Propulsion performances study for a chemical tank

The design of a propulsion system for each ship must take into consideration a large number of factors. Some important factors that will lead to obtaining an efficient propulsion system are: the integration of a large number of elements in a functional space, selection of suitable components, the efficiency assessment taking into account functional safety and comfort criteria for crew and passengers. Considering the factors listed above, the analysis and design of the propulsion system for a chemical tank was performed. To choose the optimal components, the propulsion performance for this ship was analysed using 4 different engines. The operation of the propeller behind the ship has an effect on both the structure of the ship and the navigation conditions of the crew on board. Ttherefore, in the last part of the paper will be presented the effect of the operation of the propeller chosen for the chemical tank. In this sense, the surface forces induced by the propeller that appear in the stern vault will also be a center of interest in this work.

Analisis Tingkat Preferensi Pemilihan Moda Transportasi Antar Kota Antar Provinsi dengan Metode AHP Topsis (Study Kasus Rute Cilacap - Yogyakarta)

There are different characteristics between the modes of land transportation, such as trains, buses and cars from Cilacap to Yogyakarta, the Inter-City Inter-Provincial route. This gave a question of what criteria a person chose in determining the mode of transportation preferences. A questionnaire was required for data collection, determining the number of respondents (users). There were 20 respondents; 55% have low income, 10% have middle income, 35% have a high income. Then the data from filling out the questionnaire was analyzed using the AHP-TOPSIS method to determine the weight of the research criteria that had the most influence on preferences for transportation modes. With the results of the weighted criteria: safety (47.80%), comfort (19.78%), travel time (12.47%), frequency (12.12%) and cost (7.83%). Furthermore, the results of the preferences for the choice of transportation modes showed that the first rank was achieved by cars (0.73), secondly by buses (0.66) and thirdly by trains (0.58). The sensitivity test results showed that increasing the weight of the comfort criteria would reduce the priority of the bus mode. As for the training mode, it could be increased by adding weight to the cost criteria.

Energy and seismic drawbacks of masonry: a unified retrofitting solution

All over the world, a large part of existing buildings is not adequate to satisfy the safety requirement and the thermal comfort criteria. For this reason, the interest in structural and energy retrofitting systems has steadily grown in the last decades. In this scenario, an innovative thermal resistant geopolymer mortar has been developed and used for Inorganic Matrix Composite (IMC) systems aimed to a combined seismic and energy new retrofitting technique. The geopolymer-based IMC is able to ensure competitive mechanical properties with respect to the traditional lime-based IMCs and, at the same time, a significant reduction in thermal conductivity. In this paper, an experimental program is reported considering small-scaled masonry panels with double-side IMC-retrofitting and determining both the in-plane shear strength and the thermal resistance. The experimental shear tests are aimed to compare the mechanical performance of the geopolymer innovative systems with those of the traditional lime-based ones. Moreover, the thermal resistance gain of the innovative solutions was measured and compared with traditional systems. The results evidenced the effectiveness of the proposed technique that significantly improved the performances of masonry walls from both the thermal and the mechanical point of view.

Study on Properties of Automatically Designed 3D-Printed Customized Prosthetic Sockets

This paper presents the results of experiments conducted on a batch of additively manufactured customized prosthetic sockets for upper limbs, made of thermoplastics and designed automatically on the basis of a 3D-scanned limb of a 3-year-old patient. The aim of this work was to compare sockets made of two different materials—rigid PLA and elastic TPE. Two distinct socket designs with various mounting systems were prepared. To find a reliable set of parameters for cheap and stable manufacturing of usable prostheses using 3D printers, realizing the fused deposition modeling (FDM) process, sets of sockets were manufactured with various process parameters. This paper presents the methodology of the design, the plan of the experiments and the obtained results in terms of process stability, fit and assessment by patient, as well as strength of the obtained sockets and their measured surface roughness. The results are promising, as most of the obtained products fulfil the strength criteria, although not all of them meet the fitting and use comfort criteria. As a result, recommendations of materials and process parameters were determined. These parameters were included in a prototype of the automated design and production system developed by the authors, and prostheses for several other patients were manufactured.

Some evidence of a time-varying thermal perception

Recent research suggests that a time-varying indoor thermal environment can lead to energy savings and contribute to boost buildings' energy flexibility. However, thermal comfort standardization has so far considered thermal comfort criteria as constant throughout the day. In general, very little attention has been given to the ‘ time of day' variable in the context of thermal comfort research. In this paper, we show some evidence of a time-varying thermal perception by using: (1) data from about 10,000 connected Canadian thermostats made available as part of the ‘ Donate Your Data' dataset and (2) about 22,000 samples of complete (objective + ‘ right-here-right-now' subjective) thermal comfort field data from the ASHRAE I and SCATs datasets. We observe that occupants prefer colder thermal conditions at 14:00 and progressively warmer ones in the rest of the day, indistinctively in the morning and evening. Neutral temperature differences between 08:00 and 14:00 and 14:00 and 20:00 are estimated to be of the order of 2°C. We hypothesize that the human circadian rhythm is the cause of this difference. Nevertheless, the results of this study are only based on observational data. Thermal comfort experiments in controlled environmental chambers are required to confirm these findings and to better elucidate the effects of light and circadian timing and their interaction on thermal perception.

Acquiring the Foremost Window Allocation Strategy to Achieve the Best Trade-Off Among Energy, Environmental, and Comfort Criteria in a Building

The purpose of this investigation is to propose a way for acquiring the foremost window allocation scheme to have the best trade-off among energy, environmental, and comfort criteria in a building. An advanced decision-making tool, named the technique for order preference by similarity to ideal solution (TOPSIS), is utilized to find the best building amongst different alternatives for having windows on the building façades. Three conditions, namely two parallel, two perpendicular, and three façades, considered as A, B, and C types, respectively, are investigated. For each type, four possible orientations are studied. Heating, cooling, and lighting energy demands in addition to carbon dioxide equivalent emission and thermal and visual comfort are taken into account as the investigated criteria, and they are all evaluated in a simulation environment. The results show that for the modular residential buildings chosen as the case study and located in Tehran, Iran, having windows on the north and east façades is the best scheme. This alternative, which belongs to the B type, has about 40% and 37% lower heating and cooling energy demands than the C type’s foremost alternative. It is also able to provide about 10% better CO2 equivalent emission and 28% higher thermal comfort.

Adaptation of Indoor Health and Comfort Criteria to Mitigate Covid-19 Transmission in the Workplace

The research discussed the application of indoor health and comfort criteria that needed to be reviewed to create good indoor environmental quality and reduce the transmission of the Covid-19 virus where people spent most of their time indoors. A confined area, which was poorly ventilated and reliant on air conditioning, helped transmit the Covid-19 virus easily as air recirculation was the main cause of office clusters. One of the categories of Greenship Interior Space, Indoor Health and Comfort (IHC), could be used as a guide for creating better indoor quality. The method used for the research was a systematic literature review to define, study, analyze, and classify all available research relating to adaptation of indoor health and comfort criteria to mitigate the transmission in the workplace. The results show the adjustment to IHC criteria in IHC 1-10, which focus on providing good air quality by introducing outside air, stopping air recirculation, reducing indoor user capacity, and reducing indoor biological and chemical pollutants. To illustrate the implementation of the new normal, Ciputra University workplace was being observed, as the findings of the results, some strategies that are in line with the objectives of IHC 1, IHC 2, and IHC 5. Adjustment of these criteria must be supported by implementing health protocols through basic hygiene routines, fitness screening, and maintaining physical distancing.

Environmental Awareness

University studies for the architecture degree in Spain give very little weight to considerations related to the design of a healthy interior environment. The low number of subjects related to interior comfort criteria may cause the student to underestimate the importance of environmental design of closed spaces in favor of aesthetic or merely functional aspects. However, there is a direct relationship between formal design decisions and environmental conditions in buildings, and future architects must understand those connections in order to make designs that combine efficiency and high aesthetic value. In this chapter, several pedagogical strategies are presented to get architecture students to learn and internalize the link between design and interior conditions, aiming at the acquisition of an adequate environmental awareness.

Determination of criteria for increased comfort in the design of a residential complex

The issue of determining the comfort of urban space, as well as in particular the territory of microdistricts, does not have an unambiguous interpretation in the normative or technical literature. There are various comfort criteria, most of them are considered from a mechanical point of view. As part of this work, the main criteria for determining the increased comfort of neighborhoods will be highlighted.