LEED Implementation Guide for Construction Practitioners

Leadership in Energy and Environmental Design (LEED) is a certification program developed by the U.S. Green Building Council for designing, constructing, and certifying green buildings. This paper presents a LEED implementation guide for construction practitioners to assist them in the certification process. The guide was formulated primarily through input, suggestions, and recommendations received from LEED accredited professionals including architects, engineers, commissioning authorities, general contractors, construction managers, and facility managers. Data were collected through four questionnaire surveys where two of which were used for guide development and the other two for modification and validation. General contractors, construction managers, and engineers can use the LEED implementation guide as a reference for managing their LEED certification process. The proposed guide can also assist owners interested in building a LEED certified facility.     

A team-oriented design methodology for mixed model assembly systems

Team-oriented approaches are widely being used in modern real life assembly systems, as are other modern systems. In this paper, first the literature of single and mixed model assembly line balancing, which plays an important role for the design of assembly systems, is reviewed. The associated literature matrixes reveal that team-oriented approaches do not have an intensive research area. Second, a team-oriented mathematical programming model for creating assembly teams (physical stations) in mixed model assembly lines is devised. Owing to the fact that this model is NP hard, a scheduling based heuristic algorithm is developed. The mixed model assembly line design methodology, which includes a team-oriented algorithm as a step, is proposed. Both model sequencing and worker transfer systems are included in the methodology. The algorithms for each step of the methodology are also coded by using MATLAB and MS Excel is used as the user interface. Furthermore, the presented methodology was applied in a chosen segment of a real life mixed model tractor assembly system.     

Optimal space-frequency Group codes for MIMO-OFDM system

Space-frequency (SF) group codes are designed for multiple-input multiple-output orthogonal frequency-division multiplexing (MIMO-OFDM) systems. A rather general channel model is assumed, where the channel is frequency-selective Rayleigh fading with arbitrary power-delay profile. It is shown that the SF group code has a symmetric distance structure like the space-time group code, if the group consists of diagonal matrices. A scenario where the multiple codewords are loaded onto the subcarriers of the OFDM system in parallel is considered. The optimality condition on the choice of subcarrier allocation is found, and an optimal subcarrier-allocation scheme is proposed. A transmit scheme where rotated versions of the same signal are transmitted from different transmit antennas is proposed, and it is shown that it satisfies the optimality condition. Then matrix groups are designed which guarantee that the resulting SF codes are full rank. Numerical comparisons with recently published techniques in the literature verify our improved performance.     

Characterization and lime treatment of olive mill wastewater

Seventeen olive mill wastewater (OMW) samples were characterized. For characterization of the samples, amount of total, fixed, volatile, suspended, volatile-suspended solids, COD, oil-grease, polyphenol, volatile phenol, nitrogen and reducing sugar were determined. Effects of lime treatment on the waste samples were investigated. Reduction of contents of the samples treated with the lime was described. The effect of the addition of lime on an artificial phenolic mixture was also examined.     

Frequency-dependent conductivity in unannealed thin films of As0.40Se0.40Te0.20

Direct current (d.c.) and alternating current (a.c.) conductivity measurements have been performed on unannealed amorphous As_0.40Se_0.40Te_0.20 thin films. The d.c. measurements were performed at temperatures between 143 K and 343 K. The d.c. behaviour of the samples indicates different hopping conduction mechanisms between 143 K-210 K and 210 K-343 K. The a.c. measurements were performed at temperatures between 143 K and 300 K and at frequencies between 110 Hz and 1 MHz. The a.c. conductivity of the films is well represented by the form Cω^s where C and s are found to be temperature dependent parameters. The data are found to fit the correlated barrier hopping model, especially at low temperatures. The comparison of a.c. data with the unified theory of the extended pair approximation shows that the results fit to the quasi universal law predicted by this model, however, qualitative calculations give unreasonable values for the decay parameter α and the exponent l.     

Effect of austenitization heat treatment on the magnetic properties of Fe-40wt % Ni-2wt % Mn alloy

The effect of austenitization heat treatment on magnetic properties was examined by means of M6ssbauer spectroscopy on an Fe-40wt%Ni-2wt%Mn alloy. The morphology of the alloy was obtained by using scanning electron microscopy （SEM） under different heat treatment conditions. The magnetic behavior of the non heat-treated alloy is ferromagnetic. A mixed magnetic structure including both paramagnetic and ferromagnetic states was obtained at 800℃ after 6 and 12 h heat treatments. In addition, the magnetic structure of the heat-treated alloy at 1150~C for 12 h was ferromagnetic. With the volume fraction changing, the effective hyperfine field of the ferromagnetic austenite phase and isomery shift values were also determined by Mtssbauer spectroscopy.     

Consistency and Reliability of Construction Arbitration Decisions: Empirical Study

While construction arbitration is analyzed in a plethora of information, there is a paucity of hard data about the consistency and reliability of the construction arbitration decision. The assumption that an industry familiar adjudicator will provide a reliable and consistent decision in comparison with the expectation of the industry as a whole has not been tested. This paper presents the results of a study on the reliability and consistency of construction arbitration through the examination of a variety of arbitrators’ decisions on the same construction dispute scenario. Data was collected from attorneys, owners, owner representatives, contractors, and subcontractors. Compilation of the survey results finds little consistency in the arbitrator’s awards, but with much thoughtful care in award consideration. The results suggest that the arbitrator’s industry background does not influence the arbitrator’s award. There is also no significant award bias due to the arbitrator’s education level or years spent in construction business. The results also indicate that previous arbitration experience does not predict the award outcome. This paper concludes that construction arbitration is wholly unpredictable. However, the result will be a well-reasoned and unbiased decision.     

Effect of hydrogen addition using on-board alkaline electrolyser on SI engine emissions and combustion

In this study, an electrolyser was used to supply hydrogen to the SI engine. Firstly, the appropriate operation point for the electrolyser was determined by adjusting the amount of KOH in the electrolyte to 5%, 10%, 20% and 30% by mass, and applying 12 V, 16 V, 20 V, 24 V and 28 V voltages. Tests were first carried out with the gasoline without the use of an electrolyser, followed by operating the electrolyser at the appropriate point and sending obtained H₂ and O₂ to the engine in addition to the gasoline. The SI engine was operated between 2500 rpm and 3500 rpm engine speeds with and without hydrogen addition. Cylinder pressure, the amount of gasoline, H₂ and O₂ consumed by the engine and the emission data were collected from the test system at the aforementioned engine speeds. Furthermore, indicated engine torque, indicated specific energy consumption, specific emissions and HRR values were calculated. According to the results obtained, improvement in ISEC values was observed, and CO and THC values were improved by up to 21.3% and 86.1% respectively. Even though the dramatic increase in NO_x emissions cannot be averted, they can be controlled by equipment such as EGR three-way catalytic converter.     

A systematic comparative study of the efficient co-catalyst-free photocatalytic hydrogen evolution by transition metal oxide nanofibers

The efficiencies of a series of hydrogen evolving catalysts based on metal oxide nanofibers (NiO, Co₃O₄, Mn₃O₄) are investigated for the photocatalytic hydrogen evolution from water without using any co-catalyst under the visible light irradiation by using triethanolamine (TEOA) as an electron donor and Eosin-Y (EY) dye as a photosensitizer. It is found that the photocatalytic hydrogen evolution activities follow the order as: Mn₃O₄<Co₃O₄<NiO (196 μmolg^?1h^?1, 5552 μmolg^?1h^?1, 7757 μmolg^?1h^?1, respectively). Moreover, the catalytic behavior of these nanofibers on the hydrogen production has been also compared to bulk forms of NiO, Co₃O₄ and Mn₃O₄ by producing hydrogen 937 μmolg^?1h^?1, 901 μmolg^?1h^?1 and 135 μmolg^?1h^?1, respectively. The nanofiber structures demonstrated much higher photocatalytic activity than bulk forms due to the effect of the increased surface to volume ratio deduced from the fibrous character. The photocatalytic plausible pathway for the hydrogen production is also discussed.