Studi Pengaruh Gerak Semi-submersible Drilling Rig Dengan Variasi Pre-tension Mooring Line Terhadap Keamanan Drilling Riser

Analisis terhadap sistem tambat pada anjungan pengeboran semi-submersible drilling rig perlu dilakukan sebelum dilakukannya operasi di lapangan untuk mengetahui perencanaan sistem tambat yang tepat dan aman. Dalam penelitian ini dilakukan analisa perilaku gerak semi-submersible dengan variasi pre-tension mooring line untuk mengetahui berapa besar pre-tension minimal yang harus digunakan agar operasi pengeboran di lingkungan laut Natuna dapat berjalan dengan aman. Variasi pre-tension yang digunakan adalah sebesar 400kN-2000kN dengan penambahan sebesar 400kN. Karakteristik gerakan semi-submersible diprediksi dengan menghitung RAO free floating dengan pemodelan numerik dalam domain frekuensi. Kemudian dilakukan analisa simulasi sistem lengkap (platform, mooring dan drilling riser) dengan pemodelan numerik dalam domain waktu. Hasil yang didapat yakni nilai maksimum tegangan mooring line memenuhi batas kriteria API-RP2SK untuk semua variasi pre-tension dengan safety factor terkecil 2.44. Sudut flex joint drilling riser yang terjadi melewati batas kriteria API-RP16Q pada pre-tension 400kN-800kN yang mencapai 6.20 untuk sudut maksimum dan 4.80 untuk sudut rata-rata. Tegangan von Mises yang terjadi pada drilling riser melebihi kriteria API-RP16Q pada pre-tension 400kN-1200kN karena nilainya mencapai 369 MPa (0.82 yield stress)

Hybrid State Space-based Learning for Sequential Data Prediction with Joint Optimization

We investigate nonlinear prediction/regression in an online setting and introduce a hybrid model that effectively mitigates, via a joint mechanism through a state space formulation, the need for domain-specific feature engineering issues of conventional nonlinear prediction models and achieves an efficient mix of nonlinear and linear components. In particular, we use recursive structures to extract features from raw sequential sequences and a traditional linear time series model to deal with the intricacies of the sequential data, e.g., seasonality, trends. The state-of-the-art ensemble or hybrid models typically train the base models in a disjoint manner, which is not only time consuming but also sub-optimal due to the separation of modeling or independent training. In contrast, as the first time in the literature, we jointly optimize an enhanced recurrent neural network (LSTM) for automatic feature extraction from raw data and an ARMA-family time series model (SARIMAX) for effectively addressing peculiarities associated with time series data. We achieve this by introducing novel state space representations for the base models, which are then combined to provide a full state space representation of the hybrid or the ensemble. Hence, we are able to jointly optimize both models in a single pass via particle filtering, for which we also provide the update equations. The introduced architecture is generic so that one can use other recurrent architectures, e.g., GRUs, traditional time series-specific models, e.g., ETS or other optimization methods, e.g., EKF, UKF. Due to such novel combination and joint optimization, we demonstrate significant improvements in widely publicized real life competition datasets. We also openly share our code for further research and replicability of our results.Comment: Submitted to the IEEE TNNLS journa

Volume CVI, Number 10, January 13, 1989

WOS: 000188054500005Two subspecies of mistletoe (Viscum album L. ssp. album and ssp. abietis) growing on lime and pine trees, respectively, were investigated for the monosaccharides and polyols by GC-MS spectrometry. Arabinose, xylose, glucose, galactose, mannose, xylitol and inositol were determined in methanol extracts following the acidic hydrolysis. Sugar contents of the leaves were expressed as percentage on dry weight. Xylose content was the same (1.5%) in each species, whereas the other saccharides varied. V. album ssp. abietis (collected from pine trees) were found containing significantly higher percentage of glucose (29.0%) and galactose (44.0%) than V. album ssp. album (collected from lime trees) (9.0% and 17.0%, respectively). In contrast, mannose, arabinose and sugar alcohol percentages were higher in ssp. album. Mannose content was 3.5% for ssp. album whereas 1.0% for ssp. abietis. 3.0% arabinose were determined in the former and 2.0% in the latter. Xylitol and inositol percentages were 8.0% and 58.0% for ssp. album and 1.5% and 21.0% for ssp. abietis, respectively. These results indicate that saccharide composition of mistletoes depends upon the subspecies of the plant and the host tree

Fibroadenoma of ectopic breast tissue of the axilla in an adolescent girl: Report of a rare entity

Ectopic breast tissue (EBT) is a well-described entity in the English  literature. However, fibroadenoma of the ectopic breast is a rare entity. We present a case of a 13-year-old adolescent girl with a subcutaneous mass in the right axilla that was pathologically identical to fibroadenoma seen in the EBT. To our knowledge, this is the second youngest patient reported with axillary EBT, which should be considered as a part of the differential diagnosis for axillary masses. Keywords: adolescent, axilla, ectopic breast tissue, fibroadenoma, mass Departments of aPediatric Surgery, bPathology, Sami Ulus Maternity and Children’s Hospital and cDepartment of Reproductive Endocrinology, Zubeyde Hanım Women Health Hospital, Ankara, Turke

Exact Spin and Pseudo-Spin Symmetric Solutions of the Dirac-Kratzer Problem with a tensor potential via Laplace Transform Approach

Exact bound state solutions of the Dirac equation for the Kratzer potential in the presence of a tensor potential are studied by using the Laplace transform approach for the cases of spin- and pseudo-spin symmetry. The energy spectra is obtained in the closed form for the relativistic as well as non-relativistic cases including the Coulomb potential. It is seen that our analytical results are in agrement with the ones given in literature. The numerical results are also given in a table for different parameter values.Comment: 8 page

Evaluating the predictive value of quantec rectum tolerance dose suggestions on acute rectal toxicity in prostate carcinoma patients treated with IMRT

AimTo investigate the predictive value of convenience of rectum dosimetry with Quantitative Analysis of Normal Tissue Effects in the Clinic (QUANTEC) dose limits, maximum rectum dose (Dmax), total rectal volume (TVrectum), rectal volume included in PTV (VrectumPTV) on Grade 2–3 acute rectal toxicity for utilization in clinical practice.BackgroundNumerous previous data have reported frequent acute proctitis after external-beam RT of prostate cancer. Predicting toxicity limited with dose information is inadequate in clinical practice due to comorbidities and medications used.Materials and MethodSixty-four non-metastatic prostate cancer patients treated with IMRT were enrolled. Patients were treated to a total dose of 70–76Gy. Rectal dose volume histograms (DVH) of all patients were evaluated retrospectively, and a QUANTEC Score between 0 and 5 was calculated for each patient. The correlation between the rectal DVH data, QUANTEC score, TVrectum, VrectumPTV, rectum Dmax and Grade 2–3 rectal toxicity was investigated.ResultsIn the whole group grade 1, 2 and 3 acute rectal toxicities were 25%, 18.8% and 3.1%, respectively. In the DVH data, rectum doses of all patients were under RTOG dose limits. Statistically significant correlation was found between grade 2–3 rectal toxicity and TVrectum (p=0,043); however. It was not correlated with QUANTEC score, VrectumPTV and Dmax.ConclusionOur results were not able to show any significant correlation between increasing convenience with QUANTEC limits and lower rectal toxicity. Conclusively, new dosimetric definitions are warranted to predict acute rectal toxicity more accurately in prostate cancer patients during IMRT treatment

3-D crustal structure along the North Anatolian Fault Zone in north-central Anatolia revealed by local earthquake tomography

3-D P-wave velocity structure and Vp/Vs variations in the crust along the North Anatolian Fault Zone (NAFZ) in north-central Anatolia were investigated by the inversion of local P- and S-wave traveltimes, to gain a better understanding of the seismological characteristics of the region. The 3-D local earthquake tomography inversions included 5444 P- and 3200 S-wave readings obtained from 168 well-located earthquakes between 2006 January and 2008 May. Dense ray coverage yields good resolution, particularly in the central part of the study area. The 3-D Vp and Vp/Vs tomographic images reveal clear correlations with both the surface geology and significant tectonic units in the region. We observed the lower limit of the seismogenic zone for north-central Anatolia at 15 km depth. Final earthquake locations display a distributed pattern throughout the study area, with most of the earthquakes occurring on the major splays of the NAFZ, rather than its master strand. We identify three major high-velocity blocks in the mid-crust separated by the Izmir-Ankara-Erzincan Suture and interpret these blocks to be continental basement fragments that were accreted onto the margin following the closure of Neo-Tethyan Ocean. These basement blocks may have in part influenced the rupture propagations of the historical 1939, 1942 and 1943 earthquakes. In addition, large variations in the Vp/Vs ratio in the mid-crust were observed and have been correlated with the varying fluid contents of the existing lithologies and related tectonic structures

A relational view of environmental performance: What role do environmental collaboration and cross-functional alignment play?

Despite extensive research into the role played by social capital and relational capability in attaining interorganizational advantage, the way in which these resources matter for environmental performance has received scant attention. We investigate how firms' social capital and relational capability influence their environmental performance, by analyzing the mediating role of environmental collaboration and the moderating role of crossfunctional alignment. Based on an analysis of dual responses from 270 Turkish firms, we find that environmental collaboration mediates the impact of social capital and relational capability on environmental performance. We also find that alignment between marketing and supply chain management functions strengthens the effects of relational capability and environmental collaboration on environmental performance. Our study suggests that both environmental collaboration and cross-functional alignment are necessary if the true value of social capital and relational capability for environmental performance is to be realized.Q2WOS:0004575123000042-s2.0-8505614829