Abstract Seepage monitoring of slopes is a basic requirement for evaluating slope stability and is necessary for predicting landslides. In this paper, an innovative Distributed Temperature System for measuring seepage rate, called S-DTS, is introduced. In S-DTS, a Carbon Fiber Heating Cable, called CFHC, is designed and made for enhancing the measure sensitivity and accuracy of DTS for seepage monitoring; a characteristic temperature ( T t ) is proposed and defined for establishing the quantitative relationship between the measured temperature value and the seepage rate ( V ) easily. A test is designed and carried out to validate the feasibility of this technology in measuring the seepage rate quantitatively. The test results show that T t has a good linear relationship between with the seepage rate ( V ), but nothing with the grain size distribution in same sandy soil. Finally, an S-DTS based seepage monitoring program of slope is presented. S-DTS can be used to monitor the fluctuation of the groundwater table and seepage rate in the slope, and to locate the position of potential slip surfaces in slopes. It has great significance to assess the slope stability and predict the landslide. Highlights • A DTS for seepage monitoring is introduced (called S-DTS). • An innovative carbon fiber heating cable is developed. • A characteristic temperature ( T t ) is defined. • A quantitative relationship between T t and seepage rate ( V ) is established. • A test is carried out to verify the feasibility of S-DTS for seepage monitoring.
Abstract Fiber reinforcement is an effective method for improving engineering properties of soil. However, the interaction mechanism of the fiber and the surrounding soil is not well understood. Based on mechanical analysis of fiber-soil interface under pullout condition, a tri-linear model is proposed to describe the shear stress-displacement relationship. The progressive pullout process of a short fiber in soil is divided into five consecutive phases: (1) the initial pure elastic phase (Phase I); (2) the elastic-softening phase (Phase II); (3) the pure softening phase (Phase III); (4) the softening-residual phase (Phase IV); and (5) the final pure residual phase (Phase V). For each phase, the analytical solutions of the distributions of tensile force, interfacial shear stress and displacement are derived. Through a comparison between the pullout test results of polypropylene fiber (PP-fiber) and the predicted results, the effectiveness of the proposed model in capturing the progressive load-deformation behavior of a short fiber in soil is verified. Moreover, the effects of water content and dry density of soil on the model parameters are analyzed in detail. It is found that the interfacial peak/residual shear resistance and shear stiffness of fiber reinforced soil significantly depend on soil compaction conditions. In general, two transition phases (Phase II and Phase IV) are not evident during the whole pullout process of PP-fiber.
Graphical abstract Abstract Catalyst Ni/attapulgite powder (AP) was facilely prepared by thermally decomposing nickel tetracarbonyl onto AP. Anthracene was used as a condensed arenes (CAs)-related model compound to evaluate the catalytic activity and selectivity of Ni/AP for hydrogenating CAs. The results show that anthracene can be completely converted to perhydroanthracenes (PHAs) at 175 °C and selectively converted to 9,10-dihydroanthracene (DHA, ca. 86.4%) at 300 °C by catalytic hydrogenation over Ni/AP. Ni/AP effectively promotes the formation and transfer (F & T) of biatomic active hydrogen (H⋯H) at 175 °C, resulting in the complete hydrogenation of anthracene to PHAs. The mechanism for the F & T of H⋯H is consistent with the observation from the higher selectivities of cis- PHAs than that of trans- PHAs. At 300 °C, the catalytically produced H⋯H over Ni/AP tends to be homolytically spitted to hydrogen radical (H ), inducing the partial hydrogenation of anthracene to DHA. Quantum chemical calculations based on density functional theory further confirmed the temperature-controlled hydrogenation of anthracene over Ni/AP. This finding is a conclusive proof that the active hydrogen species is crucially important for affecting the product selectivities from the catalytic hydrogenation of anthracene over Ni/AP. Our research also offers a novel strategy for highly selective conversion of CAs to polycyclic alkanes or hydroarenes.
Sunday Folaranmi Akogun
Graphical abstract Through complexation of naphthalenediol-based bis(Salamo)-type tetraoxime compound H 4 L with Zn(OAc) 2 ·2H 2 O, a novel chemosensor ([Zn 3 (L)( μ -OAc) 2 (H 2 O) 2 ]) for detection of Pic − , was obtained and characterized. Highlights • H 4 L is a novel naphthalenediol-based bis(Salamo)-type tetraoxime compound. • H 4 L is a relay-sensor for high sensitive and selective detection of Zn 2+ /Pic − . • The H 4 L has two on/off switch fluorescence chains. • Both of the H 4 L and L-Zn 2+ chemosensors have a certain practical application value and advantage. Abstract A novel naphthalenediol-based bis(Salamo)-type tetraoxime compound (H 4 L) was synthesized and characterized. Its Zn 2+ complex was found to be highly sensitive for the detection of Pic − when dissolved in water-containing organic solvent. Sensor H 4 L acts as a relay-sensor for recognition of Zn 2+ while the L-Zn 2+ complex recognizes Pic − with high selectivity and sensitivity in acceptable physiological pH range. Moreover, The L-Zn 2+ and its Pic − polymer complex display successive sensing of H + /OH − via increase (ON) and decrease (OFF) in fluorescence intensity. The crystal structure of the Zn 2+ complex has been determined by single-crystal X-ray diffraction.
PURPOSE The indication for laparoscopic total or partial adrenalectomy in patients with aldosterone producing adrenal adenoma remains controversial. We compared retroperitoneoscopic partial and total adrenalectomy for aldosterone producing adrenal adenoma in a prospective, randomized, multicenter trial. MATERIALS AND METHODS Patients with aldosterone producing adrenal adenoma were randomized to retroperitoneoscopic partial or total adrenalectomy. Patient characteristics, surgical data, complications and postoperative clinical results were analyzed statistically. RESULTS From July 2000 to March 2004, 212 patients were enrolled in this study, including 108 and 104 who underwent total and partial adrenalectomy, respectively. The 2 groups were comparable in patient age, gender, body mass index and tumor site. Mean followup was 96 months in each group. No conversion to open surgery was needed and no major complications developed. Partial adrenalectomy required a shorter operative time than total adrenalectomy but this did not attain statistical significance. Intraoperative blood loss in the partial adrenalectomy group was significant higher than in the total adrenalectomy group (p <0.05) but no patient needed blood transfusion. All patients in each group showed improvement in hypertension, and in all plasma renin activity and aldosterone returned to normal after surgery. No patient required potassium supplements postoperatively. In the total and partial adrenalectomy groups 32 (29.6%) and 29 patients (27.9%), respectively, were prescribed a decreased dose of or fewer antihypertensive medicines at final followup. CONCLUSIONS Retroperitoneoscopic partial adrenalectomy is technically safe. It has therapeutic results similar to those of total adrenalectomy in patients with primary aldosteronism due to aldosteronoma.
"Wavelength tunable electro-absorption modulated distributed Bragg reflector lasers (TEMLs) are promising light source in dense wavelength division multiplexing (DWDM) optical fiber communication system due to high modulation speed； small chirp； low drive voltage； compactness and fast wavelength tuning ability. Thus； increased the transmission capacity； the functionality and the flexibility are provided. Materials with bandgap difference as large as 250nm have been integrated on the same wafer by a combined technique of selective area growth (SAG) and quantum well intermixing (QWI)； which supplies a flexible and controllable platform for the need of photonic integrated circuits (PIC). A TEML has been fabricated by this technique for the first time. The component has superior characteristics as following: threshold current of 37mA； output power of 3.5mW at 100mA injection and 0V modulator bias voltage； extinction ratio of more than 20 dB with modulator reverse voltage from 0V to 2V when coupled into a single mode fiber； and wavelength tuning range of 4.4nm covering 6 100-GHz WDM channels. A clearly open eye diagram is observed when the integrated EAM is driven with a 10-Gb/s electrical NRZ signal. A good transmission characteristic is exhibited with power penalties less than 2.2 dB at a bit error ratio (BER) of 10-10 after 44.4 km standard fiber transmission."
The User Requirements Notation (URN)； standardized by the International Telecommunication Union in 2008； is used to model and analyze requirements with goals and scenarios. This paper describes the first ten years of development of URN； and discusses ongoing efforts targeting the next ten years. We did a study inspired by the systematic literature review approach； querying five major search engines and using the existing URN Virtual Library. Based on the 281 scientific publications related to URN we collected and analyzed； we observe a shift from a more conventional use of URN for telecommunications and reactive systems to business process management and aspect-oriented modeling； with relevant extensions to the language being proposed. URN also benefits from a global and active research community； although industrial contributions are still sparse. URN is now a leading language for goal-driven and scenario-oriented modeling with a promising future for many application domains.
Laparoscopic adrenalectomy has become the gold-standard for the surgical treatment of most adrenal lesions. This study evaluated the operative outcome of laparoendoscopic single-site (LESS) retroperitoneoscopic adrenalectomy (LESS-ARA) in comparison with the current standard operation procedure. Between June and December 2009, 19 patients underwent LESS-ARA, and their outcomes were compared with a contemporary 1:2 matched-pair cohort of 38 patients who underwent standard ARA by the same surgeon. In LESS-ARA, a multichannel port was inserted through a 2.5- to 3.0-cm transverse skin incision below the tip of the 12th rib. The LESS-ARA procedure was performed using a 5-mm 30º laparoscopic camera and two standard laparoscopic instruments. The following parameters were compared between the two groups: demographics, details of the surgery, perioperative complications, postoperative visual analog pain scale score, analgesic requirement, and short-term measures of convalescence. The finding showed that LESS-ARA and standard ARA were comparable in terms of the estimated blood loss (30 vs 17.5 ml； p = 0.64), postoperative hospital stay (6 vs 6 days； p = 0.67), and postoperative complications (2 vs 3 patients； p = 1.00) for patients with similar baseline demographics and median tumor size (2.1 vs 3.0； p = 0.18) cm. The intraoperative hemodynamic values were similar in the two groups. The LESS-ARA group had a longer median operative time (55 vs 41.5 min； p = 0.0004), whereas the in-hospital use of analgesics was significantly less (5 vs 12 morphine equivalents； p = 0.03). The LESS retroperitoneoscopic adrenalectomy approach is feasible and offers a superior cosmetic outcome and better pain control, with perioperative outcomes and short-term measures of convalescence similar to those of the standard approach, albeit with a longer operative time.