Search

The optimum combination of antioxidants used for stabilization of flaxseed oil and extension of its shelf life was examined. To achieve this goal, based on different antioxidant mechanisms, a combination of four types of antioxidants including tocopherol, ascorbyl palmitate (AP), phytic acid (PA), and a source of polyphenol (antioxidant of bamboo leaves (AOB), rosemary extract (RE), tea polyphenols extract (TP), and tea polyphenol palmitate (TPP)) were added to flaxseed oil. The effects were monitored using peroxide value (POV), thiobarbituric acid‐reactive substances (TBARS), free radicals, and Rancimat induction time (RIT) of flaxseed oil during accelerated storage. Flaxseed oil containing 80 mg/kg tocopherol, 40 mg/kg AP, 40 mg/kg PA, and 240 mg/kg TPP was found to be more stable to oxidation than other samples and had 3.22‐fold longer shelf life than that of the control flaxseed oil. PRACTICAL APPLICATIONS: Due to its high concentration of alpha‐linolenic acid, flaxseed oil is prone to oxidation. To improve the oxidative stability of flaxseed oil and prolonging its shelf life, the optimum formulation and ratio of mixtures of antioxidants with different antioxidant mechanisms were studied. Our results indicated that the flaxseed oil containing 80 mg/kg tocopherol, 40 mg/kg AP, 40 mg/kg PA, and 240 mg/kg TPP was very stable to oxidation. And the shelf life of the flaxseed oil containing this optimum mixture of antioxidants was 3.22‐fold longer than that of the control flaxseed oil. Therefore, adding the optimum mixture of antioxidants will help to produce the flaxseed oil products with better oxidative stability for commercial development.

A gallic acid (GA) alkyl ester exerting the best antioxidant effect in flaxseed oil was identified from ten GA alkyl esters with various chain lengths, which was used in combination with other antioxidants including antioxidant of bamboo leaves, ascorbyl palmitate, butylated hydroxytoluene, phytic acid, phospholipid, rosemary extract, tocopherol, tea polyphenols, and tea polyphenol palmitate (TPP) to improve oxidative stability of flaxseed oil. Rancimat induction period, peroxide value, thiobarbituric acid-reactive substances, and electron paramagnetic resonance assays indicate that myristyl gallate (GA-C14) was the best GA ester. The flaxseed oil containing GA-C14 and TPP demonstrated the best oxidative stability among all the composite antioxidants. Through optimizing the mixture ratio, the flaxseed oil containing 34.4 mg/kg GA-C14 and 480 mg/kg TPP showed the best oxidative stability. Its shelf life was predicted by an accelerated shelf life testing using the Arrhenius model, which was prolonged 4.83-fold compared to the control sample under 25 °C.

Partial discharge inside a high-voltage switchgear can cause serious accidents. Partial discharge detection can reduce the incidence of accidents. This article summarizes the current research status of common high-voltage switchgear partial discharge detection technologies (Transient Earth Voltage or TEV, Utrasonic or AE and Ultra-High Frequency or UHF), introduces the research status of partial discharge model identification and localization of PD source, and finally looks forward to future research directions.

At present, the selection of construction methods in the tunnels with super large sections often relies on the experience for lack of a definite and feasible method. Based on the design method of formation-structure tunnels, the paper adopts FEM strength reduction to conduct numerical researches on the optimization of construction methods in tunnels with super large section. Taking a tunnel with super large section in a subway station as example, the paper first carries out numerical simulation on arch-wall method and double sidewall pilot tunnel method. Then it compares and analyzes the calculation results of surrounding rock displacement, stress on anchors and surrounding rock stability during construction. Finally, the paper suggests double sidewall pilot tunnel method. The analysis on the calculation examples shows that numerical method can quantitatively and directly display the difference between various construction methods and realize the optimization of construction methods in tunnels with super large section.

Geogrids is widely used because of its effective interlocking with the surrounding soil, the improvement to the mechanic properties of soil and the low costs. At present, indoors experiments of interface features are conducted to study the reinforcement mechanism of geogrids, including the tests of direct shear and pullout. Due to the limitation of facility sizes and other experimental conditions, most current experiments do not completely consider the actual mechanic situation of geogrids in practical engineering. So new methods should be worked out. Based on numerical methods, the paper respectively studies the features of direct shear friction and pullout friction of geogrids to analyze the influences of vertical distances between geogrids and the thickness of salient points on the interface features. The research shows that the strength indexes of interface are relatively larger and the functions of reinforcement are stronger when the vertical distances between geogrids are smaller and the thickness of salient points are larger. The results of the study indicate that to identify the reasonable strength indexes of geogrids interface based on numerical methods is feasible.

Load test is the main method to identify the bearing capacity of foundation in practical engineering. However, some problems are existing in the experiment, such as the scale effect, high cost and long construction period. The newly numerical ultimate analysis can overcome the shortcomings of time-consuming, complicated operation, inaccuracy and so on, which is gradually becoming an effective calculation method in geo-technical engineering. The paper adopts increment loading method and ultimate strain method to simulated the load test numerically. The calculation examples in the paper show that the results of load test can be obtained through numerical ultimate analysis, where the ultimate strain method is better.

The effect of ion current density of argon plasma on target sputtering in magnetron sputtering process was investigated. Using home-made ion probe with computer-based data acquisition system, the ion current density as functions of discharge power, gas pressure and positions was measured. A double-hump shape was found in ion current density curve after the analysis of the effects of power and pressure. The data demonstrate that ion current density increases with the increase in gas pressure in spite of slightly at the double-hump site, sharply at wave-trough and side positions. Simultaneously, the ion current density increases upon increase in power. Especially, the ion current density steeply increases at the double-hump site. The highest energy of the secondary electrons arising from Larmor precession was found at the double-hump position, which results in high ion density. The target was etched seriously at the double-hump position due to the high ion density there. The data indicates that the increase in power can lead to a high sputtering speed rate.

In order to make the intelligent materials have a new development in the field of mechanical engineering, composition of intelligence materials is briefly introduced in this article; Design thought of intelligent materials are detailed analyzed; Main functions of the intelligent materials appropriate; it can quickly to recovery to original state after external stimulus elimination [3]. The measure indicator should also take into account the unified between the strong function and low complexity from the use, therefore, a quantitative indicator is proposed, it called intelligence effect represented by MI, it mean the number of functions divided by the system components number of the n-th . was described; Typical application of the intelligent materials are stated, optical fiber and shape memory alloy are used as a example. At last the research difficulties of energy conversion and storage of intelligent materials are detailed discussed, and the future research direction of intelligent materials is pointed out. In the future, the development direction of intelligent materials mainly include these aspects, such as the study of bionics theory on conceptual design of intelligent materials, the study of intelligence material intrinsic properties and evaluation system of intelligence quotient, the study of dissipative II. INTELLIGENT MATERIAL DESIGN IDEAS Design ideals of intelligent materials are relative with the following factors: material development history, influence of artificial intelligence computer [4], intelligent materials manufacturing, software function material, the material aspirations, energy delivery, and materials with the timeline. Development and design ideas of intelligence materials should start from two different point of view, one is the bionic technology, another is structures characteristic of the intelligent material itself. structure theory applied in intelligent materials, the principles of complex integration and design theory of intelligence materials, the nonlinear theory of integrated intelligent structure, the humanoid intelligent control theory, etc. A. Bionic technology Keywords-sensitive materials; optical fiber; shape memory alloys; bionic technology; sensor Due to the organism has environmental perception and response, it provides a blueprint for intelligence material design [5]. Intelligence is a characteristic of organisms, and the environmental perception and response inspire people to explore the adaptive of the material systems and structures from the bio-science and bio-engineering and approximation to the multiple functions of the organism.

Surface modification of nanoparticles is a new technology, it refers to the use of physical, chemical and other methods to deal with surface of the nanoparticles. Research objective of this paper is surface modification methods and applications. All analysis is based on the need of use, change the structure and status of the surface of nanoparticles purposefully such as crystal structure of surface, functional groups, surface energy, surface wettability, electric property, surface adsorption and reaction characteristics and so on. The types and purposes of nanoparticle surface modification are introduced. The mechanism, characteristics and process of surface physical modification methods of nanoparticles such as surfactant and surface deposition are analyzed. The characteristics, mechanism and chemical reaction process of the nanoparticles surface chemical modification methods such as esterification reaction, coupling agent, phosphate eater, surface graft modification, in-situ modification are analyzed. Four examples of application are selected to verify the methods above. The verification results show the methods of nanoparticles surface modified are correct. Key words-Nanoparticles;Surface physical modification; Surface chemical modification; Dispersion ; Graft

The rotary is one of the important actions of deck hydraulic crane, and the hydraulic rotary apparatus is a driven source of rotary, so hydraulic rotary apparatus plays an important role on the rotary motion of the deck hydraulic crane for the stability and safety. When on the hydraulic rotary apparatus type selection, much more loads should be considered and the calculation for these loads is much more complicated. This paper makes a force analysis on the deck hydraulic crane when it is rotary then makes a selection on the key component of the rotary mechanism-hydraulic rotary apparatus for the deck hydraulic crane, and then has an explanation on the working principle of the hydraulic rotary apparatus which is selected. The selection plan has passed the examination of the China Classification Society, thus has an important reference value to the technicians and engineers who engage in deck hydraulic crane design. Keywords-crane; ship; hydraulic; rotary; motor

In this paper, two observer-based adaptive fuzzy output feedback control schemes are presented for a class of uncertain continuous-time multi-input-multi-output (MIMO) nonlinear dynamics systems whose states are not available. Within these schemes, fuzzy logic systems are employed to approximate the plant's unknown nonlinear functions and then the state observer is designed for estimating the states of the plant, upon which a fuzzy adaptive output feedback controller is firstly investigated. In order to overcome the controller singularity problem and relax the requirement of bounding parameter values, a second modified fuzzy adaptive output feedback controller is proposed by using a regularized inverse and a robustifying control term. All parameter adaptive laws and robustifying control terms are derived based on Lyapunov stability analysis, so that convergence to zero of tracking errors and boundedness of all signals in the closed-loop system can be guaranteed. Simulations performed on a two-link robot manipulator illustrate the approach and exhibit its performance.

A rapid control prototyping based on torque control algorithm using V-cycle mode for common rail diesel engine was developed, and a torque prediction model was present which including a feed-forward mean value engine model and a feedback correction of error caused by the feed forward model. Finally, experiments were carried out on test bench to verify the control feasibility and reliability of the strategies and optimize the emissions, Experimental results showed that the anticipated control effects were achieved and the engine reached the EURO-??? exhaust emission standard.

The PD controller requires measurements of both joint position and velocity. It is necessary to implement position and velocity sensors at each joint. The joint position measurement can be obtained by means of encoder, which gives very accurate measurement. The joint velocity is usually measured by velocity tachometer, which is expensive and often contaminated by noise. Two possible solution are to implement a velocity observers and numerical difference methods. This paper presents a comparison study of performances and characteristics of high-gain observers and LPP numerical difference methods.