SLOPE DEFORMATION MONITORING USING REFLECTOR-LESS TOTAL STATION

Continuous deformation monitoring of slope along the roads and highways in Malaysia is one of the most effective method of early landslide detection, which could contribute to avoiding or reducing the risk of landslide. There are many factors that influence the success of the monitoring system such as accuracy of the instruments, existing information, frequency of slope failure in a particular area, size of potential hazard area and the involvement of people in that project. To overcome the above problems Reflector-less Total Station method is introduced as an alternative method. This method is able to reduce the usage of reflectors, thus more survey points can be covered. It is also more economical since not only the costs for the prisms are saved, but high installation expenses can also be reduced. Additionally it can lower the risk to the people involved in measuring slope deformation in areas that are dangerous and difficult to access. This research focuses on the potential of using reflector-less Total Station for slope deformation monitoring. In order to check the performance and reliability of the reflector-less Total Station, periodical calibration of the instrument is necessary. The instrument with its related reflectors is calibrated to verify its constant and scaling errors, which is often accomplished by calculation from a series of measurements on a calibration baseline. A parametric least squares formula was used to obtain the constant and scaling correction calculations based on the series of distances on six sub-baselines. The calibration was performed at Jabatan Ukur dan Pemetaan Malaysia (JUPEM) permanent calibration benchmarks at Batu Gajah, Perak Malaysia. The result shows that the values of the constant and scaling corrections for the prism and the various targets are less than the values of the instrument specification, which indicate that the reflector-less Total Station is functioning well. Data on slope deformation monitoring were collected for the three epochs within a six months gap of each other and were carried out independently in the study area located at chainage 23+800 at Simpang Pulai - Cameron Highland highway. To prove that the movement is significant, statistical test has been adopted in this study using t-student distribution. The test results show that there is a significant movement in the study area, whereby there has been a maximum of 0.09 m in the northing, 0.08 m in the easting and 0.012 m in the elevation in some of the points during the 18 months observation period

SLOPE DEFORMATION MONITORING USING REFLECTOR-LESS TOTAL STATION

Continuous deformation monitoring of slope along the roads and highways in Malaysia is one of the most effective method of early landslide detection, which could contribute to avoiding or reducing the risk of landslide. There are many factors that influence the success of the monitoring system such as accuracy of the instruments, existing information, frequency of slope failure in a particular area, size of potential hazard area and the involvement of people in that project. To overcome the above problems Reflector-less Total Station method is introduced as an alternative method. This method is able to reduce the usage of reflectors, thus more survey points can be covered. It is also more economical since not only the costs for the prisms are saved, but high installation expenses can also be reduced. Additionally it can lower the risk to the people involved in measuring slope deformation in areas that are dangerous and difficult to access. This research focuses on the potential of using reflector-less Total Station for slope deformation monitoring. In order to check the performance and reliability of the reflector-less Total Station, periodical calibration of the instrument is necessary. The instrument with its related reflectors is calibrated to verify its constant and scaling errors, which is often accomplished by calculation from a series of measurements on a calibration baseline. A parametric least squares formula was used to obtain the constant and scaling correction calculations based on the series of distances on six sub-baselines. The calibration was performed at Jabatan Ukur dan Pemetaan Malaysia (JUPEM) permanent calibration benchmarks at Batu Gajah, Perak Malaysia. The result shows that the values of the constant and scaling corrections for the prism and the various targets are less than the values of the instrument specification, which indicate that the reflector-less Total Station is functioning well. Data on slope deformation monitoring were collected for the three epochs within a six months gap of each other and were carried out independently in the study area located at chainage 23+800 at Simpang Pulai - Cameron Highland highway. To prove that the movement is significant, statistical test has been adopted in this study using t-student distribution. The test results show that there is a significant movement in the study area, whereby there has been a maximum of 0.09 m in the northing, 0.08 m in the easting and 0.012 m in the elevation in some of the points during the 18 months observation period

A Dependence of the Tidal Disruption Event Rate on Global Stellar Surface Mass Density and Stellar Velocity Dispersion

© 2018. The American Astronomical Society. All rights reserved. The rate of tidal disruption events (TDEs), R TDE , is predicted to depend on stellar conditions near the super-massive black hole (SMBH), which are on difficult-to-measure sub-parsec scales. We test whether R TDE depends on kpcscale global galaxy properties, which are observable. We concentrate on stellar surface mass density, ∑ M∗ , and velocity dispersion, σ v , which correlate with the stellar density and velocity dispersion of the stars around the SMBH. We consider 35 TDE candidates, with and without known X-ray emission. The hosts range from starforming to quiescent to quiescent with strong Balmer absorption lines. The last (often with post-starburst spectra) are overrepresented in our sample by a factor of 35 +21 -17 or 18 +8 -7 , depending on the strength of the Hδ absorption line. For a subsample of hosts with homogeneous measurements, ∑ M∗ = 10 9 -10 10 M ⊙ /kpc 2 , higher on average than for a volume-weighted control sample of Sloan Digital Sky Survey galaxies with similar redshifts and stellar masses. This is because (1) most of the TDE hosts here are quiescent galaxies, which tend to have higher ∑ M∗ than the star-forming galaxies that dominate the control, and (2) the star-forming hosts have higher average ∑ M∗ than the star-forming control. There is also a weak suggestion that TDE hosts have lower σ v than for the quiescent control. Assuming that R TDE ∝ ∑ M∗ α × σ v β , and applying a statistical model to the TDE hosts and control sample, we estimate α = 0.9 ; 0.2 and β = -1.0 0.6. This is broadly consistent with RTDE being tied to the dynamical relaxation of stars surrounding the SMBH

Bangladesh arsenic mitigation programs: lessons from the past

Ensuring access to safe drinking water by 2015 is a global commitment by the Millennium Development Goals (MDGs). In Bangladesh, significant achievements in providing safe water were made earlier by nationwide tubewell-installation programme. This achievement was overshadowed in 1993 by the presence of arsenic in underground water. A total of 6 million tubewells have been tested for arsenic since then, the results of which warranted immediate mitigation. Mitigation measures included tubewell testing and replacing; usage of deeper wells; surface water preservation and treatment; use of sanitary dug wells, river sand and pond sand filters; rainwater collection and storage; household-scale and large-scale arsenic filtrations; and rural pipeline water supply installation. Shallow tubewell installation was discouraged. Efforts have been made to increase people's awareness. This paper describes the lessons learned about mitigation efforts by the authors from experience of arsenic-related work. In spite of national mitigation plans and efforts, a few challenges still persist: inadequate coordination between stakeholders, differences in inter-sectoral attitudes, inadequate research to identify region-specific, suitable safe water options, poor quality of works by various implementing agencies, and inadequate dissemination of the knowledge and experiences to the people by those organizations. Issues such as long-time adaptation using ground water, poor surface water quality including bad smell and turbidity, and refusal to using neighbor's water have delayed mitigation measures so far. Region-specific mitigation water supply policy led by the health sector could be adopted with multisectoral involvement and responsibility. Large-scale piped water supply could be arranged through Public Private Partnerships (PPP) in new national approach

Tribological characteristics comparison of formulated palm trimethylolpropane ester and polyalphaolefin for cam/tappet interface of direct acting valve train system

Purpose There is a continuous drive in automotive sector to shift from conventional lubricants to environmental friendly ones without adversely affecting critical tribological performance parameters. Because of their favorable tribological properties, chemically modified vegetable oils such as palm trimethylolpropane ester (TMP) are one of the potential candidates for the said role. To prove the suitability of TMP for applications involving boundary-lubrication regime such as cam/tappet interface of direct acting valve train system, a logical step forward is to investigate their compatibility with conventional lubricant additives. Design/methodology/approach In this study, extreme pressure and tribological characteristics of TMP, formulated with glycerol mono-oleate (GMO), molybdenum dithiocarbamate (MoDTC) and zinc dialkyldithiophosphate (ZDDP), has been investigated using four-ball wear tester and valve train test rig. For comparison, additive-free and formulated versions of polyalphaolefin (PAO) were used as reference. Moreover, various surface characterization techniques were deployed to investigate mechanisms responsible for a particular tribological behavior. Findings In additive-free form, TMP demonstrated better extreme pressure characteristics compared to PAO and lubricant additives which are actually optimized for conventional base-oils such as PAO, are also proved to be compatible with TMP to some extent, especially ZDDP. During cylinder head tests, additive-free TMP proved to be more effective compared to PAO in reducing friction of cam/tappet interface, but opposite behavior was seen when formulated lubricants were used. Therefore, there is a need to synthesize specialized friction modifiers, anti-wear and extreme pressure additives for TMP before using it as engine lubricant base-oil. Originality/value In this study, additive-free and formulated versions of bio-lubricant are tested for cam/tappet interface of direct acting valve train system of commercial passenger car diesel engine for the very test time. Another important aspect of this research was comparison of important tribological performance parameters (friction torque, wear, rotational speed of tappet) of TMP-based lubricants with conventional lubricant base oil, that is, PAO and its formulated version

Uncoupling human and climate drivers of late Holocene vegetation change in southern Brazil

In the highlands of southern Brazil an anthropogenitcally driven expansion of forest occurred at the expense of grasslands between 1410 and 900cal BP, coincident with a period of demographic and cultural change in the region. Previous studies have debated the relative contributions of increasing wetter and warmer climate conditions and human landscape modifcations to forest expansion, but generally lacked high resoltiuon proxies to measure these efects, or have relied on single proxies to reconstruct both climate and vegetation. Here, we develop and test a model of natural ecosystem distribution against vegetation histories, paleoclimate proxies, and the archaeological record to distinguish human from temperature and precipitation impacts on the distribution and expansion of Araucaria forests during the late Holocene. Carbon isotopes from soil profles confrm that in spite of climatic fuctuations, vegetation was stable and forests were spatially limited to south-facing slopes in the absence of human inputs. In contrast, forest management strategies for the past 1400 years expanded this economically important forest beyond its natural geographic boundaries in areas of dense pre-Columbian occupation, suggesting that landscape modifcations were linked to demographic changes, the efects of which are still visible today

Marine resource abundance drove pre-agricultural population increase in Stone Age Scandinavia

How climate and ecology affect key cultural transformations remains debated in the context of long-term socio-cultural development because of spatially and temporally disjunct climate and archaeological records. The introduction of agriculture triggered a major population increase across Europe. However, in Southern Scandinavia it was preceded by ~500 years of sustained population growth. Here we show that this growth was driven by long-term enhanced marine production conditioned by the Holocene Thermal Maximum, a time of elevated temperature, sea level and salinity across coastal waters. We identify two periods of increased marine production across trophic levels (P1 7600–7100 and P2 6400–5900 cal. yr BP) that coincide with markedly increased mollusc collection and accumulation of shell middens, indicating greater marine resource availability. Between ~7600–5900 BP, intense exploitation of a warmer, more productive marine environment by Mesolithic hunter-gatherers drove cultural development, including maritime technological innovation, and from ca. 6400–5900 BP, underpinned a ~four-fold human population growth

Properties of galaxies reproduced by a hydrodynamic simulation.

Previous simulations of the growth of cosmic structures have broadly reproduced the 'cosmic web' of galaxies that we see in the Universe, but failed to create a mixed population of elliptical and spiral galaxies, because of numerical inaccuracies and incomplete physical models. Moreover, they were unable to track the small-scale evolution of gas and stars to the present epoch within a representative portion of the Universe. Here we report a simulation that starts 12 million years after the Big Bang, and traces 13 billion years of cosmic evolution with 12 billion resolution elements in a cube of 106.5 megaparsecs a side. It yields a reasonable population of ellipticals and spirals, reproduces the observed distribution of galaxies in clusters and characteristics of hydrogen on large scales, and at the same time matches the 'metal' and hydrogen content of galaxies on small scales

Intraperitoneal drain placement and outcomes after elective colorectal surgery: international matched, prospective, cohort study

Despite current guidelines, intraperitoneal drain placement after elective colorectal surgery remains widespread. Drains were not associated with earlier detection of intraperitoneal collections, but were associated with prolonged hospital stay and increased risk of surgical-site infections.Background Many surgeons routinely place intraperitoneal drains after elective colorectal surgery. However, enhanced recovery after surgery guidelines recommend against their routine use owing to a lack of clear clinical benefit. This study aimed to describe international variation in intraperitoneal drain placement and the safety of this practice. Methods COMPASS (COMPlicAted intra-abdominal collectionS after colorectal Surgery) was a prospective, international, cohort study which enrolled consecutive adults undergoing elective colorectal surgery (February to March 2020). The primary outcome was the rate of intraperitoneal drain placement. Secondary outcomes included: rate and time to diagnosis of postoperative intraperitoneal collections; rate of surgical site infections (SSIs); time to discharge; and 30-day major postoperative complications (Clavien-Dindo grade at least III). After propensity score matching, multivariable logistic regression and Cox proportional hazards regression were used to estimate the independent association of the secondary outcomes with drain placement. Results Overall, 1805 patients from 22 countries were included (798 women, 44.2 per cent; median age 67.0 years). The drain insertion rate was 51.9 per cent (937 patients). After matching, drains were not associated with reduced rates (odds ratio (OR) 1.33, 95 per cent c.i. 0.79 to 2.23; P = 0.287) or earlier detection (hazard ratio (HR) 0.87, 0.33 to 2.31; P = 0.780) of collections. Although not associated with worse major postoperative complications (OR 1.09, 0.68 to 1.75; P = 0.709), drains were associated with delayed hospital discharge (HR 0.58, 0.52 to 0.66; P < 0.001) and an increased risk of SSIs (OR 2.47, 1.50 to 4.05; P < 0.001). Conclusion Intraperitoneal drain placement after elective colorectal surgery is not associated with earlier detection of postoperative collections, but prolongs hospital stay and increases SSI risk