; Stellenboom, M.; Knape, J. T. A.; van Zundert, A.

2008-01-01

Background: Platelet-leukocyte gel (PLG) is being used during various surgical procedures in an attempt to enhance the healing process. We studied the effects of PLG on postoperative recovery of patients undergoing open subacromial decompression (OSD). Methods: PLG was produced from

Exercises may be as efficient as subacromial decompression in patients with subacromial stage II impingement: 4-8-years' follow-up in a prospective, randomized study

DEFF Research Database (Denmark)

Haahr, J. P.; Andersen, JH

2006-01-01

with graded physiotherapy and exercises or arthroscopic subacromial decompression. Outcomes were proportion of time per year with income transfers (indexed 0-1), including total transfers (marginalization), sick leave and disability pension obtained from the registry at the Ministry of Work. Self......-reported function, working capability, employment status and global improvement were obtained by questionnaire in September 2004. The main outcomes are given as differences in development from baseline. RESULTS: Seventy-nine (88%) responded to the questionnaire and registry data were obtained from 81. After 1 year...

Effectiveness of Kinesiotaping and Subacromial Corticosteroid Injection in Shoulder Impingement Syndrome.

Science.gov (United States)

Şahin Onat, Şule; Biçer, Seda; Şahin, Zehra; Küçükali Türkyilmaz, Ayşegül; Kara, Murat; Özbudak Demir, Sibel

2016-08-01

The aim of this study was to investigate whether kinesiotaping or subacromial corticosteroid injection provides additional benefit when used with nonsteroidal anti-inflammatory drugs (NSAIDs) in patients with shoulder impingement syndrome. Patients with shoulder impingement syndrome were divided into 3 groups as follows: NSAID group (n = 33), kinesiotaping group (kinesiotaping + NSAID) (n = 33), and injection group (subacromial corticosteroid injection + NSAID) (n = 33). Outcome measures including visual analog scale, shoulder ranges of motion, Shoulder Disability Questionnaire, and University of California-Los Angeles (UCLA) scale were evaluated before and after the treatment (fourth week). A total of 99 patients (21 male and 78 female patients) were enrolled in this study. Demographic and baseline clinical characteristics of the groups (except for body mass index and visual analog scale at night, both P = 0.05) were similar between the groups (all P > 0.05). Clinical parameters were found to have improved in the 3 groups (all P kinesiotaping and injection groups showed similar improvements (all P > 0.05), each group had better outcome than did the NSAID group as regards pain (activity visual analog scale), ranges of motion, and Shoulder Disability Questionnaire and UCLA scale scores (all P kinesiotaping or subacromial corticosteroid injection to NSAID treatment seems to have better/similar effectiveness in patients with shoulder impingement syndrome. Therefore, kinesiotaping might serve as an alternative treatment in case (injection of) corticosteroids are contraindicated. Complete the self-assessment activity and evaluation online at http://www.physiatry.org/JournalCME CME OBJECTIVES:: Upon completion of this article, the reader should be able to: (1) Delineate appropriate treatment options for shoulder impingement syndrome; (2) Identify treatment benefits of kinesiotaping and corticosteroid injections in shoulder impingement syndrome; and (3) Incorporate

Effectiveness of individualized physiotherapy on pain and functioning compared to a standard exercise protocol in patients presenting with clinical signs of subacromial impingement syndrome. A randomized controlled trial

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de Bie Rob A

2010-06-01

Full Text Available Abstract Background Shoulder impingement syndrome is a common musculoskeletal complaint leading to significant reduction of health and disability. Physiotherapy is often the first choice of treatment although its effectiveness is still under debate. Systematic reviews in this field highlight the need for more high quality trials to investigate the effectiveness of physiotherapy interventions in patients with subacromial impingement syndrome. Methods/Design This randomized controlled trial will investigate the effectiveness of individualized physiotherapy in patients presenting with clinical signs and symptoms of subacromial impingement, involving 90 participants aged 18-75. Participants are recruited from outpatient physiotherapy clinics, general practitioners, and orthopaedic surgeons in Germany. Eligible participants will be randomly allocated to either individualized physiotherapy or to a standard exercise protocol using central randomization. The control group will perform the standard exercise protocol aiming to restore muscular deficits in strength, mobility, and coordination of the rotator cuff and the shoulder girdle muscles to unload the subacromial space during active movements. Participants of the intervention group will perform the standard exercise protocol as a home program, and will additionally be treated with individualized physiotherapy based on clinical examination results, and guided by a decision tree. After the intervention phase both groups will continue their home program for another 7 weeks. Outcome will be measured at 5 weeks and at 3 and 12 months after inclusion using the shoulder pain and disability index and patients' global impression of change, the generic patient-specific scale, the average weekly pain score, and patient satisfaction with treatment. Additionally, the fear avoidance beliefs questionnaire, the pain catastrophizing scale, and patients' expectancies of treatment effect are assessed. Participants

Risk of surgery for subacromial impingement syndrome in relation to neck-shoulder complaints and occupational biomechanical exposures

DEFF Research Database (Denmark)

Svendsen, Susanne Wulff; Dalbøge, Annett; Andersen, JH

2013-01-01

OBJECTIVES: The aim of this longitudinal study was to evaluate the risk of surgery for subacromial impingement syndrome (SIS) in relation to neck-shoulder complaints and occupational biomechanical shoulder exposures. METHODS: The study was based on the Musculoskeletal Research Database at the Dan......OBJECTIVES: The aim of this longitudinal study was to evaluate the risk of surgery for subacromial impingement syndrome (SIS) in relation to neck-shoulder complaints and occupational biomechanical shoulder exposures. METHODS: The study was based on the Musculoskeletal Research Database....... Using no neck-shoulder complaints and low shoulder load at baseline as a reference, no neck-shoulder complaints and high shoulder load showed an adjusted hazard ratio (HR adj) of 2.55 [95% confidence interval (95% CI) 1.59-4.09], while neck-shoulder complaints in combination with high shoulder load...

Accuracy of diagnostic ultrasound in patients with suspected subacromial disorders: a systematic review and meta-analysis.

NARCIS (Netherlands)

Ottenheijm, R.P.; Jansen, M.J.; Staal, J.B.; Bruel, A. van den; Weijers, R.E.; Bie, R.A. de; Dinant, G.J.

2010-01-01

OBJECTIVE: To determine the diagnostic accuracy of ultrasound for detecting subacromial disorders in patients presenting in primary and secondary care settings. DATA SOURCES: Medline and Embase were searched on June 9, 2010. In addition, the reference list of 1 systematic review and all included

Distinguishing multiple rice body formation in chronic subacromial-subdeltoid bursitis from synovial chondromatosis

International Nuclear Information System (INIS)

Chen, Albert; Wong, Lun-Yick; Sheu, Chin-Yin; Chen, Be-Fong

2002-01-01

Multiple rice body formation is a complication of chronic bursitis. Although it resembles synovial chondromatosis clinically and on imaging, the literature suggests that analysis of radiographic and MR appearances should allow discrimination. We report the imaging findings in a 41-year-old man presenting with rice body formation in chronic subacromial-subdeltoid bursitis. We found that the signal intensity of the rice bodies is helpful in making the diagnosis. (orig.)

Distinguishing multiple rice body formation in chronic subacromial-subdeltoid bursitis from synovial chondromatosis

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Chen, Albert; Wong, Lun-Yick; Sheu, Chin-Yin [Department of Radiology, Mackay Memorial Hospital, Taipei (Taiwan); Chen, Be-Fong [Department of Pathology, Mackay Memorial Hospital, Taipei (Taiwan)

2002-02-01

Multiple rice body formation is a complication of chronic bursitis. Although it resembles synovial chondromatosis clinically and on imaging, the literature suggests that analysis of radiographic and MR appearances should allow discrimination. We report the imaging findings in a 41-year-old man presenting with rice body formation in chronic subacromial-subdeltoid bursitis. We found that the signal intensity of the rice bodies is helpful in making the diagnosis. (orig.)

Blood Glucose Levels in Diabetic Patients Following Corticosteroid Injections into the Subacromial Space of the Shoulder.

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Aleem, Alexander W; Syed, Usman Ali M; Nicholson, Thema; Getz, Charles L; Namdari, Surena; Beredjiklian, Pedro K; Abboud, Joseph A

2017-09-01

Corticosteroid injections are used to treat a variety of orthopedic conditions with the goal of decreasing pain and inflammation. Administration of systemic or local corticosteroids risks temporarily increasing blood glucose levels, especially diabetic patients. The purpose of this study is to quantify the effects of corticosteroid injections on blood glucose levels in diabetic patients with shoulder pathology. Diabetic patients who regularly monitored their blood glucose levels and were indicated for a subacromial corticosteroid injection were included in this prospective investigation. The typical normal morning fasting glucose and most recent hemoglobin A1c level was recorded for each patient. After injection, patients were contacted daily to confirm their fasting morning glucose level for 10 days post-injection. Seventeen consecutive patients were enrolled. Patients with hemoglobin A1c of patients' glucose levels returned to near baseline levels around post-injection day 8, while poorly controlled patients levels remained elevated. Similarly, insulin-dependent diabetic patients had an average increase in fasting glucose level of 99 mg/dL versus 50 mg/dL in non-insulin-dependent diabetic patients ( P patients with well-controlled diabetes experience smaller elevations and faster return to baseline glucose levels than patients with poor control. Insulin dependent diabetics experienced similar findings as patients with poor control. Future studies are needed to evaluate dosing to optimize the risks of blood glucose elevation while maintaining therapeutic benefit.

Ultrasound-guided subacromial injections of sodium hyaluronate for the management of rotator cuff tendinopathy: a prospective comparative study with rehabilitation therapy.

Science.gov (United States)

Merolla, G; Bianchi, P; Porcellini, G

2013-06-01

Rotator cuff (RC) tendinopathy is a common cause of pain and shoulder dysfunction. The literature evidence suggests that a combination of overuse and extrinsic compression may induce chronic RC tendinopathy. Aim of the current study was to compare the results of subacromial sodium hyaluronate injections with rehabilitation therapy. We enrolled 48 patients (M/F: 26/22; mean age: 50 years; shoulder right/left: 29/19) with persistent shoulder pain for at least 4 months. Exclusion criteria were as follows: RC tear, calcifying tendinitis, glenohumeral instability, osteoarthritis, rheumatic diseases, physical therapy and/or injection in the previous 4 months, shoulder surgery, anesthetic nerve block, trauma, and severe medical diseases. The included subjects received either two ultrasound-guided subacromial hyaluronic acid (HA) injections (25 patients, HA group) at baseline and 14 days, or underwent rehabilitation therapy (23 patients, Physio group) including active shoulder mobilization, soft tissue stretching and humeral head positioner and propeller muscles strengthening for 30 days (3 sessions every week). Clinical assessment of shoulder function was performed with visual analog scale score for pain (0-100), Oxford Shoulder Score (OSS), and Constant-Murley Score (CS). Overall, patients were examined at baseline, week 2, week 4, week 12, and week 24. Statistical significance was set at 5 % (p  0.05), week 12 (p > 0.05), and week 24 (p > 0.05). CS and OSS in the HA group increased significantly at week 2 (p  0.05). A significant improvement of CS and OSS we found in the Physio group at week 2 (p  0.05). Subacromial HA injections could be an effective and safe alternative treatment for patients suffering from RC tendinopathy. We believe that the results of this study are encouraging but not lasting and we might suppose that a series of three to four subacromial sodium hyaluronate injections could provide good mid- and long-term clinical benefits.

Effectiveness of Standardized Physiotherapy Exercises for Patients With Difficulty Returning to Usual Activities After Decompression Surgery for Subacromial Impingement Syndrome

DEFF Research Database (Denmark)

Christiansen, David Høyrup; Frost, Poul; Falla, Deborah

2016-01-01

BACKGROUND: Little is known about the effectiveness of exercise programs after decompression surgery for subacromial impingement syndrome. For patients with difficulty returning to usual activities, special efforts may be needed to improve shoulder function. OBJECTIVE: The purpose of this study w...

Ultrasound-Guided Percutaneous Electrolysis and Eccentric Exercises for Subacromial Pain Syndrome: A Randomized Clinical Trial

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José L. Arias-Buría

2015-01-01

Full Text Available Objective. To compare effects of ultrasound- (US- guided percutaneous electrolysis combined with an eccentric exercise program of the rotator cuff muscles in subacromial pain syndrome. Methods. Thirty-six patients were randomized and assigned into US-guided percutaneous electrolysis (n=17 group or exercise (n=19 group. Patients were asked to perform an eccentric exercise program of the rotator cuff muscles twice every day for 4 weeks. Participants assigned to US-guided percutaneous electrolysis group also received the application of galvanic current through acupuncture needle on each session once a week (total 4 sessions. Shoulder pain (NPRS and disability (DASH were assessed at baseline, after 2 sessions, and 1 week after the last session. Results. The ANOVA revealed significant Group∗Time interactions for shoulder pain and disability (all, P<0.01: individuals receiving US-guided percutaneous electrolysis combined with the eccentric exercises experienced greater improvement than those receiving eccentric exercise alone. Conclusions. US-guided percutaneous electrolysis combined with eccentric exercises resulted in small better outcomes at short term compared to when only eccentric exercises were applied in subacromial pain syndrome. The effect was statistically and clinically significant for shoulder pain but below minimal clinical difference for function. Future studies should investigate the long-term effects and potential placebo effect of this intervention.

Ultrasound-Guided Application of Percutaneous Electrolysis as an Adjunct to Exercise and Manual Therapy for Subacromial Pain Syndrome: a Randomized Clinical Trial.

Science.gov (United States)

de-Miguel-Valtierra, Lorena; Salom-Moreno, Jaime; Fernández-de-Las-Peñas, César; Cleland, Joshua A; Arias-Buría, José L

2018-05-16

This randomized clinical trial compared the effects of adding US-guided percutaneous electrolysis into a program consisting of manual therapy and exercise on pain, related-disability, function and pressure sensitivity in subacromial pain syndrome. Fifty patients with subacromial pain syndrome were randomized into manual therapy and exercise or percutaneous electrolysis group. All patients received the same manual therapy and exercise program, one session per week for 5 consecutive weeks. Patients assigned to the electrolysis group also received the application of percutaneous electrolysis at each session. The primary outcome was Disabilities of the Arm, Shoulder and Hand (DASH). Secondary outcomes included pain, function (Shoulder Pain and Disability Index-SPADI) pressure pain thresholds (PPTs) and Global Rating of Change (GROC). They were assessed at baseline, post-treatment, and 3, and 6 months after treatment. Both groups showed similar improvements in the primary outcome (DASH) at all follow-ups (P=0.051). Subjects receiving manual therapy, exercise, and percutaneous electrolysis showed significantly greater changes in shoulder pain (P0.91) for shoulder pain and function at 3 and 6 months in favour of the percutaneous electrolysis group. No between-groups differences in PPT were found. The current clinical trial found that the inclusion of US-guided percutaneous electrolysis in combination with manual therapy and exercise resulted in no significant differences for related-disability (DASH) than the application of manual therapy and exercise alone in patients with subacromial pain syndrome. Nevertheless, differences were reported for some secondary outcomes such as shoulder pain and function (SPADI). Whether or not these effects are reliable should be addressed in future studies Perspective This study found that the inclusion of US-guided percutaneous electrolysis into a manual therapy and exercise program resulted in no significant differences for disability

Contamination Effects Due to Space Environmental Interactions

Science.gov (United States)

Chen, Philip T.; Paquin, Krista C. (Technical Monitor)

2001-01-01

Molecular and particulate contaminants are commonly generated from the orbital spacecraft operations that are under the influence of the space environment. Once generated, these contaminants may attach to the surfaces of the spacecraft or may remain in the vicinity of the spacecraft. In the event these contaminants come to rest on the surfaces of the spacecraft or situated in the line-of-sight of the observation path, they will create various degrees of contamination effect which may cause undesirable effects for normal spacecraft operations, There will be circumstances in which the spacecraft may be subjected to special space environment due to operational conditions. Interactions between contaminants and special space environment may alter or greatly increase the contamination effect due to the synergistic effect. This paper will address the various types of contamination generation on orbit, the general effects of the contamination on spacecraft systems, and the typical impacts on the spacecraft operations due to the contamination effect. In addition, this paper will explain the contamination effect induced by the space environment and will discuss the intensified contamination effect resulting from the synergistic effect with the special space environment.

Suture slippage in knotless suture anchors resulting in subacromial-subdeltoid bursitis.

Science.gov (United States)

Hayeri, Mohammad Reza; Keefe, Daniel T; Chang, Eric Y

2016-05-01

Rotator cuff repair using a suture bridge and knotless suture anchors is a relatively new, but increasingly used technique. The suture bridge technique creates an anatomically similar and more secure rotator cuff repair compared with conventional arthroscopic techniques and the use of knotless anchors eliminates the challenges associated with knot tying during arthroscopic surgery. However, previous in vitro biomechanical tests have shown that the hold of the suture in a knotless suture anchor is far lower than the pullout strength of the anchor from bone. Up until now slippage has been a theoretical concern. We present a prospectively diagnosed case of in vivo suture loosening after rotator cuff repair using a knotless bridge technique resulting in subacromial-subdeltoid bursitis.

Pathological Fracture of Clavicle Following Sub-Acromial Decompression-Infraclavicular Compartment Syndrome?

Directory of Open Access Journals (Sweden)

S Mukhopadhyay

2009-11-01

Full Text Available A 34-year-old factory worker presented with pain and weakness of the left shoulder following a fall on ice on her left shoulder. An ultrasound scan of the shoulder taken 4 months after injury showed small partial articular surface tear of the supraspinatus tendon. Ten days following subacromial decompression she suffered a pathological fracture of her left clavicle. MRI, CT, and isotope bone scans showed no evidence of malignancy or infection but a collection of fluid was noted underlying the clavicle communicating to the acromioclavicular joint. Ultrasound scan guided aspiration of 20 millilitres of bloodstained fluid underlying the clavicle resulted in gradual recovery and adequate healing of the fracture.

Ultrasound measurement of rotator cuff thickness and acromio-humeral distance in the diagnosis of subacromial impingement syndrome of the shoulder.

Science.gov (United States)

Cholewinski, Jerzy J; Kusz, Damian J; Wojciechowski, Piotr; Cielinski, Lukasz S; Zoladz, Miroslaw P

2008-04-01

The usefulness of ultrasound measurements in the diagnosis of the subacromial impingement syndrome of the shoulder was evaluated. Fifty-seven patients with unilateral symptoms of the impingement syndrome underwent ultrasound examination of both shoulder joints, which included assessment of rotator cuff integrity, measurement of rotator cuff thickness and the distance between the infero-lateral edge of acromion and the apex of the greater tuberosity of humerus (AGT distance) in the standard ultrasonographic positions. As a control group, 36 volunteers (72 shoulders) with no history of shoulder pain were examined sonographically. Ultrasonographic assessment of humeral head elevation, measured as the AGT distance, proved to be useful in establishing the diagnosis of the subacromial impingement syndrome of the shoulder. A difference in rotator cuff thickness of more than 1.1 mm and a difference in the AGT distance of more than 2.1 mm between both shoulder joints may reflect dysfunction of rotator cuff muscles.

Rotator cuff healing after continuous subacromial bupivacaine infusion: an in vivo rabbit study

Science.gov (United States)

FRIEL, NICOLE A.; WANG, VINCENT M.; SLABAUGH, MARK A.; WANG, FANCHIA; CHUBINSKAYA, SUSAN; COLE, BRIAN J.

2013-01-01

Background The objective of this study was to evaluate the effects of continuous subacromial bupivacaine infusion on supraspinatus muscle and rotator cuff tendon healing via gross, biomechanical, and histologic analyses. Methods Thirty-three New Zealand White rabbits underwent unilateral supraspinatus transection and rotator cuff repair (RCR). Rabbits were assigned to 1 of 3 groups: (1)RCR only, (2)RCR with continuous saline infusion for 48 hours, or (3)RCR with continuous 0.25% bupivacaine with epinephrine (1:200,000) infusion for 48 hours. Rabbits were sacrificed at either 2 (for histologic assessment) or 8 weeks post-operatively (for biomechanical and histologic assessment). Results Tensile testing showed significantly higher load to failure in intact tendons compared to repaired tendons (pBupivacaine groups. Histologically, the enthesis of repaired tendons showed increased cellularity and disorganized collagen fibers compared to intact tendons, with no differences between treatment groups. Muscle histology demonstrated scattered degenerative muscle fibers at 2 weeks in both RCR Saline and RCR Bupivacaine, but no degeneration was noted at 8 weeks. Conclusions The healing supraspinatus tendons exposed to bupivacaine infusion showed similar histologic and biomechanical characteristics compared to untreated and saline infused RCR groups. Muscle histology showed fiber damage at 2 weeks for both the saline and bupivacaine treated groups, with no apparent disruption at 8 weeks, suggesting a recovery process. Therefore, subacromial bupivacaine infusion in this rabbit rotator cuff model does not appear to impair muscle or tendon following acute injury and repair. Level Of Evidence Basic science study PMID:22818894

The Use of Physiotherapy among Patients with Subacromial Impingement Syndrome

DEFF Research Database (Denmark)

Christiansen, David Høyrup; Frost, Poul; Frich, Lars Henrik

2016-01-01

BACKGROUND: Physiotherapy with exercises is generally recommended in the treatment of patients with subacromial impingement syndrome (SIS). OBJECTIVE: We aimed to investigate the use of physiotherapy in patients with SIS in Danish hospital settings as part of initial non-surgical treatment...... and after SIS-related surgery and to evaluate to which extent sex, socio-demographic and clinical factors predict the use of physiotherapy. METHODS: Using national health registers, we identified 57,311 patients who had a first hospital contact with a diagnosis of ICD-10, groups M75.1-75.9, 1 July 2007...... to 30 June 2011. Records of physiotherapy were extracted within 52 weeks after first contact (or until surgery), and for surgically treated patients within 26 weeks after surgery. Predictors of the use of physiotherapy after first contact and after surgery were analysed as time-to-event. RESULTS: Within...

Exercises versus arthroscopic decompression in patients with subacromial impingement: a randomised, controlled study in 90 cases with a one year follow up

DEFF Research Database (Denmark)

Haahr, J. P.; Ostergaard, S.; Dalsgaard, J.

2005-01-01

, the difference being non-significant. No group differences in mean pain and dysfunction score improvement were found. CONCLUSIONS: Surgical treatment of rotator cuff syndrome with subacromial impingement was not superior to physiotherapy with training. Further studies are needed to qualify treatment choice...

The clinical and sonographic effects of kinesiotaping and exercise in comparison with manual therapy and exercise for patients with subacromial impingement syndrome: a preliminary trial.

Science.gov (United States)

Kaya, Derya Ozer; Baltaci, Gul; Toprak, Ugur; Atay, Ahmet Ozgur

2014-01-01

The purpose of this study was to compare the effects of manual therapy with exercise to kinesiotaping with exercise for patients with subacromial impingement syndrome. Randomized clinical before and after trial was used. Fifty-four patients diagnosed as having subacromial impingement syndrome who were referred for outpatient treatment were included. Eligible patients (between 30 and 60 years old, with unilateral shoulder pain) were randomly allocated to 2 study groups: kinesiotaping with exercise (n = 28) or manual therapy with exercise (n = 26). In addition, patients were advised to use cold packs 5 times per day to control for pain. Visual analog scale for pain, Disability of Arm and Shoulder Questionnaire for function, and diagnostic ultrasound assessment for supraspinatus tendon thickness were used as main outcome measures. Assessments were applied at the baseline and after completing 6 weeks of related interventions. At the baseline, there was no difference between the 2 group characteristics (P > .05). There were significant differences in both groups before and after treatment in terms of pain decrease and improvement of Disability of Arm and Shoulder Questionnaire scores (P .05). The only difference between the groups was at night pain, resulting in favor of the kinesiotaping with exercise group (P kinesiotaping with exercise and manual therapy with exercise. Both treatments may have similar results in reducing pain and disability in subacromial impingement in 6 weeks. Copyright © 2014 National University of Health Sciences. Published by Elsevier Inc. All rights reserved.

Targeted knockout of TNF-α by injection of lentivirus-mediated siRNA into the subacromial bursa for the treatment of subacromial bursitis in rats.

Science.gov (United States)

Wang, Yi; Li, Quan; Wei, Xianzhao; Xu, Jie; Chen, Qi; Song, Shuang; Lu, Zhe; Wang, Zimin

2015-09-01

Subacromial bursitis (SAB) is the major source of pain in rotator cuff disease. Although multiple investigations have provided support for the role of inflammatory cytokines in SAB, few have focussed on the use these cytokines in the treatment of SAB. The aim of the present study was to observe the therapeutic efficacy of lentivirus‑mediated RNA interference (RNAi) on carrageenan‑induced SAB by injecting lentivirus‑tumor necrosis factor (TNF)‑α‑RNAi expressing TNF‑α small interfering (si)RNA. Using screened siRNA segments, an siRNA was designed. A lentivirus vector expressing siRNA was established and packed as lentivirus particles. A lentivirus that expressed the negative sequence was used as a lentivirus‑negative control (NC). The carrageenan‑induced SAB model was established in 32 male Sprague‑Dawley rats. The modeled rats were randomly assigned to four groups: Lentivirus‑RNAi treatment group, lentivirus‑NC group, SAB group and phosphate‑buffered saline (PBS) blank control group. The lentivirus was injected (1x10(7) transducing units) into the subacromial bursa of the rats in the lentivirus‑RNAi group and lentivirus‑NC group, whereas 100 µl PBS was injected at the same site in the SAB group and the PBS blank control group. At 5 weeks following injection, the animals were sacrificed and venous blood was obtained. The effect of TNF‑α interference and the expression of inflammatory cytokines were determined by reverse transcription‑quantitative polymerase chain reaction, western blotting, hematoxylin and eosin staining, Van Gieson's staining and immunofluorescence. The expression of TNF‑α was decreased in the lentivirus‑TNF‑α‑RNAi group compared with that in the SAB group. Morphological observations revealed that the number of inflammatory cells were reduced and damage to tendon fibers was attenuated in this group, suggesting that the downregulation of the protein expression levels of TNF‑α‑associated nuclear

Muscle Activation Pattern during Selected Functional Task in Shoulder Impingement Syndrome vs. Normal Subjects

Directory of Open Access Journals (Sweden)

Mehrnaz Kajbaf-Vala

2009-10-01

Conclusion: Changes in muscle recruitment pattern are task dependent that this may be due to direction of movement and axial compression loading in subacromial space. Among all selected exercises in D2E (Diagonal 2 Extension minimum changes and in tripod maximum changes (in time domain were seen.

Effectiveness of Standardized Physical Therapy Exercises for Patients With Difficulty Returning to Usual Activities After Decompression Surgery for Subacromial Impingement Syndrome: Randomized Controlled Trial.

Science.gov (United States)

Christiansen, David Høyrup; Frost, Poul; Falla, Deborah; Haahr, Jens Peder; Frich, Lars Henrik; Andrea, Linda Christie; Svendsen, Susanne Wulff

2016-06-01

Little is known about the effectiveness of exercise programs after decompression surgery for subacromial impingement syndrome. For patients with difficulty returning to usual activities, special efforts may be needed to improve shoulder function. The purpose of this study was to evaluate the effectiveness at 3 and 12 months of a standardized physical therapy exercise intervention compared with usual care in patients with difficulty returning to usual activities after subacromial decompression surgery. A multicenter randomized controlled trial was conducted. The study was conducted in 6 public departments of orthopedic surgery, 2 departments of occupational medicine, and 2 physical therapy training centers in Central Denmark Region. One hundred twenty-six patients reporting difficulty returning to usual activities at the postoperative clinical follow-up 8 to 12 weeks after subacromial decompression surgery participated. A standardized exercise program consisting of physical therapist-supervised individual training sessions and home training was used. The primary outcome measure was the Oxford Shoulder Score. Secondary outcome measures were the Constant Score and the Fear-Avoidance Beliefs Questionnaire. At 3 and 12 months, follow-up data were obtained for 92% and 83% of the patients, respectively. Intention-to-treat analyses suggested a between-group difference on the Oxford Shoulder Score favoring the exercise group at 3 months, with an adjusted mean difference of 2.0 (95% confidence interval=-0.5, 4.6), and at 12 months, with an adjusted mean difference of 5.8 (95% confidence interval=2.8, 8.9). Significantly larger improvements for the exercise group were observed for most secondary and supplementary outcome measures. The nature of the exercise intervention did not allow blinding of patients and care providers. The standardized physical therapy exercise intervention resulted in statistically significant and clinically relevant improvement in shoulder pain and

Patients who are candidates for subacromial decompression have more pronounced range of motion deficits, but do not differ in self-reported shoulder function, strength or pain compared to non-candidates

DEFF Research Database (Denmark)

Witten, Adam; Clausen, Mikkel B; Thorborg, Kristian

2018-01-01

-reported shoulder function, shoulder strength, ROM, and pain in patients with SIS considered candidates and non-candidates for subacromial decompression (SAD). METHOD: Self-reported shoulder function (Q-DASH and SPADI), maximum isometric muscle strength in shoulder abduction (Abd-strength) and external rotation (ER...... or non-candidates for SAD based on their consultation with an orthopedic specialist blinded to test results and self-reported shoulder function. All outcomes and age, gender, weight and duration of symptoms were compared using the unpaired t test or Mann-Whitney's U test as appropriate. RESULTS: One.......3 vs. 3.7, p = 0.02, effect size = 0.21). No other differences were found between the groups. CONCLUSION: A decrease in abduction and internal rotation range of motion, and increased pain during maximal abduction strength effort are associated with being considered a candidate for subacromial...

Arthroscopic Treatment of a Case with Concomitant Subacromial and Subdeltoid Synovial Chondromatosis and Labrum Tear

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Nevres Hurriyet Aydogan

2013-01-01

Full Text Available Synovial chondromatosis is a disease that seldomly seen in shoulder joint and is related to benign synovial proliferation and synchronous chondral tissue formation within the joint cavity. Patients suffer from progressive restriction of range of motion and shoulder pain. Extra-articular involvement is an extremely rare condition. Degenerative osteoarthritis, joint subluxation, and bursitis are common complications in untreated patients. Open or arthroscopic surgery is suitable while there is no consensus related to superiority of different approaches. We presented an arthroscopic treatment of a male patient, 48 years old with labrum tear and synovial chondromatosis localized in subacromial and subdeltoid region. Advantages of arthroscopic surgery in the presence of intra- and extra-articular combined pathologies are also discussed.

The effectiveness of injections of hyaluronic acid or corticosteroid in patients with subacromial impingement: a three-arm randomised controlled trial.

Science.gov (United States)

Penning, L I F; de Bie, R A; Walenkamp, G H I M

2012-09-01

A total of 159 patients (84 women and 75 men, mean age of 53 (20 to 87)) with subacromial impingement were randomised to treatment with subacromial injections using lidocaine with one of hyaluronic acid (51 patients), corticosteroid (53 patients) or placebo (55 patients). Patients were followed up for 26 weeks. The primary outcome was pain on a visual analogue score (VAS), and secondary outcomes included the Constant Murley score, shoulder pain score, functional mobility score, shoulder disability questionnaire and pain-specific disability score. The different outcome measures showed similar results. After three, six and 12 weeks corticosteroid injections were superior to hyaluronic acid injections and only at six weeks significantly better than placebo injections. The mean short-term reduction in pain on the VAS score at 12 weeks was 7% (SD 2.7; 97.5% confidence interval (CI) 0.207 to 1.55; p = 0.084) in the hyaluronic acid group, 28% (SD 2.8; 97.5% CI 1.86 to 3.65; p hyaluronic acid group, 72% (38 of 53) of those in the corticosteroid group and 69% (38 of 55) of those in the placebo group. We were not able to show a convincing benefit from hyaluronic acid injections compared with corticosteroid or placebo injections. Corticosteroid injections produced a significant reduction in pain in the short term (three to 12 weeks), but in the long term the placebo injection produced the best results.

Static deformation of two welded monoclinic elastic half-spaces due ...

Indian Academy of Sciences (India)

M. Senthilkumar (Newgen Imaging) 1461 1996 Oct 15 13:05:22

Static deformation of two monoclinic elastic half-spaces in welded contact due to a long inclined strike-slip fault situated in one of the half-spaces is studied analytically and numerically. Closed- form algebraic expressions for the displacement at any point of the medium are obtained. The variation of the displacement at the ...

PERBANDINGAN ANTARA KOMBINASI LATIHAN STABILISASI BAHU DAN TRAKSI HUMERUS KE INFERIOR DENGAN KOMBINASI LATIHAN FUNGSIONAL BAHU DAN TRAKSI HUMERUS KE INFERIOR DALAM MENURUNKAN DISABILITAS BAHU DAN LENGAN PADA SUBACROMIAL IMPINGEMENT SYNDROME MAHASISWA AKAD

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Mawaddah -

2015-08-01

Full Text Available Shoulder impingement causing interference on the motion of the shoulder joint activities and result in functional activity disorder. These injuries usually are caused by faulty movement, overuse, poor posture, occupational factors and trauma. This will cause a burden on one part of the body and cause imbalances in anatomy, which will eventually lead to disruption of the body that experienced work. This study aimed to investigate the effect of functional shoulder exercise and traction humerus to inferior with shoulder stabilization exercises and traction humerus to inferior to the decline in the shoulder and arm disabilities in subacromial impingement syndrome. This research method was experimental clinical trials with pre test and post test group design. Population student Academy Physiotherapy Widya Husada Semarang, which consists of 3 men and 12 women, aged between 18-21 years, divided into two groups. Group I was given Shoulder Stabilization exercises and Traction humerus to Inferior (n=7 and group II Functional Shoulder Exercise and Traction humerus to Inferior (n=8. This research was conducted for 3 weeks. Measurement of the value of disability shoulder and arm by using the Shoulder Pain and Disability Index (SPADI. The test results on the group I average value pre 34.17, SB = 6.31, and the average value of post 11.54, SB = 4.02, p = 0.001 found significant differences obtained test results paired sample t-test, and testing group II average value pre 40.18, SB = 3.53, and the average value of post 7.82, SB = 1.57, p = 0.001 found significant differences obtained test results paired sample t-test. Comparison of Group I and II, p = 0.005 there were significant differences, test results obtained independent sample t-test. Conclusions: The combination of shoulder stabilization exercises and traction humerus to inferior can reduce disability shoulder and arm on subacromial impingement syndrome. The combination functional shoulder exercise and

Lipoma arborescens: rare case of rotator cuff tear associated with the presence of lipoma arborescens in the subacromial-subdeltoid and glenohumeral bursa

OpenAIRE

Benegas, Eduardo; Ferreiro Neto, Arnaldo Amado; Teodoro, Daniel Sabatini; Silva, Marcos Vinícius Muriano da; Oliveira, Augusto Medaglia de; Filippi, Renée Zon; Prada, Flávia de Santis

2012-01-01

Lipoma arborescens é uma condição rara de moléstia intra-articular, usualmente monoarticular, caracterizada por extensa proliferação dos vilos sinoviais e hiperplasia da gordura subsinovial. O tecido sinovial é progressivamente substituído por células maduras de gordura na membrana sinovial. O presente trabalho é o relato de caso de uma condição rara de lipoma arborescens tanto intra-articular (glenoumeral) como da bursa subacromial-subdeltoide além de ruptura do tendão do supraespinhoso. As ...

Muscle shortening maneuver and not topical anti-inflammatory therapy is effective in reducing the width of subacromial-subdeltoid bursa in shoulder impingement syndrome

Science.gov (United States)

Melchiorre, Daniela; Lippi, Paolo; Marchi, Alberto; Maresca, Marco; Bravi, Riccardo; Eros, Quarta; Lazzerini, Patrizia; Bagni, Maria Angela

2018-04-01

Aim of the study was to compare the efficacy of a muscle shortening maneuver (MSM) with the efficacy of a topical NSAID (flurbiprofen) in patients with subacromial impingement syndrome (SIS). The effects of these therapies were evaluated by sonographic exam (US). SIS was diagnosed by US in 78 patients with painful shoulder. Thirty patients (first group) were treated with topical flurbiprofen for 15 days. Forty-eight patients (second group) were treated with MSM, which was performed once. The shoulder was analyzed in all patients by US before and after treatment. Before treatment and 15 days after treatment, pain by Visual Analogue Scale (VAS), range of motion (ROM) and Neer's Test were evaluated. Pain was decreased by both treatments. In only 8 patients of the first group, the encroachment of acromion into the rotator cuff was no more detectable by US after the treatment; ROM increased (> 45°) only in 11 patients (36%) and the width of subacromial-subdeltoid bursa (SSB) was not significantly reduced. At variance with the results obtained in the first group, in all patients of the second group the encroachment of acromion was no more detectable by US, ROM increased (> 45°) and the width of SSB was significantly reduced after the maneuver. Both topical flurbiprofen and MSM were helpful in pain control, but better results, with decrease of width of SSB assessed by US, were obtained by MSM.

Density perturbations due to the inhomogeneous discrete spatial structure of space-time

International Nuclear Information System (INIS)

Wolf, C.

1998-01-01

For the case that space-time permits an inhomogeneous discrete spatial structure due to varying gravitational fields or a foam-like structure of space-time, it is demonstrated that thermodynamic reasoning implies that matter-density perturbations will arise in the early universe

Lipoma arborescens: caso raro de ruptura do manguito rotador associado à presença de lipoma arborescens na bursa subacromial-subdeltoidea e glenoumeral Lipoma arborescens: rare case of rotator cuff tear associated with the presence of lipoma arborescens in the subacromial-subdeltoid and glenohumeral bursa

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Eduardo Benegas

2012-01-01

Full Text Available Lipoma arborescens é uma condição rara de moléstia intra-articular, usualmente monoarticular, caracterizada por extensa proliferação dos vilos sinoviais e hiperplasia da gordura subsinovial. O tecido sinovial é progressivamente substituído por células maduras de gordura na membrana sinovial. O presente trabalho é o relato de caso de uma condição rara de lipoma arborescens tanto intra-articular (glenoumeral como da bursa subacromial-subdeltoide além de ruptura do tendão do supraespinhoso. As apresentações clínicas, histológicas e radiográficas assim como o tratamento são discutidos no presente estudo. A apresentação do caso contempla também a avaliação radiográfica, ressonância magnética e exame patológico. Apesar do lipoma arborescens ser uma condição rara, tal hipótese deve ser considerada frente a um caso com hiperproliferação sinovial e lipossubstituição da sinovial.Lipoma arborescens is a rare intra-articular disease that is usually monoarticular and is characterized by extensive proliferation of the synovial villi and hyperplasia of the subsynovial fat. The synovial tissue is progressively replaced by mature fat cells in the synovial membrane. The present study reports a case of a rare condition of lipoma arborescens that was simultaneously intra-articular (glenohumeral joint and in the subacromial-subdeltoid bursa, in association with a torn supraspinatus tendon. The clinical, histological and radiographic presentations and treatment are discussed here. The description of this case includes radiographic and magnetic resonance evaluations and pathological examination. Although lipoma arborescens is a rare condition, it should be taken into consideration in cases presenting synovial hyperproliferation and synovial fat replacement.

Isolated subacromial bursal fluid on MRI of the shoulder in symptomatic patients: correlation with arthroscopic findings

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Monu, J.U.V. [Dept. of Radiology, Bowman Gray School of Medicine, Wake Forest Univ., Winston-Salem, NC (United States); Pruett, S. [Bowman Gray School of Medicine, Wake Forest Univ., Winston-Salem, NC (United States); Vanarthos, W.J. [Dept. of Radiology, Bowman Gray School of Medicine, Wake Forest Univ., Winston-Salem, NC (United States); Pope, T.L. Jr. [Dept. of Radiology, Bowman Gray School of Medicine, Wake Forest Univ., Winston-Salem, NC (United States)

1994-10-01

Fluid in the subacromial bursa (SAB) is a common finding on magnetic resonance (MR) images of the shoulder, and the implications of this finding have not been clarified. We retrospectively reviewed and correlated the MR features with arthroscopic findings in 21 symptomatic patients who had fluid in the SAB on MR imaging without demonstrable rotator cuff tear. Rotator cuff impingement was the most frequent surgical finding (42.9%). Other frequent surgical observations were glenbid labrum abnormality (28.6%), bursitis (19%), and supraspinatus tendinitis (14.3%). Distribution of acromial types was similar to that reported by Bigliani et al., and impingement was evenly distributed among acromial types in our study population. We conclude that in our patient population group the MR finding of isolated SAB fluid in symptomatic patients is highly likely to be associated with the finding of other abnormalities in the shoulder joint at surgery. (orig.)

Isolated subacromial bursal fluid on MRI of the shoulder in symptomatic patients: correlation with arthroscopic findings

International Nuclear Information System (INIS)

Monu, J.U.V.; Pruett, S.; Vanarthos, W.J.; Pope, T.L. Jr.

1994-01-01

Fluid in the subacromial bursa (SAB) is a common finding on magnetic resonance (MR) images of the shoulder, and the implications of this finding have not been clarified. We retrospectively reviewed and correlated the MR features with arthroscopic findings in 21 symptomatic patients who had fluid in the SAB on MR imaging without demonstrable rotator cuff tear. Rotator cuff impingement was the most frequent surgical finding (42.9%). Other frequent surgical observations were glenbid labrum abnormality (28.6%), bursitis (19%), and supraspinatus tendinitis (14.3%). Distribution of acromial types was similar to that reported by Bigliani et al., and impingement was evenly distributed among acromial types in our study population. We conclude that in our patient population group the MR finding of isolated SAB fluid in symptomatic patients is highly likely to be associated with the finding of other abnormalities in the shoulder joint at surgery. (orig.)

Vascular endothelial growth factor 121 and 165 in the subacromial bursa are involved in shoulder joint contracture in type II diabetics with rotator cuff disease.

Science.gov (United States)

Handa, Akiyoshi; Gotoh, Masafumi; Hamada, Kazutoshi; Yanagisawa, Kazuhiro; Yamazaki, Hitoshi; Nakamura, Masato; Ueyama, Yoshito; Mochida, Joji; Fukuda, Hiroaki

2003-11-01

Vascular endothelial growth factor (VEGF) is a glycoprotein that plays an important role in neovascularization and increases vascular permeability. We reported that VEGF is involved in motion pain of patients with rotator cuff disease by causing synovial proliferation in the subacromial bursa (SAB). The present study investigates whether VEGF is also involved in the development of shoulder contracture in diabetics with rotator cuff disease. We examined 67 patients with rotator cuff disease, including 36 with complete cuff tears, 20 with incomplete tears, and 11 without apparent tears (subacromial bursitis). The patients were into groups according to the presence or absence of diabetes (14 type II diabetics and 53 non-diabetics). Specimens of the synovium of the SAB were obtained from all patients during surgery. Expression of the VEGF gene in the synovium of the subacromial bursa was evaluated by using the reverse transcriptase polymerase chain reaction. The VEGF protein was localized by immunohistochemistry, and the number of vessels was evaluated based on CD34 immunoreactivity. The results showed that VEGF mRNA was expressed in significantly more diabetics (100%, 14/14) than in non-diabetics (70%, 37/53) (P=0.0159, Fisher's test). Investigation of VEGF isoform expression revealed VEGF121 in all 14 diabetics and in 37 of the 53 non-diabetics, VEGF165 in 12 of the 14 diabetics and in 21 of the 53 non-diabetics, and VEGF189 in 1 of the 14 diabetics and in 2 of the 53 non-diabetics. No VEGF206 was expressed in either group. VEGF protein was localized in both vascular endothelial cells and synovial lining cells. The mean number of VEGF-positive vessels and the vessel area were also significantly greater in the diabetics (pshoulder joint contracture were more common in the diabetics (P=0.0329 and P=0.073, respectively; Fisher's test). The mean preoperative range of shoulder motion significantly differed in terms of elevation between two groups: 103.8 degrees in

Effectiveness of ultrasound-guided injections combined with shoulder exercises in the treatment of subacromial adhesive bursitis.

Science.gov (United States)

Gasparre, Giuseppe; Fusaro, Isabella; Galletti, Stefano; Volini, Silvia; Benedetti, Maria Grazia

2012-05-01

The aim of this study was to evaluate whether the association of exercises for the shoulder with ultrasound-guided injection into the bursa significantly improves the treatment outcome in adhesive bursitis. Two groups of 35 patients, one treated with ultrasound-guided injection (UGI) and the other one with ultrasound-guided injection and home exercise program (UGI-exercise) for 1 month, were assessed for pain and shoulder function before treatment, 1 and 3 months post-treatment. Fourteen patients in UGI group and 23 patients in the UGI-exercises group were completely free of pain after 1 month (p = 0.031). At 3 months' follow-up, patients in the UGI-exercise group showed a significant improvement with respect to the other group (p = 0.005). No differences were found in function assessment. The UGI combined with shoulder exercises in the treatment of subacromial adhesive bursitis is effective to ensure a more frequent complete pain relief in the medium term.

Surgery for subacromial impingement syndrome in relation to intensities of occupational mechanical exposures across 10-year exposure time windows

DEFF Research Database (Denmark)

Dalbøge, Annett; Frost, Poul; Andersen, Johan Hviid

2018-01-01

OBJECTIVES: We aimed to identify intensities of occupational mechanical exposures (force, arm elevation and repetition) that do not entail an increased risk of surgery for subacromial impingement syndrome (SIS) even after prolonged durations of exposure. Additionally, we wanted to evaluate...... if exposure to hand-arm vibration (HAV) is an independent risk factor. METHODS: We used data from a register-based cohort study of the entire Danish working population (n=2 374 403). During follow-up (2003-2008), 14 118 first-time events of surgery for SIS occurred. For each person, we linked register...... of exposure at specific intensities above minimal (low, medium and high). We used a logistic regression technique equivalent to discrete survival analysis adjusting for cumulative effects of other mechanical exposures. RESULTS: We found indications of safe exposure intensities for repetition (median angular...

SHORT-TERM EFFECTS OF INSTRUMENT-ASSISTED SOFT TISSUE MOBILIZATION ON PAIN FREE RANGE OF MOTION IN A WEIGHTLIFTER WITH SUBACROMIAL PAIN SYNDROME.

Science.gov (United States)

Coviello, Joseph Paul; Kakar, Rumit Singh; Reynolds, Timothy James

2017-02-01

While there is limited evidence supporting the use of soft tissue mobilization techniques for Subacromial Pain Syndrome (SAPS), synonymous with subacromial impingement syndrome, previous studies have reported successful outcomes using soft tissue mobilization as a treatment technique. The purpose of this case report is to document the results of Instrument-Assisted Soft Tissue Mobilization (IASTM) for the treatment of SAPS. Diagnosis was reached based on the subject's history, tenderness to palpation, and four out of five positive tests in the diagnostic cluster. Treatment consisted of three visits where the IASTM technique was applied to the pectoral muscles as well as periscapular musculature followed by retesting pain-free shoulder flexion active range of motion (AROM) and Numerical Pain Rating Scale (NPRS) during active shoulder flexion. Scapulothoracic mobilization and stretching were performed after AROM measurement. The subject reported an NPRS of 0/10 and demonstrated improvements in pain free flexion AROM in each of the three treatment sessions post-IASTM: 85 ° to 181 °, 110 ° to 171 °, and 163 ° to 174 ° with some carryover in pain reduction and pain free AROM to the next treatment. Through three treatments, DASH score improved by 17.34%, Penn Shoulder Score improved 29%, worst NPRS decreased from 4/10 to 0/10, and a GROC score of 6. IASTM may have a beneficial acute effect on pain free shoulder flexion. In conjunction with scapulothoracic mobilizations and stretching, IASTM may improve function, decrease pain, and improve patient satisfaction. While this technique will not ameliorate the underlying pathomechanics contributing to SAPS, it may serve as a valuable tool to restore ROM and decrease pain allowing the patient to reap the full benefits of a multi-modal treatment approach. 5.

Subacromial triamcinolone acetonide, hyaluronic acid and saline injections for shoulder pain an RCT investigating the effectiveness in the first days.

Science.gov (United States)

Penning, Ludo I F; de Bie, Rob A; Walenkamp, Geert H I M

2014-10-23

Subacromial impingement is a common cause of shoulder complaints in general practice. When the initial treatment with acetaminophen and low dose Non Steroidal Anti Inflammatory Drugs fails, triamcinolone acetonide injections are commonly used. Triamcinolone acetonide injections are effective at four to six weeks. Little is known about the pain relief effect of triamcinolone acetonide injections in the first days after injection and the effect of repeated injection. In this study we investigate the effect of triamcinolone acetonide injections compared to hyaluronic acid and NaCl injections using a pain diary. 159 Patients recruited for an RCT comparing the effect of subacromial injections of triamcinolone acetonide, hyaluronic acid and sodium chloride (NaCl) were used in this study. They were blinded for their treatment and could receive up to three injections. Primary outcome consisted of the patient perceived pain on a VAS score recorded on a daily basis during 21 days following injection. Secondary outcome consisted of the amount of taken escape medication following injection and adverse effects. All patients received the first injection. 150 patients also received the second and third injections. 97% Of the paper and pencil pain diaries were returned for data analysis.The triamcinolone acetonide group showed the largest decrease in pain on the VAS scores after injection compared to the hyaluronic acid and NaCl group in the first week after injection. The reduction in pain was best achieved after the first injection, the second triamcinolone acetonide injection showed a further reduction in pain. The third triamcinolone acetonide injection only showed a slight improvement in pain reduction. In this study we could show a booster effect in pain reduction after repeated triamcinolone acetonide injection. The triamcinolone acetonide group showed a faster reduction in pain after injection compared to the hyaluronic acid and NaCl group. The effect was best seen after

Calcific tendinitis of the rotator cuff: a randomized controlled trial of ultrasound-guided needling and lavage versus subacromial corticosteroids.

Science.gov (United States)

de Witte, Pieter Bas; Selten, Jasmijn W; Navas, Ana; Nagels, Jochem; Visser, Cornelis P J; Nelissen, Rob G H H; Reijnierse, Monique

2013-07-01

Calcific tendinitis of the rotator cuff (RCCT) is frequently diagnosed in patients with shoulder pain, but there is no consensus on its treatment. To compare 2 regularly applied RCCT treatments: ultrasound (US)-guided needling and lavage (barbotage) combined with a US-guided corticosteroid injection in the subacromial bursa (subacromial bursa injection [SAI]) (group 1) versus an isolated SAI (group 2). Randomized controlled trial; Level of evidence, 1. Patients were randomly assigned to the 2 groups. Shoulder function was assessed before treatment and at regular follow-up intervals (6 weeks and 3, 6, and 12 months) using the Constant shoulder score (CS, primary outcome), the Western Ontario Rotator Cuff Index (WORC), and the Disabilities of the Arm, Shoulder and Hand questionnaire (DASH). Additionally, calcification location, size, and Gärtner classification were assessed on radiographs. Results were analyzed using the t test, linear regression, and a mixed model for repeated measures. This study included 48 patients (25 female, 52.1%; mean age, 52.0 ± 7.3 years; 23 patients in group 1) with a mean baseline CS of 68.7 ± 11.9. No patients were lost to follow-up. Four patients in group 1 and 11 in group 2 (P = .06) had an additional barbotage procedure or surgery during the follow-up period because of persisting symptoms and no resorption. At 1-year follow-up, the mean CS in group 1 was 86.0 (95% CI, 80.3-91.6) versus 73.9 (95% CI, 67.7-80.1) in group 2 (P = .005). The mean calcification size decreased by 11.6 ± 6.4 mm in group 1 and 5.1 ± 5.7 mm in group 2 (P = .001). There was total resorption in 13 patients in group 1 and 6 patients in group 2 (P = .07). With regression analyses, correcting for baseline CS and Gärtner type, the mean treatment effect was 20.5 points (P = .05) in favor of barbotage. Follow-up scores were significantly influenced by baseline scores. Results for the DASH and WORC were similar. On average, there was improvement at 1-year follow

The Effect of Platelet-Rich Plasma (PRP on Improvement in Pain and Symptoms of Shoulder Subacromial Impingement Syndrome

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Parisa Nejati

2015-08-01

Full Text Available Abstract Background: Subacromial impingement is one of the most common complaints of shoulder. Treatments include avoiding of painful activities, oral anti-pain drugs, physical therapy modalities, corticosteroid injection and exercise therapy. Some studies have shown that platelet- rich plasma(PRP is effective on tendinitis and tearing of tendons, ligaments and muscles, but evidence that has proved PRP as a conservative treatment in shoulder pathologies is very limited. This study aims to investigate the effect of PRP injection on relieving pain and improving daily function of patients with shoulder impingement syndrome. Materials and Methods: In this clinical trial study, patients older than 40 with pain more than three months were included. If they had three of four positive diagnostic clinical tests of shoulder impingement that were confirmed by shoulder MRI, could be injected PRP twice. The time between injections was 1 month. Pain was measured by visual analog scale (VAS and function was measured by two questionnaires named disabilities of the arm, shoulder and hand (DASH and western Ontario rotator cuff index (WORC. Range of motion (ROM of shoulder was measured in five directions by goniometry . All of these parameters were evaluated before intervention and in 1, 3, 6 months later. Results: with due attention to a six-month folloe-up, PRR injection was effective in pain reduction and improvement of patient's function (p<0.05. Shoulder Rom increased in all directions except external rotation and the power of shoulder muscles was evidently improved statistically in flexion, abduction and internal toration. Conclusion: PRP injection could effectively reduce pain and improve daily activities in patients with shoulder impingement syndrome.

Subacute effects of cervicothoracic spinal thrust/non-thrust in addition to shoulder manual therapy plus exercise intervention in individuals with subacromial impingement syndrome: a prospective, randomized controlled clinical trial pilot study.

Science.gov (United States)

Wright, Alexis A; Donaldson, Megan; Wassinger, Craig A; Emerson-Kavchak, Alicia J

2017-09-01

To determine the subacute effects of cervicothoracic spinal thrust/non-thrust in addition to shoulder non-thrust plus exercise in patients with subacromial pathology. This was a randomized, single blinded controlled trial pilot study. This trial was registered at ClinicalTrials.gov (NCT01753271) and reported according to Consolidated Standards of Reporting Trials requirements. Patients were randomly assigned to either shoulder treatment plus cervicothoracic spinal thrust/non-thrust or shoulder treatment-only group. Primary outcomes were average pain intensity (Numeric Pain Rating Scale) and physical function (Shoulder Pain and Disability Index) at 2 weeks, 4 weeks, and patient discharge. 18 patients, mean age 43.1(15.8) years satisfied the eligibility criteria and were analyzed for follow-up data. Both groups showed statistically significant improvements in both pain and function at 2 weeks, 4 weeks, and discharge. The between-group differences for changes in pain or physical function were not significant at any time point. The addition of cervicothoracic spinal thrust/non-thrust to the shoulder treatment-only group did not significantly alter improvement in pain or function in patients with subacromial pathology. Both approaches appeared to provide an equally notable benefit. Both groups improved on all outcomes and met the criteria for clinical relevance for both pain and function. 2b.

Shoulder pain: the role of diagnostic injections.

Science.gov (United States)

Larson, H M; O'Connor, F G; Nirschl, R P

1996-04-01

Many different shoulder disorders cause similar symptoms and pain patterns. An accurate diagnosis can generally be made by obtaining a detailed history, performing a comprehensive, directed physical examination and obtaining selected radiographs. Occasionally, shoulder injections can be of great assistance in establishing a clear diagnosis and providing relief of symptoms. Subacromial space injection, acromioclavicular joint injection, intra-articular injection and injection of the biceps tendon are helpful in identifying such disorders as subacromial bursitis, acromioclavicular arthritis, injury to the glenohumeral joint and bicipital tendinitis.

Quantitative and qualitative analyses of subacromial impingement by kinematic open MRI.

Science.gov (United States)

Tasaki, Atsushi; Nimura, Akimoto; Nozaki, Taiki; Yamakawa, Akira; Niitsu, Mamoru; Morita, Wataru; Hoshikawa, Yoshimitsu; Akita, Keiichi

2015-05-01

Quantitative and qualitative kinematic analyses of subacromial impingement by 1.2T open MRI were performed to determine the location of impingement and the involvement of the acromioclavicular joint. In 20 healthy shoulders, 10 sequential images in the scapular plane were taken in a 10-s pause at equal intervals from 30° to maximum abduction in neutral and internal rotation. The distances between the rotator cuff (RC) and the acromion and the acromioclavicular joint were measured. To comprehend the positional relationships, cadaveric specimens were also observed. Although asymptomatic, the RC came into contact with the acromion and the acromioclavicular joint in six and five cases, respectively. The superior RC acted as a depressor for the humeral head against the acromion as the shoulder elevated. The mean elevation angle and distance at the closest position between the RC and the acromion in neutral rotation were 93.5° and 1.6 mm, respectively, while those between the RC and the acromioclavicular joint were 86.7° and 2.0 mm. When comparing this distance and angle, there was no significant difference between the RC to the acromion and to the acromioclavicular joint. The minimum distance between the RC and the acromion was significantly shorter than that between the greater tuberosity and the acromion. The location of RC closest to the acromion and the acromioclavicular joint differed significantly. Although asymptomatic, contact was found between the RC and the acromion and the acromioclavicular joint. The important role of the RC to prevent impingement was observed, and hence, dysfunction of the RC could lead to impingement that could result in a RC lesion. The RC lesions may differ when they are caused by impingement from either the acromion or the acromioclavicular joint.

Deformation of a layered half-space due to a very long tensile fault

Indian Academy of Sciences (India)

The problem of the coseismic deformation of an earth model consisting of an elastic layer of uniform thickness overlying an elastic half-space due to a very long tensile fault in the layer is solved analytically. Integral expressions for the surface displacements are obtained for a vertical tensile fault and a horizontal tensile fault.

Long-Term MRI Findings in Operated Rotator Cuff Tear

International Nuclear Information System (INIS)

Kyroelae, K.; Niemitukia, L.; Jaroma, H.; Vaeaetaeinen, U.

2004-01-01

Purpose: To describe magnetic resonance imaging (MRI) findings at long-term follow-up after rotator cuff (RC) tear using standard MRI sequences without fat saturation. Material and Methods: Twenty-eight patients aged 55.8±7.6 underwent MRI examination 4.6±2.1 years after surgery for RC tear. Standard sequences in oblique coronal, oblique sagittal, and axial planes were obtained. The RC, including re-tears and tendon degeneration, was independently evaluated by two observers. Thickness of the supraspinatus tendon and narrowing of the subacromial space were measured. The clinical outcome was evaluated with the Constant score and compared with the MRI findings. Results: The RC tear was traumatic in 18 (64%) patients and degenerative in 10 (36%). At follow-up, 11 (39%) had normal RC tendons with good clinical outcome. Four (14%) patients had painful tendinosis without RC tear. A full-thickness RC tear was found in 7 (25%) patients and a partial tear in 6 (21%). In one patient with a full-thickness tear, and in two with partial tear, tendinosis was found in another of the RC tendons. The subacromial space was narrowed in 13 (46%) of the patients. A narrowing of the subacromial space correlated with re-tear (P<0.05). Conclusions: The RC may be evaluated with standard MRI sequences without fat saturation at long-term follow-up. A normal appearance of the RC is correlated with good clinical outcome, while re-tear and tendinosis are associated with pain

Diagnostic performance of susceptibility-weighted magnetic resonance imaging for the assessment of sub-coracoacromial spurs causing subacromial impingement syndrome.

Science.gov (United States)

Nörenberg, Dominik; Armbruster, Marco; Bender, Yi-Na; Walter, Thula; Ebersberger, Hans U; Diederichs, Gerd; Hamm, Bernd; Ockert, Ben; Makowski, Marcus R

2017-03-01

To evaluate the potential of susceptibility-weighted-magnetic-resonance-imaging (SWMR) for the detection of sub-coracoacromial spurs in patients with clinically suspected subacromial impingement syndrome (SAIS), compared to standard MR-sequences and radiographs. Forty-four patients with suspected SAIS were included. All patients underwent radiography, standard MRI of the shoulder and SWMR. Radiograph-based identification of sub-coracoacromial spurs served as goldstandard. Radiographs identified twenty-three spurs in twenty-three patients. Twenty-one patients without spur formation served as reference group. Detection rate, sensitivity/specificity and interobserver-agreements were calculated. Linear regression was applied to determine the relationship between size measurements on radiographs and MRI. Detection rates for spurs on standard MRI and SWMR were 47.8 % and 91.3 % compared to radiography (pformation in patients with SAIS and is superior to standard MR-sequences using radiography as goldstandard. • SWMR has the potential to reliably identify sub-coracoacromial spurs without radiation exposure. • SWMR provides comparable detection rates to conventional radiography for sub-coracoacromial spur formation. • SWMR yields higher detection rates compared to standard-MR regarding sub-coracoacromial spur formation. • SWMR can be implemented in routine shoulder MRI protocols.

Medical Implications of Space Radiation Exposure Due to Low-Altitude Polar Orbits.

Science.gov (United States)

Chancellor, Jeffery C; Auñon-Chancellor, Serena M; Charles, John

2018-01-01

Space radiation research has progressed rapidly in recent years, but there remain large uncertainties in predicting and extrapolating biological responses to humans. Exposure to cosmic radiation and solar particle events (SPEs) may pose a critical health risk to future spaceflight crews and can have a serious impact on all biomedical aspects of space exploration. The relatively minimal shielding of the cancelled 1960s Manned Orbiting Laboratory (MOL) program's space vehicle and the high inclination polar orbits would have left the crew susceptible to high exposures of cosmic radiation and high dose-rate SPEs that are mostly unpredictable in frequency and intensity. In this study, we have modeled the nominal and off-nominal radiation environment that a MOL-like spacecraft vehicle would be exposed to during a 30-d mission using high performance, multicore computers. Projected doses from a historically large SPE (e.g., the August 1972 solar event) have been analyzed in the context of the MOL orbit profile, providing an opportunity to study its impact to crew health and subsequent contingencies. It is reasonable to presume that future commercial, government, and military spaceflight missions in low-Earth orbit (LEO) will have vehicles with similar shielding and orbital profiles. Studying the impact of cosmic radiation to the mission's operational integrity and the health of MOL crewmembers provides an excellent surrogate and case-study for future commercial and military spaceflight missions.Chancellor JC, Auñon-Chancellor SM, Charles J. Medical implications of space radiation exposure due to low-altitude polar orbits. Aerosp Med Hum Perform. 2018; 89(1):3-8.

Quantifying the daily economic impact of extreme space weather due to failure in electricity transmission infrastructure

Science.gov (United States)

Oughton, Edward J.; Skelton, Andrew; Horne, Richard B.; Thomson, Alan W. P.; Gaunt, Charles T.

2017-01-01

Extreme space weather due to coronal mass ejections has the potential to cause considerable disruption to the global economy by damaging the transformers required to operate electricity transmission infrastructure. However, expert opinion is split between the potential outcome being one of a temporary regional blackout and of a more prolonged event. The temporary blackout scenario proposed by some is expected to last the length of the disturbance, with normal operations resuming after a couple of days. On the other hand, others have predicted widespread equipment damage with blackout scenarios lasting months. In this paper we explore the potential costs associated with failure in the electricity transmission infrastructure in the U.S. due to extreme space weather, focusing on daily economic loss. This provides insight into the direct and indirect economic consequences of how an extreme space weather event may affect domestic production, as well as other nations, via supply chain linkages. By exploring the sensitivity of the blackout zone, we show that on average the direct economic cost incurred from disruption to electricity represents only 49% of the total potential macroeconomic cost. Therefore, if indirect supply chain costs are not considered when undertaking cost-benefit analysis of space weather forecasting and mitigation investment, the total potential macroeconomic cost is not correctly represented. The paper contributes to our understanding of the economic impact of space weather, as well as making a number of key methodological contributions relevant for future work. Further economic impact assessment of this threat must consider multiday, multiregional events.

Enhanced ionic conductivity in composite materials due to interfacial space charge layers

International Nuclear Information System (INIS)

Dudney, N.J.

1985-01-01

The ionic conductivity of a number of salts (e.g., β-AgI, LiI, CuCl, HgI 2 , etc.) can be enhanced by one to three orders of magnitude with the addition of fine particles of an insoluble and nonconducting material such as Al 2 O 3 or SiO 2 . Typically the conductivity increases with addition of the inert particles and reaches a peak at 10-40 vol % of the particles. The mechanism responsible for the enhanced conductivity of the composite is not understood at this time. Some claim that this effect is due to an increased concentration of charge carriers in a diffuse space charge layer near the charged surface of the particle. The goal of the present study is to test this proposed mechanism by calculating the maximum space charge layer effect and then using this result to estimate the conductivity of a composite with a random distribution of Al 2 O 3 particles. Also, the conductivity of composite systems has been investigated assuming an ordered distribution of particles which are surrounded by a high conductivity layer

2-D Deformation analysis of a half-space due to a long dip-slip fault ...

Indian Academy of Sciences (India)

R. Narasimhan (Krishtel eMaging) 1461 1996 Oct 15 13:05:22

tic deformation in a uniform half-space due to long faults has been attempted by a number of researchers. Singh and Rani (1996) presented step- by-step progress made in the direction of crustal deformation modeling associated with strike-slip and dip-slip faulting in the earth. Cohen (1996) gave convenient formulas for ...

Methods of approaching decoherence in the flavor sector due to space-time foam

Science.gov (United States)

Mavromatos, N. E.; Sarkar, Sarben

2006-08-01

In the first part of this work we discuss possible effects of stochastic space-time foam configurations of quantum gravity on the propagation of “flavored” (Klein-Gordon and Dirac) neutral particles, such as neutral mesons and neutrinos. The formalism is not the usually assumed Lindblad one, but it is based on random averages of quantum fluctuations of space-time metrics over which the propagation of the matter particles is considered. We arrive at expressions for the respective oscillation probabilities between flavors which are quite distinct from the ones pertaining to Lindblad-type decoherence, including in addition to the (expected) Gaussian decay with time, a modification to oscillation behavior, as well as a power-law cutoff of the time-profile of the respective probability. In the second part we consider space-time foam configurations of quantum-fluctuating charged-black holes as a way of generating (parts of) neutrino mass differences, mimicking appropriately the celebrated Mikheyev-Smirnov-Wolfenstein (MSW) effects of neutrinos in stochastically fluctuating random media. We pay particular attention to disentangling genuine quantum-gravity effects from ordinary effects due to the propagation of a neutrino through ordinary matter. Our results are of interest to precision tests of quantum-gravity models using neutrinos as probes.

Inter- and intrarater reliability of goniometry and hand held dynamometry for patients with subacromial impingement syndrome.

Science.gov (United States)

Fieseler, Georg; Laudner, Kevin G; Irlenbusch, Lars; Meyer, Henrike; Schulze, Stephan; Delank, Karl-Stefan; Hermassi, Souhail; Bartels, Thomas; Schwesig, René

2017-12-01

The purpose of this study was to examine the intra- and interrater reliability of measuring shoulder range of motion (ROM) and strength among patients diagnosed with subacromial impingement syndrome (SAIS). Twenty-five patients (14 female patients; mean age, 60.4± 7.84 years) diagnosed with SAIS were assessed to determine the intrarater reliability for glenohumeral ROM. Twenty-five patients (16 female patients; mean age, 60.4± 7.80 years) and 76 asymptomatic volunteers (52 female volunteers; mean age, 29.4± 14.1 years) were assessed for interrater reliability. Dependent variables were active shoulder ROM and isometric strength. Intrarater reliability was fair-to-excellent for the SAIS patients (intraclass correlation coefficient [ICC], 0.52-0.97; standard error of measurement [SEM], 4.4°-9.9° N; coefficient of variation [CV], 7.1%-44.9%). Based on the ICC, 11 of 12 parameters (92%) displayed an excellent reliability (ICC> 0.75). The interrater reliability showed fair-to-excellent results (SAIS patients: ICC, 0.13-0.98; SEM, 2.3°-8.8°; CV, 3.6%-37.0%; controls: ICC, 0.11-0.96; SEM, 3.0°-35.4°; CV, 5.6%-26.4%). In accordance with the intrarater reliability, glenohumeral adduction ROM was the only parameter with an ICC below 0.75 for both samples. Painful shoulder ROM in the SAIS patients showed no influence on the quality of reliability for measurement. Therefore, these protocols should be considered reliable assessment techniques in the prevention, diagnosis, and treatment of painful shoulder conditions such as SAIS.

Gain reduction due to space charge at high counting rates in multiwire proportional chambers

International Nuclear Information System (INIS)

Smith, G.C.; Mathieson, E.

1986-10-01

Measurements with a small MWPC of gas gain reduction, due to ion space charge at high counting rates, have been compared with theoretical predictions. The quantity ln(q/q 0 )/(q/q 0 ), where (q/q 0 ) is the relative reduced avalanche charge, has been found to be closely proportional to count rate, as predicted. The constant of proportionality is in good agreement with calculations made with a modified version of the original, simplified theory

Cumulative occupational shoulder exposures and surgery for subacromial impingement syndrome: a nationwide Danish cohort study.

Science.gov (United States)

Dalbøge, Annett; Frost, Poul; Andersen, Johan Hviid; Svendsen, Susanne Wulff

2014-11-01

The primary aim was to examine exposure-response relationships between cumulative occupational shoulder exposures and surgery for subacromial impingement syndrome (SIS), and to compare sex-specific exposure-response relationships. The secondary aim was to examine the time window of relevant exposures. We conducted a nationwide register study of all persons born in Denmark (1933-1977), who had at least 5 years of full-time employment. In the follow-up period (2003-2008), we identified first-time events of surgery for SIS. Cumulative exposure estimates for a 10-year exposure time window with a 1-year lag time were obtained by linking occupational codes with a job exposure matrix. The exposure estimates were expressed as, for example, arm-elevation-years in accordance with the pack-year concept of tobacco consumption. We used a multivariable logistic regression technique equivalent to discrete survival analysis. The adjusted OR (ORadj) increased to a maximum of 2.1 for arm-elevation-years, repetition-years and force-years, and to 1.5 for hand-arm-vibration-years. Sex-specific exposure-response relationships were similar for men and women, when assessed using a relative risk scale. The ORadj increased gradually with the number of years contributing to the cumulative exposure estimates. The excess fraction was 24%. Cumulative occupational shoulder exposures carried an increase in risk of surgery for SIS with similar exposure-response curves for men and women. The risk of surgery for SIS increased gradually, when the period of exposure assessment was extended. In the general working population, a substantial fraction of all first-time operations for SIS could be related to occupational exposures. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

Comparison of continuous interscalene block and subacromial infusion of local anesthetic for postoperative analgesia after open shoulder surgery.

Science.gov (United States)

Baskan, Semih; Cankaya, Deniz; Unal, Hidayet; Yoldas, Burak; Taspinar, Vildan; Deveci, Alper; Tabak, Yalcin; Baydar, Mustafa

2017-01-01

This study compared the efficacy of continuous interscalene block (CISB) and subacromial infusion of local anesthetic (CSIA) for postoperative analgesia after open shoulder surgery. This randomized, prospective, double-blinded, single-center study included 40 adult patients undergoing open shoulder surgery. All patients received a standardized general anesthetic. The patients were separated into group CISB and group CSIA. A loading dose of 40 mL 0.25% bupivacaine was administered and patient-controlled analgesia was applied by catheter with 0.1% bupivacaine 5 mL/h throughout 24 h basal infusion, 2 mL bolus dose, and 20 min knocked time in both groups postoperatively. Visual analog scale (VAS) scores, additional analgesia need, local anesthetic consumption, complications, and side effects were recorded during the first 24 h postoperatively. The range of motion (ROM) score was recorded preoperatively and in the first and third weeks postoperatively. A statistically significant difference was determined between the groups in respect of consumption of local anesthetic, VAS scores, additional analgesia consumption, complications, and side effects, with lower values recorded in the CISB group. There were no significant differences in ROM scoring in the preoperative and postoperative third week between the two groups but there were significant differences in ROM scoring in the postoperative first week, with higher ROM scoring values in the group CISB patients. The results of this study have shown that continuous interscalene infusion of bupivacaine is an effective and safe method of postoperative analgesia after open shoulder surgery.

Doses due to extra-vehicular activity on space stations

Energy Technology Data Exchange (ETDEWEB)

Deme, S.; Apathy, I.; Feher, I. [KFKI Atomic Energy Research Institute, Budapest (Hungary); Akatov, Y.; Arkhanguelski, V. [Institute of Biomedical Problems, State Scientific Center, Moscow (Russian Federation); Reitz, G. [DLR Institute of Aerospace Medicine, Cologne, Linder Hohe (Germany)

2006-07-01

One of the many risks of long duration space flight is the dose from cosmic radiation, especially during periods of intensive solar activity. At such times, particularly during extra-vehicular activity (E.V.A.), when the astronauts are not protected by the wall of the spacecraft, cosmic radiation is a potentially serious health threat. Accurate dose measurement becomes increasingly important during the assembly of large space objects. Passive integrating detector systems such as thermoluminescent dosimeters (TLDs) are commonly used for dosimetric mapping and personal dosimetry on space vehicles. K.F.K.I. Atomic Energy Research Institute has developed and manufactured a series of thermoluminescent dosimeter systems, called Pille, for measuring cosmic radiation doses in the 3 {mu}Gy to 10 Gy range, consisting of a set of CaSO{sub 4}:Dy bulb dosimeters and a small, compact, TLD reader suitable for on-board evaluation of the dosimeters. Such a system offers a solution for E.V.A. dosimetry as well. By means of such a system, highly accurate measurements were carried out on board the Salyut-6, -7 and Mir Space Stations, on the Space Shuttle, and most recently on several segments of the International Space Station (I.S.S.). The Pille system was used to make the first measurements of the radiation exposure of cosmonauts during E.V.A.. Such E.V.A. measurements were carried out twice (on June 12 and 16, 1987) by Y. Romanenko, the commander of the second crew of Mir. During the E.V.A. one of the dosimeters was fixed in a pocket on the outer surface of the left leg of his space-suit; a second dosimeter was located inside the station for reference measurements. The advanced TLD system Pille 96 was used during the Nasa-4 (1997) mission to monitor the cosmic radiation dose inside the Mir Space Station and to measure the exposure of two of the astronauts during their E.V.A. activities. The extra doses of two E.V.A. during the Euromir 95 and one E.V.A. during the Nasa4 experiment

Doses due to extra-vehicular activity on space stations

International Nuclear Information System (INIS)

Deme, S.; Apathy, I.; Feher, I.; Akatov, Y.; Arkhanguelski, V.; Reitz, G.

2006-01-01

One of the many risks of long duration space flight is the dose from cosmic radiation, especially during periods of intensive solar activity. At such times, particularly during extra-vehicular activity (E.V.A.), when the astronauts are not protected by the wall of the spacecraft, cosmic radiation is a potentially serious health threat. Accurate dose measurement becomes increasingly important during the assembly of large space objects. Passive integrating detector systems such as thermoluminescent dosimeters (TLDs) are commonly used for dosimetric mapping and personal dosimetry on space vehicles. K.F.K.I. Atomic Energy Research Institute has developed and manufactured a series of thermoluminescent dosimeter systems, called Pille, for measuring cosmic radiation doses in the 3 μGy to 10 Gy range, consisting of a set of CaSO 4 :Dy bulb dosimeters and a small, compact, TLD reader suitable for on-board evaluation of the dosimeters. Such a system offers a solution for E.V.A. dosimetry as well. By means of such a system, highly accurate measurements were carried out on board the Salyut-6, -7 and Mir Space Stations, on the Space Shuttle, and most recently on several segments of the International Space Station (I.S.S.). The Pille system was used to make the first measurements of the radiation exposure of cosmonauts during E.V.A.. Such E.V.A. measurements were carried out twice (on June 12 and 16, 1987) by Y. Romanenko, the commander of the second crew of Mir. During the E.V.A. one of the dosimeters was fixed in a pocket on the outer surface of the left leg of his space-suit; a second dosimeter was located inside the station for reference measurements. The advanced TLD system Pille 96 was used during the Nasa-4 (1997) mission to monitor the cosmic radiation dose inside the Mir Space Station and to measure the exposure of two of the astronauts during their E.V.A. activities. The extra doses of two E.V.A. during the Euromir 95 and one E.V.A. during the Nasa4 experiment were

Experimental measurements of the eddy current signal due to a flawed, conducting half space

International Nuclear Information System (INIS)

Long, S.A.; Toomsawasdi, S.; Zaman, A.J.M.

1984-01-01

This chapter reports on an experimental investigation in which the change in impedance of a practical multi-turn eddy current coil near a conducting half space is measured as a function of the conductivity and the lift-off distance. The results are compared in a qualitative fashion with the analytical results for a single-turn coil. Measurements are also made of the change in impedance due to a small void in the conducting half space as a function of both its depth and radial position. The results indicate that, at least in a qualitative fashion, the precisely derived analytical solutions adequately predict the general behavior of the change in complex impedance of an eddy current coil above a conducting ground plane as a function of lift-off distance. It is determined that the effect of a sub-surface void on the change in inductance of the test coil correlates well with theoretical calculations

Shoulder strengthening exercises adapted to specific shoulder pathologies can be selected using new simulation techniques: a pilot study.

Science.gov (United States)

Charbonnier, Caecilia; Lädermann, Alexandre; Kevelham, Bart; Chagué, Sylvain; Hoffmeyer, Pierre; Holzer, Nicolas

2018-02-01

Shoulder strength training exercises represent a major component of rehabilitation protocols designed for conservative or postsurgical management of shoulder pathologies. Numerous methods are described for exercising each shoulder muscle or muscle group. Limited information is available to assess potential deleterious effects of individual methods with respect to specific shoulder pathologies. Thus, the goal of this pilot study was to use a patient-specific 3D measurement technique coupling medical imaging and optical motion capture for evaluation of a set of shoulder strength training exercises regarding glenohumeral, labral and subacromial compression, as well as elongation of the rotator cuff muscles. One volunteer underwent magnetic resonance imaging (MRI) and motion capture of the shoulder. Motion data from the volunteer were recorded during three passive rehabilitation exercises and twenty-nine strengthening exercises targeting eleven of the most frequently trained shoulder muscles or muscle groups and using four different techniques when available. For each exercise, glenohumeral and labral compression, subacromial space height and rotator cuff muscles elongation were measured on the entire range of motion. Significant differences in glenohumeral, subacromial and labral compressions were observed between sets of exercises targeting individual shoulder muscles. Muscle lengths computed by simulation compared to MRI measurements showed differences of 0-5%. This study represents the first screening of shoulder strengthening exercises to identify potential deleterious effects on the shoulder joint. Motion capture combined with medical imaging allows for reliable assessment of glenohumeral, labral and subacromial compression, as well as muscle-tendon elongation during shoulder strength training exercises.

Rilonacept in the treatment of subacromial bursitis: A randomized, non-inferiority, unblinded study versus triamcinolone acetonide.

Science.gov (United States)

Carroll, Matthew B; Motley, Spencer A; Wohlford, Susanna; Ramsey, Bryan C

2015-12-01

Subacromial bursitis is caused by inflammation of the bursa that separates the superior surface of the supraspinatus tendon from the overlying coraco-acromial ligament and acromion. While multiple cytokines are implicated, interleukin-1 beta appears to play a prominent role. Rilonacept, an interleukin-1 trap, may be an alternative to corticosteroid injection for the management of this condition. This single center, randomized, non-inferiority, unblinded study recruited 33 subjects over 9 months. Twenty subjects received 160mg intrabursal injection of rilonacept and 13 received a 6mL mixture of lidocaine, bupivacaine, and 80mg triamcinolone acetonide. QuickDASH, subject reported pain, and adverse events were recorded at time of injection, 2 days later, 2 weeks later, and 4 weeks later. Primary outcome was improvement in QuickDASH 4 weeks post-injection. Secondary outcomes were improvement in subject reported pain and occurrence of adverse events at 4 weeks. Both study groups were equally matched for age, gender, ethnicity, and site of bursa injection. Both medications demonstrated a statistically significant improvement in QuickDASH 4 weeks post-injection, but triamcinolone acetonide injection offered greater improvement (P=0.004). Both medications demonstrated improvement in subject reported pain but between group comparison at 4 weeks showed that triamcinolone was superior (P=0.044). No statistically significant differences in adverse events were noted between groups, but subjects who received rilonacept experienced more episodes of diarrhea and headache. While improvement in QuickDASH and pain was noted with a single intrabursal injection of rilonacept at 4 weeks, injection with triamcinolone acetonide was more efficacious. This trial was registered with www.clinicaltrials.gov (NCT01830699). Copyright © 2015 Société française de rhumatologie. Published by Elsevier SAS. All rights reserved.

Emittance growth due to space charge compensation and beam intensity instabilities in negative ion beams

Directory of Open Access Journals (Sweden)

C. A. Valerio-Lizarraga

2018-03-01

Full Text Available The need to extract the maximum beam intensity with low transversal emittance often comes with the drawback of operating the ion source to limits where beam current instabilities arise, such fluctuations can change the beam properties producing a mismatch in the following sections of the machine. The space charge compensation (SCC generated by the beam particles colliding with the residual gas reaches a steady state after a build-up time. This paper shows how once in the steady state, the beam ends with a transversal emittance value bigger than the case without compensation. In addition, we study how the beam intensity variation can disturb the SCC dynamics and its impact on the beam properties. The results presented in this work come from 3-D simulations using tracking codes taking into account the secondary ions to estimate the degree of the emittance growth due to space charge and SCC.

The active abduction view: A new maneuvre in the diagnosis of rotator cuff tears

International Nuclear Information System (INIS)

Bloom, R.A.

1991-01-01

A new projection is described, the active abduction view of the shoulder, where in many patients with a comlete rotator cuff tear the humeral head is closely apposed to the acromion, obliterating the subacromial space. In such a situation,the medial portion of the torn rotator cuff retracts during active abduction, allowing approximation of the two bones. (orig./GDG)

The impact of subacromial impingement syndrome on muscle activity patterns of the shoulder complex: a systematic review of electromyographic studies

Directory of Open Access Journals (Sweden)

Smith Toby O

2010-03-01

Full Text Available Abstract Background Subacromial impingement syndrome (SIS is a commonly reported cause of shoulder pain. The purpose of this study was to systematically review the literature to examine whether a difference in electromyographic (EMG activity of the shoulder complex exists between people with SIS and healthy controls. Methods Medline, CINAHL, AMED, EMBASE, and grey literature databases were searched from their inception to November 2008. Inclusion, data extraction and trial quality were assessed in duplicate. Results Nine studies documented in eleven papers, eight comparing EMG intensity and three comparing EMG onset timing, representing 141 people with SIS and 138 controls were included. Between one and five studies investigated each muscle totalling between 20 and 182 participants. The two highest quality studies of five report a significant increase in EMG intensity in upper trapezius during scaption in subjects with SIS. There was evidence from 2 studies of a delayed activation of lower trapezius in patients with SIS. There was otherwise no evidence of a consistent difference in EMG activity between the shoulders of subjects with painful SIS and healthy controls. Conclusions A difference may exist in EMG activity within some muscles, in particular upper and lower trapezius, between people with SIS and healthy controls. These muscles may be targets for clinical interventions aiding rehabilitation for people with SIS. These differences should be investigated in a larger, high quality survey and the effects of therapeutically targeting these muscles in a randomised controlled trial.

Recognizing Genius loci in Designing Children’s Spaces, Due to the Phenomenological Ideas of Norberg-Schulz

Directory of Open Access Journals (Sweden)

R. Nikravesh

2015-02-01

Full Text Available Christian Norberg- Schulz explained his ideas about the phenomenology of architecture, indebted to Martin Heidegger’s opinionsand believed that one of the main strategies for identification of the place is creating meaningful environments. Schulz can be considered as one of theorists who created new ideas in architecture after Gideon and believed that considering to other scientific fields is necessary to achieve the true nature of architecture. In fact the phenomenological approach can be understood as an interdisciplinary species that explain about existence and cognition in other fields like designing different spaces. Accordingly emphasizing on interdisciplinary trends and studies can help to identify and understand the multiple issues and by studying the different approaches, the scientific expansion of the problem’s aspects will be possible. This article with an Interdisciplinary and phenomenological point of view and due to the main ideas of Norberg- Schulz, analyses the concept of place and space and also the importance of concerning about children’s spaces. So at first a brief knowledge about the book of Norberg-Schulz in phenomenological approach will be achieved and by studying the opinions of other theorists, some results about the importance of considering the concept of genius loci in architectural spaces will be achieved. In this document, by using the descriptive- analytical method and by means of data collection, including studies, library and documentation, the relating concepts and strategies of improving the quality of children’s spaces, is analyzed. According to this article, It could be said that meanings, culture and history of a place, include identifying factors that cause creating memories and a sense of belonging to the place for individuals and thus the formation of their personality in childhood. So one of the main tasks of modern architects is creating a sense of space in children’s spaces and reminding

Preconditioning of Interplanetary Space Due to Transient CME Disturbances

International Nuclear Information System (INIS)

Temmer, M.; Reiss, M. A.; Hofmeister, S. J.; Veronig, A. M.; Nikolic, L.

2017-01-01

Interplanetary space is characteristically structured mainly by high-speed solar wind streams emanating from coronal holes and transient disturbances such as coronal mass ejections (CMEs). While high-speed solar wind streams pose a continuous outflow, CMEs abruptly disrupt the rather steady structure, causing large deviations from the quiet solar wind conditions. For the first time, we give a quantification of the duration of disturbed conditions (preconditioning) for interplanetary space caused by CMEs. To this aim, we investigate the plasma speed component of the solar wind and the impact of in situ detected interplanetary CMEs (ICMEs), compared to different background solar wind models (ESWF, WSA, persistence model) for the time range 2011–2015. We quantify in terms of standard error measures the deviations between modeled background solar wind speed and observed solar wind speed. Using the mean absolute error, we obtain an average deviation for quiet solar activity within a range of 75.1–83.1 km s −1 . Compared to this baseline level, periods within the ICME interval showed an increase of 18%–32% above the expected background, and the period of two days after the ICME displayed an increase of 9%–24%. We obtain a total duration of enhanced deviations over about three and up to six days after the ICME start, which is much longer than the average duration of an ICME disturbance itself (∼1.3 days), concluding that interplanetary space needs ∼2–5 days to recover from the impact of ICMEs. The obtained results have strong implications for studying CME propagation behavior and also for space weather forecasting.

Preconditioning of Interplanetary Space Due to Transient CME Disturbances

Energy Technology Data Exchange (ETDEWEB)

Temmer, M.; Reiss, M. A.; Hofmeister, S. J.; Veronig, A. M. [Institute of Physics, University of Graz, Universitätsplatz 5/II, A-8010 Graz (Austria); Nikolic, L., E-mail: manuela.temmer@uni-graz.at [Canadian Hazards Information Service, Natural Resources Canada, 2617 Anderson Road, Ottawa, Ontario K1A 0Y3 (Canada)

2017-02-01

Interplanetary space is characteristically structured mainly by high-speed solar wind streams emanating from coronal holes and transient disturbances such as coronal mass ejections (CMEs). While high-speed solar wind streams pose a continuous outflow, CMEs abruptly disrupt the rather steady structure, causing large deviations from the quiet solar wind conditions. For the first time, we give a quantification of the duration of disturbed conditions (preconditioning) for interplanetary space caused by CMEs. To this aim, we investigate the plasma speed component of the solar wind and the impact of in situ detected interplanetary CMEs (ICMEs), compared to different background solar wind models (ESWF, WSA, persistence model) for the time range 2011–2015. We quantify in terms of standard error measures the deviations between modeled background solar wind speed and observed solar wind speed. Using the mean absolute error, we obtain an average deviation for quiet solar activity within a range of 75.1–83.1 km s{sup −1}. Compared to this baseline level, periods within the ICME interval showed an increase of 18%–32% above the expected background, and the period of two days after the ICME displayed an increase of 9%–24%. We obtain a total duration of enhanced deviations over about three and up to six days after the ICME start, which is much longer than the average duration of an ICME disturbance itself (∼1.3 days), concluding that interplanetary space needs ∼2–5 days to recover from the impact of ICMEs. The obtained results have strong implications for studying CME propagation behavior and also for space weather forecasting.

Shoulder impingement syndrome : evaluation of the causes with MRI

Energy Technology Data Exchange (ETDEWEB)

Choi, Yong Ho; Song, In Sup; Chung, Hun Young; Yoon, Sang Jin; Kim, Yang Soo; Shim, Hyung Jin; Choi, Young Hee; Lee, Jong Beum; Lee, Yong Chul; Kim, Kun Sang [Chungang Univ. College of Medicine, Seoul (Korea, Republic of); Choi, Yun Sun [Eulji Hospital, College of Medicine, Seoul (Korea, Republic of)

1999-12-01

Various mechanical causes which induce shoulder impingement syndrome have been identified with the help of MRI. The aim of this study is to evaluate the incidence of such causes. A total of 54 patients with clinically confirmed shoulder impingement syndrome and a normal control group(n=20) without symptoms were included. We evaluated the incidence of hook shaped acromion, low lying acromion, downward slope of the acromion, subacromial spur, acromioclavicular joint hypertrophy, coracoacromial ligament hypertrophy, high cuff muscle bulk, and os acromiale. Among the 54 patients, the following conditions were present: acromioclavicular joint hypertrophy(n=36), coracoacromial ligament hypertrophy(n=20), subacromial spur(n=18), downward sloping of the acromion(n=16), hook shaped acromion(n=11), relatively high cuff muscle bulk(n=6), low lying acromion relative to the clavicle(n=3), and os acromiale(n=1). In the normal control group there were nine cases of acromioclavicular joint hypertrophy, nine of coracoacromial ligament hypertrophy, nine of downward sloping acromion, and three of low lying acromion, but hook shaped acromion, high cuff muscle bulk, and os acromiale were not found. Among 54 patients, the syndrome was due to five simultancous causes in one patient, four causes in two, three causes in 12, two causes in 22, and one cause in 17. Hook shaped acromion and subacromial spur are the statistically significant causes of shoulder impingement syndrome. In 69% of patients, the condition was due to more than one cause.

Shoulder impingement syndrome : evaluation of the causes with MRI

International Nuclear Information System (INIS)

Choi, Yong Ho; Song, In Sup; Chung, Hun Young; Yoon, Sang Jin; Kim, Yang Soo; Shim, Hyung Jin; Choi, Young Hee; Lee, Jong Beum; Lee, Yong Chul; Kim, Kun Sang; Choi, Yun Sun

1999-01-01

Various mechanical causes which induce shoulder impingement syndrome have been identified with the help of MRI. The aim of this study is to evaluate the incidence of such causes. A total of 54 patients with clinically confirmed shoulder impingement syndrome and a normal control group(n=20) without symptoms were included. We evaluated the incidence of hook shaped acromion, low lying acromion, downward slope of the acromion, subacromial spur, acromioclavicular joint hypertrophy, coracoacromial ligament hypertrophy, high cuff muscle bulk, and os acromiale. Among the 54 patients, the following conditions were present: acromioclavicular joint hypertrophy(n=36), coracoacromial ligament hypertrophy(n=20), subacromial spur(n=18), downward sloping of the acromion(n=16), hook shaped acromion(n=11), relatively high cuff muscle bulk(n=6), low lying acromion relative to the clavicle(n=3), and os acromiale(n=1). In the normal control group there were nine cases of acromioclavicular joint hypertrophy, nine of coracoacromial ligament hypertrophy, nine of downward sloping acromion, and three of low lying acromion, but hook shaped acromion, high cuff muscle bulk, and os acromiale were not found. Among 54 patients, the syndrome was due to five simultancous causes in one patient, four causes in two, three causes in 12, two causes in 22, and one cause in 17. Hook shaped acromion and subacromial spur are the statistically significant causes of shoulder impingement syndrome. In 69% of patients, the condition was due to more than one cause

Dosimetric variation due to CT inter-slice spacing in four-dimensional carbon beam lung therapy

International Nuclear Information System (INIS)

Kumagai, Motoki; Mori, Shinichiro; Kandatsu, Susumu; Baba, Masayuki; Sharp, Gregory C; Asakura, Hiroshi; Endo, Masahiro

2009-01-01

When CT data with thick slice thickness are used in treatment planning, geometrical uncertainty may induce dosimetric errors. We evaluated carbon ion dose variations due to different CT slice thicknesses using a four-dimensional (4D) carbon ion beam dose calculation, and compared results between ungated and gated respiratory strategies. Seven lung patients were scanned in 4D mode with a 0.5 mm slice thickness using a 256-multi-slice CT scanner. CT images were averaged with various numbers of images to simulate reconstructed images with various slice thicknesses (0.5-5.0 mm). Two scenarios were studied (respiratory-ungated and -gated strategies). Range compensators were designed for each of the CT volumes with coarse inter-slice spacing to cover the internal target volume (ITV), as defined from 4DCT. Carbon ion dose distribution was computed for each resulting ITV on the 0.5 mm slice 4DCT data. The accumulated dose distribution was then calculated using deformable registration for 4D dose assessment. The magnitude of over- and under-dosage was found to be larger with the use of range compensators designed with a coarser inter-slice spacing than those obtained with a 0.5 mm slice thickness. Although no under-dosage was observed within the clinical target volume (CTV) region, D95 remained at over 97% of the prescribed dose for the ungated strategy and 95% for the gated strategy for all slice thicknesses. An inter-slice spacing of less than 3 mm may be able to minimize dose variation between the ungated and gated strategies. Although volumes with increased inter-slice spacing may reduce geometrical accuracy at a certain respiratory phase, this does not significantly affect delivery of the accumulated dose to the target during the treatment course.

The effect of additional dead space on respiratory exchange ratio and carbon dioxide production due to training.

Science.gov (United States)

Smolka, Lukasz; Borkowski, Jacek; Zaton, Marek

2014-01-01

The purpose of the study was to investigate the effects of implementing additional respiratory dead space during cycloergometry-based aerobic training. The primary outcome measures were respiratory exchange ratio (RER) and carbon dioxide production (VCO2). Two groups of young healthy males: Experimental (Exp, n = 15) and Control (Con, n = 15), participated in this study. The training consisted of 12 sessions, performed twice a week for 6 weeks. A single training session consisted of continuous, constant-rate exercise on a cycle ergometer at 60% of VO2max which was maintained for 30 minutes. Subjects in Exp group were breathing through additional respiratory dead space (1200ml), while subjects in Con group were breathing without additional dead space. Pre-test and two post-training incremental exercise tests were performed for the detection of gas exchange variables. In all training sessions, pCO2 was higher and blood pH was lower in the Exp group (p exchange ratio and carbon dioxide production.In all training sessions, respiratory acidosis was gained by experimental group only.No significant difference in RER and VCO2 between experimental and control group due to the trainings.The lack of difference in post-training values of RER and VCO2 between groups means absence of inhibition in glycolysis and glycogenolysis during exercise with additional dead space.

The Use of Physiotherapy among Patients with Subacromial Impingement Syndrome: Impact of Sex, Socio-Demographic and Clinical Factors

Science.gov (United States)

Christiansen, David Høyrup; Frost, Poul; Frich, Lars Henrik; Falla, Deborah; Svendsen, Susanne Wulff

2016-01-01

Background Physiotherapy with exercises is generally recommended in the treatment of patients with subacromial impingement syndrome (SIS). Objective We aimed to investigate the use of physiotherapy in patients with SIS in Danish hospital settings as part of initial non-surgical treatment and after SIS-related surgery and to evaluate to which extent sex, socio-demographic and clinical factors predict the use of physiotherapy. Methods Using national health registers, we identified 57,311 patients who had a first hospital contact with a diagnosis of ICD-10, groups M75.1–75.9, 1 July 2007 to 30 June 2011. Records of physiotherapy were extracted within 52 weeks after first contact (or until surgery), and for surgically treated patients within 26 weeks after surgery. Predictors of the use of physiotherapy after first contact and after surgery were analysed as time-to-event. Results Within 52 weeks after first contact, 43% of the patients had physiotherapy and 30% underwent surgery. Within 26 weeks after surgery, 80% had a record of physiotherapy. After first contact and after surgery, exercise was part of physiotherapy in 65% and 84% of the patients, respectively. A public hospital contact, physiotherapy before hospital contact, administrative region, female sex, a diagnosis of other or unspecified disorders (M75.8-M75.9), and surgical procedure predicted higher use of physiotherapy. Low education level predicted slightly lower use of physiotherapy after first contact, but not after surgery. Conclusion In patients with SIS in Danish hospital settings, physiotherapy was more often used after surgery than as part of initial non-surgical treatment. The use of physiotherapy was less common among men than women, whereas unequal use of physiotherapy in relation to education level was not noticeable. The use of physiotherapy with exercises in initial non-surgical treatment was relatively limited. PMID:26954692

Diagnostic performance of susceptibility-weighted magnetic resonance imaging for the assessment of sub-coracoacromial spurs causing subacromial impingement syndrome

Energy Technology Data Exchange (ETDEWEB)

Noerenberg, Dominik; Armbruster, Marco [Munich University Hospitals Campus Grosshadern, Department of Clinical Radiology, Munich (Germany); Bender, Yi-Na; Walter, Thula; Diederichs, Gerd; Hamm, Bernd [Charite - University Medicine Berlin, Department of Radiology, Berlin (Germany); Ebersberger, Hans U. [Heart Center Munich-Bogenhausen, Department of Cardiology and Intensive Care Medicine, Munich (Germany); Ockert, Ben [Munich University Hospitals Campus Grosshadern, Department of Trauma and Orthopedic Surgery, Shoulder and Elbow Service, Munich (Germany); Makowski, Marcus R. [Charite - University Medicine Berlin, Department of Radiology, Berlin (Germany); King' s College London, Division of Imaging Sciences and Biomedical Engineering, London (United Kingdom)

2017-03-15

To evaluate the potential of susceptibility-weighted-magnetic-resonance-imaging (SWMR) for the detection of sub-coracoacromial spurs in patients with clinically suspected subacromial impingement syndrome (SAIS), compared to standard MR-sequences and radiographs. Forty-four patients with suspected SAIS were included. All patients underwent radiography, standard MRI of the shoulder and SWMR. Radiograph-based identification of sub-coracoacromial spurs served as goldstandard. Radiographs identified twenty-three spurs in twenty-three patients. Twenty-one patients without spur formation served as reference group. Detection rate, sensitivity/specificity and interobserver-agreements were calculated. Linear regression was applied to determine the relationship between size measurements on radiographs and MRI. Detection rates for spurs on standard MRI and SWMR were 47.8 % and 91.3 % compared to radiography (p<0.001). SWMR demonstrated a sensitivity of 97.7 % (CI=0.92-1) and a specificity of 91.3 % (CI=0.788-1) for the identification of spurs. Standard MR-sequences achieved a sensitivity of 47.8 % (CI=0.185-0.775) and a specificity of 80.8 % (CI=0.642-0.978). Size measurements between SWMR and radiography showed a good correlation (R{sup 2}=0.75;p<0.0001), while overestimating lesion size (5.7±1.2 mm; 4.3±1.3 mm;p<0.0001). Interobserver-agreement for spurs was high on SWMR (R{sup 2}=0.74;p<0.0001), but low on standard MRI (R{sup 2}=0.24;p<0.0001). SWMR allows a reliable detection of sub-coracoacromial spur formation in patients with SAIS and is superior to standard MR-sequences using radiography as goldstandard. (orig.)

Diagnostic performance of susceptibility-weighted magnetic resonance imaging for the assessment of sub-coracoacromial spurs causing subacromial impingement syndrome

International Nuclear Information System (INIS)

Noerenberg, Dominik; Armbruster, Marco; Bender, Yi-Na; Walter, Thula; Diederichs, Gerd; Hamm, Bernd; Ebersberger, Hans U.; Ockert, Ben; Makowski, Marcus R.

2017-01-01

To evaluate the potential of susceptibility-weighted-magnetic-resonance-imaging (SWMR) for the detection of sub-coracoacromial spurs in patients with clinically suspected subacromial impingement syndrome (SAIS), compared to standard MR-sequences and radiographs. Forty-four patients with suspected SAIS were included. All patients underwent radiography, standard MRI of the shoulder and SWMR. Radiograph-based identification of sub-coracoacromial spurs served as goldstandard. Radiographs identified twenty-three spurs in twenty-three patients. Twenty-one patients without spur formation served as reference group. Detection rate, sensitivity/specificity and interobserver-agreements were calculated. Linear regression was applied to determine the relationship between size measurements on radiographs and MRI. Detection rates for spurs on standard MRI and SWMR were 47.8 % and 91.3 % compared to radiography (p<0.001). SWMR demonstrated a sensitivity of 97.7 % (CI=0.92-1) and a specificity of 91.3 % (CI=0.788-1) for the identification of spurs. Standard MR-sequences achieved a sensitivity of 47.8 % (CI=0.185-0.775) and a specificity of 80.8 % (CI=0.642-0.978). Size measurements between SWMR and radiography showed a good correlation (R 2 =0.75;p<0.0001), while overestimating lesion size (5.7±1.2 mm; 4.3±1.3 mm;p<0.0001). Interobserver-agreement for spurs was high on SWMR (R 2 =0.74;p<0.0001), but low on standard MRI (R 2 =0.24;p<0.0001). SWMR allows a reliable detection of sub-coracoacromial spur formation in patients with SAIS and is superior to standard MR-sequences using radiography as goldstandard. (orig.)

Space Threat Warning: Foundation for Space Superiority, Avoiding a Space Pearl Harbor

National Research Council Canada - National Science Library

Burke, Alan W

2006-01-01

... have stated the US must avoid a space Pearl Harbor. This concern is due to the idea that a decrease in the perceived threat to space assets after the demise of the Soviet Union coupled with a competition for space resources has resulted...

Velocity-space diffusion due to resonant wave-wave scattering of electromagnetic and electrostatic waves in a plasma

International Nuclear Information System (INIS)

Sugaya, Reija

1991-01-01

The velocity-space diffusion equation describing distortion of the velocity distribution function due to resonant wave-wave scattering of electromagnetic and electrostatic waves in an unmagnetized plasma is derived from the Vlasov-Maxwell equations by perturbation theory. The conservation laws for total energy and momentum densities of waves and particles are verified, and the time evolutions of the energy and momentum densities of particles are given in terms of the nonlinear wave-wave coupling coefficient in the kinetic wave equation. (author)

Internal- and External-Rotation Peak Toque in Little League Baseball Players With Subacromial Impingement Syndrome: Improved by Closed Kinetic Chain Shoulder Training.

Science.gov (United States)

Lee, Dong-Rour; Kim, Laurentius Jongsoon

2016-08-01

Many studies have explored closed kinetic chain (CKC) shoulder exercises (SEs) with a sling because they are safer and more effective than open-chain exercises, especially in early stages of treatment. However, the application of CKC SE in youth baseball players has rarely been attempted, although teenage baseball players also experience shoulder pain. To investigate the effects of CKC SE on the peak torque of shoulder internal rotation (IR) and external rotation (ER) in youth baseball players. Single-group pretest, posttest. Biomechanics laboratory. 23 Little League Baseball players with subacromial impingement syndrome. The CKC SE with a sling was CKC shoulder-flexion exercise, extension exercise, IR exercise, and ER exercise. This exercise regimen was conducted 2 or 3 times/wk for 8 wk. The peak torque of shoulder IR and ER was measured using an isokinetic dynamometer. Concentric shoulder rotation was performed, with 5 repetitions at an angular velocity of 60°/s and 15 at 180°/s. The IR and ER peak torque significantly increased at each angular velocity after the exercise program. In particular, the increase in IR and ER peak torque values was statistically significant at an angular velocity of 180°/s. CKC SE was effective in increasing shoulder IR and ER strength, demonstrating its potential benefits in the prevention and treatment of shoulder injury. In addition, increased IR peak torque appears to improve throwing velocity in baseball players.

Prevalence of calcific deposits within the rotator cuff tendons in adults with and without subacromial pain syndrome: clinical and radiologic analysis of 1219 patients.

Science.gov (United States)

Louwerens, Jan K G; Sierevelt, Inger N; van Hove, Ruud P; van den Bekerom, Michel P J; van Noort, Arthur

2015-10-01

Calcific tendinopathy is one of the most frequent causes of pain in the shoulder and is characterized by the presence of calcific deposits in the rotator cuff; however, calcific deposits have also been described in asymptomatic individuals. Only a few authors have reported epidemiologic data on the prevalence of calcific deposits in the rotator cuff. This study analyzed clinical and radiological data of 1219 adults with and without subacromial pain syndrome (SAPS) to assess the prevalence of calcific deposits in the rotator cuff. Multivariate analysis was used to define risk factors associated with the presence of symptomatic calcific tendinopathy. Calcific deposits were found in the rotator cuff of 57 of 734 asymptomatic patients (7.8%). Of 485 patients with SAPS, 42.5% had calcific deposits. Age between 30 and 60 years (odds ratio [OR], 8.0; 95% confidence interval [CI], 2.5-26.3; P pain (OR, 7.1; 95% CI, 5.1-9.9, P 1.5 cm in length have the highest chance of suffering from symptomatic calcific tendinopathy of the rotator cuff. The prevalence rates of 7.8% in asymptomatic patients and 42.5% in patients with SAPS provide a current view on the epidemiology of calcific deposits in the rotator cuff. Copyright © 2015 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.

Surgery for subacromial impingement syndrome in relation to intensities of occupational mechanical exposures across 10-year exposure time windows.

Science.gov (United States)

Dalbøge, Annett; Frost, Poul; Andersen, Johan Hviid; Svendsen, Susanne Wulff

2018-03-01

We aimed to identify intensities of occupational mechanical exposures (force, arm elevation and repetition) that do not entail an increased risk of surgery for subacromial impingement syndrome (SIS) even after prolonged durations of exposure. Additionally, we wanted to evaluate if exposure to hand-arm vibration (HAV) is an independent risk factor. We used data from a register-based cohort study of the entire Danish working population (n=2 374 403). During follow-up (2003-2008), 14 118 first-time events of surgery for SIS occurred. For each person, we linked register-based occupational codes (1993-2007) to a general population job exposure matrix to obtain year-by-year exposure intensities on measurement scales for force, upper arm elevation >90° and repetition and expert rated intensities of exposure to HAV. For 10-year exposure time windows, we calculated the duration of exposure at specific intensities above minimal (low, medium and high). We used a logistic regression technique equivalent to discrete survival analysis adjusting for cumulative effects of other mechanical exposures. We found indications of safe exposure intensities for repetition (median angular velocity 90° >2 min/day implied an increased risk reaching ORs of 1.7 and 1.5 after 10 years at low intensities. No associations were found for HAV. We found indications of safe exposure intensities for repetition. Any intensities of force and upper arm elevation >90° above minimal implied an increased risk across 10-year exposure time windows. No independent associations were found for HAV. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

The scapular dyskinesis test

DEFF Research Database (Denmark)

Christiansen, David Høyrup; Møller, Anders Damgaard; Vestergaard, Jesper Medom

2017-01-01

tests with which to identify scapular dyskinesis. PURPOSE OF THE STUDY: To evaluate intrarater and interrater reliability and predictive value of the Scapular Dyskinesis Test (SDT) in patients with subacromial impingement syndrome. METHODS: Forty-five patients with subacromial impingement syndrome were...

A Theory of the Podkletnov Effect based on General Relativity: Anti-Gravity Force due to the Perturbed Non-Holonomic Background of Space

Directory of Open Access Journals (Sweden)

Rabounski D.

2007-07-01

Full Text Available We consider the Podkletnov effect — the weight loss of an object located over a superconducting disc in air due to support by an alternating magnetic field. We consider this problem using the mathematical methods of General Relativity. We show via Einstein’s equations and the geodesic equations in a space perturbed by a disc undergoing oscillatory bounces orthogonal to its own plane, that there is no r ˆ ole of superconductivity; the Podkletnov effect is due to the fact that the field of the background space non-holonomity (the basic non-othogonality of time lines to the spatial section, being perturbed by such an oscillating disc produces energy and momentum flow in order to compensate the perturbation in itself. Such a momentum flow is directed above the disc in Podkletnov’s experiment, so it works like negative gravity (anti-gravity. We propose a simple mechanical system which, simulating the Podkletnov effect, is an experimental test of the whole theory. The theory allows for other “anti-gravity devices”, which simulate the Podkletnov effect without use of very costly superconductor technology. Such devices could be applied to be used as a cheap source of new energy, and could have implications to air and space travel.

Intrinsic space charge resonances and the space charge limit

International Nuclear Information System (INIS)

Parzen, G.

1990-01-01

A study has been done of the dependence of the space charge limit on the choice of ν-values using a simulation program. This study finds a strong dependence of the space charge limit on the location of the ν-values relative to the intrinsic space charge resonances, which are driven by the space charge forces due to the beam itself. Four accelerators were studied. For some of these accelerators the study suggest that the space charge limit can be increased by about a factor of 2 proper choice of the ν-values. The lower order 1/2 and 1/4 intrinsic resonances appear to be the important resonances. There is some evidence for effects due to the 1/6 and 1/8 intrinsic resonances, particularly for larger synchrotrons. 5 figs

Biomechanical Effects of Acromioplasty on Superior Capsule Reconstruction for Irreparable Supraspinatus Tendon Tears.

Science.gov (United States)

Mihata, Teruhisa; McGarry, Michelle H; Kahn, Timothy; Goldberg, Iliya; Neo, Masashi; Lee, Thay Q

2016-01-01

Acromioplasty is increasingly being performed for both reparable and irreparable rotator cuff tears. However, acromioplasty may destroy the coracoacromial arch, including the coracoacromial ligament, consequently causing a deterioration in superior stability even after superior capsule reconstruction. The purpose of this study was to investigate the effects of acromioplasty on shoulder biomechanics after superior capsule reconstruction for irreparable supraspinatus tendon tears. The hypothesis was that acromioplasty with superior capsule reconstruction would decrease the area of subacromial impingement without increasing superior translation and subacromial contact pressure. Controlled laboratory study. Seven fresh-frozen cadaveric shoulders were evaluated using a custom shoulder testing system. Glenohumeral superior translation, the location of the humeral head relative to the glenoid, and subacromial contact pressure and area were compared among 4 conditions: (1) intact shoulder, (2) irreparable supraspinatus tendon tear, (3) superior capsule reconstruction without acromioplasty, and (4) superior capsule reconstruction with acromioplasty. Superior capsule reconstruction was performed using the fascia lata. Compared with the intact shoulder, the creation of an irreparable supraspinatus tear significantly shifted the humeral head superiorly in the balanced muscle loading condition (without superior force applied) (0° of abduction: 2.8-mm superior shift [P = .0005]; 30° of abduction: 1.9-mm superior shift [P = .003]) and increased both superior translation (0° of abduction: 239% of intact [P = .04]; 30° of abduction: 199% of intact [P = .02]) and subacromial peak contact pressure (0° of abduction: 308% of intact [P = .0002]; 30° of abduction: 252% of intact [P = .001]) by applying superior force. Superior capsule reconstruction without acromioplasty significantly decreased superior translation (0° of abduction: 86% of intact [P = .02]; 30° of abduction: 75

Particle creation amplification in curved space due to thermal effects

International Nuclear Information System (INIS)

Laciana, C. E.

1997-01-01

A physical system composed by a scalar field minimally coupled to gravity and a thermal reservoir as in thermo field dynamics, all of them in curved space-time, is considered. When the formalism of thermo field dynamics is generalized to the above case, an amplification in the number of created particles is predicted

Performance degradation of space Stirling cryocoolers due to gas contamination

Science.gov (United States)

Liu, Xin-guang; Wu, Yi-nong; Yang, Shao-hua; Zhang, Xiao-ming; Lu, Guo-hua; Zhang, Li

2011-08-01

With extensive application of infrared detective techniques, Stirling cryocoolers, used as an active cooling source, have been developed vigorously in China. After the cooler's cooling performance can satisfy the mission's request, its reliability level is crucial for its application. Among all the possible failure mechanisms, gas contamination has been found to be the most notorious cause of cooler's performance degradation by failure analyses. To analyze the characteristic of gas contamination, some experiments were designed and carried out to quantitatively analyze the relationship between failure and performance. Combined with the test results and the outgassing characteristic of non-metal materials in the cryocooler, a degradation model of cooling performance was given by T(t)=T0+A[1-exp(-t/B)] under some assumptions, where t is the running time, T is the Kelvin cooling temperature, and T0, A, B are model parameters, which can be given by the least square method. Here T0 is the fitting initial cooling temperature, A is the maximum range of performance degradation, and B is the time dependent constant of degradation. But the model parameters vary when a cryocooler is running at different cooling temperature ranges, or it is treated by different cleaning process. In order to verify the applicability of the degradation model, data fit analysis on eight groups of cooler's lifetime test was carried out. The final work indicated this model fit well with the performance degradation of space Stirling cryocoolers due to gas contamination and this model could be used to predict or evaluation the cooler's lifetime. Gaseous contamination will not arouse severe performance degradation until the contaminants accumulate to a certain amount, but it could be fatal when it works. So it is more serious to the coolers whose lifetime is more than 10,000 h. The measures taken to control or minimize its damage were discussed as well. To the long-life cryocooler, internal materials

Emittance growth due to static and radiative space charge forces in an electron bunch compressor

Science.gov (United States)

Talman, Richard; Malitsky, Nikolay; Stulle, Frank

2009-01-01

-21, MOCOS05, available at http://www.JACoW.org], a code with similar capabilities. For this comparison an appropriately new, 50 MeV, “standard chicane” is introduced. Unlike CSRTrack (which neglects vertical forces) the present simulation shows substantial growth of vertical emittance. But “turning off” vertical forces in the UAL code (to match the CSRTrack treatment) brings the two codes into excellent agreement. (iii) Results are also obtained for 5 GeV electrons passing through a previously introduced “standard chicane” [Coherent Synchrotron Radiation, CSR Workshop, Berlin 2002, http://www.desy.de/csr] [of the sort needed for linear colliders and free electron lasers (FEL’s) currently under design or construction]. Relatively little emittance growth is predicted for typical bunch parameters at such high electron energy. Results are obtained for both round beams and ribbon beams (like those actually needed in practice). Little or no excess emittance growth is found for ribbon bunches compared to round bunches of the same charge and bunch width. The UAL string space charge formulation (like TraFic4 and CSRTrack) avoids the regularization step (subtracting the free-space space charge force) which is required (to remove divergence) in some methods. Also, by avoiding the need to calculate a retarded-time, four-dimensional field history, the computation time needed for realistic bunch evolution calculations is modest. Some theories of bunch dilution, because they ascribe emittance growth entirely to CSR, break down at low energy. In the present treatment, as well as CSR, all free-space Coulomb and magnetic space charge forces (but not image forces), and also the centrifugal space charge force (CSCF) are included. Charge-dependent beam steering due to CSCF, as observed recently by Beutner et al. [B. Beutner , in Proceedings of FEL Conference, BESSY, Berlin, Germany, 2006, MOPPH009], is also investigated.

Emittance growth due to static and radiative space charge forces in an electron bunch compressor

Directory of Open Access Journals (Sweden)

Richard Talman

2009-01-01

2004 FEL Conference, pp. 18–21, MOCOS05, available at http://www.JACoW.org], a code with similar capabilities. For this comparison an appropriately new, 50 MeV, “standard chicane” is introduced. Unlike CSRTrack (which neglects vertical forces the present simulation shows substantial growth of vertical emittance. But “turning off” vertical forces in the UAL code (to match the CSRTrack treatment brings the two codes into excellent agreement. (iii Results are also obtained for 5 GeV electrons passing through a previously introduced “standard chicane” [Coherent Synchrotron Radiation, CSR Workshop, Berlin 2002, http://www.desy.de/csr] [of the sort needed for linear colliders and free electron lasers (FEL’s currently under design or construction]. Relatively little emittance growth is predicted for typical bunch parameters at such high electron energy. Results are obtained for both round beams and ribbon beams (like those actually needed in practice. Little or no excess emittance growth is found for ribbon bunches compared to round bunches of the same charge and bunch width. The UAL string space charge formulation (like TraFic4 and CSRTrack avoids the regularization step (subtracting the free-space space charge force which is required (to remove divergence in some methods. Also, by avoiding the need to calculate a retarded-time, four-dimensional field history, the computation time needed for realistic bunch evolution calculations is modest. Some theories of bunch dilution, because they ascribe emittance growth entirely to CSR, break down at low energy. In the present treatment, as well as CSR, all free-space Coulomb and magnetic space charge forces (but not image forces, and also the centrifugal space charge force (CSCF are included. Charge-dependent beam steering due to CSCF, as observed recently by Beutner et al. [B. Beutner et al., in Proceedings of FEL Conference, BESSY, Berlin, Germany, 2006, MOPPH009], is also investigated.

Large size space construction for space exploitation

Science.gov (United States)

Kondyurin, Alexey

2016-07-01

Space exploitation is impossible without large space structures. We need to make sufficient large volume of pressurized protecting frames for crew, passengers, space processing equipment, & etc. We have to be unlimited in space. Now the size and mass of space constructions are limited by possibility of a launch vehicle. It limits our future in exploitation of space by humans and in development of space industry. Large-size space construction can be made with using of the curing technology of the fibers-filled composites and a reactionable matrix applied directly in free space. For curing the fabric impregnated with a liquid matrix (prepreg) is prepared in terrestrial conditions and shipped in a container to orbit. In due time the prepreg is unfolded by inflating. After polymerization reaction, the durable construction can be fitted out with air, apparatus and life support systems. Our experimental studies of the curing processes in the simulated free space environment showed that the curing of composite in free space is possible. The large-size space construction can be developed. A project of space station, Moon base, Mars base, mining station, interplanet space ship, telecommunication station, space observatory, space factory, antenna dish, radiation shield, solar sail is proposed and overviewed. The study was supported by Humboldt Foundation, ESA (contract 17083/03/NL/SFe), NASA program of the stratospheric balloons and RFBR grants (05-08-18277, 12-08-00970 and 14-08-96011).

Normal anatomy and abnormal patterns of the supraspinatus muscle: Ultrasound versus surgery. Analysis of the possible sources of misdiagnosis; Anatomia normale e quadri patologici del muscolo sovraspinato: Confronto tra ecografia e chirurgia. Analisi delle possibili fonti di errore diagnostico

Energy Technology Data Exchange (ETDEWEB)

Montrucchio, Edgardo [Ospedale S. Andrea, La Spezia (Italy); Iovane, Angelo; Midiri, Massimo; Finazzo, Mario; La Tona, Giuseppe; Lagalla, Roberto [Palermo, Univ. (Italy). Istituto di Radiologia ``Piero Cignolini``

1997-04-01

The supraspinatus muscle performs about 60 % of the elevation-abduction motion of the arm; it has a prominent functional role among the extra rotational muscles of the shoulder and is the most injured in subacromial space conditions. Seventy-four patients, aged 21-64 years, were examined to compare ultrasonography (US) results with surgical findings in supraspinatus conditions and to analyze the possible pitfalls in US diagnosis. All the patients underwent conventional X-ray US and then surgery or arthroscopy. The following criteria were considered: morphology, thickness, echotexture, the convexity of the superior border of supraspinatus tendon, the relationships with the subacromial bursa and the tendon of the biceps long head, the regularity of the bone cortex of the humeral head. US showed: perforating focal injuries in 21 patients; deep focal injuries in 10 patients; intramural focal injuries in 6 patients; superficial focal injuries in 8 patients; complete tendon tear with detachment in 19 cases. 62/74 US diagnoses were surgically confirmed, with a specificity of 83.7 %. In their experience, US provided very useful information about the pattern, size and site of the injuries and was very helpful in the surgical planning.

Normal anatomy and abnormal patterns of the supraspinatus muscle: Ultrasound versus surgery. Analysis of the possible sources of misdiagnosis

International Nuclear Information System (INIS)

Montrucchio, Edgardo; Iovane, Angelo; Midiri, Massimo; Finazzo, Mario; La Tona, Giuseppe; Lagalla, Roberto

1997-01-01

The supraspinatus muscle performs about 60 % of the elevation-abduction motion of the arm; it has a prominent functional role among the extra rotational muscles of the shoulder and is the most injured in subacromial space conditions. Seventy-four patients, aged 21-64 years, were examined to compare ultrasonography (US) results with surgical findings in supraspinatus conditions and to analyze the possible pitfalls in US diagnosis. All the patients underwent conventional X-ray US and then surgery or arthroscopy. The following criteria were considered: morphology, thickness, echotexture, the convexity of the superior border of supraspinatus tendon, the relationships with the subacromial bursa and the tendon of the biceps long head, the regularity of the bone cortex of the humeral head. US showed: perforating focal injuries in 21 patients; deep focal injuries in 10 patients; intramural focal injuries in 6 patients; superficial focal injuries in 8 patients; complete tendon tear with detachment in 19 cases. 62/74 US diagnoses were surgically confirmed, with a specificity of 83.7 %. In their experience, US provided very useful information about the pattern, size and site of the injuries and was very helpful in the surgical planning

Surgery for subacromial impingement syndrome in relation to occupational exposures, lifestyle factors and diabetes mellitus: a nationwide nested case-control study.

Science.gov (United States)

Dalbøge, Annett; Frost, Poul; Andersen, Johan Hviid; Svendsen, Susanne Wulff

2017-10-01

To estimate the risk of surgery for subacromial impingement syndrome (SIS) in relation to occupational exposures, lifestyle factors and diabetes mellitus. We conducted a case-control study nested in a register-based cohort study of the Danish working population. For each of 3000 first-time cases of surgery for SIS, two age-matched and sex-matched controls were drawn. Cases and controls received a questionnaire on job history and other factors. Job histories were combined with a psychosocial job exposure matrix (JEM) and the updated Shoulder JEM, which provided exposure intensities on measurement scales. Ten-year cumulative exposures to upper arm elevation >90°, repetitive shoulder movements, forceful shoulder exertions and hand-arm vibrations (HAVs) were estimated. We used conditional logistic regression. There were 5396 persons (60%) who answered the questionnaire. For occupational mechanical exposures, the adjusted OR (OR adj ) ranged from 1.9 (95% CI 1.5 to 2.5 for HAVs) to 2.5 (95% CI 1.9 to 3.5 for force) among men and 1.7 (95% CI 1.2 to 2.5 for HAVs) to 2.0 (95% CI 1.3 to 2.9 for force) among women. No statistically significant associations were found for occupational psychosocial factors. Body mass index (BMI) and pack-years of smoking showed OR adj up to 2.0. Diabetes mellitus showed OR adj of 1.5 (95% CI 1.1 to 2.2) for men and 2.2 (95% CI 1.4 to 3.4) for women. Our findings add to the evidence of an increased risk of surgery for SIS in relation to occupational cumulative mechanical exposures, even when an increased risk in relation to BMI, smoking and diabetes mellitus is taken into account. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Risk of Impaired Control of Spacecraft/Associated Systems and Decreased Mobility Due to Vestibular/Sensorimotor Alterations Associated with Space flight

Science.gov (United States)

Bloomberg, Jacob J.; Reschke, Millard F.; Clement, Gilles R.; Mulavara, Ajitkumar P.; Taylor, Laura C..

2015-01-01

Control of vehicles and other complex systems is a high-level integrative function of the central nervous system (CNS). It requires well-functioning subsystem performance, including good visual acuity, eye-hand coordination, spatial and geographic orientation perception, and cognitive function. Evidence from space flight research demonstrates that the function of each of these subsystems is altered by removing gravity, a fundamental orientation reference, which is sensed by vestibular, proprioceptive, and haptic receptors and used by the CNS for spatial orientation, posture, navigation, and coordination of movements. The available evidence also shows that the degree of alteration of each subsystem depends on a number of crew- and mission-related factors. There is only limited operational evidence that these alterations cause functional impacts on mission-critical vehicle (or complex system) control capabilities. Furthermore, while much of the operational performance data collected during space flight has not been available for independent analysis, those that have been reviewed are somewhat equivocal owing to uncontrolled (and/or unmeasured) environmental and/or engineering factors. Whether this can be improved by further analysis of previously inaccessible operational data or by development of new operational research protocols remains to be seen. The true operational risks will be estimable only after we have filled the knowledge gaps and when we can accurately assess integrated performance in off-nominal operational settings (Paloski et al. 2008). Thus, our current understanding of the Risk of Impaired Control of Spacecraft/Associated Systems and Decreased Mobility Due to Vestibular/Sensorimotor Alterations Associated with Space flight is limited primarily to extrapolation of scientific research findings, and, since there are limited ground-based analogs of the sensorimotor and vestibular changes associated with space flight, observation of their functional

Solving Component Structural Dynamic Failures Due to Extremely High Frequency Structural Response on the Space Shuttle Program

Science.gov (United States)

Frady, Greg; Nesman, Thomas; Zoladz, Thomas; Szabo, Roland

2010-01-01

For many years, the capabilities to determine the root-cause failure of component failures have been limited to the analytical tools and the state of the art data acquisition systems. With this limited capability, many anomalies have been resolved by adding material to the design to increase robustness without the ability to determine if the design solution was satisfactory until after a series of expensive test programs were complete. The risk of failure and multiple design, test, and redesign cycles were high. During the Space Shuttle Program, many crack investigations in high energy density turbomachines, like the SSME turbopumps and high energy flows in the main propulsion system, have led to the discovery of numerous root-cause failures and anomalies due to the coexistences of acoustic forcing functions, structural natural modes, and a high energy excitation, such as an edge tone or shedding flow, leading the technical community to understand many of the primary contributors to extremely high frequency high cycle fatique fluid-structure interaction anomalies. These contributors have been identified using advanced analysis tools and verified using component and system tests during component ground tests, systems tests, and flight. The structural dynamics and fluid dynamics communities have developed a special sensitivity to the fluid-structure interaction problems and have been able to adjust and solve these problems in a time effective manner to meet budget and schedule deadlines of operational vehicle programs, such as the Space Shuttle Program over the years.

Evaluating the Effects of local Injections of Bupivacaine and Triamcinolone Acetate on Shoulder Joint Pain and Restricted Range of Motion Following Cerebrovascular Accidents

Directory of Open Access Journals (Sweden)

Asadollah Saadat Niaki M.D.

2011-06-01

Full Text Available Background: Shoulder pain is a common complication of cerebrovascular accidents. This study was conducted to assess the effects of local injections of bupivacaine and triamcinolone acetate on shoulder joint pain and on restricted range of motion following brain events. Methods: This single-blind clinical trial study included 35 patients with chronic shoulder pain (the controls and 35 patients with chronic shoulder pain due to brain events (the case group. The study was done at Imam Hossein Hospital & Gandhi Day Clinic during the year 2008-2010. The patients in the two groups received bupivacaine and triamcinolone acetate for subacromial bursa injection and suprascapular nerve block by following the protocol described by Dangoisse et al. The patients were followed up for 12 weeks and they were evaluated for pain and range of motion 1, 6, and 12 weeks after the injections.Results: The mean age of the patients was 60.9±9.07 years. Statistically significant improvements in pain score (P=0.001 and shoulder joint range of motion (P=0.001 were observed in patients with chronic shoulder pain versus patients with brain events 12 weeks after suprascapulare nerve block and subacromial bours injections by bupivacaine and triamcinolone acetate.Conclusion: Suprascapular nerve block and subacromial bursa injections of bupivacaine and triamcinolone acetate is a safe and efficacious treatment for the treatment of chronic shoulder pain and restricted range of motion but it is not efficacious or of significant value for the treatment of shoulder pain in patients with brain events.

Effect of methylprednisolone use on the rotator cuff in rats: biomechanical and histological study

Directory of Open Access Journals (Sweden)

Gustavo Vinícius Ghellioni

2015-06-01

Full Text Available OBJECTIVE: To evaluate the influence of treatment with different doses of methylprednisolone on the mechanical resistance and possible histological alterations of the rotator cuff tendon in rats.METHODS: Male Wistar rats were divided randomly into four treatment groups: sham, vehicle or 0.6 mg/kg or 6.0 mg/kg of methylprednisolone. Changes to mechanical resistance (in N and histological parameters (fibrillar appearance, presence of collagen, edema and vascular proliferation of the rotator cuff tendon were evaluated. The analyses were conducted after administration of one treatment (24 h afterwards, two treatments (7 days afterward or three treatments (14 days afterwards, into the subacromial space.RESULTS: Seven and fourteen days after the treatments were started, it was found that in a dose-dependent manner, methylprednisolone reduced the mechanical resistance of the rotator cuff tendon (p < 0.05 in relation to the vehicle group. Modifications to the histological parameters were observed on the 7th and 14th days after the first infiltration, especially regarding the presence of collagen and vascular proliferation, for the dose of 0.6 mg/kg of methylprednisolone, and also regarding the presence of collagen, edema and vascular proliferation for the dose of 6.0 mg/kg of corticoid.CONCLUSION: The results obtained demonstrated a relationship between methylprednisolone use through infiltration into the subacromial space and reduction of the mechanical resistance of and histological modifications to the rotator cuff tendon in rats.

Space dissipative structures

International Nuclear Information System (INIS)

Chernousenko, V.M.; Kuklin, V.M.; Panachenko, I.P.; Vorob'yov, V.M.

1990-01-01

This paper reports on a wide spectrum of oscillations that is excited due to the evolution instabilities, being in a weak above-threshold state, in the inequilibrium media with decaying spectrum. In this case the pumping, whose part is played by an intensive wave or occupation inversion in the active medium, synchronized the phases of excited modes and, thus, forms the space dissipative structure of the field. In dissipative nonlinear media with nondecaying spectrum the space structures, formed due to the development of instability, experience small-scale hexagonal modulation

Shoulder arthography in rheumatoid arthritis

International Nuclear Information System (INIS)

Reinbold, W.D.; Hehne, H.J.; Rau, W.S.; Freiburg Univ.

1983-01-01

Shoulder arthrography in a patient with rheumatoid arthritis is performed to differentiate between a rheumatoid flare and limitation of motion secondary to tear in the rotator cuff. Accurate diagnosis is important because of the therapeutic implications. The arthrographic findings characteristic of rheumatoid involvement of the shoulder joint are nodular filling defects of the joint, the subacromial and subdeltoideal bursa in case of rotator cuff tear, irregular capsular attachment, contracted joint space and visualized lymphatic drainage. A dilatation of the biceps tendon sheath has not been shown. (orig.) [de

Three-dimensional scapular dyskinesis in hook-plated acromioclavicular dislocation including hook motion.

Science.gov (United States)

Kim, Eugene; Lee, Seunghee; Jeong, Hwa-Jae; Park, Jai Hyung; Park, Se-Jin; Lee, Jaewook; Kim, Woosub; Park, Hee Jin; Lee, So Yeon; Murase, Tsuyoshi; Sugamoto, Kazuomi; Ikemoto, Sumika

2018-06-01

The purpose of this study is to analyze the 3-dimensional scapular dyskinesis and the kinematics of a hook plate relative to the acromion after hook-plated acromioclavicular dislocation in vivo. Reported complications of acromioclavicular reduction using a hook plate include subacromial erosion and impingement. However, there are few reports of the 3-dimensional kinematics of the hook and scapula after the aforementioned surgical procedure. We studied 15 cases of acromioclavicular dislocation treated with a hook plate and 15 contralateral normal shoulders using computed tomography in the neutral and full forward flexion positions. Three-dimensional motion of the scapula relative to the thorax during arm elevation was analyzed using a computer simulation program. We also measured the distance from the tip of the hook plate to the greater tuberosity, as well as the angular motion of the plate tip in the subacromial space. Decreased posterior tilting (22° ± 10° vs 31° ± 8°) in the sagittal plane and increased external rotation (19° ± 9° vs 7° ± 5°) in the axial plane were evident in the affected shoulders. The mean values of translation of the hook plate and angular motion against the acromion were 4.0 ± 1.6 mm and 15° ± 8°, respectively. The minimum value of the distance from the hook plate to the humeral head tuberosity was 6.9 mm during arm elevation. Acromioclavicular reduction using a hook plate may cause scapular dyskinesis. Translational and angular motion of the hook plate against the acromion could lead to subacromial erosion. However, the hook does not seem to impinge directly on the humeral head. Copyright © 2017 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.

Limitations Of The Current State Space Modelling Approach In Multistage Machining Processes Due To Operation Variations

Science.gov (United States)

Abellán-Nebot, J. V.; Liu, J.; Romero, F.

2009-11-01

The State Space modelling approach has been recently proposed as an engineering-driven technique for part quality prediction in Multistage Machining Processes (MMP). Current State Space models incorporate fixture and datum variations in the multi-stage variation propagation, without explicitly considering common operation variations such as machine-tool thermal distortions, cutting-tool wear, cutting-tool deflections, etc. This paper shows the limitations of the current State Space model through an experimental case study where the effect of the spindle thermal expansion, cutting-tool flank wear and locator errors are introduced. The paper also discusses the extension of the current State Space model to include operation variations and its potential benefits.

Deformation of two welded elastic half-spaces due to a long inclined ...

Indian Academy of Sciences (India)

2Department of Mathematics, University of Delhi South Campus, New Delhi 110 021, India. ∗e-mail: ... Airy stress function for a tensile line source in two welded half-spaces are first obtained. These expressions ... computing the displacement and stress fields around a long inclined tensile fault near an internal boundary. 1.

A new system to quantify uncertainties in LEO satellite position determination due to space weather events

Data.gov (United States)

National Aeronautics and Space Administration — We propose to develop a new system for quantitative assessment of uncertainties in LEO satellite position caused by storm time changes in space environmental...

Radiation risk in space exploration

International Nuclear Information System (INIS)

Schimmerling, W.; Wilson, J.W.; Cucinotta, F.; Kim, M.H.Y.

1997-01-01

Humans living and working in space are exposed to energetic charged particle radiation due to galactic cosmic rays and solar particle emissions. In order to keep the risk due to radiation exposure of astronauts below acceptable levels, the physical interaction of these particles with space structures and the biological consequences for crew members need to be understood. Such knowledge is, to a large extent, very sparse when it is available at all. Radiation limits established for space radiation protection purposes are based on extrapolation of risk from Japanese survivor data, and have been found to have large uncertainties. In space, attempting to account for large uncertainties by worst-case design results in excessive costs and accurate risk prediction is essential. It is best developed at ground-based laboratories, using particle accelerator beams to simulate individual components of space radiation. Development of mechanistic models of the action of space radiation is expected to lead to the required improvements in the accuracy of predictions, to optimization of space structures for radiation protection and, eventually, to the development of biological methods of prevention and intervention against radiation injury. (author)

Space Shuttle and Space Station Radio Frequency (RF) Exposure Analysis

Science.gov (United States)

Hwu, Shian U.; Loh, Yin-Chung; Sham, Catherine C.; Kroll, Quin D.

2005-01-01

This paper outlines the modeling techniques and important parameters to define a rigorous but practical procedure that can verify the compliance of RF exposure to the NASA standards for astronauts and electronic equipment. The electromagnetic modeling techniques are applied to analyze RF exposure in Space Shuttle and Space Station environments with reasonable computing time and resources. The modeling techniques are capable of taking into account the field interactions with Space Shuttle and Space Station structures. The obtained results illustrate the multipath effects due to the presence of the space vehicle structures. It's necessary to include the field interactions with the space vehicle in the analysis for an accurate assessment of the RF exposure. Based on the obtained results, the RF keep out zones are identified for appropriate operational scenarios, flight rules and necessary RF transmitter constraints to ensure a safe operating environment and mission success.

Radiotherapy for shoulder impingement; Bestrahlung beim Impingementsyndrom des Schultergelenks

Energy Technology Data Exchange (ETDEWEB)

Adamietz, B. [Universitaetsklinikum Erlangen (Germany). Inst. fuer Radiologie; Sauer, R.; Keilholz, L. [Universitaetsklinikum Erlangen (Germany). Strahlentherapeutische Klinik

2008-05-15

Background and Purpose: Up to now, degenerative shoulder diseases were summarized by the term 'periarthritis humeroscapularis'. Actual shoulder diseases can be differentiated etiopathologically according to a primary and secondary impingement syndrome. Narrowing of the subacromial space, which is caused by an osseous shape variant, leads to primary impingement. Secondary impingement develops, when the subacromial space is reduced by swelling tissue below the osseous shoulder roof. This study aimed for the exact diagnosis to indicate therapy and to classify the results according to the Constant score. Patients and Methods: From August 1999 to September 2002, 102 patients with 115 shoulder joint conditions underwent radiation therapy (RT). All joints received two RT series (6 x 0.5 Gy/series) applied in two to three weekly fractions, totaling a dosage of 6.0 Gy (250 kV, 15 mAs, 1-mm Cu filter). The second RT course started 6 weeks after the end of the first. 115 shoulders were examined before RT, 6 weeks after the second RT course and, finally, during the follow-up from January to May 2003. Results: Pain relief was achieved in 94/115 shoulder joints (82%) after 18-month follow-up (median). A significant difference existed between secondary impingement and primary/non-impingement according to response. Tendinosis calcarea, bursitis subdeltoidea, tendovaginitis of the long biceps tendon, and capsulitis adhaesiva responded well to therapy. Conclusion: Shoulder diseases of secondary impingement demonstrate a good response to RT. Less or no benefit was found in primary impingement syndrome or complete rotator cuff disruption and acute shoulder injuries, respectively. (orig.)

Space Charge Effects

CERN Document Server

Ferrario, M.; Palumbo, L.

2014-12-19

The space charge forces are those generated directly by the charge distribution, with the inclusion of the image charges and currents due to the interaction of the beam with a perfectly conducting smooth pipe. Space charge forces are responsible for several unwanted phenomena related to beam dynamics, such as energy loss, shift of the synchronous phase and frequency , shift of the betatron frequencies, and instabilities. We will discuss in this lecture the main feature of space charge effects in high-energy storage rings as well as in low-energy linacs and transport lines.

Space Commercialization and the Development of Space Law

Science.gov (United States)

Yun, Zhao

2017-05-01

Shortly after the launch of the first manmade satellite in 1957, the United Nations (UN) took the lead in formulating international rules governing space activities. The five international conventions (i.e., the 1967 Outer Space Treaty, the 1968 Rescue Agreement, the 1972 Liability Convention, the 1975 Registration Convention, and the 1979 Moon Agreement) within the UN framework constitute the nucleus of space law; laying a solid legal foundation for securing the smooth development of space activities over the next few decades. Outer space was soon found to be a place with abundant opportunities for commercialization: with telecommunications services the first and most successful commercial application followed by remote sensing and global navigation services. In the last decade, the rapid development of space technologies brought space tourism and space mining to the forefront as well. With more and more commercial activities taking place on a daily basis from the 1980s on, existing space law faces severe challenges. The five conventions, which were enacted at a time when space was monopolized by two superpowers—the United States and the former Soviet Union—also failed to take into account the commercial aspect of space activities. Although there are urgent needs for new rules to deal with the ongoing trend of space commercialization, the international society faces difficulties in adopting new rules due to diversified national interests. As a result, it adjusts legislative strategies by enacting soft laws. In view of the difficulty in adopting binding rules at the international level, states are encouraged to enact their own national space legislation providing sufficient guidance for their domestic space commercial activities. It is expected that the development of soft laws and national space legislation will be the mainstream regulatory activities in the space field for the foreseeable future.

Space charge effects of CSR

International Nuclear Information System (INIS)

Liu Yong; Xia Jiawen; Xu Xiangyang; Lu Xiaowen; Wu Junli

2000-01-01

Cooler Storage Ring (CSR), and upgrading program planned at the Heavy Ion Research Facility in Lanzhou (HIRFL), will supply beams with higher quality and intensity. Space charge effects should be considered due to this magnitude of intensity in CSR. The concept and some phenomena of space charge effects are discussed. Space charge intensity limit and space charge tune shift of normal CSR operation are given. It is of significance for the construction and operation of the future facility

Chemical Facial Cellulitis Due to Inadvertent Injection of Formalin into Oral Tissue Space.

Science.gov (United States)

Bector, Aditi; Virk, Pawandeep Sandhu; Arakeri, Gururaj

2015-11-05

This paper reports the accidental injection of formalin into oral tissue space, in an 8-year old child resulting in chemical facial necrotizing cellulitis and its management. The common practice of keeping formalin in local anesthesia vials should be avoided by dental clinics, to prevent such unfortunate incidents.

Shoulder impingement syndrome: diagnostic accuracy of magnetic resonance imaging and radiographic signs

International Nuclear Information System (INIS)

Williamson, M.P.; Chandnani, V.P.; Baird, D.E.; Deberardino, T.M.; Swenson, G.W.; Hansen, M.F.

1994-01-01

Shoulder impingement syndrome is commonly encountered in orthopaedics. In a blinded retrospective study, magnetic resonance imaging and roentgenographic signs in 41 patients with clinical signs of impingement syndrome were compared with 40 control patients. Statistically significant differences between the groups included the absence of subacromial fat, as well as the presence of a supraspinatus tear, subacromial osteophytes, and a decreased coracohumeral distance. Other signs reported to occur in patients with impingement syndrome did not vary significantly in the population studied. 20 refs., 12 figs

Chemical facial cellulitis due to inadvertent injection of formalin into oral tissue space

Directory of Open Access Journals (Sweden)

Aditi Bector

2015-12-01

Full Text Available This paper reports the accidental injection of formalin into oral tissue space, in an 8-year old child resulting in chemical facial necrotizing cellulitis and its management. The common practice of keeping formalin in local anesthesia vials should be avoided by dental clinics, to prevent such unfortunate incidents.

Compliance evaluation of removable space maintainer or space regainer usage

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Revanti Ramadhani

2018-01-01

Full Text Available Premature loss could cause a problem with the tooth arrangement or the dental arch size. A space left by the primary tooth loss could cause migration of the adjacent teeth. As a result, space will be narrowed and undermined the eruption of the permanent teeth. The success of the space maintainer or space regainer usage due to the premature loss marked by space for the replacement of the permanent teeth. The purpose of this research was to evaluate the compliance of children in wearing a space maintainer or space regainer after insertion at Pedodontics Installation of Faculty of Dentistry Universitas Padjadjaran Dental Hospital, Bandung, Indonesia. The research method was descriptive survey technique. The sample consisted of 30 patients selected using the total sampling technique. Data were obtained with a questionnaire and statistically analyzed. The results showed that majority of the children uses the removable space maintainer or the space regainer daily was only about 23,3% overall. Most of the children only use the removable space maintainer or the space regainer for sometimes. The research concluded that the low rate of pedodontic patients compliance at Pedodontics Installation of Faculty of Dentistry Universitas Padjadjaran Dental Hospital in the usage of the removable space maintainer or the space regainer was usually caused by pain or discomfort. This fact was evidence of a low awareness of parents in preventing malocclusion to their children.

Space Inside a Liquid Sphere Transforms into De Sitter Space by Hilbert Radius

Science.gov (United States)

Rabounski, Dmitri; Borissova, Larissa

2010-04-01

Consider space inside a sphere of incompressible liquid, and space surrounding a mass-point. Metrics of the spaces were deduced in 1916 by Karl Schwarzschild. 1) Our calculation shows that a liquid sphere can be in the state of gravitational collapse (g00 = 0) only if its mass and radius are close to those of the Universe (M = 8.7x10^55 g, a = 1.3x10^28 cm). However if the same mass is presented as a mass-point, the radius of collapse rg (Hilbert radius) is many orders lesser: g00 = 0 realizes in a mass-point's space by other conditions. 2) We considered a liquid sphere whose radius meets, formally, the Hilbert radius of a mass-point bearing the same mass: a = rg, however the liquid sphere is not a collapser (see above). We show that in this case the metric of the liquid sphere's internal space can be represented as de Sitter's space metric, wherein λ = 3/a^2 > 0: physical vacuum (due to the λ-term) is the same as the field of an ideal liquid where ρ0 0 (the mirror world liquid). The gravitational redshift inside the sphere is produced by the non-Newtonian force of repulsion (which is due to the λ-term, λ = 3/a^2 > 0); it is also calculated.

Wastes in space

International Nuclear Information System (INIS)

2011-01-01

As human space activities have created more wastes on low and high Earth orbits over the past 50 years than the solar system injected meteorites over billions of years, this report gives an overview of this problem. It identifies the origins of these space debris and wastes (launchers, combustion residues, exploitation wastes, out-of-use satellites, accidental explosions, accidental collisions, voluntary destructions, space erosion), and proposes a stock list of space wastes. Then, it distinguishes the situation for the different orbits: low Earth orbit or LEO (traffic, presence of the International Space Station), medium Earth orbits or MEO (traffic, operating satellites, wastes), geostationary Earth orbit or GEO (traffic, operating satellites, wastes). It also discusses wastes and bacteria present on the moon (due to Apollo missions or to crash tests). It evokes how space and nuclear industry is concerned, and discusses the re-entry issue (radioactive boomerang, metallic boomerang). It also indicates elements of international law

Conservative treatment for patients with subacromial impingement: Changes in clinical core outcomes and their relation to specific rehabilitation parameters

Directory of Open Access Journals (Sweden)

Mikkel B. Clausen

2018-02-01

Full Text Available Background Impaired patient-reported shoulder function and pain, external-rotation strength, abduction strength, and abduction range-of-motion (ROM is reported in patients with subacromial impingement (SIS. However, it is unknown how much strength and ROM improves in real-life practice settings with current care. Furthermore, outcomes of treatment might depend on specific rehabilitation parameters, such as the time spent on exercises (exercise-time, number of physiotherapy sessions (physio-sessions and number of corticosteroid injections, respectively. However, this has not previously been investigated. The purpose of this study was to describe changes in shoulder strength, ROM, patient-reported function and pain, in real-life practice settings, and explore the association between changes in clinical core outcomes and specific rehabilitation parameters. Methods Patients diagnosed with SIS at initial assessment at an outpatient hospital clinic using predefined criteria’s, who had not undergone surgery after 6 months, were included in this prospective cohort study. After initial assessment (baseline, all patients underwent treatment as usual, with no interference from the investigators. The outcomes Shoulder Pain and Disability Index (SPADI:0–100, average pain (NRS:0–10, external rotation strength, abduction strength and abduction ROM, pain during each test (NRS:0–10, were collected at baseline and at six month follow-up. Amount of exercise-time, physio-sessions and steroid-injections was recorded at follow-up. Changes in outcomes were analyzed using Wilcoxon Signed-Rank test, and the corresponding effect sizes (ES were estimated. The associations between changes in outcomes and rehabilitation parameters were explored using multiple regression analyses. Results Sixty-three patients completed both baseline and follow-up testing. Significant improvements were seen in SPADI (19 points, ES:0.53, p  0.2. A higher number of physio-sessions was

Space and the American imagination

Science.gov (United States)

Mccurdy, Howard E.

1994-01-01

The introduction will set out the principal theme of the book: that the rise of the U.S. space program was due to a concerted effort by science writers, engineers, industrialists, and civic and political leaders to create a popular culture of space exploration based on important elements of American social life (such as frontier mythology, fears about the cold war, and the rise of the consumer culture). Much of the disillusionment with the NASA space program which set in during the third decade of space flight can be traced to a widening gap between popular expectations and the reality of space exploration.

46 CFR 92.20-35 - Hospital space.

Science.gov (United States)

2010-10-01

... 46 Shipping 4 2010-10-01 2010-10-01 false Hospital space. 92.20-35 Section 92.20-35 Shipping COAST... ARRANGEMENT Accommodations for Officers and Crew § 92.20-35 Hospital space. (a) Each vessel which in the... crew of 12 or more, must be provided with a hospital space. This space must be situated with due regard...

46 CFR 72.20-35 - Hospital space.

Science.gov (United States)

2010-10-01

... 46 Shipping 3 2010-10-01 2010-10-01 false Hospital space. 72.20-35 Section 72.20-35 Shipping COAST... Accommodations for Officers and Crew § 72.20-35 Hospital space. (a) Each vessel which in the ordinary course of... more, must be provided with a hospital space. This space must be situated with due regard to the...

46 CFR 168.15-35 - Hospital space.

Science.gov (United States)

2010-10-01

... 46 Shipping 7 2010-10-01 2010-10-01 false Hospital space. 168.15-35 Section 168.15-35 Shipping... VESSELS Accommodations § 168.15-35 Hospital space. (a) Each vessel must be provided with a hospital space. This space must be situated with due regard for the comfort of the sick so that they may receive proper...

Noncommutative phase spaces on Aristotle group

Directory of Open Access Journals (Sweden)

Ancille Ngendakumana

2012-03-01

Full Text Available We realize noncommutative phase spaces as coadjoint orbits of extensions of the Aristotle group in a two dimensional space. Through these constructions the momenta of the phase spaces do not commute due to the presence of a naturally introduced magnetic eld. These cases correspond to the minimal coupling of the momentum with a magnetic potential.

Study on the mapping of dark matter clustering from real space to redshift space

Energy Technology Data Exchange (ETDEWEB)

Zheng, Yi; Song, Yong-Seon, E-mail: yizheng@kasi.re.kr, E-mail: ysong@kasi.re.kr [Korea Astronomy and Space Science Institute, Daejeon 34055 (Korea, Republic of)

2016-08-01

The mapping of dark matter clustering from real space to redshift space introduces the anisotropic property to the measured density power spectrum in redshift space, known as the redshift space distortion effect. The mapping formula is intrinsically non-linear, which is complicated by the higher order polynomials due to indefinite cross correlations between the density and velocity fields, and the Finger-of-God effect due to the randomness of the peculiar velocity field. Whilst the full higher order polynomials remain unknown, the other systematics can be controlled consistently within the same order truncation in the expansion of the mapping formula, as shown in this paper. The systematic due to the unknown non-linear density and velocity fields is removed by separately measuring all terms in the expansion directly using simulations. The uncertainty caused by the velocity randomness is controlled by splitting the FoG term into two pieces, 1) the ''one-point' FoG term being independent of the separation vector between two different points, and 2) the ''correlated' FoG term appearing as an indefinite polynomials which is expanded in the same order as all other perturbative polynomials. Using 100 realizations of simulations, we find that the Gaussian FoG function with only one scale-independent free parameter works quite well, and that our new mapping formulation accurately reproduces the observed 2-dimensional density power spectrum in redshift space at the smallest scales by far, up to k ∼ 0.2 Mpc{sup -1}, considering the resolution of future experiments.

Study on the mapping of dark matter clustering from real space to redshift space

International Nuclear Information System (INIS)

Zheng, Yi; Song, Yong-Seon

2016-01-01

The mapping of dark matter clustering from real space to redshift space introduces the anisotropic property to the measured density power spectrum in redshift space, known as the redshift space distortion effect. The mapping formula is intrinsically non-linear, which is complicated by the higher order polynomials due to indefinite cross correlations between the density and velocity fields, and the Finger-of-God effect due to the randomness of the peculiar velocity field. Whilst the full higher order polynomials remain unknown, the other systematics can be controlled consistently within the same order truncation in the expansion of the mapping formula, as shown in this paper. The systematic due to the unknown non-linear density and velocity fields is removed by separately measuring all terms in the expansion directly using simulations. The uncertainty caused by the velocity randomness is controlled by splitting the FoG term into two pieces, 1) the ''one-point' FoG term being independent of the separation vector between two different points, and 2) the ''correlated' FoG term appearing as an indefinite polynomials which is expanded in the same order as all other perturbative polynomials. Using 100 realizations of simulations, we find that the Gaussian FoG function with only one scale-independent free parameter works quite well, and that our new mapping formulation accurately reproduces the observed 2-dimensional density power spectrum in redshift space at the smallest scales by far, up to k ∼ 0.2 Mpc -1 , considering the resolution of future experiments.

Two-dimensional deformation of a uniform half-space due to non ...

Indian Academy of Sciences (India)

quake sources cannot be represented by double- couple source mechanism which models a shear fault. According to Sipkin (1986), the non-double- couple mechanism might be due to ..... Commission, New Delhi for the financial support in the form of Junior Research Fellowship sanc- tioned to R C Verma and Major ...

Drug Information in Space Medicine

Science.gov (United States)

Bayuse, Tina M.

2009-01-01

Published drug information is widely available for terrestrial conditions. However, information on dosing, administration, drug interactions, stability, and side effects is scant as it relates to use in Space Medicine. Multinational crews on board the International Space Station present additional challenges for drug information because medication nomenclature, information available for the drug as well as the intended use for the drug is not standard across countries. This presentation will look at unique needs for drug information and how the information is managed in Space Medicine. A review was conducted of the drug information requests submitted to the Johnson Space Center Pharmacy by Space Medicine practitioners, astronaut crewmembers and researchers. The information requested was defined and cataloged. A list of references used was maintained. The wide range of information was identified. Due to the information needs for the medications in the on-board medical kits, the Drug Monograph Project was created. A standard method for answering specific drug information questions was generated and maintained by the Johnson Space Center Pharmacy. The Drug Monograph Project will be presented. Topic-centered requests, including multinational drug information, drug-induced adverse reactions, and medication events due to the environment will be highlighted. Information management of the drug information will be explained. Future considerations for drug information needs will be outlined.

Reduction of potatos due to hydric soil erosion using space technology

Science.gov (United States)

Guyot, E. C.; Ríos, V. H.; Zelaya, D. K.; Soria, F.; Ríos, E.; Padilla, P.

The potato's crop is in the fourth ranking of economic importance in the agricultural Gross Income of Tucuman. The geographical location of its production area makes essential the handling of the hydric soil erosion problems. The purpose of this work is to improve potato crop irrigation management using space information combined with farm practice. The field measurements were carried out using Wide Area Differential Global Position Systems FUGRO OMNISTAR, total station, and double frequency Global Position Systems. The crop irrigation was pursued through scheduling irrigation's software whose input comes from satellites of the Matutinal Constellation (LandSat 7, SACC and TERRA). The preliminary results allowed reprograming the irrigation practices for the new crop's campaign in order to decrease hydric soil erosion.

A solar cycle of spacecraft anomalies due to internal charging

Directory of Open Access Journals (Sweden)

G. L. Wrenn

2002-07-01

Full Text Available It is important to appreciate how the morphology of internal charging of spacecraft systems, due to penetrating electrons, differs from that of the more common surface charging, due to electrons with lower energy. A specific and recurrent anomaly on a geostationary communication satellite has been tracked for ten years so that solar cycle and seasonal dependencies can be clearly established. Concurrent measurements of sunspot number, solar wind speed and 2-day >2 MeV electron fluence are presented to highlight pertinent space weather relationships, and the importance of understanding the complex particle interaction processes involved.Key words. Magnetospheric physics (energetic particles; trapped; solar wind – magnetosphere interactions – space plasma physics (spacecraft sheaths, wakes, charging

Morphological analysis of acromion and hook plate for the fixation of acromioclavicular joint dislocation.

Science.gov (United States)

Yoon, Jong Pil; Lee, Yeon Soo; Song, Geun Soo; Oh, Joo Han

2017-03-01

Acromioclavicular (AC) joint dislocation is a common sports injury. Hook plate fixation is currently widely used to treat this injury, as it can promote the natural healing of the ligament with good clinical outcomes. However, subacromial erosion and impingement are frequently observed post-operatively. It was hypothesized that the morphology and the contact characteristics between the hook portion and the acromion are the main causes of complications after hook plate fixation with the currently available commercial designs. Three-dimensional reconstructed models of the AC joint obtained from the computed tomographic scans of 23 male and 23 female patients (mean age, 61.1 ± 6.3 years) were evaluated, and multiple anatomical parameters were measured. For the subacromial positioning of the hook plate, an actual hook plate (Synthes Inc., West Chester, PA, USA) was scanned, and the contact between the hook plate and the acromion was estimated. The thicknesses of the acromion and distal clavicle were 9.7 ± 1.5 mm (10.7 mm in men; 8.6 mm in women) and 11.3 ± 1.6 mm (11.6 mm in men; 10.0 mm in women), respectively. The width of the acromion was 28.5 ± 3.6 mm. The mean inclination angle between the hook plate and the acromion was 29.3° ± 9.7° (27.9° in men; 30.6° in women). The hook plate made a point contact with the acromion at 9.2 ± 3.3 mm (31.5 %) from the lateral end of the acromion. The results revealed that the hook made a pinpoint contact with the undersurface of the acromion, and this might explain why complications commonly occur after hook plate fixation. The force concentration phenomenon associated with the hook plate of existing designs results from cases of morphological mismatch, such as excessive inclination and improper occupation of the subacromial space.

Approaching the new reality. [changes in NASA space programs due to US economy

Science.gov (United States)

Diaz, Al V.

1993-01-01

The focus on more frequent access to space through smaller, less costly missions, and on NASA's role as a source of technological advance within the U.S. economy is discussed. The Pluto fast flyby mission is examined as an illustration of this approach. Testbeds are to be developed to survive individual programs, becoming permanent facilities, to allow for technological upgrades on an ongoing basis.

Psychosocial issues affecting crews during long-duration international space missions

Science.gov (United States)

Kanas, N.

1998-01-01

Psychosocial issues can negatively impact on crew performance and morale during long-duration international space missions. Major psychosocial factors that have been described in anecdotal reports from space and in studies from analog situations on Earth include: 1) crew heterogeneity due to gender differences, cultural issues, and work experiences and motivations; 2) language and dialect variations; and 3) task versus supportive leadership roles. All of these factors can lead to negative sequelae, such as intra-crew tension and cohesion disruptions. Specific sequelae that can result from single factors include subgrouping and scapegoating due to crew heterogeneity; miscommunication due to major or subtle language differences; and role confusion, competition, and status leveling due to inappropriate leadership role definition. It is time to conduct research exploring the impact of these psychosocial factors and their sequelae on space crews during actual long-duration international space missions.

UWB Technology and Applications on Space Exploration

Science.gov (United States)

Ngo, Phong; Phan, Chau; Gross, Julia; Dusl, John; Ni, Jianjun; Rafford, Melinda

2006-01-01

Ultra-wideband (UWB), also known as impulse or carrier-free radio technology, is one promising new technology. In February 2002, the Federal Communications Commission (FCC) approved the deployment of this technology. It is increasingly recognized that UWB technology holds great potential to provide significant benefits in many terrestrial and space applications such as precise positioning/tracking and high data rate mobile wireless communications. This talk presents an introduction to UWB technology and some applications on space exploration. UWB is characterized by several uniquely attractive features, such as low impact on other RF systems due to its extremely low power spectral densities, immunity to interference from narrow band RF systems due to its ultra-wide bandwidth, multipath immunity to fading due to ample multipath diversity, capable of precise positioning due to fine time resolution, capable of high data rate multi-channel performance. The related FCC regulations, IEEE standardization efforts and industry activities also will be addressed in this talk. For space applications, some projects currently under development at NASA Johnson Space Center will be introduced. These include the UWB integrated communication and tracking system for Lunar/Mars rover and astronauts, UWB-RFID ISS inventory tracking, and UWB-TDOA close-in high resolution tracking for potential applications on robonaut.

Optimizing Light for Long Duration Space Exploration

Data.gov (United States)

National Aeronautics and Space Administration — The goal of our work is to optimize lighting that supports vision and serves as a circadian countermeasure for astronauts and ground crew during space missions. Due...

Teleportation schemes in infinite dimensional Hilbert spaces

International Nuclear Information System (INIS)

Fichtner, Karl-Heinz; Freudenberg, Wolfgang; Ohya, Masanori

2005-01-01

The success of quantum mechanics is due to the discovery that nature is described in infinite dimension Hilbert spaces, so that it is desirable to demonstrate the quantum teleportation process in a certain infinite dimensional Hilbert space. We describe the teleportation process in an infinite dimensional Hilbert space by giving simple examples

Rotator Cuff Calcific Tendinitis: Ultrasound-Guided Needling and Lavage Versus Subacromial Corticosteroids: Five-Year Outcomes of a Randomized Controlled Trial.

Science.gov (United States)

de Witte, Pieter Bas; Kolk, Arjen; Overes, Ferdinand; Nelissen, Rob G H H; Reijnierse, Monique

2017-12-01

Barbotage (needling and lavage) is often applied in the treatment of calcific tendinitis of the rotator cuff (RCCT). In a previously published randomized controlled trial, we reported superior clinical and radiological 1-year outcomes for barbotage combined with a corticosteroid injection in the subacromial bursa (SAIC) compared with an isolated SAIC. There are no trials with a midterm or long-term follow-up of barbotage available. To compare the 5-year results of 2 regularly applied treatments of RCCT: ultrasound (US)-guided barbotage combined with a SAIC (group 1) versus an isolated US-guided SAIC (group 2). Randomized controlled trial; Level of evidence, 1. Patients were randomly assigned to group 1 or 2 and evaluated before and after treatment at regular time points until 12 months and also at 5 years using the Constant score (CS), the Western Ontario Rotator Cuff Index (WORC), and the Disabilities of the Arm, Shoulder and Hand (DASH). The calcification location and size and Gärtner classification were assessed on radiographs. The rotator cuff condition was evaluated with US. Results were analyzed using t tests, linear regression, and a mixed model for repeated measures. Forty-eight patients were included (mean age, 52.0 ± 7.3 years; 25 [52%] female) with a mean baseline CS of 68.7 ± 11.9. After a mean follow-up of 5.1 ± 0.5 years, the mean CS was 90 (95% CI, 83.0-95.9) in group 1 versus 87 (95% CI, 80.5-93.5) in group 2 ( P = .58). The mean improvement in the CS in group 1 was 18 (95% CI, 12.3-23.0) versus 21 (95% CI, 16.2-26.2) in group 2 ( P = .32). There was total resorption in 62% of group 1 and 73% of group 2 ( P = .45). The US evaluation of the rotator cuff condition showed no significant differences between the groups. With the mixed model for repeated measures, taking into account the baseline CS and Gärtner classification, the mean treatment effect for barbotage was 6 (95% CI, -8.9 to 21.5), but without statistical significance. Follow-up scores

Proceedings of the Space Shuttle Environmental Assessment Workshop on Stratospheric Effects

Science.gov (United States)

Potter, A. E. (Compiler)

1977-01-01

Various aspects of the potential environmental impact of space shuttle exhaust are explored. Topics include: (1) increased ultraviolet radiation levels in the biosphere due to destruction of atmospheric ozone; (2) climatic changes due to aerosol particles affecting the planetary albedo; (3) space shuttle propellants (including alternate formulations); and (4) measurement of space shuttle exhaust products.

A solar cycle of spacecraft anomalies due to internal charging

Directory of Open Access Journals (Sweden)

G. L. Wrenn

Full Text Available It is important to appreciate how the morphology of internal charging of spacecraft systems, due to penetrating electrons, differs from that of the more common surface charging, due to electrons with lower energy. A specific and recurrent anomaly on a geostationary communication satellite has been tracked for ten years so that solar cycle and seasonal dependencies can be clearly established. Concurrent measurements of sunspot number, solar wind speed and 2-day >2 MeV electron fluence are presented to highlight pertinent space weather relationships, and the importance of understanding the complex particle interaction processes involved.

Key words. Magnetospheric physics (energetic particles; trapped; solar wind – magnetosphere interactions – space plasma physics (spacecraft sheaths, wakes, charging

From the habermasian space to the new forms of the public space

Directory of Open Access Journals (Sweden)

Dinu (Stan, E.-L.

2011-01-01

Full Text Available The Habermasian theoretical perspective offers, in the literature, a detailed image of the “public sphere” concept signification. Being applied, over the years, in issues related to media theories too (globalisation, consumerism, democracy, the concept of “public sphere” has undergone radical changes due, mainly, to the emergence and convergence of electronic media. In this respect, this article does nothing more than to describe and analyze, in a realistic way, the public space, the mechanisms involved in it, as well the interplay of the public space with the private one. We could say that this dissolution of the public space is one of the major consequences of postmodernism.

Space Maintenance with an Innovative ?Tube and Loop? Space Maintainer (Nikhil Appliance)

OpenAIRE

Srivastava, Nikhil; Grover, Jyotika; Panthri, Prerna

2016-01-01

ABSTRACT Despite the best efforts in prevention, premature loss of primary teeth continues to be a common problem in pediatric dentistry, resulting in disruption of arch integrity and adversely affecting the proper alignment of permanent successors. Space maintainers (SMs) are special appliances used for maintaining space created due to premature loss of primary teeth. Band and loop SM is mostly indicated for the premature loss of single primary molar, but this appliance has a number of limit...

Space environments and their effects on space automation and robotics

Science.gov (United States)

Garrett, Henry B.

1990-01-01

Automated and robotic systems will be exposed to a variety of environmental anomalies as a result of adverse interactions with the space environment. As an example, the coupling of electrical transients into control systems, due to EMI from plasma interactions and solar array arcing, may cause spurious commands that could be difficult to detect and correct in time to prevent damage during critical operations. Spacecraft glow and space debris could introduce false imaging information into optical sensor systems. The presentation provides a brief overview of the primary environments (plasma, neutral atmosphere, magnetic and electric fields, and solid particulates) that cause such adverse interactions. The descriptions, while brief, are intended to provide a basis for the other papers presented at this conference which detail the key interactions with automated and robotic systems. Given the growing complexity and sensitivity of automated and robotic space systems, an understanding of adverse space environments will be crucial to mitigating their effects.

Intuitionistic fuzzy 2-normed space and some related concepts

International Nuclear Information System (INIS)

Mursaleen, M.; Danish Lohani, Q.M.

2009-01-01

Motivated by the notion of 2-norm due to Gaehler [Gaehler S. Lineare 2-normietre Raeume. Math Nachr 28;1965:1-43], in this paper we define the concept of intuitionistic fuzzy 2-normed space which is a generalization of the notion of intuitionistic fuzzy normed space due to Saadati and Park [Saadati R, Park JH, On the intuitionistic fuzzy topological spaces. Chaos Solitons and Fractals 2006;27:331-44]. Further we establish some topological results in this new set up.

Marangoni convection in Casson liquid flow due to an infinite disk with exponential space dependent heat source and cross-diffusion effects

Science.gov (United States)

Mahanthesh, B.; Gireesha, B. J.; Shashikumar, N. S.; Hayat, T.; Alsaedi, A.

2018-06-01

Present work aims to investigate the features of the exponential space dependent heat source (ESHS) and cross-diffusion effects in Marangoni convective heat mass transfer flow due to an infinite disk. Flow analysis is comprised with magnetohydrodynamics (MHD). The effects of Joule heating, viscous dissipation and solar radiation are also utilized. The thermal and solute field on the disk surface varies in a quadratic manner. The ordinary differential equations have been obtained by utilizing Von Kármán transformations. The resulting problem under consideration is solved numerically via Runge-Kutta-Fehlberg based shooting scheme. The effects of involved pertinent flow parameters are explored by graphical illustrations. Results point out that the ESHS effect dominates thermal dependent heat source effect on thermal boundary layer growth. The concentration and temperature distributions and their associated layer thicknesses are enhanced by Marangoni effect.

Structure resonances due to space charge in periodic focusing channels

Science.gov (United States)

Li, Chao; Jameson, R. A.

2018-02-01

The Vlasov-Poisson model is one of the most effective methods to study the space charge dominated beam evolution self-consistently in a periodic focusing channel. Since the approach to get the solution with this model is not trivial, previous studies are limited in degenerated conditions, either in smoothed channel (constant focusing) [I. Hofmann, Phys. Rev. E 57, 4713 (1998)] or in alternating gradient focusing channel with equal initial beam emittance condition in the degrees of freedom [I. Hofmann et al., Part. Accel. 13, 145 (1983); Chao Li et al., THOBA02, IPAC2016]. To establish a basis, we intentionally limit this article to the study of the pure transverse periodic focusing lattice with arbitrary initial beam condition, and the same lattice structure in both degrees of freedom, but with possibility of different focusing strengths. This will show the extension of the existing work. The full Hamiltonian is invoked for a pure transverse focusing lattice in various initial beam conditions, revealing different mode structure and additional modes beyond those of the degenerated cases. Application of the extended method to realistic lattices (including longitudinal accelerating elements) and further details will then reveal many new insights, and will be presented in later work.

Ultrasound and magnetic resonance findings and correlation in hemiplegic patients with shoulder pain.

Science.gov (United States)

Doğun, Asuman; Karabay, İlkay; Hatipoğlu, Cem; Özgirgin, Neşe

2014-01-01

The aim of this study was to evaluate the ultrasonography (US) and MRI findings in hemiplegic patients with shoulder pain and investigate the correlation between them. It is not possible for these patients to fully perform active range of motion (ROM) and stress tests, so imaging methods take center stage in diagnosis and treatment planning. A total of 68 hemiplegic patients with shoulder pain attending the inpatient rehabilitation program were included in the study. MRI and US results from the patient files were recorded. The frequency of each pathology identified by US and MRI was determined. The distribution of MRI and US findings was investigated to see whether there was a statistical difference between the correlation of MRI and US results. The mean (SD) age of the patients was 63.7 (8.3) years and the mean (SD) duration of hemiplegia was 49 (8.9) days. According to the MRI results, glenohumeral and acromioclavicular joint degeneration was found in 77.9% and 79.7% of the patients, respectively; subacromial-subdeltoid bursitis in 80.9%; fluid increase in the joint space in 41.2%; supraspinatus tendinitis in 36.8%; and supraspinatus partial rupture in 33.8%. Shoulder US findings were supraspinatus tendinitis in 54.4%, acromioclavicular joint degeneration in 26.5%, bicipital tendinitis in 20.6%, and subacromial-subdeltoid bursitis in 19.1%. There was a statistically significant difference between MRI and US findings. The results were not compatible with each other (P ≯ .05), and these findings were not consistent with each other since the kappa coefficient was under 0.40 for all these results. Although US is recommended as the first method in determining shoulder pathologies in hemiplegic patients, we suggest that MRI should be used as the first choice in hemiplegic patients with shoulder pain. MRI and US findings were not consistent, and US is dependent on the experience of the operator. MRI should be the first choice in cases where the diagnosis will affect

Biotechnology opportunities on Space Station

Science.gov (United States)

Deming, Jess; Henderson, Keith; Phillips, Robert W.; Dickey, Bernistine; Grounds, Phyllis

1987-01-01

Biotechnology applications which could be implemented on the Space Station are examined. The advances possible in biotechnology due to the favorable microgravity environment are discussed. The objectives of the Space Station Life Sciences Program are: (1) the study of human diseases, (2) biopolymer processing, and (3) the development of cryoprocessing and cryopreservation methods. The use of the microgravity environment for crystal growth, cell culturing, and the separation of biological materials is considered. The proposed Space Station research could provide benefits to the fields of medicine, pharmaceuticals, genetics, agriculture, and industrial waste management.

Strut Attachment System for In-Space Robotic Assembly, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — The size of space systems is currently limited to payload envelopes of existing launch vehicles. Due to this and the customized nature of satellites, existing space...

Strut Attachment System for In-Space Robotic Assembly, Phase II

Data.gov (United States)

National Aeronautics and Space Administration — The size of space systems is currently limited to payload envelopes of existing launch vehicles. Due to this and the customized nature of satellites, existing space...

A Milestone in Commercial Space Weather: USTAR Center for Space Weather

Science.gov (United States)

Tobiska, W.; Schunk, R. W.; Sojka, J. J.; Thompson, D. C.; Scherliess, L.; Zhu, L.; Gardner, L. C.

2009-12-01

As of 2009, Utah State University (USU) hosts a new organization to develop commercial space weather applications using funding that has been provided by the State of Utah’s Utah Science Technology and Research (USTAR) initiative. The USTAR Center for Space Weather (UCSW) is located on the USU campus in Logan, Utah and is developing innovative applications for mitigating adverse space weather effects in technological systems. Space weather’s effects upon the near-Earth environment are due to dynamic changes in the Sun’s photons, particles, and fields. Of the space environment domains that are affected by space weather, the ionosphere is the key region that affects communication and navigation systems. The UCSW has developed products for users of systems that are affected by space weather-driven ionospheric changes. For example, on September 1, 2009 USCW released, in conjunction with Space Environment Technologies, the world’s first real-time space weather via an iPhone app. Space WX displays the real-time, current global ionosphere total electron content along with its space weather drivers; it is available through the Apple iTunes store and is used around the planet. The Global Assimilation of Ionospheric Measurements (GAIM) system is now being run operationally in real-time at UCSW with the continuous ingestion of hundreds of global data streams to dramatically improve the ionosphere’s characterization. We discuss not only funding and technical advances that have led to current products but also describe the direction for UCSW that includes partnering opportunities for moving commercial space weather into fully automated specification and forecasting over the next half decade.

Instability of flat space at finite temperature

International Nuclear Information System (INIS)

Gross, D.J.; Perry, M.J.; Yaffe, L.G.

1982-01-01

The instabilities of quantum gravity are investigated using the path-integral formulation of Einstein's theory. A brief review is given of the classical gravitational instabilities, as well as the stability of flat space. The Euclidean path-integral representation of the partition function is employed to discuss the instability of flat space at finite temperature. Semiclassical, or saddle-point, approximations are utilized. We show how the Jeans instability arises as a tachyon in the graviton propagator when small perturbations about hot flat space are considered. The effect due to the Schwarzschild instanton is studied. The small fluctuations about this instanton are analyzed and a negative mode is discovered. This produces, in the semiclassical approximation, an imaginary part of the free energy. This is interpreted as being due to the metastability of hot flat space to nucleate black holes. These then evolve by evaporation or by accretion of thermal gravitons, leading to the instability of hot flat space. The nucleation rate of black holes is calculated as a function of temperature

The role of chemical engineering in space manufacturing

Science.gov (United States)

Waldron, R. D.; Criswell, D. R.; Erstfeld, T. E.

1979-01-01

A survey of factors involved in space manufacturing is presented. It is shown that it will be more economical to obtain the necessary raw materials from the moon than from earth due to earth's greater gravity and atmosphere. Discussion covers what resources can be mined and recovered from the moon and what ranges of industrial feedstock can be provided from lunar materials, noting that metallurgy will be different in space due to the lack of key elements such as H, C, Na, Cl, etc. Also covered are chemical plant design, space environmental factors such as vacuum and zero gravity, recycling requirments, reagent and equipment mass, and unit operations such as materials handling and phase separation. It is concluded that a pilot plant in space could be an economic boon to mankind.

Noncommutative Phase Spaces by Coadjoint Orbits Method

Directory of Open Access Journals (Sweden)

Ancille Ngendakumana

2011-12-01

Full Text Available We introduce noncommutative phase spaces by minimal couplings (usual one, dual one and their mixing. We then realize some of them as coadjoint orbits of the anisotropic Newton-Hooke groups in two- and three-dimensional spaces. Through these constructions the positions and the momenta of the phase spaces do not commute due to the presence of a magnetic field and a dual magnetic field.

Dual Vector Spaces and Physical Singularities

Science.gov (United States)

Rowlands, Peter

Though we often refer to 3-D vector space as constructed from points, there is no mechanism from within its definition for doing this. In particular, space, on its own, cannot accommodate the singularities that we call fundamental particles. This requires a commutative combination of space as we know it with another 3-D vector space, which is dual to the first (in a physical sense). The combination of the two spaces generates a nilpotent quantum mechanics/quantum field theory, which incorporates exact supersymmetry and ultimately removes the anomalies due to self-interaction. Among the many natural consequences of the dual space formalism are half-integral spin for fermions, zitterbewegung, Berry phase and a zero norm Berwald-Moor metric for fermionic states.

Space Mission Human Reliability Analysis (HRA) Project

Science.gov (United States)

Boyer, Roger

2014-01-01

The purpose of the Space Mission Human Reliability Analysis (HRA) Project is to extend current ground-based HRA risk prediction techniques to a long-duration, space-based tool. Ground-based HRA methodology has been shown to be a reasonable tool for short-duration space missions, such as Space Shuttle and lunar fly-bys. However, longer-duration deep-space missions, such as asteroid and Mars missions, will require the crew to be in space for as long as 400 to 900 day missions with periods of extended autonomy and self-sufficiency. Current indications show higher risk due to fatigue, physiological effects due to extended low gravity environments, and others, may impact HRA predictions. For this project, Safety & Mission Assurance (S&MA) will work with Human Health & Performance (HH&P) to establish what is currently used to assess human reliabiilty for human space programs, identify human performance factors that may be sensitive to long duration space flight, collect available historical data, and update current tools to account for performance shaping factors believed to be important to such missions. This effort will also contribute data to the Human Performance Data Repository and influence the Space Human Factors Engineering research risks and gaps (part of the HRP Program). An accurate risk predictor mitigates Loss of Crew (LOC) and Loss of Mission (LOM).The end result will be an updated HRA model that can effectively predict risk on long-duration missions.

Landau damping due to tune spreads in betatron amplitude and momentum

International Nuclear Information System (INIS)

Lee, S.Y.; Tran, P.; Weng, W.T.

1989-01-01

Due to the large space charge transverse impedance in a low energy synchrotron, the coherent tune shift causes the Landau damping to be ineffective in damping the transverse coherent motion. We analyze the effect of Landau damping that is caused by the tune spreads of the betatron amplitude (space charge and/or octupole) and momentum. We find that the Landau damping becomes more significant in our two dimensional analysis. 5 refs

Equilibrium phase-space distributions and space charge limits in linacs

International Nuclear Information System (INIS)

Lysenko, W.P.

1977-10-01

Limits on beam current and emittance in proton and heavy ion linear accelerators resulting from space charge forces are calculated. The method involves determining equilibrium distributions in phase space using a continuous focusing, no acceleration, model in two degrees of freedom using the coordinates r and z. A nonlinear Poisson equation must be solved numerically. This procedure is a matching between the longitudinal and transverse directions to minimize the effect of longitudinal-transverse coupling which is believed to be the main problem in emittance growth due to space charge in linacs. Limits on the Clinton P. Anderson Meson Physics Facility (LAMPF) accelerator performance are calculated as an example. The beam physics is described by a few space charge parameters so that accelerators with different physical parameters can be compared in a natural way. The main result of this parameter study is that the requirement of a high-intensity beam is best fulfilled with a low-frequency accelerator whereas the requirement of a high-brightness beam is best fulfilled with a high-frequency accelerator

A Dynamic Model for Roll Motion of Ships due to Flooding

DEFF Research Database (Denmark)

Xia, Jinzhu; Jensen, Jørgen Juncher; Pedersen, Preben Terndrup

1999-01-01

Because of the large undivided deck spaces, RoRo vessels are often sensitive to rapid capsizing due to sudden ingress of water. Following a high-energy damage, a rapidly increasing heeling moment is induced by the ingress of water, which generates a roll motion of the damaged vessel. If, addition......Because of the large undivided deck spaces, RoRo vessels are often sensitive to rapid capsizing due to sudden ingress of water. Following a high-energy damage, a rapidly increasing heeling moment is induced by the ingress of water, which generates a roll motion of the damaged vessel. If......, additionally, the car deck is flooded and/or the cargo is shifted, the heeling moment may exceed the residual restoring moment, which results in capsizing....

A Reparametrization Approach for Dynamic Space-Time Models

OpenAIRE

Lee, Hyeyoung; Ghosh, Sujit K.

2008-01-01

Researchers in diverse areas such as environmental and health sciences are increasingly working with data collected across space and time. The space-time processes that are generally used in practice are often complicated in the sense that the auto-dependence structure across space and time is non-trivial, often non-separable and non-stationary in space and time. Moreover, the dimension of such data sets across both space and time can be very large leading to computational difficulties due to...

Dynamic Three-Dimensional Shoulder Mri during Active Motion for Investigation of Rotator Cuff Diseases.

Directory of Open Access Journals (Sweden)

Christine Tempelaere

Full Text Available MRI is the standard methodology in diagnosis of rotator cuff diseases. However, many patients continue to have pain despite treatment, and MRI of a static unloaded shoulder seems insufficient for best diagnosis and treatment. This study evaluated if Dynamic MRI provides novel kinematic data that can be used to improve the understanding, diagnosis and best treatment of rotator cuff diseases.Dynamic MRI provided real-time 3D image series and was used to measure changes in the width of subacromial space, superior-inferior translation and anterior-posterior translation of the humeral head relative to the glenoid during active abduction. These measures were investigated for consistency with the rotator cuff diseases classifications from standard MRI.The study included: 4 shoulders with massive rotator cuff tears, 5 shoulders with an isolated full-thickness supraspinatus tear, 5 shoulders with tendinopathy and 6 normal shoulders. A change in the width of subacromial space greater than 4mm differentiated between rotator cuff diseases with tendon tears (massive cuff tears and supraspinatus tear and without tears (tendinopathy (p = 0.012. The range of the superior-inferior translation was higher in the massive cuff tears group (6.4mm than in normals (3.4mm (p = 0.02. The range of the anterior-posterior translation was higher in the massive cuff tears (9.2 mm and supraspinatus tear (9.3 mm shoulders compared to normals (3.5mm and tendinopathy (4.8mm shoulders (p = 0.05.The Dynamic MRI enabled a novel measure; 'Looseness', i.e. the translation of the humeral head on the glenoid during an abduction cycle. Looseness was better able at differentiating different forms of rotator cuff disease than a simple static measure of relative glenohumeral position.

Measuring space radiation shielding effectiveness

OpenAIRE

Bahadori Amir; Semones Edward; Ewert Michael; Broyan James; Walker Steven

2017-01-01

Passive radiation shielding is one strategy to mitigate the problem of space radiation exposure. While space vehicles are constructed largely of aluminum, polyethylene has been demonstrated to have superior shielding characteristics for both galactic cosmic rays and solar particle events due to the high hydrogen content. A method to calculate the shielding effectiveness of a material relative to reference material from Bragg peak measurements performed using energetic heavy charged particles ...

Three-dimensional volume rendering of tibiofibular joint space and quantitative analysis of change in volume due to tibiofibular syndesmosis diastases

International Nuclear Information System (INIS)

Taser, F.; Shafiq, Q.; Ebraheim, N.A.

2006-01-01

The diagnosis of ankle syndesmosis injuries is made by various imaging techniques. The present study was undertaken to examine whether the three-dimensional reconstruction of axial CT images and calculation of the volume of tibiofibular joint space enhances the sensitivity of diastases diagnoses or not. Six adult cadaveric ankle specimens were used for spiral CT-scan assessment of tibiofibular syndesmosis. After the specimens were dissected, external fixation was performed and diastases of 1, 2, and 3 mm was simulated by a precalibrated device. Helical CT scans were obtained with 1.0-mm slice thickness. The data was transferred to the computer software AcquariusNET. Then the contours of the tibiofibular syndesmosis joint space were outlined on each axial CT slice and the collection of these slices were stacked using the computer software AutoCAD 2005, according to the spatial arrangement and geometrical coordinates between each slice, to produce a three-dimensional reconstruction of the joint space. The area of each slice and the volume of the entire tibiofibular joint space were calculated. The tibiofibular joint space at the 10th-mm slice level was also measured on axial CT scan images at normal, 1, 2 and 3-mm joint space diastases. The three-dimensional volume-rendering of the tibiofibular syndesmosis joint space from the spiral CT data demonstrated the shape of the joint space and has been found to be a sensitive method for calculating joint space volume. We found that, from normal to 1 mm, a 1-mm diastasis increases approximately 43% of the joint space volume, while from 1 to 3 mm, there is about a 20% increase for each 1-mm increase. Volume calculation using this method can be performed in cases of syndesmotic instability after ankle injuries and for preoperative and postoperative evaluation of the integrity of the tibiofibular syndesmosis. (orig.)

Phase-space networks of geometrically frustrated systems.

Science.gov (United States)

Han, Yilong

2009-11-01

We illustrate a network approach to the phase-space study by using two geometrical frustration models: antiferromagnet on triangular lattice and square ice. Their highly degenerated ground states are mapped as discrete networks such that the quantitative network analysis can be applied to phase-space studies. The resulting phase spaces share some comon features and establish a class of complex networks with unique Gaussian spectral densities. Although phase-space networks are heterogeneously connected, the systems are still ergodic due to the random Poisson processes. This network approach can be generalized to phase spaces of some other complex systems.

Static deformation due to a long buried dip-slip fault in an isotropic

Indian Academy of Sciences (India)

Closed-form analytical expressions for the displacements and the stresses at any point of a two-phase medium consisting of a homogeneous, isotropic, perfectly elastic half-space in welded contact with a homogeneous, orthotropic, perfectly elastic half-space due to a dip-slip fault of finite width located at an arbitrary ...

Super Global Projects and Environmentally Friendly Technologies Used in Space Exploration: Realities and Prospects of the Space Age

Directory of Open Access Journals (Sweden)

Sergey Krichevsky

2018-02-01

Full Text Available The 60th anniversary of the Space Age is an important intermediate finishing point on the way of a man and the whole humanity to space. Along with the outstanding achievements, there are a number of challenges and contradictions in space exploration due to the aggravation of the global crisis on Earth, low efficiency and the backlog of space research in the transition to a new technology based reality and clean technologies. Both the international astronautics and the space exploration area nowadays face difficulties in choosing a new paradigm and a development strategy that is becoming even more complicated due to the current unstable and turbulent situation on Earth. The article reveals the optimistic scenario of further space exploration, as well as the methodological and practical aspects of new projects and technologies. The periodization of the Space Age history has been conducted. It has been also proposed a new classification of the “space” phenomenon due to concretizing the concept of “global” in the form of a three-scale structure encompassing the following levels: 1 planetary global; 2 super global; 3 universally global. The notion of “super global space exploration project” has been introduced. The concept of further space exploration is proposed, which includes four interrelated super global projects:1 Earth Protection System from Asteroid and Comet Threat; 2 Moon Exploration; 3 Mars Exploration; 4 Cosmic Humanity. Since the humanity is embarking on the practical implementation of these super global projects, it is urgent to make a transition towards a new technology based order, as well as up-to-date technologies. A couple of ecological projects and space exploration technologies of the 20th and 21st centuries have been exemplified and analyzed. It has been also worked out the list of new environmentally friendly space technologies and projects. The research makes an emphasis upon a great potential of clean and green

MRI of atraumatic sports injuries of the shoulder

International Nuclear Information System (INIS)

Sasaki, Taisuke; Saito, Yoko; Sasaki, Yukio; Yodono, Hiraku; Takekawa, Shoichi; Nakamura, Ryujiro; Harata, Seiko

1992-01-01

MRI of operatively or arthroscopically proven atraumatic sports injuries of 12 shoulders were reviewed retrospectively. Although it is difficult to diagnose the lesions localised at the superior glenoid labrum and to decide whether rotator interval is injured or not by MRI, MRI could detect thickening of subacromial bursae or rotator cuff injuries due to impingement syndrome and glenoid labrum injuries, such as Bankart lesion. On our limited experience, MRI was more valuable examination than arthrography and CT arthrography. MRI is a useful modality for screening or preoperative evaluation of atraumatic sports injuries of the shoulder. (author)

Biotechnological experiments in space flights on board of space stations

Science.gov (United States)

Nechitailo, Galina S.

2012-07-01

Space flight conditions are stressful for any plant and cause structural-functional transition due to mobiliation of adaptivity. In space flight experiments with pea tissue, wheat and arabidopsis we found anatomical-morphological transformations and biochemistry of plants. In following experiments, tissue of stevia (Stevia rebaudiana), potato (Solanum tuberosum), callus culture and culture and bulbs of suffron (Crocus sativus), callus culture of ginseng (Panax ginseng) were investigated. Experiments with stevia carried out in special chambers. The duration of experiment was 8-14 days. Board lamp was used for illumination of the plants. After experiment the plants grew in the same chamber and after 50 days the plants were moved into artificial ionexchange soil. The biochemical analysis of plants was done. The total concentration of glycozides and ratio of stevioside and rebauside were found different in space and ground plants. In following generations of stevia after flight the total concentration of stevioside and rebauside remains higher than in ground plants. Experiments with callus culture of suffron carried out in tubes. Duration of space flight experiment was 8-167 days. Board lamp was used for illumination of the plants. We found picrocitina pigment in the space plants but not in ground plants. Tissue culture of ginseng was grown in special container in thermostate under stable temperature of 22 ± 0,5 C. Duration of space experiment was from 8 to 167 days. Biological activity of space flight culutre was in 5 times higher than the ground culture. This difference was observed after recultivation of space flight samples on Earth during year after flight. Callus tissue of potato was grown in tubes in thermostate under stable temperature of 22 ± 0,5 C. Duration of space experiment was from 8 to 14 days. Concentration of regenerates in flight samples was in 5 times higher than in ground samples. The space flight experiments show, that microgravity and other

Modelling of electric tree progression due to space charge modified fields

International Nuclear Information System (INIS)

Seralathan, K E; Mahajan, A; Gupta, Nandini

2008-01-01

Tree initiation and growth require localized field enhancement that results in material erosion and formation of tree channels. Tree progression is linked to partial discharges within the tree tubules, characterized by recurrent periods of activity followed by quiescent states. Charge builds up across the non-conducting tree channels during the inactive regime, and discharge follows. In this work, the role of the space charge modified field during the non-discharging regime in deciding the site of subsequent discharges and thereby shaping tree structures is studied. A simple stochastic model was developed, in order to understand the respective effects of charges trapped on the walls of tree tubules, at channel tips, or in the volume of the dielectric. While some charge distributions are seen to arrest tree growth, others encourage axial growth towards the other electrode, and some aid in producing bushy trees clustered around the needle tip. The effect of carbon deposition within tree channels, making them effectively conducting, was also investigated. The insights gained from the simulations were successfully used to explain tree growth in the laboratory under high- and low-field conditions

Natural convection in an adiabatic vertical channel due to a dissipated heat element

International Nuclear Information System (INIS)

Ramos, M.A.M.S.

1986-01-01

An experimental study was perfomed on natural convection heat transfer to air in a vertical channel due to an isothermal heated element attached in one of the walls of the channel. The heated element dissipates heat due to the Joule effect. To determine the heat transfer coefficient, it is necessary to evaluate the heat transferred to air by natural convenction alone. Hence, the heat lost by the element due to conduction and radiation is evaluated in order to correct the measured heat transfer. The natural-convenction heat transfer coefficient is a function of the following parameters: the temperature difference between the element and the ambient air, the position of the element in the channel, and the channel spacing. An optimal value of the channel spacing, when the heat transfer coefficient attains its maximum value, was observed for each of the temperature difference investigated. These maximum values may be up to 25% higher than the value for the case of infinite spacing. Comparisons are made with results available in the literature for similar configurations, and the values found in this work are higher. (author) [pt

Emerging Space Powers The New Space Programs of Asia, the Middle East, and South America

CERN Document Server

Harvey, Brian; Pirard, Théo

2010-01-01

This work introduces the important emerging space powers of the world. Brian Harvey describes the origins of the Japanese space program, from rocket designs based on WW II German U-boats to tiny solid fuel 'pencil' rockets, which led to the launch of the first Japanese satellite in 1970. The next two chapters relate how Japan expanded its space program, developing small satellites into astronomical observatories and sending missions to the Moon, Mars, comet Halley, and asteroids. Chapter 4 describes how India's Vikram Sarabhai developed a sounding rocket program in the 1960s. The following chapter describes the expansion of the Indian space program. Chapter 6 relates how the Indian space program is looking ahead to the success of the moon probe Chandrayan, due to launch in 2008, and its first manned launching in 2014. Chapters 7, 8, and 9 demonstrate how, in Iran, communications and remote sensing drive space technology. Chapter 10 outlines Brazil's road to space, begun in the mid-1960's with the launch of th...

Aviation or space policy: New challenges for the insurance sector to private human access to space

Science.gov (United States)

van Oijhuizen Galhego Rosa, Ana Cristina

2013-12-01

The phenomenon of private human access to space has introduced a new set of problems in the insurance sector. Orbital and suborbital space transportation will surely be unique commercial services for this new market. Discussions are under way regarding space insurance, in order to establish whether this new market ought to be regulated by aviation or space law. Alongside new definitions, infrastructures, legal frameworks and liability insurances, the insurance sector has also been introducing a new approach. In this paper, I aim to analyse some of the possibilities of new premiums, capacities, and policies (under aviation or space insurance rules), as well as the new insurance products related to vehicles, passengers and third party liability. This paper claims that a change toward new insurance regimes is crucial, due to the current stage in development of space tourism and the urgency to adapt insurance rules to support future development in this area.

Retabulation of space group extinctions for electron diffraction

International Nuclear Information System (INIS)

Goodman, P.; Tanaka, M.

1989-01-01

The space group tables previously published by one of the authors and others are here presented in a revised and compacted form designed to make for compatability with existing tables for X-ray diffraction. 136 of the 230 space groups are subject to dynamic extinctions due to glide planes and screw axes, and the observables from these space groups in specific settings are tabulated. Tabs

Charting a Path Toward a Sustainable ROK Space Program

Science.gov (United States)

2016-12-01

technological competitiveness in niche markets.  While the ROK has invested in certain, independent military space capabilities, it will be best served－in...through rich research in space like Israel has put in space activities, the ROK cannot reach its targeted point. Moreover, these efforts cannot achieve...human capital promotion. But the ROK still has opportunities in space development due to the strength of its technological competitiveness in niche

The seesaw space, a vector space to identify and characterize large-scale structures at 1 AU

Science.gov (United States)

Lara, A.; Niembro, T.

2017-12-01

We introduce the seesaw space, an orthonormal space formed by the local and the global fluctuations of any of the four basic solar parameters: velocity, density, magnetic field and temperature at any heliospheric distance. The fluctuations compare the standard deviation of a moving average of three hours against the running average of the parameter in a month (consider as the local fluctuations) and in a year (global fluctuations) We created this new vectorial spaces to identify the arrival of transients to any spacecraft without the need of an observer. We applied our method to the one-minute resolution data of WIND spacecraft from 1996 to 2016. To study the behavior of the seesaw norms in terms of the solar cycle, we computed annual histograms and fixed piecewise functions formed by two log-normal distributions and observed that one of the distributions is due to large-scale structures while the other to the ambient solar wind. The norm values in which the piecewise functions change vary in terms of the solar cycle. We compared the seesaw norms of each of the basic parameters due to the arrival of coronal mass ejections, co-rotating interaction regions and sector boundaries reported in literature. High seesaw norms are due to large-scale structures. We found three critical values of the norms that can be used to determined the arrival of coronal mass ejections. We present as well general comparisons of the norms during the two maxima and the minimum solar cycle periods and the differences of the norms due to large-scale structures depending on each period.

Field collapse due to band-tail charge in amorphous silicon solar cells

Energy Technology Data Exchange (ETDEWEB)

Wang, Qi; Crandall, R.S. [National Renewable Energy Lab., Golden, CO (United States); Schiff, E.A. [Syracuse Univ., NY (United States)

1996-05-01

It is common for the fill factor to decrease with increasing illumination intensity in hydrogenated amorphous silicon solar cells. This is especially critical for thicker solar cells, because the decrease is more severe than in thinner cells. Usually, the fill factor under uniformly absorbed red light changes much more than under strongly absorbed blue light. The cause of this is usually assumed to arise from space charge trapped in deep defect states. The authors model this behavior of solar cells using the Analysis of Microelectronic and Photonic Structures (AMPS) simulation program. The simulation shows that the decrease in fill factor is caused by photogenerated space charge trapped in the band-tail states rather than in defects. This charge screens the applied field, reducing the internal field. Owing to its lower drift mobility, the space charge due to holes exceeds that due to electrons and is the main cause of the field screening. The space charge in midgap states is small compared with that in the tails and can be ignored under normal solar-cell operating conditions. Experimentally, the authors measured the photocapacitance as a means to probe the collapsed field. They also explored the light intensity dependence of photocapacitance and explain the decrease of FF with the increasing light intensity.

In-Space Manufacturing Baseline Property Development

Science.gov (United States)

Stockman, Tom; Schneider, Judith; Prater, Tracie; Bean, Quincy; Werkheiser, Nicki

2016-01-01

The In-Space Manufacturing (ISM) project at NASA Marshall Space Flight Center currently operates a 3D FDM (fused deposition modeling) printer onboard the International Space Station. In order to enable utilization of this capability by designer, the project needs to establish characteristic material properties for materials produced using the process. This is difficult for additive manufacturing since standards and specifications do not yet exist for these technologies. Due to availability of crew time, there are limitations to the sample size which in turn limits the application of the traditional design allowables approaches to develop a materials property database for designers. In this study, various approaches to development of material databases were evaluated for use by designers of space systems who wish to leverage in-space manufacturing capabilities. This study focuses on alternative statistical techniques for baseline property development to support in-space manufacturing.

AMS gets lift on space shuttle Discovery

CERN Multimedia

2009-01-01

AMS-02, the CERN-recognized experiment that will seek dark matter, missing matter and antimatter in Space aboard the International Space Station (ISS), has recently got the green light to be part of the STS-134 NASA mission in 2010. Installation of AMS detectors in the Prévessin experiment hall.In a recent press release, NASA announced that the last or last-but-one mission of the Space Shuttle programme would be the one that will deliver AMS, the Alpha Magnetic Spectrometer, to the International Space Station. The Space Shuttle Discovery is due to lift off in July 2010 from Kennedy Space Center and its mission will include the installation of AMS to the exterior of the space station, using both the shuttle and station arms. "It wasn’t easy to get a lift on the Space Shuttle from the Bush administration," says professor Samuel Ting, spokesperson of the experiment, "since during his administration all the funds for space research w...

Emittance growth due to negative-mass instability above transition

International Nuclear Information System (INIS)

Ng, King-Yuen.

1994-08-01

Due to space-charge effect, there is a growth of bunch emittance across transition as a result of negative-mass instability. The models of growth at cutoff frequency and growth from high-frequency Schottky noise are reviewed. The difficulties of performing reliable simulations are discussed. An intuitive self-bunching model for estimating emittance growth is presented

Phase-space holes due to electron and ion beams accelerated by a current-driven potential ramp

Directory of Open Access Journals (Sweden)

M. V. Goldman

2003-01-01

Full Text Available One-dimensional open-boundary simulations have been carried out in a current-carrying plasma seeded with a neutral density depression and with no initial electric field. These simulations show the development of a variety of nonlinear localized electric field structures: double layers (unipolar localized fields, fast electron phase-space holes (bipolar fields moving in the direction of electrons accelerated by the double layer and trains of slow alternating electron and ion phase-space holes (wave-like fields moving in the direction of ions accelerated by the double layer. The principal new result in this paper is to show by means of a linear stability analysis that the slow-moving trains of electron and ion holes are likely to be the result of saturation via trapping of a kinetic-Buneman instability driven by the interaction of accelerated ions with unaccelerated electrons.

Effect of Battlefield Acupuncture and Physical Therapy Versus Physical Therapy Alone After Shoulder Surgery

Science.gov (United States)

2018-05-14

Opioid Use; Pain, Postoperative; SLAP Lesion; Bankart Lesion; Subacromial Impingement Syndrome; Rotator Cuff Tear; Glenohumeral Dislocation; Glenohumeral Subluxation; Hill Sach Lesion; Bony Bankart Lesion; Acromioclavicular Separation

Nonlinear space charge effect of bunched beam in linac

International Nuclear Information System (INIS)

Chen Yinbao

1992-02-01

The nonlinear space charge effect due to the nonuniform particle density distribution in bunched beam of a linac is discussed. The formulae of nonlinear space charge effect and nonlinear focusing forces were derived for the bunched beam with Kapchinskij-Vladimirskij (K-V) distribution, waterbag (WB) distribution, parabolic (PA) distribution, and Gauss (GA) distribution in both of the space charge disk model and space charge cylinder model in the waveguide of a linac

2-D deformation of two welded half-spaces due to a blind dip-slip fault

Indian Academy of Sciences (India)

The solution of two-dimensional problem of an interface breaking long inclined dip-slip fault in two welded half-spaces is well known.The purpose of this note is to obtain the corresponding solution for a blind fault.The solution is valid for arbitrary values of the fault-depth and the dip angle.Graphs showing the variation of the ...

Extracorporeal shock wave treatment for shoulder calcific tendonitis: a systematic review

International Nuclear Information System (INIS)

Mouzopoulos, G.; Tzurbakis, M.; Stamatakos, M.; Mouzopoulos, D.

2007-01-01

The treatment of patients with calcific tendonitis is typically conservative, including physical therapy, iontophoresis, deep friction, local or systemic application of noninflammatory drugs, needle irrigation-aspiration of calcium deposit, and subacromial bursal steroid injection. If the pain becomes chronic or intermittent after several months of conservative treatment, arthroscopic and open procedures are available to curette the calcium deposit, and additional subacromial decompression can be performed if necessary. As an alternative, minimally invasive extracorporeal shock wave therapy (ESWT) has been postulated to be an effective treatment option for treating calcific tendinitis of the shoulder, before surgery. Herein we discuss the indications, mechanism of therapeutic effect, efficacy of treatment, and complications after ESWT application. (orig.)

Phase space diffusion in turbulent plasmas

DEFF Research Database (Denmark)

Pécseli, Hans

1990-01-01

. The second type are particles introduced at a prescribed phase space position at a certain time and which then self-consistently participate in the phase space dynamics of the turbulence. The latter "active" type of particles can be subject to an effective frictional force due to radiation of plasma waves....... In terms of these test particle types, two basically different problems can be formulated. One deals with the diffusion of a particle with respect to its point of release in phase space. Alternatively the relative diffusion between many, or just two, particles can be analyzed. Analytical expressions...

Evaluation of the effects of subgingival injection of Simvastatin on space re-opening after orthodontic space closure in adults.

Science.gov (United States)

Jahanbin, Arezoo; Abtahi, Mostafa; Namdar, Parastoo; Heravi, Farzin; Sadeghi, Fatemeh; Arab, Hamidreza; Shafaee, Hooman

2016-01-01

Background. This clinical trial evaluated the effect of Simvastatin on space re-opening after orthodontic space closure and its effect on the gingival index (GI) and clinical attachment loss (CAL). Methods. 16 females, 25-40 years old, with spaces between anterior mandibular teeth due to chronic periodontitis were participated in this study. The patients were randomly divided into control and experimental groups. In the experimental group, 1.2% Simvastatin gel and in the control group, 0.9% sodium chloride as a placebo was injected into the pocket depth of the six anterior teeth. The amount of space reopening, GI and CAL were measured. Results. No serious complications were observed during interventions and follow-up periods. Space re-opening was significantly reduced in patients receiving Simvastatin (P space re-opening after orthodontic space closure in human anterior teeth.

Space Maintenance with an Innovative "Tube and Loop" Space Maintainer (Nikhil Appliance).

Science.gov (United States)

Srivastava, Nikhil; Grover, Jyotika; Panthri, Prerna

2016-01-01

Despite the best efforts in prevention, premature loss of primary teeth continues to be a common problem in pediatric dentistry, resulting in disruption of arch integrity and adversely affecting the proper alignment of permanent successors. Space maintainers (SMs) are special appliances used for maintaining space created due to premature loss of primary teeth. Band and loop SM is mostly indicated for the premature loss of single primary molar, but this appliance has a number of limitations both for operators and for patients. Presented in this article is an innovative "Tube and Loop" SM (Nikhil appliance) which offers several advantages over the conventional band and loop SM. It is not only easy and quick to fabricate but can also be completed in a single sitting and cumbersome steps like impression making and laboratory procedures namely soldering are eliminated. How to cite this article: Srivastava N, Grover J, Panthri P. Space Maintenance with an Innovative "Tube and Loop" Space Maintainer (Nikhil Appliance). Int J Clin Pediatr Dent 2016;9(1):86-89.

46 CFR 32.40-35 - Hospital space-T/ALL.

Science.gov (United States)

2010-10-01

... 46 Shipping 1 2010-10-01 2010-10-01 false Hospital space-T/ALL. 32.40-35 Section 32.40-35 Shipping... REQUIREMENTS Accommodations for Officers and Crew § 32.40-35 Hospital space—T/ALL. (a) Each vessel which in the... crew of 12 or more, must be provided with a hospital space. This space must be situated with due regard...

The effect of a rotator cuff tear and its size on three-dimensional shoulder motion.

Science.gov (United States)

Kolk, Arjen; Henseler, Jan Ferdinand; de Witte, Pieter Bas; van Zwet, Erik W; van der Zwaal, Peer; Visser, Cornelis P J; Nagels, Jochem; Nelissen, Rob G H H; de Groot, Jurriaan H

2017-06-01

Rotator cuff-disease is associated with changes in kinematics, but the effect of a rotator cuff-tear and its size on shoulder kinematics is still unknown in-vivo. In this cross-sectional study, glenohumeral and scapulothoracic kinematics of the affected shoulder were evaluated using electromagnetic motion analysis in 109 patients with 1) subacromial pain syndrome (n=34), 2) an isolated supraspinatus tear (n=21), and 3) a massive rotator cuff tear involving the supraspinatus and infraspinatus (n=54). Mixed models were applied for the comparisons of shoulder kinematics between the three groups during abduction and forward flexion. In the massive rotator cuff-tear group, we found reduced glenohumeral elevation compared to the subacromial pain syndrome (16°, 95% CI [10.5, 21.2], protator cuff tears coincides with an increase in scapulothoracic lateral rotation compared to subacromial pain syndrome (11°, 95% CI [6.5, 15.2], protator cuff-tear group had substantially less glenohumeral elevation and more scapulothoracic lateral rotation compared to the other groups. These observations suggest that the infraspinatus is essential to preserve glenohumeral elevation in the presence of a supraspinatus tear. Shoulder kinematics are associated with rotator cuff-tear size and may have diagnostic potential. Copyright © 2017 Elsevier Ltd. All rights reserved.

Klystron - Space-charge limited flow, guns, Perveance

International Nuclear Information System (INIS)

Isagawa, S.

1999-01-01

This paper treats Thermionic emission, Cathode as an e - emitter, Space-charge limited effect and 3/2 power law, Perveance, Beam spread due to space charge, Pierce guns, Magnetically immersed guns, Method of gun design including simulations, and Examples, mainly treating E3786, which attendees will operate above 1 MW-CW in a practical exercise course at KEK. (author). 74 refs

Fixed point theory in metric type spaces

CERN Document Server

Agarwal, Ravi P; O’Regan, Donal; Roldán-López-de-Hierro, Antonio Francisco

2015-01-01

Written by a team of leading experts in the field, this volume presents a self-contained account of the theory, techniques and results in metric type spaces (in particular in G-metric spaces); that is, the text approaches this important area of fixed point analysis beginning from the basic ideas of metric space topology. The text is structured so that it leads the reader from preliminaries and historical notes on metric spaces (in particular G-metric spaces) and on mappings, to Banach type contraction theorems in metric type spaces, fixed point theory in partially ordered G-metric spaces, fixed point theory for expansive mappings in metric type spaces, generalizations, present results and techniques in a very general abstract setting and framework. Fixed point theory is one of the major research areas in nonlinear analysis. This is partly due to the fact that in many real world problems fixed point theory is the basic mathematical tool used to establish the existence of solutions to problems which arise natur...

Women in Space

Science.gov (United States)

Mukai, Chiaki

Since 1963 women have successfully flown and worked in space so much so that having a female aboard the shuttle, on Soyuz or on the International Space Station is considered commonplace. We do know that women have historically been virturally equal in capabilities and performance with their male counterparts. For example, there have been superb shuttle pilots, shuttle commanders, EVA participants as well as mission specialists and payload specialists. Thus, gender is not an issue within the ranks, rather a simple fact. In addition, there is a positive psychological factor that has been noted in that a mixed crew seems to have better intercommunications dynamics. JAXA has conducted the experiments on 7 subjects on bone mineral density in short duration of space flight and noticed a slight decrease in that density in both male and female. Lean body mass was also examined and found to be reduced by 3.0 % on average. There was no significant difference between male and female subjects in short duration of space flight. Unfortunately, only 1 of the 7 subjects was a woman. In fact, only 48 women have flown in total, some more than once, and science is still discovering the effects of the space experience. This is due to the limited exposure on orbit and in microgravity and the limited number of potential subjects. Time in space is beginning to increase with the continued progress of the ISS, thereby creating a demand for more knowledge on what effects long term exposure will have on the female of the species. The presentation will address these and other concerns involved with women in space from the perspective of a female scientist and an astronaut.

Microcanonical rates, gap times, and phase space dividing surfaces

NARCIS (Netherlands)

Ezra, Gregory S.; Waalkens, Holger; Wiggins, Stephen

2009-01-01

The general approach to classical unimolecular reaction rates due to Thiele is revisited in light of recent advances in the phase space formulation of transition state theory for multidimensional systems. Key concepts, such as the phase space dividing surface separating reactants from products, the

Novel Equalization Techniques for Space Division Multiplexing Based on Stokes Space Update Rule

Directory of Open Access Journals (Sweden)

Francisco Javier Vaquero Caballero

2017-02-01

Full Text Available Space division multiplexing (SDM is a promising technology that aims to overcome the capacity crunch of optical communications. In this paper, we introduce the multiple-input multiple-output (MIMO Stokes Space Algorithm (SSA implemented in frequency domain, a novel equalization technique for space division multiplexing (SDM. Although different papers have been published about the SSA and its MIMO implementation, we provide for the first time an analysis of the of the convergence speed and frequency offset of the SSA compared to the least mean square (LMS. SSA algorithm can deal with higher frequency offsets and linewidths than LMS, being suitable for optical communications with higher phase noise. SSA does not need pre-compensation of frequency offset, which can be compensated after equalization without penalties. On the other hand, due to reduced convergence speed, SSA requires longer training sequences than LMS.

Space-Charge Experiments at the CERN Proton Synchrotron

CERN Document Server

Franchetti, Giuliano; Hofmann, I; Martini, M; Métral, E; Qiang, J; Ryne, D; Steerenberg, R; CFA Beam Dynamics Workshop “High Intensity and Brightness Hadron Beams”

2005-01-01

Benchmarking of the simulation codes used for the design of the next generation of high beam power accelerators is of paramount importance due to the very demanding requirements on the level of beam losses. This is usually accomplished by comparing simulation results against available theories, and more importantly, against experimental observations. To this aim, a number of well-defined test cases, obtained by accurate measurements made in existing machines, are of great interest. Such measurements have been made in the CERN Proton Synchrotron to probe three space-charge effects: (i) transverse emittance blow-up due to space-charge induced crossing of the integer or half-integer stop-band, (ii) space-charge and octupole driven resonance trapping, and (iii) intensity-dependent emittance transfer between the two transverse planes. The last mechanism is discussed in detail in this paper and compared to simulation predictions.

An Overview of Effects of Space Radiation on the Electronics

International Nuclear Information System (INIS)

Hwang, Sun Tae; Shin, Dong Kwan; Son, Young Jong; Kim Jin Hong

2009-01-01

The first Korean astronaut successfully carried out the scientific experiments at International Space Station (ISS) in April 2008. Due to the government's strong will and support for the field of space, Korea has enhanced its space technology based on the accomplishments in space development. On October 12∼16, 2009 the 60 th International Astronautical Congress (IAC) was held in Daejeon. IAC 2009 must serve as a place for the extensive exchange of global space technology and information in order to speed up the development of space technology in Korea. With regard for space research and development, the radiation effects in space have been reviewed from the viewpoint of electronics

Measuring space radiation shielding effectiveness

Directory of Open Access Journals (Sweden)

Bahadori Amir

2017-01-01

Full Text Available Passive radiation shielding is one strategy to mitigate the problem of space radiation exposure. While space vehicles are constructed largely of aluminum, polyethylene has been demonstrated to have superior shielding characteristics for both galactic cosmic rays and solar particle events due to the high hydrogen content. A method to calculate the shielding effectiveness of a material relative to reference material from Bragg peak measurements performed using energetic heavy charged particles is described. Using accelerated alpha particles at the National Aeronautics and Space Administration Space Radiation Laboratory at Brookhaven National Laboratory, the method is applied to sample tiles from the Heat Melt Compactor, which were created by melting material from a simulated astronaut waste stream, consisting of materials such as trash and unconsumed food. The shielding effectiveness calculated from measurements of the Heat Melt Compactor sample tiles is about 10% less than the shielding effectiveness of polyethylene. Shielding material produced from the astronaut waste stream in the form of Heat Melt Compactor tiles is therefore found to be an attractive solution for protection against space radiation.

Measuring space radiation shielding effectiveness

Science.gov (United States)

Bahadori, Amir; Semones, Edward; Ewert, Michael; Broyan, James; Walker, Steven

2017-09-01

Passive radiation shielding is one strategy to mitigate the problem of space radiation exposure. While space vehicles are constructed largely of aluminum, polyethylene has been demonstrated to have superior shielding characteristics for both galactic cosmic rays and solar particle events due to the high hydrogen content. A method to calculate the shielding effectiveness of a material relative to reference material from Bragg peak measurements performed using energetic heavy charged particles is described. Using accelerated alpha particles at the National Aeronautics and Space Administration Space Radiation Laboratory at Brookhaven National Laboratory, the method is applied to sample tiles from the Heat Melt Compactor, which were created by melting material from a simulated astronaut waste stream, consisting of materials such as trash and unconsumed food. The shielding effectiveness calculated from measurements of the Heat Melt Compactor sample tiles is about 10% less than the shielding effectiveness of polyethylene. Shielding material produced from the astronaut waste stream in the form of Heat Melt Compactor tiles is therefore found to be an attractive solution for protection against space radiation.

Phase-space dynamics of Bianchi IX cosmological models

International Nuclear Information System (INIS)

Soares, I.D.

1985-01-01

The complex phase-space dynamical behaviour of a class of Biachi IX cosmological models is discussed, as the chaotic gravitational collapse due Poincare's homoclinic phenomena, and the n-furcation of periodic orbits and tori in the phase space of the models. Poincare maps which show this behaviour are constructed merically and applications are discussed. (Author) [pt

Emergence of cosmic space and minimal length in quantum gravity

Energy Technology Data Exchange (ETDEWEB)

Farag Ali, Ahmed, E-mail: ahmed.ali@fsc.bu.edu.eg [Center for Fundamental Physics, Zewail City of Science and Technology, Giza, 12588 (Egypt); Dept. of Physics, Faculty of Sciences, Benha University, Benha, 13518 (Egypt)

2014-05-01

An emergence of cosmic space has been suggested by Padmanabhan in [1]. This new interesting approach argues that the expansion of the universe is due to the difference between the number of degrees of freedom on a holographic surface and the one in the emerged bulk. In this paper, we derive, using emergence of cosmic space framework, the general dynamical equation of FRW universe filled with a perfect fluid by considering a generic form of the entropy as a function of area. Our derivation is considered as a generalization of emergence of cosmic space with a general form of entropy. We apply our equation with higher dimensional spacetime and derive modified Friedmann equation in Gauss–Bonnet gravity. We then apply our derived equation with the corrected entropy-area law that follows from Generalized Uncertainty Principle (GUP) and derive a modified Friedmann equations due to the GUP. We then derive the modified Raychaudhuri equation due to GUP in emergence of cosmic space framework and investigate it using fixed point method. Studying this modified Raychaudhuri equation leads to nonsingular solutions which may resolve singularities in FRW universe.

Phase space diffusion in turbulent plasmas

International Nuclear Information System (INIS)

Pecseli, H.L.

1990-01-01

Turbulent diffusion of charged test particles in electrostatic plasma turbulence is reviewed. Two different types of test particles can be distinguished. First passice particles which are subject to the fluctuating electric fields without themselves contributing to the local space charge. The second type are particles introduced at a prescribed phase space position at a certain time and which then self-consistently participate in the phase space dynamics of the turbulent. The latter ''active'' type of particles can be subjected to an effective frictional force due to radiation of plasma waves. In terms of these test particle types, two basically different problems can be formulated. One deals with the diffusion of a particle with respect to its point of release in phase space. Alternatively the relative diffusion between many, or just two, particles can be analyzed. Analytical expressions for the mean square particle displacements in phase space are discussed. More generally equations for the full probability densities are derived and these are solved analytically in special limits. (orig.)

Laser guide stars for optical free-space communications

Science.gov (United States)

Mata-Calvo, Ramon; Bonaccini Calia, Domenico; Barrios, Ricardo; Centrone, Mauro; Giggenbach, Dirk; Lombardi, Gianluca; Becker, Peter; Zayer, Igor

2017-02-01

The German Aerospace Center (DLR) and the European Southern Observatory (ESO) performed a measurement campaign together in April and July 2016 at Teide-Observatory (Tenerife), with the support of the European Space Agency (ESA), to investigate the use of laser guide stars (LGS) in ground to space optical communications. Atmospheric turbulence causes strong signal fluctuations in the uplink, due to scintillation and beam wander. In space communications, the use of the downlink channel as reference for pointing and for pre-distortion adaptive optics is limited by the size of the isokinetic and isoplanatic angle in relation to the required point-ahead angle. Pointing and phase errors due to the decorrelation between downward and upward beam due to the point-ahead angle may have a severe impact on the required transmit power and the stability of the communications link. LGSs provide a self-tailored reference to any optical ground-to-space link, independently of turbulence conditions and required point-ahead angle. In photon-starved links, typically in deep-space scenarios, LGSs allow dedicating all downlink received signal to communications purposes, increasing the available link margin. The scope of the joint DLR-ESO measurement campaign was, first, to measure the absolute value of the beam wander (uplink-tilt) using a LGS, taking a natural star as a reference, and, second, to characterize the decrease of correlation between uplink-tilt and downlink-tilt with respect to the angular separation between both sources. This paper describes the experiments performed during the measurement campaigns, providing an overview of the measured data and the first outcomes of the data post-processing.

Diclofenac Patch for Treatment of Mild to Moderate Tendonitis or Bursitis

Science.gov (United States)

2008-08-05

Rotator Cuff Tendonitis; Bicipital Tendonitis; Subdeltoid Bursitis of the Shoulder; Subacromial Bursitis of the Shoulder; Medial Epicondylitis of the Elbow; Lateral Epicondylitis of the Elbow; DeQuervain's Tenosynovitis of the Wrist

Upper Incisor Changes Due to Modifying the Point of Application of Forces during Space Closure in MBT Technique

Directory of Open Access Journals (Sweden)

H. Ravanmehr

2004-06-01

Full Text Available Statement of Problem: A recent technique (MBT has been introduced for easy and efficient orthodontic treatment by means of straight wire fixed appliances. Although this technique has many advantages, in space closure stage causes up righting problem in upper incisors, which should be adjusted by applying additional torque in anterior region.Purpose: The purpose of this clinical trial was to determine whether there is a significant difference in final incisor inclination (torque of two groups one treated with MBT technique and the other by changing the point of application of the closing force (in anterior region.Materials and Methods: Twelve patients (8 girls, 4 boys with Cl I malocclusion and crowding, whom were candidate for first premolars extraction, were selected.For space closure, 6 anterior teeth (canine to canine in upper and lower jaws ligated and the applied force was from the hooks on canines to hooks on the first molars.After space closure the results compared with the results of a previous study which treatment plan was according to original MBT technique (anterior hooks soldered to arch wire. Forces applied randomly among quadrants by NiTi coil spring (American Orthodontics Co. or active tie backs with elastic modules (Dentaurum Co.Results: The results showed a statistically significant difference between final torques of two techniques (P=0.0001. Also, the rate of space closure with NiTi coils was significantly greater than active tie back (P=0.0001.Conclusion: Anchorage loss in two groups compared and the results indicated significantly lower anchorage loss in NiTi coil spring group (P=0.035.

Legal Consequences of the Pollution of Outer Space with Space Debris

Science.gov (United States)

Stubbe, Peter

2017-07-01

Space debris has grown to be a significant problem for outer space activities. The remnants of human activities in space are very diverse; they can be tiny paint flakes, all sorts of fragments, or entirely intact—but otherwise nonfunctional spacecraft and rocket bodies. The amount of debris is increasing at a growing pace, thus raising the risk of collision with operational satellites. Due to the relative high velocities involved in on-orbit collisions, their consequences are severe; collisions lead to significant damage or the complete destruction of the affected spacecraft. Protective measures and collision avoidance have thus become a major concern for spacecraft operators. The pollution of space with debris must, however, not only be seen as an unfavorable circumstance that accompanies space activities and increases the costs and complexity of outer space activities. Beyond this rather technical perspective, the presence of man-made, nonfunctional objects in space represents a global environmental concern. Similar to the patterns of other environmental problems on Earth, debris generation appears to have surpassed the absorption capacity of the space environment. Studies indicate that the evolution of the space object environment has crossed the tipping point to a runaway situation in which an increasing number of collisions―mostly among debris―leads to an uncontrolled population growth. It is thus in the interest of all mankind to address the debris problem in order to preserve the space environment for future generations. International space law protects the space environment. Article IX of the Outer Space Treaty obligates States to avoid the harmful contamination of outer space. The provision corresponds to the obligation to protect the environment in areas beyond national jurisdiction under the customary "no harm" rule of general environmental law. These norms are applicable to space debris and establish the duty not to pollute outer space by limiting

GPS Space Service Volume: Ensuring Consistent Utility Across GPS Design Builds for Space Users

Science.gov (United States)

Bauer, Frank H.; Parker, Joel Jefferson Konkl; Valdez, Jennifer Ellen

2015-01-01

GPS availability and signal strength originally specified for users on or near surface of Earth with transmitted power levels specified at edge-of-Earth, 14.3 degrees. Prior to the SSV specification, on-orbit performance of GPS varied from block build to block build (IIA, IIRM, IIF) due to antenna gain and beam width variances. Unstable on-orbit performance results in significant risk to space users. Side-lobe signals, although not specified, were expected to significantly boost GPS signal availability for users above the constellation. During GPS III Phase A, NASA noted significant discrepancies in power levels specified in GPS III specification documents, and measured on-orbit performance. To stabilize the signal for high altitude space users, NASA DoD team in 2003-2005 led the creation of new Space Service Volume (SSV) definition and specifications.

Longitudinal Space Charge in the SPS

CERN Document Server

Lasheen, Alexandre

2016-01-01

Longitudinal instabilities due to the SPS beam coupling impedance are a major issue for future projects and it is essential to have an accurate SPS impedance model to study them. The longitudinal space charge effect can be modelled by a pure reactive impedance and should also be included in simulations as it may have an impact at low energy. In this Note, the effect of the longitudinal space charge in the SPS is evaluated by taking into account the variation of the transverse beam size and vacuum chamber geometry along the ring. Scaling laws are used to investigate what are the most important parameters for the evaluation of the longitudinal space charge impedance.

Dirac equation in noncommutative space for hydrogen atom

International Nuclear Information System (INIS)

Adorno, T.C.; Baldiotti, M.C.; Chaichian, M.; Gitman, D.M.; Tureanu, A.

2009-01-01

We consider the energy levels of a hydrogen-like atom in the framework of θ-modified, due to space noncommutativity, Dirac equation with Coulomb field. It is shown that on the noncommutative (NC) space the degeneracy of the levels 2S 1/2 , 2P 1/2 and 2P 3/2 is lifted completely, such that new transition channels are allowed.

Collaborative Commercial Space Situational Awareness

Science.gov (United States)

Kelso, T. S.; Hendrix, D.; Sibert, D.; Hall, R. A.; Therien, W.

2013-09-01

There is an increasing recognition by commercial and civil space operators of the need for space situational awareness (SSA) data to support ongoing conjunction analysis, maneuver planning, and radio frequency interference mitigation as part of daily operations. While some SSA data is available from the Joint Space Operations Center via the Space Track web site, access to raw observations and photometric data is limited due to national security considerations. These data, however, are of significant value in calibrating intra- and inter-operator orbit determination results, determining inter-system biases, and assessing operating profiles in the geostationary orbit. This paper details an ongoing collaborative effort to collect and process optical observations and photometric data using a network of low-cost telescope installations and shows how these data are being used to support ongoing operations in the Space Data Center. This presentation will demonstrate how by leveraging advance photometric processing algorithms developed for Missile Defense Agency and the Ballistic Missile Defense (BMD) mission ExoAnalytic and AGI have been able to provide actionable SSA for satellite operators from small telescopes in less than optimal viewing conditions. Space has become an increasingly cluttered environment requiring satellite operators to remain forever vigilant in order to prevent collisions to preserve their assets and prevent further cluttering the space environment. The Joint Space Operations Center (JSpOC), which tracks all objects in earth orbit, reports possible upcoming conjunctions to operators by providing Conjunction Summary Messages (CSMs). However due to large positional uncertainties in the forward predicted position of space objects at the time closest approach the volume of CSMs is excessive to the point that maneuvers in response to CSMs without additional screening is cost prohibitive. CSSI and the Space Data Association have been able to screen most

Exploring space-time structure of human mobility in urban space

Science.gov (United States)

Sun, J. B.; Yuan, J.; Wang, Y.; Si, H. B.; Shan, X. M.

2011-03-01

Understanding of human mobility in urban space benefits the planning and provision of municipal facilities and services. Due to the high penetration of cell phones, mobile cellular networks provide information for urban dynamics with a large spatial extent and continuous temporal coverage in comparison with traditional approaches. The original data investigated in this paper were collected by cellular networks in a southern city of China, recording the population distribution by dividing the city into thousands of pixels. The space-time structure of urban dynamics is explored by applying Principal Component Analysis (PCA) to the original data, from temporal and spatial perspectives between which there is a dual relation. Based on the results of the analysis, we have discovered four underlying rules of urban dynamics: low intrinsic dimensionality, three categories of common patterns, dominance of periodic trends, and temporal stability. It implies that the space-time structure can be captured well by remarkably few temporal or spatial predictable periodic patterns, and the structure unearthed by PCA evolves stably over time. All these features play a critical role in the applications of forecasting and anomaly detection.

Registration of Space Objects

Science.gov (United States)

Schmidt-Tedd, Bernhard

2017-07-01

Space objects are subject to registration in order to allocate "jurisdiction and control" over those objects in the sovereign-free environment of outer space. This approach is similar to the registration of ships in view of the high sea and for aircrafts with respect to the international airspace. Registration is one of the basic principles of space law, starting with UN General Assembly Resolution 1721 B (XVI) of December 20, 1961, followed by Resolution 1962 (XVIII) of December 13, 1963, then formulated in Article VIII of the Outer Space Treaty of 1967 and as specified in the Registration Convention of 1975. Registration of space objects can be seen today as a principle of customary international law, relevant for each spacefaring state. Registration is divided into a national and an international level. The State Party establishes a national registry for its space objects, and those registrations have to be communicated via diplomatic channel to the UN Register of space objects. This UN Register is handled by the UN Office for Outer Space Affairs (UNOOSA) and is an open source of information for space objects worldwide. Registration is linked to the so-called launching state of the relevant space object. There might be more than one launching state for the specific launch event, but only one state actor can register a specific space object. The state of registry gains "jurisdiction and control" over the space object and therefore no double registration is permissible. Based on the established UN Space Law, registration practice was subject to some adaptions due to technical developments and legal challenges. After the privatization of the major international satellite organizations, a number of non-registrations had to be faced. The state actors reacted with the UN Registration Practice Resolution of 2007 as elaborated in the Legal Subcommittee of UNCOPUOS, the Committee for the Peaceful Use of Outer Space. In this context an UNOOSA Registration Information

New solutions for the space debris problem

CERN Document Server

Pelton, Joseph N

2015-01-01

Addressing a pressing issue in space policy, Pelton explores the new forms of technology that are being developed to actively remove the defunct space objects from orbit and analyzes their implications in the existing regime of international space law and public international law. This authoritative review covers the due diligence guidelines that nations are using to minimize the generation of new debris, mandates to de-orbit satellites at end of life, and innovative endeavours to remove non-functional satellites, upper stage rockets and other large debris from orbit under new institutional, financial and regulatory guidelines.  Commercial space services currently exceed 100 billion USD business per annum, but the alarming proliferation in the population of orbital debris in low, medium and geosynchronous satellite orbits poses a serious threat to all kinds of space assets and applications. There is a graver concern that the existing space debris will begin to collide in a cascading manner, generating furth...

Recurrent Syncope due to Esophageal Squamous Cell Carcinoma

OpenAIRE

Casini, Alessandro; Tschanz, Elisabeth; Dietrich, Pierre-Yves; Nendaz, Mathieu

2011-01-01

Syncope is caused by a wide variety of disorders. Recurrent syncope as a complication of malignancy is uncommon and may be difficult to diagnose and to treat. Primary neck carcinoma or metastases spreading in parapharyngeal and carotid spaces can involve the internal carotid artery and cause neurally mediated syncope with a clinical presentation like carotid sinus syndrome. We report the case of a 76-year-old man who suffered from recurrent syncope due to invasion of the right carotid sinus b...

A note on 'Some results on the IF-normed spaces'

International Nuclear Information System (INIS)

Saadati, Reza

2009-01-01

Recently, Lael and Nourouzi [Some results on the IF-normed spaces. Chaos, Solitons and Fractals 2006; doi:10.1016/j.chaos.2006.10.019] introduced and studied a new notation of IF-normed spaces by using the idea of intuitionistic fuzzy normed spaces due to Saadati and Park [On the intuitionistic fuzzy topological spaces. Chaos, Solitons and Fractals 2006;27:331-44], a special continuous t-norm i.e. min and a special continuous s-norm i.e. max. In this note, we consider the modified definition of IF-normed space i.e. LF-normed spaces and prove the open mapping and closed graph theorems for this space using arbitrary continuous t-norm.

Property rights in space: Moving the goal posts so the players don't ...

African Journals Online (AJOL)

Abstract. Elsewhere in "Rethinking Terra Nullius and Property in Space", I have argued that due to the changing circumstances of access to space by private entities rather than governments, the current legal situation with regard to ownership in space should be reconsidered. As it stands, ownership in space is governed by ...

Space space space

CERN Document Server

Trembach, Vera

2014-01-01

Space is an introduction to the mysteries of the Universe. Included are Task Cards for independent learning, Journal Word Cards for creative writing, and Hands-On Activities for reinforcing skills in Math and Language Arts. Space is a perfect introduction to further research of the Solar System.

High-Efficiency, High-Power Laser Transmitter for Deep-Space Communication, Phase II

Data.gov (United States)

National Aeronautics and Space Administration — There is demand for vastly improved deep space satellite communications links. As data rates dramatically increase due to new sensor technologies and the desire to...

Evaluation of the effects of subgingival injection of Simvastatin on space re-opening after orthodontic space closure in adults

Directory of Open Access Journals (Sweden)

Arezoo Jahanbin

2016-03-01

Full Text Available Background. This clinical trial evaluated the effect of Simvastatin on space re-opening after orthodontic space closure and its effect on the gingival index (GI and clinical attachment loss (CAL. Methods. 16 females, 25‒40 years old, with spaces between anterior mandibular teeth due to chronic periodontitis were participated in this study. The patients were randomly divided into control and experimental groups. In the experimental group, 1.2% Simvastatin gel and in the control group, 0.9% sodium chloride as a placebo was injected into the pocket depth of the six anterior teeth. The amount of space reopening, GI and CAL were measured. Results. No serious complications were observed during interventions and follow-up periods. Space re-opening was significantly reduced in patients receiving Simvastatin (P < 0.001. Moreover, GI reduction was significantly greater in Sim-vastatin group compared to the control group (P < 0.001. However, CAL did not demonstrate a significant difference between the groups. Conclusion. Simvastatin may decrease space re-opening after orthodontic space closure in human anterior teeth.

Dirac equation in noncommutative space for hydrogen atom

Energy Technology Data Exchange (ETDEWEB)

Adorno, T.C., E-mail: tadorno@nonada.if.usp.b [Instituto de Fisica, Universidade de Sao Paulo, Caixa Postal 66318, CEP 05508-090 Sao Paulo, SP (Brazil); Baldiotti, M.C., E-mail: baldiott@fma.if.usp.b [Instituto de Fisica, Universidade de Sao Paulo, Caixa Postal 66318, CEP 05508-090 Sao Paulo, SP (Brazil); Chaichian, M., E-mail: Masud.Chaichian@helsinki.f [Department of Physics, University of Helsinki and Helsinki Institute of Physics, PO Box 64, FIN-00014 Helsinki (Finland); Gitman, D.M., E-mail: gitman@dfn.if.usp.b [Instituto de Fisica, Universidade de Sao Paulo, Caixa Postal 66318, CEP 05508-090 Sao Paulo, SP (Brazil); Tureanu, A., E-mail: Anca.Tureanu@helsinki.f [Department of Physics, University of Helsinki and Helsinki Institute of Physics, PO Box 64, FIN-00014 Helsinki (Finland)

2009-11-30

We consider the energy levels of a hydrogen-like atom in the framework of theta-modified, due to space noncommutativity, Dirac equation with Coulomb field. It is shown that on the noncommutative (NC) space the degeneracy of the levels 2S{sub 1/2}, 2P{sub 1/2} and 2P{sub 3/2} is lifted completely, such that new transition channels are allowed.

Space-charge calculations in synchrotrons

Energy Technology Data Exchange (ETDEWEB)

Machida, S.

1993-05-01

One obvious bottleneck of achieving high luminosity in hadron colliders, such as the Superconducting Super Collider (SSC), is the beam emittance growth, due to space-charge effects in low energy injector synchrotrons. Although space-charge effects have been recognized since the alternating-gradient synchrotron was invented, and the Laslett tune shift usually calculated to quantify these effects, our understanding of the effects is limited, especially when the Laslett tune shift becomes a large fraction of the integer. Using the Simpsons tracking code, which we developed to study emittance preservation issues in proton synchrotrons, we investigated space-charge effects in the SSC Low Energy Booster (LEB). We observed detailed dependence on parameters such as beam intensity, initial emittance, injection energy, lattice function, and longitudinal motion. A summary of those findings, as well as the tracking technique we developed for the study, are presented.

Reliability Growth in Space Life Support Systems

Science.gov (United States)

Jones, Harry W.

2014-01-01

A hardware system's failure rate often increases over time due to wear and aging, but not always. Some systems instead show reliability growth, a decreasing failure rate with time, due to effective failure analysis and remedial hardware upgrades. Reliability grows when failure causes are removed by improved design. A mathematical reliability growth model allows the reliability growth rate to be computed from the failure data. The space shuttle was extensively maintained, refurbished, and upgraded after each flight and it experienced significant reliability growth during its operational life. In contrast, the International Space Station (ISS) is much more difficult to maintain and upgrade and its failure rate has been constant over time. The ISS Carbon Dioxide Removal Assembly (CDRA) reliability has slightly decreased. Failures on ISS and with the ISS CDRA continue to be a challenge.

The Study of Environmental Crisis and Local Distribution of Green Space in Tehran City

OpenAIRE

K. zayyari; L. Vahedian Beiky; Z. Parnoon

2012-01-01

Extended abstract1-IntroductionUncontrolled development of large cities due to the increase in population and migration has led to a massive environmental destruction and pollution, and the latter has destroyed green spaces within the city and changed the land use. Therefore, the need for green space and connection with nature has an important role in human life. The best way to reduce the destructive effects of environmental hazards is the development of green space. Due to its wide range of...

Linear entropy in quantum phase space

International Nuclear Information System (INIS)

Rosales-Zarate, Laura E. C.; Drummond, P. D.

2011-01-01

We calculate the quantum Renyi entropy in a phase-space representation for either fermions or bosons. This can also be used to calculate purity and fidelity, or the entanglement between two systems. We show that it is possible to calculate the entropy from sampled phase-space distributions in normally ordered representations, although this is not possible for all quantum states. We give an example of the use of this method in an exactly soluble thermal case. The quantum entropy cannot be calculated at all using sampling methods in classical symmetric (Wigner) or antinormally ordered (Husimi) phase spaces, due to inner-product divergences. The preferred method is to use generalized Gaussian phase-space methods, which utilize a distribution over stochastic Green's functions. We illustrate this approach by calculating the reduced entropy and entanglement of bosonic or fermionic modes coupled to a time-evolving, non-Markovian reservoir.

Linear entropy in quantum phase space

Energy Technology Data Exchange (ETDEWEB)

Rosales-Zarate, Laura E. C.; Drummond, P. D. [Centre for Atom Optics and Ultrafast Spectroscopy, Swinburne University of Technology, Melbourne 3122 (Australia)

2011-10-15

We calculate the quantum Renyi entropy in a phase-space representation for either fermions or bosons. This can also be used to calculate purity and fidelity, or the entanglement between two systems. We show that it is possible to calculate the entropy from sampled phase-space distributions in normally ordered representations, although this is not possible for all quantum states. We give an example of the use of this method in an exactly soluble thermal case. The quantum entropy cannot be calculated at all using sampling methods in classical symmetric (Wigner) or antinormally ordered (Husimi) phase spaces, due to inner-product divergences. The preferred method is to use generalized Gaussian phase-space methods, which utilize a distribution over stochastic Green's functions. We illustrate this approach by calculating the reduced entropy and entanglement of bosonic or fermionic modes coupled to a time-evolving, non-Markovian reservoir.

Europe and Asia in Space, 1993-1994.

Science.gov (United States)

1993-01-01

For Privatization", Aviation Week and Space Technology, 27 June 1994, pp. 22-23. 96. "RKK Energia Issues Stock Due to Privatization Order", Space News...multi-year renovation project was undertaken in Kourou to support not only the forthcoming Ariane 5 but also the con- tinuing Ariane 4 missions. By...via the newly formed Lockheed- Khrunichev- Energia joint venture. By the end of 1994 no commercial Proton launches had been undertaken, and the first

Experimental Test Rig for Optimal Control of Flexible Space Robotic Arms

Science.gov (United States)

2016-12-01

the test bed design. A single link arm with a torsional, helical spring at the base was finalized to investigate the effects of coupling due to...test bed design. A single link arm with a torsional, helical spring at the base was finalized to investigate the effects of coupling due to movement...Source: [4]. A challenge with space systems is that it costs a lot of money to put a satellite or spacecraft into space. Estimates to send one kilogram

Space in Space: Designing for Privacy in the Workplace

Science.gov (United States)

Akin, Jonie

2015-01-01

Privacy is cultural, socially embedded in the spatial, temporal, and material aspects of the lived experience. Definitions of privacy are as varied among scholars as they are among those who fight for their personal rights in the home and the workplace. Privacy in the workplace has become a topic of interest in recent years, as evident in discussions on Big Data as well as the shrinking office spaces in which people work. An article in The New York Times published in February of this year noted that "many companies are looking to cut costs, and one way to do that is by trimming personal space". Increasingly, organizations ranging from tech start-ups to large corporations are downsizing square footage and opting for open-office floorplans hoping to trim the budget and spark creative, productive communication among their employees. The question of how much is too much to trim when it comes to privacy, is one that is being actively addressed by the National Aeronautics and Space Administration (NASA) as they explore habitat designs for future space missions. NASA recognizes privacy as a design-related stressor impacting human health and performance. Given the challenges of sustaining life in an isolated, confined, and extreme environment such as Mars, NASA deems it necessary to determine the acceptable minimal amount for habitable volume for activities requiring at least some level of privacy in order to support optimal crew performance. Ethnographic research was conducted in 2013 to explore perceptions of privacy and privacy needs among astronauts living and working in space as part of a long-distance, long-duration mission. The allocation of space, or habitable volume, becomes an increasingly complex issue in outer space due to the costs associated with maintaining an artificial, confined environment bounded by limitations of mass while located in an extreme environment. Privacy in space, or space in space, provides a unique case study of the complex notions of

Overview of fiber optics in the natural space environment

International Nuclear Information System (INIS)

Barnes, C.; Dorsky, L.; Johnston, A.; Bergman, L.; Stassinopoulos, E.

1991-01-01

The potential applications of fiber-optic (FO) systems in spacecraft which will be exposed to the space radiation environment are discussed in view of tests conducted aboard the Long-Duration Exposure Facility and the Comet Rendezvous and Asteroid Flyby spacecraft. Attention is given to anticipated trends in the use of FO in spacecraft communications systems. The natural space radiation environment is noted to be far more benign than the military space environment, which encompasses displacement-damage effects due to significant neutron influences

Laser-induced fluorescences due to quadrupole moment transition and Stark effect in a He glow discharge

International Nuclear Information System (INIS)

Sakai, Hisashi; Takiyama, Ken; Kimura, Masahiko; Yamasaki, Motokuni; Fujita, Toshiaki; Oda, Toshiatsu; Kawasaki, Ken.

1993-01-01

The electric quadrupole moment transition and the Stark effect are investigated in a He hollow cathode discharge with laser-induced fluorescence method. It is shown that the forbidden transition from 2 1 S to 3 1 D in the negative glow is dominantly due to the quadrupole moment transition. This absorption coefficient is obtained from the laser-induced fluorescence intensity measurement in which the collisional transfers are taken into account. The result agrees with the theoretical coefficient. In the cathode dark space the fluorescence due to the Stark effect is also observed. Spatial distribution of the fluorescence is discussed, compared with the electric field distribution in the dark space. (author)

Space Shuttle Status News Conference

Science.gov (United States)

2005-01-01

Richard Gilbech, External Tank "Tiger Team" Lead, begins this space shuttle news conference with detailing the two major objectives of the team. The objectives include: 1) Finding the root cause of the foam loss on STS-114; and 2) Near and long term improvements for the external tank. Wayne Hale, Space Shuttle Program Manager, presents a chart to explain the external tank foam loss during STS-114. He gives a possible launch date for STS-121 after there has been a repair to the foam on the External Tank. He further discusses the changes that need to be made to the surrounding areas of the plant in New Orleans, due to Hurricane Katrina. Bill Gerstemaier, NASA Associate Administrator for Space Operations, elaborates on the testing of the external tank foam loss. The discussion ends with questions from the news media about a fix for the foam, replacement of the tiles, foam loss avoidance, the root cause of foam loss and a possible date for a new external tank to be shipped to NASA Kennedy Space Center.

The Future of Astrometry in Space

Directory of Open Access Journals (Sweden)

Antonella Vallenari

2018-04-01

Full Text Available This contribution focuses on the importance of astrometry and on its future developments. Over the centuries astrometry has greatly contributed to the advance of the knowledge of the Universe. Nowadays a major breakthrough is on the way due to astrometric sky surveys from space. ESA space missions Hipparcos first and then Gaia point out the outstanding contribution that space astrometry can provide to our knowledge in many fields of astrophysics, going from the Milky Way formation and evolution, to stellar astrophysics, extra-galactic astrophysics, and fundamental physics. We briefly outline the properties of Gaia first and second data release, and the accuracies expected end-of-mission. The next big advance in space astrometry would be either to improve the astrometric accuracy of one order of magnitude, or to move to a different wavelength domain. While both options have the potential to bring us in a new era of discovery, they have to face enormous issues. We summarize the future directions in space astrometry that are proposed or under investigation by the scientific community, their main challenges and the expected outcome.

Active Space Debris Removal System

Directory of Open Access Journals (Sweden)

Gabriele GUERRA

2017-06-01

Full Text Available Since the start of the space era, more than 5000 launches have been carried out, each carrying satellites for many disparate uses, such as Earth observation or communication. Thus, the space environment has become congested and the problem of space debris is now generating some concerns in the space community due to our long-lived belief that “space is big”. In the last few years, solutions to this problem have been proposed, one of those is Active Space Debris Removal: this method will reduce the increasing debris growth and permit future sustainable space activities. The main idea of the method proposed below is a drag augmentation system: use a system capable of putting an expanded foam on a debris which will increase the area-to-mass ratio to increase the natural atmospheric drag and solar pressure. The drag augmentation system proposed here requires a docking system; the debris will be pushed to its release height and then, after un-docking, an uncontrolled re-entry takes place ending with a burn up of the object and the foam in the atmosphere within a given time frame. The method requires an efficient way to change the orbit between two debris. The present paper analyses such a system in combination with an Electric Propulsion system, and emphasizes the choice of using two satellites to remove five effective rockets bodies debris within a year.

A Study of Thermal Performance of Contemporary Technology-Rich Educational Spaces

Directory of Open Access Journals (Sweden)

Sarah Elmasry

2013-08-01

Full Text Available One of the most dominant features of a classroom space is its high occupancy, which results in high internal heat gain (approximately 5 KW. Furthermore, installation of educational technologies, such as smart boards, projectors and computers in the spaces increases potential internal heat gain. Previous studies on office buildings indicate that with the introduction of IT equipment in spaces during the last decade, cooling load demands are increasing with an associated increase in summer electrical demand. Due to the fact that educational technologies in specific correspond to pedagogical practices within the space, a lot of variations due to occupancy patterns occur. Also, thermal loads caused by educational technologies are expected to be dependent on spatial configuration, for example, position with respect to the external walls, lighting equipment, mobility of devices. This study explores the thermal impact of educational technologies in 2 typical educational spaces in a facility of higher education; the classroom and the computer lab. The results indicate that a heat gain ranging between 0.06 and 0.095 KWh/m2 is generated in the rooms when educational technologies are in use. The second phase of this study is ongoing, and investigates thermal zones within the rooms due to distribution of educational technologies. Through simulation of thermal performance of the rooms, alternative room configurations are thus recommended in response to the observed thermal zones.

The Event Horizon of The Schwarzschild Black Hole in Noncommutative Spaces

OpenAIRE

Nasseri, Forough

2005-01-01

The event horizon of Schwarzschild black hole is obtained in noncommutative spaces up to the second order of perturbative calculations. Because this type of black hole is non-rotating, to the first order there is no any effect on the event horizon due to the noncommutativity of space. A lower limit for the noncommutativity parameter is also obtained. As a result, the event horizon in noncommutative spaces is less than the event horizon in commutative spaces.

Space charge beam dynamics studies for a pulsed spallation source accelerator

Energy Technology Data Exchange (ETDEWEB)

Cho, Y.; Lessner, E.

1995-12-31

Feasibility studies for 2-GeV, 1-MW and 10-GeV, 5-MW rapid cycling synchrotrons (RCS) for spallation neutron sources have been completed. Both synchrotrons operate at a repetition rate of 30 Hz, and accelerate 1.04 {times} 10{sup 14} protons per pulse. The injection energy of the 2-GeV ring is 400 MeV, and the 10-GeV RCS accepts the beam from the 2-GeV machine. Work performed to-date includes calculation of the longitudinal space charge effects in the 400-MeV beam transfer line, and of both longitudinal and transverse space charge effects during the injection, capture and acceleration processes in the two rings. Results of space charge calculations in the rings led to proper choices of the working points and of rf voltage programs that prevents beam loss. Space charge effects in the 2-GeV synchrotron, in both transverse and longitudinal phase space, have major impact on the design due to the fact that the injection energy is 400 MeV. The design achieves the required performance while alleviating harmful effects due to space charge.

Path integral quantization of the Aharonov-Bohm-Coulomb system in momentum space

International Nuclear Information System (INIS)

Lin, De-Hone

2001-01-01

The Coulomb system with a charge moving in the fields of Ahanorov and Bohm is quantized via path integral in momentum space. Due to the dynamics of the system in momentum space being in curve space, our result not only gives the Green function of this interesting system in momentum space but provides the second example to answer an open problem of quantum dynamics in curved spaces posed by DeWitt in 1957: We find that the physical Hamiltonian in curved spaces does not contain the Riemannian scalar curvature R

Initial Efforts in Characterizing Radiation and Plasma Effects on Space Assets: Bridging the Space Environment, Engineering and User Community

Science.gov (United States)

Zheng, Y.; Ganushkina, N. Y.; Guild, T. B.; Jiggens, P.; Jun, I.; Mazur, J. E.; Meier, M. M.; Minow, J. I.; Pitchford, D. A.; O'Brien, T. P., III; Shprits, Y.; Tobiska, W. K.; Xapsos, M.; Rastaetter, L.; Jordanova, V. K.; Kellerman, A. C.; Fok, M. C. H.

2017-12-01

The Community Coordinated Modeling Center (CCMC) has been leading the community-wide model validation projects for many years. Such effort has been broadened and extended via the newly-launched International Forum for Space Weather Modeling Capabilities Assessment (https://ccmc.gsfc.nasa.gov/assessment/), Its objective is to track space weather models' progress and performance over time, which is critically needed in space weather operations. The Radiation and Plasma Effects Working Team is working on one of the many focused evaluation topics and deals with five different subtopics: Surface Charging from 10s eV to 40 keV electrons, Internal Charging due to energetic electrons from hundreds keV to several MeVs. Single Event Effects from solar energetic particles (SEPs) and galactic cosmic rays (GCRs) (several MeV to TeVs), Total Dose due to accumulation of doses from electrons (>100 KeV) and protons (> 1 MeV) in a broad energy range, and Radiation Effects from SEPs and GCRs at aviation altitudes. A unique aspect of the Radiation and Plasma Effects focus area is that it bridges the space environments, engineering and user community. This presentation will summarize the working team's progress in metrics discussion/definition and the CCMC web interface/tools to facilitate the validation efforts. As an example, tools in the areas of surface charging/internal charging will be demoed.

Classical mechanics in non-commutative phase space

International Nuclear Information System (INIS)

Wei Gaofeng; Long Chaoyun; Long Zhengwen; Qin Shuijie

2008-01-01

In this paper the laws of motion of classical particles have been investigated in a non-commutative phase space. The corresponding non-commutative relations contain not only spatial non-commutativity but also momentum non-commutativity. First, new Poisson brackets have been defined in non-commutative phase space. They contain corrections due to the non-commutativity of coordinates and momenta. On the basis of this new Poisson brackets, a new modified second law of Newton has been obtained. For two cases, the free particle and the harmonic oscillator, the equations of motion are derived on basis of the modified second law of Newton and the linear transformation (Phys. Rev. D, 2005, 72: 025010). The consistency between both methods is demonstrated. It is shown that a free particle in commutative space is not a free particle with zero-acceleration in the non-commutative phase space, but it remains a free particle with zero-acceleration in non-commutative space if only the coordinates are non-commutative. (authors)

Omicron space habitat—research stage II

Science.gov (United States)

Doule, Ondřej; Šálený, Vratislav; Hérin, Benoît; Rousek, Tomáš

2012-01-01

The design presented in this paper is in response to the revolution in private space activities, the increasing public interest in commercial flights to space and the utilization of structures such as space hotels or private orbital habitats. The baseline for the Omicron design concept is the Russian Salyut derived space station module. Salyut was the first space station to orbit the Earth. Its unique design and technical features were what made the development of space stations Salyut 1-7, MIR and the International Space Station (ISS) Zwezda service module possible. Due to its versatility and the reliable operating launch vehicle Proton, this space module series has the potential to be adapted for space hotel development. This paper proposes a conceptual design of the space habitat called Omicron, with particular focus on interior design for the microgravity environment. The Omicron concepts address the needs of space tourism with a strong emphasis on the safety and comfort of the spaceflight participants. The Omicron habitat supports three inhabitants in nominal conditions (e.g., two passengers and one astronaut). The habitat provides a flexible interior, facilities and spaces dynamically transforming in order to accommodate various types of activities, which will be performed in an organically formed interior supporting spatial orientation and movement in microgravity. The future development potential of Omicron is also considered. The baseline version is composed solely of one rigid module with an inverted cupola for observations. An alternative version offers more space using an inflatable structure. Finally, a combination of multiple Omicron modules enables the creation of a larger orbital habitat. The Omicron's subsystems support a few days visit by trained passengers. The transport to the habitat would be provided e.g., by the Soyuz TMA spacecraft carried by the Soyuz launch vehicle in the early stage of Omicron's development, before a fully reusable

Space operation system for Chang'E program and its capability ...

Indian Academy of Sciences (India)

investment. Due to the constraint in program cost, space operation for China's first lunar exploration program will be provided by the aerospace TT&C network designed for China's manned space pro- gram. The TT&C network consists of a ... foreign spacecrafts and for five spaceships in flight experiments of China's manned ...

Theorizing Space-Time Relations in Education: The Concept of Chronotope

Science.gov (United States)

Ritella, Giuseppe; Ligorio, Maria Beatrice; Hakkarainen, Kai

2016-01-01

Due to ongoing cultural-historical transformations, the space-time of learning is radically changing, and theoretical conceptualizations are needed to investigate how such evolving space-time frames can function as a ground for learning. In this article, we argue that the concept of chronotope--from Greek chronos and topos, meaning time and…

Between-Trial Forgetting Due to Interference and Time in Motor Adaptation.

Directory of Open Access Journals (Sweden)

Sungshin Kim

Full Text Available Learning a motor task with temporally spaced presentations or with other tasks intermixed between presentations reduces performance during training, but can enhance retention post training. These two effects are known as the spacing and contextual interference effect, respectively. Here, we aimed at testing a unifying hypothesis of the spacing and contextual interference effects in visuomotor adaptation, according to which forgetting between trials due to either spaced presentations or interference by another task will promote between-trial forgetting, which will depress performance during acquisition, but will promote retention. We first performed an experiment with three visuomotor adaptation conditions: a short inter-trial-interval (ITI condition (SHORT-ITI; a long ITI condition (LONG-ITI; and an alternating condition with two alternated opposite tasks (ALT, with the same single-task ITI as in LONG-ITI. In the SHORT-ITI condition, there was fastest increase in performance during training and largest immediate forgetting in the retention tests. In contrast, in the ALT condition, there was slowest increase in performance during training and little immediate forgetting in the retention tests. Compared to these two conditions, in the LONG-ITI, we found intermediate increase in performance during training and intermediate immediate forgetting. To account for these results, we fitted to the data six possible adaptation models with one or two time scales, and with interference in the fast, or in the slow, or in both time scales. Model comparison confirmed that two time scales and some degree of interferences in either time scale are needed to account for our experimental results. In summary, our results suggest that retention following adaptation is modulated by the degree of between-trial forgetting, which is due to time-based decay in single adaptation task and interferences in multiple adaptation tasks.

On Λ-Type Duality of Frames in Banach Spaces

Directory of Open Access Journals (Sweden)

Renu Chugh

2013-11-01

Full Text Available Frames are redundant system which are useful in the reconstruction of certain classes of spaces. The dual of a frame (Hilbert always exists and can be obtained in a natural way. Due to the presence of three Banach spaces in the definition of retro Banach frames (or Banach frames duality of frames in Banach spaces is not similar to frames for Hilbert spaces. In this paper we introduce the notion of Λ-type duality of retro Banach frames. This can be generalized to Banach frames in Banach spaces. Necessary and sufficient conditions for the existence of the dual of retro Banach frames are obtained. A special class of retro Banach frames which always admit a dual frame is discussed.

Acoustic rainbow trapping by coiling up space

KAUST Repository

Ni, Xu

2014-11-13

We numerically realize the acoustic rainbow trapping effect by tapping an air waveguide with space-coiling metamaterials. Due to the high refractive-index of the space-coiling metamaterials, our device is more compact compared to the reported trapped-rainbow devices. A numerical model utilizing effective parameters is also calculated, whose results are consistent well with the direct numerical simulation of space-coiling structure. Moreover, such device with the capability of dropping different frequency components of a broadband incident temporal acoustic signal into different channels can function as an acoustic wavelength division de-multiplexer. These results may have potential applications in acoustic device design such as an acoustic filter and an artificial cochlea.

Acoustic rainbow trapping by coiling up space

KAUST Repository

Ni, Xu; Wu, Ying; Chen, Ze-Guo; Zheng, Li-Yang; Xu, Ye-Long; Nayar, Priyanka; Liu, Xiao-Ping; Lu, Ming-Hui; Chen, Yan-Feng

2014-01-01

We numerically realize the acoustic rainbow trapping effect by tapping an air waveguide with space-coiling metamaterials. Due to the high refractive-index of the space-coiling metamaterials, our device is more compact compared to the reported trapped-rainbow devices. A numerical model utilizing effective parameters is also calculated, whose results are consistent well with the direct numerical simulation of space-coiling structure. Moreover, such device with the capability of dropping different frequency components of a broadband incident temporal acoustic signal into different channels can function as an acoustic wavelength division de-multiplexer. These results may have potential applications in acoustic device design such as an acoustic filter and an artificial cochlea.

Solar water heater for NASA's Space Station

Science.gov (United States)

Somers, Richard E.; Haynes, R. Daniel

1988-01-01

The feasibility of using a solar water heater for NASA's Space Station is investigated using computer codes developed to model the Space Station configuration, orbit, and heating systems. Numerous orbit variations, system options, and geometries for the collector were analyzed. Results show that a solar water heater, which would provide 100 percent of the design heating load and would not impose a significant impact on the Space Station overall design is feasible. A heat pipe or pumped fluid radial plate collector of about 10-sq m, placed on top of the habitat module was found to be well suited for satisfying water demand of the Space Station. Due to the relatively small area required by a radial plate, a concentrator is unnecessary. The system would use only 7 to 10 percent as much electricity as an electric water-heating system.

Sun Radio Interferometer Space Experiment (SunRISE)

Science.gov (United States)

Kasper, Justin C.; SunRISE Team

2018-06-01

The Sun Radio Interferometer Space Experiment (SunRISE) is a NASA Heliophysics Explorer Mission of Opportunity currently in Phase A. SunRISE is a constellation of spacecraft flying in a 10-km diameter formation and operating as the first imaging radio interferometer in space. The purpose of SunRISE is to reveal critical aspects of solar energetic particle (SEP) acceleration at coronal mass ejections (CMEs) and transport into space by making the first spatially resolved observations of coherent Type II and III radio bursts produced by electrons accelerated at CMEs or released from flares. SunRISE will focus on solar Decametric-Hectometric (DH, 0.1 space before major SEP events, but cannot be seen on Earth due to ionospheric absorption. This talk will describe SunRISE objectives and implementation. Presented on behalf of the entire SunRISE team.

Group theoretical construction of planar noncommutative phase spaces

Energy Technology Data Exchange (ETDEWEB)

Ngendakumana, Ancille, E-mail: nancille@yahoo.fr; Todjihoundé, Leonard, E-mail: leonardt@imsp.uac.org [Institut de Mathématiques et des Sciences Physiques (IMSP), Porto-Novo (Benin); Nzotungicimpaye, Joachim, E-mail: kimpaye@kie.ac.rw [Kigali Institute of Education (KIE), Kigali (Rwanda)

2014-01-15

Noncommutative phase spaces are generated and classified in the framework of centrally extended anisotropic planar kinematical Lie groups as well as in the framework of noncentrally abelian extended planar absolute time Lie groups. Through these constructions the coordinates of the phase spaces do not commute due to the presence of naturally introduced fields giving rise to minimal couplings. By symplectic realizations methods, physical interpretations of generators coming from the obtained structures are given.

Group theoretical construction of planar noncommutative phase spaces

International Nuclear Information System (INIS)

Ngendakumana, Ancille; Todjihoundé, Leonard; Nzotungicimpaye, Joachim

2014-01-01

Noncommutative phase spaces are generated and classified in the framework of centrally extended anisotropic planar kinematical Lie groups as well as in the framework of noncentrally abelian extended planar absolute time Lie groups. Through these constructions the coordinates of the phase spaces do not commute due to the presence of naturally introduced fields giving rise to minimal couplings. By symplectic realizations methods, physical interpretations of generators coming from the obtained structures are given

A relativistic self-consistent model for studying enhancement of space charge limited emission due to counter-streaming ions

Science.gov (United States)

Lin, M. C.; Verboncoeur, J.

2016-10-01

A maximum electron current transmitted through a planar diode gap is limited by space charge of electrons dwelling across the gap region, the so called space charge limited (SCL) emission. By introducing a counter-streaming ion flow to neutralize the electron charge density, the SCL emission can be dramatically raised, so electron current transmission gets enhanced. In this work, we have developed a relativistic self-consistent model for studying the enhancement of maximum transmission by a counter-streaming ion current. The maximum enhancement is found when the ion effect is saturated, as shown analytically. The solutions in non-relativistic, intermediate, and ultra-relativistic regimes are obtained and verified with 1-D particle-in-cell simulations. This self-consistent model is general and can also serve as a comparison for verification of simulation codes, as well as extension to higher dimensions.

Space Environment Testing of Photovoltaic Array Systems at NASA's Marshall Space Flight Center

Science.gov (United States)

Phillips, Brandon S.; Schneider, Todd A.; Vaughn, Jason A.; Wright, Kenneth H., Jr.

2015-01-01

To successfully operate a photovoltaic (PV) array system in space requires planning and testing to account for the effects of the space environment. It is critical to understand space environment interactions not only on the PV components, but also the array substrate materials, wiring harnesses, connectors, and protection circuitry (e.g. blocking diodes). Key elements of the space environment which must be accounted for in a PV system design include: Solar Photon Radiation, Charged Particle Radiation, Plasma, and Thermal Cycling. While solar photon radiation is central to generating power in PV systems, the complete spectrum includes short wavelength ultraviolet components, which photo-ionize materials, as well as long wavelength infrared which heat materials. High energy electron radiation has been demonstrated to significantly reduce the output power of III-V type PV cells; and proton radiation damages material surfaces - often impacting coverglasses and antireflective coatings. Plasma environments influence electrostatic charging of PV array materials, and must be understood to ensure that long duration arcs do not form and potentially destroy PV cells. Thermal cycling impacts all components on a PV array by inducing stresses due to thermal expansion and contraction. Given such demanding environments, and the complexity of structures and materials that form a PV array system, mission success can only be ensured through realistic testing in the laboratory. NASA's Marshall Space Flight Center has developed a broad space environment test capability to allow PV array designers and manufacturers to verify their system's integrity and avoid costly on-orbit failures. The Marshall Space Flight Center test capabilities are available to government, commercial, and university customers. Test solutions are tailored to meet the customer's needs, and can include performance assessments, such as flash testing in the case of PV cells.

Scapula kinematics of pull-up techniques: Avoiding impingement risk with training changes.

Science.gov (United States)

Prinold, Joe A I; Bull, Anthony M J

2016-08-01

Overhead athletic activities and scapula dyskinesia are linked with shoulder pathology; pull-ups are a common training method for some overhead sports. Different pull-up techniques exist: anecdotally some are easier to perform, and others linked to greater incidences of pathology. This study aims to quantify scapular kinematics and external forces for three pull-up techniques, thus discussing potential injury implications. An observational study was performed with eleven participants (age=26.8±2.4 years) who regularly perform pull-ups. The upward motions of three pull-up techniques were analysed: palms facing anterior, palms facing posterior and wide-grip. A skin-fixed scapula tracking technique with attached retro-reflective markers was used. High intra-participant repeatability was observed: mean coefficients of multiple correlations of 0.87-1.00 in humerothoracic rotations and 0.77-0.90 for scapulothoracic rotations. Standard deviations of hand force was low: kinematics were observed between the pull-up techniques. The reverse technique has extreme glenohumeral internal-external rotation and large deviation from the scapula plane. The wide technique has a reduced range of pro/retraction in the same HT plane of elevation and 90° of arm abduction with 45° external rotation was observed. All these factors suggest increased sub-acromial impingement risk. The scapula tracking technique showed high repeatability. High arm elevation during pull-ups reduces sub-acromial space and increases pressure, increasing the risk of impingement injury. Wide and reverse pull-ups demonstrate kinematics patterns linked with increased impingement risk. Weight-assisted front pull-ups require further investigation and could be recommended for weaker participants. Copyright © 2015 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

Analysis of failed rotator cuff repair – Retrospective survey of revisions after open rotator cuff repair

Directory of Open Access Journals (Sweden)

Rupert Schupfner

2017-07-01

Full Text Available Background Rotator cuff defects are frequently occurring shoulder pathologies associated with pain and movement impairment. Aims The aim of the study was to analyse the pathologies that lead to operative revisions after primary open rotator cuff repair. Methods In 216 patients who underwent primary rotator cuff repair and later required operative revision between 1996 to 2005, pathologies found intraoperatively during the primary operation and during revision surgery were collected, analysed and compared. Results The average age at the time of revision surgery was 54.3 years. The right shoulder (61.6 per cent was more often affected than the left, males (63.4 per cent more often than females. At primary operation – apart from rotator cuff repair – there were the following surgical procedures performed: 190 acromioplasty, 86 Acromiclavicular joint resections, 68 tenodesis, 40 adhesiolysis and 1 tenotomy. If an ACJ-resection had been performed in the primary operation, ACJ-problems were rare in revision surgery (p<0.01. Primary gleno-humeral adhesions were associated with a significant rise in re-tearing rate (p=0.049. Primary absence of adhesions went along with a significant lower rate of adhesions found at revision (p=0.018. Primary performed acromioplasty had no influence on re-tearing rate (p=0.408 or on the rate of subacromial impingement at revision surgery (p=0.709. Conclusion To avoid operative revision after rotator cuff repair relevant copathologies of the shoulder have to be identified before or during operation and treated accordingly. Therefore, even during open rotator cuff repair, the surgeon should initially start with arthroscopy of the shoulder joint and subacromial space to recognise co-pathologies.

National space policy of the United States.

Science.gov (United States)

2010-06-28

The space age began as a race for security and prestige between two superpowers . The opportunities : were boundless, and the decades that followed have seen a radical transformation in the way we live our : daily lives, in large part due to our use ...

Can we close large prosthetic space with orthodontics?

Science.gov (United States)

Mesko, Mauro Elias; Skupien, Jovito Adiel; Valentini, Fernanda; Pereira-Cenci, Tatiana

2013-01-01

For years, the treatment for the replacement of a missing tooth was a fixed dental prosthesis. Currently, implants are indicated to replace missing teeth due to high clinical success and with the advantage of not performing preparations in the adjacent tooth. Another option for space closure is the use of orthodontics associated to miniscrews for anchorage allowing better control of the orthodontic biomechanics and especially making possible closure of larger prosthetic spaces. Thus, this article describes two cases with indications and discussion of the advantages and disadvantages of using orthodontics for prosthetic spaces closure. The cases herein presented show that it is possible to close an space when there are available teeth in the adjacent area. It can be concluded that when a malocclusion is present there will be a strong trend to indicate space closure by orthodontic movement as it preserves natural teeth and seems a more physiological approach.

Evaluation of space environmental effects on metals and optical thin films on EOIM-3

Energy Technology Data Exchange (ETDEWEB)

Vaughn, J.A.; Linton, R.C.; Finckenor, M.M.; Kamenetzky, R.R.

1995-02-01

Metals and optical thin films exposed to the space environment on the Third Flight of the Evaluation of Oxygen Interactions with Materials (EOIM-3) payload, onboard Space Shuttle mission STS-46 were evaluated. The materials effects described in this paper include the effects of space exposure on various pure metals, optical thin films, and optical thin film metals. The changes induced by exposure to the space environment in the material properties were evaluated using bidirectional reflectance distribution function (BRDF), specular reflectance (250 nm to 2500 nm), ESCA, VUV reflectance (120 nm to 200 nm), ellipsometry, FTIR and optical properties. Using these analysis techniques gold optically thin film metal mirrors with nickel undercoats were observed to darken due to nickel diffusion through the gold to the surface. Also, thin film nickel mirrors formed nickel oxide due to exposure to both the atmosphere and space.

Evaluation of space environmental effects on metals and optical thin films on EOIM-3

Science.gov (United States)

Vaughn, Jason A.; Linton, Roger C.; Finckenor, Miria M.; Kamenetzky, Rachel R.

1995-01-01

Metals and optical thin films exposed to the space environment on the Third Flight of the Evaluation of Oxygen Interactions with Materials (EOIM-3) payload, onboard Space Shuttle mission STS-46 were evaluated. The materials effects described in this paper include the effects of space exposure on various pure metals, optical thin films, and optical thin film metals. The changes induced by exposure to the space environment in the material properties were evaluated using bidirectional reflectance distribution function (BRDF), specular reflectance (250 nm to 2500 nm), ESCA, VUV reflectance (120 nm to 200 nm), ellipsometry, FTIR and optical properties. Using these analysis techniques gold optically thin film metal mirrors with nickel undercoats were observed to darken due to nickel diffusion through the gold to the surface. Also, thin film nickel mirrors formed nickel oxide due to exposure to both the atmosphere and space.

Lightweight CNT Shielded Cables for Space Applications, Phase II

Data.gov (United States)

National Aeronautics and Space Administration — The effects of electromagnetic interactions in electrical systems are of growing concern due to the increasing susceptibility of system components to electromagnetic...

A primer on Hilbert space theory linear spaces, topological spaces, metric spaces, normed spaces, and topological groups

CERN Document Server

Alabiso, Carlo

2015-01-01

This book is an introduction to the theory of Hilbert space, a fundamental tool for non-relativistic quantum mechanics. Linear, topological, metric, and normed spaces are all addressed in detail, in a rigorous but reader-friendly fashion. The rationale for an introduction to the theory of Hilbert space, rather than a detailed study of Hilbert space theory itself, resides in the very high mathematical difficulty of even the simplest physical case. Within an ordinary graduate course in physics there is insufficient time to cover the theory of Hilbert spaces and operators, as well as distribution theory, with sufficient mathematical rigor. Compromises must be found between full rigor and practical use of the instruments. The book is based on the author's lessons on functional analysis for graduate students in physics. It will equip the reader to approach Hilbert space and, subsequently, rigged Hilbert space, with a more practical attitude. With respect to the original lectures, the mathematical flavor in all sub...

Psychological aspects of living in space - architectural challenges

Science.gov (United States)

Häuplik, Sandra; Lorenz, Susanne

2002-10-01

Space missions have generally involved crews, drawn from a highly homogeneous pool (such as white, educated, young adult males) and functioned for limited periods of time. Future missions may involve crews drawn from a more heterogeneous pool and missions could eventually last years. 3 to 5-person groups are considered appropriate for the Space Shuttle and the first interplanetry missions. In addition to the above mentioned topics the success of a mission will no longer be dependent only on safety issues due to technological progress, but sociological and psychological aspects will become important determinants off the success or failure of future space missions. To create and ensure the social and psychological balance an adequate spatial planning is essential. In the following essay notions for a conception basis of designing a space station will be described.

The Diagnostic Reproducibility of Tomosynthesis for the Correlation between Acromiohumeral Distance and Rotator Cuff Size or Type.

Science.gov (United States)

Song, Yoonah; Lee, Seunghun; Lee, Bong Gun; Joo, Young Bin; Song, Soon-Young

2018-01-01

To correlate the acromiohumeral distance (AHD) using tomosynthesis and rotator cuff (RC) pathology and various anatomical indices and to assess the diagnostic reproducibility of tomosynthesis for the evaluation of subacromial impingement. A retrospective review of 63 patients with clinically suspected subacromial impingement was conducted. Two musculoskeletal radiologists independently measured the following quantitative data: the AHD on plain radiographs and the AHD at three compartments (anterior, middle, and posterior) using tomosynthesis, computed tomography (CT) arthrography, or magnetic resonance (MR) arthrography. To investigate the association between the AHD and RC pathology and various anatomical indices, we reviewed the arthroscopic operation record as the referenced standard. The size of rotator cuff tear (RCT) in full-thickness tears displayed a significant inverse correlation with the middle and the posterior tomosynthetic AHDs ( p tomosynthesis, and CT or MR arthrography ( p tomosynthesis is reproducible compared with other modalities.

Nutritional Biochemistry of Space Flight

Science.gov (United States)

Smith, Scott M.

2000-01-01

space flight. This is critical due to the red blood cell changes which occur, and the increase in iron storage that has been observed after space flight. The Iron Absorption and Metabolism experiment is currently planned for long-term flights on the International Space Station.

Blue Light for Enhancing Alertness in Space Missions

Data.gov (United States)

National Aeronautics and Space Administration — This is the final year of a directed research project that had reduced aims due to an unexpected funding reduction. The goal is to study the efficacy of blue or...

Graphite epoxy composite degradation by space radiation

International Nuclear Information System (INIS)

Taheri, M.; Sandquist, G.M.; Slaughter, D.M.; Bennion, J.

1991-01-01

The radiation environment in space is a critical consideration for successful operation in space. All manned space missions with a duration of more than a few days are subjected to elevated ionizing radiation exposures, which are a threat to both personnel and structures in space. The increasing demands for high-performance materials as structural components in the aerospace, aircraft, and defense industries have led to the development of materials such as graphite fiber-reinforced, epoxy resin matrix composites (Gr/Ep). These materials provide important advantages over conventional structural materials, such as ultrahigh specific strength, enhanced specific moduli, and better fatigue resistance. The fact that most advanced composite materials under cyclic fatigue loading evidence little or no observable crack growth prior to rapid fracture suggests that for fail-safe considerations of parts subject to catastrophic failure, a detailed evaluation of radiation damage from very energetic particle is crucial. The Gr/Ep components are believed to suffer severe degradation in space due to highly penetrating secondary radiation, mainly from neutrons and protons. Investigation into the performance and stability of Gr/Ep materials are planned

Emergent gravity in spaces of constant curvature

Energy Technology Data Exchange (ETDEWEB)

Alvarez, Orlando; Haddad, Matthew [Department of Physics, University of Miami,1320 Campo Sano Ave, Coral Gables, FL 33146 (United States)

2017-03-07

In physical theories where the energy (action) is localized near a submanifold of a constant curvature space, there is a universal expression for the energy (or the action). We derive a multipole expansion for the energy that has a finite number of terms, and depends on intrinsic geometric invariants of the submanifold and extrinsic invariants of the embedding of the submanifold. This is the second of a pair of articles in which we try to develop a theory of emergent gravity arising from the embedding of a submanifold into an ambient space equipped with a quantum field theory. Our theoretical method requires a generalization of a formula due to by Hermann Weyl. While the first paper discussed the framework in Euclidean (Minkowski) space, here we discuss how this framework generalizes to spaces of constant sectional curvature. We focus primarily on anti de Sitter space. We then discuss how such a theory can give rise to a cosmological constant and Planck mass that are within reasonable bounds of the experimental values.

he First Superconductivity Experiment in Space

International Nuclear Information System (INIS)

Polturak, E.; Koren, G.

1999-01-01

One of the most promising applications of high Tc superconductors is in the field of satellite communications. In view of the rapidly increasing demand for satellite communication channels due to the formation of global networks of cellular phones, internet, etc., one needs to (develop more efficient ways of dividing the finite frequency band into more and more channels without paying for it with excessive interference or an increasingly large weight of conventional filters. Superconductive components can save an order of magnitude on the weight and volume of such filters, a very important factor in satellite design. Yet, up to now superconductors were never tested in space. We present the design and performance of the first such experiment to reach space. The experiment consists of a thin film HTSC device integrated with a miniature cryo cooler. It was launched into space in July 1998 aboard the Thatch's-II micro satellite. We will present data obtained from this experiment until the present time. Long term survivability of HTSC devices in space would be discussed

Use of small public urban green spaces (SPUGS)

DEFF Research Database (Denmark)

Peschardt, Karin Kragsig; Schipperijn, Jasper; Stigsdotter, Ulrika K.

2012-01-01

which environmental characteristics users prefer in relation to mental restoration. We investigate nine small public urban green spaces (SPUGS) in the dense city of Copenhagen in order to determine which environmental characteristics may influence the perceived restorativeness of SPUGS amongst average......UGS have been positively associated with stress-related illnesses. Paradoxically the densification tendency in western cities causes decreasing access to green environments. City planners and landscape architects are challenged when designing such areas due to a lack of space and knowledge about...

Clinical and radiological outcome of conservative vs. surgical treatment of atraumatic degenerative rotator cuff rupture : design of a randomized controlled trial

NARCIS (Netherlands)

Heerspink, Frederik O. Lambers; Hoogeslag, Roy A. G.; Diercks, Ron L.; van Eerden, Pepijn J. M.; van den Akker-Scheek, Inge; van Raay, Jos J. A. M.

2011-01-01

Background: Subacromial impingement syndrome is a frequently observed disorder in orthopedic practice. Lasting symptoms and impairment may occur when a subsequent atraumatic rotator cuff rupture is also present. However, degenerative ruptures of the rotator cuff can also be observed in asymptomatic

Space sickness on earth

Science.gov (United States)

Nooij, S. A. E.; Bos, J. E.; Groen, E. L.; Bles, W.; Ockels, W. J.

2007-09-01

During the first days in space, i.e., after a transition from 1G to 0G, more than 50% of the astro- (and cosmonauts) suffer from the Space Adaptation Syndrome (SAS).The symptoms of SAS, like nausea and dizziness, are especially provoked by head movements. Astronauts have mentioned close similarities between the symptoms of SAS and the symptoms they experienced after a 1 hour centrifuge run on Earth, i.e., after a transition from 3G to 1G (denoted by Sickness Induced by Centrifugation, SIC). During several space missions, we related susceptibility to SAS and to SIC in 11 astronauts and found 4 of them being susceptible to both SIC and SAS, and 7 being not susceptible to SIC nor to SAS. This correspondence in susceptibility suggests that SIC and SAS share the same underlying mechanism. To further study this mechanism, several vestibular parameters have been investigated (e.g. postural stability, vestibularly driven eye movements, subjective vertical). We found some striking changes in individual cases that are possibly due to the centrifuge run. However, the variability between subjects generally is very large, making physiological links to SIC and SAS still hard to find.

Radiation protection considerations in space station missions

International Nuclear Information System (INIS)

Peddicord, K.L.; Bolch, W.E.

1991-01-01

The National Aeronautics and Space Administration (NASA) is currently studying the degree to which the baseline design of space station Freedom (SSF) would permit its evolution to a transportation node for lunar or Mars expeditions. To accomplish NASA's more ambitious exploration goals, nuclear-powered vehicles could be used in SSF's vicinity. This enhanced radiation environment around SSF could necessitate additional crew shielding to maintain cumulative doses below recommended limits. This paper presents analysis of radiation doses received upon the return and subsequent unloading of Mars vehicles utilizing either nuclear electric propulsion (NEP) or nuclear thermal rocket (NTR) propulsion systems. No inherent shielding by the vehicle structure or space station is assumed; consequently, the only operational parameters available to control radiation doses are the source-to-target distance and the reactor shutdown time prior to the exposure period. For the operations planning, estimated doses are shown with respect to recommended dose limits and doses due solely to the natural space environment in low Earth orbit

Toward Microsatellite Based Space Situational Awareness

Science.gov (United States)

Scott, L.; Wallace, B.; Sale, M.; Thorsteinson, S.

2013-09-01

. The placement of a space based space surveillance sensor in low Earth orbit introduces tasking and image processing complexities such as cosmic ray rejection, scattered light from Earth's limb and unique scheduling limitations due to the observer's rapid positional change and we describe first-look microsatellite space surveillance lessons from this unique orbital vantage point..

Wastes in space; Les dechets dans l'espace

Energy Technology Data Exchange (ETDEWEB)

NONE

2011-07-01

As human space activities have created more wastes on low and high Earth orbits over the past 50 years than the solar system injected meteorites over billions of years, this report gives an overview of this problem. It identifies the origins of these space debris and wastes (launchers, combustion residues, exploitation wastes, out-of-use satellites, accidental explosions, accidental collisions, voluntary destructions, space erosion), and proposes a stock list of space wastes. Then, it distinguishes the situation for the different orbits: low Earth orbit or LEO (traffic, presence of the International Space Station), medium Earth orbits or MEO (traffic, operating satellites, wastes), geostationary Earth orbit or GEO (traffic, operating satellites, wastes). It also discusses wastes and bacteria present on the moon (due to Apollo missions or to crash tests). It evokes how space and nuclear industry is concerned, and discusses the re-entry issue (radioactive boomerang, metallic boomerang). It also indicates elements of international law

Evolution of space drones for planetary exploration: A review

Science.gov (United States)

Hassanalian, M.; Rice, D.; Abdelkefi, A.

2018-02-01

In the past decade, there has been a tendency to design and fabricate drones which can perform planetary exploration. Generally, there are various ways to study space objects, such as the application of telescopes and satellites, launching robots and rovers, and sending astronauts to the targeted solar bodies. However, due to the advantages of drones compared to other approaches in planetary exploration, ample research has been carried out by different space agencies in the world, including NASA to apply drones in other solar bodies. In this review paper, several studies which have been performed on space drones for planetary exploration are consolidated and discussed. Design and fabrication challenges of space drones, existing methods for their flight tests, different methods for deployment and planet entry, and various navigation and control approaches are reviewed and discussed elaborately. Limitations of applying space drones, proposed solutions for future space drones, and recommendations are also presented and discussed.

A relativistic self-consistent model for studying enhancement of space charge limited field emission due to counter-streaming ions

International Nuclear Information System (INIS)

Lin, M. C.; Lu, P. S.; Chang, P. C.; Ragan-Kelley, B.; Verboncoeur, J. P.

2014-01-01

Recently, field emission has attracted increasing attention despite the practical limitation that field emitters operate below the Child-Langmuir space charge limit. By introducing counter-streaming ion flow to neutralize the electron charge density, the space charge limited field emission (SCLFE) current can be dramatically enhanced. In this work, we have developed a relativistic self-consistent model for studying the enhancement of SCLFE by a counter-streaming ion current. The maximum enhancement is found when the ion effect is saturated, as shown analytically. The solutions in non-relativistic, intermediate, and ultra-relativistic regimes are obtained and verified with 1-D particle-in-cell simulations. This self-consistent model is general and can also serve as a benchmark or comparison for verification of simulation codes, as well as extension to higher dimensions

Space-charge Effect on Electroresistance in Metal-Ferroelectric-Metal capacitors

Science.gov (United States)

Tian, Bo Bo; Liu, Yang; Chen, Liu Fang; Wang, Jian Lu; Sun, Shuo; Shen, Hong; Sun, Jing Lan; Yuan, Guo Liang; Fusil, Stéphane; Garcia, Vincent; Dkhil, Brahim; Meng, Xiang Jian; Chu, Jun Hao

2015-12-01

Resistive switching through electroresistance (ER) effect in metal-ferroelectric-metal (MFM) capacitors has attracted increasing interest due to its potential applications as memories and logic devices. However, the detailed electronic mechanisms resulting in large ER when polarisation switching occurs in the ferroelectric barrier are still not well understood. Here, ER effect up to 1000% at room temperature is demonstrated in C-MOS compatible MFM nanocapacitors with a 8.8 nm-thick poly(vinylidene fluoride) (PVDF) homopolymer ferroelectric, which is very promising for silicon industry integration. Most remarkably, using theory developed for metal-semiconductor rectifying contacts, we derive an analytical expression for the variation of interfacial barrier heights due to space-charge effect that can interpret the observed ER response. We extend this space-charge model, related to the release of trapped charges by defects, to MFM structures made of ferroelectric oxides. This space-charge model provides a simple and straightforward tool to understand recent unusual reports. Finally, this work suggests that defect-engineering could be an original and efficient route for tuning the space-charge effect and thus the ER performances in future electronic devices.

A Dynamic Risk Model for Evaluation of Space Shuttle Abort Scenarios

Science.gov (United States)

Henderson, Edward M.; Maggio, Gaspare; Elrada, Hassan A.; Yazdpour, Sabrina J.

2003-01-01

The Space Shuttle is an advanced manned launch system with a respectable history of service and a demonstrated level of safety. Recent studies have shown that the Space Shuttle has a relatively low probability of having a failure that is instantaneously catastrophic during nominal flight as compared with many US and international launch systems. However, since the Space Shuttle is a manned. system, a number of mission abort contingencies exist to primarily ensure the safety of the crew during off-nominal situations and to attempt to maintain the integrity of the Orbiter. As the Space Shuttle ascends to orbit it transverses various intact abort regions evaluated and planned before the flight to ensure that the Space Shuttle Orbiter, along with its crew, may be returned intact either to the original launch site, a transoceanic landing site, or returned from a substandard orbit. An intact abort may be initiated due to a number of system failures but the highest likelihood and most challenging abort scenarios are initiated by a premature shutdown of a Space Shuttle Main Engine (SSME). The potential consequences of such a shutdown vary as a function of a number of mission parameters but all of them may be related to mission time for a specific mission profile. This paper focuses on the Dynamic Abort Risk Evaluation (DARE) model process, applications, and its capability to evaluate the risk of Loss Of Vehicle (LOV) due to the complex systems interactions that occur during Space Shuttle intact abort scenarios. In addition, the paper will examine which of the Space Shuttle subsystems are critical to ensuring a successful return of the Space Shuttle Orbiter and crew from such a situation.

Space debris: modeling and detectability

Science.gov (United States)

Wiedemann, C.; Lorenz, J.; Radtke, J.; Kebschull, C.; Horstmann, A.; Stoll, E.

2017-01-01

High precision orbit determination is required for the detection and removal of space debris. Knowledge of the distribution of debris objects in orbit is necessary for orbit determination by active or passive sensors. The results can be used to investigate the orbits on which objects of a certain size at a certain frequency can be found. The knowledge of the orbital distribution of the objects as well as their properties in accordance with sensor performance models provide the basis for estimating the expected detection rates. Comprehensive modeling of the space debris environment is required for this. This paper provides an overview of the current state of knowledge about the space debris environment. In particular non-cataloged small objects are evaluated. Furthermore, improvements concerning the update of the current space debris model are addressed. The model of the space debris environment is based on the simulation of historical events, such as fragmentations due to explosions and collisions that actually occurred in Earth orbits. The orbital distribution of debris is simulated by propagating the orbits considering all perturbing forces up to a reference epoch. The modeled object population is compared with measured data and validated. The model provides a statistical distribution of space objects, according to their size and number. This distribution is based on the correct consideration of orbital mechanics. This allows for a realistic description of the space debris environment. Subsequently, a realistic prediction can be provided concerning the question, how many pieces of debris can be expected on certain orbits. To validate the model, a software tool has been developed which allows the simulation of the observation behavior of ground-based or space-based sensors. Thus, it is possible to compare the results of published measurement data with simulated detections. This tool can also be used for the simulation of sensor measurement campaigns. It is

State-space prediction model for chaotic time series

Science.gov (United States)

Alparslan, A. K.; Sayar, M.; Atilgan, A. R.

1998-08-01

A simple method for predicting the continuation of scalar chaotic time series ahead in time is proposed. The false nearest neighbors technique in connection with the time-delayed embedding is employed so as to reconstruct the state space. A local forecasting model based upon the time evolution of the topological neighboring in the reconstructed phase space is suggested. A moving root-mean-square error is utilized in order to monitor the error along the prediction horizon. The model is tested for the convection amplitude of the Lorenz model. The results indicate that for approximately 100 cycles of the training data, the prediction follows the actual continuation very closely about six cycles. The proposed model, like other state-space forecasting models, captures the long-term behavior of the system due to the use of spatial neighbors in the state space.

Measuring space-time fuzziness with high energy γ-ray detectors

Directory of Open Access Journals (Sweden)

Cattaneo Paolo Walter

2017-01-01

Full Text Available There are several suggestions to probe space-time fuzziness (also known as space-time foam due to the quantum mechanics nature of space-time. These effects are predicted to be very small, being related to the Planck length, so that the only hope to experimentally detect them is to look at particles propagating along cosmological distances. Some phenomenological approaches suggest that photons originating from pointlike sources at cosmological distance experience path length fluctuation that could be detected. Also the direction of flight of such photons may be subject to a dispersion such that the image of a point-like source is blurred and detected as a disk. An experimentally accessible signature may be images of point-like sources larger that the size due to the Point Spread Function of the instrument. This additional broadening should increase with distance and photon energy. Some concrete examples that can be studied with the AGILE and FERMI-LAT γ -ray satellite experiments are discussed.

Phase space view of quantum mechanical systems and Fisher information

Energy Technology Data Exchange (ETDEWEB)

Nagy, Á., E-mail: anagy@madget.atomki.hu

2016-06-17

Highlights: • Phase-space Fisher information coming from the canonical distribution is derived for the ground state of quantum mechanical systems. • Quantum mechanical phase-space Fisher information contains an extra term due to the position dependence of the temperature. • A complete analogy to the classical case is demonstrated for the linear harmonic oscillator. - Abstract: Pennini and Plastino showed that the form of the Fisher information generated by the canonical distribution function reflects the intrinsic structure of classical mechanics. Now, a quantum mechanical generalization of the Pennini–Plastino theory is presented based on the thermodynamical transcription of the density functional theory. Comparing to the classical case, the phase-space Fisher information contains an extra term due to the position dependence of the temperature. However, for the special case of constant temperature, the expression derived bears resemblance to the classical one. A complete analogy to the classical case is demonstrated for the linear harmonic oscillator.

Phase space view of quantum mechanical systems and Fisher information

International Nuclear Information System (INIS)

Nagy, Á.

2016-01-01

Highlights: • Phase-space Fisher information coming from the canonical distribution is derived for the ground state of quantum mechanical systems. • Quantum mechanical phase-space Fisher information contains an extra term due to the position dependence of the temperature. • A complete analogy to the classical case is demonstrated for the linear harmonic oscillator. - Abstract: Pennini and Plastino showed that the form of the Fisher information generated by the canonical distribution function reflects the intrinsic structure of classical mechanics. Now, a quantum mechanical generalization of the Pennini–Plastino theory is presented based on the thermodynamical transcription of the density functional theory. Comparing to the classical case, the phase-space Fisher information contains an extra term due to the position dependence of the temperature. However, for the special case of constant temperature, the expression derived bears resemblance to the classical one. A complete analogy to the classical case is demonstrated for the linear harmonic oscillator.

Radiation hardened high efficiency silicon space solar cell

International Nuclear Information System (INIS)

Garboushian, V.; Yoon, S.; Turner, J.

1993-01-01

A silicon solar cell with AMO 19% Beginning of Life (BOL) efficiency is reported. The cell has demonstrated equal or better radiation resistance when compared to conventional silicon space solar cells. Conventional silicon space solar cell performance is generally ∼ 14% at BOL. The Radiation Hardened High Efficiency Silicon (RHHES) cell is thinned for high specific power (watts/kilogram). The RHHES space cell provides compatibility with automatic surface mounting technology. The cells can be easily combined to provide desired power levels and voltages. The RHHES space cell is more resistant to mechanical damage due to micrometeorites. Micro-meteorites which impinge upon conventional cells can crack the cell which, in turn, may cause string failure. The RHHES, operating in the same environment, can continue to function with a similar crack. The RHHES cell allows for very efficient thermal management which is essential for space cells generating higher specific power levels. The cell eliminates the need for electrical insulation layers which would otherwise increase the thermal resistance for conventional space panels. The RHHES cell can be applied to a space concentrator panel system without abandoning any of the attributes discussed. The power handling capability of the RHHES cell is approximately five times more than conventional space concentrator solar cells

Minimizing Warehouse Space through Inventory Reduction at Reckitt Benckiser

OpenAIRE

KILINC, IZGI SELEN

2009-01-01

This dissertation represents a ten week internship at pharmaceutical plant of Reckitt Benckiser for the Warehouse Stock Reduction Project. Due to foreseeable growth by the factory, there is increasing pressure to utilise existing warehouse space by reducing the existing stock level by 50 %. Therefore, this study aims to identify the opportunities to reduce the physical stock held in raw/pack materials in the warehouse and save space for additional manufacturing resources. The analysis demo...

Image Segmentation and Processing for Efficient Parking Space Analysis

OpenAIRE

Tutika, Chetan Sai; Vallapaneni, Charan; R, Karthik; KP, Bharath; Muthu, N Ruban Rajesh Kumar

2018-01-01

In this paper, we develop a method to detect vacant parking spaces in an environment with unclear segments and contours with the help of MATLAB image processing capabilities. Due to the anomalies present in the parking spaces, such as uneven illumination, distorted slot lines and overlapping of cars. The present-day conventional algorithms have difficulties processing the image for accurate results. The algorithm proposed uses a combination of image pre-processing and false contour detection ...

Nonlocality and Multipartite Entanglement in Asymptotically Flat Space-Times

International Nuclear Information System (INIS)

Moradi, Shahpoor; Amiri, Firouz

2016-01-01

We study the Bell's inequality and multipartite entanglement generation for initially maximally entangled states of free Dirac field in a non inertial frame and asymptotically flat Robertson–Walker space-time. For two qubit case, we show that the Bell's inequality always is violated as measured by the accelerated observers which are in the causally connected regions. On the other hand, for those observers in the causally disconnected regions inequality is not violated for any values of acceleration. The generated three qubit state from two qubit state due to acceleration of one parties has a zero 3-tangle. For a three qubit state, the inequality violated for measurements done by both causally connected and disconnected observers. Initially GHZ state with non zero 3-tangle, in accelerated frame, transformed to a four qubit state with vanishing 4-tangle value. On the other hand, for a W-state with zero 3-tangle, in non inertial frame, transformed to a four qubit state with a non-zero 4-tangle acceleration dependent. In an expanding space-time with asymptotically flat regions, for an initially maximally entangled state, the maximum value of violation of Bell's inequality in the far past decreased in the far future due to cosmological particle creation. For some initially maximally entangled states, the generated four qubit state due to expansion of space-time, has non vanishing 4-tangle. (paper)

Portable, parallel, reusable Krylov space codes

Energy Technology Data Exchange (ETDEWEB)

Smith, B.; Gropp, W. [Argonne National Lab., IL (United States)

1994-12-31

Krylov space accelerators are an important component of many algorithms for the iterative solution of linear systems. Each Krylov space method has it`s own particular advantages and disadvantages, therefore it is desirable to have a variety of them available all with an identical, easy to use, interface. A common complaint application programmers have with available software libraries for the iterative solution of linear systems is that they require the programmer to use the data structures provided by the library. The library is not able to work with the data structures of the application code. Hence, application programmers find themselves constantly recoding the Krlov space algorithms. The Krylov space package (KSP) is a data-structure-neutral implementation of a variety of Krylov space methods including preconditioned conjugate gradient, GMRES, BiCG-Stab, transpose free QMR and CGS. Unlike all other software libraries for linear systems that the authors are aware of, KSP will work with any application codes data structures, in Fortran or C. Due to it`s data-structure-neutral design KSP runs unchanged on both sequential and parallel machines. KSP has been tested on workstations, the Intel i860 and Paragon, Thinking Machines CM-5 and the IBM SP1.

Magnetic fluctuations due to thermally excited Alfven waves

International Nuclear Information System (INIS)

Agim, Y.Z.; Prager, S.C.

1990-01-01

Magnetic fluctuations due to the thermally excited MHD waves are investigated using fluid and kinetic models to describe a stable, uniform, compressible plasma in the range above the drift wave frequency and below the ion cyclotron frequency. It is shown that the fluid model with resistivity yields spectral densities which are roughly Lorentzian, exhibit equipartition with no apparent cutoff in wavenumber space and a Bohm-type diffusion coefficient. Under certain conditions, the ensuing transport may be comparable to classical values. For a phenomenological cutoff imposed on the spectrum, the typical fluctuating-to-equilibrium magnetic field ratio is found to be of the order of 10 -10 . Physical mechanisms to obtain decay profiles of the spectra with increasing wavenumber due to dispersion and/or different forms of damping are investigated analytically in a cold fluid approximation and numerically, with a kinetic model. The mode dispersion due to the finite ion-gyrofrequency is identified as the leading effect determining the spectral profile shapes. It is found that the amplitude of fluctuations may be within a factor of the value suggested by the cold plasma model. The results from both models are presented and compared in low- and high-β regimes. 21 refs., 6 figs

Early space symmetry restoration and neutrino experiments

International Nuclear Information System (INIS)

Volkov, G.G.; Liparteliani, A.G.; Monich, V.A.

1986-01-01

The problem of early space symmetry restoration on the left-right symmetry models and the models with the extended (due to mirror quarks and leptons) fermion sector is being discussed. The experiments in which the derivations from the standard model of electroweak interactions should be studied are presented

Principal normal indicatrices of closed space curves

DEFF Research Database (Denmark)

Røgen, Peter

1999-01-01

A theorem due to J. Weiner, which is also proven by B. Solomon, implies that a principal normal indicatrix of a closed space curve with nonvanishing curvature has integrated geodesic curvature zero and contains no subarc with integrated geodesic curvature pi. We prove that the inverse problem alw...

Cosmic rays in space

International Nuclear Information System (INIS)

Fujitaka, Kazunobu

2005-01-01

Cosmos is a mysterious space by which many researchers are fascinated for many years. But, going into space means that we will receive extra exposure due to existence of cosmic rays. Cosmic rays are mainly composed of highly energetic protons. It was born in the last stage of stellar life. Understanding of cosmos will certainly bring right understanding of radiation energy, or energy itself. As no one could see the very early stage of cosmic rays, there is only a speculation. But it is better to speculate something based on certain side evidences, than to give up the whole. Such attitude shall be welcomed in the space researches. Anyway, cosmic rays were born in the last explosion of a star, which is called as Super Nova. After cosmic rays are emitted from the Super Nova, it will reach to the human surroundings. To indicate its intensity, special unit of ''dose rate'' is used. When a man climbs a mountain, cosmic ray intensity surely increases. It doubles as he goes up every 1500m elevation. It was ascertained by our own measurements. Then what happens when the goes up more? At aviation altitude, where airplanes fly, the dose rate will be increased up to 100times the high mountain cases. And what is expected when he goes up further more, up to space orbit altitude? In this case, the dose rate increases up to 10times the airplane cases. Geomagnetism affects the dose rate very much. As primary cosmic ray particles are charged particles, they cannot do well with existence of the magnetic field. In effect, cosmic rays can penetrate into the polar atmosphere along geomagnetic lines of forces which stand almost vertical, but penetration of low energy cosmic rays will be banned when they intend to penetrate crossing the geomagnetic lines of forces in equatorial region. Therefore, exposure due to cosmic rays will become large in polar region, while it remains small in equatorial region. In effect, airplanes which fly over the equator. Only, we have to know that the cosmos

Human Pathophysiological Adaptations to the Space Environment

Directory of Open Access Journals (Sweden)

Gian C. Demontis

2017-08-01

Full Text Available Space is an extreme environment for the human body, where during long-term missions microgravity and high radiation levels represent major threats to crew health. Intriguingly, space flight (SF imposes on the body of highly selected, well-trained, and healthy individuals (astronauts and cosmonauts pathophysiological adaptive changes akin to an accelerated aging process and to some diseases. Such effects, becoming manifest over a time span of weeks (i.e., cardiovascular deconditioning to months (i.e., loss of bone density and muscle atrophy of exposure to weightlessness, can be reduced through proper countermeasures during SF and in due time are mostly reversible after landing. Based on these considerations, it is increasingly accepted that SF might provide a mechanistic insight into certain pathophysiological processes, a concept of interest to pre-nosological medicine. In this article, we will review the main stress factors encountered in space and their impact on the human body and will also discuss the possible lessons learned with space exploration in reference to human health on Earth. In fact, this is a productive, cross-fertilized, endeavor in which studies performed on Earth yield countermeasures for protection of space crew health, and space research is translated into health measures for Earth-bound population.

An evolving joint space campaign concept and the Army's role

Science.gov (United States)

Franke, Henry G., III

1992-05-01

This monograph examines the question of an evolving joint space campaign concept and the Army's role in it over the next 20 years. Analysis progresses logically through a series of topics in order to arrive at a complete picture of this evolutionary space campaign concept, as well as the Army's place in it. Space plays an increasingly important role in US military operations, particularly when tied together with advances in information management. The synergistic impact due to the combination of these two areas suggests a revolution in the nature of modern warfare which saw its emergence during the 1991 Gulf War. With this theme in mind, I review the Army's roles, missions, and historical involvement in space, then present technological opportunities and a perspective on investment strategies for military space. A detailed discussion of a near-term military space theory and current space doctrines supports the need for an accepted military space theory as a foundation for Joint and Service space doctrines, space campaign design and conduct, and space force generation. The basis for such a theory is established using Julian Corbett's maritime warfare theory as a point of departure, while recognizing that space as a unique military operating medium requires its own theory and a regime to govern the application of space forces.

Ratchet due to broken friction symmetry

DEFF Research Database (Denmark)

Norden, Bengt; Zolotaryuk, Yaroslav; Christiansen, Peter Leth

2002-01-01

A ratchet mechanism that occurs due to asymmetric dependence of the friction of a moving system on its velocity or a driving force is reported. For this kind of ratchet, instead of a particle moving in a periodic potential, the dynamics of which have broken space-time symmetry, the system must...... be provided with sonic internal structure realizing such a velocity- or force-friction dependence. For demonstration of a ratchet mechanism of this type, an experimental setup (gadget) that converts longitudinal oscillating or fluctuating motion into a unidirectional rotation has been built and experiments...... with it have been carried out. In this device, an asymmetry of friction dependence on an applied force appears, resulting in rectification of rotary motion, In experiments, our setup is observed to rotate only in one direction, which is in accordance with given theoretical arguments, Despite the setup being...

3D Embedded Reconfigurable Riometer for Heliospheric Space Missions

Science.gov (United States)

Dekoulis, George

2016-07-01

This paper describes the development of a new three-dimensional embedded reconfigurable Riometer for performing remote sensing of planetary magnetospheres. The system couples the in situ measurements of probe or orbiter magnetospheric space missions. The new prototype features a multi-frequency mode that allows measurements at frequencies, where heliospheric physics events' signatures are distinct on the ionized planetary plasma. For our planet similar measurements are meaningful for frequencies below 55 MHz. Observation frequencies above 55 MHz yield to direct measurements of the Cosmic Microwave Background intensity. The system acts as a prototyping platform for subsequent space exploration phased-array imaging experiments, due to its high-intensity scientific processing capabilities. The performance improvement over existing systems in operation is in the range of 80%, due to the state-of-the-art hardware and scientific processing used.

Effects of Space Weathering on Reflectance Spectra of Ureilites: A Proof-of-Concept Study

Science.gov (United States)

Goodrich, C. A.; Gillis-Davis, J.; Cloutis, E.; Applin, D.; Hibbits, C.; Klima, R.; Christoffersen, R.; Fries, M.; Decker, S.

2017-07-01

Space weathering and spectral studies of three ureilitic samples show that space weathering causes significant changes in UV-VIS-IR spectra and Raman spectra. Changes due to amorphization of carbon could disguise ureilitic asteroids as CC-like.

Realizing spaces as path-component spaces

OpenAIRE

Banakh, Taras; Brazas, Jeremy

2018-01-01

The path component space of a topological space $X$ is the quotient space $\\pi_0(X)$ whose points are the path components of $X$. We show that every Tychonoff space $X$ is the path-component space of a Tychonoff space $Y$ of weight $w(Y)=w(X)$ such that the natural quotient map $Y\\to \\pi_0(Y)=X$ is a perfect map. Hence, many topological properties of $X$ transfer to $Y$. We apply this result to construct a compact space $X\\subset \\mathbb{R}^3$ for which the fundamental group $\\pi_1(X,x_0)$ is...

Reinforcement learning in continuous state and action spaces

NARCIS (Netherlands)

H. P. van Hasselt (Hado); M.A. Wiering; M. van Otterlo

2012-01-01

textabstractMany traditional reinforcement-learning algorithms have been designed for problems with small finite state and action spaces. Learning in such discrete problems can been difficult, due to noise and delayed reinforcements. However, many real-world problems have continuous state or action

Common fixed point theorems in intuitionistic fuzzy metric spaces and L-fuzzy metric spaces with nonlinear contractive condition

International Nuclear Information System (INIS)

Jesic, Sinisa N.; Babacev, Natasa A.

2008-01-01

The purpose of this paper is to prove some common fixed point theorems for a pair of R-weakly commuting mappings defined on intuitionistic fuzzy metric spaces [Park JH. Intuitionistic fuzzy metric spaces. Chaos, Solitons and Fractals 2004;22:1039-46] and L-fuzzy metric spaces [Saadati R, Razani A, Adibi H. A common fixed point theorem in L-fuzzy metric spaces. Chaos, Solitons and Fractals, doi:10.1016/j.chaos.2006.01.023], with nonlinear contractive condition, defined with function, first observed by Boyd and Wong [Boyd DW, Wong JSW. On nonlinear contractions. Proc Am Math Soc 1969;20:458-64]. Following Pant [Pant RP. Common fixed points of noncommuting mappings. J Math Anal Appl 1994;188:436-40] we define R-weak commutativity for a pair of mappings and then prove the main results. These results generalize some known results due to Saadati et al., and Jungck [Jungck G. Commuting maps and fixed points. Am Math Mon 1976;83:261-3]. Some examples and comments according to the preceding results are given

Space Radiation and Risks to Human Health

Science.gov (United States)

Huff, Janice L.; Patel, Zarana S.; Simonsen, Lisa C.

2014-01-01

The radiation environment in space poses significant challenges to human health and is a major concern for long duration manned space missions. Outside the Earth's protective magnetosphere, astronauts are exposed to higher levels of galactic cosmic rays, whose physical characteristics are distinct from terrestrial sources of radiation such as x-rays and gamma-rays. Galactic cosmic rays consist of high energy and high mass nuclei as well as high energy protons; they impart unique biological damage as they traverse through tissue with impacts on human health that are largely unknown. The major health issues of concern are the risks of radiation carcinogenesis, acute and late decrements to the central nervous system, degenerative tissue effects such as cardiovascular disease, as well as possible acute radiation syndromes due to an unshielded exposure to a large solar particle event. The NASA Human Research Program's Space Radiation Program Element is focused on characterization and mitigation of these space radiation health risks along with understanding these risks in context of the other biological stressors found in the space environment. In this overview, we will provide a description of these health risks and the Element's research strategies to understand and mitigate these risks.

Twistor Cosmology and Quantum Space-Time

International Nuclear Information System (INIS)

Brody, D.C.; Hughston, L.P.

2005-01-01

The purpose of this paper is to present a model of a 'quantum space-time' in which the global symmetries of space-time are unified in a coherent manner with the internal symmetries associated with the state space of quantum-mechanics. If we take into account the fact that these distinct families of symmetries should in some sense merge and become essentially indistinguishable in the unified regime, our framework may provide an approximate description of or elementary model for the structure of the universe at early times. The quantum elements employed in our characterisation of the geometry of space-time imply that the pseudo-Riemannian structure commonly regarded as an essential feature in relativistic theories must be dispensed with. Nevertheless, the causal structure and the physical kinematics of quantum space-time are shown to persist in a manner that remains highly analogous to the corresponding features of the classical theory. In the case of the simplest conformally flat cosmological models arising in this framework, the twistorial description of quantum space-time is shown to be effective in characterising the various physical and geometrical properties of the theory. As an example, a sixteen-dimensional analogue of the Friedmann-Robertson-Walker cosmologies is constructed, and its chronological development is analysed in some detail. More generally, whenever the dimension of a quantum space-time is an even perfect square, there exists a canonical way of breaking the global quantum space-time symmetry so that a generic point of quantum space-time can be consistently interpreted as a quantum operator taking values in Minkowski space. In this scenario, the breakdown of the fundamental symmetry of the theory is due to a loss of quantum entanglement between space-time and internal quantum degrees of freedom. It is thus possible to show in a certain specific sense that the classical space-time description is an emergent feature arising as a consequence of a

Rayleigh wave effects in an elastic half-space.

Science.gov (United States)

Aggarwal, H. R.

1972-01-01

Consideration of Rayleigh wave effects in a homogeneous isotropic linearly elastic half-space subject to an impulsive uniform disk pressure loading. An approximate formula is obtained for the Rayleigh wave effects. It is shown that the Rayleigh waves near the center of loading arise from the portion of the dilatational and shear waves moving toward the axis, after they originate at the edge of the load disk. A study is made of the vertical displacement due to Rayleigh waves at points on the axis near the surface of the elastic half-space.

Space Weather Concerns for All-Electric Propulsion Satellites

Science.gov (United States)

Horne, Richard B.; Pitchford, David

2015-08-01

The introduction of all-electric propulsion satellites is a game changer in the quest for low-cost access to space. It also raises new questions for satellite manufacturers, operators, and the insurance industry regarding the general risks and specifically the threat of adverse space weather. The issues surrounding this new concept were discussed by research scientists and up to 30 representatives from the space industry at a special meeting at the European Space Weather Week held in November 2014. Here we report on the discussions at that meeting. We show that for a satellite undergoing electric orbit raising for 200 days the radiation dose due to electrons is equivalent to approximately 6.7 year operation at geostationary orbit or approximately half the typical design life. We also show that electrons can be injected into the slot region (8000 km) where they pose a risk of satellite internal charging. The results highlight the importance of additional radiation protection. We also discuss the benefits, the operational considerations, the other risks from the Van Allen radiation belts, the new business opportunities for space insurance, and the need for space situation awareness in medium Earth orbit where electric orbit raising takes place.

Publicly Available Geosynchronous (GEO) Space Object Catalog for Future Space Situational Awareness (SSA) Studies

Science.gov (United States)

Koblick, D. C.; Shankar, P.; Xu, S.

Previously, there have been many commercial proposals and extensive academic studies regarding ground and space based sensors to assist a space surveillance network in obtaining metric observations of satellites and debris near Geosynchronous Earth Orbit (GEO). Most use physics based models for geometric constraints, lighting, and tasker/scheduler operations of sensor architectures. Under similar physics modeling assumptions, the space object catalog is often different due to proprietary standards and datasets. Lack of catalog commonality between studies creates barriers and difficulty comparing performance benefits of sensor trades. To solve this problem, we have constructed a future GEO space catalog from publicly available datasets and literature. The annual number of new payloads and rocket bodies is drawn from a Poisson distribution while the growth of the current GEO catalog is bootstrapped from the historical payload, upper stage, and debris data. We adopt a spherically symmetric explosion model and couple it with the NASA standard breakup model to simulate explosions of payloads and rocket bodies as they are the primary drivers of the debris population growth. The cumulative number of fragments follow a power-law distribution. Result from 1,000 random catalog growth simulations indicates that the GEO space object population in the year 2050 will include over 3,600 objects, nearly half of which are debris greater than 10 cm spherical diameter. The number of rocket bodies and dead payloads is projected to nearly double over the next 33 years. For comparison, the current Air Force Space Command catalog snapshot contains fewer than 50 pieces of debris and coarse Radar Cross Section (RCS) estimates which include: small, medium, and large. The current catalog may be sufficient for conjunction studies, but not for analyzing future sensor system performance. The 2050 GEO projected catalog will be available online for commercial/academic research and development.

NASDA and the Space Industry in Japan

Science.gov (United States)

Takamatsu, Hideo

2002-01-01

With over 30 years of history in space activities, Japan is now recognized as one of space powers in the world. Compared to other countries though, the features of Japanese space development are unique in several aspects. At first, its efforts are directed solely toward peaceful purposes and strictly separated from military uses. Secondly, there are many space related governmental agencies and institutes which are under supervision of different ministries. Thirdly, although the government budget is moderate and sales revenue of space industries is not so large, many large companies in aerospace or electronics industries see the importance of this business and compete each other mainly in the domestic market. NASDA, founded in 1969, is the largest governmental space organization and has played an important role in realizing practical applications of space activities. It has rapidly caught up the technology gap behind leading countries and has achieved remarkable successes with its own launch vehicles and satellites. Space industries, under the guidance of NASDA, have learned much from the U.S. companies and improved their technology levels and enjoyed steady growth during the early stage of Japanese space development. But before they became competitive enough in the world space business, the trade conflict between Japan and the U.S. made the procurement of Japanese non-R&D satellites open to the foreign satellite companies. Furthermore, interruptions of space activities due to recent successive failures of launch vehicles as well as Japanese economic slump have made space industries face hard situations. Under these circumstances, M&A of launch vehicle companies as well as satellite makers took place for the first time in Japanese aero-space history. Also at the government level, reorganization of space agencies is now under process. It is expected as a natural consequence of the merge of the Ministry of Education and the Science an Technology Agency, three space

Cross-cultural issues in space operations: A survey study among ground personnel of the European Space Agency

Science.gov (United States)

Sandal, Gro Mjeldheim; Manzey, Dietrich

2009-12-01

Today's space operations involve co-working of people with different ethnical, professional and organisational backgrounds. The aim of this study was to examine the implications of cultural diversity for efficient collaboration within the European Space Agency (ESA), and between ESA employees and representatives from other agencies. ESA employees from European countries ( N=576) answered to the CULT Ground Survey. The results showed that differences in relation to leadership and decision making were the most important issues thought to interfere with efficient co-working within ESA, and between ESA employees and colleagues from other agencies. Employees who collaborated with more than three nationalities within ESA indicated most challenges in co-working due to differences in compliance, behavioural norms and competitiveness. Challenges in co-working differed between agencies, and these differences were consistent with value differences in the national populations. The results may have applied value for training of European employees working in international space program teams.

Evaluation of an international doctoral educational program in space life sciences: The Helmholtz Space Life Sciences Research School (SpaceLife) in Germany

Science.gov (United States)

Hellweg, C. E.; Spitta, L. F.; Kopp, K.; Schmitz, C.; Reitz, G.; Gerzer, R.

2016-01-01

Training young researchers in the field of space life sciences is essential to vitalize the future of spaceflight. In 2009, the DLR Institute of Aerospace Medicine established the Helmholtz Space Life Sciences Research School (SpaceLife) in cooperation with several universities, starting with 22 doctoral candidates. SpaceLife offered an intensive three-year training program for early-stage researchers from different fields (biology, biomedicine, biomedical engineering, physics, sports, nutrition, plant and space sciences). The candidates passed a multistep selection procedure with a written application, a self-presentation to a selection committee, and an interview with the prospective supervisors. The selected candidates from Germany as well as from abroad attended a curriculum taught in English. An overview of space life sciences was given in a workshop with introductory lectures on space radiation biology and dosimetry, space physiology, gravitational biology and astrobiology. The yearly Doctoral Students' Workshops were also interdisciplinary. During the first Doctoral Students' Workshop, every candidate presented his/her research topic including hypothesis and methods to be applied. The progress report was due after ∼1.5 years and a final report after ∼3 years. The candidates specialized in their subfield in advanced lectures, Journal Clubs, practical trainings, lab exchanges and elective courses. The students attended at least one transferable skills course per year, starting with a Research Skills Development course in the first year, a presentation and writing skills course in the second year, and a career and leadership course in the third year. The whole program encompassed 303 h and was complemented by active conference participation. In this paper, the six years' experience with this program is summarized in order to guide other institutions in establishment of structured Ph.D. programs in this field. The curriculum including elective courses is

National Space Agencies vs. Commercial Space: Towards Improved Space Safety

Science.gov (United States)

Pelton, J.

2013-09-01

Traditional space policies as developed at the national level includes many elements but they are most typically driven by economic and political objectives. Legislatively administered programs apportion limited public funds to achieve "gains" that can involve employment, stimulus to the economy, national defense or other advancements. Yet political advantage is seldom far from the picture.Within the context of traditional space policies, safety issues cannot truly be described as "afterthoughts", but they are usually, at best, a secondary or even tertiary consideration. "Space safety" is often simply assumed to be "in there" somewhere. The current key question is can "safety and risk minimization", within new commercial space programs actually be elevated in importance and effectively be "designed in" at the outset. This has long been the case with commercial aviation and there is at least reasonable hope that this could also be the case for the commercial space industry in coming years. The cooperative role that the insurance industry has now played for centuries in the shipping industry and for decades in aviation can perhaps now play a constructive role in risk minimization in the commercial space domain as well. This paper begins by examining two historical case studies in the context of traditional national space policy development to see how major space policy decisions involving "manned space programs" have given undue primacy to "political considerations" over "safety" and other factors. The specific case histories examined here include first the decision to undertake the Space Shuttle Program (i.e. 1970-1972) and the second is the International Space Station. In both cases the key and overarching decisions were driven by political, schedule and cost considerations, and safety seems absence as a prime consideration. In publicly funded space programs—whether in the United States, Europe, Russia, Japan, China, India or elsewhere—it seems realistic to

Curved twistor spaces and H-space

International Nuclear Information System (INIS)

Tod, K.P.

1980-01-01

The curved twistor space construction of Penrose for anti-self-dual solutions to the Einstein vacuum equations is described. Curved twistor spaces are defined and it is shown with the aid of an example how to obtain them by deforming the complex structure of regions of flat twistor space. The connection of this procedure with Newman's H-space construction via asymptotic twistor space is outlined. (Auth.)

Innovative Robot Archetypes for In-Space Construction and Maintenance

Science.gov (United States)

Rehnmark, Fredrik; Ambrose, Robert O.; Kennedy, Brett; Diftler, Myron; Mehling Joshua; Brigwater, Lyndon; Radford, Nicolaus; Goza, S. Michael; Culbert, Christopher

2005-01-01

The space environment presents unique challenges and opportunities in the assembly, inspection and maintenance of orbital and transit spaceflight systems. While conventional Extra-Vehicular Activity (EVA) technology, out of necessity, addresses each of the challenges, relatively few of the opportunities have been exploited due to crew safety and reliability considerations. Extra-Vehicular Robotics (EVR) is one of the least-explored design spaces but offers many exciting innovations transcending the crane-like Space Shuttle and International Space Station Remote Manipulator System (RMS) robots used for berthing, coarse positioning and stabilization. Microgravity environments can support new robotic archetypes with locomotion and manipulation capabilities analogous to undersea creatures. Such diversification could enable the next generation of space science platforms and vehicles that are too large and fragile to launch and deploy as self-contained payloads. Sinuous manipulators for minimally invasive inspection and repair in confined spaces, soft-stepping climbers with expansive leg reach envelopes and free-flying nanosatellite cameras can access EVA worksites generally not accessible to humans in spacesuits. These and other novel robotic archetypes are presented along with functionality concepts

Phase-space topography characterization of nonlinear ultrasound waveforms.

Science.gov (United States)

Dehghan-Niri, Ehsan; Al-Beer, Helem

2018-03-01

Fundamental understanding of ultrasound interaction with material discontinuities having closed interfaces has many engineering applications such as nondestructive evaluation of defects like kissing bonds and cracks in critical structural and mechanical components. In this paper, to analyze the acoustic field nonlinearities due to defects with closed interfaces, the use of a common technique in nonlinear physics, based on a phase-space topography construction of ultrasound waveform, is proposed. The central idea is to complement the "time" and "frequency" domain analyses with the "phase-space" domain analysis of nonlinear ultrasound waveforms. A nonlinear time series method known as pseudo phase-space topography construction is used to construct equivalent phase-space portrait of measured ultrasound waveforms. Several nonlinear models are considered to numerically simulate nonlinear ultrasound waveforms. The phase-space response of the simulated waveforms is shown to provide different topographic information, while the frequency domain shows similar spectral behavior. Thus, model classification can be substantially enhanced in the phase-space domain. Experimental results on high strength aluminum samples show that the phase-space transformation provides a unique detection and classification capabilities. The Poincaré map of the phase-space domain is also used to better understand the nonlinear behavior of ultrasound waveforms. It is shown that the analysis of ultrasound nonlinearities is more convenient and informative in the phase-space domain than in the frequency domain. Copyright © 2017 Elsevier B.V. All rights reserved.

NONLINEAR MULTIGRID SOLVER EXPLOITING AMGe COARSE SPACES WITH APPROXIMATION PROPERTIES

Energy Technology Data Exchange (ETDEWEB)

Christensen, Max La Cour [Technical Univ. of Denmark, Lyngby (Denmark); Villa, Umberto E. [Univ. of Texas, Austin, TX (United States); Engsig-Karup, Allan P. [Technical Univ. of Denmark, Lyngby (Denmark); Vassilevski, Panayot S. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

2016-01-22

The paper introduces a nonlinear multigrid solver for mixed nite element discretizations based on the Full Approximation Scheme (FAS) and element-based Algebraic Multigrid (AMGe). The main motivation to use FAS for unstruc- tured problems is the guaranteed approximation property of the AMGe coarse spaces that were developed recently at Lawrence Livermore National Laboratory. These give the ability to derive stable and accurate coarse nonlinear discretization problems. The previous attempts (including ones with the original AMGe method, [5, 11]), were less successful due to lack of such good approximation properties of the coarse spaces. With coarse spaces with approximation properties, our FAS approach on un- structured meshes should be as powerful/successful as FAS on geometrically re ned meshes. For comparison, Newton's method and Picard iterations with an inner state-of-the-art linear solver is compared to FAS on a nonlinear saddle point problem with applications to porous media ow. It is demonstrated that FAS is faster than Newton's method and Picard iterations for the experiments considered here. Due to the guaranteed approximation properties of our AMGe, the coarse spaces are very accurate, providing a solver with the potential for mesh-independent convergence on general unstructured meshes.

ASI's space automation and robotics programs: The second step

Science.gov (United States)

Dipippo, Simonetta

1994-01-01

The strategic decisions taken by ASI in the last few years in building up the overall A&R program, represent the technological drivers for other applications (i.e., internal automation of the Columbus Orbital Facility in the ESA Manned Space program, applications to mobile robots both in space and non-space environments, etc...). In this context, the main area of application now emerging is the scientific missions domain. Due to the broad range of applications of the developed technologies, both in the in-orbit servicing and maintenance of space structures and scientific missions, ASI foresaw the need to have a common technological development path, mainly focusing on: (1) control; (2) manipulation; (3) on-board computing; (4) sensors; and (5) teleoperation. Before entering into new applications in the scientific missions field, a brief overview of the status of the SPIDER related projects is given, underlining also the possible new applications for the LEO/GEO space structures.

Shouldering the blame for impingement: the rotator cuff continuum ...

African Journals Online (AJOL)

The aim of this article was to summarise recent research on shoulder impingement and rotator cuff pathology. A continuum model of rotator cuff pathology is described, and the challenges of accurate clinical diagnosis, imaging and best management discussed. Keywords: shoulder impingement syndrome, subacromial ...

Avoiding Shoulder Injury from Resistance Training.

Science.gov (United States)

Durall, Chris J.; Manske, Robert C.; Davies, George J.

2001-01-01

Identifies shoulder exercises commonly performed in fitness centers that may contribute to or exacerbate glenohumeral joint (shoulder) injury, describing alternative exercises that may be substituted and a offering rationale for the variations. The article focuses on anterior and posterior glenohumeral instability, subacromial impingement (primary…

Imaging of the shoulder after surgery

International Nuclear Information System (INIS)

McMenamin, Drew; Koulouris, George; Morrison, William B.

2008-01-01

Postoperative imaging of the shoulder is challenging. This article reviews the radiologic evaluation following surgery for subacromial impingment, rotator cuff lesions and glenohumeral instability, including the common surgical procedures, the expected postoperative findings and potential complications. A specific emphasis is made on magnetic resonance imaging

Imaging of the shoulder after surgery

Energy Technology Data Exchange (ETDEWEB)

McMenamin, Drew [Department of Radiology, University of Washington, Box 354755, 4245 Roosevelt Way NE, Seattle, WA 98105 (United States)], E-mail: drewmcm@u.washington.edu; Koulouris, George [Gold Coast Medical Imaging, 123 Nerang Street, Southport, QLD 4215 (Australia); Morrison, William B. [Thomas Jefferson University Hospital, 132 South 10th Street, Suite 1079a, Philadelphia, PA 19107 (United States)

2008-10-15

Postoperative imaging of the shoulder is challenging. This article reviews the radiologic evaluation following surgery for subacromial impingment, rotator cuff lesions and glenohumeral instability, including the common surgical procedures, the expected postoperative findings and potential complications. A specific emphasis is made on magnetic resonance imaging.

Space station evolution: Planning for the future

Science.gov (United States)

Diaz, Alphonso V.; Askins, Barbara S.

1987-06-01

The need for permanently manned presence in space has been recognized by the United States and its international partners for many years. The development of this capability was delayed due to the concurrent recognition that reusable earth-to-orbit transportation was also needed and should be developed first. While the decision to go ahead with a permanently manned Space Station was on hold, requirements for the use of the Station were accumulating as ground-based research and the data from unmanned spacecraft sparked the imagination of both scientists and entrepreneurs. Thus, by the time of the Space Station implementation decision in the early 1980's, a variety of disciplines, with a variety of requirements, needed to be accommodated on one Space Station. Additional future requirements could be forecast for advanced missions that were still in the early planning stages. The logical response was the development of a multi-purpose Space Station with the ability to evolve on-orbit to new capabilities as required by user needs and national or international decisions, i.e., to build an evolutionary Space Station. Planning for evolution is conducted in parallel with the design and development of the baseline Space Station. Evolution planning is a strategic management process to facilitate change and protect future decisions. The objective is not to forecast the future, but to understand the future options and the implications of these on today's decisions. The major actions required now are: (1) the incorporation of evolution provisions (hooks and scars) in the baseline Space Station; and (2) the initiation of an evolution advanced development program.

Space station evolution: Planning for the future

Science.gov (United States)

Diaz, Alphonso V.; Askins, Barbara S.

1987-01-01

The need for permanently manned presence in space has been recognized by the United States and its international partners for many years. The development of this capability was delayed due to the concurrent recognition that reusable earth-to-orbit transportation was also needed and should be developed first. While the decision to go ahead with a permanently manned Space Station was on hold, requirements for the use of the Station were accumulating as ground-based research and the data from unmanned spacecraft sparked the imagination of both scientists and entrepreneurs. Thus, by the time of the Space Station implementation decision in the early 1980's, a variety of disciplines, with a variety of requirements, needed to be accommodated on one Space Station. Additional future requirements could be forecast for advanced missions that were still in the early planning stages. The logical response was the development of a multi-purpose Space Station with the ability to evolve on-orbit to new capabilities as required by user needs and national or international decisions, i.e., to build an evolutionary Space Station. Planning for evolution is conducted in parallel with the design and development of the baseline Space Station. Evolution planning is a strategic management process to facilitate change and protect future decisions. The objective is not to forecast the future, but to understand the future options and the implications of these on today's decisions. The major actions required now are: (1) the incorporation of evolution provisions (hooks and scars) in the baseline Space Station; and (2) the initiation of an evolution advanced development program.

Environmental Studies at the Guiana Space Centre

Science.gov (United States)

Richard, Sandrine

2013-09-01

The Environmental Commitment of the French Space Agency at the Guiana Space Centre (CNES / CSG) specifies that the environmental protection is a major stake. Consequently, CNES participates in numerous space programs that contribute significantly to a better knowledge, management and protection of our environment at a global scale.The studies and researches that are done at CNES / CSG meet several objectives:* Assessment of safety and environmental effects and risk related to the effects overflowing due to a pollution caused by ground and flight activities* Improvement of the studies related to the knowledge of the environment (flora and fauna monitoring).* Risk assessment and management which may affect the safety of people , property, and protection of public health and environment * Verification of the compliance of the results of impact studies of launch vehicle in flight phase provided by the launch operator (Technical Regulation) with the French Safety Operational Acts.In this note, study and research programs are presented. They allow a better knowledge of the surrounding environment and of impacts caused by the industrial activities done in Guiana Space Center.

Developing Viable Financing Models for Space Tourism

Science.gov (United States)

Eilingsfeld, F.; Schaetzler, D.

2002-01-01

Increasing commercialization of space services and the impending release of government's control of space access promise to make space ventures more attractive. Still, many investors shy away from going into the space tourism market as long as they do not feel secure that their return expectations will be met. First and foremost, attracting investors from the capital markets requires qualifying financing models. Based on earlier research on the cost of capital for space tourism, this paper gives a brief run-through of commercial, technical and financial due diligence aspects. After that, a closer look is taken at different valuation techniques as well as alternative ways of streamlining financials. Experience from earlier ventures has shown that the high cost of capital represents a significant challenge. Thus, the sophistication and professionalism of business plans and financial models needs to be very high. Special emphasis is given to the optimization of the debt-to-equity ratio over time. The different roles of equity and debt over a venture's life cycle are explained. Based on the latter, guidelines for the design of an optimized loan structure are given. These are then applied to simulating the financial performance of a typical space tourism venture over time, including the calculation of Weighted Average Cost of Capital (WACC) and Net Present Value (NPV). Based on a concluding sensitivity analysis, the lessons learned are presented. If applied properly, these will help to make space tourism economically viable.

Biological and psychosocial effects of space travel: A case study

Science.gov (United States)

Hsia, Robert Edward Tien Ming

This dissertation interviewed a single astronaut to explore psychosocial issues relevant to long-duration space travel and how these issues relate to the astronaut's training. It examined the psychological impact of isolation, crew interaction, and the experience of microgravity with the goal of increasing understanding of how to foster crew survivability and positive small group interactions in space (Santy, 1994). It also focused on how to develop possible treatments for crews when they transition back to Earth from the extreme environment of space missions. The astronaut's responses agreed with the literature and the predictions for long-duration space missions except the participant reported no temporary or permanent cognitive or memory deficits due to microgravity exposure. The dissertation identified five frequently endorsed themes including communication, environmental stressors, personal strengths, un-researched problems, and other. The agreement found between the literature and astronaut's responses offer a strong foundation of questions and data that needs to be further studied before conducting research in space or long-duration space missions.

Landscape Management of Public Open Space in Bogor Heritage City

Science.gov (United States)

Pusparini, F. D.; Nurhayati; Arifin, H. S.

2017-10-01

Public open space landscape plays important role in Bogor Heritage City. Although these spaces can carry various kind of public activities and enhance environment quality, they are fragile to disturbance and changing due to city development. Therefore, as an effort to maintain public open space landscape in 8 zones within Heritage City of Bogor, management of public open space landscape is necessary. Syntesys of public open space landscape management had held by using Analytical Hierarchy Process (AHP). The AHP result showed public open space landscape in Palace and Botanical Garden of Bogor zone (20%) is in high priority to be maintained. The other zone are Situ Gede (16,9%), Plan Karsten (12,3%), European Settlement (12%), Suryakencana (11,2%), Batu Tulis (10,2%), Empang (9.2%) and West Development (8,2%). Ecological function (34,8%) becomes the most important function to be maintained (34.8%) then social culture (31.2%), economic (17%), and aesthetics (17%).

Relation of the runaway avalanche threshold to momentum space topology

Science.gov (United States)

McDevitt, Christopher J.; Guo, Zehua; Tang, Xian-Zhu

2018-02-01

The underlying physics responsible for the formation of an avalanche instability due to the generation of secondary electrons is studied. A careful examination of the momentum space topology of the runaway electron population is carried out with an eye toward identifying how qualitative changes in the momentum space of the runaway electrons is correlated with the avalanche threshold. It is found that the avalanche threshold is tied to the merger of an O and X point in the momentum space of the primary runaway electron population. Such a change of the momentum space topology is shown to be accurately described by a simple analytic model, thus providing a powerful means of determining the avalanche threshold for a range of model assumptions.

Space charge and magnet error simulations for the SNS accumulator ring

International Nuclear Information System (INIS)

Beebe-Wang, J.; Fedotov, A.V.; Wei, J.; Machida, S.

2000-01-01

The effects of space charge forces and magnet errors in the beam of the Spallation Neutron Source (SNS) accumulator ring are investigated. In this paper, the focus is on the emittance growth and halo/tail formation in the beam due to space charge with and without magnet errors. The beam properties of different particle distributions resulting from various injection painting schemes are investigated. Different working points in the design of SNS accumulator ring lattice are compared. The simulations in close-to-resonance condition in the presence of space charge and magnet errors are presented. (author)

Increase of nonlinear signal distortions due to linear mode coupling in space division multiplexed systems

DEFF Research Database (Denmark)

Kutluyarov, Ruslan V.; Bagmanov, Valeriy Kh; Antonov, Vyacheslav V.

2017-01-01

This paper is focused on the analysis of linear and nonlinear mode coupling in space division multiplexed (SDM) optical communications over step-index fiber in few-mode regime. Linear mode coupling is caused by the fiber imperfections, while the nonlinear coupling is caused by the Kerr......-nonlinearities. Therefore, we use the system of generalized coupled nonlinear Schrödinger equations (GCNLSE) to describe the signal propagation. We analytically show that the presence of linear mode coupling may cause increasing of the nonlinear signal distortions. For the detailed study we solve GCNLSE numerically...... for the standard step index fiber at the wavelength of 850 nm in the basis of spatial modes with helical phase front (vortex modes) and for a special kind of few-mode fiber with enlarged core, providing propagation of five spatial modes at 1550 nm. Simulation results confirm that the linear mode coupling may lead...

SpaceTech—Postgraduate space education

Science.gov (United States)

de Bruijn, Ferdi J.; Ashford, Edward W.; Larson, Wiley J.

2008-07-01

SpaceTech is a postgraduate program geared primarily for mid-career space professionals seeking to gain or improve their expertise in space systems engineering and in business engineering. SpaceTech provides a lifelong impact on its participants by broadening their capabilities, encouraging systematic "end-to-end" thinking and preparing them for any technical or business-related engineering challenges they may encounter. This flexible 1-year program offers high competency gain and increased business skills. It is held in attractive locations in a flexible, multi-cultural environment. SpaceTech is a highly effective master's program certified by the esteemed Technical University of Delft (TUD), Netherlands. SpaceTech provides expert instructors who place no barriers between themselves and participants. The program combines innovative and flexible new approaches with time-tested methods to give participants the skills required for future missions and new business, while allowing participants to meet their work commitments at the same time as they study for their master's degree. The SpaceTech program is conducted in separate sessions, generally each of 2-week duration, separated by periods of some 6-8 weeks, during which time participants may return to their normal jobs. It also includes introductory online course material that the participants can study at their leisure. The first session is held at the TUD, with subsequent sessions held at strategic space agency locations. By participating at two or more of these sessions, attendees can earn certificates of satisfactory completion from TU Delft. By participating in all of the sessions, as well as taking part in the companion Central Case Project (CCP), participants earn an accredited and highly respected master's degree in Space Systems Engineering from the TUD. Seven distinct SpaceTech modules are provided during these sessions: Space Mission Analysis and Design, Systems Engineering, Business Engineering

Structure of twistor and H-spaces

International Nuclear Information System (INIS)

Lugo, G.G.

1979-01-01

In chapter one, we review briefly the spinor and twistor formalisms in general relativity. Following some suggestions of A.H. Taub, we show that the local twistor structure of a general curved space-time is closely related to the conformal structure used by B.G. Schmidt to define conformal infinity. In particular, we prove that the normal Cartan connection of the conformal bundle coincides with the connection which gives the covariant derivative of local twistors. In chapter two, we use the results of E.T. Newman and J. Plebanski to construct some explicit self-dual metrics. These solutions are of interest because they are good candidates for what we would like to call asymptotically flat H-spaces. Furthermore, by a closer look at these metrics, we may gain more insight into the behavior of twistor spaces near the boundary. In chapter three, we study the geometric structure of twistor spaces associated with asymptotically flat space-times. We show that the space of asymptotic projective twistors, PT + , is an Einstein Kaehler manifold of constant holomorphic sectional curvature. We also give a brief description of the twistor space construction of the metrics in chapter two. In chapter four, we apply the Chern-Moser theory of the pseudoconformal geometry of real hypersurfaces in complex manifolds to study the structure of the boundary PN of PT + . Using some ideas due to S. Webster, we show that the Chern-Moser curvature invariants of PN coincide with the Kaehler curvature invariants of PT + . From the results of chapter three, we deduce that the pseudoconformal geodesics (chains) of the boundary are nicely behaved

Acromion types and role of corticosteroid with shoulder impingement syndrome

International Nuclear Information System (INIS)

Akram, M.; Gillani, S.F.U.S.; Awais, S.M.

2016-01-01

To determine the association between shoulder impingement and morphological characteristics of acromion and the role of sub-acromial injection of methylprednisolone in the short-term treatment for relieving pain and improve functional disability of these patients. Study Design: A descriptive study. Place and Duration of Study: Department of Orthopedic Surgery and Traumatology Unit-I (DOST-I), Mayo Hospital, Lahore, between November 2013 to June 2014. Methodology: All patients presented in OPD with shoulder pain were included as subjects and evaluated by clinical test and categorised using X-ray scapula Y-view. Patients with impingement syndrome were correlated with Bigliani types and offered intra-lesional injection into sub-acromial space with 2ml of xylocaine 2% and 40 mg of methylprednisolone using 22 gauge needle. The effectiveness was assessed in terms of relieving pain and good functional outcomes; and rotator cuff tear was clinically assessed among impingement positive patient. The pain was assessed using visual analogue score before and after the administration of the injection. Demographic variables for frequencies and their associations were analysed using SPSS version 20.0. Significance level was p<0.05. Among the 101 cases, there was no case of tear of rotator cuff tendon on clinical assessment. Majority of the patients (58.4%) were females with mean age of 31.38 +-1.13 years. Majority 57 (56.4%) of the patients had acromion type II (curved), which was the most common cause of shoulder impingement. Most had moderate pain. Thirty-four patients required intralesional steroid, which relieved the pain in 31 of them. Conclusion: Shoulder impingement syndrome without tear of rotator cuff tendon was found in younger age group between 40 to 45 years, which was relieved by intralesional corticosteroid administration. These patients had type II (curved) acromion, according to Bigliani classification. (author)

Role of the Space Station in Private Development of Space

Science.gov (United States)

Uhran, M. L.

2002-01-01

by the ISS partnership today will effect the later outcome. This paper reviews the range of activities underway in the U.S., as well those being pursued on a multilateral basis across the partnership. It will report on the status of NASA planning for establishment of a non-governmental organization (NGO) to manage the U.S. share of ISS user resources and accommodations. This initiative is unprecedented for a human-rated space craft of ISS magnitude and represents an extraordinarily complex undertaking due to the multi-mission, multi-partner nature of the program. Nonetheless, major advances are scheduled for 2002, as a new NASA Administrator takes the helm and declares the study phase is over. On the global front, the ISS Partners have formed a Multilateral Commercialization Group (MCG) charged to develop Recommended Guidelines for ISS Commercial Activities. Areas such as advertising, merchandising, entertainment, and sponsorship are actively under consideration with plans to advance to the long-awaited decision phase. In conjunction with this project, the challenging issue of how to create, protect, and potentially market the ISS brand to the benefit of the Partners, as well as the scientific, technological and commercial users of the station, is approaching resolution. In the area of space product development, the NASA Commercial Space Centers are entering the era of the space station with new operating principles and practices that promise a focused and sustainable research and development program. This portfolio of seventeen cooperative agreements spans applications in biotechnology, agriculture, remote sensing, and advanced materials. The rate-limiting step has long been access to space and we now stand ready to seize the opportunities afforded by a continuously operating, full-service laboratory in orbit. Each of these initiatives will have a marked effect on evolution of the space station program from a commercial development perspective and each offers the

Second order elastic metrics on the shape space of curves

DEFF Research Database (Denmark)

Bauer, Martin; Bruveris, Martins; Harms, Philipp

2015-01-01

Second order Sobolev metrics on the space of regular unparametrized planar curves have several desirable completeness properties not present in lower order metrics, but numerics are still largely missing. In this paper, we present algorithms to numerically solve the initial and boundary value......, due to its generality, it could be applied to more general spaces of mapping. We demonstrate the effectiveness of our approach by analyzing a collection of shapes representing physical objects....

Independence and totalness of subspaces in phase space methods

Science.gov (United States)

Vourdas, A.

2018-04-01

The concepts of independence and totalness of subspaces are introduced in the context of quasi-probability distributions in phase space, for quantum systems with finite-dimensional Hilbert space. It is shown that due to the non-distributivity of the lattice of subspaces, there are various levels of independence, from pairwise independence up to (full) independence. Pairwise totalness, totalness and other intermediate concepts are also introduced, which roughly express that the subspaces overlap strongly among themselves, and they cover the full Hilbert space. A duality between independence and totalness, that involves orthocomplementation (logical NOT operation), is discussed. Another approach to independence is also studied, using Rota's formalism on independent partitions of the Hilbert space. This is used to define informational independence, which is proved to be equivalent to independence. As an application, the pentagram (used in discussions on contextuality) is analysed using these concepts.

Space situational awareness satellites and ground based radiation counting and imaging detector technology

International Nuclear Information System (INIS)

Jansen, Frank; Behrens, Joerg; Pospisil, Stanislav; Kudela, Karel

2011-01-01

We review the current status from the scientific and technological point of view of solar energetic particles, solar and galactic cosmic ray measurements as well as high energy UV-, X- and gamma-ray imaging of the Sun. These particles and electromagnetic data are an important tool for space situational awareness (SSA) aspects like space weather storm predictions to avoid failures in space, air and ground based technological systems. Real time data acquisition, position and energy sensitive imaging are demanded by the international space weather forecast services. We present how newly developed, highly miniaturized radiation detectors can find application in space in view of future SSA related satellites as a novel space application due to their counting and imaging capabilities.

Space situational awareness satellites and ground based radiation counting and imaging detector technology

Energy Technology Data Exchange (ETDEWEB)

Jansen, Frank, E-mail: frank.jansen@dlr.de [DLR Institute of Space Systems, Robert-Hooke-Str. 7, 28359 Bremen (Germany); Behrens, Joerg [DLR Institute of Space Systems, Robert-Hooke-Str. 7, 28359 Bremen (Germany); Pospisil, Stanislav [Czech Technical University, IEAP, 12800 Prague 2, Horska 3a/22 (Czech Republic); Kudela, Karel [Slovak Academy of Sciences, IEP, 04001 Kosice, Watsonova 47 (Slovakia)

2011-05-15

We review the current status from the scientific and technological point of view of solar energetic particles, solar and galactic cosmic ray measurements as well as high energy UV-, X- and gamma-ray imaging of the Sun. These particles and electromagnetic data are an important tool for space situational awareness (SSA) aspects like space weather storm predictions to avoid failures in space, air and ground based technological systems. Real time data acquisition, position and energy sensitive imaging are demanded by the international space weather forecast services. We present how newly developed, highly miniaturized radiation detectors can find application in space in view of future SSA related satellites as a novel space application due to their counting and imaging capabilities.

Report of space experiment project, 'Rad Gene', performed in the International Space Station Kibo

International Nuclear Information System (INIS)

Ohnishi, Takeo; Takahashi, Akihisa; Nagamatsu, Aiko

2010-01-01

cells alone. Inhibition of cell proliferation, and inductions of apoptosis, chromosome aberration and mutation with 2-Gy acute exposure on the ground are found to be suppressed in normal p53 cells frozen during the space flight and not in mutated cells, clearly showing the response due to the space radiation. All of these results are more satisfactory than expected and are useful for risk assessment of space flight in future. (T.T.)

Myelopathy due to Spinal Extramedullary Hematopoiesis in a Patient with Polycythemia Vera

Directory of Open Access Journals (Sweden)

Shuhei Ito

2017-01-01

Full Text Available Extramedullary hematopoiesis (EMH occasionally occurs in patients exhibiting hematological disorders with decreased hematopoietic efficacy. EMH is rarely observed in the spinal epidural space and patients are usually asymptomatic. In particular, in the patients with polycythemia vera, spinal cord compression due to EMH is extremely rare. We report a case of polycythemia vera, in which operative therapy proved to be an effective treatment for myelopathy caused by spinal EMH.

Myelopathy due to Spinal Extramedullary Hematopoiesis in a Patient with Polycythemia Vera.

Science.gov (United States)

Ito, Shuhei; Fujita, Nobuyuki; Hosogane, Naobumi; Nagoshi, Narihito; Yagi, Mitsuru; Iwanami, Akio; Watanabe, Kota; Tsuji, Takashi; Nakamura, Masaya; Matsumoto, Morio; Ishii, Ken

2017-01-01

Extramedullary hematopoiesis (EMH) occasionally occurs in patients exhibiting hematological disorders with decreased hematopoietic efficacy. EMH is rarely observed in the spinal epidural space and patients are usually asymptomatic. In particular, in the patients with polycythemia vera, spinal cord compression due to EMH is extremely rare. We report a case of polycythemia vera, in which operative therapy proved to be an effective treatment for myelopathy caused by spinal EMH.

Myelopathy due to Spinal Extramedullary Hematopoiesis in a Patient with Polycythemia Vera

OpenAIRE

Ito, Shuhei; Fujita, Nobuyuki; Hosogane, Naobumi; Nagoshi, Narihito; Yagi, Mitsuru; Iwanami, Akio; Watanabe, Kota; Tsuji, Takashi; Nakamura, Masaya; Matsumoto, Morio; Ishii, Ken

2017-01-01

Extramedullary hematopoiesis (EMH) occasionally occurs in patients exhibiting hematological disorders with decreased hematopoietic efficacy. EMH is rarely observed in the spinal epidural space and patients are usually asymptomatic. In particular, in the patients with polycythemia vera, spinal cord compression due to EMH is extremely rare. We report a case of polycythemia vera, in which operative therapy proved to be an effective treatment for myelopathy caused by spinal EMH.

Preparation of All-Ceramic, High Performance Li-ion Batteries for Deep Space Power Systems, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — Lithium (Li) ion batteries are among the most promising power sources for many civilian, military and space applications due to their high power and high energy...

Evidence Report: Risk of Crew Adverse Health Event Due to Altered Immune Response

Science.gov (United States)

Crucian, Brian; Sams, Clarence F.

2013-01-01

The Risk of Crew Adverse Health Event Due to Altered Immune Response is identified by the National Aeronautics and Space Administration (NASA) Human Research Program (HRP) as a recognized risk to human health and performance in space. The HRP Program Requirements Document (PRD) defines these risks. This Evidence Report provides a summary of the evidence that has been used to identify and characterize this risk. It is known that human immune function is altered in- and post-flight, but it is unclear at present if such alterations lead to increased susceptibility to disease. Reactivation of latent viruses has been documented in crewmembers, although this reactivation has not been directly correlated with immune changes or with observed diseases. As described in this report, further research is required to better characterize the relationships between altered immune response and susceptibility to disease during and after spaceflight. This is particularly important for future deep-space exploration missions.

Reproduction in the space environment: Part II. Concerns for human reproduction

Science.gov (United States)

Jennings, R. T.; Santy, P. A.

1990-01-01

Long-duration space flight and eventual colonization of our solar system will require successful control of reproductive function and a thorough understanding of factors unique to space flight and their impact on gynecologic and obstetric parameters. Part II of this paper examines the specific environmental factors associated with space flight and the implications for human reproduction. Space environmental hazards discussed include radiation, alteration in atmospheric pressure and breathing gas partial pressures, prolonged toxicological exposure, and microgravity. The effects of countermeasures necessary to reduce cardiovascular deconditioning, calcium loss, muscle wasting, and neurovestibular problems are also considered. In addition, the impact of microgravity on male fertility and gamete quality is explored. Due to current constraints, human pregnancy is now contraindicated for space flight. However, a program to explore effective countermeasures to current constraints and develop the required health care delivery capability for extended-duration space flight is suggested. A program of Earth- and space-based research to provide further answers to reproductive questions is suggested.

Manipulation and Investigation of Uniformly-Spaced Nanowire Array on a Substrate via Dielectrophoresis and Electrostatic Interaction

Directory of Open Access Journals (Sweden)

U Hyeok Choi

2018-06-01

Full Text Available Directed-assembly of nanowires on the dielectrics-covered parallel electrode structure is capable of producing uniformly-spaced nanowire array at the electrode gap due to dielectrophoretic nanowire attraction and electrostatic nanowire repulsion. Beyond uniformly-spaced nanowire array formation, the control of spacing in the array is beneficial in that it should be the experimental basis of the precise positioning of functional nanowires on a circuit. Here, we investigate the material parameters and bias conditions to modulate the nanowire spacing in the ordered array, where the nanowire array formation is readily attained due to the electrostatic nanowire interaction. A theoretical model for the force calculation and the simulation of the induced charge in the assembled nanowire verifies that the longer nanowires on thicker dielectric layer tend to be assembled with a larger pitch due to the stronger nanowire-nanowire electrostatic repulsion, which is consistent with the experimental results. It was claimed that the stronger dielectrophoretic force is likely to attract more nanowires that are suspended in solution at the electrode gap, causing them to be less-spaced. Thus, we propose a generic mechanism, competition of dielectrophoretic and electrostatic force, to determine the nanowire pitch in an ordered array. Furthermore, this spacing-controlled nanowire array offers a way to fabricate the high-density nanodevice array without nanowire registration.

New protocol for dissociating visuospatial working memory ability in reaching space and in navigational space.

Science.gov (United States)

Lupo, Michela; Ferlazzo, Fabio; Aloise, Fabio; Di Nocera, Francesco; Tedesco, Anna Maria; Cardillo, Chiara; Leggio, Maria

2018-04-27

Several studies have demonstrated that the processing of visuospatial memory for locations in reaching space and in navigational space is supported by independent systems, and that the coding of visuospatial information depends on the modality of the presentation (i.e., sequential or simultaneous). However, these lines of evidence and the most common neuropsychological tests used by clinicians to investigate visuospatial memory have several limitations (e.g., they are unable to analyze all the subcomponents of this function and are not directly comparable). Therefore, we developed a new battery of tests that is able to investigate these subcomponents. We recruited 71 healthy subjects who underwent sequential and simultaneous navigational tests by using an innovative sensorized platform, as well as comparable paper tests to evaluate the same components in reaching space (Exp. 1). Consistent with the literature, the principal-component method of analysis used in this study demonstrated the presence of distinct memory for sequences in different portions of space, but no distinction was found for simultaneous presentation, suggesting that different modalities of eye gaze exploration are used when subjects have to perform different types of tasks. For this purpose, an infrared Tobii Eye-Tracking X50 system was used in both spatial conditions (Exp. 2), showing that a clear effect of the presentation modality was due to the specific strategy used by subjects to explore the stimuli in space. Given these findings, the neuropsychological battery established in the present study allows us to show basic differences in the normal coding of stimuli, which can explain the specific visuospatial deficits found in various neurological conditions.

Space Shuttle Program (SSP) Dual Docked Operations (DDO)

Science.gov (United States)

Sills, Joel W., Jr.; Bruno, Erica E.

2016-01-01

This document describes the concept definition, studies, and analysis results generated by the Space Shuttle Program (SSP), International Space Station (ISS) Program (ISSP), and Mission Operations Directorate for implementing Dual Docked Operations (DDO) during mated Orbiter/ISS missions. This work was performed over a number of years. Due to the ever increasing visiting vehicle traffic to and from the ISS, it became apparent to both the ISSP and the SSP that there would arise occasions where conflicts between a visiting vehicle docking and/or undocking could overlap with a planned Space Shuttle launch and/or during docked operations. This potential conflict provided the genesis for evaluating risk mitigations to gain maximum flexibility for managing potential visiting vehicle traffic to and from the ISS and to maximize launch and landing opportunities for all visiting vehicles.

CPRIT/Johnson Space Center, September, 2011 (Cancer Prevention and Research Institute of Texas)

Science.gov (United States)

Davis, Jeffrey; Lane, Helen; Baker, Tracey; Cucinotta, Francis; Wu, Honglu

2011-01-01

JSC researchers study carcinogenesis, cancer prevention and treatment along with epidemiological (primarily retrospective and longitudinal) studies, modeling, and interactions with the environment such as radiation, nutritional, and endocrine changes related to space flight along with behaviors such as smoking. Cancer research is a major focus for human space flight due to the exposure to space radiation which consists of particles of varying charges and energies, and secondary neutrons. The JSC laboratories collaborate with investigators from the U.S. as well as our European and Japanese partners. We use accelerator facilities at the Brookhaven National Laboratory, Loma Linda University and Los Alamos National Laboratory that generate high energy charged particles and neutrons to simulate cosmic radiation and solar particle events. The research using cultured cells and animals concentrates on damage and repair from the level of DNA to organ tissues, due to exposure to simulated space radiation exposure, that contribute to the induction of leukemia and solid tumors in most major tissues such as lung, colon, liver and breast. The goal of the research is to develop a mathematical model that can predict cancer morbidity and mortality risks with sufficient accuracy for a given space mission.

Deep Space Habitat Configurations Based on International Space Station Systems

Science.gov (United States)

Smitherman, David; Russell, Tiffany; Baysinger, Mike; Capizzo, Pete; Fabisinski, Leo; Griffin, Brand; Hornsby, Linda; Maples, Dauphne; Miernik, Janie

2012-01-01

A Deep Space Habitat (DSH) is the crew habitation module designed for long duration missions. Although humans have lived in space for many years, there has never been a habitat beyond low-Earth-orbit. As part of the Advanced Exploration Systems (AES) Habitation Project, a study was conducted to develop weightless habitat configurations using systems based on International Space Station (ISS) designs. Two mission sizes are described for a 4-crew 60-day mission, and a 4-crew 500-day mission using standard Node, Lab, and Multi-Purpose Logistics Module (MPLM) sized elements, and ISS derived habitation systems. These durations were selected to explore the lower and upper bound for the exploration missions under consideration including a range of excursions within the Earth-Moon vicinity, near earth asteroids, and Mars orbit. Current methods for sizing the mass and volume for habitats are based on mathematical models that assume the construction of a new single volume habitat. In contrast to that approach, this study explored the use of ISS designs based on existing hardware where available and construction of new hardware based on ISS designs where appropriate. Findings included a very robust design that could be reused if the DSH were assembled and based at the ISS and a transportation system were provided for its return after each mission. Mass estimates were found to be higher than mathematical models due primarily to the use of multiple ISS modules instead of one new large module, but the maturity of the designs using flight qualified systems have potential for improved cost, schedule, and risk benefits.

Hierarchical phase space structure of dark matter haloes: Tidal debris, caustics, and dark matter annihilation

International Nuclear Information System (INIS)

Afshordi, Niayesh; Mohayaee, Roya; Bertschinger, Edmund

2009-01-01

Most of the mass content of dark matter haloes is expected to be in the form of tidal debris. The density of debris is not constant, but rather can grow due to formation of caustics at the apocenters and pericenters of the orbit, or decay as a result of phase mixing. In the phase space, the debris assemble in a hierarchy that is truncated by the primordial temperature of dark matter. Understanding this phase structure can be of significant importance for the interpretation of many astrophysical observations and, in particular, dark matter detection experiments. With this purpose in mind, we develop a general theoretical framework to describe the hierarchical structure of the phase space of cold dark matter haloes. We do not make any assumption of spherical symmetry and/or smooth and continuous accretion. Instead, working with correlation functions in the action-angle space, we can fully account for the hierarchical structure (predicting a two-point correlation function ∝ΔJ -1.6 in the action space), as well as the primordial discreteness of the phase space. As an application, we estimate the boost to the dark matter annihilation signal due to the structure of the phase space within virial radius: the boost due to the hierarchical tidal debris is of order unity, whereas the primordial discreteness of the phase structure can boost the total annihilation signal by up to an order of magnitude. The latter is dominated by the regions beyond 20% of the virial radius, and is largest for the recently formed haloes with the least degree of phase mixing. Nevertheless, as we argue in a companion paper, the boost due to small gravitationally-bound substructure can dominate this effect at low redshifts.

Hierarchical phase space structure of dark matter haloes: Tidal debris, caustics, and dark matter annihilation

Science.gov (United States)

Afshordi, Niayesh; Mohayaee, Roya; Bertschinger, Edmund

2009-04-01

Most of the mass content of dark matter haloes is expected to be in the form of tidal debris. The density of debris is not constant, but rather can grow due to formation of caustics at the apocenters and pericenters of the orbit, or decay as a result of phase mixing. In the phase space, the debris assemble in a hierarchy that is truncated by the primordial temperature of dark matter. Understanding this phase structure can be of significant importance for the interpretation of many astrophysical observations and, in particular, dark matter detection experiments. With this purpose in mind, we develop a general theoretical framework to describe the hierarchical structure of the phase space of cold dark matter haloes. We do not make any assumption of spherical symmetry and/or smooth and continuous accretion. Instead, working with correlation functions in the action-angle space, we can fully account for the hierarchical structure (predicting a two-point correlation function ∝ΔJ-1.6 in the action space), as well as the primordial discreteness of the phase space. As an application, we estimate the boost to the dark matter annihilation signal due to the structure of the phase space within virial radius: the boost due to the hierarchical tidal debris is of order unity, whereas the primordial discreteness of the phase structure can boost the total annihilation signal by up to an order of magnitude. The latter is dominated by the regions beyond 20% of the virial radius, and is largest for the recently formed haloes with the least degree of phase mixing. Nevertheless, as we argue in a companion paper, the boost due to small gravitationally-bound substructure can dominate this effect at low redshifts.

Design optimization of space launch vehicles using a genetic algorithm

Science.gov (United States)

Bayley, Douglas James

The United States Air Force (USAF) continues to have a need for assured access to space. In addition to flexible and responsive spacelift, a reduction in the cost per launch of space launch vehicles is also desirable. For this purpose, an investigation of the design optimization of space launch vehicles has been conducted. Using a suite of custom codes, the performance aspects of an entire space launch vehicle were analyzed. A genetic algorithm (GA) was employed to optimize the design of the space launch vehicle. A cost model was incorporated into the optimization process with the goal of minimizing the overall vehicle cost. The other goals of the design optimization included obtaining the proper altitude and velocity to achieve a low-Earth orbit. Specific mission parameters that are particular to USAF space endeavors were specified at the start of the design optimization process. Solid propellant motors, liquid fueled rockets, and air-launched systems in various configurations provided the propulsion systems for two, three and four-stage launch vehicles. Mass properties models, an aerodynamics model, and a six-degree-of-freedom (6DOF) flight dynamics simulator were all used to model the system. The results show the feasibility of this method in designing launch vehicles that meet mission requirements. Comparisons to existing real world systems provide the validation for the physical system models. However, the ability to obtain a truly minimized cost was elusive. The cost model uses an industry standard approach, however, validation of this portion of the model was challenging due to the proprietary nature of cost figures and due to the dependence of many existing systems on surplus hardware.

Comparison of SPACE to MARS-KS under SUBO experimental conditions

International Nuclear Information System (INIS)

Kim, Min-Gil; Lee, Wonwoong; Lee, Jeong Ik; Bang, Young Seok

2015-01-01

To evaluate safety of a Korean Nuclear Power Plant (NPP) MARS-KS code is being used by the Korean regulator. The governing equations of MARS-KS are based on two-phase and two-fluid model. Recently, SPACE (Safety and Performance Analysis CodE for nuclear power plants) was developed by a consortium led by Korea Hydro and Nuclear Power Co., Ltd. (KHNP), which the code is aimed for evaluating the safety of the designed nuclear power plant. The governing equations of SPACE are based on two-phase (liquid and gas phase) three-fluid (continuous liquid, gas and droplet) model. However, MARS-KS and SPACE have different governing equations, as well as model and correlations implemented in two codes. Due to this reason, the authors are studying the difference in the analysis result of SET (Separate Effect Test) of each code.. To compare the SPACE and MARS-KS performances, the authors chose SUBO experiment as the first reference case. Input deck of each code was prepared. The results from the two codes were compared to the experimental data, but due to the lack of information on the uncertainties it is too early to conclude the code performance. However, from the obtained analysis results, some differences between MARS-KS and SPACE are observed. Especially, flow regimes at heated region are considerably different. More detailed analysis of the flow regime and its effect in MARS-KS and SPACE analysis results will be followed in the near future. The heat transfer coefficient and friction factor at the interface and at the wall will be compared with similar method used in this study

Velocity-space particle loss in field-reversed theta pinches

International Nuclear Information System (INIS)

Hsiao, M.Y.

1983-01-01

A field-reversed theta pinch (FRTP) is a compact device for magnetic fusion. It has attracted much attention in recent years since encouraging experimental results have been obtained. However, the definite causes for the observed particle loss rate and plasma rotation are not well known. In this work, we study the velocity-space particle loss (VSPL), i.e., particle loss due to the existence of a loss region in velocity space, in FRTP's in order to have a better understanding about the characteristics of this device

Semantic Representations in 3D Perceptual Space

Directory of Open Access Journals (Sweden)

Suncica Zdravkovic

2011-05-01

Full Text Available Barsalou's (1999 perceptual theory of knowledge echoes the pre-20th century tradition of conceptualizing all knowledge as inherently perceptual. Hence conceptual space has an infinite number of dimensions and heavily relies on perceptual experience. Osgood's (1952 semantic differential technique was developed as a bridge between perception and semantics. We updated Osgood's methodology in order to investigate current issues in visual cognition by: (1 using a 2D rather than a 1D space to place the concepts, (2 having dimensions that were perceptual while the targets were conceptual, (3 coupling visual experience with another two perceptual domains (audition and touch, (4 analyzing the data using MDS (not factor analysis. In three experiments, subjects (N = 57 judged five concrete and five abstract words on seven bipolar scales in three perceptual modalities. The 2D space led to different patterns of response compared to the classic 1D space. MDS revealed that perceptual modalities are not equally informative for mapping word-meaning distances (Mantel min = −.23; Mantel max = .88. There was no reliable differences due to test administration modality (paper vs. computer, nor scale orientation. The present findings are consistent with multidimensionality of conceptual space, a perceptual basis for knowledge, and dynamic characteristics of concepts discussed in contemporary theories.

Emittance growth due to static and radiative space charge forces in an electron bunch compressor

CERN Document Server

Talman, Richard; Stulle, Frank

2009-01-01

Evolution of short intense electron bunches passing through bunch-compressing beam lines is studied using the UAL (Unified Accelerator Libraries) string space charge formulation [R. Talman, Phys. Rev. ST Accel. Beams 7, 100701 (2004); N. Malitsky and R. Talman, in Proceedings of the 9th European Particle Accelerator Conference, Lucerne, 2004 (EPS-AG, Lucerne, 2004); R. Talman, Accelerator X-Ray Sources (Wiley-VCH, Weinheim, 2006), Chap. 13]. Three major configurations are studied, with the first most important and studied in greatest detail (because actual experimental results are available and the same results have been simulated with other codes): (i) Experimental bunch compression results were obtained at CTF-II, the CERN test facility for the “Compact Linear Collider” using electrons of about 40 MeV. Previous simulations of these results have been performed (using trafic4* [A. Kabel et al., Nucl. Instrum. Methods Phys. Res., Sect. A 455, 185 (2000)] and elegant [M. Borland, Argonne National Laboratory...

The value of clinical tests in acute full-thickness tears of the supraspinatus tendon

DEFF Research Database (Denmark)

Bak, Klaus; Sørensen, Anne Kathrine Belling; Jørgensen, Uffe Viegh

2010-01-01

Early repair of rotator cuff tears leads to superior results. To detect symptomatic full-thickness tears of the supraspinatus tendon at an early stage, we conducted a prospective study to evaluate the value of clinical examination with and without subacromial lidocaine within the first weeks after...

Effects of experimental muscle pain on shoulder-abduction force steadiness and muscle activity in healthy subjects

DEFF Research Database (Denmark)

Bandholm, Thomas Quaade; Rasmussen, Lars; Aagaard, Per

2007-01-01

We previously demonstrated that the steadiness of shoulder abduction is reduced in patients with subacromial impingement syndrome (SIS), which might be related to shoulder pain associated with the SIS. The aim of the present study was to examine the acute effects of experimental shoulder muscle p...

Underground spaces/cybernetic spaces

Directory of Open Access Journals (Sweden)

Tomaž Novljan

2000-01-01

Full Text Available A modern city space is a space where in the vertical and horizontal direction dynamic, non-linear processes exist, similar as in nature. Alongside the “common” city surface, cities have underground spaces as well that are increasingly affecting the functioning of the former. It is the space of material and cybernetic communication/transport. The psychophysical specifics of using underground places have an important role in their conceptualisation. The most evident facts being their limited volume and often limited connections to the surface and increased level of potential dangers of all kinds. An efficient mode for alleviating the effects of these specific features are artistic interventions, such as: shape, colour, lighting, all applications of the basic principles of fractal theory.

Enhanced Predictions of Time to Critical Dielectric Breakdown of Materials Under Prolonged Exposure to Space Plasma Environments

Data.gov (United States)

National Aeronautics and Space Administration — The leading cause of spacecraft failures and malfunctions due to interactions with the space plasma environment is electrostatic discharge (ESD). The enhanced time...

Calcific tendinitis of the rotator cuff: management options.

Science.gov (United States)

Suzuki, Kentaro; Potts, Aaron; Anakwenze, Oke; Singh, Anshu

2014-11-01

Calcific tendinitis of the rotator cuff tendons is a common cause of shoulder pain in adults and typically presents as activity-related shoulder pain. It is thought to be an active, cell-mediated process, although the exact pathophysiology remains unclear. Nonsurgical management continues to be the mainstay of treatment; most patients improve with modalities such as oral anti-inflammatory medication, physical therapy, and corticosteroid injections. Several options are available for patients who fail nonsurgical treatment, including extracorporeal shock wave therapy, ultrasound-guided needle lavage, and surgical débridement. These modalities alleviate pain by eliminating the calcific deposit, and several recent studies have demonstrated success with the use of these treatment options. Surgical management options include arthroscopic procedures to remove calcific deposits and subacromial decompression; however, the role of subacromial decompression and repair of rotator cuff defects created by removing these deposits remains controversial. Copyright 2014 by the American Academy of Orthopaedic Surgeons.

Life Support for Deep Space and Mars

Science.gov (United States)

Jones, Harry W.; Hodgson, Edward W.; Kliss, Mark H.

2014-01-01

How should life support for deep space be developed? The International Space Station (ISS) life support system is the operational result of many decades of research and development. Long duration deep space missions such as Mars have been expected to use matured and upgraded versions of ISS life support. Deep space life support must use the knowledge base incorporated in ISS but it must also meet much more difficult requirements. The primary new requirement is that life support in deep space must be considerably more reliable than on ISS or anywhere in the Earth-Moon system, where emergency resupply and a quick return are possible. Due to the great distance from Earth and the long duration of deep space missions, if life support systems fail, the traditional approaches for emergency supply of oxygen and water, emergency supply of parts, and crew return to Earth or escape to a safe haven are likely infeasible. The Orbital Replacement Unit (ORU) maintenance approach used by ISS is unsuitable for deep space with ORU's as large and complex as those originally provided in ISS designs because it minimizes opportunities for commonality of spares, requires replacement of many functional parts with each failure, and results in substantial launch mass and volume penalties. It has become impractical even for ISS after the shuttle era, resulting in the need for ad hoc repair activity at lower assembly levels with consequent crew time penalties and extended repair timelines. Less complex, more robust technical approaches may be needed to meet the difficult deep space requirements for reliability, maintainability, and reparability. Developing an entirely new life support system would neglect what has been achieved. The suggested approach is use the ISS life support technologies as a platform to build on and to continue to improve ISS subsystems while also developing new subsystems where needed to meet deep space requirements.

Assessment of zero gravity effects on space worker health and safety

Science.gov (United States)

1980-01-01

One objective of the study is to assess the effects of all currently known deviations from normal of medical, physiological, and biochemical parameters which appear to be due to zero gravity (zero-g) environment and to acceleration and deceleration to be experienced, as outlined in the references Solar Power Satellites (SPS) design, by space worker. Study results include identification of possible health or safety effects on space workers either immediate or delayed due to the zero gravity environment and acceleration and deceleration; estimation of the probability that an individual will be adversely affected; description of the possible consequence to work efficiency in persons adversely affected; and description of the possible/probable consequences to immediate and future health of individuals exposed to this environment. A research plan, which addresses the uncertainties in current knowledge regarding the health and safety hazards to exposed SPS space workers, is presented. Although most adverse affects experienced during space flight soon disappeared upon return to the Earth's environment, there remains a definite concern for the long-term effects to SPS space workers who might spend as much as half their time in space during a possible five year career period. The proposed 90 day up/90 day down cycle, coupled with the fact that most of the effects of weightlessness may persist throughout the flight along with the realization that recovery may occupy much of the terrestrial stay, may keep the SPS workers in a deviant physical condition or state of flux for 60 to 100% of their five year career.

Assessment of zero gravity effects on space worker health and safety

Energy Technology Data Exchange (ETDEWEB)

1980-11-01

One objective of the study is to assess the effects of all currently known deviations from normal of medical, physiological, and biochemical parameters which appear to be due to zero gravity (zero-g) environment and to acceleration and deceleration to be experienced, as outlined in the reference Solar Power Satellite (SPS) design, by space worker. Study results include identification of possible health or safety effects on space workers - either immediate or delayed - due to the zero gravity environment and acceleration and deceleration; estimation of the probability that an individual will be adversely affected; description of the possible consequence to work efficiently in persons adversely affected; and description of the possible/probable consequences to immediate and future health of individuals exposed to this environment. A research plan, which addresses the uncertainties in current knowledge regarding the health and safety hazards to exposed SPS space workers, is presented. Although most adverse affects experienced during space flight soon disappeared upon return to the Earth's environment, there remains a definite concern for the long-term effects to SPS space workers who might spend as much as half their time in space during a possible five-year career period. The proposed 90-day up/90 day down cycle, coupled with the fact that most of the effects of weightlessness may persist throughout the flight along with the realization that recovery may occupy much of the terrestrial stay, may keep the SPS workers in a deviant physical condition or state of flux for 60 to 100% of their five-year career. (JGB)

Exploring Lovelock theory moduli space for Schrödinger solutions

Directory of Open Access Journals (Sweden)

Dileep P. Jatkar

2016-09-01

Full Text Available We look for Schrödinger solutions in Lovelock gravity in D>4. We span the entire parameter space and determine parametric relations under which the Schrödinger solution exists. We find that in arbitrary dimensions pure Lovelock theories have Schrödinger solutions of arbitrary radius, on a co-dimension one locus in the Lovelock parameter space. This co-dimension one locus contains the subspace over which the Lovelock gravity can be written in the Chern–Simons form. Schrödinger solutions do not exist outside this locus and on this locus they exist for arbitrary dynamical exponent z. This freedom in z is due to the degeneracy in the configuration space. We show that this degeneracy survives certain deformation away from the Lovelock moduli space.

Exploring Lovelock theory moduli space for Schrödinger solutions

Science.gov (United States)

Jatkar, Dileep P.; Kundu, Nilay

2016-09-01

We look for Schrödinger solutions in Lovelock gravity in D > 4. We span the entire parameter space and determine parametric relations under which the Schrödinger solution exists. We find that in arbitrary dimensions pure Lovelock theories have Schrödinger solutions of arbitrary radius, on a co-dimension one locus in the Lovelock parameter space. This co-dimension one locus contains the subspace over which the Lovelock gravity can be written in the Chern-Simons form. Schrödinger solutions do not exist outside this locus and on this locus they exist for arbitrary dynamical exponent z. This freedom in z is due to the degeneracy in the configuration space. We show that this degeneracy survives certain deformation away from the Lovelock moduli space.

Isometries on Banach spaces function spaces

CERN Document Server

Fleming, Richard J

2002-01-01

Fundamental to the study of any mathematical structure is an understanding of its symmetries. In the class of Banach spaces, this leads naturally to a study of isometries-the linear transformations that preserve distances. In his foundational treatise, Banach showed that every linear isometry on the space of continuous functions on a compact metric space must transform a continuous function x into a continuous function y satisfying y(t) = h(t)x(p(t)), where p is a homeomorphism and |h| is identically one.Isometries on Banach Spaces: Function Spaces is the first of two planned volumes that survey investigations of Banach-space isometries. This volume emphasizes the characterization of isometries and focuses on establishing the type of explicit, canonical form given above in a variety of settings. After an introductory discussion of isometries in general, four chapters are devoted to describing the isometries on classical function spaces. The final chapter explores isometries on Banach algebras.This treatment p...

Atmospheric free-space coherent optical communications with adaptive optics

Science.gov (United States)

Ting, Chueh; Zhang, Chengyu; Yang, Zikai

2017-02-01

Free-space coherent optical communications have a potential application to offer last mile bottleneck solution in future local area networks (LAN) because of their information carrier, information security and license-free status. Coherent optical communication systems using orthogonal frequency division multiplexing (OFDM) digital modulation are successfully demonstrated in a long-haul tens Giga bits via optical fiber, but they are not yet available in free space due to atmospheric turbulence-induced channel fading. Adaptive optics is recognized as a promising technology to mitigate the effects of atmospheric turbulence in free-space optics. In this paper, a free-space coherent optical communication system using an OFDM digital modulation scheme and adaptive optics (FSO OFDM AO) is proposed, a Gamma-Gamma distribution statistical channel fading model for the FSO OFDM AO system is examined, and FSO OFDM AO system performance is evaluated in terms of bit error rate (BER) versus various propagation distances.

Space Network Time Distribution and Synchronization Protocol Development for Mars Proximity Link

Science.gov (United States)

Woo, Simon S.; Gao, Jay L.; Mills, David

2010-01-01

Time distribution and synchronization in deep space network are challenging due to long propagation delays, spacecraft movements, and relativistic effects. Further, the Network Time Protocol (NTP) designed for terrestrial networks may not work properly in space. In this work, we consider the time distribution protocol based on time message exchanges similar to Network Time Protocol (NTP). We present the Proximity-1 Space Link Interleaved Time Synchronization (PITS) algorithm that can work with the CCSDS Proximity-1 Space Data Link Protocol. The PITS algorithm provides faster time synchronization via two-way time transfer over proximity links, improves scalability as the number of spacecraft increase, lowers storage space requirement for collecting time samples, and is robust against packet loss and duplication which underlying protocol mechanisms provide.

Genomic and proteomic analysis of soybean heritable variations induced by space flight

Institute of Scientific and Technical Information of China (English)

HE Jie; GAO Yong; SUN Ye-qing

2009-01-01

To analyze the biological effects of space environment, the diversity of genomic DNA between the space flight soybean 194(4126) with phenotype of good yield and good fruit quality induced by space flight and the soybean with ground control was studied by amplified fragment length polymorphism (AFLP) method, and the polymorphism of space flight soybean 194(4126) was 3.56%. The differences of protein expression of seeds and leaves between the two kinds of soybeans were analysed by two-dimensional electrophoresis, PDQuest software and MALDI-TOF mass spectrometry. Results show that the loss and decrease of protein expression in 194(4126) soybean are subjected to the space fight of seeds, and three special proteins including Dehydrin, MAT1 and ceQORH are identified. It is concluded that the space environment changes the phenotype and geno-type of soybeans due to the space flight of seeds.

The Morse oscillator in position space, momentum space, and phase space

DEFF Research Database (Denmark)

Dahl, Jens Peder; Springborg, Michael

1988-01-01

We present a unified description of the position-space wave functions, the momentum-space wave functions, and the phase-space Wigner functions for the bound states of a Morse oscillator. By comparing with the functions for the harmonic oscillator the effects of anharmonicity are visualized....... Analytical expressions for the wave functions and the phase space functions are given, and it is demonstrated how a numerical problem arising from the summation of an alternating series in evaluating Laguerre functions can be circumvented. The method is applicable also for other problems where Laguerre...... functions are to be calculated. The wave and phase space functions are displayed in a series of curves and contour diagrams. An Appendix discusses the calculation of the modified Bessel functions of real, positive argument and complex order, which is required for calculating the phase space functions...

Radiation resistance of thin-film solar cells for space photovoltaic power

Science.gov (United States)

Woodyard, James R.; Landis, Geoffrey A.

1991-01-01

Copper indium diselenide, cadmium telluride, and amorphous silicon alloy solar cells have achieved noteworthy performance and are currently being studied for space power applications. Cadmium sulfide cells had been the subject of much effort but are no longer considered for space applications. A review is presented of what is known about the radiation degradation of thin film solar cells in space. Experimental cadmium telluride and amorphous silicon alloy cells are reviewed. Damage mechanisms and radiation induced defect generation and passivation in the amorphous silicon alloy cell are discussed in detail due to the greater amount of experimental data available.

Statistical Evaluation of Causal Factors Associated with Astronaut Shoulder Injury in Space Suits.

Science.gov (United States)

Anderson, Allison P; Newman, Dava J; Welsch, Roy E

2015-07-01

Shoulder injuries due to working inside the space suit are some of the most serious and debilitating injuries astronauts encounter. Space suit injuries occur primarily in the Neutral Buoyancy Laboratory (NBL) underwater training facility due to accumulated musculoskeletal stress. We quantitatively explored the underlying causal mechanisms of injury. Logistic regression was used to identify relevant space suit components, training environment variables, and anthropometric dimensions related to an increased propensity for space-suited injury. Two groups of subjects were analyzed: those whose reported shoulder incident is attributable to the NBL or working in the space suit, and those whose shoulder incidence began in active duty, meaning working in the suit could be a contributing factor. For both groups, percent of training performed in the space suit planar hard upper torso (HUT) was the most important predictor variable for injury. Frequency of training and recovery between training were also significant metrics. The most relevant anthropometric dimensions were bideltoid breadth, expanded chest depth, and shoulder circumference. Finally, record of previous injury was found to be a relevant predictor for subsequent injury. The first statistical model correctly identifies 39% of injured subjects, while the second model correctly identifies 68% of injured subjects. A review of the literature suggests this is the first work to quantitatively evaluate the hypothesized causal mechanisms of all space-suited shoulder injuries. Although limited in predictive capability, each of the identified variables can be monitored and modified operationally to reduce future impacts on an astronaut's health.

CO2 Effects in Space: Relationship to Intracranial Hypertension

Science.gov (United States)

Alexander, David J.

2011-01-01

This slide presentation reviews the effects of enhanced exposure to CO2 on Earth and in space. The effects of enhanced exposure to CO2 are experienced in almost all bodily systems. In space some of the effects are heightened due to the fluid shifts to the thorax and head. This fluid shift results in increased intracranial pressure, congested cerebral circulation, increased Cerebral Blood Flow (CBF) and Intravenous dilatation. The mechanism of the effect of CO2 on CBF is diagrammed, as is the Cerebrospinal Fluid (CSF) production. A listing of Neuroendocrine targets is included.

Dual spaces of local Morrey-type spaces

OpenAIRE

Gogatishvili, A. (Amiran); Mustafayev, R. (Rza)

2011-01-01

In this paper we show that associated spaces and dual spaces of the local Morrey-type spaces are so called complementary local Morrey-type spaces. Our method is based on an application of multidimensional reverse Hardy inequalities.

Analgesia para a sutura artroscópica do manguito rotador: estudo comparativo entre o bloqueio interescalênico do plexo braquial e o bloqueio da bursa subacromial contínuo Management of pain after the rotator cuff arthroscopic suture: comparative study among the interescalenic blockade and the continuous intrabursal infusion

Directory of Open Access Journals (Sweden)

Alexandre Almeida

2007-10-01

analyzed. Group I comprised patients who received interescalenic blockade with 0.75% ropivacaine. In group II, the same blockade was added with 150 µg of clonidine. In group III, a 30 ml bolus of 0.75% ropivacaine was administered to infiltrate the arthroscopic portals and directly in the subacromial space, followed by a continuous infusion of 0.2% ropivacaine with an infusion pump. The patients were submitted to the medication of the EAV analogue-visual scale 24 hours after the procedure. The variables studied were EAV, gender, size of the lesion, need of internal capsulotomy, and prevalence of side effects. The study evaluated 196 patients, 51 of whom were excluded, thus giving a total " n" = 145 patients. The total of patients in group I was 65, in group II, 19, and in group III, 61. RESULTS: The mean EAV index found for group I was 3.88 ± 1,737 (3; in group II, it was 3.8 ± 1.6 (3, and in group III, 1.95 ± 1.6 (2. There was a significant difference when comparing group I to group III (p < 0.001 and when comparing group II to group III (p < 0.001 suggesting less pain felt by patients in group III. There was no pain perception difference between genders (p = 0.700 and among the different sizes of rotator cuff lesion (p = 0.546. There was a pain perception difference between patients that were and those that were not submitted to internal capsulotomy (p = 0.038. There was reduced prevalence of nausea and/or vomiting (p = 0.089 and of pruritus (p = 0.092 in group III as compared to groups I and II. CONCLUSIONS: The protocol of postoperative analgesia with continuous infusion of ropivacaine showed that it is better than the protocols using morphine after the end of the interescalenic blockade effects. There was no difference in pain perception between the genders and according to different sizes of sutured lesions. There was a difference in pain perception by the patients who had and those who have not had internal capsulotomy. The rate of side effects was similar among

Emergence and expansion of cosmic space as due to M0-branes

Energy Technology Data Exchange (ETDEWEB)

Sepehri, Alireza, E-mail: alireza.sepehri@uk.ac.ir [Faculty of Physics, Shahid Bahonar University, P.O. Box 76175, Kerman (Iran, Islamic Republic of); Research Institute for Astronomy and Astrophysics of Maragha (RIAAM), P.O. Box 55134-441, Maragha (Iran, Islamic Republic of); Setare, Mohammad Reza, E-mail: rezakord@ipm.ir [Department of Science, University of Kurdistan, Campus of Bijar, Bijar (Iran, Islamic Republic of); Capozziello, Salvatore, E-mail: capozziello@na.infn.it [Dipartimento di Fisica, Universita di Napoli Federico II, 80126, Naples (Italy); INFN Sez. di Napoli, Compl. Univ. di Monte S. Angelo, Edificio G, 80126, Naples (Italy); Gran Sasso Science Institute (INFN), Viale F. Crispi, 7, 67100, L’Aquila (Italy)

2015-12-29

Recently, Padmanabhan discussed that the difference between the number of degrees of freedom on the boundary surface and the number of degrees of freedom in a bulk region causes the accelerated expansion of the universe. The main question arising is: what is the origin of this inequality between the surface degrees of freedom and the bulk degrees of freedom? We answer this question in M-theory. In our model, first M0-branes are compactified on one circle and ND0-branes are created. Then ND0-branes join each other, grow, and form one D5-branes. Next, the D5-brane is compactified on two circles and our universe’s D3-brane, two D1-branes and some extra energies are produced. After that, one of the D1-branes, which is closer to the universe’s brane, gives its energy into it, and this leads to an increase in the difference between the numbers of degrees of freedom and the occurring inflation era. With the disappearance of this D1-brane, the number of degrees of freedom of boundary surface and bulk region become equal and inflation ends. At this stage, extra energies that are produced due to the compactification cause an expansion of the universe and deceleration epoch. Finally, another D1-brane dissolves in our universe’s brane, leads to an inequality between degrees of freedom, and there occurs a new phase of acceleration.

Emergence and expansion of cosmic space as due to M0-branes

International Nuclear Information System (INIS)

Sepehri, Alireza; Setare, Mohammad Reza; Capozziello, Salvatore

2015-01-01

Recently, Padmanabhan discussed that the difference between the number of degrees of freedom on the boundary surface and the number of degrees of freedom in a bulk region causes the accelerated expansion of the universe. The main question arising is: what is the origin of this inequality between the surface degrees of freedom and the bulk degrees of freedom? We answer this question in M-theory. In our model, first M0-branes are compactified on one circle and ND0-branes are created. Then ND0-branes join each other, grow, and form one D5-branes. Next, the D5-brane is compactified on two circles and our universe’s D3-brane, two D1-branes and some extra energies are produced. After that, one of the D1-branes, which is closer to the universe’s brane, gives its energy into it, and this leads to an increase in the difference between the numbers of degrees of freedom and the occurring inflation era. With the disappearance of this D1-brane, the number of degrees of freedom of boundary surface and bulk region become equal and inflation ends. At this stage, extra energies that are produced due to the compactification cause an expansion of the universe and deceleration epoch. Finally, another D1-brane dissolves in our universe’s brane, leads to an inequality between degrees of freedom, and there occurs a new phase of acceleration

Scalable Solution Processing of Pristine Carbon Nanotubes for Self-Assembled, Tunable Materials with Direct Application to Space Technologies

Data.gov (United States)

National Aeronautics and Space Administration — Current material technologies limit space exploration and vehicle performance due to often unnecessary mass increase from copper wiring or heavy structural...

Banach spaces of continuous functions as dual spaces

CERN Document Server

Dales, H G; Lau, A T -M; Strauss, D

2016-01-01

This book gives a coherent account of the theory of Banach spaces and Banach lattices, using the spaces C_0(K) of continuous functions on a locally compact space K as the main example. The study of C_0(K) has been an important area of functional analysis for many years. It gives several new constructions, some involving Boolean rings, of this space as well as many results on the Stonean space of Boolean rings. The book also discusses when Banach spaces of continuous functions are dual spaces and when they are bidual spaces.

Due antichi quartieri romani sotto la lente di ingrandimento: un’analisi space syntax dei quartieri delle città antiche e della loro vita sociale

Directory of Open Access Journals (Sweden)

Stöger, Hanna

2015-12-01

Full Text Available Neighbourhoods and the social use of space are areas of growing interest. By combining archaeological methods and space syntax, the article offers new insights into the physical environment of daily life in the Roman city. The detailed examination of two city blocks from Ostia (Rome’s imperial port-town, allows the authors to identify spaces which fostered social cohesion and community building. The shared courtyards and passage spaces of Block IV ii suggest continued community focus (2nd - 5th centuries AD. In contrast, Block IV iv lacks common spaces and revealed self-contained buildings centred on individual access to public space. Block IV ii enjoyed shared spaces within its own perimeter, while Block IV iv looks toward external community building, with activities centred on the street confining the block. The results show the flexibility of Roman urban structures and allow for suggestive glimpses into the community that sustained the city in the long-term.El estudio de los vecindarios y el uso social del espacio habitado son temas de interés creciente. Mediante la combinación de métodos arqueológicos y space syntax, este artículo ofrece nuevas formas de analizar el entorno físico de la vida cotidiana en las ciudades romanas. El examen detallado de dos bloques urbanos en Ostia (la ciudad portuaria de Roma en época imperial nos ha permitido identificar espacios que fomentan la cohesión social y la vida en comunidad. El uso común de patios y pasillos en el Bloque IV ii sugiere un uso comunal continuado desde el siglo II hasta el siglo V d. C. En claro contraste con este sector, el Bloque IV iv no tiene espacios comunes y muestra edificios aislados con accesos individuales al espacio público. El Bloque IV ii disfruta de espacios compartidos dentro de su propio perímetro, mientras que el Bloque IV iv parece estar orientado por el interés de comunidades externas con actividades desarrolladas hacia la calle creando cierto aislamiento

Hypersonic sliding target tracking in near space

Directory of Open Access Journals (Sweden)

Xiang-yu Zhang

2015-12-01

Full Text Available To improve the tracking accuracy of hypersonic sliding target in near space, the influence of target hypersonic movement on radar detection and tracking is analyzed, and an IMM tracking algorithm is proposed based on radial velocity compensating and cancellation processing of high dynamic biases under the earth centered earth fixed (ECEF coordinate. Based on the analysis of effect of target hypersonic movement, a measurement model is constructed to reduce the filter divergence which is caused by the model mismatch. The high dynamic biases due to the target hypersonic movement are approximately compensated through radial velocity estimation to achieve the hypersonic target tracking at low systematic biases in near space. The high dynamic biases are further eliminated by the cancellation processing of different radars, in which the track association problem can be solved when the dynamic biases are low. An IMM algorithm based on constant acceleration (CA, constant turning (CT and Singer models is used to achieve the hypersonic sliding target tracking in near space. Simulation results show that the target tracking in near space can be achieved more effectively by using the proposed algorithm.

Space-Time Crystal and Space-Time Group.

Science.gov (United States)

Xu, Shenglong; Wu, Congjun

2018-03-02

Crystal structures and the Bloch theorem play a fundamental role in condensed matter physics. We extend the static crystal to the dynamic "space-time" crystal characterized by the general intertwined space-time periodicities in D+1 dimensions, which include both the static crystal and the Floquet crystal as special cases. A new group structure dubbed a "space-time" group is constructed to describe the discrete symmetries of a space-time crystal. Compared to space and magnetic groups, the space-time group is augmented by "time-screw" rotations and "time-glide" reflections involving fractional translations along the time direction. A complete classification of the 13 space-time groups in one-plus-one dimensions (1+1D) is performed. The Kramers-type degeneracy can arise from the glide time-reversal symmetry without the half-integer spinor structure, which constrains the winding number patterns of spectral dispersions. In 2+1D, nonsymmorphic space-time symmetries enforce spectral degeneracies, leading to protected Floquet semimetal states. We provide a general framework for further studying topological properties of the (D+1)-dimensional space-time crystal.

Fixed point theorems for generalized α -β-weakly contraction mappings in metric spaces and applications.

Science.gov (United States)

Latif, Abdul; Mongkolkeha, Chirasak; Sintunavarat, Wutiphol

2014-01-01

We extend the notion of generalized weakly contraction mappings due to Choudhury et al. (2011) to generalized α-β-weakly contraction mappings. We show with examples that our new class of mappings is a real generalization of several known classes of mappings. We also establish fixed point results for such mappings in metric spaces. Applying our new results, we obtain fixed point results on ordinary metric spaces, metric spaces endowed with an arbitrary binary relation, and metric spaces endowed with graph.

Increasing reliability and availability in smart spaces : a novel architecture for resource and service management

NARCIS (Netherlands)

Bhardwaj, S.; Ozcelebi, T.; Syed, Aly; Ozunlu, O.; Lukkien, J.J.

2012-01-01

Smart spaces are physical spaces where services provided by Consumer Electronics (CE) devices with varying resource availabilities work together to realize user-specific automated scenarios. These scenarios may be interrupted in case one of the services making up the scenario stops working, e.g. due

Massive subacromial-subdeltoid bursitis with rice bodies secondary to an orthopedic implant.

Science.gov (United States)

Urruela, Adriana M; Rapp, Timothy B; Egol, Kenneth A

2012-09-01

Both early and late complications following open reduction and internal fixation of proximal humerus fractures have been reported extensively in the literature. Although orthopedic implants are known to cause irritation and inflammation, to our knowledge, this is the first case report to describe a patient with rice bodies secondary to an orthopedic implant. Although the etiology of rice bodies is unclear, histological studies reveal that they are composed of an inner amorphous core surrounded by collagen and fibrin. The differential diagnosis in this case included synovial chondromatosis, infection, and the formation of a malignant tumor. Additional imaging studies, such as magnetic resonance imaging, and more specific tests were necessary to differentiate the rice bodies due to bursitis versus neoplasm, prior to excision. The patient presented 5 years following open reduction and internal fixation of a displaced proximal humerus fracture, with swelling in the area of the previous surgical site. Examination revealed a large, painless tumor-like mass on the anterior aspect of the shoulder. The patient's chief concern was the unpleasant aesthetic of the mass; no pain was reported. Upon excision of the mass, the patient's full, painless range of motion returned.

Emergence and expansion of cosmic space as due to M0-branes

Energy Technology Data Exchange (ETDEWEB)

Sepehri, Alireza [Shahid Bahonar University, Faculty of Physics, Kerman (Iran, Islamic Republic of); Research Institute for Astronomy and Astrophysics of Maragha (RIAAM), Maragha (Iran, Islamic Republic of); Setare, Mohammad Reza [University of Kurdistan, Department of Science, Bijar (Iran, Islamic Republic of); Capozziello, Salvatore [Universita di Napoli Federico II, Dipartimento di Fisica, Naples (Italy); Complutense Univ. di Monte S. Angelo, Naples (Italy); Gran Sasso Science Institute (INFN), L' Aquila (Italy); INFN Sezione di Napoli, Naples (Italy)

2015-12-15

Recently, Padmanabhan (arXiv:1206.4916 [hepth]) discussed that the difference between the number of degrees of freedom on the boundary surface and the number of degrees of freedom in a bulk region causes the accelerated expansion of the universe. The main question arising is: what is the origin of this inequality between the surface degrees of freedom and the bulk degrees of freedom? We answer this question in M-theory. In our model, first M0-branes are compactified on one circle and N D0-branes are created. Then N D0-branes join each other, grow, and form one D5-branes. Next, the D5-brane is compactified on two circles and our universe's D3-brane, two D1-branes and some extra energies are produced. After that, one of the D1-branes, which is closer to the universe's brane, gives its energy into it, and this leads to an increase in the difference between the numbers of degrees of freedom and the occurring inflation era. With the disappearance of this D1-brane, the number of degrees of freedom of boundary surface and bulk region become equal and inflation ends. At this stage, extra energies that are produced due to the compactification cause an expansion of the universe and deceleration epoch. Finally, another D1-brane dissolves in our universe's brane, leads to an inequality between degrees of freedom, and there occurs a new phase of acceleration. (orig.)

NewSpace: The Emerging Commercial Space Industry

Science.gov (United States)

Martin, Gary

2016-01-01

A lecture to students at the International Space University. Topics include: - We are at a turning point in the history of space exploration and development the cusp of a revolution, new industries are being born that use space in many non-traditional ways - The established military industrial space sector is no longer the only game in town - Increased competition and new capabilities will change the marketplace forever - Everyone interested in working in the space sector will be affected.

A stochastic space-time model for intermittent precipitation occurrences

KAUST Repository

Sun, Ying; Stein, Michael L.

2016-01-01

Modeling a precipitation field is challenging due to its intermittent and highly scale-dependent nature. Motivated by the features of high-frequency precipitation data from a network of rain gauges, we propose a threshold space-time t random field (tRF) model for 15-minute precipitation occurrences. This model is constructed through a space-time Gaussian random field (GRF) with random scaling varying along time or space and time. It can be viewed as a generalization of the purely spatial tRF, and has a hierarchical representation that allows for Bayesian interpretation. Developing appropriate tools for evaluating precipitation models is a crucial part of the model-building process, and we focus on evaluating whether models can produce the observed conditional dry and rain probabilities given that some set of neighboring sites all have rain or all have no rain. These conditional probabilities show that the proposed space-time model has noticeable improvements in some characteristics of joint rainfall occurrences for the data we have considered.

A stochastic space-time model for intermittent precipitation occurrences

KAUST Repository

Sun, Ying

2016-01-28

Modeling a precipitation field is challenging due to its intermittent and highly scale-dependent nature. Motivated by the features of high-frequency precipitation data from a network of rain gauges, we propose a threshold space-time t random field (tRF) model for 15-minute precipitation occurrences. This model is constructed through a space-time Gaussian random field (GRF) with random scaling varying along time or space and time. It can be viewed as a generalization of the purely spatial tRF, and has a hierarchical representation that allows for Bayesian interpretation. Developing appropriate tools for evaluating precipitation models is a crucial part of the model-building process, and we focus on evaluating whether models can produce the observed conditional dry and rain probabilities given that some set of neighboring sites all have rain or all have no rain. These conditional probabilities show that the proposed space-time model has noticeable improvements in some characteristics of joint rainfall occurrences for the data we have considered.

Neoplastic and proliferative disorders of the perinephric space

International Nuclear Information System (INIS)

Heller, M.T.; Haarer, K.A.; Thomas, E.; Thaete, F.L.

2012-01-01

The perinephric space is a well-marginated central compartment of the retroperitoneum, located between the anterior and posterior pararenal spaces. Various neoplastic and proliferative disorders can affect the perinephric space, and there is a wide array of imaging findings. Although many perinephric lesions may extend directly from the kidney and adrenal gland, other lesions occur in the perinephric space due to haematogenous spread, as part of a systemic disease, or by extension from an adjacent retroperitoneal compartment. Imaging plays a pivotal role in the diagnosis of perinephric diseases, as many of the disease processes affecting this space will not result in clinical signs or symptoms until the disease is at an advanced stage. Despite the often shared non-specific clinical and imaging findings among these disease processes, application of a categorical differential diagnosis based on the imaging characteristics will serve to narrow the differential diagnosis and direct further evaluation and treatment. In this article, the lesions have been categorized as soft-tissue rind [nephroblastomatosis, fibrosis, Erdheim–Chester disease (ECD), extramedullary haematopoiesis, lymphoma, infiltrating metastases], focal solid lesions (extension of renal or adrenal malignancies, melanoma metastases, treated lymphoma), fat-containing lesions (angiomyolipoma, liposarcoma, myelolipoma), and cystic lesions (lymphangiomas, abscesses). The aim of this article is to demonstrate and describe the key imaging features of several neoplastic and proliferative disorders that affect the perinephric space.

Increasing reliability and availability in smart spaces : a novel architecture for resource and service management

NARCIS (Netherlands)

Bhardwaj, S.; Ozcelebi, T.; Ozunlu, O.; Lukkien, J.J.

2012-01-01

Smart spaces are physical spaces where services provided by Consumer Electronics (CE) devices with varying resource availabilities work together to realize user-specific automated scenarios. These scenarios may be interrupted in case one of the services making up the scenario stops, e.g. due to lack

Preparing future space leaders - International Space University

Science.gov (United States)

Stone, Barbara A.; Van Reeth, George P.

1992-01-01

The International Space University (ISU) concept of developing a cadre of space professionals that will lead the universities and industries into space is discussed. ISU is an innovative, permanent worldwide organization for training and academic instruction in all aspects of space studies. ISU's major goal is to provide the young professional academic instruction in technical and nontechnical areas of modern space exploration and research, and a forum to exchange ideas and develop both personal and professional ties at an international level.

Computation and empirical modeling of UV flux reaching Arabian Sea due to O3 hole

International Nuclear Information System (INIS)

Yousufzai, M. Ayub Khan

2008-01-01

Scientific organizations the world over, such as the European Space Agency, the North Atlantic Treaty Organization, the National Aeronautics and Space Administration, and the United Nations Organization, are deeply concerned about the imbalances, caused to a significant extent due to human interference in the natural make-up of the earth's ecosystem. In particular, ozone layer depletion (OLD) over the South Pole is already a serious hazard. The long-term effect of ozone layer depletion appears to be an increase in the ultraviolet radiation reaching the earth. In order to understand the effects of ozone layer depletion, investigations have been initiated by various research groups. However, to the best of our knowledge, there does not seem to be available any work treating the problem of computing and constructing an empirical model for the UV flux reaching the Arabian Sea surface due to the O3 hole. The communication presents the results of quantifying UV flux and modeling future estimation using time series analysis in a local context to understand the nature of the depletion. (author)

Characteristics of level-spacing statistics in chaotic graphene billiards.

Science.gov (United States)

Huang, Liang; Lai, Ying-Cheng; Grebogi, Celso

2011-03-01

A fundamental result in nonrelativistic quantum nonlinear dynamics is that the spectral statistics of quantum systems that possess no geometric symmetry, but whose classical dynamics are chaotic, are described by those of the Gaussian orthogonal ensemble (GOE) or the Gaussian unitary ensemble (GUE), in the presence or absence of time-reversal symmetry, respectively. For massless spin-half particles such as neutrinos in relativistic quantum mechanics in a chaotic billiard, the seminal work of Berry and Mondragon established the GUE nature of the level-spacing statistics, due to the combination of the chirality of Dirac particles and the confinement, which breaks the time-reversal symmetry. A question is whether the GOE or the GUE statistics can be observed in experimentally accessible, relativistic quantum systems. We demonstrate, using graphene confinements in which the quasiparticle motions are governed by the Dirac equation in the low-energy regime, that the level-spacing statistics are persistently those of GOE random matrices. We present extensive numerical evidence obtained from the tight-binding approach and a physical explanation for the GOE statistics. We also find that the presence of a weak magnetic field switches the statistics to those of GUE. For a strong magnetic field, Landau levels become influential, causing the level-spacing distribution to deviate markedly from the random-matrix predictions. Issues addressed also include the effects of a number of realistic factors on level-spacing statistics such as next nearest-neighbor interactions, different lattice orientations, enhanced hopping energy for atoms on the boundary, and staggered potential due to graphene-substrate interactions.

Space-charge-mediated anomalous ferroelectric switching in P(VDF-TrEE) polymer films

KAUST Repository

Hu, Weijin

2014-11-12

We report on the switching dynamics of P(VDF-TrEE) copolymer devices and the realization of additional substable ferroelectric states via modulation of the coupling between polarizations and space charges. The space-charge-limited current is revealed to be the dominant leakage mechanism in such organic ferroelectric devices, and electrostatic interactions due to space charges lead to the emergence of anomalous ferroelectric loops. The reliable control of ferroelectric switching in P(VDF-TrEE) copolymers opens doors toward engineering advanced organic memories with tailored switching characteristics.

Fixed Point Theorems for Generalized α-β-Weakly Contraction Mappings in Metric Spaces and Applications

Directory of Open Access Journals (Sweden)

Abdul Latif

2014-01-01

Full Text Available We extend the notion of generalized weakly contraction mappings due to Choudhury et al. (2011 to generalized α-β-weakly contraction mappings. We show with examples that our new class of mappings is a real generalization of several known classes of mappings. We also establish fixed point results for such mappings in metric spaces. Applying our new results, we obtain fixed point results on ordinary metric spaces, metric spaces endowed with an arbitrary binary relation, and metric spaces endowed with graph.

Yearbook on space policy 2015 access to space and the evolution of space activities

CERN Document Server

Baranes, Blandina; Hulsroj, Peter; Lahcen, Arne

2017-01-01

The Yearbook on Space Policy, edited by the European Space Policy Institute (ESPI), is the reference publication analysing space policy developments. Each year it presents issues and trends in space policy and the space sector as a whole. Its scope is global and its perspective is European. The Yearbook also links space policy with other policy areas. It highlights specific events and issues, and provides useful insights, data and information on space activities. The first part of the Yearbook sets out a comprehensive overview of the economic, political, technological and institutional trends that have affected space activities. The second part of the Yearbook offers a more analytical perspective on the yearly ESPI theme and consists of external contributions written by professionals with diverse backgrounds and areas of expertise. The third part of the Yearbook carries forward the character of the Yearbook as an archive of space activities. The Yearbook is designed for government decision-makers and agencies...

Due diligence

International Nuclear Information System (INIS)

Sanghera, G.S.

1999-01-01

The Occupational Health and Safety (OHS) Act requires that every employer shall ensure the health and safety of workers in the workplace. Issues regarding the practices at workplaces and how they should reflect the standards of due diligence were discussed. Due diligence was described as being the need for employers to identify hazards in the workplace and to take active steps to prevent workers from potentially dangerous incidents. The paper discussed various aspects of due diligence including policy, training, procedures, measurement and enforcement. The consequences of contravening the OHS Act were also described

The Engineering Workforce of Tomorrow - The Integrated Space Engineer

DEFF Research Database (Denmark)

Nielsen, Jens Frederik Dalsgaard

2007-01-01

The space engineer of tomorrow needs a variety of skills ranging from high specialized knowledge to cooperative capacities and the ability to understand and even to a certain degree to be productive outside their specialized skills. Newly educated engineers often lack many of these skills due...

Space Science in Action: Space Exploration [Videotape].

Science.gov (United States)

1999

In this videotape recording, students learn about the human quest to discover what is out in space. Students see the challenges and benefits of space exploration including the development of rocket science, a look back at the space race, and a history of manned space travel. A special section on the Saturn V rocket gives students insight into the…

Multipliers for continuous frames in Hilbert spaces

International Nuclear Information System (INIS)

Balazs, P; Bayer, D; Rahimi, A

2012-01-01

In this paper, we examine the general theory of continuous frame multipliers in Hilbert space. These operators are a generalization of the widely used notion of (discrete) frame multipliers. Well-known examples include anti-Wick operators, STFT multipliers or Calderón–Toeplitz operators. Due to the possible peculiarities of the underlying measure spaces, continuous frames do not behave quite as their discrete counterparts. Nonetheless, many results similar to the discrete case are proven for continuous frame multipliers as well, for instance compactness and Schatten-class properties. Furthermore, the concepts of controlled and weighted frames are transferred to the continuous setting. This article is part of a special issue of Journal of Physics A: Mathematical and Theoretical devoted to ‘Coherent states: mathematical and physical aspects’. (paper)

Reducing Human Radiation Risks on Deep Space Missions

Science.gov (United States)

2017-09-01

101 Figure 49. Human Health, Life Support, and Habitation System...2013). These same studies reveal that for astronauts returning home, this may result in significant loss of lifespan and quality of life due to...warnings to the satellites in orbit at either planet , or to spacecraft in transit (Phys.org 2010). C. IMPROVEMENTS TO MEASUREMENTS OF SPACE RADIATION

Bronchopleural cutaneous fistula due to Eikenella corrodens.

Science.gov (United States)

Wong, Kin-Sun; Huang, Yhu-Chering

2005-01-01

The aim of this paper is to review the subject and to report on and discuss a case of bronchopleural cutaneous fistula due to Eikenella corrodens. A 16-year-old girl was brought to our hospital with fever and blood-tinged sputum 2 weeks prior to her admission. She suffered from neurologic sequelae of herpetic encephalitis and had been bed-ridden since 5 years of age. A longitudinal paraspinal soft mass had been noted in the previous week by her mother. She had been given oral feeding despite frequent choking for the past few years. On palpation, the mass can be squeezed to follow the least resistance of subcutaneous space longitudinally extending to the lower thoracic region. Chest computed tomography scan revealed right lower lobe necrotizing pneumonitis and a pleuro-cutaneous fistula leading to the subcutaneous air locules. A protracted course of antibiotics was prescribed and subcutaneous air trapping decreased in size over 8 weeks. Eikenella corrodens has increasingly been implicated as a potential causative pathogen in pleuropulmonary infections. Pleuro-cutaneous fistula and abscess formation complicating empyema and necrotizing pneumonitis due to E. corrodens infection have not been reported. A bulging thoracic subcutaneous lesion waxes and wanes with respiration suggest the possibility of a pleruo-cutaneous fistula. Treatment of Eikenella empyema using antibiotics without surgical decortication requires a prolonged course of antibiotic therapy.

Students’ misconceptions about Newton's second law in outer space

International Nuclear Information System (INIS)

Temiz, B K; Yavuz, A

2014-01-01

Students’ misconceptions about Newton's second law in frictionless outer space were investigated. The research was formed according to an epistemic game theoretical framework. The term ‘epistemic’ refers to students’ participation in problem-solving activities as a means of constructing new knowledge. The term ‘game’ refers to a coherent activity that consists of moves and rules. A set of questions in which students are asked to solve two similar Newton's second law problems, one of which is on the Earth and the other in outer space, was administered to 116 undergraduate students. The findings indicate that there is a significant difference between students’ epistemic game preferences and race-type (outer space or frictional surface) question. So students who used Newton's second law on the ground did not apply this law and used primitive reasoning when it came to space. Among these students, voluntary interviews were conducted with 18 students. Analysis of interview transcripts showed that: (1) the term ‘space’ causes spontaneity among students that prevents the use of the law; (2) students hesitate to apply Newton's second law in space due to the lack of a condition—the friction; (3) students feel that Newton's second law is not valid in space for a variety of reasons, but mostly for the fact that the body in space is not in contact with a surface. (paper)

High-definition velocity-space tomography of fast-ion dynamics

DEFF Research Database (Denmark)

Salewski, Mirko; Geiger, B.; Jacobsen, A.S.

2016-01-01

Velocity-space tomography of the fast-ion distribution function in a fusion plasma is usually a photon-starved tomography method due to limited optical access and signal-to-noise ratio of fast-ion Dα (FIDA) spectroscopy as well as the strive for high-resolution images. In high-definition tomography...... information to reconstruct where in velocity space the measurements and the simulation disagree. This alternative approach is demonstrated for four-view as well as for two-view FIDA measurements. The high-definition tomography tools allow us to study fast ions in sawtoothing plasmas and the formation of NBI...

Drugs in space: Pharmacokinetics and pharmacodynamics in astronauts.

Science.gov (United States)

Kast, Johannes; Yu, Yichao; Seubert, Christoph N; Wotring, Virginia E; Derendorf, Hartmut

2017-11-15

Space agencies are working intensely to push the current boundaries of human spaceflight by sending astronauts deeper into space than ever before, including missions to Mars and asteroids. Spaceflight alters human physiology due to fluid shifts, muscle and bone loss, immune system dysregulation, and changes in the gastrointestinal tract and metabolic enzymes. These alterations may change the pharmacokinetics and/or pharmacodynamics of medications used by astronauts and subsequently might impact drug efficacy and safety. Most commonly, medications are administered during space missions to treat sleep disturbances, allergies, space motion sickness, pain, and sinus congestion. These medications are administered under the assumption that they act in a similar way as on Earth, an assumption that has not been investigated systematically yet. Few inflight pharmacokinetic data have been published, and pharmacodynamic and pharmacokinetic/pharmacodynamic studies during spaceflight are also lacking. Therefore, bed-rest models are often used to simulate physiological changes observed during microgravity. In addition to pharmacokinetic/pharmacodynamic changes, decreased drug and formulation stability in space could also influence efficacy and safety of medications. These alterations along with physiological changes and their resulting pharmacokinetic and pharmacodynamic effects must to be considered to determine their ultimate impact on medication efficacy and safety during spaceflight. Copyright © 2017 Elsevier B.V. All rights reserved.

Twistor space, Minkowski space and the conformal group

International Nuclear Information System (INIS)

Broek, P.M. van den

1983-01-01

It is shown that the conformal group of compactified Minkowski space is isomorphic to a group of rays of semilinear transformations of twistor space. The action of the conformal group on twistor space is given by an explicit realisation of this isomorphism. In this way we determine the transformation of twistor space under space inversion and time inversion. (orig.)

On the Response of Halophilic Archaea to Space Conditions

Science.gov (United States)

Leuko, Stefan; Rettberg, Petra; Pontifex, Ashleigh L.; Burns, Brendan P.

2014-01-01

Microorganisms are ubiquitous and can be found in almost every habitat and ecological niche on Earth. They thrive and survive in a broad spectrum of environments and adapt to rapidly changing external conditions. It is of great interest to investigate how microbes adapt to different extreme environments and with modern human space travel, we added a new extreme environment: outer space. Within the last 50 years, technology has provided tools for transporting microbial life beyond Earth’s protective shield in order to study in situ responses to selected conditions of space. This review will focus on halophilic archaea, as, due to their ability to survive in extremes, they are often considered a model group of organisms to study responses to the harsh conditions associated with space. We discuss ground-based simulations, as well as space experiments, utilizing archaea, examining responses and/or resistance to the effects of microgravity and UV in particular. Several halophilic archaea (e.g., Halorubrum chaoviator) have been exposed to simulated and actual space conditions and their survival has been determined as well as the protective effects of halite shown. Finally, the intriguing potential of archaea to survive on other planets or embedded in a meteorite is postulated. PMID:25370029

On the Response of Halophilic Archaea to Space Conditions

Directory of Open Access Journals (Sweden)

Stefan Leuko

2014-02-01

Full Text Available Microorganisms are ubiquitous and can be found in almost every habitat and ecological niche on Earth. They thrive and survive in a broad spectrum of environments and adapt to rapidly changing external conditions. It is of great interest to investigate how microbes adapt to different extreme environments and with modern human space travel, we added a new extreme environment: outer space. Within the last 50 years, technology has provided tools for transporting microbial life beyond Earth’s protective shield in order to study in situ responses to selected conditions of space. This review will focus on halophilic archaea, as, due to their ability to survive in extremes, they are often considered a model group of organisms to study responses to the harsh conditions associated with space. We discuss ground-based simulations, as well as space experiments, utilizing archaea, examining responses and/or resistance to the effects of microgravity and UV in particular. Several halophilic archaea (e.g., Halorubrum chaoviator have been exposed to simulated and actual space conditions and their survival has been determined as well as the protective effects of halite shown. Finally, the intriguing potential of archaea to survive on other planets or embedded in a meteorite is postulated.

A new chapter in doctoral candidate training: The Helmholtz Space Life Sciences Research School (SpaceLife)

Science.gov (United States)

Hellweg, C. E.; Gerzer, R.; Reitz, G.

2011-05-01

In the field of space life sciences, the demand of an interdisciplinary and specific training of young researchers is high due to the complex interaction of medical, biological, physical, technical and other questions. The Helmholtz Space Life Sciences Research School (SpaceLife) offers an excellent interdisciplinary training for doctoral students from different fields (biology, biochemistry, biotechnology, physics, psychology, nutrition or sports sciences and related fields) and any country. SpaceLife is coordinated by the Institute of Aerospace Medicine at the German Aerospace Center (DLR) in Cologne. The German Universities in Kiel, Bonn, Aachen, Regensburg, Magdeburg and Berlin, and the German Sports University (DSHS) in Cologne are members of SpaceLife. The Universities of Erlangen-Nürnberg, Frankfurt, Hohenheim, and the Beihang University in Beijing are associated partners. In each generation, up to 25 students can participate in the three-year program. Students learn to develop integrated concepts to solve health issues in human spaceflight and in related disease patterns on Earth, and to further explore the requirements for life in extreme environments, enabling a better understanding of the ecosystem Earth and the search for life on other planets in unmanned and manned missions. The doctoral candidates are coached by two specialist supervisors from DLR and the partner university, and a mentor. All students attend lectures in different subfields of space life sciences to attain an overview of the field: radiation and gravitational biology, astrobiology and space physiology, including psychological aspects of short and long term space missions. Seminars, advanced lectures, laboratory courses and stays at labs at the partner institutions or abroad are offered as elective course and will provide in-depth knowledge of the chosen subfield or allow to appropriate innovative methods. In Journal Clubs of the participating working groups, doctoral students learn

A segmented appliance for space closure followed by Invisalign and fixed appliances.

Science.gov (United States)

Uribe, Flavio; Cutrera, Alice; Nanda, Ravinda

2011-01-01

This case report describes the use of a segmented appliance for space closure prior to using Invisalign. The maxillary right canine was retracted into the extracted first premolar space with a sectional wire from the first molar to the canine with no visible brackets in the incisor region. The advantage of this technique is the ability to achieve better root and rotational control during space closure with a fixed appliance that also has limited visibility. A maxillary fixed appliance was used to refine the esthetics in the maxillary arch due to the limitations of the Invisalign appliance in achieving rotational and vertical movements.

Unified Communications for Space Inventory Management

Science.gov (United States)

Gifford, Kevin K.; Fink, Patrick W.; Barton, Richard; Ngo, Phong H.

2009-01-01

To help assure mission success for long-duration exploration activities, NASA is actively pursuing wireless technologies that promote situational awareness and autonomy. Wireless technologies are typically extensible, offer freedom from wire tethers, readily support redundancy, offer potential for decreased wire weight, and can represent dissimilar implementation for increased reliability. In addition, wireless technologies can enable additional situational awareness that otherwise would be infeasible. For example, addition of wired sensors, the need for which might not have been apparent at the outset of a program, night be extremely costly due in part to the necessary routing of cables through the vehicle. RFID, or radio frequency identification, is a wireless technology with the potential for significant savings and increased reliability and safety in space operations. Perhaps the most obvious savings relate to the application of inventory management. A fully automated inventory management system is highly desirable for long-term sustaining operations in space environments. This assertion is evidenced by inventory activities on the International Space Station, which represents the most extensive inventory tracking experience base in the history of space operations. In the short tern, handheld RFID readers offer substantial savings owing to reduced crew time for inventory audits. Over the long term, a combination of improved RFID technology and operational concepts modified to fully utilize the technology should result in space based inventory management that is highly reliable and requires very little crew time. In addition to inventory management, RFID is likely to find space applications in real-time location and tracking systems. These could vary from coarse-resolution RFID portals to the high resolution afforded by ultra-wideband (UWB) RFID. Longer range RFID technologies that leverage passive surface acoustic wave (SAW) devices are being investigated to

Real-space quasilinear theory of drift waves in a sheared magnetic field

International Nuclear Information System (INIS)

1977-02-01

A real-space quasilinear theory is developed for the collisional and the collisionless drift waves in a plasma with a sheared magnetic field of slab geometry. The equation obtained describes the interaction between many localized modes around different rational surfaces through the density modulation of the energy source region of each mode. The wave amplitudes approach to the stationary values through a relaxation oscillation process. When the width x sub(s) of the energy source region becomes comparable to the spacing Δx of the two adjacent rational surfaces, diffusion coefficient due to the wave is enhanced over the classical value, while the nonlocal heat transport due to the wave propagation is shown to be negligible compared to that associated with the diffusion process. (auth.)

Pathological muscle activation patterns in patients with massive rotator cuff tears, with and without subacromial anaesthetics.

NARCIS (Netherlands)

Steenbrink, F.; Groot, J.H.; Veeger, H.E.J.; Meskers, C.G.M.; van de Sande, M.A.; Rozing, P.M.

2006-01-01

A mechanical deficit due to a massive rotator cuff tear is generally concurrent to a pain-induced decrease of maximum arm elevation and peak elevation torque. The purpose of this study was to measure shoulder muscle coordination in patients with massive cuff tears, including the effect of

Spinor Field Nonlinearity and Space-Time Geometry

Science.gov (United States)

Saha, Bijan

2018-03-01

Within the scope of Bianchi type VI,VI0,V, III, I, LRSBI and FRW cosmological models we have studied the role of nonlinear spinor field on the evolution of the Universe and the spinor field itself. It was found that due to the presence of non-trivial non-diagonal components of the energy-momentum tensor of the spinor field in the anisotropic space-time, there occur some severe restrictions both on the metric functions and on the components of the spinor field. In this report we have considered a polynomial nonlinearity which is a function of invariants constructed from the bilinear spinor forms. It is found that in case of a Bianchi type-VI space-time, depending of the sign of self-coupling constants, the model allows either late time acceleration or oscillatory mode of evolution. In case of a Bianchi VI 0 type space-time due to the specific behavior of the spinor field we have two different scenarios. In one case the invariants constructed from bilinear spinor forms become trivial, thus giving rise to a massless and linear spinor field Lagrangian. This case is equivalent to the vacuum solution of the Bianchi VI 0 type space-time. The second case allows non-vanishing massive and nonlinear terms and depending on the sign of coupling constants gives rise to accelerating mode of expansion or the one that after obtaining some maximum value contracts and ends in big crunch, consequently generating space-time singularity. In case of a Bianchi type-V model there occur two possibilities. In one case we found that the metric functions are similar to each other. In this case the Universe expands with acceleration if the self-coupling constant is taken to be a positive one, whereas a negative coupling constant gives rise to a cyclic or periodic solution. In the second case the spinor mass and the spinor field nonlinearity vanish and the Universe expands linearly in time. In case of a Bianchi type-III model the space-time remains locally rotationally symmetric all the time

Functional Interpretation of Neighborhood Public Spaces in Terms of Identity

Directory of Open Access Journals (Sweden)

Hamid Majedi

2015-03-01

Full Text Available The aim of this article is to evaluate the effect of neighborhood public space transformation due to rapid urbanization in Tehran since 1960s, on the formation of neighborhood identity. In order to find the role of public spaces in enhancing neighborhood identities, two middle class neighborhoods with different spatial organizations are compared with each other: Nazi Abad a planned neighborhood and Mehran a typical unplanned neighborhood which developed through rapid urbanization.   Next, the effect of neighborhood public spaces on neighborhood inhabitants is evaluated from two perspectives: Perceptual dimension and social dimension. The findings indicate that planned spatial organization and various neighborhood public spaces result in stronger neighborhood identity. It enhances both perceptual dimension of neighborhood identity(place attachment and its social dimension (sense of community. In contrast unplanned spatial organization which is the typical feature of Tehran neighborhoods leads to weak neighborhood identity.

Scattering Effects of Solar Panels on Space Station Antenna Performance

Science.gov (United States)

Panneton, Robert J.; Ngo, John C.; Hwu, Shian U.; Johnson, Larry A.; Elmore, James D.; Lu, Ba P.; Kelley, James S.

1994-01-01

Characterizing the scattering properties of the solar array panels is important in predicting Space Station antenna performance. A series of far-field, near-field, and radar cross section (RCS) scattering measurements were performed at S-Band and Ku-Band microwave frequencies on Space Station solar array panels. Based on investigation of the measured scattering patterns, the solar array panels exhibit similar scattering properties to that of the same size aluminum or copper panel mockup. As a first order approximation, and for worse case interference simulation, the solar array panels may be modeled using perfect reflecting plates. Numerical results obtained using the Geometrical Theory of Diffraction (GTD) modeling technique are presented for Space Station antenna pattern degradation due to solar panel interference. The computational and experimental techniques presented in this paper are applicable for antennas mounted on other platforms such as ship, aircraft, satellite, and space or land vehicle.

Real-space and reciprocal-space Berry phases in the Hall effect of Mn(1-x)Fe(x)Si.

Science.gov (United States)

Franz, C; Freimuth, F; Bauer, A; Ritz, R; Schnarr, C; Duvinage, C; Adams, T; Blügel, S; Rosch, A; Mokrousov, Y; Pfleiderer, C

2014-05-09

We report an experimental and computational study of the Hall effect in Mn(1-x)Fe(x)Si, as complemented by measurements in Mn(1-x)Co(x)Si, when helimagnetic order is suppressed under substitutional doping. For small x the anomalous Hall effect (AHE) and the topological Hall effect (THE) change sign. Under larger doping the AHE remains small and consistent with the magnetization, while the THE grows by over a factor of 10. Both the sign and the magnitude of the AHE and the THE are in excellent agreement with calculations based on density functional theory. Our study provides the long-sought material-specific microscopic justification that, while the AHE is due to the reciprocal-space Berry curvature, the THE originates in real-space Berry phases.

Space Sustainment: A New Approach for America in Space

Science.gov (United States)

2014-12-01

international community toward promoting market incentives in international space law. This would open up the competitive space for new entrants ...announces- new -space-situational-awareness-satellite-program.aspx. 29. Gruss, “U.S. Space Assets Face Growing Threat .” 30. McDougall, Heavens and the...November–December 2014 Air & Space Power Journal | 117 SCHRIEVER ESSAY WINNER SECOND PLACE Space Sustainment A New Approach for America in Space Lt

Multifunctional Carbon Nanotube/Polyethylene Complex Composites for Space Radiation Shielding, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — Polyethylene (PE), due to its high hydrogen content relative to its weight, has been identified by NASA as a promising radiation shielding material against galactic...

Deciphering cancer heterogeneity: the biological space

Directory of Open Access Journals (Sweden)

Stephanie eRoessler

2014-04-01

Full Text Available Most lethal solid tumors including hepatocellular carcinoma (HCC are considered incurable due to extensive heterogeneity in clinical presentation and tumor biology. Tumor heterogeneity may result from different cells of origin, patient ethnicity, etiology, underlying disease and diversity of genomic and epigenomic changes which drive tumor development. Cancer genomic heterogeneity thereby impedes treatment options and poses a significant challenge to cancer management. Studies of the HCC genome have revealed that although various genomic signatures identified in different HCC subgroups share a common prognosis, each carries unique molecular changes which are linked to different sets of cancer hallmarks whose misregulation has been proposed by Hanahan and Weinberg to be essential for tumorigenesis. We hypothesize that these specific sets of cancer hallmarks collectively occupy different tumor biological space representing the misregulation of different biological processes. In principle, a combination of different cancer hallmarks can result in new convergent molecular networks that are unique to each tumor subgroup and represent ideal druggable targets. Due to the ability of the tumor to adapt to external factors such as treatment or changes in the tumor microenvironment, the tumor biological space is elastic. Our ability to identify distinct groups of cancer patients with similar tumor biology who are most likely to respond to a specific therapy would have a significant impact on improving patient outcome. It is currently a challenge to identify a particular hallmark or a newly emerged convergent molecular network for a particular tumor. Thus, it is anticipated that the integration of multiple levels of data such as genomic mutations, somatic copy number aberration, gene expression, proteomics, and metabolomics, may help us grasp the tumor biological space occupied by each individual, leading to improved therapeutic intervention and outcome.

Compaction of PDMS due to proton beam irradiation

International Nuclear Information System (INIS)

Szilasi, S.Z.; Huszank, R.; Rajta, I.; Kokavecz, J.

2011-01-01

Complete text of publication follows. This work is about the detailed investigation of the changes of the surface topography, the degree of compaction/shrinkage and its relation to the irradiation fluence and the structure spacing in poly(dimethylsiloxane) (PDMS) patterned with 2 MeV proton microbeam. Sylgard 184 kit (Dow-Corning) was used to create the PDMS samples. The density of the PDMS samples was determined with pycnometer. The penetration depth for 2 MeV protons is ∼85 μm, the PDMS layer was ∼95 μm thick, so the incident protons stop in the PDMS, they do not reach the substrate. The irradiations have been performed at the nuclear microprobe facility at ATOMKI. The irradiated periodic structures consisted of parallel lines with different widths and spacing. To achieve different degrees of compaction, each structure was irradiated with five different fluences. The surface topography, the phase modification of the surface, and the connection between them were revealed using an atomic force microscope (AFM PSIA XE 100). The shrinkage data were obtained from the topography images. The structures with different line widths and spacing show different degrees of compaction as a function of irradiation fluence. By plotting them in the same graph (Fig. 1) it is clearly seen that the degree of compaction depends on both the irradiation fluence and the distance of the structures. The fluence dependence of the compaction can be explained with the chemical changes of PDMS. When an energetic ion penetrates through the material it scissions the polymer chain, whereupon among other things volatile products form. In the case of PDMS, these are mainly hydrogen, methane and ethane gases that can be released from PDMS. The irradiated volume shrinks due to significant structural change during which silicate derivatives (SiO x ) are formed. The phase change and the corresponding surface topography was compared and studied at all applied irradiation fluences. It was concluded

NASA Space Environments Technical Discipline Team Space Weather Activities

Science.gov (United States)

Minow, J. I.; Nicholas, A. C.; Parker, L. N.; Xapsos, M.; Walker, P. W.; Stauffer, C.

2017-12-01

The Space Environment Technical Discipline Team (TDT) is a technical organization led by NASA's Technical Fellow for Space Environments that supports NASA's Office of the Chief Engineer through the NASA Engineering and Safety Center. The Space Environments TDT conducts independent technical assessments related to the space environment and space weather impacts on spacecraft for NASA programs and provides technical expertise to NASA management and programs where required. This presentation will highlight the status of applied space weather activities within the Space Environment TDT that support development of operational space weather applications and a better understanding of the impacts of space weather on space systems. We will first discuss a tool that has been developed for evaluating space weather launch constraints that are used to protect launch vehicles from hazardous space weather. We then describe an effort to better characterize three-dimensional radiation transport for CubeSat spacecraft and processing of micro-dosimeter data from the International Space Station which the team plans to make available to the space science community. Finally, we will conclude with a quick description of an effort to maintain access to the real-time solar wind data provided by the Advanced Composition Explorer satellite at the Sun-Earth L1 point.

Compact space-like hypersurfaces in de Sitter space

OpenAIRE

Lv, Jinchi

2005-01-01

We present some integral formulas for compact space-like hypersurfaces in de Sitter space and some equivalent characterizations for totally umbilical compact space-like hypersurfaces in de Sitter space in terms of mean curvature and higher-order mean curvatures.

Numerical simulation of amplification of space charge waves in n-InP films

International Nuclear Information System (INIS)

Garcia-Barrientos, Abel; Palankovski, Vassil

2011-01-01

The non-linear interaction of space charge waves including the amplification in microwave and millimeter wave range in n-InP films, possessing the negative differential conductance phenomenon, is investigated theoretically. Both the amplified signal and the generation of harmonics of the input signal are demonstrated, which are due to non-linear effect of the negative differential resistance. It is possible to observe an amplification of the space charge waves in n-InP films of submicron thicknesses at essentially higher frequencies f <70 GHz, when compared with n-GaAs films f < 44 GHz. The increment observed in the gain is due to the larger dynamic range in n-InP than in n-GaAs films.

A compliant mechanism for inspecting extremely confined spaces

Science.gov (United States)

Mascareñas, David; Moreu, Fernando; Cantu, Precious; Shields, Daniel; Wadden, Jack; El Hadedy, Mohamed; Farrar, Charles

2017-11-01

We present a novel, compliant mechanism that provides the capability to navigate extremely confined spaces for the purpose of infrastructure inspection. Extremely confined spaces are commonly encountered during infrastructure inspection. Examples of such spaces can include pipes, conduits, and ventilation ducts. Often these infrastructure features go uninspected simply because there is no viable way to access their interior. In addition, it is not uncommon for extremely confined spaces to possess a maze-like architecture that must be selectively navigated in order to properly perform an inspection. Efforts by the imaging sensor community have resulted in the development of imaging sensors on the millimeter length scale. Due to their compact size, they are able to inspect many extremely confined spaces of interest, however, the means to deliver these sensors to the proper location to obtain the desired images are lacking. To address this problem, we draw inspiration from the field of endoscopic surgery. Specifically we consider the work that has already been done to create long flexible needles that are capable of being steered through the human body. These devices are typically referred to as ‘steerable needles.’ Steerable needle technology is not directly applicable to the problem of navigating maze-like arrangements of extremely confined spaces, but it does provide guidance on how this problem should be approached. Specifically, the super-elastic nitinol tubing material that allows steerable needles to operate is also appropriate for the problem of navigating maze-like arrangements of extremely confined spaces. Furthermore, the portion of the mechanism that enters the extremely confined space is completely mechanical in nature. The mechanical nature of the device is an advantage when the extremely confined space features environmental hazards such as radiation that could degrade an electromechanically operated mechanism. Here, we present a compliant mechanism

Space Physiology and Operational Space Medicine

Science.gov (United States)

Scheuring, Richard A.

2009-01-01

The objectives of this slide presentation are to teach a level of familiarity with: the effects of short and long duration space flight on the human body, the major medical concerns regarding future long duration missions, the environmental issues that have potential medical impact on the crew, the role and capabilities of the Space Medicine Flight Surgeon and the environmental impacts experienced by the Apollo crews. The main physiological effects of space flight on the human body reviewed in this presentation are: space motion sickness (SMS), neurovestibular, cardiovascular, musculoskeletal, immune/hematopoietic system and behavioral/psycho-social. Some countermeasures are discussed to these effects.

A History of Space Shuttle Main Engine (SSME) Redline Limits Management

Science.gov (United States)

Arnold, Thomas M.

2011-01-01

The Space Shuttle Main Engine (SSME) has several "redlines", which are operational limits designated to preclude a catastrophic shutdown of the SSME. The Space Shuttle Orbiter utilizes a combination of hardware and software to enable or disable the automated redline shutdown capability. The Space Shuttle is launched with the automated SSME redline limits enabled, but there are many scenarios which may result in the manual disabling of the software by the onboard crew. The operational philosophy for manually enabling and disabling the redline limits software has evolved continuously throughout the history of the Space Shuttle Program, due to events such as SSME hardware changes and updates to Space Shuttle contingency abort software. In this paper, the evolution of SSME redline limits management will be fully reviewed, including the operational scenarios which call for manual intervention, and the events that triggered changes to the philosophy. Following this review, improvements to the management of redline limits for future spacecraft will be proposed.

'V' shaped predens space

International Nuclear Information System (INIS)

Bohrer, S.P.; Klein, A.; Martin, W.

1985-01-01

''V'' shaped widening of the predens space (PDS) in flexion can be a worrisome finding in traume patients, possibly representing injury to the transverse ligament. These patients may also show widening of the C-1/C-2 interspinous distance. We think this appearance is usually due to increased flexion mobility at the atlantoaxial level with developmental elongation or laxity of the cranial end of the transverse ligament and/or the posterior ligamentous complex. Tearing of only the cranial end of the transverse ligament must be extremely rare, if it occurs at all; there is no reported proven case. Tearing of only posterior ligaments seems possible and should be evaluated clinically. (orig.)

Space Commercialization

Science.gov (United States)

Martin, Gary L.

2011-01-01

A robust and competitive commercial space sector is vital to continued progress in space. The United States is committed to encouraging and facilitating the growth of a U.S. commercial space sector that supports U.S. needs, is globally competitive, and advances U.S. leadership in the generation of new markets and innovation-driven entrepreneurship. Energize competitive domestic industries to participate in global markets and advance the development of: satellite manufacturing; satellite-based services; space launch; terrestrial applications; and increased entrepreneurship. Purchase and use commercial space capabilities and services to the maximum practical extent Actively explore the use of inventive, nontraditional arrangements for acquiring commercial space goods and services to meet United States Government requirements, including measures such as public-private partnerships, . Refrain from conducting United States Government space activities that preclude, discourage, or compete with U.S. commercial space activities. Pursue potential opportunities for transferring routine, operational space functions to the commercial space sector where beneficial and cost-effective.

Space Colonization Using Space-Elevators from Phobos

Science.gov (United States)

Weinstein, Leonard M.

2003-01-01

A novel approach is examined for creating an industrial civilization beyond Earth. The approach would take advantage of the unique configuration of Mars and its moon Phobos to make a transportation system capable of raising mass from the surface of Mars to space at a low cost. Mars would be used as the primary location for support personnel and infrastructure. Phobos would be used as a source of raw materials for space-based activity, and as an anchor for tethered carbon-nanotube-based space-elevators. One space-elevator would terminate at the upper edge of Mars' atmosphere. Small craft would be launched from Mars' surface to rendezvous with the moving elevator tip and their payloads detached and raised with solar powered loop elevators to Phobos. Another space-elevator would be extended outward from Phobos to launch craft toward the Earth/Moon system or the asteroid belt. The outward tip would also be used to catch arriving craft. This approach would allow Mars to be colonized, and allow transportation of people and supplies from Mars to support the space industry. In addition, large quantities of material obtained from Phobos could be used to construct space habitats and also supply propellant and material for space industry in the Earth/Moon system as well as around Mars.

Analogies between Kruskal space and de Sitter space

International Nuclear Information System (INIS)

Rindler, W.

1986-01-01

Kruskal space is the analytical completion of Schwarzschild space and it consists of two outside and two inside Schwarzchild regions. Under suppression of the two angular coordinates, this space is usually diagrammed in terms of the Kruskal coordinates, μ,upsilon, much like Minkowski space is in terms of x, y. In particular, radial light paths correspond to +- 45 0 lines, the hyperbolas of μ/sup 2/ - upsilon/sup 2/ = a/sup 2/ represent uniformly accelerated particles (these being at rest in outer Schwarzschild space), and Lorentz transformations in μ, upsilon map the space into itself. Hermann Weyl first gave the analytic completion of de Sitter space as a hyper-hyperboloid μ/sub 1//sup 2/ + μ/sub 2//sup 2/ + μ/sub 3//sup 2/ + μ/sub 4//sup 2/ - upsilon/sup 2/ = a/sup 2/ in five-dimensional Minkowski space, which also contains two outside inside de Sitter regions. In a Weyl diagram, μ/sub 3/ and μ/sub 4/ are suppressed. There are many analogies: Lorentz transformations in μ/sub i/, upsilon map Weyl space into itself, the +- 45 0 generators are light paths, timelike plane hyperbolic sections are uniformly accelerated particles, and the horizon structure relative to each free worldline is analogous to the absolute horizon structure in Kruskal space

A reliability analysis tool for SpaceWire network

Science.gov (United States)

Zhou, Qiang; Zhu, Longjiang; Fei, Haidong; Wang, Xingyou

2017-04-01

A SpaceWire is a standard for on-board satellite networks as the basis for future data-handling architectures. It is becoming more and more popular in space applications due to its technical advantages, including reliability, low power and fault protection, etc. High reliability is the vital issue for spacecraft. Therefore, it is very important to analyze and improve the reliability performance of the SpaceWire network. This paper deals with the problem of reliability modeling and analysis with SpaceWire network. According to the function division of distributed network, a reliability analysis method based on a task is proposed, the reliability analysis of every task can lead to the system reliability matrix, the reliability result of the network system can be deduced by integrating these entire reliability indexes in the matrix. With the method, we develop a reliability analysis tool for SpaceWire Network based on VC, where the computation schemes for reliability matrix and the multi-path-task reliability are also implemented. By using this tool, we analyze several cases on typical architectures. And the analytic results indicate that redundancy architecture has better reliability performance than basic one. In practical, the dual redundancy scheme has been adopted for some key unit, to improve the reliability index of the system or task. Finally, this reliability analysis tool will has a directive influence on both task division and topology selection in the phase of SpaceWire network system design.

Self-dual phase space for (3 +1 )-dimensional lattice Yang-Mills theory

Science.gov (United States)

Riello, Aldo

2018-01-01

I propose a self-dual deformation of the classical phase space of lattice Yang-Mills theory, in which both the electric and magnetic fluxes take value in the compact gauge Lie group. A local construction of the deformed phase space requires the machinery of "quasi-Hamiltonian spaces" by Alekseev et al., which is reviewed here. The results is a full-fledged finite-dimensional and gauge-invariant phase space, the self-duality properties of which are largely enhanced in (3 +1 ) spacetime dimensions. This enhancement is due to a correspondence with the moduli space of an auxiliary noncommutative flat connection living on a Riemann surface defined from the lattice itself, which in turn equips the duality between electric and magnetic fluxes with a neat geometrical interpretation in terms of a Heegaard splitting of the space manifold. Finally, I discuss the consequences of the proposed deformation on the quantization of the phase space, its quantum gravitational interpretation, as well as its relevance for the construction of (3 +1 )-dimensional topological field theories with defects.

EMERGING CHALLENGES IN THE MANAGEMENT OF CONTEMPORARY PUBLIC SPACES IN URBAN NEIGHBOURHOODS

Directory of Open Access Journals (Sweden)

Rajjan Man Chitrakar

2017-03-01

Full Text Available The lack of management has led to the degrading quality of public space in modern cities around the globe. Contemporary public spaces are facing challenges in terms of maintaining them as a “social space” so that they are accessible and functional for the users. Using Kathmandu as a case study, this paper explores the challenges the contemporary public spaces within urban neighbourhoods are facing in their management. The study reveals that the regulation of use is a major concern of public space management in the new neighbourhoods of Kathmandu as evident in the limited accessibility and utility of public space, due to control and commercialisation. The use of public space has also been affected by the lack of regular maintenance. The root cause of these problems lies in weak urban governance at the neighbourhood level, which has led the local community-based organisations to take a role in neighbourhood management. These findings confirm that the management of public space is a critical issue of urban development with commonalities existing across geographical regions that demand adequate consideration from the stakeholders.

Space Ethics and Protection of the Space Environment

Science.gov (United States)

Williamson, Mark

2002-01-01

The construction of the International Space Station in low Earth orbit and the formulation of plans to search for life on Mars - one day by means of manned missions - indicate that mankind is intent on making the space environment part of its domain. Publicity surrounding space tourism, in-space `burials' and the sale of lunar `real estate' suggests that, some time in the 21st century, the space environment will become an extraterrestrial extension of our current business and domestic environment. This prompts the question of our collective attitude towards the space environment and the degree to which we should regulate its use and protect it for future generations. What, indeed, are the ethical considerations of space exploration and development? Ethics can be defined as "the philosophical study of the moral value of human conduct, and of the rules or principles that ought to govern it". More practically, it represents "an approved code of behaviour" adopted, for example, by a group or profession. If a set of ethics is to be developed for space, it is important that what we refer to as the `space community', or `space profession', is intimately involved. Indeed, if it is not, the profession risks having the job done for it, for example by politicians and members of the general public, who for their own reasons may wish to place restrictions on space development, or ban it altogether. The terrestrial nuclear power industry, for example, has already suffered this fate, while widespread ignorance of the subject has led to a moratorium on the use of RTGs in spacecraft. However, there is a danger in the discussion of ethics that consideration is confined to the philosophical aspects, thus excusing those involved from providing practical solutions to the problems that emerge. The fact that mankind has already affected, and arguably damaged, the space environment transports the discussion beyond the philosophical realm. This paper offers a pragmatic analysis of one

A general number-to-space mapping deficit in developmental dyscalculia.