Search

The social work Grand Challenge to Promote Smart Decarceration's aim is to address the high rates of incarceration in the United States.Yet very little is known about criminal justice practitioners in the U.S.In this exploratory study. Practitioners in correctional facilities (Findings include the need for people who are incarcerated to have access to treatment for substance use, behavioral/mental health, and trauma-related issues. In addition, they reported the need for service coordination with agencies based in their home communities. Furthermore, the participants reported that they need more training and support on these topics in order to provide effective services to their clients.Implications for practice, research, and policy are discussed, including strategies to address all levels of primary, secondary, and tertiary prevention.

Nickel-rich layered oxides are currently considered the most practical candidates for realizing high-energy-density lithium metal batteries (LMBs) because of their relatively high capacities. However, undesired nickel-rich cathode–electrolyte interactions hinder their applicability. Here, we report a satisfactory combination of an antioxidant fluorinated ether solvent and an ionic additive that can form a stable, robust interfacial structure on the nickel-rich cathode in ether-based electrolytes. The fluorinated ether 1,1,2,2-tetrafluoroethyl-1H,1H,5H-octafluoropentyl ether (TFOFE) introduced as a cosolvent into ether-based electrolytes stabilizes the electrolytes against oxidation at the LiNi0.8Mn0.1Co0.1O2 (NCM811) cathode while simultaneously preserving the electrochemical performance of the Li metal anode. Lithium difluoro­(bisoxalato)­phosphate (LiDFBP) forms a uniform cathode–electrolyte interphase that limits the generation of microcracks inside secondary particles and undesired dissolution of transition metal ions such as nickel, cobalt, and manganese from the cathode into the electrolyte. Using TFOFE and LiDFBP in ether-based electrolytes provides an excellent capacity retention of 94.5% in a Li|NCM811 cell after 100 cycles and enables the delivery of significantly increased capacity at high charge and discharge rates by manipulating the interfaces of both electrodes. This research provides insights into advancing electrolyte technologies to resolve the interfacial instability of nickel-rich cathodes in LMBs.

Lithium metal as a battery anode is one of the most promising energy storage materials owing to its high theoretical capacity and low working potential. However, uncontrollable Li growth during cycling raises safety issues in the battery due to dendrite formation and a poor coulombic reversibility. Here, a design involving carbon nanodots (CDs) as electrolyte additives is introduced, which could significantly improve the morphology of the Li plating and cycling stability of lithium-metal batteries (LMBs). These CDs are suitable electrolyte additives because they show good dispersibility against organic solvents, originating from their 2–5 nm small-sized particles. In addition, CDs include surface negative charges and various functional groups, which are easily controllable through modulating the amount and types of precursors used. The surface negative charges and the functional groups in the CDs draw Li cations by electrostatic force and provide a strong Li-ion affinity. This synergistic combination enables uniform Li-ion transportation to the current collector, resulting in metal reduction with a smooth surface during the plating/stripping process. Moreover, the control of the CD-assisted Li dendrite morphology was examined by ex situ transmission electron microscopy. In the LMB full-cell tests with limited 20 μm-thick Li metal, the CD-containing electrolytes exhibited a capacity retention value of 99.9% after 100 cycles. Here, the CD-assisted Li deposition minimized the risks originating from Li dendrite growth, thus stabilizing the cycling ability of the LMB.

Sodium (Na) metal anodes with stable electrochemical cycling have attracted widespread attention because of their highest specific capacity and lowest potential among anode materials for Na batteries. The main challenges associated with Na metal anodes are dendritic formation and the low density of deposited Na during electrochemical plating. Here, we demonstrate a fluoroethylene carbonate (FEC)-based electrolyte with 1 M sodium bis(fluorosulfonyl)imide (NaFSI) salt for the stable and dense deposition of the Na metal during electrochemical cycling. The novel electrolyte combination developed here circumvents the dendritic Na deposition that is one of the primary concerns for battery safety and constructs the uniform ionic interlayer achieving highly reversible Na plating/stripping reactions. The FEC–NaFSI constructs the mechanically strong and ion-permeable interlayer containing NaF and ionic compounds such as Na2CO3 and sodium alkylcarbonates.

Here, we report the first electrochemical assessment of organophosphonate-based compound as a safe electrode material for lithium-ion batteries, which highlights the reversible redox activity and inherent flame retarding property. Dinickel 1,4-benzenediphosphonate delivers a high reversible capacity of 585 mA h g

Results are presented of a benchmark and uncertainty assessment study organised by the MARSTRUCT Virtual Institute on global linear wave loads on damaged ship. The study has two aims: to acquire valuable information regarding damage modelling in seakeeping analysis of damaged ships and to contribute to a rational approach for definition of the model uncertainty of linear seakeeping tools. Eight institutes participated in the benchmark, with six codes, representative of important linear seakeeping theories in use nowadays. The benchmark ship is the DTMB 5415 hull, with well documented and accessible data to perform seakeeping analysis and experimental results for motion and global wave loads. The uncertainty analysis is performed using the Frequency Independent Model Error as the uncertainty measure. The analysis is performed for vertical motions, vertical and horizontal global wave load components, and for torsional moments. Uncertainty measures of individual motion and load predictions are presented and compared. In addition, a comparative analysis of linear seakeeping theories is performed and the accuracy of the simplified methods used for the prediction of seakeeping of a damaged ship is assessed. Finally, recommendations are provided for efforts to improve modelling uncertainties in transfer functions of wave loads on damaged ships. Keywords: Benchmark study ; Seakeeping model experiments ; Damaged ship ; Wave loads ; Uncertainty assessment

We present an ultraconcentrated electrolyte composed of 5 M sodium bis(fluorosulfonyl)imide in 1,2-dimethoxyethane for Na metal anodes coupled with high-voltage cathodes. Using this electrolyte, a very high Coulombic efficiency of 99.3% at the 120th cycle for Na plating/stripping is obtained in Na/stainless steel (SS) cells with highly reduced corrosivity toward Na metal and high oxidation durability (over 4.9 V versus Na/Na+) without corrosion of the aluminum cathode current collector. Importantly, the use of this ultraconcentrated electrolyte results in substantially improved rate capability in Na/SS cells and excellent cycling performance in Na/Na symmetric cells without the increase of polarization. Moreover, this ultraconcentrated electrolyte exhibits good compatibility with high-voltage Na4Fe3(PO4)2(P2O7) and Na0.7(Fe0.5Mn0.5)O2 cathodes charged to high voltages (>4.2 V versus Na/Na+), resulting in outstanding cycling stability (high reversible capacity of 109 mAh g–1 over 300 cycles for the Na/Na4F...

Employing linear carbonates such as dimethyl carbonate (DMC), ethyl methyl carbonate (EMC), and diethyl carbonate (DEC) as electrolyte solvents provides an opportunity to design appropriate electrolyte systems for high-performance sodium-ion batteries (SIBs). However, in practice, the use of linear carbonate-containing electrolytes is quite challenging because linear carbonates readily decompose at Na metal electrodes or sodiated anodes. One of the promising approaches is using an electrolyte additive to resolve the critical problems related to linear carbonates. Our investigation reveals that remarkable enhancement in electrochemical performance of Na 4 Fe 3 (PO 4 ) 2 (P 2 O 7 ) cathodes with linear carbonate-containing electrolytes is achieved by using a fluoroethylene carbonate (FEC) additive. Importantly, the initial Coulombic efficiency of the Na deposition/stripping on a stainless steel (SS) electrode is drastically improved from 16% to 90% by introducing the FEC additive into ethylene carbonate (EC)/propylene carbonate (PC)/DEC (5/3/2, v/v/v)/0.5 M NaClO 4 . The underlying mechanism of FEC at the electrode-electrolyte interface is clearly demonstrated by 13 C nuclear magnetic resonance (NMR). In addition, the Na 4 Fe 3 (PO 4 ) 2 (P 2 O 7 ) cathode in EC/PC/DEC (5/3/2, v/v/v)/0.5 M sodium perchlorate (NaClO 4 ) with FEC delivers a discharge capacity of 90.5 mAh g −1 at a current rate of C/2 and exhibits excellent capacity retention of 97.5% with high Coulombic efficiency of 99.6% after 300 cycles at 30 °C.

In conjunction with electrolyte additives used for tuning the interfacial structures of electrodes, functional materials that eliminate or deactivate reactive substances generated by the degradation of LiPF

The organophosphorus compounds tris(trimethylsilyl) phosphite (TMSP) and vinylene carbonate (VC) have been considered for use as functional additives to improve the electrochemical performance of Li 1.1 Mn 1.86 Mg 0.04 O 4 (LMO)/graphite full cells. Our investigation reveals that the combination of VC and TMSP as additives enhances the cycling properties and storage performance of full cells at 60 °C. The unique functions of the TMSP additive in the VC electrolyte are investigated via ex situ X-ray photoelectron spectroscopy (XPS) and 19 F nuclear magnetic resonance (NMR) measurements. The TMSP additive effectively eliminates trace water and hydrogen fluoride (HF) and produces a protective film on the LMO cathode that alleviates manganese dissolution at 60 °C.

Investigation of the deleterious effect of high purity water vapor on fatigue crack growth rate (da/dN) in 7075-T651 shows that growth rate declines with decreasing water vapor pressure (PH2O) over a wide range of stress intensity range (ΔK). Decreasing ΔK experiments exhibit a novel minimum in da/dN for intermediate PH2O and low ΔK. This minimum and testing protocol dependent environmental-fatigue behavior are explained by crack wake fracture morphology and R-dependent crack opening displacement effects on molecular flow to the crack tip. This environmentally-based mechanism leads to the onset and reversal of a non-conservative and false high threshold stress intensity range.

We demonstrate the important strategy to design suitable electrolyte systems that make the desirable interfacial structure to allow the reversible sodiation/desodiation of Sn4P3 anodes. Our investigation reveals that the remarkable improvement in the electrochemical performance of Sn4P3 anodes for NIBs is achieved by the combination of fluoroethylene carbonate (FEC) with tris(trimethylsilyl)phosphite (TMSP). We clearly present the unique functions of this binary additive combination to build up a protective surface film on the Sn4P3 anode against unwanted electrolyte decomposition and to prevent the formation of the Na15Sn4 phase, which is accompanied by a large volume expansion during the Na insertion (sodiation) process.

Lithium difluoro(oxalato)borate (LiFOB) is investigated as an additive for enhancing the electrochemical performance of high-voltage lithium cobalt oxide (LiCoO2, LCO)/lithium nickel manganese cobalt oxide (LiNi0.6Co0.2Mn0.2O2, NMC) cathodes and high-capacity silicon/graphite (Si-C) anodes. LCO-NMC/Si-C full cells with a LiFOB additive have been found to exhibit improved high temperature electrochemical performance. To confirm the effects of LiFOB on the cathode and the anode, the surface chemistry of the anodes and cathodes cycled in electrolytes with and without the LiFOB additive are examined using ex-situ X-ray photoelectron spectroscopy (XPS). The LiFOB additive produces a LiF-based solid electrolyte interphase (SEI) on the Si-C anode and a carboxylate-based SEI on the LCO-NMC cathode.

Binary solvent mixtures containing NaClO4 salt were investigated as electrolytes for sodium-ion batteries. The electrochemical performance of Na4Fe3(PO4)2(P2O7) cathodes was substantially improved when paired with an ethylene carbonate (EC)/propylene carbonate (PC)-based electrolyte. Our investigation revealed that EC/PC/1 M NaClO4 exhibits superior oxidation durability at the cathode and is highly stable toward a Na-metal electrode. Keywords: Sodium-ion batteries, Electrolyte, Mixed-polyanion cathode, Solid electrolyte interphase

We present a promising electrolyte candidate, Mg(TFSI)2 dissolved in glyme/diglyme, for future design of advanced magnesium (Mg) batteries. This electrolyte shows high anodic stability on an aluminum current collector and allows Mg stripping at the Mg electrode and Mg deposition on the stainless steel or the copper electrode. It is clearly shown that nondendritic and agglomerated Mg secondary particles composed of ca. 50 nm primary particles alleviating safety concern are formed in glyme/diglyme with 0.3 M Mg(TFSI)2 at a high rate of 1C. Moreover, a Mg(TFSI)2-based electrolyte presents the compatibility toward a Chevrel phase Mo6S8, a radical polymer charged up to a high voltage of 3.4 V versus Mg/Mg(2+) and a carbon-sulfur composite as cathodes.

Tris(pentafluorophenyl) borane (TPFPB) is evaluated as an additive for improving electrochemical performance of lithium peroxide (Li 2 O 2 )-based electrodes. It is found that TPFPB significantly reduced the charge potential of Li 2 O 2 -based electrodes during the first charge process and improved reversible capacity during cycling without adding air (or O 2 ) to the cell. To confirm the effect of TPFPB on electrolyte decomposition, the surface chemistry of Li 2 O 2 -based electrodes cycled in electrolytes with and without TPFPB was investigated.

Initiated within MARSTRUCT Virtual Institute in December 2016 Challenges: How to incorporate damage effects in seakeeping analysis ? Quantification and modelling of wave load uncertainties (ISSC-ITTC Special Task Committee) . Goals: To conduct the first uncertainty study on numerical prediction of loads on damaged ships ; Aquiring valuable information regarding damage modelling in seakeeping analysis of damaged ship ; Providing a rational basis for definition of the uncertainty model to be used in structural reliability studies of damaged ships.

A computational tool was applied based on a two dimensional linear method to predict the hydrodynamic loads for damaged ships. Experimental tests on a ship model have also been carried out to predict the hydrodynamic loads in various design conditions. The results of the theoretical method and experimental tests are compared to validate the theoretical method. The extreme wave induced loads have been calculated by short term prediction. For the loads in intact condition, the prediction with duration of 20 years at sea state 5 is used, while for loads in damaged conditions the prediction in 96 hours exposure time at sea 3 is used. The maximum values of the most probable extreme amplitudes of dynamic wave induced loads in damaged conditions are much less than those in intact condition because of the reduced time. An opening could change the distribution of not only stillwater bending moment but also wave-induced bending moment. It is observed that although some cross sections are not structurally damaged, the total loads acting on these cross sections after damage may be increased dramatically compared to the original design load in intact condition.

The manganese dissolution behavior of lithium hexafluorophosphate (LiPF6) dissolved in carbonate-based organic solvents is investigated by ex situ field emission scanning electron microscope (FE-SEM), Fourier transform infrared (FT-IR), X-ray diffraction (XRD), and inductively coupled plasma (ICP). It is found that the LiPF6 salt anions in the electrolytes are prone to oxidize upon contacting delithiated lithium manganese oxide with high oxidizing power and the electrons that evolved from the oxidation of anions are consumed in the reduction of tetravalent manganese ions to trivalent manganese ions at 60 °C. The generated trivalent manganese ions readily undergo a disproportion reaction and thereby release divalent manganese ions into the electrolytes, which leads to a capacity loss in the lithium manganese oxide cathode.

Extensive academic and industrial efforts have been dedicated to developing battery-based energy storage technologies with high energy density, low cost, long cycle life, high energy efficiency, and ease of deployment in daily life. In particular, for large-scale electrical energy storage, attention has shifted to sodium (Na) metal batteries owing to the highest specific capacity and the lowest redox potential of metallic Na and the natural abundance of Na resources. Nevertheless, the exceedingly high electrochemical and chemical reactivity of Na metal electrodes toward organic liquid electrolytes and severe Na dendrite formation limit their commercialization. Since most Na deposition occurs at the interface between the anode (or the current collector) and the electrolyte, the discovery of a stable electrolyte is essential for utilizing Na metal anodes in practical applications. In this study, we demonstrate that fluorination solvent containing electrolyte dramatically enhances the reversibility of Na plating and stripping reactions in Na/Cu cells, realizes dense Na deposition, and leads to improved cycling stability at high current densities. By examining the detailed mechanism of the novel electrolyte system, we have found that the interfacial layer contains NaF, which has a high shear modulus and enhances the mechanical integrity of the interlayer by the attractive interaction between the F- ions and Na+ ions of ionic compounds such as Na2CO3 and sodium alkylcarbonates (NaO2CO-R-), resulting in the formation of mechanically strong and ion-permeable interlayers that suppress uncontrolled Na metal plating. The discovery of this work represents a step forward in the electrolyte design of Na metal anodes.

The objective of this work is to identify microstructural variables that lead to the large scatter of the relative resistance of 316 grade stainless steels to hydrogen environment embrittlement. In slow displacement rate tensile testing, two almost identical (by nominal chemical composition) heats of SUS 316L austenitic stainless steel showed significantly different susceptibilities to HEE cracking. Upon straining, drawn bar showed a string-like duplex microstructure consisting of α′-martensite and γ-austenite, whereas rolled plate exhibited a highly regular layered α′-γ structure caused by measured gradients in local Ni content (9.5–13 wt%). Both martensite and austenite are intrinsically susceptible to HEE. However, due to Ni macro segregation and microstructural heterogeneity, fast H-diffusion in martensite layers supported a 10 times faster H-enhanced crack growth rate and thus reduced tensile reduction in area. Nickel segregation is thus a primary cause of the high degree of variability in H 2 cracking resistance for different product forms of 316 stainless steel.

The prediction of wave-induced motions and loads is of great importance for the design of marine structures. Linear potential flow hydrodynamic models are already used in different parts of the ship design development and appraisal process. However, the industry demands for design innovation and the possibilities offered by modern technology imply the need to also understand the modelling assumptions and associated influences of nonlinear hydrodynamic actions on ship response. At first instance, this paper presents the taxonomy of different Fluid Structure Interaction (FSI) methods that may be used for the assessment of ship motions and loads. Consequently, it documents in a practical way the effects of weakly nonlinear hydrodynamics on the symmetric wave-induced responses for a 10,000TEU Container ship. It is shown that the weakly nonlinear FSI models may be useful for the prediction of symmetric wave-induced loads and responses of such ship not only in way of amidships but also at the extremities of the hull. It is concluded that validation of hydrodynamic radiation and diffraction forces and their respective influence on ship response should be especially considered for those cases where the variations of the hull wetted surface in time may be noticeable.

In this paper, we propose a PON-based access network based on conventional TDM-PON architecture for the smooth, economical and effective transition to the future optical access network. We also propose a dynamic MAC protocol for wavelength channel and bandwidth allocation in the TDM-PON subscriber networks, which can provide enhanced network scalability and flexibility, and greater adaptability to the increasing number of subscribers in TDM-PON. In the proposed dynamic MAC protocol, several key functions are manifested, such as multiple wavelength channel utilization and dynamic allocation of multiple time-slots to a user depending on SLA between OLT and ONUs to meet QoS requirements. A dedicated control channel is used for delivering the request and status information between OLT and ONUs. We evaluate the performances of the proposed MAC protocol thru a statistical queuing analysis and numerical simulations. In addition, through simulations using various traffic models we verify the superior performance of the proposed approach by comparing it with conventional TDM-PONs.

In this article, we propose a new decentralized hardware-based DBA scheme in TDM-PON. Of particular significance in the proposed scheme is that the bandwidth of the uplink data transmission is dynamically allocated to each ONU without the intervention of the OLT. In this way, software-based DBA processing can be eliminated in the OLT and ONUs, resulting in the simple, fast, and cost-effective operation of the DBA in TDM-PON. The performance of the proposed scheme was evaluated by performing a statistical analysis and numerical analysis of the average packet end-to-end delay. We confirmed the superior performance of the proposed scheme by comparing the results obtained for this technique with those of other EPONs.

Modern precipitation-hardened ultra-high-strength AERMET 100 steel (Fe-Co-Ni-Cr-Mo-C) is susceptible to severe transgranular hydrogen environment–assisted cracking (HEAC) in neutral 3.5 pct NaCl solution. The threshold stress intensity for HEAC, K TH , is reduced to as low as 10 pct of K IC , and the stage II subcritical crack growth rate, da/dt II, is up to 0.5 μm/s. Low K TH and high da/dt II are produced at potentials substantially cathodic, as well as mildly anodic, to free corrosion. However, a range exists at slightly cathodic potentials (–0.625 to –0.700 VSCE), where the crack growth rate is greatly reduced, consistent with reduced crack-tip acidification and low cathodic overpotential for limited H uptake. Short crack size (250 to 1000 μm) does not promote unexpectedly severe HEAC. High-purity AERMET 100 is susceptible to HEAC because martensite boundary trapping and high crack-tip stresses strongly enhance H segregation to sites that form a transgranular crack path. The stage II da/dt is H diffusion rate limited for all potentials examined. A semiquantitative model predicts the applied potential dependence of da/dt II using reasonable input parameters, particularly crack-tip H uptake reverse calculated from measured K TH and a realistic critical distance. Modeling challenges remain.

This paper investigates a hybrid wavelength division multiplexing (WDM) multiple access protocol combining the advantages of preallocation and reservation-based schemes using a subcarrier multiplexing (SCM) technique for passive double star optical networks. We include a node-grouping scheme in the proposed protocol to increase channel utilization and to reduce sensitivity to queueing delay time and propagation delay time. All nodes in a network are connected through passive star sub-hub forming multiple groups, and the groups are then connected through a central passive star hub resulting in a passive double star network. Each group is pre-assigned a WDM channel as its home channel, and a specific SCM channel identifies each node. In the proposed protocol, the frame is divided into slots corresponding to the number of groups, not the number of nodes. The reduced number of slots results in reduction of queueing delay time. Furthermore, additional reduction in the propagation delay time of the control packets is achieved by limiting the propagation paths of the control packets to the roundtrip between source nodes and sub-hub in a double star network.

In this paper, we report on a multi-year collaboration among computer scientists, toxicologists, chemists, and a statistician, in which the RL induction program was used to assist toxicologists in analyzing relationships among various features of chemical compounds and their carcinogenicity in rodents. Our investigation demonstrated the utility of knowledge-based rule induction in the problem of predicting rodent carcinogenicity and the place of rule induction in the overall process of discovery. Flexibility of the program in accepting different definitions of background knowledge and preferences was considered essential in this exploratory effort. This investigation has made significant contributions not only to predicting carcinogenicity and non-carcinogenicity in rodents, but to understanding how to extend a rule induction program into an exploratory data analysis tool.

Rodent carcinogenicities for a group of 30 chemicals which form the subject of the Second NIEHS Predictive-Toxicology Evaluation Experiment are predicted based on their subchronic organ toxicities. Predictions are made by rules learned by the rule learning (RL) induction program.

The Center for Aircraft Structural Life Extension (CAStLE) at the United States Air Force (USAF) Academy has undertaken work to produce a standardized test method for determining the effect of a corrosion inhibitor containing coating chromate on small scale fatigue damage. CAStLE is specifically focusing their research on the effect of chromate primers on the pit-to-crack transition and crack growth under the damage tolerant flaw size. Quantifying the chromate effect at the small damage scale is also necessary to provide a baseline to compare the efficacy of new and safer coatings on fatigue life. To correctly account for these factors, bare and chromate primered test specimens of AA7075-T651 were produced with a center hole and a corrosion pit at the edge of the hole, and subsequently fatigued using representative environments and loading schemes until a crack of 1 mm was produced. Another unknown with chromate coatings is whether enough chromate to reduce the fatigue crack growth rate can leach out of the primer in the time it takes to grow from a pit to a 1 mm fatigue crack. The current results suggest that more work needs to be completed on the K-solution for the sample and to quantify the ability of chromate to leach into a solution from a primer coating.

As part of WILS II (Wave Induced Loads on Ships) Joint Industry Project organised by MOERI (Maritime and Ocean Engineering Research Institute, Korea), Lloyd’s Register has undertaken time domain springing and whipping analyses for a 10,000 TEU class container ship using computational tools developed in the Co-operative Research Ships (CRS) JIP [1]. For idealising the ship and handling the flexible modes of the structure, a boundary element method and a finite element method are employed for coupling fluid and structure domain problems respectively. The hydrodynamic module takes into account nonlinear effects of Froude-Krylov and restoring forces. This Fluid Structure Interaction (FSI) model is also coupled with slamming loads to predict wave loads due to whipping effects. Vibration modes and natural frequencies of the ship hull girder are calculated by idealising the ship structure as a Timoshenko beam. The results from springing and whipping analyses are compared with the results from linear and nonlinear time domain calculations for the rigid body. The results from the computational analyses in regular waves have been correlated with those from model tests undertaken by MOERI. Further the global effects of springing and whipping acting on large container ships are summarised and discussed.Copyright © 2011 by ASME

Chirp cancellation method is proposed to reduce XPM effects in DWDM optical channels, which is executed by controlling the time delay and power of transmitted pulses. Simulation results verify the effectiveness of the proposed method.

In this paper, we propose the power detection (PD)-based TDM-PON architecture, which is implemented for a hardware-based decentralized DBA (dynamic bandwidth allocation) among ONUs, without OLT's intervention to service. The proposed approach is characterized by a simple, fast and cost-effective operation on TDM-PON.

This paper presents analysis procedures of a prototype semi-submersible which consists of rectangular pontoons and square columns. The proposed semi-submersible is based on standard cubic boxes constructed by stiffened flat panel line assembly techniques. The prediction of global loads and responses is of great importance to engineers for assessing the safety of marine structures. In this paper analysis methods to determine the global structural loads and to assess the viability of the multi-purpose semi-submersible are described. Static loads in the still water condition and wave induced dynamic loads of cylindrical members in different design conditions were determined to investigate the viability of the proposed semi-submersible. Further the assessment of the safety against failure due to excessive maximum loads was accomplished in ultimate limit states. INTRODUCTION Currently the need of offshore oil and gas industry fields in deep waters has increased. International Maritime Associates Inc had recently completed an in-depth assessment of the floating production sector. The study described more than 80 offshore projects in the planning stage which potentially require floating production answers. At the moment there are 156 floating production platforms in operation or available. This had shown an almost 250% increase in the number of units over the last 10 years. Further another 37 production floaters are on order including 26 FPSOs, two TLPs, four production semi-submersibles and five production spars as well as five floating storage units [1,2]. Offshore production solutions in deep water can economically be accomplished only by compliant systems rather than by fixed type platforms whose capital costs escalate rapidly with increasing water depth [3,4]. Boonstra and Goldan had reported the application of modular structural elements in the design and production of semi-submersible systems [4,5]. In addition Seaways Engineering Ltd developed a modular concept which aims at accomplishing maximum constructional simplicity so that production costs can be dramatically cut down. It is an un-powered multi-purpose semi-submersible which could be the basis, for instance, of a production platform to extract oil economically in marginal fields [6,7]. Principal particulars of the MPSS platform proposed by Seaways Engineering Ltd are shown in Table 1 and 2 [7]. In order to satisfy the objectives of the concept, the following steps were taken in the design [7,8,9,10]. see Fig.1 and 2.: • Stiffened flat panel line assembly techniques, as conducted in modern shipbuilding, were selected to cost down to the target level of £1000 per tonne. • Basic steel cube boxes (7.5