ANATOMICAL CHANGES IN Urochloa plantaginea AND Urochloa platyphylla UNDER DIFFERENT SOIL MOISTURE CONDITIONS

Urochloa plantaginea and Urochloa platyphylla are common weeds in the highland area. However, in recent years, they have been found in wetlands and poorly drained soils, but the biology and behavior of the species in these conditions are not known. Thus, the objective was to assess anatomical changes in plants of Urochloa plantaginea and Urochloa platyphylla grown under different soil moisture conditions, as well as the adaptive structures generated as a result of each environment. A completely randomized experimental design in the form of a 2x2 factorial design was used, with factor A being two species of Urochloa (U. plantaginea and U. platyphylla), and species B being three soil moisture conditions (50 and 100% FC and 5 cm water depth), with four repetitions. The assessments were performed by means of anatomical cuts, observing the number and diameter (micrometers - μm) of aerenchymas in stems, roots and leaves; total diameter and the central root cylinder (μm); diameter of the fistula medulla and cortex (μm) in stems; mesophyll thickness and leaf midrib (μm). It was found that, for the two species of Urochloa, the water depth condition induced an increase in the number and diameter of aerenchymas in roots and leaves and provided a larger diameter of the fistulous pith in stems. The diameter of the central cylinder and the thickness of the leaf mesophyll midrib were more compact at 50% FC, also, for both species. Therefore, the adaptive structures generated vary as a result of the field capacity of the soil.

Taking aim at the perceptual side of motor learning: Exploring how explicit and implicit learning encode perceptual error information through depth vision

Motor learning in visuomotor adaptation tasks results from both explicit and implicit processes, each responding differently to an error signal. While the motor output side of these processes is extensively studied, their visual input side is relatively unknown. We investigated if and how depth perception affects the computation of error information by explicit and implicit motor learning. Two groups of participants threw virtual darts at a virtual dartboard while receiving perturbed endpoint feedback. The Delayed group was allowed to re-aim and their feedback was delayed to emphasize explicit learning, while the Clamped group received clamped cursor feedback which they were told to ignore, and continued to aim straight at the target to emphasize implicit adaptation. Both groups played this game in a highly detailed virtual environment (Depth condition) and in an empty environment (No-Depth condition). The Delayed group showed an increase in error sensitivity under Depth relative to No-Depth conditions. In contrast, the Clamped group adapted to the same degree under both conditions. The movement kinematics of the Delayed participants also changed under the Depth condition, consistent with the target appearing more distant, unlike the Clamped group. A comparison of the Delayed behavioral data with a perceptual task from the same individuals showed that the effect of the Depth condition on the re-aiming direction was consistent with an increase in the scaling of the error distance and size. These findings suggest that explicit and implicit learning processes may rely on different sources of perceptual information.

Taking aim at the perceptual side of motor learning: Exploring how explicit and implicit learning encode perceptual error information through depth vision

Motor learning in visuomotor adaptation tasks results from both explicit and implicit processes, each responding differently to an error signal. While the motor output side of these processes is extensively studied, their visual input side is relatively unknown. We investigated if and how depth perception affects the computation of error information by explicit and implicit motor learning. Two groups of participants threw virtual darts at a virtual dartboard while receiving perturbed endpoint feedback. The Delayed group was allowed to re-aim and their feedback was delayed to emphasize explicit learning, while the Clamped group received clamped cursor feedback which they were told to ignore, and continued to aim straight at the target to emphasize implicit adaptation. Both groups played this game in a highly detailed virtual environment (Depth condition) and in an empty environment (No-Depth condition). The Delayed group showed an increase in error sensitivity under Depth relative to No-Depth conditions. In contrast, the Clamped group adapted to the same degree under both conditions. The movement kinematics of the Delayed participants also changed under the Depth condition, consistent with the target appearing more distant, unlike the Clamped group. A comparison of the Delayed behavioral data with a perceptual task from the same individuals showed that the effect of the Depth condition on the re-aiming direction was consistent with an increase in the scaling of the error distance and size. These findings suggest that explicit and implicit learning processes may rely on different sources of perceptual information.New & NoteworthyWe leveraged a classic sensorimotor adaptation task to perform a first systematic assessment of the role of perceptual cues in the estimation of an error signal in the 3D space during motor learning. We crossed two conditions presenting different amounts of depth information, with two manipulations emphasizing explicit and implicit learning processes. Explicit learning responded to the visual conditions, consistent with perceptual reports, while implicit learning appeared to be independent of them.

ANALISIS APLIKASI STRUKTUR TRUSS BERPENAMPANG MELINTANG SEGITIGA UNTUK JEMBATAN JALAN RAYA

Truss structure which is often used for primary girder of bridge of highway is a Warren or Pratt type, what is its use combined with two horizontal truss attached below and above functioning as truss of wind bracing. Though have space dimension, but its structure is not pure of truss space, practically its analysis is done to each truss, vertical and horizontal which is considered as plane truss. Truss structure with a trianggular cross section type represent other alternative from structure truss which can is also used as a highway bridge structure, and this type truss represent purification truss space. Beside that, structurally entire element truss together have the contribution to arrest forced from all direction, and cause this type truss is more stable in arrest torsion and shear compared to a other structure truss bridge type. Method used to analyse structure of truss that is stiffness matrix method by means of assist calculation of Microsoft Excel 2007. Result to be reached from this analysis is to find relation of between span length, depth of truss and to the number of panel, to weight of structure and translation of a joint; utilize to get optimum weight and translation of joint. Pursuant to result analyse to three group of sample truss model, each group consisted of three sample, in each depth condition of certain truss, there's only one optimum weight value at one particular truss, and angle of inclination of diagonal and also the span-depth ratio and depth of economic truss still stay in gyration of economic values is such as those which applied for plane truss

Analisis Luas dan Volume Sedimen pada Kanal Intake untuk Menjaga Ketersediaan Pasokan Air (Studi Kasus : PLTGU Muara Tawar, Bekasi Utara)

ABSTRAKPLTGU Muara Tawar merupakan salah satu pembangkit listrik yang menggunakan air laut untuk proses pendinginannya. Air laut tersebut disalurkan melalui kanal intake di mana sedimen yang berada di kanal intake akan mempengaruhi pasokan air. Untuk itu dalam menjaga ketersediaan pasokan air pada kanal intake perlu diketahui luas dan volume sedimennya. Penelitian ini bertujuan untuk mengetahui drying height pada saat air terendah, pola penyebaran sedimen, perubahan luas sedimen, kondisi kedalaman kritis, dan perubahan volume air dan sedimen antara Maret 2013 dan Desember 2014. Data yang digunakan berupa data posisi permukaan sedimen dan pasut pada Bulan Maret-April 2013 dan Desember 2014. Pada tahun 2013 didapatkan informasi bahwa pasokan air yang tersedia hanya 32,75% sementara di tahun 2014 hanya 32,69% dari syarat aman. Dengan demikian untuk memenuhi syarat aman pasokan air maka sedimen sampai 6 meter di bawah MSL yang harus dikeruk baik di tahun 2013 maupun 2014 sebesar lebih dari 60%.Kata kunci: kanal intake, sedimen, pasokan airABSTRACTPLTGU Muara Tawar is one of the power plants that use sea water as a coolant. The sea water is channeled through the intake canal where sediments in it will affect the water supply. For maintaining the water supply in intake canal it is necesssary to have an information about sediment area and volume. This study schemes are to determine the drying height at lowest low water, sediment distribution, changes in sediment area, critical depth condition, and changes in the volume and sediment beetween March 2013 and December 2014. The data used are the position of the sediment surface and the tide height on March to April 2013 and Desember 2014. It is obtained that for safety requirements the water supply left only 32,75% in 2013 and reduced to 32,69% in 2014. So, to achieve the safety requirements of water supply in 2013 and 2014 the sediment ought to be dredged more than 60% from 6 meter below MSL base.Keywords: intake canal, sediment, water supply

CHARACTERISATION OF BREAKING WAVES ON THE EDDYSTONE LIGHTHOUSE: A LABORATORY INVESTIGATION ON WAVE PRESSURE

Commonly, rock lighthouses are erected on the top of steep reefs and in limited water depths. The effect of these environmental conditions on wave loading requires deeper understanding. This paper investigates wave loading at small scale for a particular case study: the Eddystone lighthouse (UK). Load characteristics due to breaking waves are obtained by the use of pressure transducers and the test program is designed to generate a comprehensive data set covering a broader range of wave conditions. Although the magnitude of wave pressures is rather random from wave to wave of the same train of regular waves, the pressure impulsivity tends to decrease with increasing relative breaking distance. Four breaker types are described and particular attention is given to time histories of the line of action of horizontal force and vertical spatial distributions. Estimation of overall forces, obtained by pressure integration, indicates that the wave loading is strongly affected by the limited water depth condition. In fact, only small plunging waves are able to break at the structure; thus, they cause small forces despite the small breaking distances. Finally, the occurrence of the breakers is investigated on a dimensionless plane given by the combination of the Iribarren number and momentum flux of Hughes.

Application of PANDA and Geo-Endoscopy Techniques for Improved Assessment of Track Substructure Conditions at Railroad Bridge Approaches

An advanced technology for measuring track substructure conditions has been developed by Sol Solution in France. This technology, referred to as the PANDA® and Geo-Endoscopy® technique, comprises driving a variable energy cone penetration device into the track substructure using an instrumented anvil to collect strength (and modulus by correlation) profile with depth. Condition monitoring of the track substructure layers is accomplished through insertion of a camera into the same hole, also called Geoendoscopy®. The tests are commonly faster than Dynamic Cone Penetration (DCP) testing and cause negligible damage to the track substructure with the use of light and portable devices. This paper presents data from PANDA® and Geo-Endoscopy® testing efforts recently carried out under the scope of an ongoing research study at the University of Illinois. The primary objective was to relate the substructure layer properties to plastic layer deformations measured through advanced geotechnical instrumentation. Combined analysis of the PANDA®, Geo-Endoscopy®, and field instrumentation data has been used to highlight the reliability of this innovative technique towards improved evaluation of track substructure layer conditions.