Risk-based rules for crane safety systems

The International Maritime Organisation (IMO) has recommended a method called formal safety assessment (FSA) for future development of rules and regulations. The FSA method has been applied in a pilot research project for development of risk-based rules and functional requirements for systems and components for offshore crane systems. This paper reports some developments in the project. A method for estimating target reliability for the risk-control options (safety functions) by means of the cost/benefit decision criterion has been developed in the project and is presented in this paper. Finally, a structure for risk-based rules is proposed and presented.     

Formal safety assessment based on relative risks model in ship navigation

Formal safety assessment (FSA) is a structured and systematic methodology aiming at enhancing maritime safety. It has been gradually and broadly used in the shipping industry nowadays around the world. On the basis of analysis and conclusion of FSA approach, this paper discusses quantitative risk assessment and generic risk model in FSA, especially frequency and severity criteria in ship navigation. Then it puts forward a new model based on relative risk assessment (MRRA). The model presents a risk-assessment approach based on fuzzy functions and takes five factors into account, including detailed information about accident characteristics. It has already been used for the assessment of pilotage safety in Shanghai harbor, China. Consequently, it can be proved that MRRA is a useful method to solve the problems in the risk assessment of ship navigation safety in practice.     

透明导电IMO薄膜的载流子迁移率研究

采用van der Pauw法、等离子振荡波长法和光谱拟合法等三种方法对IMO(In2 O3 ∶Mo)薄膜和ITO(In2 O3 ∶Sn)薄膜的载流子迁移率进行了测量和比较。结果表明 ,IMO薄膜的载流子迁移率高达 10 0cm2 V-1s-1以上 ,远超过已报导的其他掺杂透明导电氧化物 (TCO)薄膜的载流子迁移率 ;IMO薄膜的载流子有效质量约为电子静止质量的 0 35倍 ;IMO薄膜的高载流子迁移率主要是由于载流子受到的散射作用较弱所引起。这无法用通常的掺杂TCO薄膜的载流子散射理论来解释 ,为此引入复合效应进行分析。在ITO薄膜中 ,每形成一个电中性复合粒子 ,就会使两个掺杂的Sn4 失去贡献载流子的电活性 ;而在IMO薄膜中 ,即使一个掺杂Mo6 与晶格间隙中的一个O2 -结合成复合离子后 ,该复合离子仍然会贡献出一个载流子 ,故薄膜中形成的电中性复合粒子数目较少 ,从而导致价态差为 3的IMO薄膜中的电中性复合粒子对载流子的散射远低于价态差为 1的ITO薄膜 ,因此 ,IMO薄膜有可能获得较高的载流子迁移率     

Fast algorithm for the reliability evaluation of large-scale electrical distribution networks using the section technique

An efficient practical reliability evaluation algorithm is presented for large-scale radial electrical distribution networks (EDN) using a section technique and taking into account the construction features of the EDN. The definition and properties of the section of a branch (SOB) concept, the component spreading method (CSM) for forming the SOB, and an algorithm for the reliability evaluation of an EDN based on the SOB are presented in this paper. The functional unit of an EDN in the failure simulation process is an SOB rather than a component as used in the conventional method and the CSM is used to identify the area controlled by switches. The proposed algorithm should prove useful in practical engineering applications as the repeated search for the areas controlled by switches can be avoided, which sharply reduces the demand for fault enumeration simulation. The developed algorithm was tested on a small test system and a number of practical EDN and the results show the effectiveness and applicability of the proposed approach.     

Advanced light trapping materials: Double layer ZnO:B based transparent conductive oxide

We present double layer structures consisting of ZnO:B/ZnO:B (BZO) and In₂O₃:Mo (IMO)/BZO films. The structure offers the unique opportunity of separating the conductivity of transparent conductive oxides from their light scattering behavior and allows their optimization for use in thin film solar cells. The layers serve as carrier transport and light trapping layers, respectively. BZO films were prepared by mid-frequency magnetic sputtering from a ZnO:B₂O₃ ceramic target. In order to enhance the conductivity of the BZO films, hydrogen was introduced into the sputtering atmosphere. Introducing hydrogen increased the mobility of the BZO-based double layer films to near 30 cm²/V•s. Efficient scattering was achieved by etching the film in dilute hydrochloric acid. IMO films were also tested as the transport layer. An unconventional surface morphology was obtained by etching the IMO/BZO double layer film. Using this cascading multilayer structure IMO/BZO film as the front contact in a-Si:H solar cell, 20.4% and 7.4% enhancements in short circuit current density were obtained compared to smooth IMO films and textured single layer BZO films.     

Multidentate Molecule Anchoring Halide Perovskite Surface and Regulating Crystallization Kinetics toward Efficient Light-Emitting Diodes

Functional passivators are conventionally utilized in modifying the crystallization properties of perovskites to minimize the non-radiative recombination losses in perovskite light-emitting diodes (PeLEDs). However, the weak anchor ability of some commonly adopted molecules has limited passivation ability to perovskites and even may desorb from the passivated defects in a short period of time, which bring about plenty of challenges for further development of high-performance PeLEDs. Here, a multidentate molecule, formamidine sulfinic acid (FSA), is introduced as a novel passivator to perovskites. FSA has multifunctional groups ( S≐O,  C≐N and  NH₂) where the  S≐O and  C≐N groups enable coordination with the lead ions and the  NH₂ interacts with the bromide ions, thus providing the most effective chemical passivation for defects and in turn the formation of highly stable perovskite emitters. Moreover, the interaction between the FSA and octahedral [PbBr₆]⁴⁻ can inhibit the formation of unfavorable low-n domains to further minimize the inefficient energy transfer inside the perovskite emitters. Therefore, the FSA passivated green-emitting PeLED exhibits a high external quantum efficiency (EQE) of 26.5% with fourfold enhancement in operating lifetime as compared to the control device, consolidating that the multidentate molecule is a promising strategy to effectively and sustainably passivate the perovskites.     

基于Pro/E平台的参数化板料冲压成形模拟系统的研究

基于Pro/E二次开发工具Pro/Toolkit开发了板料冲压成形模拟系统FSA（Forming Simulation Application）,在建模参数和设计对象的控制尺寸之间建立了唯一、实时的对应关系,实现了参数化建模。介绍了FSA系统的设计思想和特点,并重点论述了基于＂顶层基本骨架＂的装配体模型树设计和通过Pu...     

Effects of oxygen gas flow rate and ion beam plasma conditions on the opto-electronic properties of indium molybdenum oxide films fabricated by ion beam-assisted evaporation

The purpose of the present work is to experimentally study the effects of the oxygen gas flow rate and ion beam plasma conditions on the properties of indium molybdenum oxide (IMO) films deposited onto the polyethersulfone (PES) substrate. Crystal structure, surface morphology, and optoelectronic properties of IMO films are examined as a function of oxygen gas flow rate and ion beam discharge voltage.Experimental results show that the IMO films consist of a cubic bixbyite B-In₂O₃ single phase with its crystal preferred orientation alone B(222). Mo⁶⁺ ions are therefore considered to partially substitute In³⁺ sites in the deposit. Under-controlled ion bombardment during deposition enhances the reaction among those arriving oxygen and metal ion species to condense into IMO film and facilitates a decreased surface roughness of IMO film. The film with ultimate crystallinity and the lowest surface roughness is obtained when the oxygen flow rate of 3 sccm and the discharge voltage of 110 V are employed. This results in the lowest electrical resistivity due mainly to the increased Hall mobility and irrelevant to carrier concentration. The lowest electrical resistivity of 8.63 × 10^− 4 ohm-cm with a 84.63% transmittance at a wavelength of 550 nm can be obtained, which satisfies the requirement of a flexible transparent conductive polymer substrate.     

Improved merit order and augmented Lagrange Hopfield network for unit commitment

This paper proposes an improved merit order (IMO) and augmented Lagrange Hopfield network (ALHN) for unit commitment (UC). IMO is a merit-order method which is based on average production cost of generating units improved by heuristic search algorithms, whereas ALHN is a continuous Hopfield neural network with its energy function based on augmented Lagrange relaxation. The proposed IMO-ALHN solves UC problem in three stages. In the first stage, IMO is applied for unit scheduling. In the second stage, ALHN is used to solve ramp rate constrained economic dispatch (RED) based on the obtained unit schedule, and a strategy for repairing ramp rate constraint violation is performed if a feasible solution is not found. In the last stage, a heuristic search for unit decommitment is applied on the obtained solution from RED for further improvement and ALHN is again applied to solve RED if there is any change in the unit schedule. The proposed method is tested on systems up to 1000 generating units with schedule time horizon up to 168 h. Test results indicate that the proposed method is very attractive and favourable over many other methods due to substantial production cost savings and faster computational times.     

Design of alternate solvent for recovery of residual palm oil: simultaneous optimization of process performance with environmental,health and safety aspects

In this work, a computer-aided molecular design (CAMD)-based approach has been developed to design alternative solvents for extracting palm oil from palm pressed fibre (PPF). PPF is a by-product from palm oil milling process produced during the extraction of crude palm oil from fresh fruit bunches. It is noted that the oil that found in PPF consists of high concentration of carotenoids; therefore, palm oil industries are trying to recover the residual oil in PPF. Hexane is conventionally used as a solvent to extract PPF. However, hexane has high boiling point which leads to significant degradation of carotene during solvent recovery. Besides, hexane is considered as a toxic chemical; thus, the extracted oil cannot be used in food applications. In order to overcome the limitations of hexane, this work presents a systematic approach to generate alternative solvents with desirable attributes for PPF oil extraction via CAMD with the integration of safety and health aspects. In this work, diffusivity is defined as a key parameter to evaluate the solvent functionality because the solvent must diffuse through the fibrous matrix to solubilize trapped oil. The safety and health aspects were assessed by implementing disjunctive programming to discretize the properties for allocation of subindex scores. The developed algorithm can trade-off the process and environmental, health and safety (EHS) performances and identify alternative solvents which improve EHS performance compare with hexane.     

氧分压对掺钼氧化铟透明导电薄膜光电性能的影响

采用射频磁控反应溅射法在k9玻璃衬底上制备了In2O3∶Mo(IMO)透明导电薄膜,分析了不同氧分压条件下IMO薄膜的晶体结构、化学成分及光电性能.结果表明:不同氧分压下制备的IMO薄膜具有不同晶粒的取向性;随着氧分压的增加,薄膜的载流子浓度、载流子迁移率先增加后减小;薄膜的电阻率呈现先增加再减少然后再增加的趋势.在可...     

High-performance transparent conducting oxide nanowires

We report the growth and characterization of single-crystalline Sn-doped In2O3 (ITO) and Mo-doped In2O3 (IMO) nanowires. Epitaxial growth of vertically aligned ITO nanowire arrays was achieved on ITO/yttria-stabilized zirconia (YSZ) substrates. Optical transmittance and electrical transport measurements show that these nanowires are high-performance transparent metallic conductors with transmittance of approximately 85% in the visible range, resistivities as low as 6.29 x 10(-5) Omega x cm and failure-current densities as high as 3.1 x 10(7) A/cm2. Such nanowires will be suitable in a wide range of applications including organic light-emitting devices, solar cells, and field emitters. In addition, we demonstrate the growth of branched nanowire structures in which semiconducting In2O3 nanowire arrays with variable densities were grown epitaxially on metallic ITO nanowire backbones.     

Monte Carlo estimation of the differential importance measure: application to the protection system of a nuclear reactor

In this paper, we perform a reliability/availability analysis by means of the Monte Carlo simulation method and illustrate a perturbation method, inherited from the particle transport field, which allows to compute first-order, differential sensitivity indexes with little additional computational effort. The proposed method is illustrated first on a simple case study and, successively, on a nuclear safety system, the reactor protection system. In these applications, the sensitivity indexes are used to compute the differential importance measure, recently introduced to respond to the need of the analyst/decision maker to get information about the importance of changes in the stochastic properties of system components.     

Accident investigation reporting deficiencies related to organizational factors in machinery space fires and explosions

Careful accident investigation provides opportunities to review safety arrangements in socio-technical systems. There is consensus that human intervention is involved in the majority of accidents. Ever cautious of the consequences attributed to such a claim vis-à-vis the apportionment of blame, several authors have highlighted the importance of investigating organizational factors in this respect. Specific regulations to limit what were perceived as unsuitable organizational influences in shipping operations were adopted by the International Maritime Organization (IMO). Guidance is provided for the investigation of human and organizational factors involved in maritime accidents. This paper presents a review of 41 accident investigation reports related to machinery space fires and explosions. The objective was to find out if organizational factors are identified during maritime accident investigations. An adapted version of the Human Factor Analysis and Classification System (HFACS) with minor modifications related to machinery space features was used for this review. The results of the review show that organizational factors were not identified by maritime accident investigators to the extent expected had the IMO guidelines been observed. Instead, contributing factors at the lower end of organizational echelons are over-represented.     

Barrier and operational risk analysis of hydrocarbon releases (BORA-Release). Part I. Method description

Investigations of major accidents show that technical, human, operational, as well as organisational factors influence the accident sequences. In spite of these facts, quantitative risk analyses of offshore oil and gas production platforms have focused on technical safety systems. This paper presents a method (called BORA-Release) for qualitative and quantitative risk analysis of the platform specific hydrocarbon release frequency. By using BORA-Release it is possible to analyse the effect of safety barriers introduced to prevent hydrocarbon releases, and how platform specific conditions of technical, human, operational, and organisational risk influencing factors influence the barrier performance. BORA-Release comprises the following main steps: (1) development of a basic risk model including release scenarios, (2) modelling the performance of safety barriers, (3) assignment of industry average probabilities/frequencies and risk quantification based on these probabilities/frequencies, (4) development of risk influence diagrams, (5) scoring of risk influencing factors, (6) weighting of risk influencing factors, (7) adjustment of industry average probabilities/frequencies, and (8) recalculation of the risk in order to determine the platform specific risk related to hydrocarbon release. The various steps in BORA-Release are presented and discussed. Part II of the paper presents results from a case study where BORA-Release is applied.     

Enzymatically amplified time-resolved fluorescence immunoassay with terbium chelates.

We report an ultrasensitive, enzymatically amplified, time-resolved fluorescence immunoassay with a terbium chelate as the detectable moiety. In this immunoassay, the primary label is the enzyme alkaline phosphatase (ALP). ALP cleaves phosphate out of a fluorogenic substrate, 5-fluorosalicyl phosphate, to produce 5-fluorosalicylic acid (FSA). 5-Fluorosalicylic acid can then form a highly fluorescent ternary complex of the form FSA-Tb(3+)-EDTA, which can be quantified by measuring the Tb3+ fluorescence in a time-resolved mode. In this assay, exceptional sensitivity is achieved because of the enzymatic amplification introduced by ALP and the quantification by laser-induced microsecond time-resolved fluorometry. Time-resolved fluorometry is applicable because of the long fluorescence lifetime of the Tb3+ complexes. It is shown that in a model AFP assay 10(6) or 1.5 x 10(5) molecules can be detected (final assay volume, 100 microL) by using monoclonal or polyclonal detection antibodies, respectively. The assay demonstrates excellent precision (approximately 4%), and it seems to be highly suited for automated, sensitive, and rapid immunoassays.     

Effects of oxygen flow rate on microstructure and properties of indium molybdenum oxide films by ion beam-assisted deposition

The purpose of the present work is to experimentally study the effect of oxygen flow rate on the microstructure and properties of indium molybdenum oxide (IMO) films deposited onto the polyethersulfone (PES) substrate by ion beam-assisted deposition (IBAD). Crystalline quality, surface morphology, and optoelectronic properties of the IMO films are examined. Experimental results show that the IMO films present a columnar feature as observed by using FE-SEM with the corresponding root mean square (RMS) roughness of 2 nm as measured by using AFM. An increased oxygen flow rate reduces resistivity of the IMO film. The lowest resistivity of 1.59×10⁻³ Ω cm, with carrier mobility of 16.31 cm²/V s, carrier concentration of 1.02×10²⁰ cm⁻³, and visible transmittance of 82% of the IMO film was achieved under an oxygen flow rate of 5 sccm at an ion beam discharge voltage of 150 V.     

A Bayesian Belief Network modelling of organisational factors in risk analysis: A case study in maritime transportation

The paper presents an innovative approach to integrate Human and Organisational Factors (HOF) into risk analysis. The approach has been developed and applied to a case study in the maritime industry, but it can also be utilised in other sectors. A Bayesian Belief Network (BBN) has been developed to model the Maritime Transport System (MTS), by taking into account its different actors (i.e., ship-owner, shipyard, port and regulator) and their mutual influences. The latter have been modelled by means of a set of dependent variables whose combinations express the relevant functions performed by each actor. The BBN model of the MTS has been used in a case study for the quantification of HOF in the risk analysis carried out at the preliminary design stage of High Speed Craft (HSC). The study has focused on a collision in open sea hazard carried out by means of an original method of integration of a Fault Tree Analysis (FTA) of technical elements with a BBN model of the influences of organisational functions and regulations, as suggested by the International Maritime Organisation's (IMO) Guidelines for Formal Safety Assessment (FSA). The approach has allowed the identification of probabilistic correlations between the basic events of a collision accident and the BBN model of the operational and organisational conditions. The linkage can be exploited in different ways, especially to support identification and evaluation of risk control options also at the organisational level. Conditional probabilities for the BBN have been estimated by means of experts’ judgments, collected from an international panel of different European countries. Finally, a sensitivity analysis has been carried out over the model to identify configurations of the MTS leading to a significant reduction of accident probability during the operation of the HSC.     

一种用于输油管道安全保护的高,低压泄压阀

为了防止长输原油管道因遇突然事故对机，泵，阀等设备及管道的损坏，以保障安全平稳地输油，在输油管道上装设安全保护装置是十分必要的。我们根据液压系统中的溢流阀原理，参照了输油管道上引进的高压阀，设计出一种新型的应用于长输原油管道上的安全保护装置－先导式电动高压阀及气－液阻尼式电动低压泄压阀。