Sample records for prevent cage subsidence

  1. [The clinical value of end plate rings in preventing subsidence of titanium cage in anterior cervical corpectomy and fusion surgery]. (United States)

    He, Lei; Qian, Yu; Jin, Yi-Jun; Fan, Liang; Lü, Zuo


    To evaluate the clinical results of using end plate rings in preventing subsidence of titanium cage in anterior cervical corpectomy and fusion (ACCF) surgery. The clinical data of 71 patients with cervical spondylotic myelopathy underwent ACCF in single segment from February 2008 to February 2011 were retrospectively analyzed. There were 38 males and 33 females, aged from 39 to 74 years old with a mean of 53.8 years. Thirty-three were used end plate rings and thirty-eight were not used (end plate rings group and no end plate ring group, respectively). The Japanese Orthopaedic Association (JOA) score, Odom's scale, imaging data were used to evaluate the clinical effects. Imaging data including Cobb angle of fusion segment, intervertebral height of anterior border (Da) and posterior border (Dp), the mean intervertebral height (Dm). All patients were followed up from 13 to 34 months with an average of 19.5 months. Between two groups, there was no significant difference in Cobb angle of fusion segment and the mean intervertebral height (Dm) before surgery and one week after surgery. Whereas, one year after surgery, the Cobb angle of end plate ring group was (9.4 ± 3.8) degrees, and contral group was (7.5 ± 3.9) degrees, which was significantly lower than that of end plate ring group. Meanwhile, the Dm of end plate ring group was (57.3 ± 2.2) mm, and no end ring group was (55.2 ± 2.6) mm which was significantly lower than that of end plate ring group. The subsidence in end plate ring group was 57.6%, and was 78.9% in no end plate ring group. There was no significant difference in JOA score before and after surgery between two groups. At 1 year after operation, 90.9% (30/33) got excellent or good results in end plate ring group, 89.5% (33/38) got excellent or good results in contral group. The use of end plate rings could not completely prevent the subsidence of titanium cage, however, which can decrease the occurrence rate of the subsidence and lessen its degree.

  2. The Effect of Cervical Interbody Cage Morphology, Material Composition, and Substrate Density on Cage Subsidence. (United States)

    Suh, Paul B; Puttlitz, Christian; Lewis, Chad; Bal, B Sonny; McGilvray, Kirk


    Interbody cages used in spinal fusion surgery can subside into the adjacent vertebral bodies after implantation, leading to loss of spinal height, malalignment, and possible radicular symptoms. Several factors may contribute to cage subsidence. This in vitro investigation examined the possible contribution of substrate density, cage contact area (ie, cage footprint), cage filling, cage end plate surface texture, and cage material composition on the magnitude of subsidence. Commercially available cervical interbody cages of two sizes (16 × 12 mm and 17 × 14 mm) were implanted between foam blocks of two different densities and were cyclically loaded. Cages were made of titanium alloy (Ti4Al6V), silicon nitride ceramic (Si3N4), or polyether ether ketone (n = 8 cages of each material type). Additional testing was performed on Si3N4 cages of the smaller size with nontextured surfaces and with filled cores. Subsidence measurements showed that lower foam density had the greatest influence on subsidence, followed by smaller cage footprint. Cage material had no effect on subsidence. In the additional testing of small-footprint Si3N4 cages, the cages in which the core was filled with a load-bearing porous material had less subsidence in lower-density foam than the cages with an empty core had, whereas cage end plate surface texture had no effect on subsidence. Ranking of the relative impact of these factors indicated that substrate density had the greatest contribution to the measured subsidence (approximately 1.7 times and approximately 67 times greater than the contributions of cage footprint area and material, respectively). The contribution of cage footprint area to subsidence was found to be 40 times greater than the contribution of cage material to subsidence.

  3. Cage subsidence after anterior cervical discectomy and fusion using a cage alone or combined with anterior plate fixation. (United States)

    Pinder, E M; Sharp, D J


    To compare the extent of cage subsidence after anterior cervical discectomy and fusion (ACDF) using a cage alone or combined with anterior plate fixation, and to assess the effect of end plate removal on cage subsidence. Records of 23 men and 13 women aged 32 to 82 (mean, 54) years who underwent ACDF for 61 levels using the Solis cage alone (n=46) or combined with anterior plate fixation (n=15) were reviewed. The extent of cage subsidence was determined by comparing immediately postoperative (within one week) with final follow-up radiographs. Cage subsidence was defined as the sum subsidence of the superior and inferior part of the cage into the vertebral body. Mild and major cage subsidence was defined as ≤2 mm and >2 mm, respectively. Patients who underwent ACDF using a cage alone or combined with anterior plate fixation were comparable in terms of age, gender, follow-up duration, and number of levels decompressed. Cage subsidence occurred in 33 (54%) of the 61 levels decompressed. In the cage alone group, the extent of cage subsidence was greater (1.68 vs. 0.57 mm, p=0.039) and the rate of major cage subsidence was higher (28% vs. 7%, p=0.08). The inferior part of the cage was more vulnerable to subsidence compared with the superior part (median subsidence: 3.0 vs. 1.4 mm, psubsidence occurred more often when the end plate was removed rather than preserved (58% vs. 18%, psubsidence was greater after ACDF with cage alone. Cage subsidence occurred more often when the end plate was removed. Additional anterior plate fixation is recommended when the end plate is removed.

  4. Radiological outcomes of static vs expandable titanium cages after corpectomy: a retrospective cohort analysis of subsidence. (United States)

    Lau, Darryl; Song, Yeohan; Guan, Zhe; La Marca, Frank; Park, Paul


    Mesh cages have commonly been used for reconstruction after corpectomy. Recently, expandable cages have become a popular alternative. Regardless of cage type, subsidence is a concern following cage placement. To assess whether subsidence rates differ between static and expandable cages, and identify independent risk factors for subsidence and extent of subsidence when present. A consecutive population of patients who underwent corpectomy between 2006 and 2009 was identified. Subsidence was assessed via x-ray at 1-month and 1-year follow-ups. In addition to cage type, demographic, medical, and cage-related covariates were recorded. Multivariate models were used to assess independent associations with rate, odds, and extent of subsidence. Of 91 patients, 44.0% had expandable cages and 56.0% had static cages. One-month subsidence rate was 36.3%, and the 1-year subsidence rate was 51.6%. Expandable cages were independently associated with higher rates and odds of subsidence in comparison with static cages. Infection, trauma, and footplate-to-vertebral body endplate ratio of less than 0.5 were independent risk factors for subsidence. The presence of prongs on cages and posterior fusion 2 or more levels above and below corpectomy level had lower rates and odds of subsidence. Infection and cage placement in the thoracic or lumbar region had greater extent of subsidence when subsidence was present. Expandable cages had higher rates and risk of subsidence in comparison with static cages. When subsidence was present, expandable cages had greater magnitudes of subsidence. Other factors including footplate-to-vertebral body endplate ratio, prongs, extent of supplemental posterior fusion, spinal region, and diagnosis also impacted subsidence.

  5. Corpectomy cage subsidence with rectangular versus round endcaps. (United States)

    Deukmedjian, Armen R; Manwaring, Jotham; Le, Tien V; Turner, Alexander W L; Uribe, Juan S


    Corpectomy cages with rectangular endcaps utilize the stronger peripheral part of the endplate, potentially decreasing subsidence risk. The authors evaluated cage subsidence during cyclic biomechanical testing, comparing rectangular versus round endcaps. Fourteen cadaveric spinal segments (T12-L2) were dissected and potted at T12 and L2, then assigned to a rectangular (n=7) or round (n=7) endcap group. An L1 corpectomy was performed and under uniform conditions a cage/plate construct was cyclically tested in a servo-hydraulic frame with increasing load magnitude. Testing was terminated if the test machine actuator displacement exceeded 6mm, or the specimen completed cyclic loading at 2400 N. Number of cycles, compressive force and force-cycles product at test completion were all greater in the rectangular endcap group compared with the round endcap group (cycles: 3027 versus 2092 cycles; force: 1943 N versus 1533 N; force-cycles product: 6162kN·cycles versus 3973 kN·cycles), however these differences were not statistically significant (p ⩾ 0.076). After normalizing for individual specimen bone mineral density, the same measures increased to a greater extent with the rectangular endcaps (cycles: 3014 versus 1855 cycles; force: 1944 N versus 1444 N; force-cycles product: 6040 kN·cycles versus 2980 kN·cycles), and all differences were significant (p⩽0.030). The rectangular endcap expandable corpectomy cage displayed increased resistance to subsidence over the round endcap cage under cyclic loading as demonstrated by the larger number of cycles, maximum load and force-cycles product at test completion. This suggests rectangular endcaps will be less susceptible to subsidence than the round endcap design. Copyright © 2014 Elsevier Ltd. All rights reserved.

  6. Subsidence of polyetheretherketone cage after minimally invasive transforaminal lumbar interbody fusion. (United States)

    Kim, Moon-Chan; Chung, Hung-Tae; Cho, Jae-Lim; Kim, Dong-Jun; Chung, Nam-Su


    A retrospective case series. The aim of this study was to determine the rate of cage subsidence after minimally invasive transforaminal lumbar interbody fusion (MITLIF) conducted using a polyetheretherketone (PEEK) cage, and to identify associated risk factors. Although various rates of cage subsidence after lumbar interbody fusion have been reported, few studies have addressed subsidence rate after MITLIF using PEEK cage. A total of 104 consecutive patients who had undergone MITLIF using a PEEK cage with a minimum follow-up of 2 years were included in this study. Cage subsidence was defined to have occurred when a cage was observed to sink into an adjacent vertebral body by ≥2 mm on the postoperative or serial follow-up lateral radiographs. The demographic variables considered to affect cage subsidence were the following: age, sex, body mass index, bone mineral density, diagnosis, number of fusion segment, and the quality/quantity of back muscle, and the cage-related variables considered were: level of fusion, intervertebral angle, cage size, cage position, and postoperative distraction of disc height. Logistic regression analysis was conducted to explore relations between these variables and cage subsidence. : For the 122 cages inserted, the rate of cage subsidence was 14.8% (18 cages), and cage subsidence occurred within 7.2±8.5 (1-25) months of surgery. The odds ratios for factors found to significantly increase the risk of cage subsidence were; 1.950 (95% confidence interval, 1.002-4.224) for L5-S1 level, and 1.018 (95% confidence interval, 1.000-1.066) for anterior cage position. The rate of PEEK cage subsidence after MITLIF was relatively low. End-plate manipulation and cage insertion during MITLIF were not influenced by a small operation window.

  7. Incidence and clinical relevance of cage subsidence in anterior cervical discectomy and fusion: a systematic review. (United States)

    Noordhoek, Iris; Koning, Marvyn T; Jacobs, Wilco C H; Vleggeert-Lankamp, Carmen L A


    The placement of intervertebral cages in anterior cervical discectomy (ACDF) supposedly maintains foraminal height. The most commonly reported cage-related complication is subsidence, although it is unknown whether a correlation between subsidence and clinical outcome exists. To assess the incidence and relevance of subsidence. Literature searches were performed in PubMed, MEDLINE, Embase, Web of Science, COCHRANE, and CENTRAL. The inclusion criteria were as follows: ≥ 20 patients, ADCF with cage, subsidence assessed, and primary data. Risk of bias was assessed using adjusted Cochrane checklists. Seventy-one studies, comprising 4784 patients, were included. Subsidence was generally defined as ≥ 3-mm loss of height comparing postoperative intervertebral heights with heights at last follow-up. Mean incidence of subsidence was 21% (range 0-83%). Of all patients, 46% of patients received polyether-ether-ketone (PEEK) cages, 31% received titanium cages, 18% received cage-screw-combinations, and 5% received polymethyl-methacrylate (PMMA) cages. Patients treated with cage-screw-combinations had significantly less subsidence than patients treated with PEEK, titanium, or PMMA cages (15.1% vs. 23.5% vs. 24.9% vs. 30.2%; p subsidence; the majority did not find a significant correlation. Only four studies correlated subsidence to cage size and/or height; no correlation was established. Subsidence in ACDF with cages occurs in 21% of patients. The risk for subsidence seems lower using PEEK or titanium cages or adding screws. Whether subsidence affects clinical outcome is not satisfactorily evaluated in the available literature. Future studies on this correlation are warranted in order to establish the additional value of the interposition of a cage in ACDF.

  8. Subsidence and nonunion after anterior cervical interbody fusion using a stand-alone polyetheretherketone (PEEK) cage. (United States)

    Yang, Jae Jun; Yu, Chang Hun; Chang, Bong-Soon; Yeom, Jin Sup; Lee, Jae Hyup; Lee, Choon-Ki


    The purposes of the present study are to evaluate the subsidence and nonunion that occurred after anterior cervical discectomy and fusion using a stand-alone intervertebral cage and to analyze the risk factors for the complications. Thirty-eight patients (47 segments) who underwent anterior cervical fusion using a stand-alone polyetheretherketone (PEEK) cage and an autologous cancellous iliac bone graft from June 2003 to August 2008 were enrolled in this study. The anterior and posterior segmental heights and the distance from the anterior edge of the upper vertebra to the anterior margin of the cage were measured on the plain radiographs. Subsidence was defined as ≥ a 2 mm (minor) or 3 mm (major) decrease of the segmental height at the final follow-up compared to that measured at the immediate postoperative period. Nonunion was evaluated according to the instability being ≥ 2 mm in the interspinous distance on the flexion-extension lateral radiographs. The anterior and posterior segmental heights decreased from the immediate postoperative period to the final follow-up at 1.33 ± 1.46 mm and 0.81 ± 1.27 mm, respectively. Subsidence ≥ 2 mm and 3 mm were observed in 12 segments (25.5%) and 7 segments (14.9%), respectively. Among the expected risk factors for subsidence, a smaller anteroposterior (AP) diameter (14 mm vs. 12 mm) of cages (p = 0.034; odds ratio [OR], 0.017) and larger intraoperative distraction (p = 0.041; OR, 3.988) had a significantly higher risk of subsidence. Intervertebral nonunion was observed in 7 segments (7/47, 14.9%). Compared with the union group, the nonunion group had a significantly higher ratio of two-level fusion to one-level fusions (p = 0.001). Anterior cervical fusion using a stand-alone cage with a large AP diameter while preventing anterior intraoperative over-distraction will be helpful to prevent the subsidence of cages. Two-level cervical fusion might require more careful attention for avoiding nonunion.

  9. Subsidence of Cylindrical Cage (AMSLU™ Cage) : Postoperative 1 Year Follow-up of the Cervical Anterior Interbody Fusion (United States)

    Joung, Young Il; Ko, Yong; Yi, Hyeong Joong; Lee, Seung Ku


    Objective There are numerous reports on the primary stabilizing effects of the different cervical cages for cervical radiculopathy. But, little is known about the subsidence which may be clinical problem postoperatively. The goal of this study is to evaluate subsidence of cage and investigate the correlation between radiologic subsidence and clinical outcome. Methods To assess possible subsidence, the authors investigated clinical and radiological results of the one-hundred patients who underwent anterior cervical fusion by using AMSLU™ cage during the period between January 2003 and June 2005. Preoperative and postoperative lateral radiographs were measured for height of intervertebral disc space where cages were placed. Intervertebral disc space was measured by dividing the sum of anterior, posterior, and midpoint interbody distance by 3. Follow-up time was 6 to 12 months. Subsidence was defined as any change in at least one of our parameters of at least 3 mm. Results Subsidence was found in 22 patients (22%). The mean value of subsidence was 2.21 mm, and mean subsidence rate was 22%. There were no cases of the clinical status deterioration during the follow-up period. No posterior or anterior migration was observed. Conclusion The phenomenon of subsidence is seen in substantial number of patients. Nevertheless, clinical and radiological results of the surgery were favorable. An excessive subsidence may result in hardware failure. Endplate preservation may enables us to control subsidence and reduce the number of complications. PMID:19096571

  10. Complete cage migration/subsidence into the adjacent vertebral body after posterior lumbar interbody fusion. (United States)

    Corniola, Marco V; Jägersberg, Max; Stienen, Martin N; Gautschi, Oliver P


    A variety of implant-related short and long-term complications after lumbar fusion surgery are recognized. Mid to long-term complications due to cage migration and/or cage subsidence are less frequently reported. Here, we report a patient with a complete cage migration into the superior adjacent vertebral body almost 20 years after the initial posterior lumbar interbody fusion procedure. In this patient, the cage migration/subsidence was clinically silent, but a selective decompression for adjacent segment degenerative lumbar spinal stenosis was performed. We discuss the risk factors for cage migration/subsidence in view of the current literature. Copyright © 2014 Elsevier Ltd. All rights reserved.

  11. Graft Subsidence and Revision Rates Following Anterior Cervical Corpectomy: A Clinical Study Comparing Different Interbody Cages. (United States)

    Weber, Michael H; Fortin, Maryse; Shen, Jian; Tay, Bobby; Hu, Serena S; Berven, Sigurd; Burch, Shane; Chou, Dean; Ames, Christopher; Deviren, Vedat


    Retrospective cohort study. To assess the subsidence and revision rates associated with different interbody cages following anterior cervical corpectomy and reconstruction. Different interbody cages are currently used for surgical reconstruction of the anterior and middle columns of the spine following anterior cervical corpectomy. However, subsidence and delayed union/nonunion associated with allograft and cage reconstruction are common complications, which may require revision with instrumentation. We reviewed the cases of 75 patients who underwent cervical corpectomy and compared the radiographic graft subsidence and revision rates for fibula allograft, titanium mesh cage, titanium expandable cage, and carbon fiber cages. Subsidence was calculated by comparing the immediate postoperative lateral x-ray films to those obtained during follow-up visits. The average graft subsidence was 3 mm and revision rate was 25% for fibula allograft versus 2.9 mm and 11.1%, 2.9 mm and 18.8% for titanium mesh cages and titanium expandable cages, respectively. The average graft subsidence for carbon fiber cages was 0.7 mm with no revision surgery in this subset. Our findings suggest that subsidence and revision rates following anterior corpectomy and interbody fusion could be minimized with the use of a carbon fiber cage.

  12. Subsidence of polyetheretherketone intervertebral cages in minimally invasive lateral retroperitoneal transpsoas lumbar interbody fusion. (United States)

    Le, Tien V; Baaj, Ali A; Dakwar, Elias; Burkett, Clinton J; Murray, Gisela; Smith, Donald A; Uribe, Juan S


    A retrospective review. The objective is to evaluate subsidence related to minimally invasive lateral retroperitoneal lumbar interbody fusion by reviewing our experience with this procedure. Polyetheretherketone intervertebral cages of different lengths, widths, and heights filled with various allograft types are commonly used as spacers in lumbar fusions. Subsidence is a potential complication. To date, there are no published reports specifically addressing subsidence, because it relates to a series of patients undergoing minimally invasive lateral retroperitoneal transpsoas lumbar interbody fusion. An institutional review board-approved, retrospective review of a prospectively collected database was conducted. One hundred forty consecutive patients who underwent this procedure between L1 and L5 during a 2-year period were included. All patients had T scores of -2.5 or more. Postoperative radiographs during routine follow-ups were reviewed for subsidence, defined as any violation of the vertebral end plate. Radiographical subsidence occurred in 14.3% (20 of 140), whereas clinical subsidence occurred in 2.1%. Subsidence occurred in 8.8% (21 of 238) of levels fused. Construct length had a significant positive correlation with increasing subsidence rates. Subsidence rates decreased progressively with lower levels in the lumbar spine, but had a higher than expected rate at L4-L5. Subsidence rates of 14.1% (19 of 135) and 1.9% (2 of 103) were associated with 18-and 22-mm-wide cages, respectively. No significant trends were observed with cage lengths. Supplemental lateral plates had a higher rate of subsidence than bilateral pedicle screws. Subsidence occurred at the superior end plate 70% of the time. The use of wider intervertebral cages leads to a significantly lower rate of subsidence, but a longer cage does not necessarily offer a similar advantage. Wide cages are protective against subsidence, and the widest cages should be used whenever feasible for interbody

  13. Subsidence after single-level anterior cervical fusion with a stand-alone cage. (United States)

    Park, Jae-Young; Choi, Ki-Young; Moon, Bong Ju; Hur, Hyuk; Jang, Jae-Won; Lee, Jung-Kil


    To investigate the risk factors for subsidence in patients treated with stand-alone anterior cervical discectomy and fusion (ACDF) using polyetheretherketone (PEEK) cages for single-level degenerative cervical disease. Seventy-seven consecutive patients who underwent single-level stand-alone ACDF with a PEEK cage between 2005 and 2012 were included. Subsidence was defined as a decrease in the interbody height of more than 3mm on radiographs at the 1-year follow-up compared with that in the immediate post-operative image. Patients were divided into the subsidence and non-subsidence groups. The following factors were investigated in relation to the occurrence of subsidence: age, pre-operative overall cervical sagittal angle, segmental angle of the operated level, interbody height, cage height, cage devices and cage location (distance between anterior margin of the body endplate and that of the cage). The clinical outcomes were assessed with visual analog scale, modified Japanese Orthopedic Association score and neck disability index. Twenty-six out of the 77 (33.8%) patients had radiological signs of cage subsidence. Solid fusion was achieved in 25 out of the 26 patients (96.2%) in the subsidence group and in 47 out of the 51 patients (92.2%) in the non-subsidence group. More than 3mm distance between anterior margin of the vertebral body and that of the cage was significantly associated with subsidence (psubsidence did not correlate with fusion rate or clinical outcomes. Cage location was the only significant risk factor. Therefore, cage location should be taken into consideration during stand-alone ACDF using PEEK cages. Copyright © 2016 Elsevier Ltd. All rights reserved.

  14. Elimination of Subsidence with 26-mm-Wide Cages in Extreme Lateral Interbody Fusion. (United States)

    Lang, Gernot; Navarro-Ramirez, Rodrigo; Gandevia, Lena; Hussain, Ibrahim; Nakhla, Jonathan; Zubkov, Micaella; Härtl, Roger


    Extreme lateral interbody fusion (ELIF) has gained popularity as a minimally invasive technique for indirect decompression. However, graft subsidence potentially threatens long-term success of ELIF. This study evaluated whether 26-mm-wide cages can eliminate subsidence and subsequent loss of decompression in ELIF. Patients undergoing ELIF surgery using a 26-mm-wide cage were analyzed retrospectively. Patient demographics and perioperative data for radiographic and clinical outcomes were recorded. Radiographic parameters included regional sagittal lumbar lordosis and foraminal and disc height. Clinical parameters were evaluated using the Oswestry Disability Index and visual analog scale. Subsidence of 26-mm-wide cages was compared with previous outcomes of patients undergoing ELIF using 18-mm-wide and 22-mm-wide cages. There were 21 patients and 28 spinal segments analyzed. Radiographic outcome measures such as disc and foraminal height revealed significant improvement at follow-up compared with before surgery (P = 0.001). Postoperative to last follow-up cage subsidence translated into 0.34 mm ± 0.26 and -0.55 mm ± 0.64 in disc and foraminal height loss, respectively. Patients with 26-mm-wide cages experienced less subsidence by means of disc (26 mm vs. 18 mm and 22 mm, P ≤ 0.05) and foraminal height (26 mm vs. 18 mm, P = 0.005; 26 mm vs. 22 mm, P = 0.208) loss compared with patients receiving 18-mm-wide and 22-mm-wide cages. The 26-mm-wide cages almost eliminated cage subsidence in ELIF. Compared with 18-mm-wide and 22-mm-wide cages, 26-mm-wide cages significantly reduced cage subsidence in ELIF at midterm follow-up. A 26-mm-wide cage should be used in ELIF to achieve sustained indirect decompression. Copyright © 2017. Published by Elsevier Inc.

  15. Anterior Lumbar Interbody Fusion Integrated Screw Cages: Intrinsic Load Generation, Subsidence, and Torsional Stability. (United States)

    Assem, Yusuf; Pelletier, Matthew H; Mobbs, Ralph J; Phan, Kevin; Walsh, William R


    To perform a repeatable idealized in vitro model to evaluate the effects of key design features and integrated screw fixation on unloaded surface engagement, subsidence, and torsional stability. We evaluated four different stand-alone anterior lumbar interbody fusion (ALIF) cages with two, three, and four screw designs. Polyurethane (saw-bone) foam blocks were used to simulate the vertebral bone. Fuji Film was used to measure the contact footprint, average pressure, and load generated by fixating the cages with screws. Subsidence was tested by axially loading the constructs at 10 N/s to 400 N and torsional load was applied +/-1 Nm for 10 cycles to assess stability. Outcome measures included total subsidence and maximal torsional angle range. Cages 1, 2, and 4 were symmetrical and produced similar results in terms of contact footprint, average pressure, and load. The addition of integrated screws into the cage-bone block construct demonstrated a clear trend towards decreased subsidence. Cage 2 with surface titanium angled ridges and a keel produced the greatest subsidence with and without screws, significantly more than all other cages ( P < 0.05). Angular rotation was not significantly affected by the addition of screws ( P < 0.066). A statistically significant correlation existed between subsidence and reduced angular rotation across all cage constructs ( P = 0.018). Each stand-alone cage featured unique surface characteristics, which resulted in differing cage-foam interface engagement, influencing the subsidence and torsional angle. Increased subsidence significantly reduced the torsional angle across all cage constructs. © 2017 Chinese Orthopaedic Association and John Wiley & Sons Australia, Ltd.

  16. Radiographic and clinical evaluation of cage subsidence after stand-alone lateral interbody fusion. (United States)

    Marchi, Luis; Abdala, Nitamar; Oliveira, Leonardo; Amaral, Rodrigo; Coutinho, Etevaldo; Pimenta, Luiz


    Indirect decompression of the neural structures through interbody distraction and fusion in the lumbar spine is feasible, but cage subsidence may limit maintenance of the initial decompression. The influence of interbody cage size on subsidence and symptoms in minimally invasive lateral interbody fusion is heretofore unreported. The authors report the rate of cage subsidence after lateral interbody fusion, examine the clinical effects, and present a subsidence classification scale. The study was performed as an institutional review board-approved prospective, nonrandomized, comparative, single-center radiographic and clinical evaluation. Stand-alone short-segment (1- or 2-level) lateral lumbar interbody fusion was investigated with 12 months of postoperative follow-up. Two groups were compared. Forty-six patients underwent treatment at 61 lumbar levels with standard interbody cages (18 mm anterior/posterior dimension), and 28 patients underwent treatment at 37 lumbar levels with wide cages (22 mm). Standing lateral radiographs were used to measure segmental lumbar lordosis, disc height, and rate of subsidence. Subsidence was classified using the following scale: Grade 0, 0%-24% loss of postoperative disc height; Grade I, 25%-49%; Grade II, 50%-74%; and Grade III, 75%-100%. Fusion status was assessed on CT scanning, and pain and disability were assessed using the visual analog scale and Oswestry Disability Index. Complications and reoperations were recorded. Pain and disability improved similarly in both groups. While significant gains in segmental lumbar lordosis and disc height were observed overall, the standard group experienced less improvement due to the higher rate of interbody graft subsidence. A difference in the rate of subsidence between the groups was evident at 6 weeks (p = 0.027), 3 months (p = 0.042), and 12 months (p = 0.047). At 12 months, 70% in the standard group and 89% in the wide group had Grade 0 or I subsidence, and 30% in the standard group

  17. The Correlation Between Cage Subsidence, Bone Mineral Density, and Clinical Results in Posterior Lumbar Interbody Fusion. (United States)

    Oh, Kyu Won; Lee, Jae Hyup; Lee, Ji-Ho; Lee, Do-Yoon; Shim, Hee Jong


    A retrospective review of prospectively collected radiographic and clinical data. This study aims to investigate the relationship between cage subsidence and bone mineral density (BMD), and to reveal the clinical implications of cage subsidence. Posterior lumbar interbody fusion (PLIF) has become one of the standard treatment modality for lumbar degenerative disease. However, cage subsidence might result in recurrent foraminal stenosis and deteriorate the clinical results. Furthermore, numbers of osteoporosis patients who underwent PLIF are increasing. Therefore, the information on the correlations between cage subsidence, BMD, and clinical results will be of great significance. A total 139 segments was included in this retrospective study. We examined functional rating index (Visual Analogue Scale for pain, Oswestry Disability Index, Short Form-36 score) preoperatively, and investigated their changes after postoperative 1 year. Correlation between cage subsidence and clinical scores was investigated. Plain anteroposterior and lateral radiograph were taken preoperatively and postoperatively and during follow-up. Preoperative BMD and subsidence measured by postoperative 1 year 3-dimensional computed tomography were achieved and their correlation was assessed. All postoperative clinical scores improved significantly compared with preoperative ones (pain Visual Analogue Scale: 7.34-2.89, Oswestry Disability Index: 25.34-15.86, Short Form-36: 26.45-16.46, all Psubsidence (r=-0.285, Psubsidence (>3 mm) compared with the segments in which T score were higher than -3.0 (P=0.012), and its odds ratio was 8.44. Subsidence had no significant correlation with all clinical scores. This study revealed that cage subsidence is relevant to BMD. However, it was demonstrated that subsidence is not related to the clinical deterioration. Therefore, PLIF procedure which is conducted carefully can be a good surgical option to treat lumbar degenerative disease for osteoporotic patients.

  18. Outcomes of contemporary use of rectangular titanium stand-alone cages in anterior cervical discectomy and fusion: cage subsidence and cervical alignment. (United States)

    Yamagata, Toru; Takami, Toshihiro; Uda, Takehiro; Ikeda, Hidetoshi; Nagata, Takashi; Sakamoto, Shinichi; Tsuyuguchi, Naohiro; Ohata, Kenji


    Cervical intervertebral disc replacement using a rectangular titanium stand-alone cage has become a standard procedure for anterior cervical discectomy and fusion (ACDF). We examined outcomes resulting from the contemporary use of rectangular titanium stand-alone cages for ACDF, particularly focusing on cage subsidence and subsequent kyphotic malalignment. Patient data were collected prospectively, and a total of 47 consecutive patients who underwent periodic follow-up of at least 1 year's duration after ACDF were studied retrospectively. Sixty-three rectangular titanium cages were implanted during 31 1-level and 16 2-level procedures. None of the patients developed surgery-related complications (including cage displacement or extrusion). Mean Neurosurgical Cervical Spine Scale scores were significantly improved at 1 year after surgery. Twelve of the 63 inserted cages (19.0%) were found to have cage subsidence, occurring in 11 of 47 patients (23.4%). There was no significant difference in functional recovery between patients with and without cage subsidence. Logistic regression analysis indicated that fusion level, cage size and cage position were significantly related to cage subsidence. The distraction ratio among patients with cage subsidence was significantly higher than that among patients without cage subsidence. Cage subsidence resulted in early deterioration of local angle and total alignment of the cervical spine. Although a longer follow-up is warranted, a good surgical outcome with negligible complications appears to justify the use of rectangular titanium stand-alone cages in 1- and 2-level ACDF. Excessive distraction at the fusion level should be avoided, and cage position should be adjusted to the anterior vertical line. Copyright © 2012 Elsevier Ltd. All rights reserved.

  19. Comparison of allograft and polyetheretherketone (PEEK) cage subsidence rates in anterior cervical discectomy and fusion (ACDF). (United States)

    Yson, Sharon C; Sembrano, Jonathan N; Santos, Edward Rainier G


    Structural allografts and PEEK cages are commonly used interbody fusion devices in ACDF. The subsidence rates of these two spacers have not yet been directly compared. The primary aim of this study was to compare the subsidence rate of allograft and PEEK cage in ACDF. The secondary aim was to determine if the presence of subsidence affects the clinical outcome. We reviewed 67 cases (117 levels) of ACDF with either structural allograft or PEEK cages. There were 85 levels (48 cases) with PEEK and 32 levels (19 cases) with allograft spacers. Anterior and posterior disc heights at each operative level were measured at immediate and 6months post-op. Subsidence was defined as a decrease in anterior or posterior disc heights >2mm. NDI of the subsidence (SG) and non-subsidence group (NSG) were recorded. Chi-square test was used to analyze subsidence rates. T-test was used to analyze clinical outcomes (α=0.05). There was no statistically significant difference between subsidence rates of the PEEK (29%; 25/85) and allograft group (28%; 9/32) (p=0.69). Overall mean subsidence was 2.3±1.7mm anteriorly and 2.6±1.2mm posteriorly. Mean NDI improvement was 11.7 (from 47.1 to 35.4; average follow-up: 12mos) for the SG and 14.0 (from 45.8 to 31.8; average follow-up: 13mos) for the NSG (p=0.74). Subsidence rate does not seem to be affected by the use of either PEEK or allograft as spacers in ACDF. Furthermore, subsidence alone does not seem to be predictive of clinical outcomes of ACDF. Copyright © 2017 Elsevier Ltd. All rights reserved.

  20. Radiologic Assessment of Subsidence in Stand-Alone Cervical Polyetheretherketone (PEEK) Cage. (United States)

    Ha, Sung-Kon; Park, Jung-Yul; Kim, Se-Hoon; Lim, Dong-Jun; Kim, Sang-Dae; Lee, Sang-Kook


    Aim of study was to find a proper method for assessing subsidence using a radiologic measurement following anterior cervical discectomy and fusion (ACDF) with stand-alone polyetheretherketone (PEEK), Solistrade mark cage. Forty-two patients who underwent ACDF with Solistrade mark cage were selected. With a minimum follow-up of 6 months, the retrospective investigation was conducted for 37 levels in 32 patients. Mean follow-up period was 18.9 months. Total intervertebral height (TIH) of two fused vertebral bodies was measured on digital radiographs with built-in software. Degree of subsidence (DeltaTIH) was reflected by the difference between the immediate postoperative and follow-up TIH. Change of postoperative disc space height (CT-MRDeltaTIH) was reflected by the difference between TIH of the preoperative mid-sagittal 2D CT and that of the preoperative mid-sagittal T1-weighted MRI. Compared to preoperative findings, postoperative disc height was increased in all cases and subsidence was observed only in 3 cases. For comparison of subsidence and non-subsidence group, TIH and CT-MRDeltaTIH of each group were analyzed. There was no statistically significant difference in TIH and CT-MRDeltaTIH between each group at 4 and 8 weeks, but a difference was observed at the last follow-up TIH (p=0.0497). ACDF with Solistrade mark cage was associated with relatively good radiologic long-term results. Fusion was achieved in 94.5% and subsidence occurred in 8.1% by the radiologic assessment. Statistical analysis reveals that the subsidence seen later than 8 weeks after surgery and the development of subsidence does not correlate statistically with the change of the postoperative disc space height.

  1. Vertebral Body Hounsfield Units are Associated With Cage Subsidence After Transforaminal Lumbar Interbody Fusion With Unilateral Pedicle Screw Fixation. (United States)

    Mi, Jie; Li, Kang; Zhao, Xin; Zhao, Chang-Qing; Li, Hua; Zhao, Jie


    To assess the association between Hounsfield units (HU) measurement and cage subsidence after lumbar interbody fusion. Transforaminal lumbar interbody fusion (TLIF) with unilateral fixation becomes a popular treatment modality for lumbar degenerative disease. Cage subsidence is a potentially devastating complication after lumbar interbody fusion with unilateral fixation. Recently, a new technique for assessing bone mineral density using HU values from computed tomography has been proposed. Bone quality is believed to be one of the important factors that cause cage subsidence after TLIF. Cage subsidence after single-level (L4/5) TLIF with unilateral fixation was prospectively documented at a single institution between 2013 and 2014. Patients with cage subsidence were matched 1:1 to a control cohort without cage subsidence on the basis of age and sex. HU values were measured from the preoperative computed tomography. All patients received computed tomographic scans at a minimum of 6 months postoperatively. Sagittal images were evaluated for evidence of cage subsidence. Eighteen patients with cage subsidence were well matched 1:1 to a cohort without cage subsidence and had complete imaging data. The global lumbar HU values were significantly lower in patients with cage subsidence than in the controls (112.4±10.08 vs. 140.2±10.17; P=0.0015). Similarly, a regional assessment of HU across the fusion levels was significantly lower in patients with cage subsidence (113.4±10.47 vs. 127.9±8.13; P=0.0075). The areas under the receiver operating characteristic cure were 0.715 and 0.636 for global and regional assessment, respectively. The best cut-offs for global and regional assessment were 132 (sensitivity: 83.3%; specificity: 61.1%) and 122 (sensitivity: 72.2%; specificity: 55.6%), respectively. Lower preoperative HU values is associated with cage subsidence after TLIF with unilateral fixation. HU measurement may be used as a predictor of cage subsidence after

  2. Influence of cervical bone mineral density on cage subsidence in patients following stand-alone anterior cervical discectomy and fusion. (United States)

    Brenke, Christopher; Dostal, Martin; Scharf, Johann; Weiß, Christel; Schmieder, Kirsten; Barth, Martin


    Anterior cervical discectomy and fusion (ACDF) is a common procedure for the treatment of cervical degenerative diseases. However, cage subsidence remains a frequent problem. We therefore investigated if cage design and site-specific bone mineral density (BMD) contribute to the rate and direction of subsidence following ACDF. Patients were prospectively included and received two different cages (groups 1 and 2) using minimization randomization. The degree and direction of cage subsidence were determined using plain radiographs. Neck pain intensity on the visual analogue scale (VAS), the neck disability index (NDI), and the patient satisfaction index were recorded up to 12 months after surgery. 88 patients were analysed with a mean age of 53.7 ± 11.8 years. BMD values decreased in craniocaudal direction from 302.0 ± 62.2 to 235.5 ± 38.9 mg/cm(3). Both groups showed significant height gain after the operation (both p  0.05). Both groups showed improvement of VAS neck pain intensity (both p subsidence was similar, no correlations were found between cage subsidence and BMD or various clinical parameters. Implant geometry of both cages and variations of the operative procedure promoted a relatively high degree of cage subsidence. Further studies are necessary to identify a relation of BMD and subsidence using optimized implant geometry and by controlling additional intraoperative variables.

  3. Fixed-Angle, Posteriorly Connected Anterior Cage Reconstruction Improves Stiffness and Decreases Cancellous Subsidence in a Spondylectomy Model. (United States)

    Colman, Matthew W; Guss, Andrew; Bachus, Kent N; Spiker, W Ryan; Lawrence, Brandon D; Brodke, Darrel S


    An idealized biomechanical model. The aim of this study was to evaluate the biomechanical properties of a construct designed to minimize intervertebral cage subsidence and maximize stiffness. Reconstruction after vertebral resection typically involves posterior segmental fixation and anterior interbody support. However, poor bone density, adjuvant radiation, or the oncologic need for endplate resection make interbody device subsidence and resultant instrumentation failure a significant concern. An idealized thoracolumbar spondylectomy reconstruction model was constructed using titanium segmental instrumentation and Delrin plastic. In vivo mechanical stress was simulated on a custom multi-axis spine simulator. Rigid body position in space was measured using an optical motion-capture system. Cancellous subsidence was modeled using a 1 cm thick wafer of number 3 closed-cell Sawbones foam at one endplate. Ten foam specimens were tested in a control state consisting of posterior segmental fixation with a free interbody cage. Ten additional foam specimens were tested in the test state, with the Delrin interbody cage "connected" to the posterior rods using two additional pedicle screws placed into the cage. Foam indentation was quantified using a precision digital surface-mapping device, and subsidence volume calculated using geometric integration. The control group exhibited significantly greater foam indentation after cycling, with a mean subsidence volume of 1906 mm [95% confidence interval (95% CI) 1810-2001] than the connected cage group subsidence volume of 977 mm (95% CI 928-1026 mm; P subsidence compared with a traditional unconnected cage. N/A.

  4. Risk factors for subsidence in anterior cervical fusion with stand-alone polyetheretherketone (PEEK) cages: a review of 82 cases and 182 levels. (United States)

    Kao, Ting-Hsien; Wu, Chen-Hao; Chou, Yu-Ching; Chen, Hsien-Te; Chen, Wen-Hsien; Tsou, Hsi-Kai


    To determine risk factors for subsidence in patients treated with anterior cervical discectomy and fusion (ACDF) and stand-alone polyetheretherketone (PEEK) cages. Records of patients with degenerative spondylosis or traumatic disc herniation resulting in radiculopathy or myelopathy between C2 and C7 who underwent ACDF with stand-alone PEEK cages were retrospectively reviewed. Cages were filled with autogenous cancellous bone harvested from iliac crest or hydroxyapatite. Subsidence was defined as a decrease of 3 mm or more of anterior or posterior disc height from that measured on the postoperative radiograph. Eighty-two patients (32 males, 50 females; 182 treatment levels) were included in the analysis. Most patients had 1-2 treatment levels (62.2 %), and 37.8 % had 3-4 treatment levels. Treatment levels were from C2-7. Of the 82 patients, cage subsidence occurred in 31 patients, and at 39 treatment levels. Multivariable analysis showed that subsidence was more likely to occur in patients with more than two treatment levels, and more likely to occur at treatment levels C5-7 than at levels C2-5. Subsidence was not associated with postoperative alignment change but associated with more disc height change (relatively oversized cage). Subsidence is associated with a greater number of treatment levels, treatment at C5-7 and relatively oversized cage use.

  5. Anatomy-related risk factors for the subsidence of titanium mesh cage in cervical reconstruction after one-level corpectomy. (United States)

    Wu, Jianxin; Luo, Dan; Ye, Xiaojian; Luo, Xuyao; Yan, Lisheng; Qian, Haiping


    To clarify anatomy-related risk factors in the cervical spine with subsidence of titanium mesh cage (TMC) after one-level cervical corpectomy and fusion, we have assessed the radiological examinations and clinical outcomes for 236 patients. All the patients were underwent one-level corpectomy and TMC fusion between August 2003 and March 2006. The effects of the cervical posture, segmental curvature and endplate gradient on the postoperative phenomenon for these patients were evaluated. Our results suggested that in the patients who were followed up for 12 months, TMC subsidence occurred in 54 (28.6%) cases. C6 corpectomy had a significant higher risk (26/60, 43.3%) for TMC subsidence, which was correlated with the variation of the gradient of the vertebral endplates against cervical levels. Although the clinical outcome was comparable with those in the literature, the patients may have subsidence-related problems such as neck-shoulder pain, neurological deterioration and instrumental failure. In conclusion, to reduce the incidence of subsidence, TMC design should be optimized to be in line with anatomic characteristics of the cervical spine.

  6. Cage subsidence does not, but cervical lordosis improvement does affect the long-term results of anterior cervical fusion with stand-alone cage for degenerative cervical disc disease: a retrospective study. (United States)

    Wu, Wen-Jian; Jiang, Lei-Sheng; Liang, Yu; Dai, Li-Yang


    Clinical outcomes of the stand-alone cage have been encouraging when used in anterior cervical discectomy and fusion (ACDF), but concerns remain regarding its complications, especially cage subsidence. This retrospective study was undertaken to investigate the long-term radiological and clinical outcomes of the stand-alone titanium cage and to evaluate the incidence of cage subsidence in relation to the clinical outcome in the surgical treatment of degenerative cervical disc disease. A total of 57 consecutive patients (68 levels) who underwent ACDF using a titanium box cage for the treatment of cervical radiculopathy and/or myelopathy were reviewed for the radiological and clinical outcomes. They were followed for at least 5 years. Radiographs were obtained before and after surgery, 3 months postoperatively, and at the final follow-up to determine the presence of fusion and cage subsidence. The Cobb angle of C2-C7 and the vertebral bodies adjacent to the treated disc were measured to evaluate the cervical sagittal alignment and local lordosis. The disc height was measured as well. The clinical outcomes were evaluated using the Japanese Orthopaedic Association (JOA) score for cervical myelopathy, before and after surgery, and at the final follow-up. The recovery rate of JOA score was also calculated. The Visual Analogue Scale (VAS) score of neck and radicular pain were evaluated as well. The fusion rate was 95.6% (65/68) 3 months after surgery. Successful bone fusion was achieved in all patients at the final follow-up. Cage subsidence occurred in 13 cages (19.1%) at 3-month follow-up; however, there was no relation between fusion and cage subsidence. Cervical and local lordosis improved after surgery, with the improvement preserved at the final follow-up. The preoperative disc height of both subsidence and non-subsidence patients was similar; however, postoperative posterior disc height (PDH) of subsidence group was significantly greater than of non-subsidence group

  7. Anterior cervical discectomy and fusion using a stand-alone polyetheretherketone cage packed with local autobone : assessment of bone fusion and subsidence. (United States)

    Park, Jeong-Ill; Cho, Dae-Chul; Kim, Kyoung-Tae; Sung, Joo-Kyung


    It remains debatable whether cervical spine fusion cages should be filled with any kind of bone or bone substitute. Cortical and subcortical bone from the anterior and posterior osteophytes of the segment could be used to fill the cage. The purposes of the present study are to evaluate the clinical outcomes and radiological outcomes including bone fusion and subsidence that occurred after anterior cervical discectomy and fusion using a stand-alone cage packed with local autobone graft. Thirty-one patients who underwent anterior cervical fusion using a stand-alone polyetheretherketone (PEEK) cage packed with local autobone graft from July 2009 to december 2011 were enrolled in this study. Bone fusion was assessed by cervical plain radiographs and computed tomographic scan. Nonunion was evaluated according to the absence of bony bridge on computed tomographic scan. Subsidence was defined as a ≥2 mm decrease of the interbody height at the final follow-up compared to that measured at the immediate postoperative period. Subsidence was observed in 7 patients (22.6%). Of 7 patients with subsidence greater 2 mm, nonunion was developed in 3. Three patients with subsidence greater 2 mm were related with endplate damage during intraoperative endplate preparation. Solid bone fusion was achieved in 28 out of 31 patients (90.3%). With proper patient selection and careful endplate preparation, anterior cervical discectomy and fusion (ACDF) using a stand-alone PEEK cage packed with local autobone graft could be a good alternative to the standard ACDF techniques with plating.

  8. Degenerative Cervical Disc Disease: Long-term Changes in Sagittal Alignment and Their Clinical Implications After Cervical Interbody Fusion Cage Subsidence: A Prospective Study With Standalone Lordotic Tantalum Cages. (United States)

    Tomé-Bermejo, Félix; Morales-Valencia, Julián A; Moreno-Pérez, Javier; Marfil-Pérez, Juan; Díaz-Dominguez, Elena; Piñera, Angel R; Alvarez, Luis


    A retrospective, observational study of prospectively collected outcomes. To investigate the long-term clinical course of anterior cervical discectomy and fusion with interbody fusion cages (ACDF-IFC) with lordotic tantalum implants and to correlate the radiologic findings with the clinical outcomes, with special emphasis on the significance and the influence of implant subsidence. Cage subsidence is the most frequently reported complication after ACDF-IFC. However, most reports fail to correlate cage subsidence with lower fusion rates or with unsatisfactory clinical results. Forty-one consecutive patients with symptomatic degenerative cervical disk disease with failure of conservative treatment were included. All patients underwent 1-/2-level ACDF-IFC with lordotic tantalum implants. The mean follow-up was 4.91 years. The final follow-up fusion rate was 96.96% (32/33). The interspace height (IH) at the affected levels was significantly incremented after implant insertion, and despite a gradual loss in the height over time, the final follow-up IH was significantly higher than that measured preoperatively (Psubsidence (>3 mm) occurred in 11 disk spaces (26.82%). Preoperative and postoperative IH were significantly higher in subsidence patients; however, there was no difference in the final follow-up IH (P>0.05). Patients with ≥3 years of follow-up (n=29) did not demonstrate further significant subsidence beyond the second year. Regarding C1-C7 lordosis, the segmental Cobb angle, the cervical Visual Analogue Scale, and Neck Disability Index questionnaires, no difference between patients with or without final follow-up endplate subsidence was encountered. Until fusion occurs, tantalum cage settlement into the vertebral body is to be expected. Further subsidence could be the result of segmental adaptative changes. Graft subsidence did not affect the clinical outcome in any of our patients during long-term follow-up. The occurrence of dynamical implant subsidence had

  9. Effect of posterior subsidence on cervical alignment after anterior cervical corpectomy and reconstruction using titanium mesh cages in degenerative cervical disease. (United States)

    Jang, Jae-Won; Lee, Jung-Kil; Lee, Jung-Heon; Hur, Hyuk; Kim, Tae-Wan; Kim, Soo-Han


    Subsidence after anterior cervical reconstruction using a titanium mesh cage (TMC) has been a matter of debate. The authors investigated and analyzed subsidence and its effect on clinical and radiologic parameters after cervical reconstruction using a TMC for degenerative cervical disease. Thirty consecutive patients with degenerative cervical spine disorders underwent anterior cervical corpectomy followed by reconstruction with TMC. Twenty-four patients underwent a single-level corpectomy, and six patients underwent a two-level corpectomy. Clinical outcomes were assessed using a Visual Analogue Scale (VAS), the Japanese Orthopedic Association (JOA) score and the Neck Disability Index (NDI). Fusion status, anterior and posterior subsidence of the TMC, segmental angle (SA) and cervical sagittal angle (CSA) were assessed by lateral and flexion-extension radiographs of the neck. The mean follow-up period was 27.6 months (range, 24 to 49 months). The VAS, NDI and JOA scores were all significantly improved at the last follow-up. No instances of radiolucency or motion-related pseudoarthrosis were detected on radiographic analysis, yielding a fusion rate of 100%. Subsidence occurred in 28 of 30 patients (93.3%). The average anterior subsidence of the cage was 1.4 ± 0.9 mm, and the average posterior subsidence was 2.9 ± 1.2 mm. The SA and CSA at the final follow-up were significantly increased toward a lordotic angle. Anterior cervical reconstruction using TMC and plating in patients with cervical degenerative disease provides good clinical and radiologic outcomes. Cage subsidence occurred frequently, especially at the posterior part of the cage. Despite the prominent posterior subsidence of the TMC, SA and CSA were improved on final follow-up radiographs, suggesting that posterior subsidence may contribute to cervical lordosis. Copyright © 2014 Elsevier Ltd. All rights reserved.

  10. PEEK Cages versus PMMA Spacers in Anterior Cervical Discectomy: Comparison of Fusion, Subsidence, Sagittal Alignment, and Clinical Outcome with a Minimum 1-Year Follow-Up (United States)

    Krüger, Marie T.; Sircar, Ronen; Kogias, Evangelos; Scholz, Christoph; Volz, Florian; Scheiwe, Christian; Hubbe, Ulrich


    Purpose. To compare radiographic and clinical outcomes after anterior cervical discectomy in patients with cervical degenerative disc disease using PEEK cages or PMMA spacers with a minimum 1-year follow-up. Methods. Anterior cervical discectomy was performed in 107 patients in one or two levels using empty PEEK cages (51 levels), Sulcem PMMA spacers (49 levels) or Palacos PMMA spacers (41 levels) between January, 2005 and February, 2009. Bony fusion, subsidence, and sagittal alignment were retrospectively assessed in CT scans and radiographs at follow-up. Clinical outcome was measured using the VAS, NDI, and SF-36. Results. Bony fusion was assessed in 65% (PEEK cage), 57% (Sulcem), and 46% (Palacos) after a mean follow-up of 2.5 years. Mean subsidence was 2.3–2.6 mm without significant differences between the groups. The most pronounced loss of lordosis was found in PEEK cages (−4.1°). VAS was 3.1 (PEEK cage), 3.6 (Sulcem), and 2.7 (Palacos) without significant differences. Functional outcome in the PEEK cage and Palacos group was superior to the Sulcem group. Conclusions. The substitute groups showed differing fusion rates. Clinical outcome, however, appears to be generally not correlated with fusion status or subsidence. We could not specify a superior disc substitute for anterior cervical discectomy. This trial is registered with DRKS00003591. PMID:25110734

  11. Preventing Construct Subsidence Following Cervical Corpectomy: The Bump-stop Technique. (United States)

    Shaw, Kenneth Aaron; Griffith, Matthew; Mottern, Edward T; Gloystein, David M; Devine, John G


    Cervical corpectomy is a viable technique for the treatment of multilevel cervical spine pathology. Despite multiple advances in both surgical technique and implant technology, the rate of construct subsidence can range from 6% for single-level procedures to 71% for multilevel procedures. In this technical note, we describe a novel technique, the bump-stop technique, for cervical corpectomy. The technique positions the superior and inferior screw holes such that the vertebral bodies bisect them. This allows for fixation in the dense cortical bone of the endplate while providing a buttress to corpectomy cage subsidence. We then discuss a retrospective case review of 24 consecutive patients, who were treated using this approach, demonstrating a lower than previously reported cage subsidence rate.

  12. A Lower T1 Slope as a Predictor of Subsidence in Anterior Cervical Discectomy and Fusion with Stand-Alone Cages. (United States)

    Lee, Su Hun; Lee, Jun Seok; Sung, Soon Ki; Son, Dong Wuk; Lee, Sang Weon; Song, Geun Sung


    Preoperative parameters including the T1 slope (T1S) and C2-C7 sagittal vertical axis (SVA) have been recognized as predictors of kyphosis after laminoplasty, which is accompanied by posterior neck muscle damage. The importance of preoperative parameters has been under-estimated in anterior cervical discectomy and fusion (ACDF) because there is no posterior neck muscle damage. We aimed to determine whether postoperative subsidence and pseudarthrosis could be predicted according to specific parameters on preoperative plain radiographs. We retrospectively analyzed 41 consecutive patients (male: female, 22: 19; mean age, 51.15±9.25 years) who underwent ACDF with a stand-alone polyether-ether-ketone (PEEK) cage (>1 year follow-up). Parameters including SVA, T1S, segmental angle and range of motion (ROM), C2-C7 cervical angle and ROM, and segmental inter-spinous distance were measured on preoperative plain radiographs. Risk factors of subsidence and pseudarthrosis were determined using multivariate logistic regression. Fifty-five segments (27 single-segment and 14 two-segment fusions) were included. The subsidence and pseudarthrosis rates based on the number of segments were 36.4% and 29.1%, respectively. Demographic data and fusion level were unrelated to subsidence. A greater T1S was associated with a lower risk of subsidence (p=0.017, odds ratio=0.206). A cutoff value of T1Ssubsidence (sensitivity: 70%, specificity: 68.6%). There were no preoperative predictors of pseudarthrosis except old age. A lower T1S (T1Ssubsidence following ACDF. Surgeons need to be aware of this risk factor and should consider various supportive procedures to reduce the subsidence rates for such cases.

  13. Fusion and subsidence rate of stand alone anterior lumbar interbody fusion using PEEK cage with recombinant human bone morphogenetic protein-2. (United States)

    Behrbalk, Eyal; Uri, Ofir; Parks, Ruth M; Musson, Rachel; Soh, Reuben Chee Cheong; Boszczyk, Bronek Maximilian


    Anterior lumbar interbody fusion (ALIF) is an established treatment for structural instability associated with symptomatic disk degeneration (SDD). Stand-alone ALIF offers many advantages, however, it may increase the risk of non-union. Recombinant human bone morphogenetic protein-2 (BMP-2) may enhance fusion rate but is associated with postoperative complication. The optimal dose of BMP-2 remains unclear. This study assessed the fusion and subsidence rates of stand-alone ALIF using the SynFix-LR interbody cage with 6 ml/level of BMP-2. Thirty-two ALIF procedures were performed by a single surgeon in 25 patients. Twenty-five procedures were performed for SDD without spondylolisthesis (SDD group) and seven procedures were performed for SDD with grade-I olisthesis (SDD-olisthesis group). Patients were followed-up for a mean of 17 ± 6 months. Solid fusion was achieved in 29 cases (90.6 %) within 6 months postoperatively. Five cases of implant subsidence were observed (16 %). Four of these occurred in the SDD-olisthesis group and one occurred in the SDD group (57 % vs. 4 % respectively; p = 0.004). Three cases of subsidence failed to fuse and required revision. The body mass index of patients with olisthesis who developed subsidence was higher than those who did not develop subsidence (29 ± 2.6 vs. 22 ± 6.5 respectively; p = 0.04). No BMP-2 related complications occurred. The overall fusion rate of stand-alone ALIF using the SynFix-LR system with BMP-2 was 90.6 %, comparable with other published series. No BMP-2 related complication occurred at a dose of 6 mg/level. Degenerative spondylolisthesis and obesity seemed to increase the rate of implant subsidence, and thus we believe that adding posterior fusion for these cases should be considered.

  14. Is the radiographic subsidence of stand-alone cages associated with adverse clinical outcomes after cervical spine fusion? An observational cohort study with 2-year follow-up outcome scoring. (United States)

    Zajonz, Dirk; Franke, Anne-Catherine; von der Höh, Nicolas; Voelker, Anna; Moche, Michael; Gulow, Jens; Heyde, Christoph-Eckhard


    The stand-alone treatment of degenerative cervical spine pathologies is a proven method in clinical practice. However, its impact on subsidence, the resulting changes to the profile of the cervical spine and the possible influence of clinical results compared to treatment with additive plate osteosynthesis remain under discussion until present. This study was designed as a retrospective observational cohort study to test the hypothesis that radiographic subsidence of cervical cages is not associated with adverse clinical outcomes. 33 cervical segments were treated surgically by ACDF with stand-alone cage in 17 patients (11 female, 6 male), mean age 56 years (33-82 years), and re-examined after eight and twenty-six months (mean) by means of radiology and score assessment (Medical Outcomes Study Short Form (MOS-SF 36), Oswestry Neck Disability Index (ONDI), painDETECT questionnaire and the visual analogue scale (VAS)). Subsidence was observed in 50.5% of segments (18/33) and 70.6% of patients (12/17). 36.3% of cases of subsidence (12/33) were observed after eight months during mean time of follow-up 1. After 26 months during mean time of follow-up 2, full radiographic fusion was seen in 100%. MOS-SF 36, ONDI and VAS did not show any significant difference between cases with and without subsidence in the two-sample t-test. Only in one type of scoring (painDETECT questionnaire) did a statistically significant difference in t-Test emerge between the two groups (p = 0.03; α = 0.05). However, preoperative painDETECT score differ significantly between patients with subsidence (13.3 falling to 12.6) and patients without subsidence (7.8 dropped to 6.3). The radiological findings indicated 100% healing after stand-alone treatment with ACDF. Subsidence occurred in 50% of the segments treated. No impact on the clinical results was detected in the medium-term study period.

  15. Outcome of single level anterior cervical discectomy and fusion using nano-hydroxyapatite/polyamide-66 cage

    Directory of Open Access Journals (Sweden)

    Xi Yang


    Full Text Available Background: Cages have been widely used for the anterior reconstruction and fusion of cervical spine. Nonmetal cages have become popular due to prominent stress shielding and high rate of subsidence of metallic cages. This study aims to assess fusion with n-HA/PA66 cage following one level anterior cervical discectomy. Materials and Methods: Forty seven consecutive patients with radiculopathy or myelopathy underwent single level ACDF using n-HA/PA66 cage. We measured the segmental lordosis and intervertebral disc height on preoperative radiographs and then calculated the loss of segmental lordosis correction and cage subsidence over followup. Fusion status was evaluated on CT scans. Odom criteria, Japanese Orthopedic Association (JOA and Visual Analog Pain Scales (VAS scores were used to assess the clinical results. Statistically quantitative data were analyzed while Categorical data by χ2 test. Results: Mean correction of segmental lordosis from surgery was 6.9 ± 3.0° with a mean loss of correction of 1.7 ± 1.9°. Mean cage subsidence was 1.2 ± 0.6 mm and the rate of cage subsidence (>2 mm was 2%. The rate of fusion success was 100%. No significant difference was found on clinical or radiographic outcomes between the patients (n=27 who were fused by n-HA/PA66 cage with pure local bone and the ones (n=20 with hybrid bone (local bone associating with bone from iliac crest. Conclusions: The n-HA/PA66 cage is a satisfactory reconstructing implant after anterior cervical discectomy, which can effectively promote bone graft fusion and prevent cage subsidence.

  16. Prevention partition for land subsidence induced by engineering dewatering in Shanghai

    Directory of Open Access Journals (Sweden)

    J. X. Wang


    Full Text Available Land subsidence in shanghai has been found for more than 70 years. In the early years, it was mainly caused by groundwater exploitation. In recent years, engineering dewatering in shallow ground (within 90 m has become a major source for land subsidence in the rapid urbanization course. A management partition of land subsidence induced by foundation pit dewatering for the first confined aquifer was suggested.

  17. Preventing and controlling land subsidence in Shanghai -towards more integrated and effective land use and ground water governance in the Yangtze Delta (United States)

    Dai, Liping


    The Yangtze Delta, covers 210,700 square kilometers and with 156 million inhabitants (NRDC, 2010; The National Bureau of Statistics, 2011), is one of the areas most severely affected by land subsidence in China. Up to 2012, the area with cumulative subsidence above 200 mm in Yangtze Delta has been closed to 10,000 square kilometers. Shanghai, located at the estuary of the Yangtze River and with a population of 23 million, is the most densely populated city in Yangtze Delta (The National Bureau of Statistics, 2011). Since 1921, the recorded cumulative subsidence has been 200 to 300 mm in the central area of the city (Chai, Shen, Zhu, & Zhang, 2005). Excessive pumping of groundwater is considered to be the leading reason, accounts for nearly 70%, of the city's land subsidence, the weight of skyscrapers and global warming also play hefty roles (30%) (Springer, 2012). Research has shown that the main method to control land subsidence in Shanghai is to prevent groundwater from dropping (Chai, Shen, Zhu, & Zhang, 2005), the city has made great efforts in this regard since 1965 (the beginning of the so-called "control period"), for example, it has been recharging underground water through 121 wells with more than 60,000 tons every day since 2012 (Chinadaily, 2012). It is a huge burden considering the city has been suffering from a shortage of fresh water. In 2013, with the other two provinces of Jiangsu and Zhejiang in Yangtze Delta, Shanghai signed a delta cooperation agreement on the prevention and control of land subsidence and jointly issued a Prevention and Control Planning on Land Subsidence in Yangtze Delta (2014-2020), which aims to establish a long-effect mechanism in the delta scope. This research aims to analyze and assess the land and groundwater governance arrangements related to land subsidence in the Yangtze Delta in general and Shanghai in specific, in order to develop optimizing adaptation strategies and associated governance arrangements. It examines the

  18. Cement augmentation in the proximal femur to prevent stem subsidence in revision hip arthroplasty with Paprosky type II/IIIa defects. (United States)

    Tsai, Shang-Wen; Chen, Cheng-Fong; Wu, Po-Kuei; Chen, Chao-Ming; Chen, Wei-Ming


    Subsidence remains a common complication after revision hip arthroplasty which may lead to prolonged weight-bearing restrictions, leg-length discrepancies or considerable loss of function. We evaluated the effectiveness of cement augmentation in the proximal femoral metaphysis during a revision of femoral components to prevent post-operative stem subsidence. Forty patients were enrolled. Follow-up averaged 67.7 months (range: 24-149). Twenty-seven patients had a Paprosky type II defect and 13 had a type IIIa defect. All revision hip arthroplasty used a cementless, cylindrical, non-modular cobalt-chromium stem. The defect in the metaphysis was filled with antibiotic-loaded bone cement. Thirteen patients who had undergone stem revision only was allowed to walk immediately without weight-bearing restrictions. Twenty-seven patients who had undergone revision total hip arthroplasty was allowed partial weight-bearing within 6 weeks after surgery in the consideration of acetabular reconstruction. Three patients (7.5%) had post-surgery stem subsidences of three mm, five mm, and 10 mm, respectively, at three, one, and 14 months. There were no acute surgical site infections. There were three femoral stem failures: two delayed infections and one periprosthetic Vancouver B2 fracture. Both five- and 10-year survivorships of the femoral implant were 90.1%. An adequate length of the scratch-fit segment and diaphyseal ingrowth remain of paramount importance when revising femoral components. To fill metaphyseal bone defects with antibiotic-loaded bone cement may be an alternative method in dealing with proximal femoral bone loss during a femoral revision. Copyright © 2018. Published by Elsevier Taiwan LLC.

  19. Anterior lumbar interbody fusion using a barbell-shaped cage: a biomechanical comparison. (United States)

    Murakami, H; Boden, S D; Hutton, W C


    There are drawbacks to using threaded cylindrical cages (e.g., limited area for bone ingrowth and metal precluding radiographic visualization of bone healing). To somewhat offset these drawbacks, a barbell-shaped cage has been designed. The central core of the barbell can be wrapped with collagen sheets infiltrated with bone morphogenetic protein. The obvious theoretical advantages of a barbell cage have to be weighed against potential biomechanical disadvantages. Our purpose was to compare the biomechanical properties of an anterior lumbar interbody reconstruction using 18-mm-diameter threaded cylindrical cages, with a reconstruction using barbell cages (18-mm diameter and 6 mm wide at both cylindrical ends, with a round 4-mm-diameter bar joining the two ends). Twelve cadaveric lumbar motion segments were tested. Three L5-S1 segments received two threaded cylindrical cages, and three L5-S1 segments received two barbell cages. Three L3-L4 segments received one threaded cylindrical cage, and three L3-L4 segments received one barbell cage. A series of biomechanical loading sequences were carried out on each motion segment, and stiffness curves were obtained. After the biomechanical testing, an axial compressive load was applied to the motion segments until failure. They were then radiographed and bisected through the disc, and the subsidence (or penetration) of the cage(s) in the cancellous bone of the vertebral bodies was measured. There was no difference in terms of stiffness between the motion segments with the threaded cylindrical cage(s) inserted and those with the barbell cage(s) inserted (p > 0.15). The average values of subsidence was 0.96 mm for the threaded cylindrical cage group and 0.80 mm for the barbell cage group (difference not significant: p = 0.38). The results suggest that a reconstruction using barbell cages is a biomechanically acceptable alternative to one using threaded cylindrical cages.

  20. Rescue Implantation of Expandable Cages for Severe Osteolysis and Cage Dislocation in the Lumbosacral Junction. (United States)

    Schatlo, Bawarjan; Rohde, Veit; Solomiichuk, Volodymyr; von Eckardstein, Kajetan; Behm, Timo


    Osteolysis and implant loosening are commonly encountered problems after spinal instrumentation. In a patient who had previously undergone a posterior lumbar interbody fusion procedure, fusion did not occur, and a secondary cage dislocation led to an impingement of the L5 nerve root with severe radiculopathy. Revision surgery was performed. Intraoperatively, osteolysis was found to be so severe that conventional cages did not fill the void to allow for sufficient anterior column support. We used expandable transforaminal lumbar interbody fusion cages and implanted them bilaterally to replace the dislodged posterior lumbar interbody fusion cages. Clinical follow-up was uneventful. Imaging performed at 1 year showed satisfactory cage position and fusion. We propose the use of cages with the ability of ventral distraction in similar rescue interventions with cage dislocation and bone resorption. This may prevent a second surgery via a ventral approach. Copyright © 2017 Elsevier Inc. All rights reserved.

  1. Competitive Cross-Subsidization


    Chen, Zhijun; Rey, Patrick


    Cross-subsidization arises naturally when firms with different comparative ad- vantages compete for consumers with diverse shopping patterns. Firms then face a form of co-opetition, being substitutes for one-stop shoppers and complements for multi-stop shoppers. Competition for one-stop shoppers then drives total prices down to cost, but firms subsidize weak products with the profit made on strong products. While firms and consumers would benefit from cooperation limiting cross- subsidization...

  2. Simulation of geothermal subsidence

    Energy Technology Data Exchange (ETDEWEB)

    Miller, I.; Dershowitz, W.; Jones, K.; Myer, L.; Roman, K.; Schauer, M.


    The results of an assessment of existing mathematical models for subsidence simulation and prediction are summarized. The following subjects are discussed: the prediction process, physical processes of geothermal subsidence, computational models for reservoir flow, computational models for deformation, proficiency assessment, and real and idealized case studies. (MHR)

  3. Review of geothermal subsidence

    Energy Technology Data Exchange (ETDEWEB)

    Phillips, S.L.; Fair, J.A.; Henderson, F.B. III; Schwartz, S.R.


    Forty-nine citations are included most of which deal with geothermal subsidence. Other citations deal with subsidence caused by groundwater overdraft and oil and gas exploitation. Most of the entries have abstracts. A subject index, an author index, a list of references, and a glossary are included. (MHR)

  4. Subsidence after anterior cervical inter-body fusion. A randomized prospective clinical trial. (United States)

    Kast, Erich; Derakhshani, Sharam; Bothmann, Matthias; Oberle, Joachim


    In ventral fusion after anterior cervical discectomy there is still a remarkable number of cage subsidence and segmental kyphosis seen. The aim of the present study is to assess whether the cage design influences the extent of correction loss during follow-up. Sixty patients with single-level cervical disc herniation were randomly treated with two different cervical inter-body cages (group 1: Solis cage, Stryker Company and group 2: Shell cage, AMT Company). Clinical and radiological follow-up was done before and after surgery, 3 and 6 months post-surgery. Clinical follow-up was done with the help of Odom's criteria. Both groups were similar in the baseline parameters (age, sex, treated level). Statistically, the subsidence was significantly higher at 3 and 6-month follow-ups in group 1 than in group 2, however, clinical results showed no significant differences. In 67%, subsidence was seen in the anterior lower aspect of the treated segment. Segmental kyphosis was seen in seven patients of group 1 and two patients of group 2. A significant correlation is found between Odom's criteria and subsidence. Although there was no significant difference in a short-term clinical result between the two treatment groups, we recommend the use of cages which preserve the determined segmental height and lordosis.

  5. Assessment and classification of subsidence after lateral interbody fusion using serial computed tomography. (United States)

    Malham, Gregory M; Parker, Rhiannon M; Blecher, Carl M; Seex, Kevin A


    OBJECT Intervertebral cage settling during bone remodeling after lumbar lateral interbody fusion (LIF) is a common occurrence during the normal healing process. Progression of this settling with endplate collapse is defined as subsidence. The purposes of this study were to 1) assess the rate of subsidence after minimally invasive (MIS) LIF by CT, 2) distinguish between early cage subsidence (ECS) and delayed cage subsidence (DCS), 3) propose a descriptive method for classifying the types of subsidence, and 4) discuss techniques for mitigating the risk of subsidence after MIS LIF. METHODS A total of 128 consecutive patients (with 178 treated levels in total) underwent MIS LIF performed by a single surgeon. The subsidence was deemed to be ECS if it was evident on postoperative Day 2 CT images and was therefore the result of an intraoperative vertebral endplate injury and deemed DCS if it was detected on subsequent CT scans (≥ 6 months postoperatively). Endplate breaches were categorized as caudal (superior endplate) and/or cranial (inferior endplate), and as ipsilateral, contralateral, or bilateral with respect to the side of cage insertion. Subsidence seen in CT images (radiographic subsidence) was measured from the vertebral endplate to the caudal or cranial margin of the cage (in millimeters). Patient-reported outcome measures included visual analog scale, Oswestry Disability Index, and 36-Item Short Form Health Survey physical and mental component summary scores. RESULTS Four patients had ECS in a total of 4 levels. The radiographic subsidence (DCS) rates were 10% (13 of 128 patients) and 8% (14 of 178 levels), with 3% of patients (4 of 128) exhibiting clinical subsidence. In the DCS levels, 3 types of subsidence were evident on coronal and sagittal CT scans: Type 1, caudal contralateral, in 14% (2 of 14), Type 2, caudal bilateral with anterior cage tilt, in 64% (9 of 14), and Type 3, both endplates bilaterally, in 21% (3 of 14). The mean subsidence in the DCS

  6. Coal mine subsidence

    International Nuclear Information System (INIS)

    Rahall, N.J.


    This paper examines the efficacy of the Department of the Interior's Office of Surface Mining Reclamation and Enforcement's (OSMRE) efforts to implement the federally assisted coal mine subsidence insurance program. Coal mine subsidence, a gradual settling of the earth's surface above an underground mine, can damage nearby land and property. To help protect property owners from subsidence-related damage, the Congress passed legislation in 1984 authorizing OSMRE to make grants of up to $3 million to each state to help the states establish self-sustaining, state-administered insurance programs. Of the 21 eligible states, six Colorado, Indiana, Kentucky, Ohio, West Virginia, and Wyoming applied for grants. This paper reviews the efforts of these six states to develop self-sustaining insurance programs and assessed OSMRE's oversight of those efforts

  7. Subsidence Induced by Underground Extraction (United States)

    Galloway, Devin L.


    Subsidence induced by underground extraction is a class of human-induced (anthropogenic) land subsidence that principally is caused by the withdrawal of subsurface fluids (groundwater, oil, and gas) or by the underground mining of coal and other minerals.

  8. Lumbar interbody fusion: a parametric investigation of a novel cage design with and without posterior instrumentation. (United States)

    Galbusera, Fabio; Schmidt, Hendrik; Wilke, Hans-Joachim


    A finite element model of the L4-L5 human segment was employed to carry out a parametric biomechanical investigation of lumbar interbody fusion with a novel "sandwich" cage having an inner stiff core and two softer layers in the areas close to the endplates, with and without posterior fixation. Considered cage designs included: (a) cage in a homogeneous material with variable elastic modulus (19-2,000 MPa), (b) "sandwich" cage having an inner core (E=2,000 MPa) and softer layers (E=19 MPa) with variable thickness (1-2.5 mm). The latter cage was also considered in combination with posterior rods made with a material having variable elastic modulus (19-210,000 MPa). All the models were loaded with 500 N compression and moments of 7.5 Nm in flexion, extension, lateral bending and axial rotation. The homogeneous cage stabilized the segment in flexion, lateral bending and axial rotation; in extension there was a destabilization up to 60% and remarkable cage movement (1 mm). The "sandwich" cage limited this phenomenon (cage movement<0.6 mm), effectively stabilized the segment in the other directions and lowered the maximal contact pressure on the endplates, reducing the risk of subsidence. Posterior fixation reduced spinal flexibility and cage movement. The soft layers of the "sandwich" cage had the potential to limit the risk of cage subsidence and to preserve a significant loading of the structure even in combination with flexible posterior instrumentation, which may have a beneficial effect in promoting bony fusion.

  9. The effect of angular mismatch between vertebral endplate and vertebral body replacement endplate on implant subsidence. (United States)

    Mohammad-Shahi, Mohammad H; Nikolaou, Vassilios S; Giannitsios, Demetrios; Ouellet, Jean; Jarzem, Peter F


    Comparative biomechanical study. To determine whether an angular mismatch between the vertebral body replacement (VBR) endplate and the simulated foam vertebral endplate leads to accelerated subsidence in a cyclic compression model of the VBR-vertebra interface. One of the main complications of the VBR surgery is postoperative subsidence and collapse of the VBR implant into the adjacent vertebral bodies. Although numerous factors affecting intervertebral cage subsidence have been cited, few studies have proposed factors responsible for VBR cage subsidence. Hardwood blocks at 0-30-degree angles and polyurethane foam blocs have been used as base for this experimental setting. One end of the Synex (Synthes) expandable cage was attached to a material testing machine. The endplate of the implant was placed at a similar spot on the block in such a manner that there was an exact match between the Synex endplate and the foam block at 0 degrees, subsequent angled blocks would tilt the foam endplates by the 10-, 20-, and 30-degree increments as needed. Cyclic axial loads were applied in 9 load-unload cycles. Five samples were tested at each mismatch angle (0, 10, 20, and 30 degrees), for a total of 20 trials. Implant subsidence significantly increased for each 10-degree increase in mismatch angle. This effect, however, did not follow a uniform trend at all angles. The curve appeared exponential at 0 degree of angular mismatch, became linear at 10-20 degrees of mismatch, and then demonstrated some ability to resist load at 30 degrees, leading to a plateau at the higher loads. Increasing mismatch angles are an important factor in leading to increased cage subsidence into polyurethane blocks. Consequently, the incidence of subsidence in the clinical setting could be reduced by paying careful attention to ensuring that both the prosthetic and bony endplates are well apposed at the end of surgery.

  10. Subsidence following anterior lumbar interbody fusion (ALIF): a prospective study. (United States)

    Rao, Prashanth J; Phan, Kevin; Giang, Gloria; Maharaj, Monish M; Phan, Steven; Mobbs, Ralph J


    Anterior lumbar interbody fusion (ALIF) is a widely used surgical technique for disorders of the lumbar spine. One potential complication is the subsidence of disc height in the post-operative period. Few studies have reported the rate of subsidence in ALIF surgery prospectively. We prospectively evaluated the rate of subsidence in adult patients undergoing ALIF. Results were obtained by reviewing scans of 147 patients. Disc heights were measured on radiographic scans taken pre-operatively in addition to post-operatively immediately, at 6 weeks and at 18 months. The anterior and posterior intervertebral disc heights were measured. Subsidence was defined as greater than or equal to 2 mm loss of height. A total of 15 patients (10.2%) had subsidence, with 7 being male. Each case was of delayed cage subsidence (DCS) >6 weeks postoperatively. The mean subsidence was 4.7 mm (range, 2.4-7.8). Mean anterior disc height was 8.6±0.4 mm preoperatively, which improved to 15.1±0.5 mm at latest follow-up. Mean posterior disc height was 4.7±0.2 mm preoperatively, which improved to 8.7±0.4 mm at latest follow-up. The mean lumbar lordosis (LL) angle was 42.5°±10.8° and the mean local disc angle (LDA) was 6.7°±4.0°. The 91.2% (n=114/125) of patients with appropriate radiological follow-up demonstrated fusion by latest follow-up. There was no correlation between subsidence rate with patient reported outcomes [Visual Analog Scale (VAS), Oswestry Disability Index (ODI) and Short Form 12 Item survey (SF-12)] and fusion rates. There was a significant negative correlation between LL and extent of subsidence (Pearson correlation =-0.754, P=0.012). In conclusion, we found that the subsidence rate at follow-up was generally low following standalone ALIF for this patient series. Patient clinical outcomes and bony fusion rates were not significantly influenced by subsidence.

  11. Formation mechanism of land subsidence in the North China Plain (United States)

    Guo, Haipeng; Cheng, Guoming


    development trend, and then provides technical support for study on prevention and control measures to efficiently inhibit the development trend of land subsidence.

  12. Subsidizing Media Innovation

    DEFF Research Database (Denmark)

    Kammer, Aske; Hobel, Emil

    When the Danish Parliament revised the media-subsidy framework in 2013/2014, one of the new initiatives was the introduction of a pool of funding earmarked to establishing and developing new news media – the so-called “innovation fund”. So, as the news industry struggles to keep journalism a viab...... subsidized, (2) what characterizes the successful applicants’ approaches to innovation, and (3) which patterns exist in this connection, and it measures each of these three dimensions against the welfare framework that the national context provides....

  13. Management of Talar Component Subsidence. (United States)

    Li, Shu-Yuan; Myerson, Mark S


    Component subsidence has been found to be the top complication that leads to failure of the total ankle arthroplasty (TAA). The cause of subsidence formation is unclear, and is multifactorial. Talar subsidence is more frequently met than tibial subsidence, and the subsequent big bone loss is demanding to handle. As a revision treatment option, neither a revision TAA nor a salvage ankle and/or hindfoot arthrodesis procedure is easy to perform or can obtain a definite outcome. The Salto XT can be used to treat most of the TAA systems available for use in the United States with acceptable short-term outcomes. Copyright © 2017 Elsevier Inc. All rights reserved.

  14. Commercial cage fish culture


    Aigbadon, B.V.


    With increasing emphasis in Nigeria on aquaculture as an alternative to dwindling artisanal fishing and scarce foreign exchange for fish import, cage fish culture, is a more profitable aquaculture practice than pond culture. It appears to be one of the most viable business ventures with minimum risks. It is a highly recommendable project

  15. Two-piece ALIF cage optimizes the bone-implant interface in a 360° setting. (United States)

    Wilke, Hans-Joachim; Volkheimer, David; Robie, Bruce; Christensen, Finn B


    Clinical research has documented that cage subsidence and the loss of balance correction is a significant complication related to spinal fusion. Subsidence is a multifactorial complication, where implant design is one important element. The aim of the study is to compare the rigidity and bone-implant relative motion of segments treated with either a conventional one-piece ALIF cage versus a two-piece ALIF cage, which adapts in situ and permits 7°-21° of lordosis. Seven lumbosacral (L3-S1) human cadaver specimens were tested in a universal spine tester in the intact condition, the specimens instrumented with a two-piece ALIF cage (Statur ® -L, FBC Device, Denmark) and a one-piece ALIF cage (Pezo™-A, Ulrich GmbH & Co. KG., Germany), both supplemented with a pedicle screw system using pure moments of ±7.5 Nm in three principal motion directions. For assessment of the bone-implant interface, fluoroscopic videos were captured during motion and 3D motion was measured using an optical motion capturing system. Significantly less motion at the implant-endplate interface was found for the two-piece cage (1.0° ± 0.6°) in comparison to the one-piece cage (4.2° ± 1.7°) in flexion/extension. No significant differences in segment rigidity were found between the one-piece and two-piece cages in the 360° setup, while both configurations significantly reduced the range of motion compared to the intact condition (p one-piece ALIF cages, the two-piece cage concept reduced the relative motion at the bone-implant interface without compromising stability.

  16. Towards a global land subsidence map

    NARCIS (Netherlands)

    Erkens, G.; Sutanudjaja, E. H.


    Land subsidence is a global problem, but a global land subsidence map is not available yet. Such map is crucial to raise global awareness of land subsidence, as land subsidence causes extensive damage (probably in the order of billions of dollars annually). With the global land subsidence map

  17. Groundwater exploitation management under land subsidence constraint: empirical evidence from the Hangzhou-Jiaxing-Huzhou Plain, China. (United States)

    Cao, Guoliang; Han, Dongmei; Moser, Jessa


    Land subsidence caused by extensive groundwater pumping has become a factor which cannot be ignored in the sustainable exploitation of groundwater resources. The Hangzhou-Jiaxing-Huzhou Plain is one of the locations with China's most severe land subsidence problems; the region has experienced dramatic land subsidence since the 1960s. Historical records of groundwater extraction, hydraulic head, and land subsidence show the latter to be the result of continual and excessive extraction of groundwater from deep confined aquifers. This study reconstructs land subsidence using an integrated regional groundwater flow and land subsidence model. The model is calibrated using land subsidence and groundwater level measurements from 1996 to 2007. Simulation results reproduce the cones of depression for groundwater heads and nadirs of land subsidence reasonably well. The calibrated model is used to evaluate the efficacy of land subsidence prevention plans from 2008 to 2010, and to predict future land subsidence over the next decade considering several groundwater exploitation scenarios. The results show the main cause of land subsidence to be inelastic compaction of the aquifer system resulting from continuously declining water levels. The model reveals that while the area of land subsidence will continue to extend, the rate of this extension may be significantly decreased by reduction of groundwater extraction. If the current land subsidence prevention and reclamation plans are continued and surface water diversion projects implemented, though land subsidence cannot be halted, the rate at which it is occurring can be effectively reduced.

  18. Interpenetrated Cage Structures. (United States)

    Frank, Marina; Johnstone, Mark D; Clever, Guido H


    This Review covers design strategies, synthetic challenges, host-guest chemistry, and functional properties of interlocked supramolecular cages. Some dynamic covalent organic structures are discussed, as are selected examples of interpenetration in metal-organic frameworks, but the main focus is on discrete coordination architectures, that is, metal-mediated dimers. Factors leading to interpenetration, such as geometry, flexibility and chemical makeup of the ligands, coordination environment, solvent effects, and selection of suitable counter anions and guest molecules, are discussed. In particular, banana-shaped bis-pyridyl ligands together with square-planar metal cations have proven to be suitable building blocks for the construction of interpenetrated double-cages obeying the formula [M4 L8 ]. The peculiar topology of these double-cages results in a linear arrangement of three mechanically coupled pockets. This allows for the implementation of interesting guest encapsulation effects such as allosteric binding and template-controlled selectivity. In stimuli-responsive systems, anionic triggers can toggle the binding of neutral guests or even induce complete structural conversions. The increasing structural and functional complexity in this class of self-assembled hosts promises the construction of intelligent receptors, novel catalytic systems, and functional materials. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. Polyetheretherketone (PEEK) cages in cervical applications: a systematic review. (United States)

    Kersten, Roel Frederik Mark Raymond; van Gaalen, Steven M; de Gast, Arthur; Öner, F Cumhur


    Polyetheretherketone (PEEK) cages have been widely used during the past decade in patients with degenerative disorders of the cervical spine. Their radiolucency and low elastic modulus make them attractive attributes for spinal fusion compared with titanium and bone graft. Still, limitations are seen such as pseudoarthrosis, subsidence, and migration of the cages. Limited evidence on the clinical outcome of PEEK cages is found in the literature other than noncomparative cohort studies with only a few randomized controlled trials. To assess the clinical and radiographic outcome of PEEK cages in the treatment of degenerative disc disorders and/or spondylolisthesis in the cervical spine. Systematic review of all randomized controlled trials and prospective and retrospective nonrandomized comparative studies with a minimum follow-up of 6 months and all noncomparative cohort studies with a long-term follow-up of more than 5 years. The primary outcome variable was clinical performance. Secondary outcome variables consisted of radiographic scores. The MEDLINE, EMBASE, and Cochrane Library databases were searched according to the Preferred Reporting Items of Systematic reviews and Meta-Analyses statement and Meta-analysis Of Observational Studies in Epidemiology guidelines. No conflict of interest reported. No funding received. A total of 223 studies were identified, of which 10 studies were included. These comprised two randomized controlled trials, five prospective comparative trials, and three retrospective comparative trials. Minimal evidence for better clinical and radiographic outcome is found for PEEK cages compared with bone grafts in the cervical spine. No differences were found between PEEK, titanium, and carbon fiber cages. Future studies are needed to improve methodology to minimize bias. Publication of lumbar interbody fusion studies needs to be promoted because differences in clinical and/or radiographic scores are more likely to be demonstrated in this part

  20. Towards a global land subsidence map


    G. Erkens; G. Erkens; E. H. Sutanudjaja; E. H. Sutanudjaja


    Land subsidence is a global problem, but a global land subsidence map is not available yet. Such map is crucial to raise global awareness of land subsidence, as land subsidence causes extensive damage (probably in the order of billions of dollars annually). With the global land subsidence map relative sea level rise predictions may be improved, contributing to global flood risk calculations. In this paper, we discuss the approach and progress we have made so far in ma...

  1. Cage-based performance capture

    CERN Document Server

    Savoye, Yann


    Nowadays, highly-detailed animations of live-actor performances are increasingly easier to acquire and 3D Video has reached considerable attentions in visual media production. In this book, we address the problem of extracting or acquiring and then reusing non-rigid parametrization for video-based animations. At first sight, a crucial challenge is to reproduce plausible boneless deformations while preserving global and local captured properties of dynamic surfaces with a limited number of controllable, flexible and reusable parameters. To solve this challenge, we directly rely on a skin-detached dimension reduction thanks to the well-known cage-based paradigm. First, we achieve Scalable Inverse Cage-based Modeling by transposing the inverse kinematics paradigm on surfaces. Thus, we introduce a cage inversion process with user-specified screen-space constraints. Secondly, we convert non-rigid animated surfaces into a sequence of optimal cage parameters via Cage-based Animation Conversion. Building upon this re...

  2. Risk factors for postoperative subsidence of single-level anterior cervical discectomy and fusion: the significance of the preoperative cervical alignment. (United States)

    Lee, Young-Seok; Kim, Young-Baeg; Park, Seung-Won


    Retrospective cohort study. To investigate and analyze the preoperative risk factors affecting subsidence after anterior cervical discectomy and fusion (ACDF) to reduce subsidence. Subsidence after ACDF may be caused by various risk factors, although the related information is scarce. Seventy-eight patients who underwent single-level ACDF between 2005 and 2011 were included. Patients were categorized into the subsidence (n = 26) and nonsubsidence groups (n = 52). Preoperative factors such as age, sex, operative level, bone mineral density, cervical alignment, segmental sagittal angle, and anterior/posterior disc height were assessed. The use of plates and the anterior/posterior disc height gap were examined as perioperative factors. The clinical outcome was assessed using a visual analogue scale for neck and arm pain. Subsidence occurred in 26 (33.3%) of 78 patients. A significant difference was found in clinical outcomes between the subsidence and nonsubsidence groups (P subsidence group. The mean time to subsidence was 4.8 months. Logistic regression analysis revealed that cervical alignment (P = 0.017), age (P = 0.022), and use of plates (P = 0.041) affected subsidence. In patients who received a stand-alone cage, the risk of subsidence was significantly greater in the kyphotic angle group than in the lordotic angle group (odds ratio = 13.56; P subsidence are cervical alignment, age, and use of plates. Our data suggest that surgeons should consider the kyphotic curvature and/or age when deciding on the use of plates.


    Directory of Open Access Journals (Sweden)

    Luís Eduardo Carelli Teixeira da Silva


    Full Text Available ABSTRACT Objective: Analysis of the use of polyetheretherketone (PEEK cages for atlantoaxial facet realignment and distraction for treatment of basilar invagination by Goel technique. Method: Retrospective descriptive statistical analysis of the neurological status, pain, presence of subsidence and bone fusion with the use of PEEK cages in 8 atlantoaxial joints of 4 patients with basilar invagination. All patients were treated with atlantoaxial facet distraction and realignment and subsequent arthrodesis C1-C2 by the technique of Goel modified by the use of PEEK cage. Results: All patients showed improvement in Nurick neurological assessment scale and Visual Analogue Scale (VAS of pain. There were no cases of subsidence, migration, or damage to the vertebral artery during the insertion of the cage. All joints evolved with bone fusion, assessed by dynamic radiographs, and computed tomography. Two patients developed neuropathic pain in dermatome of C2 and one patient had unilateral vertebral artery injury during C2 instrumentation treated with insertion of pedicle screw to control the bleeding. Conclusion: The results of the treatment of basilar invagination by the Goel technique with the use of PEEK cages shown to be effective and safe although further studies are needed to confirm this use.

  4. Coal mine subsidence and structures

    International Nuclear Information System (INIS)

    Gray, R.E.


    Underground coal mining has occurred beneath 32 x 10 9 m 2 (8 million acres) of land in the United States and will eventually extend beneath 162 x 10 9 m 2 (40 million acres). Most of this mining has taken place and will take place in the eastern half of the United States. In areas of abandoned mines where total extraction was not achieved, roof collapse, crushing of coal pillars, or punching of coal pillars into softer mine floor or roof rock is now resulting in sinkhole or trough subsidence tens or even hundreds of years after mining. Difference in geology, in mining, and building construction practice between Europe and the United States preclude direct transfer of European subsidence engineering experience. Building damage cannot be related simply to tensile and compressive strains at the ground surface. Recognition of the subsidence damage role played by ground-structure interaction and by structural details is needed

  5. Minimally Invasive Transforaminal Lumbar Interbody Fusion: A Comparison Study Based on End Plate Subsidence and Cystic Change in Individuals Older and Younger than 65 Years. (United States)

    Lin, Guang-Xun; Quillo-Olvera, Javier; Jo, Hyun-Jin; Lee, Hyeong-Jin; Covarrubias-Rosas, Claudia Angelica; Jin, Chengzhen; Kim, Jin-Sung


    To compare the outcomes between patients older and younger than 65 years who underwent single-level minimally invasive transforaminal interbody fusion (MI-TLIF) surgery. This study is a retrospective analysis of 76 patients who underwent MI-TLIF between April 2012 and June 2016. Group A consisted of 35 patients (subsidence, end plate cyst formation, and fusion rate were assessed. The mean age of the study subjects was 65.3 years, and the mean duration of follow-up was 18.98 months. Group B had a higher rate of comorbidities compared with group A (90.24% vs. 57.14%, respectively; P subsidence or positive cyst sign between the groups. MI-TLIF presented similar safeness and acceptable outcomes and complication rate in both groups. Cyst formation may be aggravated by cage subsidence, because cage subsidence was a useful potential predictor of cyst formation. Copyright © 2017 Elsevier Inc. All rights reserved.

  6. Land subsidence of coastal areas of Jiangsu Province, China: historical review and present situation

    Directory of Open Access Journals (Sweden)

    J. Q. Zhu


    Full Text Available Surface faults related to land subsidence have been observed in coastal cities, such as Nantong, Yancheng, and Lian Yungang, in Jiangsu Province (CAJS since the early 1970s. Nowadays, increases flooding and rising sea levels are attributed to subsidence caused by groundwater pumping. In this work we present a brief description of land subsidence in CAJS, we examine the mechanisms of land subsidence induced mainly by groundwater pumping and its evolution and economic implications as well as the implemented measures by the local government to prevent new damage.

  7. Land subsidence of coastal areas of Jiangsu Province, China: historical review and present situation (United States)

    Zhu, J. Q.; Yang, Y.; Yu, J.; Gong, X. L.


    Surface faults related to land subsidence have been observed in coastal cities, such as Nantong, Yancheng, and Lian Yungang, in Jiangsu Province (CAJS) since the early 1970s. Nowadays, increases flooding and rising sea levels are attributed to subsidence caused by groundwater pumping. In this work we present a brief description of land subsidence in CAJS, we examine the mechanisms of land subsidence induced mainly by groundwater pumping and its evolution and economic implications as well as the implemented measures by the local government to prevent new damage.

  8. Superior coexistence: systematicALLY regulatING land subsidence BASED on set pair theory

    Directory of Open Access Journals (Sweden)

    Y. Chen


    Full Text Available Anthropogenic land subsidence is an environmental side effect of exploring and using natural resources in the process of economic development. The key points of the system for controlling land subsidence include cooperation and superior coexistence while the economy develops, exploring and using natural resources, and geological environmental safety. Using the theory and method of set pair analysis (SPA, this article anatomises the factors, effects, and transformation of land subsidence. Based on the principle of superior coexistence, this paper promotes a technical approach to the system for controlling land subsidence, in order to improve the prevention and control of geological hazards.

  9. Survey of land subsidence – case study: The land subsidence ...

    Indian Academy of Sciences (India)

    underlying layers' consolidation (Waltman 1989). In addition in the same area, attributes the land. Keywords. Land subsidence; artificial recharge; fine sediments; quality difference of waters. J. Earth Syst. Sci. 124, No. .... of recharge ponds can be an indication of cavities and hollow spaces underground, which have caused.

  10. Survey of land subsidence – case study: The land subsidence ...

    Indian Academy of Sciences (India)

    lineation of ponds land subsidence by tension force in ground surface and formation of cavity and holes in depth. ... of recharge ponds can be an indication of cavities and hollow spaces underground, which have caused .... in this state is subject to the surface tension of water at the contact point with the particles, whose.

  11. Risk evaluation of land subsidence and its application to metro safety operation in Shanghai (United States)

    Liu, J.; Wang, H.; Yan, X.


    Based on sufficiently investigating characteristics and risk connotation of land subsidence, a risk evaluation index system for land subsidence disaster is established, which is combined with the sensitivity feature of the hazard bearing body to land subsidence. An appropriate evaluation method system is established by using an improved fuzzy analytic hierarchy process method. So risk evaluation is developed for providing theoretical basis and technical support for the regional management of land subsidence prevention and control. On this basis, as a case of Shanghai metro, firstly, the paper studies the identifying risk sources of the metro. According to metro linear characteristics, external indexes of representing subsidence risk are obtained. Studying the subsidence risk of the metro, relevant achievement has provided the technical basis for daily main monitoring, early warning and work arrangement.

  12. A Picture of Subsidized Housholds 2008 (United States)

    Department of Housing and Urban Development — Picture of Subsidized Households describes the nearly 5 million households living in HUD-subsidized housing in the United States for the year 2008. Picture 2008...

  13. A Picture of Subsidized Households 2009 (United States)

    Department of Housing and Urban Development — Picture of Subsidized Households describes the nearly 5 million households living in HUD-subsidized housing in the United States for the year 2009. Picture 2009...

  14. Study on the Rule of Super Strata Movement and Subsidence (United States)

    Yao, Shunli; Yuan, Hongyong; Jiang, Fuxing; Chen, Tao; Wu, Peng


    The movement of key strata is related to the safety of the whole earth’s surface for coal mining under super strata. Based on the key strata theory, the paper comprehensively analyzes the characteristics of the subsidence before and after the instability of the super strata by studing through FLAC3D and microseismic dynamic monitoring of the surface rock movement observation. The stability of the super strata movement is analyzed according to the characteristic value of the subsidence. The subsidence law and quantitative indexes under the control of the super rock strata that provides basis for the prevention and control of surface risk, optimize mining area and face layout and reasonably set mining boundary around mining area. It provides basis for the even growth of mine safety production and regional public safety.

  15. Outcomes of interbody fusion cages used in 1 and 2-levels anterior cervical discectomy and fusion: titanium cages versus polyetheretherketone (PEEK) cages. (United States)

    Niu, Chi-Chien; Liao, Jen-Chung; Chen, Wen-Jer; Chen, Lih-Huei


    A prospective study was performed in case with cervical spondylosis who underwent anterior cervical discectomy and fusion (ACDF) with titanium or polyetheretherketone (PEEK) cages. To find out which fusion cage yielded better clinical and radiographic results. Although use of autogenous iliac-bone grafts in ACDF for cervical disc diseases remain standard surgical procedure, donor site morbidity and graft collapse or breakage are concerns. Cage technology was developed to prevent these complications. However, there is no comparison regarding the efficacy between titanium and PEEK cage. January 2005 to January 2006, 53 patients who had 1 and 2-levels ACDF with titanium or PEEK cages were evaluated. We measured the rate and amount of interspace collapse, segmental sagittal angulations, and the radiographic fusion success rate. Odom criteria were used to assess the clinical results. The fusion rate was higher in the PEEK group (100% vs. 86.5%, P=0.0335). There was no significant difference between both groups in loss of cervical lordosis (3.2 + or - 2.4 vs. 2.8 + or - 3.4, P=0.166). The mean anterior interspace collapse (1.6 + or - 1.0 mm) in the titanium group was significantly higher than the collapse of the PEEK group (0.5 + or - 0.6 mm) (PPEEK group (PPEEK group achieved an 80% rate of successful clinical outcomes, compared with 75% in the titanium group (P=0.6642). The PEEK cage is superior to the titanium cage in maintaining cervical interspace height and radiographic fusion after 1 and 2-levels anterior cervical decompression procedures.

  16. Subsidence in Collarless Corail Hip Replacement. (United States)

    Selvaratnam, Veenesh; Shetty, Vishwanath; Sahni, Vishal


    The purpose of this study was to assess whether subsidence occurs in collarless Corail hip replacement (CCHR) and to ascertain the extent and timing of subsidence if present. Retrospective case notes analysis was performed. Sixty eight patients who had CCHR were identified from our database. Male to female ratio was 32:36. Their mean age was 74.2 years (range 37-95 years). Indications for surgery were osteoarthritis in 64 (94%) patients, rheumatoid arthritis in two (3%) patients and avascular necrosis in two (3%) patients. Subsidence was measured at 6 weeks, 6 months and 1 year post-op compared to initial post-op x-rays. At 6 weeks x-ray 21 patients did not have any subsidence, 18 patients had 1 millimeter (mm) subsidence, 10 patients had 2mms subsidence, 4 patients had 3mms subsidence, 5 patients had 4mms subsidence, 1 patient had 5mms subsidence, 4 patients had 6 mms subsidence and 1 patient each had subsidence of 7mms, 9mms, 11mms, 13mms and 26 mms respectively. When compared with 6 months x-rays only 2 patients had a further subsidence of 2mms while another patient had 3mms subsidence. No further subsidence occurred at 1 year follow up x-rays. One patient had revision surgery due to symptomatic subsidence (29mms) at 6 months follow up. Subsidence does occur in the first 6 weeks in collarless Corail hip replacement, and to a lesser extent until 6 months postoperatively, but does not progress further.

  17. Geospatial subsidence hazard modelling at Sterkfontein Caves ...

    African Journals Online (AJOL)

    The geo-hazard subsidence model includes historic subsidence occurrances, terrain (water flow) and water accumulation. Water accumulating on the surface will percolate and reduce the strength of the soil mass, possibly inducing subsidence. Areas for further geotechnical investigation are identified, demonstrating that a ...

  18. Seismic subsidence deformation of moisturised loess




    The results of experimental studies the influence of seismic subsidence on deformation of loess at different accelerations are being described by the author. The methods of laboratory and field studies on soil’s seismic subsidence are provided. The factors affecting the seismic subsidence of the soil deformation are identified.

  19. Generalised empirical method for predicting surface subsidence

    International Nuclear Information System (INIS)

    Zhang, M.; Bhattacharyya, A.K.


    Based on a simplified strata parameter, i.e. the ratio of total thickness of the strong rock beds in an overburden to the overall thickness of the overburden, a Generalised Empirical Method (GEM) is described for predicting the maximum subsidence and the shape of a complete transverse subsidence profile due to a single completely extracted longwall panel. In the method, a nomogram for predicting the maximum surface subsidence is first developed from the data collected from subsidence measurements worldwide. Then, a method is developed for predicting the shapes of complete transfer subsidence profiles for a horizontal seam and ground surface and is verified by case studies. 13 refs., 9 figs., 2 tabs

  20. The use of porous tantalum cages in the treatment of unremitting spondylodiscitis: a case report

    Directory of Open Access Journals (Sweden)

    Samo Karel Fokter


    Full Text Available Background: Unsuccessful medical treatment of pyogenic multifocal spondylodiscitis including signs of sepsis and unremitting pain is challenging. The aim of our report was to present a case of multilevel spondylodiscitis successfully treated by posterior lumbar interbody fusion using porous tantalum cages. Case presentation: A 59-year-old male was diagnosed with spondylodiscitis at T8-T9 level. Although treated with antibiotics, the patient again presented with worsening of systemic signs of infection and back pain. Contrast-enhanced magnetic resonance imaging studies revealed spondylodiscitis at L1 to S1 level. Posterior lumbar interbody bone fusion with tantalum cages from L1 to S1 was performed. The inflammation rapidly subsided. Computer tomography studies showed a stable construct at 24 months. Conclusion: Porous tantalum cages used in combination with transpedicular fixation seem to be a sound alternative to interbody devices made from other materials when treating spondylodiscitis cases without definite osseous destruction.

  1. Impaired bone mineral density as a predictor of graft subsidence following minimally invasive transpsoas lateral lumbar interbody fusion. (United States)

    Tempel, Zachary J; Gandhoke, Gurpreet S; Okonkwo, David O; Kanter, Adam S


    The LLIF procedure is a useful stand-alone and adjunct surgical approach for many spinal conditions. One complication of LLIF is subsidence of the interbody graft into the vertebral bodies, resulting in severe pain, impaired arthrodesis and potentially fracture of the body. Low bone density, as measured by T score on DEXA scanning, has also been postulated to increase the risk of subsidence. A retrospective review of prospectively collected data was performed on all patients who underwent LLIF at this institution consisting of 712 levels in 335 patients. Patients with subsidence following LLIF were recorded. We utilized the T score obtained from the femoral neck DEXA scans, which is used to determine overall fracture risk. The T score of patients with subsidence was compared to those without subsidence. 20 of 57 (35 %) patients without subsidence had a DEXA T score between -1.0 and -2.4 consistent osteopenia, one patient (1.8 %) exhibited a T score less than -2.5, consistent with osteoporosis. 13 patients of 23 (57 %) with subsidence exhibited a T score between -1.0 and -2.4, consistent with osteopenia, five (22 %) exhibited a T score of -2.5 or less, consistent with osteoporosis. The mean DEXA T score in patients with subsidence was -1.65 (SD 1.04) compared to -0.45 (SD 0.97) in patients without subsidence (p subsidence. Further, they are at an increased risk of requiring additional surgery. In patients with poor bone quality, consideration could be made to supplement the LLIF cage with posterior instrumentation.

  2. [The finite element analysis of polyetheretherketone/hydroxyapatite/carbon fiber cage]. (United States)

    Liu, Xueyong; Zhu, Hongxin; Jing, Yanfeng; Sui, Guoxin; Zhang, Zongfu


    To compare the bio-mechanical characteristics of cages of two types, i. e., polyetheretherketone/ hydroxyapatite/carbon fiber (PEEK/HA/CF) and titanium combined with internal pedicle screw fixation in lumbar model, and to provide experimental evidences for clinical application, we constructed a three-dimensional finite element model of an intact L2-L4 segment by using computer tomography scans of a healthy male. The three-dimensional finite element models of an intact L2-L4 segment and single cage plus bilateral vertebral pedicle screw fixation were established. The angular motion of fused segment and stress distribution in the bone graft and cage and L3 inferior endplate under different loads were recorded. The result showed that the peak Von Mises stresses of the bone graft of PEEK/HA/CF group were at least 2.2 time as that of titanium group. The peak Von Mises stresses of L3 inferior endplate of the titanium group were at least 2. 3 times as that of PEEK/HA/CF group. These stresses were concentrated at places where the cage interfaced with the endplate. The angular variation of the titanium group showed similarity to PEEK/HA/CF group. The PEEK/HA/CF cage could provide stability similar to that of titanium cage in the presence of posterior instrumentation. It could increase the load transfer through the bone graft and promote the bone fusion. It could also reduce the stresses in endplates adjacent to the cage and reduce the subsidence of the cage.

  3. The spatiotempora variations rules of Songzao coal mining subsidence based on numerical simulation

    Directory of Open Access Journals (Sweden)

    J. Lu


    affected by the subsidence 2.0 m in 1999 was more than twice the area affected by subsidence in 2004. This in return, it was more than 7 times larger than the area affected by subsidence in 2009 of the one affected by subsidence in 2004. Extent of the area affected by the 2.5 m subsidence has also enlarged rapidly. This area has expanded by about 40 times in 2009 than its value in 2004. In addition, the area of subsidence of value 3.0 m has reached about 0.44 hm2 in 2009 from zero value. Finally, the fifth finding indicated that the overall extend of the mining subsidence was much more serious in southern than in northern side of the Songzao Mine. Moreover, it was indicated that the increasing rate of mining subsidence in the western side of the study area was as bigger as in the eastern side between 1999 and 2009. The spatiotemporal variations rules of songzao coal mining subsidence based on numerical simulation could provide reference for the subsequent subsidence prevention and land consolidation.

  4. Subsidence of topography on Io (United States)

    Webb, Erik K.; Stevenson, David J.


    The underlying roots of Io's topographic features are softened and eroded by contact with the hot mantle, resulting in a subsidence which is analogous to the progress of a butter pat on a frying pan. This process would be offset by crustal thickening due to continuing volcanism if the rate for this phenomenon were more than the observed 1 cm/year or less. Because the crustal thinning would occur at about 50 cm/year if the material underneath were a pure magma ocean, Io cannot have a global magna ocean, and interior viscosities greater than about 10 to the 10th P are implied.

  5. Cage culture of sea bass in Malaysia



    The article discusses the cage culture practice of sea bass (Lates calcarifer) in Malaysia. Problems on feed and seed supply and overcrowding are also discussed. Despite these problems, seabass cage culture still continuously booms.

  6. A Mobile Phone Faraday Cage (United States)

    French, M. M. J.


    A Faraday cage is an interesting physical phenomenon where an electromagnetic wave can be excluded from a volume of space by enclosure with an electrically conducting material. The practical application of this in the classroom is to block the signal to a mobile phone by enclosing it in a metal can. The background of the physics behind this is…

  7. September 2016 Bayou Choctaw Subsidence Report

    Energy Technology Data Exchange (ETDEWEB)

    Moriarty, Dylan Michael [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Lord, Anna C. Snider [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)


    Subsidence monitoring is a crucial component to understanding cavern integrity of salt storage caverns. This report looks at historical and current data at the Bayou Choctaw Strategic Petroleum Reserve Site. Data from the most recent land-based annual surveys, GPS, and tiltmeter indicate the subsidence rates across the site are approximately 0.0 ft./yr. Because of this, there is no evidence from the subsidence survey to suggest any of the DOE caverns have been structurally compromised.

  8. A comparison of anterior cervical discectomy and fusion (ACDF) using self-locking stand-alone polyetheretherketone (PEEK) cage with ACDF using cage and plate in the treatment of three-level cervical degenerative spondylopathy: a retrospective study with 2-year follow-up. (United States)

    Chen, Yuqiao; Lü, Guohua; Wang, Bing; Li, Lei; Kuang, Lei


    To evaluate the clinical efficacy and radiological outcomes of anterior cervical discectomy and fusion (ACDF) using self-locking polyetheretherketone (PEEK) cages for treatment of three-level cervical degenerative spondylopathy. Twenty-eight patients underwent three-level ACDF using self-locking stand-alone PEEK cages (group A), and 26 patients underwent three-level ACDF using cages and plate fixation (group B) were reviewed retrospectively. Clinical efficacy was evaluated by pre- and post-operative Japanese Orthopedic Association (JOA) scores and Neck Disability Index (NDI). The operation time, blood loss, surgical results according to Odom's criteria and post-operative dysphagia status were also recorded. Radiological outcomes including fusion, cervical Cobb's lordosis, fused segment angle, disc height, and cage subsidence were assessed. Clinical outcome measures such as dysphagia and fusion rate and the results of surgery evaluated according to Odom's criteria were not statistically significant (P > 0.05) between groups. The operation time was shorter and blood loss was less in group A (P  0.05). Post-operative cage subsidence, the loss of disc height, cervical lordosis and the fused segment angle were relatively higher in group A than group B (P < 0.05). ACDF using self-locking stand-alone cages showed similar clinical results as compared to ACDF using cages and plate fixation for the treatment of three-level cervical degenerative spondylopathy. However, potential long-term problems such as cage subsidence, loss of cervical lordosis and fused segment angle post-operatively were shown to be associated with patients who underwent ACDF using self-locking stand-alone cages.

  9. Assessing the Land Subsidence Governance in Ningbo City: By a Close Study of the Building Collapse at the Strictly Protected Land Subsidence Area (United States)

    Yu, Xia


    Ningbo is a coastal city in East China, its land subsidence problem was noticed in the 1960s. However, scientific management was insufficient at that time, so with the fast city development from the 1980s, groundwater was used by a large amount of small factories, and tall buildings were built on the land. It was in 2008, scientists predicted that if without doing anything to prevent the land from subsiding, the city will be covered by the East Sea in 2030. From then on, the local government implied several policies, such as shut down most of the groundwater pumping wells, set up a new authority to enhance the cooperation among different administration departments, and also set up a land subsidence monitoring center for the city. Recently, it is declared that a Stereo regulatory system of land subsidence governance has been achieved. However, in 2012, a 23-years old building in the city center collapsed. According to the City Planning 2009, this building is located just in the strictly protected land subsidence area. The experts, however, think that land subsidence is not the main reason, since there are many illegal changes to the building during the past 23 years. The aim of my research is to assess the land subsidence governance in Ningbo city. I studied the collapsed building, how it was built, what has changed after building, how the environment changed in this area, and how this area became the strictly protected land subsidence area, and what kind of protections have been made. Actually, during the case study I discuss the land subsidence governance design of Ningbo, and to see what practices and lessons we can learn from this case.

  10. Protection of pipelines affected by surface subsidence

    International Nuclear Information System (INIS)

    Luo, Y.; Peng, S.S.; Chen, H.J.


    Surface subsidence resulting from underground coal mining can cause problems for buried pipelines. A technique for assessing the level of stress on a subsidence-affected pipeline is introduced. The main contributors to the stress are identified, and mitigation techniques for reducing the stress are proposed. The proposed mitigation techniques were then successfully tested. 13 refs., 8 figs., 2 tabs

  11. Animal Welfare and Food Safety Aspects of Confining Broiler Chickens to Cages. (United States)

    Shields, Sara; Greger, Michael


    In most areas of the world, broiler chickens are raised in floor systems, but cage confinement is becoming more common. The welfare of broiler chickens in cages is affected by movement restriction, poor bone strength due to lack of exercise, and prevention of key behavioral patterns such as dustbathing and ground scratching. Cages for broiler chickens also have a long history of causing skin and leg conditions that could further compromise welfare, but a lack of controlled studies makes it difficult to draw conclusions about newer cage designs. Cage environments are usually stocked at a higher density than open floor systems, and the limited studies available suggest that caging may lead to increased levels of fear and stress in the birds. Further, birds reared on the floor appear less likely to harbor and shed Salmonella, as litter may serve as a seeding agent for competitive exclusion by other microorganisms. Cages for laying hens used in egg production have met with substantial opposition due to welfare concerns and caging broiler chickens will likely be subject to the same kinds of social disapproval.

  12. Coastal subsidence and relative sea level rise (United States)

    Ingebritsen, Steven E.; Galloway, Devin L.


    Subsurface fluid-pressure declines caused by pumping of groundwater or hydrocarbons can lead to aquifer-system compaction and consequent land subsidence. This subsidence can be rapid, as much as 30 cm per year in some instances, and large, totaling more than 13 m in extreme examples. Thus anthropogenic subsidence may be the dominant contributor to relative sea-level rise in coastal environments where subsurface fluids are heavily exploited. Maximum observed rates of human-induced subsidence greatly exceed the rates of natural subsidence of unconsolidated sediments (~0.1–1 cm yr−1) and the estimated rates of ongoing global sea-level rise (~0.3 cm yr−1).

  13. Polymers containing borane or carborane cage compounds and related applications (United States)

    Bowen, III, Daniel E; Eastwood, Eric A


    Polymers comprising residues of cage compound monomers having at least one polyalkoxy silyl substituent are provided. The cage compound monomers are selected from borane cage compound monomers comprising at least 7 cage atoms and/or carborane cage compound monomers comprising 7 to 11 cage compound monomers. Such polymers can further comprise one or more reactive matrices and/or co-monomers covalently bound with the cage compound monomer residues. Articles of manufacture comprising such polymers are also disclosed.

  14. Sex effect in mutual olfactory relationships of individually caged rabbits

    Directory of Open Access Journals (Sweden)

    Alessandro Finzi


    Full Text Available To assess the sex influence on sniffing behavior of rabbits, sets of three rabbits each were located for seven days in contiguous cages divided by a metal wall with holes that prevented the neighboring rabbits to see each other. A buck was located in the central cage, with a doe at each side. Rabbit behavior was video recorded to observe animals sniffing with the muzzle near the wall. The bucks displayed an olfactory preference towards one of the two does, which decreased in few days. The significance was p  0.05. The interest of bucks towards the does was also characterized by a frenetic scratching of the separation wall, contemporary with intense sniffing, displayed only for the first 35 min of the first day. The sniffing behavior of does at the central cage housing the male was not so marked as in bucks, and it progressively changed across the trial (p < 0.01. In conclusion, rabbits establish a transitory sex-oriented olfactory relationship with the conspecifics housed in contiguous cages, which looks no longer necessary once the rabbits have recognized each other.

  15. Land Subsidence International Symposium held in Venice (United States)

    The Third International Symposium on Land Subsidence was held March 18-25, 1984, in Venice, Italy. Sponsors were the Ground-Water Commission of the International Association of Hydrological Sciences (IAHS), the United Nations Educational, Scientific, and Cultural Organization (UNESCO), the Italian National Research Council (CNR), the Italian Regions of Veneto and Emilia-Romagna, the Italian Municipalities of Venice, Ravenna, and Modena, the Venice Province, and the European Research Office. Cosponsors included the International Association of Hydrogeologists (IAH), the International Society for Soil Mechanics and Foundation Engineering (ISSMFE), and the Association of Geoscientists for International Development (AGID).Organized within the framework of UNESCO's International Hydrological Program, the symposium brought together over 200 international interdisciplinary specialists in the problems of land subsidence due to fluid and mineral withdrawal. Because man's continuing heavy development of groundwater, gas, oil, and minerals is changing the natural regime and thus causing more and more subsiding areas in the world, there had been sufficient new land subsidence occurrence, problems, research, and remedial measures since the 1976 Second International Symposium held in Anaheim, California, to develop a most interesting program of nearly 100 papers from about 30 countries. The program consisted of papers covering case histories of fluid and mineral withdrawal, engineering theory and analysis, karst “sink-hole”-type subsidence, subsidence due to dewatering of organic deposits or due to application of water (hydrocompaction), instrumentation, legal, socioeconomic, and environmental effects of land subsidence, and remedial works.

  16. Data Acquisition for Land Subsidence Control (United States)

    Zhu, Y.; Balke, K.


    For controlling land subsidence caused by groundwater over-exploitation, loading of engineered structures, mining and other anthropogenic activities in this fast changing world, a large variety of different data of various scales of concerning areas are needed for scientific study and administrative operational purposes. The economical, social and environmental impacts of anthropogenic land subsidence have long been recognized by many scientific institutions and management authorities based on results of monitoring and analysis at an interdisciplinary level. The land subsidence information systems composed of the surface and subsurface monitoring nets (monitoring and development wells, GPS stations and other facilities) and local data processing centers as a system management tool in Shanghai City was started with the use of GPS technology to monitor land subsidence in 1998. After years of experiences with a set of initiatives by adopting adequate countermeasures, the particular attention given to new improved methodologies to monitor and model the process of land subsidence in a simple and timely way, this is going to be promoted in the whole Yangtze River Delta region in China, where land subsidence expands in the entire region of urban cluster. The Delta land subsidence monitoring network construction aims to establish an efficient and coordinated water resource management system. The land subsidence monitoring network records "living history" of land subsidence, produces detailed scheduled reports and environmental impact statements. For the different areas with local factors and site characteristics, parallel packages need to be designed for predicting changes, land sensitivity and uncertainty analysis, especially for the risk analysis in the rapid growth of megacities and urban areas. In such cases, the new models with new types of local data and the new ways of data acquisition provide the best information for the decision makers for their mitigating

  17. Groundwater-pumping optimization for land-subsidence control in Beijing plain, China (United States)

    Qin, Huanhuan; Andrews, Charles B.; Tian, Fang; Cao, Guoliang; Luo, Yong; Liu, Jiurong; Zheng, Chunmiao


    Beijing, in the North China plain, is one of the few megacities that uses groundwater as its main source of water supply. Groundwater accounts for about two-thirds of the city's water supply, and during the past 50 years the storage depletion from the unconsolidated aquifers underlying the city has been >10.4 billion m3. By 2010, groundwater pumping in the city had resulted in a cumulative subsidence of greater than 100 mm in an area of about 3,900 km2, with a maximum cumulative subsidence of >1,200 mm. This subsidence has caused significant social and economic losses in Beijing, including significant damage to underground utilities. This study was undertaken to evaluate various future pumping scenarios to assist in selecting an optimal pumping scenario to minimize overall subsidence, meet the requirements of the Beijing Land Subsidence Prevention Plan (BLSPP 2013-2020), and be consistent with continued sustainable economic development. A numerical groundwater and land-subsidence model was developed for the aquifer system of the Beijing plain to evaluate land subsidence rates under the possible future pumping scenarios. The optimal pumping scenario consistent with the evaluation constraints is a reduction in groundwater pumping from three major pumping centers by 100, 50 and 20%, respectively, while maintaining an annual pumping rate of 1.9 billion m3. This scenario's land-subsidence rates satisfy the BLSPP 2013-2020 and the pumping scenario is consistent with continued economic development. It is recommended that this pumping scenario be adopted for future land-subsidence management in Beijing.

  18. Specific Internalisation of Gold Nanoparticles into Engineered Porous Protein Cages via Affinity Binding. (United States)

    Paramelle, David; Peng, Tao; Free, Paul; Fernig, David G; Lim, Sierin; Tomczak, Nikodem


    Porous protein cages are supramolecular protein self-assemblies presenting pores that allow the access of surrounding molecules and ions into their core in order to store and transport them in biological environments. Protein cages' pores are attractive channels for the internalisation of inorganic nanoparticles and an alternative for the preparation of hybrid bioinspired nanoparticles. However, strategies based on nanoparticle transport through the pores are largely unexplored, due to the difficulty of tailoring nanoparticles that have diameters commensurate with the pores size and simultaneously displaying specific affinity to the cages' core and low non-specific binding to the cages' outer surface. We evaluated the specific internalisation of single small gold nanoparticles, 3.9 nm in diameter, into porous protein cages via affinity binding. The E2 protein cage derived from the Geobacillus stearothermophilus presents 12 pores, 6 nm in diameter, and an empty core of 13 nm in diameter. We engineered the E2 protein by site-directed mutagenesis with oligohistidine sequences exposing them into the cage's core. Dynamic light scattering and electron microscopy analysis show that the structures of E2 protein cages mutated with bis- or penta-histidine sequences are well conserved. The surface of the gold nanoparticles was passivated with a self-assembled monolayer made of a mixture of short peptidols and thiolated alkane ethylene glycol ligands. Such monolayers are found to provide thin coatings preventing non-specific binding to proteins. Further functionalisation of the peptide coated gold nanoparticles with Ni2+ nitrilotriacetic moieties enabled the specific binding to oligohistidine tagged cages. The internalisation via affinity binding was evaluated by electron microscopy analysis. From the various mutations tested, only the penta-histidine mutated E2 protein cage showed repeatable and stable internalisation. The present work overcomes the limitations of currently

  19. Predictive simulation of the subsidence of venice. (United States)

    Gambolati, G; Gatto, P; Freeze, R A


    Land subsidence at Venice is the result of sediment compaction in the unconsolidated, aquifer-aquitard system that underlies the Venetian Lagoon. Compaction is caused by extensive groundwater withdrawals at the nearby industrial port of Marghera. The total subsidence at Venice for the period from 1930 through 1973 has been about 15 centimeters. Predictive simulations with a calibrated mathematical model were hampered by the sparseness of available data, but, as a first estimate, they suggest that, if withdrawals are kept constant in the future as they have been since 1969, about 3 centimeters of further subsidence can be expected.

  20. Offshore gravimetric and subsidence monitoring

    Energy Technology Data Exchange (ETDEWEB)

    Stenvold, Torkjell


    The introduction (Chapter 1) is complemented by the introductions given in Chapters 2 to 8. I am the first author of the articles in chapter 2 and 8. For the 5 articles in between I am a coauthor, and the sum of my contributions to those articles (as quantified by the respective first authors) represents about one article. Chapter 2 contains the article 'High-precision relative depth and subsidence mapping from seafloor water-pressure measurements' by Stenvold et al. (2006), published in the SPE Journal. It was submitted in March 2005, and a revised version that also contained results from the Troll 2005 survey (August) was submitted in February 2006. The method of obtaining high-precision relative depth measurements by the use of mobile pressure gauges is presented. Intra-survey and inter-survey depth repeatabilities from six surveys are presented, and the individual contributing errors are discussed and estimated. Average reservoir compressibility for the Troll field between 2002 and 2005 is obtained by matching measured subsidence with modeled subsidence. Chapter 3 contains the article 'A new seafloor gravimeter' by Sasagawa et al. (2003), published in Geophysics. It was submitted in September 2001, and a revised version was submitted in August 2002. This article describes the ROVDOG (Remotely operated Vehicledeployed Deep-Ocean Gravimeter) in detail. Gravity and pressure repeatability results from the two first Troll surveys in 1998 and 2000 are presented. Data reduction, instrumental and environmental corrections are also presented. Chapter 4 contains the article 'Precision of seafloor gravity and pressure measurements for reservoir monitoring' by Zumberge et al., and was submitted 29 February 2008 to Geophysics. This builds on the article by Sasagawa et al. (Chapter 3). Improvements and upto date intra- and inter survey repeatability results are presented. The emphasis is on gravity results since the relative depth measurements

  1. Listening to Cage: Nonintentional philosophy and music

    Directory of Open Access Journals (Sweden)

    Richard Fleming


    Full Text Available Listening to Cage: Nonintentional Philosophy and Music threads together the writings of ordinary language philosophy and the music of John Cage, responding specifically to requests made by Cage and Stanley Cavell. While many texts downplay or ignore the philosophical demands in Cage’s music and other texts find grandiose spiritual and philosophical material tied to his work, this text rejects both efforts. It challenges the basic directions of the growing secondary source material on Cage, finding it largely contrary to what Cage himself and his music teaches. That secondary material constantly offers an intentional approach to the music which is to make Cage understandable or easier to understand. The present text makes him appropriately difficult and basically unapproachable, asking the reader for serious acknowledgment of what Cage says he does, namely, “I have nothing to say and I am saying it.” While there is little hope of stopping the Cage industry that academia and publishers have grown, this text wishes at least to try to slow it down. The footnotes of this text include direct conversation material with Cage from the 1980s and 1990s regarding many subjects—his own compositions, our life struggles, remarks on Wittgenstein, Thoreau, philosophy, and music—all with a new context for their hearing.

  2. Subsidence in Collarless Corail Hip Replacement


    Selvaratnam, Veenesh; Shetty, Vishwanath; Sahni, Vishal


    The purpose of this study was to assess whether subsidence occurs in collarless Corail hip replacement (CCHR) and to ascertain the extent and timing of subsidence if present. Retrospective case notes analysis was performed. Sixty eight patients who had CCHR were identified from our database. Male to female ratio was 32:36. Their mean age was 74.2 years (range 37-95 years). Indications for surgery were osteoarthritis in 64 (94%) patients, rheumatoid arthritis in two (3%) patients and avascular...

  3. Review: Regional land subsidence accompanying groundwater extraction (United States)

    Galloway, Devin L.; Burbey, Thomas J.


    The extraction of groundwater can generate land subsidence by causing the compaction of susceptible aquifer systems, typically unconsolidated alluvial or basin-fill aquifer systems comprising aquifers and aquitards. Various ground-based and remotely sensed methods are used to measure and map subsidence. Many areas of subsidence caused by groundwater pumping have been identified and monitored, and corrective measures to slow or halt subsidence have been devised. Two principal means are used to mitigate subsidence caused by groundwater withdrawal—reduction of groundwater withdrawal, and artificial recharge. Analysis and simulation of aquifer-system compaction follow from the basic relations between head, stress, compressibility, and groundwater flow and are addressed primarily using two approaches—one based on conventional groundwater flow theory and one based on linear poroelasticity theory. Research and development to improve the assessment and analysis of aquifer-system compaction, the accompanying subsidence and potential ground ruptures are needed in the topic areas of the hydromechanical behavior of aquitards, the role of horizontal deformation, the application of differential synthetic aperture radar interferometry, and the regional-scale simulation of coupled groundwater flow and aquifer-system deformation to support resource management and hazard mitigation measures.

  4. 30 CFR 784.20 - Subsidence control plan. (United States)


    ... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Subsidence control plan. 784.20 Section 784.20... Subsidence control plan. (a) Pre-subsidence survey. Each application must include: (1) A map of the permit... authority, showing the location and type of structures and renewable resource lands that subsidence may...


    The guide provides instructions for using the Coating Alternatives GuidE (CAGE) software program, version 1.0. It assumes that the user is familiar with the fundamentals of operating an IBM-compatible personal computer (PC) under the Microsoft disk operating system (MS-DOS). CAGE...

  6. Jules Verne's Metaphor of the Iron Cage

    NARCIS (Netherlands)

    Ossewaarde, Marinus R.R.


    Max Weber's concept of the iron cage has become a byword in the scholarly world since the publication in 1930 of Talcott Parsons’ translation of The Protestant Ethic and the Spirit of Capitalism. What is less well-known is that Jules Verne had earlier used the iron cage metaphor in Twenty Thousand

  7. Integrating wireless sensor network for monitoring subsidence phenomena (United States)

    Marturià, Jordi; Lopez, Ferran; Gigli, Giovanni; Intrieri, Emanuele; Mucchi, Lorenzo; Fornaciai, Alessandro


    An innovative wireless sensor network (WSN) for the 3D superficial monitoring of deformations (such as landslides and subsidence) is being developed in the frame of the Wi-GIM project (Wireless sensor network for Ground Instability Monitoring - LIFE12 ENV/IT/001033). The surface movement is detected acquiring the position (x, y and z) by integrating large bandwidth technology able to detect the 3D coordinates of the sensor with a sub-meter error, with continuous wave radar, which allows decreasing the error down to sub-cm. The Estació neighborhood in Sallent is located over the old potassium mine Enrique. This zone has been affected by a subsidence process over more than twenty years. The implementation of a wide network for ground auscultation has allowed monitoring the process of subsidence since 1997. This network consists of: i) a high-precision topographic leveling network to control the subsidence in surface; ii) a rod extensometers network to monitor subsurface deformation; iii) an automatic Leica TCA Total Station to monitor building movements; iv) an inclinometers network to measure the horizontal displacements on subsurface and v) a piezometer to measure the water level. Those networks were implemented within an alert system for an organized an efficient response of the civil protection authorities in case of an emergency. On 23rd December 2008, an acceleration of subsoil movements (of approx. 12-18 cm/year) provoked the activation of the emergency plan by the Catalan Civil Protection. This implied the preventive and scheduled evacuation of the neighbours (January 2009) located in the area with a higher risk of collapse: around 120 residents of 43 homes. As a consequence, the administration implemented a compensation plan for the evacuation of the whole neighbourhood residents and the demolition of 405 properties. In this work, the adaptation and integration process of Wi-GIM system with those conventional monitoring network are presented for its testing

  8. Robust processing of mining subsidence monitoring data

    Energy Technology Data Exchange (ETDEWEB)

    Wang Mingzhong; Huang Guogang [Pingdingshan Mining Bureau (China); Wang Yunjia; Guogangli [China Univ. of Mining and Technology, Xuzhou (China)


    Since China began to do research on mining subsidence in 1950s, more than one thousand lines have been observed. Yet, monitoring data sometimes contain quite a lot of outliers because of the limit of observation and geological mining conditions. In China, nowdays, the method of processing mining subsidence monitoring data is based on the principle of the least square method. It is possible to produce lower accuracy, less reliability, or even errors. For reason given above, the authors, according to Chinese actual situation, have done some research work on the robust processing of mining subsidence monitoring data in respect of how to get prediction parameters. The authors have derived related formulas, designed some computational programmes, done a great quantity of actual calculation and simulation, and achieved good results. (orig.)

  9. November 2016 West Hackberry Subsidence Report

    Energy Technology Data Exchange (ETDEWEB)

    Moriarty, Dylan Michael [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Lord, Anna C. Snider [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)


    Subsidence monitoring is a critical component to understanding the cavern integrity of salt storage caverns. This report looks at historical and recent data from two of the three West Hackberry dome cavern operators. DOE SPR and LA Storage are coordinating subsidence surveys to create a comprehensive understanding of ground movement above the dome. Data from annual level and rod surveys, GPS, and tiltmeter data show the sites are experiencing typical ground movement. The highest subsidence rate is seen in the middle of the DOE SPR site at just under one inch per year with less ground movement around the edge of the site. A GPS and tiltmeter instrument in the northeast areas of the DOE SPR site has not seen any trend change since the devices were installed in 2013. Comparison between recent ground movement data and historical trends suggest that there is no reason to believe that any DOE SPR or LA Storage caverns have been structurally compromised.

  10. Land subsidence measured by satellite radar altimetry (United States)

    Krabill, W. B.; Brooks, R. L.


    Radar altimeter measurements from the GEOS-3 and SEASAT satellites are being evaluated to assess their potential contribution to terrain mapping. The primary evaluation area is the San Joaquin Valley of southern California; 40,000/sq km of the Valley have been mapped at a contour interval of 10 m from the satellite altimeter measurements. The accuracy of the altimeter derived terrain elevations is being assessed by comparison with 1:24,000 and digitized 1:250,000 maps and by intercomparisons at the crossover altimeter intersections. Comparisons of the altimeter derived elevations with historical maps archived at the U.S. Geological Survey confirms the USGS 1926-1972 subsidence contours for this area. Preliminary results from a similar analysis in the Houston-Galveston area of subsidence also demonstrates a capability of measuring land subsidence by satellite altimetry.

  11. Effects of Longwall subsidence on escarpment stability

    International Nuclear Information System (INIS)

    Shea-Albin, V.R.


    Increasing pressure from State and Federal agencies to mitigate mining-induced subsidence damage to overlying structures has presented a unique problem to the coal industry in the western United States. Because sandstone escarpments are an environmental issue, millions of tons of coal reserves that underlie these escarpments risk being classified as unminable by regulatory agencies. At this time, the effect of subsidence on escarpments has not been well documented or characterized. The Bureau of Mines is using numerical modeling techniques to analyze escarpment response to longwall mining. Two- and three-dimensional finite element models have been constructed for a study area near Price, Utah, where longwall panels were mined near an escarpment. This paper includes preliminary results showing that the pattern of subsidence surrounding the escarpment can be simulated through numerical modeling

  12. Subsidence prediction in Estonia's oil shale mines

    International Nuclear Information System (INIS)

    Pastarus, J.R.; Toomik, A.


    This paper analysis the stability of the mining blocks in Estonian oil shale mines, where the room-and-pillar mining system is used. The pillars are arranged in a singular grid. The oil shale bed is embedded at the depth of 40-75 m. The processes in overburden rocks and pillars have caused the subsidence of the ground surface. The conditional thickness and sliding rectangle methods performed calculations. The results are presented by conditional thickness contours. Error does not exceed 4%. Model allows determining the parameters of spontaneous collapse of the pillars and surface subsidence. The surface subsidence parameters will be determined by conventional calculation scheme. Proposed method suits for stability analysis, failure prognosis and monitoring. 8 refs

  13. Subsidence from an artificial permafrost warming experiment. (United States)

    Gelvin, A.; Wagner, A. M.; Lindsey, N.; Dou, S.; Martin, E. R.; Ekblaw, I.; Ulrich, C.; James, S. R.; Freifeld, B. M.; Daley, T. M.; Saari, S.; Ajo Franklin, J. B.


    Using fiber optic sensing technologies (seismic, strain, and temperature) we installed a geophysical detection system to predict thaw subsidence in Fairbanks, Alaska, United States. Approximately 5 km of fiber optic was buried in shallow trenches (20 cm depth), in an area with discontinuous permafrost, where the top of the permafrost is approximately 4 - 4.5m below the surface. The thaw subsidence was enforced by 122 60-Watt vertical heaters installed over a 140 m2 area where seismic, strain, and temperature were continuously monitored throughout the length of the fiber. Several vertical thermistor strings were also recording ground temperatures to a depth of 10 m in parallel to the fiber optic to verify the measurements collected from the fiber optic cable. GPS, Electronic Distance Measurement (EDM) Traditional and LiDAR (Light and Detection and Ranging) scanning were used to investigate the surface subsidence. The heaters were operating for approximately a three month period starting in August, 2016. During the heating process the soil temperatures at the heater element increased from 3.5 to 45 °C at a depth of 3 - 4 m. It took approximately 7 months for the temperature at the heater elements to recover to their initial temperature. The depth to the permafrost table was deepened by about 1 m during the heating process. By the end of the active heating, the surface had subsided approximately 8 cm in the heating section where permafrost was closest to the surface. This was conclusively confirmed with GPS, EDM, and LiDAR. An additional LiDAR survey was performed about seven months after the heaters were turned off (in May 2017). A total subsidence of approximately 20 cm was measured by the end of the passive heating process. This project successfully demonstrates that this is a viable approach for simulating both deep permafrost thaw and the resulting surface subsidence.

  14. Maintenance of a Drosophila melanogaster Population Cage. (United States)

    Caravaca, Juan Manuel; Lei, Elissa P


    Large quantities of DNA, RNA, proteins and other cellular components are often required for biochemistry and molecular biology experiments. The short life cycle of Drosophila enables collection of large quantities of material from embryos, larvae, pupae and adult flies, in a synchronized way, at a low economic cost. A major strategy for propagating large numbers of flies is the use of a fly population cage. This useful and common tool in the Drososphila community is an efficient way to regularly produce milligrams to tens of grams of embryos, depending on uniformity of developmental stage desired. While a population cage can be time consuming to set up, maintaining a cage over months takes much less time and enables rapid collection of biological material in a short period. This paper describes a detailed and flexible protocol for the maintenance of a Drosophila melanogaster population cage, starting with 1.5 g of harvested material from the previous cycle.

  15. Evaluation of cage designs and feeding regimes for honey bee (Hymenoptera: Apidae) laboratory experiments. (United States)

    Huang, Shao Kang; Csaki, Tamas; Doublet, Vincent; Dussaubat, Claudia; Evans, Jay D; Gajda, Anna M; Gregorc, Alex; Hamilton, Michele C; Kamler, Martin; Lecocq, Antoine; Muz, Mustafa N; Neumann, Peter; Ozkirim, Asli; Schiesser, Aygün; Sohr, Alex R; Tanner, Gina; Tozkar, Cansu Ozge; Williams, Geoffrey R; Wu, Lyman; Zheng, Huoqing; Chen, Yan Ping


    The aim of this study was to improve cage systems for maintaining adult honey bee (Apis mellifera L.) workers under in vitro laboratory conditions. To achieve this goal, we experimentally evaluated the impact of different cages, developed by scientists of the international research network COLOSS (Prevention of honey bee COlony LOSSes), on the physiology and survival of honey bees. We identified three cages that promoted good survival of honey bees. The bees from cages that exhibited greater survival had relatively lower titers of deformed wing virus, suggesting that deformed wing virus is a significant marker reflecting stress level and health status of the host. We also determined that a leak- and drip-proof feeder was an integral part of a cage system and a feeder modified from a 20-ml plastic syringe displayed the best result in providing steady food supply to bees. Finally, we also demonstrated that the addition of protein to the bees' diet could significantly increase the level ofvitellogenin gene expression and improve bees' survival. This international collaborative study represents a critical step toward improvement of cage designs and feeding regimes for honey bee laboratory experiments.

  16. Compositions containing borane or carborane cage compounds and related applications (United States)

    Bowen, III, Daniel E; Eastwood, Eric A


    Compositions comprising a polymer-containing matrix and a filler comprising a cage compound selected from borane cage compounds, carborane cage compounds, metal complexes thereof, residues thereof, mixtures thereof, and/or agglomerations thereof, where the cage compound is not covalently bound to the matrix polymer. Methods of making and applications for using such compositions are also disclosed.

  17. Self-Assembled Pyridine-Dipyrrolate Cages. (United States)

    Zhang, Huacheng; Lee, Juhoon; Lammer, Aaron D; Chi, Xiaodong; Brewster, James T; Lynch, Vincent M; Li, Hao; Zhang, Zhan; Sessler, Jonathan L


    An inherently nonlinear pyridine dipyrrolate ligand, namely 2,6-bis(3,4-diethyl-5-carboxy-1H-pyrrol-2yl)pyridine (compound 1), is able to distinguish between different zinc(II) cation sources, namely Zn(acac)2 and Zn(OAc)2, respectively. This differentiation is manifest both in terms of the observed fluorescent behavior in mixed organic media and the reaction chemistry. Treatment of 1 with Zn(acac)2 gives rise to a cage dimer, cage-1, wherein two molecules of compound 1 act as double bridging units to connect two individual cage subunits. As inferred from X-ray crystallographic studies, this cage system consists of discrete zinc dimers with hydroxide bridges that, with the assistance of bound DMF solvent molecules, serve to fix the geometry and orientation of the pyridine dipyrrolate building blocks. When a different zinc source, Zn(OAc)2, is used to carry out an ostensibly similar complexation reaction with compound 1, an acetate-bridged 1D abacus-like cage polymer is obtained as inferred from X-ray diffraction analysis. This extended solid state structure, cage-2, contains individual zinc dimer cage submits and appears stabilized by solvent molecules (DMF) and the counteranion (acetate). Rod-like assemblies are also observed by DLS and SEM. This construct, in contrast to cage-1, proved fluorescent in mixed organic media. The structure of the ligand itself (i.e., in the absence of Zn(II)) was confirmed by X-ray crystallographic analysis and was found to assemble into a supramolecular polymer. Conversion to a dimer form was seen upon the addition of TBAOAc. On the basis of the metric parameters, the structures seen in the solid state are stabilized via hydrogen bonding interactions involving solvent molecules.


    African Journals Online (AJOL)

    A geophysical investigation involving the electrical resistivity and gravity methods was carried out within the premises of a Beverage Factory in Edo State. The investigation was to enable the determination of the cause(s) of a ground subsidence within the premises of the boilers. The vertical electrical sounding interpretation ...

  19. Flooding hazards from sea extremes and subsidence

    DEFF Research Database (Denmark)

    Sørensen, Carlo; Vognsen, Karsten; Broge, Niels


    hazards needs to integrate the water loading from various sources. Furthermore, local subsidence must be accounted for in order to evaluate current and future flooding hazards and management options. We present the methodology (Figure) and preliminary results from the research project “Coastal Flooding...

  20. Semi-analytic modelling of subsidence

    NARCIS (Netherlands)

    Fokker, P.A.; Orlic, B.


    This paper presents a forward model for subsidence prediction caused by extraction of hydrocarbons. The model uses combinations of analytic solutions to the visco-elastic equations, which approximate the boundary conditions. There are only a few unknown parameters to be estimated, and, consequently,

  1. Review of subsidence and stabilization techniques

    International Nuclear Information System (INIS)

    Fernando, D.A.


    In Britain the damage caused by underground coal mining operations approximates to about 100 million pounds Sterling per annum, most of the damage resulting from longwall mining operations. Causes of subsidence can be attributed to the following factors: (1) roof failure (2) pillar failure (3) floor movements. Currently, in Britain, the mining industry is undergoing a state of decline for economic reasons. Consequently, the number of old coal sites available for development schemes has increased. Therefore, the problems associated with subsidence can be segregated into two parts. The first being the mitigation of the effects of subsidence on structures on actively mined areas. The second being the stabilization and rehabilitation of ground over and around old mine sites for new development schemes. In the former case the stabilization techniques employed may be local or global, depending on the problems encountered in any particular area. In the latter case, generally, grouting techniques are employed. This paper aims to review the causes of subsidence and the techniques used to minimize its effect on structures. Also, more economic alternative methods of ground stabilization techniques are described and proposed, to be used in this area of ground engineering

  2. Isotropic thaw subsidence in undisturbed permafrost landscapes (United States)

    Shiklomanov, Nikolay I.; Streletskiy, Dmitry A.; Little, Jonathon D.; Nelson, Frederick E.


    in undisturbed terrain within some regions of the Arctic reveal limited correlation between increasing air temperature and the thickness of the seasonally thawed layer above ice-rich permafrost. Here we describe landscape-scale, thaw-induced subsidence lacking the topographic contrasts associated with thermokarst terrain. A high-resolution, 11 year record of temperature and vertical movement at the ground surface from contrasting physiographic regions of northern Alaska, obtained with differential global positioning systems technology, indicates that thaw of an ice-rich layer at the top of permafrost has produced decimeter-scale subsidence extending over the entire landscapes. Without specialized observation techniques the subsidence is not apparent to observers at the surface. This "isotropic thaw subsidence" explains the apparent stability of active layer thickness records from some landscapes of northern Alaska, despite warming near-surface air temperatures. Integrated over extensive regions, it may be responsible for thawing large volumes of carbon-rich substrate and could have negative impacts on infrastructure.

  3. Thoracic lateral extracavitary corpectomy for anterior column reconstruction with expandable and static titanium cages: clinical outcomes and surgical considerations in a consecutive case series. (United States)

    Holland, Christopher M; Bass, David I; Gary, Matthew F; Howard, Brian M; Refai, Daniel


    Many surgical interventions have emerged as effective means of restoring mechanical stability of the anterior column of the spine. The lateral extracavitary approach (LECA) allows for broad visualization and circumferential reconstruction of the spinal column. However, early reports demonstrated significant complication rates, protracted operative times, and prolonged hospitalizations. More recent reports have highlighted concerns for subsidence, particularly with expandable cages. Our work seeks to describe a single-surgeon consecutive series of patients undergoing LECA for thoracic corpectomy. Specifically, the objective was to explore the surgical considerations, clinical and radiographic outcomes, and complication profile of this approach. A retrospective study examined data from 17 consecutive patients in whom single or multi-level corpectomy was performed via a LECA by a single surgeon. Vertebral body replacement was achieved with either a static or expandable titanium cage. The Karnofsky Performance Scale (KPS) was utilized to assess patient functional status before and after surgery. Radiographic outcomes, particularly footplate-to-body ratio and subsidence, were assessed on CT imaging at 6 weeks after surgery and at follow-up of at least 6 months. The majority of patients had post-operative KPS scores consistent with functional independence (≥70, 12/17 patients, 71%). Fourteen patients had improved or maintained function by last follow-up. In both groups, all patients had a favorable footplate-to-body ratio, and rates of subsidence were similar at both time points. Notably, the overall complication rate (24%) was significantly lower than that published in the literature, and no patient suffered a pneumothorax that required placement of a thoracostomy tube. The LECA approach for anterior column reconstruction with static or expandable cages is an important surgical consideration with favorable surgical parameters and complication rates. Further, use of

  4. Usefulness of polyetheretherketone (PEEK) cage with plate augmentation for anterior arthrodesis in traumatic cervical spine injury. (United States)

    Song, Kyung-Jin; Choi, Byung-Wan; Kim, Gyu-Hyung; Song, Ji-Hun


    Even though many clinical reports about cages have been documented in patients with degenerative disorders, reports were scarce for traumatic injury cases, and those cases using metal cages were restricted to only one-level injury. To evaluate the usefulness of polyetheretherketone (PEEK) cage and plate construction in anterior interbody fusions (AIF) for traumatic cervical spine injuries by analyzing radiographic changes and clinical outcomes. Retrospective study. Fifty-eight patients (91 levels) underwent cage and plate construction for treatment of traumatic cervical spine injury. The fusion rate, fusion time, changes of Cobb angle, subsidence rate, and adjacent level changes were assessed as a radiographic outcome. Clinical analysis includes the recovery rate on the American Spinal Injury Association (ASIA) impairment scale and the presence of the complications. We evaluated 58 patients (91 levels) who underwent surgery and had at least 24 months in follow-up study. Radiographic evaluation included the assessment of interbody fusion rate, fusion time, changes of Cobb angle, subsidence rate, and adjacent level changes. Clinical assessment was done by analyzing recovery state of ASIA impairment scale from preoperative period to the last follow-up and by evaluating complications. Fifty-four cases showed bony fusion within 3 months after the surgery. The mean Cobb angle between the vertebral bodies was 2.54 degrees before operation, 9.13 degrees after operation, and 8.39 degrees at the latest follow-up. The mean intervertebral disc height was increased by 3.01 mm after the operation, but the mean height was 2.17 mm shorter at the last follow-up than after postoperation. In terms of clinical results, five Grade A cases and one Grade B case as assessed by the ASIA impairment scale were unchanged until the last follow-up. Twenty-three cases of Grade C, 16 cases of Grade D, and 13 cases of Grade E improved to seven cases, 26 cases, and 19 cases, respectively. Three

  5. Coral reef evolution on rapidly subsiding margins (United States)

    Webster, J.M.; Braga, J.C.; Clague, D.A.; Gallup, C.; Hein, J.R.; Potts, D.C.; Renema, W.; Riding, R.; Riker-Coleman, K.; Silver, E.; Wallace, L.M.


    A series of well-developed submerged coral reefs are preserved in the Huon Gulf (Papua New Guinea) and around Hawaii. Despite different tectonics settings, both regions have experienced rapid subsidence (2-6??m/ka) over the last 500??ka. Rapid subsidence, combined with eustatic sea-level changes, is responsible for repeated drowning and backstepping of coral reefs over this period. Because we can place quantitative constraints on these systems (i.e., reef drowning age, eustatic sea-level changes, subsidence rates, accretion rates, basement substrates, and paleobathymetry), these areas represent unique natural laboratories for exploring the roles of tectonics, reef accretion, and eustatic sea-level changes in controlling the evolution of individual reefs, as well as backstepping of the entire system. A review of new and existing bathymetric, radiometric, sedimentary facies and numerical modeling data indicate that these reefs have had long, complex growth histories and that they are highly sensitive, recording drowning not only during major deglaciations, but also during high-frequency, small-amplitude interstadial and deglacial meltwater pulse events. Analysis of five generalized sedimentary facies shows that reef drowning is characterized by a distinct biological and sedimentary sequence. Observational and numerical modeling data indicate that on precessional (20??ka) and sub-orbital timescales, the rate and amplitude of eustatic sea-level changes are critical in controlling initiation, growth, drowning or sub-aerial exposure, subsequent re-initiation, and final drowning. However, over longer timescales (> 100-500??ka) continued tectonic subsidence and basement substrate morphology influence broad scale reef morphology and backstepping geometries. Drilling of these reefs will yield greatly expanded stratigraphic sections compared with similar reefs on slowly subsiding, stable and uplifting margins, and thus they represent a unique archive of sea-level and climate

  6. Subsidence Contours for South Louisiana; UTM 15N NAD83; LRA (2005); [subsidence_contours (United States)

    Louisiana Geographic Information Center — The GIS data shapefile represents average subsidence contour intervals (0.02 cm/year over 10,000 years) for Coastal LA derived from the following: Kulp, M.A., 2000,...

  7. Numerical analysis to determine the impact of land subsidence on high-speed railway routes in Beijing, China

    Directory of Open Access Journals (Sweden)

    C. Ye


    Full Text Available More than 10 high-speed railway routes with top speeds of 300 km h−1 are expected to be operational from Beijing by the year 2020. However, the safety of these routes is affected by the occurrence of land subsidence. This paper focuses on the Beijing–Tianjin Intercity High-Speed Railway (BTR, the first high-speed railway in China, to analyze the operational safety of high-speed railway routes by analyzing both regional land subsidence and local differential subsidence caused by groundwater drawing. The Beijing construction stratum is mainly composed of cohesive soil, and the BTR has a maximum accumulative subsidence of > 800 mm and a maximum subsidence rate of > 80 mm a−1. In this paper, finite-element software ABAQUS is used to analyze groundwater drawdown and land subsidence caused by local water drawing, and its effect on the bearing capacity of railway bridge pile foundations and the orbit concrete supporting course. The analysis provides a technical basis for developing prevention and control engineering measures against land subsidence so as to guarantee the safe operation of these high-speed railway routes.

  8. Field cage studies and progressive evaluation of genetically-engineered mosquitoes.

    Directory of Open Access Journals (Sweden)

    Luca Facchinelli

    Full Text Available A genetically-engineered strain of the dengue mosquito vector Aedes aegypti, designated OX3604C, was evaluated in large outdoor cage trials for its potential to improve dengue prevention efforts by inducing population suppression. OX3604C is engineered with a repressible genetic construct that causes a female-specific flightless phenotype. Wild-type females that mate with homozygous OX3604C males will not produce reproductive female offspring. Weekly introductions of OX3604C males eliminated all three targeted Ae. aegypti populations after 10-20 weeks in a previous laboratory cage experiment. As part of the phased, progressive evaluation of this technology, we carried out an assessment in large outdoor field enclosures in dengue endemic southern Mexico.OX3604C males were introduced weekly into field cages containing stable target populations, initially at 10:1 ratios. Statistically significant target population decreases were detected in 4 of 5 treatment cages after 17 weeks, but none of the treatment populations were eliminated. Mating competitiveness experiments, carried out to explore the discrepancy between lab and field cage results revealed a maximum mating disadvantage of up 59.1% for OX3604C males, which accounted for a significant part of the 97% fitness cost predicted by a mathematical model to be necessary to produce the field cage results.Our results indicate that OX3604C may not be effective in large-scale releases. A strain with the same transgene that is not encumbered by a large mating disadvantage, however, could have improved prospects for dengue prevention. Insights from large outdoor cage experiments may provide an important part of the progressive, stepwise evaluation of genetically-engineered mosquitoes.

  9. Subsidence as of 12 months after single-level anterior cervical inter-body fusion. Is it related to clinical outcomes? (United States)

    Lee, Chang-Hyun; Kim, Ki-Jeong; Hyun, Seung-Jae; Yeom, Jin S; Jahng, Tae-Ahn; Kim, Hyun-Jib


    Subsidence is a frequent phenomenon in the interbody fusion process in patients with anterior cervical discectomy and fusion (ACDF). There is little evidence of whether subsidence in the cervical spine has any impact on clinical outcomes. The purpose of this study is to investigate the correlation of subsidence and clinical outcomes after ACDF and to consider reasons subsidence might not cause unfavorable clinical outcomes. A total of 158 consecutive patients who underwent single-level ACDF were included. The patients were divided into a subsidence group (S-group) and a no subsidence group (N-group), with subsidence defined as a decrease by ≥3 mm in total intervertebral height (TIH). We analyzed outcomes resulting from subsidence, particularly focusing on clinical outcomes and subsequent global and segmental kyphosis using a repeated measure analysis of variance (RM-ANOVA). Subsidence occurred in 74 patients (46.8%) as of a 12-month follow-up. The S-group included 58.6% with a stand-alone cage for interbody fusion (p = 0.002). Clinical outcomes improved significantly over time (neck pain, RM-ANOVA: F(1.3, 205) = 125.1, p subsidence and clinical outcomes between the S- and N-group (neck pain, RM-ANOVA: F(2,153) = 1.04, p = 0.356, partial η(2) = 0.229; arm pain, RM-ANOVA: F(2,153) = 0.56, p = 0.571, partial η(2) = 0.142). Segmental angle increased in both groups over time and showed a statistically significant difference between the S- and N-groups (RM-ANOVA: F(3,143) = 6.148, p = 0.001, partial η(2) = 0.959). Although, global cervical angle decreased generally and displayed no statically significant difference between the S- and N-group (RM-ANOVA: F(3,119) = 2.361, p = 0.075, partial η(2) = 0.056). Radiographic subsidence after ACDF occurred in 46.8% patients as of 12 months after the single-level ACDF. The lack of correlation between bad clinical outcome and radiographic subsidence may be due to

  10. Impacts of Climate Change and Land Subsidence on Inundation Risk


    Ching-Nuo Chen; Samkele S. Tfwala


    In this study, a physiographic drainage-inundation model was used to analyse the impacts of land subsidence and climate change on inundation disaster and risk in a land subsidence area. The results indicated that for land subsidence and land subsidence combined with climate change, inundation area, and volume increased under one- and two-day storms for 2-, 5-, 10-, 25-, 50-, 100-, and 200-year return periods. Moreover, locations that originally had high inundation depth showed even greater in...

  11. Comparison of titanium and polyetheretherketone (PEEK) cages in the surgical treatment of multilevel cervical spondylotic myelopathy: a prospective, randomized, control study with over 7-year follow-up. (United States)

    Chen, Yu; Wang, Xinwei; Lu, Xuhua; Yang, Lili; Yang, Haisong; Yuan, Wen; Chen, Deyu


    Anterior cervical discectomy and fusion (ACDF) with titanium- or polyetheretherketone (PEEK)-cage reconstruction is widely used in the treatment of cervical spondylotic myelopathy (CSM). This study was to compare outcomes of titanium and PEEK cages in the treatment of multilevel CSM. Between November 2002 and December 2004, a total of 80 patients with 3-level CSM were randomized in a 1:1 ratio to titanium group and PEEK group. The overall follow-up period of the patients ranged from 86 to 116 months (average 99.7 months). Clinical and radiological results were compared between titanium group and PEEK group. At the final follow-up, the clinical outcomes including JOA score, NDI score, and the excellent and good rates of clinical outcomes in the PEEK group were better than those in the titanium group. More loss of the Cobb angles and the intervertebral height was observed in the titanium group, resulting in the radiological parameters in the titanium group becoming inferior to the PEEK group at the final follow-up. Cage subsidence rates were 34.5 and 5.4% in the titanium and PEEK groups, respectively. Fusion was observed in all patients of two groups at the final follow-up. Two patients presented with cage dislocation without clinical symptoms in the titanium group. In surgical treatment of multilevel CSM, PEEK cage is superior to titanium cage in maintenance of intervertebral height and cervical lordosis, resulting in better clinical outcomes in the long-term follow-up.

  12. The new method of prediction on mining subsidence and deformation

    Energy Technology Data Exchange (ETDEWEB)

    Jiang, Y.; Zhang, Y.; Song, Z.; Sroka, A.; Tian, M. [Shandong University of Science and Technology, Ti' an (China)


    A new probability density function of mining overlying strata and subsidence is put forward that has a general statistical significance based on the ideal stochastic medium displacement model. It establishes a new system of prediction on horizontal mining subsidence and deformation, which gives a new method for prediction of mining subsidence and deformation. 7 refs., 5 figs., 1 tab.

  13. How to deal with subsidence in the Dutch delta?

    NARCIS (Netherlands)

    Stouthamer, E.; Erkens, G.


    In many deltas worldwide subsidence still is an underestimated problem, while the threat posed by land subsidence low-lying urbanizing and urbanized deltas exceeds the threat of sea-level rise induced by climate change. Human-induced subsidence is driven by the extraction of hydrocarbons and

  14. 30 CFR 817.122 - Subsidence control: Public notice. (United States)


    ... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Subsidence control: Public notice. 817.122... ACTIVITIES § 817.122 Subsidence control: Public notice. At least 6 months prior to mining, or within that... subsidence control plan may be examined. [48 FR 24652, June 1, 1983] ...

  15. Structure and dynamics of empty cages in xenon clathrate hydrate. (United States)

    Ikeda-Fukazawa, Tomoko; Yamaguchi, Yohei; Nagashima, Kazushige; Kawamura, Katsuyuki


    We performed molecular dynamics calculations of xenon clathrate hydrate to investigate the effects of empty cages on the structure and dynamics of the surrounding lattice. The distinct structure and dynamics of the empty cages, and cages including Xe, which coexist in the lattice, were analyzed. The results show that the ellipsoidal tetrakaidecahedral cage shrinks along the minor (100) axis and expands along the major (100) axis due to the absence of Xe from the cage, whereas the dodecahedral cage shrinks isotropically. These distortions of the empty cages cause a reduction in the lattice constant and an enhancement of the thermal vibrations of the surrounding lattice. The vibrational density of states shows that the hydrogen bonds consisting of the tetrakaidecahedral cage are strengthened by the absence of Xe, whereas those of the dodecahedral cage are weakened. These results show differing mechanisms of guest-host interaction for the two types of cages including Xe. Repulsion is the dominant guest-host interaction for the dodecahedral cage, as proposed by previous studies. For the tetrakaidecahedral cage, however, attractive interaction is dominant along the major (100) axis, whereas repulsive interaction is dominant along the minor (100) axis. The present results suggest that a small number of empty cages can affect not only the local structures but also the macroscopic properties of the crystal. It is concluded that the distortions of the empty cages are one of the important factors governing the density and phase equilibrium of clathrate hydrates.

  16. Distraction-fusion for caudal cervical spondylomyelopathy using an intervertebral cage and locking plates in 14 dogs. (United States)

    Steffen, Frank; Voss, Katja; Morgan, Joe P


    To evaluate clinical and radiographic outcome in dogs with caudal cervical spondylomyelopathy (CCSM) treated with an intervertebral fusion cage and locking plates. Prospective clinical study. Large breed dogs (n=14) with CCSM. Dogs had single level cervical spine distraction/fusion performed using an intervertebral cage with a hollow center filled with cancellous autograft and 2 ventrally applied locking plates. Outcome was measured using neurologic scores and radiographic interpretation 6 weeks, 6 months, and 12 months postoperatively. The surgical procedure was well tolerated in all dogs. Final outcome at 12 months was available in 9 dogs. Five dogs were judged excellent, 1 dog was good, 2 dogs were satisfactory, and 2 dogs were poor because of adjacent segment disease. Four dogs died for reasons unrelated to the procedure. Radiographically, implants remained stable over the entire follow-up period. The disc space continued to fill with an immature pattern of new bone, which showed progressive increase in opacity and quantity. Subsidence of the cage (median 2 m) was detected in 9 dogs at 6 weeks and remained unchanged in those that could be followed further. Distraction-fusion of single level CCSM in dogs with a combination of intervertebral cage and ventral locking plates is clinically effective and results in successful bony fusion. © Copyright 2011 by The American College of Veterinary Surgeons.

  17. Natural versus anthropogenic subsidence of Venice. (United States)

    Tosi, Luigi; Teatini, Pietro; Strozzi, Tazio


    We detected land displacements of Venice by Persistent Scatterer Interferometry using ERS and ENVISAT C-band and TerraSAR-X and COSMO-SkyMed X-band acquisitions over the periods 1992-2010 and 2008-2011, respectively. By reason of the larger observation period, the C-band sensors was used to quantify the long-term movements, i.e. the subsidence component primarily ascribed to natural processes. The high resolution X-band satellites reveal a high effectiveness to monitor short-time movements as those induced by human activities. Interpolation of the two datasets and removal of the C-band from the X-band map allows discriminating between the natural and anthropogenic components of the subsidence. A certain variability characterizes the natural subsidence (0.9 ± 0.7 mm/yr), mainly because of the heterogeneous nature and age of the lagoon subsoil. The 2008 displacements show that man interventions are responsible for movements ranging from -10 to 2 mm/yr. These displacements are generally local and distributed along the margins of the city islands.

  18. Natural versus anthropogenic subsidence of Venice (United States)

    Tosi, Luigi; Teatini, Pietro; Strozzi, Tazio


    We detected land displacements of Venice by Persistent Scatterer Interferometry using ERS and ENVISAT C-band and TerraSAR-X and COSMO-SkyMed X-band acquisitions over the periods 1992–2010 and 2008–2011, respectively. By reason of the larger observation period, the C-band sensors was used to quantify the long-term movements, i.e. the subsidence component primarily ascribed to natural processes. The high resolution X-band satellites reveal a high effectiveness to monitor short-time movements as those induced by human activities. Interpolation of the two datasets and removal of the C-band from the X-band map allows discriminating between the natural and anthropogenic components of the subsidence. A certain variability characterizes the natural subsidence (0.9 ± 0.7 mm/yr), mainly because of the heterogeneous nature and age of the lagoon subsoil. The 2008 displacements show that man interventions are responsible for movements ranging from −10 to 2 mm/yr. These displacements are generally local and distributed along the margins of the city islands. PMID:24067871

  19. Mine subsidence event at Washington West Apartments

    International Nuclear Information System (INIS)

    Wilson, D.B.; Weber, M.W.; Purdy, J.; Acker, P.


    A major mine subsidence event occurred in Scranton, PA in early 1993. The initial damage included breakage of gas and water lines, cracking of pavements and sidewalks, and architectural damage to the seven-story apartment building that houses about 150 elderly persons. Visible damage include a 3/4-in dilation of the expansion joint separating the building, approximately 200 interior and exterior cracks, and distress to utility lines. The Office of Surface mining Reclamation and Enforcement (OSM) funded an integrated geotechnical and structural engineering investigation to determine the cause of the subsidence, the limits of affected areas, and the nature of damage to the building. Work included interior surveys, exterior surveys, installation of crack gages, eight subsurface borings, review of building design drawings, review of geologic and mining data, and structural analysis of the rigid steel frame building. The surveys showed the building had undergone movements consisting of a lateral translation, a longitudinal differential settlement, and a transverse differential settlement. Preliminary structural analyses showed that the differential settlements had introduced significant additional stresses in some of the building columns. This paper provides a case history of the cause and effects of the subsidence event. The techniques used to collect and analyze the data are presented along with the findings of the geotechnical and structural engineering investigations. The paper also describes emergency actions that were implemented, the remedial alternatives that were considered, and the method selected as the recommended alternative

  20. Instruments for subsurface monitoring of geothermal subsidence

    Energy Technology Data Exchange (ETDEWEB)

    O' Rourke, J.E.; Ranson, B.B.


    The requirements for a subsurface geothermal subsidence instrument were reviewed. Available instruments for monitoring subsurface displacements, both vertical and horizontal, were studied and the most capable instruments identified. Techniques and materials for improving existing or developing new instruments were evaluated. Elements of sensor and signal technology with potential for high temperature monitoring of subsidence were identified. Drawing from these studies, methods to adapt production wells for monitoring were proposed and several new instrumentation systems were conceptually designed. Finally, four instrumentation systems were selected for future development. These systems are: triple sensor induction sensor probe (with casing collar markers); triple sensor gamma ray detector probe (with radioactive markers); triple sensor reed switch probe (with magnet markers); and triple sensor oscillator-type magnet detector probe (with magnet markers). All are designed for use in well casing incorporating slip couplings or bellows sections, although the gamma ray detector probe may also be used in unlined holes. These systems all measure vertical moement. Instruments to measure horizontal displacement due to geothermal subsidence were studied and the required instrument performance was judged to be beyond the state-of-the-art. Thus, no conceptual designs for instruments to monitor horizontal movement are included.

  1. Sea-cage aquaculture, sea lice, and declines of wild fish. (United States)

    Frazer, L Neil


    A sea cage, sometimes referred to as a net pen, is an enclosure designed to prevent farm fish from escaping and to protect them from large predators, while allowing a free flow of water through the cage to carry away waste. Farm fish thus share water with wild fish, which enables transmission of parasites, such as sea lice, from wild to farm and farm to wild fishes. Sea lice epidemics, together with recently documented population-level declines of wild salmon in areas of sea-cage farming, are a reminder that sea-cage aquaculture is fundamentally different from terrestrial animal culture. The difference is that sea cages protect farm fish from the usual pathogen-control mechanisms of nature, such as predators, but not from the pathogens themselves. A sea cage thus becomes an unintended pathogen factory. Basic physical theory explains why sea-cage aquaculture causes sea lice on sympatric wild fish to increase and why increased lice burdens cause wild fish to decline, with extirpation as a real possibility. Theory is important to this issue because slow declines of wild fish can be difficult to detect amid large fluctuations from other causes. The important theoretical concepts are equilibrium, host-density effect, reservoir-host effect, and critical stocking level of farmed fish (stocking level at which lice proliferate on farm fish even if wild fish are not present to infect them). I explored these concepts and their implications without mathematics through examples from salmon farming. I also considered whether the lice-control techniques used by sea-cage farmers (medication and shortened grow-out times) are capable of protecting wild fish. Elementary probability showed that W ≈ W* - εF (where W is the abundance of wild fish, W* is the prefarm abundance, F is the abundance of farm fish, and ε is the ratio of lice per farm fish to lice per wild fish). Declines of wild fish can be reduced by short growing cycles for farm fish, medicating farm fish, and keeping

  2. Depopulation of Caged Layer Hens with a Compressed Air Foam System (United States)

    Gurung, Shailesh; Hoffman, John; Stringfellow, Kendre; Abi-Ghanem, Daad; Zhao, Dan; Caldwell, David; Lee, Jason; Styles, Darrel; Berghman, Luc; Byrd, James; Farnell, Yuhua; Archer, Gregory


    Simple Summary Reportable diseases, such as avian influenza, spread rapidly among poultry, resulting in the death of a large number of birds. Once such a disease has been diagnosed at a farm, infected and susceptible birds are rapidly killed to prevent the spread of the disease. The methods to eliminate infected caged laying hens are limited. An experiment was conducted to study the effectiveness of foam made from compressed air, water, and soap to kill laying hens in cages. The study found that stress levels of the hens killed using compressed air foam in cages to be similar to the hens killed by carbon dioxide or the negative control. Hens exposed to carbon dioxide died earlier as compared to the foam methods. The authors conclude that application of compressed air foam in cages is an alternative to methods such as gas inhalation and ventilation shutdown to rapidly and humanely kill laying hens during epidemics. Abstract During the 2014–2015 US highly pathogenic avian influenza (HPAI) outbreak, 50.4 million commercial layers and turkeys were affected, resulting in economic losses of $3.3 billion. Rapid depopulation of infected poultry is vital to contain and eradicate reportable diseases like HPAI. The hypothesis of the experiment was that a compressed air foam (CAF) system may be used as an alternative to carbon dioxide (CO2) inhalation for depopulating caged layer hens. The objective of this study was to evaluate corticosterone (CORT) and time to cessation of movement (COM) of hens subjected to CAF, CO2 inhalation, and negative control (NEG) treatments. In Experiment 1, two independent trials were conducted using young and spent hens. Experiment 1 consisted of five treatments: NEG, CO2 added to a chamber, a CO2 pre-charged chamber, CAF in cages, and CAF in a chamber. In Experiment 2, only spent hens were randomly assigned to three treatments: CAF in cages, CO2 added to a chamber, and aspirated foam. Serum CORT levels of young hens were not significantly

  3. Laboratory rodent welfare: thinking outside the cage. (United States)

    Balcombe, Jonathan


    This commentary presents the case against housing rats and mice in laboratory cages; the commentary bases its case on their sentience, natural history, and the varied detriments of laboratory conditions. The commentary gives 5 arguments to support this position: (a) rats and mice have a high degree of sentience and can suffer, (b) laboratory environments cause suffering, (c) rats and mice in the wild have discrete behavioral needs, (d) rats and mice bred for many generations in the laboratory retain these needs, and (e) these needs are not met in laboratory cages.

  4. Prevention (United States)

    ... Error processing SSI file About Heart Disease & Stroke Prevention Heart disease and stroke are an epidemic in ... secondhand smoke. Barriers to Effective Heart Disease & Stroke Prevention Many people with key risk factors for heart ...

  5. High-throughput Transcriptome analysis, CAGE and beyond

    KAUST Repository

    Kodzius, Rimantas


    1. Current research - PhD work on discovery of new allergens - Postdoctoral work on Transcriptional Start Sites a) Tag based technologies allow higher throughput b) CAGE technology to define promoters c) CAGE data analysis to understand Transcription - Wo

  6. A new bone surrogate model for testing interbody device subsidence. (United States)

    Au, Anthony G; Aiyangar, Ameet K; Anderson, Paul A; Ploeg, Heidi-Lynn


    An in vitro biomechanical study investigating interbody device subsidence measures in synthetic vertebrae, polyurethane foam blocks, and human cadaveric vertebrae. To compare subsidence measures of bone surrogates with human vertebrae for interbody devices varying in size/placement. Bone surrogates are alternatives when human cadaveric vertebrae are unavailable. Synthetic vertebrae modeling cortices, endplates, and cancellous bone have been developed as an alternative to polyurethane foam blocks for testing interbody device subsidence. Indentors placed on the endplates of synthetic vertebrae, foam blocks, and human vertebrae were subjected to uniaxial compression. Subsidence, measured with custom-made extensometers, was evaluated for an indentor seated either centrally or peripherally on the endplate. Failure force and indentation stiffness were determined from force-displacement curves. Subsidence measures in human vertebrae varied with indentor placement: failure forces were higher and indentors subsided less with peripheral placement. Subsidence measures in foam blocks were insensitive to indentor size/placement; they were similar to human vertebrae for centrally placed but not for peripherally placed indentors. Although subsidence measures in synthetic vertebrae were sensitive to indentor size/placement, failure force and indentation stiffness were overestimated, and subsidence underestimated, for both centrally placed and peripherally placed indentors. The synthetic endplate correctly represented the human endplate geometry, and thus, failure force, stiffness, and subsidence in synthetic vertebrae were sensitive to indentor size/placement. However, the endplate was overly strong and thus synthetic vertebrae did not accurately model indentor subsidence in human cadaveric vertebrae. Foam blocks captured subsidence measures more accurately than synthetic vertebrae for centrally placed indentors, but because of their uniform density were not sufficiently robust to

  7. Pentagonal dodecahedron methane hydrate cage and methanol ...

    Indian Academy of Sciences (India)

    NBO analysis and red shift of vibrational frequency reveal that hydrogen bond formation between methanol and water molecules of 1CH4@512 cage is favourable subsequently after breaking its original hydrogen bonded network. Keywords. Density functional theory; natural bond orbital; red shift of vibrational frequency;.

  8. Design and analysis of roll cage (United States)

    Angadi, Gurusangappa; Chetan, S.


    Wildlife fire fighting vehicles are used to extinguish fires in forests, in this process vehicles face falling objects like rocks, tree branches and other objects. Also due to uneven conditions of the terrain like cliff edges, uneven surfaces etc. makes the vehicle to roll over and these can cause injuries to both the driver and the operator. Roll over of a vehicle is a common incident which makes fatal injuries to the operator and also stands next to the crash accidents. In order to reduce the injury level and continuous roll over of the vehicle it is necessary to equip suitable roll cage according to standards of vehicle. In this present work roll cage for pump operator in wildfire fighting vehicle is designed and analysis is carried out in computer simulated environment when seating position of operator seated outside of the cabin. According to NFPA 1906 standards wildlife fire apparatus, Design and Test procedures that are carried out in Hyperworks maintaining SAE J1194.1983 standards. G load case, roof crush analysis and pendulum impact analysis tests are carried out on roll cage to ensure the saftey of design. These load cases are considerd to satisfy the situation faced in forest terrain. In these test procedures roll cage is analysed for stresses and deformation in various load cases. After recording results these are compared with standards mentioned in SAE J1194.1983.

  9. Computational study of retro Trp-cage

    Czech Academy of Sciences Publication Activity Database

    Vymětal, Jiří; Bathula, S. R.; Žídek, L.; Černý, Jiří; Sklenář, V.; Vondrášek, Jiří


    Roč. 12, č. 1 (2012), s. 54-55 ISSN 1210-8529. [10th Discussions in Structural Molecular Biology . 22.03.2012-24.03.2012, Nové Hrady] Institutional research plan: CEZ:AV0Z40550506; CEZ:AV0Z50520701 Keywords : TRP-cage Subject RIV: CF - Physical ; Theoretical Chemistry

  10. Geomechanics of fracture caging in wellbores

    NARCIS (Netherlands)

    Weijermars, R.; Zhang, X.; Schultz-Ela, D.


    This study highlights the occurrence of so-called ‘fracture cages’ around underbalanced wellbores, where fractures cannot propagate outwards due to unfavourable principal stress orientations. The existence of such cages is demonstrated here by independent analytical and numerical methods. We explain

  11. Pentagonal dodecahedron methane hydrate cage and methanol ...

    Indian Academy of Sciences (India)

    Abstract. Density functional theory based studies have been performed to elucidate the role of methanol as an methane hydrate inhibitor. A methane hydrate pentagonal dodecahedron cage's geometry optimization, natural bond orbital (NBO) analysis, Mullikan charge determination, electrostatic potential evaluation and ...

  12. Porous Organic Cage Thin Films and Molecular-Sieving Membranes. (United States)

    Song, Qilei; Jiang, Shan; Hasell, Tom; Liu, Ming; Sun, Shijing; Cheetham, Anthony K; Sivaniah, Easan; Cooper, Andrew I


    Porous organic cage molecules are fabricated into thin films and molecular-sieving membranes. Cage molecules are solution cast on various substrates to form amorphous thin films, with the structures tuned by tailoring the cage chemistry and processing conditions. For the first time, uniform and pinhole-free microporous cage thin films are formed and demonstrated as molecular-sieving membranes for selective gas separation. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. Subsidence Evolution of the Leizhou Peninsula, China, Based on InSAR Observation from 1992 to 2010

    Directory of Open Access Journals (Sweden)

    Yanan Du


    Full Text Available Over the past two decades, the Leizhou Peninsula has suffered from many geological hazards and great property losses caused by land subsidence. However, the absence of a deformation map of the whole peninsula has impeded the government in making the necessary decisions concerning hazard prevention and mitigation. This study aims to provide the evolution of land deformation (subsidence and uplift in the whole peninsula from 1992 to 2010. A modified stacking procedure is proposed to map the surface deformation with JERS, ENVISAT, and ALOS1 images. The map shows that the land subsidence mainly occurs along the coastline with a maximum velocity of 32 mm/year and in a wide range of inland arable lands with a velocity between 10 and 19 mm/year. Our study suggests that there is a direct correlation between the subsidence and the surface geology. Besides, the observed subsidence in urban areas, caused by groundwater overexploitation for domestic and industrial use, is moving from urban areas to suburban areas. In nonurban areas, groundwater extraction for aquaculture and arable land irrigation are the main reason for land subsidence, which accelerates saltwater intrusion and coastline erosion if regular surface deformation measurements and appropriate management measures are not taken.

  14. Evaluation of mining subsidence using GPS data

    Czech Academy of Sciences Publication Activity Database

    Doležalová, Hana; Kajzar, Vlastimil; Souček, Kamil; Staš, Lubomír


    Roč. 6, č. 3 (2009), s. 359-367 ISSN 1214-9705. [Czech - Polish Workshop on recent geodynamics of the Sudeten and adjacent areas /9./. Náchod, 12.11.2009-15.11.2009] R&D Projects: GA ČR GA105/07/1586 Institutional research plan: CEZ:AV0Z30860518 Keywords : undermining * subsidence depression * tectonic faults Subject RIV: DC - Siesmology, Volcanology, Earth Structure Impact factor: 0.275, year: 2009

  15. Rapid subsidence over oil fields measured by SAR (United States)

    Fielding, E. J.; Blom, R. G.; Goldstein, R. M.


    The Lost Hills and Belridge oil felds are in the San Joaquin Valley, California. The major oil reservoir is high porosity and low permeability diatomite. Extraction of large volumes from shallow depths causes reduction in pore pressure and subsequent compaction, forming a surface subsidence bowl. We measure this subsidence from space using interferometric analysis of SAR (Synthetic Aperture Radar) data collected by the European Space Agency Remote Sensing Satellites (ERS-1 and ERS-2). Maximum subsidence rates are as high as 40 mm in 35 days or > 400 mm/yr, measured from interferograms with time separations ranging from one day to 26 months. The 8- and 26-month interferograms contain areas where the subsidence gradient exceeds the measurement possible with ERS SAR, but shows increased detail in areas of less rapid subsidence. Synoptic mapping of subsidence distribution from satellite data powerfully complements ground-based techniques, permits measurements where access is difficult, and aids identification of underlying causes.

  16. Subsidence over AML and its causes - A case study

    International Nuclear Information System (INIS)

    Peng, S.S.; Lin, P.M.; Hsiung, S.M.


    Subsidence over abandoned mined lands can be attributed to several causes. For purposes of compensation and liability and developing remedial measures, it is essential to identify the real causes. The detailed procedures for a subsidence investigation and the keys to identify and determine the causes and severity of the damages are illustrated and discussed through a case study in this paper. A subsidence check list has been developed for investigation purposes. The case discussed in this paper is a mining-related subsidence. The associated subsidence index was 60%. The damage to the dwelling was due to tension. The major damage was developed within two days. A crackmeter was installed on the exterior wall to monitor the house movement. An inclinometer casing and a Sondex casing were installed in a borehole to monitor the ground movement. The results of the geotechnical instrumentation are presented to illustrate the procedures developed for investigating the subsidence cases over the abandoned mine lands

  17. Numerical Modeling of Mechanical Behavior for Buried Steel Pipelines Crossing Subsidence Strata. (United States)

    Zhang, J; Liang, Z; Han, C J


    This paper addresses the mechanical behavior of buried steel pipeline crossing subsidence strata. The investigation is based on numerical simulation of the nonlinear response of the pipeline-soil system through finite element method, considering large strain and displacement, inelastic material behavior of buried pipeline and the surrounding soil, as well as contact and friction on the pipeline-soil interface. Effects of key parameters on the mechanical behavior of buried pipeline were investigated, such as strata subsidence, diameter-thickness ratio, buried depth, internal pressure, friction coefficient and soil properties. The results show that the maximum strain appears on the outer transition subsidence section of the pipeline, and its cross section is concave shaped. With the increasing of strata subsidence and diameter-thickness ratio, the out of roundness, longitudinal strain and equivalent plastic strain increase gradually. With the buried depth increasing, the deflection, out of roundness and strain of the pipeline decrease. Internal pressure and friction coefficient have little effect on the deflection of buried pipeline. Out of roundness is reduced and the strain is increased gradually with the increasing of internal pressure. The physical properties of soil have a great influence on the mechanical properties of buried pipeline. The results from the present study can be used for the development of optimization design and preventive maintenance for buried steel pipelines.

  18. Numerical Modeling of Mechanical Behavior for Buried Steel Pipelines Crossing Subsidence Strata.

    Directory of Open Access Journals (Sweden)

    J Zhang

    Full Text Available This paper addresses the mechanical behavior of buried steel pipeline crossing subsidence strata. The investigation is based on numerical simulation of the nonlinear response of the pipeline-soil system through finite element method, considering large strain and displacement, inelastic material behavior of buried pipeline and the surrounding soil, as well as contact and friction on the pipeline-soil interface. Effects of key parameters on the mechanical behavior of buried pipeline were investigated, such as strata subsidence, diameter-thickness ratio, buried depth, internal pressure, friction coefficient and soil properties. The results show that the maximum strain appears on the outer transition subsidence section of the pipeline, and its cross section is concave shaped. With the increasing of strata subsidence and diameter-thickness ratio, the out of roundness, longitudinal strain and equivalent plastic strain increase gradually. With the buried depth increasing, the deflection, out of roundness and strain of the pipeline decrease. Internal pressure and friction coefficient have little effect on the deflection of buried pipeline. Out of roundness is reduced and the strain is increased gradually with the increasing of internal pressure. The physical properties of soil have a great influence on the mechanical properties of buried pipeline. The results from the present study can be used for the development of optimization design and preventive maintenance for buried steel pipelines.

  19. Space geodesy: subsidence and flooding in New Orleans. (United States)

    Dixon, Timothy H; Amelung, Falk; Ferretti, Alessandro; Novali, Fabrizio; Rocca, Fabio; Dokka, Roy; Sella, Giovanni; Kim, Sang-Wan; Wdowinski, Shimon; Whitman, Dean


    It has long been recognized that New Orleans is subsiding and is therefore susceptible to catastrophic flooding. Here we present a new subsidence map for the city, generated from space-based synthetic-aperture radar measurements, which reveals that parts of New Orleans underwent rapid subsidence in the three years before Hurricane Katrina struck in August 2005. One such area is next to the Mississippi River-Gulf Outlet (MRGO) canal, where levees failed during the peak storm surge: the map indicates that this weakness could be explained by subsidence of a metre or more since their construction.

  20. Ensemble of ground subsidence hazard maps using fuzzy logic (United States)

    Park, Inhye; Lee, Jiyeong; Saro, Lee


    Hazard maps of ground subsidence around abandoned underground coal mines (AUCMs) in Samcheok, Korea, were constructed using fuzzy ensemble techniques and a geographical information system (GIS). To evaluate the factors related to ground subsidence, a spatial database was constructed from topographic, geologic, mine tunnel, land use, groundwater, and ground subsidence maps. Spatial data, topography, geology, and various ground-engineering data for the subsidence area were collected and compiled in a database for mapping ground-subsidence hazard (GSH). The subsidence area was randomly split 70/30 for training and validation of the models. The relationships between the detected ground-subsidence area and the factors were identified and quantified by frequency ratio (FR), logistic regression (LR) and artificial neural network (ANN) models. The relationships were used as factor ratings in the overlay analysis to create ground-subsidence hazard indexes and maps. The three GSH maps were then used as new input factors and integrated using fuzzy-ensemble methods to make better hazard maps. All of the hazard maps were validated by comparison with known subsidence areas that were not used directly in the analysis. As the result, the ensemble model was found to be more effective in terms of prediction accuracy than the individual model.

  1. Impacts of 25 years of groundwater extraction on subsidence ... (United States)

    Many major river deltas in the world are subsiding and consequently become increasingly vulnerable to flooding and storm surges, salinization and permanent inundation. For the Mekong Delta, annual subsidence rates up to several centimetres have been reported. Excessive groundwater extraction is suggested as the main driver. As groundwater levels drop, subsidence is induced through aquifer compaction. Over the past 25 years, groundwater exploitation has increased dramatically, transforming the delta from an almost undisturbed hydrogeological state to a situation with increasing aquifer depletion. Yet the exact contribution of groundwater exploitation to subsidence in the Mekong delta has remained unknown. In this study we deployed a delta-wide modelling approach, comprising a 3D hydrogeological model with an integrated subsidence module. This provides a quantitative spatially-explicit assessment of groundwater extraction-induced subsidence for the entire Mekong delta since the start of widespread overexploitation of the groundwater reserves. We find that subsidence related to groundwater extraction has gradually increased in the past decades with highest sinking rates at present. During the past 25 years, the delta sank on average ~18 cm as a consequence of groundwater withdrawal. Current average subsidence rates due to groundwater extraction in our best estimate model amount to 1.1 cm yr−1, with areas subsiding over 2.5 cm yr−1, outpacing global sea level ri

  2. Use of Cemented Super-Fine Unclassified Tailings Backfill for Control of Subsidence


    Lei Yang; Jingping Qiu; Haiqiang Jiang; Shiqiang Hu; Hao Li; Songbo Li


    Known for its advantages in preventing geological and environmental hazards, cemented paste backfill (CPB) has become a topic of interest for scientists and mining engineers in recent decades. This paper presents the results of a study on the use of cemented super-fine tailings backfill (CSUTB) in an underground mine for control of surface subsidence. An analytical solution is developed based on the available model to calculate the required strength of backfill when in contact with non-cement...

  3. Posterior-only approach for lumbar vertebral column resection and expandable cage reconstruction for spinal metastases. (United States)

    Jandial, Rahul; Kelly, Brandon; Chen, Mike Yue


    remained paraparetic after the surgery. No patients had lasting intraoperative neuromonitoring changes, and none died. Complications included 2 reoperations, 1 delayed hardware failure (cage subsidence that did not require revision), and 3 incidental durotomies (none of which required reoperation). No postoperative pneumonia, ileus, or deep venous thrombosis developed in any patient. A posterior-only approach for vertebral segment resection with preservation of spinal nerve roots is a viable technique that can be used throughout the entire lumbar spine. Extensive mobilization of the nerve roots is of utmost importance and allows for insertion and expansion of medium-sized, in situ expandable cages in the midline. This approach, although technically challenging, might reduce the morbidity associated with an anterior approach.

  4. Specific Internalisation of Gold Nanoparticles into Engineered Porous Protein Cages via Affinity Binding (United States)

    Peng, Tao; Free, Paul; Fernig, David G.; Lim, Sierin; Tomczak, Nikodem


    Porous protein cages are supramolecular protein self-assemblies presenting pores that allow the access of surrounding molecules and ions into their core in order to store and transport them in biological environments. Protein cages’ pores are attractive channels for the internalisation of inorganic nanoparticles and an alternative for the preparation of hybrid bioinspired nanoparticles. However, strategies based on nanoparticle transport through the pores are largely unexplored, due to the difficulty of tailoring nanoparticles that have diameters commensurate with the pores size and simultaneously displaying specific affinity to the cages’ core and low non-specific binding to the cages’ outer surface. We evaluated the specific internalisation of single small gold nanoparticles, 3.9 nm in diameter, into porous protein cages via affinity binding. The E2 protein cage derived from the Geobacillus stearothermophilus presents 12 pores, 6 nm in diameter, and an empty core of 13 nm in diameter. We engineered the E2 protein by site-directed mutagenesis with oligohistidine sequences exposing them into the cage’s core. Dynamic light scattering and electron microscopy analysis show that the structures of E2 protein cages mutated with bis- or penta-histidine sequences are well conserved. The surface of the gold nanoparticles was passivated with a self-assembled monolayer made of a mixture of short peptidols and thiolated alkane ethylene glycol ligands. Such monolayers are found to provide thin coatings preventing non-specific binding to proteins. Further functionalisation of the peptide coated gold nanoparticles with Ni2+ nitrilotriacetic moieties enabled the specific binding to oligohistidine tagged cages. The internalisation via affinity binding was evaluated by electron microscopy analysis. From the various mutations tested, only the penta-histidine mutated E2 protein cage showed repeatable and stable internalisation. The present work overcomes the limitations of

  5. Prevention (United States)

    ... Contact Aging & Health A to Z Find a Geriatrics Healthcare Professional Medications & Older Adults Making Your Wishes ... Prevention Hearing Loss Heart Attack High Blood Pressure Nutrition Osteoporosis Shingles Skin Cancer Related News Quitting Smoking, ...

  6. Groundwater-Mining-Induced Subsidence and Earth Fissures in Cedar Valley, Southwestern Utah (United States)

    Knudsen, T. R.; Inkenbrandt, P.; Lund, W. R.; Lowe, M.; Bowman, S. D.


    Groundwater pumping in excess of recharge (groundwater mining) has lowered the potentiometric surface in Cedar Valley, southwestern Utah, by as much as 114 feet since 1939. Lowering the potentiometric surface (head decline) has caused permanent compaction of fine-grained sediments of the Cedar Valley aquifer. Recently acquired interferometric synthetic aperture radar (InSAR) imagery shows that land subsidence is occurring over an ~100 square-mile area, including two pronounced subsidence bowls in the northeastern (Enoch graben) and southwestern (Quichapa Lake area) parts of the valley. A lack of accurate historical benchmark elevation data over much of the valley prevents detailed long-term quantification of subsidence. In response to the land subsidence, earth fissures have formed along the margins of the Enoch graben and north and west of Quichapa Lake. Our initial inventory of Cedar Valley fissures, which relied on aerial-photography analysis, identified 3.9 miles of fissures in 2009. With newly acquired light detection and ranging (LiDAR) coverage in 2011, we more than doubled the total length of mapped fissures to 8.3 miles. Fissures on the west side of the Enoch graben exhibit ongoing vertical surface displacement with rates as high as 1.7 inches/year. The largest Enoch-graben-west fissure has displaced street surfaces, curb and gutter, and sidewalks, and has reversed the flow direction of a sewer line in a partially developed subdivision. Several Cedar Valley fissures are closely associated with, and in some places coincident with, mapped Quaternary faults. While the majority of Cedar Valley fissures are mapped in agricultural areas, continued groundwater mining and resultant subsidence will likely cause existing fissures to lengthen and new fissures to form that may eventually impact other developed areas of the valley.

  7. Comparative Fixation and Subsidence Profiles of Cementless Unicompartmental Knee Arthroplasty Implants. (United States)

    Yildirim, Gokce; Gopalakrishnan, Ananthkrishnan; Davignon, Robert A; Parker, John W; Chawla, Harshvardhan; Pearle, Andrew D


    Aseptic loosening is the primary cause of failure for both cemented and cementless unicondylar knee replacements (UKRs). Micromotion and subsidence of tibial baseplate are two causes of failure, due to poor fixation and misalignment, respectively. Stair ascent activity profiles from Bergmann et al and Li et al were used. Biphasic Sawbones models were prepared according to the surgical techniques of traditional and novel cementless UKRs. Implants were tested for 10,000 cycles representing post-operative bone interdigitation period, and micromotion was observed using speckle pattern measurements, which demonstrated sufficient resolution. Additionally, the test method proposed by Liddle et al was used to measure subsidence with pressure sensors under increasingly lateralized loading. Mean displacement due to micromotion for mediolateral and anteroposterior plane was consistently greater for traditional cementless UKR. Mean displacement for axial micromotion was significantly higher for traditional UKR at the anterior aspect of the implant; however, values were lower for the medial periphery of the implant. Subsidence was significantly lower for the novel design with increasingly lateralized loading, and indentation was not observed on the test substrate, when compared to the traditional design. Our findings demonstrate that the novel cementless design is capable of fixation and elimination of subsidence in laboratory test settings. Both designs limit micromotion to below the established loosening micromotion value of 150 μm. The L-shaped keel design resists both micromotion and subsidence and may prevent failure modes that can lead to aseptic loosening for UKRs. These findings are highly relevant for clinical application. Copyright © 2016 Elsevier Inc. All rights reserved.

  8. Production induced subsidence and seismicity in the Groningen gas field - can it be managed? (United States)

    de Waal, J. A.; Muntendam-Bos, A. G.; Roest, J. P. A.


    Reliable prediction of the induced subsidence resulting from gas production is important for a near sea level country like the Netherlands. Without the protection of dunes, dikes and pumping, large parts of the country would be flooded. The predicted sea-level rise from global warming increases the challenge to design proper mitigation measures. Water management problems from gas production induced subsidence can be prevented if measures to counter its adverse effects are taken timely. This requires reliable subsidence predictions, which is a major challenge. Since the 1960's a number of large, multi-decade gas production projects were started in the Netherlands. Extensive, well-documented subsidence prediction and monitoring technologies were applied. Nevertheless predicted subsidence at the end of the Groningen field production period (for the centre of the bowl) went from 100 cm in 1971 to 77 cm in 1973 and then to 30 cm in 1977. In 1984 the prediction went up again to 65 cm, down to 36 cm in 1990 and then via 38 cm (1995) and 42 cm (2005) to 47 cm in 2010 and 49 cm in 2013. Such changes can have large implications for the planning of water management measures. Until 1991, when the first event was registered, production induced seismicity was not observed nor expected for the Groningen field. Thereafter the number of observed events rose from 5 to 10 per year during the 1990's to well over a hundred in 2013. The anticipated maximum likely magnitude rose from an initial value of less than 3.0 to a value of 3.3 in 1993 and then to 3.9 in 2006. The strongest tremor to date occurred near the village of Huizinge in August 2012. It had a magnitude of 3.6, caused significant damage and triggered the regulator into an independent investigation. Late 2012 it became clear that significantly larger magnitudes cannot be excluded and that values up to magnitude 5.0 cannot be ruled out. As a consequence the regulator advised early 2013 to lower Groningen gas production by as

  9. Problem of calculating dynamic ground subsidence resulting from mining operations

    Energy Technology Data Exchange (ETDEWEB)

    Schober, F.; Sroka, A.; Sroka, T.


    The fundamentals of dynamic ground subsidence calculations are presented. After presenting a model for calculating dynamic subsidence, an example is presented in order to illustrate the simplicity of the method. The easy applicability and adaptability of the model and the good agreement between measurements and calculations are pointed out. (MOS).

  10. Effects of the Subsidized Students' Loan on University Enrolment in ...

    African Journals Online (AJOL)

    This paper examines the effect of the subsidized students' loan on university enrolment in Ghana between 1988-2008 using the autoregressive distributed lag (ARDL) framework. It was discovered that the subsidized student loan had positive and significant impact on university enrolment. Per capita gross domestic product ...

  11. Survey of land subsidence–case study: The land subsidence ...

    Indian Academy of Sciences (India)

    The artificial recharge is a technique of aquifer conservation for land subsidence. But in this article, the phenomenon of land subsidence and the resulting cracks and fissures at the study area are formed in recharge ponds. This is a new phenomenon and in this research the geometrical properties of the fissures of recharge ...

  12. Subsidence in the holocene delta of The Netherlands

    NARCIS (Netherlands)

    Vonhögen, L.M.; Doornenbal, P.J.; Lange, G. de; Fokker, P.A.; Gunnink, J.L.


    The low-lying part of The Netherlands is very vulnerable in terms of surface subsidence due to peat oxidation and peat/clay compaction. To gain knowledge about this kind of subsidence and the factors driving it, a study was performed in which as many surface elevation data were collected as possible

  13. Coastal Flooding Hazards due to storm surges and subsidence

    DEFF Research Database (Denmark)

    Sørensen, Carlo; Knudsen, Per; Andersen, Ole B.

    damage potential.Challenges are amplified in some areas due to subsidence from natural and/or anthropogenic causes. Subsidence of even a few mm/y may over time greatly impair the safety against flooding of coastal communities and must be accounted for in order to accomplish the economically most viable...

  14. 30 CFR 819.17 - Auger mining: Subsidence protection. (United States)


    ... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Auger mining: Subsidence protection. 819.17 Section 819.17 Mineral Resources OFFICE OF SURFACE MINING RECLAMATION AND ENFORCEMENT, DEPARTMENT OF THE... MINING § 819.17 Auger mining: Subsidence protection. Auger mining shall be conducted in accordance with...

  15. Land-surface subsidence in the Texas coastal region (United States)

    Ratzlaff, Karl W.


    Land-surface subsidence has been mapped in the Houston-Galveston area and is known to have occurred in other areas within the Texas coastal region. Most of the subsidence has been caused by both the withdrawal of ground water and by the production of oil, gas, and associated ground water.

  16. A comparison of subsidence of Exeter standard and long stems. (United States)

    Davis, Edward T; Heaver, Catriona E; Pynsent, Paul B; Pearson, Andrew M; Treacy, Ronan B C


    The survivorship of the polished, double taper Exeter stem is related to subsidence within the cement mantle. Long Exeter stems have altered geometry which may influence subsidence characteristics. Using digitised x-rays and appropriate computer software we measured the subsidence of 35 standard and 40 long stem Exeter implants. Measurements were taken from initial postoperative radiographs and repeated at intervals up to 5 years. Long stem implants were used in cemented revisions without the use of impaction bone grafting. Subsidence rates of the standard length stems in our study were comparable to that in published literature. Long stems did not replicate this subsidence pattern and had subsided less at 6, 12 and 24 months. However, the 205mm long stem, which has a fully tapered design, did follow the subsidence characteristics of the standard stem. Subsidence of long stem Exeter implants does not mirror that of the standard length stem. Loss of the fully tapered geometry of the longer stem implants may account for this finding. We suggest that whenever possible, the 205mm long stem should be used if the biomechanical principles of the standard Exeter stem are to be utilised.

  17. Subsidizing Private Education at Taxpayer Expense. Policy Brief (United States)

    National Education Association, 2017


    Efforts to subsidize private education take a variety of forms, with the most familiar being the private school voucher provided directly to parents. But there are other less direct ways governments subsidize private schools. One such method is to provide a tax credit to parents to offset their personal education expenses (education tax credit).…

  18. Prevention

    DEFF Research Database (Denmark)

    Halken, S; Høst, A


    , breastfeeding should be encouraged for 4-6 months. In high-risk infants a documented extensively hydrolysed formula is recommended if exclusive breastfeeding is not possible for the first 4 months of life. There is no evidence for preventive dietary intervention neither during pregnancy nor lactation...... populations. These theories remain to be documented in proper, controlled and prospective studies. Breastfeeding and the late introduction of solid foods (>4 months) is associated with a reduced risk of food allergy, atopic dermatitis, and recurrent wheezing and asthma in early childhood. In all infants....... Preventive dietary restrictions after the age of 4-6 months are not scientifically documented....

  19. The effective subsidence capacity concept: How to assure that subsidence in the Wadden Sea remains within defined limits?

    NARCIS (Netherlands)

    Waal, J.A. de; Roest,J.P.A.; Fokker, P.A.; Kroon, I.C.; Breunese, J.N.; Muntendam-Bos, A.G.; Oost, P.A.; Wirdum, G. van


    Subsidence caused by extraction of hydrocarbons and solution salt mining is a sensitive issue in the Netherlands. An extensive legal, technical and organisational framework is in place to ensure a high probability that such subsidence will stay within predefined limits. The key question is: how much

  20. Effects of Wind Speed on Aerosol Spray Penetration in Adult Mosquito Bioassay Cages (United States)


    powers a direct-drive air compressor that pro- duces the air blast that creates the pesticide droplet spectrum at the dual venture style, stainless steel...each replication, the straws were carefully placed in individually labeled plastic bags and stored out of the light to prevent any photodegradation ...M, Coughlin J. 2006. The effect of pesticide residue on caged mosquito bioassays. J Am Mosq Control Assoc 22:469–472. Boobar LR, Dobson SE, Perich MJ

  1. How to deal with subsidence in the Dutch delta? (United States)

    Stouthamer, Esther; Erkens, Gilles


    In many deltas worldwide subsidence still is an underestimated problem, while the threat posed by land subsidence to low-lying urbanizing and urbanized deltas exceeds the threat of sea-level rise induced by climate change. Human-induced subsidence is driven by the extraction of hydrocarbons and groundwater, drainage of phreatic groundwater, and loading by buildings and infrastructure. The consequences of subsidence are increased flood risk and flood water depth, rising groundwater levels relative to the land surface, land loss, damage to buildings and infrastructure, and salinization of ground and surface water.. The Netherlands has a long history of subsidence. Large-scale drainage of the extensive peatlands in the western and northern parts of the Netherlands started approximately 1000 years ago as a result of rapid population growth. Subsidence is still ongoing due to (1) continuous drainage of the former peatland, which is now mainly in use as agricultural land and built-up area, (2) expansion of the built-up area and the infrastructural network, (3) salt mining and the extraction of gas in the northern Netherlands. Mitigating subsidence and its negative impacts requires understanding of the relative contribution of the drivers contributing to total subsidence, accurate predictions of land subsidence under different management scenarios, and its impacts. Such understanding enables the development of effective and sustainable management strategies. In the Netherlands, a lot of effort is put into water management aiming at amongst others the protection against floods and the ensuring agricultural activities, but a specific policy focusing on subsidence is lacking. The development of strategies to cope with subsidence is very challenging, because (1) the exact contribution of different drivers of subsidence to total subsidence is spatially different within the Netherlands, (2) there is no single problem owner, which makes it difficult to recognize this a common

  2. The interaction between land subsidence and urban development in China

    Directory of Open Access Journals (Sweden)

    Y. Yang


    Full Text Available The Yangtze River Delta and North China Plain are experiencing serious land subsidence development and are also the areas that have undergone the fastest urbanization. Rapid urban development inevitably requires more water resources. However, China is a country with small per capita water resources, nonuniform distribution of water resources, and over-exploitation of groundwater – all of which are critical factors contributing to the potential for a land subsidence disaster. In addition, land subsidence has brought about elevation loss, damaged buildings, decreased safety of rail transit projects, lowered land value, and other huge economic losses and potential safety hazards in China. In this paper, Beijing, a typical northern Chinese city deficient in water, is taken as an example to explore (a the problems of urban development, utilization of water resources, and land subsidence development; (b the harm and influence of land subsidence hazards on urban construction; and (c the relationship between urban development and land subsidence. Based on the results, the author has predicted the trend of urban development and land subsidence in Beijing and puts forward her viewpoints and suggestions.

  3. An integrated assessment framework for land subsidence in delta cities

    Directory of Open Access Journals (Sweden)

    T. H. M. Bucx


    Full Text Available In many delta cities land subsidence exceeds absolute sea level rise up to a factor of ten by excessive groundwater extraction related to rapid urbanization and population growth. Without change, parts of Jakarta, Ho Chi Minh City, Bangkok and numerous other delta (and coastal cities will sink below sea level. Increased flooding and also other widespread impacts of land subsidence result already in damage of billions of dollars per year. In order to gain insight in the complex, multi-sectoral aspects of subsidence, to raise awareness and to support decision making on appropriate adaptation strategies and measures, an Integrated Assessment Framework (IAF for subsidence is introduced, illustrated by several (delta case studies. Based on that a list of 10 generic key issues and possible solutions is presented in order to further develop and support a (generic approach how to deal with subsidence in current and future subsidence-prone areas. For exchange of experiences and knowledge development.on subsidence in deltas the Delta Alliance, a knowledge network of deltas worldwide, can be supportive.

  4. Effects of cage density on behavior in young adult mice. (United States)

    Davidson, Lauren P; Chedester, Alan L; Cole, Marlene N


    Optimal housing conditions for mice can be achieved by minimizing environmental variables, such as those that may contribute to anxiety-like behavior. This study evaluated the effects of cage size on juvenile mice through assessment of differences in weaning weight, locomotor skills, and anxiety-like behavior. Eighteen pairs of male and pregnant female Swiss-Webster (Cr:SW) mice were housed in 3 different caging scenarios, providing 429, 505, or 729 cm2 of space. Litters were standardized to 10 pups per litter in each cage. Mice reared in each caging scenario were assessed with the open-field, light-dark exploration, and elevated plus-maze tests. No differences in weaning weight were noted. Mice reared in the 505- and 729-cm2 cages explored a significantly larger area of the open-field arena than did those in the 429-cm2 cages. Those reared in the 505-cm2 cages spent more time in the center of the open field than did those in the 729-cm2 cages, suggesting that anxiety-like behavior may be increased in the animals housed in the larger cages. This study did not establish a consistent link between decreased floor space and increased anxiety-like behavior; neither does there appear to be a consistent effect of available floor area on the development of locomotor skills on mouse pups.

  5. Review of subsidence at Wairakei field, New Zealand

    International Nuclear Information System (INIS)

    Allis, R.G.


    Maximum ground subsidence of 14 m occurred at Wairakei geothermal field between 1950 and 1997 due to development of the field for power generation. The centre of the subsidence bowl is now subsiding at 220 mm/year, after having reached a maximum of 480 mm/year during the mid-1970s. Most of the subsidence is concentrated in a circular area of less than 1 km 2 , centred 500 m from the edge of the production borefield. Smaller rates of subsidence (10-100 mm/year) have occurred over a 30 km 2 area of the field affected by fluid withdrawal for the power plant. Horizontal ground movements ranging to over 200 mm/year, and extensional strain rates of 3 x 10 -4 /year, were measured around the flanks of the subsidence bowl during the mid-1970s. Fissures developed in the areas of greatest extension rate and rigid structures such as pipelines, roads, concrete drains and transmission lines have required maintenance where they traverse the subsidence bowl. A pond has formed in the centre of the bowl, and has influenced groundwater levels in the adjacent borefield. The cause of the subsidence is considered to be compaction of a high porosity, low-permeability lacustrine mudstone at 100-200 m depth. These sediments continue to drain at a slow rate despite pressure stabilisation in the underlying aquifers and the main reservoir during the early 1980s. The small areal extent of the subsidence bowl compared to that of the mudstone is attributed to under-compaction of these lake sediments as they accumulated over the main hot spring outflow zone during the last 100,000 years (Author)

  6. Quantifying Subsidence in the 1999-2000 Arctic Winter Vortex (United States)

    Greenblatt, Jeffery B.; Jost, Hans-juerg; Loewenstein, Max; Podolske, James R.; Bui, T. Paul; Elkins, James W.; Moore, Fred L.; Ray, Eric A.; Sen, Bhaswar; Margitan, James J.; hide


    Quantifying the subsidence of the polar winter stratospheric vortex is essential to the analysis of ozone depletion, as chemical destruction often occurs against a large, altitude-dependent background ozone concentration. Using N2O measurements made during SOLVE on a variety of platforms (ER-2, in-situ balloon and remote balloon), the 1999-2000 Arctic winter subsidence is determined from N2O-potential temperature correlations along several N2O isopleths. The subsidence rates are compared to those determined in other winters, and comparison is also made with results from the SLIMCAT stratospheric chemical transport model.

  7. Multiple sensors applied to monitorland subsidence in Central Taiwan

    Directory of Open Access Journals (Sweden)

    W.-C. Hung


    Full Text Available During 1992–2013, pumping of groundwater caused large-scale aquifer-system compaction and land subsidence in the Choshui River Alluvial Fan (CRAF in Taiwan. The subsidence has already endangered the operation of Taiwan High Speed Rail (THSR. In this paper, we introduce the multiple sensors monitoring system to study the extent of subsidence in CRAF and its mechanism, including GPS (Global Positioning System, PSI (Persistent Scatterer Interferometry, leveling and multi-layer compaction monitoring well. These sensors complement each other in spatial and temporal resolutions.

  8. [Results to 4-year follow-up of the treatment of the cervical stenosis by corpectomy, titanium mesh cage and anterior plate fixation]. (United States)

    Reyes Sánchez, Alejandro Antonio; Gameros Castañeda, Luis Alberto; Obil Chavarría, Claudia; Alpizar Aguirre, Armando; Zárate Kalfópulos, Barón; Rosales-Olivares, Luis Miguel

    Cervical spondylotic myelopathy is caused by cervical stenosis. Several techniques have been described for the treatment of multilevel disease, such as the anterior corpectomy with titanium mesh cage and anterior cervical plate placement, which has the advantage of performing a wider decompression and using the same bone as graft. However, it has caused controversy since the collapse of the mesh cage continues being a major limitation of this procedure. A prospective 4-year follow-up study was conducted in 7 patients diagnosed with cervical stenosis, who were treated surgically by one level corpectomy with titanium mesh cage and anterior cervical plate placement, evaluating them by radiographs and clinical scales. 7 patients, 5 women and 2 males were studied. The most common level was C5 corpectomy (n=4). The Neck Disability Index (NDI) preoperative average was 30.01±24.32 and 4-year postoperative 16.90±32.05, with p=0.801. The preoperative and 4-year postoperative Nürick was 3.28± 48 and 3.14±1.21 respectively, with p=0.766. Preoperative lordosis was 14.42±8.03 and 4-year postoperative 17±11.67 degrees, with p=0.660. The immediate postoperative and 4-year postoperative subsidence was 2.69±2.8 and 6.11±1.61 millimeters respectively, with p=0.0001. Despite the small sample, the subsidence of the mesh cage is common in this procedure. No statistically significant changes were observed in the lordosis or Nürick scale and NDI. Copyright © 2016 Academia Mexicana de Cirugía A.C. Publicado por Masson Doyma México S.A. All rights reserved.

  9. Preinjector for Linac 1, Faraday cage

    CERN Document Server


    The 50 MeV Linac 1 started up in 1958 as injector to the 26 GeV PS, with a 520 kV Cockcroft-Walton generator as its preinjector, housed in a vast Faraday cage, visible here. When the Cockcroft-Walton broke down in 1973, it was replaced by a much smaller SAMES generator, of the kind used for electrostatic separators. From 1980 on, Linac 2 took over as injector for the 800 MeV Booster, and Linac 1 continued as injector for LEAR. In 1984, the electrostatic preinjector (i.e. the Faraday cage with its contents, SAMES generator and all) was replaced by a 520 keV RFQ. At the lower left corner we see the HV connectors to the SAMES generator, at the right edge part of the opened electronics-platform. Jean-Luc Vallet sees to it that all parts are properly grounded. See also 7403073X, 7403074X, 7403081X, 7403083X.

  10. Bulletproof Love : Luke Cage (2016 and Religion

    Directory of Open Access Journals (Sweden)

    Derry, Ken


    Full Text Available There are many ways to think about religion and popular culture. One method is to ask where and when we see what might be commonly understood as “religious tradition(s” explicitly on display. Another is to think about superhero narratives themselves as “religious”, using this term as a conceptual tool for categorizing and thereby better understanding particular dimensions of human experience. This article takes a variety of approaches to understanding religion in relation to the recent television series LUKE CAGE (Netflix, US 2016. These approaches take their hermeneutical cues from a range of disciplines, including studies of the Bible; Hip Hop; gender; Black Theology; African American religion; and philosophy. The results of this analysis highlight the polysemic nature of popular culture in general, and of superhero stories in particular. Like religious traditions themselves, the show is complex and contradictory: it is both progressive and reactionary; emphasizes community and valorizes an individual; critiques and endorses Christianity; subverts and promotes violence. Depending on the questions asked, LUKE CAGE (2016 provides a range of very different answers.

  11. Polar self-assembly: steric effects leading to polar mixed-ligand coordination cages. (United States)

    Zhang, Jianyong; Miller, Philip W; Nieuwenhuyzen, Mark; James, Stuart L


    We present a highly unusual example of self-assembly, specifically a polar, mixed-ligand cage which forms in preference to symmetrical homo-ligand products, and which suggests that steric effects can be exploited to obtain novel non-uniform polyhedral cages. In particular, reaction between the bulky tripodal triphosphine 2,4,6-tris(diphenylphosphino)triazine, L1, the non-bulky tripodal trinitrile 2,4,6-tris(cyanomethyl)trimethylbenzene, L2 and silver hexafluoroantimonate, AgSbF6, in a 3:1:4 ratio gives the mixed-ligand aggregate [Ag4(L1)3(L2)(SbF6)]3+, 1-SbF6, instantly as the only product in quantitative yield. The X-ray crystal structure of complex 1-SbF6 is consistent with the suspected solution-state structure. The cage derives from trigonal-pyramidal geometry, the basal vertices of which are defined by three bulky triphosphines, L1, and the apical vertex by the non-bulky trinitrile, L2. There is apical elongation amounting to 19% in comparison to the ideal uniform tetrahedron. The cage also encapsulates an SbF6 anion. 19F NMR spectra in solution for the analogous PF6 complex [Ag4(L1)3(L2)(PF6)]3+, 1-PF6, confirm that one anion is also encapsulated in solution. The synthesis of the analogous CF3SO3(-) complex, [Ag4(L1)3(L2)(OTf)]3+, 1-OTf, in solution is also described, although 1-PF6 and 1-OTf could not be isolated due to slow decomposition in solution. The selective formation of these mixed-ligand cages is discussed in terms of ligand-ligand and ligand-included anion steric repulsions, which we propose prevent the formation of the competing hypothetical homo-ligand tetrahedral structure [Ag4(L1)4(SbF6)]3+, and thus favour the mixed ligand cage. "Cage cone angles" for L1 and L2 are estimated at 115 degrees and 101 degrees, respectively. Variable-temperature 31P NMR spectroscopy shows that complex 1-SbF6 and the related previously reported partial tetrahedral complex [Ag4(L1)3(anion)]3+ undergo dynamic twisting processes in solution between enantiomeric C3

  12. Computed tomography measurement of rib cage morphometry in emphysema.

    Directory of Open Access Journals (Sweden)

    Nicola Sverzellati

    Full Text Available BACKGROUND: Factors determining the shape of the human rib cage are not completely understood. We aimed to quantify the contribution of anthropometric and COPD-related changes to rib cage variability in adult cigarette smokers. METHODS: Rib cage diameters and areas (calculated from the inner surface of the rib cage in 816 smokers with or without COPD, were evaluated at three anatomical levels using computed tomography (CT. CTs were analyzed with software, which allows quantification of total emphysema (emphysema%. The relationship between rib cage measurements and anthropometric factors, lung function indices, and %emphysema were tested using linear regression models. RESULTS: A model that included gender, age, BMI, emphysema%, forced expiratory volume in one second (FEV1%, and forced vital capacity (FVC% fit best with the rib cage measurements (R(2 = 64% for the rib cage area variation at the lower anatomical level. Gender had the biggest impact on rib cage diameter and area (105.3 cm(2; 95% CI: 111.7 to 98.8 for male lower area. Emphysema% was responsible for an increase in size of upper and middle CT areas (up to 5.4 cm(2; 95% CI: 3.0 to 7.8 for an emphysema increase of 5%. Lower rib cage areas decreased as FVC% decreased (5.1 cm(2; 95% CI: 2.5 to 7.6 for 10 percentage points of FVC variation. CONCLUSIONS: This study demonstrates that simple CT measurements can predict rib cage morphometric variability and also highlight relationships between rib cage morphometry and emphysema.

  13. The SNAP trial: a double blind multi-center randomized controlled trial of a silicon nitride versus a PEEK cage in transforaminal lumbar interbody fusion in patients with symptomatic degenerative lumbar disc disorders: study protocol (United States)


    Background Polyetheretherketone (PEEK) cages have been widely used in the treatment of lumbar degenerative disc disorders, and show good clinical results. Still, complications such as subsidence and migration of the cage are frequently seen. A lack of osteointegration and fibrous tissues surrounding PEEK cages are held responsible. Ceramic implants made of silicon nitride show better biocompatible and osteoconductive qualities, and therefore are expected to lower complication rates and allow for better fusion. Purpose of this study is to show that fusion with the silicon nitride cage produces non-inferior results in outcome of the Roland Morris Disability Questionnaire at all follow-up time points as compared to the same procedure with PEEK cages. Methods/Design This study is designed as a double blind multi-center randomized controlled trial with repeated measures analysis. 100 patients (18–75 years) presenting with symptomatic lumbar degenerative disorders unresponsive to at least 6 months of conservative treatment are included. Patients will be randomly assigned to a PEEK cage or a silicon nitride cage, and will undergo a transforaminal lumbar interbody fusion with pedicle screw fixation. Primary outcome measure is the functional improvement measured by the Roland Morris Disability Questionnaire. Secondary outcome parameters are the VAS leg, VAS back, SF-36, Likert scale, neurological outcome and radiographic assessment of fusion. After 1 year the fusion rate will be measured by radiograms and CT. Follow-up will be continued for 2 years. Patients and clinical observers who will perform the follow-up visits will be blinded for type of cage used during follow-up. Analyses of radiograms and CT will be performed independently by two experienced radiologists. Discussion In this study a PEEK cage will be compared with a silicon nitride cage in the treatment of symptomatic degenerative lumbar disc disorders. To our knowledge, this is the first randomized controlled

  14. Analysis of geodetic surveying on the margin of subsidence depression

    Czech Academy of Sciences Publication Activity Database

    Doležalová, Hana; Müller, Karel; Bláha, P.

    -, č. 273 (2006), s. 103-112 ISSN 0372-9508 Institutional research plan: CEZ:AV0Z30860518 Keywords : subsidence depression * levelling * height changes Subject RIV: DE - Earth Magnetism, Geodesy, Geography

  15. Use of Cemented Super-Fine Unclassified Tailings Backfill for Control of Subsidence

    Directory of Open Access Journals (Sweden)

    Lei Yang


    Full Text Available Known for its advantages in preventing geological and environmental hazards, cemented paste backfill (CPB has become a topic of interest for scientists and mining engineers in recent decades. This paper presents the results of a study on the use of cemented super-fine tailings backfill (CSUTB in an underground mine for control of surface subsidence. An analytical solution is developed based on the available model to calculate the required strength of backfill when in contact with non-cemented tailings (NCT. The effect of solid contents on the rheological properties of CSUTB is investigated. A reasonable mix proportion (RMP of CSUTB is determined for Zhongguan Iron Mine (ZGIM based on laboratory experiments. The validity of RMP in surface subsidence control is verified by a 3D numerical model. The obtained results show that CSUTB requires higher strength when in contact with NCT than when in contact with orebody. Rheological characteristics, e.g., slump, fluidity, and bleeding rate of fresh CSUTB, decrease with higher solids content, of which values with a certain solids content can be determined by quadratic polynomial regression equations. RMP with a cement to tailings (c/t ratio of 1:10 and a solids content of 70% is recommended for ZGIM, as it shows favorable mechanical and rheological abilities. The deformation parameters (curvature, inclination, and horizontal deformation rate obtained from numerical modeling are acceptable and lower than critical values, meaning CSUTB can feasibly be used with RMP in subsidence control.

  16. Effects of vertebroplasty on endplate subsidence in elderly female spines. (United States)

    Nagaraja, Srinidhi; Awada, Hassan K; Dreher, Maureen L; Bouck, John T; Gupta, Shikha


    The aim in this study was to quantify the effects of vertebroplasty on endplate subsidence in treated and adjacent vertebrae and their relationship to endplate thickness and underlying trabecular bone in elderly female spines. Vertebral compression fractures were created in female cadaveric (age range 51-88 years) thoracolumbar spine segments. Specimens were placed into either the control or vertebroplasty group (n = 9/group) such that bone mineral density, trabecular microarchitecture, and age were statistically similar between groups. For the vertebroplasty group, polymethylmethacrylate bone cement was injected into the fractured vertebral body under fluoroscopy. Cyclic compression (685-1370 N sinusoid) was performed on all spine segments for 115,000 cycles. Micro-CT scans were obtained before and after cyclic loading to quantify endplate subsidence. Maximum subsidence was compared between groups in the caudal endplate of the superior adjacent vertebra (SVcau); cranial (TVcra) and caudal (TVcau) endplates of the treated vertebra; and the cranial endplate of the inferior adjacent vertebra (IVcra). In addition, micro-CT images were used to quantify average endplate thickness and trabecular bone volume fraction. These parameters were then correlated with maximum endplate subsidence for each endplate. The maximum subsidence in SVcau endplate for the vertebroplasty group (0.34 ± 0.58 mm) was significantly (p subsidence in the TVcra, TVcau, and IVcra endplates were greater in the vertebroplasty group, but these differences were not significant (p > 0.16). Increased subsidence in the vertebroplasty group manifested locally in the anterior region of the SVcau endplate and in the posterior region of the TVcra and TVcau endplates (p subsidence was observed in thinner endplates with lower trabecular bone volume fraction for both vertebroplasty and control groups (R(2) correlation up to 62%). In the SVcau endplate specifically, these 2 covariates aided in understanding

  17. Research on critical groundwater level under the threshold value of land subsidence in the typical region of Beijing

    Directory of Open Access Journals (Sweden)

    Y. Jiang


    Full Text Available Groundwater in Beijing has been excessively exploited in a long time, causing the groundwater level continued to declining and land subsidence areas expanding, which restrained the economic and social sustainable development. Long years of study show good time-space corresponding relationship between groundwater level and land subsidence. To providing scientific basis for the following land subsidence prevention and treatment, quantitative research between groundwater level and settlement is necessary. Multi-linear regression models are set up by long series factual monitoring data about layered water table and settlement in the Tianzhu monitoring station. The results show that: layered settlement is closely related to water table, water level variation and amplitude, especially the water table. Finally, according to the threshold value in the land subsidence prevention and control plan of China (45, 30, 25 mm, the minimum allowable layered water level in this region while settlement achieving the threshold value is calculated between −18.448 and −10.082 m. The results provide a reasonable and operable control target of groundwater level for rational adjustment of groundwater exploited horizon in the future.

  18. Working to Reduce Poverty: A National Subsidized Employment Proposal


    Indivar Dutta-Gupta; Kali Grant; Julie Kerksick; Dan Bloom; Ajay Chaudry


    Subsidized employment programs that increase labor supply and demand are a proven, underutilized strategy for reducing poverty in the short and long term. These programs use public and private funds to provide workers wage-paying jobs, training, and wraparound services to foster greater labor force attachment while offsetting employers’ cost for wages, on-the-job training, and overhead. This article proposes two new separate but harmonized federal funding streams for subsidized employment tha...

  19. Areas of ground subsidence due to geofluid withdrawal

    Energy Technology Data Exchange (ETDEWEB)

    Grimsrud, G.P.; Turner, B.L.; Frame, P.A.


    Detailed information is provided on four geothermal areas with histories of subsidence. These were selected on the basis of: physical relevance of subsidence areas to high priority US geothermal sites in terms of withdrawn geofluid type, reservoir depth, reservoir geology and rock characteristics, and overburden characteristics; and data completeness, quality, and availability. The four areas are: Chocolate Bayou, Raft River Valley, Wairakei, and the Geysers. (MHR)

  20. Detecting, mapping and monitoring of land subsidence in Jharia ...

    Indian Academy of Sciences (India)

    monitoring of the subsiding areas vulnerable to future collapse. This will .... areas that are vulnerable to future roof collapse. ..... F22. F21. F20. F23. F24. F25. F16. Figure 5. Land subsidence areas in Jharia Coalfield as obtained separately from C- and L-band DInSAR during 2007–2008 by union of the fringes ('a' and 'b' ...

  1. Adaptation and mitigation of land subsidence in Semarang (United States)

    Andreas, Heri; Abidin, Hasanuddin Z.; Gumilar, Irwan; Sidiq, Teguh Purnama; Yuwono, Bambang


    Land subsidence is not a new phenomenon for Semarang. Some report said the subsidence in Semarang probably is occurring for more than 100 years. Based on the leveling surveys conducted by the Centre of Environmental Geology from 1999 to 2003 it was found that relatively large subsidence was detected around Semarang Harbor, Pondok Hasanuddin, Bandar Harjo and around Semarang Tawang Railway station, with the rates ranging from 1 to 17 cm/year. Results derived from GPS show that land subsidence in Semarang has spatial and temporal variations. In general, subsidence rates in Semarang have an average rate of about 6 to 7 cm/year, with maximum rates that can go up to 14-19 cm/year at certain locations. The impact of land subsidence in Semarang can be seen in several forms, such as the wider expansion of (coastal) flooding areas "rob", cracking of buildings and infrastructure, and increased inland sea water intrusion. It also badly influences the quality and amenity of the living environment and life (e.g. health and sanitation condition) in the affected areas. In the case of Semarang, adaptation and mitigation are considered very important. We have been done some investigations to this area by field observations (mapping the flooded area, mapping the infrastructure problems, interviewing people and seeing the adaptations, conduct GPS measurement to see deformation, etc.), gather information from Government, from digital media, etc., and we noticed people increased their house, and the local goverment elevated the road and the bridge, etc. regulary over less decade periode as part of adaptation. We also noticed the Central Goverment built the dyke and pumping station. Our conclusions said that the adaptation only made temporaly since significant land subsidence keep coming and worsening by the sea level which is keep rising. Another conclusion, so far we have seen lack of mitigation program, monitoring or even inevective mitigation in Semarang related to this subsidence

  2. First Results from the ALICE TPC Field Cage Prototype

    CERN Document Server

    Bächler, J; CERN. Geneva; Garabatos, C; Goret, B; Hoch, M; Klempt, W; Lagrue, X; Lenoir, P; Lesenechal, Y; Mast, M; Meyer, T C; Raynaud, J; Renfordt, R E; Schäfer, E; Sharma, A; Vranic, D


    Abstract This note summarizes the first phase in a series of tests with the ALICE TPC field cage prototype. We will demonstrate that the chosen design of the field cage and the layout of the potential degrader are able to satisfy our specific demands on static HV stability of the ALICE TPC at the LHC Heavy-Ion- Collider.

  3. Polymers containing borane or carborane cage compounds and related applications (United States)

    Bowen, III, Daniel E.; Eastwood, Eric A [Raymore, MO


    Polymers comprising residues of borane and/or carborane cage compound monomers having at least one polyalkoxy silyl substituent. Such polymers can further comprise one or more reactive matrices and/or co-monomers covalently bound with the cage compound monomer residues. Methods of making and applications for using such polymers are also disclosed.

  4. 48 CFR 204.7202-1 - CAGE codes. (United States)


    ..., DEPARTMENT OF DEFENSE GENERAL ADMINISTRATIVE MATTERS Contractor Identification 204.7202-1 CAGE codes. (a... CD ROM that contains the H-4/H-8 CAGE master file issued by DLIS (Their address is: Customer Service... assignments to DLIS Customer Service: toll-free (888) 227-2423 or (888) 352-9333; DSN 932-4725; or commercial...

  5. Comparative architecture of octahedral protein cages. I. Indexed enclosing forms (United States)

    Janner, A.


    The architecture of four protein cages (bacterio ferritin, human mitochondrial ferritin, sulfur oxygenase reductase and small heat-shock protein) are compared top-to-bottom, starting from polyhedra with vertices at cubic lattice points enclosing the cage down to indexed polyhedral forms of single monomers.

  6. Influence of Clarias gariepinus (Teugels) cage cultures on water ...

    African Journals Online (AJOL)

    Water quality, periphyton and phytoplankton growing as a function Clarias gariepinus (Burchell, 1822) cage cultures have rarely been investigated. Physical and chemical factors associated with cage culture of Clarias gariepinus in relation to phytoplankton and periphyton were examined fortnightly from May to June 2009 ...

  7. Abnormal Behavior in Relation to Cage Size in Rhesus Monkeys (United States)

    Paulk, H. H.; And Others


    Examines the effects of cage size on stereotyped and normal locomotion and on other abnormal behaviors in singly caged animals, whether observed abnormal behaviors tend to co-occur, and if the development of an abnormal behavior repertoire leads to reduction in the number of normal behavior categories. (Author/RK)

  8. Teaching in the Institutional Cage: Metaphor and Collateral Oppression (United States)

    Noël Smith, Becky L.


    This analysis is a philosophical exploration of Marilyn Frye's metaphor of the cage and Patricia Hill Collins' theory of intersecting oppressions. It argues that social structures and forms of oppressive knowledge make up the individual wires on each person's cage and that these work to confine individuals, particularly those in the…

  9. Detecting and monitoring UCG subsidence with InSAR

    Energy Technology Data Exchange (ETDEWEB)

    Mellors, R J; Foxall, W; Yang, X


    The use of interferometric synthetic aperture radar (InSAR) to measure surface subsidence caused by Underground Coal Gasification (UCG) is tested. InSAR is a remote sensing technique that uses Synthetic Aperture Radar images to make spatial images of surface deformation and may be deployed from satellite or an airplane. With current commercial satellite data, the technique works best in areas with little vegetation or farming activity. UCG subsidence is generally caused by roof collapse, which adversely affects UCG operations due to gas loss and is therefore important to monitor. Previous studies have demonstrated the usefulness of InSAR in measuring surface subsidence related to coal mining and surface deformation caused by a coal mining roof collapse in Crandall Canyon, Utah is imaged as a proof-of-concept. InSAR data is collected and processed over three known UCG operations including two pilot plants (Majuba, South Africa and Wulanchabu, China) and an operational plant (Angren, Uzbekistan). A clear f eature showing approximately 7 cm of subsidence is observed in the UCG field in Angren. Subsidence is not observed in the other two areas, which produce from deeper coal seams and processed a smaller volume. The results show that in some cases, InSAR is a useful tool to image UCG related subsidence. Data from newer satellites and improved algorithms will improve effectiveness.

  10. Generation of Multicomponent Molecular Cages using Simultaneous Dynamic Covalent Reactions. (United States)

    Drożdż, Wojciech; Bouillon, Camille; Kotras, Clément; Richeter, Sébastien; Barboiu, Mihail; Clément, Sébastien; Stefankiewicz, Artur R; Ulrich, Sébastien


    Cage compounds are very attractive structures for a wide range of applications and there is ongoing interest in finding effective ways to access such kinds of complex structures, particularly those possessing dynamic adaptive features. Here we report the accessible synthesis of new type of organic cage architectures, possessing two different dynamic bonds within one structure: hydrazones and disulfides. Implementation of three distinct functional groups (thiols, aldehydes and hydrazides) in the structure of two simple building blocks resulted in their spontaneous and selective self-assembly into aromatic cage-type architectures. These organic cages contain up to ten components linked together by twelve reversible covalent bonds. The advantage provided by the presented approach is that these cage structures can adaptively self-sort from a complex virtual mixture of polymers or macrocycles and that dynamic covalent chemistry enables their deliberate disassembly through controlled component exchange. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. Photoactivatable Caged Prodrugs of VEGFR-2 Kinase Inhibitors

    Directory of Open Access Journals (Sweden)

    Boris Pinchuk


    Full Text Available In this study, we report on the design, synthesis, photokinetic properties and in vitro evaluation of photoactivatable caged prodrugs for the receptor tyrosine kinase VEGFR-2. Highly potent VEGFR-2 inhibitors 1 and 3 were caged by introduction of a photoremovable protecting group (PPG to yield the caged prodrugs 4 and 5. As expected, enzymatic and cellular proliferation assays showed dramatically diminished efficacy of caged prodrugs in vitro. Upon ultraviolet (UV irradiation of the prodrugs original inhibitory activity was completely restored and even distinctly reinforced, as was the case for the prodrug 4. The presented results are a further evidence for caging technique being an interesting approach in the protein kinase field. It could enable spatial and temporal control for the inhibition of VEGFR-2. The described photoactivatable prodrugs might be highly useful as biological probes for studying the VEGFR-2 signal transduction.

  12. A Simple, Inexpensive Metabolism Cage for Small Mammals ** (United States)

    Pfeiffer, C. J.; Gass, G. H.


    By utilizing ordinary laboratory equipment and a spherical feces-urine separator, a simple, inexpensive metabolism cage for small mammals can be constructed. A hardware cloth animal cage over a cylindrical battery jar containing a spherical feces-urine separator affords the following advantages not commonly found in commercial metabolism cages: 1) complete separation of feces and urine through minimal contact, 2) minimal evaporation of urine due to proximity of storage vessel and lack of exogenous air currents, and 3) extremely low cost of less than five dollars. The metabolism cage is designed to allow measurement of fluid intake, and to separate and collect feces and urine for numerous qualitative and quantitative determinations. In addition, the metabolism cage permits observation of the animal, feces, and urine at all times, is readily cleaned or sterilized, and is easily fashioned from common laboratory equipment. ImagesFIG. 1. PMID:17649428

  13. Entropic cages for trapping DNA near a nanopore (United States)

    Liu, Xu; Skanata, Mirna Mihovilovic; Stein, Derek


    Nanopores can probe the structure of biopolymers in solution; however, diffusion makes it difficult to study the same molecule for extended periods. Here we report devices that entropically trap single DNA molecules in a 6.2-femtolitre cage near a solid-state nanopore. We electrophoretically inject DNA molecules into the cage through the nanopore, pause for preset times and then drive the DNA back out through the nanopore. The saturating recapture time and high recapture probability after long pauses, their agreement with a convection-diffusion model and the observation of trapped DNA under fluorescence microscopy all confirm that the cage stably traps DNA. Meanwhile, the cages have 200 nm openings that make them permeable to small molecules, like the restriction endonuclease we use to sequence-specifically cut trapped DNA into fragments whose number and sizes are analysed upon exiting through the nanopore. Entropic cages thus serve as reactors for chemically modifying single DNA molecules.

  14. Potential of Holocene deltaic sequences for subsidence due to peat compaction

    NARCIS (Netherlands)

    Stouthamer, E.; van Asselen, S.


    Land subsidence is a major threat for the livability of deltas worldwide. Mitigation of the negative impacts of subsidence, like increasing flooding risk, requires an assessment of the potential of the deltas’ subsurfaces for subsidence. This enables the prediction of current and future subsidence

  15. A new soil mechanics approach to quantify and predict land subsidence by peat compression

    NARCIS (Netherlands)

    Koster, K.; Erkens, G.; Zwanenburg, C.


    Land subsidence threatens many coastal areas. Quantifying current and predicting future subsidence are essential to sustain the viability of these areas with respect to rising sea levels. Despite its scale and severity, methods to quantify subsidence are scarce. In peat-rich subsidence hot spots,

  16. Cathodic Cage Plasma Nitriding: An Innovative Technique

    Directory of Open Access Journals (Sweden)

    R. R. M. de Sousa


    Full Text Available Cylindrical samples of AISI 1020, AISI 316, and AISI 420 steels, with different heights, were simultaneously treated by a new technique of ionic nitriding, entitled cathodic cage plasma nitriding (CCPN, in order to evaluate the efficiency of this technique to produce nitrided layers with better properties compared with those obtained using conventional ionic nitriding technique. This method is able to eliminate the edge effect in the samples, promoting a better uniformity of temperature, and consequently, a smaller variation of the thickness/height relation can be obtained. The compound layers were characterized by X-ray diffraction, optical microscopy, and microhardness test profile. The results were compared with the properties of samples obtained with the conventional nitriding, for the three steel types. It was verified that samples treated by CCPN process presented, at the same temperature, a better uniformity in the thickness and absence of the edge effect.

  17. Alejandra Pizarnik: the bird that was cage

    Directory of Open Access Journals (Sweden)

    Isabel Abellán Chuecos


    Full Text Available It is well known the relation –sometimes deceiving– that has been established by poets between literature and life. In the case of cursed poets, literature and life usually identify with each other, and talking about Alejandra Pizarnik, we could even establish this relation between literature and death, thus nothing is more daily than life. With this essay we try to identify the threads that converge and interweave the verses and the life, to be wandering and at the same time a prisoner, to have wings but stay in a cage, the confinement in a wandering reality. We will analyse the poetic individual and, at the same time, the construction of a character in life.

  18. Transcription regulatory networks analysis using CAGE

    KAUST Repository

    Tegnér, Jesper N.


    Mapping out cellular networks in general and transcriptional networks in particular has proved to be a bottle-neck hampering our understanding of biological processes. Integrative approaches fusing computational and experimental technologies for decoding transcriptional networks at a high level of resolution is therefore of uttermost importance. Yet, this is challenging since the control of gene expression in eukaryotes is a complex multi-level process influenced by several epigenetic factors and the fine interplay between regulatory proteins and the promoter structure governing the combinatorial regulation of gene expression. In this chapter we review how the CAGE data can be integrated with other measurements such as expression, physical interactions and computational prediction of regulatory motifs, which together can provide a genome-wide picture of eukaryotic transcriptional regulatory networks at a new level of resolution. © 2010 by Pan Stanford Publishing Pte. Ltd. All rights reserved.

  19. Traces of warping subsided tectonic blocks on Miranda, Enceladus, Titan (United States)

    Kochemasov, G.


    Icy satellites of the outer Solar system have very large range of sizes - from kilometers to thousands of kilometers. Bodies less than 400-500 km across have normally irregular shapes , often presenting simple Plato's polyhedrons woven by standing inertiagravity waves (see an accompanying abstract of Kochemasov). Larger bodies with enhanced gravity normally are rounded off and have globular shapes but far from ideal spheres. This is due to warping action of inertia-gravity waves of various wavelengths origin of which is related to body movements in elliptical keplerian orbits with periodically changing accelerations (alternating accelerations cause periodically changing forces acting upon a body what means oscillations of its spheres in form of standing warping waves). The fundamental wave 1 and its first overtone wave 2 produce ubiquitous tectonic dichotomy - two segmental structure and tectonic sectoring superimposed on this dichotomy. Two kinds of tectonic blocks (segments and sectors) are formed: uplifted (+) and subsided (-). Uplifting means increasing planetary radius of blocks, subsiding - decreasing radius (as a sequence subsiding blocks diminishing their surfaces must be warped, folded, wrinkled; uplifting blocks increasing their surfaces tend to be deeply cracked, fallen apart). To level changing angular momenta of blocks subsided areas are filled with denser material than uplifted ones (one of the best examples is Earth with its oceanic basins filled with dense basalts and uplifted continents built of less dense on average andesitic material). Icy satellites follow the same rule. Their warped surfaces show differing chemistries or structures of constructive materials. Uplifted blocks are normally built with light (by color and density) water ice. Subsided blocks - depressions, "seas', "lakes", coronas - by somewhat denser material differing in color from water ice (very sharply - Iapetus, moderately - Europa, slightly - many saturnian satellites). A very

  20. Subsidence and carbon loss in drained tropical peatlands

    Directory of Open Access Journals (Sweden)

    A. Hooijer


    Full Text Available Conversion of tropical peatlands to agriculture leads to a release of carbon from previously stable, long-term storage, resulting in land subsidence that can be a surrogate measure of CO2 emissions to the atmosphere. We present an analysis of recent large-scale subsidence monitoring studies in Acacia and oil palm plantations on peatland in SE Asia, and compare the findings with previous studies. Subsidence in the first 5 yr after drainage was found to be 142 cm, of which 75 cm occurred in the first year. After 5 yr, the subsidence rate in both plantation types, at average water table depths of 0.7 m, remained constant at around 5 cm yr−1. The results confirm that primary consolidation contributed substantially to total subsidence only in the first year after drainage, that secondary consolidation was negligible, and that the amount of compaction was also much reduced within 5 yr. Over 5 yr after drainage, 75 % of cumulative subsidence was caused by peat oxidation, and after 18 yr this was 92 %. The average rate of carbon loss over the first 5 yr was 178 t CO2eq ha−1 yr−1, which reduced to 73 t CO2eq ha−1 yr−1 over subsequent years, potentially resulting in an average loss of 100 t CO2eq ha−1 yr−1 over 25 yr. Part of the observed range in subsidence and carbon loss values is explained by differences in water table depth, but vegetation cover and other factors such as addition of fertilizers also influence peat oxidation. A relationship with groundwater table depth shows that subsidence and carbon loss are still considerable even at the highest water levels theoretically possible in plantations. This implies that improved plantation water management will reduce these impacts by 20 % at most, relative to current conditions, and that high rates of carbon loss and land subsidence are

  1. Emplacement and Subsidence of Indian Ocean Plateaus and Submarine Ridges (United States)

    Coffin, Millard F.

    Ocean Drilling Program, Deep Sea Drilling Project, and industrial borehole results from Indian Ocean plateaus and submarine ridges help to constrain their subsidence histories. I use a simple Airy isostatic model to calculate basement depths at ODP sites in the absence of sediment, and then backtrack these sites using previously determined age-depth relationships for oceanic lithosphere to determine the original depth or elevation of the sites. Resulting subsidence curves for each site were then checked by examining sedimentologic and biostratigraphic evidence for when each site subsided below shelf depths. The analysis suggests that thermal subsidence has been the dominant tectonic process affecting Indian Ocean plateaus and submarine ridges following emplacement. I conclude that large portions of these features were emplaced and began subsiding well above sea level, similar to large igneous provinces (LIPs) worldwide today. This resulted in significant subaerial erosion and redeposition of volcanic material mixed with biogenic sediment, and a gradual development of facies from terrestrial through terrigenous to shallow water and pelagic, resulting in a sedimentary record with both continental and oceanic characteristics.

  2. Origins of oblique-slip faulting during caldera subsidence (United States)

    Holohan, Eoghan P.; Walter, Thomas R.; Schöpfer, Martin P. J.; Walsh, John J.; van Wyk de Vries, Benjamin; Troll, Valentin R.


    Although conventionally described as purely dip-slip, faults at caldera volcanoes may have a strike-slip displacement component. Examples occur in the calderas of Olympus Mons (Mars), Miyakejima (Japan), and Dolomieu (La Reunion). To investigate this phenomenon, we use numerical and analog simulations of caldera subsidence caused by magma reservoir deflation. The numerical models constrain mechanical causes of oblique-slip faulting from the three-dimensional stress field in the initial elastic phase of subsidence. The analog experiments directly characterize the development of oblique-slip faulting, especially in the later, non-elastic phases of subsidence. The combined results of both approaches can account for the orientation, mode, and location of oblique-slip faulting at natural calderas. Kinematically, oblique-slip faulting originates to resolve the following: (1) horizontal components of displacement that are directed radially toward the caldera center and (2) horizontal translation arising from off-centered or "asymmetric" subsidence. We informally call these two origins the "camera iris" and "sliding trapdoor" effects, respectively. Our findings emphasize the fundamentally three-dimensional nature of deformation during caldera subsidence. They hence provide an improved basis for analyzing structural, geodetic, and geophysical data from calderas, as well as analogous systems, such as mines and producing hydrocarbon reservoirs.

  3. What’s the Score? Walkable Environments and Subsidized Households

    Directory of Open Access Journals (Sweden)

    Young-Jae Kim


    Full Text Available Neighborhood walkability can influence individual health, social interactions, and environmental quality, but the relationships between subsidized households and their walkable environment have not been sufficiently examined in previous empirical studies. Focusing on two types of subsidized housing developments (Low-Income Housing Tax Credit (LIHTC and Public Housing (PH in Austin, Texas, this study evaluates the neighborhood walkability of place-based subsidized households, utilizing objectively measured Walk Score and walking-related built environment data. We also used U.S. Census block group data to account for the socio-demographic covariates. Based on various data, we employed bivariate and multivariate analyses to specify the relationships between subsidized households and their neighborhood walkable environment. The results of our bivariate analyses show that LIHTC households tend to be located in car-dependent neighborhoods and have more undesirable walking-related built environment conditions compared with non-LIHTC neighborhoods. Our regression results also represent that LIHTC households are more likely to be exposed to neighborhoods with low Walk Score, less sidewalk coverage, and more highways and major roads, while there are no significant associations for PH households. These findings imply that more attention and effort toward reducing the inequitable distributions of walkable neighborhood features supporting rather than hindering healthy lifestyles must be provided to subsidized households.

  4. Underground coal mine subsidence impacts on surface water

    International Nuclear Information System (INIS)

    Stump, D.E. Jr.


    This paper reports that subsidence from underground coal mining alters surface water discharge and availability. The magnitude and areal extent of these impacts are dependent on many factors, including the amount of subsidence, topography, geology, climate, surface water - ground water interactions, and fractures in the overburden. There alterations may have positive and/or negative impacts. One of the most significant surface water impacts occurred in July 1957 near West Pittston, Pennsylvania. Subsidence in the Knox Mine under the Coxton Yards of the Lehigh Valley Railroad allowed part of the discharge in the Susquehanna River to flow into the mine and create a crater 200 feet in diameter and 300 feet deep. Fourteen railroad gondola cars fell into the hole which was eventually filled with rock, sand, and gravel. Other surface water impacts from subsidence may include the loss of water to the ground water system, the gaining of water from the ground water system, the creation of flooded subsidence troughs, the increasing of impoundment storage capacity, the relocation of water sources (springs), and the alteration of surface drainage patterns

  5. In vivo antimicrobial activity of marbofloxacin against Pasteurella multocida in a tissue cage model in calves

    Directory of Open Access Journals (Sweden)

    Changfu eCao


    Full Text Available Marbofloxacin is a fluoroquinolone specially developed for use in veterinary medicine with broad-spectrum antibacterial activity. The objective of our study was to re-evaluate in vivo antimicrobial activity of marbofloxacin against Pasteurella multocida using subcutaneously implanted tissue cages in calves. Calves were infected by direct injection into tissue cages with Pasteurella multocida(type B, serotype 2, then intramuscularly received a range of marbofloxacin doses 24h after inoculation. The ratio of 24h area under the concentration-time curve divided by the minimum inhibitory concentration or the mutant prevention concentration (AUC24h/MIC or AUC24h/MPC was the pharmacokinetic-pharmacodynamic (PK/PD index that best described the effectiveness of marbofloxacin against Pasteurella multocida (R2=0.8514 by nonlinear regression analysis. Marbofloxacin exhibited a good antimicrobial activity in vivo. The levels of AUC24h/MIC and AUC24h/MPC that produced 50% (1.5log10CFU/mL reduction and 90% (3log10CFU/mL reduction of maximum response were 18.60h and 50.65h, 4.67h and 12.89h by using sigmoid Emax model WINNONLIN software, respectively. The in vivo PK/PD integrated methods by tissue cage model display the advantage of the evaluation of antimicrobial activity and the optimization of the dosage regimen for antibiotics in the presence of the host defenses, especially in target animal of veterinary interest.

  6. The UNESCO-IHP Working Group on Land Subsidence: Four Decades of International Contributions to Hydrogeological Related Subsidence Research and Knowledge Exchange (United States)

    Galloway, D. L.; Carreon-Freyre, D.; Teatini, P.; Ye, S.


    Subsidence is globally prevalent and because much of it is related to hydrological processes affected by human development of local land and water resources, "Land Subsidence" was included in the UNESCO programme of the International Hydrological Decade (IHD), 1965-1974 and an ad hoc working group on land subsidence was formed. In 1975 subsidence was retained under the framework of the UNESCO IHP (subproject 8.4: "Investigation of Land Subsidence due to Groundwater Exploitation"), and UNESCO IHP formerly codified the Working Group on Land Subsidence (WGLS). In 1984 the WGLS produced a comprehensive guidebook to serve scientists and engineers, confronting land subsidence problems, particularly in developing countries ($other/unesdoc/pdf/065167eo.pdf). During the IHD, UNESCO IHP convened the 1st International Symposium on Land Subsidence in 1969 in Tokyo, Japan. In collaboration with UNESCO IHP, IAHS, and other scientific organizations, the WGLS has convened eight more International Symposia on Land Subsidence in different countries in Asia, Europe and North America. The 9 published symposia proceedings constitute an important source of global subsidence research and case studies during the past 45 years, covering both anthropogenic and natural subsidence processes. Currently, the WGLS comprising 20 subsidence experts from 9 countries promotes and facilitates the international exchange of information regarding the design, implementation and evaluation of risk assessments and mitigation measures, the definition of water and land resource-management strategies that support sustainable development in areas vulnerable to subsidence (, and the assessment of related geological risks such as earth fissuring and fault activation ( The WGLS has become an important global leader in promoting subsidence awareness, scientific research and its application to subsidence monitoring, analysis and management.

  7. Les subsidences provoquées par la production des fluides souterrains Subsidence Induced by the Production of Fluids

    Directory of Open Access Journals (Sweden)

    Bouteca M.


    Full Text Available Cet article est consacré à l'étude de l'affaissement de la surface du sol provoqué par la production de fluides (eau, hydrocarbures. On présente d'abord les méthodes disponibles pour mesurer cette subsidence, qui atteignent aujourd'hui une grande précision. A partir des cas répertoriés dans la littérature, on met en évidence les mécanismes qui sont à l'origine de la subsidence : compaction du réservoir et compaction des aquitards en relation avec la déplétion, mécanismes liés à l'injection de fluides dans certains cas particuliers (fluage thermique, action de l'eau sur la craie. Ces mécanismes doivent être pris en compte par des modèles progressivement enrichis par la description géologique, pétrophysique et mécanique confrontée aux mesures en place. Le contrôle de la subsidence repose sur le contrôle de la pression en place, maintenue par un fluide compatible avec la formation. Si ce contrôle est mis en oeuvre assez tôt le risque de subsidence est pratiquement nul. This article is devoted to the investigation of soil surface subsidence caused by the production of fluids (water, oil and gas. It first describes the methods available for measuring this subsidence, methods that have become extremely accurate today. Cases are selected from the literature to identify the mechanisms causing subsidence: reservoir and aquifer compaction associated with depletion, mechanisms connected with fluid injections in specific cases (thermal creep, action of water on chalk. These mechanisms must be taken into account by models progressively enriched with geological, petrophysical and mechanical descriptions, substantiated by in situ measurements. Subsidence control demands the control of the in situ pressure, maintained by a fluid compatible with the formation. If this control is applied early enough, the risk of subsidence is virtually nil.

  8. Subsidence and settlement and their effect on shallow land burial

    International Nuclear Information System (INIS)

    Abeele, W.V.


    Subsidence and settlement are phenomena that are much more destructive than generally thought. In shallow land burials they may lead to cracking of the overburden and eventual exposure and escape of waste material. The primary causes are consolidation and cave-ins. Laboratory studies performed at Los Alamos permit us to predict settlement caused by consolidation or natural compaction of the crushed tuff overburden. Examples of expected settlement and subsidence are calculated based on the known geotechnical characteristics of crushed tuff. The same thing is done for bentonite/tuff mixes because some field experiments were performed using this additive (bentonite) to reduce the hydraulic conductivity of the crushed tuff. Remedial actions, i.e., means to limit the amount of settlement, are discussed. Finally, we briefly comment on our current field experiment, which studies the influence of subsidence on layered systems, in general, and on biobarriers, in particular. 16 references, 7 figures, 5 tables

  9. Investigation of a subsidence event near Flushing, Ohio

    International Nuclear Information System (INIS)

    Ledney, C.M.; Hawk, J.L.


    An investigation was undertaken to determine the cause and extent of events which caused problems to a number of residences along State Route 149 near Flushing, Belmont County, Ohio. The events began in 1988 and continued through 1991 and affected nine homes. The type of problems occurring, as well as surface effects, compared to available mine maps of the area, indicated the problems were caused by subsidence from coal mining. The mining occurred in the Pittsburgh seam at a depth of between 180 and 220 feet. The mining beneath the site took place between 1975 and 1977 and was of the room and pillar type. A subsurface investigation was performed, along with ''down the hole'' video camera inspections to provide necessary subsurface information for analysis of the subsidence event. Factors of safety were calculated for pillars throughout the mine. Based on this analysis, it was determined that pillar failure caused the subsidence event. Once a determination was made as to the likely cause of the subsidence, the data was re-examined to determine the possible location of pillar failure, as well as the type and extent of subsidence. This analysis involved the use of RQD versus depth plots and the compilation of isopach maps of the mine overburden and the Sewickley Sandstone. The trend of the two maps suggested that a relationship existed between the sandstone thickness, the overburden and the surface expression of the subsidence. In order to determine this relationship, the two maps were combined into a second order map showing the mine overburden--Sewickley Sandstone thickness ratios. The combination was accomplished by computer matrix operations using the grid values of the two previous maps that were generated by kriging. It was concluded that the ratio of the Sewickley Sandstone thickness to the mine overburden had a tremendous effect on the amount of damage that occurred to specific residences

  10. Biomechanics of Nested Transforaminal Lumbar Interbody Cages. (United States)

    Soriano-Baron, Hector; Newcomb, Anna G U S; Malhotra, Devika; de Tranaltes, Kaylee; Martinez-Del-Campo, Eduardo; Reyes, Phillip M; Crawford, Neil R; Theodore, Nicholas; Tumialán, Luis M


    Arthrodesis is optimized when the structural graft occupies most of the surface area within a disc space. The transforaminal corridor inherently limits interbody size. To evaluate the biomechanical implications of nested interbody spacers (ie, a second curved cage placed behind a first) to increase disc space coverage in transforaminal approaches. Seven lumbar human cadaveric specimens (L3-S1) underwent nondestructive flexibility and axial compression testing intact and after transforaminal instrumentation at L4-L5. Specimens were tested in 5 conditions: (1) intact, (2) interbody, (3) interbody plus bilateral pedicle screws and rods (PSR), (4) 2 nested interbodies, and (5) 2 nested interbodies plus PSR. Mean range of motion (ROM) with 1 interbody vs 2 nested interbodies, respectively, was: flexion, 101% vs 85%; extension, 97% vs 92%; lateral bending, 127% vs 132%; and axial rotation, 145% vs 154%. One interbody and 2 nested interbodies did not differ significantly by loading mode (P > .10). With PSR, ROM decreased significantly compared with intact, but not between interbody and interbody plus PSR or 2 interbodies plus PSR (P > .80). Mean vertical height during compressive loading (ie, axial compressive stiffness) was significantly different with 2 nested interbodies vs 1 interbody alone (P < .001) (compressive stiffness, 89% of intact vs 67% of intact, respectively). Inserting a second interbody using a transforaminal approach is anatomically feasible and nearly doubles the disc space covered without affecting ROM. Compressive stiffness significantly increased with 2 nested interbodies, and foraminal height increased. Evaluation of the clinical safety and efficacy of nested interbodies is underway.

  11. Net-bottom Cage Inserts for Water Bird Casualties

    Directory of Open Access Journals (Sweden)

    Jackie Belle


    Full Text Available My Bright Idea is a net-bottomed cage insert, which is used to support pelagic avian casualties. The idea was designed and modified by the International Bird Rescue in California (Bird Rescue.

  12. Environmental impact analysis of aquaculture in net cages in a ...

    African Journals Online (AJOL)

    Environmental impact analysis of aquaculture in net cages in a Brazilian water reservoir, based in zooplankton communities. Maria Cristina Crispim, Karla Patrícia Ponte Araújo, Hênio do Nascimento Melo Júnior ...

  13. La cage qui cache : La Cage Dorée de Ruben Alves

    Directory of Open Access Journals (Sweden)

    Cristina Marinho


    Full Text Available The French Comedy La Cage Dorée (produced by the luso descendant Ruben Alves, 2013 success seems to be mainly due to its clichés of Portuguese epics in Paris, and its miseries may not have been underlined enough. Thus, under this apparently naif portrait an intriguing painting of Portuguese immigrants’ French dis-integration may really be hiding, which is the aim of this essay, on one hand, to bring out and, on the other one, to clarify, by questioning comparative critical common denominators of the two countries.

  14. La cage qui cache : La Cage Dorée de Ruben Alves

    Directory of Open Access Journals (Sweden)

    Cristina Marinho


    Full Text Available The French Comedy La Cage Dorée (produced by the luso descendant Ruben Alves, 2013 success seems to be mainly due to its clichés of Portuguese epics in Paris, and its miseries may not have been underlined enough. Thus, under this apparently naif portrait an intriguing painting of Portuguese immigrants’ French dis-integration may really be hiding, which is the aim of this essay, on one hand, to bring out and, on the other one, to clarify, by questioning comparative critical common denominators of the two countries.

  15. Subsidence monitoring program at Cyprus Coal's Colorado operations

    International Nuclear Information System (INIS)

    Stewart, C.L.; Shoemaker, J.E.


    Published subsidence data for the western United States is limited in comparison with data for the east. This paper summarizes the results of a subsidence monitoring program above two longwall panels at the Foidel Creek Mine located in northwest Colorado. The monitoring area is characterized by overburden ranging from 1000 ft to 1100 ft in thickness. the surface slope parallels the dip of the bedding at approximately 5 deg. Average mining height is 9 ft. Smax averaged 3.4 ft. Draw angles averaged 15 deg for up-dip ribsides and 19 deg for down-dip ribsides. A site-specific profile function is developed from the data

  16. Cenozoic uplift and subsidence in the North Atlantic region

    DEFF Research Database (Denmark)

    Anell, Ingrid Anna Margareta; Thybo, Hans; Artemieva, Irina


    The topographic evolution of the "passive" margins of the North Atlantic during the last 65 Myr is the subject of extensive debate due to inherent limitations of the geological, geomorphological and geophysical methods used for studies of uplift and subsidence. We have compiled a database of sign...... and the surrounding areas. (2) A regional increase in subsidence in the offshore marginal areas of Norway, the northern North Sea, the northern British Isles and west Greenland took place in the Eocene (ca 57-35 Ma). (3) The Oligocene and Miocene (35-5 Ma) were characterized by regional tectonic quiescence, with only...

  17. Skull Subsidence due to Periosteum Defect following Craniotomy in a Child. (United States)

    Arishima, Hidetaka; Akazawa, Ayumi; Kikuta, Ken-Ichiro


    We report a case of a 7-year-old child with a cranial deformity secondary to a craniotomy for an intracranial hematoma. He suffered from an acute epidural hematoma with a lineal fracture of the right temporal bone following a severe head injury. A large question mark-shaped skin flap with the periosteum and temporal muscle was created for a decompressive craniectomy; however, neither the acute epidural hematoma nor brain swelling was severe, and we performed a small craniotomy compared with the skin flap without a decompressive craniectomy. Eighteen months after the operation, he complained of skull deformity with a mild depression of the forehead. Axial and 3-dimensional computed tomography showed thinness and subsidence of the frontoparietal bone around the replaced bone flap, corresponding to the skin flap with the periosteum defect. We suggest that the periosteum defect following creation of the skin flap during surgery prevented normal growth of the skull, which caused the thinness and subsidence of the frontoparietal bone. Preservation and cooptation of the periosteum should be performed during neurological surgeries in babies and children to prevent skull deformity. © 2016 S. Karger AG, Basel.

  18. Land subsidence and caprock dolines caused by subsurface gypsum dissolution and the effect of subsidence on the fluvial system in the Upper Tigris Basin (between Bismil Batman, Turkey) (United States)

    Doğan, Uğur


    Karstification-based land subsidence was found in the Upper Tigris Basin with dimensions not seen anywhere else in Turkey. The area of land subsidence, where there are secondary and tertiary subsidence developments, reaches 140 km 2. Subsidence depth ranges between 40 and 70 m. The subsidence was formed as a result of subsurface gypsum dissolution in Lower Miocene formation. Although there are limestones together with gypsum and Eocene limestone below them in the area, a subsidence with such a large area is indicative of karstification in the gypsum. The stratigraphical cross-sections taken from the wells and the water analyses also verify this fact. The Lower Miocene gypsum, which shows confined aquifer features, was completely dissolved by the aggressive waters injected from the top and discharged through by Zellek Fault. This resulted in the development of subsidence and formation of caprock dolines on loosely textured Upper Miocene-Pliocene cover formations. The Tigris River runs through the subsidence area between Batman and Bismil. There are four terrace levels as T1 (40 m), T2 (30 m), T3 (10 m) and T4 (4-5 m) in the Tigris River valley. It was also found that there were some movements of the levels of the terraces in the valley by subsidence. The subsidence developed gradually throughout the Quaternary; however no terrace was formed purely because of subsidence.

  19. Caged molecular beacons: controlling nucleic acid hybridization with light. (United States)

    Wang, Chunming; Zhu, Zhi; Song, Yanling; Lin, Hui; Yang, Chaoyong James; Tan, Weihong


    We have constructed a novel class of light-activatable caged molecular beacons (cMBs) that are caged by locking two stems with a photo-labile biomolecular interaction or covalent bond. With the cMBs, the nucleic acid hybridization process can be easily controlled with light, which offers the possibility for a high spatiotemporal resolution study of intracellular mRNAs. © The Royal Society of Chemistry 2011

  20. Musica come divenire. Il paesaggio sonoro secondo John cage

    Directory of Open Access Journals (Sweden)

    Francesca Aste


    Full Text Available John Cage ha dedicato tutta la sua vita all’indagine delle possibilità di relazione dell’uomo con i suoni che lo circondano, allargando il campo dell’arte musicale a quello dell’etica e dell’ecologia. Cage non si è occupato di soundscape come un genere compositivo specifico, come forse oggi potremmo identificarlo, tuttavia l’ambiente occupa un ruolo centrale in relazione al suo modo di comporre.

  1. Mitochondria mediate septin cage assembly to promote autophagy of Shigella. (United States)

    Sirianni, Andrea; Krokowski, Sina; Lobato-Márquez, Damián; Buranyi, Stephen; Pfanzelter, Julia; Galea, Dieter; Willis, Alexandra; Culley, Siân; Henriques, Ricardo; Larrouy-Maumus, Gerald; Hollinshead, Michael; Sancho-Shimizu, Vanessa; Way, Michael; Mostowy, Serge


    Septins, cytoskeletal proteins with well-characterised roles in cytokinesis, form cage-like structures around cytosolic Shigella flexneri and promote their targeting to autophagosomes. However, the processes underlying septin cage assembly, and whether they influence S. flexneri proliferation, remain to be established. Using single-cell analysis, we show that the septin cages inhibit S. flexneri proliferation. To study mechanisms of septin cage assembly, we used proteomics and found mitochondrial proteins associate with septins in S. flexneri-infected cells. Strikingly, mitochondria associated with S. flexneri promote septin assembly into cages that entrap bacteria for autophagy. We demonstrate that the cytosolic GTPase dynamin-related protein 1 (Drp1) interacts with septins to enhance mitochondrial fission. To avoid autophagy, actin-polymerising Shigella fragment mitochondria to escape from septin caging. Our results demonstrate a role for mitochondria in anti-Shigella autophagy and uncover a fundamental link between septin assembly and mitochondria. © 2016 The Authors. Published under the terms of the CC BY 4.0 license.

  2. Caged Protein Prenyltransferase Substrates: Tools for Understanding Protein Prenylation

    Energy Technology Data Exchange (ETDEWEB)

    DeGraw, Amanda J.; Hast, Michael A.; Xu, Juhua; Mullen, Daniel; Beese, Lorena S.; Barany, George; Distefano, Mark D. (Duke); (UMM)


    Originally designed to block the prenylation of oncogenic Ras, inhibitors of protein farnesyltransferase currently in preclinical and clinical trials are showing efficacy in cancers with normal Ras. Blocking protein prenylation has also shown promise in the treatment of malaria, Chagas disease and progeria syndrome. A better understanding of the mechanism, targets and in vivo consequences of protein prenylation are needed to elucidate the mode of action of current PFTase (Protein Farnesyltransferase) inhibitors and to create more potent and selective compounds. Caged enzyme substrates are useful tools for understanding enzyme mechanism and biological function. Reported here is the synthesis and characterization of caged substrates of PFTase. The caged isoprenoid diphosphates are poor substrates prior to photolysis. The caged CAAX peptide is a true catalytically caged substrate of PFTase in that it is to not a substrate, yet is able to bind to the enzyme as established by inhibition studies and X-ray crystallography. Irradiation of the caged molecules with 350 nm light readily releases their cognate substrate and their photolysis products are benign. These properties highlight the utility of those analogs towards a variety of in vitro and in vivo applications.

  3. Homogenized boundary conditions and resonance effects in Faraday cages (United States)

    Hewitt, I. J.


    We present a mathematical study of two-dimensional electrostatic and electromagnetic shielding by a cage of conducting wires (the so-called ‘Faraday cage effect’). Taking the limit as the number of wires in the cage tends to infinity, we use the asymptotic method of multiple scales to derive continuum models for the shielding, involving homogenized boundary conditions on an effective cage boundary. We show how the resulting models depend on key cage parameters such as the size and shape of the wires, and, in the electromagnetic case, on the frequency and polarization of the incident field. In the electromagnetic case, there are resonance effects, whereby at frequencies close to the natural frequencies of the equivalent solid shell, the presence of the cage actually amplifies the incident field, rather than shielding it. By appropriately modifying the continuum model, we calculate the modified resonant frequencies, and their associated peak amplitudes. We discuss applications to radiation containment in microwave ovens and acoustic scattering by perforated shells. PMID:27279775

  4. Clinical and radiological outcome after anterior cervical discectomy and fusion with stand-alone empty polyetheretherketone (PEEK) cages. (United States)

    Shiban, Ehab; Gapon, Karina; Wostrack, Maria; Meyer, Bernhard; Lehmberg, Jens


    To evaluate long-term results after one-, two-, and three-level anterior cervical discectomy and fusion (ACDF) with stand-alone empty polyetheretherketone (PEEK) cages. We performed a retrospective review of a consecutive patient cohort that underwent ACDF with stand-alone empty PEEK cages between 2007 and 2010 with a minimum follow-up of 12 months. Radiographic follow-up included static and flexion/extension radiographs. Changes in the operated segments were measured and compared to radiographs directly after surgery. Clinical outcome was evaluated by a physical examination, pain visual analog scale (VAS), and health-related quality of life (HRQL) using the EuroQOL questionnaire (EQ-5D). Analysis of associations between fusion, subsidence, cervical alignment, and clinical outcome parameters were performed. Of 407 consecutive cases, 318 met all inclusion criteria. Follow-up data were obtained from 265 (83 %) cases. The mean age at presentation was 55 years and 139 patients were male (52 %). In the sample, 127, 125, and 13 patients had one-, two-, and three-level surgeries, respectively; 132 (49 %) presented with spondylotic cervical myelopathy and 133 (50 %) with cervical radiculopathy. Fusion was achieved in 85, 95, and 94 % of segments in one-, two-, and three-level surgeries, respectively. Non-fusion was associated with higher VAS pain levels. Radiographic adjacent segment disease (ASD) was observed in 20, 29, and 15 % in one-, two-, and three-level surgeries, respectively. ASD was associated with lower HRQL. Subsidence was observed in 25, 27, and 15 % of segments in one-, two-, and three-level surgeries, respectively. However, this had no influence on clinical outcome. Follow-up operations for symptomatic adjacent disc disease and implant failure at index level were needed in 16 (6 %) and four (1.5 %) cases, respectively. Younger age was associated with better clinical outcome. Multilevel surgery favored better myelopathy outcomes and fusion reduced overall

  5. TiN thin film deposition by cathodic cage discharge: effect of cage configuration and active species

    International Nuclear Information System (INIS)

    De Freitas Daudt, N; Cavalcante Braz, D; Alves Junior, C; Pereira Barbosa, J C; Barbalho Pereira, M


    Plasma cathodic cage technique was developed recently in order to eliminate phenomena such as edge effects and overheating, which occur during conventional nitriding processes. In this work, the effect of plasma active species and cage configurations during thin film deposition of TiN were studied. This compound was chosen because its properties are very sensitive to slight variations in chemical composition and film thickness, becoming a good monitoring tool in fabrication process control. In order to verify the effect of cage geometry on the discharge and characteristics of the grown film, a cage made of titanium was used with different numbers and distribution of holes. Furthermore, different amounts of hydrogen were added to the Ar + N2 plasma atmosphere. Flow rates of Ar and N2 gas were fixed at 4 and 3 sccm, respectively and flow rates of H 2 gas was 0, 1 and 2 sccm. Plasma species, electrical discharge and physical characteristics of the grown film were analyzed by Optical Emission Spectroscopy (OES), Atomic Force Microscopy (AFM), X-Ray Diffraction. It was observed by OES that the luminous intensity associated to Hα species is not proportional to flow rate of H 2 gas. Electrical efficiency of the system, crystal structure and topography of the TiN film are strongly influenced by this behavior. For constant flow rate of H 2 gas, it was found that with more holes at the top of the cage, deposition rate, crystallinity and roughness are higher, if compared to cages with a small number of holes at the top of cage. On the other hand, the opposite behavior was observed when more holes were located at the sidewall of cage.

  6. Multicomponent Protein Cage Architectures for Photocatalysis

    Energy Technology Data Exchange (ETDEWEB)

    Gupta, Arunava [Univ. of Alabama, Tuscaloosa, AL (United States); Prevelige, Peter E [Univ. of Alabama, Birmingham, AL (United States)


    The primary goal of the project was to develop protein-templated approaches for the synthesis and directed assembly of semiconductor nanomaterials that are efficient for visible light absorption and hydrogen production. In general, visible-light-driven photocatalysis reactions exhibit low quantum efficiency for solar energy conversion primarily because of materials-related issues and limitations, such as the control of the band gap, band structure, photochemical stability, and available reactive surface area of the photocatalyst. Synthesis of multicomponent hierarchical nano-architectures, consisting of semiconductor nanoparticles (NPs) with desired optical properties fabricated to maximize spatial proximity for optimum electron and energy transfer represents an attractive route for addressing the problem. Virus capsids are highly symmetrical, self-assembling protein cage nanoparticles that exist in a range of sizes and symmetries. Selective deposition of inorganic, by design, at specific locations on virus capsids affords precise control over the size, spacing, and assembly of nanomaterials, resulting in uniform and reproducible nano-architectures. We utilized the self-assembling capabilities of the 420 subunit, 60 nm icosahedral, P22 virus capsid to direct the nucleation, growth, and proximity of a range of component materials. Controlled fabrication on the exterior of the temperature stable shell was achieved by genetically encoding specific binding peptides into an externally exposed loop which is displayed on each of the 420 coat protein subunits. Localization of complimentary materials to the interior of the particle was achieved through the use “scaffolding-fusion proteins. The scaffolding domain drives coat protein polymerization resulting in a coat protein shell surrounding a core of approximately 300 scaffolding/fusion molecules. The fusion domain comprises a peptide which specifically binds the semiconductor material of interest.

  7. Subsidence analysis Forsmark nuclear power plant - unit 1

    International Nuclear Information System (INIS)

    Bono, Nancy; Fredriksson, Anders; Maersk Hansen, Lars


    On behalf of SKB, Golder Associates Ltd carried out a risk analysis of subsidence during Forsmark nuclear power plant in the construction of the final repository for spent nuclear fuel near and below existing reactors. Specifically, the effect of horizontal cracks have been studied

  8. Who Subsidizes Whom? An Analysis of Educational Costs and Revenues (United States)

    Gillen, Andrew; Denhart, Matthew; Robe, Jonathan


    Conventional wisdom holds that colleges and universities heavily subsidize their students. This assertion seems correct, given that total spending per student is almost always in excess of per student tuition payments. However, as the authors show in this report, the conventional wisdom is wrong because it inappropriately compares only one revenue…

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

    Directory of Open Access Journals (Sweden)

    Ratan Das


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

  10. Estimating the distribution of salt cavern squeeze using subsidence measurements

    NARCIS (Netherlands)

    Fokker, P.A.; Visser, J.


    We report a field study on solution mining of magnesium chloride from bischofite layers in the Netherlands at depths between 1500 and 1850 m. Subsidence that was observed in the area is due to part of the brine production being realized by cavern squeeze; some of which were connccted. Wc used an


    Directory of Open Access Journals (Sweden)

    Алексей Алексеевич Бурцев


    Full Text Available The paper studied the effect of oil content on the mechanical properties of soil subsidence - Ek modulus and compressibility factor m0, obtained in the laboratory with the help of artificial impregnation oil soil samples. A comparison of the above parameters with samples of the same soil in the natural and water-saturated conditions has been perfomed.

  12. Land subsidence and hydrodynamic compaction of sedimentary basins

    Directory of Open Access Journals (Sweden)

    H. Kooi


    Full Text Available A one-dimensional model is used to investigate the relationship between land subsidence and compaction of basin sediments in response to sediment loading. Analysis of the model equations and numerical experiments demonstrate quasi-linear systems behaviour and show that rates of land subsidence due to compaction: (i can attain a significant fraction (>40% of the long-term sedimentation rate; (ii are hydrodynamically delayed with respect to sediment loading. The delay is controlled by a compaction response time τc that can reach values of 10-5-107 yr for thick shale sequences. Both the behaviour of single sediment layers and multiple-layer systems are analysed. Subsequently the model is applied to the coastal area of the Netherlands to illustrate that lateral variability in compaction-derived land subsidence in sedimentary basins largely reflects the spatial variability in both sediment loading and compaction response time. Typical rates of compaction-derived subsidence predicted by the model are of the order of 0.1 mm/yr but may reach values in excess of 1 mm/yr under favourable conditions.

  13. How large-scale subsidence affects stratocumulus transitions

    Directory of Open Access Journals (Sweden)

    J. J. van der Dussen


    Full Text Available Some climate modeling results suggest that the Hadley circulation might weaken in a future climate, causing a subsequent reduction in the large-scale subsidence velocity in the subtropics. In this study we analyze the cloud liquid water path (LWP budget from large-eddy simulation (LES results of three idealized stratocumulus transition cases, each with a different subsidence rate. As shown in previous studies a reduced subsidence is found to lead to a deeper stratocumulus-topped boundary layer, an enhanced cloud-top entrainment rate and a delay in the transition of stratocumulus clouds into shallow cumulus clouds during its equatorwards advection by the prevailing trade winds. The effect of a reduction of the subsidence rate can be summarized as follows. The initial deepening of the stratocumulus layer is partly counteracted by an enhanced absorption of solar radiation. After some hours the deepening of the boundary layer is accelerated by an enhancement of the entrainment rate. Because this is accompanied by a change in the cloud-base turbulent fluxes of moisture and heat, the net change in the LWP due to changes in the turbulent flux profiles is negligibly small.

  14. Subsidence History of the Rukwa Rift in South West Tanzania ...

    African Journals Online (AJOL)

    The variation in subsidence rate during rift basin development is a good indication for the Geodynamic history of a sedimentary basin. The sedimentary section of Ivuna Well is herein used to explain the structural evolution of Rukwa Basin within the Western Rift of the East African Rift System. The sedimentary record of ...

  15. Subsidence patterns in the Nigerian sector of Benin (Dahomey ...

    African Journals Online (AJOL)

    The application of one-dimensional (1-D) backstripping analysis was used to determine subsidence patterns in three offshore wells (Ayetoro – 1, Baba – 1 and Epiya – 1) located in the Nigeria sector of Benin (Dahomey) Basin. Biostratigraphic data obtained in the three wells indicated that the oldest sediment penetrated ...

  16. Tectonics and subsidence evolution of the Sirt Basin, Libya

    NARCIS (Netherlands)

    Abadi, A.M.; Wees, J.D. van; Dijk, P.M. van; Cloetingh, S.A.P.L.


    Backstripping analysis of 225 wells located within the Sirt Basin (Fig. 1) provide new constraints on the Sirt Basin development. Four coherent tectonic phases from Late Jurassic to present. The presentation of contour maps of subsidence and crustal stretching allows to visualize spatial and

  17. Subsidence characterization and modeling for engineered facilities in Arizona, USA

    Directory of Open Access Journals (Sweden)

    M. L. Rucker


    Full Text Available Several engineered facilities located on deep alluvial basins in southern Arizona, including flood retention structures (FRS and a coal ash disposal facility, have been impacted by up to as much as 1.8 m of differential land subsidence and associated earth fissuring. Compressible basin alluvium depths are as deep as about 300 m, and historic groundwater level declines due to pumping range from 60 to more than 100 m at these facilities. Addressing earth fissure-inducing ground strain has required alluvium modulus characterization to support finite element modeling. The authors have developed Percolation Theory-based methodologies to use effective stress and generalized geo-material types to estimate alluvium modulus as a function of alluvium lithology, depth and groundwater level. Alluvial material modulus behavior may be characterized as high modulus gravel-dominated, low modulus sand-dominated, or very low modulus fines-dominated (silts and clays alluvium. Applied at specific aquifer stress points, such as significant pumping wells, this parameter characterization and quantification facilitates subsidence magnitude modeling at its' sources. Modeled subsidence is then propagated over time across the basin from the source(s using a time delay exponential decay function similar to the soil mechanics consolidation coefficient, only applied laterally. This approach has expanded subsidence modeling capabilities on scales of engineered facilities of less than 2 to more than 15 km.

  18. At Whose Service? Subsidizing Services and the Skill Premium

    NARCIS (Netherlands)

    van Groezen, B.J.A.M.; Meijdam, A.C.


    In this paper we investigate the effects of subsidizing low-skilled, labourintensive services hired by high-skilled individuals in the presence of labour income taxation. Whether such a subsidy can be Paretoimproving depends crucially on the degree of substitutability of both types of labour in the

  19. Subsidized Housing, Public Housing, and Adolescent Violence and Substance Use (United States)

    Leech, Tamara G. J.


    This study examines the separate relationships of public housing residence and subsidized housing residence to adolescent health risk behavior. Data include 2,530 adolescents aged 14 to 19 who were children of the National the Longitudinal Study of Youth. The author used stratified propensity methods to compare the behaviors of each…

  20. Crustal Structure and Subsidence of the Williston Basin: Evidence from Receiver Function Stacking and Gravity Modeling (United States)

    Song, J.; Liu, K. H.; Yu, Y.; Mickus, K. L.; Gao, S. S.


    The Williston Basin of the northcentral United States and southern Canada is a typical intracratonic sag basin, with nearly continuous subsidence from the Cambrian to the Jurassic. A number of contrasting models on the subsidence mechanism of this approximately circular basin have been proposed. While in principle 3D variations of crustal thickness, layering, and Poisson's ratio can provide essential constraints on the models, thick layers of Phanerozoic sediment with up to 4.5 km thickness prevented reliable determinations of those crustal properties using active or passive source seismic techniques. Specifically, the strong reverberations of teleseismic P-to-S converted waves (a.k.a. receiver functions or RFs) from the Moho and intracrustal interfaces in the loose sedimentary layer can severely contaminate the RFs. Here we use RFs recorded by about 200 USArray and other stations in the Williston Basin and adjacent areas to obtain spatial distributions of the crustal properties. We have found that virtually all of the RFs recorded by stations in the Basin contain strong reverberations, which are effectively removed using a recently developed deconvolution-based filter (Yu et al., 2015, DOI: 10.1002/2014JB011610). A "double Moho" structure is clearly imaged beneath the Basin. The top interface has a depth of about 40 km beneath the Basin, and shallows gradually toward the east from the depocenter. It joins with the Moho beneath the western margin of the Superior Craton, where the crust is about 30 km thick. The bottom interface has a depth of 55 km beneath the Wyoming Craton, and deepens to about 70 km beneath the depocenter. Based on preliminary results of H-k stacking and gravity modeling, we interpret the layer between the two interfaces as a high density, probably eclogized layer. Continuous eclogitization from the Cambrian to the Jurassic resulted in the previously observed rates of subsidence being nearly linear rather than exponential.

  1. Ground subsidence phenomena in Frakadona, West Thessaly, Greece (United States)

    Tsangaratos, Paraskevas; Loupasakis, Constantinos; Ilia, Ioanna


    Ground subsidence is considered among the most frequent geological hazard that usually occurs as a consequence of a number of phenomena, namely: natural compaction of unconsolidated fine - grained deposits, groundwater over - exploitation, peat - oxidation and collapse of underground cavities. The main objective of the present study was to investigate the spatio - temporal patterns of ground deformation in the wider area of Farkadona Municipality in the north-eastern Trikala regional unit, Thessaly, Greece. A set of Synthetic Aperture Radar images, acquired in 1992-2003 by the European Space Agency satellites ERS1 and ERS2 and processed with the Persistent Scatterer Interferometry technique, along with geotechnical data from nearby exploratory boreholes, were used in order to explain the observed deformation. Increasing subsidence rates are observed at almost the entire area within the city complex of Farkadona, which is covered by loose Quaternary sediments of considerable depth. In most cases, the increased deformation rates have caused damages in the form of tensile cracks, mainly along the road network and adjacent buildings. The results of the performed analysis concluded that the geotechnical conditions of the loose deposits occupying the site and also the intensive exploitation of the aquifers are the two main causal factors of the land subsidence phenomena. Additionally, a clear correlation between the subsidence deformation rate and the thickness of the loose deposits has been detected. Besides the geological information, this study made clear that Persistent Scatterer Interferometry could be considered as a valuable tool and cost-efficient method for validating subsidence mechanisms and could serve as an alternative to ground-based measurements.

  2. Stem subsidence of polished and rough double-taper stems (United States)

    Yamada, Kengo; Hirosaki, Kenichi; Takano, Masahiro; Matsumoto, Tadami


    Background and purpose Many clinical reports have indicated that polished hip stems show better clinical results than rough stems of the same geometry. It is still unknown, however, what the mechanical effects are of different surface finishes on the cement at the cement-bone interface. We compared mechanical effects in an in vitro cemented hip arthroplasty model. Methods Two sizes of double-taper polished stems and matt-processed polished stems (rough stems) were fixed into composite femurs. A 1-Hz dynamic load was applied to the stems for 1 million cycles. An 8-h no-load period was set after every 16 h of load. Stem subsidence within the cement, and compressive force and horizontal cement creep at the cement-bone interface, were measured. Results Compared to rough stems, stem subsidence, compressive force and cement creep for polished stems were a maximum of 4, 12, and 7-fold greater, respectively. There was a strong positive correlation between stem subsidence and compressive force for polished stems. In contrast, a strong negative correlation was found between stem subsidence and compressive force for rough stems. There was also a statistically significant relationship between compressive force on the cement and cement creep for the polished stems, but no significant relationship was found for rough stems. Interpretation This is the first evidence that different surface finishes of stems can have different mechanical effects on the cement at the cement-bone interface. Stem subsidence in polished stems resulted in compressive force on the cement and cement creep. The mechanical effects that polished taper stems impart on cement at the cement-bone interface probably contribute to their good long-term fixation and excellent clinical outcome. PMID:19421909

  3. A fusion model used in subsidence prediction in Taiwan

    Directory of Open Access Journals (Sweden)

    S.-J. Wang


    Full Text Available The Taiwan Water Resources Agency uses four techniques to monitor subsidence in Taiwan, namely data from leveling, global positioning system (GPS, multi-level compaction monitoring wells (MCMWs, and interferometry synthetic aperture radar (InSAR. Each data type has advantages and disadvantages and is suitable for different analysis tools. Only MCMW data provide compaction information at different depths in an aquifer system, thus they are adopted in this study. However, the cost of MCMW is high and the number of MCMW is relatively low. Leveling data are thus also adopted due to its high resolution and accuracy. MCMW data provide compaction information at different depths and the experimental data from the wells provide the physical properties. These data are suitable for a physical model. Leveling data have high monitoring density in spatial domain but lack in temporal domain due to the heavy field work. These data are suitable for a black- or grey-box model. Poroelastic theory, which is known to be more conscientious than Terzaghi's consolidation theory, is adopted in this study with the use of MCMW data. Grey theory, which is a widely used grey-box model, is adopted in this study with the use of leveling data. A fusion technique is developed to combine the subsidence predicted results from poroelastic and grey models to obtain a spatially and temporally connected two-dimensional subsidence distribution. The fusion model is successfully applied to subsidence predictions in Changhua, Yunlin, Tainan, and Kaohsiung of Taiwan and obtains good results. A good subsidence model can help the government to make the accurate strategies for land and groundwater resource management.

  4. Investigation of subsidence event over multiple seam mining area

    International Nuclear Information System (INIS)

    Kohli, K.K.


    An investigation was performed to determine the sequence of events which caused the 1987 surface subsidence and related damage to several homes in Walker County, Alabama, USA. Surface affects compared to mine maps indicated the subsidence to be mine related. However, two coal seams had been worked under this area. The upper seam, the American seam, ranged from 250 to 280 feet beneath the surface in the area in question. It was mined-out before 1955 by room-and-pillar method leaving in place narrow-long pillars to support the overburden strata, and abandoned in 1955. The lower seam, the Mary Lee seam, ranged from 650 to 700 feet beneath the surface. The Mary Lee seam had been abandoned in 1966 and subsequently became flooded. The dewatering of the Mary Lee seam workings in 1985 caused the submerged pillars to be exposed to the atmosphere. Due to multiple seam mining and the fact that workings had been inundated then dewatered, a subsurface investigation ensued to determine the sequence and ultimate cause of surface subsidence. Core sample tests with fracture analysis in conjunction with down-the-hole TV camera inspections provided necessary information to determine that the subsidence started in the lower seam and progressed through the upper coal seam to the surface. Evidence from the investigation program established that dewatering of the lower seam workings caused the marginally stable support pillars and the roof to collapse. This failure triggered additional subsidence in the upper seam which broadened the area of influence at the surface


    Directory of Open Access Journals (Sweden)

    Roman Safner


    Full Text Available In the 1970s, Croatia became actively involved in the contemporary trend of breeding fish in floating cages. In addition to various species of marine fishes, breeding was attempted with trout, carp, catfish, cisco and salmon. Of the above freshwater fish species, specific standards were established only for the cage breeding of rainbow trout. Cage breeding of the remaining species remained at the level of occasional attempts, with more of an experimental than a commercial character. The regular attempts to master this technique for cage breeding of warm water freshwater fish species were aimed at achieving the known benefits of such breeding, such as simplicity of implementing technological measures, easier establishment of the breeding system, simpler manipulation, the possibility of denser colonies per unit volume with a high level of production, easier adaptations to market conditions and fewer initial structural investments. Despite the many advantages, the main reasons for the lack of greater implementation of the cage breeding technology for warm water species of freshwater fish include problems in obtaining the appropriate category and quantity of healthy fry, the specificity and applicability of physical and chemical properties of the recipients and human error. In evaluating the advantages and disadvantages, the final decision on the justification of cage breeding for individual warm water freshwater species must be based on both biological and economic factors. Based on the knowledge of cage breeding acquired to date, the rule for virtually all intensive breeding systems is that it is only recommended for those species with high market demand and a high market price. The technology that demands nutrition with highly concentrated feed and other production expenditures is costly, and is therefore not profitable with less expensive fish species. Furthermore, production must be market oriented, i.e. the appropriate market research measures

  6. Impacts of 25 years of groundwater extraction on subsidence in the Mekong delta, Vietnam (United States)

    Many major river deltas in the world are subsiding and consequently become increasingly vulnerable to flooding and storm surges, salinization and permanent inundation. For the Mekong Delta, annual subsidence rates up to several centimetres have been reported. Excessive groundwate...

  7. The future of subsidence modelling: compaction and subsidence due to gas depletion of the Groningen gas field in the Netherlands

    NARCIS (Netherlands)

    Thienen-Visser, K. van; Fokker, P.A.


    The Groningen gas field has shown considerable compaction and subsidence since starting production in the early 1960s. The behaviour is understood from the geomechanical response of the reservoir pressure depletion. By integrating surface movement measurements and modelling, the model parameters can

  8. Biologic activity of cyclic and caged phosphates: a review. (United States)

    Lorke, Dietrich E; Stegmeier-Petroianu, Anka; Petroianu, Georg A


    The recognition in the early 1960s by Morifusa Eto that tri-o-cresyl phosphate (TOCP) is hydroxylated by the cytochrome P450 system to an intermediate that spontaneously cyclizes to a neurotoxic phosphate (saligenin phosphate ester) ignited the interest in this group of compounds. Only the ortho isomer can cyclize and clinically cause Organo Phosphate Induced Delayed Neurotoxicity (OPIDN); the meta and para isomers of tri-cresyl phosphate are not neuropathic because they are unable to form stable cyclic saligenin phosphate esters. This review identifies the diverse biological effects associated with various cyclic and caged phosphates and phosphonates and their possible use. Cyclic compounds that inhibit acetylcholine esterase (AChE), such as salithion, can be employed as pesticides. Others are neurotoxic, most probably because of inhibition of neuropathy target esterase (NTE). Cyclic phosphates that inhibit lipases, the cyclipostins, possibly represent promising therapeutic avenues for the treatment of type 2 diabetes mellitus and/or microbial infections; those compounds inhibiting β-lactamase may prevent bacterial resistance against β-lactam antibiotics. Naturally occurring cyclic phosphates, such as cyclic AMP, cyclic phosphatidic acid and the ryanodine receptor modulator cyclic adenosine diphosphate ribose, play an important physiological role in signal transduction. Moreover, some cyclic phosphates are GABA-antagonists, while others are an essential component of Molybdenum-containing enzymes. Some cyclic phosphates (cyclophosphamide, ifosfamide) are clinically used in tumor therapy, while the coupling of therapeutic agents with other cyclic phosphates (HepDirect® Technology) allows drugs to be targeted to specific organs. Possible clinical applications of these compounds are considered. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

  9. Development of subsidence profile functions for longwall mining associated with weak floor strata considering time effects

    International Nuclear Information System (INIS)

    Yu, Z.; Chugh, Y.P.; Yang, G.


    Subsidence profile functions for longwall mining in the Illinois Coal Basin were developed for both the headgate and tailgate sides based on field observations of surface subsidence over several longwall panels. One function was applied to predict the subsidence profile for a longwall panel in another Illinois Coal Basin mine, where a good correlation between the predicted and measured results was achieved. Attempts were also made to develop subsidence profile functions including time effect. 4 refs., 9 figs., 1 tab

  10. Groundwater Pumping Decisions and Land Subsidence in the Southern Chesapeake Bay Region of Virginia


    Wade, Christopher Michael


    Land subsidence is the gradual settling or sudden sinking of the earth's surface. According to the United States Geological Survey more than 80% of identified subsidence in the United States is a result of groundwater removal. Due to the hydrologic structure and reliance on the Potomac Aquifer, the Southern Chesapeake Bay region of Virginia has suffered from land subsidence since the 1940s. In coastal regions, land subsidence can increase the risk of flooding. This paper presents a mathematic...

  11. Simulating the hydrologic cycle in coal mining subsidence areas with a distributed hydrologic model


    Jianhua Wang; Chuiyu Lu; Qingyan Sun; Weihua Xiao; Guoliang Cao; Hui Li; Lingjia Yan; Bo Zhang


    Large-scale ground subsidence caused by coal mining and subsequent water-filling leads to serious environmental problems and economic losses, especially in plains with a high phreatic water level. Clarifying the hydrologic cycle in subsidence areas has important practical value for environmental remediation, and provides a scientific basis for water resource development and utilisation of the subsidence areas. Here we present a simulation approach to describe interactions between subsidence a...

  12. Comparison of water-level, extensometric, DInSAR and simulation data for quantification of subsidence in Murcia City (SE Spain) (United States)

    Tessitore, S.; Fernández-Merodo, J. A.; Herrera, G.; Tomás, R.; Ramondini, M.; Sanabria, M.; Duro, J.; Mulas, J.; Calcaterra, D.


    Subsidence due to groundwater overexploitation has been recognized in the metropolitan area of Murcia (25 km2) in south-eastern Spain since the early 1990s. Previous published works have focused their attention on land subsidence that occurred during the drought period between 1995 and 2008. This work first analyzes the groundwater recovery that has occurred since 2008 and then determines the kind of associated ground deformation detected by the new extensometric data. Subsequently, subsidence time series are computed on 24 geotechnical boreholes scattered throughout the study area by means of a hydro-mechanical finite element code and a linear-elastic constitutive law. A spatio-temporal interpolation of the numerically modeled surface displacements is performed over the whole domain and compared with extensometers and DInSAR-derived displacement maps in two different periods: the drought period from 2004 to 2008, and the recovery period from 2008 to 2012. In spite of the limited information on the geomechanical parameters characterizing the modelled geological formations, the proposed approach is able to discriminate areas where the soils have an elastic behavior (small differences in the comparisons) or an elasto-plastic behavior (large differences in the comparisons). This zonation enhances the understanding of the subsidence phenomenon in Murcia City and could prevent, from a quantitatively point of view, future severe subsidence due to aquifer overexploitation.

  13. Understanding Mississippi Delta Subsidence through Stratigraphic and Geotechnical Analysis of a Continuous Holocene Core at a Subsidence Superstation (United States)

    Bridgeman, J.; Tornqvist, T. E.; Jafari, N.; Allison, M. A.


    Land-surface subsidence can be a major contributor to the relative sea-level rise that is threatening coastal communities. Loosely constrained subsidence rate estimates across the Mississippi Delta make it difficult to differentiate between subsidence mechanisms and complicate modeling efforts. New data from a nearly 40 m long, 12 cm diameter core taken during the installation of a subsidence monitoring superstation near the Mississippi River, SW of New Orleans, provides insight into the stratigraphic and geotechnical properties of the Holocene succession. Stratigraphically, the core can be grouped into three sections. The top 12 m is dominated by clastic overbank sediment with interspersed organic-rich layers. The middle section, 12-35 m consists predominately of mud, and the bottom section, 35-38.7 m, is marked by a transition into a Holocene-aged basal peat (11,350-11,190 cal BP) which overlies densely packed Pleistocene sediment. Radiocarbon and OSL ages show up to 6 m of vertical displacement since 3,000 cal BP. We infer that most of this was due to compaction of the thick underlying mud package. The top ­­­­­ 70 cm of the core is a peat that represents the modern marsh surface and is inducing minimal surface loading. This is consistent with the negligible shallow subsidence rate as seen at a nearby rod-surface elevation table - marker horizon station and the initial strainmeter data. Future compaction scenarios for the superstation can be modeled from the stratigraphic and geotechnical properties of the core, including the loading from the planned Mid-Barataria sediment diversion which is expected to dramatically change the coastal landscape in this region.

  14. Compression of the Seventh Cervical Vertebra Following C6-7 and C7-T1 Discectomy, PEEK Cage Implantation in these Intervertebral Spaces, and Management of this Complication in a Patient with Multiple Myeloma

    Directory of Open Access Journals (Sweden)

    Salih Gulsen


    Herein we present a case that we think exemplifies the management of cervical disc herniation and its complications. Consecutive multilevel cervical discectomy and placement of PEEK cages between the intervertebral cervical disc spaces may cause compression fracture of the vertebrae located between the PEEK cages in osteoporotic patients under continuous corticosteroid treatment¾whether or not they  have MM; therefore, we recommend use of an anterior plate to prevent this complication.

  15. 24 CFR 982.521 - Rent to owner in subsidized project. (United States)


    ... URBAN DEVELOPMENT SECTION 8 TENANT BASED ASSISTANCE: HOUSING CHOICE VOUCHER PROGRAM Rent and Housing Assistance Payment § 982.521 Rent to owner in subsidized project. (a) Applicability to subsidized project. This section applies to a program tenancy in any of the following types of federally subsidized project...

  16. 3D characterization of Holocene peat in the Netherlands : Implications for coastal-deltaic subsidence

    NARCIS (Netherlands)

    Koster, K.


    Human-induced subsidence threatens many coastal-deltaic plains, due to the amplifying effects it has on sea-level rise and flood risk. In the coastal-deltaic plain of the Netherlands, subsidence is primarily caused by the compression and oxidation of Holocene peat. The understanding of subsidence in

  17. Measuring Spatiotemporal Features of Land Subsidence, Groundwater Drawdown, and Compressible Layer Thickness in Beijing Plain, China


    Yongyong Li; Huili Gong; Lin Zhu; Xiaojuan Li


    Beijing is located on multiple alluvial-pluvial fans with thick Quaternary unconsolidated sediments. It has suffered serious groundwater drawdown and land subsidence due to groundwater exploitation. This study aimed to introduce geographical distribution measure methods into land subsidence research characterizing, geographically, land subsidence, groundwater drawdown, and compressible layer thickness. Therefore, we used gravity center analysis and standard deviational ellipse (SDE) methods i...

  18. High levitation pressures with cage-cooled superconductors

    Energy Technology Data Exchange (ETDEWEB)

    Hull, John R. [Energy Technology Division, Argonne National Laboratory, Argonne, IL (United States); Komori, Mochimitsu [Department of Mechanical Systems Engineering, Kyushu Institute of Technology, Iizuka, Fukuoka (Japan)


    We present an analysis of and experimental results from a levitational system comprising a stationary, bulk high-temperature superconductor (HTS) and a levitated component (rotor) that consists of a cylindrical permanent magnet surrounded by an annular HTS. The rotor is cooled below the critical temperature of the HTS while surrounded by a ferromagnetic cage. When the ferromagnetic cage is removed, the flux from the permanent magnet is essentially excluded from the interior of the HTS. When brought into proximity with the HTS stator, the cage-cooled rotor experiences a levitational force. The levitational force may be calculated by applying magnetic circuit theory. Such calculations indicate that for a sufficiently high critical current density, the levitational pressure may exceed that between the permanent magnet and its mirror image. We constructed a rotor from an NdFeB permanent magnet and YBCO bulk HTS with a critical current density of {approx}5 kA cm{sup -2}. A soft ferromagnetic steel cage was constructed in segments. The critical current density of the stator HTS was also {approx}5 kA cm{sup -2}. Experimental results obtained with the cage-cooled rotor and stationary HTS show a significant increase in force over that of an equivalent PM rotor and stationary HTS. (author)


    Directory of Open Access Journals (Sweden)

    Merica Slišković


    Full Text Available Biofouling on fish–cage netting is a serious technical and economical problem to aquaculture worldwide. Compensation for the effects of biofouling must be included in cage system design and planning, as fouling can dramatically increase both weight and drag. Settlements of sessile plants and animals, with accumulation of the detritus diminish the size of mesh and can rapidly occlude mesh. Negative effect of smaller mesh size is changing in water flow trough the cages. Biofouling problems necessitating purchase of a second sets of nets or more, and frequent cleaning and changing of biofouling. Changing and cleaning frequency depend on many factors such as: location of cages (near the coast or off shore, productivity of that location, time of the year, time period in which the cages are placed on that location (cause of loading of phosphorus and nitrogen from the unconsumed food in the sediment. Net changing and cleaning procedures are labor and capital intensive. Process of the cleaning of the nets is inadequate, especially when there isnžt adequate equipment available as it is case in smaller aquaculture industry. Chemical control of biofouling e. g. use of antifoulants is questioningly cause of their possible negative effects on breeding species and environment.

  20. The Research on Subsidence Prediction of Soils Around Deep Foundation Pit

    Directory of Open Access Journals (Sweden)

    Ge LIU


    Full Text Available Deep foundation pit will cause settlement of surround buildings in the process of excavation. When the settlement is excessive, it will give rise to safety issues. Subsidence monitoring has become an important measure to ensure the safety of deep foundation pits. But in current subsidence monitoring engineering, the costs of wiring, unwiring and installation are particularly high. This paper proposes a portable wireless data transmission device in forecasting and early warning of settlement deformation of soils around deep foundation pits. We solve the problem by adopting the means of wireless communication to replace the cable transmission link part. The device does not rely on any personal computers. Instead, it can directly deal with the collected data through grey prediction GM (1, 1 mathematical model, neural network and interpolation model to give short-term, medium- term and long-term forecasts, respectively. Additionally it is able to set a threshold value. Once the forecast data reach the threshold, the device can issue alert and achieve the target of reminding technicians, so as to provide reliable basis to prevent and reduce disasters.

  1. The effect of manure and litter handling and climate conditions on ammonia emissions from a cage system and an aviary housing system for laying hens

    NARCIS (Netherlands)

    Groot Koerkamp, P.W.G.; Keen, A.; Niekerk, van T.; Smit, S.


    Ammonia emissions from both traditional and new welfare-based housing systems for laying hens must be reduced to prevent detrimental effects on the environment. In a comparative study, the effect of manure handling (variation in drying and removal frequency) in a battery cage and the effect of

  2. An optimized Faraday cage design for electron beam current measurements

    International Nuclear Information System (INIS)

    Turner, J.N.; Hausner, G.G.; Parsons, D.F.


    A Faraday cage detector is described for measuring electron beam intensity for use with energies up to 1.2 Mev, with the present data taken at 100 keV. The design features a readily changeable limiting aperture and detector cup geometry, and a secondary electron suppression grid. The detection efficiency of the cage is shown to be limited only by primary backscatter through the detector solid angle of escape, which is optimized with respect to primary backscattered electrons and secondary electron escape. The geometry and stopping material of the detection cup are varied, and the results show that for maximum detection efficiency with carbon as the stopping mateiral, the solid angle of escape must be equal to or less than 0.05πsr. The experimental results are consistent within the +-2% accuracy of the detection electronics, and are not limited by the Faraday cage detection efficiency. (author)

  3. (reprocessed)CAGE_peaks_annotation - FANTOM5 | LSDB Archive [Life Science Database Archive metadata

    Lifescience Database Archive (English)

    Full Text Available List Contact us FANTOM5 (reprocessed)CAGE_peaks_annotation Data detail Data name (reprocessed)CAGE_peaks_ann...rence sequences (hg38/mm10). Data file File name: (reprocessed)CAGE_peaks_annotation (Homo sapiens) File URL...: ...File size: 16 MB File name: (reprocessed)CAGE_peaks_annotation (Mus musculus) Fil...e URL:

  4. (reprocessed)CAGE peaks - FANTOM5 | LSDB Archive [Life Science Database Archive metadata

    Lifescience Database Archive (English)

    Full Text Available List Contact us FANTOM5 (reprocessed)CAGE peaks Data detail Data name (reprocessed)CAGE peaks DOI 10.18908/l...g38/mm10). Data file File name: (reprocessed)CAGE_peaks (Homo sapiens) File URL: File size: 11 MB File name: (reprocessed...)CAGE_peaks (Mus musculus) File URL: Database Site Policy | Contact Us (reprocessed)CAGE peaks - FANTOM5 | LSDB Archive ...

  5. (reprocessed)CAGE_peaks_expression - FANTOM5 | LSDB Archive [Life Science Database Archive metadata

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  6. Chaotic Dynamics of Cage Behavior in a High-Speed Cylindrical Roller Bearing

    Directory of Open Access Journals (Sweden)

    Long Chen


    Full Text Available This paper presents a mathematical model to investigate the nonlinear dynamic behavior of cage in high-speed cylindrical bearing. Variations of cage behavior due to varying cage eccentricity and cage guidance gap are observed. Hydrodynamic behavior in cage contacts is taken into consideration for a more realistic calculation of acting forces owing to high working speed. Analysis of real-time cage dynamic behavior on radial plane is carried out using chaos theory based on the theoretical and mathematical model established in the paper. The analytical results of this paper provide a solid foundation for designing and manufacturing of high-speed cylindrical roller bearing.

  7. Working to Reduce Poverty: A National Subsidized Employment Proposal

    Directory of Open Access Journals (Sweden)

    Indivar Dutta-Gupta


    Full Text Available Subsidized employment programs that increase labor supply and demand are a proven, underutilized strategy for reducing poverty in the short and long term. These programs use public and private funds to provide workers wage-paying jobs, training, and wraparound services to foster greater labor force attachment while offsetting employers’ cost for wages, on-the-job training, and overhead. This article proposes two new separate but harmonized federal funding streams for subsidized employment that would expand automatically when and where economic conditions deteriorate. Participating states and local organizations would be offered generous matching funds to target adult workers most in need and to secure employer participation. The proposal would effectively reduce poverty among workers during work placements, and improve long-term unsubsidized employment and other outcomes for participants and their families.

  8. Lifting and protecting residential structures from subsidence damage using airbags

    International Nuclear Information System (INIS)

    Triplett, T.L.; Bennett, R.M.


    Conventional practice in protecting residential structures from subsidence damage concentrates on saving the superstructure. The foundation is sacrificed, even though it represents the structural component with the greatest replacement cost. In this study, airbags were used to lift a 20 ft x 30 ft structure to test their ability to protect both the foundation and superstructure from ground settlement. Two contiguous sides of the test foundation were unreinforced, and the other two contiguous sides incorporated footing and wall reinforcement. The airbags successfully lifted the structure without causing damage, even on the unreinforced sides. This paper gives a procedure for determining airbag spacing, and describes installation and operation techniques of the airbags. The paper then focuses on the performance of the airbags in lifting the structure, and shows that airbags can preserve existing foundations during subsidence movements

  9. Mechanisms of subsidence for induced damage and techniques for analysis

    International Nuclear Information System (INIS)

    Drumm, E.C.; Bennett, R.M.; Kane, W.F.


    Structural damage due to mining induced subsidence is a function of the nature of the structure and its position on the subsidence profile. A point on the profile may be in the tensile zone, the compressive zone, or the no-deformation zone at the bottom of the profile. Damage to structures in the tension zone is primarily due to a reduction of support during vertical displacement of the ground surface, and to shear stresses between the soil and structure resulting from horizontal displacements. The damage mechanisms due to tension can be investigated effectively using a two-dimensional plane stress analysis. Structures in the compression zone are subjected to positive moments in the footing and large compressive horizontal stresses in the foundation walls. A plane strain analysis of the foundation wall is utilized to examine compression zone damage mechanisms. The structural aspects affecting each mechanism are identified and potential mitigation techniques are summarized

  10. Mining Land Subsidence Monitoring Using SENTINEL-1 SAR Data (United States)

    Yuan, W.; Wang, Q.; Fan, J.; Li, H.


    In this paper, DInSAR technique was used to monitor land subsidence in mining area. The study area was selected in the coal mine area located in Yuanbaoshan District, Chifeng City, and Sentinel-1 data were used to carry out DInSAR techniqu. We analyzed the interferometric results by Sentinel-1 data from December 2015 to May 2016. Through the comparison of the results of DInSAR technique and the location of the mine on the optical images, it is shown that DInSAR technique can be used to effectively monitor the land subsidence caused by underground mining, and it is an effective tool for law enforcement of over-mining.

  11. Subsidence resulting from multiple-seam longwall mining in the western United States

    International Nuclear Information System (INIS)

    Dyni, R.C.


    This paper details the investigation of multiple-seam longwall subsidence conducted by the U.S. Bureau of Mines from 1978 to 1989. A field investigation monitored ground surface movements over four upper seam longwall panels and six lower seam panels. The characteristics of the subsidence occurring as a result of mining these panels are examined: in particular, the angle of draw, subsidence development, total magnitude and areal extent, and critical width are evaluated and discussed. comparisons are also made between the characteristics of multiple-seam longwall subsidence and single-seam longwall subsidence that occurred at the same site

  12. Comparison of estimated and background subsidence rates in Texas-Louisiana geopressured geothermal areas

    Energy Technology Data Exchange (ETDEWEB)

    Lee, L.M.; Clayton, M.; Everingham, J.; Harding, R.C.; Massa, A.


    A comparison of background and potential geopressured geothermal development-related subsidence rates is given. Estimated potential geopressured-related rates at six prospects are presented. The effect of subsidence on the Texas-Louisiana Gulf Coast is examined including the various associated ground movements and the possible effects of these ground movements on surficial processes. The relationships between ecosystems and subsidence, including the capability of geologic and biologic systems to adapt to subsidence, are analyzed. The actual potential for environmental impact caused by potential geopressured-related subsidence at each of four prospects is addressed. (MHR)

  13. Problem definition study of subsidence caused by geopressured geothermal resource development

    Energy Technology Data Exchange (ETDEWEB)


    The environmental and socio-economic settings of four environmentally representative Gulf Coast geopressured geothermal fairways were inventoried. Subsidence predictions were prepared using feasible development scenarios for the four representative subsidence sites. Based on the results of the subsidence estimates, an assessment of the associated potential environmental and socioeconomic impacts was prepared. An inventory of mitigation measures was also compiled. Results of the subsidence estimates and impact assessments are presented, as well as conclusions as to what are the major uncertainties, problems, and issues concerning the future study of geopressured geothermal subsidence.

  14. Generalization of the influence function method in mining subsidence

    International Nuclear Information System (INIS)

    Bello Garcia, A.; Mendendez Diaz, A.; Ordieres Mere, J.B.; Gonzalez Nicieza, C.


    A generic approach to subsidence prediction based on the influence function method is presented. The changes proposed to the classical approach are the result of a previous analysis stage where a generalization to the 3D problem was made. In addition other hypothesis in order to relax the structural principles of the classical model are suggested. The quantitative results of this process and a brief discussion of its method of employment is presented. 13 refs., 8 figs., 5 tabs

  15. Observation of heights on the margin of subsidence depression

    Czech Academy of Sciences Publication Activity Database

    Bláha, P.; Doležalová, Hana; Müller, Karel; Skopal, R.


    Roč. 6, č. 2 (2006), s. 9-15 ISSN 1213-1962. [Nové poznatky a měření v seismologii, inženýrské geofyzice a geotechnice/15./. Ostrava, 11.04.2006-13.04.2006] Institutional research plan: CEZ:AV0Z30860518 Keywords : subsidence depression * levelling * fluctuation Subject RIV: DC - Siesmology, Volcanology, Earth Structure

  16. Employer Subsidized Meals and FAFH Consumption in Urban China


    Teng, Zhijing; Seale, James Jr.; Bai, Junfei; Wahl, Thomas I.


    This study investigates factors influencing household decisions on food away from home (FAFH) consumption with special interest given to the effects of employer subsidized meals on FAFH consumption. Using data from a new urban food consumption survey and collected by the Center for Chinese Agriculture Policy from 2009 to 2012 in 10 cities, a double-hurdle model is utilized to estimate the demand for FAFH as a whole and by type of facility (restaurant, fast-food outlet, and other facilities). ...

  17. Community-oriented administration of fluoride for the prevention of dental caries

    DEFF Research Database (Denmark)

    Petersen, P E; Baez, R J; Lennon, M A


    coverage. Participants acknowledged that automatic fluoridation through water, salt, and milk is the most effective and equitable strategy for the prevention of dental caries. Concerns were expressed that government-subsidized community fluoride prevention programs may face privatization. In addition...

  18. 14C-age tracers in global ocean circulation models (United States)

    Koeve, W.; Wagner, H.; Kähler, P.; Oschlies, A.


    The natural abundance of 14C in total CO2 dissolved in seawater is a property applied to evaluate the water age structure and circulation in the ocean and in ocean models. In this study we use three different representations of the global ocean circulation augmented with a suite of idealised tracers to study the potential and limitations of using natural 14C to determine water age, the time elapsed since a body of water had contact with the atmosphere. We find that, globally, bulk 14C-age is dominated by two equally important components, one associated with aging, i.e. the time component of circulation and one associated with a "preformed 14C-age". This latter quantity exists because of the slow and incomplete atmosphere/ocean equilibration of 14C in particular in high latitudes where many water masses form. The relative contribution of the preformed component to bulk 14C-age varies regionally within a given model, but also between models. Regional variability, e.g. in the Atlantic Ocean is associated with the mixing of waters with very different end members of preformed 14C-age. In the Atlantic, variations in the preformed component over space and time mask the circulation component to an extent that its patterns are not detectable from bulk 14C-age alone. Between models the variability of age can also be considerable (factor of 2), related to the combinations of physical model parameters, which influence circulation dynamics, and gas exchange in the models. The preformed component was found to be very sensitive to gas exchange and moderately sensitive to ice cover. In our model evaluation exercise, the choice of the gas exchange constant from within the current range of uncertainty had such a strong influence on preformed and bulk 14C-age that if model evaluation would be based on bulk 14C-age it could easily impair the evaluation and tuning of a models circulation on global and regional scales. Based on the results of this study, we propose that considering

  19. Historical Patterns in Ground Subsidence in Bucharest, Romania (United States)

    Armas, Iuliana; Necsoiu, Marius; Gherasim, Cezar


    Bucharest, the capital of Romania , is a city with a large number of buildings located in the alluvial Romanian plain, on the terraces and interfluves between two small rivers - Dambovita and Colentina. The goal of this research is to identify trends in land subsidence as a widespread form of mass movement in the city due to natural and anthropogenic factors. In this study we compared a digital surface model (DSM) based on ASTER Level 1A data with a digital elevation model (DEM) based on historical maps from 1900, to identify subsidence trends in the metropolitan area of Bucharest focusing on a few patterns within the historical center of the city. Accuracy of the DSM was tested by comparing it with accurate global positioning system (GPS) station locations acquired over the area. Noted changes in topography were correlated with the unique geomorphological features of the city focusing on regions that experienced large changes over time (i.e., developments over former marshes, clay pits, and landfill excavation areas between 1800 and 1950). Field investigations were performed on areas experiencing large elevation differences. The ongoing research will further explore recent ground deformation (subsidence) patterns identified via radar interferometry (InSAR) correlate with declining groundwater levels (due to groundwater extraction) and construction.

  20. Sources of subsidence at the Salton Sea Geothermal Field (United States)

    Barbour, Andrew J.; Evans, Eileen; Hickman, Stephen H.; Eneva, Mariana


    At the Salton Sea Geothermal Field (SSGF) in Southern California, surface deformation associated with geologic processes including sediment compaction, tectonic strain, and fault slip may be augmented by energy production activities. Separating the relative contributions from natural and anthropogenic sources is especially important at the SSGF, which sits at the apex of a complex tectonic transition zone connecting the southern San Andreas Fault with the Imperial Fault; but this has been a challenging task so far. Here we analyze vertical surface velocities obtained from the persistent scatterer InSAR method and find that two of the largest subsidence anomalies can be represented by a set of volumetric strain nuclei at depths comparable to geothermal well completion zones. In contrast, the rates needed to achieve an adequate fit to the magnitudes of subsidence are almost an order of magnitude greater than rates reported for annual changes in aggregate net-production volume, suggesting that the physical mechanism responsible for subsidence at the SSGF is a complicated interplay between natural and anthropogenic sources.

  1. Quaternary subsidence of the Oahu Coastal Plain, Hawaiian Islands (United States)

    Toomey, M.; Sandstrom, R. M.; Huppert, K.; Taylor, F. W.; Cronin, T. M.


    Inter-plate hotspots continue to test our understanding of how the Earth's lithosphere deforms in response to an applied load, in part, because many current models are based on short or discontinuous observational datasets. Here we reconstruct a record of relative sea level rise spanning nearly two million years using the strontium isotope stratigraphy (SIS) of shallow water carbonates (e.g. corals, mollusks) recovered from a >300 m long drill core through the coastal plain of Oahu. We then compare it to model-predicted subsidence histories for our site that incorporate displacements at Ewa Beach, Oahu, due to the flexural isostatic response of the lithosphere to loading of each volcano along the Hawaiian Ridge as well as its migration over the Hawaiian Swell. Preliminary results indicate Oahu experienced relatively rapid rates of subsidence ( 0.45 mm/yr) during the mid-Pleistocene—vertical displacements our model largely attributes to loading of West Molokai. An abrupt slowing of subsidence over the past million years may be driven by the relative eastward progression of volcanism, including construction of large shields on Maui and Hawaii. Shallowly buried, late Pleistocene aged corals, however, may suggest: (1) a more limited flexural response to this loading for southeastern Oahu than has been inferred from raised marine isotope stage (MIS) 11/13 dated, shallow-water, deposits found elsewhere on the island and/or (2) substantial dissolution of coastal plain carbonates between MIS 31 and 11.

  2. Modeling of flexible reciprocating compressor considering the crosshead subsidence (United States)

    Xue, Xiaogang; Liu, Shulin; Sun, Xin


    Crank-slider mechanisms are important parts of heavy duty machines, including reciprocating compressors, combustion motors. This paper targets on the dynamic response of the crosshead in a reciprocating compressor, taking into consideration the crosshead deviation from the original level. The traditional model of the compressor is usually a slider-mechanism system without considering the deflection of the crosshead, thus neglecting the influence of the piston rod, which has some flexible features. In this paper, a rigid-flexible model of slider-crank is described theoretically, using the commercial software MATLAB, where the crank, connecting rod and crosshead are treated as rigid bodies, while the piston rod connected to the crosshead is considered as a flexible body. The dynamic response of the mechanism with the crosshead subsidence is discussed detailedly in this paper. After calculated theoretically, the MATLAB simulation showed that the dynamic response of the crosshead will be greatly influenced if the crosshead subsided from the original level. Also, the influence of the crosshead subsidence was also investigated, and some extra vibration of the crosshead arises.

  3. Subsidence above in situ vitrification: Evaluation for Hanford applications

    International Nuclear Information System (INIS)

    Dershowitz, W.S.; Plum, R.L.; Luey, J.


    Pacific Northwest Laboratory (PNL)is evaluating methods to extend the applicability of the in situ vitrification (ISV) process. One method being evaluated is the initiation of the ISV process in the soil subsurface rather than the traditional start from the surface. The subsurface initiation approach will permit extension of the ISV treatment depth beyond that currently demonstrated and allow selective treatment of contamination in a geologic formation. A potential issue associated with the initiation of the ISV process in the soil subsurface is the degree of subsidence and its effect on the ISV process. The reduction in soil porosity caused by the vitrification process will result in a volume decrease for the vitrified soils. Typical volume reduction observed for ISV melts initiated at the surface are on the order of 20% to 30% of the melt thickness. Movement of in-situ materials into the void space created during an ISV application in the soil subsurface could result in surface settlements that affect the ISV process and the processing equipment. Golder Associates, Inc., of Redmond, Washington investigated the potential for subsidence events during application of ISV in the soil subsurface. Prediction of soil subsidence above an ISV melt required the following analyses: the effect of porosity reduction during ISV, failure of fused materials surrounding the ISV melt, bulking of disturbed materials above the melt, and propagation of strains to the surface

  4. Subsidence Rates of Drained Agricultural Peatlands in New Zealand and the Relationship with Time since Drainage. (United States)

    Pronger, Jack; Schipper, Louis A; Hill, Reece B; Campbell, David I; McLeod, Malcolm


    The drainage and conversion of peatlands to productive agro-ecosystems leads to ongoing surface subsidence because of densification (shrinkage and consolidation) and oxidation of the peat substrate. Knowing the ra0te of this surface subsidence is important for future land-use planning, carbon accounting, and economic analysis of drainage and pumping costs. We measured subsidence rates over the past decade at 119 sites across three large, agriculturally managed peatlands in the Waikato region, New Zealand. The average contemporary (2000s-2012) subsidence rate for Waikato peatlands was 19 ± 2 mm yr (± SE) and was significantly less ( = 0.01) than the historic rate of 26 ± 1 mm yr between the 1920s and 2000s. A reduction in the rate of subsidence through time was attributed to the transition from rapid initial consolidation and shrinkage to slower, long-term, ongoing oxidation. These subsidence rates agree well with a literature synthesis of temperate zone subsidence rates reported for similar lengths of time since drainage. A strong nonlinear relationship was found between temperate zone subsidence rates and time since initial peatland drainage: Subsidence (mm yr) = 226 × (years since drained) ( = 0.88). This relationship suggests that time since drainage exerts strong control over the rate of peatland subsidence and that ongoing peatland subsidence rates can be predicted to gradually decline with time in the absence of major land disturbance. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

  5. Subsidence in tropical peatlands: Estimating CO2 fluxes from peatlands in Southeast Asia (United States)

    Hoyt, A.; Harvey, C. F.; Seppalainen, S. S.; Chaussard, E.


    Tropical peatlands of Southeast Asia are an important global carbon stock. However, they are being rapidly deforested and drained. Peatland drainage facilitates peat decomposition, releases sequestered peat carbon to the atmosphere as CO2, and leads to subsidence of the peat surface. As a result, subsidence measurements can be used to monitor peatland carbon loss over time. Until now, subsidence measurements have been primarily limited to ground-based point measurements using subsidence poles. Here we demonstrate a powerful method to measure peatland subsidence rates across much larger areas than ever before. Using remotely sensed InSAR data, we map subsidence rates across thousands of square kilometers in Southeast Asia and validate our results against ground-based subsidence measurements. The method allows us to monitor subsidence in remote locations, providing unprecedented spatial information, and the first comprehensive survey of land uses such as degraded peatlands, burnt and open areas, shrub lands, and smallholder farmlands. Strong spatial patterns emerged, with the highest subsidence rates occurring at the centers of peat domes, where the peat is thickest and drainage depths are likely to be largest. Peatland subsidence rates were also strongly dependent on current and historical land use, with typical subsidence rates ranging from 2-4 cm/yr. Finally, we scaled up our results to calculate total annual emissions from peat decomposition in degraded peatlands.

  6. Advancing Coastal Climate Adaptation in Denmark by Land Subsidence Mapping using Sentinel-1 Satellite Imagery

    DEFF Research Database (Denmark)

    Sørensen, Carlo Sass; Broge, Niels H.; Mølgaard, Mads R.


    There are still large uncertainties in projections of climate change and sea level rise. Here, land subsidence is an additional factor that may adversely affect the vulnerability towards floods in low-lying coastal communities. The presented study performs an initial assessment of subsidence...... mapping using Sentinel-1 satellite imagery and leveling at two coastal locations in Denmark. Within both investigated areas current subsidence rates of 5-10 millimeters per year are found. This subsidence is related to the local geology, and challenges and potentials in bringing land subsidence mapping...... and geology into climate adaptation are discussed in relation to perspectives of a national subsidence monitoring system partly based on the findings from the two coastal locations. The current lack of subsidence data and a fragmentation of geotechnical information are considered as hindrances to optimal...

  7. Risk Factors for Subsidence of a Modular Tapered Femoral Stem Used for Revision Total Hip Arthroplasty. (United States)

    Tangsataporn, Suksan; Safir, Oleg A; Vincent, Alexander D; Abdelbary, Hesham; Gross, Allan E; Kuzyk, Paul R T


    The purpose of this study was to determine the incidence, and the clinical and radiographic risk factors for significant subsidence of a cementless, modular tapered revision femoral stem. Femoral stem subsidence of at least 10 mm or subsidence requiring revision was considered significant subsidence. Ninety-seven patients (99 hips) were included with minimum radiographic follow-up of one year (mean 34 months; range, 12-91 months). The mean stem subsidence was 4.5 mm (range, 0-44 mm). Fourteen out of 99 (14.1%) stems had significant subsidence and 6 (6.1%) stems required revision due to subsidence. Patient weight greater than 80 kg (P=0.04) and femoral stem press-fit distance of less than 2 cm (Psubsidence. Copyright © 2015 Elsevier Inc. All rights reserved.

  8. Characterization of land subsidence induced by groundwater withdrawals in Wenyu River alluvial fan, Beijing, China

    Directory of Open Access Journals (Sweden)

    R. Wang


    Full Text Available The Beijing plain area has suffered from severe land subsidence owing to groundwater overdraft. A major example is the Wenyu River alluvial fan in the Beijing plain area. This area has experienced as much as 10 m of land subsidence through 2000s. An integrated subsidence-monitoring program, including borehole extensometer and multilayer monitoring of groundwater, has been designed to meet the needs of monitoring land subsidence in this region. This work has allowed us to characterize land subsidence and understand the mechanical properties of the strata. The analysis results show the development of the land subsidence in this area is consistent with water-level change. The major strata contributing to compression deformation are Mid-Pleistocene stratum which contributed around 70 % of total subsidence. The shallow stratum and deep stratum show elastic mechanical behavior the intermediate stratum exhibit elastic-plastic mechanical behavior.

  9. Role of Rock Mass Fabric and Faulting in the Development of Block Caving Induced Surface Subsidence (United States)

    Vyazmensky, Alexander; Elmo, Davide; Stead, Douglas


    Extraction of a large volume of ore during block caving can lead to the formation of significant surface subsidence. Current knowledge of the mechanisms that control subsidence development is limited as are our subsidence prediction capabilities. Mining experience suggests that, among other contributing factors, geological structures play a particularly important role in subsidence development. A conceptual modeling study has been undertaken to evaluate the significance of geological structure on surface subsidence. A hybrid finite/discrete element technique incorporating a coupled elasto-plastic fracture mechanics constitutive criterion is adopted; this allows physically realistic modeling of block caving through simulation of the transition from a continuum to a discontinuum. Numerical experiments presented emphasize the importance of joint orientation and fault location on mechanisms of subsidence development and the governing role of geological structure in defining the degree of surface subsidence asymmetry.

  10. Global sea-level rise is recognised, but flooding from anthropogenic land subsidence is ignored around northern Manila Bay, Philippines. (United States)

    Rodolfo, Kelvin S; Siringan, Fernando P


    Land subsidence resulting from excessive extraction of groundwater is particularly acute in East Asian countries. Some Philippine government sectors have begun to recognise that the sea-level rise of one to three millimetres per year due to global warming is a cause of worsening floods around Manila Bay, but are oblivious to, or ignore, the principal reason: excessive groundwater extraction is lowering the land surface by several centimetres to more than a decimetre per year. Such ignorance allows the government to treat flooding as a lesser problem that can be mitigated through large infrastructural projects that are both ineffective and vulnerable to corruption. Money would be better spent on preventing the subsidence by reducing groundwater pumping and moderating population growth and land use, but these approaches are politically and psychologically unacceptable. Even if groundwater use is greatly reduced and enlightened land-use practices are initiated, natural deltaic subsidence and global sea-level rise will continue to aggravate flooding, although at substantially lower rates.

  11. (reprocessed)HeliscopeCAGE sequencing, Delve mapping and CAGE TSS aggregation - FANTOM5 | LSDB Archive [Life Science Database Archive metadata

    Lifescience Database Archive (English)

    Full Text Available List Contact us FANTOM5 (reprocessed)HeliscopeCAGE sequencing, Delve mapping and CAGE TSS aggregation Data detail Data name ( File size: 237 KB File name: (reprocessed)basic (Homo sapiens) File URL: File size: 1.4 TB File name: (reprocess...ed)basic (Mus musculus) File URL: format) About This Database Database Description Download License Update History of This Database Site Policy | Contact Us (reproce

  12. Impacts of cage culture on physico-chemical and bacteriological ...

    African Journals Online (AJOL)

    The effects of cage fish farming on physico-chemical and bacteriological water quality in Lake Volta, Ghana, were investigated in 2013–2014. Farmed ... The bacteriological analysis, however, revealed contamination of the lake water by fish farming. ... Keywords: aquaculture, contamination, fish farming, large lake, pollution ...

  13. Diet manipulation and post-moulting responses in caged ...

    African Journals Online (AJOL)

    Two hundred and fifty caged commercial laying hens were induced to moult through a 15-day feed and water withdrawal programme. Immediate and subsequent effects on egg production and follicular developments were monitored. Results showed that moulted hens attained over 60% egg production after 6 weeks of ...

  14. Clathrates - An Exploration of the Chemistry of Caged Compounds

    Indian Academy of Sciences (India)

    The hollow cage structure are made up of hexagonal and pentagonal homo- atomic shells of carbon. Twenty hexagons and twelve isolated pentagons interact to .... The guests are generally alkali and alkaline-earth atoms. The cavity size of Si and Ge are compa- rable only with those ofNa+ ofK+ and compounds like KgGe.

  15. Regioselective nitration of aromatic substrates in zeolite cages

    Indian Academy of Sciences (India)

    Phenol is nitrated regioselectively by fuming nitric acid inside the cages of faujasite zeolites (dependent on the loading level) and a remarkable orthoselectivity is observed in solid state nitration. Toluene and chlorobenzene also containing ortho-/para-orienting substituents, undergo faster nitration, though the ...

  16. power generation and control of a self excited squirrel cage ...

    African Journals Online (AJOL)


    powering customers isolated from the utility grid by wind energy because it derives its excitation from its own output terminal and neither an ... mechanically to the rotor of a squirrel cage induction which is fed with grid powerthat the generator supplies. A back ... than a conventional synchronous generator in micro- hydro and ...

  17. Power generation and control of a self excited squirrel cage ...

    African Journals Online (AJOL)

    The self-excited squirrel cage induction generator (SEIG) is frequently considered as the most economical solution for powering customers isolated from the utility grid by wind energy because it derives its excitation from its own output terminal and neither an exciter nor voltage regulator is required. Its major drawbacks ...

  18. Fish cage culture catches on in Nepal | IDRC - International ...

    International Development Research Centre (IDRC) Digital Library (Canada)


    Oct 25, 2010 ... Fish Cage Culture in Nepal: from Displacement to Development An audio slideshow. Success Stories in Asian Aquaculture The stories presented in this book reflect the unique nature of Asian aquaculture, providing first-time insight into how and why it has become so successful. Utilizing Different Aquatic ...

  19. utilization of ensiled metabolizable mixture of cassava peel and caged

    African Journals Online (AJOL)



    Sep 5, 2011 ... component of farm animal feed has been documented [8, 9]. Therefore, this investigation was carried out to study the response of broiler chicken to fermented mixture of cassava peel and caged layers' manure (obtained as farm residue or waste) and fed as a component of energy source in the feed.

  20. variations in dimensions and shape of thoracic cage with aging

    African Journals Online (AJOL)

    ABSTRACT. The thoracic cage variations in dimensions and proportions are influenced by age, sex and race. The objective of the present review was to describe the age related changes occurring in thoracic wall and its influence on the pattern of respiration in infants, adult and elderly. We had systematically reviewed, ...

  1. Clathrates-An Exploration of the Chemistry of Caged Compounds

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 9; Issue 7. Clathrates – An Exploration of the Chemistry of Caged Compounds. Srivathsa Vaidya. General Article ... Author Affiliations. Srivathsa Vaidya1. 64400 Freret Street Department of Chemistry Tulane University New Orleans, LA 70118 USA ...

  2. Rotational dynamics of propylene inside Na-Y zeolite cages

    Indian Academy of Sciences (India)

    molecules etc. Several such dependences have been under investigation [2]. We have in particular been investigating the diffusivities of hydrocarbons in Na-Y ze- olitic cages. In this context we had earlier reported the translational diffusivities of propane, acetylene and 1,3-butadiene in Na-Y zeolite [3–5]. The translational.

  3. FANTOM5 CAGE profiles of human and mouse samples

    NARCIS (Netherlands)

    Noguchi, Shuhei; Arakawa, Takahiro; Fukuda, Shiro; Furuno, Masaaki; Hasegawa, Akira; Hori, Fumi; Ishikawa-Kato, Sachi; Kaida, Kaoru; Kaiho, Ai; Kanamori-Katayama, Mutsumi; Kawashima, Tsugumi; Kojima, Miki; Kubosaki, Atsutaka; Manabe, Ri-ichiroh; Murata, Mitsuyoshi; Nagao-Sato, Sayaka; Nakazato, Kenichi; Ninomiya, Noriko; Nishiyori-Sueki, Hiromi; Noma, Shohei; Saijyo, Eri; Saka, Akiko; Sakai, Mizuho; Simon, Christophe; Suzuki, Naoko; Tagami, Michihira; Watanabe, Shoko; Yoshida, Shigehiro; Arner, Peter; Axton, Richard A; Babina, Magda; Baillie, J Kenneth; Barnett, Timothy C; Beckhouse, Anthony G; Blumenthal, Antje; Bodega, Beatrice; Bonetti, Alessandro; Briggs, James; Brombacher, Frank; Carlisle, Ailsa J; Clevers, Hans C; Davis, Carrie A; Detmar, Michael; Dohi, Taeko; Edge, Albert S B; Edinger, Matthias; Ehrlund, Anna; Ekwall, Karl; Endoh, Mitsuhiro; Enomoto, Hideki; Eslami, Afsaneh; Fagiolini, Michela; Fairbairn, Lynsey; Farach-Carson, Mary C; Faulkner, Geoffrey J; Ferrai, Carmelo; Fisher, Malcolm E; Forrester, Lesley M; Fujita, Rie; Furusawa, Jun-ichi; Geijtenbeek, Teunis B; Gingeras, Thomas; Goldowitz, Daniel; Guhl, Sven; Guler, Reto; Gustincich, Stefano; Ha, Thomas J; Hamaguchi, Masahide; Hara, Mitsuko; Hasegawa, Yuki; Herlyn, Meenhard; Heutink, Peter; Hitchens, Kelly J; Hume, David A; Ikawa, Tomokatsu; Ishizu, Yuri; Kai, Chieko; Kawamoto, Hiroshi; Kawamura, Yuki I; Kempfle, Judith S; Kenna, Tony J; Kere, Juha; Khachigian, Levon M; Kitamura, Toshio; Klein, Sarah; Klinken, S Peter; Knox, Alan J; Kojima, Soichi; Koseki, Haruhiko; Koyasu, Shigeo; Lee, Weonju; Lennartsson, Andreas; Mackay-Sim, Alan; Mejhert, Niklas; Mizuno, Yosuke; Morikawa, Hiromasa; Morimoto, Mitsuru; Moro, Kazuyo; Morris, Kelly J; Motohashi, Hozumi; Mummery, Christine L; Nakachi, Yutaka; Nakahara, Fumio; Nakamura, Toshiyuki; Nakamura, Yukio; Nozaki, Tadasuke; Ogishima, Soichi; Ohkura, Naganari; Ohno, Hiroshi; Ohshima, Mitsuhiro; Okada-Hatakeyama, Mariko; Okazaki, Yasushi; Orlando, Valerio; Ovchinnikov, Dmitry A; Passier, Robert; Patrikakis, Margaret; Pombo, Ana; Pradhan-Bhatt, Swati; Qin, Xian-Yang; Rehli, Michael; Rizzu, Patrizia; Roy, Sugata; Sajantila, Antti; Sakaguchi, Shimon; Sato, Hiroki; Satoh, Hironori; Savvi, Suzana; Saxena, Alka; Schmidl, Christian; Schneider, Claudio; Schulze-Tanzil, Gundula G; Schwegmann, Anita; Sheng, Guojun; Shin, Jay W; Sugiyama, Daisuke; Sugiyama, Takaaki; Summers, Kim M; Takahashi, Naoko; Takai, Jun; Tanaka, Hiroshi; Tatsukawa, Hideki; Tomoiu, Andru; Toyoda, Hiroo; van de Wetering, Marc; van den Berg, Linda M; Verardo, Roberto; Vijayan, Dipti; Wells, Christine A; Winteringham, Louise N; Wolvetang, Ernst; Yamaguchi, Yoko; Yamamoto, Masayuki; Yanagi-Mizuochi, Chiyo; Yoneda, Misako; Yonekura, Yohei; Zhang, Peter G; Zucchelli, Silvia; Abugessaisa, Imad; Arner, Erik; Harshbarger, Jayson; Kondo, Atsushi; Lassmann, Timo; Lizio, Marina; Sahin, Serkan; Sengstag, Thierry; Severin, Jessica; Shimoji, Hisashi; Suzuki, Masanori; Suzuki, Harukazu; Kawai, Jun; Kondo, Naoto; Itoh, Masayoshi; Daub, Carsten O; Kasukawa, Takeya; Kawaji, Hideya; Carninci, Piero; Forrest, Alistair R R; Hayashizaki, Yoshihide


    In the FANTOM5 project, transcription initiation events across the human and mouse genomes were mapped at a single base-pair resolution and their frequencies were monitored by CAGE (Cap Analysis of Gene Expression) coupled with single-molecule sequencing. Approximately three thousands of samples,

  4. Caged ceramide 1-phosphate analogues: synthesis and properties. (United States)

    Lankalapalli, Ravi S; Ouro, Alberto; Arana, Lide; Gómez-Muñoz, Antonio; Bittman, Robert


    Sphingolipid phosphate analogues bearing 7-(diethylamino)coumarin (DECM) and 4-bromo-5-hydroxy-2-nitrobenzhydryl (BHNB) groups in a photolabile ester bond were synthesized. The ability of the "caged" ceramide 1-phosphate analogues to release the bioactive parent molecule upon irradiation at 400-500 nm was demonstrated by stimulation of macrophage cell proliferation.

  5. Thoracic cage injury imaging in rugby players | de Villiers | SA ...

    African Journals Online (AJOL)

    Rugby players often sustain high-impact collisions and are therefore at risk of significant traumatic thoracic injuries. Injury to the thoracic cage may be associated with potentially life-threatening sequelae. Player management is often based on the accuracy of the imaging report. The author suggests a combination of ...

  6. Business plan Tilapia cage farming in Tete Zambezi Valley, Mozambique

    NARCIS (Netherlands)

    Meer, van der Magnus; Brouwer, Herman


    Tete province offers great opportunities for cage farming of tilapia in Lake Cahora Bassa. The climate and water quality are favourable for fish production, and the fast economic developments in the region will facilitate fish sales. In Tete tilapia (pende) is highly valued food. Major markets for

  7. Cages Based on the Carbon-Carbon Composites

    Czech Academy of Sciences Publication Activity Database

    Sochor, M.; Balík, Karel; Tichý, P.; Vtípil, J.; Suchý, Tomáš; Sedláček, R.; Kolář, František; Černý, Martin; Beneš, J.; Hulejová, H.; Pešáková, V.

    12(132) (2003), s. 49-57 ISSN 1212-1576 R&D Projects: GA ČR GA106/00/1407 Institutional research plan: CEZ:AV0Z3046908 Keywords : carbon-carbon composites * cage * spine treatment Subject RIV: JH - Ceramics, Fire-Resistant Materials and Glass


    Effects of caging density on pituitary and testicle related responses A significant negative correlation between the incidence of testicular interstitial cell tumors (ICT) and of pituitary tumors (PT) in control male F344 rats is reported associated with the number of ani...

  9. Microbial control of caged population of Zonocerus variegatus using ...

    African Journals Online (AJOL)

    Microbial control of caged populations of Zonocerus variegatus was carried out using indigenous fungal entomopathogens isolated from the grasshopper's cadaver. Bioassay response indicated a dose-dependent mortality coupled with drastic reduction in food consumption among spores infected grasshoppers. Lethal time ...

  10. FANTOM5 CAGE profiles of human and mouse samples

    KAUST Repository

    Noguchi, Shuhei


    In the FANTOM5 project, transcription initiation events across the human and mouse genomes were mapped at a single base-pair resolution and their frequencies were monitored by CAGE (Cap Analysis of Gene Expression) coupled with single-molecule sequencing. Approximately three thousands of samples, consisting of a variety of primary cells, tissues, cell lines, and time series samples during cell activation and development, were subjected to a uniform pipeline of CAGE data production. The analysis pipeline started by measuring RNA extracts to assess their quality, and continued to CAGE library production by using a robotic or a manual workflow, single molecule sequencing, and computational processing to generate frequencies of transcription initiation. Resulting data represents the consequence of transcriptional regulation in each analyzed state of mammalian cells. Non-overlapping peaks over the CAGE profiles, approximately 200,000 and 150,000 peaks for the human and mouse genomes, were identified and annotated to provide precise location of known promoters as well as novel ones, and to quantify their activities.

  11. Mooring Design Selection of Aquaculture Cage for Indonesian Ocean (United States)

    Mulyadi, Y.; Syahroni, N.; Sambodho, K.; Zikra, M.; Wahyudi; Adia, H. B. P.


    Fish production is important for the economy in fishing community and for ensuring food security. Climate change will lead a threat to fish productivity. Therefore, a solution offered is to cultivate certain fish, especially those with high economic value by using offshore aquaculture technology. A Sea Station cage is one of the offshore aquaculture cage model that has been used in some locations. As a floating structure, the Sea Station cage need a mooring system to maintain its position. This paper presents the selection analysis of the mooring system designs of the Sea Station cage model that it is suitable with Indonesia Ocean. There are 3 mooring configurations that are linear array, rectangular array, and 4 points mooring type. The nylon mooring rope type has been selected to be used on the 3 mooring configurations and the rope has a diameter of 104 mm with a breaking force of 2.3 MN. Based on results from comparing the 3 mooring configurations, the best mooring configuration is linear array with the tension on the rope of 217 KN and has the safety factor of 0.2 based on DNVGL OS-E301

  12. power generation and control of a self excited squirrel cage

    African Journals Online (AJOL)


    The self-excited squirrel cage induction generator (SEIG) is frequently considered as the most economical solution for powering customers isolated from the utility grid by wind energy because it derives its excitation from its own output terminal and neither an exciter nor voltage regulator is required. Its major drawbacks ...

  13. Assessment of the Usability of the Workbench Faraday Cage Method

    DEFF Research Database (Denmark)

    Sørensen, Morten; Franek, Ondrej; Christensen, Søren K.


    The workbench Faraday Cage method (WBFC) is a time efficient module pre-compliance test regarding radiated emission. This work investigates the method’s usability and credibility and concludes that for this particular case the WBFC perform a tolerable compliance test for frequencies below 360 MHz...

  14. Complex susceptibility of the cage model of polar liquids

    CERN Document Server

    Coffey, W T; Kalmykov, Yu P; Titov, S V


    The Langevin equations of motion of the cage model of polar liquids originally proposed by Hill (1963 Proc. Phys. Soc. 82 723) are solved for the first time for the particular case of rotation about a fixed axis, using a newly developed matrix continued fraction method. It is shown that the cage model predicts both the low-frequency Debye relaxation and a pronounced high-frequency (Poley) absorption peak in the far-infrared (FIR) region. The similarity of the equations of motion of the cage model to the equations which arise in the problem of generalizing the Onsager model of polar fluids to include a time-varying applied field suggests that the FIR (Poley) absorption may have its origins in the combined influence of molecular inertia and the torque due to the reaction field in the frequency-dependent version of the Onsager model. The complex susceptibility yielded by the cage model is shown to be in good agreement with experimental data on CH sub 3 Cl that were taken as a typical example. Moreover, a simple ...

  15. Mice Do Not Habituate to Metabolism Cage Housing

    DEFF Research Database (Denmark)

    Kalliokoski, Otto; Jacobsen, Kirsten Rosenmaj; Darusman, Huda Shalahudin


    The metabolism cage is a barren, non-enriched, environment, combining a number of recognized environmental stressors. We investigated the ability of male BALB/c mice to acclimatize to this form of housing. For three weeks markers of acute and oxidative stress, as well as clinical signs of abnorma...

  16. Social communication in mice--are there optimal cage conditions?

    Directory of Open Access Journals (Sweden)

    Allain-Thibeault Ferhat

    Full Text Available Social communication is heavily affected in patients with neuropsychiatric disorders. Accordingly, mouse models designed to study the mechanisms leading to these disorders are tested for this phenotypic trait. Test conditions vary between different models, and the effect of these test conditions on the quantity and quality of social interactions and ultrasonic communication is unknown. The present study examines to which extent the habituation time to the test cage as well as the shape/size of the cage influence social communication in freely interacting mice. We tested 8 pairs of male mice in free dyadic social interactions, with two habituation times (20 min and 30 min and three cage formats (rectangle, round, square. We tested the effect of these conditions on the different types of social contacts, approach-escape sequences, follow behavior, and the time each animal spent in the vision field of the other one, as well as on the emission of ultrasonic vocalizations and their contexts of emission. We provide for the first time an integrated analysis of the social interaction behavior and ultrasonic vocalizations. Surprisingly, we did not highlight any significant effect of habituation time and cage shape/size on the behavioral events examined. There was only a slight increase of social interactions with the longer habituation time in the round cage. Remarkably, we also showed that vocalizations were emitted during specific behavioral sequences especially during close contact or approach behaviors. The present study provides a protocol reliably eliciting social contacts and ultrasonic vocalizations in adult male mice. This protocol is therefore well adapted for standardized investigation of social interactions in mouse models of neuropsychiatric disorders.

  17. 48 CFR 252.204-7001 - Commercial and Government Entity (CAGE) code reporting. (United States)


    ... Entity (CAGE) code reporting. 252.204-7001 Section 252.204-7001 Federal Acquisition Regulations System... Entity (CAGE) Code Reporting (AUG 1999) (a) The offeror is requested to enter its CAGE code on its offer... AND CONTRACT CLAUSES Text of Provisions And Clauses 252.204-7001 Commercial and Government Entity...

  18. 30 CFR 75.1403-3 - Criteria-Drum clutch; cage construction. (United States)


    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Criteria-Drum clutch; cage construction. 75... § 75.1403-3 Criteria—Drum clutch; cage construction. (a) The clutch of a free-drum on a personnel hoist... withdrawal of the clutch. (b) Cages used for hoisting persons should be constructed with the sides enclosed...

  19. Distribution Characteristic and Migration Pathways of Metals in Subsidence Zone in a Coal Mine, China. (United States)

    Han, Fushun; Zhang, Yan


    Subsidence can influence the distribution characteristics and migration pathways of metals in coal mines. In order to understand the two important and related issues of subsidence and pollution in coal mines, ten sample cores were collected in the coal mining subsidence and non-subsidence zones in Anhui province, China, and the concentration and forms of metals were analyzed. The results showed that concentrations for all metals significantly increased at the depth of 0-20 cm in these two zones. Concentrations of Cd, Cu, and Zn in the non-subsidence zone were 1.14, 1.69 and 1.48 times higher, respectively, than those in the subsidence zone, while concentrations of Cr and Pb showed no significant difference. The proportion of exchangeable and acid-extracted fractions of Cd, Cu and Zn in the non-subsidence zone were higher than those in the subsidence zone. This may be due to the different migration pathways for exchangeable and acid-extracted fractions of metals in subsidence and non-subsidence zones.

  20. Lithosphere structure and subsidence evolution of the conjugate S-African and Argentine margins (United States)

    Dressel, Ingo; Scheck-Wenderoth, Magdalena; Cacace, Mauro; Götze, Hans-Jürgen; Franke, Dieter


    The bathymetric evolution of the South Atlantic passive continental margins is a matter of debate. Though it is commonly accepted that passive margins experience thermal subsidence as a result of lithospheric cooling as well as load induced subsidence in response to sediment deposition it is disputed if the South Atlantic passive margins were affected by additional processes affecting the subsidence history after continental breakup. We present a subsidence analysis along the SW African margin and offshore Argentina and restore paleobathymetries to assess the subsidence evolution of the margin. These results are discussed with respect to mechanisms behind margin evolution. Therefore, we use available information about the lithosphere-scale present-day structural configuration of these margins as a starting point for the subsidence analysis. A multi 1D backward modelling method is applied to separate individual subsidence components such as the thermal- as well as the load induced subsidence and to restore paleobathymetries for the conjugate margins. The comparison of the restored paleobathymetries shows that the conjugate margins evolve differently: Continuous subsidence is obtained offshore Argentina whereas the subsidence history of the SW African margin is interrupted by phases of uplift. This differing results for both margins correlate also with different structural configurations of the subcrustal mantle. In the light of these results we discuss possible implications for uplift mechanisms.

  1. Spatial-temporal variation of groundwater and land subsidence evolution in Beijing area

    Directory of Open Access Journals (Sweden)

    K. Lei


    Full Text Available Precipitation is the main recharge source of groundwater in the plain of Beijing, China. Rapid expansion of urbanization has resulted in increased built-up area and decreased amount of effective recharge of precipitation to groundwater, indirectly leading to the long-term over-exploitation of groundwater, and induced regional land subsidence. Based on the combination of meteorological data, groundwater level data, interferometric synthetic aperture radar (InSAR; specifically persistent scatterer interferometry, PSI, geographic information system (GIS spatial analysis method and rainfall recharge theory, this paper presents a systematic analysis of spatial-temporal variation of groundwater level and land subsidence evolution. Results show that rainfall has been decreasing annually, while the exploitation of groundwater is increasing and the groundwater level is declining, which is has caused the formation and evolution of land subsidence. Seasonal and interannual variations exist in the evolution of land subsidence; the subsidence is uneven in both spatial and temporal distribution. In 2011, at the center of mapped subsidence the subsidence rate was greater than 120 mm a−1. The results revealed good correlation between the spatial distribution of groundwater level declines and subsidence. The research results show that it is beneficial to measure the evolution of land subsidence to dynamic variations of groundwater levels by combining InSAR or PSI, groundwater-level data, and GIS. This apprpach provides improved information for environmental and hydrogeologic research and a scientific basis for regional land subsidence control.

  2. Measuring Spatiotemporal Features of Land Subsidence, Groundwater Drawdown, and Compressible Layer Thickness in Beijing Plain, China

    Directory of Open Access Journals (Sweden)

    Yongyong Li


    Full Text Available Beijing is located on multiple alluvial-pluvial fans with thick Quaternary unconsolidated sediments. It has suffered serious groundwater drawdown and land subsidence due to groundwater exploitation. This study aimed to introduce geographical distribution measure methods into land subsidence research characterizing, geographically, land subsidence, groundwater drawdown, and compressible layer thickness. Therefore, we used gravity center analysis and standard deviational ellipse (SDE methods in GIS to statistically analyze their concentration tendency, principle orientation, dispersion trend, and distribution differences in 1995 (1999, 2007, 2009, 2011, and 2013. Results show that they were all concentrated in Chaoyang District of Urban Beijing. The concentration trend of land subsidence was consistent with that of groundwater drawdown. The principle orientation of land subsidence was SW–NE, which was more similar with that of the static spatial distribution of the compressible layer. The dispersion tendency of land subsidence got closer to that of the compressible layer with its increasing intensity. The spatial distribution difference between land subsidence and groundwater drawdown was about 0.2, and that between land subsidence and compressible layer thickness it decreased from 0.22 to 0.07, reflecting that the spatial distribution pattern of land subsidence was increasingly close to that of the compressible layer. Results of this study are useful for assessing the distribution of land subsidence development and managing groundwater resources.

  3. Can forced hot air quickly dry feces on transport cage flooring and eliminate campylobacter before cage re-use? (United States)

    Allowing feces left on transport coops to dry is an effective way to reduce numbers of viable Campylobacter left by positive flocks. The problem with this approach is that poultry processors do not have the time, space or resources to maintain several times the minimum number of transport cages that...

  4. Porous silicon nitride spacers versus PEEK cages for anterior cervical discectomy and fusion: clinical and radiological results of a single-blinded randomized controlled trial. (United States)

    Arts, Mark P; Wolfs, Jasper F C; Corbin, Terry P


    Anterior cervical discectomy with fusion is a common procedure for treating radicular arm pain. Polyetheretherketone (PEEK) plastic is a frequently used material in cages for interbody fusion. Silicon nitride is a new alternative with desirable bone compatibility and imaging characteristics. The aim of the present study is to compare silicon nitride implants with PEEK cages filled with autograft harvested from osteophytes. The study is a prospective, randomized, blinded study of 100 patients with 2 years follow-up. The primary outcome measure was improvement in the Neck Disability Index. Other outcome measures included SF-36, VAS arm pain, VAS neck pain, assessment of recovery, operative characteristics, complications, fusion and subsidence based on dynamic X-ray and CT scan. There was no significant difference in NDI scores between the groups at 24 months follow-up. At 3 and 12 months the NDI scores were in favor of PEEK although the differences were not clinically relevant. On most follow-up moments there was no difference in VAS neck and VAS arm between both groups, and there was no statistically significant difference in patients' perceived recovery during follow-up. Fusion rate and subsidence were similar for the two study arms and about 90% of the implants were fused at 24 months. Patients treated with silicon nitride and PEEK reported similar recovery rates during follow-up. There was no significant difference in clinical outcome at 24 months. Fusion rates improved over time and are comparable between both groups.

  5. Initial experience with the use of an expandable titanium cage as a vertebral body replacement in patients with tumors of the spinal column: a report of 95 patients. (United States)

    Viswanathan, Ashwin; Abd-El-Barr, Muhammad M; Doppenberg, Egon; Suki, Dima; Gokaslan, Ziya; Mendel, Ehud; Rao, Ganesh; Rhines, Laurence D


    Vertebral body resection to treat spine tumors necessitates reconstruction to maintain spinal stability. The durability of reconstruction may be a challenge in cancer patients as treatment with chemotherapy and/or radiation coupled with poor nutritional status may compromise bone quality. We present a series of patients who underwent implantation of an expandable titanium cage (ETC) for reconstruction after vertebral body resection for primary or metastatic spine tumors. We report the functional outcome, assess the durability of reconstruction, and describe complications associated with this procedure. A retrospective review of patients undergoing placement of ETC after vertebrectomy for spinal tumor at our institution was performed. From September 2001 to August 2006, 95 patients underwent implantation of an ETC for reconstruction of the anterior spinal column following vertebrectomy for tumor (75 one-level, 19 two-level, 1 three-level). All patients underwent spinal stabilization as well. The median survival after surgery was 13.7 months; 23 patients had primary spinal tumors and 72 had metastatic tumors. Numerical pain scores were significantly improved postoperatively indicating a palliative benefit. No new neurological deficits were noted postoperatively, except when intentional neurological sacrifice was performed for oncologic reasons. Median height correction of 14% (range 0-118%) and median improvement in sagittal alignment of 6° (range 0-28°) were demonstrated on immediate postoperative imaging. Three patients experienced hardware related complications, one of which had posterior migration of the ETC. On postoperative imaging, 12 patients demonstrated subsidence of greater than 1 mm, but none required operative revision. Use of an ETC for spinal reconstruction in patients with spinal tumors is safe, decreases pain associated with pathologic fracture, protects neurologic function, and is durable. We found a very low incidence of cage-related construct

  6. Coral ages and island subsidence, Hilo drill hole (United States)

    Moore, J.G.; Ingram, B.L.; Ludwig, K. R.; Clague, D.A.


    A 25.8-m-thick sedimentary section containing coral fragments occurs directly below a surface lava flow (the ???1340 year old Panaewa lava flow) at the Hilo drill hole. Ten coral samples from this section dated by accelerator mass spectrometry (AMS) radiocarbon and five by thermal infrared multispectral scanner (TIMS) 230Th/U methods show good agreement. The calcareous unit is 9790 years old at the bottom and 1690 years old at the top and was deposited in a shallow lagoon behind an actively growing reef. This sedimentary unit is underlain by a 34-m-thick lava flow which in turn overlies a thin volcaniclastic silt with coral fragments that yield a single 14C date of 10,340 years. The age-depth relations of the dated samples can be compared with proposed eustatic sea level curves after allowance for island subsidence is taken. Island subsidence averages 2.2 mm/yr for the last 47 years based on measurements from a tide gage near the drill hole or 2.5-2.6 mm/yr for the last 500,000 years based on the ages and depths of a series of drowned coral reefs offshore from west Hawaii. The age-depth measurements of coral fragments are more consistent with eustatic sea levels as determined by coral dating at Barbados and Albrolhos Islands than those based on oxygen isotopic data from deep sea cores. The Panaewa lava flow entered a lagoon underlain by coral debris and covered the drill site with 30.9 m of lava of which 11 m was above sea level. This surface has now subsided to 4.2 m above sea level, but it demonstrates how a modern lava flow entering Hilo Bay would not only change the coastline but could extensively modify the offshore shelf.

  7. Comparison Between Acrylic Cage and Polyetheretherketone (PEEK) Cage in Single-level Anterior Cervical Discectomy and Fusion: A Randomized Clinical Trial. (United States)

    Farrokhi, Majid R; Nikoo, Zahra; Gholami, Mehrnaz; Hosseini, Khadijeh


    Prospective, single-blind randomized-controlled clinical study. To compare polyetheretherketone (PEEK) cage with a novel Acrylic cage to find out which fusion cage yielded better clinical outcomes following single-level anterior cervical discectomy and fusion (ACDF). ACDF is considered a standard neurosurgical treatment for degenerative diseases of cervical intervertebral disks. There are many options, including bone grafts, bone cement, and spacers made of titanium, carbon fiber, and synthetic materials, used to restore physiological disk height and enhance spinal fusion, but the ideal device, which would provide immediate structural support and subsequent osteointegration and stability, has not been identified yet. To overcome this, we designed a new, inexpensive Acrylic cage. A total of 64 patients were eligible to participate and were randomly allocated to undergo ACDF either with Acrylic interbody fusion cage filled with bone substitute (n=32) or PEEK cage (n=32). Nurick's grading was used for quantifying the neurological deficit. Clinical and radiologic outcome was assessed preoperatively, immediately after surgery, and subsequently at 2, 6, and 12 months of follow-up using Odom's criteria and dynamic radiographs (flexion-extension) and computed tomography scans, respectively. There was a statistically significant improvement in the clinical outcomes of the Acrylic cage group compared with the PEEK cage group (mean difference: -0.438; 95% confidence interval, -0.807 to -0.068; P=0.016). There was a statistically significant difference in disk space height increase between the 2 groups at the 6- and 12-month follow-up. The Acrylic cage achieved higher fusion rate (good fusion) than the PEEK cage (96.9% vs. 93.8%). Intervertebral angle demonstrated a significant difference among the 2 treated groups throughout the follow-up period. This study suggests that the use of Acrylic cage is associated with good clinical and radiologic outcomes and it can be therefore a

  8. Ground subsidence information as a valuable layer in GIS analysis

    Directory of Open Access Journals (Sweden)

    Murdzek Radosław


    Full Text Available Among the technologies used to improve functioning of local governments the geographic information systems (GIS are widely used. GIS tools allow to simultaneously integrate spatial data resources, analyse them, process and use them to make strategic decisions. Nowadays GIS analysis is widely used in spatial planning or environmental protection. In these applications a number of spatial information are utilized, but rarely it is an information about environmental hazards. This paper includes information about ground subsidence that occurred in USCB mining area into GIS analysis. Monitoring of this phenomenon can be carried out using the radar differential interferometry (DInSAR method.

  9. Sedimentation, accretion, and subsidence in marshes of Barataria Basin, Louisiana

    International Nuclear Information System (INIS)

    Hatton, R.S.; DeLaune, R.D.; Patrick, W.H. Jr.


    Vertical accretion and sediment accumulation rates were determined from the distribution of 137 Cs in cores collected from fresh water, intermediate, brackish, and salt marshes in the Barataria Basin, Louisiana. Vertical accretion rates vary from about 1.3 cm.yr -1 in levee areas to 0.7 in backmarshes. Mineral sediment content of the marsh soil profile decreased with distance from the coast. Except in natural levee areas, marsh accretion rates are less than subsidence measured by water level data, however this alone cannot account for observed land-loss patterns in the basin area

  10. Effects of coal mine subsidence in the Sheridan, Wyoming, area (United States)

    Dunrud, C. Richard; Osterwald, Frank W.


    Analyses of the surface effects of past underground coal mining in the Sheridan, Wyoming, area suggest that underground mining of strippable coal deposits may damage the environment more over long periods of time than would modern surface mining, provided proper restoration procedures are followed after surface mining. Subsidence depressions and pits are a continuing hazard to the environment and to man's activities in the Sheridan, Wyo., area above abandoned underground mines in weak overburden less than about 60 m thick and where the overburden is less than about 10-15 times the thickness of coal mined. In addition, fires commonly start by spontaneous ignition when water and air enter the abandoned mine workings via subsidence cracks and pits. The fires can then spread to unmined coal as they create more cavities, more subsidence, and more cracks and pits through which air can circulate. In modern surface mining operations the total land surface underlain by minable coal is removed to expose the coal. The coal is removed, the overburden and topsoil are replaced, and the land is regraded and revegetated. The land, although disturbed, can be more easily restored and put back into use than can land underlain by abandoned underground mine workings in areas where the overburden is less than about 60 m thick or less than about 10-15 times the thickness of coal mined. The resource recovery of modern surface mining commonly is much greater than that of underground mining procedures. Although present-day underground mining technology is advanced as compared to that of 25-80 years ago, subsidence resulting from underground mining of thick coal beds beneath overburden less than about 60 m thick can still cause greater damage to surface drainage, ground water, and vegetation than can properly designed surface mining operations. This report discusses (11 the geology and surface and underground effects of former large-scale underground coal mining in a 50-km 2 area 5-20 km

  11. Effects of single caging and cage size on behavior and stress level of domestic neutered cats housed in an animal shelter. (United States)

    Uetake, Katsuji; Goto, Akihiro; Koyama, Rumi; Kikuchi, Rieko; Tanaka, Toshio


    Cats need a minimum amount of space even in animal shelters. In this study the effects of single caging and cage size on the behavior and stress level of domestic cats were investigated. Six neutered cats (2-15 years old) that had been housed in a group for at least 7 months were moved to three kinds of single cages (small, medium and large) by rotation on a Latin square design. They experienced each cage size for 6 days. Cats could use vertical dimensions when housed in a group room and the large cage. Behavioral observation was conducted for 3 h in the evening, and stress levels were assessed by urine cortisol-to-creatinine ratios. The amounts (estimated proportions) of time spent in locomotion and social/solitary play were lower even in large cages than in group housing (both P housed singly (P = 0.104). The urine cortisol-to-creatinine ratios of singly housed cats tended to be higher than that of group-housed cats (P = 0.086). The results indicate that cats become less active when they are housed singly in cages regardless of the cage size. Cats seem to feel no undue stress even in small cages if the stay is short. © 2012 The Authors. Animal Science Journal © 2012 Japanese Society of Animal Science.

  12. Transforaminal lumbar interbody fusion using one diagonal fusion cage with unilateral pedicle screw fixation for treatment of massive lumbar disc herniation. (United States)

    Zhao, Chang-Qing; Ding, Wei; Zhang, Kai; Zhao, Jie


    Large lumbar or lumbosacral (LS) disc herniations usually expand from the paramedian space to the neuroforamen and compress both the transversing (lower) and the exiting (upper) nerve roots, thus leading to bi-radicular symptoms. Bi-radicular involvement is a statistically significant risk factor for poor outcome in patients presenting with far lateral or foraminal disc herniation after facet preserving microdecompression. There is evidence showing that patients suffering from large lumbar disc herniations treated with interbody fusion have significant superior results in comparison with those who received a simple discectomy. We report our experiences on managing large LS disc herniation with bi-radicular symptoms by transforaminal lumbar interbody fusion (TLIF) using one diagonal fusion cage with unilateral pedicle screw/rod fixation. Twenty-three patients who suffered from single level lumbar or LS disc herniation with bi-radicular symptoms treated with unilateral decompression and TLIF using one diagonal fusion cage with ipsilateral pedicle screw/rod fixation operated between January 2005 and December 2009, were included in this study. Operation time and blood loss were recorded. The pain and disability status were pre- and postoperatively evaluated by the visual analog score (VAS) and Oswestry Disability Index (ODI). Interbody bony fusion was detected by routine radiographs and computed tomography scan. Adjacent segment degeneration was detected by routine radiographs and magnetic resonance imaging examination. Overall outcomes were categorized according to modified Macnab classification. The patients were followed up for an average of 44.7 months. Pain relief in the VAS and improvement of the ODI were significant after surgery and at final followup. No severe complications occurred during hospital stay. Interbody bony fusion was achieved in every case. No cage retropulsion was observed, while 3 cases experienced cage subsidence. Adjacent segment degeneration

  13. Application of InSAR and Gravimetry for Land Subsidence Hazard Zoning in Aguascalientes, Mexico


    Pacheco-Martínez, Jesús; Cabral-Cano, Enrique; Wdowinski, Shimon; Hernández-Marín, Martín; Ortiz-Lozano, José; Zermeño-de-León, Mario


    In this work we present an application of InSAR and gravimetric surveys for risk management related to land subsidence and surface ground faulting generation. A subsidence velocity map derived from the 2007–2011 ALOS SAR imagery and a sediment thicknesses map obtained from the inversion of gravimetric data were integrated with a surface fault map to produce a subsidence hazard zoning in the city of Aguascalientes, Mexico. The resulting zoning is presented together with specific recommendation...

  14. The analysis of subsidence associated with geothermal development. Volume 1. Handbook

    Energy Technology Data Exchange (ETDEWEB)

    Atherton, R.W.; Finnemore, E.J.; Gillam, M.L.


    This study evaluates the state of knowledge of subsidence associated with geothermal development, and provides preliminary methods to assess the potential of land subsidence for any specific geothermal site. The results of this study are presented in three volumes. Volume 1 is designed to serve as a concise reference, a handbook, for the evaluation of the potential for land subsidence from the development of geothermal resources.

  15. Groundwater-abstraction induced land subsidence and groundwater regulation in the North China Plain


    Guo, H.; Wang, L.; Cheng, G.; Zhang, Z.


    Land subsidence can be induced when various factors such as geological, and hydrogeological conditions and intensive groundwater abstraction combine. The development and utilization of groundwater in the North China Plain (NCP) bring great benefits, and at the same time have led to a series of environmental and geological problems accompanying groundwater-level declines and land subsidence. Subsidence occurs commonly in the NCP and analyses show that multi-layer aquifer syst...

  16. Impacts of 25 years of groundwater extraction on subsidence in the Mekong delta, Vietnam


    Minderhoud, P.S.J.; Erkens, G.; van Pham, H.; Bui, Vuong Tran; Erban, Laura; Kooi, Henk; Stouthamer, E.


    Many major river deltas in the world are subsiding and consequently become increasingly vulnerable to flooding and storm surges, salinization and permanent inundation. For the Mekong Delta, annual subsidence rates up to several centimetres have been reported. Excessive groundwater extraction is suggested as the main driver. As groundwater levels drop, subsidence is induced through aquifer compaction. Over the past 25 years, groundwater exploitation has increased dramatically, transforming the...

  17. Case study in monitoring mining induced subsidence using photogrammetry and conventional surveys

    International Nuclear Information System (INIS)

    Fry, R.C.


    This paper reports that underground coal mining has been active within the East Mountain property since the mid 1950's. As a result, coal from two seams has been extracted within large areas allowing surface subsidence to occur. Monitoring of subsidence annually began in 1981 using on the ground conventional monumentation, surveying and photogrammetry monitoring. The data collected has shown the time benefits of photogrammetry and the relationship between observed subsidence and the geometry of the mined out area below

  18. Assessing the potential of the multi-aquifer subsurface of the Mekong Delta (Vietnam for land subsidence due to groundwater extraction

    Directory of Open Access Journals (Sweden)

    P. S. J. Minderhoud


    Full Text Available Land subsidence rates of ~ 1–4 cm yr−1 are measured in the low-lying Vietnamese Mekong Delta. These relatively high subsidence rates are attributed to groundwater extraction, which has increased drastically over the past decades due to growing domestic, agricultural and industrial demands. As a result, hydraulic heads in aquifers are dropping, on average 0.3–0.7 m yr−1. There is an urgent need to go from measurements to predictions in order to test possible future groundwater management scenarios and to reduce the increase of flood risk, salt water intrusion and, on the longer term, prevent the delta from drowning. In this study, we aim to assess the subsidence potential of the multi-aquifer subsurface of the Mekong delta due to groundwater extraction. The first step is to gain a thorough understanding of the complex sedimentary architecture of the heterogeneous subsurface. Combined with the related geotechnical properties, the subsurface build-up determines the subsidence potential. Here, we present our approach to develop a 3-D geo-hydrological model based on lithological borehole data, geophysical sedimentary properties, palaeogeography and conceptual models of delta evolution.

  19. State and local response to damaging land subsidence in United States urban areas (United States)

    Holzer, T.L.


    Land subsidence caused by man-induced depressuring of underground reservoirs has occurred in at least nine urban areas in the United States. Significant efforts to control it have been made in three areas: Long Beach, California; Houston-Galveston, Texas; and Santa Clara Valley, California. In these areas coastal flooding and its control cost more than $300 million. Institutional changes were required in each area to ameliorate its subsidence problem. In Long Beach and Houston Galveston, efforts were made to mitigate subsidence only after significant flood damage had occurred. To arrest subsidence at Long Beach, the city lobbied for a special state law, the California Subsidence Act, that required unitization and repressuring of the Wilmington oil field. In the Houston-Galveston region, the Texas State Legislature authorized formation of the Harris-Galveston Coastal Subsidence District with authority to regulate groundwater pumping by permit. This solution, which was achieved through efforts of entities affected by subsidence, was the product of a series of compromises necessitated by political fragmentation and disjointed water planning in the region. Amelioration of subsidence in the Santa Clara Valley was a collateral benefit from the effort by water users to curtail ground-water overdraft in the valley. Importation of surface water and a tax on ground-water pumpage reduced ground-water use, thereby allowing the recovery of water level and the arresting of subsidence.

  20. Land subsidence and relative sea-level rise in the southern Chesapeake Bay region (United States)

    Eggleston, Jack; Pope, Jason


    The southern Chesapeake Bay region is experiencing land subsidence and rising water levels due to global sea-level rise; land subsidence and rising water levels combine to cause relative sea-level rise. Land subsidence has been observed since the 1940s in the southern Chesapeake Bay region at rates of 1.1 to 4.8 millimeters per year (mm/yr), and subsidence continues today. This land subsidence helps explain why the region has the highest rates of sea-level rise on the Atlantic Coast of the United States. Data indicate that land subsidence has been responsible for more than half the relative sea-level rise measured in the region. Land subsidence increases the risk of flooding in low-lying areas, which in turn has important economic, environmental, and human health consequences for the heavily populated and ecologically important southern Chesapeake Bay region. The aquifer system in the region has been compacted by extensive groundwater pumping in the region at rates of 1.5- to 3.7-mm/yr; this compaction accounts for more than half of observed land subsidence in the region. Glacial isostatic adjustment, or the flexing of the Earth’s crust in response to glacier formation and melting, also likely contributes to land subsidence in the region.

  1. Analysis of subsidence in northeastern Venezuela as a discriminator of tectonic models for northern South America (United States)

    Erikson, Johan P.; Pindell, James L.


    Subsidence analysis of northeastern Venezuela's exposed, parautochthonous Lower Cretaceous-Miocene sedimentary section reveals an Atlantic-type passive-margin subsidence history for the entire Cretaceous-middle Eocene interval; Oligocene-Miocene subsidence was rapid and great and was caused by foredeep formation and emplacement of the fold-and-thrust belt that now exposes the passive-margin sedimentary section. Our analyses support tectonic models of South America's northern margin which propose Cenozoic eastward migration of a foredeep along northern South America's late Mesozoic passive margin. The calculated subsidence is inconsistent with tectonic models that propose middle or Late Cretaceous subduction or obduction.

  2. Monitoring Mining Subsidence Using A Combination of Phase-Stacking and Offset-Tracking Methods


    Fan, Hongdong; Gao, Xiaoxiong; Yang, Junkai; Deng, Kazhong; Yu, Yang


    An approach to study the mechanism of mining-induced subsidence, using a combination of phase-stacking and sub-pixel offset-tracking methods, is reported. In this method, land subsidence with a small deformation gradient was calculated using time-series differential interferometric synthetic aperture radar (D-InSAR) data, whereas areas with greater subsidence were calculated by a sub-pixel offset-tracking method. With this approach, time-series data for mining subsidence were derived in Yuli...

  3. Geotechnical and Geological Aspects of Differential Subsidence in the Skaw Spit, Denmark

    DEFF Research Database (Denmark)

    Andersen, Holger Lykke; Thorsen, Grete; Hauerbach, P.


    Local differential subsidence has been observed by means of repeated precise levellings in the township of Skagen at the northernmost tip of the Skaw Spit in Jutland. We have l studied the possible causes of the subsidence. Oedometer tests have been carried out on undisturbed clayey samples from...... supply wells, and filling in the harbour area seem to be insufficient to account for the subsidence. In the Quaternary the seismic profiles indicate dislocations that may be related to faults in the pre-Quaternary substratum. A relationship between the subsidence and active faulting is considered...

  4. Application of InSAR and Gravimetry for Land Subsidence Hazard Zoning in Aguascalientes, Mexico

    Directory of Open Access Journals (Sweden)

    Jesús Pacheco-Martínez


    Full Text Available In this work we present an application of InSAR and gravimetric surveys for risk management related to land subsidence and surface ground faulting generation. A subsidence velocity map derived from the 2007–2011 ALOS SAR imagery and a sediment thicknesses map obtained from the inversion of gravimetric data were integrated with a surface fault map to produce a subsidence hazard zoning in the city of Aguascalientes, Mexico. The resulting zoning is presented together with specific recommendations about geotechnical studies needed for further evaluation of surface faulting in these hazard zones. The derived zoning map consists in four zones including null hazard (stable terrain without subsidence, low hazard (areas prone to subsidence, medium hazard (zones with subsidence and high hazard (zones with surface faulting. InSAR results displayed subsidence LOS velocities up to 10 cm/year and two subsidence areas unknown before this study. Gravimetric results revealed that the thicker sediment sequence is located toward north of Aguascalientes City reaching up to 600 m in thickness, which correspond to a high subsidence LOS velocity zone (up to 6 cm/year.

  5. Stem subsidence after total hip revision: 183 cases at 5.9 years follow-up. (United States)

    Girard, J; Roche, O; Wavreille, G; Canovas, F; Le Béguec, P


    Secondary subsidence of a revision femoral stem is often a negative predictive sign for successful osseointegration and perfect long-term stability. We performed a retrospective study in a series of 183 revision total hip replacements between 1996 and 2000 to evaluate the importance and risk factors of secondary subsidence with a cementless press-fit design femoral stem as well as this subsidence's consequences to osseointegration. Secondary subsidence did not occur in 80 cases (53%), was between 0 and 4mm in 41 cases (27%); between 5 and 10mm in 17 cases (12%) and was greater than 10mm in 12 cases (8%). Mean subsidence of all patients was 3mm (0-30). There was a statistically significant negative correlation between subsidence and the quality of osseointegration (P=0.03). There was no significant relationship between component diameter and stem subsidence (P=0.9). The presence of preoperative bone deficiencies did not increase the risk of secondary subsidence (P=0.2). In the case of revision with press-fit stems, the importance of secondary subsidence should not be overestimated, because it usually does not negatively affect satisfactory osseointegration. Copyright © 2011 Elsevier Masson SAS. All rights reserved.

  6. E-Area LLWF Vadose Zone Model: Probabilistic Model for Estimating Subsided-Area Infiltration Rates

    Energy Technology Data Exchange (ETDEWEB)

    Dyer, J. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Flach, G. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)


    A probabilistic model employing a Monte Carlo sampling technique was developed in Python to generate statistical distributions of the upslope-intact-area to subsided-area ratio (AreaUAi/AreaSAi) for closure cap subsidence scenarios that differ in assumed percent subsidence and the total number of intact plus subsided compartments. The plan is to use this model as a component in the probabilistic system model for the E-Area Performance Assessment (PA), contributing uncertainty in infiltration estimates.

  7. Cathodic cage nitriding of samples with different dimensions

    International Nuclear Information System (INIS)

    Sousa, R.R.M. de; Araujo, F.O. de; Ribeiro, K.J.B.; Mendes, M.W.D.; Costa, J.A.P. da; Alves, C.


    A series of AISI 1020 steel cylindrical samples with different heights were simultaneously nitrided in cathodic cage plasma nitriding. In this technique, the samples are placed under a floating potential inside a cage in which the cathodic potential is applied. A systematic study of the nitriding temperature variation effects was carried out in order to evaluate the efficiency of such a technique over the uniformity of the formed layers. The samples were characterized by optical microscopy, X-ray diffraction and microhardness measurement. The results were compared with those ones obtained in the ionic nitriding, and was verified that the samples nitrided by this conventional technique presents less uniformity than the ones treated through this new technique

  8. Cathodic cage nitriding of samples with different dimensions

    Energy Technology Data Exchange (ETDEWEB)

    Sousa, R.R.M. de [Centro Federal de Educacao Tecnologica do Piaui, Department of Mechanical, Teresina, PI (Brazil); Araujo, F.O. de [Universidade Federal Rural do Semi-Arido, Mossoro, RN (Brazil); Ribeiro, K.J.B.; Mendes, M.W.D. [Labplasma, Departamento de Fisica-UFRN, Campus Universitario, 59072-970 Natal, RN (Brazil); Costa, J.A.P. da [Departamento de Fisica-UFC, Fortaleza, CE (Brazil); Alves, C. [Labplasma, Departamento de Fisica-UFRN, Campus Universitario, 59072-970 Natal, RN (Brazil)], E-mail:


    A series of AISI 1020 steel cylindrical samples with different heights were simultaneously nitrided in cathodic cage plasma nitriding. In this technique, the samples are placed under a floating potential inside a cage in which the cathodic potential is applied. A systematic study of the nitriding temperature variation effects was carried out in order to evaluate the efficiency of such a technique over the uniformity of the formed layers. The samples were characterized by optical microscopy, X-ray diffraction and microhardness measurement. The results were compared with those ones obtained in the ionic nitriding, and was verified that the samples nitrided by this conventional technique presents less uniformity than the ones treated through this new technique.

  9. The BetaCage: Ultrasensitive Screener for Radioactive Backgrounds (United States)

    Thompson, Michael; BetaCage Collaboration


    Rare event searches, such as dark matter detection and neutrinoless double beta decay, require screening of materials for backgrounds such as beta emission and alpha decaying isotopes. The BetaCage is a proposed ultra-sensitive time-projection chamber to screen for alpha-emitting and low energy beta-emitting (10-200 keV) contaminants. The expected sensitivity is 0.1 beta particles (perkeV -m2 - day) and 0.1 alpha particles (perm2 - day) , where the former will be limited by Compton scattering of external photons in the screening samples and the latter is expected to be signal-limited. The prototype BetaCage under commissioning at South Dakota School of Mines & Technology is filled with P10 gas (10% methane, 90% argon) in place of neon and is 40×40×20 cm in size. Details on design, construction and characterization will be presented.

  10. Segmental kyphosis after cervical interbody fusion with stand-alone polyetheretherketone (PEEK) cages: a comparative study on 2 different PEEK cages. (United States)

    Kim, Chi Heon; Chung, Chun Kee; Jahng, Tae-Ahn; Park, Sung Bae; Sohn, Seil; Lee, Sungjoon


    Retrospective comparative study. Two polyetheretherketone (PEEK) cages of different designs were compared in terms of the postoperative segmental kyphosis after anterior cervical discectomy and fusion. Segmental kyphosis occasionally occurs after the use of a stand-alone cage for anterior cervical discectomy and fusion. Although PEEK material seems to have less risk of segmental kyphosis compared with other materials, the occurrence of segmental kyphosis for PEEK cages has been reported to be from 0% to 29%. There have been a few reports that addressed the issue of PEEK cage design. A total of 41 consecutive patients who underwent single-level anterior discectomy and fusion with a stand-alone cage were included. Either a round tube-type (Solis; 18 patients, S-group) or a trapezoidal tube-type (MC+; 23 patients, M-group) cage was used. The contact area between the cage and the vertebral body is larger in MC+ than in Solis, and anchoring pins were present in the Solis cage. The effect of the cage type on the segmental angle (SA) (lordosis vs. kyphosis) at postoperative month 24 was analyzed. Preoperatively, segmental lordosis was present in 12/18 S-group and 16/23 M-group patients (P=0.84). The SA was more lordotic than the preoperative angle in both groups just after surgery, with no difference between groups (P=0.39). At 24 months, segmental lordosis was observed in 9/18 S-group and 20/23 M-group patients (P=0.01). The patients in M-group were 7.83 times more likely than patients in S-group (P=0.04; odds ratio, 7.83; 95% confidence interval, 1.09-56.28) not to develop segmental kyphosis. The design of the PEEK cage used may influence the SA, and this association needs to be considered when using stand-alone PEEK cages.

  11. Cage structure application in photoelectric experiment and teaching (United States)

    Li, Xiufang; Zhao, Peng; Liu, Shugang


    A new type of photoelectric system structure, cage system, is introduced. This kind of coaxial modularized structure not only can be quickly assembled, but also can easily realize different purposes by substituting elements in the system. In addition, it's light and portable, which enable teachers to carry it to wherever suitable for teaching. In conclusion, this structure can improve teaching effect and stimulate student's interest in photoelectric courses.

  12. Pulsed EPR characterization of encapsulated atomic hydrogen in octasilsesquioxane cages. (United States)

    Mitrikas, George


    Hydrogen atoms encapsulated in molecular cages are potential candidates for quantum computing applications. They provide the simplest two-spin system where the 1s electron spin, S = 1/2, is hyperfine-coupled to the proton nuclear spin, I = 1/2, with a large isotropic hyperfine coupling (A = 1420.40575 MHz for a free atom). While hydrogen atoms can be trapped in many matrices at cryogenic temperatures, it has been found that they are exceptionally stable in octasilsesquioxane cages even at room temperature [Sasamori et al., Science, 1994, 256, 1691]. Here we present a detailed spin-lattice and spin-spin relaxation study of atomic hydrogen encapsulated in Si(8)O(12)(OSiMe(2)H)(8) using X-band pulsed EPR spectroscopy. The spin-lattice relaxation times T(1) range between 1.2 s at 20 K and 41.8 μs at room temperature. The temperature dependence of the relaxation rate shows that for T 100 K a thermally activated process with activation energy E(a) = 753 K (523 cm(-1)) prevails. The phase memory time T(M) = 13.9 μs remains practically constant between 200 and 300 K and is determined by nuclear spin diffusion. At lower temperatures T(M) decreases by an order of magnitude and exhibits two minima at T = 140 K and T = 60 K. The temperature dependence of T(M) between 20 and 200 K is attributed to dynamic processes that average inequivalent hyperfine couplings, e.g. rotation of the methyl groups of the cage organic substituents. The hyperfine couplings of the encapsulated proton and the cage (29)Si nuclei are obtained through numerical simulations of field-swept FID-detected EPR spectra and HYSCORE experiments, respectively. The results are discussed in terms of existing phenomenological models based on the spherical harmonic oscillator and compared to those of endohedral fullerenes.

  13. Energy saving work of frequency controlled induction cage machine

    International Nuclear Information System (INIS)

    Gnacinski, P.


    Energy saving work, understood as lowering the supply voltage when load torque is much less than rated, is one way of reducing power losses in an induction cage machine working with a variable load. Reduction in power losses also affects the thermal properties of an induction machine because the energy saving work allows the temperature rise of the windings to decrease. Thanks to a lower temperature of the windings, the same load torque can be carried by a machine of less rated power. The ability of energy saving work to reduce the temperature of windings depends on the thermal properties of an induction machine, which are different in the case of a machine with foreign ventilation and its own ventilation. This paper deals with the thermal effect of energy saving work on a frequency controlled induction cage machine. A comparison of the properties of a machine with its own and outside ventilation is presented. The results of the investigations are shown for a 3 kW induction cage machine with the two previously mentioned ways of ventilation: one provided with a fan placed on a shaft and the other provided with a fan driven by an auxiliary motor

  14. Experience with titanium cages in anterior cervical discectomy and fusion

    International Nuclear Information System (INIS)

    Junaid, M.; Afsheen, A.; Bukhari, S.S.; Rashid, M.U.; Kalsoom, A.


    Background: Anterior cervical discectomy is a common procedure for treating patients for cervical disc prolapse. This study was conducted to study the surgical outcome and demographic characteristics of patients who were treated for anterior cervical disc prolapse. Methods: Study was conducted in the combined military hospital (CMH) Peshawar. Study interval was 3 years from 1st September, 2011 to 31st August, 2014. Total number of patients were 84. Males were 54 (64.28 percentage) and females were 30 (35.71 percentage). All the patients had undergone the procedure of anterior cervical discectomy and fusion with titanium cages (ACDF). All the patients had plain MRI cervical spine done for diagnosis of anterior cervical disc prolapse. Results: Total 84 patients were operated. In the patients who complained of brachialgia, 100 percentage improvement was seen after the operation. Three (3.5 percentage) of the patients, who presented with axial neck pain, continued to complain of pain and 2 (2.5 percentage) of the patients complained of pain at the donor site after the operation. One of the patient had dural tear which resulted in subcutaneous cerebrospinal fluid (CSF) accumulation and was treated conservatively with repeated aspiration. Fusion rate was 100 percentage with titanium cages used for fusion after anterior cervical discectomy. No complications were noted after the surgery at 1 year of interval. Conclusion: Results with titanium cages are expectedly good. Symptoms resolved and fusion rate was 100 percentage at 1 year follow up. (author)

  15. Effects of Titanium Mesh Cage End Structures on the Compressive Load at the Endplate Interface: A Cadaveric Biomechanical Study. (United States)

    Lu, Teng; Liang, Hui; Liu, Chao; Guo, Shuai; Zhang, Ting; Yang, Baohui; He, Xijing


    BACKGROUND This study aimed to evaluate whether obliquely angled and ring-shaped titanium mesh cage (TMC) end structures can improve the compressive load on the endplate interface in anterior cervical corpectomy and fusion (ACCF). MATERIAL AND METHODS A total of 23 volunteers underwent cervical lateral x-ray. The oblique angle of the superior endplate was measured, which was used to construct the gradient of the TMC end. Forty-two fresh cadaveric vertebral bodies were harvested and randomly distributed among four TMC groups with different ends. The baseline indicators of bone mineral density and anteroposterior and transverse dimensions were recorded. The superior endplate was placed at an angle of 12° when performing uniaxial compression testing. The maximum loads of the four TMCs were assessed. RESULTS There were no significant differences among the groups regarding the baseline indicators. The conventional TMC had the lowest maximum load (1362.3±221.78 N, pend ring had the highest maximum load (2095.82±285.64 N, pend ring were much higher than that of the conventional TMC (pend ring (paverage values of 1806.91±246.98 N and 1725.3±213.33 N, respectively. CONCLUSIONS Both the ring shape and oblique angle of the TMC end contributed to an increase in compressive force and are advocated for use in TMC structure optimization to decrease the incidence of TMC subsidence in ACCF.

  16. Dynamic modeling of an asynchronous squirrel-cage machine; Modelisation dynamique d'une machine asynchrone a cage

    Energy Technology Data Exchange (ETDEWEB)

    Guerette, D.


    This document presented a detailed mathematical explanation and validation of the steps leading to the development of an asynchronous squirrel-cage machine. The MatLab/Simulink software was used to model a wind turbine at variable high speeds. The asynchronous squirrel-cage machine is an electromechanical system coupled to a magnetic circuit. The resulting electromagnetic circuit can be represented as a set of resistances, leakage inductances and mutual inductances. Different models were used for a comparison study, including the Munteanu, Boldea, Wind Turbine Blockset, and SimPowerSystem. MatLab/Simulink modeling results were in good agreement with the results from other comparable models. Simulation results were in good agreement with analytical calculations. 6 refs, 2 tabs, 9 figs.

  17. Validation of a self-administered modified CAGE test (CAGE-C) in a somatic hospital ward: comparison with biochemical markers

    DEFF Research Database (Denmark)

    Zierau, F; Hardt, F; Henriksen, Jens Henrik Sahl


    Objective. The time frame for the original CAGE questionnaire is lifetime and it does not quantify drinking frequency and may be less suitable in a population with very few teetotalers. The purpose of this study was to validate a variant of the CAGE questionnaire and compare it with the outcome...

  18. Cage drying and the application of a dry treatment (absorbent cornstarch powder) as a means to diminish Campylobacter on transport cages. (United States)

    Broiler transport cages soiled with Campylobacter-positive feces have been shown to facilitate cross contamination of broilers. Campylobacter organisms are sensitive to dry stress. Allowing feces left on transport cage flooring to dry during extended periods of nonuse would be an effective method ...

  19. New caged neurotransmitter analogs selective for glutamate receptor sub-types based on methoxynitroindoline and nitrophenylethoxycarbonyl caging groups

    Czech Academy of Sciences Publication Activity Database

    Palma-Cerda, F.; Auger, C.; Crawford, D.J.; Hodgson, A.C.C.; Reynolds, S.J.; Cowell, J.K.; Swift, K.A.D.; Cais, Ondřej; Vyklický ml., Ladislav; Corrie, J.E.T.; Ogden, D.


    Roč. 63, č. 4 (2012), s. 624-634 ISSN 0028-3908 R&D Projects: GA ČR(CZ) GA309/07/0271 Grant - others:EC(XE) LSHM-CT-2007-037765 Institutional research plan: CEZ:AV0Z50110509 Keywords : photolysis * glutamate receptors * caged neurotransmitters Subject RIV: ED - Physiology Impact factor: 4.114, year: 2012

  20. Development of 4-methoxy-7-nitroindolinyl (MNI)-caged auxins which are extremely stable in planta. (United States)

    Hayashi, Ken-Ichiro; Kusaka, Naoyuki; Yamasaki, Soma; Zhao, Yunde; Nozaki, Hiroshi


    Phytohormone auxin is a master regulator in plant growth and development. Regulation of cellular auxin level plays a central role in plant development. Auxin polar transport system modulates an auxin gradient that determines plant developmental process in response to environmental conditions and developmental programs. Photolabile caged auxins allow optical control of artificial auxin gradients at cellular resolution. Especially, two-photon uncaging system achieves high spatiotemporal control of photolysis reaction at two-photon cross-section. However, the development of caged versions of auxin has been limited by the instability of the caged auxins to higher plant metabolic activities. Here, we describe the synthesis and application of highly stable caged auxins, 4-methoxy-7-nitroindolinyl (MNI)-caged auxins. Natural auxin, indole 3-acetic acid, and two synthetic auxins, 1-NAA and 2,4-D were caged by MNI caging group. MNI-caged auxins showed a high stability in planta and a rapid release the original auxin when photolyzed. We demonstrated that optical control of auxin-responsive gene expression and auxin-related physiological responses by using MNI-caged auxins. We anticipate that MNI-caged auxins will be an effective tool for high-resolution control of endogenous auxin level. Copyright © 2015 Elsevier Ltd. All rights reserved.

  1. Effects of Furnished Cage Type on Behavior and Welfare of Laying Hens (United States)

    Li, Xiang; Chen, Donghua; Li, Jianhong; Bao, Jun


    This study was conducted to compare the effects of layout of furniture (a perch, nest, and sandbox) in cages on behavior and welfare of hens. Two hundred and sixteen Hyline Brown laying hens were divided into five groups (treatments) with four replicates per group: small furnished cages (SFC), medium furnished cages type I (MFC-I), medium furnished cages type II (MFC-II), and medium furnished cages type III (MFC-III) and conventional cages (CC). The experiment started at 18 week of age and finished at 52 week of age. Hens’ behaviors were filmed during the following periods: 8:00 to 10:00; 13:00 to 14:00; 16:00 to 17:00 on three separate days and two hens from each cage were measured for welfare parameters at 50 wk of age. The results showed that feeding and laying of all hens showed no effect by cage type (p>0.05), and the hens in the furnished cages had significantly lower standing and higher walking than CC hens (phens between the furnished cages (p>0.05). The hens in MFC-I, −II, and −III showed a significant higher socializing behavior than SFC and CC (phens in SFC and the highest perching found for the hens in MFC-III. Overall, the hens in CC showed poorer welfare conditions than the furnished cages, in which the feather condition score, gait score and tonic immobility duration of the hens in CC was significantly higher than SFC, MFC-I, MFC-II, and MFC-III (phens. Overall, MFC-III cage design was better than SFC, MFC-I, and MFC-II cage designs. PMID:26954171

  2. Effects of Furnished Cage Type on Behavior and Welfare of Laying Hens

    Directory of Open Access Journals (Sweden)

    Xiang Li


    Full Text Available This study was conducted to compare the effects of layout of furniture (a perch, nest, and sandbox in cages on behavior and welfare of hens. Two hundred and sixteen Hyline Brown laying hens were divided into five groups (treatments with four replicates per group: small furnished cages (SFC, medium furnished cages type I (MFC-I, medium furnished cages type II (MFC-II, and medium furnished cages type III (MFC-III and conventional cages (CC. The experiment started at 18 week of age and finished at 52 week of age. Hens’ behaviors were filmed during the following periods: 8:00 to 10:00; 13:00 to 14:00; 16:00 to 17:00 on three separate days and two hens from each cage were measured for welfare parameters at 50 wk of age. The results showed that feeding and laying of all hens showed no effect by cage type (p>0.05, and the hens in the furnished cages had significantly lower standing and higher walking than CC hens (p0.05. The hens in MFC-I, −II, and −III showed a significant higher socializing behavior than SFC and CC (p<0.05. The lowest perching was for the hens in SFC and the highest perching found for the hens in MFC-III. Overall, the hens in CC showed poorer welfare conditions than the furnished cages, in which the feather condition score, gait score and tonic immobility duration of the hens in CC was significantly higher than SFC, MFC-I, MFC-II, and MFC-III (p<0.05. In conclusion, the furnished cage design affected both behavior and welfare states of hens. Overall, MFC-III cage design was better than SFC, MFC-I, and MFC-II cage designs.

  3. Convergence models for cylindrical caverns and the resulting ground subsidence

    Energy Technology Data Exchange (ETDEWEB)

    Haupt, W.; Sroka, A.; Schober, F.


    The authors studied the effects of different convergence characteristics on surface soil response for the case of narrow, cylindrical caverns. Maximum ground subsidence - a parameter of major importance in this type of cavern - was calculated for different convergence models. The models were established without considering the laws of rock mechanics and rheology. As a result, two limiting convergence models were obtained that describe an interval of expectation into which all other models fit. This means that ground movements over cylindrical caverns can be calculated ''on the safe side'', correlating the trough resulting on the surface with the convergence characterisitcs of the cavern. Among other applications, the method thus permits monitoring of caverns.

  4. Continuous lift piers: Damage repair and response during subsidence

    International Nuclear Information System (INIS)

    Drumm, E.C.; Bennett, R.M.; Raaf, D.B.; Daugherty, D.


    A series of test foundations damaged during a longwall mining operation were left with permanent tilt, curvature, and substantial cracking. Two of the foundations were releveled using continuous lift piers. The continuous lift piers removed the tilt and curvature and significantly reduced the width of the foundation cracks. Following the releveling of the foundations, an adjacent longwall panel was mined, resulting in additional subsidence, although of smaller magnitude. The response of the releveled foundations was monitored and compared with the response of a footing that was not releveled. Although the continuous pier system does not strengthen the structure and distortion was observed during the second event, the system permitted the deformations to be removed in a few hours

  5. Vision Impairment Among Older Adults Residing in Subsidized Housing Communities. (United States)

    Elliott, Amanda F; McGwin, Gerald; Kline, Lanning B; Owsley, Cynthia


    To examine the rate of vision impairment and the relationship between vision impairment, cognitive impairment, and chronic comorbid conditions in residents of federally subsidized senior housing facilities. Cross-sectional, observational study. Vision screening events were held at 14 subsidized senior housing facilities in Jefferson County, Alabama for residents aged 60 years and older. Visual function (distance vision, near vision, and contrast sensitivity) measured with habitual correction if worn, cognitive status, and chronic comorbid conditions (hypertension, heart problems, circulation problems, and diabetes) were assessed. A total of 238 residents participated in the vision screenings. Most residents (75%) were African American. Vision impairment was common, with 40% of participants failing the distance acuity screening and 58% failing the near acuity screening; failure was defined as vision worse than 20/40 in either eye. Additionally, 65% failed the contrast sensitivity screening. A total of 30.6% of seniors had cognitive impairment. Regarding comorbid chronic conditions, 31% had circulation problems, 39% had diabetes, 41% had heart problems, and 76% had hypertension (59% had 2 or more of these). Visual acuity differed significantly between cognitive status groups and with the presence of heart and circulation problems. This study is among the first to provide information about vision impairment in this socioeconomically disadvantaged group of older adults. Vision impairment was common. Cognitive impairment and comorbid chronic conditions accounted for a small to moderate percentage of the variance in distance vision, near vision, and contrast sensitivity. Future studies should focus on strategies to facilitate access to eye care in this vulnerable population. © The Author 2015. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e-mail:

  6. 24 CFR 983.54 - Prohibition of assistance for units in subsidized housing. (United States)


    ..., DEPARTMENT OF HOUSING AND URBAN DEVELOPMENT PROJECT-BASED VOUCHER (PBV) PROGRAM Selection of PBV Owner... PBV assistance to units in any of the following types of subsidized housing: (a) A public housing... operating costs of the housing; (e) A unit subsidized with Section 236 rental assistance payments (12 U.S.C...

  7. Compaction and subsidence of the Groningen gas field in the Netherlands

    NARCIS (Netherlands)

    Thienen-Visser, K. van; Pruiksma, J.P.; Breunese, J.N.


    The Groningen gas field in the Netherlands is Europe’s largest gas field. It has been produced since 1963 and production is expected to continue until 2080. The pressure decline in the field causes compaction in the reservoir which is observed as subsidence at the surface. Measured subsidence is

  8. Subsidence of SB Charité total disc replacement and the role of undersizing. (United States)

    Punt, Ilona; van Rijsbergen, Marc; van Rietbergen, Bert; Ito, Keita; van Rhijn, Lodewijk; van Ooij, André; Willems, Paul


    A possible complication after total disc replacement (TDR) is subsidence, presumably caused by asymmetric implantation, implant undersizing or reduced bone quality. This study aims to quantify the degree of subsidence of an SB Charité TDR, and investigate whether undersizing is related to subsidence. A custom developed software package (Mathworks) reconstructed 3D bone-implant geometry. A threshold for subsidence was determined by comparing penetrated bone volume (PBV) and rotation angles. Inter- and intra-observer reproducibilities were calculated. Subsidence was correlated to undersizing. High inter- and intra-observer correlation coefficients were found for the method (R > 0.92). Subsidence was quantified as PBV 700 mm(3) combined with a rotation angle >7.5°. A reduced risk of subsidence was correlated to >60 and >62 % of the bony endplate covered by the TDR endplate for L4 and L5, respectively. A reproducible method to determine undersizing was developed. Thresholds were determined related to a reduced risk of subsidence.


    Directory of Open Access Journals (Sweden)

    Fahrudin Fahrudin


    Full Text Available Semarang city has experienced of the land subsidence that be caused by intake groundwater in confined aquiferabundant. The land subsidence happened during range of time 20 years, it’s critical boundary so that result theenvironmental damage. Hence needed a study of cause of the land subsidence. This study aim to know theposition of piezometric surface and also explain the mechanism hydrogeology when happened the landsubsidence. The study of spreading aquifer has been done by the analysis of secondary data which is in the formof drilling log data, piezometric surface and soil mechanics test obtained from PLG (Environmental Center ofGeology Bandung. Later then, between the land subsidence and piezometric surface be overlay becamezonation. From the data made a analysis of cause of the land subsidence. This aquifer has the land subsidence.The land subsidence explainable with the experienced phenomenon fact for example degradation of piezometricsurface at confined aquifer and process of hydrocompaction. That process influenced by two factors that areassess the pore number (e and specific gravity (Gs. The degradation of piezometric surface formed the trapezeof water table until 20 m from sea level with the mean 0.7 - 1.1 m/year. Hydrocompaction cause the degradationof number of mean pore 0.145 - 0.5 and specific gravity 0.009 - 0.073 . The degradation of piezometric surfaceand process the hydrocompaction cause the fast of land subsidence around 0.5 - 1.75 cm/year.

  10. Fighting the ignorance : The response to land subsidence by public authorities and land users in Indonesia

    NARCIS (Netherlands)

    Saputra, E.; Hartmann, T.; Zoomers, E.B.; Spit, T.J.M.


    Land subsidence can have a considerable impact on the socio-economic viability of areas. In urban areas, land subsidence tends to damage buildings and infrastructures gradually, while in rural peat land it slowly destroys vegetation. The damages will worsen since climate change has further

  11. Subsidence of organic dredged sediments in an upland deposit in Wormer- en Jisperveld

    NARCIS (Netherlands)

    Oliveira, Bruna R.F.; Smit, Martijn P.J.; Veld, Harry; Paassen, van Leon A.; Rijnaarts, Huub H.M.; Grotenhuis, Tim


    Land subsidence in low-lying peatlands can be caused by shrinkage and organic matter oxidation. When these areas have networks of ditches and canals for drainage purposes, the sediments that accumulate in the waterways can be used to reverse the process of land subsidence. The objective of this

  12. [Research on monitoring land subsidence in Beijing plain area using PS-InSAR technology]. (United States)

    Gu, Zhao-Qin; Gong, Hui-Li; Zhang, You-Quan; Lu, Xue-Hui; Wang, Sa; Wang, Rong; Liu, Huan-Huan


    In the present paper, the authors use permanent scatterers synthetic aperture radar interferometry (PS-InSAR) technique and 29 acquisitions by Envisat during 2003 to 2009 to monitor and analyze the spatial-temporal distribution and mechanism characterize of land subsidence in Beijing plain area. The results show that subsidence bowls have been bounded together in Beijing plain area, which covers Chaoyang, Changping, Shunyi and Tongzhou area, and the range of subsidence has an eastward trend. The most serious regional subsidence is mainly distributed by the quaternary depression in Beijing plain area. PS-Insar results also show a new subsidence bowl in Pinggu. What's more, the spatial and temporal distribution of deformation is controlled mainly by faults, such as Liangxiang-Shunyi fault, Huangzhuang-Gaoliying fault, and Nankou-Sunhe fault. The subsidence and level of groundwater in study area shows a good correlation, and the subsidence shows seasonal ups trend during November to March and seasonal downs trend during March to June along with changes in groundwater levels. The contribution of land subsidence is also influenced by stress-strain behavior of aquitards. The compaction of aquitards shows an elastic, plastic, viscoelastic pattern.

  13. Time-varying land subsidence detected by radar altimetry: California, Taiwan and north China. (United States)

    Hwang, Cheinway; Yang, Yuande; Kao, Ricky; Han, Jiancheng; Shum, C K; Galloway, Devin L; Sneed, Michelle; Hung, Wei-Chia; Cheng, Yung-Sheng; Li, Fei


    Contemporary applications of radar altimetry include sea-level rise, ocean circulation, marine gravity, and icesheet elevation change. Unlike InSAR and GNSS, which are widely used to map surface deformation, altimetry is neither reliant on highly temporally-correlated ground features nor as limited by the available spatial coverage, and can provide long-term temporal subsidence monitoring capability. Here we use multi-mission radar altimetry with an approximately 23 year data-span to quantify land subsidence in cropland areas. Subsidence rates from TOPEX/POSEIDON, JASON-1, ENVISAT, and JASON-2 during 1992-2015 show time-varying trends with respect to displacement over time in California's San Joaquin Valley and central Taiwan, possibly related to changes in land use, climatic conditions (drought) and regulatory measures affecting groundwater use. Near Hanford, California, subsidence rates reach 18 cm yr(-1) with a cumulative subsidence of 206 cm, which potentially could adversely affect operations of the planned California High-Speed Rail. The maximum subsidence rate in central Taiwan is 8 cm yr(-1). Radar altimetry also reveals time-varying subsidence in the North China Plain consistent with the declines of groundwater storage and existing water infrastructure detected by the Gravity Recovery And Climate Experiment (GRACE) satellites, with rates reaching 20 cm yr(-1) and cumulative subsidence as much as 155 cm.

  14. Influence the condition land subsidence and groundwater impact of Jakarta coastal area (United States)

    Rahman, S.; Sumotarto, U.; Pramudito, H.


    Jakarta has been experiencing land subsidence for ten years due toerecting weight building and intensive extraction of groundwater for society drink water through ground water wells. Many groundwater extraction for drinkingwater has caused intensive scouring of land rock and further triggering land subsidence developed widely in coastal area of Jakarta. Measurement of the land subsidence has been performed by various experts and institutes. Between 1974 to 2010 subsidence has happened between 3 to 4.1 meters especially in Jakarta coastal area. Two major causes of the subsidence are identified. The first major cause is a result of erecting weight building such as hotels, appartments, and various human activities buildings. The second major cause is extracting ground water from aquifers bellow Jakarta land due to water deep wells down to the aquifer and traditional shallow water well of shallow or subsurface uncovered ground water. Weighter building and higher debit of water flow from deep water wells has fastened and deepened the land subsidence. Continuous measurement of land subsidence by means of geodetic as well as geophysical earth behaviour measurements need to be performed to monitor the rate, location as well as mapping of the land subsidence.

  15. Is There Deep-Seated Subsidence in the Houston-Galveston Area?

    Directory of Open Access Journals (Sweden)

    Jiangbo Yu


    Full Text Available Long-term continuous groundwater level and land subsidence monitoring in the Houston-Galveston area indicates that, during the past two decades (1993–2012, the groundwater head has been increasing and the overall land subsidence rate has been decreasing. Assuming that the hydraulic head in the aquifer will reach or exceed the preconsolidation level in the near future, will subsidence in the Houston-Galveston area eventually cease? The key to answer this question is to identify if there is deep-seated subsidence in this area. This study investigated the recent subsidence observed at different depths in the Houston-Galveston area. The subsidence was recorded by using 13 borehole extensometers and 76 GPS antennas. Four of the GPS antennas are mounted on the deep-anchored inner pipes of borehole extensometers. We conclude that recent subsidence (1993–2012 in the Houston-Galveston area was dominated by the compaction of sediments within 600 m below the land surface. Depending on the location of specific sites, the compaction occurred within the Chicot aquifer and part or all of the Evangeline aquifer. No measurable compaction was observed within the Jasper aquifer or within deeper strata. Deep-seated subsidence is not likely occurring in the Houston-Galveston area.

  16. Impacts of 25 years of groundwater extraction on subsidence in the Mekong delta, Vietnam

    NARCIS (Netherlands)

    Minderhoud, P.S.J.; Erkens, G.; van Pham, H.; Bui, Vuong Tran; Erban, Laura; Kooi, Henk; Stouthamer, E.


    Many major river deltas in the world are subsiding and consequently become increasingly vulnerable to flooding and storm surges, salinization and permanent inundation. For the Mekong Delta, annual subsidence rates up to several centimetres have been reported. Excessive groundwater extraction is

  17. Threat of land subsidence in and around Kolkata City and East ...

    Indian Academy of Sciences (India)

    Kolkata; East Kolkata Wetlands; groundwater; land subsidence; groundwater potential; sustainable development. J. Earth Syst. Sci. 120, No. 3, June 2011, pp. 435– ... Location subsidence (m). Period. Source of information. Municipal and. Su-Xi-Chang, China. 0.018. 1984–2005. Zhang et al (2010) industrial. Mashhad, Iran.

  18. Impact of subsidence on clinical outcomes and radiographic fusion rates in anterior cervical discectomy and fusion: a systematic review. (United States)

    Karikari, Isaac O; Jain, Deeptee; Owens, Timothy Ryan; Gottfried, Oren; Hodges, Tiffany R; Nimjee, Shahid M; Bagley, Carlos A


    Systematic review. To provide a systematic review of published literature on the impact of subsidence on clinical outcomes and radiographic fusion rates after anterior cervical discectomy and fusion with plates or without plates. Subsidence of interbody implants is common after anterior cervical spine fusions. The impact of subsidence on fusion rates and clinical outcomes is unknown. Systematic literature review on published articles on anterior cervical discectomy and fusion, which objectively measured graft subsidence, radiographic fusion rates, and clinical outcomes between April 1966 and December 2010. A total of 35 articles that measured subsidence and provided fusion rates and/or clinical outcomes were selected for inclusion. The mean subsidence rate ranged from 19.3% to 42.5%. The rate of subsidence based on the type of implant ranged from 22.8% to 35.9%. The incidence of subsidence was not impacted by the type of implant (P=0.98). The overall fusion rate of the combined studies was 92.8% and was not impacted by subsidence irrespective of subsidence definition or the measurement technique used (P=0.19). Clinical outcomes were evaluated in 27 of 35 studies with all studies reporting an improvement in patient outcomes postoperatively. Subsidence irrespective of the measurement technique or definition does not appear to have an impact on successful fusion and/or clinical outcomes. A validated definition and standard measurement technique for subsidence is needed to determine the actual incidence of subsidence and its impact on radiographic and clinical outcomes.

  19. Land subsidence threats and its management in the North Coast of Java (United States)

    Sarah, D.; Soebowo, E.


    Cities on the north coast of Java such as Jakarta, Semarang, Pekalongan, and Surabaya are vulnerable to environmental pressures such as sea level change and land subsidence. Land subsidence can be caused by natural and anthropogenic processes. Geologically, the north coastal plain of Java consists of unconsolidated Holocene alluvial deposit. The recent alluvial deposit is prone to compaction, and further aggravated by anthropogenic forces such as groundwater extraction and land development. Understanding the complex interaction of natural and manmade factors is essential to establish mitigation strategy. Although the impacts of land subsidence are widely felt, many do not realize that land subsidence is taking place. This paper presents a brief review of the land subsidence threats in the North coast of Java and proposes a recommendation for suitable management response.

  20. Investigation of the land subsidence and its consequences of large groundwater withdrawal in Rafsanjan, Iran. (United States)

    Solaimani, Karim; Mortazavi, S Mostafa


    Land subsidence is a phenomenon that involves the lowering or settling of the earth's surface due to various factors. The land subsidence due to groundwater withdrawal over the world has been seen in many areas. A decrease in ground water level would cause an increase in effective stresses at clay layers which results consolidation of lower layers. Since about 1980, it has been proven that Kerman Province subsidence in Iran is due to extensive ground water withdrawal. Overdraft of groundwater, an increasing of about 6 times since 1969 to 1999, has caused a decline of about 28 m in groundwater level. The rate of subsidence recently is about 5-15 cm. for decline of about one meter in groundwater level. In Rafsanjan area, many problems such as increase in the salinity of groundwater, land subsidence and consequently earth fissures and cracks in buildings are caused by groundwater withdrawal.

  1. The cytoplasmic cage domain of the mechanosensitive channel MscS is a sensor of macromolecular crowding. (United States)

    Rowe, Ian; Anishkin, Andriy; Kamaraju, Kishore; Yoshimura, Kenjiro; Sukharev, Sergei


    and crowding pressure. The cage, therefore, provides feedback on the increasing crowding that disengages the gate and prevents excessive draining and condensation of the cytoplasm. We discuss the structural mechanics of cells surrounded by an elastic cell wall where this MscS-specific feedback mechanism may be necessary.

  2. Contemporaneous ring fault activity and surface deformation at subsiding calderas studied using analogue experiments (United States)

    Liu, Yuan-Kai; Ruch, Joël; Vasyura-Bathke, Hannes; Jónsson, Sigurjón


    Ground deformation analyses of several subsiding calderas have shown complex and overlapping deformation signals, with a broad deflation signal that affects the entire volcanic edifice and localized subsidence focused within the caldera. However, the relation between deep processes at subsiding calderas, including magmatic sources and faulting, and the observed surface deformation is still debated. Several recent examples of subsiding calderas in the Galápagos archipelago and at the Axial seamount in the Pacific Ocean indicate that ring fault activity plays an important role not only during caldera collapse, but also during initial stages of caldera subsidence. Nevertheless, ring fault activity has rarely been integrated into numerical models of subsiding calderas. Here we report on sandbox analogue experiments that we use to study the processes involved from an initial subsidence to a later collapse of calderas. The apparatus is composed of a subsiding half piston section connected to the bottom of a glass box and driven by a motor to control its subsidence. We analyze at the same time during the subsidence the 3D displacement at the model surface with a laser scanner and the 2D ring fault evolution on the side of the model (cross-section) with a side-view digital camera. We further use PIVLab, a time-resolved digital image correlation software tool, to extract strain and velocity fields at both the surface and in cross-section. This setup allows to track processes acting at depth and assess their relative importance as the collapse evolves. We further compare our results with the examples observed in nature as well as with numerical models that integrate ring faults.

  3. Graft subsidence as a predictor of revision surgery following stand-alone lateral lumbar interbody fusion. (United States)

    Tempel, Zachary J; McDowell, Michael M; Panczykowski, David M; Gandhoke, Gurpreet S; Hamilton, D Kojo; Okonkwo, David O; Kanter, Adam S


    OBJECTIVE Lateral lumbar interbody fusion (LLIF) is a less invasive surgical option commonly used for a variety of spinal conditions, including in high-risk patient populations. LLIF is often performed as a stand-alone procedure, and may be complicated by graft subsidence, the clinical ramifications of which remain unclear. The aim of this study was to characterize further the sequelae of graft subsidence following stand-alone LLIF. METHODS A retrospective review of prospectively collected data was conducted on consecutive patients who underwent stand-alone LLIF between July 2008 and June 2015; 297 patients (623 levels) met inclusion criteria. Imaging studies were examined to grade graft subsidence according to Marchi criteria, and compared between those who required revision surgery and those who did not. Additional variables recorded included levels fused, DEXA (dual-energy x-ray absorptiometry) T-score, body mass index, and routine demographic information. The data were analyzed using the Student t-test, chi-square analysis, and logistic regression analysis to identify potential confounding factors. RESULTS Of 297 patients, 34 (11.4%) had radiographic evidence of subsidence and 18 (6.1%) required revision surgery. The median subsidence grade for patients requiring revision surgery was 2.5, compared with 1 for those who did not. Chi-square analysis revealed a significantly higher incidence of revision surgery in patients with high-grade subsidence compared with those with low-grade subsidence. Seven of 18 patients (38.9%) requiring revision surgery suffered a vertebral body fracture. High-grade subsidence was a significant predictor of the need for revision surgery (p subsidence following stand-alone LLIF required revision surgery. When evaluating patients for LLIF, supplemental instrumentation should be considered during the index surgery in patients with a significant risk of graft subsidence.

  4. The Effect of Uncinate Process Resection on Subsidence Following Anterior Cervical Discectomy and Fusion. (United States)

    Lee, Su Hun; Lee, Jun Seok; Sung, Soon Ki; Son, Dong Wuk; Lee, Sang Weon; Song, Geun Sung


    Subsidence is a frequent complication of anterior cervical discectomy and fusion. Postoperative segmental micro-motion, thought to be a causative factor of subsidence, has been speculated to increase with uncinate process resection area (UPR). To evaluate the effect of UPR on micro-motion, we designed a method to measure UPR area based on pre- and postoperative computed tomography images and analyzed the relationship between UPR and subsidence as a proxy of micro-motion. We retrospectively collected clinical and radiological data from January 2011 to June 2016. A total of 38 patients (53 segments) were included. All procedures included bilateral UPR and anterior plate fixation. UPR area was evaluated with reformatted coronal computer tomography images. To reduce level-related bias, we converted UPR area to the proportion of UPR to the pre-operative UP area (pUPR). Subsidence occurred in 18 segments (34%) and positively correlated with right-side pUPR, left-side pUPR, and the sum of bilateral pUPR (sum pUPR) (R=0.310, 301, 364; p=0.024, 0.029, 0.007, respectively). Multiple linear regression analysis revealed that subsidence could be estimated with the following formula: subsidence=1.522+2.7×sum pUPR (R2=0.133, p=0.007). Receiver-operating characteristic analysis determined that sum pUPR≥0.38 could serve as a threshold for significantly increased risk of subsidence (p=0.005, area under curve=0.737, sensitivity=94%, specificity=51%). This threshold was confirmed by logistic regression analysis for subsidence (p=0.009, odds ratio=8.471). The UPR measurement method confirmed that UPR was correlated with subsidence. Particularly when the sum of pUPR is ≥38%, the possibility of subsidence increased.

  5. Plastic cages to protect Douglas-fir seedlings from animal damage in western Oregon. (United States)

    Glen C. Crouch


    Effects of plastic mesh cages designed to protect Douglas-fir seedlings from animals were evaluated in western Oregon. In two tests over 5-year periods, caging increased survival by 0 and 13 percent and increased height growth by 0.8 and 1.2 feet compared with uncaged trees. Benefits from caging might have been greater if damage had been more prevalent during the tests...

  6. Standard methods for maintaining adult Apis mellifera in cages under in vitro laboratory conditions


    Williams, Geoffrey R.; Alaux, Cedric; Costa, Cecilia; Csaki, Tamas; Doublet, Vincent; Eisenhardt, Dorothea; Fries, Ingemar; Kuhn, Rolf; McMahon, Dino P.; Medrzycki, Piotr; Murray, Tomas E.; Natsopoulou, Myrsini E.; Neumann, Peter; Oliver, Randy; Paxton, Robert J.


    Adult honey bees are maintained in vitro in laboratory cages for a variety of purposes. For example, researchers may wish to perform experiments on honey bees caged individually or in groups to study aspects of parasitology, toxicology, or physiology under highly controlled conditions, or they may cage whole frames to obtain newly emerged workers of known age cohorts. Regardless of purpose, researchers must manage a number of variables, ranging from selection of study subjects (e.g. honey bee...

  7. Standard methods for maintaining adult Apis mellifera in cages under in vitro laboratory conditions


    Williams, G.R.; Alaux, C.; Costa, C.; Csaki, C.; Steen, van der, J.J.M.


    Adult honey bees are maintained in vitro in laboratory cages for a variety of purposes. For example, researchers may wish to perform experiments on honey bees caged individually or in groups to study aspects of parasitology, toxicology, or physiology under highly controlled conditions, or they may cage whole frames to obtain freshly emerged workers of known age cohorts. Regardless of purpose, researchers must manage a number of variables, ranging from selection of study subjects (e.g. honey b...

  8. Greenhouse Gas Emissions from Three Cage Layer Housing Systems

    Directory of Open Access Journals (Sweden)

    John Feddes


    Full Text Available Agriculture accounts for 10 to 12% of the World’s total greenhouse gas (GHG emissions. Manure management alone is responsible for 13% of GHG emissions from the agricultural sector. During the last decade, Québec’s egg production systems have shifted from deep-pit housing systems to manure belt housing systems. The objective of this study was to measure and compare carbon dioxide (CO2, methane (CH4 and nitrous oxide (N2O emissions from three different cage layer housing systems: a deep liquid manure pit and a manure belt with natural or forced air drying. Deep liquid manure pit housing systems consist of “A” frame layer cages located over a closed pit containing the hens’ droppings to which water is added to facilitate removal by pumping. Manure belt techniques imply that manure drops on a belt beneath each row of battery cages where it is either dried naturally or by forced air until it is removed. The experiment was replicated with 360 hens reared into twelve independent bench-scale rooms during eight weeks (19–27 weeks of age. The natural and forced air manure belt systems reduced CO2 (28.2 and 28.7 kg yr−1 hen−1, respectively, CH4 (25.3 and 27.7 g yr−1 hen−1, respectively and N2O (2.60 and 2.48 g yr−1 hen−1, respectively emissions by about 21, 16 and 9% in comparison with the deep-pit technique (36.0 kg CO2 yr−1 hen−1, 31.6 g CH4 yr−1 hen−1 and 2.78 g N2O yr−1 hen−1. The shift to manure belt systems needs to be encouraged since this housing system significantly decreases the production of GHG.

  9. Impact of rock salt creep law choice on subsidence calculations for hydrocarbon reservoirs overlain by evaporite caprocks

    NARCIS (Netherlands)

    Marketos, G.; Spiers, C.J.; Govers, R.


    Accurate forward modeling of surface subsidence above producing hydrocarbons reservoirs requires an understanding of the mechanisms determining how ground deformation and subsidence evolve. Here we focus entirely on rock salt, which overlies a large number of reservoirs worldwide, and specifically

  10. Assessing the long-term impact of subsidence and global climate change on emergency evacuation routes in coastal Louisiana. (United States)


    Subsidence forecast models for coastal Louisiana were developed to estimate the change in surface elevations of evacuation routes for the years 2015, 2025, 2050, and 2100. Geophysical and anthropogenic subsidence estimates were derived from on-going ...

  11. [Primary investigation of formation and genetic mechanism of land subsidence based on PS-InSAR technology in Beijing]. (United States)

    Lei, Kun-chao; Chen, Bei-bei; Jia, San-man; Wang, Shu-fang; Luo, Yong


    The present paper adopts permanent scatterer interferometric synthetic aperture radar(PS-InSAR) technique to obtain land subsidence information in Beijing plain area. Then, combined with the time series of meteorological data, groundwater dynamic monitoring data, interferometric data and geological structure data, the formation and evolution mechanism of land subsidence were revealed. The results show that (1) Beijing regional land subsidence characteristics are obvious, more land subsidence funnel areas are interconnected, the settlement is influenced by rainfall recharge and exhibits seasonal fluctuation characteristics; (2) The land subsidence center and groundwater drawdown funnel centre are not fully consistent, unconfined aquifer and shallow confined aquifer are the major contribution factors and have greater impact on the land subsidence; (3) Land subsidence mainly occurred in the clay layer with a thickness of 50-70 m; (4) Land subsidence caused by tectonic controls is significant and the deformation gradient is great on both sides of the fault.

  12. Preinjector for Linac 1, inside the Faraday cage

    CERN Multimedia


    For a description of the Linac 1 preinjector, please see first 7403070X. Here, the view is towards the upper level of the Faraday cage. Far to the right, a technician is peering through the service door. The huge box-shaped cubicle is the electronics platform, at 520 kV potential during operation. The "bull eye" at the left back sits at the top end of the accelerating column (see 7403081X) and houses the ion source with its electronics (see 7403083X). The SAMES generator, providing the 520 kV HV (7403074) sits on the floor and is not visible here.

  13. Sensitivity of BN nano-cages to caffeine and nicotine molecules (United States)

    Soltani, Alireza; Baei, Mohammad T.; Tazikeh Lemeski, E.; Shahini, Malihe


    Adsorption of caffeine and nicotine molecules over B12N12 and B16N16 nano-cages were investigated by using first-principles calculations to define whether BN nano-cages are applicable for filtering or sensing caffeine and nicotine molecules. The chemisorption energy of nicotine molecule on BN nano-cages is very stronger than caffeine molecule. Upon the adsorption of caffeine and nicotine molecules, the electronic properties of the BN nano-cages can be significantly changed, being too much sensitized on the caffeine and nicotine adsorptions.

  14. Evaluation of cage micro-environment of mice housed on various types of bedding materials (United States)

    Smith, E.; Stockwell, J.D.; Schweitzer, I.; Langley, S.H.; Smith, A.L.


    A variety of environmental factors can affect the outcomes of studies using laboratory rodents. One such factor is bedding. Several new bedding materials and processing methods have been introduced to the market in recent years, but there are few reports of their performance. In the studies reported here, we have assessed the cage micro-environment (in-cage ammonia levels, temperature, and humidity) of mice housed on various kinds of bedding and their combinations. We also compared results for bedding supplied as Nestpaks versus loose bedding. We studied C57BL/6J mice (commonly used) and NOD/LtJ mice (heavy soilers) that were maintained, except in one study, in static duplex cages. In general, we observed little effect of bedding type on in-cage temperature or humidity; however, there was considerable variation in ammonia concentrations. The lowest ammonia concentrations occurred in cages housing mice on hardwood bedding or a mixture of corncob and alpha cellulose. In one experiment comparing the micro-environments of NOD/LtJ male mice housed on woodpulp fiber bedding in static versus ventilated caging, we showed a statistically significant decrease in ammonia concentrations in ventilated cages. Therefore, our data show that bedding type affects the micro-environment in static cages and that effects may differ for ventilated cages, which are being used in vivaria with increasing frequency.

  15. Evaluation of cage micro-environment of mice housed on various types of bedding materials. (United States)

    Smith, Ellen; Stockwell, Jason D; Schweitzer, Isabelle; Langley, Stephen H; Smith, Abigail L


    A variety of environmental factors can affect the outcomes of studies using laboratory rodents. One such factor is bedding. Several new bedding materials and processing methods have been introduced to the market in recent years, but there are few reports of their performance. In the studies reported here, we have assessed the cage micro-environment (in-cage ammonia levels, temperature, and humidity) of mice housed on various kinds of bedding and their combinations. We also compared results for bedding supplied as Nestpaks versus loose bedding. We studied C57BL/6J mice (commonly used) and NOD/LtJ mice (heavy soilers) that were maintained, except in one study, in static duplex cages. In general, we observed little effect of bedding type on in-cage temperature or humidity; however, there was considerable variation in ammonia concentrations. The lowest ammonia concentrations occurred in cages housing mice on hardwood bedding or a mixture of corncob and alpha cellulose. In one experiment comparing the micro-environments of NOD/LtJ male mice housed on woodpulp fiber bedding in static versus ventilated caging, we showed a statistically significant decrease in ammonia concentrations in ventilated cages. Therefore, our data show that bedding type affects the micro-environment in static cages and that effects may differ for ventilated cages, which are being used in vivaria with increasing frequency. Copyright 2004 American Association for Laboratory Animal Science

  16. Manipulation of intracellular auxin in a single cell by light with esterase-resistant caged auxins. (United States)

    Kusaka, Naoyuki; Maisch, Jan; Nick, Peter; Hayashi, Ken-ichiro; Nozaki, Hiroshi


    Auxin, a plant hormone, is polar transported from its site of production. This auxin polar transport system establishes an auxin gradient in plant tissue that is necessary for proper plant development. Therefore, the spatial effect of the auxin gradient on plant development is highly important for the understanding of plant auxin responses. Herein we report the design, syntheses and biological properties of esterase-resistant caged auxins. The conventional caging group, 2-nitrobenzyl ester, was found to be enzymatically hydrolyzed in plant cells and released original auxin without photolysis. The esterase-resistant caging group, (2,5-dimethoxyphenyl)(2-nitrobenzyl) ester, (DMPNB) was designed to improve the stability of caged auxins. Three auxins, indole 3-acetic acid, naphthalene 1-acetic acid and 2,4-dichlorophenoxy acetic acid were caged with the DMPNB caging group. DMPNB-caged auxins were inactive within a plant cell until photolysis, but they release auxins with photoirradiation to activate auxin-responsive gene expression. We demonstrated spatial and temporal control of intracellular auxin levels with photoirradiation by using this caged auxin system and were able to photocontrol the physiological auxin response in Arabidopsis plants. Additionally, the photoirradiation of DMPNB-caged auxin within a single cell can manipulate the intracellular auxin level and triggers auxin response.

  17. REINVENTING THE WHEEL: Comparison of Two Wheel Cage Styles for Assessing Mouse Voluntary Running Activity. (United States)

    Seward, Tanya; Harfmann, Brianna D; Esser, Karyn A; Schroder, Elizabeth A


    Voluntary wheel cage assessment of mouse activity is commonly employed in exercise and behavioral research. Currently, no standardization for wheel cages exists resulting in an inability to compare results among data from different labs. The purpose of this study was to determine whether the distance run or average speed data differs depending on the use of two commonly used commercially available wheel cage systems. Two different wheel cages with structurally similar but functionally different wheels (electromechanical switch vs magnetic switch) were compared side-by-side to measure wheel running data differences. Other variables, including enrichment and cage location, were also tested to assess potential impacts on the running wheel data. We found that cages with the electromechanical switch had greater inherent wheel resistance and consistently led to higher greater running distance/day and higher average running speed. Mice rapidly, within 1-2 days, adapted their running behavior to the type of experimental switch used suggesting these running differences are more behavioral than due to intrinsic musculoskeletal, cardiovascular or metabolic limits. The presence of enrichment or location of the cage had no detectable impact on voluntary wheel running. These results demonstrate that mice run differing amounts depending on the type of cage and switch mechanism used and thus, investigators need to report wheel cage type/ wheel resistance and use caution when interpreting distance/speed run across studies.

  18. A stochastic frontier analysis of technical efficiency of fish cage culture in Peninsular Malaysia. (United States)

    Islam, Gazi Md Nurul; Tai, Shzee Yew; Kusairi, Mohd Noh


    Cage culture plays an important role in achieving higher output and generating more export earnings in Malaysia. However, the cost of fingerlings, feed and labour have increased substantially for cage culture in the coastal areas in Peninsular Malaysia. This paper uses farm level data gathered from Manjung, Perak and Kota Tinggi, Johor to investigate the technical efficiency of brackish water fish cage culture using the stochastic frontier approach. The technical efficiency was estimated and specifically the factors affecting technical inefficiencies of fish cage culture system in Malaysia was investigated. On average, 37 percent of the sampled fish cage farms are technically efficient. The results suggest very high degrees of technical inefficiency exist among the cage culturists. This implies that great potential exists to increase fish production through improved efficiency in cage culture management in Peninsular Malaysia. The results indicate that farmers obtained grouper fingerlings from other neighboring countries due to scarcity of fingerlings from wild sources. The cost of feeding for grouper (Epinephelus fuscoguttatus) requires relatively higher costs compared to seabass (Lates calcarifer) production in cage farms in the study areas. Initiatives to undertake extension programmes at the farm level are needed to help cage culturists in utilizing their resources more efficiently in order to substantially enhance their fish production.

  19. A high-precision instrument for analyzing nonlinear dynamic behavior of bearing cage

    International Nuclear Information System (INIS)

    Yang, Z.; Yu, T.; Chen, H.; Li, B.


    The high-precision ball bearing is fundamental to the performance of complex mechanical systems. As the speed increases, the cage behavior becomes a key factor in influencing the bearing performance, especially life and reliability. This paper develops a high-precision instrument for analyzing nonlinear dynamic behavior of the bearing cage. The trajectory of the rotational center and non-repetitive run-out (NRRO) of the cage are used to evaluate the instability of cage motion. This instrument applied an aerostatic spindle to support and spin test the bearing to decrease the influence of system error. Then, a high-speed camera is used to capture images when the bearing works at high speeds. A 3D trajectory tracking software TEMA Motion is used to track the spot which marked the cage surface. Finally, by developing the MATLAB program, a Lissajous’ figure was used to evaluate the nonlinear dynamic behavior of the cage with different speeds. The trajectory of rotational center and NRRO of the cage with various speeds are analyzed. The results can be used to predict the initial failure and optimize cage structural parameters. In addition, the repeatability precision of instrument is also validated. In the future, the motorized spindle will be applied to increase testing speed and image processing algorithms will be developed to analyze the trajectory of the cage.

  20. Determining basic parameters of shafts with cage hoisting systems in mines with steep seams

    Energy Technology Data Exchange (ETDEWEB)

    Durov, E.M.


    This paper analyzes problems associated with increasing depth of mine shafts in operating coal mines. Schemes of shaft excavation in mines with steep coal seams are analyzed. Removal of mine rock and the ground surface by existing mine shafts is most economical in most cases. Yuzhgiproshakht has investigated a number of hoisting schemes during mine shaft excavation in order to select the optimum shaft diameter which permits shaft reconstruction and deepening to be optimized. The following conditions are analyzed: coal output of a coal mine ranges from 0.9 megatons (Mt) to 1.8 Mt/year, mining depth ranges from 600 m to 1600 m (with intermediary depth of 800, 1000, 1200 and 1400 m also considered). Separate hoisting of coal and rock waste is used. Shaft sinking rate ranges from 10 to 50 m/month. The following hoisting schemes are analyzed: two independent systems which consist of a cage with counterweight, three systems of a cage with counterweight, double cage system and a cage with counterweight. Hoisting schemes are shown in 9 diagrams. Investigations show that a 7 to 8 m diameter of mine shafts is most economic. In mine shafts 7 m in diameter equipped with two cages with counterweights one of the cages is removed to form a free space for the hoisting bucket. In the 8 m shaft equipped with a double cage system and a cage with counterweight the cage with counterweight is removed to form a free place for the hoisting bucket used during shaft excavation.

  1. Subsidence due to peat compaction and oxidation in built-up deltas (United States)

    van Asselen, Sanneke; Erkens, Gilles; Stouthamer, Esther; Hefting, Mariet


    Deltas are often densely populated, and are predicted to face continued population growth and urbanization. At the same time, deltas are threatened by relative sea-level rise due to the combined effect of land subsidence and global sea-level rise. Many deltaic sequences contain large amounts of peat. In such organo-clastic deltas, peat compaction and oxidation are important contributors to total subsidence. Especially in built-up areas, (differential) subsidence and associated increased flood risk, result in high costs related to damage to buildings and infrastructure. Yet, subsidence due to peat compaction and oxidation in built-up deltaic areas has not been given sufficient attention. These processes have mostly been studied separately, in rural or pristine areas. To develop tailor-made subsidence management strategies for built-up areas in organo-clastic deltas, a thorough understanding of peat compaction and oxidation, and their spatial and temporal variability, is needed. Therefore, we investigated the relative contribution of both peat compaction and oxidation to subsidence in three built-up areas in the Rhine-Meuse delta, The Netherlands. We used (1) borehole data to construct lithological cross sections of the Holocene sequence, (2) dry bulk density and organic-matter content measurements to assess the degree of compaction, and (3) respiration measurements to determine the oxidation potential. We assessed subsidence due to peat compaction or oxidation of up to 2 meters over the last 1000 years, and subsidence rates of up to 16 cm·yr-1. The amount and rate of subsidence due to peat compaction and oxidation, and the relative contribution of both processes, is however highly variable in time and space, depending on the Holocene sequence composition, loading conditions, and groundwater-table lowering. For example, subsidence in a sequence with a heavily loaded peat layer will have been mostly caused by peat compaction, while subsidence in a sequence with a

  2. Rapid groundwater-related land subsidence in Yemen observed by multi-temporal InSAR

    KAUST Repository

    Abdullin, Ayrat


    Several basins in Yemen are suffering from a rapid drawdown of groundwater, which is the most important water source for agricultural irrigation, industry and domestic use. However, detailed geodetic measurements in the region have been lacking and the extent and magnitude of groundwater-related land subsidence has been poorly known. We used 13 ascending ALOS and 15 descending Envisat images to study land subsidence of several basins in Yemen, with a special focus on the Sana\\'a and Mabar basins. From multitemporal synthetic aperture radar interferometric analysis (persistent scatterers (PS) and small baseline subsets (SBAS)) we examined the spatio-temporal behavior of the subsidence induced by depletion of groundwater aquifer systems from November 2003 to February 2011. In the interferometric data processing, we carefully chose interferogram pairs to minimize spatial and temporal decorrelation, because of high subsidence rates and the type of land cover. Our results show that the spatial pattern of subsidence remained quite stable during the observation period in both the Sana\\'a and Mabar basins. In the Sana\\'a basin, the maximum subsidence rate exceeded 14 cm/year in the radar line-of-sight (LOS) direction between 2003 and 2008 in an agricultural area just north of Sana\\'a city, where water wells have been drying up according to the well data. The subsidence rate was lower in the urban areas, or approximately 1 cm/year, exhibiting annual variations. The main subsidence was found in the center and southern parts of the city, while deformation in the northern part is less obvious. For the Mabar basin, the subsidence rate exceeded 30 cm/year in the agricultural area north of the town of Mabar during 2007 - 2011. The southern part of the Mabar basin also experienced high subsidence rates, although somewhat lower than to the north. Excessive water pumping is the main cause of the ground subsidence and it has already led to extensive ground fracturing at the edge

  3. Rapid groundwater-related land subsidence in Yemen observed by multi-temporal InSAR (United States)

    Abdullin, Ayrat; Xu, Wenbin; Kosmicki, Maximillian; Jonsson, Sigurjon


    Several basins in Yemen are suffering from a rapid drawdown of groundwater, which is the most important water source for agricultural irrigation, industry and domestic use. However, detailed geodetic measurements in the region have been lacking and the extent and magnitude of groundwater-related land subsidence has been poorly known. We used 13 ascending ALOS and 15 descending Envisat images to study land subsidence of several basins in Yemen, with a special focus on the Sana'a and Mabar basins. From multitemporal synthetic aperture radar interferometric analysis (persistent scatterers (PS) and small baseline subsets (SBAS)) we examined the spatio-temporal behavior of the subsidence induced by depletion of groundwater aquifer systems from November 2003 to February 2011. In the interferometric data processing, we carefully chose interferogram pairs to minimize spatial and temporal decorrelation, because of high subsidence rates and the type of land cover. Our results show that the spatial pattern of subsidence remained quite stable during the observation period in both the Sana'a and Mabar basins. In the Sana'a basin, the maximum subsidence rate exceeded 14 cm/year in the radar line-of-sight (LOS) direction between 2003 and 2008 in an agricultural area just north of Sana'a city, where water wells have been drying up according to the well data. The subsidence rate was lower in the urban areas, or approximately 1 cm/year, exhibiting annual variations. The main subsidence was found in the center and southern parts of the city, while deformation in the northern part is less obvious. For the Mabar basin, the subsidence rate exceeded 30 cm/year in the agricultural area north of the town of Mabar during 2007 - 2011. The southern part of the Mabar basin also experienced high subsidence rates, although somewhat lower than to the north. Excessive water pumping is the main cause of the ground subsidence and it has already led to extensive ground fracturing at the edge of some

  4. Incidence and impact of implant subsidence after stand-alone lateral lumbar interbody fusion. (United States)

    Bocahut, N; Audureau, E; Poignard, A; Delambre, J; Queinnec, S; Flouzat Lachaniette, C-H; Allain, J


    Few data are available on the occurrence after stand-alone lateral lumbar interbody fusion (LLIF) of implant subsidence, whose definition and incidence vary across studies. The primary objective of this work was to determine the incidence of subsidence 1 year postoperatively, using an original measurement method, whose validity was first assessed. The secondary objective was to assess the clinical impact of subsidence. Implant subsidence after stand-alone LLIF is a common complication that can adversely affect clinical outcomes. Of 69 included patients who underwent stand-alone LLIF, 67 (97%) were re-evaluated at least 1 year later. Furthermore, 63 (91%) patients had two available computed tomography (CT) scans for assessing subsidence, one performed immediately after surgery and the other 1 year later. Reproducibility of the original measurement method was assessed in a preliminary study. Subsidence was defined as at least 4mm loss of fused space height. The incidence of subsidence was 32% (20 patients). Subsidence was global in 7 (11%) patients and partial in 13 (21%) patients. Mean loss of height was 5.5±1.5mm. Subsidence predominated anteriorly in 50% of cases. The lordotic curvature of the fused segment was altered in 50% of patients, by a mean of 8°±3°. Fusion was achieved in 67/69 (97%) patients. The Oswestry score and visual analogue scale scores for low-back and nerve-root pain were significantly improved after 1 year in the overall population and in the groups with and without subsidence. Reproducibility of our measurement method was found to be excellent. Subsidence was common but without significant clinical effects after 1 year. Nevertheless, subsidence can be associated with pain and can result in loss of lumbar lordosis, which is a potential risk factor for degenerative disease of the adjacent segments. A score for predicting the risk of subsidence will now be developed by our group as a tool for improving patient selection to stand-alone LLIF

  5. Estimation of geomechanical subsidence at Hanford low-level solid waste disposal sites: Empirical analysis based on geological engineering

    International Nuclear Information System (INIS)

    Phillips, S.J.; Gilbert, T.W.


    Geotechnical/geomechanical subsidence is of concern at several Hanford Site low-level waste disposal locations. Subsidence may result in long-term maintenance, or perhaps, loss of confinement of contaminants within the boundaries of specific disposal sites. A preliminary method to estimate the magnitude of subsidence is reported. Additionally, graphic relationships are reported that permit estimation of depth and volume of subsidence ground surface features

  6. Clinical and radiological outcomes after stand-alone ALIF for single L5-S1 degenerative discopathy using a PEEK cage filled with hydroxyapatite nanoparticles without bone graft. (United States)

    Norotte, Gilles; Barrios, Carlos


    Recent improvements in cage designs with integral fixation and screw attachments have made stand-alone ALIF a viable option with several possible advantages. The aim of this study was to confirm the efficacy and safety of a PEEK cage filled with hydroxyapatite nanoparticles without adding a bone graft for stand-alone ALIF in the treatment of L5-S1 isolated degenerative disc discopathy (DDD). Sixty-five patients who required surgery for DDD were evaluated. Clinical outcome evaluations included back and leg pain (VAS), disability (Oswestry Disability Index), and patient satisfaction (Macnab's criteria). Radiological outcomes include the assessment of disc height, the L5-S1 intervertebral disc angle, and anterior intervertebral fusion through standard and functional sagittal X-rays of the lumbar spine. Clinical and radiological measurements were assessed 2, 6, 12, and 24 months after surgery. Clinical outcomes improved progressively and stabilized from 12- to 24-month follow-up. Final postoperative ODI scores showed a notable improvement (95%CI = 36.1-48.9 points; p < .001). Similarly, 24-month postoperative VAS scores revealed a significant decrease in pain (95%CI = 5.4-6.2; p < .001). The fusion rate was 95.4%. Anterior disc height was restored from 4.1 ± 3.2 mm at baseline to 9.5 ± 1.6 mm in the immediate postoperative period (p < .001). A small collapse (17.9%) of the disc height was detected from the 2- and 24-month follow-ups. Cage subsidence (more than 3 mm collapse) was detected in 4 cases (6.2%) and was related to cage size (more than 11 mm height; P < .05). There were no serious bone substitute-related adverse events and no revision surgeries. Stand-alone anterior lumbar interbody fusion using hydroxyapatite nanoparticles without an autologous bone graft is an effective and safe treatment option for L5-S1 degenerative pathology. Clinical outcomes were very satisfactory with a high fusion rate. Copyright © 2018

  7. Regional subsidence history and 3D visualization with MATLAB of the Vienna Basin, central Europe (United States)

    Lee, E.; Novotny, J.; Wagreich, M.


    This study reconstructed the subsidence history by the backstripping and 3D visualization techniques, to understand tectonic evolution of the Neogene Vienna Basin. The backstripping removes the compaction effect of sediment loading and quantifies the tectonic subsidence. The amount of decompaction was calculated by porosity-depth relationships evaluated from seismic velocity data acquired from two boreholes. About 100 wells have been investigated to quantify the subsidence history of the Vienna Basin. The wells have been sorted into 10 groups; N1-4 in the northern part, C1-4 in the central part and L1-2 in the northernmost and easternmost parts, based on their position within the same block bordered by major faults. To visualize 3D subsidence maps, the wells were arranged to a set of 3D points based on their map location (x, y) and depths (z1, z2, z3 ...). The division of the stratigraphic column and age range was arranged based on the Central Paratethys regional Stages. In this study, MATLAB, a numerical computing environment, was used to calculate the TPS interpolation function. The Thin-Plate Spline (TPS) can be employed to reconstruct a smooth surface from a set of 3D points. The basic physical model of the TPS is based on the bending behavior of a thin metal sheet that is constrained only by a sparse set of fixed points. In the Lower Miocene, 3D subsidence maps show strong evidence that the pre-Neogene basement of the Vienna Basin was subsiding along borders of the Alpine-Carpathian nappes. This subsidence event is represented by a piggy-back basin developed on top of the NW-ward moving thrust sheets. In the late Lower Miocene, Group C and N display a typical subsidence pattern for the pull-apart basin with a very high subsidence event (0.2 - 1.0 km/Ma). After the event, Group N shows remarkably decreasing subsidence, following the thin-skinned extension which was regarded as the extension model of the Vienna Basin in the literature. But the subsidence in

  8. Study on Land Subsidence Incangzhou Area Basedon SENTINEL-1A/B Data (United States)

    Zhou, H.; Wang, Y.; Yan, S.


    This paper, obtaining 39scenesof images of the Sentinel-1 A/B, monitored the Cangzhou area subsidence from Mar. 2015 to Dec. 2016 basing on using PS-InSAR technique. The annual average subsidence rate and accumulative subsidence were obtained. The results showed that the ground surface of Xian County,Cang County, Cangzhou urban area had a rebound trend; Qing County, the east of Cang County ,the west of Nanpi County and Dongguang County appeared obvious subsidence, and the accumulated subsidence in Hezhuang village of Dongguang County reached 47 mm. And from that the main reason leading to these obvious subsidence was over-exploitation of ground-water. At last, it analyzed the settlement of the High-Speed Railway (HR) which was north from the Machang town of QingCounty and south to the Lian town of Dongguang County in Cangzhou.The relative deformation of the HR between the two sections which was Lierzhuang village of Cang County and Chenxin village of Nanpi County arrived at 30 mm. Moreover, this paper discussed the application of Sentinel-1 A/B SAR images in monitoring urban land subsidence and the results provided important basic data for the relevant departments.

  9. A theoretical model of subsidence caused by petroleum production: Big Hill Field, Jefferson County, Texas

    International Nuclear Information System (INIS)

    Hill, D.W.; Sharp, J.M. Jr.


    In the Texas Gulf Coastal Plain, there is a history of oil and gas production extending over 2 to 5 decades. Concurrent with this production history, there has been unprecedented population growth accompanied by vastly increased groundwater demands. Land subsidence on both local and regional bases in this geologic province has been measured and predicted in several studies. The vast majority of these studies have addressed the problem from the standpoint of groundwater usage while only a few have considered the effects of oil and gas production. Based upon field-based computational techniques (Helm, 1984), a model has been developed to predict land subsidence caused by oil and gas production. This method is applied to the Big Hill Field in Jefferson County, Texas. Inputs include production data from a series of wells in this field and lithologic data from electric logs of these same wells. Outputs include predicted amounts of subsidence, the time frame of subsidence, and sensitivity analyses of compressibility and hydraulic conductivity estimates. Depending upon estimated compressibility, subsidence, to date, is predicted to be as high as 20 cm. Similarly, depending upon estimated vertical hydraulic conductivity, the time frame may be decades for this subsidence. These same methods can be applied to other oil/gas fields with established production histories as well as new fields when production scenarios are assumed. Where subsidence has been carefully measured above petroleum reservoir, the model may be used inversely to calculate sediment compressibilities

  10. Simulating the hydrologic cycle in coal mining subsidence areas with a distributed hydrologic model. (United States)

    Wang, Jianhua; Lu, Chuiyu; Sun, Qingyan; Xiao, Weihua; Cao, Guoliang; Li, Hui; Yan, Lingjia; Zhang, Bo


    Large-scale ground subsidence caused by coal mining and subsequent water-filling leads to serious environmental problems and economic losses, especially in plains with a high phreatic water level. Clarifying the hydrologic cycle in subsidence areas has important practical value for environmental remediation, and provides a scientific basis for water resource development and utilisation of the subsidence areas. Here we present a simulation approach to describe interactions between subsidence area water (SW) and several hydrologic factors from the River-Subsidence-Groundwater Model (RSGM), which is developed based on the distributed hydrologic model. Analysis of water balance shows that the recharge of SW from groundwater only accounts for a small fraction of the total water source, due to weak groundwater flow in the plain. The interaction between SW and groundwater has an obvious annual cycle. The SW basically performs as a net source of groundwater in the wet season, and a net sink for groundwater in the dry season. The results show there is an average 905.34 million m 3 per year of water available through the Huainan coal mining subsidence areas (HCMSs). If these subsidence areas can be integrated into water resource planning, the increasingly precarious water supply infrastructure will be strengthened.

  11. Application of decision tree model for the ground subsidence hazard mapping near abandoned underground coal mines. (United States)

    Lee, Saro; Park, Inhye


    Subsidence of ground caused by underground mines poses hazards to human life and property. This study analyzed the hazard to ground subsidence using factors that can affect ground subsidence and a decision tree approach in a geographic information system (GIS). The study area was Taebaek, Gangwon-do, Korea, where many abandoned underground coal mines exist. Spatial data, topography, geology, and various ground-engineering data for the subsidence area were collected and compiled in a database for mapping ground-subsidence hazard (GSH). The subsidence area was randomly split 50/50 for training and validation of the models. A data-mining classification technique was applied to the GSH mapping, and decision trees were constructed using the chi-squared automatic interaction detector (CHAID) and the quick, unbiased, and efficient statistical tree (QUEST) algorithms. The frequency ratio model was also applied to the GSH mapping for comparing with probabilistic model. The resulting GSH maps were validated using area-under-the-curve (AUC) analysis with the subsidence area data that had not been used for training the model. The highest accuracy was achieved by the decision tree model using CHAID algorithm (94.01%) comparing with QUEST algorithms (90.37%) and frequency ratio model (86.70%). These accuracies are higher than previously reported results for decision tree. Decision tree methods can therefore be used efficiently for GSH analysis and might be widely used for prediction of various spatial events. Copyright © 2013. Published by Elsevier Ltd.

  12. Average course approximation of measured subsidence and inclinations of mining area by smooth splines

    Directory of Open Access Journals (Sweden)

    Justyna Orwat


    Full Text Available The results of marking average courses of subsidence measured on the points of measuring line no. 1 of the “Budryk” Hard Coal Mine, set approximately perpendicularly to a face run of four consecutively mined longwalls in coal bed 338/2 have been presented in the article. Smooth splines were used to approximate the average course of measured subsidence after subsequent exploitation stages. The minimising of the sum of the squared differences between the average and forecasted subsidence, using J. Bialek's formula, was used as a selection criterion of parameter values of smoothing an approximating function. The parameter values of this formula have been chosen in order to match forecasted subsidence with measured ones. The average values of inclinations have been calculated on the basis of approximated values of observed subsidence. It has been shown that by doing this the average values of extreme measured inclinations can be obtained in almost the same way as extreme observed inclinations. It is not necessary to divide the whole profile of a subsidence basin into parts. The obtained values of variability coefficients of a random scattering for subsidence and inclinations are smaller than their values which occur in the literature.

  13. Protection characteristics of a Faraday cage compromised by lightning burnthrough.

    Energy Technology Data Exchange (ETDEWEB)

    Warne, Larry Kevin; Bystrom, Edward; Jorgenson, Roy Eberhardt; Montoya, Sandra L.; Merewether, Kimball O.; Coats, Rebecca Sue; Martinez, Leonard E.; Jojola, John M.


    A lightning flash consists of multiple, high-amplitude but short duration return strokes. Between the return strokes is a lower amplitude, continuing current which flows for longer duration. If the walls of a Faraday cage are made of thin enough metal, the continuing current can melt a hole through the metal in a process called burnthrough. A subsequent return stroke can couple energy through this newly-formed hole. This LDRD is a study of the protection provided by a Faraday cage when it has been compromised by burnthrough. We initially repeated some previous experiments and expanded on them in terms of scope and diagnostics to form a knowledge baseline of the coupling phenomena. We then used a combination of experiment, analysis and numerical modeling to study four coupling mechanisms: indirect electric field coupling, indirect magnetic field coupling, conduction through plasma and breakdown through the hole. We discovered voltages higher than those encountered in the previous set of experiments (on the order of several hundreds of volts).

  14. Regulation of a phage endolysin by disulfide caging. (United States)

    Kuty, Gabriel F; Xu, Min; Struck, Douglas K; Summer, Elizabeth J; Young, Ry


    In contrast to canonical phage endolysins, which require holin-mediated disruption of the membrane to gain access to attack the cell wall, signal anchor release (SAR) endolysins are secreted by the host sec system, where they accumulate in an inactive form tethered to the membrane by their N-terminal SAR domains. SAR endolysins become activated by various mechanisms upon release from the membrane. In its inactive form, the prototype SAR endolysin, Lyz(P1), of coliphage P1, has an active-site Cys covalently blocked by a disulfide bond; activation involves a disulfide bond isomerization driven by a thiol in the newly released SAR domain, unblocking the active-site Cys. Here, we report that Lyz(103), the endolysin of Erwinia phage ERA103, is also a SAR endolysin. Although Lyz(103) does not have a catalytic Cys, genetic evidence suggests that it also is activated by a thiol-disulfide isomerization triggered by a thiol in the SAR domain. In this case, the inhibitory disulfide in nascent Lyz(103) is formed between cysteine residues flanking a catalytic glutamate, caging the active site. Thus, Lyz(P1) and Lyz(103) define subclasses of SAR endolysins that differ in the nature of their inhibitory disulfide, and Lyz(103) is the first enzyme found to be regulated by disulfide bond caging of its active site.

  15. Automated Operant Conditioning in the Mouse Home Cage. (United States)

    Francis, Nikolas A; Kanold, Patrick O


    Recent advances in neuroimaging and genetics have made mice an advantageous animal model for studying the neurophysiology of sensation, cognition, and locomotion. A key benefit of mice is that they provide a large population of test subjects for behavioral screening. Reflex-based assays of hearing in mice, such as the widely used acoustic startle response, are less accurate than operant conditioning in measuring auditory processing. To date, however, there are few cost-effective options for scalable operant conditioning systems. Here, we describe a new system for automated operant conditioning, the Psibox. It is assembled from low cost parts, designed to fit within typical commercial wire-top cages, and allows large numbers of mice to train independently in their home cages on positive reinforcement tasks. We found that groups of mice trained together learned to accurately detect sounds within 2 weeks of training. In addition, individual mice isolated from groups also showed good task performance. The Psibox facilitates high-throughput testing of sensory, motor, and cognitive skills in mice, and provides a readily available animal population for studies ranging from experience-dependent neural plasticity to rodent models of mental disorders.

  16. Evidences of long lived cages in functionalized polymers: Effects on chromophore dynamic and spectroscopic properties (United States)

    Prampolini, Giacomo; Monti, Susanna; De Mitri, Nicola; Barone, Vincenzo


    action on the dye, can be evinced from the analysis of selected dynamic properties, related to NfO-TEMPO translational and rotational motions and to the residence times of the neighboring groups into the first neighbors shell. All the details for the calculations of the latter three properties are also defined in the Supporting Information. As far as the dye translational dynamics is concerned, the mean square displacement (MSD) of the probe in the two different environments was monitored as a function of time and shown with solid lines in Figure 3. When the probe is grafted onto the polymer (orange line), the MSD reveals a sub-diffusive regime which is identified by the plateau visible in the logarithmic scale the Figure referenced above. This is a typical signature of a β-relaxation, that takes place from the end of the pure ballistic dynamics (hundreds of femtoseconds) to the onset of the linear behavior (visible after around 100 ps). It could be speculated that this trend might be due on the one hand, to the intrinsic sub-diffusive character of the dynamics of the polymer bundle which is transmitted to the dye through the grafting process, and on the other hand, to the polymer cage around the probe which prevents it from reaching a true diffusive regime. This analysis can be extended to the re-orientational processes, by investigating the relaxation of the main molecular axes of the dye (α,β,γ). To this end, the auto correlation function of the first Legendre polynomial (P1) of one (β) of the tumbling axes is plotted vs time and shown in Figure 3. A qualitatively similar behavior was found for the other axes. The different role played by the two embeddings appears clearly from the comparison of the two data sets. Indeed, while in the less structured solvent (toluene), a relatively fast reorientation of the dye takes place, and the P1 function drops below 0.5 after ∼10 ps, in the other case (polymer) a neat plateau again appears in the 1-100 ps range, and the

  17. Land subsidence and earth fissures in south-central and southern Arizona, USA (United States)

    Conway, Brian D.


    Land subsidence due to groundwater overdraft has been an ongoing problem in south-central and southern Arizona (USA) since the 1940s. The first earth fissure attributed to excessive groundwater withdrawal was discovered in the early 1950s near Picacho. In some areas of the state, groundwater-level declines of more than 150 m have resulted in extensive land subsidence and earth fissuring. Land subsidence in excess of 5.7 m has been documented in both western metropolitan Phoenix and Eloy. The Arizona Department of Water Resources (ADWR) has been monitoring land subsidence since 2002 using interferometric synthetic aperture radar (InSAR) and since 1998 using a global navigation satellite system (GNSS). The ADWR InSAR program has identified more than 25 individual land subsidence features that cover an area of more than 7,300 km2. Using InSAR data in conjunction with groundwater-level datasets, ADWR is able to monitor land subsidence areas as well as identify areas that may require additional monitoring. One area of particular concern is the Willcox groundwater basin in southeastern Arizona, which is the focus of this paper. The area is experiencing rapid groundwater declines, as much as 32.1 m during 2005-2014 (the largest land subsidence rate in Arizona State—up to 12 cm/year), and a large number of earth fissures. The declining groundwater levels in Arizona are a challenge for both future groundwater availability and mitigating land subsidence associated with these declines. ADWR's InSAR program will continue to be a critical tool for monitoring land subsidence due to excessive groundwater withdrawal.

  18. Bisphenol A is released from used polycarbonate animal cages into water at room temperature (United States)

    Howdeshell, Kembra L.; Peterman, Paul H.; Judy, Barbara M.; Taylor, Julia A.; Orazio, Carl E.; Ruhlen, Rachel L.; vom Saal, Frederick S.; Welshons, Wade V.


    Bisphenol A (BPA) is a monomer with estrogenic activity that is used in the production of food packaging, dental sealants, polycarbonate plastic, and many other products. The monomer has previously been reported to hydrolyze and leach from these products under high heat and alkaline conditions, and the amount of leaching increases as a function of use. We examined whether new and used polycarbonate animal cages passively release bioactive levels of BPA into water at room temperature and neutral pH. Purified water was incubated at room temperature in new polycarbonate and polysulfone cages and used (discolored) polycarbonate cages, as well as control (glass and used polypropylene) containers. The resulting water samples were characterized with gas chromatography/mass spectrometry (GC/MS) and tested for estrogenic activity using an MCF-7 human breast cancer cell proliferation assay. Significant estrogenic activity, identifiable as BPA by GC/MS (up to 310 micro g/L), was released from used polycarbonate animal cages. Detectable levels of BPA were released from new polycarbonate cages (up to 0.3 micro g/L) as well as new polysulfone cages (1.5 micro g/L), whereas no BPA was detected in water incubated in glass and used polypropylene cages. Finally, BPA exposure as a result of being housed in used polycarbonate cages produced a 16% increase in uterine weight in prepubertal female mice relative to females housed in used polypropylene cages, although the difference was not statistically significant. Our findings suggest that laboratory animals maintained in polycarbonate and polysulfone cages are exposed to BPA via leaching, with exposure reaching the highest levels in old cages.

  19. Relating large-scale subsidence to convection development in Arctic mixed-phase marine stratocumulus (United States)

    Young, Gillian; Connolly, Paul J.; Dearden, Christopher; Choularton, Thomas W.


    Large-scale subsidence, associated with high-pressure systems, is often imposed in large-eddy simulation (LES) models to maintain the height of boundary layer (BL) clouds. Previous studies have considered the influence of subsidence on warm liquid clouds in subtropical regions; however, the relationship between subsidence and mixed-phase cloud microphysics has not specifically been studied. For the first time, we investigate how widespread subsidence associated with synoptic-scale meteorological features can affect the microphysics of Arctic mixed-phase marine stratocumulus (Sc) clouds. Modelled with LES, four idealised scenarios - a stable Sc, varied droplet (Ndrop) or ice (Nice) number concentrations, and a warming surface (representing motion southwards) - were subjected to different levels of subsidence to investigate the cloud microphysical response. We find strong sensitivities to large-scale subsidence, indicating that high-pressure systems in the ocean-exposed Arctic regions have the potential to generate turbulence and changes in cloud microphysics in any resident BL mixed-phase clouds.Increased cloud convection is modelled with increased subsidence, driven by longwave radiative cooling at cloud top and rain evaporative cooling and latent heating from snow growth below cloud. Subsidence strengthens the BL temperature inversion, thus reducing entrainment and allowing the liquid- and ice-water paths (LWPs, IWPs) to increase. Through increased cloud-top radiative cooling and subsequent convective overturning, precipitation production is enhanced: rain particle number concentrations (Nrain), in-cloud rain mass production rates, and below-cloud evaporation rates increase with increased subsidence.Ice number concentrations (Nice) play an important role, as greater concentrations suppress the liquid phase; therefore, Nice acts to mediate the strength of turbulent overturning promoted by increased subsidence. With a warming surface, a lack of - or low - subsidence

  20. Relating large-scale subsidence to convection development in Arctic mixed-phase marine stratocumulus

    Directory of Open Access Journals (Sweden)

    G. Young


    Full Text Available Large-scale subsidence, associated with high-pressure systems, is often imposed in large-eddy simulation (LES models to maintain the height of boundary layer (BL clouds. Previous studies have considered the influence of subsidence on warm liquid clouds in subtropical regions; however, the relationship between subsidence and mixed-phase cloud microphysics has not specifically been studied. For the first time, we investigate how widespread subsidence associated with synoptic-scale meteorological features can affect the microphysics of Arctic mixed-phase marine stratocumulus (Sc clouds. Modelled with LES, four idealised scenarios – a stable Sc, varied droplet (Ndrop or ice (Nice number concentrations, and a warming surface (representing motion southwards – were subjected to different levels of subsidence to investigate the cloud microphysical response. We find strong sensitivities to large-scale subsidence, indicating that high-pressure systems in the ocean-exposed Arctic regions have the potential to generate turbulence and changes in cloud microphysics in any resident BL mixed-phase clouds.Increased cloud convection is modelled with increased subsidence, driven by longwave radiative cooling at cloud top and rain evaporative cooling and latent heating from snow growth below cloud. Subsidence strengthens the BL temperature inversion, thus reducing entrainment and allowing the liquid- and ice-water paths (LWPs, IWPs to increase. Through increased cloud-top radiative cooling and subsequent convective overturning, precipitation production is enhanced: rain particle number concentrations (Nrain, in-cloud rain mass production rates, and below-cloud evaporation rates increase with increased subsidence.Ice number concentrations (Nice play an important role, as greater concentrations suppress the liquid phase; therefore, Nice acts to mediate the strength of turbulent overturning promoted by increased subsidence. With a warming surface, a lack of – or

  1. Subsidence of titanium straight stems in combination with highly viscous bone cement


    Hendrich, Christian; Sauer, Ulf; Albrecht, Tobias; Rader, Christof P.


    Varying results and a high rate of subsidence have been reported for the straight femoral stem (M.E. Müller) made of titanium alloy. We examined subsidence in 135 titanium-alloy straight stems implanted with high viscosity cement after 68.8±11.5 months using a digital high-precision method (EBRA-FCA). One revised implant showed a subsidence of 14.6 mm and another 2.5 mm over 5 years. A third implant without migration was found to be loose. The 122 implants without loosening showed a mean subs...

  2. Dynamic Subsidence across the Late Cretaceous Western Interior Basin in Response to Farallon Slab Subduction (United States)

    Liu, S.; Nummedal, D.; Liu, L.


    The United States Cretaceous Western Interior Basin has long been considered a foreland basin, driven by the Sevier thrust and associated basin sediment loads. However, flexural studies demonstrate that this effect exists only within a narrow band in front of the thrust belt. Most of the basin appears to be due to mantle flow-induced dynamic subsidence associated with Farallon plate subduction. Here we show how the components of evolving long-wavelength dynamic subsidence and flexural subsidence created the accommodation space and controlled the stratigraphy across the western United Sates, based on the correlated stratigraphic sections across central Utah-Colorado and southern Wyoming.These backstripped subsidence data reveal a component of continuously evolving long-wavelength dynamic subsidence, in addition to subsidence driven by the Sevier thrust belt and associated sediment loads. The loci of maximum rates of this dynamic subsidence moved eastward from ~98 to 74 Ma in phase with the west-to-east passage of the Farallon slab, as reconstructed from tomography based on quantitative inverse models. These subsidence data allow testing of existing subduction models and confirm the dynamic-topography driven nature of the Western Interior Basin. The results seem to support that the depocenters track the trough of dynamic subsidence with ca.18 Myr cycles through time and space and the stratigraphic patterns of large-scale progradation, eastward migration of depocenter, and regional clinoform-like downlap are related with the dynamic subsidence. Interpretation of these data also provides more insights into the repeated, ca.2 to 6 Myr cycles of thrust-induced subsidence in front of the thrust belt, which control the local eastward progradation of the sand bodies from the thrust belt. The dynamic, flexural subsidence and eustatic sea level changes interacted and controlled the timing and distribution of unconformities. Our work shows how the stratigraphy precisely

  3. Correlation between precision gravity and subsidence measurements at Cerro Prieto (United States)

    Zelwer, R.; Grannell, R. B.


    Precision gravity measurements were made in the region of the Cerro Prieto geothermal field at yearly intervals from 1977 to 1981 to assess the feasibility of using gravity to determine subsurface reservoir changes with time. The extent of mass recharge in response to the continued production of fluids from this field was studied. Changes in gravity and ground elevation were observed throughout the region for the period of observation. Results indicate that the largest changes observed were the result of the Magnitude 6.1 (Caltech) Victoria earthquake of 8 June 1980. The epicenter of this earthquake was located 25 km southeast of the field on the Cerro Prieto Fault, which bounds the field on the southwest. Subsidence of up to 55 cm was measured east of the power plant, in the region between the northern end of the Cerro Prieto Fault and the southern end of the Imperial Fault. This area has been postulated to be the site of an active spreading center or pull-apart basin, and has been characterized by a high level of seismic activity during the last 10 years.

  4. Outcome in the treatment of discopathy by interbody fusion with the posterior approach using metal cages. (United States)

    Milecki, Marcin; Lukawski, Stanisław; Rapała, Kazimierz; Białecki, Jerzy


    Background. Discopathy most often occurs in persons from 20 to 50 years old, in the period of greatest physical and intellectual capacity, and thus poses a major social problem. The goal of our research was to evaluation the outcome of interbody fusion performed with metal cages. Material and methods. We operated 52 patients ranging in age from 29 to 60, who presented with prolapse of the nucleus pulposus (21 patients), instability (8 patients), lumbar stenosis (11 patients), and recurrent discopathy with spondylolisthesis (12 patients). Interbody fusion was performed on these patients from the posterior approach using metal implants. Results. Applying both subjective and radiological criteria, we obtained good outcome in 36 cases, satisfactory in 12 cases, and unsatisfactory in 4 cases. A follow-up at 4 years after surgery showed that the solution was effective in preventing lumbar stenosis and intervertebral instability. However, there were still difficulties in the assessment of bone union. Conclusions. Maintaining or expanding the height of the interbody space by using implants is indicated by radiography in our material to be the most important surgical intervention justifying the use of this method. Interbody fusion in discopathy using metal implants is a logical solution to prevent secondary stenosis of the vertebral canal and intervertebral instability. The outcomes obtained at 4-year follow-up should be regarded as satisfactory.

  5. Improving aeration for efficient oxygenation in sea bass sea cages. Blood, brain and gill histology

    Directory of Open Access Journals (Sweden)

    Berillis Panagiotis


    Full Text Available An air diffusion based system (Airx was developed to control the dissolved oxygen levels in aquaculture sea cages. The system was introduced and then tested for 37 days in a sea bass sea cage (aerated cage. A second sea bass sea cage, without the AirX, was used as a control. Oxygen levels were measured in both cages at the start of the trial, before the AirX system was introduced, and during the working period of the AirX system. Fish samples were collected 15 days after the AirX system was introduced and at the end of the experiment. Blood smears were prepared and examined microscopically. Erythrocyte major axis, minor axis and area of fish erythrocytes were measured. Leucocyte differentiation was also examined. In the control cage, the fish had significantly larger red blood cells when compared with the red blood cells of the fish in the aerated cage. Histological examination of the gills and brain revealed no morphological differences or alterations between the two groups of fish. This study demonstrated that an air diffuser system could improve the water quality of fish farmed in sea cages and enhance sea bass physiological performance, especially if DO levels fall below 60% oxygen saturation.

  6. A pyrrolo-tetrathiafulvalene cage: Synthesis and X-ray crystal structure

    DEFF Research Database (Denmark)

    Nielsen, Kent A.; Jeppesen, Jan O.; Levillain, Eric


    A novel type of tetrathiafulvalene-cage 4 containing three monopyrrolo-tetrathiafulvalene units has been prepared employing a general and efficient synthetic approach. X-ray crystal structure analysis revealed that the cage is able to accommodate solvent molecules within a cavity in the solid state....

  7. Formation of Ti28 ln cages, the highest nuclearity polyoxotitanates (Ln = La, Ce). (United States)

    Lv, Yaokang; Willkomm, Janina; Leskes, Michal; Steiner, Alexander; King, Timothy C; Gan, Lihua; Reisner, Erwin; Wood, Paul T; Wright, Dominic S


    The solvothermal reactions of Ti(OEt)(4) with LnCl(3) (Ln = La, Ce) produced new Ti(28) Ln cages, in which the Ln(3+) ions are coordinated within a metallocrown arrangement, which represents the highest nuclearity cages of this type (see figure). Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. Recombinant expression and purification of 'virus-like' bacterial encapsulin protein cages

    NARCIS (Netherlands)

    Rurup, W.F.; Cornelissen, Jeroen Johannes Lambertus Maria; Koay, M.S.T.; Orner, Brendan P.


    Ultracentrifugation, particularly the use of sucrose or cesium chloride density gradients, is a highly reliable and efficient technique for the purification of virus-like particles and protein cages. Since virus-like particles and protein cages have a unique size compared to cellular macromolecules

  9. Standard methods for maintaining adult Apis mellifera in cages under in vitro laboratory conditions

    NARCIS (Netherlands)

    Williams, G.R.; Alaux, C.; Costa, C.; Csaki, C.; Steen, van der J.J.M.


    Adult honey bees are maintained in vitro in laboratory cages for a variety of purposes. For example, researchers may wish to perform experiments on honey bees caged individually or in groups to study aspects of parasitology, toxicology, or physiology under highly controlled conditions, or they may

  10. The Effects of Caging on the Colonization of Fouling Organisms in ...

    African Journals Online (AJOL)

    The effects of caging on the colonization and development of the fouling community in the upper Bonny estuary was studied. The experimental design was such that sets of wooden panels (20x20 cm) were screened with cages constructed with plastic netting while another set was left uncaged. Both sets of panels were ...

  11. Sterilization and strength of 70/30 polylactide cages: e-beam versus ethylene oxide

    NARCIS (Netherlands)

    Smit, Theo H.; Thomas, Kevin A.; Hoogendoorn, Roel J. W.; Strijkers, Gustav J.; Helder, Marco N.; Wuisman, Paul I. J. M.


    In vitro and in vivo studies on the degradation of 70/30 poly(L,DL-lactide) (PLDLLA) cages. To evaluate the effect of e-beam and ethylene oxide sterilization on degradation and strength. e-beam-sterilized PLDLLA cages were shown to maintain mechanical strength for at least 6 months during

  12. Effects of housing system (outdoor vs cages) and age of laying hens on egg characteristics

    NARCIS (Netherlands)

    Brand, van den H.; Parmentier, H.K.; Kemp, B.


    1. Effects of two housing systems (cages vs outdoor) on external and internal egg characteristics were investigated. 2. In total 785 eggs from three different lines in cages and 268 eggs from outdoor-housed layers were examined for egg weight, albumen, yolk and shell content, albumen height and pH,

  13. Effects of cage fish culture on water quality and selected biological ...

    African Journals Online (AJOL)

    Growing of fish in cages is currently practiced in Uganda and was first introduced in northern Lake Victoria in 2010. An environment monitoring study was undertaken at Source of the Nile, a private cage fish farm, in Napoleon gulf, northern Lake Victoria. In-situ measurements of key environmental (temperature, dissolved ...

  14. Self-Assembly, Guest Capture, and NMR Spectroscopy of a Metal-Organic Cage in Water (United States)

    Go, Eun Bin; Srisuknimit, Veerasak; Cheng, Stephanie L.; Vosburg, David A.


    A green organic-inorganic laboratory experiment has been developed in which students prepare a self-assembling iron cage in D[subscript 2]O at room temperature. The tetrahedral cage captures a small, neutral molecule such as cyclohexane or tetrahydrofuran. [Superscript 1]H NMR analysis distinguishes captured and free guests through diagnostic…

  15. Solid state and aqueous behavior of uranyl peroxide cage clusters (United States)

    Pellegrini, Kristi Lynn

    Uranyl peroxide cage clusters include a large family of more than 50 published clusters of a variety of sizes, which can incorporate various ligands including pyrophosphate and oxalate. Previous studies have reported that uranyl clusters can be used as a method to separate uranium from a solid matrix, with potential applications in reprocessing of irradiated nuclear fuel. Because of the potential applications of these novel structures in an advanced nuclear fuel cycle and their likely presence in areas of contamination, it is important to understand their behavior in both solid state and aqueous systems, including complex environments where other ions are present. In this thesis, I examine the aqueous behavior of U24Pp 12, as well as aqueous cluster systems with added mono-, di-, and trivalent cations. The resulting solutions were analyzed using dynamic light scattering and ultra-small angle X-ray scattering to evaluate the species in solution. Precipitates of these systems were analyzed using powder X-ray diffraction, X-ray fluorescence spectrometry, and Raman spectroscopy. The results of these analyses demonstrate the importance of cation size, charge, and concentration of added cations on the aqueous behavior of uranium macroions. Specifically, aggregates of various sizes and shapes form rapidly upon addition of cations, and in some cases these aggregates appear to precipitate into an X-ray amorphous material that still contains U24Pp12 clusters. In addition, I probe aggregation of U24Pp12 and U60, another uranyl peroxide cage cluster, in mixed solvent water-alcohol systems. The aggregation of uranyl clusters in water-alcohol systems is a result of hydrogen bonding with polar organic molecules and the reduction of the dielectric constant of the system. Studies of aggregation of uranyl clusters also allow for comparison between the newer uranyl polyoxometalate family and century-old transition metal polyoxometalates. To complement the solution studies of uranyl

  16. Effects of manual rib cage compressions on expiratory flow and mucus clearance during mechanical ventilation. (United States)

    Martí, Joan Daniel; Li Bassi, Gianluigi; Rigol, Montserrat; Saucedo, Lina; Ranzani, Otavio Tavares; Esperatti, Mariano; Luque, Nestor; Ferrer, Miquel; Vilaro, Jordi; Kolobow, Theodor; Torres, Antoni


    We investigated the effects of two different types of manual rib cage compression on expiratory flow and mucus clearance during prolonged mechanical ventilation in pigs. Prospective randomized animal study. Animal research facility, University of Barcelona, Spain. Nine healthy pigs. Pigs were tracheally intubated, sedated, paralyzed, and mechanically ventilated. The animals were prone on a surgical bed in the anti-Trendelenburg position. The experiments were carried out at approximately 60 and 80 hrs from the beginning of mechanical ventilation. Two types of manual rib cage compressions were tested: Hard and brief rib cage compressions synchronized with early expiratory phase (hard manual rib cage compression) and soft and gradual rib cage compressions applied during the late expiratory phase (soft manual rib cage compression). The interventions were randomly applied for 15min with a 15-min interval between treatments. Respiratory flow and mucus movement were assessed during the interventions. Respiratory mechanics and hemodynamics were assessed prior to and after the interventions. Peak expiratory flow increased to 60.1±7.1L/min in comparison to 51.2±4.6L/min without treatment (p < 0.0015) and 48.7±4.3L/min with soft manual rib cage compression (p = 0.0002). Similarly, mean expiratory flow increased to 28.4±5.2L/min during hard manual rib cage compression vs. 15.9±2.2 and 16.6±2.8L/min without treatment and soft manual rib cage compression, respectively (p = 0.0006). During hard manual rib cage compression, mucus moved toward the glottis (1.01 ± 2.37mm/min); conversely, mucus moved toward the lungs during no treatment and soft manual rib cage compression, -0.28 ± 0.61 and -0.15±0.95mm/min, respectively (p = 0.0283). Soft manual rib cage compression slightly worsened static lung elastance and cardiac output (p = 0.0391). Hard manual rib cage compression improved mucus clearance in animals positioned in the anti-Trendelenburg position. The technique

  17. Resistivity changes of rock massif on the margin of subsidence depression

    Czech Academy of Sciences Publication Activity Database

    Bláha, P.; Doležalová, Hana; Duras, R.; Müller, Karel

    Zeszyt 4, č. 4 (2007), s. 5-12 ISSN 1896-3145 Institutional research plan: CEZ:AV0Z30860518 Keywords : resistivity * subsidence * geophysics Subject RIV: DC - Siesmology, Volcanology, Earth Structure

  18. InSAR detects increase in surface subsidence caused by an Arctic tundra fire (United States)

    Liu, Lin; Jafarov, Elchin E.; Schaefer, Kevin M.; Jones, Benjamin M.; Zebker, Howard A.; Williams, Christopher A.; Rogan, John; Zhang, Tingjun


    Wildfire is a major disturbance in the Arctic tundra and boreal forests, having a significant impact on soil hydrology, carbon cycling, and permafrost dynamics. This study explores the use of the microwave Interferometric Synthetic Aperture Radar (InSAR) technique to map and quantify ground surface subsidence caused by the Anaktuvuk River fire on the North Slope of Alaska. We detected an increase of up to 8 cm of thaw-season ground subsidence after the fire, which is due to a combination of thickened active layer and permafrost thaw subsidence. Our results illustrate the effectiveness and potential of using InSAR to quantify fire impacts on the Arctic tundra, especially in regions underlain by ice-rich permafrost. Our study also suggests that surface subsidence is a more comprehensive indicator of fire impacts on ice-rich permafrost terrain than changes in active layer thickness alone.

  19. Using Persistent Scatterers Interferometry to create a subsidence map of the Nile Delta in Egypt (United States)

    Bouali, E. Y.; Sultan, M.; Becker, R.; Cherif, O.


    Inhabitants of the Nile Delta in Egypt, especially those who live around the coast, are threatened by two perpetual hazards: (1) sea level rise and encroachment from the Mediterranean Sea and (2) land subsidence that is inherent in deltaic environments. With cities like Alexandria and Port Said currently only one meter above sea level, it is important to understand the nature of the sea level rise and land subsidence, both spatially and temporally, and to be able to quantify these hazards. The magnitude of sea level rise has been actively monitored in stations across the Mediterranean Sea; the subsidence of the Nile Delta, as a whole system however, has not been adequately quantified. We have employed the Differential Synthetic Aperture Radar Interferometry (DInSAR) technique known as Persistent Scatterers Interferometry (PSI) across the entire northern parts of the Nile Delta. A dataset of 106 ENVISAT single look complex (SLC) scenes (four descending tracks: 164, 207, 436, and 479) acquired throughout the time period 2003 to 2010 were obtained from the European Space Agency and utilized for radar interferometric purposes. Multiple combinations of these scenes - used for output optimization and validation - were processed. Due to the nature of the PSI technique, subsidence rates calculated using this technique are values measured from cities and urban areas - where PSI works well. The methodology of choice is to calculate the subsidence rates on a city-by-city basis by: (1) choosing an urban area and cutting the SLC scene stack down to a small area (25 - 200 km2); (2) processing this area multiple times using difference scene and parameter combinations in order to best optimize persistent scatterer (PS) abundance and ground displacement measurements; (3) calibrating the relative ground motion measured by PSI to known locations of minimal subsidence rates. The final result is a spatial representation of the subsidence rates across the Nile Delta in Egypt. Measured

  20. Determination of Elastic Parameters of Near-Surface Layers Over Subsidence Trough Development During Longwall Exploitation (United States)

    Mendecki, Maciej J.; Jochymczyk, Krzysztof; Zuberek, Wacław M.; Tomaszewska, Radosława


    Seismic and geodetic studies were carried out before, during, and after underground exploitation of a coal bed in Katowice - Kleofas Coal Mine, located in the Upper Silesia Coal Basin, Poland. Development of a subsidence trough was completed approximately 3 months after passage of a longwall exploitation in the coal seam. This was the time required for the subsidence trough to appear on the surface, which was confirmed by levelling measurements. Sharp changes in the elastic parameters were observed on each profile during subsidence trough development. This observation can result from changing tension and compression forces caused by increase and/or decrease of the elastic parameters of the rock mass. After completion of subsidence trough development, the rock mass appeared to return to its isotropic state and the observed changes ceased. Some minor fluctuations were noted, but they probably resulted from changes in groundwater levels, which might have affected the measured parameters.

  1. Implications of ground-deformation measurements across earth fissures in subsidence areas in the southwestern USA (United States)

    Holzer, Thomas L.


    Ground deformation was monitored at earth fissures in areas of land subsidence induced by groundwater extraction in the southwestern United States. The ground deformation is consistent with the mechanism that fissures are caused by horizontal strains generated by bending of overburden in response to localized differential compaction. Subsidence profiles indicated that localized differential subsidence occurred across the fissures and that maximum convex-upward curvature was at the fissure. The overall shape of the profile stayed similar with time, and maximum curvature remained stationary at the fissure. Horizontal displacements were largest near the fissure, and generally were small to negligible away from the fissure. Maximum tensile horizontal strains were at the fissure and coincided with maximum curvature in the subsidence profiles. Horizontal tensile strain continued to accumulate at fissures after they formed with rates of opening ranging from 30 to 120 microstrain/year at fissures in Arizona.

  2. Threat of land subsidence in and around Kolkata City and East ...

    Indian Academy of Sciences (India)


    Aug 26, 2016 ... Keywords. Kolkata; East Kolkata Wetlands; groundwater; land subsidence; groundwater potential; sustainable development. ... Demand of groundwater for drinking, agricultural and industrial purposes has increased due to rapid urbanization. The subsurface geology consists of Quaternary sediments ...

  3. InSAR detects increase in surface subsidence caused by an Arctic tundra fire (United States)

    Liu, Lin; Jafarov, Elchin E.; Schaefer, Kevin M.; Jones, Benjamin M.; Zebker, Howard A.; Williams, Christopher A.; Rogan, John; Zhang, Tingjun


    Wildfire is a major disturbance in the Arctic tundra and boreal forests, having a significant impact on soil hydrology, carbon cycling, and permafrost dynamics. This study explores the use of the microwave Interferometric Synthetic Aperture Radar (InSAR) technique to map and quantify ground surface subsidence caused by the Anaktuvuk River fire on the North Slope of Alaska. We detected an increase of up to 8 cm of thaw-season ground subsidence after the fire, which is due to a combination of thickened active layer and permafrost thaw subsidence. Our results illustrate the effectiveness and potential of using InSAR to quantify fire impacts on the Arctic tundra, especially in regions underlain by ice-rich permafrost. Our study also suggests that surface subsidence is a more comprehensive indicator of fire impacts on ice-rich permafrost terrain than changes in active layer thickness alone.

  4. Tectonic history along the South Gabon Basin: Anomalous early post-rift subsidence

    International Nuclear Information System (INIS)

    Dupre, Stephanie; Bertotti, Giovanni; Cloetingh, Sierd


    An integrated study of the South Gabon Margin (South Atlantic) based on reflection seismic and well data has been performed to quantify tectonic activity. A regional profile crossing the entire basin together with subsidence analysis, highlights important aspects of the post-rift history. The most striking event in the margin evolution appears to be the anomalous extra subsidence during the early post-rift period characterized by high sedimentation rates, equivalent to one third of the syn-rift subsidence. Although the presence of evaporite layers restricts knowledge of the underlying structures essentially composed of pre-rift and syn-rift sequences, the outcome of this post-rift tectonic study has strong implications for the rifting history. The early post-rift subsidence patterns can be related to a high thermal anomaly during the early rifting thermal state of the lithosphere. These findings are highly relevant for petroleum system studies and have implications for hydrocarbon generation. (author)

  5. Particulate waste outflow from fish-farming cages. How much is uneaten feed? (United States)

    Ballester-Moltó, M; Sanchez-Jerez, P; Cerezo-Valverde, J; Aguado-Giménez, F


    Particulate wastes drive benthic organic enrichment from cage fish farming. Differentiation between faeces and uneaten feed estimates at cage level are of great value to both economize the feeding process and reduce waste. This study estimates the particulate waste outflowing cages at different depths and orientations, and the wasted feed component by combining in situ measurements and modelling. Particulate matter flux (PMF) was greater vertically through the cage bottoms (60.89%), but lateral outflow was also substantial (39.11%). PMF occurs all around the cages, and the influence of the mainstream current was low. Wasted feed was greatly variable, reaching high values (about 50% of supplied feed. The self-application of feed wastage monitoring and estimates by fish farmers is recommended to improve sustainability. Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. Parameters estimation of squirrel-cage induction motors using ANN and ANFIS

    Directory of Open Access Journals (Sweden)

    Mehdi Ahmadi Jirdehi


    Full Text Available In the transient behavior analysis of a squirrel-cage induction motor, the parameters of the single-cage and double-cage models are studied. These parameters are usually hard to obtain. This paper presents two new methods to predict the induction motor parameters in the single-cage and double-cage models based on artificial neural network (ANN and adaptive neuro-fuzzy inference system (ANFIS. For this purpose, the experimental data (manufacturer data of 20 induction motors with the different power are used. The experimental data are including of the starting torque and current, maximum torque, full load sleep, efficiency, rated active power and reactive power. The obtained results from the proposed ANN and ANFIS models are compared with each other and with the experimental data, which show a good agreement between the predicted values and the experimental data. But the proposed ANFIS model is more accurate than the proposed ANN model.

  7. The effect of cage size on reproductive performance and behavior of C57BL/6 mice. (United States)

    Whitaker, Julia; Moy, Sheryl S; Saville, Benjamin R; Godfrey, Virginia; Nielsen, Judith; Bellinger, Dwight; Bradfield, John


    Scientific research has yet to conclusively determine the optimal cage size for mice. The authors examined the effect of cage size on mouse breeding performance and on offspring behavior, which can serve as indications of overall well-being. They housed breeding trios of C57BL/6Tac mice in standard or large individually ventilated cages and measured four reproductive parameters: litter size; litter survival to weaning age; average pup weight at 7, 14 and 21 days; and the number of days between litter births. They investigated the behavior of a subset of male and female pups from parents housed in cages of each size in the elevated plus maze test, the open field assay and the acoustic startle test. Cage size had no significant effect on any of the reproductive parameters measured and few or inconsistent effects on behavior in weaned pups.

  8. Effect of small cage guests on hydrogen bonding of tetrahydrofuran in binary structure II clathrate hydrates. (United States)

    Alavi, Saman; Ripmeester, John A


    Molecular dynamics simulations of the pure structure II tetrahydrofuran clathrate hydrate and binary structure II tetrahydrofuran clathrate hydrate with CO(2), CH(4), H(2)S, and Xe small cage guests are performed to study the effect of the shape, size, and intermolecular forces of the small cages guests on the structure and dynamics of the hydrate. The simulations show that the number and nature of the guest in the small cage affects the probability of hydrogen bonding of the tetrahydrofuran guest with the large cage water molecules. The effect on hydrogen bonding of tetrahydrofuran occurs despite the fact that the guests in the small cage do not themselves form hydrogen bonds with water. These results indicate that nearest neighbour guest-guest interactions (mediated through the water lattice framework) can affect the clathrate structure and stability. The implications of these subtle small guest effects on clathrate hydrate stability are discussed.

  9. Update on subsidence at the Wairakei-Tauhara geothermal system, New Zealand

    International Nuclear Information System (INIS)

    Allis, Rick; Bromley, Chris; Currie, Steve


    The total subsidence at the Wairakei field as a result of 50 years of geothermal fluid extraction is 15 ± 0.5 m. Subsidence rates in the center of the subsidence bowl have decreased from over 450 mm/year during the 1970s to 80-90 mm/year during 2000-2007. The location of the bowl, adjacent to the original liquid outflow zone of the field, has not changed significantly. Subsidence at the Tauhara field due to Wairakei production was not as well documented in the early years but appeared later and has been less intense than at Wairakei. Total subsidence of 2.6 ± 0.5 m has also occurred close to the original liquid outflow zone of this field, and maximum subsidence rates in this area today are in the 80-100 mm/year range. In the western part of the Wairakei field, near the area of hot upflow, subsidence rates have approximately doubled during the last 20 years to 30-50 mm/year. This increase appears to be have been caused by declining pressure in the underlying steam zone in this area, which is tapped by some production wells. At Tauhara field, two areas of subsidence have developed since the 1990s with rates of 50-65 mm/year. Although less well-determined, this subsidence may also be caused by declining pressure in shallow steam zones. The cause of the main subsidence bowls in the Wairakei-Tauhara geothermal system is locally high-compressibility rocks within the Huka Falls Formation (HFF), which are predominantly lake sediments and an intervening layer of pumice breccia. At Wairakei, casing deformation suggests the greatest compaction is at 150-200 m depth. The cause of the large compressibility is inferred to be higher clay content in the HFF due to intense hydrothermal alteration close to the natural fluid discharge areas. Future subsidence is predicted to add an additional 2-4 m to the Wairakei bowl, and 1-2 m elsewhere, but these estimates depend on the assumed production-injection scenarios. (author)

  10. Wuhan Surface Subsidence Analysis in 2015–2016 Based on Sentinel-1A Data by SBAS-InSAR

    Directory of Open Access Journals (Sweden)

    Lv Zhou


    Full Text Available The Terrain Observation with Progressive Scans (TOPS acquisition mode of Sentinel-1A provides a wide coverage per acquisition and features a repeat cycle of 12 days, making this acquisition mode attractive for surface subsidence monitoring. A few studies have analyzed wide-coverage surface subsidence of Wuhan based on Sentinel-1A data. In this study, we investigated wide-area surface subsidence characteristics in Wuhan using 15 Sentinel-1A TOPS Synthetic Aperture Radar (SAR images acquired from 11 April 2015 to 29 April 2016 with the Small Baseline Subset Interferometric SAR (SBAS InSAR technique. The Sentinel-1A SBAS InSAR results were validated by 110 leveling points at an accuracy of 6 mm/year. Based on the verified SBAS InSAR results, prominent uneven subsidence patterns were identified in Wuhan. Specifically, annual average subsidence rates ranged from −82 mm/year to 18 mm/year in Wuhan, and maximum subsidence rate was detected in Houhu areas. Surface subsidence time series presented nonlinear subsidence with pronounced seasonal variations. Comparative analysis of surface subsidence and influencing factors (i.e., urban construction, precipitation, industrial development, carbonate karstification and water level changes in Yangtze River indicated a relatively high spatial correlation between locations of subsidence bowl and those of engineering construction and industrial areas. Seasonal variations in subsidence were correlated with water level changes and precipitation. Surface subsidence in Wuhan was mainly attributed to anthropogenic activities, compressibility of soil layer, carbonate karstification, and groundwater overexploitation. Finally, the spatial-temporal characteristics of wide-area surface subsidence and the relationship between surface subsidence and influencing factors in Wuhan were determined.

  11. Differential subsidence in Mexico City and implications to its Collective Transport System (Metro). (United States)

    Solano Rojas, D. E.; Wdowinski, S.; Cabral-Cano, E.; Osmanoglu, B.


    Mexico City is one of the fastest subsiding metropolis in the world. At displacement rates ranging from 0 to -380 [mm/yr], the complex geological setting is subjected to differential subsidence, which has led to damage, operation interruptions, and accidents to the Collective Transport System, or Metro. The Metro plays a critical role in Mexico City, carrying more than four million passengers per day. However, no previous study has focused on the deformation monitoring along the 93 km of the Metro surface railways, mainly because of the limitations of the traditional geodetic techniques. In this study, we use high-resolution Interferometric Synthetic Aperture Radar (InSAR) observations to monitor land subsidence throughout the city and quantify differential subsidence along surface Metro lines. Our analysis is based on 34 TerraSAR-X StripMap scenes acquired from May 2011 to June 2013 and 36 COSMO-SkyMed Stripmap scenes acquired from June 2011 to June 2012. The data were processed using the StaMPS InSAR time series technique, obtaining point densities of up to 4827 points/km2. Our post-processing methodologies include the following two components: (1) Detection of differential subsidence along the metro lines by calculating subsidence gradients, and (2) Detection of apparent uplift—areas subsiding slower than their surroundings—by using spatial frequency filtering. The two analyses allow us to recognize four main consequences of differential subsidence in the Metro system: 1. Deflection in elevated railways, 2. Deflection in street-level railways, 3. Columns with decreased loading capacity, and 4. Apparent uplift affecting surrounding infrastructure. Our results aim at shortening the large gap between scientific geodetic studies and applicable engineering parameters that can be used by local authorities in the city for maintenance and new lines development.

  12. Subsidence monitoring with geotechnical instruments in the Mexicali Valley, Baja California, Mexico


    E. Glowacka; O. Sarychikhina; V. H. Márquez Ramírez; B. Robles; F. A. Nava; F. Farfán; M. A. García Arthur


    The Mexicali Valley (northwestern Mexico), situated in the southern part of the San Andreas fault system, is an area with high tectonic deformation, recent volcanism, and active seismicity. Since 1973, fluid extraction, from the 1500–3000 m depth range, at the Cerro Prieto Geothermal Field (CPGF), has influenced deformation in the Mexicali Valley area, accelerating the subsidence and causing slip along the traces of tectonic faults that limit the subsidence area. Detailed fi...

  13. Stress triggering of earthquakes and subsidence in the Louisiana coastal zone due to hydrocarbon production (United States)

    Mallman, Ellen P.

    This thesis presents contributions towards better understanding of the interaction between earthquakes through elastic stress triggering and the role of hydrocarbon production on subsidence and land loss in southern Louisiana. The first issue addressed in this thesis is that of the role of static stress changes on earthquake triggering. The first study investigated whether observed changes in seismicity rate following the 1992 Landers, California and 1995 Kobe, Japan earthquakes are accurately predicted by elastic Coulomb stress transfer models. The analyses found that for all the tested DeltaCFS models wherever seismicity rate changes could be resolved the rate increased regardless of whether the DeltaCFS theoretically promoted or inhibited failure. The second study the common definition of a stress shadow was extended to independently test the stress shadow hypothesis using a global catalog of seismicity. The analyses indicated that while stress shadows are subtle, they are present in the global catalog. It also explains why "classical" stress shadows, similar to what was observed following the 1906 San Francisco earthquake are rarely observed for individual main shocks. The second issue addressed in this thesis is the role of hydrocarbon production on subsidence and land loss in the Louisiana Coastal Zone. The two studies in this thesis extend previous work by modeling the effect of oil and gas production in the region in two ways. First, multiple producing oil and gas fields and multiple epochs of leveling data are considered to provide constraints on predicted subsidence. Second, the role of compaction of the reservoir bounding shales on the regional subsidence signal is included. The results of the two studies on the role of hydrocarbon production on subsidence in the Louisiana Coastal Zone indicate that regional models of subsidence must include the effects of production-induced subsidence due to both sands and shales, but that this can not account for the

  14. Reduced femoral component subsidence with improved impaction grafting at revision hip arthroplasty. (United States)

    Howie, D W; Callary, S A; McGee, M A; Russell, N C; Solomon, L B


    Despite stem subsidence being a major complication of femoral impaction bone grafting in cemented revision hip arthroplasty, few studies have distinguished subsidence at the prosthesis-cement interface from that at the cement-bone interface. It is unknown how technique developments intended to improve the procedure influence stability of the stem. We used a sensitive technique to measure subsidence of a cemented polished collarless double-taper stem at each interface after femoral impaction grafting and compared subsidence, radiographic loosening, complications, and reoperations over three series of hips defined by technique developments. Three series were defined: Series 1 (n = 23, irradiated allograft), Series 2 (n = 12, double-washed, size-profiled graft, nonirradiated bone, long stems as required), and Series 3 (n = 21, modular tamps). Stem subsidence was analyzed with Ein Bild Röntgen Analyse software. Radiographic loosening, complications, and reoperations were also determined. The median subsidence at 12 months for Series 1, 2, and 3 were 2.1, 0.5, and 0.7 mm at the prosthesis-cement interface and 1.3, 0.1, and 0.1 mm at the cement-bone interface. There were two postoperative Vancouver B periprosthetic fractures in Series 1, four hips were revised for loosening in Series 1, and there were no fractures or loosening in Series 2 and 3 at minimum 2 years' followup. There were no surviving hips radiographically classified as possibly or probably loose. Evolution in techniques of femoral impaction grafting in this study were associated with reduced subsidence of the stem at both the prosthesis-cement interface and cement-bone interface when compared to the original series. Concurrent with reduced stem subsidence was the absence of periprosthetic fracture, radiographic loosening, and complications requiring rerevision.

  15. Long-Term Land Subsidence Monitoring of Beijing (China Using the Small Baseline Subset (SBAS Technique

    Directory of Open Access Journals (Sweden)

    Bo Hu


    Full Text Available Advanced techniques of multi-temporal InSAR (MT-InSAR represent a valuable tool in ground subsidence studies allowing remote investigation of the behavior of mass movements in long time intervals by using large datasets of SAR images covering the same area and acquired at different epochs. Beijing is susceptible to subsidence, producing undesirable environmental impacts and affecting dense population. Excessive groundwater withdrawal is thought to be the primary cause of land subsidence, and rapid urbanization and economic development, mass construction of skyscrapers, highways and underground engineering facilities (e.g., subway are also contributing factors. In this paper, a spatial–temporal analysis of the land subsidence in Beijing was performed using one of the MT-InSAR techniques, referred to as Small Baseline Subset (SBAS. This technique allows monitoring the temporal evolution of a deformation phenomenon, via the generation of mean deformation velocity maps and displacement time series from a data set of acquired SAR images. 52 C-band ENVISAT ASAR images acquired from June 2003 to August 2010 were used to produce a linear deformation rate map and to derive time series of ground deformation. The results show that there are three large subsidence funnels within this study area, which separately located in Balizhuang-Dajiaoting in Chaoyang district, Wangjing-Laiguangying Chaoyang district, Gaoliying Shunyi district. The maximum settlement center is Wangsiying-Tongzhou along the Beijing express; the subsidence velocity exceeds 110 mm/y in the LOS direction. In particular, we compared the achieved results with leveling measurements that are assumed as reference. The estimated long-term subsidence results obtained by SBAS approach agree well with the development of the over-exploitation of ground water, indicating that SBAS techniques is adequate for the retrieval of land subsidence in Beijing from multi-temporal SAR data.

  16. Monitoring Mining Subsidence Using A Combination of Phase-Stacking and Offset-Tracking Methods

    Directory of Open Access Journals (Sweden)

    Hongdong Fan


    Full Text Available An approach to study the mechanism of mining-induced subsidence, using a combination of phase-stacking and sub-pixel offset-tracking methods, is reported. In this method, land subsidence with a small deformation gradient was calculated using time-series differential interferometric synthetic aperture radar (D-InSAR data, whereas areas with greater subsidence were calculated by a sub-pixel offset-tracking method. With this approach, time-series data for mining subsidence were derived in Yulin area using 11 TerraSAR-X (TSX scenes from 13 December 2012 to 2 April 2013. The maximum mining subsidence and velocity values were 4.478 m and 40 mm/day, respectively, which were beyond the monitoring capabilities of D-InSAR and advanced InSAR. The results were compared with the GPS field survey data, and the root mean square errors (RMSE of the results in the strike and dip directions were 0.16 m and 0.11 m, respectively. Four important results were obtained from the time-series subsidence in this mining area: (1 the mining-induced subsidence entered the residual deformation stage within about 44 days; (2 the advance angle of influence changed from 75.6° to 80.7°; (3 the prediction parameters of mining subsidence; (4 three-dimensional deformation. This method could be used to predict the occurrence of mining accidents and to help in the restoration of the ecological environment after mining activities have ended.

  17. Inverse modeling of interbed storage parameters using land subsidence observations, Antelope Valley, California (United States)

    Hoffmann, J.; Galloway, D.L.; Zebker, H.A.


    We use land-subsidence observations from repeatedly surveyed benchmarks and interferometric synthetic aperture radar (InSAR) in Antelope Valley, California, to estimate spatially varying compaction time constants, ??, and inelastic specific skeletal storage coefficients, Skv*, in a previously calibrated regional groundwater flow and subsidence model. The observed subsidence patterns reflect both the spatial distribution of head declines and the spatially variable inelastic skeletal storage coefficient. Using the nonlinear parameter estimation program UCODE we estimate compaction time constants between 3.8 and 285 years. The Skv* values are estimated by linear estimation and range from 0 to almost 0.09. We find that subsidence observations over long time periods are necessary to constrain estimates of the large compaction time constants in Antelope Valley. The InSAR data used in this study cover only a three-year period, limiting their usefulness in constraining these time constants. This problem will be alleviated as more SAR data become available in the future or where time constants are small. By incorporating the resulting parameter estimates in the previously calibrated regional model of groundwater flow and land subsidence we can significantly improve the agreement between simulated and observed land subsidence both in terms of magnitude and spatial extent. The sum of weighted squared subsidence residuals, a common measure of model fit, was reduced by 73% with respect to the original model. However, the ability of the model to adequately reproduce the subsidence observed over only a few years is impaired by the fact that the simulated hydraulic heads over small time periods are often not representative of the actual aquifer hydraulic heads. Errors in the simulated hydraulic aquifer heads constitute the primary limitation of the approach presented here.

  18. Evaluating Land Subsidence Rates and Their Implications for Land Loss in the Lower Mississippi River Basin

    Directory of Open Access Journals (Sweden)

    Lei Zou


    Full Text Available High subsidence rates, along with eustatic sea-level change, sediment accumulation and shoreline erosion have led to widespread land loss and the deterioration of ecosystem health around the Lower Mississippi River Basin (LMRB. A proper evaluation of the spatial pattern of subsidence rates in the LMRB is the key to understanding the mechanisms of the submergence, estimating its potential impacts on land loss and the long-term sustainability of the region. Based on the subsidence rate data derived from benchmark surveys from 1922 to 1995, this paper constructed a subsidence rate surface for the region through the empirical Bayesian kriging (EBK interpolation method. The results show that the subsidence rates in the region ranged from 1.7 to 29 mm/year, with an average rate of 9.4 mm/year. Subsidence rates increased from north to south as the outcome of both regional geophysical conditions and anthropogenic activities. Four areas of high subsidence rates were found, and they are located in Orleans, Jefferson, Terrebonne and Plaquemines parishes. A projection of future landscape loss using the interpolated subsidence rates reveals that areas below zero elevation in the LMRB will increase from 3.86% in 2004 to 19.79% in 2030 and 30.88% in 2050. This translates to a growing increase of areas that are vulnerable to land loss from 44.3 km2/year to 240.7 km2/year from 2011 to 2050. Under the same scenario, Lafourche, Plaquemines and Terrebonne parishes will experience serious loss of wetlands, whereas Orleans and Jefferson parishes will lose significant developed land, and Lafourche parish will endure severe loss of agriculture land.

  19. Model test on partial expansion in stratified subsidence during foundation pit dewatering (United States)

    Wang, Jianxiu; Deng, Yansheng; Ma, Ruiqiang; Liu, Xiaotian; Guo, Qingfeng; Liu, Shaoli; Shao, Yule; Wu, Linbo; Zhou, Jie; Yang, Tianliang; Wang, Hanmei; Huang, Xinlei


    Partial expansion was observed in stratified subsidence during foundation pit dewatering. However, the phenomenon was suspected to be an error because the compression of layers is known to occur when subsidence occurs. A slice of the subsidence cone induced by drawdown was selected as the prototype. Model tests were performed to investigate the phenomenon. The underlying confined aquifer was generated as a movable rigid plate with a hinge at one end. The overlying layers were simulated with remolded materials collected from a construction site. Model tests performed under the conceptual model indicated that partial expansion occurred in stratified settlements under coordination deformation and consolidation conditions. During foundation pit dewatering, rapid drawdown resulted in rapid subsidence in the dewatered confined aquifer. The rapidly subsiding confined aquifer top was the bottom deformation boundary of the overlying layers. Non-coordination deformation was observed at the top and bottom of the subsiding overlying layers. The subsidence of overlying layers was larger at the bottom than at the top. The layers expanded and became thicker. The phenomenon was verified using numerical simulation method based on finite difference method. Compared with numerical simulation results, the boundary effect of the physical tests was obvious in the observation point close to the movable endpoint. The tensile stress of the overlying soil layers induced by the underlying settlement of dewatered confined aquifer contributed to the expansion phenomenon. The partial expansion of overlying soil layers was defined as inversed rebound. The inversed rebound was induced by inversed coordination deformation. Compression was induced by the consolidation in the overlying soil layers because of drainage. Partial expansion occurred when the expansion exceeded the compression. Considering the inversed rebound, traditional layer-wise summation method for calculating subsidence should be

  20. Standardized Environmental Enrichment Supports Enhanced Brain Plasticity in Healthy Rats and Prevents Cognitive Impairment in Epileptic Rats (United States)

    Kouchi, Hayet Y.; Bodennec, Jacques; Morales, Anne; Georges, Béatrice; Bonnet, Chantal; Bouvard, Sandrine; Sloviter, Robert S.; Bezin, Laurent


    Environmental enrichment of laboratory animals influences brain plasticity, stimulates neurogenesis, increases neurotrophic factor expression, and protects against the effects of brain insult. However, these positive effects are not constantly observed, probably because standardized procedures of environmental enrichment are lacking. Therefore, we engineered an enriched cage (the Marlau™ cage), which offers: (1) minimally stressful social interactions; (2) increased voluntary exercise; (3) multiple entertaining activities; (4) cognitive stimulation (maze exploration), and (5) novelty (maze configuration changed three times a week). The maze, which separates food pellet and water bottle compartments, guarantees cognitive stimulation for all animals. Compared to rats raised in groups in conventional cages, rats housed in Marlau™ cages exhibited increased cortical thickness, hippocampal neurogenesis and hippocampal levels of transcripts encoding various genes involved in tissue plasticity and remodeling. In addition, rats housed in Marlau™ cages exhibited better performances in learning and memory, decreased anxiety-associated behaviors, and better recovery of basal plasma corticosterone level after acute restraint stress. Marlau™ cages also insure inter-experiment reproducibility in spatial learning and brain gene expression assays. Finally, housing rats in Marlau™ cages after severe status epilepticus at weaning prevents the cognitive impairment observed in rats subjected to the same insult and then housed in conventional cages. By providing a standardized enriched environment for rodents during housing, the Marlau™ cage should facilitate the uniformity of environmental enrichment across laboratories. PMID:23342033

  1. Standardized environmental enrichment supports enhanced brain plasticity in healthy rats and prevents cognitive impairment in epileptic rats.

    Directory of Open Access Journals (Sweden)

    Raafat P Fares

    Full Text Available Environmental enrichment of laboratory animals influences brain plasticity, stimulates neurogenesis, increases neurotrophic factor expression, and protects against the effects of brain insult. However, these positive effects are not constantly observed, probably because standardized procedures of environmental enrichment are lacking. Therefore, we engineered an enriched cage (the Marlau™ cage, which offers: (1 minimally stressful social interactions; (2 increased voluntary exercise; (3 multiple entertaining activities; (4 cognitive stimulation (maze exploration, and (5 novelty (maze configuration changed three times a week. The maze, which separates food pellet and water bottle compartments, guarantees cognitive stimulation for all animals. Compared to rats raised in groups in conventional cages, rats housed in Marlau™ cages exhibited increased cortical thickness, hippocampal neurogenesis and hippocampal levels of transcripts encoding various genes involved in tissue plasticity and remodeling. In addition, rats housed in Marlau™ cages exhibited better performances in learning and memory, decreased anxiety-associated behaviors, and better recovery of basal plasma corticosterone level after acute restraint stress. Marlau™ cages also insure inter-experiment reproducibility in spatial learning and brain gene expression assays. Finally, housing rats in Marlau™ cages after severe status epilepticus at weaning prevents the cognitive impairment observed in rats subjected to the same insult and then housed in conventional cages. By providing a standardized enriched environment for rodents during housing, the Marlau™ cage should facilitate the uniformity of environmental enrichment across laboratories.

  2. Resonance Spectra of Caged Stringy Black Hole and Its Spectroscopy

    Directory of Open Access Journals (Sweden)

    I. Sakalli


    quasinormal mode (QNM frequencies, is used to investigate the entropy/area spectra of the Garfinkle–Horowitz–Strominger black hole (GHSBH. Instead of the ordinary QNMs, we compute the boxed QNMs (BQNMs that are the characteristic resonance spectra of the confined scalar fields in the GHSBH geometry. For this purpose, we assume that the GHSBH has a confining cavity (mirror placed in the vicinity of the event horizon. We then show how the complex resonant frequencies of the caged GHSBH are computed using the Bessel differential equation that arises when the scalar perturbations around the event horizon are considered. Although the entropy/area is characterized by the GHSBH parameters, their quantization is shown to be independent of those parameters. However, both spectra are equally spaced.

  3. Magnetotactic Bacterial Cages as Safe and Smart Gene Delivery Vehicles

    KAUST Repository

    Alsaiari, Shahad K.


    In spite of the huge advances in the area of synthetic carriers, their efficiency still poorly compares to natural vectors. Herein, we report the use of unmodified magnetotactic bacteria as a guidable delivery vehicle for DNA functionalized gold nanoparticles (AuNPs). High cargo loading is established under anaerobic conditions (bacteria is alive) through endocytosis where AuNPs are employed as transmembrane proteins mimics (facilitate endocytosis) as well as imaging agents to verify and quantify loading and release. The naturally bio-mineralized magnetosomes, within the bacteria, induce heat generation inside bacteria through magnetic hyperthermia. Most importantly after exposing the system to air (bacteria is dead) the cell wall stays intact providing an efficient bacterial vessel. Upon incubation with THP-1 cells, the magnetotactic bacterial cages (MBCs) adhere to the cell wall and are directly engulfed through the phagocytic activity of these cells. Applying magnetic hyperthermia leads to the dissociation of the bacterial microcarrier and eventual release of cargo.

  4. CAGE Analysis of China’s Trade Globalization

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    Emmanuel Olusegun STOBER


    Full Text Available Gravity model of international trade states that trade interaction between two countries is in direct proportion to their size measured by Gross Domestic Product and in inverse proportion to the geographic distance. Conley and Ligon (2001 argued that the relevant economic distance between countries is often not the geographic distance. Thus, this study uses original datasets on economic distance to structure observed variations, to decompose the multidimensional CAGE distance framework of globalization derived from the Newton’s Law of gravitation as it applies to China’s international interaction, to evaluate bilateral trade patterns in identifying and prioritizing the importance of cross-border flows and differences that accounted for the development of China’s global strategies. This study confirms that distance must be accounted for in the decision making of any country’s globalization process or any firm’s global expansion as the effects on cross-border economic activities are enormous.

  5. Gaiola de metabolismo para equinos Metabolism cage for horses

    Directory of Open Access Journals (Sweden)

    Dorinha Miriam Silber Schmidt Vitti


    Full Text Available A gaiola de metabolismo, modelo proposto neste trabalho, foi construida na Seção de Oficina da FCAV-Unesp, Jaboticabal-SP e utilizada no Laboratório de Ciências Animais do Cena-USP, Piracicaba-SP. Este equipamento permite alojar eqüinos machos com idade a partir do desmame. Os animais foram treinados (condicionados diariamente a permanecer na gaiola de metabolismo por um período de aproximadamente 30 dias antes do início do experimento. O material necessário e a construção de uma gaiola metabólica para eqüinos machos é descrita e ilustrada. A estrutura principal da gaiola (2,68 m de comprimento x 0,80 m de largura x 2,02 m de altura é constituida por canos de metal de duas polegadas e todas as unidades de apoio - tábuas do piso, grade de urina, bebedouro, comedouro, bandeja coletora de urina e barras de contenção - estão fixas à estrutura principal de modo a serem removidas desta, faciltando o manejo e a limpeza do equipamento. O equipamento foi projetado para alojar animais de vários tamanhos e também para ser efetiva na coleta total de fezes e urina e no fornecimento de alimento e água. Os animais permaneceram em pé durante todo o período de confinamento, sem contudo ter havido a ocorrência de edemas graves nos membros. O modelo proposto foi testado em experimentos de metabolismo de fósforo utilizando-se radioisótopos.The metabolism cage here proposed was built at FCAV-Unesp, Jaboticabal, state of São Paulo, Brazil, and used in the Animal Science Laboratory at Cena-USP, Piracicaba, state of São Paulo, Brazil. The equipment allows to host male horses from weaning to adult age. Before starting the experiment, the animals were daily conditioned for a 30-day period to remain in the cage. The necessary material and the building process of the horse metabolic cage are described and illustrated. The main structure of the cage (2.68m long x 0.80 m wide x 2.02 m high was made of 2-inch-diameter metal tube, and all the

  6. Chemistry and Biology of the Caged Garcinia Xanthones (United States)

    Chantarasriwong, Oraphin; Batova, Ayse; Chavasiri, Warinthorn


    Natural products have been a great source of many small molecule drugs for various diseases. In spite of recent advances in biochemical engineering and fermentation technologies that allow us to explore microorganisms and the marine environment as alternative sources of drugs, more than 70% of the current small molecule therapeutics derive their structures from plants used in traditional medicine. Natural-product-based drug discovery relies heavily on advances made in the sciences of biology and chemistry. Whereas biology aims to investigate the mode of action of a natural product, chemistry aims to overcome challenges related to its supply, bioactivity, and target selectivity. This review summarizes the explorations of the caged Garcinia xanthones, a family of plant metabolites that possess a unique chemical structure, potent bioactivities, and a promising pharmacology for drug design and development. PMID:20648491

  7. Performance Analysis of a Brushless Double Fed Cage Induction Generator

    Energy Technology Data Exchange (ETDEWEB)

    Ruencos, F. [WEG S.A., Jaragua do Sul (Brazil); Carlson, R.; Oliveira, A.M.; Kuo-Peng, P.; Sadowski, N. [GRUCAD-UFSC, Florianopolis (Brazil)


    This paper analyses design and performance aspects of a brushless double fed cage induction generator as an economic and technical alternative to the classical wound rotor induction generator used in wind power generation. It focuses firstly on the machine operational characteristics and main design criteria and secondly on steady state and dynamic analytical and numerical models for efficient prediction of machine behavior. The analytical dynamic model is obtained by transforming the equations written in machine variables into equations written in an arbitrary reference frame. In the finite element approach the electrical machine is modeled in a 2D domain, using the Maxwell equations to formulate the field behavior and the FE method to discretize the domain of study. A prototype was built and tested to validate the simulation models and to verify the design criteria.

  8. Ecoenvironment characteristics of subsidence lakes in coal mine areas and ways to harness them

    International Nuclear Information System (INIS)

    Bian Zhengfu; Zhang Guoliang; Lin Jiacong


    With the increase in coal output, the environment in coal mine areas, especially land destruction, has become increasingly worse. A main form of land destruction is subsidence lakes, which have disrupted people's lives and coal production and which change the ecological system of mine areas into water-land type or aquatic system. Two conditions forming subsidence lakes are surface subsidence and high phreatic level. The ratio of waterlogging in China's eastern coal mine areas is higher than that of other areas because of high phreatic level, and eastern mine areas are agriculture-based at the same time. It is a fact that the structure and function of an ecological system after mining is different from that before mining. It is not a good way to resume the original structure and function of the ecological system. Therefore, before harnessing subsidence lakes, it is necessary that their ecoenvironment characteristics be investigated thoroughly, then new structure and function of ecology affected by coal mining and ways to harness subsidence lakes are posed. These ways include: subsidence lakes used as fly ash, coal waste and other wastes deposit, land reclamation by raising the shallow land with digging the deep, recreating new aquatic ecosystem, etc

  9. An Analysis Model for Water Cone Subsidence in Bottom Water Drive Reservoirs (United States)

    Wang, Jianjun; Xu, Hui; Wu, Shucheng; Yang, Chao; Kong, lingxiao; Zeng, Baoquan; Xu, Haixia; Qu, Tailai


    Water coning in bottom water drive reservoirs, which will result in earlier water breakthrough, rapid increase in water cut and low recovery level, has drawn tremendous attention in petroleum engineering field. As one simple and effective method to inhibit bottom water coning, shut-in coning control is usually preferred in oilfield to control the water cone and furthermore to enhance economic performance. However, most of the water coning researchers just have been done on investigation of the coning behavior as it grows up, the reported studies for water cone subsidence are very scarce. The goal of this work is to present an analytical model for water cone subsidence to analyze the subsidence of water cone when the well shut in. Based on Dupuit critical oil production rate formula, an analytical model is developed to estimate the initial water cone shape at the point of critical drawdown. Then, with the initial water cone shape equation, we propose an analysis model for water cone subsidence in bottom water reservoir reservoirs. Model analysis and several sensitivity studies are conducted. This work presents accurate and fast analytical model to perform the water cone subsidence in bottom water drive reservoirs. To consider the recent interests in development of bottom drive reservoirs, our approach provides a promising technique for better understanding the subsidence of water cone.

  10. Resistance to subsidence of an uncemented femoral stem after cerclage wiring of a fissure. (United States)

    McCulloch, Ryan S; Roe, Simon C; Marcellin-Little, Denis J; Mente, Peter L


    To compare: (1) the force required to initiate subsidence, and (2) the relative subsidence, of femoral stems implanted into intact femora, and then into the same femora in which an induced fissure had been stabilized by cerclage. In vitro, mechanical study. Femora (n=9) from 9 dogs. Femora were prepared for implantation of an uncemented stem. Stems were implanted with continuous and impact loading. After axial loading until a fissure occurred, the stems were extracted, and the fissure stabilized with double-loop cerclage. Stems were reimplanted, and reloaded to failure. Mean±SD load to initiate subsidence in intact femora was 1706±584 N compared with 2379±657 N for cerclaged bones (P=.002). Mean relative subsidence of intact femora was 3.99±2.09 mm compared with 1.79±2.99 mm for cerclaged bones (P=.091). The load to initiate subsidence is increased in femora that have fissured, then have been stabilized with double-loop cerclage, when compared with intact femora. The relative subsidence is not different between intact and stabilized specimens. © Copyright 2011 by The American College of Veterinary Surgeons.

  11. The impact of subsidence on straight and curved modular cementless revision stems in hip revision surgery. (United States)

    Fraile Suari, A; Gil González, S; Pérez Prieto, D; León García, A; Mestre Cortadellas, C; Tey Pons, M; Marqués López, F

    Subsidence is one of the potential complications in femoral stem revision total hip arthroplasty surgery, and can affect stability and osseointegration. A retrospective study was conducted on the outcomes at one year and 5 years (specifically subsidence and clinical relevance) of 40 consecutive femoral total hip arthroplasty revisions, comparing two modular cementless revision stems, Straight vs. Curved, with 20 patients in each group. No mechanical failure was observed, and there was an improvement in functional outcomes. Mean radiological subsidence was 9.9±4.9mm (straight=10.75mm vs. curved=9.03mm), with no statistically significant difference between groups (p=0,076). Fourteen patients (35%) had ≥10mm of subsidence, up to a maximum of 22mm. The subsidence found in this study is similar to published series, with no short-term clinical manifestations, or an increased number of complications or stem loosening in either the Straight or Curved group. No differences in subsidence were observed at one year and 5 years after surgery between the 2 types of stems. Copyright © 2017 SECOT. Publicado por Elsevier España, S.L.U. All rights reserved.

  12. Inter- and intrarater reliability of ulna variance versus lunate subsidence measurements in Madelung deformity. (United States)

    Farr, Sebastian; Bae, Donald S


    To assess inter- and intrarater reliability of both ulna variance and lunate subsidence measurement methods in a large consecutive series of children with Madelung deformity. Ulnar variance and lunate subsidence were measured on 41 standard anteroposterior wrist radiographs from 31 patients with Madelung deformity. The patients had a mean age of 13 years (range, 5-25) at the time of presentation. Two pediatric orthopedic hand/upper limb surgeons evaluated all radiographs twice in a 4-week interval using standard digital imaging software. Intraclass correlation coefficients (ICCs) were calculated for inter- and intrarater reliability, and results were reported using the Landis and Koch criteria. The interrater ICC for the ulna variance measurements was substantial, and for the lunate subsidence almost perfect. The intrarater ICC for ulna variance was substantial for both raters. In contrast, the intrarater ICC for lunate subsidence was almost perfect for both raters. Measurement of lunate subsidence showed both superior interrater and intrarater reliability compared with the ulnar variance method. Whenever relative ulna length is assessed in children and adolescents with Madelung deformity, the lunate subsidence should be the preferred method to characterize deformity. Copyright © 2015 American Society for Surgery of the Hand. Published by Elsevier Inc. All rights reserved.

  13. Differences in subsidence rate between alternative designs of a commonly used uncemented femoral stem. (United States)

    Al-Najjim, Munnan; Khattak, Usman; Sim, Juluis; Chambers, Iain


    Measurement of early subsidence of uncemented femoral stems can be used to evaluate the likelihood of long term stem component loosening and therefore clinical failure. Our aim was to evaluate the factors associated with subsidence in collared and uncollared versions of the Corail femoral stem. 121 hips in 113 consecutive patients were studied, operated on by two surgeons in our hospital differing in their choice of Corail stem. This gave two groups of patients with 66 hips having collared stems and 55 hips having uncollared. We recorded patients' age, sex, ASA grade and BMI. Radiographs post-operatively at day 1, 6 weeks and 1 year were evaluated measuring subsidence, angulation, signs of stability and fixation, and canal fill ratio at the metaphysis and diaphysisafter correcting for magnification errors by calibration using femoral head size. Clinically significant subsidence (>3 mm) occurred in 7.6% of collared and 10.9% of uncollared stems, all within 6-8 weeks, but did not reach statistical significance (p = 0.345). Revision for symptomatic loosening was required in 1 patient in each group (1.5% collared versus 1.8% uncollared). Early subsidence of Corail femoral stem should alert surgeons to closer patient follow-up as the rate of early revision is 18% in stems with >3 mm of subsidence. However, the presence of a collar does not seem to be protective.

  14. Radiographic Subsidence in Asymptomatic Patients After THR Using the Furlong Active HAP Stem. (United States)

    Cordero-Ampuero, José; Peñalver, Pablo; Antón, Rodrigo; Galán, María; Cordero, Enrique


    The short, tapered, collarless Furlong Active stem has been recently associated in the published literature with significant subsidence using Roentgen stereophotogrammetric analysis. The purpose of this study was to analyze the short-term radiographic subsidence in Furlong Active HAP stems and correlate the results with the age, gender, bone morphology, and bone quality of the proximal femur, stem diameter, and medullary canal filling. Sixty-five consecutive patients (70 hips) receiving the Furlong Active HAP stems were enrolled in this prospective series. The average follow-up was 2.99 ± 1.38 years. All patients were evaluated clinically using the Harris Hip Score (HHS) and radiographically for femoral stem subsidence. In addition, proximal femoral osteopenia, proximal femur morphology, and medullary canal filling were also evaluated. The average subsidence was 2.4 mm (from 0 to 13 mm) at the end of the follow-up period. The average HHS score at the end of follow-up was 90 (range, 81-98). There was one intraoperative fracture. Of the Furlong Active stems 61% subsided with initial weight bearing. Subsidence is higher in males, but no correlation has been found with age, stem diameter, morphology, osteopenia, or canal filling.

  15. Land subsidence characteristics of the Bandung Basin, Indonesia, as estimated from GPS and InSAR (United States)

    Abidin, H. Z.; Andreas, H.; Gamal, M.; Wirakusumah, A. D.; Darmawan, D.; Deguchi, T.; Maruyama, Y.


    The Bandung Basin is a large intra-montane basin surrounded by volcanic highlands, in western Java, Indonesia, inhabited by more than five million people. Based on the results of five GPS surveys conducted in February 2000, November 2001, July 2002, June 2003, and June 2005, it can be concluded that for the period of 2000 to 2005 several locations in the Bandung Basin have experienced land subsidence. Over this 5-year period land subsidence in a few locations reached a magnitude of about 70 cm, with a subsidence speed of about 1-2 cm/month. A similar rate of subsidence was also detected by the InSAR (Interferometric Synthetic Aperture Radar) technique during the period between June 2006 and March 2007. The statistical testing showed no strong correlation between GPS-derived land subsidence and registered groundwater extraction during the period of February 2000 to July 2002. The InSAR technique, however, detected significant subsidence in the textile industry area, which very large volumes of groundwater are usually extracted.

  16. Modeling and zoning of land subsidence in the southwest of Tehran using artificial neural networks

    Directory of Open Access Journals (Sweden)

    M. Pishro


    Full Text Available The earth's surface, due to its natural conditions and its structure is always changing and reshaping. One of the created deformations is the land subsidence. This is the most dangerous events which can be seen in most urban areas especially in the agricultural plains today. This study aims at zoning land subsidence and recognition of geometrical factors in southwest of Tehran. To estimate and predict land subsidence, all the effective subsidence factors were identified. Among the factors, nine most important factors including, downfall of groundwater, thickness of clay, depth of groundwater, annual discharge of water from wells, the distance of well to each other, slop, elevation, land use and geology were evaluated. Ultimately, three variables were selected as the most important variables. For modeling and zoning these factors, artificial neural network using Matlab software and Arc-GIS software for creating primary layers were used. The results indicate that the main cause of subsidence is excessive removal of underground water resources. Since the use of water resources in agriculture is accounted for the highest percentage of consumption and also because a large part of the study area have an agriculture land use, therefore the underground water drop and agricultural land uses are the most susceptible areas of land subsidence occurrence.

  17. Estimated land-surface subsidence in Harris County, Texas, 1915-17 to 2001 (United States)

    Kasmarek, Mark C.; Gabrysch, Robert K.; Johnson, Michaela R.


    Land-surface subsidence, or land subsidence, in Harris County, Texas, which encompasses much of the Houston area, has been occurring for decades. Land subsidence has increased the frequency and extent of flooding, damaged buildings and transportation infrastructure, and caused adverse environmental effects. The primary cause of land subsidence in the Houston area is withdrawal of groundwater, although extraction of oil and gas also has contributed. Throughout most of the 20th century, groundwater was the primary source of municipal, agricultural, and industrial water supply for Harris County. Currently (2009) a transition to surface water as the primary source of supply, guided by a groundwater regulatory plan developed by the Harris-Galveston Subsidence District (2001), is in effect. The aquifers in Harris County contain an abundant amount of potable groundwater, but they also contain layers of clay. Groundwater withdrawals caused compaction of the clay layers, which in turn resulted in the widespread, substantial land-surface subsidence that has occurred in the Houston area.

  18. Risk Mapping of Groundwater-Drawdown-Induced Land Subsidence in Heterogeneous Soils on Large Areas. (United States)

    Sundell, Jonas; Haaf, Ezra; Norberg, Tommy; Alén, Claes; Karlsson, Mats; Rosén, Lars


    Groundwater leakage into subsurface constructions can cause reduction of pore pressure and subsidence in clay deposits, even at large distances from the location of the construction. The potential cost of damage is substantial, particularly in urban areas. The large-scale process also implies heterogeneous soil conditions that cannot be described in complete detail, which causes a need for estimating uncertainty of subsidence with probabilistic methods. In this study, the risk for subsidence is estimated by coupling two probabilistic models, a geostatistics-based soil stratification model with a subsidence model. Statistical analyses of stratification and soil properties are inputs into the models. The results include spatially explicit probabilistic estimates of subsidence magnitude and sensitivities of included model parameters. From these, areas with significant risk for subsidence are distinguished from low-risk areas. The efficiency and usefulness of this modeling approach as a tool for communication to stakeholders, decision support for prioritization of risk-reducing measures, and identification of the need for further investigations and monitoring are demonstrated with a case study of a planned tunnel in Stockholm. © 2017 The Authors Risk Analysis published by Wiley Periodicals, Inc. on behalf of Society for Risk Analysis.

  19. Six years of land subsidence in shanghai revealed by JERS-1 SAR data (United States)

    Damoah-Afari, P.; Ding, X.-L.; Li, Z.; Lu, Z.; Omura, M.


    Differential interferometric synthetic aperture radar (SAR) (DInSAR) has proven to be very useful in mapping and monitoring land subsidence in many regions of the world. Shanghai, China's largest city, is one of such areas suffering from land subsidence as a result of severe withdrawal of groundwater for different usages. DInSAR application in Shanghai with the C-band European Remote Sensing 1 & 2 (ERS-1/2) SAR data has been difficult mainly due to the problem of decorrelation of InSAR pairs with temporal baselines larger than 10 months. To overcome the coherence loss of C-band InSAR data, we used eight L-band Japanese Earth Resource Satellite (JERS-1) SAR data acquired during 2 October 1992 to 15 July 1998 to study land subsidence phenomenon in Shanghai. Three of the images were used to produce two separate digital elevation models (DEMs) of the study area to remove topographic fringes from the interferograms used for subsidence mapping. Six interferograms were used to generate 2 different time series of deformation maps over Shanghai. The cumulative subsidence map generated from each of the time series is in agreement with the land subsidence measurements of Shanghai city from 1990-1998, produced from other survey methods. ?? 2007 IEEE.

  20. Hydraulic cage concept for waste chambers and its technical implementation for the underground Richard repository, Litomerice, Czech Republic

    International Nuclear Information System (INIS)

    Haverkamp, B.; Biurrun, E.; Mueller-Hoeppe, N.; Kucerka, Miroslav


    Richard Repository is a near surface underground repository for low and intermediate level radioactive waste of institutional origin. In the course of a joint Phare Project carried out together with the repository operator, the Czech Radioactive Waste Repository Authority (RAWRA), DBE Technology developed a new concept for the closure of individual waste chambers. Main technological element of this concept is the installation of a hydraulic cage around the waste chambers by attaching a gravel layer to all sides of the chamber. This hydraulic cage will prevent the development of advective flow through the waste/concrete body within the backfilled chambers by eliminating the pressure gradient as driving force for such a flow. Thus the transport of radionuclides will be restricted to diffusive fluxes, which results in a considerable decrease of potential radiological impact. In the course of the project the closure of a certain chamber system within the mine was planned up to a grade of detail, which allowed its direct realization as a pilot closure study, which started in the beginning of 2006. (author)