The role of the surveyor

The surveyor provides guidance and assistance for cargo protection, besides ensuring that the palm, palm kernel and coconut oils conform to the contractual requirements. This involves quality and quantity check, inspection of storage facilities, conveying systems and transport vehicles and supervision of loading and discharge operations. Usually, the surveyor’s findings form the basis for settlement of the transaction. With the ever-developing technology customer requirements have become more and more sophisticated, and consequently the need for complex and sophisticated service is considerably increasing. In order to achieve the desired objective the surveyor, besides being neutral and reliable, must be endowed with adequate technical know-how and facilities. There are quite a few pitfalls that can occur during the course of manufacture, handling, transportation, transfer points, etc., and in order to prevent them, the surveyor should conduct a series of checks at various points to ensure that the quality of the oil is not affected. Adequate precautions and timely corrective measures would evidently ensure this requirement. Quality check is equally essential, with need for a well-equipped testing laboratory with accurate instruments, controlled and managed by adequately qualified and experienced chemists with the knowledge of updated technology. The surveyor can also assist in arbitration, insurance claims, general, commercial and maritime information, as his opinions and recommendations are unbiased, reliable and accurate, which helps make decision-making a less difficult task. Besides the buyer and seller, the surveyor also protects the interests of the financier, under-writer, shipowners and in certain cases the government departments.     

The occurrence of a furanoid fatty acid inHevea brasiliensis latex

Methyl esters from the triglyceride fraction of the neutral lipids of natural rubber latex were found by gas liquid chromatography to contain about 90% of a furanoid acid. Spectroscopic analysis identified the acid as 10,13-epoxy-11-methyloctadeca-10,12-dienoic acid.     

Ultrasonic assessment of early-age changes in the material properties of cementitious materials

After casting, cementitious materials exhibit a continuous change in the mechanical properties with time due to a chemical reaction known as hydration. In addition, these materials also exhibit a change in state, from a fluid to a solid, in the first few hours. Conventionally, changes in the material properties are obtained by monitoring the visco-elastic moduli with time before setting and the increase in the elastic material properties of the solid cementitious material, after setting. An ultrasonic test setup and the data analysis procedures, which provide for continuous monitoring of the hydrating cementitious materials from a very early age through setting are presented in this paper. The test procedures for obtaining the ultrasonic test data and the inversion subroutines for assessing the material properties of the cementitious material at different stages of hydration are discussed. The experimental test results obtained from mortar mixtures of varying compositions are presented. The observed experimental trends are explained considering wave propagation in visco-elastic materials. There is a two-stage increase in the value of shear modulus of mortar with time. Experimental evidence suggests that initially there is a larger relative increase in the viscous component of the shear modulus while later there is a larger relative increase in the elastic component.     

Analysis of Scaling and Instability in FRP-Concrete Shear Debonding for Beam-Strengthening Applications

The debonding mode of failure, which is observed in girders strengthened using externally attached fiber-reinforced polymer (FRP) sheets, is studied in this paper. A numerical analysis of the direct-shear response of FRP attached to concrete substrate is performed to study the initiation, formation, and propagation of an interfacial crack between the two adherents. The material response of the bimaterial interface, which includes postpeak softening, is incorporated into the numerical model. The load response obtained numerically is shown to be in close agreement with that determined experimentally from direct shear tests on concrete blocks strengthened with FRP sheets. An instability in the load response is predicted close to failure and the arc-length method is used to obtain the entire load response past the displacement-limit point. The instability in the load response is shown to be a result of snapback, where both the load and the displacement decrease simultaneously. The effect of the bonded length on the stress transfer between the FRP and concrete and on the ultimate failure is also analyzed. It is shown that there is a scaling in the load capacity when the bonded length does not allow for the establishment of the full stress-transfer zone associated with interface crack growth. From the results of the numerical analysis, a fundamental understanding of interfacial crack propagation and instability at failure in concrete members strengthened using externally bonded FRP is developed. Using a simple energy based formulation; it is shown that in strengthened girders, the instability at complete debonding of FRP from concrete translates into an explosive failure associated with a sudden release of energy.     

Miniaturization of low cycle fatigue‐testing of single crystal superalloys at high temperature for uncoated and coated specimens

A newly developed miniature specimen and respective fixture for high temperature low cycle fatigue testing of nickel based single crystal superalloys is presented. Miniaturization allows the preparation of test specimens in all main crystallographic orientations of the cubic nickel crystal using laboratory sized material samples and enables excellent utilization of the costly material. The specimen geometry is optimized by means of parameter studies employing numerical calculations such that for the main crystallographic orientations the stress concentration at the fillet between gauge length and specimen head is minimized, and failure is likely to occur within the gauge length. The designed fixture allows easy specimen mounting and provides sufficient support for applying an extensometer for strain measurement. Protective metallic coatings against oxidation can be applied on the specimen by plasma spraying for studying the effect of coatings on the fatigue lifetime. The functionality of the specimen geometry and fixture design for low cycle fatigue testing is demonstrated for temperatures up to 950 °C.     

Direct observation of nanomechanical properties of chromatin in living cells

Precise manipulation of nanometer-sized magnetic particles using magnetic tweezers has yielded insights into the rheology of the cell cytoplasm. We present first results using this approach to study the nanomechanics of the cell nucleus. Using a custom-designed micro-magnetic-tweezers instrument, we can achieve sufficiently high magnetic forces enabling the application and measurement of controlled distortion of the internal nuclear structure on the nanometer scale. We precisely measure the elasticity and viscosity inside the nucleus of living HeLa cells. The high value of the Young's modulus (Y = 2.5 x 10(2) Pa) measured relative to the cytoplasm is explained by a large-scale model for in vivo chromatin structure using a polymer network model.     

Carbon nanotubes grown on stainless steel to form plate and probe electrodes for chemical/biological sensing

This paper describes the fabrication and evaluation of carbon nanotube (CNT) electrodes grown on stainless steel (SS) plate and wire for electrochemical sensor applications. Multi-wall carbon nanotubes with different diameters were grown on the SS plate and wire by chemical vapor deposition from an ethylene precursor. The SS provides a good electrical and mechanical connection to the CNT, and the SS is a tough substrate. The SS part of the electrode was electrically insulated from the analyte so that only the CNT were active in sensing. Cyclic voltammetry for the reduction of 6 mM K3Fe(CN)6 in a 1.0 M KNO3 supporting electrolyte was performed to examine the redox behavior of the CNT-SS electrode. The cyclic voltammograms showed sigmoidal-like shapes, indicating that mass transport around the electrodes is dominated by radial diffusion. Based on the cyclic voltammograms, the effective area of the CNT-SS electrodes and the number of individual CNTs were estimated. These results indicate that the CNT-SS plate and wire electrodes are good candidates to develop practical in vivo biosensors.     

Strategies for patterning biomolecules with dip-pen nanolithography

Dip-pen nanolithography (DPN) is an atomic force microscopy (AFM)-based lithography technique, which has the ability to fabricate patterns with a feature size down to approximately 15 nm using both top-down and bottom-up approaches. DPN utilizes the water meniscus formed between an AFM tip and a substrate to transfer ink molecules onto surfaces. A major application of this technique is the fabrication of micro- and nano-arrays of patterned biomolecules. To achieve this goal, a variety of chemical approaches has been used. This review concisely describes the development of DPN in the past decade and presents the related chemical strategies that have been reported to fabricate biomolecular patterns with DPN at micrometer and nanometer scale, classified into direct- and indirect DPN methodologies, discussing tip-functionalization strategies as well.     

Experimental Verification of Photovoltaic-based Three-phase Four-wire Series Hybrid Active Power Filter

Abstract—This article proposes a photovoltaic and battery interfaced series hybrid active power filter, which is comprised of a series active power filter and an inductor-capacitor (LC) shunt passive filter. The main benefits of the proposed system provide the compensation against the voltage harmonics, current harmonics, and voltage interruption for the whole day. A series active power filter demands a source of energy for compensating the voltage sag/swell. The proposed topology utilizes the green energy source with an energy storage unit to meet the DC-link voltage requirement of the series active power filter. The control strategy is based on the dual formulation of the compensation system principles with adaptive fuzzy logic controller. The simulation and experimental studies are carried out to validate the effectiveness of the proposed photovoltaic interfaced three-phase four-wire series hybrid active power filter.