Housing Materials Research Articles

木造住宅における潜熱蓄熱建材の導入効果に関する研究（その3）：室内付属物を考慮した潜熱蓄熱建材の敷設方法の効果比較

The potential of using Phase Change Material (PCM) in wooden house has been investigated. Since the cost of the PCM is high, searching for a laying position with high heat absorption and dissipation efficiency has been shown as a problem to solve. At the same time, the internal screen also causes changes in the room surface temperature, which in turn affects the heat absorption effect of PCM. In this study, we focused on how the internal screen affects the thermal storage effect of PCM and discuss the means to improve the thermal storage effect.

Achromatic and Athermal Design of Aerial Catadioptric Optical Systems by Efficient Optimization of Materials.

The remote sensing imaging requirements of aerial cameras require their optical system to have wide temperature adaptability. Based on the optical passive athermal technology, the expression of thermal power offset of a single lens in the catadioptric optical system is first derived, and then a mathematical model for efficient optimization of materials is established; finally, the mechanical material combination (mirror and housing material) is optimized according to the comprehensive weight of offset with temperature change and the position change of the equivalent single lens, and achieve optimization of the lens material on an athermal map. In order to verify the effectiveness of the method, an example of a catadioptric aerial optical system with a focal length of 350 mm is designed. The results show that in the temperature range of -40 °C to 60 °C, the diffraction-limited MTF of the designed optical system is 0.59 (at 68 lp/mm), the MTF of each field of view is greater than 0.39, and the thermal defocus is less than 0.004 mm, which is within one time of the focal depth, indicating that the imaging quality of the optical system basically does not change with temperature, meeting the stringent application requirements of the aerial camera.

Lichens as material for Lepidoptera's housing: A molecular approach to a widespread and highly selective interaction

Interactions between lichens and invertebrates are widespread and have evolved independently in several orders of invertebrates. Lichens participate as food, shelter, background for mimicry, or as camouflage for animals to wear. For this study, we discovered caterpillars of the moth family Psychidae living inside bags made from silk and lichens. We used molecular techniques to identify the lichens present and analyzed caterpillar selectivity for lichen species. We selected 13 bags and recovered the ITS genetic marker for every visually different lichen fragment. Obtained sequences were compared against a newly created ITS database from lichens of the study area. Caterpillars only used eight out of the 300 lichen species present showing a strong selection tendency for microfoliose lichens containing sekikaic acid. Our results suggest that caterpillars select lichen species at a higher rate than what is expected based on their local abundances. We provide an accessible way to study these widespread interactions in future projects. • Lichen-invertebrate camouflage interactions show high levels of specificity. • Lichen-made Psychidae bags provide ecological advantages in tropical dry forest. • Psychidae caterpillars select microfoliose lichens with sekikaic acid. • Cost-effective new molecular approach allows studying these widespread interactions.

Water Phantom Characterization of a Novel Optical Fiber Sensor for LDR Brachytherapy

This work considers the feasibility of using a novel optical fiber-based sensor, employing a terbium-doped gadolinium oxysulfide (Gd2O2S:Tb) inorganic scintillator, as a real-time in vivo dosimetry solution for applications in low-dose-rate (LDR) prostate brachytherapy (BT). This study specifically considers the influence of scintillator geometry (hemisphere tip versus cylindrical cavity), polymethyl methacrylate (PMMA) fiber core diameter (0.5 versus 1.0 mm), and sensor housing material (stainless steel versus plastic) on the measured scintillation signal. Characterization measurements were performed using a silicon photon-multiplier (SiPM) detector and a commercial water phantom system, integrated with custom 3-D printed components to allow for precise positioning of the LDR BT radiation source with respect to the optical fiber sensor (OFS). Significant differences in the rate of fall-off in the scintillation signal, with distance from the source, were observed between the different scintillator geometries considered. The hemisphere tip geometry was shown to be the most accurate, tracking with the expected fall-off in dose-rate, within measurement uncertainty. Reducing the fiber core diameter from 1.0 to 0.5 mm resulted in a sixfold reduction in the detected scintillation signal. A further 57% reduction was observed when housing the 0.5-mm fiber within a stainless steel LDR BT needle applicator. Initial results demonstrate the feasibility of employing an OFS, for applications in LDR BT, given the excellent agreement of measurements with theoretical expectations. Furthermore, a calibration process has been described for converting the detected scintillation signal into absorbed dose/dose rate, using our water phantom-based experimental setup.

Implementation of Bayesian inference MCMC algorithm in phylogenetic analysis of Dipterocarpaceae family

Dipterocarpaceae is one of the most prominent plant families, with more than 500 members of species. This family mostly used timber plants for housing, making ships, decking, and primary materials for making furniture. In Indonesia, many Dipterocarpaceae species have morphological similarities and are challenging to recognize in the field. As a result, the classification process becomes difficult and even results are inconsistent when viewed only from the morphology. This research will analyze the phylogenetic tree of Dipterocarpaceae based on the chloroplast matK gene. The aim of the research is to classify the phylogenetics tree of Dipterocarpaceae family using Bayesian inference algorithm. This research used the chloroplast gene instead of morphological characters which has more accurate. The analysis steps are collecting data, modifying the structure sequence name, sequence alignment, constructing tree by using Markov Chain Monte Carlo (MCMC) from Bayesian Inference, and evaluating and analyzing the phylogenetic tree. The results showed that the tree constructed based on the gene is different from the tree based on morphology. Based on the morphological, Dipterocarpus should be in the Dipterocarpeae tribe but based on the similarity of its genes, Dipterocarpus is more similar to the Shoreae tribe.

Design and In Situ Validation of Low-Cost and Easy to Apply Anti-Biofouling Techniques for Oceanographic Continuous Monitoring with Optical Instruments.

Biofouling is the major factor that limits long-term monitoring studies with automated optical instruments. Protection of the sensing areas, surfaces, and structural housing of the sensors must be considered to deliver reliable data without the need for cleaning or maintenance. In this work, we present the design and field validation of different techniques for biofouling protection based on different housing materials, biocides, and transparent coatings. Six optical turbidity probes were built using polylactic acid (PLA), acrylonitrile butadiene styrene (ABS), PLA with copper filament, ABS coated with PDMS, ABS coated with epoxy and ABS assembled with a system for in situ chlorine production. The probes were deployed in the sea for 48 days and their anti-biofouling efficiency was evaluated using the results of the field experiment, visual inspections, and calibration signal loss after the tests. The PLA and ABS were used as samplers without fouling protection. The probe with chlorine production outperformed the other techniques, providing reliable data during the in situ experiment. The copper probe had lower performance but still retarded the biological growth. The techniques based on transparent coatings, epoxy, and PDMS did not prevent biofilm formation and suffered mostly from micro-biofouling.

Numerical Study on the Combined Use of Corten Steel and Phase Change Materials in Container-Type Houses

A study is presented on the feasibility of an approach based on the combination of Phase Change Materials (PCM) with metal walls in container-type houses. This line of research finds its motivations in recent trends in the energy and building sectors about energy consumption reduction. Another important objective concerns possible improvements in the comfort provided by such houses during the summer period. The results obtained through numerical solution of the governing equations accounting for heat transfer and latent heat effects associated with the PCM show that the indoor temperature can be reduced with a varying degree of success depending on the considered conditions.

Promoting burnt clay brick as an affordable housing material in developing economy: building professionals' perspective

Promoting burnt clay brick as an affordable housing material in developing economy: building professionals' perspective

Pendirian Rumah Baca untuk Meningkatkan Literasi Anak pada Masa New Normal di Satuan Pemukiman 1 Transmigrasi Kabupaten Ketapang Kalimantan Barat

In the new normal period, the face-to-face learning process in schools is not optimal because of the limitation of learning time by changing shifts to avoid crowds. This makes students not fully understand the material presented by the teacher. The purpose of this activity is to improve children's literacy in the new normal period in Settlement Unit 1 (SP 1) Transmigration in Sungai Besar Village, Matan Hilir Selatan District, Ketapang Regency through the establishment of reading houses as a place to assist children's learning after school. This community service activity is carried out by using the observation method and socializing the establishment of reading houses in partnership with PKH (Hope Family Program) companions and the Ketapang District Public Library as suppliers of books or reading materials in the established reading houses. Observation activities were carried out to determine the condition of the student learning process in the new normal period. The socialization activity was carried out to explain the establishment, management and programs that will be carried out in reading houses with the stages of mentoring the establishment of reading houses through PKH assistants on duty at SP1 Sungai Besar Village, introduction to peer tutoring, introduction to literacy culture for local communities. SP 1 Sungai Besar Village, and the recruitment of volunteers and people who care about literacy. The result of this activity is the establishment of a reading house by utilizing unused residents' houses. The manager of the reading house is a Ketapang State Polytechnic student who lives in SP 1 Sungai Besar Village and several students in the area.

Dinamika Arsitektur Rumah Adat di Kabupaten Sumba Tengah

Marapu is the Sumba people's ancestral faith that believes in the power of the ancestors. The indigenous community in Central Sumba strongly embraces the traditional ceremonies related to the marapu faith. On the other hand, modernity, loaded with capitalistic values, opens up the possibility for mobilities, one of which is ideological mobility. Globalization, followed by the entrance of modern religions, creates technological shifts in the traditional community's cultural system. This research investigates the dynamics of the traditionals houses architecture in Central Sumba Regency. This research also scrutinizes the ideology and other factors underlying the shifts. The theories of ideology and hegemony are eclectically applied. This research employs a qualitative research design. Data are collected through field surveys conducted in the traditional villages. Next, village members, relevant stakeholders are also interviewed. Besides that, a literature study is conducted, followed by a descriptive-qualitative analysis. The material and functional shifts of the traditional house happen due to the rise of new ideologies, hegemony imposed by the government, and economic factors. The shifts resulting from social and cultural changes are hopefully in line with the efforts to preserve the traditions and cultural remains of the traditional villages.

Analysis of the Performance of Natural Composite Materials Reinforced with Sago Sheath Fibers as an Alternative Material in Overcoming the Effect of Urban Heat Islands on Buildings

Local knowledge of a region is an asset that encourages the identification of a region. Hence, the specificity, uniqueness, and character that animates a particular city can distinguish it significantly from other cities. Sago tree fronds are widely applied to buildings as an alternative material for making tiles for roofs and other parts of buildings. The sago palm has long been used for making roofs and walls, especially in traditional houses. Few previous studies have used sago fronds as a manufacturing material for traditional houses. However, based on data in the field, many traditional houses still use sago fronds as a roof and wall framing material. This is also an effort to overcome the urban heat island phenomenon (UHI) in buildings. The UHI phenomenon is a phenomenon of urban development that highly affects environmental quality conditions and causes microclimate changes where air temperature conditions in urban areas are higher than the surrounding air temperatures. Sago midrib fiber is a natural composite material used as a reinforcing material for natural composite materials due to its thermal and mechanical properties. Composite materials using the hand lay-up technique—with characterization methods including the impact test and the DSC test, variations in NaOH levels, and variations in the resin–catalyst matrix—were used in this study. The results obtained were then compared with those in the literature. The results showed that 6% NaOH obtained the most significant impact value of 2.1 J, and the resin–catalyst matrix variation of 97.5%:2.5% obtained the most significant impact value, which was 2.4 J. Meanwhile, the DSC test results showed that the material’s best value for retaining heat was at 4% NaOH content variation and a resin–catalyst matrix variation of 97.5%:2.5%.

Review on comparative study of diverse wall materials for affordable housing

Modular Construction is a boon to the construction industry. Rapid construction methods are now evolving by the day. It is imperative to access these techniques on the basis of sustainability parameters. The advanced construction management concept such as fast track construction is being implemented in real estate industry with special focus on lean management. Ferro-cement panels, gypsum sheets, etc. are some of the precast members in construction which reduce the scheduled duration of the convectional project. It also significantly decreases the dead load of the structure. India’s focus on Sustainable Development goals has also conceptualized affordable housing as one of the methods to achieve it. The alternative for the conventional method of building houses is the use of ferrocement as it is cost effective. As the cost of constructing houses will reduce, the poor people living in slums area will afford to live in a hygienic place. This paper tries to analyze the two trending panel techniques namely: Gypsum & Ferro-cement on various technical aspects and the implication on affordable housing. Also, on conclusive note, the results of comparison are mentioned.

Housing conditions and long-term care needs of older adults in Ghana: Evidence from the WHO SAGE Ghana Wave 1.

The present study examined the association between housing conditions and long-term care needs of older adults in Ghana. We used data from 4,920 adults aged ≥50 years that participated in the World Health Organisation's (WHO) Study on adult health and AGEing Ghana Wave 1. Housing conditions were assessed with drinking water, sanitation, cooking conditions and building materials, and long-term care needs were based on WHO Disability Assessment Schedule 2.0. Multivariable logistic regressions modelled the effect of housing conditions on long-term care needs. After full adjustment for all available potential confounders, older adults living in households with unimproved cooking conditions had higher odds of reporting long-term care needs (OR = 6.87, 95%CI: 5.04-9.37) compared to those in improved cooking condition households. Moreover, those in households with unimproved housing materials (OR = 1.27, 95%CI: 1.01-1.72) and those in unimproved sanitation households (OR = 1.26, 95%CI: 1.05-1.54) were more likely to experience long-term care needs after respectively controlling for demographic and health-related covariates. Poor housing conditions are risk factors of long-term care needs in Ghana. Efforts to improve housing conditions may benefit older age functional abilities and unmet long-term care needs.

Technical Analysis of Soil Cement as A Construction Material Applied in Rural Houses

The project reveals the properties of soil cement as a construction material in rural houses. The context of this research was in Pilcomayo district, Huancayo, Peru, due to the high abundance of poor constructions without any security or comfort for the inhabitants of the area. In the experiment, the technical analysis of the soil cement was carried out with doses of 5%, 9%, 13%, 17% and 21% of cement, applying tests of Granulometry, Compaction, Compression and Durability established by the Portland Cement Association. It was found that the soil of the district has an efficient granulometry for the use of soil cement, and also that it has a resistance of 129.42 kg-f/cm² with 21% cement at 28 days of curing. The lab test results also showed that the cement soil loses just 4.22% in weight with 17% of cement in the durability test, as well as with this same percentage, the soil cement presents a higher maximum compaction density of 2,255 g/cm³. These results propose alternative applications for soil cement according to their resistance, granulometry and durability. According to the Peruvian Technical Standard, the minimum f'c for floor concrete base is 100 kg/cm², a dosage of 19% cement was proposed for this element, and for brick masonry the minimum f'c is 50kg/cm², so it was proposed 12% cement to meet this requirement, in addition, the soil cement was proposed as a slope protection with 17% cement since it achieved good results in the durability test.

Moisture Dependent Degradation Rate of Silicone in LED Optical Housing Material—Ab-Initio Modelling

Degradation of LED housings which make up of polydimethylsiloxanes (PDMS) in outdoor applications has been one of the rising concerns as they reduce the overall lifetime of the LED leading to cost and safety issues. The primary stressors for such LED degradation were found to be humidity and light emitted from the LED dice. The degradation mechanisms are hydrolysis and condensation of PDMS which themselves are interdependent. The degradation rate was also found to be dependent on the humidity level. This work identifies these dependencies, using ab-initio density functional theory and molecular dynamics simulation, and the results agree with the reported experimental data. From the detail understanding of the degradation mechanisms and the identification of the rate determining factors which are moisture level and the level of light absorption in PDMS, acceleration models commonly used for extrapolation are questioned, and new quality indexes of the PDMS are also identified to ensure the durability of LEDs in outdoor applications. Testing method to evaluate these new quality indexes is also proposed.

Study and comparison of estimated cost of a house in wassit governorate during 2002-2009

The main objective of present study is estimation of cost of a typical house located in Kut center ( Wassit governorate), suitable for a family of eight persons ( the average no. of persons per house hold in the govern orate is 8.13), with an average built up area 130 m2 0n a plot of 10m *20m(200 m2).The design of the dwelling unit consists of a ground floor only with a family room, kitchen, two toilets, two bedrooms, living room, one bathroom and staircase with penthouse. The structure of this dwelling unit consists of 25 cm thick load bearing. This study gives all the percentage of each item of materials and labor from the total cost and the cost of sq.m for year 2009 and the comparison with year 2002.The cost of the house (material and labor) per sq. m was estimated to be 375663 I.D, while thecost of (material) per sq.m was 233048 I.D, and the cost of (labor) per sq.m was 142615 I.D. and the total cost with the benefit of the contractor was estimated to be 53719910 I.D.This study declare that the cost of the house frame represent 57% of total cost and the finishing work represent 37% while the sanitary and electrical work represent 6% of the total cost. In comparison build cost between 2002 and 2009 it was found that the cost of same house increased about 379% due to increasing of construction materials and labor cost during this period. The prices of construction materials and labor in 2009 are more than 2002 as follow (brick 850%, cement 544%, labor 410%, sand 586%, and gravel 497 %.)

The presence of Plasmodium malariae and Plasmodium knowlesi in near malaria elimination setting in western Indonesia

BackgroundIndonesia is progressing towards malaria elimination. To achieve this goal, intervention measures must be addressed to cover all Plasmodium species. Comprehensive control measures and surveillance programmes must be intensified. This study aims to determine the prevalence of microscopic and submicroscopic malaria in Langkat district, North Sumatera Province, Indonesia.MethodsA cross-sectional survey was conducted in six villages in Langkat district, North Sumatera Province in June 2019. Data were recorded using a standardized questionnaire. Finger pricked blood samples were obtained for malaria examination using rapid diagnostic test, thick and thin blood smears, and polymerase chain reaction.ResultsA total of 342 individuals were included in the study. Of them, one (0.3%) had a microscopic Plasmodium malariae infection, no positive RDT examination, and three (0.9%) were positive for P. malariae (n = 1) and Plasmodium knowlesi (n = 2). The distribution of bed net ownership was owned by 40% of the study participants. The participants had a house within a radius of 100–500 m from the forest (86.3%) and had the housing material of cement floor (56.1%), a tin roof (82.2%), wooden wall (35.7%), bamboo wall (28.1%), and brick wall (21.6%).ConclusionMalaria incidence has substantially decreased in Langkat, North Sumatera, Indonesia. However, submicroscopic infection remains in the population and may contribute to further transmission. Surveillance should include the detection of microscopic undetected parasites, to enable the achievement of malaria elimination.

Electrical Conductivity Modeling and Fabrication of Carbon Nanotubes/Silicone Rubber Composites for High Voltage Insulators in Regions With a Polluted Atmosphere

The condensation mechanism of the insulators’ surface, increase the surface electrical conductivity. The electrical conductivity of the insulator creates a high level of leakage current and causes the failure. Difference between the dew point and the surface temperature of the insulator which occur due to radiative cooling mechanism, is the major reason of the moisture condensation on the polluted insulator surface. To compensate for the temperature difference, carbon nanotubes (CNTs) are being added to the silicone rubber housing material. The main idea of this research is based on generating joule heating by reducing the surface resistance of high voltage insulators. For this purpose, a developed model based on Halpin–Tsai formulation for tensile modulus of nanocomposites is joined with the conventional power-law model for the effective electrical conductivity of silicone rubber matrix carbon nanotube composite (SMCNT). SMCNT samples are prepared with the addition of various CNT volume fractions to high temperature vulcanizing (HTV) silicone rubber by melt-blending method. The developed model reveals that the high fraction of thinner and longer CNT, thicker interphase, higher concentration of percolated CNT, lower waviness of CNT, and higher conductivity of CNT can make a higher effective conductivity for SMCNT.

Investigation of glass sintering to improve strength and interfacial interactions in glass‐to‐AISI 316L metal joints

AbstractThe relationship between sintering and glass‐to‐metal bonding, which are almost the initial and the last stages of glass‐to‐metal seal production, has been demonstrated in this study. In this context, a type of barium alkali silicate glass was prepared, and thermal properties were determined by differential thermal analysis, dilatometer, hot‐stage microscope, and high‐temperature viscosity analysis. Detailed porosity investigations were examined with an optical microscope and ImageJ quantitative analyses, after binder removal and sintering processes carried out at different temperatures and times. An increase in porosity was observed when the sintering and binder removal temperatures and times were increased. The bending strength of the sintered glass sample was decreased with the increment in porosity. A typical housing material AISI 316L stainless steel was used for preparing glass‐to‐metal joints. The high porosity after sintering caused larger bubbles to form after bonding and reduced the shear strength. The effect of sintering conditions on the interfacial interaction for glass‐to‐metal joints are revealed by cross‐sectional scanning electron microscopy–energy‐dispersive spectrometer analyses. Atomic force microscopy analyses and contact angle measurements were conducted to supplement investigation. This study addressed that the mechanical strength and chemistry of glass‐to‐metal joints showed strong dependency on glass sintering conditions.

(Re)building first Nations community economies: From forest to frame

This paper uses the example of First Nations housing in British Columbia to explore how culturally legitimate community economies are being advanced to overcome the deficiencies of top-down, state-led housing efforts and market relations. Through the lens of the diverse economy, we highlight how First Nations community institutions can and do serve to oversee the utilization of territorial forest resources for the production and distribution of housing materials locally. The findings point towards First Nations communities navigating (often in latent ways) complex sites of decision-making through: ethical negotiations related to (de)commoditization; needs and surplus evaluation; and transactions and rules of (in) commensurability. While these examples appear to challenge the conventional logics of capitalist-market institutions, First Nations communities also must contend with the many structural barricades to change that exist within the settler-colonial institutional framework.