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Sample records for orbital wall fracture

  1. Orbital Fracture: Significance of lateral wall

    PubMed Central

    Alsuhaibani, Adel H.

    2010-01-01

    The lateral orbital wall is the strongest among other orbital walls. However, it is commonly fractured in the setting of severe facial trauma. The fracture usually occurs at the sphenozygomatic suture line. In general, patients with lateral wall fractures are commonly young male who may present with mid facial swelling and some degree of deformity. In some cases, lateral orbital wall fracture may be associated with visual loss or change in mental status due to associated intracranial injury. Imaging studies with computed tomography is important in the proper diagnosis and planning of the surgical intervention. Management of intracranial or eye injuries should be undertaken on emergent basis. Thereafter, significantly displaced lateral wall fractures need to be repaired on timely basis. Proper realignment of the plane of the lateral orbital wall at the sphenozygomatic suture along with the other complex articulations of the zygomatic bone is necessary for proper functional and aesthetic outcome. PMID:23960875

  2. Direct oblique sagittal CT of orbital wall fractures

    SciTech Connect

    Ball, J.B. Jr.

    1987-03-01

    Direct oblique sagittal CT was used to evaluate trauma to 77 orbits. Sixty-seven orbital wall fractures with intact orbital rims (36 floor, 22 medial wall, nine roof) were identified in 47 orbits. Since persistent diplopia and/or enophthalmos may warrant surgical repair of orbital floor fractures, optimal imaging should include an evaluation of extraocular muscle status, the nature and amount of displaced orbital contents, and an accurate definition of fracture margins. For orbital floor fractures, a combination of the direct oblique sagittal and direct coronal projections optimally displayed all fracture margins, the fracture's relationship to the inferior orbital rim and medial orbital wall, and the amount of displacement into the maxillary sinus. Inferior rectus muscle status with 36 floor fractures was best seen on the direct oblique sagittal projection in 30 fractures (83.3%) and was equally well seen on sagittal and coronal projections in two fractures (5.5%). Floor fractures were missed on 100% of axial, 5.5% of sagittal, and 0% of coronal projections. Since the direct oblique sagittal projection complements the direct coronal projection in evaluating orbital floor fractures, it should not be performed alone. A technical approach to the CT evaluation or orbital wall fractures is presented.

  3. Orbital Wall Restoring Surgery for Inferomedial Blowout Fracture.

    PubMed

    Lim, Nam Kyu; Kang, Dong Hee; Oh, Sang Ah; Gu, Ja Hea

    2015-11-01

    Repairing a large inferomedial blowout fracture remains a challenge to orbital surgeon. The authors restored the fracture using combined transnasal and transorbital approaches using support of both paranasal sinuses. The authors compared surgical results of this novel method with those of the traditional procedure. Of 106 inferomedial blowout fracture patients who underwent surgical treatment between March 2007 and July 2013, 50 patients were selected in our study: 25 patients underwent the traditional procedure as controls, and the other 25 patients underwent orbital wall restoring surgery by our combined approach. Outcomes were evaluated in terms of the orbital volume ratio (OVR) and changes in Hertel scale. The OVR in the experimental group (7.19%) decreased more significantly than in the control group (2.71%) (P < 0.05). In conclusion, the orbit was restored more successfully following orbital wall restoring surgery with dual support than by using the traditional inferomedial blowout fracture procedure. PMID:26595000

  4. Orbital Wall Restoring Surgery in Pure Blowout Fractures

    PubMed Central

    Lim, Nam Kyu; Oh, Sang Ah; Gu, Ja Hea

    2014-01-01

    Background Restoring orbital volume in large blowout fractures is still a technically challenge to the orbital surgeon. In this study, we restored the orbital wall using the combination of transorbital and transnasal approach with additional supports from the paranasal sinuses, and we compared the surgical outcome to that of a conventional transorbital method. Methods A retrospective review of all patients with pure unilateral blowout fractures between March 2007 and March 2013 was conducted. 150 patients were classified into two groups according to the surgical method: conventional transorbital method (group A, 75 patients, control group), and the combination of transorbital and transnasal approach with additional supports from the paranasal sinuses (group B, 75 patients, experimental group). Each group was subdivided depending on fracture location: group I (inferior wall), group IM (inferomedial wall), and group M (medial wall). The surgical results were assessed by the Hertel scale and a comparison of preoperative and postoperative orbital volume ratio (OVR) values. Results In the volumetric analysis, the OVR decreased more by the experimental groups than each corresponding control groups (P<0.05). Upon ophthalmic examination, neither the differences among the groups in the perioperative Hertel scale nor the preoperative and postoperative Hertel scales were statistically significant (P>0.05). Conclusions Our surgical results suggest that orbital volume was more effectively restored by the combination of transorbital and transnasal approach with additional supports from the paranasal sinuses than the conventional method, regardless of the type of fracture. PMID:25396181

  5. Precaruncular approach for the reconstruction of medial orbital wall fractures.

    PubMed

    You, Hi-Jin; Kim, Deok-Woo; Dhong, Eun-Sang; Yoon, Eul-Sik

    2014-01-01

    To reconstruct medial orbital wall fractures with a clear, least dissection, an alternative method, precaruncular approach, has been performed. We reviewed 36 patients with medial blowout fractures treated with this technique. The incision was made between the caruncle and medial canthal skin at the mucocutaneous junction, and was continued along the conjunctival fornix superiorly and inferiorly. An extended conjunctival incision was carried for additional access to the orbit floor. The dissection continued medially and proceeded along the preseptal plane. The clinical results were assessed by postoperative computed tomographic scan and by reviewing postoperative complications. Postoperatively, computed tomographic scans demonstrated adequate reduction of soft tissues and correct positioning of the inserted implant without surgical complications. In most cases, the edema resolved within 24 to 48 hours after surgery. The precaruncular approach is a good option in reconstructing medial orbital wall fractures because it provides satisfactory exposure with superior cosmetic result. PMID:23241800

  6. Considerations for the Management of Medial Orbital Wall Blowout Fracture

    PubMed Central

    Park, Youngsoo; Chung, Kyu Jin

    2016-01-01

    Recently, diagnoses of and operations for medial orbital blowout fracture have increased because of the development of imaging technology. In this article, the authors review the literature, and overview the accumulated knowledge about the orbital anatomy, fracture mechanisms, surgical approaches, reconstruction materials, and surgical methods. In terms of surgical approaches, transcaruncular, transcutaneous, and transnasal endoscopic approaches are discussed. Reconstruction methods including onlay covering, inlay implantation, and repositioning methods are also discussed. Consideration and understanding of these should lead to more optimal outcomes. PMID:27218019

  7. Considerations for the Management of Medial Orbital Wall Blowout Fracture.

    PubMed

    Kim, Yong-Ha; Park, Youngsoo; Chung, Kyu Jin

    2016-05-01

    Recently, diagnoses of and operations for medial orbital blowout fracture have increased because of the development of imaging technology. In this article, the authors review the literature, and overview the accumulated knowledge about the orbital anatomy, fracture mechanisms, surgical approaches, reconstruction materials, and surgical methods. In terms of surgical approaches, transcaruncular, transcutaneous, and transnasal endoscopic approaches are discussed. Reconstruction methods including onlay covering, inlay implantation, and repositioning methods are also discussed. Consideration and understanding of these should lead to more optimal outcomes. PMID:27218019

  8. Transcaruncular Approach for Treatment of Medial Wall and Large Orbital Blowout Fractures.

    PubMed

    Nguyen, Dennis C; Shahzad, Farooq; Snyder-Warwick, Alison; Patel, Kamlesh B; Woo, Albert S

    2016-03-01

    We evaluate the safety and efficacy of the transcaruncular approach for reconstruction of medial orbital wall fractures and the combined transcaruncular-transconjunctival approach for reconstruction of large orbital defects involving the medial wall and floor. A retrospective review of the clinical and radiographic data of patients who underwent either a transcaruncular or a combined transcaruncular-transconjunctival approach by a single surgeon for orbital fractures between June 2007 and June 2013 was undertaken. Seven patients with isolated medial wall fractures underwent a transcaruncular approach, and nine patients with combined medial wall and floor fractures underwent a transcaruncular-transconjunctival approach with a lateral canthotomy. Reconstruction was performed using a porous polyethylene implant. All patients with isolated medial wall fractures presented with enophthalmos. In the combined medial wall and floor group, five out of eight patients had enophthalmos with two also demonstrating hypoglobus. The size of the medial wall defect on preoperative computed tomography (CT) scan ranged from 2.6 to 4.6 cm(2); the defect size of combined medial wall and floor fractures was 4.5 to 12.7 cm(2). Of the 11 patients in whom postoperative CT scans were obtained, all were noted to have acceptable placement of the implant. All patients had correction of enophthalmos and hypoglobus. One complication was noted, with a retrobulbar hematoma having developed 2 days postoperatively. The transcaruncular approach is a safe and effective method for reconstruction of medial orbital floor fractures. Even large fractures involving the orbital medial wall and floor can be adequately exposed and reconstructed with a combined transcaruncular-transconjunctival-lateral canthotomy approach. The level of evidence of this study is IV (case series with pre/posttest). PMID:26889348

  9. Endoscopic endonasal versus transfacial approach for blowout fractures of the medial orbital wall.

    PubMed

    Pagnoni, Mario; Giovannetti, Filippo; Amodeo, Giulia; Priore, Paolo; Iannetti, Giorgio

    2015-05-01

    In the last decades, the introduction of computed tomography has allowed an increase in the number of diagnosed fractures of the medial orbital wall. To repair medial wall fractures, many surgical techniques have been proposed (1), each one with its advantages and disadvantages. In this study, we compared endoscopic endonasal and transcutaneous reduction approaches in terms of surgery time and clinical outcome. Between 2001 and 2005, 81 patients with orbital wall fractures were treated at our department. Among these 81 patients, 24 (29.63%) were affected by a medial orbital fracture. Patients with fracture to both floor and medial walls underwent floor reduction by a transcutaneous subpalpebral approach (n = 9, 11.1%), whereas patients with isolated medial wall fracture underwent medial wall reduction by a transcutaneous subpalpebral approach using alloplastic implants (n = 8, 9.88%) or were treated by endoscopic approach (n = 5, 6.17%). After surgery, oculomotor function improved in all 22 patients. None of the patients had complications. Computed tomography revealed a well-consolidated site of fracture in both endoscopic endonasal and transcutaneous approaches. The average operating time for endoscopic endonasal and transfacial approach was 50 and 45 minutes, respectively. In this paper, the author proposed a results comparison between the endoscopic approach and the transcutaneous one. PMID:25974823

  10. A case of acquired Brown syndrome after surgical repair of a medial orbital wall fracture.

    PubMed

    Seo, Il-Hun; Rhim, Jay-Won; Suh, Young-Woo; Cho, Yoonae A

    2010-02-01

    A case of acquired Brown syndrome caused by surgical repair of medial orbital wall fracture is reported in the present paper. A 23-year-old man presented at the hospital with right periorbital trauma. Although the patient did not complain of any diplopia, the imaging study revealed a blow-out fracture of the medial orbital wall. Surgical repair with a calvarial bone autograft was performed at the department of plastic surgery. The patient was referred to the ophthalmologic department due to diplopia that newly developed after surgery. The prism cover test at distant fixation showed hypotropia of the right eye, which was 4 prism diopters (PD) in primary gaze, 20 PD in left gaze, while orthophoric in right gaze. Eye movement of the right eye was markedly limited on elevation in adduction with normal elevation in abduction with intorsion in the right eye present. Forced duction test of the right eye showed restricted elevation in adduction. Computerized tomography scan of the orbits showed the right superior oblique muscle was entrapped between the autografted bone fragment and posterior margin of the fracture. When repairing medial orbital wall fracture that causes Brown syndrome, surgeons should always be careful of entrapment of the superior oblique muscle if the implant is inserted without identifying the superior and posterior margin of the orbital fracture site. PMID:20157416

  11. Retrocaruncular Approach for the Repair of Medial Orbital Wall Fractures: An Anatomical and Clinical Study

    PubMed Central

    Shen, Yun-Dun; Paskowitz, Daniel; Merbs, Shannath L.; Grant, Michael P.

    2014-01-01

    The aim of this article is to investigate a retrocaruncular approach for repairing medial orbital wall fractures. A total of 10 fresh cadaver orbits were dissected to investigate a transconjunctival approach to the orbit posterior to the caruncle. Medical records of consecutive patients with medial orbital wall fractures repaired via a retrocaruncular incision at Wilmer Eye Institute over a 10-year period were retrospectively reviewed. The study was approved by the Johns Hopkins Medical Institution's Institutional Review Board. Feasibility of this approach was clearly demonstrated on all cadavers. Horner muscle was observed to be directly attached to the caruncle and remained undisturbed throughout the retrocaruncular approach. For each of the 174 patients reviewed, this approach allowed successful access to the fracture and proper implant placement. The origin of the inferior oblique muscle was divided in only 19 patients. Sutures were not used for conjunctival incision closure in any patient. For 120 patients who underwent acute repair, the percentage with enophthalmos (≥ 2 mm) decreased from 34% preoperatively to 4% postoperatively; extraocular motility deficit decreased from 41 to 11%. Postoperative complications included recurrence of the preexisting retrobulbar hemorrhage, conjunctival granuloma, and temporary torsional diplopia, each in one patient. The retrocaruncular transconjunctival incision is an effective and safe approach for repairing medial orbital wall fractures with minimal complications. The retrocaruncular incision offers advantages over dividing the caruncle because Horner muscle is left undisturbed, and the incision heals well without suturing. PMID:26000079

  12. Endoscopic orbital decompression of an isolated medial orbital wall fracture: a case report.

    PubMed

    Gultekin, Erdogan; Ciftci, Zafer; Develioglu, Omer N; Celik, Oner; Yener, Murat; Kulekci, Mehmet

    2011-12-01

    Motor vehicle and bicycle accidents are the most common causes of blunt head trauma. Other common etiologies are falls, physical violence, and sports accidents. Blunt trauma toward the superior orbital rim, lateral orbital rim, frontal region, and cranium may lead to intraorbital hematoma. A fracture following the blunt head trauma may form a one-way valve, which leads to orbital emphysema and a more pronounced increase in orbital pressure. Increased tissue pressure in an enclosed space will eventually lead to an inevitable decrease in tissue perfusion. It is important to treat the patient within the first 48 hours following the trauma, which is accepted as the "critical period." In this report we present a case involving a 42-year-old man who was admitted to our clinic with left periorbital pain, edema, proptosis, and blurred vision after experiencing physical violence. The medical history and physical examination findings, along with imaging studies and a description of the endoscopic orbital decompression procedure within the first 24 hours, are reported. PMID:22180121

  13. Fixation of fractured inferior orbital wall using fibrin glue in inferior blowout fracture surgery.

    PubMed

    Jo, Eun Jun; Yang, Ho Jik; Kim, Jong Hwan

    2015-01-01

    The objectives of surgical treatment for orbital fracture are to return soft tissue to its original position as well as reduce and fix the bone fragments properly. Reduction of the orbital bone through a subciliary or conjunctival incision and reduction using a urinary balloon catheter were simultaneously performed on 53 patients between 2010 and 2013. Fibrin glue was used to attach the reduced bone fragments. These patients had less than 2 cm(2) of bone defect and showed diplopia, eye movement limitation, and enophthalmos. Diplopia, eye movement limitation, and enophthalmos were each reduced to 3/32, 2/25, and 2/48, respectively. There were no adverse effects, such as infection or hematoma, and because implants were not used, there was no possibility of its extrusion or foreign body reaction. The operation time decreased compared with when using an implant, and the bone fragments remained in a fixed position even after removing the urinary balloon catheter. Therefore, the use of fibrin glue proved to be effective in orbital floor fractures. PMID:25565237

  14. Medpor Implant Fixation Using Fibrin Glue in the Treatment of Medial Orbital Wall Fracture.

    PubMed

    Kang, Nakheon; Song, Seung Han; Kyung, Hyunwoo; Oh, Sang-Ha

    2015-06-01

    The optimal treatment modalities are determined based on the symptoms and degree of the bone defects in patients with medial orbital wall blowout fracture. Most of the patients in this series underwent implant surgery. However, there are many patients whose implants were not fixed during surgery. Therefore, some patients who had implant migration occurred had been reported. We have therefore used methods for applying fibrin glue (Tisseel, Baxter Healthcare, Norfolk, United Kingdom) for the fixation of implant. Between 2007 and 2013, a total of 168 patients underwent porous polyethylene orbital implant (Medpor) surgery with the application of Tisseel. All the patients underwent surgical treatments via a transcaruncular approach, for which the Medpor was used. Postoperative complications include 6 cases of the limitation of extraoccular movement, 10 cases of diplopia, and 7 cases of enophthalmos. However, there were no specific complications caused by Tisseel. All the patients were satisfied with the treatment outcomes. In this study, we report the usefulness of Tisseel in the fixation of the medial orbital wall fracture using the Medpor implant with a review of literatures. PMID:26080196

  15. [Isolated medial orbital wall fracture and late fronto-ethmoidal mucocele].

    PubMed

    Iinuma, T; Hirota, Y; Kase, Y; Kuriyama, J; Yamane, M; Ichimura, K; Oyama, K

    1991-12-01

    Twenty-one cases of isolated medial orbital wall fractures were reported and CT findings by coronal planes were evaluated as to the effects of fractures upon the ethmoidal cells and nasal meati. Three coronal planes, which respectively contain such structures as Agger nasi, Pars membranacea and superior meatus, were selected for the study. The extent of fracture was evaluated by dividing the medial wall into three equal portions, i.e., superior, middle and inferior. The prolapsed volume was evaluated in three classes of occupying 1/3, 2/3 and 3/3 of the ethmoid. The presence of soft tissue density was recorded at the three surfaces, upper, medial and lower, around the prolapsed orbital content. The extent of the fracture was most often seen in such cases as involving all the three divisions in 41.3%. The prolapsed volume occupying 1/3 was seen in 28, 6%, and 2/3 in 23.8%. The presence of soft tissue density was seen in 38.1% of upper surface, in 36.5% of medial, and 11.1% of lower. Summarizing the total effects of the fractures, the coronal plane containing Pars membranacea was most severely damaged followed by the plane of the superior meatus. Two rare cases of fronto-ethmoidal mucoceles, caused by the traumas of 23 and 14 years before respectively, were also included and reported. The ophthalmological prognosis was favorable in 90.5% of cases by observations extending more than 6 months. Five cases were surgically treated including two cases of mucoceles.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:1779265

  16. Patient specific implants (PSI) in reconstruction of orbital floor and wall fractures.

    PubMed

    Gander, Thomas; Essig, Harald; Metzler, Philipp; Lindhorst, Daniel; Dubois, Leander; Rücker, Martin; Schumann, Paul

    2015-01-01

    Fractures of the orbital wall and floor can be challenging due to the demanding three-dimensional anatomy and limited intraoperative overview. Misfitting implants and inaccurate surgical technique may lead to visual disturbance and unaesthetic results. A new approach using individually manufactured titanium implants (KLS Martin, Group, Germany) for daily routine is presented in the current paper. Preoperative CT-scan data were processed in iPlan 3.0.5 (Brainlab, Feldkirchen, Germany) to generate a 3D-reconstruction of the affected orbit using the mirrored non-affected orbit as template and the extent of the patient specific implant (PSI) was outlined and three landmarks were positioned on the planned implant in order to allow easy control of the implant's position by intraoperative navigation. Superimposition allows the comparison of the postoperative result with the preoperative planning. Neither reoperation was indicated due to malposition of the implant and the ocular bulb nor visual impairments could be assessed. PSI allows precise reconstruction of orbital fractures by using a complete digital workflow and should be considered superior to manually bent titanium mesh implants. PMID:25465486

  17. Endoscopic transnasal approach and intraoperative navigation for the treatment of isolated blowout fractures of the medial orbital wall.

    PubMed

    Copelli, C; Manfuso, A; d'Ecclesia, A; Catanzaro, S; Cassano, L; Pederneschi, N; Tewfik Hanna, K; Cocchi, R

    2015-12-01

    The aim of this study is to describe the reduction of medial orbital wall fractures using a combination of two different techniques: the endoscopic reduction and the navigation aided reconstruction. The endoscopic approach avoids an external incision and allows the observation of the fracture site clearly. Navigation-aided reconstruction is essential to achieve precise and predictable results in orbital reconstruction. It consists in an ideal virtual reconstruction of the target area created using a mirroring tool, and superimposing and comparing the unaffected and the affected sides. This technique opens a broad spectrum of possible surgical approaches, especially in situations in which anatomical landmarks for precise positioning of bone fragments, or bone grafts, are missing. This study is the first to combine these two techniques. The study was carried out in seven patients who underwent endoscopic reduction of isolated blowout fractures of the medial orbital wall and navigation-aided reconstruction at the authors' institution. This pilot study clearly shows that a combination of the endoscopic reduction and the navigation-aided reconstruction provides functional results and great advantages in terms of anatomical preservation and postoperative morbidity. PMID:26548529

  18. A peculiar blow-out fracture of the inferior orbital wall complicated by extensive subcutaneous emphysema: A case report and review of the literature

    PubMed Central

    Rzymska-Grala, Iwona; Palczewski, Piotr; Błaż, Marcin; Zmorzyński, Michał; Gołębiowski, Marek; Wanyura, Hubert

    2012-01-01

    Summary Background: Blow-out fracture of the orbit is a common injury. However, not many cases are associated with massive subcutaneous emphysema. Even fewer cases are caused by minor trauma or are associated with barotrauma to the orbit due to sneezing, coughing, or vomiting. The authors present a case of blow-out fracture complicated by extensive subcutaneous and mediastinal emphysema that occurred without any obvious traumatic event. Case Report: A 43-year-old man presented to the Emergency Department with a painful right-sided exophthalmos that he had noticed in the morning immediately after waking up. The patient also complained of diplopia. Physical examination revealed exophthalmos and crepitations suggestive of subcutaneous emphysema. The eye movements, especially upward gaze, were impaired. CT showed blow-out fracture of the inferior orbital wall with a herniation of the orbital soft tissues into the maxillary sinus. There was an extensive subcutaneous emphysema in the head and neck going down to the mediastinum. The patient did not remember any significant trauma to the head that could explain the above mentioned findings. At surgery, an inferior orbital wall fracture with a bony defect of 3×2 centimeter was found and repaired. Conclusions: Blow-out fractures of the orbit are usually a result of a direct trauma caused by an object with a diameter exceeding the bony margins of the orbit. In 50% of cases, they are complicated by orbital emphysema and in 4% of cases by herniation of orbital soft tissues into paranasal sinuses. The occurrence of orbital emphysema without trauma is unusual. In some cases it seems to be related to barotrauma due to a rapid increase in pressure in the upper airways during sneezing, coughing, or vomiting, which very rarely leads to orbital wall fracture. Computed tomography is the most accurate method in detecting and assessing the extent of orbital wall fractures. PMID:22844312

  19. Two-Year Follow-up on the Use of Absorbable Mesh Plates in the Treatment of Medial Orbital Wall Fractures

    PubMed Central

    You, Jae-Pil; Kim, Deok-Woo; Jeon, Byung-Joon; Jeong, Seong-Ho; Han, Seung-Kyu; Kim, Woo-Kyung

    2013-01-01

    Background Absorbable materials offer many advantages in the reconstruction of orbital walls; however, the possibility of postoperative enophthalmos after complete absorption cannot be excluded. We evaluated the postoperative results of absorbable mesh plates used as onlay implanting on the medial orbital wall to determine whether they are suitable for medial orbital wall reconstruction. Methods The study included 20 patients with medial orbital wall fractures who were followed up for more than 2 years postoperatively. We used absorbable mesh plates in all of the patients. We measured the following: the changes in the expanded orbital volume by comparing the preoperative and postoperative computed tomography (CT) scans and the degree of clinical enophthalmos. Results There were no major complications associated with the use of absorbable materials such as infection, migration, or extrusion of mesh plates during the long-term follow-up. The orbital volumetric changes between the preoperative and postoperative CT scans were not statistically significant. However, the expanded orbital volume was not related to the degree of clinical enophthalmos. Conclusions The reconstructed orbital wall may provide supportive scar tissue to the orbital contents even after the absorbable materials have dissolved completely. Absorbable mesh plates could be another option for the reconstruction of the medial orbital wall. PMID:24286046

  20. Three-Dimensional Pre-Bent Titanium Implant for Concomitant Orbital Floor and Medial Wall Fractures in an East Asian Population

    PubMed Central

    Lee, Kyung Min; Park, Ji Ung; Kwon, Sung Tack; Kim, Suk Wha

    2014-01-01

    Background The objective of this article is to evaluate clinical outcomes of combined orbital floor and medial wall fracture repair using a three-dimensional pre-bent titanium implant in an East Asian population. Methods Clinical and radiologic data were analyzed for 11 patients with concomitant orbital floor and medial wall fractures. A combined transcaruncular and inferior fornix approach with lateral canthotomy was used for the exposure of fractures. An appropriate three-dimensional preformed titanium implant was selected and inserted according to the characteristics of a given defect. Results Follow-up time ranged from 2 to 6 months (median, 4.07 months). All patients had a successful treatment outcome without any complications. Clinically significant enophthalmos was not observed after treatment. Conclusions Three-dimensional pre-bent titanium implants are appropriate for use in the East Asian population, with a high success rate of anatomic restoration of the orbital volume and prevention of enophthalmos in combined orbital floor and medial wall fracture cases. PMID:25276638

  1. Biomaterials for orbital fractures repair

    PubMed Central

    Totir, M; Ciuluvica, R; Dinu, I; Careba, I; Gradinaru, S

    2014-01-01

    The unique and complex anatomy of the orbit requires significant contouring of the implants to restore the proper anatomy. Fractures of the orbital region have an incidence of 10-25% from total facial fractures and the most common age group was the third decade of life. The majority of cases require reconstruction of the orbital floor to support the globe position and restore the shape of the orbit. The reason for this is that the bony walls are comminuted and/or bone fragments are missing. Therefore, the reconstruction of missing bone is important rather than reducing bone fragments. This can be accomplished using various materials. There is hardly any anatomic region in the human body that is so controversial in terms of appropriate material used for fracture repair: nonresorbable versus resorbable, autogenous/allogenous/xenogenous versus alloplastic material, non-prebent versus preformed (anatomical) plates, standard versus custom-made plates, nonporous versus porous material, non-coated versus coated plates. Thus, the importance of material used for reconstruction becomes more challenging for the ophthalmologist and the oral and maxillofacial surgeon. PMID:27057250

  2. Biomaterials for orbital fractures repair

    PubMed Central

    Totir, M; Ciuluvica, R; Dinu, I; Careba, I; Gradinaru, S

    2015-01-01

    The unique and complex anatomy of the orbit requires significant contouring of the implants to restore the proper anatomy. Fractures of the orbital region have an incidence of 10-25% from the total facial fractures and the most common age group was the third decade of life. The majority of cases required reconstruction of the orbital floor to support the globe position and restore the shape of the orbit. The reason for this was that the bony walls were comminuted and/ or bone fragments were missing. Therefore, the reconstruction of the missing bone was important rather than reducing the bone fragments. This could be accomplished by using various materials. There is hardly any anatomic region in the human body that is so controversial in terms of appropriate material used for fracture repair: non resorbable versus resorbable, autogenous/ allogeneic/ xenogenous versus alloplastic material, non-prebent versus preformed (anatomical) plates, standard versus custom-made plates, nonporous versus porous material, non-coated versus coated plates. Thus, the importance of the material used for reconstruction becomes more challenging for the ophthalmologist and the oral and maxillofacial surgeon. PMID:25914737

  3. Combined Orbital Floor and Medial Wall Fractures Involving the Inferomedial Strut: Repair Technique and Case Series Using Preshaped Porous Polyethylene/Titanium Implants

    PubMed Central

    Cho, Raymond I.; Davies, Brett W.

    2013-01-01

    Background Combined orbital floor and medial wall fractures can be technically challenging to repair, particularly when the inferomedial strut is involved. A surgical repair technique is described utilizing a single preshaped porous polyethylene/titanium implant to span both defects. Methods Retrospective interventional case series. Results Fracture repair was performed on 17 orbits (16 patients) between October 2009 and February 2012. Subsequent surgical revision was required in three cases (18%). Visual acuity was stable or improved in all cases. Of 7 patients with preoperative diplopia, 5 improved and 2 remained stable postoperatively, and there were no cases of new or worsened diplopia following surgery. Postoperative asymmetry in Hertel exophthalmometry averaged 1.0 mm (range 0 to 2 mm). Preoperatively, average orbital volume was 122.7% compared with control (range 109 to 147%, standard deviation [SD] 9.6), which improved to 100.3% postoperatively (range 92 to 110%, SD 5.7). The average decrease in orbital volume was 22.5% (range 10 to 54%, SD 11.4, p < 0.001). Conclusions With careful preoperative planning and meticulous surgical technique, combined orbital floor and medial wall fractures involving the inferomedial strut can be successfully repaired with a preshaped porous polyethylene/titanium implant through a transconjunctival/transcaruncular approach with inferior oblique disinsertion. PMID:24436754

  4. Blow-in fracture of the orbit.

    PubMed

    Hwang, Kun; Kim, Han Joon; Lee, Hong Sik

    2013-01-01

    We report 2 patients with blow-in fractures of the orbital floor caused by different mechanisms. In a 17-year-old boy, a sudden impact was given to the anterior maxillary wall and caused a depression fracture of a maxilla, yet the infraorbital rim remained intact. We think fragments of the orbital floor were forced into the orbit by a sudden increase in pressure in the maxillary sinus in this patient. In a 51-year-old man, the impact of a force was on the laterosuperior part of the zygoma, which pushed the zygoma medially. These 2 cases represent 2 different mechanisms of blow-in fractures of the orbital floor. PMID:24036789

  5. Safety of Silastic Sheet for Orbital Wall Reconstruction

    PubMed Central

    Moon, Seong June; Park, Bo Young; Kang, So Ra

    2014-01-01

    Background Many implants are being used for the reconstruction of orbital wall fractures. The effect of the choice of implant for the reconstruction of an orbital wall fracture on the surgical outcome is under debate. The purpose of this article is to compare the outcomes of orbital wall reconstruction of small orbital wall fractures on the basis of the implants used. Methods The authors conducted a retrospective study using electronic databases. Between March 2001 and December 2012, 461 patients with orbital wall fractures were included in this study. Among them, 431 patients in whom the fracture size was less than 300 mm2 were analyzed. The fracture size was calculated using computed tomography scans of the orbit in the sagittal and coronal images. Cases in which the fracture size was less than 300 mm2 were included in this study. Results One hundred and twenty-nine patients were treated with silastic sheets; 238 patients were treated with titanium meshes; and absorbable meshes were used in the case of 64 patients. Overall, 13 patients required revision, and the revision rate was 3.0%. The revision rate of the silastic sheet group was 5.4%. In the multivariable analysis, the revision rate of the group reconstructed with silastic sheets was highly statistically significant (P=0.043, odds ratio=3.65). However, other factors such as age, sex, fracture type, and fracture size were not significant. Conclusions Reconstruction of orbital wall fractures with silastic sheets may cause more complications than that with other materials such as titanium meshes and absorbable meshes. PMID:25075358

  6. Application of endoscopic techniques in orbital blowout fractures.

    PubMed

    Zhang, Shu; Li, Yinwei; Fan, Xianqun

    2013-09-01

    Minimally invasive surgical techniques, particularly endoscopic techniques, have revolutionized otolaryngeal surgery. Endoscopic techniques have been gradually applied in orbital surgery through the sinus inferomedial to the orbit and the orbital subperiosteal space. Endoscopic techniques help surgeons observe fractures and soft tissue of the posterior orbit to precisely place implants and protect vital structures through accurate, safe, and minimally invasive approaches. We reviewed the development of endoscopic techniques, the composition of endoscopic systems for orbital surgery, and the problems and developmental prospects of endoscopic techniques for simple orbital wall fracture repair. PMID:23794028

  7. Spontaneously reduced isolated orbital roof fracture.

    PubMed

    Itinteang, Tinte; Lambe, Gerald Francis; MacKinnon, Craig; Agir, Hakan

    2012-07-01

    We report a case of a spontaneously reduced isolated orbital roof blow-in fracture with resolution of associated diplopia and blepharoptosis highlighting the need for a low threshold for reimaging this cohort of facial fracture patients. PMID:22801127

  8. Nontraumatic orbital floor fracture after nose blowing.

    PubMed

    Sandhu, Ranjit S; Shah, Akash D

    2016-03-01

    A 40-year-old woman with no history of trauma or prior surgery presented to the emergency department with headache and left eye pain after nose blowing. Noncontrast maxillofacial computed tomography examination revealed an orbital floor fracture that ultimately required surgical repair. There are nontraumatic causes of orbital blowout fractures, and imaging should be obtained irrespective of trauma history. PMID:26973725

  9. Nontraumatic orbital floor fracture after nose blowing

    PubMed Central

    Sandhu, Ranjit S.; Shah, Akash D.

    2016-01-01

    A 40-year-old woman with no history of trauma or prior surgery presented to the emergency department with headache and left eye pain after nose blowing. Noncontrast maxillofacial computed tomography examination revealed an orbital floor fracture that ultimately required surgical repair. There are nontraumatic causes of orbital blowout fractures, and imaging should be obtained irrespective of trauma history. PMID:26973725

  10. Orbital fracture deterioration after scuba diving.

    PubMed

    Nakatani, Hiroko; Yoshioka, Nobutaka

    2009-07-01

    Sinus barotrauma is a common disease in divers. However, it is not familiar to maxillofacial surgeon. We presented orbital fracture deterioration by sinus barotrauma in scuba diving and a review of literatures. We also discussed the clinical features, the prevention, and the possible mechanism of orbital fracture deterioration after scuba diving. PMID:19625851

  11. A clinical analysis of bilateral orbital fracture.

    PubMed

    Roh, Joon Ho; Jung, Jee Woong; Chi, Mijung

    2014-03-01

    Although bilateral orbital fracture can cause serious eyeball and facial skeletal problems, few reports have been issued on the topic. We analyzed the clinical features of bilateral orbital fracture by reviewing the medical records of 147 patients and compared bilateral and unilateral fractures by reviewing the literature.Bilateral orbital fracture was most common in men aged between 50 and 59 years. A traffic accident was the leading cause of trauma, and average time between trauma and surgery was 12.2 days. Bilateral medial fracture accompanied by nasal fracture accounted for the overwhelming majority, and impure blowout fracture in at least 1 eye occurred in 69.4% of the 147 patients. Associated ocular injuries seemed to be similar for bilateral and unilateral fracture. Thirty-five patients (23.8%) had other multiple traumas affecting other than the eyes, and this significantly increased the need for surgery (P < 0.05). Of the 48 patients who underwent surgery, including 4 cases of bilateral surgery, 21 patients who had ocular motility restriction with central diplopia within 30 degrees almost completely recovered. No significant relation between the timing of surgery and improvement was found. Although unilateral surgery was performed in most cases, facial asymmetry related to enophthalmos was unclear at 6 months postoperatively.In summary, bilateral orbital fracture was found to be clinically distinguishable from unilateral fracture in several aspects. We hope these findings provide a reference guide to the approach and management of bilateral orbital fracture. PMID:24514894

  12. Orbital fractures in children: a review of outcomes.

    PubMed

    Gerber, Barbara; Kiwanuka, Paul; Dhariwal, Daljit

    2013-12-01

    The third most common facial fractures in children are fractures of the orbit, and the medial wall and floor are the commonest sites affected. The aetiology, clinical presentation, and timing of operation all differ from those of adults. If there are few or no clinical signs, but oculocardiac reflex is present, it is highly suggestive of trapdoor injury. This retrospective study includes all consecutive children (younger than 18 years) referred with confirmed fractures of the orbital floor over a 5-year period (2005-2010). A total of 24 patients were identified with a mean age of 13.5 years, and most injuries were secondary to falls. Isolated injury to the orbital floor occurred in 14 (58%); the rest involved other fractures of the orbital wall or face, or both. There were 11 trapdoor fractures (46%), and 9 open blow-out fractures (38%). Overall, nausea and vomiting occurred in 13 patients (54%); 8 of these had trapdoor fractures. Most patients had operations (22, 92%), and the mean time to operation was 4 days. Complications increased with delays to theatre. Those operated on within 1 day had fewer complications than those who had operations after 3 days. Postoperatively, diplopia (n=6/11) and restricted eye movement (n=3/11) were associated with trapdoor injury, while enophthalmos (n=1/9) and paraesthesia (n=3/9) were related to open blow-out fractures. To reduce compromised outcomes, prompt operation is warranted in all children with fractures of the orbital floor regardless of the configuration. PMID:23915493

  13. Surgical treatment of orbital floor fractures.

    PubMed

    Rankow, R M; Mignogna, F V

    1975-01-01

    Ninety patients with orbital floor fractures were treated by the Otolaryngology Service of the Columbia-Presbyterian Medical Center. Of these 90 patients, 58 were classified as coexisting and 32 as isolated. All fractures with clinical symptoms and demonstrable x-ray evidence should be explored. Despite negative findings by routine techniques, laminography may confirm fractures in all clinically suspicious cases. In this series, 100% of the patients explored had definitive fractures. A direct infraorbital approach adequately exposes the floor of the orbit. An effective and cosmetic subtarsal incision was utilized. Implants were employed when the floor could not be anatomically reapproximated or the periorbita was destroyed. PMID:1119982

  14. Natural course of orbital roof fractures.

    PubMed

    Stam, Liselotte H M; Wolvius, Eppo B; Schubert, Warren; Koudstaal, Maarten J

    2014-12-01

    The natural course of several isolated and nonisolated orbital roof fractures is reported, by showing four cases in which a "wait and see" policy was followed. All four cases showed spontaneous repositioning and stabilizing of the fracture within less than a year. This might be explained by the equilibrium between the intraorbital and intracranial pressures. PMID:25383150

  15. Management of complex orbital fractures.

    PubMed

    Bhatti, N; Kanzaria, A; Huxham-Owen, N; Bridle, C; Holmes, S

    2016-09-01

    The treatment of orbital injuries has evolved considerably over the last two decades. We describe strategies involved in the emergency management of orbital injuries, the use of imaging, preformed and customised materials for reconstruction, and endoscopic techniques. PMID:27268464

  16. Combined Orbital Fractures: Surgical Strategy of Sequential Repair

    PubMed Central

    Hur, Su Won; Kim, Sung Eun; Chung, Kyu Jin; Lee, Jun Ho; Kim, Tae Gon

    2015-01-01

    Background Reconstruction of combined orbital floor and medial wall fractures with a comminuted inferomedial strut (IMS) is challenging and requires careful practice. We present our surgical strategy and postoperative outcomes. Methods We divided 74 patients who underwent the reconstruction of the orbital floor and medial wall concomitantly into a comminuted IMS group (41 patients) and non-comminuted IMS group (33 patients). In the comminuted IMS group, we first reconstructed the floor stably and then the medial wall by using separate implant pieces. In the non-comminuted IMS group, we reconstructed the floor and the medial wall with a single large implant. Results In the follow-up of 6 to 65 months, most patients with diplopia improved in the first-week except one, who eventually improved at 1 year. All patients with an EOM limitation improved during the first month of follow-up. Enophthalmos (displacement, 2 mm) was observed in two patients. The orbit volume measured on the CT scans was statistically significantly restored in both groups. No complications related to the surgery were observed. Conclusions We recommend the reconstruction of orbit walls in the comminuted IMS group by using the following surgical strategy: usage of multiple pieces of rigid implants instead of one large implant, sequential repair first of the floor and then of the medial wall, and a focus on the reconstruction of key areas. Our strategy of step-by-step reconstruction has the benefits of easy repair, less surgical trauma, and minimal stress to the surgeon. PMID:26217562

  17. Reconstruction using 'triangular approximation' of bone grafts for orbital blowout fractures.

    PubMed

    Saiga, Atsuomi; Mitsukawa, Nobuyuki; Yamaji, Yoshihisa

    2015-10-01

    There are many orbital wall reconstruction materials that can be used in surgery for orbital blowout fractures. We consider autogenous bone grafts to have the best overall characteristics among these materials and use thinned, inner cortical tables of the ilium. A bone bender is normally used to shape the inner iliac table to match the orbital shape. Since orbital walls curve three-dimensionally, processing of bone grafts is not easy and often requires much time and effort. We applied a triangular approximation method to the processing of bone grafts. Triangular approximation is a concept used in computer graphics for polygon processing. In this method, the shape of an object is represented as combinations of polygons, mainly triangles. In this study, the inner iliac table was used as a bone graft, and cuts or scores were made to create triangular sections. These triangular sections were designed three-dimensionally so that the shape of the resulting graft approximated to the three-dimensional orbital shape. This method was used in 12 patients with orbital blowout fractures, which included orbital floor fractures, medial wall fractures, and combined inferior and medial wall fractures. In all patients, bone grafts conformed to the orbital shape and good results were obtained. This simple method uses a reasonable and easy-to-understand approach and is useful in the treatment of bone defects in orbital blowout fractures when using a hard graft material. PMID:26297418

  18. An anomalous case of an indirect orbital floor fracture.

    PubMed

    Nicolotti, Matteo; Poglio, Giuseppe; Grivetto, Fabrizio; Benech, Arnaldo

    2014-09-01

    Fractures of the orbital floor are common in facial trauma. Those that comprise only the orbital floor are called indirect fractures or pure internal orbital floor fractures. We present the case of an indirect fracture of the orbital floor after direct trauma to the back of the head caused by a bicycle accident. To the best of our knowledge this is the first time that this mechanism for such a fracture has been reported. PMID:24742591

  19. Mucocele After Orbital Fracture Repair Masquerading as Optic Neuritis.

    PubMed

    Park, Jongyeop; Kim, Jinhyun; Choi, Jinsu; Kim, Hochang

    2016-06-01

    The authors report a patient of mucocele formation after orbital wall fracture repair masquerading as optic neuritis.A 38-year-old man with a history of medial orbital wall fracture repair with an alloplastic implant 10 years previously, presented with left visual disturbance and mild ocular pain with movement of the left eye of 3-day duration, and a relative afferent papillary defect in his left eye. He reported having cold symptoms 2 weeks before presentation. His symptoms were typical of retrobulbar optic neuritis. Under suspicion of optic neuritis, computed tomography and magnetic resonance imaging were performed and revealed a large cyst in the sphenoid sinus and ethmoid sinus, just behind the alloplastic implant, that was compressing the medial rectus muscle and optic nerve of the left eye. The patient underwent endoscopic marsupialization of the cyst. Subsequent histologic examinations revealed a cyst lined with ciliated pseudostratified columnar epithelium. The patient had an uncomplicated postoperative course and the visual disturbance resolved. For patients who present solely with optic neuropathy after orbital fracture repair, it is important to be vigilant of potentially rare cause, mucocele formation. PMID:27171955

  20. Management of orbital fractures: challenges and solutions.

    PubMed

    Boyette, Jennings R; Pemberton, John D; Bonilla-Velez, Juliana

    2015-01-01

    Many specialists encounter and treat orbital fractures. The management of these fractures is often challenging due to the impact that they can have on vision. Acute treatment involves a thorough clinical examination and management of concomitant ocular injuries. The clinical and radiographic findings for each individual patient must then be analyzed for the need for surgical intervention. Deformity and vision impairment can occur from these injuries, and while surgery is intended to prevent these problems, it can also create them. Therefore, surgical approach and implant selection should be carefully considered. Accurate anatomic reconstruction requires complete assessment of fracture margins and proper implant contouring and positioning. The implementation of new technologies for implant shaping and intraoperative assessment of reconstruction will hopefully lead to improved patient outcomes. PMID:26604678

  1. Management of orbital fractures: challenges and solutions

    PubMed Central

    Boyette, Jennings R; Pemberton, John D; Bonilla-Velez, Juliana

    2015-01-01

    Many specialists encounter and treat orbital fractures. The management of these fractures is often challenging due to the impact that they can have on vision. Acute treatment involves a thorough clinical examination and management of concomitant ocular injuries. The clinical and radiographic findings for each individual patient must then be analyzed for the need for surgical intervention. Deformity and vision impairment can occur from these injuries, and while surgery is intended to prevent these problems, it can also create them. Therefore, surgical approach and implant selection should be carefully considered. Accurate anatomic reconstruction requires complete assessment of fracture margins and proper implant contouring and positioning. The implementation of new technologies for implant shaping and intraoperative assessment of reconstruction will hopefully lead to improved patient outcomes. PMID:26604678

  2. Orbital fractures due to domestic violence: an epidemiologic study.

    PubMed

    Goldberg, Stuart H.; McRill, Connie M.; Bruno, Christopher R.; Ten Have, Tom; Lehman, Erik

    2000-09-01

    Domestic violence is an important cause of orbital fractures in women. Physicians who treat patients with orbital fractures may not suspect this mechanism of injury. The purpose of this study was to assess the association between domestic violence and orbital fractures. A medical center-based case-control study with matching on age and site of admission was done. Medical center databases were searched using ICD-9 codes to identify all cases of orbital fractures encountered during a three-year period. Medical records of female patients age 13 and older were reviewed along with those of age, gender and site of admission matched controls. A stratified exact test was employed to test the association between domestic violence and orbital fracture. Among 41 adult female cases with orbital fractures treated at our medical center, three (7.3%) reported domestic violence compared to zero among the matched controls (p = 0.037). We believe that domestic violence may be under-reported in both orbital fracture cases and controls. This may result in an underestimate of the orbital fracture versus domestic violence association. Domestic violence is a serious women's health and societal problem. Domestic violence may have a variety of presentations, including illnesses and injuries. Orbital fracture is an identifiable manifestation of domestic violence. Domestic violence is more likely to be detected in adult female hospital patients with orbital fracture than in matched controls with any other diagnosis. Physicians who treat patients with orbital fractures should be familiar with this mechanism of injury. PMID:12045943

  3. Pure orbital blowout fractures reconstructed with autogenous bone grafts: functional and aesthetic outcomes.

    PubMed

    Kronig, S A J; van der Mooren, R J G; Strabbing, E M; Stam, L H M; Tan, J A S L; de Jongh, E; van der Wal, K G H; Paridaens, D; Koudstaal, M J

    2016-04-01

    The purpose of this study was to investigate the ophthalmic clinical findings following surgical reconstruction with autogenous bone grafts of pure blowout fractures. A retrospective review of 211 patients who underwent surgical repair of an orbital fracture between October 1996 and December 2013 was performed. Following data analysis, 60 patients who were followed up over a period of 1 year were included. A solitary floor fracture was present in 38 patients and a floor and a medial wall fracture in 22 patients. Comparing preoperative findings between these two groups, preoperative diplopia and enophthalmos were almost twice as frequent in the group with additional medial wall fractures: diplopia 8% and 14% and enophthalmos 18% and 55%, respectively. One year following surgery there was no diplopia present in either group. In the solitary floor fracture group, 3% still had enophthalmos. It can be concluded that at 1 year following the repair of pure orbital floor fractures using autogenous bone, good functional and aesthetic results can be obtained. In the group with both floor and medial wall fractures, no enophthalmos was found when both walls were reconstructed. When the medial wall was left unoperated, 29% of patients still suffered from enophthalmos after 1 year. PMID:26711249

  4. Evaluation of the lateral orbital approach in management of zygomatic bone fractures

    PubMed Central

    Thangavelu, K; Ganesh, N Sayee; Kumar, J Arun; Sabitha, S; Nikil

    2013-01-01

    Zygomatic maxillary fractures, also known as tripod fractures, are usually the result of a direct blow to the body of the zygoma. Tripod fracture consists of (a) zygomatic arch fracture, (b) fracture of the lateral orbital wall, and (c) fracture of the inferior orbital floor. The purpose of this study is to evaluate the functional and esthetic outcome following this lateral orbital approach in the management of zygoma fracture. This study was carried out in VMS Dental College, Salem, and in a private hospital. This study was based on the experience gained from a retrospective study of the 30 lateral orbital approaches that were used in 30 patients with fractures of the zygomatic complex, which were conducted for a period of 8 years between January 2003 and January 2011. In the retrospective study, all the 30 patients were able to open the mouth completely; eyeball movements were normal; esthetically, all patients appeared normal. There were no sinusitis or visual problems in any of the studied patients. We conclude that the lateral orbital approach is an ideal option in reduction and treatment of zygomatic bone and arch fractures. PMID:23633846

  5. Delayed Superior Orbital Fissure Syndrome After Reconstruction of Blowout Fracture.

    PubMed

    Kim, Young Joon; Choi, Woong Kyu

    2016-01-01

    The superior orbital fissure syndrome (SOFS) has been known to be a condition caused by impairment of the nerves that cross the superior orbital fissure. Traumatic SOFS is an uncommon complication which occurs usually within 48 hours after a facial injury. A 25-year-old male sustained facial trauma following an altercation. Clinical findings on presentation included swelling, ecchymosis, hyphema, subretinal hemorrhage, and mild extraocular movement limitation upon lateral gaze on his right eyelids. Facial computed tomography scan confirmed fractures of the medial walls of the right orbit and herniation of orbital soft tissue without the incarceration of medial rectus muscle. Ten days after the trauma, the operation was performed. On postoperative day 16, the patient showed ptosis of the right upper eyelid with a fixed pupil, and there was a hypoesthesia over the distribution of the right supraorbital and supratrochlear nerves. The authors diagnosed as a delayed SOFS and prescribed 4 mg of methylprednisolone q.i.d. for 30 days. After steroid therapy, extraocular movement limitations improved progressively. After 8 months, movement was completely restored. The authors experienced delayed SOFS on posttrauma day 27, and it was treated by steroid therapy. Surgical intervention is required when there is an evident etiology such as underlying hematoma or plate migration. If the reason is not clear like our case, steroid therapy can be considered as one of the options. Particularly, the authors should give special attention to the patient who has congenitally narrow superior orbital fissure, like Fujiwara et al suggested. PMID:26674904

  6. The Frequency of Decreased Visual Acuity in Orbital Fractures.

    PubMed

    Kim, Yeon Soo; Kim, Joo Ho; Hwang, Kun

    2015-07-01

    The aim of this systematic review is to summarize and evaluate the effect of orbital fractures (blowout fractures and nonblowout fractures) on visual acuity. In PubMed search and Scopus search, the terms "orbital fracture OR maxillofacial injury OR facial trauma OR craniofacial fracture," and "visual acuity OR functional outcome OR visual outcome OR improving document of visual acuity OR blindness OR optic nerve neuropathy" were used, which resulted in 1634 and 1152 papers, respectively. Of the 2226 titles excluding 560 duplicated titles, 227 abstracts were reviewed. Of the 227 abstracts reviewed, the authors found 56 potentially relevant full-text articles, of which 5 studies met our inclusion criteria. The odds ratio and 95% confidence intervals from each study were abstracted. The statistical analysis was performed with review manager (The Nordic Cochrane Centre). A summary of 5 studies affirmed that 43 patients among 532 orbital fractures (8.1%) had decreased visual acuity. Twelve patients among 159 blowout fractures (7.5%) had decreased visual acuity. Thirty-one patients among 373 orbital fractures other than pure blowout fractures (8.3%) had decreased visual acuity. In orbital fractures other than pure blowout fractures, the frequency of decreased visual acuity was higher than pure blowout fractures (n = 532, odds ratio, 2.23, 95% confidence interval = 1.06-4.70). Surgeons should acknowledge this with patients before surgery. PMID:26114513

  7. Mechanisms of orbital floor fractures: a clinical, experimental, and theoretical study.

    PubMed Central

    Bullock, J D; Warwar, R E; Ballal, D R; Ballal, R D

    1999-01-01

    PURPOSE: The purpose of this study was to investigate the two accepted mechanisms of the orbital blow-out fracture (the hydraulic and the buckling theories) from a clinical, experimental, and theoretical standpoint. METHODS: Clinical cases in which blow-out fractures resulted from both a pure hydraulic mechanism and a pure buckling mechanism are presented. Twenty-one intact orbital floors were obtained from human cadavers. A metal rod was dropped, experimentally, onto each specimen until a fracture was produced, and the energy required in each instance was calculated. A biomathematical model of the human bony orbit, depicted as a thin-walled truncated conical shell, was devised. Two previously published (by the National Aeronautics Space Administration) theoretical structural engineering formulas for the fracture of thin-walled truncated conical shells were used to predict the energy required to fracture the bone of the orbital floor via the hydraulic and buckling mechanisms. RESULTS: Experimentally, the mean energy required to fracture the bone of the human cadaver orbital floor directly was 78 millijoules (mj) (range, 29-127 mj). Using the engineering formula for the hydraulic theory, the predicted theoretical energy is 71 mj (range, 38-120 mj); for the buckling theory, the predicted theoretical energy is 68 mj (range, 40-106 mj). CONCLUSION: Through this study, we have experimentally determined the amount of energy required to fracture the bone of the human orbital floor directly and have provided support for each mechanism of the orbital blow-out fracture from a clinical and theoretical basis. Images FIGURE 2 FIGURE 3 FIGURE 4 FIGURE 5A FIGURE 5B FIGURE 5E FIGURE 5F PMID:10703119

  8. Mediastinal emphysema following fracture of the orbital floor

    PubMed Central

    Abdelrahman, Husham; Shunni, Adam; El-Menyar, Ayman; Ajaj, Ahmad; Afifi, Ibrahim; Zarour, Ahmad; Al-Thani, Hassan

    2014-01-01

    Pneumomediastinum (PM) is mainly an atypical finding among traumatic neck or thoracic injury patients. Moreover, PM secondary to isolated orbital floor fracture remains a rare event which is infrequently associated with severe complications such as mediastinitis, airway obstruction and pneumothorax. Herein, we report an atypical case of mediastinal emphysema consequent to orbital floor fracture along with review of the literature. PMID:24876504

  9. Antiferromagnetic Domain Wall Motion Driven by Spin-Orbit Torques.

    PubMed

    Shiino, Takayuki; Oh, Se-Hyeok; Haney, Paul M; Lee, Seo-Won; Go, Gyungchoon; Park, Byong-Guk; Lee, Kyung-Jin

    2016-08-19

    We theoretically investigate the dynamics of antiferromagnetic domain walls driven by spin-orbit torques in antiferromagnet-heavy-metal bilayers. We show that spin-orbit torques drive antiferromagnetic domain walls much faster than ferromagnetic domain walls. As the domain wall velocity approaches the maximum spin-wave group velocity, the domain wall undergoes Lorentz contraction and emits spin waves in the terahertz frequency range. The interplay between spin-orbit torques and the relativistic dynamics of antiferromagnetic domain walls leads to the efficient manipulation of antiferromagnetic spin textures and paves the way for the generation of high frequency signals from antiferromagnets. PMID:27588878

  10. Delayed Periorbital Abscess after Silicone Implant to Orbital Floor Fracture.

    PubMed

    Dedhia, Raj; Tollefson, Travis T

    2016-06-01

    There is a lack of consensus regarding preferred implant materials for orbital floor fracture reconstruction, leading to surgeon- and institution-dependent preferences. A variety of implants are used for orbital floor fracture reconstruction, each with their own complication profile. Knowledge of different implant materials is critical to identifying complications when they present. We report a delayed periorbital abscess 5 years after orbital floor reconstruction using a silicone implant. PMID:27162580

  11. Orbital Roof Fractures: A Clinically Based Classification and Treatment Algorithm.

    PubMed

    Connon, Felicity Victoria; Austin, S J B; Nastri, A L

    2015-09-01

    Orbital roof fractures are relatively uncommon in craniofacial surgery but present a management challenge due to their anatomy and potential associated injuries. Currently, neither a classification system nor treatment algorithm exists for orbital roof fractures, which this article aims to provide. This article provides a literature review and clinical experience of a tertiary trauma center in Australia. All cases admitted to the Royal Melbourne Hospital with orbital roof fractures between January 2011 and July 2013 were reviewed regarding patient characteristics, mechanism, imaging (computed tomography), and management. Forty-seven patients with orbital roof fractures were treated. Three of these were isolated cases. Forty were male and seven were female. Assault (14) and falls (13) were the most common causes of injury. Forty-two patients were treated conservatively and five had orbital roof repairs. On the basis of the literature and local experience, we propose a four-point system, with subcategories allowing for different fracture characteristics to impact management. Despite the infrequency of orbital roof fractures, their potential ophthalmological, neurological, and functional sequelae can carry a significant morbidity. As such, an algorithm for management of orbital roof fractures may help to ensure appropriate and successful management of these patients. PMID:26269727

  12. Reduction of nasal orbital fractures and simultaneous dacryocystorhinostomy.

    PubMed

    Smith, B

    1976-01-01

    A technique for restoration of structure and function in naso-orbital fractures has been described. Three case reports demonstrate a few of the final results. The case reports also indicate that many of these fractures require late definitive surgery in spite of optimal surgical treatment immediately subsequent to injury. PMID:1020097

  13. Long-term infectious complications of using porous polyethylene mesh for orbital fracture reconstruction

    PubMed Central

    Song, Xuefei; Li, Lunhao; Sun, Yiyuan; Fan, Xianqun; Li, Zhengkang

    2016-01-01

    Abstract Porous polyethylene is a widely used implants in orbital reconstruction, on which comprehensive clinical analysis, various treatments, and different prognosis according to specific classification principles on long-term complications have not been reported. To investigate the new clinical symptoms, intraoperative findings, treatments, and outcomes of complications long period after previous surgery, resulting from the use of porous polyethylene mesh for orbital fracture reconstruction. A retrospective study was conducted on 21 patients at the Department of Ophthalmology, Shanghai Ninth People's Hospital with orbital complications after orbital fracture reconstruction with porous polyethylene mesh for 4 ± 2.2 years from 2011 to 2013. These data included new clinical symptoms after previous surgery, computerized tomography data, intraoperative findings, treatments, and outcomes. Data from 21 patients were analyzed in this study. Two patients received conservative treatment, while the other 19 patients underwent surgical approaches. Classification principles for orbital complications after orbital wall defect reconstruction with porous polyethylene mesh were formulated according to patients’ new clinical symptoms, computed tomography (CT), and intraoperative findings after previous surgery. In the last follow-up, 19 patients (90.5%) were cured or improved according to our assessment principle. The follow-up ranged from 3 to 45 months (35 months in average). According to specific classification for orbital complications resulting from the use of porous polyethylene mesh for orbital fracture reconstruction, various medical treatments should be carried out, and the prognosis may be different. PMID:27336867

  14. Comparative Orbital Volumes between a Single Incisional Approach and a Double Incisional Approach in Patients with Combined Blowout Fracture

    PubMed Central

    Park, Sang Wook; Seo, Bommie F.; Rhie, Jong Won; Ahn, Sang Tae; Oh, Deuk Young

    2015-01-01

    Purpose. Blowout fracture characterized by concurrent floor and medial wall fractures is a rare entity. We compared surgical outcomes between a single approach and a double approach in patients with orbital fracture by measuring the postoperative orbital volume. Methods. We confirmed that 21 (8.5%) of a total of 246 patients with orbital fractures had fractures of the medial wall and floor through a retrospective chart review. Of these, 10 patients underwent the single approach and the remaining 11 patients had the double approach. We performed a statistical analysis of changes between the preoperative and postoperative orbital volumes at a 6-month follow-up. Results. Compared with the contralateral, nonaffected side, the orbital volume was 115.3 (±6.09)% preoperatively and 106.5 (±6.15)% postoperatively in the single approach group and 118.2 (±11.16)% preoperatively and 108.6 (±13.96)% postoperatively in the double approach. These results indicated that there was a significant difference between the preoperative and postoperative orbital volumes in each group (P < 0.05). However there was no significant difference between the single approach and the double approach (P > 0.05). Conclusions. Our results showed that there were no significant differences in surgical outcomes between the two modalities. The treatment modality may be selected based on the surgeons' preference, as well as the fracture type. PMID:25961049

  15. Impact oscillators with homoclinic orbit tangent to the wall

    NASA Astrophysics Data System (ADS)

    Du, Zhengdong; Li, Yurong; Shen, Jun; Zhang, Weinian

    2013-02-01

    Homoclinic bifurcation for a nonlinear inverted pendulum impacting between two rigid walls under external periodic excitation is analyzed under the hypothesis that the unperturbed system has a homoclinc orbit tangent to the wall. Consequently, the impact surface cannot be chosen as the Poincaré section to measure the distance between the perturbed stable and unstable manifolds. Furthermore, compared to the case that the unperturbed homoclinic orbit intersects the wall transversally, more cases are involved as the parameters vary. Thus the analysis of the homoclinic orbit tangent to the wall is much more difficult. In this paper, by using a method of Melnikov type, we derive sufficient conditions under which the perturbed stable and unstable manifolds intersect transversally. As an application, an impact oscillator of Duffing type is studied in detail.

  16. Spontaneous Resorption of a Penetrating Orbital Bone Fracture Fragment.

    PubMed

    Campbell, Ashley A; Cunnane, Mary Elizabeth; Dunn, Gavin P; Gray, Stacy Tutt; Lefebvre, Daniel R

    2015-01-01

    The authors describe a 20-year-old man who sustained multiple facial fractures in a high-speed motor vehicle crash, including a bone fragment from a skull base fracture that penetrated the orbital soft tissues superomedially. Serial CT scans documented spontaneous resorption over a 6-month period. While it is known that autologous bone grafts used in craniofacial reconstruction exhibit variable amounts of bone resorption, the complete resorption of an intraorbital fracture fragment has not been documented in the literature. His clinical care and the report of his case were undertaken in a fashion in accordance with the principles of the Health Insurance Portability and Accountability Act regulations. PMID:24833452

  17. Bifurcating Particle Swarms in Smooth-Walled Fractures

    NASA Astrophysics Data System (ADS)

    Pyrak-Nolte, L. J.; Sun, H.

    2010-12-01

    Particle swarms can occur naturally or from industrial processes where small liquid drops containing thousands to millions of micron-size to colloidal-size particles are released over time from seepage or leaks into fractured rock. The behavior of these particle swarms as they fall under gravity are affected by particle interactions as well as interactions with the walls of the fractures. In this paper, we present experimental results on the effect of fractures on the cohesiveness of the swarm and the formation of bifurcation structures as they fall under gravity and interact with the fracture walls. A transparent cubic sample (100 mm x 100 mm x 100 mm) containing a synthetic fracture with uniform aperture distributions was optically imaged to quantify the effect of confinement within fractures on particle swarm formation, swarm velocity, and swarm geometry. A fracture with a uniform aperture distribution was fabricated from two polished rectangular prisms of acrylic. A series of experiments were performed to determine how swarm movement and geometry are affected as the walls of the fracture are brought closer together from 50 mm to 1 mm. During the experiments, the fracture was fully saturated with water. We created the swarms using two different particle sizes in dilute suspension (~ 1.0% by mass). The particles were 3 micron diameter fluorescent polymer beads and 25 micron diameter soda-lime glass beads. Experiments were performed using swarms that ranged in size from 5 µl to 60 µl. The swarm behavior was imaged using an optical fluorescent imaging system composed of a CCD camera illuminated by a 100 mW diode-pumped doubled YAG laser. As a swarm falls in an open-tank of water, it forms a torroidal shape that is stable as long as no ambient or background currents exist in the water tank. When a swarm is released into a fracture with an aperture less than 5 mm, the swarm forms the torroidal shape but it is distorted because of the presence of the walls. The

  18. Transantral Orbital Floor Fracture Repair Using a Folded Silastic Tube

    PubMed Central

    Kim, Joo Yeon; Choi, Gwan

    2015-01-01

    Objectives The purpose of this study was to evaluate the advantages and limitations of using a silicon tube to support the fractured orbital floor by a transantral approach. Methods A retrospective study was conducted from January 2000 to December. 2011 in 51 patients with pure orbital floor fractures. The patients underwent reduction surgery via a transantral approach for inserting a folded silastic tube to support the fractured orbital floor in the maxillary sinus. A chart review of preoperative and postoperative ocular symptoms, operation records, and complications was maintained. Results In 18 out of 25 patients with diplopia, postoperative improvement was seen. In 13 out of 15 patients with extraocular muscle limitation, postoperative improvement was seen. Enophthalmos resolved postoperatively in four of five patients. Postsurgical complications occurred in three patients: an overcorrection, an infection in the maxillary sinus, and an implant extrusion, all of which were resolved by revision surgeries. Conclusion During the course of the study, we sensed reduction using a folded silastic tube via a transantral approach as an easy and effective technique with good postoperative results, and minimal implant related complications. This novel procedure is recommended as a surgical option for the reduction of orbital floor fractures. PMID:26330920

  19. Water infiltration and intermittent flow in rough-walled fractures

    SciTech Connect

    Su, G.

    1995-05-01

    Flow visualization experiments were conducted in transparent replicas of natural rough-walled fractures. The fracture was inclined to observe the interplay between capillary and gravity forces. Water was introduced into the fracture by a capillary siphon. Preferential flow paths were observed, where intermittent flow frequently occurred. The water infiltration experiments suggest that intermittent flow in fractures appears to be the rule rather than the exception. In order to investigate the mechanism causing intermittent flow in fractures, parallel plates with different apertures were assembled using lucite and glass. A medium-coarse-fine pore structure is believed to cause the intermittency in flow. Intermittent flow was successfully produced in the parallel plate experiments using the lucite plates. After several trials, intermittent flow was also produced in the glass plates.

  20. Orbital wall infarction in child with sickle cell disease.

    PubMed

    Janssens, C; Claeys, L; Maes, P; Boiy, T; Wojciechowski, M

    2015-12-01

    We present the case of a 17-year-old boy, known with homozygous sickle cell disease, who was admitted because of generalised pain. He developed bilateral periorbital oedema and proptosis, without pain or visual disturbances. In addition to hyperhydration, oxygen and analgesia IV antibiotics were started, to cover a possible osteomyelitis. Patients with sickle cell disease are at risk for vaso-occlusive crises, when the abnormally shaped red blood cells aggregate and block the capillaries. Such a crisis typically presents at a location with high bone marrow activity, as the vertebrae and long bones. At an early age, the bone marrow is still active at other sites, for example the orbital wall, and thus infarction can also occur there. Thus, in young persons with sickle cell disease, it is important to consider orbital wall infarction in the differential diagnosis, since the approach is different from osteomyelitis. If the disease is complicated by an orbital compression syndrome, corticosteroids or surgical intervention may be necessary to preserve the vision. In our patient, an MRI of the orbitae demonstrated periorbital oedema with bone anomalies in the orbital and frontal bones, confirming orbital wall infarction. Ophthalmological examination revealed no signs of pressure on the nervus opticus. The patient recovered gradually with conservative treatment. PMID:26790559

  1. Materials used for reconstruction after orbital floor fracture.

    PubMed

    Avashia, Yash J; Sastry, Ananth; Fan, Kenneth L; Mir, Haaris S; Thaller, Seth R

    2012-11-01

    Advances in biotechnology continue to introduce new materials for reconstruction of orbital floor fractures. Which material is best fit for orbital floor reconstruction has been a controversial topic. Individual surgeon preferences have been supported by inconsistent inconclusive data. The purpose of this study was to assess and analyze published evidence supporting various materials used for orbital floor reconstruction and to develop a decision-making algorithm for clinical application. A systematic literature review was performed from which 48 studies were selected after primary and secondary screening based on set inclusion and exclusion criteria. This cumulatively included 3475 separate orbital floor reconstructions. Results revealed risk and benefit profiles for all materials. Autologous calvarial bone grafts, porous polyethylene, and polydioxanone (PDS) were most widely used for orbital floor reconstruction. Increased infection rates were reported with polyglactin 910/PDS composites and silastic rubber. Ocular motility was reduced most with lyophilized dura and PDS. Preoperative and postoperative rates for diplopia and enophthalmos varied among the materials. In conclusion, our results revealed continued inadequate evidence to exclusively support the use of any one biomaterial/implant for orbital floor reconstruction. Results have served to create a decision-making algorithm for clinical application. Our authors propose certain parameters for future studies seeking to demonstrate a comparison between 2 or more materials for orbital floor reconstruction. PMID:23154365

  2. Orbital fractures: a new classification and staging of 190 patients.

    PubMed

    Carinci, Francesco; Zollino, Ilaria; Brunelli, Giorgio; Cenzi, Roberto

    2006-11-01

    The orbit is located in the middle third of the face, composed of several bones and surrounded by complex anatomic structures so that orbital fractures (OF) often involve other parts of the face. A staging system for classifying OF is of paramount importance in order to exchange information between trauma centers. Several classifications have been proposed for describing OF but they have not a single method applicable to the whole orbit. Here, a classification for OF that can be summarized with four abbreviations is proposed. Four letters define the localization (F = frontal, N = nasal, M = maxillary and Z = zygomatic bone fracture), two acronyms describe fragment shift (in = blow-in or out = blow-out), four numbers define ocular movement impairment (1 = superior, 2 = internal, 3 = inferior, and 4 = external extrinsic muscular deficit) and two acronyms describe eye position (EX = exophthalmos and ENO = enophthalmos). To evaluate the suitability of the proposed classification a retrospective study on a series of 190 OFs is performed. Age, gender, new stage, clinical diagnosis at admission, type of surgery, and need for graft for orbital reconstruction are considered. A good correlation between the proposed classification and the studied variables is detected. In conclusion, the proposed classification is a simply and precise method to stage OF. It can summarize OF and be used in the daily practice. However, it is our belief that a multi-center study should be performed before the effectiveness of the proposed classification can be clearly stated. PMID:17119402

  3. Boiling radial flow in fractures of varying wall porosity

    SciTech Connect

    Barnitt, Robb Allan

    2000-06-01

    The focus of this report is the coupling of conductive heat transfer and boiling convective heat transfer, with boiling flow in a rock fracture. A series of experiments observed differences in boiling regimes and behavior, and attempted to quantify a boiling convection coefficient. The experimental study involved boiling radial flow in a simulated fracture, bounded by a variety of materials. Nonporous and impermeable aluminum, highly porous and permeable Berea sandstone, and minimally porous and permeable graywacke from The Geysers geothermal field. On nonporous surfaces, the heat flux was not strongly coupled to injection rate into the fracture. However, for porous surfaces, heat flux, and associated values of excess temperature and a boiling convection coefficient exhibited variation with injection rate. Nucleation was shown to occur not upon the visible surface of porous materials, but a distance below the surface, within the matrix. The depth of boiling was a function of injection rate, thermal power supplied to the fracture, and the porosity and permeability of the rock. Although matrix boiling beyond fracture wall may apply only to a finite radius around the point of injection, higher values of heat flux and a boiling convection coefficient may be realized with boiling in a porous, rather than nonporous surface bounded fracture.

  4. Lateral Orbital Wall Destruction Due to Pilonidal Sinus.

    PubMed

    Karadağ, Emine Çiğdem; Toy, Hatice; Tosun, Zekeriya

    2016-07-01

    Pilonidal sinus is a chronic inflammatory disease commonly observed in the sacrococcygeal region. The authors report a patient of a pilonidal sinus in a rare location-the lateral orbital region. The authors' patient was misdiagnosed with an epidermal cyst, and the subsequent incomplete excision of the sinus tract led a pilonidal sinus with a high morbidity resulting in the destruction of bone tissue in the lateral orbital wall. It was, therefore, crucial to accurately diagnose and treat before the infection progressed through the bone and caused osteomyelitis. PMID:27391513

  5. Biodegradable polymers: Wall slip, melt fracture, and processing aids

    NASA Astrophysics Data System (ADS)

    Othman, Norhayani; Noroozi, Nazbanoo; Jazrawi, Bashar; Mehrkhodavandi, Parisa; Schafer, Laurel; Hatzikiriakos, Savvas George

    2015-04-01

    The wall slip and melt fracture behaviour of several commercial polylactides (PLAs) and poly(ɛ-caprolactone), (PCLs) have been investigated. PLAs with molecular weights greater than a certain value were found to slip, with the slip velocity to increase with decrease of molecular weight consistent with wall slip data reported in the literature for other systems. The onset of melt fracture for the high molecular weight PLAs was found to occur at about 0.2 to 0.3 MPa, depending on the geometrical characteristics of the dies and independent of temperature. Similarly, sharkskin and gross melt fracture was observed for the case of PCLs depending on the molecular characteristics of the resins and the geometrical details of the capillary dies. It was also found that the addition of a small amount of PCL (typically 0.5 wt.%) into the PLA and vice versa is effective in eliminating and delaying the onset of melt fracture to higher shear rates in the capillary extrusion of PLA and PCL respectively. This is due to significant interfacial slip that occurs in the presence of PCL or PLA as well as to the immiscibility of the PLA/PCL blend system at all compositions.

  6. Peribulbar anesthesia for the repair of orbital floor fractures.

    PubMed

    Kezirian, G M; Hill, F D; Hill, F J

    1991-10-01

    Four patients underwent successful repair of an isolated orbital floor fracture under local anesthesia. The surgical approach was by antero-inferior orbitotomy, with placement of a Nylamid plate (S Jackson Inc, Washington, DC). The anesthetic technique used was a peribulbar and infratrochlear nerve block with local supplementation. Digital control of the globe was maintained during the peribulbar injection to prevent ocular perforation. We conclude that local anesthetic for this procedure in carefully selected cases is safe and efficacious, avoiding the morbidity of a general anesthetic. PMID:1961618

  7. Diagnosis and imaging of orbital roof fractures: a review of the current literature.

    PubMed

    Righi, Stefano; Boffano, Paolo; Guglielmi, Valeria; Rossi, Paolo; Martorina, Massimo

    2015-03-01

    Isolated adult orbital roof fractures are uncommon, and the majority of them are typically associated with extensive craniofacial, ophthalmologic, and other body injuries. It is crucial to make an appropriate diagnosis of orbital roof fracture if present. Therefore, the aim of this article was to review the current literature about diagnosis and imaging of orbital roof fracture to obtain current indications. A systematic review of articles published between January 1990 and August 2013 was performed. Early diagnosis of orbital roof fractures can reduce the incidences of intracranial and ocular complications. CT scan still plays a major role in the assessment of acute orbital trauma. Careful assessment and reporting of the CT scan findings are important. In fact, the clinicians managing the patient with acute head and facial trauma should be familiar with the common findings of CT scan in case of an orbital roof fracture. PMID:25582115

  8. Orbital blow-out fractures: correlation of preoperative computed tomography and postoperative ocular motility.

    PubMed Central

    Harris, G J; Garcia, G H; Logani, S C; Murphy, M L; Sheth, B P; Seth, A K

    1998-01-01

    BACKGROUND/PURPOSE: Although the management of orbital blow-out fractures was controversial for many years, refined imaging with computed tomography (CT) helped to narrow the poles of the debate. Many orbital surgeons currently recommend repair if fracture size portends late enophthalmos, or if diplopia has not substantially resolved within 2 weeks of the injury. While volumetric considerations have been generally well-served by this approach, ocular motility outcomes have been less than ideal. In one series, almost 50% of patients had residual diplopia 6 months after surgery. A fine network of fibrous septa that functionally unites the periosteum of the orbital floor, the inferior fibrofatty tissues, and the sheaths of the inferior rectus and oblique muscles was demonstrated by Koornneef. Entrapment between bone fragments of any of the components of this anatomic unit can limit ocular motility. Based on the pathogenesis of blow-out fractures, in which the fibrofatty-muscular complex is driven to varying degrees between bone fragments, some measure of soft tissue damage might be anticipated. Subsequent intrinsic fibrosis and contraction can tether globe movement, despite complete reduction of herniated orbital tissue from the fracture site. We postulated that the extent of this soft tissue damage might be estimated from preoperative imaging studies. METHODS: Study criteria included: retrievable coronal CT scans; fractures of the orbital floor without rim involvement, with or without extension into the medial wall; preoperative diplopia; surgical repair by a single surgeon; complete release of entrapped tissues; and postoperative ocular motility outcomes documented with binocular visual fields (BVFs). Thirty patients met all criteria. The CT scans and BVFs were assessed by different examiners among the authors. Fractures were classified into 3 general categories and 2 subtypes to reflect the severity of soft tissue damage within each category. "Trap-door" injuries

  9. Orthoptic Sequelae Following Conservative Management of Pure Blowout Orbital Fractures: Anecdotal or Clinically Relevant?

    PubMed

    Steinegger, Ken; De Haller, Raoul; Courvoisier, Delphine; Scolozzi, Paolo

    2015-07-01

    The aim of this study was to prospectively assess the prevalence of orthoptic anomalies following conservative management of pure blowout orbital fractures and to evaluate their clinical relevance. Clinical and radiologic data of patients with unilateral conservatively managed pure blowout orbital fractures with a minimum follow-up of 6 months were reviewed. Eligible patients were contacted and invited to undergo an extended ophthalmologic examination as follows: distance and near visual acuities, Hertel exophthalmometry, corneal light reflex (Hirschberg test), ductions and versions in the 6 cardinal fields of gaze, eye deviation with prisms and alternate cover test in all of the 9-gaze directions with Maddox rod, degrees of incyclo/excyclotorsion with right and left eye fixation, horizontal and vertical deviation with Hess-Weiss coordimetry, degree of horizontal/vertical and incyclo/excyclotorsion deviation with Harms wall deviometry, and vertical deviation with Bielschowsky head-tilt test. Of the 69 patients contacted, 49 declined to participate given that they were asymptomatic. Twenty patients agreed to undergo the examination. One patient complained of minimal double vision limited to the extreme downgaze. Four patients had asymptomatic ocular motility disturbances limited to the extreme gaze. Seven patients had asymptomatic horizontal heterophoria. These disturbances did not interfere with daily or professional activities in any of the patients. The current study demonstrated that conservative management of pure orbital blowout fractures can result in orthoptic anomalies. These sequelae were restricted to a very limited portion of the binocular field of the vision and were not found to be clinically relevant. PMID:26102539

  10. Sustained chiral magnetic domain wall motion driven by spin-orbit torques under the tilted current

    NASA Astrophysics Data System (ADS)

    He, Peng-Bin; Yan, Han; Cai, Meng-Qiu; Li, Zai-Dong

    2016-06-01

    We theoretically investigate the steady magnetic domain wall driven by spin-orbit torques in the heavy-metal/magnet bilayers with perpendicular anisotropy. Based on collective coordinates method and stability analysis, we analyze the effects of tilted current and Dzyaloshinskii-Moriya interaction on the wall. We find that the wall acquires a sustained motion in the high-current regime by deviating the current from the wall track. Also, a persistent motion can be supported by the competition between spin-orbit torques and Dzyaloshinskii-Moriya interaction in transforming wall type. In the low-current regime, there exist a switching of wall chirality and a reversal of wall motion.

  11. Arthroscopic Reduction and Transportal Screw Fixation of Acetabular Posterior Wall Fracture: Technical Note.

    PubMed

    Park, Jin Young; Chung, Woo Chull; Kim, Che Keun; Huh, Soon Ho; Kim, Se Jin; Jung, Bo Hyun

    2016-06-01

    Acetabular fractures can be treated with variable method. In this study, acetabular posterior wall fracture was treated with arthroscopic reduction and fixation using cannulated screw. The patient recovered immediately and had a satisfactory outcome. In some case of acetabular fracture could be good indication with additional advantages of joint debridement and loose body removal. So, we report our case with technical note. PMID:27536654

  12. Arthroscopic Reduction and Transportal Screw Fixation of Acetabular Posterior Wall Fracture: Technical Note

    PubMed Central

    Park, Jin young; Kim, Che Keun; Huh, Soon Ho; Kim, Se Jin; Jung, Bo Hyun

    2016-01-01

    Acetabular fractures can be treated with variable method. In this study, acetabular posterior wall fracture was treated with arthroscopic reduction and fixation using cannulated screw. The patient recovered immediately and had a satisfactory outcome. In some case of acetabular fracture could be good indication with additional advantages of joint debridement and loose body removal. So, we report our case with technical note. PMID:27536654

  13. Hydraulic fracturing model featuring initiation beyond the wellbore wall for directional well in coal bed

    NASA Astrophysics Data System (ADS)

    Li, Yuwei; Jia, Dan; Wang, Meng; Liu, Jia; Fu, Chunkai; Yang, Xinliang; Ai, Chi

    2016-08-01

    In developing internal fracture systems in coal beds, the initiation mechanism differs greatly from that of conventional ones and initiations may be produced beyond the wellbore wall. This paper describes the features of the internal structure of coal beds and RFPA2D simulation is used to attest the possible occurrence of initiation beyond the wellbore wall in coal bed hydraulic fracturing. Using the theory of elasticity and fracture mechanics, we analyse the stress distribution in the vicinal coal rock. Then by taking into consideration the effects of the spatial relationship between coal bed cleats and the wellbore, we establish a model for calculating both tensile and shear initiation pressure that occur along cleats beyond the wellbore wall. The simulation in this paper indicates that for shear initiations that happen along coal cleats, the pressure required to initiate fracture for cleats beyond the wellbore wall is evidently lower than that on the wellbore wall, thus it is easier to initiate shear fractures for cleats beyond the wellbore wall. For tensile failure, the pressure required to initiate tensile fracture for cleats beyond the wellbore wall is obviously higher than that for cleats at the wellbore wall, thus it is easier to initiate tensile fractures for cleats at the wellbore wall. On the one hand, this paper has proved the possible occurrence of initiations beyond the wellbore wall and has changed the current assumption that hydraulic fractures can only occur at the wellbore wall. On the other hand, the established theoretical model provides a new approach to calculating the initiation pressure in hydraulic fracturing.

  14. Factors Associated with Significant Ocular Injury in Conservatively Treated Orbital Fractures

    PubMed Central

    Layton, Christopher J.

    2014-01-01

    Purpose. To determine factors associated with the presence of significant ocular injury in subjects with orbital fractures. Subjects. A consecutive prospective cohort of 161 patients presenting to a general tertiary referral hospital with orbital fractures and undergoing initial conservative treatment was identified. Subjects were assessed at time of injury for the need for emergency surgery, and those initially treated conservatively were subsequently followed up by the Ophthalmology Department to assess for ocular injury requiring ophthalmic management at 1–7 days after injury. Associations between ocular injury and age, sex, visual acuity, presence of blowout fracture, extent of orbital involvement, and presence of distant facial fractures were assessed. Results. 142 male (average age of 32 [95% CI 30–35]) and 19 female (average age of 49 [95% CI 39–59]) subjects were identified. 17 subjects were diagnosed with significant ocular injury. Ocular injury was significantly associated with LogMAR VA worse than 0.2 (OR 49 [95% CI 11–217, P < 0.0001]), but no relationship was noted for age, sex, presence of blowout fracture, extent of fractures, or presence of distal facial fractures. LogMAR visual acuity worse than or equal to 0.2 had a 98% negative predictive value for ocular injury in the setting of orbital fractures. Conclusions. Demographic and nonophthalmic fracture characteristics were not useful predictors of ocular injury in orbital fractures. LogMAR visual acuity worse than or equal to 0.2 is a highly sensitive and useful guide of the need for ophthalmic referral in subjects with orbital fractures. PMID:25580279

  15. Factors associated with significant ocular injury in conservatively treated orbital fractures.

    PubMed

    Layton, Christopher J

    2014-01-01

    Purpose. To determine factors associated with the presence of significant ocular injury in subjects with orbital fractures. Subjects. A consecutive prospective cohort of 161 patients presenting to a general tertiary referral hospital with orbital fractures and undergoing initial conservative treatment was identified. Subjects were assessed at time of injury for the need for emergency surgery, and those initially treated conservatively were subsequently followed up by the Ophthalmology Department to assess for ocular injury requiring ophthalmic management at 1-7 days after injury. Associations between ocular injury and age, sex, visual acuity, presence of blowout fracture, extent of orbital involvement, and presence of distant facial fractures were assessed. Results. 142 male (average age of 32 [95% CI 30-35]) and 19 female (average age of 49 [95% CI 39-59]) subjects were identified. 17 subjects were diagnosed with significant ocular injury. Ocular injury was significantly associated with LogMAR VA worse than 0.2 (OR 49 [95% CI 11-217, P < 0.0001]), but no relationship was noted for age, sex, presence of blowout fracture, extent of fractures, or presence of distal facial fractures. LogMAR visual acuity worse than or equal to 0.2 had a 98% negative predictive value for ocular injury in the setting of orbital fractures. Conclusions. Demographic and nonophthalmic fracture characteristics were not useful predictors of ocular injury in orbital fractures. LogMAR visual acuity worse than or equal to 0.2 is a highly sensitive and useful guide of the need for ophthalmic referral in subjects with orbital fractures. PMID:25580279

  16. Numerical simulations examining the relationship between wall-roughness and fluid flow in rock fractures

    SciTech Connect

    Crandall, Dustin; Bromhal, Grant; Karpyn, Zuleima T.

    2010-07-01

    Understanding how fracture wall-roughness affects fluid flow is important when modeling many subsurface transport problems. Computed tomography scanning provides a unique view of rock fractures, allowing the measurement of fracture wall-roughness, without destroying the initial rock sample. For this computational fluid dynamics study, we used several different methods to obtain three-dimensional meshes of a computed tomography scanned fracture in Berea sandstone. These volumetric meshes had different wall-roughnesses, which we characterized using the Joint Roughness Coefficient and the fractal dimension of the fracture profiles. We then related these macroscopic roughness parameters to the effective flow through the fractures, as determined from Navier-Stokes numerical models. Thus, we used our fracture meshes to develop relationships between the observed roughness properties of the fracture geometries and flow parameters that are of importance for modeling flow through fractures in field scale models. Fractures with high Joint Roughness Coefficients and fractal dimensions were shown to exhibit tortuous flow paths, be poorly characterized by the mean geometric aperture, and have a fracture transmissivity 35 times smaller than the smoother modeled fracture flows.

  17. Treatment of Orbital Roof Blow-Up Fracture Using a Superior Blepharoplasty Incision.

    PubMed

    Matsuzaki, Kyoichi; Enomoto, Sayaka; Aoki, Tomoko

    2015-06-01

    In orbital roof blow-up fractures, reduction can be achieved easily using an approach from the anterior cranial fossa but the procedure is highly invasive. In contrast, an orbital approach using a superior blepharoplasty incision is minimally invasive. However, if bone fragments are adhered to the dura mater, there is a risk of dura mater injury when fragments are moved for reduction. In blow-in fractures, reduction is performed by pushing the bone fragments against the anterior cranial fossa. In contrast, the procedure is difficult for blow-up fractures because bone fragments must be pulled out into the orbit through the anterior cranial fossa. Orbital blow-up fractures are often associated with intracranial injuries and frequently treated by an approach from the anterior cranial fossa. There has not yet been a report that discusses whether reduction of bone fragments should be performed in blow-up fracture without intracranial injury. In this report, we describe two cases of orbital roof blow-up fracture that did not require treatment for intracranial injury and that were treated using an orbital approach. The treatment involved only the release of orbital fat entrapped between bone fragments and did not involve reduction. The treatment outcomes were good in both cases. PMID:25836594

  18. Emergency decompression of tension retrobulbar emphysema secondary to orbital floor fracture.

    PubMed

    Tomasetti, Patrick; Jacbosen, Christine; Gander, Thomas; Zemann, Wolfgang

    2013-01-01

    Orbital floor fractures are generally the result of blowout orbital and may be associated with orbital emphysema leading to proptosis and even to loss of vision. A 49-year-old woman fractured the orbital floor in a fall. After blowing her nose, she developed exophthalmos and severe reduction in vision. She consulted our department and underwent emergency surgical management with orbital drainage. Decompression led to immediate resolution of the exophthalmos and postoperative improvement in visual acuity. Urgent decompression is indicated by the presence of proptosis, elevated intraocular pressure, and progressive loss of vision in cases of orbital trauma with additional emphysema. Surgical treatment of tension emphysema includes lateral canthotomy or cantholysis, needle aspiration, transconjunctival, or lateral blepharoplasty approach, and bone decompression depending on the severity of the case. Sneezing or blowing the nose can lead to proptosis and decreased visual acuity secondary to trauma to the orbit. Under such circumstances, emergency decompression is essential. PMID:24964422

  19. Blowout fracture of the orbital floor secondary to vigorous nose blowing.

    PubMed

    Halpenny, D; Corbally, C; Torreggiani, W

    2012-01-01

    Orbital floor fracture due to vigorous nose blowing in the absence of mechanical trauma is rare, only four cases having previously been reported. In each of these cases, predisposing factors have been identified; preceding URTI in three and a history of sino-nasal surgery in the fourth case. We present the case of a 49-year-old woman who developed a maxillary sinus fracture and orbital emphysema after blowing her nose. PMID:23008887

  20. The Merits of Mannitol in the Repair of Orbital Blowout Fracture

    PubMed Central

    Shin, Kyung Jin; Lee, Dong Geun; Park, Hyun Min; Choi, Mi Young; Bae, Jin Ho

    2013-01-01

    Background One of the main concerns in orbital blowout fracture repair is a narrow operation field, due mainly to the innate complex three dimensions of the orbit; however, a deep location and extensive area of the fracture and soft tissue edema can also cause concern. Swelling of the orbital contents progresses as the operation continues. Mannitol has been used empirically in glaucoma, cerebral hemorrhage, and orbital compartment syndrome for decompression. The authors adopted mannitol for the control of intraorbital edema and pressure in orbital blowout fracture repair. Methods This prospective study included 108 consecutive patients who were treated for a pure blowout fracture from January 2007 to October 2012. For group I, mannitol was administered during the operation. Under general anesthesia, all patients underwent surgery by open reduction and insertion of an absorbable mesh implant. The authors compared postoperative complications, the reoperation rate, operation time, and surgical field improvement between the two groups. Results In patients who received intraoperative administration of mannitol, the reoperation rate and operation time were decreased; however, the difference was not statistically significant. The total postoperative complication rates did not differ. Panel assessment for the intraoperative surgical field video recordings showed significantly improved vision in group I. Conclusions For six years, mannitol proved itself an effective, reliable, and safe adjunctive drug in the repair of orbital blowout fractures. With its rapid onset and short duration of action, mannitol could be one of the best methods for obtaining a wider surgical field in blowout fracture defects. PMID:24286045

  1. "Roller coaster maneuver via lateral orbital approach" for reduction of isolated zygomatic arch fractures.

    PubMed

    Pilanci, Ozgur; Basaran, Karaca; Datli, Asli; Kuvat, Samet Vasfi

    2013-11-01

    Numerous techniques have been reported for the reduction of zygomatic arch fractures. In this article, we aimed to describe a technique we named as "roller coaster maneuver via lateral orbital approach" to closed reduction of the isolated-type zygomatic arch fractures. Surgical outcomes of 14 patients treated with this method were outlined. PMID:24220411

  2. Effect of Surface Wettability on Nonlinear Flow in a Rough-Walled Fracture

    NASA Astrophysics Data System (ADS)

    Lee, H.; Yeo, I.; Park, J.; Lee, K.

    2005-12-01

    The understanding of flow behavior in rock fractures is essential to the analysis of water flow, solute transport and DNAPL migration and remediation in rock fractures. DNAPL migration and remediation in rock fractures has been an emerging issue due to its serious contamination problem and the difficulty in dealing with DNAPL trapped in rock fractures. It has been reported that while DNAPL migrates through rock fractures, DNAPL may be trapped on rock surfaces due to variable apertures and dead-end fractures, and may also change the surface wettability of rock fractures from hydrophilic to hydrophobic. In this study, the effect of surface wettability on water flow in rock fractures has been investigated. A glass replica of a real rough-walled fracture was made, and the fracture surface was brushed with corn oil to make the fracture surface hydrophobic. The corn oil was wiped off with tissues many times, to eliminate the oil remnants on the surface. Flow tests were conducted on the oil-wet fracture surface. Then, the surface was completely washed out with the cleaning agents to make the fracture surface hydrophilic, which was confirmed through contact angle measurements. Flow tests were repeated for the water-wet fracture surface. Flow tests were also carried out for a parallel glass plate fracture over the same water- and oil-wet surface conditions as in the rough fracture. In the parallel plate fracture, the hydraulic aperture from the oil-wet surface was only two percent higher that that of the water-wet surface, which indicated that the initial aperture of the fracture might not decrease by the corn-oil coating. Both oil- and water-wet surfaces of the parallel plate showed a linear flow regime, up to Reynolds number of 400. In the case of the rough fracture, the hydraulic aperture of the oil-wet fracture surface was smaller than that of the water-wet fracture surface. For the water-wet fracture surface, the non-linear flow started at Reynolds number less than 30

  3. Visualization of Fluid Flow through in a Rough-Walled Fracture Using micro-PIV Technique

    NASA Astrophysics Data System (ADS)

    Lee, S.; Yeo, I.; Song, H.; Yoo, J.; Lee, K.

    2010-12-01

    Fluid flow in rough-walled rock fractures have been described by the cubic law and the Reynolds equation which are derived from Navier-Stokes equation. They are based on the assumption of a laminar flow, and basically state that fluid flux is proportional to cube of the aperture of the channel, which yields an ideal parabolic velocity profile across the channel. However, it has been reported that even for low Reynolds numbers (Re), there are discrepancies between analytical/numerical works and experiments. It is questioned whether these assumptions are satisfied in real rough-walled fractures even for Re<1. In order to examine those assumptions, micro-PIV (particle image velocimetry) was introduced, which allowed for direct and microscopic observation of fluid flow in rough-walled fractures. Both surfaces of a rough-walled fracture were scanned, and were then duplicated on acrylics using CNC modeling machine, which formed a rough-walled acrylic fracture with and 450 micrometer average aperture. Deionized water, mixed with 2 micrometer size of fluorescent particle, was injected into the rough-walled acrylic fracture at Re = 0.01, 0.025, 0.05, and 0.10. Velocity vectors were calculated by analyzing relative movement of particles between snap shots. Fluid flow features were primarily monitored at the five representative spots of fracture roughness. As a result, it was found that the laminar flow prevails over the fracture. For Re<1, the velocity profile was highly dependent on fracture roughness. The development of dead spots at which flow velocity was almost zero was remarkable in the regions where apertures change rapidly, which significantly reduces the channel that actually contributes to fluid flow: hydraulic aperture. Further quantitative analysis is in progress to examine whether the cubic law-based analytical solutions are effective for the quantification of fluid flow through rough-walled fractures.

  4. Successful application of endoscopic modified medial maxillectomy to orbital floor trapdoor fracture in a pediatric patient.

    PubMed

    Matsuda, Yasunori; Sakaida, Hiroshi; Kobayashi, Masayoshi; Takeuchi, Kazuhiko

    2016-10-01

    Although surgical treatment of orbital floor fractures can be performed by many different approaches, the application of endoscopic modified medial maxillectomy (EMMM) for this condition has rarely been described in the literature. We report on a case of a 7-year-old boy with a trapdoor orbital floor fracture successfully treated with the application of EMMM. The patient suffered trauma to the right orbit floor and the inferior rectus was entrapped at the orbital floor. Initially, surgical repair via endoscopic endonasal approach was attempted. However, we were unable to adequately access the orbital floor through the maxillary ostium. Therefore, an alternative route of access to the orbital floor was established by EMMM. With sufficient visualization and operating space, the involved orbital content was completely released from the entrapment site and reduced into the orbit. To facilitate wound healing, the orbital floor was supported with a water-inflated urethral balloon catheter for 8 days. At follow-up 8 months later, there was no gaze restriction or complications associated with the EMMM. This case illustrates the efficacy and safety of EMMM in endoscopic endonasal repair of orbital floor fracture, particularly for cases with a narrow nasal cavity such as in pediatric patients. PMID:26926254

  5. Mydriasis during Orbital Floor Fracture Reconstruction: A Novel Diagnostic and Treatment Algorithm

    PubMed Central

    Yeo, Matthew S.; Al-Mousa, Radwan; Sundar, Gangadhara; Lim, Thiam Chye

    2010-01-01

    Orbital floor fractures are the most commonly encountered traumatic fractures in the facial skeleton. Mydriasis that is detected during orbital floor fracture reconstruction may cause significant distress to surgeons, as it may be associated with sinister events such as visual loss. It is not an uncommon problem; previous studies have shown the incidence of mydriasis to be 2.1%. The combination of careful preoperative evaluation and planning, as well as specific intraoperative investigations when mydriasis is encountered, can be immensely valuable in allaying surgeons' anxiety during orbital floor fracture reconstruction. In this review article, the authors discuss the common causes of mydriasis and present a novel systematic approach to its diagnostic evaluation devised by our unit that has been successfully implemented since 2008. PMID:22132259

  6. Solute exchange at the fracture-matrix wall involving significant buoyancy effects - an analog experiment

    NASA Astrophysics Data System (ADS)

    Michel, L.; Meheust, Y.; Bouquain, J.; Caudal, J.; de Bremond D'Ars, J.; de Dreuzy, J.; Davy, P.

    2008-12-01

    Contaminant transport in heterogeneous fractured aquifers occurs mostly through the networks of intersecting fractures. The physical mechanisms of solute transport in a single fracture with impermeable walls are well identified: advection, micro-dispersion (including molecular diffusion) Taylor-Aris dispersion, roughness dispersion, and aperture-variation dispersion. The description of the mass transfert coefficient between the region of high permeability (the fracture) and that of low permeability (the surrounding matrix), when the permeability of the latter cannot be neglected, is in contrast poorly understood. We address here solute transport through a synthetic fracture with a porous wall placed under the fracture, and for which buoyancy effects significantly promote solute exchange at the porous wall. We have developed an analog experimental setup in which the planar horizontal fracture is 1 m long, 5 cm wide and its mean aperture is 5 mm. It is bounded by either two smooth parallel Plexiglass plates (impermeable walls configuration), or by one such plate and a porous medium consisting of 1 mm glass beads ("semi-permeable" configuration). A permanent laminar water flow is forced through the fracture at controlled mean velocity (~ 1mm/s). The flow conditions inside the experimental fracture have been characterized using three-dimensional finite volume numerical simulations of the flow. A dye (patent blue) injection system simulates a point source of contaminant along the center plane of the experimental fracture. The tracer plume is tracked using a visualization system based on (i) lasers illuminating a series of vertical linear optical sensor arrays, and (ii) 4 cameras positioned side by side and providing a composite image of the fracture length, viewed from the side. The two measurement systems yield consistent quantitative temporal descriptions of the tracer concentration, integrated over the fracture width and at several positions along the fracture length

  7. Ipsilateral Traumatic Posterior Hip Dislocation, Posterior Wall and Transverse Acetabular Fracture with Trochanteric Fracture in an adult: Report of First Case

    PubMed Central

    Sinha, Skand; Naik, Ananta k; Arya, Rajendra K; Jain, Vijay K

    2013-01-01

    Introduction: Posterior dislocation of the hip joint with associated acetabular and intertrochanteric fracture is a complex injury. Early recognition, prompt and stable reduction is needed of successful outcome. Case Report: 45 year old male patient presented with posterior dislocation of the hip with transverse fracture with posterior wall fracture of acetabulam and intertrochanteric fracture on the ipsilateral side. The complex fracture geometry was confirmed by CT scan. The patient was successfully managed by open reduction and internal fixation of intertrochanteric fracture was achieved with dynamic hip screw (DHS) plate fixation followed by fixation of acetabular fracture with reconstruction plate. Conclusion: Hip dislocation combined with acetabular fracture is an uncommon injury; this article presents a unique case of posterior wall and transverse fractures of ipsilateral acetabulum with intertrochanteric fracture in a patient who sustained traumatic posterior hip dislocation. Early surgical intervention is important for satisfactory outcomes of such complex fracture-dislocation injuries. PMID:27298928

  8. Longitudinal tear of the inferior rectus muscle in orbital floor fracture.

    PubMed

    Kashima, Tomoyuki; Akiyama, Hideo; Kishi, Shoji

    2012-06-01

    We report a case of longitudinal avulsion of the inferior rectus muscle following orbital floor fracture and describe its clinical presentation, computed tomography (CT) features and management. A 53-year-old man felt vertical diplopia in all gaze immediately after the trauma. Orthoptic assessment showed left over right hypertropia of 20 prism diopters and left exotropia of 10 prism diopters in primary position. The left orbital floor fracture and the prolapse of orbital contents into the maxillary sinus were presented by CT. Exploration of the orbit was performed under general anesthesia. The displaced bone fragment was elevated and repositioned below the slastic implant. Diplopia continued in all directions of gaze, although the impairment of depression was reduced postoperatively. A residual left hypertropia of 10 prism diopters and exotropia of 10 prism diopters was present in primary position 1 month after surgery, though there were no enopthalmos or worsening of hypesthesia. Repeated CT revealed the muscle avulsion of inferior rectus at the lateral portion of the belly. The avulsion of a small segment of the inferior rectus and its herniation into maxillary sinus in more posterior views was detected by review of the preoperative images. Muscle avulsion should be considered in the management of orbital fracture if orbital tissue entrapment and nerve paresis are excluded as causes of reduction in ocular motility. A thorough review of the imaging studies for possible muscle injury is required before surgery in all cases of orbital fracture. PMID:22551369

  9. Current concepts on the management of orbital blow-out fractures.

    PubMed

    Koornneef, L

    1982-09-01

    Surgical versus nonsurgical treatment of orbital blow-out fractures has been controversial in the past. In the 1950s it was advocated that all blow-out fractures be treated surgically based on the conception that extraocular muscles were blown out and trapped in the fracture hole, causing double vision and enophthalmos. Gradually, however, a shift to a more conservative approach occurred, probably because of the complications of surgery, the disappointing results in improvement of motility and enophthalmos, and the growing evidence of spontaneous improvement of double vision. This article analyzes the literature chronologically and blends this analysis with the results of a new anatomical approach to the human orbit. New theories on the mechanism of blow-out fractures are postulated. No longer is entrapment of muslces in a blow-out fracture held responsible for the severe motility problems; rather it is viewed as caused by a dysfunction of the entire motility apparatus in the fracture region. Consequently, conventional surgical treatment, repairing the orbital floor only, seems to have lost its theoretical foundation and a conservative approach is advocated until microsurgical techniques become more readily avaliable to treat the sequelae of blow-out fractures at their origin. PMID:7137815

  10. Size effect in the tensile fracture of single-walled carbon nanotubes with defects

    NASA Astrophysics Data System (ADS)

    Yang, M.; Koutsos, V.; Zaiser, M.

    2007-04-01

    Molecular simulation is used to determine the fracture strength of single-walled carbon nanotubes (SWNT) containing different concentrations of randomly distributed point defects. The results are analysed using Weibull statistics, and the dependence of the statistical distribution of fracture strengths on defect concentration is established. Arguments from extreme order statistics are then used to formulate a relationship between the length of SWNT and their fracture strength. The results of this investigation help to explain the large differences between SWNT fracture strengths measured in experiments (13-52 GPa) and those obtained from theoretical calculations assuming defect-free nanotubes (~185 GPa).

  11. Orbital wall infarction mimicking periorbital cellulitis in a patient with sickle cell disease.

    PubMed

    Ozkavukcu, Esra; Fitoz, Suat; Yagmurlu, Banu; Ciftci, Ergin; Erden, Ilhan; Ertem, Mehmet

    2007-04-01

    Orbital wall infarction and subperiosteal haematomas are unusual manifestations of sickling disorders. Here we report an 11-year-old girl with sickle cell anaemia having multiple skull infarctions including the orbital bony structures associated with subperiosteal haematomas. The diagnosis was made by MRI, which showed bone marrow changes and associated haemorrhagic collections. The patient was successfully managed without surgical intervention. PMID:17297619

  12. Preliminary studies of water seepage through rough-walled fractures

    SciTech Connect

    Geller, J.T.; Su, G.; Pruess, K.

    1996-07-01

    For groundwater aquifers in fractured rock, fractures play a significant role in the transport of water and contaminants through the unsaturated zone to the groundwater table. Fractures can provide preferential flow paths for infiltrating liquids that dramatically accelerate contaminant transport compared to predictions based upon spatially uniform infiltration. The actual liquid distribution during infiltration determines the contact area between the flowing water and rock, and liquid residence time, which in turn affects the potential for rock-water and rock-solute interaction, as well as mass transfer between liquid and gas phases. This report summarizes flow- visualization experiments of water percolation through transparent replicas of a natural rock fracture. We have focused on phenomenological and exploratory experiments that can lead to a conceptual model which incorporates the important physical mechanisms that control flow.

  13. Infraorbital Nerve Block for Isolated Orbital Floor Fractures Repair: Review of 135 Consecutive Cases

    PubMed Central

    Spinelli, Giuseppe; Rocchetta, Davide; Carnevali, Giulia; Valente, Domenico; Conti, Marco

    2014-01-01

    Background: Orbital blowout fractures can be managed by several surgical specialties including plastic and maxillofacial surgery, otolaryngology, and ophthalmology. Recommendations for surgical fracture repair depend on a combination of clinical and imaging studies to evaluate muscle/nerve entrapment and periorbital tissue herniation. Methods: The aim of this study was to verify the applicability of regional anesthesia when repairing orbital floor fractures. A retrospective chart review was performed for isolated orbital floor fractures treated at the Department of Maxillofacial Surgery in Florence between May 2011 and July 2012. The study included 135 patients who met the inclusion criteria: 96 subjects were male (71%) and 39 were female (29%). The mean age was 45.3 years, ranging from 16 to 77 years. Results: The results revealed that isolated anterior orbital floor fractures can be safely repaired under regional and local anesthesia. Regional and local anesthesia should be combined with intravenous sedation when the fracture involves the posterior floor. The surgical outcome was comparable to the outcome achieved under general anesthesia. There was a lower rate of surgical revisions due to concealed malposition or entrapment of the inferior rectus muscle (19% vs 22%). However, this result was not statistically significant (P > 0.05). Conclusions: There are several advantages to surgically repairing isolated orbital floor fractures under regional and local anesthesia that include the following: surgeons can check the surgical outcome (enophthalmos and extrinsic ocular muscles function) intraoperatively, thereby reducing the reoperation rate; patient discomfort due to general anesthesia is eliminated; and the hospital stay is reduced, thus decreasing overall healthcare costs. PMID:25289294

  14. Influence of remaining dentin wall thickness on the fracture strength of endodontically treated tooth

    PubMed Central

    Haralur, Satheesh B.; Al-Qahtani, Ali Saad; Al-Qarni, Marie Mohammed; Al-Homrany, Rami Mohammed; Aboalkhair, Ayyob Ehsan

    2016-01-01

    Background: Remaining dentin wall thickness may influence the fracture resistance of tooth. Aims: To investigate the effect of various coronal dentin wall widths on the fracture strength of root canal treated teeth. Materials and Methods: Fifty recently extracted single canal mandibular premolars were used for the study. Ten unrestored teeth were used as control (Group 1); remaining teeth were root canal treated and divided into four groups (n = 10). The Groups 2a, 2b and 3a, 3b were having 2.5 mm, 1.5 mm remaining dentin with and without post, respectively. The samples fracture resistance was tested under the universal testing machine. The data were analyzed with one-way ANOVA and post-hoc Tukey test for comparative evaluation. Results: The mean fracture strength observed in Group 1 was (29.75 Mpa) followed by Group 2a (28.97 Mpa), Group 2b (27.70 Mpa), Group 3a (23.39 Mpa), and Group 3b (16.38 Mpa). There was no statistically significant difference between control and Groups 2a and 2b with P > 0.05. The post contributed significantly for fracture resistance in Group 3a. Conclusion: The endodontic post is not required in root canal treated teeth >2.5 mm coronal dentin wall width while the post is essential for a tooth with <1.5 mm dentin wall width to improve fracture resistance. PMID:26957796

  15. A case of blowout fracture of the orbital floor in early childhood

    PubMed Central

    Sugamata, Akira; Yoshizawa, Naoki

    2015-01-01

    There are few reports of blowout fractures of the orbital floor in children younger than 5 years of age; in a search of the literature, we found only six reported cases which revealed the exact age, correct diagnosis, and treatment. We herein report the case of a 3-year-old boy with a blowout fracture of the orbital floor. Computed tomography showed a pure blowout fracture of the left orbital floor with a slight dislocation of the orbital contents. The patient was treated conservatively due to the absence of abnormal limitation of eye movement or enophthalmos. The patient did not develop any complications that necessitated later surgical intervention. Computed tomography at 6 months after the injury showed the regeneration of the orbital floor in the area of the fracture and no abnormalities in the left maxillary sinus. We herein present our case and the details of six other cases reported in the literature, and discuss their etiology, diagnosis, and treatment methods. PMID:26251631

  16. A case of blowout fracture of the orbital floor in early childhood.

    PubMed

    Sugamata, Akira; Yoshizawa, Naoki

    2015-01-01

    There are few reports of blowout fractures of the orbital floor in children younger than 5 years of age; in a search of the literature, we found only six reported cases which revealed the exact age, correct diagnosis, and treatment. We herein report the case of a 3-year-old boy with a blowout fracture of the orbital floor. Computed tomography showed a pure blowout fracture of the left orbital floor with a slight dislocation of the orbital contents. The patient was treated conservatively due to the absence of abnormal limitation of eye movement or enophthalmos. The patient did not develop any complications that necessitated later surgical intervention. Computed tomography at 6 months after the injury showed the regeneration of the orbital floor in the area of the fracture and no abnormalities in the left maxillary sinus. We herein present our case and the details of six other cases reported in the literature, and discuss their etiology, diagnosis, and treatment methods. PMID:26251631

  17. Pressure wall hole size and maximum tip-to-tip crack length following orbital debris penetration

    NASA Technical Reports Server (NTRS)

    Schonberg, William P.

    1996-01-01

    The threat of damage from high speed meteoroid and orbital debris particle impacts has become a significant design consideration in the development and construction of long duration earth-orbiting spacecraft. Historically, significant amounts of resources have been devoted to developing shielding for such structures as a means of reducing the penetration potential of high speed on-orbit impacts. These efforts have typically focused on simply whether or not the inner (or 'pressure') walls of candidate multi-wall structural systems would be perforated. Only recently the nature and extent of pressure wall penetration damage have begun to be explored. This report presents the results of a study whose objective was to characterize the hole formation and cracking phenomena associated with the penetration of the multi-wall systems being considered for the International Space Station Alpha (ISSA).

  18. How reactive fluids alter fracture walls and affect shale-matrix accessibility

    NASA Astrophysics Data System (ADS)

    Fitts, J. P.; Deng, H.; Peters, C. A.

    2014-12-01

    Predictions of mass transfer across fracture boundaries and fluid flow in fracture networks provide fundamental inputs into risk and life cycle assessments of geologic energy technologies including oil and gas extraction, geothermal energy systems and geologic CO2 storage. However, major knowledge gaps exist due to the lack of experimental observations of how reactive fluids alter the pore structures and accessible surface area within fracture boundaries that control the mass transfer of organics, metals and salts, and influence fluid flow within the fracture. To investigate the fracture and rock matrix properties governing fracture boundary alteration, we developed a new flow-through cell that enables time-dependent 2D x-ray imaging of mineral dissolution and/or precipitation at a fracture surface. The parallel plate design provides an idealized fracture geometry to investigate the relationship between flow rate, reaction rate, and mineral spatial heterogeneity and variation. In the flow-cell, a carbonate-rich sample of Eagle Ford shale was reacted with acidified brine. The extent and rate of mineral dissolution were correlated with calcite abundance relative to less soluble silicate minerals. Three-dimensional x-ray tomography of the reacted fracture wall shows how calcite dissolution left behind a porous network of silicate minerals. And while this silicate network essentially preserved the location of the initial fracture wall, the pore network structures within the fracture boundary were dramatically altered, such that the accessible surface area of matrix components increased significantly. In a second set of experiments with a limestone specimen, however, the extent of dissolution and retreat of the fracture wall was not strictly correlated with the occurrence of calcite. Instead, the pattern and extent of dissolution suggested secondary causes such as calcite morphology, the presence of argillaceous minerals and other diagenetic features. Our experiments

  19. Diplopia of pediatric orbital blowout fractures: a retrospective study of 83 patients classified by age groups.

    PubMed

    Su, Yun; Shen, Qin; Lin, Ming; Fan, Xianqun

    2015-01-01

    Orbital blowout fractures are relatively rare in patients under 18 years of age, but may lead to serious complications. We conducted this retrospective study to evaluate diplopia, clinical characteristics, and postoperative results in cases of orbital blowout fractures in the pediatric population. Eighty-three patients, all less than 18 years old, with orbital blowout fractures, were divided into 3 groups by age: 0 to 6 years old, 7 to 12 years old, and 13 to 18 years old. The cause of injury, fracture locations, diplopia grades, ocular motility restrictions, enophthalmos, and postoperative results were reviewed from their records. Chi-square tests, Fisher's exact analyses, analyses of variance, and logistic regressions were performed to determine characteristics associated with diplopia, and to identify factors related to residual diplopia in pediatric patients. The most common causes of injuries were traffic accidents in the 0 to 6 years old group, normal daily activities in the 7 to 12 years old group, and assaults in the 13 to 18 years old group. Floor fractures were the most common location in both the 0 to 6- and 7 to 12 years old groups, and medial-floor fractures were the most common location in the 13 to 18 years old group. The occurrence of preoperative diplopia was related to ocular motility restriction and enophthalmos, but not with the age group, the gender, the cause of injury, or the fracture locations. The time interval from injury to surgery was significant in the outcome of postoperative diplopia (P < 0.01). A statistical difference was also found in the recovery time from diplopia among the 3 age groups (P < 0.01). The characteristics of orbital blowout fracture varied among the different age groups. It was related to 2 factors, the cause of injury and fracture locations, which probably resulted from structural growth changes and differences in daily habits. Children had a slower recovery from orbital fractures, and the younger the

  20. Diplopia of Pediatric Orbital Blowout Fractures: A Retrospective Study of 83 Patients Classified by Age Groups

    PubMed Central

    Su, Yun; Shen, Qin; Lin, Ming; Fan, Xianqun

    2015-01-01

    Abstract Orbital blowout fractures are relatively rare in patients under 18 years of age, but may lead to serious complications. We conducted this retrospective study to evaluate diplopia, clinical characteristics, and postoperative results in cases of orbital blowout fractures in the pediatric population. Eighty-three patients, all less than 18 years old, with orbital blowout fractures, were divided into 3 groups by age: 0 to 6 years old, 7 to 12 years old, and 13 to 18 years old. The cause of injury, fracture locations, diplopia grades, ocular motility restrictions, enophthalmos, and postoperative results were reviewed from their records. Chi-square tests, Fisher's exact analyses, analyses of variance, and logistic regressions were performed to determine characteristics associated with diplopia, and to identify factors related to residual diplopia in pediatric patients. The most common causes of injuries were traffic accidents in the 0 to 6 years old group, normal daily activities in the 7 to 12 years old group, and assaults in the 13 to 18 years old group. Floor fractures were the most common location in both the 0 to 6- and 7 to 12 years old groups, and medial-floor fractures were the most common location in the 13 to 18 years old group. The occurrence of preoperative diplopia was related to ocular motility restriction and enophthalmos, but not with the age group, the gender, the cause of injury, or the fracture locations. The time interval from injury to surgery was significant in the outcome of postoperative diplopia (P < 0.01). A statistical difference was also found in the recovery time from diplopia among the 3 age groups (P < 0.01). The characteristics of orbital blowout fracture varied among the different age groups. It was related to 2 factors, the cause of injury and fracture locations, which probably resulted from structural growth changes and differences in daily habits. Children had a slower recovery from orbital fractures, and the younger

  1. Nonlinear fracture mechanics-based analysis of thin wall cylinders

    NASA Technical Reports Server (NTRS)

    Brust, Frederick W.; Leis, Brian N.; Forte, Thomas P.

    1994-01-01

    This paper presents a simple analysis technique to predict the crack initiation, growth, and rupture of large-radius, R, to thickness, t, ratio (thin wall) cylinders. The method is formulated to deal both with stable tearing as well as fatigue mechanisms in applications to both surface and through-wall axial cracks, including interacting surface cracks. The method can also account for time-dependent effects. Validation of the model is provided by comparisons of predictions to more than forty full scale experiments of thin wall cylinders pressurized to failure.

  2. Acoustic apparatus and method for detecting borhole wall discontinuities such as vertical fractures

    SciTech Connect

    Havira, R.M.; Seeman, B.

    1989-12-05

    This patent describes an acoustic investigation method for detecting discontinuities in a wall of a borehold penetrating an earth formation. It comprises: directing from inside the borehole pulses of acoustic energy each at beam forming frequencies towards the borehold wall with orientations of the beams selected to preferentially enhance the excitation of transverse acoustic waves traveling away from the borehole wall segments in directions determined by the angle of incidence of the acoustic beams upon the borehole wall segment, while substantially maintaining the beam orientations, varying the direction which the acoustic beams are incident upon the borehole wall segments to correspondingly vary the directions which the transverse waves travel from the borehole wall segments; detecting acoustic reflections produced by the transverse waves when these are incident upon a discontinuity in the borehole wall; deriving fracture signals representative of the presence of a the discontinuity from the detected acoustic reflections; and recording the derived signals.

  3. Acoustic and optical borehole-wall imaging for fractured-rock aquifer studies

    USGS Publications Warehouse

    Williams, J.H.; Johnson, C.D.

    2004-01-01

    Imaging with acoustic and optical televiewers results in continuous and oriented 360?? views of the borehole wall from which the character, relation, and orientation of lithologic and structural planar features can be defined for studies of fractured-rock aquifers. Fractures are more clearly defined under a wider range of conditions on acoustic images than on optical images including dark-colored rocks, cloudy borehole water, and coated borehole walls. However, optical images allow for the direct viewing of the character of and relation between lithology, fractures, foliation, and bedding. The most powerful approach is the combined application of acoustic and optical imaging with integrated interpretation. Imaging of the borehole wall provides information useful for the collection and interpretation of flowmeter and other geophysical logs, core samples, and hydraulic and water-quality data from packer testing and monitoring. ?? 2003 Elsevier B.V. All rights reserved.

  4. The isolated orbital floor fracture from a transconjunctival or subciliary perspective-A standardized anthropometric evaluation

    PubMed Central

    Djedovic, Gabriel; Peisker, Andre; Wohlrath, Rene; Rieger, Ulrich; Guentsch, Arndt; Gomez-Dammeier, Marta; Schultze-Mosgau, Stefan

    2016-01-01

    Background The influence of orbital fractures and their repair on the rate of deformities of the lower eyelid is an ongoing source of discussion in the literature. Most of the present studies include isolated blowout as well as combined orbital fractures. Material and Methods We present a retrospective evaluation of a series of 100 patients after isolated blowout fracture repair using reference anthropometric data on standardized photographs. Analysis included eye fissure width and height, lid sulcus height, upper lid height, upper and lower iris coverage, position of cornea to palpebra inferior, canthal tilt, scleral show, ectropion and entropion. It was clearly distinguished between operated and contralateral eyelid, whether a transconjunctival or a subciliary approach was performed and amount of fracture. Our main interests were changes of the aforementioned parameters with regards to eyelid deformities. Results Surgery per se did not significantly influence eyelid deformities. However, the surgical approach selected significantly affected eye fissure index, lower iris coverage and rate of scleral show, indicating retraction of the lower eyelid. Conclusions The standardized measurements described here are accurate and objective to evaluate postoperative results. The subciliary approach included the highest risk of lower lid retraction as compared to transconjunctival approaches. Key words:Transconjunctical approach, subciliary approach, orbital floor fracture. PMID:26595833

  5. Mass removal of chlorinated ethenes from rough-walled fractures using permanganate

    NASA Astrophysics Data System (ADS)

    Tunnicliffe, B. S.; Thomson, N. R.

    2004-11-01

    In situ chemical oxidation (ISCO) employing permanganate is an emerging technology that has been successful at enhancing mass removal from DNAPL source zones in unconsolidated media at the pilot-scale. The focus of this study was to evaluate the applicability of flushing a permanganate solution across two single vertical fractures in a laboratory environment to remove free phase DNAPL. The fracture experiments were designed to represent a portion of a larger fractured aquifer system impacted by a near-surface DNAPL spill over a shallow fractured rock aquifer. Each fracture was characterized by hydraulic and tracer tests, and the aperture field for one of the fractures was mapped using a co-ordinate measurement machine. Following DNAPL emplacement, a series of water and permanganate flushes were performed. To support observations from the fracture experiments, a set of batch experiments was conducted. The data from both fracture experiments showed that the post-oxidation effluent concentration was not impacted by the oxidant flush; however, changes in the aperture distribution, flow field, and flow rate were observed. These changes resulted in a significant decrease to the mass loading from the fractures, and were attributed to the build-up of oxidation by-products (manganese oxides and carbon dioxide) within the fracture which was corroborated by the batch experiment data and visual examination of the walls of one fracture. These results provide insight into the potential impact that a permanganate solution and oxidation by-products can have on the aperture distribution within a fracture and on DNAPL mass transfer rates. A permanganate flush or injection completed within a fractured rock aquifer may lead to the development of an insoluble product adjacent to the DNAPL which results in the reduction or complete elimination of advective regions near the DNAPL and reduces mass transfer rates. This outcome would have significant implications on the plume generating

  6. Spin-orbit coupling and the static polarizability of single-wall carbon nanotubes

    SciTech Connect

    Diniz, Ginetom S. Ulloa, Sergio E.

    2014-07-14

    We calculate the static longitudinal polarizability of single-wall carbon tubes in the long wavelength limit taking into account spin-orbit effects. We use a four-orbital orthogonal tight-binding formalism to describe the electronic states and the random phase approximation to calculate the dielectric function. We study the role of both the Rashba as well as the intrinsic spin-orbit interactions on the longitudinal dielectric response, i.e., when the probing electric field is parallel to the nanotube axis. The spin-orbit interaction modifies the nanotube electronic band dispersions, which may especially result in a small gap opening in otherwise metallic tubes. The bandgap size and state features, the result of competition between Rashba and intrinsic spin-orbit interactions, result in drastic changes in the longitudinal static polarizability of the system. We discuss results for different nanotube types and the dependence on nanotube radius and spin-orbit couplings.

  7. Treatment of orbital blowout fracture using porous polyethylene with embedded titanium.

    PubMed

    Qian, Zhuyun; Zhuang, Ai; Lin, Ming; Li, Zhengkang; Ge, Shengfang; Fan, Xianqun

    2015-03-01

    The study was performed to evaluate the effectiveness and safety of porous polyethylene with embedded titanium in the repair of orbital blowout fracture. The study was designed as a prospective case series. Patients who were diagnosed with orbital blowout fracture from May 2012 to March 2013 were included in the study. A composite material of porous polyethylene and titanium mesh was used. Orbital volumes before and after surgery were measured, and the results of diplopia and ocular movement were recorded. The occurrence of diplopia was grouped and compared according to the time interval between injury and surgery. The incidence of other complications was also recorded. A total of 26 patients were involved in the study. The minimal follow-up time was 12 months. All surgeries were performed uneventfully. The orbital volume significantly decreased after the surgery, and the remission rate and the elimination rate of diplopia in 12 months were 85.7% and 47.6%, respectively. Postoperative diplopia was correlated with the time interval between injury and surgery. One patient presented with undercorrection of enophthalmos, and another patient presented with acute aggravation of diplopia and exophthalmos after surgery, which was resolved with treatment. In conclusion, porous polyethylene with embedded titanium was effective and safe in the repair of orbital blowout fracture, and studies with more subjects and longer follow-up period are recommended in future studies. PMID:25699530

  8. Estimation of DNAPL dissolution stage from aqueous phase concentrations in rough-walled fractures

    NASA Astrophysics Data System (ADS)

    Kim, Hyun Jung; Yeo, In Wook

    2013-04-01

    Contamination of dense non-aqueous phase liquids (DNAPLs) poses a serious environmental problem. Because of higher density of DNAPLs than water, they migrate downward through water table, finally entering the fractures where they tend to be trapped as residual phases by capillary resistance of smaller apertures. It has been reported that many industrial complexes in Korea, placed on the fractured bedrock, have been contaminated by DNAPLs. Due to the way DNAPLs are discontinuously in small quantity at unfixed spots even within the site in Korea, DNAPL sources tend to exist scattered in the subsurface environment and are almost impossible to locate, especially in fractured bedrocks. Furthermore, DNAPL contamination is often found after a long period of time has passed since the contamination started. These characteristics of DNAPL contamination make it very difficult to infer DNAPL source configuration, which consequently leads to considerable uncertainties about the effective management and remediation of DNAPL contaminated site. This study aims to figure out DNAPL source zone configuration in rough-walled fractures, in particular dissolution stage of DNAPL, from downgradient aqueous phase concentrations. Interpretation and estimation of the dissolution stage are very important for the design and required time of site remediation. Numerical works have been systematically conducted with a single rough-walled fracture to investigate the interrelationship between DNAPL architecture and downgradient aqueous-phase contaminant concentrations. The finite element code was programmed for fluid flow and solute transport through a rough-walled fracture, which was incorporated with the dissolution kinetics. DNAPL is emplaced as residual phase in a rough-walled fracture with variable apertures measured from a real rock fracture, and the mass transfer is allowed to take place at the interface between DNAPL and flowing groundwater. The aqueous phase contaminant transports with

  9. Tail shortening with developing eddies in a rough-walled rock fracture

    NASA Astrophysics Data System (ADS)

    Lee, Seung Hyun; Yeo, In Wook; Lee, Kang-Kun; Detwiler, Russell L.

    2015-08-01

    Understanding fluid flow and solute transport in rough-walled fractures is important in many problems such as geological storage of CO2 and siting of radioactive waste repositories. The first microscopic observation of fluid flow and solute transport through a rough-walled fracture was made to assess the evolution of eddies and their effect on non-Fickian tailing. A noteworthy phenomenon was observed that as the eddy grew, the particles were initially caught in and swirled around within eddies, and then cast back into main flow channel, which reduced tailing. This differs from the conventional conceptual model, which presumes a distinct separation between mobile and immobile zones. Fluid flow and solute transport modeling within the 3-D fracture confirmed tail shortening due to mass transfer by advective paths between the eddies and the main flow channel, as opposed to previous 2-D numerical studies that showed increased tailing with growing eddies.

  10. Semi-automatic analysis of rock fracture orientations from borehole wall images

    SciTech Connect

    Thapa, B.B.; Hughett, P.; Karasaki, K.

    1997-01-01

    The authors develop a semiautomatic method of identifying rock fractures and analyzing their orientations from digital images of borehole walls. This method is based on an algorithm related to the Hough transform which is modified to find sinusoidal rather than linear patterns. The algorithm uses the high-intensity contrast between the fracture aperture and the rock wall, as well as the sinusoidal trajectory defined by the intersection of the borehole and the fracture. The analysis rate of the algorithm itself is independent of fracture contrast and network complexity. The method has successfully identified fractures both in test cases containing several fractures in a noisy background and in real borehole images. The analysis rate was 0.3--1.2 minutes/m of input data, compared to an average of 12 minutes/m using an existing interactive method. An automatic version under development should open new possibilities for site characterization, such as real-time exploration and analysis of tunnel stability and support requirements as construction proceeds.

  11. Clinical and surgical implications regarding morphometric variations of the medial wall of the orbit in relation to age and gender.

    PubMed

    Morales-Avalos, Rodolfo; Santos-Martínez, Arlette Gabriela; Ávalos-Fernández, Cesia Gisela; Mohamed-Noriega, Karim; Sánchez-Mejorada, Gabriela; Montemayor-Alatorre, Adolfo; Martínez-Fernández, David A; Espinosa-Uribe, Abraham G; Mohamed-Noriega, Jibran; Cuervo-Lozano, Edgar E; Mohamed-Hamsho, Jesús; Quiroga-García, Oscar; Lugo-Guillen, Roberto A; Guzmán-López, Santos; Elizondo-Omaña, Rodrigo E

    2016-09-01

    The ethmoidal foramens are located on the medial wall of the orbit and are key reference points for intraoperative orientation. Detailed knowledge of the anatomy, bony landmarks and morphometric characteristics of the medial wall of the orbit is essential for various surgical procedures. The aim of this study was to determine the morphometric variations in the medial wall of the orbit and establish significant variations regarding age and gender. A total of 110 orbits were analyzed and subdivided by age (over or under 40 years) and gender. The distances of the medial wall of the orbit between the anterior lacrimal crest, the ethmoidal foramen, the optic canal and the interforamina were determined. Safe surgical areas were sought. Statistical tests were used to determine the differences between groups. In men, there is a safe surgical area proximal to the anterior and posterior ethmoidal foramen. In women, this area is in the posterior third of the medial wall of the orbit between the posterior ethmoidal foramen and the optic canal. Regarding variation according to age, the results of this study suggested that the anteroposterior diameter of the medial wall increases with age. This study showed that the anteroposterior total length of the medial orbit wall is similar between genders of similar age, increases with age, and has significant variations in the distances between the various structures that make up the medial orbit wall with regard to gender and age. PMID:26683469

  12. The submuscular sliding plate technique for acetabular posterior wall fractures extending to the acetabular roof.

    PubMed

    Kim, J J; Kim, J W; Oh, H K

    2014-12-01

    There is extension of the Kocher-Langenbeck approach using trochanteric osteotomy for posterior wall fracture extending to acetabular roof, but it exposes to complications such as nonunion, breakage, and heterotopic ossification. The current study introduces a submuscular sliding plate technique. We retrospectively analyzed 13 patients treated with this technique. It is based on conventional method for posterior wall fracture. After reduction of roof fragment with direct visualization, a pre-contoured plate was passed through a submuscular tunnel under the gluteus medius and minimus. A small split incision was performed on the muscles, and screws were inserted with a triple trocar complex safely under fluoroscopic imaging. All patients had fracture union without complications. X-rays results showed anatomical reduction in 10 cases and imperfect reduction in 3 cases. Our results were satisfactory, particularly without heterotopic ossifications despite no prophylactic regimen of NSAID was applied and no neurological complications, so we believe that this technique is a good option for posterior wall fractures extending to the acetabular roof. PMID:25453921

  13. Is Delayed Release of Superior Oblique Muscle Entrapment in Orbital Roof Fracture Worth Correcting?

    PubMed

    Sharma, Rohit; Muralidharan, Chiyyarath Gopalan; Roy, Indranil Deb; Janjani, Lalit

    2016-07-01

    Acquired Brown's syndrome is a rare entity. Delay in treatment can cause fibrosis or scarring with questionable prognosis of vertical diplopia. To the best of the knowledge of the authors the present case of 22-year-old male is the first in existing literature where delayed release of superior oblique muscle entrapment in orbital roof fracture was found to be an effective technique. PMID:27391521

  14. Transmission electron microscopy observations of fracture of single-wall carbon nanotubes under axial tension

    NASA Astrophysics Data System (ADS)

    Lourie, O.; Wagner, H. D.

    1998-12-01

    Well-aligned bundles of single-wall carbon nanotubes under tensile stresses were observed to fracture in real-time by transmission electron microscopy. The expansion of elliptical holes in the polymer matrix results in a tensile force in bridging nanotubes. The polymer matrix at both ends of the bundles deforms extensively under the tension force, and fracture of the nanotubes occurs in tension within the polymer hole region rather than in shear within the gripping polymer region at the ends of the bundles. This provides evidence of significant polymer-nanotube wetting and interfacial adhesion.

  15. High Antiferromagnetic Domain Wall Velocity Induced by Néel Spin-Orbit Torques

    NASA Astrophysics Data System (ADS)

    Gomonay, O.; Jungwirth, T.; Sinova, J.

    2016-07-01

    We demonstrate the possibility to drive an antiferromagnetic domain wall at high velocities by fieldlike Néel spin-orbit torques. Such torques arise from current-induced local fields that alternate their orientation on each sublattice of the antiferromagnet and whose orientation depends primarily on the current direction, giving them their fieldlike character. The domain wall velocities that can be achieved by this mechanism are 2 orders of magnitude greater than the ones in ferromagnets. This arises from the efficiency of the staggered spin-orbit fields to couple to the order parameter and from the exchange-enhanced phenomena in antiferromagnetic texture dynamics, which leads to a low domain wall effective mass and the absence of a Walker breakdown limit. In addition, because of its nature, the staggered spin-orbit field can lift the degeneracy between two 180° rotated states in a collinear antiferromagnet, and it provides a force that can move such walls and control the switching of the states.

  16. High Antiferromagnetic Domain Wall Velocity Induced by Néel Spin-Orbit Torques.

    PubMed

    Gomonay, O; Jungwirth, T; Sinova, J

    2016-07-01

    We demonstrate the possibility to drive an antiferromagnetic domain wall at high velocities by fieldlike Néel spin-orbit torques. Such torques arise from current-induced local fields that alternate their orientation on each sublattice of the antiferromagnet and whose orientation depends primarily on the current direction, giving them their fieldlike character. The domain wall velocities that can be achieved by this mechanism are 2 orders of magnitude greater than the ones in ferromagnets. This arises from the efficiency of the staggered spin-orbit fields to couple to the order parameter and from the exchange-enhanced phenomena in antiferromagnetic texture dynamics, which leads to a low domain wall effective mass and the absence of a Walker breakdown limit. In addition, because of its nature, the staggered spin-orbit field can lift the degeneracy between two 180° rotated states in a collinear antiferromagnet, and it provides a force that can move such walls and control the switching of the states. PMID:27419586

  17. Fracture toughness of irradiated candidate materials for ITER first wall/blanket structures: Summary report

    SciTech Connect

    Alexander, D.J.; Pawel, J.E.; Grossbeck, M.L.; Rowcliffe, A.F.

    1996-04-01

    Disk compact specimens of candidate materials for first wall/blanket structures in ITER have been irradiated to damage levels of about 3 dpa at nominal irradiation temperatures of either 90 250{degrees}C. These specimens have been tested over a temperature range from 20 to 250{degrees}C to determine J-integral values and tearing moduli. The results show that irradiation at these temperatures reduces the fracture toughness of austenic stainless steels, but the toughness remains quite high. The toughness decreases as the temperature increases. Irradiation at 250{degrees}C is more damaging that at 90{degrees}C, causing larger decreases in the fracture toughness. The ferritic-martensitic steels HT-9 and F82H show significantly greater reductions in fracture toughness that the austenitic stainless steels.

  18. Influence of kinesiologic tape on postoperative swelling, pain and trismus after zygomatico-orbital fractures.

    PubMed

    Ristow, Oliver; Pautke, Christoph; Victoria Kehl; Koerdt, Steffen; Schwärzler, Katharina; Hahnefeld, Lilian; Hohlweg-Majert, Bettina

    2014-07-01

    Surgical treatment of zygomatico-orbital (ZO) fractures is a common procedure in maxillofacial surgery. Often accompanied by pain, trismus and swelling, postoperative morbidity is a major disadvantage, affecting patients' quality of life. The appliance of kinesiologic tape (KT) improves the blood and lymph flow, removing congestions of lymphatic fluid and haemorrhages. The aim of this study was to find out if the application of kinesiologic tape prevents or improves swelling, pain and trismus after zygomatico-orbital fracture surgery, improving patients' postoperative quality of life. A total of 30 patients were assigned for treatment of zygomatico-orbital fractures and were randomly divided into treatment either with or without kinesiologic tape. Tape was applied directly after surgery and maintained for at least 5 days postoperatively. Facial swelling was quantified using a five-line measurement at six specific time points. Pain and degree of mouth opening was measured. Patient's subjective feeling and satisfaction was queried. The results of this study show that application of kinesiologic tape after zygomatico-orbital surgery significantly reduced the incidence of swelling with an earlier swelling maximum, and decreased the maximum turgidity for more than 60% during the first 2 days after surgery. Although, kinesiologic tape has no significant influence on pain control and trismus, mouth opening increased earlier after operation in the kinesiologic tape group compared to the no-kinesiologic tape group. Furthermore, patients with kinesiologic tape felt significantly lower morbidity than those without kinesiologic tape. Therefore kinesiologic tape is a promising, simple, less traumatic, economical approach, which is free from adverse reaction and improves patients' quality of life. PMID:23830769

  19. Miniaturized fracture tests for thin-walled tubular SiC specimens

    SciTech Connect

    Byun, Thak Sang; Lara-Curzio, Edgar; Lowden, Richard Andrew; Snead, Lance Lewis; Katoh, Yutai

    2007-01-01

    Two testing methods have been developed for miniaturized tubular specimens to evaluate the fracture stress of chemically vapor deposited (CVD) SiC coatings in nuclear fuel particles. In the first method hoop stress is applied to a thin-walled tubular specimen by internal pressurization using a polyurethane insert. The second method is a crushing technique, in which tubular specimen is fractured by diametrical compressive loading. Tubular SiC specimens with a wall thickness of about 100 {micro}m and inner diameters of about 0.9 mm (SiC-A) and 1 mm (SiC-B) were extracted from surrogate nuclear fuels and tested using the two test methods. Mean fracture stresses of 239, 263, and 283 MPa were measured for SiC-A and SiC-B by internal pressurization, and SiC-A by diametrical loading, respectively. In addition, size effects in the fracture stress were investigated using tubular alumina specimens with various sizes. A significant size effect was found in the experimental data and was also predicted by the effective area-based scaling method.

  20. Modeling gravity-driven fingering in rough-walled fractures using modified percolation theory

    SciTech Connect

    Glass, R.J.

    1992-12-31

    Pore scale invasion percolation theory is modified for imbibition of.wetting fluids into fractures. The effects of gravity, local aperture field geometry, and local in-plane air/water interfacial curvatureare included in the calculation of aperture filling potential which controls wetted structure growth within the fracture. The inclusion of gravity yields fingers oriented in the direction of the gravitational gradient. These fingers widen and tend to meander and branch more as the gravitational gradient decreases. In-plane interfacial curvature also greatly affects the wetted structure in both horizontal and nonhorizontal fractures causing the formation of macroscopic wetting fronts. The modified percolation model is used to simulate imbibition into an analogue rough-walled fracture where both fingering and horizontal imbibition experiments were previously conducted. Comparison of numerical and experimental results showed reasonably good agreement. This process oriented physical and numerical modeling is-a necessary step toward including gravity-driven fingering in models of flow and transport through unsaturated, fractured rock.

  1. Fracture Toughness Measurements and Assessment of Thin Walled Conduit Alloys in a Cicc Application

    NASA Astrophysics Data System (ADS)

    Walsh, R. P.; Han, K.; Toplosky, V. J.

    2008-03-01

    The Series-Connected Hybrid Magnets under construction at the NHMFL use Cable-in-Conduct-Conductor (CICC) technology. The 4 K mechanical properties of the conduit are extremely important to the performance and reliability of the magnets. We have measured tensile and fracture toughness of two candidate conduit alloys (Haynes 242 and modified 316LN) in various metallurgical states, with emphasis on the final state of production. To assess the material in its final production state, non-standard specimens are removed directly from the round-corner rectangular conduit and tested after exposure to a simulated Nb3Sn reaction heat treatment. Non-standard middle-tension (MT) fracture toughness specimens enable toughness evaluation of the base metal, welds and weld/base transitional region in the as-fabricated conduit with final dimensions not suitable for conventional fracture toughness specimens. Although fracture toughness tests of the thin walled conduit fail to meet ASTM test validity requirements they provide a qualitative evaluation and estimate of the fracture toughness of the conduit and the welds.

  2. FRACTURE TOUGHNESS MEASUREMENTS AND ASSESSMENT OF THIN WALLED CONDUIT ALLOYS IN A CICC APPLICATION

    SciTech Connect

    Walsh, R. P.; Han, K.; Toplosky, V. J.

    2008-03-03

    The Series-Connected Hybrid Magnets under construction at the NHMFL use Cable-in-Conduct-Conductor (CICC) technology. The 4 K mechanical properties of the conduit are extremely important to the performance and reliability of the magnets. We have measured tensile and fracture toughness of two candidate conduit alloys (Haynes 242 and modified 316LN) in various metallurgical states, with emphasis on the final state of production. To assess the material in its final production state, non-standard specimens are removed directly from the round-corner rectangular conduit and tested after exposure to a simulated Nb{sub 3}Sn reaction heat treatment. Non-standard middle-tension (MT) fracture toughness specimens enable toughness evaluation of the base metal, welds and weld/base transitional region in the as-fabricated conduit with final dimensions not suitable for conventional fracture toughness specimens. Although fracture toughness tests of the thin walled conduit fail to meet ASTM test validity requirements they provide a qualitative evaluation and estimate of the fracture toughness of the conduit and the welds.

  3. Orbital roof fracture and orbital cellulitis secondary to halo pin penetration: case report.

    PubMed

    Menon, K Venugopal; Al Rawi, Asif Esam; Taif, Sawsan; Al Ghafri, Khalifa; Mollahalli, Kishore Kumar

    2015-02-01

    Study Design Case report. Objective To report and discuss a rare complication after a patient was treated conservatively with a halo vest. Methods A 51-year-old man sustained a hangman's injury of the C2 vertebra following a motor vehicle collision. He was treated conservatively in a halo vest appliance and following mobilization was discharged from the hospital. Two weeks after discharge, the patient presented to the emergency department complaining of proptosis, ptosis, diplopia, and pin loosening. He was readmitted to the hospital, the halo vest was removed, and urgent imaging studies including computed tomography scan and magnetic resonance imaging were performed. They revealed that one of the halo pins had penetrated the orbital roof with active infection of the extraocular soft tissues. In consultation with the ophthalmologist, he was treated conservatively with antibiotics for 10 days. Results His ophthalmologic complaints resolved gradually and his eye returned to normal appearance and function. In the meantime, he was immobilized in a sterno-occipital mandibular immobilizer brace. Conclusion Though rare, penetrating injuries after cranial pin insertion can occur. Halo devices must be applied by, or under close supervision of, experienced personnel to avoid such complications, and halo vests should be reviewed frequently to detect such incidents early. PMID:25648519

  4. Epistaxis as the only initial symptom in pediatric naso-orbital-ethmoid fracture complicated with meningitis.

    PubMed

    Chou, Erh-Kang; Wu, Chao-I; Yu, Jack Chung-Kai; Chang, Sophia Chia-Ning

    2009-05-01

    Epistaxis is a frequent finding in patients with facial trauma. Herein, we report an unusual presentation of pediatric naso-orbital-ethmoid (NOE) fracture with epistaxis as the only initial symptom. The course of the patient's condition was later complicated by meningitis, related in part to the delay in diagnosis. A 3-year-old girl with preexisting upper respiratory symptoms was involved in a traffic accident, sustaining blunt trauma to the right side of her face. During the initial examination, only right-sided epistaxis was noted. Five days later, she developed febrile convulsion and was admitted to the intensive care unit with other signs of meningitis such as mental status change and neck stiffness. Her craniofacial computed tomographic scan showed a right-sided NOE fracture with minimal displacement and without dura tear. The cerebrospinal fluid culture grew Streptococcus pneumoniae, which may be due to ascending infection as a result of cribriform plate fracture. Intravenous antibiotic therapy was initiated with good response, and she was discharged from the hospital after 2 weeks. The presence of epistaxis and periorbital bruise, together with other symptoms and signs, helps in the identification of NOE and cribriform plate fracture. A high index of suspicion with repetitive computed tomographic scans is necessary to achieve correct early diagnosis. Parental antibiotic therapy is indicated if ascending cerebrospinal fluid infection develops. PMID:19461340

  5. Maxillofacial Fractures: Midface and Internal Orbit-Part II: Principles and Surgical Treatment.

    PubMed

    Mast, Gerson; Ehrenfeld, Michael; Cornelius, Carl-Peter; Tasman, Abel-Jan; Litschel, Ralph

    2015-08-01

    Current clinical assessment and imaging techniques were described in part 1, and this article presents a systematic review of the surgical treatment principles in the management of midface and internal orbit fractures from initial care to definitive treatment, including illustrative case examples. New developments enabled limited surgical approaches by standardization of osteosynthesis principles regarding three-dimensional buttress reconstruction, by newly developed individualized implants such as titanium meshes and, especially for complex fracture patterns, by critical assessment of anatomical reconstruction through intraoperative endoscopy, as well as intra- and postoperative imaging. Resorbable soft tissue anchors can be used both for ligament and soft tissue resuspension to reduce ptosis effects in the cheeks and nasolabial area and to achieve facial aesthetics similar to those prior to the injury. PMID:26372710

  6. Cosmic bubble and domain wall instabilities II: fracturing of colliding walls

    SciTech Connect

    Braden, Jonathan; Bond, J. Richard; Mersini-Houghton, Laura

    2015-08-26

    We study collisions between nearly planar domain walls including the effects of small initial nonplanar fluctuations. These perturbations represent the small fluctuations that must exist in a quantum treatment of the problem. In a previous paper, we demonstrated that at the linear level a subset of these fluctuations experience parametric amplification as a result of their coupling to the planar symmetric background. Here we study the full three-dimensional nonlinear dynamics using lattice simulations, including both the early time regime when the fluctuations are well described by linear perturbation theory as well as the subsequent stage of fully nonlinear evolution. We find that the nonplanar fluctuations have a dramatic effect on the overall evolution of the system. Specifically, once these fluctuations begin to interact nonlinearly the split into a planar symmetric part of the field and the nonplanar fluctuations loses its utility. At this point the colliding domain walls dissolve, with the endpoint of this being the creation of a population of oscillons in the collision region. The original (nearly) planar symmetry has been completely destroyed at this point and an accurate study of the system requires the full three-dimensional simulation.

  7. Blowout fracture-orbital floor reconstruction using costochondral cartilage causing pain, warping, and diplopia

    PubMed Central

    Balaji, S. M.

    2015-01-01

    Orbital floor reconstruction is the most challenging component in the midfacial trauma management. Most often owing to the complexity of the fractures, the floor reconstruction requires grafts or other substitutes. Literature reveals several sources of autogenous sources of such grafts. Though most of the grafts are well taken and gives an ideal result, at certain instances, owing to the complex nature of the graft, its biochemical nature, reaction to the grafting, biochemical response, a reactionary change may result at late stages. The aim of this manuscript is to present a rare instance of warping of a costochondral graft that was used as a part of the orbital floor reconstruction giving rise to an ophthalmic emergency. The situation was immediately diagnosed and successfully managed. The situation, structural, and biochemical mechanisms behind such a phenomenon are discussed. PMID:26981485

  8. Blowout fracture-orbital floor reconstruction using costochondral cartilage causing pain, warping, and diplopia.

    PubMed

    Balaji, S M

    2015-01-01

    Orbital floor reconstruction is the most challenging component in the midfacial trauma management. Most often owing to the complexity of the fractures, the floor reconstruction requires grafts or other substitutes. Literature reveals several sources of autogenous sources of such grafts. Though most of the grafts are well taken and gives an ideal result, at certain instances, owing to the complex nature of the graft, its biochemical nature, reaction to the grafting, biochemical response, a reactionary change may result at late stages. The aim of this manuscript is to present a rare instance of warping of a costochondral graft that was used as a part of the orbital floor reconstruction giving rise to an ophthalmic emergency. The situation was immediately diagnosed and successfully managed. The situation, structural, and biochemical mechanisms behind such a phenomenon are discussed. PMID:26981485

  9. Paediatric Orbital Fractures: The Importance of Regular Thorough Eye Assessment and Appropriate Referral

    PubMed Central

    Kassam, Karim; Rahim, Ishrat; Mills, Caroline

    2013-01-01

    The paediatric orbital fracture should always raise alarm bells to all clinicians working in an emergency department. A delay or failure in diagnosis and appropriate referral can result in rapidly developing and profound complications. We present a boy of childhood age who sustained trauma to his eye during a bicycle injury. Acceptance of the referral was based on no eye signs; however, on examination in our unit the eye had reduction in visual acuity, no pupillary reaction, and ophthalmoplegia. CT scan suggested bone impinging on the globe and the child was rushed to theatre for removal of the bony fragment. Postoperatively no improvement was noted and a diagnosis of traumatic optic neuropathy was made. An overview of factors complicating paediatric orbital injuries, their associated “red flags”, and appropriate referral are discussed in this short paper. PMID:24349804

  10. Paediatric orbital fractures: the importance of regular thorough eye assessment and appropriate referral.

    PubMed

    Kassam, Karim; Rahim, Ishrat; Mills, Caroline

    2013-01-01

    The paediatric orbital fracture should always raise alarm bells to all clinicians working in an emergency department. A delay or failure in diagnosis and appropriate referral can result in rapidly developing and profound complications. We present a boy of childhood age who sustained trauma to his eye during a bicycle injury. Acceptance of the referral was based on no eye signs; however, on examination in our unit the eye had reduction in visual acuity, no pupillary reaction, and ophthalmoplegia. CT scan suggested bone impinging on the globe and the child was rushed to theatre for removal of the bony fragment. Postoperatively no improvement was noted and a diagnosis of traumatic optic neuropathy was made. An overview of factors complicating paediatric orbital injuries, their associated "red flags", and appropriate referral are discussed in this short paper. PMID:24349804

  11. Fracture resistance of premolars with one remaining cavity wall restored using different techniques.

    PubMed

    Kivanç, Bagdagül Helvacioglu; Alaçam, Tayfun; Görgül, Güliz

    2010-05-01

    The aim of the study was to compare the fracture resistance of maxillary premolars with one remaining cavity wall restored using different post systems. Forty-eight maxillary premolars were endodontically treated and randomly assigned to four groups for postcore restoration. The first three test groups were restored with polyethylene woven fiber posts, custom-made glass fiber-reinforced composite posts, and titanium posts respectively. In the control Group 4, standardized cavities (3.5 x 1.5 mm) were prepared in the palatal canal entrance and filled with a resin composite. All the specimens were then restored with a resin composite crown seated on the post. Load was applied with a stainless steel ball (1 mm/min), and the failure modes of all specimens were evaluated. There were no significant differences in fracture resistance and failure mode among the different restorative materials (p>0.05). Within the limitations of this in vitro study, it was concluded that the presence and type of post did not influence the fracture load and failure mode of maxillary premolar teeth with one remaining cavity wall. PMID:20448409

  12. Wettability-dependent DNAPL migration in a rough-walled fracture

    NASA Astrophysics Data System (ADS)

    Lee, Hang-Bok; Yeo, In Wook; Ji, Sung-Hoon; Lee, Kang-Kun

    2010-04-01

    The effect of wettability on the migration of dense non-aqueous phase liquids (DNAPLs) through a rough-walled fracture was investigated. The migration characteristics of DNAPL were found to be strongly dependent on the wettability. For a fracture with a hydrophilic surface, DNAPL migrated through larger apertures as disconnected blobs when the groundwater flow regime was linear (Re = 1). However, for non hydrophilic surfaces DNAPL did not migrate in the same way as for the hydrophilic surface. The intermediate-wet surface, with a contact angle of ≈90°, makes gravity pressure dominant over the capillary pressure, resulting in the fastest DNAPL migration. DNAPL was retained on the hydrophobic fracture, where the capillary barrier of larger apertures forced the DNAPL to migrate through the smaller apertures. In the nonlinear flow regime of Re = 60, DNAPL generally migrated downward as a result of the inertial pressure of flowing water for all the wettability conditions, but the local downward migration paths were still determined by the capillary pressure, which resulted in the fastest and slowest migration on the hydrophilic and the hydrophobic fractures, respectively. This study implies that the hydrophilic and intermediate-wet surfaces will be favorable for DNAPL and oil recovery.

  13. Wettability-dependent DNAPL migration in a rough-walled fracture.

    PubMed

    Lee, Hang-Bok; Yeo, In Wook; Ji, Sung-Hoon; Lee, Kang-Kun

    2010-04-01

    The effect of wettability on the migration of dense non-aqueous phase liquids (DNAPLs) through a rough-walled fracture was investigated. The migration characteristics of DNAPL were found to be strongly dependent on the wettability. For a fracture with a hydrophilic surface, DNAPL migrated through larger apertures as disconnected blobs when the groundwater flow regime was linear (Re=1). However, for non hydrophilic surfaces DNAPL did not migrate in the same way as for the hydrophilic surface. The intermediate-wet surface, with a contact angle of approximately 90 degrees , makes gravity pressure dominant over the capillary pressure, resulting in the fastest DNAPL migration. DNAPL was retained on the hydrophobic fracture, where the capillary barrier of larger apertures forced the DNAPL to migrate through the smaller apertures. In the nonlinear flow regime of Re=60, DNAPL generally migrated downward as a result of the inertial pressure of flowing water for all the wettability conditions, but the local downward migration paths were still determined by the capillary pressure, which resulted in the fastest and slowest migration on the hydrophilic and the hydrophobic fractures, respectively. This study implies that the hydrophilic and intermediate-wet surfaces will be favorable for DNAPL and oil recovery. PMID:20110134

  14. Fracture toughness of irradiated candidate materials for ITER first wall/blanket structures

    SciTech Connect

    Alexander, D.J.; Pawel, J.E.; Grossbeck, M.L.; Rowcliffe, A.F.; Shiba, Kiyoyuki

    1994-12-31

    Disk compact specimens of candidate materials for first wall/blanket structures in ITER have been irradiated to damage levels of about 3 dpa at nominal irradiation temperatures of either 90 or 250{degrees}C. These specimens have been tested over a temperature range from 20 to 250{degrees}C to determine J-integral values and tearing moduli. The results show that irradiation at these temperatures reduces the fracture toughness of austenitic stainless steels, but the toughness remains quite high. The toughness decreases as the test temperature increases. Irradiation at 250{degrees}C is more damaging than at 90{degrees}C, causing larger decreases in the fracture toughness. Ferritic-martensitic steels are embrittled by the irradiation, and show the lowest toughness at room temperature.

  15. The stability of steady motion of magnetic domain wall: Role of higher-order spin-orbit torques

    SciTech Connect

    He, Peng-Bin Yan, Han; Cai, Meng-Qiu; Li, Zai-Dong

    2015-12-14

    The steady motion of magnetic domain wall driven by spin-orbit torques is investigated analytically in the heavy/ferromagnetic metal nanowires for three cases with a current transverse to the in-plane and perpendicular easy axis, and along the in-plane easy axis. By the stability analysis of Walker wall profile, we find that if including the higher-order spin-orbit torques, the Walker breakdown can be avoided in some parameter regions of spin-orbit torques with a current transverse to or along the in-plane easy axis. However, in the case of perpendicular anisotropy, even considering the higher-order spin-orbit torques, the velocity of domain wall cannot be efficiently enhanced by the current. Furthermore, the direction of wall motion is dependent on the configuration and chirality of domain wall with a current along the in-plane easy axis or transverse to the perpendicular one. Especially, the direction of motion can be controlled by the initial chirality of domain wall. So, if only involving the spin-orbit mechanism, it is preferable to adopt the scheme of a current along the in-plane easy axis for enhancing the velocity and controlling the direction of domain wall.

  16. The stability of steady motion of magnetic domain wall: Role of higher-order spin-orbit torques

    NASA Astrophysics Data System (ADS)

    He, Peng-Bin; Yan, Han; Cai, Meng-Qiu; Li, Zai-Dong

    2015-12-01

    The steady motion of magnetic domain wall driven by spin-orbit torques is investigated analytically in the heavy/ferromagnetic metal nanowires for three cases with a current transverse to the in-plane and perpendicular easy axis, and along the in-plane easy axis. By the stability analysis of Walker wall profile, we find that if including the higher-order spin-orbit torques, the Walker breakdown can be avoided in some parameter regions of spin-orbit torques with a current transverse to or along the in-plane easy axis. However, in the case of perpendicular anisotropy, even considering the higher-order spin-orbit torques, the velocity of domain wall cannot be efficiently enhanced by the current. Furthermore, the direction of wall motion is dependent on the configuration and chirality of domain wall with a current along the in-plane easy axis or transverse to the perpendicular one. Especially, the direction of motion can be controlled by the initial chirality of domain wall. So, if only involving the spin-orbit mechanism, it is preferable to adopt the scheme of a current along the in-plane easy axis for enhancing the velocity and controlling the direction of domain wall.

  17. Probabilistic elastic-plastic fracture analysis of cracked pipes with circumferential through-wall flaws

    SciTech Connect

    Rahman, S.; Brust, F.

    1995-11-01

    A probabilistic fracture model was developed to analyze circumferential through-walled-cracked pipes subjected to bending loads. It involved elastic-plastic finite element analysis for estimating energy releases rates, J-tearing theory for characterizing ductile fracture, and standard methods of structural reliability theory for conduction probabilistic analysis. The evaluation of J-integral was based on the deformation theory of plasticity and power-law idealizations of the stress-strain and fracture toughness curves. This allows J to be expressed in terms of non-dimensional influence functions (F- and h{sub 1}-functions) that depend on the crack size, pipe geometry, and material hardening constant. New equations were proposed to represent these functions and were applied to conduct stochastic pipe fracture evaluations. Both analytical and simulation methods were formulated to determine the probabilistic characteristics of J. The same methods were used later to predict the failure probability of pipes as a function of the applied load. Numerical examples are provided to illustrate the proposed methodology. The validity of J-integral based on the proposed equations for predicting crack driving force in a through-wall-cracked pipe was evaluated by comparing with available results in the current literature. Probability densities of J-integral were predicted as a function of applied loads. Failure probabilities corresponding to three different performance criteria were evaluated for a stainless steel nuclear piping in the Boiling Water Reactor plant. The results suggest that large differences may exist in the failure probability estimates produced by these performance criteria.

  18. Examination of Relationship Between Photonic Signatures and Fracture Strength of Fused Silica Used in Orbiter Windows

    NASA Technical Reports Server (NTRS)

    Yost, William T.; Cramer, K. Elliott; Estes, Linda R.; Salem, Jonathan A.; Lankford, James, Jr.; Lesniak, Jon

    2011-01-01

    A commercially available grey-field polariscope (GFP) instrument for photoelastic examination is used to assess impact damage inflicted upon the outermost pane of the orbiter windows. Four categories of damage: hyper-velocity impacts that occur during space-flight (HVI); hypervelocity impacts artificially made at the Hypervelocity Impact Technology Facility (HIT-F); impacts made by larger objects falling onto the pane surface to simulate dropped items on the window during service/storage of vehicle (Bruises); and light scratches from dull objects designed to mimic those that might occur by dragging a dull object across the glass surface (Chatter Checks) are examined. The damage sites are cored from fused silica window carcasses, examined with the GFP and other methodologies, and broken using the ASTM Standard C1499-09 to measure the fracture strength. A correlation is made between the fracture strength and damage-site measurements including geometrical measurements and GFP measurements of photoelastic retardation (stress patterns) surrounding the damage sites. An analytical damage model to predict fracture strength from photoelastic retardation measurements is presented and compared with experimental results.

  19. The Hydraulic Mechanism in the Orbital Blowout Fracture Because of a High-Pressure Air Gun Injury.

    PubMed

    Kang, Seok Joo; Chung, Eui Han

    2015-10-01

    There are 2 predominant mechanisms that are used to explain the pathogenesis of orbital blowout fracture; these include hydraulic and buckling mechanisms. Still, however, its pathophysiology remains uncertain. To date, studies in this series have been conducted using dry skulls, cadavers, or animals. But few clinical studies have been conducted to examine whether the hydraulic mechanism is involved in the occurrence of pure orbital blowout fracture. The authors experienced a case of a 52-year-old man who had a pure medial blowout fracture after sustaining an eye injury because of a high-pressure air gun. Our case suggests that surgeons should be aware of the possibility that the hydraulic mechanism might be involved in the blowout fracture in patients presenting with complications, such as limitation of eye movement, diplopia, and enophthalmos. PMID:26468824

  20. Infraorbital nerve transpositioning into orbital floor: a modified technique to minimize nerve injury following zygomaticomaxillary complex fractures

    PubMed Central

    Kotrashetti, Sharadindu Mahadevappa; Kale, Tejraj Pundalik; Bhandage, Supriya

    2015-01-01

    Objectives Transpositioning of the inferior alveolar nerve to prevent injury in lower jaw has been advocated for orthognathic, pre-prosthetic and for implant placement procedures. However, the concept of infra-orbital nerve repositioning in cases of mid-face fractures remains unexplored. The infraorbital nerve may be involved in trauma to the zygomatic complex which often results in sensory disturbance of the area innervated by it. Ten patients with infraorbital nerve entrapment were treated in similar way at our maxillofacial surgery centre. Materials and Methods In this article we are reporting three cases of zygomatico-maxillary complex fracture in which intra-operative repositioning of infra-orbital nerve into the orbital floor was done. This was done to release the nerve from fractured segments and to reduce the postoperative neural complications, to gain better access to fracture site and ease in plate fixation. This procedure also decompresses the nerve which releases it off the soft tissue entrapment caused due to trauma and the organized clot at the fractured site. Results There was no evidence of sensory disturbance during their three month follow-up in any of the patient. Conclusion Infraorbital nerve transposition is very effective in preventing paresthesia in patients which fracture line involving the infraorbital nerve. PMID:25922818

  1. Orbital Wall Reconstruction with Two-Piece Puzzle 3D Printed Implants: Technical Note.

    PubMed

    Mommaerts, Maurice Y; Büttner, Michael; Vercruysse, Herman; Wauters, Lauri; Beerens, Maikel

    2016-03-01

    The purpose of this article is to describe a technique for secondary reconstruction of traumatic orbital wall defects using titanium implants that act as three-dimensional (3D) puzzle pieces. We present three cases of large defect reconstruction using implants produced by Xilloc Medical B.V. (Maastricht, the Netherlands) with a 3D printer manufactured by LayerWise (3D Systems; Heverlee, Belgium), and designed using the biomedical engineering software programs ProPlan and 3-Matic (Materialise, Heverlee, Belgium). The smaller size of the implants allowed sequential implantation for the reconstruction of extensive two-wall defects via a limited transconjunctival incision. The precise fit of the implants with regard to the surrounding ledges and each other was confirmed by intraoperative 3D imaging (Mobile C-arm Systems B.V. Pulsera, Philips Medical Systems, Eindhoven, the Netherlands). The patients showed near-complete restoration of orbital volume and ocular motility. However, challenges remain, including traumatic fat atrophy and fibrosis. PMID:26889349

  2. Lateral view of facial fractures: new observations

    SciTech Connect

    Daffner, R.H.; Apple, J.S.; Gehweiler, J.A.

    1983-09-01

    Traditional plain film evaluation of facial fractures includes a lateral view of the face. This projection is often not exploited to its full potential because the many overlapping shadows are perceived to detract from its usefulness. To assess the value of this view, the authors reviewed the lateral facial films of 50 patients with a variety of fractures including 25 orbital blow-out fractures, 27 zygomaticomaxillary complex fractures, and 17 maxillary (including Le Fort) fractures. Three observations were encountered: orbital floor displacement in 60% of orbital fractures; malar strut displacement in 41% of zygomaticomaxillary complex fractures; and maxillary wall displacement in 76% of maxillary fractures. The presence of any of these structural displacements, either alone or in combination, provides further direct evidence of skeletal disruption and should serve to augment the findings observed on frontal views.

  3. Lower Eyelid Malposition Following Orbital Fracture Surgery: A Retrospective Analysis Based on 198 Surgeries.

    PubMed

    Kesselring, Alexandra G; Promes, Paul; Strabbing, Elske M; van der Wal, Karel G H; Koudstaal, Maarten J

    2016-06-01

    The aim of this study is to analyze the development of lower eyelid malposition following reconstruction of orbital fractures, in relation to the incisions used for access. A total of 198 surgical orbital floor reconstructions were performed in 175 patients between 2001 and 2011. Preoperative and postoperative presence of lower eyelid malposition of patients was reported. The types of incision used for access were as follows: approach via laceration (4.5%), via preexisting scar (16.2%), infraorbital (40.9%), subciliar (23.7%), transconjunctival (13.1%), and transconjunctival with lateral canthotomy (1.5%). The incidence of ectropion development following surgery was 3.0% and the incidence of entropion development following surgery was 1.0%. The highest rate of ectropion (11.1%) was seen using an approach via a laceration, followed by approach via a scar (6.3%). Our conclusion is that the transconjunctival incision without a lateral canthotomy has a low complication rate, provides adequate exposure, and leaves no visible scar. PMID:27162565

  4. Crystal orbital study on the double walls made of nanotubes encapsulated inside zigzag carbon nanotubes

    SciTech Connect

    Zhao, Xin; Qiao, Weiye; Li, Yuliang; Huang, Yuanhe

    2015-01-15

    The structure stabilities and electronic properties are investigated by using ab initio self-consistent-field crystal orbital method based on density functional theory for the one-dimensional (1D) double-wall nanotubes made of n-gon SiO{sub 2} nanotubes encapsulated inside zigzag carbon nanotubes. It is found that formation of the combined systems is energetically favorable when the distance between the two constituents is around the Van der Waals scope. The obtained band structures show that all the combined systems are semiconductors with nonzero energy gaps. The frontier energy bands (the highest occupied band and the lowest unoccupied band) of double-wall nanotubes are mainly derived from the corresponding carbon nanotubes. The mobilities of charge carriers are calculated to be within the range of 10{sup 2}–10{sup 4} cm{sup 2} V{sup −1} s{sup −1} for the hybrid double-wall nanotubes. Young’s moduli are also calculated for the combined systems. For the comparison, geometrical and electronic properties of n-gon SiO{sub 2} nanotubes are also calculated and discussed. - Graphical abstract: Structures and band structures of the optimum 1D Double walls nanotubes. The optimized structures are 3-gon SiO2@(15,0), 5-gon SiO2@(17,0), 6-gon SiO2@(18,0) and 7-gon SiO2@(19,0). - Highlights: • The structure and electronic properties of the 1D n-gon SiO{sub 2}@(m,0)s are studied using SCF-CO method. • The encapsulation of 1D n-gon SiO{sub 2} tubes inside zigzag carbon nanotubes can be energetically favorable. • The 1D n-gon SiO{sub 2}@(m,0)s are all semiconductors. • The mobility of charge carriers and Young’s moduli are calculated.

  5. Predictive value of visual evoked potentials, relative afferent pupillary defect, and orbital fractures in patients with traumatic optic neuropathy

    PubMed Central

    Tabatabaei, Seyed Ali; Soleimani, Mohammad; Alizadeh, Mahdi; Movasat, Morteza; Mansoori, Mohammad Reza; Alami, Zakieh; Foroutan, Alireza; Joshaghani, Mahmood; Safari, Saeid; Goldiz, Arzhang

    2011-01-01

    Background: The purpose of this study was to determine the predictive value of flash visual-evoked potentials (VEP), relative afferent pupillary defect, and presence of orbital fractures in patients with traumatic optic neuropathy. Methods: A prospective study was conducted in 15 patients with indirect traumatic optic neuropathy. All patients underwent a thorough ophthalmic examination. Initial visual acuity, final visual acuity, and relative afferent pupillary defect were determined, and visual acuity was converted into logMAR units. We performed flash VEP and an orbital computed tomography scan in all patients. Results: There was a good correlation between relative afferent pupillary defect and final visual acuity (r = −0.83), and better initial visual acuity could predict better final visual acuity (r = 0.92). According to findings from flash VEP parameters, there was a relationship between final visual acuity and amplitude ratio of the wave (r = 0.59) and latency ratio of the wave (r = −0.61). Neither primary visual acuity nor final visual acuity was related to the presence of orbital fractures in the orbital CT scan. Conclusion: Patients with traumatic optic neuropathy often present with severe vision loss. Flash VEP, poor initial visual acuity, and higher grade of relative afferent pupillary defect could predict final visual acuity in these patients. Presence of orbital fracture was not a predictive factor for primary visual acuity or final visual acuity. PMID:21845028

  6. Environmentally-controlled fracture of an overstrained A723 steel thick-walled cylinder

    NASA Astrophysics Data System (ADS)

    Underwood, J. H.; Olmstead, V. J.; Askew, J. C.; Kapusta, A. A.; Young, G. A.

    1992-08-01

    A through-wall, 1.7 m long crack grew suddenly from a notch in a 285 mm outer diameter (OD) of an A723 steel overstrained tube that was undergoing plating operations with no externally applied loads. The fracture mechanics tests and analyses and the fractography performed to characterize the cracking are described. The tube had a yield strength of 1200 MPa, fracture toughness of 150 MPavm, and a tensile residual stress at the OD of about 600 MPa. The composition was typical of an air-melt A723 steel, and the electropolishing bath, consisting of sulfuric and phosphoric acids, was held at 54 C. The bolt-loaded test for the threshold stress intensity factor for environmentally controlled cracking described by Wei and Novak was used here with two significant modifications. Some tests included only a notch with the radius matching that of the tube, and a new expression for K in terms of crack-mouth displacement was developed and used. Scanning electron microscope fractography and energy dispersive x ray spectra were used to identify crack mechanisms. Results of the study include: (1) a measured threshold of hydrogen stress cracking for the material/environment below 20 MPavm; (2) da/dt versus K behavior typical of classic environmental control; and (3) an improved K/v expression for the bolt-loaded specimen and associated criteria for determining plane-strain test conditions in relation to the Irwin plastic zone.

  7. Results after En Bloc Lateral Wall Decompression Surgery with Orbital Fat Resection in 111 Patients with Graves' Orbitopathy

    PubMed Central

    Fichter, Nicole; Guthoff, Rudolf F.

    2015-01-01

    Purpose. To evaluate the effect of en bloc lateral wall decompression with additional orbital fat resection in terms of exophthalmos reduction and complications. Methods. A retrospective, noncomparative case series study from 1999 to 2011 (chart review) in Graves' orbitopathy (GO) patients. The standardized surgical technique involved removal of the lateral orbital wall including the orbital rim via a lid crease approach combined with additional orbital fat resection. Exophthalmos, diplopia, retrobulbar pressure sensation, and complications were analyzed pre- and postoperatively. Results. A total of 111 patients (164 orbits) with follow-up >3 months were analysed. Mean exophthalmos reduction was 3.05mm and preoperative orbital pressure sensation resolved or improved in all patients. Visual acuity improved significantly in patients undergoing surgery for rehabilitative or vision threatening purposes. Preoperative diplopia improved in 10 patients (9.0%) but worsened in 5 patients (4.5%), necessitating surgical correction in 3 patients. There were no significant complications; however, one patient had slight hollowing of the temporalis muscle around the scar that did not necessitate revision, and another patient with a circumscribed retraction of the scar itself underwent surgical correction. Conclusions. The study confirms the efficiency of en bloc lateral wall decompression in GO in a large series of patients, highlighting the low risk of disturbance of binocular functions and of cosmetic blemish in the temporal midface region. PMID:26221142

  8. Numerical Investigation of the Effect of the Location of Critical Rock Block Fracture on Crack Evolution in a Gob-side Filling Wall

    NASA Astrophysics Data System (ADS)

    Li, Xuehua; Ju, Minghe; Yao, Qiangling; Zhou, Jian; Chong, Zhaohui

    2016-03-01

    Generation, propagation, and coalescence of the shear and tensile cracks in the gob-side filling wall are significantly affected by the location of the fracture of the critical rock block. The Universal Discrete Element Code software was used to investigate crack evolution characteristics in a gob-side filling wall and the parameter calibration process for various strata and the filling wall was clearly illustrated. The cracks in both the filling wall and the coal wall propagate inward in a V-shape pattern with dominant shear cracks generated initially. As the distance between the fracture and the filling wall decreases, the number of cracks in the filling wall decreases, and the stability of the filling wall gradually improves; thus, by splitting the roof rock at the optimal location, the filling wall can be maintained in a stable state. Additionally, we conducted a sensitivity analysis that demonstrated that the higher the coal seam strength, the fewer cracks occur in both the filling wall and the coal wall, and the less failure they experience. With the main roof fracturing into a cantilever structure, the higher the immediate roof strength, the fewer cracks are in the filling wall. With the critical rock block fracturing above the roadway, an optimal strength of the immediate roof can be found that will stabilize the filling wall. This study presents a theoretical investigation into stabilization of the filling wall, demonstrating the significance of pre-splitting the roof rock at a desirable location.

  9. Survey of Common Practices among Oculofacial Surgeons in the Asia-Pacific Region: Management of Orbital Floor Blowout Fractures

    PubMed Central

    Koh, Victor; Chiam, Nathalie; Sundar, Gangadhara

    2014-01-01

    A web-based anonymous survey was performed to assess common practices of oculofacial surgeons in the management of traumatic orbital floor blowout fractures. A questionnaire which contained questions on several controversial topics in the management of orbital floor fractures was sent out via e-mail to 131 oculofacial surgeons in 14 countries in the Asia-Pacific region. A total response rate of 58.3% was achieved from May to December 2012. The preferred time for surgical intervention was within 2 weeks for adult patients, porous polyethylene implant was the most popular choice, and most surgeons preferred the transconjunctival approach. Postoperatively, diplopia was the most commonly encountered complication and most oculofacial surgeons reviewed their patients regularly for up to 12 months. We report the results of the first survey of oculofacial surgeons within the Asia-Pacific region on the management of orbital floor blowout fractures. Compared with previous surveys (from year 2000 to 2004), the duration to surgical intervention was comparable but there was a contrasting change in preferred surgical approach and choice of orbital implant. PMID:25136408

  10. Retroseptal Transconjunctival Approach for Blowout Fracture of the Orbital Floor: An Ideal Choice in East-Asian Patients

    PubMed Central

    Chuman, Takahiro; Fujii, Tatsuya; Morikawa, Aya; Kikuchi, Mamoru; Watanabe, Hidetaka

    2016-01-01

    Objective: To ask experts in the field to evaluate a surgeon’s experience with a retroseptal transconjunctival approach for the repair of the orbital floor damaged by blowout fracture that the surgeon encountered in 12 East-Asian patients. Methods: Patients were identified from a database, and a retrospective case note review was conducted. A total of 12 conjunctival procedures were conducted for the repair of blowout fracture with no other complicating fractures. All operative procedures were done by transconjunctival approach alone without lateral canthotomy or any other additional approach. Results: The repair of the orbital floor was successful in all the cases. Three patients had bone grafting to the orbital floor after reduction. The mean of overall surgical time was 48.8 minutes (range, 22–85 minutes) for orbit exposure by transconjunctival approach plus reduction and bone grafting when applicable. There were 6 urgent surgeries associated with missing or entrapment of the inferior rectus muscle, and its repair took an average of 32.0 minutes (range, 22–41 minutes). Postoperative diplopia recovered at an average of 12.4 weeks (range, 0–60 weeks); in urgent cases, it took an average of 5.3 weeks (range, 0–14 weeks) before recovery. Conclusions: A retroseptal transconjunctival approach in repairing the orbital floor is a simple, easily manageable, and effective procedure, leaving no conspicuous facial scars. It has proved to be an optimal choice in blowout fracture cases, especially when there was urgency to decompress the ischemic inferior rectus muscle in as short a surgery time as possible. PMID:27579249

  11. Blow-in fracture of the orbital roof presenting as a case of non-resolving choroidal effusion.

    PubMed

    Mukherjee, Bipasha; Bhende, Muna

    2010-01-01

    A 34-year-old male patient was referred to us as a case of non-resolving suprachoroidal hemorrhage. History revealed decrease in right eye vision following trauma to forehead. B scan ultrasonography (USG) of the right eye showed a high-reflective structure indenting the globe. It turned out to be an inferiorly displaced fracture fragment from the orbital roof on computerized tomography (CT) scan. The choroidal elevation disappeared after open reduction of the fracture fragment and patient had good recovery of vision. USG and CT scan were helpful in the diagnosis and management of this case. PMID:20534928

  12. The application and progress of high-density porous polyethylene in the repair of orbital wall defect.

    PubMed

    Qian, Zhuyun; Fan, Xianqun

    2014-07-01

    High-density porous polyethylene is a type of polymeric biomaterial. When used to efficiently fill the extensive orbital volume and correct enophthalmos caused by orbital wall defect, it has a significant advantage of biocompatibility, which results in a low rate of postoperative exposure and infection. The major disadvantage of this material is its radiolucency. However, with the development of imaging techniques, it is now possible to use multidetector computed tomography to directly contour the implant and describe its position. The use of tissue engineering involving high-density porous polyethylene will further improve its biocompatibility. At the same time, composite materials will play an important role in the repair of orbital wall defect. PMID:24911609

  13. Posttraumatic Orbital Emphysema: A Numerical Model

    PubMed Central

    Skorek, Andrzej; Kłosowski, Paweł; Plichta, Łukasz; Zmuda Trzebiatowski, Marcin; Lemski, Paweł

    2014-01-01

    Orbital emphysema is a common symptom accompanying orbital fracture. The pathomechanism is still not recognized and the usually assumed cause, elevated pressure in the upper airways connected with sneezing or coughing, does not always contribute to the occurrence of this type of fracture. Observations based on the finite model (simulating blowout type fracture) of the deformations of the inferior orbital wall after a strike in its lower rim. Authors created a computer numeric model of the orbit with specified features—thickness and resilience modulus. During simulation an evenly spread 14400 N force was applied to the nodular points in the inferior rim (the maximal value not causing cracking of the outer rim, but only ruptures in the inferior wall). The observation was made from 1 · 10−3 to 1 · 10−2 second after a strike. Right after a strike dislocations of the inferior orbital wall toward the maxillary sinus were observed. Afterwards a retrograde wave of the dislocation of the inferior wall toward the orbit was noticed. Overall dislocation amplitude reached about 6 mm. Based on a numeric model of the orbit submitted to a strike in the inferior wall an existence of a retrograde shock wave causing orbital emphysema has been found. PMID:25309749

  14. Posttraumatic orbital emphysema: a numerical model.

    PubMed

    Skorek, Andrzej; Kłosowski, Paweł; Plichta, Lukasz; Raczyńska, Dorota; Zmuda Trzebiatowski, Marcin; Lemski, Paweł

    2014-01-01

    Orbital emphysema is a common symptom accompanying orbital fracture. The pathomechanism is still not recognized and the usually assumed cause, elevated pressure in the upper airways connected with sneezing or coughing, does not always contribute to the occurrence of this type of fracture. Observations based on the finite model (simulating blowout type fracture) of the deformations of the inferior orbital wall after a strike in its lower rim. Authors created a computer numeric model of the orbit with specified features-thickness and resilience modulus. During simulation an evenly spread 14400 N force was applied to the nodular points in the inferior rim (the maximal value not causing cracking of the outer rim, but only ruptures in the inferior wall). The observation was made from 1 · 10(-3) to 1 · 10(-2) second after a strike. Right after a strike dislocations of the inferior orbital wall toward the maxillary sinus were observed. Afterwards a retrograde wave of the dislocation of the inferior wall toward the orbit was noticed. Overall dislocation amplitude reached about 6 mm. Based on a numeric model of the orbit submitted to a strike in the inferior wall an existence of a retrograde shock wave causing orbital emphysema has been found. PMID:25309749

  15. Spin-orbit torques for current parallel and perpendicular to a domain wall

    SciTech Connect

    Schulz, Tomek; Lee, Kyujoon; Karnad, Gurucharan V.; Alejos, Oscar; Martinez, Eduardo; Moretti, Simone; Garcia, Karin; Ravelosona, Dafiné; Vila, Laurent; Lo Conte, Roberto; Kläui, Mathias; Ocker, Berthold; Brataas, Arne

    2015-09-21

    We report field- and current-induced domain wall (DW) depinning experiments in Ta\\Co{sub 20}Fe{sub 60}B{sub 20}\\MgO nanowires through a Hall cross geometry. While purely field-induced depinning shows no angular dependence on in-plane fields, the effect of the current depends crucially on the internal DW structure, which we manipulate by an external magnetic in-plane field. We show depinning measurements for a current sent parallel to the DW and compare its depinning efficiency with the conventional case of current flowing perpendicularly to the DW. We find that the maximum efficiency is similar for both current directions within the error bars, which is in line with a dominating damping-like spin-orbit torque (SOT) and indicates that no large additional torques arise for currents perpendicular to the DW. Finally, we find a varying dependence of the maximum depinning efficiency angle for different DWs and pinning levels. This emphasizes the importance of our full angular scans compared with previously used measurements for just two field directions (parallel and perpendicular to the DW) to determine the real torque strength and shows the sensitivity of the SOT to the precise DW structure and pinning sites.

  16. Spin-orbit torques for current parallel and perpendicular to a domain wall

    NASA Astrophysics Data System (ADS)

    Schulz, Tomek; Alejos, Oscar; Martinez, Eduardo; Hals, Kjetil M. D.; Garcia, Karin; Vila, Laurent; Lee, Kyujoon; Lo Conte, Roberto; Karnad, Gurucharan V.; Moretti, Simone; Ocker, Berthold; Ravelosona, Dafiné; Brataas, Arne; Kläui, Mathias

    2015-09-01

    We report field- and current-induced domain wall (DW) depinning experiments in TaCo20Fe60B20MgO nanowires through a Hall cross geometry. While purely field-induced depinning shows no angular dependence on in-plane fields, the effect of the current depends crucially on the internal DW structure, which we manipulate by an external magnetic in-plane field. We show depinning measurements for a current sent parallel to the DW and compare its depinning efficiency with the conventional case of current flowing perpendicularly to the DW. We find that the maximum efficiency is similar for both current directions within the error bars, which is in line with a dominating damping-like spin-orbit torque (SOT) and indicates that no large additional torques arise for currents perpendicular to the DW. Finally, we find a varying dependence of the maximum depinning efficiency angle for different DWs and pinning levels. This emphasizes the importance of our full angular scans compared with previously used measurements for just two field directions (parallel and perpendicular to the DW) to determine the real torque strength and shows the sensitivity of the SOT to the precise DW structure and pinning sites.

  17. Clinical effect of a mixed solution of sodium hyaluronate and sodium carboxymethylcellulose during the transconjunctival approach for orbital wall reconstruction.

    PubMed

    Kang, Byung Wan; Lee, Hyo Seok; Oh, Han Jin; Yoon, Kyung Chul

    2012-08-01

    This study aimed to evaluate the anti-adhesive effect of a mixed solution of sodium hyaluronate and sodium carboxymethylcellulose (HACMC, Guardix-sol®) during the transconjunctival approach to orbital wall reconstruction. Eighty-seven patients who underwent orbital wall reconstruction by the transconjunctival approach were enrolled in this prospective study. We applied HACMC between the orbicularis oculi muscle and the orbital septum after surgery in 47 patients and did not use it in 40 patients. Lower lid retraction and marginal reflex distance 2 (MRD(2)) were measured to analyze the degree of postoperative adhesion at 1 week and 1, 3, and 6 months. The degree of MRD(2) showed clinically significant differences at postoperative 1 week and 1 month between the HACMC and control groups (p<0.05). Lower lid ectropion developed in two patients (5.0%) in the control group but did not occur in the HACMC group. In orbital wall reconstruction by the transconjunctival approach, the HACMC mixture solution is effective for preventing adhesion and lower lid ectropion during the early postoperative period. PMID:22977754

  18. Clinical Effect of a Mixed Solution of Sodium Hyaluronate and Sodium Carboxymethylcellulose During the Transconjunctival Approach for Orbital Wall Reconstruction

    PubMed Central

    Kang, Byung Wan; Lee, Hyo Seok; Oh, Han Jin

    2012-01-01

    This study aimed to evaluate the anti-adhesive effect of a mixed solution of sodium hyaluronate and sodium carboxymethylcellulose (HACMC, Guardix-sol®) during the transconjunctival approach to orbital wall reconstruction. Eighty-seven patients who underwent orbital wall reconstruction by the transconjunctival approach were enrolled in this prospective study. We applied HACMC between the orbicularis oculi muscle and the orbital septum after surgery in 47 patients and did not use it in 40 patients. Lower lid retraction and marginal reflex distance 2 (MRD2) were measured to analyze the degree of postoperative adhesion at 1 week and 1, 3, and 6 months. The degree of MRD2 showed clinically significant differences at postoperative 1 week and 1 month between the HACMC and control groups (p<0.05). Lower lid ectropion developed in two patients (5.0%) in the control group but did not occur in the HACMC group. In orbital wall reconstruction by the transconjunctival approach, the HACMC mixture solution is effective for preventing adhesion and lower lid ectropion during the early postoperative period. PMID:22977754

  19. Epithelial cysts associated with alloplastic implants after repair of orbital fractures: a systematic review and four new cases.

    PubMed

    Su, Yun; Sun, Jing; Fan, Xianqun

    2016-07-01

    An epithelial cyst is a rare and often late complication of long-term alloplastic implants, which has the potential to lead to further complications and harm to patients. We made a systematic review of papers published during the past 30 years about the mechanisms and clinical characteristics formation of epithelial cysts after repair of an orbital fracture by searching PubMed, Medline, and Web of Science to collect all related case reports and series published in the English language. We also made a retrospective review of casenotes of all patients diagnosed with orbital epithelial cysts in our department. We found 19 cases of epithelial cysts, including the four cases of our own, associated with alloplastic material, 12 of which were associated with silicone. There were 12 men and seven women aged from 26-71 years old. Orbital cysts developed 15 months-31 (median 8) years after implantation. Histological analysis confirmed that the cysts were all epithelial cysts lined with squamous or respiratory (or both) cells, and differing degrees of chronic inflammation. Epithelial cysts after implantation of alloplastic material may present with various symptoms several years after repair of orbital fractures, and their formation probably results from the synergistic effects of both ectopic cells and chronic inflammation. The implant itself may be a trigger, and the cysts did not seem to be limited to one specific type of implant. PMID:27094498

  20. The history of the walls of the Acropolis of Athens and the natural history of secondary fracture healing process.

    PubMed

    Lyritis, G P

    2000-09-01

    During its long and adventurous history, the Acropolis of Athens has been a site of many dramatic events. It suffered its most disastrous destruction during the Persian wars. Under the command of King Xerxes, the Persians invaded Athens and ruined the Temple of the Parthenon and the walls of the Acropolis. After their victorious sea battle at Salamis, the Athenians, led by Themistocles, returned home and tried to repair the damage. Their priority still was to defend their city by restoring the walls of the Acropolis. Materials of all kinds were salvaged from the ruins of the Acropolis and used for an immediate reconstruction of the walls. Later, when the Athenians became the leaders of the Greek world, it was decided that the walls should be rebuilt in a proper artistic way. Themistocles suggested that a small section of the walls, which had formerly been a part of the urgent restoration, should remain in place so as to remind the citizens of this historical event. This is a characteristic example of the biological and mechanical adaptation of fracture callus to musculoskeletal function. After a period of urgency with the fixation of a fracture by means of a primitive secondary callus formation, the broken limb gradually returns to its usual function. Increased mechanical loading enhances the remodelling of the callus and the replacement of woven bone with lamellar bone. PMID:15758516

  1. Isolated trapdoor-type medial blowout fracture in an adult presenting horizontal diplopia treated by endoscopic endonasal approach.

    PubMed

    Noh, Woong Jae; Park, Tae Jung; Kim, Joo Yeon; Kwon, Jae Hwan

    2013-01-01

    Orbital blowout fracture frequently occurs along the floor or medial aspect of the orbital wall, which are the two thinnest areas of the bony orbit. True trapdoor injury of the orbit is less common and is rare as an isolated medial wall injury, because the medial orbital wall has several bony septa within the ethmoid sinus that provide support and decrease the risk of a trapdoor fracture. Additionally, the incidence of trapdoor-type blowout fracture in adults is lower than in children. In a trapdoor-type blowout fracture with restricted ocular movement, prompt diagnosis and early intervention are associated with better clinical outcomes. We encountered a case of trap door-type medial blowout fracture with horizontal eye ball movement limitation in an adult. She underwent endonasal endoscopic reduction surgery for the medial blowout fractures. Here we report this case, and suggest early diagnosis and prompt surgical exploration. PMID:24964421

  2. Clinical and Radiologic Characteristics of Inferior Rectus Muscle Sheath Entrapment in Orbital Blowout Fracture.

    PubMed

    Bagheri, Abbas; Tavakoli, Mehdi; Khosravifard, Keivan; Yazdani, Shahin

    2015-10-01

    Blowout fracture is a common condition in the oculoplastics clinic. One of the indications for its repair is entrapment of the inferior rectus muscle within the fracture site. Herein, the authors present 3 patients of inferior rectus muscle sheath entrapment without entrapment of the muscle itself. The outcome of treatment was excellent in all patients. The aim of this report is to present the special clinical and radiologic findings in such patients. PMID:26413961

  3. Fractures

    PubMed Central

    Hall, Michael C.

    1963-01-01

    Recent studies on the epidemiology and repair of fractures are reviewed. The type and severity of the fracture bears a relation to the age, sex and occupation of the patient. Bone tissue after fracture shows a process of inflammation and repair common to all members of the connective tissue family, but it repairs with specific tissue. Cartilage forms when the oxygen supply is outgrown. After a fracture, the vascular bed enlarges. The major blood supply to healing tissue is from medullary vessels and destruction of them will cause necrosis of the inner two-thirds of the cortex. Callus rapidly mineralizes, but full mineralization is achieved slowly; increased mineral metabolism lasts several years after fracture. PMID:13952119

  4. Orbital Fracture Leading to Severe Multifascial Space Infection Including the Parapharyngeal Space: A Report of a Case and Review of the Literature

    PubMed Central

    Park, Chan; Marchiori, Erica; Barber, Jacob; Cardon, Curtis

    2014-01-01

    Orbital trauma can result in periorbital and orbital infections. Orbital infections have been classified by Chandler et al in 1970 to their anatomic location and boundaries. This case report describes a patient who developed a severe orbital infection following orbital fractures. The infection progressed to the parapharyngeal space. The patient required multiple incision and drainage surgeries and tissue debridements to have clinical resolution. To our knowledge, there has not been a case described in the literature of an orbital infection progressing to the parapharyngeal space. A literature review of orbital trauma leading to infection discusses the pathogenesis of the infections. This case demonstrates that close clinical follow-up and appropriate medical management of comorbidities that put a patient at higher risk of developing an infection is of the utmost importance in the treatment of maxillofacial trauma patients. PMID:25136414

  5. Fractures

    MedlinePlus

    ... commonly happen because of car accidents, falls, or sports injuries. Other causes are low bone density and osteoporosis, which cause weakening of the bones. Overuse can cause stress fractures, which are very small cracks in the ...

  6. Fractures

    MedlinePlus

    A fracture is a break, usually in a bone. If the broken bone punctures the skin, it is called an open ... falls, or sports injuries. Other causes are low bone density and osteoporosis, which cause weakening of the ...

  7. Lubrication theory analysis of the permeability of rough-walled fractures

    SciTech Connect

    Zimmerman, R.W.; Kumar, S.; Bodvarsson, G.S.

    1991-01-01

    The flow of a fluid between the rough surfaces of a rock fracture is very complex, due to the tortuous paths followed by the fluid particles. Exact analytical modeling of these flows is made difficult by the irregular geometry of rock fracture surfaces, while full three-dimensional numerical simulations of these flows are as yet still impractical. To overcome the difficulties of working with the three-dimensional Navier-Stokes equations, the simpler Reynolds lubrication equation has sometimes been used to model flow in fractures. This paper focuses on two aspects of lubrication theory. First, lubrication theory is applied to two simplified aperture profiles, sinusoidal and sawtooth, and analytical expressions are found for the permeabilities. These results are then compared with numerical results obtained by solving the lubrication equation for fractures with random surfaces. Secondly, the validity of the lubrication equations for modeling flow in rough fractures is studied by examining higher-order perturbation solutions, as well as numerical solutions, to the Navier-Stokes equations for flow in fractures with sinusoidally-varying apertures. 22 refs., 6 figs.

  8. Determination of effective field induced by spin-orbit torque using magnetic domain wall creep in Pt/Co structure

    NASA Astrophysics Data System (ADS)

    Koyama, T.; Chiba, D.

    2015-12-01

    We investigated the effect of electric current on the magnetic-field-driven magnetic domain wall (DW) creep velocity in ultrathin Co with perpendicular magnetic anisotropy deposited on a Pt underlayer. The DW velocity was considerably modulated by the current, and its field dependence deviated from the scaling law with the critical exponent of 1/4, which is generally valid in ferromagnetic metals. This characteristic feature of the DW motion can be explained by considering the perpendicular effective field generated by spin-orbit torque at the Pt/Co interface. From the relation between the injected current and the modified creep velocity, the determination of the effective field was demonstrated.

  9. Numerical Simulation of Impact Damage Induced by Orbital Debris on Shielded Wall of Composite Overwrapped Pressure Vessel

    NASA Astrophysics Data System (ADS)

    Cherniaev, Aleksandr; Telichev, Igor

    2014-12-01

    This paper presents a methodology for numerical simulation of the formation of the front wall damage in composite overwrapped pressure vessels under hypervelocity impact. Both SPH particles and Lagrangian finite elements were employed in combination for numerical simulations. Detailed numerical models implementing two filament winding patterns with different degree of interweaving were developed and used to simulate 2.5 km/s and 5.0 km/s impacts of 5 mm-diameter spherical aluminum-alloy projectile. Obtained results indicate that winding pattern may have a pronounced effect on vessel damage in case of orbital debris impact, influencing propagation of the stress waves in composite material.

  10. Fracture behavior of shallow cracks in full-thickness clad beams from an RPV wall section

    SciTech Connect

    Keeney, J.A.; Bass, B.R.; McAfee, W.J.

    1995-04-01

    A testing program is described that utilizes full-thickness clad beam specimens to quantify fracture toughness for shallow cracks in weld material for which metallurgical conditions are prototypic of those found in reactor pressure vessels (RPVs). The beam specimens are fabricated from an RPV shell segment that includes weld, plate and clad material. Metallurgical factors potentially influencing fracture toughness for shallow cracks in the beam specimens include material gradients and material inhomogeneities in welded regions. The shallow-crack clad beam specimens showed a significant loss of constraint similar to that of other shallow-crack single-edge notch bend (SENB) specimens. The stress-based Dodds-Anderson scaling model appears to be effective in adjusting the test data to account for in-plane loss of constraint for uniaxially tested beams, but cannot predict the observed effects of out-of-plane biaxial loading on shallow-crack fracture toughness. A strain-based dual-parameter fracture toughness correlation (based on plastic zone width) performed acceptably when applied to the uniaxial and biaxial shallow-crack fracture toughness data.

  11. Flow visualization and relative permeability measurements in rough-walled fractures

    SciTech Connect

    Persoff, P.; Pruess, K.

    1993-01-01

    Two-phase (gas-liquid) flow experiments were done in a natural rock fracture and transparent replicas of natural fractures. Liquid was injected at constant volume flow rate, and gas was injected at either constant mass flow rate or constant pressure. When gas was injected at constant mass flow rate, the gas inlet pressure, and inlet and outlet capillary pressures, generally did not reach steady state but cycled irregularly. Flow visualization showed that this cycling was due to repeated blocking and unblocking of gas flow paths by liquid. Relative permeabilities calculated from flow rate and pressure data show that the sum of the relative permeabilities of the two phases is much less than 1, indicating that each phase interferes strongly with the flow of the other. Comparison of the relative permeability curves with typical curves for porous media (Corey curves) show that the phase interference is stronger in fractures than in typical porous media.

  12. Modified solution for finding the optimal angle of spacecraft walls under orbital debris impacts

    NASA Astrophysics Data System (ADS)

    Pantelides, Chris P.; Tzan, Shyh-Rong

    1993-06-01

    A modification to the procedure developed by Schonberg and Tullos (1991) to find the configuration and the parameters of a corrugated bumper that can reduce the potential for creation of ricochet debris, in the event of an on-orbit impact, is presented. It is shown that the optimal bumper rise angle depends on the ratio of ricochet debris velocity to spacecraft velocity, has an asymptotic value of 45 deg, and is independent of the spacecraft orientaion.

  13. Effects of capillary pressure and use of polymer solutions on dense, non-aqueous-phase liquid retention and mobilization in a rough-walled fracture

    SciTech Connect

    Longino, B.L.; Kueper, B.H. . Dept. of Civil Engineering)

    1999-07-15

    In this laboratory study, perchloroethylene (PCE) was permitted to migrate through a horizontal rough-walled limestone fracture under controlled conditions to assess fracture retention capacity. Retention of immiscible-phase PCE in the absence of an applied wetting-phase hydraulic gradient varied between 11% and 26% of the fracture volume. A portion of this residual could be removed through water flooding; however, even at the maximum applied hydraulic gradient of 1.0, residual PCE remained in the fracture. The observed correlation of reduced residual saturation with capillary number (N[sub c]) demonstrated that this rough-walled fracture exhibited behavior similar to that of a porous medium under water-flooding conditions. For a given hydraulic gradient, polymer-enhanced floods (using xanthan gum) were not as successful as conventional water flooding at removing residual from the fracture. The traditional form of the capillary number became an increasingly poor predictor of mobilization behavior as the viscosity of the displacing phase was increased. Incorporation of ([mu][sub w]/[mu][sub nw])[sup [minus]0.5] into the traditional capillary number provided a more appropriate dimensionless group with which to correlate residual PCE saturation in the fracture as [mu][sub w] increased.

  14. Fracture strengths of HIPed DS-Cu/SS joints for ITER shielding blanket/first wall

    NASA Astrophysics Data System (ADS)

    Hatano, T.; Kanari, M.; Sato, S.; Gotoh, M.; Furuya, K.; Kuroda, T.; Saito, M.; Enoeda, M.; Takatsu, H.

    1998-10-01

    Fracture toughness and crack propagation tests were performed to investigate the effect of HIP temperature and fracture behavior of HIPed DS-Cu/SS joints. Test specimens of DS-Cu/SS HIPed joints were manufactured by bonding flat plates of DS-Cu and SS under HIP temperatures of 980°C, 1030°C and 1050°C. JQ of the joint at HIP temperature of 1050°C was larger than the other two joints. For the crack propagation test, two types of test specimens were prepared. One had a notch along the HIPed interface and the other in DS-Cu and normal to the interface. The crack in the former specimen propagated along the interface. On the other hand, the crack in the latter specimen propagated in the DS-Cu perpendicular to the loading direction, stopped at the interface, and then exfoliated along the HIPed interface. In the fracture tests, the crack was observed propagating in DS-Cu side at approximately 5-10 μm away from the interface.

  15. Failure Analysis of Fractured Poppet from Space Shuttle Orbiter Flow Control Valve

    NASA Technical Reports Server (NTRS)

    Russell, Richard

    2010-01-01

    This slide presentation reviews the failure analysis of a fractured poppet from a flow control valve (FCV) used on the space shuttle. This presentation has focused on the laboratory analysis of the failed hardware. The use of Scanning electron fractography during the investigation led to the conclusion that the poppet failed due to fatigue cracking that, most likely, occurred under changing loading conditions. The initial investigation led to a more thorough test of poppets that had been retired, this testing led to the conclusion that the thumbnail cracks in the flight hardware had existed for the life of the shuttle program. This led to a program to develop an eddy current technique that was capable of detecting small very tight cracks.

  16. Recommendations for protecting against failure by brittle fracture: Category II and III ferritic steel shipping containers with wall thickness greater than four inches

    SciTech Connect

    Schwartz, M.W.; Fischer, L.E.

    1996-08-01

    This report provides criteria for selecting ferritic steels that would prevent brittle fracture in Category II and III shipping containers with wall thickness greater than 4 inches. These methods are extensions of those previously used for Category II and III containers less than 4 inches thick and Category I containers more than 4 inches thick.

  17. Ethmoid Osteoma as a Culprit of Orbital Emphysema

    PubMed Central

    Zhuang, Ai; Li, Yinwei; Lin, Ming; Shi, Wodong; Fan, Xianqun

    2015-01-01

    Abstract Orbital emphysema is generally recognized as a complication of orbital fractures involving any paranasal sinuses. The recognition about its etiology has extended beyond sole trauma, but few articles mentioned tumors to be a possible cause. In this case report, we present a patient with orbital emphysema associated with ethmoid osteoma without orbital cellulitis or trauma history. The patient developed sudden proptosis, eyelid swelling, and movement limitation of the left eye, peripheral diplopia, and left periorbital crepitus after a vigorous nose blowing. Complete surgical resection of ethmoid osteoma followed by repair of the orbital medial wall was performed with assistance of combined endoscopy and navigational techniques. Twelve-month follow-up showed no residual lesion or recurrence; the orbital medial wall was accurately repaired with good visual function and facial symmetry. Tumors should be considered for differential diagnosis of orbital emphysema, and combined endoscopy and navigational techniques may improve safety, accuracy, and effectiveness of orbital surgeries. PMID:25950683

  18. Nanoscale transport in single-walled carbon nanotubes with doubly degenerate orbitals

    NASA Astrophysics Data System (ADS)

    Makarovski, Alexander

    The unique properties of carbon nanotubes (CNT) have made these structures a popular subject of scientific research. One of the experimental techniques used to study the electronic band structure of nanotubes is low-temperature magneto-transport measurements. In this thesis, we report the results of employing this technique to study: (1) double orbital degeneracy of the quantum-mechanical energy levels in closed CNT Quantum Dots, (2) the Kondo effect at high contact transparency in the presence of level degeneracy, and (3) the influence of the superconductivity on electron transport in nanotubes. In the Coulomb blockade regime in CNT Quantum Dots, the alignment of the energy levels belonging to different orbitals is analyzed from the measured spacings between the conductance peaks. It is found that in properly fabricated individual nanotube samples a large percentage of the orbitals are doubly degenerate. The degree of the residual energy level misalignment is lower than in any of the previously published observations. We provide an explanation of how the degeneracy can be sustained in real nanotube samples. Additionally, observations of unexpected low-energy excitations at complete filling of four-electron shells are reported. In samples with relatively high tunneling barrier transparency, Kondo processes contribute to the enhancement of zero-bias conductance inside the Coulomb blockade valleys. At sufficiently low temperatures, individual single-electron conductance peaks within each four-electron shell completely merge. A new transport regime, where the different charge states are hybridized by the Kondo processes is reported. It is also found that the Kondo features at one-electron and three-electron shell occupancies behave noticeably different in a magnetic field, in violation of the electron-hole symmetry. The superconducting transition in the contacts significantly alters the properties of the nanotube; this is due to the superconducting proximity effect

  19. Improvement of the fracture toughness of hydroxyapatite (HAp) by incorporation of carboxyl functionalized single walled carbon nanotubes (CfSWCNTs) and nylon.

    PubMed

    Khanal, S P; Mahfuz, H; Rondinone, A J; Leventouri, Th

    2016-03-01

    The potential of improving the fracture toughness of synthetic hydroxyapatite (HAp) by incorporating carboxyl functionalized single walled carbon nanotubes (CfSWCNTs) and polymerized ε-caprolactam (nylon) was studied. A series of HAp samples with CfSWCNTs concentrations varying from 0 to 1.5 wt.%, without, and with nylon addition was prepared. X-ray diffraction (XRD), Scanning Electron Microscopy (SEM), and Transmission Electron Microscopy (TEM) were used to characterize the samples. The three point bending test was applied to measure the fracture toughness of the composites. A reproducible value of 3.6±0.3 MPa.√m was found for samples containing 1 wt.% CfSWCNTs and nylon. This value is in the range of the cortical bone fracture toughness. Increase of the CfSWCNTs content results to decrease of the fracture toughness, and formation of secondary phases. PMID:26706523

  20. Improvement of the fracture toughness of hydroxyapatite (HAp) by incorporation of carboxyl functionalized single walled carbon nanotubes (CfSWCNTs) and nylon

    SciTech Connect

    Khanal, Suraj P.; Mahfuz, Hassan; Rondinone, Adam Justin; Leventouri, Th.

    2015-11-12

    The potential of improving the fracture toughness of synthetic hydroxyapatite (HAp) by incorporating carboxyl functionalized single walled carbon nanotubes (CfSWCNTs) and polymerized ε-caprolactam (nylon) was researched. A series of HAp samples with CfSWCNTs concentrations varying from 0 to 1.5 wt.%, without, and with nylon addition was prepared. X-ray diffraction (XRD), Scanning Electron Microscopy (SEM), and Transmission Electron Microscopy (TEM) were used to characterize the samples. The three point bending test was applied to measure the fracture toughness of the composites. A reproducible value of 3.6 ± 0.3 MPa.√m was found for samples containing 1 wt.% CfSWCNTs and nylon. This value is in the range of the cortical bone fracture toughness. Lastly, the increase of the CfSWCNTs content results to decrease of the fracture toughness, and formation of secondary phases.

  1. Improvement of the fracture toughness of hydroxyapatite (HAp) by incorporation of carboxyl functionalized single walled carbon nanotubes (CfSWCNTs) and nylon

    DOE PAGESBeta

    Khanal, Suraj P.; Mahfuz, Hassan; Rondinone, Adam Justin; Leventouri, Th.

    2015-11-12

    The potential of improving the fracture toughness of synthetic hydroxyapatite (HAp) by incorporating carboxyl functionalized single walled carbon nanotubes (CfSWCNTs) and polymerized ε-caprolactam (nylon) was researched. A series of HAp samples with CfSWCNTs concentrations varying from 0 to 1.5 wt.%, without, and with nylon addition was prepared. X-ray diffraction (XRD), Scanning Electron Microscopy (SEM), and Transmission Electron Microscopy (TEM) were used to characterize the samples. The three point bending test was applied to measure the fracture toughness of the composites. A reproducible value of 3.6 ± 0.3 MPa.√m was found for samples containing 1 wt.% CfSWCNTs and nylon. This valuemore » is in the range of the cortical bone fracture toughness. Lastly, the increase of the CfSWCNTs content results to decrease of the fracture toughness, and formation of secondary phases.« less

  2. BUMPERII - DESIGN ANALYSIS CODE FOR OPTIMIZING SPACECRAFT SHIELDING AND WALL CONFIGURATION FOR ORBITAL DEBRIS AND METEOROID IMPACTS

    NASA Technical Reports Server (NTRS)

    Hill, S. A.

    1994-01-01

    BUMPERII is a modular program package employing a numerical solution technique to calculate a spacecraft's probability of no penetration (PNP) from man-made orbital debris or meteoroid impacts. The solution equation used to calculate the PNP is based on the Poisson distribution model for similar analysis of smaller craft, but reflects the more rigorous mathematical modeling of spacecraft geometry, orientation, and impact characteristics necessary for treatment of larger structures such as space station components. The technique considers the spacecraft surface in terms of a series of flat plate elements. It divides the threat environment into a number of finite cases, then evaluates each element of each threat. The code allows for impact shielding (shadowing) of one element by another in various configurations over the spacecraft exterior, and also allows for the effects of changing spacecraft flight orientation and attitude. Four main modules comprise the overall BUMPERII package: GEOMETRY, RESPONSE, SHIELD, and CONTOUR. The GEOMETRY module accepts user-generated finite element model (FEM) representations of the spacecraft geometry and creates geometry databases for both meteoroid and debris analysis. The GEOMETRY module expects input to be in either SUPERTAB Universal File Format or PATRAN Neutral File Format. The RESPONSE module creates wall penetration response databases, one for meteoroid analysis and one for debris analysis, for up to 100 unique wall configurations. This module also creates a file containing critical diameter as a function of impact velocity and impact angle for each wall configuration. The SHIELD module calculates the PNP for the modeled structure given exposure time, operating altitude, element ID ranges, and the data from the RESPONSE and GEOMETRY databases. The results appear in a summary file. SHIELD will also determine the effective area of the components and the overall model, and it can produce a data file containing the probability

  3. Removal of PCB-DNAPL from a rough-walled fracture using alcohol/polymer flooding

    NASA Astrophysics Data System (ADS)

    Gauthier, M.; Kueper, B. H.

    2006-03-01

    Phase behaviour experiments employing PCB (Aroclor 1242)/alcohol/water systems were conducted with ethanol (EtOH) and n-propanol (nPA). Both exhibited an affinity for the aqueous phase within the entire two-phase region. As much as 88% by volume (88% vol.) EtOH and 80% vol. nPA were necessary to achieve full miscibility of the PCB in the aqueous phase. DNAPL-water interfacial tension (IFT) was reduced from 38.9 dyn/cm to 4.7 dyn/cm and 2.4 dyn/cm with 80% vol. EtOH and 76% vol. nPA. The addition of alcohol brought about 41% and 54% reductions in DNAPL viscosity at maximal concentrations of EtOH and nPA. Density of the PCB-DNAPL was relatively unaffected by the presence of alcohol. A series of seven experiments were conducted where successive slugs of nPA and xanthan gum polymer solutions were injected into a fractured shale sample. A 30% vol. nPA solution injected under a hydraulic gradient of 0.36 allowed enhanced PCB removal primarily through reduction of IFT and resulted in 72% DNAPL recovery. Several pore volumes of alcohol solution were necessary to displace all the potentially mobile non-wetting phase since the high-viscosity DNAPL was mobilized at a lower flow rate than the overall fluid velocity, illustrating non-piston displacement. The injection of a 95% vol. nPA alcohol solution, theoretically at a sufficient concentration to produce fully miscible displacement of the residual DNAPL at equilibrium, resulted in non-equilibrium partitioning of the PCB into the flushing solution, likely due to the high fluid velocities in the fracture. The injection of 200 pore volumes of 95% vol. nPA solution resulted in 94% DNAPL recovery. Alcohol floods operated below the miscibility envelope appear to be a valuable source zone remedial alternative where the objective is to reduce DNAPL mobility to zero, but it should be noted that DNAPL mobility is increased during the application of the technology and steps may need to be taken to prevent unwanted vertical mobilization.

  4. Removal of PCB-DNAPL from a rough-walled fracture using alcohol/polymer flooding.

    PubMed

    Gauthier, M; Kueper, B H

    2006-03-01

    Phase behaviour experiments employing PCB (Aroclor 1242)/alcohol/water systems were conducted with ethanol (EtOH) and n-propanol (nPA). Both exhibited an affinity for the aqueous phase within the entire two-phase region. As much as 88% by volume (88% vol.) EtOH and 80% vol. nPA were necessary to achieve full miscibility of the PCB in the aqueous phase. DNAPL-water interfacial tension (IFT) was reduced from 38.9 dyn/cm to 4.7 dyn/cm and 2.4 dyn/cm with 80% vol. EtOH and 76% vol. nPA. The addition of alcohol brought about 41% and 54% reductions in DNAPL viscosity at maximal concentrations of EtOH and nPA. Density of the PCB-DNAPL was relatively unaffected by the presence of alcohol. A series of seven experiments were conducted where successive slugs of nPA and xanthan gum polymer solutions were injected into a fractured shale sample. A 30% vol. nPA solution injected under a hydraulic gradient of 0.36 allowed enhanced PCB removal primarily through reduction of IFT and resulted in 72% DNAPL recovery. Several pore volumes of alcohol solution were necessary to displace all the potentially mobile non-wetting phase since the high-viscosity DNAPL was mobilized at a lower flow rate than the overall fluid velocity, illustrating non-piston displacement. The injection of a 95% vol. nPA alcohol solution, theoretically at a sufficient concentration to produce fully miscible displacement of the residual DNAPL at equilibrium, resulted in non-equilibrium partitioning of the PCB into the flushing solution, likely due to the high fluid velocities in the fracture. The injection of 200 pore volumes of 95% vol. nPA solution resulted in 94% DNAPL recovery. Alcohol floods operated below the miscibility envelope appear to be a valuable source zone remedial alternative where the objective is to reduce DNAPL mobility to zero, but it should be noted that DNAPL mobility is increased during the application of the technology and steps may need to be taken to prevent unwanted vertical mobilization

  5. Canal wall reconstruction and mastoid obliteration with composite multi-fractured osteoperiosteal flap.

    PubMed

    Uçar, Cevat

    2006-12-01

    We used inferior pedicled composite multi-fractured osteoperiosteal flap (CMOF), our original and new surgical approach, to obliterate the mastoid cavity and reconstruct the external auditory canal (EAC) to prevent the open cavity problems. CMOF was used to obliterate the mastoid cavity and reconstruct the EAC in 24 patients (13 women, 11 men; age span 12-51 years) who underwent radical mastoidectomy to treat the chronic otitis media between 1998 and 2004. Small meatoplasty was done in all 24 patients to relieve their aesthetical concerns. Temporal bone CT scanning was done to observe the neo-osteogenesis in the mastoidectomy cavity and the CMOF, and the EAC volume was measured postoperatively. All our patients were followed-up for 2 years. The epithelization of the new EAC in our patients was complete at the end of the second month. Cholesteatoma, granulation, and recurrence of osteitis did not occur in any of the patients. We saw the new bone formation filling the mastoid cavity in the postoperative temporal bone CT scanning images. The mean volume of the new EAC on the 24th month was 1.83 +/- 0.56 cm(3). We had an almost natural EAC, which owed its existence to the neo-osteogenesis that grows behind the CMOF, which we use to obliterate the mastoid cavity and to reconstruct the EAC. PMID:17006636

  6. A Study On Critical Thinning In Thin-walled Tube Bending Of Al-Alloy 5052O Via Coupled Ductile Fracture Criteria

    SciTech Connect

    Li Heng; Yang He; Zhan Mei

    2010-06-15

    Thin-walled tube bending(TWTB) method of Al-alloy tube has attracted wide applications in aerospace, aviation and automobile,etc. While, under in-plane double tensile stress states at the extrados of bending tube, the over-thinning induced ductile fracture is one dominant defect in Al-alloy tube bending. The main objective of this study is to predict the critical wall-thinning of Al-alloy tube bending by coupling two ductile fracture criteria(DFCs) into FE simulation. The DFCs include Continuum Damage Mechanics(CDM)-based model and GTN porous model. Through the uniaxial tensile test of the curved specimen, the basic material properties of the Al-alloy 5052O tube is obtained; via the inverse problem solution, the damage parameters of both the two fracture criteria are interatively determined. Thus the application study of the above DFCs in the TWTB is performed, and the more reasonable one is selected to obtain the critical thinning of Al-alloy tube in bending. The virtual damage initiation and evolution (when and where the ductile fracture occurs) in TWTB are investigated, and the fracture mechanisms of the voided Al-alloy tube in tube bending are consequently discussed.

  7. Models of Lithospheric Flexure and Outer Trench Wall Fracturing using an Iterative Spectral Method

    NASA Astrophysics Data System (ADS)

    Garcia, E. S. M.; Sandwell, D. T.

    2014-12-01

    We have developed and tested an iterative spectral solution technique for flexure of thin elastic plates having continuously varying rigidity in both horizontal directions. This novel method was used to model oceanic lithosphere bending seaward of deep-sea trenches. In our formulation, the various mechanical loads that lead to plate flexure are simulated as applied bending moments and vertical forces acting on an arbitrary trench planform. Another input required by our model is a grid of flexural rigidity covering the plate domain laterally. We developed a procedure for estimating the rigidity from the plate age and curvature. With the loading and rigidity as input, the iterative spectral method gives the plate deflection as output. The plate curvature is then recalculated to obtain updated values of the rigidity, from which a new deflection grid is produced. These computations proceed iteratively until convergence is achieved. For our parameter estimation problem, we sought to find values of applied moments and vertical loads that produce a plate deflection surface which matches the seafloor bathymetry from ship soundings and marine gravity from satellite altimetry. By referring to a yield strength envelope formulation, we can take the modeled deflection surface and predict the lateral distribution of brittle failure at the bent areas of the plate. If we consider optimally-oriented faults according to an assumed value of the friction coefficient, we find that the upper layer of the plate undergoing brittle failure deepens with increasing proximity to the trench. We conducted tests for our modeling approach on an outer rise region adjacent to the South American Trench. Our preliminary results suggest a correspondence between the prevalence of surface fractures observed in high-resolution bathymetry with model predictions of brittle failure extending more than 10 kilometers deep into the plate.

  8. Analytical Modeling of Pressure Wall Hole Size and Maximum Tip-to-Tip Crack Length for Perforating Normal and Oblique Orbital Debris Impacts

    NASA Technical Reports Server (NTRS)

    Schonberg, William P.; Mohamed, Essam

    1997-01-01

    This report presents the results of a study whose objective was to develop first-principles-based models of hole size and maximum tip-to-tip crack length for a spacecraft module pressure wall that has been perforated in an orbital debris particle impact. The hole size and crack length models are developed by sequentially characterizing the phenomena comprising the orbital debris impact event, including the initial impact, the creation and motion of a debris cloud within the dual-wall system, the impact of the debris cloud on the pressure wall, the deformation of the pressure wall due to debris cloud impact loading prior to crack formation, pressure wall crack initiation, propagation, and arrest, and finally pressure wall deformation following crack initiation and growth. The model development has been accomplished through the application of elementary shock physics and thermodynamic theory, as well as the principles of mass, momentum, and energy conservation. The predictions of the model developed herein are compared against the predictions of empirically-based equations for hole diameters and maximum tip-to-tip crack length for three International Space Station wall configurations. The ISS wall systems considered are the baseline U.S. Lab Cylinder, the enhanced U.S. Lab Cylinder, and the U.S. Lab Endcone. The empirical predictor equations were derived from experimentally obtained hole diameters and crack length data. The original model predictions did not compare favorably with the experimental data, especially for cases in which pressure wall petalling did not occur. Several modifications were made to the original model to bring its predictions closer in line with the experimental results. Following the adjustment of several empirical constants, the predictions of the modified analytical model were in much closer agreement with the experimental results.

  9. Spin-orbit-coupling induced torque in ballistic domain walls: Equivalence of charge-pumping and nonequilibrium magnetization formalisms

    NASA Astrophysics Data System (ADS)

    Yuan, Zhe; Kelly, Paul J.

    2016-06-01

    To study the effect of spin-orbit coupling (SOC) on spin-transfer torque in magnetic materials, we have implemented two theoretical formalisms that can accommodate SOC. Using the "charge-pumping" formalism, we find two contributions to the out-of-plane spin-transfer torque parameter β in ballistic Ni domain walls (DWs). For short DWs, the nonadiabatic reflection of conduction electrons caused by the rapid spatial variation of the exchange potential results in an out-of-plane torque that increases rapidly with decreasing DW length. For long DWs, the Fermi level conduction channel anisotropy that gives rise to an intrinsic DW resistance in the presence of SOC leads to a linear dependence of β on the DW length. To understand this counterintuitive divergence of β in the long DW limit, we use the "nonequilibrium magnetization" formalism to examine the spatially resolved spin-transfer torque. The SOC-induced out-of-plane torque in ballistic DWs is found to be quantitatively consistent with the values obtained using the charge-pumping calculations, indicating the equivalence of the two theoretical methods.

  10. Non-perturbative modelling of energetic particle effects on resistive wall mode: Anisotropy and finite orbit width

    SciTech Connect

    Liu, Yueqiang Chapman, I. T.; Hao, G. Z.; Wang, Z. R.; Menard, J. E.; Okabayashi, M.; Strait, E. J.; Turnbull, A.

    2014-05-15

    A non-perturbative magnetohydrodynamic-kinetic hybrid formulation is developed and implemented into the MARS-K code [Liu et al., Phys. Plasmas 15, 112503 (2008)] that takes into account the anisotropy and asymmetry [Graves et al., Nature Commun. 3, 624 (2012)] of the equilibrium distribution of energetic particles (EPs) in particle pitch angle space, as well as first order finite orbit width (FOW) corrections for both passing and trapped EPs. Anisotropic models, which affect both the adiabatic and non-adiabatic drift kinetic energy contributions, are implemented for both neutral beam injection and ion cyclotron resonant heating induced EPs. The first order FOW correction does not contribute to the precessional drift resonance of trapped particles, but generally remains finite for the bounce and transit resonance contributions, as well as for the adiabatic contributions from asymmetrically distributed passing particles. Numerical results for a 9MA steady state ITER plasma suggest that (i) both the anisotropy and FOW effects can be important for the resistive wall mode stability in ITER plasmas; and (ii) the non-perturbative approach predicts less kinetic stabilization of the mode, than the perturbative approach, in the presence of anisotropy and FOW effects for the EPs. The latter may partially be related to the modification of the eigenfunction of the mode by the drift kinetic effects.

  11. Comparison of Absorbable Mesh Plate versus Titanium-Dynamic Mesh Plate in Reconstruction of Blow-Out Fracture: An Analysis of Long-Term Outcomes

    PubMed Central

    Baek, Woon Il; Kim, Woo Seob; Bae, Tae Hui

    2014-01-01

    Background A blow-out fracture is one of the most common facial injuries in midface trauma. Orbital wall reconstruction is extremely important because it can cause various functional and aesthetic sequelae. Although many materials are available, there are no uniformly accepted guidelines regarding material selection for orbital wall reconstruction. Methods From January 2007 to August 2012, a total of 78 patients with blow-out fractures were analyzed. 36 patients received absorbable mesh plates, and 42 patients received titanium-dynamic mesh plates. Both groups were retrospectively evaluated for therapeutic efficacy and safety according to the incidence of three different complications: enophthalmos, extraocular movement impairment, and diplopia. Results For all groups (inferior wall fracture group, medial wall fractrue group, and combined inferomedial wall fracture group), there were improvements in the incidence of each complication regardless of implant types. Moreover, a significant improvement of enophthalmos occurred for both types of implants in group 1 (inferior wall fracture group). However, we found no statistically significant differences of efficacy or complication rate in every groups between both implant types. Conclusions Both types of implants showed good results without significant differences in long-term follow up, even though we expected the higher recurrent enophthalmos rate in patients with absorbable plate. In conclusion, both types seem to be equally effective and safe for orbital wall reconstruction. In particular, both implant types significantly improve the incidence of enophthalmos in cases of inferior orbital wall fractures. PMID:25075357

  12. Pseudo-Orbital Apex Syndrome in the Acute Trauma Setting Due to Ipsilateral Dissection of Internal Carotid Artery.

    PubMed

    Anders, Ursula M; Taylor, Elise J; Martel, Joseph R; Martel, James B

    2016-01-01

    Traumatic causes of orbital apex and superior orbital fissure syndrome are uncommon. The authors present the first case of a traumatic superior orbital fissure syndrome simulating orbital apex syndrome, with loss of vision from posterior ischemic optic neuropathy. A 35-year-old man was initially felt to have a right orbital apex syndrome with left craniofacial and orbital trauma. CT revealed left orbital fractures, a right superior orbital fissure fracture, a retained metallic foreign body in the right sphenoid sinus, and a right frontoparietal subdural hematoma. CT angiography showed a secondary dissection and occlusion of the right internal carotid artery from osseous erosion of the posterolateral wall of the sphenoid sinus. Internal carotid artery dissection is a possible, though rare, cause of ischemic optic neuropathy. The right pseudo-orbital apex syndrome resulted from a mechanical superior orbital fissure syndrome and posterior ischemic optic neuropathy from an internal carotid artery dissection. PMID:25216200

  13. Assessment of the validity of Stokes and Reynolds equations for fluid flow through a rough-walled fracture with flow imaging

    NASA Astrophysics Data System (ADS)

    Lee, Seung Hyun; Lee, Kang-Kun; Yeo, In Wook

    2014-07-01

    Understanding fluid flow through a rough-walled fracture is important in many problems such as petroleum and geothermal reservoir exploitation, geological storage of CO2, and sitting of radioactive waste repositories. In order to advance the understanding of fracture flow, we conducted the first direct measurement of flow velocity across rough-walled fractures at Reynolds number (Re) of 0.014 to 0.086. The results were used for an order of magnitude analysis to evaluate assumptions underlying the Stokes and the Reynolds equations, which are derived from simplifying the Navier-Stokes equations. Even at very rough subregions, viscous forces were at least 2 orders of magnitude greater than inertial forces, indicating that the Stokes equations are valid for Re < 0.1. However, the assumption made in the derivation of the Reynolds equation that ∂2ux/∂z2 is dominant over other viscous terms was not satisfied even at moderate roughness for Re < 0.1. The Reynolds equation overestimated flow rate.

  14. Chest Wall Volume Receiving >30 Gy Predicts Risk of Severe Pain and/or Rib Fracture After Lung Stereotactic Body Radiotherapy

    SciTech Connect

    Dunlap, Neal E.; Cai, Jing; Biedermann, Gregory B.; Yang, Wensha; Benedict, Stanley H.; Sheng Ke; Schefter, Tracey E.; Kavanagh, Brian D.; Larner, James M.

    2010-03-01

    Purpose: To identify the dose-volume parameters that predict the risk of chest wall (CW) pain and/or rib fracture after lung stereotactic body radiotherapy. Methods and Materials: From a combined, larger multi-institution experience, 60 consecutive patients treated with three to five fractions of stereotactic body radiotherapy for primary or metastatic peripheral lung lesions were reviewed. CW pain was assessed using the Common Toxicity Criteria for pain. Peripheral lung lesions were defined as those located within 2.5 cm of the CW. A minimal point dose of 20 Gy to the CW was required. The CW volume receiving >=20, >=30, >=40, >=50, and >=60 Gy was determined and related to the risk of CW toxicity. Results: Of the 60 patients, 17 experienced Grade 3 CW pain and five rib fractures. The median interval to the onset of severe pain and/or fracture was 7.1 months. The risk of CW toxicity was fitted to the median effective concentration dose-response model. The CW volume receiving 30 Gy best predicted the risk of severe CW pain and/or rib fracture (R{sup 2} = 0.9552). A volume threshold of 30 cm{sup 3} was observed before severe pain and/or rib fracture was reported. A 30% risk of developing severe CW toxicity correlated with a CW volume of 35 cm{sup 3} receiving 30 Gy. Conclusion: The development of CW toxicity is clinically relevant, and the CW should be considered an organ at risk in treatment planning. The CW volume receiving 30 Gy in three to five fractions should be limited to <30 cm{sup 3}, if possible, to reduce the risk of toxicity without compromising tumor coverage.

  15. Fractured Craters on Ganymede

    NASA Technical Reports Server (NTRS)

    1997-01-01

    Two highly fractured craters are visible in this high resolution image of Jupiter's moon, Ganymede. NASA's Galileo spacecraft imaged this region as it passed Ganymede during its second orbit through the Jovian system. North is to the top of the picture and the sun illuminates the surface from the southeast. The two craters in the center of the image lie in the ancient dark terrain of Marius Regio, at 40 degrees latitude and 201 degrees longitude, at the border of a region of bright grooved terrain known as Byblus Sulcus (the eastern portion of which is visible on the left of this image). Pervasive fracturing has occurred in this area that has completely disrupted these craters and destroyed their southern and western walls. Such intense fracturing has occurred over much of Ganymede's surface and has commonly destroyed older features. The image covers an area approximately 26 kilometers (16 miles) by 18 kilometers (11 miles) across at a resolution of 86 meters (287 feet) per picture element. The image was taken on September 6, 1996 by the solid state imaging (CCD) system on NASA's Galileo spacecraft.

    The Jet Propulsion Laboratory, Pasadena, CA manages the Galileo mission for NASA's Office of Space Science, Washington, DC. JPL is an operating division of California Institute of Technology (Caltech).

    This image and other images and data received from Galileo are posted on the World Wide Web, on the Galileo mission home page at URL http://galileo.jpl.nasa.gov.

  16. Limited-interval definitions of the photometric functions of lunar crater walls by photography from orbiting Apollo

    USGS Publications Warehouse

    Wildey, R.L.

    1971-01-01

    By the use of only relative photometry (intraframe) it is shown that the photometric functions of material reposed on the inner walls of some of the ypunger lunar craters photographed on the far side of the Moon from the Apollo 11 Command Module are not of a form which can be reduced to a dependence on phase angle and brightness-longitude (g, ??) alone. Some other dependence on the completely general degrees of freedom described by phase angle, angle of incidence, and angle of emergence (g, i, ??{lunate}) seems to be required. In addition, however, it has been found that a dependence of g and ?? is more closely approached for the crater, in the group observed, which is obviously the oldest by virtue of the roundedness of the rim crest and the mass-wasting which has occured on its inner walls. The possibility thus arises of crater age-dating by making a brightness ratio measurement together with some image geometry measurements. It is at least evident that more than one type of geologic material has been encountered. ?? 1971.

  17. High efficiency of the spin-orbit torques induced domain wall motion in asymmetric interfacial multilayered Tb/Co wires

    SciTech Connect

    Bang, Do; Awano, Hiroyuki

    2015-05-07

    We investigated current-induced DW motion in asymmetric interfacial multilayered Tb/Co wires for various thicknesses of magnetic and Pt-capping layers. It is found that the driving mechanism for the DW motion changes from interfacial to bulk effects at much thick magnetic layer (up to 19.8 nm). In thin wires, linearly depinning field dependence of critical current density and in-plane field dependence of DW velocity suggest that the extrinsic pinning governs field-induced DW motion and injecting current can be regarded as an effective field. It is expected that the high efficiency of spin-orbit torques in thick magnetic multilayers would have important implication for future spintronic devices based on in-plane current induced-DW motion or switching.

  18. Orbital trauma and its impact on the heart

    PubMed Central

    Borumandi, Farzad; Rippel, Christian; Gaggl, Alexander

    2014-01-01

    We present the case of a 16-year-old boy, who was hit in the right orbital region during a soccer match. Immediately after the blow, the patient felt nauseous and fell to the ground. The otherwise healthy patient presented with headache, nausea and sinus bradycardia (38 bpm). Clinically there were no obvious signs of fracture of facial bones. There was no sign of injury to the eyes, only the right globe was slightly restricted in movement. With suspicion of head injury, a CT scan was performed revealing a trapdoor fracture of the medial orbital wall. The medial rectus muscle was entrapped within the fracture inducing the oculocardiac reflex. The trapped rectus muscle was released endoscopically on the same day and the heart rate normalised. Early surgical intervention is recommended to avoid prolonged muscle ischaemia and to shorten the vagal symptoms. PMID:24810440

  19. An analysis of pure blowout fractures and associated ocular symptoms.

    PubMed

    Shin, Jun Woo; Lim, Jin Soo; Yoo, Gyeol; Byeon, Jun Hee

    2013-05-01

    Blowout fractures are one of the commonly occurring facial bone fractures and clinically important, as they may cause serious complications such as diplopia, extraocular movement limitation, and enophthalmos. The purpose of this study was to evaluate the current patient demographics and surgical outcomes of 952 pure blowout fractures from 2 hospitals of the Catholic University of Korea, from 2003 to 2011. The medical records were reviewed according to the cause, fracture site, ocular symptoms, time of operation, and sequela. Male patients outnumbered female patients, and blowout fractures were most often seen in 21- to 30-year-old men. The most common cause was violent assault (40.7%). The medial orbital wall (45.8%) was the most common site, followed by floor (29.4%) and inferomedial wall (24.6%). The most common ocular injury was hyphema. Diplopia was presented in 27.6%; extraocular movement limitation was detected in 12.8% patients, and enophthalmos was encountered in 3.4% patients. Diplopia, extraocular movement limitation, and enophthalmos were significantly improved by surgical repair (P < 0.05). Postoperative complications were persistent diplopia (1.6%) and enophthalmos (0.4%). We surveyed a large series of blowout fracture in the Republic of Korea and recommend this study to serve as an important guideline in treating pure blowout fractures. PMID:23714863

  20. Nose fracture

    MedlinePlus

    Fracture of the nose; Broken nose; Nasal fracture; Nasal bone fracture; Nasal septal fracture ... A fractured nose is the most common fracture of the face. It ... with other fractures of the face. Sometimes a blunt injury can ...

  1. Summary and interpretation of dye-tracer tests to investigate the hydraulic connection of fractures at a ridge-and-valley-wall site near Fishtrap Lake, Pike County, Kentucky

    USGS Publications Warehouse

    Taylor, C.J.

    1994-01-01

    Dye-tracer tests were done during 1985-92 to investigate the hydraulic connection between fractures in Pennsylvanian coal-bearing strata at a ridge-and-valley-wall site near Fishtrap Lake, Pike County, Ky. Fluorescent dye was injected into a core hole penetrating near-surface and mining- induced fractures near the crest of the ridge. The rate and direction of migration of dye in the subsurface were determined by measuring the relative concentration of dye in water samples collected from piezometers completed in conductive fracture zones and fractured coal beds at various stratigraphic horizons within the ridge. Dye-concentration data and water-level measurements for each piezometer were plotted as curves on dye- recovery hydrographs. The dye-recovery hydrographs were used to evaluate trends in the fluctuation of dye concentrations and hydraulic heads in order to identify geologic and hydrologic factors affecting the subsurface transport of dye. The principal factors affecting the transport of dye in the subsurface hydrologic system were determined to be (1) the distribution, interconnection, and hydraulic properties of fractures; (2) hydraulic-head conditions in the near-fracture zone at the time of dye injection; and (3) subsequent short- and long-term fluctuations in recharge to the hydrologic system. In most of the dye-tracer tests, dye-recovery hydrographs are characterized by complex, multipeaked dye-concentration curves that are indicative of a splitting of dye flow as ground water moved through fractures. Intermittent dye pulses (distinct upward spikes in dye concentration) mark the arrivals of dye-labeled water to piezometers by way of discrete fracture-controlled flow paths that vary in length, complexity, and hydraulic conductivity. Dye injections made during relatively high- or increasing-head conditions resulted in rapid transport of dye (within several days or weeks) from near-surface fractures to piezometers. Injections made during relatively low- or

  2. Nose fracture

    MedlinePlus

    Fracture of the nose; Broken nose; Nasal fracture; Nasal bone fracture; Nasal septal fracture ... A fractured nose is the most common fracture of the face. It usually occurs after an injury and often occurs with ...

  3. Skull fracture

    MedlinePlus

    Basilar skull fracture; Depressed skull fracture; Linear skull fracture ... Skull fractures may occur with head injuries . The skull provides good protection for the brain. However, a severe impact ...

  4. Fracture detection logging tool

    DOEpatents

    Benzing, William M.

    1992-06-09

    A method and apparatus by which fractured rock formations are identified and their orientation may be determined includes two orthogonal motion sensors which are used in conjunction with a downhole orbital vibrator. The downhole vibrator includes a device for orienting the sensors. The output of the sensors is displayed as a lissajou figure. The shape of the figure changes when a subsurface fracture is encountered in the borehole. The apparatus and method identifies fractures rock formations and enables the azimuthal orientation of the fractures to be determined.

  5. Development and experimental evaluation of models for low capillary number two-phase flows in rough walled fractures relevant to natural gradient conditions

    SciTech Connect

    Glass, R.J.; Yarrington, L.; Nicholl, M.J.

    1997-09-01

    The major results from SNL`s Conceptual Model Development and Validation Task (WBS 1.2.5.4.6) as developed through exploration of small scale processes were synthesized in Glass et al. to give guidance to Performance Assessment on improving conceptual models for isothermal flow in unsaturated, fractured rock. There, pressure saturation and relative permeability curves for single fractures were proposed to be a function of both fracture orientation within the gravity field and initial conditions. We refer the reader to Glass et al. for a discussion of the implications of this behavior for Performance Assessment. The scientific research we report here substantiates this proposed behavior. We address the modeling of phase structure within fractures under natural gradient conditions relevant to unsaturated flow through fractures. This phase structure underlies the calculation of effective properties for individual fractures and hence fracture networks as required for Performance Assessment. Standard Percolation (SP) and Invasion Percolation (IP) approaches have been recently proposed to model the underlying phase saturation structures within the individual fractures during conditions of two-phase flow. Subsequent analysis of these structures yields effective two-phase pressure-saturation and relative permeability relations for the fracture. However, both of these approaches yield structures that are at odds with physical reality as we see in experiments and thus effective properties calculated from these structures are in error. Here we develop and evaluate a Modified Invasion Percolation (MIP) approach to better model quasi-static immiscible displacement in fractures. The effects of gravity, contact angle, local aperature field geometry, and local in-plane interfacial curvature between phases are included in the calculation of invasion pressure for individual sites in a discretized aperture field.

  6. Blowout Fracture after Descemet's Stripping Automated Endothelial Keratoplasty

    PubMed Central

    Tachibana, Eri; Koh, Shizuka; Maeda, Naoyuki; Nishida, Kohji

    2014-01-01

    We present the case of an 86-year-old woman who developed a blowout fracture after Descemet's stripping automated endothelial keratoplasty (DSAEK). Sixteen months after DSAEK, she suffered a blow to her left eye caused by a fall. Computed tomography confirmed the presence of a blowout fracture of the inferior wall of the left orbit with soft tissue prolapsing into the orbit. The patient complained of no abnormal symptoms, and her operated cornea was intact and clear. There was no abnormal finding in both the anterior and posterior segments. This case highlights that the DSAEK technique provides adequate tectonic stability of the globe throughout the traumatic event in contrast to penetrating keratoplasty, which can lead to devastating vision damage after trauma. PMID:25759661

  7. Blowout Fracture after Descemet's Stripping Automated Endothelial Keratoplasty.

    PubMed

    Tachibana, Eri; Koh, Shizuka; Maeda, Naoyuki; Nishida, Kohji

    2014-01-01

    We present the case of an 86-year-old woman who developed a blowout fracture after Descemet's stripping automated endothelial keratoplasty (DSAEK). Sixteen months after DSAEK, she suffered a blow to her left eye caused by a fall. Computed tomography confirmed the presence of a blowout fracture of the inferior wall of the left orbit with soft tissue prolapsing into the orbit. The patient complained of no abnormal symptoms, and her operated cornea was intact and clear. There was no abnormal finding in both the anterior and posterior segments. This case highlights that the DSAEK technique provides adequate tectonic stability of the globe throughout the traumatic event in contrast to penetrating keratoplasty, which can lead to devastating vision damage after trauma. PMID:25759661

  8. Waterflood-induced fractures

    SciTech Connect

    Dikken, B.J.; Niko, H.

    1987-01-01

    Fracturing occurs quite often in water injection wells, with sometimes unforeseen consequences on waterflood sweep efficiency. One of the causes of fracturing is often the cooling of hot formations by cold injection water. A special version of a thermal reservoir simulator for prototype applications has thus been constructed that is capable of dealing with propagating waterflood-induces hydraulic fractures. With this simulator, fracture propagation and the effect of growing fractures on the sweep efficiency are studied. Infinite fracture conductivity is assumed. The limitation to a very high leak-off fractures justifies disregarding the changes in fracture volume. Fracture growth is calculated using the concept of a critical stress intensity factor. Both poro- and thermo-elastic changes in the horizontal stresses are calculated numerically and their influence on the fracture initiation/propagation is continuously taken into account. In addition, a model of fracture wall impairment because of filter-cake build-up due to poor quality injection water is included. Results are presented for both thermal and isothermal situations. It is observed in isothermal cases that the voidage replacement ratio (volume balance during injection) determined to a great extent the length to which the fracture eventually may grow.

  9. [Diseases of the orbit].

    PubMed

    Lukasik, S; Betkowski, A; Cyran-Rymarz, A; Szuber, D

    1995-01-01

    Diseases of the orbital cavity require more attention because of its specific anatomic structure and placement. Their curing requires cooperation of many medical specialties. Analysis consider orbital fractures, mainly caused by car accidents (69.2%). The next half of them consider inflammatory processes and tumor in equal numbers. Malignant tumors of orbital cavity occur most frequently (48.0%), less frequent are pseudotumors--pseudotumor orbitae (36.0%) and rare--malignant ones (16.0%). Malignant tumors more frequently infiltrate the orbit in neighborhood (63.3%), less frequently they come out from orbit tissue (16.7%). It should be emphasized that the number of orbit inflammations decreases in subsequent years, whereas occurrence of orbit tumors increases. PMID:9454170

  10. Management of ocular, orbital, and adnexal trauma

    SciTech Connect

    Spoor, T.C.; Nesi, F.A.

    1988-01-01

    This book contains 20 chapters. Some of the chapter titles are: The Ruptured Globe: Primary Care; Corneal Trauma, Endophthalmitis; Antibiotic Usage; Radiology of Orbital Trauma; Maxillofacial Fractures; Orbital Infections; and Basic Management of Soft Tissue Injury.

  11. A Wrapping Method for Inserting Titanium Micro-Mesh Implants in the Reconstruction of Blowout Fractures

    PubMed Central

    Choi, Tae Joon; Yang, Won Yong; Kang, Sang Yoon

    2016-01-01

    Titanium micro-mesh implants are widely used in orbital wall reconstructions because they have several advantageous characteristics. However, the rough and irregular marginal spurs of the cut edges of the titanium mesh sheet impede the efficacious and minimally traumatic insertion of the implant, because these spurs may catch or hook the orbital soft tissue, skin, or conjunctiva during the insertion procedure. In order to prevent this problem, we developed an easy method of inserting a titanium micro-mesh, in which it is wrapped with the aseptic transparent plastic film that is used to pack surgical instruments or is attached to one side of the inner suture package. Fifty-four patients underwent orbital wall reconstruction using a transconjunctival or transcutaneous approach. The wrapped implant was easily inserted without catching or injuring the orbital soft tissue, skin, or conjunctiva. In most cases, the implant was inserted in one attempt. Postoperative computed tomographic scans showed excellent placement of the titanium micro-mesh and adequate anatomic reconstruction of the orbital walls. This wrapping insertion method may be useful for making the insertion of titanium micro-mesh implants in the reconstruction of orbital wall fractures easier and less traumatic. PMID:26848451

  12. A Wrapping Method for Inserting Titanium Micro-Mesh Implants in the Reconstruction of Blowout Fractures.

    PubMed

    Choi, Tae Joon; Burm, Jin Sik; Yang, Won Yong; Kang, Sang Yoon

    2016-01-01

    Titanium micro-mesh implants are widely used in orbital wall reconstructions because they have several advantageous characteristics. However, the rough and irregular marginal spurs of the cut edges of the titanium mesh sheet impede the efficacious and minimally traumatic insertion of the implant, because these spurs may catch or hook the orbital soft tissue, skin, or conjunctiva during the insertion procedure. In order to prevent this problem, we developed an easy method of inserting a titanium micro-mesh, in which it is wrapped with the aseptic transparent plastic film that is used to pack surgical instruments or is attached to one side of the inner suture package. Fifty-four patients underwent orbital wall reconstruction using a transconjunctival or transcutaneous approach. The wrapped implant was easily inserted without catching or injuring the orbital soft tissue, skin, or conjunctiva. In most cases, the implant was inserted in one attempt. Postoperative computed tomographic scans showed excellent placement of the titanium micro-mesh and adequate anatomic reconstruction of the orbital walls. This wrapping insertion method may be useful for making the insertion of titanium micro-mesh implants in the reconstruction of orbital wall fractures easier and less traumatic. PMID:26848451

  13. [Wooden spike orbital injury].

    PubMed

    Kiel, R; Wiaux, C; Atipo-Tsiba, P W; Gottrau, P de

    2005-03-01

    A 71-year-old female patient fell in her garden, inducing a skin wound on the temporal left eyebrow. Skin disinfection and wound closure were performed elsewhere, an X-ray image did not reveal a foreign body. She was referred to our service three days later with a progressive left periorbital swelling. Clinical inspection demonstrated a painfully, fluctuant swelling around the wound with an inflammatory pseudoptosis of the left eye. Vision was reduced on the left eye; anterior and posterior segments of both eyes were unharmed. After opening the wound sutures a purulent liquid was drained and a wooden fragment was found, measuring 22 x 0.5 mm. Because of restriction of abduction of the left eye, magnetic resonance imaging (MRI) was performed, detecting another organic intraorbital foreign body and a fracture of the left medial orbital wall. Anterior orbitotomy was performed and a wooden fragment was removed, measuring 47 x 0.6 mm. Under administration of intravenous antibiotics vision and ocular motility recovered uneventfully. This case emphasizes the value of MRI in the diagnostics of retained wooden foreign bodies as well as the importance of a soigneuse inspection of skin wounds with a high risk for remaining foreign bodies. PMID:15785993

  14. Fracture patterns in the maxillofacial region: a four-year retrospective study

    PubMed Central

    2015-01-01

    Objectives The facial bones are the most noticeable area in the human body, and facial injuries can cause significant functional, aesthetic, and psychological complications. Continuous study of the patterns of facial bone fractures and changes in trends is helpful in the prevention and treatment of maxillofacial fractures. The purpose of the current clinico-statistical study is to investigate the pattern of facial fractures over a 4-year period. Materials and Methods A retrospective analysis of 1,824 fracture sites was carried out in 1,284 patients admitted to SMG-SNU Boramae Medical Center for facial bone fracture from January 2010 to December 2013. We evaluated the distributions of age/gender/season, fracture site, cause of injury, duration from injury to treatment, hospitalization period, and postoperative complications. Results The ratio of men to women was 3.2:1. Most fractures occurred in individuals aged between teens to 40s and were most prevalent at the middle and end of the month. Fractures occurred in the nasal bone (65.0%), orbital wall (29.2%), maxillary wall (15.3%), zygomatic arch (13.2%), zygomaticomaxillary complex (9.8%), mandibular symphysis (6.5%), mandibular angle (5.9%), mandibular condyle (4.9%), and mandibular body (1.9%). The most common etiologies were fall (32.5%) and assault (26.0%). The average duration of injury to treatment was 6 days, and the average hospitalization period was 5 days. Eighteen postoperative complications were observed in 17 patients, mainly infection and malocclusion in the mandible. Conclusion This study reflects the tendency for trauma in the Seoul metropolitan region because it analyzes all facial fracture patients who visited our hospital regardless of the specific department. Distinctively, in this study, midfacial fractures had a much higher incidence than mandible fractures. PMID:26734557

  15. Comparison of pre-bent titanium mesh versus polyethylene implants in patient specific orbital reconstructions

    PubMed Central

    2013-01-01

    Introduction Computerized tomography DICOM file can be relatively easily transformed to a virtual 3D model. With the help of additional software we are able to create the mirrored model of an undamaged orbit and on this basis produce an individual implant for the patient Authors decided to apply implants with any thickness, which are authors own invention to obtain volumetric support and more stable orbital wall reconstruction outcome. Material of choice was ultra-high molecular weight polyethylene (UHMWPE). Objective The aim of this study was to present and compare functional results of individual reconstructions of orbital wall using either titanium mesh or ultra-high molecular weight polyethylene. Materials and methods 57 consecutive patients affected by orbital wall fracture (46 males, 11 females, mean age 34±14 year) were treated in Department of Maxillofacial Surgery from 2010 to 2012. In the first group we used patient specific treatment by titanium mesh shaped on a 3D printed model of a mirrored intact orbit (37 orbits) or by individually manufactured UHMW-PE implantby CAM milling in second group (20 orbits). All of these patients were subjected to preoperative helical computerized tomography and consultation of an ophthalmologist (including binocular single vision loss test - BSVL). Further on, patients were operated under general anaesthesia using transconjuctival approach. BSVL was again evaluated post-operationally in 1 month and 6 months later. Results Functional treatment results (BSVL) for both groups were similar in 1 month as well as 6 months post operational time. There was no statistically significant difference between these two groups. Conclusions This study of 6 months functional result assessment of pre-bent individual implants and CNC milled ultra-high molecular weight polyethylene of the orbital wall has shown it to be a predictable reconstruction method. Individually shaped UHMWPE seems to be as good as pre-bent titanium mesh. PMID

  16. Orbital emphysema following remote skull trauma.

    PubMed

    Brown, S M; Lissner, G

    1995-06-01

    In an unusual case of orbital emphysema following nose blowing, a reliable patient history and examination demonstrated no direct trauma to the orbit. Blunt posterior skull trauma was sustained several hours before the development of the orbital emphysema. A "seismic" transmittal of force to the orbital walls is postulated. PMID:7654620

  17. Fractured Surface

    NASA Technical Reports Server (NTRS)

    2005-01-01

    [figure removed for brevity, see original site] Context image for PIA03084 Fractured Surface

    These fractures and graben are part of Gordii Fossae, a large region that has undergone stresses which have cracked the surface.

    Image information: VIS instrument. Latitude 16.6S, Longitude 234.3E. 18 meter/pixel resolution.

    Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.

    NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.

  18. Late migration of an orbital implant causing orbital hemorrhage with sudden proptosis and diplopia.

    PubMed

    Rosen, C E

    1996-12-01

    A 31-year-old woman complained of sudden diplopia and proptosis associated with a headache. Approximately 10 years earlier, she had sustained a right orbital blowout fracture during a snow machine accident that was repaired using a Supramid implant. She presented with 4 mm of right-sided proptosis by Hertel exophthalmometry, with limitation of up and down gaze. She manifested a right gaze preference with a left head turn to achieve fusion. Visual acuity was 20/20 on both sides; however, there was 20% red desaturation and a subtle afferent pupillary defect on the right side. Goldmann visual fields were full and the retinal examination was normal. A computed tomography (CT) scan of the orbits with and without contrast demonstrated a large right posterior inferior orbital mass. Once the periorbita was breached during orbitotomy, a burgundy serosanguinous material emerged. Gram staining revealed red cells without organisms. The implant had not been fixed by wires or screws. Upon removal, the implant appeared oversized, encompassing the orbital floor, medial and lateral walls. Postoperatively, the proptosis, gaze preference with face turn, afferent pupillary defect, desaturation abnormality, and diplopia resolved. PMID:8944386

  19. Need for airbag and seatbelt to reduce orbital injuries from steering wheel knob.

    PubMed

    Hwang, Kun; Kim, Joo Ho

    2014-11-01

    The aims of this study are to report a blowout fracture of the orbital floor and medial wall caused by being struck by a steering wheel knob of an automobile and to discuss the use of airbags and seatbelts as a preventive measure for orbital injuries. A 58-year-old man was struck in the left eye by a steering wheel. His car hit a telephone pole, and he had a frontal collision injury. In this frontal impact, his left eye was hit by a Brodie knob attached to the steering wheel. At the time of injury, the speed of the car was about 65 km/h. He was not wearing a seatbelt, and the airbag had not deployed. Swelling and ecchymosis were observed at the left periorbital area, and he had diplopia on a left-side gaze. A CT revealed fractures in the medial and inferior wall of the left orbit. Entrapped soft tissues were reduced, and the medial wall and floor were reconstructed with a resorbable sheet. His diplopia disappeared 12 days after surgery. To prevent the injury from the steering wheel knob, an airbag should be installed in any vehicle, which has a steering wheel knob. Legislation mandating the use of airbags as well as seatbelts in vehicles with attached steering wheel knobs should be made. PMID:25376138

  20. Relative permeability through fractures

    SciTech Connect

    Diomampo, Gracel, P.

    2001-08-01

    The mechanism of two-phase flow through fractures is of importance in understanding many geologic processes. Currently, two-phase flow through fractures is still poorly understood. In this study, nitrogen-water experiments were done on both smooth and rough parallel plates to determine the governing flow mechanism for fractures and the appropriate methodology for data analysis. The experiments were done using a glass plate to allow visualization of flow. Digital video recording allowed instantaneous measurement of pressure, flow rate and saturation. Saturation was computed using image analysis techniques. The experiments showed that gas and liquid phases flow through fractures in nonuniform separate channels. The localized channels change with time as each phase path undergoes continues breaking and reforming due to invasion of the other phase. The stability of the phase paths is dependent on liquid and gas flow rate ratio. This mechanism holds true for over a range of saturation for both smooth and rough fractures. In imbibition for rough-walled fractures, another mechanism similar to wave-like flow in pipes was also observed. The data from the experiments were analyzed using Darcy's law and using the concept of friction factor and equivalent Reynold's number for two-phase flow. For both smooth- and rough-walled fractures a clear relationship between relative permeability and saturation was seen. The calculated relative permeability curves follow Corey-type behavior and can be modeled using Honarpour expressions. The sum of the relative permeabilities is not equal one, indicating phase interference. The equivalent homogeneous single-phase approach did not give satisfactory representation of flow through fractures. The graphs of experimentally derived friction factor with the modified Reynolds number do not reveal a distinctive linear relationship.

  1. Blow-Out Fracture due to a Hazel Stick Beat.

    PubMed

    Erbilen, Esin; Yuksel, Harun; Onder, H Ibrahim; Tunc, Murat; Kaya, Murat

    2008-12-01

    The aim of this case report is to demonstrate that blow-out fractures can occur not only by a classical trauma mechanism but also from the consequences of a stick beat. A 66-year-old male was admitted to our hospital complaining of a sudden swelling of his right eyelid after blowing his nose. In his medical history there was the report of a hazel stick beat the previous day. Upon ophthalmological examination, ecchymosis was observed in the right orbital region, and subcutaneous amphisema in addition to a dense subconjunctival hemorrhage were detected. Using computed tomography (CT), the intraorbital air density in the soft tissues and the right maxillary sinus wall fracture possessing fluid density compatible with hemorrhage was observed. The patient was treated conservatively with prednisolone and antibiotics. We conclude that a blow-out fracture may occur in patients who experience orbital trauma, even in cases of low-energy trauma. These patients may be symptomatic after an episode of hard nose-blowing. PMID:25610052

  2. Subbrow Approach as a Minimally Invasive Reduction Technique in the Management of Frontal Sinus Fractures

    PubMed Central

    Lee, Yewon; Shin, Dong Hyeok; Uhm, Ki Il; Kim, Soon Heum; Kim, Cheol Keun; Jo, Dong In

    2014-01-01

    Background Frontal sinus fractures, particularly anterior sinus fractures, are relatively common facial fractures. Many agree on the general principles of frontal fracture management; however, the optimal methods of reduction are still controversial. In this article, we suggest a simple reduction method using a subbrow incision as a treatment for isolated anterior sinus fractures. Methods Between March 2011 and March 2014, 13 patients with isolated frontal sinus fractures were treated by open reduction and internal fixation through a subbrow incision. The subbrow incision line was designed to be precisely at the lower margin of the brow in order to obtain an inconspicuous scar. A periosteal incision was made at 3 mm above the superior orbital rim. The fracture site of the frontal bone was reduced, and bone fixation was performed using an absorbable plate and screws. Results Contour deformities were completely restored in all patients, and all patients were satisfied with the results. Scars were barely visible in the long-term follow-up. No complications related to the procedure, such as infection, uncontrolled sinus bleeding, hematoma, paresthesia, mucocele, or posterior wall and brain injury were observed. Conclusions The subbrow approach allowed for an accurate reduction and internal fixation of the fractures in the anterior table of the frontal sinus by providing a direct visualization of the fracture. Considering the surgical success of the reduction and the rigid fixation, patient satisfaction, and aesthetic problems, this transcutaneous approach through a subbrow incision is concluded to be superior to the other reduction techniques used in the case of an anterior table frontal sinus fracture. PMID:25396180

  3. Clinical outcome following use of transconjunctival approach in reducing orbitozygomaticomaxillary complex fractures

    PubMed Central

    Kumar, Saurabh; Shubhalaksmi, S.

    2016-01-01

    Background: The increasing emphasis on the open reduction and internal fixation of orbito-zygomatico-maxillary complex fractures has led to a more critical appraisal of the various surgical approaches to the orbital and zygomatic skeleton. Transconjunctival approach popularized by Tessier although credited to Bourquet in 1924 offer excellent exposure of the orbito-zygomatico-maxillary complex fracture especially the infra-orbital rim, frontozygomatic suture and the orbital floor. The argument against a transconjunctival access focuses primarily on concern about limited exposure that apparently makes accurate reduction and osteosynthesis of displaced fracture fragments difficult or impossible. Also, due to close association with eye and various ocular complications reported in the literature, most of the surgeons feel skeptical about using this approach. Aim: The aim of this study is to analyze the efficacy of transconjunctival approach in the treatment of orbito-zygomatico-maxillary complex fractures by evaluating the functional and esthetic results and its associated complications. Material and Method: We report a series of eight patients who have undergone fracture repair of the orbito-zygomatico-maxillary complex via a transconjunctival approach. Postoperative patient evaluation was performed with specific attention paid towards wound healing, functional stability, esthetic appearance and postoperative ocular complications. Postoperatively clinical examination along with radiographic examination was done to evaluate the position of the zygoma and determine the adequacy of fracture reduction. Results: In all the patients excellent surgical exposure has been achieved for reduction and rigid fixation of the fracture fragments. None of the patients had any form of complication related to the approach. There were no postoperative ocular complications. Only one patient had postoperative chemosis which was transient and subsided subsequently. All the patients had

  4. Orbit to orbit transportation

    NASA Technical Reports Server (NTRS)

    Bergeron, R. P.

    1980-01-01

    Orbital transfer vehicle propulsion options for SPS include both chemical (COTV) and electrical (EOTV) options. The proposed EOTV construction method is similar to that of the SPS and, by the addition of a transmitting antenna, may serve as a demonstration or precursor satellite option. The results of the studies led to the selection of a single stage COTV for crew and priority cargo transfer. An EOTV concept is favored for cargo transfer because of the more favorable orbital burden factor over chemical systems. The gallium arsenide solar array is favored over the silicon array because of its self annealing characteristics of radiation damage encountered during multiple transitions through the Van Allen radiation belt. Transportation system operations are depicted. A heavy lift launch vehicle (HLLV) delivers cargo and propellants to LEO, which are transferred to a dedicated EOTV by means of an intraorbit transfer vehicle (IOTV) for subsequent transfer to GEO. The space shuttle is used for crew transfer from Earth to LEO. At the LEO base, the crew module is removed from the shuttle cargo bay and mated to a COTV for transfer to GEO. Upon arrival at GEO, the SPS construction cargo is transferred from the EOTV to the SPS construction base by IOTV. Crew consumables and resupply propellants are transported to GEO by the EOTV. Transportation requirements are dominated by the vast quantity of materials to be transported to LEO and GEO.

  5. Elbow Fractures

    MedlinePlus

    ... and held together with pins and wires or plates and screws. Fractures of the distal humerus (see ... doctor. These fractures usually require surgical repair with plates and/or screw, unless they are stable. SIGNS ...

  6. Olecranon Fractures.

    PubMed

    Brolin, Tyler J; Throckmorton, Thomas

    2015-11-01

    Olecranon fractures are common upper extremity injuries, with all but nondisplaced fractures treated surgically. There has been a recent shift in the surgical management of these fractures from tension band wiring to locking plate fixation and intramedullary nailing; however, this comes with increased implant cost. Although most patients can expect good outcomes after these various techniques, there is little information to guide a surgeon's treatment plan. This article reviews the epidemiology, classification, treatment, and outcomes of olecranon fractures. PMID:26498547

  7. Orbital pseudotumor

    MedlinePlus

    ... Names Idiopathic orbital inflammatory syndrome (IOIS) Images Skull anatomy References Goodlick TA, Kay MD, Glaser JS, Tse DT, Chang WJ. Orbital disease and neuro-ophthalmology. In: Tasman W, Jaeger EA, eds. Duane’s ...

  8. Kepler's Orbit

    NASA Video Gallery

    Kepler does not orbit the Earth, rather it orbits the Sun in concert with the Earth, slowly drifting away from Earth. Every 61 Earth years, Kepler and Earth will pass by each other. Throughout the ...

  9. Orbital cellulitis

    MedlinePlus

    ... Haemophilus influenzae B) vaccine. The bacteria Staphylococcus aureus , Streptococcus pneumoniae , and beta-hemolytic streptococci may also cause orbital cellulitis. Orbital cellulitis infections in children may get worse very quickly and can lead ...

  10. Patterns of Fracture and Tidal Stresses Due to Nonsynchronous Rotation: Implications for Fracturing on Europa

    NASA Technical Reports Server (NTRS)

    Parmentier, E. M.; Helfenstein, P.

    1985-01-01

    Global lineaments on Europa were interpreted as fractures in an icy crust. A variety of lineament types were identified, which appear to form a systematic pattern on the surface. For a synchronously rotating body, the patterns of fractures observed could be produced by a combination of stresses due to orbital recession, orbital eccentricity, and internal contraction. However, it was recently suggested that the forced eccentricity of Europa's orbit may result in nonsynchronous rotation. The hypothesis that fractures in a thin icy crust may have formed in response to stresses resulting from nonsynchronous rotation is studied.

  11. Sports fractures.

    PubMed Central

    DeCoster, T. A.; Stevens, M. A.; Albright, J. P.

    1994-01-01

    Fractures occur in athletes and dramatically influence performance during competitive and recreational activities. Fractures occur in athletes as the result of repetitive stress, acute sports-related trauma and trauma outside of athletics. The literature provides general guidelines for treatment as well as a variety of statistics on the epidemiology of fractures by sport and level of participation. Athletes are healthy and motivated patients, and have high expectations regarding their level of function. These qualities make them good surgical candidates. Although closed treatment methods are appropriate for most sports fractures, an aggressive approach to more complicated fractures employing current techniques may optimize their subsequent performance. PMID:7719781

  12. Novel Surgical Approaches to the Orbit

    PubMed Central

    Campbell, Ashley A.; Grob, Seanna R.; Yoon, Michael K.

    2015-01-01

    Determining safe surgical access to the orbit can be difficult given the complex anatomy and delicacy of the orbital structures. When considering biopsy or removal of an orbital tumor or repair of orbital fractures, careful planning is required to determine the ideal approach. Traditionally, this has at times necessitated invasive procedures with large incisions and extensive bone removal. The purpose of this review was to present newly techniques and devices in orbital surgery that have been reported over the past decade, with aims to provide better exposure and/or minimally invasive approaches and to improve morbidity and/or mortality. PMID:26692713

  13. Spin-Orbit Caloritronics

    NASA Astrophysics Data System (ADS)

    Manchon, Aurelien; Ndiaye, Papa Birame; Moon, Jung-Hwan; Lee, Hyun-Woo; Lee, Kyung-Jin

    2014-03-01

    Utilizing spin-orbit coupling to enable the electrical manipulation of ferromagnets has recently attracted a considerable amount of interest. This spin-orbit torque appears in magnetic systems displaying inversion symmetry breaking. Another adjacent emerging topic, spin caloritronics, aims at exploiting magnonic spin currents driven by temperature gradients, allowing for the transmission of information and the control of magnetic domain walls. In this work, we demonstrate that a magnon flow generates torques on the local magnetization when subjected to Dzyaloshinskii-Moriya interaction (DMI) just as an electron flow generates torques when submitted to Rashba interaction. A direct consequence is the capability to control the magnetization direction of a homogeneous ferromagnet by applying a temperature gradient or local RF excitations. Merging the spin-orbit torques with spin caloritronics is rendered possible by the emergence of DMI in magnetic materials and opens promising avenues in the development of chargeless information technology.

  14. Alloplastic template fixation of blow-out fracture.

    PubMed

    Hwang, Kun; Kita, Yoko

    2002-07-01

    Alloplasts are widely used to reconstruct the orbital defects. The alloplastic material, however, is not uncommonly infected, displaced, and extruded, and forms an epithelial pseudocyst around it. To prevent the depressed fractured bone of the orbital floor from dropping down into the maxillary sinus, an en block fragment of the depressed fracture of the orbital floor was restored after being attached to an alloplastic sheet template which was fixed to the intact orbital floor. This procedure is simple and secure, and intramaxillary packing is not needed to buttress the depressed fractured bone into the sinus. PMID:12140413

  15. Hip fracture - discharge

    MedlinePlus

    Inter-trochanteric fracture repair - discharge; Subtrochanteric fracture repair - discharge; Femoral neck fracture repair - discharge; Trochanteric fracture repair - discharge; Hip pinning surgery - discharge

  16. Melt fracture revisited

    SciTech Connect

    Greenberg, J. M.

    2003-07-16

    In a previous paper the author and Demay advanced a model to explain the melt fracture instability observed when molten linear polymer melts are extruded in a capillary rheometer operating under the controlled condition that the inlet flow rate was held constant. The model postulated that the melts were a slightly compressible viscous fluid and allowed for slipping of the melt at the wall. The novel feature of that model was the use of an empirical switch law which governed the amount of wall slip. The model successfully accounted for the oscillatory behavior of the exit flow rate, typically referred to as the melt fracture instability, but did not simultaneously yield the fine scale spatial oscillations in the melt typically referred to as shark skin. In this note a new model is advanced which simultaneously explains the melt fracture instability and shark skin phenomena. The model postulates that the polymer is a slightly compressible linearly viscous fluid but assumes no slip boundary conditions at the capillary wall. In simple shear the shear stress {tau}and strain rate d are assumed to be related by d = F{tau} where F ranges between F{sub 2} and F{sub 1} > F{sub 2}. A strain rate dependent yield function is introduced and this function governs whether F evolves towards F{sub 2} or F{sub 1}. This model accounts for the empirical observation that at high shears polymers align and slide more easily than at low shears and explains both the melt fracture and shark skin phenomena.

  17. Fracture and Failure in Micro- and Nano-Scale

    NASA Astrophysics Data System (ADS)

    Charitidis, Costas A.

    Indentation and scratch in micro- and nano-scale are the most commonly used techniques for quantifying thin film and systems properties. Among them are different failure modes such as deformation, friction, fracture toughness, fatigue. Failure modes can be activated either by a cycle of indentation or by scratching of the samples to provide an estimation of the fracture toughness and interfacial fracture energies. In the present study, we report on the failure and fracture modes in two cases of engineering materials; that is transparent SiOx thin films onto poly(ethylene terephthalate) (PET) membranes and glass-ceramic materials. The SiOx/PET system meets the demands regarding scratch-resistance, wettability, biocompatibility, gas transmission, or friction, while maintaining the bulk characteristics of PET (such as easy processing, good mechanical properties, reasonably low permeability to oxygen and carbon dioxide gases (barrier properties), and good chemical coupling with antibacterial coatings). Glass-ceramic materials, since their first accidental production in the mid fifties by S.D. Stookey, have been used in a vast area of applications, from household cooktops and stoves, to missile nose cones and mirror mounts of orbital telescopes and from decorative wall coverings to medical applications. The fracture modes, namely transgranular and intergranular modes in glass-ceramic materials have paid less attention in literature comparing with ceramic materials. In the former case the crack paves its way irrespectively of the direction of the grain boundaries, i.e., the interfaces between the different phases. In the latter case the crack preferentially follows them, i.e., debonds the interfaces.

  18. Use of human nail for reconstruction of the orbital floor: an experimental study in rabbits.

    PubMed

    Görgülü, Tahsin; Akçal, Arzu; Uğurlu, Kemal

    2016-07-01

    The orbital floor is the thinnest part of the orbital wall, and in 20% of all maxillofacial injuries it is fractured. Autografts, allografts, and alloplastic materials are used in reconstruction, but there is no consensus about which material is the most appropriate. Nail is a semirigid material that is easy to reshape and is not antigenic. Alloplastic materials, which are used in reconstructions of the orbital floor, have various complications and are expensive. Autografts have donor-site problems, high rates of resorption, and take a long time to do. We created bilateral 10mm defects in the orbital floors in 18 New Zealand rabbits. We reconstructed the left orbital floors with double-ground human nail while the right orbital floors were left open as controls. The orbital floors were examined macroscopically and microscopically at 4, 8, and 12 weeks postoperatively, and there were no macroscopic signs of infection, inflammation, or extrusion. Forced duction tests showed that it was possible to induce movement of the eyeball for all 18 of the reconstructed sides throughout the observation period, and in 14 of the 18 rabbits on the control sides. Positive forced duction test shows us that orbital muscles are trapped in orbital floor defect and due to this movement of eyeball is restricted. Acute and chronic inflammation, fibrosis, vascularisation, and the presence of foreign body giant cells were evaluated microscopically. Acute inflammation and the presence of foreign body giant cells were recorded as mild, whereas fibrosis, chronic inflammation, and vascularisation were severe, as were epithelialisation on the maxillary sinus side of the nails, calcification, and progression of collagen. We found no signs of resorption of the nails. PMID:27090026

  19. [Orbital inflammation].

    PubMed

    Mouriaux, F; Coffin-Pichonnet, S; Robert, P-Y; Abad, S; Martin-Silva, N

    2014-12-01

    Orbital inflammation is a generic term encompassing inflammatory pathologies affecting all structures within the orbit : anterior (involvement up to the posterior aspect of the globe), diffuse (involvement of intra- and/or extraconal fat), apical (involvement of the posterior orbit), myositis (involvement of only the extraocular muscles), dacryoadenitis (involvement of the lacrimal gland). We distinguish between specific inflammation and non-specific inflammation, commonly referred to as idiopathic inflammation. Specific orbital inflammation corresponds to a secondary localization of a "generalized" disease (systemic or auto-immune). Idiopathic orbital inflammation corresponds to uniquely orbital inflammation without generalized disease, and thus an unknown etiology. At the top of the differential diagnosis for specific or idiopathic orbital inflammation are malignant tumors, represented most commonly in the adult by lympho-proliferative syndromes and metastases. Treatment of specific orbital inflammation begins with treatment of the underlying disease. For idiopathic orbital inflammation, treatment (most often corticosteroids) is indicated above all in cases of visual loss due to optic neuropathy, in the presence of pain or oculomotor palsy. PMID:25455557

  20. Altered disc pressure profile after an osteoporotic vertebral fracture is a risk factor for adjacent vertebral body fracture.

    PubMed

    Tzermiadianos, Michael N; Renner, Susan M; Phillips, Frank M; Hadjipavlou, Alexander G; Zindrick, Michael R; Havey, Robert M; Voronov, Michael; Patwardhan, Avinash G

    2008-11-01

    This study investigated the effect of endplate deformity after an osteoporotic vertebral fracture in increasing the risk for adjacent vertebral fractures. Eight human lower thoracic or thoracolumbar specimens, each consisting of five vertebrae were used. To selectively fracture one of the endplates of the middle VB of each specimen a void was created under the target endplate and the specimen was flexed and compressed until failure. The fractured vertebra was subjected to spinal extension under 150 N preload that restored the anterior wall height and vertebral kyphosis, while the fractured endplate remained significantly depressed. The VB was filled with cement to stabilize the fracture, after complete evacuation of its trabecular content to ensure similar cement distribution under both the endplates. Specimens were tested in flexion-extension under 400 N preload while pressure in the discs and strain at the anterior wall of the adjacent vertebrae were recorded. Disc pressure in the intact specimens increased during flexion by 26 +/- 14%. After cementation, disc pressure increased during flexion by 15 +/- 11% in the discs with un-fractured endplates, while decreased by 19 +/- 26.7% in the discs with the fractured endplates. During flexion, the compressive strain at the anterior wall of the vertebra next to the fractured endplate increased by 94 +/- 23% compared to intact status (p < 0.05), while it did not significantly change at the vertebra next to the un-fractured endplate (18.2 +/- 7.1%, p > 0.05). Subsequent flexion with compression to failure resulted in adjacent fracture close to the fractured endplate in six specimens and in a non-adjacent fracture in one specimen, while one specimen had no adjacent fractures. Depression of the fractured endplate alters the pressure profile of the damaged disc resulting in increased compressive loading of the anterior wall of adjacent vertebra that predisposes it to wedge fracture. This data suggests that correction of

  1. Fracture control for the Oman India Pipeline

    SciTech Connect

    Bruno, T.V.

    1996-12-31

    This paper describes the evaluation of the resistance to fracture initiation and propagation for the high-strength, heavy-wall pipe required for the Oman India Pipeline (OIP). It discusses the unique aspects of this pipeline and their influence on fracture control, reviews conventional fracture control design methods, their limitations with regard to the pipe in question, the extent to which they can be utilized for this project, and other approaches being explored. Test pipe of the size and grade required for the OIP show fracture toughness well in excess of the minimum requirements.

  2. Flow upscaling in propped fracture

    NASA Astrophysics Data System (ADS)

    Jasinski, Lukasz; Dabrowski, Marcin

    2016-04-01

    Proppants in combination with hydraulic fracturing are widely used to maintain the production of oil or gas from low permeability formations (i.e. shale rocks). There are also examples of proppants use in geothermal reservoirs. Flow patterns in propped fracture control transport processes and give information about fracture/matrix exchange surface. Our main motivation is to understand flow behavior in such structures using direct numerical simulations and to find a good upscaling technique to be able to investigate models on reservoir scale. We study fracture made of two parallel plane walls, where void space between them is filled with partial monolayer of proppant. As the fracture is affected by closing pressure, the proppant grains are squeezed between two opposite fracture walls which can change the grain shapes or embed the grains into impermeable rock matrix. To take this effect into account and simplify the geometry, the grains are approximated as cylinders. Imposed macroscopic pressure gradient invokes flow in such medium. As the flow is considered in the low Reynolds number regime, a stationary velocity flow field is obtained by solving the Stokes equations in 3D by means of finite element method. Void space between the grains is accurately discretized by using tetrahedral mesh. To reduce computational effort, the Stokes equation is reduced over the fracture aperture to 2D Stokes-Brinkman equation, which is further numerically solved and compared against numerical solution in 3D. Systematic flow calculations using 2D Stokes-Brinkman equation are performed for periodic domain and no slip boundary condition on the grain surface. Results are discussed in terms of effective properties as a function of geometrical parameters of the medium, such as proppant packing fraction and proppant grain diameter to fracture aperture ratio.

  3. Orbiter's Skeleton

    NASA Technical Reports Server (NTRS)

    2005-01-01

    The structure of NASA's Mars Reconnaissance Orbiter spacecraft is constructed from composite panels of carbon layers over aluminum honeycomb, lightweight yet strong. This forms a basic structure or skeleton on which the instruments, electronics, propulsion and power systems can be mounted. The propellant tank is contained in the center of the orbiter's structure. This photo was taken at Lockheed Martin Space Systems, Denver, during construction of the spacecraft.

  4. Fracture Management

    MedlinePlus

    ... to hold the fracture in the correct position. • Fiberglass casting is lighter and stronger and the exterior ... with your physician if this occurs. • When a fiberglass cast is used in conjunction with a GORE- ...

  5. Solute transport at fracture intersections

    NASA Astrophysics Data System (ADS)

    Mourzenko, V. V.; Yousefian, F.; Kolbah, B.; Thovert, J.-F.; Adler, P. M.

    2002-01-01

    A numerical study of three-dimensional solute transportat fracture intersections by using a particle tracking technique is presented.Two models of orthogonal fracture intersection are considered, namely, twoparallel-walled channels and two rough-walled Gaussian fractures. The fluidvelocity is calculated by solving the three-dimensional Stokes equation withno-slip boundary condition at the solid wall. Examples of individual trajectoriesof particles are first given in order to illustrate the main features of thephenomenon. Solute mass partitioning between outgoing fracture branches isconsidered for various transport regimes, characterized by the local Pécletnumber, and for various ratios of the flow rates in the intersecting channels.Generally speaking, it can be said that at dominant diffusion the influenceof the flow rates ratio is weak, while it is important in the opposite situation.Validity of the classical models of solute mixing, stream tube routing, andperfect mixing is analyzed by comparing their predictions with the numericaldata. Preliminary recommendations are made for the use of these results inlarge-scale modeling.

  6. Acetabular fractures: what radiologists should know and how 3D CT can aid classification.

    PubMed

    Scheinfeld, Meir H; Dym, Akiva A; Spektor, Michael; Avery, Laura L; Dym, R Joshua; Amanatullah, Derek F

    2015-01-01

    Correct recognition, description, and classification of acetabular fractures is essential for efficient patient triage and treatment. Acetabular fractures may result from high-energy trauma or low-energy trauma in the elderly. The most widely used acetabular fracture classification system among radiologists and orthopedic surgeons is the system of Judet and Letournel, which includes five elementary (or elemental) and five associated fractures. The elementary fractures are anterior wall, posterior wall, anterior column, posterior column, and transverse. The associated fractures are all combinations or partial combinations of the elementary fractures and include transverse with posterior wall, T-shaped, associated both column, anterior column or wall with posterior hemitransverse, and posterior column with posterior wall. The most unique fracture is the associated both column fracture, which completely dissociates the acetabular articular surface from the sciatic buttress. Accurate categorization of acetabular fractures is challenging because of the complex three-dimensional (3D) anatomy of the pelvis, the rarity of certain acetabular fracture variants, and confusing nomenclature. Comparing a 3D image of the fractured acetabulum with a standard diagram containing the 10 Judet and Letournel categories of acetabular fracture and using a flowchart algorithm are effective ways of arriving at the correct fracture classification. Online supplemental material is available for this article. PMID:25763739

  7. Blowout fracture in a 3-year-old.

    PubMed

    Pluijmers, Britt I; Koudstaal, Maarten J; Paridaens, Dion; van der Wal, Karel G H

    2013-06-01

    A 3-year-old patient was referred to the oral and maxillofacial department with a fracture of the orbital floor. Due to the lack of clinical symptoms, a conservative approach was chosen. After 3 weeks, an enophthalmos developed. The orbital floor reconstruction was successfully performed through a transconjunctival approach. This case highlights the rarity of pure blowout fractures in young children. The specific presentation and diagnostics of orbital floor fractures in children and the related surgical planning and intervention are discussed. PMID:24436749

  8. Blowout Fracture in a 3-Year-Old

    PubMed Central

    Pluijmers, Britt I.; Koudstaal, Maarten J.; Paridaens, Dion; van der Wal, Karel G.H.

    2013-01-01

    A 3-year-old patient was referred to the oral and maxillofacial department with a fracture of the orbital floor. Due to the lack of clinical symptoms, a conservative approach was chosen. After 3 weeks, an enophthalmos developed. The orbital floor reconstruction was successfully performed through a transconjunctival approach. This case highlights the rarity of pure blowout fractures in young children. The specific presentation and diagnostics of orbital floor fractures in children and the related surgical planning and intervention are discussed. PMID:24436749

  9. Application of fracture mechanics on the Space Shuttle

    NASA Technical Reports Server (NTRS)

    Forman, R. G.; Hu, T.

    1984-01-01

    During the design stages of the shuttle orbiter, fracture-mechanics concepts were applied extensively to the highly stressed areas of the structure. This was the first space program to require a comprehensive fracture mechanics approach to prevent structural failures from crack or crack-like defects. As anticipated, some difficult problems were encountered. This paper briefly describes some of them together with the procedure used for fracture control on the orbiter. It is believed that the principles and methods as presented herein can serve as an example of fracture control for aerospace and other industries.

  10. Laboratory Visualization Experiments of Temperature-induced Fractures Around a Borehole (Cryogenic Fracturing) in Shale and Analogue Rock Samples

    NASA Astrophysics Data System (ADS)

    Kneafsey, T. J.; Nakagawa, S.; Wu, Y. S.; Mukhopadhyay, S.

    2014-12-01

    In tight shales, hydraulic fracturing is the dominant method for improving reservoir permeability. However, injecting water-based liquids can induce formation damage and disposal problems, thus other techniques are being sought. One alternative to hydraulic fracturing is producing fractures thermally, using low-temperature fluids (cryogens). The primary consequence of thermal stimulation is that shrinkage fractures are produced around the borehole wall. Recently, cryogenic stimulation produced some promising results when the cryogen (typically liquid nitrogen and cold nitrogen gas) could be brought to reservoir depth. Numerical modeling also showed possible significant increases in gas production from a shale reservoir after cryogenic stimulation. However, geometry and the dynamic behavior of these thermally induced fractures under different stress regimes and rock anisotropy and heterogeneity is not yet well understood.Currently, we are conducting a series of laboratory thermal fracturing experiments on Mancos Shale and transparent glass blocks, by injecting liquid nitrogen under atmospheric pressure into room temperature blocks under various anisotropic stress states. The glass blocks allow clear optical visualization of fracture development and final fracturing patterns. For the shale blocks, X-ray CT is used to image both pre-existing and induced fractures. Also, the effect of borehole orientation with respect to the bedding planes and aligned preexisting fractures is examined. Our initial experiment on a uniaxially compressed glass block showed fracturing behavior which was distinctly different from conventional hydraulic fracturing. In addition to tensile fractures in the maximum principal stress directions, the thermal contraction by the cryogen induced (1) chaotic, spalling fractures around the borehole wall, and (2) a series of disk-shaped annular fractures perpendicular to the borehole. When applied to a horizontal borehole, the propagation plane of the

  11. Wonderful Walls

    ERIC Educational Resources Information Center

    Greenman, Jim

    2006-01-01

    In this article, the author emphasizes the importance of "working" walls in children's programs. Children's programs need "working" walls (and ceilings and floors) which can be put to use for communication, display, storage, and activity space. The furnishings also work, or don't work, for the program in another sense: in aggregate, they serve as…

  12. A Case of Orbital Histoplasmosis.

    PubMed

    Krakauer, Mark; Prendes, Mark Armando; Wilkes, Byron; Lee, Hui Bae Harold; Fraig, Mostafa; Nunery, William R

    2016-01-01

    Histoplasma capsulatum var capsulatum is a dimorphic fungus endemic to the Ohio and Mississippi River Valleys of the United States. In this case report, a 33-year-old woman who presented with a right orbital mass causing progressive vision loss, diplopia, and facial swelling is described. Lateral orbitotomy with lateral orbital wall bone flap was performed for excisional biopsy of the lesion. The 1.5 × 1.8 × 2.3 cm cicatricial mass demonstrated a granulomatous lesion with necrosis and positive staining consistent with Histoplasma capsulatum var capsulatum infection. To the authors' knowledge, this is the first case of orbital histoplasmosis to be reported in the United States and the first case worldwide of orbital histoplasmosis due to Histoplasma capsulatum var capsulatum. PMID:25186215

  13. Pediatric facial fractures: evolving patterns of treatment.

    PubMed

    Posnick, J C; Wells, M; Pron, G E

    1993-08-01

    This study reviews the treatment of facial trauma between October 1986 and December 1990 at a major pediatric referral center. The mechanism of injury, location and pattern of facial fractures, pattern of facial injury, soft tissue injuries, and any associated injuries to other organ systems were recorded, and fracture management and perioperative complications reviewed. The study population consisted of 137 patients who sustained 318 facial fractures. Eighty-one patients (171 fractures) were seen in the acute stage, and 56 patients (147 fractures) were seen for reconstruction of a secondary deformity. Injuries in boys were more prevalent than in girls (63% versus 37%), and the 6- to 12-year cohort made up the largest group (42%). Most fractures resulted from traffic-related accidents (50%), falls (23%), or sports-related injuries (15%). Mandibular (34%) and orbital fractures (23%) predominated; fewer midfacial fractures (7%) were sustained than would be expected in a similar adult population. Three quarters of the patients with acute fractures required operative intervention. Closed reduction techniques with maxillomandibular fixation were frequently chosen for mandibular condyle fractures and open reduction techniques (35%) for other regions of the facial skeleton. When open reduction was indicated, plate-and-screw fixation was the preferred method of stabilization (65%). The long-term effects of the injuries and the treatment given on facial growth remain undetermined. Perioperative complication rates directly related to the surgery were low. PMID:8336220

  14. Orbital cellulitis.

    PubMed Central

    Martin-Hirsch, D P; Habashi, S; Hinton, A H; Kotecha, B

    1992-01-01

    Orbital cellulitis is an emergency. It may cause blindness and progress to life-threatening sequelae such as brain abscess, meningitis and cavernous sinus thrombosis. Successful management is dependent upon urgent referral and immediate treatment. Although isolated eyelid erythema and swelling usually indicate primary infection anterior to the orbital septum, they may also be the first signs of an underlying frontal or ethmoidal sinusitis. The condition always requires emergency referral to both an ophthalmologist and otorhinolaryngologist. Images Fig. 1 Fig. 2 Fig. 3 Fig. 4 PMID:1388488

  15. Orbital Debris

    NASA Technical Reports Server (NTRS)

    Kessler, D. J. (Compiler); Su, S. Y. (Compiler)

    1985-01-01

    Earth orbital debris issues and recommended future activities are discussed. The workshop addressed the areas of environment definition, hazards to spacecraft, and space object management. It concluded that orbital debris is a potential problem for future space operations. However, before recommending any major efforts to control the environment, more data are required. The most significant required data are on the population of debris smaller than 4 cm in diameter. New damage criteria are also required. When these data are obtained, they can be combined with hypervelocity data to evaluate the hazards to future spacecraft. After these hazards are understood, then techniques to control the environment can be evaluated.

  16. Fluid Flow Within Fractured Porous Media

    SciTech Connect

    Crandall, D.M.; Ahmadi, G.; Smith, D.H.; Bromhal, G.S.

    2006-10-01

    Fractures provide preferential flow paths to subterranean fluid flows. In reservoir scale modeling of geologic flows fractures must be approximated by fairly simple formulations. Often this is accomplished by assuming fractures are parallel plates subjected to an applied pressure gradient. This is known as the cubic law. An induced fracture in Berea sandstone has been digitized to perform numerical flow simulations. A commercially available computational fluid dynamics software package has been used to solve the flow through this model. Single phase flows have been compared to experimental works in the literature to evaluate the accuracy with which this model can be applied. Common methods of fracture geometry classification are also calculated and compared to experimentally obtained values. Flow through regions of the fracture where the upper and lower fracture walls meet (zero aperture) are shown to induce a strong channeling effect on the flow. This model is expanded to include a domain of surrounding porous media through which the flow can travel. The inclusion of a realistic permeability in this media shows that the regions of small and zero apertures contribute to the greatest pressure losses over the fracture length and flow through the porous media is most prevalent in these regions. The flow through the fracture is shown to be the largest contributor to the net flow through the media. From this work, a novel flow relationship is proposed for flow through fractured media.

  17. Gullies in Crater Wall

    NASA Technical Reports Server (NTRS)

    2004-01-01

    6 April 2004 This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows gullies in the wall of a large impact crater in Newton Basin near 41.9oS, 158.1oW. Such gullies may have formed by downslope movement of wet debris--i.e., water. Unfortunately, because the responsible fluid (if there was one) is no longer present today, only the geomorphology of the channels and debris aprons can be used to deduce that water might have been involved. The image covers an area about 3 km (1.9 mi) across. Sunlight illuminates the scene from the upper left.

  18. Pediatric Thighbone (Femur) Fracture

    MedlinePlus

    ... fractures in infants under 1 year old is child abuse. Child abuse is also a leading cause of thighbone fracture ... contact sports • Being in a motor vehicle accident • Child abuse Types of Femur Fractures (Classification) Femur fractures vary ...

  19. Hydraulic fracturing-1

    SciTech Connect

    Not Available

    1990-01-01

    This book contains papers on hydraulic fracturing. Topics covered include: An overview of recent advances in hydraulic fracturing technology; Containment of massive hydraulic fracture; and Fracturing with a high-strength proppant.

  20. Vibrational modes of hydraulic fractures: Inference of fracture geometry from resonant frequencies and attenuation

    NASA Astrophysics Data System (ADS)

    Lipovsky, Bradley P.; Dunham, Eric M.

    2015-02-01

    Oscillatory seismic signals arising from resonant vibrations of hydraulic fractures are observed in many geologic systems, including volcanoes, glaciers and ice sheets, and hydrocarbon and geothermal reservoirs. To better quantify the physical dimensions of fluid-filled cracks and properties of the fluids within them, we study wave motion along a thin hydraulic fracture waveguide. We present a linearized analysis, valid at wavelengths greater than the fracture aperture, that accounts for quasi-static elastic deformation of the fracture walls, as well as fluid viscosity, inertia, and compressibility. In the long-wavelength limit, anomalously dispersed guided waves known as crack or Krauklis waves propagate with restoring force from fracture wall elasticity. At shorter wavelengths, the waves become sound waves within the fluid channel. Wave attenuation in our model is due to fluid viscosity, rather than seismic radiation from crack tips or fracture wall roughness. We characterize viscous damping at both low frequencies, where the flow is always fully developed, and at high frequencies, where the flow has a nearly constant velocity profile away from viscous boundary layers near the fracture walls. Most observable seismic signals from resonating fractures likely arise in the boundary layer crack wave limit, where fluid-solid coupling is pronounced and attenuation is minimal. We present a method to estimate the aperture and length of a resonating hydraulic fracture using both the seismically observed quality factor and characteristic frequency. Finally, we develop scaling relations between seismic moment and characteristic frequency that might be useful when interpreting the statistics of hydraulic fracture events.

  1. Wall Turbulence.

    ERIC Educational Resources Information Center

    Hanratty, Thomas J.

    1980-01-01

    This paper gives an account of research on the structure of turbulence close to a solid boundary. Included is a method to study the flow close to the wall of a pipe without interferring with it. (Author/JN)

  2. The fracture flow equation and its perturbation solution

    NASA Astrophysics Data System (ADS)

    Basha, H. A.; El-Asmar, W.

    2003-12-01

    This work derives the fracture flow equation from the two-dimensional steady form of the Navier-Stokes equation. Asymptotic solutions are obtained whereby the perturbation parameter is the ratio of the mean width over the length of the fracture segment. The perturbation expansion can handle arbitrary variation of the fracture walls as long as the dominant velocity is in the longitudinal direction. The effect of the matrix-fracture interaction is also taken into account by allowing leakage through the fracture walls. The perturbation solution is used to obtain an estimate of the flow rate and the fracture transmissivity as well as the velocity and the pressure distribution in fractures of various geometries. The analysis covers eight different configurations of fracture geometry including linear and curvilinear variation as well as sinusoidal variation in the top and bottom walls with varying horizontal alignment and roughness wavelengths. The zero-order solution yields the Reynolds lubrication approximation, and the higher-order equations provide a correction term to the flow rate in terms of the roughness frequency and the Reynolds number. For sinusoidal and linear walls, the mathematical analysis shows that the zero-order flow rate could be expressed in terms of the maximum to minimum width ratio. For equal widths at both ends of the fracture, the first-order correction is zero. For sinusoidal fractures, the flow rate decreases with increasing Reynolds number and with increasing roughness amplitude and frequency. The effect of leakage is to create a nonuniform flow distribution in the fracture that deviates significantly from the flow rate estimate for impermeable walls. The derived flow expressions can provide a more reliable tool for flow and transport predictions in fractured domain.

  3. General view of he forward wall of the mid deck ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    General view of he forward wall of the mid deck of the Orbiter Discovery. In this view a majority of wall panels have been removed to reveal the avionics bays in the interstitial space between the mid deck forward wall and the forward bulkhead of the pressurized crew compartment. This photograph was taken at Kennedy Space Center. - Space Transportation System, Orbiter Discovery (OV-103), Lyndon B. Johnson Space Center, 2101 NASA Parkway, Houston, Harris County, TX

  4. A Novel Method of Orbital Floor Reconstruction Using Virtual Planning, 3-Dimensional Printing, and Autologous Bone.

    PubMed

    Vehmeijer, Maarten; van Eijnatten, Maureen; Liberton, Niels; Wolff, Jan

    2016-08-01

    Fractures of the orbital floor are often a result of traffic accidents or interpersonal violence. To date, numerous materials and methods have been used to reconstruct the orbital floor. However, simple and cost-effective 3-dimensional (3D) printing technologies for the treatment of orbital floor fractures are still sought. This study describes a simple, precise, cost-effective method of treating orbital fractures using 3D printing technologies in combination with autologous bone. Enophthalmos and diplopia developed in a 64-year-old female patient with an orbital floor fracture. A virtual 3D model of the fracture site was generated from computed tomography images of the patient. The fracture was virtually closed using spline interpolation. Furthermore, a virtual individualized mold of the defect site was created, which was manufactured using an inkjet printer. The tangible mold was subsequently used during surgery to sculpture an individualized autologous orbital floor implant. Virtual reconstruction of the orbital floor and the resulting mold enhanced the overall accuracy and efficiency of the surgical procedure. The sculptured autologous orbital floor implant showed an excellent fit in vivo. The combination of virtual planning and 3D printing offers an accurate and cost-effective treatment method for orbital floor fractures. PMID:27137437

  5. Comparative Study of Naugle and Hertel Exophthalmometry in Orbitozygomatic Fracture.

    PubMed

    Jeon, Hong Bae; Kang, Dong Hee; Oh, Sang Ah; Gu, Ja Hea

    2016-01-01

    Accurate perioperative evaluation of enophthalmos is important to determine the adequacy of surgical repair in orbitozygomatic fracture. In this study, the authors evaluated the degree of enophthalmos using Hertel and Naugle exophthalmometry in patients with pure blowout fracture and orbitozygomatic fracture, and compared the results. Fifty patients were divided into 2 groups: pure blowout fracture (Group A: control group, 25 patients) and orbitozygomatic fracture with displaced lateral orbital rim (Group B: experimental group, 25 patients). Hertel and Naugle scales were measured before and 6 months after surgery. The degree of lateral orbital rim advancement was assessed by comparing the difference between the perioperative change of the Hertel and Naugle scales. In Group A, the difference between the pre- and postoperative scales in the 2 exophthalmometry was statistically significant (P < 0.05). In Group B, the Hertel scale increased from -0.20 to -0.16 mm, with an insignificant difference between pre- and postoperative values (P > 0.05) and the Naugle scale increased from -0.88 to -0.20 mm, with a significant difference (P < 0.05). The Δ Hertel scale differed from the Δ Naugle scale by a mean of -0.64 mm, which represents the degree of lateral orbital rim advancement. Naugle exophthalmometry is a more reliable method for evaluation of enophthalmos in lateral orbital rim displaced orbitozygomatic fractures than Hertel exophthalmometry. The degree of lateral orbital rim advancement can be assessed by combined use of the Hertel and Naugle exophthalmometry in orbitozygomatic fractures. PMID:26674913

  6. Wall Shear Stress, Wall Pressure and Near Wall Velocity Field Relationships in a Whirling Annular Seal

    NASA Technical Reports Server (NTRS)

    Morrison, Gerald L.; Winslow, Robert B.; Thames, H. Davis, III

    1996-01-01

    The mean and phase averaged pressure and wall shear stress distributions were measured on the stator wall of a 50% eccentric annular seal which was whirling in a circular orbit at the same speed as the shaft rotation. The shear stresses were measured using flush mounted hot-film probes. Four different operating conditions were considered consisting of Reynolds numbers of 12,000 and 24,000 and Taylor numbers of 3,300 and 6,600. At each of the operating conditions the axial distribution (from Z/L = -0.2 to 1.2) of the mean pressure, shear stress magnitude, and shear stress direction on the stator wall were measured. Also measured were the phase averaged pressure and shear stress. These data were combined to calculate the force distributions along the seal length. Integration of the force distributions result in the net forces and moments generated by the pressure and shear stresses. The flow field inside the seal operating at a Reynolds number of 24,000 and a Taylor number of 6,600 has been measured using a 3-D laser Doppler anemometer system. Phase averaged wall pressure and wall shear stress are presented along with phase averaged mean velocity and turbulence kinetic energy distributions located 0.16c from the stator wall where c is the seal clearance. The relationships between the velocity, turbulence, wall pressure and wall shear stress are very complex and do not follow simple bulk flow predictions.

  7. Patterns of fracture and tidal stresses on Europa

    NASA Technical Reports Server (NTRS)

    Helfenstein, P.; Parmentier, E. M.

    1983-01-01

    A comparison of dark band, triple band, and cuspate ridge orientations with the fracture patterns predicted for tidal distortion due to orbital recession and eccentricity is undertaken, to test the hypothesized identification of Europa's lineaments as tidal distortion and planetary volume change fractures. Short, reticule dark bands near the anti-Jove point could be tension cracks caused by orbital eccentricity. Long, arcuate dark bands and triple bands peripheral to the anti-Jove point may be strike-slip faults due to orbital recession. The orientation and distribution of cuspate ridges, if they are compressional, suggests their formation in response to a combination of orbital recession and planetary volume decrease. If surface fracturing is due to tidal deformation, important constraints are exerted by it on Europa's orbital evolution.

  8. Eye and orbit ultrasound

    MedlinePlus

    Echography - eye orbit; Ultrasound - eye orbit; Ocular ultrasonography; Orbital ultrasonography ... ophthalmology department of a hospital or clinic. Your eye is numbed with medicine (anesthetic drops). The ultrasound ...

  9. Fracturing operations in a dry geothermal reservoir

    SciTech Connect

    Rowley, J.C.; Pettitt, R.A.; Hendron, R.H.; Sinclair, A.R.; Nicholson, R.W.

    1983-01-01

    Fracturing and completing deep wells in hot, nonporous crystalline basement rock challenges conventional equipment use, procedures, and techniques common in oil and gas and normal geothermal completions. Fracturing operations at the Fenton Hill, New Mexico, Hot Dry Rock (HDR) Geothermal Test Site initiated unique developments necessary to solve problems caused by an extremely harsh down-hole environment. Hydraulic fracturing experiments to connect the 2 wells have used openhole packers, hydraulic jet notching of the borehole wall, cemented-in isolation liners, and casing packers. Problems were encountered with hole drag, high fracture gradients, H/sub 2/S in vent back fluids, stress corrosion cracking of tubulars, and the complex nature of 3-dimensional fracture growth that requires large volumes of injected water. 20 references.

  10. The Orbital Workshop Sleep Compartment

    NASA Technical Reports Server (NTRS)

    1972-01-01

    This wide-angle view is of the Orbital Workshop (OWS) sleep compartment, located in the lower level of the OWS. Each crewman was assigned a small space for sleeping and zipped themselves into sleeping bags stretched against the wall. Because of the absence of gravity, sleeping comfort was achieved in any position relative to the spacecraft; body support was not necessary. Sleeping could be accommodated quite comfortably in a bag that held the body at a given place in Skylab.

  11. 'Stucco' Walls

    NASA Technical Reports Server (NTRS)

    2004-01-01

    This projected mosaic image, taken by the microscopic imager, an instrument located on the Mars Exploration Rover Opportunity 's instrument deployment device, or 'arm,' shows the partial clotting or cement-like properties of the sand-sized grains within the trench wall. The area in this image measures approximately 3 centimeters (1.2 inches) wide and 5 centimeters (2 inches) tall.(This image also appears as an inset on a separate image from the rover's navigation camera, showing the location of this particular spot within the trench wall.)

  12. Bilateral orbital bone infarction in sickle-cell disease.

    PubMed

    Ghafouri, Roya H; Lee, Irene; Freitag, Suzanne K; Pira, Tony N

    2011-01-01

    This is a case of a 2-year-old boy with sickle cell disease who presented with bilateral eyelid swelling, limited extraocular motility, and lateral subperiosteal fluid collection associated with bilateral lateral orbital wall infarctions on MRI. The patient was managed medically with intravenous fluids, analgesics, broad-spectrum antibiotics, systemic steroids, and clinically improved. Patients with sickle cell disease are susceptible to infarction of the orbital bones during vaso-occlusive crises. Orbital wall infarction can lead to acute proptosis and restricted extraocular motility. Orbital wall infarction should be considered in sickle cell patients with orbital diseases so that appropriate treatment can be instituted promptly to prevent the serious sequelae of orbital compression syndrome. PMID:20577135

  13. EFFECTS OF LITHOLOGY ON TELEVIEWER-LOG QUALITY AND FRACTURE INTERPRETATION.

    USGS Publications Warehouse

    Paillet, Frederick L.; Keys, W.S.; Hess, A.E.

    1985-01-01

    Representative televiewer logs illustrating natural fractures in such common rock types as granite, gabbro, basalt, schist, sandstone, limestone and shale are presented in addition to photographs of the same fractures in core samples. These examples demonstrate the many difficulties in recognizing fractures on televiewer logs compared to fractures in logs because of the vertical scale distortion on televiewer logs and from drilling damage to the fractures at the borehole wall. All of these results demonstrate that significant fracture widening usually occurs during drilling, explaining why fractures described by the core logger as closed can be consistently detected on televiewer logs.

  14. Controversies in orbital reconstruction--II. Timing of post-traumatic orbital reconstruction: a systematic review.

    PubMed

    Dubois, L; Steenen, S A; Gooris, P J J; Mourits, M P; Becking, A G

    2015-04-01

    The timing of orbital reconstruction is a determinative factor with respect to the incidence of potential postoperative orbital complications. In orbital trauma surgery, a general distinction is made between immediate (within hours), early (within 2 weeks), and late surgical intervention. There is a strong consensus on the indications for immediate repair, but clinicians face challenges in identifying patients with minimal defects who may actually benefit from delayed surgical treatment. Moreover, controversies exist regarding the risk of late surgery-related orbital fibrosis, since traumatic ocular motility disorders sometimes recover spontaneously and therefore do not necessarily require surgery. In this study, all currently available evidence on timing as an independent variable in orbital fracture reduction outcomes for paediatric and adult patients was systematically reviewed. Current evidence supports guidelines for immediate repair but is insufficient to support guidelines on the best timing for non-immediate orbital reconstruction. PMID:25543904

  15. Orbit analysis

    SciTech Connect

    Michelotti, L.

    1995-01-01

    The past fifteen years have witnessed a remarkable development of methods for analyzing single particle orbit dynamics in accelerators. Unlike their more classic counterparts, which act upon differential equations, these methods proceed by manipulating Poincare maps directly. This attribute makes them well matched for studying accelerators whose physics is most naturally modelled in terms of maps, an observation that has been championed most vigorously by Forest. In the following sections the author sketchs a little background, explains some of the physics underlying these techniques, and discusses the best computing strategy for implementing them in conjunction with modeling accelerators.

  16. CONTAMINANT TRANSPORT IN PARALLEL FRACTURED MEDIA: SUDICKY AND FRIND REVISITED

    EPA Science Inventory

    This paper is concerned with a modified, nondimensional form of the parallel fracture, contaminant transport model of Sudicky and Frind (1982). The modifications include the boundary condition at the fracture wall, expressed by a parameter, and the power-law relationship between...

  17. CONTAMINANT TRANSPORT IN PARALLEL FRACTURED MEDIA: SUDICKY AND FRIND REVISITED

    EPA Science Inventory

    This paper is concerned with a modified, nondimensional form of the parallel fracture, contaminant transport model of Sudicky and Frind (1982). The modifications include the boundary condition at the fracture wall, expressed by a parameter , and the power-law relationship betwe...

  18. Wall Covering

    NASA Technical Reports Server (NTRS)

    1978-01-01

    The attractive wall covering shown below is one of 132 styles in the Mirror Magic II line offered by The General Tire & Rubber Company, Akron, Ohio. The material is metallized plastic fabric, a spinoff from space programs. Wall coverings are one of many consumer applications of aluminized plastic film technology developed for NASA by a firm later bought by King-Seeley Thermos Company, Winchester, Massachusetts, which now produces the material. The original NASA use was in the Echo 1 passive communications satellite, a "space baloon" made of aluminized mylar; the high reflectivity of the metallized coating enabled relay of communications signals from one Earth station to another by "bouncing" them off the satellite. The reflectivity feature also made the material an extremely efficient insulator and it was subsequently widely used in the Apollo program for such purposes as temperature control of spacecraft components and insulation of tanks for fuels that must be maintained at very low temperatures. I Used as a wall covering, the aluminized material offers extra insulation, reflects light and I resists cracking. In addition to General Tire, King-Seeley also supplies wall covering material to Columbus Coated Fabrics Division of Borden, Incorporated, Columbus, Ohio, among others.

  19. Wall Art

    ERIC Educational Resources Information Center

    McGinley, Connie Q.

    2004-01-01

    The author of this article, an art teacher at Monarch High School in Louisville, Colorado, describes how her experience teaching in a new school presented an exciting visual challenge for an art teacher--monotonous brick walls just waiting for decoration. This school experienced only minimal instances of graffiti, but as an art teacher, she did…

  20. 'White-eyed' blowout fracture: a case series of five children.

    PubMed

    Foulds, J S; Laverick, S; MacEwen, C J

    2013-06-01

    The 'white-eyed' blowout fracture is an orbital injury in children that is commonly initially misdiagnosed as a head injury because of predominant autonomic features and lack of soft-tissue signs. We present five patients who presented with nausea and vomiting following an apparent mild head or facial injury. None of the five had any external evidence of injury. Despite each case describing diplopia, there was a delayed diagnosis of at least 24 h. CT examination demonstrated an inferior orbital wall fracture in all cases with entrapment of the inferior rectus muscle. Each patient underwent surgical repair, two within 48 h of their injury, both of whom achieved complete recovery of ocular movements, while three were delayed beyond 48 h, with a resulting residual limitation of upgaze in all. It is, therefore, important for clinicians to be aware of this condition, so that it can be diagnosed early in order for early surgical release to be performed, which is associated with an excellent prognosis. PMID:23592727

  1. Inter-wall bridging induced peeling of multi-walled carbon nanotubes during tensile failure in aluminum matrix composites.

    PubMed

    Chen, Biao; Li, Shufeng; Imai, Hisashi; Umeda, Junko; Takahashi, Makoto; Kondoh, Katsuyoshi

    2015-02-01

    In situ scanning electron microscopy (SEM) observation of a tensile test was performed to investigate the fracturing behavior of multi-walled carbon nanotubes (MWCNTs) in powder metallurgy Al matrix composites. A multiple peeling phenomenon during MWCNT fracturing was clearly observed. Its formation mechanism and resultant effect on the composite strength were examined. Through transition electron microscopy characterizations, it was observed that defective structures like inter-wall bridges cross-linked adjacent walls of MWCNTs. This structure was helpful to improve the inter-wall bonding conditions, leading to the effective load transfer between walls and resultant peeling behaviors of MWCNTs. These results might provide new understandings of the fracturing mechanisms of carbon nanotube reinforcements for designing high-performance nanocomposites. PMID:25437849

  2. Hydraulic conductivity of rock fractures

    SciTech Connect

    Zimmerman, R.W.; Bodvarsson, G.S.

    1994-10-01

    Yucca Mountain, Nevada contains numerous geological units that are highly fractured. A clear understanding of the hydraulic conductivity of fractures has been identified as an important scientific problem that must be addressed during the site characterization process. The problem of the flow of a single-phase fluid through a rough-walled rock fracture is discussed within the context of rigorous fluid mechanics. The derivation of the cubic law is given as the solution to the Navier-Stokes equations for flow between smooth, parallel plates, the only fracture geometry that is amenable to exact treatment. The various geometric and kinetic conditions that are necessary in order for the Navier-Stokes equations to be replaced by the more tractable lubrication or Hele-Shaw equations are studied and quantified. Various analytical and numerical results are reviewed pertaining to the problem of relating the effective hydraulic aperture to the statistics of the aperture distribution. These studies all lead to the conclusion that the effective hydraulic aperture is always less than the mean aperture, by a factor that depends on the ratio of the mean value of the aperture to its standard deviation. The tortuosity effect caused by regions where the rock walls are in contact with each other is studied using the Hele-Shaw equations, leading to a simple correction factor that depends on the area fraction occupied by the contact regions. Finally, the predicted hydraulic apertures are compared to measured values for eight data sets from the literature for which aperture and conductivity data were available on the same fracture. It is found that reasonably accurate predictions of hydraulic conductivity can be made based solely on the first two moments of the aperture distribution function, and the proportion of contact area. 68 refs.

  3. Endoscopic removal of bullet from orbital apex.

    PubMed

    Muhammad Khyani, Iqbal A; Hafeez, Atif; Farooq, Muhammad Umer; Alam, Jawaid

    2008-10-01

    Penetrating injuries of face are not uncommon. Bullets or pallets may be lodged anywhere in the cavities of skull as a result of firearm injury. Lodgment of a bullet within the orbit through nose is uncommon. An eighteen 18 years old married woman sustained a bullet injury, which entered through lateral wall of the nose and lodged at left orbital apex area. The bullet was removed endoscopically via left nostril without any damage to the eye or disturbance in vision. PMID:18940126

  4. Posttraumatic Intracranial Tuberculous Subdural Empyema in a Patient with Skull Fracture

    PubMed Central

    Kim, Jiha; Kim, Choonghyo; Ryu, Young-Joon

    2016-01-01

    Intracranial tuberculous subdural empyema (ITSE) is extremely rare. To our knowledge, only four cases of microbiologically confirmed ITSE have been reported in the English literature to date. Most cases have arisen in patients with pulmonary tuberculosis regardless of trauma. A 46-year-old man presented to the emergency department after a fall. On arrival, he complained of pain in his head, face, chest and left arm. He was alert and oriented. An initial neurological examination was normal. Radiologic evaluation revealed multiple fractures of his skull, ribs, left scapula and radius. Though he had suffered extensive skull fractures of his cranium, maxilla, zygoma and orbital wall, the sustained cerebral contusion and hemorrhage were mild. Eighteen days later, he suddenly experienced a general tonic-clonic seizure. Radiologic evaluation revealed a subdural empyema in the left occipital area that was not present on admission. We performed a craniotomy, and the empyema was completely removed. Microbiological examination identified Mycobacterium tuberculosis (M. tuberculosis). After eighteen months of anti-tuberculous treatment, the empyema disappeared completely. This case demonstrates that tuberculosis can induce empyema in patients with skull fractures. Thus, we recommend that M. tuberculosis should be considered as the probable pathogen in cases with posttraumatic empyema. PMID:27226867

  5. Posttraumatic Intracranial Tuberculous Subdural Empyema in a Patient with Skull Fracture.

    PubMed

    Kim, Jiha; Kim, Choonghyo; Ryu, Young-Joon; Lee, Seung Jin

    2016-05-01

    Intracranial tuberculous subdural empyema (ITSE) is extremely rare. To our knowledge, only four cases of microbiologically confirmed ITSE have been reported in the English literature to date. Most cases have arisen in patients with pulmonary tuberculosis regardless of trauma. A 46-year-old man presented to the emergency department after a fall. On arrival, he complained of pain in his head, face, chest and left arm. He was alert and oriented. An initial neurological examination was normal. Radiologic evaluation revealed multiple fractures of his skull, ribs, left scapula and radius. Though he had suffered extensive skull fractures of his cranium, maxilla, zygoma and orbital wall, the sustained cerebral contusion and hemorrhage were mild. Eighteen days later, he suddenly experienced a general tonic-clonic seizure. Radiologic evaluation revealed a subdural empyema in the left occipital area that was not present on admission. We performed a craniotomy, and the empyema was completely removed. Microbiological examination identified Mycobacterium tuberculosis (M. tuberculosis). After eighteen months of anti-tuberculous treatment, the empyema disappeared completely. This case demonstrates that tuberculosis can induce empyema in patients with skull fractures. Thus, we recommend that M. tuberculosis should be considered as the probable pathogen in cases with posttraumatic empyema. PMID:27226867

  6. Orbital Winch

    NASA Technical Reports Server (NTRS)

    Hoyt, Robert (Inventor); Slostad, Jeffrey T. (Inventor); Frank, Scott (Inventor); Barnes, Ian M. (Inventor)

    2016-01-01

    Orbital winch having: lower and upper frames; spool having upper and lower flanges with lower flange attached to lower frame; axial tether guide mounted to upper frame; secondary slewing ring coaxial with spool and rotatably mounted to upper frame, wherein secondary slewing ring's outer surface has gearing; upper tether guide mounted to inner surface of secondary slewing ring; linear translation means having upper end mounted to upper frame and lower end mounted on lower frame; primary slewing ring rotatably mounted within linear translation means allowing translation axially between flanges, wherein primary slewing ring's outer surface has gearing; lower tether guide mounted on primary slewing ring's inner surface; pinion rod having upper end mounted to upper frame and lower end mounted to lower frame, wherein pinion rod's teeth engage primary and secondary slewing rings' outer surface teeth; and tether passing through axial, upper, and lower tether guides and winding around spool.

  7. Investigation of blast-induced fracture in rock mass using reversed vertical seismic profiling

    NASA Astrophysics Data System (ADS)

    Zou, D. H.; Wu, Y. K.

    2001-10-01

    The rock mass on quarry and pit wall surfaces is usually fractured during production blasting. Quantitative investigations of the fractured zones are needed for stabilization of the rock walls. In this study, the principle of reversed vertical seismic profiling (RVSP) was applied. A set of seismic geophones were arranged on the horizontal bench surface and seismic signals were generated along the vertical rock wall using a free-swinging hammer. The travel times of seismic rays were recorded and the P-wave velocities of the rock mass were analyzed using the Simultaneous Iterative Reconstruction Technique (SIRT). A series of site tests have been carried out on the rock walls at a granite quarry that are characterized by fractures. The fracture depth at various locations on the wall surface is thereby determined. The results indicate that RVSP provides an easy and reliable method to quantitatively evaluate the blasting-induced fractures in the rock mass.

  8. Radial head fracture - aftercare

    MedlinePlus

    Elbow fracture - radial head - aftercare ... the radius bone, just below your elbow. A fracture is a break in your bone. The most common cause of a radial head fracture is falling with an outstretched arm.

  9. Hand fracture - aftercare

    MedlinePlus

    ... this page: //medlineplus.gov/ency/patientinstructions/000552.htm Hand fracture - aftercare To use the sharing features on ... need to be repaired with surgery. Types of hand fractures Your fracture may be in one of ...

  10. Orbital Compartment Syndrome Leading to Visual Loss following Orbital Floor Reconstruction.

    PubMed

    Susarla, Srinivas M; Nam, Arthur J; Dorafshar, Amir H

    2016-06-01

    Reconstruction of posttraumatic orbital defects carries the attendant risk of injury to the ocular adnexa, globe, and associated neurovascular structures. Blindness following repair of orbital fractures is an infrequent but well-documented phenomenon. Visual acuity loss can be related to direct intraoperative injury to the optic nerve, retinal arterial occlusion, or delayed presentation of acute optic nerve injury. In this report, we document a unique case of acute optic nerve infarction occurring 14 hours following orbital floor exploration and repair in a 56-year-old man. PMID:27162573

  11. Temporal posttraumatic limited ocular movement with suspected trapdoor fracture.

    PubMed

    Song, Young-Seok; Yokota, Harumasa; Ito, Haruna; Yoshida, Akitoshi

    2014-01-01

    Trapdoor fractures, or blowout fractures, result from muscle entrapment after orbital floor fractures. The incarcerated muscles may become necrotic because of ischemia; immediate surgery is recommended for symptomatic persistent diplopia or clinical evidence of entrapment. We report a case of spontaneous resolution of diplopia in a patient with a high suspicion of a trapdoor fracture. A 15-year-old girl presented with diplopia after being hit in the eye while playing volleyball. Computed tomography did not show a fractured orbital bone, but the forced duction test was positive when the left eye was pulled forward toward the left. Magnetic resonance imaging was negative for edema and inflammation in the extraocular muscles. With observation only, the diplopia resolved 2 weeks after onset. A negative forced duction test confirmed the resolution. Observation only may be appropriate in cases with posttraumatic limited ocular movement, after imaging has excluded an emergent condition. PMID:25170246

  12. Temporal posttraumatic limited ocular movement with suspected trapdoor fracture

    PubMed Central

    Song, Young-Seok; Yokota, Harumasa; Ito, Haruna; Yoshida, Akitoshi

    2014-01-01

    Trapdoor fractures, or blowout fractures, result from muscle entrapment after orbital floor fractures. The incarcerated muscles may become necrotic because of ischemia; immediate surgery is recommended for symptomatic persistent diplopia or clinical evidence of entrapment. We report a case of spontaneous resolution of diplopia in a patient with a high suspicion of a trapdoor fracture. A 15-year-old girl presented with diplopia after being hit in the eye while playing volleyball. Computed tomography did not show a fractured orbital bone, but the forced duction test was positive when the left eye was pulled forward toward the left. Magnetic resonance imaging was negative for edema and inflammation in the extraocular muscles. With observation only, the diplopia resolved 2 weeks after onset. A negative forced duction test confirmed the resolution. Observation only may be appropriate in cases with posttraumatic limited ocular movement, after imaging has excluded an emergent condition. PMID:25170246

  13. ‘Sutureless’ transconjunctival approach for infraorbital rim fractures

    PubMed Central

    Nagaraj, Vaibhav; Ghosh, Abhishek; Nanjappa, Madan; Ramesh, Keerthi

    2015-01-01

    Aim: To analyze the ease and surgical outcome of using sutureless transconjunctival approach for repair of infra-orbital fractures. Design: Prospective clinical case series. Materials and Methods: Totally 5 patients with infra-orbital rim or orbital floor fractures were selected and the fractures were accessed through a pre-septal transconjunctival incision. After reduction and fixation, the conjunctiva was just re-approximated and re-draped into position. Incidence of post-operative complications such as diplopia, lid retraction, eyelid dystopia, foreign body granuloma and poor conjunctival healing was assessed at intervals of 1 week, 15 days and a month post-operatively. Results: No complications were observed in any of the 5 patients. Healing was satisfactory in all patients. Conclusion: The sutureless technique appears to be a time saving and technically simpler viable alternative to multilayered suturing in orbital trauma with minimal post-operative complications. PMID:25821377

  14. Models of fracture lineaments - Joint swarms, fracture corridors and faults in crystalline rocks, and their genetic relations

    NASA Astrophysics Data System (ADS)

    Gabrielsen, Roy H.; Braathen, Alvar

    2014-07-01

    Fracture lineaments in crystalline and metamorphic rocks of southern Norway can be subdivided into joint swarms, fracture corridors and faults, depending on displacement, the fracture mode and patterns, and the presence of fault rocks. Their physical appearance as lineaments seen by remote sensing is not discernible, as they define km-long and narrow tabular zones of high fracture intensity. Intrinsically, fracture zonation becomes better expressed from joint swarms to fracture corridors and especially faults as a consequence of increasing accumulate strain. Joint swarms and fracture corridors commonly reveal a symmetric fracture zonation on both sides of its core, whereas inclined extensional faults tend to have asymmetric patterns with enhanced strain and a wider damage zone in the hanging wall. Fracture lineament can be mapped in subzones A-B (core), which are typically some cm up to some tens of meters wide. Common structural elements are fault rocks/shear zones, lenses, and a network of fractures often with very high fracture frequency. Secondary minerals are common. Outside this, subzones C-D (damage zone) are commonly 20-50-m\\ wide with lower fracture intensity of lineament-parallel fracturing, defining the topographic boundary of the lineament. Mineralisation is rarer. The transitional subzone E of multi-orientation fractures defines the transition to the background fracture system. We propose a model for the classification and development of fracture lineaments, applying their architecture (intrinsic geometry, spatial fracture pattern and spatial distribution of fault rocks) as tools for the systematic description. This links fault growth processes and mechanisms that can be ascribed to strain hardening and softening scenarios in a model of fault architecture.

  15. NASGRO(registered trademark): Fracture Mechanics and Fatigue Crack Growth Analysis Software

    NASA Technical Reports Server (NTRS)

    Forman, Royce; Shivakumar, V.; Mettu, Sambi; Beek, Joachim; Williams, Leonard; Yeh, Feng; McClung, Craig; Cardinal, Joe

    2004-01-01

    This viewgraph presentation describes NASGRO, which is a fracture mechanics and fatigue crack growth analysis software package that is used to reduce risk of fracture in Space Shuttles. The contents include: 1) Consequences of Fracture; 2) NASA Fracture Control Requirements; 3) NASGRO Reduces Risk; 4) NASGRO Use Inside NASA; 5) NASGRO Components: Crack Growth Module; 6) NASGRO Components:Material Property Module; 7) Typical NASGRO analysis: Crack growth or component life calculation; and 8) NASGRO Sample Application: Orbiter feedline flowliner crack analysis.

  16. Fluid and particulate suspension flows at fracture junctions

    NASA Astrophysics Data System (ADS)

    Lo, Tak S.; Koplik, Joel

    2015-03-01

    Suspended particles can be a serious problem in geological contexts such as fluid recovery from reservoirs because they alter the rheology of the flowing liquids and may obstruct transport by narrowing flow channels due to deposition or gravitational sedimentation. In particular, the irregular geometry of the fracture walls can trap particles, induce jamming and cause unwanted channeling effects. We have investigated particle suspension flows in tight geological fractures using lattice Boltzmann method in the past. In this work we extend these studies to flows at a junction where two fractures intersect, an essential step towards a complete understanding of flows in fracture networks. The fracture walls are modeled as realistic self-affine fractal surfaces, and we focus on the case of tight fractures, where the wall roughness, the aperture and the particle size are all comparable. The simulations provide complete detail on the particle configurations and the fluid flow field, from which the stresses in the fluid and the forces acting on the bounding walls can be computed. With these information, phenomena such as particle mixing and dispersion, mechanical responses of the solid walls, possible jamming and release at junctions, and other situations of interest can be investigated. Work supported by NERSC and DOE.

  17. Resolution of diplopia after repair of the deep orbit.

    PubMed

    Sleep, T J; Evans, B T; Webb, A A C

    2007-04-01

    The degree of resolution of diplopia after repair of a blow-out fracture of the orbital floor varies and depends on many factors. We present six patients, each of whom had extensive fractures of the floor of the orbit that extended posteriorly to its anatomical limit. The mean (range) time for the resolution of diplopia after reconstruction was 4.4 (1-7) months. We think that its slow resolution in these patients may require preoperative counselling, and also the postoperative management of patients with extensive disruptions of the floor of the orbit posterior to the anterior limit of the inferior orbital fissure (within the deep orbit) must be carefully planned. PMID:16814905

  18. Cooling wall

    SciTech Connect

    Nosenko, V.I.

    1995-07-01

    Protecting the shells of blast furnaces is being resolved by installing cast iron cooling plates. The cooling plates become non-operational in three to five years. The problem is that defects occur in manufacturing the cooling plates. With increased volume and intensity of work placed on blast furnaces, heat on the cast iron cooling plates reduces their reliability that limits the interim repair period of blast furnaces. Scientists and engineers from the Ukraine studied this problem for several years, developing a new method of cooling the blast furnace shaft called the cooling wall. Traditional cast iron plates were replaced by a screen of steel tubes, with the area between the tubes filled with fireproof concrete. Before placing the newly developed furnace shaft into operation, considerable work was completed such as theoretical calculations, design, research of temperature fields and tension. Continual testing over many years confirms the value of this research in operating blast furnaces. The cooling wall works with water cooling as well as vapor cooling and is operating in 14 blast furnaces in the Ukraine and two in Russia, and has operated for as long as 14 years.

  19. A Case of Orbital Emphysema Associated with Frontal Sinus Pneumocele

    PubMed Central

    Sasaki, Takahiro; Yamoto, Toshikazu; Fujita, Koji; Nakao, Naoyuki

    2013-01-01

    Orbital emphysema is usually caused by trauma and fracture of an orbital bone, allowing air to pass from the sinuses into the orbit. Orbital emphysema without any significant trauma is rare. We present a case of a 67-year-old-woman who complained of left exophthalmos without any history of trauma, sneezing, or sinus surgery. Computed tomography scanning showed left orbital emphysema protruding the eyeball forward. The left frontal sinus was remarkably enlarged associated with a partial defect of the orbital roof, allowing air entry into the orbit. In addition, the frontal sinus ostium was occluded with the mucocele that served as a one-way valve between the frontal and the ethmoidal sinuses. We performed frontal craniotomy and removed the mucocele and the inner table of frontal bone to communicate the frontal sinus with the nasal cavity. After operation, her exophthalmos was improved. PMID:23943722

  20. A case of orbital emphysema associated with frontal sinus pneumocele.

    PubMed

    Sasaki, Takahiro; Yamoto, Toshikazu; Fujita, Koji; Nakao, Naoyuki

    2013-06-01

    Orbital emphysema is usually caused by trauma and fracture of an orbital bone, allowing air to pass from the sinuses into the orbit. Orbital emphysema without any significant trauma is rare. We present a case of a 67-year-old-woman who complained of left exophthalmos without any history of trauma, sneezing, or sinus surgery. Computed tomography scanning showed left orbital emphysema protruding the eyeball forward. The left frontal sinus was remarkably enlarged associated with a partial defect of the orbital roof, allowing air entry into the orbit. In addition, the frontal sinus ostium was occluded with the mucocele that served as a one-way valve between the frontal and the ethmoidal sinuses. We performed frontal craniotomy and removed the mucocele and the inner table of frontal bone to communicate the frontal sinus with the nasal cavity. After operation, her exophthalmos was improved. PMID:23943722

  1. Fracturing operations in a dry geothermal reservoir

    SciTech Connect

    Rowley, J.C.; Hendron, R.H.; Nicholson, R.W.; Pettitt, R.A.; Sinclair, A.R.

    1983-10-01

    Fracturing and completing deep wells in hot, non-porous crystalline basement rock challenges conventional equipment use, procedures, and techniques common in oil and gas and normal geothermal completions. Fracturing operations at the Fenton Hill, New Mexico, Hot Dry Rock (HDR) Geothermal Test Site initiated unique developments necessary to solve problems caused by an extremely harsh downhole environment. Two deep wells were drilled to approximately 15,000 ft (4.6 km); formation temperatures are in excess of 600/sup 0/F (315/sup 0/C). The wells were drilled during 1979-1981, inclined at 35 degrees, one above the other, and directionally drilled in an azimuthal direction orthogonal to the least principal in-situ crustal stress field. The pair of wells form the injection and production wells of an energy extraction system which will be unique in reservoir development. Hydraulic fracturing experiments to connect the two wells have used openhole packers, hydraulic jet notching of the borehole wall, cemented-in isolation liners and casing packers. Problems were encountered with hole drag, high fracture gradients, H/sub 2/S in vent back fluids, stress corrosion cracking of tubulars, and the complex nature of three-dimensional fracture growth that requires very large volumes of injected water. Two fractured zones have been formed by hydraulic fracturing and defined by close-in, borehole deployed, microseismic detectors.

  2. Fracture characterisation using geoelectric null-arrays

    NASA Astrophysics Data System (ADS)

    Falco, Pierik; Negro, François; Szalai, Sándor; Milnes, Ellen

    2013-06-01

    The term "geoelectric null-array" is used for direct current electrode configurations yielding a potential difference of zero above a homogeneous half-space. This paper presents a comparative study of the behaviour of three null-arrays, midpoint null-array (MAN), Wenner-γ null-array and Schlumberger null-array in response to a fracture, both in profiling and in azimuthal mode. The main objective is to determine which array(s) best localise fractures or best identify their orientation. Forward modelling of the three null-arrays revealed that the Wenner-γ and Schlumberger null-arrays localise vertical fractures the most accurately, whilst the midpoint null-array combined with the Schlumberger null-array allows accurate orientation of a fracture. Numerical analysis then served as a basis to interpret the field results. Field test measurements were carried out above a quarry in Les Breuleux (Switzerland) with the three null-arrays and classical arrays. The results were cross-validated with quarry-wall geological mapping. In real field circumstances, the Wenner-γ null-array proved to be the most efficient and accurate in localising fractures. The orientations of the fractures according to the numerical results were most efficiently determined with the midpoint null-array, whilst the Schlumberger null-array adds accuracy to the results. This study shows that geoelectrical null-arrays are more suitable than classical arrays for the characterisation of fracture geometry.

  3. Fracture channel waves

    SciTech Connect

    Nihei, K.T.; Yi, W.; Myer, L.R.; Cook, N.G.; Schoenberg, M.

    1999-03-01

    The properties of guided waves which propagate between two parallel fractures are examined. Plane wave analysis is used to obtain a dispersion equation for the velocities of fracture channel waves. Analysis of this equation demonstrates that parallel fractures form an elastic waveguide that supports two symmetric and two antisymmetric dispersive Rayleigh channel waves, each with particle motions and velocities that are sensitive to the normal and tangential stiffnesses of the fractures. These fracture channel waves degenerate to shear waves when the fracture stiffnesses are large, to Rayleigh waves and Rayleigh-Lamb plate waves when the fracture stiffnesses are low, and to fracture interface waves when the fractures are either very closely spaced or widely separated. For intermediate fracture stiffnesses typical of fractured rock masses, fracture channel waves are dispersive and exhibit moderate to strong localization of guided wave energy between the fractures. The existence of these waves is examined using laboratory acoustic measurements on a fractured marble plate. This experiment confirms the distinct particle motion of the fundamental antisymmetric fracture channel wave (A{sub 0} mode) and demonstrates the ease with which a fracture channel wave can be generated and detected. {copyright} 1999 American Geophysical Union

  4. Crustal Fractures of Ophir Planum

    NASA Technical Reports Server (NTRS)

    2002-01-01

    (Released 29 April 2002) The Science This THEMIS image covers a tract of plateau territory called Ophir Planum. The most obvious features in this scene are the fractures (ranging from 1 to 5 km wide) running from the upper left to lower right. Localized rifting and deep-seated tension fracturing of the crust probably formed these cracks. The wall rock displayed in the upper part of the cliffs appears to be layered. The southwest-facing wall of the largest and uppermost fracture has classic spur and gully topography. This type of topography is created by differing amounts of erosion. Also seen in this image are some scattered impact craters and some dark wind streaks in the lower right. The Ophir Planum plateau separates two separate smaller canyon systems, not visible in this image, (Candor Chasma to the north and Melas Chasma to the south) in the Valles Marineris canyon complex. The whole Valles Marineris canyon system extends some 4,000 km across the equatorial realms of Mars. For comparison, this would stretch from New York City to San Francisco. The Story Plateaus and spurs might make you think of cowboys on the open plain. 'Spurs' in this context, however, are simply ridges that can be seen on the side of the southwest-facing wall of the large fracture that splits the terrain. Gullies stretch down this slope as well. Both of these features are caused by erosion, which is a mild force of change compared to whatever tension cracked the crust and ripped apart the land. The wall rock displayed in the upper part of the cliffs appears to be layered, suggesting that different kinds of rocks and minerals can be found in each banded zone. The Ophir Planum plateau separates two separate canyon systems in the Valles Marineris complex, the largest canyon in the solar system. If Valles Marineris were on Earth, it would stretch from New York City all the way to San Francisco. That will give you some idea of the geological forces that have acted upon the planet over time

  5. Detail view of the starboard mid deck wall of the ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Detail view of the starboard mid deck wall of the Orbiter Discovery showing Operational Sleeping Bags attached horizontally to the wall for the crew sleep period. If it is required as part of a mission's manifest a four-tiered rigid sleep station can be installed. This photograph was taken at Kennedy Space Center. - Space Transportation System, Orbiter Discovery (OV-103), Lyndon B. Johnson Space Center, 2101 NASA Parkway, Houston, Harris County, TX

  6. Modelling of Local Necking and Fracture in Aluminium Alloys

    NASA Astrophysics Data System (ADS)

    Achani, D.; Eriksson, M.; Hopperstad, O. S.; Lademo, O.-G.

    2007-05-01

    Non-linear Finite Element simulations are extensively used in forming and crashworthiness studies of automotive components and structures in which fracture need to be controlled. For thin-walled ductile materials, the fracture-related phenomena that must be properly represented are thinning instability, ductile fracture and through-thickness shear instability. Proper representation of the fracture process relies on the accuracy of constitutive and fracture models and their parameters that need to be calibrated through well defined experiments. The present study focuses on local necking and fracture which is of high industrial importance, and uses a phenomenological criterion for modelling fracture in aluminium alloys. As an accurate description of plastic anisotropy is important, advanced phenomenological constitutive equations based on the yield criterion YLD2000/YLD2003 are used. Uniaxial tensile tests and disc compression tests are performed for identification of the constitutive model parameters. Ductile fracture is described by the Cockcroft-Latham fracture criterion and an in-plane shear tests is performed to identify the fracture parameter. The reason is that in a well designed in-plane shear test no thinning instability should occur and it thus gives more direct information about the phenomenon of ductile fracture. Numerical simulations have been performed using a user-defined material model implemented in the general-purpose non-linear FE code LS-DYNA. The applicability of the model is demonstrated by correlating the predicted and experimental response in the in-plane shear tests and additional plane strain tension tests.

  7. Modelling of Local Necking and Fracture in Aluminium Alloys

    SciTech Connect

    Achani, D.; Eriksson, M.; Hopperstad, O. S.; Lademo, O.-G.

    2007-05-17

    Non-linear Finite Element simulations are extensively used in forming and crashworthiness studies of automotive components and structures in which fracture need to be controlled. For thin-walled ductile materials, the fracture-related phenomena that must be properly represented are thinning instability, ductile fracture and through-thickness shear instability. Proper representation of the fracture process relies on the accuracy of constitutive and fracture models and their parameters that need to be calibrated through well defined experiments. The present study focuses on local necking and fracture which is of high industrial importance, and uses a phenomenological criterion for modelling fracture in aluminium alloys. As an accurate description of plastic anisotropy is important, advanced phenomenological constitutive equations based on the yield criterion YLD2000/YLD2003 are used. Uniaxial tensile tests and disc compression tests are performed for identification of the constitutive model parameters. Ductile fracture is described by the Cockcroft-Latham fracture criterion and an in-plane shear tests is performed to identify the fracture parameter. The reason is that in a well designed in-plane shear test no thinning instability should occur and it thus gives more direct information about the phenomenon of ductile fracture. Numerical simulations have been performed using a user-defined material model implemented in the general-purpose non-linear FE code LS-DYNA. The applicability of the model is demonstrated by correlating the predicted and experimental response in the in-plane shear tests and additional plane strain tension tests.

  8. Spontaneous Decompression Fracture in Thyroid Eye Disease.

    PubMed

    Richardson, Marc A; Lewis, Kyle T

    2014-12-01

    This is a case of a 44-year-old female with a history of Graves' orbitopathy presented to the emergency department after waking from a nap with sudden onset of left facial and periorbital swelling, ecchymosis, and subconjunctival hemorrhage. A CT scan obtained in the emergency department revealed a left blowout fracture and enlarged extraocular muscles. The patient lives with her mother and both adamantly denied any trauma. The patient had sustained a spontaneous orbital fracture; a process reported but few times in the medical literature. PMID:25473888

  9. New instrument for orbital anthropometry.

    PubMed

    Kohout, M; Pai, L; Berenguer, B; Tayler, P; Pracharktam, N; Mulliken, J B

    1998-06-01

    A new instrument for orbital anthropometry is described. It consists of the base for a slit-lamp upon which the patient's head rests and rulers mounted on three independently movable axes. The z-axis probe is used to measure sagittal relationship between the corneal apices and points on the orbital perimeter. The instrument was tested against a sliding caliper and its accuracy was found to be within 0.2 mm or 2%. Intra- and inter-observer reliability were assessed by repeated measurements of two subjects by three observers. The intra-observer reliability was 0.99. Variations between observers was not significantly different for points orbitale inferius (oi), nasion (n), and orbitale superius (os), however, there was a statistically significant difference for measurement of orbitale laterale (ol). The correlation between anthropometric readings for lateral orbital wall to apex corneal (ol-ac) and CT scans for the same landmarks was assessed. Analysis of variance showed no difference between the measurement methods. This anthropometer is convenient and accurate for measurement of the sagittal orbital-globe relationships. A disadvantage is that it cannot be used intraoperatively. PMID:9702637

  10. Synkinematic quartz cementation in partially open fractures in sandstones

    NASA Astrophysics Data System (ADS)

    Ukar, Estibalitz; Laubach, Stephen E.; Fall, Andras; Eichhubl, Peter

    2014-05-01

    Faults and networks of naturally open fractures can provide open conduits for fluid flow, and may play a significant role in hydrocarbon recovery, hydrogeology, and CO2 sequestration. However, sandstone fracture systems are commonly infilled, at least to some degree, by quartz cement, which can stiffen and occlude fractures. Such cement deposits can systematically reduce the overall permeability enhancement due to open fractures (by reducing open fracture length) and result in permeability anisotropies. Thus, it is important to identify the factors that control the precipitation of quartz in fractures in order to identify potential fluid conduits under the present-day stress field. In many sandstones, quartz nucleates syntaxially on quartz grain or cement substrate of the fracture wall, and extends between fracture walls only locally, forming pillars or bridges. Scanning electron microscope cathodoluminescence (SEM-CL) images reveal that the core of these bridges are made up of bands of broken and resealed cement containing wall-parallel fluid inclusion planes. The fluid inclusion-rich core is usually surrounded by a layer of inclusion-poor clear quartz that comprises the lateral cement. Such crack-seal textures indicate that this phase was precipitating while the fractures were actively opening (synkinematic growth). Rapid quartz accumulation is generally believed to require temperatures of 80°C or more. Fluid inclusion thermometry and Raman spectroscopy of two-phase aqueous fluid-inclusions trapped in crack-seal bands may be used to track the P-T-X evolution of pore fluids during fracture opening and crack-seal cementation of quartz. Quartz cement bridges across opening mode fractures in the Cretaceous Travis Peak Formation of the tectonically quiescent East Texas Basin indicate individual fractures opened over a 48 m.y. time span at rates of 16-23 µm/m.y. Similarly, the Upper Cretaceous Mesaverde Group in the Piceance Basin, Colorado contains fractures that

  11. Paratrooper's Ankle Fracture: Posterior Malleolar Fracture

    PubMed Central

    Young, Ki Won; Cho, Jae Ho; Kim, Hyung Seuk; Cho, Hun Ki; Lee, Kyung Tai

    2015-01-01

    Background We assessed the frequency and types of ankle fractures that frequently occur during parachute landings of special operation unit personnel and analyzed the causes. Methods Fifty-six members of the special force brigade of the military who had sustained ankle fractures during parachute landings between January 2005 and April 2010 were retrospectively analyzed. The injury sites and fracture sites were identified and the fracture types were categorized by the Lauge-Hansen and Weber classifications. Follow-up surveys were performed with respect to the American Orthopedic Foot and Ankle Society ankle-hindfoot score, patient satisfaction, and return to preinjury activity. Results The patients were all males with a mean age of 23.6 years. There were 28 right and 28 left ankle fractures. Twenty-two patients had simple fractures and 34 patients had comminuted fractures. The average number of injury and fractures sites per person was 2.07 (116 injuries including a syndesmosis injury and a deltoid injury) and 1.75 (98 fracture sites), respectively. Twenty-three cases (41.07%) were accompanied by posterior malleolar fractures. Fifty-five patients underwent surgery; of these, 30 had plate internal fixations. Weber type A, B, and C fractures were found in 4, 38, and 14 cases, respectively. Based on the Lauge-Hansen classification, supination-external rotation injuries were found in 20 cases, supination-adduction injuries in 22 cases, pronation-external rotation injuries in 11 cases, tibiofibular fractures in 2 cases, and simple medial malleolar fractures in 2 cases. The mean follow-up period was 23.8 months, and the average follow-up American Orthopedic Foot and Ankle Society ankle-hindfoot score was 85.42. Forty-five patients (80.36%) reported excellent or good satisfaction with the outcome. Conclusions Posterior malleolar fractures occurred in 41.07% of ankle fractures sustained in parachute landings. Because most of the ankle fractures in parachute injuries were

  12. Closeup view of the mid deck aft wall of the ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Close-up view of the mid deck aft wall of the Orbiter Discovery showing a mission specific configuration of stowage lockers within the modular system designed for maximum flexibility. This photograph was taken at Kennedy Space Center. - Space Transportation System, Orbiter Discovery (OV-103), Lyndon B. Johnson Space Center, 2101 NASA Parkway, Houston, Harris County, TX

  13. HVI Ballistic Performance Characterization of Non-Parallel Walls

    NASA Technical Reports Server (NTRS)

    Bohl, William; Miller, Joshua; Christiansen, Eric

    2012-01-01

    The Double-Wall, "Whipple" Shield [1] has been the subject of many hypervelocity impact studies and has proven to be an effective shield system for Micro-Meteoroid and Orbital Debris (MMOD) impacts for spacecraft. The US modules of the International Space Station (ISS), with their "bumper shields" offset from their pressure holding rear walls provide good examples of effective on-orbit use of the double wall shield. The concentric cylinder shield configuration with its large radius of curvature relative to separation distance is easily and effectively represented for testing and analysis as a system of two parallel plates. The parallel plate double wall configuration has been heavily tested and characterized for shield performance for normal and oblique impacts for the ISS and other programs. The double wall shield and principally similar Stuffed Whipple Shield are very common shield types for MMOD protection. However, in some locations with many spacecraft designs, the rear wall cannot be modeled as being parallel or concentric with the outer bumper wall. As represented in Figure 1, there is an included angle between the two walls. And, with a cylindrical outer wall, the effective included angle constantly changes. This complicates assessment of critical spacecraft components located within outer spacecraft walls when using software tools such as NASA's BumperII. In addition, the validity of the risk assessment comes into question when using the standard double wall shield equations, especially since verification testing of every set of double wall included angles is impossible.

  14. Predicting zygoma fractures from baseball impact.

    PubMed

    Cormier, Joseph M; Stitzel, Joel D; Hurst, William J; Porta, David J; Jones, Jeryl; Duma, Stefan M

    2006-01-01

    The purpose of this study is to develop injury risk functions that predict zygoma fracture based on baseball type and impact velocity. Zygoma fracture strength data from published experiments were mapped with the force exerted by a baseball on the orbit as a function of ball velocity. Using a normal distribution, zygoma fracture risk functions were developed. Experimental evaluation of these risk functions was performed using six human cadaver tests and two baseballs of different stiffness values. High speed video measured the baseball impact velocity. Post test analysis of the cadaver skulls was performed using CT imaging including three-dimensional reconstruction as well as autopsy. The developed injury risk functions accurately identify the risk of zygoma fracture as a result of baseball impact. The experimental results validated the zygoma risk functions at the lower and upper levels. The injuries observed in the post test analysis included fractures of the zygomatic arch, frontal process and the maxilla, zygoma suture, with combinations of these creating comminuted, tripod fractures of the zygoma. Tests with a softer baseball did result in injury but these had fewer resulting zygoma bone fragments and occurred at velocities 50% higher than the major league ball. PMID:16817599

  15. Ocular and orbital trauma from water balloon slingshots: a clinical, epidemiological, experimental, and theoretical study.

    PubMed Central

    Bullock, J D; Johnson, D A; Ballal, D R; Bullock, R J

    1996-01-01

    PURPOSE: To report the clinical findings of 17 patients with ocular/orbital injuries produced by launched water balloons; to determine water balloon kinetic energies in experimental and theoretical studies. METHODS: Six case histories are presented, 1 case was retrieved from the medical literature, and 10 cases were reported to the National Injury Information Clearinghouse of the United States Consumer Product Safety Commission. The energies were determined by field trials and calculations. RESULTS: Injuries included orbital contusions and hematomas, facial hypesthesia, eyelid lacerations, subconjunctival hemorrhages, corneal edema and abrasion, hyphemas, traumatic iritis, iris sphincter ruptures, iris atrophy, angle recession, iridodialyses, traumatic cataract, vitreous hemorrhages, retinal hemorrhages, macular hole formation, optic atrophy, and bony orbital wall fractures. Epidemiological analysis revealed that children and young adults, more often males, were injured, most commonly in the warm weather months (May through September). In field trials, maximum water balloon velocities ranged from 38 to 41 m/sec (85 to 92 mph) with kinetic energies from 176 to 245 J; by calculation, maximum velocities ranged from 42 to 54 m/sec (95 to 121 mph) with kinetic energies from 141 to 232 J. In a field demonstration a 300-g water balloon launched horizontally from a distance of 20 ft exploded a 12-kg watermelon. Classic physics calculations are presented to explain the complex bio-mechanical interactions between the water balloon and the eye. CONCLUSION: Kinetic energies of launched water balloons are comparable to or greater than kinetic energies experienced with a variety of common objects, including file bullets, which are well known to cause serious ocular and orbital injuries. In addition, these energies are far in excess of those required to perforate a cornea (0.7 to 1.7 J), rupture a globe (1 to 5.3 J), or fracture the bony orbit (1.8 to 14.7 j). Thus, this study

  16. Epidemiology of fragility fractures.

    PubMed

    Friedman, Susan M; Mendelson, Daniel Ari

    2014-05-01

    As the world population of older adults-in particular those over age 85-increases, the incidence of fragility fractures will also increase. It is predicted that the worldwide incidence of hip fractures will grow to 6.3 million yearly by 2050. Fractures result in significant financial and personal costs. Older adults who sustain fractures are at risk for functional decline and mortality, both as a function of fractures and their complications and of the frailty of the patients who sustain fractures. Identifying individuals at high risk provides an opportunity for both primary and secondary prevention. PMID:24721358

  17. Fracture in the chin area: an unusual case of mandibular torus fracture.

    PubMed

    Saura-Ingles, A; Garcia-Ballesta, C; Pérez-Lajarin, L; López-Jornet, P

    2005-07-01

    Mandibular torus fracture as a result of accidental trauma has not been reported to date in the dental literature. This study describes the case of a young adult male who suffered multiple fractures affecting the teeth and mandibular torus secondary to chin area trauma due to a bicycle accident; the first manifestation of bone damage being left unilateral paraesthesia of the lip. An occlusal x-ray study of the affected area was made to evaluate possible fracture, as unlike centred periapical x-rays and orthopantomography, it is able to reveal the existence of a fracture line of the alveolar wall. In the associated presence of paraesthesia, a computed tomographic study is advisable. PMID:16003417

  18. Fracture identification based on remote detection acoustic reflection logging

    NASA Astrophysics Data System (ADS)

    Zhang, Gong; Li, Ning; Guo, Hong-Wei; Wu, Hong-Liang; Luo, Chao

    2015-12-01

    Fracture identification is important for the evaluation of carbonate reservoirs. However, conventional logging equipment has small depth of investigation and cannot detect rock fractures more than three meters away from the borehole. Remote acoustic logging uses phase-controlled array-transmitting and long sound probes that increase the depth of investigation. The interpretation of logging data with respect to fractures is typically guided by practical experience rather than theory and is often ambiguous. We use remote acoustic reflection logging data and high-order finite-difference approximations in the forward modeling and prestack reverse-time migration to image fractures. First, we perform forward modeling of the fracture responses as a function of the fracture-borehole wall distance, aperture, and dip angle. Second, we extract the energy intensity within the imaging area to determine whether the fracture can be identified as the formation velocity is varied. Finally, we evaluate the effect of the fracture-borehole distance, fracture aperture, and dip angle on fracture identification.

  19. Lunar Reconnaissance Orbiter Orbit Determination Accuracy Analysis

    NASA Technical Reports Server (NTRS)

    Slojkowski, Steven E.

    2014-01-01

    Results from operational OD produced by the NASA Goddard Flight Dynamics Facility for the LRO nominal and extended mission are presented. During the LRO nominal mission, when LRO flew in a low circular orbit, orbit determination requirements were met nearly 100% of the time. When the extended mission began, LRO returned to a more elliptical frozen orbit where gravity and other modeling errors caused numerous violations of mission accuracy requirements. Prediction accuracy is particularly challenged during periods when LRO is in full-Sun. A series of improvements to LRO orbit determination are presented, including implementation of new lunar gravity models, improved spacecraft solar radiation pressure modeling using a dynamic multi-plate area model, a shorter orbit determination arc length, and a constrained plane method for estimation. The analysis presented in this paper shows that updated lunar gravity models improved accuracy in the frozen orbit, and a multiplate dynamic area model improves prediction accuracy during full-Sun orbit periods. Implementation of a 36-hour tracking data arc and plane constraints during edge-on orbit geometry also provide benefits. A comparison of the operational solutions to precision orbit determination solutions shows agreement on a 100- to 250-meter level in definitive accuracy.

  20. Infant skull fracture (image)

    MedlinePlus

    Skull fractures may occur with head injuries. Although the skull is both tough and resilient and provides excellent ... or blow can result in fracture of the skull and may be accompanied by injury to the ...

  1. Fractures in anisotropic media

    NASA Astrophysics Data System (ADS)

    Shao, Siyi

    Rocks may be composed of layers and contain fracture sets that cause the hydraulic, mechanical and seismic properties of a rock to be anisotropic. Coexisting fractures and layers in rock give rise to competing mechanisms of anisotropy. For example: (1) at low fracture stiffness, apparent shear-wave anisotropy induced by matrix layering can be masked or enhanced by the presence of a fracture, depending on the fracture orientation with respect to layering, and (2) compressional-wave guided modes generated by parallel fractures can also mask the presence of matrix layerings for particular fracture orientations and fracture specific stiffness. This report focuses on two anisotropic sources that are widely encountered in rock engineering: fractures (mechanical discontinuity) and matrix layering (impedance discontinuity), by investigating: (1) matrix property characterization, i.e., to determine elastic constants in anisotropic solids, (2) interface wave behavior in single-fractured anisotropic media, (3) compressional wave guided modes in parallel-fractured anisotropic media (single fracture orientation) and (4) the elastic response of orthogonal fracture networks. Elastic constants of a medium are required to understand and quantify wave propagation in anisotropic media but are affected by fractures and matrix properties. Experimental observations and analytical analysis demonstrate that behaviors of both fracture interface waves and compressional-wave guided modes for fractures in anisotropic media, are affected by fracture specific stiffness (controlled by external stresses), signal frequency and relative orientation between layerings in the matrix and fractures. A fractured layered medium exhibits: (1) fracture-dominated anisotropy when the fractures are weakly coupled; (2) isotropic behavior when fractures delay waves that are usually fast in a layered medium; and (3) matrix-dominated anisotropy when the fractures are closed and no longer delay the signal. The

  2. Bone fracture repair - slideshow

    MedlinePlus

    ... page: //medlineplus.gov/ency/presentations/100077.htm Bone fracture repair - series To use the sharing features on ... to slide 4 out of 4 Indications Overview Fractures of the bones are classified in a number ...

  3. Forearm Fractures in Children

    MedlinePlus

    .org Forearm Fractures in Children The forearm is the part of the arm between the wrist and the elbow. It is ... two bones: the radius and the ulna. Forearm fractures are common in childhood, accounting for more than ...

  4. Nasal fracture - aftercare

    MedlinePlus

    ... page: //medlineplus.gov/ency/patientinstructions/000554.htm Nasal fracture - aftercare To use the sharing features on this ... that gives your nose its shape. A nasal fracture occurs when the bony part of your nose ...

  5. Nasal fracture (image)

    MedlinePlus

    A nasal fracture is a break in the bone over the ridge of the nose. It usually results from a blunt ... and is one of the most common facial fracture. Symptoms of a broken nose include pain, blood ...

  6. Hip fracture surgery

    MedlinePlus

    ... neck fracture repair; Trochanteric fracture repair; Hip pinning surgery; Osteoarthritis-hip ... You may receive general anesthesia before this surgery. This means ... spinal anesthesia. With this kind of anesthesia, medicine is ...

  7. Pediatric Open Fractures.

    PubMed

    Trionfo, Arianna; Cavanaugh, Priscilla K; Herman, Martin J

    2016-07-01

    Open fractures in children are rare and are typically associated with better prognoses compared with their adult equivalents. Regardless, open fractures pose a challenge because of the risk of healing complications and infection, leading to significant morbidity even in the pediatric population. Therefore, the management of pediatric open fractures requires special consideration. This article comprehensively reviews the initial evaluation, classification, treatment, outcomes, and controversies of open fractures in children. PMID:27241379

  8. Fractured tooth (image)

    MedlinePlus

    A tooth can be chipped or fractured during an accident or a bad fall. A tooth that is chipped or not badly fractured can usually be handled on a nonemergency basis. A tooth that is badly fractured may have exposed nerve ...

  9. OEX - Use of the Shuttle Orbiter as a research vehicle

    NASA Technical Reports Server (NTRS)

    Jones, J. J.

    1981-01-01

    The Orbiter Experiments Program to provide research instrumentation on the Shuttle Orbiter is discussed. Flight aerodynamic problems such as ground-based data limitations, rarefied flow effects, body flap and control surface effectiveness, and windward surface heat transfer are reviewed. Experiments currently under development are described, including experiments on tile gaps and wall catalytic effects which provide the opportunity to obtain data not available in ground facilities and apply the results to improvements in the Orbiter's thermal protection system. Such experiments combined with other instrumentation on the Orbiter should provide benchmark flight data which can make a significant impact on the design of future space transportation systems.

  10. Dzyaloshinskii-Moriya Domain Walls in Nanotubes

    NASA Astrophysics Data System (ADS)

    Tretiakov, Oleg; Goussev, Arseni; Robbins, J. M.; Slastikov, Valeriy

    2015-03-01

    We study domain walls in thin ferromagnetic nanotubes with Dzyaloshinskii-Moriya interaction (DMI). Dramatic effects arise from the interplay of space curvature and spin-orbit induced DMI on the domain wall structure in these systems. The domain walls become narrower in systems with DMI and curvature. Moreover, the domain walls created in such nanotubes can propagate without Walker breakdown for arbitrary applied currents, thus allowing for a robust and controlled domain-wall motion. The domain-wall velocity is directly proportional to the non-adiabatic spin transfer torque current term and is insensitive to the adiabatic current term. Application of an external magnetic field along the nanotube axis triggers rich dynamical response of the curved domain wall. In particular, we show that the propagation velocity is a non-linear function of both the applied field and DMI, and strongly depends on the orientation and chirality of the wall. We acknowledge support by the Grants-in-Aid for Scientific Research (No. 25800184 and No. 25247056) from the MEXT, Japan and SpinNet.

  11. Impact of normal stress on multiphase flow through rough fractures

    NASA Astrophysics Data System (ADS)

    Alves da Silva Junior, J.; Kang, P. K.; Yang, Z.; Cueto-Felgueroso, L.; Juanes, R.

    2015-12-01

    Fluid flow and transport through geologic fractures plays a key role in several areas such as groundwater hydrology, geothermal energy, oil and gas production, CO2 sequestration and nuclear waste disposal. High-permeability zones associated with fracture corridors often serve as fast fluid conduits for both single and multiphase flow in otherwise low-permeability media. When multiphase flow occurs, the presence of one phase interferes with the flow of the other phase, resulting in complex displacement patterns through the fracture, and macroscopic descriptors (such as fracture-scale capillary pressure and relative permeability) that depend on the phase concentration of both phases. Here, we investigate the impact of normal stress on single and multiphase flow through rough-walled fractures: (1) we generate synthetic aperture fields that honor the fractal roughness structure observed in real fractures; (2) we model the effect of normal stress on the fracture aperture geometry by solving the contact problem between fracture walls; and (3) we use invasion percolation with trapping to model immiscible fluid displacement and then compute relative permeability numerically for each stress scenario. Our results indicate that normal stress increases the amount of contact area in the fracture wall, which results in an increase of the tortuosity of the available path for fluid displacement. Increasing normal stress results in low relative permeability for the wetting phase due to a decrease of the available path for fluid flow, and therefore a small amount of non-wetting fluid has a large impact on the flow of the wetting fluid. We find that the relative permeability of the non-wetting fluid shows less variation with stress than the wetting fluid, and that both fluids exhibit strong phase interference at intermediate saturations. Finally, we show early results from our experimental work currently underway to validate the modeling results.

  12. Land-Surface Subsidence and Open Bedrock Fractures in the Tully Valley, Onondaga County, New York

    USGS Publications Warehouse

    Hackett, William R.; Gleason, Gayle C.; Kappel, William M.

    2009-01-01

    Open bedrock fractures were mapped in and near two brine field areas in Tully Valley, New York. More than 400 open fractures and closed joints were mapped for dimension, orientation, and distribution along the east and west valley walls adjacent to two former brine fields. The bedrock fractures are as much as 2 feet wide and over 50 feet deep, while linear depressions in the soil, which are 3 to 10 feet wide and 3 to 6 feet deep, indicate the presence of open bedrock fractures below the soil. The fractures are probably the result of solution mining of halite deposits about 1,200 feet below the land surface.

  13. Dry fracture method for simultaneous measurement of in-situ stress state and material properties

    SciTech Connect

    Serata, S.; Oka, S.; Kikuchi, S.

    1996-04-01

    Based on the dry fracture principle, a computerized borehole probe has been developed to measure stress state and material properties, simultaneously. The probe is designed to obtain a series of measurements in a continuing sequence along a borehole length, without any interruptive measures, such as resetting packers, taking indentation of borehole wall, overcoming, etc. The new dry fracture probe for the single fracture method is designed to overcome the difficulties posed by its ancestor which was based on the double fracture method. The accuracy of the single fracture method is confirmed by a close agreement with the theory, FE modeling and laboratory testing.

  14. 3D characterization of the fracture network in a deformed chalk reservoir analogue: The Lagerdorf case

    SciTech Connect

    Koestler, A.G.; Reksten, K.

    1994-12-31

    Quantitative descriptions of the 3D fracture networks in terms of connectivity, fracture types, fracture surface roughness and flow characteristics are necessary for reservoir evaluation, management, and enhanced oil recovery programs of fractured reservoirs. For a period of 2 years, a research project focused on an analogue to fractured chalk reservoirs excellently exposed near Laegerdorf, NW Germany. Upper Cretaceous chalk has been uplifted and deformed by an underlying salt diapir, and is now exploited for the cement industry. In the production wall of a quarry, the fracture network of the deformed chalk was characterized and mapped at different scales. The wall was scraped off as chalk exploitation proceeded, continuously revealing new sections through the faulted and fractured chalk body. A 230 m long part of the 35m high production wall was investigated during its recess of 25m. The large amount of fracture data were analyzed with respect to parameters such as fracture density distribution, orientation- and length distribution, and in terms of the representativity of data sets collected from restricted rock volumes. This 3D description and analysis of a fracture network revealed quantitative generic parameters of importance for modeling chalk reservoirs with less data and lower data quality.

  15. Channel Wall Landslides

    NASA Technical Reports Server (NTRS)

    2005-01-01

    [figure removed for brevity, see original site]

    The multiple landslides in this VIS image occur along a steep channel wall. Note the large impact crater in the context image. The formation of the crater may have initially weakened that area of the surface prior to channel formation.

    Image information: VIS instrument. Latitude -2.7, Longitude 324.8 East (35.2 West). 19 meter/pixel resolution.

    Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.

    NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.

  16. Talus fractures: surgical principles.

    PubMed

    Rush, Shannon M; Jennings, Meagan; Hamilton, Graham A

    2009-01-01

    Surgical treatment of talus fractures can challenge even the most skilled foot and ankle surgeon. Complicated fracture patterns combined with joint dislocation of variable degrees require accurate assessment, sound understanding of principles of fracture care, and broad command of internal fixation techniques needed for successful surgical care. Elimination of unnecessary soft tissue dissection, a low threshold for surgical reduction, liberal use of malleolar osteotomy to expose body fracture, and detailed attention to fracture reduction and joint alignment are critical to the success of treatment. Even with the best surgical care complications are common and seem to correlate with injury severity and open injuries. PMID:19121756

  17. Lunar orbiting prospector

    NASA Technical Reports Server (NTRS)

    1988-01-01

    One of the prime reasons for establishing a manned lunar presence is the possibility of using the potential lunar resources. The Lunar Orbital Prospector (LOP) is a lunar orbiting platform whose mission is to prospect and explore the Moon from orbit in support of early lunar colonization and exploitation efforts. The LOP mission is divided into three primary phases: transport from Earth to low lunar orbit (LLO), operation in lunar orbit, and platform servicing in lunar orbit. The platform alters its orbit to obtain the desired surface viewing, and the orbit can be changed periodically as needed. After completion of the inital remote sensing mission, more ambitious and/or complicated prospecting and exploration missions can be contemplated. A refueled propulsion module, updated instruments, or additional remote sensing packages can be flown up from the lunar base to the platform.

  18. Percolation and permeability of heterogeneous fracture networks

    NASA Astrophysics Data System (ADS)

    Adler, Pierre; Mourzenko, Valeri; Thovert, Jean-François

    2013-04-01

    Natural fracture fields are almost necessarily heterogeneous with a fracture density varying with space. Two classes of variations are quite frequent. In the first one, the fracture density is decreasing from a given surface; the fracture density is usually (but not always see [1]) an exponential function of depth as it has been shown by many measurements. Another important example of such an exponential decrease consists of the Excavated Damaged Zone (EDZ) which is created by the excavation process of a gallery [2,3]. In the second one, the fracture density undergoes some local random variations around an average value. This presentation is mostly focused on the first class and numerical samples are generated with an exponentially decreasing density from a given plane surface. Their percolation status and hydraulic transmissivity can be calculated by the numerical codes which are detailed in [4]. Percolation is determined by a pseudo diffusion algorithm. Flow determination necessitates the meshing of the fracture networks and the discretisation of the Darcy equation by a finite volume technique; the resulting linear system is solved by a conjugate gradient algorithm. Only the flow properties of the EDZ along the directions which are parallel to the wall are of interest when a pressure gradient parallel to the wall is applied. The transmissivity T which relates the total flow rate per unit width Q along the wall through the whole fractured medium to the pressure gradient grad p, is defined by Q = - T grad p/mu where mu is the fluid viscosity. The percolation status and hydraulic transmissivity are systematically determined for a wide range of decay lengths and anisotropy parameters. They can be modeled by comparison with anisotropic fracture networks with a constant density. A heuristic power-law model is proposed which accurately describes the results for the percolation threshold over the whole investigated range of heterogeneity and anisotropy. Then, the data

  19. Preliminary orbital parallax catalog

    NASA Technical Reports Server (NTRS)

    Halliwell, M.

    1981-01-01

    The study is undertaken to calibrate the more reliable parallaxes derived from a comparison of visual and spectroscopic orbits and to encourage observational studies of other promising binaries. The methodological techniques used in computing orbital parallaxes are analyzed. Tables summarizing orbital data and derived system properties are then given. Also given is a series of detailed discussions of the 71 individual systems included in the tables. Data are listed for 57 other systems which are considered promising candidates for eventual orbital parallax determination.

  20. Epidemiology of clavicle fractures.

    PubMed

    Postacchini, Franco; Gumina, Stefano; De Santis, Pierfrancesco; Albo, Francesco

    2002-01-01

    An epidemiologic study of 535 isolated clavicle fractures treated in a hospital of a large metropolis during an 11-year period was performed. Data regarding patient's age and sex, side involved, mechanism of injury, and season in which the fracture occurred were obtained from the clinical records. Radiographic classification was performed with the Allman system. Clavicle fractures represented 2.6% of all fractures and 44% of those in the shoulder girdle. Most patients were men (68%), and the left side was involved in 61% of cases. Fractures of the middle third of the clavicle, which were the most common (81%), were displaced in 48% of cases and comminuted in 19%. Fractures of the medial third were the least common (2%). The prevalence of midclavicular fractures was found to decrease progressively with age, starting from the first decade of life when they represented 88.2% of all clavicle fractures and were undisplaced in 55.5% of cases. In adults, the incidence of displaced fractures, independent of location, was higher than that of undisplaced fractures. Traffic accidents were the most common cause of the injury. In the period under study, the incidence of fractures showed no significant change over time and no seasonal variation. PMID:12378163

  1. Mechanics of Hydraulic Fractures

    NASA Astrophysics Data System (ADS)

    Detournay, Emmanuel

    2016-01-01

    Hydraulic fractures represent a particular class of tensile fractures that propagate in solid media under pre-existing compressive stresses as a result of internal pressurization by an injected viscous fluid. The main application of engineered hydraulic fractures is the stimulation of oil and gas wells to increase production. Several physical processes affect the propagation of these fractures, including the flow of viscous fluid, creation of solid surfaces, and leak-off of fracturing fluid. The interplay and the competition between these processes lead to multiple length scales and timescales in the system, which reveal the shifting influence of the far-field stress, viscous dissipation, fracture energy, and leak-off as the fracture propagates.

  2. Studies of Transport Properties of Fractures: Final Report

    SciTech Connect

    Stephen R. Brown

    2006-06-30

    We proposed to study several key factors controlling the character and evolution of fracture system permeability and transport processes. We suggest that due to surface roughness and the consequent channeling in single fractures and in fracture intersections, the tendency of a fracture system to plug up, remain permeable, or for permeability to increase due to chemical dissolution/precipitation conditions will depend strongly on the instantaneous flow channel geometry. This geometry will change as chemical interaction occurs, thus changing the permeability through time. To test this hypothesis and advance further understanding toward a predictive capability, we endeavored to physically model and analyze several configurations of flow and transport of inert and chemically active fluids through channels in single fractures and through fracture intersections. This was an integrated program utilizing quantitative observations of fractures and veins in drill core, quantitative and visual observations of flow and chemical dissolution and precipitation within replicas of real rough-walled fractures and fracture intersections, and numerical modeling via lattice Boltzmann methods.

  3. SEASAT B orbit synthesis

    NASA Technical Reports Server (NTRS)

    Rea, F. G.; Warmke, J. M.

    1976-01-01

    Addition were made to Battelle's Interactive Graphics Orbit Selection (IGOS) program; IGOS was exercised via telephone lines from JPL, and candidate SEASAT orbits were analyzed by Battelle. The additions to the program enable clear understanding of the implications of a specific orbit to the diverse desires of the SEASAT user community.

  4. Five Equivalent d Orbitals

    ERIC Educational Resources Information Center

    Pauling, Linus; McClure, Vance

    1970-01-01

    Amplifies and clarifies a previous paper on pyramidal d orbitals. Discusses two sets of pyramid d orbitals with respect to their maximum bond strength and their symmetry. Authors described the oblate and prolate pentagonal antiprisms arising from the two sets of five equivalent d orbitals. (RR)

  5. Introducing Earth's Orbital Eccentricity

    ERIC Educational Resources Information Center

    Oostra, Benjamin

    2015-01-01

    Most students know that planetary orbits, including Earth's, are elliptical; that is Kepler's first law, and it is found in many science textbooks. But quite a few are mistaken about the details, thinking that the orbit is very eccentric, or that this effect is somehow responsible for the seasons. In fact, the Earth's orbital eccentricity is…

  6. Wall surveyor project report

    SciTech Connect

    Mullenhoff, D.J.; Johnston, B.C.; Azevedo, S.G.

    1996-02-22

    A report is made on the demonstration of a first-generation Wall Surveyor that is capable of surveying the interior and thickness of a stone, brick, or cement wall. LLNL`s Micropower Impulse Radar is used, based on emitting and detecting very low amplitude and short microwave impulses (MIR rangefinder). Six test walls were used. While the demonstrator MIR Wall Surveyor is not fieldable yet, it has successfully scanned the test walls and produced real-time images identifying the walls. It is planned to optimize and package the evaluation wall surveyor into a hand held unit.

  7. Wind tunnel wall interference

    NASA Technical Reports Server (NTRS)

    Newman, Perry A.; Mineck, Raymond E.; Barnwell, Richard W.; Kemp, William B., Jr.

    1986-01-01

    About a decade ago, interest in alleviating wind tunnel wall interference was renewed by advances in computational aerodynamics, concepts of adaptive test section walls, and plans for high Reynolds number transonic test facilities. Selection of NASA Langley cryogenic concept for the National Transonic Facility (NTF) tended to focus the renewed wall interference efforts. A brief overview and current status of some Langley sponsored transonic wind tunnel wall interference research are presented. Included are continuing efforts in basic wall flow studies, wall interference assessment/correction procedures, and adaptive wall technology.

  8. If walls could talk

    NASA Technical Reports Server (NTRS)

    Braam, J.; McIntire, L. V. (Principal Investigator)

    1999-01-01

    The plant cell wall is very complex, both in structure and function. The wall components and the mechanical properties of the wall have been implicated in conveying information that is important for morphogenesis. Proteoglycans, fragments of polysaccharides and the structural integrity of the wall may relay signals that influence cellular differentiation and growth control. Furthering our knowledge of cell wall structure and function is likely to have a profound impact on our understanding of how plant cells communicate with the extracellular environment.

  9. Modeling of Interaction of Hydraulic Fractures in Complex Fracture Networks

    NASA Astrophysics Data System (ADS)

    Kresse, O. 2; Wu, R.; Weng, X.; Gu, H.; Cohen, C.

    2011-12-01

    A recently developed unconventional fracture model (UFM) is able to simulate complex fracture network propagation in a formation with pre-existing natural fractures. Multiple fracture branches can propagate at the same time and intersect/cross each other. Each open fracture exerts additional stresses on the surrounding rock and adjacent fractures, which is often referred to as "stress shadow" effect. The stress shadow can cause significant restriction of fracture width, leading to greater risk of proppant screenout. It can also alter the fracture propagation path and drastically affect fracture network patterns. It is hence critical to properly model the fracture interaction in a complex fracture model. A method for computing the stress shadow in a complex hydraulic fracture network is presented. The method is based on an enhanced 2D Displacement Discontinuity Method (DDM) with correction for finite fracture height. The computed stress field is compared to 3D numerical simulation in a few simple examples and shows the method provides a good approximation for the 3D fracture problem. This stress shadow calculation is incorporated in the UFM. The results for simple cases of two fractures are presented that show the fractures can either attract or expel each other depending on their initial relative positions, and compares favorably with an independent 2D non-planar hydraulic fracture model. Additional examples of both planar and complex fractures propagating from multiple perforation clusters are presented, showing that fracture interaction controls the fracture dimension and propagation pattern. In a formation with no or small stress anisotropy, fracture interaction can lead to dramatic divergence of the fractures as they tend to repel each other. However, when stress anisotropy is large, the fracture propagation direction is dominated by the stress field and fracture turning due to fracture interaction is limited. However, stress shadowing still has a strong effect

  10. Transport of Particle Swarms Through Fractures

    NASA Astrophysics Data System (ADS)

    Boomsma, E.; Pyrak-Nolte, L. J.

    2011-12-01

    The transport of engineered micro- and nano-scale particles through fractured rock is often assumed to occur as dispersions or emulsions. Another potential transport mechanism is the release of particle swarms from natural or industrial processes where small liquid drops, containing thousands to millions of colloidal-size particles, are released over time from seepage or leaks. Swarms have higher velocities than any individual colloid because the interactions among the particles maintain the cohesiveness of the swarm as it falls under gravity. Thus particle swarms give rise to the possibility that engineered particles may be transported farther and faster in fractures than predicted by traditional dispersion models. In this study, the effect of fractures on colloidal swarm cohesiveness and evolution was studied as a swarm falls under gravity and interacts with fracture walls. Transparent acrylic was used to fabricate synthetic fracture samples with either (1) a uniform aperture or (2) a converging aperture followed by a uniform aperture (funnel-shaped). The samples consisted of two blocks that measured 100 x 100 x 50 mm. The separation between these blocks determined the aperture (0.5 mm to 50 mm). During experiments, a fracture was fully submerged in water and swarms were released into it. The swarms consisted of dilute suspensions of either 25 micron soda-lime glass beads (2% by mass) or 3 micron polystyrene fluorescent beads (1% by mass) with an initial volume of 5μL. The swarms were illuminated with a green (525 nm) LED array and imaged optically with a CCD camera. In the uniform aperture fracture, the speed of the swarm prior to bifurcation increased with aperture up to a maximum at a fracture width of approximately 10 mm. For apertures greater than ~15 mm, the velocity was essentially constant with fracture width (but less than at 10 mm). This peak suggests that two competing mechanisms affect swarm velocity in fractures. The wall provides both drag, which

  11. Orbital Evolution of Asteroids

    NASA Astrophysics Data System (ADS)

    Dermott, S. F.; Kehoe, T. J. J.

    2011-10-01

    The synthetic orbital frequencies and eccentricities of main belt asteroids computed by Knezevic and Milani [2] show evidence that the structure of the asteroid belt has been determined by a dense of web of high-order resonances. By examining the orbital frequency distribution at high resolution, we discover a correlation between asteroid number density, mean orbital eccentricity and Lyapunov Characteristic Exponent. In particular, the orbital eccentricities of asteroids trapped in resonance tend to be higher than those of non-resonant asteroids and we argue that this is observational evidence for orbital evolution due to chaotic diffusion.

  12. Orbit Software Suite

    NASA Technical Reports Server (NTRS)

    Osgood, Cathy; Williams, Kevin; Gentry, Philip; Brownfield, Dana; Hallstrom, John; Stuit, Tim

    2012-01-01

    Orbit Software Suite is used to support a variety of NASA/DM (Dependable Multiprocessor) mission planning and analysis activities on the IPS (Intrusion Prevention System) platform. The suite of Orbit software tools (Orbit Design and Orbit Dynamics) resides on IPS/Linux workstations, and is used to perform mission design and analysis tasks corresponding to trajectory/ launch window, rendezvous, and proximity operations flight segments. A list of tools in Orbit Software Suite represents tool versions established during/after the Equipment Rehost-3 Project.

  13. Lunar Reconnaissance Orbiter Orbit Determination Accuracy Analysis

    NASA Technical Reports Server (NTRS)

    Slojkowski, Steven E.

    2014-01-01

    LRO definitive and predictive accuracy requirements were easily met in the nominal mission orbit, using the LP150Q lunar gravity model. center dot Accuracy of the LP150Q model is poorer in the extended mission elliptical orbit. center dot Later lunar gravity models, in particular GSFC-GRAIL-270, improve OD accuracy in the extended mission. center dot Implementation of a constrained plane when the orbit is within 45 degrees of the Earth-Moon line improves cross-track accuracy. center dot Prediction accuracy is still challenged during full-Sun periods due to coarse spacecraft area modeling - Implementation of a multi-plate area model with definitive attitude input can eliminate prediction violations. - The FDF is evaluating using analytic and predicted attitude modeling to improve full-Sun prediction accuracy. center dot Comparison of FDF ephemeris file to high-precision ephemeris files provides gross confirmation that overlap compares properly assess orbit accuracy.

  14. Orbit correction in an orbit separated cyclotron

    NASA Astrophysics Data System (ADS)

    Plostinar, C.; Rees, G. H.

    2014-04-01

    The orbit separated proton cyclotron (OSC) described in [1] differs in concept from that of a separated orbit cyclotron (SOC) [2]. Synchronous acceleration in an OSC is based on harmonic number jumps and orbit length adjustments via reverse bending. Four-turn acceleration in the OSC enables it to have four times fewer cryogenic-cavity systems than in a superconducting linac of the same high beam power and energy range. Initial OSC studies identified a progressive distortion of the spiral beam orbits by the off-axis, transverse deflecting fields in its accelerating cavities. Compensation of the effects of these fields involves the repeated use of a cavity field map, in a 3-D linac tracking code, to determine the modified arc bends required for the OSC ring. Subsequent tracking studies confirm the compensation scheme and show low emittance growth in acceleration.

  15. Fracture corridors in carbonates

    NASA Astrophysics Data System (ADS)

    Chatelée, Sébastien; Lamarche, Juliette; Gauthier, Bertrand D. M.

    2015-04-01

    Among fractures, Fracture Corridors (FC) are anomalous structures made of highly persistent fracture clusters having a strong effect on multi-phase fluid flow in the subsurface. While mechanical and geological conditions for diffuse fracture systems are well constrained, FC genetic conditions remain a matter of questioning. FC can be localized in larger structures such as folds and fault zones but recent studies suggest that a large amount of fractures and FC also arise as distributed in the host rock and formed in tabular layers during burial with early rock mechanical differentiation. In addition, while the mechanical stratigraphy is of prime importance for fracture stratigraphy, it is still unknown which factor prevails on FC genesis among the local versus regional stress-state, the host rock mechanical stratigraphy or the sedimentary facies. We present a study of fractures in a 400×300 m wide quarry (Calvisson, SE France) dug in homogeneous marly limestones of Hauterivian age. The quarry exhibits diffuse fractures as well as 16 FC. The aim of this study is to reveal the genetics factor for FC development, their global geometry and internal morphologic variations, but also to clear the impact of fracture corridors on diffuse fracture. For that, we measured >2500 fractures (strike, dip, spacing, filling, aperture, etc.) and studied microstructures in 80 thin sections. We calculated fracture density and acquired LiDAR data with >90 million points with a resolution of 4 to 15mm. Diffuse fractures are organized as two perpendicular sets, a main set NE-SW-trending and minor set NW-SE-trending. The FC have the same trend, but the NW-SE trend prevail on the NE-SW one. The LiDAR acquisition allows to visualize the 3D lateral continuity with corridors with a minimal extension of 30m. We distinguish 4 internal morphologic types in FC, depending on fracture morphology, occurrence of breccia and number of zones. The types may occur in a single FC with a lateral transition

  16. Fracturing operations in a dry geothermal reservoir

    SciTech Connect

    Rowley, J.C.; Pettitt, R.A.; Hendron, R.H.; Sinclair, A.R.; Nicholson, R.W.

    1983-01-01

    Fracturing operations at the Fenton Hill, New Mexico, Hot Dry Rock (HDR) Geothermal Test Site initiated unique developments necessary to solve problems caused by an extremely harsh downhole environment. Two deep wells were drilled to approximately 15,000 ft (4.6 km); formation temperatures are in excess of 600/sup 0/F (315/sup 0/C). The wells were drilled during 1979 to 1981, inclined at 35 degrees, one above the other, and directionally drilled in an azimuthal direction orthogonal to the least principal in-situ crustal stress field. Hydraulic fracturing experiments to connect the two wells have used openhole packers, hydraulic jet notching of the borehole wall, cemented-in insolation liners and casing packers. Problems were encountered with hole drag, high fracture gradients, H/sub 2/S in vent back fluids, stress corrosion cracking of tubulars, and the complex nature of three-dimensional fracture growth that requires very large volumes of injected water. Two fractured zones have been formed by hydraulic fracturing and defined by close-in, borehole deployed, microseismic detectors. Initial operations were focused in the injection wellbore near total depth, where water injection treatments totalling 51,000 bbls (8100 m/sup 3/) were accomplished by pumping through a cemented-in 4-1/2 in. liner/PBR assembly. Retrievable casing packers were used to inject 26,000 bbls (4100 m/sup 3/) in the upper section of the open hole. Surface injection pressures (ISIP) varied from 4000 to 5900 psi (27 to 41 MPa) and the fracture gradient ranged from 0.7 to 0.96 psi/ft.

  17. Stress fractures in athletes.

    PubMed

    Hulkko, A; Orava, S

    1987-06-01

    During the 14-year period of 1971-1985, 368 stress fractures in 324 athletes were treated. The series contained 268 fractures in males and 100 fractures in females; 32 fractures occurred in children (less than 16 years), 117 in adolescents (16-19 years), and 219 in adults. Forty-six fractures were incurred by athletes at an international level, 274 by athletes at a national or district level and 48 by recreational athletes. Of the total cases, 72% occurred to runners and a further 12% to athletes in other sports after running exercises. The distribution of the stress fractures by site was: tibia 182, metatarsal bones 73, fibula 44, big toe sesamoid bones 15, femoral shaft 14, femoral neck 9, tarsal navicular 9, pelvis 7, olecranon 5 and other bones 10. Of the total fractures, 342 were treated conservatively and 26 fractures required surgical treatment. The operative indication was dislocation in 5 cases and delayed union/nonunion in 21 cases. The sites most often affected by delayed union were: anterior midtibia, sesamoid bones of the big toe, base of the fifth metatarsal, olecranon, and tarsal navicular. The athletes at an international level experienced the greatest risk of multiple separate fractures, protracted healing, or fractures requiring surgery. PMID:3623785

  18. Pyroclastic Deposits in the Floor-fractured Crater Alphonsus

    NASA Technical Reports Server (NTRS)

    Allen, Carlton C.; Donaldson-Hanna, Kerri L.; Pieters, Carle M.; Moriarty, Daniel P.; Greenhagen, Benjamin T.; Bennett, Kristen A.; Kramer, Georgiana Y.; Paige, David A.

    2013-01-01

    Alphonsus, the 118 km diameter floor-fractured crater, is located immediately east of Mare Nubium. Eleven pyroclastic deposits have been identified on the crater's floor. Early telescopic spectra suggest that the floor of Alphonsus is noritic, and that the pyroclastic deposits contain mixtures of floor material and a juvenile component including basaltic glass. Head and Wilson contend that Nubium lavas intruded the breccia zone beneath Alphonsus, forming dikes and fractures on the crater floor. In this model, the magma ascended to the level of the mare but cooled underground, and a portion broke thru to the surface in vulcanian (explosive) eruptions. Alternatively, the erupted material could be from a source unrelated to the mare, in the style of regional pyroclastic deposits. High-resolution images and spectroscopy from the Moon Mineralogy Mapper (M3), Diviner Lunar Radiometer, and Lunar Reconnaissance Orbiter Camera Narrow Angle Camera (NAC) provide data to test these formation models. Spectra from M3 confirm that the crater floor is primarily composed of noritic material, and that the Nubium lavas are basaltic. Spectra from the three largest pyroclastic deposits in Alphonsus are consistent with a minor low- Ca pyroxene component in a glass-rich matrix. The centers of the 2 micron absorption bands have wavelengths too short to be of the same origin as the Nubium basalts. Diviner Christiansen feature (CF) values were used to estimate FeO abundances for the crater floor, Nubium soil, and pyroclastic deposits. The estimated abundance for the crater floor (7.5 +/- 1.4 wt.%) is within the range of FeO values for Apollo norite samples. However, the estimated FeO abundance for Nubium soil (13.4 +/- 1.4 wt.%) is lower than those measured in most mare samples. The difference may reflect contamination of the mare soil by highland ejecta. The Diviner-derived FeO abundance for the western pyroclastic deposit is 13.8 +/- 3.3 wt.%. This is lower than the values for mare soil

  19. Treatment Challenges with Benign Bone Tumors of the Orbit

    PubMed Central

    Merritt, Helen; Yin, Vivian T.; Pfeiffer, Margaret L.; Wang, Wei-Lien; Sniegowski, Matthew C.; Esmaeli, Bita

    2015-01-01

    Benign mesenchymal tumors of the craniofacial complex present unique challenges for orbital surgeons because of their potential for orbital compartment syndrome, ocular morbidity, and facial disfigurement and because definitive surgical management may be associated with significant morbidity. While the precise classification of such lesions depends on radiologic as well as histologic evaluations and remains controversial, benign tumors involving the bony walls of the orbit share features of bony expansion, facial deformity, and the potential to cause significant orbital and ophthalmic morbidity. We herein present 2 cases of benign mesenchymal tumors with bony involvement in the orbitofacial region (1 juvenile ossifying fibroma and 1 central giant cell granuloma) and review the current management of similar benign fibro-osseous and reactive bone lesions of the orbit. These rare entities presented share common orbital and ophthalmic manifestations and remain without any effective definitive treatment options. PMID:27171013

  20. Radiological evaluation of orbital tumours in Ibadan, Nigeria.

    PubMed

    Fafowora, O F; Cookey-gam, A I; Obajimi, M O

    1996-12-01

    Tissue diagnosis of orbital tumours is especially difficult because of the wide range of tissues normally occurring in the orbit [2]. Unfortunately, such tumours are relatively surgically inaccessible for biopsy due to the presence of the bony walls of the orbit and its peculiar shape. This gives rise to a need for effective methods of indirect assessment of the orbit and its contents prior to definitive therapy. Such indirect assessment may be achieved using certain modalities of radiological imaging. These include conventional plain X-ray films, ultrasound scan (USS) and computerized axial tomography (CAT scan), orbital venography and magnetic resonance imaging. This paper is a pilot study of current practices in the use of radiological imaging techniques in the diagnosis of orbital tumours at a University Hospital. PMID:9532308

  1. Solar Sail Optimal Orbit Transfers to Synchronous Orbits

    NASA Technical Reports Server (NTRS)

    Powers, Robert B.; Coverstone, Victoria; Prussing, John E.; Lunney, Bryan C. (Technical Monitor)

    1999-01-01

    A constant outward radial thrust acceleration can be used to reduce the radius of a circular orbit of specified period. Heliocentric circular orbits are designed to match the orbital period of Earth or Mars for various radial thrust accelerations and are defined as synchronous orbits. Minimum-time solar sail orbit transfers to these synchronous heliocentric orbits are presented.

  2. Orbital Thermal Control of the Mercury Capsule

    NASA Technical Reports Server (NTRS)

    Weston, Kenneth C.

    1960-01-01

    The approach to orbital thermal control of the Project Mercury capsule environment is relatively unsophisticated compared with that for many unmanned satellites. This is made possible by the relatively short orbital flight of about 4 1/2 hours and by the presence of the astronaut who is able to monitor the capsule systems and compensate for undesirable thermal conditions. The general external features of the Mercury configuration as it appears in the orbital phase of flight are shown. The conical afterbody is a double-wall structure. The inner wall serves as a pressure vessel for the manned compartment, and the outer wall, of shingle type construction, acts as a radiating shield during reentry. Surface treatment of the shingles calls for a stably oxidized surface to minimize reentry temperatures. The shingles are supported by insulated stringers attached to the inner skin. Areas between stringers are insulated by blankets of Thermoflex insulation. This insulation is especially effective at high altitude due to the reduction of its thermal conductivity with decreasing pressure. As a result of the design of the afterbody for the severe reentry conditions, the heat balance on the manned compartment indicates the necessity for moderate internal cooling to compensate for the heat generation due to human and electrical sources. This cooling is achieved by the controlled vaporization of water in the cabin and astronaut-suit heat exchangers.

  3. Some advances in fracture studies under the heavy-section steel technology program

    SciTech Connect

    Pugh, C.E.; Corwin, W.R.; Bryan, R.H,; Bass, B.R.

    1985-01-01

    Recent results are summarized from HSST studies in three major areas that relate to assessing nuclear reactor pressure vessel integrity under pressurized-thermal-shock (PTS) conditions: irradiation effects on the fracture properties of stainless steel cladding, crack run-arrest behavior under nonisothermal conditions, and fracture behavior of a thick-wall vessel under combined thermal and pressure loadings.

  4. Particle Swarm Transport in Fracture Networks

    NASA Astrophysics Data System (ADS)

    Pyrak-Nolte, L. J.; Mackin, T.; Boomsma, E.

    2012-12-01

    intersections were larger in width than the individual fractures, enabling the swarm to expand freely because of less confinement from the fracture walls. When swarms were released in a fracture network supporting an ambient flow rate, the ability to transport cohesive swarms through the fracture network was a function of the flow rate and swarm volume. For low ambient flow rates (< 4 μl/min), the gravitational force on the swarm dominated, and swarm transport followed a path similar to that for a quiescent fluid. For flow rates > 4 μl/min, large swarms (30 μl) remained cohesive (i.e. low loss of particles) as swarms were driven through the network both in the direction of and opposite to the direction of gravity. These experiments demonstrate conditions under which colloidal-size contaminants can be driven through a fracture network. High-speed transport of cohesive swarms depends on the volume of the swarm and the ambient flow rates that provide a balance of forces that prevents significant loss of particle from the swarm or deposition of particles along the flow path. Swarms that are transported cohesively travel along a highly localized path through a fracture network. Acknowledgment: The authors wish to acknowledge support of this work by the Geosciences Research Program, Office of Basic Energy Sciences US Department of Energy (DE-FG02-09ER16022) and NSF REU program in the Physics Department at Purdue University.

  5. Full orbit calculation for lost alpha particle measurement on ITER

    SciTech Connect

    Funaki, D.; Isobe, M.; Nishiura, M.; Sato, Y.; Okamoto, A.; Kobuchi, T.; Kitajima, S.; Sasao, M.

    2008-10-15

    An orbit following calculation code with full gyromotion under the ITER magnetic field configuration has been developed to investigate escaping alpha particle orbits in ITER and to determine the geometrical arrangement for alpha particle detection. The code contained the full geometrical information of the first wall panels. It was carefully investigated whether an alpha particle escaping from the plasma through the last closed flux surface does not touch or intersect the first wall boundary before reaching the detection point. Candidates of blanket module modification have been studied to achieve effective measurement geometry for escaping alpha particle detection. The calculations showed that direct orbit loss and banana diffusion can be detected with a probe head recessed from the first wall surface.

  6. [Trochanteric femoral fractures].

    PubMed

    Douša, P; Čech, O; Weissinger, M; Džupa, V

    2013-01-01

    At the present time proximal femoral fractures account for 30% of all fractures referred to hospitals for treatment. Our population is ageing, the proportion of patients with post-menopausal or senile osteoporosis is increasing and therefore the number of proximal femoral fractures requiring urgent treatment is growing too. In the age category of 50 years and older, the incidence of these fractures has increased exponentially. Our department serves as a trauma centre for half of Prague and part of the Central Bohemia Region with a population of 1 150 000. Prague in particular has a high number of elderly citizens. Our experience is based on extensive clinical data obtained from the Register of Proximal Femoral Fractures established in 1997. During 14 years, 4280 patients, 3112 women and 1168 men, were admitted to our department for treatment of proximal femoral fractures. All patients were followed up until healing or development of complications. In the group under study, 82% were patients older than 70 years; 72% of those requiring surgery were in their seventies and eighties. Men were significantly younger than women (p<0.001) and represented 30% of the group. The fractures were 2.3-times more frequent in women than in men. In the category under 60 years, men significantly outnumbered women (p<0.001). The patients with pertrochanteric fractures were, on the average, eight years older than the patients with intertrochanteric fractures, which is a significant difference (p<0.001). The mortality rate within a year of injury was about 30%. Trochanteric fractures accounted for 54.7% and femoral neck fractures for 45.3% of all fractures. The inter-annual increase was 5.9%, with more trochanteric than femoral neck fractures. There was a non-significant decrease in intertrochanteric (AO 31-A3) fractures. On the other hand, the number of pertrochanteric (AO 31-A1+2) fractures increased significantly (p<0.001). A total of 1 394 fractures were treated with a proximal

  7. Growth, children, and fractures.

    PubMed

    Jones, Graeme

    2004-09-01

    Fractures in childhood have long been considered an unavoidable consequence of growth. Studies in recent years have documented the epidemiology of these very common fractures and have also documented considerable variation by fracture type and from country to country. There have also been a number of studies aimed at identifying risk factors particularly for the most common distal forearm fracture. These studies have consistently associated bone mineral density with these fractures. Other possible risk factors include obesity, physical inactivity, sports, cola beverages, calcium intake, risk taking, and coordination. While prospective studies are required to confirm these risk factors, accumulating evidence now suggests that a substantial proportion of fractures in children are preventable. PMID:16036086

  8. Fracture tooth fragment reattachment

    PubMed Central

    Maitin, Nitin; Maitin, Shipra Nangalia; Rastogi, Khushboo; Bhushan, Rajarshi

    2013-01-01

    Coronal fractures of the anterior teeth are a common form of dental trauma and its sequelae may impair the establishment and accomplishment of an adequate treatment plan. Among the various treatment options, reattachment of a crown fragment is a conservative treatment that should be considered for crown fractures of anterior teeth. This clinical case reports the management of two coronal tooth fracture cases that were successfully treated using tooth fragment reattachment using glass-fibre-reinforced composite post. PMID:23853012

  9. Ion orbits in plasma etching of semiconductors

    SciTech Connect

    Madziwa-Nussinov, Tsitsi G.; Arnush, Donald; Chen, Francis F.

    2008-01-15

    Fabrication of high-speed semiconductor circuits depends on etching submicron trenches and holes with straight walls, guided by sheath accelerated ions, which strike the substrate at a normal angle. Electrons accumulate at the nonconductive entrance of each trench, charging it negatively and preventing the penetration of electrons to the bottom of the trench. This 'electron shading' effect causes an ion charge at the bottom, which is well known to cause damage to thin oxide layers. In addition, the deflection of ions by electric fields in the trench can cause deformation of the trench shape. To study this effect, the ion orbits are computed self-consistently with their charging of the trench walls. It is found that (a) the orbits depend only on the electric fields at the entrance and are sensitive to changes in the shape of the photoresist layer there; (b) there is an 'ion shading' effect that protects part of the wall; and (c) the number of ions striking the wall is too small to cause any deformation thereof.

  10. Fluidized wall for protecting fusion chamber walls

    SciTech Connect

    Maniscalco, J.A.; Meier, W.R.

    1982-08-17

    Apparatus for protecting the inner wall of a fusion chamber from microexplosion debris, x-rays, neutrons, etc. Produced by deuterium-tritium (DT) targets imploded within the fusion chamber. The apparatus utilizes a fluidized wall similar to a waterfall comprising liquid lithium or solid pellets of lithiumceramic, the waterfall forming a blanket to prevent damage of the structural materials of the chamber.

  11. The Orbital Workshop Shower Compartment

    NASA Technical Reports Server (NTRS)

    1972-01-01

    This photograph shows technicians performing a checkout of the Metabolic Analyzer (center background) and the Ergometer (foreground) in the Orbital Workshop (OWS). The shower compartment is at right. The Ergometer (Skylab Experiment M171) evaluated man's metabolic effectiveness and cost of work in space environment. Located in the experiment and work area of the OWS, the shower compartment was a cylindrical cloth enclosure that was folded flat when not in use. The bottom ring of the shower was fastened to the floor and contained foot restraints. The upper ring contained the shower head and hose. To use the shower, the astronaut filled a pressurized portable bottle with heated water and attached the bottle to the ceiling. A flexible hose cornected the water bottle to a handheld shower head. The astronaut pulled the cylindrical shower wall up into position and bathed, using liquid soap. Both soap and water were carefully rationed, having been premeasured for economical use.

  12. The Orbital Workshop Shower Compartment

    NASA Technical Reports Server (NTRS)

    1972-01-01

    In this photograph, the Orbital Workshop shower compartment was unfolded by technicians for inspection. The shower compartment was a cylindrical cloth enclosure that was folded flat when not in use. The bottom ring of the shower was fastened to the floor and contained foot restraints. The upper ring contained the shower head and hose. To use the shower, the astronaut filled a pressurized portable bottle with heated water and attached the bottle to the ceiling. A flexible hose cornected the water bottle to a handheld shower head. The astronaut pulled the cylindrical shower wall up into position and bathed, using liquid soap. Both soap and water were carefully rationed, having been premeasured for economical use.

  13. Pathological fractures in children

    PubMed Central

    De Mattos, C. B. R.; Binitie, O.; Dormans, J. P.

    2012-01-01

    Pathological fractures in children can occur as a result of a variety of conditions, ranging from metabolic diseases and infection to tumours. Fractures through benign and malignant bone tumours should be recognised and managed appropriately by the treating orthopaedic surgeon. The most common benign bone tumours that cause pathological fractures in children are unicameral bone cysts, aneurysmal bone cysts, non-ossifying fibromas and fibrous dysplasia. Although pathological fractures through a primary bone malignancy are rare, these should be recognised quickly in order to achieve better outcomes. A thorough history, physical examination and review of plain radiographs are crucial to determine the cause and guide treatment. In most benign cases the fracture will heal and the lesion can be addressed at the time of the fracture, or after the fracture is healed. A step-wise and multidisciplinary approach is necessary in caring for paediatric patients with malignancies. Pathological fractures do not have to be treated by amputation; these fractures can heal and limb salvage can be performed when indicated. PMID:23610658

  14. Capitellar and Trochlear Fractures.

    PubMed

    Carroll, Michael J; Athwal, George S; King, Graham J W; Faber, Kenneth J

    2015-11-01

    Fractures of the capitellum and trochlea account for a small proportion of elbow trauma. Clinicians need to be vigilant in their assessment as they are commonly associated with other injuries about the elbow. To optimize outcomes, the goals of management include a stable, anatomic reduction and early range of motion. Closed reduction of noncomminuted fractures may be successful but requires close follow-up. Open reduction and internal fixation is the preferred management of displaced capitellum-trochlear fractures. Elbow stiffness is the most commonly reported complication in operatively treated fractures. Arthroscopic-assisted reduction and internal fixation and arthroplasty are evolving management options. PMID:26498550

  15. Pterygoid Plate Fractures: Not Limited to Le Fort Fractures.

    PubMed

    Garg, Ravi K; Alsheik, Nila H; Afifi, Ahmed M; Gentry, Lindell R

    2015-09-01

    Pterygoid plate fractures are often described in the setting of Le Fort fractures. The goal of this study was to define other craniofacial fracture patterns causing injury to the pterygoid plates. A retrospective review of computed tomography (CT) scans obtained on craniofacial trauma patients over a 5-year period revealed 209 patients with pterygoid plate fractures. Pterygoid plate fractures in 78 patients (37.3%) were unrelated to Le Fort fractures. Common causes included sphenotemporal buttress fractures in 26 patients (33.3%), temporal bone fractures in 18 patients (23.1%), zygomaticomaxillary complex fractures in 17 patients (21.8%), and displaced mandible fractures in 14 patients (17.9%). These findings indicate that approximately one third of pterygoid plate fractures do not result from Le Fort pattern injuries and that the craniofacial surgeon should have a broad differential for causes of pterygoid plate fractures when reviewing trauma imaging. PMID:26147022

  16. Micromagnetic analysis of current-induced domain wall motion in a bilayer nanowire with synthetic antiferromagnetic coupling

    NASA Astrophysics Data System (ADS)

    Komine, Takashi; Aono, Tomosuke

    2016-05-01

    We demonstrate current-induced domain wall motion in bilayer nanowire with synthetic antiferromagnetic (SAF) coupling by modeling two body problems for motion equations of domain wall. The influence of interlayer exchange coupling and magnetostatic interactions on current-induced domain wall motion in SAF nanowires was also investigated. By assuming the rigid wall model for translational motion, the interlayer exchange coupling and the magnetostatic interaction between walls and domains in SAF nanowires enhances domain wall speed without any spin-orbit-torque. The enhancement of domain wall speed was discussed by energy distribution as a function of wall angle configuration in bilayer nanowires.

  17. Orbit Determination of the Lunar Reconnaissance Orbiter

    NASA Technical Reports Server (NTRS)

    Mazarico, Erwan; Rowlands, D. D.; Neumann, G. A.; Smith, D. E.; Torrence, M. H.; Lemoine, F. G.; Zuber, M. T.

    2011-01-01

    We present the results on precision orbit determination from the radio science investigation of the Lunar Reconnaissance Orbiter (LRO) spacecraft. We describe the data, modeling and methods used to achieve position knowledge several times better than the required 50-100m (in total position), over the period from 13 July 2009 to 31 January 2011. In addition to the near-continuous radiometric tracking data, we include altimetric data from the Lunar Orbiter Laser Altimeter (LOLA) in the form of crossover measurements, and show that they strongly improve the accuracy of the orbit reconstruction (total position overlap differences decrease from approx.70m to approx.23 m). To refine the spacecraft trajectory further, we develop a lunar gravity field by combining the newly acquired LRO data with the historical data. The reprocessing of the spacecraft trajectory with that model shows significantly increased accuracy (approx.20m with only the radiometric data, and approx.14m with the addition of the altimetric crossovers). LOLA topographic maps and calibration data from the Lunar Reconnaissance Orbiter Camera were used to supplement the results of the overlap analysis and demonstrate the trajectory accuracy.

  18. Satellite orbit determination

    NASA Technical Reports Server (NTRS)

    Jordan, J. F.; Boggs, D. H.; Born, G. H.; Christensen, E. J.; Ferrari, A. J.; Green, D. W.; Hylkema, R. K.; Mohan, S. N.; Reinbold, S. J.; Sievers, G. L.

    1973-01-01

    A historic account of the activities of the Satellite OD Group during the MM'71 mission is given along with an assessment of the accuracy of the determined orbit of the Mariner 9 spacecraft. Preflight study results are reviewed, and the major error sources described. Tracking and data fitting strategy actually used in the real time operations is itemized, and Deep Space Network data available for orbit fitting during the mission and the auxiliary information used by the navigation team are described. A detailed orbit fitting history of the first four revolutions of the satellite orbit of Mariner 9 is presented, with emphasis on the convergence problems and the delivered solution for the first orbit trim maneuver. Also included are a solution accuracy summary, the history of the spacecraft orbit osculating elements, the results of verifying the radio solutions with TV imaging data, and a summary of the normal points generated for the relativity experiment.

  19. Marned Orbital Systems Concept

    NASA Technical Reports Server (NTRS)

    1975-01-01

    Despite the indefinite postponement of the Space Station in 1972, Marshall Space Flight Center (MSFC) continued to look to the future for some type of orbital facility during the post-Skylab years. In 1975, the MSFC directed a contract with the McDonnel Douglas Aerospace Company for the Manned Orbital Systems Concept (MOSC) study. This 9-month effort examined the requirements for, and defined a cost-effective orbital facility concept capable of, supporting extended manned missions in Earth orbit. The capabilities of this concept exceeded those envisioned for the Space Shuttle and Spacelab, both of which were limited by a 7 to 30-day orbital time constraint. The MOSC's initial operating capability was to be achieved in late 1984. A crew of four would man a four-module configuration. During its five-year orbital life the MOSC would have the capability to evolve into a larger 12-to-24-man facility. This is an artist's concept of MOSC.

  20. Sphenoid Sinus and Sphenoid Bone Fractures in Patients with Craniomaxillofacial Trauma

    PubMed Central

    Cantini Ardila, Jorge Ernesto; Mendoza, Miguel Ángel Rivera; Ortega, Viviana Gómez

    2013-01-01

    Background and Purpose Sphenoid bone fractures and sphenoid sinus fractures have a high morbidity due to its association with high-energy trauma. The purpose of this study is to describe individuals with traumatic injuries from different mechanisms and attempt to determine if there is any relationship between various isolated or combined fractures of facial skeleton and sphenoid bone and sphenoid sinus fractures. Methods We retrospectively studied hospital charts of all patients who reported to the trauma center at Hospital de San José with facial fractures from December 2009 to August 2011. All patients were evaluated by computed tomography scan and classified into low-, medium-, and high-energy trauma fractures, according to the classification described by Manson. Design This is a retrospective descriptive study. Results The study data were collected as part of retrospective analysis. A total of 250 patients reported to the trauma center of the study hospital with facial trauma. Thirty-eight patients were excluded. A total of 212 patients had facial fractures; 33 had a combination of sphenoid sinus and sphenoid bone fractures, and facial fractures were identified within this group (15.5%). Gender predilection was seen to favor males (77.3%) more than females (22.7%). The mean age of the patients was 37 years. Orbital fractures (78.8%) and maxillary fractures (57.5%) were found more commonly associated with sphenoid sinus and sphenoid bone fractures. Conclusions High-energy trauma is more frequently associated with sphenoid fractures when compared with medium- and low-energy trauma. There is a correlation between facial fractures and sphenoid sinus and sphenoid bone fractures. A more exhaustive multicentric case-control study with a larger sample and additional parameters will be essential to reach definite conclusions regarding the spectrum of fractures of the sphenoid bone associated with facial fractures. PMID:24436756

  1. Method and apparatus for detecting and evaluating borehole wall fractures

    SciTech Connect

    Danbury, K.H.; Brie, A.; Plumb, R.A.

    1989-09-26

    This patent describes a method for forming a display log of an acoustic investigation of an earth formation penetrated by a borehole with a tool which generates sonic pulses and produces different receiver waveforms respectively representative of sonic waves passed through a common interval alongside the tool. It comprises: measuring from the different waveforms values of a parameter that is representative of a characteristic of the earths formation; assigning predetermined lateral display log position for the parameter values measured from waveforms attributable to a common interval; and recording the parameter values on the display log.

  2. Family of Orbiters

    NASA Technical Reports Server (NTRS)

    2008-01-01

    This image shows the paths of three spacecraft currently in orbit around Mars, as well as the path by which NASA's Phoenix Mars Lander will approach and land on the planet. The t-shaped crosses show where the orbiters will be when Phoenix enters the atmosphere, while the x-shaped crosses show their location at landing time.

    All three orbiters, NASA's Mars Reconnaissance Orbiter, NASA's Mars Odyssey and the European Space Agency's Mars Express, will be monitoring Phoenix during the final steps of its journey to the Red Planet.

    Phoenix will land just south of Mars's north polar ice cap.

  3. Introducing Earth's Orbital Eccentricity

    NASA Astrophysics Data System (ADS)

    Oostra, Benjamin

    2015-12-01

    Most students know that planetary orbits, including Earth's, are elliptical; that is Kepler's first law, and it is found in many science textbooks. But quite a few are mistaken about the details, thinking that the orbit is very eccentric, or that this effect is somehow responsible for the seasons. In fact, the Earth's orbital eccentricity is small, and its only effect on the seasons is their unequal durations. Here I show a pleasant way to guide students to the actual value of Earth's orbital eccentricity, starting from the durations of the four seasons. The date of perihelion is also found.

  4. Orbital physics in RIXS

    NASA Astrophysics Data System (ADS)

    Wohlfeld, Krzysztof; Marra, Pasquale; Grueninger, Markus; Schmitt, Thorsten; van den Brink, Jeroen

    2013-03-01

    In contrast to magnetism, phenomena associated with the orbital degrees of freedom in transition metal oxides had always been considered to be very difficult to observe. However, recently resonant inelastic x-ray scattering (RIXS) has established itself as a perfect probe of the orbital excitations and orbital order in transition metal oxides. Here we give a brief overview of these recent theoretical and experimental advances which have inter alia led to the observation of the separation of the spin and orbital degree of freedom of an electron.

  5. Orbital Debris: A Chronology

    NASA Technical Reports Server (NTRS)

    Portree, Davis S. F. (Editor); Loftus, Joseph P., Jr. (Editor)

    1999-01-01

    This chronology covers the 37-year history of orbital debris concerns. It tracks orbital debris hazard creation, research, observation, experimentation, management, mitigation, protection, and policy. Included are debris-producing, events; U.N. orbital debris treaties, Space Shuttle and space station orbital debris issues; ASAT tests; milestones in theory and modeling; uncontrolled reentries; detection system development; shielding development; geosynchronous debris issues, including reboost policies: returned surfaces studies, seminar papers reports, conferences, and studies; the increasing effect of space activities on astronomy; and growing international awareness of the near-Earth environment.

  6. Magnetospheric Multiscale (MMS) Orbit

    NASA Video Gallery

    This animation shows the orbits of Magnetospheric Multiscale (MMS) mission, a Solar-Terrestrial Probe mission comprising of four identically instrumented spacecraft that will study the Earth's magn...

  7. Role of tooth elongation in promoting fracture resistance.

    PubMed

    Barani, Amir; Keown, Amanda J; Bush, Mark B; Lee, James J-W; Lawn, Brian R

    2012-04-01

    A study is made of the role of tooth height on the resistance to side-wall longitudinal fracture under axial occlusal loading, building on earlier analyses for molar teeth with low dome-like ('bunodont') crown structures characteristic of primates and several other omnivorous mammals. The present study extends the analysis by considering molar teeth with an elongate columnar structure below the crown, more characteristic of grazing mammals. Extended finite element modeling is used to determine the evolution of longitudinal cracking, from initial growth to final failure. Experimental tests on sheep teeth confirm the predicted behavior of the longitudinal fracture mode, at least in its early stages. It is demonstrated that elongate tooth structures have a substantially increased resistance to longitudinal fracture, by restricting crack growth along the extended side walls. Biological implications concerning the adaptation of tooth structure to meet changes in the dietary habits of herbivores, and of some carnivores, are considered. PMID:22402152

  8. Investigating flow properties of partially cemented fractures in Travis Peak Formation using image-based pore-scale modeling

    NASA Astrophysics Data System (ADS)

    Tokan-Lawal, Adenike; Prodanović, Maša.; Eichhubl, Peter

    2015-08-01

    Natural fractures can provide preferred flow pathways in otherwise low-permeability reservoirs. In deep subsurface reservoirs including tight oil and gas reservoirs, as well as in hydrothermal systems, fractures are frequently lined or completely filled with mineral cement that reduces or occludes fracture porosity and permeability. Fracture cement linings potentially reduce flow connectivity between the fracture and host rock and increase fracture wall roughness, which constricts flow. We combined image-based fracture space characterization, mercury injection capillary pressure and permeability experiments, and numerical simulations to evaluate the influence of fracture-lining cement on single-phase and multiphase flows along a natural fracture from the Travis Peak Formation, a tight gas reservoir sandstone in East Texas. Using X-ray computed microtomographic image analysis, we characterized fracture geometry and the connectivity and geometric tortuosity of the fracture pore space. Combining level set method-based progressive quasistatic and lattice Boltzmann simulations, we assessed the capillary-dominated displacement properties and the (relative) permeability of a cement-lined fracture. Published empirical correlations between aperture and permeability for barren fractures provide permeability estimates that vary among each other, and differ from our results, vary by several orders of magnitude. Compared to barren fractures, cement increases the geometric tortuosity, aperture variation of the pore space, and capillary pressure while reducing the single-phase permeability by up to 2 orders of magnitude. For multiphase displacement, relative permeability and fluid entrapment geometry resemble those of porous media and differ from those characteristic of barren fractures.

  9. Fault and Fracture Networks in the Otway Basin, Victoria, Australia; Implications for Structural Permeability

    NASA Astrophysics Data System (ADS)

    Sage, J.; King, R.; Holford, S. P.; Bailey, A. H.; Hand, M. P.

    2013-12-01

    The propensity for a fracture to be open to fluid flow is controlled by the orientation and magnitude of the in-situ stress field, types of cement within fractures, the rock strength of both fracture fills and wall rock and surrounding pore-fluid pressures in both fracture zone and surrounding rock. Although it is well understood that the optimal angle between σ1 and the fracture plane for slip is ~30 degrees, the cumulative effects of all these factors are poorly constrained within sedimentary basins; and therefore, the ability for fluid to flow through fractures is not well known. Naturally occurring fractures were recorded in the field, from outcrop of the Eumeralla Formation in the Otway Basin, Victoria, Australia. Over 1800 fractures were recorded showing a mean strike of NNE-SSW. Two distinctive fracture sets were identified with orientations of ~010-190 and ~045-225. Natural fractures were further characterised as open or closed. A total of 632 open fractures in two dominant sets were observed at surface, with mean strikes of N-S and ESE-WNW. A total of 878 closed fractures (generally being cemented) in two dominant sets were also observed at surface, also with mean strikes of N-S and ESE-WNW. Further investigation of these data showed that despite a majority of these closed fractures being optimally aligned with the present-day stress field, they remained closed. Thin sections revealed multiple generations of fracture cements. Inferring both a crack seal history and that these mineral cements could potentially be rendering the fractures stress insensitive. Failure of fractures to reactivate and remain open to fluid flow in the favourable stress conditions of the Otway Basin has potential to adversely affect and limit the secondary permeability of the system. This also validates the notion that the in-situ stress regime is not always the dominant factor in the propensity for a fracture to be open to fluid flow.

  10. Frequency-Dependent Seismic Waves in Fluid-Saturated Fractured Rock

    NASA Astrophysics Data System (ADS)

    Korneev, V. A.; Goloshubin, G.

    2015-12-01

    Fractures are the natural and essential elements of rock. Fracture systems are the most important features that define rock permeability and strength, as well as their anisotropy properties. Recent advancement in induced fracturing is a core part of the gas/oil shale technology, where fracture monitoring and control became a special topic of interest. Krauklis wave (K-wave) is the result of interaction between a fluid mass and elasticity of fracture walls, and it propagates primarily along the fracture systems in the fluid. At the fracture tips and fracture intersections it partially converts into the body waves. It is quite clear that incorporation of K-waves in a theory of wave propagation in fractured rock is one of the most important problems to solve for understanding of their seismic properties. One of the most fundamental properties of fractured rock is a fractal fracture distribution and it is rarely, if ever, taken into account in existing wave propagation theories. However, this property exists on a widest variety of scales and in particular reveals itself in a form of Gutenberg-Richter Law experimentally proven, starting from laboratory measurements and up to the global seismicity. We computed P and S-wave velocities of the rock containing fluid (and proppant) filled fractures, considering the effect of extremely slow and dispersive wave propagation within individual fractures. This was made possible by introducing the concept of "effective fracture-wave volume," and by evaluating the elastic constants of rock containing a complex, fractal network of fractures. These velocities were used to compute seismic waves reflected normally from a fractured reservoir. We demonstrate that by taking into account the Krauklis wave phenomenon for the fractally distributed fluid-filled fractures, it is possible to explain the observed low-frequency anomalies above the underground natural reservoirs. These anomalies include increase of amplitude and a phase delay of

  11. Halogenation of microcapsule walls

    NASA Technical Reports Server (NTRS)

    Davis, T. R.; Schaab, C. K.; Scott, J. C.

    1972-01-01

    Procedure for halogenation of confining walls of both gelatin and gelatin-phenolic resin capsules is similar to that used for microencapsulation. Ten percent halogen content renders capsule wall nonburning; any higher content enhances flame-retardant properties of selected internal phase material. Halogenation decreases permeability of wall material to encapsulated materials.

  12. The Lamportian cell wall

    SciTech Connect

    Keiliszewski, M.; Lamport, D. )

    1991-05-01

    The Lamportian Warp-Weft hypothesis suggests a cellulose-extensin interpenetrating network where extensin mechanically couples the load-bearing cellulose microfibrils in a wall matrix that is best described as a microcomposite. This model is based on data gathered from the extensin-rich walls of tomato and sycamore cell suspension culture, wherein extensin precursors are insolubilized into the wall by undefined crosslinks. The authors recent work with cell walls isolated from intact tissue as well as walls from suspension cultured cells of the graminaceous monocots maize and rice, the non-graminaceous monocot asparagus, the primitive herbaceous dicot sugar beet, and the gymnosperm Douglas Fir indicate that although extensins are ubiquitous to all plant species examined, they are not the major structural protein component of most walls examined. Amino acid analyses of intact and HF-treated walls shows a major component neither an HRGP, nor directly comparable to the glycine-rich wall proteins such as those associated with seed coat walls or the 67 mole% glycine-rich proteins cloned from petunia and soybean. Clearly, structural wall protein alternatives to extensin exist and any cell wall model must take that into account. If we assume that extracellular matrices are a priori network structures, then new Hypless' structural proteins in the maize cell wall raise questions about the sort of network these proteins create: the kinds of crosslinks involved; how they are formed; and the roles played by the small amounts of HRGPs.

  13. TIBIAL SHAFT FRACTURES

    PubMed Central

    Kojima, Kodi Edson; Ferreira, Ramon Venzon

    2015-01-01

    The long-bone fractures occur most frequently in the tibial shaft. Adequate treatment of such fractures avoids consolidation failure, skewed consolidation and reoperation. To classify these fractures, the AO/OTA classification method is still used, but it is worthwhile getting to know the Ellis classification method, which also includes assessment of soft-tissue injuries. There is often an association with compartmental syndrome, and early diagnosis can be achieved through evaluating clinical parameters and constant clinical monitoring. Once the diagnosis has been made, fasciotomy should be performed. It is always difficult to assess consolidation, but the RUST method may help in this. Radiography is assessed in two projections, and points are scored for the presence of the fracture line and a visible bone callus. Today, the dogma of six hours for cleaning the exposed fracture is under discussion. It is considered that an early start to intravenous antibiotic therapy and the lesion severity are very important. The question of early or late closure of the lesion in an exposed fracture has gone through several phases: sometimes early closure has been indicated and sometimes late closure. Currently, whenever possible, early closure of the lesion is recommended, since this diminishes the risk of infection. Milling of the canal when the intramedullary nail is introduced is still a controversial subject. Despite strong personal positions in favor of milling, studies have shown that there may be some advantage in relation to closed fractures, but not in exposed fractures. PMID:27026999

  14. Rib fracture - aftercare

    MedlinePlus

    A rib fracture is a crack or break in one or more of your rib bones. Your ribs are the round, flat bones in your chest ... A rib fracture can be very painful because your ribs move when you breathe, cough, and move your upper ...

  15. Radionuclide transport in fractured granite interface zones

    NASA Astrophysics Data System (ADS)

    Hu, Q. H.; Möri, A.

    In situ radionuclide migration experiments, followed by excavation and sample characterization, were conducted in a water-conducting shear zone at the Grimsel Test Site (GTS) in Switzerland to study migration paths of radionuclides in fractured granite. In this work, a micro-scale mapping technique was applied by interfacing laser ablation sampling with inductively coupled plasma-mass spectrometry (LA-ICP-MS) to detect the small scale (micron-range) distribution of actinides in the interface zones between fractures and the granitic rock matrix. Long-lived 234U, 235U, and 237Np were detected in flow channels, as well as in the diffusion accessible rock matrix, using the sensitive, feature-based mapping of the LA-ICP-MS technique. The retarded actinides are mainly located at the fracture walls and in the fine grained fracture filling material as well as within the immediately adjacent wallrock. The water-conducting fracture studied in this work is bounded on one side by mylonite and the other by granitic matrix regions. Actinides studied in this work did not penetrate into the mylonite side as much as into the granite matrix, most likely due to the lower porosity, the enhanced sorption capacity and the disturbed diffusion paths of the mylonite region itself. Overall, the maximum penetration depth detected with this technique for 237Np and uranium isotopes over the field experimental time scale of about 60 days was about 10 mm in the granitic matrix, illustrating the importance of matrix diffusion in retarding radionuclide transport from the advective fractures. Laboratory tests and numerical modelling of radionuclide diffusion into granitic matrix was conducted to complement and help interpret the field results.

  16. Dynamic fracture mechanics

    NASA Technical Reports Server (NTRS)

    Kobayashi, A. S.; Ramulu, M.

    1985-01-01

    Dynamic fracture and crack propagation concepts for ductile materials are reviewed. The equations for calculating dynamic stress integrity and the dynamic energy release rate in order to study dynamic crack propagation are provided. The stress intensity factor versus crack velocity relation is investigated. The uses of optical experimental techniques and finite element methods for fracture analyses are described. The fracture criteria for a rapidly propagating crack under mixed mode conditions are discussed; crack extension and fracture criteria under combined tension and shear loading are based on maximum circumferential stress or energy criteria such as strain energy density. The development and use of a Dugdale model and finite element models to represent crack and fracture dynamics are examined.

  17. Transphyseal Distal Humerus Fracture.

    PubMed

    Abzug, Joshua; Ho, Christine Ann; Ritzman, Todd F; Brighton, Brian

    2016-01-01

    Transphyseal distal humerus fractures typically occur in children younger than 3 years secondary to birth trauma, nonaccidental trauma, or a fall from a small height. Prompt and accurate diagnosis of a transphyseal distal humerus fracture is crucial for a successful outcome. Recognizing that the forearm is not aligned with the humerus on plain radiographs may aid in the diagnosis of a transphyseal distal humerus fracture. Surgical management is most commonly performed with the aid of an arthrogram. Closed reduction and percutaneous pinning techniques similar to those used for supracondylar humerus fractures are employed. Cubitus varus caused by a malunion, osteonecrosis of the medial condyle, or growth arrest is the most common complication encountered in the treatment of transphyseal distal humerus fractures. A corrective lateral closing wedge osteotomy can be performed to restore a nearly normal carrying angle. PMID:27049206

  18. Apparent capitellar fractures.

    PubMed

    Ring, David

    2007-11-01

    Isolated capitellar fractures are rare but are identified as such, even when they are more complex, because the displaced capitellar fracture is usually the most obvious and identifiable radiographic finding and because teaching has traditionally underemphasized the involvement of the trochlea in such fractures. The author prefers the term 'apparent capitellar fractures' and draws on his experience to explain why he favors three-dimensional CT for depicting fracture detail. This article discusses treatment options, emphasizing open reduction and internal fixation to restore the native elbow. Operative techniques, including extensile lateral exposure and olecranon osteotomy; fixation techniques; and elbow arthroplasty, are described. Complications, such as ulnar neuropathy and infection, are also covered. PMID:18054674

  19. Analysis of fracture patterns and local stress field variations in fractured reservoirs

    NASA Astrophysics Data System (ADS)

    Deckert, Hagen; Drews, Michael; Fremgen, Dominik; Wellmann, J. Florian

    2010-05-01

    A meaningful qualitative evaluation of permeabilities in fractured reservoirs in geothermal or hydrocarbon industry requires the spatial description of the existing discontinuity pattern within the area of interest and an analysis how these fractures might behave under given stress fields. This combined information can then be used for better estimating preferred fluid pathway directions within the reservoir, which is of particular interest for defining potential drilling sites. A description of the spatial fracture pattern mainly includes the orientation of rock discontinuities, spacing relationships between single fractures and their lateral extent. We have examined and quantified fracture patterns in several outcrops of granite at the Costa Brava, Spain, and in the Black Forest, Germany, for describing reservoir characteristics. For our analysis of fracture patterns we have used photogrammetric methods to create high-resolution georeferenced digital 3D images of outcrop walls. The advantage of this approach, compared to conventional methods for fracture analysis, is that it provides a better 3D description of the fracture geometry as the entity of position, extent and orientation of single fractures with respect to their surrounding neighbors is conserved. Hence for instance, the method allows generating fracture density maps, which can be used for a better description of the spatial distribution of discontinuities in a given outcrop. Using photogrammetric techniques also has the advantage to acquire very large data sets providing statistically sound results. To assess whether the recorded discontinuities might act as fluid pathways information on the stress field is needed. A 3D model of the regional tectonic structure was created and the geometry of the faults was put into a mechanical 3D Boundary Element (BE) Model. The model takes into account the elastic material properties of the geological units and the orientation of single fault segments. The

  20. Fracture Characteristics in a Disposal Pit on Mesita del Buey, Los Alamos National Laboratory

    SciTech Connect

    David T. Vaniman; Steven L. Reneau

    1998-12-01

    The characteristics of fractures in unit 2 of the Tshirege Member of the Bandelier Tuff were documented in Pit 39, a newly excavated 13.7 m deep disposal pit at Material Disposal Area G on Mesita del Buey. The average spacing between fractures is about 1.0 to 1.3 m, the average fracture aperture is about 3 to 5 mm, and the average fracture dip is about 76o to 77o. Fracture spacing and dip in Pit 39 are generally consistent with that reported from other fracture studies on the Pajarito Plateau, although the fracture apertures in Pit 39 are less than reported elsewhere. Measured fracture orientations are strongly affected by biases imparted by the orientations of the pit walls, which, combined with a small data set, make identification of potential preferred orientations dlfflcult. The most prominent fracture orientations observed in Pit 39, about E-W and N20E, are often not well represented elsewhere on the Pajarito Plateau. Fracture fills contain smectite to about 3 m depth, and calcite and opal may occur at all depths, principally associated with roots or root fossils (rhizoliths). Roots of pifion pine extend in fractures to the bottom of the pit along the north side, perhaps indicating a zone of preferred infiltration of water. Finely powdered tuff with clay-sized particles occurs within a number of fractures and may record abrasive disaggregation associated with small amounts of displacement on minor local faults.

  1. The white-eyed blowout fracture in the child: beware of distractions.

    PubMed

    Hammond, D; Grew, N; Khan, Z

    2013-01-01

    Inferior 'trapdoor' orbital floor fractures with muscle and soft tissue incarceration are the most common type of orbital fracture in children. Delays to treatment can lead to a significant morbidity. It has been recommended that children who present with a 'white-eyed blowout' fracture should have surgery performed within 48h of diagnosis, otherwise prognosis is poor. A 14-year-old boy was initially misdiagnosed with a head injury due to the minor appearance of his orbital injury and his presenting complaint of nausea and vomiting. This resulted in a significant delay to surgery. The oculovagal reflex associated with orbital injuries is well documented (Wei and Durairaj in Pediatric orbital floor fractures. J AAPOS 2011;15: :173-80). It should be considered by emergency department and paediatric staff when dealing with patients who have sustained a blow to the orbital region, despite not having a subconjunctival haemorrhage. The importance of examination to detect other features of orbital blow-out and entrapment are stressed. PMID:24964459

  2. Titan Orbiter Aerorover Mission

    NASA Technical Reports Server (NTRS)

    Sittler Jr., E. C.; Acuna, M.; Burchell, M. J.; Coates, A.; Farrell, W.; Flasar, M.; Goldstein, B. E.; Gorevan, S.; Hartle, R. E.; Johnson, W. T. K.

    2001-01-01

    We propose a combined Titan orbiter and Titan Aerorover mission with an emphasis on both in situ and remote sensing measurements of Titan's surface, atmosphere, ionosphere, and magnetospheric interaction. The biological aspect of the Titan environment will be emphasized by the mission (i.e., search for organic materials which may include simple organics to 'amono' analogues of amino acids and possibly more complex, lightening detection and infrared, ultraviolet, and charged particle interactions with Titan's surface and atmosphere). An international mission is assumed to control costs. NASA will provide the orbiter, launch vehicle, DSN coverage and operations, while international partners will provide the Aerorover and up to 30% of the cost for the scientific instruments through collaborative efforts. To further reduce costs we propose a single PI for orbiter science instruments and a single PI for Aerorover science instruments. This approach will provide single command/data and power interface between spacecraft and orbiter instruments that will have redundant central DPU and power converter for their instruments. A similar approach could be used for the Aerorover. The mission profile will be constructed to minimize conflicts between Aerorover science, orbiter radar science, orbiter radio science, orbiter imaging science, and orbiter fields and particles (FP) science. Additional information is contained in the original extended abstract.

  3. Fluidized wall for protecting fusion chamber walls

    SciTech Connect

    Maniscalco, James A.; Meier, Wayne R.

    1982-01-01

    Apparatus for protecting the inner wall of a fusion chamber from microexplosion debris, x-rays, neutrons, etc. produced by deuterium-tritium (DT) targets imploded within the fusion chamber. The apparatus utilizes a fluidized wall similar to a waterfall comprising liquid lithium or solid pellets of lithium-ceramic, the waterfall forming a blanket to prevent damage of the structural materials of the chamber.

  4. Magnetization dynamics driven by angle-dependent spin-orbit spin-transfer torque

    NASA Astrophysics Data System (ADS)

    Lee, Seo-Won; Lee, Kyung-Jin

    2015-11-01

    Spin-orbit torque allows efficient control of the magnetization by using the in-plane current. Recent experiments found a strong angular dependence of spin-orbit torque. We theoretically investigate magnetization switching and domain wall motion induced by an angle-dependent spinorbit torque in perpendicularly magnetized layers. We obtain analytic expressions for the switching current and the domain wall velocity, which are in agreement with numerical results. Based on the expressions, we find that a spin-orbit torque that increases with increasing polar angle of the magnetization is beneficial for both switching and domain wall motion. Our result will serve as a guideline to design and interpret switching and domain wall experiments based on the spin-orbit torque.

  5. Orbital Debris Mitigation

    NASA Technical Reports Server (NTRS)

    Kelley, R. L.; Jarkey, D. R.; Stansbery, G.

    2014-01-01

    Policies on limiting orbital debris are found throughout the US Government, many foreign space agencies, and as adopted guidelines in the United Nations. The underlying purpose of these policies is to ensure the environment remains safe for the operation of robotic and human spacecraft in near- Earth orbit. For this reason, it is important to consider orbital debris mitigation during the design of all space vehicles. Documenting compliance with the debris mitigation guidelines occurs after the vehicle has already been designed and fabricated for many CubeSats, whereas larger satellites are evaluated throughout the design process. This paper will provide a brief explanation of the US Government Orbital Debris Mitigation Standard Practices, a discussion of international guidelines, as well as NASA's process for compliance evaluation. In addition, it will discuss the educational value of considering orbital debris mitigation requirements as a part of student built satellite design.

  6. Orbital preservation in maxillectomy.

    PubMed

    Stern, S J; Goepfert, H; Clayman, G; Byers, R; Wolf, P

    1993-07-01

    Twenty-eight previously untreated patients with squamous carcinoma of the maxillary sinus underwent maxillectomy with preservation of the orbital contents at the M. D. Anderson Cancer Center between 1971 and 1986. Eighteen patients had part or all of the orbital floor resected; nine patients were treated with radiotherapy, and nine had surgery only. Only 3 of 18 patients in this group (17%) retained significant function in the ipsilateral eye. Furthermore, local recurrence in this group was common (44%), regardless of whether postoperative radiotherapy was used. Ten patients retained the bony orbital floor; if the radiation fields did not include the eye, problems were minimal. Strong consideration should be given to orbital exenteration at the time of surgery, when the orbital floor is resected--especially if postoperative radiation fields will include the eye. PMID:8336956

  7. Mars Climate Orbiter

    NASA Technical Reports Server (NTRS)

    1998-01-01

    The purpose of this mission is to study the climate history and the water distribution of Mars. Beautiful panoramic views of the shuttle on the launch pad, engine ignition, Rocket launch, and the separation and burnout of the Solid Rocket Boosters are shown. The footage also includes an animation of the mission. Detailed views of the path that the Orbiter traversed were shown. Once the Orbiter lands on the surface of Mars, it will dig a six to eight inch hole and collect samples from the planets' surface. The animation also included the prospective return of the Orbiter to Earth over the desert of Utah. The remote sensor on the Orbiter helps in finding the exact location of the Orbiter so that scientists may collect the sample and analyze it.

  8. Remote Controlled Orbiter Capability

    NASA Technical Reports Server (NTRS)

    Garske, Michael; delaTorre, Rafael

    2007-01-01

    The Remote Control Orbiter (RCO) capability allows a Space Shuttle Orbiter to perform an unmanned re-entry and landing. This low-cost capability employs existing and newly added functions to perform key activities typically performed by flight crews and controllers during manned re-entries. During an RCO landing attempt, these functions are triggered by automation resident in the on-board computers or uplinked commands from flight controllers on the ground. In order to properly route certain commands to the appropriate hardware, an In-Flight Maintenance (IFM) cable was developed. Currently, the RCO capability is reserved for the scenario where a safe return of the crew from orbit may not be possible. The flight crew would remain in orbit and await a rescue mission. After the crew is rescued, the RCO capability would be used on the unmanned Orbiter in an attempt to salvage this national asset.

  9. Wall of fundamental constants

    SciTech Connect

    Olive, Keith A.; Peloso, Marco; Uzan, Jean-Philippe

    2011-02-15

    We consider the signatures of a domain wall produced in the spontaneous symmetry breaking involving a dilatonlike scalar field coupled to electromagnetism. Domains on either side of the wall exhibit slight differences in their respective values of the fine-structure constant, {alpha}. If such a wall is present within our Hubble volume, absorption spectra at large redshifts may or may not provide a variation in {alpha} relative to the terrestrial value, depending on our relative position with respect to the wall. This wall could resolve the contradiction between claims of a variation of {alpha} based on Keck/Hires data and of the constancy of {alpha} based on Very Large Telescope data. We derive the properties of the wall and the parameters of the underlying microscopic model required to reproduce the possible spatial variation of {alpha}. We discuss the constraints on the existence of the low-energy domain wall and describe its observational implications concerning the variation of the fundamental constants.

  10. Phyllosilicate and Olivine around a Fracture in Nili Fossae

    NASA Technical Reports Server (NTRS)

    2007-01-01

    The Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) took this observation of part of the Nili Fossae region at the western margin of the Isidis impact basin at 3:07 (UTC) on December 12, 2006, near 21.9 degrees north latitude, 78.2 degrees east longitude. The image was taken in 544 colors covering 0.36-3.92 micrometers, and shows features as small as 18 meters (60 feet) across. The image is about 11 kilometers (7 miles) wide at its narrowest point.

    The Isidis basin resulted from a gigantic impact on the surface of Mars early in the planet's history. The image of the Isidis basin at the top left is the colored elevation data from the Mars Orbiter Laser Altimeter (MOLA) overlain on a digital image mosaic from the Viking mission. Reds represent higher elevations, and blue lower elevations. The western rim of the Isidis basin has numerous, concentric troughs (or 'fossae') which may have formed during faulting associated with the impact event. Since then, the Nili Fossae region has since been heavily eroded, and is one of the most mineralogically diverse spots on Mars.

    This CRISM image targets one of region's smaller fractures. The image is shown overlain on the Viking digital image mosaic at lower left. The lower right CRISM image was constructed from three visible wavelengths (0.71, 0.60 and 0.53 microns in the red, green and blue image planes, respectively) and is close to what the human eye would see. The blue on the right of the image is an artifact from light scattering in the atmosphere. The upper right image was constructed from three infrared channels (2.38, 1.80 and 1.15 microns in the red, green and blue image planes, respectively) to highlight the mineralogy of the area. The bright green areas are rich in 'phyllosilicates,' a category of minerals including clays. The purple material along the walls of the fracture likely contains small amounts of the iron- and magnesium-rich mineral pyroxene. The yellow-brown material contains the

  11. Outcome analysis of sports-related multiple facial fractures.

    PubMed

    Hwang, Kun; You, Sun Hye; Lee, Hong Sik

    2009-05-01

    In this paper, we report a retrospective study of 236 patients with facial bone fractures from various sports who were treated at the Department of Plastic and Reconstructive Surgery, Inha University Hospital, Incheon, South Korea, between February 1996 and April 2007. The medical records of these patients were reviewed and analyzed to determine the clinical characteristics and treatment of the sports-related facial bone fractures. The highest frequency of sports-related facial bone fractures was in the age group 11 to 20 years (40.3%); there was a significant male predominance in all age groups (13.75:1). The most common causes of the injury were soccer (38.1%), baseball (16.1%), basketball (12.7%), martial arts (6.4%), and skiing or snowboarding (11%). Fractures of the nasal bone were the most common in all sports; mandible fractures were common in soccer and martial arts, orbital bone fractures were common in baseball, basketball, and ice sports, and fractures of the zygoma were frequently seen in soccer and martial arts. The main causes of the sports injuries were direct body contact (50.8%), and the most commonly associated soft tissue injuries were found in the head and neck regions (92.3%). Nasal bone fractures were the most common (54.2%), and tripod fractures were the most common type of complex injuries (4.2%). The complication rate was 3.0%. Long-term epidemiological data regarding the natural history of sports-related facial bone fractures are important for the evaluation of existing preventative measures and for the development of new methods of injury prevention and treatment. PMID:19352203

  12. Application of a geocentrifuge and sterolithographically fabricated apertures to multiphase flow in complex fracture apertures.

    SciTech Connect

    Glenn E. McCreery; Robert D. Stedtfeld; Alan T. Stadler; Daphne L. Stoner; Paul Meakin

    2005-09-01

    A geotechnical centrifuge was used to investigate unsaturated multiphase fluid flow in synthetic fracture apertures under a variety of flow conditions. The geocentrifuge subjected the fluids to centrifugal forces allowing the Bond number to be systematically changed without adjusting the fracture aperture of the fluids. The fracture models were based on the concept that surfaces generated by the fracture of brittle geomaterials have a self-affine fractal geometry. The synthetic fracture surfaces were fabricated from a transparent epoxy photopolymer using sterolithography, and fluid flow through the transparent fracture models was monitored by an optical image acquisition system. Aperture widths were chosen to be representative of the wide range of geological fractures in the vesicular basalt that lies beneath the Idaho Nation Laboratory (INL). Transitions between different flow regimes were observed as the acceleration was changed under constant flow conditions. The experiments showed the transition between straight and meandering rivulets in smooth walled apertures (aperture width = 0.508 mm), the dependence of the rivulet width on acceleration in rough walled fracture apertures (average aperture width = 0.25 mm), unstable meandering flow in rough walled apertures at high acceleration (20g) and the narrowing of the wetted region with increasing acceleration during the penetration of water into an aperture filled with wetted particles (0.875 mm diameter glass spheres).

  13. Management of frontal sinus fractures--treatment decision based on metric dislocation extent.

    PubMed

    Dalla Torre, Daniel; Burtscher, Doris; Kloss-Brandstätter, Anita; Rasse, Michael; Kloss, Frank

    2014-10-01

    The treatment of frontal sinus fractures is still a matter of research in neurosurgical and craniofacial surgery. The present study aimed to determine new criteria regarding surgical or observational treatment, especially concerning the fracture dislocation. Clinical information on 164 consecutive patients with fractures of the frontal sinus, treated at the Department of Craniomaxillofacial Surgery of the Medical University of Innsbruck from 2006 to 2010, have been evaluated. 23 female (14%) and 141 male (86%) patients suffered mainly from traffic (31.7%) and sports accidents (28.0%), followed by work accidents (20.1%), violence (3.7%) and accidents at home (3.1%). 51.8% presented an isolated fracture of the anterior wall, 47.6% both anterior and posterior wall fracture, 0.6% an isolated posterior wall fracture. Injury of the nasofrontal duct was found in 29.2%, CSF liquorrhoea in 15.9%. In total, 44.5% of the patients underwent surgical therapy, 55.5% were treated conservatively by observation. Treatment decision depended significantly on concomitant injuries of the nasofrontal duct and the presence of rhinoliquorrhoea as well as on the fracture dislocation. A new classification of frontal sinus fractures depending on their maximum dislocation is proposed. In addition, a treatment algorithm considering displacement, liquorrhoea and injury of the nasofrontal duct is presented. PMID:24942098

  14. Orbital varix thrombosis: a rare cause of unilateral proptosis

    PubMed Central

    Wade, Ryckie George; Maddock, Thomas B; Ananth, Srinivasan

    2013-01-01

    Orbital varices are thin walled, low flow, distensible veins which may rarely present with periorbital pain, proptosis or visual loss. Most orbital varices may be managed conservatively and only warrant surgery in the presence of recurrent thrombosis, disfiguring proptosis or acute visual loss. This report concerns an 84-year-old Caucasian woman who was admitted following a fall and noted to have isolated proptosis of the right eye, with vertical diplopia. All biochemical and haematological investigations were normal. A CT scan of the orbits demonstrated a serpiginous soft tissue mass within the superior portion of the right orbit, consistent with a thrombosed orbital varix. Conservative management was agreed with prism glasses and ophthalmological follow-up. PMID:23355578

  15. Management of Extensive Maxillofacial Trauma With Bony Foreign Body Within the Orbit From a Chainsaw Injury

    PubMed Central

    Craft, Randall O.; Eberlin, Kyle R.; Stella, Michael H.; Caterson, Edward J.

    2011-01-01

    Objective: The goal of this case report is to characterize injury patterns typical for chainsaw injuries to the face. We describe our approach to the soft tissue and skeletal injury patterns seen in these injuries. Methods: We present a case report of a traumatic chainsaw injury to the face. Results: A literature review of the typical injury patterns seen in chainsaw injuries to the face is discussed. Fractures to the bony orbit are on of the most common findings. Traumatic orbital fractures are often associated with other facial fractures, including those of the maxillary sinus and naso-orbital-ethmoid (NOE) region. There is a reported 47% incidence of lacrimal obstruction after NOE fractures, most caused by bone malposition or damage to the lacrimal sac or duct. Misdiagnosis of this injury pattern can lead to chronic patient morbidity. Conclusion: We present a case of traumatic orbital fracture with subsequent bony intrusion into the orbit, necessitating urgent exploration. The compound soft tissue and skeletal injury in this patient is typical for patients with associated lacrimal injury. Awareness of the injury patterns and treatment algorithms of these cases allows for appropriate assessment and intervention. PMID:22132249

  16. Orbital Causes of Incomitant Strabismus

    PubMed Central

    Lueder, Gregg T.

    2015-01-01

    Strabismus may result from abnormal innervation, structure, or function of the extraocular muscles. Abnormalities of the orbital bones or masses within the orbit may also cause strabismus due to indirect effects on the extraocular muscles. This paper reviews some disorders of the orbit that are associated with strabismus, including craniofacial malformations, orbital masses, trauma, and anomalous orbital structures. PMID:26180465

  17. Effect of isolated fractures on accelerated flow in unsaturated porous rock

    USGS Publications Warehouse

    Su, G.W.; Nimmo, J.R.; Dragila, M.I.

    2003-01-01

    Fractures that begin and end in the unsaturated zone, or isolated fractures, have been ignored in previous studies because they were generally assumed to behave as capillary barriers and remain nonconductive. We conducted a series of experiments using Berea sandstone samples to examine the physical mechanisms controlling flow in a rock containing a single isolated fracture. The input fluxes and fracture orientation were varied in these experiments. Visualization experiments using dyed water in a thin vertical slab of rock were conducted to identify flow mechanisms occurring due to the presence of the isolated fracture. Two mechanisms occurred: (1) localized flow through the rock matrix in the vicinity of the isolated fracture and (2) pooling of water at the bottom of the fracture, indicating the occurrence of film flow along the isolated fracture wall. These mechanisms were observed at fracture angles of 20 and 60 degrees from the horizontal, but not at 90 degrees. Pooling along the bottom of the fracture was observed over a wider range of input fluxes for low-angled isolated fractures compared to high-angled ones. Measurements of matrix water pressures in the samples with the 20 and 60 degree fractures also demonstrated that preferential flow occurred through the matrix in the fracture vicinity, where higher pressures occurred in the regions where faster flow was observed in the visualization experiments. The pooling length at the terminus of a 20 degree isolated fracture was measured as a function of input flux. Calculations of the film flow rate along the fracture were made using these measurements and indicated that up to 22% of the flow occurred as film flow. These experiments, apparently the first to consider isolated fractures, demonstrate that such features can accelerate flow through the unsaturated zone and should be considered when developing conceptual models.

  18. Chaotic dynamics in flow through unsaturated fractured media

    NASA Astrophysics Data System (ADS)

    Faybishenko, Boris

    Predictions of flow and transport within fractured rock in the vadose zone cannot be made without first characterizing the physics of unstable flow phenomena in unsaturated fractures. This paper introduces a new approach for studying complex flow processes in heterogeneous fractured media, using the methods of nonlinear dynamics and chaos--in particular reconstructing the system dynamics and calculating chaotic diagnostic parameters from time-series data. To demonstrate the application of chaotic analysis, this author analyzed the time-series pressure fluctuations from two water-air flow experiments conducted by Persoff and Pruess [Water Resour. Res. 31 (1995) 1175] in replicas of rough-walled rock fractures under controlled boundary conditions. This analysis showed that chaotic flow in fractures creates relaxational oscillations of liquid, gas, and capillary pressures. These pressure oscillations were used to calculate the diagnostic parameters of deterministic chaos, including correlation time, global embedding dimension, local embedding dimension, Lyapunov dimension, Lyapunov exponents, and correlation dimension. The results of the Persoff-Pruess experiments were then compared with the chaotic analysis of laboratory dripping-water experiments in fracture models and field-infiltration experiments in fractured basalt. This comparison allowed us to conjecture that intrinsic fracture flow and dripping, as well as extrinsic water dripping (from a fracture) subjected to a capillary-barrier effect, are deterministic-chaotic processes with a certain random component. The unsaturated fractured rock is a dynamic system that exhibits chaotic behavior because the flow processes are nonlinear, dissipative, and sensitive to initial conditions, with chaotic fluctuations generated by intrinsic properties of the system, not random external factors. Identifying a system as deterministically chaotic is important for developing appropriate short- and long-term prediction models

  19. Fracture mechanics: 26. volume

    SciTech Connect

    Reuter, W.G.; Underwood, J.H.; Newman, J.C. Jr.

    1995-12-31

    The original objective of these symposia was to promote technical interchange between researchers from the US and worldwide in the field of fracture. This objective was recently expanded to promote technical interchange between researchers in the field of fatigue and fracture. The symposium began with the Swedlow Memorial Lecture entitled ``Patterns and Perspectives in Applied Fracture Mechanics.`` The remaining 42 papers are divided into the following topical sections: Constraint crack initiation; Constraint crack growth; Weldments; Engineered materials; Subcritical crack growth; Dynamic loading; and Applications. Papers within the scope of the Energy Data Base have been processed separately.

  20. Liquid Wall Chambers

    SciTech Connect

    Meier, W R

    2011-02-24

    The key feature of liquid wall chambers is the use of a renewable liquid layer to protect chamber structures from target emissions. Two primary options have been proposed and studied: wetted wall chambers and thick liquid wall (TLW) chambers. With wetted wall designs, a thin layer of liquid shields the structural first wall from short ranged target emissions (x-rays, ions and debris) but not neutrons. Various schemes have been proposed to establish and renew the liquid layer between shots including flow-guiding porous fabrics (e.g., Osiris, HIBALL), porous rigid structures (Prometheus) and thin film flows (KOYO). The thin liquid layer can be the tritium breeding material (e.g., flibe, PbLi, or Li) or another liquid metal such as Pb. TLWs use liquid jets injected by stationary or oscillating nozzles to form a neutronically thick layer (typically with an effective thickness of {approx}50 cm) of liquid between the target and first structural wall. In addition to absorbing short ranged emissions, the thick liquid layer degrades the neutron flux and energy reaching the first wall, typically by {approx}10 x x, so that steel walls can survive for the life of the plant ({approx}30-60 yrs). The thick liquid serves as the primary coolant and tritium breeding material (most recent designs use flibe, but the earliest concepts used Li). In essence, the TLW places the fusion blanket inside the first wall instead of behind the first wall.

  1. Imaging of orbital disorders.

    PubMed

    Cunnane, Mary Beth; Curtin, Hugh David

    2016-01-01

    Diseases of the orbit can be categorized in many ways, but in this chapter we shall group them according to etiology. Inflammatory diseases of the orbits may be infectious or noninfectious. Of the infections, orbital cellulitis is the most common and typically arises as a complication of acute sinusitis. Of the noninfectious, inflammatory conditions, thyroid orbitopathy is the most common and results in enlargement of the extraocular muscles and proliferation of the orbital fat. Idiopathic orbital inflammatory syndrome is another cause of inflammation in the orbit, which may mimic thyroid orbitopathy or even neoplasm, but typically presents with pain. Masses in the orbit may be benign or malignant and the differential diagnosis primarily depends on the location of the mass lesion, and on the age of the patient. Lacrimal gland tumors may be lymphomas or epithelial lesions of salivary origin. Extraocular muscle tumors may represent lymphoma or metastases. Tumors of the intraconal fat are often benign, typically hemangiomas or schwannomas. Finally, globe tumors may be retinoblastomas (in children), or choroidal melanomas or metastases in adults. PMID:27432687

  2. Harmonically excited orbital variations

    SciTech Connect

    Morgan, T.

    1985-08-06

    Rephrasing the equations of motion for orbital maneuvers in terms of Lagrangian generalized coordinates instead of Newtonian rectangular cartesian coordinates can make certain harmonic terms in the orbital angular momentum vector more readily apparent. In this formulation the equations of motion adopt the form of a damped harmonic oscillator when torques are applied to the orbit in a variationally prescribed manner. The frequencies of the oscillator equation are in some ways unexpected but can nonetheless be exploited through resonant forcing functions to achieve large secular variations in the orbital elements. Two cases are discussed using a circular orbit as the control case: (1) large changes in orbital inclination achieved by harmonic excitation rather than one impulsive velocity change, and (2) periodic and secular changes to the longitude of the ascending node using both stable and unstable excitation strategies. The implications of these equations are also discussed for both artificial satellites and natural satellites. For the former, two utilitarian orbits are suggested, each exploiting a form of harmonic excitation. 5 refs.

  3. Visualization of atom's orbits.

    PubMed

    Kim, Byungwhan

    2014-02-01

    High-resolution imaging techniques have been used to obtain views of internal shapes of single atoms or columns of atoms. This review article focuses on the visualization of internal atomic structures such as the configurations of electron orbits confined to atoms. This is accomplished by applying visualization techniques to the reported images of atoms or molecules as well as static and dynamic ions in a plasma. It was found that the photon and electron energies provide macroscopic and microscopic views of the orbit structures of atoms, respectively. The laser-imaged atoms showed a rugged orbit structure, containing alternating dark and bright orbits believed to be the pathways for an externally supplied laser energy and internally excited electron energy, respectively. By contrast, the atoms taken by the electron microscopy provided a structure of fine electron orbits, systematically formed in increasing order of grayscale representing the energy state of an orbit. This structure was identical to those of the plasma ions. The visualized electronic structures played a critical role in clarifying vague postulates made in the Bohr model. Main features proposed in the atomic model are the dynamic orbits absorbing an externally supplied electromagnetic energy, electron emission from them while accompanying light radiation, and frequency of electron waves not light. The light-accompanying electrons and ionic speckles induced by laser light signify that light is composed of electrons and ions. PMID:24749452

  4. Orbit Stabilization of Nanosat

    SciTech Connect

    JOHNSON,DAVID J.

    1999-12-01

    An algorithm is developed to control a pulsed {Delta}V thruster on a small satellite to allow it to fly in formation with a host satellite undergoing time dependent atmospheric drag deceleration. The algorithm uses four short thrusts per orbit to correct for differences in the average radii of the satellites due to differences in drag and one thrust to symmetrize the orbits. The radial difference between the orbits is the only input to the algorithm. The algorithm automatically stabilizes the orbits after ejection and includes provisions to allow azimuthal positional changes by modifying the drag compensation pulses. The algorithm gives radial and azimuthal deadbands of 50 cm and 3 m for a radial measurement accuracy of {+-} 5 cm and {+-} 60% period variation in the drag coefficient of the host. Approaches to further reduce the deadbands are described. The methodology of establishing a stable orbit after ejection is illustrated in an appendix. The results show the optimum ejection angle to minimize stabilization thrust is upward at 86{sup o} from the orbital velocity. At this angle the stabilization velocity that must be supplied by the thruster is half the ejection velocity. An ejection velocity of 0.02 m/sat 86{sup o} gives an azimuthal separation after ejection and orbit stabilization of 187 m. A description of liquid based gas thrusters suitable for the satellite control is included in an appendix.

  5. Mechanical Coal-Face Fracturer

    NASA Technical Reports Server (NTRS)

    Collins, E. R., Jr.

    1984-01-01

    Radial points on proposed drill bit take advantage of natural fracture planes of coal. Radial fracture points retracted during drilling and impacted by piston to fracture coal once drilling halts. Group of bits attached to array of pneumatic drivers to fracture large areas of coal face.

  6. Removal of orbital debris

    NASA Technical Reports Server (NTRS)

    Petro, Andrew J.; Talent, David L.

    1989-01-01

    The several methods presently identified for the reduction of orbital debris populations are broadly classifiable as either preventive or remedial, and fall within distinctive operational regimes. For all particles, (1) in the 250-2000-km altitude band, intelligent sweepers may be used; (2) for large objects, in the 80-250-km altitude band, orbital decay renders removal impractical; (3) for the 250-750-km altitude band, deorbit devices should be used; (4) for 750-2500-km altitude, OMV rendezvous for propulsive deorbit package attachment is foreseeable; and beyond 2500 km, (5) propulsive escape from earth orbit is required.

  7. Working in orbit and beyond

    SciTech Connect

    Lorr, D.B. ); Garshnek, V. ); Cadoux, C. )

    1989-01-01

    This book contains papers presented at a conference on the challenges for space medicine. Topics covered include radiation hazards in low earth orbit, polar orbit, geosynchronous orbit, and deep space.

  8. Hebes Chasma Wall

    NASA Technical Reports Server (NTRS)

    2005-01-01

    [figure removed for brevity, see original site]

    The THEMIS VIS camera is capable of capturing color images of the Martian surface using five different color filters. In this mode of operation, the spatial resolution and coverage of the image must be reduced to accommodate the additional data volume produced from using multiple filters. To make a color image, three of the five filter images (each in grayscale) are selected. Each is contrast enhanced and then converted to a red, green, or blue intensity image. These three images are then combined to produce a full color, single image. Because the THEMIS color filters don't span the full range of colors seen by the human eye, a color THEMIS image does not represent true color. Also, because each single-filter image is contrast enhanced before inclusion in the three-color image, the apparent color variation of the scene is exaggerated. Nevertheless, the color variation that does appear is representative of some change in color, however subtle, in the actual scene. Note that the long edges of THEMIS color images typically contain color artifacts that do not represent surface variation.

    This false color image of a canyon wall located in Hebes Chasma, was collected during the Southern Fall season. Hebes Chasma is located north of Valles Marineris.

    Image information: VIS instrument. Latitude -1.5, Longitude 284.5 East (75.5 West). 35 meter/pixel resolution.

    Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.

    NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for

  9. Orbit Determination Issues for Libration Point Orbits

    NASA Technical Reports Server (NTRS)

    Beckman, Mark; Bauer, Frank (Technical Monitor)

    2002-01-01

    Libration point mission designers require knowledge of orbital accuracy for a variety of analyses including station keeping control strategies, transfer trajectory design, and formation and constellation control. Past publications have detailed orbit determination (OD) results from individual libration point missions. This paper collects both published and unpublished results from four previous libration point missions (ISEE (International Sun-Earth Explorer) -3, SOHO (Solar and Heliospheric Observatory), ACE (Advanced Composition Explorer) and MAP (Microwave Anisotropy Probe)) supported by Goddard Space Flight Center's Guidance, Navigation & Control Center. The results of those missions are presented along with OD issues specific to each mission. All past missions have been limited to ground based tracking through NASA ground sites using standard range and Doppler measurement types. Advanced technology is enabling other OD options including onboard navigation using seaboard attitude sensors and the use of the Very Long Baseline Interferometry (VLBI) measurement Delta Differenced One-Way Range (DDOR). Both options potentially enable missions to reduce coherent dedicated tracking passes while maintaining orbital accuracy. With the increased projected loading of the DSN (Deep Space Network), missions must find alternatives to the standard OD scenario.

  10. Experimental Hydromechanical Characterization and Numerical Modelling of a Fractured and Porous Sandstone

    NASA Astrophysics Data System (ADS)

    Souley, Mountaka; Lopez, Philippe; Boulon, Marc; Thoraval, Alain

    2015-05-01

    The experimental device previously used to study the hydromechanical behaviour of individual fractures on a laboratory scale, was adapted to make it possible to measure flow through porous rock mass samples in addition to fracture flows. A first series of tests was performed to characterize the hydromechanical behaviour of the fracture individually as well as the porous matrix (sandstone) comprising the fracture walls. A third test in this series was used to validate the experimental approach. These tests showed non-linear evolution of the contact area on the fracture walls with respect to effective normal stress. Consequently, a non-linear relationship was noted between the hydraulic aperture on the one hand, and the effective normal stress and mechanical opening on the other hand. The results of the three tests were then analysed by numerical modelling. The VIPLEF/HYDREF numerical codes used take into account the dual-porosity of the sample (fracture + rock matrix) and can be used to reproduce hydromechanical loading accurately. The analyses show that the relationship between the hydraulic aperture of the fracture and the mechanical closure has a significant effect on fracture flow rate predictions. By taking simultaneous measurements of flow in both fracture and rock matrix, we were able to carry out a global evaluation of the conceptual approach used.

  11. The role of local stress perturbation on the simultaneous opening of orthogonal fractures

    NASA Astrophysics Data System (ADS)

    Boersma, Quinten; Hardebol, Nico; Barnhoorn, Auke; Bertotti, Giovanni; Drury, Martyn

    2016-04-01

    Orthogonal fracture networks (ladder-like networks) are arrangements that are commonly observed in outcrop studies. They form a particularly dense and well connected network which can play an important role in the effective permeability of tight hydrocarbon or geothermal reservoirs. One issue is the extent to which both the long systematic and smaller cross fractures can be simultaneously critically stressed under a given stress condition. Fractures in an orthogonal network form by opening mode-I displacements in which the main component is separation of the two fracture walls. This opening is driven by effective tensile stresses as the smallest principle stress acting perpendicular to the fracture wall, which accords with linear elastic fracture mechanics. What has been well recognized in previous field and modelling studies is how both the systematic fractures and perpendicular cross fractures require the minimum principle stress to act perpendicular to the fracture wall. Thus, these networks either require a rotation of the regional stress field or local perturbations in stress field. Using a mechanical finite element modelling software, a geological case of layer perpendicular systematic mode I opening fractures is generated. New in our study is that we not only address tensile stresses at the boundary, but also address models using pore fluid pressure. The local stress in between systematic fractures is then assessed in order to derive the probability and orientation of micro crack propagation using the theory of sub critical crack growth and Griffith's theory. Under effective tensile conditions, the results indicate that in between critically spaced systematic fractures, local effective tensile stresses flip. Therefore the orientation of the least principle stress will rotate 90°, hence an orthogonal fracture is more likely to form. Our new findings for models with pore fluid pressures instead of boundary tension show that the magnitude of effective tension

  12. Cell wall integrity

    PubMed Central

    Pogorelko, Gennady; Lionetti, Vincenzo; Bellincampi, Daniela; Zabotina, Olga

    2013-01-01

    The plant cell wall, a dynamic network of polysaccharides and glycoproteins of significant compositional and structural complexity, functions in plant growth, development and stress responses. In recent years, the existence of plant cell wall integrity (CWI) maintenance mechanisms has been demonstrated, but little is known about the signaling pathways involved, or their components. Examination of key mutants has shed light on the relationships between cell wall remodeling and plant cell responses, indicating a central role for the regulatory network that monitors and controls cell wall performance and integrity. In this review, we present a short overview of cell wall composition and discuss post-synthetic cell wall modification as a valuable approach for studying CWI perception and signaling pathways. PMID:23857352

  13. Combined endoscopic and subciliary orbital decompression for thyroid-related compressive optic neuropathy.

    PubMed

    Graham, S M; Carter, K D

    1997-09-01

    Compressive optic neuropathy is a feared, although unusual, complication of thyroid-related orbitopathy. A variety of surgical approaches have been described to achieve orbital decompression and alleviate the hallmark apical orbital crowding of this condition. We describe a subciliary anterior orbitotomy approach to the floor combined with an endoscopic medial wall resection. The anterior orbitotomy allows removal of the bones of the orbital floor both medial and lateral to the canal of the infraorbital nerve. The anterior orbital floor is retained for globe support. This combined approach retains the low morbidity of the endoscopic operation while achieving increased apical medial orbital wall and orbital floor decompression. We describe two illustrative cases where this approach produced a dramatic improvement in visual function. The surgical refinements associated with this combined approach offer technical advantages over other operations in the treatment of thyroid-related compressive optic neuropathy. PMID:9403938

  14. Femur fracture repair - discharge

    MedlinePlus

    ... McCormack RG, Lopez CA. Commonly encountered fractures in sports medicine. In: Miller MD, Thompson SR, eds. DeLee and Drez's Orthopaedic Sports Medicine. 4th ed. Philadelphia, PA: Elsevier Saunders; 2015:chap ...

  15. Metatarsal stress fractures - aftercare

    MedlinePlus

    ... McCormack RG, Lopez CA. Commonly encountered fractures in sports medicine. In: Miller MD, Thompson SR, eds. DeLee and Drez's Orthopaedic Sports Medicine . 4th ed. Philadelphia, PA: Saunders Elsevier; 2014:chap. ...

  16. Clavicle Fracture (Broken Collarbone)

    MedlinePlus

    ... place and the fragments are severely out of alignment. A large bump over the fracture site may ... bone fragments are first repositioned into their normal alignment, and then held in place with special screws ...

  17. Sprains, Strains and Fractures

    MedlinePlus

    ... are useful for finding soft issue injuries (including torn ligaments) and stress fractures. Treatment will depend on ... weeks. Professional athletes may undergo surgery to repair torn ligaments. Oral anti-inflammatory medication, such as ibuprofen, ...

  18. Lisfranc (Midfoot) Fractures

    MedlinePlus

    ... broken or ligaments that support the midfoot are torn. The severity of the injury can vary from ... bones are broken (fractured) or the ligaments are torn (ruptured). Injuries can vary, from a simple injury ...

  19. Ankle fracture - aftercare

    MedlinePlus

    ... page: //medlineplus.gov/ency/patientinstructions/000548.htm Ankle fracture - aftercare To use the sharing features on this ... Sit with your foot elevated higher than your knee at least 4 times a day Apply an ...

  20. Fractures in medieval Scotland.

    PubMed

    MacLennan, W J

    2001-04-01

    The prevalence of fractures in medieval Scotland is assessed, particular attention being given to excavations of cemeteries beside three Carmelite cemeteries, at Aberdeen, Perth and Linlithgow, and another one at Whithorn Abbey. In the friaries the prevalence of fractures was 7.6% and in Whithorn it was 5.0%. These figures are comparable with an estimated prevalence of 7.2% for individuals between 0 and 65 years in present day Scotland. Males were more at risk of fractures than females, but a small group from both genders had been struck on the head by weapons. A study from a rural cemetery in England indicates that both male and female peasants had a much higher risk of fractures than their urban counterparts. PMID:11394343

  1. Suspensions in hydraulic fracturing

    SciTech Connect

    Shah, S.N.

    1996-12-31

    Suspensions or slurries are widely used in well stimulation and hydraulic fracturing processes to enhance the production of oil and gas from the underground hydrocarbon-bearing formation. The success of these processes depends significantly upon having a thorough understanding of the behavior of suspensions used. Therefore, the characterization of suspensions under realistic conditions, for their rheological and hydraulic properties, is very important. This chapter deals with the state-of-the-art hydraulic fracturing suspension technology. Specifically it deals with various types of suspensions used in well stimulation and fracturing processes, their rheological characterization and hydraulic properties, behavior of suspensions in horizontal wells, review of proppant settling velocity and proppant transport in the fracture, and presently available measurement techniques for suspensions and their merits. Future industry needs for better understanding of the complex behavior of suspensions are also addressed. 74 refs., 21 figs., 1 tab.

  2. Numerical modelling of fracture in human arteries.

    PubMed

    Ferrara, A; Pandolfi, A

    2008-10-01

    We present 3D finite element models of atherosclerotic arteries, used to investigate the influence of the geometry and tissue properties on the plaque rupture caused by overexpansion. We adopted a geometry reconstructed from a contiguous set of in vitro magnetic resonance images of a damaged artery. The artery wall is divided in three layers (adventitia, media and intima) and is discretized into tetrahedral finite elements. The artery material is described with a hyperelastic two-fiber anisotropic model proposed by Holzapfel et al. 2000. A new constitutive framework for arterial wall mechanics and a comparative study of material models. J Elasticity 61(1):1-48, while the plaque is assumed to be transversely isotropic. Cracks induced by mechanical actions are represented through cohesive surfaces, and are allowed to develop along solid elements boundaries only. Fractures are explicitly introduced in the discretized model at the locations where the tensile strength of the material is reached. PMID:19230149

  3. Dynamic fracture toughness

    NASA Technical Reports Server (NTRS)

    Kobayashi, A. S.; Ramulu, M.; Dadkhah, M. S.; Yang, K.-H.; Kang, B. S. J.

    1986-01-01

    Dynamic fracture toughness versus crack velocity relations of Homalite-100, polycarbonate, hardened 4340 steel and reaction bonded silicon nitride are reviewed and discrepancies with published data and their probable causes are discussed. Data scatter in published data are attributed in part to the observed fluctuations in crack velocities. The results reaffirmed our previous conclusion that the dynamic fracture toughness versus crack velocity relation is specimen dependent and that the dynamic arrest stress intensity factor is not a unique material property.

  4. Habitability study shuttle orbiter

    NASA Technical Reports Server (NTRS)

    1973-01-01

    Habitability design concepts for the Shuttle Orbiter Program are provided for MSC. A variety of creative solutions for the stated tasks are presented. Sketches, mock-ups, mechanicals and models are included for establishing a foundation for future development.

  5. Habitability study shuttle orbiter

    NASA Technical Reports Server (NTRS)

    1972-01-01

    Studies of the habitability of the space shuttle orbiter are briefly summarized. Selected illustrations and descriptions are presented for: crew compartment, hygiene facilities, food system and galley, and storage systems.

  6. ARTEMIS Orbits Magnetic Moon

    NASA Video Gallery

    NASA's THEMIS spacecraft have completed their mission and are still working perfectly, so NASA is re-directing the outermost two spacecraft to special orbits around the Moon. Now called ARTEMIS, th...

  7. Space Shuttle Orbiter ECLSS.

    NASA Technical Reports Server (NTRS)

    Stoll, O. T.; Laubach, G. E.; Gibb, J. W.

    1973-01-01

    The Orbiter Environmental Control and Life Support System (ECLSS) provides the functions of atmosphere revitalization, crew life support, active thermal conditioning, and airlock support for EVA and docking activities. The ECLSS must satisfy the requirements of orbital missions with four to ten crewmembers and mission duration of a few hours to 30 days and the requirements associated with an atmospheric horizontal flight test program and ferry flight missions. The ECLSS development plan utilizes an ECLSS ground test article and thermal/vacuum testing to support the first horizontal flight test at the end of 1976. The ground testing and horizontal flight test program certify the Orbiter ECLSS for the first orbital flight in early 1978.

  8. MMS Orbit Animation

    NASA Video Gallery

    This animation shows the orbits of Magnetospheric Multiscale (MMS)mission, a Solar Terrestrial Probes mission comprising of fouridentically instrumented spacecraft that will study the Earth’sm...

  9. Altimetry, Orbits and Tides

    NASA Technical Reports Server (NTRS)

    Colombo, O. L.

    1984-01-01

    The nature of the orbit error and its effect on the sea surface heights calculated with satellite altimetry are explained. The elementary concepts of celestial mechanics required to follow a general discussion of the problem are included. Consideration of errors in the orbits of satellites with precisely repeating ground tracks (SEASAT, TOPEX, ERS-1, POSEIDON, amongst past and future altimeter satellites) are detailed. The theoretical conclusions are illustrated with the numerical results of computer simulations. The nature of the errors in this type of orbits is such that this error can be filtered out by using height differences along repeating (overlapping) passes. This makes them particularly valuable for the study and monitoring of changes in the sea surface, such as tides. Elements of tidal theory, showing how these principles can be combined with those pertinent to the orbit error to make direct maps of the tides using altimetry are presented.

  10. Imaging in orbital trauma

    PubMed Central

    Lin, Ken Y.; Ngai, Philip; Echegoyen, Julio C.; Tao, Jeremiah P.

    2012-01-01

    Orbital trauma is one of the most common reasons for ophthalmology specialty consultation in the emergency department setting. We survey the literature from 1990 to present to describe the role of computed tomography (CT), magnetic resonance imaging (MRI) and their associated angiography in some of the most commonly encountered orbital trauma conditions. CT orbit can often detect certain types of foreign bodies, lens dislocation, ruptured globe, choroidal or retinal detachments, or cavernous sinus thrombosis and thus complement a bedside ophthalmic exam that can sometimes be limited in the setting of trauma. CT remains the workhorse for acute orbital trauma owing to its rapidity and ability to delineate bony abnormalities; however MRI remains an important modality in special circumstances such as soft tissue assessment or with organic foreign bodies. PMID:23961028

  11. Tethered orbital refueling study

    NASA Technical Reports Server (NTRS)

    Fester, Dale A.; Rudolph, L. Kevin; Kiefel, Erlinda R.; Abbott, Peter W.; Grossrode, Pat

    1986-01-01

    One of the major applications of the space station will be to act as a refueling depot for cryogenic-fueled space-based orbital transfer vehicles (OTV), Earth-storable fueled orbit maneuvering vehicles, and refurbishable satellite spacecraft using hydrazine. One alternative for fuel storage at the space station is a tethered orbital refueling facility (TORF), separated from the space station by a sufficient distance to induce a gravity gradient force that settles the stored fuels. The technical feasibility was examined with the primary focus on the refueling of LO2/LH2 orbital transfer vehicles. Also examined was the tethered facility on the space station. It was compared to a zero-gravity facility. A tethered refueling facility should be considered as a viable alternative to a zero-gravity facility if the zero-gravity fluid transfer technology, such as the propellant management device and no vent fill, proves to be difficult to develop with the required performance.

  12. Aerobraking orbital transfer vehicle

    NASA Technical Reports Server (NTRS)

    Scott, Carl D. (Inventor); Nagy, Kornel (Inventor); Roberts, Barney B. (Inventor); Ried, Robert C. (Inventor); Kroll, Kenneth R. (Inventor); Gamble, Joe (Inventor)

    1989-01-01

    An aerobraking orbital transfer vehicle which includes an aerobraking device which also serves as a heat shield in the shape of a raked-off elliptic or circular cone with a circular or elliptical base, and with an ellipsoid or other blunt shape nose. The aerobraking device is fitted with a toroid-like skirt and is integral with the support structure of the propulsion system and other systems of the space vehicle. The vehicle is intended to be transported in components to a space station in lower earth orbit where it is assembled for use as a transportation system from low earth orbit to geosynchronous earth orbit and return. Conventional guidance means are included for autonomous flight.

  13. Report on orbital debris

    NASA Technical Reports Server (NTRS)

    1989-01-01

    The success of space endeavors depends upon a space environment sufficiently free of debris to enable the safe and dependable operation of spacecraft. An environment overly cluttered with debris would threaten the ability to utilize space for a wide variety of scientific, technological, military, and commercial purposes. Man made space debris (orbital debris) differs from natural meteoroids because it remains in earth orbit during its lifetime and is not transient through the space around the Earth. The orbital debris environment is considered. The space environment is described along with sources of orbital debris. The current national space policy is examined, along with ways to minimize debris generation and ways to survive the debris environment. International efforts, legal issues and commercial regulations are also examined.

  14. Hybrid fracture and the transition from extension fracture to shear fracture.

    PubMed

    Ramsey, Jonathan M; Chester, Frederick M

    2004-03-01

    Fracture is a fundamental mechanism of material failure. Two basic types of brittle fractures are commonly observed in rock deformation experiments--extension (opening mode) fractures and shear fractures. For nearly half a century it has been hypothesized that extension and shear fractures represent end-members of a continuous spectrum of brittle fracture types. However, observations of transitional fractures that display both opening and shear modes (hybrids) in naturally deformed rock have often remained ambiguous, and a clear demonstration of hybrid fracture formation has not been provided by experiments. Here we present the results of triaxial extension experiments on Carrara marble that show a continuous transition from extension fracture to shear fracture with an increase in compressive stress. Hybrid fractures form under mixed tensile and compressive stress states at acute angles to the maximum principal compressive stress. Fracture angles are greater than those observed for extension fractures and less than those observed for shear fractures. Fracture surfaces also display a progressive change from an extension to shear fracture morphology. PMID:14999279

  15. FRACTURING FLUID CHARACTERIZATION FACILITY

    SciTech Connect

    Subhash Shah

    2000-08-01

    Hydraulic fracturing technology has been successfully applied for well stimulation of low and high permeability reservoirs for numerous years. Treatment optimization and improved economics have always been the key to the success and it is more so when the reservoirs under consideration are marginal. Fluids are widely used for the stimulation of wells. The Fracturing Fluid Characterization Facility (FFCF) has been established to provide the accurate prediction of the behavior of complex fracturing fluids under downhole conditions. The primary focus of the facility is to provide valuable insight into the various mechanisms that govern the flow of fracturing fluids and slurries through hydraulically created fractures. During the time between September 30, 1992, and March 31, 2000, the research efforts were devoted to the areas of fluid rheology, proppant transport, proppant flowback, dynamic fluid loss, perforation pressure losses, and frictional pressure losses. In this regard, a unique above-the-ground fracture simulator was designed and constructed at the FFCF, labeled ''The High Pressure Simulator'' (HPS). The FFCF is now available to industry for characterizing and understanding the behavior of complex fluid systems. To better reflect and encompass the broad spectrum of the petroleum industry, the FFCF now operates under a new name of ''The Well Construction Technology Center'' (WCTC). This report documents the summary of the activities performed during 1992-2000 at the FFCF.

  16. Treatment of Thoracolumbar Fracture

    PubMed Central

    Kim, Byung-Guk; Shin, Dong-Eun

    2015-01-01

    The most common fractures of the spine are associated with the thoracolumbar junction. The goals of treatment of thoracolumbar fracture are leading to early mobilization and rehabilitation by restoring mechanical stability of fracture and inducing neurologic recovery, thereby enabling patients to return to the workplace. However, it is still debatable about the treatment methods. Neurologic injury should be identified by thorough physical examination for motor and sensory nerve system in order to determine the appropriate treatment. The mechanical stability of fracture also should be evaluated by plain radiographs and computed tomography. In some cases, magnetic resonance imaging is required to evaluate soft tissue injury involving neurologic structure or posterior ligament complex. Based on these physical examinations and imaging studies, fracture stability is evaluated and it is determined whether to use the conservative or operative treatment. The development of instruments have led to more interests on the operative treatment which saves mobile segments without fusion and on instrumentation through minimal invasive approach in recent years. It is still controversial for the use of these treatments because there have not been verified evidences yet. However, the morbidity of patients can be decreased and good clinical and radiologic outcomes can be achieved if the recent operative treatments are used carefully considering the fracture pattern and the injury severity. PMID:25705347

  17. Partonic orbital angular momentum

    NASA Astrophysics Data System (ADS)

    Arash, Firooz; Taghavi-Shahri, Fatemeh; Shahveh, Abolfazl

    2013-04-01

    Ji's decomposition of nucleon spin is used and the orbital angular momentum of quarks and gluon are calculated. We have utilized the so called valon model description of the nucleon in the next to leading order. It is found that the average orbital angular momentum of quarks is positive, but small, whereas that of gluon is negative and large. Individual quark flavor contributions are also calculated. Some regularities on the total angular momentum of the quarks and gluon are observed.

  18. A tapestry of orbits

    SciTech Connect

    King-Hele, D.

    1992-01-01

    In this book, the author describes how orbital research developed to yield a rich harvest of knowledge about the earth and its atmosphere. King-Hele relates a personal account of this research based on analysis of satellite orbits between 1957 and 1990 conducted from the Royal Aircraft Establishment in Farnborough England. The early research methods used before the launch of Sputnik in 1957 are discussed.

  19. Suspension flow and sedimentation in self-affine fractures

    NASA Astrophysics Data System (ADS)

    Shing Lo, Tak; Koplik, Joel

    2012-05-01

    The transport and gravitational sedimentation of a particulate suspension in fracture joints with self-affinely rough walls is studied by lattice Boltzmann numerical simulations. We consider either homogeneous or bidisperse distributions of non-Brownian spheres in a Newtonian fluid, driven through a fracture by a pressure gradient, and acted upon by gravity. Most results concern the case of open fractures, in which the two walls of the channel do not approach closely enough to block the flow. We present profiles of particle density and profiles of particle and fluid velocities, along with total flow rates and characterizations of the sediment, for three values of particle concentration and a range of buoyancy and Reynolds numbers, principally in the inertial regime. We systematically study the effects of increasing the pressure gradient and the strength of sedimentation and compare the results to those for channel bounded by flat surfaces. We find that both the flow rate and the average particle velocity for flows through an open fracture, when suitably normalized, depend only on the volume fraction of the particles and the buoyancy number in the steady state regardless of the pressure drop, and observe interesting scaling laws in the large buoyancy number limit. We also investigate the possibility for correlations between the surface morphology of the sediment region and the geometry of the underlying fracture surface in the strong sedimentation limit, but no evidence for correlation is found.

  20. Transport of Particle Swarms Through Variable Aperture Fractures

    NASA Astrophysics Data System (ADS)

    Boomsma, E.; Pyrak-Nolte, L. J.

    2012-12-01

    Particle transport through fractured rock is a key concern with the increased use of micro- and nano-size particles in consumer products as well as from other activities in the sub- and near surface (e.g. mining, industrial waste, hydraulic fracturing, etc.). While particle transport is often studied as the transport of emulsions or dispersions, particles may also enter the subsurface from leaks or seepage that lead to particle swarms. Swarms are drop-like collections of millions of colloidal-sized particles that exhibit a number of unique characteristics when compared to dispersions and emulsions. Any contaminant or engineered particle that forms a swarm can be transported farther, faster, and more cohesively in fractures than would be expected from a traditional dispersion model. In this study, the effects of several variable aperture fractures on colloidal swarm cohesiveness and evolution were studied as a swarm fell under gravity and interacted with the fracture walls. Transparent acrylic was used to fabricate synthetic fracture samples with (1) a uniform aperture, (2) a converging region followed by a uniform region (funnel shaped), (3) a uniform region followed by a diverging region (inverted funnel), and (4) a cast of a an induced fracture from a carbonate rock. All of the samples consisted of two blocks that measured 100 x 100 x 50 mm. The minimum separation between these blocks determined the nominal aperture (0.5 mm to 20 mm). During experiments a fracture was fully submerged in water and swarms were released into it. The swarms consisted of a dilute suspension of 3 micron polystyrene fluorescent beads (1% by mass) with an initial volume of 5μL. The swarms were illuminated with a green (525 nm) LED array and imaged optically with a CCD camera. The variation in fracture aperture controlled swarm behavior. Diverging apertures caused a sudden loss of confinement that resulted in a rapid change in the swarm's shape as well as a sharp increase in its velocity

  1. The Lunar Orbital Prospector

    NASA Technical Reports Server (NTRS)

    Redd, Frank J.; Cantrell, James N.; Mccurdy, Greg

    1992-01-01

    The establishment of lunar bases will not end the need for remote sensing of the lunar surface by orbiting platforms. Human and robotic surface exploration will necessarily be limited to some proximate distance from the support base. Near real-time, high-resolution, global characterization of the lunar surface by orbiting sensing systems will continue to be essential to the understanding of the Moon's geophysical structure and the location of exploitable minerals and deposits of raw materials. The Lunar Orbital Prospector (LOP) is an orbiting sensing platform capable of supporting a variety of modular sensing packages. Serviced by a lunar-based shuttle, the LOP will permit the exchange of instrument packages to meet evolving mission needs. The ability to recover, modify, and rotate sensing packages allows their reuse in varying combinations. Combining this flexibility with robust orbit modification capabilities and near real-time telemetry links provides considerable system responsiveness. Maintenance and modification of the LOP orbit are accomplished through use of an onboard propulsion system that burns lunar-supplied oxygen and aluminum. The relatively low performance of such a system is more than compensated for by the elimination of the need for Earth-supplied propellants. The LOP concept envisions a continuous expansion of capability through the incorporation of new instrument technologies and the addition of platforms.

  2. The Exoplanet Orbit Database

    NASA Astrophysics Data System (ADS)

    Wright, J. T.; Fakhouri, O.; Marcy, G. W.; Han, E.; Feng, Y.; Johnson, John Asher; Howard, A. W.; Fischer, D. A.; Valenti, J. A.; Anderson, J.; Piskunov, N.

    2011-04-01

    We present a database of well-determined orbital parameters of exoplanets, and their host stars' properties. This database comprises spectroscopic orbital elements measured for 427 planets orbiting 363 stars from radial velocity and transit measurements as reported in the literature. We have also compiled fundamental transit parameters, stellar parameters, and the method used for the planets discovery. This Exoplanet Orbit Database includes all planets with robust, well measured orbital parameters reported in peer-reviewed articles. The database is available in a searchable, filterable, and sortable form online through the Exoplanets Data Explorer table, and the data can be plotted and explored through the Exoplanet Data Explorer plotter. We use the Data Explorer to generate publication-ready plots, giving three examples of the signatures of exoplanet migration and dynamical evolution: We illustrate the character of the apparent correlation between mass and period in exoplanet orbits, the different selection biases between radial velocity and transit surveys, and that the multiplanet systems show a distinct semimajor-axis distribution from apparently singleton systems.

  3. Overall view of the Orbiter Servicing Structure within the Orbiter ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Overall view of the Orbiter Servicing Structure within the Orbiter Processing Facility at Kennedy Space Center. Can you see any hint of the Orbiter Discovery? It is in there. - Space Transportation System, Orbiter Discovery (OV-103), Lyndon B. Johnson Space Center, 2101 NASA Parkway, Houston, Harris County, TX

  4. Internal Arrangement of the Skylab Orbital Workshop

    NASA Technical Reports Server (NTRS)

    1971-01-01

    The wardroom deck of the Orbital Workshop, showing the living quarters arrangement, is seen here in good detail. From left to right is the dining area, waste management, and sleeping quarters. Portable restraints are on the wall beside the sleeping quarters. The ergometer for the vectorcardiograph (Experiment - M093) and lower-body Negative Pressure (Experiment M092) unit, used in some of the medical experiments, are in the foreground. The round brown object in the center of the room is the trash disposal airlock.

  5. [Extraskeletal mesenchymal chondrosarcoma of lateral abdominal wall (case report)].

    PubMed

    Akfirat, Murat; Kayaoğlu, Hüseyin Ayhan

    2004-12-01

    Mesenchymal chondrosarcomas are very rare in comparison to the conventional types. They can occur from any location containing mesenchymal cells, but most arise in the lower extremities, leptomeninges and in the orbits. Other sites are very uncommon. We present a case of mesenchymal chondrosarcoma of the lateral abdominal wall, and this is the first report of the tumor localized in this region. PMID:15611919

  6. Low-frequency fluid waves in fractures and pipes

    SciTech Connect

    Korneev, Valeri

    2010-09-01

    Low-frequency analytical solutions have been obtained for phase velocities of symmetrical fluid waves within both an infinite fracture and a pipe filled with a viscous fluid. Three different fluid wave regimes can exist in such objects, depending on the various combinations of parameters, such as fluid density, fluid viscosity, walls shear modulus, channel thickness, and frequency. Equations for velocities of all these regimes have explicit forms and are verified by comparisons with the exact solutions. The dominant role of fractures in rock permeability at field scales and the strong amplitude and frequency effects of Stoneley guided waves suggest the importance of including these wave effects into poroelastic theories.

  7. Fracture-network 3D characterization in a deformed chalk reservoir analogue -- the Laegerdorf case

    SciTech Connect

    Koestler, A.G.; Reksten, K.

    1995-09-01

    Quantitative descriptions of 3D fracture networks in terms of fracture characteristics and connectivity are necessary for reservoir evaluation, management, and EOR programs of fractured reservoirs. The author`s research has focused on an analogue to North Sea fractured chalk reservoirs that is excellently exposed near Laegerdorf, northwest Germany. An underlying salt diapir uplifted and deformed Upper Cretaceous chalk; the cement industry now exploits it. The fracture network in the production wall of the quarry was characterized and mapped at different scales, and 12 profiles of the 230-m wide and 35-m high production wall were investigated as the wall receded 25 m. In addition, three wells were drilled into the chalk volume. The wells were cored and the wellbores were imaged with both the resistivity formation micro scanner (FMS) and the sonic circumferential borehole image logger (CBIL). The large amount of fracture data was analyzed with respect to parameters, such as fracture density distribution, orientation, and length distribution, and in terms of the representativity and predictability of data sets collected from restricted rock volumes.

  8. Mars Geoscience Orbiter and Lunar Geoscience Orbiter

    NASA Technical Reports Server (NTRS)

    Fuldner, W. V.; Kaskiewicz, P. F.

    1983-01-01

    The feasibility of using the AE/DE Earth orbiting spacecraft design for the LGO and/or MGO missions was determined. Configurations were developed and subsystems analysis was carried out to optimize the suitability of the spacecraft to the missions. The primary conclusion is that the basic AE/DE spacecraft can readily be applied to the LGO mission with relatively minor, low risk modifications. The MGO mission poses a somewhat more complex problem, primarily due to the overall maneuvering hydrazine budget and power requirements of the sensors and their desired duty cycle. These considerations dictate a modification (scaling up) of the structure to support mission requirements.

  9. Wall Finishes; Carpentry: 901895.

    ERIC Educational Resources Information Center

    Dade County Public Schools, Miami, FL.

    The course outline is designed to provide instruction in selecting, preparing, and installing wall finishing materials. Prerequisites for the course include mastery of building construction plans, foundations and walls, and basic mathematics. Intended for use in grades 11 and 12, the course contains five blocks of study totaling 135 hours of…

  10. Thin Wall Iron Castings

    SciTech Connect

    J.F. Cuttino; D.M. Stefanescu; T.S. Piwonka

    2001-10-31

    Results of an investigation made to develop methods of making iron castings having wall thicknesses as small as 2.5 mm in green sand molds are presented. It was found that thin wall ductile and compacted graphite iron castings can be made and have properties consistent with heavier castings. Green sand molding variables that affect casting dimensions were also identified.

  11. 'Stucco' Walls-2

    NASA Technical Reports Server (NTRS)

    2004-01-01

    This image, taken by the microscopic imager, an instrument located on the Mars Exploration Rover Opportunity 's instrument deployment device, or 'arm,' shows the partial 'clodding' or cementation of the sand-sized grains within the trench wall. The area in this image measures approximately 3 centimeters (1.2 inches) across and makes up half of the projected 'Stucco Walls' image.

  12. Interactive Word Walls

    ERIC Educational Resources Information Center

    Jackson, Julie; Narvaez, Rose

    2013-01-01

    It is common to see word walls displaying the vocabulary that students have learned in class. Word walls serve as visual scaffolds and are a classroom strategy used to reinforce reading and language arts instruction. Research shows a strong relationship between student word knowledge and academic achievement (Stahl and Fairbanks 1986). As a…

  13. Domain wall filters

    SciTech Connect

    Baer, Oliver; Narayanan, Rajamani; Neuberger, Herbert; Witzel, Oliver

    2007-03-15

    We propose using the extra dimension separating the domain walls carrying lattice quarks of opposite handedness to gradually filter out the ultraviolet fluctuations of the gauge fields that are felt by the fermionic excitations living in the bulk. This generalization of the homogeneous domain wall construction has some theoretical features that seem nontrivial.

  14. Particle Swarms in Fractures: Open Versus Partially Closed Systems

    NASA Astrophysics Data System (ADS)

    Boomsma, E.; Pyrak-Nolte, L. J.

    2014-12-01

    In the field, fractures may be isolated or connected to fluid reservoirs anywhere along the perimeter of a fracture. These boundaries affect fluid circulation, flow paths and communication with external reservoirs. The transport of drop like collections of colloidal-sized particles (particle swarms) in open and partially closed systems was studied. A uniform aperture synthetic fracture was constructed using two blocks (100 x 100 x 50 mm) of transparent acrylic placed parallel to each other. The fracture was fully submerged a tank filled with 100cSt silicone oil. Fracture apertures were varied from 5-80 mm. Partially closed systems were created by sealing the sides of the fracture with plastic film. The four boundary conditions study were: (Case 1) open, (Case 2) closed on the sides, (Case 3) closed on the bottom, and (Case 4) closed on both the sides and bottom of the fracture. A 15 μL dilute suspension of soda-lime glass particles in oil (2% by mass) were released into the fracture. Particle swarms were illuminated using a green (525 nm) LED array and imaged with a CCD camera. The presence of the additional boundaries modified the speed of the particle swarms (see figure). In Case 1, enhanced swarm transport was observed for a range of apertures, traveling faster than either very small or very large apertures. In Case 2, swarm velocities were enhanced over a larger range of fracture apertures than in any of the other cases. Case 3 shifted the enhanced transport regime to lower apertures and also reduced swarm speed when compared to Case 2. Finally, Case 4 eliminated the enhanced transport regime entirely. Communication between the fluid in the fracture and an external fluid reservoir resulted in enhanced swarm transport in Cases 1-3. The non-rigid nature of a swarm enables drag from the fracture walls to modify the swarm geometry. The particles composing a swarm reorganize in response to the fracture, elongating the swarm and maintaining its density. Unlike a

  15. Long-Term Results of Orbital Roof Repair with Titanium Mesh in a Case of Traumatic Intraorbital Encephalocele: A Case Report and Review of Literature.

    PubMed

    Arslan, Erhan; Arslan, Selçuk; Kalkısım, Selçuk; Arslan, Ahmet; Kuzeyli, Kayhan

    2016-09-01

    Orbital roof fractures associated with cranial and maxillofacial trauma are rarely encountered. Traumatic intraorbital encephaloceles due to orbital roof fractures developing in the early posttraumatic period are even rarer. A variety of materials, such as alloplastic implants or autogenous materials, have been used for the reconstruction of orbital roof, but data regarding the long-term results of these materials are very limited. We report a case of intraorbital encephalocele developing in the early posttraumatic period (2 days) in a child patient and the long-term results of titanium mesh used for the reconstruction of the orbital roof. The case is presented with a pertinent review of literature. PMID:27516843

  16. Treatment Options in Maxillofacial Fractures.

    PubMed

    Guerrissi, Jorge Orlando

    2016-07-01

    From 2000 to 2010, 720 patients with facial trauma were admitted in Plastic Surgery Service of Argerich Hospital, Buenos Aires, Argentina; 58 of them with panfacial fractures were included in this study. Height velocity impact is the principal etiology, and most concomitant extrafacial injuries are neurocranium and cervical spine. Common affected areas were orbits, nose, and malar-zygoma. The timing of the treatment was airway evaluation, control of bleeding and consciousness, treatment of associated injuries, and finally facial reconstruction. The applications of craniofacial surgical techniques complete facial treatment in only operatory time by means of standard approaches like coronal, subciliar palpebral, upper and lower vestibular. The treatment was exploration to open sky; reduction and fijation with titanium plates; replacement of comminuted bones with bone autografts harvested iliac crest, calvary, and costal bones. The results were classificated acceptables in 48 (85%) and not acceptables in 9 (15%) according to successful reconstruction of the both form and armony facial, persistent esthetic and functional sequels, and postoperative complications. Postoperative complications were detected in 18 patients. According to most authors the use of internal rigid fixation and bone autograf permits obtaining the best aesthetic and functional results decreasing complications and sequels. The recuperation of tridimensional aspect of the face and aesthetic and functional pretrauma state must be the goal standard. PMID:27391510

  17. The orbits in cancer imaging

    PubMed Central

    Chong, V F H

    2006-01-01

    Primary malignant lesions in the orbit are relatively uncommon. However, the orbits are frequently involved in haematogeneous metastasis or by direct extension from malignancies originating from the adjacent nasal cavity or paranasal sinuses. This paper focuses on the more commonly encountered primary orbital malignancies and the mapping of tumour spread into the orbits. PMID:17114076

  18. Elliptical Orbit Performance Computer Program

    NASA Technical Reports Server (NTRS)

    Myler, T.

    1984-01-01

    Elliptical Orbit Performance (ELOPE) computer program for analyzing orbital performance of space boosters uses orbit insertion data obtained from trajectory simulation to generate parametric data on apogee and perigee altitudes as function of payload data. Data used to generate presentation plots that display elliptical orbit performance capability of space booster.

  19. Maxillofacial fractures in the province of Latina, Lazio, Italy: review of 400 injuries and 83 cases.

    PubMed

    Arangio, Paolo; Vellone, Valentino; Torre, Umberto; Calafati, Vincenzo; Capriotti, Marco; Cascone, Piero

    2014-07-01

    A retrospective study was performed to assess maxillofacial fractures in patients treated at the public "S.M. Goretti Hospital" hospital from 2011 to 31/8/2012. Data were prospectively recorded including age and sex, cause and mechanisms of injury, soft tissue injuries, dentoalveolar trauma, facial bone fractures and type of treatment. The pre-surgical and post-surgical hospitalization days were also analysed. Causes were grouped into five categories: road traffic collision, sports accidents, occupational accidents, assaults and domestic accidents. The analyses involved descriptive statistics. Records from 83 patient sustaining 95 maxillofacial fractures were evaluated. The zygoma was the most fractured anatomical site in both males and females, accounting for 32% of injuries, followed by isolated fracture of the orbital floor (blow-out and blow-in) with 11%. The age group between 18 and 39 years showed the highest rate of incidence of maxillofacial fractures. Men were more involved than women in all cases with a male:female ratio of 5,4:1. Accidents were the most frequent cause of maxillofacial fractures in the age group between 18 and 39 years and interpersonal violence was the most frequent cause of maxillofacial fractures in the age group between 40 and 59 years. Facial fractures occurred primarily among men under 30 years of age, and the most common sites of fractures in the face were the mandible and the zygomatic complex. Road traffic collisions were the main aetiologic factor associated with maxillofacial trauma. PMID:24035287

  20. Fracture behavior across interfaces

    NASA Astrophysics Data System (ADS)

    Petrie, E. S.; Evans, J. P.; Jeppson, T. N.

    2011-12-01

    Faults and fracture networks at depth are important fluid pathways, especially in fine-grained, low permeability seal lithologies. Discontinues in sealing lithologies can create seal bypass systems, leading to the failure of CO2 geosequestration sites or hydrocarbon traps. We characterize the occurrence of and changes in discontinuity patterns and the associated changes in elastic moduli across sedimentologic interfaces to document the importance of these discontinuities for fluid management in the subsurface and potential for re-activation in high-pressure injection scenarios. We evaluate well-exposed, fine-grained, low-permeability Mesozoic and Paleozoic units that are seals of potential CO2 repositories on the Colorado Plateau and show evidence for open fractures and fluid flow in the subsurface. Field observations document changes in fracture distributions across lithologic boundaries allowing us to identify mechano-stratigraphic units and focus on the effect of lithologic interfaces on fracture distribution. An interface marks the boundary between facies in a seal and in this study the fractures are shown to deflect or arrest at the interface. In outcrop fracture intensity varies in from 1 to 18 fractures per meter and fracture apertures range from mm to cm. The mineralized fractures often have associated alteration halos along their boundaries; their general orientation follows that of discontinuities within the underlying reservoir facies or adjacent faults. The recognition of these changes in fracture distribution is important for forward modeling of fluid flow and risk management. Studying the occurrence of and changes in fracture patterns from outcrops and scaling it up for use in modeling at a field scale is difficult due to the lack of direct correlation between outcrop observations and subsurface data. Due to the size and amount of data needed to model fluid flow at the field scale the meso-scale (cm to m) variability of rock properties is often

  1. Orbital spacecraft resupply technology

    NASA Technical Reports Server (NTRS)

    Eberhardt, R. N.; Tracey, T. R.; Bailey, W. J.

    1986-01-01

    The resupplying of orbital spacecraft using the Space Shuttle, Orbital Maneuvering Vehicle, Orbital Transfer Vehicle or a depot supply at a Space Station is studied. The governing factor in fluid resupply designs is the system size with respect to fluid resupply quantities. Spacecraft propellant management for tankage via diaphragm or surface tension configurations is examined. The capabilities, operation, and application of adiabatic ullage compression, ullage exchange, vent/fill/repressurize, and drain/vent/no-vent fill/repressurize, which are proposed transfer methods for spacecraft utilizing tankage configurations, are described. Selection of the appropriate resupply method is dependent on the spacecraft design features. Hydrazine adiabatic compression/detonation, liquid-free vapor venting to prevent freezing, and a method for no-vent liquid filling are analyzed. Various procedures for accurate measurements of propellant mass in low gravity are evaluated; a system of flowmeters with a PVT system was selected as the pressurant solubility and quantity gaging technique. Monopropellant and bipropellant orbital spacecraft consumable resupply system tanks which resupply 3000 lb of hydrazine and 7000 lb of MMH/NTO to spacecraft on orbit are presented.

  2. Orbital Fluid Resupply Assessment

    NASA Technical Reports Server (NTRS)

    Eberhardt, Ralph N.

    1989-01-01

    Orbital fluid resupply can significantly increase the cost-effectiveness and operational flexibility of spacecraft, satellites, and orbiting platforms and observatories. Reusable tankers are currently being designed for transporting fluids to space. A number of options exist for transporting the fluids and propellant to the space-based user systems. The fluids can be transported to space either in the Shuttle cargo bay or using expendable launch vehicles (ELVs). Resupply can thus be accomplished either from the Shuttle bay, or the tanker can be removed from the Shuttle bay or launched on an ELV and attached to a carrier such as the Orbital Maneuvering Vehicle (OMV) or Orbital Transfer Vehicle (OTV) for transport to the user to be serviced. A third option involves locating the tanker at the space station or an unmanned platform as a quasi-permanent servicing facility or depot which returns to the ground for recycling once its tanks are depleted. Current modular tanker designs for monopropellants, bipropellants, and water for space station propulsion are discussed. Superfluid helium tankers are addressed, including trade-offs in tanker sizes, shapes to fit the range of ELVs currently available, and boil-off losses associated with longer-term (greater than 6-month) space-basing. It is concluded that the mixed fleet approach to on-orbit consumables resupply offers significant advantages to the overall logistics requirements.

  3. Chemical Signatures of and Precursors to Fractures Using Fluid Inclusion Stratigraphy

    SciTech Connect

    Lorie M. Dilley

    2011-03-30

    Enhanced Geothermal Systems (EGS) are designed to recover heat from the subsurface by mechanically creating fractures in subsurface rocks. Open or recently closed fractures would be more susceptible to enhancing the permeability of the system. Identifying dense fracture areas as well as large open fractures from small fracture systems will assist in fracture stimulation site selection. Geothermal systems are constantly generating fractures (Moore, Morrow et al. 1987), and fluids and gases passing through rocks in these systems leave small fluid and gas samples trapped in healed microfractures. These fluid inclusions are faithful records of pore fluid chemistry. Fluid inclusions trapped in minerals as the fractures heal are characteristic of the fluids that formed them, and this signature can be seen in fluid inclusion gas analysis. This report presents the results of the project to determine fracture locations by the chemical signatures from gas analysis of fluid inclusions. With this project we hope to test our assumptions that gas chemistry can distinguish if the fractures are open and bearing production fluids or represent prior active fractures and whether there are chemical signs of open fracture systems in the wall rock above the fracture. Fluid Inclusion Stratigraphy (FIS) is a method developed for the geothermal industry which applies the mass quantification of fluid inclusion gas data from drill cuttings and applying known gas ratios and compositions to determine depth profiles of fluid barriers in a modern geothermal system (Dilley, 2009; Dilley et al., 2005; Norman et al., 2005). Identifying key gas signatures associated with fractures for isolating geothermal fluid production is the latest advancement in the application of FIS to geothermal systems (Dilley and Norman, 2005; Dilley and Norman, 2007). Our hypothesis is that peaks in FIS data are related to location of fractures. Previous work (DOE Grant DE-FG36-06GO16057) has indicated differences in the

  4. Computed tomography of facial fractures.

    PubMed

    Furlow, Bryant

    2014-01-01

    Facial skeletal fractures are common, potentially serious, and frequently associated with other life-threatening conditions, such as traumatic brain injuries. Facial fractures can be simple or complex and sometimes involve serious complications. Computed tomography has revolutionized the rapid and precise assessment of craniofacial and neck fractures in patients with severe facial trauma. This article introduces readers to the epidemiology, skeletal anatomy and biomechanics, complications, and diagnostic imaging of facial fractures. In addition, this article describes efforts to develop and validate a quantitative scoring system for facial fracture severity and reviews treatment strategies for facial skeletal fractures. PMID:24806070

  5. Mars Telecommunications Orbiter, Artist's Concept

    NASA Technical Reports Server (NTRS)

    2005-01-01

    This illustration depicts a concept for NASA's Mars Telecommunications Orbiter in flight around Mars. The orbiter is in development to be the first spacecraft with a primary function of providing communication links while orbiting a foreign planet. The project's plans call for launch in September 2009, arrival at Mars in August 2010 and a mission of six to 10 years while in orbit. Mars Telecommunication Orbiter would serve as the Mars hub for an interplanetery Internet, greatly increasing the information payoff from other future Mars missions. The mission is designed to orbit Mars more than 10 times farther from the planet than orbiters dedicated primarily to science. The high-orbit design minimizes the time that Mars itself blocks the orbiter from communicating with Earth and maximizes the time that the orbiter is above the horizon -- thus capable of communications relay -- for rovers and stationary landers on Mars' surface.

  6. Major neurovascular complications of clavicle fracture surgery

    PubMed Central

    Clitherow, Harry DS

    2014-01-01

    Clavicle fracture fixation is becoming an increasingly common operation, with good clinical outcomes and a low rate of significant complications. However, there are several reports of rare but potentially life or limb threatening, neurovascular complications. Arterial injuries are usually pseudoaneurysms associated with prominent screws. These may be clinically silent for several years before presenting as subcritical upper limb ischaemia. Venous injuries are a result of tearing of the vessel wall by fracture manipulation, drills or implants. This produces intra-operative haemorrhage and potentially air embolism, which can be fatal if not rapidly recognized and managed. Brachial plexopathy is the result of traction on adherent plexus or impingement by fracture fragments or callus. It presents as severe arm pain and paralysis immediately postoperatively. Neurovascular injuries can be avoided by a combination of pre-operative planning, communication with anaesthetic staff and strategic surgical technique. The plane of the surgical exposure, release of the soft tissues, drill direction and depth and screw length are all important factors.

  7. 5. Detail of bin wall, showing the thinner exterior wall ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    5. Detail of bin wall, showing the thinner exterior wall next to the inner wall with its alternating courses of channel tile and hollow tile. - Saint Anthony Elevator No. 3, 620 Malcom Avenue, Southeast, Minneapolis, Hennepin County, MN

  8. 22. SIDE WALL CONSTRUCTION, NORTH TRAINING WALL, LOOKING WEST FROM ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    22. SIDE WALL CONSTRUCTION, NORTH TRAINING WALL, LOOKING WEST FROM THE SAME POINT AS VIEW NO. 21. - Oakland Harbor Training Walls, Mouth of Federal Channel to Inner Harbor, Oakland, Alameda County, CA

  9. Fracture-Flow-Enhanced Solute Diffusion into Fractured Rock

    SciTech Connect

    Wu, Yu-Shu; Ye, Ming; Sudicky, E.A.

    2007-12-15

    We propose a new conceptual model of fracture-flow-enhanced matrix diffusion, which correlates with fracture-flow velocity, i.e., matrix diffusion enhancement induced by rapid fluid flow within fractures. According to the boundary-layer or film theory, fracture flow enhanced matrix diffusion may dominate mass-transfer processes at fracture-matrix interfaces, because rapid flow along fractures results in large velocity and concentration gradients at and near fracture-matrix interfaces, enhancing matrix diffusion at matrix surfaces. In this paper, we present a new formulation of the conceptual model for enhanced fracture-matrix diffusion, and its implementation is discussed using existing analytical solutions and numerical models. In addition, we use the enhanced matrix diffusion concept to analyze laboratory experimental results from nonreactive and reactive tracer breakthrough tests, in an effort to validate the new conceptual model.

  10. The role of fracture coatings on water imbibition into unsaturated tuff from Yucca Mountain

    SciTech Connect

    Chekuri, V.S.; Tyler, S.W.; Fordham, J.W.

    1995-11-01

    Studies dealing with fracture flow at Yucca Mountain have generally assumed that any water flowing down in a fracture will be absorbed by the porous matrix. However, a thin lining of low permeability material on the fracture walls may significantly impede imbibition into the matrix of unsaturated tuff. In this research, imbibition was measured across the fracture surfaces in the laboratory. Samples were collected from surface outcrops of Tiva Canyon and Topopah Spring members of the Paintbrush tuff near Yucca Mountain. Sorptivity, a convenient measure of imbibition, was used to investigate the changes in hydraulic properties as a result of fracture coatings. Results from experimental analysis of Topopah Spring tuff showed decreased sorptivity across coated fracture surfaces. Statistically, the coatings on the Tiva Canyon samples do not significantly affect sorptivity. Scanning Electron Microscope analysis shows that coatings on the s grit Tiva Canyon samples are made up of iron, aluminum and to some extent magnesium. Coating material on the Topopah Spring samples is made up of calcium, magnesium, aluminum and iron. Coating significantly reduces the sorptivity for the Topopah Spring tuff. Numerical results are presented to show the effect of fracture coatings on water infiltration down a vertical fracture in simulated tuff. For the Topopah Spring tuff, the wetting front in the coated fracture travels deeper in the fracture and less into the matrix compared to the wetting front in the uncoated fracture. For the Tiva Canyon tuff, the wetting front in the uncoated fracture travels deeper in the fracture and less into the matrix as compared to the wetting front in the coated fracture.

  11. Toughness of carbon nanotubes conforms to classic fracture mechanics

    PubMed Central

    Yang, Lin; Greenfeld, Israel; Wagner, H. Daniel

    2016-01-01

    Defects in crystalline structure are commonly believed to degrade the ideal strength of carbon nanotubes. However, the fracture mechanisms induced by such defects, as well as the validity of solid mechanics theories at the nanoscale, are still under debate. We show that the fracture toughness of single-walled nanotubes (SWNTs) conforms to the classic theory of fracture mechanics, even for the smallest possible vacancy defect (~2 Å). By simulating tension of SWNTs containing common types of defects, we demonstrate how stress concentration at the defect boundary leads to brittle (unstable) fracturing at a relatively low strain, degrading the ideal strength of SWNTs by up to 60%. We find that, owing to the SWNT’s truss-like structure, defects at this scale are not sharp and stress concentrations are finite and low. Moreover, stress concentration, a geometric property at the macroscale, is interrelated with the SWNT fracture toughness, a material property. The resulting SWNT fracture toughness is 2.7 MPa m0.5, typical of moderately brittle materials and applicable also to graphene. PMID:26989774

  12. Flow dynamics and solute transport in unsaturated rock fractures

    SciTech Connect

    Su, G. W.

    1999-10-01

    Rock fractures play an important role in flow and contaminant transport in fractured aquifers, production of oil from petroleum reservoirs, and steam generation from geothermal reservoirs. In this dissertation, phenomenological aspects of flow in unsaturated fractures were studied in visualization experiments conducted on a transparent replica of a natural, rough-walled rock fracture for inlet conditions of constant pressure and flow rate over a range of angles of inclination. The experiments demonstrated that infiltrating liquid proceeds through unsaturated rock fractures along non-uniform, localized preferential flow paths. Even in the presence of constant boundary conditions, intermittent flow was a persistent flow feature observed, where portions of the flow channel underwent cycles of snapping and reforming. Two modes of intermittent flow were observed, the pulsating blob mode and the rivulet snapping mode. A conceptual model for the rivulet snapping mode was proposed and examined using idealized, variable-aperture fractures. The frequency of intermittent flow events was measured in several experiments and related to the capillary and Bond numbers to characterize this flow behavior.

  13. Toughness of carbon nanotubes conforms to classic fracture mechanics.

    PubMed

    Yang, Lin; Greenfeld, Israel; Wagner, H Daniel

    2016-02-01

    Defects in crystalline structure are commonly believed to degrade the ideal strength of carbon nanotubes. However, the fracture mechanisms induced by such defects, as well as the validity of solid mechanics theories at the nanoscale, are still under debate. We show that the fracture toughness of single-walled nanotubes (SWNTs) conforms to the classic theory of fracture mechanics, even for the smallest possible vacancy defect (~2 Å). By simulating tension of SWNTs containing common types of defects, we demonstrate how stress concentration at the defect boundary leads to brittle (unstable) fracturing at a relatively low strain, degrading the ideal strength of SWNTs by up to 60%. We find that, owing to the SWNT's truss-like structure, defects at this scale are not sharp and stress concentrations are finite and low. Moreover, stress concentration, a geometric property at the macroscale, is interrelated with the SWNT fracture toughness, a material property. The resulting SWNT fracture toughness is 2.7 MPa m(0.5), typical of moderately brittle materials and applicable also to graphene. PMID:26989774

  14. Slow Waves in Fractures Filled with Viscous Fluid

    SciTech Connect

    Korneev, Valeri

    2008-01-08

    Stoneley guided waves in a fluid-filled fracture generally have larger amplitudes than other waves, and therefore, their properties need to be incorporated in more realistic models. In this study, a fracture is modeled as an infinite layer of viscous fluid bounded by two elastic half-spaces with identical parameters. For small fracture thickness, I obtain a simple dispersion equation for wave-propagation velocity. This velocity is much smaller than the velocity of a fluid wave in a Biot-type solution, in which fracture walls are assumed to be rigid. At seismic prospecting frequencies and realistic fracture thicknesses, the Stoneley guided wave has wavelengths on the order of several meters and an attenuation Q factor exceeding 10, which indicates the possibility of resonance excitation in fluid-bearing rocks. The velocity and attenuation of Stoneley guided waves are distinctly different at low frequencies for water and oil. The predominant role of fractures in fluid flow at field scales is supported by permeability data showing an increase of several orders of magnitude when compared to values obtained at laboratory scales. These data suggest that Stoneley guided waves should be taken into account in theories describing seismic wave propagation in fluid-saturated rocks.

  15. Orbital motions of bubbles in an acoustic field

    NASA Astrophysics Data System (ADS)

    Shirota, Minori; Yamashita, Ko; Inamura, Takao

    2012-09-01

    This experimental study aims to clarify the mechanism of orbital motion of two oscillating bubbles in an acoustic field. Trajectory of the orbital motion on the wall of a spherical levitator was observed using a high-speed video camera. Because of a good repeatability in volume oscillation of bubbles, we were also able to observe the radial motion driven at 24 kHz by stroboscopic like imaging technique. The orbital motions of bubbles raging from 0.13 to 0.18 mm were examined with different forcing amplitude and in different viscous oils. As a result, we found that pairs of bubbles revolve along an elliptic orbit around the center of mass of the bubbles. We also found that the two bubbles perform anti-phase radial oscillation. Although this radial oscillation should result in a repulsive secondary Bjerknes force, the bubbles kept a constant separate distance of about 1 mm, which indicates the existence of centripetal primary Bjerknes force.

  16. Deceleration Orbit Improvements

    SciTech Connect

    Church, M.

    1991-04-26

    During the accelerator studies period of 12/90-1/91 much study time was dedicated to improving the E760 deceleration ramps. 4 general goals were in mind: (1) Reduce the relative orbit deviations from the nominal reference orbit as much as possible. This reduces the potential error in the orbit length calculation - which is the primary source of error in the beam energy calculation. (2) Maximize the transverse apertures. This minimizes beam loss during deceleration and during accidental beam blow-ups. (3) Measure and correct lattice parameters. Knowledge of {gamma}{sub T}, {eta}, Q{sub h}, Q{sub v}, and the dispersion in the straight sections allows for a more accurate energy calculation and reliable SYNCH calculations. (4) Minimize the coupling. This allows one to discern between horizontal and vertical tunes.

  17. Misdiagnosis of Talar Body or Neck Fractures as Ankle Sprains in Low Energy Traumas

    PubMed Central

    Young, Ki-Won; Kim, Jin-Su; Cho, Hun-Ki; Choo, Ho-Sik; Park, Jang-Ho

    2016-01-01

    Background The talus has a very complex anatomical morphology and is mainly fractured by a major force caused by a fall or a traffic accident. Therefore, a talus fracture is not common. However, many recent reports have shown that minor injuries, such as sprains and slips during sports activities, can induce a talar fracture especially in the lateral or posterior process. Still, fractures to the main parts of the talus (neck and body) after ankle sprains have not been reported as occult fractures. Methods Of the total 102 cases from January 2005 to December 2012, 7 patients had confirmed cases of missed/delayed diagnosis of a talus body or neck fracture and were included in the study population. If available, medical records, X-rays, computed tomography scans, and magnetic resonance imaging of the confirmed cases were retrospectively reviewed and analyzed. Results In the 7-patient population, there were 3 talar neck fractures and 4 talar body fractures (coronal shearing type). The mechanisms of injuries were all low energy trauma episodes. The causes of the injuries included twisting of the ankle during climbing (n = 2), jumping to the ground from a 1-m high wall (n = 2), and twisting of the ankle during daily activities (n = 3). Conclusions A talar body fracture and a talar neck fracture should be considered in the differential diagnosis of patients with acute and chronic ankle pain after a minor ankle injury. PMID:27583114

  18. Surface Roughness Effects on Fluid Transport Through a Natural Rock Fracture

    SciTech Connect

    Crandall, D.M.; Ahmadi, Goodarz; Smith, D.H.

    2008-04-01

    Fluid flow through rock fractures can be orders of magnitude faster than through the adjacent low-permeability rock. Understanding how fluid moves through these pathways is important for the prediction of sequestered CO2 transport in geologic reservoirs. Reservoir-scale, discrete-fracture simulators use simplified models of flow through fractures to determine transport properties in complex fracture networks. A high level of approximation is required in these reservoir-scale simulations due to the number of fractures within the domain of interest and because of the limited amount of information that can be obtained from geophysical well-logs (Long et al. (1996)). For this study, flow simulations through a CT-scanned fracture were performed to evaluate different fluid transport parameters that are important in geological flow analysis. The ‘roughness’ of the fracture was varied to determine the effect of the bumpy fracture walls on the fluid flow. The permeability and effective aperture were determined for flow under a constant pressure head. The fracture roughness is shown to dramatically reduce the flow through the fracture, and various relations are described.

  19. TIBIAL PLATEAU FRACTURES

    PubMed Central

    Júnior, Mauricio Kfuri; Fogagnolo, Fabrício; Bitar, Rogério Carneiro; Freitas, Rafael Lara; Salim, Rodrigo; Jansen Paccola, Cleber Antonio

    2015-01-01

    Tibial plateau fractures are joint lesions that require anatomical reduction of joint surface and functional restoration of mechanical axis of a lower limb. Patient profile, soft tissue conditions, presence of associated injuries and the available infrastructure for the treatment all contribute to the decision making about the best treatment for these fractures. High-energy fractures are usually approached in a staged manner respecting the principle of damage control, and are primarily targeted to maintain limb alignment while the resolution unfavorable soft tissue conditions is pending. Low-energy trauma can be managed on a singlestage basis, provided soft tissues are not an adverse factor, with open reduction and internal fixation. Stable fixation and early painless joint movement are related to a better prognosis. New developments as locked plates, bone replacements, intraoperative 3D imaging are promising and will certainly contribute for less invasive procedures and better outcomes. PMID:27077054

  20. Talar neck fractures.

    PubMed

    Berlet, G C; Lee, T H; Massa, E G

    2001-01-01

    Clinical management of talar neck fractures is complex and fraught with complications. As Gaius Julius Caesar stated: "The die is cast"; often the outcome of a talar neck fracture is determined at the time of injury. The authors believe, however, that better results can be achieved by following some simple guidelines. The authors advocate prompt and precise anatomic surgical reduction, preferring the medial approach with secondary anterolateral approach. Preservation of blood supply can be achieved by a thorough understanding of vascular pathways and efforts to stay within appropriate surgical intervals. The authors advocate bone grafting of medial neck comminution (if present) to prevent varus malalignment and rigid internal fixation to allow for joint mobilization postoperatively. These guidelines may seem simple, but when dealing with the complexity of talar neck fractures, the foot and ankle surgeon needs to focus and rely on easily grasped concepts to reduce poor outcomes. PMID:11465133