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This paper aims to investigate the fatigue life and dynamic loads of an arresting cable when a landing aircraft passes through a runway.

The cable is assumed to be under tension and with bending rigidity. The normal modes and natural frequencies of the vibrating wire are obtained analytically. The response of the arresting cable owing to the impact of the landing aircraft is modelled as a problem of initial conditions. The maximum normal and tangential stresses are determined for different landing conditions and landing aircraft sizes. The fatigue life of the wire is determined based on classical theories.

The results show that maximum shear stresses occur at the end of the cable. These shear stresses increased with higher off-centre landing position and decreased tyre width. Between 50 and 70% of the service life of the cable is reduced due to the dynamic loading effects.

A novel technique based on the solution of a continuous elastic system is proposed for analysing the displacements and stresses on an arresting cable due to the impact of a landing aircraft. The derived stresses can be used to calculate the service life of the cable.

This paper aims to present the studies which were carried out to determine building typology in Northern Pakistan, which is a seismically active region.

A total of 41 towns and cities were surveyed to collect the data of building types. Help was also taken from global positioning system and satellite imagery.

In total, 14 different types of buildings were identified in the region based on the structural system and combination of wall and roof materials; each of them was assigned an appropriate designation. The walls in these buildings were made of block, stone or brick, whereas the roof consisted of corrugated galvanised iron sheet, thatched roof, precast concrete planks or reinforced concrete (RC). Only 6 per cent buildings were found to be engineered RC buildings; this indicates a significance proportion of non-engineered building stock in Northern Pakistan.

The surveys were conducted in some of the selected areas. Other areas are beyond the scope of this work.

The presence of a huge deficient building stock in Pakistan indicates a major seismic risk. The seismic losses are largely dependent on the earthquake resistance of existing buildings and building stock. An inventory of existing buildings and their types can help in assessing seismic vulnerability of the built environment, which may lead to the development of policies for seismic risk reduction.

Presently, housing encyclopaedia does not exist in Pakistan. As a result, housing typology in the country is not known. The presented study addresses this gap in part. Housing typology surveys were conducted to study the typical construction practices in the selected areas and to determine the proportions of different building types in the overall building stock.

The purpose of this paper is to provide an estimate of the demand and supply in the housing market in Colombia in a period of high real estate valuation (2005-2016). On the demand side, it evaluates the impact of new housing prices, unemployment, stock market returns, real wages in the retail sector, remittances and mortgage rates. On the supply side, it estimates the influence of the price of new housing, construction costs, time deposit (TD) and mortgage rates. Real estate valuation was analyzed considering foreigners migration and land prices evolution.

Ordinary least squares (OLS) was used to estimate housing area with the semilog regression model and also to construct price models. OLS was also used in price models. Since quantities depend on prices and vice versa, a two-stage least squares (2SLS) was implemented.

Rising prices in new homes have an “elastic” effect on both demand and even higher effect on supply. Likewise, the real wage index for the retail sector has an elastic effect. On the other hand, the response to interest rates is negative, but statistically significant only on the supply side. Furthermore, the inflow of remittances is “inelastic” and statistically insignificant.

Housing can sometimes be a Giffen good, this result challenges the traditional neoclassical model, but it can be explained by investment reasons and “bubble” behavior in the housing market. One last influence is the difference between “temporary” and “permanent” migrations. The latter has a statistically significant and perfectly inelastic effect on the price of new homes.

To study the concept of honor in Turkish everyday life discourses. Many surveys have focused on namus, thus referring to honor killings, the mechanism of violence perpetrated against women. The reason given for such killings, often seen as barbaric and the result of criminal urges, is that some men feel compelled to restore what they see as family honor, soiled by the actions of their female relatives. However, these studies avoid another key aspect of honor: namely the plurality of its meanings as honor in Turkey may also be translated both as şeref and onur.

To begin to understand honor in all its forms, I conducted interviews with 100 Turkish men and women ages 20–27, all university students or graduates, from the Istanbul area. I also consulted the current official and Ottoman dictionaries to understand the history of word use.

Among the young adults interviewed “honor-virtue” (i.e., namus) is a debated topic. It may be analyzed at both theoretical and geographic levels and has the connotations of otherness and non-modernity. Namus co-exists with şeref (citizen honor) and onur (dignity).

Redefining the terms of honor could temper tensions between local/global, urban/countryside, modern/traditional, woman/man, and invisible frontier between namus and şeref worldviews. Advocating şeref and focusing on a broader definition of namus may encourage individuals to find their places in society. By focusing on national moral values, any individual in the country may participate in keeping the social order regardless of gender, age, or geographic location.

Lithium-polymer batteries have common usage in aviation industry especially unmanned aerial vehicles (UAV). Overheating is a serious problem in lithium-polymer batteries. Various cooling methods are performed to keep lithium-polymer batteries in the desired temperature range. The purpose of this paper is to examine pouch type lithium-polymer battery with plate fins by using particle image velocimetry (PIV) and computational fluid dynamics (CFD) for UAV.

Battery models were produced with a 3D printer. The upper surfaces of fabricated battery models were covered with plate fins with different fin heights and fin thicknesses. Velocities were obtained with PIV and CFD. Temperature dissipations were acquired with numerical simulations.

At the end of the study, the second battery model gave the lowest temperature values among the battery models. Temperature values of the seventh battery model were the highest temperatures. Fin cooling reduced the maximum cell temperatures noticeably. Numerical simulations agreed with PIV measurements well.

This paper takes into account two essential tools such as PIV and CFD, for fluid mechanics, which are significant in the aviation industry and engineering life.

The originality of this paper depends on investigation of both PIV and CFD for UAV and developing a cooling method that can be feasible for landing and take-off phases for UAV.

This paper aims to analyze experimentally and numerically the effect of the nozzle temperature and feed rates on the dimensions of the fused deposition modeling (FDM) polymer parts.

In total, 30 strips per sample were printed with the same width as the nozzle diameter. The strips were printed with one vertical movement of the nozzle head. The width of the strips was measured with a caliper at five locations. A linear regression model was created based on the experimental data to understand the correlation between the strip width deviation and the parameters of interest. Numerical simulations were performed to predict the swell of the polymer exiting the nozzle using finite element method combined with level set method. The experimental results were then used to validate the models.

The average accuracy of polylactic acid (PLA) samples was better than that of acrylonitrile butadiene styrene (ABS) samples. The average strip width had a tendency to increase with increasing temperature for PLA samples, whereas ABS samples showed mixed behavior. The strip width decreased with increasing feed rate for most cases. The measurement positions had a major effect on strip width when compared to nozzle temperature and feed rate. The numerical model predictions were in good agreement with the experimental data. A few discrepancies were observed at high feed rates and nozzle temperatures.

This study will contribute to gaps in knowledge regarding the effect of processing conditions on dimensional accuracy of FDM-printed parts. The developed numerical model can be efficiently used to predict the dimensional accuracy of FDM-printed parts.

The purpose of this paper is to evaluate the effect of post process combinations, e.g. hot isostatic pressing (HIP) only, HIP + T6 heat treatments, and T6 only, with different aging time, on surface properties, microstructure and mechanical properties of stress-relieved AlSi10Mg parts produced by direct laser metal sintering.

HIP process and HIP + T6 heat treatments were applied to as stress-relieved direct laser metal sintered (DMLS) AlSi10Mg parts. Aging times of 4 and 12 h are selected to examine the optimum duration. To analyze the advantages of HIP process, a T6 heat treatment with 4 h of aging was also applied. Densities, open porosities and roughness values of as stress-relieved, HIPed, HIP + T6, and T6-only samples were measured. The samples were characterized by OM and SEM together with EDX analysis. An image analysis study was made to evaluate the inner pore structure, thereby to understand the mechanical behavior.

HIP process does not cause a significant change in surface porosity; yet it has a positive influence on inner porosity. HIP process results in a microstructure of the aluminum matrix surrounded by a network of micron and nano size Si particles. Additional heat treatment results in larger particles and precipitation. After HIPing, ductility increases but strength decreases. Samples aged 4 h present improved yield and tensile strength but decreased elongation, yet samples aged for 12 h reach a combination of optimum strength and ductility. The lower level of tensile strength and ductility in T6-only condition indicates that HIP process plays a crucial role in elimination of the porosity thus improves the effectiveness of subsequent heat treatment.

The study investigates the effect of post-process conditions and optimizes the aging time of the T6 heat treatment after HIP process in order to obtain improved mechanical properties. The stress-relieved state was chosen as the reference to prevent distortion during HIPing or heat treatment.

With the emerging technologies, collecting and processing data about the behaviors of customers or employees in a specific location has become possible. The purpose of this paper is to evaluate existing data collection technologies.

Technology evaluation problem is handled as a multi-criteria decision-making (MCDM) problem. In this manner, a decision model containing four criteria and eight sub-criteria and four alternatives are formed. The problem is solved using hesitant analytic hierarchy process (AHP) and trapezoidal fuzzy numbers (TrFN).

The results show that the most important sub-criteria are: accuracy, quantity, ıntrospective and cost. Decision makers’ evaluate for alternatives, namely wireless fidelity (WiFi), camera, radio-frequency identification and Bluetooth. The best alternative is found as Bluetooth which is followed by WiFi and Camera.

Technology evaluation problem, just like many other MCDM problems are solved using expert evaluations. Thus, the generalizability of the findings is low.

In this paper, technology selection problem has been handled using hesitant AHP for the first time. In addition, the original methodology is extended by using TrFN to represent the expert evaluations in a better way.

This paper aims to investigate the structural, tribological and electrochemical properties of Ag₂O, ZnO, NiO coatings and Ag₂O/ZnO/NiO nanocomposite films deposited on commercially pure titanium.

Ceramic thin films (Ag₂O, ZnO, NiO coatings and Ag₂O/ZnO/NiO nanocomposite film) were deposited on commercially pure titanium (CP-Ti) substrate. Surface characterization of the uncoated and coated samples was made by structural surveys (scanning electron microscopic examinations and X-ray diffraction analyses), hardness measurements, tribological and corrosion experiments.

Results were indicated that sol-gel coatings improved the wear and corrosion resistance of CP-Ti, and the best results were seen at the nanocomposite coating. It may be attributed to its small grain size, high surface hardness and high film thickness.

This study can be a practical reference and offers insight into the influence of nanocomposite ceramic films on the increase of hardness, tribological and corrosion performance. Also, the paper displayed a promising approach to produce Ag₂O/ZnO/NiO nanocomposite coating on commercially pure titanium implants for biomedical applications.

This paper aims to investigate the effects of various heat treatments on microstructure, hardness, porosity and corrosion properties of the parts.

Hot isostatic pressing (HIP) process, various heat treatments and their combinations were applied to the AlSi10Mg parts produced by direct laser metal sintering (DMLS).

It has been found that the HIP process, which is a post-processing process, reduces the amount of porosity in DMLS-AlSi10Mg material, thus improves corrosion resistance significantly.

In this study, the HIP process and subsequent T6 heat treatments were applied to AlSi10Mg parts produced by the DMLS technique. The study aims to increase the corrosion resistance of AlSi10Mg parts by reducing porosity with the HIP process and by altering the microstructure with the T6 process.