Final contractor selection using the analytical hierarchy process

Some contractor selection methods currently in existence are criticized as incomplete and biased, and lacking consideration in terms of the contractor's ability to achieve simultaneously, time, cost, quality and safety standards. This research examines an alternative contractor selection model called the analytical hierarchy process (AHP), which will help construction clients to identify contractors with the best potential to deliver satisfactory outcomes in a final contractor selection process which is not based simply on the lowest bid. The AHP comprises three parts: hierarchic structure, prioritization procedure, and calculation of results. This model is tested by a hypothetical scenario where three contractor candidates are evaluated. The criteria used for contractor selection in the model have been identified, and the significance of each criterion has been arrived at by conducting a questionnaire survey in public organizations in Hong Kong. Comparisons are made by ranking the aggregate scores of each candidate with regard to their performance against each of the criteria, and the candidate associated with the highest scores is the best contractor on this occasion.     

The Devil Is in the Definitions

Problem: Traditional American zoning separates land uses, yet many urbanists and contemporary planners argue that bringing mixed use back to the American city is the key to restoring its vibrancy.

Purpose: This article compares the American and the German approaches to regulating land use.

Methods: I derive my conclusions from a review of German federal and local regulatory documents, and interviews I conducted in the German city of Stuttgart.

Results and conclusions: The U.S. zoning approach assumes that each land use district is suitable for only a single type of human activity, such as residential, commercial, or industrial use; whereas in Germany the prevailing principle is that each land use district is suitable for multiple types of activity, and most districts end up in mixed uses. Thus, despite some nominal similarities in the land use categories employed in both countries, the zoning methods are in fact starkly different.

Takeaway for practice: The German zoning system, which commonly mixes the land uses, challenges deeply engrained assumptions that underlie standard U.S. zoning, and it may offer useful alternatives for zoning reform.     

Partition of α-lactoalbumin and β-lactoglobulin from goat milk whey utilizing aqueous biphasic systems

This paper presents a study of α-lactoalbumin and β-lactoglobulin proteins partition from goat milk whey in-nature, utilizing aqueous biphasic systems comprised of polymers (polyethylene glycol, polypropylene glycol, polyvinylpyrrolidone), potassium phosphate, and water. The systems were evaluated at 25°C and pH 7.0. The influence of the polymer type, of the polymer molecular weight, and the polymer mass percentage on the partition coefficient of these proteins was assessed. Among the analyzed polymers, the polyethylene glycol (1500) was more indicated. The results showed that the separation technique by aqueous biphasic systems are applicable indicating high efficiency in the whey proteins separation process.     

Dynamic mechanical analysis of the multiple glass transitions of plasticized wheat gluten biopolymer

Glass transition of thermo‐molded biomaterials made from wheat gluten and its main protein classes is studied by dynamic mechanical analysis (DMA). The materials are plasticized with variable contents of glycerol (30–40 wt %) and water (0–20 wt %). For all materials, three successive relaxation phases are systematically detected. Their positions shift to lower temperature as the plasticizer content of materials increases. Composition in gluten, glycerol and water of each relaxation phase is estimated using the Couchman‐Karasz model. Irrespective of the plasticizer content or composition, the relaxation phases shows rather constant plasticizer volume fractions. The low‐, middle‐, and high relaxation phases include respectively around 30, 60 and 80 vol % of gluten protein. These relaxations are assigned to the segmental motion of the surface amino‐acid side groups, to the collective motion of packed gluten proteins, and to the gain in protein conformational mobility as a 2D network of interacting plasticizer molecules forms. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43254.     

Calculation of the Orientation Relationships of Directionally Solidified Eutectic Ceramics by a Modified Coincidence of Reciprocal Lattice Points Model (CRLP)

The Coincidence of Reciprocal Lattice Points (CRLP) method was used to predict, according to geometric considerations, the most favorable orientation relationships (ORs) between the component phases in a family of directionally solidified eutectic ceramics (DSEC) (NiO–YSZ, CoO–YSZ, NiO–CeO₂, NiO–GDC, CoO–CeO₂, and CoO–GDC) grown by the laser floating zone method. The ORs predicted by the CRLP model are consistent with those experimentally found in a previous work by means of Electron Backscatter Diffraction (EBSD). In this article, we also present a modification to the model with the aim of taking into account that the most stable ceramic–ceramic interfaces are usually formed between atomic planes with low Miller indices, due to their higher atomic density and bigger interplanar spacing. Thus, we introduce in the calculation of the overall coincidence volume a weighting factor which is a function of the interplanar spacing. This modified CRLP method has been applied to the aforementioned eutectic ceramics, and the results are presented and discussed in comparison with the traditional CRLP results and the experimental findings.     

Densification of 8Y‐Tetragonal‐Stabilized Zirconia Optoceramics with Improved Optical Properties by Y Segregation

8% Yttria‐stabilized zironcia (8YSZ) transparent ceramics have a wide technological applications. Segregation of the Y around the grain boundaries is favored by slow heating rate. The optimized sintering parameters helped in obtaining transparent ceramics of 8YSZ with a high percentage of cubic phase in addition to the presence of tetragonal phase. HRTEM was used to verify the grain growth suppression and to observe the presence of the cubic phase. The presence of cubic phase has suppressed the grain growth, which increased the transparency in the visible and infrared region without the addition of dopants or by utilizing high pressure.     

Air-Drying of Seeds: A Review

Beginning with harvesting, seeds are usually subjected to a series of processes which include drying for immediate or future use. Seed quality can be influenced by several factors during drying. This article presents a review of the seed air-drying process, including mathematical models based on differential equations derived from mass and energy balances for seeds and air in fixed and moving bed dryers. The article concludes with an overview of several potential drying technologies that can be applied to seeds.     

Identification of Human Adenovirus in Respiratory Samples with Luminex Respiratory Virus Panel Fast V2 Assay and Real-Time Polymerase Chain Reaction

In order to compare the last version of the Respiratory Virus Panel (RVP) Fast assay for human Adenovirus (hAdv) detection with a specific real-time polymerase chain reaction (qPCR), which is considered the gold standard for hAdv detection, nasopharyngeal samples collected from 309 children (age range, four months to eight years) with respiratory tract infection were tested using the RVP Fast v2 assay (Luminex Molecular Diagnostics, Inc., Toronto, ON, Canada) and a specific TaqMan qPCR to identify hAdv DNA. The RVP Fast v2 assay detected 30/61 (49.2%) hAdv infections that had been identified by real-time qPCR, demonstrating a significantly lower detection rate (p < 0.001). The sensitivity of the RVP Fast v2 assay in comparison to qPCR was lower in younger children (42.9% vs. 57.7%; Cohen’s kappa coefficient, 0.53); in samples with co-infections (40.0% vs. 56.7%; Cohen’s kappa coefficient, 0.52); and in samples with hAdv type C (45.9% vs. 57.1%; Cohen’s kappa coefficient, 0.60). Samples with lower viral loads were associated with a significantly lower sensitivity of the RVP Fast v2 assay (35.1% vs. 68.2%, p = 0.01; Cohen’s kappa coefficients, 0.49). The RVP Fast v2 assay has important limitations for the detection of hAdv and cannot be used to evaluate whether hAdvs are the main etiologic agent responsible for an outbreak or when epidemiological studies are performed.     

Effect of Laser Processing Parameters on the Formation of Intermetallic Compounds in Fe-Al Dissimilar Welding

Fusion welding of steel to aluminum is difficult due to formation of different types of Fe-Al intermetallics (IMs). In this work, 2 mm-thick steel was joined to 6 mm aluminum in overlap configuration using a 8 kW CW fiber laser. A defocused laser beam was used to control the energy input and allow melting of the aluminum alone and form the bond by wetting of the steel substrate. Experimentally, the process energy was varied by changing the power density (PD) and interaction time separately to understand the influence of each of these parameters on the IM formation. It was observed that the IM formation is a complex function of PD and interaction time. It was also found that the mechanical strength of such joint could not be simply correlated to the IM layer thickness but also depends on the area of wetting of the steel substrate by molten aluminum. In order to form a viable joint, PD needs to be over a threshold value where although IM growth will increase, the strength will be better due to increased wetting. Any increase in interaction time, with PD over the threshold, will have negative effect on the bond strength.     

Belgrade, Serbia

Few cities in Europe have a history as dramatic and tumultuous as that of the Serbian capital of Belgrade. The gracious “White City,” which rises spectacularly along the banks of the Danube and the Sava River, has been the site of wars, conquests and rapidly changing fortunes for much of its thousands-years long history. Belgrade suffered heavy destruction under both World Wars, and it has the unfortunate distinction of being the only European capital to be bombed at the end of the 20th century. Its modern history is marked by abrupt shifts in political status: from a capital of a relatively small nation-state, to a center of a larger and prosperous multi-national federation, to a capital of a nation-state once again. These shifts parallel the changing geopolitical position of Serbia/Yugoslavia in Europe. In this City Profile, I present the evolution of the built environment of Belgrade in five historic stages: ancient/medieval/Ottoman, early modern, communist, transitional, and contemporary. I show how each period left a distinct spatial imprint on Belgrade’s fabric. Finally, I discuss some contemporary challenges and opportunities in planning Belgrade’s future.